The aim was to study the blood-brain permeability according to the distribution in the rat brain of Evans blue (EB) and sodium fluorescein (NaFl) administered by an intracarotid injection. Eighteen animals were divided into six groups according to the state of the blood-brain barrier (BBB) at the moment when the dyes were being applied. In the first two groups, the BBB was intact, in groups 3 and 4 the barrier had been opened osmotically prior to the application of the dyes, and in groups 5 and 6 a cellular edema was induced by hyperhydration before administration of the dyes. The intracellular and extracellular distribution of the dyes was studied by fluorescence microscopy. The histological picture thus represented the morphological correlate of the way BBB permeability had been changed before the application of the dyes., P. Kozler, J. Pokorný., and Obsahuje bibliografii
Diabetes is a recognized risk factor of heart disease. The abnormalities related to a decreased heart performance probably arise at cellular and molecular levels already in the asymptomatic phase of diabetes. However, the early alterations initiating a sequence of events that culminates in the clinical signs have not been fully elucidated yet. This review deals with some biophysical methods applied to investigation of left ventricular myocytes in rats with streptozotocin diabetes, as well as our most important findings concerning diabetes-induced cell changes which cannot be captured by other techniques. The observed decrease in sarcolemmal membrane fluidity is causatively associated with increased glycation and glycoxidation. On the other hand, an increase in the mitochondrial membrane fluidity may be attributed to augmented energy transduction through the membranes. We reported for the first time concurrent measurements of membrane potential and dynamics, and respiratory chain activities in rat heart mitochondria, as well as calcium transients in the myocytes from diabetic hearts together with the assessed quantitative relationships among these variables. We were able to detect some significant alterations that may underlie myocyte dysfunction and subsequent remodeling of the heart. We suppose that not all these changes reflect mechanisms leading to pathology; some may represent adaptive and compensatory responses to diabetes., I. Waczulíková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
French bean (Phaseolus vulgaris L.) cotyledons lost most of their reserve substances during several early days of germination and turned green. In cotyledon mesophyll cells of one-week-old seedlings, plastids were represented predominantly by amyloplasts (starch grains) and chloroamyloplasts, and the cells appeared to be metabolically highly active. Cell heterogeneity associated with distance of the cells from cotyledon vascular bundles was evident. Only mesophyll cells near to the bundles were rich in plastids. In two-weeks-old intact bean plants, the cotyledons were yellow and shrunken, and their cells were nearly "empty". The plastids in them were represented by senescent plastids (gerontoplasts) only. In the gerontoplasts as well as freely in cytosol, fluorescent lipoid inclusions were accumulated. This cotyledon development was more or less independent of irradiance. In "decapitated" bean plants, senescence of mesophyll cells and plastids was slowed down considerably, and the life span of the cotyledons was prolonged. and J. Kutík, N. Wilhelmová, J. Snopek.
Při studiu interakcí bakterií a prvoků se používají zejména metody fluorescenční mikroskopie v kombinaci se značenými bakteriemi, nebo i vysoce specifické fluorescenčně značené RNA-sondy (fluorescence in situ hydridizace), které umožňují i přesnou taxonomickou identifikaci druhů bakterií, pohlcovaných prvoky. Můžeme tak studovat nejenom rychlost, ale i selektivitu eliminace bakterií heterotrofními a mixotrofními bičíkovci a nálevníky v různých přírodních vodách., Trophic interaction between bacteria and protozoa is mainly studied by means of fluorescence microscopy exploiting various fluorescence labelling of bacteria, including highly specific RNA-probes for fluorescence in situ hybridization, which allows precise identification of bacterial species grazed by protozoa. By combining these approaches we can examine not only the total rate of protozoan bacterivory, but also the grazing selectivity of heterotrophic and mixotrophic flagellates and ciliates feeding on bacteria in a broad array of aquatic ecosystems., Karel Šimek., and autor: Redakce a Karel Šimek
Digital microscopy imaging methods developed at the Institute of Physical Engineering introduce innovative application potential. Application possibilities of imaging capabilities of developed optical microscopes are presented here. and Metody digitálního mikroskopového zobrazování dlouhodobě rozvíjené na pracovišti Ústavu fyzikálního inženýrství nabízí inovativní aplikační potenciál. Jsou prezentovány možnosti využití zobrazovacích schopností vyvinutých optických mikroskopů.