Microvascular research
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Microvascular research · May 2014
Comparative StudyEndocan is useful biomarker of survival and severity in sepsis.
Coagulation abnormalities which occur as a consequence of endothelial changes are recognized as diagnostic criteria for sepsis, but significance of these changes in the outcome prognosis and prediction of the course of sepsis is still not accurately defined. ⋯ Results of our study show that endocan can be used as strong and significant predictor of sepsis severity and outcome, perhaps even better than SOFA and APACHE II scores.
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Microvascular research · Jan 2014
Transient oxygen-glucose deprivation sensitizes brain capillary endothelial cells to rtPA at 4h of reoxygenation.
Thrombolysis treatment of acute ischemic stroke is limited by the pro-edematous and hemorrhagic effects exerted by reperfusion, which disrupts the blood-brain barrier (BBB) capillary endothelium in the infarct core. Most studies of the ischemic BBB overlook the complexity of the penumbral area, where the affected brain cells are still viable following deprivation. Our present objective was to examine in vitro the kinetic impact of reoxygenation on the integrity of ischemic BBB cells after oxygen-glucose deprivation. ⋯ Interestingly, the reoxygenated BBB broke down with aggravated tight junction disruption when exposed to rtPA only at 4h after reoxygenation. Moreover, this breakdown was enhanced by 50% when ischemic glial cells were present during the first hours of reoxygenation. Our results suggest that post-stroke reoxygenation enables retrieval of the barrier function of brain capillary endothelium when in a non-necrotic environment, but may sensitize it to rtPA at the 4-hour time point, when both endothelial breakdown mechanisms and glial secretions could be identified and targeted in a therapeutical perspective.
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Microvascular research · Jan 2014
Effects of non-leukocyte-reduced and leukocyte-reduced packed red blood cell transfusions on oxygenation of rat spinotrapezius muscle.
Leukoreduction of blood used for transfusion alleviates febrile transfusion reactions, graft versus host disease and alloimmunization to leukocyte antigen. However, the actual clinical benefit of leukoreduction in terms of microcirculatory tissue O2 delivery after packed red blood cell (pRBC) transfusion has not been investigated. As such, the aim of this study was to determine the effects of non-leukoreduced (NLR) and leukoreduced (LR) fresh pRBC transfusion on interstitial oxygenation in anesthetized male Sprague-Dawley rats. ⋯ These data suggest that transfusion of fresh NLR-pRBCs may negatively affect tissue oxygenation via enhanced leukocyte influx and decreased O2 delivery. They also suggest that leukocytes diminish the capability of transfused pRBCs to increase cardiac output. As such, transfusion of LR-pRBCs may be less deleterious on tissue PO2 levels than NLR-pRBCs although a concomitantly greater increase in ABP may accompany transfusion of LR-pRBCs.
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Microvascular research · Nov 2013
Early adverse changes in liver microvascular circulation during experimental septic shock are not linked to an absolute nitric oxide deficit.
Nitric oxide (NO) is believed to play a key role in adverse microvascular changes during sepsis. A deficit in NO has been evoked as a potential mechanism of microcirculatory deterioration in the early phase of septic shock. The aim of this study was to evaluate simultaneously and continuously both hepatic microcirculation and local NO production during early experimental sepsis. ⋯ In septic animals, whereas a fall in microcirculatory perfusion was noted as early as 2h after CLP, NO concentration remained stable and further increased after the onset of shock. At this time, inducible NO synthase was the only isoform significantly elevated. In this non-resuscitated experimental model of sepsis, an absolute liver deficit of NO could not explain the early adverse changes in the local microvascular system.
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Microvascular research · Nov 2013
Blockade by phosphorothioate aptamers of advanced glycation end products-induced damage in cultured pericytes and endothelial cells.
Advanced glycation end products (AGEs) not only inhibit DNA synthesis of retinal pericytes, but also elicit vascular hyperpermeability, pathological angiogenesis, and thrombogenic reactions by inducing vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) through the interaction with the receptor for AGEs (RAGE), thereby being involved in the pathogenesis of diabetic retinopathy. In this study, we screened novel phosphorothioate-modified aptamers directed against AGEs (AGEs-thioaptamers) using a combinatorial chemistry in vitro, and examined whether these aptamers could inhibit the AGE-induced damage in both retinal pericytes and human umbilical vein endothelial cells (HUVECs). We identified 11 AGEs-thioaptamers; among them, clones #4, #7s and #9s aptamers had higher binding affinity to AGEs-human serum albumin (HSA) than the others. ⋯ Quartz crystal microbalance analysis confirmed that #4s aptamer dose-dependently inhibited the binding of AGEs-HSA to RAGE. Our present study demonstrated that AGEs-thioaptamers could inhibit the harmful effects of AGEs in pericytes and HUVEC by suppressing the binding of AGEs to RAGE. Blockade by AGEs-thioaptamers of the AGEs-RAGE axis might be a novel therapeutic strategy for diabetic retinopathy.