Indirect serum biomarkers perform sub optimally in screening for significant liver fibrosis among HIV-infected and uninfected adults in Uganda

ntroduction: Indirect serum biomarkers present an acceptable noninvasive and cheap alternative for screening of significant liver fibrosis (SLF). Evaluation of their use in resource limited settings is important to determine their utility. Methods: We conducted a cross sectional study among 520 HIV infected and HIV uninfected adults attending care clinics in Kampala Uganda. Presence of SLF was determined using Fibroscan® liver stiffness measurement of ≥7.2KPa. The diagnostic value of indirect serum biomarkers for diagnosis of SLF was evaluated using the area under the receiver operating characteristics curve (AUROC) using Fibroscan® as gold standard. Results: Overall AUROC values for Age Platelet Index (API), Aspartate to Alanine Ratio (AAR), AST-to-Platelet Ratio Index (APRI), Fibrosis Index based on 4 Factors (FIB-4) and Gamma glutamyl transferase to Platelet Ratio Index (GPR) were 0.52, 0.49, 0.55, 0.55 and 0.54 respectively. Among HIV-infected participants AUROC values were slightly improved at predicting presence of SLF but still under 70%. Conclusion: Despite APRI and FIB-4 being more likely to identify participants with SLF, the overall diagnostic value of all serum biomarkers was poor with and without stratification by HIV status. We recommend the use of Fibroscan® technology as more accurate non-invasive diagnostic method for screening of SLF

Biomarkers in rats for kidney damage characteristics of arsenism due to coal burning and benchmark dose analysis / 中国药理学与毒理学杂志

OBJECTIVE Study the kidney toxic effects caused by burning coal endemic arsenism in rats,application bench mark dose (BMD) method to investigate the bench mark dose of urinary arsenic (UAs)and the changes in bio markers of renal function.METHODS Wistar rats were fed for 90 d with arsenic 0,25,50,100 mg·kg -1 conta minated feed.Urinary arsenic,kidney arsenic and renal function indicators were determined,and routine pathological and fibrosis of kidney were exa mined.UAs as the exposure bio marker,Uβ2-MG,UNAG and UALB for the effect bio markers,application bench mark dose method to calculate the BMD and BMDL of UAs for each effect bio markers.RESULTS UAs,KAs, Uβ2-MG,UNAG,UALB levels of rats in arsenic 100 mg·kg -1 group were increased than normal group (P <0.05);In light microscope,the results of HE staining of rat kidney in all arsenic dose groups showed infla mmatory cell infiltration,renal tubular epithelial cell swelling,renal interstitial capillary dila-tion,congestion and other varying degrees pathological changes,and the results of masson staining showed varying degrees of tubulointerstitial fibrosis;UAs as the exposure bio marker,Uβ2-MG,UNAG, UALB for the effects of mark,the BMD and BMDL of UAs for Uβ2-MG,UNAG,UALB were calculated, the BMD values were 998.9,1213.5,1386.9 μg·g -1 Cr,the BMDL values were 660.5,803.6 and 909. 4 μg·g -1 Cr,respectively.CONCLUSION Burning coal arsenic pollution can cause kidney da mage in rats,mini mal change nephropathy may be the pri mary pathological in the coal arsenic conta mination of kidney da mage.The BMD and BMDL of UAs were 998.9,660.5 μg·g -1 Cr,the early changes of renal function of burning coal arsenism in rats;it is reco mmended to use the more sensitive bio markers Uβ2-MG to calculate the biological exposure li mits on renal injury caused by arsenic.

Carcinogenesis of Murine Astrocytes in Culture

Astrocytes play important roles in normal brain development and the physiological processes. In particular, 30% of the brain volume consists of astrocytes, and they are the primary target cell in the brain for cellular injuries from chemical exposures. The present study attempts to establish an immortalized murine astrocyte cell line to study the mechanisms of chemical-induced carcinogenesis of astrocytes. Primary astrocytes isolated from mice were transfected with plasmid carrying the SV40 T antigen. Clonal cells obtained after G418 selection were continuously subcultured to establish an immortalized astrocyte cell line. The cell line was positive on GFAP expression and was sensitive to exposure to such chemicals as MNNG. Cells were treated with MNNG for 5 days, with doses ranging from 0.001ug/ml to 1ug/ml. Dose-dependent cellular transformations of astrocytes were observed. Treatments at 0.01ug/ml showed the most distinct characteristics of neoplastic transformation. Subsequent treatment with TPA produced higher levels of neoplastic cell transformation than MNNG treatment alone, as evidenced by increases of saturation density, soft-agar colony formation and cell aggregation. Promotional effects of TPA on cell transformation was further demonstrated by the shortening duration of foci appearance. Addition of hydrocortisone to the culture media resulted in further promotion of cell transformation in astrocytes treated with MNNG and TPA, suggesting that glucocortocoid also plays a role in the promotion of chemical-induced astrocyte transformation. The present study demonstrates that astrocytes are susceptible to chemical-induced carcinogenicity and subject to mechanisms of multistage carcinogenesis. Analysis of MNNG-transformed astrocytes showed that, while the expression of TGF-beta was decreased, expression of GFAP, IL-1betaand fibronectin were increased. The results suggest that these factors are associated with mechanisms of MNNG-induced astrocyte transformation and may be used as potential candidates for biomarkers representing astrocyte-related tumors and cell toxicities. The study showed scientific evidence that growth factors, cytokine and the extracellular matrix are involved in processes of chemical-induced transformation of astrocytes. In addition, the present work provided an excellent opportunity to develop an immortalized astrocyte cell line that can be used for studying mechanisms of astrocyte-related diseases.