To clarify the morphology of hepatitis C virus (HCV), an indirect immunogold electron microscopic study was carried out on two plasma samples with high HCV RNA titres using polyclonal and monoclonal antibodies specific to the putative HCV envelope protein. Spherical virus-like particles, 55 to 65 nm in diameter with spike-like projections, were found in 1.14 to 1.16 g/ml fractions after sucrose density gradient centrifugation. These particles were found only in HCV-infected blood donors and had morphological features similar to those of flaviviruses. Moreover, these particles specifically reacted with the polyclonal and monoclonal antibodies to the putative HCV envelope protein. This is the first known report in which the morphology of the HCV particle is clearly shown.

Dietary restriction of calories, fat and iron improved NAFLD. Reduced serum ferritin levels appear to reduce oxidative stress in the liver.

Potent inhibition of endogenous gene expression by RNA interference has been achieved by using sequence-specific posttranscriptional gene silencing through the action of small interfering RNA molecules (siRNA). In these reports, the natural function of genes could be deduced through the ensuing loss of function. Based on the extraordinary effectiveness in silencing endogenous genes, we wondered whether siRNA could be applied against viral replication in a hepatitis B virus (HBV) model using HBV-specific siRNA. To test this idea, HepG2 2.2.15, a human hepatoblastoma cell line that constitutively produces infectious HBV particles, was transfected with HBV-specific siRNAs and controls. HBV surface antigen (HBsAg) secretion into culture media was inhibited by 78%, 67%, and 42% with siRNA against the polyadenylation (PA), precore (PreC), and surface (S) regions, respectively, compared with controls as detected by enzyme-linked immunosorbent assay. After exposure to HBVPA siRNA, Northern blot analysis showed that HBV pregenomic RNA levels were decreased by 72%, and levels of HBV RNA containing the polyadenylation signal sequence were suppressed by 86%, as detected by RNase protection assay. Levels of HBV core-associated DNA, a replication intermediate, also decreased by 71%. Immunocytochemistry revealed that 30% to 40% of the cells transfected with HBVPA siRNA were completely negative for detectable HBsAg levels. Controls consisting of treatment with HBV-specific siRNA alone, lipofection reagent alone, or random double-stranded RNA (dsRNA) lipofection complex failed to decrease HBV surface antigen, HBV messenger RNA (mRNA), or core-associated HBV-DNA levels. In conclusion, siRNA inhibits hepatitis B viral replication in a cell culture system. Future studies are needed to explore the specific delivery of siRNA to liver cells in vivo and the applicability of this approach.

8-Isoprostane values are elevated in patients with NAFLD and CH-C as compared to healthy controls. Oxidative stress caused by increased lipid peroxidation is involved in the pathogenesis of NAFLD and CH-C.

We quantified serum hepatitis C virus RNA titers and determined hepatitis C virus subtypes in chronic hepatitis C patients treated with interferon‐β to investigate relationships among serum ALT response, serum hepatitis C virus titer and hepatitis C virus subtype. Of 146 chronic hepatitis C patients who received interferon‐β therapy, 24 patients with sustained serum ALT normalization (complete responders) and 26 patients without serum ALT normalization (nonresponders) were randomly selected. Detection, typing and quantitation of hepatitis C virus were performed by means of the “single‐tube” polymerase chain reaction method. Of the 24 complete responders, 21 (87.5%) became negative for hepatitis C virus RNA, whereas 21 (80.8%) of the 26 nonresponders remained positive. Hepatitis C virus infections with types I, II, III, IV, II + III and III + IV occurred in 0 (0%), 22 (51.2%), 10 (23.3%), 1 (2.3%), 7 (16.5%) and 3 (7.9%) patients, respectively. The mean pretreatment hepatitis C virus RNA titer of complete responders (0.4 ± 2.0 × 104 CID50/ml) was significantly lower than that of nonresponders (3.8 ± 4.5 × 104 CID50/ml) (p < 0.01). Regardless of HCV subtype, patients with more than 104 CID50/ml of HCV did not show serum ALT normalization, whereas complete serum ALT response was seen in most cases with less than 102 CID50/ml HCV. These results show that mixed infections with different hepatitis C virus subtypes appear to be more common than previously reported and that the pretreatment serum level of hepatitis C virus RNA is a more important predictor of outcome of interferon therapy than is virus genotype. (HEPATOLOGY 1993;18:1319–1325.)