Infective endocarditis caused by unusual gram-positive pathogens

Of a total of 81 patients hospitalized in the infectious diseases department in 1990–2000 with infectious endocarditis caused by Gram-positive pathogen, unusual etiological agents were found in several cases:Streptococcus pyogenes, Streptococcus pneumoniae, Corynebacterium diphtheriae, andGemella morbillorum. Cardiac defects were present in the latter two patients: bicuspid aortic valve and tetralogy of Fallot. Two patients were successfully treated with antibiotics only and one patient with antibiotics and surgery. The patient withC. diphtheriae endocarditis died due to progressive sepsis and multiple organ failure.     

Overexpression of glutamate-cysteine ligase extends life span in Drosophila melanogaster

The hypothesis that overexpression of glutamate-cysteine ligase (GCL), which catalyzes the rate-limiting reaction in de novo glutathione biosynthesis, could extend life span was tested in the fruit fly, Drosophila melanogaster. The GAL4-UAS binary transgenic system was used to generate flies overexpressing either the catalytic (GCLc) or modulatory (GCLm) subunit of this enzyme, in a global or neuronally targeted pattern. The GCL protein content of the central nervous system was elevated dramatically in the presence of either global or neuronal drivers. GCL activity was increased in the whole body or in heads, respectively, of GCLc transgenic flies containing global or neuronal drivers. The glutathione content of fly homogenates was increased by overexpression of GCLc or GCLm, particularly in flies overexpressing either subunit globally, or in the heads of GCLc flies possessing neuronal drivers. Neuronal overexpression of GCLc in a long-lived background extended mean and maximum life spans up to 50%, without affecting the rate of oxygen consumption by the flies. In contrast, global overexpression of GCLm extended the mean life span only up to 24%. These results demonstrate that enhancement of the glutathione biosynthetic capability, particularly in neuronal tissues, can extend the life span of flies, and thus support the oxidative stress hypothesis of aging.     

Utilization of newly developed immobilized enzyme reactors for preparation and study of immunoglobulin G fragments

The newly developed immobilized enzyme reactors (IMERs) with proteolytic enzymes chymotrypsin, trypsin or papain were used for specific fragmentation of high molecular-mass and heterogeneous glycoproteins immunoglobulin G (IgG) and crystallizable fragment of IgG (Fc). The efficiency of splitting or digestion were controlled by RP-HPLC. The specificity of digestion by trypsin reactor was controlled by MS. IMERs (trypsin immobilized on magnetic microparticles focused in a channel of magnetically active microfluidic device) was used for digestion of the whole IgG molecule. The sufficient conditions for IgG digestion in microfluidic device (flow rate, ratio S:E, pH, temperature) were optimized. It was confirmed that the combination of IMERs with microfluidic device enables efficient digestion of highly heterogeneous glycoproteins such as IgG in extremely short time and minimal reaction volume.     

What's in a name; Genetic structure in Solanum section Petota studied using population-genetic tools

Background  

The taxonomy and systematic relationships among species of Solanum section Petota are complicated and the section seems overclassified. Many of the presumed (sub)species from South America are very similar and they are able to exchange genetic material. We applied a population genetic approach to evaluate support for subgroups within this material, using AFLP data. Our approach is based on the following assumptions: (i) accessions that may exchange genetic material can be analyzed as if they are part of one gene pool, and (ii) genetic differentiation among species is expected to be higher than within species.     

Scats and den contents as indicators of the diet of stoats (Mustela erminea) in the Tasman Valley,South Canterbury,New Zealand

Stoats are significant predators of native fauna in New Zealand. They occur in many habitat types and consume a wide range of prey. The diet of stoats in the Tasman River, South Canterbury, was studied by analysis of scats and den contents. Analysis of 206 scats showed that stoats ate mainly lagomorphs, birds and invertebrates. Minor components included mice, lizards, fish and hedgehogs. Stoats ate more birds in spring than in autumn, and female stoats ate more invertebrates than did males. The contents of 219 dens collected in the same area at the same time provided further information. Birds and lagomorphs occurred at high frequency in dens, and other components were minor. Remains in dens were larger than in scats and allowed identification of many more prey items to species level. Den contents revealed a potentially substantial impact of stoats on threatened shorebirds locally; this impact was not detected by analysis of scats.     

Immunoaffinity reactors for prion protein qualitative analysis

The cellular prion protein (PrPc) represents the substrate for generation of conformational aberrant PrP isoforms which occur in human and animal prion diseases. The published two-dimensional maps of human PrPc show a vast microheterogeneity of this glycoprotein. The main goal of this project was to develop a highly specific immunoaffinity reactor for qualitative analysis of PrP cellular isoforms isolated from brain homogenate, cerebrospinal fluid and other tissues. New techniques for affinity proteomics, carriers and immobilization chemistry were applied. The choice of matrix (chemical and magnetic properties, particle size and distribution, porosity) was the key factor that influenced the quality of the reactor and the nature of final applications. Mouse anti-prion IgGs directed to N-terminal and C-terminal epitopes (residues 23-40 and 147-165) were grafted in different manners to magnetic micro- and nanoparticles particularly developed for micro-CHIP application. High operational and storage stability of affinity reactors with minimized nonspecific absorption were achieved. The quality of the immunoreactors was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting and by two-dimensional electrophoresis.     

Influence of antioxidant effect of stobadine derivative in condition of kidney ischemia-reperfusion in a pre-clinical experiment (effect in therapy)

The goal of the study was to monitor the antioxidative effect of stobadine derivative under conditions of ischemia-reperfusion of laboratory rat kidney tissue. 40 animals were subjected to kidney tissue ischemia (60 min) followed by reperfusion (10 min). After that, the animals were divided by random selection into 4 groups (n = 10). The treated groups were given stobadine derivative in peroral doses of 5, 10 and 20 mg/kg in 0.5% solution of Avicel once a day, the placebo group was given only the solution of Avicel. One group (n = 10) was an intact group (without ischemia-reperfusion and without treatment), for comparison. Once a week, selected laboratory parameters were determined in all animals. On the 15th day the animals were exsanquined and organs were recovered for histopathological examination. We discovered a statistically significant changes of the superoxiddismutase and glutathione peroxidase catalytic activity; changes of total antioxidative capacity and malondialdehyde in the treated groups compared to the groups of placebo and intact. Other examined laboratory parameters (creatinine, urea and uric acid in blood; creatinine, urea, total protein in urine; diuresis) exhibited significant changes too. The results of biochemical examination show a protective antioxidative effect of the compound studied. The results of histopathological examination support this assumption.     

Handedness of the herpes simplex virus capsid and procapsid

The capsid of herpes simplex virus has an icosahedral surface lattice with a nonskew triangulation number, T=16. Nevertheless, the proteins arrayed on this lattice necessarily have an intrinsic handedness. We have determined the handedness of both the herpes simplex virus type 1 capsid and its precursor procapsid by a cryoelectron microscopic tilting method.     

Properties of RNase A immobilized on magnetic Poly(2-hydroxyethyl methacrylate) microspheres

Magnetic hydrogel microspheres 1.5 microm in size were prepared by dispersion copolymerization of 2-hydroxyethyl methacrylate and ethylene dimethacrylate in the presence of magnetite, which formed the core of the particles. RNase A was coupled to the particles by the cyanuric chloride method. Gel electrophoresis of plasmid DNA pUC 19 (contaminated by bacterial RNA) confirmed RNA degradation with the immobilized enzyme. The effect of temperature and pH on the relative activity of immobilized RNase A was estimated after incubation of the samples at different temperatures (30-80 degrees C) and pH (4.0-8.0). Maximum relative activity was observed at 70 degrees C and pH 6.5. The matrices based on magnetic poly(HEMA) had a low tendency to adsorb RNA.     

Distribution patterns in butterflies and birds of the Czech Republic: separating effects of habitat and geographical position

Aim To evaluate the relative role of environmental factors and geographical position (latitude and longitude) in determining species distribution and composition of local assemblages of butterflies and birds. Location Czech Republic, central Europe. Methods Canonical correspondence analysis that ordinates species and samples (grid cells in distribution atlases) such that interspecific and intersample differences attributable to environmental factors are maximized. The technique allowed us to test the significance of individual factors, including the geographical ones, by controlling the other factors and accounting for spatial autocorrelation. Results Altitude and climate (temperature and precipitation) accounted for most variance in the interspecific differences in distribution of both butterflies and birds. The distribution of birds was also strongly affected by the area of water bodies, and less strongly, but still significantly, by the area of meadows and mountain open habitats. Habitat types important for the differences in butterfly distribution were deciduous forests, meadows, swamps and mountain open habitats. Some less common habitat types were important only because of the presence of rare species. Latitude and longitude invariably accounted for a large proportion of total variance, and their effect was highly significant even after controlling for the effect of all other environmental factors. Main conclusions Although environmental factors, especially those related to elevation and climate, represent the main determinants of species distribution and composition of local assemblages, the geographical position is very important on this scale of resolution. Understanding distribution patterns, thus, must include not only an understanding of species ecological requirements, but also an understanding of geographical context, which affects structure and dynamics of species’ geographical ranges.