Koji Manabe

Risk factors for hepatocellular carcinoma in Hepatitis C patients with sustained virologic response to interferon therapy

Abstract: Background: Although a variety of papers demonstrated inhibited hepatocarcinogenesis with interferon (IFN) therapy for chronic hepatitis C, a small number of hepatocellular carcinomas (HCCs) were still observed even in sustained virologic responders.

Distribution of collagen type IV α1–6 chains in human normal colorectum and colorectal cancer demonstrated by immunofluorescence staining using chain‐specific epitope‐defined monoclonal antibodies

Background and Aim: Loss of basement membrane (BM) components, such as type IV collagen, has been demonstrated in colorectal cancer, but the fine diversity of the assembly of α (IV) chains, the composition of type IV collagen, and alterations in the collagen have not been fully analyzed. Here, we defined immunohistochemically the expression of α1–6 (IV) chains in colorectal cancer tissues and adjacent normal mucosa by the use of chain‐specific monoclonal antibodies.

Cellular immune response in liver of patients with chronic hepatitis B —Electron microscopic observation of lymphocyte subsets by the immunoperoxidase method using monoclonal antibodies

SummaryThe morphological association between lymphocytes and hepatocytes was studied at the light and electron microscopic levels by the peroxidase-labeled antibody method using mouse monoclonal antibodies against Leu-1, Leu-2a, Leu-3a, Leu-7 and Leu-10 antigens in liver biopsy specimens from patients with chronic hepatitis B. Leu-1 + cells (T cells), especially Leu-2a + cells (cytotoxic/suppressor T cells), infiltrated mostly in periportal areas with piecemeal necrosis and in parenchymal areas with focal necrosis. By double staining techniques, Leu-2a + cells were often seen in contact with hepatocytes containing membranous hepatitis B surface and/or core antigens in patients with chronic active hepatitis. At the ultrastructural level, Leu-2a + cells frequently occupied the sinusoid and also migrated into both the space of Disse and between hepatocytes. Furthermore, they often showed intimate surface-contact with hepatocytes having hepatitis B surface and/or core antigens, and, occasionally, injured hepatocytes were surrounded by several Leu-2a + cells. In contrast, Leu-3a + cells, Leu-7 + cells and Leu-10 + cells sometimes appeared in the sinusoid, but seldom in the space of Disse and between hepatocytes. These findings suggest that cytotoxic T lymphocytes may be associated with the necrosis of hepatocytes in chronic hepatitis B.

Association of Fatty Liver with Increased Ratio of Visceral to Subcutaneous Adipose Tissue in Obese Men

We studied the association of fatty liver with subcutaneous and visceral obesity in 46 male and 36 female patients with body mass index (BMI) over 22 kg/m2. The correlation coefficient between the ratio of the visceral adipose tissue to the subcutaneous adipose tissue (V/S) and the computed tomography (CT) number of the liver was -0.299 (P < 0.05) and that between the V/S ratio and the ratio of the CT number of the liver to that of the spleen (CT-L/CT-S) was -0.335 (P < 0.05) in the males. Partial correlation analysis after making correction for BMI showed an increased correlation coefficient of -0.485 (P < 0.05) between the V/S ratio and the CT-L/CT-S ratio in the males. The odds ratio in the males for CT-L/CT-S below 1.0 and V/S above 1.0 was 3.25 with a 95% confidence interval of 1.02 to 9.39. No such association between the V/S ratio and the CT-L/CT-S ratio was present in the female patients. Multiple regression analysis with serum level of alanine aminotransferase, a marker of fatty liver, as an independent variable revealed a partial regression coefficient of -17.7 for CT-L/CT-S (P < 0.05) in the males and -21.7 (P < 0.05) in the females, validating the CT-L/CT-S ratio as an index of fatty liver. The results indicate the association of fatty liver as determined by the CT-L/CT-S ratio with visceral obesity in males.

Functional coupling of chloride–proton exchanger ClC-5 to gastric H+,K+-ATPase

Summary It has been reported that chloride–proton exchanger ClC-5 and vacuolar-type H+-ATPase are essential for endosomal acidification in the renal proximal cells. Here, we found that ClC-5 is expressed in the gastric parietal cells which secrete actively hydrochloric acid at the luminal region of the gland, and that it is partially localized in the intracellular tubulovesicles in which gastric H+,K+-ATPase is abundantly expressed. ClC-5 was co-immunoprecipitated with H+,K+-ATPase in the lysate of tubulovesicles. The ATP-dependent uptake of 36Cl− into the vesicles was abolished by 2-methyl-8-(phenylmethoxy)imidazo[1,2-a]pyridine-3-acetonitrile (SCH28080), an inhibitor of H+,K+-ATPase, suggesting functional expression of ClC-5. In the tetracycline-regulated expression system of ClC-5 in the HEK293 cells stably expressing gastric H+,K+-ATPase, ClC-5 was co-immunoprecipitated with H+,K+-ATPase, but not with endogenous Na+,K+-ATPase. The SCH28080-sensitive 36Cl− transporting activity was observed in the ClC-5-expressing cells, but not in the ClC-5-non-expressing cells. The mutant (E211A-ClC-5), which has no H+ transport activity, did not show the SCH28080-sensitive 36Cl− transport. On the other hand, both ClC-5 and its mutant (E211A) significantly increased the activity of H+,K+-ATPase. Our results suggest that ClC-5 and H+,K+-ATPase are functionally associated and that they may contribute to gastric acid secretion.

Immunohistochemical study of HLA class 1 antigens on the hepatocytes of patients with chronic hepatitis B

SummaryIn order to evaluate the role of histocompatibility antigen (HLA) class 1 antigens in the pathogenesis of liver cell necrosis, HLA class 1 antigens on hepatocytes were studied in the liver biopsy materials from 20 patients with chronic hepatitis B by the peroxidaselabeled antibody method using a monoclonal antibody to human HLAA, B, C (Cappel Laboratories). Both increased expression of HLA class 1 antigens on the hepatocytes and decreased distribution of intrahepatic hepatitis B core antigen (HBcAg) were observed in patients with an exacerbation of the inflammatory activity. These findings suggest that expression of HLA class 1 antigens on the hepatocytes may be increased when an exacerbation of inflammatory activity develops, and may be compatible with the concept that expression of these antigens plays and important role for the lysis of hepatitis B virus (HBV)-infected liver cells by cytotoxic T cells. Furthermore, in seven patients, expression of HLA class 1 antigens was studied in the liver before and after treatment with human lymphoblast interferon (IFN)-α, recombinant IFN-α or IFN-Β. Increased expression of HLA class 1 antigens was observed in patients with decreased intrahepatic HBcAg and DNAP in sera after IFN treatment. These results also suggest that the increase of HLA class 1 antigens by IFN may be related to the immune mechanism for the effective elimination of HBV.

High Level of Expression of α-Fetoprotein Receptor in Gastric Cancers

The expression of the receptor for α-fetoprotein (AFP-R) was examined immunohistochemically in 47 cancer and 14 benign human gastric tissues. Rabbit polyclonal antibody against human AFP-R was used for immunohistochemical staining. Thirty-four of the 47 cancer tissues expressed AFP-R showing granular or reticular staining on the cancer cell surface, while only 2 of 61 control cases (14 benign gastric tissues and 47 nonmalignant tissues adjacent to cancer) showed faint and homogeneous staining in the cytoplasm of noncancerous cells. There was a significant difference in staining intensity between the cancerous and noncancerous groups. However, no statistically significant difference in staining intensity was found among the groups of well-differentiated, moderately differentiated and poorly differentiated adenocarcinomas. On the other hand, the staining intensity of signet ring cell carcinoma was significantly weaker than that of the three adenocarcinoma groups. The high level of AFP-R expression in gastric cancers may allow the use of AFP-R as a new clinically useful marker of gastric cancer in the tissue level.

Effects of adenine arabinoside on cellular immune responses in patients with chronic hepatitis B.

SummaryThe lymphocyte subsets in the peripheral blood and in liver biopsies from 4 patients with chronic hepatitis B obtained about 2–7 weeks before and after treatment with adenine arabinoside (Ara-A) were studied by a peroxidase-labeled antibody method using monoclonal antibodies against Leu-1, Leu-2a, Leu-3a, Leu-7 and Leu-10 antigens. In the peripheral blood, the percentage of Leu-2a + (cytotoxic/suppressor) cells was significantly reduced and the ratio of Leu-3a + (helper/inducer) to Leu-2a + cells was increased after the treatment with Ara-A. In the liver biopsies, the numbers of Leu-1 + (pan T) and Leu-2a + cells were significantly decreased after the treatment with Ara-A. As a result, the Leu-3a + /Leu-2a + ratio was significantly elevated in the liver after the therapy. The majority of lymphocytes distributed at sites of hepatocytic necrosis were positive for Leu-2a. The reduced numbers of Leu-1 + and Leu-2a + cells after the treatment were mainly due to the decrease of these cells infiltrating to the sites of hepatocytic necrosis. The numbers of other subsets (Leu-3a +, Leu-7 + and Leu-10 +) changed without any specific tendency both in the peripheral blood and in the liver biopsies after the treatment. With respect to viral replication, most of the patients showed a decrease of serum DNA polymerase activity or demonstrable intrahepatic HBsAg and HBcAg after the treatment. These data suggest that T cell-mediated cytotoxicity against HBV-infected hepatocytes is diminished after treatment with Ara-A.