MDS PREP
The most important aspect in treating Disseminated intravascular Coagulation (DIC) is to
1) Administer heparin
2) Administer platelets
3) Treat the underlying disease process
4) Achieve normal levels of fibrinogen
General Medicine
Answer: 3
DIC is a serious condition characterized by the widespread activation of the coagulation cascade, leading to the formation of blood clots throughout the small blood vessels. This can result in organ dysfunction and bleeding. The most critical step in managing DIC is to identify and treat the underlying cause (such as infection, trauma, or malignancy) because addressing the root issue can help resolve the coagulation abnormalities.
What is the primary mechanism of action of the heat-stable toxin produced by ETEC?
1) Increases intracellular cAMP
2) Increases intracellular cGMP
3) Induces lipid peroxidation
4) Inhibits DNA synthesis
The heat-stable toxin (ST) of ETEC increases intracellular cGMP, leading to increased fluid and electrolyte secretion into the gut lumen, contributing to the diarrheal illness.
Which of the following is NOT a function of fibrinogen in the coagulation cascade?
1) Precursor to fibrin
2) Coagulation factor stabilizer
3) Blood clot formation
4) Blood clot dissolution
Fibrinogen is essential for blood clot formation as it is converted into fibrin by thrombin. However, its role is not in dissolving blood clots; that is primarily the function of plasminogen, which is converted to plasmin.
What gene is commonly associated with Peutz-Jeghers syndrome?
1) APC
2) LKB1/STK11
3) MUTYH
4) TP53
Peutz-Jeghers syndrome is associated with mutations in the LKB1/STK11 gene. This autosomal dominant disorder is characterized by gastrointestinal hamartomatous polyps and mucocutaneous hyperpigmentation, and it increases the risk of various malignancies.
In a patient with suspected myasthenia gravis, which of the following is the most sensitive and specific diagnostic test?
1) Acetylcholine receptor antibody test
2) Tensilon (edrophonium) test
3) Repetitive nerve stimulation
4) Electromyogram (EMG)
The presence of acetylcholine receptor antibodies in the serum is the most sensitive and specific diagnostic test for myasthenia gravis.
What is the rationale behind administering hydrocortisone in the treatment of anaphylactic shock?
1) It directly blocks histamine receptors
2) It reduces vascular permeability and suppresses the inflammatory response
3) It is a bronchodilator
4) It is an antihypertensive agent
Hydrocortisone, a glucocorticoid, is administered to reduce vascular permeability and suppress the systemic inflammatory response in anaphylaxis. Its effects are not immediate but can help in preventing a biphasic reaction and prolonging symptoms.
Which of the following drugs acts by enzyme inhibition?
1) salbutamol
2) acetazolamide
3) tolbutamide
4) chlorpromazine
General Medicine Answer: 2
Acetazolamide is a carbonic anhydrase inhibitor that reduces aqueous humour production and is therefore indicated in glaucoma to reduce the intraocular pressure.
Salbutamol is a selective, short-acting beta2-agonist used as a bronchodilator in asthma. Tolbutamide is a short-acting sulphonylurea used in type 2 (non-insulin dependent) diabetes mellitus.
Chlorpromazine is an aliphatic neuroleptic antipsychotic drug used in schizophrenia.
Hypercalcaemia occurs in which type of lung cancer?
1) Oat cell
2) Giant cell
3) Squamous cell
4) Alveolar cell
General Medicine
Answer: 3
Hypercalcaemia is commonly associated with squamous cell lung carcinoma due to parathyroid hormone-related peptide (PTHrP) production, which mimics parathyroid hormone and raises calcium levels.