NEET-PG 2012 Practice Questions

Q: What condition is caused by the intake of exogenous steroids?

Cushing's syndrome. ***Cushing's syndrome*** - **Exogenous steroid intake** is the most common cause of Cushing's syndrome, leading to symptoms associated with **excess cortisol** [1]. - This occurs because the steroids mimic the effects of **cortisol**, suppressing the body's natural production and leading to its characteristic signs and symptoms [2]. *Addison's disease* - This condition is characterized by **adrenal insufficiency**, meaning the adrenal glands produce too little **cortisol** and often **aldosterone**. - It is typically caused by autoimmune destruction of the adrenal glands, not by exogenous steroid intake. *Pheochromocytoma* - This is a rare tumor of the **adrenal medulla** that causes the overproduction of **catecholamines** (epinephrine and norepinephrine). - Symptoms include sudden, severe episodes of hypertension, palpitations, and sweating, unrelated to steroid intake. *Conn's syndrome* - Also known as **primary hyperaldosteronism**, this condition involves the overproduction of **aldosterone** by the adrenal glands. - It typically results in hypertension and hypokalemia and is not directly caused by exogenous steroid administration.

Q: What is the most common primary malignancy of the fallopian tube?

Serous carcinoma. ***Serous carcinoma*** - **Serous carcinoma** is the most common type of **primary** fallopian tube malignancy, accounting for approximately **90%** of primary tumors. - It often shares molecular and morphological similarities with **high-grade serous ovarian carcinoma** and **primary peritoneal cancer**. - Note: While primary fallopian tube cancer is rare (0.14-1.8% of gynecologic malignancies), metastatic disease to the fallopian tube is more common, typically from **ovarian or endometrial** primaries. *Squamous cell carcinoma* - **Squamous cell carcinoma** is exceedingly rare in the fallopian tube, as the tubal lining is composed of **ciliated and secretory columnar epithelium**, not squamous epithelium. - When present, it usually represents **metastatic spread** from cervical or other primary sites. *Teratoma* - **Teratomas** are germ cell tumors typically found in the **ovaries**, composed of tissues from multiple germ layers. - Primary teratomas of the fallopian tube are **extraordinarily rare** and not the most common primary malignancy. *Choriocarcinoma* - **Choriocarcinoma** is a highly malignant **gestational trophoblastic neoplasm** usually associated with pregnancy complications. - It primarily occurs in the **uterus**, and primary fallopian tube choriocarcinoma is **exceptionally uncommon**.

Q: Which of the following germ cell tumors is benign?

Dermoid cyst. ***Seminoma*** - Seminomas are well-known malignant **germ cell tumors**, primarily affecting young males [2]. - They are associated with elevated **human chorionic gonadotropin (hCG)** and can spread to lymph nodes [3]. *Leydig cell tumor* - These tumors are usually **benign** and arise from Leydig cells in the testes. - While they can produce **testosterone**, they do not typically exhibit malignancy. *Sertoli cell tumor* - Sertoli cell tumors are also generally **benign** and arise from Sertoli cells in the testes. - They lack the malignant behavior seen in seminomas and have a low rate of metastasis [1]. *Dermoid cyst* - Dermoid cysts are **benign** mature teratomas, commonly found in the ovaries or testicles. - They can contain different tissue types (like hair, fat, and teeth) but are not malignant. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 512-513. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 979-980. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 980-982.

Q: Ewing's sarcoma arises from which type of cells?

Primitive neuroectodermal cells. ***Primitive neuroectodermal cells*** - **Ewing's sarcoma** is a malignant small round blue cell tumor largely believed to arise from **primitive neuroectodermal cells**. - This cellular origin explains why it's often grouped under the term **PNET (Primitive Neuroectodermal Tumor)**. *G cells* - **G cells** are specialized **enteroendocrine cells** found in the stomach and duodenum that secrete **gastrin**. - They are involved in regulating gastric acid secretion and have no association with Ewing's sarcoma. *Totipotent cells* - **Totipotent cells** have the ability to differentiate into **any type of cell**, including embryonic and extraembryonic tissues. - While all cancers originate from cellular changes, Ewing's sarcoma originates from a more specific, committed cell lineage, not totipotent stem cells. *Neurons* - **Neurons** are the basic functional units of the nervous system, responsible for transmitting electrical and chemical signals. - While Ewing's sarcoma has neuroectodermal characteristics, it does not arise from fully differentiated neurons but rather from more **primitive precursors**.

Q: Perivascular lymphocytes & microglial nodules are seen in -

HIV encephalitis. ***HIV encephalitis*** - **Perivascular lymphocytes** and **microglial nodules** are the characteristic histopathological hallmarks of **HIV encephalitis (HIV-associated dementia complex)** [1][2]. - Microglial nodules are formed by activated microglia and macrophages, often accompanied by **multinucleated giant cells** (the classic triad) [2]. - These features reflect chronic CNS inflammation and neuronal damage caused by HIV infection. *CMV meningitis* - Cytomegalovirus (CMV) infection in immunocompromised patients causes meningoencephalitis with characteristic **intranuclear ("owl's eye") inclusion bodies** and necrotizing inflammation. - The histological pattern differs from the microglial nodules and perivascular lymphocytes seen in HIV encephalitis. *Bacterial meningitis* - Characterized by prominent **neutrophilic infiltrate** in the subarachnoid space, fibrinopurulent exudate, and potential vasculitis. - Acute bacterial meningitis does not show the lymphocytic and microglial nodular pattern characteristic of viral encephalitis. *Multiple sclerosis* - An autoimmune demyelinating disease with **perivenular demyelinating plaques** containing lymphocytes and macrophages. - While perivascular inflammation occurs, **microglial nodules** are not a characteristic feature; instead, MS shows demyelination with reactive gliosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, p. 1278. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 711-712.

Q: What is a key difference between fosphenytoin and phenytoin?

Can be mixed with saline. **Can be mixed with saline** - **Fosphenytoin** is a water-soluble prodrug that is converted to phenytoin in the body; its solubility allows it to be **mixed with saline** solutions for intravenous administration, minimizing the risk of precipitation. - Unlike phenytoin, fosphenytoin's formulation avoids the need for propylene glycol, which is associated with adverse cardiovascular effects and makes phenytoin incompatible with saline. *Can be used in absence seizures* - Neither **fosphenytoin nor phenytoin** is effective for treating **absence seizures**, and they can sometimes worsen them. - **Ethosuximide** or **valproic acid** are the drugs of choice for absence seizures. *Can be given orally* - While **phenytoin** is commonly available in oral forms (capsules, chewable tablets, suspension), **fosphenytoin** is primarily designed for **parenteral administration** (intravenous or intramuscular). - Fosphenytoin is a prodrug that is rapidly converted to phenytoin *in vivo*, but it is not typically available or indicated for direct oral administration. *It is the drug of choice for myoclonic seizures* - Neither **fosphenytoin nor phenytoin** is the drug of choice for **myoclonic seizures**; they can exacerbate this type of seizure. - **Valproic acid** and **levetiracetam** are preferred treatments for myoclonic seizures due to their broader spectrum of activity.

Q: Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?

Beta-2 receptor stimulation. ***Beta-2 receptor stimulation*** - Theophylline is a **non-selective phosphodiesterase inhibitor** and an **adenosine receptor antagonist**, but it does not directly stimulate beta-2 receptors. - **Beta-2 receptor agonists** like salbutamol or formoterol are the medications that work by stimulating these receptors to cause bronchodilation. *Phosphodiesterase inhibition* - Theophylline inhibits **phosphodiesterase enzymes**, leading to an increase in intracellular **cAMP** levels. - This increase in **cAMP** promotes bronchodilation by relaxing airway smooth muscle. *Adenosine receptor antagonism* - Theophylline acts as an antagonist at **adenosine receptors**, particularly A1 and A2B. - Antagonism of adenosine receptors can reduce bronchoconstriction and inflammatory mediator release, contributing to its anti-asthmatic effects. *Increased histone deacetylation* - Theophylline, particularly at lower concentrations, increases the activity of **histone deacetylase (HDAC)**. - This action helps to **repress inflammatory gene expression**, which is a unique anti-inflammatory mechanism separate from its bronchodilatory effects.

Q: Omalizumab is primarily used in the treatment of which condition?

Asthma. ***Asthma*** - **Omalizumab** is a **monoclonal antibody** that targets and binds to **immunoglobulin E (IgE)**, preventing it from binding to mast cells and basophils. - By reducing free IgE, omalizumab helps to prevent the release of inflammatory mediators, thereby **reducing allergic reactions and asthma symptoms**, particularly in patients with severe persistent allergic asthma. *Breast carcinoma* - **Omalizumab** is not indicated for the treatment of **breast carcinoma**; treatments for breast cancer typically involve chemotherapy, radiation, surgery, and targeted therapies specific to cancer cells. - Targeted therapies for breast cancer often focus on hormone receptors (e.g., **estrogen receptor**) or growth factor receptors (e.g., **HER2**), not IgE. *Rheumatoid arthritis* - **Omalizumab** is not used for **rheumatoid arthritis (RA)**; RA is an autoimmune disease primarily involving **T-cells and cytokines** like **TNF-alpha** and **IL-6**. - Treatment for RA typically includes **DMARDs** (disease-modifying antirheumatic drugs) and **biological agents** that target specific inflammatory pathways (e.g., **adalimumab**, **etanercept**). *Chronic obstructive pulmonary disease (COPD)* - **Omalizumab** is not indicated for **COPD**, which is primarily characterized by chronic inflammation of the airways and **emphysema**, largely caused by smoking. - COPD management focuses on bronchodilators, corticosteroids, and oxygen therapy, with no role for IgE-targeting therapy.

Q: Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?

Venlafaxine. ***Venlafaxine*** - **Venlafaxine** is a commonly used antidepressant that inhibits the reuptake of both **serotonin** and **norepinephrine**, making it an SNRI. - Its dual mechanism of action can be effective for a broad range of depressive and anxiety disorders. *Fluoxetine* - **Fluoxetine** is a **selective serotonin reuptake inhibitor (SSRI)**, primarily affecting serotonin levels in the brain. - It does not significantly inhibit norepinephrine reuptake and, thus, is not classified as an SNRI. *Sertraline* - **Sertraline** is another widely prescribed antidepressant that is also a **selective serotonin reuptake inhibitor (SSRI)**. - It works mainly by increasing serotonin availability in the synaptic cleft. *Aripiprazole* - **Aripiprazole** is an **atypical antipsychotic** medication, often used as an adjunct therapy for depression, but its primary mechanism is partial agonism at dopamine D2 and serotonin 5-HT1A receptors, and antagonism at serotonin 5-HT2A receptors. - It is not classified as a selective serotonin and norepinephrine reuptake inhibitor.

Q: Which steroid has the maximum mineralocorticoid activity?

Fludrocortisone. ***Fludrocortisone*** - **Fludrocortisone** is a synthetic corticosteroid specifically designed to have potent **mineralocorticoid activity**, with significant sodium-retaining properties. - Its high affinity for **mineralocorticoid receptors** distinguishes it from other steroids and makes it effective in treating conditions like **Addison's disease** and **postural orthostatic tachycardia syndrome (POTS)** due to its ability to retain sodium and water. *DOCA (Deoxycorticosterone acetate)* - While **DOCA** does possess significant **mineralocorticoid activity** and was historically used for this purpose, **fludrocortisone** is generally considered to have a stronger and more sustained effect in clinical practice. - **DOCA's** mineralocorticoid potency is substantial but slightly less than that of **fludrocortisone** when compared on a weight basis for equivalent sodium retention. *Prednisolone* - **Prednisolone** is primarily a **glucocorticoid** with potent anti-inflammatory and immunosuppressive effects. - It has minimal to negligible **mineralocorticoid activity** and is not used for salt retention purposes. *Triamcinolone* - **Triamcinolone** is a potent **glucocorticoid** with a long duration of action and is known for its strong anti-inflammatory properties. - It has virtually no **mineralocorticoid activity**, making it unsuitable for conditions requiring sodium retention.

Question 1

What condition is caused by the intake of exogenous steroids?

Accepted Answer

Cushing's syndrome

Answer

Addison's disease

Answer

Pheochromocytoma

Answer

Conn's syndrome

Question 2

What is the most common primary malignancy of the fallopian tube?

Accepted Answer

Serous carcinoma

Answer

Squamous cell carcinoma

Answer

Teratoma

Answer

Choriocarcinoma

Question 3

Which of the following germ cell tumors is benign?

Accepted Answer

Dermoid cyst

Answer

Seminoma

Answer

Embryonal carcinoma

Answer

Yolk sac tumor

Question 4

Ewing's sarcoma arises from which type of cells?

Accepted Answer

Primitive neuroectodermal cells

Answer

G cells

Answer

Totipotent cells

Answer

Neurons

Question 5

Perivascular lymphocytes & microglial nodules are seen in -

Accepted Answer

HIV encephalitis

Answer

CMV meningitis

Answer

Bacterial meningitis

Answer

Multiple sclerosis

Question 6

What is a key difference between fosphenytoin and phenytoin?

Accepted Answer

Can be mixed with saline

Answer

Can be used in absence seizures

Answer

Can be given orally

Answer

It is the drug of choice for myoclonic seizures

Question 7

Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?

Accepted Answer

Beta-2 receptor stimulation

Answer

Adenosine receptor antagonism

Answer

Increased histone deacetylation

Answer

Phosphodiesterase inhibition

Question 8

Omalizumab is primarily used in the treatment of which condition?

Accepted Answer

Asthma

Answer

Breast carcinoma

Answer

Rheumatoid arthritis

Answer

Chronic obstructive pulmonary disease (COPD)

Question 9

Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?

Accepted Answer

Venlafaxine

Answer

Fluoxetine

Answer

Sertraline

Answer

Aripiprazole

Question 10

Which steroid has the maximum mineralocorticoid activity?

Accepted Answer

Fludrocortisone

Answer

DOCA

Answer

Prednisolone

Answer

Triamcinolone

NEET-PG 2012

Internal Medicine

Obstetrics and Gynecology

Pathology

Pharmacology