Evidence for down-regulation of highly expressed TCR by CD4 and CD45 on non-selected CD4+CD8+ thymocytes

Immature CD4+CD8+ double-positive (DP) thymocytes are positively selected for further development if they express TCR reacting with thymic ligands of low affinity. However, the majority of DP thymocytes express low TCR levels. This low level of TCR may be insufficient to recognize thymic ligands. To understand the basis for the low expression of TCR on DP thymocytes, we determined the density of TCR expression at various stages of their development using TCR transgenic (TCR-Tg) mice. We found that TCR expression was high in the thymocytes that had recently transited into the DP stage but then gradually decreased on DP cells if they were not selected by TCR interaction with MHC molecules. However, such TCR suppression was not observed in positively selected DP cells and in the non-selected DP cells obtained from CD45 deficient mice or from mice receiving anti-CD4 mAb. These findings suggest that the once highly expressed TCR at the DP stage is suppressed by CD45 and/or CD4 on non-selected thymocytes. Furthermore, TCR suppression is prevented by TCR-mediated signals. The maintenance of high TCR levels on positively selected DP thymocytes may facilitate their selection.

Hyponatremia with consciousness disturbance caused by omeprazole administration. A case report and literature review

A 68-year-old man developed severe consciousness disturbance after daily administration of 20 mg omeprazole for four days for the treatment of bleeding gastric ulcer. Systemic investigation revealed severe hyponatremia (111 meq/liter). Consciousness did not become clear until his sodium intake was increased to 480 meq/day, and his serum sodium concentrations reached 130 meq/liter. After the discontinuation of omeprazole, his serum sodium levels returned to the normal range with only minimum supplementation of sodium in the form of dietary sodium chloride intake of 10 g/day. Although the mechanism of hyponatremia induced by omeprazole is not clear, an excessive loss of urinary sodium appears to be more likely than water retention with an increase in fluid intake. The literature was also reviewed.

Detection of hepatitis C virus RNA in hepatocellular carcinoma by in situ hybridization

BACKGROUND

Hepatocellular carcinoma frequently is associated with chronic hepatitis C virus (HCV) infection. The presence of HCV in hepatocellular carcinoma has been detected by reverse-transcription polymerase chain reaction of antigenomic HCV RNA, a tissue-specific replicative form of the virus. Now, however, this method of detecting the presence of HCV has been invalidated by reports of antigenomic RNA in the blood or in peripheral blood mononuclear cells.

METHODS

In situ hybridization of HCV RNA was conducted with digoxigenin-labeled cDNA from the core region on surgical specimens of noncancerous and cancerous areas from 12 patients with chronic hepatitis C with or without cirrhosis associated with hepatocellular carcinoma. Several control experiments were also performed, including RNase digestion before hybridization, hybridization with the use of a negative control, and immunohistochemical staining of HCV-core protein.

RESULTS

The in situ hybridization showed positive signals both in noncancerous and cancerous areas of the liver tissue in eight cases. Positive signals were confined to neoplastic cells and nonneoplastic hepatocytes. There were fewer HCV-positive cells in the cancerous area than in the surrounding noncancerous area.

CONCLUSIONS

In situ detection of HCV presents direct evidence of HCV infection in the neoplastic cells of hepatocellular carcinoma and suggests that neoplastic cells may lose their affinity for HCV in the course of malignant transformation.

Mutations in the core promoter region of hepatitis B virus in patients with chronic hepatitis B

The core promoter region of hepatitis B virus genomes regulates transcription of the precore and pregenomic mRNAs encoding hepatitis B e antigen (HBeAg) and core antigen that contain target epitopes for cytotoxic T lymphocytes. The prevalence and clinical significance of mutations in this region were investigated. DNA was extracted from six asymptomatic carriers positive for HBeAg, eight asymptomatic carriers positive for an anti-HBe antibody, and 24 patients with chronic liver disease. The core promoter and precore regions of hepatitis B virus genomes were amplified by polymerase chain reaction, and predominant sequences were determined by direct sequencing. Mutations were found in none of the HBeAg-positive asymptomatic carriers but in all of the anti-HBe-positive asymptomatic carriers and the patients with chronic liver disease. Especially, A to T mutations at nucleotide 1762 and G to A mutations at nucleotide 1764 were found in five anti-HBe-positive asymptomatic carriers, and 22 patients with chronic liver disease. These two mutation hot spots were located within binding sites of the nuclear factors, and nucleotide 1762 was also involved in the A, T rich sequence that is located 28 base pairs upstream of the precore mRNA initiation site. Serum HBeAg and DNA polymerase levels were significantly lower in patients with these mutations than those without these mutations, and five individuals with these mutations were positive for anti-HBe despite the absence of the precore stop codon mutation. These mutants may be selected by host immune response to HBeAg and/or core antigen.

Molecular cloning and sequence analysis of the chick melanocortin 1-receptor gene

The chick melanocortin 1-receptor gene was isolated. It is found to be an intronless gene encoding a 314 amino acid protein, sharing 64% identity with mammalian counterparts. A cis-element responsible for melanocyte-specific transcription is found in its 5' upstream region. It is probable that the expression of the receptor in melanocytes is closely correlated with that of melanogenesis-related genes.

Non-neuronal release of ATP and inositol 1,4,5-trisphosphate accumulation evoked by P2- and M-receptor stimulation in guinea pig ileal segments

Intracellular signal transduction involved in non-neuronal ATP release evoked by alpha, beta-methylene ATP and bethanechol was evaluated in guinea pig ileal longitudinal muscle segments. alpha, beta-methylene ATP (100 microM) and bethanechol (10 microM) evoked ATP released that reached a peak about 3 min after administration. The evoked release of ATP was markedly inhibited by neomycin and spermine, inhibitors of phospholipase C, but not by treatment with pertussis toxin. In addition, the release of ATP was almost completely suppressed by 1 mM Li+, an inhibitor of inositol monophosphatase. These inhibitors, however, did not affect the contractions of the tissue evoked by these agonists. Forskolin and phorbol 12-myristate 13-acetate, activators of adenylate cyclase and protein kinase C, respectively, failed to enhance the evoked release. The accumulation of inositol 1,4,5-triphosphate [Ins(1,4,5)P3] in the muscle segments were enhanced about 2 min after the administration of alpha, beta-methylene ATP. In the presence of 1 mM Li+, however, the enhancement of Ins(1,4,5)P3 accumulation by the P2 agonist was no longer elicited. These findings suggest that the release of ATP by receptor stimulation may result mainly from the activation of phospholipase C, which is coupled to a pertussis toxin-insensitive G-protein and subsequent accumulation of Ins(1,4,5)P3 in the smooth muscles. However, the discrepancy between the inhibitory effects of Li+ on the release of ATP and the accumulation of Ins(1,4,5)P3 to be clarified in future studies.

Hepatic iron contents and response to interferon-alpha in patients with chronic hepatitis C. Relationship to genotypes of hepatitis C virus

Recent reports have shown that response to interferon treatment is influenced by hepatic iron contents in patients with chronic hepatitis C. In those reports, however, hepatitis C virus (HCV) genotypes and serum HCV-RNA levels were not examined. The aim of the present study was to investigate whether hepatic iron contents influence the response to interferon in patients with chronic hepatitis C and whether HCV genotypes and serum HCV-RNA levels play a role in this relationship. Among 65 patients with chronic hepatitis C, hepatic iron contents were significantly high in patients with a history of excess drinking of alcohol (more than 80 g/day) compared to those without, and significantly low in female patients before menopause. Having excluded these patients, hepatic iron contents were significantly higher in patients with genotype 1b infection than those with genotype 2a and 2b infection. There was no significant correlation between hepatic iron contents and plasma HCV-RNA levels. Among the patients with genotype 1b infection, hepatic iron contents were significantly lower in the responders to interferon than those in the nonresponders (429 +/- 100 vs 875 +/- 110 micrograms/g liver, P < 0.05). From these results, it is concluded that response to interferon is mainly influenced by HCV genotypes, while hepatic iron contents may play an important role in response to interferon in patients with genotype 1b infection.

Improvement of peripheral blood lymphocyte subsets in primary biliary cirrhosis after ursodeoxycholic acid therapy

Immunological abnormalities frequently observed in patients with primary biliary cirrhosis are considered to be related to the pathogenesis of this disease. We performed a prospective trial to evaluate whether immune mechanisms play a role in the effectiveness of ursodeoxycholic acid (UDCA) therapy. Fifteen female patients with primary biliary cirrhosis were followed for 1 year and were then treated with UDCA (600 mg/day) for another year. Laboratory tests, including peripheral blood lymphocyte subsets assessed by dual colour fluorescence analysis using monoclonal antibodies against respective T cell markers, were evaluated at the beginning of the study, at the start of therapy and at the end of therapy. In primary biliary cirrhosis, the proportion of cytotoxic T cells, suppressor inducer T cells and alpha beta-receptor bearing T cells were significantly lower than in healthy controls. No significant changes were observed in the proportions during the year before the therapy. These reductions, however, recovered to normal ranges after 1 year of UDCA therapy. These changes were associated with an improvement in the serum levels of aspartate aminotransferase, alkaline phosphatase, gamma-globulin and IgM. The close correlation between the improvement in the imbalance of lymphocyte subsets after the therapy and the clinical status suggests that an immunological process may play a role in the effectiveness of therapy in primary biliary cirrhosis.

Low prevalence of anti-hepatitis C virus antibodies in female hemodialysis patients without blood transfusion: a multicenter analysis

To investigate whether nosocomial infection with hepatitis C virus (HCV) in chronic hemodialysis patients is related primarily to hemodialysis procedures, a multicenter analysis was carried out on 2,132 chronic hemodialysis patients (male: 1,274, female: 858) from 23 dialysis units using a second-generation anti-HCV antibody assay. The prevalence of anti-HCV antibodies in patients with blood transfusion (29.9%) was significantly higher (P < .0001) than in those without blood transfusion (7.6%). Although the prevalence of anti-HCV antibodies increased with the length of hemodialysis in males without blood transfusion, it did not increase even after long-term hemodialysis (more than 5 years) in females without blood transfusion, who exhibited a rate (1.9%) similar to that of healthy blood donors in Japan. There was a significant correlation between the presence of anti-HCV antibodies and anti-HBs antibody in males without blood transfusion. In anti-HBs antibody-negative male patients without blood transfusion, the prevalence of anti-HCV antibodies was significantly lower compared with anti-HBs antibody-positive male patients without blood transfusion. There was marked difference in the prevalence rate in patients without blood transfusion among dialysis units, and there was no correlation between the prevalence and the mean period of dialysis of each dialysis unit. Although nosocomial infection with HCV appears to be related to the hemodialysis environment, the low prevalence of anti-HCV antibodies in females suggests that dialysis procedures per se may not present the risk of hepatitis C virus infection.

[Channel structure and functioning based on octagonal structure model]

On the basis of the sequence comparison of squid sodium channel SQSCl with those of other channels, we have proposed a tertiary structure model of the sodium channel where the transmembrane segments are octagonally aligned and the four linkers of S5-6 between segments S5 and S6 play a crucial role in the activation gate, voltage sensor and ion selective pore, which can slide, depending on membrane potentials, along inner walls consisting of segments S2 and S4 alternately. The proposed octagonal structure model is contrasted with that of Noda et al (Nature 320 : 188-192, 1986) and with Durrel and Guy (Biophys J 62 : 238-250, 1992). The octagonal structure model can explain the gating of activation and inactivation, the ion selectivity, and as well, the action mechanism of both tetrodotoxin (TTX) and a-scorpion toxin (ScTX), and be applied not only to the sodium channel, but also to the calcium channel, potassium channel, cGMP gated channel and further to the inwardly rectifying K channels. However Yan and Horn have discussed voltage dependent S4 movement in sodium channels from the accessibility of methanethiosulfonate (MTSET) to cystein residue which was substituted for the outermost arginine in IVS4 (Neuron 15 : 213-218, 1995), the neutralization of the arginine was revealed not to influence the activation of the channel. It suggest that the residue in the 3rd position of IVS4 is not a part of the voltage sensor located in the membrane. These result suggest that the change of the accessibility might be caused by the change of the covering of the residue rather than the movement of S4.

Gene expressions of c-met and hepatocyte growth factor in chronic liver disease and hepatocellular carcinoma

BACKGROUND/AIMS

The roles of c-met proto-oncogene and hepatocyte growth factor in human livers have not been shown.

METHODS

Gene expressions of both c-met and hepatocyte growth factor were quantified in livers with chronic active hepatitis and in cirrhotic livers with hepatocellular carcinoma as well as in normal controls, using competitive reverse transcription polymerase chain reaction.

RESULTS

C-met expression was significantly increased in chronic active hepatitis compared with control livers, and c-met expression in chronic active hepatitis correlated with serum alanine aminotransferase levels. Hepatocyte growth factor expression was increased in some patients with chronic active hepatitis compared with controls, and there was a significant correlation between c-met expression and hepatocyte growth factor expression. On the other hand, in hepatocellular carcinoma tissues, c-met expression was increased in some cases, while that in the surrounding non-carcinomatous tissues was similar to normal controls. Hepatocyte growth factor expression was not detected in the hepatocellular carcinoma tissues and was low in the surrounding non-carcinomatous tissues.

CONCLUSIONS

These findings suggest that hepatocyte growth factor may be involved in the regeneration of hepatocytes via paracrine mechanism in chronic active hepatitis, while in regulation of c-met expression in hepatocellular carcinoma tissues may be independent of hepatocyte growth factor stimulation.

Ischemic hepatitis in cirrhosis. clinical features and prognostic implications

To characterize liver dysfunction in patients with cirrhosis after variceal bleeding, we analyzed 50 cirrhotic patients who had bleeding esophageal varices with or without shock. Increases in serum total bilirubin levels by 1.5 times were observed within 24 h in 11 of 12 patients with shock who died > 4 days after hemorrhage but in only one of eight patients with shock who survived (p < 0.01). Increases in serum aspartate aminotransferase and alanine aminotransferase by 2.5 times were observed in six patients in the former group but in none of the latter (p < 0.05). In postmortem livers, hepatocellular degeneration with minimal inflammatory cell infiltration was observed. Ischemic hepatitis is frequently noted in cirrhotic patients with ruptured esophageal varices. Patients with increases in the serum level of total bilirubin and/or aminotransferases within 24 h from onset of hemorrhage should be carefully treated even if hemorrhage is controlled.

Roles of alcohol, hepatitis virus infection, and gender in the development of hepatocellular carcinoma in patients with liver cirrhosis

To assess the interaction of alcohol, hepatitis C virus (HCV), and hepatitis B virus (HBV) infection in hepatocarcinogenesis, we prospectively observed 449 patients with liver cirrhosis (LC) who presented to our outpatient clinics in 1 month; 164 patients with habitual drinking [alcoholic liver-liver cirrhosis (AL-LC)] who had taken > 72 g alcohol/day (HCV-positive 81 cases: HCV + AL; HCV-negative 83 cases: AL); 176 patients with HCV infection, but without alcohol intake: 34 patients with HBV infection: 6 patients with HCV and HBV coinfection; and 82 patients with liver diseases from other etiologies, such as primary biliary cirrhosis. In the HCV group, the cumulative occurrence rate of hepatocellular carcinoma (HCC) was 9%, 18%, and 23% in the first, second, and third years, respectively. In the HCV + AL group, that was 13%, 17%, and 28%, respectively. There was no difference in the HCC occurrence rate between the two groups. In the AL group, the cumulative HCC occurrence rate was only 1% during the observation period of 3 years. The occurrence rate was significantly lower in the AL group, compared with the HCV and the HCV + AL groups. In the HBV group, the cumulative occurrence rate of HCC during the observation period of 3 years was 17%, which was similar to that of the HBV + AL group, 14%. We also examined some other variables that might be related to the development of HCC. The cumulative occurrence rate of HCC in male patients was 31%, whereas that was 18% in female patients. In the HCV group, there was a significant increase of HCC occurrence rate in male patients. In contrast, no difference was observed in the HCC occurrence rate between male and female patients in the HBV group. The present study suggests that alcohol alone may not be an independent risk factor for HCC, nor does it accelerate HCC development in LC patients with HCV and HBV infection during the prospective observation of 3 years.

Complete nucleotide sequences of hepatitis B virus genomes associated with epidemic fulminant hepatitis

Pre-core/core mutants are frequently observed in patients with fulminant hepatitis. To investigate the extent of molecular characteristics of hepatitis B virus (HBV) genomes implicated in the development of fulminant hepatitis, full-length HBV genomes were sequenced directly from sera of two patients with epidemic fatal fulminant hepatitis, after amplification by the polymerase chain reaction. These two genomes, of 3215 nucleotides, were 99.6% identical, indicating that a common source of HBV potentially caused fulminant hepatitis. Thirty unique nucleotide mutations were commonly found in the two entire HBV genomes. Three were located in the stem-loop structure, changing this element to a more stable structure. Twenty-five unique amino acid substitutions were found in each open reading frame, except for the X and pre-surface 2 genes. One was located in the pre-surface 1 gene; two were in the surface gene; three were in the pre-core gene, including codons 28 (tryptophan to stop codon) and 29 (glycine to aspartic acid); eight were in the core gene; and 11 were in the polymerase gene. The pre-core mutations at codons 28 and 29 were common to the two HBV strains reported previously in patients with epidemic fulminant hepatitis. Thus, HBV genomes associated with epidemic fatal fulminant hepatitis have numerous unique mutations, located mainly in the polymerase gene, as well as the pre-core/core gene, including mutations in the stem-loop structure of the pregenome encapsidation signal sequence. These mutations may be associated with the development of fulminant hepatitis.

Distribution of hepatitis C virus RNA in the liver and its relation to histopathological changes

To investigate a cellular mode of HCV-infection in the liver and its pathological implications in relation to histopathological changes or clinical data, we studied the distribution of HCV-RNA in the livers of 21 patients with HCV-related chronic liver disease (chronic active hepatitis, 14 cases; cirrhosis, 7 cases) using the in situ hybridization technique. In situ hybridization was performed on 4% paraformaldehyde-fixed frozen sections with digoxigenin-labeled DNA probe deduced from the core region of HC-J4. In situ hybridization showed positive signals in the liver specimens of 20/21 cases. The signals were localized in the cytoplasm of hepatocytes. The distribution pattern of positive cells was individually different, whereas the pattern was identical in the right and left lobes. There were no correlations of the HCV-positive cell number with serum aminotransferase levels at biopsy or with genotypes of HCV. The positive hepatocytes were occasionally associated with infiltrating mononuclear cells, and they were sparsely distributed in the area of piecemeal necrosis. These findings suggest that factors such as host immunoreaction to the virus may be more important than its direct cytopathy in the pathogenesis of chronic hepatitis C virus infection.

Mutations in the nonstructural protein 5A gene and response to interferon in patients with chronic hepatitis C virus 1b infection

BACKGROUND

A region associated with sensitivity to interferon has been identified in the nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) genotype 1b. The region spans amino acid residues 2209 to 2248 (NS5A2209-2248) of HCV-J, a strain of HCV-1b whose complete genomic sequence has been identified. We examined whether the NS5A2209-2248 sequence present before therapy could be used as a predictor of the response to interferon therapy in patients with chronic HCV-1b infection.

METHODS

We retrospectively analyzed 84 patients with chronic HCV-1b infection who had received interferon alfa (total dose, 516 million to 880 million units) for six months. Pretreatment serum samples were analyzed. The amino acid sequence of NS5A2209-2248 was determined by direct sequencing of the HCV genome amplified by the polymerase chain reaction (PCR) and was compared with the established sequence for HCV-J.

RESULTS

A complete response, as evidenced by the absence of HCV RNA in serum on nested reverse-transcription PCR for six months after therapy, did not occur in any of the 30 patients whose NS5A2209-2248 sequences were identical to that of HCV-J (wild type). Five of 38 patients (13 percent) with 1 to 3 changes in NS5A2209-2248 (intermediate type) had complete responses, as did all 16 patients with 4 to 11 amino acid substitutions (mutant type), indicating that the mutant type was significantly associated with a complete response (P < 0.001). Although baseline serum HCV RNA levels, as measured by a branched-chain DNA assay, were lower in patients with the mutant type of NS5A2209-2248 than in those with the other types (P < 0.001), multivariate analyses revealed that the number of amino acid substitutions in NS5A2209-2248 was the only variable associated with an independent effect on the outcome of interferon therapy (odds ratio, 5.3; 95 percent confidence interval, 1.6 to 18; P = 0.007).

CONCLUSIONS

In patients with chronic HCV-1b infection, there is a substantial correlation between responses to interferon and mutations in the NS5A gene.

Characteristics of anti-HCV antibody-positive patients with hepatocellular carcinoma on chronic hemodialysis: recommendation of periodic ultrasonography for early detection

We analyzed 10 patients (male:female 9:1, mean age 64.2 years) who developed hepatocellular carcinoma during the observation period of 2 years among 2,164 chronic hemodialysis patients in 23 dialysis centers. Among them, 409 patients were positive for serum anti-HCV antibodies (19%). They were all positive for serum anti-HCV antibodies but negative for HBs antigen. None of the anti-HCV antibody-negative patients developed hepatocellular carcinoma during this period. Although liver function tests of the patients were almost normal, pathological examination of the liver revealed chronic active hepatitis or cirrhosis. Periodic ultrasonographic examination is necessary for early detection of hepatocellular carcinoma in chronic hemodialysis patients with positive anti-HCV antibodies even if liver function tests are within normal ranges.

Effects of additional administration of colchicine in ursodeoxycholic acid-treated patients with primary biliary cirrhosis: a prospective randomized study

BACKGROUND/AIMS

Although ursodeoxycholic acid is effective for the treatment of primary biliary cirrhosis, some patients do not respond to this treatment. The objective of the present study was to investigate the effects of additional administration of colchicine in ursodeoxycholic acid-treated patients with primary biliary cirrhosis.

METHODS

Twenty-two patients with primary biliary cirrhosis treated with ursodeoxycholic acid (600 mg/day) for 30 months were randomly assigned to two groups: group 1, colchicine (1 mg/day) and ursodeoxycholic acid (n = 10); group 2, ursodeoxycholic acid alone (n = 12).

RESULTS

In group 1, there were significant decreases in mean serum levels of alkaline phosphatase, total bilirubin, gamma-glutamyltranspeptidase, alanine aminotransferase, aspartate aminotransferase, and IgM, and these changes were more remarkable in those who responded poorly to ursodeoxycholic acid. In contrast, there were no significant changes in those values in group 2.

CONCLUSIONS

Additional administration of colchicine to ursodeoxycholic acid may be beneficial for patients with primary biliary cirrhosis, especially those who respond poorly to ursodeoxycholic acid. It is necessary, however, to further confirm the efficacy of colchicine by examining histological changes and following the patients for longer periods.

Aeromonas sobria infection with severe muscle degeneration in a patient with alcoholic liver cirrhosis

A 56-yr-old male who had been followed for alcoholic liver disease was admitted for abdominal pain and a high fever. Gastrointestinal endoscopy revealed bleeding esophageal varices that were treated by endoscopic sclerotherapy. Blood culture on admission was positive for Aeromonas sobria. Then skin bullas and ulcers and severe muscle degeneration developed. The patient died despite extensive treatment with antibiotics. A. sobria infection in patients with liver cirrhosis is rare.

Host dependent variation of hepatitis C virus: phylogenetic analyses

Hepatitis C virus quasispecies in six patients from three families were separated by single strand conformation polymorphism analysis and by determination of nucleotide sequences of envelope regions containing the E1 gene segment and hypervariable region-1 of each quasispecies. Four of the six patients had multiple quasispecies. Phylogenetic analyses indicated that all quasispecies from one individual were highly homologous to each other. The homology was higher in the E1 gene segment than in hypervariable region-1. Furthermore, all quasispecies found in members of one family (husband and wife) were also highly homologous, suggesting direct intrafamilial transmission. The direction of hepatitis C virus variation in hypervariable region-1, however, seems to differ depending on the host in intrafamilial transmission.

Detection of hepatitis C virus RNA in hepatocellular carcinoma by in situ hybridization

BACKGROUND

Hepatocellular carcinoma frequently is associated with chronic hepatitis C virus (HCV) infection. The presence of HCV in hepatocellular carcinoma has been detected by reverse-transcription polymerase chain reaction of antigenomic HCV RNA, a tissue-specific replicative form of the virus. Now, however, this method of detecting the presence of HCV has been invalidated by reports of antigenomic RNA in the blood or in peripheral blood mononuclear cells.

METHODS

In situ hybridization of HCV RNA was conducted with digoxigenin-labeled cDNA from the core region on surgical specimens of noncancerous and cancerous areas from 12 patients with chronic hepatitis C with or without cirrhosis associated with hepatocellular carcinoma. Several control experiments were also performed, including RNase digestion before hybridization, hybridization with the use of a negative control, and immunohistochemical staining of HCV-core protein.

RESULTS

The in situ hybridization showed positive signals both in noncancerous and cancerous areas of the liver tissue in eight cases. Positive signals were confined to neoplastic cells and nonneoplastic hepatocytes. There were fewer HCV-positive cells in the cancerous area than in the surrounding noncancerous area.

CONCLUSIONS

In situ detection of HCV presents direct evidence of HCV infection in the neoplastic cells of hepatocellular carcinoma and suggests that neoplastic cells may lose their affinity for HCV in the course of malignant transformation.