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1.
Artigo em Inglês | MEDLINE | ID: mdl-33805646

RESUMO

Customers in Taiwan prefer to purchase fresh foods and household supplies at indoor traditional wet markets (TWMs). The health risk to indoor TWM staff exposed to bioaerosols needs to be evaluated, since these workers spend long periods of time in the market for stall preparation, selling, and stall cleaning. This study investigated the bioaerosols present in two indoor TWMs. The results showed that the cleaning process at Market A after operations, involving the use of an agitated waterspout, was able to decrease the concentration of bacterial bioaerosols (BBs) by an average of 64%, while at the same time increasing the concentration of fungal bioaerosols (FBs) by about 2.4 fold. The chemical sanitization process at Market B after operations was able to bring about average decreases of 30.8% in BBs and 19.2% in FBs, but the endotoxin concentration increased. Hotspots were found to be associated with vendors of fresh, live poultry and fresh, raw meat/seafood. Pseudomonas spp. and Clostridiumperfringens, both of which can be pathogenic, were found to be the dominant species present in these markets, making up 35.18% to 48.74% and 9.64% to 11.72% of the bacteria present, respectively. Our results provide fundamental information on the distributions of bioaerosols and endotoxins within indoor TWMs both before and after operation.


Assuntos
Poluição do Ar em Ambientes Fechados , Endotoxinas , Aerossóis/análise , Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Animais , Bactérias , Endotoxinas/análise , Fungos , Humanos , Taiwan
2.
Food Chem ; 335: 127627, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738534

RESUMO

A colloidal gold immunochromatographic strip (ICS) for simultaneous detection of multiple transgenic proteins, including CP4 EPSPS, BT-Cry1Ab and BT-Cry1Ac, was developed in this study. The sensitivity of the strip to the target protein was 5 ng/mL for CP4 EPSPS, 100 ng/mL for BT-Cry1Ab and Cry1Ac, respectively. Parallel analysis for maize, soybean, sugar beet and cotton showed the strip could detect 1% of transgenic content in crops containing BT-Cry1Ab and Cry1Ac, and, at least, 0.1% of content in crops containing CP4 EPSPS. The detection results for seed samples indicated the multicomponent analysis ICS had good accuracy. The analysis could be completed within 10 min and had the advantages of being high-throughput, easy to operate and visual detection. This is the first report of semi-quantitative ICS for detecting three transgenic proteins simultaneously. The developed approach may provide insights into the development of ICS for analyzing simultaneously multiple components in genetically modified crops.


Assuntos
Proteínas de Bactérias/análise , Produtos Agrícolas/genética , Endotoxinas/análise , Proteínas Hemolisinas/análise , Imunoensaio/instrumentação , Plantas Geneticamente Modificadas , Animais , Coloide de Ouro/química , Fitas Reagentes , Fatores de Tempo
3.
Ecotoxicol Environ Saf ; 205: 111365, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32977286

RESUMO

Work in wastewater treatment plants (WWTPs) can be associated with respiratory symptoms and diarrhea. The aim of this study was to obtain knowledge about WWTP workers' exposure to airborne bacteria and endotoxin, and the inflammatory potential (TIP) of their exposure, and to evaluate the risk posed by the exposure by 1) calculating a hazard index and relating the exposure to suggested occupational exposure limits (OELs), 2) estimating the potential deposition of bacteria in the airways, 3) relating it to the risk group classification of bacteria by the European Union, and 4) estimating the TIP of the personal exposure. A cohort of 14 workers were followed over one year. Bioaerosols were collected using personal and stationary samplers in a grid chamber house and an aeration tank area. Airborne bacteria were identified using (MALDI-TOF MS), and TIP of exposure was measured using HL-60 cells. A significant effect of season, work task, and person was found on the personal exposure. A hazard index based on exposure levels indicates that the risk caused by inhalation is low. In relation to suggested OELs, 14% and 34% of the personal exposure were exceeded for endotoxin (≥50 EU/m3) and bacteria (≥500 CFU/m3). At least 70% of the airborne bacteria in the grid chamber house and the aeration tank area could potentially deposit in the lower respiratory tract. From the personal samples, three of 131 bacterial species, Enterobacter cloacae, Staphylococcus aureus, and Yersinia enterocolitica are classified within Risk Group 2. Seven additional bacteria from the stationary samples belong to Risk Group 2. The bacterial species composition was affected significantly by season (p = 0.014) and by sampling type/area (p = 0.001). The TIP of WWTP workers' exposure was higher than of a reference sample, and the highest TIP was measured in autumn. TIP of personal exposure correlated with bacterial exposure. Based on the geometric average exposures to endotoxin (9.2 EU/m3) and bacteria (299 CFU/m3) and based on the calculated hazard index, the risk associated with exposure is low. However, since 43 of 106 exposure levels exceed suggested OELs, the TIP of exposure was elevated and associated with bacterial exposure, and WWTP workers were exposed to pathogenic bacteria, a continued focus on preventive measures is important. The identification of bacteria to species level in personal samples was necessary in the risk assessment, and measurement of the microbial composition made the source tracking possible.


Assuntos
Poluentes Ocupacionais do Ar/análise , Exposição Ocupacional/análise , Instalações de Eliminação de Resíduos , Eliminação de Resíduos Líquidos , Microbiologia do Ar , Bactérias , Endotoxinas/análise , Monitoramento Ambiental/métodos , Humanos , Exposição por Inalação/análise , Exposição Ocupacional/estatística & dados numéricos , Estações do Ano , Águas Residuárias/microbiologia
4.
Ecotoxicol Environ Saf ; 202: 110907, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800242

RESUMO

The impact of bioaerosols in municipal solid waste management is nowadays identified as a growing health concern worldwide. In this study, exposure to endotoxin in composting facilities and its association with lung function and clinical symptoms was investigated in Tehran municipal solid waste management complex (Aradkooh) as one of the largest solid waste management facilities in the Middle East. Airborne endotoxins were collected between June and July 2019 and the concentrations were determined by Limulus Amebocyte Lysate (LAL) method. Healthy workers with no history of respiratory disease were recruited and data on clinical symptoms (cough, phlegm, wheezing, dyspnea, fatigue, headache, eye irritation, runny nose, runny eyes, and sore throat) was obtained by the modified American Thoracic Society questionnaire, and spirometric measurement was performed by an expert. The binary logistic regression test was used and adjusted for confounding variables. The results didn't show any difference in lung function parameters (FEV1, FVC, FEV1/FVC, PEF, FEF25-75%), and most of the respiratory symptoms despite a relatively high difference in the concentration of endotoxin observed in air samples of different locations. Only the increased risk of cough (OR 10.5, 95% CI: 2.4 to 44.8 in the moderately exposed group and 7.8, 95% CI: 1.6 to 39.1 in highly exposed ones), fatigue (OR 3.7, 95% CI: 1.2 to 11.7), and headache (OR 6.02, 95% CI: 1.4 to 24.5) were found in the exposed groups compared to controls after adjusting for age, active and passive smoking. However, findings of the study might be underestimated due to some issues including healthy worker effect, intra and intersubject variability, and self-reporting bias, thereby the results should be interpreted with caution. Although we did not find any relationship, due to the high concentrations of endotoxins observed in some sites, it is recommended to consider some possible prevention measures such as using personal protective equipment to reduce the exposure of workers at an acceptable level.


Assuntos
Poluentes Ocupacionais do Ar/análise , Compostagem , Endotoxinas/análise , Exposição Ocupacional/estatística & dados numéricos , Doenças Respiratórias/epidemiologia , Adulto , Microbiologia do Ar , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Testes de Função Respiratória/efeitos adversos , Sons Respiratórios , Doenças Respiratórias/etiologia , Poluição por Fumaça de Tabaco
5.
Ecotoxicol Environ Saf ; 200: 110719, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32460046

RESUMO

The insecticidal crystal proteins of Cry2A family from Bacillus thuringiensis (Bt) are important candidate proteins expressed in gene pyramiding Bt crops. A transgenic rice line (T2A-1) harboring a synthetic Cry2A* (Cry2Aa) gene showed effective resistance to some lepidopteran rice pests. As a generalist predator in rice ecosystems, the rove beetle (Paederus fuscipes) can prey on many rice insect pests such as planthoppers. Considering the possible exposure of Cry2Aa to P. fuscipes through tritrophic food chain, it is necessary to assess the potential risks of T2A-1 rice to this predator. In this study, a tritrophic experiment was conducted to assess the prey-mediated effects of Cry2Aa on P. fuscipes through the T2A-1 rice-Nilaparvata lugens-P. fuscipes food chain. After preying on N. lugens nymphs reared on T2A-1, no accumulated Cry2Aa could be detected in P. fuscipes adults, despite Cry2Aa being detected in N. lugens. In addition, no harmful effects were detected on the life table parameters of P. fuscipes in this tritrophic chain. Additionally, direct exposure to a high dose of purified Cry2Aa protein, representing the worst case scenario, showed no significant adverse effects on the development of P. fuscipes. These results showed that transgenic Cry2Aa rice had no harmful effects on P. fuscipes.


Assuntos
Proteínas de Bactérias/genética , Besouros , Endotoxinas/genética , Proteínas Hemolisinas/genética , Oryza/genética , Plantas Geneticamente Modificadas/efeitos adversos , Animais , Proteínas de Bactérias/análise , Besouros/química , Produtos Agrícolas/genética , Endotoxinas/análise , Cadeia Alimentar , Hemípteros/química , Hemípteros/crescimento & desenvolvimento , Proteínas Hemolisinas/análise , Ninfa/química
6.
Arch Environ Occup Health ; 75(7): 415-421, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32308145

RESUMO

The aim of this study was to determine personal exposure to inhalable dust and endotoxin levels among workers in an integrated cotton-processing textile factory and exposure variability across the different work sections. Full shift measurements were carried out using inhalable conical samplers with 37 mm glass-fiber filters. Personal inhalable dust was determined gravimetrically, and endotoxin levels were analyzed by kinetic chromogenic Limulus Amebocytes Lysate assay. The geometric means of personal dust and endotoxin concentrations were 0.75 mg·m-3 and 831 EU·m-3, respectively. The highest dust and endotoxin concentrations were observed in carding section (1.34 mg·m-3 and 6,381 EU·m-3, respectively). Altogether, 11% of dust and 89% of endotoxin samples exceeded workplace exposure limits. This study showed a moderate correlation between inhalable dust and endotoxin (r = 0.450, p < 0.001). Our findings indicate that low dust exposure does not guarantee a low exposure to endotoxin.


Assuntos
Poluentes Ocupacionais do Ar/análise , Poeira/análise , Endotoxinas/análise , Exposição por Inalação/análise , Exposição Ocupacional/análise , Têxteis , Adulto , Fibra de Algodão , Monitoramento Ambiental , Etiópia , Feminino , Humanos , Masculino
7.
Occup Environ Med ; 77(6): 386-392, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32132182

RESUMO

OBJECTIVES: Four machine manufacturing facility workers had a novel occupational lung disease of uncertain aetiology characterised by lymphocytic bronchiolitis, alveolar ductitis and emphysema (BADE). We aimed to evaluate current workers' respiratory health in relation to job category and relative exposure to endotoxin, which is aerosolised from in-use metalworking fluid. METHODS: We offered a questionnaire and spirometry at baseline and 3.5 year follow-up. Endotoxin exposures were quantified for 16 production and non-production job groups. Forced expiratory volume in one second (FEV1) decline ≥10% was considered excessive. We examined SMRs compared with US adults, adjusted prevalence ratios (aPRs) for health outcomes by endotoxin exposure tertiles and predictors of excessive FEV1 decline. RESULTS: Among 388 (89%) baseline participants, SMRs were elevated for wheeze (2.5 (95% CI 2.1 to 3.0)), but not obstruction (0.5 (95% CI 0.3 to 1.1)). Mean endotoxin exposures (range: 0.09-28.4 EU/m3) were highest for machine shop jobs. Higher exposure was associated with exertional dyspnea (aPR=2.8 (95% CI 1.4 to 5.7)), but not lung function. Of 250 (64%) follow-up participants, 11 (4%) had excessive FEV1 decline (range: 403-2074 mL); 10 worked in production. Wheeze (aPR=3.6 (95% CI 1.1 to 12.1)) and medium (1.3-7.5 EU/m3) endotoxin exposure (aPR=10.5 (95% CI 1.3 to 83.1)) at baseline were associated with excessive decline. One production worker with excessive decline had BADE on subsequent lung biopsy. CONCLUSIONS: Lung function loss and BADE were associated with production work. Relationships with relative endotoxin exposure indicate work-related adverse respiratory health outcomes beyond the sentinel disease cluster, including an incident BADE case. Until causative factors and effective preventive strategies for BADE are determined, exposure minimisation and medical surveillance of affected workforces are recommended.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Bronquiolite/epidemiologia , Enfisema/epidemiologia , Endotoxinas/efeitos adversos , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Adulto , Idoso , Poluentes Ocupacionais do Ar/análise , Bronquiolite/induzido quimicamente , Enfisema/induzido quimicamente , Endotoxinas/análise , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Instalações Industriais e de Manufatura , Pessoa de Meia-Idade , National Institute for Occupational Safety and Health, U.S. , Doenças Profissionais/induzido quimicamente , Exposição Ocupacional/análise , Alvéolos Pulmonares/patologia , Inquéritos e Questionários , Estados Unidos
8.
J Biotechnol ; 312: 23-34, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32114153

RESUMO

E. coli is an attractive host organism for strong recombinant protein expression. It expresses products either as soluble protein or as inclusion bodies (IB). IBs are insoluble, mostly inactive aggregates. However, recent progress enabled the efficient refolding back into their bioactive structure. Targeted IB production processes have been designed based on their characteristic features such as high yields along with purity and their simple separation. More profound process knowledge is needed to reveal interacting parameters required for quality by design grounded process development. This enables strategies for simplifying and accelerating upstream as well as downstream procedures. We present a workflow for gathering deeper process knowledge by a design of experiment approach for improved IGF1 IB formation in relation to impurity concentration. An IB expression maximum of 19.8 mgIGF1·gDCW-1 was found at pH 6.5, 37 °C and an IPTG induction of >45 µmol gDCW-1 for 12 h. Subsequently, three refolding buffers were tested together with a nonwoven anion exchange adsorber filter module. Knowledge-based buffer selection enabled high impurity log reduction values (LRVEndotoxin = 4.9; LRVDNA = 4.8, LRVHCP = 0.1-1) as well as chromatography column guarding potential by using those adsorptive matrices. Furthermore, adsorptive filtration followed by tangential flow filtration proved to be a promising alternative for product concentration.


Assuntos
Escherichia coli/metabolismo , Corpos de Inclusão/metabolismo , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/isolamento & purificação , Proteínas Recombinantes/metabolismo , Adsorção , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Fenômenos Químicos , Cromatografia , Endotoxinas/análise , Escherichia coli/genética , Filtração/métodos , Regulação Bacteriana da Expressão Gênica , Concentração de Íons de Hidrogênio , Fator de Crescimento Insulin-Like I/genética , Tamanho da Partícula , Dobramento de Proteína , Proteínas Recombinantes/genética , Solubilidade , Temperatura , Fatores de Tempo
9.
Environ Sci Pollut Res Int ; 27(16): 19502-19509, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32212084

RESUMO

To evaluate the association between the presence of asthma and allergy, and airborne endotoxin in homes of school-age children in Kaohsiung City, Taiwan, with a case-control study design by matching the age and class exposure. Data collection of home visits included an interviewer-administered questionnaire and air sampling of participants' homes for endotoxin, bacteria, and fungi, as well as temperature and relative humidity measurements. Endotoxin was detected in all air samples with a median value of 0.67 EU m-3. In the adjusted logistic regression model, household airborne endotoxin was associated with higher prevalence of asthma and allergy; OR = 4.88 (95% CI 1.16-20.55) for Q3 (between 0.67 and 1.97 EU m -3) vs. Q1 (< 0.31 EU m -3), with statistical significance. Airborne fungi were associated with higher prevalence of asthma and allergy; OR = 4.47 (95% CI 1.13-17.69) for Q3 (between 314 and 699 CFU m -3) vs. Q1 (< 159 CFU m -3) in adjusted logistic regression models. Airborne endotoxin and fungi were significantly associated with children's asthma and allergy.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Asma , Estudos de Casos e Controles , Criança , Cidades , Endotoxinas/análise , Fungos , Humanos , Taiwan
10.
Prep Biochem Biotechnol ; 50(3): 260-271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31762381

RESUMO

Anti-leukemic enzyme L-asparaginase despite having significant applicability in medicine, holds side effects attributed to glutaminase activity and endotoxin content. Glutaminase activity proves to be toxic to non-tumor cells as glutamine is an essential amino acid. Endotoxin illicit the production of vasoactive amines and induce septic shock. Hence there is a need for glutaminase free L-asparaginase with minimum endotoxin level. The report aims at the development of a downstream process for purification of glutaminase free L-asparaginase and subsequent endotoxin removal. Producing bacteria were isolated from various soil samples and screened initially for asparaginase and glutaminase activity. The glutaminase free L-asparaginase producing bacteria were identified as Bacillus altitudinis. Production of L-asparaginase was optimized. The optimum medium comprised of comprising Lactose (1.5 g/L), NaCl (1.2 g/L), Yeast extract (5 g/L), L-asparagine (20 g/L) with pH 7.0 and incubation time of 18 h. Kinetic parameters Km and Vmax were computed to be 9.09x10-2M and 0.09 M/S. L-asparaginase Purification was achieved with a specific activity of 800 U/mg of enzyme. Molecular weight of the purified L-asparaginase was determined to be around 35 KDa using SDS-PAGE. The developed process also brought down the endotoxin content below the FDA recommended level. The endotoxin content of the purified enzyme was determined to be 0.015EU/mL.


Assuntos
Antineoplásicos , Asparaginase , Bacillus/enzimologia , Endotoxinas/análise , Microbiologia do Solo , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Asparaginase/química , Asparaginase/isolamento & purificação
11.
Indoor Air ; 30(1): 88-97, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31605641

RESUMO

Endotoxin exacerbates asthma. We designed the Louisa Environmental Intervention Project (LEIP) and assessed its effectiveness in reducing household endotoxin and improving asthma symptoms in rural Iowa children. Asthmatic school children (N = 104 from 89 homes) of Louisa and Keokuk counties in Iowa (aged 5-14 years) were recruited and block-randomized to receive extensive (education + professional cleaning) or educational interventions. Environmental sampling collection and respiratory survey administration were done at baseline and during three follow-up visits. Mixed-model analyses were used to assess the effect of the intervention on endotoxin levels and asthma symptoms in the main analysis and of endotoxin reduction on asthma symptoms in exploratory analysis. In the extensive intervention group, dust endotoxin load was significantly reduced in post-intervention visits. The extensive compared with the educational intervention was associated with significantly decreased dust endotoxin load in farm homes and less frequent nighttime asthma symptoms. In exploratory analysis, dust endotoxin load reduction from baseline was associated with lower total asthma symptoms score (Odds ratio: 0.52, 95% confidence interval: 0.29-0.92). In conclusion, the LEIP intervention reduced household dust endotoxin and improved asthma symptoms. However, endotoxin reductions were not sustained post-intervention by residents.


Assuntos
Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Asma/epidemiologia , Endotoxinas/análise , Exposição Ambiental/estatística & dados numéricos , Adolescente , Poluição do Ar em Ambientes Fechados/prevenção & controle , Asma/prevenção & controle , Criança , Pré-Escolar , Descontaminação/métodos , Exposição Ambiental/prevenção & controle , Feminino , Humanos , Iowa/epidemiologia , Masculino , População Rural/estatística & dados numéricos
12.
Artigo em Inglês | MEDLINE | ID: mdl-31783533

RESUMO

Background: Little is known about occupational exposures that occur along fecal sludge collection and resource recovery processes. This study characterizes inhaled endotoxin exposure to workers of a municipal scale fecal sludge-to-fuel processes in Kigali, Rwanda. Methods: Forty-two task-based air samples were collected from workers in five tasks along the fecal sludge collection and resource recovery process. Samples were processed for endotoxin using the limulus amebocyte lysate (LAL) test. To account for exposure variability and compare measured concentrations to established exposure limits, we used Monte Carlo modeling methods to construct distributions representing full eight-hour (8-h) exposures to endotoxin across eight exposure scenarios. Results: Geometric mean (GM) endotoxin concentrations in task-based samples ranged from 11-3700 EU/m3 with exposure concentrations increasing as the dryness of the fecal sludge increased through processing. The thermal dryer task had the highest endotoxin concentrations (GM = 3700 EU/m3) and the inlet task had the lowest (GM = 11 EU/m3). The geometric means (GM) of modeled 8-h exposure concentrations were between 6.7-960 EU/m3 and highest for scenarios which included the thermal dryer task in the exposure scenario. Conclusions: Our data suggest the importance of including worker exposure considerations in the design of nascent fecal sludge management processes. The methods used in this study combine workplace sampling with stochastic modeling and are useful for exposure assessment in resource constrained contexts.


Assuntos
Poluentes Ocupacionais do Ar/análise , Endotoxinas/análise , Exposição Ocupacional/análise , Esgotos , Inquéritos Epidemiológicos , Humanos , Exposição por Inalação , Ruanda
13.
Int J Tuberc Lung Dis ; 23(11): 1171-1177, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31718753

RESUMO

OBJECTIVE: To examine the associations between endotoxin and (1,3)-ß-glucan concentrations in office dust and respiratory symptoms and airway inflammation among 695 office workers in Malaysia.METHODS: Health data were collected using a questionnaire, sensitisation testing and measurement of fractional exhaled nitric oxide (FeNO). Indoor temperature, relative air humidity (RH) and carbon dioxide (CO2) were measured in the offices and settled dust was vacuumed and analysed for endotoxin and (1,3)-ß-glucan concentrations. Associations were analysed by two level multiple logistic regression.RESULTS: Overall, 9.6% of the workers had doctor-diagnosed asthma, 15.5% had wheeze, 18.4% had daytime attacks of breathlessness and 25.8% had elevated FeNO (≥25 ppb). The median levels in office dust were 11.3 EU/mg endotoxin and 62.9 ng/g (1,3)-ß-glucan. After adjusting for personal and home environment factors, endotoxin concentration in dust was associated with wheeze (P = 0.02) and rhinoconjunctivitis (P = 0.007). The amount of surface dust (P = 0.04) and (1,3)-ß-glucan concentration dust (P = 0.03) were associated with elevated FeNO.CONCLUSION: Endotoxin in office dust could be a risk factor for wheeze and rhinoconjunctivitis among office workers in mechanically ventilated offices in a tropical country. The amount of dust and (1,3)-ß-glucan (a marker of indoor mould exposure) were associated with Th2 driven airway inflammation.


Assuntos
Asma/epidemiologia , Poeira/análise , Dispneia/epidemiologia , Endotoxinas/análise , Rinite/epidemiologia , beta-Glucanas/análise , Adulto , Poluição do Ar em Ambientes Fechados/análise , Dióxido de Carbono/análise , Feminino , Humanos , Umidade , Modelos Logísticos , Malásia/epidemiologia , Masculino , Óxido Nítrico/análise , Sons Respiratórios/etiologia , Temperatura , Clima Tropical , Local de Trabalho
14.
Sci Rep ; 9(1): 16117, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31695115

RESUMO

The wide cultivation of genetically modified (GM) insect-resistant crops has raised concerns on the risks to the eco-environment resulting from a release of Cry proteins. Therefore, it is vital to develop a method for the quantification of GM crops. Herein, A highly sensitive immunosensing platform has been developed for both colorimetric and chemiluminescent (CL) detection of Cry 1Ab using dual-functionalized gold nanoparticles (AuNPs) as signal amplification nanoprobes for the first time. In this work, anti-Cry 1Ab monoclonal antibody and horseradish peroxidase (HRP) are simultaneously functionalized on the surface of AuNPs with an exceptionally simple synthesis method. Combined with immunomagnetic separation, this immunosensing platform based on colorimetric method could detect Cry 1Ab in one step in a linear range from 1.0 to 40 ng mL-1 within 1.5 h, with a limit of detection of 0.50 ng mL-1. The sensitivity of fabricated nanoprobes was 15.3 times higher than that using commercial HRP-conjugated antibody. Meanwhile, the fabricated nanoprobes coupled with CL detection was successfully applied for Cry 1Ab detection with a minimum detection concentration of 0.050 ng mL-1 within a linear range of 0.10-20 ng mL-1. The proposed approach was validated with genuine GM crops, and the results showed a good correlation coefficient of 0.9906 compared to those of a commercial ELISA kit. Compared with ELISA, the developed immunosensing platform significantly simplified the assay procedure and shortened the analytical time, thus providing a new platform for the detection of genetically modified crops with high sensitivity, rapidity and simplicity.


Assuntos
Colorimetria/métodos , Produtos Agrícolas/química , Imunoensaio/métodos , Medições Luminescentes/métodos , Plantas Geneticamente Modificadas/química , Proteínas de Bactérias/análise , Produtos Agrícolas/genética , Endotoxinas/análise , Ouro/química , Proteínas Hemolisinas/análise , Limite de Detecção , Nanopartículas Metálicas/química , Plantas Geneticamente Modificadas/genética
15.
Mikrochim Acta ; 186(11): 731, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31659455

RESUMO

Fluorescent polymer dots (PDs) with maximum excitation/emission wavelengths of 410/515 nm were prepared in water solution from 1,4-benzoquinone and ethylenediamine. The green fluorescence of these PDs is screened off by the red-colored oxidation product (PPDox, maximum absorption at 510 nm) formed by horseradish peroxidase (HRP)-catalyzed oxidation of p-phenylenediamine (PPD). It causes the reduction of the fluorescence intensity of the PDs due to spectral overlap and an inner filter effect (IFE). If glucose is enzymatically oxidized under the formation of H2O2, the formed H2O2 can be quantified by the above IFE. The assay for HRP activity and glucose have detection limits of 0.2 U·L-1 and 0.1 µM, respectively. The nanoprobe was further extended to an immunosorbent assay (ELISA) for the determination of insecticidal Cry1Ab/Ac protein with a detection limit of 0.25 ng·mL-1. The ELISA was applied to rice leaf analysis. Graphic abstract Schematic representation of fluorometrict enzyme-linked immunosorbent assay for Cry1Ab/Ac protein detection based on horseradish peroxidase (HRP)-triggered fluorescence quenching of polymer dots (PDs). Quenching is caused by an inner filter effect (IFE) caused by PPDox, the oxidation product of p-phenylenediamine (PPD).


Assuntos
Proteínas de Bactérias/análise , Endotoxinas/análise , Glucose/análise , Proteínas Hemolisinas/análise , Peroxidase do Rábano Silvestre/análise , Polímeros/química , Pontos Quânticos/química , Anticorpos Imobilizados/imunologia , Armoracia/enzimologia , Bacillus thuringiensis/química , Proteínas de Bactérias/imunologia , Endotoxinas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Glucose/química , Glucose Oxidase/química , Proteínas Hemolisinas/imunologia , Peróxido de Hidrogênio/química , Limite de Detecção , Oryza/química , Fenilenodiaminas/química , Plantas Geneticamente Modificadas/química , Espectrometria de Fluorescência/métodos
16.
Biol Pharm Bull ; 42(12): 2024-2037, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31588055

RESUMO

Assays using lysate reagents prepared from horseshoe crab hemocyte extract (limulus amoebocyte lysate, LAL) are commonly and widely used to detect and measure endotoxin in parenteral drugs and medical devices. However, lysate reagents suffer from lot-to-lot variations leading to possible fluctuations in testing. Also, this continued usage of lysate reagents leads to the possible decline of the horseshoe crab population. Recently, a new recombinant chromogenic reagent, PyroSmart, consisting of three recombinant factors was introduced to the market. There are now three recombinant products; two with recombinant factor C reagents and PyroSmart with the complete recombinant LAL system. We evaluated the applicability of the reagent to the harmonized bacterial endotoxins test in the United States, European and Japanese pharmacopeias. The recombinant product showed equivalent potency of thirteen endotoxins from different bacterial strains to conventional chromogenic lysate reagents as long as their assay modes are identical. All analytical characteristics or assay parameters of the reagent satisfied the acceptance criteria which are set for the use for the bacterial endotoxins test filed in the pharmacopeias. All of 109 parenteral drugs tested can be measured with PyroSmart within respective maximum allowable dilutions. The lot-to-lot variation in recovery of endotoxin added in the parenteral drugs for PyroSmart was equal to or less than those of six limulus lysate reagents. In conclusion, the present study suggests that the recombinant reagent, PyroSmart, provide a good alternative to the LAL reagents with better lot-to-lot variation.


Assuntos
Proteínas de Bactérias/análise , Endotoxinas/análise , Indicadores e Reagentes/química , Bioensaio
17.
Biol Pharm Bull ; 42(10): 1713-1719, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582659

RESUMO

Asian dust events are caused by dust storms originating from deserts in Mongolia and northern China, and these events are observed in Japan, mainly in spring. To explore the effect of Asian dust events on atmospheric endotoxin and protein levels, we collected the total suspended particles (TSP) in the spring months (March, April, and May) of 2015 in Sasebo and Kyoto, Japan, and assessed the levels of biological elements at both locations. At both locations, the daily concentrations of TSP, water-soluble Ca2+ (an indicator mineral of soil in dust), endotoxins, and proteins were found to be high during and after Asian dust events recorded by the Japan Meteorological Agency. The concentration of Ca2+ showed a strong positive correlation with the concentrations of TSP and endotoxin, while the concentration of protein was moderately positively correlated with Ca2+ in both Sasebo and Kyoto. There were large concentrations of endotoxins, and the fluctuation ranges were higher in Sasebo than in Kyoto. In contrast, protein concentrations showed low levels of fluctuation, and no major differences were found in the concentration at each location.


Assuntos
Poluentes Atmosféricos/análise , Poeira/análise , Endotoxinas/análise , Proteínas/análise , Cálcio/análise , China , Monitoramento Ambiental , Japão , Mongólia , Estações do Ano , Vento
18.
Food Funct ; 10(10): 6720-6731, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31566196

RESUMO

Decolourization of polysaccharides is one of the crucial procedures that affects their structure, which is closely related to their bioactivity. Here, Grifola frondosa polysaccharide (GFP) was decolourized with H2O2 and AB-8 macroporous resin. Then, two main fractions, named DGFP and SGFP, were obtained by purification with Sepharose CL-4B. The molecular weights of these two polysaccharides were determined to be 6.306 × 106 (±0.410%) Da and 1.174 × 107 (±0.299%) Da by HPSEC. Monosaccharide analysis indicated that DGFP was composed of glucose, mannose, and galactose (32.20 : 1.00 : 1.75), while SGFP consisted entirely of glucose. Despite a backbone →4)-α-Glcp-(1→ in two polysaccharides, reducing ends Rα →3)-α-Glcp and Rß â†’4)-ß-Glcp were observed in DGFP by 1D/2D NMR. The results suggested that decolourization with low concentrations of H2O2 might alter the structure of GFP and generate new reducing ends. In vitro antioxidant results implied that DGFP exhibited a higher ability to scavenge DPPH and hydroxyl radicals and reduced the over-generated ROS levels in a concentration-dependent manner. These results suggested that the antioxidant effects of GFP could be activated by decolourization with H2O2. Therefore, DGFP might be a more promising natural antioxidant than SGFP.


Assuntos
Antioxidantes/farmacologia , Grifola/química , Polissacarídeos/química , Sobrevivência Celular/efeitos dos fármacos , Endotoxinas/análise , Células Hep G2 , Humanos , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Espectroscopia de Ressonância Magnética , Peso Molecular , Estresse Oxidativo/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Braz Oral Res ; 33: e039, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508729

RESUMO

This clinical study compared the effectiveness of two rotary systems: HyFlex CM (Coltene-Whaledent, Altstetten, Switzerland) and ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland) on the removal of cultivable bacteria and endotoxins from primarily infected root canals. This study was designed as a randomized single-blinded, 2-arm, clinical trial. Twenty-four primarily infected root canals were selected and randomly divided into 2 groups: HyFlex CM (n = 12); and ProTaper Next (n = 12). Samples were collected before and after the biomechanical preparation and inoculated in specific flasks. Irrigation was performed using 2.5% sodium hypochlorite. A kinetic turbidimetric lysate assay of limulus amoebocytes was used to quantify endotoxins. Microbiological culture technique was used to determine the count of bacterial colony forming units (CFU/mL). Data collected were statistically analyzed using SigmaPlot 12.0 for Windows. The Two-Way ANOVA statistical test was performed and the level of significance was 5%. In the samples before the biomechanical preparation, cultivable bacteria and endotoxins were evidenced in 100% of the cases. The culture analysis revealed that there was no statistically significant difference in the bacterial reduction between the two instrumentation systems. Endotoxins were present in 100% of the canals after instrumentation and there was no statistical difference between the two systems in endotoxin reduction. Thus, it was concluded that both instrumentation systems were effective in reducing root canal bacteria and endotoxins with primary endodontic infection and that there was no statistical difference between them. However, no system was able to eliminate 100% of the bacteria and their by-products.


Assuntos
Bactérias/isolamento & purificação , Instrumentos Odontológicos , Cavidade Pulpar/microbiologia , Lipopolissacarídeos/análise , Preparo de Canal Radicular/instrumentação , Adulto , Carga Bacteriana , Técnicas Bacteriológicas , Endotoxinas/análise , Feminino , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Resultado do Tratamento
20.
Ann Work Expo Health ; 63(9): 965-974, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31504156

RESUMO

OBJECTIVES: Methanogenic archaea have been found to make up part of the bioaerosols in pig, cattle, and poultry farms. So far no attempts have been made to determine how season, farm type, and farm characteristics may affect workers' exposure to archaea. METHODS: Personal filter samples from 327 farmers working on 89 Danish farms were analysed for the number of 16S rRNA gene copies from archaea and bacteria and for their dust and endotoxin content. The farms were visited during summer and winter. Information on farm type and stable characteristics were collected using self-reported activity diaries and walk-through surveys. Differences in archaea and bacteria levels with farm type and stable characteristics and correlations with dust and endotoxin levels were examined. RESULTS: Personal archaea exposure was documented in all farm types including, for the first time, during mink farming. At 7.3*104 gene copies m-3 the archaea levels were around two orders of magnitude lower than bacteria levels at 5.7*106 gene copies m-3. At 1.7*105 gene copies m-3 among pig farmers and 1.9*104 gene copies m-3 among cattle farmers the archaea levels differed with farm type (P < 0.0005). The archaea and bacteria levels correlated weakly with a Pearson correlation coefficient of 0.17. Neither archaea nor bacteria levels differed by season. In pig farms the archaea levels differed by type of ventilation and by wetness of the floor. CONCLUSIONS: Archaea levels were not neglible and appeared to vary greatly between farm types. In pig farms they varied with some farm characteristics. Archaea levels appeared to depend on factors that differed from those of bacteria.


Assuntos
Agricultura , Poluentes Ocupacionais do Ar/análise , Criação de Animais Domésticos/estatística & dados numéricos , Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Exposição por Inalação/análise , Exposição Ocupacional/análise , Animais , Dinamarca , Poeira/análise , Endotoxinas/análise , Monitoramento Ambiental/métodos , Humanos , Gado , RNA Ribossômico 16S/análise , Ventilação
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