Animal model of Gaucher's disease from targeted disruption of the mouse glucocerebrosidase gene.

Gaucher's disease is the most prevalent lysosomal storage disorder in humans and results from an autosomally inherited deficiency of the enzyme glucocerebrosidase (beta-D-glucosyl-N-acylsphingosine glucohydrolase), which is responsible for degrading the sphingolipid glucocerebroside. An animal model for Gaucher's disease would be important for investigating its phenotypic diversity and pathogenesis and for evaluating therapeutic approaches. A naturally occurring canine model has been reported but not propagated. Attempts to mimic the disease in animals by inhibiting glucocerebrosidase have been inadequate. Here we generate an animal model for Gaucher's disease by creating a null allele in embryonic stem cells through gene targeting and using these genetically modified cells to establish a mouse strain carrying the mutation. Mice homozygous for this mutation have less than 4% of normal glucocerebrosidase activity, die within twenty-four hours of birth and store glucocerebroside in lysosomes of cells of the reticuloendothelial system.     

Conversion of testosterone to androstenedione by liver homogenates of testicular feminized mice

Summary Liver homogenates of testicular feminized (Tfm) mice carrying the protective (o^hv) gene were found to be less capable of converting testosterone to androstenedione than Tfm without the protective gene.This work was supported by the Medical Research Council of Canada, No. MT 4192 and Ortho Pharmaceutical Company.     

Interaction between the soluble and particulate neuraminidases of chick liver

Summary The sum of the neuraminidase activities found in the isolated soluble and particulate fractions of chick liver was considerably higher than that observed in the cytoplasmic extract from which these fractions were obtained. Addition of increasing amounts of particulate neuraminidase to a constant amount of the soluble preparation resulted in a progressive loss of enzyme activity.This investigation was supported in part by U. S. Public Health Service Grant NS09176 from the National Institutes of Health.     

Manifestation of anaphylaxis to egg albumen in the lizard, Calotes versicolor.

Anaphylaxis was induced in the lizard, Calotes versicolor by egg albumen. The symptoms were similar to those found in other species. The maximum mortality occurred 14 days after sensitization and the reaction was specific. Splenectomy before sensitization abrogated the manifestations of anaphylaxis.     

Sequence and functional expression of the GABA A receptor shows a ligand-gated receptor super-family

Amino-acid sequences derived from complementary DNAs encoding the alpha- and beta-subunits of the GABA/benzodiazepine receptor from bovine brain show homology with other ligand-gated receptor subunits, suggesting that there is a super-family of ion-channel-containing receptors. Co-expression of the in vitro-generated alpha-subunit and beta-subunit RNAs in Xenopus oocytes produces a functional receptor and ion channel with the pharmacological properties characteristic of the GABAA receptor.