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New Lymphoid Tissue Study Findings Have Been Reported by Researchers at National Institute for Public Health and the Environment (Immunotoxicity of...

July 18, 2014



New Lymphoid Tissue Study Findings Have Been Reported by Researchers at National Institute for Public Health and the Environment (Immunotoxicity of silver nanoparticles in an intravenous 28-day repeated-dose toxicity study in rats)

By a News Reporter-Staff News Editor at Health & Medicine Week -- Researchers detail new data in Lymphoid Tissue. According to news reporting originating from Bilthoven, Netherlands, by NewsRx correspondents, research stated, "Nanosilver is used in a variety of medical and consumer products because of its antibacterial activity. This wide application results in an increased human exposure."

Our news editors obtained a quote from the research from National Institute for Public Health and the Environment, "Knowledge on the systemic toxicity of nanosilver is, however, relatively scarce. In a previous study, the systemic toxicity of 20 nm silver nanoparticles (Ag-NP) was studied in a 28-day repeated-dose toxicity study in rats. Ag-NP were intravenously administered with a maximum dose of 6 mg/kg body weight (bw)/day. Several immune parameters were affected: reduced thymus weight, increased spleen weight and spleen cell number, a strongly reduced NK cell activity, and reduced IFN-gamma production were observed. Prompted by these affected immune parameters, we wished to assess exposure effects on the functional immune system. Therefore, in the present study the T-cell dependent antibody response (TDAR) to keyhole limpet hemocyanin (KLH) was measured in a similar 28-day intravenous repeated-dose toxicity study. In addition, a range of immunological parameters was measured. Data obtained using the benchmark dose (BMD) approach were analyzed by fitting dose-response models to the parameters measured. A reduction in KLH-specific IgG was seen, with a lowest 5% lower confidence bound of the BMD (BMDL) of 0.40 mg/kg bw/day. This suggests that Ag-NP induce suppression of the functional immune system. Other parameters sensitive to Ag-NP exposure were in line with our previous study: a reduced thymus weight with a BMDL of 0.76 mg/kg bw/day, and an increased spleen weight, spleen cell number, and spleen cell subsets, with BMDLs between 0.36 and 1.11 mg/kg bw/day. Because the effects on the spleen are not reflected by increased KLH-specific IgG, they, however, do not suggest immune stimulation. Intravenous Ag-NP administration in a 28-day repeated-dose toxicity study induces suppression of the functional immune system."

According to the news editors, the research concluded: "This finding underscores the importance to study the TDAR to evaluate immunotoxicity and not to rely solely on measuring immune cell subsets."

For more information on this research see: Immunotoxicity of silver nanoparticles in an intravenous 28-day repeated-dose toxicity study in rats. Particle and Fibre Toxicology, 2014;11():1-9. Particle and Fibre Toxicology can be contacted at: Biomed Central Ltd, 236 Grays Inn Rd, Floor 6, London WC1X 8HL, England. (BioMed Central - www.biomedcentral.com/; Particle and Fibre Toxicology - www.particleandfibretoxicology.com)

The news editors report that additional information may be obtained by contacting R.J. Vandebriel, Natl Inst Public Hlth & Environm, Center Hlth Protect, NL-3720 BA Bilthoven, Netherlands. Additional authors for this research include E.C.M. Tonk, L.J. de la Fonteyne-Blankestijn, E.R. Gremmer, H.W. Verharen, L.T. van der Ven, H. van Loveren and W.H. de Jong (see also Lymphoid Tissue).

Keywords for this news article include: Europe, Spleen, Bilthoven, Nanosilver, Netherlands, Nanoparticle, Nanotechnology, Lymphoid Tissue, Emerging Technologies, Hemic and Immune Systems

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Health & Medicine Week


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