Ischaemia-reperfusion injury (IRI) is caused by endothelial and subendothelial damage by neutrophil-derived oxidants. Vitamin C is an antioxidant which attenuates endothelial injury after IRI. Our aim was to evaluate the effect of oral vitamin C in the prevention of IRI in skeletal muscle. We used a model of cross-clamping (3 hours) and reperfusion (1 hour) of the cremaster muscle in rats. Musc...

Tumor necrosis factor(TNF) binds to 2 distinct cell-surface receptors: TNFreceptor-I (TNFR-I: p55) and TNFreceptor-II (TNFR-II: p75). TNFinduces leukocyte adhesion molecules on endothelial cells (ECs), which mediate 3 defined steps of the inflammatory response; namely, leukocyte rolling, firm adhesion, and transmigration. In this study, we have investigated the role of p75 in TNF– induced leuko...

The primary objectives of this study were 1) to determine the functional relationship between microvascular blood flow (Q) and arteriolar internal diameter (D) and 2) to determine whether this relationship conformed to a theoretical optimality prediction--that blood flow is proportional to the cube of the diameter (Q = kD3). Paired blood velocity and arteriolar diameter measurements in the crem...

TNF-α-converting enzyme (TACE, herein denoted as Adam17) proteolytically sheds several cell-surface inflammatory proteins, but the physiologic importance of the cleavage of these substrates from leukocyte subsets during inflammation is incompletely understood. In this study, we show that Adam17-null neutrophils have a 2-fold advantage in their initial recruitment during thioglycollate-induced p...

Protein kinase C (PKC)-θ is involved in T cell activation via regulating the avidity of the β(2) integrin LFA-1 in the immunological synapse. LFA-1 also mediates leukocyte adhesion. To investigate the role of PKC-θ in neutrophil adhesion, we performed intravital microscopy in cremaster venules of mice reconstituted with bone marrow from LysM-GFP(+) (wild-type [WT]) and PKC-θ gene-deficient (Prk...

Microvascular diameter and flow responses to peripheral and central sympathetic stimulation were measured in different segments of the arteriolar network in rat cremaster muscle. For peripheral stimulation, a bipolar electrode was placed on the internodal segment of the lumbar sympathetic chain between ganglia L1 and L2. For central stimulation, a bipolar electrode was stereotaxically implanted...

Previous work has shown that endogenous chemical mediators, of which histamine is the prototype, increase the permeability of blood vessels by causing gaps to appear between endothelial cells. In the present paper, morphologic and statistical evidence is presented, to suggest that endothelial cells contract under the influence of mediators, and that this contraction causes the formation of inte...

Intravascular sickling, red cell-endothelium interaction, and altered microvascular responses have been suggested to contribute to the pathophysiology of human sickle cell disease, but have never been demonstrated under in vivo flow. To address this issue, we have examined a transgenic mouse line, alphaHbetaSbetaS-Antilles [betaMDD] which has a combined high (78%) expression of beta S and beta ...

BACKGROUND During systemic inflammation, leucocytes are activated and extravasate into damaged tissue. Activation and recruitment are influenced by different mechanisms, including the interaction of leucocytes with platelets and neutrophil extracellular traps (NET) formation. Here, we investigated the molecular mechanism by which hydroxyethyl starch (HES 130/0.4) dampens systemic inflammation i...

OBJECTIVES To assess the value of external shielding of the testis during pelvic radiotherapy. MATERIAL AND METHODS Nineteen patients, receiving radiotherapy to the pelvis with the lower border of the field at the obturator foramen, were randomly selected. A 5 half value layer cerrobent shield was positioned at the inferior border of the field. The dose to the testis was measured with and wit...