Biochemistry
1 questionsTrue statement about vitamin K is?
NEET-PG 2018 - Biochemistry NEET-PG Practice Questions and MCQs
Question 181: True statement about vitamin K is?
- A. Vitamin K is needed for action of clotting factor 8
- B. Vitamin K deficiency leads to DVT
- C. Vitamin K is water soluble
- D. Vitamin K affects bone health by activating proteins that bind calcium (Correct Answer)
Explanation: ***Vitamin K affects bone health by activating proteins that bind calcium*** - Vitamin K plays a crucial role in **osteocalcin activation**, a protein essential for integrating calcium into the bone matrix. - This activation process involves **gamma-carboxylation of glutamic acid residues** on osteocalcin, allowing it to bind calcium and strengthen bone. *Vitamin K is needed for action of clotting factor 8* - Vitamin K is essential for the activation of **clotting factors II, VII, IX, and X**, as well as proteins C and S, through gamma-carboxylation. - **Factor VIII** (antihemophilic factor A) is not directly dependent on vitamin K for its activation. *Vitamin K deficiency leads to DVT* - Vitamin K deficiency primarily leads to **impaired blood clotting** and an increased risk of bleeding, not DVT. - DVT (deep vein thrombosis) is typically associated with **hypercoagulable states**, venous stasis, or endothelial injury. *Vitamin K is water soluble* - Vitamin K is a **fat-soluble vitamin**, meaning it is absorbed with fats in the diet and stored in the body's fatty tissues and liver. - Water-soluble vitamins include **B vitamins and vitamin C**, which are not stored to the same extent and are excreted in urine.
Community Medicine
1 questionsThe online software used to monitor TB control program under RNTCP is:
NEET-PG 2018 - Community Medicine NEET-PG Practice Questions and MCQs
Question 181: The online software used to monitor TB control program under RNTCP is:
- A. NIRBHAI
- B. NIKSHAY (Correct Answer)
- C. e-DOTS
- D. NISCHAY
Explanation: ***Correct Answer: NIKSHAY*** - **NIKSHAY** is the official **web-based patient management system** for monitoring the TB control program under the **Revised National Tuberculosis Control Programme (RNTCP)**, now known as the National Tuberculosis Elimination Programme (NTEP) - It serves as a comprehensive platform for **real-time case notification, treatment monitoring, and tracking of patient outcomes** - Enables **digital recording** of TB patient details, treatment regimens, and follow-up information across India *Incorrect: NIRBHAI* - This is not a recognized software platform associated with RNTCP or TB control monitoring - No official government health program uses this name for TB surveillance *Incorrect: e-DOTS* - While **DOTS (Directly Observed Treatment, Short-course)** is the core treatment strategy for TB, e-DOTS is not the comprehensive online monitoring software - e-DOTS may refer to electronic recording of DOTS adherence, but **NIKSHAY** is the overarching national platform *Incorrect: NISCHAY* - This is not a recognized software platform for RNTCP monitoring - Does not correspond to any official TB control initiative in India
Internal Medicine
3 questionsAll of the following characteristic patterns seen in Brown-Sequard syndrome; except:-
Falsely elevated ankle brachial index is used for evaluation of?
A newborn male baby presents with congestive heart failure. On examination, there are enlarged fontanelles, a loud cranial bruit, and the following radiological finding. What is the most likely diagnosis?
NEET-PG 2018 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 181: All of the following characteristic patterns seen in Brown-Sequard syndrome; except:-
- A. Contralateral loss of pain and temperature
- B. Ipsilateral weakness
- C. Ipsilateral loss of position and vibration
- D. Ipsilateral loss of pain and temperature (Correct Answer)
Explanation: ***Ipsilateral loss of pain and temperature*** - Brown-Sequard syndrome results from **hemitransverse spinal cord lesion**, leading to distinct sensory and motor deficits on only one side of the body [1]. - Pain and temperature pathways (spinothalamic tracts) **decussate (cross over)** in the spinal cord upon entry, so a lesion on one side causes **contralateral** loss of these sensations [2]. *Contralateral loss of pain and temperature* - This is a **characteristic finding** in Brown-Sequard syndrome, as the spinothalamic tracts (carrying pain and temperature) cross over at the level of the spinal cord [2]. - A lesion on one side of the spinal cord therefore results in the loss of these sensations on the **opposite side of the body below the level of the lesion** [1]. *Ipsilateral weakness* - This is a **characteristic finding** in Brown-Sequard syndrome due to the involvement of the **corticospinal tracts** (responsible for motor function) [1]. - These tracts primarily descend **uncrossed** in the spinal cord, so a lesion on one side causes weakness on the **same side of the body below the level of the lesion**. *Ipsilateral loss of position and vibration* - This is a **characteristic finding** in Brown-Sequard syndrome because the **dorsal columns** (medial lemniscal pathway), responsible for fine touch, proprioception, and vibration, ascend **ipsilaterally (uncrossed)** in the spinal cord [2]. - A lesion on one side of the spinal cord therefore results in the loss of these sensations on the **same side of the body below the level of the lesion** [1].
Question 182: Falsely elevated ankle brachial index is used for evaluation of?
- A. Deep vein thrombosis
- B. Acute limb ischemia
- C. Calcified vessels (Correct Answer)
- D. Chronic venous insufficiency
Explanation: A falsely elevated **ankle-brachial index (ABI)**, often >1.3, indicates that the **ankle arteries are non-compressible** due to calcification [1]. This calcification is common in conditions like **diabetes** and **end-stage renal disease**, where the vessels become stiff and resist compression, leading to inaccurate pressure readings [1].
Question 183: A newborn male baby presents with congestive heart failure. On examination, there are enlarged fontanelles, a loud cranial bruit, and the following radiological finding. What is the most likely diagnosis?
- A. Pneumocephalus
- B. Crouzon syndrome
- C. Dandy walker syndrome
- D. Vein of Galen malformation (Correct Answer)
Explanation: ***Vein of Galen malformation*** - The imaging displays a massively dilated **vein of Galen**, indicating a **Vein of Galen malformation (VOGM)**. - VOGM creates a large **arteriovenous shunt**, leading to high-output **congestive heart failure** and often presenting with prominent **cranial bruits** and **macrocephaly** (enlarged fontanelles). *Pneumocephalus* - This condition involves the presence of **air within the intracranial cavity**, commonly due to trauma, surgery, or infection. - It would not explain the **congestive heart failure** or the vascular malformation seen on the imaging. *Crouzon syndrome* - This is a form of **craniosynostosis** characterized by abnormalities in skull and facial bone development, including **midfacial hypoplasia** and **proptosis**. - While it can involve enlarged fontanelles due to hydrocephalus, it does not typically cause **congestive heart failure** or a **cranial bruit** from a vascular malformation. *Dandy-Walker syndrome* - This congenital brain malformation involves agenesis or hypoplasia of the **cerebellar vermis** and cystic dilation of the **fourth ventricle**, often leading to hydrocephalus. - While it can cause enlarged fontanelles, it does not typically lead to **congestive heart failure** or a **cranial bruit**, nor does it present with the characteristic vascular lesion seen in the image.
Obstetrics and Gynecology
1 questionsA 16-year-old girl comes to you with primary amenorrhea; on evaluation there is absent breast development, she has a normal stature, her FSH and LH levels are found to be high and she has a karyotype of 46XX. What is the probable diagnosis?
NEET-PG 2018 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 181: A 16-year-old girl comes to you with primary amenorrhea; on evaluation there is absent breast development, she has a normal stature, her FSH and LH levels are found to be high and she has a karyotype of 46XX. What is the probable diagnosis?
- A. Testicular feminizing syndrome
- B. Turner syndrome
- C. Kallmann syndrome
- D. Gonadal dysgenesis (Correct Answer)
Explanation: ***Gonadal dysgenesis*** - **Primary amenorrhea** with **absent breast development** and **high FSH/LH** (hypergonadotropic hypogonadism) in a **46,XX individual** with **normal stature** points to **46,XX gonadal dysgenesis** (pure gonadal dysgenesis). - In this condition, the gonads fail to develop properly despite a normal female karyotype, leading to non-functional streak ovaries that fail to produce estrogen, hence the lack of secondary sexual characteristics and elevated gonadotropins due to lack of negative feedback. - Unlike Turner syndrome, patients have normal stature and a normal 46,XX karyotype. *Testicular feminizing syndrome* - Individuals with **complete androgen insensitivity syndrome (CAIS)**, formerly called testicular feminizing syndrome, have a **46,XY karyotype** and develop external female characteristics due to complete androgen resistance. - They present with **primary amenorrhea** but typically have **well-developed breasts** (from peripheral aromatization of testosterone to estrogen) and a blind-ending vagina, which contradicts the absent breast development in this case. *Turner syndrome* - Characterized by a **45,X karyotype** (or variants with mosaicism) and typically presents with **short stature**, primary amenorrhea, and gonadal dysgenesis. - While it causes **primary amenorrhea** and **absent breast development** with high FSH/LH, the **normal stature** and **46,XX karyotype** in this patient rule out Turner syndrome. *Kallmann syndrome* - This condition is characterized by **hypogonadotropic hypogonadism** associated with **anosmia or hyposmia** due to defective GnRH secretion. - Patients present with **low FSH and LH levels**, which contradicts the **high gonadotropin levels** seen in this case.
Pathology
2 questionsWhich of the following is true about factor V leiden mutation?
Which of the following is the most common epithelial tumor of the stomach?
NEET-PG 2018 - Pathology NEET-PG Practice Questions and MCQs
Question 181: Which of the following is true about factor V leiden mutation?
- A. Increased bleeding tendency
- B. Factor V becomes resistant to cleavage by protein C (Correct Answer)
- C. Deficiency of factor V
- D. Arginine to glutamine substitution
Explanation: **Factor V becomes resistant to cleavage by protein C** - The **Factor V Leiden mutation** involves a substitution in the Factor V gene, rendering the **activated Factor V (FVa)** resistant to inactivation by **activated protein C (APC)** [1]. - This resistance leads to prolonged activity of FVa, which is a cofactor in the formation of thrombin, thereby increasing the risk of **thrombosis** [1]. *Increased bleeding tendency* - The Factor V Leiden mutation leads to a **hypercoagulable state**, which means an **increased tendency to form blood clots**, not an increased bleeding tendency [1]. - Bleeding disorders are typically associated with deficiencies or dysfunctions in clotting factors or platelets that impair clot formation. *Deficiency of factor V* - The Factor V Leiden mutation is a **gain-of-function mutation** that results in a modified, more active Factor V, not a deficiency of Factor V [1]. - Deficiency of Factor V (known as **parahemophilia**) is a rare bleeding disorder. *Arginine to glycine substitution* - The Factor V Leiden mutation specifically involves a single nucleotide polymorphism leading to an **arginine to glutamine substitution at position 506** (Arg506Gln) in the Factor V protein [1]. - This specific amino acid change alters the cleavage site for activated protein C, making it less effective at inactivating Factor V [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 133-134.
Question 182: Which of the following is the most common epithelial tumor of the stomach?
- A. Gastric adenocarcinoma (Correct Answer)
- B. GIST
- C. Sarcoma
- D. Carcinoid tumor
Explanation: ***Gastric adenocarcinoma*** - This is the **most common** malignant epithelial tumor of the stomach, accounting for over 90% of all gastric cancers [1], [2]. - It arises from the **glandular epithelial cells** lining the stomach [1]. *GIST* - **Gastrointestinal Stromal Tumors (GISTs)** are mesenchymal tumors, originating from the interstitial cells of Cajal, not epithelial cells [2]. - While they are common **non-epithelial** tumors of the stomach, they are far less frequent than gastric adenocarcinoma [2]. *Sarcoma* - **Sarcomas** are rare **mesenchymal tumors** of the stomach, arising from connective tissues like muscle or fat, not epithelial cells. - They constitute a very small percentage of gastric malignancies. *Carcinoid tumor* - **Carcinoid tumors** are **neuroendocrine tumors** that originate from enterochromaffin-like cells in the stomach. - While they are epithelial in origin, they are much less common than gastric adenocarcinoma. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, p. 779. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 354-355.
Pharmacology
1 questionsMechanism of action of d-tubocurarine is:
NEET-PG 2018 - Pharmacology NEET-PG Practice Questions and MCQs
Question 181: Mechanism of action of d-tubocurarine is:
- A. Competitive, nondepolarizing block at the Nm cholinergic receptor (Correct Answer)
- B. Noncompetitive, depolarizing block at the Nm cholinergic receptor
- C. Non-competitive, nondepolarizing block at the Nm cholinergic receptor
- D. Competitive, depolarizing block at the Nm cholinergic receptor
Explanation: ***Competitive, nondepolarizing block at the Nm cholinergic receptor*** - **d-tubocurarine** acts as a **competitive antagonist** at the **nicotinic muscle (Nm) cholinergic receptors** on the motor endplate. - It competes with **acetylcholine (ACh)** for binding sites, preventing ACh from activating the receptor and causing **muscle paralysis** without depolarization. *Noncompetitive, depolarizing block at the Nm cholinergic receptor* - This describes the mechanism of action of **depolarizing neuromuscular blockers** like **succinylcholine**, which first *depolarize* the motor endplate before causing paralysis. - d-tubocurarine does not cause initial depolarization; it directly blocks the receptor. *Non-competitive, nondepolarizing block at the Nm cholinergic receptor* - While d-tubocurarine is **nondepolarizing**, it is a **competitive antagonist**, not a non-competitive one. - A non-competitive block would involve binding to a different site on the receptor or an associated ion channel, altering receptor function indirectly. *Competitive, depolarizing block at the Nm cholinergic receptor* - This option incorrectly combines the concepts, as **depolarizing blockers** like succinylcholine act initially by **depolarizing** the endplate, whereas d-tubocurarine is purely a **nondepolarizing** agent. - The "competitive" aspect would be true for the binding of ACh to its site on a depolarizing agent, but the effect of d-tubocurarine is simply to block, not depolarize.
Surgery
1 questionsHigh tracheostomy is done in:-
NEET-PG 2018 - Surgery NEET-PG Practice Questions and MCQs
Question 181: High tracheostomy is done in:-
- A. Vocal cord palsy
- B. Laryngeal carcinoma (Correct Answer)
- C. Subglottic stenosis
- D. Laryngomalacia
Explanation: ***Laryngeal carcinoma*** - A high tracheostomy, often performed above the second tracheal ring, is indicated in **laryngeal carcinoma** to bypass the obstruction caused by the tumor and ensure a clear airway. - This position provides a more superior opening, which can be crucial when the lower trachea is needed for potential surgical resection or reconstruction, particularly in cases involving extensive laryngeal involvement. *Vocal cord palsy* - **Vocal cord palsy** primarily affects phonation and can cause aspiration, but it typically does not cause acute or severe enough airway obstruction to warrant an emergency tracheostomy. - Airway management for vocal cord palsy often involves voice therapy, glottic augmentation, or arytenoid adduction, rather than high tracheostomy. *Subglottic stenosis* - **Subglottic stenosis** involves narrowing below the vocal cords and usually requires a tracheostomy that is placed **below the level of the stenosis** to bypass the obstruction, often necessitating a low or standard tracheostomy. - A high tracheostomy might be within or too close to the stenotic segment, making it ineffective or surgically challenging. *Laryngomalacia* - **Laryngomalacia** is a congenital condition where the larynx collapses inward during inspiration, causing stridor, most commonly resolving spontaneously by 18-24 months. - Tracheostomy is reserved for severe cases with significant respiratory distress or failure to thrive, and the placement is usually standard or low to ensure bypass of the floppy laryngeal tissues, not typically a high tracheostomy.