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Biomedical subjects

F Schaffner

Publications and source records attributed to F Schaffner.

At least 73 records · Page 4Linked to original sources
PubMed1983

In vitro synthesis of IgG and IgM in patients with HBsAg-positive and HBsAg-negative chronic active hepatitis.

Spontaneous and PWM-driven IgG and IgM synthesis was investigated in the PBMC of 15 patients with HBsAg-negative CAH and six HBsAg-positive patients with CAH. PBMC from patients with HBsAg-positive CAH show an impaired IgG synthesis upon stimulation with PWM but an IgM increase similar to that of control subjects. In contrast, PBMC from HBsAg-negative patients with CAH show a trend to spontaneous increased synthesis of IgG and a decrease or lack of IgG and IgM synthesis upon PWM stimulation. Steroid treatment seems to ameliorate these alterations. No differences were found among the three groups of HBsAg-negative chronic active hepatitis (autoimmune, HBsAg-related and cryptogenic). These results indicate that differences of B-cell functions may exist in the two groups of CAH patients, not only in spontaneous B-cell activation or PWM-induced Ig synthesis but also in the different classes of Ig.

Adult↗
PubMed1983

Ornithine carbamoyltransferase deficiency in an adult male patient: significance of hepatic ultrastructure in clinical diagnosis.

Ornithine carbamoyltransferase (OCT) activity was deficient (8% of control) in the liver of a 21-year-old man who died after suddenly becoming comatose. Activities of other enzymes of the urea cycle in the liver were normal. There was no known prior illness or injury; the patient, however, had been taking liquid protein supplements to his diet. Hyperammonemia and orotic aciduria were present, and the concentration of lysine in the plasma was elevated. Survey of earlier reports indicates that neither the specific deficiency of hepatic OCT nor the urine and plasma findings provide a basis for definitive diagnosis of the patient's illness as primary OCT deficiency or as Reye's syndrome. Indeed, the age of the patient at onset of symptoms and the absence of any prodromal infection argue against the OCT deficiency being either primary or a sequel to Reye's syndrome. We suggest that it was secondary to mitochondrial injury caused by an unknown agent. Electron microscopic study of hepatocyte ultrastructure lends support to this view; abnormalities of the patient's mitochondria (bizarre, elongated shapes) do not resemble those seen in Reye's syndrome, nor have abnormalities been found in primary OCT deficiency.

Adult↗
PubMed1981

Methioninemia and myopathy: a new disorder.

A 7 1/2-year-old girl with hypermethioninemia, myopathy, and mental deficiency (IQ = 65) is described. The increased methionine was not associated with deficiency of methionine adenosyltransferase, which was normal or increased in liver, muscle, erythrocytes, and cultured fibroblasts. Methionyl-tRNA synthetase in fibroblasts was normal. The hypermethioninemia and a concurrently increased blood S-adenosylmethionine declined on a diet low in methionine. There was a diffuse, symmetrical, moderate proximal muscle weakness, but muscle atrophy was not discernible, and the deep tendon reflexes were hypoactive but obtainable. Electromyographic abnormalities were not detected. Electron microscopy of muscle revealed 3 to 6 small myelin figures in the region of the I band in nearly every fiber, with occasional myelin figures at other sites also. These myelin figures were more numerous and smaller than those seen accompanying nonspecific myopathies and may reflect a more specific pathological change. Electron microscopy of liver revealed three nonspecific lesions in all hepatocytes: (1) numerous megamitochondria with crystalloid deposit in the matrix; (2) increased numbers of small vesicles of smooth endoplasmic reticulum; and (3) loss of plasma membrane microvilli, with extensive bleb formation and shedding of cytoplasm into Disse's space.

Amino Acid Metabolism, Inborn Errors↗
PubMed1981

Hypermethioninemia associated with methionine adenosyltransferase deficiency: clinical, morphologic, and biochemical observations on four patients.

Four patients with hypermethioninemia were ascertained in neonatal mass metabolic screening programs. Hypermethioninemia has persisted in all cases. There were no other abnormalities in sulfur-amino acid concentrations, and routine serum chemical determinations, including the results of "liver function" tests, were normal. Hepatic methionine adenosyltransferase activity was found to be low, ranging from 7.8 to 17.5% (mean 11.4%) of the normal adult control value. Electron microscopy of liver showed increased smooth endoplasmic reticulum, decreased rough endoplasmic reticulum, and increased lysosomes; short breaks in the outer membranes of mitochondria were present to a variable extent. Despite the persistent hypermethioninemia, which argues for continued deficiency of hepatic MAT, all four children appear well. This ostensible well being may be a result of the normal activity of extrahepatic MATs, as shown for erythrocytes and for cultured fibroblasts and lymphoid cells.

Adult↗
PubMed1980

Mitochondrial abnormalities of liver in primary ornithine transcarbamylase deficiency.

Deficiency of hepatic ornithine transcarbamylase (EC 2.1.3.3) activity in a 17-month-old female patient is described. Enzyme activity was 11% of the mean control value. Electron microscopic examination of the liver specimen, taken by percutaneous needle biopsy, revealed striking abnormalities of the mitochondria: bud-like projections, sausage-link appearance, elongation with short cristae, or the presence of parallel arrays of tubules. The abnormalities do not resemble those seen in Reye's syndrome.

Female↗
PubMed1980

Pericanalicular hepatocytic and bile ductular microfilaments in cholestasis in man.

The cytoplasmic microfilaments of hepatocytes in the pericanalicular area and of bile ductular cells in various types of human cholestasis were examined and compared with those seen in the noncholestatic human liver. An increase in the number of hepatocytic microfilaments with an increase in the apparent density of the filamentous network and in the thickness of bundles of filaments was evident in the vicinity of the bile canaliculi, in the pericanalicular ectoplasm, and in the surrounding cytoplasm in all types of cholestasis but more so in intrahepatic cholestasis. This increase in the number of microfilaments was also seen around undilated canaliculi. Microfilaments were also increased in number beneath the surface of the bile ductular cells facing the cytoplasm but not beneath the rest of the plasma membrane. More microfilaments also were found around ductular cell nuclei. No striking differences were noted between intrahepatic and extrahepatic cholestasis. These findings suggest that microfilaments play a role that is not established in human cholestasis.

Bile Ducts, Intrahepatic↗
PubMed1979

Fatty liver hepatitis and cirrhosis in obese patients.

Liver function and liver biopsy findings were studied in a selected group of 29 overweight patients. Fatty liver, fatty hepatitis, fatty fibrosis and fatty cirrhosis were seen with equal frequency. Diabetes was also present with an equal incidence in each of these four pathologic groups. Lipoprotein abnormalities, particularly type IV hyperlipoproteinemia, were found mostly in the two groups with the lesions with less fibrosis (fatty liver and fatty hepatitis). The pathologic picture resembled that of alcohol and postjejunoileal bypass-induced liver diseases suggesting a common denominator in these three conditions.

Adolescent↗
PubMed1979

Primary biliary cirrhosis as a collagen disease.

Primary biliary cirrhosis is a disease of the small bile ducts with altered immunologic responsiveness often associated with various collagen diseases. All appear to be mediated by immune complex deposition. They probably are all different clinical manifestations of the same disease with different expressions determined by genetic and acquired factors. Therapy should be directed to the most immediate life-threatening problem.

Adrenal Cortex Hormones↗
PubMed1979

Serum bilirubin: a prognostic factor in primary biliary cirrhosis.

We followed up 55 patients with proven primary biliary cirrhosis for several years or until death. A graph of the level of serum bilirubin versus time that was constructed for each patient shows an initial period of variable length in which the serum bilirubin level remained constant. This was followed by a period of rapid rise in serum bilirubin which culminated in the patient's death. Whenever two successive serum bilirubin values taken six months apart exceeded 34 mumol/l (2.0 mg/dl) the patient had entered a late phase of disease and lived an average of 49 months. Ninety-five per cent confidence limits on survival time were 32-74 months. If two successive six month bilirubin values exceeded 102 mumol/l (6.0 mg/dl), calculated survival time was 25 months, and if two successive six month bilirubin values exceeded 170 mumol/l (10.0 mg/dl), survival time was 17 months. Fifteen of the 41 living patients had two consecutive serum bilirubin levels greater than 34 mumol/l (2.0 mg/dl). However, the slope of the rising bilirubin in the living patients is only 35 mumol/l/yr (1.5 mg/dl/yr) compared with 42 mumol/l/yr (2.5 mg/dl/yr) in the dead patients. This means that patients with this disease not may be living considerably longer.

Adult↗
PubMed1979

State of the art. Primary biliary cirrhosis and the immune system.

The immunologic features of diseases associated with primary biliary cirrhosis (PBC) such as Sjörgren's syndrome, scleroderma, rheumatoid arthritis and others are reviewed. Immunologic abnormalities involving both humoral and cell mediated immunity have been found in PBC. The morphologic and immunologic data have been used to propose a pathogenetic mechanism for PBC. Recent studies of penicillamine indicate that the drug may influence liver copper content and the deposition of immune complexes.

Antibody Formation↗