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 NOT done in:-
NEET-PG 2018 - Surgery NEET-PG Practice Questions and MCQs
Question 181: High tracheostomy is NOT done in:-
- A. Vocal cord palsy
- B. Laryngeal carcinoma (Correct Answer)
- C. Subglottic stenosis
- D. Laryngomalacia
Explanation: ***Laryngeal carcinoma*** - High tracheostomy is **contraindicated** in laryngeal carcinoma due to risk of **stomal recurrence** and tumor seeding at the tracheostomy site. - It can contaminate the **surgical field** and compromise oncological principles, making future surgical resection more complex. *Laryngomalacia* - High tracheostomy **is indicated** in severe laryngomalacia when there is significant **respiratory distress** or failure to thrive. - It bypasses the **collapsing supraglottic structures** and provides a secure airway above the level of obstruction. *Vocal cord palsy* - High tracheostomy **may be performed** in bilateral vocal cord palsy causing severe **airway obstruction** and stridor. - It provides immediate airway relief while preserving options for future **vocal cord procedures** or reinnervation surgeries. *Subglottic stenosis* - High tracheostomy **is appropriate** in subglottic stenosis as it places the stoma **above the level of stenosis**. - It allows for **staged surgical repair** of the stenotic segment while maintaining airway patency during reconstruction procedures.