NEET-PG 2015 Practice Questions

Q: Vaccine derived polio virus outbreaks are due to?

Type-2 poliovirus. ***Type-2 poliovirus*** - The **type 2 poliovirus (PV2)** component of the oral polio vaccine (OPV) has historically been associated with the majority of vaccine-derived poliovirus (VDPV) outbreaks. - The **attenuated PV2 strain** in OPV can revert to neurovirulent forms in rare cases, leading to outbreaks, especially in areas with low vaccination coverage. - Type 2 was responsible for **>90% of circulating VDPV (cVDPV) cases**, which led to the global switch from trivalent OPV to bivalent OPV (without type 2) in April 2016. *Type-3 poliovirus* - While **type 3 poliovirus (PV3)** was also part of OPV, **wild type 3 poliovirus was declared eradicated in 2019** (last case in 2012). - VDPV outbreaks due to PV3 are rare compared to PV2. *Type-1 poliovirus* - **Type 1 poliovirus (PV1)** is still endemic in some regions and causes wild poliovirus (WPV) infections. - Although PV1 is included in bivalent OPV, **VDPV outbreaks** from the PV1 component are very rare compared to PV2. *All types of poliovirus* - While all three serotypes of poliovirus were historically included in trivalent OPV, **PV2 is overwhelmingly responsible** for VDPV outbreaks. - **Wild type 2 poliovirus was eradicated in 2015** (last case 1999), but the vaccine strain continued to cause VDPV outbreaks until type 2 was removed from routine OPV.

Q: Which area is typically not involved in a chickenpox rash?

Palms and soles. ***Palms and soles*** - The chickenpox rash, caused by the **varicella-zoster virus**, typically spares the palms and soles. - Chickenpox exhibits a characteristic **centripetal distribution** (center-predominant), with lesions most numerous on the trunk and progressively fewer on the extremities. - **Sparing of palms and soles** is a classic differentiating feature from other viral exanthems like hand-foot-and-mouth disease. *Trunk* - The **trunk** is usually the **most heavily involved area** in a chickenpox rash, with lesions often appearing first and being most numerous here. - This is the hallmark of the characteristic **centripetal distribution** of the rash. *Axilla* - The **axilla** is a common site for chickenpox lesions due to its location on the trunk and the presence of **warm, moist skin folds** that can favor lesion development. - The rash tends to be widespread, making secondary sites like the axilla commonly involved. *Back* - The **back** is a major part of the trunk and is therefore extensively involved in a chickenpox rash. - The rash often starts on the trunk and spreads outwards, ensuring significant involvement of the back.

Q: Which of the following is not a complication of maxillary sinus lavage and insufflation?

Facial nerve injury. ***Facial nerve injury*** - The **facial nerve (CN VII)** passes through the parotid gland and temporal bone, far from the maxillary sinus. - There is no anatomical proximity or procedural mechanism during maxillary sinus lavage and insufflation that would put the facial nerve at risk of injury. *Air embolism* - **Insufflation of air** into the maxillary sinus, especially under pressure, can lead to air entering the bloodstream if a blood vessel is inadvertently punctured. - This can result in a serious and potentially fatal **air embolism**, particularly if the air reaches the cerebral circulation. *Orbital injury* - The **medial wall of the maxillary sinus** is in close proximity to the orbit, separated by thin bone. - During lavage, excessive force or incorrect angulation of instruments can perforate this thin bone, leading to **orbital complications** such as periorbital hematoma or injury to orbital contents. *Epistaxis* - During the procedure, the **mucosa of the nasal cavity** or the sinus itself can be traumatized by the instruments used for lavage. - This local trauma to the rich blood supply of these areas can easily cause **nasal bleeding (epistaxis)**.

Q: What is the treatment of choice for ethmoidal polyps?

Functional Endoscopic sinus surgery with polypectomy. ***Functional Endoscopic sinus surgery with polypectomy*** - This is the **gold standard treatment** for ethmoidal polyps, as it allows for **direct visualization** and complete removal of polyps while preserving healthy mucosa. - It also enables restoration of normal sinus ventilation and drainage, which helps prevent recurrence. *Intranasal ethmoidectomy* - This is an **older technique** that is performed blindly and carries a higher risk of complications, such as **orbital or intracranial injury**, compared to endoscopic approaches. - It often results in incomplete polyp removal, leading to a higher rate of recurrence. *Transantral ethmoidectomy* - This approach, also known as the **Caldwell-Luc procedure**, is primarily used for diseases of the **maxillary sinus** and is not the preferred method for isolated ethmoidal polyps. - It is a more invasive external approach with risks including facial swelling, pain, and damage to dental nerves. *Extranasal ethmoidectomy* - This is a more invasive **external approach** involving an incision on the face and is generally reserved for extensive or complicated cases, such as **tumors or severe trauma**, not for routine polyp removal. - It carries risks of visible scarring and longer recovery times, making it less favorable than endoscopic techniques.

Q: Which of the following is not recommended for patients with coronary artery disease?

Vitamin E. ***Vitamin E*** - **Vitamin E supplements** are generally not recommended for patients with coronary artery disease (CAD) based on current evidence. Some studies suggest a potential link between high doses of vitamin E and an increased risk of **heart failure** or even **overall mortality**. - There is no convincing evidence that vitamin E supplements provide cardiovascular benefits in patients with established CAD, and they may interfere with the efficacy of other beneficial medications like **statins**. *Daily exercise* - **Regular physical activity** is a cornerstone of CAD management, improving cardiovascular fitness, reducing blood pressure, and aiding in weight control [1]. - It helps in preventing disease progression and reducing the risk of future cardiovascular events when performed under appropriate medical guidance [1]. *Potassium* - Maintaining adequate **potassium levels** is crucial for patients with CAD, especially those on diuretics, as it helps regulate **blood pressure** and prevents **cardiac arrhythmias**. - Dietary sources of potassium (fruits, vegetables) are preferred, and supplementation may be necessary for those with deficiencies, but always under medical supervision. *Statins* - **Statins** are a class of medications widely recommended for patients with CAD due to their ability to significantly lower **LDL cholesterol** levels and reduce cardiovascular events [1]. - They stabilize **atherosclerotic plaques** and reduce inflammation, playing a critical role in secondary prevention of heart attacks and strokes [1].

Q: What is the primary cause of Common Variable Immunodeficiency (CVID)?

Defective B cell differentiation. ***Defective B cell differentiation*** - CVID is characterized primarily by a failure of **B cells** to differentiate into **plasma cells**, which are responsible for producing antibodies [1]. - This defective differentiation leads to **hypogammaglobulinemia**, or low levels of immunoglobulins [1]. *Absent B cells* - Complete absence of B cells is characteristic of severe combined immunodeficiency (SCID) or X-linked agammaglobulinemia (XLA), not CVID [1]. - In CVID, B cells are typically present, but they are dysfunctional. *Reduced number of B cells* - While some patients with CVID may have reduced B cell numbers, this is not the primary or defining defect. - The key issue is the inability of existing B cells to mature and produce antibodies effectively. *Defective B cell function* - While B cell function is indeed defective in CVID, the root cause of this malfunction is specifically the **failure of differentiation** into mature plasma cells. - The B cells are unable to perform their primary function of antibody production due to this arrest in their development.

Q: Which of the following is an example of the transfer of drug resistance by conjugation?

E coli to streptomycin. **E coli to streptomycin** - The transfer of **streptomycin resistance** in *E. coli* is a classic example of **conjugation**, mediated by **transferable R-plasmids**. - **Conjugation** involves direct cell-to-cell contact and the transfer of genetic material via a **pilus**, allowing for efficient spread of resistance genes. *Staphylococci to rifampicin* - **Rifampicin resistance** in *Staphylococci* (e.g., MRSA) primarily results from **chromosomal mutations** in the *rpoB* gene, which alters the drug's binding site. - This type of resistance usually arises through **spontaneous mutation and selection**, rather than active transfer via conjugation. *Pneumococcus to penicillin G* - **Penicillin resistance** in *Pneumococcus* (e.g., **PEN-R *S. pneumoniae***) is often due to alterations in **penicillin-binding proteins (PBPs)**, acquired through **transformation**. - Transformation involves the uptake of **naked DNA** from the environment, not direct cell-to-cell contact as in conjugation. *M tuberculosis to antitubercular drugs* - **Drug resistance** in *Mycobacterium tuberculosis* to antitubercular drugs (such as isoniazid and rifampicin) is predominantly mediated by **chromosomal mutations**. - These mutations occur within genes encoding drug targets or drug-activating enzymes, leading to altered drug sensitivity.

Q: Which of the following statements about the VDRL test is LEAST accurate?

VDRL is a treponemal-specific test with high specificity. ***VDRL is a treponemal-specific test with high specificity*** - This statement is inaccurate because the **VDRL test** is a **non-treponemal** test, meaning it detects antibodies to cardiolipin, a lipid released from damaged host cells, rather than directly detecting antibodies to *Treponema pallidum*. - Non-treponemal tests like VDRL are known for their potential to produce **false-positive results** due to various conditions. *VDRL is a non-treponemal test and can give false positive results* - The **VDRL test** is indeed a **non-treponemal** test, detecting antibodies against cardiolipin, cholesterol, and lecithin. - Since it detects host-derived antibodies rather than specific *Treponema pallidum* antibodies, it is prone to **false-positive results** in conditions like autoimmune diseases, infections, and pregnancy. *RPR is better than VDRL for monitoring drug therapy* - Both **RPR (Rapid Plasma Reagin)** and VDRL are used to monitor response to therapy in syphilis, but **RPR is sometimes preferred** due to its ease of use (no need for a microscope), stability of reagents, and clearer macroscopic end-point. - The **titers of both VDRL and RPR typically decrease** after successful treatment, indicating a good response to therapy. *VDRL is a slide flocculation test for syphilis* - The **VDRL test** is a **flocculation test** where cardiolipin antigen mixed with a patient's serum (containing reagin antibodies) results in visible clumping or flocculation under a microscope. - It is used as a screening test for **syphilis**, caused by *Treponema pallidum*.

Q: Which bacteria can grow even in the presence of antiseptics?

Pseudomonas. ***Pseudomonas*** - **Pseudomonas aeruginosa** is unique among common bacteria in its ability to not just survive but actually **grow in the presence of antiseptics**. - It can multiply in **quaternary ammonium compounds**, **chlorhexidine solutions**, and even **distilled water** due to minimal nutritional requirements. - Resistance mechanisms include **efflux pumps**, **biofilm formation**, and **low outer membrane permeability** that exclude many antiseptic agents. - This characteristic makes it a notorious cause of **hospital-acquired infections** and contaminant of disinfectant solutions. *Staphylococcus* - While some strains like **MRSA (methicillin-resistant Staphylococcus aureus)** are resistant to many antibiotics, they are generally **susceptible to common antiseptics**. - Standard antiseptics like alcohols, iodophors, and chlorhexidine effectively kill Staphylococcus species. *Streptococcus* - **Streptococcus species** are generally **susceptible to most common antiseptics and disinfectants**. - They are known for causing infections like strep throat and cellulitis but do not exhibit antiseptic resistance. *E. coli* - **Escherichia coli** is typically **susceptible to standard antiseptic agents**. - While some strains can be antibiotic-resistant, their resistance mechanisms do not generally extend to antiseptics, unlike **Pseudomonas**.

Q: Which type of anemia is most commonly characterized by marked poikilocytosis and anisocytosis on peripheral blood smear?

Iron deficiency anemia. ***Iron deficiency anaemia*** - Characterized by **poikilocytosis** (abnormal shapes) and **anisocytosis** (variation in red blood cell sizes), which are common findings in iron deficiency [1]. - Typically results in **microcytic hypochromic anemia** [1], distinguishing it from other types of anemia. *Nutritional deficiency anaemia* - May present with various blood cell morphology but does not specifically exhibit **poikilocytosis** and **anisocytosis** characteristic of iron deficiency anemia. - Usually includes deficiencies like **vitamin B12** or **folate**, which result in **macrocytic anemia** instead. *Megaloblastic anaemia* - Primarily caused by deficiency of **vitamin B12** or **folate**, leading to large, immature red blood cells (megaloblasts) rather than varied shapes and sizes. - Associated with **hypersegmented neutrophils** in the blood smear, which differentiates it from iron deficiency anemia. *Thalassemia* - Characterized by **microcytic hypochromic red blood cells** and often involves **target cells** rather than generalized poikilocytosis and anisocytosis. - Typically presents with **hemolytic anemia** but does not show the same variability in cell shapes and sizes as seen in iron deficiency anemia. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591.

Question 1

Vaccine derived polio virus outbreaks are due to?

Accepted Answer

Type-2 poliovirus

Answer

Type-3 poliovirus

Answer

Type-1 poliovirus

Answer

All types of poliovirus

Question 2

Which area is typically not involved in a chickenpox rash?

Accepted Answer

Palms and soles

Answer

Trunk

Answer

Axilla

Answer

Back

Question 3

Which of the following is not a complication of maxillary sinus lavage and insufflation?

Accepted Answer

Facial nerve injury

Answer

Orbital injury

Answer

Epistaxis

Answer

Air embolism

Question 4

What is the treatment of choice for ethmoidal polyps?

Accepted Answer

Functional Endoscopic sinus surgery with polypectomy

Answer

Intranasal ethmoidectomy

Answer

Transantral ethmoidectomy

Answer

Extranasal ethmoidectomy

Question 5

Which of the following is not recommended for patients with coronary artery disease?

Accepted Answer

Vitamin E

Answer

Potassium

Answer

Statins

Answer

Daily exercise

Question 6

What is the primary cause of Common Variable Immunodeficiency (CVID)?

Accepted Answer

Defective B cell differentiation

Answer

Defective B cell function

Answer

Absent B cells

Answer

Reduced number of B cells

Question 7

Which of the following is an example of the transfer of drug resistance by conjugation?

Accepted Answer

E coli to streptomycin

Answer

Staphylococci to rifampicin

Answer

Pneumococcus to penicillin G

Answer

M tuberculosis to antitubercular drugs

Question 8

Which of the following statements about the VDRL test is LEAST accurate?

Accepted Answer

VDRL is a treponemal-specific test with high specificity

Answer

RPR is better than VDRL for monitoring drug therapy

Answer

VDRL is a non-treponemal test and can give false positive results

Answer

VDRL is a slide flocculation test for syphilis

Question 9

Which bacteria can grow even in the presence of antiseptics?

Accepted Answer

Pseudomonas

Answer

Staphylococcus

Answer

Streptococcus

Answer

E. coli

Question 10

Which type of anemia is most commonly characterized by marked poikilocytosis and anisocytosis on peripheral blood smear?

Accepted Answer

Iron deficiency anemia

Answer

Megaloblastic anemia

Answer

Nutritional anemia

Answer

Thalassemia

NEET-PG 2015

Community Medicine

Dermatology

ENT

Internal Medicine

Microbiology

Pathology