Community Medicine
1 questionsIn the context of disease screening, which type of lead time is most beneficial for effective screening?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 731: In the context of disease screening, which type of lead time is most beneficial for effective screening?
- A. Short lead time
- B. Both short and long lead times are beneficial
- C. Long lead time is beneficial for screening (Correct Answer)
- D. Lead time has no impact on screening effectiveness
Explanation: ***Long lead time is beneficial for screening*** - **Long lead time** provides a greater window of opportunity between disease detection by screening and clinical symptom onset - This extended asymptomatic detectable phase allows for **early intervention** when treatments are most effective - Longer lead time correlates with improved prognosis and potential prevention of severe outcomes - Essential criterion for effective screening programs per **Wilson-Jungner criteria** *Short lead time* - Limited time between disease detectability and clinical symptoms - Reduces screening effectiveness as disease progresses rapidly - Minimal opportunity for beneficial early intervention *Both short and long lead times are beneficial* - Only **long lead time** is beneficial for screening programs - Short lead time actually limits screening effectiveness - Screening benefit is directly proportional to duration of asymptomatic detectable phase *Lead time has no impact on screening effectiveness* - **Lead time is crucial** for determining screening program effectiveness - Directly impacts the window for early detection and intervention - Without adequate lead time, screening loses its preventive value
Forensic Medicine
1 questionsWhich of the following statements about exit wounds of a bullet in bone is correct?
NEET-PG 2013 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 731: Which of the following statements about exit wounds of a bullet in bone is correct?
- A. Abrasion collar
- B. Smaller than entry wound
- C. Presence of COHb
- D. Bevelled (Correct Answer)
Explanation: ***Bevelled*** - Beveling (internal beveling) is the **characteristic feature** of exit wounds in bone, particularly in skull fractures - The exit wound shows a **cone-shaped defect** with the **wider opening on the exit side** and the narrow end toward the entry side - This "coning effect" occurs because bone fragments are **pushed outward** as the bullet exits, creating a larger, more irregular defect - **Definitive forensic finding** for distinguishing entry from exit wounds in bone *Smaller than entry wound* - This is **incorrect** for bone wounds - Exit wounds in bone are typically **larger and more irregular** than entry wounds, not smaller - The entry wound in bone appears as a small, punched-in defect with **external beveling** (narrow on outside, wider on inside) - Exit wounds are larger due to the bullet's tumbling and fragmentation, plus outward force creating the beveling *Abrasion collar* - An **abrasion collar** (marginal abrasion) is characteristic of **entry wounds in skin**, not bone - Occurs when skin is pressed inward and abraded by the bullet at entry - **Not present** around exit wounds because skin is pushed outward, causing irregular tearing - This feature applies to soft tissue, not bone wound characteristics *Presence of COHb* - **Carboxyhemoglobin (COHb)** indicates a **close-range gunshot entry wound** - Results from carbon monoxide in gunpowder gases deposited in the wound tract - Associated with **entry wounds only**, particularly at close range or contact wounds - Not relevant to exit wound characteristics
Internal Medicine
1 questionsWhich of the following characteristics can be used to differentiate the rash of chickenpox from the rash of smallpox?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 731: Which of the following characteristics can be used to differentiate the rash of chickenpox from the rash of smallpox?
- A. Deep-seated
- B. Pleomorphic (Correct Answer)
- C. Centrifugal
- D. Multilocular
Explanation: ***Pleomorphic*** - The rash of **chickenpox** is **pleomorphic**, meaning lesions at various stages of development (macules, papules, vesicles, scabs) are present simultaneously in the same body area. - In contrast, a **smallpox** rash is **monomorphic**, with all lesions in a given area appearing at the same stage of development. *Centrifugal* - A **centrifugal distribution** (lesions more concentrated on the face and extremities) is characteristic of **smallpox**. - **Chickenpox** typically has a **centripetal distribution**, with lesions more concentrated on the trunk. *Deep-seated* - **Smallpox** lesions are described as **deep-seated** and feel like "shot under the skin," often associated with significant scarring. - **Chickenpox** lesions are superficial and less likely to cause scarring unless secondarily infected. *Multilocular* - **Smallpox** vesicles and pustules are typically **multilocular**, meaning they have internal septations and do not collapse when punctured. - **Chickenpox** vesicles are unilocular, appearing as a single compartment, and collapse when punctured.
Microbiology
4 questionsWhat is the most common genetic factor associated with increased susceptibility to Neisseria infections?
Which is the most common bacterial organism causing bacterial upper respiratory tract infections (including sinusitis, otitis media, and pharyngitis) in adults?
Which of the following statements about Corynebacterium diphtheriae is NOT true?
Which of the following statements regarding resistance of penicillin in Staphylococcus aureus is false?
NEET-PG 2013 - Microbiology NEET-PG Practice Questions and MCQs
Question 731: What is the most common genetic factor associated with increased susceptibility to Neisseria infections?
- A. HLA-B27
- B. Complement deficiency (Correct Answer)
- C. IgA deficiency
- D. Factor H deficiency
Explanation: ***Complement deficiency*** - Deficiencies in the **terminal complement pathway (C5-C9)**, particularly C5b-C9 (membrane attack complex, MAC), significantly increase susceptibility to disseminated *Neisseria* infections. - The MAC is crucial for lysing Gram-negative bacteria like *Neisseria meningitidis* and *Neisseria gonorrhoeae*, and its absence allows for uncontrolled bacterial proliferation. *Factor H deficiency* - **Factor H** is a regulatory protein of the alternative complement pathway, preventing its overactivation on host cells. - Its deficiency typically leads to conditions like **atypical hemolytic uremic syndrome (aHUS)** and **dense deposit disease**, not primarily increased susceptibility to *Neisseria* infections. *HLA B27* - **HLA-B27** is a human leukocyte antigen strongly associated with a group of autoimmune inflammatory diseases called **spondyloarthropathies**, such as ankylosing spondylitis. - It does not directly impact the immune response to *Neisseria* infections or increase susceptibility to them. *IgA deficiency* - **Selective IgA deficiency** is the most common primary immunodeficiency, characterized by low or absent IgA levels. - Individuals with IgA deficiency are more prone to **recurrent respiratory and gastrointestinal infections**, but not specifically disseminated *Neisseria* infections.
Question 732: Which is the most common bacterial organism causing bacterial upper respiratory tract infections (including sinusitis, otitis media, and pharyngitis) in adults?
- A. Staphylococcus aureus
- B. Haemophilus influenzae
- C. Streptococcus pyogenes
- D. Streptococcus pneumoniae (Correct Answer)
Explanation: ***Streptococcus pneumoniae*** - *Streptococcus pneumoniae* is the **most common bacterial pathogen** causing upper respiratory tract infections overall, including **bacterial sinusitis**, **otitis media**, and **community-acquired pneumonia**. - It is a frequent colonizer of the nasopharynx and leads to infection when host immunity is compromised. - Accounts for the highest burden of bacterial URTIs when considering all anatomical sites. *Haemophilus influenzae* - *Haemophilus influenzae* (particularly non-typeable strains) is the **second most common** cause of bacterial sinusitis and otitis media in adults. - While significant, it is less prevalent overall than *S. pneumoniae* across all URTI types. *Staphylococcus aureus* - *Staphylococcus aureus* primarily causes **skin and soft tissue infections** and device-related infections. - It is **not a common primary pathogen** in typical acute bacterial URTIs, though it may cause secondary infections or colonize the anterior nares. *Streptococcus pyogenes* - *Streptococcus pyogenes* (Group A Streptococcus) is the **most common cause of bacterial pharyngitis** (strep throat) in adults. - However, when considering the **full spectrum of bacterial URTIs** (pharyngitis, sinusitis, otitis media), *S. pneumoniae* has a broader overall impact and higher prevalence across multiple sites.
Question 733: Which of the following statements about Corynebacterium diphtheriae is NOT true?
- A. Has metachromatic granules
- B. Toxin mediated by chromosomal gene (Correct Answer)
- C. Toxigenicity demonstrated by elek's test
- D. Does not invade deeper tissues
Explanation: ***Toxin mediated by chromosomal gene*** - The **diphtheria toxin** is encoded by the **tox gene**, which is a lysogenic bacteriophage (cornyphage) gene, not a chromosomal gene. - This **bacteriophage** integrates into the bacterial chromosome, making toxigenic *C. diphtheriae* strains lysogenized. *Has metachromatic granules* - *Corynebacterium diphtheriae* is known for possessing **metachromatic granules** (also called Babes-Ernst bodies), which are inclusions that stain differently from the rest of the cell. - These granules are composed of **polyphosphate reserves** and are important for identification. *Does not invade deeper tissues* - *Corynebacterium diphtheriae* remains **localized** to the mucosal surface of the upper respiratory tract or skin, forming a **pseudomembrane**. - Its pathogenicity is primarily due to the **exotoxin** it produces, which then disseminates systemically. *Toxigenicity demonstrated by elek's test* - The **Elek test** is a standard laboratory assay used to determine the **toxigenicity** of *Corynebacterium diphtheriae* strains by detecting the production of diphtheria toxin. - It works by identifying the **immunoprecipitation lines** formed between antitoxin and toxin in an agar medium.
Question 734: Which of the following statements regarding resistance of penicillin in Staphylococcus aureus is false?
- A. Methicillin resistance is due to alterations in penicillin-binding proteins (PBPs).
- B. Penicillinase production is mediated by plasmids.
- C. Hospital strains predominantly produce a unique type of penicillinase. (Correct Answer)
- D. Penicillinase production can be transmitted by transduction.
Explanation: ***Hospital strains predominantly produce a unique type of penicillinase*** - This statement is **false** because hospital strains do not produce a truly "unique type" of **penicillinase** compared to community strains. - **Penicillinase (beta-lactamase)** is a common resistance mechanism found across various *S. aureus* strains, not exclusive to hospital environments. *Methicillin resistance is due to alterations in penicillin-binding proteins (PBPs)* - This statement is **true** as **MRSA** resistance involves the **mecA gene** encoding **PBP2a**. - **PBP2a** has low affinity for **beta-lactam antibiotics**, allowing cell wall synthesis despite antibiotic presence. *Penicillinase production is mediated by plasmids* - This statement is **true** because **penicillinase genes** are typically located on **plasmids**. - **Plasmids** facilitate horizontal transfer of resistance genes between bacterial populations. *Penicillinase production can be transmitted by transduction* - This statement is **true** as **transduction** via **bacteriophages** can transfer resistance genes. - **Plasmid-borne penicillinase genes** can spread through this horizontal gene transfer mechanism.
Pediatrics
2 questions2 months old child having birth weight 2kg, with poor feeding, very sleepy and wheezing. The diagnosis is?
A 3-month-old infant with no chest indrawing and a respiratory rate of 52/minute. The diagnosis is:
NEET-PG 2013 - Pediatrics NEET-PG Practice Questions and MCQs
Question 731: 2 months old child having birth weight 2kg, with poor feeding, very sleepy and wheezing. The diagnosis is?
- A. Very severe disease (Correct Answer)
- B. No evidence of pneumonia
- C. Severe respiratory infection
- D. No diagnosis
Explanation: ***Very severe disease*** - According to **WHO/IMNCI (Integrated Management of Neonatal and Childhood Illness) classification** for young infants (0-2 months), the presence of **danger signs** automatically classifies the condition as "Very severe disease" - This infant presents with two critical danger signs: **poor feeding** and **lethargy (very sleepy)**, along with respiratory symptoms (wheezing) - In young infants, any danger sign (poor feeding, lethargic/unconscious, convulsions, severe chest indrawing, central cyanosis) requires immediate classification as "Very severe disease" and **urgent referral** to higher center - This is a specific diagnostic classification used in pediatric emergency protocols, not a general term *Severe respiratory infection* - While the child has respiratory symptoms (wheezing), this classification would only be appropriate if respiratory distress was present **without danger signs** - The presence of danger signs (poor feeding, lethargy) escalates the classification to "Very severe disease" in the WHO/IMNCI protocol - In young infants (0-2 months), the classification system prioritizes danger signs over organ-specific diagnoses *No evidence of pneumonia* - This is incorrect as the infant clearly presents with respiratory symptoms (wheezing) and systemic signs of illness - The presence of wheezing, poor feeding, and lethargy indicates serious illness requiring urgent evaluation and treatment - This option contradicts the clinical presentation *No diagnosis* - This is incorrect as the WHO/IMNCI classification provides a clear diagnostic framework - The presence of danger signs in a young infant mandates classification as "Very severe disease" - A working diagnosis is essential for guiding appropriate management and urgent referral
Question 732: A 3-month-old infant with no chest indrawing and a respiratory rate of 52/minute. The diagnosis is:
- A. Severe pneumonia
- B. Pneumonia (Correct Answer)
- C. No pneumonia
- D. Very severe disease
Explanation: ***Pneumonia*** - A respiratory rate of 52/minute in a 3-month-old infant **meets the age-specific threshold for tachypnea** (respiratory rate ≥ 50 breaths/minute for infants 2-12 months according to IMCI guidelines). - In the **absence of chest indrawing**, the presence of fast breathing (tachypnea) alone classifies this as **pneumonia** per IMCI classification. - This requires **outpatient management with oral antibiotics** and close follow-up. *No pneumonia* - This diagnosis would apply if the respiratory rate was **< 50 breaths/minute** for this age group with no chest indrawing. - Since the respiratory rate is 52/minute (≥ 50/minute), this rules out "no pneumonia." *Severe pneumonia* - This diagnosis requires the presence of **chest indrawing** in addition to fast breathing. - The question explicitly states **"no chest indrawing,"** which excludes severe pneumonia. - Severe pneumonia would require **hospitalization and parenteral antibiotics**. *Very severe disease* - This diagnosis involves **danger signs** such as inability to drink or breastfeed, persistent vomiting, convulsions, lethargy, unconsciousness, or severe malnutrition. - None of these critical signs are mentioned in the clinical scenario. - Very severe disease requires **urgent hospitalization and injectable antibiotics**.
Surgery
1 questionsIn blast injury, which organ is most likely to be damaged first?
NEET-PG 2013 - Surgery NEET-PG Practice Questions and MCQs
Question 731: In blast injury, which organ is most likely to be damaged first?
- A. Tympanic membrane (Correct Answer)
- B. Liver
- C. Lung
- D. Gastrointestinal tract
Explanation: ***Tympanic membrane*** - The **tympanic membrane** is the most sensitive organ to the pressure waves generated by a blast, often rupturing even with relatively low blast overpressures. - Its thin, delicate structure and direct exposure to external air pressure make it highly vulnerable to barotrauma. *Gastrointestinal tract* - While the **gastrointestinal tract** can be damaged by blast waves, especially air-filled organs, this typically occurs after the tympanic membrane is affected. - Damage often includes hemorrhage, perforation, and mesenteric injury. *Liver* - The **liver** is a solid organ and is less susceptible to initial blast injury compared to air-filled structures. - Damage to the liver usually results from secondary mechanisms like blunt trauma from displacement or impact against other structures. *Lung* - **Blast lung** is a serious injury characterized by pulmonary contusions, hemorrhage, and edema, but it generally requires higher blast overpressure than tympanic membrane rupture. - The air-filled nature of the lungs makes them susceptible, but the tympanic membrane almost always fails first.