879 research outputs found
Effects of acid-base imbalance on vascular reactivity
Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo) and those occurring within the intracellular space (pHi), although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent), prostacyclin (PGI2/cAMP-dependent) and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.FAPESPFAEP
Potential drug interactions and drug risk during pregnancy and breastfeeding: an observational study in a women's health intensive care unit
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQIntroduction In the pregnancy-puerperal cycle, women may develop complications that require admission to the Intensive Care Unit (ICU). Thus, special attention to pharmacotherapy is necessary, particularly to potential drug interactions (PDIs) and to the396258264FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQsem informaçãosem informaçãoThe researchers would like to thank the multidisciplin ary team of the ICU, the pharmacy staff of the hospital, and the authors, for their support and collaboration during the research. Financial support from student fellowships was provided by Fundaçã
Hofmeister Effect in Confined Spaces: Halogen Ions and Single Molecule Detection
AbstractDespite extensive research in the nanopore-sensing field, there is a paucity of experimental studies that investigate specific ion effects in confined spaces, such as in nanopores. Here, the effect of halogen anions on a simple bimolecular complexation reaction between monodisperse poly(ethylene glycol) (PEG) and α-hemolysin nanoscale pores have been investigated at the single-molecule level. The anions track the Hofmeister ranking according to their influence upon the on-rate constant. An inverse relationship was demonstrated for the off-rate and the solubility of PEG. The difference among anions spans several hundredfold. Halogen anions play a very significant role in the interaction of PEG with nanopores although, unlike K+, they do not bind to PEG. The specific effect appears dominated by a hydration-dehydration process where ions and PEG compete for water. Our findings provide what we believe to be novel insights into physicochemical mechanisms involved in single-molecule interactions with nanopores and are clearly relevant to more complicated chemical and biological processes involving a transient association of two or more molecules (e.g., reception, signal transduction, enzyme catalysis). It is anticipated that these findings will advance the development of devices with nanopore-based sensors for chemical and biological applications
Percolation approach to quark gluon plasma in high energy pp collisions
We apply continuum percolation to proton-proton collisions and look for the
possible threshold to phase transition from confined nuclear matter to quark
gluon plasma. Making the assumption that J/Psi suppression is a good signal to
the transition, we discuss this phenomenon for pp collisions, in the framework
of a dual model with strings.Comment: 8 pages, 3 figure
Photonuclear reactions of actinides in the giant dipole resonance region
Photonuclear reactions at energies covering the giant dipole resonance (GDR)
region are analyzed with an approach based on nuclear photoabsorption followed
by the process of competition between light particle evaporation and fission
for the excited nucleus. The photoabsorption cross section at energies covering
the GDR region is contributed by both the Lorentz type GDR cross section and
the quasideuteron cross section. The evaporation-fission process of the
compound nucleus is simulated in a Monte-Carlo framework. Photofission reaction
cross sections are analyzed in a systematic manner in the energy range of
10-20 MeV for the actinides Th, U and Np.
Photonuclear cross sections for the medium-mass nuclei Cu and Zn,
for which there are no fission events, are also presented. The study reproduces
satisfactorily the available experimental data of photofission cross sections
at GDR energy region and the increasing trend of nuclear fissility with the
fissility parameter for the actinides.Comment: 4 pages including 2 tables and 1 figur
Explaining the Higgs Decays at the LHC with an Extended Electroweak Model
We show that the recent discovery of a new boson at the LHC, which we assume
to be a Higgs boson, and the observed enhancement in its diphoton decays
compared to the SM prediction, can be explained by a new doublet of charged
vector bosons from an extended electroweak gauge sector model with
SU(3)_C\otimesSU(3)_L\otimesU(1)_X symmetry. Our results show a good
agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs
boson and the experimental significance observed in the diphoton channel at the
8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also
taken into account, in order to anticipate a possible confirmation of deficits
in the branching ratios into , , bottom quarks, and tau leptons.Comment: 16 pages, 5 figure
Effect Of Pasteurization On The Decay Of Mycobacterium Bovis In Milk Cream
Milk cream must be pasteurized in order to be sold in Brazil. However, there are no specific legal requirements for this product, and producers set their own pasteurization parameters using the ones approved for milk as a reference. Considering that fat protects bacteria from heat, that no thermal inactivation studies have been performed on Mycobacterium bovis present in cream, and that bovine tuberculosis is endemic in Brazil, the aim of this study was to evaluate the inactivation of M. bovis in milk cream subjected to commercial parameters of pasteurization. Milk cream samples were contaminated and pasteurized in a water bath at 75, 80, 85, and 90°C for 5 and 15 s. M. bovis cells were plated onto Stonebrink-Leslie medium, incubated at 36°C for 45 days, and quantified; the result was expressed in log CFU mL-1. The fat content of the samples ranged from 34% to 37% and the average initial load of M. bovis was 8.0 Log CFU mL-1. The average decay of the M. bovis populations was 4.0, 4.3, 4.9 and 6.7 log CFU mL-1 when the cream was treated for 15 sec at 75, 80, 85 and 90°C, respectively, showing that the efficiency of the heat treatment was improved by increasing the temperature of the process. Given the lipophilic nature of M. bovis, the cream should be subjected to more intense parameters of pasteurization than those applied to milk.3753737374
Papilomavírus humano e anormalidades cervicais em mulheres do sistema de saúde privado e público no Estado do Rio de Janeiro, Brasil
This article reports the HPV status and cervical cytological abnormalities in patients attended at public and private gynecological services from Rio de Janeiro State. It also comments the performance of each HPV DNA tests used. A set of 454 women from private health clinics was tested by routine Capture Hybrid II HPV DNA assay. Among these, 58.4% presented HPV and nearly 90% of them were infected by high risk HPV types. However, this group presented few premalignant cervical lesions and no invasive cervical cancer was registered. We also studied 220 women from low income class attended at public health system. They were HPV tested by polymerase chain reaction using My09/11 primers followed by HPV typing with E6 specific primers. The overall HPV prevalence was 77.3%. They also showed a high percentage of high squamous intraepithelial lesion-HSIL (26.3%), and invasive cervical carcinoma (16.3%). HPV infection was found in 93.1% and 94.4% of them, respectively. The mean ages in both groups were 31.5 and 38 years, respectively. In series 1, HPV prevalence declined with age, data consistent with viral transient infection. In series 2, HPV prevalence did not decline, independent of age interval, supporting not only the idea of viral persistence into this group, but also regional epidemiological variations in the same geographic area. Significant cytological differences were seen between both groups. Normal and benign cases were the most prevalent cytological findings in series 1 while pre-malignant lesions were the most common diagnosis in the series 2. HPV prevalence in normal cases were statistically higher than those from series 1 (p < 0.001), indicating a higher exposure to HPV infection. Women from both samples were referred for previous abnormal cytology. However, socio-demographic evidence shows that women from series 1 have access to treatment more easily and faster than women from series 2 before the development of pre-malignant lesions. These data provides baseline support for the role of social inequalities linked to high risk HPV infection leading to cervical cancer. Broadly screening programs and the development of safe and effective vaccines against HPV would diminish the toll of this disease that affect mainly poor women.Este artigo analisa a infecção por HPV e anormalidades citológicas cervicais encontradas em pacientes atendidas em serviços ginecológicos dos sistemas de saúde público e privado do estado do Rio de Janeiro. O trabalho também avalia os testes utilizados para detecção de DNA do HPV em cada população estudada. Um grupo de 454 mulheres oriundas de serviços da rede privada de saúde foi testado por Captura do Híbrido II. Destas, 58,4% apresentaram infecção por HPV e cerca de 90% delas estavam infectadas por HPV de alto risco. Este grupo, entretanto, apresentava poucos casos de lesões cervicais pré-malígnas e nenhum caso de câncer. Estudamos, também, 220 mulheres de baixo nível econômico atendidas no serviço de saúde pública que foram testadas para HPV pela reação da polimerase em cadeia utilizando-se os oligonucleotídeos My09/My11. A identificação dos tipos foi efetuada por amplificação com oligonucleotídeos específicos para a região E6 do genoma viral. A prevalência de HPV nesta população foi de 77.3%, observando-se uma alta porcentagem de casos de neoplasias intraepiteliais cervicais de alto grau (26,3%) e de carcinoma cervical invasivo (16,3%). A infecção por HPV foi achada em, respectivamente, 93,1% e 94,4% destes casos. A média de idade em ambos os grupos era de 31,5 e 38 anos, respectivamente. Na série 1, a prevalência da infecção por HPV decresce com a idade, enquanto na série 2 ela não desaparece, dando suporte não só à idéia de persistência viral neste grupo, mas também a variações epidemiológicas na mesma área geográfica. Diferenças significativas foram vistas nos dois grupos. Casos normais e benignos foram incidentes na série 1, enquanto as lesões malígnas predominaram na série 2. Ao contrário, casos normais infectados por HPV eram prevalentes na série 2 (p < 0.001), indicando maior exposição ao vírus. Embora as mulheres de ambos os grupos tenham sido incluídas no estudo por apresentarem citologia anormal, evidências sócio-demográficas demonstram que mulheres da série 1 tem acesso mais fácil e rápido ao tratamento do que as mulheres da série 2 antes que as lesões pré-malígnas se desenvolvam. Estes resultados fornecem dados sobre o papel das desigualdades sociais associadas à infecção por HPV de alto risco na progressão do câncer cervical. Programas de prevenção abrangentes e o desenvolvimento de vacinas eficazes e seguras contra o HPV poderiam reduzir o tributo desta doença que afeta principalmente mulheres pobres
Musculoskeletal evaluation in severe haemophilia A patients from Latin America
There is a paucity of literature on haemophilia treatment in Latin American countries, a region characterized by rapidly improving systems of care, but with substantial disparities in treatment between countries. The aim of this study was to evaluate the musculoskeletal status of haemophilia patients from Latin America and to examine the relationship between musculoskeletal status and treatment practices across countries. The Committee of Latin America on the Therapeutics of Inhibitor Groups conducted a survey of its member country representatives on key aspects of haemophilia treatment in 10 countries. Musculoskeletal status of patients was obtained during routine comprehensive evaluations between March 2009 and March 2011. Eligible patients had severe haemophilia A (factor VIII <1%) without inhibitors (<0.6 BU mL−1) and were ≥5 years of age. Musculoskeletal status was compared between three groups of countries, based primarily on differences in the availability of long‐term prophylaxis. Overall, 143 patients (5–66 years of age) were enrolled from nine countries. In countries where long‐term prophylaxis had been available for at least 10 years (Group A), patients aged 5–10 years had significantly better mean World Federation of Hemophilia clinical scores, fewer target joints and fewer affected joints than patients from countries where long‐term prophylaxis has been available for about 5 years (Group B) or was not available (Group C). In Latin America, the musculoskeletal status of patients with severe haemophilia without inhibitors has improved significantly in association with the provision of long‐term prophylaxis. As more countries in Latin America institute this practice, further improvements are anticipated
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