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971.
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J Peńsko K Pachocki Z Rózycki T Majle B Gorzkowski E Wilejczyk 《Canadian Metallurgical Quarterly》1998,49(2):189-198
To study the mechanisms of dorsal axis specification, the alteration in dorsal cell fate of cleavage stage blastomeres in axis-respecified Xenopus laevis embryos was investigated. Fertilized eggs were rotated 90 degrees with the sperm entry point up or down with respect to the gravitational field. At the 8-cell stage, blastomeres were injected with the lineage tracers, Texas Red- or FITC-Dextran Amines. The distribution of the labeled progeny was mapped at the tail-bud stages (stages 35-38) and compared with the fate map of an 8-cell embryo raised in a normal orientation. As in the normal embryos, each blastomere in the rotated embryos has a characteristic and predictable cell fate. After 90 degrees rotation the blastomeres in the 8-cell stage embryo roughly switched their position by 90 degrees, but the fate of the blastomeres did not simply show a 90 degrees switch appropriate for their new location. Four types of fate change were observed: (i) the normal fate of the blastomere is conserved with little change; (ii) the normal fate is completely changed and a new fate is adopted according to the blastomere's new position: (iii) the normal fate is completely changed, but the new fate is not appropriate for its new position; and (4) the blastomere partially changed its fate and the new fate is a combination of its original fate and a fate appropriate to its new location. According to the changed fates, the blastomeres that adopt dorsal fates were identified in rotated embryos. This identification of dorsal blastomeres provides basic important information for further study of dorsal signaling in Xenopus embryos. 相似文献
977.
E Marsza? K Wojaczyńska-Stanek B Szwed-Bia?ozyt E Jamroz 《Canadian Metallurgical Quarterly》1998,32(3):523-531
In the recent years the number of diagnosed cases of Lyme Disease has tended to increase. This is due to the possibility of serological examinations. Between 1992-95 at the Neurological Department of 2nd Chair of Pediatrics Silesian Medical Academy in Katowice 7 children with Lyme Disease were hospitalized. The authors analysed the clinical course, important laboratory and serological data and treatment effects. 相似文献
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979.
The incidence of bladder cancer continues to increase, with an estimated 53,000 new cases diagnosed in the United States in 1996-90% of which are transitional cell carcinomas. The male-to-female ratio is 3:1. A number of etiological factors are associated with the development of bladder cancer, but in industrialized countries, cigarette smoking is the most important. Specific chemicals have also been identified as causing bladder cancer, as have a number of occupational exposures to less well-defined specific agents. Treatment with cytostatic drugs, especially cyclophosphamide, is associated with increased risk of bladder cancer, as is treatment with radiotherapy for uterine cancer. In developing countries, especially in the Middle East and parts of Africa, infections with members of the genus Schistosoma are responsible for a high incidence of bladder cancer-75% of which are squamous cell carcinomas. Arsenic has been indicated as a bladder carcinogen in Argentina, Chile, and Taiwan. The reason for the high incidence of urinary tract cancer in individuals suffering from Balkan nephropathy has yet to be determined. A careful history of patients with bladder cancer is an important and useful process in helping to identify causal factor and, in more than one-half the cases, a known relationship is found. Bladder cancer is a potentially preventable disease, with a significant morbidity and mortality in many parts of the world. 相似文献
980.
We presented in our study methods and results of blood flow measurements with Doppler ultrasound in uterine and arcuate arteries in relation to localization of placenta in physiological pregnancy. We performed examinations in 154 pregnant women with pregnancy age of 32-42 wk. On the basis of qualitative analysis of blood flow waveforms we discovered the difference in the blood flow in utero-placental compartment in relation to placental localization and we proved that this change takes place in uterine as well an in arcuate arteries. 相似文献