Biochemistry
1 questionsWhich organelle is primarily affected in Fabry's disease?
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 941: Which organelle is primarily affected in Fabry's disease?
- A. Endoplasmic Reticulum
- B. Lysosome (Correct Answer)
- C. Golgi apparatus
- D. Cell membrane
Explanation: ***Lysosome*** - Fabry's disease is a **lysosomal storage disorder** caused by a deficiency of the enzyme **alpha-galactosidase A**. - This enzyme deficiency leads to the accumulation of **globotriaosylceramide (Gb3)** within lysosomes in various cells throughout the body. *Endoplasmic Reticulum* - The **endoplasmic reticulum** is involved in protein synthesis and folding, and lipid metabolism. - While cellular stress from Gb3 accumulation can indirectly affect the ER, it is not the primary organelle involved in the storage of the accumulated substrate in Fabry's disease. *Golgi apparatus* - The **Golgi apparatus** modifies, sorts, and packages proteins and lipids. - It is not the site of primary pathology or substrate accumulation in lysosomal storage diseases. *Cell membrane* - The **cell membrane** regulates passage of substances into and out of the cell. - While lysosomal dysfunction can ultimately impact overall cell function, the cell membrane itself is not the organelle where the undigested substrate accumulates in Fabry's disease.
Community Medicine
1 questionsAll following are at-risk group adults meriting Hepatitis B vaccination in low endemic areas except for which of the following?
NEET-PG 2012 - Community Medicine NEET-PG Practice Questions and MCQs
Question 941: All following are at-risk group adults meriting Hepatitis B vaccination in low endemic areas except for which of the following?
- A. Medical/nursing personnel
- B. Patients with chronic liver disease
- C. Diabetics on insulin (Correct Answer)
- D. Patients on chronic hemodialysis
Explanation: ***Diabetics on insulin*** - This is the correct answer as the exception based on **guidelines at the time of this exam (2012)**. - At that time, diabetics were **not routinely listed** as a standard at-risk group for hepatitis B vaccination in low endemic areas, though the ACIP was beginning to recognize increased risk in this population. - **Current Update (Post-2012):** The **CDC/ACIP now recommends** hepatitis B vaccination for all previously unvaccinated adults with diabetes aged 19-59 years, due to documented increased risk of HBV infection associated with: - Shared blood glucose monitoring devices - Assisted blood glucose monitoring in healthcare settings - Outbreak investigations showing higher transmission rates - For the purpose of this historical exam question, diabetics were the exception among the listed groups. *Medical/nursing personnel* - Healthcare workers are at **high occupational risk** due to frequent exposure to blood and body fluids. - This has been a **standard, long-standing recommendation** for HBV vaccination regardless of endemic status. - The risk remains present even in low endemic areas due to potential exposure to infected patients. *Patients with chronic liver disease* - Individuals with pre-existing chronic liver disease are at risk of **severe outcomes** if they acquire hepatitis B infection. - Superimposed acute HBV infection can lead to: - Rapid progression to cirrhosis - Acute-on-chronic liver failure - Hepatocellular carcinoma - Vaccination is **crucial for prevention** and has been a standard recommendation. *Patients on chronic hemodialysis* - Hemodialysis patients face **elevated risk** of HBV acquisition due to: - Frequent vascular access procedures - Prolonged time in healthcare settings - Potential for nosocomial transmission in dialysis units - Their **immunocompromised state** increases risk of chronic infection and complications. - Vaccination is a **standard preventive measure** in this population.
Dermatology
1 questionsMuir–Torre syndrome shows
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 941: Muir–Torre syndrome shows
- A. Sebaceous gland tumors (Correct Answer)
- B. Intestinal polyps
- C. Lisch nodules
- D. Hyperelastic joints
Explanation: ***Sebaceous gland tumors*** - **Muir-Torre syndrome** is a genetic condition characterized by the presence of at least one **sebaceous gland tumor** (adenoma, epithelioma, or carcinoma) and at least one internal malignancy. - It is considered a variant of **Lynch syndrome (hereditary nonpolyposis colorectal cancer - HNPCC)**, stemming from germline mutations in **DNA mismatch repair genes**. *Intestinal polyps (associated with familial adenomatous polyposis)* - While Lynch syndrome (to which Muir-Torre is related) does involve an increased risk of colorectal cancer, **multiple intestinal polyps** are the hallmark of **Familial Adenomatous Polyposis (FAP)**. - FAP is caused by a mutation in the **APC gene**, distinct from the mismatch repair gene mutations seen in Muir-Torre syndrome. *Lisch nodules (associated with Neurofibromatosis type 1)* - **Lisch nodules** are benign **iris hamartomas** typically found in patients with **Neurofibromatosis type 1 (NF1)**. - NF1 is a neurocutaneous disorder caused by a mutation in the **NF1 gene**, presenting with café-au-lait spots, neurofibromas, and optic gliomas, which are unrelated to Muir-Torre syndrome. *Hyperelastic joints (associated with Ehlers-Danlos syndrome)* - **Hyperelasticity of joints** and skin is a characteristic feature of **Ehlers-Danlos syndrome (EDS)**, a group of heritable disorders affecting connective tissue. - EDS is caused by defects in **collagen synthesis or processing**, and its clinical manifestations are distinct from the mucocutaneous and internal malignancies seen in Muir-Torre syndrome.
Internal Medicine
3 questionsAn adult hypertensive male presented with sudden onset severe headache and vomiting. On examination, there is marked neck rigidity and no focal neurological deficit was found. The symptoms are most likely due to:
What is the most characteristic cerebrospinal fluid (CSF) finding in viral meningitis?
Which of the following statements is MOST accurate regarding herpes encephalitis?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 941: An adult hypertensive male presented with sudden onset severe headache and vomiting. On examination, there is marked neck rigidity and no focal neurological deficit was found. The symptoms are most likely due to:
- A. Subarachnoid hemorrhage (Correct Answer)
- B. Intracerebral hemorrhage
- C. Cerebral ischemia
- D. Bacterial meningitis
Explanation: ***Subarachnoid hemorrhage*** - The sudden onset of a **"thunderclap" headache**, vomiting, and **neck rigidity** in a hypertensive patient are classic signs of subarachnoid hemorrhage [1]. - The absence of focal neurological deficits is common, as the bleeding is often in the subarachnoid space rather than directly in brain tissue. *Intracerebral hemorrhage* - While it can cause sudden headache and vomiting, an **intracerebral hemorrhage** would typically present with **focal neurological deficits** corresponding to the affected brain region. - Neck rigidity is less common unless there's significant mass effect or ventricular involvement. *Cerebral ischemia* - **Cerebral ischemia** (e.g., ischemic stroke) usually manifests with **focal neurological deficits** (e.g., weakness, aphasia), often without a severe headache or neck rigidity [2]. - Headache, if present, is usually less severe and not described as "thunderclap." *Bacterial meningitis* - **Bacterial meningitis** presents with headache, fever, and neck rigidity [1], but the onset is typically **gradual** over hours to days, not sudden. - While vomiting can occur, the acute, thunderclap nature linked to hypertension points away from infection as the primary cause.
Question 942: What is the most characteristic cerebrospinal fluid (CSF) finding in viral meningitis?
- A. Lymphocytic pleocytosis in CSF (Correct Answer)
- B. WBC count typically less than 1000/mL
- C. Glucose levels normal or slightly decreased
- D. Protein levels normal or slightly increased
Explanation: ***Lymphocytic pleocytosis in CSF*** - **Lymphocytic pleocytosis**, meaning an increase in lymphocytes in the CSF, is the hallmark of **viral meningitis**, reflecting the immune response to the viral pathogen. [1] - While other CSF parameters can be altered, the presence of predominantly lymphocytes is the most reliable distinguishing feature from bacterial meningitis. [1] *WBC count typically less than 1000/mL* - This statement is generally true for viral meningitis, as the **WBC count** is usually lower than in bacterial meningitis. - However, it is not the *most characteristic* finding because bacterial meningitis can sometimes present with a WBC count under 1000/mL, especially early in the disease, and the *predominance* of lymphocytes is more specific to viral infection. *Glucose levels normal or slightly decreased* - **Normal glucose levels** are typical in viral meningitis, but they can be slightly decreased in a minority of cases. - This finding is not as characteristic as lymphocytic pleocytosis because significantly decreased glucose levels are more indicative of **bacterial or fungal meningitis**. *Protein levels normal or slightly increased* - **Protein levels** in viral meningitis are often normal or mildly elevated, usually not exceeding **100-150 mg/dL**. - While consistent with viral meningitis, this finding is less specific than lymphocytic pleocytosis, as protein levels can also be elevated in other conditions, including early bacterial meningitis.
Question 943: Which of the following statements is MOST accurate regarding herpes encephalitis?
- A. Focal neurological symptoms are common.
- B. EEG findings are nonspecific and not diagnostic.
- C. The temporal lobe is commonly involved. (Correct Answer)
- D. MRI is a key diagnostic tool.
Explanation: ***The temporal lobe is commonly involved.*** - **Herpes simplex encephalitis (HSE)** characteristically targets the **temporal lobes** [1] and **orbitofrontal cortex**, leading to specific neurological deficits. - This predilection for the temporal lobes often results in symptoms such as **aphasia**, **seizures**, and **memory disturbances** [1]. *Focal neurological symptoms are common.* - While focal neurological symptoms such as **aphasia**, **hemiparesis**, and **seizures** are indeed common in HSE [1], this statement is less specific than the involvement of the temporal lobe. - The **localization** of the infection to the temporal lobes explains why these focal symptoms are so prevalent [1]. *MRI is a key diagnostic tool.* - **MRI findings**, particularly **T2-weighted** and **FLAIR sequences**, showing **edema** and **hemorrhage** in the temporal lobes and insular cortex, are highly suggestive of HSE. - However, the most definitive diagnostic tool remains the detection of **HSV DNA** in the **cerebrospinal fluid (CSF)** via **PCR**. *EEG findings are nonspecific and not diagnostic.* - **EEG** in HSE often shows **periodic lateralizing epileptiform discharges (PLEDs)** or **focal slowing** primarily over the temporal lobes, which are highly suggestive, although not entirely diagnostic on their own. - These findings can help guide further investigation and support a clinical diagnosis in conjunction with other tests.
Pathology
1 questionsThe immunoglobulin most commonly involved in Multiple Myeloma is:
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 941: The immunoglobulin most commonly involved in Multiple Myeloma is:
- A. IgG (Correct Answer)
- B. IgM
- C. IgA
- D. IgD
Explanation: ***IgG*** - In Multiple Myeloma, the most commonly involved immunoglobulin is **IgG**, which is often produced in excess by malignant plasma cells [1][2]. - The presence of **monoclonal IgG** in serum is a key indicator of this malignancy, evident in diagnostic tests like serum protein electrophoresis. *IgM* - While **elevated IgM** levels can occur in other conditions like Waldenström's macroglobulinemia, it is not typically associated with Multiple Myeloma [2]. - IgM is produced by a different type of plasma cell and does not reflect the classic presentation of Multiple Myeloma. *IgA* - Although **IgA** can be involved in some cases of Multiple Myeloma, it is much less common than IgG [1][2]. - Patients with predominately **IgA Multiple Myeloma** are relatively rare compared to those with IgG. *IgD* - **IgD** myeloma is a very rare type of Multiple Myeloma, accounting for less than 2% of cases [1][2]. - It is not typically associated with the classic symptoms and conditions that characterize the more common IgG or IgA forms. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 608-609. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 616-617.
Pharmacology
1 questionsWhich of the following substances is known to cause predominantly sensory neuropathy?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 941: Which of the following substances is known to cause predominantly sensory neuropathy?
- A. Pyridoxine excess
- B. Suramin
- C. Cisplatin (Correct Answer)
- D. Vincristine
Explanation: ***Cisplatin*** - **Cisplatin** is a platinum-based chemotherapy drug well-known for causing **dose-dependent peripheral neuropathy**, primarily affecting sensory neurons. - Patients often present with **numbness**, **tingling**, and **loss of proprioception** in a glove-and-stocking distribution. - This is the **most characteristic** drug for **predominantly sensory neuropathy** among chemotherapeutic agents. *Pyridoxine excess* - While **pyridoxine (vitamin B6) excess** can cause sensory neuropathy, it is less commonly observed as a primary cause compared to cisplatin in the context of drug-induced neuropathies. - High doses of pyridoxine can lead to **dorsal root ganglionopathy**, affecting sensory nerve fibers. *Suramin* - **Suramin** is an anthelmintic agent primarily used for treating sleeping sickness, and it is known to cause a variety of side effects, including **renal toxicity** and **neurological symptoms**. - While neurological side effects can occur, they are not typically characterized as a **predominantly sensory neuropathy** in the same way as cisplatin. *Vincristine* - **Vincristine** is a vinca alkaloid chemotherapy agent that causes peripheral neuropathy. - However, vincristine typically causes **mixed motor and sensory neuropathy** with prominent motor involvement (foot drop, wrist drop). - This differs from cisplatin's **predominantly sensory** presentation.
Physiology
1 questionsTetany is seen in
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 941: Tetany is seen in
- A. Respiratory alkalosis (Correct Answer)
- B. Respiratory acidosis
- C. Metabolic acidosis
- D. Hyperkalemia
Explanation: ***Respiratory alkalosis*** - **Respiratory alkalosis** is caused by **hyperventilation**, which leads to a decrease in arterial partial pressure of carbon dioxide (**PaCO2**). - This decrease in PaCO2 causes an increase in pH (alkalemia) and a shift in the albumin-bound calcium equilibrium, reducing the amount of **ionized calcium** in the blood, leading to symptoms of **hypocalcemia** such as tetany. *Respiratory acidosis* - **Respiratory acidosis** is characterized by an increase in PaCO2 and a decrease in pH due to inadequate ventilation, which would not typically cause tetany. - In fact, the acidosis would tend to increase **ionized calcium** levels, thereby counteracting any tendency towards symptoms of hypocalcemia. *Metabolic acidosis* - **Metabolic acidosis** involves a decrease in bicarbonate concentration and pH, often due to conditions like diabetic ketoacidosis or lactic acidosis. - Similar to respiratory acidosis, the acidic environment of **metabolic acidosis** tends to increase **ionized calcium** levels, making tetany unlikely. *Hyperkalemia* - **Hyperkalemia** refers to elevated potassium levels in the blood, which primarily affects cardiac and neuromuscular function. - While it can cause muscle weakness and cardiac arrhythmias, it does not directly lead to **tetany**, which is a sign of **hypocalcemia**.
Surgery
1 questionsWhat is the standard intercostal space used for hepatic biopsy?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 941: What is the standard intercostal space used for hepatic biopsy?
- A. 5th
- B. 9th (Correct Answer)
- C. 7th
- D. 11th
Explanation: ***Correct Option: 9th*** - The **9th intercostal space** in the mid-axillary line is the standard and most commonly used entry point for percutaneous liver biopsy. - This location provides safe access to the **right lobe of the liver** while avoiding injury to the **pleura** and **lungs** superiorly and minimizing risk to the **kidney** and other abdominal organs inferiorly. - At this level, the liver is sufficiently large and the approach avoids the pleural reflection, which typically descends to the 8th-9th intercostal space. - Standard surgical textbooks (Sabiston, Schwartz) recommend the **8th-10th intercostal space**, with the 9th being most frequently used. *Incorrect Option: 5th* - The **5th intercostal space** is far too high for liver biopsy and would result in puncturing the **lung** or **pleura**, causing **pneumothorax** or hemothorax. - This space is well above the liver margin and is not suitable for hepatic access. *Incorrect Option: 7th* - While the **7th intercostal space** may occasionally be mentioned, it is generally considered **too high** for routine percutaneous liver biopsy. - This level carries increased risk of **pleural injury** as the pleural reflection may extend to this level, especially during deep inspiration. - It is not the standard or preferred approach in current surgical practice. *Incorrect Option: 11th* - The **11th intercostal space** is too low and significantly increases the risk of injuring the **right kidney** or entering the peritoneal cavity with potential injury to bowel or other abdominal structures. - This space is below the optimal liver access zone and is not recommended for routine liver biopsy.