The Benefit Risk Assessment of Consumption of Marine Species Based on Benefit-Risk Analysis for Foods (BRAFO)-tiered Approach / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the net health effect caused by the consumption of specific marine species based on Benefit-Risk Analysis for Foods (BRAFO)-tiered approach.</p><p><b>METHODS</b>Twenty species were collected from the Zhoushan Archipelago, China. Concentrations of n-3 long-chain polyunsaturated fatty acids, methyl mercury (MeHg), and dioxin-like compounds (DLCs) in the samples were analyzed for benefit risk assessment based on BRAFO-tiered approach.</p><p><b>RESULTS</b>Based on the BRAFO-tiered approach, reference scenario (no intake) and alternative scenario (intake of specific species of 200 g/week) were determined. The exposure to MeHg/DLCs via alternative scenario of all studied species did not exceed provisional tolerable weekly/monthly intake. However, the adult population with high DLCs exposure in China would significantly exceed the upper limit of DLCs via an additional alternative scenario of some species such as Auxis thazard. The results of deterministic computation showed that alternative scenario of all studied species generated clear net beneficial effects on death prevention and child IQ gain.</p><p><b>CONCLUSION</b>The alternative scenario of all studied species could be recommended to population with average DLCs exposure, and the reference scenario of species with relatively high DLCs concentration could be recommended to population exposed to high DLCs.</p>

An evaluation of genotoxicity and cytotoxicity of melamine in combination with cyanuric acid at three mass ratios / 生物医学与环境科学（英文）

Melamine in combination with cyanuric acid has been considered to be more toxic than either melamine or cyanuric acid alone. The objective of this study was designed to evaluate the combined genotoxicity and cytotoxicity of melamine (M) and cyanuric acid (C) at three mass ratios (1:1, 1:2, 2:1). MC (1:1), MC (1:2), and MC (2:1) were evaluated for their potential genotoxic risk, at gene level by Ames test, and at chromosomal level by micronucleus test. In order to evaluate cytotoxicity in HEK-293 cells, the MTT assay was included. Western blot was also employed to investigate the renal injury molecule-1 (Kim-1) expression in HEK-293 cells exposed to MC. Neither genotoxicity at gene level nor at chromosomal level was observed for MC (1:1), MC (1:2), and MC (2:1). Based on MTT assay, three ratios of MC at 82.5 and 165 µg/mL slightly inhibited viability of HEK-293 cells (P<0.05). MC (1:1) at 41.25 and 82.50 µg/mL could elevate the Kim-1 expression in HEK-293 cells.

Application of gas chromatography-mass spectrometry in analyzing pharmacokinetics and distribution of deltamethrin in miniature pig tissues / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To characterize the pharmacokinetics and distribution profiles of deltamethrin in miniature pig tissues by gas chromatography-mass spectrometry (GC-MS).</p><p><b>METHODS</b>Pharmacokinetics and distribution of deltamethrin in blood and tissues of 30 miniature pigs were studied by GC-MS after oral administration of deltamethrin (5 mg/kg bw). Data were processed by 3P97 software.</p><p><b>RESULTS</b>The serum deltamethrin level was significantly lower in tissues than in blood of miniature pigs. The AUC0-72 h, Cmax, of deltamethrin were 555.330 ± 316.987 ng h/mL and 17.861 ± 11.129 ng/mL, respectively. The Tmax, of deltamethrin was 6.004 ± 3.131 h.</p><p><b>CONCLUSION</b>The metabolism of deltamethrin in miniature pigs is fit for a one-compartment model with a weighting function of 1/C2. Deltamethrin is rapidly hydrolyzed and accumulated in miniature pig tissues.</p>

Antioxidant and antigenotoxic activity of bioactive extracts from corn tassel / 华中科技大学学报（医学）（英德文版）

This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts (CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant properties of the three bioactive components of CTTs were investigated by Ferric Reducing Antioxidant Property (FRAP) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assays. The activities of the extracts were determined by assessing the inhibition of mutagenicity of the direct-acting mutagen fenaminosulf, sodium azide, and indirect-acting mutagen 2-aminofluorene using the Ames test (strains TA98 and TA100). The results showed that the extraction rates of flavonoid, saponin, and polysaccharide from the dried corn tassels were 1.67%, 2.41% and 4.76% respectively. DPPH and FRAP assay strongly demonstrated that CTTs had antioxidant properties. CTTs at doses of 625, 1250 and 2500 μg per plate reduced 2-aminofluorene mutagenicity by 12.52%, 28.76% and 36.49% in Salmonella typhimurium TA98 strain assay respectively and by 10.98%, 25.27% and 37.83%, at the same doses in Salmonella typhimurium TA100 assay system, respectively. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay showed that the different concentrations of CTTs inhibited the proliferation of MGC80-3 cells in a dose-dependent manner (P<0.01). It is concluded that these integrated approaches to antioxidant and antigenotoxicity assessment may be useful to study corn tassel as a natural herbal material.

Antioxidant and antigenotoxic activity of bioactive extracts from corn tassel / 华中科技大学学报（医学）（英德文版）

This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts (CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant properties of the three bioactive components of CTTs were investigated by Ferric Reducing Antioxidant Property (FRAP) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assays. The activities of the extracts were determined by assessing the inhibition of mutagenicity of the direct-acting mutagen fenaminosulf, sodium azide, and indirect-acting mutagen 2-aminofluorene using the Ames test (strains TA98 and TA100). The results showed that the extraction rates of flavonoid, saponin, and polysaccharide from the dried corn tassels were 1.67%, 2.41% and 4.76% respectively. DPPH and FRAP assay strongly demonstrated that CTTs had antioxidant properties. CTTs at doses of 625, 1250 and 2500 μg per plate reduced 2-aminofluorene mutagenicity by 12.52%, 28.76% and 36.49% in Salmonella typhimurium TA98 strain assay respectively and by 10.98%, 25.27% and 37.83%, at the same doses in Salmonella typhimurium TA100 assay system, respectively. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay showed that the different concentrations of CTTs inhibited the proliferation of MGC80-3 cells in a dose-dependent manner (P<0.01). It is concluded that these integrated approaches to antioxidant and antigenotoxicity assessment may be useful to study corn tassel as a natural herbal material.

Dietary exposure of the Chinese population to acrylamide / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the current status of the acrylamide in the Chinese food supply, the dietary acrylamide exposure in the Chinese population and to estimate the public health risks of the current consumption.</p><p><b>METHODS</b>The acrylamide content in the total diet study (TDS) food samples was analyzed using an LC-MS/MS method. Based on the analytical results, the dietary exposure calculations were performed using a deterministic method, combining mean acrylamide concentrations from the food group composite with their associated food consumptions.</p><p><b>RESULTS</b>Acrylamide was detected in 43.7% of all samples collected and acrylamide concentration varied from ND to 526.6 µg/kg. The estimated dietary intakes of acrylamide among Chinese general population given as the mean and the 95th percentile (P95) were 0.286 and 0.490 µg•kg(-1) bw•day(-1), respectively. The margins of exposure (MOEs) for the population calculated using both benchmark dose lower confidence limit for a 10% extra risk of tumors in animals (BMDL10) 0.31 and 0.18 µg•kg(-1) bw•day(-1), were 1069 and 621 for the mean dietary exposure, and 633 and 367 for the high dietary exposure respectively.</p><p><b>CONCLUSION</b>These MOE values might indicate a human health concern on acrylamide for Chinese population. Efforts should continue to reduce acrylamide levels in food in order to reduce the dietary risks to the human health.</p>

Synergistic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and N-nitrosodiethylamine on cell malignant transformation / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The present paper aims to investigate the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and N-nitrosodiethylamine (DEN) on tumorigenesis and its potential mechanism.</p><p><b>METHODS</b>The potentials of TCDD and DEN in separation or in combination to induce malignant transformation were tested in Balb/c 3T3 cells by using a cell transformation assay method. The possible mechanism of observed effects was studied further by adding α-naphthoflavone (α-NF), a competitive binding agent of TCDD, to the Aryl hydrocarbon receptor (AhR) pathway. The mRNA expressions of Cyp1a1 and Cyp2a5 gene in Balb/c 3T3 cells treated by DEN and TCDD in separation or in combination with or without presence of α-NF were measured with fluorescence quantification RT-PCR technique.</p><p><b>RESULTS</b>The cell transformation frequency (TF) was significantly higher in case of induction with TCDD in combination with DEN, as compared to that with either TCDD or DEN alone. These effects were not inhibited via α-NF. The mRNA expression levels of both Cyp1a1 and Cyp2a5 were enhanced by TCDD treatment alone, but this inducible effect was blocked in cells treated by TCDD and DEN in combination.</p><p><b>CONCLUSION</b>TCDD and DEN had a significant synergistic effect on tumorigenesis when they were used in combination. AhR pathway may not be the key mechanism of this synergistic effect. Thus, it is necessary to further test the potential mechanism involved in cancer development.</p>

Fatty acid composition of edible marine fish in Zhoushan, Zhejiang province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the main fatty acids in edible marine fish from Zhoushan, Zhejiang province.</p><p><b>METHODS</b>From September to October 2011, a total of 186 edible marine fish (31 species,6 individual fishes/species) were collected in local markets. Total lipids of edible part were extracted by Folch's method and fatty acids were separated and quantified by gas chromatographic after the homogenization of edible part. The differences of composition of n-6 polyunsaturated fatty acid (n-6 PUFA), n-3 polyunsaturated fatty acid (n-3 PUFA),saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) among fishes were analyzed.</p><p><b>RESULTS</b>Among the 31 fishes, total lipids were highest in Auxis thazard ((13.2 ± 1.2)g/100 g edible part) and lowest in Thamnaconus modestus ((0.6 ± 0.1)g/100 g edible part). Total n-6 PUFA were highest in Mugil cephalus ((875.7 ± 506.4)mg/100 g edible part) and lowest in Seriola quinqueradiata((2.1 ± 1.9)mg/100 g edible part). Total n-3 PUFA were highest in Auxis thazard ((2623.8 ± 426.1)mg/100 g edible part) and lowest in Scoliodon sorrakowah ((82.0 ± 13.9)mg/100 g edible part). SFA were highest in Trachinotus ovatus((3014.9 ± 379.0)mg/100 g edible part) and lowest in Seriola quinqueradiata ((89.7 ± 5.8)mg/100 g edible part). MUFA were highest in Coilia nasus ((3335.7 ± 383.5)mg/100 g edible part) and lowest in Thamnaconus modestus ((32.1 ± 16.9)mg/100 g edible part).</p><p><b>CONCLUSION</b>There were significant differences of composition of total lipids and of fatty acids among 31 edible marine fish species from Zhoushan.</p>

The human body burden of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in residents' human breast milk from Beijing in 2007 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human breast milk from Beijing residents, and evaluate the human body burden of PCDD/Fs and dl-PCBs of general population.</p><p><b>METHODS</b>A total of 110 human milk samples were collected from 11 regions in Beijing in 2007. After 11 pooled samples were made, concentrations of PCDD/Fs and dl-PCBs in breast milk pooled samples were measured by a high resolution gas chromatography - high resolution mass spectrometry (HRCG-HRMS) with isotope dilution.</p><p><b>RESULTS</b>For congeners of PCDD/Fs and dl-PCBs in human breast milk from Beijing, the highest content of congeners was octachlorodibenzo-p-dioxin (OCDD), polychlorinated biphenyl (PCB)-118, and PCB-105 with the median of 20.6 pg/g fat, 4.07 ng/g fat and 1.63 ng/g fat, respectively. The concentration median of total dioxins in 11 pooled human milk samples from Beijing was 7.4 pg TEQ/g fat. The highest was 13.5 pg TEQ/g fat from Tongzhou, and the lowest was 4.3 pg TEQ/g fat from Pinggu.</p><p><b>CONCLUSION</b>The contamination level of PCDD/Fs and dl-PCBs in human milk from Beijing is relatively low. However, with the rapid industrialization in China, the human body burden of PCDD/Fs and dl-PCBs will be likely to rise. Thus, further studies should be conducted to continuously monitor the trend of contamination level.</p>

Prevalence and antibiogram distribution of Salmonella isolated from broiler production and processing course in four provinces, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.</p><p><b>METHODS</b>Five large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.</p><p><b>RESULTS</b>In total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.</p><p><b>CONCLUSION</b>Our findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.</p>

Development of an enzyme-linked immunosorbent assay for determination of the furaltadone etabolite, 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) in animal tissues / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) residues released from protein bound AMOZ in animal tissues.</p><p><b>METHODS</b>Polyclonal and monoclonal antibodies were produced in this study. A rapid, sensitive, and specific competitive direct enzyme-linked immunosorbent assay (cdELISA) was developed.</p><p><b>RESULTS</b>Rabbit polyclonal antibodies were used in the optimized cdELISA method, and exhibited negligible cross-reactivity with other compounds structurally related to AMOZ. The IC(50) of the polyclonal antibody was 0.16 ng/mL. The method limit of detection in four different types of animal and fish tissues was less than 0.06 μg/kg. Recoveries ranged from 80% to 120% for fortified samples with the coefficient of variation values less than 15%. The results of the cdELISA method were in good agreement with the results from an established liquid chromatography-tandem mass spectrometry confirmatory method used for AMOZ residues.</p><p><b>CONCLUSION</b>The cdELISA method developed in the present study is a convenient practical tool for screening large numbers of animal and fish tissue samples for the the detection of released protein bound AMOZ residues.</p>

Polybrominated diphenyl ethers load in human serum of Taiyuan city in 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>This study was conducted to characterize polybrominated diphenyl ethers (PBDEs) load in human serum of Taiyuan city in 2010.</p><p><b>METHODS</b>A total of 42 blood samples were collected in Taiyuan city, 2010. Solid-phase extraction (SPE)-gas chromatography-negative chemical ionization-mass spectrometry method was used to measure the concentration of brominated diphenyl ethers (BDE)-17, BDE-28, BDE-47, BDE-66, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183 and BDE-209 and ΣPBDEs was calculated.</p><p><b>RESULTS</b>Of the tested serum samples, ΣPBDEs ranged from 2.09 to 66.74 ng/g of lipid weight (lw), the median and mean was 6.32 ng/g lw and 9.84 ng/g lw, respectively. BDE-209 was the main source of ΣPBDEs and its concentration ranged from no detection to 64.99 ng/g lw, the median was 4.11 ng/g lw, accounting for 67.6% of ΣPBDEs. Second source was BDE-153 and its concentration ranged from 0.29 to 4.92 ng/g lw, the median was 0.62 ng/g lw accounting for 10.1% of ΣPBDEs.</p><p><b>CONCLUSION</b>The overall load of PBDEs in the serum of local residents was low in 2010.</p>

Establishment of database for food classification and coding in Chinese dietary exposure assessment / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish the basis for Chinese dietary exposure assessment database by classifying and coding the data from the national dietary survey and pollutant surveillance.</p><p><b>METHODS</b>The method, which combined CODEX food classifying and coding of Codex Alimentarius Commission (CAC) with Chinese food classification of food composition table, was applied to classify and code the data of 1 810 703 Chinese dietary consumption and 487 819 pollutant surveillance. The coding system was according to the first two letters of the respective food group that represent the type or source of foods, the last four digits represent the serial number of the food in the CAC food classification. If the foods can be found in CAC food code system, its original food code is used. The new codes corresponding with the foods which are not exist in CAC food code system, is added according to CAC coding methods.</p><p><b>RESULTS</b>Dietary consumption data were divided into 6 major categories, 19 types, 75 groups, the agricultural products of pollutant surveillance corresponding to 499 codes. Comparing with CAC food coding system, Chinese dietary consumption data have added F (candy snacks) and G (beverages) 2 major categories, 4 types, 33 groups, 302 new codes. The additional groups most were the processing food groups with Chinese characteristics, such as canned, beverages, candy, meat products.</p><p><b>CONCLUSION</b>The foundation of data communication to dietary exposure assessment has been established, and the connection of Chinese food classifying and coding with CAC data have been achieved.</p>

Smoking status or age impact on urinary 8-hydroxy-2'-deoxyguanosine in electrical and electronic equipment waste dismantling workers / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the smoking or age impact on occupational workers in electrical and electronic equipment waste (e-waste) dismantling procedure, using 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in the urine as a biomarker for oxidative damage to DNA.</p><p><b>METHODS</b>The pre-workshift and post-workshift urinary samples of 64 male workers in e-waste dismantling procedure were detected by solid-phase extraction-high performance liquid chromatography-electrochemical detector (SPE-HPLC-ECD). The data were statistically analyzed by two factors, age or smoking status.</p><p><b>RESULTS</b>The 8-OHdG levels in non-smokers' urines (n = 42) were higher than those in smokers' urines (n = 22). The levels in pre-workshift urines were detected at (8.25 +/- 4.23) micromol/mol creatinine in non-smokers, while the values were (5.44 +/- 1.18) micromol/mol in smokers. And, the levels in post-workshift were detected at (43.12 +/- 16.19) micromol/mol creatinine in non-smokers, while the values were (14.82 +/- 2.51) micromol/mol in smokers. The 8-OHdG levels in pre-workshift urines were not different between non-smokers and smokers (t = -0.81, P = 0.42), however after 1 day exposure, urinary 8-OHdG levels were significantly increased in non-smokers than those in smokers (t = - 2.33, P < 0.05). On the other hand, the subjects were divided into five groups according to their age. The 8-OHdG levels in pre-workshift urines were (1.86 +/- 0.66), (3.57 +/- 0.54), (8.12 +/- 4.10), (11.39 +/- 3.70) micromol/mol creatinine in < 20 years group (n = 6), 20 -years group (n = 22), 30 - years group ( n = 23), 40 - 49 years group (n = 11) respectively. No effect of age was found on the pre-workshift urinary 8-OHdG levels (F = 0.98, t = 0.41). However, it was found that the post-workshift urinary 8-OHdG levels increased along with the e-waste workers' age (F = 4.81, P = 0.03), and they were (4.19 +/- 2.85), (19.89 +/- 5.26), (28.89 +/- 14.61), (34.94 +/- 12.50) micromol/mol creatinine in < 20 years group, 20 - years group, 30 - years group, 40 - 49 years group respectively.</p><p><b>CONCLUSION</b>The urinary 8-OHdG levels in the e-waste dismantling workers might be inhibited by smoking status. The post-workshift urinary 8-OHdG levels increased along with the e-waste workers' age.</p>

An improved BALB/c 3T3 cell transformation assay and its application in the cocarcinogenesis study / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To improve the protocol of BALB/c 3T3 cell transformation assay, and apply it to the cocarcinogenesis study.</p><p><b>METHOD</b>Appropriate serum concentration, culture media and method of administration were selected by testing their effects on the growth and transformation of BALB/c 3T3 cells. The co-carcinogenic activity between diethylnitrosamine (DEN) and microcystin-LR (MC-LR) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were examined using the improved cell transformation assay. The malignant characteristics of transformed cells were verified by neoplasia in SCID mice.</p><p><b>RESULTS</b>There were strong co-carcinogenic activity between DEN and TCDD. On the contrary, although MC-LR has strong ability to induce cell transformation, the effect was markely inhibited by DEN. The transformed cells show some malignant characteristics.</p><p><b>CONCLUSION</b>The improved BALB/c 3T3 cell transformation assay is reliable and time-saving, and can be efficiently used in the study of cocarcinogenesis.</p>

Assessment on dietary melamine exposure from tainted infant formula / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To estimate the dietary melamine exposure in Chinese infants and young children from the consumption of melamine adulterated Sanlu infant formula.</p><p><b>METHODS</b>Four age groups of infants and young children (3, 6, 12, and 24 months) were chosen as the assessed subjects and the maximum amount of infant formula consumption was estimated based on the recommended usage level in the package insert of Sanlu infant formula and other brands. Melamine was analyzed in 111 Sanlu infant formula samples collected from the markets in Beijing and Gansu province using the LC-MS-MS with a limit of quantification of 0.05 mg/kg. Four levels of melamine concentration were chosen to estimate the dietary intakes, including the mean, median, 90th percentile, and maximum.</p><p><b>RESULTS</b>The infants of 3 months had the highest intake of melamine, and with the increase of the age (month), the intake decreased. Based on the median melamine concentration (1,000 mg/kg) as an example, the melamine intakes for the infants of 3, 6, 12, and 24 months were 23.4, 21.4, 15.0, and 8.6 mg/kg bw/d, respectively.</p><p><b>CONCLUSION</b>Dietary melamine intakes from tainted Sanlu infant formula significantly exceeded the TDI level (0.2 mg/kg bw/d) recommended by the WHO Expert Meeting in 2008. However, the present assessment has some limitations including the poor representative samples, the varied melamine concentrations in the adulterated Sanlu infant formula, and other brand infant formula possibly consumed by these infants.</p>

A survey on occurrence of melamine and its analogues in tainted infant formula in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the occurrence and concentrations of melamine and its analogues in tainted infant formula and to identify the etiologic factors for the urinary stones epidemic in infants and young children in China in 2008.</p><p><b>METHODS</b>Sanlu infant formula samples were collected from families of the affected children in Gansu province, and markets in Gansu and Hebei provinces and Beijing city. Melamine and its analogues, including cyanuric acid, ammeline, and ammelide were measured by gas chromatography/tandem mass spectrometry.</p><p><b>RESULTS</b>High prevalence and concentrations of melamine were found in Sanlu infant formula samples, with low concentrations of cyanuric acid, ammeline and ammelide. Melamine were detected in 87 out of 111 Sanlu infant formula samples with a range of 118 to 4,700 mg/kg.</p><p><b>CONCLUSION</b>The results provide strong evidence for melamine as the etiological factor for the urinary stones epidemic in infants and young children in China in 2008.</p>

Simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry (GC-MS/MS).</p><p><b>METHODS</b>Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard.</p><p><b>RESULTS</b>The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the four compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3.</p><p><b>CONCLUSION</b>This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.</p>

Detection of genetically modified crops by combination of multiplex PCR and low-density DNA microarray / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray.</p><p><b>METHODS</b>Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified (GM) soybean. Seventeen capture probes (PCR products) and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean (GTS40-3-2), maize (Mon810, Nk603, GA21), canola (T45, MS1/RF1), and rice (SCK) in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean (Roundup Ready GTS40-3-2) and canola (MS1/RF1).</p><p><b>RESULTS</b>A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity.</p><p><b>CONCLUSION</b>A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.</p>

National continuous monitoring on the content of lead in preserved eggs from 2000 to 2006 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the pollution level and development trend of lead in the preserved egg in our country.</p><p><b>METHODS</b>By the national food contamination monitoring system and under the strict analysis quality control, the content of lead in the preserved eggs was analyzed according to the national standard method (GB/T 5009.12-2003) in fourteen provinces from 2000 to 2006.</p><p><b>RESULTS</b>All 1358 data on contents of lead in the preserved eggs were obtained during seven years, the total average was 1.782 mg/kg, the maximum was 334.0 mg/kg, P90 was 3.50 mg/kg, P95 was 7.397 mg/kg and P97.5 was 12.01 mg/kg, all exceeded 2 mg/kg of the national limit standard, and the rate of violated samples exceeded 10.0%. Analyzing from time, contents of lead in the preserved eggs were depressive from 2.994 mg/kg to 1.138 mg/kg year after year.</p><p><b>CONCLUSION</b>The lead contamination in preserved eggs was serious in whole country. It shows that the continuous work of monitoring and forewarning should be carried out to make the contamination of lead in preserved eggs to reduce year by year.</p>