Aldehyde dehydrogenase isozymes in rat hepatoma-mouse fibroblast hybrids

A study of aldehyde dehydrogenase in rat hepatoma cells and rat hepatoma-mouse fibroblast hybrids revealed that the hepatoma cells had activity comparable to that found in whole rat liver and that the enzyme activity was suppressed in early hybrids and reappeared following chromosome loss. Starch gel electrophoresis and heat inactivation studies showed that a new form of enzyme was produced in the hybrids, possibly a heteropolymorphic combination between the HTC enzyme and a previously repressed mouse form. Staining methods for starch gel electrophoresis and histochemical detection of aldehyde dehydrogenase are described.This work was supported by grants from the Damon Runyon Foundation (DRG 1088s) and the Public Health Service (1-R01-Ca 12310-02).     

Correlation Between Degradation of Bacteriophage T2 Deoxyribonucleic Acid and the Resistance of Escherichia coli to Infection

The ability of certain strains of Escherichia coli to degrade T2 deoxyribonucleic acid to acid-soluble fragments is correlated with their high capacity to survive T2 infection.     

Androgen sulphate formation in male and female mice

1. After the administration of large doses of androsterone, epiandrosterone, dehydroepiandrosterone and testosterone to mice, females excreted more of the dose conjugated with sulphuric acid than did males. 2. Liver slices from female mice conjugated androgens with sulphuric acid to a greater extent than did slices from males. 3. Sulphotransferase preparations from livers of female rats and mice catalysed the formation of dehydroepiandrosterone sulphate at a faster rate than preparations from livers of the male animals. 4. A possible explanation for the observed sex differences is discussed.     

Purification and characterization of bovine aorta ribonucleases

1. Two ribonucleases (aorta ribonuclease I and aorta ribonuclease II) from bovine aorta were purified 4611-fold and 667-fold respectively. Ethanolic precipitation, acid extraction, isoionic precipitation at pH3.5 and Bio-Rex 70 column chromatography were the methods employed. 2. Aorta ribonuclease I exhibited no deoxyribonuclease or alkaline phosphatase activity. 3. Aorta ribonuclease I appeared to be homogeneous when subjected to discontinuous gel electrophoresis. 4. Aorta ribonuclease II exhibited the same properties as aorta ribonuclease previously isolated. 5. The activities of the aorta ribonucleases and pancreatic ribonuclease on homopolymers and dinucleoside phosphates were compared. 6. Aorta ribonuclease I exhibited optimum pH7.5 and, under the assay conditions used, optimum temperature 60 degrees .     

Detection of Lymphocytic Choriomeningitis Virus Antibody in Murine Sera by Immunofluorescence

An immunofluorescence technique developed for detection of antibody in murine sera to lymphocyitc choriomeningitis virus is described.