Biochemistry
1 questionsWhich of the following is true about non-competitive inhibition?
NEET-PG 2020 - Biochemistry NEET-PG Practice Questions and MCQs
Question 301: Which of the following is true about non-competitive inhibition?
- A. Km increases, Vmax remains same
- B. Km decreases, Vmax increases
- C. Km increases, Vmax increases
- D. Km remains same, Vmax decreases (Correct Answer)
Explanation: ***Km remains same, Vmax decreases*** - In **non-competitive inhibition**, the inhibitor binds to an allosteric site on the enzyme, altering its conformation, thereby **reducing its catalytic efficiency**. - This binding does not affect the **enzyme's affinity for the substrate (Km remains the same)**, but it **reduces the maximum reaction rate (Vmax decreases)** because fewer enzyme molecules are able to perform catalysis per unit time. *Km increases, Vmax remains same* - This describes **competitive inhibition**, where the inhibitor competes with the substrate for the enzyme's active site. - While it **increases the apparent Km** (more substrate needed to reach half Vmax), **Vmax remains unchanged** as high substrate concentrations can overcome the inhibition. *Km decreases, Vmax increases* - This scenario would imply an activation rather than inhibition, where both enzyme affinity and catalytic efficiency are enhanced. - This is not characteristic of any standard **enzyme inhibition mechanism**. *Km increases, Vmax increases* - This combination is not observed in any typical **enzyme inhibition pattern**. - An increase in **Vmax** implies enhanced catalytic activity, while an increase in **Km** suggests reduced substrate affinity, which are contradictory effects for a single inhibitor.
Community Medicine
2 questionsBlood bag is discarded in:
Surgical gloves are disposed in which BMW category ?
NEET-PG 2020 - Community Medicine NEET-PG Practice Questions and MCQs
Question 301: Blood bag is discarded in:
- A. Red bag
- B. White bag
- C. Yellow bag (Correct Answer)
- D. Blue bag
Explanation: ***Yellow bag*** - The **yellow bag** is designated for **infectious waste** including human anatomical waste, soiled waste, expired medicines, and **items contaminated with blood and body fluids**. - **Blood bags** are disposed in yellow bags as they contain blood and body fluids, making them **infectious/biohazardous waste**. - According to Biomedical Waste Management Rules, items contaminated with blood fall under Category 1 (Yellow bag) waste. - This ensures safe handling and disposal of potentially infectious materials to prevent pathogen transmission. *Red bag* - The red bag is used for **contaminated recyclable plastic waste** such as tubing, IV sets without fluids, catheters, and plastic bottles. - While blood bags are plastic, their **biohazardous content (blood)** classifies them as infectious waste rather than recyclable contaminated plastic. - Red bag items undergo recycling after disinfection, which is not appropriate for blood-contaminated items. *White bag* - A **white/translucent bag** is used for **sharp waste** including needles, syringes with fixed needles, scalpels, and blades. - Blood bags are not sharp objects and do not pose puncture risk, hence not disposed in white bags. *Blue bag* - The **blue bag** is used for **glassware waste** including broken/unbroken contaminated glass vials and ampoules. - Blood bags are made of plastic, not glass, and their primary hazard is infectious content, not material type.
Question 302: Surgical gloves are disposed in which BMW category ?
- A. Solid Waste
- B. Yellow Category (Infectious Waste) (Correct Answer)
- C. Expired or Discarded Medicines
- D. Human Anatomical Waste
Explanation: ***Yellow Category (Infectious Waste)*** - Surgical gloves are classified as **infectious waste** because they come into contact with blood, body fluids, and other potentially infectious materials during surgical procedures. - The Yellow Category in Bio-Medical Waste Management (BMW) Rules is designated for infectious waste, including items contaminated with **blood and body fluids**. - This is the correct disposal category for used surgical gloves. *Solid Waste* - This is a broad category for general waste that is not infectious or hazardous. - Surgical gloves, due to their potential contamination with infectious materials, are classified more specifically as biomedical waste under the Yellow category, not general solid waste. *Expired or Discarded Medicines* - This category is for pharmaceutical waste, including unused or expired medications. - Surgical gloves are medical devices used for protection, not medicinal products, and therefore do not belong in this category. *Human Anatomical Waste* - This category includes human tissues, organs, body parts, and recognizable anatomical specimens. - Surgical gloves are protective barriers used during procedures, not anatomical waste from the patient, and are classified separately as infectious waste.
Internal Medicine
4 questionsA person was brought to emergency department and was diagnosed with Supra ventricular tachycardia and suddenly he became unstable. What is the next line of management?
A lesion was seen on the face of a 42 year old patient as shown below. Which of the following would be ideal management for this condition?
On esophageal manometry, spastic contractions in the esophageal body with a distal contractile integral (DCI) >8000 mmHg*s*cm are diagnostic of:
Which is not seen in heart failure?
NEET-PG 2020 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 301: A person was brought to emergency department and was diagnosed with Supra ventricular tachycardia and suddenly he became unstable. What is the next line of management?
- A. Intravenous ibutilide
- B. Intravenous Diltiazem
- C. DC Cardioversion (Correct Answer)
- D. Intravenous Flecainide
Explanation: ***DC Cardioversion*** - For **unstable supraventricular tachycardia (SVT)**, immediate **direct current (DC) cardioversion** is the definitive treatment to restore sinus rhythm. - Instability in SVT includes symptoms like hypotension, altered mental status, signs of shock, ischemic chest discomfort, or acute heart failure. *Intravenous ibutilide* - **Ibutilide** is an antiarrhythmic drug used for pharmacological cardioversion of recent-onset atrial fibrillation or flutter, but not typically for unstable SVT. - While it can convert certain supraventricular arrhythmias, it is generally reserved for **stable patients** and takes longer to act than immediate electrical cardioversion. *Intravenous Diltiazem* - **Diltiazem** is a calcium channel blocker used to control ventricular rate in **stable SVT**, atrial fibrillation, or flutter [1]. - It is contraindicated in unstable patients as it can further depress cardiac contractility and worsen hypotension [2]. *Intravenous Flecainide* - **Flecainide** is a class Ic antiarrhythmic drug used to maintain sinus rhythm in patients with supraventricular arrhythmias, including SVT. - It also takes time to act and is used in **stable patients** without structural heart disease, not in emergency unstable situations where immediate rhythm conversion is required.
Question 302: A lesion was seen on the face of a 42 year old patient as shown below. Which of the following would be ideal management for this condition?
- A. Topical retinoids
- B. Oral steroids
- C. Start on MDT for leprosy
- D. Start on ATT (Correct Answer)
Explanation: ***Start on ATT*** - The presented image shows a **gummy lesion** on the face, which is characteristic of **tuberculosis cutis colliquativa**, a form of cutaneous tuberculosis. - **Anti-tubercular therapy (ATT)** is the primary and most effective treatment for all forms of tuberculosis, including cutaneous manifestations. *Topical retinoids* - Topical retinoids are primarily used for **acne vulgaris** and certain **disorders of keratinization** and are not indicated for infectious granulomatous conditions. - They work by **regulating cell growth and differentiation**, which is not the mechanism required to treat tuberculosis. *Oral steroids* - Oral steroids are **immunosuppressive** and generally contraindicated in active infections like tuberculosis, as they can worsen the disease. - While they might be used short-term in some inflammatory skin conditions, they would **not address the underlying tuberculous infection**. *Start on MDT for leprosy* - **Multi-drug therapy (MDT)** is the standard treatment for leprosy, which also presents with skin lesions and nerve involvement. - However, the image shows a **single, nodular, ulcerated lesion** more typical of cutaneous tuberculosis rather than the varied forms of leprosy (macular, papular, nodular lesions, or nerve thickening).
Question 303: On esophageal manometry, spastic contractions in the esophageal body with a distal contractile integral (DCI) >8000 mmHg*s*cm are diagnostic of:
- A. Jackhammer esophagus
- B. Type II achalasia
- C. Type III achalasia (Correct Answer)
- D. Type I achalasia
Explanation: ***Type III achalasia*** - This diagnosis is characterized by the presence of **spastic contractions** in the esophageal body, specifically with a **distal contractile integral (DCI) greater than 8000 mmHg*s*cm**, alongside the classic features of achalasia (impaired LES relaxation and absent peristalsis) [1]. - The elevated DCI reflects the **premature and simultaneous contractions** that are hallmark of this subtype, distinguishing it from other motility disorders [1]. *Jackhammer esophagus* - While it also involves very strong esophageal contractions (**high DCI**), jackhammer esophagus (also known as hypercontractile esophagus) does **not present with impaired LES relaxation or absent peristalsis** as seen in achalasia. - The defining feature of jackhammer esophagus is **multiple rapid swallows** (MRS) that induce simultaneous contractions, often with very high vigor. *Type II achalasia* - This type of achalasia is defined by **pan-esophageal pressurization** in more than 20% of swallows, along with impaired LES relaxation and absent peristalsis. - Unlike Type III, it does **not show the spastic hypercontractile activity** in the esophageal body revealed by a very high DCI. *Type I achalasia* - This is the classic form of achalasia characterized by **absent esophageal peristalsis** and **impaired lower esophageal sphincter (LES) relaxation**, without significant esophageal pressurization or spastic contractions [1]. - It represents the most common subtype and lacks the **high DCI spastic activity** seen in Type III achalasia.
Question 304: Which is not seen in heart failure?
- A. Cardiomegaly
- B. Kerley B lines
- C. Kerley A Lines
- D. Oligemia (Correct Answer)
Explanation: ***Oligemia*** - **Oligemia** refers to a reduced blood volume or total blood flow to a region, which is typically not observed in **heart failure**. - In **heart failure**, the body often experiences **fluid overload** and **pulmonary congestion**, leading to increased blood volume in the lungs, not reduced [1]. *Cardiomegaly* - **Cardiomegaly**, or an enlarged heart, is a common finding in **heart failure** as the heart muscle remodels and dilates to compensate for impaired pumping function [1], [3]. - This can be seen on a chest X-ray as an **increased cardiothoracic ratio** [1], [2]. *Kerley B lines* - **Kerley B lines** are thin, horizontal lines visible on a chest X-ray, typically found at the lung periphery. - They indicate **interstitial edema** due to increased pulmonary venous pressure, a characteristic sign of **pulmonary congestion** in **heart failure** [1]. *Kerley A Lines* - **Kerley A lines** are longer, less common lines seen radiating from the hila towards the upper lobes. - These lines represent **distended anastomotic channels** between pulmonary and systemic venous systems, also indicative of **pulmonary edema** and **heart failure** [1], [4].
Ophthalmology
1 questionsThe shifting fluid sign is characteristic of which condition?
NEET-PG 2020 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 301: The shifting fluid sign is characteristic of which condition?
- A. Exudative retinal detachment (Correct Answer)
- B. Retinal hole
- C. Tractional retinal detachment
- D. Rhegmatogenous retinal detachment
Explanation: ***Exudative retinal detachment (fluid accumulation in subretinal space)*** - The **shifting fluid sign** is pathognomonic for **exudative retinal detachment**, as the subretinal fluid can move with changes in head position due to gravity. - This type of detachment is caused by conditions that lead to abnormal accumulation of fluid under the retina, such as **choroidal tumors**, inflammatory processes, or **severe hypertension**. *Retinal hole (localized retinal break)* - A **retinal hole** is a full-thickness defect in the retina, but it does not inherently cause a shifting fluid sign unless it progresses to a rhegmatogenous detachment. - While it can be a precursor to retinal detachment, the fluid itself is not subject to gravitational shifting in the same way as in exudative detachment. *Tractional retinal detachment (retinal pulling forces)* - **Tractional retinal detachments** occur when **fibrovascular membranes** on the retinal surface contract, pulling the retina away from the underlying choroid. - The detachment is usually localized and fixed by the tractional forces, meaning the fluid (if present) does not shift freely with changes in head position. *Rhegmatogenous retinal detachment (retinal break with vitreous fluid entry)* - This type of detachment involves a **retinal break** through which **liquefied vitreous** gains access to the subretinal space. - Although there is subretinal fluid, the fluid is generally trapped and the detachment is less mobile than in an exudative case; thus, a pronounced shifting fluid sign is not typical.
Pharmacology
1 questionsWhich of the following is not a prokinetic?
NEET-PG 2020 - Pharmacology NEET-PG Practice Questions and MCQs
Question 301: Which of the following is not a prokinetic?
- A. Macrolides
- B. D2 blocker
- C. 5HT4 agonist
- D. Loperamide derivative (Correct Answer)
Explanation: **Loperamide derivative** - **Loperamide** is an **opioid receptor agonist** that acts on the mu-opioid receptors in the gut, primarily to **decrease gastrointestinal motility** and treat diarrhea. - Its mechanism of action directly opposes that of prokinetic agents, which aim to increase GI motility. *Macrolides* - Certain macrolide antibiotics, particularly **erythromycin**, act as **motilin receptor agonists** at low doses. - This agonism leads to increased gastric motility and can be used as a prokinetic in conditions like gastroparesis. *D2 blocker* - **Dopamine D2 receptor antagonists** (e.g., **metoclopramide**, **domperidone**) block the inhibitory effect of dopamine on cholinergic smooth muscle. - This blockade enhances acetylcholine release, leading to increased gastrointestinal motility and prokinetic effects. *5HT4 agonist* - **Serotonin 5-HT4 receptor agonists** (e.g., **cisapride**, **prucalopride**) stimulate the release of acetylcholine and other excitatory neurotransmitters in the enteric nervous system. - This action promotes increased gastrointestinal motility, making them effective prokinetic agents.
Radiology
1 questionsA 55 year old woman diagnosed with ca cervix stage IIb is advised for chemoradiation. Which of the following is the true statement regarding radiation use?
NEET-PG 2020 - Radiology NEET-PG Practice Questions and MCQs
Question 301: A 55 year old woman diagnosed with ca cervix stage IIb is advised for chemoradiation. Which of the following is the true statement regarding radiation use?
- A. Rapidly proliferating cells are less affected by radiation
- B. The small bowel is not significantly affected by radiation
- C. Dose/Intensity of radiation is inversely proportional to the square of distance of source (Correct Answer)
- D. Small blood vessels are unaffected by radiation
Explanation: ***Dose/Intensity of radiation is inversely proportional to the square of distance of source*** - This statement accurately describes the **inverse square law** which governs radiation intensity. As the distance from the radiation source increases, the dose or intensity of radiation decreases proportionally to the square of that distance. - This principle is crucial in **radiation safety** and treatment planning to ensure appropriate dose delivery and minimize exposure to non-target tissues. *Rapidly proliferating cells are less affected by radiation* - This is incorrect; **rapidly proliferating cells** are generally **more sensitive to radiation** because radiation primarily targets cells undergoing division, causing DNA damage. - Tissues with high cellular turnover, like bone marrow and gastrointestinal lining, are highly susceptible to radiation-induced damage. *The small bowel is not significantly affected by radiation* - This is incorrect; the **small bowel** is one of the most **radiosensitive organs** due to its rapidly proliferating epithelial cells. - Radiation to the abdomen and pelvis, common in cervical cancer treatment, frequently causes symptoms such as **nausea, vomiting, diarrhea**, and long-term complications like enteritis and strictures. *Small blood vessels are unaffected by radiation* - This is incorrect; **small blood vessels**, particularly the **endothelium**, are quite susceptible to radiation damage. - Radiation can cause **endothelial cell swelling**, damage, and sclerosis, leading to vascular insufficiency, fibrosis, and impaired tissue healing.