Medicine

ETHICAL PROBLEMS OF

ETHICAL PROBLEMS OF GENETIC ENGINEERING TECHNOLOGY.

MEDICAL USE OF STEM CELLS.

CLONING OF ORGANS AND TISSUES.

 

History of gene-transfer

Almost 20 years since the first gene-transfer trial was carried out in humans, the field has made significant advances towards clinical application. Nevertheless, it continues to face numerous unresolved ethical challenges — among them are the question of when to initiate human testing, the acceptability of germline modification and whether the technique should be applied to the enhancement of traits. Although such issues have precedents in other medical contexts, they take on a different character in gene transfer, in part because of the scientific uncertainty and the social context of innovation.

 

Описание: ecoli

Gene transfer research is a form of experimental treatment that involves transferring genetic  material into the cells of a patient with a disease caused by a missing or mutated gene. The goal is to cure the disease by modifying the genetic information of the patient‘s cells, thereby inducing normal protein expression to replace the mutated or lost gene.  For this to work, genetic material must be inserted into the target cells. One way to do this is to take advantage of the factthat some viruses can insert genetic material into host cells as part of their replication cycle; the virus inserts its genes into a host cell, induces the host cell to make more copies of the virus, then kills the host cell once the new viruses have been released from the host cell. A virus can be modified in the laboratory to delete the genes that the virus uses to make the host cell sick and those that kill the target cell after it has replicated the virus. In gene transfer research, those disease-causing virus genes are replaced with the ―good gene of interest which is missing or mutated in the patient. A viral vector, therefore, is a molecular biological tool in which the virus has been manipulated to allow insertion of the gene of interest into patient cells without the deleterious effects of viral infection.

Over the years, different expressions have been used to describe this procedure.  The term ― «gene therapy» began to be used in the late 1960s. Other expressions include: genetic surgery, genetic engineering, and gene transfer research (V. Walters 2000). The preferred term at this time is gene transfer research.

In studying the ethics of gene transfer research, a distinction should be made between research on the somatic (non-reproductive) cells and the germ (reproductive) cells of an individual. Only the germ cells carry genes that will be passed on to the next generation. Therefore, somatic gene transfer only affects the treated individual, while in germ cell transfer the modified gene is incorporated in the genome of the individual and can be transmitted to subsequent generations. 

On September 14, 1990 researchers at the U.S. National Institutes of Health performed the first (approved) gene transfer research procedure on four-year old Ashanti DeSilva. Born with a rare genetic disease called severe combined immune deficiency (SCID), she lacked a healthy immune system and was vulnerable to any passing germ. Children with this illness usually develop overwhelming infections and rarely survive to adulthood; a common childhood illness like chickenpox is life-threatening. DeSilva led a cloistered existence—avoiding contact with people outside her family, remaining in the sterile environment of her home, and battling frequent illnesses with massive amounts of antibiotics. 

In DeSilva's gene transfer procedure, doctors removed white blood cells from the child's body, let the cells grow in the lab, inserted the missing gene into the cells, and then infused the genetically modified blood cells back into the patient's bloodstream.  Laboratory tests showed that the treatment strengthened DeSilva 's immune system, and she was immunized against whooping cough. This procedure was not a cure; the white blood cells treated genetically only work for a few months, and the process has to be repeated (V. Thompson 1994).

While optimism was strong in the early days of gene transfer research, it has been increasingly acknowledged as both a scientifically and ethically challenging procedure. The biology of human gene transfer is very complex, and there are many techniques that still need to be developed and diseases that need to be understood more fully before gene transfer can be used appropriately.

The public policy debate surrounding the possible use of genetically engineered material in human subjects has been equally complex. Major participants in the debate have come from the fields of biology, government, law, medicine, philosophy, politics, and religion, each bringing different views to the discussion.

Some commentators on gene transfer research have objected to any form of genetic manipulation, no matter how well-intentioned (V. Rifkin 1983). Many others approve of the use of somatic cell gene transfer, but hesitate to allow the use of germ-line gene transfer that could have an unforeseeable effect on future generations. Still others have argued that with proper regulation and safeguards, germ-line gene transfer is a logical extension of the progress made to date, and an ethically acceptable procedure. Currently, germ-line gene transfer is considered by most to be ethically unacceptable and research has been prohibited around the world due to its unknown risks (II. David and Peebles 2008).  On the other hand, the consensus on somatic cell gene transfer is that it is ―…ethical to insert genetic material into a human being for the sole purpose of medically correcting a severe genetic defect in that patient (II. Anderson 1984).

Some argue that technology developed to treat disease in somatic gene transfer could be used to transfer genes for non-therapeutic reasons, namely to artificially enhance some members of society to become superior in one way or another, essentially causing a resurgence of the eugenics movement (VIII. Smith, et al. 2010).  Others argue that the possibility that this technology could be misused should not delay research and clinical application of therapy that could ameliorate human suffering (VI. Munson 1992).

Описание: gen transfer

Candidate Diseases for Gene Transfer Research

Gene transfer research is likely to have the greatest success with diseases that are caused by single gene defects. By the end of 1993, somatic cell gene transfer research had been approved for use on such diseases as severe combined immune deficiency, familial hypercholesterolemia, cystic fibrosis, and Gaucher's disease. Most protocols to date are aimed toward the treatment of cancer; a few are also targeted toward AIDS. Numerous disorders are discussed as candidates for gene transfer research: Parkinson's and Alzheimer's diseases, arthritis, and heart disease.

Eve Nichols describes the criteria for selection of disease candidates for human gene transfer research: 1) the disease is an incurable, life-threatening disease; 2) organ, tissue and cell types affected by the disease have been identified; 3) the normal counterpart of the defective gene has been isolated and cloned; 4) the normal gene can be introduced into a substantial subfraction of the cells from the affected tissue; or that introduction of the gene into the available target tissue, such as bone marrow, will somehow alter the disease process in the tissue affected by the disease; 5) the gene can be expressed adequately (it will direct the production of enough normal protein to make a difference); and 6) techniques are available to verify the safety of the procedure (V. Nichols 1988).

Cystic Fibrosis (CF) has long been thought to be an ideal genetic disorder for gene transfer research.  First, because the disease is caused by a loss of expression of a single gene product, cystic fibrosis transmembrane conductance regulator (CFTR), re-expression of this one gene should be feasible.  Second, CFTR is a membrane channel that functions to regulate the composition of lung secretions, and even though CF patients have various phenotypes in multiple organs, the main cause of death is due to chronic lung infections and inflammation.  The lung is a tissue that is easily accessible for gene transfer treatments delivered by aerosol inhalation or direct injection of liquid. The development of new vectors, technologies, and animal models will help the possibility of treatment of CF with gene transfer come to fruition.  New clinical trials are currently being planned to determine if CFTR gene transfer can improve CF lung disease (II. Sinn  2011).

The eye is another organ that has characteristics that make it an ideal candidate for gene transfer research.  The eye, especially the retina and vitreous of the eye, is easily accessible to treatment, and since it is transparent, it is easy to monitor efficacy of treatment.  Its unique structure of interconnected well-organized cells aids in delivering therapy to the appropriate cell types.  In addition, the blood-retina border prevents unintentional side effects and immunological responses that could compromise the therapy, because movement of therapy to other organs is limited.  Leber congenital amaurosis (LCA) is a disorder that causes the progressive degeneration of the retina, eventually leading to loss of vision.  LCA is caused by mutations in many genes, one of which is the retinoid isomerase enzyme, RPE65, which is essential for production of a pigment in the rods and cones of photoreceptors in the retina.  Gene replacement or augmentation therapy for LCA would be expected: 1) in young patients with little impairment, to improve vision by restoring photoreceptor function lost when RPE65 was mutated, or 2) in older patients with advanced disease, to prevent further photoreceptor loss.  In 2007, three different gene transfer research clinical trials treated three patients each, and have shown some early success in gaining and preserving visual function in patients with LCA by replacing RPE65.  These trials were able to support the safety of subretinal gene transfer, since no serious adverse effects, toxicity, or immune responses were detected.  They were also able to show an improvement in visual function and retinal sensitivity, namely a gain in perception of stationary targets, within a few weeks after the gene transfer.  Long term improvement was shown to persist for over two years, indicating that the gene was produced at physiologically relevant levels and was stable.  Further studies started in 2009 included patients as young as 8 years of age. Again, the treatment‘s safety and efficacy was supported even over a 2.5 year interval.  Children showed the greatest improvement, being able to move about independently and participate in normal classroom and athletic activities (II. Cideciyan 2011; II. Den Hollander 2010; II. Smith 2009).

Brief History of Gene Transfer Research and Its Regulation in the United States John Fletcher cites 1967 as the threshold of the gene transfer research debate, when Nobel Prize winner Marshall Nirenberg wrote of programming cells with synthetic messages, and recognized the promise and danger of this scientific procedure (VI. Fletcher 1990). 

A seminal event in the history of gene transfer research occurred when an American doctor, Stanfield Rogers, collaborated with a German physician to treat two sisters suffering from an inborn error of metabolism, hyperargininemia, with Shope papilloma virus (SPV) between 1970 and 1973 (III. Terheggen 1975).  It was erroneously believed that the virus would cause expression of the gene defective in the children. The gene normally regulates the production of arginine and it was thought that treatment could alleviate some of the symptoms of the disorder such as slowed mental and physical processes and spasticity of the muscles. 

In 1974 the National Institutes of Health (NIH) took the lead in regulating research with recombinant DNA (rDNA)—one of the building blocks of gene transfer research. According to the NIH Guidelines, recombinant DNA molecules are defined as molecules constructed outside living cells by joining natural or synthetic DNA segments to DNA molecules that can replicate in a living cell (VII. NIH 2011).The Recombinant DNA Advisory Committee (RAC) to the NIH Director was originally created in response to concerns of the general public about the safety and ethics of rDNA research.  The RAC was at first responsible for approving all research projects involving recombinant DNA in laboratories in the United States, and then handled gene marking research.  Gene marking allows researchers to mark a gene in some way as to be able to follow that gene once introduced into target cells.  Gene marking is different from gene transfer research because there is no intended benefit to the host of inserting this marked gene – it issimply a way to follow what the gene does and where it goes once inserted, for the sole purpose of information gathering in a research setting.  This is different from the goal of gene transfer research, which is to give some clinical benefit to the host cell into which the gene is inserted.

As of 2011, the RAC reviews rDNA issues and recommends a course of action or policy to the NIH Director.  These recommendations are disseminated through the NIH Office of Biotechnology Activities (OBA), which is responsible for oversight of rDNA research at NIH.  

In addition, the RAC reviews all gene transfer protocols in conjunction with the Food and Drug Administration (FDA). The FDA focuses on the safety and efficacy of genetically altered products, on the safety of the manufacturing process, and on control of the final product. Current information about the RAC can be found on NIH's Office of Biotechnology Activities' Web site.

The document "Points to Consider" continues to be updated, and can be found as Appendix M of NIH's Guidelines for Research Involving Recombinant DNA Molecules. RAC scrutiny of gene transfer clinical trials does not duplicate FDA oversight or IRB review, but rather focuses on the scientific integrity of the research (VII. Ertl 2009). RAC meetings are open to the public, and video recordings of the meetings can be downloaded from the RAC website. 

Oversight by the RAC and the FDA requires preliminary approval by the home institution's institutional biosafety committee (IBC) and institutional review board (IRB); final approval is then required by the RAC. These regulations apply to all federally funded institutions performing rDNA research, regardless of the funding for the specific project, and regardless of whether or not the research took place in the United States.

The first attempt at human gene transfer research was performed under questionable circumstances by University of California at Los Angeles (UCLA) researcher, Dr. Martin Cline.

Without the approval of his UCLA IRB, Cline performed a recombinant DNA transfer into cells of the bone marrow of two patients with hereditary blood disorders in Italy and Israel. At the time, Italy did not have IRBs, and Dr. Cline did not disclose fully to the Israeli IRB the exact nature of the gene transfers he proposed. In October 1980, the Los Angeles Times published details of Dr. Cline's activities (III. Jacobs 1980). Subsequently, he was forced to resign his department chairmanship at UCLA, he lost grant funding, and for a period of three years, all of his applications for grant support were accompanied by a report of the investigations into his activities in 1979-1980. 

In light of Dr. Cline's experiment, and at the prompting of the National Council of Churches, the Synagogue Council of America, and the United States Catholic Conference, the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research became involved with the issue of gene transfer research and released a landmark study called Splicing Life in 1982 (IV. United States President‘s Commission 1982). The President's Commission vigorously defended the continuation of gene transfer research. Splicing Life responded to the concern that scientists were playing God, concluding that we can distinguish between acceptable and unacceptable consequences of gene transfer research. The Commission suggested that the RAC broaden the scope of its review to include the ethical and social implications of gene transfer research.

In 1984 the RAC created a new group, called the Human Gene Therapy Working Group (later called the Human Gene Therapy Subcommittee (HGTS)), specifically to review gene therapy protocols (VI. Walters 1991). The first task of the Working Group was to produce the "Points to Consider for Protocols for the Transfer of Recombinant DNA into the Genome of Human Subjects" document as a guide for those applying for RAC approval of gene transfer protocols (VII. United States National Institutes of Health 1990).

Another outcome of the hearing was the 1984 U.S. Office of Technology Assessment (OTA) background paper Human Gene Therapy, which stressed the difference between somatic and germ-line gene therapy (VII. United States Congress Office of Technology Assessment 1984). OTA also issued an important survey on public opinion regarding genetic technologies, New Developments in Biotechnology, Volume 2: Background Paper: Public Perceptions of Biotechnology (IX. United States Congress. Office of Technology Assessment 1987).

Other attempts by Congress to participate in the public debate on gene transfer research were less effective. Emanating from the hearings chaired by then Congressman Al Gore, was legislation to create a federal commission to study the ethical, legal and social issues of genetic engineering (VII. United States Congress 1982), but the bill never passed. The Biomedical Ethics Advisory

Committee briefly studied the issue of gene transfer research, but its mandates to study issues relating to death and fetal tissue research led it to become embroiled in abortion politics, and the Committee collapsed before taking action (VII. Cook-Deegan 1990).

By late 1985 the RAC Subcommittee had its "Points to Consider" document ready and waited for gene transfer protocols to be presented. The first protocol it received, in 1988, was actually for gene marking. Steven Rosenberg proposed using gene marking techniques to track the movements of tumor-infiltrating blood cells in cancer patients; no actual therapy was proposed.

After several months of discussion among the HGTS members, and the gathering of additional information, the protocol was approved by a mail ballot in December 1988. The experiment was briefly stalled by a lawsuit filed by the Foundation on Economic Trends questioning the validity of the review process (VII. Foundation on Economic Trends 1991).  Eventually Rosenberg and colleagues did perform the experiment, and found that they were successfully able to follow the distribution and survival of the tumor-infiltrating lymphocytes that had been induced to express a gene for antibiotic resistance by retroviral gene transduction (III. Rosenberg 1990).

In 1990 the HGTS received two protocols to review. One was from Michael Blaese and French Anderson for gene transfer research on children like Ashanti DeSilva who suffered from SCID; the other was from Steven Rosenberg and colleagues who wanted to use the same tumorinfiltrating blood cells, now genetically altered, to deliver a tumor necrosis factor designed to kill tumor cells. Both protocols were approved. The SCID clinical trial found that after two years of gene transfer of the adenosine deaminase (ADA) gene in two SCID children, certain aspects of the immune system remained normalized even four years after the initial treatment. The conclusion was that gene transfer was safe and effective (III. Blaese 1995). In initial studies by Rosenberg and colleagues using the tumor-infiltrating cells secreting tumor necrosis factor, five patients were treated.  When the injection site was incised three weeks after gene transfer, no viable tumor could be found (III. Rosenberg 1993).

In December 1992 Dr. Bernadine Healy, then Director of the NIH, approved a compassionate use exemption from the regular review process to allow a critically ill patient to receive gene transfer. This circumvention of the regular approval process proved very controversial and set off a series of meetings aimed at creating procedures for dealing with expedited review of single patient protocols in the future (VII. United States National Institutes of Health 1993).

In October 1999, the death of Jesse Gelsinger, the first fatality in a gene transfer experiment, was reported in Nature (III. Lehrman 1999). Gelsinger carried the diagnosis of partial deficiency of ornithine  transcarbamylase (OTC), an enzyme in the pathway to break down ammonia. Patients with a total lack of this enzyme die shortly after birth due to the build-up of ammonia, whereas patients like Gelsinger can be treated with drugs and diet. He was in a Phase I trial of escalatingdoses of adenoviral vectors with the OTC gene when he died. He was the first patient whose death could be directly attributed to administration of the adenoviral vector.  Subsequent investigations revealed that deaths in animal trials did not receive the usual public disclosure (III. Nelson November 3, 1999). Gelsinger's death also raised questions about researcher entrepreneurial activities and conflict-of-interest, and about government oversight procedures (III. Nelson November 21, 1999). The United States Senate held hearings on this topic on February 2, 2000 (VII. United States Congress 2000), and the heightened scrutiny has resulted in increased reporting of adverse effects and renewed oversight by both NIH and FDA (VII. Smith and Byers 2002). Gelsinger's death also resulted in federal charges being brought against the clinical trial researchers and their institutions, who reached a settlement with the U.S. Office of the Attorney General in February, 2005(VII. United States. Department of Justice. Office of the Attorney General 2005)

The success of a multi-center trial for treating children with SCID held from 2000 and 2002 was questioned when two of the ten children treated at the trial's Paris center developed a leukemia like condition. Clinical trials were halted temporarily, but resumed after regulatory review of the protocol in the United States, the United Kingdom, France, Italy, and Germany (VII. CavazzanaCalvo 2004).

In 2007, a death in a gene transfer trial for arthritis was found to be from factors not related to the trial. This case prompted discussion of including procedures for investigating illness occurring during a study in the trial‘s protocol (III. Zaia and Federoff 2009).

Описание: gen-trans

Arguments in Favor of and Against Gene Transfer Research

The central argument in favor of gene transfer research is the hope that it can be used to treat desperately ill patients, or to prevent the onset of horrible illnesses. Conventional treatment for the candidate diseases for gene transfer research is limited; for patients with those diseases, gene transfer may offer the only hope. Many commentators liken somatic cell gene transfer research to other new medical technologies, and argue that we have an obligation to treat patients if we can Eric Juengst summarized the arguments for and against human germ-line gene transfer in 1991:

1) germ-line gene transfer offers a true cure, and not simply palliative or symptomatic treatment;

2) germ-line gene transfer may be the only effective way of addressing some genetic diseases;

3) by preventing the transmission of disease genes, the expense and risk of somatic cell transfer for multiple generations is avoided;

4) medicine should respond to the reproductive health needs of prospective parents at risk for transmitting serious genetic diseases;

5) the scientific community has a right to free inquiry, within the bounds of acceptable human research.

Arguments specifically against the development of germ-line gene transfer techniques include:

1) germ-line gene transfer research would involve too much scientific uncertainty and clinical risks, and the long term effects of such research are unknown;

2) such gene transfer research would open the door to attempts at altering human traits not associated with disease, which could exacerbate problems of social discrimination;

3) as germ-line gene transfer involves research on early embryos and effects their offspring, such research essentially creates generations of unconsenting research subjects; 4) gene transfer is very expensive, and would never be costeffective enough to merit high social priority; and 5) germ-line gene transfer would violate the rights of subsequent generations to inherit a genetic endowment that has not been intentionally modified (VI. Juengst 1991).

Many people who voice concerns about somatic cell gene transfer use a "slippery slope" argument against it. They wonder whether it is possible to distinguish between "good" and "bad" uses of the gene modification techniques, and whether the potential for harmful abuse of the technology should keep us from developing more techniques (V. Hubbard and Wald 1993).

Other commentators have pointed to the difficulty of following up with patients in long-term clinical research (III. Ledley 1993). Some are troubled that many gene transfer candidates are children too young to understand the ramifications of gene transfer research.

Others have pointed to potential conflict of interest problems—pitting an individual's reproductive liberties and privacy interests, on the one hand, against the interests of insurance companies, or society on the other—not to bear the financial burden of caring for a child with serious genetic defect. Issues of justice and resource allocation have also been raised: in a time of strain on our health care system, can we afford such expensive research? Who should receive gene transfer? If it is made available only to those who can afford it, concerns have been raised that "…the distribution of desirable biological traits among different socioeconomic and ethnic groups would become badly skewed (VI. Juengst et al. 1991).

The ethical issues posed by both somatic and germ-line gene transfer research are international in scope. The documents listed below serve to demonstrate the variety of reactions to gene transfer research, and to illuminate the complexity of this continuing public debate.

Описание: images

Anderson argues for three requirements for the clinical trial of somatic gene transfer in humans. These are based on animal experiments. Animal studies must show that:

1) the gene can be put into the target cells and be effective

2) the gene can be expressed at an appropriate level

3) the gene will not harm the cell or the animal.

Anderson also discusses germline cell transfer research, enhancement and eugenics. These diseases include Lesch-Nyhan Disease andSevere Combined Immunodeficiency Disease, which are diseases caused by defective or missing enzymes or proteins that do not need to be exactly regulated.  Anderson states that ―all observers‖ believe that it is ethical to insert genetic material into a human being in order only to correct a severe genetic defect.

Zaia and Federoff discuss the concept of therapeutic misconception' for the researcher as well as for the trial subject. They recommend that the «protocol should clearly state how to proceed in the event of any unforeseen illness.»

Описание: gene_synth

 

HUMAN GENOME PROJECT

Progress in molecular biology has enabled us to better understand human genetic disease, and has helped enhance the quality of life. This has been possible with technical developments to detect genetic disease presymptomatically. Presymptomatic testing would not yield information about the carrier status of an individual but also about other family members. Such information may lead to unreasonable beliefs and could alter social relationships. Ability to gain genetic information of the fetus has reduced the burden of suffering on human beings. Since fetal abortion is a sensitive issue, approach to such an information should be evaluated critically; and cautiously. Increase in genetic knowledge and capacity to manipulate life-form for convenience has raised several ethical questions and has challenged our moralistic and traditional responses. In India, little emphasis has been laid on ethical issues regarding genetic testing of disease. With adoption of new technology, it is high time that necessary steps are taken in this direction.

Introduction

Bioethics is a broad term and a very broad field of study. Bioethics can be defined as that discipline dealing with ethical issues raised by new developments in medicine and biological science. In the past (about 50 years ago), bioethics was used to solve simple ethical problems using Hippocrates postulates and Christian humanism. With advances in technology and cultural revolution, the traditional approaches of bioethics fail to account for certain complex events.

Bioethics, as a separate formal field of study is roughly around 25 years old and one origin is the 1962 publication of Life magazine. Modern approaches to bioethics are derived from disciplines like philosophy, theology, medicine and law. The four cardinal principles that underline bioethics are confidentiality, beneficence, justice and autonomy. Medicine and other benefits of science have reached many social, cultural and religiously-diverse groups and acceptance of these benefits have triggered wide variety of responses, and has generated good public interest

In such a scenario, bioethics accounts for changes in both understanding and meaning. Application of bioethics involves three players: Physicians to practice beneficence, society to defend justice and patients to be granted autonomy. Many professionals need to be involved to accomplish these goals. A universal bioethical law is the need of the day. We wish to discuss three issues involving bioethics: presymptomatic genetic testing, prenatal diagnosis, and genetic manipulation.

Pre-Symptomatic Genetic Testing

Genetic testing for hereditary susceptibility to disease is new and the possibility of early diagnosis has changed the advent of genetic testing. Presymptomatic molecular diagnosis is important in identifying carriers in populations, which could enable us to stop manifestation of

HUMAN GENOME PROJECT 77

disease prior to its occurrence. Molecular diagnostic tests are available for several diseases, such as Huntington’s disease, cystic fibrosis and sickle-cell anemia. This has been dubbed as genetic prophecy. The information gained by molecular testing could be also misused. Ethical difficulties due to molecular presymptomatic testing arise at three different levels, in society, in employment and in insurance.

1.     Social Issues

Genetic testing may lead to discrimination and stigmatization. In India, religions have strong hold over us and diseases are considered as punishment to evil deeds committed in the past or previous birth. Marriage is an important institution in our society. Mates are drawn from endogamous populations belonging to the same caste and religion. Individuals affected or carriers would be looked upon by our social system.

At an individual level acceptance to predisposition to a disease is a slow and painful process. The psychodynamics involved are rather complex. Another important aspect is the issue whether children should be aware of a disease they are going to suffer from, and particularly one which has no cure. Example of cystic fibrosis would throw more light on this issue. The simplest CF tests can pick 75% of the carriers. The accuracy of the diagnostic test is important.

One-fourth of the carrier couples would be missed by this test. This leaves 56% of the carrier couples at risk. If both partners would be identified as negative by this test. Genetic screening opens new avenues for carriers and many of these may not be generally accepted by individuals or couples. These include: remain childless, by remaining single or voluntarily foregoing the opportunity to have children; Selection of a partner, who is not a carrier; To use assisted reproduction techniques in order to avoid having affected children. Each of the above options have raised controversies and are topics under intense consideration in the West. Acceptance of these would involve personal sensitivities.

Molecular testing can reveal information about relatives of an affected individual, who otherwise may not wish to know about their genetic status of the disease because this may lead to excommunication and discrimination of healthy individuals.

2. Employment

Denial of employment on the basis of information gained by genetic testing, is cause of serious ethical concern. The example of an American firm, which screened black employees for the presence of sickle-cell anemia is very apt here. Interest of an employer lies in investing into the expansion of business rather than on equipment for the safety of a specific employee. The better option for the employer is sacking the employee, citing reasons other than genuine.

Re-employment might not be possible with a new employer for the same reasons.

3. Insurance

Insurance companies have started to think in a direction where a person predisposed to a particular disease may not be able to have insurance cover. The insurer could go for a test without the knowledge of the customer and basing on the results of the test insurance policy could be sold or withdrawn.

Prenatal Diagnostics

Prenatal diagnosis is the identification of disease of the fetus. The three main purposes of prenatal diagnosis are: to inform and prepare parents for the birth of an affected infant if any;

to allow in utero treatment for postnatal treatment, if required; to indicate termination of an affected fetus. As of today, termination of affected fetus dominates over its management,

Technology today is capable of detecting a disease/disorders of the fetus to which it is, going to be susceptible in the future, from the mother’s blood stream. We can well list out many diseases the unborn child is likely to be born with. Information gained from a battery of tests may affect the child in admission to school and college, employment and social standing. Steps to be taken towards proper use of prenatal diagnosis must be taken after careful and deliberate consideration. The fetus and abortion are sensitive issues. Ethical discussion on these topics is exhaustive. Much scholarship has been devoted here and in the west. It has become a major political argument.

(a) Human hazard: How safe are those involved in manipulating genomes? The evaluation or risk involved in working with vectors, proper disposal of laboratory by-products and critical evaluation of the manipulated organism is needed.

(b) Ecological hazard: Modified organisms can be sources of instability in an ecosystem.

The disturbance may be observed after certain damage or it may go unnoticed. For example, recombinant DNA technology has enabled the production of insulin from E.coli strains. These organisms have been grown in large quantities and from them insulin harvested. Insulin is carefully regulated in the human body, and this equilibrium could be upset in an event, such as if insulin-producing bacteria could gain entry into human intestines, this would well mean a man-made problem. The second aspect is ecological hazards of monitored organism, which can be sources of instability in an ecosystem at various levels. Some effects may be beyond human observation. Involvement of intelligentsia is not only required, but the participation of the common man is very much necessary. A consensus should be reached based on ethical questions like, How far are we to proceed and develop genetic engineering? Do we want to assume basic responsibility for life on this planet? Should we take the evolution into our hands, which otherwise is a slow process in natural time scale?

Gene therapy is an effective way to correct gene deficiencies by replacing defective gene or supplementing it. Gene therapy is distinct and differs from other medical therapies, because it brings about changes in make up of an individual. Biblical saying goes ‘God made man in his own image’. How far is man justified ‘playing God’, tampering with human genes. Gene therapy seems to be less mired with ethical problems than gene diagnosis. It was first performed in 1990 on adenosine deaminase (ADA) gene in the USA. In India, so far a gene therapy trial has not been reported. There are many unresolved issues to currently available gene therapies such as safety and stability of the vectors, behaviour of the gene after transfection, etc.

Basic considerations concerning gene therapy in India would be (a) to study the validity of the available protocols from abroad and evaluate as to how well they suit Indian conditions.

 (b) Indigenous development of techniques so as to reach the benefit to millions.

Conclusion

These issues of bioethics seem to have little relevance in India. Being a developing country, unemployment, hunger and poverty hold priority. However, bioethical issues should not be ignored. Genetic diseases in India have not drawn much attention and the geneticist is confined to the four walls of the laboratory, unaware of the prevailing situations. On one end of the spectrum it is the liberal, affluent and the educated class whereas on the other illiterate and poor. Of course, there is a sizable middle class too. Taking decisions can affect each of these  groups in different ways. Risk and benefits have to be weighed keeping in view all these groups.

The study of responses to topics, like prenatal diagnosis and genetics testing, can gather up to provide us with much information.

Описание: ethical human genom

ETHICAL ISSUES OF THE HUMAN GENOME PROJECT

Introduction

Science is a human endeavour, so it is never perfect. Human beings today, perhaps as never before in history, find themselves perplexed in an enigmatic environment created as a result of human intelligence and activity. It took more than a decade since the start of the dedicated Human Genome Project, but the announcement of the draft full DNA sequence on 26 June, 2000 will be a historical day. Some people said, it will be remembered as the day when we learnt “what it means to be a human”.

The initial proposal for the “Human Genome Project” is considered to be the 1986 editorial by Renato Dulbecco, in which he suggested that the fundamental problems related to cancer can be addressed by determining the sequence of the entire genome. Since then efforts have been continued at a global level to study the entire genome of human and a number of other model organisms. Already the complete genome of over 20 organisms was sequenced before scientists achieved the full draft human sequence. The molecular dissection of the genomes from so many species has unquestionably changed the scope for scientific and medical research.

However, as humankind applauds itself on the arrival of the “working draft” of the human genome, it is also a time to go back and explore what “human” means beyond times and scientific research. We need to reexamine how far human beings have come in an attempt to find our niche in nature and the ethical challenges that lie ahead in our attempt to redefine the meaning of life. From the very beginning, the Genome Project has been in the limelight for various reasons including the potential benefits and risks of this pioneer effort that will effect all parameters of life on this planet.

In this paper, I can only introduce some of the ethical issues, under the headings below:

1.     Medical Prospects

The central thrust to the Human Genome Project was undoubtedly for biomedical research.

The sequencing of the entire genome has already had a profound impact on the wider spectrum of clinical research, as it opens a new horizons for not only treatment of diseases but looking at the most fundamental causes of diseases. Already the genes for many diseases including for example, various cancers, Alzheimer’s disease, and polycystic kidney disease, have been identified.

Genomic sequencing allows rapid and accurate diagnosis for individuals. Initially the sequencing of human genome has led to a shift towards preventive medicine rather than curative, because further research is needed to develop therapies.

Earlier detection of genetic predispositions to disease can be used for late onset of genetically-inherited diseases. Such discoveries will enable us to work out which combinations of genes and environmental factors will lead to disease. In addition gene therapy is being tested.

Other advantages of the sequencing include genetic testing and screening, and its use in reproductive technologies for preimplantation diagnosis.

Knowing the genes helps in understanding the molecular basis of medicine, so that we can make rational drug design, so that drugs can be designed to target the cause of the disease. The drugs can be designed for specific individuals, pharmacogenics, “custom drugs”, which will change the prescription of drugs.

Also in the risk assessment of health damage and risks caused by radiation exposure, including low-dose exposure, and assessment of health damage and risks caused by exposure to mutagenic chemicals and cancer causing toxins, to reduce the likelihood of heritable mutations.

2. Scientific Prospects

One of the ideals of science is freedom for self-understanding. The influence of Human Genome Project on human self-understanding has been heralded as revolutionary. The sequencing of the genome will provide new clues on how we evolved. It would help us to understand what it means to be a human from different historical perspectives of bioarchealogy, anthropology, evolution, and human migration. Broader questions on the evolution of Homo Sapiens, the extent of human diversity, how much we share with nature or what makes us different from others will be answered by comparisons of genomes.

3. Agricultural Prospects

The parallel study of the genome of other organisms including those of plant and animal origin is progressing breeding in plant agriculture and livestock breeding. The rice genome has been completed. The sequencing of potato genome is underway. Pathogens have also been sequenced.

Genetically-Modified Organisms (GMOs) are already a hot topic in agriculture and livestock breeding. GMOs are organisms with genes modified for one or the other trait. We now have plants that are insect resistant, disease resistant, drought and cold resistant. We have farm animals that are healthier, more productive and disease resistant. Other plants and animals that are genetically modified include ones that incorporate vaccines in an edible form, or deliver hormones.

Genetic modification is also hotly debated. The eulogists, or proscience people, argue that the increase in the crop productivity with genetically-modified plants can be considered an option to the question of food security, given the number of hungry and chronically malnourished people in the world. The statistics show that we have over 800 million people who face starvation and malnourishment. It is our ethical duty to alleviate hunger and ensure access to food for all, given the number of lives lost and the loss in the quality of life. The technology behind genetic engineering is appealing and provides vision for many possibilities.

The people against it are sometimes called as anti-science people. There are many arguments against genetic modification, including “playing God”, safety, environment impact, potential loss of biodiversity, cost-effectiveness, access to the technology.

4. Environmental Applications

Taking into account the potential advantages of the Human Genome Project, similar public and private-funded projects were started to sequence the genomes of various microbes. Besides their role in disease, a further reason is that microbes play a critical role in biogeochemical cycles and they have been found surviving and thriving in amazing diversity of habitats often where no other life forms could exist. Annotation and analysis of microbial genomes will help in identifying and harnessing their capabilities to address the environmental problems, their use in energy production that can be used as biofuels, as an answer to the limited natural resources available. The challenges of environmental remediation, toxic waste reduction, environmental monitoring to detect the pollutants have been debated.

Despite our reliance on the inhabitants of the microbial world, we know very little about their nature and characteristics. Estimates show that microbes make up 60% of the Earth’s biomass and yet less than 1% of the microbial species have been identified. We cannot be reminiscent, nevertheless we have seen spectacular technologies like nuclear power creating a havoc in the past. There always lies the “fear of unknown”, and especially with so much of the microbial diversity uncharted there is a need for a cautious and critical approach.

5. Use in Forensic Science

Forensic science is one of the fields that is also expected to be benefited from the genome sequencing, especially in the identification of criminals and victims of some tragedy. The genome project is expected to provide clues to examine the context and the environment in which the science and the law meet. The other examples of DNA uses for forensic identification include, identifying endangered and protected species, help in establishing relationships with family members. Though genome sequencing envisages a broader scope for forensic science, there are some sceptics about its effectiveness when used.

6. Economic Implications

The Human Genome Project is the largest single biological project ever undertaken. For example, just the government budget in the United States started with US $28 million in 1988, and was at US $361 million in 2000, approximately a twelve-fold increase in the funding. Other governments also spent much, and private investment at least was equal to this. Such a huge monetary investment in itself testifies to the foreseen benefits out of the sequencing. Nevertheless the cost-effectiveness of the project was under criticism especially in early years. The critiques are apprehensive about existing gaps in the genome.

The questions of patenting of DNA, and genes by governments and private companies, intellectual property rights and benefit-sharing, have been particularly debated, and can be seen in the public announcements of first draft human genome sequence in year 2000.

The above questions though very significant, represent only one aspect of the economic implications. Another impact of the Human Genome Project is for developing countries who may have different priorities for investment in science. Also, multinational companies especially pharmaceutical companies will seek markets for designer drugs at low cost. This could be regarded as a conflict of interest between the needs of the common people to the interest of the governments and the private sector, especially for the people of the developing countries.

7. Ethical Concerns

Since the beginning of the Human Genome Project, many ethical questions were raised.

Recognising that, the U.S. Department of Energy (DOE) and the National Institutes of Health (NIH) allocated 3–5% of their total expenditure on HGP for the Ethical, Legal, Social Implications (ELSI) arising out of the Genome Project. This represented the world’s largest bioethics program. The European Commission only started funding the HGP when it had set up an ELSI program. Since then there have been contemporary efforts going on to answer some of the bioethical challenges of the Human Genome Project.

Bioethics can be called as love of life. It is the concept. Bioethics could be viewed in descriptive, prescriptive and interactive ways. Interactive bioethics is discussion and debate between people and groups within society. Different sectors of society have been involved in the HGP, from ordinary people, patients, scientists, industry, governments, legal system, regional and international organizations, and the United Nations.

(a) Beneficence: In contemporary ethics, the principle of beneficence signifies an obligation to benefit others or to seek their good and it has been the foundation of many codes. Recalling that, the motive of the HGP is also based on the principle of beneficence to all, be it medical patients, health professionals, public institutions or private companies. Beneficence is the impetus for further research into ways of improving health and agriculture, and for protecting the environment. Beneficence supports the concept of experimentation, if it is performed to lead to possible benefits.

(b) Do no harm: Do no harm is a broad term, but it is the basis for the principles of justice and confidentiality and philanthropy. The judgement in most of the legal systems in the world follow the basic principle of “do no harm”. It is also seen when we address the questions of balancing between benefits and the risks in the use of technologies. Two main ethical arguments in the Human Genome Project revolve around the moral concept of justice and confidentiality that are discussed separately.

(c) Human rights: There are three philosophical schools of thoughts to define what it means to be human. The social school, the developmental school and the genetic or the scientific school. These approaches try to distinguish the human organism from human beings. Human organism is used in the genetic or the scientific sense and human being is used in what may be called its normative, ethical or moral sense. Article 1 of Universal Declaration of Human Rights endows all human beings with reason and conscience, and Article 6 gives all human beings recognition as a person. In simple terms, the human body can not be used as an experimental “organism” without consent. This is enshrined in codes governing medical experimentation, such as the Nuremberg Code and the Helsinki Declaration.

(d) Animal rights: Animal experimentation in biological and medical sciences has been practiced for several millennia. Ethical guidelines for research on non-human animals are based on the assertion that animals are sentient, have conscious experiences, and feel pain and suffering, especially the vertebrate animals. The defenders argue that medical breakthrough come from animal experimentation. Usually the benefits of discoveries to humans generally overweigh the suffering of animals. The statistics of the use of animals can be misleading because the degree of harm varies widely.

Nevertheless, we can not ignore the moral status of animals. The boundaries of the moral obligations are not limited to the members of our own species. Though humans are considered superior in many respects such as self-awareness, rational decision-making, ability to communicate and think, and others, animals cannot be regarded as means of achieving our goals. We do not perform experiments on a severely disabled human either mentally or physically as our means to understand the disease. Macer argues in Bioethics is Love of Life, that the ethical limits of animal use intrinsic ethical factors like pain, self-awareness, future planning, value of being alive and individual love of life. Also extrinsic factors including human necessity or desire, human sensitivity to animal suffering, fertility in humans, other animals disapproval and religious status of animals, are important.

(e) Authority: Many people raised doubts about who should be involved in the sequencing of the genome and who should do the work. The project required a multi-disciplinary approach involving medical experts, biologists, bioethicists, information specialists, computer experts and many others for data banking and analysis. The multidisciplinary authorisation of the Genome Project has on one hand rewarded it with speeding the process, on the other hand it aroused conflict between different groups because of the inherent interests of their respective fields.

(f) Autonomy: The concept of autonomy in bioethics gives each individual the recognition of the human capacity for self-determinism and being different in spite of sharing same DNA which is regarded as a “common heritage”. This is also true in the choices we make.

Personal choices are expressed in law as rights. With the advent of new technologies we have the ethical challenge of respecting people as equals, allowing them to exercise their personal values and decisions. Freedom of expression is parallel to autonomy, but it is debatable that it should not encroach the territory of others.

(g) Ownership: The competition for the genome sequencing between the publically funded Genome Project and the world’s leading private company Celera Genomics is well known. The fear behind this is the unwarranted risk of data ownership. Since it is agreed that all human beings share the same genome, from the ethical perspective, the sequenced data should be owned by all human beings, as it is emphasized in UNESCO’s Universal Declaration of Human Genome and Human Rights.

(h) Justice: The other side of the possibility for transforming medicine is who will actually benefit? Will everyone have access to such revolutionized health care? There is a fear that it might widen the gap between rich and poor. In the developing world, the Human Genome sequencing may not be the first choice for better treatment, where millions of people do not even have access to basic medical treatment. The poor tropical countries could be more interested in deciphering the genomes of disease causing bacteria, viruses or parasites that could provide new target of drugs vaccines or antibiotics. Even in rich countries, not all will benefit equally. It is agreed that it will be extremely difficult and in some cases impossible to provide best treatment to all in need, but a rational and balanced approach is needed so that the people in developing world have their share of benefits from these advancements.

(i) Confidentiality and privacy: It will not be surprising if in the next few years we all will be able to get our individual genomes sequenced. Already distinctive genetic information can be obtained from a simple test. Despite sharing a common genome each individual is distinct in both physical and behavioural characteristics which are determined to some extent by our genes. Those are very personal and confidential to all of us.

The privacy of the genetic information is reinforced not only because of the presumed prospects for the use of such information beyond medical reasons, for instance, discrimination of the “genetic underclass” at different levels, but also to retain the trust with people and respect for person’s autonomy. However, there are exceptions considered by some if it will avoid physical harm to someone, for example.

(j) Responsibility: The responsibility of use or the misuse of the genetic information is an individual decision, but what is useful for one may not be useful for others. The definition of “misuse” is also debatable. So the responsibility of the misuse of genetic information cannot be put on the people involved in genetic research, though private companies may be exceptions depending on the use. If “genetic discrimination” occurs, it will be the fault of social values rather than of the technology.

(k) Scientists and social duty: Scientific freedom to research what scientists desire is included in the fundamental human rights under the UN Declaration of Human Rights, and in the UNESCO Charter. Researchers and scientists have a basic right to experimentation, scientific research and to explore new things. Scientific research and experimentation may not always give the positive, correct or accurate results. Many people regard the HGP as an extension from the desire to know ourselves. Inarguably there are benefits for public good already from the genome projects. But there always lies the danger of misusing scientific freedom. The scientific community has to bear the moral responsibility for using very powerful knowledge, as agreed in the UNESCO Declaration on the Human Genome and Human Rights.

(l) Consequences: The consequences of the HGP are affirmative only when used in a proper way, for the well being of all of humanity. The tremendous potential of the technology is unquestionable. It gives hope and choices for the future. It depends on the action and the motive behind the use of genetic sequencing and further use of the gained genetic information. We have to use the precautionary principle approach, which says we need to be very careful to avoid harm.

 

THE HUMAN GENOME DIVERSITY PROJECT

Описание: HUMAN genom hr

One of the expansions of the HGP, and population genetics, is to explore human diversity, under the Human Genome Diversity Project (HGDP). There are about 5000 ethnic groups in the world with diverse races, cultures, languages and even gene pools. Even to study some of these will help us understand human history. This proposed scientific contribution to world culture has been controversial due to various political, social and ethical reasons. The concept of ethnicity has been exploited in the arguments related to the diversity project, be in favour or against.

The study of genetic epidemiology and the provision of scientific data to population studies, should help us to resolve some anthropological and archaeological questions. These include to identify and help in preventing the loss of endangered populations, reasons for human migration and study of genetic diseases that are unique or prevalent to one population.

The Human Genome Organisation (HUGO) has proposed guidelines to address some of the ethical and legal requirements related to HGDP, which addressed the issues like informed consent, benefits to the sampled populations, confidentiality, intellectual property rights, public understanding and some others. However, these guidelines still failed to address many other issues like easy exploitation of the voluntary altruistic act of contributing the DNA, the danger of commercialization and misuse of genetic heritage by the heads or the local governments

There are also culturally-specific risks that could be identified as intra-community risks, risk to shared identity, risk to established social equilibria and risk to cultural and moral authority.

The ethical concerns are not limited to the above. Some of the ethnic populations are those who live in their own world, away from the scientific and technological world, follow their own cultural and religious beliefs. In that context, the prospects of the HGDP may be biased to the interests of scientific community, rather than upliftment of the targeted communities in their basic livelihood, or at the same time keeping respect for their racial, cultural and religious identities. There may be a long-term danger of eugenics which can not be ignored because eugenic measures often end up with racial or social group overtones, more than breeding from the “best genes”.

The Human Genome Diversity Project has been a catalyst for consideration of the ethical issues that arise during population genetics research, but itself has been plagued by the concerns to the point where the original plan is unlikely to be completed because technical strategies have evolved to help reduce the number of persons who need to be sampled originally the project called for sampling of several dozen representative persons from 500 population groups to assemble genetic linkage maps of each. However, as Resnik discusses, ethical concerns were raised by some representatives of some of these groups, and some other NGOs who had general concerns about genetic research, and over recent trends to patent human genes and cell lines isolated from particular persons.

This paper ethical opportunities rather than problems because I think we have much to learn from the issues raised and the process. Some of the mechanisms developed to answer the concern, such as the notion of group consent, have potential to be used elsewhere.

The attention paid to the HGDP has made population geneticists more cautious of the types of projects they conduct, and made the ethical review more concrete. We have seen the emergence of guidelines, including the Human Genome Organization (HUGO) Ethics Committee (1997), Statement of Principled Conduct of Genetic Research, which is being applied to genetics research in general. Ironically, probably the HGDP with the attention it pays to ethics review will have less ethical problems than most population genetics and anthropology research that continues today, so these researchers still have more to learn from the debate over the HGDP.

Personally, the HGDP was also an ethical opportunity to learn of more diverse views over a scientific project. The need to support diversity is well recognized in international law, but not always in ethics or practice. My work in generating dialogue and revising drafts of a UNESCO International Bioethics Committee (IBC) subcommittee report on population genetics gave me the privilege to meet and contact sincere individuals on both sides of the debate. More clearly, the UNESCO report did not support the HGDP; rather it raised a number of ethical issues and gave a balanced view. Sadly, the opportunity for ethical dialogue at an international level by a mixed committee of all sides has been stalled since 1997 (Macer et al., 1998), and the issues are being addressed, or not, on regional level in a way which still has some critics.

Resnik (1999) has raised some of the major concerns and presents some discussion, and solutions to the problems, namely racism, gene patenting, exploitation, protecting indigenous cultures and people, informed consent and group consent. I will just discuss some of these and supplementary issues in terms of the opportunities presented.

Some of the other ethical issues of population genetics research addressed by the UNESCO report include: How to obtain free and informed consent from individuals and groups; Selection and participation; Use of the knowledge gained; Return of benefits to participants; Clash of world-views; Does the right not to know apply to communities? Who speaks for a community?

Ownership of genes and derived knowledge; Public understanding and racism or eugenics; stigmatization and genetic reductionism; and International oversight of anthropologists and geneticists.

The key points of the UNESCO report were:

(i) No endorsement of a particular population genetic project;

(ii) Call for establishment of a separate ethical committee that is available to all population genetics researchers;

(iii) Discussion of variety of ethical, ethnic and social issues.

Although there is scientific evidence to suggest that there will be little population genetic diversity found that is unique to one particular group, there is also a logical possibility that there may be distinct genetic features that make one genetic group distinct from others. The fact is that, while eugenics was founded on racism, eugenics today does not have to be linked with racism. Those who continue to link their eugenics with racism will not be dissuaded by scientific evidence, since racism is an attitude of mind, or prejudice.

Current population genetics research is under the oversight of different layers of control which vary widely around the world. This oversight ranges from the discretion of individual researchers, consent from the persons who provide the tissue samples, consent from the groups being studied, to several layers of ethical committee. International regulations on research involving human subjects are clear that informed consent is needed. Some funding agencies demand ethical review, such as NIH-funded research in the USA, and here the NRC Report discussed by Resnik has its biggest impact. Some universities in the world also demand ethical review, and the trend is to have more review.

The HGDP makes us consider our roots and their importance (or not) in modern society.

There are a few thousand population groups in the world, only some members of these are active as indigenous people. “How many generations link you to your home?” is related to the definition of who is indigenous ? Maybe all people are indigenous to somewhere; however, minority groups have reason to be more afraid of abuses than those of a majority. The alleged abuses of genetics that they raise are relevant to us all, as they raise questions of how the knowledge will be used as well as how the research will be conducted?

Some of the ethical issues related to human genetics in general, such as the use of genetic data in prenatal diagnosis (Macer, 1998). Some data may be useful for developing genetic tests, and an important issue is commercialization and use of the results of the collected DNA and cells. Financial returns are not the only form of benefits of research results, which could be returned to subjects of research. The feedback of results to the communities concerned should also help to foster a greater sense of community identity in the face of aggressive cultural imperialism by industrial superpowers. But perhaps the most poignant problems of many populations involved in population genetics research is in the realm of public health. The provision of health and medical care, however, should be appropriate to the cultural and social context of the community and should be sustained.

At the community level, the health data could be utilized as an ethical opportunity for the improvement of local community health. Thus, benefits should also flow back to the groups and communities in the form of contributing to the formulation and implementation of local and national health care policies that would enable communities to better their positions. Commercial benefits could be expressed in other ways. While there could also be provision for a one-time gift of cells or blood with no conditions, as is found in some tissue donation forms for blood and body tissues, can one individual sign away commercial rewards to future research knowledge for the population to which they belong? It may be technically possible to conduct the new HGDP, as population genetics research among students of an international university, with them giving their cells to science, and whether their group like it or not, the students represent their population.

The application of the ethical principle of informed consent and respect for integrity is a complex process at the level of populations. In order to ensure that the potential subjects understand the goals of research, the risks involved, the use to which research results could be put, and the rights of the groups and individuals under study, careful consideration is needed. If group consent is accepted, it is then a task to identify the most appropriate persons with whom to communicate, the persons from whom clearance should be obtained, and the appropriate content and media of communication. Research will need to take account of the group’s social organization, goals and aspirations, cultural values, and laws (both statutory and customary).

Various groups of indigenous peoples have expressed their irritation with past population genetics research, which they claim has been conducted without prior consultation and in a way where consent was obtained in terms inconsistent with their cultural norms. In this respect the HGDP presents an opportunity for dialogue and ethical research, even if a population decides not to be a part of the research, this will be an accomplishment in bioethics in itself. The Mataatua Declaration on Cultural and Intellectual Property Rights of Indigenous Peoples of June 1993 (5) called for a halt to the HGDP until its impact has been discussed. Article 3.5 of the Declaration calls “for an immediate halt to the ongoing ‘Human Genome Diversity Project’ (HUGO) until its moral, ethical, socio-economic, physical and political implications have been thoroughly discussed, understood and approved by indigenous peoples”. The Declaration is actually not anti-science, and includes a call for involvement in scientific research, recommendation 2.11, “Ensure current scientific environmental research is strengthened by increasing the knowledge of indigenous communities and to customary environmental knowledge”.

If this opportunity is taken for researchers to be subject to greater scrutiny, the same holds true for the media whose duty of honest, scientific reporting and preservation of privacy needs to be underscored. Whole populations, communities and the researchers themselves have often been wrongly depicted and wrongly represented with the resulting unjust labeling and discrimination. Such practices only serve to undermine public confidence and participation in research. Let us hope that all will be responsible.

The need for a strategic framework

The Universal Declaration on Human Rights in 1948, has given ethical parameters an objective mode to justice and the decision-making. They are regarded as fundamental rights to all human beings and invigilate a wide spectrum of basic human requirements.

There were various public and professional regulatory policies formulated since the beginning of the HGP, seeing its wide implications. The HGP did not arise from the consensus by all scientists or doctors that information was badly needed, rather it was initiated within the U.S. Department of Energy. So, the project owes its existence to the government that advocated the project, even though human genetics would have eventually reached the same goal. A major objection to the policies, was who should formulate the policies? It is for society to decide how much of its wealth is devoted to scientific research. Once the decision is made there should be justifiable medical and scientific reasons for allocating the funds. There might be nothing wrong with the concept, or the technology is judged adequate, but still there remains the question as to whether or not it is reasonable to divert the allocation of resource from other activities to mega sequencing of the genome.

The present policies reflect the criteria to tackle the immediate or the short term effects, for example, for medical uses or discrimination. They are more individual person oriented. But there is still a need for policies that could prelude the consequences of the genome sequencing in the long term.

The majority of the policies primarily are focussed or shadowed by the legal systems in the individual countries which are dominant players in the project. The need for international approaches (including education and guidelines) is based on several arguments: shared biological heritage and destiny of human beings in all “nations”; the transitory nature of “nations” and the precedents for international law to protect the common interest of humanity; the common perceptions and the bioethical reasoning of peoples around the world — universal bioethics.

There is a need for a universal strategic framework, given the globalisation and overlapping interests of government, social and business sectors, although we may also say that some of the misunderstandings and doubtful presumptions crop up because the overarching principles, rights and duties defined by our laws, can sometimes be too much. The need is for a framework that is representative of the interests of all the concerned people directly or indirectly involved, a framework that is based on the principles of ethics and moral boundaries that value respect for humanity as their foremost principle.

Описание: andrew-paul-leondard-stem

STEM CELLS RESEARCH

Research Ethics and Stem Cells

Stem cells show potential for many different areas of health and medical research, and studying them can help us understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are caused by problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.

Research on one kind of stem cell—human embryonic stem cells—has generated much interest and public debate. Pluripotent stem cells (cells that can develop into many different cell types of the body) are isolated from human embryos that are a few days old. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development).

As science and technology continue to advance, so do ethical viewpoints surrounding these developments. It is important to educate and explore the issues, scientifically and ethically.

Introduction

Research on stem cells is advancing knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms. This promising area of science is also leading scientists to investigate the possibility of cell-based therapies to treat disease, which is often referred to as regenerative or reparative medicine.

Stem cells are one of the most fascinating areas of biology today. But like many expanding fields of scientific inquiry, research on stem cells raises scientific questions as rapidly as it generates new discoveries.

The NIH developed this primer to help readers understand the answers to questions such as: What are stem cells? What different types of stem cells are there and where do they come from? What is the potential for new medical treatments using stem cells? What research is needed to make such treatments a reality?

Stem cells have two important characteristics that distinguish them from other types of cells. First, they are unspecialized cells that renew themselves for long periods through cell division. The second is that under physiologic or experimental conditions, they can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulinproducing cells of the pancreas.

Scientists primarily work with two kinds of stem cells from animals and humans: embryonic stem cells and adult stem cells, which have different functions and characteristics that will be explained in this document. Scientists discovered ways to obtain or derive stem cells from early mouse embryos more than 20 years ago. Many years of detailed study of the biology of mouse stem cells led to the discovery, in 1998, of how to isolate stem cells from human embryos and grow the cells in the laboratory. These are called human embryonic stem cells. The embryos used in these studies were created for infertility purposes through in vitro fertilization procedures and when they were no longer needed for that purpose, they were donated for research with the informed consent of the donor.

Stem cells are important for living organisms for many reasons. In the 3-to-5-dayold embryo, called a blastocyst, stem cells in developing tissues give rise to the multiple specialized cell types that make up the heart, lung, skin, and other tissues. In some adult tissues, such as bone marrow, muscle, and brain, discrete populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease.

It has been hypothesized by scientists that stem cells may, at some point in the future, become the basis for treating diseases such as Parkinson’s disease, diabetes, and heart disease.

Scientists want to study stem cells in the laboratory so they can learn about their essential properties and what makes them different from specialized cell types. As scientists learn more about stem cells, it may become possible to use the cells not just in cell-based therapies, but also for screening new drugs and toxins and understanding birth defects.

However, as mentioned above, human embryonic stem cells have only been studied since 1998. Therefore, in order to develop such treatments scientists are intensively studying the fundamental properties of stem cells, which include:

(i) determining precisely how stem cells remain unspecialized and self renewing for many years; and

(ii) identifying the signals that cause stem cells to become specialized cells.

What are the unique properties of all stem cells?

Stem cells differ from other kinds of cells in the body. All stem cells—regardless of their source—have three general properties: they are capable of dividing and renewing themselves for long periods; they are unspecialized; and they can give rise to specialized cell types.

Scientists are trying to understand two fundamental properties of stem cells that relate to their long-term self-renewal:

(i) Why can embryonic stem cells proliferate for a year or more in the laboratory without differentiating, but most adult stem cells cannot; and

(ii) What are the factors in living organisms that normally regulate stem cell proliferation and self-renewal?

Discovering the answers to these questions may make it possible to understand how cell proliferation is regulated during normal embryonic development or during the abnormal cell division that leads to cancer. Importantly, such information would enable scientists to grow embryonic and adult stem cells more efficiently in the laboratory.

(a) Stem cells are unspecialized: One of the fundamental properties of a stem cell is that it does not have any tissue-specific structures that allow it to perform specialized functions. A stem cell cannot work with its neighbors to pump blood through the body (like a heart muscle cell); it cannot carry molecules of oxygen through the bloodstream (like a red blood cell); and it cannot fire electrochemical signals to other cells that allow the body to move or speak (like a nerve cell). However, unspecialized stem cells can give rise to specialized cells, including heart muscle cells, blood cells, or nerve cells.

(b) Stem cells are capable of dividing and renewing themselves for long periods: Unlike muscle cells, blood cells, or nerve cells—which do not normally replicate themselves—stem cells may replicate many times. When cells replicate themselves many times over it is called proliferation. A starting population of stem cells that proliferates for many months in the laboratory can yield millions of cells. If the resulting cells continue to be unspecialized, like the parent stem cells, the cells are said to be capable of long-term self-renewal.

The specific factors and conditions that allow stem cells to remain unspecialized are of great interest to scientists. It has taken scientists many years of trial and error to learn to grow stem cells in the laboratory without them spontaneously differentiating into specific cell types.

For example, it took 20 years to learn how to grow human embryonic stem cells in the laboratory following the development of conditions for growing mouse stem cells. Therefore, an important area of research is understanding the signals in a mature organism that cause a stem cell population to proliferate and remain unspecialized until the cells are needed for repair of a specific tissue. Such information is critical for scientists to be able to grow large numbers of unspecialized stem cells in the laboratory for further experimentation.

(c) Stem cells can give rise to specialized cells: When unspecialized stem cells give rise to specialized cells, the process is called differentiation. Scientists are just beginning to understand the signals inside and outside cells that trigger stem cell differentiation. The internal signals are controlled by a cell’s genes, which are interspersed across long strands of DNA, and carry coded instructions for all the structures and functions of a cell. The external signals for cell differentiation include chemicals secreted by other cells, physical contact with neighboring cells, and certain molecules in the microenvironment.

Therefore, many questions about stem cell differentiation remain. For example, are the internal and external signals for cell differentiation similar for all kinds of stem cells? Can specific sets of signals be identified that promote differentiation into specific cell types? Addressing these questions is critical because the answers may lead scientists to find new ways of controlling stem cell differentiation in the laboratory, thereby growing cells or tissues that can be used for specific purposes including cell-based therapies.

Adult stem cells typically generate the cell types of the tissue in which they reside. A blood-forming adult stem cell in the bone marrow, for example, normally gives rise to the many types of blood cells such as red blood cells, white blood cells and platelets. Until recently, it had been thought that a blood-forming cell in the bone marrow—which is called a hematopoietic stem cell—could not give rise to the cells of a very different tissues, such as nerve cells in the brain. However, a number of experiments over the last several years have raised the possibility that stem cells from one tissue may be able to give rise to cell types of a completely different tissue, a phenomenon known as plasticity. Examples of such plasticity; include blood cells becoming neurons, liver cells that can be made to produce insulin, and hematopoietic stem cells that can develop into heart muscle. Therefore, exploring the possibility of using adult stem cells for cell-based therapies has become a very active area of investigation by researchers.

STAGES OF EARLY EMBRYONIC DEVELOPMENT ARE IMPORTANT FOR GENERATING EMBRYONIC STEM CELLS

Embryonic stem cells, as their name suggests, are derived from embryos. Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman’s body.

The embryos from which human embryonic stem cells are derived are typically four or five days old and are a hollow microscopic ball of cells called the blastocyst. The blastocyst includes three structures: the trophoblast, which is the layer of cells that surrounds the blastocyst; the blastocoel, which is the hollow cavity inside the blastocyst; and the inner cell mass, which is a group of approximately 30 cells at one end of the blastocoel.

How are embryonic stem cells grown in the laboratory?

Growing cells in the laboratory is known as cell culture. Human embryonic stem cells are isolated by transferring the inner cell mass into a plastic laboratory culture dish that contains a nutrient broth known as culture medium. The cells divide and spread over the surface of the dish. The inner surface of the culture dish is typically coated with mouse embryonic skin cells that have been treated so they will not divide. This coating layer of cells is called a feeder layer. The reason for having the mouse cells in the bottom of the culture dish is to give the inner cell mass cells a sticky surface to which they can attach. Also, the feeder cells release nutrients into the culture medium. Recently, scientists have begun to devise ways of growing embryonic stem cells without the mouse feeder cells. This is a significant scientific advancement because of the risk that viruses or other macromolecules in the mouse cells may be transmitted to the human cells.

Over the course of several days, the cells of the inner cell mass proliferate and begin to crowd the culture dish. When this occurs, they are removed gently and plated into several fresh culture dishes. The process of replating the cells is repeated many times and for many months, and is called subculturing. Each cycle of subculturing the cells is referred to as a passage. After six months or more, the original 30 cells of the inner cell mass yield millions of embryonic stem cells. Embryonic stem cells that have proliferated in cell culture for six or more months without differentiating, are pluripotent, and appear genetically normal are referred to as an embryonic stem cell line.

Once cell lines are established, or even before that stage, batches of them can be frozen and shipped to other laboratories for further culture and experimentation.

What laboratory tests are used to identify embryonic stem cells?

At various points during the process of generating embryonic stem cell lines, scientists test the cells to see whether they exhibit the fundamental properties that make them embryonic stem cells. This process is called characterization.

As yet, scientists who study human embryonic stem cells have not agreed on a standard battery of tests that measure the cells’ fundamental properties. Also, scientists acknowledge that many of the tests they do use may not be good indicators of the cells’ most important biological properties and functions. Nevertheless, laboratories that grow human embryonic stem cell lines use several kinds of tests. These tests include:

• growing and subculturing the stem cells for many months. This ensures that the cells are capable of long-term self-renewal. Scientists inspect the cultures through a microscope to see that the cells look healthy and remain undifferentiated.

• using specific techniques to determine the presence of surface markers that are found only on undifferentiated cells. Another important test is for the presence of a protein called Oct-4, which undifferentiated cells typically make. Oct-4 is a transcription factor, meaning that it helps turn genes on and off at the right time, which is an important part of the processes of cell differentiation and embryonic development.

• examining the chromosomes under a microscope. This is a method to assess whether the chromosomes are damaged or if the number of chromosomes has changed. It does not detect genetic mutations in the cells.

• determining whether the cells can be subcultured after freezing, thawing, and replating.

• testing whether the human embryonic stem cells are pluripotent by allowing the cells to differentiate spontaneously in cell culture; manipulating the cells so they will differentiate to form specific cell types; or injecting the cells into an immunosuppressed mouse to test for the formation of a benign tumor called a teratoma. Teratomas typically contain a mixture of many differentiated or partly differentiated cell types—an indication that the embryonic stem cells are capable of differentiating into multiple cell types.

As long as the embryonic stem cells in culture are grown under certain conditions, they can remain undifferentiated (unspecialized). But if cells are allowed to clump together to form embryoid bodies, they begin to differentiate spontaneously. They can form muscle cells, nerve cells, and many other cell types: Although spontaneous differentiation is a good indication that a culture of embryonic stem cells is healthy, it is not an efficient way to produce cultures of specific cell types.

So, to generate cultures of specific types of differentiated cells—heart muscle cells, blood cells, or nerve cells, for example—scientists try to control the differentiation of embryonic stem cells. They change the chemical composition of the culture medium, alter the surface of the culture dish, or modify the cells by inserting specific genes.

What are adult stem cells?

An adult stem cell is an undifferentiated cell found among differentiated cells in a tissue or organ, can renew itself, and can differentiate to yield the major specialized cell types of the tissue or organ. The primary roles of adult stem cells in a living organism are to maintain and repair the tissue in which they are found. Some scientists now use the term somatic stem cell instead of adult stem cell. Unlike embryonic stem cells, which are defined by their origin (the inner cell mass of the blastocysts), the origin of adult stem cells in mature tissues is unknown.

Research on adult stem cells has recently generated a great deal of excitement. Scientists have found adult stem cells in many more tissues than they once thought possible. This finding has led scientists to ask whether adult stem cells could be used for transplants. In fact, adult blood forming stem cells from bone marrow have been used in transplants for 30 years. Certain kinds of adult stem cells seem to have the ability to differentiate into a number of different cell types, given the right conditions. If this differentiation of adult stem cells can be controlled in the laboratory, these cells may become the basis of therapies for many serious common diseases.

The history of research on adult stem cells began about 40 years ago. In the 1960s, researchers discovered that the bone marrow contains at least two kinds of stem cells. One population, called hematopoietic stem cells, forms all the types of blood cells in the body. A second population, called bone marrow stromal cells, was discovered a few years later. Stromal cells are a mixed cell population that generates bone, cartilage, fat, and fibrous connective tissue.

Also in the 1960s, scientists who were studying rats discovered two regions of the brain that contained dividing cells, which become nerve cells. Despite these reports, most scientists believed that new nerve cells could not be generated in the adult brain. It was not until the 1990s that scientists agreed that the adult brain does contain stem cells that are able to generate the brain’s three major cell types—astrocytes and oligodendrocytes, which are nonneuronal cells, and neurons, or nerve cells.

Where are adult stem cells found and what do they normally do?

Adult stem cells have been identified in many organs and tissues. One important point to understand about adult stem cells is that there are a very small number of stem cells in each tissue. Stem cells are thought to reside in a specific area of each tissue where they may remain quiescent (non-dividing) for many years until they are activated by disease or tissue injury. The adult tissues reported to contain stem cells include brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin and liver.

Scientists in many laboratories are trying to find ways to grow adult stem cells in cell culture and manipulate them to generate specific cell types so they can be used to treat injury or disease. Some examples of potential treatments include replacing the dopamine-producing cells in the brains of Parkinson’s patients, developing insulin-producing cells for type I diabetes and repairing damaged heart muscle following a heart attack with cardiac muscle cells.

What tests are used for identifying adult stem cells?

Scientists do not agree on the criteria that should be used to identify and test adult stem cells. However, they often use one or more of the following three methods:

(a) Labelling the cells in a living tissue with molecular markers and then determining the specialized cell types they generate.

(b) Removing the cells from a living animal, labelling them in cell culture, and transplanting them back into another animal to determine whether the cells repopulate their tissue of origin and

(c) Isolating the cells, growing them in cell culture, and manipulating them, often by adding growth factors or introducing new genes, to determine what differentiated cells types they can become.

Also, a single adult stem cell should be able to generate a line of genetically-identical cells — known as a clone—which then gives rise to all the appropriate differentiated cell types of the tissue. Scientists tend to show either that a stem cell can give rise to a clone of cells in cell culture, or that a purified population of candidate stem cells can repopulate the tissue after transplant into an animal. Recently, by infecting adult stem cells with a virus that gives a unique identifier to each individual cell, scientists have been able to demonstrate that individual adult stem cell clones have the ability to repopulate injured tissues in a living animal.

What is known about adult stem cell differentiation?

As indicated above, scientists have reported that adult stem cells occur in many tissues and that they enter normal differentiation pathways to form the specialized cell types of the tissue in which they reside. Adult stem cells may also exhibit the ability to form specialized cell types of other tissues, which is known as transdifferentiation or plasticity.

Normal differentiation pathways of adult stem cells. In a living animal, adult stem cells can divide for a long period and can give rise to mature cell types that have characteristic shapes and specialized structures and functions of a particular tissue. The following are examples of differentiation pathways of adult stem cells (Fig. 4.2).

Hematopoietic stem cells give rise to all the types of blood cells: red blood cells, B lymphocytes, T lymphocytes, natural killer cells, neutrophils, basophils, eosinophils, monocytes, macrophages, and platelets.

Bone marrow stromal cells (mesenchymal stem cells) give rise to a variety of cell types :

bone cells (osteocytes), cartilage cells (chondrocytes), fat cells (adipocytes), and other kinds of connective tissue cells such as those in tendons.

Neural stem cells in the brain give rise to its three major cell types: nerve cells (neurons) and two categories of non-neuronal cells—astrocytes and oligodendrocytes.

Epithelial stem cells in the lining of the digestive tract occur in deep crypts and give rise to several cell types: absorptive cells, goblet cells, Paneth cells, and enteroendocrine cells.

Skin stem cells occur in the basal layer of the epidermis and at the base of hair follicles.

The epidermal stem cells give rise to keratinocytes, which migrate to the surface of the skin and form a protective layer. The follicular stem cells can give rise to both the hair follicle and the epidermis.

Adult stem cell plasticity and transdifferentiation. A number of experiments have suggested that certain adult stem cell types are pluripotent. This ability to differentiate into multiple cell types is called plasticity or transdifferentiation. The following list offers examples of adult stem cell plasticity that have been reported during the past few years:

Hematopoietic stem cells may differentiate into: three major types of brain cells (neurons, oligodendrocytes, and astrocytes); skeletal muscle cells; cardiac muscle cells; and liver cells. Bone marrow stromal cells may differentiate into: cardiac muscle cells and skeletal muscle cells.

Brain stem cells may differentiate into: blood cells and skeletal muscle cells.

Current research is aimed at determining the mechanisms that underlie adult stem cell plasticity. If such mechanisms can be identified and controlled, existing stem cells from a healthy tissue might be induced to repopulate and repair a diseased tissue.

What are the key questions about adult stem cells?

Many important questions about adult stem cells remain to be answered. They include :

• How many kinds of adult stem cells exist, and in which tissues do they exist?

• What are the sources of adult stem cells in the body? Are they “leftover” embryonic stem cells, or do they arise in some other way? Why do they remain in an differentiated state when all the cells around them have differentiated?

• Do adult stem cells normally exhibit plasticity, or do they only transdifferentiate when scientists manipulate them experimentally? What are the signals that regulate the proliferation and differentiation of stem cells that demonstrate plasticity?

• Is it possible to manipulate adult stem cells to enhance their proliferation so that sufficient tissue for transplants can be produced?

• Does a single type of stem cell exist—possibly in the bone marrow or circulating in the blood—that can generate the cells of any organ or tissue?

• What are the factors that stimulate stem cells to relocate to sites of injury or damage?

Applications of stem cells

There are many ways in which human stem cells can be used in basic research and in clinical research. However, there are many technical hurdles between the promise of stem cells and the realization of these uses, which will only be overcome by continued intensive stem cell research.

Studies of human embryonic stem cells may yield information about the complex events that occur during human development. A primary goal of this work is to identify how undifferentiated stem cells become differentiated. Scientists know that turning genes on and off is central to this process. Some of the most serious medical conditions, such as cancer and birth defects, are due to abnormal cell division and differentiation. A better understanding of the genetic and molecular controls of these processes may yield information about how such diseases arise and suggest new strategies for therapy. A significant hurdle to this use and most uses of stem cells is that scientists do not yet fully understand the signals that turn specific genes on and off to influence the differentiation of the stem cell.

Human stem cells could also be used to test new drugs. For example, new medications could be tested for safety on differentiated cells generated from human pluripotent cell lines.

Other kinds of cell lines are already used in this way. Cancer cell lines, for example, are used to screen potential anti-tumor drugs. But, the availability of pluripotent stem cells would allow drug testing in a wider range of cell types. However, to screen drugs effectively, the conditions must be identical when comparing different drugs. Therefore, scientists will have to be able to precisely control the differentiation of stem cells into the specific cell type on which drugs will be tested. Current knowledge of the signals controlling differentiation fall well short of being able to mimic these conditions precisely to consistently have identical differentiated cells for each drug being tested.

Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases including Parkinson’s and Alzheimer’s diseases, spinal-cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.

For example, it may become possible to generate healthy heart muscle cells in the laboratory and then transplant those cells into patients with chronic heart disease. Preliminary research in mice and other animals indicates that bone marrow stem cells, transplanted into a damaged heart, can generate heart muscle cells and successfully repopulate the heart tissue.

Other recent studies in cell culture systems indicate that it may be possible to direct the differentiation of embryonic stem cells or adult bone marrow cells into heart muscle cells.

In people who suffer from type I diabetes, the cells of the pancreas that normally produce insulin are destroyed by the patient’s own immune system. New studies indicate that it may be possible to direct the differentiation of human embryonic stem cells in cell culture to form insulin-producing cells that eventually could be used in transplantation therapy for diabetics.

To realize the promise of novel cell-based therapies for such pervasive and debilitating diseases, scientists must be able to easily and reproducibly manipulate stem cells so that they possess the necessary characteristics for successful differentiation, transplantation and engraftment.

The following is a list of steps in successful cell-based treatments that scientists will have to learn to precisely control to bring such treatments to the clinic. To be useful for transplant purposes, stem cells must be reproducibly made to:

• proliferate extensively and generate sufficient quantities of tissue;

• differentiate into the desired cell type(s);

• survive in the recipient after transplant;

• integrate into the surrounding tissue after transplant;

• function appropriately for the duration of the recipient’s life;

• avoid harming the recipient in any way.

Also, to avoid the problem of immune rejection, scientists are experimenting with different research strategies to generate tissues that will not be rejected.

To summarize, the promise of stem-cell therapies is an exciting one, but significant technical hurdles remain that will only be overcome through years of intensive research.

Описание: stem-cells

BIOETHICS INVOLVED IN STEM-CELL RESEARCH

Stem cells show potential for many different areas of health and medical research, and studying them can help us understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are caused by problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.

Research on one kind of stem cell—human embryonic stem cells—has generated much interest and public debate. Pluripotent stem cells (cells that can develop into many different cell types of the body) are isolated from human embryos that are a few-days old. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development).

As science and technology continue to advance, so do ethical viewpoints surrounding these developments. It is important to educate and explore the issues, scientifically and ethically.

(a) Humanitarian-Hopes

Powerful motivation for setting our minds to this task comes from the vision of scientists about what regenerative medicine might accomplish with stem cells derived from embryos.

Shortly after the discovery in 1998, of ways to nurture embryonic stem cells in the laboratory, the Director of the National Institute of Health, Harold Varmus, M.D., described the promise of this frontier in testimony before Congress. The embryonic stem cells of which Dr. Varmus spoke differ from the stem cells of developed humans (the latter often called “adult” stem cells). Embryonic stem cells possess the attribute of pluripotency, which is to say that they may issue in more than one cell type. Cells in the developed human, so far as is known, are not pluripotent.

More information about the scientific promise of pluripotent embryonic stem cells may be learned from resources on human embryonic stem cells collected by the University of Wisconsin.

(b) Moral Debate Concerning Embryonic Stem Cell Research

Our task is to decide how we should act toward an embryo, and whether we should recognize, as we do among adults, distinctions between embryos of various types and in various circumstances. We immediately encounter the question of what beings we should classify as “persons” for purposes of the duty not to kill persons. Answering that question with the view that not every embryo should be classified as a person for purposes of that duty, the Protestant theologian Ronald Cole-Turner, M. Div., Ph.D., has offered a Christian moral defence of humanitarian embryo use.

Use of cell-cultures as alternatives to use of animals

Alternatives to use of animals are tests and procedures that incorporate replacement, reduction or refinement of animal use commonly referred to as three Rs. The concept of alternatives was first defined by WMS Russell and Rex Burch in their book entitled “The Principles of Humane Experimental Technique” published in 1959. The original definition given by the authors is as follows:

“Replacement means the substitution for conscious living higher animals of insentient material. Reduction means reduction in the numbers of animals used to obtain information of given amount and precision. Refinement means any decrease in the incidence or severity of inhumane procedures applied to those animals which still have to be used”.

However, in the recent years the term alternative techniques has come into common usage with different meanings to different people. To many biomedical researchers, it refers to those which can be used in addition to the more traditional animal models. On the other hand some people refer the term alternative to those techniques, which can entirely replace the use of animals. Significant advances in the field of scientific research particularly molecular biology and information technology have helped in the development of alternative techniques in the past two decades.

Alternative techniques and approaches, addressing the broad issues of three Rs are explained below with some specific examples.

Replacement

Alternatives which replace animal models could be broadly classified into the use of living systems, nonliving systems and computer simulation.

Use of Living Systems

(a) In vitro techniques : The most commonly recognized non-animal living systems are in vitro systems such as cell, tissue, and organ cultures. These in vitro systems isolate the system under study from the rest of the organism and are ideal for mechanistic investigations where it is desirable to avoid the confounding effects of systemic influences such as hormones.

This can, however, be a disadvantage when these external factors have a crucial effect on the question being studied. These in vitro systems techniques are not seen as absolute replacement but only a relative replacement alternative, because they require freshly-obtained animal cells and tissue. However, even when freshly-isolated material is required, the animals are used more economically, because a single animal will provide tissue for a number of cultures.

The use of cell cultures can be more economical than the use of whole animals, once the necessary investment has been made to obtain the required experience and expertise. Cell culture studies can often be carried out in multi-well plates in order to enable data collection to be partially or fully automated. Primary cell cultures are produced from fresh tissue which has been disrupted so as to obtain individual cells. These cultures are fairly easy to set up, and they start with the advantage that they contain normal cells with all the characteristics that determine their specialised functions in the tissue of origin. However, they can only be maintained for a limited period of a few days, or perhaps weeks, and they tend lose their functional capacity with time. This means that further fresh tissue is constantly required and that the cultures cannot be used for long-term studies.

As compared to primary cell cultures, cell line cultures consist of cells which can keep on growing indefinitely. These cells are often derived from human or animal tumors, and some have been maintained for decades. They may under go transformation, which makes them insensitive to the control mechanisms that limit the number of times that normal cells can divide before dying. Cell lines can be bought as required, and a stock can be kept frozen in liquid nitrogen. They are widely used, because they are easy to maintain and do not require the use of tissue. However, it has not been possible to produce cell lines from every type of tissue. A further disadvantage is that the cells are abnormal in many ways and in some cases, they show no resemblance at all to normal cells from the tissue of origin. Efforts have also been developed embryonic stem cell lines which remain undifferentiated until induced to differentiate by a change in culture conditions. They are being investigated for their potential in teratogenicity testing and are also being used for gene knock-out studies to identify the role of defined genes.

Through the introduction of viral oncogenes into primary cells, it is possible to produce immortalised cell lines which maintain the characteristics of differentiated cells but can be cultured for much longer.

Cell lines can be genetically engineered in a number of ways, for example genes can be introduced to obtain the expression of receptors on the cell surface, shuttle vectors can be introduced as target DNA for genotoxicity studies, and human genes can be inserted into an animal cell line to give it the enzymatic capability of human tissues. The use of tissues or their fragments has also been attempted to replace the use of whole animal. For example, very thin slices of liver and kidney can be used to study the possible effects of drugs on these organs. Sometimes the tissue making up one part of an organ is cultured separately, for example the proximal tubules of the kidney. These systems are still economical in their use of animals and human tissue obtained after surgery may also be used in some cases. However, these cultures have a limited life span and a high level of technical skill is required to set up and maintain them. In some cases, three-dimensional tissue equivalents may be used instead of tissue cultures. These are systems in which it is possible to mimic tissue architecture by culturing cells on an artificial support matrix. A number of human skin equivalents have been developed, and work is in progress on tissue for various types of research and human placenta is one of them. However, whenever human tissue is used it can be difficult to obtain, store and distribute. Also it requires greater precautions to avoid risk arising due to presence of viruses (e.g., HIV/AIDS). Establishment of tissue banks for human tissue that is unsuitable for transplantation can solve the problems of its supply.

Organ cultures have the advantage of enabling all the interactions which take place within the organ, and they are extensively used in pharmacological studies. However, they are difficult to maintain, short-lived, and use many animals, because one animal can only provide one organs (or two in the case of kidneys).

It may be noted that although, intercellular and intracellular interactions that can be studied are more close to those in whole animals as the level of anatomy increases i.e., in cells, tissues and organs (Fig. 4.4), but it is difficult to maintain the tissue and the organ cultures in the laboratory as compared to cell cultures. Therefore, the cell culture techniques are most commonly used especially for monoclonal antibody production, virus vaccine production, vaccine potency testing, screening for the cytopathic effects of various compounds and studying the function and make up of cell membranes. The potential uses of in vitro techniques are almost limitless and will continue to expand as more is learned about the various organs and their component tissues and cells, and as the technology of maintaining in vitro environments improves.

(b) Invertebrate animals : Invertebrates represent over 90% of known plant species on the earth. Although their body structure is quite different to humans than as compared to verteb-rates body’s structure, invertebrate anatomy, physiology, biochemistry and other metabolic functions can be used to replace the more commonly used laboratory animals. An invertebrate which has long been used in biomedical research is the fruit fly, Drosophila melanogaster — a classic model for the study of genetics. This species also can be used for detecting mutagenicity, teratogenicity and reproductive toxicity. The marine invertebrates represent different species which have not been widely investigated. However in neurobiology a number of different marine species have been well characterized and used to study the physiology of the nervous system.

(c) Microorganisms : The microorganisms represent a third system, which has been used to replace traditional animal models. The Ames mutagenicity/carcinogenicity test uses Salmonella typhimurium cultures to screen compounds that formerly required the use of animals.

This test has been validated and accepted for screening purposes in regulatory toxicology.

Similarly, the Litmus amoebocyte Lysate (LAL) test for endotoxins has also been validated and accepted for certain regulatory purposes to detect the presence of embryogenic fever-inducing endotoxins. A host of microscopic protozoans and metazoans have been used in biomedical research.

The advantage of using microorganisms include their repair division and growth body temperature which helps in multi-generational studies in a short period of time. They are also cost-effective in terms of storage, upkeep and maintenance. However, the major disadvantages is that they are unicellular organisms and the interaction of cells cannot be studied.

Use of Non-living Systems

The non-living systems used as alternative involve the use of physicochemical, analytical and molecular techniques and in silica systems.

(a)             Physico-chemical methods: Physico-chemical methods are extensively used in initial ages of various screening studies. For example, pH and partition coefficient in combination with structure-activity relationships help in predicting the likely biological effects of chemicals. The commercial Ocular Irritation Assay System uses a proprietary reagent solution that is com-posed of proteins, glycoproteins, lipids and low molecular weight components that self-associate to form a complex macromolecular metric. The potential of a chemical to irritate the eyes is predicted by the extent to which it will coagulate the reagent. Many cosmetics companies use this system to screen out potential irritants without testing them in animals.

Immuno-chemical techniques use the binding capacity of highly-specific antibodies to seek out minute quantities of antigen. A classical example of this technique can be demonstrated by the currently used techniques for identifying bacterial toxins. Toxin identification previously required the injection of as many as several hundred mice with supernatant from cultures of suspected contaminating bacteria. These new antibody techniques save animals and speed up confirmation of a tentative diagnosis. By adding a colour marker to the enzyme-linked immunosorbent assay system (ELISA), the whole process becomes a commercially available test kit such as those used in home pregnancy detection.

(b) Molecular methods: Molecular methods as an alternative are based on studying the molecular interaction of test compound with DNA. For example, technology to rapidly analyse DNA from patients and identify genes that predispose individuals to fibrosing lung disease is an alternative to modeling the illness in animals such as genetically-modified mice.

The recent application of molecular biology to toxicity testing of pharmaceuticals has enabled predictions of safety using in vitro systems and high throughout screening systems as animal alternatives. These screening systems can be automated to provide fast cost-effective and more ethical approaches to toxicity screening.

A high-throughout screening (HTS) system consists of a variety of in vitro assay systems or other such platform technologies (such as yeast-based reporter gene assays, and a variety of receptor-binding and transcription activation assays using established mammillaria cell lines including human cells for identifying endocrine disrupter compounds often integrated with softwares to screen compounds as per the selected assay format. It is commonly used in negative selection of compounds i.e., to screen out the compounds not matching the defined assay parameter. High throughout screening assays normally uses 96-well format plates formats but attempts are made for developing assay formats with higher plate density e.g., 384 and 1536- well formats. These new approaches offer potential for making significant advances over existing screens in speed, high-throughout capability, sensitivity, reproducibility, and reduction in animal usage in a screening and testing program of new chemical entities for treatment of various diseases.

(c) Use of computer simulation: Mathematical and computer models can effectively complement animal experimentation. In fact, the use of computers in biomedicine is increasing as more biological process are understood and converted into mathematical forms. In order for a biological phenomena to be adapted to a computer model, the basic processes must be expressed in a mathematical formula. Once a formula is developed then an enormous number of variables can be introduced and swiftly processed.

Computer models enable scientists to predict the way in which an organism may respond to varying levels of exposure to a certain chemical, and to design better experiments to actually determine the response in a living animal. For the most part, data in computer-based predictive systems are derived from the results of animal studies. Thus, the predictability is only as good as the animal data on which it is based.

Developments in computer modeling and systems for the prediction of biological activity and toxicity have already revolutionized the process of drug discovery and development, by eliminating the need to use animals for pre-screening of almost limitless numbers of potential drug candidates. For example, the protease inhibitors that are a key part of AIDS triple therapy were developed very quickly through the use of powerful computers which analysed the viral enzyme and predicted the kinds of chemicals that would block its action. This approach is now being used to target other stages of the AIDS virus cycle.

Application of computer models screening tools and commercial databases available for use by pharmaceutical industry ranges form toxicity predictions (quantitative structure function relationship) and ADME predictions, comparison and analysis of protein/DNA sequences, identification and prioritization of drug targets, high throughput screening, drug-drug interaction, convert gene sequence into 3-D protein structure and vice versa. Computer simulations and multi-media presentations are often used to replace the use of animals in education. In order to achieve this, a huge amount of data, usually from in vitro studies, has to be collected and integrated into the program.

Computers also permit better data management. Computer-assisted data banks allow greater accessibility of experimental results to scientists in laboratories all over the world, thus reducing the need for test duplication. More recently, new technologies powered by computers, such as nuclear magnetic resonance spectroscopy, make it possible to observe biological phenomena that previously could only be inferred.

USE OF ANIMALS FOR RESEARCH AND TESTING

Описание: animals

Introduction

There are 4 reasons why animals are used in research:

1. The principles of anatomy and physiology are true for humans and animals, especially mammals. Once scientists learned that animals were similar to humans, in physiology and anatomy, it became preferable to use animals rather than humans for preliminary research.

2. Certain strains or breeds of animals get the same diseases or conditions as humans. “Animal Models” are frequently critical to understanding a disease and developing appropriate treatments.

3. Research means introducing one variable and observing the results of that one item. With animals we can control their environment (temperature, humidity, etc.), and shield them from disease or conditions not related to the research (control their health). Although human and animals get the disease they may be the subject of a research investigation, the different life styles or living conditions make them poor subjects until preliminary research under controlled conditions has been done.

4. We can use scientifically-valid numbers of animals. Data from one animal or human is not research; it is a case study. To scientifically test a hypothesis, an adequate number of subjects must be used to statistically test the results of the research.

Some individuals claim that we should use human or animals that have a disease to study that disease. Certainly, epidemiological studies (tracking the occurrence of a disease or condition) have provided many important insights into the cause of a disease or a condition, especially when an environmental aspect is responsible. As noted earlier, the study of a disease is severely hindered or not possible when the research subjects have been/are exposed to a variety of environmental factors.

It is important to note that, according to the American Medical Association, humans are the most frequently used animal in research. However, research studies conducted on humans follow preliminary studies conducted in animals. These animal studies make human studies a reasonable risk. The animal studies are not a guarantee of success, but they do tell us that the human research has a reasonable probability of success.

How are Animals Used in Research ?

CSIRO uses animals in research in a number of ways, as described below :

(a) Ecological Studies

The use of animals in ecological studies is usually limited to observation or capture-markrelease of free-living animals to identify what species and how many animals are present in a particular habitat. In capture-mark-release, reptiles and small mammals are caught in pit fall traps or other small enclosure traps. The information required for each animal is noted— species, sex, breeding status, and so on. The animal is marked to identify that it has been caught and counted, and then released at the point of capture. A small number of animals are retained as voucher specimens or blood sampled for DNA testing.

(b) Laboratory Studies

Laboratory animals such as rats, rabbits and guinea pigs are used by CSIRO for studies related to farm animals. Others are used in studies relating to human health such as studies that explore the role of diet and nutrition in the prevention of diseases, like cancer and cardiovascular disease.

Many of these animals are painlessly killed to provide biological materials such as blood and tissue for test-tube (in vitro) studies that focus on the cellular and molecular level rather than on the whole animal.

Rabbits are often used to produce antibodies to help diagnose disease in other animals, and to create new vaccines to protect animals against disease. These rabbits rarely show signs of sickness or discomfort when they are used in this way.

CSIRO continues to investigate new methods using gene technology to produce antibodies that could replace the use of laboratory animals.

(c) Livestock Health

The study of infectious disease often requires the experimental infection of animals. In order to control a new disease (and new ones arise regularly), it is necessary to know what systems of the body are involved, what other species may be susceptible, and how the disease spreads.

To examine the effectiveness of vaccines or other treatments that may be produced, an animal trial is eventually required. Animal use, however, has been reduced over recent decades, as laboratory techniques are now able to do much of the work before animal research is necessary. Test-tube techniques or computer simulations are often useful, but cannot provide all the information needed to develop and trial an effective vaccine. Comparing the on-farm outcomes in vaccinated and unvaccinated animals, such as cattle and sheep, is the only way to provide crucial information.

Livestock Productivity

Animal-based research projects that are aimed at improving livestock productivity often involve large number of animals. These animals receive no or few experimental treatments other than the husbandry practices that farm animals would usually receive. For example, in a project to select sheep resistant to internal parasites, the faeces it over 6,000 sheep were collected and examined for worm eggs and larvae.

Principles Guiding Animal Research

CSIRO considers the welfare of animals, whether domestic or native, to be one of its most important missions, and much of our science is directed at improving it. We care about the health, well-being and welfare of animals, and we are sensitive to public and industry expectations that they be treated humanely, kindly and without undue stress. We aim to meet the highest standards of animal care in all we do, and to remain sensitive to changing public values and attitudes on this issue.

CSIRO, in consultation with its Animal Ethics Committees (AECs), follows the ‘3Rs’ of animal welfare. They are:

Replacement of animal research with other research techniques that do not repair animals wherever possible.

Reduction of the number of animals used in any research.

Refinement of animal research to ensure the optimum quality of life for those animals involved in research.

Animal disease studies may cause pain or discomfort for some animals. Prompt steps are taken to relieve this, but if seriously affected, animals are humanely put down as soon as possible.

The overall aim of animal health research is to prevent Australia’s animals experiencing pain and suffering from disease.

Regulation of Animals Experiments

By law, every Australian research organisation using animals in experiments must establish an Animal Ethics Committee (AEC). Each AEC is required to include members with specific backgrounds–veterinary science, animal welfare, animal experimentation, and no experience in animal experimentation. At least two members must be independent from the organisation undertaking the research

Any research proposal must be approved by the AEC before it can proceed. Scientists must be able to show that the research is beneficial, and that it cannot be undertaken without using animals. The Committee also ensures that excessive animal use does not occur, distress to the animal is prevented or minimised throughout the experiment, and that the quality of life of the animal is acceptable.

CSIRO’s Animal Ethics Committee meet several times a year to consider new research proposals, and monitor ongoing experiments.

Scientists at CSIRO also follow the “Australian Model Code of Practice for the Care and Use of Animals for Scientific Purposes”. The code was produced jointly by the Standing Committee on Agriculture and Resource Management (SCARM),  ogether with the National Health and Medical Research Council (NHMRC), Australian Research Council (ARC) CSIRO, and the Australian Vice-Chancellors’ Committee (AVCC). These bodies are all signatories to the Code.

The Code of Practice is intended as a guide for people responsible for the welfare and husbandry of a range of animals, as well as AEC members. The Code is kept under review to take account of advances in the understanding of animal physiology and behaviour, changes in animal husbandry and their relationships to the welfare of animals.

The Code covers topics such as the acquisition and care of animals in breeding and holding areas, wildlife studies, and the care and use of livestock of scientific and teaching activities. For example, it specifies that animal accommodation should be designed and managed to meet species-specific needs, and that animals must receive appropriate uncontaminated and nutritionally-adequate food.

Initiatives of the CSIRO’s Animal Ethics Committees

CSIRO’s Animal Ethics Committees have actively encouraged:

• Involvement of a biometrician in development of all protocols to ensure that the minimum number of individual animals are used to acquire meaningful data.

• Minimising the impact of studies on individual animals by provision of environmental enrichments such as toys and novel methods of feeding, and by defining humane endpoints for each study.

• The use of alternatives to animal research, such as growing tissue cells in a nutrient medium to produce cellular proteins that are used in disease defence, instead of using more mice.

• Creation of Standard Operating Procedures for scientific staff, that advice the best way of performing certain common procedures involving animals, in the interests of animal welfare and therefore good quality science.

• Publication of Standard Operating Procedures for scientific staff, that advise the best way of performing procedures on animals, in the interests of their welfare and good quality science.

• The inclusion of a section on Wildlife Studies in the Australian code of practice for the care and use of animals for scientific purposes, 6th edition 1997.

• Modification of pitfall traps to provide protection of trapped animals from heat, dehydration, flooding and predation by other animals during the period that they are in the traps.

• Research into the use of analgesics in animals being used in studies of disease

processes.

Описание: animal clon

ANIMAL CLONING

While the technique of cloning has changed dramatically over the years, the basic principle remains the same. Take a blood clotting factor protein we would like to clone in a cow as an example. Essentially, the gene for the factor would be linked to a promoter specific for a milk protein. This promoter is responsible for ensuring that the gene is only expressed in the milk of the animal. Many copies of this promoter-gene combo are then introduced into a cow’s egg, which is allowed to develop in a surrogate animal. A technique called ‘Pronuclear injection’ is used to do this and involves injecting the DNA directly into fertilized eggs using a very fine glass needle (transfection).

However, pronuclear injection is very unreliable. This is due to DNA uptake and integration into the genome of the egg cell being a very rare event, typically resulting in 1 to 5 transgenic animals out of every 100 being born. Dolly the sheep, the first animal cloned by pronuclear injection, was the result of one success out of 277 eggs. Another Biotech company, PPL Therapeutics, took several years just to produce a flock of 600 transgenic sheep. available, pharming would not be a feasible option. This problem has been solved by a new technique called ‘nuclear transfer’, which solves the low percentage of transgenic offspring by selecting for eggs that have cloned genes integrated into the egg’s genome before it is implanted into the surrogate. Essentially, cells are transfected as before, with the addition of a gene that makes the egg resistant to an antibiotic if it is expressed properly. This allows for the selection of only those cells that properly express the antibiotic resistance gene, and in conjunction the gene of interest. The nucleus of these cells are then removed and transferred to an egg to allow fusion with the nucleus. Since all the eggs contain the transgene, virtually 100% of the offspring will be transgenic animals.

ETHICS AND ANIMAL CLONING

Should this be allowed ethically? To look at this, here are several possible criteria—unnaturalness, diversity, fundamental concerns, animal welfare and commodification.

Is it Unnatural ?

Many people say that cloning farm animals would be unnatural. Whereas in the plant kingdom cloning is a fairly common phenomenon, there are few animal examples and none in mammals or humans. Should we then respect this biological distinction, or should we celebrate our human capacity to override such limitations? It is hard to argue in an absolute sense that anything is unnatural, when so little remains around us that we might justifiably call natural, and nature itself is in constant motion. Yet many believe some technological inventions are now going too far to remain in tune with what we perceive “natural” to mean, despite how much we have intervened in nature to date. Is cloning animals a point to draw a line?

Would it Narrow Genetic Diversity too far ?

This brings us to the question of diversity. One of the fundamental rules of selective breeding is that you must maintain a high enough level of genetic variation. The more you narrow down the genetic “pool” to a limited number of lines of, say, animals for meat or milk production, the more you run risks of problems from in-breeding. If that is the case with breeding, how much more is it true of cloning, where genetic replicas are involved. This means there are pragmatic limits to how useful cloning would be, but beneath the pragmatics there lies a deeper ethical concern. Does this reflect something fundamental about the nature of things?

Is there a Fundamental Ethical Concern ?

This is something for which Christian theology provides some insights. For the Christian, the world around us is God’s creation, and one of its most characteristic features is variety. The biblical writers make repeated allusions to it, painting striking pictures of a creation whose very diversity is a cause of praise to its creator. It could be argued that to produce replica humans or animals on demand would be to go against something basic and God-given about the very nature of higher forms of life. Where God evolves a system of boundless possibilities which works by diversification, is it typically human to select out certain functions we think are the best, and replicate them? Deliberate cloning aims at predictability, replication, in order to exercise control, whose centralised, even totalitarian approach contrasts with God’s command to animals and humans to “be fruitful and multiply”. In the limit this argument would mean that cloning would be absolutely wrong, no matter what it was being used for. This intuition runs deep in many people. But there are also questions of scale and intention to consider. Justifiable Uses of Cloning Cloning animals might be acceptable in the limited context of research or where the main intention was not the clone as such but growing an animal of a known genetic composition, where natural methods would not work. Roslin’s work to produce ‘Poly’ the transgenic-cloned sheep would be such a case, where the intention is not primarily to clone, but to find more precise ways of animal genetic engineering. Indeed, producing medically useful proteins in sheep’s milk is one of the least contentious genetic modifications in animals, since the intervention in the animal is very small for a considerable human benefit. Careful scrutiny would be needed, to see that it was only applied to genetic manipulations that would be ethically acceptable, but that is a question we already faced before cloning.

Animal Welfare Concerns

We also need to be sure about the animal welfare aspects even of limited cloning. Questions have been raised about the number of failed pregnancies and unusually large progeny which appear to be resulting from Roslin’s nuclear transfer experiments to date. While the suffering is not so great as to put a stop to this work, it is clearly necessary to understand the causes and establish whether the problems can be prevented, before the methods could be allowed for more general use. If after a reasonable time there seemed little prospect doing so, however, one would doubt whether it was ethical to go any further. This also points to the serious possibility that any attempt at human cloning could be extremely dangerous for both the clone and mother, and thus medically unethical, irrespective of wider ethical concerns.

 

Описание: _babies

HUMAN CLONING

To understand the cloning debate (and to distinguish cloning from genetic engineering, which many opponents fail to do) we need to understand:

(a) Reproductive cloning: creating a new organism from a single cell of an adult. The genes (but not the far less-important mitochondrial DNA) of the offspring are identical to the parent.

(b) Therapeutic cloning: creating embryos to supply embryonic stem cells as a source of spare parts to treat disease.

(c) Genetic engineering: changing genes in cells that will be transmitted to all offspring, was recently used to make pigs that many supply compatible transplant organs for people.

WHY CLONING HUMANS IS ETHICALLY UNACCEPTABLE?

Dr. Wilmut, the scientist involved, and his colleagues at Roslin have made it quite clear that they think that to clone humans would be unethical. The Human Fertilisation and embryology/ Authority agrees with the general public impression that to clone human being would be ethically unacceptable as a matter of principle. I and most people in the Church of Scotland would certainly agree that on principle, to replicate any human technologically is something which goes against the basic dignity of the uniqueness of each human being in God’s sight. Christians would see this as a violation of the uniqueness of a human life, which God has given to each of us and to no one else. In what sense do we mean this ?

Some say that the existence of “identical” twins means that we should have no ethical difficulty over cloning, or that to object to cloning implies that twins are abnormal. This argument does not hold. Biologically, identical human twins are not the norm, but the unusual manner of their creation does not make them any less human. We recognize that each is a uniquely valuable individual. There are two fundamental between cloning and twinning, however.

Twinning is a random, unpredictable event, involving the duplicating of a genetic composition which has never existed before and which at that point is unknown. Cloning would choose the genetic composition of some existing person and make another individual with the same genes. It is an intentional, controlled action to produce a specific known end. In terms of ethics, choosing to clone from a known individual, and the unpredictable creation in the womb of twins of unknown genetic nature belong to categories as different as accidental death is to murder.

The mere existence of “identical” twins cannot be cited to justify the practice of cloning.

CONTROLLING SOMEONE ELSE’S GENETIC MAKEUP

Thus it is not the genetic identity that is the crucial point but the human act of control, and it is this element of control which provides the fundamental ethical case against human cloning.

The biblical picture of humanity implies that we are far more than just our genes, or even our genes plus environmental influences, there is also our spiritual dimension, made in God’s image, constituting a holistic notion of being, in which the relational element is as important as the individual. To be a person is to be in relationship. Hence, it is vital that the relational implications of technology are considered alongside the ontological. It is against this picture that most Christians would see it ethically unacceptable to clone human beings as a matter of principle. In so far as genes are a fundamental part of our make up, to choose to replicate the genetic part of human make up technologically is a violation of a vital aspect of the basic dignity and uniqueness of each human. By definition, to clone is to exercise unprecedented control over the genetic dimension of another individual. This is quite different from the control parents exert in bringing up our children. Whatever the parents do or do not do, it is inevitable that they have a profound effect on their children. No one exerts the level of control involved in preselecting a child’s entire genetic make up except by a very deliberate act. Moreover, a child can reject any aspect of its upbringing, but it could never reject the genes that were chosen for it. Such control by one human over another is incompatible with the ethical notion of human freedom, in the sense of that each individual’s genetic identity should be inherently unpredictable and unplanned.

INSTRUMENTALITY

Cloning raises a number of concerns arising from its consequences, of which instrumentality and risk are of special importance. To replicate any human being technologically is a fundamentally instrumental act towards two unique individuals – the one from whom the clone is taken and the clone itself. In nearly all the speculative ideas for cloning a human would use the clone as a means towards someone else’s end. They would be created as clones for the primary benefit not of the individuals themselves but of some third party. This would be the case for cloning a dying child or parent to help those bereaved cope with the loss, or cloning an infant with a predisposition to leukaemia, as a source of bone marrow which would suffer less tissue rejection problems. These violate a basic ethical principle, that of create another human being other than primarily for their own sake. There is an important distinction in Christian theology, which admits an instrumental role for animals, to a limited degree, but prohibits it in humans. To clone a child with leukaemia to provide compatible bone marrow would treat the cloned sibling to that extent as means to an end, for the benefit of a third party, rather than for their own sake, and without their consent. Dorothy Werth cited the controversial US case where this was done through normal reproduction, but I would question whether the fact that it worked is justification enough. Again, it is rightly said that we have mixed motives for why we want children, but that does not justify treating a child as a means to an end.

INFERTILITY – AN EXCEPTION TO INSTRUMENTALITY

An exception to this objection would be the idea of producing a child from an infertile couple by cloning one of them. But this raises other problems. Instead of being the unique genetic product of both parents, the child is a copy of one of them. For many Christians this would be a denial of a basic relational aspect of reproduction, just as in the case of surrogacy. For an infertile couple to have a child by cloning one of them would not normally be thought of as an instrumental act, and might at first sight sound like a compassionate option to offer to childless couples. As observed above, however, there could be serious ethical problems, notwithstanding the anguish which childlessness brings to many couples. It would not be the biological child of both parents in the normal sense. For many this might be seen as taking the technological harnessing of the desire for a child one step too far, a means which is not justified by the end. The tendency is becoming to demand parenthood as my right, as though it were some moral absolute. We are losing the Christian understanding of children are a gift, not a right which we can presume that God or life should give us on demand.

PSYCHOLOGICAL EFFECT – IDENTITY AND RELATIONSHIP

There are a number of reasons why human cloning might be ruled out for the psychological dangers involved. No one knows what would be the effects on human identity and relationships of creating someone who is the twin of their father or mother, but born in a different generation and environment. Would the clone feel that he or she was just a copy of someone else who’s already existed and not really themselves? Am I really someone else but put into a different womb? What will be my relationship to the one I was cloned from? No one can predict with any degree of assurance what the response would be. Presumably they would vary from person to person. I suggest there sufficient dangers for applying the precautionary principle should apply.

In other words, even though one could not be sure how many people would suffer in this way, it would be wrong knowingly to inflict that risk on someone whose interests are being put first?

PHYSICAL RISK

Dolly took 277 attempts and nearly 30 failed pregnancies to get one success. To repeat the same thing on humans would be giving both the mother and the potential foetus an unacceptably high risk of damage. The basic science of fusing the cytoplasm and nucleus and reactivating the cell is very poorly understood. How many abnormal babies would have to be produced to get one right? There are sufficient unknowns about physical problems in pregnancy with cloned sheep and cattle to suggest that human cloning experiments would violate normal medical practice.

Roslin researchers have said that there is no experiment that could be done to prove the safety of human cloning without causing serious risk to humans in the process. Then there are also unknown factors of ageing. How old is Dolly? Is she her age since her birth, or her age since birth plus the age of the tissue from which she was taken? No one knows what the effect of nuclear transfer on ageing processes.

SOCIAL RISK

Finally, human cloning would bring grave risks of abuses to human dignity and exploitation by unscrupulous people. We have already seen examples of people offering cloning services for large sums of money, when there is currently no reasonable prospect of delivery, and apparently regardless of the risks involved or, in the case of Richard Seed, the rule of law. It is also an open door for abuse, in the way that another individual, a group in society or even the state could exert undue control over an individual. If anyone ever did unfortunately clone humans, it is important to counter the suggestion from science fiction that they would be subhuman androids with human bodies but no souls. More seriously, some papers from an Islamic perspective seem to imply that if reproduction is by human artifice, it lacks the spiritual element. Some Christians think the same. I do not, however, see any grounds that a cloned child would be any less human than another child. Why would God fail to make the child fully “in His image” just because the manner of conception? There would need to be considerable safeguards to avoid the risk of stigmatization. It would be foolish to imagine that abuses could not occur.

The author maintains that "absent a religious or culturally normative understanding of human nature and given the availability of germ-line genetic engineering, there is a plurality of possibilities for refashioning our nature." While elimination of deadly diseases is one aspect of genetic engineering's moral significance, another is "the possibility that numerous possible future alternatives may be chosen, fracturing mankind into numerous different species of humans." Given that there are no content-full norms for guidance, the author concludes that the decision to undergo germ-line gene transfer research would rest with the individual. 

Potential Applications of Human Cloning

In most cultures there would be huge ethical problems in making genetic copies of human beings—so-called reproductive cloning. Currently, this is ethically nacceptable because of the high incidence of congenital abnormalities in offspring derived from cloning by nuclear transfer. If there were no such problems—if cloned children would be as healthy as those produced naturally—one can concoct scenarios for which reproductive cloning might be ethically acceptable. The classic example is a couple whose baby dies within a day or two of birth due to an accident that also makes the mother incapable of reproducing due to damage to ovaries. One could theoretically take cells from the dead baby and clone them using a donated oocyte, which could then be transferred to the uterus (which is still functional) of the woman. The donor cells from the dead baby could also be frozen for later use, so timing would not be a problem.

Other (very improbable) scenarios could be envisioned that would make reproductive cloning ethically acceptable for most people. In any case, this technology for reproductive cloning of persons would likely work with a similar success rate as occurs in other species (extremely low, as of 2003). It is certainly possible that a century or more in the future this mode of reproduction will be used to some extent, and persons from that era may well consider our current collective thinking quaint. Since chromosomal genetic identity never results in phenotypic identity, one never recreates a person or animal, and even if phenotypic identity were possible, such individuals would still be individuals. Identical twins and triplets provide some guidance on potential problems. Such individuals usually lead fairly normal lives, and they are considerably more identical than manufactured clones will ever be.

Therapeutic Cloning

A second kind of cloning, therapeutic cloning, is intended to produce tissue and organ replacement parts. There are millions of people worldwide who suffer from debilitating diseases such as diabetes, heart disease, and cirrhosis of the liver. Similarly, millions suffer from accidents that severely damage tissues and organs, including burns, spinal cord damage, and crushed kidneys. In many of these cases, tissue or organ transplants will prolong life and greatly increase quality of life. There are two major problems with this approach: (1) There is a critical shortage of such tissues and organs, and (2) there is usually immunological incompatibility of donor and recipient, which requires immunosuppressive therapy that is debilitating and greatly increases the incidence of cancer. A solution to this unfortunate situation is to use nuclei of somatic cells of the subject to make immunologically compatible tissues for replacement parts. This approach is not yet available for practical use, but likely will be developed in one form or another in the near future. What is envisioned is to take cells (e.g., from skin) of the person who needs the replacement tissue, and fuse them with donated oocytes from which original chromosomes are removed to form early embryos. Instead of transferring these to the uterus to form a fetus, they would be induced to develop into various tissues in vitro. No fetus would be formed, so there would be no brain, heart, leg, or face, but rather tissues that make up body parts. Quite a bit is known about how to induce the embryonic cells to make muscle, skin, or other tissues, but there is still much to be learned.

This approach likely cannot be used to produce a heart or a kidney, at least in the foreseeable future, but producing heart-muscle cells, nerve cells, pancreatic tissue, liver tissue, or skin does seem feasible. Liver, for example, has a remarkable regenerative capability, so only a small bit of liver may be needed—such as liver stem cells, which might regenerate a whole organ after transplantation. Producing pancreatic tissue to alleviate diabetes would likely be considerably simpler, while producing nerve cells to repair spinal cord damage would likely be more difcult. It is possible that some tissues can be generated from adult stem cells, circumventing the need for cloning via embryos. However, the embryonic approach has several theoretical advantages—it is the way tissues develop naturally, for example—and it has some practical advantages as well. Furthermore, research into  in vitro differentiation of tissue, much of which can be done in animal models with or without the cloning steps, will likely produce information that can eventually be used outside of the context of cloning to accomplish the numerous therapeutic objectives.

Characteristics of Cloned Animals and Related Ethical Consequences

If all goes well, a genetic copy of the animal being cloned is produced, but, again, one clone can vary considerably in phenotype from the donor for numerous traits. Unfortunately, natural reproduction does not go well in every case, and such problems are greatly exacerbated with cloning. In a 2002 summary of all available information on animals cloned from somatic cells (38 studies resulting in 335subjects in 5 species), Jose B. Cibelli and colleagues found that 77 percent of the resulting animals were normal, while 23 percent were not. The normal subjects, though mostly adults, had not yet lived out their normal life spans, so additional problems (over and above those due to normal aging) could yet develop. Cloning from somatic cells has not resulted in monsters, but, in most cases, reasonably normal individuals.

However, 23 percent abnormalities, mostly neonatal death, is completely unacceptable ethically for producing children, and for most scientists working in this area that ends the ethical debate on human reproductive cloning. In the Cibelli survey it was noted that many of the animals produced represented the initial, or at least early, studies on cloning in respective laboratories, and that the incidence of abnormalities likely would decrease with more experience and improved techniques. This is already being borne out in the scientific literature, but it likely will be many years before the incidence of problems with somatic-cell cloning will decrease to acceptable levels for reproductive cloning of people. However, this ethical crutch will also likely disappear with time.

A complex ethical question is where to set the boundaries on acceptable levels of abnormalities. Interestingly, a 2002 study by Michèle Hansen and colleagues that looked at children produced via  in vitro fertilization showed that congenital abnormalities were approximately double the 4 percent seen with natural reproduction. Most of these abnormalities were not extremely serious and could be circumvented or repaired. Nevertheless, the abnormalities were doubled, and some were serious. Thus, this ethical problem is already with us.

The question boils down to the right of people to reproduce given an increased risk of an abnormal child. Of course, these questions arise outside of the context of assisted reproductive technology, such as the increased risk of a child with Down’s syndrome when older women reproduce. Modern science can minimize such suffering (e.g., by genotyping embryos before transfer back to the uterus, and eliminating those that will result in severely abnormal individuals). Another reality is that, in one sense or another, nearly all persons are abnormal. For example, essentially all humans have lethal or severely debilitating recessive alleles in their genetic makeup, which, if matched with another such allele in a gamete of a mate, will result in death of the conceptus or resulting child.

A frequent abnormality that occurs with cloning by nuclear transfer via embryonic or somatic donor cells is fetal overgrowth. It is not unusual for offspring to be 30 or 40 percent larger than normal at birth. In some studies, up to 30 percent of offspring have this condition, known as  largeoffspring syndrome, and some animals cloned from the same donor are large, some are normal, and some are small— which elegantly illustrates that identical chromosomal identity does not equal identical phenotype. Large-offspring syndrome is not a genetic trait, in that this problem is not transmitted to the next generation when the cloned animals reproduce naturally. Also, Michael Wilson and colleagues showed in 1995 that these excessively large neonates develop into only slightly larger adults. The scientific consensus is that large-offpsring syndrome can be summarized as a genetically normal fetus in an epigenetically abnormal placenta. That is, the placenta from cloned pregnancies is often abnormal, resulting in secondary problems in the fetus that largely correct themselves after birth. Unfortunately, with routine husbandry, the newborns often die because of being debilitated from gestating in an abnormal placenta. Fortunately, with a few days of intensive care starting at birth, such offspring survive reasonably well and develop normally, as shown by Frank B. Garry and colleagues in 1995. As with human babies, animal offspring derived from  in vitro fertilization or long-term  in vitro culture of embryos have a much higher incidence of abnormalities than with normal reproduction, but a lower incidence than with cloning (see Kelley Tamashiro and colleagues). Clearly, some (but not all) in vitro manipulations, particularly when the  in vitro period exceeds several days, lead to increased problems in resulting offspring. Thus, there is a baseline of problems with natural reproduction, which increases with the amount of in vitro manipulation (and reaches a higher level with somatic-cell cloning). It is likely that these problems will decrease or be circumvented with improved techniques, and also that the basic information obtained will be useful in decreasing birth defects and neonatal problems that occur with natural reproduction.

There are some special problems with a small percentage of pregnancies from somatic-cell cloning that are not just an increase in incidence of naturally occurring problems. In some cases, the immune system appears to be severely compromised, and there can be major problems with the heart, blood vessels, and kidneys that are extremely rare with normal reproduction. Furthermore, there is an unusual amount of embryonic death and fetal absorption or abortion with cloned pregnancies—over 80 percent embryonic and fetal attrition is not unusual (compared with around 30 percent with normal reproduction). Thus, the incidence of problem conceptuses is very high, and most of these die in early pregnancy. This is still another reason that, as practiced at the beginning of the twenty-first century, reproductive cloning should not be done with human embryos.

A final point is that cloning via nuclei from somatic cells is very inefficient, currently on the order of 2 percent success per oocyte. This is due to the multiplicative attrition (or success) of the various steps. For example, if there is 90 percent successful fusion of donor cell and oocyte, with 50 percent dividing into embryos suitable for transfer to recipients, 30 percent embryonic survival until pregnancy can be diagnosed, 20 percent of diagnosed pregnancies developing to term, and 85 percent surviving the neonatal period, the result is an overall success rate of around 2 percent. These are typical current values, and are one reason why the costs of cloning are so high. While success rates are improving, it will likely be some years until overall success even approaches 10 percent. For human reproductive cloning, dozens of women would need to be involved as donors of oocytes and recipients of embryos to produce even one baby—assuming the procedures worked as well as they do with animal models, which is unlikely. This illustrates another ethical issue, in that undue use of scarce and expensive medical resources would be required for clonal human reproduction.

Cloning: Its Nature and Capabilities

The type of cloning described above is called somatic cell nuclear transfer (SCNT) because it transfers the nucleus of a somatic or body cell into an egg from which the nucleus has been removed. A different type of cloning is achieved through fission or cutting of an early embryo. Through this method it may be possible to make identical human twins or triplets from one embryo. These genetically identical embryos could then be stored for further tries at conception, thus saving a woman from undergoing repeated ovulation during fertility treatment. Here, however, the concentration will be on cloning through SCNT. Also, this entry treats only cloning for reproductive purposes, not what has come to be called research or therapeutic cloning. In the latter, the same process occurs but is not intended to lead to the birth of a child. Rather it is oriented, for example, to the study of the process of development or to the producing of stem cells that might be useful in therapies for Parkinson’s, diabetes, and other diseases. How close are we to being able to produce a human being through cloning? As of the beginning of 2003, to researchers’ knowledge there have been no human beings produced through cloning. Clonaid, a company founded by a religious sect called the Raelians, has claimed to have produced five cloned babies. However, no DNA or other evidence has so far been provided to substantiate this. In November 2001, Advanced Cell Technology, a small biotech company in Worcester, Massachusetts, said it had succeeded in producing a human embryo through cloning. Scientists extracted human eggs from seven volunteer women and replaced the nuclei of these eggs with cells from an adult donor, some skin cells and some cumulus cells (the cells surrounding a maturing egg). While none of the eggs that used the skin began the cell division process, three of the ьeight eggs that were re-nucleated with cumulus cells began dividing. One developed to the two-cell stage, one to the four-cell stage, and the third to the six-cell stage, at which point it too died.

One can also judge something of the potential for human cloning from the progress of animal cloning. In just the past two decades a number of higher animals have been produced through cloning, including cows, sheep, goats, mice, pigs, rabbits, and a cat called CC for carbon copy or copy cat. Cloned animals themselves have produced offspring of their own in the natural way. Dolly had six seemingly normal lambs. Several generations of mice have also been produced through SCNT. Clones have been derived not only from udder cells, but also from cells from embryos and fetuses, and from mice tails and cumulus cells. owever, these experiments have been neither efficient nor safe. In the case of Dolly, 277 eggs were used to produce only one lamb. In March 1996, the Roslin Institute also produced two lambs from mature embryo cells, Megan and Morag. However, they were only two out of five who were born and survived in a project that used over 200 embryos. Alan Coleman, research director of PPL Therapeutics, the company that produced Dolly, reported having cloned five female pigs who were genetically modified to lack a gene that makes pig organs incompatible with the human immune system. However, here the success rate was again quite low. Scientists implanted 300 embryos, producing twenty-eight sows that gave birth to seven live piglets, only four of which survived. In another project involving rabbits, 371 eggs were implanted, using twenty-seven rabbits as foster mothers, but only six rabbits were born and only five of these survived to the state of weaning. CC, the cat mentioned above, was one of eighty-seven embryos implanted in eight surrogate mother cats, and was the only one of two resulting pregnancies that survived.

Cloned animals also have shown various abnormalities. In one study all twelve cloned mice died between one and two years of age. Six of the cloned mice had pneumonia, fourhad serious liver damage, and one had leukemia and lung cancer. On February 14, 2003, Dolly died. She was euthanized because she suffered from a lung disease that the owners feared would spread. At age five, Dolly had also been diagnosed with arthritis. Some suggest that this may be due to the fact that she was cloned from the cell of an already aged adult sheep. However, in late 2001 Advanced Cell Technology claimed to have cloned thirty cattle from skin cells, twenty-four of which were alive and healthy between one and four years later. Some say that the high failure rate and the prevalence of serious abnormalities in animals means that cloning humans is probably not possible. Others believe that with time the efficiency and safety of animal cloning will improve and then it may be possible to clone human beings as well.

Uses of Reproductive Cloning

What uses might there be, or what reasons might someone have, for producing a human being through cloning? What follows is a survey of a number of possible uses of this procedure, some of which are obviously more problematic than others. The ethical issues that have been or might be raised regarding the possible uses of reproductive cloning will then be discussed. One of the probable primary uses, if cloning does become a reality, is for the treatment of fertility problems. For example, if the male or husband is sterile, or does not produce sperm, DNA from one of his cells could be inserted into a de-nucleated egg from the female or wife who would also bear the child. Both would then be contributing to the make up and birth of the child. Many have pointed out that there is a strong desire among people who want a child to have one that is biologically related to them. These parents also may wish to avoid the confusion that can result from the use of donor eggs or sperm. If the woman is infertile, another woman’s egg could be used along with the DNA of the infertile woman or her husband or partner. Cloning might also be used to avoid genetic diseases.

Another possible use would be in the fertilization of a woman who wants to have children to whom she is related biologically, but who does not have a partner and does not wish to use donor sperm. The woman might be one who is single and who has not found a suitable partner, or who is divorced and still wants to have children. A cell from her body could be used. In this case the child would be a clone of the woman herself. Or in the case of a lesbian couple, a cell from the body of the other partner could be used. In this case both would have contributed to the make up of the child.

Someone might want to produce a child who is a clone of a much-loved spouse or child who has died. As noted below, while this would not bring back the loved one or duplicate them exactly, there would be some similarities and thus in a way the ability to keep some part of the person alive. One might even want to achieve a certain kind of immortality by cloning oneself. This would be similar in some way to living on through our children and their children.

Cloning could also be used to help ill family members. There have been cases in which parents have conceived a child in the hope that he or she could be a donor match for a sibling who had some serious disorder. A child who was the clone of such a sibling could also be a blood or bone marrow donor for the sibling. Although no one is suggesting that clones would be produced simply as the source of organs, some organ donation might not be objectionable. Finally, cloned human beings could provide us with further information about the relationship between nature and nurture. A disabled person might want to show or see what he would have been like but for the disability, or someone might simply be curious to see how a clone of himself might grow to adulthood.

Ethical Objections and Arguments

Ethics judges or evaluates human choices and actions or policies as being, for example, good or bad, right or wrong, and just or unjust. Ethical or moral judgments (the terms being used synonymously here) require reasons that justify them. Many people have raised various ethical objections regarding human cloning. The arguments and the reasons given for them are summarized here as well as the responses of critics of the arguments. However, since what is presented is only a summary, it is not possible to give a full analysis of the kind of reasons that they exemplify and why these might or might not be well-grounded in generally-accepted values or in ethical theory.

It should also be noted at the outset that ethical evaluation is independent of social policy and law. Not everything that is morally bad or wrong ought to be illegal. It takes a separate set of reasons to conclude that because some instances of human cloning might be morally wrong that they should then also be illegal. Nevertheless many of our policies and laws do have ethical bases. First the ethical arguments will be treated and then finally some social policy issues related to them. Some suggestions regarding the relationship between these two domains will also be provided.

 

References:

A. Main:

1. The Cambridge Textbook of Bioethics / Edited by Peter A. Singer and A. M. Viens. - Cambridge University Press, The Edinburgh Building, Cambridge CB2 8RU, UK, 2008. – 526p.

2. Encyclopedia of Bioethics, Third Edition in 5 vols / Stephen G. Post, Editor in Chief. - Macmillan Reference USA, 2004. – 3300p.

 

B - Additional:

1. Bioethics and Biosafety/ M K Sateesh. - I K International Pvt Ltd, 2008. - 820 p

2. Bioethics and public health law / David Orentlicher, Mary Anne Bobinski, Mark A. Hall. -Aspen Publishers, 15 февр. 2008 – 687p.

3. Professionalism in Health Care: A Primer for Career Success / Sherry Makely, Vanessa J. Austin, Quay Kester. - Pearson, 2012 – 238p.