Lectus

A 62-year-old man presents to the emergency department with fatigue and shortness of breath on exertion. He says that his symptoms began gradually five days ago and have worsened progressively. His medical history is significant for chronic alcoholism. His vital signs are: Blood pressure 100/60 mm Hg, temperature 36.9°C (98.4°F), respiratory rate 18/min, and pulse rate 98/min. Physical examination reveals bilateral pedal edema and decreased sensation in both feet. Bibasilar crackles and rhonchi are heard bilaterally on pulmonary auscultation. Cardiac examination is unremarkable. A chest X-ray shows cardiomegaly. What vitamin deficiency is most likely responsible for this patient’s condition?Deselect Answer

A 50-year-old woman presents with acute onset fever and chills for the past hour. She mentions that she felt blue earlier in the day, so she took some St. John’s wort because a friend told her that it helps with depression. Past medical history is significant for hypertension, diabetes mellitus, and depression managed medically with captopril, metformin, and fluoxetine, respectively. She has no history of allergies. Her pulse is 130/min, respirations are 18/min, blood pressure is 176/92 mm Hg, and temperature is 38.5°C (101.3°F). On physical examination, the patient is profusely diaphoretic and extremely irritable when asked questions but oriented x3. The abdomen is soft and nontender with no hepatosplenomegaly. Increased bowel sounds are heard in the abdomen. Deep tendon reflexes are 3+ bilaterally and clonus is elicited. Sensation is decreased in the feet bilaterally. Mydriasis is present. Fingerstick glucose is 140 mg/dL. An ECG shows sinus tachycardia but is otherwise normal. Which of the following is the most likely cause of this patient’s condition?Deselect Answer

A 45-year-old man presents with rectal bleeding and fatigue for the past 3 months. His father was diagnosed with colorectal cancer at age 48, and his paternal uncle had multiple colon polyps removed at age 52. Colonoscopy reveals approximately 40 adenomatous polyps throughout the colon. Genetic testing is performed, which identifies biallelic mutations in a gene involved in DNA repair. Histologic examination of a biopsy specimen from one of the polyps shows an increase in G:C to T:A transversions. Which of the following best describes the underlying genetic defect in this patient?Deselect Answer

A 72-year-old man presents with a 3-month history of increasing constipation and difficulty with defecation. He reports straining during bowel movements and a sensation of incomplete evacuation. Physical examination reveals decreased rectal tone. During digital rectal examination, the physician notes that the patient cannot voluntarily contract his external anal sphincter when asked. A defecography study shows inadequate relaxation of the puborectalis muscle during attempted defecation. Which of the following best describes the physiological mechanism involved in normal defecation?Deselect Answer