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排序方式: 共有431条查询结果,搜索用时 15 毫秒
1.
2.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
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Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
5.
Akira Warashina Zheng-Yao Jiang Tatsuya Ogura 《Pflügers Archiv : European journal of physiology》1988,411(1):88-93
Effects of toxins III and IV (ATX III and IV) from the sea anemoneAnemonia sulcata on the Na current of crayfish giant axons were studied. Both toxins slowed the inactivation of Na channels, producing a maintained Na current during a depolarizing voltage pulse. Using the intensity of the toxin-induced maintained current as an index for the fraction of Na channels to which toxin is bound, the toxin association and dissociation kinetics were analyzed. The dissociation rate of ATX III was increased by two orders of magnitudes by depolarizing the membrane from –70 to –40mV. This increase of the dissociation rate caused a marked decrease in the binding rate of ATX III to Na channels in the same potential range. ATX IV exhibited association and dissociation kinetics that had a potential dependency quite similar to that of ATX III in spite of different ionic charge distribution in these two toxins. The results support the view that the potential-dependent kinetics of these toxins are not due to an electrostatic interaction between the ionic charges of toxins and the membrane potential but result from a modulation of the binding energy depending on the gate configuration of the Na channel. 相似文献
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We constructed a chromaffin cell model for analysis of stimulation–secretion coupling in computer simulation studies. The model includes mechanisms involved in the excitatory synapse, voltage-dependent Na+, K+ and Ca2+ channels, Ca2+-activated K+ channels (SK type), buffered Ca2+ diffusion, Ca2+ extrusion, fluorescent Ca2+ indicators and Ca2+-triggered exocytosis. Calculations of the modeled mechanisms were carried out using the NEURON simulation environment (Hines and Carnevale, Neural Computation 9:1179–1209, 1997). A set of parameter values was determined so as to fit basic experimental results reported in the literature. The model was also applied to simulate our experimental results obtained from chromaffin cells in the perfused rat adrenal medulla. Observed profiles of Ca2+responses induced by electrically stimulating the splanchnic nerve with various frequencies (1–50 Hz) were adequately simulated with minor readjustments of parameter values for Ca2+influx and extrusion. Secretory responses measured at the same time as the Ca2+responses were also simulated with consideration of a time constant to detect catecholamines in the experiment. Similarly, model simulations reproduced both Ca2+responses and secretory responses evoked by elevations of the extracellular K+ concentration for different periods. The results suggest that the presented model provides a useful tool for analyzing and predicting quantitative relations in various events occurring in stimulation–secretion coupling in chromaffin cells. 相似文献
9.
The vasa vasorum and angioplasty 总被引:2,自引:0,他引:2
Cragg AH; Einzig S; Rysavy JA; Castaneda-Zuniga WR; Borgwardt B; Amplatz K 《Radiology》1983,148(1):75-80
Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances. 相似文献
10.
Aberrant crypt focus promotion and glucose intolerance: correlation in the rat across diets differing in fat, n-3 fatty acids and energy 总被引:1,自引:0,他引:1
Koohestani N; Chia MC; Pham NA; Tran TT; Minkin S; Wolever TM; Bruce WR 《Carcinogenesis》1998,19(9):1679-1684
McKeown-Eyssen (Cancer Epidemiol. Biomarkers Prevent., 3, 687-695, 1994)
and Giovannucci (Cancer Causes Control, 6, 164-179, 1995), noting the
striking similarity in lifestyle risk factors for colorectal cancer and
insulin resistance, proposed that the hyperinsulinemia, glycemia and
hypertriglyceridemia associated with insulin resistance promotes colon
cancer. To compare the effect of diet on colon cancer promotion and insulin
resistance in the F344 rat, we assessed the effect of fat, n-3 fatty acids
and energy in pairwise comparisons on average size of aberrant crypt foci
(ACF) and on glucose intolerance in the same animals in a single
experiment. Diets high in fat and energy increased and diets with increased
n-3 fatty acids and calorie restriction decreased both ACF growth and
glucose intolerance compared with control diets. The measures of promotion
of colon cancer and insulin resistance were strongly correlated (n = 98, r
= 0.67, P < 0.001). In addition, both were highly correlated with daily
energy intake (r = 0.62 and 0.66) and were also correlated with basal
(post-prandial) insulin, glucose and triglycerides (r = 0.31-0.53, P <
0.01). We concluded that ACF growth and glucose intolerance are correlated
for a wide range of diets and that increased circulating energy (glucose
and triglycerides) may lead to both colon cancer promotion and insulin
resistance.
相似文献