2,888 research outputs found

    Interploidy Hybridization In Sympatric Zones: The Formation Of Epidendrum Fulgens × E. Puniceoluteum Hybrids (epidendroideae, Orchidaceae).

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    Interspecific hybridization is a primary cause of extensive morphological and chromosomal variation and plays an important role in plant species diversification. However, the role of interploidal hybridization in the formation of hybrid swarms is less clear. Epidendrum encompasses wide variation in chromosome number and lacks strong premating barriers, making the genus a good model for clarifying the role of chromosomes in postzygotic barriers in interploidal hybrids. In this sense, hybrids from the interploidal sympatric zone between E. fulgens (2n = 2x = 24) and E. puniceoluteum (2n = 4x = 56) were analyzed using cytogenetic techniques to elucidate the formation and establishment of interploidal hybrids. Hybrids were not a uniform group: two chromosome numbers were observed, with the variation being a consequence of severe hybrid meiotic abnormalities and backcrossing with E. puniceoluteum. The hybrids were triploids (2n = 3x = 38 and 40) and despite the occurrence of enormous meiotic problems associated with triploidy, the hybrids were able to backcross, producing successful hybrid individuals with broad ecological distributions. In spite of the nonpolyploidization of the hybrid, its formation is a long-term evolutionary process rather than a product of a recent disturbance, and considering other sympatric zones in Epidendrum, these events could be recurrent.33824-3

    Temporal control of epigenetic centromere specification

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    All living organisms require accurate mechanisms to faithfully inherit their genetic material during cell division. The centromere is a unique locus on each chromosome that supports a multiprotein structure called the kinetochore. During mitosis, the kinetochore is responsible for connecting chromosomes to spindle microtubules, allowing faithful segregation of the duplicated genome. In most organisms, centromere position and function is not defined by the local DNA sequence context but rather by an epigenetic chromatin-based mechanism. Centromere protein A (CENP-A) is central to this process, as chromatin assembled from this histone H3 variant is essential for assembly of the centromere complex, as well as for its epigenetic maintenance. As a major determinant of centromere function, CENP-A assembly requires tight control, both in its specificity for the centromere and in timing of assembly. In the last few years, there have been several new insights into the molecular mechanism that allow this process to occur. We will review these here and discuss the general implications of the mechanism of cell cycle coupling of centromere inheritance.FCT fellowships: (SFRH/BPD/69115/2010, SFRH/BD/33219/2007); FCT grants: (BIA-BCM/100557/2008, BIA-PRO/100537/2008);Fundação Calouste Gulbenkian; European Commission FP7 programme; EMBO installation grant

    COVID‐19 vaccination acceptance: A case of interplay between political and health dimensions

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    Vaccines are essential for the eradication of diseases. Yet for many reasons, individuals do not embrace them completely. In the COVID- 19 pandemic and with the possibility of the Brazilian population’s immunization against the disease, both political and health- related dimensions might have had a role in individual COVID- 19 vaccination acceptance. In two studies (n = 974), we tested the hypothesis that participants’ vaccination acceptance is related to their past vote in the 2018 Brazilian presidential election (being or not being a Jair Bolsonaro voter) and their different levels of perceived vulnerability to disease (PVD). We further tested whether Bolsonaro’s opposition or ambiguous messages towards vaccination (vs. control) increased vaccination rejection among those who have (vs. have not) voted for him and who are low (vs. high) in PVD. Results show that Bolsonaro (vs. non- Bolsonaro) voters accepted less vaccination, with higher rejection rates when participants expressed low (vs. high) PVD. Also, when primed either with Bolsonaro’s opposed or ambiguous messages towards COVID- 19 vaccination, such participants accepted less vaccines (vs. participants primed with neutral information). These findings are the first to show that the COVID- 19 vaccine acceptance is related to their past vote and leadership influence but also different levels of perceived vulnerability to disease.info:eu-repo/semantics/publishedVersio

    RNA-seq – Revealing Biological Insights in Bacteria

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    New technologies are constantly being released and the improvements therein bring advances not only to transcriptome, the focus of this chapter, but also to diverse areas of biological research. Since the announcement and application of the RNA-seq approach, discoveries are being made in this field, but when we consider bacterial species, this progress proceeded a few years behind. However, with the application of RNA-seq derivative approaches, we can gain biological insights into the bacterial world and aspire to uncover the mysteries involving gene expression, organization and other functional genomic features

    Effect of metabolic syndrome and individual components on colon cancer characteristics and prognosis

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    Metabolic syndrome (MS) is recognized as a risk factor for colon cancer (CC). However, whether the cluster of metabolic changes that define MS also influence CC prognosis remains unclear. Thus, our aim was to investigate whether the presence of MS or any of the MS individual components could provide prognostic information on tumor phenotype and survival outcomes. Clinical and pathological data from patients with CC (n = 300) who underwent surgical resection at a single tertiary hospital were retrospectively collected to evaluate presence of MS components and diagnostic criteria, CC phenotype and disease outcomes. Patients were allocated into two groups according to the presence or absence of MS (n = 85 MS vs n = 83 non-MS). The overall prevalence of MS individual components was 82.7% for increased waist-circumference (WC), 61.3% for high blood pressure (BP), 48.8% for low HDL-cholesterol, 39.9% for high fasting glucose, and 33.9% for hypertriglyceridemia. Patients in the MS group presented smaller tumors (p = 0.006) with lower T-stage (p = 0.002). High BP (p = 0.029) and hypertriglyceridemia (p = 0.044) were associated with a smaller tumor size, while low-HDL (p = 0.008) was associated with lower T-stage. After propensity score matching using age, tumor size and staging as covariates high-BP (p = 0.020) and WC (p = 0.003) were found to influence disease-free survival, but not overall survival. In conclusion, despite MS being an established risk factor for CC, our data does not support the hypothesis that MS components have a negative impact on disease extension or prognosis. Nevertheless, a protective role of BP and lipid lowering drugs cannot be excluded.info:eu-repo/semantics/publishedVersio

    Stem cells labeled with superparamagnetic iron oxide nanoparticles in a preclinical model of cerebral ischemia: a systematic review with meta-analysis

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    Introduction: Although there is an increase in clinical trials assessing the efficacy of cell therapy in structural and functional regeneration after stroke, there are not enough data in the literature describing the best cell type to be used, the best route, and also the best nanoparticle to analyze these stem cells in vivo. This review analyzed published data on superparamagnetic iron oxide nanoparticle (SPION)-labeled stem cells used for ischemic stroke therapy.Method: We performed a systematic review and meta-analysis of data from experiments testing the efficacy of cellular treatment with SPION versus no treatment to improve behavioral or modified neural scale outcomes in animal models of stroke by the Cochrane Collaboration and indexed in EMBASE, PubMed, and Web of Science since 2000. To test the impact of study quality and design characteristics, we used random-effects meta-regression. in addition, trim and fill were used to assess publication bias.Results: the search retrieved 258 articles. After application of the inclusion criteria, 24 reports published between January 2000 and October 2014 were selected. These 24 articles were analyzed for nanoparticle characteristics, stem cell types, and efficacy in animal models.Conclusion: This study highlights the therapeutic role of stem cells in stroke and emphasizes nanotechnology as an important tool for monitoring stem cell migration to the affected neurological locus.Instituto Israelita de Ensino e Pesquisa Albert EinsteinCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPEGHosp Israelita Albert Einstein, BR-05651901 São Paulo, BrazilUniversidade Federal de São Paulo, BR-04021001 São Paulo, SP, BrazilSanta Casa Misericordia São Paulo, BR-01221020 São Paulo, SP, BrazilUniv São Paulo, Inst Matemat & Estat, BR-05508090 São Paulo, SP, BrazilUniv São Paulo, LIM44, BR-05403000 São Paulo, SP, BrazilUniversidade Federal de São Paulo, BR-04021001 São Paulo, SP, BrazilWeb of Scienc

    Pre-selection of fibroblasts subsets prompt prevascularization of tissue engineered skin analogues

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    The papillary and reticular dermis harbors phenotypically distinct fibroblasts, whose functions such as maintenance of skin's microvasculature are also distinct. Thus, we hypothesized that pre-selection of the subpopulations of fibroblasts would benefit the generation of skin tissue engineered (TE) constructs, promoting their prevascularization in vitro. We first isolated papillary and reticular fibroblasts using fluorescence-activated cell sorting and studied the effect of their secretome and extracellular matrix (ECM) on human dermal microvascular endothelial cell (hDMEC) organization. Subsequently, we developed a bilayered 3D polymeric structure with distinct layer-associated features to house the subpopulations of fibroblasts, to generate a skin analogue. Both papillary and reticular fibroblasts were able to stimulate capillary-like network formation in a Matrigel assay. However, the secretome of the two subpopulations was substantially different, being enriched in VEGF, IGF-1, and Angio-1 in the case of papillary fibroblasts and in HGF and FGF-2 for the reticular subset. In addition, the fibroblast subpopulations deposited varied levels of ECM proteins, more collagen I and laminin was produced by the reticular subset, but these differences did not impact hDMEC organization. Vessel-like structures with lumens were observed earlier in the 3D skin analogue prepared with the sorted fibroblasts, although ECM deposition was not affected by the cell's pre-selection. Moreover, a more differentiated epidermal layer was obtained in the skin analogue formed by the sorted fibroblasts, confirming that its whole structure was not affected. Overall, we provide evidence that pre-selection of papillary and reticular fibroblasts is relevant for promoting the in vitro prevascularization of skin TE constructs.The authors would like to acknowledge the financial support from the Consolidator Grant “ECM_INK” (ERC-2016- COG-726061), to the FSE/POCH (Fundo Social Europeu através do Programa Operacional do Capital Humano) under the scope of the PD/169/2013, NORTE-08-5369-FSE-000037 (H.R. M.)

    Obesity, energy balance and spermatogenesis

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    Obesity has grown to pandemic proportions. It affects an increasing number of children, adolescents and young adults exposed to the silent comorbidities of this disorder for a longer period. Infertility has arisen as one important comorbidity associated with the energy dysfunction promoted by obesity. Spermatogenesis is a highly regulated process that is determined by specific energetic requirements. The reproductive potential of males relies on hormonal-dependent and -independent stimuli that control sperm quality. There are conflicting data concerning the impact of male overweight and obesity on sperm quality, as well as on the possible paternal-induced epigenetic trait inheritance of obesity. In addition, it remains a matter of debate whether massive weight loss induced by lifestyle interventions, drugs or bariatric surgery may or may not benefit obese men seeking fatherhood. Herein, we propose to discuss how energy balance may modulate hormonal signalling and sperm quality in overweight and obese men. We also discuss some molecular mechanisms that mediate obesity-related dysfunction in male reproductive system and how paternal obesity may lead to trait inheritance. Finally, we will discuss how lifestyle modifications and sustained weight loss, particularly the loss achieved by bariatric surgery, may revert some of the deleterious effects of obesity in men and their offspring.info:eu-repo/semantics/publishedVersio

    Ultrasonography Reliability in the Detection of Inflammatory and Structural Abnormalities: An Exercise in Multiple Joints

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    Background Ultrasonography is an image technique that allows rheumatologists to visualize structural and inflammatory changes within a joint. The objective of this study was to assess the interobserver and intraobserver reliability of musculoskeletal ultrasound (US) in the detection of inflammatory and destructive joint changes in patients with polyarthritis. Methods A Delphi exercise was undertaken to standardize and adapt the EULAR-OMERACT elementary US definitions of inflammatory lesions (effusion, synovial hypertrophy, power Doppler, bone erosions, and synovitis) for each joint. Fifteen patients were analyzed, and video clips of 600 joints were collected. Each joint was scored for the presence of each elementary component, on 2 separate occasions, by 6 examiners. Interobserver and intraobserver agreement analysis was assessed through Fleiss κ coefficient (κ). Results Considering all patients and all joints, the interobserver values were highest for erosions and lowest for effusion (κ = 0.7314 and κ = 0.6044, respectively). When analyzing different regions, the highest interobserver agreement was for tibiotalar joint (κ = 0.8043) and the lowest for wrist (κ = 0.6767). Intraobserver reliability was excellent for each and all elementary components and anatomical region. Conclusions The present study showed either a good or excellent US interobserver and intraobserver reliability in elementary elements and anatomical region. This kind of US reliability exercises are important for standardization of exploration in everyday practice by reducing the variability associated with this imaging technique, and ensuring a greater degree of homogeneity and future comparability in the assessment of disease activity in polyarthritis patients.info:eu-repo/semantics/publishedVersio
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