NEET-PG 2018 Practice Questions

Q: Fish odor syndrome is caused by deficiency of which enzyme?

Flavin-containing monooxygenase 3 (FMO3). ***Flavin-containing monooxygenase 3 (FMO3)*** - **Trimethylaminuria**, or "fish odor syndrome," is caused by a genetic defect in the **FMO3 enzyme**. - This enzyme is responsible for converting **trimethylamine (TMA)**, a breakdown product of certain foods, into an odorless form, **trimethylamine N-oxide (TMAO)**. *Fumarylacetoacetate hydrolase* - Deficiency in this enzyme causes **Tyrosinemia type 1**, a metabolic disorder affecting tyrosine metabolism. - It leads to severe liver disease, kidney dysfunction, and neurological crises, not a fishy body odor. *Methane monooxygenase* - This enzyme is found in certain **bacteria** (methanotrophs) and is involved in the metabolism of methane. - It is not present in humans and has no known link to human metabolic disorders like fish odor syndrome. *D-amino acid oxidase* - This enzyme is involved in the metabolism of **D-amino acids**, which are less common in mammals but found in bacteria and some foods. - Its deficiency is not associated with trimethylaminuria or a fishy body odor.

Q: Which condition is associated with the ECG pattern known as pseudo P pulmonale?

Hypercalcemia. ***Hypercalcemia*** - **Hypercalcemia** can cause a characteristic ECG pattern known as pseudo P pulmonale due to its effects on **myocardial repolarization**. - This condition leads to a **shortened QT interval** which causes the T wave to merge with the P wave, giving the appearance of a tall, peaked P wave. *Hypokalemia* - **Hypokalemia** typically presents with **flattened T waves**, prominent U waves, and ST-segment depression on an ECG [1]. - It can prolong repolarization, which is the opposite effect observed with pseudo P pulmonale [1]. *Hyponatremia* - **Hyponatremia** has a less defined direct effect on ECG patterns compared to other electrolyte imbalances. - Severe hyponatremia may lead to **QRS widening** or **bradycardia**, but not pseudo P pulmonale [1]. *Hypocalcemia* - **Hypocalcemia** characteristically causes **prolongation of the QT interval** on an ECG due to delayed ventricular repolarization [2]. - This is distinct from the shortened QT seen in hypercalcemia that contributes to pseudo P pulmonale.

Q: What is a potential cause of cardiogenic shock other than myocardial infarction (MI)?

Acute mitral regurgitation. ***Acute mitral regurgitation*** - **Acute mitral regurgitation** is a severe form of valvular heart disease where the mitral valve fails to close properly, leading to a sudden backflow of blood into the left atrium during systole. [1] - This significantly reduces **forward cardiac output** and increases left atrial pressure, which can rapidly lead to pulmonary edema and cardiogenic shock, even in the absence of MI. [1] *Ventricular septal rupture* - While a **ventricular septal rupture** can cause cardiogenic shock, it is typically a **complication of myocardial infarction**, meaning it would fall under MI as the underlying cause. [2] - This condition involves a hole in the septum separating the ventricles, leading to a shunt and increased workload on the right ventricle, causing cardiogenic shock. *Isolated right ventricular shock* - **Isolated right ventricular shock** is often caused by conditions like a **massive pulmonary embolism** or a right ventricular infarction. [2] - While it can lead to shock, it is distinct from general cardiogenic shock which often implies left ventricular dysfunction or severe myocardial compromise, and the question asks for a cause *other than* MI, which can cause right ventricular shock. *None of the options* - This option is incorrect because **acute mitral regurgitation** is a distinct and significant cause of cardiogenic shock, independent of MI. [1]

Q: Which of the following is the carrying agent for Lyme disease?

Ixodes scapularis ticks. ***Ixodes scapularis ticks*** - *Ixodes scapularis* ticks (deer ticks) are the primary **vectors for Lyme disease** (caused by *Borrelia burgdorferi*) in North America [1]. - In Europe, *Ixodes ricinus* is the main vector for Lyme disease. - Lyme disease presents with characteristic **erythema migrans** rash, followed by potential neurological, cardiac, and arthritic complications [1]. - Lyme arthritis commonly affects large joints, particularly the **knee**, causing inflammatory arthritis [1]. *Anopheles* - **Anopheles mosquitoes** are the primary vectors for **malaria**, not Lyme disease [2]. - Malaria is caused by *Plasmodium* parasites and presents with fever, chills, and hemolytic anemia [2]. *Louse* - **Lice** are vectors for diseases such as **epidemic typhus** (caused by *Rickettsia prowazekii*) and **relapsing fever** (caused by *Borrelia recurrentis*) [3]. - They are not associated with the transmission of Lyme disease. *Rat flea* - **Rat fleas** (e.g., *Xenopsylla cheopis*) are the primary vectors for **bubonic plague** (caused by *Yersinia pestis*) and **murine typhus**. - These insects do not transmit Lyme disease. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 389-390. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, p. 400. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 392-393.

Q: A red soft to firm swelling on the sternum shows proliferation of endothelial cells forming vascular channels on biopsy. What is the most likely diagnosis?

Hemangioma. ***Hemangioma*** - The soft to firm swelling and histological findings indicative of vascular spaces are characteristic of a **hemangioma**, often presenting as a benign vascular tumor [1][2]. - Commonly found in the **sternum**, it may show red or bluish discoloration and typically undergoes a **biopsy** revealing endothelial cell proliferation [2]. *Osteochondroma* - This is a **benign bone tumor** that arises from the growth plate but typically presents as a hard, bony mass rather than a soft swelling. - Histologically, it shows **cartilaginous cap** and is associated with bone rather than vascular structures. *Osteoid osteoma* - Usually presents as a **painful, small bone lesion** often found in the long bones, generally not in the sternum and characterized by a **nidus** of osteoid. - The biopsy would show a **central nidus** with osteoid and woven bone, not consistent with soft swellings. *Paget disease* - This chronic bone disorder involves excessive bone remodeling, leading to enlarged and deformed bones rather than a discrete swelling. - Histologically, it would show **disorganized bone** formation and is not associated with soft or firm masses like hemangiomas. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 481-482. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 523-524.

Q: Positive periodic acid-Schiff (PAS) macrophages are seen in which of the following conditions?

Whipple's disease. ***Whipple's disease*** - **Whipple's disease** is caused by the bacterium *Tropheryma whipplei*, which is ingested by macrophages and accumulates in their lysosomes [1]. - The bacterial cell wall contains **glycoproteins** and **proteoglycans** that stain magenta (red-purple) with the **periodic acid-Schiff (PAS)** stain. - PAS-positive, diastase-resistant macrophages in the lamina propria of the small intestine are **pathognomonic** for Whipple's disease [1]. *Crohn's disease* - Crohn's disease is an **inflammatory bowel disease** characterized by transmural inflammation and non-caseating granulomas. - While it involves macrophages in the inflammatory process, they do not typically show **PAS-positive inclusions**. *HIV/AIDS* - HIV/AIDS is a **viral infection** that primarily targets CD4+ T lymphocytes and macrophages. - Although macrophages are involved in HIV infection and can be found in intestinal tissue, they do not exhibit **PAS-positive inclusions** characteristic of Whipple's disease. *Celiac disease* - Celiac disease is an **autoimmune enteropathy** triggered by gluten, causing villous atrophy and malabsorption. - The histology shows increased intraepithelial lymphocytes and crypt hyperplasia, but **macrophages are not PAS-positive**. - Both Whipple's and celiac disease can present with malabsorption, making clinical differentiation important [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 798-799.

Q: Anaerobes are resistant intrinsically against which of the following?

Aminoglycosides. ***Aminoglycosides*** - **Aminoglycosides** require an **oxygen-dependent transport system** to enter bacterial cells. [3] - Since **anaerobes** thrive in low-oxygen environments, this transport system is inactive, making them intrinsically resistant to aminoglycosides. [3] *Azithromycin* - **Azithromycin** (a macrolide) inhibits protein synthesis by binding to the 50S ribosomal subunit. - Many anaerobes are susceptible to **azithromycin**, making it an effective treatment for certain anaerobic infections. *Metronidazole* - **Metronidazole** is a potent prodrug that requires reduction by **anaerobic metabolism** to become active. [1], [2] - Its mechanism of action involves creating **cytotoxic free radicals** that damage DNA, making it highly effective against most anaerobes. [2] *Beta lactam antibiotics* - **Beta-lactam antibiotics**, such as **penicillins** and **cephalosporins**, interfere with bacterial cell wall synthesis. - While some anaerobes are susceptible, others have developed resistance mechanisms like producing **beta-lactamase enzymes**, but they are not intrinsically resistant across the board. [4]

Q: What is the current preferred term for the condition previously known as mental retardation?

Intellectual disability. ***Correct: Intellectual disability*** - This term was adopted to replace "mental retardation" due to its less stigmatizing nature and its focus on **cognitive and adaptive functioning** - It emphasizes the need for supports and services to help individuals achieve their potential, rather than simply labeling a deficit - Officially adopted in **DSM-5 (2013)** and mandated by **Rosa's Law (2010)** in federal terminology *Incorrect: Feeble Mindedness* - This is an **outdated and derogatory term** that was used historically to describe individuals with cognitive impairments - Its use has been discontinued due to its negative and dehumanizing connotations *Incorrect: Madness* - This term typically refers to severe **mental illness** or **psychosis**, not intellectual impairment - It is an informal and often stigmatizing term that is not used in clinical or diagnostic contexts for intellectual functioning *Incorrect: Mentally unstable* - This term is often used to describe individuals experiencing **fluctuations in mood**, **behavior**, or **thought processes**, usually associated with mental health conditions - It does not specifically refer to global cognitive deficits or intellectual functioning

Q: Which of the following statements about the management of haematomas is NOT correct?

Haematoma must be operated.. ***Haematoma must be operated.*** - This statement is **incorrect** because not all hematomas require surgical intervention. - The decision to operate depends on **size**, **location**, **neurological status**, **mass effect**, and rate of expansion. - Small, asymptomatic hematomas can be managed **conservatively** with serial imaging and close neurological monitoring. - Absolute statements like "must be operated" are incorrect in clinical practice where individualized management is essential. *Some haematomas require surgical intervention.* - This statement is **correct** - many hematomas necessitate surgical evacuation. - Indications for surgery include: **significant mass effect**, **midline shift >5mm**, **neurological deterioration**, **large volume** (>30mL for SDH, >50mL for ICH), or **posterior fossa hematomas** causing brainstem compression. - Surgical intervention aims to relieve intracranial pressure and prevent secondary brain injury. *GCS assessment is helpful in prognosis.* - This statement is **correct** - the **Glasgow Coma Scale (GCS)** is a critical prognostic tool. - GCS is used to assess severity of neurological injury and predict outcomes in head trauma patients. - Lower GCS scores (≤8) indicate severe injury with poorer prognosis, while higher scores suggest better outcomes. - GCS also guides management decisions including need for intubation and intensive monitoring. *CT scan is the investigation of choice for acute haemorrhage.* - This statement is **correct** - **Non-contrast CT (NCCT)** is the gold standard for acute intracranial hemorrhage. - CT is rapid, widely available, and highly sensitive for detecting acute blood. - It helps identify location, size, mass effect, and associated injuries like skull fractures. - MRI has limited role in acute settings but is useful for subacute/chronic hemorrhage and detecting diffuse axonal injury.

Question 1

Fish odor syndrome is caused by deficiency of which enzyme?

Accepted Answer

Flavin-containing monooxygenase 3 (FMO3)

Answer

Fumarylacetoacetate hydrolase

Answer

Methane monooxygenase

Answer

D-amino acid oxidase

Question 2

Which condition is associated with the ECG pattern known as pseudo P pulmonale?

Accepted Answer

Hypercalcemia

Answer

Hyponatremia

Answer

Hypocalcemia

Answer

Hypokalemia

Question 3

What is a potential cause of cardiogenic shock other than myocardial infarction (MI)?

Accepted Answer

Acute mitral regurgitation

Answer

Ventricular septal rupture

Answer

Isolated right ventricular shock

Answer

None of the options

Question 4

Which of the following is the carrying agent for Lyme disease?

Accepted Answer

Ixodes scapularis ticks

Answer

Anopheles

Answer

Louse

Answer

Rat flea

Question 5

A red soft to firm swelling on the sternum shows proliferation of endothelial cells forming vascular channels on biopsy. What is the most likely diagnosis?

Accepted Answer

Hemangioma

Answer

Osteochondroma

Answer

Osteoid osteoma

Answer

Paget disease

Question 6

Positive periodic acid-Schiff (PAS) macrophages are seen in which of the following conditions?

Accepted Answer

Whipple's disease

Answer

Crohn's disease

Answer

HIV/AIDS

Answer

Celiac disease

Question 7

A 1-year-old child weighing 6 kg is suffering from acute gastroenteritis with signs of sunken eyes and skin pinch returning to normal very rapidly. What will be your management?

Accepted Answer

RL infusion 180 ml in the first hour followed by 270 ml in the next 5 hours

Answer

RL infusion 120 ml in the first hour followed by 360 ml in the next 5 hours

Answer

RL infusion 180 ml in the first hour followed by 480 ml in the next 5 hours

Answer

RL infusion 240 ml in the first hour followed by 360 ml in the next 5 hours

Question 8

Anaerobes are resistant intrinsically against which of the following?

Accepted Answer

Aminoglycosides

Answer

Azithromycin

Answer

Metronidazole

Answer

Beta lactam antibiotics

Question 9

What is the current preferred term for the condition previously known as mental retardation?

Accepted Answer

Intellectual disability

Answer

Feeble Mindedness

Answer

Madness

Answer

Mentally unstable

Question 10

Which of the following statements about the management of haematomas is NOT correct?

Accepted Answer

Haematoma must be operated.

Answer

Some haematomas require surgical intervention.

Answer

GCS assessment is helpful in prognosis.

Answer

CT scan is the investigation of choice for acute haemorrhage.

NEET-PG 2018

Biochemistry

Internal Medicine

Microbiology

Pathology

Pediatrics

Pharmacology

Psychiatry

Surgery