Leukocyte Adhesion Deficiency Type II (LAD II) is a recently described syndrome and the two patients with this defect lack fucosylated glycoconjugates. These glycoconjugates include the selectin ligand, sialyl Lewis X , and various fucosylated blood group antigens. To date, the molecular anomaly in these patients has not been identified. We localized the defect in LAD II to the de novo pathway of GDPfucose biosynthesis, by inducing cell-surface expression of fucosylated glycoconjugates after exposure of lymphoblastoid cell lines from the LAD II patients to exogenous fucose. This defect is not restricted to hematopoietic cells, since similar findings were elicited in both human umbilical vein endothelial cells (HUVEC) and fibroblasts derived from an affected abortus. We have used these LAD II endothelial cells to examine the consequence of fucosylation of endothelial cells on the rolling of normal neutrophils in an in vitro assay. Neutrophil rolling on LPS-treated normal and LAD II HUVEC was inhibited by an E-selectin monoclonal antibody at both high and low shear rates. LAD II HUVEC lacking fucosylated glycoproteins supported leukocyte rolling to a similar degree as normal HUVEC or LAD II cells that were fucose-fed. At low shear rates, an L-selectin antibody inhibited neutrophil rolling to a similar degree whether the LAD II cells had been fucose-fed or not. These findings suggest that fucosylation of nonlymphoid endothelial cells does not play a major role in neutrophil rolling and that fucose is not a critical moiety on the L-selectin ligand(s) on endothelial cells of the systemic vasculature. ( J. Clin. Invest.

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Purpose: To evaluate the effect of the fourth-generation fluoroquinolones gatifloxacin and moxifloxacin on the rate of corneal epithelial cell migration and corneal cell proliferation in vitro. These processes are important steps in ocular surface healing.Methods: Epithelial cell migration measurements were made in primary cultures of rabbit corneal epithelial cells treated with gatifloxacin, moxifloxacin, ciprofloxacin, ofloxacin, and levofloxacin. Circular defects were made in confluent epithelial cell cultures that were continuously treated with the fluoroquinolones at 0.2-1.0 mmol/L in culture medium at 37°C for up to 73 hours. Digital images of the defects were made at approximately 10-to 15-hour intervals and the rate of decrease in defect area was calculated. The effects of fluoroquinolones on cell proliferation were measured with rabbit corneal epithelial cells, rabbit corneal stromal fibroblasts, and human corneal epithelial cells via metabolic reduction using a redox indicator dye.Results: All the fluoroquinolones evaluated caused a concentrationdependent decrease in the rate of corneal epithelial cell migration. When we compared the 2 fourth-generation fluoroquinolones, moxifloxacin and gatifloxacin had approximately equal activity at the lower concentrations. However, at higher concentrations, moxifloxacin was a stronger inhibitor of corneal epithelial cell migration than gatifloxacin when evaluated at equimolar concentrations. In the more sensitive human cell cultures, cell proliferation was inhibited less by gatifloxacin than by moxifloxacin.Conclusions: All tested fluoroquinolones inhibited the processes involved in ocular surface healing, epithelial cell migration and proliferation, in a concentration-dependent manner. Comparing 2 fourthgeneration fluoroquinolones, we found that gatifloxacin was less inhibitory to the processes involved in corneal reepithelialization.

P-selectin is one of the key early mediators of leukocyte adhesion in inflammatory conditions. This report examines the role of P-selectin in a neutrophil- and platelet-mediated model of glomerulonephritis (the concanavalin A [con A] model). The administration of neutralizing anti-P-selectin antibody (PB 1.3) reduced the platelet influx at 10 min (P < 0.05) and was associated with a 60% reduction in the neutrophil infiltrate and a 50% reduction in the number of oxidant-producing cells at 3 h within glomeruli. No effect on glomerular monocyte-macrophage accumulation was observed, and proteinuria was reduced by 20% but did not reach significance. It is concluded that P-selectin plays an important role in mediating the neutrophil and platelet accumulation in this model and likely has a role in mediating the glomerular injury.