CMT Urinalysis and Body Fluids Flashcards

An infant's urine gives a positive Clinitest (copper reduction) but a negative glucose oxidase strip. Which condition should be investigated?

Answer: Galactosemia

A non-glucose reducing sugar such as galactose reacts with copper reduction but not the glucose-specific oxidase pad.

Urine bilirubin is positive and urine urobilinogen is decreased. This pattern is most consistent with:

Answer: Bile duct obstruction

Obstruction lets conjugated bilirubin reflux into urine while blocking its delivery to the intestine, so less urobilinogen forms.

Oval fat bodies showing Maltese cross formations under polarized light are characteristic of which disorder?

Answer: Nephrotic syndrome

Lipiduria with cholesterol-containing oval fat bodies is a hallmark of nephrotic syndrome.

A semen sample from an azoospermic patient has a low volume and a negative fructose test. This suggests:

Answer: Absence or obstruction of the seminal vesicles

Fructose is produced by the seminal vesicles, so its absence indicates their absence or ejaculatory duct obstruction.

Which amniotic fluid lecithin/sphingomyelin (L/S) ratio generally indicates fetal lung maturity?

Answer: 2.0 or greater

An L/S ratio of 2.0 or higher indicates adequate surfactant and low risk of respiratory distress syndrome.

Colorless, flat hexagonal crystals are seen in an acidic urine sediment and confirmed with the cyanide-nitroprusside test. They indicate:

Answer: Cystinuria

Cystine crystals are hexagonal plates in acid urine and signal an inherited defect in amino acid reabsorption.

Oligoclonal bands present in CSF but absent in the matched serum on electrophoresis most strongly suggest:

Answer: Multiple sclerosis

CSF-restricted oligoclonal bands indicate intrathecal IgG synthesis, typical of multiple sclerosis.