Kupffer cell function during the erythocytic stage of malaria.

Background And Aim: Previous studies using isolated perfused rat liver in vivo have suggested that during the erythrocytic phase of malaria infection, overall phagocytosis by Kupffer cells is enhanced. The aim of the present study was to further investigate the individual phagocytic capacity and prostaglandin E(2) (PGE(2)) secretion of isolated Kupffer cells in vitro, and the immunohistochemical characteristics of Kupffer cells in vivo.

Methods: Malaria was induced in male Sprague-Dawley rats (n = 12) by inoculation with parasitized red cells containing Plasmodium berghei.

Recombinant human zona pellucida proteins ZP1, ZP2 and ZP3 co-expressed in a human cell line.

Aim: To produce biologically active recombinant human (rh) ZP proteins in a human cell for use in sperm function tests.

Methods: The human embryonic kidney cell line 293T was employed to produce rhZP1, rhZP2 and rhZP3 proteins individually and together by co-expression. Presence of these proteins in the culture medium and cell lysate was assessed by Western blotting analysis.

Elevated SNAP-25 is associated with fatty acid-induced impairment of mouse islet function.

The role of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in insulin secretion following chronic exposure to non-esterified fatty acids (NEFAs) has not been extensively investigated. Here, we show that synaptosome-associated protein of 25 kDa (SNAP-25) levels were predominantly elevated in the soluble fraction of mouse islets exposed to palmitate. This coincided with an impairment of insulin secretion to glucose and non-glucose secretagogues, consistent with a defect at a distal regulatory step in exocytosis.

Matrix protein glycation impairs agonist-induced intracellular Ca2+ signaling in endothelial cells.

Studies have shown diabetes to be associated with alterations in composition of extracellular matrix and that such proteins modulate signal transduction. The present studies examined if non-enzymatic glycation of fibronectin or a mixed matrix preparation (EHS) alters endothelial cell Ca(2+) signaling following agonist stimulation. Endothelial cells were cultured from bovine aorta and rat heart.

Prevention of diabetes-induced albuminuria in transgenic rats overexpressing human aldose reductase.

Studies using pharmacologic inhibitors have implicated the enzyme aldose reductase in the pathogenesis of albuminuria and diabetic renal disease. However, a clear conclusion is not easily drawn from such studies since these pharmacologic inhibitors have nonspecific properties. To examine further the role of aldose reductase, we have overexpressed the human enzyme in a transgenic rat model.

Phorbol myristate acetate induces ruffling of the acrosome of human sperm.

Objective: To determine the effect of phorbol myristate acetate (PMA) on human acrosome morphology and the acrosome reaction.

Design: Controlled experiments on sperm and unfertilized oocytes from volunteers.

Setting: Academic research and teaching tertiary hospital.

Comparison of insulin secretory function in two mouse models with different susceptibility to beta-cell failure.

Type 2 diabetes is characterized by a susceptibility to beta-cell failure. However, subjects at risk of developing type 2 diabetes, such as those with obesity or a family history of diabetes, have been shown to display hyperinsulinemia. Although this hyperinsulinemia may be an adaptive response to insulin resistance, the possibility that insulin hypersecretion may be a primary defect has not been thoroughly investigated.

Hyaluronan increases glomerular cyclooxygenase-2 protein expression in a p38 MAP-kinase-dependent process.

Background: Accumulation of the matrix glycosaminoglycan hyaluronan occurs in many types of renal injury but could follow any provision of hyaluronan substrate to the kidney, for example, through widespread use of supplementary glucosamine in osteoarthritic conditions. Hyaluronan can increase cyclooxygenase-2 (COX-2) protein and prostaglandin production. This effect was characterized in rat renal glomeruli to determine the cellular mechanism of activation.