Ad Blocker Detected
Our website is made possible by displaying online advertisements to our visitors. Please consider supporting us by disabling your ad blocker.
Select the ONE answer that is BEST in each case.
Which of the following is the most appropriate management for phenylketonuria?
In phenylketonuria, a low phenylalanine diet with relentless attention to details of diet is required for a good outcome. The diet should be started by 3 weeks of age. Children of mothers with phenylketonuria can be affected if exposed to phenylalanine in utero. Therefore, women with the disorder should stay on a restricted diet until they complete childbearing. In phenylalanine hydroxylase deficiency, tyrosine becomes an essential amino acid and dietary supplements must be provided.
A 21-year-old woman on no medications develops rigidity, tremor, and incoordination. She has a history of unexplained hepatitis 2 years ago and depression 1 year ago. Her examination is pertinent for increased tone, normal muscle strength, and coarse tremor of the hands. An ophthalmologic examination is positive for a brownish pigmented ring at the corneal margin. Which of the following findings is most likely to be present in this patient?
Wilson’s disease includes cirrhosis of the liver, signs of basal ganglia disease, and a brownish pigmented ring at the corneal margin (Kayser-Fleischer ring). Ceruloplasmin levels are low. The gene for Wilson’s disease is located on the long arm of chromosome 13. In some cases, it is possible to identify carrier states and make prenatal diagnoses. The relationship between the abnormal gene and the metabolic defect (inability to regulate copper balance) is unclear.
A 57-year-old man complains of increased thirst and urination. His examination is normal except for obesity (BMI>30). Which of the following is the most appropriate initial diagnostic test?
The gold standard is still a fasting plasma glucose = 7 mmol/L (126 mg/dL) on two separate occasions. GTTs are rarely required. With typical symptoms even an elevated random sugar is diagnostic.
Which of the following is the most likely effect of insulin at the cellular receptor level?
Other stimulators of protein kinases include platelet-derived growth factor and epidermal growth factor. Tyrosine phosphorylation results from this interaction. Insulin-resistant states can be caused by prereceptor resistance (mutated insulin, anti-insulin antibodies) or receptor and postreceptor resistance.
Which of the following is the most likely metabolic effect of insulin on adipose tissue?
The action of insulin involves all three major metabolic fuels (carbohydrate, protein, fat). It is active in liver, muscle, and adipose tissue. In each there are anticatabolic as well as anabolic effects. These tend to reinforce each other.
A 32-year-old woman presents with heat intolerance, palpitations, diarrhea, weakness, and weight loss. Her blood pressure is 90/60 mm Hg, pulse 110/min, and she has a fine tremor in her hands. The TSH level is suppressed and T3 and T4 are elevated. Which of the following is most likely to precipitate this condition?
Infection or other acute medical condition is the usual precipitant for thyroid storm. Radioactive iodine treatment or abrupt withdrawal of antithyroid medications is also implicated. The key diagnostic features are fever, tachycardia, and central nervous system dysfunction.
A 15-year-old youth has not gone through puberty. Which of the following is the most likely diagnosis?
All the causes listed may delay puberty, but the most common cause by far is normal variation in growth pattern. There is often a family history of delayed puberty in parents or siblings. In these individuals, bone age oftencorrelates better with the onset and progression of puberty than does chronologic age.
A 44-year-old woman is recently diagnosed with breast cancer and undergoes a mastectomy. Which of the following features is most likely to be important in determining response to tamoxifen therapy?
Approximately, one-third of unselected women with metastatic breast cancer will respond to tamoxifen. Presence of estrogen receptors (ER) or PR improves the likelihood of response. If the tumor is both ER and PR positive, the response rate is 70%.
Which of the following increases a woman’s risk of breast cancer?
A generally increased risk of breast cancer is associated with nulliparity, late first pregnancy, and, especially, a history of maternal breast cancer. Prior history of breast cancer is of course a powerful risk factor.
Which of the following statements is correct?
Although the variation is great depending on occupation, hobbies, and so forth, generally only one-third of energy is utilized for physical activity. Height is not used at all in calculating RMR, and RMR is higher in men than in women of identical weight. Amino acids ingested without other energy sources are inefficiently incorporated into protein. Current recommendations are to encourage full adult levels of protein, vitamins, and minerals in the elderly.
A 35-year-old woman, on hemodialysis for chronic renal disease, complains of pain in the hands. On examination, the joints are normal with no inflammation or tenderness on palpation. Lab values reveal a low calcium, high phosphate, and high PTH level. What is the most likely diagnosis?
The diagnosis is secondary hyperparathyroidism as a consequence of the chronic renal disease. Calcium deposits are seen in the periarticular areas of the fourth and fifth metacarpophalangeal, third proximal interphalangeal, and fourth distal interphalangeal joints. There is slight soft tissue swelling, especially, of the fourth and fifth metacarpophalangeal joints. Calcification in scleroderma is subcutaneous in location. In gout, if monosodium urate is deposited it could appear as a soft tissue mass.
A 35-year-old woman presents with fatigue, weakness, and weight gain. Her blood pressure is 155/90 mm Hg, pulse 80/min, and there is central obesity with skin striae. Investigations are shown in Table. Which of the following is the most likely diagnosis?
Autonomous adrenal tumors are adrenocorticotropic hormone (ACTH) insensitive and fail to demonstrate a brisk rise in urinary 17-hydroxycorticoids. Androgenic effects, such as hirsutism, are usually absent. In Cushing’s syndrome, secondary to an autonomous adrenal tumor, onset is usually gradual, and hirsutism, other androgenic effects, and hyperpigmentation are absent.
A 55-year-old obese woman complains of vulvar pruritus, recent weight loss in spite of a large appetite, and waking up frequently at night to urinate. Which of the following is the most likely diagnosis?
DM is a syndrome consisting of hyperglycemia, large vessel disease, microvascular disease, and neuropathy. The classic presenting symptoms are increased thirst, polyuria, polyphagia, and weight loss. In Type II diabetes, the presentation can be more subtle and is often made when the patient is asymptomatic.
A 72-year-old man with Type II diabetes notices painless skin lesions on his legs. They have an irregular raised border with a flat depressed center that is hyperpigmented brown in color.
Pyoderma gangrenosum is not a cutaneous manifestation of diabetes. Perineal pruritus in a diabetic is almost always associated with Candida albicans. A severe external otitis can occur in older patients. It is caused by Pseudomonas aeruginosa and is characterized by ear pain, drainage, fever, and leukocytosis. Facial nerve paralysis can occur and is a poor prognostic sign. Necrobiosis lipoidica is a plaque-like lesion with a brown border and yellow center usually found on the anterior leg surface.
Can be caused by high prolactin level
High prolactin level suppresses luteinizing hormone-releasing hormone (LH-RH), and can result in low plasma gonadotropin and testosterone levels. It may not be obvious on physical examination. Therapy with a dopamine agonist may lower prolactin levels and reverse impotence.
Rarely indicates organic disease
An absent orgasm, when libido and erectile function are normal, invariably indicates that organic disease is absent. Loss of desire canalso be caused by psychologic disturbance, but may indicate androgen deficiency or drug effect.
Can be caused by hematologic disease
Failure of detumescence—priapism—can be caused by sickle cell anemia or chronic granulocytic leukemia. Priapism must be treated promptly to preserve future erectile functioning.
Can be caused by vascular disease
Vascular disease, by itself or in conjunction with peripheral neuropathy in DM, is a common cause of erectile dysfunction. The lesions can be in large vessels (aortic occlusion, Leriche syndrome), small arteries, or even in the sinusoidal spaces.
Slight elevation of plasma testosterone and androstenedione
Idiopathic hirsutism may simply represent an extreme of normal androgen production. It is diagnosed by demonstrating minimal elevation of androgens and exclusion of other causes. Management is primarily by cosmetic therapy, although drugs to suppress androgen production and/or androgen effects on the hair follicle can be used.
Can be associated with anovulation, obesity, and amenorrhea
The most severe form of PCOD, SteinLeventhal syndrome, is associated with chronic anovulation, hirsutism, enlarged cystic ovaries, obesity, and amenorrhea. The spectrum of disease, however, is quite wide, and some patients have only mild hirsutism.