194 research outputs found

    Evidence for a role of nitric oxide in hindlimb vasodilation induced by hypothalamic stimulation in anesthetized rats

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    Electrical stimulation of the hypothalamus produces cardiovascular adjustments consisting of hypertension, tachycardia, visceral vasoconstriction and hindlimb vasodilation. Previous studies have demonstrated that hindlimb vasodilation is due a reduction of sympathetic vasoconstrictor tone and to activation of beta2-adrenergic receptors by catecholamine release. However, the existence of a yet unidentified vasodilator mechanism has also been proposed. Recent studies have suggested that nitric oxide (NO) may be involved. The aim of the present study was to investigate the role of NO in the hindquarter vasodilation in response to hypothalamic stimulation. In pentobarbital-anesthetized rats hypothalamic stimulation (100 Hz, 150µA, 6 s) produced hypertension, tachycardia, hindquarter vasodilation and mesenteric vasoconstriction. Alpha-adrenoceptor blockade with phentolamine (1.5 mg/kg, iv) plus bilateral adrenalectomy did not modify hypertension, tachycardia or mesenteric vasoconstriction induced by hypothalamic stimulation. Hindquarter vasodilation was strongly reduced but not abolished. The remaining vasodilation was completely abolished after iv injection of the NOS inhibitor L-NAME (20 mg/kg, iv). To properly evaluate the role of the mechanism of NO in hindquarter vasodilation, in a second group of animals L-NAME was administered before alpha-adrenoceptor blockade plus adrenalectomy. L-NAME treatment strongly reduced hindquarter vasodilation in magnitude and duration. These results suggest that NO is involved in the hindquarter vasodilation produced by hypothalamic stimulation.Em animais anestesiados a EE do hipotálamo produz um padrão de ajustes cardiovasculares caracterizado por hipertensão arterial, taquicardia, vasodilatação muscular e vasoconstrição mesentérica, entretanto, os mecanismos periféricos envolvidos nestes ajustes cardiovasculares ainda não foram completamente esclarecidos. O presente estudo teve como objetivo caracterizar os mecanismos periféricos responsáveis pela redistribuição de fluxo sanguíneo produzidas pela EE do hipotálamo. Os resultados obtidos demonstraram que 1) em ratos anestesiados a EE do hipotálamo produziu hipertensão arterial, taquicardia, vasoconstrição no leito mesentérico e acentuada vasodilatação dos membros posteriores; 2) a combinação do bloqueio farmacológico de receptores alfa1 e alfa2 adrenérgicos com fentolamina mais adrenalectomia bilateral reduziu a vasoconstrição mesentérica e a vasodilatação dos membros posteriores. Nestes animais o bloqueio da síntese de NO com L-NAME provocou nova redução significante da vasodilatação dos membros posteriores; 3) a administração de L-NAME, previamente o bloqueio farmacológico com fentolamina mais adrenalectomia bilateral, reduziu as respostas de vasoconstrição mesentérica e de vasodilatação dos membros posteriores. Estes resultados sugerem a existência de pelo menos três possíveis mecanismos responsáveis pela vasodilatação dos membros posteriores induzida pela EE do hipotálamo: 1) ativação de receptores beta-adrenérgicos por catecolaminas liberadas pela medula adrenal; 2) redução do tono vasoconstritor simpático e 3) um terceiro mecanismo que utiliza NO como mediador.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNIFESP-EPM Departamento de FisiologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

    Desempenho agronômico e produção de matéria seca digestível de híbridos de sorgo com capim sudão, normais e mutantes BMR (portadores de nervura marrom).

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    O objetivo deste trabalho foi avaliar as características agronômicas e a produção de matéria seca digestível de híbridos de sorgo com capim sudão mutantes BMR (portadores de nervura marrom) em comparação a híbridos normais. Os vinte e cinco híbridos foram avaliados quanto à altura de plantas, número de plantas por hectare, produção de matéria verde por hectare, produção de matéria seca por hectare e produção de matéria seca digestível por hectare. Os valores médios observados foram: 1,42 metros, 187 mil plantaslha, 39,62 tonlha, 3,73 tonlha e 2,65 tonlha, respectivamente para os seguintes parâmetros avaliados: altura de planta, stand de planta, produção de matéria verde, produção de matéria seca e produção de matéria seca digestíveI. De acordo com os resultados apresentados, a mutação com gene BMR expressam de forma desuniforme entre os diferentes cultivares. Em alguns cruzamentos, a inclusão do gene BMR não deprimiu significativamente as características agronômicas avaliadas. A produção de matéria seca digestível não diferiu significativamente entre os materiais avaliados devido à maior digestibilidade da matéria seca observada nos híbridos mutantes BMR

    Proteína bruta e digestibilidade in vitro da matéria seca de híbridos de sorgo com capim sudão, normais e mutantes BMR (portadores de nervura marrom).

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    O objetivo deste trabalho foi avaliar o valor nutricional de híbridos de sorgo com capim sudão mutantes BMR (portadores de nervura marrom) em comparação a híbridos normais. Os vinte e cinco híbridos foram avaliados quanto ao teor de proteína bruta na matéria seca e a digestibilidade in vitro da matéria seca. O delineamento estatístico utilizado foi o de blocos ao acaso e a comparação das médias pelo teste Scott-Knott com 5% de significância. Os valores de proteína bruta variaram de 9,90 a 14,40% sendo que a média foi de 12,04%. Não foi observado diferença estatística entre os materiais avaliados. Os valores de digestibilidade in vitro da matéria seca variaram de 65,34 a 76,27% sendo que a média foi de 71,56%.. Para este parâmetro foi observado diferença estatística entre os materiais avaliados. A presença do gene BMR foi responsável por melhorar significativamente a digestibilidade in vitro da matéria seca dos híbridos de sorgo com capim Sudão

    Effectiveness of peer educators on the uptake of mobile X-ray tuberculosis screening at homeless hostels: a cluster randomised controlled trial.

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    To compare current practice for encouraging homeless people to be screened for tuberculosis on a mobile digital X-ray unit in London, UK, with the additional use of volunteer peer educators who have direct experience of tuberculosis, homelessness or both

    Occurrence of foodborne pathogens in Italian soft artisanal cheeses displaying different intra- and inter-batch variability of physicochemical and microbiological parameters

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    Artisanal cheeses are produced in small-scale production plants, where the lack of full automation and control of environmental and processing parameters suggests a potential risk of microbial contamination. The aim of this study was to perform a longitudinal survey in an Italian artisanal factory producing a spreadable soft cheese with no rind to evaluate the inter- and intra-batch variability of physicochemical and microbial parameters on a total of 720 environmental and cheese samples. Specifically on cheese samples, the evaluation was additionally performed on physicochemical parameters. Cheese samples were additionally collected during 15 days of storage at constant temperatures of 2 and 8 degrees C, as well as a dynamic profile of 2 degrees C for 5 days and 8 degrees C for 10 days. Furthermore, Enterobacteriaceae isolates were identified at species level to have a better knowledge of the environmental and cheese microbiota potentially harboring human pathogens. High inter-batch variability was observed for lactic acid bacteria (LAB) and total bacteria count (TBC) in cheese at the end of production but not for pH and water activity. A temperature of 8 degrees C was associated with a significantly higher load of Enterobacteriaceae in cheeses belonging to batch 6 at the end of storage, and this temperature also corresponded with the highest increase in LAB and TBC loads over cheese shelf life. Results from generalized linear mixed models (GLMMs) indicated that drains in the warm room and the packaging area were associated with higher levels of TBC and Enterobacteriaceae in cheese. Regarding foodborne pathogens, no sample was positive for verotoxigenic Escherichia coli (VTEC) or Listeria monocytogenes, whereas six Staphylococcus aureus and one Salmonella pullorum isolates were collected in cheese samples during storage and processing, respectively. Regarding Enterobacteriaceae, 166 isolates were identified at species level from all batches, with most isolates belonging to Klebsiella oxytoca and pneumoniae, Enterobacter cloacae, Hafnia alvei, and Citrobacter freundii evidencing the need to focus on standardizing the microbial quality of cow milk and on hygienic procedures for cleaning and disinfection especially in warm and maturation rooms. Further studies should be performed to investigate the potential pathogenicity and antimicrobial resistance of the identified Enterobacteriaceae species in artisanal cheeses

    Perfil fermentativo das silagens de seis genótipos de sorgo ("Sorghum bicolor (L.) Moench. ") 1. MS; PB; N-NH3 e pH.

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    O presente trabalho teve como objetivo estudar o efeito do intervalo de abertura de silos sobre o perfil fermentativo de silagens de seis genótipos de sorgo (BR 700, BRS 610, 0249311, 0249313,0249345 e 0249351). Foram avaliados os parâmetros de matéria seca (MS), proteína bruta (PB), nitrogênio amoniacal (%N-NH3/NT) e pH das silagens. Os materiais foram plantados na EMBRAPA Milho e Sorgo, ensilados em silos de laboratório e analisados após, um, três, cinco, sete, 14, 28 e 56 dias de fermentação no Laboratório de Nutrição Animal da Escola de Veterinária da UFMG. Os valores de MS, PB, N-NH3 e pH das silagens variaram de 26,77 a 39,49%; 6,28 a 7,1%; 1,25 a 3,31%; 3,84 a 4,02%, respectivamente. As silagens dos seis genótipos de sorgo apresentaram adequados teores de MS, PB, N-NH3 e pH

    Perfil de fermentação das silagens de seis genótipos de sorgo ("Sorghum bicolor (L.) Moench.") - Ácidos orgânicos.

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    Foram determinados os valores de ácidos orgânicos das silagens de seis genótipos de sorgo (BR 700, BRS 61O, 0249311, 0249313 ,0249345 e 0249351). Os materiais foram plantados na EMBRAPA Milho e Sorgo, ensilados em silos de laboratório e analisados após, 1, 3, 5, 7, 14, 28 e 56 dias de fermentação no Laboratório de Nutrição Animal da Escola de Veterinária da UFMG. Os teores dos ácidos lático, propiônico e acético variaram, respectivamente de 4,21 a 6,31%, de 0,28 a 0,33% e de 0,01 a 0,06%. Após 56 dias de fermentação os valores médios para ácido lático, propiônico e acético foram de 7,74%, 0,36% e 0,04%, respectivamente. As silagens dos seis genótipos de sorgo apresentaram adequados teores de ácidos orgânicos

    Management and control of tuberculosis control in socially complex groups: a research programme including three RCTs

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    Background: Socially complex groups, including people experiencing homelessness, prisoners and drug users, have very high levels of tuberculosis, often complicated by late diagnosis and difficulty in adhering to treatment. / Objective: To assess a series of interventions to improve tuberculosis control in socially complex groups. / Design: A series of observational surveys, evaluations and trials of interventions. / Setting: The pan-London Find&Treat service, which supports tuberculosis screening and case management in socially complex groups across London. / Participants: Socially complex groups with tuberculosis or at risk of tuberculosis, including people experiencing homelessness, prisoners, drug users and those at high risk of poor adherence to tuberculosis treatment. Interventions and main outcome measures We screened 491 people in homeless hostels and 511 people in prison for latent tuberculosis infection, human immunodeficiency virus, hepatitis B and hepatitis C. We evaluated an NHS-led prison radiographic screening programme. We conducted a cluster randomised controlled trial (2348 eligible people experiencing homelessness in 46 hostels) of the effectiveness of peer educators (22 hostels) compared with NHS staff (24 hostels) at encouraging the uptake of mobile radiographic screening. We initiated a trial of the use of point-of-care polymerase chain reaction diagnostics to rapidly confirm tuberculosis alongside mobile radiographic screening. We undertook a randomised controlled trial to improve treatment adherence, comparing face-to-face, directly observed treatment with video-observed treatment using a smartphone application. The primary outcome was completion of ≥ 80% of scheduled treatment observations over the first 2 months following enrolment. We assessed the cost-effectiveness of latent tuberculosis screening alongside radiographic screening of people experiencing homelessness. The costs of video-observed treatment and directly observed treatment were compared. / Results: In the homeless hostels, 16.5% of people experiencing homelessness had latent tuberculosis infection, 1.4% had current hepatitis B infection, 10.4% had hepatitis C infection and 1.0% had human immunodeficiency virus infection. When a quality-adjusted life-year is valued at £30,000, the latent tuberculosis screening of people experiencing homelessness was cost-effective provided treatment uptake was ≥ 25% (for a £20,000 quality-adjusted life-year threshold, treatment uptake would need to be > 50%). In prison, 12.6% of prisoners had latent tuberculosis infection, 1.9% had current hepatitis B infection, 4.2% had hepatitis C infection and 0.0% had human immunodeficiency virus infection. In both settings, levels of latent tuberculosis infection and blood-borne viruses were higher among injecting drug users. A total of 1484 prisoners were screened using chest radiography over a total of 112 screening days (new prisoner screening coverage was 43%). Twenty-nine radiographs were reported as potentially indicating tuberculosis. One prisoner began, and completed, antituberculosis treatment in prison. In the cluster randomised controlled trial of peer educators to increase screening uptake, the median uptake was 45% in the control arm and 40% in the intervention arm (adjusted risk ratio 0.98, 95% confidence interval 0.80 to 1.20). A rapid diagnostic service was established on the mobile radiographic unit but the trial of rapid diagnostics was abandoned because of recruitment and follow-up difficulties. We randomly assigned 112 patients to video-observed treatment and 114 patients to directly observed treatment. Fifty-eight per cent of those recruited had a history of homelessness, addiction, imprisonment or severe mental health problems. Seventy-eight (70%) of 112 patients on video-observed treatment achieved the primary outcome, compared with 35 (31%) of 114 patients on directly observed treatment (adjusted odds ratio 5.48, 95% confidence interval 3.10 to 9.68; p < 0.0001). Video-observed treatment was superior to directly observed treatment in all demographic and social risk factor subgroups. The cost for 6 months of treatment observation was £1645 for daily video-observed treatment, £3420 for directly observed treatment three times per week and £5700 for directly observed treatment five times per week. / Limitations: Recruitment was lower than anticipated for most of the studies. The peer advocate study may have been contaminated by the fact that the service was already using peer educators to support its work. / Conclusions: There are very high levels of latent tuberculosis infection among prisoners, people experiencing homelessness and drug users. Screening for latent infection in people experiencing homelessness alongside mobile radiographic screening would be cost-effective, providing the uptake of treatment was 25–50%. Despite ring-fenced funding, the NHS was unable to establish static radiographic screening programmes. Although we found no evidence that peer educators were more effective than health-care workers in encouraging the uptake of mobile radiographic screening, there may be wider benefits of including peer educators as part of the Find&Treat team. Utilising polymerase chain reaction-based rapid diagnostic testing on a mobile radiographic unit is feasible. Smartphone-enabled video-observed treatment is more effective and cheaper than directly observed treatment for ensuring that treatment is observed. / Future work: Trials of video-observed treatment in high-incidence settings are needed. / Trial registration: Current Controlled Trials ISRCTN17270334 and ISRCTN26184967. / Funding: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 8, No. 9. See the NIHR Journals Library website for further project information
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