110 research outputs found

    Role of urinary concentrating ability in the generation of toxic papillary necrosis

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    Role of urinary concentrating ability in the generation of toxic papillary necrosis. We studied the pathogenesis of chemically induced papillary necrosis in six groups of rats. Papillary necrosis was produced by a single injection of 2-bromoethylamine hydrobromide (BEA), 50 mg, i.v.; the animals were followed for 7 to 10 days after the administration of the compound. Following BEA, heterozygous Brattleboro rats developed all the functional and morphologic lesions of papillary necrosis that we previously described in Sprague-Dawley rats. They were unable to maintain sodium balance when dietary sodium was withdrawn. Homozygous Brattleboro rats, on the other hand, developed none of the manifestations of papillary necrosis (that is, animals with central diabetes insipidus were protected completely from the nephrotoxic effects of BEA). They adapted normally to a zero sodium diet. Chronic administration of vasopressin to homozygous Brattleboro rats fully restored the toxic effects of BEA. Lowering urinary concentrating ability by inducing a water diuresis in Sprague-Dawley rats completely protected against BEA-induced papillary necrosis. Decreasing papillary solute concentration by furosemide or increasing urine flow after abrupt withdrawal of vasopressin to homozygous Brattleboro rats did not protect against BEA-induced papillary necrosis. We conclude that the combination, but not either alone, of increased urine flow and decreased papillary solute concentration protects against the development of BEA-induced papillary necrosis.Rôle du pouvoir de concentration urinaire sur l'apparition d'une nécrose papillaire toxique. Nous avons étudié la physiopathologie d'une nécrose papillaire induite chimiquement chez six groupes de rats. La nécrose papillaire était produite par une injection unique de 2-bromoéthylamine hydrobromide (BEA), 50 mg, i.v.; les animaux étaient suivis pendant 7 à 10 jours après administration du produit. Après le BEA, des rats Brattleboro hétérozygotes ont développé toutes les lésions fonctionnelles et morphologiques d'une nécrose papillaire telles que nous les avions déjà décrites chez des rats Sprague-Dawley. Ils n'étaient pas capables d'assurer l'équilibre de la balance sodée lorsque le sodium alimentaire était supprimé. Par ailleurs, des rats Brattleboro homozygotes n'ont développé aucune des manifestations de nécrose papillaire (c'est-à-dire que les animaux ayant un diabète insipide central étaient complètement protégés des effets néphrotoxiques du BEA). Ils s'adaptaient normalement à un régime sans sodium. L'administration chronique de vasopressine à des rats Brattleboro homozygotes a totalement restauré l'effet toxique du BEA. Le fait d'abaisser la capacité de concentration des urines en induisant une diurèse aqueuse dans les rats Sprague-Dawley a complètement protégé contre la nécrose papillaire induite par le BEA. La diminution de la concentration de solutés papillaires par le furosémide ou l'augmentation du débit urinaire après arrêt brutal de la vasopressine chez des rats Brattleboro homozygotes ne protégeait pas contre la nécrose papillaire induite par le BEA. Nous concluons que la combinaison, mais non chaque facteur séparément, d'une augmentation du débit urinaire et d'une diminution de la concentration de solutés papillaires protègent contre le développement d'une nécrose papillaire induite par le BEA

    Clinical and pathophysiologic spectrum of acquired distal renal tubular acidosis

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    Clinical and pathophysiologic spectrum of acquired distal renal tubular acidosis. Urinary acidification was studied in nine patients with hyper-chloremic metabolic acidosis. The aim of this study was to investigate the mechanism(s) of impaired distal acidification by the systematic administration of sodium sulfate and neutral phosphate. No impairment of proximal acidification was apparent because all patients had a fractional bicarbonate excretion below 5% at plasma bicarbonate concentrations above 22 mEq/liter. All patients except two were unable to lower urine pH below 5.5 despite systemic metabolic acidosis. The two patients who lowered urine pH normally were hyperkalemic and had selective aldosterone deficiency. Six patients failed to lower the urine pH below 5.5 with sodium sulfate (6.04 ± 0.16) and were unable to achieve a normal urine minus blood (U-B) Pco2 gradient with neutral phosphate (2.8 ± 3.5mm Hg). Control subjects, the two patients with selective aldosterone deficiency, and the remaining patient lowered the urine pH below 5.5 and increased the U-B Pco2 gradient above 25mm Hg in response to sodium sulfate and neutral phosphate infusion, respectively. The abnormal response to these agents exhibited by six patients strongly suggests that the mechanism of impaired distal acidification was that of secretory failure of the proton pump. The normal response of the remaining three patients indicates that the proton pump was able to secrete hydrogen ions normally under maximal stimulation. This pattern is totally predictable in patients with isolated selective aldosterone deficiency who are also capable of lowering the urine pH normally in the presence of systemic metabolic acidosis. The distinctive acidification pattern of the remaining patient who was also hyperkalemic can be explained on the basis of a voltage-dependent type of distal renal tubular acidosis. This type may be disclosed by the findings of impairment of both hydrogen ion and potassium secretion.Aspects clinique et physiopathologique de l'acidose tubulaire distale acquise. L'acidification urinaire a été étudiée chez neuf malades ayant une acidose métabolique hyperchlorémique. Le but de ce travail était d'étudier le mécanisme de l'altération de l'acidification distale par l'administration de sulfate de sodium et de phosphate neutre. Il n'est pas apparu d'altération de l'acidication proximale puisque tous les malades avaient une excrétion fractionnelle de bicarbonate inférieure à 5% à des concentrations de bicarbonate plasmatique supérieures à 22 mEq/litre. Tous les malades sauf deux étaient incapables d'abaisser leur pH urinaire au dessous de 5,5 malgré l'acidose métabolique. Les deux malades qui abaissaient le pH de l'urine à des valeurs normales étaient hyperkaliémiques et avaient un déficit sélectif d'aldostérone. Six malades n'ont pu abaisser leur pH urinaire en dessous de 5,5 avec le sulfate de sodium (6,04 ± 0,16) et ont été incapables de réaliser un gradient de Pco2 normal urine-sang sous phosphate neutre (2,8 ± 3,5mm Hg). Les sujets contrôles, les deux malades ayant un déficit d'aldostérone et le dernier malade ont abaissé le pH de l'urine au dessous de 5,5 et augmenté le gradient de Pco2 à plus de 25mm Hg en réponse aux administrations de sulfate de sodium et de phosphate neutre, respectivement. La résponse anormale des six malades suggère fortement que le mécanisme de l'altération de l'acidification distale est un défaut de fonctionnement de la pompe à protons. La réponse normale des trois derniers malades indique que la pompe était capable de sécréter des ions hydrogène dans des conditions de stimulation maximales. Cette modalité est prévisible chez les malades qui ont un déficit sélectif et isolé d'aldostérone et qui sont aussi capables d'abaisser le pH de leur urine en présence d'une acidose métabolique systémique. La modalité d'acidification particulière du dernier malade qui était en même temps hyperkaliémique peut être expliquée par un mécanisme dépendant de la différence de potentiel. Cette situation peut être reconnue par la constatation d'un désordre portant à la fois sur la sécrétion de ions hydrogène et celle de potassium

    Reproductibilidad de un cuestionario que valora la actividad física en adolescentes escolares

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    Introducción: Los cuestionarios de actividad física por lo general son los instrumentos más sencillos y fáciles de aplicar a grandes poblaciones, sin embargo, la capacidad de reproductibilidad varía entre las poblaciones. Objetivo: Analizar la fiabilidad de un cuestionario que valora la Actividad Física en una muestra de escolares adolescentes que viven a elevada altitud por medio de consistencia interna y test re-test. Diseño: Descriptivo-Transversal (Survey). Institución: Universidad Nacional del Altiplano, Puno, Perú. Participantes: Adolescentes escolares de 12 a 17 años. Intervenciones: Fueron seleccionados de forma sistemática 109 escolares de ambos sexos. Se valoró las medidas antropométricas de peso, estatura, estatura sentada y circunferencia del abdomen. Además se aplicó un cuestionario de actividad física con 11 preguntas (test y re-test) con un intervalo de 7 días. Principales medidas: Valoración de la capacidad de reproductibilidad por consistencia interna y estabilidad. Resultados: Los valores de alpha de Cronbach (Consistencia interna) mostraron valores de 0,73 a 0,77 para ambos sexos. El Error Técnico de Medida (ETM) fue de 0,50 a 1,61% y el coeficiente de correlación de Spearman  osciló entre 0,91 a 0,95. Conclusión: El cuestionario de actividad física muestra altos valores de confiabilidad, tanto en su consistencia interna como en la estabilidad de las medidas. Introduction: Physical activity questionnaires usually are the most simple and easy to apply to large populations, however, reproducibility capacity varies between populations. Objective: To analyze the reliability of a questionnaire to assess physical activity in a sample of school adolescents living at high altitude through internal consistency and test re-test. Design: Descriptive, transversal (Survey). Institution: Universidad Nacional del Altiplano, Puno, Peru. Participants: School Teens 12 to 17 years. Interventions: There were systematically selected 109 students of both sexes. We evaluated anthropometric measurements of weight, height, sitting height and circumference of the abdomen. In addition we applied a physical activity questionnaire with 11 questions (test and re-test) with an interval of 7 days. Main measures: capacity rating for internal consistency, reproducibility and stability. Results: Cronbach's alpha values ??(internal consistency) showed values ??from 0.73 to 0.77 for both sexes. Measuring technical error (SEM) was from 0.50 to 1.61% and the Spearman correlation coefficient ranges from 0.91 to 0.95. Conclusion: The physical activity questionnaire shows high values ??of reliability, consistency both internally and in the stability of the measures

    Cardiac and vascular changes in elderly atherosclerotic mice: the influence of gender

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    <p>Abstract</p> <p>Background</p> <p>Although advanced age is considered a risk factor for several diseases, the impact of gender on age-associated cardiovascular diseases, such as atherosclerotic processes and valvular diseases, remains not completely clarified. The present study was designed to assess aortic valve morphology and function and vascular damage in elderly using the apolipoprotein E knockout (ApoE KO) mouse. Our hypothesis was that advanced age-related cardiovascular changes are aggravated in atherosclerotic male mice.</p> <p>Methods</p> <p>The grade (0 to 4) of aortic regurgitation was evaluated through angiography. In addition, vascular lipid deposition and senescence were evaluated through histochemical analyses in aged male and female ApoE KO mice, and the results were compared to wild-type C57BL/6J (C57) mice.</p> <p>Results</p> <p>Aortic regurgitation was observed in 92% of the male ApoE KO mice and 100% of the male C57 mice. Comparatively, in age-matched female ApoE KO and C57 mice, aortic regurgitation was observed in a proportion of 58% and 53%, respectively. Histological analysis of the aorta showed an outward (positive) remodeling in ApoE KO mice (female: 1.86 ± 0.15; male: 1.89 ± 0.68) using C57 groups as reference values. Histochemical evaluation of the aorta showed lipid deposition and vascular senescence only in the ApoE KO group, which were more pronounced in male mice.</p> <p>Conclusion</p> <p>The data show that male gender contributes to the progression of aortic regurgitation and that hypercholesterolemia and male gender additively contribute to the occurrence of lipid deposition and vascular senescence in elderly mice.</p

    Clinical outcome of renal transplant patients after coronary stenting

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    OBJECTIVE: To assess the clinical outcome of renal transplant patients who developed coronary artery disease and were treated with coronary stenting (TCA-ST). METHODS: A total of 3,334 renal transplants were performed in our service - Hospital do Rim e Hipertensão - HRH (Kidney and Hypertension Hospital) from July, 1998 to November, 2004. During this period, 33 of the renal transplant patients underwent TCA-ST to treat 62 severe stenoses in 54 coronary arteries. A retrospective analysis was performed with renal transplant patients undergoing TCA-ST at HRH. The clinical events were registered using medical charts, medical visits and phone calls. RESULTS: During the 30-month clinical follow-up after TCA-ST, 67% of the patients remained asymptomatic, 18% presented stable angina, 6% presented acute coronary syndrome without ST-segment elevation (ACSWSTE), and 3% presented acute coronary syndrome with ST-segment elevation (ACSSTE). No strokes, CHF or cardiac deaths were observed. Three non-cardiac deaths occurred. A restenosis rate of 9% was observed, which is comparable to those found in studies on drug-eluting stents. CONCLUSION: In conclusion, renal transplant patients who developed CAD and were treated with coronary stenting had a low rate of in-stent restenosis, probably related to the immunosuppressive regimen given to prevent kidney rejection.OBJETIVO: Avaliar a evolução clínica de pacientes submetidos a transplante de rim, portadores de doença arterial coronariana, que foram tratados com implante de stent coronariano (ATC-ST). MÉTODOS: Entre julho de 1998 e novembro de 2004, foram realizados, no total, 3.334 transplantes de rim em nossa Instituição (Hospital do Rim e Hipertensão). Desse total, 33 pacientes previamente submetidos a transplante de rim fizeram ATC-ST para o tratamento de 62 estenoses graves em 54 artérias coronárias, nos quais foi realizada análise retrospectiva. O registro dos eventos clínicos foi feito por meio de análise do prontuário médico, consulta médica e ligações telefônicas. RESULTADOS: No seguimento clínico de 30 meses, após a ATC-ST, observou-se que 67% dos pacientes permaneceram assintomáticos, 18% dos pacientes apresentaram quadro de angina estável, 6% apresentaram síndrome coronariana aguda sem supra de ST e 3% apresentaram síndrome coronariana aguda com supra de ST. Não houve pacientes com acidente vascular cerebral, insuficiência cardíaca congestiva ou morte cardíaca. Houve três mortes não-cardíacas. Foi observado índice de reestenose de 9%, que é comparável ao dos estudos de stent farmacológico. CONCLUSÃO: Concluímos que pacientes submetidos a transplante de rim que desenvolveram doença arterial coronariana e que foram tratados com stent coronariano tiveram baixo porcentual de reestenose clínica, provavelmente relacionado ao regime de imunossupressão administrado para evitar rejeição renal.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Hospital do Rim e HipertensãoUNIFESP, EPM, Hospital do Rim e HipertensãoSciEL

    Sustainability in the business context: Contributions of product design.

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    O trabalho objetivou desenvolver um artefato eco eficiente para um negócio sustentável, para isto, foi necessário realizar um estudo sobre aspectos da sustentabilidade, interligando estes a movimentos da cultura DIY e minimalista. Esses estudos culturais relacionados ao tema, mostraram-se de suma importância para a realização do artefato final, que traz como principais características elementos da estética sustentável e referências destas culturas. Dentro do universo e premissas sustentáveis, a escolha foi desenvolver um artefato para foodbike, direcionada ao público ambulante, sendo uma alternativa econômica aos microempreendedores. A matéria prima escolhida – palete – teve uma relevância importante para economia local, uma vez que se trata de um material de reutilização, com ótimas qualidades mecânicas, aspecto primordial para confecção do artefato final. Ao trabalhar materiais com grande potêncial para ressignificação, foi necessário perceber que a cada passagem uma nova estética surge aos olhos dos consumidores.The objective of the work was to develop an eco-efficient artefact for a sustainable business, for this, it was necessary to carry out a study on aspects of sustainability, interconnecting these to movements of the DIY and minimalist culture. These cultural studies related to the theme have proved to be of utmost importance for the final artifact, which brings as main characteristics elements of sustainable aesthetics and references of these cultures. Within the universe and sustainable premises, the choice was to develop an artifact for foodbike, aimed at the traveling public, being an economic alternative to microentrepreneurs. The chosen raw material - pallet - had an important relevance for local economy, since it is a material of reutilization, with excellent mechanical qualities, primordial aspect for confection of the final artifact. When working materials with great potential for re-signification, it was necessary to realize that at each passage a new aesthetic appears in the eyes of the consumers

    Plant microbiomes harbor potential to promote nutrient turnover in impoverished substrates of a Brazilian biodiversity hotspot.

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    The substrates of the Brazilian campos rupestres, a grassland ecosystem, have extremely low concentrations of phosphorus and nitrogen, imposing restrictions to plant growth. Despite that, this ecosystem harbors almost 15% of the Brazilian plant diversity, raising the question of how plants acquire nutrients in such a harsh environment. Here, we set out to uncover the taxonomic profile, the compositional and functional differences and similarities, and the nutrient turnover potential of microbial communities associated with two plant species of the campos rupestres-dominant family Velloziaceae that grow over distinct substrates (soil and rock). Using amplicon sequencing data, we show that, despite the pronounced composition differentiation, the plant-associated soil and rock communities share a core of highly efficient colonizers that tend to be highly abundant and is enriched in 21 bacterial families. Functional investigation of metagenomes and 522 metagenome-assembled genomes revealed that the microorganisms found associated to plant roots are enriched in genes involved in organic compound intake, and phosphorus and nitrogen turnover. We show that potential for phosphorus transport, mineralization, and solubilization are mostly found within bacterial families of the shared microbiome, such as Xanthobacteraceae and Bryobacteraceae. We also detected the full repertoire of nitrogen cycle-related genes and discovered a lineage of Isosphaeraceae that acquired nitrogen-fixing potential via horizontal gene transfer and might be also involved in nitrification via a metabolic handoff association with Binataceae. We highlight that plant-associated microbial populations in the campos rupestres harbor a genetic repertoire with potential to increase nutrient availability and that the microbiomes of biodiversity hotspots can reveal novel mechanisms of nutrient turnover.Online first

    The clinical use of circulating tumor cells (CTCs) enumeration for staging of metastatic breast cancer (MBC): International expert consensus paper

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    BACKGROUND: The heterogeneity of metastatic breast cancer (MBC) necessitates novel biomarkers allowing stratification of patients for treatment selection and drug development. We propose to use the prognostic utility of circulating tumor cells (CTCs) for stratification of patients with stage IV disease. METHODS: In a retrospective, pooled analysis of individual patient data from 18 cohorts, including 2436 MBC patients, a CTC threshold of 5 cells per 7.5\u2009ml was used for stratification based on molecular subtypes, disease location, and prior treatments. Patients with 65 5 CTCs were classified as Stage IVaggressive, those with < 5 CTCs as Stage IVindolent. Survival was analyzed using Kaplan-Meier curves and the log rank test. RESULTS: For all patients, Stage IVindolent patients had longer median overall survival than those with Stage IVaggressive (36.3 months vs. 16.0 months, P\u2009<\u20090.0001) and similarly for de novo MBC patients (41.4 months Stage IVindolent vs. 18.7 months Stage IVaggressive, p\u2009<\u20090.0001). Moreover, patients with Stage IVindolent disease had significantly longer overall survival across all disease subtypes compared to the aggressive cohort: hormone receptor-positive (44 months vs. 17.3 months, P\u2009<\u20090.0001), HER2-positive (36.7 months vs. 20.4 months, P\u2009<\u20090.0001), and triple negative (23.8 months vs. 9.0 months, P\u2009<\u20090.0001). Similar results were obtained regardless of prior treatment or disease location. CONCLUSIONS: We confirm the identification of two subgroups of MBC, Stage IVindolent and Stage IVaggressive, independent of clinical and molecular variables. Thus, CTC count should be considered an important tool for staging of advanced disease and for disease stratification in prospective clinical trials
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