Biochemistry
1 questionsCystatin C levels are used for
NEET-PG 2013 - Biochemistry NEET-PG Practice Questions and MCQs
Question 971: Cystatin C levels are used for
- A. Detecting UTI
- B. Estimating GFR (Correct Answer)
- C. Screening for Renal Ca
- D. Estimating difference between CRF and ARF
Explanation: ***Estimating GFR*** - **Cystatin C** is a **proteinase inhibitor** produced by all nucleated cells at a constant rate, and its level in the blood is inversely related to the **glomerular filtration rate (GFR)**. - Unlike **creatinine**, Cystatin C levels are less affected by **muscle mass, diet, or inflammation**, making it a more reliable marker for early and subtle changes in GFR, especially in certain populations. *Detecting UTI* - **Urinary tract infections (UTIs)** are primarily detected through **urinalysis** (presence of **leukocytes, nitrites**, and **bacteria**) and **urine culture**. - **Cystatin C** is a serum marker for renal function and has no direct role in detecting the presence of bacterial infection in the urinary tract. *Estimating difference between CRF and ARF* - Differentiating between **chronic renal failure (CRF)** and **acute renal failure (ARF)** typically involves assessing the **chronicity of symptoms**, trend in **creatinine levels**, and **kidney size** and **echogenicity** on ultrasound. - While Cystatin C can reflect current GFR, it doesn't inherently provide discriminatory power between acute and chronic processes without serial measurements or additional clinical context. *Screening for Renal Ca* - **Renal cell carcinoma (RCC)** screening is primarily done using **imaging techniques** like **ultrasonography, CT, or MRI**, especially in individuals with risk factors or symptoms like **hematuria**. - **Cystatin C** is a marker of kidney function and does not serve as a tumor marker for renal cancer.
Internal Medicine
5 questionsWhich of the following statements is true regarding the diagnostic criteria for Chronic Obstructive Pulmonary Disease (COPD)?
In which condition is Cepacia syndrome most commonly associated?
What is the most common cause of lobar consolidation?
Which of the following is not a clinical feature of Bronchiectasis?
The physiological marker of the last stage of acute asthma is
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 971: Which of the following statements is true regarding the diagnostic criteria for Chronic Obstructive Pulmonary Disease (COPD)?
- A. A post-bronchodilator FEV1/FVC ratio above the threshold indicates normal lung function.
- B. A post-bronchodilator FEV1/FVC ratio below the threshold indicates airflow limitation. (Correct Answer)
- C. Residual Volume (RV) is normal.
- D. Total Lung Capacity (TLC) is decreased.
Explanation: ***A post-bronchodilator FEV1/FVC ratio below the threshold indicates airflow limitation.*** [1] - This is the **hallmark diagnostic criterion** for COPD, confirming persistent **airflow obstruction** that is not fully reversible. [1] - The threshold typically used is **< 0.70** or below the **fifth percentile** of the lower limit of normal (LLN). *A post-bronchodilator FEV1/FVC ratio above the threshold indicates normal lung function.* - An FEV1/FVC ratio **above the threshold** indicates the absence of significant **airflow obstruction**, but does not automatically guarantee normal lung function as other parameters like **FEV1** could be affected. - This measurement would suggest a **restrictive lung disease** or **normal lung function**, depending on other spirometry values. *Residual Volume (RV) is normal.* - In COPD, **air trapping** due to airflow obstruction leads to an **increased Residual Volume (RV)**, not a normal RV. - An elevated RV reflects **hyperinflation** of the lungs, a characteristic feature of emphysema and chronic bronchitis. *Total Lung Capacity (TLC) is decreased.* - COPD is characterized by **hyperinflation**, which typically results in an **increased Total Lung Capacity (TLC)** as the lungs become more distended. - A **decreased TLC** would be indicative of a **restrictive lung disease**, which is different from obstructive patterns seen in COPD.
Question 972: In which condition is Cepacia syndrome most commonly associated?
- A. Immotile cilia syndrome
- B. Sarcoidosis
- C. Cystic fibrosis (Correct Answer)
- D. Tuberculosis
Explanation: ***Cystic fibrosis*** - **Cepacia syndrome** is a severe and often fatal complication in patients with **cystic fibrosis** caused by infection with bacteria of the *Burkholderia cepacia complex*. - Patients with cystic fibrosis have impaired mucociliary clearance, making them highly susceptible to chronic bacterial infections, including those leading to Cepacia syndrome. *Sarcoidosis* - **Sarcoidosis** is a multisystem inflammatory disease characterized by the formation of **non-caseating granulomas**, primarily affecting the lungs and lymph nodes. - It is not associated with bacterial infections causing Cepacia syndrome. *Tuberculosis* - **Tuberculosis** is caused by *Mycobacterium tuberculosis* and primarily affects the lungs, leading to granuloma formation and tissue destruction. - While it is a chronic bacterial infection, it does not typically lead to or interact with the *Burkholderia cepacia complex* in the way seen in Cepacia syndrome. *Immotile cilia syndrome* - Also known as **primary ciliary dyskinesia**, this condition involves defective ciliary function leading to recurrent respiratory infections and other issues like situs inversus. - Although patients have recurrent respiratory infections, **Cepacia syndrome** is not a characteristic or commonly associated complication.
Question 973: What is the most common cause of lobar consolidation?
- A. Mycoplasma
- B. Chlamydia
- C. Streptococcus (Correct Answer)
- D. Legionella
Explanation: ***Streptococcus*** - **_Streptococcus pneumoniae_** is the **most common bacterial cause** of community-acquired pneumonia, frequently leading to lobar consolidation. [1] - It often presents with classic symptoms such as **sudden onset of fever**, productive cough with **rusty sputum**, and pleuritic chest pain. [1] *Mycoplasma* - **_Mycoplasma pneumoniae_** typically causes **"walking pneumonia"**, characterized by a more indolent course and often presents with **interstitial infiltrates** rather than dense lobar consolidation. - Though common, it is a less frequent cause of true lobar consolidation compared to _Streptococcus pneumoniae_. *Chlamydia* - **_Chlamydia pneumoniae_** causes atypical pneumonia, similar to _Mycoplasma_, presenting with less severe symptoms and **patchy infiltrates** or **interstitial patterns** rather than lobar consolidation. - It is a common cause of **atypical pneumonia** but not the leading cause of lobar consolidation. *Legionella* - **_Legionella pneumophila_** can cause severe pneumonia with consolidation, but it is **less common overall** than pneumococcal pneumonia. [1] - **Legionnaires' disease** is often associated with exposure to contaminated water sources and may present with **gastrointestinal and neurological symptoms** in addition to respiratory manifestations.
Question 974: Which of the following is not a clinical feature of Bronchiectasis?
- A. Hemoptysis
- B. Chest pain
- C. Night sweats (Correct Answer)
- D. Productive cough
Explanation: ***Night sweats*** - While **night sweats** can be present in chronic infections, they are not considered a primary or defining clinical feature directly associated with the pathology of bronchiectasis itself. - They are more commonly linked with systemic conditions like **tuberculosis** or malignancy, which would require alternative diagnostic pathways. *Hemoptysis* - **Hemoptysis** (coughing up blood) is a common and often alarming symptom of bronchiectasis due to the inflammation and damage to the bronchial walls and underlying vasculature [1]. - Blood vessels in damaged airways are prone to rupture, leading to bleeding, which can range from blood-streaked sputum to massive hemorrhage [1]. *Chest pain* - **Chest pain** can occur in bronchiectasis, often related to the chronic cough, pleural inflammation, or musculoskeletal strain from persistent coughing. - It can also be a symptom if there's an associated infection or inflammation extending to the pleura. *Productive cough* - A **chronic productive cough** with significant amounts of purulent sputum is the hallmark symptom of bronchiectasis [1]. - This is due to the impaired mucociliary clearance and chronic infection within the dilated, damaged airways .
Question 975: The physiological marker of the last stage of acute asthma is
- A. Hypocapnia
- B. Hyperoxia
- C. Alkalosis
- D. Increased carbon dioxide levels (Hypercapnia) (Correct Answer)
Explanation: ***Increased carbon dioxide levels (Hypercapnia)*** - In severe, acute asthma, **air trapping** and **muscle fatigue** lead to inadequate ventilation and impaired gas exchange [1]. - This results in a buildup of carbon dioxide in the blood, indicating impending **respiratory failure** and a critical stage of the asthma exacerbation [3]. *Hypocapnia* - **Hypocapnia**, or low blood CO2, is common in the **early stages** of an asthma attack due to **tachypnea** (rapid breathing) in an effort to compensate [1]. - As the condition worsens, the ability to ventilate adequately diminishes, leading to CO2 retention [3]. *Hyperoxia* - **Hyperoxia** means abnormally high levels of oxygen in the blood, which is generally not a physiological marker of acute asthma. - Patients with acute asthma typically experience **hypoxemia** (low oxygen levels) due to ventilation-perfusion mismatch [1]. *Alkalosis* - **Respiratory alkalosis** (high pH due to low CO2) can occur in the early stages as patients **hyperventilate**. - However, in the late stages, as CO2 builds up (**hypercapnia**), the patient shifts towards **respiratory acidosis** (low pH), which is a sign of severe compromise [2], [3].
Microbiology
1 questionsEmpyema thoracis is most commonly caused by which organism
NEET-PG 2013 - Microbiology NEET-PG Practice Questions and MCQs
Question 971: Empyema thoracis is most commonly caused by which organism
- A. Streptococcus pneumoniae (Correct Answer)
- B. Pseudomonas
- C. Staphylococcus aureus
- D. Mycobacterium
Explanation: ***Streptococcus pneumoniae*** - This is the **most common cause of empyema thoracis**, accounting for **40-70% of all cases** in most published series - It is the leading cause of **community-acquired pneumonia** that progresses to parapneumonic effusion and empyema - The pneumococcal infection leads to **inflammatory exudation** into the pleural space, which can progress through exudative, fibrinopurulent, and organizing phases to form frank empyema - Remains the most frequent causative organism across all age groups in community-acquired empyema *Staphylococcus aureus* - An important but **less common cause** of empyema, accounting for approximately 10-20% of cases - More frequently seen in **specific clinical contexts**: post-influenza pneumonia, hospital-acquired infections, hematogenous spread, and pediatric empyema - Causes **severe, necrotizing infections** with abscess formation and is associated with higher morbidity - While clinically significant, it is **not the most common** overall cause *Pseudomonas* - *Pseudomonas aeruginosa* is primarily associated with **nosocomial empyema** in hospitalized patients - Risk factors include **ventilator-associated pneumonia**, immunosuppression, and **cystic fibrosis** - Accounts for a small percentage of empyema cases overall *Mycobacterium* - *Mycobacterium tuberculosis* causes **tuberculous empyema**, a chronic condition with characteristic **thick pleural fluid** and caseous material - Important in regions with high TB prevalence but represents a distinct entity from acute bacterial empyema - Not a common cause of acute pyogenic empyema in most settings
Pharmacology
1 questionsWhat is the drug of choice for most forms of interstitial lung disease?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 971: What is the drug of choice for most forms of interstitial lung disease?
- A. Antibiotics
- B. Bronchodilators
- C. Aspirin
- D. Corticosteroids (Correct Answer)
Explanation: ***Corticosteroids*** - **Corticosteroids** are the **drug of choice** for many forms of **interstitial lung disease (ILD)** due to their potent **anti-inflammatory** and **immunosuppressive properties**, which help reduce lung inflammation and prevent fibrosis. - They are particularly effective in inflammatory ILDs such as **sarcoidosis**, **hypersensitivity pneumonitis**, and some **connective tissue disease-associated ILDs**. *Antibiotics* - **Antibiotics** are primarily used to treat bacterial and other microbial infections and are **not effective** against the **inflammatory and fibrotic processes** characteristic of most ILDs. - They might be used if there's a **secondary bacterial infection** complicating ILD, but not as primary treatment for the ILD itself. *Bronchodilators* - **Bronchodilators** work by relaxing the muscles around the airways, making them wider and easier to breathe through, which is beneficial in conditions like **asthma** or **COPD**. - They are **not primarily used** in ILD as the main problem is **inflammation and scarring of the lung tissue**, not reversible airway constriction. *Aspirin* - **Aspirin** is an **NSAID** with **anti-inflammatory**, **anti-platelet**, and **analgesic properties**, commonly used for pain relief, fever reduction, and cardiovascular protection. - It has **no established role** in the primary treatment of **interstitial lung disease**, as its anti-inflammatory effects are typically insufficient for the severe inflammation seen in ILD.
Physiology
1 questionsWhich of the following is markedly decreased in restrictive lung disease?
NEET-PG 2013 - Physiology NEET-PG Practice Questions and MCQs
Question 971: Which of the following is markedly decreased in restrictive lung disease?
- A. FVC (Correct Answer)
- B. RV
- C. FEV1/FVC
- D. FEV1
Explanation: ***FVC*** - In **restrictive lung disease**, there is a reduction in lung volume due to various causes, leading to a markedly decreased **Forced Vital Capacity (FVC)**. - **FVC** directly measures the total amount of air a person can exhale after a maximal inhalation, which is inherently limited in restrictive conditions. - This is the **hallmark finding** in restrictive lung disease and the most clinically significant decrease. *FEV1* - While **FEV1** (Forced Expiratory Volume in 1 second) is also decreased in restrictive lung disease, its decrease is proportional to the FVC decrease. - A decrease in FEV1 alone is less specific, as it could also indicate obstructive lung disease. - The key is that both FEV1 and FVC decrease together, maintaining a normal or increased ratio. *FEV1/FVC* - The **FEV1/FVC ratio** is typically **normal or even increased** in restrictive lung disease, as both FEV1 and FVC decrease proportionally or FEV1 decreases slightly less. - A decreased FEV1/FVC ratio is characteristic of **obstructive lung disease**, not restrictive. *RV* - **Residual Volume (RV)** is also **decreased** in restrictive lung disease, along with all other lung volumes (TLC, VC, FRC). - However, RV is not measured by standard spirometry and requires body plethysmography or gas dilution techniques. - While RV does decrease, **FVC** is the more clinically significant and readily measurable parameter that is "markedly decreased" and defines restrictive disease on routine pulmonary function testing.
Radiology
1 questionsA chest X-ray shows bilateral lung infiltrates. What is the next best investigation?
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 971: A chest X-ray shows bilateral lung infiltrates. What is the next best investigation?
- A. Sputum examination
- B. CT (Correct Answer)
- C. Bronchoscopy
- D. Echocardiography
Explanation: ***CT*** - A **CT scan (preferably HRCT)** provides a more detailed view of the lung parenchyma, allowing for better characterization of the infiltrates (e.g., location, pattern, presence of nodules, ground-glass opacities, or consolidation). - This detailed imagery is crucial for narrowing down the differential diagnosis and guiding further diagnostic or therapeutic interventions. - **CT is the best next investigation** for characterizing bilateral lung infiltrates seen on chest X-ray. *Sputum examination* - While important for identifying infectious causes, **sputum examination** is often only productive in certain types of pneumonia or infections and might not directly clarify the morphology or distribution of the infiltrates as a CT scan would. - It might be a subsequent step once the nature of the infiltrate is better understood through imaging. *Bronchoscopy* - **Bronchoscopy** is an invasive procedure generally reserved for cases where less invasive methods have failed to yield a diagnosis or when specific findings from imaging (like a CT scan) suggest the need for direct visualization, lavage, or biopsy. - It's not typically the immediate next step after identifying bilateral infiltrates on a chest X-ray. *Echocardiography* - **Echocardiography** is useful for evaluating cardiac causes of bilateral infiltrates (such as pulmonary edema from heart failure). - However, it does not directly visualize or characterize the lung parenchymal infiltrates themselves, making CT more valuable as the next investigation.