Objective:To develop an indirect enzyme-linked immunosorbent assay (ELISA) for semi-quantification of major allergen parvalbumin in fish.Methods:The soluble proteins were prepared from both white and dark muscles of seven species of freshwater fish and five species of marine fish.Tricine-SDS-PAGE and Western blot were performed to examine the protein patterns of fish muscle extracts.Natural parvalbumin being used to make calibration curve was purified from silver carp (Hypophthalmichthy molitrix) by ammonium sulphate fractionation,followed by ion exchange and gel filtration chromatography.The molecular mass of purified protein was estimated by Tricine-SDS-PAGE and identified by Western blot with anti-frog parvalbumin monoclonal antibody PARV-19.ELISA using PARV-19 was carried out to evaluate parvalbumin contents in white and dark muscles.Results:Tricine-SDS-PAGE revealed species-specific differences in proteins of heated extracts.Western blot confirmed that the major bands were showed in Tricine-SDS-PAGE with the molecular masses of 10-14 kD corresponded to parvalbumins recognized by PARV-19 and various numbers of isoforms of parvalbumin existed in different species of fish.There might be some differences in the parvalbumin contents and the epitope region was recognized by PARV-19 based on the differences in relative intensities of protein immunodetection.The ELISA showed that the contents of parvalbumin were 4 to 33 folds higher in the white muscle than in the dark muscle and varied greatly in different species of fish.Conclusion:These results validate that the dark muscle might be less allergenic than the white muscle due to the lower content of parvalbumins,and it is suggested that the commercial anti-parvalbumin antibody PARV-19 can be used to detect parvalbumins from the commercially important species of fish tested in this study and the method we develope succeeds to detect the major allergen in various species of fish.

Objective: To investigate the association between the internal exposure levels of phthalic acid esters (PAEs) and executive function (EF) of preschool children. Methods: Between October 2008 and October 2010, pregnant women who accepted pregnancy health care services in four municipal medical and health institutions in Ma'anshan city, Anhui Province, were recruited as study objects. A total of 5 084 pregnant women and 4 669 singleton live births were enrolled in this cohort. The follow-up study was conducted from April 2014 to April 2015. A total of 3 725 data-completed preschool children aged 3 to 6 years older entered in this study. The method of analysis seven metabolites of phthalates in urine was high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and divided objects into low (P₀-P₂₄), medium (P₂₅-P₇₄) and high (P₇₅-P₁₀₀) groups according to their exposure concentrations. To investigate the executive function of preschool children, we used the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P). Univariate and multivariate statistical method was used to analyze the etiology association between the phthalate metabolites levels and preschool children's executive function. Results: In this study, 53.6% (1 997/3 725) of preschoolers were boys, children's age was (51.5±5.6) months. The detection rates of seven phthalate esters were: mono-n-methyl phthalate (MMP) was 99.89% (3 721/3 725); mono-ethyl phthalate (MEP) was 99.97% (3 724/3 725); mono-benzyl phthalate (MBzP) was 69.10% (2 574/3 725); mono-butyl phthalate (MBP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono- (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were 100.00% and mono-ethylhexyl phthalate (MEHP) was 99.95% (3 723/3 725). The median concentrations of the seven phthalate metabolites were: 17.71, 15.36, 0.07, 155.24, 10.73, 14.67, 3.59 µg/L, respectively. The median concentrations corrected by urinary creatinine were 29.65, 26.65, 0.12, 257.73, 17.94, 24.80, 6.27 µg/g Cr, respectively. The P₂₅ and P₇5 concentration of the total PAEs metabolites corrected by urinary creatinine were 1.20 µmol/g Cr and 3.04 µmol/g Cr. After adjusted the relevant demographic information: children sex, children age in month, maternal age, parental education levels, household exposure to secondhand smoke and whether the child is the only child as confounds, multivariate logistic regression model showed that the risk of inhibitory self-control index (ISCI) dysplasia in MEHHP high concentration group and MEOHP high concentration group were 1.71 and 1.54 times (OR=1.71, 95% CI: 1.11-2.62; OR=1.54, 95% CI: 1.01-2.34) than in low concentration group. The risk of ISCI dysplasia in total PAEs metabolites high concentration group was 1.55 times (OR=1.55, 95% CI: 1.00-2.38) than in low concentration group. Conclusion Phthalates exposure may damage the executive function of preschool children.