Tissue polypeptide antigen (TPA) in chronic active hepatitis and mild liver diseases.

Tissue polypeptide antigen (TPA) is a non-specific tumor marker with a broad reactivity. Increases in TPA are also observed in benign liver diseases. We conducted this study to evaluate the usefulness of TPA serum level determination in 15 patients with chronic active hepatitis (CAH) and in 30 patients with mild liver diseases (MLD) diagnosed at the time of evaluation. TPA levels were abnormal in 73.3% of CAH patients and in 40% of MLD patients. CAH patients had significantly higher TPA levels than MLD patients (p = 0.006). There was a significant correlation between TPA and ASAT (r = 0.581 p < 0.00001), suggesting that cytolysis plays an important role in the increase in TPA. A TPA value of twice the normal level will unlikely be due to MLD (specificity 90%). TPA can be used in the clinical characterization of these patients and in the selection of patients for biopsy.     

Antibody to hepatitis B core antigen in chronic active hepatitis.

Antibody to hepatitis B core antigen (anti-HBc), which has been assumed to be a more sensitive indicator of hepatitis B virus replication than hepatitis B surface antigen (HBsAg), was detected in the sera of 26 of our 65 patients with HBsAg-negative chronic active hepatitis. Thus despite the absence of HBsAg the liver disease could be the consequence of chronic infection with hepatitis B virus in these patients. They differed, however, from a group of 35 patients with HBsAg-positive hepatitis in being older on average and having less active liver lesions. The two groups could represent either two stages of chronic infection with hepatitis B virus or two types of response to it.     

Cellular and humoral immunity to hepatitis-B surface antigen in active chronic hepatitis.

The hepatitis-B surface antigen (HBsAG) may be persistently present in the serum in a few cases of active chronic hepatitis but the cause of the disease in most patients is unknown. In a study of 39 HBsAg-negative cases cell-mediated immunity to HBsAg was observed in 24 (62%), suggesting a high frequency of previous infection with the hepatitis-B virus. Hepatitis-B surface antibody was detectable by radioimmunoassay in six patients, in all of whom complexes of HBsAg were present in the serum on electron microscopy. Out of 12 patients with HBsAg-positive active chronic hepatitis who were also studied eight, including all those untreated at the time, showed a cellular response to the antigen. Evidence of sensitization to a liver-specific cell surface lipoprotein was found with similar frequency in the two groups. These results are consistent with the hypothesis that hepatitis-B virus infection is important in initiating the disease in many cases of active chronic hepatitis and that sensitization to the liver cell membrane antigen is the autoimmune process responsible for the perpetuation of the liver injury.     

Epinephrine-binding plasma-membrane antigens in rat liver.

Detergent extracts of isolated rat liver plasma membranes were analysed in two-dimensional immunoelectrophoresis against antiserum to plasma membranes. Enzyme staining of the immunoprecipitates revealed the presence of about ten antigens with nucleoside di- and triphosphatase activity. Most of these were earlier shown also to be NADH-neotetrazolium reductase active. In addition, two of these antigens exhibited L-leucyl-beta-naphthylamidase activity. As judged from autoradiography these plasma membrane antigens earlier characterized as multienzyme complexes bound [14C]epinephrine, and the same antigens were labelled regardless of whether membranes or membrane extracts were incubated with the radioactive hormone. The specificity of this binding was established in displacement experiments with unlabelled hormones or their analogues. Another hormone-binding antigen, also identified in the plasma membrane extract did not exhibit any known enzyme activity while three antigens with different enzyme activities had no epinephrine-binding capacity. [14C]Epinephrine-labelled plasma membrane extracts were chromatographed on Sepharose 4B and the fractions obtained were analysed in two-dimensional immunoelectrophoresis combined with autoradiography. Nucleoside di- and triphosphatases of high molecular weights (5000000) were associated with L-leucyl-beta-naphthylamidase activity, while no such associations were detected in a lower molecular weight region (70000). Further immunological studies on the various fractionated antigens provided evidence that at least two of them occurred in both low and high molecular weight fractions. Hormone-binding membrane components in varying concentrations were found throughout the eluted extract.     

The etiology of chronic active hepatitis in Korea.

In a study of apparently normal, healthy Korean Army recruits performed in 1962, we found that 42 of 1,906 screened subjects had elevations of their serum glutamic pyruvate transaminase. Liver biopsies were obtained from 32 of these subjects and 9 of these had a "novel" antigen present, which reacted specifically with a convalescent serum from a case of serum hepatitis. We have recently tested frozen serum obtained from 8/9 of these cases and found that all 8 had HBsAg in their serum which, in some cases, persisted for at least three months. We reviewed the histological specimens from the original 32 cases using newly defined criteria: 18 were diagnosed as chronic active hepatitis and the 8 HbsAg positive cases with the "novel" antigen were in this group. In four of these cases the lesion appeared to progress to cirrhosis during a 3--4 month follow-up period. Since none of the cases had a prior history of hepatitis and no symptoms developed during the follow-up period, our findings emphasize the significance of chronic hepatitis B virus carrier state in the etiology of cryptogenic cirrhosis.     

Sodium-dependent alanine transport in plasma-membrane vesicles from rat liver.

L-Alanine transport was studied in plasma-membrane vesicles from rat liver. A gradient of NaSCN, but not of KSCN, stimulated alanine uptake. Monensin plus carbonyl cyanide p-trifluoromethoxyphenylhydrazone abolished the observed overshoot in uptake. After equilibration of alanine, NaSCN induced uphill transport.     

Therapeutic effect of (+)-cyanidanol-3 in toxic alcoholic liver disease and in chronic active hepatitis

(+)-Cyanidanol-3 is considered to have cytoprotective effect in toxic liver injury. A randomized clinical trial was carried out in alcoholic precirrhotic patients and in chronic active hepatitis with (+)-cyanidanol-3 versus placebo. The daily dose of the drug was 1.5-2.0 g for a one-year period. A: Toxic alcoholic precirrhotic liver disease: 38 patients were treated with (+)-cyanidanol-3, 36 with placebo. We found significant improvement in the subjective symptome like asthenia and anorexia, and in serum aspartate-transaminase (GOT) levels. However, it is possible that the improvement was in part due to abstinence from alcohol. B: Chronic active hepatitis: previously introduced continuous prednisolone therapy (10-15 mg/day) was combined with (+)-cyanidanol-3 in 13 patients and with placebo in 12 controls. The results showed a more favourable, but not significantly better response in patients receiving (+)-cyanidanol-3 versus placebo. We concluded that the drug might be of benefit in some cases with chronic active hepatitis as an adjunct to corticoid therapy.     

Distribution of G-proteins in rat liver plasma-membrane domains and endocytic pathways.

Cryoenzymology techniques were used to facilitate trapping an acyl-enzyme intermediate in beta-lactamase I catalysis. The enzyme (from Bacillus cereus) was investigated in aqueous methanol cryosolvents over the 25 to -75 degrees C range, and was stable and functional in 70% (v/v) methanol at and below 0 degree C. The value of kcat. decreased linearly with increasing methanol concentration, suggesting that water is a reactant in the rate-determining step. In view of this, the lack of incorporation of methanol into the product means that the water molecule involved in the deacylation is shielded from bulk solvent in the enzyme-substrate complex. From the lack of adverse effects of methanol on the catalytic and structural properties of the enzyme we conclude that 70% methanol is a satisfactory cryosolvent system for beta-lactamase I. The acyl-enzyme intermediate from the reaction with 6-beta-(furylacryloyl)amidopenicillanic acid was accumulated in steady-state experiments at -40 degrees C and the reaction was quenched by lowering the pH to 2. H.p.l.c. experiments showed covalent attachment of the penicillin to the enzyme. Digestion by pepsin and trypsin yielded a single labelled peptide fragment; analysis of this peptide was consistent with Ser-70 as the site of attachment.     

Positive selection of hepatitis delta antigen in chronic hepatitis D patients

Liver disease may become ameliorated in some patients with chronic hepatitis D virus (HDV) infection. We present here a study based on longitudinal sampling to investigate the viral dynamics in chronic HDV infection. We examined the HDV variants from different time points, especially those before and after the elevation of serum aminotransferase levels. The datasets from each patient were tested for positive selection by using maximum-likelihood methods with heterogeneous selective pressures along the nucleotide sequence. An average of 4.9%, ranging from 3.1 to 6.8%, of the entire delta antigen sites was regulated by a diversifying selection. Most of the positively selected sites were associated with immunogenic domains. Likelihood ratio tests revealed a significant fitness of positive selection over neutrality of the hepatitis delta antigen gene in all patients. We further adapted a neural network method to predict potential cytotoxic T ligand epitopes. Among the HLA-A*0201 cytotoxic T ligand epitopes, three consistent epitopes across all three genotypes were identified: amino acids (aa) 43 to 51, 50 to 58, and 114 to 122. Three patients (60%) had sites evolving under positive selection in the epitope from aa 43 to 51, and four patients (80%) had sites evolving under positive selection in the epitope from aa 114 to 122. The discovery of immunogenic epitopes, especially cytotoxic-T-lymphocyte ligands, associated with chronic HDV infection may be crucial for further development of novel treatments or designs in vaccine for HDV superinfection.     

Trigger factors and HL-A antigens in chronic active hepatitis

Forty-six patients with histologically verified chronic active hepatitis (CAH) were divided into three groups according to whether the CAH was virus-induced, drug-induced, or cryptogenic. The frequency of the HL-A antigens 1 and 8 was increased in the cryptogenic group while the other groups did not differ significantly from healthy controls. Autoantibodies were often found in high titres in the drug-induced and cryptogenic groups but were infrequent in the virus-induced group.     

Structural characteristics of the liver in experimental chronic hepatitis and its treatment with benzonal

Utilization of general morphological, histochemical, morphometric and electron microscopic methods revealed marked structural changes of the liver in experimental chronic hepatitis and its subsequent correction with benzonal. The drug administration results in reversibility of the process due to significant action of cellular, and especially intracellular regenerative processes. The latter is supported by the presence of 2 types of cells, the 1st of which are characterized by predominant mitochondrial hypertrophy and hyperplasia suggesting increase in hepatocyte energy activity and the 2nd ones by hypertrophy of the elements of the smooth reticulum responsible for metabolism of foreign body substances being typical for the action of inductors of hepatic microsomal enzymes.     

Fractionation of rat liver plasma-membrane regions by two-phase partitioning.

Rat liver plasma membranes, enriched in blood-sinusoidal or bile-canalicular regions by differential and sucrose-gradient centrifugation, were further purified by partitioning in an aqueous polymer two-phase system. This method separates membranes according to differences in surface properties rather than size and density. A several-fold increase in the ratio of leucine aminopeptidase (a bile-canalicular marker) and 5'-nucleotidase to asialo-orosomucoid binding (a blood-sinusoidal marker) was obtained in one fraction, whereas another fraction gave a 2-3-fold increase in ratio of blood-sinusoidal to bile-canalicular markers. Furthermore, the markers for both regions of the plasma membrane, as well as markers for Golgi membranes and lysosomes, showed a heterogeneous behaviour on counter-current distribution.