Biomedical subjects

J T Casper

Publications and source records attributed to J T Casper.

77 records · Page 5Linked to original sources

PubMed1977

Reactivity of human brain antiserum with neuroblastoma cells and nonreactivity with thymocytes and lymphoblasts.

Brain-associated antigens have been detected on human and mouse thymocytes. Also, murine neuroblasts and brain cells have common antigens. In this study we compared the reactivity of rabbit anti-human brain (HB) serum with neoplastic neuroblasts and normal and neoplastic lymphoid cells. The binding of HB antiserum to viable cells was assessed by immunofluorescence and an indirect radiolabeled antibody assay. HB antiserum reacted with greater than 80% of neuroblasts derived from two human cell lines and five children with neuroblastoma, but with less than 1% of human thymocytes, bone marrow lymphoid cells, and lymphocytic leukemia cells. HB antiserum also reacted with 5 to 10% of peripheral blood lymphocytes. Absorption with neuroblasts did not alt-r this reactivity. Rabbit antisera raised against normal human thymocytes and leukemic T-cells specifically bound to thymocytes but did not bind to neuroblasts. The reactivity of anti-HB serum against SK-N-SH neuroblasts was removed by absorption with HB, but not with human kidney or liver, or mouse and guinea pig brain. We conclude that human neuroblastoma cells possess cell-surface antigens that are present on HB. These antigens appear to be species specific and are not present on normal or malignant thymic cells. Conversely, thymus-associated antigens are not expressed on neuroblasts.

Antibodies↗

PubMed1976

A new method for studying splenic reticuloendothelial dysfunction in sickle cell disease patients and its clinical application: a brief report.

Differential interference contrast (DIC) microscopy (Nomarsky optics) readily demonstrates the formation of "pits" or crater-like depressions in red cell membranes of splenectomized individuals. Splenic reticuloendothelial dysfunction characteristic of many patients with sickle cell disease (SCD) can be demonstrated by technetium spleen scans, but this technique is expensive, requires injection of radioactive material into children, and is cumbersome to perform at regular intervals. However, pit formation in red cells, which also appears to reflect splenic dysfunction, can readily be quantitated in a finger-stick blood sample using DIC microscopy. In this study, the degree of red cell pitting was compared with results of technetium spleen scans and measurements of Howell-Jolly bodies in individuals with sickle cell disease. The average pitted cell percentage in the control population was 0.5% +/- 0.5 (range 0.0-2.6) and 30.5% +/- 13.9 in the SCD population (range 2.4-71.1) (less than 0.001). Of the individuals studied with SCD, 12 also had technetium (99mTc) sulfur colloid scans and measurements of Howell-Jolly bodies. The percentage of Howell-Jolly bodies was low and did not correlate well with the degree of splenic visualization. However, there was an excellent correlation between pit count and splenic dysfunction as measured by spleen scan. Determination of red cell pitting, therefore, appears to offer a simple means for clinical evaluation of splenic reticuloendothelial function in patients with SCD.

Adolescent↗

PubMed1976

Alternative complement pathway activity in sera from patients with sickle cell disease.

The low molecular weight cobra venom factor (CoVF) was used to activate the terminal sequence of the alternative complement pathway in thirty-one sera from patients with sickle cell disease (SCD). The SCD sera were compared with normal sera as a source of the alternative complement pathway factors C3 proactivator (C3PA) and C3PA convertase. These factors are required for formation of the enzymatically active CoVF-C3PA complex which is capable of cleaving C3 and thus initiating generation of the cytolytic C5b-9 complex. CoVF cofactor activity was significantly less than normal in SCD sera as measured in an indirect lysis assay, indicating reduced C3PA or C3PA convertase activity in these sera. Qualitative (immunoelectrophoresis) and quantitative (radial immunodiffusion) measurement of C3PA showed, however, that this protein is normal or elevated in SCD sera. Taken together, the reduced CoVF cofactor activity and normal or elevated C3PA in SCD sera suggests that sera from patients with sickle cell disease have reduced C3PA convertase activity.

Adolescent↗

PubMed1975

Reye syndrome. A correlated electron-microscopic, viral, and biochemical observation.

Liver biopsy specimens of two patients with Reye syndrome were examined for ultrastructural features, viral isolation, and urea-cycle enzyme activity. Concurrent presence of herpes-like virus and myxovirus/paramyxovirus was demonstrated by electron microscopy, and viral infections were confirmed by isolation or serologic tests. A concomitant hepatic ornithine transcarbamoylase deficiency was also noted. The pathogenesis in these instances seems to consist of an initial synergistic insult on the liver by mixed types of viruses and subsequent breakdown of urea cycle, Krebs cycle, and possible other hepatic functions. An exodus of glycogen granules into the hepatic spaces of Disse and sinusoids suggests that the viruses have injured the plasma membranes as well as the mitochondria of hepatocytes. Since Kapila et al reported similar disorders five years before Reye et al, the name of Kapila-Reye disease is suggested.

Adolescent↗

PubMedDate not supplied

Exchange transfusion in Reye's syndrome with saline-washed red blood cells.

Reye's syndrome (RS) consists of encephalopathy, fatty degeneration of viscera, and elevation of ammonia, certain amino acids, and liver enzymes in the blood. It is most characteristically a disease of children and has been considered to have a poor prognosis despite the use of various treatment regimens. Exchange transfusion (ET) with fresh blood (less than 24 hours old) for the removal of toxic metabolic byproducts in TS is a relatively recent development which appears to have improved the survival rates. However, because RS may occur in epidemic proportions at any time the demand for fresh blood can place an excessive stress on blood resources. We have, therefore, utilized saline-washed (to remove potentially toxic metabolites) red blood cells (RBC's) less than six days old, and fresh frozen citrate-phosphate-dextrose (CPD) plasma in treating this disorder. Nine patients in the Milwaukee community with severe encephalopathy secondary to RS were treated with ET. These patients collectively required 151 units of washed RBC's for 21 ET. Eight of nine patients survived without sequelae. Age of blood used did not correlate with the number of exchanges required or the eventual outcome. A continual computerized EEG in five patients provided objective evidence of the effectiveness of ET. We conclude that ET with saline-washed RBC's reconstituted with fresh frozen plasma (FFP) is a fast, safe, and effective means of treating patients with RS.

Brain Diseases↗