Tuesday, November 16, 2010

Cystic Fibrosis

Do you know what is meant by Cystic Fibrosis ???
now,, i'll explain.. what is meant by Cystic Fibrosis . ok .
happy reading :)

Cystic Fibrosis, incurable hereditary disorder that causes the body to secrete an abnormally thick, sticky mucus that clogs the pancreas and the lungs, leading to problems with breathing and digestion, infection, and ultimately, death. Three decades ago most babies born with cystic fibrosis died in early childhood, but advances in diagnosing and treating the disease have significantly improved its prognosis. Today more than 60 percent of babies born with cystic fibrosis reach adulthood, and further advances,, particularly in the field of gene therapy, may produce even better treatments in the coming years.

One of the most common fatal genetic disorders in the United States, cystic fibrosis occurs in about one in every 3,900 babies. About 1,000 new cases are diagnosed each year, usually before a child reaches three years of age. Approximately 30,000 American children and young adults have cystic fibrosis. The disease affects white people more often than black people: One in every 3,300 white babies is born with cystic fibrosis, but only one in every 15,300 black babies is born with the disease.

Cystic fibrosis is caused by a defect in the gene responsible for manufacturing cystic fibrosis transmembrane conductance regulator (CFTR),, a protein that controls the flow of chloride ions into and out of certain cells. In healthy people, CFTR forms a channel in the plasma membrane through which chloride ions enter and leave the cells lining the lungs, pancreas, sweat glands, and small intestine. In people with cystic fibrosis, malfunctioning (or absent) CFTR prevents chloride from entering or leaving cells, resulting in production of a thick, sticky mucus that clogs ducts or tubes in these organs. In the lungs, this mucus blocks airways and impedes natural infection-fighting mechanisms, eventually turning the body’s immune system against its own lung tissue. Similar blockage prevents crucial digestive enzymes produced in the pancreas from reaching the intestines, impairing the ability to break down certain foods. In healthy people most of the chloride in sweat is reabsorbed, but in people with cystic fibrosis, sweat glands cannot take up chloride ions, enabling excessive amounts of salt to escape in the sweat. :)

Cystic fibrosis is an autosomal recessive genetic disorder. This means that to have the disease, a child must inherit two copies of the defective gene, one from each parent. Many people carry a single cystic fibrosis gene, although they do not experience any significant health problems as a result; in the general population, approximately 1 in 31 Americans carries the gene. The disease can only occur in babies with two carrier parents. When both parents are carriers, they have a 25 percent chance with every pregnancy of passing two copies of the defective gene to their child. Prospective parents may elect to undergo genetic testing to determine if one or both of them carry the defective gene. :D

Researchers identified the gene responsible for cystic fibrosis in 1989. Since that time more than 200 different defects in the cystic fibrosis gene have been described, many of which produce cystic fibrosis in varying degrees of severity. Researchers also learned that two different gene defects—one from each parent—can combine to produce varying effects.

Depending on the disease’s severity, symptoms may be apparent soon after birth, or they may escape detection for months or years. In nearly 20 percent of all cases, the first symptom is meconium ileus, intestinal blockage in newborns. In other babies, the first evidence of cystic fibrosis is bulky stool, poor weight gain, flabby muscle tone, or slow growth, all products of low levels of digestive enzymes in the intestines. About half of all children with cystic fibrosis first see the doctor for coughing, wheezing, or respiratory tract infections. Teenagers with cystic fibrosis may grow slowly and enter puberty later than their peers. Cystic fibrosis often causes impaired reproductive function. About 98 percent of adult men who have cystic fibrosis produce little or no sperm, and females have decreased fertility and are more likely to experience complications during pregnancy and childbirth. Cystic fibrosis patients of all ages are prone to dehydration because they lose so much salt in their sweat. Infections, particularly in the lungs, plague people with cystic fibrosis throughout their lives. These chronic infections destroy lung tissue, a complication that ultimately takes the lives of most people with cystic fibrosis.

The earlier a diagnosis is made the better so that early treatment can slow the progression of lung damage caused by infection. Prenatal tests are available to determine if a baby will be born with cystic fibrosis. In newborns, blood tests indicating high levels of digestive enzymes suggest cystic fibrosis, but a certain diagnosis requires a sweat test to determine the amount of salt in the sweat. Sweat tests provide a valid diagnosis in babies over 24 hours old, and this test is also used to confirm diagnosis in older children and adults.

Cystic fibrosis remains incurable; existing treatments aim to relieve discomfort and delay the devastating and inevitable effects of the disease. Meconium ileus, the intestinal obstruction occurring in newborns, may require surgery. Patients with pancreatic blockage must take pancreatic enzymes with meals. Even with such enzymes, people with cystic fibrosis must consume adequate amounts of protein, vitamins, and higher-than-normal amounts of fat to ensure growth. Those with respiratory infections are treated with antibiotics, often in aerosol form. When inhaled, these medicated vapors fight infection and relieve constriction of the airways. Using a procedure called chest physical therapy or postural drainage, caregivers of people with cystic fibrosis repeatedly and vigorously pound on the patient’s back and chest to dislodge mucus obstructing the airways. Increasingly, cystic fibrosis patients with severe, irreparable lung damage turn to lung transplantation surgery (see Medical Transplantation). Although complications with transplantation surgery may pose problems for some patients, lung or combination heart and lung transplants provide nearly 80 percent of cystic fibrosis patients with severe lung damage an entirely new lease on life.

Although no cure has yet been found, cystic fibrosis presents one of the most promising areas of research in modern medicine. Scientists are investigating the use of gene therapy to introduce healthy copies of the CFTR gene into the cells of patients with cystic fibrosis. Scientists hope that once inside the cells, healthy copies of the gene will manufacture functional CFTR protein, permitting the flow of chloride into and out of cells in affected organs and restoring healthy function. Just one of many new treatment strategies under investigation, such research provides the cystic fibrosis community—scientists, patients, and families—with hope that more-effective treatments and possibly a cure may soon be discovered.

Organ affected by Cystic Fibrosis :
  • Sinuses : sinusitis (infection)
  • Lungs : thick, sticky mucus buildup, bacterial infection, and widened airways.
  • Skin : sweat glands produce salty sweat.
  • Liver : blocked biliary ducts.
  • Pancreas : blocked pancreatic ducts.
  • Intestines : cannot fully absorb nutrients. 
  • Reproductive organs : (male and female) complications.

the end ...
hopefully this article can be useful for you..
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