Contribution to the ecology ofMarsilea quadrifolia L.

Data are presented on the aboveground and underground biomass of the speciesMarsilea quadrifolia and on the water regime and soil conditions in a habitat of this species in Central Europe (Czechoslovakia).     

Nitrate reductase activity in the course of cucumber leaf ontogenesis

Nitrate reductase activity in the leaves of young plants of cucumber.Cucumis sativus L. cv. Bílská, as determined bothin vitro andin vivo and expressed in terms of fresh weight, gradually changes in dependence on the ontogenetic development of the plants, reaching its maximum before full expansion of the leaves.     

The fine structure of membranous inclusions in the paneth cells of rabbit

Summary Paneth cells of rabbit small intestine almost constantly contain inclusions of variable size which consist of two components. The first consists of cylindrical bodies formed by concentric or spiral dense lamellae. The second is formed by tubules with triple-layered walls which may be arranged in a hexagonal pattern. The density of arrangement of both components is variable. The structure of inclusions is discussed in relation to their composition and derivation and lipid or lipoprotein composition is assumed.     

New players in the field: Ecology and biocontrol potential of three species of mollusc-parasitic nematodes of the genus Phasmarhabditis

BioControl - Nematodes of the genus Phasmarhabditis are facultative parasites of molluscs with a world-wide distribution but, so far, only one species P. hermaphrodita has been thoroughly studied...     

Effect of Different Saccharides on Viability of Isolated Microspores and Androgenic Induction in Zea Mays

Sucrose, glucose, fructose, and melibiose in different concentrations and combinations in the induction media influenced the viability of the isolated maize microspores and the formation of multinuclear structures. The induction of multinuclear structures on media containing combination of sucrose, fructose and glucose was lower than on media only with sucrose. In media containing melibiose alone or in combination with sucrose, no induction of multinuclear structures was found, however, microspore viability was improved.     

Prevalence ofCryptococcus neoformans in clinical specimens

Cryptococcus neoformans isolated from various clinical materials in 14 cases, was identified by (1) cultivation on Sabouraud glucose agar and CHROMagar Candida, (2) microscopic examination of Indian-ink-stained preparations and (3) determination of biochemical properties (assimilation and fermentation of saccharides, assimilation of KNO3, production of urease and phenol monooxygenase). C. neoformans was determined in five specimens from paediatric patients in the intensive care unit and in nine specimens from adult patients, most frequently from liquor at meningitis (n = 3).     

Discrimination between four Simocephalus species from Slovakia using a PCR-RFLP technique

Planktonic crustaceans are traditionally identified based on morphological and morphometric characters. However, such characters may be hardly distinguishable and often overlap between species. A probability of misidentification is thus relatively high. Molecular techniques may increase the accuracy of identification if appropriate markers are used. Aim of our work was to develop a simple molecular procedure enabling discrimination between four species of Simocephalus occurring in Europe. PCR-RFLP technique proved to be suitable for such discrimination. Within the 709 bp fragment of mitochondrial cytochrome c oxidase subunit 1 gene we found unique combinations of restriction sites of the BbsI and SacI enzymes for Simocephalus vetulus, S. exspinosus, S. serrulatus and S. congener. PCR products of samples from several locations in Slovakia were digested with the two enzymes and electrophoresed on an agarose gel. The restriction patterns were clearly visible and easily distinguishable. This method is applicable for identifying the four species in any life-stage. Considering its simplicity and cost-effectiveness it can be widely used as a diagnostic tool for discriminating between Simocephalus species with overlapping morphologic characters.     

Littoral benthic macroinvertebrates of mountain lakes in the Tatra Mountains (Slovakia,Poland)

Littoral benthic macroinvertebrates of 45 mountain lakes in the Tatra Mountains were sampled using a semi-quantitative method in September 2000. A total of 32,852 specimens were identified to 93 taxa belonging to 14 higher taxonomic groups. Multivariate statistics (CCA, RDA) and nine biotic metrics (AQEM/STAR) were used to explain relationships between macroinvertebrate assemblages and environmental variables. Up to 57% of the ecological position of littoral macroinvertebrate assemblages were explained by variance of environmental variables divided into chemical, trophic, physical, catchment and location. Five types of Tatra lakes were recognized using CCA: A — strongly acidified lakes (small catchment, low pH, high concentration of TP, DOC, highest amount of POM in littoral); B — alpine acidified lakes (low amount of POM, low values of biotic metrics); C — alpine non-acidified lakes (high value of diversity index, predominance of Diptera); D — subalpine acidified lakes (high values of biotic metrics: number of families, proportion of crenal and rhithral taxa/total taxa); E — subalpine non-acidified lakes (high values of biotic metrics: number of families, number of genera, BMWP score, number of taxa and abundance of EPT taxa). RDA was used to design five levels of macroinvertebrate taxa acidification tolerance. The Tatra Acidification Index (TAI) was established to assess the acidification status of the lakes in the Tatra Mts.     

Determinants of premature atherosclerosis in children with end-stage renal disease

Cardiovascular disease is a major cause of morbidity and mortality in young adults with end-stage renal disease (ESRD), but its basis is still not well understood. We therefore evaluated the determinants of atherosclerosis in children with ESRD. A total of 37 children with ESRD (with 31 who had undergone transplantation) were examined and compared to a control group comprising 22 healthy children. The common carotid intima-media thickness (CIMT) was measured by ultrasound as a marker of preclinical atherosclerosis. The association of CIMT with anthropometrical data, blood pressure, plasma lipid levels, and other biochemical parameters potentially related to cardiovascular disease was evaluated. Children with ESRD had significantly higher CIMT, blood pressure, and levels of lipoprotein (a), urea, creatinine, ferritin, homocysteine, and serum uric acid as well as significantly lower values of apolipoprotein A. The atherogenic index of plasma (log(triglycerides/HDL cholesterol)) was also higher in patients with ESRD; however, this difference reached only borderline significance. In addition, a negative correlation was found between CIMT and serum albumin and bilirubin in the ESRD group, and this correlation was independent of age and body mass index. In the control group, a significant positive correlation was observed between CIMT and ferritin levels. Factors other than traditional cardiovascular properties, such as the anti-oxidative capacity of circulating blood, may be of importance during the early stages of atherosclerosis in children with end-stage renal disease.