Hydrogel/microcarrier cell scaffolds for rapid expansion of satellite cells from large yellow croakers: Differential analysis between 2D and 3D cell culture.

Cell culture meat is based on the scaled-up expansion of seed cells. The biological differences between seed cells from large yellow croakers in the two-dimensional (2D) and three-dimensional (3D) culture systems have not been explored. Here, satellite cells (SCs) from large yellow croakers (Larimichthys crocea) were grown on cell climbing slices, hydrogels, and microcarriers for five days to analyze the biological differences of SCs on different cell scaffolds. The results exhibited that SCs had different cell morphologies in 2D and 3D cultures. Cell adhesion receptors (Itgb1andsdc4) and adhesion spot markervclof the 3D cultures were markedly expressed. Furthermore, myogenic decision markers (Pax7andmyod) were significantly enhanced. However, the expression of myogenic differentiation marker (desmin) was significantly increased in the microcarrier group. Combined with the transcriptome data, this suggests that cell adhesion of SCs in 3D culture was related to the integrin signaling pathway. In contrast, the slight spontaneous differentiation of SCs on microcarriers was associated with rapid cell proliferation. This study is the first to report the biological differences between SCs in 2D and 3D cultures, providing new perspectives for the rapid expansion of cell culture meat-seeded cells and the development of customized scaffolds.

Preparation of Novel Sea Cucumber Intestinal Peptides to Promote Tibial Fracture Healing in Mice by Inducing Differentiation of Hypertrophic Chondrocytes to the Osteoblast Lineage.

SCOPE: Hypertrophic chondrocytes have a decisive regulatory role in the process of fracture healing, and the fate of hypertrophic chondrocytes is not only apoptosis. However, the mechanism of sea cucumber (Stichopus japonicus) intestinal peptide (SCIP) on fracture promotion is still unclear. This study aims to investigate the effect of sea cucumber intestinal peptide on the differentiation fate of hypertrophic chondrocytes in a mouse tibial fracture model. METHODS AND RESULTS: Mice are subjected to open fractures of the right tibia to establish a tibial fracture model. The results exhibit that the SCIP intervention significantly promotes the mineralization of cartilage callus, decreases the expression of the hypertrophic chondrocyte marker Col X, and increases the expression of the osteoblast marker Col I. Mechanically, SCIP promotes tibial fracture healing by promoting histone acetylation and inhibiting histone methylation, thereby upregulating pluripotent transcription factors induced the differentiation of hypertrophic chondrocytes to the osteoblast lineage in a manner distinct from classical endochondral ossification. CONCLUSION: This study is the first to report that SCIP can promote tibial fracture healing in mice by inducing the differentiation of hypertrophic chondrocytes to the osteoblast lineage. SCIP may be considered raw material for developing nutraceuticals to promote fracture healing.

Isolation and Identification of a Novel Anti-Dry Eye Peptide from Tilapia Skin Peptides Based on In Silico, In Vitro, and In Vivo Approaches.

Tilapia skin is a great source of collagen. Here, we aimed to isolate and identify the peptides responsible for combating dry eye disease (DED) in tilapia skin peptides (TSP). In vitro cell DED model was used to screen anti-DED peptides from TSP via Sephadex G-25 chromatography, LC/MS/MS, and in silico methods. The anti-DED activity of the screened peptide was further verified in the mice DED model. TSP was divided into five fractions (TSP-I, TSP-II, TSP-III, TSP-IV, and TSP-V), and TSP-II exerted an effective effect for anti-DED. A total of 131 peptides were identified using LC/MS/MS in TSP-II, and NGGPSGPR (NGG) was screened as a potential anti-DED fragment in TSP-II via in silico methods. In vitro, NGG restored cell viability and inhibited the expression level of Cyclooxygenase-2 (COX-2) protein in Human corneal epithelial cells (HCECs) induced by NaCl. In vivo, NGG increased tear production, decreased tear ferning score, prevented corneal epithelial thinning, alleviated conjunctival goblet cell loss, and inhibited the apoptosis of corneal epithelial cells in DED mice. Overall, NGG, as an anti-DED peptide, was successfully identified from TSP, and it may be devoted to functional food ingredients or medicine for DED.

Peptides from Antarctic krill (Euphausia superba) ameliorate acute liver injury in mice induced by carbon tetrachloride via activating the Nrf2/HO-1 pathway.

This study aimed to evaluate the hepatoprotective effects of peptides from Antarctic krill (AKP) on carbon tetrachloride (CCl4)-induced acute liver injury (ALI) in mice and the underlying molecular mechanisms. ICR mice were pretreated with AKP (500 mg kg-1, i.g.) and silybin (30 mg kg-1, i.g.) for 15 days before CCl4 (0.25 mL per kg BW, i.p.) injection. To assess hepatocellular damage and molecular indices, the serum and liver tissue were evaluated at harvest. The results showed that AKP pretreatment remarkably attenuated CCl4-induced liver injury, which was identified by the decrease in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), alleviation of hepatocyte necrosis, and inhibition of the levels of the pro-inflammatory factors TNF-α and IL-1ß compared to those for silymarin. AKP pretreatment also enhanced the redox balance by reducing the concentrations of MDA and 8-iso-PG and increasing the activities of SOD, GSH and GSH-PX in the liver of mice. In addition, AKP upregulated oxidative stress-related mRNA expressions of Nrf2, Keap1, HO-1, and NQO1 and further activated the protein expression on the Nrf2/HO-1 singling pathway. In summary, AKP might be a promising hepatoprotective nutraceutical against ALI and its underlying mechanisms are associated with activation of the Nrf2/HO-1 pathway.

DHA- and EPA-Enriched Phosphatidylcholine Suppress Human Lung Carcinoma 95D Cells Metastasis via Activating the Peroxisome Proliferator-Activated Receptor γ.

The antineoplastic effects of docosahexaenoic acid-containing phosphatidylcholine (DHA-PC) and eicosapentaenoic acid-containing phosphatidylcholine (EPA-PC) were explored, and their underlying mechanisms in the human lung carcinoma 95D cells (95D cells) were investigated. After treatment of 95D cells with DHA-PC or EPA-PC, cell biological behaviors such as growth, adhesion, migration, and invasion were studied. Immunofluorescence and western blotting were carried out to assess underlying molecular mechanisms. Results showed that 95D cells proliferation and adherence in the DHA-PC or EPA-PC group were drastically inhibited than the control group. DHA-PC and EPA-PC suppressed the migration and invasion of 95D cells by disrupting intracellular F-actin, which drives cell movement. The protein expression of PPARγ was induced versus the control group. Furthermore, critical factors related to invasion, including matrix metallopeptidase 9 (MMP9), heparanase (Hpa), and vascular endothelial growth factor (VEGF), were drastically downregulated through the PPARγ/NF-κB signaling pathway. C-X-C chemokine receptor type 4 (CXCR4) and cofilin were significantly suppressed via DHA-PC and EPA-PC through the PPARγ/phosphatase and tensin homolog (PTEN)/serine-threonine protein kinase (AKT) signaling pathway. DHA-PC and EPA-PC reversed the PPARγ antagonist GW9662-induced reduction of 95D cells in migration and invasion capacity, suggesting that PPARγ was directly involved in the anti-metastasis efficacy of DHA-PC and EPA-PC. In conclusion, DHA-PC and EPA-PC have great potential for cancer therapy, and the antineoplastic effects involve the activation of PPARγ. EPA-PC showed more pronounced antineoplastic effects than DHA-PC, possibly due to the more robust activation of PPARγ by EPA-PC.

Tilapia Skin Peptides Ameliorate Cyclophosphamide-Induced Anxiety- and Depression-Like Behavior via Improving Oxidative Stress, Neuroinflammation, Neuron Apoptosis, and Neurogenesis in Mice.

Anxiety- and depression-like behavior following chemotherapy treatment occurs in cancer patients with high probability and no specific therapeutics are available for treatment and prevention of this complication. Here, tilapia skin peptides (TSP), a novel enzymatically hydrolyzed bioactive peptide mixture, obtained from tilapia (Oreochromis mossambicus) scraps, were studied on cyclophosphamide (CP)-induced anxiety- and depression-like behavior in mice. Mice were received intraperitoneal injection of CP for 2 weeks, while TSP was administered for 4 weeks. After the end of the animal experiment, behavioral, biochemical, and molecular tests were carried out. The mice decreased preference for sugar water, increased immobility time in the forced swimming and tail suspension test, and decreased travel distance in the open field test in the Model group, compared with the Control group. Abnormal changes in behavioral tests were significantly improved after the TSP treatment. Additionally, abnormalities on superoxide dismutase, malondialdehyde, glutathione peroxidase were rescued by administration of 1000 mg/kg/d TSP in mice than that of the Model group. TSP has normalized the expression of Iba-1 and the levels of TNF-α and IL-1ß in the hippocampus of mice, which indicated that TSP could observably ameliorate neuroinflammatory response in the hippocampus of mice. TSP ameliorated the apoptosis of hippocampal neurons of CA1 and CA3 regions in the TSP group vs. the Model group. The number of doublecortin positive cells was drastically increased by administering 1000 mg/kg/d TSP in mice vs. the Model group. Furthermore, TSP reversed the Nrf2/HO-1 signaling pathway, BDNF/TrkB/CREB signaling pathway, and reduced the Bcl-2/Bax/caspase-3 apoptosis pathway. In conclusion, TSP could restore CP-induced anxiety- and depression-like behavior via improving oxidative stress, neuroinflammation, neuron apoptosis, and neurogenesis in mice hippocampus.

Immobilization on magnetic PVA/SA@Fe3O4 hydrogel beads enhances the activity and stability of neutral protease.

Enzyme immobilization technology has a key role in improving the stability of enzyme reaction systems and biocatalyst utilization rates. In this study, polyvinyl alcohol/sodium alginate@Fe3O4 (PVA/SA@Fe3O4) magnetic immobilized-enzyme hydrogel beads were prepared. Their structure and morphology were characterized by scanning electron microscopy, surface area and porosity analyses, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and a vibrating sample magnetometer. The capability of PVA/SA@Fe3O4 to adsorb neutral protease was investigated with variations in composition, temperature, pH, stirring speed, enzyme concentration, and crosslinking concentration. The optimal parameters of the immobilization process were determined by response surface methodology (3% neutral protease, 4% crosslinking at 200 rpm, 45 °C and pH 7.2), under which an immobilization rate of 41.98 mg/g was obtained. The thermal stability, acid-base stability, and reusability of the immobilized enzyme were improved significantly. After seven cycles, the immobilized enzyme activity remained at 30.8% that of the initial enzyme activity. The results indicate that the immobilization of NP onto magnetic PVA/SA@Fe3O4 hydrogel beads improves enzyme efficiency, giving this process potential industrial applications.

Tilapia skin peptides restore cyclophosphamide-induced premature ovarian failure via inhibiting oxidative stress and apoptosis in mice.

Tilapia (Oreochromis mossambicus) skin high value-added compounds have not been fully utilized in tilapia processing. Here, the protective effects of tilapia skin peptides (TSP) on primary ovarian failure (POF) and their underlying mechanisms in mice were investigated. Cyclophosphamide (CP) was injected intraperitoneally (ip) for 14 days (10 mg kg-1 d-1) to establish a mouse model of POF. At the same time, the mice were given intragastrically (ig) TSP for 30 days (250 mg kg-1 d-1, 500 mg kg-1 d-1, and 1000 mg kg-1 d-1, respectively). The ovarian index, estrous cycle, hormone level, changes in the number of follicles at various levels, and biochemical tests were carried out at the end of the experiment. The body weight and ovarian index of mice in the POF group were markedly lower than that of the control group. Treatment with TSP reversed these changes significantly. TSP administration significantly restored the estrous cycle disorder of the mice versus that of the POF group. The level changes of progesterone (P), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) induced by CP were significantly reversed by TSP treatment. TSP inhibited oxidative stress in CP-induced mice by enhancing the total superoxide dismutase (T-SOD) activity and reducing malondialdehyde (MDA) levels in the ovaries. TSP improved the apoptosis of ovarian granulosa cells in CP-induced mice compared with the POF group. Furthermore, TSP regulated the Bcl-2/Bax/caspase-3 apoptosis pathway and enhanced the Nrf2/HO-1 signaling pathway. In conclusion, TSP could improve CP-induced POF via alleviating ovarian oxidative stress and granulosa cell apoptosis.

Parent-Child Attachment and Social Adaptation Behavior in Chinese College Students: The Mediating Role of School Bonding.

Family and school are two main places for adolescents to develop socialization, which can be contributed by good parent-child attachment and school bonding. Earlier studies suggested that parent-child attachment played an important role in promoting the formation of high-level school bonding, which is also likely to influence social adaptation. This study aimed to explore the relationship between parent-child attachment and social adaptation, and the mediating role of school bonding. Using stratified cluster sampling, 1,440 college students were first randomly selected from four universities and then stratified by specialty with a balance between genders and grades. Participants voluntarily participated in this study and completed questionnaires including the Parent-Child Attachment Scale, School Bonding Scale, and Social Adaptation Scale. Finally, a total of 1,320 college students were included in the analysis (59.5% female; aged 18-24years, Mage=20.39±1.52years). Data analysis and structural equation modeling were conducted using SPSS 22.0 and AMOS 23.0. The results indicated that the overall level of parent-child attachment in females (M=75.72, SD=12.36) was significantly higher than that of males (M=73.71, SD=12.68; F=8.22, p<0.01). Difference was also found between sibling status (F=13.90, p<0.001), and the only-child (M=76.16, SD=12.72) scored significantly higher than their counterparts (non-only children, M=73.60, SD=12.19). Parent-child attachment was positively correlated with social adaptation (p<0.01) and school bonding (p<0.01), while school bonding was also positively correlated with social adaptation score (p<0.01). School bonding played a partial intermediate role in the relationship between parent-child attachment and social adaptation (ß=0.15). Our research identified a direct influence of parent-child attachment and an indirect influence via school bonding on social adaptation among college students.

Applicability of Enchytraeus bulbosus as a model species in ecotoxicology and risk assessment.

Enchytraeus bulbosus is listed in the ISO and OECD standard guidelines as a possible test species of enchytraeid. However, in contrast to other listed species, its applicability in ecotoxicological studies as well as its sensitivity is widely unknown. Therefore, copper, pentachlorophenol(PCP), carbendazim, and chloroacetamide have been investigated by performing two-generation studies with multiple endpoints. Comparable toxicity trends to the existing studies were shown for copper and PCP in the two-generation studies of E. bulbosus. Dose-related abnormal swelling of clitella were found for the first time with PCP and chloroacetamide treatments. Sensitivity comparisons of E. bulbosus to other terrestrial test species were also conducted. E. bulbosus showed high sensitivity, it has comparable sensitivity as other sensitive species of genus Enchytraeus ( E. albidus or E. luxuriosus)to different chemicals, and was more sensitive than E. crypticus and earthworm species ( Eisenia fetida or Eisenia andrei). Combined with the phylogenetic and biological characterization, the results lead to the conclusion that E.bulbosus is a suitable model species in ecotoxicology and the chemical risk assessment (especially in multi-generation) because it has a short generation time, comparatively moderate fecundity, ideal and reasonable sensitivity.

Hydroxytyrosol alleviates oxidative stress and neuroinflammation and enhances hippocampal neurotrophic signaling to improve stress-induced depressive behaviors in mice.

Hydroxytyrosol (HT), the main phenolic compound in olives and olive products, has antioxidative, anti-inflammatory, neuroprotective, and other physiological functions. The effects of HT on depression are unclear. The aim of this study was to explore the effects of HT on chronic unpredictable mild stress (CUMS) induced depressive-like behaviors. Mice were exposed to CUMS for 9 weeks and then treated with HT beginning in the second week and continuing for 7 weeks. Behavioral, biochemical, and molecular tests were conducted at the end of the experiment. The sucrose preference was significantly decreased in the CUMS group versus the healthy control group. Also, immobility times in forced swimming and tail suspension tests were increased in CUMS-induced mice, but treatment with HT significantly reversed this change. HT ameliorated oxidative stress in CUMS-exposed mice by enhancing superoxide dismutase activity and reducing reactive oxygen species and malondialdehyde levels in the hippocampus. HT administration significantly suppressed microglia activation and inhibited the expression of tumor necrosis factor alpha and interleukin 1 beta in the hippocampus versus the untreated group. The expression level of glial fibrillary acidic protein (GFAP) and the number of GFAP-immunoreactive astrocytes in the hippocampus were significantly augmented by HT. Furthermore, HT treatment increased the expression of hippocampal brain-derived neurotrophic factor (BDNF), phosphorylated tropomyosin receptor kinase B (p-TrkB), and phosphorylated c-AMP response element binding protein (p-CREB) compared with the untreated CUMS group. Overall, HT improved CUMS-induced depressive-like behaviors in mice by alleviating oxidative stress and neuroinflammation and by enhancing the BDNF/TrkB/CREB signaling pathway.

Analysis of 58 poly-/perfluoroalkyl substances and their occurrence in surface water in a high-technology industrial park.

Poly/perfluoroalkyl substances (PFASs) have some water solubility so that they are more liable to enter surface water. A comprehensive analysis method was established to analyze 17 classes of 58 PFASs in surface water by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after automated solid phase extraction (SPE). The method showed acceptable recoveries and precision with recoveries of 60%-130% and RSD less than 30% with a few exceptions, and method detection limits (MDLs) of 0.004 ng/L-2.0 ng/L. It was investigated the surface water around Zhangjiang High-Technology Park in Shanghai. The concentration of ∑PFASs ranged from 115 ng/L to 600 ng/L. The main pollutant was perfluoro-3-methylheptanoic acid (P3MHpA), which is isopropyl isomer of perfluorooctanoic acid (PFOA), accounting 41.6% of ∑PFASs. It was detected in all samples and its level was far higher than that of PFOA with the maximum of 432 ng/L determined surrounding integrated circuits company. Short-chain perfluorocarboxylic acids (PFCAs) and PFOA were also major constituents accounting for 39.9% of ∑PFASs. Perfluorosulfonic acid (PFSAs (C4, 6, 8)) were detected in all samples, while most concentrations were below 10 ng/L. In addition, 1H,1H,2H,2H-perfluorooctane sulfonate (6:2) (6:2 FTS), 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-propanoic acid (HFPO-DA) and 9-chlorohexadecafluoro-3-oxanonane-sulfonate (9Cl-PF3ONS) were also detected in all samples at low level. Long chain PFCAs and PFSAs and other classes of PFASs were also detected with low levels and/or low frequencies. The level of PFASs shows an increasing trend in surface water in Shanghai. The whole risk is low for residents from water exposure, while it should cautious to the emission of P3MHpA from integrated circuits and its potential risk.

Read-across: Principle, case study and its potential regulatory application in China.

Read-across, has generated much attention and has been used in many regulatory schemes as an alternative approach to testing globally. The regulatory application of read-across in the chemical management in China is progressing but still limited. A workshop on the "Read-across: Principle, case study and its potential regulatory application in China", organized by the Chemical Risk Assessment Specialty Group under the Committee of Industrial Toxicology of Chinese Society of Toxicology, was held on May 28, 2019 to discuss the potential broader application and acceptance of read-across to support chemical risk assessment in China. The Workshop included global experts from regulatory agencies, academia and industry. Scientific presentations and constructive discussions raised awareness on the use of read-across in different regions, identified barriers to regulatory acceptance, and participants also brainstormed on practical strategies to help facilitate the further regulatory application of read-across approaches in China.

Atmospheric bulk deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the vicinity of MSWI in Shanghai, China.

Atmospheric bulk deposition samples were gathered month by month throughout a year at two sites in vicinity of a MSWI in Shanghai, to carry out an investigation on the atmospheric bulk deposition fluxes and seasonal variations of polychlorinated dibenzo-p-dioxinsand dibenzofurans (PCDD/Fs). The atmospheric bulk deposition fluxes of PCDD/Fs ranged from 23.5 to 560 pg m-2·d-1 (1.01-23.9 pg WHO-TEQ·m-2·d-1), with an average value of 136 pg m-2·d-1 (5.08 pg WHO-TEQ·m-2·d-1) in the Vicinity of the MSWI in Shanghai. The measured concentrations were well compared with those from urban or industrial sites in other regions in China and abroad. The seasonal trend of atmospheric bulk deposition fluxes of PCDD/Fs throughout a year exhibited as high levels in summer, moderate levels in winter, and low levels in spring and autumn. The principal component analysis (PCA) indicated not only the MSWI, but also vehicle emission was the indispensable source of PCDD/Fs in the vicinity of the MSWI, especially for the urban areas. The positive matrix factorization (PMF) apportioned 5 source categories: MSWI, diesel vehicles, atmosphere background, industrial combustion and un-leaded gas vehicles, accounting for 43.3%, 38.1%, 6.89%, 6.19% and 5.50% in average, respectively of PCDD/Fs in atmospheric bulk deposition in the vicinity of the MSWI in Shanghai, China.

Occurrence and health risk assessment of pharmaceutical and personal care products (PPCPs) in tap water of Shanghai.

A monitoring study of 71 pharmaceuticals and personal care products (PPCPs) in tap water covered all districts of Shanghai. Nineteen PPCPs were detected in all samples, and most of them were detected with high concentration. Ten compounds were found with highest concentrations and their detection frequencies were over 80%, included thiamphenicol  (101.54 ng/L), florfenicol (84.56 ng/L), valsartan (66.84 ng/L), irbesartan (38.35 ng/L) hydrochlorothiazide (33.13 ng/L), 4-acetaminopyrine (48.16 ng/L), propylparaben (47.50 ng/L), dicyclohexylamine (42.33 ng/L), primidone (32.85 ng/L) and bisphenol A (31.51 ng/L). Only 6 PPCPs were not detected in all samples. Detection frequency of PPCPs was between 50% and 70% in most tap waters, but the total concentration of PPCPs ranged from 71.6 to 361 ng/L. Phenicols was the dominant type with average value of 100 ng/L, accounting for over 50% of most samples, followed by cardiovascular and psychotropic drugs with average value of 26.3 and 12.1 ng/L, respectively. In general, the residues of PPCPs in tap water of suburb were higher than those in central districts. The maximum residues happened in D district with the average concentration of 355 ng/L, followed by J, H and Cb districts with the average concentration of 269, 251 and 215 ng/L. In the same district, the content and distribution of PPCPs in tap waters were similar supplied by different water treatment plants. While those are some differences among tap waters inlet from the same water sources. Individual compound was expected to pose a negligible risk to human health with risk quotients (RQ) less than 1, except primidone which may pose potential risk to infants.

Tracking pollutants in dietary fish oil: From ocean to table.

Dietary fish oil used in aquafeed transfers marine pollutants to farmed fish. However, the entire transfer route of marine pollutants in dietary fish oil from ocean to table fish has not been tracked quantitatively. To track the entire transfer route of marine pollutants from wild fish to farmed fish through dietary fish oil and evaluate the related human health risks, we obtained crude and refined fish oils originating from the same batch of wild ocean anchovy and prepared fish oil-containing purified aquafeeds to feed omnivorous lean Nile tilapia and carnivorous fatty yellow catfish for eight weeks. The potential human health risk of consumption of these fish was evaluated. Marine persistent organic pollutants (POPs) were concentrated in fish oil, but were largely removed by the refining process, particularly dioxins and polychlorinated biphenyls (PCBs). The differences in the POP concentrations between crude and refined fish oils were retained in the fillets of the farmed fish. Fillets fat content and fish growth were positively and negatively correlated to the final POPs deposition in fillets, respectively. The retention rates of marine POPs in the final fillets through fish oil-contained aquafeeds were 1.3%-5.2%, and were correlated with the POPs concentrations in feeds and fillets, feed utilization and carcass ratios. The dietary crude fish oil-contained aquafeeds are a higher hazard ratio to consumers. Prohibiting the use of crude fish oil in aquafeed and improving growth and feed efficiency in farmed fish are promising strategies to reduce health risks originating from marine POPs.

Preliminary ecotoxicity hazard evaluation of DOPO-HQ as a potential alternative to halogenated flame retardants.

Recent regulatory and environmental pressures have led to increasing demands for environmentally friendly flame retardants as alternatives to halogenated flame retardants (HFRs). A new flame retardant alternative, 10-(2, 5-dihydroxyl phenyl)-9, 10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide (DOPO-HQ), was applied due to its high thermal stability and glass transition temperature. However, there is little information available for its ecotoxicology. For this purpose, the preliminary ecotoxicity of DOPO-HQ was investigated and evaluated, using aquatic, terrestrial and microorganism toxicity according to Organization for Economic Co-operation and Development (OECD) guidelines under the framework of the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation. No effect was observed on Pseudokirchneriella subcapitata, Daphnia magna and Gobiocypris rarus at the saturation water solubility. For active sludge, Eisenia foetida and seedling emergence, no effect was observed at the limited highest concentration of 1000 mg/L or 1000 mg kg-1 dw. However, moderate effect on the shoot weight is observed with the maximum inhibition rate of 46.3% when exposed to 1000 mg kg-1 dw. Comparing the ecotoxicity of DOPO-HQ with that of HFRs and their typical alternatives, the toxicity of DOPO-HQ is markedly lower than those of triphenyl phosphate (TPP) and HFRs such as tris(2-chloro-1-methylethyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCCP), tris(2-chloroethyl) phosphate (TCEP) and tetrabromobisphenol A (TBBPA). Similar low effect levels were observed for resorcinol bis (biphenyl) phosphate (RDP), bisphenol A bis (biphenyl) phosphate (BDP) and its parent chemical 9, 10-dihydro-9-oxa-10-phosphaphenanthrene -10-oxide (DOPO). DOPO-HQ could be a potential alternative to HFRs from an environmental perspective.

Endpoint sensitivity in fish endocrine disruption assays: regulatory implications.

Identifying potential endocrine disrupting chemicals (EDCs) needs screening and testing for mode of action (MOA) and intrinsic toxicological properties. MOA is often indicated by biomarker endpoints, whereas toxicity by apical endpoints. Risk assessment is mainly based on apical but not on biomarker endpoints. The 21-day fish assay (OECD TG229) is considered a screening test. But it includes both biomarker and apical endpoints. This study explores the utility of results of the 21-day fish assay for risk assessment purposes. Endpoint sensitivity was analysed by compiling 142 data sets for 21-day fish assays and 38 data sets for the fish sexual development test (FSDT), encompassing 62 chemicals with different MOAs. Conclusions from this analysis include: (1) vitellogenin (VTG), fecundity and gonad histology are the most sensitive endpoints for fathead minnow, medaka and zebrafish in 21-day fish assays; secondary sex characteristics (SSC) are a less sensitive endpoint and is likely inadequate to detect all known MOAs. (2) Biomarker endpoints like VTG and apical endpoints like fecundity from the 21-day fish assay can be used for risk assessment. (3) Lowest observed effect concentrations (LOECs) of the most chemicals are comparable for the 21-day fish assay and for the FSDT, further supporting that results of 21-day fish assays can be used for risk assessment. However, a significant difference in LOECs was observed for some chemicals, suggesting that chemical specific effects should be taken into account. This paper emphasizes that a weight of evidence approach is important for interpretation of results of the 21-day fish assay.

Pilot study of the polychlorinated dibenzo-p-dioxins and dibenzofurans level in agricultural soil in Shanghai, China.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in agricultural soil samples from Shanghai to determine levels and to identify possible dioxin sources. The dioxin level was measured by an enzyme immunoassay method, US EPA 4025 (modified), which provides results as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents. The Method 4025m results obtained from 60 soil samples displayed a normal distribution, ranging from 2.8 to 23.4 pg/g 2378-TCDD-equvalents, with an average of 11.0 pg/g. The result also revealed a similar PCDD/Fs concentration among crop usage patterns, but differences by geographic region, low in the southwest of Shanghai and considerably higher in the northwest region. In contrast, the dioxin concentrations on Chongming Island were fairly homogeneous, with a range 10-15 pg/g. This immunoassay method is an effective high throughput screening tool which helps to minimize the need for more expensive analyses.

A method for genotoxicity detection using random amplified polymorphism DNA with Danio rerio.

The increasing presence of genotoxic pollutants in the aquatic environment has led to the development of quick monitoring methods. We have applied the random amplified polymorphism DNA (RAPD) method to evaluate the toxic effects of genotoxic chemicals. In all 22 normal wide-type Danio rerio (zebrafish), 78 amplified bands were obtained after PCR using the primer set, in which the frequency of emergence above 60% is 21. There do exist four stable bands in the amplified product, which appear in all normal test samples. The zebrafish RAPD fingerprinting database is set up on this base. The RAPD pattern from zebrafish exposed to genotoxic chemicals such as cyclophosphamide in dilution series ranging from 0.1 to 10 mg/L and dimethoate in dilution series ranging from 1.0 to 100 mg/L displayed some changes in polymorphism band patterns including the lost of stable bands. There also exists a distinct distance between the band patterns of exposed zebrafish and the control samples via the cluster method. In addition to that, the result derived from numerical analysis is more sensitive to the result obtained from stable band analysis because it can reveal the distance between the band pattern of the zebrafish exposed to 0.05 mg/L cyclophosphamide and the control sample. These results proved the accuracy and the sensitivity of the two analyses of genotoxicity effect based on RAPD fingerprinting research.