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The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic–pituitary–thyroid (HPT) axis, acutely altering thyroid hormone levels.
Pornpimol Kongtip; Noppanun Nankongnab; Ritthirong Pundee; Nichcha Kallayanatham; Sumate Pengpumkiat; Jutamanee Chungcharoen; Chavisa Phommalachai; Pajaree Konthonbut; Nattagorn Choochouy; Preecha Sowanthip; Phanthawee Khangkhun; Jutharak Yimsabai; Susan Woskie. Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers. Toxics 2021, 9, 16 .
AMA StylePornpimol Kongtip, Noppanun Nankongnab, Ritthirong Pundee, Nichcha Kallayanatham, Sumate Pengpumkiat, Jutamanee Chungcharoen, Chavisa Phommalachai, Pajaree Konthonbut, Nattagorn Choochouy, Preecha Sowanthip, Phanthawee Khangkhun, Jutharak Yimsabai, Susan Woskie. Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers. Toxics. 2021; 9 (1):16.
Chicago/Turabian StylePornpimol Kongtip; Noppanun Nankongnab; Ritthirong Pundee; Nichcha Kallayanatham; Sumate Pengpumkiat; Jutamanee Chungcharoen; Chavisa Phommalachai; Pajaree Konthonbut; Nattagorn Choochouy; Preecha Sowanthip; Phanthawee Khangkhun; Jutharak Yimsabai; Susan Woskie. 2021. "Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers." Toxics 9, no. 1: 16.
A detection method for type-II pyrethroids in an environmental water sample using a microfluidic paper-based analytical device (µPAD) is reported here. The detection approach is based on the formation of cyanide from the hydrolysis of type-II pyrethroids and the colorimetric detection of cyanide on a layer-based µPAD. Parafilm and inexpensive laminating pouches were used to create a hydrophobic barrier for the assay on the µPAD. This detection approach was selective to type-II pyrethroids in water for which an environmental water sample was tested. The calibration curves for cypermethrin, deltamethrin, cyhalothrin, and fenvalerate ranged from 2 to 40 µg/mL without sample preconcentration. The lower concentrations of type-II pyrethroids can be assessed by including a preconcentration step prior to the detection on a µPAD. This detection system provides an alternative platform for fast, semiquantitative testing for pesticide contamination in environmental surface water by allowing for portability, low reagent/sample consumption, and low-cost testing.
Sumate Pengpumkiat; Jintana Nammoonnoy; Watcharaporn Wongsakoonkan; Pajaree Konthonbut; Pornpimol Kongtip. A Microfluidic Paper-Based Analytical Device for Type-II Pyrethroid Targets in an Environmental Water Sample. Sensors 2020, 20, 4107 .
AMA StyleSumate Pengpumkiat, Jintana Nammoonnoy, Watcharaporn Wongsakoonkan, Pajaree Konthonbut, Pornpimol Kongtip. A Microfluidic Paper-Based Analytical Device for Type-II Pyrethroid Targets in an Environmental Water Sample. Sensors. 2020; 20 (15):4107.
Chicago/Turabian StyleSumate Pengpumkiat; Jintana Nammoonnoy; Watcharaporn Wongsakoonkan; Pajaree Konthonbut; Pornpimol Kongtip. 2020. "A Microfluidic Paper-Based Analytical Device for Type-II Pyrethroid Targets in an Environmental Water Sample." Sensors 20, no. 15: 4107.
Sumate Pengpumkiat; Yuanyuan Wu; Saichon Sumantakul; Vincent T. Remcho. A Membrane-based Disposable Well-Plate for Cyanide Detection Incorporating a Fluorescent Chitosan-CdTe Quantum Dot. Analytical Sciences 2020, 36, 193 -199.
AMA StyleSumate Pengpumkiat, Yuanyuan Wu, Saichon Sumantakul, Vincent T. Remcho. A Membrane-based Disposable Well-Plate for Cyanide Detection Incorporating a Fluorescent Chitosan-CdTe Quantum Dot. Analytical Sciences. 2020; 36 (2):193-199.
Chicago/Turabian StyleSumate Pengpumkiat; Yuanyuan Wu; Saichon Sumantakul; Vincent T. Remcho. 2020. "A Membrane-based Disposable Well-Plate for Cyanide Detection Incorporating a Fluorescent Chitosan-CdTe Quantum Dot." Analytical Sciences 36, no. 2: 193-199.
Described is a new approach to building a microfluidic quantum dot wavelength-ratiometric sensor system for quantifying copper in water and biological samples.
Sumate Pengpumkiat; Yuanyuan Wu; Anukul Boonloed; Gayan C. Bandara; Vincent T. Remcho. A microfluidic detection system for quantitation of copper incorporating a wavelength-ratiometric fluorescent quantum dot pair. Analytical Methods 2017, 9, 1125 -1132.
AMA StyleSumate Pengpumkiat, Yuanyuan Wu, Anukul Boonloed, Gayan C. Bandara, Vincent T. Remcho. A microfluidic detection system for quantitation of copper incorporating a wavelength-ratiometric fluorescent quantum dot pair. Analytical Methods. 2017; 9 (7):1125-1132.
Chicago/Turabian StyleSumate Pengpumkiat; Yuanyuan Wu; Anukul Boonloed; Gayan C. Bandara; Vincent T. Remcho. 2017. "A microfluidic detection system for quantitation of copper incorporating a wavelength-ratiometric fluorescent quantum dot pair." Analytical Methods 9, no. 7: 1125-1132.
Non-toxic, fluorescent carbon nanodot labels are employed as novel ratiometric immunosensors for α-fetoprotein (AFP), a liver cancer biomarker. The assay generates a broad linear range, a low detection limit, and can be adapted to a variety of immunoassay targets.
Yuanyuan Wu; Peng Wei; Sumate Pengpumkiat; Emily A. Schumacher; Vincent T. Remcho. A novel ratiometric fluorescent immunoassay for human α-fetoprotein based on carbon nanodot-doped silica nanoparticles and FITC. Analytical Methods 2016, 8, 5398 -5406.
AMA StyleYuanyuan Wu, Peng Wei, Sumate Pengpumkiat, Emily A. Schumacher, Vincent T. Remcho. A novel ratiometric fluorescent immunoassay for human α-fetoprotein based on carbon nanodot-doped silica nanoparticles and FITC. Analytical Methods. 2016; 8 (27):5398-5406.
Chicago/Turabian StyleYuanyuan Wu; Peng Wei; Sumate Pengpumkiat; Emily A. Schumacher; Vincent T. Remcho. 2016. "A novel ratiometric fluorescent immunoassay for human α-fetoprotein based on carbon nanodot-doped silica nanoparticles and FITC." Analytical Methods 8, no. 27: 5398-5406.
Chemical synthesis of oligonucleotides is a widely used tool in the field of biochemistry. Several methods for gene synthesis have been introduced in the growing area of genomics. In this paper, a novel method of constructing dsDNA is proposed. Short (28-mer) oligo fragments from a library were assembled through successive annealing and ligation processes, followed by PCR. First, two oligo fragments annealed to form a dsDNA molecule. The double-stranded oligo was immobilized onto magnetic beads (solid support) via streptavidin-biotin binding. Next, single-stranded oligo fragments were added successively through ligation to form the complete DNA molecule. The synthesized DNA was amplified through PCR and gel electrophoresis was used to characterize the product. Sanger sequencing showed that more than 97% of the nucleotides matched the expected sequence. Extending the length of the DNA molecule by adding single-stranded oligonucleotides from a basis set (library) via ligation enables a more convenient and rapid mechanism for the design and synthesis of oligonucleotides on the go. Coupled with an automated dispensing system and libraries of short oligo fragments, this novel DNA synthesis method would offer an efficient and cost-effective method for producing dsDNA.
Sumate Pengpumkiat; Myra Koesdjojo; Erik R. Rowley; Todd C. Mockler; Vincent T. Remcho. Rapid Synthesis of a Long Double-Stranded Oligonucleotide from a Single-Stranded Nucleotide Using Magnetic Beads and an Oligo Library. PLOS ONE 2016, 11, e0149774 .
AMA StyleSumate Pengpumkiat, Myra Koesdjojo, Erik R. Rowley, Todd C. Mockler, Vincent T. Remcho. Rapid Synthesis of a Long Double-Stranded Oligonucleotide from a Single-Stranded Nucleotide Using Magnetic Beads and an Oligo Library. PLOS ONE. 2016; 11 (3):e0149774.
Chicago/Turabian StyleSumate Pengpumkiat; Myra Koesdjojo; Erik R. Rowley; Todd C. Mockler; Vincent T. Remcho. 2016. "Rapid Synthesis of a Long Double-Stranded Oligonucleotide from a Single-Stranded Nucleotide Using Magnetic Beads and an Oligo Library." PLOS ONE 11, no. 3: e0149774.
A sensitive, selective, environmentally friendly, high-throughput, well-plate-based immunosorbent assay was developed to detect human α-fetoprotein (AFP) using carbon dots (C-Dots). Highly fluorescent C-Dots were synthesized using a one-step hydrothermal reaction, with citric acid serving as the carbon source and ethylene diamine acting as the nitrogen source. The reaction conditions were optimized to obtain the desired surface functionality. Then, the C-Dots were used to label one member of the anti-AFP pair (Ab2) via amine-amine coupling using glutaraldehyde. The capture anti-AFP (Ab1) was coated onto polystyrene well plates and bovine serum albumin (BSA) was used to block unsaturated binding sites. AFP was incubated in Ab1-coated wells; unbound AFP was then washed away with Tween-20. Next, the C-Dot-labeled Ab2 was added to form a sandwich immunocomplex with the AFP bound to the Ab1-coated wells. The fluorescence intensities detected from the C-Dots on these sandwich immunocomplexes were positively correlated to the concentrations of AFP antigen. A five-parameter logistic regression calibration curve was established between fluorescence and clinically important AFP concentrations (range: 0-350 ng/mL with a correlation coefficient of R(2) = 0.995). The results from the C-Dot-based immunoassay were in agreement with results from traditional immunoassays, which used horseradish peroxidase (HRP, R(2) = 0.964) and fluorescein isothiocyanate (FITC, R(2) = 0.973). These results indicated that C-Dots have great potential to be applied as biolabels for high-throughput well-plate-based immunoassays.
Yuanyuan Wu; Peng Wei; Sumate Pengpumkiat; Emily A. Schumacher; Vincent T. Remcho. Development of a Carbon Dot (C-Dot)-Linked Immunosorbent Assay for the Detection of Human α-Fetoprotein. Analytical Chemistry 2015, 87, 8510 -8516.
AMA StyleYuanyuan Wu, Peng Wei, Sumate Pengpumkiat, Emily A. Schumacher, Vincent T. Remcho. Development of a Carbon Dot (C-Dot)-Linked Immunosorbent Assay for the Detection of Human α-Fetoprotein. Analytical Chemistry. 2015; 87 (16):8510-8516.
Chicago/Turabian StyleYuanyuan Wu; Peng Wei; Sumate Pengpumkiat; Emily A. Schumacher; Vincent T. Remcho. 2015. "Development of a Carbon Dot (C-Dot)-Linked Immunosorbent Assay for the Detection of Human α-Fetoprotein." Analytical Chemistry 87, no. 16: 8510-8516.
We have developed a simple and direct method to fabricate paper-based microfluidic devices that can be used for a wide range of colorimetric assay applications. With these devices, assays can be performed within minutes to allow for quantitative colorimetric analysis by use of a widely accessible iPhone camera and an RGB color reader application (app) to measure color intensity. In the described laboratory experiment, students design and create their own microfluidic devices with common laboratory supplies such as Kimwipes, Parafilm, and a thermal laminator, and gain hands-on experience in the analysis of Fe2+ and Cu2+ by colorimetric determination.
Myra T. Koesdjojo; Sumate Pengpumkiat; Yuanyuan Wu; Anukul Boonloed; Daniel Huynh; Thomas P. Remcho; Vincent T. Remcho. Cost Effective Paper-Based Colorimetric Microfluidic Devices and Mobile Phone Camera Readers for the Classroom. Journal of Chemical Education 2015, 92, 737 -741.
AMA StyleMyra T. Koesdjojo, Sumate Pengpumkiat, Yuanyuan Wu, Anukul Boonloed, Daniel Huynh, Thomas P. Remcho, Vincent T. Remcho. Cost Effective Paper-Based Colorimetric Microfluidic Devices and Mobile Phone Camera Readers for the Classroom. Journal of Chemical Education. 2015; 92 (4):737-741.
Chicago/Turabian StyleMyra T. Koesdjojo; Sumate Pengpumkiat; Yuanyuan Wu; Anukul Boonloed; Daniel Huynh; Thomas P. Remcho; Vincent T. Remcho. 2015. "Cost Effective Paper-Based Colorimetric Microfluidic Devices and Mobile Phone Camera Readers for the Classroom." Journal of Chemical Education 92, no. 4: 737-741.
Phase transfer catalytic methylation was applied to directly derivatise chlorophenoxy acid herbicides in superheated water extracts from sand and soil samples. The extractions were carried out at 120 °C statically for 5 min and then dynamically for 10 min at 1.0 mL min−1 using water at pH 11.0 for a sand matrix and a flow rate of 0.5 mL min−1 at pH 7.0 for soil samples. The methylation was carried out on-line on the extraction solution with ultrasonication at 80 °C, using either 0.05 mmol tetrabutylammonium bromide (TBAB) or 0.0125 mmol cetyltrimethylammonium bromide (CTAB) as phase transfer catalysts with 0.20 mmol methyl iodide in 2.0 mL dichloromethane trapping solvent. The former catalyst provided a higher yield but the latter gave fewer interfering peaks. The recoveries of most chlorophenoxy acids using the TBAB catalyst ranged from 67 to 105% for sand and from 82 to 114% for soil sample, except phenoxyacetic acid, 2-(2, 4-dichlorophenoxy)propanoic acid and 1-naphthaleneacetic acid, while those by using CTAB were slightly lower. Detection limits of all the analytes extracted from sand using TBAB catalyst were in a range of 5.3–16 μg g−1 analysed by using gas chromatography with flame ionization detection (GC–FID).
Orapin Chienthavorn; Sumate Pengpumkiat; Athapol Noomhorm; Roger Smith. Superheated water extraction and phase transfer methylation of phenoxy acid herbicides from solid matrices. Journal of Chromatography A 2007, 1152, 268 -273.
AMA StyleOrapin Chienthavorn, Sumate Pengpumkiat, Athapol Noomhorm, Roger Smith. Superheated water extraction and phase transfer methylation of phenoxy acid herbicides from solid matrices. Journal of Chromatography A. 2007; 1152 (1-2):268-273.
Chicago/Turabian StyleOrapin Chienthavorn; Sumate Pengpumkiat; Athapol Noomhorm; Roger Smith. 2007. "Superheated water extraction and phase transfer methylation of phenoxy acid herbicides from solid matrices." Journal of Chromatography A 1152, no. 1-2: 268-273.