Analysis and HPLC fractionation of urine from patients with cystic fibrosis, chronic lung diseases and normal controls.

The amounts of creatinine, protein, carbohydrate and sialic acid in the urine of 19 patients with cystic fibrosis (CF), 12 normal controls and 11 pathological controls with chronic lung disease have been determined. The mean creatinine excretion levels of the total CF group as well as the CF subgroups are significantly decreased when compared to normal controls but comparable to pathological controls. Mean urinary protein levels appear to be increased in patients with CF compared to normal controls and pathological controls but the increased levels resulted from factors (e.g., presence of diabetes mellitus) other than CF. No significant differences were found in amounts of total carbohydrate and sialic acid in urine and fractionated urinary preparations for the total group of nondiabetic patients with CF when compared to both normal and pathological controls. HPLC fractionation of low Mr (less than 10,000 Daltons) urinary preparations indicated the presence of an unknown peak in all of the antibiotic-treated CF patients, 43% of CF patients on low or no medication, 17% of the normal controls and 9% of the pathological controls. The present results illustrate the importance of including appropriate pathological controls and dividing patients with CF into subgroups according to clinical factors and types of therapy employed.

Regulation of protein synthesis in zoospores of Blastocladiella.

The factors responsible for the regulation of protein synthesis in the zoospores of Blastocladiella emersonii were studied by means of cell fractionation and in vitro assays. Charged transfer ribonucleic acid (tRNA) and aminoacyl-tRNA synthetases were found both inside the membrane-bound, ribosomal nuclear cap, and in the extracap cytoplasm. Ribosomes isolated from zoospore nuclear caps in low salt buffer failed to support polyuridylic acid-dependent phenylalanine incorporation. After washing with high salt buffer, the cap ribosomes were equivalent in activity to similarly prepared plant ribosomes. Both the high-salt wash from cap ribosomes and the extracap supernatant fraction contained an unidentified material which inhibited aminoacyl-tRNA binding and peptide bond formation by ribosomes. Ribosomal binding of polyuridylic acid was not inhibited. Washed cap ribosomes supported very low incorporation rates without added messenger RNA, and were highly dependent upon added poly U for phenylalanine incorporation, indicating a low level of messenger in nuclear caps. It is concluded that enclosure of the ribosomes in the nuclear cap does not in itself prevent protein synthesis, and that the lack of activity may be due to the presence of a ribosome inhibitor.