37 research outputs found

    Modulation of RANTES expression by HCV core protein in liver derived cell lines

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) infection is associated with high percentage of chronicity which implies the ability of the virus to evade or modulate host cell immune system. Modulation of chemokines, such as RANTES may be part of the virus induced pathogenicity. We examined the effect of core and structural proteins of HCV on RANTES expression in two liver derived cell lines, HepG2 and Chang Liver (CHL).</p> <p>Methods</p> <p>HepG2 and Chang Liver (CHL) cell lines were established and selected for constitutive expression of HCV core and structural genes. Flow cytometry and quantitative RT-PCR analysis were performed to examine the effect of HCV core protein on RANTES expression. Luciferase analysis after RANTES-Luc-promoter transfection of established cell lines was assayed by luminometer measurements (RLU) of RANTES promoter activity. IRF-1 and IRF-7 expression was then examined by immunoblotting analysis.</p> <p>Results</p> <p>Results of flow cytometry and RT-PCR analysis indicated that RANTES is differentially regulated by HCV core protein in the two cell lines examined as its expression was inhibited in HepG2 cells, by a reduction of RANTES promoter activity. Conversely, RANTES protein and mRNA were induced by the core protein in CHL cells, through the induction of the promoter.</p> <p>Since HCV genome modulates IRF-1 and IRF-7 in replicon system and IRF-1, IRF-3 and IRF-7 have been reported to regulate RANTES promoter in various cell systems, analysis of the mechanism underlying RANTES modulation by the core protein revealed that IRF-1 expression was induced in HepG2 cells by the core protein, whereas in CHL cells it was expressed at a very low level that was not influenced by transfection with the core protein construct. This suggested that IRF-1 level may mediate the expression of RANTES in cell lines of liver origin. The effect of the core protein on RANTES promoter was countered by co-transfection with NF90, a double-stranded-RNA binding protein that activates some interferon response genes and acts as a component of cell defense against viral infection.</p> <p>Conclusion</p> <p>HCV core protein have opposite effects on the expression of RANTES in different cell types <it>in vitro</it>, possibly reflecting a similar scenario in different microenvironments <it>in vivo</it>.</p

    Geochronological, stable isotopes and fluid inclusion constraints for a premetamorphic development of the intrusive-hosted Björkdal Au deposit, northern Sweden

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    The Björkdal gold deposit, bound to a quartz vein system which is mainly hosted by a quartz-monzodioritic intrusion, is situated at the easternmost part of the 1.9 Ga Skellefte base metal district in the Fennoscandian shield. Three fluid stages may be distinguished, referred to as a “barren” stage, a main gold stage, and a remobilization stage, respectively. From oxygen and hydrogen isotope evidence, it is argued that fluids of different origins (magmatic and surface waters) penetrated the ore zone at the inferred stages, but regional metamorphic fluids appear essentially only to have redistributed elements. Early quartz veining took place during a pre-metamorphic stage at ca. 1.88 Ga, as evidenced by unradiogenic galena data and an Sm–Nd scheelite errorchron of 1,915 ± 32 Ma (MSWD = 0.25). Temporarily, the main ore-forming stage was closely related to the first barren stage and took place during a major uplift event close to 1.88 Ga. Although other source rocks cannot be totally ruled out, available isotope data (O, S, Sr and Pb) are seemingly consistent with the view that these elements, and by inference other ore elements, were derived from the host intrusion

    Ferrihydrite precipitation in groundwater-fed river systems (Nete and Demer river basins, Belgium): Insights from a combined Fe-Zn-Sr-Nd-Pb-isotope study

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    Two groundwater-fed river systems (Nete and Demer, Belgium) carry red suspended material that settles on the river bed forming red sediments. The local aquifer that feeds these river systems is a glauconite-rich sand, which provides most of the dissolved Fe to the rivers. The solid component of these systems, i.e., the red suspended material and sediments, has a simple mineralogy (predominantly ferrihydrite), but shows a complex geochemistry pointing out the different processes contributing to the river chemistry: (1) the red sediments have higher transition metal (excluding Cu) and detrital element (e.g., Si, Al, K, Rb, etc.) concentrations than the red suspended matter because of their longer residence time in the river and higher contribution of the background (aquifer) component, respectively; (2) the red suspended material and sediments have inherited their rare earth element (REE) patterns from the aquifer; (3) the origin of Sr present in the red suspended matter and red sediments is predominantly marine (i.e., Quaternary calcareous rocks), but a small amount is geogenic (i.e., from detrital rocks); (4) Pb in both solids originates mostly from anthropogenic and geogenic sources; (5) all of the anthropogenic Pb in the red suspended material and sediments is hosted by the ferrihydrite; (6) Nd budget of the red riverine samples is controlled by the geogenic source and shows little anthropogenic component; (7) the significant Fe- and Zn-isotope fractionations are in line with the previous studies. Their fractionation patterns do not correlate, suggesting that the processes controlling the isotope geochemistry of Fe and Zn are different: oxidation/reduction most likely governs the Fe-isotope fractionation, whereas adsorption/desorption or admixing of anthropogenic sources control the isotope fractionation of Zn

    Attitude towards remission induction for elderly patients with acute myeloid leukemia influences survival.

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    Combination chemotherapy may induce remission from acute myeloid leukemia (AML), but validated criteria for treatment of elderly are lacking. The remission intention ( RI) rate for elderly patients, as reported to the Swedish Leukemia Registry, was known to be different when comparing the six health care regions, but the consequences of different management are unknown. The Leukemia Registry, containing 1672 AML patients diagnosed between 1997 and 2001, with 98% coverage and a median follow-up of 4 years, was completed with data from the compulsory cancer and population registries. Among 506 treated and untreated patients aged 70-79 years with AML (non-APL), there was a direct correlation between the RI rate in each health region ( range 36-76%) and the two-year overall survival, with no censored observations (6-21%) ( v 2 for trend = 11.3, P < 0.001; r(2) = 0.86, P < 0.02, nonparametric). A 1-month landmark analysis showed significantly better survival in regions with higher RI rates ( P = 0.003). Differences could not be explained by demographics, and was found in both de novo and secondary leukemias. The 5-year survival of the overall population aged 70-79 years was similar between the regions. Survival of 70-79-year-old AML patients is better in regions where more elderly patients are judged eligible for remission induction
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