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N-acetyl-beta-glucosaminidase (NAG) activity, the concentrations of microalbumin (MA) and B2-microglobulin (B2-MG) were measured in urine of 50 healthy subjects and 200 patients suffering from arterial hypertension (AH) with preserved renal function, including patients with essential hypertension (EH), stages I and II, chronic pyelonephritis (CPN), chronic glomerulonephritis (CGN) and vasorenal hypertension (VRH). The healthy subjects, the patients with stage II EH, and those with secondary forms of AH demonstrated significant differences in NAG activity in urine. A positive correlation (r = +0.53; p < 0.03) was discovered between systolic AP and NAG activity in urine of EH patients. The concentration of MA in urine of CGN and VRH patients was significantly higher than that in the healthy subjects, EH and CPN patients. The patients with CPN and VRH showed significantly higher levels of B2-MG in urine.

Overall 42 normotensive patients suffering from type I diabetes mellitus without proteinuria were examined for the effect of hyperfiltration on renal glomerular function and for changes in glomerular function seen during medicamentous treatment of hyperfiltration. Glomerular function was evaluated from the basal level of glomerular filtration (GF), the status of filtration reserves (i. e. according to the dynamics of the GF level in response to oral protein administration), and from the magnitude of albuminuria. Three groups of diabetes mellitus patients were distinguished: with filtration reserves, with decreased filtration reserves, and with no reserves. All the three groups did not differ in the age, diabetes standing or the degree of carbohydrate disorders compensation (HBA1c). Still, the patients with no filtration reserves significantly differ from the other groups with a high level of GF and albuminuria. In 9 patients, a study was made of the effect produced by captopril (an inhibitor of the angiotensin-transforming enzyme) on filtration reserves and albuminuria. After 3 to 6 months of the treatment five patients with no filtration reserves manifested a fall of the basal level of GF down to normal, the recovery of filtration reserves, and a decline of albuminuria. It is assumed that elimination of hyperfiltration due to the treatment with the inhibitors of the angiotensin-transforming enzyme may be an effective means of diabetic nephropathy prevention.

A review of data concerned with studies on low molecular weight RNA, a rapidly developing field of molecular biology and bioorganic chemistry, is given. The analytical approach allowed to estimate the initial steps of establishment of the problem, to determine the geographical distribution of these studies at present, to reveal the main laboratories involved and to give prognosis on future development.

A microsomal preparation with a high ability for Ca2+ uptake has been isolated from pigeon heart. A method of further purification of Ca2+-accumulating system of heart, based on the ability of sarcoplasmic reticulum for the energy-dependent Ca2+ accumulation in the presence of oxalate, has been developed. Upon centrifugation in the gradient of sucrose and KCl concentration the fragments of sarcoplasmic reticulum, rendered "heavy" by calcium oxalate, can be separated from foreign cell membranes. The main component of heart "calcium pump" is Ca2+-dependent ATPase (making up to about 50% of all proteins of the purified reticulum), having a molecular weight of 100.000--105.000. Specific activity of heart Ca2+-ATPase as well as the ability of purified heart sarcoplasmic reticulum for Ca2+ uptake are only slightly less than those of the skeletal muscle reticulum. The data obtained suggest that heart sarcoplasmic reticulum may be efficient for providing heart muscle relaxation.

alpha-Amylase isozymes were separated by electrophoresis in cellulose acetate to detect the isoforms of the chromogenic substrate manufactured by Lachema, Czechoslovakia. In a group of 20 normal subjects aged 25 to 45, alpha-amylase pancreatic isozyme activity prevailed. Patients with acute myocardial infarction developed, during 36 hours after the onset of the anginal attack, a reduction in the ratio of pancreatic amylase/salivary amylase activities in both increased and normal total alpha-amylase activities. The suggested modified technique of electrophoretic separation of alpha-amylase isozymes may become an effective method for differential diagnosis. Use of this method will help locate the source of hyperamylasemia in various diseases and will thus specify the diagnosis, ruling out the useless therapy for pancreatitis.

The blood serum alpha-amylase activity has been measured in normal male subjects by three methods, i. e. amyloclastic (W. Caraway's), with the use of the chromogenic insoluble substrate, and saccharogenic enzymic technique. The enzymic method has proved to be the most accurate and reproducible, whereas the amyloclastic one the least so. The enzyme activity values determined by the three methods are in poorly manifest though reliable correlation. The findings suggest that the data of the methods based on measurements of various parameters of the enzyme are not fully compatible.

The authors suggest a kinetic method for measuring the blood serum and urine creatinine by Jaffe's test. The method is highly specific, requires little biologic material, and rules out the deproteinization procedure. The specificity of the measurement is effected by selecting the period of time when it is creatinine that reacts with alkaline picrate. A thorough selection of the reaction mixture components and of the order of their addition helps minimize the interference of the substances reacting with alkaline picrate during the same period. The method is adapted to biochemical analyzers.

The authors compare the results of vanillylmandelic acid (VMA) excretion measurements by high-voltage electrophoresis on paper and by microelectrophoresis on cellulose acetate. Transverse scanning of electrophoregrams has been used for quantitative evaluation of the results of microelectrophoregrams on cellulose acetate. The results of VMA excretion measurements by the two methods have been in good correlation: r = 0.93, n = 15, y = 0.17 + 0.78x, p less than 0.01. Electrophoresis on cellulose acetate is three times less labor consuming and can be performed with Soviet equipment and maintenance medium. The excretion intensity can be assessed visually by reference values of VMA concentration.