Biochemistry
1 questionsWhich organelle is primarily affected in Fabry's disease?
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 851: 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.
Dermatology
1 questionsMuir–Torre syndrome shows
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 851: 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 questionsWhat is the most characteristic cerebrospinal fluid (CSF) finding in viral meningitis?
Which of the following statements is MOST accurate regarding herpes encephalitis?
Esophageal manometry is useful in diagnosing all of the following conditions EXCEPT:
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 851: 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 852: 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.
Question 853: Esophageal manometry is useful in diagnosing all of the following conditions EXCEPT:
- A. Achalasia (a motility disorder)
- B. Diffuse esophageal spasm (a motility disorder)
- C. Malignancy (not typically diagnosed with this test) (Correct Answer)
- D. Assessment of esophageal motility prior to surgery for GERD
Explanation: ***Malignancy (not typically diagnosed with this test)*** - **Esophageal manometry** evaluates the **motor function** of the esophagus, measuring pressure changes during swallowing. - **Malignancy**, such as esophageal cancer, is primarily diagnosed with **endoscopy with biopsy** and imaging studies, not by assessing motility. *Achalasia (a motility disorder)* - **Esophageal manometry** is the **gold standard** for diagnosing achalasia, characterized by **absent peristalsis** in the esophageal body and **incomplete relaxation of the lower esophageal sphincter (LES)** [1]. - High-resolution manometry shows elevated **integrated relaxation pressure (IRP)** and often pan-esophageal pressurization. *Diffuse esophageal spasm (a motility disorder)* - This condition is also diagnosed by **esophageal manometry**, which reveals simultaneous, **non-peristaltic contractions** of high amplitude, often interspersed with normal peristalsis [1]. - It may also show **premature contractions** and **multiple rapid swallows** triggering spasm. *Assessment of esophageal motility prior to surgery for GERD* - **Manometry** is routinely performed before **anti-reflux surgery (e.g., Nissen fundoplication)** to rule out underlying esophageal motility disorders that could complicate surgery or worsen symptoms post-operatively [1]. - Identifying conditions like **achalasia** or **scleroderma** would contraindicate a standard fundoplication, as dysphagia could worsen [1].
Pathology
1 questionsThe immunoglobulin most commonly involved in Multiple Myeloma is:
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 851: 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.
Physiology
1 questionsTetany is seen in
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 851: 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**.
Radiology
1 questionsStep ladder pattern of gas shadow is seen in
NEET-PG 2012 - Radiology NEET-PG Practice Questions and MCQs
Question 851: Step ladder pattern of gas shadow is seen in
- A. Intestinal obstruction (Correct Answer)
- B. Gastric outlet obstruction
- C. Duodenal obstruction
- D. Sigmoid volvulus
Explanation: ***Intestinal obstruction*** - A **step-ladder pattern** of gas shadows is a classic radiological sign seen in **small bowel obstruction** due to dilated, fluid-filled loops of small bowel stacked on top of each other. - This pattern results from the accumulation of gas and fluid proximal to the obstruction, causing dilated bowel loops to arrange horizontally. *Gastric outlet obstruction* - This condition primarily results in a **dilated stomach** with fluid and gas, not typically a step-ladder pattern in the small bowel. - Vomiting is usually a prominent symptom, and imaging would show a large fluid-filled stomach. *Duodenal obstruction* - Causes dilatation of the stomach and duodenum, leading to a "**double-bubble sign**" (dilated stomach and proximal duodenum). - It does not typically produce the extensive, stacked small bowel loops seen in a step-ladder pattern. *Sigmoid volvulus* - Characterized by a distinctive large, dilated loop of sigmoid colon, often described as a "**coffee bean sign**" or an **inverted U-shape**. - This is a large bowel obstruction and does not typically present with a step-ladder pattern of small bowel gas.
Surgery
2 questionsRoad traffic accident (RTA) with multiple fractures - initial treatment would be:
What type of burn is characterized by flash burn, tenderness, redness, and pain?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 851: Road traffic accident (RTA) with multiple fractures - initial treatment would be:
- A. Management of shock
- B. Splinting of limbs
- C. Airway management (Correct Answer)
- D. Cervical spine protection
Explanation: ***Airway management*** - In trauma, **establishing and maintaining a patent airway** is the absolute priority, as compromised breathing can lead to rapid deterioration and death. - The **ABCs (Airway, Breathing, Circulation)** of trauma care dictate that airway intervention precedes other life-saving measures. *Management of shock* - While crucial, **managing shock (C)** follows **airway (A)** and **breathing (B)** in the primary survey of trauma care. - Addressing profound shock without a patent airway can be ineffective and leads to irreversible damage. *Splinting of limbs* - **Splinting fractures** is important for pain control, preventing further injury, and minimizing blood loss in open fractures, but it is not an immediate life-saving intervention. - This falls under the **secondary survey** or definitive management, after life-threatening issues have been addressed. *Cervical spine protection* - **Cervical spine protection** is essential in trauma to prevent further neurological injury and is performed simultaneously with airway management (often with in-line stabilization). - However, a patent airway is the **most immediate life-sustaining intervention** if the airway is compromised.
Question 852: What type of burn is characterized by flash burn, tenderness, redness, and pain?
- A. Scalded burn
- B. First degree burn (Correct Answer)
- C. Second degree burn
- D. Fourth degree burn
Explanation: ***First degree burn*** - Characterized by **tenderness**, **redness**, and **pain** without blistering. - Involves only the **epidermis**, typically from a **flash burn** or brief contact with a hot object. *Scalded burn* - A type of burn caused by **hot liquid or steam**, not a characteristic of a specific burn depth. - Can be superficial or deep, depending on the **temperature** and **duration of exposure**. *Second degree burn* - Involves the **epidermis and dermis**, presenting with **blisters**, severe pain, and sometimes a wet, weeping appearance. - Often heals with scarring, unlike first-degree burns. *Fourth degree burn* - The most severe type of burn, extending through **all layers of skin** into underlying **muscle**, **tendons**, or **bone**. - Often appears charred or black, and victims may feel little pain due to extensive nerve damage.