Diarrhea 7 Acute diarrhea can result from food poisoning, laxatives, alcohol . and some antacids but usually is caused by an acute infection with bacteria such as Staphylococcus aureus. In infants, acute diarrhea (急性腹泻) is usually self-limiting, and treatment consists primarily of preventing dehydration. Insomnia 8 Insomnia is a difficulty in falling asleep or the feeling that sleep is not refreshing. The treatment of insomnia involves establishing good sleep hygiene (睡眠卫生) : maintaining a consistent schedule of when to retire and awaken, setting a comfortable room temperature, and minimizing such disruptive stimuli as noise and light. Daily exercise is beneficial but should be avoided immediately before bedtime. When medication is required, physicians usually prescribe sleeping pills (安眠药) . BIOLOGICAL THERAPY Bone Marrow Transplantation 9 Bone marrow transplantation (骨髓移植) does not involve the transfer of a discrete anatomic organ as occurs in other forms of transplantation, but it entails the same risk of rejection by the recipient which is called graft-versus-hosts disease ( GVHD). The main indication for bone marrow transplantation are leukemia aplastic anemia, and congenital and diseases related to immunologic defects. Hormones 10 Hormones therapy is now recommended and used for disorders and diseases related to the deficiency of a particular hormone. For example, insulin preparations (胰岛素制剂) the deficiency of a treating type 1diabetes ( 1 型糖尿病) . DRUG THERAPY General Features 11 Study of the factors that influence the movement of drugs throughout the body is called pharmacokinetics, which includes the absorption, distribution, localization in tissues, biotransformation, and excretion of drugs. The study of the actions of the drugs and their effects is called pharmacodynamics.