Microvascular research
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Microvascular research · Mar 2015
Skin autofluorescence is associated with carotid intima-media thickness, diabetic microangiopathy, and long-lasting metabolic control in type 1 diabetic patients. Results from Poznan Prospective Study.
Our aim was to assess the association between skin autofluorescence (AF) related to advanced glycation end products (AGEs) accumulation and long-term metabolic control, microvascular complications and carotid intima-media thickness (IMT) in an observational cohort of type 1 diabetes (DM1). ⋯ Skin AF is a reliable marker of past glycemic control of diabetes. Increased accumulation of AGEs is related to the presence of diabetic microangiopathy as well as subclinical macroangiopathy in patients with type 1.
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Microvascular research · Mar 2015
Normobaric hyperoxia alters the microcirculation in healthy volunteers.
The use of high concentrations of inhaled oxygen has been associated with adverse effects but recent data suggest a potential therapeutic role of normobaric hyperoxia (NH) in sepsis and cerebral ischemia. Hyperoxia may induce vasoconstriction and alter endothelial function, so we evaluated its effects on the microcirculation in 40 healthy adult volunteers using side-stream dark field (SDF) video-microscopy on the sublingual area and near-infrared spectroscopy (NIRS) on the thenar eminence. In a first group of volunteers (n=18), measurements were taken every 30 min: at baseline in air, during NH (close to 100% oxygen via a non-rebreathing mask) and during recovery in air. ⋯ Thirty minutes after return to air, PPV, PVD, PSVD and MFI remained partially altered. During NH, NIRS descending slope and NIRS muscle oxygen consumption (VO2) decreased from 8.5 to 7.9%/s and 127 to 103 units, respectively, in the first group and from 10.7 to 9.4%/s and 150 to 115 units in the second group. NH, therefore, alters the microcirculation in healthy subjects, decreasing capillary perfusion and VO2 and increasing the heterogeneity of the perfusion.
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Microvascular research · Jan 2015
Impaired coronary microvascular and left ventricular diastolic function in patients with inflammatory bowel disease.
Increased incidence of coronary vascular events in patients with inflammatory bowel disease (IBD) is known. However, the association between coronary microvascular function and IBD has not been fully defined. We aimed to investigate whether coronary flow reserve (CFR) and left ventricular diastolic function were impaired in IBD patients. ⋯ CFR, reflecting coronary microvascular function, is impaired in patients with IBD. CFR and left ventricular diastolic function parameters are well correlated with hs-CRP.
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Microvascular research · Jan 2015
Desmopressin improves intestinal functional capillary density and decreases leukocyte activation in experimental endotoxemia.
Blood flow to the intestine is decreased in sepsis in favor of vital organs resulting in ischemic damage of the gut mucosa. Once the mucosa is damaged, increased translocation of intestinal bacteria to the systemic circulation may occur. This in turn aggravates the inflammatory response contributing to the development of multi-organ failure. Desmopressin is a synthetic analog of vasopressin, an anti-diuretic hormone which has been shown to induce vasodilation and is thought to be implicated in immunomodulation. In this study, we investigate the effects of desmopressin on the intestinal microcirculation during sepsis in an experimental endotoxemia model in rats using intravital microscopy. In addition, we investigate the effects of desmopressin on systemic inflammation. ⋯ Desmopressin administration improved intestinal capillary perfusion and reduced inflammatory response in rat endotoxemia.
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Microvascular research · Sep 2014
Comparative StudyEffects of a hemoglobin-based oxygen carrier (HBOC-201) and derivatives with altered oxygen affinity and viscosity on systemic and microcirculatory variables in a top-load rat model.
The effects of a polymerized bovine hemoglobin-based oxygen carrier (HBOC) and two derivatives on arteriolar vasoactivity and tissue oxygen tension were explored by administering HBOC in a dose-response fashion to normovolemic rats. The effect of oxygen affinity (P50) and viscosity was also explored, where the P50 and viscosity of the parent compound (HBOC-201) and its modifications (MP50 and LP50A) were as follows: 40mmHg and 3.0cP (HBOC-20l); 18mmHg and 4.4cP (MP50); and 17mmHg and 12.1cP (LP50A). Anesthetized male Sprague-Dawley rats (N=32) were randomized to receive one of the HBOC solutions, and were administered four infusions that increased in concentration for each dose (2, 22, 230 and 780mg/kg, IV). ⋯ There were no significant changes in arteriolar diameters at any dose for any group. Interstitial partial pressure of oxygen (ISF PO2) remained unchanged for HBOC-201, MP50 and HSA, but LP50A caused a significant decrease in ISF PO2 compared to baseline after Doses 3 and 4. In conclusion, there was no evidence that HBOC-201 would perform better with increased oxygen affinity (40 to 18mmHg) or viscosity (3.0 to 4.4cP).