Myoadenylate deaminase (adenosine monophosphate deaminase--AMPDA) was recently shown to be deficient in a group of patients by use of a histochemical and biochemical method based on the elaboration of ammonia by this enzyme as it deaminates 5' AMP. We have confirmed the utility of this histochemical method and the existence of persons deficient in AMPDA through the use of an unrelated assay technique. The lack of enzyme activity is not associated with any inhibitory activity in the muscles of patients with this disorder. The clinical diversity of these patients suggests that this lack may represent a normal variant or a subclinical state rather than an actual disease. The occurrence of AMPDA deficiency in both sexes points to possible autosomal inheritance.
The gas chromatographic behavior of 1 1 chlorinated hydrocarbons was studied on six columns and at four temperatures for possible qualitative and quantitative applications. Paraffin and Apiezon L columns gave good qualitative and quantitative performances. Peak area measurements were accurate to ±0.02 µ ß in the 0to 5-µ ß range. Carefully measured specific retention volumes made possible the calculation of partition coefficients, activity coefficients, and excess
Regulation of circulating iron is important in bacterial, yeast, and fungal infections. In the present study, cerebrospinal fluid levels of ferritin, an iron-binding protein, were determined in controls and in patients with central nervous system pyogenic and viral infections. Among 441 controls, cerebrospinal fluid ferritin level was higher than 18 ng/mL in two relapsed patients with central nervous system leukemia, 12 with bacteremia or pneumonia, and one with hemorrhagic herpes simplex encephalitis. Cerebrospinal fluid ferritin levels were more than 18 ng/mL in 13 of 63 patients diagnosed with nonhemorrhagic aseptic meningitis/ventriculitis, when defined solely by negative cerebrospinal fluid culture. Conversely, cerebrospinal fluid ferritin exceeded 18 ng/mL in culture-proven meningitis (46 of 47 cases) and ventriculitis (five of five cases). Cases of indolent cryptococcus and tuberculous meningitis showed modest increases despite traditional cerebrospinal fluid markers, at times, being normal. Cerebrospinal fluid ferritin levels did not correlate with cerebrospinal fluid neutrophil count, cerebrospinal fluid protein concentration, serum ferritin level, or patient age. In 16 of 19 cases monitored sequentially during ongoing antibiotic treatment, levels remained over 18 ng/mL (average, 15.0 days; range, 1 to 54 days). This observation suggests that obtaining cerebrospinal fluid ferritin levels is helpful whenever traditional laboratory benchmarks normalize, as during acute or chronic antibiotic therapy, or create confusion with positive cultures stemming from sample contamination.
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