NEET-PG 2013 Practice Questions

Q: Which one of the following is the most common CNS tumor associated with type I neurofibromatosis?

Optic nerve glioma. ***Optic nerve glioma*** - **Optic nerve gliomas** are the most frequently encountered central nervous system tumors in patients with **Type 1 neurofibromatosis (NF1)**, occurring in about 15% of individuals. - They are typically low-grade **astrocytomas** and can cause vision loss and proptosis depending on their size and location. *Meningioma* - While more common in **Type 2 neurofibromatosis (NF2)**, meningiomas can occur in NF1, but are not the most common CNS tumor. - Meningiomas are tumors that arise from the **meninges**, the membranes surrounding the brain and spinal cord. *Acoustic schwannoma* - **Bilateral acoustic schwannomas (vestibular schwannomas)** are the hallmark feature of **Type 2 neurofibromatosis (NF2)**, not NF1 [1]. - These tumors arise from the Schwann cells of the **vestibulocochlear nerve** and can cause hearing loss and balance issues [1]. *Low grade astrocytoma* - While optic nerve gliomas are a type of low-grade astrocytoma, this option is too general; **optic nerve glioma** is the specific and most common presentation in NF1. - Other forms of low-grade astrocytomas can occur in NF1 but are not as universally characteristic as optic nerve gliomas.

Q: Autoimmune thyroiditis is associated with all except which of the following?

Psoriasis. ***Psoriasis*** - Psoriasis is generally not associated with **autoimmune thyroiditis**, which is more commonly linked to other autoimmune disorders [1]. - Autoimmune thyroiditis does not typically result in the **skin changes** seen in psoriasis, distinguishing them clinically. *Sly* - Sly syndrome, while a genetic disorder, is not directly connected to **autoimmune thyroiditis**. - Conditions like Sly syndrome are metabolic and do not involve the autoimmune pathways typically seen in thyroiditis. *Myasthenia gravis* - Myasthenia gravis is an **autoimmune neuromuscular disorder** that can occur concurrently with thyroid diseases, particularly **thyroiditis** [1]. - Both conditions arise from **autoimmune processes**, making their association plausible [1]. *DM* - Diabetes Mellitus (DM), particularly Type 1, is often linked with other autoimmune diseases, including **autoimmune thyroiditis** [2]. - They share a common **autoimmune pathway**, making them more likely to co-occur than psoriasis [2].

Q: Anemia with reticulocytosis is seen in -

Hemolysis. ***Hemolysis*** - Reticulocytosis indicates a compensatory response to anemia, often occurring in hemolytic processes where the **bone marrow increases red blood cell production** in response to red blood cell destruction. - Conditions like **sickle cell disease** or **autoimmune hemolytic anemia** lead to hemolysis, further confirming increased reticulocyte count. *Iron deficiency anemia* - Typically presents with a **low reticulocyte count** as the bone marrow does not have sufficient iron to produce new red blood cells. - This condition is characterized by **microcytic, hypochromic** red blood cells due to inadequate iron stores. *Vitamin B12 deficiency* - Often results in a **macrocytic anemia** with a variable reticulocyte count; however, reticulocytosis is generally not seen initially. - This deficiency affects DNA synthesis, leading to ineffective erythropoiesis and the presence of **megaloblastic changes**. *Aplastic anemia* - Characterized by a **decrease in all types of blood cells** (pancytopenia) and typically has a **low reticulocyte count** due to bone marrow failure. - There is insufficient production of red blood cells, hence **reticulocytosis is not observed**.

Q: Flexner-Wintersteiner rosette is seen in-

Retinoblastoma. ***Retinoblastoma*** - Flexner-Wintersteiner rosettes are **characteristic histological features** seen in retinoblastoma, indicating retinal differentiation [1]. - These rosettes reflect the **presence of photoreceptor-like structures**, which are specific to this type of tumor [1]. *Hepatoblastoma* - Histologically, hepatoblastoma shows **primitive epithelial cells** and **mixed patterns**, not Flexner-Wintersteiner rosettes. - It is primarily associated with **liver** and does not present with retinal differentiation. *Nephroblastoma* - Nephroblastoma, or Wilms tumor, typically exhibits **triphasic histology** (epithelial, stromal, and blastemal components) without rosette formation. - It primarily affects the **kidney** and does not involve the retina. *Neuroblastoma* - Neuroblastoma is characterized by **small round blue cells** and **neuroid differentiation** but lacks Flexner-Wintersteiner rosettes. - This tumor usually arises in the **adrenal glands** or sympathetic nervous system, not in retinal tissue. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Eye, p. 1342.

Q: Which antiglaucomatous drug is known to cause spasm of accommodation?

Pilocarpine. ***Pilocarpine*** - **Pilocarpine** is a **direct-acting muscarinic agonist** that contracts the **ciliary muscle**. - Contraction of the ciliary muscle leads to **accommodation spasm** and a forward movement of the **iris-lens diaphragm**, which also helps to open the **trabecular meshwork**, facilitating aqueous outflow. *Timolol* - **Timolol** is a **beta-blocker** that reduces aqueous humor production by blocking beta-adrenergic receptors on the ciliary epithelium. - It does not directly affect the **ciliary muscle** or cause accommodation spasm. *Dorazolamide* - **Dorzolamide** is a **carbonic anhydrase inhibitor** that reduces aqueous humor production. - Its mechanism of action does not involve the ciliary body's mechanical action and therefore does not cause **accommodation spasm**. *Latanoprost* - **Latanoprost** is a **prostaglandin analog** that increases uveoscleral outflow of aqueous humor. - It does not directly affect the ciliary muscle's contraction or cause **accommodation spasm**.

Q: Muscarinic cholinergic receptors are seen at all sites, except?

Neuromuscular junction. ***Neuromuscular junction*** - The **neuromuscular junction** primarily contains **nicotinic cholinergic receptors**, not muscarinic receptors. - Activation of these nicotinic receptors by acetylcholine causes muscle contraction. *Stomach* - The stomach contains **muscarinic M3 receptors** which mediate gastric acid secretion and smooth muscle contraction. - Activation by acetylcholine via the vagus nerve promotes digestion. *CNS* - The **central nervous system** has various subtypes of **muscarinic receptors (M1-M5)** distributed throughout, playing roles in learning, memory, and motor control. - These receptors modulate neuronal excitability and neurotransmitter release. *Glands* - Most exocrine glands (e.g., salivary, lacrimal, sweat glands) are richly supplied with **muscarinic receptors**, primarily **M3**. - Activation leads to increased glandular secretion.

Q: Which of the following is classified as a Type E adverse reaction?

Rebound effect due to drug withdrawal. ***Rebound effect due to drug withdrawal*** - Type E adverse reactions are related to **end-of-treatment effects**, specifically withdrawal phenomena. - The **rebound effect** after drug cessation, such as worsened angina after stopping beta-blockers, is a classic example of a Type E reaction. *Toxicity* - This is a general term for adverse effects from excessive drug doses and is **not a specific type** in the ABCDEF classification. - Dose-dependent toxic effects typically align with **Type A** (augmented) reactions, which are predictable and related to the drug's pharmacology. *Augmented effect* - An **augmented effect** is classified as a Type A adverse drug reaction, meaning it is **dose-dependent**, predictable from the drug's known pharmacology, and common. - Examples include bleeding with anticoagulants or hypotension with antihypertensives. *Teratogenesis* - **Teratogenesis** refers to drug-induced fetal malformations and is categorized as a **Type D** (delayed) adverse drug reaction. - These effects are often severe, occur after prolonged exposure, and are rare.

Q: Which of the following statements is true regarding omalizumab?

All of the options. ***All of the options*** is correct because each statement is true: **Anti-IgE** - Omalizumab is a **humanized monoclonal antibody** that specifically targets and binds to **free IgE** in the circulation - By binding free IgE, it prevents IgE from attaching to **high-affinity receptors** on mast cells and basophils - This reduces the allergic cascade and prevents release of inflammatory mediators **Given subcutaneously** - Omalizumab is administered via **subcutaneous injection** only - Dosing is typically every **2 to 4 weeks** based on patient's body weight and baseline IgE levels - Not available in oral or intravenous formulations for asthma treatment **Used as add-on therapy in moderate to severe asthma prophylaxis** - FDA approved as **add-on maintenance treatment** for patients aged ≥6 years with **moderate to severe persistent allergic asthma** - Indicated when asthma is **inadequately controlled** with inhaled corticosteroids - Reduces frequency of asthma exacerbations and improves asthma control - Also approved for chronic spontaneous urticaria All three statements accurately describe omalizumab's mechanism, administration route, and clinical indication, making **"All of the options"** the correct answer.

Q: Which of the following drugs is known to have low first pass metabolism?

Theophylline. ***Theophylline*** - **Theophylline** exhibits **low first-pass metabolism**, meaning a significant portion of the orally administered drug reaches systemic circulation unchanged. - This characteristic contributes to its relatively **high bioavailability** when given orally. *Lidocaine* - **Lidocaine** undergoes extensive **first-pass metabolism** in the liver, leading to very low oral bioavailability. - Due to this, it is typically administered **parenterally** (e.g., intravenously or topically) to achieve therapeutic concentrations. *Propranolol* - **Propranolol** is known for its significant **first-pass metabolism**, which results in a much lower bioavailability after oral administration compared to intravenous. - This extensive metabolism necessitates higher oral doses to achieve the same therapeutic effect as parenteral administration. *Morphine* - **Morphine** also undergoes substantial **first-pass metabolism** in the liver, where it is primarily glucuronidated. - This leads to a lower oral bioavailability compared to other routes of administration and contributes to a higher oral dose requirement.

Q: Which of the following develop first during dependence of a substance ?

Psychological dependence. ***Psychological dependence*** - **Psychological dependence** often develops first, characterized by an emotional need for the substance to experience pleasure or avoid discomfort. - This involves a strong **craving** and compulsive drug-seeking behavior despite negative consequences, driven by the substance's effect on brain reward pathways. *Tolerance* - **Tolerance** means that increasing doses of the substance are required to achieve the same effect previously achieved with lower doses. - While it often develops early in substance use, the initial "need" to use the substance is often psychological before physiological adaptations occur. *Physical dependence* - **Physical dependence** describes the body's physiological adaptation to the substance, leading to withdrawal symptoms if use is stopped or reduced. - It typically develops after consistent, prolonged use and is usually preceded by psychological dependence and often tolerance. *Withdrawal symptoms* - **Withdrawal symptoms** are the physiological and psychological signs that occur when a dependent person stops or drastically reduces their substance intake. - These are a direct manifestation of physical dependence and thus develop once physical dependence has been established.

Question 1

Which one of the following is the most common CNS tumor associated with type I neurofibromatosis?

Accepted Answer

Optic nerve glioma

Answer

Meningioma

Answer

Acoustic schwannoma

Answer

Low grade astrocytoma

Question 2

Autoimmune thyroiditis is associated with all except which of the following?

Accepted Answer

Psoriasis

Answer

DM

Answer

Myasthenia gravis

Answer

SLE

Question 3

Anemia with reticulocytosis is seen in -

Accepted Answer

Hemolysis

Answer

Iron deficiency anemia

Answer

Vitamin B12 deficiency

Answer

Aplastic anemia

Question 4

Flexner-Wintersteiner rosette is seen in-

Accepted Answer

Retinoblastoma

Answer

Hepatoblastoma

Answer

Nephroblastoma

Answer

Neuroblastoma

Question 5

Which antiglaucomatous drug is known to cause spasm of accommodation?

Accepted Answer

Pilocarpine

Answer

Timolol

Answer

Dorzolamide

Answer

Latanoprost

Question 6

Muscarinic cholinergic receptors are seen at all sites, except?

Accepted Answer

Neuromuscular junction

Answer

Stomach

Answer

CNS

Answer

Glands

Question 7

Which of the following is classified as a Type E adverse reaction?

Accepted Answer

Rebound effect due to drug withdrawal

Answer

Toxicity

Answer

Augmented effect

Answer

Teratogenesis

Question 8

Which of the following statements is true regarding omalizumab?

Accepted Answer

All of the options

Answer

Anti-IgE

Answer

Given subcutaneously

Answer

Used as add-on therapy in moderate to severe asthma prophylaxis

Question 9

Which of the following drugs is known to have low first pass metabolism?

Accepted Answer

Theophylline

Answer

Lidocaine

Answer

Propranolol

Answer

Morphine

Question 10

Which of the following develop first during dependence of a substance ?

Accepted Answer

Psychological dependence

Answer

Tolerance

Answer

Physical dependence

Answer

Withdrawal symptoms

NEET-PG 2013

Internal Medicine

Pathology

Pharmacology

Psychiatry