OBJECTIVE The aim of this study was to fabricate a novel composite porous scaffold by blending chitosan and gamma-poly(glutamic acid) (gamma-PGA) for the sustained delivery of rhBMP-2. METHODS Chitosan and gamma-PGA were blended to fabricate a novel porous scaffold by the freeze-gelation method. For comparison, scaffolds made of freeze-dried chitosan, freeze-dried PLLA, and freeze-gelled chit...

Endothelial cells (EC) synthesize and secrete von Willebrand factor (vWF), a multimeric glycoprotein required for normal hemostasis. Within human endothelial cells, vWF multimers of extremely high molecular weight are stored in rod-shaped organelles known as Weibel-Palade bodies. Inflammatory mediators, such as interleukin-1, induce in vitro a variety of procoagulant responses by EC, including ...

To obtain insight in the capacity of the lipopolysaccharide (LPS)-tolerant host to produce interferon (IFN)-gamma and to respond to this cytokine, whole blood was obtained from healthy humans before and 4 h after intravenous injection of LPS (4 ng/kg) and stimulated ex vivo. LPS exposure in vivo resulted in a diminished capacity to produce IFN-gamma after restimulation with LPS, together with a...

The influence of purified recombinant human tumor necrosis factor-alpha (rhuTNF-alpha) was assessed alone and in combination with purified recombinant human interferon gamma (rhuIFN-gamma) for its effects on enhancing release from human monocytes of activities that stimulate colony formation by granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells. R...

1. Amino acids, particularly glutamate, gamma-aminobutyrate, aspartate and glycine, were released from rat brain slices on incubation with protoveratrine (especially in a Ca(2+)-deficient medium) or with ouabain or in the absence of glucose. Release was partially or wholly suppressed by tetrodotoxin. 2. Tetrodotoxin did not affect the release of glutamine under various incubation conditions, no...

After an initial stimulation of human monocyte-derived macrophages with bacterial lipopolysaccharide (LPS), which produces substantial release of tumor necrosis factor-alpha (TNF-alpha), a subsequent exposure to LPS results in about an order-of-magnitude reduction in the levels of TNF-alpha released. We have shown that macrophages which have been stimulated with LPS and then maintained in cultu...

background: during the initial phase of an infection, there is an upregulation of inducible nitric oxide synthase in the macrophages for the production of nitric oxide. this is followed by the recruitment of polymorphonuclear leukocytes (neutrophils) which release arginase. arginase competes with inducible nitric oxide synthase for a common substrate l-arginine. objective: to investigate whethe...

Toxoplasma gondii tachyzoites markedly alter the profile of eicosanoids released by human mononuclear phagocytes. Freshly isolated, 2-h adherent human monocytes release both cyclooxygenase (e.g., thromboxane [TX] B2, prostaglandin [PG] E2) and 5-lipoxygenase (e.g., leukotriene [LT] B4, LTC4) products of arachidonic acid metabolism after stimulation by the calcium ionophore A23187 or ingestion o...