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Plasma Factors (plasma + factor)
Selected AbstractsEndothelial cell expression of adhesion molecules is induced by fetal plasma from pregnancies with umbilical placental vascular diseaseBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2002Xin Wang Objective To test the hypothesis that local production with spill into the fetal circulation of factor(s) injurious to endothelium is responsible for the vascular pathology present when the umbilical artery Doppler study is abnormal. Expression of adhesion molecules is a feature of endothelial cell activation. Design Case,control study. Setting University teaching hospital. Samples Fetal plasma was collected from 27 normal pregnancies, 39 pregnancies with umbilical placental vascular disease defined by abnormal umbilical artery Doppler and 11 pregnancies with pre-eclampsia and normal umbilical artery Doppler. Methods Isolated and cultured human umbilical vein endothelial cells from normal pregnancies were incubated with fetal plasma from three study groups. mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were assessed by reverse transcription-polymerase chain reaction. To confirm the occurrence of this in vivo, we measured the levels of soluble fractions of sICAM-1, sVCAM-1 and sPECAM-1 in the fetal circulation in the fetal plasma used for endothelial cell incubation. Results The mRNA expression of ICAM-1 [median 1.1 (interquartile range 0.5,1.9) vs 0.7 (0.3,1.2), P < 0.05] and PECAM-1 [2.1 (1.2,3.0) vs 1.5 (0.7,2.1), P < 0.05] was significantly higher following incubation with fetal plasma from umbilical placental vascular disease compared with the normal group. There was no difference in the expression of VCAM-1 [1.2 (0.9,1.8) vs 1.1 (0.8,1.6), ns]. The group with maternal pre-eclampsia and normal umbilical artery Doppler did not differ from the normal group. In the umbilical placental vascular disease group, the results were similar in the presence or absence of pre-eclampsia. For soluble fractions of the adhesion molecules released into the fetal circulation, we found the levels (ng/mL) of sICAM-1 [median 248.5 (interquartile range 197.3,315.7) vs 174.2 (144.5,212.9), P < 0.05] and sPECAM-1 [9.3 (6.2,11.1) vs 6.1 (5.4,7.7), P < 0.05] in fetal plasma to be significantly increased in the presence of umbilical placental vascular disease compared with the normal. Conclusions Vascular disease in the fetal umbilical placental circulation is associated with an elevation in mRNA expression by endothelial cells of ICAM-1 and PECAM-1. Our study provides evidence for endothelial cell activation and dysfunction in umbilical placental vascular disease. We speculate that the plasma factor(s) affecting the vessels of the umbilical villous tree is locally released by the trophoblast. The occurrence of the maternal syndrome of pre-eclampsia appears to be independent of this. [source] Removal of uremic plasma factors using different dialysis modalitiesHEMODIALYSIS INTERNATIONAL, Issue 2006Mario BONOMINI No abstract is available for this article. [source] Inhibitory effect of osmotic concentration, potassium and pH on motility of the sperm of the North American burbot Lota lota maculosaJOURNAL OF FISH BIOLOGY, Issue 1 2007M. D. Zuccarelli Seminal plasma factors maintaining North American (NA) burbot Lota lota maculosa sperm quiescent were examined. Sperm were diluted into buffered saline solutions of various compositions and motility assessed. After 1 h in these solutions at 10° C, aliquots of the suspension were diluted with tap water and motility again assessed. Dilution of sperm in an incubation solution containing Ca2+ in the absence of K+ initiated sperm motility resulting in low motility when sperm were subsequently diluted in tap water. Incubation solutions with osmolalities >200 mOsm kg,1 and containing 12·5 mM K+ prevented the onset of sperm motility and were associated with maximal sperm motility upon dilution in tap water. Sperm maintained at lower osmolalities exhibited limited motility upon dilution in tap water indicating interdependence between K+ and osmolality in maintaining sperm quiescent in the presence of Ca2+. Sperm kept in incubation solution at pH values < c. 7·5 for 1 h demonstrated reduced motility when subsequently diluted in tap water. That motility of sperm was pH sensitive was further indicated by CO2 inhibition of motility. Therefore, NA burbot sperm are probably maintained in an immotile state, yet with potential for motility, by combination of high K+, osmolality and possibly pH. The results from this study differ from published information on sperm quiescence in the temporally and geographically distinct Eurasian burbot Lota lota lota. [source] The Pancreas as a Source of Cardiovascular Cell Activating FactorsMICROCIRCULATION, Issue 3 2000ERIK B. KISTLER ABSTRACT Objective: Physiological shock leads to elevated levels of plasma factors that activate circulating leukocytes and endothelial cells, thereby compromising microvascular functions. The nature and source of these plasma-derived activators are unknown. To examine the possible origin of these factors, we homogenized rat internal organs and measured their activity on cardiovascular cells in vivo and in vitro. Methods: Fresh tissue samples from small intestine, spleen, heart, liver, kidney, adrenals, and pancreas were homogenized. Their ability to induce leukocyte pseudopod formation and nitroblue tetrazolium (NBT) reduction was tested and their impact in vivo on blood pressure, survival, and microvascular cell injury was examined. Results: A dramatic increase (p < 0.001) in leukocyte activation compared to controls was observed with pancreas homogenate but not with homogenates from the other organs. Leukocyte activation was induced by homogenates of other tissues only after prior incubation with substimulatory concentrations of pancreatic homogenate. Pancreatic serine proteases, trypsin and chymotrypsin, which did not stimulate leukocytes, also generated activity from other tissues. Leukocyte pseudopod formation could be significantly inhibited by adding the serine protease inhibitor 6-amidino-2-naphthyl p -guanidinobenzoate dimethanesulfonate (ANGD) during tissue homogenization (p < 0.001). Injection of pancreatic homogenate into rats led to increased plasma hydrogen peroxide levels and an instantaneous drop in mean arterial pressure that was often lethal. These responses were prevented by prior infusion of ANGD (p < 0.001). Intravital microscopy of the rat mesentery confirmed that superfusion of filtered pancreatic homogenate leads to significant increases in cell death (p < 0.05), as detected by propidium iodide, and hydrogen peroxide formation (p < 0.05), as determined by dichlorofluorescein diacetate (DCFH) fluorescence. Conclusion: These results suggest that pancreatic enzymes attack tissue and generate cellular activators that are associated with organ dysfunction in shock. [source] Increase of Integrin-Linked Kinase Activity in Cultured Podocytes upon Stimulation with Plasma from Patients with Recurrent FSGSAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2008M. Hattori Recurrent focal segmental glomerulosclerosis (FSGS) is a major challenge in the field of transplantation. Integrin-linked kinase (ILK) has emerged as a key mediator of podocyte,glomerular basement membrane (GBM) interactions. To clarify the involvement of plasma factors in FSGS recurrence, we examined the effects of plasma from FSGS patients with or without posttransplant recurrence on cultured podocytes, focusing particularly on ILK activity. Podocytes from a conditionally immortalized mouse podocyte cell line were treated with plasma from 11 FSGS patients, and ILK activity was determined using an immune complex kinase assay. Treatment with plasma from three patients with recurrence induced an increase in ILK activity. In contrast, no increase in ILK activity was observed in cultured podocytes treated with plasma from the remaining three patients with recurrence and five patients without recurrence. Cultured podocytes treated with plasma that induced ILK activity showed alterations of focal contact and detachment from the laminin matrix. In conclusion, this preliminary study provides experimental evidence suggesting the possible presence of circulating toxic factors in the plasma of some patients with recurrent FSGS, which induce an increase in podocyte ILK activity that may lead to the detachment of podocytes from the GBM. [source] | ||||||||||