ECM-enriched alginate hydrogels for bioartificial pancreas: an ideal niche to improve insulin secretion and diabetic glucose profile

Introduction: The success of a bioartificial pancreas crucially depends on ameliorating encapsulated beta cells survival and function. By mimicking the cellular in vivo niche, the aim of this study was to develop a novel model for beta cells encapsulation capable of establishing an appropriate microenvironment that supports interactions between cells and extracellular matrix (ECM) components. Methods: ECM components (Arg-Gly-Asp, abbreviated as RGD) were chemically incorporated in alginate hydrogels (alginate-RGD). After encapsulation, INS-1E beta cells outcome was analyzed in vitro and after their implantation in an animal model of diabetes. Results: Our alginate-RGD model demonstrated to be a good in vitro niche for supporting beta cells viability, proliferation, and activity, namely by improving the key feature of insulin secretion. RGD peptides promoted cell–matrix interactions, enhanced endogenous ECM components expression, and favored the assembly of individual cells into multicellular spheroids, an essential configuration for proper beta cell functioning. In vivo, our pivotal model for diabetes treatment exhibited an improved glycemic profile of type 2 diabetic rats, where insulin secreted from encapsulated cells was more efficiently used. Conclusions: We were able to successfully introduce a novel valuable function in an old ally in biomedical applications, the alginate. The proposed alginate-RGD model stands out as a promising approach to improve beta cells survival and function, increasing the success of this therapeutic strategy, which might greatly improve the quality of life of an increasing number of diabetic patients worldwide.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by FCT/MEC through National Funds and co-financed by FEDER through the PT2020 Partnership Agreement under the 4293 Unit I&D, FCT Strategic Project PEst-C/SAU/UI3282/2011-2013 and UID/NEU/04539/2013, FCT in the framework of project UID/BIM/04293/2013, FCT in the framework of project IF/00939/2013/CP1179/CT0001, FCT for Joana Crisóstomo (grant number SFRH/BD/72964/2010), FCT for Sílvia J Bidarra (grant number SFRH/BPD/80571/2011), and FCT and POPH/ESF (EC) for Cristina C Barrias research position FCT Investigator (IF2013)

The Portfolio as an Evaluation Tool: an Analysis of its Use in an Undergraduate Nursing Program

This qualitative study was carried out between April and August 2007. It analyzed the use of portfolios in the academic community. A total of nine full-time professors and 119 students enrolled in their third semester were interviewed through a semi-structured interview. Content analysis was used to analyze data. Learning evaluations are seen as a verification of knowledge and efficacy of pedagogical method, and also as an incentive to study. Evaluations are procedural, that is, evaluation is continuous, or one-time, e.g. semester end tests. The portfolio is defined as a gradual and continuous evaluation tool. The faculty members and students need to accept the use of portfolios and evaluate the possibilities of this resource. This study is a first attempt to appraise the evaluation process of an undergraduate program, and the use of portfolios and other strategies needs to be consolidated in order to improve the educational process in undergraduate nursing programs.Se trata de un estudio cualitativo, realizado en el período de abril a agosto de 2007. El objetivo fue analizar la utilización del portafolio por la comunidad académica. Se entrevistó a través de un guión a nueve docentes efectivos y 119 discentes matriculados a partir del tercer período. En el análisis de datos se utilizó el análisis de contenido. La evaluación del aprendizaje es considerada como verificación del conocimiento, como eficacia del método pedagógico e incentivo al estudio. Con relación al tipo de evaluación son procesuales y puntuales. El portafolio es definido como un instrumento de evaluación gradual y continuo. Es necesario que el cuerpo docente y discente acepte experimentar la utilización del portafolio y así evaluar las posibilidades de este recurso. Representa una primera aproximación al proceso de evaluación en la graduación y de esa forma el portafolio y otras estrategias necesitan ser consolidadas de forma a mejorar el proceso de formación en la graduación de enfermería.Este é um estudo qualitativo, realizado no período de abril a agosto de 2007. O objetivo foi analisar a utilização do portfólio pela comunidade acadêmica. Entrevistaram-se, através de um roteiro, nove docentes efetivos e 119 discentes matriculados a partir do terceiro período. Na análise de dados utilizou-se da análise de conteúdo. A avaliação da aprendizagem é considerada como verificação do conhecimento, como eficácia do método pedagógico e incentivo ao estudo. Com relação aos tipos de avaliação são eles processuais e pontuais. O portfólio é definido como instrumento de avaliação gradual e contínuo. É necessário que o corpo docente e discente aceite experimentar a utilização do portfólio e assim avaliar as possibilidades desse recurso. Representa a primeira aproximação ao processo de avaliação na graduação e, dessa forma, o portfólio e outras estratégias precisam ser consolidadas de forma a melhorar o processo de formação na graduação de enfermagem

Inhibition of nitric oxide-stimulated vasorelaxation by carbon monoxide-releasing molecules.

Carbon monoxide (CO) is a weak soluble guanylyl cyclase stimulator, leading to transient increases in cGMP and vasodilation. The aim of the present work was to measure the effect of CO-releasing molecules (CORMs) on the cGMP/nitric oxide (NO) pathway and to evaluate how selected CORMs affect NO-induced vasorelaxation. METHODS AND RESULTS: Incubation of smooth muscle cells with some but not all of the CORMs caused a minor increase in cGMP levels. Concentration-response curves were bell-shaped, with higher CORMs concentrations producing lower increases in cGMP levels. Although exposure of cells to CORM-2 enhanced cGMP formation, we observed that the compound inhibited NO-stimulated cGMP accumulation in cells and NO-stimulated soluble guanylyl cyclase activity that could be reversed by superoxide anion scavengers. Reactive oxygen species generation from CORMs was confirmed using luminol-induced chemiluminescence and electron spin resonance. Furthermore, we observed that NO is scavenged by CORM-2. When used alone CORM-2 relaxed vessels through a cGMP-mediated pathway but attenuated NO donor-stimulated vasorelaxation. CONCLUSION: We conclude that the CORMs examined have context-dependent effects on vessel tone, as they can directly dilate blood vessels, but also block NO-induced vasorelaxation

Prevalência e fatores associados aos comportamentos sedentários em adolescentes

OBJETIVO Analisar a prevalência e fatores associados aos comportamentos sedentários em adolescentes. MÉTODOS Estudo transversal com adolescentes de 10 a 17 anos de idade, de ambos os sexos, pertencentes a uma coorte de nascimentos entre 1994-1999 na cidade de Cuiabá, Mato Grosso, Brasil. Para o levantamento dos dados, foi utilizado um questionário contendo informações sociodemográficas, econômicas e de estilo de vida e aferição de dados antropométricos. Determinou-se como comportamento sedentário o uso de televisão e/ou computador/vídeo games por um tempo igual ou superior a 4 horas/dia. Avaliou-se a associação de comportamentos sedentários com o índice de massa corporal, tanto na infância quanto na adolescência, e com variáveis sociodemográficas e comportamentais por meio de regressão logística hierarquizada. RESULTADOS A prevalência global de comportamentos sedentários foi de 58,1%. Dos 1.716 adolescentes estudados, 50,7% (n = 870) eram do sexo masculino. Na análise multivariada, após ajuste para fatores de confusão, as variáveis que permaneceram associadas com os comportamentos sedentários foram: idade (14 anos ou mais) (OR = 3,51; IC95% 2,19;5,60); classe econômica elevada (OR = 3,83; IC95% 2,10;7,01); maior nível de escolaridade da mãe (OR = 1,81; IC95% 1,09;3,01); residir no interior (OR = 0,49; IC95% 0,30;0,81); atividade física insuficiente (OR = 1,25; IC95% 1,02;1,53); experimentação de bebidas alcoólicas (OR = 1,34; IC95% 1,08;1,66) e excesso de peso na adolescência (OR = 1,33; IC95% 1,06;1,68). CONCLUSÕES A elevada proporção de adolescentes em atividades sedentárias e a não associação dessas atividades na adolescência com o excesso de peso na infância indicam a necessidade de intervenções para redução de vários comportamentos de risco. O incentivo à prática de atividade física como forma de reduzir os comportamentos sedentários e consequentemente o excesso de peso entre os jovens torna-se fundamental

Frequency of LCT -13910C>T single nucleotide polymorphism associated with adult-type hypolactasia/lactase persistence among Brazilians of different ethnic groups

<p>Abstract</p> <p>Background</p> <p>Adult-type hypolactasia, the physiological decline of lactase some time after weaning, was previously associated with the LCT -13910C>T polymorphism worldwide except in Africa. Lactase non-persistence is the most common phenotype in humans, except in northwestern Europe with its long history of pastoralism and milking. We had previously shown association of LCT -13910C>T polymorphism with adult-type hypolactasia in Brazilians; thus, we assessed its frequency among different Brazilian ethnic groups.</p> <p>Methods</p> <p>We investigated the ethnicity-related frequency of this polymorphism in 567 Brazilians [mean age, 42.1 ± 16.8 years; 157 (27.7%) men]; 399 (70.4%) White, 50 (8.8%) Black, 65 (11.5%) Brown, and 53 (9.3%) Japanese-Brazilian. DNA was extracted from leukocytes; LCT -13910C>T polymorphism was analyzed by PCR-restriction fragment length polymorphism.</p> <p>Results</p> <p>Prevalence of the CC genotype associated with hypolactasia was similar (57%) among White and Brown groups; however, prevalence was higher among Blacks (80%) and those of Japanese descent (100%). Only 2 (4%) Blacks had TT genotype, and 8 (16%) had the CT genotype. Assuming an association between CC genotype and hypolactasia, and CT and TT genotypes with lactase persistence, 356 (62.8%) individuals had hypolactasia and 211 (37.2%) had lactase persistence. The White and Brown groups had the same hypolactasia prevalence (~57%); nevertheless, was 80% among Black individuals and 100% among Japanese-Brazilians (<it>P </it>< 0.01).</p> <p>Conclusion</p> <p>The lactase persistence allele, LCT -13910T, was found in about 43% of both White and Brown and 20% of the Black Brazilians, but was absent among all Japanese Brazilians studied.</p

Occupation times of long-range exclusion and connections to KPZ class exponents

With respect to a class of long-range exclusion processes on \ZZ^d, with single particle transition rates of order $|\cdot|^{-(d+\alpha)}$, starting under Bernoulli invariant measure $\nu_\rho$ with density $\rho$, we consider the fluctuation behavior of occupation times at a vertex and more general additive functionals. Part of our motivation is to investigate the dependence on $\alpha$, $d$ and $\rho$ with respect to the variance of these functionals and associated scaling limits. In the case the rates are symmetric, among other results, we find the scaling limits exhaust a range of fractional Brownian motions with Hurst parameter $H\in [1/2,3/4]$. However, in the asymmetric case, we study the asymptotics of the variances, which when $d=1$ and $\rho=1/2$ points to a curious dichotomy between long-range strength parameters $03/2$. In the former case, the order of the occupation time variance is the same as under the process with symmetrized transition rates, which are calculated exactly. In the latter situation, we provide consistent lower and upper bounds and other motivations that this variance order is the same as under the asymmetric short-range model, which is connected to KPZ class scalings of the space-time bulk mass density fluctuations.The research of CB was supported in part by the French Ministry of Education through the grant ANR JCJC EDNHS. PG thanks FCT (Portugal) for support through the research project PTDC/MAT/109844/2009 and CNPq (Brazil) for support through the research project 480431/2013-2. PG thanks CMAT for support by "FEDER" through the "Programa Operacional Factores de Competitividade COMPETE" and by FCT through the project PEst-C/MAT/UI0013/2011. SS was supported in part by ARO grant W911NF-14-1-0179

An N-Acetyl Cysteine Ruthenium Tricarbonyl Conjugate Enables Simultaneous Release of CO and Ablation of Reactive Oxygen Species.

We have designed and synthesised a [Ru(CO)3 Cl2 (NAC)] pro-drug that features an N-acetyl cysteine (NAC) ligand. This NAC carbon monoxide releasing molecule (CORM) conjugate is able to simultaneously release biologically active CO and to ablate the concurrent formation of reactive oxygen species (ROS). Complexes of the general formulae [Ru(CO)3 (L)3 ](2+) , including [Ru(CO)3 Cl(glycinate)] (CORM-3), have been shown to produce ROS through a water-gas shift reaction, which contributes significantly, for example, to their antibacterial activity. In contrast, NAC-CORM conjugates do not produce ROS or possess antibacterial activity. In addition, we demonstrate the synergistic effect of CO and NAC both for the inhibition of nitric oxide (formation) and in the expression of tumour-necrosis factor (TNF)-α. This work highlights the advantages of combining a CO-releasing scaffold with the anti-oxidant and anti-inflammatory drug NAC in a unique pro-drug.We thank the EU (Marie Curie CIG to G.J.L.B.), FCT Portugal (FCT Investigator to G.J.L.B.; SFRH/BPD/95253/2013 to J.D.S.) and the EPSRC for funding. The NMR spectrometers are part of The National NMR Facility, supported by Fundação para a Ciência e a Tecnologia (RECI/BBB-BQB/0230/2012). G.J.L.B. is a Royal Society University Research Fellow.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/chem.20150247

Anti-malarial activity of indole alkaloids isolated from Aspidosperma olivaceum

Background: Several species of Aspidosperma (Apocynaceae) are used as treatments for human diseases in the tropics. Aspidosperma olivaceum, which is used to treat fevers in some regions of Brazil, contains the monoterpenoid indole alkaloids (MIAs) aspidoscarpine, uleine, apparicine, and N-methyl-tetrahydrolivacine. Using bio-guided fractionation and cytotoxicity testing in a human hepatoma cell line, several plant fractions and compounds purified from the bark and leaves of the plant were characterized for specific therapeutic activity (and selectivity index, SI) in vitro against the blood forms of Plasmodium falciparum. Methods: The activity of A. olivaceum extracts, fractions, and isolated compounds was evaluated against chloroquine (CQ)-resistant P. falciparum blood parasites by in vitro testing with radiolabelled [3H]-hypoxanthine and a monoclonal anti-histidine-rich protein (HRPII) antibody. The cytotoxicity of these fractions and compounds was evaluated in a human hepatoma cell line using a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, and the SI was calculated as the ratio between the toxicity and activity. Two leaf fractions were tested in mice with Plasmodium berghei. Results: All six fractions from the bark and leaf extracts were active in vitro at low doses (IC50 < 5.0 μg/mL) using the anti-HRPII test, and only two (the neutral and basic bark fractions) were toxic to a human cell line (HepG2). The most promising fractions were the crude leaf extract and its basic residue, which had SIs above 50. Among the four pure compounds evaluated, aspidoscarpine in the bark and leaf extracts showed the highest SI at 56; this compound, therefore, represents a possible anti-malarial drug that requires further study. The acidic leaf fraction administered by gavage to mice with blood-induced malaria was also active. Conclusion: Using a bio-monitoring approach, it was possible to attribute the anti-P. falciparum activity of A. olivaceum to aspidoscarpine and, to a lesser extent, N-methyl-tetrahydrolivacine; other isolated MIA molecules were active but had lower SIs due to their higher toxicities. These results stood in contrast to previous work in which the anti-malarial activity of other Aspidosperma species was attributed to uleine