INI-CET 2023 Practice Questions

Q: An ICU patient is suffering from Rhinovirus infection. How do we treat the patient?

Supportive care only. ***Supportive care only*** - **Rhinovirus** is a common cause of the **common cold**, and there is no specific antiviral treatment available for it. [1] - Management focuses on alleviating symptoms such as fever, congestion, and cough to ensure patient comfort and prevent secondary complications, especially in an ICU setting. *Piperacillin + Tazobactam + Azithromycin* - This combination is a broad-spectrum antibiotic regimen (piperacillin/tazobactam is an extended-spectrum penicillin, and azithromycin is a macrolide) targeting bacterial infections. [2] - **Rhinovirus is a virus**, and antibiotics are ineffective against viral infections, making this an inappropriate treatment. *Clarithromycin* - **Clarithromycin** is a macrolide antibiotic primarily used to treat bacterial infections, such as respiratory tract infections caused by **atypical bacteria** or community-acquired pneumonia. [2] - It has no activity against **Rhinovirus**, a common cold virus. *Cephalosporin + Ganciclovir* - **Cephalosporins** are a class of beta-lactam antibiotics used for various bacterial infections. [2] - **Ganciclovir** is an antiviral agent specifically used to treat **cytomegalovirus (CMV)** infections, not Rhinovirus.

Q: CD 40 marker is absent in the person. Which of the following would be seen?

Impaired B cell function. ***Impaired B cell function*** - The **CD40 receptor** on B cells is crucial for receiving co-stimulatory signals from **CD40 ligand (CD40L)**, primarily expressed on activated T cells. - Absence of CD40 on B cells prevents proper **T-cell dependent antibody class switching** and germinal center formation, leading to impaired B cell activation, immunoglobulin production, and immune responses. - This condition is seen in **Hyper-IgM Syndrome Type 3** (very rare autosomal recessive disorder). *Impaired Macrophage function* - While macrophages express CD40, its absence would primarily affect their ability to be fully activated by T cells and present antigens, but the most direct and profound impact of absent CD40 is on B cells themselves. - Macrophages have other activation pathways not directly dependent on CD40. *Impaired NK cell function* - **Natural killer (NK) cells** primarily recognize and kill target cells lacking MHC class I molecules or those expressing activating ligands, independent of CD40 signaling. - NK cell function is not directly regulated by the CD40-CD40L interaction. *Impaired T cell function* - While **T cells express CD40L** (the ligand for CD40), the question specifies the absence of the **CD40 marker** itself, which is expressed on B cells, not T cells. - T cell function involves antigen recognition, activation, and cytokine production, which are not directly mediated by CD40 expression on T cells. - T-cell function would be indirectly affected due to the lack of proper B cell help and antigen presentation, but the direct impact of absent CD40 is on the cell expressing it (B cells).

Q: What is the interpretation of the given pedigree chart?

Autosomal dominant. ***Autosomal dominant*** - The trait appears in **every generation**, indicated by affected individuals in the first, second, and third generations [1]. - Both males and females are affected relatively equally, and affected individuals transmit the trait to approximately half of their offspring, consistent with **vertical transmission** [1]. - **Male-to-male transmission** is present, which definitively rules out X-linked inheritance patterns [1]. *Incomplete penetrance* - This pattern would typically show some individuals who carry the disease-causing genotype but **do not express the phenotype** (unaffected). - In this pedigree, all individuals who are expected to express the trait based on the clear dominant pattern are indeed affected. *Autosomal recessive* - This mode of inheritance would typically show **skipped generations**, meaning affected individuals would often have unaffected parents who are carriers [1]. - In this chart, every affected individual has at least one affected parent, ruling out an autosomal recessive pattern [1]. X-linked dominant - In X-linked dominant inheritance, **no male-to-male transmission** would be observed, as fathers pass their X chromosome only to daughters. - The presence of affected males transmitting the trait to male offspring rules out this inheritance pattern. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 148-151.

Q: In which of the following disorders, vaccines are not contraindicated in the person suffering from that disease?

Complement deficiency disorders. ***Complement deficiency disorders*** - While patients with **complement deficiencies** are susceptible to certain infections (especially by encapsulated bacteria), their adaptive immune system is generally intact. - Therefore, most vaccines, including **live attenuated vaccines**, are not contraindicated; in fact, vaccination is crucial for preventing infections in these patients. *Digeorge syndrome* - This syndrome involves **thymic hypoplasia or aplasia**, leading to severe **T-cell immunodeficiency**. - **Live attenuated vaccines** (e.g., MMR, varicella) are contraindicated due to the risk of uncontrolled replication of the vaccine strain in immunocompromised individuals. *Wiskott Aldrich syndrome* - This is an **X-linked immunodeficiency** characterized by immunodeficiency, eczema, and thrombocytopenia, involving defects in both T and B cell function, and **platelet dysfunction**. - Due to profound immune defects, particularly in T-cell function, **live attenuated vaccines** are contraindicated. *Ataxia telangiectasia* - This is an autosomal recessive disorder causing **progressive cerebellar ataxia**, telangiectasias, and severe **combined immunodeficiency (SCID)-like features** affecting both T and B cells, as well as an increased risk of malignancy. - Due to the severe immunodeficiency, **live attenuated vaccines** are contraindicated.

Q: A patient of schizophrenia is being treated with clozapine. For which rare but serious side effects should he be monitored?

Agranulocytosis. ***Agranulocytosis*** - **Agranulocytosis** is a severe and potentially fatal reduction in white blood cells (specifically neutrophils) that can occur with clozapine use [2, 3]. - This is the **rare but serious side effect** that requires mandatory monitoring, occurring in **0.8-2%** of patients. - Patients on clozapine require routine **complete blood count (CBC)** monitoring: **weekly for the first 6 months**, then biweekly for months 6-12, then monthly thereafter . - This is the primary reason clozapine has restricted use despite being the most effective antipsychotic for treatment-resistant schizophrenia. *Seizures* - While clozapine can lower the **seizure threshold** (especially at higher doses), seizures occur in **1-2%** of patients and are **dose-dependent** . - Seizures are a known side effect that warrants dosage adjustment, but they are **not as rare** as agranulocytosis and do not require the same intensive blood monitoring protocol. - Management involves dose reduction or adding anticonvulsants. *Hepatomegaly* - **Hepatic dysfunction** can occur with clozapine, but **hepatomegaly** (enlarged liver) itself is not one of its rare, life-threatening side effects requiring specific monitoring above other, more severe issues. - Liver enzyme elevation may be monitored, but this is not the primary "rare but serious" concern. *Renal bleed* - **Renal complications** or **renal bleeding** are not recognized as significant or specifically monitored rare side effects of clozapine. - Clozapine's major concerns primarily involve hematologic (agranulocytosis), cardiovascular (myocarditis), and metabolic systems.

Q: What is the MOA of thalidomide?

Angiogenesis inhibitor. ***Angiogenesis inhibitor*** - Thalidomide is known to **inhibit angiogenesis** [1] by blocking the formation of new blood vessels, a key mechanism in its anti-cancer effects. - It also has **immunomodulatory** [1], [2], [3] and **anti-inflammatory** properties, affecting cytokine production and immune cell function [1], [3]. *Inhibits factor Xa* - This is the mechanism of action for **direct oral anticoagulants (DOACs)** like rivaroxaban and apixaban, used to prevent blood clot formation. - Thalidomide does not primarily act on the **coagulation cascade** at this step. *Prevents folic acid synthesis in bacteria* - This is the classic mechanism of action for **sulfonamide antibiotics**, which target bacterial enzymes involved in folate metabolism. - Thalidomide is an **immunomodulatory drug** [2], [3], not an antibiotic that interferes with bacterial folic acid synthesis. *Inhibits leukotrienes* - **Leukotriene inhibitors**, such as montelukast and zafirlukast, are used to treat asthma and allergies by blocking inflammatory pathways. - Thalidomide's primary mechanism is not the direct inhibition of **leukotriene synthesis or receptor binding**.

Q: Which of the following is a new drug approved for Rett syndrome?

Trofinetide. ***Trofinetide*** - **Trofinetide**, marketed as Daybue, was approved by the FDA in **March 2023** specifically for the treatment of **Rett syndrome**. - It is a synthetic analog of **glycine-proline-glutamate (GPE)**, which is a cleavage product of **insulin-like growth factor-1 (IGF-1)**, and is thought to reduce neuroinflammation and improve synaptic function. - This is the **first and only FDA-approved drug** specifically indicated for Rett syndrome. *Sodium oxybate* - **Sodium oxybate (Xyrem)** is a CNS depressant (gamma-hydroxybutyrate or GHB) primarily used for the treatment of **narcolepsy with cataplexy**. - It is a GABA-B receptor agonist and has sedative properties, but it is **not approved for Rett syndrome**. - It does not address the underlying pathophysiology or core symptoms of Rett syndrome. *Memantine* - **Memantine** is an NMDA receptor antagonist used primarily for moderate to severe **Alzheimer's disease**. - While it has been studied in some neurodevelopmental disorders, it is **not approved for Rett syndrome**. - It may help with certain symptoms but is not a disease-specific treatment. *Lunesta* - **Lunesta (eszopiclone)** is a nonbenzodiazepine sedative-hypnotic medication used for the treatment of **insomnia**. - It is not indicated for **Rett syndrome** and would only address sleep disturbances symptomatically, not the core neurological deficits.

Q: What is the order of bands in a sarcomere from the Z-disc toward the center?

Z-A-H-M. ***Z-A-H-M*** - This sequence accurately represents the arrangement of bands within a **sarcomere** when moving from the **Z-disc** towards the central **M-line**. - The **Z-disc** anchors **actin (thin) filaments**, which extend into the **A-band**, partially overlapping with myosin (thick) filaments. The **H-zone** is within the A-band, and the **M-line** bisects the H-zone. *Z-M-A-H* - This order incorrectly places the **M-line** immediately after the **Z-disc** and before the A and H bands. - The **M-line** is located at the very center of the sarcomere, a significant distance from the Z-disc. *Z-H-A-M* - This sequence incorrectly places the **H-zone** before the entire **A-band**. - The **H-zone** is a region *within* the **A-band**, specifically where only myosin (thick) filaments are present without actin (thin) overlap. *Z-H-M-A* - This order incorrectly places the **H-zone** and **M-line** before the **A-band**. - The **A-band** encompasses the entire length of the myosin (thick) filaments and includes the **H-zone** and **M-line** centrally.

Q: A surgeon examined a case of hernia and was able to retract the hernial sac on examination but not the contents. Identify the type of hernia depicted in the image.

Reduction en masse. ***Reduction en masse*** - This occurs when the **hernia sac** is reduced into the abdomen but the contents remain incarcerated within the sac, still outside the peritoneal cavity. The image clearly depicts the sac being pushed back, while the bowel loop within it remains constricted at the neck. - This is a dangerous situation because the **incarcerated bowel** is not visible externally, yet remains at risk of strangulation and is often unrecognized. *Sliding hernia* - A sliding hernia involves a portion of the **retroperitoneal organ** (like the colon or bladder) forming part of the posterior wall of the hernia sac. - This typically occurs gradually, and the sac itself is not mistakenly reduced without its contents while the contents remain trapped. *Incarcerated hernia* - An incarcerated hernia means the contents of the hernia sac are **trapped** and cannot be manually reduced back into the abdominal cavity. - While the image shows incarcerated contents, the specific problem here is that the *sac* has been reduced without its contents, which is a particular complication rather than just general incarceration. *Maydl's hernia* - Maydl's hernia (also known as a W-hernia) describes a scenario where **two loops of bowel** are contained within the hernia sac, with a connecting loop of bowel located within the abdominal cavity, forming a 'W' shape. - The illustration shows only one loop of bowel within the sac and does not suggest the specific 'W' configuration or intra-abdominal strangulation of the connecting segment.

Question 1

An ICU patient is suffering from Rhinovirus infection. How do we treat the patient?

Accepted Answer

Supportive care only

Answer

Piperacillin + Tazobactam + Azithromycin

Answer

Clarithromycin

Answer

Cephalosporin + Ganciclovir

Question 2

CD 40 marker is absent in the person. Which of the following would be seen?

Accepted Answer

Impaired B cell function

Answer

Impaired Macrophage function

Answer

Impaired NK cell function

Answer

Impaired T cell function

Question 3

What is the interpretation of the given pedigree chart?

Accepted Answer

Autosomal dominant

Answer

Incomplete penetrance

Answer

Autosomal recessive

Answer

X-linked dominant

Question 4

Identify the correct statement regarding Amyloidosis?

Accepted Answer

Amyloid deposits have beta pleated sheet conformation

Answer

Secondary amyloidosis is AL

Answer

Amyloidosis is called so because of deposition of complex carbohydrates

Answer

All of the options

Question 5

In which of the following disorders, vaccines are not contraindicated in the person suffering from that disease?

Accepted Answer

Complement deficiency disorders

Answer

Digeorge syndrome

Answer

Wiskott Aldrich syndrome

Answer

Ataxia telangiectasia

Question 6

A patient of schizophrenia is being treated with clozapine. For which rare but serious side effects should he be monitored?

Accepted Answer

Agranulocytosis

Answer

Seizures

Answer

Hepatomegaly

Answer

Renal bleed

Question 7

What is the MOA of thalidomide?

Accepted Answer

Angiogenesis inhibitor

Answer

Inhibits factor Xa

Answer

Prevents folic acid synthesis in bacteria

Answer

Inhibits leukotrienes

Question 8

Which of the following is a new drug approved for Rett syndrome?

Accepted Answer

Trofinetide

Answer

Sodium oxybate

Answer

Memantine

Answer

Lunesta

Question 9

What is the order of bands in a sarcomere from the Z-disc toward the center?

Accepted Answer

Z-A-H-M

Answer

Z-M-A-H

Answer

Z-H-A-M

Answer

Z-H-M-A

Question 10

A surgeon examined a case of hernia and was able to retract the hernial sac on examination but not the contents. Identify the type of hernia depicted in the image.

Accepted Answer

Reduction en masse

Answer

Sliding hernia

Answer

Incarcerated hernia

Answer

Maydl's hernia

INI-CET 2023

Internal Medicine

Microbiology

Pathology

Pediatrics

Pharmacology

Physiology

Surgery