36 research outputs found

    Oxidative Stress in Hypertensive Patients Induces an Increased Contractility in Vein Grafts Independent of Endothelial Function

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    Objective. To evaluate the impact of oxidative stress on vascular reactivity to vasoconstrictors and on nitric oxide (NO) bioavailability in saphenous vein (SV) graft with endothelial dysfunction from hypertensive patients (HT). Methods. Endothelial function, vascular reactivity, oxidative state, nitrites and NO release were studied in isolated SV rings from HT and normotensive patients (NT). Only rings with endothelial dysfunction were used. Results. HT rings presented a hyperreactivity to vasoconstrictors that was reverted by diphenylene iodonium (DPI). In NT, no effect of DPI was obtained, but Nω-nitro-L-arginine methyl ester (L-NAME) increased the contractile response. NO was present in SV rings without endothelial function. Nitrites were higher in NT than in HT (1066.1 ± 86.3 pmol/mg; n = 11 versus 487.8 ± 51.6; n = 23; P < 0.01) and inhibited by nNOS inhibitor. L-arginine reversed this effect. Antioxidant agents increased nitrites and NO contents only in HT. The anti-nNOS-stained area by immunohistochemistry was higher in NT than HT. HT showed an elevation of oxidative state. Conclusions. Extraendothelial NO counter-regulates contractility in SV. However, this action could be altered in hypertensive situations by an increased oxidative stress or a decreased ability of nNOS to produce NO. Further studies should be performed to evaluate the implication of these results in graft patency rates

    Una experiencia innovadora en la formación de recursos humanos en investigación desde el grado: programa articulado de docentes y auxiliares estudiantiles

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    La Cátedra de Fisiología de la Facultad de Medicina de la Universidad Nacional de Tucumán implementó un programa innovador de formación de jóvenes investigadores. Determinar el nivel de destreza alcanzado en las diferentes áreas abordadas durante la formación, según autovaloración de los participantes; y describir la percepción estudiantil sobre la influencia de la Escuela en el deseo de seguir una carrera investigativa en el futuro y la necesidad de incorporar programas similares a la currícula universitaria. Se realizó un estudio cuali-cuantitativo, descriptivo-exploratorio en estudiantes que participaron del programa. La recolección de datos se realizó mediante una encuesta, con previo consentimiento informado. Para su procesamiento y análisis, se utilizó Microsoft Excel 2016. Participaron 13 estudiantes. Según su autovaloración, adquirieron un buen nivel de destrezas en manejo de bioterio, medición de presión en ratas, histología y necropsia, y niveles menos favorables en exposición y redacción de trabajos. El 50% participaron como autores y expositores. El programa influyó en la decisión de seguir una carrera investigativa y todos consideran importante incluirlo en la currícula. Este programa muestra un impacto positivo promoviendo la incorporación temprana de estudiantes al ámbito investigativo, formándose a la par de investigadores profesionales y auxiliares estudiantiles. Su integración al plan de estudios puede incluir a todos los alumnos. Es responsabilidad educativa conectar investigación, docencia y medicina clínica, para beneficio de las personas.Fil: Gepner, Maia Einath. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Salses, Florencia Marlen del Milagro. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Alberstein, Ramón Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Sanchez, Romel Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Marañón, Rodrigo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Peral de Bruno, María. Universidad Nacional de Tucumán. Facultad de Medicina; Argentin

    Una experiencia innovadora en la formación de recursos humanos en investigación desde el grado: programa articulado de docentes y auxiliares estudiantiles

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    La Cátedra de Fisiología de la Facultad de Medicina de la Universidad Nacional de Tucumán implementó un programa innovador de formación de jóvenes investigadores. Determinar el nivel de destreza alcanzado en las diferentes áreas abordadas durante la formación, según autovaloración de los participantes; y describir la percepción estudiantil sobre la influencia de la Escuela en el deseo de seguir una carrera investigativa en el futuro y la necesidad de incorporar programas similares a la currícula universitaria. Se realizó un estudio cuali-cuantitativo, descriptivo-exploratorio en estudiantes que participaron del programa. La recolección de datos se realizó mediante una encuesta, con previo consentimiento informado. Para su procesamiento y análisis, se utilizó Microsoft Excel 2016. Participaron 13 estudiantes. Según su autovaloración, adquirieron un buen nivel de destrezas en manejo de bioterio, medición de presión en ratas, histología y necropsia, y niveles menos favorables en exposición y redacción de trabajos. El 50% participaron como autores y expositores. El programa influyó en la decisión de seguir una carrera investigativa y todos consideran importante incluirlo en la currícula. Este programa muestra un impacto positivo promoviendo la incorporación temprana de estudiantes al ámbito investigativo, formándose a la par de investigadores profesionales y auxiliares estudiantiles. Su integración al plan de estudios puede incluir a todos los alumnos. Es responsabilidad educativa conectar investigación, docencia y medicina clínica, para beneficio de las personas.Fil: Gepner, Maia Einath. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Salses, Florencia Marlen del Milagro. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Alberstein, Ramón Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Sanchez, Romel Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Marañón, Rodrigo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Peral de Bruno, María. Universidad Nacional de Tucumán. Facultad de Medicina; Argentin

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    17-Octadecynoic acid improves contractile response to angiotensin II by releasing vasocontrictor prostaglandins

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    The present study investigated the role of CYP-enzymes in the modulation of vasoconstrictor responses to angiotensin II in rabbit aortae. In arteries with the endothelium-intact (E+) the CYP-inhibitor, 17-octadecynoic acid (17 ODYA), increased the efficacy to angiotensin II (17-ODYA-effect) as well as simultaneous incubation with miconazole (epoxygenase-inhibitor) and CAY 10434 (ω-hydroxylase-inhibitor). The removal of endothelium (E−) caused potentiation of the 17 ODYA-effect. Therefore, endothelium-dependent and -independent mechanisms would be involved. 17-ODYA and miconazole reduced Ach-relaxation. Indomethacin blocked the 17-ODYA-effect in E+ and E− arteries but blunted the response to angiotensin II only in E+ arteries. NS 398 (cyclooxygenase-2-inhibitor) blocked the 17-ODYA-effect and reduced angiotensin II affinity as well as SQ 29548 (thromboxane-prostanoid (TP) receptor-inhibitor). In E− arteries, CAY 10434 enhanced angiotensin II response as well as 17-ODYA. SC 560 (cyclooxygenase-1-inhibitor) and NS 398 partially blocked the 17-ODYA-effect. In conclusion, 17-ODYA induced endothelial dysfunction by inhibiting CYP-epoxygenase and thus improves vasoconstrictor cyclooxygenase-2 metabolites release acting through TP receptors. The endothelium-independent mechanism of 17-ODYA-effect may involve increase of vasoconstrictor cyclooxygenase-metabolites induced by prostaglandin-ω-hydroxylase-inhibition.Fil: Jerez S, Sierra L y Peral de Bruno M.. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Jerez, Susana Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Sierra, Liliana Beatríz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Peral de Bruno, María. Universidad Nacional de Tucumán. Facultad de Medicina; Argentin

    Vascular and autonomic function as early predictive biomarkers of the progression to gestational hypertension

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    Background: The changes in endothelial function, arterial stiffness, and heart rate variability (HRV) produced in the first trimester of pregnancy in women who develop gestational hypertension (GH) are still being investigated. Objective: to evaluate the HVR, endothelial function, and arterial stiffness changes during the first trimester of pregnancy and their relationship with the development of GH Methods: A group of women normotensive during the first trimester (n = 43), who later did (GH; n = 11) or did not (no-GH; n = 32) develop GH in that pregnancy, were enrolled. In the first trimester, endothelial function and arterial stiffness were evaluated through photoplethysmography. HRV, parasympathetic (PNS), and sympathetic (SNS) indexes were measured in a 5-minute continuous electrocardiogram record at rest sitting. The Griess reaction measured urinary nitrite excretion (NOx). Results: Systolic blood pressure (SBP) values were higher in GH (no-GH: 105.8 ± 2.0 vs. GH: 112.7 ± 3.0 mmHg; p < 0.05). Endothelial function was decreased, and arterial stiffness was increased in GH. Only in GH the arterial stiffness was correlated with SBP (Pearson’s r: 0.5594; 95%CI: 0.06106–0.8681; p < 0.05). In HRV, GH decreased low-frequency power and the ratio SD2/SD1. The inhibition of PNS was lower in GH. The NOx was reduced in GH (no-GH: 3.4 ± 0.4 vs. GH: 0.3 ± 0.1 μM/L; p < 0.001). NOx was correlated negatively with the SNS index only in GH. Conclusions: Developed GH is preceded early in pregnancy by endothelial dysfunction and increased arterial stiffness. In this context, there are SNS-PNS interrelation modifications with less inhibition of PNS

    Changes in vascular function and autonomic balance during the first trimester of pregnancy and its relationship with the new-born weight

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    This study aimed to evaluate vascular function changes and autonomic balance during the first trimester of pregnancy and its relationship with the new-born weight. This prospective study performed in pregnant (PG) women and after delivery (not pregnant: NPG) evaluated the endothelial function (EF) and arterial stiffness (AS) by a non-invasive method. We evaluated the heart rate variability (HRV), parasympathetic nervous system (PNS), sympathetic nervous system (SNS) indexes by electrocardiogram (5 min) and the urinary nitrite excretion (NOx). PG increased EF and NOx and decreased AS and HRV. PG decreased the PNS index and augmented the SNS index. The new-born weight positively correlated with the PNS index (Pearson’s r: 0.4291; p<.05), NOx, HRV and negatively correlated with AS. In summary, in pregnancy, although haemodynamically, the SNS activation plays a compensatory role, the low rates of PNS inhibition are essential to ensure normal foetal growth.Impact Statement What is already known on this subject? In pregnancy, there are adaptive physiological changes in the cardiovascular system that include increases of EF and decreases AS with an SNS activation. The study of HRV lets to predict the SNS and PNS balance and how they affect blood pressure and vascular function. What the results of this study add? Although it is known that SNS activation plays a compensatory role in healthy pregnancy, this study adds the critical role of PNS. Early in pregnancy, the low rates of PNS inhibition are essential to ensure normal foetal growth. What the implications are of these findings for clinical practice and/or further research? The present results show a potential predictive value of SNS and PNS activity early in pregnancy. It will provide valuable information not only on the pregnant woman's vascular function but also on the new-born weight
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