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1.
Geographic patterns and time trends for breast cancer suggest there are preventable causes that may include environmental factors. This article describes the development of new methods used in the Cape Cod Breast Cancer and Environment Study to investigate whether synthetic chemicals in the environment contribute to breast cancer risk.  相似文献   
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An RNA-binding motif (RBM) gene family has been identified on the human Y chromosome that maps to the same deletion interval as the 'azoospermia factor' (AZF). We have identified the homologous gene family (Rbm) on the mouse Y with a view to investigating the proposal that this gene family plays a role in spermatogenesis. At least 25 and probably >50 copies of Rbm are present on the mouse Y chromosome short arm located between Sry and the centromere. As in the human, a role in spermatogenesis is indicated by a germ cell-specific pattern of expression in the testis, but there are distinct differences in the pattern of expression between the two species. Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are female due to a position effect resulting in non-expression of Sry ; sex-reversing such mice with an Sry transgene produces males with a high incidence of abnormal sperm, making this the third deletion interval on the mouse Y that affects some aspect of spermatogenesis. Most of the copies of Rbm map to this deletion interval, and the Yd1males have markedly reduced Rbm expression, suggesting that RBM deficiency may be responsible for, or contribute to, the abnormal sperm development. In man, deletion of the functional copies of RBM is associated with meiotic arrest rather than sperm anomalies; however, the different effects of deletion are consistent with the differences in expression between the two species.   相似文献   
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A 9.7 kb segment encompassing exons 7-10 of the adrenoleukodystrophy (ALD) locus of the X chromosome has duplicated to specific locations near the pericentromeric regions of human chromosomes 2p11,10p11, 16p11 and 22q11. Comparative sequence analysis reveals 92-96% nucleotide identity, indicating that the autosomal ALD paralogs arose relatively recently during the course of higher primate evolution (5-10 million years ago). Analysis of sequences flanking the duplication region identifies the presence of an unusual GCTTTTTGC repeat which may be a sequence-specific integration site for the process of pericentromeric- directed transposition. The breakpoint sequence and phylogenetic analysis predict a two-step transposition model, in which a duplication from Xq28 to pericentromeric 2p11 occurred once, followed by a rapid distribution of a larger duplicon cassette among the pericentromeric regions. In addition to facilitating more effective mutation detection among ALD patients, these findings provide further insight into the molecular basis underlying a pericentromeric-directed mechanism for non- homologous interchromosomal exchange.   相似文献   
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癌基因c-erbB-2在膀胱移行细胞癌中的扩增   总被引:2,自引:1,他引:1  
赵致广  张莉莉 《医学争鸣》2000,21(4):482-482
0 引言 为探讨癌基因 c- erb B- 2的扩增与膀胱移行细胞癌(TCC)的关系 ,我们以斑点杂交的方法对 40例膀胱 TCC标本中 c- erb B- 2的扩增情况进行了检测 ,以期明确 c- erb B- 2扩增与膀胱 TCC病理分级及患者预后的关系 .1 材料和方法  40例膀胱 TCC患者术后石蜡包埋标本 ,随访 5~ 10 a. 11例正常膀胱粘膜石蜡标本作为对照 . c- erb B-c DNA p CER2 0 4质粒由东京大学提供 ,Bothringer缺口平移 DNA标记试剂盒及 32 P标记 d CTP购于北京福瑞公司 .所有石蜡标本经脱蜡及蛋白酶消化 ,以酚 /氯仿抽提 DNA,乙醇沉淀 .每份样品取…  相似文献   
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