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Biomedical subjects

L W Powell

Publications and source records attributed to L W Powell.

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

Solid phase radioimmunossay for serum ferritin.

A solid-phase "direct" radio immunoassay which is highly sensitive (detecting less than 0.5 ng/ml) and reproducible is described for the assay of ferritin in human serum. The method makes use of specific anti-ferritin antibody prepared using human liver ferritin; It has the advantage that tubes coated with specific antiserum may be stored for later use and lends itself readily to an automated washing procedure. The concentration of ferritin present in the serum of normal males in the population was 56,9 ng/ml (geometric mean) with a 95 percent confidence range of 18 to 180 ng/ml. In normal females the concentration was 34.0 ng/ml (geometric mean) with a 95 percent condidence range of 10 to 143 ng/ml.

Animals↗
PubMed1975

Hepatitis B antigen and antibody in active chronic hepatitis and other liver diseases in Australia. A multicenter collaborative study.

In a multicenter cooperative study, sera from 85 patients with active chronic hepatitis (ACH) were examined for the presence of hepatitis B (Australia) antigen (HBAg) by radioimmunoassay (RIA) and antibody to HBAg (anti-HBAg) by RIA and passive hemagglutination (PHA), the most sensitive currently available techniques. In addition, sera from 83 patients with other liver diseases 98 other hospital patients, and 67 healthy controls were tested. HBAg was detected in 3 of the 85 patients (four percent) with ACH. In a further 3 patients (four percent) anti-HBAg was detected. Thus, 6 patients with ACH (seven percent) had evidence of present or prior infection with the hepatitis B virus (HBV). HBAg was also detected in 7 of the patients with other liver diseases, 2 of the other hospital patients, and none of the healthy controls. Anti-HBAg was detected in 17 of the non-ACH subjects. These results indicate that neither persistent nor prior self-limited infection with HBV is a major factor in the pathogenesis of ACH in Australia.

Acute Disease↗
PubMed1975

Human isoferritins: organ specific iron and apoferritin distribution.

Ferritins from human liver, spleen, heart, pancreas and kidney were compared by electrophoresis and isoelectric focusing in polyacrylamide gels, by immunodiffusion against antisera to homologous and heterologous ferritin, and in some cases by their cyanogen bromide peptides. All ferritins appeared to consist of a single species on gel electrophoresis with the exception of heart ferritin which separated into two major components. Small differences in electrophoretic mobility were found in all tissue ferritins. By contrast, all tissue ferritins were found to consist of multiple forms when analysed by gel electrofocusing. At least five isoferritins were found in most tissues, several of which were common to most tissues. At least two were common to all tissues. Those ferritins which were most easily distinguishable electrophoretically, e.g. spleen and heart ferritin, showed the greatest differences on gel electrofocusing. The ferritin profile was characteristic of each organ and was reproducible both within individuals and between individual tissues. There were striking differences in the iron content of the various isoferritins within a tissue. Further, the iron content of isoferritins common to more than one tissue varied with the tissue of origin. Some isoferritins in several organs and all of the isoferritins in pancreas appeared to contain little, if any, iron. All five tissue ferritins contained antigenic determinants in common with liver ferritin. However, an additional antigenic determinant was found in liver ferritin which was not detectable in the ferritins from the other organs.

Apoferritins↗
PubMed1975

Guillain Barré syndrome during the pre-icteric phase of acute type B viral hepatitis.

A 54-year-old man presented with the Guillain Barré syndrome (GBS) during the pre-icteric phase of acute type B viral hepatitis. This neurological syndrome has been infrequently described in the clinical course of viral hepatitis but only once previously during the prodromal period. Deposition of circulating immune complexes of the HBsAg have been implicated in the pathogenesis of arthritis, nephritis and polyarteritis associated with type B viral hepatitis. Although the relationship of GBS to type B viral hepatitis is uncertain, a similar immunopathological mechanism may be involved.

Acute Disease↗
PubMed1975

The relationship of red cell membrane lipid content to red cell morphology and survival in patients with liver disease.

The relationship of red blood cell (RBC) membrane lipid content to RBC morphology and survival was studied in patients with liver diseases. An increase in RBC cholesterol and phospholipid was detected in most patients with hepatocellular disease or cholestatic jaundice but the alteration in RBC lipid content did not correlate with RBC survival. The main abnormality of RBC morphology observed was the presence of macrocytes and target cells. In a small proportion of patients (approximately 3%) with severe hepatocellular disease, significant numbers of severely deformed ("spur") cells were seen. In these patients haemolysis was moderately severe and the RBC lipid profile showed increased membrane cholesterol without a concomitant increase in phospholipids. It is concluded that only in patients with "spur" cell anaemia do the morphological alterations lead to premature removal of cells from the circulation. The cause of the shortened RBC survival in jaundiced patients without "spur" cells remains to be determined.

Adolescent↗
PubMed1975

Alterations in tissue ferritins in iron storage disorders.

Purified tissue ferritins isolated from Bantu subjects with gross haemosiderosis, from a patient with idiopathic haemochromatosis (HC) treated by phlebotomy, and from rats with experimental iron overload were studied in order to determine the significance of the abnormality previously demonstrated in tissue isoferritins in patients with IHC. The isoferrin profile of the tissues from the Bantu subjects and the iron-loaded rats showed a similar abnormality to that previously found in patients with untreated IHC--that is, an abnormally uniform distribution of iron-containing isoferritins with an increase in the more basic isoferritins and an apparent absence of the more acidic ones. In contrast, tissues from the patient with treated IHC, who was iron depleted at the time of death, showed the normal organ-specific isoferritin distribution. These findings strongly suggest that the abnormal distribution of tissue isoferritins in IHC is an acquired phenomenon and unlikely to be related to an underlying genetic defect in ferritin or iron metabolism.

Animals↗
PubMed1974

Specific immunodiagnosis of hepatocellular carcinoma by leucocyte adherence inhibition.

The leucocyte adherence inhibition test provides a rapid, reliable, and specific technique for the immunodiagnosis of primary hepatocellular carcinoma (malignant hepatoma). The patient's blood leucocytes are tested in vitro for cell-mediated immunity against tumour-associated antigens and the serum is tested for blocking factor which interferes with the immunological reaction. Specific reactivity of both leucocytes and serum was consistently detected in patients with malignant hepatoma, and negative reactions were obtained in other liver diseases including secondary tumours of the liver. The test has provided positive evidence for the presence of hepatoma when more conventional methods gave doubtful or negative results. A positive result preceded the clinical appearance of tumour by up to three years in two patients.

Adult↗
PubMed1974

Haemolysis in experimental cholestasis: possible role of erythrocyte sialic acid.

Because previous studies have suggested that red cell membrane sialic acid might be a determinant of survival in vivo, we examined the relationship between haemolysis, erythrocyte membrane sialic acid, and hepatic neuraminidase (sialidase) levels in experimental cholestatic jaundice in rats. Treatment of normal rat erythrocytes with neuraminidase in vitro resulted in a significant reduction in their survival in vivo and removal by the spleen. The degree of haemolysis was comparable to that previously found 12 days after bile duct ligation in rats. Bile duct ligation resulted in a significant increase in hepatic neuraminidase and a decrease in erythrocyte sialic acid. The findings are consistent with the hypothesis that one or more neuraminidases present in inreased amounts in the bile duct-ligated livers are responsible for the removal of sialic acid from circulating erythrocytes and subsequent removal of these cells in the spleen.

Animals↗