Aspirin

-
Aspirin, synthetic chemical compound, acetylsalicylic acid. It is made from salicylic acid, found in the bark of the willow tree, which was used by the ancient Greeks and Native Americans, among others, to counter fever and pain. Salicylic acid is bitter, however, and irritates the stomach. The German chemist Felix Hoffman synthesized the acetyl derivative of salicylic acid in 1893 in response to the urging of his father, who took salicylic acid for rheumatism. Aspirin is currently the first-choice drug for fever, mild to moderate pain, and inflammation due to arthritis or injury. It is a more effective analgesic than codeine. Aspirin causes insignificant gastrointestinal bleeding that can over time, however, cause iron deficiency; gastric ulcers may also occur with long-term use. Complications can be avoided by using enteric-coated aspirin, which does not dissolve until reaching the intestine. Aspirin should not be given to children who have chicken pox or influenza, because it increases the risk of contracting the rare and frequently fatal Reye's syndrome, a disease of the brain and some abdominal organs.

Aspirin is thought to act by interfering with synthesis of prostaglandins, which are implicated in inflammation and fever. Studies of aspirin's anticlotting activities suggest that half an aspirin tablet per day may reduce the risk of heart attack and stroke in some persons.

Comments

Post a Comment

Popular posts from this blog

Cream, Butter, and Ice Cream

-
. In order for a product to be labeled as cream, it must contain 18 percent milk fat or more. Light whipping cream must contain at least 30 percent fat, and 36 percent fat is the minimum fat content for heavy whipping cream. Half-and-half, an equal mixture of both milk and cream, must have at least 10.5 percent fat. The various grades of cream are valued for their smooth, thick texture. They are often used in cooking instead of milk, because they are less likely to form a skin when heated and can be whipped into a stiff foam. When chilled cream is churned gently, the fat globules gather together to form butter, leaving buttermilk as the by-product. Butter contains at least 82.5 percent fat. In the past, before the advent of widespread refrigeration, salt was added to butter to retard bacterial spoilage; now salt is added mainly for flavor. Ice cream, a popular frozen dessert, is made of milk, cream, sugar, and flavoring. The mixture is slowly beaten while chilled until it is partially
Read more

Deoxyribonucleic Acid

-
Deoxyribonucleic Acid (DNA), genetic material of all cellular organisms and most viruses. DNA carries the information needed to direct protein synthesis and replication. Protein synthesis is the production of the proteins needed by the cell or virus for its activities and development. Replication is the process by which DNA copies itself for each descendant cell or virus, passing on the information needed for protein synthesis. In most cellular organisms, DNA is organized on chromosomes located in the nucleus of the cell .
Read more

How HIV Causes Infections

-
HIV transmission occurs when a person is exposed to body fluids infected with the virus, such as blood, semen, vaginal secretions, and breast milk. The primary modes of HIV transmission are (1) sexual relations with an infected person (see Sexually Transmitted Infections ); (2) sharing hypodermic needles or accidental pricking by a needle contaminated with infected blood; and (3) transfer of the virus from an infected mother to her baby during pregnancy, childbirth, or through breast-feeding. When HIV enters the body, it infects lymphocytes, which are a type of white blood cell in the immune system . HIV uses its glycoproteins to attach itself to receptors on the surface of a lymphocyte. The outer envelope of HIV then fuses with the lymphocyte, enabling the HIV capsid to enter the lymphocyte itself. HIV commandeers the genetic material of the lymphocyte, instructing the cell to replicate more viruses. The newly formed viruses break free from the host, destroying the cell in the process
Read more