Epidemiology shows a clear correlation between chronic infection with the hepatitis B virus (HBV) and development of hepatocellular carcinoma (HCC). The potential role of the transactivating hepatitis B virus X protein (HBx) in transformation by HBV is controversial. Here we report that HBx suppresses transformation of primary rat embryo ®broblasts (REFs). Cooperating oncogenes like c-Ha-ras and c-myc transform REF very eciently but cotransfection with HBx suppressed transformation of REFs down to 5%. Similarly, transfection of HBx together with the cooperating oncogenes Ha-ras and SV40 LTAg or c-Ha-ras and mutant p53 reduced the number of foci to 13%. Comparable results were obtained with HBx in the context of the whole HBV. Suppression of focus formation in REF could be partly relieved by cotransfection of apoptosis inhibitors Bcl-2 or E1B. However, cotransfection of apoptosis inhibitors crmA and p35 did not in¯uence the proapoptotic functions of HBx. Thus, HBx may speci®cally activate the Bcl-2 sensitive pathway leading to apoptosis. Experiments with 13 HBx linker scanning mutants revealed that the domains necessary for HBx dependent transactivation overlap with the domains needed for the apoptotic/growth arrest functions of HBx.

Quantification of hepatitis C virus (HCV) core antigen and RNA in serum samples leads to a highly variable ratio of both. It is not clear whether this is due to the inaccuracy of RNA quantification or whether both are independent parameters in a certain range. We established a real-time reverse transcription (RT)-PCR for HCV RNA that combines very high sensitivity with a large dynamic range and minimal standard deviations. The assay was calibrated with the first international standard, 96/790, and the international genotype panel for HCV from the National Institute of Biological Standardisation and Control. A linear readout was obtained between 200 and 5 ؋ 10 7 IU/ml. The detection limit was 80 IU/ml, the reproducibility was <0.05 log, and the standard error within one run was <0.01. Comparison of the method with the Roche Monitor competitive RT-PCR revealed its high accuracy. The core protein concentration was determined within a range from 1.5 to 400 pg/ml by using the preliminary trak-C assay from Ortho Clinical Diagnostics. Correlating the HCV RNA levels with core antigen concentrations in 197 serum samples from 23 interferon-treated patients, a average ratio of 7,900 IU of HCV RNA per pg of core antigen was estimated, but the variability of this ratio exceeded largely the variability of the two assays, ranging from 50 to 20,000 IU/pg. Theoretically, HCV should contain ca. 43,000 IU of RNA/pg core. In conclusion, the core antigen assay seems to detect, in addition to complete virions, RNA-free core protein structures, which enhances its sensitivity (98% in this group). The variable ratio of RNA and core protein is not mainly due to standard deviations of quantification but could be an additional parameter for treatment follow-up and state of viral replication.The accurate quantification of virus particles in the plasma of persons infected with hepatitis C virus (HCV), the so-called viral load, is essential for decisions on the therapy with interferon and ribavirin and the monitoring of this therapy (1,5,13). For this purpose, several tests for the detection of HCV RNA genomes are commercially available, which lead to sometimes conflicting results for HCV RNA copies per milliliter or international units per milliliter. It appears that some divergences are caused by saturation phenomena in competitive nucleic acid amplification tests (4). Different reactivities of the assays with various HCV genotypes other than genotype 1 may also contribute to the problem (3, 11). With the real-time technology for in situ signal generation during DNA amplification (e.g., using the TaqMan or LightCycler system), saturation phenomena can be overcome.Some efforts have been made to establish real-time protocols for HCV quantification by using the SYBR Green format on LightCycler (17) or the TaqMan technology (8, 10). These published real-time-based techniques are two-step procedures with separate reverse transcription (RT), or they use only the nonspecific SYBR Green for generation of the signal.One aim of our study was to estab...

Crystal structures, chemical (including light elements) and spectral data (optical and Mössbauer spectroscopies) were used to characterize coloured (brown, pink, green) tourmalines from three granitic pegmatites from the Moldanubian nappes (Königsalm, Maigen and Blocherleitengraben; Lower Austria). The tourmalines can be classified as fluor-schorl, schorl, foitite, magnesiofoitite, olenite and ''fluor-elbaite'' with varying Li contents, up to $1.2 wt% Li 2 O. Coexisting minerals are quartz, plagioclase (up to An 7), microcline, garnet (spessartine-almandine), muscovite, biotite (annite), very rare lepidolite, apatite, monazite-(Ce), xenotime-(Y), allanite-(Ce) and zircon. The chemical composition of the Fe 2þ-rich tourmaline samples (up to $1.0 wt% TiO 2) varies from fluorschorl, with a ¼ 15.987(2), c ¼ 7.163(2) Å to X (& 0.63 Na 0.37) Y (Fe 2þ 1.12 Al 1.09 Mg 0.56 Mn 2þ 0.08 Fe 3þ 0.07 Li 0.02 Ti 4þ 0.01 Zn 0.01 & 0.04) Z (Al 5.74 Mg 0.26) (BO 3) 3 [Si 5.96 Al 0.04 O 18 ] V (OH) 3 W [(OH) 0.95 F 0.05 ], strongly dichroic (pink and blue) foitite, with a ¼ 15.9537(2), c ¼ 7.1448(4) Å , to X (& 0.51 Na 0.49) Y (Fe 2þ 0.97 Al 0.93 Mg 0.75 Fe 3þ 0.23 Mn 2þ 0.04 Li 0.01 Ti 4þ 0.01 & 0.06) Z (Al 5.72 Mg 0.28) (BO 3) 3 [Si 5.95 Al 0.05 O 18 ] V (OH) 3 W [(OH) 0.91 O 0.06 F 0.03 ], magnesiofoitite, with a ¼ 15.9476(4), c ¼ 7.1578(4) Å. The chemical composition of the Al-and Lirich and Mn 2þ-bearing (up to $5.7 wt% MnO) samples varies from X (Na 0.84 Ca 0.02 & 0.14) Y (Al 1.35 Li 0.78 Mn 2þ 0.65 Ti 4þ 0.01 & 0.21) Z Al 6 (BO 3) 3 [Si 5.92 Al 0.04 B 0.04 O 18 ] V (OH) 3 W [F 0.81 (OH) 0.19 ], ''fluor-elbaite'' with a ¼ 15.8887(3), c ¼ 7.1202(3) Å , to X (Na 0.76 Ca 0.12 & 0.12) Y (Al 1.52 Li 0.69 Mn 2þ 0.43 Fe 2þ 0.09 & 0.27) Z Al 6 (BO 3) 3 [Si 5.71 B 0.29 O 18 ] V (OH) 3 W [F 0.69 (OH) 0.31 ], B-rich ''fluorelbaite'', with a ¼ 15.8430(3), c ¼ 7.1051(3) Å. A positive correlation between the ,T-O. and ,Z-O. bond lengths in tourmalines where the Z site is only occupied by Al (R 2 ¼ 0.617) is useful to correct the ,Z-O. bond length for the inductive effect of the varying ,T-O. bond length. This is important for producing accurate assignments for the different 6-coordinated sites in tourmaline. On the basis of Sm-Nd (garnet, monazite), U-Th-Pb, and U-Pb ages (monazite), the pegmatites crystallised during the Variscan tectonometamorphic event in the Visean (339 AE 4 Ma Maigen, 332 AE 3 Ma Königsalm). These ages are in the range of the earliest intrusions of the South Bohemian pluton (Rastenberg type durbachites). However, on the basis of the spatial relationship of the pegmatites and the Rastenberg type intrusions, a linkage of the intrusive body and the pegmatites is unlikely. Alternatively, the pegmatites may have evolved as granitic pegmatitic melts during decompression from the surrounding country rocks in the frame of exhumation of the Moldanubian nappes after the peak of the Variscan metamorphism.

In chronically infected patients, hepatitis B virus (HBV) particles reach numbers as large as >10⁹ genome equivalents (GE)/ml of serum. However, expression of infectious HBV particles in cell culture only yields 10⁵–10⁶ GE/ml, which is insufficient for many studies. HBV transcription and possibly replication is dependent on hepatocyte-specific differentiation. Thus, we tested several cell culture parameters that have been reported to enhance the expression of hepatocyte-specific markers, such as growth on different extracellular matrices, different cell culture media, low concentrations of fetal calf serum (FCS) and the addition of dimethyl sulfoxide (DMSO) to the medium. Lower concentrations of FCS, growth on collagen and inclusion of DMSO in the medium only moderately enhanced HBV production in vitro when applied individually. However, combinations of these parameters optimised cell culture conditions and reproducibly increased the release of HBV particles about 100-fold to titres >10⁸ GE/ml of culture medium.

Stable expression of HBx leads to deregulation of apoptosis induced by UV irradiation depending on the cell line used. In an immortalized hepatocyte line HBx acted anti-apoptotic whereas expression in a carcinoma derived hepatocyte line HBx enhanced apoptosis.