Lipid metabolism — MCQs

An 11-year-old male is brought in by ambulance to the emergency department after being a restrained passenger in a motor vehicle accident. His father was driving him to soccer practice when they were hit by a wrong way driver. On presentation, his temperature is 101°F (38.3°C), blood pressure is 100/62 mmHg, pulse is 108/min, and respirations are 21/min. He is found to be agitated and complains of nausea, severe epigastric pain, and lower extremity pain. Physical exam reveals lacerations and ecchymosis on his left forehead, right flank, and lower extremities. Radiographs demonstrate an open book fracture of the pelvis as well as bilateral femur fractures. Despite multiple interventions, his condition deteriorates and he passes away from his injuries. Post-mortem pathologic examination of abdominal tissues reveals white deposits containing calcium. Abnormal activity of which of the following proteins is most likely responsible for these deposits?

A 67-year-old gentleman with severe COPD is found to have a respiratory quotient of 0.8. His physician would like to decrease the amount of CO2 produced by the patient's metabolism, thereby reducing the energy breathing expenditure required to eliminate the patient's CO2 respiratory burden. Which of the following dietary modifications would decrease this patient's respiratory quotient?

A 35-year-old pregnant woman gives birth to a baby at term. The antepartum course was uneventful. She was compliant with all prenatal examinations and was given a prophylactic tetanus vaccine. While performing the neonatal examination, the pediatrician reports Apgar scores of 9 and 10 at 1 and 5 min, respectively. The pediatrician notices that the baby has ambiguous genitalia and blood pressure that is high for a neonate. The notable laboratory results are as follows: Renin 0.4 nmoL/L/h Aldosterone 70 pmoL/L Cortisol 190 nmoL/L Serum creatinine 1.0 mg/dL Sex hormones are higher than the normal values at this age. Which of the following is responsible for the neonate's hypertension?

A 4-month-old boy is brought to the emergency department by his mother because of lethargy and vomiting since he woke up 1 hour ago. The mother says that he last breastfed the previous evening and slept through the night for the first time. His family recently immigrated from Bolivia. His temperature is 38.7°C (101.2°F). Physical examination shows dry mucous membranes and enlarged, reddened tonsils. Serum studies show: Glucose 42 mg/dL Ketones 0.2 mg/dL N = < 1 mg/dL AST 40 U/L ALT 60 U/L Ammonia 80 μ/dL (N=15–45) Which of the following enzymes is most likely deficient in this patient?

A 24-year-old man presents for an annual check-up. He is a bodybuilder and tells you he is on a protein-rich diet that only allows for minimal carbohydrate intake. His friend suggests he try exogenous glucagon to help him lose some excess weight before an upcoming competition. Which of the following effects of glucagon is he attempting to exploit?

At postpartum physical examination, a newborn is found to have male external genitalia. Scrotal examination shows a single palpable testicle in the right hemiscrotum. Ultrasound of the abdomen and pelvis shows an undescended left testis, seminal vesicles, uterus, and fallopian tubes. Chromosomal analysis shows a 46, XY karyotype. Which of the following sets of changes is most likely to be found in this newborn? Legend: Normal = normal levels, ↑ = increased levels, ↓ = decreased levels SRY-gene activity | Müllerian inhibitory factor (MIF) | Testosterone | Dihydrotestosterone (DHT)

A 24-year-old woman presents to the emergency department with abdominal pain that started while she was at the gym. The patient competes as a power lifter and states that her pain started after one of her heavier lifts. The patient has no significant past medical history and is currently taking a multivitamin and oral contraceptive pills. She smokes cigarettes and drinks alcohol regularly and is currently sexually active with multiple partners. Her temperature is 99°F (37.2°C), blood pressure is 85/55 mmHg, pulse is 125/min, respirations are 18/min, and oxygen saturation is 99% on room air. Physical exam is notable for right upper quadrant abdominal tenderness, acne, and muscle hypertrophy. Right upper quadrant ultrasound demonstrates a solitary heterogeneous mass. Which of the following other findings is most likely to be found in this patient?

A 4-year-old boy is brought to the physician because of frequent falls, worsening muscle pain, and poor vision in low light conditions. His mother reports that he has been on a low-fat diet since infancy because of persistent diarrhea. He is at the 5th percentile for height and weight. Physical examination shows bilateral proximal muscle weakness and a wide ataxic gait. His serum cholesterol level is 21 mg/dL. Peripheral blood smear shows red blood cells with irregular spiny projections of varying size. Further evaluation of this patient is most likely to show which of the following findings?

A 70-year-old chronic smoker presents to the emergency department with a sudden onset of left-sided weakness. The past medical history is insignificant except for hypertension, for which he has been taking medications regularly. The vital signs include: blood pressure 165/110 mm Hg, pulse rate 78/min, respiratory rate 18/min, and temperature 36.1°C (97°F). The neurologic examination shows ⅗ muscle strength in the left upper and lower limbs. An occlusion of a branch of the right middle cerebral artery is suspected because the CT fails to show signs of hemorrhage. The HbA1C is 11%. Which of the following blood lipid components is the most important contributing factor leading to his condition?

A 16-year-old girl with celiac disease is brought to the physician because of a 1-week history of generalized weakness and tingling around her mouth and in her fingertips. She also complains of abdominal cramps and nausea. In addition to following a gluten-free diet, she has been following a vegan diet for the past 2 years. Physical examination shows involuntary contractions of the muscle at the corner of her mouth and nose that are elicited by tapping on her right cheek. Her parathyroid hormone concentration is 834 pg/mL. Which of the following is the most likely underlying cause for this patient's current condition?