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Biomedical subjects

W A Hook

Publications and source records attributed to W A Hook.

31 records · Page 2Linked to original sources
PubMed1972

Further characterization of a factor from endotoxin-treated serum which releases histamine and heparin from mast cells.

Upon incubation of hamster serum with bacterial endotoxin, a factor is produced which releases histamine and heparin from hamster mast cells and increases capillary permeability in guinea pig skin. The major histamine-releasing activity derived from hamster serum was characterized by gel filtration, found to have a molecular weight of approximately 60,000, and shown by electrophoresis to migrate with alpha-2- or beta-1-globulins. The ability to increase vascular permeability was not reversed by antihistamine. On the basis of these properties, the histamine-liberating factor generated by endotoxin in hamster serum differed significantly from known anaphylatoxins.

Animals↗
PubMed1970

Immunosuppression by murine sarcoma virus (Moloney).

Infection of mice with the murine sarcoma virus (Moloney) markedly suppressed the humoral antibody response to sheep erythrocyte antigen injected 10 days after infection, when tumor size was maximal, and on day 26, when primary tumors had partially regressed. Humoral antibody response was also inhibited when antigen was injected at the time secondary tumors and metastases were evident. No significant suppression of humoral antibody was seen when mice were injected with sheep erythrocyte antigen 5 days after virus infection. Inhibition of the cellular immune response of murine sarcoma virus (Moloney)-infected mice, as measured by the increased survival time of skin grafts, was also determined. Mice that were infected 5 days prior to grafting demonstrated prolonged survival of grafts, suggesting a suppression of cellular immunity. These mice had a graft survival time 14 days greater than noninfected controls. No significant prolongation of graft survival was seen in mice grafted at the times of maximum primary tumor growth, of primary tumor regression, or when secondary tumors had appeared.

Journal Article↗
PubMed1970

Histamine-releasing factor generated by the interaction of endotoxin with hamster serum.

Injection of hamsters with endotoxin (LPS) resulted, 4 to 14 days later, in a marked decline in the mast cell count and in a reduction of the available histamine content of cells obtained by peritoneal lavage. The release of histamine from isolated peritoneal hamster mast cells in vitro could be achieved by incubating LPS with fresh hamster serum followed by addition of mast cells and a second incubation. The generation of a histamine-releasing factor from serum could be inhibited by conditions which inhibit the consumption of complement by LPS. Several substances could be substituted for LPS in the generation of histamine-releasing activity including heat-aggregated human gamma globulin, zymosan, purified cobra venom factor, and washed antigen-antibody precipitates. With all of these agents, the generation of a histamine-releasing substance from hamster serum was accompanied by consumption of hemolytic complement. The results suggest that LPS indirectly leads to the release of histamine from mast cells as a result of interactions with the complement system.

Journal Article↗
PubMed1969

Immunological properties of Friend virus from mouse spleen obtained by gel filtration.

Gel filtration, with Sephadex G-200, was utilized to obtain Friend virus (FV) from infected spleen homogenate. Highly infectious and immunologically active material was eluted as a large initial protein peak, whereas hemoglobin and other noninfectious materials were found in two subsequent peaks. Fractions that made up the first peak were reactive in serological tests with antiserum towards FV. Formalinized fractions from the first peak, when combined with Freund's complete adjuvant, were able to protect mice against subsequent FV challenge. Further purification of antigen was carried out by sucrose gradient ultracentrifugation.

Animals↗
PubMed1967

Soluble antigens for immunofluorescence detection of Histoplasma capsulatum antibodies.

Soluble antigens from Histoplasma capsulatum in the mycelial and yeast phase were purified by gel filtration, fixed onto paper discs, and employed in an indirect immunofluorescence procedure to detect antibody in sera from individuals infected with H. capsulatum. The elution patterns of crude histoplasmin passed through Sephadex G-200 revealed two minor peaks of protein showing immunofluorescence, complement fixing, and precipitating-antigen activity. A large peak containing the pigment and other low molecular weight materials showed no serological activity. A polysaccharide antigen obtained from fragmented, deproteinized yeast-phase cells was reactive in the fluorescent-antibody test but showed no antigen activity in complement fixation or precipitin tests. Although certain sera from culturally proven cases of blastomycosis, coccidioidomycosis, and cryptococcosis reacted with the purified Histoplasma antigens, preliminary evaluation indicated that the immunofluorescence technique may be of value as a screening procedure for the serodiagnosis of histoplasmosis.

Antibodies↗
PubMed1967

Friend Leukemogenic Virus-neutralizing Antibody from Mouse Ascitic Fluid.

Ascitic fluid antibody produced in C57/B1 mice immunized with Friend leukemogenic virus exhibited potent neutralizing activity. In vitro neutralization tests revealed that a mean neutralization index of 3.0 was achieved, and it was shown by sucrose gradient ultracentrifugation that this antibody resembled the 7S type. A mean yield of 6.7 ml of fluid per mouse per weekly paracentesis was obtained over an 8-week period. The ascitic fluid antibody to Friend virus was also active in vivo. Mice given antibody 3, 5, 7, and 9 days after infection with Friend virus did not develop the splenomegaly characteristic of Friend disease.

Journal Article↗