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Biomedical subjects

T Masumoto

Publications and source records attributed to T Masumoto.

67 records · Page 4Linked to original sources
PubMed1980

Kidney function in the severely jaundiced dog.

An attempt was made to prepare experimental models of jaundice in order to study the relation between jaundice and kidney function. Choledochal ligation and surgical division as a conventional means of achieving this aim proved useless in satisfying our requirements. The use of the choledochocaval shunt technique that we devised resulted in successful preparation of models of severe jaundice with a resultant total bilirubin value of 19.2 +/- 8.0 mg/dl at 1 week and 23.9 +/- 8.7 mg/dl 3 weeks postoperatively. Through these models the relation between jaundice and kidney function and the resultant histopathologic features of the kidneys were studied. In the animal models a significantly lower value was obtained for both glomerular filtration rate and renal plasma flow at 1 and 3 weeks postoperatively than in the other groups (undergoing choledochal ligation with division and unilateral nephrectomy, respectively). Histopathologic examination of the kidneys of these animals revealed no marked changes in the glomeruli or Bowman's capsule. Characteristic histopathologic features of the kidneys included swelling and exfoliation of epithelial cells because of reabsorption of bile in the proximal tubules and disintegration of the cell membrane.

Acute Disease↗
PubMedDate not supplied

Subclass restriction of immunoglobulin G in liver cirrhosis.

The serum immunoglobulin G (IgG) subclasses were determined in 41 patients with liver cirrhosis (LC) and in 15 normal controls. In 19 cases of LC and in 6 normal controls, the IgG subclasses were also determined in lymphocyte culture supernatants. The determinations were performed by enzyme immunoassay. It was found that the absolute mean IgG1 and IgG3 levels were increased in all LC due to various causes. The mean IgG1 increase was most pronounced in post-hepatitic LC, and the mean percentage of IgG1 to total IgG was also increased in this type of LC in comparison with the normal controls and the other types of LC. The IgG3 fraction was significantly increased in primary biliary cirrhosis (PBC). In alcoholic LC, all IgG subclasses were increased significantly in comparison with normal controls. In lymphocyte culture supernatants from PBC patients, the mean IgG1 and IgG3 levels were increased in supernatants from unstimulated cultures, and the mean IgG1, IgG3, and IgG4 were increased after pokeweed mitogen (PWM) stimulation. In post-hepatitic LC, the mean IgG4 level was increased in both unstimulated culture supernatants and after PWM stimulation. In alcoholic LC, the mean IgG4 level was increased in unstimulated culture supernatants, whereas the mean IgG1 level was increased after PWM stimulation. These findings showed that LC of differing aetiologies exhibited different profiles of IgG subclasses. This may be related to the different aetiological agents and the pathogenesis of the different types of LC.

Female↗
PubMedDate not supplied

Decreased interleukin-2 receptor beta chain expression by peripheral blood lymphocytes in chronic liver disease.

To investigate the decrease in natural killer (NK) activity in chronic liver disease, interleukin-2 receptor beta chain (IL-2R beta) expression was assessed by peripheral blood lymphocytes (PBL) using flow cytometry and an IL-2R beta chain-specific mouse monoclonal antibody. The percentage of IL-2R beta chain-positive PBL was significantly decreased in patients with chronic viral hepatitis, liver cirrhosis and hepatocellular carcinoma in comparison with normal controls (P less than 0.01). Among chronic viral hepatitis patients, it was significantly less in those with chronic active hepatitis than in those with chronic persistent hepatitis (P less than 0.05). Two-colour flow cytometry revealed that the IL-2R beta chain was mainly expressed by CD8+ or CD16+ cells in both the controls and the liver disease patients. CD8dull+ cells (NK cells) constituted more than 60% of the CD8+ cells expressing the IL-2R beta chain. Expression of the IL-2R beta chain with CD8 or CD16 was also significantly decreased in chronic liver disease patients compared with controls. In chronic viral hepatitis, there was a significant correlation between NK activity and the percentage of IL-2R beta+ PBL (P less than 0.001, r = 0.916), as well as between NK activity and the percentage of PBL co-expressing both the IL-2R beta chain and CD16 (P less than 0.001, r = 0.850). These findings suggest that decreased expression of the IL-2R beta chain by PBL may result in diminished NK activity in chronic liver disease.

Adolescent↗
PubMedDate not supplied

Significance of sublobular hepatic necrosis in the progression of chronic hepatitis C.

The clinical characteristics of hepatitis C virus associated chronic liver diseases (C-LD) in 17 patients were compared with hepatitis B virus associated diseases (B-LD) in 47 patients, by analysing the histological findings of the liver and the change in serum alanine aminotransferase (ALT) level. The persistence of the moderate abnormality in ALT (> 100 IU/L) for longer than 1 year was more frequently seen in the C-LD group (P < 0.01), although the severe exacerbation of the disease with ALT higher than 500 IU/L was more frequent in the B-LD group (P < 0.01). The patients with the histological finding of sublobular hepatic necrosis (SN) in the C-LD group progressed to advanced stages more frequently than those with SN in the B-LD group (P < 0.05). Furthermore, nine of 10 patients with SN in C-LD finally progressed to hepatocellular carcinoma (HCC) in 52 +/- 23 months, whereas three of 16 with SN in B-LD developed HCC in 81 +/- 34 months. Although the morphological features of SN in C-LD and B-LD were almost the same, SN in C-LD seemed to be a more significant diagnostic condition for the progression to liver cirrhosis or HCC. The patients with SN in the C-LD group should be closely followed for the early detection of HCC, although further study with a greater number of patients is necessary.

Adult↗
PubMedDate not supplied

Interferon therapy for patients more than 60 years of age with chronic hepatitis C.

Nineteen patients aged > 60 years with chronic hepatitis C (CHC) received interferon (IFN) therapy and a complete response (CR) was achieved by five of them (26%). The incidence of CH with severe fibrosis in this elderly group was significantly higher than in another 52 patients with CHC who were < 60 years of age (the younger group; P < 0.05). There was no significant difference in the hepatitis C virus (HCV) genotype distribution between the elderly group and the younger group. However, the HCV-RNA titre was significantly higher in the elderly group than in the younger group (P < 0.05). There was no significant difference in the efficacy rate of IFN in the elderly and younger groups after standardization of the background factors. In the elderly group, the HCV-RNA titre was significantly lower in the patients achieving CR than in those with no response (P < 0.05). These data suggest that elderly patients with a low HCV-RNA titre can still respond well to IFN therapy.

Adult↗
PubMedDate not supplied

Prediction of interferon-alpha-induced thyroid dysfunction in patients with chronic hepatitis C.

To predict interferon-alpha (IFN-alpha)-induced thyroid dysfunction, anti-thyroglobulin (anti-TgAb) and anti-thyroid peroxidase antibodies (anti-TPOAb) were determined by radio-immunoassay (RIA) before IFN-alpha treatment in 30 patients with chronic hepatitis C in whom the conventional haemagglutination test had failed to detect anti-thyroid auto-antibodies. Seven patients developed thyroid dysfunction during IFN-alpha treatment (transient thyrotoxicosis in four patients, transient hypothyroidism in two, and Graves' disease in one). Anti-TgAb and/or anti-TPOAb were detectable before IFN-alpha treatment in six of these seven patients, while these antibodies were detected before treatment in only four of 23 patients who did not develop any thyroid dysfunction. The prevalence of these antibodies was significantly higher (P = 0.002) in the former group of patients than in the latter. In four patients with detectable anti-TgAb before treatment but no subsequent thyroid dysfunction, the antibody disappeared during IFN-alpha treatment. Haemagglutination tests for anti-thyroid microsomal antibodies have previously been reported to be a useful predictive marker of IFN-alpha-induced thyroid dysfunction. In conclusion, sensitive detection of anti-thyroid auto-antibodies using RIA may also be useful for the prediction of IFN-alpha-induced thyroid dysfunction in patients with a negative haemagglutination test.

Autoantibodies↗
PubMedDate not supplied

The seroepidemiology of hepatitis A and B in a Japanese town.

Sera collected from 1,118 healthy children and adults aged between four years and 90 years during the period 1989 to 1990, were tested for serological markers of hepatitis A virus (HAV) [antibody to HAV (anti-HAV)] and hepatitis B virus (HBV) [hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface antigen (anti-HBsAb)]. The overall prevalence rates of anti-HAV, HBsAg, and anti-HBV were 20.2%, 0.36%, and 5.1%, respectively. No body was found to be positive for anti-HAV below 30 years of age but more than 70% of the adults aged 50 years or over were positive for anti-HAV. The level of exposure of HAV infection is declining in Japan and paradoxically at the same time a vast majority of people are becoming susceptible to more severe illness. The fall in prevalence of HBsAg possibly represents the positive impact of ongoing vaccination programs and other preventive measures against HBV.

Adolescent↗
PubMedDate not supplied

The effectiveness of interferon therapy on occurrence of hepatocellular carcinoma in chronic hepatitis C.

To clarify the effect of interferon (IFN) therapy for chronic hepatitis C (CHC) on the occurrence of hepatocellular carcinoma (HCC), 149 patients who were observed over a period of five years (mean: 7.6 years) were studied. The C-1 group, 33 patients with complete response to IFN; the C-2 group, 55 patients with no response to IFN; and the C-3 group, 61 patients who did not receive IFN. The occurrence rate of HCC was 0.9%/year/person. In the C-1, C-2 and C-3 groups, the rates were 0%, 0.3%, and 1.6%, respectively. The rate in C-1 + C-2 groups was significantly lower than that of the C-3 group (P<0.05). These data suggest IFN may suppress the occurrence of HCC in CHC.

Adolescent↗
PubMedDate not supplied

Positive and negative oral contrast agents for combined abdominal and pelvic helical CT: first iodinated agent and second water.

Combined abdominal and pelvic helical computed tomography (CT) with intravenous contrast media was performed on 19 patients with 400 mL of diluted iodine solution 60 minutes before and 400 mL of water just before CT. The distal small bowel was opacified by the positive contrast agent, and the stomach by the negative contrast agent in all patients. The gastric contents were homogenous, and the density was a mean +/- standard deviation 2.5+/-7.3 HU. The difference between the densities of the gastric contents and of the gastric wall (mean +/- s.d. 80.8+/-20.9 HU) was statistically significant (p<.05). There were no pseudotumors. Thus our protocol, first diluted iodine solution and second water, can be used as a method for the oral administration of contrast agents for combined abdominal and pelvic helical CT with intravenous contrast media.

Administration, Oral↗
PubMedDate not supplied

Serum IL-8 levels and localization of IL-8 in liver from patients with chronic viral hepatitis.

BACKGROUND/AIMS: Interleukin 8 is known as a chemotactic factor for neutrophils and T cells. Such inflammatory cells are observed in the liver tissue in chronic viral hepatitis. However, it is not known whether interleukin 8 relates to hepatic injury in patients with chronic viral hepatitis. Therefore, we determined serum interleukin 8 levels and identified the cells related to interleukin 8 production in liver tissue. METHODOLOGY: Studies were performed on 29 patients with chronic viral hepatitis and 20 normal controls. Serum interleukin 8 levels were assayed using a sandwich ELISA. Immunohistochemical examination was performed to identify the cells related to interleukin 8 production by using a rabbit polyvalent antibody to human interleukin 8. RESULTS: Serum interleukin 8 levels were found to be increased significantly (p<0.05) in patients with chronic viral hepatitis compared with normal controls. They were also increased significantly in patients with chronic active hepatitis compared with chronic persistent hepatitis (p<0.05), and during exacerbation stages compared with remission stages (p<0.05). Out of the 10 patients examined immunohistochemically, interleukin 8 positive cells in the liver tissue were visualized in 7 patients and observed mainly along sinusoids. There was significant correlation between serum interleukin 8 levels and intensity of staining for interleukin 8 in the liver tissue (p<0.05, r=0.869). CONCLUSIONS: Interleukin 8 plays a role in hepatic injury in patients with chronic viral hepatitis, and is mainly produced by nonparenchymal cells in the liver.

Adult↗