The mass food poisoning incident yusho occurred in Japan in 1968. It was caused by the ingestion of rice bran oil contaminated with polychlorinated biphenyls and various dioxins and dioxin-like compounds including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDFs). Notably, PCDFs were found to contribute to approximately 65% of the total toxicity equivalent in the blood of yusho patients. Lipophilic dioxins are retained in the body for a longer period than previously estimated. Victims suffered from characteristic skin manifestations associated with non-specific systemic symptoms, neurological symptoms, and respiratory symptoms. The severe symptoms seen in the initial phase subsequently faded, but recently, improvements have scarcely been observed. The Yusho Group has been researching treatments for this condition. Several clinical trials with chelating agents or dietary fibers aimed at accelerating the excretion of compounds. While some treatments increased dioxin excretion, none provided satisfactory symptom relief. Concurrently, various phytochemicals and herbal extracts have been found to possess biological activities that suppress dioxin-induced toxicity via aryl hydrocarbon receptor or activate the antioxidant nuclear factor-erythroid 2-related factor-2 (NRF2) signal pathway, making them promising therapeutic candidates. Here, we summarize the current status of yusho and findings of clinical trials for yusho patients and discuss the treatment prospects.
An improved method for the determination of chlorine in air is described. The principle of this method is based on the absorption of chlorine in p-toluenesulfonamide aqueous solution, followed by color development with a pyridine-pyrazolone reagent. Both the chlorine absorbed in the solution and the color developed with the reagent were stable. Positive interference by nitrogen dioxide was not observed. 相似文献
In 1999, Japanese domestic leafy vegetables were successively investigated for levels of dioxins, including 17 dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), four non-ortho co-planar PCBs (co-PCBs) and eight mono-ortho co-PCBs, all of which had been assigned toxic equivalency factors (TEFs) by WHO in 1997. The mean levels of dioxins in the edible portions were 0.07 (0.09) pg TEQ/g in spinach, 0.13 (0.14) pgTEQ/g in garland chrysanthemum, 0.01 (0.04) pg TEQ/g in mitsuba (marsh parsley) and 0.01 (0.03) pg TEQ/g in chingentsuai (Brassica Campestris var. chinesis), when non-detects were set to zero (and set to half the limit of detection). In order to understand the dioxin pollution of leafy vegetables in detail, a further investigation of dioxin levels in the tissues of spinach was conducted. As a result, the dioxin levels in the leaves were found to be higher than those in the stem and red collar, but they were much lower than those found in the primary and secondary roots, which are considerably affected by the soil, which is recognized as a sink of airborne dioxins. The dioxin levels in edible portions (leaves, stem and red collar) were obviously lower than those in non-edible portions (primary and secondary roots). In addition, from the finding that several lower-chlorinated PCDD/Fs and co-PCBs, namely 2,3,7,8-TCDD/F, 1,2,3,7,8-PeCDD, 1,2,3,7,8/2,3,4,7,8-PeCDFs, 1,2,3,7,8,9-HxCDD, 1,2,3,4,7,8-/1,2,3,6,7,8-HxCDFs, 3,3',4,4'-TCB, 2,3,3',4,4'-/2,3',4,4',5-PeCBs, and 2,3',4,4',5,5'-HxCB, were more highly represented in the dioxins in the leaves than in those in the secondary roots, it was suggested that in leafy vegetables the deposition of gaseous, presumably moderately volatile dioxins in leaf wax is another pollution pathway in addition to the adhesion of dioxin-contaminated particles including soil. 相似文献
TSP and PM2.5 samples were collected at Xi'an, China during dust storms (DSs) and several types of pollution events, including haze, biomass burning, and firework displays. Aerosol mass concentrations were up to 2 times higher during the particulate matter (PM) events than on normal days (NDs), and all types of PM led to decreased visibility. Water-soluble ions (Na+, NH4+, K+, Mg2+, Ca2+, F?, Cl?, NO3?, and SO42?). were major aerosol components during the pollution episodes, but their concentrations were lower during DSs. NH4+, K+, F?, Cl?, NO3?, and SO42? were more abundant in PM2.5 than TSP but the opposite was true for Mg2+ and Ca2+. PM collected on hazy days was enriched with secondary species (NH4+, NO3?, and SO42) while PM from straw combustion showed high K+ and Cl?. Firework displays caused increases in K+ and also enrichments of NO3? relative to SO42?. During DSs, the concentrations of secondary aerosol components were low, but Ca2+ was abundant. Ion balance calculations indicate that PM from haze and straw combustion was acidic while the DSs samples were alkaline and the fireworks' PM was close to neutral. Ion ratios (SO42?/K+, NO3?/SO42?, and Cl?/K+) proved effective as indicators for different pollution episodes. 相似文献
Regular sea urchins, which have pentaradial symmetry, have been believed to show no preference in which part of the body forward
they proceed with. Through use of circular statistics, we show that the regular sea urchin Hemicentrotus pulcherrimus had no preference with respect to what body part, as determined by Lovén’s system, should be anterior in locomotion. The
sea urchins, however, preferably proceeded with the body part, which had contacted with the aquarium walls at rest, forward.
When the contact part was artificially altered, the body part facing forward in the following proceeding changed accordingly:
the animals walked with the part that had contacted last forward. The biological significance of this behavior was discussed
in relation to the aggregation formation and homing behavior. 相似文献
Natural steroidal hormone estrone (E1) was treated with the white rot fungus Phanerochaete sordida YK-624 under ligninolytic condition with low-nitrogen and high-carbon culture medium. E1 decreased by 98% after 5 d of treatment and the activities of ligninolytic enzymes, manganese peroxidase (MnP) and laccase, were detected during treatment, which suggested that the disappearance of E1 is related to ligninolytic enzymes produced extracellularly by white rot fungus. Therefore, E1 was treated with MnP and laccase prepared from the culture of white rot fungi. HPLC analysis demonstrated that E1 disappeared completely in the reaction mixture after 1 h of treatment with either MnP or laccase. Using the yeast two-hybrid assay system, it was also confirmed that both enzymatic treatments completely removed the estrogenic activity of E1 after 2 h. These results strongly suggest that ligninolytic enzymes are effective in removing the estrogenic activity of E1. 相似文献
We developed a useful analytical method for the determination of polycyclic aromatic hydrocarbons (PAH) concentrations in the aerosol of China. We used an accelerated solvent extraction (ASE) method for the extraction of PAHs from the aerosol samples, in order to reduce the extraction time and the solvent volume used. The optimum purification method was developed, with aminopropylsilane chemically-bonded stationary-phase column chromatography, in order to remove many co-extractives which cannot be removed by conventional purification methods using silica-gel column chromatography. HPLC/fluorescence detection (FLD) was adopted as the analytical method, because it has very high sensitivity to PAH and it is easy to install, operate, and maintain as compared with GC/MS. With the analytical method developed in this study, the recovery and precision (RSD) for most of the PAHs ranged from 75% to 129% and from 2.8% to 22.7%, respectively. The concentrations of PAHs in the aerosol samples collected from October 2003 to April 2005 in Beijing, China were determined using the newly developed method. SigmaPAHs, which is the sum of the concentrations of all detected PAHs, was 177.8 +/- 239.9 ng m(-3) (n = 64). The SigmaPAHs concentration in the heating season (305.1 +/- 279.0 ng m(-3), n = 33) was 7.2 times higher than that in the non-heating season (42.3 +/- 32.0 ng m(-3), n = 31). These strong seasonal variations in atmospheric PAH concentration are possibly due to coal combustion for residential heating in winter. 相似文献
Ligninolytic enzymes, manganese peroxidase (MnP), laccase, and lignin peroxidase (LiP), from white-rot fungi were used in an attempt to treat methoxychlor (MC), a chemical widely used as a pesticide. MnP and laccase in the presence of Tween 80 and 1-hydroxybenzotriazole (HBT), respectively, and LiP were found to degrade MC, and MnP-Tween 80 decreased MC levels by about 65% after a 24-h treatment. MC was converted into methoxychlor olefin (MCO) and 4,4'-dimethoxybenzophenone by MnP-Tween 80 or laccase-HBT treatment. These results indicate that ligninolytic enzymes from white-rot fungi can catalyze the oxidative dechlorination of MC. Moreover, a metabolite MCO was also degraded by MnP-Tween 80 or laccase-HBT treatment. 相似文献