BACKGROUND AND PURPOSE The dynamics of leukocyte infiltration in human cerebral ischemia were studied using technetium-99m hexamethylpropyleneamine oxime (99mTc HMPAO)-labeled leukocyte brain single-photon emission computed tomography (SPECT). METHODS Twenty-two patients diagnosed as having hemispheric ischemic stroke were examined with 99mTc HMPAO brain SPECT for cerebral blood flow study an...

OBJECTIVE Leukocyte-associated immunoglobulin-like receptor-1 is an inhibitory receptor primarily expressed by immune cells. This study was undertaken to define the role of this molecule in osteoclast differentiation and rheumatoid arthritis. METHODS In vitro osteoclast assays were performed to characterize the role of Leukocyte-associated immunoglobulin-like receptor-1 in murine and human os...

Chemokines are small molecular weight peptides responsible for adhesion, activation, and recruitment of leukocytes into tissues. Leukocytes are thought to influence follicular atresia, ovulation, and luteal function. Many studies in recent years have focused attention on the characterization of leukocyte populations within the ovary, the importance of leukocyte-ovarian cell interactions, and mo...

BACKGROUND Extremely preterm infants are highly susceptible to bacterial infections but breast milk provides some protection. It is unknown if leukocyte numbers and subsets in milk differ between term and preterm breast milk. This study serially characterised leukocyte populations in breast milk of mothers of preterm and term infants using multicolour flow cytometry methods for extended differe...

The response of the leukocyte to leukocidin and its relevance to excitable and secreting tissues are described. New data are presented on the leukocyte membrane phosphatases and the action of tetraethylammonium ion (TEA) on the leukocyte. The leukocyte surface membrane lacks a cation-sensitive ATPase but possesses a potassium- and ouabain-sensitive p-nitrophenyl phosphatase. The p-nitrophenyl p...

In this study, we tested the hypothesis that reducing shear rates in postcapillary venules causes CD18-dependent, selectin-independent leukocyte rolling. Intravital microscopy was used to assess shear rate-dependent leukocyte rolling in 25- to 40-microns rat mesenteric venules. Pretreatment of animals with 25 mg/kg fucoidin, a carbohydrate moiety that binds to and inhibits selectin function, es...

We examined some of the metabolic events that regulate sensitizing cancer extract-induced leukocyte adherence inhi bition and found that human leukocytes adhere in a compara tively passive manner to glass in serum-free medium. Adher ence of leukocytes to glass did not require oxidative metabo lism, microtubules, microfilaments, or calcium entry, whereas leukocyte mobility excited by sensitizing...

Leukocyte recruitment requires leukocyte rolling, activation, firm adhesion, and transmigration. Injection of the proinflammatory cytokine TNF-alpha induces expression of E-selectin, interleukin-8, and other adhesion molecules and chemoattractants on the endothelial surface. TNF-alpha- treated CD18 null mouse cremaster muscle venules show increased leukocyte rolling velocity and reduced leukocy...

The selectins are a family of cell–cell adhesion proteins that participate in leukocyte–endothelial and leukocyte– platelet interactions [1–4]. The family consists of three members: P-selectin, expressed on activated endothelium and platelets; E-selectin, expressed on activated endothelium; and L-selectin, expressed on circulating leukocytes (Fig. 1). During the process of leukocyte emigration ...