The Kidneys

Furosemide

noreply@blogger.com (Bryan) — Tue, 31 Mar 2009 07:48:00 +0000

Furosemide, drug used to help the body remove excess fluid by increasing urine flow, also known as a diuretic. This is useful in the treatment of high blood pressure, congestive heart failure, kidney disease, and liver disease. It reduces water and salt in the body, relieving pressure on the circulatory system and various organs.

Furosemide must be prescribed by a doctor. Available in tablet and liquid form, it is usually taken twice a day in dosages starting at 20 to 80 mg. This is increased as needed to a maximum daily dosage of 600 mg. The drug may be taken with food to minimize stomach irritation.

Effectiveness is usually apparent after two to three weeks, although long-term treatment (months to years) is not uncommon with this drug. Potassium supplements or a potassium-rich diet is needed in some patients to prevent excess potassium loss.

Patients with liver or kidney disease, diabetes, gout, lupus erythematosus, or an allergy to sulfa drugs should use furosemide with caution. Its safety for use during pregnancy is not known, but it does appear in breast milk.

Children may take this drug, with dosage based on body weight.
Possible side effects may include constipation, diarrhea, nausea, headache, fever, dizziness, excessive thirst, skin rash, hives, impotence, ringing in the ears, light-sensitivity, or blurred vision. Furosemide may interact adversely with aspirin, barbiturates, narcotics, and other muscle-relaxing drugs.

SMOKING IS DANGEROUS TO YOUR HEALTH

noreply@blogger.com (Bryan) — Mon, 12 Jan 2009 00:19:00 +0000

Skull with a Burning Cigarette by Vincent van Gogh, oil on canvas, 1885.

SMOKING
Some epidemiologists noticed, however, that lung cancer, which was rare before the 20th century, had increased dramatically since about 1930. The American Cancer Society and other organizations initiated studies comparing deaths among smokers and nonsmokers over a period of several years. All such studies found increased mortality among smokers, both from cancer and other causes. In addition, experimental studies in animals showed that many of the chemicals contained in cigarette smoke are carcinogenic. In 1962 the U.S. government appointed a panel of ten scientists to study the available evidence. Their conclusions were included in the 1964 surgeon general’s report, which stated that “cigarette smoking is a health hazard of sufficient importance in the United States to warrant appropriate remedial action.” Smoking in adults, measured as an average number of cigarettes smoked per year, began to decline steadily after the 1964 report and has fallen more than 40 percent.

Smoking, inhalation and exhalation of the fumes of burning tobacco. Leaves of the tobacco plant are smoked in various ways. After a drying and curing process, they may be rolled into cigars or shredded for insertion into smoking pipes. Cigarettes, the most popular method of smoking, consist of finely shredded tobacco rolled in lightweight paper. About 48 million people in the United States smoke an estimated total of 430 billion cigarettes each year. Until the 1940s, smoking was considered harmless, but laboratory and clinical research has since confirmed that tobacco smoke presents a hazard to health. Smoke from the average cigarette contains around 4,000 chemicals, some of which are highly toxic and at least 43 of which cause cancer. Nicotine, a major constituent of tobacco smoke, is both poisonous and highly addictive. According to the American Cancer Society, smoking is the most preventable cause of death in America today.

HEALTH EFFECTS OF SMOKING
The American Cancer Society estimates that cigarettes are responsible for about 431,000 deaths in the United States each year. Lung cancer accounts for about 30 percent of all cancer deaths in the United States, and smoking accounts for nearly 90 percent of lung cancer deaths.

The risks of dying from lung cancer are 23 times higher for male smokers and 13 times higher for female smokers than for nonsmokers. Additionally, smokers are at increased risk for cancer of the larynx, oral cavity, esophagus, bladder, kidney, and pancreas.

Smoking causes a fivefold increase in the risk of dying from chronic bronchitis and emphysema, and a twofold increase in deaths from diseases of the heart and coronary arteries. Smoking also increases the risk of stroke by 50 percent—40 percent among men and 60 percent among women.

Other research has shown that mothers who smoke give birth more frequently to premature or underweight babies, probably because of a decrease in blood flow to the placenta. Babies born to mothers who smoke during pregnancy are also at increased risk for sudden infant death syndrome.

Cigar and pipe smoke contains the same toxic and carcinogenic compounds found in cigarette smoke. A report by the National Cancer Institute concluded that the mortality rates from cancer of the mouth, throat, larynx, pharynx, and esophagus are approximately equal in users of cigarettes, cigars, and pipes.

Rates of coronary heart disease, lung cancer, emphysema, and chronic bronchitis are elevated for cigar and pipe smokers and are correlated to the amount of smoking and the degree of inhalation.

The ways in which tobacco smoke affects the human body have been studied intensely. Recent findings may explain why cigarettes are addictive. An unknown component of tobacco smoke appears to destroy an important brain enzyme, monoamine oxidase B (MAO B). The enzyme is vital for breaking down excess amounts of dopamine, a neurotransmitter that triggers pleasure-seeking behavior.

Smokers have decreased levels of MAO B and abnormally high levels of dopamine, which may encourage the smoker to seek the pleasure of more tobacco smoke.
Recent research has focused on the effects of environmental tobacco smoke (ETS)—that is, the effect of tobacco smoke on nonsmokers who must share the same environment with a smoker.

The United States Environmental Protection Agency (EPA) estimates that exposure to ETS, which contains all the toxic agents inhaled by a smoker, causes 3,000 cancer deaths and an estimated 40,000 deaths from heart disease per year in nonsmokers. Secondhand smoke can aggravate asthma, pneumonia, bronchitis, and impaired blood circulation.

The smoking habit and addiction to nicotine usually begin at an early age. In the United States, more than 70 percent of adults who smoke began smoking before the age of 18. This fact has led to particular concern over smoking in teenagers and young adults.

From the early to mid-1990s the proportion of teenage smokers in the United States rose from one-quarter to one-third, despite increasing warnings about the health hazards of smoking and widespread bans on smoking in public places.

A 1998 report from the surgeon general confirmed that this trend continues, especially among racial and ethnic minorities. For example, although black teenagers have the lowest smoking rates of any racial group, cigarette smoking among black teens increased 80 percent in the late 1990s. Advertisements aimed at a young audience are largely blamed for this new generation of smokers.

CAUSES OF CANCER

noreply@blogger.com (Bryan) — Mon, 29 Dec 2008 23:09:00 +0000

A. CARCINOGENS
One of the greatest risk factors for cancer is prolonged or repeated exposure to carcinogens—chemical, biological, or physical agents that cause the cellular damage that leads to cancer.

The details of how carcinogens cause cancer remain unclear.
One theory is that exposure to carcinogens, when combined with the effects of aging, causes an increase in chemicals in the body called free radicals.

An excessive number of free radicals causes damage by taking negatively charged particles called electrons from key cellular components of the body, such as DNA.
This may make genes more vulnerable to the mutating effects of carcinogens.

1. Tobacco smoke
2. Diet
3. Pathogens
4. Radiation
5. Environmental and Occupational chemicals

B. HEREDITARY FACTORS
Evidence suggests that heredity plays a role in developing cancer.
Some gene mutations associated with cancer are inherited.

For example, inheritance of the mutated tumor suppressor genes BRCA1 or BRCA2 greatly increases the risk of breast cancer in young women.
About 50 to 60 percent of women with inherited BRCA1 or BRCA2 mutations will develop breast cancer by the age of 70.

Inherited mutations in the genes MSH2, MLH1, PMS1, and PMS2, all of which repair DNA, are especially prevalent in a rare form of hereditary colon cancer.

Scientists suspect that many other hereditary factors contribute to cancer.
In addition to inherited mutations, other genetic variations, particularly those influencing how the body responds to carcinogens, may create a greater susceptibility to cancer.
The identities of the majority of these genetic variations are not yet known.

C. STEROID HORMONES
Medical research suggests that cancers of the reproductive organs may be affected by naturally occurring steroid hormones produced by the endocrine system.
These hormones stimulate reproductive organ cells to divide and grow.

In women, relatively high or long exposure to the female sex hormone estrogen seems to increase the risk of breast and uterine cancers.
Thus, early age at first menstruation, late age at menopause, having children after age 30, and never having children, all of which affect the duration of estrogen exposure in the body, increase the risk for these cancers.

Some evidence also suggests that estrogen replacement therapy (ERT), in which women take estrogen to offset the unpleasant effects of menopause, may also increase the risk of some cancers of the reproductive organs.
The risk appears to go down significantly, however, when estrogen and another female sex hormone, progesterone, are taken together.

At one time studies showed a link between birth control pills and cancer. However, these studies examined early forms of birth control pills, which contained high levels of estrogen.
Today’s birth control pills contain progesterone, as well as lower levels of estrogen, and carry very little risk of cancer.
Male sex hormones, particularly testosterone, also appear to play a role in cancers of the male reproductive organs, but this role is not yet well understood.

D. POPULATION DEMOGRHAPICS
Population studies show that a person’s age, race, and gender affect the probability that he or she will develop cancer.
Most cancers occur in adults middle-aged or older.
The risk of cancer increases as individuals age because genetic mutations accumulate slowly over many years, and the older a person is, the more likely that he or she will have accumulated the collection of mutations necessary to turn an otherwise healthy cell into a cancerous cell.

Women aged 20 to 29, for example, account for just 0.3 percent of all cases of breast cancer, but women over age 50 account for more than 75 percent of breast cancer cases.
Cancer of the prostate gland shows similar age discrimination.
According to the American Cancer Society (ACS) and the National Cancer Institute of Canada (NCIC), more than 75 percent of all prostate cancers are diagnosed in men who are over the age of 65.

Statistics show that men are more likely to develop cancer than women. In the United States, half of all men will develop cancer at some point in their lifetimes.
About one-third of all American women will develop cancer.
Cancer statistics for Canada are similar.
Stomach cancer is about twice as common in men than in women, as are certain types of kidney cancer.

However, the reasons for the discrepancy between the sexes are unknown.
Some cancers are more prevalent in particular races than others.
In the United States, for example, bladder cancer is twice as common in white people than it is in black people.
White women are slightly more likely to develop breast cancer than are black women, but black women are more likely to die of the disease.

Asian, Hispanic, and Native American women have the lowest breast cancer risk.
On the whole, African Americans, especially men, are more likely to develop cancer—and more likely to die from it—than members of any other group in the United States.
Reasons for the discrepancies between races are still not entirely clear, but many epidemiologists trace them to differences in diet and exercise, unequal access to medical care, and exposure to carcinogens.

Factors that affect the development of Cancer

noreply@blogger.com (Bryan) — Mon, 29 Dec 2008 23:02:00 +0000

Scientists do not fully understand the causes of cancer, but studies show that some people are more likely to develop the disease than others.
The incidence of cancer varies enormously among different regions.
The highest death rate from all cancers in males is 272 per 100,000 men in Hungary while the lowest death rate of 80 men per 100,000 is found in Mauritius, an island off the coast of eastern Africa.

For women the highest cancer rate is 140 per 100,000 women in Denmark compared to only 63 per 100,000 women in Azerbaijan in western Asia.
The figures for the United States are 156 per 100,000 men and 108 per 100,000 women.
For particular cancers, the difference between countries may be as high as 40-fold.
Differences also occur within populations.
Cancer rates vary between sexes, races, and socioeconomic groups, for example.

Scientists called epidemiologists study particular populations to identify why cancer rates vary One method they use is to compare behavior and characteristics such as the gender, age, diet, or race of cancer patients to those of healthy people.
Population studies provide useful information about risk factors that increase the likelihood of developing cancer.

Merry Christmas to all

noreply@blogger.com (Bryan) — Thu, 25 Dec 2008 06:29:00 +0000

A MERRY MERRY CHRISTMAS TO ALL!!!!

Santa Claus, also known as Saint Nicholas, Father Christmas, Kris Kringle, or simply "Santa", is the legendary and mythical figure who, in many Western cultures, brings gifts to good children during the late evening and overnight hours of Christmas Eve, December 24 or on his Feast Day, December 6 (Saint Nicholas Day).

The modern portrayal of Santa Claus

frequently depicts him listening

to the Christmas wishes of young children.

The legend may have part of its basis in hagiographical tales concerning the historical figure of Saint Nicholas.
While Saint Nicholas was originally portrayed wearing bishop's robes, in modern times, Santa Claus is generally depicted as a plump, jolly, white-bearded man wearing a red coat with white collar and cuffs, white-cuffed red trousers, and black leather belt and boots.

This image became popular in the United States in the 19th century due to the significant influence of caricaturist and political cartoonist Thomas Nast.

1881 illustration by Thomas Nast

who, with Clement Clarke Moore,

helped to create the modern image of Santa Claus.

This image has been maintained and reinforced through song, radio, television, and films.

In the United Kingdom and Europe, his depiction is often identical to the American Santa, but he is commonly called Father Christmas.

One legend associated with Santa says that he lives in the far north, in a land of perpetual snow.

The American version of Santa Claus lives at the North Pole, while Father Christmas is said to reside in Lapland, Finland.

Other details include: that he is married and lives with Mrs. Claus; that he makes a list of children throughout the world, categorizing them according to their behavior ("naughty" or "nice"); that he delivers presents, including toys, candy, and other presents to all of the good boys and girls in the world, and sometimes coal or sticks to the naughty children, in one night; and that he accomplishes this feat with the aid of magical elves who make the toys, and eight or nine flying reindeer who pull his sleigh.

There has long been opposition to teaching children to believe in Santa Claus.

Some Christians say the Santa tradition detracts from the religious origins and purpose of Christmas.

Other critics feel that Santa Claus is an elaborate lie, and that it is unethical for parents to teach their children to believe in his existence.

Still others oppose Santa Claus as a symbol of the commercialization of the Christmas holiday, or as an intrusion upon their own national traditions.

Colic

noreply@blogger.com (Bryan) — Tue, 09 Dec 2008 22:13:00 +0000

Colic, severe abdominal pain, a symptom of several disorders.

When arising in the intestine, it is characterized by spasmodic and irregular contractions of the muscular coat of the intestines.
Intestinal colic is often caused by infection, obstruction, irritating food, or purgative medicine. The etiology of infant intestinal colic is poorly understood, although gas and disturbed digestion are suspected causes.
Renal colic is caused by a passage of a calculus, or stone, from the kidney through the ureter into the urinary bladder.
Biliary colic is caused by the passage of a gallstone from the gallbladder into the bile ducts.
The symptoms of colic are often confused with those of appendicitis and peritonitis.

Medical transplantation

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:44:00 +0000

Medical Transplantation, transfer of a living tissue or organ to an injured or ill person to restore health or reduce disability. Over the past 45 years, surgeons have made great strides in their ability to implant organs in people who are seriously ill. At least 21 different organs—such as hearts, livers, and kidneys—and tissues—such as corneas and bone marrow—can now be successfully transplanted into patients who can then expect to survive for years or even decades.

Each year, more than 20,000 internal organs are successfully implanted into patients in the United States and more than 1,600 organ transplants are performed in Canada. Improved surgical techniques are partly responsible for the success of organ transplants, but a more important factor is the development of drugs that can suppress the body’s rejection of the implanted organ without also leaving the patient highly susceptible to infections.

But this success also created a major problem: as the demand for organs grew, it soon outstripped the supply of donated organs. As of April 2001, more than 76,000 Americans were on a waiting list for organs or tissues and as of December 2000, more than 3,540 Canadians were also on a waiting list.

Each year in the United States, more than 4,000 die before a donated organ can be found. In order to match the scarce supply of donated organs with critically ill patients, in 1984 the United States Congress passed the National Organ Transplant Act to regulate the transplant business. The United Network for Organ Sharing (UNOS) serves as the umbrella organization for organ procurement and transplantation centers around the nation.

When a physician determines that a patient requires a transplant, the patient’s medical information is sent to the closest transplant center. At the transplant center, candidates are evaluated and ranked according to medical criteria. The patient’s medical records are then sent to UNOS for inclusion on its computerized waiting list.

When a donated organ becomes available, it is offered to patients on a waiting list in the donor’s local area. A match is made if laboratory tests show that the recipient is compatible with the available organ, reducing the risk that the organ will be rejected, and if the patient is healthy enough and available to undergo major surgery immediately. If the highest-ranked patient on the list does not meet these criteria, the organ is offered to the next patient on the list. If no one locally can use the organ, it is offered regionally. If it cannot be used regionally, in rare cases the organ is offered to the highest-ranking patient elsewhere in the United States.

In some cases, this system of organ allocation means that people living in certain areas of the country who require a transplant receive a donor organ faster than people living in other areas of the country. To make organ allocation more equitable, in early 2000 the U.S. Department of Health and Human Services (HHS) proposed legislation that called for enhanced government oversight of organ allocation policies. If enacted, the legislation would establish guidelines ensuring that a donated organ or tissue is offered to the patient in most need, no matter where the patient lives.

Most transplanted organs are from people who have died recently, particularly people involved in accidents injuring the head. Once all brain activity stops in a patient, the person is considered legally dead. When the brain dies, the rest of the body is kept alive temporarily until organs can be removed. Someone from either the hospital staff or a local organ procurement organization asks the victim’s family for permission to harvest the organs. To save time and increase the supply of organs, many states encourage people to sign and carry donor cards that indicate their willingness to donate their organs in the event of an accidental death. This information can also be displayed on the driver’s license in many states.

Some organs and tissues can be donated from living donors. For example, millions of people each year donate blood. After donating about 500 ml (about 1 pt) of blood, the donor’s body quickly grows new blood cells to replace the donated ones. The donor suffers no ill effects of donating blood. Other organs that can come from living donors include the kidney and the liver.

Transplant Rejection

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:40:00 +0000

For medical transplantation to be successful, physicians must elude the combative efforts of the body’s complex immune system, which fights to protect the body from infections of all sorts.

Central to the functioning of the immune system is its ability to distinguish between invading or foreign matter, which should be attacked, and matter that is a normal part of the body, which should not be attacked.

This recognition system uses specific markers called histocompatibility antigens that are on the surface of all cells in an individual’s body. The immune system attacks anything that lacks these histocompatibility antigens or has antigens different from those found in the rest of the body, such as those found on invading viruses, bacteria, or other microorganisms.

This recognition system causes the immune system to attack transplanted tissues that have different antigens because it has no way to distinguish between harmful and beneficial foreign matter.

There are over 200 different histocompatibility antigens, with each individual having a specific set of them. The odds that two unrelated people will have the same set of histocompatibility antigens are about one in 30,000.

Transplant surgeons attempt to match histocompatibility antigens of the donor and the recipient as closely as possible in order to minimize rejection. In most cases, the match will not be exact, and the recipients must take drugs to suppress the immune response.

The first drugs that were used were azathioprine and prednisone. But these drugs suppress the entire immune system, leaving the recipient vulnerable to infections and certain cancers. They also have toxic side effects.

A major breakthrough in immune suppression was the development of cyclosporine, a natural product derived from a fungus found in soil. Cyclosporine suppresses the part of the immune system involved in organ rejection with less severe impact on other parts of the immune system.

A few years later, the drug tacrolimus (FK-506) was found to be even more effective for kidney, liver, heart, and lung transplants. However, patients who take these two drugs still face some increased risk of infection and cancer, and the drugs can cause kidney damage. Doctors often use a combination of immune-suppressing drugs to limit these side effects.

Types of Transplants

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:32:00 +0000

Kidneys

Kidneys are the most common organs to be transplanted. Kidneys remove waste products from the blood stream. If they fail, often as a result of diabetes mellitus or cancer, a person can die from the buildup of these toxic materials.

The waste products can be removed artificially through a process called kidney dialysis, but the patient must be hooked up to the dialysis machine two to three times each week for as long as 12 hours at a time.

Kidney transplants free the recipient from dependence on dialysis. If the kidney is rejected, the patient must go back on dialysis or receive another transplant.

The first successful transplant of any organ was performed in 1954, when American surgeon Joseph Murray successfully transplanted a kidney donated from the recipient’s twin brother.

In the United States, some 13,290 kidney transplants were performed in 2000, of which 5,227 came from living donors. The one-year survival rate for kidney transplant patients is about 95 percent. Some kidney transplant patients have survived more than 25 years.

Because people have two kidneys but need only one, a living relative often serves as a donor, retaining one kidney for his or her own use. About one-third of transplanted kidneys come from living relatives and about two-thirds are from someone who recently died.

Many patients whose kidney failure was caused by diabetes mellitus receive a pancreas transplant at the same time. The pancreas normally secretes insulin, a substance that helps the body use and store sugars. In some diabetics, the body’s immune system destroys insulin-secreting cells in the pancreas.

In many cases, the disease can be controlled with shots of insulin. However, if the diabetic requires a kidney transplant, the surgeon will often transplant a pancreas at the same time. In 2000, there were 436 pancreas transplants and 914 simultaneous kidney and pancreas transplants performed in the United States. The one-year survival rate for pancreas transplant patients is about 95 percent.

Heart Transplant

Heart transplants are perhaps the most dramatic of all organ transplants because without a functioning heart, a patient cannot survive more than a few minutes. The heart is also more sensitive to a lack of blood than other organs, and can be preserved for only a few hours without damage.

The first successful heart transplant was conducted in December 1967 by South African surgeon Christiaan Barnard. It was not until cyclosporine was approved for clinical use in the United States in 1983 that heart transplants gained widespread use. Most patients are able to resume a normal life about six months after surgery, and about 84 percent of them survive the first year. In 2000, about 2,200 patients received heart transplants, and 48 received heart-lung transplants, in the United States.

Liver failure caused by cirrhosis, cancer, or hepatitis can be fatal. The liver is the only internal organ with the capacity to regenerate. This capacity provides the surgeon additional flexibility in treating liver damage. For instance, if the damage is not very severe, a temporary transplant can take over the liver’s function while the patient’s own liver recovers. It is also possible to remove part of a liver from a living donor and transplant it. After the surgery both the donor’s liver and the transplanted portion will grow to full size. In 2000, about 4,900 livers were transplanted. The one-year survival rate is about 84 percent.

Lungs Transplant

Lung transplants are used to replace a single diseased lung, and sometimes both lungs. In some cases lung disease has damaged the heart, and these cases may benefit from a combined heart-lung transplantation. Successful lung transplants are hampered by the difficulty in preserving a lung from a person who has recently died so that it is still viable by the time a proper recipient is found. In 2000, 956 lungs were transplanted in the United States. The one-year survival rate for lung transplants is about 74 percent.

Other organ transplant surgeries are being developed and some are still in the experimental stage. In 2000, 79 small intestines were transplanted in the United States to replace organs damaged by disease. Reliable survival data for intestine transplant patients are not yet available because the procedure is still experimental.

Tissue Transplant

The most common tissue transplant is blood transfusion, commonly used to replace blood lost by a person in an accident or during surgery. Other tissues commonly transplanted include bone marrow, corneas, skin, bone, cartilage, tendons, and blood vessels.

Bone marrow is the living tissue found in the center of many large bones of the body. Special cells in the bone marrow, called stem cells, are the source of both red blood cells, the primary component of blood, and white blood cells, the workhorses of the immune system. Certain blood diseases, including leukemia and sickle-cell anemia, are the result of the stem cells in the bone marrow producing faulty blood cells.

In some cases, these diseases can be treated by destroying all of the patient’s bone marrow and replacing it with new donor bone marrow that does not produce the faulty blood cells. Bone marrow transplants are also used in fighting breast and other cancers because intensive radiation or chemotherapy used to cure the cancer also kills the patient’s bone marrow, which must then be replaced with a transplant.

Bone marrow transplants require a closer matching of donor and recipient than is the case with other types of transplants. If the match is not good enough, the recipient’s body may reject the bone marrow or the white blood cells generated by the donor marrow can attack the recipient’s body, a phenomenon known as graft-versus-host disease.

About 30 percent of patients who require a bone marrow transplant have a close family member who is suitably matched. The rest must find a suitable donor. In the United States, the federal government has established the National Marrow Donor Program registry, which currently lists more than 4 million potential donors.

More than 1,500 bone marrow transplants occur every year in the United States from marrow donated from unrelated people. The success rate of a transplant depends on the disease being treated. Transplants to treat sickle-cell anemia have a 90 percent success rate, but success rates are only in the 30 to 60 percent range for other diseases.

Cornea Transplant

The cornea is the transparent front covering of the eye and is necessary for vision. Cornea transplants replace corneas that have become cloudy, swollen, or painful, usually as a long-term complication from cataract surgery.

Corneas can also become scarred after an injury or require replacement because of birth defects. Cornea transplants are very successful, with a success rate of more than 90 percent if the cornea is placed on the eye in such a manner that blood vessels do not come into contact with it. Without blood vessels, the body cannot send immune cells to attack the cornea.

About 33,000 cornea transplants are performed every year. Eye surgeons can also transplant scleral tissue, the fibrous tissue that forms the white of the eye. Sclera transplants are used to treat glaucoma patients and those requiring reconstructive eye surgery.

Skin was the first tissue transplanted, and researchers used skin transplants in the late 1950s and early 1960s to decipher the immune system response to transplants. Most skin transplants are so-called autografts, in which skin is taken from one site on the recipient’s body and grafted onto an injured site, thus avoiding the problems with rejection.

However, in cases where the amount of skin needed is greater than the recipient can provide, such as in burn victims with extensive burns, skin from donors is used.

Donated skin is useful, even if not properly matched, since it provides temporary protection from infection while new skin grows. By the time the graft is rejected, new skin is present.

Other Organ and Tissue Sources

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:24:00 +0000

Other Organ and Tissue sources
In addition to organs donated from humans, researchers are exploring the use of partially or wholly artificial organs manufactured in the laboratory. The use of organs from other species of mammals, a technique called xenotransplantation, is also being researched.

Artificial Organs and Tissues
One way to get around the shortage of donors is to use wholly or partially artificial organs made of plastic, metal, and other synthetic materials. A kidney dialysis machine, for example, is an artificial organ, even if it is too large to implant in the body.

In 1982 American physician William DeVries implanted a crude artificial heart into the chest of dentist Barney Clark. But Clark survived for only 112 days and the heart itself, powered by an air pump that required its own cart, proved impractical.

Although subsequent researchers have built smaller, more efficient hearts, none of these devices have proved successful. Instead, emphasis has shifted to the use of left-ventricular assist devices (LVADs), which are implanted beside a patient’s heart to help it pump blood. LVADs keep patients alive until a donor heart is available.
Many artificial devices work to restore the operation of malfunctioning organs without replacing the whole organ. Examples include artificial heart valves and pacemakers to help the heart function properly, and cochlear implants to restore hearing.

Other researchers are working to build replacement organs and tissues from human cells, a technique known as tissue engineering. The Food and Drug Administration (FDA) has approved two types of artificial skin made by growing a relatively small number of human skin cells on an artificial surface in the laboratory.

The cells multiply and grow into a useful skin covering that can be used to cover larger areas than are possible with a simple autograft. Researchers hope to develop other types of artificial organs as well, such as artificial pancreases in which insulin-secreting pancreatic cells are enclosed in a porous membrane that enables nutrients, but not immune cells, to reach the cells while insulin diffuses out.

Some scientists hope to use embryonic stem cells, which are found in very early stage human embryos and are capable of developing into almost any type of cell in the body, to overcome the shortage of donor organs. If researchers learn how to make embryonic stem cells develop into specific tissues, the cells could be used to produce new organs or to repair organs, such as the heart, that cannot regenerate.

The First Baboon Organ Transplant

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:21:00 +0000

Xenotransplants
The shortage of donors has led some surgeons to consider using animals as donors. Chimpanzee kidneys were successfully transplanted in 1963, with one recipient living for nine months after the surgery. Although the kidneys were not rejected, they proved too small to keep the recipient alive. Efforts to transplant chimpanzee and baboon hearts into humans in the 1960s and 1970s also failed because the hearts were too small.

The first successful baboon organ transplant occurred in 1984, when a baboon’s heart was transplanted into a two-week-old premature baby whose heart was congenitally malformed. The baby survived for 20 days before her body rejected the organ. Because of problems with the small size of chimpanzee and baboon organs, doctors are now turning to other species as potential organ donors.

One animal receiving a lot of attention from the medical community is the pig. Pigs have organs that are the right size for human use, they have large litters, and they mature quickly so there is a ready supply of donating animals. Human bodies do not reject some pig tissues, such as heart valves. Surgeons in the United States transplant about 60,000 pig heart valves into humans annually. However, other transplanted pig organs undergo a phenomenon called hyperacute rejection.

The recipient’s immune system recognizes that the blood vessels in the transplanted organ are foreign and shuts off blood flow to the new organ within hours or even minutes, causing the transplanted organ to blacken and die. Recently, scientists have used genetic engineering techniques to breed pigs whose blood vessels contain the marker antigens found in human blood vessels.

Livers from these pigs have been successfully connected to the bloodstream of several patients to clear toxic wastes while the patients’ own livers recovered. Fetal pig brain cells have also been used to treat Parkinson disease, and research is underway on using other organs from these pigs.

One of the big drawbacks of xenotransplants is the fear that unknown, possibly deadly viruses could be transferred from animals to humans. Once the animal viruses get into humans, they might spread to other humans. In 1997, scientists showed that pig viruses could infect humans with unpredictable results. The unresolved questions surrounding xenotransplantation mean that future research must be done cautiously.

Ethical Issues Haunt The Transplant Field

noreply@blogger.com (Bryan) — Sun, 30 Nov 2008 03:19:00 +0000

ETHICAL ISSUES
A number of ethical issues haunt the transplant field. With few exceptions, donated organs go to the patient who is nearest death, even though a healthier patient might benefit more by living longer after the transplant. People who need a second, third, or fourth transplant because their prior transplants failed usually gain top priority, even though they are not likely to do as well as patients who have not already had a transplant.

Some critics object to giving organs to patients whose organ failure was the result of their own actions, such as cirrhosis of the liver resulting from alcohol abuse.
Money is also a major issue. Access to transplantation is impossible without access to good primary medical care and good insurance, both of which are largely unavailable to the poor. To be placed on the waiting list, patients must show they can pay for the transplant.

In 2000 a kidney transplant cost about $111,000 and a liver transplant as much as $250,000 in the first year after the surgery. Many insurance companies do not cover such costs, particularly for the new procedures, such as lung, pancreas, or multiple organ transplants, which are still considered experimental.

Although organs cannot be bought and sold legally in the United States, there is evidence that a black market in organs exists in China and other countries. Persistent allegations have been made of people traveling to China and paying for organ transplants. Human rights groups have reported evidence that the bodies of executed prisoners are the source for most of the organs transplanted in China.

In the United States, where organ donation is voluntary, ethical questions arise over the nature of the consent and the use of incentives. Intensive donor solicitations in recent years have not made much of a dent in the shortages of organs.

Even though many people sign organ donor cards, their families are often reluctant to grant permission at the moment of crisis. Some ethicists debate whether family members should have the right to refuse donation if the deceased signed an organ donor card.
Presumed consent laws, in which everyone would be considered willing donors unless they have specifically said they were unwilling, have been tried in Europe and South America, and on a limited basis in Pennsylvania and Maryland. Some experts have suggested financial incentives, such as cash rebates, estate tax discounts, or payment for burial expenses.

Others have suggested broadening the criteria used to determine death beyond the lack of all brain activity. This would permit a surgeon to use organs from anencephalic children, who are born without a brain, and from people in a persistent vegetative state.
The implantation of tissues from aborted fetuses into the brain has proved a possible treatment for both Parkinson and Huntington’s disease, but the treatment has raised its own set of ethical questions.

The foremost is the question of abortion itself. The possibility of using embryonic stem cells to create replacement organs has faced opposition for similar reasons.
Some researchers believe that this issue can be surmounted by growing cells in the laboratory or by genetically engineering a patient’s own skin cells. Fetal pig cells have also been used as a treatment for Parkinson and Huntington’s disease, but that raises other ethical issues regarding the treatment of animals.

First Reliable Report of Transplant Surgery

noreply@blogger.com (Bryan) — Fri, 28 Nov 2008 23:13:00 +0000

HISTORY
The first reliable report of a transplant surgery is from 1823 when German surgeon Carl Bunger performed plastic surgery on a woman’s nose, grafting skin from her thigh. By 1863, French physiologist Paul Bert had demonstrated that tissues transplanted from one person to another are rejected. Forty years later, German biologist Carl O. Jensen found that this rejection was carried out by the immune system.

During the early 20th century, researchers such as the French surgeon Alexis Carrel and American physiologist Charles Guthrie developed the surgical techniques needed for performing transplants, but rejection remained a problem. In 1958 French immunologist Jean-Baptiste-Gabriel-Joachim Dausset discovered the histocompatibility system for tissue matching.

Minimizing histocompatibility differences, along with the development of the first immunosuppressive drugs azathioprine and prednisone, made transplants possible in the 1950s. Nonetheless, they remained relatively rare until Swiss biochemist Jean Borel discovered the remarkable immunosuppression properties of cyclosporine in 1972.
Cyclosporine revolutionized the field when it was marketed in 1983, making transplants more common.

Thomas H. Maugh II

National Institute of Diabetes and Digestive and Kidney Diseases

noreply@blogger.com (Bryan) — Thu, 27 Nov 2008 23:27:00 +0000

National Institute of Diabetes and Digestive and Kidney Diseases
Founded in 1950, the National Institute of Diabetes and Digestive and Kidney Diseases funds and coordinates research involving metabolic disorders such as diabetes, digestive diseases, and kidney dysfunction.
It also leads federal research on nutrition and supports more than 20 centers around the United States dedicated to nutrition, digestive diseases, and obesity.

Known Physician.
Bright, Richard (1789–1858)
British physician, who described many conditions and linked edema (accumulation of fluid in the body) to kidney disease. Bright's disease, an acute inflammation of the kidneys (Nephritis), is named for him.

Bright was born in Bristol, England, and studied medicine at Edinburgh University in Scotland. He was on the staff of Guy's Hospital in London, England, from 1820.
Bright initiated the use of biochemical studies by working with chemists to demonstrate that urea is retained in the body during kidney failure.
He also correlated symptoms in patients with the pathological changes he later found in postmortem examinations of the same people.
In this way he found that the presence of the protein albumin in the urine and edema are associated with pathological changes in the kidneys.

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 22:14:00 +0000

Everybody knows that some organs in the human body are necessary for survival;
you need;

your brain
your heart
your lungs
your kidneys

KIDNEYS
the kidneys are every bit as important as the heart.
You need at least one kidney to live!

Kidneys normally come in pairs.
If you've ever seen a kidney bean, then you have a pretty good idea what the kidneys look like.

Each kidney is about 5 inches (about 13 centimeters) long and about 3 inches (about 8 centimeters) wide — about the size of a computer mouse.

To locate your kidneys, put your hands on your hips, then slide your hands up until you can feel your ribs.
Now if you put your thumbs on your back, you will know where your kidneys are.
You can't feel them, but they are there.

One of the main jobs of the kidneys is to filter the waste out of the blood.
How does the waste get in your blood? Well, your blood delivers nutrients to your body.
Chemical reactions occur in the cells of your body to break down the nutrients.
Some of the waste is the result of these chemical reactions.
Some is just stuff your body doesn't need because it already has enough.
The waste has to go somewhere; this is where the kidneys come in.
First, blood is carried into the kidneys by the renal artery (anything in the body related to the kidneys is called "renal").
The average person has 1 to 1½ gallons of blood circulating through his or her body.
The kidneys filter that blood as many as 400 times a day! More than 1 million tiny filters inside the kidneys remove the waste.
These filters, called nephrons (say: neh-fronz), are so small you can see them only with a high-powered microscope.
The waste that is collected combines with water (which is also filtered out of the kidneys) to make urine (pee).
As each kidney makes urine, the urine slides down a long tube called the ureter (say: yu-ree-ter) and collects in the bladder, a storage sac that holds the urine.
When the bladder is about halfway full, your body tells you to go to the bathroom.
When you pee, the urine goes from the bladder down another tube called the urethra (say: yu-ree-thruh) and out of your body.
The kidneys, the bladder, and their tubes are called the urinary system.

Here's a list of all of the parts of the urinary system:

the kidneys: filters that take the waste out of the blood and make urine
the ureters: tubes that carry the urine to the bladder
the bladder: a bag that collects the urine
the urethra: a tube that carries the urine out of the body
Keeping a Balance

The kidneys also balance the volume of fluids and minerals in the body.

This balance in the body is called homeostasis (say: hoh-mee-oh-stay-sus).
If you put all of the water that you take in on one side of a scale and all of the water your body gets rid of on the other side of a scale, the sides of the scale would balance.

Your body gets water when you drink it or other liquids.

You also get water from some foods, like fruits and vegetables.
Water leaves your body in several ways.

It comes out of your skin when you sweat, out of your mouth when you breathe, and out of your urethra in urine when you go to the bathroom.

There is also water in your bowel movements (poop).
When you feel thirsty, your brain is telling you to get more fluids to keep your body as balanced as possible.

If you don't have enough fluids in your body, the brain communicates with the kidneys by sending out a hormone that tells the kidneys to hold on to some fluids.

When you drink more, this hormone level goes down, and the kidneys will let go of more fluids.
You might notice that sometimes your urine is darker in color than other times.

Remember, urine is made up of water plus the waste that is filtered out of the blood.

If you don't take in a lot of fluids or if you're exercising and sweating a lot, your urine has less water in it and it appears darker.

If you're drinking lots of fluids, the extra fluid comes out in your urine, and it will be lighter.

What Else Do Kidneys Do?
Kidneys are always busy. Besides filtering the blood and balancing fluids every second during the day, the kidneys constantly react to hormones that the brain sends them. Kidneys even make some of their own hormones.

For example;

the kidneys produce a hormone that tells the body to make red blood cells.
Now you know what the kidneys do and how important they are.

Video: MAP OF MEDICINE

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:53:00 +0000

Video: Medicine for Kidney Problems

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:50:00 +0000

Video: Kidney Transplant Story

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:48:00 +0000

Video: Giving a Support

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:43:00 +0000

Video: Living Kidney donor

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:35:00 +0000

Video : Seeking a Kidney Donors

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:30:00 +0000

Video: Kidney Swapping Couples

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:24:00 +0000

Video: Kidney Transplant

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:22:00 +0000

Video: Kidney Transplant Update

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:18:00 +0000

VIDEO: Kidney Transplant Drugs

noreply@blogger.com (Bryan) — Tue, 25 Nov 2008 01:13:00 +0000