Dermatology
1 questionsRaindrop pigmentation is caused by?
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 611: Raindrop pigmentation is caused by?
- A. Dapsone
- B. Minocycline
- C. Clofazimine
- D. Arsenic (Correct Answer)
Explanation: ***Arsenic*** - Chronic **arsenic** exposure can lead to characteristic skin manifestations, including **raindrop pigmentation**, which appears as small, scattered hypopigmented macules surrounded by hyperpigmented skin, particularly on the trunk and extremities. - This pigmentation is a result of altered **melanin distribution** and **keratinocyte damage** due to arsenic toxicity. *Clofazimine* - **Clofazimine** is an anti-leprosy drug that can cause **reddish-brown to bluish-black skin discoloration**, which is a diffuse pigmentation, not "raindrop" in nature. - The pigmentation associated with clofazimine is due to drug deposition in tissues and is usually reversible. *Dapsone* - **Dapsone** is primarily known for causing **methemoglobinemia** and **hemolytic anemia**, especially in patients with G6PD deficiency. - While it can cause some dermatological side effects, **pigmentation** is not a characteristic feature, and it does not produce a "raindrop" pattern. *Minocycline* - **Minocycline** can cause various types of pigmentation, including **blue-gray discoloration** in scars, shins, and mucous membranes, as well as diffuse brown pigmentation. - However, the pigmentation caused by minocycline is typically diffuse or localized to specific areas, and it does not present as "raindrop pigmentation."
Forensic Medicine
2 questionsThe odour of cyanide is similar to?
What is the effect of strychnos nux vomica poisoning on a patient's consciousness?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 611: The odour of cyanide is similar to?
- A. Rotten egg
- B. Fish
- C. Fruity
- D. Bitter almond (Correct Answer)
Explanation: ***Bitter almond*** - The classic description of **cyanide odor** is that of **bitter almonds**. This specific scent is a key indicator during forensic investigations or in cases of suspected poisoning. - However, not everyone can detect this smell due to a **genetic trait** that affects the ability to perceive it. *Rotten egg* - A **rotten egg** odor is characteristic of **hydrogen sulfide (H2S)**, a highly toxic gas. - This gas is often produced by the decomposition of organic matter and does not indicate cyanide exposure. *Fish* - A **fishy odor** is typically associated with compounds like **amines**, such as **trimethylamine**, which are found in decomposing fish or certain medical conditions like **trimethylaminuria**. - This smell is distinct from the bitter almond scent of cyanide. *Fruity* - A **fruity odor** can be associated with various substances, including **ketones** in conditions like **diabetic ketoacidosis** or certain **volatile organic compounds**. - This scent is not characteristic of cyanide poisoning.
Question 612: What is the effect of strychnos nux vomica poisoning on a patient's consciousness?
- A. Becomes unconscious within an hour
- B. Becomes unconscious only in severe cases
- C. Remains conscious throughout the poisoning (Correct Answer)
- D. Becomes unconscious immediately after exposure
Explanation: ***Remains conscious throughout the poisoning*** - Patients poisoned with **strychnine** (from *Strychnos nux vomica*) typically remain **fully conscious** and aware of their surroundings, even during severe convulsions. - This preservation of consciousness amidst intense muscular spasms is a **distinguishing and agonizing feature** of strychnine poisoning. *Becomes unconscious within an hour* - This statement is generally incorrect for strychnine poisoning, as the prominent feature is maintained consciousness alongside **neurological excitability**. - Loss of consciousness is not a **primary or direct effect** of strychnine, though severe complications could indirectly affect it. *Becomes unconscious only in severe cases* - While extreme metabolic derangements or secondary complications (e.g., severe hypoxia from prolonged seizures) might eventually lead to altered consciousness, the **direct pharmacological action** of strychnine does not cause unconsciousness. - The patient remains conscious even through the most severe and life-threatening **tetanic spasms**. *Becomes unconscious immediately after exposure* - Strychnine primarily acts as an **antagonist to glycine receptors** in the spinal cord and brainstem, leading to exaggerated reflexes and muscle overactivity, not immediate unconsciousness. - The onset of symptoms, including muscular spasms, typically occurs within **15-30 minutes** of exposure, with consciousness generally preserved.
Pathology
1 questionsPerivascular lymphocytes & microglial nodules are seen in -
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 611: Perivascular lymphocytes & microglial nodules are seen in -
- A. HIV encephalitis (Correct Answer)
- B. CMV meningitis
- C. Bacterial meningitis
- D. Multiple sclerosis
Explanation: ***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.
Pharmacology
5 questionsWhat is a key difference between fosphenytoin and phenytoin?
Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?
Omalizumab is primarily used in the treatment of which condition?
Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?
What is the antidote for Ethylene Glycol?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 611: What is a key difference between fosphenytoin and phenytoin?
- A. Can be used in absence seizures
- B. Can be mixed with saline (Correct Answer)
- C. Can be given orally
- D. It is the drug of choice for myoclonic seizures
Explanation: **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.
Question 612: Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?
- A. Adenosine receptor antagonism
- B. Increased histone deacetylation
- C. Phosphodiesterase inhibition
- D. Beta-2 receptor stimulation (Correct Answer)
Explanation: ***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.
Question 613: Omalizumab is primarily used in the treatment of which condition?
- A. Breast carcinoma
- B. Asthma (Correct Answer)
- C. Rheumatoid arthritis
- D. Chronic obstructive pulmonary disease (COPD)
Explanation: ***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.
Question 614: Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?
- A. Fluoxetine
- B. Venlafaxine (Correct Answer)
- C. Sertraline
- D. Aripiprazole
Explanation: ***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.
Question 615: What is the antidote for Ethylene Glycol?
- A. Barbiturate
- B. Acetylcysteine
- C. Ferric chloride
- D. Fomepizole (Correct Answer)
Explanation: ***Fomepizole*** - **Fomepizole** is the primary and preferred antidote for ethylene glycol poisoning, as it competitively inhibits **alcohol dehydrogenase**, the enzyme responsible for metabolizing ethylene glycol into its toxic metabolites. - By blocking this enzyme, fomepizole prevents the formation of harmful compounds like **glycolic acid** and **oxalic acid**, which cause metabolic acidosis and kidney damage. - **Ethanol** is an alternative antidote that works by the same mechanism (competitive inhibition of alcohol dehydrogenase) and can be used when fomepizole is unavailable, though fomepizole is preferred due to better safety profile and easier dosing. *Barbiturate* - **Barbiturates** are a class of psychoactive drugs that act as central nervous system depressants, primarily used for sedation, anesthesia, and seizure control. - They have no role in neutralizing or metabolizing ethylene glycol or its toxic byproducts. *Acetylcysteine* - Acetylcysteine is an antidote primarily used for **acetaminophen (paracetamol) overdose**, where it replenishes glutathione stores and detoxifies its toxic metabolite, **NAPQI**. - It does not have any direct antidotal effect against ethylene glycol or its metabolites. *Ferric chloride* - **Ferric chloride** is a chemical compound used in various industrial processes, water treatment, and as a laboratory reagent. - It is highly corrosive and toxic if ingested, but it is not used as an antidote for any type of poisoning, including ethylene glycol.
Surgery
1 questionsWhich of the following actions is NOT recommended when dealing with a patient who has been bitten by a snake?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 611: Which of the following actions is NOT recommended when dealing with a patient who has been bitten by a snake?
- A. Reassurance
- B. Immobilization of the affected limb
- C. Clean with soap and water
- D. Local incision (Correct Answer)
Explanation: ***Local incision*** - Making an incision at the bite site can **worsen tissue damage**, increase the risk of infection, and does not effectively remove venom. - This practice is **outdated** and potentially harmful, as venom spreads rapidly through the lymphatic system rather than being localized in a way that incision can help. - **Local incision is NOT recommended** and is a contraindicated first-aid measure. *Immobilization of the affected limb* - Immobilizing the bitten limb helps **slow the spread of venom** through the lymphatic system. - This is a **recommended first-aid measure**, especially for neurotoxic snakebites, and should be done by keeping the limb at or below heart level. - Proper immobilization involves splinting the limb without restricting blood flow. *Reassurance* - Overt fear and anxiety can lead to symptoms like **tachycardia** and **hypertension**, which can exacerbate the effects of the venom. - **Calming the patient** helps reduce the physiological stress response, which is crucial as panic can worsen the clinical picture. - Reassurance is a **recommended supportive measure**. *Clean with soap and water* - Cleaning the wound helps remove surface venom and **reduce the risk of secondary bacterial infection**. - This is a **recommended basic first-aid measure** that promotes wound hygiene without interfering with venom management.