925 research outputs found
The four hexamerin genes in the honey bee: structure, molecular evolution and function deduced from expression patterns in queens, workers and drones
Background: Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. Results: The hexamerin genes of the honey bee (hex 70a, hex 70b, hex 70c and hex 110) diverge considerably in structure, so that the overall amino acid identity shared among their deduced protein subunits varies from 30 to 42%. Bioinformatics search for motifs in the respective upstream control regions (UCRs) revealed six overrepresented motifs including a potential binding site for Ultraspiracle (Usp), a target of juvenile hormone (JH). The expression of these genes was induced by topical application of JH on worker larvae. The four genes are highly transcribed by the larval fat body, although with significant differences in transcript levels, but only hex 110 and hex 70a are re-induced in the adult fat body in a caste-and sex-specific fashion, workers showing the highest expression. Transcripts for hex 110, hex 70a and hex70b were detected in developing ovaries and testes, and hex 110 was highly transcribed in the ovaries of egg-laying queens. A phylogenetic analysis revealed that HEX 110 is located at the most basal position among the holometabola hexamerins, and like HEX 70a and HEX 70c, it shares potential orthology relationship with hexamerins from other hymenopteran species. Conclusions: Striking differences were found in the structure and developmental expression of the four hexamerin genes in the honey bee. The presence of a potential binding site for Usp in the respective 5' UCRs, and the results of experiments on JH level manipulation in vivo support the hypothesis of regulation by JH. Transcript levels and patterns in the fat body and gonads suggest that, in addition to their primary role in supplying amino acids for metamorphosis, hexamerins serve as storage proteins for gonad development, egg production, and to support foraging activity. A phylogenetic analysis including the four deduced hexamerins and related proteins revealed a complex pattern of evolution, with independent radiation in insect orders.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[05/03926-5; 08/00541-3
Chondroitin sulfate immobilization at the surface of electrospun nanofiber meshes for cartilage regeneration
Aiming at improving the biocompatibility of biomaterial scaffolds, surface
modification presents a way to preserve their mechanical properties and to
improve the surface bioactivity. In this work, chondroitin sulfate (CS) was
immobilized at the surface of electrospun poly(caprolactone) nanofiber meshes
(PCL NFMs). The immobilization was performed with 1-ethyl-3-(3-dimethylaminopropyl)
carbodiimide (EDC)/N-hydroxysuccinimide (NHS). Contact Angle,
SEM, Optical Profilometry, FTIR, X-ray photoelectron spectroscopy techniques
confirmed the CS-immobilization in PCL NFMs. Furthermore, CS-immobilized
PCL NFMs showed lower roughness and higher hydrophilicity than the samples
without CS. Human articular chondrocytes (HACs) were cultured on electrospun
PCL NFMs with or without CS immobilization. It was observed that HACs
proliferated through the entire time course of the experiment in both types of
scaffolds. SEM observations revealed that HACs maintained their typical
morphology and produced extracellular matrix. Glycosaminoglycans
quantification showed increased values over time. Quantitative-PCR of
cartilage-related genes revealed over-expression of Aggrecan, Collagen type II,
COMP and Sox9 on both types of NFMs tested, with higher values for PCL. In
conclusion, CS immobilization in PCL NFM was achieved successfully and
provides a valid platform enabling further surface functionalization methods in
scaffolds to be developed for cartilage tissue engineering
Association between gait speed and social participation in people with multiple sclerosis: A systematic review
Objetivo: Compreender a associação entre a velocidade da marcha e a participação social em pessoas com esclerose múltipla (EM). Metodologia: A presente revisão sistemática adotou a metodologia PRISMA. A pesquisa bibliográfica incluiu estudos em português/inglês, publicados até dezembro de 2019, sobre pessoas diagnosticadas com EM e se disponÃveis nas bases de dados PubMed e Scopus. Estudos elegÃveis abordaram a velocidade da marcha e a participação social em pessoas com EM. A seleção dos estudos foi realizada por dois investigadores independentes. Após a seleção dos estudos por tÃtulo e resumo, foi realizada a análise do texto integral dos estudos por outros dois investigadores, assim como a sua análise de qualidade metodológica utilizando a Critical Appraisal Checklist do Joanna Briggs Institute (JBI). Resultados: Dos 3726 estudos identificados, sete cumpriram os critérios de elegibilidade definidos. Os estudos de Kierkegaard et al. (2012) e de Cattaneo et al. (2017) destacam-se pela sua elevada qualidade metodológica. Deteta-se variabilidade e pouca especificidade na avaliação da participação social. Valores de velocidade de marcha elevados estão associados a uma participação social ativa, com uma tendência para valores mÃnimos de velocidade de 0,95m/s serem indicativos de uma participação social mÃnima. Conclusão: A presente revisão sistemática permite concluir que existe uma tendência para uma associação positiva entre a velocidade da marcha e a participação social em pessoas com EM. Futuros estudos na área deverão procurar melhorar a seleção de instrumentos de avaliação para a participação social na pessoa com EM.info:eu-repo/semantics/publishedVersio
Antifungal and anti-biofilm activity of designed derivatives from kyotorphin
© 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved.Kyotorphin (KTP, l-tyrosyl-l-arginine) is an endogenous analgesic neuropeptide first isolated from bovine brain in 1979. Previous studies have shown that kyotorphins possess anti-inflammatory and antimicrobial activity. Six kyotorphins—KTP-NH2, KTP–NH2–DL, ibuprofen-conjugated KTP (IbKTP), IbKTP-NH2, N-methyl-D-Tyr-L-Arg, and N-methyl-L-Tyr-D-Arg—were designed and synthesized to improve lipophilicity and resistance to enzymatic degradation. This study assessed the antimicrobial and antibiofilm activity of these peptides. The antifungal activity of kyotorphins was determined in representative strains of Candida species, including Candida albicans ATCC 10231, Candida krusei ATCC 6258, and six clinical isolates—Candida dubliniensis 19-S, Candida glabrata 217-S, Candida lusitaniae 14-S, Candida novergensis 51-S, Candida parapsilosis 63, and Candida tropicalis 140-S—obtained from the oral cavity of HIV-positive patients. The peptides were synthesized by standard solution or solid-phase synthesis, purified by RP-HPLC (purity >95 %), and characterized by nuclear magnetic resonance. The results of the broth microdilution assay and scanning electron microscopy showed that IbKTP-NH2 presented significant antifungal activity against Candida strains and antibiofilm activity against the clinical isolates. The absence of toxic activity and survival after infection was assessed after injecting the peptide in larvae of Galleria mellonella as experimental infection model. Furthermore, IbKTP-NH2 had strong antimicrobial activity against multidrug-resistant bacteria and fungi and was not toxic to G. mellonella larvae up to a concentration of 500 mM. These results suggest that IbKTP-NH2, in addition to its known effect on cell membranes, can elicit a cellular immune response and, therefore, is promising for biomedical application.This research was supported by FAPESP (Grant No. 2017/00032-0). This article is also part of the Fungal Adaptation to Hostile Challenges special issue for the third International Symposium on Fungal Stress (ISFUS), which is supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (Grant No. 2018/20571-6) and the Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES) (Grant No. 88881.289327/2018-01).info:eu-repo/semantics/publishedVersio
Preparation of robust polyamide microcapsules by interfacial polycondensation of p-phenylenediamine and sebacoyl chloride and plasticization with oleic acid
Microcapsules produced by interfacial polycondensation of p-phenylenediamine (PPD) and sebacoyl chloride (SC) were studied. The products were characterized in terms of morphology, mean diameter and effectiveness of dodecane encapsulation. The use of Tween 20 as dispersion stabilizer, in comparison with polyvinyl alcohol (PVA), reduced considerably the mean diameter of the microcapsules and originated smoother wall surfaces. When compared to ethylenediamine (EDA), microcapsules produced with PPD monomer were more rigid and brittle, prone to fracture during processing and ineffective retention of the core liquid. The use of diethylenetriamine (DETA) cross-linker in combination with PPD did not decrease capsule fragility. On the other hand, addition of a small fraction of oleic acid to the organic phase remarkably improved wall toughness and lead to successful encapsulation of the core-oil. Oleic acid is believed to act as a plasticizer. Its incorporation in the polymeric wall was demonstrated by FTIR and (1)H-NMR.This work was funded by FEDER funds through the Operational
Programme for Competitiveness Factors (COMPETE), ON.2 – O Novo
Norte – North Portugal Regional Operational Programme and National
Funds through Foundation for Science and Technology (FCT) under the projects: PEst-C/EQB/UI0511, NORTE-07-0124-FEDER-000026 – RL1_ Energy and PTDC/CTM-NAN/119979/2010. The Bruker Avance III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment, REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). Joana R. Góis acknowledges FCT-MCTES for her PhD scholarship (SFRH/BD/69635/2010)
Investigation of hypovitaminosis D in patients infected with SARS-CoV-2 and its relationship with clinical worsening: a cross-sectional observational retrospective clinical study
Numerous studies have demonstrated the profile of infection and symptoms related to COVID-19 that occur with pulmonary manifestations (such as Acute Respiratory Syndrome), digestive symptoms, anosmia, and ageusia. Many comorbidities have been associated with deaths and severe cases of the disease, such as diabetes, hypertension, obesity, and heart disease. However, many questions remain unanswered, especially the association of disease severity with hypovitaminosis D. Vitamin D deficiency is widely found in patients in Intensive Care Units, and recent studies have shown that it has been suggested that patients with severe manifestations of COVID-19 have hypovitaminosis D. Therefore, the present study aims to associate the presence of hypovitaminosis D in patients with the acute respiratory syndrome, positive for SARS-COV-2, admitted to the José Alencar Regional Hospital in Uberaba/Brazil and the evolution of the disease (days of hospitalization, hospitalization in the ICU, discharge and death) through the analysis of vitamin D (25(OH)D) hospitalized patients clinical records. The incidence of hypovitaminosis D among the patients was also assessed. The results may contribute to the understanding of the disease, as well as the need for vitamin supplementation
Agronomic biofortification of cowpea with selenium: effects of selenate and selenite applications on selenium and phytate concentrations in seeds
BACKGROUNDSelenium (Se) is a nutrient for animals and humans, and is considered beneficial to higher plants. Selenium concentrations are low in most soils, which can result in a lack of Se in plants, and consequently in human diets. Phytic acid (PA) is the main storage form of phosphorus in seeds, and it is able to form insoluble complexes with essential minerals in the monogastric gut. This study aimed to establish optimal levels of Se application to cowpea, with the aim of increasing Se concentrations. The efficiency of agronomic biofortification was evaluated by the application of seven levels of Se (0, 2.5, 5, 10, 20, 40, and 60 g ha−1) from two sources (selenate and selenite) to the soil under field conditions in 2016 and 2017.RESULTSApplication of Se as selenate led to greater plant Se concentrations than application as selenite in both leaves and grains. Assuming human cowpea consumption of 54.2 g day−1, Se application of 20 g ha−1 in 2016 or 10 g ha−1 in 2017 as selenate would have provided a suitable daily intake of Se (between 20 and 55 μg day−1) for humans. Phytic acid showed no direct response to Se application.CONCLUSIONSelenate provides greater phytoavailability than selenite. The application of 10 g Se ha−1 of selenate to cowpea plants could provide sufficient seed Se to increase daily human intake by 13–14 μg d−1. © 2019 Society of Chemical Industr
Antigenicity and Immunogenicity of Plasmodium vivax Merozoite Surface Protein-3
A recent clinical trial in African children demonstrated the potential utility of merozoite surface protein (MSP)-3 as a vaccine against Plasmodium falciparum malaria. the present study evaluated the use of Plasmodium vivax MSP-3 (PvMSP-3) as a target antigen in vaccine formulations against malaria caused by P. vivax. Recombinant proteins representing MSP-3 alpha and MSP-3 beta of P. vivax were expressed as soluble histidine-tagged bacterial fusions. Antigenicity during natural infection was evaluated by detecting specific antibodies using sera from individuals living in endemic areas of Brazil. A large proportion of infected individuals presented IgG antibodies to PvMSP-3 alpha (68.2%) and at least 1 recombinant protein representing PvMSP-3 beta (79.1%). in spite of the large responder frequency, reactivity to both antigens was significantly lower than was observed for the immunodominant epitope present on the 19-kDa C-terminal region of PvMSP-1. Immunogenicity of the recombinant proteins was studied in mice in the absence or presence of different adjuvant formulations. PvMSP-3 beta, but not PvMSP-3 alpha, induced a TLR4-independent humoral immune response in the absence of any adjuvant formulation. the immunogenicity of the recombinant antigens were also tested in formulations containing different adjuvants (Alum, Salmonella enterica flagellin, CpG, Quil A, TiterMax (R) and incomplete Freunds adjuvant) and combinations of two adjuvants (Alum plus flagellin, and CpG plus flagellin). Recombinant PvMSP-3 alpha and PvMSP-3 beta elicited higher antibody titers capable of recognizing P. vivax-infected erythrocytes harvested from malaria patients. Our results confirm that P. vivax MSP-3 antigens are immunogenic during natural infection, and the corresponding recombinant proteins may be useful in elucidating their vaccine potential.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)US National Institutes of Health, National Institute for Allergy and Infectious DiseasesSIgNHorizontal Programme on Infectious Diseases under the Agency for Science, Technology and Research (A*STAR, Singapore)Wellcome Trust of Great Britain, as part of the Oxford Tropical Medicine Research Programme of Wellcome Trust-Mahidol UniversityUniv São Paulo, Fac Ciencias Farmaceut, Dept Anal Clin & Toxicol, São Paulo, BrazilUniv Estadual Campinas, Dept Genet Evolucao & Bioagentes, Inst Biol, Campinas, SP, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Microbiol, BR-05508 São Paulo, BrazilNatl Univ Singapore, Yong Loo Lin Sch Med, Dept Microbiol, Singapore 117595, SingaporeAgcy Sci Technol & Res, Singapore Immunol Network, Biopolis, Singapore, SingaporeChurchill Hosp, Ctr Vaccinol & Trop Med, Oxford OX3 7LJ, EnglandMahidol Oxford Univ Trop Med Res Programme, Shoklo Malaria Res Unit, Mae Sot, ThailandEmory Univ, Emory Vaccine Ctr, Atlanta, GA 30322 USAEmory Univ, Yerkes Natl Primate Res Ctr, Atlanta, GA 30322 USAEmory Univ, Dept Med, Div Infect Dis, Atlanta, GA 30322 USACtr Dis Control & Prevent, Malaria Branch, Div Parasit Dis, Chamblee, GA USAUniversidade Federal de São Paulo, CTCMOL, Dept Microbiol Imunol & Parasitol, Escola Paulista Med, São Paulo, BrazilUniversidade Federal de São Paulo, CTCMOL, Dept Microbiol Imunol & Parasitol, Escola Paulista Med, São Paulo, BrazilFAPESP: 2010/09893-0US National Institutes of Health, National Institute for Allergy and Infectious Diseases: 1R01AI24710Web of Scienc
Hydrogels Based on Chitosan and Chitosan Derivatives for Biomedical Applications
Chitosan (CS) is a polymer obtained from chitin, being this, after the cellulose, the most abundant polysaccharide. The fact of (i) CS being obtained from renewable sources; (ii) CS to possess capability for doing interactions with different moieties being such capability dependent of pH; (iii) plenty of possibilities for chemical modification of CS; and (iv) tuning the final properties of CS derivatives makes this polymer very interesting in academic and technological points of view. In this way, hydrogels based on CS and on CS derivatives have been widely used for biomedical applications. Other important technological applications can be also cited, such as adsorbent of metals and dyes in wastewater from industrial effluents. In pharmaceutical field, hydrogels based on CS are often used as drugs’ and proteins’ carrier formulations due to the inherent characteristics such as the biocompatibility, nontoxicity, hydrophilicity, etc. This chapter is an attempt for updating and joining the plenty of available information regarding the preparation, characterization, and biomedical application of hydrogels based on chitosan and chitosan derivatives. More than 260 references are provided, being the majority of them published in the last 10 years
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