72 research outputs found

    Mode of Action and Synergy of Ceftazidime and Baicalein against Streptococcus pyogenes

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    Purpose: To investigate the antibacterial activity of baicalein used alone, or in combination with ceftazidime, against Streptococcus pyogenes.Methods: Minimum inhibitory concentration (MIC), checkerboard assay parameters, and viability curves were determined for S. pyogenes DMST 30653, 30654, and 30655. Cytoplasmic membrane (CM) permeability technique, enzyme assays, transmission electron microscopy and Fourier transforminfrared microspectroscopy were used to investigate the changes in the bacterial biomolecules.Results: The MIC of ceftazidime and baicalein against all the S. pyogenes strains were 0.50 and > 256.0 μg/ml, respectively. A synergistic effect against these strains was exhibited by the ceftazidime/baicalein combination (fractional inhibitory concentration index, < 0.37). The results for the viable counts indicate that this synergistic activity was present. Baicalein exerted inhibitory activity against β-lactamase. Compared with the controls, combining baicalein with ceftazidime caused peptidoglycan and morphological damage, significantly increased CM permeability and protein concentrations, and decreased cellular fatty acid and nucleic acid concentrations.Conclusion: Baicalein is a potential synergistic adjunct to ceftazidime for the treatment of S. pyogenes infections.Keywords: Streptococcus pyogenes, Cytoplasmic membrane permeability, Baicalein, Ceftazidime, Synergistic activity, Fourier Transform-infrared microspectroscopy, Transmission electron microscop

    Cadmium Contamination in Farmland Soil and Water Near Zinc Mining Site

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    This study was a cross-sectional study conducted in Phatadpadaeng Subdistrict, Mae Sod District, Tak Province, Thailand. This study aimed to determine cadmium concentration in farmland soil and water as well as at the residence of farmers and households. As many as 48 samples of farmers' residence soil and water, twelve samples of households and six samples of farmland soil and eight samples of farmland water were investigated for cadmium concentration using Graphite Furnace Atomic Absorption Spectrophotometer. The Mann-Whitney U test was used for the analysis of the difference of cadmium concentration between farmland soil and residence soil, farmland water and residence water. The results showed no statistically difference among all matrixes, however, farmland soil and farmland water showed highest concentration compared to those of resident farmers and households. The cadmium concentrations in all samples were far below the limit values. This study clearly showed that working conditions of farmers demonstrated higher level of cadmium compared to the living conditions. The cause of this contamination might be from the activities of the surroundings industry. Therefore, it would be recommended that farmers should consider for cadmium exposure while working in farm

    Effects of an injury and illness prevention program on occupational safety behaviors among rice farmers in Nakhon Nayok Province, Thailand

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    Sapsatree Santaweesuk,1,2 Robert S Chapman,1 Wattasit Siriwong1,3 1College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 2Srinakarinwirot University Ongkharak Campus, Nakhon Nayok, Thailand; 3Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, Thailand Abstract: The objective of this study was to determine the effects of an Injury and Illness Prevention (IIP) program intervention on occupational safety behavior among rice farmers in Nakhon Nayok province, Thailand. This was a quasi-experimental study in an intervention group and a control group. It was carried out in two rice farming communities, in which most people are rice farmers with similar socio-demographic characteristics. Multistage sampling was employed, selecting one person per rice farming household. The intervention group was 62 randomly selected rice farmers living in a rural area; another 55 rice farmers served as the control group. A structured face-to-face interview questionnaire was administered to participants to evaluate their safety behaviors in four areas: equipment use, pesticide use, ergonomics, and working conditions. The 2-week intervention program consisted of four elements: 1) health education, 2) safety inspection, 3) safety communication, and 4) health surveillance. Data were collected at baseline and 4 months after the intervention (follow-up). We used a general linear model repeated-measures analysis of variance to assess the mean difference between baseline and follow-up occupational safety behavior points between the intervention and control groups. Pesticide safety behaviors significantly increased in the intervention group compared with the control group. Ergonomics and working conditions points also increased in the intervention group, but not significantly so. The equipment use score decreased in the intervention group. It is necessary to identify and develop further measures to improve occupational safety behaviors. Some methods, such as effective risk communication, could be added to increase risk perception. Keywords: occupational safety behaviors, rice farmers, safety program, injury and illness prevention progra

    Assessment of efficiency of water supply system in Prince of Songkla University, Hat Yai Campus

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    Assessment of efficiency of water production system in Prince of Songkla University, Hat Yai Campus, was conducted in this study. Topics covered include 1) quality and quantity of raw water, 2) water productionprocess, 3) management and maintenance of water production system, and 4) quality of finished water. Totally, 494 water samples were collected during the study. All water samples were analyzed for turbidity,pH, temperature, conductivity, TDS, total coliforms, fecal coliforms and residual chlorine. In addition to the mentioned parameters, 30 of these water samples were also analyzed for hardness, chloride, nitratenitrogen,sulfate and heavy metals (manganese, copper, zinc, iron, chromium, cadmium, lead and mercury). All water samples were collected during November, 2004 (rainy season) and March, 2005 (summer season).It was found that the quality of the water in the Sritrang reservoir fell into Class 2 of Thailand Surface Water Quality Standard that requires ordinary water treatment processes prior to consumptions.Cadmium, lead and mercury were not detected by Inductively Coupled Plasma (ICP) method. There are 2 sets of water production system. The first set consists of 4 pressure filters which could reduce turbidity atvarying efficiencies: 33.83%, 18.26%, 42.76% and 65.67% depending mainly on the extent of chemical dosing control and the maintenance of the filter media. Another system employed sedimentation tank andrapid sand filter, which could remove turbidity at 89.28%. When combined finished water from both systems were analyzed, it was found that removals of manganese, copper, zinc, iron and chromium were 42.65%,30.02%, 19.54%, 56.82% and 15.12%, respectively. Residual chlorine concentration of the finished water was not more than 0.2 mg/L and no total coliforms or fecal coliforms were detected. The plant had sufficientand competent personnel to carry out their normal tasks but occasional negligence and lack of specific water testing or chemical dosing equipment were observed. The quality of tap water (in distribution system) isin compliance with the WHO drinking water quality standards, except occasionally turbidity and pH. Significant difference (p<0.05) in tap water quality was found between the samples collected in rainy and summer seasons

    Environmental arsenic exposure and risk of diabetes type 2 in Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand: unmatched and matched case&ndash;control studies

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    Kwanyuen Sripaoraya,1,2 Wattasit Siriwong,1 Sumol Pavittranon,2 Robert S Chapman1 1College of Public Health Sciences, Chulalongkorn University, Bangkok, 2Medical Life Sciences Institute, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand Background: There are inconsistent findings on associations between low-to-moderate level of arsenic in water and diabetes risk from previous epidemiological reports. In Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand, a low level of arsenic exposure among population was observed and increased diabetes mellitus (DM) rate was identified.Objectives: We aimed to investigate the association between determinants (including low-level water arsenic exposure) of DM type 2 risk among residents of three villages of Ron Phibun subdistrict, Nakhon Si Thammarat Province.Materials and methods: Secondary data from two previous community based-studies, conducted in 2000 and 2008, were utilized. Data on independent variables relating to arsenic exposure and sociodemographic characteristics were taken from questionnaires and worksheets for health-risk screening. Water samples collected during household visit were sent for analysis of arsenic level at certified laboratories. Diabetes cases (N=185) were those who had been diagnosed with DM type 2. Two groups of controls, one unmatched to cases (n=200) and one pair matched on age and gender (n=200), were selected for analysis as unmatched and matched case&ndash;control studies, respectively. A multiple imputation technique was used to impute missing values of independent variables. Multivariable logistic regression models, with independent variables for arsenic exposure and sociodemographic characteristics, were constructed. The unmatched and matched data sets were analyzed using unconditional and conditional logistic analyses, respectively.Results: Older age, body mass index (BMI), having a history of illness in siblings and parents, and drinking were associated with increased DM type 2 risk. We found no convincing association between DM type 2 risk and water arsenic concentration in either study.Conclusion: We did not observe meaningful association between diabetes risk and the low-to-moderate arsenic levels observed in this study. Further research is needed to confirm this finding in the study area and elsewhere in Thailand. Keywords: diabetes, arsenic exposure, case&ndash;control, Ron Phibun subdistrict, Thailan

    Multi-approach model for improving agrochemical safety among rice farmers in Pathumthani, Thailand

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    Buppha Raksanam,1,2 Surasak Taneepanichskul,2 Wattasit Siriwong,2 Mark Robson3,41Sirindhorn College of Public Health, Trang, 2College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 3School of Environmental and Biological Sciences, Rutgers University, 4School of Public Health, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ, USAAbstract: The large-scale use of agrochemicals has raised environmental and human health concerns. A comprehensive intervention strategy for improving agrochemical safety among rice farmers in Thailand is lacking. The objective of this study is to develop a model in order to improve farmers&amp;rsquo; health and prevent them from being exposed to agrochemical hazards, in addition to evaluating the effectiveness of the intervention in terms of agrochemical safety. This study was conducted between October 2009 and January 2011. It measures changes in the mean scores of agrochemical knowledge, health beliefs, agrochemical use behaviors, and in-home pesticide safety. Knowledge of agrochemical use constitutes a basic knowledge of agrochemicals and agrochemical safety behaviors. Health beliefs constitute perceived susceptibility, severity, benefits, and barriers to using agrochemicals. Agrochemical use behaviors include self-care practices in terms of personal health at specific times including before spraying, while spraying, during storage, transportation, waste management, and health risk management. Fifty rice farmers from Khlong Seven Community (study group) and 51 rice farmers from Bueng Ka Sam community (control group) were randomly recruited with support from community leaders. The participants were involved in a combination of home visits (ie, pesticide safety assessments at home) and community participatory activities regarding agrochemical safety. This study reveals that health risk behaviors regarding agrochemical exposure in the study area are mainly caused by lack of attention to safety precautions and the use of faulty protective gear. After 6 months, the intervention program showed significant improvements in the overall scores on knowledge, beliefs, behaviors, and home pesticide safety in the study group (P &amp;lt; 0.05). Therefore, this intervention model is effective in improving agrochemical safety behaviors among Khlong Seven Community rice farmers. These findings demonstrate that a multi-approach model for improving agrochemical safety behaviors can lead to sustainable prevention of agrochemical hazards for farmers.Keywords: rice farmer, agrochemical safety, community-based intervention, mode

    An association between organophosphate pesticides exposure and Parkinsonism amongst people in an agricultural area in Ubon Ratchathani Province, Thailand

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    Background. Parkinson’s disease (PD) is a ubiquitous disease. However, PDs prevalence in the population of agricultural communities lacks understanding and there has been no epidemiological study on the association between pesticides exposure factors and risk for PD. Objective. To investigate the potential association between organophosphate pesticides exposure and Parkinsonism by using a screening questionnaire in agricultural areas. Material and Methods. Ninety elderly people living in agricultural areas participated in a cross-sectional study conducted at Tambon Hua-Rua Health Promoting Hospital in April 2014. Screening questionnaires for Parkinson’s disease, Test-mate ChE (Model 400) for blood cholinesterase (ChE) levels of both blood enzymes erythrocyte cholinesterase (AChE), and plasma cholinesterase (PChE) were used as measurement tools. Descriptive statistics for frequencies and percentage distributions were used primarily to summarize and describe the data. Sensitivity, specificity, positive and negative predictive values were calculated. Results. The age range of the participants was 50 to 59 years old, with an average age of 53.9+2.87 years. The majority of the participants were female (62.2%), 82.2% of respondents were farmers. Most of participants (76.7%) reported that they applied insecticides in their farms. Ninety persons participated and completed the 11-item questionnaire. Of these, 17 (18.9%) felt that they lost balance when turning or that they needed to take a few steps to turn right around and 16.7% of participants indicated that they felt the need to move slowly or stiffly. The study found the prevalence of abnormal AChE levels was 28.9% (95%CI=19.81-39.40) and 17.8% of PChE levels (95%CI=10.52-27.26). To predict Parkinsonism, AChE, and PChE level, with a cutoff score of 5 or higher there had to be a sensitivity of 0.31, specificity of 1.00, positive predictive value (PPV) of 1.00 and negative predictive value (NPV) of 0.78 for AChE. While PChE, the score value of 5 or more had a sensitivity of 0.19, specificity of 0.93, PPV of 0.38 and NPV of 0.84. Conclusion. This study described an association between pesticides exposure and Parkinsonism. The questionnaire appears to be useful for Thai agriculturists as a screening tool for Parkinsonism and cholinesterase levels regarding to pesticides exposure
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