The molecular structure and multifunctionality of the cryptic plant polymer suberin.

Suberin, a plant polyester, consists of polyfunctional long-chain fatty acids and glycerol and is an intriguing candidate as a novel antimicrobial material. We purified suberin from cork using ionic-liquid catalysis during which the glycerol bonds that ensure the polymeric nature of suberin remained intact or were only partially cleaved-yielding the closest to a native configuration reported to date. The chemistry of suberin, both in situ (in cryogenically ground cork) and ex situ (ionic-liquid extracted), was elucidated using high-resolution one- and two-dimensional solution-state NMR analyses. Centrifugation was used to isolate suberin particles of distinct densities and their monomeric composition, assembly, and bactericidal effect, inter alia, were assessed. Analysis of the molecular structure of suberin revealed the relative abundance of linear aliphatic vs. acylglycerol esters, comprising all acylglycerol configurations and the amounts of total carbonyls (C[bond, double bond]O), free acid end groups (COOH), OH aliphatics, and OH aromatics. Suberin centrifuged fractions revealed generic physiochemical properties and monomeric composition â€‹and self-assemble into polygonal structures that display distinct degrees of compactness when lyophilized. Suberin particles-suberinsomes-display bactericidal activity against major human pathogenic bacteria. Fingerprinting the multifunctionality of complex (plant) polyesters such as suberin allows for the identification of novel polymer assemblies with significant value-added properties.

Protective effects of osajin in ischemia-reperfusion of laboratory rat kidney.

The aim of this study was to analyze the antioxidative effect of osajin during prophylactic administration. The pathological model for in vivo experiment was the unilateral ischemia-reperfusion of kidney of the laboratory rat. The animals were randomly divided into five groups. Osajin was administrated orally in doses of 5, 10 and 20 mg/kg once a day to three premedicated groups. Placebo--0.5% solution of Avicel--was given to the fourth group and the fifth group was completely intact. The premedication lasted 15 days and subsequently the ischemia of the left kidney was incited in general anaesthesia for 60 min. The reperfusion lasted 10 min and it was finished by blood collection from the left ventricle and the reperfused kidney was recovered. Selected biochemical markers were assessed in blood: superoxide dismutase, glutathion peroxidase, total antioxidative capacity and malondialdehyde. The kidney tissue samples were used for histopathological examination. Laboratory and histopathological results confirmed supposed effects of osajine. The dependence between the effect and the applied dose of osajin was linear. The best biochemical results were reached after administration of osajin at the dose of 5 mg/kg. The best histopathological results were reached after administration of osajin at the dose of 10 mg/kg.

[Morin in the therapy of the ischemia-reperfusion damage model of the rat kidney]. / Morin v terapii ischemicko-reperfuzního poskození ledvinné tkáne laboratorního potkana.

The aim of this study was to analyze the protective effects of morin administered during the therapy of reperfusion injury of the laboratory rat kidney. Animals were randomly divided into five groups (n= 10). One group was left intact. Three medicated groups and one placebo group were subjected to ischemia (60 min) and reperfusion of the left kidney. Morin was suspended in a 2 ml of 0.5% Avicel solution and administered orally by a gastric probe at doses of 5, 10, and 20 mg.kg(-1) once a day for 15 days. The placebo group was given only 2 ml of 0.5% Avicel in the same way. On the 15th day, all the animals were exsanguinated and the reperfused kidneys were recovered. Selected biochemical markers in blood were assessed: superoxide dismutase, glutathion peroxidase, total antioxidative capacity, malondialdehyde, creatinine, urea, and uric acid. Creatinine, urea, and total protein were analyzed in urine, and a 24-hour diuresis was recorded. The kidney tissue samples were used for histopathological examination. Morin supported the organism's own defensive reactions against free radicals and decreased lipid peroxidation in the cell membranes and contributed to the recovery of kidney functions. The histopathological results confirm 20 mg x kg(-1) as the most effective dose.

[Prophylactic administration of homoisoflavonoid in ischemic-reperfusion damage of the renal tissue in the laboratory rat]. / Profylaktické podávání homoizoflavonoidu u ischemicko- reperfuzního poskození ledvinné tkáne laboratorního potkana.

The study aimed to examine the antioxidizing effect of homoisoflavonoid in prophylactic administration under the conditions of renal ischemia-reperfusion in the laboratory rat. The pathological model for the in vivo experiment was unilateral renal ischemia-reperfusion of the laboratory rat. The animals were randomized into 5 groups. Homoisoflavonoid was administered to treated groups orally in doses of 5, 10 and 20 mg/kg once a day in 0.5% Avicel solution. The placebo group received Avicel only, and the intact group was without medication and intervention. On day 15 of the experiment, renal tissue ischemia/reperfusion (60/10 mins) was induced in the treated and placebo groups. Then the animals were exsanguinated, biochemical parameters in the blood (superoxidismutase, glutathionperoxidase, total antioxidizing capacity and malondialdehyde) were assayed, and renal samples were withdrawn for histopathological examination. A biochemical examination demonstrated a dependence of the effect of homoisoflavonoid on the dose administered. An obvious effect was demonstrated in the values of GSHPx, AOC, and MDA. On the other hand, a negative dependence was found between the dose of administered homoisoflavonoid and SOD and GSHPx values. The results of biochemical examination correlate with the histopathological pictures of the renal tissue and support the assumption about a protective effect of homoisoflavonoid under the conditions of artificially induced pathological state--renal tissue ischemia-reperfusion.

[Testing bradycardial effects of a newly synthesized ultra-short beta blocker in laboratory rats]. / Testování bradykardického úcinku nove syntetizovaných potenciálních ultrakrátkých beta blokátoru na laboratorním potkanovi.

With the use of normotensive laboratory Wistar strain rats, changes in heart rate induced by three newly synthesized potential ultrashort beta-blockers were tested. The animals were administered the tested substances intravenously in general anesthesia. In all animals, heart rate was measured at predetermined time intervals. All obtained values were converted into the per cents of the heart rate deviation and the results were statistically processed. Using F-test, variability of dispersion was determined, and using Student t-test, statistical significance of the particular change was determined. In all three substances tested, a statistically demonstrable short-time bradycardiac effect was observed. The most marked decrease took place in the first minute after intravenous administration. Substance 44Bu induced the significantly deepest decrease in heart rate (by 13.00%), which lasted longest. No statistically significant difference was found between the actions of substances 42Bu and 43Bu. In all three substances tested, marked changes in the ECG record were observed immediately after intravenous administration. PQ and QT intervals and QRS complex were prolonged, and marked S wave, elevation of the T wave, and a decrease in R wave occurred. The changes were accompanied by a change in the electric cardiac axis.

Color sensitive retina based on bacteriorhodopsin.

Bacteriorhodopsin (BR), a membrane protein of a microorganism Halobacterium salinarium has been studied since the 80's as a potential material for information technology. The information processing applications of BR employ either photochromic or photoelectric properties of the protein. In this study we discuss about design principles and describe our study of the use of bacteriorhodopsin as a sensor material for a color sensitive artificial retina. This retina includes low-level processing of input information. The design of a color sensitive matrix element, the self-organizing color adaptation algorithm and a system model for the retina are presented.

Color recognition with bacteriorhodopsin.

We have studied opto-electric properties of wild type bacteriorhodopsin and its two artificial variants. We have measured opto-electric responses with respect to wavelength for all three proteins and we describe the use of the proteins for color detection. Opto-electric responses of proteins to set of colored lights were measured and it has been shown that bacteriorhodopsin and its variants can be used to recognize color. A simple equation for estimating opto-electric response to arbitrary spectrum is given.