30,149 research outputs found

    The Federal Role in Promoting Health Information Technology

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    Outlines the need to expand adoption of health information technology to improve healthcare quality and efficiency; the financial, technical, and logistical challenges; and providers' concerns. Discusses federal policy options for addressing them

    Isoform- and Cell-Specific Function of Tyrosine Decarboxylase in the Drosophila Malpighian Tubule

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    The biogenic amine tyramine (TA) is a potent diuretic factor when applied to the Malpighian tubule (MT) of Drosophila melanogaster, stimulating both urine production and transepithelial chloride conductance. Isolated MTs can respond not only to TA but also to its precursor, tyrosine; this observation led to the proposal that MTs are able to synthesize TA from applied tyrosine through the action of the enzyme tyrosine decarboxylase (TDC). In the current study it is shown that the non-neuronal isoform of TDC, Tdc1, is expressed in the principal cells of the MT. A mutant allele of Tdc1, Tdc1f03311, was identified that reduced expression of the mature Tdc1 transcript by greater than 100-fold. MTs isolated from Tdc1f03311 homozygous flies showed no significant depolarization of their transepithelial potential (TEP) or diuresis in response to tyrosine while retaining normal sensitivity to TA. By contrast, a previously identified null mutant allele of the neuronal TDC isoform Tdc2 had no effect on either tyrosine or TA sensitivity. To determine in which cell type of the MT Tdc1 expression is required, flies were generated carrying a UAS-Tdc1 transgene and cell-type-specific Gal4 drivers on a Tdc1f03311 homozygous background. Rescue of Tdc1 expression in principal cells fully restored sensitivity to tyrosine whereas expression of Tdc1 in stellate cells had no rescuing effect. It is concluded that synthesis of TA by Tdc1 in the principal cells of the MT is required for physiological responses to tyrosine. TA synthesis in the MT is the first reported physiological role for Drosophila Tdc1

    Cloning of the Neurodegeneration Gene \u3cem\u3eDrop-Dead\u3c/em\u3e and Characterization of Additional Phenotypes of its Mutation

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    Mutations in the Drosophila gene drop-dead (drd) result in early adult lethality and neurodegeneration, but the molecular identity of the drd gene and its mechanism of action are not known. This paper describes the characterization of a new X-linked recessive adult-lethal mutation, originally called lot\u27s wife (lwf1) but subsequently identified as an allele of drd (drdlwf); drdlwf mutants die within two weeks of eclosion. Through mapping and complementation, the drd gene has been identified as CG33968, which encodes a putative integral membrane protein of unknown function. The drdlwf allele is associated with a nonsense mutation that eliminates nearly 80% of the CG33968 gene product; mutations in the same gene were also found in two previously described drd alleles. Characterization of drdlwf flies revealed additional phenotypes of drd, most notably, defects in food processing by the digestive system and in oogenesis. Mutant flies store significantly more food in their crops and defecate less than wild-type flies, suggesting that normal transfer of ingested food from the crop into the midgut is dependent upon the DRD gene product. The defect in oogenesis results in the sterility of homozygous mutant females and is associated with a reduction in the number of vitellogenic egg chambers. The disruption in vitellogenesis is far more severe than that seen in starved flies and so is unlikely to be a secondary consequence of the digestive phenotype. This study demonstrates that mutation of the drd gene CG33968 results in a complex phenotype affecting multiple physiological systems within the fly

    The conservative treatment of thromboangiitis obiterans

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    Thesis (M.D.)—Boston Universit

    Committed to Safety: Ten Case Studies on Reducing Harm to Patients

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    Presents case studies of healthcare organizations, clinical teams, and learning collaborations to illustrate successful innovations for improving patient safety nationwide. Includes actions taken, results achieved, lessons learned, and recommendations

    Pressure Distribution on Joukowski Wings

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    The hydrodynamics and mathematical models as applied to the potential flow about a Joukowski wing are presented
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