Review of the structural and functional brain changes associated with chronic kidney disease.

Chronic kidney disease (CKD) leads to profound metabolic and hemodynamic changes, which damage other organs, such as heart and brain. The brain abnormalities and cognitive deficit progress with the severity of the CKD and are mostly expressed among hemodialysis patients. They have great socio-economic impact. In this review, we present the current knowledge of involved mechanisms.

Determination of bending-induced strain in optical fibers by use of quantitative phase imaging.

Quantitative phase microscopy with polarized light has been used to determine the change in refractive index introduced into an optical fiber when the fiber is bent through a constant radius of curvature. By obtaining phase images for two orthogonal directions of the polarization of the incident light, one can infer the induced axial strain profile within the fiber. Radii of curvature from 1 to 8 cm were considered, and in each case excellent agreement, within lambda/100, was obtained between experimental results and theory.

Plasma beta-thromboglobulin in acute myocardial infarction with ventricular arrhythmias.

Patients with myocardial infarction, complicated by ventricular arrhythmias (Lown grade greater than or equal to 2), had higher (p less than 0.05) plasma beta-thromboglobulin level than that found in patients with uncomplicated infarction. This indicates higher platelet activation in the former group than in the latter. Such data provide rationale for clinical trial of antiplatelet drugs in cases of myocardial infarction complicated by severe arrhythmias.

The effect of some 8-aminoalkanol derivatives of theophylline on cardiovascular system.

Novel 7,8-disubstituted theophyllines 1-6a, with chiral or achiral moiety of 1,2-aminoalcohol in position 8, were obtained as the compounds with expected activity on circulation. Preliminary evaluation of their antiarrhythmic activity and the effect on the cardiovascular system was carried out. The antiarrhythmic activity similar to that of quinidine (with ca. 20 times lower toxicity) was found only for racemic 7-beta-hydroxyethyl-8-(1'-hydroxybut-2'-yl) aminotheophylline 1 and its enantiomers 2, 3 which did not differ markedly in their efficacy. The compounds with the hydroxyethyl moiety in position 7 of theophylline (1-3, 5) showed the hypotensive effect.

Angiogenesis: quantitative assessment by the chick chorioallantoic membrane assay.

The aim of the present work was to improve quantitative assessment of angiogenesis by chick chorioallantoic membrane (CAM) assay based on measurement of DNA synthesis. Following incubation of [3H]thymidine (3H-T) with CAM in vivo, incorporation of 3H-T to DNA fraction was expressed as percent of total 3H-T present in the initial homogenate of CAM, regardless of CAM weight and full recovery of applied radioactivity. The assay required simple, partial isolation of DNA to remove traces of free or unspecifically bound 3H-T. These modifications gave a reproducible assay with adequate precision (10-20%). DNA content of CAM did not change between 10-15 days of embryo development and growth of CAM was completed on day 11. 10 to 12-day old CAMs were used for evaluation of the assay. Using a qualitative approach (visual scoring), tissues of several tumors were implanted on CAM. Extracts of tumors that produced the highest score stimulated DNA synthesis in CAM. A similar effect was induced by EGF while cytostatics inhibited DNA synthesis in CAM. Since stimulation of angiogenesis is not a cell type-specific phenomenon, the assay in the present modification should aid the studies on angiogenic factors. With the help of this assay the angiogenic activity of adenocarcinoma of human endometrium was described.

New derivatives of amino alcohols with antiarrhythmic activity.

Nine new N-acyl derivatives of 2-amino-1-alcohols and 1-amino-2-alcohols with a potential arrhythmic activity have been obtained. In the preliminary screening 2-[N-(7-theophyllineacetyl)-amino]-2-methyl-1-propanol, 5, was more active in the chloroform-induced arrhythmia than quinidine. Unlike to propranolol and quinidine, compound 5 in doses of 5-30 mg/kg, iv, did not prevent distortions of the cardiac rhythm evoked by adrenaline and strophanthine. When administered at the peak of arrhythmia, it did not abolish disturbances of the cardiac rhythm. Compound 5 had a low toxicity (LD50 = 3000 mg/kg, ip), did not change the control ECG curve, showed no cardiodepressive activity, and had weaker local anesthetic properties than lignocaine.

Derivatives of 2-N-arylalkylamino-2-methyl-1-propanol with antiarrhythmic activity.

Several aryl derivatives of achiral 2-amino-2-methyl-1-propanol have been obtained and tested for prophylactic and curative activity in different types of experimental arrhythmia. Interesting results were obtained for compounds 3 and 4 with activity and toxicity similar to those of quinidine.