Created By: Alberto Lopez
Good report only a few errors
Even though some may say there is no race more prevalent in others in hypertension, also know as high blood pressure, or has more people with a high blood pressure, people of an African descent, or blacks, are more prone to having these conditions. Hypertension is the result of high blood pressure. Hypertension is a disease that varies and anyone could have it regardless off your race, age, gender, or heredity.
Hypertension, also know as high blood pressure, is when the blood pressure in your arteries is at a higher level than what would be called normal. Hypertension is know to be subtle, gradual disease. Most people never develop problems from the high blood pressure its self, unless internal organs are damaged by the constant high pressure. (revise) (Fogoros 2011,2).
Since hypertension is capable of producing so many medical conditions, its best to diagnose and treat hypertension accurately and carefully (Fogoros 2011,3).
"Many doctors are ill-prepared to treat high blood pressure in older people," says Dr. Joseph L. Izzo and a expert on hypertension (Jaret 2011,1).
People are either not being treated enough or being treated to much. A few older people have been given medications that are too critical for their body. On these high doses of medication older people are at risk for fainting and falling (Jaret 2011,2).
Blood pressure changes when youre sleeping or awake, stress can affect the level and so can eating . Blood pressure changes all the time and doctors have made them selves familiar with the concept. They know of some conditions like the following. White coat hypertension is the tendency for some peoples blood pressure to increase in the doctors office. The opposite can happen, called "masked hypertension" where the blood pressure can read normal in the doctors office and increase as soon as the person gets home (Jaret 2011,5).
Hypertension is a "silent killer." It can be slowy killing your body for years before actual symptoms develop.
An effect of hypertension is having damage to your arteries. If your have high blood pressure, the raised pressure of blood flowing through your arteries can lead to artery narrowing. Fats from the foods you eat flow through your bloodstream and gradually collect and "harden" your arteries.This can block flow to to your heart, kidneys, brain, arms, and legs (Anonymous 2011,3).
Uncontrolled high blood pressure damages your heart by leading to coronary heart disease. Coronary heart disease affects arteries by not letting blood freely flow to the heart. Because of this you can go through chest pains or have a heart attack (Anonymous 2011,4).
High blood pressure can narrow or from blood clots in the arteries leading to your brain there striping your brain of proper blood flow. When your brain is deprived of the oxygen and nutrients it needs the brain cells die and a stroke occurs (Anonymous 2011,5).
The human body depends on healthy blood vessels for kidneys to be able to filter blood. High blood pressure injures the vessels leading in and out of your kidneys causing kidney diseases (Anonymous 2011,6).
Another effect that high blood pressure can have on your body is increasing the amount urine found in your urine(revise). A decrease in bone density is possible of leading to broken bones (Anonymous 2011,7). (elaborate)
So in all, problems that can develop because of high blood pressure is stroke, damage to your aorta, seizures, unstable chest pain, heart attacks, and sudden loss of kidney failure. Adding to high blood pressures effects on your brain, is that there could be memory loss, personality changes, trouble concentrating, irritability, and maintaining loss of consciousness (Anonymous 2011,8)
Factors that you cant control that contribute to developing high blood pressure are age, race, heredity, and gender. As a person gets older this will result in "hardening of the arteries" which most likely contributes to the developing of high pressure. With race being another factor of this condition an example is "African Americans develop high blood pressure more often than Caucasians. They develop high blood pressure at a younger age and develop more severe complications sooner in life" and this statement is also proof for the fact that there are ethnic differences in hypertension.The tendency to have high blood pressure also runs in families.(why?) And generally men have a greater chance of having this condition but varies in age and different ethnic groups (Wendro 2013,1)."
Factors you can control that contribute to developing high blood pressure are obesity, sodium sensitivity, alcohol use, birth control, lack of exercise and medications. As body weight increases the blood pressure rises as the heart has to work more. Some people are very sensitive to sodium and their blood pressure rises if they ingest it (salt/sodium). Reducing sodium intake usually lowers their blood pressure(explain). Learn how to read food labels and check out the salt content in products to reduce the amount of salt intake. Those who are sensitive to alcohol may have their blood pressure raised if they drink more than one or two drinks per day. Birth control pills may raise a woman's blood pressure.(explain) A lazy lifestyle adds to the development of obesity which leads to high blood pressure. Medicines also contain large amounts of sodium, many are over-the-counter. In addition certain drugs like stimulants, diet pills and a few cold and allergy medications tend to raise blood pressure (Wendro 2013,2)
With treatment and lifestyle changes you can lower your blood pressure and reduce your risk for having any complications. Exercising and watching your diet, or what you eat, are ways to help lower your blood pressure and risk for hypertension.
In 2002, hypertension was found in one of every three Americans and became a worsening problem because the number increased since the previous report (Anonymous 2005,1).
Research was continued with the study in 2002 with results of nearly 50 percent of Americans with hypertension were elderly (=65 years of age). Seven out of ten elderly Americans had hypertension. Around 80 percent of people with hypertension were either overweight or obese. "The highest prevalence occurs among blacks: a 46% prevalence rate compared with 29% among Hispanics, 32% in whites, and 33% in other ethnic groups." More black people were found with hypertension than Hispanic, whites and other groups. Age, race and obesity are strong factors in hypertension and high blood pressure in people. (Anonymous 2005,2).
Hypertension and high blood pressure is found in all races but is more prevalent in certain groups than others.(repeat)
However, a study done in 2001 in the UK has conflicting problems with the data on ethnic differences in blood pressure and hypertension prevalence. It didnt show that one group was was more prevalent in hypertension like how there are more blacks with hypertension or high blood pressure than any other races. For example it failed to find any significant difference between South Asian and blacks in their blood pressures. And when the blacks' blood pressures were compared with the whites' blood pressures the was no difference either (Lane et al 2001,3).(explain)
But in more recent studies done in the US there have been obvious differences in the ethnic difference in blood pressure and hypertension prevalence. In each study there was one group that had the highest level of people with high blood pressure and people with hypertension.
Racial and ethnic differences are seen when cardiovascular disease risk factors and out comes of African American people are compared with European Americans. African Americans had higher mortality rates for most cardiovascular diseases and a younger age (Jones et al 2006,1).
African Americans with prehypertension develop high blood pressure a year faster than Caucasians reported in Journal of the American Heart Association. African Americans with prehypertension also have 35 percent chance of progressing to high blood pressure than Caucasians. “The fact that African-Americans progress faster to hypertension has a direct link to the higher prevalence of hypertension and its complications, such as stroke and kidney disease, in blacks than whites,” said Dr Selassie (Wagner et al 2011,2). (further explanation)
"According to recent statistics by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, compared to Caucasians, African Americans have a 1.3-times greater rate of nonfatal stroke, a 1.8-times greater rate of fatal stroke, a 1.5-times greater rate of heart disease death and a 4.2- times greater rate of end-stage kidney disease." In the African American community those with the highest rates were more likely to be middle aged or older (Boyer 2011,2).
A survey was done in the United States from 1994 to 2004. Mexican Americans and non Hispanic whites were more likely to have normal blood pressure compared to non hispanic blacks. The non Hispanic blacks had higher percentages on people who had hypertension stage 1 and hypertension stage 2 compared to the non Hispanic whites and Mexican Americans (Anonymous 2007,1).
People with an African descent seem to develop high blood pressure at a younger age and continue to obtain more severe complications in life (Wendro 2013,1). (further explanation)
Another reason why African Americans tend to have a higher blood pressure could also be because of culture and their environment.
Hypertension is quite heavy on other certain ethnic groups also. For example, compared to Caucasians, people of an African descent have a high risk of stroke and end-stage renal failure but are not common with coronary heart disease whereas South Asians are common in (Lane et al 2001,1).
"We previously examined the association of patients' race/ethnicity with processes of hypertension care . We found that, among a cohort of hypertension patients with repeatedly elevated blood pressures, Hispanics were significantly less likely to have therapy intensified and were more likely to have uncontrolled blood pressure (BP) than were other racial and ethnic groups. In an effort to identify potential targets for interventions to improve hypertension care among our patients, we further examined which patient and provider characteristics may explain racial differences in rates of therapy intensification (LeRoi et al 2005,2)." Hispanics were compared with other ethnic groups and were found more likely to have uncontrolled blood pressure.
In conclusion, there is an ethnic difference in blood pressure and hypertension prevalence. People of an African descent are more prone to developing or having hypertension and high blood pressure. Before people have said that there is not enough evidence to prove that there is ethnic difference because most studies were not done on a very wide range of groups. For example African American and the Caucasian were the ones being compared the most but none of the ones inbetween are being studied but now there is newer research that proves blacks are more prone to hypertension and high blood pressure. I believe that blacks are more prone because of their culture and environment and the fact that this idea has been tested multiple times and turns out correct is proof for me.
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Created By: Alberto Lopez
Do you know someone who suffers from cancer? Chances are that you do. Cancer is a deadly disease that claims the lives of many each and every day. It is a leading cause of death worldwide and spreads pain and grief throughout communities. As the problem continues, many scientists are trying to find a cure to stop this vicious disease. Many different methods have been studied, researched, and experimented with. Although not all scientists agree, I believe that oncolytic virotherapy could contain the properties to make it the next revolutionary treatment that is able to effectively and efficiently cure cancer.
Cancer is a very significant and dangerous disease. It affects many people in today’s society. In fact, one of every four individuals' cause of death is cited as cancer (Siegel 2013, 1). There are over one hundred different types of cancer (Anonymous 2010, 3). Cancer occurs when damaged cells inside of the body begin to divide erroneously. This division causes lumps or masses, called tumors, to appear (Anonymous 2010, 1). These tumors begin to wreak havoc with the body. They can grow incredibly large, interfere with vital systems within the body, and release hormones that conflict with normal body functions (Acs 2013, 1). When cancer cells successfully invade the body and begins to spread to other parts of the body, metastasis is said to have occurred. (Anonymous 2010, 2). Some forms of cancer, such as leukemia, do not result in the formation of tumors. It is no surprise that cancer has a high death rate once if it is not diagnosed quickly. If the disease cannot be caught quickly and treated, an individual is likely to face debilitating symptoms, including death (Acs 2013, 2). The impact of cancer is undeniable. In 2013 alone, there will be 1,660,290 new cases of cancer and over 550,000 deaths resulting from this deadly disease (Siegel 2013, 2) (Acs 2013, 3 & 4). While there is not yet a complete cure for cancer, many scientists are out in the field working hard to find a solution.
One form of biotechnological engineering that has gained a lot of attraction in recent years is oncolytic virotherapy treatment. Many scientists today believe that oncolytic viruses may contain the answer to ending cancer (Vile, Ando, et al. 2002, 1). Although this technique has been acknowledged and researched since the 1950’s, the lack of adequate resources and technology did not allow it to progress further (Li, Tong, et al. 2012, 6). However, the rapid growth of today’s society and its ingenuity has resulted in the reemergence and success of oncolytic virotherapy (Vile, Ando, et al. 2002, 3). Oncolytic virotherapy is the process by which certain viruses are introduced into the body. Viruses present an ideal way to attack cancer from the inside. These viruses selectively infect and break down cancer cells while leaving normal cells unharmed (Thompson 2013, 2). This targeted treatment makes it easier to kill tumor cells and lessen the impact of cancer on the body by eliminating cancerous cells (Paddock 2013, 3). Scientists believe that engineering oncolytic viruses to act as a biological weapon against cancer might be able to suppress or eliminate the disease completely. Although there are still many obstacles to get through, this new cancer treatment is starting to become more widely recognized as its unlimited potential continues to be tapped in to and developed further (Timmer 2013, 6). The promising results indicate that a solution for cancer may soon be found.
In oncolytic virotherapy, scientists alter the genetic makeup of viruses in order to optimize their chances of destroying, eliminating, and combating cancer (Thompson 2013, 2), (Timmer 2013, 2). These viruses are specifically made for this purpose and serve no other function. The process of oncolytic virotherapy is very complex. Viruses are engineered in many different ways and forms, each with their own use (Li, Tong, et al. 2012, 1). The most commonly used virus in this method of treatment is the adenovirus (Fikes 2013, 4). This virus is responsible for causing the common cold and has been intensively explored. It is particularly appealing because biologists understand its biological impact after years of curing colds and have abundantly used the virus in molecular biology and other research (Nettelback, Curiel 2008, 1). Adenoviruses also carry favorable, distinct traits. For example, the genes that they carry into a cell work for a short period of time and then break down, making them viable candidates for genetic selectivity that do not permanently damage the body. Viruses can be applied through various means. Methods of applications include intramural delivery, viral vectors, and intravenous injections (Ferguson 2012, 1). Two main strategies are used during virotherapy in order to reproduce viruses and kill cancerous cells and tumors. The first strategy, called transductional targeting, involves scientists attempting to engineer viruses to selectively infect and destroy cells that have turned cancerous (Nettelback, Curiel 2008, 3). This method is the most commonly used. The second approach occurs when a small part of DNA, known as a tumor specific promoter, is placed on the genes of the virus. The promoter activates and permits the gene to function only in cancer cells. The virus can enter normal cells, but the promoter will not activate within them, disallowing them to reproduce or kill healthy cells. However, once in the cancer cells, the promoter activates and lets the virus make millions of copies of itself, bursting the cancer cells and spreading to other cancerous cells in the process (Nettelback, Curiel 2008, 4).
Oncolytic irotherapy is very advantageous in many different ways. Some of the benefits of this method are that it is safe, can affect many types of cancer, and advances the medical field further than ever before (Nettelback, Curiel 2008, 6). Another reason that this method is favorable is because it is more efficient than traditional cancer eradication techniques, such as radiation and chemotherapy (Taber, Cheung 2010, 5). Oncolytic virotherapy kills a lower amount of healthy cells within the body, making it less damaging to important parts of the body such as bone marrow (Paddock 2013, 5). It can also affect a very broad spectrum of cancer types, making it a diverse and viable option. This method is very efficient at finding and eliminating cancer cells in the body without risking extra damage to other healthy cells that are not a threat (Taber, Cheung 2010, 6). The range at which oncolytic virotherapy is effective is large. One administration of a dose into an individual’s body can kill a large number of cancer cells and also provide access to tumors within the body that are in hard to reach places (Fikes 2013, 2). Lastly, the symptoms of oncolytic viruses are relatively tame in comparison to how much they help an individual. Within most clinical trials, patients given high dosage levels of oncolytic viruses only suffered flu-like symptoms lasting from twenty four to fourty eight hours (Paddock 2013, 5)(Li, Tong 2012, 5).
Although its potential is evident, using virotherapy to treat cancer also presents some disadvantages. When patients are given multiple doses of virus therapy, the immune system begins to send out antibodies and white blood cells that start to recognize the virus. As a result, subsequent doses end up being less effective because the immune system will immediately bind and deactivate the virus (Vile, Ando, et. al 2002, 5). One of the major concerns with this form of treatment is that it's long term effects are still relatively unknown. In 1999, an 18 year old died after receiving an infusing of virotherapy. His body shut down after an overwhelming immune reaction to the large dose of viruses he had been given (Nettelback, Curiel 2008, 2). Since virotherapy is relatively new and expanding, scientists are still working on making viruses safer, but it is still too soon for scientists to determine if there are any significant factors that could damage a patient using this form of therapy. Also, creating these new viruses and altering their genes presents the danger of creating serious mutations or dangerous new diseases altogether (Taber, Cheung 2010, 6). However, these risks are always present in any type of anti-cancer therapy. In order to cure a dangerous and deadly disease, researchers must be able to take risks within reasonable boundaries.
There have been many successful clinical trials of oncolytic viruses as cancer treatment. Many companies involved in oncolytic virotherapy have made significant progress and great strides in the field (Anonymous 2010, 4). In clinical trials, different phases are tested. Phase 1 tests are designed to make sure that the drugs are safe for patients receiving them. Phase 2 and 3 trials are performed in order to determine the correct dosage levels and how much power it takes to produce an effect. After these phases, the treatment gets circulated and, if they are approved, eventually get put on the market (Nettelback, Curiel 2008, 5).
Onyx-015, developed by Onyx Therapeutics, is a unique virus that has the potential to treat cancer effectively. Onyx-015 was created by genetically modifying an adenovirus and was extensively tested in trials to see if it could treat cancer (Thompson 2013, 3). This virus has the ability to detect the absence of p53, a specific protein with the body that all cancer cells lack (Timmer 2013, 3). As a result of this adaptation, the virus ignores normal cells and can only attack cancerous cells that lack the p53 protein. Onxy-015 is currently capable of targeting and destroying half of all major cancer types but is less effective against others (Vile, Ando, et al. 2002, 5). This virus has been tested in clinical trials extensively, with data suggesting that it is safe and selective for cancer (Li, Tong, et al. 2012, 3). However, the drug is ineffective alone and needs to be coupled with chemotherapy for optimal use, somewhat limiting its long term effectiveness (Ferguson 2012, 2). Research and funding has mostly ceased until the virus can show further potency.
Another virus that has undergone clinical trials in an attempt to defeat cancer is OncoVex, developed by BioVex (Thompson 2013, 5). Clinically, this drug can function by itself and does not need to be paired with other treatments, such as radiation or chemotherapy. This virus originates from a modified cold sore that replicates inside solid tumors, causing cancer cells to die (Nettelback, Curiel 2008, 7). Also, the drug prompts the immune system to flag and subsequently eliminate cancer cells (Nettelback, Curiel 2008, 8). One of the downsides of this virus is that it can only be directly injected into tumors, making it unable to reach and treat any metastatic tumors that may have spread throughout an individual’s body. This virus has currently completed Phase 2 trials and is expected to enter the next test of trials soon (Li, Tong 2012, 7). If successful, research will continue and the Food and Drug administration will consider the drug for approval.
However, one of the most effective clinical trial to date utilizes a genetically engineered vaccinia virus, known as JX-594, as its test subject (Ferguson 2012, 3). This virus is already widely used in vaccinations and has a reputation of being safe, making it a viable candidate to test against cancer. This particular virus was modified in order to make it more cancer selective. The virus also increases immune system stimulation (Li, Tong 2012, 4). This virus works in two different ways. First, the virus recognizes and targets cancerous cells and reproduces inside of them, resulting in their death. Secondly, the virus helps induce immune responses towards cancerous cells and makes the body attack cancer cells (Fikes 2013, 5). The results, reviewed by analysts, determined that all dosage levels resulted in anti-tumor activity (Li, Tong 2012, 5). Further research showed that the 69% of patients displayed some form of resistance to cancer. The average life span of cancer patients utilizing this drug was also increased. The JX-594 virus is currently in phase 3 clinical testing and its data looks very encouraging (Thompson 2013, 4).
Although oncolytic virotherapy has not yet been proven to completely cure the deadly disease of cancer, the success that it has experienced and impact it has made on the medical field has been undeniable. This form of virotherapy shows a promising future as more and more companies and biologists alike continue to invest their time into finding a cure for cancer. Although great strides have been made in this area, there is still plenty of room for more development. More viruses are continuing to be genetically modified and virotherapeutic strategies continue to be investigated. It is expected that the collective efforts of the biological researchers and pharmaceutical companies will continue to contribute to the development of effective and safe viruses for cancer therapy. Scientists have done the previously unthinkable. Viruses, things that were once a cause of sickness, are now being used to wage warfare against one of the top killers in the world. Medicine is being revolutionized once again as the goals of science are being tested upon and expanded further than ever previously thought. In order to move forward and continue with this promising research, we must continue to probe, dissect, and understand the potential that viruses carry.
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Created By: Alberto Lopez
Plants do amazing things. They can produce their own food by a process called photosynthesis, and are even able to grow up to 380 feet, but have you ever thought they would be able to power your television remote, electric toothbrush, or even fuel your car battery? latest discoveries in the madder plant (Rubia species), have shown purpuin which is much more environmentally friendly than the traditional ion battery, and can also perform better. I personally believe that batteries made from madder plant are more environmental friendly, as well as having a higher performance compared to the lithium ion battery. the madder plant has shown that the normal lithium battery is obsolete and performed better by storing more power and lasting longer.
Capitalize words and define some words that you used
2nd Semester Research Report
The first lithium ion batteries to appear in stores came in 1991 (Brodd 2012, 1). The use of the intercalated car- bon/graphite anode(define) took away the problems of the lithium metals ability to recharge because of the formation of dendrites and mossy lithium metal deposits with only a fairly small voltage penalty (brodd 2012, 2). Both the anode and cathode are lithium intercalation compounds(define) turned into polymer-bonded electrode structures based on polyvinylidene difluoride(define). The polymer allows the structure to have space and also takes account for the volume changes that occur in the active materials during both, charge and discharge (brodd 2012, 3). the battery cell operates by intercalation and de-intercalation of lithium ions into the anode and cathode, being dependent on whether the cell is being charged or discharged (brodd 2012, 4). This has been called to by many battery-making industries as a "swing", "rocking chair", or "lithium-ion" concept of cell operation (brodd 2012, 5). There is no lithium metal in the cell,contrary to popular belief, only lithium ions. The electrolyte is a mixture of alkyl carbonate solvents with lithium hexafluophosphate salt to provide conductivity for the battery cell(define) (brodd 2012, 5). The market for Li-Ion cells is driven by the demand of the portable electronic device market, especially the portable computer device, also known as the laptop. Another product that drives the demand of the lithium ion battery up is the cellular telephone, also known as the cell phone.This market has had explosive growth in these products (brodd 2012, 6). The growth in demand for higher performance battery systems has risen quite rapidly over the past years, and this shows the increase in capacity since the initial commercial introduction in for the cylindrical 18650 cells(define). This remarkable increase in volume has been brought to the light through engineering improvements in the manufacturing processes as well as the introduction of new separator, cathode, and anode materials (brodd 2012, 7). There has been an intense effort to develop new materials. The original lithium cobalt oxide(define) has been changed by mixing in certain additives to stabilize the crystal structure and increase the capacity of the battery cell (brodd 2012, 8). while innovations in the lithium ion battery continue to advance, so does the mining of certain rare minerals. the amount of materials becoming obtained can be potentially dangerous to the environment; therefore, need new and improved batteries to power our new technologies, and to stop and take into consideration if we can keep grieving these materials from the earth.
Early attempts on lithium ion batteries built from organic cathode materials (polyaniline), met with limited success due to numerous drawbacks such as temperature stability, limited rate capability (low power density), as well as low specific and volumetric energy density problems (reedy 2012, 1). Recently, Tarascon and co-workers came up with an innovative step towards the development of organic electrode materials through what they call "an elegant process". Their recent work on conjugated dicarboxylate anodes and lithium salt of tetrahydroxybenzoquinone(define) suggested a possible alternative to current inorganic based electrodes, which are extremely hazardous to the environment. Recent studies on bio-based materials show and demonstrate the prudent use of biomass for value-added chemicals and products in a bio refinery concept (reedy 2012, 2). organic electrode material for lithium ion batteries, also called purpurin, has been taken and extracted from a common plant called Madder, most often used as a dye for fabrics. The extracted and chemically lithiated purpurin, shows extremely well reversible lithium ion storage properties; therefore, it could lead to the development of a green, environmentally friendly and sustainable, Li ion battery (reedy 2012, 3).
Now this is where it gets scientific. To realize the reversible electrochemical performance of this novel electrode material, a working electrode was prepared by mixing 80% of purpurin/CLP and 20% of carbon by weight. Figure 1 (a)(delete) shows the cyclic voltammogram(define) of the purpurin electrode conducted at scan rate of 0.1 mVs−1 in 1 M solution of LiPF6 in 1:1 (v/v) The mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)(define) as an electrolyte against Li metal and is a counter and reference electrode. The cyclic voltammogram measurement of the purpurin electrodes showed reversible lithiation/de-lithiation process in the purpurin molecule. The first cathodic(define) scan showed a peak around. As it can be observed from the cathodic scan of the cyclic voltammogram the lithiation process begins at 2.4 and becomes quite large at ~2.0. The firstanodic(define) scan has shown two small peaks around ~2.6 and 3.2, respectively, associated with the de-lithiation process of purpurin. In the following scans of the cyclic voltammogram, the peaks of the cathodic scan shifts to the right by ~0.2, hence reducing the hysteresis(define)between the anodic and cathodic peaks. This leads to better reversibility of the electrode around ~2.0 (reedy 2012, 4).
There is scientific proof that the lithium ion battery produced by the Madder plant is environmentally friendly . environmental(again) requirements regarding the mobility of energy usage are forcing most automakers to develop hybrid electric vehicles, which allows for a more efficient and thus, less polluting use of fossil fuel combustibles (electrochem 2010, 1). Purpurin, extracted from madder root, center, is chemically lithiated for use as an organic cathode in batteries (milo 2013, 1). even if it has been proven that these batteries are more sustainable to the environment, the concentration of these batteries aren't that large. "Green batteries are the need of the hour, yet this topic hasn't really been addressed properly," Reddy said. "This is an area that needs immediate attention and sustained thrust, but you cannot discover sustainable technology overnight." He says the focus of the research community is currently still primarily on improving the features of conventional batteries. Issues such as sustainability and recyclability tend to get sidelined (milo 2013, 2)."Though lithium-ion batteries are the standard," Reddy said, "rechargeable units cost a lot to produce.They're not environmentally friendly. They use cathodes of lithium cobalt oxide, which are very expensive. You have to mine the cobalt metal and manufacture the cathodes in a high-temperature environment (milo 2013, 3). And then, recycling is a big issue," he said. "In 2010, almost 10 billion lithium-ion batteries had to be recycled, which uses a lot of energy. Extracting cobalt from the batteries is an expensive process. Eliminating cobalt would mean eliminating a hazardous material, allow batteries to be produced at room temperature, and greatly reduce the cost of recycling" (milo 2013, 4). Moreover, growing Madder, or other biomass crops to make batteries would soak up carbon dioxide and eliminate the disposal problem -- without its toxic components, a lithium-ion battery could be thrown away (reddy 2011, 3). Best of all, purpurin also turns out to be a no-fuss ingredient. "In the literature there are one or two other natural organic molecules in development for batteries" (reddy 2011, 4).
there is also reason to believe that obtaining these batteries in the future will be better for you, the consumer. first, the consumer can save money by using rechargeable Nickel Metal Hydride (NiMH) and Lithium Ion (Li-Ion) batteries (cooper 2012, 1). eventually, alkaline batteries can be replaced with higher capacity, environmentally friendly, rechargeable NiMH or Lithium-ion (Li-ion) batteries (cooper 2012, 2). What's more, rechargeable batteries are usually much less expensive to use - if you know the right ones to buy and the best way to use them to get the most out of your purchase. Too many people just buy batteries arbitrarily (define) and then have a bad experience and just go back to, single use, throw away batteries (cooper 2012, 3). the battery can be made by just a few easy steps: dissolve the purpurin in an alcohol solvent and add lithium salt. When the salt's lithium ion binds with purpurin the solution turns from reddish yellow color to pink. The chemistry is quite simple (reddy 2011, 5). (don't use the words "you" or "I")
The future outlook of the Madder battery also looks quite good for the consumer, as well as for the environment. The team estimates that a commercial green Li-ion battery may be only a few years away, counting the time needed to ramp up purpurin's efficiency or hunt down and synthesize similar molecules. We can say it is definitely going to happen, and sometime soon, because in this case we are fully aware of the mechanism (reedy 2011, 6). The goal, according to lead author, Arava Leela Mohana Reddy, a research scientist in the Rice lab of materials, is to create environme ntally friendly batteries that solve many of the problems with lithium-ion batteries in use today (williams 2012, 2).
Also, there is scientific proof that the Madder plant version of the lithium battery can actually outperform the ion battery. Li4Ti5O12, which is a high performance anode material for rechargeable Li-ion batteries (electrochem 2012, 1). Crystalline nanoparticles(define) are obtained in a single step and in less than one minute, by mixing the reactants with superheated water in a continuous flow reactor at near- and supercritical conditions (electrochem 2012, 2). overall, the annealed(define) nanoparticles have excellent electrochemical properties (electrochem 2012, 3). further optimization of this rapid, green and scalable synthesis approach is suggested (electrochem 2012, 4).
All in all, I personally believe that batteries made from the madder plant are more environmentally friendly, as well as a higher performer compared to the lithium ion battery. the madder plant has shown that the normal lithium battery is obsolete. it shows this by being more environmentally friendly, as well as performing better by storing more power and lasting longer. the madder battery is soon to be within the consumers grasps. as technology and research in the madder plant continue to advance, so does the day the consumer sees one hundred percent organic batteries in all local stores. if more people in the world start seriously considering organic batteries to power their everyday things, research will continue, and eventually replace the lithium ion battery. can you imagine using your cell phone, computer, clock, flashlight, cd player, and even your car running off of something that grew in the floor? this can become a reality if we, as a human race, join together and start considering the madder plant for our batteries. all we need is YOUR support!
Category: Spring Research | Comments: 0 | Rate:
Created By: Alberto Lopez
By Rick Weiss
Photographs by Max Aguilera-Hellweg, M.D.
Embryonic stem cells may someday help doctors treat ills from paralysis to diabetes. But science must contend with politics before that hope can be realized.
Get a taste of what awaits you in print from this compelling excerpt.
In the beginning, one cell becomes two, and two become four. Being fruitful, they multiply into a ball of many cells, a shimmering sphere of human potential. Scientists have long dreamed of plucking those naive cells from a young human embryo and coaxing them to perform, in sterile isolation, the everyday miracle they perform in wombs: transforming into all the 200 or so kinds of cells that constitute a human body. Liver cells. Brain cells. Skin, bone, and nerve.
The dream is to launch a medical revolution in which ailing organs and tissues might be repaired—not with crude mechanical devices like insulin pumps and titanium joints but with living, homegrown replacements. It would be the dawn of a new era of regenerative medicine, one of the holy grails of modern biology.
Revolutions, alas, are almost always messy. So when James Thomson, a soft-spoken scientist at the University of Wisconsin in Madison, reported in November 1998 that he had succeeded in removing cells from spare embryos at fertility clinics and establishing the world's first human embryonic stem cell line, he and other scientists got a lot more than they bargained for. It was the kind of discovery that under most circumstances would have blossomed into a major federal research enterprise. Instead the discovery was quickly engulfed in the turbulent waters of religion and politics. In church pews, congressional hearing rooms, and finally the Oval Office, people wanted to know: Where were the needed embryos going to come from, and how many would have to be destroyed to treat the millions of patients who might be helped? Before long, countries around the world were embroiled in the debate.
Most alarmed have been people who see embryos as fully vested, vulnerable members of society, and who decry the harvesting of cells from embryos as akin to cannibalism. They warn of a brave new world of "embryo farms" and "cloning mills" for the cultivation of human spare parts. And they argue that scientists can achieve the same results using adult stem cells—immature cells found in bone marrow and other organs in adult human beings, as well as in umbilical cords normally discarded at birth.
Advocates counter that adult stem cells, useful as they may be for some diseases, have thus far proved incapable of producing the full range of cell types that embryonic stem cells can. They point out that fertility clinic freezers worldwide are bulging with thousands of unwanted embryos slated for disposal. Those embryos are each smaller than the period at the end of this sentence. They have no identifying features or hints of a nervous system. If parents agree to donate them, supporters say, it would be unethical not to do so in the quest to cure people of disease.
Few question the medical promise of embryonic stem cells. Consider the biggest United States killer of all: heart disease. Embryonic stem cells can be trained to grow into heart muscle cells that, even in a laboratory dish, clump together and pulse in spooky unison. And when those heart cells have been injected into mice and pigs with heart disease, they've filled in for injured or dead cells and sped recovery. Similar studies have suggested stem cells' potential for conditions such as diabetes and spinal cord injury.
Critics point to worrisome animal research showing that embryonic stem cells sometimes grow into tumors or morph into unwanted kinds of tissues—possibly forming, for example, dangerous bits of bone in those hearts they are supposedly repairing. But supporters respond that such problems are rare and a lot has recently been learned about how to prevent them.
The arguments go back and forth, but policymakers and governments aren't waiting for answers. Some countries, such as Germany, worried about a slippery slope toward unethical human experimentation, have already prohibited some types of stem cell research. Others, like the U.S., have imposed severe limits on government funding but have left the private sector to do what it wants. Still others, such as the U.K., China,
Korea, and Singapore, have set out to become the epicenters of stem cell research, providing money as well as ethical oversight to encourage the field within carefully drawn bounds.
In such varied political climates, scientists around the globe are racing to see which techniques will produce treatments soonest. Their approaches vary, but on one point, all seem to agree: How humanity handles its control over the mysteries of embryo development will say a lot about who we are and what we're becoming.
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Created By: Alberto Lopez
The compromise position that accepts the use and derivation of stem cells from spare in vitro fertilisation embryos but opposes the creation of embryos for these purposes is a very weak ethical position. This paper argues that whatever the basis is on which defenders of this viewpoint accord intrinsic value to the embryo, once they accept the creation and sacrifice of embryos to benefit infertile people with a child-wish, they do not have a sound moral argument to condemn the creation and sacrifice of embryos to benefit ill and injured people.
One of the central questions in the current stem cell debate is whether human embryonic stem cell research (ESCR) should be allowed, and, if so, under what constraints. Discussions about the regulation of ESCR are a stumbling block in developing stem cell policy. On the one hand there is a growing consensus that of all types of stem cell, the embryonic stem cells hold most promise for particular and important therapeutic and research aims.1 On the other hand, there is the controversial issue of “killing” human embryos through stem cell derivation.
Most of the participants in the stem cell debate, and especially those who are involved in policy making, opt for one of the possible compromise positions. They do not want to block human ESCR, but attempt to articulate at least some grounds for restraint in the use and derivation of embryonic stem cells (ESCs) in order to protect the embryo. I will focus on the compromise position that accepts the use and derivation of stem cells from spare in vitro fertilisation (IVF) embryos that are no longer needed in a procreation project, but opposes the creation of embryos solely for the purpose of stem cell derivation, the so-called “research embryos”. Many European advisory and regulatory bodies defend this position2 and a survey of public attitudes in nine European Union countries has shown that the majority of the participants in this research project also share this viewpoint.3
THE DISCARDED–CREATED DISTINCTION
I will argue that this position, which is grounded on the moral distinction between the use of spare embryos for research and therapy and the creation of research embryos—the so-called “discarded–created distinction”4 (from now on DCD)—is a very weak position. The main reason is the inconsistency between the “revealed” beliefs (that is, beliefs revealed by one’s acts or omissions) of its defenders and their professed beliefs. I will argue that whatever the basis is on which defenders of this viewpoint accord intrinsic value to the embryo, once they accept the creation and sacrifice of embryos to benefit infertile people with a child-wish, they do not have a sound reason to condemn the creation and sacrifice of embryos to benefit ill and injured people. Furthermore, I will show that an approach to ESCR which would also allow the creation of embryos solely for the derivation of stem cells would be more compatible with the revealed beliefs of those who currently defend DCD, and with widely shared values, in particular the alleviation of individual human suffering.
ARGUMENTS IN FAVOUR OF DERIVING STEM CELLS FROM SPARE EMBRYOS
Defenders of DCD find the use and derivation of stem cells from spare IVF embryos ethically acceptable but not the creation of research embryos for these purposes. The latter could be created by IVF but could also be the result of somatic cell nuclear transfer (SCNT)5 or embryo splitting. Let us examine the arguments underlying this position.
First we have to ask ourselves why the defenders of DCD want some human ESCR to go forward. Why do they accept the use and derivation of stem cells from spare IVF embryos?
Their motivation is grounded on one or a combination of the following widely accepted principles. Among these are the principle of freedom of research6 and the principle of progress,7 which state that restraints on scientific research are inherently offensive and generally unjustifiable8 and that we have a right to acquire new knowledge. The principles of beneficence and non-maleficence9 state that it is right to benefit people if we can, and wrong to harm them. ESCR could provide knowledge and therapies that would benefit thousands of people. Another principle referred to by defenders of DCD is the principle of proportionality,10 which states that the research has to serve an important purpose, such as a major health interest. In its recommendations on stem cell research, the US National Bioethics Advisory Commission (NBAC) expressed it this way: “In our view, the potential benefits of the research outweigh the harms of the embryos that are destroyed in the research process”.11 Another principle used to defend DCD is the principle of subsidiarity,12 which states that we have to choose the less contentious means of achieving the intended goal. Defenders of DCD apparently consider spare embryos as a necessary and also a sufficient stem cell source to reach the intended research goals. However, as John Harris has pointed out,13 the most important principle in defence of the use of spare embryos for research is the principle of waste avoidance, which states that, other things being equal, it must be better to make good use of something than to allow it to be wasted. With regard to ESCR the argument goes that spare embryos are going to be destroyed anyway because they are no longer needed in a procreation project, and that it is better to use them for a greater good—that is, for research and therapies. After all, it does not alter their final disposition.
Many people would agree that these are all valuable principles.14 Of course it is better to benefit people than to cause them harm, and of course the research has to serve important purposes and valuable things should not be wasted. None of these principles, however, suffices to justify DCD. They express why one wants some ESCR to go forward, and why one supports the use and derivation of stem cells from spare embryos, but it does not follow from these principles why one opposes the creation of research embryos. It is, for example, perfectly possible to argue against the waste of spare embryos while at the same time considering the creation of research embryos as ethically acceptable.
The relevant question here is what exactly makes it unethical to create embryos solely for research. Why is the use and derivation of embryonic stem cells from research embryos “ethically worse” than from spare embryos, and this to a degree that justifies the prohibition of the creation of research embryos?
ARGUMENTS AGAINST THE CREATION OF RESEARCH EMBRYOS
Instrumentalisation of the embryo
The principal objection of advocates of DCD to the creation of research embryos is that through this act the embryo is not treated with the appropriate respect such a form of human life is entitled to, because it is used merely as a means to an end. The underlying idea is that respect for human beings prevents the instrumental use of embryos,15 an act that, according to some, violates “human dignity”.16
Most advocates of DCD genuinely think the embryo deserves “special” respect. They consider it to be more valuable than any other human cell or tissue. However, by accepting the creation of spare embryos and their use for research, they apparently believe that its right to life can be weighed up against other values and interests and that human dignity is not violated per se by using early embryos as a means for research.
This raises the following question: if defenders of DCD do not consider the embryo as a person and accept the creation and sacrifice of embryos to help infertile people and their use for research, should they not also accept the creation and sacrifice of embryos to help to cure ill and injured people? After all, in both cases embryos are created as a means to alleviate human suffering and increase human wellbeing. Apparently, the argument of instrumentalisation alone does not suffice to justify DCD. It is not a logical consequence that one opposes the creation of research embryos. One can agree that the embryo is instrumentalised in an IVF treatment or in embryo research without disapproving of this.
Defenders of DCD reply to this that what makes the difference, in other words, what justifies DCD is that creating research embryos involves a “distinct kind of exploitative attitude, reflecting the thought that an embryo is something whose entire significance may be characterized by the external purposes for which we brought it into existence—the clearest possible case of treating something as a ‘mere means’”.17 A related argument was expressed by the NBAC in their 1999 report on stem cell research: “the act of creating an embryo for reproduction is respectful in a way that is commensurate with the moral status of embryos, while the act of creating an embryo for research is not”.18
But what is meant by “respectful in a way that is commensurate with the moral status of an embryo”? And why does the creation of research embryos involve a “distinctive kind of exploitative attitude”? Let us investigate these arguments and see whether they can justify DCD.
Creation of research embryos is not commensurate with the moral status of the embryo
Here we first have to ask ourselves which moral status defenders of DCD accord to the human embryo. The fact that they accept “destructive” embryo research shows that they do not consider the embryo as a person and even do not accord a moral status to it close to that of a person. Nevertheless, they believe it has intrinsic value—value independent of people’s intentions—and, therefore, merits “special respect”.
Some say the embryo has intrinsic value because it possesses human dignity.19 We should note here that there is no agreement on the meaning of “human dignity”. It is a vague expression that has to be clarified when used as an argument. Moreover, defenders of DCD apparently think that the fact that embryos possess human dignity does not imply that we have to protect them under all circumstances. After all, they accept the creation and sacrifice of spare IVF embryos. Consequently, the mere reference to human dignity cannot justify DCD.
Some say the embryo has to be protected because it has symbolic value. The European Society for Human Reproduction and Embryology, for example, stated that “the pre-implantation embryo is human and deserves our respect as a symbol of future human life”.20 In symbolic issues like this, however, it is not really the embryo that is at issue, but the impact of certain practices on our respect for human life. The relevant question here is whether the creation of research embryos will weaken our communal respect for human life in some way that IVF or the experimental use of spare embryos does not. There is nothing to suggest that this will be the case.21 Consequently, referring to symbolic value is not a sufficient argument to justify DCD. But taking into consideration the question of what the embryo is a symbol of brings us to a viewpoint on the embryo that most, if not all, defenders of DCD (implicitly) share. Therefore, this viewpoint is also more conducive to finding another valuable approach to ESCR that is more compatible with the revealed beliefs of defenders of DCD.
This widely shared viewpoint forms the basis of the Dutch Embryo Act22 and is expressed by the Health Council of the Netherlands as follows: “since it is human in origin and has the potential to develop into a human individual, the embryo has intrinsic value on the basis of which it deserves respect”.23 The French National Consultative Ethics Committee defends the position that “the embryo or foetus has the status of a potential human being who must command universal respect”.24 Both advisory bodies defend DCD and both believe the embryo has intrinsic value because it is a potential human being, a potential person. There exist, of course, various interpretations of the concept of “potentiality”, but it is not the aim of this paper to analyse these various views. I treat them elsewhere.25 The point to note is that whatever the criteria of potentiality are on which defenders of DCD attribute an intrinsic moral status to the embryo, they cannot explain the difference in moral status between spare and research embryos. Both have (or have not) the “intrinsic capacity” to develop into a person because of their genetic constitution and other characteristics of the embryo itself, and in both cases this capacity, this potentiality, will be frustrated when they are used for research.
Consequently, with regard to their intrinsic status—that is, their value in themselves, independent of people’s intentions—there is no moral difference between spare and research embryos. So what can it mean if one says that the creation of spare embryos is more commensurate with the moral status of embryos?
The following consideration may establish a large consensus among those who consider the creation and “killing” of spare embryos as ethically acceptable. Whatever the human emotions and opinions in relation to the embryo or the fetus may be, as soon as it becomes a question of the procreation project, the embryo is experienced as “the expected child” from the moment a woman knows she is pregnant or, in case of IVF, the embryo is created in vitro.26
The value people who undergo an IVF treatment ascribe to the in vitro embryo is variable and rises considerably as soon as the embryo is actually used in a parental project and decreases when it is no longer used in such a project. It is then referred to as “spare”, “surplus” or “supernumerary”. One of three options for the conceivers or the “owners” of spare embryos is to donate those of good quality to another couple (in which case they will not be considered as “spare” anymore, because they are again included in a procreation project), but most of them will be donated for research or will be discarded.27 Many people even forget that a number of their embryos are still frozen or do not even answer fertility clinics when asked what should be done with their surplus embryos.28 And in some countries with restrictive regulations, such as Germany and Austria, spare embryos can be cryopreserved for no more than one year. If, by then, they are not used for reproductive purposes by their conceivers, they must be destroyed.
Apparently, people who undergo IVF treatment and those who accept these practices believe that not every embryo’s intrinsic potential to become a person must be realised. The embryo as such is not the object of great value and almost absolute protection, but the embryo that is intended to lead to the birth of a desired child. Not only couples or individuals who create spare embryos, but also those who approve of this, apparently believe that the enhanced chance of a successful pregnancy and of fulfilling their wish for a child outweighs the moral value of each of the embryos. After all, they know beforehand that most of the created embryos will die, including some of “top quality”.
Defenders of DCD often justify the sacrifice of spare embryos by referring to the principle of double effect or to the “intention/foresight distinction”.29 They say that the embryos in a fertility treatment are created for the purpose of procreation and that the existence of spare embryos and their “destruction” is merely a non-intended side effect. However, if we apply the principle of double effect to the issue of spare embryos, the non-intended side effect is “making spare embryos” and not “research on spare embryos” or “discarding spare embryos”. Experimenting is merely a new action, which must be justified on another basis.30
The basis on which defenders of DCD justify research on spare embryos is a consequentialist argument, namely that the respect we have with regard to the human embryo as a potential person has to be balanced against other values and needs, namely the development of therapies. Whether or not the primary intention was the creation of a baby is irrelevant. They are responsible for the foreseeable results of their actions.31
But is the deliberate “destruction” for research of thousands of spare embryos—with the same intrinsic status as any other embryo—commensurate with their moral status as a potential person?
Yes, if this moral status is seen as variable and dependent on people’s intentions—for example, whether or not to include it in a parental project. Defenders of DCD apparently think that the potential of each created embryo to become a person should not be realised per se. Their protection can be weighed up against other values, such as the autonomy of the conceivers of the embryos who have to give their informed consent about the destination of their spare embryos (after all, an other option could be that each spare embryo should be adopted out).
Why cannot we then create embryos for stem cell research? After all, their intrinsic potential is also weighed up against other values and needs, namely the important research purposes.
Creation of embryos for stem cells entails a different kind of exploitation
Defenders of DCD defend their viewpoint by stating that the creation of embryos for stem cell research entails a “different kind of exploitation” because unlike a research embryo, a spare embryo has had a chance of becoming a person and we have therefore treated it with more respect than a research embryo.32 In their opinion, an embryo created for research is clearly being used merely as a means to an end, because it has no prospect of implantation, whereas at the time of creation the spare embryo had a prospect of implantation, even if, once not selected for implantation, it would have to be destroyed.33
Is this reasoning strong enough to justify DCD? Consider the following thought experiment: suppose we make research embryos, because it is the best way to reach the promising research goal. For the sake of argument, we might propose making a random selection of the same percentage of spare embryos that become a human from the research embryos and donate them to infertile couples who need a donor embryo. The percentage of “research embryos” that becomes a human would then be the same as that of the “spare embryos” that do so. Consequently, they would have had the same chance of becoming a person.34
If we would put this into practice, what results would we get? We know that about 3.5%35 of the created embryos in an IVF treatment become a person. To be more correct we would need to donate more than 3.5% of the research embryos to infertile couples, since only a fraction implants and goes to term. Suppose we would donate 10% of the research embryos. In the UK, the creation of research embryos has been allowed since 1990. Human Fertilisation and Embryology Authority (HFEA) figures show that between 1991 and 2000, a total of 925 747 embryos were created by IVF, of which only 118 were solely for research.36 Would defenders of DCD, bearing in their minds that in the same period 53 497 spare embryos were donated for research and 294 584 were destroyed, feel more comfortable if they knew we had donated 12 (10% of 118) of these research embryos to infertile couples for adoption?
What argument would supporters of DCD put forward against this proposal?
I think they would not have a strong argument. I think they even would not have a sound argument if we proposed to create research embryos and guarantee that one of them will become a person. After all, every embryo has had a chance of becoming a person and thus was treated as an end in itself. Without this proposal, none of them would have had a chance of existing at all. The survival chance of each embryo was not optimised because of other important values (helping ill and injured people). But this is also the case in IVF treatments, which put high risks on the embryos and decrease the intrinsic chances on survival of the embryos. (To protect women against multiple ovarian stimulation embryo sparing techniques are rarely used, and the freezing procedure puts high risk on embryos of good quality—50% of good quality embryos do not survive this procedure.)
The idea of taking a certain percentage out of research embryos might sound a bit absurd, but it helps to show that, apparently, defenders of DCD think that it is not that important to realise the intrinsic potential of each deliberately created embryo. It seems inconsistent that defenders of DCD are offended by the idea of the creation of research embryos as to oppose it despite the enormous benefits of the research for millions of people, while at the same time doing so little to optimise the intrinsic potential of embryos and instrumentalise them in IVF and research practices.
Moreover, the fact that defenders of DCD so strongly reject the making of “research embryos” is rather astonishing. As we all know, the IVF technique, the method of cryopreservation, intracytoplasmic sperm injection (ICSI), and other techniques were all developed through research on embryos that only came into being for the purposes of the experiment. So defenders of DCD consider this type of experiment to be unacceptable from an ethical standpoint, although the results of such experiments are applied without any qualms and in most countries have even become routine. The same is true for embryo experiments that are currently done to develop methods to improve, facilitate, or make reproduction possible, such as the development of better methods of in vitro culture and IVF, and of gamete and embryo storage.37
Embryos can only be instrumentalised for reproduction
One possible reply of defenders of DCD is that in the case of embryo experimentation for the improvement of, for example, culture conditions or other IVF procedures, embryos are instrumentalised for reproductive purposes, and this is justified because it is the embryo’s “function” to be used for reproduction.38 I think this argument is very weak, primarily because it does not take into account what is in the interest of the embryo (or of the person who will result from the embryo). If I were an embryo I would prefer to be in the lottery proposed by the thought experiment, to being used in “destructive” research to improve culture conditions in the context of an IVF treatment.39 Moreover, the embryos are not always instrumentalised for reproductive purposes. They are also—and often solely—used as a means to other ends. Spare embryos are created to protect women undergoing fertility treatment against the risks of hormone treatment, and research embryos are used in investigations that aim at increasing safety and efficiency in freezing procedures.
Harm/omit to benefit
Another argument defenders of DCD use is that embryos can be instrumentalised for reproduction because it prevents harm to actual infertile women who undergo fertility treatments, while, in the case of stem cell research, embryos are sacrificed only for the benefit of unidentifiable people who might be benefited by stem cell therapy, but whom we do not harm now by not doing so. Infertile women will be made worse off than they would otherwise be, whereas sick people will be made better off than they would otherwise be. The underlying principle is that the obligation not to harm is stronger than the obligation to benefit.40 People who bring forward this argument, however, depart from the idea that infertile people will make use of fertility treatments anyhow. This paper, however, investigates the inconsistency between normative stands of defenders of DCD. Consequently, one has to depart from their beliefs and attitudes, namely the fact that they accept the creation and sacrifice of embryos to help infertile people—that is, for their benefit. After all, another option open for them is to oppose IVF treatments because embryos should not be created and sacrificed for these purposes. They would not harm these people; they would omit to benefit them. Their argument that embryos may not be instrumentalised for the benefit of people clearly fails.41 If defenders of DCD oppose the creation of embryos for stem cell research, they have to argue why it is more important to benefit people with a child-wish, than to benefit ill and injured people, and this to the extent that justifies the prohibition of the latter. I do not think they have a sound argument.
A VIEW COMPATIBLE WITH THE BELIEFS OF DEFENDERS OF DCD AND WITH WIDELY SHARED VALUES
I think that a view on ESCR that also accepts the creation of research embryos for stem cell derivation is compatible with the actual beliefs of those who now defend DCD. Defenders of DCD believe that an embryo merits special respect because of its intrinsic value, but that its potential to become a person can be weighed up against other values. There are forms of respect and deference which are less absolute and which can have gradations. The respect one has for an entity does not exclude it, provided that a meaningful argument is presented, from being used as a resource for a goal which is believed to be important. (Research on cadavers, with the informed consent of the party in question and on the condition of respectful treatment, is entirely legitimate in most countries.) Early embryos are respected by ensuring that they are used with care in research that incorporates substantive values such as the alleviation of human suffering (in accordance with the principles of beneficence and proportionality), by guaranteeing that their potential will not be wasted (in accordance with the principle of waste avoidance) and that they will only be used if there are no less contentious means of achieving the intended goal (in accordance with the subsidiarity principle). Well regulated stem cell research that uses embryos solely created for these purposes can be consistent with these widely shared values.
I have argued that whatever the basis is on which defenders of DCD accord intrinsic value to the embryo, once they accept the creation and sacrifice of embryos to benefit infertile people with a child-wish, they do not have a sound reason to condemn the creation and sacrifice of embryos to benefit ill and injured people who could be helped by stem cell therapies. If we consider the revealed beliefs of advocates of DCD, it seems that in general many people have respect and concern for some kind of protection for embryos, but that these feelings can change and depend on whether or not an embryo is involved in a parental project. In other words, the value they accord to the embryo is variable and depends also on criteria external to the embryo and related to intentions of people. Creating embryos for their stem cells is commensurate with the variable moral status defenders of DCD actually accord to the embryo, and, as is the case with spare embryos, these research embryos would be instrumentalised or exploited for the benefit of other people. An approach to ESCR that would also allow the creation of embryos solely for the derivation of stem cells would be compatible with the revealed beliefs of those who currently defend DCD, and with widely shared values, in particular the alleviation of individual human suffering.
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Created By: Alberto Lopez
In the past 5 years, China has increased its efforts in the field of stem cell research and practice. Basic research mainly focuses on bone marrow and embryonic stem cells. Clinical applications of stem cells in the treatment of acute heart failure, acute liver failure and lower limb ischaemia have been reported by many hospitals. China enacted its ‘Ethical Guidelines for Human Embryonic Stem Cell Research’ in 2003. At present, China has the most liberal and favourable environments for human embryonic stem cell research.
stem cell differentiation somatic nuclear transfer
Stem cells are defined as a cell population capable of self-renewal, proliferation and differentiation. Stem cells are usually classified into two different types during the development of the organism: embryonic stem cells (ESCs) and adult stem cells. ESCs are derived from the inner cell mass of blastocysts and continue their development by segregating into the hypoblast and epiblast
. These layers further segregate into the pluripotent primary germ layers: ectoderm, mesoderm and endoderm. Adult stem cells are represented in many tissues of the adult organism. Their physiological function consists of renewing or restoration of the differentiated cells during the lifespan of the organism. The majority of regional adult stem cells differentiate into a limited number of cell types. For example, neural stem cells give rise to cells of the nervous system and haemopoietic stem cells to blood cells.
The beginnings of stem cell research in China may be traced back to 1963, 34 years before Dolly the sheep was introduced to the world, when the late embryologist Dizhou Tong transferred the DNA from a cell of a male Asian carp to an egg of a female Asian carp, and produced the world's first cloned fish (Tong et al. 1963).
In previous decades, researchers had cloned micro-organisms and nematodes, as well as amphibians. But before Tong, nobody had ever managed to clone such a complex organism. To all appearances, the experiment was entirely successful. The cloned carp even sired a baby carp. After 10 years, Tong inserted the DNA of an Asian carp into an egg of a European crucian carp, a related species, and created the first interspecies clone (Tong et al. 1973). Based on this pioneering research, Chinese scientists developed fish-breeding techniques so powerful that the nation now produces more than half of the world's aquaculture harvest. But few, if any, Western scientists knew of Tong's achievements, partly because his work was published in a Chinese journal, Acta Zoologica Sinica, which did not have an English-language abstract, a common problem in non-Western scientific periodicals. In any case, Tong performed his experiments not to study cloning per se but to investigate the interactions between DNA and the egg containing it. Unfortunately, Tong's pioneering work was interrupted prematurely by the Chinese Cultural Revolution.
Presently, no country is pursuing the field more aggressively than China. In China, research on both ESCs and adult stem cells is supported by governmental funds. Stem cell research fits the Chinese Ministry of Science and Technology's ambitious plans to vault the country to the top of the research ranks.
China has pumped money into this area through multiple sources: cities, provincial governments and two special national research initiatives (863 and 973 plans). In this review, we will give a brief introduction to the stem cell research based on published reports both in English and Chinese.
2. Human embryonic stem cells
The Chinese government allows research on human embryos and cloning to continue for therapeutic purposes. In 2001, the two national committees on medical ethics and bioethics, the Beijing Ministry of Health Medical Ethics Committee and the Southern Chinese Human Genome Research Centre Ethical, Legal, and Social Issues Committee (ELSI), proposed ethical guidelines on human embryonic stem cell (hESC) research. The suggested regulations ban activities that most nations condemn such as reproductive human cloning and the buying and selling of human embryos for commercial purposes. They also proposed the establishment of a new organization to centralize the ethical management of stem cell research in China, a responsibility that is currently divided between the Ministry of Health, the Ministry of Science and Technology and the local ethics committees. Subsequently, the ‘Four Nos’ were proposed for the scientific community: a single-sentence directive promulgated by the Ministry of Health in November, 2002: ‘Under no situation, under no circumstances, will human reproductive cloning experiments be 1) endorsed, 2) permitted, 3) supported, or 4) accepted’. On 24 December 2003, Ethical Guidelines for Research on Human Embryonic Stem Cells were enacted by the Ministry of Science and Technology and the Ministry of Health of China. The hESCs described in the guidelines include stem cells derived from donated human embryos, those originated from germ cells and those obtained from somatic cell nuclear transfer. It again clearly states that any research aiming at human reproductive cloning and hybridizing human germ cells with germ cells of any other species shall be prohibited.
He et al. (2002) established the first hESC lines in China. Fourteen human oocytes obtained from a volunteer were fertilized in vitro. Four of the morulae formed from the fertilized oocytes were frozen and five continued to develop into blastocysts. The pellucid zones of the five blastocysts were removed and their inner cell masses taken out and inoculated onto a feeder layer of mouse embryonic fibroblasts. The cell clones formed from the three surviving inner cell masses were selected, dispersed and inoculated onto feeder layers to produce more cell clones. When multiple clones were produced, they were dissociated with dispase into smaller cell masses, which were inoculated onto a new feeder layer again. Out of nine fertilized oocytes, five developed into blastocysts. Three hESC cell lines were established from the inner cell masses, namely CHE1, CHE2 and CHE3. These stem cells remained undifferentiated after subculturing for seven months. The surface markers of human stem cells, SSEA-4, SSEA-3, TRA-1-60 and GCTM-2, were positive at passages 25, 30 and 40 for CHE3, and at passages 21, 22 and 30 for CHE1 and CHE2. All cell lines stably retained a normal karyotype. After routine passage for five months, cells from three cell lines were inoculated onto the legs of severe combined immunodeficiency mice subcutaneously to observe teratoma formation. Six weeks after inoculation of the three cell lines, teratomas were formed in all mice. Histological examination revealed that they contained various tissues derived from all the three embryonic germ layers. Thus, He et al. (2002) established the first hESC lines in China.
The researchers led by Sheng of the Shanghai Second Medical University have reprogrammed human cells by fusing them with rabbit eggs emptied of their genetic material (Chen et al. 2003a). They extracted stem cells from the resulting embryos and derived ESCs by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at the ages of 5, 42, 52 and 60 years, and nuclear transfer embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells were human based on karyotype, isogenicity, in situ hybridization, polymerase chain reaction (PCR) and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintained the capability for sustained growth in an undifferentiated state and formed embryoid bodies, which, on further induction, gave rise to cell types such as neuron and muscle, as well as mixed cell populations that expressed markers representative of all the three germ layers. Thus, ntES cells derived from human somatic cells by nuclear transfer to rabbit eggs retain phenotypes similar to those of conventional hESCs, including the ability to undergo multilineage cellular differentiation. Sheng's group also established four hESC lines (Fang et al. 2005a).
A lot of effort has been put into the regulation of ESC proliferation and differentiation. Nanog, an NK-2-type homeodomain gene, has been proposed to play a key role in maintaining stem cell pluripotency. Pei and co-workers at the Institute of Pharmacology, Tsinghua University, showed that Nanog behaves as a transcription activator with two unusually strong activation domains embedded in its C-terminus. They identified two transactivators by employing the Gal4 DNA-binding domain fusion and reporter system and named them WR and CD2. CD2 contains no obvious structural motif, whereas the WR or Trp repeat contains 10 pentapeptide repeats starting with a Trp in each unit. Deletion of both WR and CD2 from Nanog completely eliminated its transactivation function (Pan & Pei 2004). They also identified and characterized (195)RKRKR as the nuclear localization signal responsible for Oct4 localization and required for the transactivation of its target genes in ESC (Pan et al. 2004). Xu et al. (2004) at the Shanghai Second Medical University described a novel murine ubiquitin ligase, Wwp2, that specifically interacts with Oct-4 and promotes its ubiquitination both in vivo and in vitro. Remarkably, the expression of a catalytically inactive point mutant of Wwp2 abolished Oct-4 ubiquitination. Moreover, Wwp2 promoted Oct-4 degradation in the presence of overexpressed ubiquitin. Fusion of a single ubiquitin to Oct-4 inactivated it transcriptionally in a heterologous Oct-4-driven reporter system. Furthermore, overexpression of Wwp2 in ESCs significantly reduced Oct-4 transcriptional activities. Collectively, they demonstrate for the first time that Oct-4 can be post-translationally modified by ubiquitination and that this modification dramatically suppresses its transcriptional activity. Their results open up a new avenue to understanding how Oct-4 defines the fate of ESCs.
3. Pluripotent stem cell
Although the potential applications of hESCs and therapeutic cloning hold promise of medical benefits, these technologies have posed profound ethical issues because they necessitate the destruction of human embryos. We should always keep in mind that science and technology can never be independent of the criterion of morality, since technology exists for man. Hence, a fundamental point in the issues of embryonic stem cells is the concept of the moral status of human embryos. A lot of people have held that human life begins at the moment of conception and therefore, have defended the dignity, inviolable right to life and integrity of human embryos. Some governments have opposed limitations on hESC research. Therefore, it is of great importance for scientists to find adult stem cells that have a similar differentiation potential to embryonic stem cells.
Researchers led by Zhao at the Chinese Academy of Medical Sciences reported that a cell population derived from human foetal bone marrow, termed Flk1+CD31−CD34− stem cells, could differentiate, not only into osteogenic, adipogenic and endothelial lineages, but also hepatocyte-like, neural and erythroid cells at the single-cell level (Fang et al. 2003, 2004).
Zhao et al. used cells from a single colony, which precluded the possibility of contamination by different stem cells. Based on their research, they suppose that there is a subfraction of the adult stem cell population which exists in a number of tissues beyond embryo development. These stem cells can form tissues of different germ layer lineages, differing from common adult stem cells that only form tissues within a particular germ layer lineage. However, they differ from ESCs in that they gradually lose some differentiation potential during gestation and adopt special phenotypes or molecular markers once within a certain kind of tissue. They remain in some/all tissues and organs during gestation and can give rise to different kinds of pluripotent stem cells, contributing to self-repair and self-renewal. They can provide cells not only for the damaged tissues in which they reside, but also for remote tissues by migration triggered by proinflammatory cytokines or growth factors.
To test the hypothesis that post-embryonic subtotipotent stem cells exist in most human tissues, numerous experiments have been carried out in the lab. Zhao and co-workers have chosen foetuses as a source of adult stem cells. They believe that the foetus may contain the most primitive stem cells and will make the isolation of cells easier. In China, given that research on spontaneously aborted human foetuses is lawful upon receiving written consent from the donor, a lot of researchers are using human foetuses as a source of cells (Tang 2003).
They found that Flk1+CD31−CD34− cells isolated from foetal bone marrow have characteristics of haemangioblasts, i.e. progenitors of endothelial and haemopoietic cells (Guo et al. 2003). They showed that on extra-cellular matrix (ECM) gel, Flk1+CD31−CD34− cells could grow into a vascular structure that was positive for CD31 and vWF. When the angiogenesis inhibitor suramin was added, formation of a vascular structure was blocked. In addition, Flk1+CD31−CD34− cells cultured in haemopoietic conditions could differentiate into haemopoietic cells which expressed GATA-1, -2, gamma- and beta-globin genes. After being replated in methylcellulose medium, they formed typical erythroid colonies. The results suggested that these Flk1+CD31−CD34− cells bear characteristics of haemangioblasts after the embryo stage. These findings were further confirmed in chronic myelogenous leukaemia (CML; Fang et al. 2005b). They isolated Flk1+ cells carrying the BCR/ABL fusion gene from the bone marrow of 17 Philadelphia chromosome-positive (Ph+) patients with CML and found that they could differentiate into malignant blood cells and phenotypically defined endothelial cells at the single-cell level. These findings provide direct evidence, for the first time, that rearrangement of the BCR/ABL gene might happen at or even before the level of haemangioblastic progenitor cells, thus resulting in the detection of the BCR/ABL fusion gene in both blood and endothelial cells.
The potential use of Flk1+CD34− stem cells in tissue regeneration was demonstrated in several models. First, when fluorescence-labelled Flk1+CD34− stem cells of BALB/c mice (H-2Kd, white) were transplanted into lethally irradiated C57BL/6 mice (H-2Kb, black), donor cells could migrate and take residency at the skin, which was confirmed by Y chromosome-specific PCR and Southern blot. The recipient mice grew white hairs after approximately 40 days. Immunochemistry staining and RT-PCR demonstrated that skin tissue within the white hair regions was largely composed of donor-derived H-2Kd cells, including stem cells and committed cells. Furthermore, most skin cells cultured from white hair skin originated from the donor. Thus, these findings provide direct evidence that bone marrow-derived cells can give rise to functional skin cells and regenerate skin tissue (Deng et al. 2005a,b). Second, Flk1+CD34− stem cells from adipose tissue were shown to have characteristics of endothelial progenitor cells. In vitro, these cells expressed endothelial markers when cultured with vascular endothelial growth factor (VEGF). In vivo, these cells can differentiate into endothelial cells that contributed to neoangiogenesis in the hind limb ischaemia models, suggesting they may be a potential source of endothelial cells for cellular pro-angiogenic therapies (Cao et al. 2005).
Zhao and co-workers also demonstrated that Flk1+CD34− stem cells can modulate immune function. Consistent with the finding that Flk1+CD34− stem cells have the characteristics of haemangioblasts, they showed that these cells could induce stable mixed chimerism and donor-specific graft tolerance when they were transplanted into lethally irradiated mice. FACS analysis revealed that more than 5% of donor-derived CD3+ cells were detected in splenocytes of recipient mice. Long-term survival of donor-type skin grafts was observed. Mixed lymphocyte reaction (MLR) and mitogen proliferative assays showed that the recipient mice had low immune response to donor cells but retained a normal ConA-induced proliferative response compared with normal mice (Deng et al. 2004). Further studies showed that Flk1+CD34− stem cells could inhibit the upregulation of CD1a, CD40, CD80, CD86 and HLA-DR during dendritic cell differentiation and prevent an increase of CD40, CD86 and CD83 expression during dendritic cell maturation. Flk1+CD34− stem cells interfered with endocytosis of dendritic cells and decreased their capacity to secret IL-12 and activate alloreactive T cells (Zhang et al. 2004). More importantly, Flk1+CD34− stem cells from BALB/c mice had inhibitory effects on BXSB mice T-lymphocyte proliferation. Furthermore, Flk1+CD34− stem cells had inhibitory effects on the proliferation, activation and IgG secretion of B lymphocytes. In addition, BALB/c Flk1+CD34− stem cells had an enhancing effect on CD40 expression and inhibitory effects on CD40 ligand (CD40L) ectopic hyperexpression on B cells from BXSB mice. In further studies, they found that transplantation of Flk1+CD34− stem cells from BALB/c mice alleviated the symptoms of BXSB mice. As the BXSB mouse is considered an experimental model for human systemic lupus erythematosus, these findings may have important implications (Deng et al. 2005a,b).
Li's group at the Peking University Stem Cell Centre observed that cells isolated from human gonadal ridges and mesenteries expressed pluripotent markers and formed embryonic bodies. However, these cells did not proliferate well and tended to differentiate spontaneously into neuron-like cells under their culture conditions (Pan et al. 2005). It is obvious that more effort is needed to reproduce the perfect growth conditions for embryonic gonadal cells in order to maintain them long term in culture. They also isolated mesenchymal stem cells (MSC) from umbilical-cord blood (UCB). They showed that MSC-like cells could be isolated and expanded from 16- to 26-week foetal blood, but were not acquired efficiently from full-term infants' UCB. MSC-like cells shared a similar phenotype with bone-marrow MSC: CD34−CD45−CD44+CD71+CD90+CD105+. They could be induced to differentiate into osteogenic, adipogenic and neural lineage cells. Single-cell clones also showed similar phenotypes and differentiation ability. These results suggest that MSC are abundant in early foetal blood but not in term UCB (Yu et al. 2004).
4. Application of adult stem cells
The most significant achievements made in China can be recognised by the quick transfer of the basic research to clinical application.
Zhao's group are in collaboration with the National Institute for the Control of Pharmaceutical and Biological Products. Based on the principles of safety, reliability, stability and controllability, they collectively worked out a highly standard and stringent procedure for Flk1+CD31−CD34− stem cell culture and assessment. Preclinical studies on monkeys have showed that this approach could greatly promote the survival of newly transplanted stem cells and reconstitution of the haemopoietic system and significantly reduce the degree of graft versus host disease. As a ‘new cell drug’, the Flk1+CD31−CD34− stem cell clinical protocol won approval from the State Food and Drug Administration of China in 2004. Now Zhao's group is running China's first officially approved stem cell therapy for patients with leukaemia and other severe diseases. They showed that cotransplantation of HLA-identical sibling culture-expanded Flk1+CD31−CD34− stem cells with an HLA-identical sibling hematopoietic stem cell (HSC) transplant is feasible and seems to be safe, without immediate or late stem cell-associated toxicities. The number of patients included in phase I clinical trials did not allow a demonstration of the effectiveness of the treatment. However, the result of the present study is encouraging and phase II clinical trials will soon be started.
In acute myocardial infarction, the flow of blood from a blood vessel in the heart is blocked, the cardiac muscle receives insufficient oxygen and the heart tissue dies. In many cases, supply of blood to the deadened portion of the heart can be restored via the so-called balloon technique. But the heart suffers permanent damage, primarily to the left ventricle. Researchers in Nanjing have tested the administration of bone marrow stem cells in patients stricken with acute myocardial infarction. Sixty-nine patients who underwent primary percutaneous coronary intervention within 12 hours of the onset of acute myocardial infarction were randomized to receive intracoronary injection of autologous bone-marrow MSCs or saline. Several imaging techniques demonstrated that bone-marrow MSCs significantly improved left ventricular function. For example, the proportion with a functional defect decreased significantly in the MSC group after three months. Wall movement velocity over the infracted region increased significantly in the MSC group, but not in the control. The left ventricular ejection fraction in the MSC group increased significantly three months after transplantation compared with pre-implantation and with that of the control group at three months post-injection. Single-photon emission-computed tomography scan results showed that the perfusion defect had improved significantly in the MSC group at the three-month follow-up compared with that of the control group (Chen et al. 2004). Similar MSC therapy for heart infarction was carried out in other hospitals (Chen et al. 2003b; Ruan et al. 2005; Zhang et al. 2005).
Allogeneic liver transplantation remains the only effective treatment available to patients with liver failure. Owing to a serious shortage of liver donors, an alternative therapeutic approach is urgently needed. Transplantation of hepatocytes derived from adult or foetal livers is not a candidate for the alternative treatment because the source of such cells is limited to human liver at present. Recently, extrahepatic sources of cells have been explored for use in cell therapy. Yao et al. (2005) reported the treatment of patients with liver failure by the transplantation of autologous bone-marrow stem cells. Bone marrow was harvested (30–50 ml) from patients in the transplant group and infused into the liver of patients via the hepatic artery. At different time points (one, two, four or eight weeks post-transplantation), alanine aminotransferase (ALT), total bilirubin (TBIL), direct bilirubin (DBIL), albumin (ALB) and prothrombin time activity (PTA) were measured, and the survival rate and improvement of symptoms recorded. After transplantation of bone-marrow stem cells, the liver function of patients improved. Eight weeks after transplantation, ALT reduced from 181.71 to 72.1 μmol l−1, TBIL from 153.1 to 80.2 μmol l−1, DBIL from 74.1 to 40.5 μmol l−1, ALB increased from 26.5 to 31.5 μmol l−1 and PTA from 28.23 to 50.1%, respectively. The survival rate of the transplant group was higher than that of the control. Eight weeks after transplantation, ascites decreased in 10 cases (50%), appetite improved in 15 cases (75%) and abdomen distention ameliorated in 9 cases (45%). No serious side effects were observed in 20 patients with bone-marrow stem cell transplantation (Yao et al. 2005).
Diabetes is a common chronic disease with significant morbidity and mortality. One devastating complication of diabetes is peripheral arterial disease including critical limb ischaemia, which may result in limb loss. There is no available permanent cure for diabetic limb ischaemia at present. In response to tissue injury and remodelling, neovascularization usually occurs via the proliferation and migration of endothelial cells from pre-existing vasculature. The endothelial progenitor cells (EPCs) resident within the bone marrow and peripheral blood can also contribute to injury- and pathology-induced neovascularization. Therefore, therapeutic angiogenesis induced by transplantation of functional EPCs into ischaemic tissues may represent a novel approach for diabetic patients with limb ischaemia. Yang and co-workers reported a simple and effective therapeutic approach for diabetic limb ischaemia by autologous transplantation of granulocyte–macrophage colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSCs). In total, 62 patients with 34 cases of diabetic foot and 28 cases of various lower extremity ischaemic disorders received recombinant human G-CSF at 450–600 μg d−1 by hypodermic injection for 5 days to mobilize stem cells. On the 6th day, PBSCs were collected. The PBSCs were injected into the ischaemic lower extremity and foot intramuscularly. The clinical and laboratory findings were monitored from the first day to the twenty-fourth week. In 62 patients with PBSC transplantation, 54 cases (87.1%) were found to be free of severe pain after 7 to 30 days. An improvement in foot coolness and ulceration was observed in 56 patients (90.3%) after 7 to 30 days and in 16 cases (40.0%) after 4 to 16 weeks, respectively. Ankle/brachial index increased in 12 cases (34.3%) and transcutaneous PO2 (TcPO2) in 26 cases (42.3%). Digital subtraction angiographic scores indicated the formation of new collateral vessels. Adverse effects were only observed in two patients during the process of stem cell mobilization (Yang et al. 2005a). Other researchers have also reported their findings (Huang et al. 2004; Yang et al. 2005b).
Spinal cord injury (SCI)-induced paralysis is related to the fact that axons in adult central nervous system (CNS) do not regenerate after injury. Several factors may account for the normal regenerative failure seen in the adult CNS. Implantation of various types of tissue, such as peripheral nerve grafts, ESCs, macrophages and olfactory ensheathing cells (OECs), into and around the site of SCI have been shown to contribute to spontaneous axonal regeneration following injury; implanted OECs seem to have the most promising effect on it (Li et al. 1997). The olfactory system is unique in that it supports continuous growth of axons from the olfactory epithelium into the CNS throughout the lifetime of the individual. The olfactory system's capacity for axonal extension and target-specific synaptic interaction has been attributed to the growth-promoting function of ensheathing cells. Huang et al. (2003) reported the restoration of function after SCI in patients of different ages who underwent intraspinal transplantation of OECs. In their study, 171 SCI patients were included. In all these SCI patients, the lesions were injected with OECs at the time of operation. Spinal cord function was assessed based on the American Spinal Injury Association (ASIA) classification system before and two-to-eight weeks after OEC transplantation. After surgery, the motor scores increased by 5.2±4.8, 8.6±8.0, 8.3±8.8, 5.7±7.3 and 8.2±7.6 in five age groups; light touch scores increased by 13.9±8.1, 15.5±14.3, 12.0±14.4, 14.1±18.5 and 24.8±25.3; and pin prick scores increased by 11.1±7.9, 17.2±14.3, 13.2±11.8, 13.6±13.9 and 25.4±24.3, respectively. OEC transplantation can improve the neurological function of spinal cord of SCI patients regardless of their ages. Further research into the long-term outcomes of the treatment will be required (Huang et al. 2003).
Stem cell research in China is attracting more and more attention from around the world. Many of the top labs are planning to submit their most promising results to international research journals. This may consolidate the number of labs working in the field as funding institutions concentrate their resources on the few labs that produce results. While the Chinese government has issued guidelines for hESC research, some scientists and ethicists also expect guidelines for the clinical use of adult stem cells. However, no laws or enforcement can be realistically expected in the short term. Presently, only Zhao's group at the Chinese Academy of Medical Sciences and Peking Union Medical College, China, has been granted phase I clinical trial approval for the use of MSCs in cotransplantation of haemopoietic stem cells for leukaemia patients.
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