What is the primary cause of primary hypercholesteremia?
- A. High-density lipoprotein (HDL) defects
- B. Monogenic mutations, sedentary lifestyle, and high cholesterol diet
- C. Polygenic mutations and environmental factors
- D. Low-density lipoprotein (LDL) receptor mutation with defects in breakdown
Correct Answer: D
Rationale: The correct answer is 'Low-density lipoprotein (LDL) receptor mutation with defects in breakdown.' Primary hypercholesteremia is mainly caused by mutations in the LDL receptor, leading to impaired clearance of LDL cholesterol from the blood. This results in high levels of LDL cholesterol in the bloodstream. Choices A, B, and C are incorrect because they do not directly relate to the primary cause of primary hypercholesteremia.
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Which of the following chronic inflammatory skin diseases is characterized by angiogenesis, immune cell activation (particularly T cells), and keratinocyte proliferation?
- A. Psoriasis
- B. Melanoma
- C. Atopic dermatitis
- D. Urticaria
Correct Answer: A
Rationale: Psoriasis is the correct answer because it is a chronic inflammatory skin condition characterized by features such as angiogenesis (formation of new blood vessels), immune cell activation (especially T cells), and excessive keratinocyte proliferation. This results in the typical symptoms seen in psoriasis, such as red, scaly patches on the skin. Melanoma is a type of skin cancer arising from melanocytes, not characterized by the features mentioned. Atopic dermatitis is a different skin condition involving eczematous changes, not specifically associated with the described characteristics of psoriasis. Urticaria is a skin condition characterized by hives and does not involve the same pathophysiological processes as psoriasis.
The early stages of atheroma development are characterized by:
- A. macrophages full of oxidized low-density lipoprotein (LDL; i.e., foam cells) in the intima
- B. accumulation of lipids in the intima (i.e., fatty streak)
- C. accumulation of proteins such as collagen and elastin (i.e., fibrous cap)
- D. development of calcium and a necrotic lipid core
Correct Answer: A
Rationale: The correct answer is A. In the early stages of atheroma development, macrophages accumulate oxidized low-density lipoprotein (LDL) and transform into foam cells, leading to the formation of fatty streaks in the intima of blood vessels. This process is a hallmark of the initial stages of atherosclerosis. Choice B is incorrect as it describes the accumulation of lipids in the intima, which is a later event following foam cell formation. Choice C is also incorrect as it refers to the accumulation of proteins forming the fibrous cap, which occurs at a later stage to stabilize the atheroma. Choice D is incorrect as it describes the development of calcium and a necrotic lipid core, typically seen in advanced atherosclerosis rather than the early stages.
Which of the following disorders is more likely associated with blood in stool?
- A. Gastroesophageal reflux
- B. Crohn's disease
- C. Irritable bowel syndrome
- D. Colon cancer
Correct Answer: D
Rationale: Colon cancer is more likely associated with blood in stool due to the presence of bleeding from the tumor in the colon. Gastroesophageal reflux (Choice A) typically presents with heartburn and regurgitation but not blood in stool. Crohn's disease (Choice B) can cause gastrointestinal symptoms, but bloody stools are more commonly associated with ulcerative colitis. Irritable bowel syndrome (Choice C) is characterized by abdominal pain, bloating, and changes in bowel habits, but it does not typically cause blood in stool. Therefore, the correct answer is D, Colon cancer.
A hemoglobin electrophoresis is done to evaluate for sickle cell disease. The report reveals the person has HbAS, which means the person:
- A. is normal with no sickle cell disease.
- B. is a sickle cell carrier.
- C. has sickle cell anemia.
- D. has thalassemia.
Correct Answer: B
Rationale: The correct answer is that the person is a sickle cell carrier. In HbAS, 'Hb' stands for hemoglobin, 'A' indicates normal hemoglobin, and 'S' indicates the sickle cell trait. Individuals with HbAS are carriers of the sickle cell trait but do not have sickle cell disease. Choice A is incorrect because having the sickle cell trait means carrying the gene for sickle cell disease. Choice C is incorrect as sickle cell anemia is a different condition where individuals have two copies of the abnormal hemoglobin gene, resulting in the disease. Choice D is incorrect because thalassemia is a separate genetic disorder affecting the production of hemoglobin, not related to the sickle cell trait.
What is a cause of the crystallization within the synovial fluid of the joint affected by gouty arthritis?
- A. Destruction of proteoglycans
- B. Underexcretion of uric acid
- C. Overexcretion of uric acid
- D. Increased absorption of uric acid
Correct Answer: B
Rationale: The correct answer is B: Underexcretion of uric acid. In gouty arthritis, the crystallization within the synovial fluid of the affected joint is caused by the underexcretion of uric acid, leading to the accumulation and subsequent crystallization of urate crystals. Choice A, destruction of proteoglycans, is incorrect as it is not directly related to the crystallization process in gouty arthritis. Choice C, overexcretion of uric acid, is incorrect because gout is primarily associated with underexcretion or decreased excretion of uric acid rather than overexcretion. Choice D, increased absorption of uric acid, is also incorrect as the primary issue in gouty arthritis is the body's inability to properly eliminate uric acid.