Production of insulin

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Certain human proteins, such as insulin, are sometimes needed on demand. Unfortunately, our bodies can not produce them on the spot. This can be very dangerous for some people, like those with diabetes. Diabetics do not produce enough insulin, and therefore they need a way to obtain new insulin. Through genetic engineering, insulin can be created to be ready when needed.
Genes can be transplanted from one organism to another through the use of genetic engineering. The genes can then be combined with genes of the second organism. This is used to move human genes into mammals such as goats and sheep so that the animals can then produce great quantities of human proteins, such as insulin. Microorganisms are also used to help produce human proteins. This is useful so that there will always be a supply of insulin for people with diabetes. The proceduce of transplanting genes is shown below using a bacterium.

Production of organ

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A major problem that exists in the United States today is the unavailability of organs for necessary transplants. However, with the use of a new technique, man-made tissues or organs, known as "neo-organs" are being created. This would increase the supply of organs and therefore save many lives.

There are two procedures used to fix a wound or an organ that needs to be regenerated. The first procedure creates new tissue and involves a tissue engineer injecting a given molecule, such as a growth factor, into the wound or organ. The patient's own cells are caused to migrate into the wound site, change into the correct cell type, and regenerate the tissue. The second procedure creates new organs and involves placing cells into three-dimensional scaffolds of biodegradable polymers. The whole structure of cells and scaffolding is placed into the wound site. The cells then replicate, reorganize and form new tissue. At the same time, the artificial scaffolding breaks down, leaving a totally natural product, a neo-organ.

Production of insulin

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Certain human proteins, such as insulin, are sometimes needed on demand. Unfortunately, our bodies can not produce them on the spot. This can be very dangerous for some people, like those with diabetes. Diabetics do not produce enough insulin, and therefore they need a way to obtain new insulin. Through genetic engineering, insulin can be created to be ready when needed.
Genes can be transplanted from one organism to another through the use of genetic engineering. The genes can then be combined with genes of the second organism. This is used to move human genes into mammals such as goats and sheep so that the animals can then produce great quantities of human proteins, such as insulin. Microorganisms are also used to help produce human proteins. This is useful so that there will always be a supply of insulin for people with diabetes. The proceduce of transplanting genes is shown below using a bacterium.

Genetic Engineering

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Genetic engineering, recombinant DNA technology, genetic modification/manipulation (GM) and gene splicing are terms that apply to the direct manipulation of an organism's genes.[1] Genetic engineering is different from traditional breeding, where the organism's genes are manipulated indirectly. Genetic engineering uses the techniques of molecular cloning and transformation to alter the structure and characteristics of genes directly. Genetic engineering techniques have found some successes in numerous applications. Some examples are in improving crop technology, the manufacture of synthetic human insulin through the use of modified bacteria, the manufacture of erythropoietin in hamster ovary cells, and the production of new types of experimental mice such as the oncomouse (cancer mouse) for research.

Histery of GE

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Ancient History
Selective breeding has been going on for countless generations. In fact, it is even mentioned in the Bible (Genesis 30:25 - 43). In the account, Jacob was employed as a shepherd under his father-in-law Laban. Instead of receiving wages, Jacob received the black, streaked, and spotted sheep, and Laban kept all the white sheep. Jacob craftily arranged for his black sheep to mate with Laban's white sheep, producing streaked and spotted sheep. Jacob did so well with this scheme that Laban's family began to get mad at Jacob, and he eventually had to leave.

Difficulties
Selective breeding is effective enough if the goal is to maintain or gradually improve a group of animals. Over the decades, selective breeding has brought us improved strains of cattle and specialized breeds of dogs. However, these advances have taken hundreds of years to effect. In addition to the time concerns, it is often impossible to know which traits will be transferred to the offspring.

Limits
Selective breeding is a long, tedious process that has its limits. It is impossible through selective breeding to mix traits from two totally different species. If a junkyard owner wanted a guard dog that could squirt ink like an octopus, he would be unable to create such an animal. It is physically impossible, because the genetics of life are such that traits from two different organisms cannot be mixed. That is where genetic engineering comes in.

The Progress
Modern genetic engineering began in 1973 when Herbert Boyer and Stanley Cohen used enzymes to cut a bacteria plasmid and insert another strand of DNA in the gap. Both bits of DNA were from the same type of bacteria, but this milestone, the invention of recombinant DNA technology, offered a window into the previously impossible -- the mixing of traits between totally dissimilar organisms. To prove that this was possible, Cohen and Boyer used the same process to put a bit of frog DNA into a bacteria.
Since 1973, this technology has been made more controllable by the discovery of new enzymes to cut the DNA differently and by mapping the genetic code of different organisms. Now that we have a better idea of what part of the genetic code does what, we have been able to make bacteria that produce human insulin for diabetics (previously came from livestock), as well as EPO for people on kidney dialysis (previously came from urine of people in third world countries with ringworm).
In 1990, a young child with an extremely poor immune system recieved genetic therapy. Some of her white blood cells were genetically manipulated and re-introduced into her bloodstream while she watched Sesame Street. These new cells have taken over for the original, weak white cells, and her immune system now works properly. Although relatively few people have had their cells genetically altered, these advances have made the prospect of mainstream genetic medicine seem more likely.

Advatage and Disadvantage of GE

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Genetic Engineering Advantages & Disadvantages
- Genetics and Evolution

During the latter stage stages of the 20th century, man harnessed the power of the atom, and not long after, soon realised the power of genes. Genetic engineering is going to become a very mainstream part of our lives sooner or later, because there are so many possibilities advantages (and disadvantages) involved. Here are just some of the advantages :

* Disease could be prevented by detecting people/plants/animals that are genetically prone to certain hereditary diseases, and preparing for the inevitable. Also, infectious diseases can be treated by implanting genes that code for antiviral proteins specific to each antigen.
* Animals and plants can be 'tailor made' to show desirable characteristics. Genes could also be manipulated in trees for example, to absorb more CO2 and reduce the threat of global warming.
* Genetic Engineering could increase genetic diversity, and produce more variant alleles which could also be crossed over and implanted into other species. It is possible to alter the genetics of wheat plants to grow insulin for example.

Of course there are two sides to the coin, here are some possible eventualities and disadvantages.

* Nature is an extremely complex inter-related chain consisting of many species linked in the food chain. Some scientists believe that introducing genetically modified genes may have an irreversible effect with consequences yet unknown.
* Genetic engineering borderlines on many moral issues, particularly involving religion, which questions whether man has the right to manipulate the laws and course of nature.

Genetic engineering may be one of the greatest breakthroughs in recent history alongside the discovery of the atom and space flight, however, with the above eventualities and facts above in hand, governments have produced legislation to control what sort of experiments are done involving genetic engineering. In the UK there are strict laws prohibiting any experiments involving the cloning of humans. However, over the years here are some of the experimental 'breakthroughs' made possible by genetic engineering.

* At the Roslin Institute in Scotland, scientists successfully cloned an exact copy of a sheep, named 'Dolly'. This was the first successful cloning of an animal, and most likely the first occurrence of two organisms being genetically identical. Note : Recently the sheep's health has deteriorated detrimentally
* Scientists successfully manipulated the genetic sequence of a rat to grow a human ear on its back. (Unusual, but for the purpose of reproducing human organs for medical purposes)
* Most controversially, and maybe due to more liberal laws, an American scientist is currently conducting tests to clone himself.

Genetic engineering has been impossible until recent times due to the complex and microscopic nature of DNA and its component nucleotides. Through progressive studies, more and more in this area is being made possible, with the above examples only showing some of the potential that genetic engineering shows.

For us to understand chromosomes and DNA more clearly, they can be mapped for future reference. More simplistic organisms such as fruit fly (Drosophila) have been chromosome mapped due to their simplistic nature meaning they will require less genes to operate. At present, a task named the Human Genome Project is mapping the human genome, and should be completed in the next ten years.

The process of genetic engineering involves splicing an area of a chromosome, a gene, that controls a certain characteristic of the body. The enzyme endonuclease is used to split a DNA sequence and split the gene from the rest of the chromosome. For example, this gene may be programmed to produce an antiviral protein. This gene is removed and can be placed into another organism. For example, it can be placed into a bacteria, where it is sealed into the DNA chain using ligase. When the chromosome is once again sealed, the bacteria is now effectively re-programmed to replicate this new antiviral protein. The bacteria can continue to live a healthy life, though genetic engineering and human intervention has actively manipulated what the bacteria actually is. No doubt there are advantages and disadvantages, and this whole subject area will become more prominent over time.

The next page returns the more natural circumstances of genetic diversity.

Say no to genetic engineering

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While scientific progress on molecular biology has a great potential to increase our understanding of nature and provide new medical tools, it should not be used as justification to turn the environment into a giant genetic experiment by commercial interests. The biodiversity and environmental integrity of the world's food supply is too important to our survival to be put at risk.
Genetic engineering enables scientists to create plants, animals and micro-organisms by manipulating genes in a way that does not occur naturally.

These genetically modified organisms (GMO) can spread through nature and interbreed with natural organisms, thereby contaminating non 'GE' environments and future generations in an unforeseeable and uncontrollable way.

cancer

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Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age.[1] Cancer causes about 13% of all deaths.[2] According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007.[3] Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells[citation needed]. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers are usually affected by complex interactions between carcinogens and the host's genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments

Radiotherapy

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Radiation therapy
Main article: Radiation therapy
Radiation therapy (also called radiotherapy, X-ray therapy, or irradiation) is the use of ionizing radiation to kill cancer cells and shrink tumors. Radiation therapy can be administered externally via external beam radiotherapy (EBRT) or internally via brachytherapy. The effects of radiation therapy are localised and confined to the region being treated. Radiation therapy injures or destroys cells in the area being treated (the "target tissue") by damaging their genetic material, making it impossible for these cells to continue to grow and divide. Although radiation damages both cancer cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue. Hence, it is given in many fractions, allowing healthy tissue to recover between fractions.

Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, stomach, uterus, or soft tissue sarcomas. Radiation is also used to treat leukemia and lymphoma. Radiation dose to each site depends on a number of factors, including the radiosensitivity of each cancer type and whether there are tissues and organs nearby that may be damaged by radiation. Thus, as with every form of treatment, radiation therapy is not without its side effects

chemotherapy

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Chemotherapy is the treatment of cancer with drugs ("anticancer drugs") that can destroy cancer cells. In current usage, the term "chemotherapy" usually refers to cytotoxic drugs which affect rapidly dividing cells in general, in contrast with targeted therapy (see below). Chemotherapy drugs interfere with cell division in various possible ways, e.g. with the duplication of DNA or the separation of newly formed chromosomes. Most forms of chemotherapy target all rapidly dividing cells and are not specific for cancer cells, although some degree of specificity may come from the inability of many cancer cells to repair DNA damage, while normal cells generally can. Hence, chemotherapy has the potential to harm healthy tissue, especially those tissues that have a high replacement rate (e.g. intestinal lining). These cells usually repair themselves after chemotherapy.

Because some drugs work better together than alone, two or more drugs are often given at the same time. This is called "combination chemotherapy"; most chemotherapy regimens are given in a combination.

The treatment of some leukaemias and lymphomas requires the use of high-dose chemotherapy, and total body irradiation (TBI). This treatment ablates the bone marrow, and hence the body's ability to recover and repopulate the blood. For this reason, bone marrow, or peripheral blood stem cell harvesting is carried out before the ablative part of the therapy, to enable "rescue" after the treatment has been given. This is known as autologous stem cell transplantation. Alternatively, hematopoietic stem cells may be transplanted from a matched unrelated donor (MUD).

cancer repot of pakistan

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85,000 die of cancer in Pakistan every year



Wednesday, February 04, 2009
Muhammad Qasim

Islamabad

Cancer is a leading cause of death globally, particularly in the developing countries like Pakistan where less than 50% of the population is literate and the prospects of having good knowledge about the cancers seem poor.

Cancer is emerging as a major health problem in the country. Pakistan like other developing countries in the region is facing a double burden of diseases with a significant incidence of cancers and a rising trend in risk factor’s profile and incidence itself. The precise incidence, mortality rates, number of new cancer cases and number of deaths annually for Pakistan are not known however according to WHO estimates, as many as 61,624 incident cases and 42,624 cancer deaths annually in males and 75,095 incident cases and 43,188 deaths annually in females are reported.

In Pakistan, a large proportion of cancers presents at an advanced age. Health experts believe that lack of awareness about cancers, their signs and symptoms, is one of the major causes of delayed presentation. Experts say that awareness and education of masses is necessary to combat cancer, which is alarmingly increasing in the country.

“At least one-third to 40% of all cancer cases are preventable, mainly by not using tobacco, healthy diet and being physically active and preventing infections that may cause cancer,” said Professor of Community Medicine at Islamabad Medical and Dental College, Dr. Muhammad Ashraf Chaudhry, while talking to ‘The News’ Tuesday in connection with World Cancer Day which is observed on February 4 all around the globe. “Prevention offers the most cost-effective long-term strategy for the control of cancer.”

Talking of risk factors, Dr. Ashraf said that aging is the fundamental factor for the development of cancer. “The incidence of cancer rises dramatically with age. Lifestyle and environmental factors and the things we eat, drink, whether we smoke or exercise, how much sun we get and where we live have a powerful effect on cancer risk. One possible promoter in food is fat, especially saturated fat from animal products like meat,” he said. Tobacco use, pan, chalia, alcohol use, physical inactivity, being overweight and obese, exposure to occupational (e.g. asbestos) carcinogens, radiation (e.g. ultraviolet and ionising radiation), low fruit and vegetable intake, excessive consumption of red and preserved meat, high fat diet, genetic factors, having unsafe sex, infections from hepatitis B, hepatitis C, HIV, human papiloma viruses, helicobacter pylori, urban air pollution and indoor smoke from household use of solid fuels are major risk factors of cancer.

To a query, Dr Ashraf said that tobacco is the single largest preventable cause of cancer in the world today. “It causes 80-90% of all lung cancer deaths, and about 30% of all cancer deaths in developing countries. A comprehensive strategy including ban on tobacco advertising and sponsorship, tax increases on tobacco products, and cessation programmes can reduce tobacco consumption and can minimise incidence of cancers.” He added that cancer might affect anyone - the young and old, the rich and poor, men, women and children - and it represents a tremendous burden on families and societies.

Cancer is the uncontrolled growth and spread of cells. It can affect almost any part of the body. The growth often invades surrounding tissue and can metastasise to distant sites. Lung, stomach, liver, colon and breast cancer cause the most cancer deaths each year.

Dr Ashraf said that cancer’s seven warning signals (CAUTION) are: change in bowel or bladder habit, a sore that does not heal, unusual bleeding or discharge, thickening or lump in breast or elsewhere, indigestion or difficulty in swallowing, obvious change in wart or mole and nagging cough or hoarseness.

Talking of control on the disease, Dr Ashraf said that four basic components of cancer control are prevention, early detection, diagnosis and treatment, and palliative care. Dietary modification is an important approach to cancer control because there are many promoters and inhibitors in food.

Scientists believe that the food we eat is very important in the growth, or the prevention of cancer. Diets high in fruits, vegetables, whole grains, tomatoes, beans, pulses and legumes and avoiding processed foods high in fat, salt and/or sugar and sugary drinks, have a protective effect against many cancers. “Do not remove skin of fruits, potatoes, pears and apples etc. Avoid fried foods and bakery items. Limit your intake of salty foods such as pickles, nimco, chips etc.

Mothers should breastfeed their infants for at least six months. This practice offers cancer protection to both mother and the child. Drink at least 8 to 10 glasses of water a day,” said Dr Ashraf adding taking multi-vitamin is also not a bad idea.

He added that regular physical activity and maintenance of healthy body weight, along with a healthy diet might considerably reduce cancer risk. “Vaccination against human papiloma virus (HPV) and hepatitis B virus vaccination (HBV) might prevent cervical and liver cancer respectively.” Dr Ashraf believes that avoiding excessive exposure to solar ultraviolet radiation, use of sunscreen, wide-brimmed hats, large sunglasses, and protective clothing are effective preventive measures against skin cancer. “Asbestos can cause lung cancer, aniline dyes have been linked to bladder cancer and benzene can lead to leukaemia. The prevention of certain occupational and environmental exposure to these and other chemicals is another element in preventing cancer.”

cancer report of Pakistan

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Boitechnology

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Biotechnology in one form or another has flourished since prehistoric times. When the first human beings realized that they could plant their own crops and breed their own animals, they learned to use biotechnology. The discovery that fruit juices fermented into wine, or that milk could be converted into cheese or yogurt, or that beer could be made by fermenting solutions of malt and hops began the study of biotechnology. When the first bakers found that they could make a soft, spongy bread rather than a firm, thin cracker, they were acting as fledgling biotechnologists. The first animal breeders, realizing that different physical traits could be either magnified or lost by mating appropriate pairs of animals, engaged in the manipulations of biotechnology.
What then is biotechnology? The term brings to mind many different things. Some think of developing new types of animals. Others dream of almost unlimited sources of human therapeutic drugs. Still others envision the possibility of growing crops that are more nutritious and naturally pest-resistant to feed a rapidly growing world population. This question elicits almost as many first-thought responses as there are people to whom the question can be posed.
In its purest form, the term "biotechnology" refers to the use of living organisms or their products to modify human health and the human environment. Prehistoric biotechnologists did this as they used yeast cells to raise bread dough and to ferment alcoholic beverages, and bacterial cells to make cheeses and yogurts and as they bred their strong, productive animals to make even stronger and more productive offspring.
Throughout human history, we have learned a great deal about the different organisms that our ancestors used so effectively. The marked increase in our understanding of these organisms and their cell products gains us the ability to control the many functions of various cells and organisms. Using the techniques of gene splicing and recombinant DNA technology, we can now actually combine the genetic elements of two or more living cells. Functioning lengths of DNA can be taken from one organism and placed into the cells of another organism. As a result, for example, we can cause bacterial cells to produce human molecules. Cows can produce more milk for the same amount of feed. And we can synthesize therapeutic molecules that have never before existed.

Branches of Biotechnology

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Biotechnology has several different branches which are referred to by different terms mainly marked with different colors to describe the biotechnological field that it is used in. The most widely used ones will be introduced here. First of all there is the red biotechnology that is used for medical processes, like finding genetic cures by going through genomic manipulations and creating organisms to produce antibiotics.
Green biotechnology is used in reference to agricultural processes that use biotechnology. Some examples of that would be the development of transgenic plants that are designed to survive under specific environmental conditions. A big goal of the green biotechnology is to develop more environment friendly solutions, for example to find a way remove the need for pesticides.
The term used for industrial biotechnology is white biotechnology. This kind of biotechnology is used to reduce the costs for producing industrial goods that occur when traditional processes are used. For example, white biotechnology can develop an organism that is able to produce a certain beneficial chemical by natural processes rather than by industrial ways that it was done beforehand.
Some other examples of branches of biotechnology are blue biotechnology that deals with marine and aquatic usages of biotechnology, but that is not very widely used. When talking about not the direct research parts of biotechnology then bioeconomy is used to talk about the investments and the economical benefits that biotechnology brings.

Agriculture products

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Biotechnology brings a lot of benefits to the field of agriculture as it has been used for hundreds of years to develop the plants, nevertheless the scientist stil have many goals to reach. The main ones are to improve the amount of crop gained from the same amount of seeds as beforehand. Furthermore, also to decrease how much the environment affects the crops to make it more durable to the harmful factors. In addition, this field of biotechnology also aims to increase the nutritious qualities of the crops and also improve the texture and appearance of the food crops.
A very important aspect for the farmers is that the biotechnology decreases the need for fertilizers and pesticides that in some cases can remain in the crops. At the moment farmers are very dependant on agrochemicals, which not only increases their costs, but also affects the crops they gather. Therefore, it is essential for them to decrease this dependency to improve the quality of their agricultural producs.
Agricultural biotechnology also helps to develop ways how to use agricultural crops in other ways besides just for food. For example, usual plants like tomatoes, rice and lettuce have even been genetically engineered in a way that it is possible to produce insulin and some vaccines from them.

Pharmaceutical products

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Scientists find new pharmaceutical products by trial and error way with biotechnological methods. Basically, they try out different things that treat certain symptoms or diseases. One type of pharmaceutical products are biopharmaceuticals that are actually large biological molecules or in other words proteins. There proteins attack the pathway of the health problem. One special case is insulin that is used for type 1 diabetes, which does not attack the pathways, but just works on the symptoms of the disease. These pharmaceutical products are used in cases where the targets cannot be accessed by traditional medicine methods. Modern biotechnology has led us to time when insulin and antibiotics can be produced from E. coli or yeast. Even Chinese Hamster Ovary (CHO) can be used to produce some pharmaceutical products. A new way where this biotechnology is aiming is the development of plant- made pharmaceutical.The pharmaceutical products developed through biotechnology are the basis for the new breakthroughs in medicine that are enabling to treat hepatitis B, hepatitis C, cancers, arthritis, bone fractures, multiple sclerosis and cardiovascular disorders. Biotechnology has also helped to develop molecular diagnostic devices that are used to find out the target patient population for certain biopharmaceuticals. The pharmaceutical products used nowadays are also produced much faster and cheaply thanks to biotechnology. The most common examples of that are human growth hormone, fertility drugs, erythropoietin, clotting factors for hemophiliacs and many more. The genomic knowledge that scientist now have and will gain more in the future is believed to ensure the discovery of thousands of new molecular targets to which new drugs can then be developed.



How clones?

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How can cloning technologies be used?Recombinant DNA technology is important for learning about other related technologies, such as gene therapy, genetic engineering of organisms, and sequencing genomes. Gene therapy can be used to treat certain genetic conditions by introducing virus vectors that carry corrected copies of faulty genes into the cells of a host organism. Genes from different organisms that improve taste and nutritional value or provide resistance to particular types of disease can be used to genetically engineer food crops. See Genetically Modified Foods and Organisms for more information. With genome sequencing, fragments of chromosomal DNA must be inserted into different cloning vectors to generate fragments of an appropriate size for sequencing. See a diagram on constructing clones for sequencing.
If the low success rates can be improved (Dolly was only one success out of 276 tries), reproductive cloning can be used to develop efficient ways to reliably reproduce animals with special qualities. For example, drug-producing animals or animals that have been genetically altered to serve as models for studying human disease could be mass produced.
Reproductive cloning also could be used to repopulate endangered animals or animals that are difficult to breed. In 2001, the first clone of an endangered wild animal was born, a wild ox called a gaur. The young gaur died from an infection about 48 hours after its birth. In 2001, scientists in Italy reported the successful cloning of a healthy baby mouflon, an endangered wild sheep. The cloned mouflon is living at a wildlife center in Sardinia. Other endangered species that are potential candidates for cloning include the African bongo antelope, the Sumatran tiger, and the giant panda. Cloning extinct animals presents a much greater challenge to scientists because the egg and the surrogate needed to create the cloned embryo would be of a species different from the clone.
Therapeutic cloning technology may some day be used in humans to produce whole organs from single cells or to produce healthy cells that can replace damaged cells in degenerative diseases such as Alzheimer's or Parkinson's. Much work still needs to be done before therapeutic cloning can become a realistic option for the treatment of disorders.
What animals have been cloned? Scientists have been cloning animals for many years. In 1952, the first animal, a tadpole, was cloned. Before the creation of Dolly, the first mammal cloned from the cell of an adult animal, clones were created from embryonic cells. Since Dolly, researchers have cloned a number of large and small animals including sheep, goats, cows, mice, pigs, cats, rabbits, and a gaur. See Cloned Animals below. All these clones were created using nuclear transfer technology.
Hundreds of cloned animals exist today, but the number of different species is limited. Attempts at cloning certain species such as monkeys, chickens, horses, and dogs, have been unsuccessful. Some species may be more resistant to somatic cell nuclear transfer than others. The process of stripping the nucleus from an egg cell and replacing it with the nucleus of a donor cell is a traumatic one, and improvements in cloning technologies may be needed before many species can be cloned successfully.
Can organs be cloned for use in transplants?Scientists hope that one day therapeutic cloning can be used to generate tissues and organs for transplants. To do this, DNA would be extracted from the person in need of a transplant and inserted into an enucleated egg. After the egg containing the patient's DNA starts to divide, embryonic stem cells that can be transformed into any type of tissue would be harvested. The stem cells would be used to generate an organ or tissue that is a genetic match to the recipient. In theory, the cloned organ could then be transplanted into the patient without the risk of tissue rejection. If organs could be generated from cloned human embryos, the need for organ donation could be significantly reduced.
Many challenges must be overcome before "cloned organ" transplants become reality. More effective technologies for creating human embryos, harvesting stem cells, and producing organs from stem cells would have to be developed. In 2001, scientists with the biotechnology company Advanced Cell Technology (ACT) reported that they had cloned the first human embryos; however, the only embryo to survive the cloning process stopped developing after dividing into six cells. In February 2002, scientists with the same biotech company reported that they had successfully transplanted kidney-like organs into cows. The team of researchers created a cloned cow embryo by removing the DNA from an egg cell and then injecting the DNA from the skin cell of the donor cow's ear. Since little is known about manipulating embryonic stem cells from cows, the scientists let the cloned embryos develop into fetuses. The scientists then harvested fetal tissue from the clones and transplanted it into the donor cow. In the three months of observation following the transplant, no sign of immune rejection was observed in the transplant recipient.
Another potential application of cloning to organ transplants is the creation of genetically modified pigs from which organs suitable for human transplants could be harvested . The transplant of organs and tissues from animals to humans is called xenotransplantation.
Why pigs? Primates would be a closer match genetically to humans, but they are more difficult to clone and have a much lower rate of reproduction. Of the animal species that have been cloned successfully, pig tissues and organs are more similar to those of humans. To create a "knock-out" pig, scientists must inactivate the genes that cause the human immune system to reject an implanted pig organ. The genes are knocked out in individual cells, which are then used to create clones from which organs can be harvested. In 2002, a British biotechnology company reported that it was the first to produce "double knock-out" pigs that have been genetically engineered to lack both copies of a gene involved in transplant rejection. More research is needed to study the transplantation of organs from "knock-out" pigs to other animals.

Human Cloning

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IntroductionThe possibility of human cloning, raised when Scottish scientists at Roslin Institute created the much-celebrated sheep "Dolly" (Nature 385, 810-13, 1997), aroused worldwide interest and concern because of its scientific and ethical implications. The feat, cited by Science magazine as the breakthrough of 1997, also generated uncertainty over the meaning of "cloning" --an umbrella term traditionally used by scientists to describe different processes for duplicating biological material.
What is cloning? Are there different types of cloning?When the media report on cloning in the news, they are usually talking about only one type called reproductive cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism. A basic understanding of the different types of cloning is key to taking an informed stance on current public policy issues and making the best possible personal decisions. The following three types of cloning technologies will be discussed: (1) recombinant DNA technology or DNA cloning, (2) reproductive cloning, and (3) therapeutic cloning.
Recombinant DNA Technology or DNA Cloning
The terms "recombinant DNA technology," "DNA cloning," "molecular cloning," and "gene cloning" all refer to the same process: the transfer of a DNA fragment of interest from one organism to a self-replicating genetic element such as a bacterial plasmid. The DNA of interest can then be propagated in a foreign host cell. This technology has been around since the 1970s, and it has become a common practice in molecular biology labs today.
Scientists studying a particular gene often use bacterial plasmids to generate multiple copies of the same gene. Plasmids are self-replicating extra-chromosomal circular DNA molecules, distinct from the normal bacterial genome (see image to the right). Plasmids and other types of cloning vectors were used by Human Genome Project researchers to copy genes and other pieces of chromosomes to generate enough identical material for further study.
To "clone a gene," a DNA fragment containing the gene of interest is isolated from chromosomal DNA using restriction enzymes and then united with a plasmid that has been cut with the same restriction enzymes. When the fragment of chromosomal DNA is joined with its cloning vector in the lab, it is called a "recombinant DNA molecule." Following introduction into suitable host cells, the recombinant DNA can then be reproduced along with the host cell DNA. See a diagram depicting this process.
Plasmids can carry up to 20,000 bp of foreign DNA. Besides bacterial plasmids, some other cloning vectors include viruses, bacteria artificial chromosomes (BACs), and yeast artificial chromosomes (YACs). Cosmids are artificially constructed cloning vectors that carry up to 45 kb of foreign DNA and can be packaged in lambda phage particles for infection into E. coli cells. BACs utilize the naturally occurring F-factor plasmid found in E. coli to carry 100- to 300-kb DNA inserts. A YAC is a functional chromosome derived from yeast that can carry up to 1 MB of foreign DNA. Bacteria are most often used as the host cells for recombinant DNA molecules, but yeast and mammalian cells also are used.



Clonning Riks

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What are the risks of cloning? Reproductive cloning is expensive and highly inefficient. More than 90% of cloning attempts fail to produce viable offspring. More than 100 nuclear transfer procedures could be required to produce one viable clone. In addition to low success rates, cloned animals tend to have more compromised immune function and higher rates of infection, tumor growth, and other disorders. Japanese studies have shown that cloned mice live in poor health and die early. About a third of the cloned calves born alive have died young, and many of them were abnormally large. Many cloned animals have not lived long enough to generate good data about how clones age. Appearing healthy at a young age unfortunately is not a good indicator of long-term survival. Clones have been known to die mysteriously. For example, Australia's first cloned sheep appeared healthy and energetic on the day she died, and the results from her autopsy failed to determine a cause of death.
In 2002, researchers at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, reported that the genomes of cloned mice are compromised. In analyzing more than 10,000 liver and placenta cells of cloned mice, they discovered that about 4% of genes function abnormally. The abnormalities do not arise from mutations in the genes but from changes in the normal activation or expression of certain genes.
Problems also may result from programming errors in the genetic material from a donor cell. When an embryo is created from the union of a sperm and an egg, the embryo receives copies of most genes from both parents. A process called "imprinting" chemically marks the DNA from the mother and father so that only one copy of a gene (either the maternal or paternal gene) is turned on. Defects in the genetic imprint of DNA from a single donor cell may lead to some of the developmental abnormalities of cloned embryos

Gene therepy

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Gene therapy is used treat and sometimes it can even cure genetic diseases. This kind of therapy works so that a new gene is inserted into an adenovirus vector, then that vector introduces the modified DNA into the human cell. If the treatment works and the gene is not rejected than it will start to produce a functional protein. Basically the defected genes are either replaced or supplemented by the normal gene.
There are two types of gene therapies, one of them is somatic gene therapy and the other one uses germ cells. In case of somatic cells, the change made in is not transmitted to the next generation and in the other case the purpose of the change in the cells is made with the aim to transfer it to their next generation.
Gene therapy can be implemented in two ways, either outside of the body, ex vivo, or inside of the body, in vivo. In the first case the cells are removed from the patient’s blood or bone marrow and are grown in the lab. Afterwards these cells are exposed to a virus that is carrying the wanted gene, once the virus has entered the cells the gene will become part of the DNA of the cells. The cells are not inserted into the patient’s body straight after the DNA modification, but they are let grown in the laboratory and then injected into the vein of the patient. When in vivo method is used cells are not removed from the patient, vectors are used to insert the wanted gene into the body.
The usage of gene therapy is rather limited. The main reasons why gene therapy is not used widely to fight different diseases are the following. First of all, the vectors that are used to insert genes into the body are usually various viruses, but although they are effective can bring further problems like toxicity, immune responses and targeting issues. Secondly, scientists still have only limited knowledge of the real functions of most of the genes. And lastly, the extremely high costs of gene therapy.

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