A set of six polymorphic microsatellite markers was developed for the highly invasive horse chestnut leaf-mining moth, Cameraria ohridella. For 96 positive clones, six polymorphic microsatellites with conserved flanking regions were identified. The average number of alleles per locus was eight (range from three to 12). Two of these loci showed significant heterozygosity deficits due to null alleles. The remaining four loci did not depart from Hardy-Weinberg equilibrium. In addition, all six loci were amplified for 20 other gracillariid species belonging to eight different genera, including another invasive species Phyllonorycter platani. These are the first microsatellite markers described for a species within the lepidopteran family Gracillariidae.
Marssoniella elegans Lemmermann, 1900, a parasite of ovarial tissues of the copepod Cyclops vicinus Uljanin, 1875, was studied as a representative of aquatic-clade microsporidia which form ''heteroinfectious spores'' (spores not infective to the original host as opposed to ''homoinfectious spores'' which are infective for the original host) and which thus should require an alternate host. Several structural characters of this microsporidian are similar to those of copepod morphs of microsporidia infecting mosquitoes. However, small subunit ribosomal DNA phylogeny indicates that caddis flies (Insecta, Trichoptera) might be the alternate hosts of Marssoniella. Ultrastructural data obtained are used to redefine the genus Marssoniella Lemmermann, 1900 and its type species Marssoniella elegans.
The history of understanding xenoparasitic complexes or xenomas provoked in the host cell by various protists and especially by microsporidia is outlined. Microsporidia have been known to produce xenomas in oligochaetes (e.g., genera Bacillidium, Burkea, Hrabyeia, Jirovecia, species of the collective group Microsporidium), crustaceans (e.g., Abelspora, Mrazekia), insects (e.g., Polydispyrenia, Thelohania) and poikilothermic vertebrates, mostly fish (Alloglugea, Amazonspora, Glugea, Ichthyosporidium, Loma, Microfilum, Microgemma, Neonosemoides, Pseudoloma, Spraguea, Tetramicra). An overview of characters of xenomas caused by species of these genera is presented. The study of microsporidia causing xenomas in fish offers an insight into cell pathology and is of interest since many of these species are important agents of diseases in commercial fish. Xenomas produced from a few types of target cell display a complete change of organisation of the host cell and differ, according to the agent, in their structure. Recent data show that proliferation of the parasite may have already started in the cells transporting the parasites to the final site of xenoma formation. However, these are preliminary revelations and most of the facets of the life cycle are still to be clarified. Curiously, xenoma-forming microsporidia do not seem to be strictly host specific. The salient features of fish microsporidian xenomas are discussed, such as role of the xenoma, whether its features are host- or microsporidium-dependent, development and demise of the xenoma in the course of time, and host reaction phenomena. The need of further research is emphasised.
Microsporidiosis is an increasingly important opportunistic infection in HIV-positive patients. Five species of microsporidia {Enterocytozoon bieneusi, Encephalitozoon hellem and E. cunieuli, Seplata intestinalis, and Pleistophora sp.) have been reported to occur in AIDS, with each agent producing a different clinicopathologic spectrum of disease. This communication reviews routine and specialized methods for diagnosis of these important pathogenic protozoa, including biopsy, cytology, ultrastructural and immunologic examination, and tissue culture, and describes the current knowledge of organ distribution for microsporidia in persons with AIDS.
Differences in soil stability, especially in visually comparable soils can occur due to microstructural processes and interactions. By investigating these microstructural processes with rheological investigations, it is possible to achieve a better understanding of soil behaviour from the mesoscale (soil aggregates) to macroscale (bulk soil). In this paper, a rheological investigation of the factors influencing microstructural stability of riparian soils was conducted. Homogenized samples of Marshland soils from the riparian zone of the Elbe River (North Germany) were analyzed with amplitude sweeps (AS) under controlled shear deformation in a modular compact rheometer MCR 300 (Anton Paar, Germany) at different matric potentials. A range physicochemical parameters were determined (texture, pH, organic matter, CaCO3 etc.) and these factors were used to parameterize pedotransfer functions.
The results indicate a clear dependence of microstructural elasticity on texture and water content. Although the influence of individual physicochemical factors varies depending on texture, the relevant features were identified taking combined effects into account. Thus, stabilizing factors are: organic matter, calcium ions, CaCO3 and pedogenic iron oxides; whereas sodium ions and water content represent structurally unfavorable factors. Based on the determined statistical relationships between rheological and physicochemical parameters, pedotransfer functions (PTF) have been developed.
Considerable amount of waste in the form of polyethylene terephthalate (PET) bottles could be utilized in the form of dispersed microreinforcement in concrete. PET fibres, however, have poor wettability and adhesion to cement paste, which can be modified by alkaline hydrolysis with sodium hydroxide at elevated temperature. The alkaline treatment was used to increase fibre surface, which was followed by changes in the structure of the interfacial transition zone (ITZ) and interfacial bond between fibre and cementitious matrix. Raman microspectroscopy mapping was employed to study microstructural changes of ITZ within the distance 0 - 250 μm from a PET fibre. The band at 357 cm-1 corresponding to the Ca-O bond vibration in portlandite was used to determine its distribution. For determination of the relative abundance of ettringite, the SO42- stretching vibration at 987 cm-1 was used. The most intensive bands of portlandite and ettringite were found within the distance 0 - 50 μm from an unmodified PET fibre. Besides the elevated concentration of these minerals, abundant pores occur in this region. In the case of alkaline modified PET fibres the ITZ zone was not found., Vladimír Machovič, Ladislav Lapčák, Lenka Borecká, Miloslav Lhotka, Jana Andertová, Lubomír Kopecký and Linda Mišková., and Obsahuje bibliografii
Microscopic techniques, such as polarising microscopy and scanning electron microscopy with energy dispersive spectrometer (SEM/EDS), were used in combination with petrographic image analysis with the aim of a quantitative determination of the mineral composition, rock microstructure, and degree of metamorphism of selected quartz-rich metamorphic rock types. Sampled orthogneiss rock types are mainly composed of feldspar, quartz, biotite, and amphibole. The grains are less isometric, elongated, having smooth boundaries, and showing a weak preferential orientation. The deformation and recrystallization characteristics of quartz indicate high-temperature recrystallization (the grain boundary migration recrystallization mechanism). Schist and phyllite rock types are preferentially very-fine to fine-grained, showing a strong shape preferred orientation. Their sedimentary origin was indicated by the presence of graphite. The deformation and recrystallization characteristics of the quartz indicate low temperature conditions of their metamorphism., Šárka Šachlová, Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografii
In most macrovascular endothelial cell (EC) preparations, resting membrane potential is determined by the inwardly rectifying K+ current (IK1), whereas in microvascular EC the presence of IK1 varies markedly. Cultured microvascular EC from small vessels of human omentum were examined by means of the voltage-clamp technique to elucidate the putative role of IK1 in maintaining resting membrane potential. Macrovascular EC from human iliac artery and bovine aorta served as reference. Human omentum EC showed an outwardly rectifying current-voltage relation. Inward current was hardly sensitive to variations of extracellular [K+] and Ba2+ block suggesting lack of IK1. However, substitution of extracellular [Na+] and/or [Cl-] affected the current-voltage relation indicating that Na+ and Cl- contribute to basal current. Furthermore, outward current was reduced by tetraethylammonium (10 mM), and cell-attached recordings suggested the presence of a Ca2+-activated K+ current. In contrast to human omentum EC, EC from human iliac artery and bovine aorta possessed inwardly rectifying currents which were sensitive to variations of extracellular [K+] and blocked by Ba2+. Thus, the lack of IK1 in human omentum EC suggests that resting membrane potential is determined by Na+ and Cl- currents in addition to K+ outward currents., H. M. Himmel, U. Rauen, U. Ravens., and Obsahuje bibliografii
Impaired NO-dependent vasodilation of resistance vessels is an early marker of an increased risk of atherosclerosis; utility of the examination of microcirculation, however, is far less established. We have therefore tested the hypothesis that hypercholesterolemia is associated with an impaired microvascular reactivity and that this defect is at least partially reversible by lipid-lowering treatment. Twenty-seven otherwise healthy patients with severe hypercholesterolemia (HLP) were examined at rest and then after 10 weeks of atorvastatin treatment (20 mg/day). Skin microvascular reactivity (MVR) was examined by laser-Doppler flowmetry. Baseline MVR values of the studied group were compared to healthy control subjects, HLP patients with coronary artery disease (CAD) and diabetic patients with and without diabetic retinopathy. MVR was normal in HLP subjects without CAD. On the contrary, MVR was impaired in HLP patients with CAD. There was no effect of atorvastatin on MVR, despite the profound reduction of serum lipids. MVR values did not correlate with cholesterol levels. In diabetic subjects, the MVR was substantially impaired only in patients with retinopathy. In the subjects without retinopathy, MVR was either normal (type I diabetes) or moderately impaired (type II diabetes). MVR was thus normal in HLP patients without manifest vascular disease and was not influenced by lipid lowering therapy. Impairment in the MVR was only evident in subjects with HLP and severe CAD. These results suggest that microcirculation is not involved in the early vascular dysfunction induced by HLP and that MVR rather reflects changes which appear later in the course of the atherosclerotic disease., T. Štulc, Z. Kasalová, M. Prázný, M. Vrablík, J. Škrha, R. Češka., and Obsahuje bibliografii
We have used force-free extrapolations of photospheric magnetic field observations from Marshall Space Fllght Center to compute the total intensity and circular polarisation of sunspot associated emission from active region 2502 in the period June 13 to 15, 1980. The computed maps were compared to high resolution observations of tne same active region obtained witn tne Westerbork Synthesis Radio Telescope, Tne most interesting aspect of tne active region was tne developement of a new spot between the proceeding and the following spots on June 14, wnich subsequently merged witn the preceeding spot. The new spot
was associated witn enhanced microwave emission with a peak brigtness temperature in excess of 4 10^6 K. Our model computations are In satisfactory agreement witn tne sunspot observations for June 13, nowever tbey falled to reproduce tne
enhanced emission associated witn tne new spot on June 14 and 15. We snow tnat unrealistic values of tne conductive flux are required for the interpretation of tne emission of the new sunspot in terms of thermal processes. We suggest tnat tnis source Is due to gyrosynchrotron radiation from mildly relativistic electrons accelerated by reslstive instabiltles in tne evolvlng magnetic field.