European Stars And Stripes (Newspaper) - February 28, 1989, Darmstadt, Hesse Trying to blocks Eric processes by Harold m. Schmeck or. New York times buoyed by a Rush of research findings about the development of allergic reactions at the molecular level scientists Are now attempting to devise new ways to Block allergies before they can even begin. Scientists have recently identified the Complete structures of important cell receptors and gained new insights into the chemistry of the immune reactions that Are crucial in modifying the allergic response. The new knowledge is allowing scientists to explore treatments that May Block allergic processes at Early stages instead of simply coping piecemeal with the debilitating symptoms they cause. Researchers Are already testing drugs intended to halt or modify the allergic process Early in its development. Their goal is the development of better treatments and prevention of symptoms for the millions of americans afflicted with allergies. Among them Are Hay fever Many cases of asthma particularly in children reactions to certain drugs or foods As Well As illnesses that seem much like the common cold. We Are beginning to understand the biology and regulation of the cells that cause the clinical problem said or. K. Frank Austen of Harvard medical school an authority on allergic diseases. Scientists believe allergy is fundamentally a harmful mobilization of. Body processes that evolved to attack and destroy parasites. The main cells involved in the mobilization Are Mast cells and eosinophils. They originate in the Bone marrow Migrate to tissues like the mucous membranes of the air passages from nose to lungs As Well As the digestive and reproductive tracts. They contain granules filled with substances that can have powerful destructive effects when released abnormally in the body s allergic response. In my judgment there is a Renaissance in allergy said or. Gerald j. Gleich of the Mayo medical school Mayo clinic and foundation in Rochester minn., who has contributed much to the understanding of the functions of eosinophils. Just Why the defensive process goes astray is not known but an Early stage begins when certain antibodies called Immunoglobulin a or Ige that Are anchored to Mast cells come in Contact with a substance the allergen that provokes the allergic reaction. The Mast cells May attract eosinophils and both May release the destructive substances from their granules. The process can cause airways to constrict and blood vessels to dilate and become Leaky and can prompt the production of mucus. Until now therapy has been limited to countering these effects. For example antihistamines counter histamine one of the destructive substances. But advances in molecular and cell biology have Given scientists powerful new tools. Gleich has Analysed the contents of Eosinophil granules in great detail. In one set of experiments described last year in Hospital practice Magazine Gleich and his colleagues tested the effects of major Basic protein which constitutes most of the protein in Eosinophil granules. The scientists exposed tissues of animal airways to the protein and found changes much like those seen in asthma patients. Interior surface cells of the bronchial passages were destroyed and the airways became hyper reactive to outside stimuli. Gleich said the results suggested that intact bronchial passages produce a substance that tends to make the airways relax keeping them open when other influences would make them contract. His studies suggest that map released by improperly activated Eosinophil cells May Rob the airways of this defense setting the stage for asthma. In recent years scientists have discovered Many substances called Lymph Kines that Are produced by White blood cells and have multiple Only partially understood effects in the human body. Some of these substances May also to your health a sneeze in the making Ige receptor Ige binds Toast cell receptor Mast cells a Type of immune Ceil found in tissue and blood Are key to allergic reactions. When an allergy causing substance enters the body antibodies called Immunoglobulin e bind to it. These Ige antibodies also bind to Mast cells. When the linkage is Complete the Mast cells produce an explosive discharge of histamines and other substances that produce allergic symptoms. O 0 too of come into use against allergy. Antibodies designed to Block one such substance interleukin-5, have been shown to interfere with eosinophils1 destructive effects against parasites suggesting that such substances might be developed into anti allergy drugs. Much the same is True of another Lymph Okine interleukin 4. Antibodies that Block its action appear to shut off the production of the allergy related Ige antibodies. Scientists understand allergy much better than Ever before said Kallinen an expert on asthma and other allergic diseases at the National Institute of allergy and infectious diseases. The Institute is a major unit of the Nih. His current research is on the biology of the mucous membranes that line air passages from nose to lungs seeking to understand the details of How those not membranes act in asthma Hay fever and the common cold. I be been in this Field for almost 20 years and the difference is like night and Day said Kaliner. Austen chairman of the department of Rheuma ology and immunology of Brigham and women s Hospital in Boston said most of the current experimental drug strategies represent Only intermediate Steps against allergy. The future he believes will see strategies yet to be developed that will allow doctors to use drugs to regulate the numbers and activities of the Mast cells and eosinophils themselves. Austen thinks the future of allergy research and treatment is particularly Bright because the new tools of molecular and cell biology give scientists powerful new ways of studying the allergic process. Infected after having sex with an infected partner just once while others have not become infected even though they have had sex with an infected person repeatedly. The factors that appear to influence whether you become infected Are numerous including the Type of sex you have. Anal sex is believed far More risky than vaginal Intercourse for example. Or. Norman Hearst of the University of California san Francisco published one of the few attempts to calculate the risks. Hearst and his colleagues estimated the risk of someone s becoming infected with the aids virus from one sexual encounter with someone he knows for sure is not in a High risk group primarily a bisexual Man or intravenous drug user is about one in 5 million. That s about the same As getting killed in a car Accident every time you get in a car and drive 20 Miles said Hearst in a Telephone interview. That risk is really quite the problem is that Many people do not know their sexual partners Well enough to be 100 percent sure they Are not members of a High risk group he said. If an individual s sexual partner does belong to a High risk group the risk jumps to As High As one in 1,000 for a single sexual encounter according to Hearst s projections. That does t sound too High. But it is he said likening it to the risk of dying in a car Accident from passing on a Blind curve. It s a clearly risky thing that you May get away with Many times but sooner or later you won t get away with Hearst s estimations have come under criticism in part because they assume everyone infected is equally Likely to transmit the virus. But most researchers agree the risk to the average heterosexual is probably relatively Low right now because the virus has not yet spread far into the general heterosexual population. Most of those infected Are Gay men and intravenous drug users. Really the risk is quite Low compared to what people face everyday and Don t think about said Victor is Gruttola an assistant professor of Bio statistics at Harvard school of Public health in Cambridge mass. For Low risk behaviour like heterosexual Contact vaginal sex with a woman in the developed countries the risk appears to be very but experts Are concerned about keeping the viruses from proliferating through the heterosexual population. And even if the current risk is Low for most heterosexuals aids is a fatal disease with devastating consequences. You can liken this to playing the lottery. In a certain sense you win the lottery when you Don t get infected. But you have to win every time. If you lose once that s it said Edward Kaplan a researcher at Yale University in new Haven Conn. Tuesday february 28, 1989 the stars and stripes Page 17
