1,707 research outputs found

    Rapid Experimental Evolution of Pesticide Resistance in C. elegans Entails No Costs and Affects the Mating System

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    Pesticide resistance is a major concern in natural populations and a model trait to study adaptation. Despite the importance of this trait, the dynamics of its evolution and of its ecological consequences remain largely unstudied. To fill this gap, we performed experimental evolution with replicated populations of Caenorhabditis elegans exposed to the pesticide Levamisole during 20 generations. Exposure to Levamisole resulted in decreased survival, fecundity and male frequency, which declined from 30% to zero. This was not due to differential susceptibility of males. Rather, the drug affected mobility, resulting in fewer encounters, probably leading to reduced outcrossing rates. Adaptation, i.e., increased survival and fecundity, occurred within 10 and 20 generations, respectively. Male frequency also increased by generation 20. Adaptation costs were undetected in the ancestral environment and in presence of Ivermectin, another widely-used pesticide with an opposite physiological effect. Our results demonstrate that pesticide resistance can evolve at an extremely rapid pace. Furthermore, we unravel the effects of behaviour on life-history traits and test the environmental dependence of adaptation costs. This study establishes experimental evolution as a powerful tool to tackle pesticide resistance, and paves the way to further investigations manipulating environmental and/or genetic factors underlying adaptation to pesticides

    Increased exhalation of hydrogen peroxide in healthy subjects following cigarette consumption

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    CONTEXT: Increased hydrogen peroxide has been described in the expired breath condensate (H2O2-E) of several lung conditions, such as acute respiratory distress syndrome, chronic obstructive pulmonary disease and asthma. This technique has been advocated as being a simple method for documenting airway inflammation. OBJECTIVE: To evaluate H2O2-E in healthy cigarette smokers, and to determine the acute effects of the consumption of one cigarette on H2O2-E levels. TYPE OF STUDY: Prospective, controlled trial. SETTING: A pulmonary function laboratory in a University Hospital. PARTICIPANTS: Two groups of healthy volunteers: individuals who had never smoked (NS; n=10; 4 men; age = 30.6 ± 6.2 years) and current cigarette smokers (S; n=12; 7 men; age = 38.7 ± 9.8). None of the volunteers had respiratory symptoms and all showed normal spirometric tests. INTERVENTION: Expired air was collected from all volunteers through a face mask and a plastic collecting system leading into a flask with dry ice and pure ethanol. Samples from the group S were collected twice, before and half an hour after the combustion of one cigarette. MAIN MEASUREMENTS: Expired hydrogen peroxide using the Gallati and Pracht method. RESULTS: The S and NS groups showed comparable levels of H2O2-E at basal conditions [NS = 0.74 muM (DP 0.24) vs. S = 0.75 muM (DP 0.31)]. The smokers showed a significant increase in H2O2-E levels half an hour after the consumption of only one cigarette [0.75 muM (DP 0.31) vs. 0.95 muM (DP 0.22)]. CONCLUSION: The present results are consistent with the concept that smokers increase oxidative stress with elevated production of reactive oxygen species, contributing to the development of smoking-related disorders.CONTEXTO: Elevações do peróxido de hidrogênio exalado (H2O2-E) tem sido descritas em diversas doenças pulmonares tais como a síndrome do desconforto respiratório agudo, doença pulmonar obstrutiva crônica e asma. Essa técnica tem sido preconizada como um método simples capaz de refletir inflamação ao nível das vias aéreas. OBJETIVO: Avaliar os níveis de H2O2-E em indivíduos normais e determinar os efeitos agudos do consumo de um cigarro sobre seus valores. TIPO DE ESTUDO: Ensaio clínico, prospectivo, controlado. LOCAL: Laboratório de função pulmonar de um Hospital Universitário. PARTICIPANTES: Dois grupos de voluntários sadios: indivíduos que nunca fumaram [NS; n = 10; 4 homens; idade = 30,6 anos (DP 6,2)] e indivíduos fumantes atuais [S; n = 12; 7 homens; idade = 38,7 anos (DP 9,8)]. Todos os voluntários não apresentavam sintomas respiratórios e exibiam testes espirométricos dentro da normalidade. INTERVENÇÃO: Ar expirado foi coletado de todos os voluntários utilizando-se uma máscara facial e um sistema colocado em um frasco com gelo seco e etanol absoluto. Amostras do grupo S foram coletadas duas vezes, antes e meia hora após o consumo de um cigarro. VARIÁVEIS ESTUDADAS: Peróxido de hidrogênio expirado utilizando-se o método de Gallati e Pracht. RESULTADOS: Ambos os grupos mostraram níveis comparáveis de H2O2-E em condições basais [NS = 0,74 miM (DP 0,24) vs. S = 0,75 miM (DP 0,31)]. Os fumantes mostraram um aumento significante dos níveis de H2O2-E meia hora após o consumo de apenas um cigarro [0,75 miM (DP 0,31) vs. 0,95 miM (DP 0,22)]. CONCLUSÃO: Os resultados obtidos estão de acordo com o conceito de que o consumo de cigarros aumenta o estresse oxidativo com produção elevada de espécies reativas do oxigênio (ROS) contribuindo para o desenvolvimento de doenças relacionadas ao tabagismo.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Pulmonary DivisionUniversity of São Paulo Medical School of Ribeirão Preto Department of MedicineUNIFESP, EPM, Pulmonary DivisionSciEL

    Proliferative verrucous leukoplakia may initially mimic lichenoid reactions

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    Proliferative verrucous leukoplakia is an intriguing disease, which occurs particularly in women aged greater than 60 years, is not associated with tobacco and alcohol, and has a high risk of recurrence and malignant transformation. Although it is well known that the typical presentation is characterized by multifocal and verrucous white lesions, there is no description that its initial clinical presentation may simulate a lichenoid reaction.Proliferative verrucous leukoplakia is an intriguing disease, which occurs particularly in women aged greater than 60 years, is not associated with tobacco and alcohol, and has a high risk of recurrence and malignant transformation. Although it is well known that the typical presentation is characterized by multifocal and verrucous white lesions, there is no description that its initial clinical presentation may simulate a lichenoid reaction31086186

    Assessment of Cytotoxicity, Fetotoxicity, and Teratogenicity of Plathymenia reticulata Benth Barks Aqueous Extract

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    Scientific assessment of harmful interactions of chemicals over the entire reproductive cycle are divided into three segments based on the period: from premating and mating to implantation (I), from implantation to major organogenesis (II), and late pregnancy and postnatal development (III). We combined the segments I and II to assess Plathymenia reticulata aqueous extract safety. in order to investigate reproductive toxicity (segment I), pregnant rats received orally 0.5 or 1.0 g/kg of extract, daily, during 18 days. These concentrations were determined by a preliminary in vitro LD50 test in CHO-k1 cells. A control group received deionized water. the offspring was removed at the 19th day, by caesarean, and a teratology study (segment II) was carried out. the corpora lutea, implants, resorptions, live, and dead fetuses were then counted. Placenta and fetuses were weighted. External and visceral morphology were provided by the fixation of fetuses in Bouin, whereas skeletal analysis was carried out on the diaphanizated ones. the increase in the weights of placenta and fetuses was the only abnormality observed. Since there was no sign of alteration on reproduction parameters at our experimental conditions, we conclude that P. reticulata aqueous extract is safe at 0.5 to 1.0 g/kg and is not considered teratogenic.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Sorocaba, Postgrad Program Pharmaceut Sci, UNISO, BR-18023000 Sorocaba, SP, BrazilFed Univ Pampa, CIPBiotec, UNIPAMPA, BR-97300000 Sao Gabriel, RS, BrazilFed Univ Tocantins, PGCiamb, Postgrad Course Environm Sci, BR-77001090 Tocantins, BrazilUniversidade Federal de São Paulo, UNIFESP, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, UNIFESP, BR-09972270 Diadema, SP, BrazilFAPESP: 04/09705-8FAPESP: 07/53883-6FAPESP: 08/52643-4CNPq: 35.0798/2004-4Web of Scienc

    Educação ambiental: a questão do lixo na agrovila Princesa do Xngu, zona rural da cidade de Altamira-PA.

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    RESUMO O presente trabalho visa fazer um estudo de caso sobre a importância do lixo como pratica de educação ambiental na agrovila Princesa do Xingu, zona rural da cidade de Altamira-PA. Com objetivos de identificar que tipo de lixo é mais produzido, as formas de descartes, verificar se fazem a separação do lixo e de levantar se reciclam ou reutilizam o lixo. O método de analise foi o estudo de caso, no qual serve para responder questionamentos que o pesquisador não tem muito controle sobre o fenômeno estudado, ou seja, é um método de pesquisa de natureza empírica que investiga um fenômeno. O estudo descrito neste artigo tem como escopo discutir a Educação Ambiental no contexto do lixo produzido pelos moradores da Agrovila Princesa do Xingu, indicando caminhos e alternativas que oportunizem intervir e transformar a realidade. É indiscutível a necessidade de se adotar medidas eficazes para alterar o rumo da destruição do meio ambiente. A educação ambiental tem o importante papel de transformar a realidade, formando cidadãos críticos, conscientes em relação ao meio em que vivem. O presente trabalho é fruto de uma pesquisa de campo que evidencia a responsabilidade dos pesquisados na busca de alternativas de ação possíveis de serem aplicadas na realidade de nosso cotidiano e que transformem a realidade através da conscientização ambiental dos todos. Palavras-chaves: Agrovila Princesa do Xingu. Educação Ambiental. Lixo.  ABSTRACTThe following paper intends to display ways of minimizing environmental impacts through an Environmental Management System (EMS) implemented by companies that cause such impacts as well as the importance of the environmental auditing process following up such management. Knowing the EMS dynamics is going to bring significant advantages for the environment, for the company that develops it, and for the people who, directly or indirectly, interacts with such initiative. Thus, the study is going to describe the concept of environmental impact and its consequences, how an EMS works, and the execution and advantages of an environmental auditing. It is a theoretical research that has gone through articles, books, thesis, dissertations, as well as the pertinent legislation to the proposed theme and it was observed that the benefits a company has, when it has its EMS running efficiently. Finally, the paper initiates a discussion on the importance of the implementation of an EMS for companies to solidify themselves within the market they belong.Keywords: Environmental Impact. Environmental Management System. Environmental Auditing.

    cGVHD-related caries and its shared features with other 'dry-mouth'-related caries

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    CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSeveral systemic diseases and their medical treatment may predispose the development of aggressive dental caries. Head and neck radiotherapy, chemotherapy, Sjögren's syndrome and long-standing treatment with drugs that induce hyposalivation are some of these conditions. The aim of this article is to describe the clinical features of five patients who developed chronic graft-versus-host-disease (cGVHD) as a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and, in spite of close dental follow-up, subsequently developed rampant caries. In these cases, the restorations showed early failure and the caries still progressed until generalized teeth destruction. The majority of the teeth therefore had to be extracted due to advanced dental caries and rapid clinical progression. Herein the term cGVHD-related caries is proposed to describe this under-recognized complication of cancer treatment that may evolve in allo-HSCT recipients that develop cGVHD. This condition is poorly recognized in the literature and may represent the final result of the clustering of oral complications in cGVHD patients, including mucositis, oral pain, hyposalivation, taste loss and oral infections, leading to rampant caries due to impaired oral hygiene and increased intake of highly cariogenic food. Consequently, the knowledge of this oral complication should improve the medical and dental management of cGVHD oral manifestations and improve the quality of life of patients with this post allo-HSCT complication.Several systemic diseases and their medical treatment may predispose the development of aggressive dental caries. Head and neck radiotherapy, chemotherapy, Sjögren's syndrome and long-standing treatment with drugs that induce hyposalivation are some of these conditions. The aim of this article is to describe the clinical features of five patients who developed chronic graft-versus-host-disease (cGVHD) as a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and, in spite of close dental follow-up, subsequently developed rampant caries. In these cases, the restorations showed early failure and the caries still progressed until generalized teeth destruction. The majority of the teeth therefore had to be extracted due to advanced dental caries and rapid clinical progression. Herein the term "cGVHD-related caries" is proposed to describe this under-recognized complication of cancer treatment that may evolve in allo-HSCT recipients that develop cGVHD. This condition is poorly recognized in the literature and may represent the final result of the clustering of oral complications in cGVHD patients, including mucositis, oral pain, hyposalivation, taste loss and oral infections, leading to rampant caries due to impaired oral hygiene and increased intake of highly cariogenic food. Consequently, the knowledge of this oral complication should improve the medical and dental management of cGVHD oral manifestations and improve the quality of life of patients with this post allo-HSCT complication264435440CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOPROEX 758/20122013/18402-8Diversas doenças sistêmicas e seus tratamentos podem predispor ao desenvolvimento de cáries dentárias agressivas. A radioterapia de cabeça e pescoço, quimioterapia, síndrome de Sjögren e tratamentos prolongados com as drogas que induzem a hipossalivação são algumas destas condições. O objetivo deste artigo é descrever as características clínicas de cinco pacientes que desenvolveram doença do enxerto contra hospedeiro crônica (DECHc) como uma complicação do transplante alogênico de células-tronco hematopoiéticas (aloTCTH) e, apesar do acompanhamento periódico com dentistas, desenvolveram cáries rampantes. Nestes casos relatados, as restaurações mostraram falhas precoces e as cáries continuaram progredindo até a destruição generalizada dos dentes. A maioria dos dentes, portanto, foi extraída devido à cárie avançada e rápida progressão clínica. Neste artigo, o termo "cáries relacionadas à DECHc" é proposto para descrever esta complicação pouco conhecida do tratamento do câncer, que se manifesta em receptores de TCTH que desenvolvem DECHc. Esta condição é pouco reconhecida na literatura e pode representar o resultado final do agrupamento das complicações bucais em pacientes com DECHc, incluindo mucosite, dor oral, hipossalivação, perda de paladar e infecções orais, levando à cárie rampante devido à dificuldade de higiene oral e aumento da ingestão de alimentos altamente cariogênicos. Por consequência, o conhecimento desta complicação oral deve melhorar os tratamentos médico e odontológico das manifestações bucais da DECHc e melhorar a qualidade de vida dos pacientes com esta complicação após o TCT

    Body mass index categories and attained height in Portuguese adults

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    Objective: To analyze the associations between height and BMI categories in a Portuguese representative sample. Methods: This is a cross-sectional study with a representative sample of 32,644 Portuguese adults (52.4% females). Sociodemographic and lifestyle characteristics were obtained along with self-reported height and weight. We performed generalized linear models to assess the differences in attained height across BMI categories; analyses were adjusted for age, gender, education, family income per month, proxy reporting information, dietary patterns, and smoking. Results: BMI categories included underweight and normal weight (46.4%), overweight (37.6%), obese class I and II (15.2%), and obese class III (0.8%). Adults with normal weight had a significantly higher height (females +7 cm and males +5 cm) when compared to obese class III. As BMI categories increased, height decreased. In females and males, after adjusting for confounders, estimates of attained height decreased when compared to the unadjusted model (beta = -0.049, 95% CI = -0.050; -0.049 and beta = -0.030, 95% CI = -0.031; -0.029, respectively), although they remained still significant. Conclusion: Our results suggest a significant difference in attained height between BMI categories. Future intervention programs aiming at preventing overweight and obesity should monitor sociodemographic, health and environmental conditions that affect attained height potential.- (undefined
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