NEET-PG 2013 Practice Questions

Q: Which of the following is not an acute phase reactant?

Endothelin. ***Endothelin*** - Endothelin is a **vasoconstrictive peptide** primarily involved in regulating **blood vessel tone** and blood pressure. - While it plays a role in processes like inflammation and tissue repair, it is not synthesized or regulated in the same rapid, systemic manner as a classic acute phase reactant. *C-reactive protein* - **C-reactive protein (CRP)** is a rapidly responding acute phase reactant produced by the liver in response to **inflammation**, infection, and tissue injury. - Its levels can rise dramatically within hours of an inflammatory stimulus and are used as a marker for disease activity. *Haptoglobin* - **Haptoglobin** is an acute phase reactant that binds to free **hemoglobin** released from red blood cells during hemolysis, preventing oxidative damage. - Its levels typically increase during acute inflammation or infection, although it can also decrease with severe hemolysis. *Fibrinogen* - **Fibrinogen** is a critical acute phase protein involved in the **coagulation cascade** and wound healing. - Its concentration increases significantly during acute inflammation, contributing to the elevated **erythrocyte sedimentation rate (ESR)**.

Q: Which of the following viral diseases is least commonly reported in India?

Lassa fever. ***Lassa fever*** - **Lassa fever** is endemic to West Africa, with the **multimammate rat** being its primary reservoir. - Cases of Lassa fever are **extremely rare** in India, primarily limited to travel-related instances due to the geographical distribution of the disease and its vector. *Japanese B encephalitis* - **Japanese B encephalitis (JBE)** is a significant public health concern in India, particularly in endemic regions. - It is a mosquito-borne viral disease, and **vaccination programs** are ongoing to control its spread. *KFD* - **Kyasanur Forest Disease (KFD)** is an endemic viral hemorrhagic fever primarily found in the **Karnataka state of India**. - It is transmitted by **ticks**, making it a regionally significant but recognized viral disease within India. *Dengue* - **Dengue** is one of the most commonly reported and widespread viral diseases in India. - It is a **mosquito-borne** illness with frequent outbreaks occurring across various parts of the country.

Q: What does the hookworm primarily feed on?

Blood from intestinal mucosa. ***Blood from intestinal mucosa*** - Hookworms attach to the **intestinal wall** and ingest host blood, leading to blood loss and potential **anemia**. - They produce **anticoagulants** to facilitate continuous feeding from the mucosal capillaries. *Plasma proteins* - While plasma contains proteins, hookworms primarily feed directly on **whole blood**, not just isolated plasma proteins. - Feeding mainly on plasma proteins would not explain the significant **iron-deficiency anemia** associated with hookworm infection. *Lymphatic fluid* - Hookworms reside in the **small intestine** and do not typically feed on lymphatic fluid. - Other parasites, like **filarial worms**, are known to inhabit and obstruct the lymphatic system. *Interstitial fluid* - Interstitial fluid is found in the spaces between cells; hookworms feed from the **vascular supply** within the intestinal mucosa. - Feeding on interstitial fluid would not cause the characteristic **blood loss** seen in hookworm infections.

Q: Cylindrical helminths are -

Roundworms. ***Roundworms*** - **Roundworms**, also known as **nematodes**, are characterized by their **cylindrical body shape**. - Their unsegmented, tapered bodies distinguish them from flatworms like tapeworms and flukes. *Tapeworms* - **Tapeworms**, or **cestodes**, have **flat, ribbon-like bodies** segmented into proglottids. - They are not cylindrical but rather dorsoventrally flattened. *Flukes* - **Flukes**, or **trematodes**, have **flat, leaf-shaped bodies**, which are not cylindrical. - Their morphology includes suckers for attachment and they are not segmented. *Hookworms* - **Hookworms** are a type of **roundworm** (nematode), which means they are cylindrical. However, "Roundworms" is a broader and more accurate classification for the general term "cylindrical helminths." - While hookworms are indeed cylindrical, the option "Roundworms" encompasses all such cylindrical helminths, making it a more general and appropriate answer.

Q: Which of the following is the only ovoviviparous parasite among the options provided?

Strongyloides. ***Strongyloides*** - *Strongyloides stercoralis* stands out as the only **ovoviviparous** parasite among the options, meaning that its eggs hatch while still inside the uterus of the female worm. - The female worm lays **larvated eggs** that quickly hatch into **rhabditiform larvae** in the intestine or intestinal wall, which are then passed in the feces. *Ascaris* - *Ascaris lumbricoides* is **oviparous**, laying **unembryonated eggs** that are passed in the feces and require a period of maturation in the soil to become infective. - The eggs are robust and can survive for long periods in the environment before they are ingested. *Enterobius* - *Enterobius vermicularis* (pinworm) is also **oviparous**, with the female worm migrating to the perianal region to lay **embryonated eggs** on the skin. - These eggs are immediately infective to humans upon ingestion. *Ancylostome* - Ancylostomes (hookworms) are **oviparous** and lay **thin-shelled eggs** that are passed in the feces and hatch into rhabditiform larvae in the soil. - These larvae then develop into infective **filariform larvae** that penetrate the skin.

Q: Macrophage tropic strains of HIV use which co-receptor?

CCR5. ***CCR5*** - **Macrophage-tropic** HIV strains, also known as **R5 strains**, primarily use the **CCR5 co-receptor** to enter target cells. - These strains are typically involved in the **initial infection** and transmission of HIV. - CCR5-tropic viruses are usually the **predominant strains transmitted** during sexual transmission. *CXCR4* - **T-cell-tropic** HIV strains, or **X4 strains**, preferentially utilize the **CXCR4 co-receptor** for cell entry. - These strains are associated with a **more rapid decline in CD4+ T-cell counts** during later stages of HIV infection. - Emergence of X4 strains is linked to **disease progression**. *CCR3* - While a chemokine receptor, **CCR3** is not a primary co-receptor used by common HIV strains for entry into macrophages or T cells. - CCR3 is primarily involved in **eosinophil chemotaxis** and allergic responses. *CCR2* - **CCR2** is another chemokine receptor but is **not a major co-receptor** for HIV entry. - While some laboratory-adapted strains may show minor usage, it is not clinically significant for macrophage-tropic HIV strains.

Q: Consumption of uncooked pork is likely to cause which of the following helminthic disease -

Taenia solium. ***Taenia solium*** - Infection with **_Taenia solium_** (pork tapeworm) occurs by consuming raw or undercooked **pork** containing **cysticerci** (larval cysts). - This can lead to **taeniasis** (intestinal tapeworm infection) and, if humans ingest the eggs, **cysticercosis**, a more severe disease involving larval cysts in tissues like the brain. *Taenia saginata* - **_Taenia saginata_** (beef tapeworm) is acquired by eating raw or undercooked **beef** containing larval cysts, not pork. - While it causes gastrointestinal symptoms, it does not typically lead to systemic cysticercosis in humans. *Trichuris trichiura* - **_Trichuris trichiura_** (whipworm) infection is caused by ingesting **embryonated eggs** from contaminated soil, typically associated with poor sanitation. - It is not transmitted through the consumption of undercooked meat. *None of the options* - This option is incorrect because **_Taenia solium_** is definitively associated with the consumption of uncooked pork.

Q: Trophozoites in stool are characteristically seen in which of the following conditions?

**Note:** This question has significant issues. Trophozoites in stool are characteristically seen in **protozoal infections** such as *Entamoeba histolytica* (amoebiasis), *Giardia lamblia*, or *Balantidium coli* [1][2] - none of which are listed as options. ***None of the given options is medically accurate*** for characteristic trophozoites in stool. However, if forced to choose from these options: *Ascariasis* - **Ascariasis** is caused by the nematode *Ascaris lumbricoides* - Diagnosis is by identifying **ova (eggs)** in stool, not trophozoites - Trophozoites are protozoal forms, not associated with helminthic infections [2] *Strongyloidiasis* - Caused by *Strongyloides stercoralis* (nematode) - Typically diagnosed by finding **rhabditiform or filariform larvae** in stool - Not characterized by trophozoites in routine stool examination *Eosinophilic gastroenteritis* - Inflammatory condition with **eosinophilic infiltration** of GI tract - Not a parasitic infection - No trophozoites present - diagnosis is by endoscopic biopsy showing eosinophils *Allergic colitis* - Inflammatory condition related to **food allergies** (common in infants) - Presents with blood and mucus in stool with eosinophilia - Not an infectious process - no trophozoites present **Clinical Pearl:** Trophozoites (motile feeding stage of protozoa) in stool are diagnostic of **acute intestinal protozoal infections** like amoebiasis or giardiasis, where they must be identified in fresh, warm stool samples as they rapidly deteriorate [1][2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 364-365. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 801-802.

Q: Which drug is used for sympathectomy in experimental animals?

Guanethidine. ***Guanethidine*** - **Guanethidine** is a potent **adrenergic neuron blocking drug** that is taken up by noradrenergic neurons and prevents the release of norepinephrine, leading to a chemical sympathectomy. - In experimental animal models, it is used to induce a **pharmacological sympathectomy** to study the effects of sympathetic nervous system blockade on various physiological processes. *Atropine* - **Atropine** is a **muscarinic acetylcholine receptor antagonist** that blocks the effects of acetylcholine at parasympathetic postganglionic terminals. - It is primarily used to block **parasympathetic responses**, not sympathetic ones, and therefore would not induce a sympathectomy. *Diazoxide* - **Diazoxide** is a direct **arteriolar vasodilator** that works by opening potassium channels in vascular smooth muscle. - It is used to quickly reduce blood pressure in **hypertensive emergencies** and for treating hypoglycemia due to insulin oversecretion, and does not cause sympathectomy. *Thebaine* - **Thebaine** is an **opioid alkaloid** found in opium, structurally similar to morphine and codeine, but with primarily stimulatory rather than depressant effects. - It acts as a **convulsant** and is used as a precursor in the synthesis of other opioids, but has no role in causing sympathectomy.

Q: In which of the following conditions is Verapamil not typically used?

Ventricular tachycardia. ***Ventricular tachycardia*** - Verapamil, a **non-dihydropyridine calcium channel blocker**, can worsen hemodynamics in patients with **ventricular tachycardia (VT)** by causing profound hypotension or precipitating cardiac arrest. - VT often requires prompt treatment with **antiarrhythmics like amiodarone** or **electrical cardioversion**, as it can be life-threatening. - Verapamil is **contraindicated in VT** due to its negative inotropic effects and risk of hemodynamic collapse. *Angina pectoris* - Verapamil is effectively used to treat angina pectoris by **decreasing myocardial oxygen demand** through negative chronotropic and inotropic effects, and by causing **coronary vasodilation**, improving blood flow. - Its effects help to reduce the frequency and severity of anginal episodes, particularly in **stable angina**. *Atrial fibrillation* - Verapamil is commonly used for **rate control in atrial fibrillation** by **slowing conduction through the AV node**, which decreases the ventricular response rate. - It helps to manage symptoms and prevent complications related to rapid heart rates in this arrhythmia. *Hypertension* - Verapamil is used in the treatment of **hypertension** through its vasodilatory effects and reduction in peripheral vascular resistance. - It is particularly useful in patients who cannot tolerate other antihypertensive agents or as part of combination therapy.

Question 1

Which of the following is not an acute phase reactant?

Accepted Answer

Endothelin

Answer

C-reactive protein

Answer

Haptoglobin

Answer

Fibrinogen

Question 2

Which of the following viral diseases is least commonly reported in India?

Accepted Answer

Lassa fever

Answer

Japanese B encephalitis

Answer

KFD

Answer

Dengue

Question 3

What does the hookworm primarily feed on?

Accepted Answer

Blood from intestinal mucosa

Answer

Plasma proteins

Answer

Lymphatic fluid

Answer

Interstitial fluid

Question 4

Cylindrical helminths are -

Accepted Answer

Roundworms

Answer

Tapeworms

Answer

Flukes

Answer

Hookworms

Question 5

Which of the following is the only ovoviviparous parasite among the options provided?

Accepted Answer

Strongyloides

Answer

Ascaris

Answer

Enterobius

Answer

Ancylostoma

Question 6

Macrophage tropic strains of HIV use which co-receptor?

Accepted Answer

CCR5

Answer

CXCR4

Answer

CCR3

Answer

CCR2

Question 7

Consumption of uncooked pork is likely to cause which of the following helminthic disease -

Accepted Answer

Taenia solium

Answer

Taenia saginata

Answer

Trichuris trichiura

Answer

None of the options

Question 8

Trophozoites in stool are characteristically seen in which of the following conditions?

Answer

Ascariasis

Answer

Strongyloidiasis

Answer

Allergic colitis

Answer

Eosinophilic gastroenteritis

Question 9

Which drug is used for sympathectomy in experimental animals?

Accepted Answer

Guanethidine

Answer

Atropine

Answer

Diazoxide

Answer

Thebaine

Question 10

In which of the following conditions is Verapamil not typically used?

Accepted Answer

Ventricular tachycardia

Answer

Angina pectoris

Answer

Atrial fibrillation

Answer

Hypertension

NEET-PG 2013

Biochemistry

Community Medicine

Microbiology

Pathology

Pharmacology