The development of Myxobolus dispar Thélohan, 1895, a myxosporean parasite of the gills of common carp (Cyprinus carpio L.) was studied in experimentally infected oligochaetes Tubifex tubifex Muller. After infection of uninfected tubificids with mature spores of M. dispar, development of actinosporean stages was first observed light microscopically 21 days after initial exposure. In histological sections, early pansporocysts were located in the gut epithelium of experimental oligochaetes, while advanced stages occupied mostly the outer layers of the gut and the coelozoic space. Mature pansporocysts, each containing 8 raabeia spores, appeared 199 days after initial exposure. Following damage of the intestinal wall and rupture of the pansporocysts, free actinosporean stages were found in the gut lumen of the oligochaetes. Actinospores of hi. dispar emerged from the worms after 217 days of intra-oligochaete development. They were floating in the water and showed a unique raabeia form. Each raabeia spore had three pyriform polar capsules and a cylindrical-shaped sporoplasm with approximately 32 secondary cells. The spore body joined the three caudal projections without a style. Caudal projections were bifurcated at the end and the two main branches had further small bifurcations. The total length of the raabeia spore was approximately 158 pm. The prevalence of infection in 240 experimentally infected Tubifex specimens was 99.2%. No infection was found in the control oligochaetes.
In greening mustard cotyledons, both photosystems (PS) 1 and 2 were significantly promoted by addition of gibberelic acid (GA) at low concentrations, i.e. upto 10 μΜ, while at higher concentrations no significant changes were recorded. PS2 activity in kinetin (KN) treated seedlings was promoted at concentrations upto 5 μΜ KN, while it showed a slight inhibition at higher concentrations. No significant change in PS1 activity was observed when compared to controls. Other particular photosynthetic electron transport reactions were also increased by GA and KN. KN03 showed concentration-dependent effects on photosynthetic electron transport reactions.
The development of the nematode Procamallanus saccobranchi Karve, 1952, a parasite in the stomach of the fish Heteropneustes fossilis (Bloch), was studied in Mesocyclops crassus (Fischer) and Mesocyclops leuckarti (Claus). After being ingested by the copepods the nematode first-stage larvae penetrated into the haemocoel of the intermediate host; there they moulted twice (on days 3 and 5 p.i. at 28-30°C) attaining the third, infective stage. The definitive host H. fossilis acquired infection by feeding on copepods harbouring infcclivc-stage larvae; in the stomach of this definitive host, the larvae were observed to undergo two more moults. The third moult occurred on day 13 p.i. and the fourth moult on day 38 p.i. and day 66 p.i. in “male” and “female” larvae, respectively. The larval stages, including the moulting forms are described and illustrated.
b1_We newly elaborated and adapte d several radiometric enzyme assays for the determination of activities of the key enzymes engaged in the biosynthesis (thyroid peroxidase, TPO) and metabolic transformations (conjugating enzymes and iodothyronine deiodinases, IDs) of thyroid hormones (THs) in the thyroid gland and in peripheral tissues, especially in white adipose tissue (WAT). We also elaborated novel, reliable radiometric methods for extremel y sensitive determination of enzyme activities of IDs of types 1, 2 and 3 in microsomal fractions of different rat and hum an tissues, as well as in homogenates of cultured mammalia n cells. The use of optimized TLC separation of radioactive products from the unconsumed substrates and film-less autoradiography of radiochromatograms, taking advantage of storage phosphor screens, enabled us to determine IDs enzyme activities as low as 10-18 katals. In studies of the interaction of fluoxetine (Fluox) with the metabolism of THs, we applied adapted radiometric enzyme assays for iodothyronine sulfotransferases (ST) and uridine 5’-diphosphoglucuronyltransferase (UDP-GT). Fluox is the most frequently used representative of a new group of non-tricyclic antidepressant drugs - selective serotonin re-uptake inhibitors. We used the elaborated assays fo r quantification the effects of Fluox and for the assessment of th e degree of potential induction of rat liver ST and/or UDP-GT enzyme activities by Fluox alone or in combination with T3 . Furthermore, we studied possible changes in IDs activities in murine adipose tissue under the conditions that promoted either tissue hypertrophy (obesogenic treatment) or involution (caloric restriction), and in response to leptin, using our newly developed radiometric enzyme assays for IDs., b2_Our results suggest that deiodinase D1 has a functional role in WAT, with D1 possibly being involved in the control of adipose tissue metabolism and/or accumulation of the tissue. Significant positive correlation between specific enzyme activity of D1 in WAT and plasma leptin levels was found. The newly developed and adapted radiometric enzyme assays proved to be very useful tools for studies of factors modulating THs metabolism, not only in model animals but also in clinical studies of human obesity., S. Pavelka., and Obsahuje bibliografii a bibliografické odkazy
This study presents data about the effect of parent material on the intensity of processes that lead to the formation of a cambic subsurface horizon. The study was performed in the Voděradské bučiny National Nature Reserve with granite bedrock and in Humpolec with paragneiss bedrock. Representative soil profiles in the southeastern part of Bohemia were characterised on a macroscale level based on macromorphological description, particle size distribution, chemical, physical and soil organic matter properties. On the basis of the values of organic carbon and bulk density, the stock of soil organic matter was calculated in the upper 25 cm of soils. A more detailed characteristic of soil cover employed micromorphological and X-ray diffraction analyses. The results revealed differences in the formation of the cambic horizon on different types of parent material. The main soil forming process responsible for the cambic horizon is more intensive at localities with paragneiss bedrock., Anna Žigová, Martin Šťastný and Radka Kodešová., and Obsahuje bibliografii
Fifty-day-old fry of tilapia hybrids (Oreochromis aureus x niloticus) were placed in aquaria containing sediment with oocysts of Eimeria (sensu lato) vanasi Landsberg et Paperna. In the first 29 h after exposure sporulated oocysts in the stomach and free sporozoites in the gut could be found in examined fish. By 7 to 56 h after exposure, sporozoites, with their characteristic crystalloid body, were detected in intraepithélial lymphocyte-like and other leucocyte-like cells, but never in the epithelial cells. Infected cells were confined to the epithelial layer and did not enter the lamina propria. Within this time, some of the sporo-zoitcs divided by endodyogeny, once or twice in succession, to form daughter sporozoites. The parent’s sporozoite crystalline body was divided between the offspring of the primary and secondary divisions.
AIM: The purpose of this study was to develop a revised version of the Brief Bedside Dysphagia Screening Test for determining penetration/aspiration risk in patients prone to dysphagia. The priority was to achieve high sensitivity and negative predictive value. METHODS: The study screeners conducted bedside assessment of the swallowing function in 157 patients with a neurological (mainly stroke) or an ear, nose, and throat diagnosis (mainly head and neck cancer). The results were compared with a gold standard, flexible endoscopic examination of swallowing. RESULTS: For the neurological subgroup (N = 106), eight statistically significant bedside assessment items were combined into the Brief Bedside Dysphagia Screening Test-Revised (BBDST-R). Cut-off score 1 produced the highest sensitivity (95.5%; 95% confidence interval CI [CI]: 84.9-98.7%) and negative predictive value (88.9%; 95% CI 67.2-96.9%). CONCLUSION: The BBDST-R is suitable for dysphagia screening in departments caring for patients with neurological conditions. and P. Mandysová, E. Ehler, J. Škvrňáková, M. Černý, I. Bártová, A. Pellant
Inhibitory neurotransmission plays a substantial role in encoding of auditory cues relevant for so und localization in vertebrates. While the anatomical organization of the respective afferent auditory brainstem circuits shows remarkable similarities between mammals and birds, the properties of inhibitory neurotransmission in these neural circuits are strikingly different. In mammals, inhibition is predom inantly glyciner gic and endowed with fast kinetics. In birds, inhibition is mediated by γ - Aminobutiric acid (GABA) and too slow to convey temporal information. A further prominent difference lies in the mechanism of inhibition in the respective systems. In auditory brainstem neurons of mammals, [Cl-] i undergoes a developmental shift causing the actions of GABA and glycine to gradually change from depolarization to the ‘classic’ hyperpolarizing-inhibition before hearing onset. Contrary to this, in the mature avian auditory brainstem Cl - homeostasis mechanisms accurately adjust the Cl - gradient to enable depolarizing, but still very efficient, shunting inhibition. The present review considers the mechanisms underlying development of the Cl - homeostasis in the auditory system of mammals and birds and discusses some open issues that require closer attention in future studies., I. Milenković, R. Rübsamen., and Obsahuje bibliografii a bibliografické odkazy
The aim of the study was to assess the impact of preweaning overnutrition upon the ontogeny of intestinal microbiota, alkaline phosphatase activity (AP) and pa rameters of growth and obesity in male Sprague-Dawley rats. We tested whether intestinal characteristics acquired in suckling pups could programme the development of enhanced fat deposition during normalized nutrition beyond weaning. Postnatal nutrition was manipulated by adjusting the number of pups in the nest to 4 (small litters - SL) and 10 (normal litters - NL). In the postweaning period both groups were fed with a standard diet. The jejunal and colonic Lactobacillus/Enterococcus (LAB) and the Bacteroides/Prevotella (BAC) were determined using the FISH technique, and the jejunal AP activity was assayed histochemically. At 15 and 20 days of age the SL pups became heavier, displayed increased adiposity accompanied by significantly higher LAB and lower numbers of BAC and with higher AP activity in comparison with rats nursed in NL nests. These differences pers isted to day 40 and withdrawal of the previous causal dietary influence did not prevent the post-weaning fat accretion. These results reveal the significance of early nutritional imprint upon the gut microbial/functional development and allow better unde rstanding of their involvement in the control of obesity., Z. Šefčíková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
F.xcept other functions, surface saccharide residues on trematode larvae are supposed either to be the targets of the intermediate (molluscan) and final host immune systems, or to represent candidates for molecular mimicry. Therefore, changes in surface saccharide patterns during the development of the avian schistosome Trichobilharzia szidati were characterized. Whole parasite larval stages and their tissue sections were examined using FITC-conjugated lectins. Marked surface differences were found among larval stages (miracidia, mother sporocysts, daughter sporocysts, cercariae, schistosomula). Staining by some lectins reflected known ultrastructural changes of the outer tegument. Reaction of lectins with cercarial embryos was almost negative. In case of other developmental stages, binding of at least one member from each carbohydrate-specificity group of lectins (Man/Glc-, GIcNAc-, Gal/GalNAc- and Fuc-specific) occurred. One exception is represented by mother and daughter sporocysts which practically failed to react with Fuc-specific lectins. Besides other lectins which recognized larval surfaces, a-L-fucose-specific lectins (LTA, UEA-I) and (GlcNAcfll —>4)„-spccific WGA bound very strong to certain stages. The comparison of mature intrasporocystic cercariae with those emerged from snails brought the indication that some snail glycosylated molecules adhere to the surface of schistosome larvae or that emerged cercariae express some new carbohydrate epitopes under changed environmental conditions. The result partially supports the theory of parasite mimicry/masking strategies and immune evasion in the host.