Biomedical subjects

S Kakumu

Publications and source records attributed to S Kakumu.

At least 109 records · Page 6Linked to original sources

PubMed1992

Effects of transforming growth factor-beta 1 against the inhibitory action of interferon on DNA synthesis and viral replication in hepatitis B virus DNA-transfected cell.

Studies were undertaken to examine the effects of recombinant human transforming growth factor beta 1 (TGF-beta 1) on DNA synthesis and antiviral actions of interferons (IFNs) in HepG2 cell, a hepatoma cell line, transfected with hepatitis B virus (HBV) DNA. The inhibitory effects of IFN-alpha and -gamma on DNA synthesis of HepG2 cells were enhanced in a dose-dependent manner by a simultaneous addition of TGF-beta. The degree of suppression by the reagents was greater in HBV-nontransfected cells than in transfected cells. Inhibition of DNA synthesis was not due to direct cytotoxic effects of the additives, since the viability of HepG2 cells was comparable in the control and treated cultures as determined by trypan blue exclusion. Treatment of HBV DNA-transfected HepG2 cells with IFNs resulted in decrease in production of HB surface and e antigens, and in the level of HBV DNA, but TGF-beta reversed the IFN-induced antiviral state in HBV DNA-transfected HepG2 cells. TGF-beta had no direct effect on HBV replication. These results indicate that rTGF-beta 1 exerts a differential effect against the inhibitory actions of IFN on DNA synthesis and viral replication in HepG2 cells.

DNA, Viral↗

PubMed1992

Immune response of peripheral blood mononuclear cells to antigenic determinants within hepatitis B core antigen in HB virus-infected man.

Residues 72-146 within hepatitis B core Ag (HBcAg) represent T-cell recognition site in HB-virus-infected man. This study was undertaken to define critical residues involved in the immunogenicity of dominant T-cell determinants of HBcAg. For this purpose, p120-131 and its analog (p120-131 [A] containing alanine substitutions at residues 122 and 125, which were identified as epitopic residues in mice, were synthesized. These peptides and recombinant HBcAg were analyzed for their ability to stimulate peripheral blood mononuclear cells (PBMC) from 25 patients with chronic HBV infection and three patients with acute hepatitis B. PBMC from 18 out of 28 patients showed significantly increased IFN-gamma production and proliferative response in the presence of recombinant HBcAg. Eight patients responded to the two peptides, while 12 patients did not. Four patients responded only to p120-131, and four displayed a response only to p120-131 [A]. The responses to the two peptides were similar among HBeAg-positive and anti-HBe-positive patients, and did not depend on disease activity, except for HBeAg-positive asymptomatic carriers in whom there was no response to any additive. These results indicate that immune responses to p120-131 and its analog were similar in our patient groups. The dominant epitopic residues in this region of HBcAg may differ between man and mouse.

Adult↗

PubMed1992

Localisation of intrahepatic interleukin 6 in patients with acute and chronic liver disease.

AIM: To evaluate the role of local interleukin 6 (IL-6) in the pathogenesis of acute and chronic liver disease. METHODS: The cellular site of IL-6 in cryostat sections of liver from 31 patients with liver disease was examined using indirect immunofluorescence with a monoclonal antibody. RESULTS: IL-6 staining in sinusoidal endothelial cells was very noticeable and diffusely distributed in the lobules of specimens of acute viral hepatitis. IL-6 expression in endothelial cells, particularly in necrotic areas of hepatocytes, was increased and was accompanied by enhanced expression in Kupffer cells. In contrast, IL-6 staining in infiltrating mononuclear cells was prominent in portal tracts, and the numbers of cytokine positive cells were greater in specimens of chronic active hepatitis compared with chronic persistent hepatitis. In non-specific reactive hepatitis intrahepatic expression of IL-6 was minimal, while in alcoholic liver fibrosis the cytokine distribution in the lobules was similar to that of acute viral hepatitis. CONCLUSIONS: These results indicate that locally produced IL-6 contributes to the inflammatory process and immunological response in acute and chronic liver disease.

Acute Disease↗

PubMed1992

Cellular immune responses of peripheral blood mononuclear cells to HBV antigens during chronic and acute HBV infection.

Patients with acute self-limited and chronic HBV infection were studied to determine their in vitro cellular immune response to HBV antigens. In interferon-gamma production cultures which were evaluated as an indicator of cellular immune response, peripheral blood mononuclear cells from patients with HBeAg-positive chronic hepatitis showed elevated response to HBcAg, while those from HBeAg-positive asymptomatic carriers revealed no response to either HBcAg or HBeAg. HBeAg-stimulated interferon-gamma production was higher in anti-HBe-positive chronic hepatitis and asymptomatic carriers than that in HBeAg-positive patients. Interferon-gamma production against HBcAg was shown to be HLA class II restricted by blocking assay using monoclonal antibodies. HBsAg with or without pre-S2 did not amplify interferon-gamma production of patients with chronic hepatitis. In acute hepatitis B, both envelope and nucleocapsid antigens induced greater interferon-gamma production than in chronic HBV carriers. These results indicate that the patients with acute hepatitis responded more to HBV antigens compared with chronic HBV carriers. Furthermore, enhanced cellular immune responses, particularly to HBeAg, were observed in anti-HBe-positive patients compared to HBeAg-positive patients during chronic HBV infection, suggesting that the poor response to HBeAg in HBeAg-positive patients may account for the failure to clear HBV.

Adult↗

PubMed1992

[Endoscopic brushing cytology of esophageal lesions].

Endoscopic esophageal biopsy and brushing cytology were performed simultaneously in 121 cases, 25 of which were diagnosed as esophageal cancer by histologic examination of surgically resected material or at autopsy. Correct diagnosis was made in 88% of the cancer cases by endoscopic biopsy, and the same diagnostic rate was obtained by brushing cytology. Combination of the two methods revealed the cancer in 96% of the cases. There were no cases diagnosed as false-positive or false-negative by cytology. Three cancer cases were diagnosed as suspicious by cytology. Definite diagnosis was not made because of paucity of cells on the slide or of cellular atypism. For the improvement of accuracy in cytologic diagnosis it is important to sample adequate amount of cells, and in situ carcinoma cells should be differentiated from benign atypical cells in esophagitis.

Adult↗

PubMed1991

Treatment with human gamma interferon of chronic hepatitis B: comparative study with alpha interferon.

A pilot study was designed to determine the tolerance and effectiveness of natural or recombinant gamma interferon in patients with chronic hepatitis B. Sixteen patients received 0.5 to 3.0 million units (MU) per day of gamma interferon (IFN-gamma) for 7 days. Nineteen chronic hepatitis B patients who were treated with 5-6 MU leukocyte-derived alpha interferon (IFN-alpha) daily served as controls. All completed the treatment schedule. IFN-gamma exerted mild, but significant inhibitory effects (P less than .05) on serum DNA polymerase levels. However, the changes were significantly less (P less than .001) than those seen with IFN-alpha therapy when compared with percent change from basal values. In contrast, serum 2', 5'-oligoadenylate synthetase (2-5 AS) activities were markedly enhanced to a similar extent during therapy with both IFNs. Serum beta 2-microglobulin values were significantly increased by administration with both IFNs, although higher values were seen with IFN-gamma. Five patients received 1 MU IFN-gamma for 28 consecutive days and their HBeAg levels similarly decreased as those seen in patients treated with IFN-alpha. Side effects seemed to be greater during IFN-gamma therapy than IFN-alpha despite the lower doses used. The antiviral effect on serum HBV levels appeared less with IFN-gamma than with IFN-alpha. Alternatively immunomodulatory functions may have been enhanced with IFN-gamma in patients with chronic HBV infection.

Adolescent↗

PubMed1991

Apoptosis in cultured rat hepatocytes: the effects of tumour necrosis factor alpha and interferon gamma.

We investigated the cytotoxic effects of tumour necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) on rat hepatocytes in culture. Under phase contrast microscopy, we found a small number of dying hepatocytes in control cultures, each having been transformed into a cluster of small spheres. Under transmission electron microscopy, these cells showed the characteristics of apoptosis. TNF alpha and a combination of TNF alpha and IFN gamma exerted a cytotoxic effect, whereas IFN gamma showed no significant cytotoxicity when assessed by neutral red assay and by measuring LDH activity in culture medium. Under phase contrast microscopy, the number of apoptotic cells increased with the addition of either TNF alpha or IFN gamma, and markedly with the addition of both. DNA extracted from apoptotic cells cultured with TNF alpha and IFN gamma was fragmented, and a set of bands of the '200 bp ladder', which is characteristic of the DNA of apoptotic cells, was observed in agarose gel electrophoresis. These findings indicate that cultured hepatocytes die from apoptosis. TNF alpha killed cultured rat hepatocytes by increasing apoptosis, and this effect was potentiated by the addition of IFN gamma, which by itself was also weakly cytotoxic.

Animals↗

PubMed1991

Activity of antibodies to hepatitis C virus of patients with chronic non-A, non-B hepatitis decreases during interferon alpha therapy.

The activity of antibodies to hepatitis C virus (anti-HCV) was investigated in 80 patients with chronic non-A, non-B liver diseases. Anti-HCV antibodies were positive in 82.5% (66/80), and the titers were 1 for 18 patients, 2 for 40 and 3 for 8, respectively. The frequency of anti-HCV was significantly lower in patients with chronic persistent hepatitis (8/13, 61.5%) than in those with chronic active hepatitis (42/49, 85.7%) (P less than 0.05). There was no significant difference in the distribution of anti-HCV titers among the different stages of hepatitis. There was no correlation between anti-HCV titer and histology activity index score in chronic hepatitis. Activity of anti-HCV decreased more frequently in the patients who responded to interferon alpha (IFN alpha) therapy (8/22, 36.4%) than in those who did not (0/9, 0%) (P less than 0.05). These results indicate that anti-HCV activity does not correlate with the activity or disease stage of chronic hepatitis, but that anti-HCV activity decrease more frequently during IFN alpha treatment in patients who responded to IFN alpha therapy.

Adult↗

PubMed1991

Effect of sizofiran, a polysaccharide, on interferon gamma, antibody production and lymphocyte proliferation specific for hepatitis B virus antigen in patients with chronic hepatitis B.

To examine whether sizofiran (SPG), a polysaccharide isolated from Schizophyllum commune Fries, could modulate the immune response of immunocompetent cells to hepatitis B virus (HBV) nucleocapsid antigens, we investigated in vitro the production of interferon-gamma (IFN-gamma) and antibody (antibody to HB core and e antigens; anti-HBc and anti-HBe), and proliferation by peripheral blood mononuclear cells (PBMC) from six patients with chronic hepatitis B and four control individuals in the presence of recombinant HBcAg and purified HBeAg. Sizofiran alone in culture and in combination with HBV Ag was found to enhance IFN-gamma production and the proliferative response of PBMC from the patients compared with corresponding medium or HBV Ag alone culture. In contrast, antibody production was not elicited by SPG alone, but amplified by the drug in HBcAg-stimulated culture. In vitro leukocyte IFN-alpha addition increased IFN-gamma production, but suppressed the proliferation of PBMC from both controls and patients in the presence or absence of SPG and HBV Ag. These results indicate that SPG is able to modulate both cellular and humoral immune responses specific for nucleocapsid antigens in patients with chronic hepatitis B.

Hepatitis B↗

PubMed1991

Effects of TJ-9 Sho-saiko-to (kampo medicine) on interferon gamma and antibody production specific for hepatitis B virus antigen in patients with type B chronic hepatitis.

To examine whether Sho-saiko-to (kampo medicine) could modulate the immune response of immunocompetent cells to hepatitis B virus (HBV)-associated antigens, we investigated in vitro interferon gamma (IFN-gamma) and antibody (antibody to HB core and e antigens; anti-HBc and anti-HBe) production by peripheral blood mononuclear cells (PBMC) from eight patients with chronic active hepatitis (CAH) (four with HBeAg and four with anti-HBe) in the presence of recombinant HBcAg and purified HBeAg. IFN-gamma and antibody production were measured using ELISA and RIA, respectively. PBMC from both HBeAg and anti-HBe positive patients generated significantly increased IFN-gamma and antibody (anti-HBc and anti-HBe) production in the culture containing Sho-saiko-to (TJ-9) in a dose-dependent manner in comparison with those of medium alone culture. Similarly, when various concentrations of TJ-9 were added to the HBV antigen-stimulated cultures, TJ-9 was found to enhance both IFN-gamma and antibody production dose-dependently. These results indicate that TJ-9 is able to modulate both cellular and humoral immune responses specific for HBV-associated antigens. These findings also may account for, at least in part, the efficacy of TJ-9 treatment for type B chronic hepatitis.

Adjuvants, Immunologic↗

PubMed1991

Detection of pre-C and core region mutants of hepatitis B virus in chronic hepatitis B virus carriers.

We analyzed the pre-C and core region of hepatitis B virus (HBV) DNA by a polymerase chain reaction in 22 chronic carriers. In 9 hepatitis B e antigen-positive asymptomatic carriers, a single DNA band was detected at the expected size, whereas additional shorter DNA bands were observed in 7 out of 11 patients with chronic hepatitis. The smaller-sized DNAs from one chronic hepatitis patient had various lengths of deletions spanning from 105 to 183 bp in the middle of the core gene, and all deletions included common nucleotide sequences. All of the smaller-sized DNAs from the other patients proved to be variant core genes. They were deleted in similar regions by Southern analysis using oligonucleotide probes. A follow-up study revealed that four out of seven chronic hepatitis patients with a short core gene seroconverted to antibody to hepatitis B e antigen, but those with only a "wild type" did not. In another set of sequence studies, clones isolated from two chronic carriers displayed heterogeneity of the pre-C and core gene which was more often present in sera with normal alanine aminotransferase levels than with abnormal levels. These results suggest that mutant HBV alters the host immune response, and may modulate the clinical course of HBV infection. An alternative possibility is that chronic hepatitis selects for mutant forms.

Adolescent↗

PubMed1991

T cell lines reactive with hepatitis B core and E antigens in patients with chronic hepatitis B.

Hepatitis B virus (HBV)-associated nucleocapsid antigen (HB core and HB e) is believed to be a major target for T cell-mediated hepatocellular damage in chronic HBV carriers. Studies were undertaken to determine whether both nucleocapsid Ag could be recognized by T cell lines from peripheral blood mononuclear cells (PBMC) from patients with chronic hepatitis B. After cultivation in the presence of rHBcAg or purified HBeAg, growing cells were cloned by limiting dilution in the presence of PHA, IL-2 and allogenic feeder cells. Four HBcAg-reactive and three HBeAg-reactive T cell lines from two patients were generated by proliferation assays. None of the cell lines responded to HB surface Ag or PPD. Four lines were of the CD8+ CD11b- cytotoxic phenotype, two of the CD4+ Leu8- helper phenotype, and the remaining one consisted of mixed populations of CD4+ Leu8+ and CD4+ Leu8- cells. Cross-reactivity study showed that a HBcAg-induced CD4+ T cell line responded to HBeAg, and similarly a HBeAg-induced CD8+ T cell line responded to HBcAg. The reactions were inhibited by HLA class II antibody, but not by class I Ab.

Adult↗

PubMed1991

In vitro production of antimitochondrial antibody by peripheral blood mononuclear cells in patients with primary biliary cirrhosis.

Peripheral blood mononuclear cells from patients with primary biliary cirrhosis (PBC) were studied for their ability to produce antibodies to mitochondrial antigens (antimitochondrial antibody, AMA and anti-pyruvate dehydrogenase complex, anti-PDC), using dot-immunobinding and ELISA assay. 2 x 10(6) B cells alone and the mixture of 1.4 x 10(6) T plus 0.6 x 10(6) B cells from patients with serum AMA+ PBC spontaneously produced similar amounts of AMA and anti-PDC. Coculture experiments of T and B cells showed that anti-PDC production was significantly greater in pokeweed mitogen (PWM)-stimulated cultures than in unstimulated ones. The reactivities of antibodies to mitochondrial antigens were inhibited by M2 mitochondrial antigen-enriched fraction. Ursodeoxycholic acid added to cultures resulted in a significant inhibition for production of immunoglobulins and anti-PDC (IgG and IgM). Spontaneous production of AMA or anti-PDC was not detected in patients with AMA- PBC, chronic viral hepatitis and healthy controls, nor could it be induced by PWM in either group. EBV-transformed B cell line established from a AMA+ PBC patient produced high levels of AMA and IgM class anti-PDC. These findings indicate that antibody to a specific mitochondrial antigen in patients with PBC may be produced in T cell-dependent and-independent manner.

Adult↗

PubMed1991

Anti-hepatitis C antibodies in patients with chronic non-A, non-B hepatitis: relation to disease progression and effect of interferon alpha.

The activity of antibodies to hepatitis C virus (anti-HCV) was investigated in 80 patients with chronic non-A, non-B liver diseases. Serum anti-HCV titer was determined by the "Ortho-HCV" enzyme-linked immunosorbent assay with some modifications to quantify the activity. Anti-HCV was positive in 82.5% of cases (66/80). Anti-HCV occurred significantly less often in the patients with chronic persistent hepatitis (8/13, 61.5%) than in those with chronic active hepatitis (42/49, 85.7%) (p less than 0.05). Anti-HCV titer of the patients with chronic persistent hepatitis and that with chronic active hepatitis was significantly higher than that with liver cirrhosis (p less than 0.01 and p less than 0.05). There was no correlation between anti-HCV titer and histology activity index in chronic hepatitis. Serial study demonstrated that anti-HCV titer decreased more frequently in the patients who responded to IFN alpha therapy (11/22, 50.0%) than in those who did not respond to IFN alpha therapy (0/10, 0%) (p less than 0.01). These results indicate that anti-HCV level does not correlate with the activity of hepatitis, but that it decreases in accordance with the disease progression to liver cirrhosis or with the response to IFN alpha therapy.

Adult↗

PubMed1991

Serum interleukin 6 levels in patients with chronic hepatitis B.

Studies were undertaken to evaluate the role of interleukin 6 (IL-6) in the pathogenesis of chronic hepatitis B. Using recently developed sensitive and specific enzyme-linked immunosorbent assay, we determined serum levels of IL-6 in patients with chronic active hepatitis B (B-CAH), chronic persistent hepatitis B (B-CPH), and primary biliary cirrhosis (PBC). Serum IL-6 activity tended to increase in patients with B-CAH (38.4 +/- 68.0 pg/ml) (+/- SD), compared with controls (9.7 +/- 6.8 pg/ml), although the difference was not significant because of the wide scatter in values. IL-6 levels in B-CPH and PBC were similar to those of controls. There was a significant correlation between the levels of IL-6 and aminotransferase in B-CAH. In addition, IL-6 activity was significantly enhanced during acute exacerbation of the illness, accompanied by clearance of HBeAg. Patients who received IFN-alpha and IL-2 therapy showed depressed IL-6 activity during treatment, and a rebound beyond pretreatment values after cessation of therapy. These findings suggest that IL-6 plays a role in the development of chronic hepatitis B, and it may contribute, at least in part, to the elimination of HB virus.

Adult↗

PubMed1990

In vitro production of antibody to hepatitis B core and E antigens by peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection.

To evaluate the relative immunogenicity of and the mechanism for production of antibody to hepatitis B core (HBc) and hepatitis B e (HBe) Ag, we investigated the in vitro anti-HBc and anti-HBe production by PBMC from 25 patients with chronic active hepatitis (CAH) (15 with HBeAg and 10 with anti-HBe) and 12 ASC (5 with HBeAg and 7 with anti-HBe) in the presence of PWM, rHBcAg, or purified HBeAg. PWM-stimulated culture produced higher titer anti-HBc (mean % inhibition +/- SD = 73 +/- 23%, p less than 0.001) than anti-HBe (34 +/- 17%). HBcAg stimulation elicited greater anti-HBc response (43 +/- 26%, p less than 0.001) than did HBeAg for anti-HBe (26 +/- 12%). Both HBcAg and HBeAg induced equivalent anti-HBe response. Anti-HBc production in response to HBcAg was higher in CAH patients (51 to 55%) than in asymptomatic carriers of hepatitis B surface Ag (22 to 28%) irrespective of their HBeAg/anti-HBe status, but reflecting serum anti-HBc value. Similar findings were noted in HBeAg-stimulated anti-HBe production for the two patient groups. In HBeAg- and anti-HBe-positive CAH, HBcAG-stimulated anti-HBc production was similar in T (1.4 x 10(6)) and B (0.6 x 10(6)) cells coculture, and B cells (2 x 10(6)) alone culture. However, in the HBeAg-stimulated culture, T plus B cells produced significantly higher titer anti-HBe than B cells alone did. These results indicate that HBcAg has a relatively higher immunogenicity in terms of antibody production as compared to HBeAg. Furthermore, HBcAg was shown to function as a T cell-dependent and -independent Ag, whereas HBeAg is T cell-dependent during chronic hepatitis virus B infection in man.

Antibody Formation↗

PubMed1990

Production of tumor necrosis factor, interleukin 1, and interferon-gamma by peripheral blood mononuclear cells from patients with primary biliary cirrhosis.

Since patients with primary biliary cirrhosis (PBC) have evidence of abnormal function of the immune system, we evaluated production of various cytokines by peripheral blood mononuclear cells (PBMCs) and monocytes from patients with this disease, using an enzyme-linked immunosorbent assay. The mean amounts of production of tumor necrosis factor alpha(TNF alpha), interleukin 1 beta (IL1 beta), and interferon-gamma (IFN-gamma) by PBMCs from patients with PBC tended to be increased in cultures in the presence of stimulating agents in comparison with controls, but there was no significant difference because of a wide scatter of results. Monocytes from PBC patients also tended to produce higher amounts of TNF alpha and IL1 beta than control monocytes did, although the percentage of monocytes in PBMCs was similar in PBC and controls. A significant correlation was found between TNF alpha production and IL1 beta production in PBC patients. The number of TNF alpha or IFN-gamma positive infiltrating mononuclear cells detected by immunohistochemical staining in liver biopsy sections correlated with the production of these cytokines by PBMCs in vitro. However, cytokine production did not correlate with serum biochemical or hepatic histologic findings, except for serum alkaline phosphatase values. In patients with type B chronic active hepatitis, IL1 beta and IFN-gamma production was similar to controls, while TNF alpha production tended to be enhanced. Thus the cytokines studied here may play some role in the pathogenesis of PBC.

Adult↗

PubMed1990

Immunohistochemical studies of intrahepatic tumour necrosis factor alpha in chronic liver disease.

To determine the intrahepatic production of tumour necrosis factor alpha (TNF alpha) in chronic liver disease three monoclonal antibodies were used against TNF alpha in immunohistochemical studies of liver tissue sections from patients with chronic liver disease. All three monoclonal antibodies stained infiltrating mononuclear cells. Monoclonal antibody II 7C2 also stained the cytoplasm or nucleus, or both, of a varied number of hepatocytes from nine patients with chronic hepatitis B virus infection, suggesting that the antigenic epitope related to hepatitis B core antigen (HBcAg) crossreacted with II7C2. The other two monoclonal antibodies, III2F3 and IV3E5, stained significantly larger numbers of mononuclear cells in cases of chronic active hepatitis B than in chronic persistent hepatitis B, or hepatitis B related liver cirrhosis. III2F3 stained significantly larger numbers of mononuclear cells in non-A, non-B chronic active hepatitis than in chronic persistent hepatitis B or hepatitis B related liver cirrhosis. These results indicate that TNF alpha is produced and secreted by infiltrating mononuclear cells in focal inflammatory areas of the liver, and suggest that TNF alpha may have a role in the inflammatory activity of chronic liver disease.

Antibodies, Monoclonal↗