06-13-2006, 05:40 AM
. During the conversion of proinsulin to insulin, bonds between which of the following amino acid residues keep the two chains of the insulin molecule together?
A. Cysteine
B. Lysine
C. Methionine
D. Serine
E. Tyrosine
4. Cultured cells are treated with an experimental agent that leads to rapid increases in cytoplasmic calcium concentrations and an increase in cellular diacylglycerol concentrations. This experimental agent most likely stimulates which of the following?
A. Adenylyl cyclase
B. GTPase-activating protein
C. Phospholipase C
D. Protein kinase A
E. Protein kinase C
6. Southern blotting is used to distinguish maternal and paternal copies of chromosome 7 in a single person. The diagram on the top indicates the DNA region that is amplified and the predicted sites of digestion with restriction endonucleases. The site of hybridization of the labeled probe is also indicated. The gel pattern obtained is shown on the bottom. This pattern is most likely indicative of which of the following?
A. Chromosome walking
B. Meiotic segregation
C. Nondisjunction of chromosomes during meiosis
D. Recombination
E. Restriction fragment length polymorphism
7. A neoplasm in the colon invades through the basement membrane into the lamina propria. Which of the following proteins is most likely to be directly involved in the process of invasion?
A. APC gene product
B. p53 protein
C. ras gene product
D. Rb gene product
E. Type IV collagenase 17. In a cohort study, 10,000 men who consume alcohol were compared with 10,000 men who do not consume alcohol. The results show that men who consume alcohol have an increased risk for cancer of the bladder that is statistically significant at the 5% level. Which of the following is the most appropriate interpretation of this result?
A. At least 5% of the bladder cancers can be attributed to consumption of alcohol
B. At least 5% of consumers of alcohol will develop cancer of the bladder
C. Such an effect would occur by chance in less than 5% of repeated samples of this size
D. There is at least a 5% increased risk for bladder cancer among consumers of alcohol
E. Men who drink alcohol are 5 times more likely to develop bladder cancer than those who do not drink alcohol
18. A 2-year-old boy with normal size, weight, and development is brought to the physician because of a painful, swollen left knee for the past week. He has had two episodes of asymptomatic hematuria during the past 6 months. Both parents are healthy. He has achieved developmental milestones at appropriate ages. His height and weight are at the 70th percentile. Examination shows bruises and resolving hematomas on both elbows and signs of cutaneous hemorrhages at the site of a deep splinter. Laboratory studies show:
Hemoglobin 12 g/dL
Erythrocyte count normal
Leukocyte count normal
Bleeding time normal
Partial thromboplastin time increased
The most likely diagnosis can be proven by the therapeutic response to a single injection of which of the following materials?
A. Factor I (fibrinogen)
B. Factor VIII (antihemophilic factor)
C. Factor IX (plasma thromboplastin component)
D. Folic acid
E. Vitamin K
22. During an experimental study of the mechanisms of nerve conduction, a researcher isolates a nerve and uses a microelectrode to measure its membrane potential distal to a site of electrical stimulation. The resting potential of the nerve is found to be ˆ'90 mV. The following membrane potentials are then recorded at various points in time after stimulation:
Time After Stimulation (msec) Membrane Potential
0 -90 mV
0.5 +25 mV
1 -100 mV
2 -90 mV
The change in membrane potential from the resting potential occurring between 0.5 and 1 milliseconds is most likely caused by increased permeability to which of the following ions?
A. Ca2+
B. Cl-
C. K+
D. Na+
24. A 10-year-old girl is brought to the physician because of several 1- to 3-cm, light brown macules on her trunk as shown in the photograph. Physical examination shows axillary freckling. Neurologic examination shows no focal findings. Which of the following is the most likely diagnosis?
A. Dysplastic nevus syndrome
B. Neurofibromatosis
C. Osler-Weber-Rendu disease
D. Tuberous sclerosis
E. von Hippel-Lindau disease
E. PO4-
32. An 80-year-old woman dies shortly after admission to the hospital because of a 3-day history of progressively increasing shortness of breath. She had a history of heart failure. Examination of the lungs during autopsy shows alveolar damage with distended lymphatics, congested alveolar capillaries, and pink-staining homogenous proteinaceous hyaline material in alveoli. Which of the following is the most likely cause of these findings?
A. Amyloidosis
B. Aspiration pneumonitis
C. Emphysema
D. Pneumonia
E. Pulmonary edema
F. Septic shock
38. A 42-year-old man who is a resident of the USA comes to the physician because of greasy foul-smelling stools and a 5.5-kg (12-lb) weight loss over the past 6 months. He has a 6-year history of chronic abdominal and back pain. The epigastrium is tender on deep palpation. A CT scan of the abdomen shows pancreatic atrophy and calcifications. Which of the following is the most likely cause of his disease?
A. Alcohol dependence
B. Congenital pancreatic cyst
C. Diabetes mellitus
D. Gallstones
E. Heredity
F. Pancreas divisum
G. Protein-calorie malnutrition
39. A 55-year-old man comes to the physician because of a 2-month history of intermittent, severe, sharp abdominal pain that occurs primarily after meals and lasts about 30 to 60 minutes. There is no fever, diarrhea, or weight loss. Physical examination shows no abnormalities. Which of the following is most likely responsible for these symptoms?
A. Acute cholecystitis
B. Ascending cholangitis
C. Biliary colic
D. Primary biliary cirrhosis
E. Sclerosing cholangitis
40. A 22-year-old woman is brought to the emergency department unconscious 30 minutes after sustaining multiple injuries in a motor vehicle collision. Her temperature is 36°C ( 96.8°F), pulse is 82/min, respirations are 6/min, and blood pressure is 110/75 mm Hg. Physical examination shows significant head trauma with a depressed segment of parietal bone. Arterial blood gas analysis on room air shows:
pH 7.17
PC O2 80 mm Hg
P O2 50 mm Hg
HCO3ˆ' 28 mEq/L
A. Which of the following renal compensatory responses will occur in this patient?
B. Decreased H+ secretion into the tubule
C. Decreased proximal tubule HCO3- reabsorption
D. Decreased titratable acid excretion
E. Increased HCO3- excretion
F. Increased NH4Cl excretion
45. A 32-year-old nulligravid woman comes to the physician because she has not been able to conceive for 2 years. She has a 3-year history of pelvic pain and dyspareunia. Pelvic examination shows enlargement of the left adnexa and nodularity of the cul-de-sac. Laparoscopy shows dark areas 3 to 5 mm in diameter throughout the cul-de-sac. The left adnexa are covered by adhesions and cannot be visualized. A biopsy specimen of the cul-de-sac lesion is most likely to show which of the following?
A. Adenocarcinoma
B. Endometrial glands and stroma
C. Epithelial inclusion cysts
D. Granuloma
E. Mesothelial tumor
49. A 51-year-old man comes to the physician because of fatigue, weakness, and joint pain for the past 5 days. For the past 9 months, he has been taking 10 mg of prednisone daily for severe rheumatoid arthritis. He tells the physician that he misplaced his medication last week and did not have it replaced. Which of the following mechanisms is most likely responsible for the development of these symptoms in this patient?
A. Adrenal atrophy due to suppression of ACTH secretion
B. Decreased conversion of cortisone to hydrocortisone
C. Downregulation of glucocorticoid receptors in target tissues
D. Increased clearance of endogenous adrenal steroids
E. Increased concentrations of plasma corticosteroid-binding globulin
50. A 75-year-old man is taking medications for hypertension, hypercholesterolemia, insomnia, and osteoarthritis. An age-related decline in which of the following pharmacokinetic processes is most likely to affect his treatment?
A. Gastric absorption
B. Hepatic glucuronidation
C. Hepatic oxidative metabolism
D. Protein binding in the serum
E. Renal tubular secretion
A. Cysteine
B. Lysine
C. Methionine
D. Serine
E. Tyrosine
4. Cultured cells are treated with an experimental agent that leads to rapid increases in cytoplasmic calcium concentrations and an increase in cellular diacylglycerol concentrations. This experimental agent most likely stimulates which of the following?
A. Adenylyl cyclase
B. GTPase-activating protein
C. Phospholipase C
D. Protein kinase A
E. Protein kinase C
6. Southern blotting is used to distinguish maternal and paternal copies of chromosome 7 in a single person. The diagram on the top indicates the DNA region that is amplified and the predicted sites of digestion with restriction endonucleases. The site of hybridization of the labeled probe is also indicated. The gel pattern obtained is shown on the bottom. This pattern is most likely indicative of which of the following?
A. Chromosome walking
B. Meiotic segregation
C. Nondisjunction of chromosomes during meiosis
D. Recombination
E. Restriction fragment length polymorphism
7. A neoplasm in the colon invades through the basement membrane into the lamina propria. Which of the following proteins is most likely to be directly involved in the process of invasion?
A. APC gene product
B. p53 protein
C. ras gene product
D. Rb gene product
E. Type IV collagenase 17. In a cohort study, 10,000 men who consume alcohol were compared with 10,000 men who do not consume alcohol. The results show that men who consume alcohol have an increased risk for cancer of the bladder that is statistically significant at the 5% level. Which of the following is the most appropriate interpretation of this result?
A. At least 5% of the bladder cancers can be attributed to consumption of alcohol
B. At least 5% of consumers of alcohol will develop cancer of the bladder
C. Such an effect would occur by chance in less than 5% of repeated samples of this size
D. There is at least a 5% increased risk for bladder cancer among consumers of alcohol
E. Men who drink alcohol are 5 times more likely to develop bladder cancer than those who do not drink alcohol
18. A 2-year-old boy with normal size, weight, and development is brought to the physician because of a painful, swollen left knee for the past week. He has had two episodes of asymptomatic hematuria during the past 6 months. Both parents are healthy. He has achieved developmental milestones at appropriate ages. His height and weight are at the 70th percentile. Examination shows bruises and resolving hematomas on both elbows and signs of cutaneous hemorrhages at the site of a deep splinter. Laboratory studies show:
Hemoglobin 12 g/dL
Erythrocyte count normal
Leukocyte count normal
Bleeding time normal
Partial thromboplastin time increased
The most likely diagnosis can be proven by the therapeutic response to a single injection of which of the following materials?
A. Factor I (fibrinogen)
B. Factor VIII (antihemophilic factor)
C. Factor IX (plasma thromboplastin component)
D. Folic acid
E. Vitamin K
22. During an experimental study of the mechanisms of nerve conduction, a researcher isolates a nerve and uses a microelectrode to measure its membrane potential distal to a site of electrical stimulation. The resting potential of the nerve is found to be ˆ'90 mV. The following membrane potentials are then recorded at various points in time after stimulation:
Time After Stimulation (msec) Membrane Potential
0 -90 mV
0.5 +25 mV
1 -100 mV
2 -90 mV
The change in membrane potential from the resting potential occurring between 0.5 and 1 milliseconds is most likely caused by increased permeability to which of the following ions?
A. Ca2+
B. Cl-
C. K+
D. Na+
24. A 10-year-old girl is brought to the physician because of several 1- to 3-cm, light brown macules on her trunk as shown in the photograph. Physical examination shows axillary freckling. Neurologic examination shows no focal findings. Which of the following is the most likely diagnosis?
A. Dysplastic nevus syndrome
B. Neurofibromatosis
C. Osler-Weber-Rendu disease
D. Tuberous sclerosis
E. von Hippel-Lindau disease
E. PO4-
32. An 80-year-old woman dies shortly after admission to the hospital because of a 3-day history of progressively increasing shortness of breath. She had a history of heart failure. Examination of the lungs during autopsy shows alveolar damage with distended lymphatics, congested alveolar capillaries, and pink-staining homogenous proteinaceous hyaline material in alveoli. Which of the following is the most likely cause of these findings?
A. Amyloidosis
B. Aspiration pneumonitis
C. Emphysema
D. Pneumonia
E. Pulmonary edema
F. Septic shock
38. A 42-year-old man who is a resident of the USA comes to the physician because of greasy foul-smelling stools and a 5.5-kg (12-lb) weight loss over the past 6 months. He has a 6-year history of chronic abdominal and back pain. The epigastrium is tender on deep palpation. A CT scan of the abdomen shows pancreatic atrophy and calcifications. Which of the following is the most likely cause of his disease?
A. Alcohol dependence
B. Congenital pancreatic cyst
C. Diabetes mellitus
D. Gallstones
E. Heredity
F. Pancreas divisum
G. Protein-calorie malnutrition
39. A 55-year-old man comes to the physician because of a 2-month history of intermittent, severe, sharp abdominal pain that occurs primarily after meals and lasts about 30 to 60 minutes. There is no fever, diarrhea, or weight loss. Physical examination shows no abnormalities. Which of the following is most likely responsible for these symptoms?
A. Acute cholecystitis
B. Ascending cholangitis
C. Biliary colic
D. Primary biliary cirrhosis
E. Sclerosing cholangitis
40. A 22-year-old woman is brought to the emergency department unconscious 30 minutes after sustaining multiple injuries in a motor vehicle collision. Her temperature is 36°C ( 96.8°F), pulse is 82/min, respirations are 6/min, and blood pressure is 110/75 mm Hg. Physical examination shows significant head trauma with a depressed segment of parietal bone. Arterial blood gas analysis on room air shows:
pH 7.17
PC O2 80 mm Hg
P O2 50 mm Hg
HCO3ˆ' 28 mEq/L
A. Which of the following renal compensatory responses will occur in this patient?
B. Decreased H+ secretion into the tubule
C. Decreased proximal tubule HCO3- reabsorption
D. Decreased titratable acid excretion
E. Increased HCO3- excretion
F. Increased NH4Cl excretion
45. A 32-year-old nulligravid woman comes to the physician because she has not been able to conceive for 2 years. She has a 3-year history of pelvic pain and dyspareunia. Pelvic examination shows enlargement of the left adnexa and nodularity of the cul-de-sac. Laparoscopy shows dark areas 3 to 5 mm in diameter throughout the cul-de-sac. The left adnexa are covered by adhesions and cannot be visualized. A biopsy specimen of the cul-de-sac lesion is most likely to show which of the following?
A. Adenocarcinoma
B. Endometrial glands and stroma
C. Epithelial inclusion cysts
D. Granuloma
E. Mesothelial tumor
49. A 51-year-old man comes to the physician because of fatigue, weakness, and joint pain for the past 5 days. For the past 9 months, he has been taking 10 mg of prednisone daily for severe rheumatoid arthritis. He tells the physician that he misplaced his medication last week and did not have it replaced. Which of the following mechanisms is most likely responsible for the development of these symptoms in this patient?
A. Adrenal atrophy due to suppression of ACTH secretion
B. Decreased conversion of cortisone to hydrocortisone
C. Downregulation of glucocorticoid receptors in target tissues
D. Increased clearance of endogenous adrenal steroids
E. Increased concentrations of plasma corticosteroid-binding globulin
50. A 75-year-old man is taking medications for hypertension, hypercholesterolemia, insomnia, and osteoarthritis. An age-related decline in which of the following pharmacokinetic processes is most likely to affect his treatment?
A. Gastric absorption
B. Hepatic glucuronidation
C. Hepatic oxidative metabolism
D. Protein binding in the serum
E. Renal tubular secretion