Spermatozoa of the monogenean Heterocotyle capricornensis Chisholm et Whittington, 1996 are long and filiform, comprising an elongate nucelus, probably a single elongate mitochondrion and two incorporated axonemes, one of which is shifted with respect to the other. The shift results in a region at each end of the sperm where only one axoncmc is present, accompanied by the nucleus and mitochondrion at one end and the nucleus and/or mitochondrion at the other. By taking note of the direction of dyncin arms on the axonemal doublet microtubules, each axoneme is identified and followed from beginning to end. No basal bodies remain in mature sperm but the main nuclear end is interpreted as proximal/anterior based on the final stages of spermiogenesis. A group of four or five cortical microtubules from the spermatid zone of differentiation persists in mature sperm, but is not closely associated with a region of extracellular matrix, as it is in other monocotylids. The sperm structure is compared with that of other monocotylids and the phylogenetic implications are discussed. Aberrant sperms in one individual were folded and fused along much of their length.
Spermiogenesis and the spermatozoon were studied in the digenean Mesocoelium monas Rudolphi, 1819 (from the toad Bufo sp. in Gabon). An ultrastructural study revealed that spermiogenesis follows the usual pattern found in digeneans, i.e. proximo-distal fusion of axonemes with a median cytoplasmic process followed by elongation. The spermatozoon has two fully incorporated axonemes with the 9 +“1” trepaxonematan pattem. Indirect immunofluorescence localization of tubulin and fluorescent labelling of the nucleus were used to obtain additional information on the structure of the spermatozoon. It was thus shown that one of the axonemes is slightly shorter than the other (190 versus 220 pm) and that the filiform nucleus (65 pm in length) is located at the distal extremity of the spermatozoon (220 pm in length). Various monoclonal and polyclonal antibodies, specific to alpha, beta, acetylated-alpha, or general tubulin, were used and produced similar labelling.
Sphingolipids are a diverse and ubiquitous group of lipids. They are widely distributed in parasites and a number of novel forms have been described. Sphingolipid synthesis has been investigated in the malarial parasite, cestodes, digencans and nematodes. Although there are differences in detail, the synthetic pathways involved are similar to those found in mammals.
Gluteal muscle contracture (GMC) is a chronic fibrotic disease of gluteal muscles due to multiple etiologies. The main pathologic process is characterized by proliferation of fibroblasts and excessive accumulation of collagen in the extracellular matrix of the muscle. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and has been reported to be associated with various fibrotic diseases. However, the role of S1P in GMC remains unknown. Here in this articl e, High-perform ance liquid chromatography and immunohistochemistry were applied to evaluate S1P localization and expression in clinical samples from patients with GMC, Quantitative real time PCR, Western blot, and enzyme-linked immunosorbent assa y were used to explore the link between transforming growth factor-β 1 (TGF- β 1), plasminogen activator inhibitor-1 (PAI-1) and S1P. The results showed that S1P was enhanced in contraction band (CB) tissues. Studies using the cell proliferation and transformation assay indicated that exogenous S1P stimulated CB fibroblast proliferation in a time-depen dent manner and in higher concentration also in a dose-dependent manner. Furthermore, we demonstrated that S1P not only promoted collagen type I production, but also up-regulated mRNA and protein expression of transforming growth factor-β 1 and plasminogen activator inhibitor-1. These findings suggest that S1P may regulate increased synthesis of collagen and other fibrogenic factors, and significantly contributes to the process of gluteal muscle scarring in patients with GMC., C. G. Zhao ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Rossijskaja nacional'naja biblioteka Sankt Peterburg RU O 9, Rijksuniversiteit Groningen NL 2521/1984 - s digitální kopií, Ústav pro českou literaturu AV ČR Praha CZ 908 k - fotokopie petrohradského exempláře, Knihovnaa Akademie věd ČR Praha CZ TH 15 - fotokopie petrohradského exempláře, AMSTELODAMI, Typis CHRISTOPHORI CUNRADI, Anno 1680., and BCBT38095
Akademie věd ČR představila na prosincovém Akademickém sněmu novou strategii, která se připravovala dlouhou dobu kromě jiného v diskusi s řediteli pracovišť. Každá změna samozřejmě vyvolává ohlasy v celé šíři škály - od záporných reakcí až po ty kladné. Strategii AV21 představujeme čtenářům na následujících stránkách současně s informacemi ze sněmovního zasedání, ale přesto jsem požádala předsedu AV ČR prof. Jiřího Drahoše o zodpovězení několika otázek. and Marina Hužvárová.