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Biomedical subjects

J Slavík

Publications and source records attributed to J Slavík.

At least 19 recordsLinked to original sources
PubMed2005

Blood phagocyte activation during open heart surgery with cardiopulmonary bypass.

Open heart surgery with a cardiopulmonary bypass (CPB) is associated with a systemic inflammatory response which significantly contributes to adverse postoperative complications. The purpose of this study was to characterize the activation of blood phagocytes during open heart surgery with CPB. Blood samples were collected during and up to 24 h after surgery. The production of reactive oxygen species (ROS) in whole blood, the expression of surface molecules by blood phagocytes and complement activity in the plasma were determined. A cDNA microarray analysis of leukocyte RNA profile of genes was performed related to the inflammatory response. Activation of the complement was already observed at the beginning of CPB. This was followed by an increase in the neutrophil number and in both spontaneous and opsonized zymosan-activated ROS production after the onset of reperfusion. The activation of blood phagocytes was affirmed by changes in surface receptors involved in the adhesion and migration of leukocytes (CD11b, CD62L and CD31). Gene arrays also confirmed the activation of leukocytes 4 h after reperfusion. In conclusion, open heart surgery with a cardiopulmonary bypass was found to be associated with a rapid and pronounced activation of blood phagocytes and complement activation which was partly independent at the onset of CPB.

Aged↗
PubMed2001

Protopine hydrochloride.

Protopine hydrochloride (5,6,14,14a-tetrahydro-14a-hydroxy-7-methyl-8H-bis[1,3]benzodioxolo[5,6-a:4,5-g]quinolizinium chloride, C20H20NO5(+)-Cl(-)) is the salt of the isoquinoline alkaloid protopine. It is formed by the action of dilute hydrochloric acid on the protopine free base. The N-methyl and hydroxyl groups are in a trans configuration in the quinolizine ring and the central quinolizine N-C bond is unusually long [1.579 (2) A]. The crystal is a racemate.

Alkaloids↗
PubMed2001

(-)-Argemonine hemihydrate.

(-)-Argemonine hemihydrate [systematic name: (6S,12S)-2,3,8,9-tetramethoxy-13-methyl-13-azadibenzo[b,f]bicyclo[3.3.1]nona-2,6-diene hemihydrate], C21H25NO4.0.5H2O, is a tertiary pavinane alkaloid. Both partially saturated nitrogen heterocycles adopt twisted half-chair conformations. The angle between the two aromatic rings is 86.90 (5) degrees.

Alkaloids↗
PubMed1999

2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein as a dual-emission fluorescent indicator of intracellular pH suitable for argon laser confocal microscopy.

The widely used fluorescent probe 2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) serves as a pH-sensitive indicator in classical microscopy. Characteristics of BCECF were studied and a way of employing the probe in a confocal laser scanning microscope equipped with an argon laser at 488 nm was developed, based on the fact that the emission fluorescence spectra are pH-dependent with spectral maximum shift from 518 to 529 nm. Optical filters for the dual-emission ratio method were set to 506 and 529 nm. pH values measured inside a single cell of Saccharomyces cerevisiae were similar to those obtained with other pH estimation methods.

Argon↗
PubMed1998

Fusion of macrophages on an implant surface is associated with down-regulated expression of ligands for galectin-1 and -3 in the rat.

Galectins have a wide range of biological activities which are elicited by binding to appropriate glycoligands. Besides regulation of the expression of the galectins the extent of the presence of suitable binding sites will be relevant to infer the cellular responsiveness to this class of sugar receptors. Thus ligand presentation requires monitoring by the tissue lectin. We demonstrate the expression of galectin-3 by macrophages and foreign-body giant multinucleate cells colonizing a cellophane implant in the rat by the A1D6 monoclonal antibody. The extents of ligand presence are visualized in the same cells by biotinylated galectin-3 and also by galectin-1 which is produced by diverse mammalian cell types and widely distributed. Labeled mistletoe (VAA) and tomato (LEA) lectins are used as tools to assess the degree of similarity of the binding profile between endogenous and exogenous proteins. The presentation of alpha-galactosides is monitored with a natural immunoglobulin G subfraction obtained by two consecutive affinity chromatography steps. The binding of labeled galectins and plant lectins was significantly lower to foreign-body giant multinucleate cells than to mononuclear macrophages. The application of the alpha-galactoside-specific probe yielded no significant staining. The potential problem of epitope accessibility could be excluded by the concomitant positivity obtained with an IgG subfraction with selectivity to beta-galactosides also obtained by affinity chromatography. These results provide no evidence for a role of alpha-galactosides for the binding of galectins in the rat macrophages colonizing the implant. The reduced level of expression of glycoligands for galectin-1 and -3 in foreign-body giant multinucleate cells in contrast with the mononuclear macrophages suggests an inhibitory influence of macrophage fusion on the expression of galectin-reactive molecules.

Animals↗
PubMed1997

Measurement of membrane potential in Saccharomyces cerevisiae by the electrochromic probe di-4-ANEPPS: effect of intracellular probe distribution.

Changes in the membrane potential of Saccharomyces cerevisiae were monitored by the electrochromic probe 3-(4-(2-(6-(dibutylamino)-2-naphthyl)-trans- ethenyl)pyridinium)propanesulfonate (di-4-ANEPPS) that should incorporate into the plasma membrane. The probe had suitable spectral characteristics and exhibited an electrochromic shift upon a change in membrane potential but the magnitude of the response increased with time. The presence and properties of the cell wall affected the extent of cell staining. The time dependence of the fluorescent response indicated that the probe was not incorporated solely into the plasma membrane but spread gradually into the whole cell; this was confirmed by confocal microscopy. The probe is therefore suitable for assessing membrane potential changes only over time intervals up to 30 min. Longer monitoring will require either a modified staining protocol or a derivatization of the probe molecule. As found by using the dioctyl derivative di-8-ANEPPS, extending the aliphatic chains of the di-4-ANEPPS molecule does not prevent the dye from penetrating into the cell or liposome interior and, in addition, impairs staining.

Cell Membrane↗
PubMed1995

Distribution of individual cytoplasmic pH values in a population of the yeast Saccharomyces cerevisiae.

Fluorescence ratio imaging microscopy using pH-sensitive fluorescent dyes makes it possible to evaluate statistical distribution of intracellular pH in a population of the yeast S. cerevisiae examined in a thin layer of suspension in a Petri dish. The distribution appears to fit a Gaussian curve with a half-width around the 0.4 pH unit. The curve became slightly narrower after resuspension in a strong buffer; the mean values shifted with the pH of the buffer. The shape of the distribution curves of both resting and growing cells in various phases of growth does not change significantly. Likewise, addition of 1% of glucose, 50 microM suloctidil or 100 microM diethylstilbestrol brings about no alteration. The only value which clearly changes is the average cytoplasmic pH.

Cytoplasm↗
PubMed1994

[CADISO (Cardiovascular Diseases and Stability of the Organism): 10 years of integrated research on natural substances at the Charles University Pharmacy School in Hradec Králové].

The research project CADISO (Cardiovascular Diseases and Stability of the Organism--Phytotherapeutical Possibilities) is an alliance board associating approximately 20 professional institutions, its centre and coordinating laboratory being the Department of Pharmaceutical Botany and Ecology, Faculty of Pharmacy, Charles University, Hradec Králové. It aims at the prevention (additives in food industry) and therapy of diseases of the circulatory apparatus using phytotherapeutic agents and substances isolated from higher plants and fungi. The project is divided into three systems of investigation: ADAPRETE, i.e. the substances increasing the nonspecific resistance of the organism (adaptogenes of plant origin, immunostimulants), DIACORD, dealing with the substances acting on the cardiovascular system in a mediated way, i.e. treating the diseases the eventual action of which alters the heart and vessels (antihypercholesterolemics, antihyperlipidemics, antidiabetics, anti-oxidants and quenchers of free radicals, hepatoprotectives, anti-aggregating agents), and CORCORAN studying the taxons and substances isolated from them which act directly on the circulatory system (cardiotonic, anti-arrhythmic and vasodilating agents). To achieve a real purpose of the project, the linking-up of the phytochemical, pharmacological-toxicological, pharmaceutical-technological fields, production of raw materials and legislation is ensured.

Cardiovascular Diseases↗
PubMed1994

[Phytotherapeutic aspects of diseases of the circulatory system. III. Cardiotonic and cardiotoxic effects of hyrcanoside and deglucohyrcanoside isolated from Coronilla varia L].

The Cardiotonic and cardiotoxic effects of two cardiac glycosides-hyrcanoside and deglucohyrcanoside-isolated from the seeds of Coronilla varia L. were evaluated in the paper--in comparison with the effect and toxicity of digoxin and ouabain. Evaluation of the cardiotonic effect using the methods of heart "in situ" and the isolated heart (Langendorff) proved that deglucohyrcanoside is more effective than hyrcanoside and that its effect is equal to that of digoxin as well as ouabain. The efficacy of deglucohyrcanoside et least to that of digoxin, while the toxicity of the former is several times lower, makes the glycoside a potential candidate for therapeutic use.

Animals↗
PubMed1990

[Comparative study of the prevalence of disorders of impaired structure of dental tissues in school children and university students].

The authors examined a group of 573 Prague children aged 12-15 years. In addition to the incidence of disorders of the structure of dental tissues they investigated the coriosity (DPE), oral hygiene (OHI) and condition of the gingiva (PI). Their main interest was focused on impaired mineralization of dental tissues the incidence of which is indemic in Prague children. The group was compared with 62 university students. It is of interest that in all indicator except impaired mineralization, the children had significantly better results. The rising curve of impaired mineralization signalises the ever deteriorating living environment in the capital.

Adolescent↗
PubMed1990

[Analysis of environmental indicators in relation to structural disorders of dental tissues].

An epidemiological investigation revealed a high incidence of structural disorders of dental tissues in the child population of Prague. While hypoplastic disorders are steadily diminishing, there is an ever rising trend of hypomineralization. The observed disorders of hypomineralization are becoming a serious clinical problem. The aim of the present investigation was to assess to what extent exogenous harmful substances participate in the development of hypomineralization: infectious diseases, tetracycline antibiotics, excess fluorine intake and type of drinking water--from the water-mains or wells. The data were assembled by means of questionnaires. Two clinical investigations comprising 300 children, mean age 13 years, suggest that among the investigated indicators only the type of drinking water can be associated with the development of the observed changes. Children drinking from birth water from wells had significantly fewer disorders of mineralization than children who drank water from the water-mains. The submitted paper presents partial results of the state research plan of technical development.

Child↗
PubMed1987

Intracellular pH topography of Penicillium cyclopium protoplasts. Maintenance of delta pH by both passive and active mechanisms.

The intracellular pH distribution in protoplasts of Penicillium cyclopium has been studied using the recently developed fluorescent probe microscopic technique. The technique gives detailed pH maps of the interior of the protoplasts with the exception of vacuoles (no fluorescence signal from vacuoles was observed). In the cytoplasm two separate layers were distinguished: a thinner outer layer with acidic pH (around 5) and the larger core region with near neutral pH. The pH of the core region is decreased by the addition of uncouplers, inhibitors of respiration and during the uptake of L-phenylalanine. These compounds do not change the pH of the surface layer, which is, however, acidified by addition of vanadate, an inhibitor of the proton pump of the plasmalemma. We suggest that the pH of the surface layer is maintained by the combined effects of a Donnan distribution of protons (bound to postulated anion binding proteins) and the proton extrusion via the plasmalemma proton pump. This mechanism explains the protection of the cytoplasmic core of acidophilic eukaryotes from the influence of the usually acidic environment.

Hydrogen-Ion Concentration↗
PubMed1984

Intracellular pH distribution and transmembrane pH profile of yeast cells.

The pH-dependent fluorescence excitation of fluorescein located intracellularly and in the vicinity of cells of the yeast Saccharomyces cerevisiae and Endomyces magnusii was used to obtain local pH values at a linear resolution 0.2 micron. Cells suspended in water or in a diluted (5 mM) acidic buffer had a relatively alkaline interior (about 7.0-7.5) with pH decreasing gradually toward the periphery and further out through the cell wall to the value of the bulk solution. In slightly alkaline weak buffers the cells also showed an alkaline center and a slightly acidic ring-shaped area, but the peripheral region close to the membrane was again alkaline with pH increasing toward the bulk solution. The heterogeneity of intracellular pH was reduced or nearly abolished in starved or antimycin-treated cell. Suspension of cells in strong (200 mM) buffer resulted within 15-20 min in a nearly homogeneous pH pattern throughout the cell, attaining pH values of 5.5-7.5, depending on the pH of the buffer. Addition of glucose with concomitant pH decrease of the extracellular medium did not change appreciably the intracellular pattern for 20-30 min, except with diethylstilbestrol (inhibitor of proton-extruding ATPase) when the cell became more acidic. It appears that the delta pH measurements between the cell as a whole and the bulk solution (as are used for the calculation of the electrochemical potential of protons in proton-driven transports) are not substantiated, the probable pH difference across the plasma membrane being substantially smaller than previously supposed.

Ascomycota↗