Biochemistry
2 questionsVitamin K leads to?
Colipase is found in?
FMGE 2017 - Biochemistry FMGE Practice Questions and MCQs
Question 21: Vitamin K leads to?
- A. β-carboxylation of glutamic acid residues in clotting factors II, VII, IX, and X
- B. α-carboxylation of aspartic acid residues in clotting factors II, VII, IX, and X
- C. γ-carboxylation of aspartic acid residues in clotting factors II, VII, IX, and X
- D. γ-carboxylation of glutamic acid residues in clotting factors II, VII, IX, and X (Correct Answer)
Explanation: ***γ-carboxylation of glutamic acid residues in clotting factors II, VII, IX, and X*** - Vitamin K acts as a **cofactor** for the enzyme **γ-glutamyl carboxylase**, which is essential for the post-translational modification of specific clotting factors. - This modification involves adding a **carboxyl group** to the **gamma-carbon** of certain **glutamic acid residues** within coagulation factors II (prothrombin), VII, IX, and X, converting them to **γ-carboxyglutamic acid (Gla) residues**. - These Gla residues enable the clotting factors to bind **calcium ions**, which is critical for their activation and proper function in the coagulation cascade. *β-carboxylation of glutamic acid residues in clotting factors II, VII, IX, and X* - This option incorrectly states **beta-carboxylation**, whereas the correct process is **gamma-carboxylation**. - The specific carbon atom modified (gamma position) is crucial for the proper function of the clotting factors. *γ-carboxylation of aspartic acid residues in clotting factors II, VII, IX, and X* - This option incorrectly identifies the amino acid residue involved as **aspartic acid**. - Vitamin K-dependent carboxylation specifically modifies **glutamic acid residues**, not aspartic acid. *α-carboxylation of aspartic acid residues in clotting factors II, VII, IX, and X* - This option incorrectly specifies both the carbon position involved (**alpha-carboxylation**) and the amino acid residue (**aspartic acid**). - The correct process is **gamma-carboxylation** of **glutamic acid residues**.
Question 22: Colipase is found in?
- A. Pancreatic juice (Correct Answer)
- B. Saliva
- C. Bile
- D. Succus entericus
Explanation: ***Pancreatic juice*** - **Colipase** is a co-enzyme secreted by the **pancreas** that is essential for the activity of pancreatic lipase. - It helps **pancreatic lipase** anchor to the surface of fat globules, preventing its inactivation by bile salts and facilitating fat digestion. *Saliva* - Saliva primarily contains **alpha-amylase** (ptyalin) for carbohydrate digestion and **lingual lipase** for initial fat digestion. - It does not contain colipase. *Bile* - **Bile** is produced by the liver and stored in the gallbladder, primarily aiding in fat emulsification. - It contains **bile salts**, cholesterol, bilirubin, and phospholipids but not digestive enzymes like colipase. *Succus entericus* - **Succus entericus**, or intestinal juice, is secreted by the small intestine and contains enzymes like **sucrase**, **maltase**, **lactase**, and peptidases. - It does not contain colipase, which is specifically a pancreatic enzyme.
Community Medicine
2 questionsWhat is the incubation period of hepatitis B?
In a clinical laboratory, when is sample registration typically performed?
FMGE 2017 - Community Medicine FMGE Practice Questions and MCQs
Question 21: What is the incubation period of hepatitis B?
- A. 1 - 30 days
- B. 2 weeks - 6 months
- C. 45 - 180 days (Correct Answer)
- D. 15 - 45 days
Explanation: ***45 - 180 days*** - The typical incubation period for **Hepatitis B** infection ranges from **45 to 180 days** (approximately 6 weeks to 6 months). - This relatively long incubation period is characteristic of the **Hepadnaviridae family** to which HBV belongs. *1 - 30 days* - This period is generally too short for **Hepatitis B** and is more typical for certain **bacterial or viral respiratory illnesses**. - It does not align with the known epidemiology and viral replication cycle of **HBV**. *2 weeks - 6 months* - While **6 months** falls within the upper range, the lower limit of **2 weeks** (14 days) is generally too short for the typical incubation period of Hepatitis B. - The more precise range starts closer to **6 weeks (42 days)**. *15 - 45 days* - This range is too short for the common incubation period of **Hepatitis B**. - This period is more commonly associated with other viral infections, such as **Hepatitis A**.
Question 22: In a clinical laboratory, when is sample registration typically performed?
- A. When samples are received at the laboratory (Correct Answer)
- B. At the end of each working day
- C. Once per week during batch processing
- D. Only during quality control audits
Explanation: ***When samples are received at the laboratory*** - **Sample registration** is a critical step performed immediately upon a sample's arrival to ensure proper identification and tracking throughout its lifecycle in the laboratory. - This initial registration helps prevent **errors**, maintains **sample integrity**, and establishes a clear **audit trail**. *At the end of each working day* - Delaying registration until the end of the day introduces a significant risk of **misidentification**, **loss**, or **degradation** of samples. - Urgent or time-sensitive tests would be unduly **delayed**, potentially impacting patient care. *Once per week during batch processing* - Weekly batch processing for registration is entirely unsuitable for a clinical laboratory, where timely processing of individual samples is paramount. - This practice would lead to a massive backlog, compromise **sample stability**, and make it impossible to provide **prompt results** for patient diagnosis and treatment. *Only during quality control audits* - **Quality control audits** periodically review laboratory processes, including registration, but do not replace the need for real-time, continuous sample registration. - Relying solely on audits for registration would mean unregistered samples are processed, leading to **untraceable results** and potential patient harm.
Internal Medicine
2 questionsTropical pulmonary eosinophilia is most characteristically seen due to which of the following infections?
Which of the following is true about carcinoid tumor?
FMGE 2017 - Internal Medicine FMGE Practice Questions and MCQs
Question 21: Tropical pulmonary eosinophilia is most characteristically seen due to which of the following infections?
- A. Roundworm
- B. Trichinella
- C. Ancylostoma
- D. Filaria (Correct Answer)
Explanation: *Filaria* - **Tropical pulmonary eosinophilia (TPE)** is a hypersensitivity reaction to microfilariae from filarial nematodes like *Wuchereria bancrofti* and *Brugia malayi* [1]. - It is characterized by cough, dyspnea, wheezing, and marked **peripheral eosinophilia**, with interstitial infiltrates on chest X-ray [1]. *Roundworm* - **Ascaris lumbricoides** can cause **Loeffler's syndrome**, a transient pulmonary infiltration with eosinophilia during larval migration, but not chronic TPE [2]. - Symptoms are usually less severe and self-limiting compared to TPE [2]. *Trichinella* - **Trichinella spiralis** causes **trichinellosis**, presenting with muscle pain, fever, and periorbital edema, possibly with eosinophilia, but typically does not manifest as TPE. - Pulmonary involvement is rare and not the characteristic feature. *Ancylostoma* - **Hookworm (Ancylostoma duodenale, Necator americanus)** larvae can cause mild pulmonary symptoms and eosinophilia during migration through the lungs [3]. - However, they also do not typically lead to the severe and chronic pulmonary symptoms seen in TPE [3].
Question 22: Which of the following is true about carcinoid tumor?
- A. Presentation is hypotension and diaphoresis
- B. Intestinal carcinoids are of high malignant potential
- C. Best diagnosed by elevated urinary vanillymandelic acid levels
- D. Can occur throughout the gastrointestinal tract (Correct Answer)
Explanation: ***Can occur throughout the gastrointestinal tract*** - Carcinoid tumors (neuroendocrine tumors) are most commonly found in the **gastrointestinal tract**, particularly in the small intestine, appendix, rectum, and stomach [2]. - They arise from **enterochromaffin cells** and can secrete various vasoactive substances. *Presentation is hypotension and diaphoresis* - The classic presentation of **carcinoid syndrome** includes episodes of **flushing**, **diarrhea**, and **bronchospasm**, often accompanied by **hypertension** rather than hypotension due to the release of serotonin and other vasoactive peptides [1]. - While diaphoresis can occur, **hypotension** is not a primary or characteristic feature. *Intestinal carcinoids are of high malignant potential* - The malignant potential of carcinoid tumors varies depending on their primary site and size but is generally considered to be of **low-to-moderate malignant potential**, particularly for appendiceal and rectal carcinoids [2]. - Liver metastases significantly increase morbidity and mortality, but many small intestinal carcinoids may grow slowly or remain localized for extended periods [1]. *Best diagnosed by elevated urinary vanillymandelic acid levels* - Elevated **urinary vanillymandellic acid (VMA)** levels are primarily used to diagnose **pheochromocytoma**, a tumor of the adrenal medulla that secretes catecholamines. - Carcinoid tumors are best diagnosed by measuring **urinary 5-hydroxyindoleacetic acid (5-HIAA)**, a breakdown product of serotonin.
Pharmacology
3 questionsWhich of the following aminoglycosides is most cochleotoxic:-
Zileuton is:-
Which among the following is an iron chelator?
FMGE 2017 - Pharmacology FMGE Practice Questions and MCQs
Question 21: Which of the following aminoglycosides is most cochleotoxic:-
- A. Streptomycin
- B. Amikacin
- C. Gentamycin (Correct Answer)
- D. Minocycline
Explanation: ***Gentamycin*** - **Gentamycin** is known to be the most **cochleotoxic** aminoglycoside, causing irreversible damage to the hair cells in the cochlea [1]. - This toxicity can lead to **permanent hearing loss** and **tinnitus** due to its selective accumulation in inner ear fluids [2]. *Streptomycin* - While streptomycin can cause ototoxicity, its primary adverse effect is vestibulo-toxicity, affecting **balance** more than hearing [2]. - It mainly targets the hair cells of the semicircular canals and otolithic organs, leading to **vertigo** and ataxia [3]. *Amikacin* - Amikacin is also an ototoxic aminoglycoside but is generally considered **less cochleotoxic** than gentamycin. - Its ototoxic effects are comparable to gentamicin, but it is often reserved for infections resistant to other aminoglycosides. *Minocycline* - Minocycline is a **tetracycline antibiotic**, not an aminoglycoside, and is not associated with significant ototoxicity. - Its side effects typically include photosensitivity, gastrointestinal upset, and **vestibular dysfunction** (dizziness, vertigo) in some patients, distinct from cochlear damage.
Question 22: Zileuton is:-
- A. Phospholipase inhibitor
- B. Leukotriene receptor antagonist
- C. 5-Lipoxygenase inhibitor (Correct Answer)
- D. Cyclooxygenase inhibitor
Explanation: ***5-Lipoxygenase inhibitor*** - **Zileuton** specifically inhibits **5-lipoxygenase**, an enzyme crucial for the synthesis of **leukotrienes**. - By blocking this enzyme, zileuton reduces the production of **pro-inflammatory leukotrienes**, which are involved in the pathophysiology of **asthma**. *Phospholipase inhibitor* - **Phospholipase A2 inhibitors** like **corticosteroids** act upstream by preventing the release of **arachidonic acid**, a precursor to both prostaglandins and leukotrienes. - Zileuton's action is more specific to the **leukotriene pathway**, occurring after arachidonic acid is already formed. *Cyclooxygenase inhibitor* - **Cyclooxygenase (COX) inhibitors** (like NSAIDs) block the synthesis of **prostaglandins** and **thromboxanes** from arachidonic acid. - Zileuton does not affect the COX pathway but rather targets the **lipoxygenase pathway**. *Leukotriene receptor antagonist* - **Leukotriene receptor antagonists** (e.g., Montelukast, Zafirlukast) block the binding of leukotrienes to their receptors, preventing their downstream effects. - While both target the **leukotriene pathway**, zileuton works by **inhibiting their production**, not their receptor binding.
Question 23: Which among the following is an iron chelator?
- A. BAL
- B. Desferrioxamine (Correct Answer)
- C. EDTA
- D. Penicillamine
Explanation: ***Desferrioxamine*** - **Desferrioxamine** is a specific iron chelator used to treat **acute iron poisoning** and chronic iron overload, such as in patients with **thalassemia** requiring frequent transfusions. - It works by binding to free iron in the bloodstream and promoting its **excretion via urine**. *BAL* - **BAL (dimercaprol)** is primarily used as a chelating agent for **heavy metal poisoning**, particularly **arsenic, mercury, and lead** [1], [2]. - While it can chelate some metals, its affinity and primary use are not for iron. *EDTA* - **EDTA (ethylenediaminetetraacetic acid)** is a chelator often used for **lead poisoning** [1], [2] and hypercalcemia. - It has a high affinity for various divalent and trivalent metal ions [2], but it is not the primary or most specific iron chelator. *Penicillamine* - **Penicillamine** is a chelating agent primarily used for the treatment of **copper overload** in **Wilson's disease**. - It is also used in the treatment of severe **rheumatoid arthritis** and **cystinuria**, but not typically for iron chelation.
Physiology
1 questionsIn which of the following conditions is blood osmolality increased?
FMGE 2017 - Physiology FMGE Practice Questions and MCQs
Question 21: In which of the following conditions is blood osmolality increased?
- A. SIADH
- B. Psychogenic polydipsia
- C. Diarrhea (Correct Answer)
- D. Cerebral toxoplasmosis
Explanation: ***Diarrhea*** - Diarrhea leads to a significant loss of **water and electrolytes** from the body, primarily from the extracellular fluid compartment. - This imbalance causes **hemoconcentration** and an increase in the concentration of solutes in the blood, thereby raising blood osmolality. *SIADH* - **Syndrome of Inappropriate Antidiuretic Hormone (SIADH)** is characterized by excessive secretion of ADH, leading to **dilutional hyponatremia**. - The excess water retention dilutes the blood, resulting in **decreased serum osmolality**. *Psychogenic polydipsia* - This condition involves excessive water intake due to psychological factors, which causes **dilution of body fluids**. - The increased water volume without a proportional increase in solutes leads to **decreased plasma osmolality**. *Cerebral toxoplasmosis* - **Cerebral toxoplasmosis** is an opportunistic infection of the brain, typically seen in immunocompromised individuals. - It primarily causes neurological symptoms and **does not directly impact blood osmolality** unless complicated by other factors like dehydration or SIADH (which is not a primary effect).