Tuesday, February 26, 2008

Outline

Introduction

Part I: A Brief description of the Early Life Issues

  1. When does a human being begin?
  2. What are New Reproductive Technologies?
  3. Stem Cells
  4. Cloning

5. A Stem Cell Timeline

Part II: The ethics of the Early Life Issues

1. What is “Ethics?”

2. The New Subjectivism – Some Examples

3. Misdirections and Evasions: Common Media Euphemisms

4. The Case for a Pro-Life View of Embryo Research

  1. The Case for a Pro-Life View of New Reproductive Technologies
  2. Other Ethical Problems with New Reproductive Technologies

Part III: The Canadian Situation

  1. Time Line
  2. The Assisted Human Reproduction Act

Part IV: The International Situation

  1. Britain
  2. Europe
  3. The US
  4. Central and South America
  5. Africa and the Middle East
  6. Australia, New Zealand and Asia

Part V: Resources

  1. Source documents and Recommended Reading
  2. Online information

Appendices

  1. A Glossary of Philosphical Terms
  2. A Glossary of Biotechnology Terms

Introduction:

This book will provide a reference for pro-life activists, students, legislators, teachers, clergy and interested individuals about the range of activities and procedures that make up what we have referred to generally as the Early Life Issues, that is those surrounding artificial procreation; the creation and manipulation of human beings at the embryonic stage of life. The subject is immense and is one of the fastest growing scientific fields of our day. Effectively to defend the fullness of the pro-life position, familiarity with the basic concepts is necessary and not difficult.

The term, new reproductive technologies (NRT) refers to all methods of artificial procreation either sexually by the joining of ova and sperm or asexually by various methods that have become known collectively as “cloning”.

Outside the immediate realm of NRT but closely related to them, recent developments have given us the intricate world of embryonic research, experimental cloning and genetic manipulation. In the pure research areas, medical and other experimentation is performed on living human embryos, usually those left over (often called “spare”) after various artificial fertilization techniques and stored cryogenically; or so-called “fresh embryos”: those created either sexually or by cloning for the purpose of experimentation.

In the second category is included all kinds of manipulation of human life at the embryonic stage for eugenic or other purposes, germ-line alteration, and selection/diagnosis techniques.

The two areas of study together make up the Early Life Issues (ELI). The second area, that of pure research, has created an entire new field in the biotechnology industry which is lobbying heavily for the use of live human beings at the embryonic stage of life. Often the research proposed is purely experimental and does not pertain to fertility. In some cases, the research does not even aim at finding cures for diseases and represents the end-result of the aims of the eugenics movement to manipulate and “improve” the human species.

When studying the Early Life Issues, a firm grasp on the basics of the pro-life philosophy is essential. Without understanding the twin premises – that a human being in the fullness of his moral status exists at the earliest moments of the single-cell stage; and that human beings may not be killed, experimented upon, donated or in any way treated as chattel – the pro-life position on ELI cannot be grasped or defended effectively. This book, therefore, will outline the philosophical problems presented by those who advocate for creating and using embryonic human beings for research and provide the means for making effective counter arguments.

The text is divided into five parts:

Part I gives an explanation and description of the various activities that form the subject of the Early Life Issues, including artificial procreation techniques and purely experimental research.

Part II, on the ethics of the Early Life Issues, examines the nature of the ethics problem of our times. It offers a brief description of the philosophical movements that have shaped the current situation and offers a short course in making the pro-life case against embryo experimentation and new reproductive technologies in general.


Part III will give an overview of the current situation in Canada, a brief history of the pro-life effort surrounding the current legislation.

Part IV gives a brief overview of the situation around the world.

Part V gives a list of resources where further information and/or indepth studies can be found both online and in print.

Appendices include:

  • glossaries of relevant biotechnological and philosophical terms,
  • the full text of the Vatican’s document “Donum Vitae” that presents much of the argument made in this text,
  • Campaign Life Coalition’s document on Canada’s reproductive technologies legislation, “A Final Critique of C-13”.

Part I: A brief description of the Early Life Issues.

1. When does a human being begin?[1]

Fertilization: (also known as conception) is the fusion of gametes[2] to form a new organism of the same species. In animals, the process involves a sperm fusing with an oocyte, which begins the development of the embryonic child. The spermatozoon and the oocyte[3] meet and interact in the fallopian tube. After finding the oocyte, the sperm binds to the zona pellucida, a protein membrane surrounding an oocyte.

Fusion between the sperm and oocyte plasma membranes follows, allowing the entry of the sperm into the oocyte. At this point the embryo comes into existence and is genetically distinct from either of the original sex cells.[4]

Once the single sperm cell has fused to the outer membrane of the oocyte, the membrane changes, preventing fusion with other sperm.

With the fusion of chromosomes from oocyte and sperm, a new, genetically distinct human being exists that is alive and separate from, though dependent upon the mother.

This process leads to the formation of a diploid[5] single-cell zygote[6]. The zygote is the earliest stage of human development in which the complete genotype, or genetic system of the human individual is in place .

The process of cell division continues and when the zygote has formed a ball of 12 to 32 cells it is referred to as a "morula." More division follows until the embryo has formed a small central cavity, called the blastocele. The embryo now consists of an outer cell mass, or trophoblast, that forms a hollow ball, containing an inner cell mass. This stage is called the blastocyst.

The trophoblast will later form the placenta and the cells of the inner mass will develop to form all the tissues of the child’s body. Both inner and outer cells of the blastocyst are called blastomeres.[7]

The blastocyst continues to travel down the fallopian tube until it reaches the uterus and implants in the endometrium. The human blastocyst comprises 70-125 cells.

A Genetically Distinct, Alive and Separate Human Being

The usual way most life forms reproduce, whether plants or animals, is sexually, that is, by the joining of male and female gametes from two members of the same species. In human beings, the sperm and oocyte are ready to join when they contain the requisite numbers and organization of genes in their nuclei: 23 each. When the sperm penetrates the oocyte, the two sets of chromosomes are joined and a new human being comes into existence, one with a unique and irreproducible genetic combination of 46 chromosomes.

After this genetic system is in place, the new individual begins to grow using the DNA[8] blueprint that gives its body directions on how to develop. The zygote does not change its nature and become a human being at some point of its existence, it and the adult are one and the same being.

From the first moment of fertilization,[9] therefore, a complete, living, growing, genetically distinct member of the human species comes into existence that is no “part” of the mother but is physically dependent upon her for nutrition and a protective environment.

The DNA “blueprint,” or genotype, of the new individual is complete from the one-cell stage. That a complete and living human being is fully in existence from the single-cell stage is confirmed by over a hundred and fifty years of findings in the field of human embryology and is the basis of the pro-life assertions in the Early Life Issues as well as abortion. No scientific finding in the field of human embryology has disproved this assertion.

From the moment of conception, the single-cell zygote also fulfills all criteria for independent life. Scientific textbooks give five basic characteristics or criteria for living things:

1. Living things are highly organized.

2. All living things have an ability to acquire materials and energy.

3. All living things have an ability to respond to their environment.

4. All living things have an ability to reproduce.

5. All living things have an ability to adapt.

The human embryo fulfills all these scientific requirements for life. It is highly organized and complex; scientists are only beginning to understand the intricacies of single-cell embryos. It processes nutrients from its environment even before it has attached to the uterine wall. It has the ability to respond to and adapt to its environment, and has the ability to reproduce with cell division. It is also intrinsically endowed with the potential, upon reproductive maturity, to reproduce other members of the species.

Supporting References

“A new individual is created when the elements of a potent sperm merge with those of a fertile oocyte, or egg.”

Encyclopedia Britannica, “Pregnancy,” page 968, 15th Edition, Chicago 1974

“Everyone begins life as a single cell.”

Dr. David Galton, a professor of the Wolfson Institute of Preventive Medicine, St. Bartholomew's Hospital Medical School, London, “Eugenics: the Future of Human Life in the 21st. Century”

“I oppose abortion. I do so, first, because I accept what is biologically manifest – that human life commences at the time of conception – and second, because I believe it is wrong to take innocent human life under any circumstances. My position is scientific, pragmatic, and humanitarian…Conception confers life and makes that life one of a kind.”

Dr. Landrum Shettles, discoverer of male and female producing sperm and a pioneer in the field of in vitro fertilization.

"The exact moment of the beginning of personhood and of the human body is at the moment of conception."

Dr. McCarthy de Mere, medical doctor and law professor, University of Tennessee:

"I am no more prepared to say that these early stages represent an incomplete human being than I would be to say that the child prior to the drmatic effects of puberty . . .is not a human being."

Dr. Alfred Bongiovanni, University of Pennsylavania School of Medicine.

"By all the criteria of modern molecular biology, life is present from the moment of conception."

Dr. Hymie Gordon, Chairman, Dept. of Genetics at the Mayo Clinic:

“It is the penetration of the oocyte by a spermatozoa and the resulting mingling of the nuclear material each brings to the union that constitutes the culmination process of fertilization and marks the initiation of the life of an individual.”

Moore, Keith L., The Developing Human: Clinically Oriented Embryology, p. 12, W.B. Saunders Co,. Philadelphia, 1974.

“…The merger is complete within twelve hours, at which time the egg – which may have ‘waited’ as many as forty years for this moment – is fertilized and becomes known technically as the ‘zygote’ containing the full set of forty-six chromosomes required to create human life. Conception has occurred. The genotype – the inherited characteristics of a unique human being – is established in the conception process and will remain in force for the entire life of that individual. No other event in the biological life is so decisive as this one; no other set of circumstances can ecen remontely rival tenotype in ‘making you what you are.’ Conception confers life and makes you one of a kind.”

Dr. Landrum Shettles, M.D., , David Rorvik, Rites of Life: The Scientific Evidence forLife Before Birth, p. 36, Zondervan Publishing House, Grand Rapids Michigan, 1983.

Senate Judiciary Committee S-158, 97th Congress, 1st Session 1981

In April, 1981, a US Senate Subcommittee convened to examine the question, “When does life begin?” The official Senate report summarized, “there is overwhelming agreement on this point in countless medical, biological, and scientific writings.”

Dr. Micheline M. Matthews-Roth of Harvard Medical School, supported by over 20 references from human embryology and other medical textbooks, testified:

In biology and in medicine, it is an accepted fact that the life of any individual organism reproducing by sexual reproduction begins at conception, the time when the egg cell from the female and the sperm cell from the male join to form a single new cell, the zygote; this zygote is the starting cell of the new system.

Most textbooks of embryology have chapters describing the history of embryology and the experiments done to show that multicellular organisms develop from a single cell, the zygote. Because these kinds of experiments in embryological development have been repeated so many different times on so many different species, and have always led to the same result…that organisms reproducing by sexual reproduction always arise from a single cell, and that they are always of the same biological species as their parents…this fact is universally accepted and taught at all levels of biological education. It is the continuous repetition, duplication and confirmation of experimental results that proves that the fact is indeed true…

It is scientifically correct to say that an individual life begins at conception…Our laws, one function of which his to help preserve the lives of our people, should be based on accurate scientific data.



[1] The question at the head of this section is phrased slightly differently from the usual, “when does human life begin?” In the current debate, the pertinent question is not one of biology, which is settled, but of competing philosophies. Many are convinced that a human being, the biological entity that is a genetic member of the human species, exists from the single-cell stage, but will continue to insist that, though human, it has no natural rights to legal protection. The distinctions commonly made between a “human life,” a “human person,” and a “human being” will be more fully explored in the section on ethics below.

[2] Gametes: mature male or female sex cells.

[3] Oocyte: female gametocyte or germ cell involved in reproduction.

[4] The term “fertilised egg” found commonly in the media, is an error and betrays either ignorance of embryology or a bias in favour of allowing abortion or other interventions in human development like embryonic stem cell research. There is no such thing as a human “egg” and a “fertilised oocyte” is an embryo. Mammals, for the most part, do not have eggs. This topic is further explored in Part II 2.

[5] In diploid organisms (most plants and animals), each chromosome is inherited from a different parent. Haploid cells contain exactly half of a species typical full set of genetic material: in the case of humans, 23 chromosomes each. When they are ready to fuse, oocyte and sperm are haploid.

[6] A zygote is a single-cell embryo, the result of fertilization. That is, two haploid cells, an oocyte from a female and a sperm cell from a male, merge into a single diploid cell called the zygote. Twins and multiple births can be monozygotic (identical) or dizygotic (fraternal), meaning they arise from one or two separate fertilization events.

[7] The inner blastomeres are what is usually referred to in the media as “embryonic stem cells” sought by researchers. These “pluripotent” cells have the ability to form all the tissues of the human body. The removal of the inner blastomeres for research usually causes the death of the embryonic person.

[8] DNA: Deoxyribonucleic acid. A nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and most viruses).

[9] Fertilization: properly understood to be a process beginning with the penetration of the oocyte by the sperm and ending with the appearance of two fused pronuclei that together contain the 46 chromosomes of human DNA, as a single-cell zygote.

Part I: A brief description of the Early Life Issues

2. What are New Reproductive Technologies?

New Reproductive Technologies (NRT) refer to any artificial intervention employed to obtain a living human being at any stage of development for “reproductive” purposes. That is, any method of making a human being in the embryonic stage of life by any means other than sexual intercourse.

Cloning is included in these because a human being is created and is fully in existence from the first moment of the proper ordering of the genetic material that makes up the human being at the earliest stage of life whether that ordering has been brought about by the combination of oocytes and sperm or by any other non-sexual method. A cloned human being is fully a human being at the earliest stage of his life.

Because of the size and complexity of the subject, however, cloning is treated in a separate section in this text.

A variety of techniques

Currently, techniques in use in fertility treatment facilities include:

· fertility enhancement drugs

· artificial insemination (AI)

· in vitro fertilization (IVF)

· intracytoplasmic sperm injection (ICSI)

· pre-implantation genetic diagnosis (PGD)

  • zygote intrafallopian transfer (ZIFT)
  • gamete intrafallopian transfer (GIFT)
  • assisted hatching
  • twinning or blastomere separation
  • surrogacy
  • embryo “adoption”
  • gamete donation

Recent experimental advances include the creation of embryos from sperm or oocytes only; the creation of embryos using combinations of human and animal DNA; the development of artificial wombs; and the creation of genetically matched embryos to be used as tissue donors for siblings or other relatives with serious illnesses.

Fertility Enhancement Drugs

Synthetic hormonal agents that stimulate ovarian follicle[1] development are often tried first in cases where infertility is the result of anovulation. These drugs fall into two categories: clomiphene citrate (commonly called Clomid or Serophene), given in pill form; and the injectible Gonadotropins (sold as Humegon, Pergonal, Repronex, Fertinex, Follistim and Gonal-F.)

Clomiphene citrate works by "tricking" the system into thinking there is insufficient estrogen and indirectly stimulating the ovaries. Gonadotropins contain follicle stimulating hormone (FSH) and directly stimulate the ovaries.

Fertility drugs are often associated with the increased incidence of multiple births. In one famous case in the UK, a woman using them found that she was pregnant with seven children at once. In such cases, it is common for doctors to select and abort one or more of the children, in a procedure referred to as “selective reduction” or “foetal reduction”.

Artificial Insemination (AI)

AI is typically recommended as the first stop for the treatment of infertility due to:

  • mild to moderate male factor infertility
  • "unexplained" infertility
  • cervical mucus insufficiency
  • hostile cervical mucus
  • various structural abnormalities in the woman

AI involves injecting a sample of specially treated sperm from the male partner, or a third party donor, into the female partner's reproductive tract. The sperm sample is obtained through masturbation. If the sperm is obtained from a donor, the resulting child will be the biological offspring of the woman and the donor, not the woman and her husband or chosen partner.

Different types of AI include:

  • intracervical (in the cervical canal)
  • intrauterine (in the uterine cavity)
  • intrafollicular (in the ovarian follicle)
  • intratubal (in the fallopian tubes).

When AI and/or fertility drugs fail, couples who can afford it often move to the more dangerous and invasive and expensive in vitro fertilization techniques.

In vitro Fertilization (IVF)

The term ‘in vitro’ is simply Latin for “in glass” and refers to the method of creating a new human being at the earliest embryonic stage of life by physically mixing together human sperm and oocytes in a laboratory. The resulting embryos are implanted into the uterus of the patient or a surrogate and brought to term. Those embryos not selected for implantation can be stored cryogenically, donated for scientific research or destroyed.

The practice was developed in the 1970’s by Drs. Patrick Steptoe and Robert Edwards and was successfully employed for the first time in England with the birth, on July 25, 1978, of Louise Joy Brown who was hailed in the press as “the world’s first test-tube baby.” In fact, Louise Brown can more accurately be described as merely the first IVF baby to have been successfully brought to term.

The success rate for pregnancy with IVF is estimated by the best commercial clinics at about 15-25%, depending upon various factors such as the age of the woman. This means that it is common to have patients make several attempts, each costing thousands of dollars. In Canada, IVF treatments are not often covered by public health insurance plans and are laregly the province of private, for-profit clinics.

In normal IVF procedures, more embryos are created in each round of treatment than can be implanted at once and the so-called “spare” embryos are stored frozen in liquid nitrogen and can be thawed out and implanted for subsequent attempts.

The creation of multiple embryos enables several attempts with different embryos created in the same batch. It also enables the selection of embryos for various desired genetic traits and to “screen” for various potential medical problems such as Down’s syndrome or possible predispositions to heart disease or cancer. Preimplantation genetic diagnosis (PGD - see note below) by various methods is now normally offered as part of the IVF procedures in most clinics. Sex selection of embryos, though in some countries technically illegal, is also routinely offered as part of the program.

The IVF Procedure:

The procedure usually begins on the third day of menstruation and starts with a regimen hormonal drugs to stimulate the ovaries to begin producing oocytes at an accelerated rate. Typically approximately ten days of injections are required.

A procedure is then performed to retrieve the mature oocytes using an ultrasound-guided needle piercing the vaginal wall to reach the ovaries. The retrieval procedure takes about 20 minutes and is usually done under conscious sedation or general anaesthesia.

The oocytes are then examined for imperfections and those most likely to be fertilized are selected and mixed in a culture medim for about 18 hours. By that time fertilization should have taken place and the embryo would show two pronuclei[2].

They are left in the medium and allowed to develop to the 6-8 cell stage (about 48 hours.) In some cases the embryos are placed into an extended culture system until the blastocyst stage.

Intracytoplasmic sperm injection (ICSI)

A procedure in which a single sperm is selected and injected directly into a mature oocyte using a micropipette. This procedure is most commonly used to overcome male infertility problems. After the procedure, the oocyte is placed into cell culture and checked for signs of fertilization and division.

ICSI is one of the artificial procreation techniques most frequently cited in studies on the incidence of birth defects in NRT’s. Problems associated with ICSI include reduced testosterone levels in ICSI-conceived boys. Studies have shown a relationship between ICSI and infertility, cystic fibrosis, cancer, and developmental delays in children conceived by the method.

In March 2002, two major studies were published that found that babies conceived as a result of ICSI were twice as likely to suffer severe birth defects. The authors of one of the studies, published in the New England Journal of Medicine, concluded,

“As compared with natural conception, the odds ratio for a major birth defect by one year of age, after adjustment for maternal age and parity, the sex of the infant, and correlation between siblings, was 2.0 with intracytoplasmic sperm injection, and 2.0 with in vitro fertilization…

“Infants conceived with use of intracytoplasmic sperm injection or in vitro fertilization have twice as high a risk of a major birth defect as naturally conceived infants.”

Preimplantation Genetic Diagnosis (PGD)

Many IVF facilities offer preimplantation genetic diagnosis, a procedure that is under development but is meant to detect possible abnormalities. It also detects possible genetic problems or genetic predispositions to future illnesses like cancer or heart disease. Those embryos not selected are normally either destroyed or donated for research.

In the procedure, a single blastomere is removed from the embryo after the trophoblast has formed. This is examined for genetic abnormalities. The removal of the blastomere from the days-old embryo can in some cases cause damage to the embryo.

Most IVF facilities include PGD as a normal service associated with fertility treatments and many hospitals will include “genetic counsellors” who may advise patients, based on a diagnosis of a genetic abnormality or possible inherited traits, to abort a child.

Gamete intrafallopian transfer (GIFT)

GIFT is used in instances where the fertility problem relates to sperm dysfunction, and where the couple has infertility from an unknown cause. Some patients may prefer the procedure to IVF for what are considered “ethical reasons”, since the fertilization takes place inside the body.

Fertility drugs are administered to the woman to stimulate ovarian follicles. When the follicles are mature, the woman is injected with Human Chorionic Gonadotropin (HCG). The oocytes are harvested approximately 36 hours later, mixed with sperm and the resulting zygote is placed in the woman's fallopian tubes using a laparoscope[3].

Zygote intrafallopian transfer (ZIFT)

ZIFT is used in cases where infertility is caused by a blockage in the fallopian tubes. Oocytes are retrieved from the ovaries and fertilized in the lab. The resulting zygote is then placed into the fallopian tube by the use of laparoscopy. The procedure is a spin-off of the gamete intrafallopian transfer (GIFT) procedure.

Assisted hatching

In the first stages of development, the embryo is surrounded by a strong membrane (made of glycoproteins) called the zona pellucida. Expansion of the embryo as it develops and grows, together with the production of enzymes causes the zona pellucida to open, releasing the embryo. This is called “hatching.” The embryonic cells then come in contact with the lining of the uterus, allowing implantation.

In some cases, the zona does not break down properly and a procedure, assisted hatching, is performed. Performed under a microscope assisted hatching involves holding an embryo with a pipette, and, using a fine needle filled with a hatching solution, a hole is drilled in the zona. The embryos are then transferred to the woman’s uterus. Because there is now a hole in the zona, the embryo is more exposed to the environment and at risk of bacterial infection.

Blastomere separation or “Twinning”

Propagation of embryos by “twinning,” or the separation of a blastomere from an early-stage embryo is a form of asexual reproduction and therefore is classed as cloning.

This procedure is common in animal husbandry and has been used in veterinary medicine for some years. The removal of blastomeres from a very early stage embryo does not always result in the death of the embryo but the risk of damage in any micromanipulation is high.

In blastomere separation a zygote created in vitro is allowed to divide until it forms a mass of about four cells. The outer membrane is removed and it is placed in a solution that causes the blastomeres to separate. Each blastomere is placed in culture where it forms an embryo containing the same genetic makeup as the original embryo, an identical monozygotic twin.

The cells in the inner cell mass of the blastocyst are also totipotent and can be induced upon removing them from the embryo to begin dividing as separate embryos. There are two methods of artificial twinning in use. In one, the most common, blastomeres are removed from the embryo and induced to begin division as separate embryos. In the other the entire embryo, including trophoblast, is split and the two parts induced to form two separate embryos.

Unlike the more difficult methods of cloning such as somatic cell nuclear transfer (SCNT), embryos formed by blastomere separation and blastocyst splitting include both the nuclear DNA and the mitochondrial DNA outside the nucleus of the original zygote. Both kinds of “twinning” are advertised by IVF centers as a means of “embryo multiplication” - which could not only reproduce new embryos for infertility but also for pure research purposes only.

Surrogacy

A surrogate mother is also called a “gestational carrier.” Surrogacy is an arrangement whereby a woman agrees, either for monetary consideration or not, to become pregnant for the purpose of gestating and giving birth to a child for others to raise. She may be the child's genetic mother or she may be implanted with someone else's embryo (called gestational surrogacy).

Embryo adoption

IVF typically results in more embryos than can be carried to term by the clients. Unused embryos, often refered to in the press as “spare”, are often stored cryogenically, sometimes indefinitely. In some cases, the extra embryos are given, or sometimes sold, to other couples or women for implantation.

Legal cases are starting to become common in cases of embryo adoption and surrogacy over the “ownership” of embryos.

Pro-life ethicists are divided on the subject with some saying that once the embryo is created, adoption gives the best possible chance of life. Others argue that the implantation procedure is itself illicit and that such embryos ought to be allowed to die naturally, according to the same ethical criteria as individuals dependent upon life support machines.

Gamete donation

Donation of oocytes or sperm has become a mainstay of the IVF industry. Most NRT facilities keep a stock of gametes from donors to use in cases where infertility is caused by the clients’ own biological insufficiency.

To donate sperm a man must usually be screened medically to meet specific requirements regarding age and medical history. A man generally donates sperm at a clinic by way of masturbation. Most establishments at which sperm is donated stock pornography to assist the donor in reaching orgasm.

Donated gametes have had an enormous impact on family law. In countries where IVF is common, laws are starting accept other categories of parenthood, especially in custody cases. A child conceived through donated gametes can have both “genetic” and “social” parents. A child conceived in this way and implanted in a surrogate mother can, in law if not in biological reality, have a genetic and a “social” father, a genetic, gestational or surrogate mother and a social mother. Theoretically a child thus could have 5 parents.

Other concerns with gamete donation surround privacy laws. In Canada, when legislation was being considered, some MP’s brought up the issue of donated gametes and the problem of assuring that a child knows his parentage. Sperm is normally donated anonymously, raising concerns of increasing the risk that rare recessive disease causing genes will become common in the population. Concerns were also voiced of unwitting consanguinity in marriage for the child concieved by donated sperm. One man in a posting on a website called the DonorSiblingRegistry.com claimed to have fathered at least 650 children via sperm donation.

This danger prompted Sweden, Norway, the Netherlands, Britain, Switzerland, Australia and New Zealand to disallow anonymous sperm donation. Canada and the US have no such limitation.



[1] Ovarian follicles are the roughly spherical aggregations of cells found in the ovary. containing a single oocyte. These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte.

[2] Pronucleus is the haploid nucleus of a sperm or oocyte after fertilisation but before fusion of the nuclei.

[3] Laproscopy is also called minimally invasive surgery (MIS), band aid surgery, keyhole surgery, or pinhole surgery. It is a surgical technique in which operations are performed through small incisions (usually 0.5 - 1.5 cm) as compared to larger incisions needed in traditional surgical procedures. It involves the use of a laparoscope, a telescopic rod and lens system that is usually connected to a video camera.

Part I: A brief description of the Early Life Issues

3. Stem Cells

Stem cells are found in all multicellular organisms and are produced by the human body from the earliest stages of its prenatal development. They combine the ability to reproduce indefinitely through mitotic[1] cell division and to differentiate[2] into particular types of tissue. The existence of stem cells has been known since the 1960’s, when they were discovered by a pair of Canadian scientists, Ernest A. McCulloch and James E. Till.

These undifferentiated cells have been found to have varying degrees of plasticity[3]. Stem cells are present in the human body throughout the person’s lifespan and, together with progenitor cells[4], act to repair damaged tissue. So-called “adult” stem cells are those produced in the body throughout the individual’s post-natal lifespan. They are abundantly produced by the bone marrow but are increasingly being discovered in other tissue sources.

There currently exist many therapeutic applications of adult stem cells. Treatments exist for some forms of cancer that involve screening stem cells from the patient’s blood and re-inserting them into the body. Such treatments avoid the problem of tissue rejection and have led to research into replacing entire organs from the patient’s own cells.

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 is often referred to as regenerative or reparative medicine.

What are Stem Cells? [5]

Stem cells are undifferentiated, or unspecialised cells that have the ability both to renew themselves by cell division for long periods and, under certain physiologic or experimental conditions, can be induced to become cells of a particular type of tissue such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas.

Two broad categories of stem cells are known: those derived from human beings at the embryonic stage of life, usually called “embryonic stem cells” in the media, and those derived postnatally, often called “adult stem cells.” Scientists discovered ways to obtain or derive stem cells from early mouse embryos more than 20 years ago. In 1998 a method was discovered to isolate stem cells from living human embryos and grow the cells in the laboratory. These are called human embryonic stem cells, usually[6] taken from embryos created in fertility clinics through in vitro fertilization and donated for research.

Factors Common to all Stem Cells

One of the fundamental properties of any type of 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.

All 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.

Human Embryonic Stem Cells [7]

Embryonic stem cells are usually derived from a four or five days old embryo. The embryo at this stage is a ball of cells called the blastocyst. The blastocyst includes three structures: the outer ball, called the trophoblast, that will later form the placenta and supporting structures for the child after implantation; the blastocoel, which is the hollow cavity inside the blastocyst; and the inner cell mass, which is a group of approximately 30 pluripotent cells called blastomeres that will develop into all the tissues and structures of the child’s body.

Human embryonic stem cells are isolated by removing the inner cell mass from the embryo and transferring it into a plastic laboratory culture dish that contains a nutrient broth known as culture medium. The original embryo dies when the inner cell mass is removed.

The cells then divide and spread over the surface of the dish. The inner surface of the culture dish is typically coated with mouse embryonic skin cells called a feeder layer that give the inner cell mass cells a sticky surface to which they can attach. The feeder cells convey nutrients into the culture medium.

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.

Embryonic stem cells are pluripotent, meaning they are able to differentiate into all of the more than 220 cell types in the adult body. A pluripotent embryonic stem cell can form any of the three germ layers of the early term embryo: endoderm (that will develop the tissues of the interior stomach lining, gastrointestinal tract, lungs); the mesoderm (muscle, bone, blood, urogenital tissues); or ectoderm (epidermal tissues and nervous system).

The pluripotent stem cells derived from blastomeres cannot develop into a fetal or adult animal because they lack the potential to contribute to extraembryonic tissue, such as the placenta.

Totipotent (literally meaning “having all powers”) cells can develop as separate embryos. The zygote is considered totipotent because it will form both the foetal structures and the extraembryonic supporting structures. Totipotent stem cells can be derived from embryos that have not yet formed the trophoblast and can be induced to start dividing and developing as distinct embryos. This technique is called “blastomere separation” and is a form of cloning. It will be covered more fully in the section on cloning below.

The removal of one or more blastomeres from an embryo does not always cause the embryo’s death. This is often done as part of the process of pre-implantation genetic diagnosis in IVF.

Adult Stem Cells [8]

An adult stem cell is an undifferentiated cell found among differentiated cells in a tissue or organ, that can renew itself, and 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 blastomeres of the inner cell mass of the blastocyst), the origin of adult stem cells in mature tissues is unknown.

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.

Researchers are finding sources of adult stem cells in many more tissues than was once thought possible. This finding has led scientists to ask whether adult stem cells could be used for transplants. 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, many researchers believe that these cells may become the basis of therapies for many serious common diseases and injuries.

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 discovered two regions of the brain that contained self-replicating cells which become nerve cells. By the 1990s scientists agreed that the adult brain contains stem cells able to generate the brain's three major cell types—astrocytes and oligodendrocytes, which are non-neuronal cells, and neurons, or nerve cells.

Since then the list of discoveries surrounding adult stem cell origins and their ability to form a wide variety of tissue types has grown almost daily. While embryonic stem cell research has yet to produce any actual therapeutic results, adult stem cells are becoming widely used in the treatment of numerous diseases and injuries and continue to yield promising experimental results related to many serious diseases.

Recent experiments have shown that certain adult stem cell types are pluripotent. 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.

Umbilical Cord Stem Cells [9]

Umbilical cords have traditionally been discarded as a by-product of the birth process. In recent years, however, the blood found in the umbilical cord has been found to be a rich source of multipotent stem cells, some of which have been found to have a plasticity approaching that of embryonic stem cells. Cord blood stem cells have yeilded therapeutic applications similar to those using bone marrow stem cells and peripheral blood stem cells. Private clinics are starting to be found around the world where clients can store umbilical cord blood as a preparation for possible future illness or accident.

Umbilical cord blood stem cell transplants are less prone to rejection than transplants from bone marrow cells. Because umbilical cord blood lacks well-developed immune cells, there is less chance that the recipient’s body will attack the transplanted cells.

Peripheral Blood Stem Cell Transplants

A method of replacing blood-forming cells destroyed by cancer treatment. Stem cells found in the circulating blood, similar to those in the bone marrow, are screened, typically from the patient’s own blood before treatment and replaced afterwards. This helps the bone marrow recover and continue producing healthy blood cells. Transplantation may be autologous (an individual's own blood cells saved earlier), allogeneic (blood cells donated by someone else), or syngeneic (blood cells donated by an identical twin).

During the research in the development of stem cell transplant therapies, it was discovered that bone marrow cells infused intravenously could repopulate the bone marrow and produce new blood cells. From this was developed a method of obtaining stem cells from a patient’s blood.

Now, most hematopoeitic stem cell transplantation procedures are performed using stem cells collected from the peripheral blood, rather than from the bone marrow.

Other Uses of Stem Cells

In the section below, a few examples have been included showing recent breakthroughs and therapeutic applications of adult stem cells. These are only a tiny sampling of the hundreds of discoveries in the last ten years. Thus far, no successful application of embryonic stem cells have been found, although researchers continue to lobby heavily for their use in research.

Apart from use in treating diseases and injuries, human stem cells can also be used to test new drugs. New medications can be tested for safety on cells generated from human pluripotent (embryonic) cell lines that have been induced to differentiate into desired tissue types. Cell lines that are not derived from stem cells are already used in this way. Cancer cell lines, for example, are used to screen potential anti-tumor drugs.

Differentiation

Embryonic stem cells will remain undifferentiated as long as they remain isolated. If they are allowed to clump together they form “embryoid bodies” that begin to differentiate spontaneously and form various tissue types such as muscle cells, nerve cells, etc.

In order to obtain particular desired tissue types, scientists will change the chemical composition of the culture medium, alter the surface of the culture dish, or modify the cells by inserting specific genes. These techniques are referred to as “directed differentiation” the manipulation of stem cell culture conditions to induce differentiation into a particular cell type.

Immune System Rejection Problem

Tissue rejection occurs when the immune system of the recipient of a tissue transplant attacks the transplanted organ or tissue. This is because a normal healthy human immune system can distinguish foreign tissues and attempts to destroy them, just as it attempts to destroy infective organisms such as bacteria and viruses.

In conventional transplants with donated organs, immune supressant drugs must be taken by the recipeint indefinitely to suppress the body’s attempt to destroy the implanted organ. In stem cell applications, the immune system problem is especially acute in attempts to use embryonic stem cells, tissue derived from another person, directly in therapeutic applications.

One of the most important advantages of adult stem cell therapies is that the tissue involved comes from the patient’s own body, circumventing immune system rejection problems.

Key questions in Ongoing Research

The NIH website lists a number of important questions about adult stem cells researchers are currently exploring:

  • 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 undifferentiated 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?
  • What are the factors that stimulate stem cell proliferation in the body’s tissues?

Some Recent Therapeutic Applications and Experimental Results with Adult Stem Cells[10]

February 2005 [11]: A research team led by University of Central Florida professor Kiminobu Sugaya has discovered a compound related to DNA that could improve the results of stem cell treatments for Alzheimer’s patients. The research team found that treating bone marrow cells with the compound made adult stem cells more likely to turn into brain cells in experiments with rats.

February 2006 [12]: 48 people diagnosed with the autoimmune condition known as systemic lupus erythematosus (lupus) received an experimental therapy from Chicago’s Northwestern Memorial Hospital, using a stem-cell transplant from their own bone marrow. At the time of the report, thirty-three of the patients treatment remained in complete remission.

November 2006 [13]: Newcastle University researchers Nico Forraz and Colin McGuckin grew ‘mini-livers’ using stem cells obtained from umbilical cord blood. The tissue is capable of being used to test new drugs and, in future years, of providing life-saving treatment to patients in need of liver transplants.

November 2006 [14]: University College London Hospital, St. Bartholomew’s and the London NHS will treat heart attack victims with an injection of adult bone marrow stem cell treatment. Patients suffering a heart attack will undergo regular treatment of an angioplasty to remove blockage to an artery, and then will receive an injection into the artery of stem cells harvested from the bone marrow in their hip, under local anesthetic. The treatment has shown remarkable success in growing heart tissue, in trials in other countries. Doctors hope the technique will lead to repairing damaged heart muscles and preventing further attacks and the development of heart failure.

January 2007 [15]: Researchers in New York have successfully generated new tooth roots and supporting ligaments in pigs, using human adult stem cells taken from extracted wisdom teeth. The regenerated tooth was used to support a crown restoration in miniature pigs, Reuters reported. The tooth exhibited the same functional and strength characteristics of the original tooth.

February 2007 [16]: Dr. Francisco Fernandez-Aviles, Professor of Cardiovascular Medicine and Chief of Cardiology Service at Gregorio Marañón and Dr. Perin, Director of New Interventional Cardiovascular Technology and Director of Stem Cell Center at the Texas Heart Institute at St. Luke’s Hospital, used human adipose (fat) tissue as a source of adult stem cells to regenerate damaged heart muscle. After processing, the stem cells were injected directly into the patient’s heart, targeting areas of damaged but still viable tissue.

“This is the first time we have used adipose-derived stem cells in humans. We had good results in our pre-clinical tests and we are excited about taking this research to the next level,” said Dr. Perin.

April 2007 [17]: A man's vision was restored by a corneal patch grown from his own stem cells by a team at the University of Melbourne's Centre for Eye Research Australia (CERA) and the Bernard O'Brien Institute of Microsurgery (BOBIM).

May 2007 [18]: Researchers at the University of Texas engineered adult stem cells derived from human umbilical cord blood to produce insulin. Published in the June 2007 issue of the medical journal Cell Proliferation, the paper calls it "the first demonstration that human umbilical cord blood-derived stem cells can be engineered" to synthesize insulin. "This discovery tells us that we have the potential to produce insulin from adult stem cells to help people with diabetes," said Dr. Randall J. Urban, senior author of the paper, professor and chair of internal medicine at the University of Texas Medical Branch at Galveston and director of UTMB’s Nelda C.



[1] Mitosis: division of the nucleus of any type of cell, separating the duplicated genome into two sets identical to the parent's. Stem cells replicate by mitosis.

[2] Differentiation: The process by which a cell acquires the characteristics and specialized function of a particular tissue type.

[3] Plasticity : the degree, varying in different types of stem cells, to which a stem cell is able to change into different tissue types.

[4] Progenitor cells are found in the various tissues of the body and can differentiate, but not renew themselves through dividing. Their main role is to replace cells lost by normal attrition.

[5] The information in this section is mostly taken from the website of the US National Institutes of Health, the US federal health research agency. http://stemcells.nih.gov/info/basics/basics1.asp

[6] Embryonic stem cells can also be isolated from cloned embryos. More information on so-called “therapeutic cloning” is included in the section on cloning.

[9] Information in this section has been taken from the website of the University of Utah, Genetic Science Learning Center http://gslc.genetics.utah.edu/units/stemcells/sctoday/

[10] The following examples have been taken from the archives of LifeSiteNews.com. Since the late 1990’s, LifeSiteNews.com has been recording countless instances of theraputic uses and experimental breakthroughs of adult stem cells, many of which were not reported or were underreported in the mainstream media. Vastly more information than can be recorded in this document is available at http://www.lifesite.net/ . Type the key words “adult stem cells” into the site’s search engine.

[18] http://www.lifesite.net/ldn/2007/may/07052809.html