Nokea
Women who have breast cancer due to a BRCA1 gene mutation are usually:
- A. positive for human epidermal growth factor receptor 1 and 2.
- B. negative for estrogen receptor.
- C. positive for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
- D. negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
Correct Answer: D
Rationale: Women with breast cancer due to a BRCA1 gene mutation commonly have a triple-negative breast cancer subtype, which means they are negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). This subtype tends to be more aggressive and harder to treat. Choice A is incorrect as they are typically negative for HER2. Choice B is incorrect because they are usually negative for estrogen receptor. Choice C is incorrect as they are usually negative for progesterone receptor and HER2.
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A man with gout has developed large, hard nodules around his toes and elbows. The phase of gout he is in is:
- A. asymptomatic
- B. acute flare
- C. the intercritical period
- D. chronic gout
Correct Answer: D
Rationale: The correct answer is 'chronic gout.' Chronic gout is characterized by the presence of tophi, which are large, hard nodules that can develop around joints like toes and elbows. These tophi are a sign of longstanding, untreated gout. Choice A, 'asymptomatic,' is incorrect as the presence of tophi indicates a symptomatic phase. Choice B, 'acute flare,' is incorrect as acute flares are characterized by sudden and severe pain, inflammation, and redness in the joints, not the development of tophi. Choice C, 'the intercritical period,' is also incorrect as this phase occurs between acute attacks and is typically asymptomatic, without the presence of tophi.
In nephritic syndrome compared to nephrotic syndrome, there is:
- A. higher amounts of albuminuria.
- B. negligible hematuria or absence of hematuria.
- C. presence of red blood cell casts in the urine.
- D. hypoalbuminemia
Correct Answer: C
Rationale: In nephritic syndrome, the presence of red blood cell casts in the urine is a characteristic finding, reflecting glomerular inflammation and damage. This differentiates it from nephrotic syndrome, where red blood cell casts are typically absent. Choice A is incorrect because nephritic syndrome usually presents with less albuminuria compared to nephrotic syndrome. Choice B is incorrect as hematuria is a common feature of nephritic syndrome. Choice D is incorrect as hypoalbuminemia is more commonly associated with nephrotic syndrome.
A 30-year-old has poorly controlled asthma and is taking prednisone 10 mg by mouth once a day. He has been on this regimen for 6 weeks. Abrupt withdrawal or discontinuation of this medication can cause:
- A. adrenal crisis
- B. hypercortisolism
- C. ACTH stimulation
- D. thyroid crisis
Correct Answer: A
Rationale: Abrupt withdrawal or discontinuation of prednisone, a corticosteroid, can lead to adrenal crisis. This occurs due to the suppression of the adrenal glands' natural cortisol production caused by prolonged exogenous steroid administration. Adrenal crisis presents with symptoms such as weakness, fatigue, abdominal pain, and hypotension. Hypercortisolism (Cushing syndrome) results from chronic excessive exposure to cortisol, not abrupt withdrawal. ACTH stimulation would be expected in response to low cortisol levels, not as a direct consequence of prednisone withdrawal. Thyroid crisis (thyroid storm) is associated with severe hyperthyroidism and is not directly related to corticosteroid withdrawal.
Why does multiple sclerosis manifest as asymmetrical and in different parts of the body?
- A. Autoreactive lymphocytes are causing diffuse patchy damage to the myelin sheath in the central nervous system.
- B. Acetylcholine receptors are destroyed by immunoglobulin G.
- C. Autoreactive T lymphocytes cause progressive loss of neurons in the substantia nigra.
- D. Cortical motor cells degenerate.
Correct Answer: C
Rationale: Multiple sclerosis is characterized by the immune system mistakenly attacking the myelin sheath in the central nervous system. This results in the formation of lesions that can occur in different parts of the central nervous system, leading to varied symptoms depending on the location of the damage. Choice A is the correct answer because it accurately describes the pathophysiology of multiple sclerosis. Choices B, C, and D are incorrect because they describe mechanisms or locations that are not associated with the pathogenesis of multiple sclerosis.
What is the pathophysiologic process responsible for the decreased glomerular filtration rate in a patient with acute glomerulonephritis?
- A. Decreased renal-induced constriction of the renal arteries
- B. Immune complex deposition, increased capillary permeability, and cellular proliferation
- C. Necrosis of 70% or more of the nephrons secondary to increased kidney interstitial hydrostatic pressure
- D. Scar tissue formation throughout the proximal convoluted tubule secondary to toxin-induced collagen synthesis
Correct Answer: B
Rationale: The correct answer is B: Immune complex deposition, increased capillary permeability, and cellular proliferation. Acute glomerulonephritis is characterized by inflammation of the glomeruli in the kidneys. This inflammation leads to the deposition of immune complexes, increased capillary permeability, and cellular proliferation, which collectively contribute to a decreased glomerular filtration rate. Choice A is incorrect as decreased renal-induced constriction of the renal arteries would not directly result in decreased glomerular filtration rate. Choice C is incorrect as necrosis of nephrons due to increased kidney interstitial hydrostatic pressure would affect kidney function differently. Choice D is incorrect as scar tissue formation in the proximal convoluted tubule due to toxin-induced collagen synthesis is not a typical feature of acute glomerulonephritis.