Correct Answer: B

Section: Microbiology/Immunology Interleukin-1 (IL-1) is a protein generated primarily by macrophages. The cytokine is called endogenous pyrogen because it acts on the hypothalamus to produce fever during infections and inflammatory conditions. Thus individuals who are unable to produce IL-1 most likely will have to depend on endotoxin, the exogenous pyrogen, to induce febrile reactions. Mediation of immunoglobulin isotypic switching (choice A) requires IL-4 and IL-5. Acute-phase responses (choice C) and shock (choice D) are mediated by IL-6 and TNFalpha, TNF-alpha. Intense inflammatory reactions are produced by IL-1 (choice E).

Correct Answer: B

Section: Pathology and Path physiology Goodpasture syndrome consists of antibodies against basement membrane material, recurrent pulmonary hemorrhage, and glomerulonephritis. The pathologic changes are due to a type II hypersensitivity reaction along the basement membranes of the lung and kidney. Steroids, plasmapheresis, and immunosuppressive medicines may help in a minority of cases. Fibrosing alveolitis (choice A) is a pulmonary disorder of unknown etiology. Glomerulonephritis and pulmonary hemorrhage are not observed clinically. Kartagener syndrome (choice C) is a hereditary disease of infancy due to a defect in respiratory ciliary action. Systemic lupus erythematosus (choice D) may present with renal insufficiency. Antibodies are directed against nuclear antigens. Wegener granulomatosis (choice E) may present clinically with pulmonary hemorrhages and renal insufficiency. There are antibodies against neutrophil components, not basement membrane material.

Correct Answer: B

Correct Answer: A

Section: Pharmacology Diplopia, abnormal gait, and other signs of cerebellar dysfunction are important symptoms of phenytoin toxicity. Other manifestations of toxicity include gingival hyperplasia, nystagmus, and vertigo. Hyperprolactinemia (choice B) is an adverse effect of antipsychotic dopamine antagonists such as the phenothiazines; dopamine inhibits prolactin secretion by the anterior pituitary. Polydipsia and polyuria (choice C) are symptoms of diabetes insipidus. These symptoms may be produced by lithium toxicity during treatment of bipolar depression, and are not associated with phenytoin toxicity. Postural hypotension (choice D) is not an adverse effect of phenytoin but often occurs with levodopa treatment of Parkinson's disease. Rigidity and tremor (choice E) are symptoms of parkinsonism. These symptoms may be produced by dopamine antagonists such as antipsychotic agents, but are not associated with phenytoin toxicity.

Correct Answer: A

Section: Behavioral Science and Biostatics The infant mortality rate in the United States is 8.9 deaths per 1000 live births as of 1989, which ranks the United States behind 11 other developed countries. The leading causes of infant death are congenital anomalies, respiratory distress syndrome, and sudden infant death syndrome; therefore, choice C is incorrect. Choices B, D, and E are incorrect because prenatal care does reduce infant mortality, but only 80% of Caucasian women receive prenatal care, followed by 75% of Asian American women, 65% of African American women, and 60% of Native American women. The infant mortality rate for black infants is greater than that of white infants.