Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Sci Rep ; 13(1): 14382, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658081

RESUMO

Novel male contraceptives will promote gender equality in sharing contraceptive responsibility. The sperm-associated protein epididymal protease inhibitor (EPPIN) is a promising target for non-hormonal male contraception. EPPIN interacts with the semen coagulum protein semenogelin-1 (SEMG1) on the sperm surface, leading to transient inhibition of sperm motility after ejaculation. Small organic molecules targeting EPPIN's SEMG1-binding are under development as male contraceptives. Here, we combined computational approaches to uncover key aspects underlying EPPIN binding to SEMG1 and small organic ligands. We generated a human EPPIN model showing a typical arrangement of the WFDC (Whey-acid four disulfide core)-type and Kunitz-type domains, connected by a hinge region. Determining the EPPIN model's intrinsic motion by molecular dynamics simulations and normal mode analysis revealed a conformation, presenting a binding pocket that accommodates SEMG1Glu229-Gln247, EP055, and EP012. EPPIN's residues Phe63 and Lys68 (WFDC domain), Asp71 (hinge region), and Asn113, Asn114, and Asn115 (Kunitz domain) were identified as hot spots for SEMG1, EP055, and EP012 binding. Moreover, hydrophobic and hydrophilic residues in the WFDC and Kunitz domains allow plasma membrane anchoring, orienting the EPPIN binding pocket to the solvent. Targeting EPPIN's essential residues for its biomolecular interactions may improve the rational design of EPPIN ligands as spermiostatic compounds.


Assuntos
Anticoncepcionais Masculinos , Humanos , Masculino , Anticoncepcionais Masculinos/farmacologia , Ligantes , Sêmen , Motilidade dos Espermatozoides , Anticoncepcionais
2.
Int J Equity Health ; 22(1): 100, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37226195

RESUMO

BACKGROUND: Violence is a worldwide public health challenge and has been linked to depression in many settings. Depression is higher in women and differential exposure to violence is a potential risk factor - especially in countries with high-levels of violence. This paper provides a comprehensive characterization of the association between violence victimization and depression in Brazil, focusing on sex/gender inequalities. METHODS: We used data from the 2019 wave of the National Health Survey (PNS) in Brazil to assess whether respondents had depression (using PHQ-9) and if they were victims of violence, differentiating by the type of violence, the frequency of victimization, and the primary aggressor. We used logit models to assess the association between victimization and the likelihood of having depression. We predicted probabilities of being depressed, considering the interaction between violence victimization and sex/gender, to analyze the differences between men and women. RESULTS: Rates of violence victimization and depression were higher among women than among men. The odds of being depressed were 3.8 (95%CI: 3.5-4.2) times higher among victims of violence than among non-victims, and 2.3 (95%CI: 2.1-2.6) times higher among women than among men, adjusting for socioeconomic factors. For any given income level, racial/ethnic or age group, victims of violence who were women had the highest predicted probabilities of being depressed - e.g., 29.4% (95%CI: 26.1-32.8) for lower-income women, 28.9% (95%CI: 24.4-33.2) for black women, and 30.4% (95%CI: 25.4-35.4) for younger women that suffered violence. Over one in three women that suffered multiple types of violence, experienced violence more frequently, or where the aggressor was an intimate partner or another family member were predicted to have depression. CONCLUSIONS: Being a victim of violence was strongly associated with higher risk of depression in Brazil, with women more likely to be both victims of violence and develop depression. Frequent, sexual, physical or psychological violence, and intimate partners or family member perpetrators were major risk factors for depression and should be a public health priority.


Assuntos
Vítimas de Crime , Depressão , Masculino , Feminino , Humanos , Brasil/epidemiologia , Depressão/epidemiologia , Depressão/etiologia , Equidade de Gênero , Violência , Inquéritos Epidemiológicos
3.
Cad Saude Publica ; 39(1): e00169622, 2023.
Artigo em Português | MEDLINE | ID: mdl-36856228

RESUMO

In Brazil, the Food and Nutrition Surveillance System (SISVAN) is the main tool in collecting and consolidating information on the nutritional status and the feeding habits of the population encompassed by primary health care services of the country. This study explores data from SISVAN to analyze the system's potential as a tool for monitoring the nutritional status of children and adolescents in the country. We seek to evaluate the evolution of the system's coverage rate in relation to the population regarding different age groups and geographic regions, how this coverage rate varies according to the characteristics of the Brazilian municipalities, and to what extent the results from SISVAN differ from representative sample surveys of the population. We present four main results. First, we documented that from 2008 to 2019, SISVAN significantly expanded its coverage; with a significant decrease, however, in 2020, reaching levels similar to those at the beginning of the series. Second, our results indicate that coverage is not homogeneous, being higher in the North and Northeast regions and among underage children. Third, there is a systematic association between the characteristics of the municipalities and the level of coverage of the system. Finally, SISVAN results differ from those presented by surveys representative of the general population. Jointly, the results of this study point to the need to refine the nutritional surveillance instruments on children and adolescents in Brazil.


No Brasil, o Sistema de Vigilância Alimentar e Nutricional (SISVAN) é a ferramenta central para coletar e consolidar informações sobre o estado nutricional e alimentação da população atendida pelos serviços de atenção básica no país. Este trabalho explora dados do SISVAN com o objetivo de analisar o potencial do sistema como ferramenta de monitoramento do estado nutricional de crianças e adolescentes no país. Procura-se avaliar a evolução da taxa de cobertura do sistema em relação à população para diferentes faixas etárias e regiões geográficas, como essa taxa de cobertura varia conforme as características dos municípios brasileiros e em que medida os resultados provenientes do SISVAN diferem de pesquisas amostrais representativas da população. Apresentamos quatro principais resultados. Primeiro, documentamos que, entre 2008 e 2019, o SISVAN expandiu significativamente a sua cobertura, mas houve uma queda expressiva em 2020 até níveis similares aos do início da série. Segundo, nossos resultados apontam que a cobertura não é homogênea, sendo maior nas regiões Norte e Nordeste e entre crianças de menor idade. Terceiro, existe uma associação sistemática entre características dos municípios e o nível de cobertura do sistema. Por último, os resultados do SISVAN divergem dos apresentados por pesquisas representativas da população geral. Em conjunto, os resultados deste estudo apontam para a necessidade de refinar os instrumentos de vigilância nutricional sobre crianças e adolescentes no Brasil.


En Brasil, el Sistema de Vigilancia Alimentaria y Nutricional (SISVAN) es una herramienta clave para recolectar y consolidar información sobre el estado nutricional y la dieta de la población atendida por los servicios de atención primaria en el país. Este trabajo analiza, a partir de los datos de SISVAN, el potencial del sistema como una herramienta de seguimiento del estado nutricional de niños y adolescentes del país. Se pretende evaluar la evolución de la tasa de cobertura del sistema con relación a la población según diferentes grupos de edad y regiones geográficas, cómo varía esta tasa de cobertura según las características de los municipios brasileños y en qué medida los resultados de SISVAN se diferencian de las encuestas por muestreo representativas de la población. Se presentan cuatro resultados principales. Primero, entre 2008 y 2019, SISVAN amplió significativamente su cobertura, pero en 2020 hubo un significativo descenso a niveles similares a los del inicio de la serie. Segundo, los resultados indican que la cobertura no es homogénea, y hay una mayor cobertura en las regiones Norte y Nordeste del país, entre los niños más pequeños. Tercero, existe una asociación sistemática entre las características de los municipios y el nivel de cobertura del sistema. Cuarto, los resultados de SISVAN se diferencian de los presentados en las encuestas representativas de la población general. Los resultados de este estudio apuntan que es necesario mejorar las herramientas de vigilancia nutricional de niños y adolescentes en Brasil.


Assuntos
Alimentos , Estado Nutricional , Humanos , Adolescente , Criança , Brasil/epidemiologia
4.
Cad. Saúde Pública (Online) ; 39(1): e00169622, 2023. graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1421013

RESUMO

No Brasil, o Sistema de Vigilância Alimentar e Nutricional (SISVAN) é a ferramenta central para coletar e consolidar informações sobre o estado nutricional e alimentação da população atendida pelos serviços de atenção básica no país. Este trabalho explora dados do SISVAN com o objetivo de analisar o potencial do sistema como ferramenta de monitoramento do estado nutricional de crianças e adolescentes no país. Procura-se avaliar a evolução da taxa de cobertura do sistema em relação à população para diferentes faixas etárias e regiões geográficas, como essa taxa de cobertura varia conforme as características dos municípios brasileiros e em que medida os resultados provenientes do SISVAN diferem de pesquisas amostrais representativas da população. Apresentamos quatro principais resultados. Primeiro, documentamos que, entre 2008 e 2019, o SISVAN expandiu significativamente a sua cobertura, mas houve uma queda expressiva em 2020 até níveis similares aos do início da série. Segundo, nossos resultados apontam que a cobertura não é homogênea, sendo maior nas regiões Norte e Nordeste e entre crianças de menor idade. Terceiro, existe uma associação sistemática entre características dos municípios e o nível de cobertura do sistema. Por último, os resultados do SISVAN divergem dos apresentados por pesquisas representativas da população geral. Em conjunto, os resultados deste estudo apontam para a necessidade de refinar os instrumentos de vigilância nutricional sobre crianças e adolescentes no Brasil.


In Brazil, the Food and Nutrition Surveillance System (SISVAN) is the main tool in collecting and consolidating information on the nutritional status and the feeding habits of the population encompassed by primary health care services of the country. This study explores data from SISVAN to analyze the system's potential as a tool for monitoring the nutritional status of children and adolescents in the country. We seek to evaluate the evolution of the system's coverage rate in relation to the population regarding different age groups and geographic regions, how this coverage rate varies according to the characteristics of the Brazilian municipalities, and to what extent the results from SISVAN differ from representative sample surveys of the population. We present four main results. First, we documented that from 2008 to 2019, SISVAN significantly expanded its coverage; with a significant decrease, however, in 2020, reaching levels similar to those at the beginning of the series. Second, our results indicate that coverage is not homogeneous, being higher in the North and Northeast regions and among underage children. Third, there is a systematic association between the characteristics of the municipalities and the level of coverage of the system. Finally, SISVAN results differ from those presented by surveys representative of the general population. Jointly, the results of this study point to the need to refine the nutritional surveillance instruments on children and adolescents in Brazil.


En Brasil, el Sistema de Vigilancia Alimentaria y Nutricional (SISVAN) es una herramienta clave para recolectar y consolidar información sobre el estado nutricional y la dieta de la población atendida por los servicios de atención primaria en el país. Este trabajo analiza, a partir de los datos de SISVAN, el potencial del sistema como una herramienta de seguimiento del estado nutricional de niños y adolescentes del país. Se pretende evaluar la evolución de la tasa de cobertura del sistema con relación a la población según diferentes grupos de edad y regiones geográficas, cómo varía esta tasa de cobertura según las características de los municipios brasileños y en qué medida los resultados de SISVAN se diferencian de las encuestas por muestreo representativas de la población. Se presentan cuatro resultados principales. Primero, entre 2008 y 2019, SISVAN amplió significativamente su cobertura, pero en 2020 hubo un significativo descenso a niveles similares a los del inicio de la serie. Segundo, los resultados indican que la cobertura no es homogénea, y hay una mayor cobertura en las regiones Norte y Nordeste del país, entre los niños más pequeños. Tercero, existe una asociación sistemática entre las características de los municipios y el nivel de cobertura del sistema. Cuarto, los resultados de SISVAN se diferencian de los presentados en las encuestas representativas de la población general. Los resultados de este estudio apuntan que es necesario mejorar las herramientas de vigilancia nutricional de niños y adolescentes en Brasil.

5.
Front Chem ; 10: 915335, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35860631

RESUMO

This paper reports on the preparation of Er3+/Yb3+/Tm3+, Er3+/Yb3+/Nd3+, and Er3+/Tm3+/Nd3+ triply doped and Er3+-doped SiO2-Ta2O5 glass ceramic nanocomposites and active planar waveguides by the sol-gel process using the dip-coating technique as deposition method. The investigation of their structural, morphological, and luminescent properties using XRD, AFM, and photoluminescence analysis, are reported here. The XRD results showed the presence of L-Ta2O5 nanocrystals dispersed in the SiO2-based amorphous host for all the nanocomposites and films. The rare earth ion (RE3+) doping concentration affected both the crystallinity, and the crystallite sizes of the Ta2O5 dispersed into SiO2-Ta2O5 nanocomposites and waveguides. AFM characterization revealed crack free and smooth surface roughness and differences in viscoelasticity on the Er3+-doped SiO2-Ta2O5 films surface, which allows the identification of Ta2O5 nanocrystals on the SiO2 amorphous host. The Er3+ doped and triply doped SiO2-Ta2O5 nanocomposites displayed broad- and super broadband NIR emissions with a FWHM up to 173 nm achieved in the telecom wavelengths. The lifetime of the 4I13/2 emitting level of the Er3+-doped SiO2-Ta2O5 waveguides is strongly dependent on Er3+ concentration and an emission quenching was negligible up to 0.81 mol%. The structural and luminescent investigations indicated that RE3+-doped SiO2-Ta2O5 glass ceramics are promising candidates for photonic applications in optical devices operating in wide wavelengths at the telecom bands.

6.
Mar Pollut Bull ; 180: 113753, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35598511

RESUMO

This study provides the first assessment of the impact of the worst oil spill ever faced by Brazilian sandy beaches by analyzing changes in the community structure of intertidal macroinfauna. Four sandy beaches were sampled three times after the oil spill, and the results were compared with previous data. The first sampling, conducted 15 days after the oil spill (October 2019), showed higher abundance of macroinfauna, which decreased in subsequent sampling conducted 60 and 120 days later, but never reached a lower level than in previous sampling. Of the macroinfauna species, Scolelepis sp. was most abundant in October 2019, while Donax gemmula was predominant during the other time periods. Changes observed in macroinfauna were due to natural fluctuations rather than a response to this disturbance. Characteristics of both the oil spill and macroinfauna contributed to the lack of acute impacts.


Assuntos
Bivalves , Poluição por Petróleo , Animais , Brasil
7.
Nat Commun ; 12(1): 6998, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34853317

RESUMO

Bacteria have evolved toxins to outcompete other bacteria or to hijack host cell pathways. One broad family of bacterial polymorphic toxins gathers multidomain proteins with a modular organization, comprising a C-terminal toxin domain fused to a N-terminal domain that adapts to the delivery apparatus. Polymorphic toxins include bacteriocins, contact-dependent growth inhibition systems, and specialized Hcp, VgrG, PAAR or Rhs Type VI secretion (T6SS) components. We recently described and characterized Tre23, a toxin domain fused to a T6SS-associated Rhs protein in Photorhabdus laumondii, Rhs1. Here, we show that Rhs1 forms a complex with the T6SS spike protein VgrG and the EagR chaperone. Using truncation derivatives and cross-linking mass spectrometry, we demonstrate that VgrG-EagR-Rhs1 complex formation requires the VgrG C-terminal ß-helix and the Rhs1 N-terminal region. We then report the cryo-electron-microscopy structure of the Rhs1-EagR complex, demonstrating that the Rhs1 central region forms a ß-barrel cage-like structure that encapsulates the C-terminal toxin domain, and provide evidence for processing of the Rhs1 protein through aspartyl autoproteolysis. We propose a model for Rhs1 loading on the T6SS, transport and delivery into the target cell.


Assuntos
Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Photorhabdus/metabolismo , Sistemas de Secreção Tipo VI/química , Adaptação Fisiológica , Proteínas de Bactérias/química , Toxinas Bacterianas/classificação , Toxinas Bacterianas/genética , Bacteriocinas/química , Inibição de Contato , Microscopia Crioeletrônica , Espectrometria de Massas , Modelos Moleculares , Photorhabdus/genética , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo
8.
J Affect Disord ; 294: 695-700, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343927

RESUMO

BACKGROUND: To analyze the association between temperament (emotional and affective) and scrutinize the progression from suicide ideation to attempt, by using data from a large internet-based sample. METHODS: It is a cross-sectional study, based on the Brazilian Internet Study on Temperament and Psychopathology (BRAINSTEP). Temperament was assessed by the Affective and Emotional Composite Temperament Scale (AFECTS), and life-long suicidal behavior was determined by the adapted Suicidal Behaviors Questionnaire (SBQ-17). Odds ratios were obtained through multivariate logistic regression and a multiple linear regression were used in the analysis. According to the "ideation-to-action framework", we performed analyzes using two different reference groups: no suicidal ideation and suicidal ideation. RESULTS: The affective temperaments that showed the greatest association with suicide attempts were depressive, cyclothymic, and volatile. The temperaments that reflected higher associations for progression from ideation to suicide attempt were cyclothymic, depressive, and euphoric. Sensitivity was manifested as the emotional temperament with the strongest positive association with the severity of suicidal behavior, followed by desire and control. Stability was estimated as the emotional trait with the strongest negative association with the severity of suicidal behavior. LIMITATIONS: It is not a population based sample. BRAINSTEP is a self-selected sample whose participants are mostly women, who are highly educated and young. CONCLUSIONS: Our results suggest that temperament assessment using AFECT model may be relevant to assess the risk for the progression from ideation to suicide attempts. These results strengthen the "ideation-to-action" framework that risk factors to suicide ideators can differ from suicide attempters.


Assuntos
Tentativa de Suicídio , Temperamento , Estudos Transversais , Emoções , Feminino , Humanos , Ideação Suicida
9.
Int J Mol Sci ; 21(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233496

RESUMO

Ferroptosis is a type of cell death that was described less than a decade ago. It is caused by the excess of free intracellular iron that leads to lipid (hydro) peroxidation. Iron is essential as a redox metal in several physiological functions. The brain is one of the organs known to be affected by iron homeostatic balance disruption. Since the 1960s, increased concentration of iron in the central nervous system has been associated with oxidative stress, oxidation of proteins and lipids, and cell death. Here, we review the main mechanisms involved in the process of ferroptosis such as lipid peroxidation, glutathione peroxidase 4 enzyme activity, and iron metabolism. Moreover, the association of ferroptosis with the pathophysiology of some neurodegenerative diseases, namely Alzheimer's, Parkinson's, and Huntington's diseases, has also been addressed.


Assuntos
Doença de Alzheimer/metabolismo , Ferroptose , Doença de Huntington/metabolismo , Ferro/metabolismo , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Araquidonato 15-Lipoxigenase/genética , Araquidonato 15-Lipoxigenase/metabolismo , Ácido Araquidônico/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Membrana Celular/metabolismo , Membrana Celular/patologia , Ácidos Graxos Insaturados/metabolismo , Glutationa/metabolismo , Humanos , Doença de Huntington/genética , Doença de Huntington/patologia , Peroxidação de Lipídeos , Neurônios/patologia , Estresse Oxidativo , Doença de Parkinson/genética , Doença de Parkinson/patologia , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/deficiência
10.
Arq. ciências saúde UNIPAR ; 23(3): [163-169], set-dez. 2019.
Artigo em Português | LILACS | ID: biblio-1046144

RESUMO

O objetivo do presente estudo foi verificar se o índice de massa corporal e a atividade física influenciam no desenvolvimento motor e na aptidão física de crianças. Participaram 64 crianças com idade entre 9 e 10 anos de ambos os sexos, sendo avaliados: nível de atividade física, estado nutricional, aptidão física (força, flexibilidade e resistência) e desenvolvimento motor. A amostra foi dividida em quatro grupos, estratificados pelo nível de atividade física e estado nutricional. Os dados foram comparados por meio do teste de Kruskal-Wallis (p<0,05). Os resultados apontaram que 34,4% das crianças apresentaram massa corporal acima dos valores normativos e 50% eram sedentárias. A massa corporal elevada influenciou negativamente na resistência e na habilidade de controle de objetos, apesar que o nível de atividade física diminui o impacto da obesidade na força e na habilidade de locomoção. A flexibilidade não foi influenciada. Conclui-se que atividade física e estado nutricional podem influenciar na aptidão física e no desenvolvimento motor de crianças.


The purpose of this study was to assess the influence of body mass index and physical activity levels in the motor development and physical fitness of children. The study had the participation of 64 children aged between 9 and 10 years of both genders: physical activity level, nutritional status, physical fitness (strength, flexibility and endurance), and motor development. The participants were divided into four groups, stratified by level of physical activity and nutritional status. The data were compared using the Kruskal-Wallis test (p <0.05). Results: 34.4% of the children had body mass above normative values, ​​and 50% were sedentary. High body mass has negatively influenced the resistance and ability to control objects, although the level of physical activity decreases the impact of obesity on strength and ability to move. Flexibility was not influenced. Conclusion: physical activity and nutritional status may influence the physical fitness and motor development in children.


Assuntos
Humanos , Masculino , Feminino , Criança , Índice de Massa Corporal , Aptidão Física , Atividade Motora , Exercício Físico , Teste de Esforço/métodos , Força Muscular , Obesidade Infantil , Locomoção
11.
J Mol Biol ; 431(2): 351-367, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30471256

RESUMO

C4-dicarboxylates play a central role in cellular physiology as key metabolic intermediates. Under aerobic conditions, they participate in the citric acid cycle, while in anaerobic bacteria, they are important in energy-conserving fermentation and respiration processes. Ten different families of secondary transporters have been described to participate in C4-dicarboxylate movement across biological membranes, but only one of these utilizes an extracytoplasmic solute binding protein to achieve high-affinity uptake. Here, we identify the MatBAC system from the photosynthetic bacterium Rhodopseudomonas palustris as the first member of the tripartite tricarboxylate transport family to be involved in C4-dicarboxylate transport. Tryptophan fluorescence spectroscopy showed that MatC, the periplasmic binding protein from this system, binds to l- and d-malate with Kd values of 27 and 21 nM, respectively, the highest reported affinity to date for these C4-dicarboxylates, and to succinate (Kd = 110 nM) and fumarate (Kd = 400 nM). The 2.1-Šcrystal structure of MatC with bound malate shows a high level of substrate coordination, with participation of two water molecules that bridge hydrogen bonds between the ligand proximal carboxylic group and the main chain of two conserved loops in the protein structure. The substrate coordination in MatC correlates with the binding data and explains the protein's selectivity for different substrates and respective binding affinities. Our results reveal a new function in C4-dicarboxylate transport by members of the poorly characterized tripartite tricarboxylate transport family, which are widely distributed in bacterial genomes but for which details of structure-function relationships and transport mechanisms have been lacking.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Periplasma/metabolismo , Proteínas Periplásmicas de Ligação/metabolismo , Rodopseudomonas/metabolismo , Sequência de Aminoácidos , Transporte Biológico/fisiologia , Fumaratos/metabolismo , Malatos/metabolismo , Ácido Succínico/metabolismo
12.
Microb Genom ; 4(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29667925

RESUMO

Lineage-specific expansion (LSE) of protein families is a widespread phenomenon in many eukaryotic genomes, but is generally more limited in bacterial genomes. Here, we report the presence of 434 genes encoding solute-binding proteins (SBPs) from the tripartite tricarboxylate transporter (TTT) family, within the 8.2 Mb genome of the α-proteobacterium Rhodoplanes sp. Z2-YC6860, a gene family over-representation of unprecedented abundance in prokaryotes. Representing over 6 % of the total number of coding sequences, the SBP genes are distributed across the whole genome but are found rarely in low-GC islands, where the gene density for this family is much lower. This observation, and the much higher sequence identity between the 434 Rhodoplanes TTT SBPs compared with the average identity between homologues from different species, is indicative of a key role for LSE in the expansion. The TTT SBP genes were found in the vicinity of genes encoding membrane components of transport systems from different families, as well as regulatory proteins such as histidine-kinases and transcription factors, indicating a broad range of functions around the sensing, response and transport of organic compounds. A smaller expansion of TTT SBPs is known in some species of the ß-proteobacteria Bordetella and we observed similar expansions in other ß-proteobacterial lineages, including members of the genus Comamonas and the industrial biotechnology organism Cupriavidus necator, indicating that strong environmental selection can drive SBP duplication and specialisation from multiple evolutionary starting points.


Assuntos
Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Genes Bacterianos/genética , Hyphomicrobiaceae/genética , Hyphomicrobiaceae/metabolismo , Alphaproteobacteria/genética , Alphaproteobacteria/metabolismo , Proteínas de Bactérias/genética , Bordetella/genética , Comamonas/genética , Cupriavidus necator/genética , Tamanho do Genoma , Genoma Bacteriano , Histidina Quinase/genética , Proteínas Periplásmicas de Ligação/biossíntese , Proteínas Periplásmicas de Ligação/genética , Fatores de Transcrição/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-29479520

RESUMO

The ability to efficiently scavenge nutrients in the host is essential for the viability of any pathogen. All catabolic pathways must begin with the transport of substrate from the environment through the cytoplasmic membrane, a role executed by membrane transporters. Although several classes of cytoplasmic membrane transporters are described, high-affinity uptake of substrates occurs through Solute Binding-Protein (SBP) dependent systems. Three families of SBP dependant transporters are known; the primary ATP-binding cassette (ABC) transporters, and the secondary Tripartite ATP-independent periplasmic (TRAP) transporters and Tripartite Tricarboxylate Transporters (TTT). Far less well understood than the ABC family, the TRAP transporters are found to be abundant among bacteria from marine environments, and the TTT transporters are the most abundant family of proteins in many species of ß-proteobacteria. In this review, recent knowledge about these families is covered, with emphasis on their physiological and structural mechanisms, relating to several examples of relevant uptake systems in pathogenicity and colonization, using the SiaPQM sialic acid uptake system from Haemophilus influenzae and the TctCBA citrate uptake system of Salmonella typhimurium as the prototypes for the TRAP and TTT transporters, respectively. High-throughput analysis of SBPs has recently expanded considerably the range of putative substrates known for TRAP transporters, while the repertoire for the TTT family has yet to be fully explored but both types of systems most commonly transport carboxylates. Specialized spectroscopic techniques and site-directed mutagenesis have enriched our knowledge of the way TRAP binding proteins capture their substrate, while structural comparisons show conserved regions for substrate coordination in both families. Genomic and protein sequence analyses show TTT SBP genes are strikingly overrepresented in some bacteria, especially in the ß-proteobacteria and some α-proteobacteria. The reasons for this are not clear but might be related to a role for these proteins in signaling rather than transport.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/química , Transporte Biológico , Proteínas de Membrana Transportadoras/química , Família Multigênica , Ligação Proteica , Subunidades Proteicas , Relação Estrutura-Atividade , Virulência
14.
FEBS J ; 284(24): 4262-4277, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29082669

RESUMO

The tripartite tricarboxylate transporter (TTT) family is a poorly characterised group of prokaryotic secondary solute transport systems, which employ a periplasmic substrate-binding protein (SBP) for initial ligand recognition. The substrates of only a small number of TTT systems are known and very few SBP structures have been solved, so the mechanisms of SBP-ligand interactions in this family are not well understood. The SBP RPA4515 (AdpC) from Rhodopseudomonas palustris was found by differential scanning fluorescence and isothermal titration calorimetry to bind aliphatic dicarboxylates of a chain length of six to nine carbons, with KD values in the µm range. The highest affinity was found for the C6-dicarboxylate adipate (1,6-hexanedioate). Crystal structures of AdpC, either adipate or 2-oxoadipate bound, revealed a lack of positively charged amino acids in the binding pocket and showed that water molecules are involved in bridging hydrogen bonds to the substrate, a conserved feature in the TTT SBP family that is distinct from other types of SBP. In AdpC, both of the ligand carboxylate groups and a linear chain conformation are needed for coordination in the binding pocket. RT-PCR showed that adpC expression is upregulated by low environmental adipate concentrations, suggesting adipate is a physiologically relevant substrate but as adpC is not genetically linked to any TTT membrane transport genes, the role of AdpC may be in signalling rather than transport. Our data expand the known ligands for TTT systems and identify a novel high-affinity binding protein for adipate, an important industrial chemical intermediate and food additive. DATABASES: Protein structure co-ordinates are available in the PDB under the accession numbers 5OEI and 5OKU.


Assuntos
Adipatos/metabolismo , Transportadores de Ácidos Dicarboxílicos/metabolismo , Proteínas Periplásmicas de Ligação/metabolismo , Rodopseudomonas/metabolismo , Adipatos/farmacologia , Sequência de Aminoácidos , Cristalografia por Raios X , DNA Bacteriano/genética , Transportadores de Ácidos Dicarboxílicos/genética , Ácidos Dicarboxílicos/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Cinética , Ligantes , Modelos Moleculares , Proteínas Periplásmicas de Ligação/química , Proteínas Periplásmicas de Ligação/genética , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Proteínas Recombinantes de Fusão/química , Rodopseudomonas/genética , Relação Estrutura-Atividade , Especificidade por Substrato
15.
Mundo saúde (Impr.) ; 41(3): 267-274, maio, 2017. tab
Artigo em Português | LILACS | ID: biblio-999560

RESUMO

O presente estudo teve por objetivo avaliar o nível de sedentarismo entre estudantes universitários do Rio Grande doSul e os possíveis fatores associados. A amostra estudada foi constituída por universitários de 23 cursos, totalizando358 estudantes (199 mulheres e 159 homens), regularmente matriculados em uma instituição de ensino superior do RioGrande do Sul no ano de 2015. O nível de atividade física foi avaliado por meio do Questionário Internacional de AtividadeFísica (IPAQ) versão curta, sendo que para as demais informações foi aplicado um questionário sociodemográfico. Acomparação entre as proporções de sujeitos ativos e sedentários foi realiza por meio do teste Qui-quadrado com nívelde significância de 5%. O principal resultado do estudo indicou que 41% dos acadêmicos são sedentários, sendo queentre os fatores associados ao sedentarismo está em ser do sexo feminino, ser portador de doença crônica e estudarhá mais de dois anos na instituição. Ainda, entre os homens, estar acima do peso também confere uma associação aosedentarismo. Desta forma, conclui-se que uma grande proporção de estudantes universitários do Rio Grande do Sulencontra-se em nível de sedentarismo, sendo estes resultados similares aos de estudantes de outras regiões do país


The present study aimed to evaluate the level of sedentarism among university students in Rio Grande do Sul and thepossible associated factors. The study sample consisted of university students from 23 courses enrolled in a highereducation institution in Rio Grande do Sul in 2015; totaling 358 students (199 women and 159 men). The level ofphysical activity was assessed through the short version of the International Physical Activity Questionnaire (IPAQ),and for other information, a sociodemographic questionnaire was applied. The comparison between the proportions ofactive and sedentary individuals was performed using the chi-square test with a significance level of 5%. The main resultof the study indicated that 41% of the students are sedentary, and some of the factors associated with the sedentarylifestyle are being female, having a chronic disease, and studying for more than two years in the institution. Still, amongmen, being overweight also confers an association with a sedentary lifestyle. Thus, we conclude that a large proportionof university students in Rio Grande do Sul are on a sedentary level, and these results are similar to those in other regions of the country


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Estudantes , Exercício Físico , Comportamento Sedentário
16.
Rev. bras. oftalmol ; 76(2): 74-80, Mar.-Apr. 2017. tab, graf
Artigo em Português | LILACS | ID: biblio-899051

RESUMO

Resumo Objetivo: Este trabalho tem como objetivo avaliar o conhecimento de médicos com formação nas especialidades de clínica médica e cirúrgica acerca do processo de doação de córneas, bem como avaliar a segurança por parte desses profissionais neste processo e, se há insegurança, os motivos para tal. Métodos: A pesquisa se baseia na coleta de dados por meio de um questionário com dez perguntas de múltipla escolha sobre o processo de doação de córneas, sendo duas perguntas sobre segurança no processo de doação. A amostra consiste em 60 profissionais médicos do Hospital Universitário HU-UFSC selecionados por conveniência e não probabilística. Resultados: Os entrevistados obtiveram uma média de acertos de 72,2%. Em relação à segurança no processo de doação de córneas, 41 (68,66%) referem se sentir seguros quanto ao mesmo e 19 (31,33%) revelam não ter segurança para essa condição. Do total de entrevistados que revelaram insegurança no processo de doação de córneas, 13 apontaram como fator contribuinte pouca informação sobre o assunto na faculdade. Alguns temas relevantes a respeito do assunto se mostraram insuficientes e 31,66% dos entrevistados se revelaram inseguros frente a uma situação que envolva doação de córneas. Conclusão: Esses achados sugerem a necessidade de melhorar o nível de informação transmitida durante o curso de graduação acerca do processo de doação de córneas, a fim de conscientizar, melhorar o conhecimento e promover segurança frente a um potencial doador.


Abstract Objective: This study aims to evaluate the knowledge of physicians trained in Internal medicine and General surgery specialties about cornea donation process clinic, as well as to assess the confidence by these professionals in this process and, if there is uncertainty, the reasons for this. Methods: The research is based on data collected through a questionnaire with ten multiple choice questions about the process of cornea donation, in which two questions are about confidence in the donation process. The sample consists of 60 physicians of University Hospital HU-UFSC selected for convenience and non-probability. Results: Respondents had a mean score of 72.2%. Regarding confidence in the donation of corneas, 41 (68.66%) feel confident in the donation process and 19 (31.33%) did not reveal safety for this condition. From the total of respondents who revealed insecurity in cornea donation process, 13 of these indicated as a contributing factor little information on the subject in college. Some relevant themes on the subject are insufficient and 31.66% of the interviewees proved insecure against a situation involving the corneal donation. Conclusion: This finds suggest the need to improve the level of information transmitted during the undergraduate course about the process of corneal donation in order to raise awareness, improve knowledge and promote confidence when facing a potential donor.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Médicos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Córnea , Coleta de Tecidos e Órgãos/métodos , Oftalmologia/normas , Oftalmologia/estatística & dados numéricos , Competência Profissional , Epidemiologia Descritiva , Estudos Transversais , Inquéritos e Questionários , Transplante de Córnea , Clínicos Gerais , Estudo Observacional , Cirurgiões , Hospitais Universitários
17.
Zootaxa ; 4111(2): 145-57, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-27394904

RESUMO

Based on the paratype of Bledius caribbeanus, its distribution is corrected, not occurring in Brazil, and its morphology is compared to B. hermani; two new Bledius species from the coast of Brazil are described; B. externus is redescribed and here for the first time recorded in Brazil and the key to identification of Brazilian coastal Bledius is updated.


Assuntos
Besouros/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Brasil , Besouros/anatomia & histologia , Besouros/crescimento & desenvolvimento , Ecossistema , Feminino , Masculino , Tamanho do Órgão
18.
Rev Biol Trop ; 62(1): 59-68, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24912343

RESUMO

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.


Assuntos
Tamanho Corporal , Comportamento Alimentar/fisiologia , Estações do Ano , Estrelas-do-Mar/anatomia & histologia , Animais , Brasil , Conteúdo Gastrointestinal , Estrelas-do-Mar/classificação , Estrelas-do-Mar/fisiologia
19.
Rev. biol. trop ; 62(1): 73-83, ene.-mar. 2014. graf, tab
Artigo em Inglês | LILACS | ID: lil-715415

RESUMO

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.


La estrella de mar Astropecten marginatus presenta una distribución neotropical y debido a su abundancia es frecuente encontrarla como captura incidental durante actividades de pesca de arrastre; actividad por la cual se encuentra amenazada en muchos lugares a lo largo de la costa brasileña. En este estudio se analizaron las variaciones estacionales de la estructura de la población y se determinaron los principales componentes de la dieta de A. marginatus frente a la costa de Paraná, sur de Brasil. Las muestras analizadas provinieron de las capturas de la pesca de arrastre recogidas en febrero (verano), abril (otoño), junio (invierno) y octubre (primavera) 2008. De cada individuo se midió la longitud y se pesó, posteriormente se analizó el contenido estomacal de 10 organismos de cada una de las dos clases de talla más frecuentes por cada temporada. Se analizaron 994 ejemplares de A. marginatus, los cuales presentaron una longitud que varió entre 7.0-56.2mm, con mayor frecuencia de individuos entre 20.1-25mm. Los organismos mayores (>40mm) se encontraron solamente en la primavera, mientras aquellos con talla inferior a los 10mm se obtuvieron durante el otoño y el invierno. El peso de los individuos se mantuvo entre los 0.1-15.3g. La relación entre el peso y talla mostró un crecimiento alométrico negativo (b<2.54). En cuanto a la dieta, esta especie consumió un total de once presas, de las cuales los cumáceos y moluscos fueron los grupos más consumidos. Una mayor cantidad de presas exploradas se registró en el invierno-primavera de los períodos de verano-otoño. El predominio de la presa cambió de gasterópodos (verano y otoño) a cumáceos (invierno y primavera). Las diferencias estacionales en el patrón de alimentación podrían estar asociadas a una baja disponibilidad de presas y a los cambios en las tasas de alimentación, lo cual se ve reflejado en algunos rasgos biológicos, como el pequeño tamaño del cuerpo esta población.


Assuntos
Animais , Tamanho Corporal , Comportamento Alimentar/fisiologia , Estações do Ano , Estrelas-do-Mar/anatomia & histologia , Brasil , Conteúdo Gastrointestinal , Estrelas-do-Mar/classificação , Estrelas-do-Mar/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...