322 research outputs found

    Validation of the severity index by cardiac catheterization and Doppler echocardiography in patients with aortic sclerosis and stenosis

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    The severity index is a new echocardiographic measure that is thought to be an accurate indicator of aortic leaflet pathology in patients with AS. However, it has not been validated against cardiac catheterization or Doppler echocardiographic measures of AS severity nor has it been applied to patients with aortic sclerosis. The purposes of this study were to compare the severity index to invasive hemodynamics and Doppler echocardiography across the spectrum of calcific aortic valve disease, including aortic sclerosis and AS. 48 patients with aortic sclerosis and AS undergoing echocardiography and cardiac catheterization comprised the study population. The aortic valve leaflets were assessed for mobility (scale 1 to 6) and calcification (scale 1 to 4) and the severity index was calculated as the sum of the mobility and calcification scores according to the methods of Bahler et al. The severity index increased with increasing severity of aortic valve disease; the severity indices for patients with aortic sclerosis, mild to moderate AS and severe AS were 3.38 ± 1.06, 6.45 ± 2.16 and 8.38 ± 1.41, respectively. The aortic jet velocity by echocardiography and the square root of the maximum aortic valve gradient by cardiac catheterization correlated well with the severity index (r = 0.84, p < 0.0001; r = 0.84, p < 0.0001, respectively). These results confirm that the severity index correlates with hemodynamic severity of aortic valve disease and may prove to be a useful measure in patients with aortic sclerosis and AS

    The Pioneer Anomaly

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    Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living Reviews in Relativit

    Coxiella burnetii Phagocytosis Is Regulated by GTPases of the Rho Family and the RhoA Effectors mDia1 and ROCK

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    The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the hostÂŽs cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C. burnetii by phagocytic and non-phagocytic cells. The internalization of C. burnetii into HeLa and RAW cells was significantly inhibited when the cells were treated with Clostridium difficile Toxin B which irreversibly inactivates members of the Rho family. In addition, the internalization was reduced in HeLa cells that overexpressed the dominant negative mutants of RhoA, Rac1 or Cdc42 or that were knocked down for the Rho GTPases. The pharmacological inhibition or the knocking down of ROCK diminished bacterium internalization. Moreover, C. burnetii was less efficiently internalized in HeLa cells overexpressing mDia1-N1, a dominant negative mutant of mDia1, while the overexpression of the constitutively active mutant mDia1-ΔN3 increased bacteria uptake. Interestingly, when HeLa and RAW cells were infected, RhoA, Rac1 and mDia1 were recruited to membrane cell fractions. Our results suggest that the GTPases of the Rho family play an important role in C. burnetii phagocytosis in both HeLa and RAW cells. Additionally, we present evidence that ROCK and mDia1, which are downstream effectors of RhoA, are involved in that processFil: Salinas Ojeda, Romina Paola. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Ortiz Flores, Rodolfo Matias. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Distel, JesĂșs SebastiĂĄn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Aguilera, Milton Osmar. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Beron, Walter. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas MĂ©dicas. Instituto de HistologĂ­a y EmbriologĂ­a de Mendoza Dr. Mario H. Burgos; Argentin

    Influence of mycotoxin zearalenone and its derivatives (alpha and beta zearalenol) on apoptosis and proliferation of cultured granulosa cells from equine ovaries

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    BACKGROUND: The mycotoxin zearalenone (ZEA) and its derivatives, alpha and beta-zearalenol (alpha and beta-ZOL), synthesized by genera Fusarium, often occur as contaminants in cereal grains and animal feeds. The importance of ZEA on reproductive disorders is well known in domestic animals species, particularly in swine and cattle. In the horse, limited data are available to date on the influence of dietary exposure to ZEA on reproductive health and on its in vitro effects on reproductive cells. The aim of this study was to evaluate the effects of ZEA and its derivatives, alpha and beta-ZOL, on granulosa cells (GCs) from the ovaries of cycling mares. METHODS: The cell proliferation was evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test after 3 days exposure at different concentrations of ZEA and its derivatives (from 1 × 10-7 to 0.1 microM). The apoptosis induction was evaluated after 1 day exposure, by DNA analysis using flow cytometry. RESULTS: An increase in cell proliferation with respect to the control was observed in the presence of ZEA at 1 × 10-3 and 1 × 10-4 microM and apoptosis was induced by all mycotoxins at different concentrations. CONCLUSION: The simultaneous presence of apoptosis and proliferation in GC cultures treated with zearalenones could indicate that these mycotoxins could be effective in inducing follicular atresia. These effects of zearalenones may result from both direct interaction with oestrogen-receptors as well as interaction with the enzymes 3alpha (beta)-hydroxysteroid dehydrogenase (HSD), involved in the synthesis and metabolism of endogenous steroid hormones. These cellular disturbances, described for the first time in equine GCs cultured in vitro, could be hypothesized as referred to reproductive failures of unknown ethiology in the mare

    Exploring Definitions and Predictors of Severe Asthma Clinical Remission Post-Biologic in Adults.

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    RATIONALE: There is no consensus on criteria to include in an asthma remission definition in real-life. Factors associated with achieving remission post-biologic-initiation remain poorly understood. OBJECTIVES: To quantify the proportion of adults with severe asthma achieving multi-domain-defined remission post-biologic-initiation and identify pre-biologic characteristics associated with achieving remission which may be used to predict it. METHODS: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1-year pre- and post-biologic-initiation. A priori-defined remission cut-offs were: 0 exacerbations/year, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted forced expiratory volume in one second ≄80%. Remission was defined using 2 (exacerbations + LTOCS), 3 (+control or +lung function) and 4 of these domains. The association between pre-biologic characteristics and post-biologic remission was assessed by multivariable analysis. MEASUREMENTS AND MAIN RESULTS: 50.2%, 33.5%, 25.8% and 20.3% of patients met criteria for 2, 3 (+control), 3 (+lung function) and 4-domain-remission, respectively. The odds of achieving 4-domain remission decreased by 15% for every additional 10-years asthma duration (odds ratio: 0.85; 95% CI: 0.73, 1.00). The odds of remission increased in those with fewer exacerbations/year, lower LTOCS daily dose, better control and better lung function pre-biologic-initiation. CONCLUSIONS: One in 5 patients achieved 4-domain remission within 1-year of biologic-initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission post-biologic, indicating that biologic treatment should not be delayed if remission is the goal. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Evaluation of interventions on road traffic injuries in Peru: a qualitative approach

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    <p>Abstract</p> <p>Background</p> <p>Evaluation of interventions on road traffic injuries (RTI) going beyond the assessment of impact to include factors underlying success or failure is an important complement to standard impact evaluations. We report here how we used a qualitative approach to assess current interventions implemented to reduce RTIs in Peru.</p> <p>Methods</p> <p>We performed in-depth interviews with policymakers and technical officers involved in the implementation of RTI interventions to get their insight on design, implementation and evaluation aspects. We then conducted a workshop with key stakeholders to analyze the results of in-depth interviews, and to further discuss and identify key programmatic considerations when designing and implementing RTI interventions. We finally performed brainstorming sessions to assess potential system-wide effects of a selected intervention (Zero Tolerance), and to identify adaptation and redesign needs for this intervention.</p> <p>Results</p> <p>Key programmatic components were consistently identified that should be considered when designing and implementing RTI interventions. They include effective and sustained political commitment and planning; sufficient and sustained budget allocation; training, supervision, monitoring and evaluation of implemented policies; multisectoral participation; and strong governance and accountability. Brainstorming sessions revealed major negative effects of the selected intervention on various system building blocks.</p> <p>Conclusions</p> <p>Our approach revealed substantial caveats in current RTI interventions in Peru, and fundamental negative effects on several components of the sectors and systems involved. It also highlighted programmatic issues that should be applied to guarantee an effective implementation and evaluation of these policies. The findings from this study were discussed with key stakeholders for consideration in further designing and planning RTI control interventions in Peru.</p

    Attending to warning signs of primary immunodeficiencies disease across the range of clinical practices

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    Purpose: Patients with primary immunodeficiency diseases (PIDD) may present with recurrent infections affecting different organs, organ-specific inflammation/autoimmunity, and also increased cancer risk, particularly hematopoietic malignancies. The diversity of PIDD and the wide age range over which these clinical occurrences become apparent often make the identification of patients difficult for physicians other than immunologists. The aim of this report is to develop a tool for educative programs targeted to specialists and applied by clinical immunologists. Methods: Considering the data from national surveys and clinical reports of experiences with specific PIDD patients, an evidence-based list of symptoms, signs, and corresponding laboratory tests were elaborated to help physicians other than immunologists look for PIDD. Results: Tables including main clinical manifestations, restricted immunological evaluation, and possible related diagnosis were organized for general practitioners and 5 specialties. Tables include information on specific warning signs of PIDD for pulmonologists, gastroenterologists, dermatologists, hematologists, and infectious disease specialists. Conclusions: This report provides clinical immunologists with an instrument they can use to introduce specialists in other areas of medicine to the warning signs of PIDD and increase early diagnosis. Educational programs should be developed attending the needs of each specialty.Fil: Costa Carvalho, Beatriz Tavares. Universidade Federal de SĂŁo Paulo; BrasilFil: Sevciovic Grumach, Anete. Fundação ABC. Faculdade de Medicina; BrasilFil: Franco, JosĂ© Luis. Universidad de Antioquia; ColombiaFil: Espinosa Rosales, Francisco Javier. Instituto Nacional de PediatrĂ­a. Unidad de InvestigaciĂłn en Inmunodeficiencias; MĂ©xicoFil: Leiva, Lily E.. State University of Louisiana; Estados UnidosFil: King, Alejandra. Hospital de Niños Doctor Luis Calvo Mackenna. Unidad de InmunologĂ­a; ChileFil: Porras, Oscar. Hospital Nacional de Niños “Dr. Carlos SĂĄenz Herrera”; Costa RicaFil: Bezrodnik, Liliana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo GutiĂ©rrez"; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Oleastro, Mathias. Gobierno de la Ciudad de Buenos Aires. Hospital de PediatrĂ­a "Juan P. Garrahan"; ArgentinaFil: Sorensen, Ricardo U.. State University of Louisiana; Estados Unidos. Universidad de La Frontera. Facultad de Medicina; MĂ©xicoFil: Condino Neto, Antonio. Universidade de Sao Paulo; Brasi

    Airway smooth muscle as a target of asthma therapy: history and new directions

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    Ultimately, asthma is a disease characterized by constriction of airway smooth muscle (ASM). The earliest approach to the treatment of asthma comprised the use of xanthines and anti-cholinergics with the later introduction of anti-histamines and anti-leukotrienes. Agents directed at ion channels on the smooth muscle membrane (Ca(2+ )channel blockers, K(+ )channel openers) have been tried and found to be ineffective. Functional antagonists, which modulate intracellular signalling pathways within the smooth muscle (ÎČ-agonists and phosphodiesterase inhibitors), have been used for decades with success, but are not universally effective and patients continue to suffer with exacerbations of asthma using these drugs. During the past several decades, research energies have been directed into developing therapies to treat airway inflammation, but there have been no substantial advances in asthma therapies targeting the ASM. In this manuscript, excitation-contraction coupling in ASM is addressed, highlighting the current treatment of asthma while proposing several new directions that may prove helpful in the management of this disease
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