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排序方式: 共有1002条查询结果,搜索用时 15 毫秒
91.
A technique is described for using the internal mammary artery to bypass the left anterior descending coronary artery and another adjacent coronary artery even when the alignment of the two vessels is not favorable for a conventional sequential graft. The distal end of the mammary artery is amputated and used to construct a Y graft to the anterior descending artery and to the secondary target vessel. 相似文献
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Escherichia coli O29:H21 is a human enterotoxigenic serotype that produces heat-stable (ST-I) enterotoxin, adheres diffusely to HeLa cells, and presents colonization factor antigen IV (CFA/IV) composed of CS5CS6 surface antigens. In one strain studied the genes for diffuse adherence and CFA/IV (CS5CS6) production were found to be present in the same plasmid encoding ST-I. The virulence plasmid (Ent) presented two unrelated basic replicons homologous to repFIC and repW. Gene(s) encoding diffuse adherence did not share homology with the probe for F1845 fimbrial adhesin which is responsible for this phenotype in other E. coli strains. Ent plasmids containing genes for diffuse adherence have not been described previously. 相似文献
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BE Schenk HP Festen EJ Kuipers EC Klinkenberg-Knol SG Meuwissen 《Canadian Metallurgical Quarterly》1996,10(4):541-545
AIMS: To evaluate absorption of protein-bound and unbound cyanocobalamin before and during treatment with omeprazole, and cobalamin levels in patients on long-term treatment with omeprazole. METHODS: In eight former duodenal ulcer patients absorption of unbound and protein-bound cobalamin was determined by measuring 24-h urinary excretion of unbound 58Co-cyancobalamin or protein-bound 57Co-cyanocobalamin during a modified Schilling test. Tests were performed before and during treatment with 20 mg and 40 mg omeprazole daily for 9 days. Serum cobalamin levels were assessed in 25 patients with gastro-oesophageal reflux disease (GERD) before and during long-term maintenance therapy with omeprazole. Mean treatment duration was 56 months (range 36-81 months). RESULTS: Urinary excretion of unbound cobalamin was unchanged with both dosages of omeprazole. Excretion of 57Co-cyanocobalamin, however, decreased significantly during treatment with both 20 mg omeprazole (mean +/- S.E.M.: 1.31 +/- 0.20 vs. 0.54 +/- 0.17%; P < 0.02) and 40 mg omeprazole (1.25 +/- 0.26 vs. 0.29 +/- 0.06%; P < 0.02). Mean serum cobalamin levels (+/- S.E.M.) before and during therapy with omeprazole in GERD patients were 298 +/- 27 and 261 +/- 16 pg/mL (normal range 180-900 pg/mL), respectively (P = N.S.). CONCLUSIONS: Absorption of protein-bound, but not unbound, cyanocobalamin is decreased when measured by a modified Schilling test during treatment with omeprazole. However, no change in serum cobalamin levels was observed in patients with GERD after treatment with omeprazole for up to 7 years. 相似文献
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I Orlow A Iavarone SJ Crider-Miller F Bonilla E Latres MH Lee WL Gerald J Massagué BE Weissman C Cordón-Cardó 《Canadian Metallurgical Quarterly》1996,56(6):1219-1221
Mammalian cyclin-dependent kinase inhibitors fall into two families, the INK4 and the CIP/KIP. The CIP/KIP family comprises three structurally related members, including p21CiP1/WAF1, p27KIP1, and p57KIP2. These proteins are all capable of inhibiting the progression of the cell cycle by binding and inhibiting G(1) cyclin/cyclin-dependent kinase complexes. In humans, p57KIP2 is expressed specifically in skeletal muscle, heart, brain, kidney, and lung. Human KIP2 resides in 11p15.5, a chromosomal region that is a common site for loss of heterozygosity in certain sarcomas, Wilms' tumors, and tumors associated with the Beckwith-Wiedemann syndrome. Because of the function, selective expression, and chromosomal location of p57KIP2, we undertook the present study to search for potential mutations of KIP2 in a cohort of 126 tumors composed of 75 soft tissue sarcomas and 51 Wilms' tumors. The KIP2 gene was characterized by Southern blot, comparative multiplex PCR, PCR -single-strand conformational polymorphism, and DNA sequencing assays in these neoplasms. Deletions of the KIP2 gene or point mutations at the region encoding the cyclin-dependent kinase inhibitory domain were not found in the tumors analyzed. The absence of KIP2 mutations might indicate that these tumors arise due to defects at a closely linked but separate locus. Alternatively, similarly to the mouse homologue, inactivation of KIP2 could occur via genomic imprinting. 相似文献
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AS Cohen T Beaconsfield A al-Kutoubi CE Handler BE Glenville 《Canadian Metallurgical Quarterly》1996,61(4):1257-1259
A 35-year-old woman underwent reconstruction of her right pulmonary artery for treatment of acquired right pulmonary artery stenosis. The stenosis was secondary to tuberculosis causing both an extrinsic and an intrinsic obstructive component. After her reconstruction, the patient made an uneventful recovery, and perfusion to the right lung was subsequently restored. 相似文献
100.
BACKGROUND: Recent studies highlight the importance of compensatory stepping to preserve stability, and the spatial and temporal demands placed on the control of this reaction. Age-related changes in the control of stepping could greatly influence the risk of falling. The present study compares, in healthy elderly and young adults, the characteristics of compensatory stepping responses to unpredictable postural perturbations. METHODS: A moving platform was used to unpredictably perturb the upright stance of 14 naive, active and mobile subjects (5 aged 22 to 28 and 9 aged 65 to 81). The first 10 randomized trials (5 forward and 5 backward) were evaluated to allow a focus on reactions to relatively novel perturbations. The behavior of the subjects was not constrained. Forceplate and kinematic measures were used to evaluate the responses evoked by the brief (600 msec) platform translation. RESULTS: Subjects stepped in 98% of the trials. Although the elderly were less likely to execute a lateral anticipatory postural adjustment prior to foot-lift, the onset of swing-leg unloading tended to begin at the same time in the two age groups. There was remarkable similarity between the young and elderly in many other characteristics of the first step of the response. In spite of this similarity, the elderly subjects were twice as likely to take additional steps to regain stability (63% of trials for elderly). Moreover, in elderly subjects, the additional steps were often directed so as to preserve lateral stability, whereas the young rarely showed this tendency. CONCLUSIONS: Given the functional significance of base-of-support changes as a strategy for preserving stability and the age-related differences presently revealed, assessment of the capacity to preserve stability against unpredictable perturbation, and specific measures such as the occurrence or placement of multiple steps, may prove to be a significant predictor of falling risk and an important outcome in evaluating or developing intervention strategies to prevent falls. 相似文献