Electrospun nanofibrous meshes cultured with Wharton’s Jelly Stem Cell: an alternative for cartilage regeneration, without the need of growth factors

Many efforts are being directed worldwide to the treatment of OA-focal lesions. The majority of those efforts comprise either the refinement of surgical techniques or combinations of biomaterials with various autologous cells. Herein, we tested electrospun polycaprolactone (PCL) nanofibrous meshes for cartilage tissue engineering. For that, articular chondrocytes (hACs) isolated from human osteoarthritic joints and Whartonâ s Jelly Stem Cells (hWJSCs) are cultured on electrospun nanofiber meshes, without adding external growth factors. We observed higher glycosaminoglycans production and higher overexpression of cartilage-related genes from hWJSCs cultured with basal medium, when compared to hACs isolated from osteoarthritic joints. Moreover, the presence of sulfated proteoglycans and collagen type II is observed on both types of cell cultures. We believe that this effect is due to either the electrospun nanofibers topography or the intrinsic chondrogenic differentiation potential of hWJSCs. Therefore, we propose the electrospun nanofibrous scaffolds in combination with hWJSCs as a viable alternative to the commercial membranes used in autologous chondrogenic regeneration approaches.The authors thank the Portuguese Foundation for Science and Technology for the Post-Doc grant of Marta Alves da Silva (SFRH/BPD/73322/2010, financed by POPH QREN Tipologia 4.1 – Advanced Formation, co-financed by Fundo Social Europeu and MEC national funds). This work was supported by the project SPARTAN (PTDC/CTM-BIO/4388/2014) FCT/MEC with PIDDAC funds. It was also partly supported by the POLARIS (FP7-REGPOT-2012-2013-1) and the Project “New methodologies for the isolation and control of stem cells differentiation using advanced culturing conditions and/or nanomaterials” (RL2 SCN NORTE-01-0124-FEDER-000018), co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

The worldwide marine radiocarbon reservoir effect: definitions, mechanisms, and prospects

When a carbon reservoir has a lower radiocarbon content than the atmosphere, this is referred to as a reservoir effect. This is expressed as an offset between the radiocarbon ages of samples from the two reservoirs at a single point in time. The marine reservoir effect (MRE) has been a major concern in the radiocarbon community, as it introduces an additional source of error that is often difficult to accurately quantify. For this reason, researchers are often reluctant to date marine material where they have another option. The influence of this phenomenon makes the study of the MRE important for a broad range of applications. The advent of Accelerator Mass Spectrometry (AMS) has reduced sample size requirements and increased measurement precision, in turn increasing the number of studies seeking to measure marine samples. These studies rely on overcoming the influence of the MRE on marine radiocarbon dates through the worldwide quantification of the local parameter ΔR, that is, the local variation from the global average MRE. Furthermore, the strong dependence on ocean dynamics makes the MRE a useful indicator for changes in oceanic circulation, carbon exchange between reservoirs, and the fate of atmospheric CO2, all of which impact Earth's climate. This article explores data from the Marine Reservoir Database and reviews the place of natural radiocarbon in oceanic records, focusing on key questions (e.g., changes in ocean dynamics) that have been answered by MRE studies and on their application to different subjects

Ionized outflows in SDSS type 2 quasars at z~0.3-0.6

We have analyzed the spatially integrated kinematic properties of the ionized gas within the inner r<few kpc in 13 optically selected SDSS type 2 quasars at z~0.3-0.6, using the [OIII]4959,5007 lines. The line profiles show a significant asymmetry in 11 objects. There is a clear preference for blue asymmetries, which are found in 9/13 quasars at 10% intensity level. In coherence with studies on other types of active and non active galaxies, we propose that the asymmetries are produced by outflows where differential dust extinction is at work. This scenario is favoured by other results we find: in addition to quiescent ambient gas, whose kinematic properties are consistent with gravitational motions, we have discovered highly perturbed gas in all objects. This gas emits very broad lines (R=FWHM[OIII]/FWHM(stars)>~2). While the quiescent gas shows small or null velocity shifts relative to the systemic velocity, the highly perturbed gas trends to show larger shifts which, moreover, are blueshifts in general. Within a given object, the most perturbed gas trends to have the largest blueshift as well. All together support that the perturbed gas, which is responsible for the blue asymmetries of the line profiles, is outflowing. Although some bias affects the sample, we argue that ionized gas outflows are a common phenomenon in optically selected type 2 quasars at 0.3< z < 0.6.Comment: Accepted for publication in MNRAS. 12 pages, 18 figure

Agronomic Management of Indigenous Mycorrhizas

Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production

Elemental biochemical analysis of the polysaccharides in the extracellular matrix of the yeast Saccharomyces cerevisiae

In yeast multicellular aggregates, such as biofilms and colonies, cells are supported by a yeast extracellular matrix (yECM) of glycosidic nature, the composition of which is mostly unknown. Saccharomyces cerevisiae ECM was produced, extracted and partitioned. An analytical-grade pure glycoside fraction was obtained, fractionated by anionic exchange liquid chromatography and analyzed by gas chromatography–mass spectrometry and polyacrylamide gel electrophoresis. Two different molecular weight polysaccharides were found, composed of glucose, mannose and small relative amounts of galactose. One of the polysaccharides had a low molecular weight, compatible with the association with glycoproteins abundantly occurring in yECM. In addition, these polysaccharide species were separated by diaminopropane agarose gel electrophoresis and induced metachromatic shift, suggesting chemical substitution, which was corroborated by anticoagulation activity. This was shown to be associated with the double deletion of the yeast homologues of the mammalian Hedgehog modulators Hhatl and Hhat, respectively yeast Gup1 and Gup2. These results pioneer the study of the molecular biology of the ECM supporting S. cerevisiae multicellular aggregates such as biofilms.The polysaccharide analysis was performed at the Laboratory of Glycoconjugates Biochemistry and Cellular Biology, UFRJ, Brazil. Fábio Faria-Oliveira was supported by a PhD scholarship (SFRH/BD/45368/2008) from FCT (Fundação para a Ciência e a Tecnologia). This work was funded by Marie Curie Initial Training Network GLYCOPHARM (PITN-GA-2012-317297), and FCT/MEC through Portuguese funds (PIDDAC)–PEst-OE/ BIA/UI4050/2014.info:eu-repo/semantics/publishedVersio

Progesterone reduces erectile dysfunction in sleep-deprived spontaneously hypertensive rats

BACKGROUND: Paradoxical sleep deprivation (PSD) associated with cocaine has been shown to enhance genital reflexes (penile erection-PE and ejaculation-EJ) in Wistar rats. Since hypertension predisposes males to erectile dysfunction, the aim of the present study was to investigate the effects of PSD on genital reflexes in the spontaneously hypertensive rat (SHR) compared to the Wistar strain. We also extended our study to examine how PSD affect steroid hormone concentrations involved in genital events in both experimental models. METHODS: The first experiment investigated the effects of PSD on genital reflexes of Wistar and SHR rats challenged by saline and cocaine (n = 10/group). To further examine the impact of the PSD on concentrations of sexual hormones, we performed a hormonal analysis of testosterone and progesterone in the Wistar and in SHR strains. Since after PSD progesterone concentrations decreased in the SHR compared to the Wistar PSD group we extended our study by investigating whether progesterone (25 mg/kg or 50 mg/kg) or testosterone (0.5 mg/kg or 1.0 mg/kg) administration during PSD would have a facilitator effect on the occurrence of genital reflexes in this hypertensive strain. RESULTS: A 4-day period of PSD induced PE in 50% of the Wistar rats against 10% for the SHR. These genital reflexes was potentiated by cocaine in Wistar rats whereas this scenario did not promote significant enhancement in PE and EJ in hypertensive rats, and the percentage of SHR displaying genital reflexes still figured significantly lower than that of the Wistar strain. As for hormone concentrations, both sleep-deprived Wistar and SHR showed lower testosterone concentrations than their respective controls. Sleep deprivation promoted an increase in concentrations of progesterone in Wistar rats, whereas no significant alterations were found after PSD in the SHR strain, which did not present enhancement in erectile responses. In order to explore the role of progesterone in the occurrence of genital reflexes, SHR were treated daily during the sleep deprivation period with progesterone; after the administration of this hormone and challenge with cocaine, we observed a significant increase in erectile events compared with the vehicle PSD SHR+cocaine group. CONCLUSION: Our data showed that the low frequency of genital reflexes found in SHR sleep deprived rats may be attributed to the lower concentrations of progesterone in these rats, based on the observation that progesterone replacement increased genital reflexes in this strain

Impact of amendments on the physical properties of soil under tropical long-term no till conditions

Tropical regions have been considered the world's primary agricultural frontier; however, some physico-chemical deficiencies, such as low soil organic matter content, poor soil structure, high erodibility, soil acidity, and aluminum toxicity, have affected their productive capacity. Lime and gypsum are commonly used to improve soil chemical fertility, but no information exists about the long-term effects of these products on the physical attributes and C protection mechanisms of highly weathered Oxisols. A field trial was conducted in a sandy clay loam (kaolinitic, thermic Typic Haplorthox) under a no-tillage system for 12 years. The trial consisted of four treatments: a control with no soil amendment application, the application of 2.1 Mg ha-1 phosphogypsum, the application of 2.0 Mg ha-1 lime, and the application of lime + phosphogypsum (2.0 + 2.1 Mg ha-1, respectively). Since the experiment was established in 2002, the rates have been applied three times (2002, 2004, and 2010). Surface liming effectively increased water-stable aggregates > 2.0 mm at a depth of up to 0.2 m; however, the association with phosphogypsum was considered a good strategy to improve the macroaggregate stability in subsoil layers (0.20 to 0.40 m). Consequently, both soil amendments applied together increased the mean weight diameter (MWD) and geometric mean diameter (GMD) in all soil layers, with increases of up to 118 and 89%, respectively, according to the soil layer. The formation and stabilization of larger aggregates contributed to a higher accumulation of total organic carbon (TOC) on these structures. In addition to TOC, the MWD and aggregate stability index were positively correlated with Ca2+ and Mg2+ levels and base saturation. Consequently, the increase observed in the aggregate size class resulted in a better organization of soil particles, increasing the macroporosity and reducing the soil bulk density and penetration resistance. Therefore, adequate soil chemical management plays a fundamental role in improving the soil's physical attributes in tropical areas under conservative management and highly affected by compaction caused by intensive farming

Erosão hídrica pós-plantio em florestas de eucalipto na bacia do rio Paraná, no leste do Mato Grosso do Sul

Nas regiões tropicais, o desgaste provocado no solo por ação das águas da chuva, ou seja, a erosão hídrica é a mais importante forma de degradação do solo. Visto que os plantios florestais de eucalipto estão inseridos em ecossistemas sensíveis às perturbações antrópicas em razão de ocorrência de plantações em solos com baixos teores de argila, com baixa fertilidade natural e grande parte das plantações estabelecidas em antigas áreas agrícolas e de pastagens degradadas, surge a necessidade do entendimento dos processos que regem a erosão hídrica e suas relações com as perdas de solo e água nos sistemas florestais. Objetivaram-se com este trabalho calcular os valores de erosividade da chuva (fator R - EI30), estimar a tolerância de perda de solo (T) para as classes representativas nas áreas de estudo, avaliar as perdas de solo e água por erosão hídrica e verificar a influência, por meio de análise de componentes principais (ACP), de atributos físicos e matéria orgânica do solo sobre a erosão hídrica em florestas de eucalipto no estádio de pós-plantio. Os tratamentos constituíram de diferentes sistemas de manejo dos resíduos e da disposição de plantio (nível e desnível), em dois biomas distintos, Cerrado e Floresta, e solo descoberto. Os solos foram classificados como Latossolo Vermelho distrófico típico textura média-alta fase floresta (LVd1) e Latossolo Vermelho distrófico típico textura média-baixa fase cerrado (LVd2). O estudo foi realizado em áreas experimentais de plantio de eucalipto localizadas no município de Três Lagoas, na bacia do Rio Paraná, no leste do Mato Grosso do Sul. O índice de erosividade anual obtido foi de 6.792,7 MJ mm ha-1 h-1 ano-1. Os valores de T variaram de 9,0 a 11,0 Mg ha-1 ano-1, para o LVd2 e LVd1, respectivamente. As perdas de solo apresentaram valores em torno de 0 a 0,505 Mg ha-1 no LVd1 e de 0 a 0,853 Mg ha-1, no LVd2. A ACP evidenciou-se eficiente na discriminação dos sistemas de manejo em razão da interação entre os atributos físicos e matéria orgânica do solo e suas relações com a erosão hídrica, possibilitando visualizar de forma clara a influência do manejo sobre esses atributos e a relação de ambos com as perdas de solo e água

Selective phosphodiesterase inhibitors: a promising target for cognition enhancement

# The Author(s) 2008. This article is published with open access at Springerlink.com Rationale One of the major complaints most people face during aging is an impairment in cognitive functioning. This has a negative impact on the quality of daily life and is even more prominent in patients suffering from neurodegenerative and psychiatric disorders including Alzheimer’s disease, schizophrenia, and depression. So far, the majority of cognition enhancers are generally targeting one particular neurotransmitter system. However, recently phosphodiesterases (PDEs) have gained increased attention as a potential new target for cognition enhancement. Inhibition of PDEs increases the intracellular availability of the second messengers cGMP and/or cAMP. Objective The aim of this review was to provide an overvie