Medical Tactics

A 24-year-old woman in her third trimester of pregnancy presents with urinary frequency and burning for the past few days. She denies fever, nausea, vomiting, or chills. She takes no medications besides prenatal vitamins and is generally in good health. Physical examination is remarkable for mild suprapubic tenderness, and a urine dipstick is positive for white blood cells, protein, and a small amount of blood. Culture produces greater than 100,000 colonies of gram-negative bacilli. which of the following attributes of this uropathogenic organism is most strongly associated with its virulence?

A 20-year-old develops weakness accompanied by difficulty in relaxation that is most pronounced in the hands and feet. Muscle biopsy demonstrates prominent ring fibers, centrally located nuclei, chains of nuclei, and disorganized sarcoplasmic masses. This condition been associated with a mutation on which of the following chromosomes?

Which of the following hormones is secreted by anterior pituitary cells that stain with acidic dyes?

A 36-year-old Asian male complains of difficulty swallowing. Esophagoscopy reveals a polypoid mass that is subsequently biopsied.  In addition to tumor cells, the esophageal biopsy show normal smooth  muscle and striated muscle in the same section. Which portion of the  esophagus was the source of this biopsy?

Which of the following respiratory system components is derived

The heart of an embryo first begins beating at which of the following ages?

A neuroscientist is investigating the development of the nervous system. In his experiments, he microinjects a dye into the embryo of  an animal subject in vivo. After birth, he performs histological  studies to determine the destination of the dye. In one animal subject,  he locates the dye in the dorsal horn of the spinal cord. Which of the  following locations in the embryo was the most likely site of the injection?

A patient with prolonged diarrhea undergoes esophagogastroduodenoscopy.  Biopsy of the small intestine demonstrates numerous crescent-shaped  protozoa adjacent to the epithelial brush border. Which of the following  organisms is the most likely pathogen?

A 25-year-old woman with sickle cell anemia complains of steady pain in her right upper quadrant with radiation to the right shoulder, especially after large or fatty meals. Her physician diagnoses gallstones. Of which of the following compounds are these stones most likely composed?

IV administration of drug X to an anesthetized animal produces an increase in blood pressure. After administration of drug Y,  readministration of drug X produces a decrease in blood pressure.  Which of the following pairs of drugs could produce this sequence of events?