124 research outputs found

    Increased TNF-alpha and sTNFR2 levels are associated with high-grade anal squamous intraepithelial lesions in HIV-positive patients with low CD4 level

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    Compared with HIV-negative individuals, HIV-positive individuals have a higher prevalence of anogenital human papillomavirus (HPV) infection, the causative agent of anogenital cancer. TNF-alpha is a major proinflammatory cytokine. sTNFR2 is the soluble form of one of its receptors and is strongly expressed on stimulated lymphocytes. To further understand the role of TNF-alpha, sTNFR2 and other cytokines in the pathogenesis in HPV-related neoplasia, the profiles of serum cytokines in high-risk patients were analyzed for association with anal lesion status. Patients were categorized into 4 groups based on HIV status (HIV-negative vs. HIV-positive with a CD4+ level < 200/uL) and anal lesion status [no lesion, low-grade anal squamous intraepithelial lesion (LSIL) vs. high-grade squamous intraepithelial lesion (HSIL)] based on high resolution anoscopy-guided biopsy. Following adjustment for multiplicity, HIV-negative men with HSIL had lower levels of sTNFR2 than HIV-positive men with low CD4 level and HSIL (p=0.02). HIV-positive men with HSIL had higher levels of TNF-alpha than HIV-negative men with HSIL (p < 0.001), as well as HIV-positive men with no lesion or LSIL (p=0.03). The levels of other factors, including IL-1beta, IL-2, IL-4, IL-8, IFN-gamma, GM-CSF, sTNFR1 and DR5, were not significantly different between groups. Although the sample size was small, these results suggest that systemic activation of TNF-alpha/sTNFR2 in HIV-positive patients with a low CD4 level may promote the development of HSIL and possibly anal cancer

    Human papillomavirus, high-grade intraepithelial neoplasia and killer immunoglogulin-like receptors: a Western Australian cohort study

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    Background: Human papillomavirus (HPV) is the causative agent in cervical cancer and HPV genotypes 16 and 18 cause the majority of these cancers. Natural killer (NK) cells destroy virally infected and tumour cells via killer immunoglobulin-like receptors (KIR) that recognize decreased MHC class I expression. These NK cells may contribute to clearance of HPV infected and/or dysplastic cells, however since KIR controls NK cell activity, KIR gene variation may determine outcome of infection.Methods: KIR gene frequencies were compared between 147 patients with a history of high-grade cervical intraepithelial neoplasia (CIN) and a control population of 187, to determine if any KIR genes are associated with high-grade CIN. In addition a comparison was also made between cases of high grade CIN derived from 30 patients infected with HPV 16/18 and 29 patients infected with non-16/18 HPV to determine if KIR variation contributes to the disproportional carcinogenesis derived from HPV 16/18 infection.Results: High-grade CIN was weakly associated with the absence of KIR2DL2 and KIR2DS2 (p = 0.046 and 0.049 respectively, OR 0.6; 95% CI 0.4 – 0.9) but this association was lost after correction for multi-gene statistical analysis.No difference in KIR gene frequencies was found between high-grade CIN caused by HPV 16/18 and non-16/18.Conclusion: No strong association between KIR genes, high-grade CIN and HPV genotype was found in the Western Australian population

    Cartilage immunoprivilege depends on donor source and lesion location

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    The ability to repair damaged cartilage is a major goal of musculoskeletal tissue engineering. Allogeneic (same species, different individual) or xenogeneic (different species) sources can provide an attractive source of chondrocytes for cartilage tissue engineering, since autologous (same individual) cells are scarce. Immune rejection of non-autologous hyaline articular cartilage has seldom been considered due to the popular notion of “cartilage immunoprivilege.” The objective of this study was to determine the suitability of allogeneic and xenogeneic engineered neocartilage tissue for cartilage repair. To address this, scaffold-free tissue engineered articular cartilage of syngeneic (same genetic background), allogeneic, and xenogeneic origin were implanted into two different locations of the rabbit knee (n=3 per group/location). Xenogeneic engineered cartilage and control xenogeneic chondral explants provoked profound innate inflammatory and adaptive cellular responses, regardless of transplant location. Cytological quantification of immune cells showed that, while allogeneic neocartilage elicited an immune response in the patella, negligible responses were observed when implanted into the trochlea; instead the responses were comparable to microfracture-treated empty defect controls. Allogeneic neocartilage survived within the trochlea implant site and demonstrated graft integration into the underlying bone. In conclusion, the knee joint cartilage does not represent an immune privileged site, strongly rejecting xenogeneic but not allogeneic chondrocytes in a location-dependent fashion. This difference in location-dependent survival of allogeneic tissue may be associated with proximity to the synovium

    Characterization of global transcription profile of normal and HPV-immortalized keratinocytes and their response to TNF treatment

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    <p>Abstract</p> <p>Background</p> <p>Persistent infection by high risk HPV types (e.g. HPV-16, -18, -31, and -45) is the main risk factor for development of cervical intraepithelial neoplasia and cervical cancer. Tumor necrosis factor (TNF) is a key mediator of epithelial cell inflammatory response and exerts a potent cytostatic effect on normal or HPV16, but not on HPV18 immortalized keratinocytes. Moreover, several cervical carcinoma-derived cell lines are resistant to TNF anti-proliferative effect suggesting that the acquisition of TNF-resistance may constitute an important step in HPV-mediated carcinogenesis. In the present study, we compared the gene expression profiles of normal and HPV16 or 18 immortalized human keratinocytes before and after treatment with TNF for 3 or 60 hours.</p> <p>Methods</p> <p>In this study, we determined the transcriptional changes 3 and 60 hours after TNF treatment of normal, HPV16 and HPV18 immortalized keratinocytes by microarray analysis. The expression pattern of two genes observed by microarray was confirmed by Northern Blot. NF-κB activation was also determined by electrophoretic mobility shift assay (EMSA) using specific oligonucleotides and nuclear protein extracts.</p> <p>Results</p> <p>We observed the differential expression of a common set of genes in two TNF-sensitive cell lines that differs from those modulated in TNF-resistant ones. This information was used to define genes whose differential expression could be associated with the differential response to TNF, such as: <it>KLK7 </it>(<it>kallikrein 7</it>), <it>SOD2 </it>(<it>superoxide dismutase 2</it>), <it>100P </it>(<it>S100 calcium binding protein P</it>), <it>PI3 </it>(<it>protease inhibitor 3, skin-derived</it>), <it>CSTA </it>(<it>cystatin A</it>), <it>RARRES1 </it>(<it>retinoic acid receptor responder 1</it>), and <it>LXN </it>(<it>latexin</it>). The differential expression of the <it>KLK7 </it>and <it>SOD2 </it>transcripts was confirmed by Northern blot. Moreover, we observed that <it>SOD2 </it>expression correlates with the differential NF-κB activation exhibited by TNF-sensitive and TNF-resistant cells.</p> <p>Conclusion</p> <p>This is the first in depth analysis of the differential effect of TNF on normal and HPV16 or HPV18 immortalized keratinocytes. Our findings may be useful for the identification of genes involved in TNF resistance acquisition and candidate genes which deregulated expression may be associated with cervical disease establishment and/or progression.</p

    Hemogeneity and stability assessment of certified reference materials on the example of the liquid density standard

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    Do produkcji certyfikowanych materiałów odniesienia (CRM) stosuje się substancje o dostatecznej jednorodności i stabilności. Ocenę jednorodności i stabilności oraz wyznaczenie charakterystyki metrologicznej wzorca wraz z niepewnością wartości wielkości certyfikowanej prowadzi się zgodnie z zaleceniami Normy PN-EN ISO 17034 oraz Przewodnika PKN-ISO Guide 35. Na przykładzie wybranego materiału odniesienia omówiono postępowanie podczas procesu badania jednorodności i stabilności. Do opracowania wyników wykorzystano analizę istotności statystycznej współczynnika nachylenia zależności liniowej dopasowanej do danych pomiarowych oraz metodę dwuczynnikowej zagnieżdżonej analizy wariancji, którą zastosowano w celu wyznaczenia składowych niepewności, związanych z jednorodnością i stabilnością materiału.A candidate material for the production of certified reference materials (CRM) should be sufficiently homogenous and stable. General requirements and more specific guidance for assessment of homogeneity, stability, characterization and uncertainty evaluation are provided in ISO Standard 17034 and ISO Guide 35. This article provides a detailed case study of homogeneity and stability assessment. Two statistical methods has been selected to analyze experimental data. One of them is linear regression analysis used to test statistical significance of the linear trend. The other method is two-way nested analysis of variance used to estimate a combined uncertainty consisting of the between-unit and within-unit heterogeneity contributions

    Beitraege zur Analytik atmosphaerischer Stickstoff-Sauerstoff-Verbindungen

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    Available from the library of Dortmund Univ. (DE) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
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