Forensic Medicine
1 questionsWhat substance is measured in the vitreous humor to estimate the time since death?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 671: What substance is measured in the vitreous humor to estimate the time since death?
- A. Sodium
- B. Potassium (Correct Answer)
- C. Proteins
- D. Chloride
Explanation: ***Potassium*** - **Potassium** concentration in the vitreous humor increases predictably after death due to the breakdown of cellular membranes and passive diffusion from cells. - This consistent post-mortem rise makes it a reliable marker for estimating the **post-mortem interval** (PMI) or time since death. *Sodium* - While sodium is present in the vitreous humor, its post-mortem changes are not as consistent or predictable as potassium for estimating the **time since death**. - Sodium levels tend to decrease slightly after death, but this decline is influenced by various factors and is less reliable for **PMI determination**. *Proteins* - **Proteins** are generally stable in the vitreous humor for some time post-mortem, but their levels do not show a consistent or predictable change that can be used to accurately estimate the **time since death**. - Measuring protein levels is more useful in assessing specific eye pathologies rather than **PMI**. *Chloride* - **Chloride** concentrations in the vitreous humor exhibit post-mortem changes, but like sodium, they are not as precise or reliable as potassium for estimating the **post-mortem interval**. - Its diffusion out of the vitreous humor can be more variable and less consistently linear than potassium's influx.
Internal Medicine
1 questionsWhat condition is caused by the intake of exogenous steroids?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 671: What condition is caused by the intake of exogenous steroids?
- A. Addison's disease
- B. Cushing's syndrome (Correct Answer)
- C. Pheochromocytoma
- D. Conn's syndrome
Explanation: ***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.
Microbiology
1 questionsKatayama fever is caused by which of the following?
NEET-PG 2012 - Microbiology NEET-PG Practice Questions and MCQs
Question 671: Katayama fever is caused by which of the following?
- A. F. hepatica
- B. C. sinensis
- C. A. lumbricoides
- D. S. japonicum (Correct Answer)
Explanation: ***Correct: S. japonicum*** - Katayama fever, also known as **acute schistosomiasis**, is a systemic hypersensitivity reaction to the migrating schistosomula and oviposition of eggs that primarily occurs in infections with **_Schistosoma japonicum_** or _S. mansoni_. - It presents with fever, chills, cough, diarrhea, abdominal pain, hepatosplenomegaly, and eosinophilia, typically 2-8 weeks after exposure to contaminated water. - S. japonicum tends to cause the most severe form of Katayama fever. *Incorrect: F. hepatica* - **_Fasciola hepatica_** causes fascioliasis, an infection of the bile ducts and liver, which can present with fever and eosinophilia, but it does not typically cause the acute systemic reaction known as Katayama fever. - The disease is usually acquired by ingesting **metacercariae** on aquatic vegetation or in contaminated water. *Incorrect: C. sinensis* - **_Clonorchis sinensis_** is the Chinese liver fluke, causing clonorchiasis, an infection primarily of the bile ducts. - Symptoms are often mild or asymptomatic but can include abdominal pain, indigestion, diarrhea, and jaundice in heavy infections, without the distinct acute systemic syndrome of Katayama fever. *Incorrect: A. lumbricoides* - **_Ascaris lumbricoides_** is a roundworm that causes ascariasis, primarily affecting the gastrointestinal tract. - While it can cause pulmonary symptoms during larval migration (Löffler's syndrome), it does not cause Katayama fever, which is specific to schistosomiasis.
Pharmacology
7 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?
Which steroid has the maximum mineralocorticoid activity?
Which statin is considered most potent based on mg-to-mg LDL reduction capability?
Which of the following antiepileptic drugs is most classically associated with causing hirsutism?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 671: 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 672: 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 673: 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 674: 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 675: Which steroid has the maximum mineralocorticoid activity?
- A. Fludrocortisone (Correct Answer)
- B. DOCA
- C. Prednisolone
- D. Triamcinolone
Explanation: ***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 676: Which statin is considered most potent based on mg-to-mg LDL reduction capability?
- A. Simvastatin
- B. Pravastatin
- C. Rosuvastatin (Correct Answer)
- D. Atorvastatin
Explanation: ***Rosuvastatin*** - **Rosuvastatin** is known for its high potency, achieving significant **LDL-C reduction** at relatively low doses. - It is often considered the most potent statin on a **milligram-to-milligram basis**. *Simvastatin* - **Simvastatin** is a moderate-intensity statin, not as potent as rosuvastatin or atorvastatin in reducing LDL-C. - While effective, it typically requires higher doses to achieve comparable **LDL-C reductions** seen with high-potency statins. *Pravastatin* - **Pravastatin** is a hydrophilic statin, generally considered to be of lower potency compared to other statins like rosuvastatin and atorvastatin. - It is often used in patients with **hepatic dysfunction** due to its different metabolic profile but offers less aggressive **LDL-C reduction**. *Atorvastatin* - **Atorvastatin** is a high-intensity statin, very effective in reducing LDL-C, and often used for aggressive lipid lowering. - While highly potent, **atorvastatin** is generally considered slightly less potent than **rosuvastatin** on a mg-to-mg basis, though both are used for high-intensity lipid therapy.
Question 677: Which of the following antiepileptic drugs is most classically associated with causing hirsutism?
- A. Phenytoin (Correct Answer)
- B. Valproate
- C. Carbamazepine
- D. Phenobarbitone
Explanation: ***Phenytoin*** - **Phenytoin** is the **most classically associated** antiepileptic drug with **hirsutism**, which is abnormal/excessive growth of hair [1]. - The mechanism involves changes in **androgen metabolism** and stimulation of hair follicle growth. - Other cosmetic side effects include **gingival hyperplasia** and **coarsening of facial features** [1].*Valproate* - Valproate can paradoxically cause both **hair loss (alopecia)** and **hirsutism**, particularly in women and children. - However, phenytoin has a **stronger and more classical association** with hirsutism. - Valproate is also known for **weight gain**, **hepatotoxicity**, **pancreatitis**, and **teratogenicity**.*Carbamazepine* - Carbamazepine's common side effects include **drowsiness**, **dizziness**, **diplopia**, and **hyponatremia**. - It is not classically linked to **hirsutism** as a prominent adverse effect. - Can cause **agranulocytosis** and **Stevens-Johnson syndrome** in rare cases.*Phenobarbitone* - Phenobarbitone is an older antiepileptic drug associated with **sedation**, **cognitive impairment**, and **dependence**. - It does not commonly cause **hirsutism**. - Also causes **enzyme induction** leading to multiple drug interactions.