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51.
Knillová J Kolár Z 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2003,147(1):3-10
The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of Bcl-2 and members of the Bcl-2 family, and tumour suppressor gene p53. 相似文献
52.
Fiurásková M Kucerová R Kolár Z 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2003,147(1):37-41
Human hair morphogenesis is a dynamic process caused by the remodelling of the skin. Hair growth is cyclic in mammals consisting of three distinct stages: an active stage (anagen), a regressive stage (catagen), and a resting stage (telogen). One disorder in this process is gradual balding of the scalp called androgenetic alopecia. Little is known about the cell biological or molecular mechanisms involved and thus very little treatment is currently available. In this review we focus on the most significant parameters affecting hair growth which participate in baldness. 相似文献
53.
We studied population sizes and mobility of Erebia epiphron and Erebia sudetica, two high mountain butterflies forming endemic subspecies in the Hrubý Jeseník Mountains, Czech Republic. E. epiphron formed two continuous populations containing 100,000 and 4,500 individuals on alpine grasslands. The butterflies moved freely within their habitats, but movements between the two populations were highly unlikely. E. sudetica formed a system of colonies at timberline sites on valley headwalls and in forest clearings. Two such colonies studied in detail contained 4,500 and 450 adults and were interconnected by limited dispersal. The negative exponential function and the sigmoid function (this assumes flat decrease of movements over short distances) were superior to the inverse power function in fitting mobility data for both species. For E. sudetica, the functions describing movements within a habitat differed significantly from total movements, suggesting different behaviours of dispersing individuals. The habitats of E. epiphron are uniform and highly isolated, favouring free within-habitat mobility but prohibiting leaving their boundaries. The habitats of E. sudetica are diverse and disturbance-dependent; leaving such habitats is less risky, and a source-sink model may explain the persistence of the species in the mountains. 相似文献
54.
A comparative study of two modifications of enzymic reduction of ethyl N-{2-{4-[(2-oxo-cyclohexyl)methyl]phe- noxy}ethyl} carbamate (1), an insect juvenile hormone bioanalog, was performed using Saccharomyces cerevisiae in two bioreactors of different size, 250-ml shake-flask and 1-l fermenter. The two major products of this reduction were obtained in 45–49% (w/w) yields but with > 99% enantiomeric purity. Their absolute configurations were assigned as ethyl (1S,2S)-N-{2-{4-[(2-hydroxycyclohexyl)methyl]phenoxy}ethyl}carbamate (2a) and ethyl (1R,2S)-N-{2-{4-[(2-hydroxycyclohexyl)methyl]phenoxy}ethyl}carbamate (3a). 相似文献
55.
56.
Halpern MD Holubec H Dominguez JA Meza YG Williams CS Ruth MC McCuskey RS Dvorak B 《American journal of physiology. Gastrointestinal and liver physiology》2003,284(4):G695-G702
Necrotizing enterocolitis (NEC) is a common and devastating gastrointestinal disease of premature infants. Along with pathological effects in the ileum, severe NEC is often accompanied by multisystem organ failure, including liver failure. The aim of this study was to determine the changes in hepatic cytokines and inflammatory mediators in experimental NEC. The well-established neonatal rat model of NEC was used in this study, and changes in liver morphology, numbers of Kupffer cells (KC), gene expression, and histological localization of IL-18, TNF-alpha, and inducible nitric oxide synthase were evaluated. Intestinal luminal TNF-alpha levels were also measured. Production of hepatic IL-18 and TNF-alpha and numbers of KC were increased in rats with NEC and correlated with the progression of intestinal damage during NEC development. Furthermore, increased levels of TNF-alpha in the intestinal lumen of rats with NEC was significantly decreased when KC were inhibited with gadolinium chloride. These results suggest an important role of the liver and the gut-liver axis in NEC pathogenesis. 相似文献
57.
T1alpha/podoplanin deficiency disrupts normal lymphatic vasculature formation and causes lymphedema 总被引:25,自引:0,他引:25
Schacht V Ramirez MI Hong YK Hirakawa S Feng D Harvey N Williams M Dvorak AM Dvorak HF Oliver G Detmar M 《The EMBO journal》2003,22(14):3546-3556
Within the vascular system, the mucin-type transmembrane glycoprotein T1alpha/podoplanin is predominantly expressed by lymphatic endothelium, and recent studies have shown that it is regulated by the lymphatic-specific homeobox gene Prox1. In this study, we examined the role of T1alpha/podoplanin in vascular development and the effects of gene disruption in mice. T1alpha/podoplanin is first expressed at around E11.0 in Prox1-positive lymphatic progenitor cells, with predominant localization in the luminal plasma membrane of lymphatic endothelial cells during later development. T1alpha/podoplanin(-/-) mice die at birth due to respiratory failure and have defects in lymphatic, but not blood vessel pattern formation. These defects are associated with diminished lymphatic transport, congenital lymphedema and dilation of lymphatic vessels. T1alpha/podoplanin is also expressed in the basal epidermis of newborn wild-type mice, but gene disruption did not alter epidermal differentiation. Studies in cultured endothelial cells indicate that T1alpha/podoplanin promotes cell adhesion, migration and tube formation, whereas small interfering RNA-mediated inhibition of T1alpha/podoplanin expression decreased lymphatic endothelial cell adhesion. These data identify T1alpha/podoplanin as a novel critical player that regulates different key aspects of lymphatic vasculature formation. 相似文献
58.
Human mast cells are professional secretory cells that store synthetic products in large granules filling their cytoplasm. Unlike many secretory cells, the principal synthetic organelle, ribosome-rich endoplasmic reticulum, is a minor component of their cytoplasm. Sightings of nonmembrane-bound ribosomes in and near their secretory granules stimulated detailed ultrastructural studies of various RNA species to implicate secretory-storage granules in RNA biology. In the work reported here, postembedding immunogold ultrastructural cytochemistry indicates that human mast cells contain uridine, an integral ingredient of RNA, and ribonucleoproteins, known to associate with small nuclear RNAs important for splicing RNA precursors, several ribonucleoproteins with possible functions in other aspects of RNA biology and ribonucleoproteins known to associate with ribosomes. These findings should catalyse future work toward establishing the full functional repertoire of secretory-storage granules. 相似文献
59.
60.
Jolanta Kolodziejek Bernhard Seidel Christof Jungbauer Katharina Dimmel Michael Kolodziejek Ivo Rudolf Zdenek Hubálek Franz Allerberger Norbert Nowotny 《PloS one》2015,10(5)
The detection of West Nile virus (WNV) nucleic acid in a blood donation from Vienna, Austria, as well as in Culex pipiens pupae and egg rafts, sampled close to the donor’s residence, is reported. Complete genomic sequences of the human- and mosquito-derived viruses were established, genetically compared and phylogenetically analyzed. The viruses were not identical, but closely related to each other and to recent Czech and Italian isolates, indicating co-circulation of related WNV strains within a confined geographic area. The detection of WNV in a blood donation originating from an area with low WNV prevalence in humans (only three serologically diagnosed cases between 2008 and 2014) is surprising and emphasizes the importance of WNV nucleic acid testing of blood donations even in such areas, along with active mosquito surveillance programs. 相似文献