Which of the following does not synthesize von Willebrand factor?
Primary hypercholesterolemia is:
What is the complete classic triad of findings that defines Young's syndrome?
Most common cause of death in SLE in children
Creatine kinase is elevated in MI after
Which HLA antigen is associated with thromboangitis obliterans?
Which of the following is NOT a feature of Peutz-Jeghers syndrome?
What is the most common location of gastrinoma?
Which one of the following is the most common CNS tumor associated with type I neurofibromatosis?
Cryoprecipitate is useful in which of the following conditions?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 21: Which of the following does not synthesize von Willebrand factor?
- A. Endothelial cells
- B. Hepatocytes (Correct Answer)
- C. Megakaryocytes
- D. None of the options
Explanation: ***Hepatocytes*** - Von Willebrand factor (vWF) is primarily synthesized by **endothelial cells** and **megakaryocytes** [1], not hepatocytes. - Hepatocytes are responsible for synthesizing other proteins like **clotting factors**, but not vWF. *Megakaryoctyes* - Megakaryocytes play a crucial role in the synthesis of **platelet-derived factors**, including von Willebrand factor (vWF) [1]. - They release vWF into the bloodstream, facilitating platelet adhesion, especially in vascular injury sites. *None* - The option implies all listed cell types synthesize vWF, which is incorrect, as **only endothelial cells and megakaryocytes** produce it [1]. - Suggests a misunderstanding of the synthesis of coagulation-related factors, as hepatocytes do not produce vWF. *Endothelial cells* - Endothelial cells are the primary source of **von Willebrand factor** [1], releasing it to assist in platelet aggregation and clotting. - They are essential for the body's response to vascular injury, facilitating hemostasis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 669-670.
Question 22: Primary hypercholesterolemia is:
- A. Type I
- B. Type IIb
- C. Type IIa (Correct Answer)
- D. Type III
Explanation: ***Type Ha*** - **Primary hypercholesterolemia** specifically refers to **Familial Hypercholesterolemia**, which is classified as Type Ha due to a genetic defect affecting LDL receptor activity [1]. - It typically presents with **high cholesterol levels** and an increased risk of premature cardiovascular disease [1]. *Type I* - Type I hyperlipoproteinemia is associated with **chylomicronemia**, leading to elevated triglycerides rather than cholesterol. - Symptoms include **pancreatitis** and eruptive xanthomas, not primarily high cholesterol levels. *Type III* - Type III hyperlipoproteinemia is known as **Dysbetalipoproteinemia**, associated with **increased IDL** and can cause elevated cholesterol, but is not classified as primary hypercholesterolemia. - It typically presents with **tuberous xanthomas** and is linked to **apolipoprotein E deficiency**. *Type IIb* - Type IIb hyperlipoproteinemia involves **elevation of LDL and VLDL**, but it is not classified as primary hypercholesterolemia; it is a mixed dyslipidemia. - This type usually features **increased cholesterol** and **triglycerides**, distinguishing it from the familial form classified as Type Ha.
Question 23: What is the complete classic triad of findings that defines Young's syndrome?
- A. Azoospermia, bronchiectasis, and chronic sinusitis (Correct Answer)
- B. Oligospermia, bronchiectasis, and chronic sinusitis
- C. Azoospermia, asthma, and chronic rhinitis
- D. Azoospermia, chronic bronchitis, and nasal polyps
Explanation: ***Azoospermia, bronchiectasis, and chronic sinusitis*** - Young's syndrome is characterized by the triad of **azoospermia** (due to obstructive epididymal dysfunction), **bronchiectasis**, and **chronic sinusitis** [1]. - This syndrome primarily affects **middle-aged men** and is often mistaken for cystic fibrosis due to similar respiratory symptoms. *Azoospermia, asthma, and chronic rhinitis* - This option incorrectly lists **asthma** and **chronic rhinitis** instead of bronchiectasis and chronic sinusitis. - While respiratory symptoms are part of Young's syndrome, specifically **bronchiectasis** and **sinusitis** are key [1]. *Oligospermia, bronchiectasis, and chronic sinusitis* - This option is incorrect because Young's syndrome is defined by **azoospermia** (complete absence of sperm), not just **oligospermia** (low sperm count). - The obstructive nature of the epididymal dysfunction in Young's syndrome leads to a complete lack of sperm. *Azoospermia, chronic bronchitis, and nasal polyps* - This option incorrectly identifies **chronic bronchitis** and **nasal polyps** as part of the classic triad. - The correct respiratory components are **bronchiectasis** and **chronic sinusitis**, which signify persistent inflammation and structural lung changes rather than simply bronchitis.
Question 24: Most common cause of death in SLE in children
- A. Libman sacks endocarditis
- B. Lupus cerebritis
- C. Lupus nephritis
- D. Anemia and infections (Correct Answer)
Explanation: ***Anemia and infections*** - **Infections** are a leading cause of death in pediatric SLE patients, often due to immunosuppression from the disease itself or its treatment. Although pediatric Systemic Lupus Erythematosus (SLE) is not a primary immune deficiency, the susceptibility to encapsulated bacteria and recurrent infections seen in primary B- and T-lymphocyte deficiencies mirrors the infection risks managed in these patients [1]. - **Anemia** can contribute to overall morbidity and mortality, although it is less directly a cause of death than severe infections or organ failure. *Lupus nephritis* - While **lupus nephritis** is a common and severe manifestation of SLE in children and a major cause of morbidity, particularly long-term kidney failure, it is not the most frequent immediate cause of death. - Advancements in treatment for nephritis have improved prognosis, shifting the leading cause of mortality to other factors. *Lupus cerebritis* - **Lupus cerebritis** (neuropsychiatric SLE) can be life-threatening, causing seizures, stroke, or psychosis, but it is less common as the primary cause of death compared to infections. - Its presence usually indicates severe disease requiring intensive treatment, but not the most common direct cause of death. *Libman sacks endocarditis* - **Libman-Sacks endocarditis** involves sterile vegetations on heart valves and is a known complication of SLE, but it rarely causes acute mortality in children. - It is more often associated with chronic complications like valvular dysfunction or a source of emboli rather than being the most common cause of death.
Question 25: Creatine kinase is elevated in MI after
- A. 4-8 hours
- B. >24 hours
- C. 12-24 hours
- D. 2-4 hours (Correct Answer)
Explanation: ***2-4 hours*** - **Creatine kinase (CK)** levels typically begin to rise within **2-4 hours** after the onset of myocardial infarction. - This early elevation makes CK an effective, though non-specific, marker for **acute MI** in the initial stages [1]. *4-8 hours* - While CK levels may continue to rise during this period, the initial measurable elevation usually occurs earlier, within **2-4 hours**. - A significant elevation at 4-8 hours would indicate that the myocardial event occurred at least several hours prior. *12-24 hours* - Creatine kinase levels typically peak much earlier, between **12-24 hours**, rather than just beginning to elevate at this time. - By this time, other more specific markers like **troponins** would also be significantly elevated and are often preferred for diagnosis [1], [2]. *>24 hours* - Beyond 24 hours, CK levels usually start to decline, making it less useful for the initial detection of an acute MI that began many hours earlier. - For events occurring over 24 hours ago, a positive CK would indicate that the event had happened, but it's not the first time it would be elevated.
Question 26: Which HLA antigen is associated with thromboangitis obliterans?
- A. HLA-B27
- B. HLA-DR4
- C. HLA-B5 (Correct Answer)
- D. HLA-DR2
Explanation: HLA-B5 - **HLA-B5** (specifically **HLA-B51**) has been associated with an increased risk of **thromboangiitis obliterans (Buerger's disease)** in some populations. - This association suggests a potential genetic predisposition, although the disease's primary risk factor remains **smoking**. *HLA-B27* - **HLA-B27** is strongly associated with **spondyloarthropathies**, such as **ankylosing spondylitis** and **reactive arthritis**, not thromboangiitis obliterans [1]. - Its presence indicates a genetic susceptibility to inflammatory arthritic conditions primarily affecting the spine and sacroiliac joints [1]. *HLA-DR4* - **HLA-DR4** is a well-known genetic marker associated with **rheumatoid arthritis**, particularly severe forms. - It is also linked to other autoimmune diseases like **Type 1 Diabetes**, but not thromboangiitis obliterans. *HLA-DR2* - **HLA-DR2** is associated with an increased risk of several autoimmune diseases, most notably **multiple sclerosis** and **narcolepsy**. - While it plays a role in immune regulation, it is not specifically linked to thromboangiitis obliterans.
Question 27: Which of the following is NOT a feature of Peutz-Jeghers syndrome?
- A. Mucocutaneous pigmentation
- B. Autosomal recessive inheritance (Correct Answer)
- C. Autosomal dominant
- D. Hamartomatous polyp
Explanation: ***High risk of malignancy*** - Peutz-Jeghers syndrome is primarily associated with **benign hamartomatous polyps**, not a **high risk of malignancy**, which distinguishes it from other syndromes. - Although patients may develop cancers [1], the syndrome itself does not inherently denote a high malignancy risk like other syndromes such as familial adenomatous polyposis. *Autosomal dominant* - This syndrome is indeed **autosomal dominant**, caused by mutations in the STK11 gene. - Families with this condition typically show **vertical transmission**, characteristic of autosomal dominant inheritance. *Hamartomatous polyp* - Individuals with Peutz-Jeghers syndrome develop **hamartomatous polyps**, which are a hallmark feature of the condition [1]. - These polyps can occur in the gastrointestinal tract and are benign lesions rather than adenomatous type seen in other syndromes [1]. *Mucocutaneous pigmentation* - Mucocutaneous pigmentation, such as **freckling around the lips and buccal mucosa**, is a key clinical feature of Peutz-Jeghers syndrome. - This pigmentation usually appears in childhood and is often a distinguishing sign of the syndrome.
Question 28: What is the most common location of gastrinoma?
- A. Pancreas
- B. Duodenum (Correct Answer)
- C. Jejunum
- D. Gall bladder
Explanation: ***Duodenum*** - The **duodenum** is the most common site for gastrinomas, accounting for over **half of all cases**, particularly in sporadic gastrinoma and Zollinger-Ellison syndrome. - These tumors are often **small** and **multiple** in the duodenum, making them challenging to locate. *Pancreas* - Pancreatic gastrinomas are also common, representing approximately **25-40% of cases**, but are less frequent than duodenal gastrinomas. - Pancreatic gastrinomas tend to be **larger** and more amenable to surgical resection when compared to duodenal gastrinomas. *Jejunum* - Gastrinomas found in the jejunum are **rare**, accounting for only a small percentage of cases. - The small intestine distal to the duodenum is an **uncommon site** for primary gastrinoma formation. *Gall bladder* - The **gallbladder** is not a typical location for gastrinoma development. - Gastrinomas are neuroendocrine tumors that arise from **gastrin-producing cells**, which are not found in the gallbladder.
Question 29: Which one of the following is the most common CNS tumor associated with type I neurofibromatosis?
- A. Optic nerve glioma (Correct Answer)
- B. Meningioma
- C. Acoustic schwannoma
- D. Low grade astrocytoma
Explanation: ***Optic nerve glioma*** - **Optic nerve gliomas** are the most frequently encountered central nervous system tumors in patients with **Type 1 neurofibromatosis (NF1)**, occurring in about 15% of individuals. - They are typically low-grade **astrocytomas** and can cause vision loss and proptosis depending on their size and location. *Meningioma* - While more common in **Type 2 neurofibromatosis (NF2)**, meningiomas can occur in NF1, but are not the most common CNS tumor. - Meningiomas are tumors that arise from the **meninges**, the membranes surrounding the brain and spinal cord. *Acoustic schwannoma* - **Bilateral acoustic schwannomas (vestibular schwannomas)** are the hallmark feature of **Type 2 neurofibromatosis (NF2)**, not NF1 [1]. - These tumors arise from the Schwann cells of the **vestibulocochlear nerve** and can cause hearing loss and balance issues [1]. *Low grade astrocytoma* - While optic nerve gliomas are a type of low-grade astrocytoma, this option is too general; **optic nerve glioma** is the specific and most common presentation in NF1. - Other forms of low-grade astrocytomas can occur in NF1 but are not as universally characteristic as optic nerve gliomas.
Question 30: Cryoprecipitate is useful in which of the following conditions?
- A. Hemophilia A
- B. Thrombosthenia
- C. Warfarin reversal
- D. Afibrinogenemia (Correct Answer)
Explanation: ***Afibrinogenemia*** - Cryoprecipitate is rich in **fibrinogen**, factor VIII, factor XIII, von Willebrand factor, and fibronectin. It is the only blood product with a substantial concentration of fibrinogen. - **Afibrinogenemia** (or hypofibrinogenemia) is a condition characterized by low or absent levels of fibrinogen, a critical clotting factor that cryoprecipitate replaces effectively. *Hemophilia A* - Hemophilia A is a deficiency of **Factor VIII**. While cryoprecipitate contains factor VIII, **recombinant Factor VIII concentrates** are the preferred treatment due to better safety (reduced risk of viral transmission) and more precise dosing [1]. - Cryoprecipitate was historically used for Hemophilia A before the availability of safer, more specific factor concentrates [2]. *Thrombosthenia* - Thrombasthenia is a platelet function disorder characterized by defective **glycoprotein IIb/IIIa receptors** on platelets, leading to impaired platelet aggregation. - Cryoprecipitate does not contain platelets or factors that directly correct platelet function, making **platelet transfusions** the treatment of choice for severe bleeding in thrombasthenia. *Warfarin reversal* - Warfarin reversal is primarily achieved using **Vitamin K**, which restores levels of functional clotting factors II, VII, IX, and X. - For rapid reversal in emergencies, **prothrombin complex concentrate (PCC)** is preferred because it contains high concentrations of these vitamin K-dependent factors, addressing the primary deficiency caused by warfarin [1].