MDS PREP
What is the primary role of ceruloplasmin?
1) Transport of copper
2) Anti-inflammatory activity
3) Lipid metabolism
4) Blood clotting
Ceruloplasmin is a protein synthesized in the liver that primarily functions to transport and regulate the levels of copper in the bloodstream. It is not directly involved in blood clotting or inflammation.
Which of the following is NOT a common cause of pseudomembranous colitis?
1) Clostridium difficile
2) Salmonella enterotoxin
3) Staphylococcus aureus toxin
4) Escherichia coli toxins
Pseudomembranous colitis is generally caused by Clostridium difficile toxins, which are not produced by Salmonella or E. coli. These latter organisms are associated with food poisoning due to different types of enterotoxins.
What is the primary function of the pancreatic islets in relation to Zollinger Ellison syndrome?
1) Producing insulin
2) Producing glucagon
3) Producing somatostatin
4) Producing gastrin
In Zollinger Ellison syndrome, the pancreatic islets are involved because they contain the gastrin-producing cells that form the gastrinomas. The overproduction of gastrin is the main pathological mechanism leading to the disease's clinical manifestations.
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.
A patient with hyperparathyroidism presents with peptic ulcer disease. What is the most likely underlying mechanism?
1) Direct action of parathyroid hormone (PTH) on gastric mucosa
2) Indirect effects of PTH-induced hypercalcemia on gastric acid secretion
3) Secondary hypergastrinemia due to vitamin D deficiency
4) Autonomic neuropathy affecting gastric emptying
Hypercalcemia, which is commonly seen in hyperparathyroidism, can suppress gastric mucosal function and lead to peptic ulcer disease.
What is the primary mechanism by which proteinuria occurs in minimal-change disease?
1) Increased glomerular permeability due to alterations in the glomerular basement membrane
2) Immune complex deposition in the glomeruli
3) Alteration in the podocyte slit diaphragm
4) Reduced synthesis of plasma proteins
In minimal-change disease, the primary mechanism of proteinuria is thought to be increased permeability of the glomerular capillary wall to proteins due to changes in the glomerular basement membrane, rather than structural damage to the membrane itself.
In which condition breath sounds are absent
1) Bronchial asthma
2) Pneumothorax
3) Emphysema
4) Pneumonia
General Medicine
Answer: 2
In pneumothorax, breath sounds are absent
What is the primary mechanism of action of the heat-labile toxin produced by ETEC?
1) Increases intracellular cAMP
2) Increases intracellular cGMP
3) Inhibits DNA synthesis
4) Induces lipid peroxidation
The heat-labile toxin (LT) of ETEC is similar to cholera toxin and acts by increasing intracellular cAMP levels in enterocytes, leading to excessive chloride and fluid secretion into the lumen of the gut, resulting in diarrhea.