Different Factors Affecting Human ANP Amyloid Aggregation and Their Implications in Congestive Heart Failure

Atrial Natriuretic Peptide (ANP)-containing amyloid is frequently found in the elderly heart. No data exist regarding ANP aggregation process and its link to pathologies. Our aims were: i) to experimentally prove the presumptive association of Congestive Heart Failure (CHF) and Isolated Atrial Amyloidosis (IAA); ii) to characterize ANP aggregation, thereby elucidating IAA implication in the CHF pathogenesis.A significant prevalence (85\%) of IAA was immunohistochemically proven ex vivo in biopsies from CHF patients. We investigated in vitro (using Congo Red, Thioflavin T, SDS-PAGE, transmission electron microscopy, infrared spectroscopy) ANP fibrillogenesis, starting from α-ANP as well as the ability of dimeric β-ANP to promote amyloid formation. Different conditions were adopted, including those reproducing β-ANP prevalence in CHF. Our results defined the uncommon rapidity of α-ANP self-assembly at acidic pH supporting the hypothesis that such aggregates constitute the onset of a fibrillization process subsequently proceeding at physiological pH. Interestingly, CHF-like conditions induced the production of the most stable and time-resistant ANP fibrils suggesting that CHF affected people may be prone to develop IAA.We established a link between IAA and CHF by ex vivo examination and assessed that β-ANP is, in vitro, the seed of ANP fibrils. Our results indicate that β-ANP plays a crucial role in ANP amyloid deposition under physiopathological CHF conditions. Overall, our findings indicate that early IAA-related ANP deposition may occur in CHF and suggest that these latter patients should be monitored for the development of cardiac amyloidosis

Avaliação do uso de farinha de pena como coadjuvante proteico na preparação de combi-CLEAS aplicados à clarificação do suco de uva

Durante a fabricação de suco de uva, enzimas pectinolíticas são utilizadas na etapa de clarificação a fim de reduzir viscosidade e turbidez, melhorando o aspecto visual do suco. Os preparados enzimáticos comerciais utilizados se apresentam na forma de mistura de diferentes enzimas, como pectinases, celulases e hemicelulases, que atuam de forma sinérgica para melhor hidrolise de diferentes polissacarídeos, responsáveis pela turbidez em sucos. A imobilização dessas enzimas pode conferir um aumento na eficiência desse processo. Neste caso, agregados enzimáticos entrecruzados (CLEAs) são uma alternativa para imobilização de enzimas sem o uso de suporte físico. A farinha de pena é um resíduo industrial rico em proteína bruta. Assim, o objetivo deste trabalho foi a preparação de combi-CLEAs utilizando farinha de pena como coadjuvante proteico para aplicação na etapa de clarificação do suco de uva. Inicialmente, foi realizada a seleção do agente precipitante, no qual quatro solventes orgânicos foram utilizados sendo selecionado o etanol. Na sequência, as condições ótimas de tempo, concentração de agente entrecruzante e preparado enzimático foram determinados através de planejamento fatorial 23. A partir dos dados obtidos, foram estabelecidas como condições ótimas 5 h de reação, 110 mM de glutaraldeído e 0,66 mg.mL-1 de proteína, com as quais foi obtida uma atividade recuperada de 5,1%. O efeito de adição de albumina de soro bovino (BSA) e farinha de pena (FP) na preparação de combi-CLEAs foi avaliado, sob as condições ótimas pré-estabelecidas. Desta forma, 10 % de atividade foi recuperada com adição de 4,6 mg.mL-1 de FP e 5 % com adição de 0,66 mg.mL-1 de BSA. Por fim, foram determinadas as condições ótimas de pH e temperatura, estabilidade térmica e operacional e eficiência de clarificação. A FP teve um efeito positivo na recuperação da atividade, estabilidade térmica e eficiência de clarificação. BSA teve efeito positivo na estabilidade térmica e operacional. Próximos estudos podem ser feitos com a adição combinada de FP e BSA, a fim de obter um efeito potencializado

Reduced insulin sensitivity as a marker for acute mountain sickness?

Spliethoff, Kerstin, Daniela Meier, Isabelle Aeberli, Max Gassmann, Wolfgang Langhans, Marco Maggiorini, Thomas A. Lutz, and Oliver Goetze. Reduced insulin sensitivity as a marker for acute mountain sickness? High Alt Med Biol 14:240–250, 2013—Reduced insulin sensitivity might increase the susceptibility to acute mountain sickness (AMS). The diabetogenic side effects of dexamethasone should therefore be considered for AMS treatment. To examine whether reduced insulin sensitivity is predictive of AMS and how it is affected by dexamethasone at high altitude, we analyzed endocrine and metabolic parameters obtained from healthy mountaineers in Zurich (LA; 490 m), and 2 and 4 days after fast ascent to the Capanna Regina Margherita (HA2, HA4; 4559 m). 14 of 25 participants developed AMS and were treated with dexamethasone starting in the evening of HA2. Before and after ingestion of an 1800 kJ meal, plasma was analyzed for erythropoietin (EPO) and cholecystokinin (CCK). Insulin sensitivity (HOMA-S) and beta cell activity were calculated. HOMA-S (p<0.01) and EPO levels (p<0.05) were lower in Zurich in the group developing AMS and given dexamethasone, i.e., before treatment and exposure to hypoxia. CCK was lower (p<0.01) and glucose and insulin were higher on HA4 in the dexamethasone group compared to the untreated group. Individuals with low baseline insulin sensitivity and low baseline EPO levels were more susceptible to AMS. Reduced CCK may contribute to the beneficial effect of dexamethasone on high altitude anorexia. However, reduced insulin sensitivity questions the widespread use of dexamethasone to prevent/treat AMS

Table 2 Overview of the established BIOTA Observatories in Africa & Appendix

The international, interdisciplinary biodiversity research project BIOTA AFRICA initiated a standardized biodiversity monitoring network along climatic gradients across the African continent. Due to an identified lack of adequate monitoring designs, BIOTA AFRICA developed and implemented the standardized BIOTA Biodiversity Observatories, that meet the following criteria (a) enable long-term monitoring of biodiversity, potential driving factors, and relevant indicators with adequate spatial and temporal resolution, (b) facilitate comparability of data generated within different ecosystems, (c) allow integration of many disciplines, (d) allow spatial up-scaling, and (e) be applicable within a network approach. A BIOTA Observatory encompasses an area of 1 km2 and is subdivided into 100 1-ha plots. For meeting the needs of sampling of different organism groups, the hectare plot is again subdivided into standardized subplots, whose sizes follow a geometric series. To allow for different sampling intensities but at the same time to characterize the whole square kilometer, the number of hectare plots to be sampled depends on the requirements of the respective discipline. A hierarchical ranking of the hectare plots ensures that all disciplines monitor as many hectare plots jointly as possible. The BIOTA Observatory design assures repeated, multidisciplinary standardized inventories of biodiversity and its environmental drivers, including options for spatial up- and downscaling and different sampling intensities. BIOTA Observatories have been installed along climatic and landscape gradients in Morocco, West Africa, and southern Africa. In regions with varying land use, several BIOTA Observatories are situated close to each other to analyze management effects