HIV / AIDS - Investigations MCQs

CD4 cell count and viral load have to be monitored every 3-6 months to monitor the response to treatment. Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 334

Gastrin is produced in response to Stimulation by neural reflex pathways By the direct effect of digested peptides on the G cells themselves. Gastrin is mainly produced by the G cells of the gastric antrum. Gastrin stimulates the production of bicarbonate by pancreas. It stimulates the parietal cells to produce hydrochloric acid. Reference : Harrison's Principles of Internal Medicine 21 st Ed, Ch: 324, Pg: 2435

Whilst a plain radiograph may be used to demonstrate retrosternal thyroid extension and tracheal deviation, a CT of the chest is more sensitive and specific in determining the extent of disease. Thyroid ultrasound is most useful for determining the nature of thyroid nodules. Radioisotope scanning has a role to play in determining the uptake of thyroid hormone and as such the underlying diagnosis behind thyrotoxicosis, or in identifying cold nodules within the gland which may raise the suspicion of an underlying neoplasm. Reference: Harrison's Principles of Internal Medicine 21 st edition Page:2946

IgM, IgG, and IgA isotypes of RF occur in sera from patients with RA, although the IgM isotype is the one most frequently measured by commercial laboratories. The sensitivity of RA is only 75%, therefore a negative test does not exclude the presence of the disease. False positive in other connective tissue diseases, such as primary Sjogren's syndrome, systemic lupus erythematosus, and type II mixed essential cryoglobulinemia, as well as chronic infections such as subacute bacterial endocarditis and hepatitis B and C. Serum RF may also be detected in 1-5% of the healthy population. Anti CCP has sensitivity almost similar to RA factor, but is almost 95% specific for RA. Anti CCP has a role in predicting the outcomes too, as it is associated with worse outcomes. Reference: Harrison's Principles of Internal Medicine 21st edition Ch:358 Pg:2759

The most appropriate treatment for this asymptomatic man with an isolated slightly elevated urate is lifestyle advice with an appropriately reduced purine diet, increased exercise and reduced alcohol consumption. Reference: Harrison's Principles of Internal Medicine, 21 st ed, Ch: 372, Pg: 2863-2865

In adrenal destruction, serum Na, Cl and HCO3 levels are reduced, and serum potassium is elevated. The hyponatraemia is due to both loss of sodium in the urine (due to aldosterone and cortisol deficiency) and to movement into the intracellular compartment. Hyperkalemia is due to a combination of aldosterone deficiency, impaired glomerular filtration (due to hypotension) and acidosis. Mild to moderate hypercalcemia occurs in 10-20% patients, the cause of which is uncertain. Reference : Harrison's Principles of Internal Medicine 21 st edition Page 2971

This question deals with Nephrotic syndrome in pedaitric patient. The most common cause is Minimal change disease. Light microscopy will be normal. If will either show no deposits or minimal IgM and electron microscope shows effacement of foot processes. The treatment is steroids. 80% of patients achieve remission with prednisolone therapy. Cyclophosphamide treatment can be started for those who are steroid resistant Reference: Harrison's Principles of Internal Medicine, 21 st ed, Ch: 314, Pg: 2341.

The likely explanation for failure of an iron deficiency anemia to respond iron therapy in a patient with heavy periods is poor compliance. Folate deficiency will cause a Megaloblastic picture with MCV>100 fL Sideroblastic anemia would cause an increase in serum iron and ferritin. Reference: Harrison's Principles of Internal Medicine, 21 st Ed, Ch:97 Pg:752