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Characterization of a feline T-cell-specific monoclonal antibody reactive with a CD5-like molecule
1992
Ackley, C.D. | Cooper, M.D.
The 43 monoclonal antibody raised against feline T cells was found to react with a single-chain glycoprotein of Mr 72,000 that is present on most thymocytes, 60% of lymph node cells, 20% of splenocytes, and 45% of blood mononuclear cells. All CD4+ and CD8+ T cells were found to express the 43-reactive determinant, as did a small subpopulation of CD4-/CD8-/IgM- lymphocytes in the periphery. The 43-reactive determinant was not detected on B cells, macrophages, or other types of blood cells. The 43 antigen was phosphorylated in resting and activated T cells. Its expression was upregulated by stimulation with phorbol myristate acetate and with phytohemagglutinin. When added to concanavalin A-stimulated T-cell cultures in low concentrations, the 43 antibody was found to augment mitogenesis. The data indicate that this antibody may identify a CD5 homologue on feline T cells.
显示更多 [+] 显示较少 [-]Comparison of the chemiluminescence responses of bovine neutrophils to differently opsonized zymosan particles
1993
Stimulatory effects of 6 zymosan preparations on luminol-dependent chemiluminescence (CL) responses of isolated bovine neutrophils were compared. Unopsonized zymosan particles and zymosan particles opsonized with bovine IgG1, IgG2, fresh serum, or serum from which zymosan-specific antibodies, but not complement, had been removed (C3- serum) induced strong CL responses, with nearly equal maximal peaks in the presence of extracellular Ca2+ and Mg2+, whereas the response to fetal bovine serumopsonized zymosan particles was markedly low. Removal of extracellular divalent cations almost completely blocked the CL reaction triggered by unopsonized, IgG1-opsonized, C3-opsonized, and fetal bovine serum-opsonized zymosan particles. By contrast, no change in the respiratory burst activity induced by serum-opsonized zymosan and only partial reduction in the response to IgG2-opsonized zymosan were seen under these conditions. Further experiments were performed with 4 zymosan preparations on neutrophils isolated from 2 calves with a genetic deficiency of CD11/CD18 membrane antigens. The unopsonized zymosan-induced CL reaction was absent in these cells. A reduced, but clear, response was observed with C3-opsonized zymosan. Unexpectedly, in the absence of extracellular Ca2+ and Mg2+ , serum-opsonized zymosan failed to generate the respiratory burst, whereas response to IgG2-opsonized zymosan was normal in the CDll/CD18-deficient neutrophils. These findings indicate that unopsonized zymosan may act in a divalent cation-dependent manner at the receptor for C3bi in bovine neutrophils, as it has been shown to do in the human system. In addition, it seems that IgG2-Fc receptors capable of signaling the respiratory burst in the absence of extracellular Ca2+ and Mg2+ exist on bovine neutrophils.
显示更多 [+] 显示较少 [-]Heavy Metals Residues in Bivalve Mollusks in Fayoum Province and their Potential Health Hazards
2023
Marwa A.M. Abdelhalim | Hosny A. Abdelrahman | Eslam E. Hamed
Bivalves Mollusks have a potential benefit which include protection from anemia due to its content of iron and vit B12 in addition they pose a threat in promoting the ability to be contaminated by different heavy metals residues as a result of mining, industrial production untreated sewage sludge. Hg, Pb, Cd, As and Cr are the main five toxic heavy metals that induce human poisoning. For evaluation of Hg, Pb, Cd, As and Cr residues in Bivalve Mollusks in Fayoum province and their potential hazards, a total of 64 random samples of Bivalve Mollusks (Callista Florida species) were collected from the fish markets of Fayoum City, (Wadi Elrayan), Egypt The results revealed that the mean residues of Hg, Pb, Cd, As and Cr were 0.75, 0.77, 0.089, 7.285 and 0.011 mg/kg/ww, respectively. All samples examined for Hg and As exceeded the PML while Pb and Cd lied with the PML The collected samples were subjected to soaking in running water for 30 minutes; soaking in 5% acetic acid solution for 30 minutes and boiling with 5% acetic acid solution for 15 minutes .The heights reduction % of heavy metals residual levels were recorded after treatment in boiling 5% acetic acid treatment with the following reduction %; Hg (80%), Pb (67.6%), Cd (77.5%), As (44.35%) and Cr (75.76%). The assessment of Hazard quotient (HQ) and hazard index (HI) value was exceeded 1 which indicates a potential risk to human health and TR was > 1x10-4 which indicates a carcinogenic risk to the local consumers and will face high chronic risk if they consume Bivalve Mollusks on regular basis in their diet.
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