USMLE USMLE-STEP-2 Exam Dumps

Correct Answer: C

Premature thelarche is a benign, self-limited disorder that does not progress. Breast development may actually regress, though the regression may not be complete. The girl and her parents should be assured that the events of puberty will be normal at a normal age. Examination of the girl should be repeated at 3to 6-month intervals for about 1 year to be certain that additional pubertal events do not occur (such as growth of pubic hair, accelerated linear growth, and vaginal bleeding). Because pituitary and adrenal functions are normal for a prepubertal girl, therapy with a GnRH agonist (Lupron, Synarel, and so forth) or a corticosteroid is ineffective and inappropriate. Although breast cancer is a rare possibility in prepubertal girls, the presence of bilateral breast buds effectively excludes this diagnosis. A breast biopsy may destroy breast analge, and these girls will not have breast development at puberty.

Correct Answer: B

Heparin is the drug of choice for anticoagulation in pregnancy. Little of it crosses the placenta, and it is not associated with congenital birth defects. Experience with low molecular weight heparin in pregnancy is increasing and appears to be safe for mother and fetus. In full therapeutic doses, low molecular weight heparin offers the advantage of less or no monitoring of its anticoagulant effect. Coumadin readily crosses the placenta and is associated with birth defects in 1525% of fetuses exposed throughout the first trimester. Aspirin is ineffective as an anticoagulant, although the risk of maternal or fetal bleeding (e.g., placental abruption, fetal intracranial bleeding) is increased. There is no clinical experience with TPA in pregnancy. Because pregnancy itself is a thrombogenic condition, anticoagulation throughout pregnancy is indicated. Vena caval filters offer no advantage over heparin and require an invasive procedure.

Correct Answer: B

Sometimes it is possible to identify subgroups or strata of a population. Randomly sampling these segments, called strata, may reduce sampling error. Systematic sampling, selecting every "ith" individual, is not necessarily random, depending on how lists are constructed. Random groups would presumably be based on random selection of individuals, and little benefit would derive from studying such groups. Random groups produce more hazards statistically than randomized strata. Clusters are somewhat different; they may be small groups of the population occurring in specific areas, such as families, villages, or wards. The characteristics of clusters are not necessarily those of the population, but more those of location. Cluster sampling may be useful but does not have the same outcome as a stratified sample.