54 research outputs found
Effect of glyphosate on lipoxygenase of cowpea seed
Foi obtida, com solução de CaCl2 a 0,68 mM e pH 7,5, a atividade máxima de lipoxigenase em sementes de caupi (Vigna unguiculata (L.) Walp). Foram analisadas sementes durante a germinação, e observou-se que a atividade específica de lipoxigenase diminuiu durante o processo. Sementes de plantas tratadas com o herbicida glifosato (N - (fosfonometil) glicina) como dessecante mostraram significante aumento da atividade específica de lipoxigenase. Isto pode ser resultado do efeito do herbicida nas plantas. Tal conclusão é baseada no fato de que a. a lipoxigenase, que teve sua atividade específica aumentada pelo glifosato, pode promover a formação do ácido 12-oxo-fitodienóico; b. este, por sua vez, é um possível precursor do ácido jasmônico, um regulador de crescimento que promove senescência em plantas, explicando-se, desta maneira, a ação do herbicida nelas. Pelo método utilizado, não foi encontrada a enzima em folhas ou outras partes verdes das plantas. The predominant cowpea seed lipoxygenase was optimally activated by calcium at 0.68 mM and at pH 7.5. Seeds were analyzed during germinaton and showed a decrease in lipoxygenase specific activity with time. Seeds from plants treated with the herbicide glyphosate (N - (phosphonomethyl) glycine) showed a significant increase in lipoxygenase content. This could have been a result of senescence, or the effects of the herbicide on those plants. Such a conclusion is basead on findings that a. lipoxygenase, the activity of which was enhanced by glyphosate, has been reported to promote formation of 12-oxo-phytodienoic acid, and b. 12-oxo-phytodienoic acid has been proposed to be a precursor of jasmonic acid, a growth regulator which promotes senescence of plants. With the assay technique utilized, no lipoxygenase was found in mature leaves.
SORPTION OF S-TRIAZINES IN BRAZILIAN RAINFOREST SOILS
This research was conducted to evaluate the sorption of Ametryn, Atrazine, Simazine, Prometrine and Metamitron to soils from "Mata Atlântica" at Ubatuba region (Atlantic rainforest soils), employing the batch equilibrium approach. The herbicides were weakly retained in soils with low soil organic matter (SOM) content and thus presenting high potential to water contamination. All herbicides have shown high Koc at Typic Humaquepts soil, the higher in SOM content. The sorption isotherms for the herbicides at Typic Humaquepts soil suggested specific interactions between herbicides and SOM probably with partial protonation of herbicides followed by ion-exchange processes and/or hydrogen bonding formation of hydroxyl groups on the SOM surface.Esta pesquisa foi conduzida para avaliar a sorção de ametrina, atrazina, simazina, prometrina e metamitron em solos de Mata Atlântica na região de Ubatuba, empregando-se o método em batelada. Os herbicidas foram fracamente retidos em solos com baixo teor de matéria orgânica (MO) e, portanto, apresentaram elevado potencial de contaminação da água. Todos os herbicidas mostraram alto valor de Koc em solos da classe Gleissolo Melânico Distrófico, que contém o teor mais elevado de MO. As isotermas de sorção dos herbicidas no Gleissolo Melânico Distrófico sugerem interações específicas entre os herbicidas e a MO, provavelmente com protonação parcial dos herbicidas seguida por processos de troca-iônica e/ou formação de pontes de hidrogênio dos grupos hidroxila sobre a superfície da MO
Longitudinal study of patients with chronic Chagas cardiomyopathy in Brazil (SaMi-Trop project): a cohort profile.
PurposeWe have established a prospective cohort of 1959 patients with chronic Chagas cardiomyopathy to evaluate if a clinical prediction rule based on ECG, brain natriuretic peptide (BNP) levels, and other biomarkers can be useful in clinical practice. This paper outlines the study and baseline characteristics of the participants.ParticipantsThe study is being conducted in 21 municipalities of the northern part of Minas Gerais State in Brazil, and includes a follow-up of 2 years. The baseline evaluation included collection of sociodemographic information, social determinants of health, health-related behaviours, comorbidities, medicines in use, history of previous treatment for Chagas disease, functional class, quality of life, blood sample collection, and ECG. Patients were mostly female, aged 50-74 years, with low family income and educational level, with known Chagas disease for >10 years; 46% presented with functional class >II. Previous use of benznidazole was reported by 25.2% and permanent use of pacemaker by 6.2%. Almost half of the patients presented with high blood cholesterol and hypertension, and one-third of them had diabetes mellitus. N-terminal of the prohormone BNP (NT-ProBNP) level was >300 pg/mL in 30% of the sample.Findings to dateClinical and laboratory markers predictive of severe and progressive Chagas disease were identified as high NT-ProBNP levels, as well as symptoms of advanced heart failure. These results confirm the important residual morbidity of Chagas disease in the remote areas, thus supporting political decisions that should prioritise in addition to epidemiological surveillance the medical treatment of chronic Chagas cardiomyopathy in the coming years. The São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) represents a major challenge for focused research in neglected diseases, with knowledge that can be applied in primary healthcare.Future plansWe will continue following this patients' cohort to provide relevant information about the development and progression of Chagas disease in remotes areas, with social and economic inequalities.Trial registration numberNCT02646943; Pre-results
Quality of life in patients with Chagas disease and the instrument used: an integrative review
Chagas disease (CD) is a neglected tropical highly morbid disease that can have a negative impact on the quality of life (QoL). The purpose of this study was to conduct an integrative review to analyze the QoL of patients with CD in the chronic phase of the disease, as well as the instruments used and the effect of different interventions. The review was carried out based on the criteria and recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guideline (PRISMA) using the PubMed, Scopus, Web of Science and Science Direct databases. An analysis of the reference list of the included articles was also carried out. Publications in all languages have been included. Two independent reviewers selected the eligible articles and extracted the data. A total of 1,479 articles were identified, and after applying the inclusion criteria 18 articles were included. Four different instruments were used to assess QoL and the most used was the Minnesota Living with Heart Failure Questionnaire (MLWHFQ) [33.3% (n = 6)]. Investigations involving intervention showed a positive impact on the patients’ QoL, and the Environment domain had the lowest score. Heterogeneity of instruments and lack of methodology standardization for assessing QoL was observed. QoL proved to be an important indicator for the planning and monitoring of patients with CD, however it is suggested that the instruments for its assessment should be the ones recommended by the validation studies. This process will allow the comparison of data between investigations
IDENTIFICAÇÃO DE ÁREAS DE EXPOSIÇÃO AO RISCO DE CONTAMINAÇÃO DE ÁGUAS SUBTERRÂNEAS PELOS HERBICIDAS ATRAZINA, DIURON E TEBUTIURON
O objetivo deste trabalho foi elaborar mapas
identificando áreas de maior exposição ao risco de
contaminação das águas subterrâneas da
Microbacia do Córrego Espraiado, em Ribeirão Preto
- São Paulo Brasil (área de recarga do Aqüífero
Guarani), utilizando o simulador CMLS-94 e o Sistema
de Informações Geográficas IDRISI. A área de estudo
conta com intensa atividade de monocultivo de canade-
açúcar, exigindo constantes aplicações de
herbicidas. Foram realizadas simulações para o
período de quatro anos, no intuito de analisar a
movimentação vertical dos herbicidas Atrazina,
Diuron e Tebutiuron e a conseqüente tendência futura
de risco de contaminação da água subterrânea local.
Foram simulados cenários para cada herbicida, nas
respectivas dosagens máximas aplicadas na região
(pior caso), em LATOSSOLO VERMELHO Eutroférrico,
LATOSSOLO VERMELHO Distrófico e NEOSSOLO
QUARTZARÊNICO. Os dados obtidos pelas
simulações foram posteriormente cruzados com os
de uso das terras, de níveis de profundidades dos
lençóis subterrâneos e dos solos na área da
Microbacia, previamente digitalizados no IDRISI. O
cruzamento das informações possibilitou a geração
de mapas de exposição do local ao risco de
contaminação da água subterrânea pelos herbicidas
estudados. O resultado da avaliação indicou que
cerca de 5,6% da área de estudo apresenta alta
exposição ao risco de contaminação de água subterrânea para Atrazina, 3,9 % para Diuron, e 13,1%
para Tebutiuron. Entretanto, não foi constatado
indicativo de concentrações de risco para a saúde
humana nos cenários analisados.
IDENTIFICATION OF EXPOSURE AREAS TO GROUNDWATER CONTAMINATION RISK BY THE HERBICIDES
ATRAZINE, DIURON AND TEBUTHIURON
Abstract
The main objective of this work was to developed maps to identify the exposure risk potential for groundwater contamination
caused by herbicides applied in the Espraiado watershed, in Ribeirão Preto/SPBrazil (recharge area of Guarani Aquifer)
using the CMLS-94 simulator and the Geographical Information System - IDRISI. The studied area has an intensive activity
of sugarcane, demanding constant herbicide applications. Simulations were accomplished for a period of four years, in
order to analyze the vertical movement of the Atrazine, Diuron and Tebuthiuron herbicides and the consequent future
tendency to the local groundwater contamination risks. The simulation scenarios for each herbicide was done at the
respective maximum rates applied in the area (worst case) in Clayey Eutroferric Red Latosol (LVef), Psamitic Distrofic Red Latosol (LVd) and Quartzarenic Neosol (RQ). The data reached by the simulations were correlated with those of depths
of groundwater levels, land use, and soil types, previously digitalized in IDRISI. The correlation of the information enabled
the generation of local exposure maps to ground water contamination risk by the studied herbicides. The evaluation of the
results indicated that almost 5.6% of the studied area has exposing risk potential of groundwater contamination by
Atrazine, 3.9% by Diuron and 13.1% by Tebuthiuron. However, it was identified that there are no final concentrations
significant for effect of human healthy risk, in the analyzed scenarios
METODOLOGIA ANALÍTICA DE RESÍDUO DO HERBICIDA 2,4-D (ÁCIDO 2,4-DICLOROFENOXIACÉTICO) EM AMOSTRAS DE ÁGUA EM ÁREA DE CULTIVO DE CANA-DE-AÇÚCAR
Desenvolveu-se método de análise de resíduo do herbicida
2,4-D para amostras de água coletadas na microbacia do
Córrego do Espraiado no período de 1996 a 1999. A
avaliação da tendência do produto alcançar camadas mais
profundas do solo foi efetuada por simulação de sistemas
(CMLS-94-Chemical Movement in Layered Soils) para
melhor entendimento do comportamento do herbicida. O
método analítico, utilizando cromatografia a gás, permitiu
correlação de 99,9% entre a área dos picos e a
concentração existente, indicando alta eficiência. Não foi
encontrado resíduo de 2,4-D na água coletada nos anos
de 1996 a 1999, o que também reforça os dados
encontrados por simulação. Esses indicaram que 60 cm foi
a profundidade máxima atingida no período de três anos,
tanto para o Latossolo Roxo quanto para o Latossolo
Vermelho Escuro. O mesmo estudo evidenciou que a partir
do segundo ano após a aplicação já não havia mais resíduos
do produto em ambos os solos estudados.
ANALYTICAL METHODOLOGY OF 2,4-D (2,4-DICHLOROPHENOXYACETIC
ACID) HERBICIDE RESIDUES IN SAMPLES OF WATER IN A SUGAR-CANE
CULTIVATION AREA IN BRAZIL
Abstract
A method of analysis of the herbicide 2,4-D was developed for water samples collected
in the Espraiado watershed in the period of 1996 and 1999. The evaluation of the
tendency of the product to reach deeper layers of the soil was made by systems
simulation (CMLS-94-Chemical Movement in Layered Soils) for better understanding
of the herbicide behavior. The gas chromatography analytical method resulted in a
99.9% correlation of the peaks area in the graphics and the herbicide concentration,
and indicated that it was highly effective. No residue of 2,4-D was detected in water
in the years of 1996 to 1999, which also reinforce the data obtained by simulation. This
indicated the leaching down to 60 cm., reached in a three-year period, in both types of
soils, Latossolo Roxo and Latossolo Vermelho-Escuro The same study evidenced
that from the second year after application there were no more product residues in
both types of the soils studied
Evaluation of the properties of WHODAS-12 measurements in individuals with Chagas disease in Brazil
Numerous tests employed to predict cardiac and functional status are expensive and not widely accessible for a considerable number of patients, particularly those diagnosed with Chagas disease (CD) residing in remote and endemic regions. To date, there is no knowledge of studies that have validated instruments that address functionality in an expanded way, including the biopsychosocial factors in patients with CD. This study aims to evaluate the psychometric properties of the World Health Organization Disability Assessment Schedule (WHODAS 2.0), in its 12-item shortened version (WHODAS-12) when applied to patients with CD. This is a cross-sectional study of a prospective cohort that follows individuals with CD (SaMi-Trop). Data collection took place between October 2019 and March 2020. In the interviews, sociodemographic information, life habits, clinical information, and indicators of disability measured by WHODAS-12 were collected. Descriptive analysis, internal consistency and construct validity of the instrument were performed. A total of 628 patients with CD were interviewed, most were women (69.5%), their mean age was of 57 years, and most declared an average self-perception of health (43.4%). The 12 items of WHODAS-12 were distributed into three factors, which together account for 61% of the variance. The Kaiser–Meyer–Olkin (KMO) index was 0.90, indicating adequacy of the sample for factor analysis. The internal consistency of the global scale showed alpha = 0.87. The percentage of incapacity was 16.05%, indicating mild incapacity for the evaluated patients. WHODAS-12 is a valid and reliable measure to assess the disability of the Brazilian population with CD
Lack of evidence of seronegative infection in an endemic area of Chagas disease
The diagnosis of Chagas disease is based on the detection of Trypanosoma cruzi (T. cruzi)-specific antibodies. Nonetheless, there is concern about the sensitivity of current serological assays due to reports of T. cruzi PCR positivity among seronegative individuals. The aim of this study was to evaluate if T. cruzi seronegative infections occur in endemic areas. We recruited 2,157 individuals that were identified as having Chagas disease in a public health system database of an endemic region in Brazil. All participants were interviewed and 2,091 had a sample collected for serological and PCR testing. From these, 149 (7.1%) had negative serological results. PCR was positive in 610 samples (31.4%) of the 1,942 seropositive samples but in none of the 149 samples from seronegative participants. True T. cruzi seronegative infections seem to be rare (95% CI 0-3.7) and should not be a concern for blood supply, which relies on antibody screening
Serological screening for Chagas disease in an endemic region of Northern Minas Gerais, Brazil: the SaMi-Trop project
Chagas disease (CD) is still a neglected disease. Infected individuals are diagnosed late, being treated in worse clinical conditions. Thus, this study aimed to analyze the prevalence and the factors associated with new confirmed cases of CD identified by serological screening in an endemic region of Minas Gerais State, Brazil. This is an analytical cross-sectional study with data from a project of the Research Center in Tropical Medicine of Sao Paulo- Minas Gerais (SaMi-Trop) conducted in two municipalities. Data collection included a questionnaire with closed questions, a venous blood collection and an ELISA serological test for CD. A total of 2,038 individuals with no previous diagnosis of CD participated in the study. The result of the serological test for CD was adopted as the dependent variable. The independent variables addressed personal issues, health conditions and lifetime housing. A descriptive analysis of individual variables was performed. Subsequently, a bivariate analysis was performed using the Pearson’s chi-square test. Households sheltering individuals positive for CD were georeferenced, and the analysis of spatial distribution was performed using the quartic function to estimate the density of the nucleus. Among the participants, 188 (9.2 %) were positive for CD. The profile of participants with CD was associated with place of residence, age, relative/family member with CD and living conditions. It is noteworthy that there are still patients with CD who are unaware of their diagnosis in both, rural and urban areas
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