FMGE 2019 Practice Questions

Q: Which of the following interfere with iron absorption?

Phytates. ***Phytates*** - **Phytates** (phytic acid), found in plant-based foods like whole grains, legumes, nuts, and seeds, are **potent inhibitors of non-heme iron absorption**. - They **chelate non-heme iron** and form insoluble complexes in the gastrointestinal tract, making it unavailable for absorption. - Phytates are considered **the most significant dietary inhibitor** of iron absorption among the options listed. *Myoglobin* - **Myoglobin is a heme-containing protein** found in muscle tissue and serves as an excellent dietary source of readily absorbable **heme iron**. - It does **not interfere** with iron absorption; instead, it provides bioavailable heme iron. *Vitamin C* - **Vitamin C** (ascorbic acid) significantly **enhances the absorption of non-heme iron** by reducing ferric iron (Fe³⁺) to ferrous iron (Fe²⁺), which is more soluble and bioavailable. - It counteracts the inhibitory effects of phytates and other dietary inhibitors. - This is an **absorption enhancer, not an inhibitor**. *Oxalate* - **Oxalate** (oxalic acid), found in foods like spinach, rhubarb, and beet greens, can also **interfere with iron absorption** by forming insoluble complexes with iron and other minerals. - However, oxalate is a **less potent inhibitor** compared to phytates, and its primary effect is on calcium absorption. - While it does reduce iron bioavailability, **phytates remain the more clinically significant inhibitor** of iron absorption.

Q: Which type of anaemia is seen in vitamin B12 deficiency?

Macrocytic anemia. ***Macrocytic anemia*** - Vitamin B12 is essential for **DNA synthesis**, and its deficiency leads to impaired nuclear maturation and delayed cell division in erythroid precursors, resulting in abnormally large red blood cells called **megaloblasts**. - This impaired maturation process leads to the production of **macrocytic red blood cells** (high MCV) which are also often prematurely destroyed, contributing to the anemia. *Dimorphic anemia* - This term describes the presence of **two distinct red cell populations**, typically microcytic and macrocytic, which can occur with combined deficiencies such as iron and vitamin B12. - While vitamin B12 deficiency primarily causes macrocytic anemia, dimorphic anemia is not its standalone feature unless accompanied by another deficiency. *Microcytic anemia* - Characterized by **abnormally small red blood cells** (low MCV), typically seen in conditions like **iron deficiency anemia** or thalassemia. - Vitamin B12 deficiency causes large red blood cells, thus ruling out microcytic anemia. *Normocytic anemia* - Red blood cells are of **normal size** (normal MCV) but are reduced in number, often seen in conditions like **anemia of chronic disease** or acute blood loss. - Since vitamin B12 deficiency directly impacts red blood cell size by causing megaloblastic changes, normocytic anemia is not the primary presentation.

Q: A 40-year-old male presents with fever and abdominal pain and is diagnosed with HIV and TB. What is the most appropriate sequence of treatment?

ATT followed by ART within 2-8 weeks. ***ATT followed by ART within 2-8 weeks*** - This sequence is crucial for patients with co-infection of **HIV and TB**. Initiating **anti-tuberculous treatment (ATT)** first is vital to control the active TB infection, which can be rapidly fatal [2]. - Subsequently, starting **antiretroviral therapy (ART)** within 2-8 weeks (typically 2-4 weeks after ATT in patients without CNS TB) helps to restore the immune system and prevent other opportunistic infections, but delaying it slightly reduces the risk of **IRIS (Immune Reconstitution Inflammatory Syndrome)** [1]. *First ATT and then ART* - While starting ATT first is correct, this option is too vague regarding the timing of ART initiation. - The specific window of 2-8 weeks (or 2-4 weeks without CNS TB) is important to balance TB treatment efficacy and mitigate **IRIS risk** [1]. *ATT only* - This approach is incorrect as it fails to address the underlying HIV infection, which would lead to continued immune decline and increased morbidity and mortality. - ART is essential for improving prognosis and reducing viral load in HIV-infected individuals. *First ART and then ATT* - Initiating ART before ATT in co-infected patients with active TB can worsen the TB condition due to **IRIS**, which can be severe and life-threatening [1]. - ART can cause a rapid immune reconstitution and paradoxical worsening of symptoms or presentation of subclinical TB [1].

Q: Bacterial vaginosis is caused by all except

Proteus. ***Proteus*** - **Proteus** species are commonly associated with **urinary tract infections (UTIs)** and wound infections, not typically with bacterial vaginosis. - The presence of **Proteus** in vaginal flora is generally considered an opportunistic infection rather than a causative agent of BV. *Coccobacillus* - **Coccobacillary bacteria**, such as **Gardnerella vaginalis**, are primary organisms contributing to the polymicrobial shift that defines bacterial vaginosis. - The disruption of normal lactobacilli dominance allows for the overgrowth of these specific anaerobic and facultative organisms. *Mobiluncus* - **Mobiluncus species** are curved, rod-shaped anaerobic bacteria frequently found in high numbers in women with bacterial vaginosis. - They are considered key anaerobic bacteria involved in the microbial imbalance characteristic of BV. *Gardnerella* - **Gardnerella vaginalis** is the most commonly isolated bacterium in bacterial vaginosis and is considered the primary initiating organism. - While BV is polymicrobial, **Gardnerella's** overgrowth is central to the diagnostic criteria and pathogenesis.

Q: Most sensitive test for detecting microfilariae?

Membrane filtration technique. ***Membrane filtration technique*** - The **membrane filtration technique** is considered the most sensitive test for detecting **microfilariae** because it concentrates microfilariae from a larger volume of blood (typically 1 mL or more) onto a filter membrane, increasing detection rates, especially in low-parasite density infections. - This method physically traps the microfilariae, allowing for microscopic examination of the concentrated sample after staining, which enhances visualization. *Diethylcarbamazine (DEC) challenge test* - The **DEC challenge test** uses **diethylcarbamazine** to provoke the release of microfilariae into the peripheral blood, especially in cases of occult filariasis or when microfilaria numbers are low. - While it can be useful in certain diagnostic situations, it is **less sensitive** than membrane filtration for directly detecting circulating microfilariae and carries the risk of inducing severe adverse reactions due to rapid parasite killing. *Fluorescence-based immunoassay* - **Fluorescence-based immunoassays** detect **antigens** or **antibodies** related to filarial infection, providing evidence of exposure or active infection. - While valuable for diagnosis, especially in antibody detection for chronic or occult infections, they do not directly detect live microfilariae and thus are not the most sensitive method for *detecting microfilariae themselves*. *Thick blood smear* - A **thick blood smear** is a common and quick method for detecting microfilariae by examining a drop of blood for their presence. - However, it is **less sensitive** than the membrane filtration technique, particularly in persons with low microfilaremia, as it examines a much smaller volume of blood.

Q: Which of the following is a carbonic anhydrase inhibitor?

Acetazolamide. ***Acetazolamide*** - Acetazolamide is a classic example of a **carbonic anhydrase inhibitor**, primarily used as a diuretic and for managing **glaucoma** and **altitude sickness**. - It works by inhibiting the enzyme **carbonic anhydrase** in the **proximal renal tubule**, reducing bicarbonate reabsorption and thus promoting diuresis. *Hydrochlorothiazide* - Hydrochlorothiazide is a **thiazide diuretic** that acts on the **distal convoluted tubule** to inhibit the reabsorption of sodium and chloride. - It is not a carbonic anhydrase inhibitor. *Mannitol* - Mannitol is an **osmotic diuretic** that works in the **proximal tubule** and **descending limb of Henle's loop** by creating an osmotic gradient. - It is not a carbonic anhydrase inhibitor and functions by drawing water into the renal tubule, leading to increased urine output. *Furosemide* - Furosemide is a **loop diuretic** that acts on the **thick ascending limb of the loop of Henle** by inhibiting the Na+-K+-2Cl- cotransporter. - It is one of the most potent diuretics but does not inhibit carbonic anhydrase.

Q: Which of the following anti-epileptic drugs has the highest teratogenic potential?

Valproate. ***Correct: Valproate*** - **Valproate has the highest teratogenic potential** among all anti-epileptic drugs, with a **10-20% risk of major congenital malformations** - **Neural tube defects** (spina bifida) occur in **1-2% of exposed pregnancies**, which is 10-20 times higher than the general population - Other significant risks include **cardiac malformations, craniofacial abnormalities**, and **neurodevelopmental disorders** (autism spectrum disorder, reduced IQ) - **Fetal valproate syndrome** is a recognized clinical entity - Current guidelines strongly recommend **avoiding valproate in women of childbearing potential** unless no alternatives exist *Incorrect: Carbamazepine* - Has teratogenic risks but significantly **lower than valproate** (2-5% risk of major malformations) - Associated with **neural tube defects** (0.5-1% risk, lower than valproate) - Considered a safer alternative when valproate must be avoided *Incorrect: Phenytoin* - Causes **fetal hydantoin syndrome** with characteristic features: craniofacial anomalies, nail/digital hypoplasia, growth restriction, and developmental delay - Teratogenic risk is **moderate** (approximately 5-10% risk of major malformations) - Risk is significant but **lower than valproate** *Incorrect: Lamotrigine* - Considered **one of the safest anti-epileptic drugs** during pregnancy - Low teratogenic risk with **major malformation rate of 2-3%** (close to baseline population risk) - Slight increased risk of **oral clefts** at higher doses - **Preferred choice** for women of childbearing potential requiring anti-epileptic therapy

Q: Insulin of choice for the treatment of diabetic ketoacidosis is:

Regular Insulin. ***Regular Insulin*** - **Regular insulin** is the insulin of choice for treating **diabetic ketoacidosis (DKA)** because it can be administered intravenously. - Its **short onset of action** and predictable duration allow for rapid and precise titration in a critical care setting. *Insulin lispro* - **Insulin lispro** is a **rapid-acting insulin analog** typically used for mealtime coverage, which has a very quick onset and short duration. - While it acts quickly, its primary use is not for the continuous intravenous infusion required in DKA management. *Insulin glargine* - **Insulin glargine** is a **long-acting insulin analog** designed to provide basal insulin replacement. - It has a prolonged duration of action and a slow, sustained release profile, making it unsuitable for the rapid correction needed in DKA. *NPH insulin* - **NPH insulin** is an **intermediate-acting insulin** that has a delayed onset and peak effect. - Its insoluble nature and variable absorption make it inappropriate for the acute, immediate intravenous insulin therapy required in DKA.

Q: PR interval in ECG shows?

Atrial depolarization and conduction delay. ***Atrial depolarization and conduction delay*** - The **PR interval** is measured from the **beginning of the P wave** to the **beginning of the QRS complex**. - It represents the **complete time** for the electrical impulse to travel from the SA node through the atria, the AV node, the Bundle of His, and bundle branches until ventricular depolarization begins. - This includes two major components: 1. **Atrial depolarization** (represented by the P wave) 2. **Conduction delay** through the AV node and His-Purkinje system (the isoelectric segment after the P wave) - **Normal PR interval**: 0.12-0.20 seconds (120-200 ms) - The **AV nodal delay** is the longest component, allowing atrial contraction to complete before ventricular contraction begins. *Conduction through AV node* - While **AV nodal conduction** is an important component of the PR interval, this option is **incomplete**. - The PR interval begins with the **P wave** (atrial depolarization), which occurs before the impulse reaches the AV node. - Stating only "conduction through AV node" ignores the atrial depolarization component that is also part of the PR interval. *Delay in ventricular depolarization* - **Ventricular depolarization** is represented by the **QRS complex**, not the PR interval. - The PR interval *ends* when ventricular depolarization begins (start of QRS). *Delay in ventricular repolarization* - **Ventricular repolarization** is represented by the **T wave** on an ECG. - This occurs much later in the cardiac cycle and is not related to the PR interval.

Q: Which of the following typically results in the maximum radiation exposure?

PET CT. ***PET CT*** - **PET CT (Positron Emission Tomography-Computed Tomography)** combines the radiation from both a PET scan (using radiotracers like FDG) and a CT scan, resulting in the highest typical radiation exposure among the listed options. - The integration of functional (PET) and anatomical (CT) imaging, while providing comprehensive diagnostic information, significantly increases the total absorbed dose (~20-30 mSv). *Chest X-ray* - A **chest X-ray** involves a very low dose of radiation (~0.1 mSv), making it one of the imaging modalities with the least radiation exposure. - Due to its low dose and widespread use, the benefits of chest X-rays in diagnosing pulmonary and cardiac conditions far outweigh the minimal radiation risk. *IV pyelography* - **Intravenous pyelography (IVP)**, or intravenous urography, uses X-rays and contrast dye to visualize the urinary tract, delivering a moderate radiation dose (~3-5 mSv). - While higher than a standard X-ray, its dose is significantly lower than that of complex combined imaging like PET-CT. *Barium Enema* - A **barium enema** involves multiple X-ray images of the large intestine after administering barium contrast, leading to a moderate to high radiation dose (~8-15 mSv). - The series of exposures required to adequately visualize the entire colon contributes to a higher cumulative dose compared to single-shot X-rays.

Question 1

Which of the following interfere with iron absorption?

Accepted Answer

Phytates

Answer

Myoglobin

Answer

Vitamin C

Answer

Oxalate

Question 2

Which type of anaemia is seen in vitamin B12 deficiency?

Accepted Answer

Macrocytic anemia

Answer

Dimorphic anemia

Answer

Microcytic anemia

Answer

Normocytic anemia

Question 3

A 40-year-old male presents with fever and abdominal pain and is diagnosed with HIV and TB. What is the most appropriate sequence of treatment?

Accepted Answer

ATT followed by ART within 2-8 weeks

Answer

First ATT and then ART

Answer

ATT only

Answer

First ART and then ATT

Question 4

Bacterial vaginosis is caused by all except

Accepted Answer

Proteus

Answer

Coccobacillus

Answer

Mobiluncus

Answer

Gardnerella

Question 5

Most sensitive test for detecting microfilariae?

Accepted Answer

Membrane filtration technique

Answer

Diethylcarbamazine (DEC) challenge test

Answer

Fluorescence-based immunoassay

Answer

Thick blood smear

Question 6

Which of the following is a carbonic anhydrase inhibitor?

Accepted Answer

Acetazolamide

Answer

Hydrochlorothiazide

Answer

Mannitol

Answer

Furosemide

Question 7

Which of the following anti-epileptic drugs has the highest teratogenic potential?

Accepted Answer

Valproate

Answer

Carbamazepine

Answer

Phenytoin

Answer

Lamotrigine

Question 8

Insulin of choice for the treatment of diabetic ketoacidosis is:

Accepted Answer

Regular Insulin

Answer

Insulin lispro

Answer

Insulin glargine

Answer

NPH insulin

Question 9

PR interval in ECG shows?

Accepted Answer

Atrial depolarization and conduction delay

Answer

Conduction through AV node

Answer

Delay in ventricular depolarization

Answer

Delay in ventricular repolarization

Question 10

Which of the following typically results in the maximum radiation exposure?

Accepted Answer

PET CT

Answer

Chest X ray

Answer

IV pyelography

Answer

Barium Enema

Answer

X-ray abdomen

FMGE 2019

Biochemistry

Internal Medicine

Microbiology

Pharmacology

Physiology

Radiology