Previous studies have suggested that unidentified compounds constitute a large proportion of extractable organochlorine (EOCl) and extractable organobromine (EOBr) in the crude extracts without fractionation; however, the proportion of unidentified EOX (X = chlorine, bromine) associated with high-/low-molecular-weight compounds is still unknown. In this study, we applied gel permeation chromatography to fractionate extracts from archived liver samples of high-trophic marine and terrestrial mammals (striped dolphins, cats, and raccoon dogs), for which concentrations of legacy organohalogen contaminants (polychlorinated biphenyls, organochlorine pesticides, and polybrominated diphenyl ethers [PBDEs]) had been previously reported. EOX in high- (>1000 g/mol) and low- (≤1000 g/mol) molecular-weight fractions (EOX-H and EOX-L) were determined by neutron activation analysis.
View Article and Find Full Text PDFHuman carboxylesterase 1 (hCES1) is a hydrolase that is mainly expressed in the liver and lung and plays the most important role in the metabolic activation of ester-type prodrugs. In this study, design, synthesis and evaluation of water-soluble phenytoin prodrugs were performed with consideration of the substrate recognition ability of hCES1. The phenytoin prodrugs were synthesized in two steps without column chromatography.
View Article and Find Full Text PDFChromium is commonly found in the flue gases and ashes of Municipal Solid Waste Incineration. It has been reported as an active catalyst for the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) during de novo tests, yet its specific mode of action has remained unclear. This study aims to identify the effects of chromium chloride on the formation of PCDD/F and other chloro-aromatics and to elucidate the underlying reaction mechanisms.
View Article and Find Full Text PDFThe incineration of waste carbon nanomaterials will become an inevitable waste management strategy following the disposal of products containing carbon nanomaterials. We investigated the formation of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) during the incineration of selected carbon nanomaterials [fullerene (C), single-walled carbon nanotubes (SWNTs), and graphene], with sodium chloride and trace copper at 850 °C in air using a laboratory-scale electric furnace. Most PCDD/Fs and PCBs were concentrated in particulate fly ash post-incineration, and in low-temperature zones in the furnace (54-670 °C).
View Article and Find Full Text PDFOpen burning of electronic waste (E-waste) produces numerous organochlorine compounds (OCs). Although the presence of unidentified OCs has been suggested, the mass balance of identified and unidentified OCs in E-waste open burning soils (EOBSs) still remains unknown. In this study, the concentrations of Cl bonded with aromatic carbon (aromatic-Cl) and aliphatic carbon (aliphatic-Cl), and inorganic Cl in EOBSs were determined by focusing on chlorine (Cl) in water-insoluble fractions (insoluble Cl) and applying Cl K-edge X-ray absorption spectroscopy in conjunction with combustion ion chromatography.
View Article and Find Full Text PDFBackground: Positron emission tomography (PET), using 18F-fluoro-2-deoxy-D-glucose (FDG) as a tracer, can detect malignant neoplasms with altered glucose metabolism. To clarify the usefulness of FDG-PET for detecting gastric cancer, we evaluated preoperative PET imaging in gastric cancer patients.
Methods: Sixty-two gastric cancer patients who underwent FDG-PET imaging and gastric resection with lymphadenectomy were evaluated.