Biochemistry
1 questionsWhich of the following is the etiology of Werner syndrome?
NEET-PG 2020 - Biochemistry NEET-PG Practice Questions and MCQs
Question 281: Which of the following is the etiology of Werner syndrome?
- A. Increased length of telomere
- B. Increased advanced glycation end products
- C. Decreased lipid peroxidation
- D. Short telomere with damaged DNA and loss of helicase (Correct Answer)
Explanation: ***Short telomere with damaged DNA and loss of helicase*** - **Werner syndrome** is an **autosomal recessive disorder** characterized by **premature aging** due to mutations in the *WRN* gene, which codes for a **RecQ-type DNA helicase**. - The dysfunctional helicase leads to defects in **DNA replication, repair, and transcription**, resulting in **genomic instability**, **damaged DNA**, and **accelerated telomere attrition** (short telomeres). *Increased length of telomere* - **Increased telomere length** is generally associated with a **reduced rate of cellular aging** and is not characteristic of Werner syndrome or other premature aging disorders. - In most aging processes and syndromes like Werner, **telomeres tend to shorten** over time due to incomplete replication and oxidative stress. *Increased advanced glycation end products* - **Advanced glycation end products (AGEs)** accumulate in various tissues during normal aging and in conditions like diabetes, contributing to vascular and organ damage. - While AGEs play a role in the broader aging process, they are not the primary underlying genetic defect or direct etiology of Werner syndrome, which is a **DNA repair disorder**. *Decreased lipid peroxidation* - **Lipid peroxidation** is a process by which **free radicals** attack lipids, leading to cellular damage and is often associated with oxidative stress and aging. - A **decrease in lipid peroxidation** would generally be considered protective against aging-related damage, which is the opposite of what is seen in Werner syndrome, where there's an accelerated aging phenotype and increased cellular stress.
Community Medicine
1 questionsWhich of the following is classified as a Category A bioterrorism agent?
NEET-PG 2020 - Community Medicine NEET-PG Practice Questions and MCQs
Question 281: Which of the following is classified as a Category A bioterrorism agent?
- A. Clostridium perfringens
- B. NIPAH virus
- C. Bacillus anthracis (Correct Answer)
- D. Coxiella burnetii
Explanation: ***Bacillus anthracis*** - **Anthrax**, caused by *Bacillus anthracis*, is a prime example of a Category A bioterrorism agent due to its high mortality, ease of dissemination, and potential for major public health impact. - Category A agents pose the **greatest threat** to public health and national security. *Clostridium perfringens* - *Clostridium perfringens* is classified as a **Category B bioterrorism agent**. - While it causes **gas gangrene** and food poisoning with moderate severity, it lacks the **high transmissibility** and widespread impact characteristic of Category A agents. *NIPAH virus* - **Nipah virus** is classified as a Category C priority pathogen. - It has the potential for high morbidity and mortality, but its **epidemiological characteristics** (e.g., lower transmissibility than Category A agents) preclude its inclusion in Category A. *Coxiella burnetii* - *Coxiella burnetii*, the causative agent of **Q fever**, is classified as a Category B bioterrorism agent. - Category B agents are moderately easy to disseminate and can cause **moderate morbidity** and low mortality, which is less severe than Category A agents.
Dermatology
1 questionsBaby born with membrane around him at the time of birth. Which of the following conditions is depicted?
NEET-PG 2020 - Dermatology NEET-PG Practice Questions and MCQs
Question 281: Baby born with membrane around him at the time of birth. Which of the following conditions is depicted?
- A. X-linked ichthyosis (steroid sulfatase deficiency)
- B. Generalized hyperkeratosis (thickened skin)
- C. Ichthyosis vulgaris (dry, scaly skin)
- D. Lamellar ichthyosis (collodion membrane at birth) (Correct Answer)
Explanation: ***Lamellar ichthyosis (collodion membrane at birth)*** - This condition is characterized by a "collodion membrane" at birth, which is a **tight, shiny, parchment-like membrane** that covers the entire body. - The membrane typically **sheds within weeks**, revealing underlying scaling and erythema characteristic of lamellar ichthyosis. *X-linked ichthyosis (steroid sulfatase deficiency)* - Marked by **dark brown, adherent scales**, primarily affecting the neck, trunk, and extensor surfaces. - It usually becomes apparent **several weeks or months after birth** and is not typically associated with a collodion membrane. *Generalized hyperkeratosis (thickened skin)* - This is a general term for **thickening of the outermost layer of the epidermis** and is a feature of many ichthyoses, not a specific condition with a "membrane at birth." - It describes a **symptom** rather than a primary diagnosis presenting with a specific birth membrane. *Ichthyosis vulgaris (dry, scaly skin)* - Presents with **fine, white scaling**, most prominent on the extensor surfaces of the limbs, but it **rarely appears at birth**. - It is typically **mild** and often worsens in dry, cold weather, lacking the characteristic "membrane around him" at birth.
Internal Medicine
1 questionsPatient presented with diarrhoea, poor appetite and malabsorption. His duodenal biopsy was taken which showed crypt hyperplasia, villi atrophy and infiltration of CD8+ T cells in the epithelium. What is the likely diagnosis of the patient?
NEET-PG 2020 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 281: Patient presented with diarrhoea, poor appetite and malabsorption. His duodenal biopsy was taken which showed crypt hyperplasia, villi atrophy and infiltration of CD8+ T cells in the epithelium. What is the likely diagnosis of the patient?
- A. Celiac disease (Correct Answer)
- B. Whipple disease
- C. Environmental enteropathy
- D. Pancreatitis
Explanation: ***Celiac disease*** - The combination of **diarrhoea**, **malabsorption**, **villi atrophy**, **crypt hyperplasia**, and **CD8+ T-cell infiltration** in the duodenal epithelium is pathognomonic for celiac disease [1]. - This condition is triggered by **gluten ingestion**, leading to an immune-mediated enteropathy [1], [3]. *Whipple disease* - Characterized by **malabsorption**, fever, arthralgia, and neurological symptoms [2]. - Histologically, it shows **foamy macrophages** containing PAS-positive material (Tropheryma whipplei) in the lamina propria, not primarily CD8+ T-cell infiltration [2]. *Environmental enteropathy* - Also known as tropical enteropathy, it causes **villi atrophy** and malabsorption, particularly in individuals living in areas with poor sanitation. - However, the prominent feature is often a diffuse inflammatory infiltrate, and specific **CD8+ T-cell infiltration** in the epithelium is not as specific as in celiac disease. *Pancreatitis* - Presents with **abdominal pain**, nausea, and vomiting, and can lead to malabsorption due to pancreatic enzyme insufficiency. - Histology of the duodenum would typically be normal, as the pathology primarily involves the **pancreas**, not the duodenal mucosa itself.
Obstetrics and Gynecology
2 questionsWhich of the following cannot be used as Post-coital contraceptive?
A 7-week pregnant lady underwent a chest X-ray by mistake. What is to be done?
NEET-PG 2020 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 281: Which of the following cannot be used as Post-coital contraceptive?
- A. A device that prevents fertilization and implantation (e.g., CuT 200)
- B. A hormonal method that disrupts ovulation (e.g., high-dose estrogens)
- C. A drug primarily used for endometriosis and fibrocystic breast disease (e.g., Danazol) (Correct Answer)
- D. A progesterone receptor blocker used within 72 hours (e.g., RU 486)
Explanation: ***A drug primarily used for endometriosis and fibrocystic breast disease (e.g., Danazol)*** - **Danazol** is an **androgen derivative** primarily used to treat endometriosis and fibrocystic breast disease due to its *anti-estrogenic* and *anti-progestational* effects. - It does not have a primary role as a **post-coital contraceptive** and is not approved for this indication. *A device that prevents fertilization and implantation (e.g., CuT 200)* - The **CuT 200 (copper T intrauterine device)** can be inserted as an **emergency contraceptive** within five days of unprotected intercourse. - It works by causing a **spermicidal effect** within the uterus and preventing implantation if fertilization occurs. *A hormonal method that disrupts ovulation (e.g., high-dose estrogens)* - High-dose **estrogens alone** or in combination with progesterone can be used as **emergency contraception** (e.g., the Yuzpe method). - These hormones disrupt the hormonal cascade necessary for **ovulation** or alter the endometrial lining to prevent implantation. *A progesterone receptor blocker used within 72 hours (e.g., RU 486)* - **RU 486 (Mifepristone)** is a **progesterone receptor blocker** that can be used as an emergency contraceptive within 72 (or sometimes up to 120) hours of unprotected intercourse. - It works by **delaying or inhibiting ovulation** and by altering the endometrium, making it unsuitable for implantation.
Question 282: A 7-week pregnant lady underwent a chest X-ray by mistake. What is to be done?
- A. Terminate the pregnancy immediately due to radiation exposure.
- B. Perform chromosomal testing to assess fetal damage.
- C. Reassure the patient and continue the pregnancy. (Correct Answer)
- D. Conduct prenatal invasive diagnostic tests to evaluate fetal health.
Explanation: **Reassure the patient and continue the pregnancy.** - A single chest X-ray delivers a **negligible dose of radiation (around 0.01 mGy)** to the embryo/fetus, which is significantly below the threshold for causing congenital abnormalities or pregnancy loss. - The **teratogenic threshold** for radiation exposure is generally considered to be around **50-100 mGy**, making a single chest X-ray exposure well within safe limits. *Terminate the pregnancy immediately due to radiation exposure.* - There is **no clinical justification** for pregnancy termination based on a single chest X-ray, as the radiation dose is far too low to cause significant harm. - Such an intervention would be based on **misinformation** and could lead to unnecessary emotional distress and ethical concerns. *Perform chromosomal testing to assess fetal damage.* - Chromosomal testing is **not indicated** for low-dose radiation exposure from a single chest X-ray, as this type of exposure is unlikely to cause chromosomal abnormalities. - The radiation dose is simply too low to inflict the kind of damage that would necessitate such invasive and often risky procedures. *Conduct prenatal invasive diagnostic tests to evaluate fetal health.* - Invasive prenatal diagnostic tests, such as **amniocentesis or chorionic villus sampling**, carry their own risks and are not warranted for a benign exposure like a chest X-ray. - These tests are typically reserved for situations with a much higher established risk of fetal anomalies.
Pharmacology
1 questionsWhat is the first-line drug for post-menopausal osteoporosis?
NEET-PG 2020 - Pharmacology NEET-PG Practice Questions and MCQs
Question 281: What is the first-line drug for post-menopausal osteoporosis?
- A. Raloxifene
- B. Calcitonin
- C. Bisphosphonates (Correct Answer)
- D. Oestrogen
Explanation: **Bisphosphonates** - **Bisphosphonates** are the **first-line therapy** for postmenopausal osteoporosis due to their proven efficacy in reducing the risk of fragility fractures. - They work by **inhibiting osteoclast activity**, thereby reducing bone resorption and increasing bone mineral density. *Raloxifene* - **Raloxifene** is a **selective estrogen receptor modulator (SERM)** that can be used for osteoporosis prevention and treatment, but it is typically a second-line option, especially in women who cannot tolerate bisphosphonates or have an increased risk of breast cancer. - While it has a positive effect on bone density, its fracture-reduction efficacy is not as broad as bisphosphonates (e.g., it reduces vertebral fractures but has less consistent data on non-vertebral fractures). *Calcitonin* - **Calcitonin** is generally reserved for patients who cannot tolerate other therapies or for short-term use in acute vertebral fractures to help with pain relief. - Its efficacy in reducing fracture risk is **less robust** compared to bisphosphonates, and it is not considered a first-line agent. *Oestrogen* - **Estrogen (hormone replacement therapy)** was once a primary treatment but is now generally not recommended as first-line for osteoporosis due to concerns about increased risks of breast cancer, cardiovascular events, and stroke, particularly in older women. - It is typically reserved for women with significant menopausal symptoms for whom other therapies are contraindicated or ineffective, and for the shortest duration possible.
Psychiatry
1 questionsThe most widely used substance causing dependence worldwide is:
NEET-PG 2020 - Psychiatry NEET-PG Practice Questions and MCQs
Question 281: The most widely used substance causing dependence worldwide is:
- A. Cocaine
- B. Cannabis
- C. Amphetamines
- D. Alcohol (Correct Answer)
Explanation: ***Alcohol*** - **Alcohol** is the most widely consumed psychoactive substance globally, leading to a significant burden of dependence and related health issues. - Its widespread availability, social acceptance, and addictive properties contribute to its high rates of dependence across diverse populations. *Cocaine* - While **cocaine** is a powerful and highly addictive stimulant, its use and dependence are not as prevalent globally as alcohol. - The geographical distribution and historical context of cocaine use are more concentrated compared to the ubiquitous nature of alcohol consumption. *Cannabis* - **Cannabis** is one of the most commonly used illicit drugs worldwide, and it can cause dependence, but its overall prevalence of dependence is lower than that of alcohol. - The perception of lower harm and increased legalization in some regions have led to higher rates of use, but alcohol still surpasses it in terms of global dependence rates. *Amphetamines* - **Amphetamines**, including methamphetamine, are potent stimulants known for their high potential for dependence. - However, their global usage and rates of dependence, while significant in certain regions, do not reach the broad societal impact and prevalence seen with alcohol.
Surgery
2 questionsWhich of the following statements is true regarding retrosternal goiters?
A middle-aged man presented with a swelling over the neck since childhood. The swelling is irregular and involves large nerves and their branches. Most probable diagnosis is:
NEET-PG 2020 - Surgery NEET-PG Practice Questions and MCQs
Question 281: Which of the following statements is true regarding retrosternal goiters?
- A. Majority of the goiters derive their blood supply from mediastinal vessels
- B. Sternal incision is required in all cases
- C. Surgery is performed only if the patient is symptomatic
- D. Most retrosternal goiters can be removed through a neck incision (Correct Answer)
Explanation: ***Most retrosternal goiters can be removed through a neck incision*** - The majority of retrosternal goiters, even those extending significantly into the mediastinum, originate from cervical thyroid tissue and can be safely delivered through a standard **cervical incision**. - While careful dissection is required to free the mass from surrounding mediastinal structures, **rarely is a sternotomy** or thoracotomy needed. *Majority of the goiters derive their blood supply from mediastinal vessels* - Retrosternal goiters typically maintain their primary **blood supply from the superior and inferior thyroid arteries**, which are cervical vessels. - While some small accessory vessels might come from the mediastinum, the bulk of the vascularization remains **cervical in origin**. *Sternal incision is required in all cases* - A **sternal incision (sternotomy)** is required in only a small percentage (less than 10%) of retrosternal goiter cases, usually for very large, highly adherent, or recurrent goiters, or suspicion of malignancy. - The goal is always to avoid a sternotomy due to its increased morbidity and recovery time compared to a cervical approach. *Surgery is performed only if the patient is symptomatic* - Surgery for retrosternal goiters is often recommended even in **asymptomatic patients** due to the risk of future complications, such as airway compromise, superior vena cava syndrome, or malignancy. - The potential for growth and compression of vital mediastinal structures makes prophylactic surgery a common consideration.
Question 282: A middle-aged man presented with a swelling over the neck since childhood. The swelling is irregular and involves large nerves and their branches. Most probable diagnosis is:
- A. Toxic nodular goitre
- B. Plexiform neurofibroma (Correct Answer)
- C. Lymphangioma
- D. Vasculitis
Explanation: ***Plexiform neurofibroma*** - This condition presents as an **irregular swelling** evident since childhood, which is characteristic of the slow growth associated with **plexiform neurofibromas**. - Its involvement of **large nerves and their branches** is a hallmark feature, distinguishing it from other neck masses. *Toxic nodular goitre* - This would present primarily as a **thyroid swelling** and is typically associated with symptoms of **hyperthyroidism**, which are not mentioned. - It does not involve **peripheral nerves** in the manner described. *Lymphangioma* - Lymphangiomas are **benign lymphatic malformations** that typically present as soft, compressible masses. - While they can occur in the neck and be present from childhood, they do not specifically involve or originate from **nerve branches**. *Vasculitis* - Vasculitis is an **inflammation of blood vessels**, which can cause a variety of symptoms including pain, skin lesions, and organ dysfunction. - It does not present as a localized, irregular neck swelling involving **nerve branches** with a history since childhood.