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81.
1. Mechanical forces associated with blood flow play important roles in the acute control of vascular tone, the regulation of arterial structure and remodelling and the localization of atherosclerotic plaque. Uraemia is a proatherogenic process and is expected to be associated with impaired vascular reactivity.2. To study this, 12 male Wistar rats were rendered uraemic by five-sixths nephrectomy and 12 control rats were sham operated simultaneously. After 8 weeks a tail-cuff systolic blood pressure was recorded, blood samples were taken and the animals killed. Isolated femoral arteries were dissected and mounted on a pressure myograph and myogenic tone was assessed over a range of intravascular pressures from 40 to 160 mmHg. Histologically the arteries were comparatively examined for gross morphology, calcification and deposition of collagen.3.Biochemically the serum urea and creatinine were greater in the uraemic compared with the control rats (urea: 23.5+/-6 mmol/l and 6.8+/-01 mmol/l respectively, P not significant; creatinine: 130.7+/-13 mmol/l and 70.3+/-5 mmol/l respectively, P<0.01) but systolic blood pressure was the same in both groups (control, 97+/-1 mmHg; uraemic, 98+/-2 mmHg), compatible with mild uraemia.4. Myogenic tone was significantly greater in uraemic vessels (7.3+/-1.8% versus 2.3+/-0. 4% in control, P=0.01). The actual vessel lumen diameter was also smaller in pressurized uraemic vessels compared with control vessels (471+/-30 microm versus 604+/-33 microm, P<0.01) after equilibration in physiological salt solution. However, when incubated in calcium-free physiological salt solution, the passive internal diameter was similar in uraemic vessels (538+/-25 microm compared with 595+/-31 microm in control). Histologically, there were no differences between the two groups.5. We conclude that some aspects of vascular reactivity are altered in mild experimental uraemia as shown by a reduced internal lumen diameter and increased myogenic tone. Furthermore, these changes are apparent in the absence of hypertension and precede structural changes. 相似文献
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MSH6, a Saccharomyces cerevisiae protein that binds to mismatches as a heterodimer with MSH2 总被引:1,自引:0,他引:1
I Iaccarino F Palombo J Drummond NF Totty JJ Hsuan P Modrich J Jiricny 《Canadian Metallurgical Quarterly》1996,6(4):484-486
The process of post-replicative DNA-mismatch repair seems to be highly evolutionarily conserved. In Escherichia coli, DNA mismatches are recognized by the MutS protein. Homologues of the E. coli mutS and mutL mismatch-repair genes have been identified in other prokaryotes, as well as in yeast and mammals. Recombinant Saccharomyces cerevisiae MSH2 (MSH for MutS homologue) and human hMSH2 proteins have been shown to bind to mismatch-containing DNA in vitro. However, the physiological role of hMSH2 is unclear, as shown by the recent finding that the mismatch-binding factor hMutS alpha isolated from extracts of human cells is a heterodimer of hMSH2 and another member of the MSH family, GTBP. It has been reported that S. cerevisiae possesses a mismatch-binding activity, which most probably contains MSH2. We show here that, as in human cells, the S. cerevisiae binding factor is composed of MSH2 and a new functional MutS homologue, MSH6, identified by its homology to GTBP. 相似文献
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AP Ford NF Arredondo DR Blue DW Bonhaus J Jasper MS Kava J Lesnick JR Pfister IA Shieh RL Vimont TJ Williams JE McNeal TA Stamey DE Clarke 《Canadian Metallurgical Quarterly》1996,49(2):209-215
Hereditary developmental abnormalities of the upper or lower limbs in humans are easily recognizable phenotypes that can be used in the mapping and cloning of genes involved in normal human development. We studied a large Indian pedigree (UR002) with an autosomal dominant triphalangeal thumb (TPT) and polysyndactyly (PSD). The abnormalities were present only in the upper limbs, and the phenotype was fully penetrant. The expression of the phenotype was variable and ranged from unilateral TPT to bilateral TPT, preaxial du-, tri-, or quadruplication of the thumb, or syndactyly of multiple thumbs. There were 112 affected individuals in the pedigree. Previous linkage analyses on apparently similar phenotypes have identified a locus at 7q36 [Heutink et al., 1994, Nature Genet 6:287-291; Tsukurov et al., 1994]. To map the gene responsible for the TPT-PSD in family UR002, we performed linkage analysis in DNA from 47 affected and 7 normal individuals. Marker D7S550, located at 7q36, yielded a maximum LOD score of 11.31 at theta = 0.00. Additional markers in the region also showed no recombination. These data indicate that the gene responsible for the hand abnormality in pedigree UR002 maps to the same region as that in previous pedigrees with similar phenotype. Further analyses of recombinants among all the linked families by using new polymorphic markers will narrow the critical genomic region and facilitate positional cloning of the elusive gene. 相似文献
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NI Larionova IP Gladysheva IN Topchieva NF Kazanskaia 《Canadian Metallurgical Quarterly》1993,58(10):1658-1664
A classical soybean inhibitor of the Bowman-Birk type (BBI) with a copolymer of ethylene oxide and propylene oxide (PE) has been synthesized. The BBI-PE conjugate contain five covalently bound polymeric chains per one protein molecule and retains its capacity to inhibit trypsin (Ki = 10(-10) M), alpha-chymotrypsin (Ki = 7 x 10(-8) M) and human granulocyte elastase (Ki = 3 x 10(-8) M). The preservation of the antiproteinase activity in the antichymotrypsin center creates a prerequisite for the manifestation of the anticarcinogenic effect of the inhibitor. 相似文献
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In March 1992, KAP investigation and HIV blood test were carried out for 860 drug users and 82 spouses in Ruili, Luxi, Longchuan of Yunnan Province, China. The results show that there were 285 IDUs (33.1%) among 860 drug users. Among 282 blood samples of IDUs, the HIV infection rate was 49.0%, highest in Ruili (81.8%, 63/77), then Longchuan (44.6%, 77/166), lowest in Luxi County (5.1%, 2/36). Twelve new HIV+ were found from 75 persons, who had been tested as HIV- in recent two years. Sixty-two blood samples were collected among 82 spouses of IDUs with HIV+, 6 were HIV+ (9.8%), with an increase of 6.7% comparing with results of the investigation two-years ago (3.1%, 2/64). 相似文献
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