INJECTABLE HYBRID SYSTEM FOR STRONTIUM LOCAL DELIVERY TO PROMOTE BONE REGENERATION

In bone tissue regeneration strategies, injectable bone substitutes are very attractive since they can be applied with minimally invasive surgical procedures and can perfectly fill irregular defects created in cases of trauma, infection or tumor resection. These materials must combine adequate mechanical properties with the ability to induce new bone formation. Incorporating strontium (Sr) in bone substitute biomaterials may be a strategy to achieve high Sr concentrations, not in a systemic but in a local environment, taking advantage of the osteoanabolic and anti-osteoclastic activity of Sr, for the enhancement of new bone formation. In this context, the aim of the present work was to evaluate the response of a Sr-hybrid injectable system for bone regeneration, designed by our group, consisting of hydroxyapatite microspheres doped with Sr and an alginate vehicle crosslinked in situ with Sr, in an in vivo scenario. Two different animal models were used, rat (Wistar) and sheep (Merino Branco) critical sized bone defect. Non Sr-doped similar materials (Ca-hybrid) or empty defects were used as control. Sr-hybrid system led to an increased bone formation in both center and periphery of a rat critical sized defect compared to a non Sr–doped similar system, where new bone formation was restricted to the periphery. Moreover newly formed bone was identified as early as one week after its implantation in a sheep model. After eight weeks, the bone surrounded the microspheres, both in the periphery and in the center of the defect. Most importantly, the hybrid system provided a scaffold for cell migration and tissue ingrowth and offered structural support, as observed in both models. The effective improvement of local bone formation suggests that this might be a promising approach for bone regeneration, especially in osteoporotic conditions

Resposta da amendoeira a diferentes estratégias de rega na região de Trás-os-Montes: rendimento e eficiência do uso da água

Nas regiões de clima mediterrânico onde a amendoeira tem uma grande expressão em termos de área cultivada e importância económica, as secas sazonais que ocorrem durante parte do seu ciclo vegetativo são frequentes e responsáveis por quebras elevadas do rendimento. Apesar de a amendoeira ser uma espécie tolerante à seca, não há dúvidas de que a rega é um factor crítico para o aumento da produtividade e qualidade da amêndoa. As limitações em termos de disponibilidade de água, que tenderão a agravar-se no contexto das alterações climáticas, obrigarão os produtores a lidar com a escassez de água através da implementação de estratégias de rega deficitária que conduzam a um aumento da eficiência do uso da água.Este trabalho foi realizado no âmbito do projeto PRODER 54610 - Estratégias integradas para o aumento da produtividade da amendoeira em Trás-os-Montes, financiado pelo Programa de Desenvolvimento Rural (PRODER) no âmbito da medida 4.1 - Cooperação para a Inovação (Apoio à Inovação na Agricultura, Agroindústria e Floresta).info:eu-repo/semantics/publishedVersio

Calcium phosphate-alginate microspheres as enzyme delivery matrices

The present study concerns the preparation and initial characterisation of novel calcium titanium phosphate-alginate (CTPalginate) and hydroxyapatite-alginate (HAp-alginate) microspheres, which are intended to be used as enzyme delivery matrices and bone regeneration templates. Microspheres were prepared using different concentrations of polymer solution (1% and 3% w/v) and different ceramic-to-polymer solution ratios (0.1, 0.2 and 0.4 w/w). Ceramic powders were characterised using X-ray diffraction, laser granulometry, Brunauer, Emmel and Teller (BET) method for the determination of surface area, zeta potential and Fourier transform infrared spectroscopy (FT-IR). Alginate was characterised using high performance size exclusion chromatography. The methodology followed in this investigation enabled the preparation of homogeneous microspheres with a uniform size. Studies on the immobilisation and release of the therapeutic enzyme glucocerebrosidase, employed in the treatment of Gaucher disease, were also performed. The enzyme was incorporated into the ceramic-alginate matrix before gel formation in two different ways: preadsorbed onto the ceramic particles or dispersed in the polymeric matrix. The two strategies resulted in distinct release profiles. Slow release was obtained after adsorption of the enzyme to the ceramic powders, prior to preparation of the microspheres. An initial fast release was achieved when the enzyme and the ceramic particles were dispersed in the alginate solution before producing the microspheres. The latter profile is very similar to that of alginate microspheres. The different patterns of enzyme release increase the range of possible applications of the system investigated in this work.info:eu-repo/semantics/publishedVersio

IN VIVO STUDY OF THE EFFECT OF A STRONTIUM-­‐RICH INJECTABLE SYSTEM ON BONE REGENERATION, USING A SHEEP MODEL

Bone has the capacity to regenerate as part of the repair process,being newly formed boné indistinguishable from the adjacente uninjured bone. However,there are cases in which boné regeneration is required in large quantity, beyond the normal potential for self-­‐healing, such as for lesions caused by trauma, infection, tumour resection or cases in which the regenerative process is compromised such as avascular necrosis and osteoporosis. Biomaterials such as alginate are very promising due to its ability to form hydrogels in situ under mild conditions in the presence of divalente cations. The combination with ceramic microspheres results in a mechanically improved injectable system, adequate for minimally invasive procedures. Moreover, the combination with chemical elements such as strontium, described as promoter of boné formation, inhibiting boné resorption provides ion Exchange between the implanted biomaterial and surrounding tissue, enhancing boné regeneration. Our goal is to study in na invivo sheep model, the effect of na injectable system composed of strontium doped hydroxyapatite microspheres, delivered in na alginate vehicle, crosslinked with strontium

Nutritional status and use of drugs by elders

O aumento da freqüência das doenças crônico-degenerativas associadas ao envelhecimento implica, muitas vezes, no uso contínuo de fármacos. Paralelamente, os idosos são mais propensos a alterações nutricionais, devido a distintos fatores. De acordo com a literatura, as alterações nutricionais com influência potencial no efeito de um maior número de fármacos são as mudanças na concentração de proteínas plasmáticas -hipoalbuminemia e alterações na α-glicoproteína ácida e na composição corporal. Tais alterações podem modificar os efeitos de agentes sedativos, cardiovasculares, diuréticos, entre outros. A consideração desses aspectos é fundamental para melhorar o uso de medicamentos entre idosos.The frequency increase of chronic degenerative diseases associated with elderly usually implies the continuous use of medicines. Elders are more prone to nutritional changes as a function of different factors. According to the literature, the nutritional changes with potential influence in the effect of most drugs are the modification in the concentration of plasmatic proteins -hypoalbuminemia and acid α-1-glycoprotein-, and in the body composition. Such alterations may modify the effects of sedative, cardiovascular agents, anticonvulsives, and diuretics, among others. Consideration of these aspects is a basic condition to improve the use of medicines among elderly people.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Combined soil and foliar nitrogen fertilization effects on rainfed almond tree performance

Cultivation of almond in the Mediterranean region is traditionally done under rainfed conditions and poorly established cropping practices resulting in low yields. Despite the importance of nitrogen (N) fertilization to increase yield in cultivated species, this practice is usually neglected in rainfed managed almond orchards. Selection of the most appropriate rate and method of nitrogen (N) application are utmost factors to maximize almond yield in the considered conditions. Therefore, the aim of this study was to understand how soil and foliar N fertilization affect physiological and biochemical performance, almond yield, and fruit quality of almond trees grown under rainfed conditions. A 3-year experiment comprised four soil-applied N rates (0, 25, 50, and 100 kg ha−1) with and without 0.5% foliar N application of urea during the growing season, which was arranged in a randomized complete block design with three replications. Nitrogen soil fertilization did not influence the leaf gas exchange parameters and the content of photosynthetic pigments but significantly improved almond yield. There were no particular advantages in foliar fertilization. Soil application of small doses of fertilizer (e.g., 25 kg N ha−1) per year was optimal for maintaining appropriate physiological behavior of almond trees under the conditions in which the experiment was carried out, without compromise almond yield and fruit quality. Thus, the annual application at 25 kg N ha−1 enables substantial reduction of almond production costs being a positive contribution to environment-friendly farming practices.The authors acknowledge the financial support of the European Agricultural and Rural development fund (FEADER) under the Project “Estratégias Integradas para o aumento da produtividade da amendoeira em Trás-os-Montes n° 54611,” and by Portuguese State through the “Medida 4.1. Cooperação para a Inovação do programa PRODER - Programa de Desenvolvimento Rural.” Maria Morais, Alfredo Aires, Berta Gonçalves, and Ana Silva acknowledge the support of the National Funds by FCT—Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2020. David Barreales, Manuel Rodrigues, and António Ribeiro are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UID/AGR/00690/2018). The authors are also grateful to Ana Monteiro, Cristiana Teixeira, Iva Prgomet, Ivo Oliveira, Linton Dinis, Sara Bernardo, Sílvia Afonso, and Silvina Morais for their support in the field and in the laboratory.info:eu-repo/semantics/publishedVersio

Evidence towards the involvement of nitric oxide in drought tolerance of sugarcane

© 2017 Elsevier Masson SAS Exogenous supply of nitric oxide (NO) increases drought tolerance in sugarcane plants. However, little is known about the role of NO produced by plants under water deficit. The aim of this study was to test the hypothesis that drought-tolerance in sugarcane is associated with NO production and metabolism, with the more drought-tolerant genotype presenting higher NO accumulation in plant tissues. The sugarcane genotypes IACSP95-5000 (drought-tolerant) and IACSP97-7065 (drought-sensitive) were submitted to water deficit by adding polyethylene glycol (PEG-8000) in nutrient solution to reduce the osmotic potential to−0.4MPa. To evaluate short-time responses to water deficit, leaf and root samples were taken after 24h under water deficit. The drought-tolerant genotype presented higher root extracellular NO content, which was accompanied by higher root nitrate reductase (NR) activity as compared to the drought-sensitive genotype under water deficit. In addition, the drought-tolerant genotype had higher leaf intracellular NO content than the drought-sensitive one. IACSP95-5000 exhibited decreases in root S-nitrosoglutathione reductase (GSNOR) activity under water deficit, suggesting that S-nitrosoglutathione (GSNO) is less degraded and that the drought-tolerant genotype has a higher natural reservoir of NO than the drought-sensitive one. Those differences in intracellular and extracellular NO contents and enzymatic activities were associated with higher leaf hydration in the drought-tolerant genotype as compared to the sensitive one under water deficit

The effects of improving low dietary protein utilization on the proteome of lamb tissues

Cistus ladanifer L. is a common shrub endemic to the Mediterranean region with high levels of condensed tannins (CT). CT form complexes with dietary protein resisting microbial degradation in the rumen, which enhances dietary protein utilization in ruminant diets. The objective of this study was to evaluate the utilization of CT in the diet of lambs on the proteomes of muscle, hepatic and adipose tissues. Twenty-four Merino Branco ram lambs were randomly allocated to three treatments (n = 8): C – control (160 g crude protein (CP)) per kg DM, RP – reduced protein (120 g CP/kg DM); and RPCT – reduced protein (120 g CP/kg DM) treated with CT extract. At the end of the trial, lambs were slaughtered and the longissimus lumborum muscle, hepatic and peri-renal adipose tissues sampled. A two-way approach was used for proteomic analysis: 2D-DIGE and nanoLC-MS. In the muscle, C lambs had lower abundance proteins that partake in the glycolysis pathway than the lambs of other treatments. Control lambs had lower abundance of Fe-carrying proteins in the hepatic tissue than RP and RPCT lambs. The latter lambs had highest abundance of hepatic flavin reductase. In the adipose tissue, C lambs had lowest abundance of fatty-acid synthaseinfo:eu-repo/semantics/acceptedVersio

Physiological and biochemical performance of almond trees under deficit irrigation

The almond tree is generally recognized as drought-tolerant, though it depends on water resources to achieve high yields. During the summer months of two consecutive years, several physiological and biochemical parameters were observed, to understand the almond tree’s seasonal sensitivity and behavior under different irrigation strategies based on crop evapotranspiration (ETc): T100 optimal water requirement regime (applying 100% ETc); T70 and T35 sustained deficit irrigation regimes (applying 70% and 35% ETc); T100-35 regulated deficit irrigation regime (reducing the application to 35% ETc during fruit filling stage); and T0 (rainfed). The total leaf chlorophyll and carotenoid reduction in T0 and T35 treatments was significant compared to T100-35. Leaf soluble proteins and total soluble sugar contents were significantly higher in non-irrigated trees compared to other treatments, while the starch content showed the opposite trend. Rainfed trees were under obvious water stress, displaying the lowest values for relative water content (RWC), stomatal conductance (gs), photosynthetic rate (A), and transpiration rate (E), and the highest for intrinsic water use efficiency (A/gs). Plant hormones (ABA and IAA) generally accumulated more in non-irrigated trees. The almond tree has been confirmed as a drought-tolerant species, and when water is scarce, reducing the water application to 35% ETc during fruit filling stage, results in no yield losses, and the plant status remains unstressed. However, to get the maximum crop potential, in years and areas where water is not restricted, full irrigation requirements have been shown to boost almond tree performance.IP acknowledges the financial support provided by the FCTPortuguese Foundation for Science and Technology (SFRH/BD/52539/ 2014), under the Doctoral Programme “Agricultural Production Chains – from fork to farm” (PD/00122/2012). This work was also supported by National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2019 and by the project PRODER “Estratégias Integradas para o aumento da produtividade da amendoeira em Trás-os-Montes, nº 54611. 2014 a 2018. The authors wish to acknowledge the help and support provided during field and laboratory work by Ana Monteiro, Cristiana Teixeira, Helena Ferreira, Ivo Oliveira, Linton Dinis, Sara Bernardo, Silvia Afonso, and Silvina Morais, and thank João Santos and Chenyao Yang for help with climate data.info:eu-repo/semantics/publishedVersio