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Biomedical subjects

W C Schneider

Publications and source records attributed to W C Schneider.

14 recordsLinked to original sources
PubMed1991

An Integrated International Aerospace Medical Information System.

An Integrated International Aerospace Medical Information System (IIASMIS) is proposed. Such a system is needed to allow all appropriate resources to be brought to bear on the medical problems that must be solved for safe extended manned missions. Existing medical data bases are reviewed. The suggested approach involves the formation of an international working group that would determine the scope of the problem, identify the real needs, and design the top-level architecture of the system. Participants would develop national data bases independently. A prototype system would be developed and evaluated; upon satisfactory operation, it would be expanded to include all active partners.

Aerospace Medicine↗
PubMed1982

Molecular basis for increased synthesis of albumin in rat liver after thioacetamide administration.

Administration of thioacetamide to rats for 4 days has been shown previously to increase the activity of liver messenger RNA (mRNA) and to disproportionately increase the activity of albumin mRNA in the wheat germ translation system. We have explored the possibility that administration of thioacetamide quantitatively alters the transcription of rat liver unique DNA. Nucleic acid hybridization between the radioactive rat liver unique DNA and RNA from untreated as well as 4-day thioacetamide-treated rat liver indicates that the normal extent of transcription is not altered by the drug treatment. We also investigated the possibility that thioacetamide treatment increases the level of mRNA in general or of albumin mRNA in particular. Albumin mRNA, which is th most abundantly represented population in rat liver cytoplasmic mRNA, was further enriched by sucrose gradient fractionation of the liver mRNA. Synthesis of complementary DNA (cDNA) and then use of the strategy of limited hybridization yielded the cDNA corresponding to albumin mRNA. Hybridization of the fractionated cDNA with mRNA from untreated livers as well as from livers with increasing days of treatment shows no change in the level of albumin mRNA. The results indicate that drug treatment induces the augmented synthesis of albumin by disproportionately increasing the translational activity of albumin mRNA. Quantitation of gene dosage by comparison of hybridization kinetics of fractionated cDNA and unique [3H]DNA with total rat cellular DNA indicates that there are not more than two copies of the albumin gene present in the rat genome.

Acetamides↗
PubMed1978

Increased activity of rat liver messenger RNA and of albumin messenger RNA modulated by thioacetamide.

Administration of thioacetamide to rats was found to increase the activity of liver messenger RNA in the wheat germ protein synthesis assay. The synthesis of total protein was increased about 2.5-fold after 4 days of treatment. The treatment was associated with an increase in the relative quantity of polyadenylic acid-containing RNA. Immunoprecipitation studies showed that albumin synthesis directed by the messenger RNA was increased disproportionately, reaching a level 5 to 6 times the control after 4 days of thioacetamide administration.

Acetamides↗
PubMed1975

Association of DNA with melanin granules.

Melanin granules were isolated from the Cloudman S91 mouse melanoma and from Amphiuma liver in highly purified form, as judged by electron microscopy and the lack of a mitochondrial enzyme marker. The granules from both tissues contained small amounts of DNA (less than or equal to 1% of the cell content) that was distinguished from nuclear DNA by the broadness of its buoyant density band in cesium chloride, by its sedimentation rate, and by a two-phased melting curve. The melanosome DNA could not be distinguished from nuclear and mitochondrial DNA by the amount of tritiated thymidine incorporated. The results are discussed and the suggestion made that the melanin DNA may provide the information that led to the production of the granules.

Animals↗