Angiotensin-converting enzyme activity in human aqueous humor.

We measured aqueous angiotensin-converting enzyme (ACE) activity in 37 patients. Patients with granulomatous uveitis and probable sarcoidosis (based on increased serum ACE activity or characteristic radiologic findings) had a significant increase in aqueous ACE activity compared with normal subjects. Aqueous ACE activity was also significantly elevated in patients with sarcoid who had normal serum ACE activity.

Determination of 4-methylumbelliferone after separation from its conjugates by high-performance liquid chromatography. Application to lysosomal enzyme activity assays.

A high-performance liquid chromatographic method is described for the separation and estimation of 4-methylumbelliferone in the presence of its conjugates. The technique utilizes a simple, isocratic eluent and fluorometric detection. Percentages of 4-methylumbelliferone in the conjugates and fluorescences of the conjugates are reported.

Gyrate atrophy of the retina and choroid. Two methods for prenatal diagnosis.

We report two methods for prenatal diagnosis of gyrate atrophy of the retina and choroid caused by an inborn error of ornithine aminotransferase activity. A high pressure liquid chromatography assay measures ornithine aminotransferase accurately and directly in cultured amniotic fluid cells. The differential incorporation of 14C-ornithine and 3H-leucine into cell protein measures OAT directly but rapidly and simply.

Measurement of pilocarpine and its degradation products by high-performance liquid chromatography.

An assay method for pilocarpine using reversed-phase high-performance liquid chromatography is presented. This method also measures isopilocarpine, the stereoisomer of pilocarpine, and the degradation products pilocarpic acid and isopilocarpic acid. Maximum sensitivity was obtained with optical absorbance at 216 nm.

Angiotensin-converting enzyme in sarcoid uveitis.

The diagnosis of ocular sarcoid is presumptive in the absence of systemic disease. The association of elevated serum angiotensin-converting enzyme (ACE) levels with active systemic sarcoid has been well described. With a sensitive fluorimetric assay for ACE, we found that five of ten chronic granulomatous uveitis patients without systemic sarcoid had elevated serum ACE levels.

Glycosaminoglycan accumulation with partial deficiency of beta-glucuronidase in the C3H strain of mice.

Young (60--80 days) mice of the low beta-glucuronidase strain, C3H/HeJ, showed no differences in hepatic levels of glycosaminoglycans (GAGs) when compared to the randombred, "normal" Swiss-Webster mice of the same age. However, by 12 months of age hepatic GAG is nearly twice as high in C3H/HeJ mice as in Swiss-Webster mice. Studies of beta-glucuronidase, beta-galactosidase, and N-acetyl-beta-glucosaminidase in four tissues of the two types of mice at the two ages revealed that glucuronidase was the only enzyme with lower activity in the C3H/HeJ strain.

Gyrate atrophy of the retina: inborn error of L-ornithin:2-oxoacid aminotransferase.

Cultured fibroblasts from a patient with gyrate atrophy of the retina do not convert L-ornithine, uniformly labeled with carbon-14, to proline. This metabolic block is caused by deficient L-ornithine:2-oxoacid aminotransferase activity in the patient. Her heterozygote father has intermediate activity of this enzyme.

A new variant mucolipidosis: biochemical investigations on two siblings.

Biochemical studies are presented on two siblings with some features of Mucolipidosis III, but with distinctive clinical findings. Levels of beta-galatosidase, alpha-mannosidase, beta-glucuronidase, N-acetyl-beta-glucosaminidase and alpha-fucosidase found in serum from these patients ranged from 10 to 10 times higher than normal. The ratio of heat stable to heat labile serum isoenzymes of N-acetyl-beta-glucosaminidase is considerably greater than normal.

Nucleoside-phosphorylase deficiency in a child with severely defective T-cell immunity and normal B-cell immunity.

A 5-year-old girl with a history of recurrent infection and anaemia has no measurable purine nucleoside phosphorylase (N.P.) activity in her red blood-cells.