Isolation and fluorometric determination of homovanillic acid in urine and tissues

The fluorometric method is described for determination of the final product of dopamine metabolism homovanillic acid in urine, amniotic fluid and tissue extracts. The metabolite was isolated using three chromatographic columns (1-Amberlit CG-50, 2-Dowex AG 1 x 2, 8-Aluminium oxide). Oxidation of eluates to emitter was done with potassium ferricyanide in alkalic medium. The use of internal standards made high recovery of compound and a good specificity and sensitivity of detection.     

Urine selenium level in healthy adult population

The level of urine selenium in healthy adult population, 230 persons, was examined. Persons were selected regarding sex, ages, and smoking habits. No differences versus these observations have been found. For a total, group values are 16.96 Se nmol/creatinine mmol, SD=5.44. It is possible from a single-void specimen to express daily excretion of selenium.     

Decarboxylation of branched-chain alpha-ketoacids in hepatocytes from alloxan-diabetic rats. The effect of insulin

The flux through branched-chain alpha-ketoacid dehydrogenase and the activity of the branched-chain alpha-ketoacid dehydrogenase complex were measured in hepatocytes isolated from fed, starved and alloxan diabetic rats. The highest rate of branched-chain alpha-ketoacid oxidation was found in hepatocytes isolated from starved rats, slightly lower in those from fed rats, and significantly lower in diabetic hepatocytes. The amount of the active form of branched-chain alpha-ketoacid dehydrogenase was only slightly diminished in diabetic hepatocytes, whereas the flux through the dehydrogenase was inversely correlated with the rate of endogenous ketogenesis. The same was observed in hepatocytes isolated from starved rats when branched-chain alpha-ketoacid oxidation was measured in the presence of added oleate. In both cases the diminished flux through the dehydrogenase, restored by a short preincubation of hepatocytes with insulin, was paralleled by a decrease of fatty acid-derived ketogenesis. The significance of these findings is discussed in relation to the role of insulin in branched-chain alpha-ketoacid oxidation in liver of diabetic rats.     

Phagocytosis activity of monocytes and macrophages in patients with plasmacytoma

The capacity to phagocytosis in monocytic macrophages was investigated in 24 patients with plasmocytoma. The investigation of this capacity was made by using short-term cultures with sheep erythrocytes loaded with antibodies and complement. In comparison to the control group the percentage of phagocyting macrophages was lowered in 16 from 24 patients. This impairment of the function of monocytic macrophages seems to be bound neither to the type of plasmocytoma nor to the stage of disease. Among other things, the nature of cell defect is discussed. The necessity of further investigations is emphasized.     

Sensitivity of insect ovarian tissues to various pteridines as tested in tissue culture

The effect of pteridine derivatives and analogues on the cell outgrowth from the ovarian explants of the waxmoth, Galleria mellonella, was examined in hanging-drop cultures and cytochemical tests were made for succinate and glucose-6-phosphate dehydrogenases. Most of the derivatives and analogues of 2-amino-4-hydroxypteridine injured to a lesser or greater extent insect ovarian tissues in vitro, depending on the drug structure and the concentration applied. Of all the pteridine derivatives and analogues tested only 2-amino-4-mercaptopteridine and its C-6,7-dimethyl derivative (10 μM) promoted cell outgrowth from the explants as did folate.