The remarkable progress in laser technology leads also to a development of techniques of time-resolved optical spectroscopy. The ultrafast laser spectroscopy in the visible spectral region can be now used for investigation of rapid processes with the time resolution of about 10 fs. This paper reviews the experimental background and typical techniques of ultrafast laser spectroscopy. The potentional of ultrafast spectrocopy is illustrated with the results obtained by authors in the field of ultrafast relaxation processes in semiconductors and semiconductor nanostructures., Petr Malý, Petr Němec, František Trojánek., and Obsahuje bibliografii
Ultraslabá emise fotonů se vyskytuje prakticky u všech metabolicky aktivních biologických systémů. Jejím zdrojem jsou elektronově excitované stavy molekul vznikající v průběhu oxidativních reakcí biomolekul. Ultraslabá emise fotonů detekovatelná citlivými a nízkošumovými fotonásobiči a CCD kamerami může najít uplatnění v neinvazivních diagnostických metodách v zemědělství a biomedicíně., Ultra-weak photon emission is present in virtually all metabolically active biological systems. Its source is electronically excited states of molecules produced during the oxidation reactions of biomolecules. Ultra-weak photon emission detected with sensititive and low noise photomultipliers and CCD cameras can be exploited in non-invasive diagnostics in biomedicine and agriculture., Michal Cifra, Pavel Pospíšil., and Obsahuje seznam literatury
Cíl: Zhodnotit senzitivitu, negativní prediktivní hodnotu a falešnou negativitu zobrazovacími metodami navigovaných core-cut biopsií provedených na našem pracovišti v roce 2013. Metodika: Studie zahrnuje 143 pacientů, kterým bylo provedeno celkem 148 core-cut biopsií pod ultrazvukovou (n = 139) nebo stereotaktickou (n = 9) navigací. Výsledky core-cut biopsií byly projednány formou radiologicko-patologických korelací na multidisciplinárních mammárních komisích. Ze získaných dat nálezů core-cut biopsií (s výjimkou skupiny histologicky nejasných nálezů) vztažených k pooperačním histo-logickým nálezům, potvrzenému metastatickému rozsevu nebo k dlouhodobému sledování benigních lézí byla hodnocena senzitivita, negativní prediktivní hodnota a falešná negativita core-cut biopsií. Výsledky: Senzitivita core-cut biopsie byla v naší studii 88,23 %, negativní prediktivní hodnota 84,12 %, falešná negativita 11,76 %. Závěr: Zobrazovacími metodami navigované core-cut biopsie prsu jsou bezpečnou a vysoce senzitivní metodou pro stanovení biologické povahy ložiskových lézí vyžadujících došetření., Aim: Aim of this study was to determinate sensitivity, negative predictive value and false negative rate of image-guided breast core biopsies performed in our clinic in 2013. Methods: 148 core biopsies in 143 patients were included in this study, 139 ultrasound guided and 9 stereotactically guided. Histology results of all core biopsies were reviewed at multidisciplinary meetings, careful radiologic-pathologic correlations were done. Data obtained from core biopsies (with the exception of histological uncertain findings) relative to postoperative histology, confirmed metastatic spread or long-term monitoring of benign lesions were used to calculate sensitivity, negative predictive value and false negative rate of core biopsies. Results: Sensitivity of image-guided breast core biopsy in our study reached 88.23%, negative predictive value 84.12%, false negative rate 11.76%. Conclusion: Image-guided breast core biopsy is safe and highly reliable method to determinate nature of breast lesions requiring further investigation., Hana Petrášová, Radka Šlaisová, Eva Jandáková, Světlana Dujsíková, Karel Dvořák, and Literatura
Cíl studie: Cílem této studie bylo morfologické zhodnocení vlivu DNCB na Langerhansovy buňky v epidermis v různých časových obdobích a najít vhodný test in vivo, který by charakterizoval imunoreaktivitu LCs a tím i celé kůže. Materiál a metody: Dvaceti dobrovolníkům byly aplikovány 0,2 ml DNCB (2,4-dinitrochlorobenzen) v acetonu na kůži levého předloktí. Kožní biopsie byly odebírány kožními průbojníky o průměru 3 mm do hloubky 2 mm v intervalech 1, 3, 10, 30 minut a 72 hodin po aplikaci. Výsledky: Sledovali jsme nejen morfologické změny těl Langerhansových buněk (LCs), ale také jejich dendritů. Zjistili jsme, že dendrity těchto buněk procházejí obdobnými morfologickými změnami jako těla LCs a že jejich ultrastrukturální složení je rovněž obrazem aktivace buněk. Naše nálezy potvrzují vznik Birbeckových granul (Bgs) jako ligand receptor zprostředkovanou endocytózu, což bylo nejvíce patrné u skupiny II, kde aktivace LCs probíhala rychleji, bouřlivěji a Bgs byla zachycena ve spojení s plazmatickou membránou v dendritech i v těle buněk. Dále jsme prokázali Birbeckovým granulím podobné struktury, zachycené v dendritech LCs skupiny II. Jsou projevem zvýšené reaktivity těchto buněk a nikoli jiným typem LCs. Současně s objevením Bgs v cytoplazmě Langerhansových buněk vznikají v cytoplazmě MIIC kompartmenty, jejichž množství převládá v období, kdy Langerhansovy buňky opouštějí epidermis. Závěr: Zjistili jsme, že za 30 minut po aplikaci 0,1% DNCB je možné posuzovat stupeň reaktivity kůže, protože 30 minut po aplikaci je aktivace LCs již plně rozvinuta. Domníváme se, že použitá koncentrace je dostatečná pro test vyvolávající aktivaci LCs a že přitom nemůže nepříznivě ovlivnit pacienta. Použití bioptických jehel malého průměru je šetrné, neboť jejich hloubka zasahuje jen epidermis a svrchní části koria, a není třeba užívat místní znecitlivění., Objective: The goals of this study were to assess morphologically the DNCB effect on Langerhans cells in the epidermis at different time intervals and to devise an in vivo test for characterization of immunoreactivity of Langerhans cells and thus of the whole skin. Methods: Reactivity of Langerhans cells (LCs) at different time intervals after the application of 0.1 % 2,4- -dinitrochlorobenzene (DNCB) on the skin of 20 volunteers was studied. Skin biopsy specimens were investigated 1, 3, 10, 30 minutes and 72 hours after DNCB application. Results: The dendrites underwent similar morphological changes as the bodies of Langerhans cells and the ultrastructural composition of the former also reflected cell activation. Other investigators did not previously pay attention to the dendrites. Our findings confirm formation of Birbeck granules (Bgs) resulting from ligand-receptor mediated endocytosis, most evident in group II where LCs showed more rapid and more vigorous activation and Bgs connected to the plasma membrane were detected in both dendrites and cell bodies. Furthermore, Birbeck granule-like structures were found in group II LCs dendrites. They reflect enhanced reactivity of these cells that do not represent a different type of LCs. A majority of the intracellular MHC class II molecules were found in vesicular structures, the so-called MHC-II compartment (MIIC). Simultaneously with Bgs, MIIC compartments develop in the cytoplasm and are most abundant at the moment when LCs leave the epidermis. Conclusions: We found that within 30 minutes after DNCB application, skin reactivity can be assessed, since at that interval the activation of Langerhans cells is fully completed. We suppose that the DNCB concentration used is sufficient for testing activation of Langerhans cells and at the same time no harm to the patient is to be expected. The use of biopsy needles of a small diameter is safe since the puncture affects only the epidermis and the upper layer of the corium and thus the use of local anaesthesia can be avoided., Jana Schramlová, L. Mardešičová, Pavel Barták, and Lit. 26
Genetic predisposition and social stress may represent important risk factors in etiology of hypertension associated with endothelial dysfunction. Perturbations of endothelial structural integrity are also critical for the pathogenesis of vascular diseases. We examined effect of chronic social stress on structure of aortic endothelium in bord erline hypertensive (BHR) and normotensive Wistar rats. Male BHR – offspring of Wistar mothers and SHR fathers and age-matched W were exposed to 6-week crowding stress (5 rats/cage, 200 cm2/rat). Aortic tissue was processed for electron microscopy and NO synthase activity measurement. Crowding stress significantly increased blood pressure in BHR compared to basal values (140±3 mm Hg vs. 130±3 mm Hg, p<0.05) and reduced enzyme activity by 37 % (p<0.01) in the aorta of BHR. Local slight structural alterations of endothelium were found in non-stressed BHR (p<0.001) when compared with Wistar rats. Chronic stress caused marked (p<0.005) subcellular injury of endothelial cells in aorta of BHR characterized by mitochondrial damage, presence of vacuoles, increased number of lysosomes, Weibel-Palade bodies, changes of intercellular connections and local disruption of endothelium, while only slight changes were seen in Wistar rats. Results suggest increased sensitivity of aortic endothelium of BHR to chronic crowding that may contribute to acceleration of arterial dysfunction., Ľ. Okruhlicová, K. Dlugošová, M. Mitašíková, I. Bernátová., and Obsahuje bibliografii a bibliografické odkazy
This paper describes the fine structure of oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) found in the abductor muscles of seawater clams, Meretrix meretrix (Linnaeus, 1758) (Veneridae), collected near the city of Dammam (6°17'0''N, 50°12'0''E) in the Arabian Gulf off the coast of Saudi Arabia. Oocysts of an ellipsoidal shape were found among myofibrils of the abductor muscles of infected clams. Each oocyst is composed of an oocyst wall surrounding a single uninucleate vermiform sporozoite located in the lumen of the oocyst wall. The thin oocyst wall (0.70-0.85 µm thick) is composed of homogenous electron-lucent material formed by three layers of equal-thickness. The oocyst wall contains a plano-convex opercular-like structure about 2.5 µm in diameter and 0.75-0.90 µm thick, composed of a homogenous material with moderate electron density. The oocyst is of an ellipsoidal shape and is 15.6 ± 0.6 µm long and 11.1 ± 0.7 µm wide. Externally, the oocyst wall is surrounded by a complex dense network of numerous anastomosed microfibrils, which are attached to the oocyst wall, forming 2-3 layers and extending towards the periphery, at some points penetrating amongst the host cells. The myofibrils in some cases show evident aspects of lysis as a consequence of the appearance of lysosome-like vesicles. Lacking knowledge of a complete life cycle and/or molecular data precluded the conclusive identification of this species.
The first ultrastructural description of Ceratomyxa tenuispora Kabata, 1960 (Myxozoa, Bivalvulida) from Madeira Island (Portugal), a parasite found in the gall bladder of the commercially important black-scabbard fish, Aphanopus carbo Lowe is presented. This parasite possesses spherical to ellipsoidal disporous trophozoites. Spores have a central crescent-shaped body averaging 11.0 µm in length, 28.5 µm in thickness and 12.1 µm in width. The valves have two long opposite lateral processes (ribbon-like structures or tails), each averaging 173 µm in length. The total thickness of the spore averages 375 µm. The spore has two sub-spherical polar capsules (∼5.2 × 4.1 µm), each with a polar filament with 7 to 8 coils. Some ultrastructural aspects of the sporogonic stages are described. The trophozoites develop without contact with epithelial cells. The cytoplasmic membrane has numerous evenly distributed external slender projections about 0.3 to 0.7 µm long. The sporogenesis produces two spores without pansporoblast formation. In the matrix of the capsular primordium, microtubules with an unusual organisation were observed. A binucleate sporoplasm that contains several sporoplasmosomes and dense bodies fills the spore cavity and extends to the tails without penetrating them.