Renin-angiotensin-aldosterone system (RAAS) and its pharmacologic modulation

O sistema-renina-angiotensina-aldosterona (SRAA) é um sistema neuroendócrino complexo responsável pela modulação do equilíbrio hidroelectrolítico e regulação da pressão arterial. Através das suas múltiplas interacções contribui para a protecção do tecido endotelial, cardíaco, cerebral e renal. Adicionalmente, regula ainda a resposta do endotélio à inflamação e lesão. A sua activação crónica/desregulação induz hipertensão e perpetuação de uma cascata pró-inflamatória, pró-trombótica e aterogénica, que está na base da lesão de vários órgãos-alvo (coração, cérebro, rim, endotélio). Consequentemente, o SRAA constitui um alvo terapêutico importante nestas situações. O artigo aborda a fisiologia, patofisiologia e mecanismos de modulação farmacológica do SRAA. The renin-angiotensin-aldosterone system (RAAS) is a neuroendocrine complex system that regulates the modulation of salt and water homeostasis, and regulation of blood pressure. Through its multiple interactions it protects the endothelium, heart, brain and kidney. In addition, the RAAS regulates the vascular response to injury and inflammation. Chronic activation/dysregulation of the RAAS leads to hypertension and perpetuates a cascade of proinflammatory, prothrombotic and atherogenic effects associated with endorgan damage (heart, brain, kidney, endothelium). Consequently, the RAAS is an important therapeutic target in these situations. This article presents an overview of physiology, pathophysiology and pharmacologic modulation of the RAAS

Thermal energy production by a dual solar pound

A Salt Gradient Solar Pond (SGSP) is a salt water basin that collects and stores solar energy. These devices rely on the existence of a non-convective zone (NCZ) that functions as a transparent thermal insulation zone, created by a salt gradient. Salinity and temperature gradients in this zone can give rise to double diffusive problems that can decrease the insulation properties of this zone. The stability of this zone is thus crucial in a SGSP. Stability control, analysis of energy extraction, device efficiency and maintenance strategies are determinant for the correct performance of the SGSP. The implementation of these strategies can be expensive and not sufficient to prevent instability problems. This paper intends to give a contribution to the maintenance problem presenting a new concept of a SGSP utilisation: The Dual Solar Pond (DSP

Abordagem da hipertrigliceridemia severa na gravidez: a propósito de um caso clínico

RESUMO Durante a gravidez o metabolismo lipídico é afectado pelas hormonas placentárias de modo a assegurar um adequado aporte nutricional para o feto, constatando-se um aumento fisiológico dos níveis de triglicerídeos (TG), em particular no terceiro trimestre. Se o aumento do valor dos triglicerídeos for superior ao esperado na gravidez a paciente deve ser cuidadosamente monitorizada. A principal complicação da hipertrigliceridemia severa é a pancreatite aguda que está associada a uma mortalidade materno-fetal elevada (20%). Os autores apresentam o caso de uma mulher de 31 anos, com gestação de 34 semanas e hipertrigliceridemia severa (TG=1127 mg/dl). Foi internada e submetida a dieta pobre em gorduras, suplementos de ácidos gordos ómega 3 e a apertada vigilância clínica e analítica. O parto decorreu às 37 semanas de gestação sem complicações. O recém-nascido, do sexo feminino, pesava 3220 g e o score Apgar era de 9 ao primeiro minuto. Após o parto os níveis de TG maternos mostraram uma redução marcada. Este caso ilustra a importância do diagnóstico precoce e da instituição de medidas estratégicas relativamente simples na prevenção de pancreatite aguda em grávidas com hipertrigliceridemia severa

Accuracy of faecal calprotectin and neutrophil Gelatinase B-associated Lipocalin in evaluating subclinical inflammation in UlceRaTIVE colitis-the ACERTIVE study

Background and Aims: Mucosal healing and histological remission are different targets for patients with ulcerative colitis, but both rely on an invasive endoscopic procedure. This study aimed to assess faecal calprotectin and neutrophil gelatinase B-associated lipocalin as biomarkers for disease activity in asymptomatic ulcerative colitis patients. Methods: This was a multicentric cross-sectional study including 371 patients, who were classified according to their endoscopic and histological scores. These results were evaluated alongside the faecal levels of both biomarkers. Results: Macroscopic lesions [i.e. endoscopic Mayo score >= 1] were present in 28% of the patients, and 9% had active disease according to fht Ulcerative Colitis Endoscopic Index of Severity. Moreover, 21% presented with histological inflammation according to the Geboes index, whereas 15% and 5% presented with focal and diffuse basal plasmacytosis, respectively. The faecal levels of calprotectin and neutrophil gelatinase B-associated lipocalin were statistically higher for patients with endoscopic lesions and histological activity. A receiver operating characteristic-based analysis revealed that both biomarkers were able to indicate mucosal healing and histological remission with an acceptable probability, and cut-off levels of 150-250 mu g/g for faecal calprotectin and 12 mu g/g for neutrophil gelatinase B-associated lipocalin were proposed. Conclusions: Faecal calprotectin and neutrophil gelatinase B-associated lipocalin levels are a valuable addition for assessment of disease activity in asymptomatic ulcerative colitis patients. Biological levels of the analysed biomarkers below the proposed thresholds can rule out the presence of macroscopic and microscopic lesions with a probability of 75-93%. However, caution should be applied whenever interpreting positive results, as these biomarkers present consistently low positive predictive values.Portuguese IBD Group [GEDII - Grupo de Estudo da Doenca Inflamatcria Intestinal]info:eu-repo/semantics/publishedVersio