1,613 research outputs found

    Organizing the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST): National Institutes of Health, Health Care Financing Administration, and industry funding

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    The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is a prospective, randomized, multicenter clinical trial of carotid endarterectomy (CEA) versus carotid artery stenting (CAS) as prevention for stroke in patients with symptomatic stenosis greater than or equal to 50%. CREST is sponsored by the US National Institute of Neurological Disorders and Stroke (NINDS) of the US National Institutes of Health (NIH), with additional support by a device manufacturer, and will provide data to the US Food and Drug Administration (FDA) for evaluation of a stent device. Because of budget constraints for CREST, Health Care Financing Administration (HCFA) reimbursement for hospital costs incurred by CREST patients will be essential. The involvement of academic scientists, industry, and three separate government agencies (NIH, FDA, HCFA) has presented many challenges in conducting the trial. A review of the pathways followed to meet these challenges may be helpful to others seeking to facilitate sharing of the costs and burdens of conducting innovative clinical research

    The costs of respiratory illnesses arising from Florida gulf coast Karenia brevis blooms

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    This is the final version of the article. Available from NIEHS via the DOI in this recordBACKGROUND: Algal blooms of Karenia brevis, a harmful marine algae, occur almost annually off the west coast of Florida. At high concentrations, K. brevis blooms can cause harm through the release of potent toxins, known as brevetoxins, to the atmosphere. Epidemiologic studies suggest that aerosolized brevetoxins are linked to respiratory illnesses in humans. OBJECTIVES: We hypothesized a relationship between K. brevis blooms and respiratory illness visits to hospital emergency departments (EDs) while controlling for environmental factors, disease, and tourism. We sought to use this relationship to estimate the costs of illness associated with aerosolized brevetoxins. METHODS: We developed a statistical exposure-response model to express hypotheses about the relationship between respiratory illnesses and bloom events. We estimated the model with data on ED visits, K. brevis cell densities, and measures of pollen, pollutants, respiratory disease, and intra-annual population changes. RESULTS: We found that lagged K. brevis cell counts, low air temperatures, influenza outbreaks, high pollen counts, and tourist visits helped explain the number of respiratory-specific ED diagnoses. The capitalized estimated marginal costs of illness for ED respiratory illnesses associated with K. brevis blooms in Sarasota County, Florida, alone ranged from 0.5to0.5 to 4 million, depending on bloom severity. CONCLUSIONS: Blooms of K. brevis lead to significant economic impacts. The costs of illness of ED visits are a conservative estimate of the total economic impacts. It will become increasingly necessary to understand the scale of the economic losses associated with K. brevis blooms to make rational choices about appropriate mitigation.This research was sponsored by the Florida Fish & Wildlife Conservation Commission (07182) and the Departments of Environmental Protection and Health; the U.S. Centers for Disease Control and Prevention; the Center for Oceans and Human Health at the Woods Hole Oceanographic Institution [National Science Foundation (NSF) OCE-0430724; National Institute of Environmental Health Sciences (NIEHS) P50 ES012742]; the Ocean and Human Health Center at the University of Miami Rosenstiel School (NSF 0CE0432368; NIEHS 1 P50 ES12736); and the NIEHS (PO1 ES 10594)

    Measurement of the hadronic photon structure function F_{2}^{Ī³} at LEP2

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    The hadronic structure function of the photon F_{2}^{Ī³} (x, QĀ²) is measured as a function of Bjorken x and of the photon virtuality QĀ² using deep-inelastic scattering data taken by the OPAL detector at LEP at eāŗeā» centre-of-mass energies from 183 to 209 GeV. Previous OPAL measurements of the x dependence of F_{2}^{Ī³} are extended to an average QĀ² of 怈QĀ²ć€‰=780 GeVĀ² using data in the kinematic range 0.15<x<0.98. The QĀ² evolution of F_{2}^{Ī³} is studied for 12.1<怈QĀ²ć€‰<780 GeVĀ² using three ranges of x. As predicted by QCD, the data show positive scaling violations in F_{2}^{Ī³} with F_{2}^{Ī³} (QĀ²)/Ī± = (0.08Ā±0.02āŗā°Ā·ā°āµ_ā‚€.ā‚€ā‚ƒ) + (0.13Ā±0.01āŗā°Ā·ā°Ā¹_ā‚€.ā‚€ā‚) lnQĀ², where QĀ² is in GeVĀ², for the central x region 0.10ā€“0.60. Several parameterisations of F_{2}^{Ī³} are in qualitative agreement with the measurements whereas the quark-parton model prediction fails to describe the data

    Imagable 4T1 model for the study of late stage breast cancer

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    <p>Abstract</p> <p>Background</p> <p>The 4T1 mouse mammary tumor cell line is one of only a few breast cancer models with the capacity to metastasize efficiently to sites affected in human breast cancer. Here we describe two 4T1 cell lines modified to facilitate analysis of tumor growth and metastasis and evaluation of gene function <it>in vivo</it>. New information regarding the involvement of innate and acquired immunity in metastasis and other characteristics of the model relevant to its use in the study of late stage breast cancer are reported.</p> <p>Methods</p> <p>The lines were engineered for stable expression of firefly luciferase to allow tracking and quantitation of the cells <it>in vivo</it>. Biophotonic imaging was used to characterize growth and metastasis of the lines <it>in vivo </it>and an improved gene expression approach was used to characterize the basis for the metastatic phenotype that was observed.</p> <p>Results</p> <p>Growth of cells at the primary site was biphasic with metastasis detected during the second growth phase 5ā€“6 weeks after introduction of the cells. Regression of growth, which occurred in weeks 3ā€“4, was associated with extensive necrosis and infiltration of leukocytes. Biphasic tumor growth did not occur in BALB/c SCID mice indicating involvement of an acquired immune response in the effect. Hematopoiesis in spleen and liver and elevated levels of circulating leukocytes were observed at week 2 and increased progressively until death at week 6ā€“8. Gene expression analysis revealed an association of several secreted factors including colony stimulatory factors, cytokines and chemokines, acute phase proteins, angiogenesis factors and ECM modifying proteins with the 4T1 metastatic phenotype. Signaling pathways likely to be responsible for production of these factors were also identified.</p> <p>Conclusion</p> <p>The production of factors that stimulate angiogenesis and ECM modification and induce hematopoiesis, recruitment and activation of leukocytes suggest that 4T1 tumor cells play a more direct role than previously appreciated in orchestrating changes in the tumor environment conducive to tumor cell dissemination and metastasis. The new cell lines will greatly facilitate the study of late stage breast and preclinical assessment of cancer drugs and other therapeutics particularly those targeting immune system effects on tumor metastasis.</p

    Measurement of the charm structure function F_{2,c)^{Ī³} of the photon at LEP

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    The production of charm quarks is studied in deep-inelastic electronā€“photon scattering using data recorded by the OPAL detector at LEP at nominal eāŗeā» centre-of-mass energies from 183 to 209 GeV. The charm quarks have been identified by full reconstruction of charged D* mesons using their decays into Dā°Ļ€ with the Dā° observed in two decay modes with charged particle final states, KĻ€ and KĻ€Ļ€Ļ€. The cross-section Ļƒ^{D*} for production of charged D* in the reaction eāŗeā»ā†’eāŗeā»D*Ī§ is measured in a restricted kinematical region using two bins in Bjorken x, 0.00140.1 the perturbative QCD calculation at next-to-leading order agrees perfectly with the measured cross-section. For x<0.1 the measured cross-section is 43.8Ā±14.3Ā±6.3Ā±2.8 pb with a next-to-leading order prediction of 17.0āŗĀ²Ā·ā¹_ā‚‚.ā‚ƒ pb

    Measurement of triple gauge boson couplings from WāŗWā» production at LEP energies up to 189 GeV

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    A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity of 183 pbā»Ā¹. After combining with our previous measurements at centre-of-mass energies of 161ā€“183 GeV we obtain Īŗ = 0.97_{-0.16}^{+0.20}, g_{1}^{z} = 0.991_{-0.057}^{+0.060} and Ī» = -0.110_{-0.055}^{+0.058}, where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to their Standard Model values. These results are consistent with the Standard Model expectations
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