Ethambutol and a false-positive screening test for phaeochromocytoma.

Ethambutol and a false-positive screening test for phaeochromocytoma.

A screening test for phaeochromocytoma.

Patients suffering from phaeochromocytomata excrete many times the normal amount of noradrenaline in the urine (Euler, 1951). Determination of the excretion of noradrenaline in thu urine over 24 hours is thus a valuable aid to the diagnosis of this condition. Few clinical laboratories, however, have the facilities for noradrenaline assay, and there is a need for a simple, reliable, and fairly r...

Factors predicting a positive pregnancy screening test at first trimester

Background: For every pregnant woman, it is possible to have a child with chromosomal abnormalities. Although this possibility is not very high, by performing screening tests and considering the mother's background factors, we can largely realize the real extent of this possibility. Many comorbidities (like high blood pressure, diabetes, and obesity) and high-risk exposures (like alcohol consu...

Frequency of false positive responses in patients with multiple positive reactions in patch test

Background and aim: Contact dermatitis is an inflammatory skin response due to contact with environmental materials manifested as acute or chronic eczema. Patch test is the standard test to recognize responsible allergen. The objective of this study was to evaluate the frequency of false positive patch test responses in patients with Exited Skin Syndrome (ESS).Materials...

False Positive Reaction Due to Methocarbamol in the Screening Test for Vanilmandelic Acid (vma).

I N PHEOCHROMOCYTOMA, 3-methoxy-4-hydroxy-rnandelic acid (VMA), a metabolite of epinephrine and norepinephrine, is excreted in urine in abnormally large quantities. Qitlow et al. (1) have developed a semi quantitative screening method for VMA that we have found to be useful and reliable. The procedure is particularly welcome because it permits screening of a large number of urines from hyperten...