Monday, April 23, 2012


We have crossed a enormous a milestone in the grassland of technology and require further than this. We have widened approximately by the same token in every technology for instance machines, gadgets or computers and so on. Amongst them car is one of the technology which is a means of transportation. Car is a four wheeled vehicle used for transporting passengers. The first working steam-powered vehicle was likely to have been designed by Ferdinand Verbiest around 1672.Nicolas-Joseph Cugnot is credited with construction the first self-propelled mechanical vehicle in about 1769; the load of a car influence fuel burning up and performance with additional load ensuing in amplified fuel burning up and decrease performance. The majority cars are premeditated to bear compound occupant, regularly with four or five seats. We know the fact that world population is increasing so there is a huge chance of accidents due to traffic mostly and in order to low various system has been made in car.  And so, most people are doing car insurance. In order to know more about vehicle insurance link this below
vehicle insurance
Most cars in exercise today are propelling by an internal combustion engine. Numerous safety skin textures are put into high technology cars. The first safety feature is push-button aid. With the push of a button, you can get travel information, roadside support, and emergency aid with the Tele Aid System. It connect you to a 24-hour center that can path your vehicle’s locality through GPS. In a misfortune, the scheme will automatically call for aid and transmit your location, while center personnel direct emergency help to the vehicle. This will also easily and quickly locate your car if it is stolen. The next technologies which will make the roads safer are Thermal Imaging and Night Vision to see through fog and at night.. This heads-up-display, or HUD, then projects the image onto the windshield. This Night Vision gives the driver a view of the road ahead and picks up any heat-emitting objects.

Saturday, April 14, 2012


An ulcer may be superficial, or it may extend into the deeper layer of the skin or other underlying tissue. An ulcer has a depressed floor or crater surrounded by sharply defined edges that are sometimes elevated above the level of the adjoining surface. The main symptom of an ulcer is pain. The main causes of ulcers are infection, faulty blood circulation, nerve damage, and trauma, nutritional disturbances including thiamine or other vitamin deficiencies, and cancer. Such bacterial infections as tuberculosis or syphilis can cause ulcers on any surface of the body. Any infection under the skin, such as a boil or carbuncle, may break through the surface and form an inflammatory ulcer. The ulcers on the legs of persons with varicose veins are caused by the slow circulation of the blood in the skin. Diabetics may sustain ulcers on their feet or toes after losing sensation in those areas due to nervous-system damage. A peptic ulcer is an ulcer that occurs in the stomach or the first segment of the duodenum, parts of the intestinal tract that are bathed by gastric juice. Ulcers can also result from burns, electric burns, and frostbite. When an ulcer of the skin has been present for at least one month or is hard to the touch, the possibility of cancer must be considered. The probability of cancer is increased if the patient is past middle age. Ulcers on the border of the lower lip in elderly men are frequently cancers. Such cancers must be recognized and treated early before they spread and become inoperable. By contrast, superficial ulcers on the lips, known as cold sores, are caused by a virus and are not serious. Ulcers in the mouth and throat are frequently caused by infection but are sometimes cancerous, especially in older persons. Cancerous ulcers may also occur in the stomach, small or large intestine and rectum.


Leprosy is an infectious disease that affects the skin, the peripheral nerve, and the mucous membranes of the nose, throat, and eyes. It is caused by the leprosy bacillus, Mycobacterium leprae. Destruction of the peripheral nerves by the bacillus leads to a loss of sensation, which, together with progressive tissue degeneration, may result in the extremities' becoming deformed and eroded. In almost all cultures throughout history, leprosy has aroused dread and loathing about the prospect of incurable disease and a lifetime of progressive disfigurement. At one time “lepers,” as those with the disease were long called, were ostracized as unclean and were gathered into isolated “leper colonies” in order to keep them out of sight, to control their contagiousness, and to offer them what little treatment was available. In reality, the leprosy bacillus is not highly infectious, in most cases passing from one person to another only after prolonged and close contact (as, for instance, among family members). In addition, thanks to modern therapy with a number of effective drugs, the disease is now entirely curable, and the term leper, connoting somebody who has had and always will have the disease, thus no longer has meaning and in fact is considered to be offensive because of the social stigma long associated with the disease. Health care officials today do not consider a cured former leprosy patient to be any more “leprous” than a cured former cancer patient is “cancerous.”Despite modern therapy, leprosy is still a persistent disease in many parts of the world, and in many cases the disfigurement and disability caused by the infection cannot be reversed. Millions of people alive today either have or have had leprosy, and more than 500,000 currently require drug treatment. Some 600,000 new cases arise every year. The disease has almost disappeared from most temperate countries, but it is still common in Asia, Africa, Central and South America, and the Pacific Islands. India has the largest number of cases, with more than 60 percent of the world's infected persons. The route of transmission of leprosy remained a matter of debate. The prevailing opinion for many years was that the illness spread via prolonged skin-to-skin contact. Then the theory of respiratory transmission became popular; it posited that the bacillus entered the human body through the lining of the nose. For a time scientists even entertained the possibility of transmission by insect bites. In the late 20th century, experiments with a mouse model of the disease showed that transmission is indeed possible through the intact lining of the nose and through breaks in the skin but not via the mouth, lungs, or digestive tract or through unbroken skin. And, although leprosy can be produced in mice by exposing them to the bacillus, the disease cannot be transmitted from an infected to an uninfected mouse. The current treatment of leprosy is extremely effective, halting the progress of the disease. The bacilli can be killed rapidly and multidrug therapy the use of two or more antileprosy drugs in combination prevents the development of drug-resistant strains. Indeed, multidrug therapy a practice widely adopted in the treatment of tuberculosis and AIDS was first proposed after scientists observed that some cases of leprosy were becoming resistant to sulfones, the earliest class of antileprosy drugs. A multidrug regimen developed by the World Health Organization (WHO) is the current standard of treatment. For patients with localized forms of leprosy and relatively few leprosy bacilli in their bodies, two drugs, dapsone and rifampicin, are given for a total of six months. For patients with more widespread disease and relatively large numbers of bacilli, three drugs dapsone, clofazimine, and rifampicin are given for 24 months. Most patients are able to tolerate the drugs well, but a few experience undesirable side effects or even exacerbations of the symptoms. Relapses, in general, are rare, occurring in less than 1 per 1,000 treated patients.


 Tuberculosis is an infectious disease caused by tubercle bacillus, Mycobacterium bacillus. In most forms of the disease, the bacillus spreads slowly and widely in the lungs, causing the formation of hard nodules (tubercles) or large, cheese like masses that break down the respiratory tissues and form cavities in the lungs. Blood vessels also can be eroded by the advancing disease, causing the infected person to cough up bright red blood. The tubercle bacillus is a small, rod-shaped bacterium that is extremely hardy; it can survive for months in a state of dryness and can also resist the action of mild disinfectants. Infection spreads primarily by the respiratory route directly from an infected person who discharges live bacilli into the air. Minute droplets ejected by sneezing, coughing, and even talking can contain hundreds of tubercle bacilli that may be inhaled by a healthy person. There the bacilli become trapped in the tissues of the body, are surrounded by immune cells, and finally are sealed up in hard, nodular tubercles. A tubercle usually consists of a center of dead cells and tissues, cheese like in appearance, in which can be found many bacilli. This centre is surrounded by radially arranged phagocytic cells and a periphery containing connective tissue cells. The tubercle thus forms as a result of the body's defensive reaction to the bacilli. Individual tubercles are microscopic in size, but most of the visible manifestations of tuberculosis, from barely visible nodules to large tuberculosis masses, are conglomerations of tubercles. The diagnosis of pulmonary tuberculosis depends on finding tubercle bacilli in the sputum, in the urine, in gastric washings, or in the cerebrospinal fluid. The primary method used to confirm the presence of bacilli is a sputum smear, in which a sputum specimen is smeared onto a slide, stained with a compound that penetrates the organism's cell wall, and examined under a microscope. If bacilli are present, the sputum specimen is cultured on a special medium to determine whether the bacilli are M. tuberculosis. An X-ray of the lungs may show typical shadows caused by tubercular nodules or lesions. The prevention of tuberculosis depends on good hygienic and nutritional conditions and on the identification of infected patients and their early treatment. A vaccine, known as BCG vaccine, is composed of specially weakened tubercle bacilli. Injected into the skin, it causes a local reaction, which confers some immunity to infection by M. tuberculosis for several years. It has been widely used in some countries with success; its use in young children in particular has helped to control infection in the developing world. The main hope of ultimate control, however, lies in preventing exposure to infection, and this means treating infectious patients quickly, possibly in isolation until they are noninfectious. In many developed countries, individuals at risk for tuberculosis, such as health care workers, are regularly given a skin test to show whether they have had a primary infection with the bacillus. Today, the treatment of tuberculosis consists of drug therapy and methods to prevent the spread of infectious bacilli.

Swine Flu

Swine flu is viral respiratory disease mainly of poultry and certain other bird species, including migratory water birds, some imported pet birds, and ostriches, that can be transmitted directly to humans. The first known cases in humans were reported in 1997, when an outbreak in poultry in Hong Kong led to severe illness in 18 people, a third of whom died. Symptoms of bird flu in humans resemble those of the human variety of influenza and include fever, sore throat, cough, headache, and muscle aches, which appear following an incubation period of several days. . Between 2003 and late 2005, outbreaks of the most deadly variety of bird flu occurred among poultry in Cambodia, China, Indonesia, Japan, Kazakhstan, Laos, Malaysia, Romania, Russia, South Korea, Thailand, Turkey, and Vietnam. Hundreds of millions of birds in those countries died from the disease or were killed in attempts to control the epidemics. From 2003 through January 2009, 397 people were reported to have been infected with bird flu, and slightly less than two-thirds of them died. The majority of human infections and deaths occurred in China, Egypt, Indonesia, Thailand, and Vietnam. Poultry-associated human infection with a less severe form of the disease was reported in the Netherlands. Bird flu in avian species occurs in two forms, one mild and the other highly virulent and contagious; the latter form has been termed fowl plague. Mutation of the virus causing the mild form is believed to have given rise to the virus causing the severe form. The infectious agents of bird flu are any of several subtypes of type A orthomyxovirus. Other subtypes of this virus are responsible for most cases of human influenza and for the great influenza pandemics of the past Genetic analysis suggests that the influenza A subtypes that afflict mainly no avian animals, including humans, pigs, whales, and horses, derive at least partially from bird flu subtypes. All the subtypes are distinguished on the basis of variations in two proteins found on the surface of the viral particle hemagglutinin (H) and neuraminidase (N). The 1997 bird flu outbreak in Hong Kong was found to be caused byH5N1. This subtype, first identified in terns in South Africa in 1961, has been responsible for nearly all laboratory-confirmed bird flu infections in humans and for the most devastating outbreaks in poultry. Other bird flu subtypes recognized to cause disease in birds and humans are H7N2, H7N3, H7N7, and H9N2. The H5N1 virus, however, appears resistant to at least two of the drugs, amantadine and rimantadine.


Typhoid is an acute infectious disease caused by a specific serotype of the bacterium Salmonella typhi. The bacterium usually enters the body through the mouth by the ingestion of contaminated food or water, penetrates the intestinal wall, and multiplies in lymphoid tissue. After an average 10–14-day incubation period, the early symptoms of typhoid appear: headache, malaise, generalized aching, fever, and restlessness that may interfere with sleep. There may be loss of appetite, nosebleeds, cough, and diarrhea or constipation. Persistent fever develops and gradually rises, usually in a stepwise fashion, reaching a peak of 39 or 40 °C (103 or 104 °F) after 7–10 days and continuing with only slight morning remissions for another 10–14 days. During about the second week of fever, when typhoid bacilli are present in great numbers in the bloodstream, a rash of small, rose-colored spots appears on the trunk, lasts four or five days, and then fades away. The lymph follicle along the intestinal wall in which the typhoid bacilli have multiplied become inflamed and necrotic and may slough off, leaving ulcers in the walls of the intestine. The dead fragments of intestinal tissue may erode blood vessels, causing hemorrhage, or they may perforate the intestinal wall, allowing the intestine's contents to enter the peritoneal cavity. Other complications can include acute inflammation of the gallbladder and heart failures with a continued high fever the symptoms usually increase in intensity and mental confusion may appear. By the end of the third week the patient is emaciated, abdominal symptoms are marked, and mental disturbance is prominent. In favorable cases, during about the beginning of the fourth week, the fever begins to decline, the symptoms begin to abate, and the temperature gradually returns to normal. If untreated, typhoid fever proves fatal in up to 25 percent of all cases. Patients with such diseases as cancer or sickle cell anemia are particularly prone to develop serious and prolonged infection with Salmonella. Most major typhoid fever has been caused by the pollution of public water supplies. Food and milk may be contaminated, however, by the disease who is employed in handling and processing them; by flies; or by the use of polluted water for cleaning purposes. Shellfish, particularly oysters, grown in polluted water and fresh vegetables grown on soil fertilized or contaminated by untreated sewage are possible causes. The prevention of typhoid fever depends mainly on proper sewage treatment, filtration and chlorination of water, and the exclusion of carriers from employment in food industries and restaurants. In the early part of the 20th century, prophylactic vaccination using killed typhoid organisms was introduced, mainly in military forces and institutions, and contributed to a lowering of the incidence of the disease. Diagnosis of typhoid fever is made by blood culture, stool culture, and serological testing. The treatment of typhoid fever is with antibiotics, particularly Chloramphenicol begins to lower the patient's fever within three or four days after beginning therapy, and there is progressive improvement thereafter. The drug treatment is continued for several weeks in order to prevent relapses.


 Jaundice is due to excess accumulation of bile pigments in the bloodstream and bodily tissues that causes a yellow to orange and sometimes even greenish discoloration of the skin, the whites of the eyes, and the mucous membranes. Jaundice is best seen in natural daylight and may not be apparent under artificial lighting. The degree of coloration depends on the concentration of bile pigment (bilirubin) in the blood, its rate of tissue diffusion, and the absorption and binding of bilirubin by the tissue. Bilirubin enters the tissue fluids and is absorbed more readily at sites of inflammation and edema (abnormal accumulation of fluids in the tissues).The most common mechanisms causing jaundice are an overproduction of bile by the liver, so that more is produced than can be readily excreted; congenital defects, which may impair the removal of bile pigments or cause overproduction; inability of liver cells to remove bile pigments from the blood because of liver disease; leakage of bilirubin removed by the liver back into the bloodstream (regurgitation); or obstruction of the bile ducts. A health newborn may develop jaundice because the liver has not fully matured. This type of jaundice usually subsides within a few weeks when the liver begins to function properly. Jaundice is classified as unconjugated, hepatocellular, or cholestatic. The first type, unconguate, or hemolytic, jaundice, appears when the amount of bilirubin produced from hemoglobin by the destruction of red blood cells or muscle tissue exceeds the normal capacity of the liver to transport it or when the ability of the liver to conjugate normal amounts of bilirubin into bilirubin diglucoronide is significantly reduced by inadequate intracellular transport or enzyme systems. The second type, hepatocelluar, arises when liver cells are damaged so severely that their ability to transport bilirubin diglucoronide into the biliary system is reduced, allowing some of the yellow pigment to regurgitate into the bloodstream. The third type, cholestatic, or obstructive, jaundice, occurs when essentially normal liver cells are unable to transport bilirubin either through the hepatic-bile capillary membrane, because of damage in that area, or through the biliary tract, because of anatomical obstructions such as gallstones or cancer. Some of the various diseases that can cause jaundice are hemolytic anemia, congestion in the circulatory system, pneumonia, congenital liver abnormalities, degeneration of the liver cells by poisons or infectious organisms, scarring of the liver tissue (cirrhosis), and obstructions or tumours in the liver, bile ducts, and the head of the pancreas. In most cases, jaundice is an important symptom of some inherent bodily disturbance, but aside from the neonatal period the retention of bilirubin itself does not usually cause any greater damage than skin discoloration that lasts until the systemic problem is corrected.

Hypotension and Hypertension

Force originating in the pumping action of the heart, exerted by the blood against the walls of the blood vessels; the stretching of the vessels in response to this force and their subsequent contraction are important in maintaining blood flow through the vascular system. In human beings, blood pressure is usually measured indirectly over the brachial or femoral artery: the highest (systolic) pressure, normally about 120 (100 to 140) millimeters of mercury, occurs during contraction of the ventricles; the lowest (diastolic) pressure, normally about 80 (60 to 100) millimeters, occurs during ventricular relaxation. Blood pressure in the capillaries is usually about 20 to 30 millimeters, while the pressure in the large veins may become negative (lower than atmospheric pressure). Hypertension occurs when the body's smaller blood vessels (the arterioles) narrow, causing the blood to exert excessive pressure against the vessel walls and forcing the heart to work harder to maintain the pressure. Although the heart and blood vessels can tolerate increased blood pressure for months and even years, eventually the heart may enlarge (a condition called hypertrophy) and be weakened to the point of failure. Injury to blood vessels in the kidneys, brain, and eyes also may occur. Extensive bleeding is an obvious cause of reduced blood volume that leads to hypotension. There are other possible causes. A person who has suffered an extensive burn loses blood plasma blood minus the red and white blood cells and the platelets. Blood volume is reduced in a number of conditions involving loss of salt and water from the tissues as in excessive sweating and diarrhea and its replacement with water from the blood. Loss of water from the blood to the tissues may result from exposure to cold temperatures. Also, a person who remains standing for as long as one-half hour may temporarily lose as much as 15 percent of the blood water into the tissues of the legs.


Group of more than 100 distinct diseases characterized by the uncontrolled growth of abnormal cells in the body. Cancer affects one in every three persons born in developed countries and is a major cause of sickness and death throughout the world. Though it has been known since antiquity, significant improvements in cancer treatment have been made since the middle of the 20th century, mainly through a combination of timely and accurate diagnosis, selective surgery, radiation therapy, and chemotherapeutic drugs. Such advances actually have brought about a decrease in cancer deaths. The billions of cells that make up a tumor are descended from a single cell that has found a way to escape the normal controls of its growth. This loss of control is caused by damage of the genetic material in the cell, specifically the long, coiled chains of deoxyribonucleic acid (DNA) found in the chromosomes. Such damage can arise during cell division, be induced by environmental agents, or be inherited. Regardless of how the damage is caused, genetic changes and the abnormal growth pattern that they promote are passed on to a cell's progeny (its daughter cells) as the cell divides. Important determinant of the way a tumor will grow how fast it will give rise to clinical symptoms, and how early it may be diagnosed. For example, a tumor of the skin located on the face is usually detected very early, whereas a sarcoma located in the deep soft tissues of the abdomen can grow to weigh 2 kilograms before it causes much of a disturbance. The site of origin of a tumor also determines the signs and symptoms of disease that the individual will experience and influences possible therapeutic options. The most common tumor sites in females are the breast, lung, and colon. In men the most frequently affected sites are the prostate, lung, and colon. Cancer is to a great degree a disease of the elderly, and age is thus a very important factor in cancer development. However, individuals of any age, including very young children, can be stricken with the disease. Benign and malignant tumors produce a number of effects in an individual that vary depending on the location of the tumor, the tumor’s functional activity, and any acute events that occur as the tumor mass grows and evolves. Metastatic tumors (those that result from the spread of the primary tumor) can produce the same consequences. A tumor affects normal bodily functions by compressing, invading, and destroying normal tissues and also by producing substances that circulate in the bloodstream .In order for cancer to be diagnosed as early as possible, an individual should be aware of symptoms that may be related to the disease. The standard diagnostic workup begins with a detailed clinical history of the person. A complete physical examination, including laboratory tests such as a complete blood count and a urinalysis, is made. Diagnostic imaging using X-ray, ultrasound, computed tomography (CT) scans, or magnetic resonance imaging(MRI) may be essential, and radioisotopes can be used to visualize certain organs or regions of the body.


There are seven known hepatitis viruses, which are labeled A, B, C, D, E, F, and G. Hepatitis A, E, and F viruses are transmitted through the ingestion of contaminated food or water (called the fecal-oral route); the spread of these agents is aggravated by crowded conditions and poor sanitation. The B, C, D, and E viruses are transmitted mainly by blood or bodily fluids; sexual contact or exposure to contaminated blood are common modes of transmission The signs and symptoms of acute viral hepatitis result from damage to the liver and are similar regardless of the hepatitis virus responsible. Patients may experience a flulike illness, and general symptoms include nausea, vomiting, abdominal pain, fever, fatigue, loss of appetite, and, less commonly, rash and joint pain. The onset of hepatitis A usually occurs 15 to 45 days after exposure to the virus, and some infected individuals, especially children, exhibit no clinical manifestations. In the majority of cases, no special treatment other than bed rest is required; most recover fully from the disease. Hepatitis A does not give rise to chronic hepatitis. The severity of the disease can be reduced if the affected individual is injected within two weeks of exposure with immune serum globulin obtained from persons exposed to hepatitis A virus. This approach, called passive immunization, is effective because the serum contains antibodies against hepatitis A virus. Hepatitis B may occur as an acute disease, or, in about 5 to 10 percent of cases, the illness may become chronic and lead to permanent liver damage. Symptoms usually appear from 40 days to 6 months after exposure to the hepatitis B. Those persons at greatest risk for contracting hepatitis B include intravenous drug users, sexual partners of individuals with the disease, health care workers who are not adequately immunized, and recipients of organ transplants or blood transfusions. A safe and effective vaccine against HBV is available and provides protection for at least five years. Passive immunization with Symptoms of hepatitis C usually appears within six to nine weeks after exposure. Hepatitis C virus appears to be transmitted in a manner similar to hepatitis B virus. Hepatitis C has a greater propensity than hepatitis B to develop into chronic liver disease. Alcoholics who are infected with hepatitis C are more prone to develop cirrhosis. Infection with hepatitis D virus may occur at the same time infection with hepatitis B virus occurs, or hepatitis D virus may infect a person already infected with hepatitis B virus. The latter situation appears to give rise to a more serious condition, leading to cirrhosis or chronic liver disease. Alpha interferon is the only treatment for hepatitis D virus infection. Preventing infection with hepatitis B virus also prevents hepatitis D virus infection. Hepatitis E virus is transmitted in the same manner as hepatitis B virus, and it, too, only causes acute infection. However, the effects of infection with hepatitis E virus are more severe than those caused by hepatitis A virus, and death is more common. The risk of acute liver failure from infection with hepatitis E virus is especially great for pregnant women. In less-developed countries, including Mexico, India, and those in Africa, hepatitis E virus is responsible for widespread epidemics of hepatitis that occur as a result of ingestion of contaminated water or food enteric transmission.


HIV has been found in Chimpanzees in western equatorial Africa. This virus, known as simian immunodeficiency virus (SIV), does not readily cause disease in chimpanzees. However, AIDS is a Zoonosis, an infection that is shared by humans and lower vertebrate animals. The practice of hunting, butchering, and eating the meat of chimpanzees may have allowed transmission of the virus to humans, probably in the late 19th century or early 20th century. Genetic studies of a pandemic strain of HIV, known as HIV-1 group M, have indicated that the virus emerged between 1884 and 1924 in central and western Africa. Researchers estimate that this strain of the virus began spreading throughout these areas in the late 1950s. Later, in the mid-1960s, an evolved strain called HIV-1 group M subtype B spread from Africa to Haiti. In Haiti this subtype acquired unique characteristics, presumably through the process of genetic recombination. Sometime between 1969 and 1972, the virus migrated from Haiti to the United States. The virus spread within the United States for about a decade before it was discovered in the early 1980s. The worldwide spread of HIV-1 was likely facilitated by several factors, including increasing urbanization and long-distance travel in Africa, international travel, changing sexual mores, and intravenous drug use. In 1981 investigators in New York and California reported the first official case of AIDS. Initially, most cases of AIDS in the United States were diagnosed in homosexual men, who contracted the virus primarily through sexual contact, and in intravenous drug users, who became infected mainly by sharing contaminated hypodermic needles HIV is transmitted by the direct transfer of bodily fluids, such as blood and blood products, semen and other genital secretions, or breast milk, from an infected person to an uninfected person. The primary means of transmission worldwide is sexual contact with an infected individual. HIV frequently is spread among intravenous drug users who share needles or syringes. Prior to the development of screening procedures and heat-treating techniques that destroy HIV in blood products, transmission also occurred through contaminated blood products; many people with hemophilia contracted HIV in this way. Today the risk of contracting HIV from a blood transfusion is extremely small. In rare cases transmission to health care workers may occur by an accidental stick with a needle used to obtain blood from an infected person Tests for the disease check for antibodies to HIV, which appear from four weeks to six months after exposure. The most common test for HIV is the enzyme linked immunosorbent assay (ELISA). If the result is positive, the test is repeated on the same blood sample. Another positive result is confirmed using a more specific test such as the Western blot. A problem with ELISA is that it produces false positive results in people who have been exposed to parasitic diseases such as malaria; this is particularly troublesome in Africa, where both AIDS and malaria are rampant As with any epidemic for which there is no cure, tragedy shadows the disease's advance The United Nations designated December 1 as World Aids Day.