In vitro studies indicate that oxidatively modified low density lipoprotein (oxLDL) promotes leukocyte adhesion to the vascular endothelium, a constant feature of early atherogenesis. Using intravital fluorescence microscopy in the dorsal skinfold chamber model in awake Syrian golden hamsters, we studied whether (a) oxLDL elicits leukocyte/endothelium interaction in vivo, and whether (b) leukot...

MRL/fas(lpr) mice are affected by a systemic autoimmune disease that results in widespread leukocytic infiltration of the vasculature, including in the skin. The molecular pathways responsible for this leukocyte recruitment are poorly understood. Therefore, the aim of these experiments was to examine the mechanisms of leukocyte trafficking in the dermal microvasculature of MRL/fas(lpr) mice. In...

Whereas many differential leukocyte count methods for high somatic cell count (SCC) milk from mastitic cows are available, only a few have been developed for low SCC milk. We have developed a flow cytometric differential leukocyte count method for low SCC milk. The procedure consists of 1) 1.5 ml of diluted milk sample (30%, vol/vol dilution with PBS), 2) centrifugation, 3) leukocyte labeling w...

We have investigated the effects of LPS from Escherichia coli, lipoteichoic acid (LTA), and peptidoglycan (PepG) from Staphylococcus aureus, and live S. aureus on leukocyte-endothelial interactions in vivo using intravital microscopy to visualize muscle microvasculature. Systemic vs local administration of LPS induced very different responses. Local administration of LPS into muscle induced sig...

The study of the effect of leukocyte adhesion on blood flow in small vessels is of primary interest to understand the resistance changes in venular microcirculation. Available computational fluid dynamic studies provide information on the effect of leukocyte adhesion when blood is considered as a homogeneous Newtonian fluid. In the present work we aim to understand the effect of leukocyte adhes...

The mechanisms mediating leukocyte recruitment into the cerebral nervous system during inflammation are still poorly understood. The objective of this study was to investigate the leukocyte recruitment in the brain microcirculation by intravital microscopy. Superfusion of the brain with artificial cerebrospinal fluid did not induce leukocyte rolling or adhesion. However, intraperitoneal tumor n...

Ropivacaine, a new local anesthetic, is currently being investigated for the treatment of ulcerative colitis, with promising results so far. The aim of this study was to examine anti-inflammatory properties of ropivacaine with regard to its effects on vascular permeability and inflammatory leukocyte behavior in vivo. The effects on leukocyte rolling, firm adhesion and vascular permeability were...

Thrombosis promotes leukocyte infiltration into inflamed tissues, leading to organ injury in a broad range of diseases; however, the mechanisms by which thrombi guide leukocytes to sites of vascular injury remain ill-defined. Using mouse models of endothelial injury (traumatic or ischemia reperfusion), we demonstrate a distinct process of leukocyte recruitment, termed "directed intravascular mi...

BACKGROUND AND PURPOSE Tacrolimus, an immunosuppressant agent, has been shown to reduce tissue injury and leukocyte accumulation after transient ischemia. This study was designed to evaluate quantitatively the inhibitory effects of tacrolimus on leukocyte rolling and on subsequent leukocyte accumulation in vivo after transient retinal ischemia and the protective effects of tacrolimus on ischemi...

Leukocyte-endothelium interactions are diminished in tumors. It is reported here that, in a tumor-free in vivo model, angiogenic factors can down-regulate leukocyte adhesion to endothelium. Slow releasing pellets were loaded with either basic fibroblast growth factor (bFGF), vascular endothelial cell growth factor (VEGF) or vehicle alone and were placed in the scrotum of mice. After 3 days, a s...