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71.
M. Porta C. Townsend G. M. Clover M. Nanson A. R. Alderson A. McCraw E. M. Kohner 《Diabetologia》1981,20(6):597-601
Summary Two aspects of endothelial cell function were examined in two matched groups of male insulin-dependent diabetics, six with background retinopathy and seven without retinopathy. Leakage of fluorescein from the retinal capillaries was estimated by vitreous fluorophotometry. In addition, factors VIII/von Willebrand (vWF) and VIII-related antigen (VIII-RAG), which are synthesized by the endothelial cells, were measured, together with VIII-antihaemophilic factor (VIII-AHF). The patients without retinopathy had normal leakage of fluorescein in the macula (mean ± SEM: 1.10±0.10 g × 10-8/ml) and the posterior vitreous (0.45±0.11 g × 10-8/ml), and normal circulating levels of vWF (123% of a normal reference plasma ± 18%), VIII-RAG (137±14%) and VIII-AHF (112±18%). In contrast, the patients with background retinopathy showed higher leakage of fluorescein in the macula (6.34±1.74 g ×10-8/ml; p<0.01), and the posterior vitreous (3.09±0.94 g ×10-8/ml; p<0.02), as well as increased levels of vWF (177±16%; p<0.05). There was a trend towards increased VIII-RAG (195±24%; p<0.1), but not VIII-AHF (126 ±13%). Alterations of endothelial cell function thus accompany the development of retinopathy. It cannot be said from the present study whether these alterations also precede the appearance of retinopathy. 相似文献
72.
血管性血友病因子基因19内含子MspⅠ多态性与冠心病危险因素的关系 总被引:2,自引:0,他引:2
目的 :探讨血管性血友病因子 (vonWillebrandfactor ,vWF)基因 19内含子MspⅠ多态性与冠心病(CHD)危险因素的关系。方法 :应用聚合酶链反应 (PCR)技术结合MspⅠ酶切分析等 ,测定了 10 9例CHD患者和 10 4例健康对照者vWF基因 19内含子MspⅠ限制性片段长度多态性频率 ,同时应用酶联免疫吸附测定(ELISA)技术测定血浆vWF水平。结果 :①vWF基因 19内含子MspⅠ基因型与高血压间差异有统计学意义 ( P<0 .0 5 ) ,而与性别、年龄、糖尿病、高脂血症和吸烟等危险因素差异无统计学意义 (P >0 .0 5 )。②vWF基因 19内含子MspⅠ基因型在高危组和低危组的分布差异无统计学意义 (P >0 .0 5 )。③伴高血压患者中M-/M-基因型与M+/M+基因型和M+/M-基因型的血浆vWF水平之间无统计学意义 (P >0 .0 5 )。结论 :vWF基因 19内含子MspⅠ多态性可能与CHD的危险因素之一高血压有关。 相似文献
73.
The relationships of three measurements of the factor VIII/von Willebrand factor (VWF) complex (factor VIII activity, FVIIIc (one-stage assay); VWF antigen, VWF Ag (ELISA); and VWF activity, VWF act, measured by a recently-developed ELISA) to major ischaemic heart disease (IHD) events were studied in 1997 men aged 49-65 years, in the second phase of the Caerphilly Heart Study. These variables were related using logistic regression analysis to myocardial infarction or IHD death, which occurred in 129 men during an average follow-up period of 61 months. All three measurements were highly correlated (r = 0.63-0.77), and each was significantly associated with incident major IHD on univariate analyses (relative odds in highest fifth compared to lowest fifth, 1.68-1.90; P = 0.028-0.006) and on multivariate analyses adjusting for major IHD risk factors and for baseline IHD. Neither FVIIIc nor VWF act was significantly related to incident IHD following adjustment for VWF Ag. We therefore suggest that the associations between these three measurements of the factor VIII/VWF complex and incident IHD might have at least three explanations: VWF Ag is a marker of arterial endothelial disturbance; VWF act promotes platelet adhesion/aggregation and hence the platelet component of arterial thrombosis; and FVIIIc promotes fibrin formation and hence the fibrin component of arterial thrombosis. 相似文献
74.
The endothelium plays a pivotal role in the theological regulation of blood flow by the secretion of vasoactive factors.
The interaction between shear forces and the endothelium is determined by the mechanical properties of the endothelial cell
layer which are associated with intercellular junctions. Cell-cell contacts could therefore modulate the secretion of vasocative
factors in response to theological stimuli. We investigated the relationship between intercellular junctions and the secretion of the vasoconstrictor peptide endothelin and the coagulation co-factor von Willebrand factor (vWF). Human
umbilical vein endothelial cells (HUVECs) were used as in vitro endothelial model system. Intercellular junctions were reversibly
disrupted by calcium chelation or hypertonic stress; alternatively, the formation of intercellular junctions was inhibited
by culturing the cells in suspension or by plating them in the presence of an inhibitory anti-VE-cadherin antibody. The opening
of intercellular junctions was verified by assessing transmonolayer electrical resistance (TMR) and immunofluorescence morphology.
The concentration of endothelin and vWF was measured in the cell culture supernatants using specific ELISAs. The secretion
of endothelin was inhibited by EGTA (5 mM) and stimulated by incubation with tumor necrosis factor α (TNFα, 40 ng/ml). Treatment
with hypertonic medium (glycerol, 1200 mosmol/l) for 10 minutes opened intercellular junctions and markedly reduced the secretion
of endothelin. HUVECs in suspension culture did not secrete endothelin and failed to respond to TNFα, but readily resumed
these functions upon forming a new monolayer on plastic. The reconstitution of intercellular junctions after suspension culture
could be inhibited using a specific anti-VE-cadherin antibody. This antibody, but not a non-specific anti-humanIgG antibody
reduced endothelin secretion. The secretion of von Willebrand Factor was less dependent on intercellular junctions. The opening
of intercellular junctions did not induce cell death, since the cells continued to exclude trypan blue. The results of this
study suggest a novel and potentially pathophysiologically/clinically relevant correlation between intercellular junctions
and the secretion of endothelin in endothelial cells.
Received: 17 December 1999, Returned for revision: 20 January 2000, Revision received: 14 February 2000, Accepted: 2 March
2000 相似文献
75.
76.
Osamu Kainuma Yasushi Ito Tetsushi Taniguchi Takanori Shimizu Hisashi Nakada Yoko Date Tsuyoshi Hara 《Journal of gastroenterology》1996,31(3):460-464
We report a case of somatostatinoma of the ampulla of Vater associated with von Recklinghausen's disease in a 44-year-old
woman. On admission the patient was jaundiced, and percutaneous Cholangiodrainage was performed. Cholangiography revealed
stenosis of the common bile duct at the lower end Duodenoscopy showed a yellowish tumor of the ampulla of Vater, and the biopsy
specimens showed no malignant cells. Pylorus-preserving pancreaticoduodenectomy was performed. Histologically, the tumor was
composed of small round cells with a solid or trabecular pattern and with multiple psammoma bodies. Immunohistochemical examination
showed that the tumor cells stained for somatostatin. Genomic examination showed neither K-ras nor p53 gene mutations of the
resected specimen. 相似文献
77.
Lippi G Franchini M Salvagno GL Montagnana M Poli G Guidi GC 《Journal of thrombosis and thrombolysis》2008,26(2):150-153
Background The laboratory diagnosis of von Willebrand Factor (VWF) deficiencies includes qualitative and quantitative measurements of
VWF and clotting factor VIII (FVIII). Since the FVIII activity is frequently normal in patients with mild type 1 or 2 von
Willebrand disease (VWD), there is controversy whether FVIII testing should accompany VWF Antigen (VWF:Ag) assay. Methods The aim of this study was to explore the correlation between VWF:Ag, VWF ristocetin cofactor activity (VWF:RCo) and FVIII
in 213 consecutive patients undergoing screening for VWD. Results Forty-six patients were identified with VWF:Ag levels lower than the diagnostic threshold (54 IU/dl). A significant correlation
was observed between VWF:Ag and VWF:RCo (r = 0.892; p < 0.001), VWF:Ag and FVIII (r = 0.834; p < 0.001), VWF:RCo and FVIII (r = 0.758; p < 0.001). Receiver operating characteristic curve analysis of the VWF:Ag assay revealed an area under the curve of 0.978
and 0.957 for detecting life-threatening values of FVIII (<30 IU/dl) and VWF:RCo (<40 IU/dl), respectively. The negative and
positive predictive values at the VWF:Ag threshold value of 54 IU/dl were 100% and 33% for detecting life-threatening FVIII
deficiencies, 94% and 80% for identifying abnormal values of VWF:RCo. Conclusions Due to the excellent correlation between VWF:Ag and FVIII and to the diagnostic efficiency of VWF:Ag for identifying abnormal
FVIII levels in patients with VWF deficiency, routine measurement of FVIII may not be necessary in the initial screening of
patients with suspected VWD. However, the limited negative predictive value of VWF:Ag for identifying type 2 VWD does not
allow to eliminate VWF:RCo or VWF:FVIIIB assays from the diagnostic workout. 相似文献
78.
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