Application

Hepatitis

Hepatitis is an inflammation of the liver caused by viral infection, or, more rarely, from reaction to a drug, alcoholism, or autoimmunity. There are several types of hepatitis.

Liver inflammation Causes Distinct Symptoms

Hepatitis A is one of the least severe forms of this common illness. For the first few days, symptoms include mild headache, low fever, fatigue, lack of appetite, nausea and vomiting, and sometimes stiff joints. By the end of the first week, more distinctive symptoms arise, including a rash, pain in the upper right quadrant of the abdomen, dark and foamy urine, and pale feces. The skin and sclera of the eyes begin to turn yellow from accumulating bile pigments (jaundice). Great fatigue may continue for two or three weeks, and then gradually the person begins to feel better.

At the other end of the hepatitis spectrum is fulminant hepatitis, which is rare and can be caused by any of several viruses. Symptoms start suddenly and severely, and behavior and personality may change. Without medical attention, the condition progresses to kidney and liver failure, or coma.

Hepatitis B produces chronic symptoms that persist for more than six months. Perhaps as many as 300 million people worldwide are carriers of hepatitis B. They do not have symptoms but can infect others.

Five percent of such carriers eventually develop liver cancer.

An Alphabet of Viral Causes

Several types of viruses can cause hepatitis. Viral types are distinguished by the route of infection and by biochemical differences, such as gene sequences and surface proteins.

At the beginning of the twentieth century, before investigators knew how to study viruses, two types of hepatitis were distinguished epidemiologically. So-called "infectious hepatitis," which was transmitted from person to person, was later attributed to the hepatitis A virus. "Serum hepatitis" was transmitted by blood and was later found to be caused by the hepatitis B virus. Hepatitis A often arose from food handlers who did not properly wash after using the bathroom, establishing a fecal-oral route of transmission. Hepatitis B was more often passed sexually.

By the mid-1970s, technology enabled physicians to identify either hepatitis A or hepatitis B virus. But then a problem arose: many cases of what appeared to be hepatitis were not caused by either of the known viral types. These were called "non-A non-B" hepatitis — which just meant that researchers did not know what caused them. Then in the 1980s, the "non-A

and non-B" viruses began to be identified.

The hepatitis C virus causes more than 90% of cases of hepatitis that arise after a person receives a blood transfusion. Hepatitis D is bloodborne, usually associated with blood transfusion and intravenous drug use, and occurs in people already infected with hepatitis B. It kills about 20% of the people it infects. Hepatitis E infection is more common in developing nations, where it often severely affects pregnant women.

But some cases of hepatitis still could not be linked to a specific virus, and these became known as "non-A-E" hepatitis. Since 1994, two new hepatitis viruses have been identified and associated with some of the non-A-E cases. Very little is known about the hepatitis F virus, but it can pass from human feces to infect other primates. Hepatitis G is very rare, but seems to account for a significant percentage of cases of the fulminant form of hepatitis. However, in people with healthy immune systems, it produces symptoms so mild that they may not even be noticed.

Because hepatitis is most often caused by a virus, treatment with antibiotic drugs, which target bacteria, are ineffective. Often the person must simply endure the symptoms. Hepatitis C, however, sometimes responds to a form of interferon, an immune system biochemical. ■

Figure 17.31

Radiograph of a gallbladder that contains gallstones (arrow).

Figure 17.31

Radiograph of a gallbladder that contains gallstones (arrow).

(see fig. 17.28 and reference plate 59). The gallbladder has a capacity of 30-50 milliliters, is lined with columnar epithelial cells, and has a strong muscular layer in its wall. It stores bile between meals, concentrates bile by reabsorbing water, and releases bile into the duodenum when stimulated by cholecystokinin from the small intestine.

The common bile duct is formed by the union of the common hepatic and cystic ducts. It leads to the duodenum, where the hepatopancreatic sphincter muscle guards its exit (see fig. 17.24). This sphincter normally remains contracted, so that bile collects in the common bile duct and backs up into the cystic duct. When this happens, the bile flows into the gallbladder, where it is stored.

Bile salts, bile pigments, and cholesterol become increasingly concentrated as the gallbladder lining reab-sorbs some water and electrolytes. Although the cholesterol normally remains in solution, under certain conditions it may precipitate and form solid crystals. If cholesterol continues to come out of solution, the crystals enlarge, forming gallstones (fig. 17.31). This may happen if the bile is too concentrated, hepatic cells secrete too much cholesterol, or the gallbladder is inflamed (cholecystitis). Gallstones in the bile duct may block the flow of bile, causing obstructive jaundice and considerable pain. Clinical Application 17.4 discusses disorders of the gallbladder.

A famous photograph of former U.S. President Lyndon Johnson depicts him displaying the 8-inch scar on his abdomen from where his gallbladder was removed to treat gallstones. Today, many such procedures — called cholecystectomies — are performed using a laser, which leaves four tiny cuts, each a quarter to a half inch long. Recovery from the laser procedure is much faster than from traditional surgery.

Get Rid of Gallstones Naturally

Get Rid of Gallstones Naturally

One of the main home remedies that you need to follow to prevent gallstones is a healthy lifestyle. You need to maintain a healthy body weight to prevent gallstones. The following are the best home remedies that will help you to treat and prevent gallstones.

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