NEET-PG 2013 Practice Questions

Q: Which of the following statements about Maple Syrup Urine Disease (MSUD) is true?

Deficiency of branched chain amino acid enzymes. ***Deficiency of branched chain amino acid enzymes*** - MSUD is caused by a deficiency in the **branched-chain alpha-keto acid dehydrogenase complex (BCKDC)**, an enzyme responsible for metabolizing **leucine, isoleucine, and valine**. - This enzyme deficiency leads to the accumulation of these **branched-chain amino acids (BCAAs)** and their corresponding branched-chain alpha-keto acids in the body. *Asymptomatic* - MSUD is a severe metabolic disorder that is **not asymptomatic**; it typically presents with distinct neurological and metabolic symptoms shortly after birth. - Clinical manifestations can include **poor feeding, lethargy, seizures**, and a characteristic **maple syrup odor** in urine and earwax. *FeCl3 turns navy blue* - The **ferric chloride test (FeCl3 test)** in MSUD typically yields a **green-gray or dark-green color** when testing for the accumulation of alpha-keto acids (specifically alpha-ketoisocaproic acid). - A **navy blue color** with FeCl3 is more characteristic of **alkaptonuria** due to the presence of homogentisic acid. *Hyperaminoaciduria of aromatic amino acids* - MSUD is characterized by the accumulation and excretion of **branched-chain amino acids (leucine, isoleucine, valine)** and their corresponding keto acids. - **Hyperaminoaciduria of aromatic amino acids** (e.g., phenylalanine, tyrosine, tryptophan) is seen in other conditions like **phenylketonuria (PKU)**, not MSUD.

Q: In Wilson's disease, copper deposition primarily occurs in which part of the brain?

Basal ganglia. ***Basal ganglia*** - The **basal ganglia**, particularly the **putamen** and **globus pallidus**, are the most common sites for copper deposition in the brain in Wilson's disease [1]. - This deposition leads to **neurological symptoms** such as dystonia [2], tremor, and dysarthria. *Pons* - While copper can accumulate in various brain regions, the **pons** is not a primary or characteristic site of significant copper deposition. - Neurological symptoms associated with pontine damage are not typical presenting features of Wilson's disease. *Cerebellum* - The **cerebellum** can show some copper accumulation in advanced stages, but it is not the primary site. - Cerebellar signs like **ataxia** can occur in Wilson's disease, but usually secondary to more widespread pathology rather than primary cerebellar copper deposition. *Medulla* - The **medulla oblongata** is generally spared from significant copper deposition in Wilson's disease. - Involvement of the medulla would typically manifest with severe autonomic or brainstem dysfunction, which is not a hallmark of early Wilson's disease.

Q: A 40-year-old male with gastroesophageal reflux disease (GERD) is found to have Barrett's esophagus with low-grade dysplasia on endoscopy. What is the most appropriate initial pharmacological treatment for this condition?

PPI. ***PPI*** - In patients with **GERD** and **low-grade dysplasia**, high-dose **proton pump inhibitors (PPIs)** are the initial treatment of choice to suppress acid reflux. - Continuous acid suppression can help in the regression of dysplasia and prevent its progression to higher grades. *Fundoplication* - **Fundoplication** is a surgical procedure to treat severe GERD, but it is not the primary initial treatment for low-grade dysplasia. - It might be considered if medical therapy with PPIs fails or if there are significant anatomical defects. *Esophageal resection* - **Esophageal resection** is a major surgical procedure typically reserved for **high-grade dysplasia** or **esophageal adenocarcinoma**. - It is an overly aggressive and unnecessary intervention for initial management of low-grade dysplasia. *Diet modification* - **Diet modification** is an important adjunctive therapy for GERD symptoms and overall gastric health. - However, it is generally insufficient as a standalone initial treatment for documented **low-grade dysplasia** without concurrent pharmacotherapy.

Q: What is the most common cause of acute tonsillitis?

Group A beta-hemolytic streptococci. ***Group A beta-hemolytic streptococci*** - **Group A Streptococcus (GAS)**, specifically *Streptococcus pyogenes*, is the most frequent bacterial cause of **acute tonsillitis** and pharyngitis, especially in school-aged children. - Infection can lead to complications such as **rheumatic fever** and **post-streptococcal glomerulonephritis** if not appropriately treated. *Streptococcus pneumoniae* - While *S. pneumoniae* is a common cause of **otitis media**, **sinusitis**, and **pneumonia**, it is less commonly the primary cause of acute tonsillitis. - It typically causes respiratory infections involving the lower airways or adjacent structures rather than primarily tonsillar inflammation. *H. Influenza* - *Haemophilus influenzae* is a significant pathogen for **otitis media**, **epiglottitis**, and **meningitis**, particularly in unvaccinated children. - It is not a common primary cause of acute tonsillitis, which is predominantly bacterial or viral. *Staphylococcus aureus* - *Staphylococcus aureus* is often associated with **skin and soft tissue infections**, as well as more serious conditions like **sepsis** and **endocarditis**. - Although it can cause pharyngeal infections, it is an infrequent cause of acute tonsillitis compared to Group A Streptococcus.

Q: In specular microscopy endothelial density is measured by?

Fixed frame analysis. ***Fixed frame analysis*** - This is the **standard method** used in specular microscopy to measure corneal endothelial cell density. - It involves analyzing a specific, fixed area of the **endothelial mosaic** and counting the number of cells within that defined frame. - The cell count from this fixed area is then **extrapolated** to calculate the overall endothelial cell density (cells/mm²). - This technique provides **quantitative assessment** of endothelial health, which is crucial for evaluating corneal function and pre-operative assessment for intraocular surgeries. *Optical doubling* - This is not a standard method for measuring endothelial density in specular microscopy. - Optical doubling relates to **refractive phenomena** or optical measurement techniques used in other contexts, not for endothelial cell counting. *Optical focusing* - While **essential for image acquisition**, optical focusing is merely a preliminary step to obtain a clear, sharp image of the endothelium. - It does not measure or count cells; it only ensures proper visualization before analysis. - The actual measurement requires subsequent **cell counting methods** like fixed frame analysis. *None of the options* - Incorrect because **fixed frame analysis** is indeed the recognized and widely used method for measuring endothelial density in specular microscopy.

Q: Which of the following antiglaucoma medications can cause drowsiness?

Brimonidine. ***Brimonidine*** - **Brimonidine** is an **alpha-2 adrenergic agonist** [1] that can cause central nervous system depression, leading to side effects such as **drowsiness** and fatigue. - This systemic side effect is more common with the topical ophthalmic formulation due to systemic absorption. *Latanoprost* - **Latanoprost** is a **prostaglandin analog** that primarily works by increasing uveoscleral outflow, and its side effects are mainly localized to the eye (e.g., iris color change, eyelash growth). - It does not typically cause systemic side effects like drowsiness because its systemic absorption is minimal. *Dorzolamide* - **Dorzolamide** is a **topical carbonic anhydrase inhibitor** [1] that reduces aqueous humor production, and its most common side effects include local ocular irritation and a bitter taste. - While systemic carbonic anhydrase inhibitors can cause fatigue and drowsiness, the topical formulation has very limited systemic absorption, making drowsiness uncommon. *Timolol* - **Timolol** is a **non-selective beta-blocker** [1] that reduces aqueous humor production and can cause systemic side effects such as bradycardia, bronchospasm, and hypotension. - While some beta-blockers can cause fatigue, **drowsiness** as a prominent side effect is less common compared to alpha-2 agonists.

Q: Metabolic change in severe vomiting is

Metabolic alkalosis due to loss of gastric acid. **Metabolic alkalosis due to loss of gastric acid** - Severe vomiting leads to the loss of **hydrochloric acid (HCl)** from the stomach, causing an increase in plasma bicarbonate and subsequently **metabolic alkalosis** [1], [3]. - This condition is often accompanied by **hypokalemia** due to renal compensation and increased aldosterone activity [1]. *Respiratory alkalosis due to hyperventilation* - **Hyperventilation** causes a decrease in arterial partial pressure of carbon dioxide (PaCO2), leading to **respiratory alkalosis** [2]. - While vomiting can sometimes cause mild hyperventilation due to discomfort, the primary metabolic derangement from severe vomiting is related to acid loss, not CO2 expulsion [4]. *Hyperkalemia due to renal dysfunction* - **Hyperkalemia** is an elevated potassium level, typically associated with **renal failure** or certain medications. - In severe vomiting, the loss of gastric fluid and subsequent fluid shifts tend to cause **hypokalemia** as the kidneys try to conserve hydrogen and excrete potassium [1]. *Metabolic acidosis due to renal failure* - **Metabolic acidosis** is characterized by a decrease in blood pH and bicarbonate, often caused by the accumulation of acids or loss of bicarbonate [3]. - **Renal failure** is a common cause of metabolic acidosis due to impaired acid excretion, which is not the primary issue in severe vomiting.

Q: Which condition is characterized by a specific radiological appearance resembling a sunburst pattern?

Osteosarcoma. ***Osteosarcoma*** - **Osteosarcoma** is known for its classic radiological findings, including the **sunburst (rising sun)** or **spiculated periosteal reaction**, where new bone forms perpendicular to the cortex. - Another characteristic finding is **Codman's triangle**, which is a triangular elevation of the periosteum visible on X-ray. *Chondrosarcoma* - **Chondrosarcomas** are typically characterized by a **"rings and arcs"** pattern of calcification within the cartilaginous matrix on imaging studies. - They tend to appear as lobular masses with endosteal scalloping and soft tissue components rather than the sunburst pattern. *Ewing's sarcoma* - **Ewing's sarcoma** classically presents with an **"onion skin" (lamellated)** periosteal reaction due to layers of parallel new bone formation. - It often appears as an ill-defined lytic lesion with cortical destruction, differing from the sunburst appearance. *Fibrosarcoma* - **Fibrosarcomas** are typically **lytic lesions** with aggressive cortical destruction and soft tissue involvement. - They generally do not produce characteristic periosteal reactions like the sunburst or onion skin appearance, often presenting as non-specific destructive lesions.

Q: The CT severity index in acute pancreatitis is described by:

Balthazar score. ***Balthazar score*** - The **Balthazar score** (or CT severity index) is a widely used radiological grading system for assessing the severity of **acute pancreatitis** based on findings on computed tomography (CT) scans. It evaluates both pancreatic inflammation and necrosis. - The Balthazar score helps predict the clinical course and potential complications of pancreatitis by assigning points for **pancreatic inflammation** and the extent of **necrosis**. *Mengini score* - The **Mengini score** is not a recognized CT severity index specifically for acute pancreatitis. - This name is not associated with any established scoring system in gastroenterology. *Chapman score* - The **Chapman score** refers to specific somatic points used in **osteopathic manipulative medicine** for diagnosis and treatment, primarily related to lymphatic system dysfunction. - It has no relevance to the radiological assessment or severity grading of acute pancreatitis. *Napelon score* - The **Napelon score** does not exist as a recognized medical scoring system, particularly in the context of acute pancreatitis or medical imaging. - This name is likely a distractor and not associated with medical practice.

Question 1

Which of the following statements about Maple Syrup Urine Disease (MSUD) is true?

Accepted Answer

Deficiency of branched chain amino acid enzymes

Answer

FeCl3 turns navy blue

Answer

Asymptomatic

Answer

Hyperaminoaciduria of aromatic amino acids

Question 2

In Wilson's disease, copper deposition primarily occurs in which part of the brain?

Accepted Answer

Basal ganglia

Answer

Cerebellum

Answer

Pons

Answer

Medulla

Question 3

34 week primigravida punjabi khatri comes with history of consanguineous marriage, with history of repeated blood transfusion to her sibling since 8 months of age. The first diagnostic test is -

Accepted Answer

Hb electrophoresis

Answer

HPLC

Answer

Bone marrow

Answer

Blood smear

Question 4

A 40-year-old male with gastroesophageal reflux disease (GERD) is found to have Barrett's esophagus with low-grade dysplasia on endoscopy. What is the most appropriate initial pharmacological treatment for this condition?

Accepted Answer

PPI

Answer

Fundoplication

Answer

Esophageal resection

Answer

Diet modification

Question 5

What is the most common cause of acute tonsillitis?

Accepted Answer

Group A beta-hemolytic streptococci

Answer

Streptococcus pneumoniae

Answer

H. influenzae

Answer

Staphylococcus aureus

Question 6

In specular microscopy endothelial density is measured by?

Accepted Answer

Fixed frame analysis

Answer

None of the options

Answer

Optical doubling

Answer

Optical focusing

Question 7

Which of the following antiglaucoma medications can cause drowsiness?

Accepted Answer

Brimonidine

Answer

Latanoprost

Answer

Dorzolamide

Answer

Timolol

Question 8

Metabolic change in severe vomiting is

Accepted Answer

Metabolic alkalosis due to loss of gastric acid

Answer

Respiratory alkalosis due to hyperventilation

Answer

Hyperkalemia due to renal dysfunction

Answer

Metabolic acidosis due to renal failure

Question 9

Which condition is characterized by a specific radiological appearance resembling a sunburst pattern?

Accepted Answer

Osteosarcoma

Answer

Chondrosarcoma

Answer

Fibrosarcoma

Answer

Ewing's sarcoma

Question 10

The CT severity index in acute pancreatitis is described by:

Accepted Answer

Balthazar score

Answer

Mengini score

Answer

Chapman score

Answer

Napelon score

NEET-PG 2013

Biochemistry

Internal Medicine

Microbiology

Ophthalmology

Pharmacology

Physiology

Radiology