Expert Advice on Stem Cells (for Beginners)...

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1 Expert Advice on Stem Cells (for Beginners)... Thanks to

2 Contents Why are Stem Cells Important?... 3 Adult vs. Embryonic Stem Cells... 4 Stem Cell Controversy... 5 Religion and Adult Stem Cell Research... 7 Reprogramming Adult Stem Cells... 9 How Alcohol Affects Stem Cells Building a Windpipe from Stem Cells Restoring Eyesight After Chemical Burns: A Case Study Bone Marrow Stem Cells and Diabetes.. 16 Stem Cells to Treat Blindness Therapeutic Cloning Bone Marrow Stem Cell Harvest Cancer and Stem Cells Stem Cells for Stroke Victims Improving Memory With Stem Cells Stem Cell Treatments for Joint Injuries.. 29 Stem Cells and Fat Distribution Restoration of Paralysis, can Stem Cells Help? Stem Cells to Revive Rare Animals A Rare Side Effects of Stem Cell Therapy: A Case Study Stem Cell and Cybrid Controversy... 37

3 Why are Stem Cells Important? To list the ways in which stem cells are important is a broad task because stem cells use is virtually limitless. Stem cells have the potential to treat an enormous range of diseases and conditions that plague millions of people around the world. Their ability to treat so many diseases rests on their unique properties of: Self-renewal: stem cells can renew themselves almost indefinitely. This is also known as proliferation. Differentiation: stem cells have the special ability to change into cells with specialised characteristics and functions. Unspecialised: stem cells themselves are largely unspecialised cells which then give rise to specialised cells. Human Development One reason that stem cells are important is because we develop from stem cells. An understanding of stem cells can teach us about early human development. Diseases such as cancer are thought to result from abnormal cell proliferation and differentiation. This means that an understanding of where things go 'wrong' in stem cell division leading to cancer may help us find ways to prevent cancer or develop more effective drug treatments. Birth Defects Stem cell research has the potential to teach us more about how birth defects occur and how these can be prevented or possibly reversed. An understanding of the regulation and chemical triggers of stem cell proliferation and differentiation are key to addressing birth defects. Cell Therapies Probably the most important use for stem cells is in cell therapies. A cell therapy is a treatment that replaces dysfunctional or diseased tissues with stem cells. At present, stem cells are already used in cell therapies for treatment of some cancer types but this use is still only in small numbers of patients. The number of organs available for transplant is scarce in comparison with those requiring one. Many people suffer and others will die whilst awaiting a transplant. Stem cells may replace damaged cells and tissues for those who require a transplant. Alzheimer's and Parkinson's diseases as well as those diseases affecting the retina and heart may also be treated using stem cells in the future. Clearly, stem cell use is exciting and holds great promise for treating and perhaps one day curing many diseases. Their importance ranges from an understanding of the principles behind human development to the cell based therapies addressing those aspects that go awry during development and lead to disease.

4 Adult vs. Embryonic Stem Cells Research has been ongoing now for years as scientists have tried to determine whether stem cells from adult tissues have the same capabilities and potential as embryonic stem cells. So: which source holds the advantage? Development Potential Embryonic stem cells have a far greater differentiation potential than adult stem cells simply because embryonic stem cells can develop into almost every type of cell in the human body. Conversely, adult stem cells may only develop into a limited number of cell types, so their potential applications are not as great as embryonic stem cells.. At present, it would appear that embryonic stem cells have the edge as they differentiate more readily than adult stem cells. Is More Better? In the case of stem cells, the answer is yes, assuming that more stem cells still means viable, high quality ones. Embryonic stem cells are capable of almost unlimited division, or proliferation, when placed in a culture whereas adult stem cells do not multiply so readily. Embryonic stem cells can also be grown fairly easily in the laboratory whereas adult stem cells are difficult to grow after isolation from mature adult tissues. Stem cell replacement therapies require large numbers of cells and the current difficulty in growing large numbers of adult cells means that their use for therapy at present is limited. Effect on Recipient's Immune System Adult stem cells hold a distinct advantage in that a patient's own cells are identified, isolated, grown and transplanted back into the patient. The recipient's immune system does not reject the cells because they are compatible with that person's body. With embryonic stem cells, the potential for immune rejection may require strong immune suppressing drugs to combat rejection of the new cells. The patient may be at risk from infectious diseases. A Question of Cell Youth Adult stem cells are more likely to have abnormalities from DNA mutations. The 'youth' of embryonic stem cells means that they are less likely to carry. Ethics Since adult stem cells are derived from adult tissues, with consent from the patient, there is little, if any, ethical dilemma to adult stem cell therapies. Embryonic stem cells, on the other hand, have triggered enormous debate due to the destruction of an embryo following cell extraction. Also, embryo destruction has essentially become entangled in the abortion debate, creating a mass of controversy between religious leaders, politicians and the public.

5 Stem Cell Controversy Mention the word 'foetus' and heated controversy is likely to soon follow. This is particularly the case in the field of embryonic stem cell research. Embryonic stem cells are derived from the foetus and research into the therapeutic properties of these stem cells and have triggered massive debate amongst politicians, religious groups, the general public and lastly, a minority of scientists. Good and Bad of the Stem Cell Debate Opponents of embryonic stem cell research compare the destruction of an embryo to an abortion. They believe that the embryo constitutes life because it has the potential to fully develop into a human being. Those against embryonic stem cell use believe that is it immoral and unethical to destroy one life to save another. By using stem cells and discarding the embryo, it is thought that human life is ultimately de-valued by this act and is paving a slippery slope for further scientific procedures that similarly de-value life. In particular, many religious groups who are adamantly pro-life have condemned embryonic stem cell research and all of its applications. Other arguments against embryonic stem cells cite the fact that adult stem cells are the ones currently being used in therapies and thus, there is no need to even venture into embryonic stem cell territory. Those who support embryonic stem cell research believe that an embryo is not equivalent to human life because it is inside the womb. Supporters also contend that the societal costs of many diseases and conditions, both in monetary and suffering aspects, means that the ethical concerns regarding embryonic stem cell usage are not sufficient to warrant discontinuation of this promising therapy. Another argument for embryonic stem cell research is that the embryos are leftover from in-vitro fertilisation and would otherwise be destroyed, so they should instead be put to greater use. Even further down the line in development is the belief that those embryos from legal abortions, which have already been destroyed, would be better used to advance human health rather than simply discarded. Any Solutions to this Conundrum? Fortunately, there are alternatives but they are far from perfect and they do still require further research before they can be used with an acceptable level of success. Two new embryonic stem cell treatments avoid the foetal destruction by either: Deriving embryonic stem cells without destructing the foetus Obtaining embryonic stem cells without actually creating a foetus In altered nuclear transfer (ANT), an embryo is not created. A derivative of somatic cell nuclear transfer (SCNT), the nucleus of the somatic cell (any body cell other than an egg) is altered, or genetically

6 reprogrammed, prior to being transferred into the egg. The alteration consequence is that the somatic cell DNA still produces stem cells but does not generate an embryo. In blastomere extraction, an embryo is created but not destroyed. This procedure is performed on a twoday old embryo, following the division of the fertilised egg into eight blastomeres or cells. Previously, the technique for harvesting embryonic stem cells used embryos at a later developmental stage, when the embryo is made up of approximately 150 cells. When these cells were harvested, the embryo was destroyed. Embryonic stem cells can instead be extracted from blastomeres, therefore preventing embryo destruction and allowing use of stem cells for research and therapeutic treatment of disease. The other alternative is to strictly use adult stem cells because these are derived from adult tissues. The therapeutic potential is lower, however, because adult stem cells can't differentiate into as many different types of cells as can embryonic stem cells. They are also more likely to have developed genetic abnormalities over time and they don't tend to replicate as efficiently. It is unlikely that a comprehensive solution will be found for the embryonic stem cell debate anytime soon. In the meantime, both national and international policies along with collective public views will likely guide the research and therapy efforts for embryonic stem cells. There is no doubt that stem cells have great potential for treating disease but there unfortunately still remain doubts as to the ethical and moral ramifications of pursuing this potential.

7 Religion and Adult Stem Cell Research Stem cell research holds enormous potential for treating a broad spectrum of diseases but before that potential can even begin to be harnessed, there must be a clear pathway to obtaining the research needed to make stem cell therapies a reality. Since the advent of stem cell research, one barrier to furthering stem cell research has been religion. The destruction of an embryo that occurs when embryonic stem cells are extracted has angered and upset many religious groups, who see it as 'murder' or the destruction of human life. They do, however, tend to support the use of adult stem cells. With adult stem cells, extraction is from adult tissues and does not result in the destruction of an embryo. In this way, religious groups are pushing for a greater focus and research on adult stem cells. However, their efforts are not without opposition from scientists and researchers themselves, mostly due to the different properties of embryonic and adult stem cells. The two stem cell types have numerous benefits and challenges. The Use Of Embryonic Stem Cells In Science Embryonic stem cells have some special properties that really set them apart from adult stem cells. It is these specific properties that have resulted in a greater support from the scientific community. At the same time, the very nature of embryonic stem cells in terms of how they are isolated for research has caused controversy for religious groups, thus pitting embryonic stem cells and adult stem cells against one another. Embryonic stem cells are pluripotent cells, which means that they have a unique ability to differentiate into any of hundreds of cell types in our bodies. Not only that, but embryonic stem cells can more easily be grown in the laboratory in comparison with adult stem cells. In a sense, they are younger and fresher cells that can more readily be coaxed to grow as needed for research and therapeutic value. Religious Arguments Against Embryonic Stem Cell Use It is generally cited in the scientific community that there is no substitute for embryonic stem cells and that adult stem cells simply don't hold the same potential as embryonic stem cells. These scientists also explain that the embryos were discarded ones that would serve a better purpose by being put to use to improve the health and lives of people suffering from devastating diseases such as diabetes and heart disease. Religious groups such as Catholics strongly disagree and support the view that life begins at conception. By this notion, any research on embryos is synonymous with murder. Some of the more liberal religious groups take a somewhat relaxed approach to stem cell research and do support the use of embryonic stem cells. Others may support the use of embryonic stem cells but only when used under very tight, rigid parameters.

8 The Case For Adult Stem Cells Despite the fact that there are arguments for the benefits of embryonic stem cells as well as arguments against the use, virtually everyone can probably agree that in an ideal world, adult stem cells would be equivalent to embryonic stem cells. In this way, researchers and scientists could obtain more funding and forge ahead to use adult stem cells as they attempt to find treatments and cures to some of the most debilitating diseases. Researchers could avoid the controversy and funding issues that occur due to religion and political factors. The reality is still controversial as well because religious groups argue that adult stem cells are just as capable as embryonic stem cells. Recent years have shown increased funding from religious groups to adult stem cell research, with the hopes that greater interest in the use of adult stem cells will prompt reduced use of embryonic stem cells. While there has been a great deal of promising research into adult stem cells, including recent studies that suggested adult stem cells can be reprogrammed into embryonic-like cells, current knowledge still dictates that embryonic stem cells hold far more therapeutic potential. The debate over the use of embryonic stem cells does not appear to be fading anytime soon. As religious groups continue to push for the use of adult stem cells instead of embryonic ones, it may very well be that we find new potential and uses for adult stem cells. Until that time, however, embryonic stem cells continue to be the most promising stem cells but the surrounding ethical controversy may ultimately prevent the full harnessing of embryonic stem cell power.

9 Reprogramming Adult Stem Cells One of the challenges of stem cells research has been to appease the ethical and moral controversies surrounding the use of stem cells. These specific concerns are usually related to embryonic and foetal stem cells because the harvesting of such stem cells does with most techniques, result in the destruction of an embryo. It is not, however, a simple case of simply using adult stem cells because embryonic stem cells have some notable advantages over adult stem cells. Embryonic or Adult Stem Cells? Despite the ethical controversies surrounding embryonic stem cell use, they tend to replicate more rapidly and they also have the ability to differentiate into many more cell types than adult stem cells. Furthermore, because these cells are younger than adult stem cells, they do not usually have the genetic abnormalities that adult stem cells can develop over time. Reprogramming Adult Stem Cells Into Embryonic Stem Cells Several studies have been published from research performed in Japan. In the studies, adult stem cells were essentially rewound and the differentiation process ran backwards, which caused the adult stem cells to revert into an embryonic stem cell like state. The cells were virtually identical to true embryonic stem cells as was the gene expression. The cells were also capable of becoming a fully functioning organism, which is a true test of embryonic stem cells. Previously, a study on mice had stated that it produced embryonic stem cells from adult stem cells. However, while these cells could develop into all tissue types, they could not produce a live animal, which indicated that the cells were really only partially reprogrammed.in a more recent study, however, cells were fully reprogrammed. By turning on the expression of four chemicals in the cells of an adult mouse, these cells were reprogrammed in reverse to an embryonic like state. Ultimately, the cells could not be distinguished from true embryonic stem cells. The greatest challenge will still be to produce these results in human cells. First, however, many other challenges will need to be overcome in studies before success with human cells can become a reality. Challenges Unfortunately, the process itself is not without its challenges. It is a very inefficient process because only a handful of cells out of thousands can thus far be successfully reprogrammed. In addition, these reprogrammed cells can go on to develop abnormalities, which must be resolved before any treatments with the cells can become a reality. Another issue is that the four factors or chemicals used in studies on mice may not be the same factors that allow for reversion in human cells. A retrovirus was originally used to introduce the genes of each factor into the cells but such retroviruses can also activate genes that trigger tumour growth. All of these issues must be resolved before this particular process can become feasible for use on humans. Still, the possibility to obtain the benefits of embryonic stem cells while originally using adult stem cells is exciting because it provides a way to appease the ethical concerns regarding the use of true embryonic stem cells. Until then, the controversy will still remain but continued research can hopefully provide treatments for disease that are acceptable to all members of the public.

10 How Alcohol Affects Stem Cells Alcohol is known to cause many health problems but new research shows it can affect stem cells too. In particular, a recent study suggests alcohol harms stem cells in the developing brains of teenagers. The study looks at binge-drinking, where a great deal of alcohol is consumed over a short period of time, generally with the intention to become drunk. It is a problem particularly prevalent among teenagers in Britain and a number of other countries such as the United States. Examining the Brains of Monkeys Researchers looked at the brains of adolescent monkeys to determine how alcohol affected stem cells. They chose monkeys because human and monkey brains develop in similar ways, making monkeys a more reliable choice for experimentation. A Year of Alcohol Four monkeys were given alcoholic drinks flavoured with citrus for a period of nearly one year. They received the drinks for an hour a day over this time period to mimic the effects of binge-drinking. After two months following the end of nearly a year, the animals were dissected to look at how their brains compared to monkeys that hadn t received any alcohol. Study Criticisms One criticism of the study that should be noted, however, is that the monkeys continued to receive alcohol throughout this period. In reality, a person who is binge-drinking usually does not consume much alcohol throughout the week. Instead, they would have bouts of consuming a lot of alcohol in a short period of time. In teenagers, this behaviour is common on weekends, where a teenager drinks excessively but then abstains during the week. Fewer Stem Cells Researchers found that the monkeys who had been given alcohol over the year had fifty to ninety percent fewer stem cells than the healthy monkeys who did not have any alcohol. The stem cells that were significantly reduced were those in the hippocampus part of the brain. This area of the brain plays a key role in many important functions such as memory and spatial skills. Essentially, the alcohol kills off these crucial stem cells in the brain. What Does it Mean Over Time? Long-term, researchers think these results suggest long-term effects from binge drinking in teenagers. It may also be part of the reason why binge-drinking teenagers are more likely to develop alcohol dependence when they grow up into adulthood.

11 Issues in Underage Drinking Underage drinking is a huge problem in Britain and around the world. Many government-mandated initiatives have worked to combat binge-drinking in youth but it remains a major public challenge. There are already many known health consequences as well as an increased risk of alcoholism when a person is an adult. But now, this new study gives us yet another strong reason to put greater effort into reducing the incidence of underage drinking especially binge-drinking. Reducing Binge Drinking Around the World This study may help us to provide young people with enhanced education around how alcohol affects their brains, especially in relation to stem cells. With a growing body of evidence to suggest that alcohol harms stem cells in addition to all the other known damage, it s more important than ever to find ways to reduce the incidence of binge drinking.

12 Building a Windpipe from Stem Cells Stem cells have been touted as the treatment of the future for many diseases but perhaps surprisingly, they have also made the news recently for their ability to rebuild areas of the body that have suffered from tissue destruction. These types of procedures have previously been difficult and unsuccessful ones, partly due to immunological rejection of tissue transplanted from someone else as well as the mechanics of mimicking function and form for real human tissue. Creating a Windpipe For one patient, this treatment was not only a reality but also a livesaving one. Her trachea or windpipe was essentially 'rebuilt' using her own stem cells. The newly built trachea then gave her an airway that functioned properly, which ultimately saved the patient's life. Functioning Windpipe The airway had all the mechanical properties that are necessary to ensure the woman was able to breathe properly. In fact, when doctors did testing on her lung functioning a couple of months after the transplant, she performed at the high end of the normal result for a woman of her age. Disease and Tissue Destruction The woman had previously suffered from tuberculosis, which left her in the hospital as she struggled with breathing difficulties. At the young age of thirty, she had two children and couldn't adequately care for them or function on a day-to-day basis. Other methods of trying to rebuild or replace parts of the airway haven't been successful and removing one of her lungs still carried an enormous risk of complications. Responding to Urgent Need Since her case was a very urgent one and the research team involved had experienced success in laboratory work with tissue transplantation, they decided to create a new airway using the woman's own stem cells. The team started out with a piece of trachea from a donor who had just died and then they performed a procedure over the next month and a half to remove all traces of donor cells. The woman who was set to receive the rebuilt trachea had bone marrow stem cells from her body extracted and grown in the laboratory before the trachea was finished with her own cells and then transplanted into her body. The results were positive and exciting for everyone involved, not only because the procedure restored the woman's airway functioning but also because it signalled renewed hope for others who suffer from tissue destruction due to injury or disease. The woman's ability to perform daily tasks when she previously was challenged as well as her ability to now mother her children without restriction has been a positive outcome for everyone.

13 Advancing Stem Cell Research This accomplishment is particularly exciting for researchers because it shows that stem cells can effectively rebuild damaged tissue in the body. The risk of immunological rejection is dealt with because the adult stem cells are taken from the recipient's own body. There is also no need for the recipient to take special immune-compromising drugs to reduce the risk of rejection, which further increases the success and health of the recipient transplantation. Hopefully, we will see more success in tissue transplantation for future disease sufferers.

14 Restoring Eyesight After Chemical Burns: A Case Study Millions of people suffer from damage to their cornea all occurring from a wide range of injuries that can leave a person with irreversible damage to their eyesight. Corneal issues and injuries are a top cause of visits to eye care clinicians. As expected, losing eyesight is a devastating experience for those who suffer from corneal damage. Accessing Corneal Treatment In fact, those who are fortunate may qualify for a cornea transplant but in an ideal world, a solution would involve restoring a person s eyesight naturally. Even more ideal would be if everyone could access such a treatment, without having to wait for invasive surgery that does not guarantee successful restoration of eyesight. Repairing the Cornea Using Stem Cells In a recent study, scientists showed positive results when they tried to restore eyesight after corneal damage had occurred to a patient. The treatment uses the patient s own stem cells, reducing the concerns about immunological rejection. By using the patient s limbal stem cells, which are found at the corneal edge and are unscathed, researchers were able to coax the cells to grow new tissue. This tissue was then grafted into the eyes of the patient. Ten years later, the procedure was still successful. How is it Different from a Corneal Transplant? In a corneal transplant, the damaged or diseased part of the cornea known as the button is removed and replaced with the donor s button. As with many transplant procedures, the donor s body has to match the patient s or the patient is likely to suffer from immunological rejection. This means their body senses the foreign tissue and attacks it, treating it as an invader. The new stem cell procedure removes this issue and allows for a patient s own stem cells to be used, rather than spend time and effort looking for a donor. It opens the door to faster treatment that has a greater chance of success. Who Benefits from the Stem Cell Treatment? There are many reasons people can suffer from corneal damage. Researchers particularly want to help those who work in fields where there is a high risk of corneal damage. This includes people who provide relief for oil spills and are exposed to chemicals that can burn the eyes. Thousands of people suffer from chemical eye burn injuries at work each year and this treatment could save their eyesight.

15 Other people who may benefit are those who suffer from side-effects that target the eye, such as inflammatory diseases, including lupus and shingles. Once the stem cells regenerate this outer layer of the cornea where damage often occurs, eyesight can be restored. Eyesight Restored After Stem Cell Treatment One of the exciting aspects of this research is that a man who had been blind for fifty years had his eyesight restored one year later. While corneal damage implies a need to provide treatment soon after the damage, in reality the treatment can help people after they have suffered from decades of blindness.

16 Bone Marrow Stem Cells and Diabetes The prevalence of diabetes has been growing and the goal of finding a cure or more effective treatment than current options has become increasingly important. Ongoing research since the turn of the century has shown that when diabetic mice are injected with bone marrow stem cells the stem cells were able to restore function to damaged tissues. The findings are exciting for both researchers and those who suffer from diabetes. It is hoped that continuing trials and research will eventually bring effective treatments to the public. What is Diabetes? Diabetes refers to a condition whereby the body can t produce the hormone insulin or the body s cells are resistant to its effects. For type 1 diabetics, their pancreas doesn t produce the insulin required to keep blood sugar within its preferred, finely tuned range. In type 2 diabetes, insulin production generally occurs, albeit abnormally but the body s cells can t properly use the hormone to regulate blood sugar. Diabetics may be insulin dependent, where they require daily doses of insulin to balance out their food consumption, or they may be able to manage their condition with diet and exercise. The complications of diabetes are, however, enormous. Diabetes has a high morbidity, with complications ranging from circulatory problems, nerve problems and heart disease to blindness. In addition, the daily challenge of monitoring lifestyle and taking insulin when required can be mentally and physically exhausting for many diabetics. Benefits of Stem Cells for Diabetes Studies in both Canada and the United States found that when stem cells were injected into the bloodstream of diabetic mice, the stem cells found their way to the damaged pancreas, where they were able to prompt the growth of new cells. It s thought that something in the bone marrow somehow activates the regeneration of cells. In one study, the symptoms of diabetes were reversed within two weeks of the mice receiving bone marrow stem cell injections. Their high blood sugar levels were reduced to almost normal values and their insulin levels were raised. Even more interesting was that the cell growth wasn t from the injected cells themselves. Rather, the injected stem cells triggered the production of cells in the recipient s own pancreas. The results were particularly fascinating to researchers also because when stem cells were injected in healthy, non diabetic mice, there was no change. It s almost as though the stem cells were intelligent, in that they sought out the damaged tissue and triggered the new cell growth. Another benefit of using bone marrow stem cells is that they can be harvested from the patient s own bone marrow, cultivated in the lab environment and then injected back into the patient, where they can travel to the damaged pancreas and stimulate healthy cell growth. This helps to avoid the problems associated with immunological rejection, where the recipient s body recognizes the injected cells as foreign and launches an attack. Research Complications

17 Because it literally takes decades of research and trials before a new drug is introduced to the public, it will be some time before this treatment would be available for diabetics, assuming that human trails are successful. Given both the short and long term complications of diabetes, however, the research still provides hope that we may one day find a cure for diabetes.

18 Stem Cells to Treat Blindness For people who are blind, the thought of a treatment to restore their sight may seem like an impossible dream. But it may eventually become a reality after scientists last year were able to restore the eyesight of a blind person. The treatment works by replacing those cells in the eye know as retinal cells that have been damaged or worn out from diseases such as macular degeneration. For the elderly in particular, macular degeneration is a common concern as it can lead to enormous loss of vision in one or both eyes. What is Macular Degeneration? Macular degeneration is a top cause of vision loss in older adults. This is the most common illness that results in blindness in the elderly or for those people who lose their eyesight due to diabetes. It wrecks havoc on a person's central vision. This kind of vision is important for helping us to see objects clearly as well as helping us to perform basic, everyday tasks such as reading a book or driving a car. When macular degeneration strikes, it affects the area of the eye that is important for allowing us to see fine details. The disease may progress very slowly so that a person barely notices any changes at all. Or, it might progress rapidly, causing significant vision loss. Stem Cell Therapies Those who might benefit the most from this stem cell treatment are people who suffer from macular degeneration. But researchers think it could work for other kinds of vision loss as well. How it Works To perform the stem cell transplant, researchers initially tested things out in blind mice. They injected stem cells into the rear of the eye. The stem cells were able to replace the damaged photoreceptors, which are small, important cells found in the retina. These photoreceptors are vital to your ability to see things and they are very sensitive to light. Interestingly enough, previous studies using stem cells had failed to restore sight. One reason for the problem relates to the choice of stem cells. In the most recent study, researchers used stem cells that were more mature than the ones previous researchers had used. The choice proved successful as the stem cells developed into photoreceptors and were able to join with the nerves that lead to the brain. Researchers hope to see these kinds of transplants happening on a greater scale in approximately ten years. With many patients suffering from diseases in the eye that cause photoreceptors to die, this research offers a way to provide photoreceptor transplantation, helping to restore eyesight for many people around the world. The use of a patient's own cells also avoids the potential for immunological rejection, a threat that comes with other types of treatment. Cautiously Optimistic Experts do still tend to warn that we should not assume this study means we automatically have a cure for blindness. It is just one case study and there are still a number of challenges and risks that come with

19 the treatment. But it does offer hope for people who are blind from macular degeneration that they may one day have their eyesight again.

20 Therapeutic Cloning When people think of the word 'cloning' they are often hit with frightening images of duplicate human beings being created in somewhat of a mad scientist style experiment. In fact, many members of the public were outraged when Dolly the sheep resulted from a cloning experiment in Scotland. Therapeutic cloning, however, is entirely different and does not involve the creation of a perfectly copied human being. It is reproductive cloning that results in a copy of a specific human being. In therapeutic cloning, no sperm fertilisation is involved nor is there implantation into the uterus to create a child. How is Therapeutic Cloning Performed? Therapeutic cloning is another phrase for a procedure known as somatic cell nuclear transfer (SCNT). In this procedure, a researcher extracts the nucleus from an egg. The nucleus holds the genetic material for a human or laboratory animal. Scientists then take a somatic cell, which is any body cell other than an egg or sperm, and also extract the nucleus from this cell. In practical human applications, the somatic cell would be taken from a patient who requires a stem cell transplant to treat a health condition or disease. The nucleus that is extracted from the somatic cell in the patient is then inserted into the egg, which had its nucleus previously removed. In a very basic sense, it's a procedure of substitution. The egg now contains the patient's genetic material, or instructions. It is stimulated to divide and shortly thereafter forms a cluster of cells known as a blastocyst. This blastocyst has both an outer and inner layer of cells and it is the inner layer, called the inner cell mass that is rich in stem cells. The cells in the inner cell mass are isolated and then utilised to create embryonic stem cell lines, which are infused into the patient where they are ideally integrated into the tissues, imparting structure and function as needed. Benefits of Therapeutic Cloning A major benefit of therapeutic cloning is that the cells removed are pluripotent. Pluripotent cells can give rise to all cells in the body with the exception of the embryo. This means that pluripotent cells can potentially treat diseases in any body organ or tissue by replacing damaged and dysfunctional cells. Another distinct advantage to this type of therapy is that the risk of immunological rejection is alleviated because the patient's own genetic material is used. If a cell line were created with cells from another individual, the patient's body would be more likely to recognise the foreign proteins and then wage an attack on the transplanted cells. The ultimate consequence would be a rejected stem cell transplant. This is one of the major challenges of organ transplants, alongside the fact that there is a huge shortage of available organs for those who require the procedure. This means that therapeutic cloning has the potential to dramatically reduce the wait times for organ transplants as well as the immunological concerns associated with organ transplant therapy. Therapeutic cloning is also important to enhancing our understanding of stem cells and how they and other cells develop. This understanding can hopefully lead to new treatments or cures for some of the common diseases affecting people today. In addition, the procedure would allow for scientists to create stem cell therapies that are patient specific and perfectly matched for the patient's medical condition.

21 Problems with Therapeutic Cloning One problem with therapeutic cloning is that many attempts are often required to create a viable egg. The stability of the egg with the infused somatic nucleus is poor and it can require hundreds of attempts before success is attained. Therapeutic cloning does result in the destruction of an embryo after stem cells are extracted and this destruction has stirred controversy over the morality of the procedure. Some argue that the pros outweigh the cons with regards to treating disease whilst others have likened the destruction to an abortion. Still others state that this doesn't change the fact the embryo could potentially be a human being and so destruction of the embryo is no different than destruction of a human life. Because reproductive cloning does utilise SCNT as the primary step, there is also still fear that given our knowledge base to perform reproductive cloning, a scientist may attempt to move beyond therapeutic cloning to creation of a human being. To this date, no human being has been successfully cloned but the possibility of this occurring is a frightening one not only for the general public and policy makers, but also for most of the ethical scientific field. The majority of scientists are adamantly opposed to reproductive cloning and instead, support therapeutic cloning for treating disease. With policies and careful monitoring in place to ensure that therapeutic cloning is used responsibly, we can all benefit from the potential of this procedure to eventually treat, or perhaps one day cure, many diseases.

22 Bone Marrow Stem Cell Harvest A bone marrow stem cell transplant uses stem cells derived from bone marrow to provide a fresh and healthy source of new blood cells which in turn, allows for a patient to receive higher doses of chemotherapy to treat certain types of cancer such as leukaemia. This ultimately means that a person has a better chance of surviving cancer. The bone marrow stem cells may be allogeneic and therefore donated by a family member of stranger, or they may be autologous, which utilizes a patient's own stem cells. Importance of Bone Marrow Bone marrow is the soft tissue found in the centre of bones. It is here that new blood cells are formed; stem cells are considered the parent cells of these blood cells. Stem cells in the marrow have the vital task of creating a person's three blood cell types. These are: Red blood cells: transport oxygen White blood cells: fight disease Platelets: aid in clotting after injury Bone marrow stem cells are found in bone marrow and in a person's blood. After stem cells multiply, they form immature blood cells, which are then subject to a collection of changes that allow them to develop into mature blood cells. Once mature, the blood cells migrate from the marrow and are introduced into the bloodstream, where they provide important functions in keeping the body alive and healthy. Effects Of Chemotherapy On Bone Marrow Because chemotherapy operates by destroying the fast growing cancer cells, higher levels are generally more effective for killing cancer cells. Similar to cancer cells, however, bone marrow cells grow quickly and are also very sensitive to chemotherapy treatment. The chemotherapy can eventually destroy the marrow completely, which then prevents new and healthy blood cells from developing. Autologous Bone Marrow Stem Cell Harvest In an autologous transplant, a patient's own stem cells are used. The problem here is that the patient s bone marrow and peripheral blood usually have a lot of cancer cells, so isolating stem cells can't generally occur until the patient is in remission. A patient will usually receive some chemotherapy to reduce cancer cells before stem cells are collected. The harvested stem cells are also treated to ensure that no cancer cells remain. Higher doses of chemotherapy are then given, sometimes alongside complete body radiation, to confirm that no cancer remains. Stem cells are then transplanted back into the body via a rapid injection. Stem cells will eventually migrate to the bone marrow, where they latch onto other cells there and develop into the different blood cells.

23 Allogeneic Bone Marrow Stem Cell Harvest In the allogeneic transplant, a suitable donor is used; this may be a family member or a person unrelated to the patient. Similar to the autologous bone marrow stem cell harvest, a patient receives high doses of chemotherapy and possibly also radiation therapy. This therapy will destroy the patient's marrow and immune system, so that the patient's immune system can't attack the transplanted cells that are received from the donor. Graft rejection is a very real concern for allogeneic transplants, where the recipient's immune system recognizes the transplanted cells as 'foreign' and launches an immune attack. Prior to the transplant, red blood cells in the stem cell sample are usually identified and discarded and particularly so if the donor's blood group is different from that of the patient. Stem cells are then infused into the patient via an intravenous line over several hours. Stem cells travel to the patient's bone marrow where they develop and produce the blood cells necessary for blood functioning. Patients may also still be given drug therapy for some time to reduce the chances of immune rejection. Bone marrow stem cell harvests are clearly a life saving technique for those suffering from certain cancers such as leukaemia. They are one of the 'older' stem cell therapies and have been proven effective for decades now. There are, however, still issues of rejection that warrant further development and refinement of stem cell harvesting techniques. It is hoped that scientists will continue to focus on research to improve the odds of success for this important treatment.

24 Cancer and Stem Cells Cancer afflicts millions around the world each year and many go through treatment only to relapse years later. Others die from the disease and often after a great deal of suffering. It's no surprise that cancer research is at the forefront for current medical studies. In particular stem cells are being used for cancer treatments today as well as driving current research efforts in the hopes of finding more effective cancer treatments, including the ultimate goal of a cure. Current Stem Cell Treatments for Cancer Adult stem cells have been used for decades to treat certain cancers through bone marrow transplants. In this therapy, the stem cells that give rise to the different blood cells in the body are transplanted into the bone marrow of the patient, where they regenerate the blood. This is a vital and often life saving treatment because chemotherapy destroys the bone marrow alongside cancer cells and the blood cells must be replenished for the patient's treatment to be successful. It is hoped that similar treatments for other forms of cancer, allowing for cancerous tissues in areas such as the brain to receive stem cells that replenish those that are damaged through radiation. Cancer Cell Biology Treating cancer directly is one aim of stem cell therapy, but understanding cancer biology is another important one. In fact, it's crucial because that understanding can then encourage the development of drugs and cancer treatments. Some of the more recent studies have shown that cancers seem to be regularly maintained by a relatively small cluster of cancer stem cells that are able to self-renew. Scientists are trying to learn more about the genes that regulate the self-renewal feature of stem cells so that drugs can be developed to destroy the cancer stem cells. Stem Cells and Tumours Another important focus involves identifying and isolating cancer stem cells from tumours so that researchers can look at how cancer genes are expressed. The connection between cancer stem cells and healthy ones is also being investigated in research studies. Stem Cell Development and Cancer Even when cancers develop in different tissues, they can still have similar genetic abnormalities. An important scientific focus is to identify all of these genetic abnormalities and develop treatments to combat the effects. By examining the developmental process of healthy stem cells, scientists can better understand how abnormal differentiation occurs and develop treatments to prevent or treat the abnormalities. An understanding of how stem cell differentiation and specialisation are controlled is another fundamental development process that will help researchers create effective cancer treatments. Because cancer rates have significantly increased over the last century and the incidence is such that even if you do not suffer from cancer in your lifetime, you will likely know someone who does, stem cell research must continue in this area. The chance to save lives and decrease suffering is exactly the sort of motivation that should support further stem cell studies for cancer treatments.

25 Stem Cells for Stroke Victims Brain damage that results from stroke is an enormous challenge to address for people around the world. That's why research into stem cell therapies for stroke victims is so vital to reduce the devastating effects of stroke on its victims. Stem Cell Study A new study is set to go ahead in the United Kingdom (UK) to find out if stem cells are able to repair brain damage suffered by stroke victims. The company is aiming to begin clinical trials in the first half of this year on twelve patients. While there has been some preliminary success on stem cell treatments for similar brain damage, this new study will address a condition that has widespread effects. Designing the Study In this British study, stroke victims will have neural stem cells injected into their skull. While it sounds quite graphic, the injections will involve a very fine syringe and will target the parts of their brains that have been more severely affected by the stroke. Researchers hope that these neural stem cells will then develop into healthy brain tissue as well as neurons and other related, supportive structures in the brain. If the study proves successful, it will mean that the stroke victim's brain will have newly restored connections a better, healthier brain network, so to speak. Taking Animal Studies to Humans So far, we have also seen positive results from studies in mice, where they were able to regain brain functioning following injury to the brain. These kinds of animal experiments have prompted the need for human studies and it is hoped that this new clinical trial will provide similar or greater success. One interesting aspect of this kind of study is that once the stem cells are injected, we don't know exactly how they work and develop in the brain. We can measure the outcomes of the procedure but we can't actually track everything that happens once the neural cells are injected. So, we don't know where they travel exactly or how they change and develop. Scans taken regularly can show brain functioning and activities after the treatment but the precise process by which the brain 'heals' is something that for now, will remain a mystery. At best, we can hope for a positive result by whatever physical mechanism occurs and perhaps in the future, we will also be able to observe the pathway itself by which stem cells help stroke victims. Awaiting Study Results Many of us will be anxiously awaiting the results of the study, which provides hope for the many people who have suffered from brain damage due to a stroke. For now, however, the best thing the rest of us can do is to focus on preventative strategies to reduce the likelihood of suffering from a stroke.

26 With stroke being as prevalent as it is, it's likely most of us will either suffer from a stroke at some point in our lifetime or we will know someone who does suffer from one and possibly has brain damage to some degree as a result. Hopefully, the new British study will offer hope for everyone who is affected by stroke or will be one day.

27 Improving Memory With Stem Cells For people who suffer from Alzheimer's disease, losing their memory is devastating. While there is a great deal of active research into how to treat the disease, we still don't know how to predict who will be diagnosed with Alzheimer's disease or how to effectively treat them. As the leading cause of dementia in the elderly, finding better ways to reduce the memory loss from Alzheimer's disease is a priority for researchers. Benefits of Neural Stem Cells A study using stem cells, however, suggests promise for potentially improving the memory of people who suffer from Alzheimer's disease. Researchers used mice to look at how stem cells could improve memory. They genetically engineered the mice to have Alzheimer's disease and treated them with stem cells. Neural stem cells were injected into the brain of each mouse. Results showed that the mice performed much better on memory tests one month after receiving the stem cell injections. Researchers believe the stem cells have a protein that improves neural connections, helping to enhance the cognitive performance of the mouse. But just how did it work? Regenerating the Brain Researchers were actually surprised when they looked at the mouse brains. They had thought that the neural stem cells might have become fresh, new neurons. Or they thought that perhaps the stem cells had reduced the plaques that are classic signs of Alzheimer's disease. Neither was the case. In fact, less than ten percent of the stem cells had become neurons. Instead, the stem cells had secreted a special protein. This particular protein triggers the growth of new neurites. These neurites grew from tissue that was already present in the brain. The result was that the neurites enhanced the connections between the brain's neurons. To confirm the results, researchers even reduced the protein from the neural stem cells and found that this benefit was removed. Improvement That Lasts Researchers also tried to just inject the mice with the protein, but although the mice showed some improvement, they did not show nearly as much improvement as when they received the neural stem cells. It seems that the injection of neural stem cells offers a longer lasting and more regular supply of this important protein. Understanding How it Works Researchers are still trying to make sense of the new findings. It seems that the plaques that are seen in patients who have Alzheimer's disease are not the key area to look at when it comes to dementia. It is the loss of connections from one neuron to another in the human brain.