Ultrastructure of muscle spindles in C57BL/6Jdy 2J/dy 2J dystrophic mice

Summary The sensory organs of skeletal muscles, the muscle spindles, were examined using electron microscopy indy ^2J/dy ^2J dystrophic mice. Despite widespread damage to the extrafusal (skeletomotor) fibres the intrafusal (spindle) fibres appeared normal and seemed resistant to the aetiological factors for murine dystrophy.This work was supported by grants from the Medical Research Council and the Science Research Council of Great Britain.     

Pigment in the spleen of C57BL/10ScSn and related mice

Summary Pigment present in the spleen of C57BL and related mice, after the stress of experimental procedures, was shown to be melanin.Acknowledgments. We would like to thank Dr. J. Hewson, British Industrial Biological Research Association, Carshalton, Surrey, for the help and advice.     

Ultrastructure of muscle spindles in C57BL/6J dy2J/dy2J dystrophic mice.

The sensory organs of skeletal muscles, the muscle spindles, were examined using electron microscopy in dy2J/dy2J dystrophic mice. Despite widespread damage to the extrafusal (skeletomotor) fibres the intrafusal (spindle) fibres appeared normal and seemed resistant to the aetiological factors for murine dystrophy.     

The replication of a xenotropic murine C type virus in some mammalian cells. Definition of a specific antigen]

The use of our mink cell line maintained in vitro infected with the murine xenotropic AT 124 virus, and that of a (W/Fu x bn) f1 rat anti-124 serum allow us to define a new cell surface antigen specific of murine xenotropic type C viruses.     

Glutamate oxaloacetate transaminase (GOT) in thedy 2J genotypes of C57BL/6J mice: Possible involvement of regulatory defect in muscular dystrophy

Summary The GOT mitochondrial isozyme of heterozygote and homozygote muscular dystrophy (dy^2J) genotypes is affected during development prior to the expression of dystrophy in homozygotes, dy^2J/dy^2J.This research was supported by a Natural Science and Engineering Research Council Canada grant to S.M.S.     

Dystrophic mutation (dy2J) affecting regulation of lactate dehydrogenase (LDH) and pyruvate kinase (PK) in C57BL/6J mice

Summary The genotype difference (dystrophic vs nondystrophic) in the LDH isozymes is observed in kidney. These differences are evident only at birth and at early developmental stages (before the expression of dystrophic symptoms). The tissue specific genotype differences for PK are limited to the thigh muscle (M form) and heart (L form), after the onset of the condition. These differences may reflect the pleiotropic effect of the dy^2J locus during the temporal regulation of these and other enzymes implicated in muscular dystrophy (MD).This research was financed by a Natural Sciences and Engineering Research Council Canada grant to S.M.S.     

Response of an undifferentiated and nullipotential cell line derived from an A/Heston mouse teratocarcinoma to infection with type C ecotropic murine viruses]

The PCC6 cell line, derived from an A/Heston Mouse Teratocarcinoma, and composed of nullipotential embryonic carcinoma cells (ECC), is completely resistant to infection with type C murine ecotropic viruses. It reacts as other cell lines previously studied which are derived from a 129 Mouse teratocarcinoma and composed of multipotential ECC.     

Effect of sodium butyrate on the interferon sensitivity of normal or cells transformed by murine sarcoma virus]

Sodium butyrate enhances the sensitivity of MSV transformed murine cells to interferon, but does not influence the response of normal cells. Sodium butyrate might act in transformed cells by restoring the different elements of the cytoskeletal system.     

Study of gangliosides in normal (C57B1/6J) and quaking mice. Presence and characterization of a labile ganglioside in alkaline solution]

In the adult Quaking mutant, there is an increase in some polysialogangliosides (GT1 and Gq) and a 50% decrease in BM1 content. Thus, the latter ganglioside, which is a constituent of mature myelin, could be linked to one of the late steps of the myelination process. A novel ganglioside ALG1, which appears during the postnatal development of brain, has been isolated and purified; it contains an alkali labile linkage and after alkaline treatment yields GT1b. Comparison between normal Mice and Quaking mutants does not show any significant quantitative differences, under our conditions. At the stage at which it appears, it could be linked to steps of brain maturation other than myelimation.     

Proliferation of spleen cells from mice infected with friend virus in the spleens of unirradiated and irradiated mice

Résumé Quand des cellules spléniques de souris CBA/HT₆T₆ infectées par le virus de Friend sont injectées à des souris CBA/H normales, les rates des receveurs s'hypertrophient au cours de la semaine suivante. Une analyse chromosomale montra que toutes les cellules en division provenaient de l'hôte, suggérant que la splénomégalie fait suite à la libération du virus des cellules injectées.     

Stimulation of SV40 virus replication in Chinese hamster kidney cells by treatment of the cells with mitomycin C]

The production of virions by Chinese hamster kidney cells infected with SV 40 DNA is increased 10 to 100 fold by mitomycin C treatment. This observation has been confirmed for different cell clones. The optimum concentration of mitomycin C has been determined.     

Sedimentation behaviour of the avian tumor virus group specific antigen from the BAI strain,a virus associated myeloblast cell

Zusammenfassung BAI Virus Stamm A und mit diesem Virus infizierte Myeloblastzellen haben ein gemeinsames, gruppenspezifisches Antigen. Das aus dem Virus abgetrennte Antigen wurde mit dem aus den Zellen herausgelösten im Saccharose-Dichtegradienten verglichen. Sowohl für das Virus wie für das Zellantigen wurde der gleiche Sedimentationswert erhalten.

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This work was done while the author was at Duke University Medical Center, Durham (N.C., USA)     

Release of growth hormone from somatotropin producing cells of hepatectomized mice without the participation of the Golgi complex

Resumen El reticulo endoplasmico de las celulas somatotropas del raton hepatectomizado se encuentra muy dilatado y contiene material denso en el interior de sus cisternas. Estas se observan frecuentemente en contacto con la membrana celular en zonas en que ésta y el intersticio presentan un aumento de densidad. Se sugiere un mecanismo directo de secreción de la hormona sintetizada en exceso en el reticulo endoplasmico, sin pasar previamente por el complejo de Golgi.

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This investigation was supported by a grant from the Comision de Investigacion Cientifica de la Universidad Nacional de La Plata. Thanks are due to the members of the technical staff of the Institute for their technical assistance.