1,896 research outputs found

    Association between maternal-fetal genetic histocompatibility and maternal undernutrition in mice: influence on intrauterine growth

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    OBJECTIVE: The purpose of this study was to evaluate the effects of maternal-fetal genetic histocompatibility and the association of that condition with maternal undernutrition regarding fetal growth and litter size. STUDY DESIGN: Fetuses that were either syngeneic or allogeneic with the mothers were bred, using mice of well-defined syngeneic strains (A/J and Balb/c). Pregnant mice were fed using either unrestricted normal diet with 22% protein, consumed ad libitum, or a diet containing 14% protein, with intake restricted to 70% of that consumed by the unrestricted group. At the end of gestation, the number of fetoplacental units and fetal losses, the fetal and placental weight, and the weights of fetal brain and liver were recorded. RESULTS: Fetuses from undernourished mothers showed a reduction in body, placental, and brain weight (P < 0.01); the association of undernourishment with maternal-fetal genetic compatibility resulted in a greater impairment of fetal growth (P < 0.01). A reduction in the number of viable fetuses per female in the dietary-restricted groups was observed. (P < 0.01). Although the concurrence of maternal-fetal genetic compatibility resulted in a trend towards a greater reduction in the number of viable fetuses as well as in a higher rate of fetal loss, these differences did not reach statistical significance. CONCLUSIONS: In mice, the occurrence of maternal-fetal genetic histocompatibility alone did not change fetal growth; maternal undernutrition during pregnancy resulted in growth stunting of progenies with reduction of litter size; and the association of these 2 factors produced greater reduction of fetal weight.OBJETIVO: Avaliar os efeitos da histocompatibilidade genética materno-fetal e sua associação com a desnutrição materna em relação ao crescimento fetal e número de fetos. MÉTODOS: Fetos singênicos ou alogênicos em relação às respectivas mães foram obtidos através de cruzamentos de camundongos com linhagens genéticas bem definidas (A/J e Balb/c). As fêmeas grávidas foram alimentadas ad libitum com dieta normal contendo 22% de proteínas ou dieta com restrição, contendo 14% de proteína e aporte máximo de 70% do total consumido pelo grupo em dieta livre. No final da gestação, o número de unidades feto-placentárias e de perdas fetais, o peso da placenta e do feto, assim como o peso do cérebro e do fígado foram anotados. RESULTADOS: Os fetos das mães submetidas à desnutrição mostraram redução no peso corpóreo, placentário e cerebral (

    Utilization of the Lower Inflection Point of the Pressure-Volume Curve Results In Protective Conventional Ventilation Comparable to High Frequency Oscillatory Ventilation in an Animal Model of Acute Respiratory Distress Syndrome

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    INTRODUCTION: Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE: To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume curve as the determinant of positive end-expiratory pressure to obtain similar levels of recruitment and alveolar stability. METHODS: After lung lavage of adult rabbits and lower inflection point determination, two groups were randomized: conventional (positive end-expiratory pressure = lower inflection point; tidal volume=6 ml/kg) and high frequency ventilation (mean airway pressures= lower inflection point +4 cmH2O). Blood gas and hemodynamic data were recorded over 4 h. After sacrifice, protein analysis from lung lavage and histologic evaluation were performed. RESULTS: The oxygenation parameters, protein and histological data were similar, except for the fact that significantly more normal alveoli were observed upon protective ventilation. High frequency ventilation led to lower PaCO2 levels. DISCUSSION: Determination of the lower inflection point of the pressure-volume curve is important for setting the minimum end expiratory pressure needed to keep the airways opened. This is useful when comparing different strategies to treat severe respiratory insufficiency, optimizing conventional ventilation, improving oxygenation and reducing lung injury. CONCLUSIONS: Utilization of the lower inflection point of the pressure-volume curve in the ventilation strategies considered in this study resulted in comparable efficacy with regards to oxygenation and hemodynamics, a high PaCO2 level and a lower pH. In addition, a greater number of normal alveoli were found after protective conventional ventilation in an animal model of acute respiratory distress syndrome

    Evaluation of peak inspiratory pressure, tidal volume and respiratory rate during ventilation of premature lambs using a self-inflating bag

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    OBJECTIVE: To evaluate the peak inspiratory pressure, tidal volume and respiratory rate achieved during manual ventilation of premature lambs, using a self-inflating bag. METHODS: In this descriptive, experimental study, five pairs of physicians, selected at random among 35 neonatologists working at a neonatal intensive care unit and with experience in the resuscitation of newborn infants, ventilated five intubated premature lambs using a self-inflating bag. Pressure and flow monitor signals were passed through a transducer and digitized for recording and analysis. Tidal volume and pressure curves were obtained from the integral of flow rate, at peak, during the last 50 seconds of every fifth minute, and analyzed. RESULTS: Median pressure was 39.8 (IQ25-75% 30.2-47.2) cmH2O; being below 20 in 1.1% of cases and above 40 in 49.1%. Seven out of 10 physicians produced more than six pressure peaks of over 40 cmH2O. Median tidal volume/kg was 17.8 (IQ25-75% 14.1-22.4) mL, being below 5 mL in 0.1% of cases and greater than or equal to 20 mL in 37.7%. All of the physicians propelled five or more ventilation cycles with tidal volume/kg of 20 mL or more. Respiratory rate was between 30 and 60 cycles/minute in 65.9% of cases, being below 30 in 6.8% of cases and over 60 in 27.3% of cases. CONCLUSIONS: There was major variation in peak inspiratory pressure and tidal volume/kg values, which were in many cases elevated, attaining levels that habitually cause biotrauma, while respiratory rates were adequate in the majority of cases.OBJETIVO: Avaliar o pico de pressão inspiratória, o volume corrente e a freqüência respiratória obtidos durante ventilação manual de carneiros prematuros, utilizando balão auto-inflável. MÉTODOS: Estudo experimental descritivo em que cinco duplas de médicos selecionados aleatoriamente entre 35 neonatologistas que trabalham em unidade de terapia intensiva neonatal e experientes em reanimação de recém-nascidos ventilaram cinco carneiros prematuros intubados, utilizando balão auto-inflável. Os sinais de pressão e fluxo eram captados, convertidos por meio de transdutores e digitalizados para armazenamento e análise. Foram avaliadas curvas de pressão e de volume corrente, este a partir da integral do fluxo, em suas medidas de pico, nos 50 segundos finais de cada 5 minutos. RESULTADOS: A mediana da pressão foi de 39,8 (IQ25-75% 30,2-47,2) cmH2O; foi menor que 20 em 1,1% das vezes e maior que 40 em 49,1%. Sete em 10 médicos propiciaram mais de seis picos de pressão maiores que 40 cmH2O. A mediana do volume corrente/kg foi de 17,8 (IQ25-75% 14,1-22,4) mL, sendo menor que 5 mL em 0,1% das vezes e igual ou maior que 20 mL em 37,7%. Todos os médicos impuseram cinco ou mais ciclos ventilatórios com volume corrente/kg de 20 mL ou mais. A freqüência situou-se entre 30 e 60 ciclos/minuto em 65,9% das vezes, sendo menor que 30 em 6,8% e maior que 60 em 27,3% das vezes. CONCLUSÃO: Ocorreu grande variabilidade nos valores do pico de pressão inspiratória e do volume corrente/kg, sendo muitas vezes elevados e alcançando níveis indutores de biotrauma; para a freqüência respiratória, os valores foram adequados na maioria das vezes.Universidade de BrasíliaUnBUniversidade Federal de São Paulo (UNIFESP)UnB Hospital Universitário da UnBUniversidade de São Paulo Faculdade de Medicina Instituto da Criança do Hospital das ClínicasUNIFESPSciEL

    Análise da imunogenicidade e da estabilidade do surfactante pulmonar de origem porcina administrado em coelhos

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    PURPOSE: To study the immunogenicity and the stability of the porcine pulmonary surfactant preparation produced by the Instituto Butantan. METHOD: Immunogenicity assay: Sixteen New-Zealand-White rabbits (1000 g body weight) were divided into 4 study groups. Each group was assigned to receive either a) Butantan surfactant, b) Survanta® (Abbott Laboratories), c) Curosurf® (Farmalab Chiesi), or d) no surfactant. The surfactants were administered intratracheally, and the animals were collected immediately before and 60 and 180 days after surfactant administration. Sera were assayed for the presence of antisurfactant antibodies by enzyme-linked immunosorbent assay (ELISA). Stability assay: The Butantan surfactant used in this assay had been stored for one year in the refrigerator (4 to 8ºC) and its stability was evaluated in distinct assay conditions using a premature rabbit model. RESULTS: Immunogenicity assay: None of the surfactants analyzed triggered antibody immune responses against their components in any of the animals. Stability assay: The results of this study demonstrate that Butantan surfactant was as effective as Curosurf when both were submitted to the adverse circumstance of short- and long-term storage at room temperature. A similar level of efficacy for the Butantan surfactant, as compared to Curosurf was demonstrated by the pulmonary dynamic compliance, ventilatory pressure, and pressure-volume curve results. CONCLUSION: The results of our study demonstrate that Butantan surfactant may be a suitable alternative for surfactant replacement therapy.OBJETIVO: Estudar a imunogenicidade e a estabilidade do surfactante de origem porcina produzido pelo Instituto Butantan. MÉTODO: Experimento imunogenicidade: 16 coelhos da raça New-Zealand-White (Peso de 1000g) foram divididos em grupos de 4 animais. Cada grupo foi designado para receber: a) Surfactante do Butantan, b) Survanta® (Abbott Laboratories), c) Curosurf (Farmalab Chiesi) e d) nenhum tratamento com surfactante. Os surfactantes foram administrados via intratraqueal e o sangue dos animais foi coletado antes, 60 e 180 dias após a administração do surfactante. O soro obtido foi analisado quanto a presença de anticorpos anti-surfactante pelo método ELISA (enzyme-linked immunosorbent assay). Experimento estabilidade: O surfactante do Butantan usado neste experimento tinha sido armazenado por um ano em refrigerador (4 a 8&deg;C) e sua estabilidade foi analisada em condições distintas de experimentação, usando o modelo de coelho prematuro. RESULTADOS: Experimento imunogenicidade: Nenhum dos surfactantes analisados determinou a produção de anticorpos contra seus constituintes. Experimento estabilidade: Os resultados deste estudo demonstraram que o surfactante do Instituto Butantan mostrou eficácia semelhante a do Curosurf após ter sido submetido à condições adversas ao longo do tempo. A eficácia foi demonstrada através da complacência pulmonar dinâmica, pressão ventilatória e da curva pressão-volume. CONCLUSÃO: Os resultados deste estudo demonstraram que o surfactante do Instituto Butantan pode representar um tratamento alternativo de reposição de surfactante

    Comparison of serum hepatitis B virus replication markers in patients with chronic hepatitis B: studies on HBeAg/Anti-HBe system, viral dna polymerase and HBV-DNA

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    The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker of replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV - related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.A detecção do genoma do HBV no soro por hibridização molecular é o mais sensível e específico marcador da replicação e infectividade do HBV, sendo sua utilização proposta como técnica rotineira no acompanhamento de doenças relacionadas a este vírus. Comparando diferentes técnicas descritas anteriormente, escolhemos a deposição direta das amostras séricas sobre a membrana de nitrocelulose sob filtração a vácuo, seguida de banhos desnaturantes e neutralisantes como mais prática e simples, com sensibilidade equivalente. O ensaio da DNA polimerase usando ácido fosfonofórmico como inibidor virai específico mostrou 86.8% de concordância com a detecção direta do DNA viral, sendo, portanto, uma alternativa viável no acompanhamento de pacientes com hepatite crônica B. Encontramos 19,2% das amostras AgHBe positivos sem outros marcadores de replicação viral. Por outro lado, nenhuma amostra anti-HBe positiva teve HBV-DNA detectável. Discordância entre estes dois sistemas foi extensamente descrita, e confirmamos pela primeira vez este fato em pacientes com hepatite crônica B em nosso país. Técnicas de biologia molecular são, portanto, fundamentais na determinação da replicação viral em cada paciente

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV
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