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Biomedical subjects

B Portmann

Publications and source records attributed to B Portmann.

At least 235 records · Page 13Linked to original sources
PubMed1975

A dog model of fulminant hepatic failure produced by paracetamol administration.

Oral administration of graded doses of paracetamol to dogs produced hepatic necrosis with some similarities to the clinical syndrome seen in man following a paracetamol overdose. Coma, with raised levels of arterial ammonia, was produced and the aspartate aminotransferase levels became markedly elevated in 2 animals who survived more than 24 h. However, the extent of the hepatic necrosis and the time of survival following paracetamol administration were too variable for this model to be of value for the testing of new methods of temporary liver support. When paracetamol was given by intraperitoneal injection many of the animals died of respiratory distress. Significant methaemoglobinaemia was detected, which was associated with a reduction in the arterial partial pressure of oxygen and was partly reversed by the administration of methylene blue.

Acetaminophen↗
PubMed1975

Causes of death in fulminant hepatic failure and relationship to quantitative histological assessment of parenchymal damage.

The clinical course and causes of death in 132 consecutive patients with fulminant hepatic failure and grade III or IV encephalopathy have been reviewed. 105 patients died and in 96 of these an autopsy examination was performed. In 36 patients there was cerebral oedema and the mean age of this group was significantly younger than the other fatal cases. In 28 patients death was attributed to major haemorrhage which originated in the gastrointestinal tract in 25. The prothrombin time ratio was not significantly greater in patients with major bleeding than in those without but they did have a significantly lower platelet count. Sepsis contributed to death in 12 patients. In 25 patients massive hepatic necrosis only was found at autopsy and death was considered to be due solely to hepatic failure. The degree of hepatocyte loss was assessed in 80 fatal cases by a histological morphometric technique on a needle specimen of liver taken immediately post-mortem. The proportion of the liver volume occupied by hepatocytes (hepatocyte volume fraction, HVF) was greatly reduced in all patients (normal 85+/-SD 5 percent) but the mean value was significantly higher in the patients dying with sepsis, cerebral oedema or haemorrhage than in the group in whom death was attributed solely to hepatic failure. There were ten patients in whom liver function was improving at the time of death which was due to cerebral (9) or haemorrhage (1). These observations suggest that many patients presently dying from fulminant hepatic failure may be expected to survive, once more effective therapy is available for the complications of the illness.

Acetaminophen↗
PubMed1974

Cell-mediated immunity to human Tamm-Horsfall glycoprotein in autoimmune liver disease with renal tubular acidosis.

Cell-mediated immune responses to Tamm-Horsfall glycoprotein isolated from human urine were investigated using the leucocyte migration test. Abnormal responses were found in 91% of patients with active chronic hepatitis or primary biliary cirrhosis with an associated renal tubular acidosis (R.T.A.) but in only 19% of those without R.T.A. In nearly all of a group of patients without autoimmune liver disease and in a control group of normal subjects results were within normal limits. In addition, using an immunofluorescent technique with rabbit antibody to human Tamm-Horsfall glycoprotein, it was possible to show the presence in human liver cell membrane of material reacting immunologically as Tamm-Horsfall. These findings suggest that the development of an immune response to this glycoprotein, initiated by release of cross-reacting antigens from damaged hepatocytes, could be the mechanism underlying the occurrence of R.T.A. in some patients with autoimmune liver disease.

Acidosis, Renal Tubular↗
PubMedDate not supplied

Relapse following treatment withdrawal in patients with autoimmune chronic active hepatitis.

A prospective study was performed to evaluate the outcome of treatment withdrawal in 30 patients with "autoimmune" chronic active hepatitis in remission for periods of 1.5 to 9 years on maintenance corticosteroid and azathioprine therapy. Reactivation of disease, with marked rises in serum aminotransferase level (mean 668 +/- S.D. 458 IU per liter) and accompanied by severe symptoms, occurred in 25 (87%) patients within 52 weeks (median 9 weeks; range 5 to 52) and was associated with the histological features of piecemeal necrosis and lobular hepatitis in all 20 liver biopsies examined. Age, sex, duration of disease and remission, presence of cirrhosis, autoantibody status, or immunoglobulin levels did not differentiate patients who relapsed from those who remained in remission. The response to reinstitution of treatment with prednisolone was satisfactory in 25 patients and clinical and biochemical abnormalities resolved within 10 weeks (median 6; range 3 to 10), death occurred in one patient within 48 hr of readmission to hospital.

Adolescent↗
PubMedDate not supplied

Hepatic peptidyl prolyl hydroxylase activity and liver fibrosis--a prospective study of 94 infants and children with hepatobiliary disorders.

To assess whether hepatic peptidyl prolyl hydroxylase (PPH) activity could serve as a practical quantitative indicator of hepatic fibrosis or aid in the categorization, diagnosis or prognosis of hepatobiliary disorders in infancy and childhood, the activity of this enzyme has been determined prospectively by a tritium release method in 97 biopsies from 94 infants and children with the following conditions: acute hepatitis of infancy, 10 patients; extrahepatic biliary atresia, 13; previous hepatitis of infancy, 8; alpha-1-antitrypsin deficiency, 6; chronic active hepatitis, 17; chronic persistent hepatitis, 5; glycogen storage disease, 5; and 25 patients with a miscellanea of other liver disorders. PPH activity was considered in relation to diagnosis, biochemical and histological abnormality and subsequent prognosis over a 4-year period. Five liver biopsies which showed no histological abnormality were considered as "controls" having PPH values of 0.72 +/- 0.47 (mean +/- S.D.). PPH activity was significantly elevated in acute hepatitis of infancy, 9 of the 10 infants having PPH greater than 1.66 units (i.e., mean +/- 2 S.D. of the "control" value). Nine infants (70%) with extrahepatic biliary atresia also had PPH activity above this value, as did two with alpha-1-antitrypsin deficiency and 12 patients all in different diagnostic categories. PPH activity did not correlate with hepatic fibrosis as indicated by hepatic hydroxyproline concentration or by histological assessment, or with biochemical tests of liver function within any diagnostic group or in the series as a whole. PPH activity was similar in biopsies with and without histological features of cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Acute hepatitis A infection in hepatitis B chimpanzee carriers.

Two hepatitis B virus carrier chimpanzees which were superinfected with hepatitis A virus developed acute hepatitis followed by the production of antibodies to hepatitis A virus. The Southern blot technique employed to monitor liver hepatitis B virus DNA revealed that the amount of viral DNA in both animals was significantly reduced during the acute phase of hepatitis A infection. The levels of plasma hepatitis B DNA polymerase activity were also reduced in one chimpanzee. The high titers of HBsAg in the circulation remained unchanged throughout the study, and antibodies to the surface antigen and to e antigen were not detected. The morphological lesions in the liver were severe in one chimpanzee from whom one specimen showed both periportal focal necrosis and zonal parenchymal necrosis.

Animals↗
PubMedDate not supplied

Late onset hepatic failure: clinical, serological and histological features.

The clinical, laboratory and histological features of 47 patients with what is defined as late onset hepatic failure are reviewed. Twenty-five of the patients were female and 22 male with a median age of 45 years. Hepatic dysfunction was severe as evidenced by the prolongation of prothrombin time (median = 32 sec, range = 17 to 120 sec). In only four cases was a viral etiology proven (2 hepatitis B, 2 hepatitis A) although the similarity of the clinical features to patients with fulminant viral hepatitis--apart from the longer period of illness prior to the onset of encephalopathy (median = 9 weeks, range = 8 to 24 weeks)--made non-A, non-B infection a possibility in the remainder. There were also similarities to chronic active hepatitis with low titer antibodies to smooth muscle or antinuclear factor in 17% and elevation of the serum IgG in 49%. Liver biopsy in 5 of 8 survivors more than 1 year after initial presentation showed chronic active hepatitis in three. Lobular inflammatory infiltrate, bridging necrosis and multilobular collapse were the features of the acute stage of illness in both the survivors and fatal cases. The patients given corticosteroids did not have a statistically significant improvement in survival, and overall mortality for the series was 81%. Hepatic transplantation, successfully performed in one patient, would appear to offer the best chance of survival for the majority of these patients.

Adolescent↗
PubMedDate not supplied

Infantile liver giant cells: immunohistological study of their proliferative state and possible mechanisms of formation.

The mechanism of liver giant cell formation is not clarified. Some authors consider the giant cells regenerative, others, degenerative. Paraffin sections of 10 archival cases of idiopathic neonatal hepatitis (INH), 8 of extrahepatic biliary atresia (EHBA), and 5 normal liver samples were immunostained with two well-characterized cell proliferation markers: anti-PCNA monoclonal antibody (MAb) (clone PC-10) and MAb MIB-1, which detects Ki-67, a nuclear proliferation-related antigen. In addition, polyclonal antibody to carcinoembryonic antigen (CEA) was used to identify remnants of canalicular, therefore hepatocytic, membranes in giant cells. Quantitative analysis of immunostaining was done by estimating PCNA and Ki-67 indices separately in giant cells and in nongiant hepatocytes. In normal samples, mean PCNA and Ki-67 indices were 1. 22% and 0.74%, respectively. In the cases of INH and EHBA, only a small minority of giant cells showed PCNA or Ki-67 staining limited to occasional peripherally located nuclei. PCNA and Ki-67 indices were significantly higher in the non-giant cell compartment. CEA staining was seen only in rare giant cells as centrally located canalicular remnants bordered by polarized nuclei, suggesting that they had been formed from rosettes through dissolution of cell membranes. Other giant cells shared CEA-labeled canalicular membranes with mononuclear hepatocytes in rosettes. These findings indicate that the giant cells in INH and EHBA are not regenerative cells, they are not formed by amitotic division of nuclei in syncytia, and that fusion of rosette-forming hepatocytes is a possible mechanism of their formation.

Antigens, Nuclear↗