Shuzo Otani

Randomised trial of effects of interferon-α on incidence of hepatocellular carcinoma in chronic active hepatitis C with cirrhosis

Patients with chronic active hepatitis C and cirrhosis often develop hepatocellular carcinoma. Interferon (IFN) seems to be effective in some patients but whether it prevents carcinogenesis is unknown. In a prospective randomised controlled trial, we evaluated the effects of IFN-alpha in cirrhotic patients with HCV infection because of their high risk of hepatocellular carcinoma. 90 patients with compensated chronic active hepatitis C with cirrhosis were randomly allocated to receive IFN-alpha (6 MU three times weekly for 12-24 weeks) (45 patients) or symptomatic treatment (45 controls), and were followed up for 2-7 years. In nine controls, alanine aminotransferase (ALT) decreased to less than 80 IU/L but did not stay in the normal range. In 19 patients given IFN-alpha, ALT decreased to less than 80 IU/L (in seven patients, it became and stayed normal; p = 0.011, Wilcoxon rank-sum test). However, the mean change in ALT was not significantly different between the two groups. The mean change in peak alpha-fetoprotein values was smaller in patients given IFN-alpha than in controls (p = 0.021). The mean change in the serum albumin level was higher in the IFN-alpha group (p < 0.001). The histological activity index in the 12 IFN-alpha patients undergoing a second biopsy after therapy was improved (p = 0.031). Hepatitis C viral RNA disappeared in seven (16%) of the 45 IFN-alpha patients (95% CI, 7-29%) and in none of the 45 controls (0-8%; p = 0.018). Hepatocellular carcinoma was detected in two (4%, 1-15%) IFN-alpha patients and 17 (38%, 24-54%) controls (p = 0.002, Wilcoxon signed-rank test). The risk ratio of IFN-alpha treatment versus symptomatic treatment was 0.067 (0.009-0.530; p = 0.010 Coxs proportional hazards). IFN-alpha improved liver function in chronic active hepatitis C with cirrhosis, and its use was associated with a decreased incidence of hepatocellular carcinoma.

Identification of the four species of human malaria parasites by nested PCR that targets variant sequences in the small subunit rRNA gene

Abstract A polymorphic region of the small subunit rRNA gene of the four human malaria parasite species was sequenced to see intraspecies variations. Two new variant sequences were found in P. ovale and P. malariae. Based on these sequences together with those published, we have designed species-specific primers that identify the four species of human malaria parasites by nested PCR following amplification of the polymorphic region with interspecies conserved primers. Our method detected the P. ovale variant which had a sequence undetected by a microtiter plate hybridization (MPH) method and had higher detection level in P. malariae species than MPH.

Hypertension Associated with Endothelin-Secreting Malignant Hemangioendothelioma

Endothelin-1, a potent vasoconstrictor peptide that has recently been isolated from the supernatant of cultured porcine aortic endothelial cells (1), is involved in some vascular disorders (2). Mal...

Growth-Inhibitory Effect of a High Glucose Concentration on Osteoblast-like Cells

Impaired bone formation resulting from a decline of osteoblast activity has been implicated in the pathogenesis of diabetic osteopenia. We examined the effects of high glucose concentration alone, independent of insulin deficiency, on the growth of a human osteoblast-like cell line (MG-63). Sustained exposure to high glucose for 7 days inhibited cell growth in a concentration-dependent manner up to 49.5 mmol/L, as compared with cells cultured with a normal glucose concentration (5.5 mmol/L) or a high mannitol concentration (an iso-osmolar control). Glucose (49.5 mmol/L) attenuated the increment either in DNA content or in [3H]thymidine incorporation induced by insulin-like growth factor I (IGF-I). The IGF-I-induced increase of ornithine decarboxylase (ODC) activity, which plays an important role in cell growth, was also attenuated. The half-life of ODC protein was not shortened by the high glucose culture, but the intracellular content of putrescine (an end product of ODC) was significantly decreased. These changes did not occur in the high mannitol culture, strongly suggesting a specific effect of glucose. In summary, our observations suggest that a high glucose concentration significantly impairs the proliferative response of osteoblastic cells to IGF-I and that the defective cell function caused by sustained exposure to high glucose levels might contribute to impaired bone formation in patients with diabetic osteopenia.

Fibrillar Collagen Specifically Regulates Human Vascular Smooth Muscle Cell Genes Involved in Cellular Responses and the Pericellular Matrix Environment

Abstract— Proliferation and &agr;v&bgr;3 integrin-dependent migration of vascular smooth muscle cells are suppressed on polymerized type I collagen. To identify genes specifically regulated in human smooth muscle cells by polymerized collagen, we used the suppressive subtraction hybridization technique. Compared with smooth muscle cells cultured on monomer collagen, polymerized collagen suppresses the following: (1) a number of other extracellular matrix proteins, including fibronectin, thrombospondin-1, tenascin-C, and cysteine-rich protein 61; (2) actin binding proteins including &agr;-actinin; (3) signaling molecules; (4) protein synthesis-associated proteins; and (5) genes with unknown functions. Some of the identified genes, including cysteine-rich protein 61, show unique kinetics of mRNA regulation by monomer or polymerized collagen distinct from growth factors, suggesting extracellular matrix-specific gene modulation. Moreover, in vivo balloon catheter-mediated injury to the rat carotid artery induces many of the genes that are suppressed by polymerized collagen. Protein levels of thrombospondin-1 and fibronectin are also suppressed by polymerized collagen. Thrombospondin-1-mediated smooth muscle cell migration on vitronectin is significantly inhibited after culture on polymerized collagen for 24 hours, which is associated with decreased &agr;-actinin accumulation at focal adhesions. Thus, polymerized type I collagen dynamically regulates gene expression, pericellular accumulation of extracellular matrix molecules, and the response to a given matrix molecule.

Identification and characterization of testis specific ornithine decarboxylase antizyme (OAZ-t) gene: expression in haploid germ cells and polyamine-induced frameshifting

Polyamines are known to play important roles in the proliferation and differentiation of many types of cells. However, in the testis, where polyamines such as spermidine and spermine exist in high concentrations, their roles still remains to be elucidated.

Detection of Hepatitis C Virus Antibody in the Absence of Viral RNA in Patients with Autoimmune Hepatitis

OBJECTIVE To determine whether laboratory findings showing antibodies to hepatitis C virus (HCV) in patients with autoimmune hepatitis represent false-positive results and to identify possible explanations for true-positive results in these patients. DESIGN Cross-sectional. SETTING University-based hospital. PATIENTS Fifty-two patients with non-A, non-B chronic hepatitis as a control group and 26 patients with classic chronic active autoimmune hepatitis. MEASUREMENTS Comparison of the results of five kinds of assays of HCV antibodies and HCV RNA. MAIN RESULTS Of 52 patients with non-A, non-B chronic hepatitis, HCV antibodies (anti-HCV) were detected in 42 patients (81%; 95% CI, 67% to 90%) by a first-generation enzyme-linked immunosorbent assay (ELISA-I), in 39 patients (75%) by Sp42 ELISA, in 37 patients (71%) by RIA-I, in 49 patients (94%) by ELISA-II, and in 48 patients (92%) by RIBA-II. We found HCV RNA in 47 patients (90%; CI, 79% to 97%). Of the 26 patients with autoimmune hepatitis, anti-HCV were detected in 23 patients (88%; CI, 70% to 98%) by ELISA-I, in 12 (46%) by both RIA-I and Sp42 ELISA, in 20 (77%) by ELISA-II, and in 9 (35%) by RIBA-II. However, HCV RNA was found in only five of these patients (19%; CI, 7% to 39%). None of our patients, including controls, had antibodies to superoxide dismutase. Of the 21 patients who had autoimmune hepatitis that was completely responsive to steroid therapy, 18 had anti-HCV by ELISA-I, but 13 of these patients had negative results by RIBA-II, and only two patients had HCV RNA. Of the five patients who did not respond to steroid treatment, all had anti-HCV by ELISA-I, four had negative results by RIBA-II, and three had HCV RNA. CONCLUSIONS Testing for HCV antibodies in patients with autoimmune hepatitis frequently elicits positive results when the ELISA-I or ELISA-II tests are used. Most of these appear to represent false-positive results because HCV RNA is usually absent from the serum. Such false positivity may result from previous infection with HCV or from cross-reaction of an epitope of HCV. Other patients with apparent autoimmune hepatitis who fail to respond to corticosteroid therapy may actually have chronic hepatitis C (or other non-A, non-B hepatitis) infection.

Promotion of Rat Hepatocarcinogenesis by Dimethylarsinic Acid: Association with Elevated Ornithine Decarboxylase Activity and Formation of 8-Hydroxydeoxyguanosine in the Liver

Arsenicals are epidemiologicaUy significant chemicals in relation to induction of liver cancer in man. In the present study, we investigated the dose‐dependent promotion potential of dimethylarsinic acid (DMAA), a major metabolite of inorganic arsenicals in mammals, in a rat liver carcinogenesis model. In experiment 1, glutathione‐S‐transferase placental form (GST‐P)‐positive foci, putative preneoplas‐tic lesions, were employed as endpoints of a liver medium‐term bioassay for carcinogens (Ito test). Starting 2 weeks after initiation with diethylnitrosamine, male F344 rats were treated with 0, 25, 50 or 100 ppm of DMAA in the drinking water for 6 weeks. All animals underwent two‐thirds partial hepatectomy at week 3 after initiation. Examination of liver sections after termination at 8 weeks revealed dose‐dependent increases in the numbers and areas of GST‐P‐positive foci in DMAA‐treated rats as compared with controls. In experiment 2, ornithine decarboxylase activity, which is a biomarker of cell proliferation, was found to be significantly increased in the livers of rats treated with DMAA. In experiment 3, formation of 8‐hydroxydeoxyguanosine, which is a marker of oxygen radical‐mediated DNA damage, was significantly increased after administration of DMAA. These results indicate that DMAA has the potential to promote rat liver carcinogenesis, possibly via a mechanism involving stimulation of cell proliferation and DNA damage caused by oxygen radicals

Transforming Growth Factor-β and Hepatocyte Growth Factor Produced by Gastric Fibroblasts Stimulate the Invasiveness of Scirrhous Gastric Cancer Cells

Scirrhous gastric carcinoma is characterized by cancer cells that infiltrate rapidly in the stroma with extensive growth of fibroblasts. In the present study, we examined the effect of gastric fibroblasts on the invasiveness of a Scirrhous gastric cancer cell line, OCUM‐2D, using an invasion assay. Gastric fibroblast‐derived conditioned medium (CM) significantly stimulated the invasiveness of OCUM‐2D cells, as did transforming growth factor‐β (TGF‐β) and hepatocyte growth factor (HGF). The stimulating activity of gastric fibroblast‐derived CM was inhibited significantly by anti‐TGF‐β neutralizing antibody or anti‐HGF neutralizing antibody. TGF‐β and HGF were detected in the gastric fibroblast‐derived CM, and TGF‐β receptor and C‐met (HGF receptor) were expressed on OCUM‐2D cells. Thus, TGF‐β and HGF produced by gastric fibroblasts appear to affect the invasiveness of scirrhous gastric cancer cells. TGF‐β was also detected in the conditioned medium derived from OCUM‐2D cells, though HGF was not. TGF‐β appears to affect the invasiveness of OCUM‐2D cells in both paracrine and autocrine fashions.

Farnesol-induced growth inhibition in Saccharomyces cerevisiae by a cell cycle mechanism.

The growth of budding yeast, Saccharomyces cerevisiae, was inhibited in medium containing 25 microM farnesol (FOH). The FOH-treated cells were still viable, and were characterized by a transition from budded to unbudded phase as well as a significant loss of intracellular diacylglycerol (DAG). FOH-induced growth inhibition could be effectively prevented by the coaddition of a membrane-permeable DAG analogue which can activate yeast protein kinase C (PKC). However, yeast cell growth was not initiated upon addition of the PKC activator when the cells had been pretreated with FOH for 20 min. The failure in cell growth recovery was believed to be due to a signalling-mediated cell cycle arrest in FOH-pretreated cells. Differential display analysis demonstrated that the expression of cell cycle genes encoding DNA ligase (CDC9) and histone acetyltransferase (HAT2) was strongly repressed in FOH-treated cells. Repression of the expression of these genes was effectively cancelled when cells were grown in medium supplemented with DAG. The authors propose an interference with a phosphatidylinositol-type signalling which is involved in cell cycle progression as a cause of FOH-induced growth inhibition in yeast cells.