[Determination of 21 organophosphate esters and their metabolites in drinking water by automatic solid phase extraction-liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for simultaneous determination of 21 organophosphate esters(OPEs) and their metabolites in drinking water by automatic solid phase extraction-liquid chromatography-tandem mass spectrometry. METHODS: The drinking water was purified by automatic solid phase extraction with HLB column, eluted by methanol, determined by liquid chromatography tandem mass spectrometry with ACQUITY UPLC BEH(100 mm×2.1mm, 1.7 µm) column, and quantified by internal standard method. RESULTS: The optimized method could simultaneously detect 21 organophosphate esters and their metabolites in drinking water. The detection limit was 0.01-0.24 ng/L, the quantitation limit was 0.03-0.77 ng/L. The recovery range was 57.6%-121.2% and the relative standard deviation is 1.2%-11.1% when the concentration was 0.8-20 ng/L. Senventeen tap water and 30 packaged drinking water collected by the supermarket were measured. The ΣOPEs range was 16.8-177 ng/L, and the Σdi-OPEs range was 0.328-16.3ng/L, indicating the exposure risk of organophosphates and their metabolites in water. CONCLUSION: The pretreatment of the method is simple, automatic and sensitive, and is suitable for simultaneous high-throughput determination of organophosphate esters and their metabolites in large quantities of drinking water.

[Rapid confirmation method of food poisoning caused by Bacillus cereus cereulide in rice and flour products].

OBJECTIVE: To develop a method for rapid determination of Bacillus cereus cereulide in rice and flour products by ultra-performance liquid chromatography-tandem mass spectrometry, providing emergency measures for food poisoning caused by cereulide. METHODS: Single rice and flour samples were extracted with acetonitrile aqueous solution, salting out, after centrifuged and filmed, the organic phase was directly determined. The complex matrix samples fried rice and noodles were extracted with acetonitrile aqueous solution, cleaned up with HLB column, a ACQUITY UPLC Peptide BEH C_(18) 300Å column(2.1 mm×100 mm, 1.7 µm)was used for liquid chromatography separation, multiple reaction monitoring(MRM) mode was used for detection in electrospray ionization with positive ion mode, and quantified by the solvent standard curve method. RESULTS: At the spiked level of 0.5, 1.0 and 5.0 µg/kg, the recoveries of cereulide in negative steamed rice, steamed bread and noodles samples were 87.4%-98.3%, and the relative standard deviations were 1.4%-4.2%. At the spiking levels of 1.0, 2.0 and 5.0 µg/kg, the recoveries of cereulide in the negative samples such as fried steamed rice and fried noodles were 89.5%-99.3% with the relative standard deviations of 1.1%-7.5%(n=6). The detection limit of cereulide was 0.2-0.3 µg/kg, and the quantification limit was 0.5-1.0 µg/kg. The established method was applied to the detection of the actual samples causing food poisoning in a certain place in Beijing. The content of cereulide in poisoned food samples was 1287-7398 µg/kg, the content of cereulide in two raw materials cold noodles was 0.4 and 9.4 µg/kg. CONCLUSION: The method is simple, rapid, high sensitivity and accurate, and can realize the rapid treatment of food poisoning caused by cereulide.

A case-control study of urinary concentrations of bisphenol A, bisphenol F, and bisphenol S and the risk of papillary thyroid cancer.

The incidence of thyroid cancer (TC), especially papillary thyroid cancer (PTC), has dramatically increased globally. Whereas some endocrine disruptors have been linked to neoplastic processes, the associations between human exposure to bisphenol analogs and the risk of TC remain unclear. This present case-control study examined the associations between the urinary concentrations of bisphenol A (BPA) and other bisphenols, namely bisphenol F (BPF) and bisphenol S (BPS), and the risk of PTC. After adjusting for confounders and creatinine standardization, significantly positive associations were observed for BPF (odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.27-2.54), but negative associations observed for BPA (OR = 0.38, 95% CI = 0.19-0.77) and BPS (OR = 0.63, 95% CI = 0.43-0.93), in the total population. However, after stratification by age and smoking, statistical significance was retained only in non-smoking women, suggesting the adverse effects of BPF exposure on PTC risk, especially in women. These findings require replication and confirmation in further research.

Human exposure to a mixture of endocrine disruptors and serum levels of thyroid hormones: A cross-sectional study.

Exposure to endocrine disruptors (EDCs) could disrupt thyroid hormone homeostasis. However, human epidemiological studies reported inconsistent observations, and scarce information on the effect of a mixture of chemicals. The aim of the present study was to examine the associations of multiple chemicals with thyroid hormones among adults from China. We measured serum levels of thyroid hormones and urinary levels of 11 EDCs, including six phthalate metabolites, bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS), perchlorate, and thiocyanate among 177 healthy adults without occupational exposure. Associations of multiple urinary analytes with serum thyroid hormones were examined by performing general linear regression analysis and bayesian kernal machine regression analysis. These EDCs were detected in almost all samples. After adjusting for various covariates, we observed only BPF significantly associated with total thyroxin (TT4) (ß=-0.27, 95% confidence interval (CI) [-0.41, -0.14]), total triiodothyronine (TT3) (ß=-0.02 95% CI [-0.03, -0.01]), free T4 (fT4) (ß=-0.02, 95% CI [-0.03, -0.01]), and free T3 (fT3) (ß=-0.04, 95% CI [-0.07, -0.01]), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and monoethyl phthalate (MEP) positively associated with TT4 (ß=0.24, 95% CI [0.01, 0.48]) and fT4 (ß=0.02, 95% CI [0.01, 0.04]), respectively. Moreover, we observed significant dose-response relationships between TT4 and the mixture of 11 EDCs, and BPF was the main contributor to the mixture effect, suggesting the priority of potential effect of BPF on disrupting thyroid function under a real scenario of human exposure to multiple EDCs. Our findings supported the hypothesis that human exposure to low levels of EDCs could alter thyroid hormones homeostasis among non-occupational healthy adults.

[Clinical features of children and their family members with family clusters of SARS-CoV-2 Omicron variant infection in Shanghai, China: an analysis of 380 cases]. / 上海380例家庭聚集性感染Omicronå˜å¼‚æ ªçš„å„¿ç«¥åŠå ¶å®¶å±žä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical features and prognosis of children and their family members with family clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection under the admission mode of parent-child ward. METHODS: A retrospective analysis was performed on the medical data of 190 children and 190 family members with SARS-CoV-2 Omicron variant infection who were admitted to Shanghai Sixth People's Hospital, the designated hospital for coronavirus disease 2019 (COVID-19), April 8 to May 10, 2022. RESULTS: Both the child and adult groups were mainly mild COVID-19, and the proportion of mild cases in the child group was higher than that in the adult group (P<0.05). Respiratory symptoms were the main clinical manifestations in both groups. Compared with the adult group, the child group had higher incidence rates of fever, abdominal pain, diarrhea, and wheezing (P<0.05) and lower incidence rates of nasal obstruction, runny nose, cough, dry throat, throat itching, and throat pain (P<0.05). Compared with the child group, the adult group had higher rates of use of Chinese patent drugs, traditional Chinese medicine decoction, recombinant interferon spray, cough-relieving and phlegm-eliminating drugs, and nirmatrelvir/ritonavir tablets (P<0.05). Compared with the adult group, the child group had a lower vaccination rate of SARS-CoV-2 vaccine (30.5% vs 71.1%, P<0.001) and a shorter duration of positive SARS-CoV-2 nucleic acid (P<0.05). The patients with mild COVID-19 had a shorter duration of positive SARS-CoV-2 nucleic acid than those with common COVID-19 in both groups (P<0.05). The patients with underlying diseases had a longer duration of positive SARS-CoV-2 nucleic acid than those without such diseases in both groups (P<0.05). CONCLUSIONS: Both children and adults with family clusters of SARS-CoV-2 Omicron variant infection manifest mainly mild COVID-19. Despite lower vaccination rate of SARS-CoV-2 vaccine in children, they have rapid disease recovery, with a shorter duration of positive SARS-CoV-2 nucleic acid than adults, under the admission mode of parent-child ward.

[Determination of organophosphorus pesticide residues in milk of cows and sheep by ultra-high-performance liquid chromatography- tandem mass spectrometry combined with passing type purification method].

OBJECTIVE: A method for the rapid determination of dichlorvos, trichlorfon, fenthion, fenthion-sulfone, fenthion-sulfoxide, fenthion-oxon, fenthion-oxon-sulfone, fenthion-oxon-sulfoxide, phoxim, propetamphos, malathion, diazinon and coumaphos 13 common organophosphorus pesticides and their metabolites poison residues in milk of cows and sheep by ultra-high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with passing type solid phase extraction(SPE) purification was developed. METHODS: After centrifugation at 4 ℃, the milk was purified by passing type SPE with acetonitrile precipitating protein and determined by UPLC-MS/MS in electrospray positive ion mode(ESI+) and multi-reaction monitoring scanning(MRM), external standard method for quantitative analysis with matrix matching standard curve. RESULTS: The recoveries of 13 target compounds were between 81.5% and 107.5% and relative standard deviation was between 1.24% and 6.23% at three spiked levels of 5, 10, 20 µg/L. The detection limits of 13 target compounds were between 0.015 and 0.15 µg/L, and the quantitative limits were between 0.05 and 0.50 µg/L. No organophosphorus pesticide residues were detected in 20 samples of cows and sheep milk. CONCLUSION: The method has the advantages of good linear independence, low detection limit, high precision and accuracy, and can be used for daily monitoring of milk and related products.

A simple method for simultaneous determination of organophosphate esters and their diester metabolites in dairy products and human milk by using solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry.

Organophosphate esters (OPEs) and their diester metabolites have been frequently found in various environmental matrices and regarded as emerging environmental pollutants, whereas data on their occurrence in foods and human matrices are still limited. In this study, a novel and simple procedure was developed to simultaneously determine 14 OPEs and 6 diester metabolites in dairy products and human milk. After enzymatic hydrolysis by ß-glucuronidase/arylsulfatase, a freeze-dried milk sample was extracted with acetonitrile and purified by solid-phase extraction. Subsequently, all target compounds were determined by HPLC-ESI-MS/MS. Linearity, limits of detection (LODs), recovery, precision, and matrix effects of the proposed methodology were validated, and the parameters of HPLC-ESI-MS/MS were optimized. LODs for OPEs and their diester metabolites were from 0.001 to 0.02 ng/mL, and limits of quantification (LOQs) were 0.01-0.3 ng/mL. Average recoveries at two spiked levels ranged between 67.3 and 121%, with relative standard deviation lower than 20.7%. A test for matrix effects showed that most analytes presented signal suppression, and isotopically labeled ISs were essential for compensating for the matrix effects. Finally, OPEs and their metabolites both showed high detecting frequencies in real samples, which indicated that these emerging pollutants were ubiquitous in foods and the human body, and the impact of the diester metabolites on population exposure must be included in exposure assessment.

Organophosphate esters and their diester metabolites in infant formulas and baby supplementary foods collected in Beijing, China: Occurrence and the implications for infant exposure.

Organophosphate esters (OPEs) have been extensively used as flame retardants and/or plasticizers and they found to be ubiquitous in various environmental matrices along with the gradual phase-out of brominated flame retardants (BFRs). Moreover, their main metabolites, organophosphate di-esters (di-OPEs), were also frequently detected. However, few studies focused on the occurrence of OPEs and di-OPEs in foods. In this study, fourteen OPEs and five di-OPEs were measured in infant formula and baby supplementary food (BSF) collected in Beijing, China. Most OPEs and di-OPEs presented high detection frequencies, which indicated their ubiquity in baby foods. The concentrations of ∑14OPEs in the 75 infant formula samples ranged from 0.79 to 159 ng/g, with a median of 23.2 ng/g, and in which triphenyl phosphate (TPhP) was the most abundant compound. The concentrations of ∑14OPEs in the 32 BSF samples were 4.42-115 ng/g (median: 19.5 ng/g), and tri(3-chloropropyl) phosphate (TCIPP) was predominant. Moreover, no significant difference was observed between OPE levels in infant formula and BSF. The median concentrations of Σ5di-OPEs in infant formula and BSF were 3.39 and 5.43 ng/g, respectively. However, no significantly correlation was observed between concentrations of di-OPEs and their parent compounds, which indicated they have different sources. The median estimated dietary intakes (EDIs) of the ∑14OPEs were from 165 to 383 ng/kg bodyweight (bw)/day for infants via infant formula feeding, and were from 429 to 470 ng/kg bw/day via BSF feeding. A comparison to corresponding reference dose (RfD) suggested that dietary intakes of OPEs to Beijing infants via formula/BSF consumption were still unable to cause significant health concerns. However, EDIs of OPEs for infants were found to be significantly higher than that for Chinese adults, and dietary intake might be the predominant OPE intake pathway for infants. To our knowledge, this is the first study to investigate OPEs and their metabolites in baby foods.

Ambient temperature structures the gut microbiota of zebrafish to impact the response to radioactive pollution.

Potential nuclear accidents propel serious environmental pollution, and the resultant radionuclide release devastates severely the environment severely and threatens aquatic organism survival. Likewise, ongoing climate change coupled with the gradual increase in global surface temperatures can also adversely impact the aquatic ecosystems. In the present study, we preconditioned zebrafish (Danio rerio) at three different temperatures (18 °C, 26 °C and 34 °C) to investigate the effects of a temperature profile on their radiosensitivity (exposure to 20 Gy of gamma rays) to identify the potential biochemical mechanism responsible for influencing radiosensitivity. We found that preconditioning of zebrafish at different temperatures moulded specific gut microbiota configurations and impacted hepatic glycometabolism and sensitivity to subsequent radiation. Following antibiotic treatment to reduce gut bacteria, these observed differences in the expression of hepatic glycometabolism-related genes and radiation-induced intestinal toxicity were minimal, supporting the hypothesis that the gut bacteria reshaped by different ambient temperatures might be the key modulators of hepatic functions and radiosensitivity in zebrafish. Together, our findings provide novel insights into the connection of radiation injuries with temperature alterations in fish, and suggest that maintaining the stability of gram-positive bacteria may be efficacious to protect aquatic organisms against short or long-term radioactive contamination in the context of global climate change.

Occurrence and Dietary Intake of Organophosphate Esters via Animal-Origin Food Consumption in China: Results of a Chinese Total Diet Study.

Although diet is regarded as a major exposure source of organophosphate esters (OPEs), the dietary survey of OPEs in China has been limited. Based on the sixth Chinese Total Diet Study (TDS) conducted during 2016-2019 in 24 of 34 provinces in China, 14 OPEs were detected in 96 food composites from four animal-origin food categories. Twelve OPEs were detected in more than 80% of the samples and 2-ethylhexyl diphenyl phosphate (EHDPP) presented the highest median concentration (1.63 ng/g wet weight (ww)). The most contaminated food composite was meat, with a median ∑14OPEs of 13.6 ng/g ww, followed by aquatic food (11.5 ng/g ww), egg (7.63 ng/g ww), and milk (3.51 ng/g ww). The contribution of the meat group was close to or even greater than 50% in the estimated dietary intake (EDI) of OPEs. The average (range) EDI of the ∑14OPEs via animal food consumption for a Chinese "standard man" was 34.4 (6.18-73.3) ng/kg bodyweight (bw)/day. The geographical distribution showed higher EDI in southern coastal provinces compared to the northern inland provinces. Nevertheless, the highest EDI of ∑14OPEs from animal food was still more than 10 times lower than the reference dose. This is the first national survey of OPEs in foods from China.

Low-Intensity Exercise Modulates Gut Microbiota to Fight Against Radiation-Induced Gut Toxicity in Mouse Models.

Radiation-induced gastrointestinal (GI) tract toxicity halts radiotherapy and degrades the prognosis of cancer patients. Physical activity defined as "any bodily movement produced by skeletal muscle that requires energy expenditure" is a beneficial lifestyle modification for health. Here, we investigate whether walking, a low-intensity form of exercise, could alleviate intestinal radiation injury. Short-term (15 days) walking protected against radiation-induced GI tract toxicity in both male and female mice, as judged by longer colons, denser intestinal villi, more goblet cells, and lower expression of inflammation-related genes in the small intestines. High-throughput sequencing and untargeted metabolomics analysis showed that walking restructured the gut microbiota configuration, such as elevated Akkermansia muciniphila, and reprogramed the gut metabolome of irradiated mice. Deletion of gut flora erased the radioprotection of walking, and the abdomen local irradiated recipients who received fecal microbiome from donors with walking treatment exhibited milder intestinal toxicity. Oral gavage of A. muciniphila mitigated the radiation-induced GI tract injury. Importantly, walking did not change the tumor growth after radiotherapy. Together, our findings provide novel insights into walking and underpin that walking is a safe and effective form to protect against GI syndrome of patients with radiotherapy without financial burden in a preclinical setting.

Identification of odor biomarkers in irradiation injury urine based on headspace SPME-GC-MS.

PURPOSE: The threat of population exposure to ionizing radiation is increasing rapidly worldwide. Such exposure, especially at high-dose, is known to cause acute radiation syndrome (ARS). Hence, it is necessary to develop specific and sensitive biomarkers to accurately diagnose radiation injury and evaluate medical countermeasures. MATERIALS AND METHODS: Caenorhabditis elegans (C. elegans), a model organism with a fine and sound olfactory system, was used to examine the odor of urine samples collected from irradiation-injured rats, and compared with those from un-irradiated control rats to investigate the 'special odor' of radiation injury. Subsequently, headspace SPME-GC-MS was applied for non-targeted metabolomic analysis of volatile organic compounds (VOCs) in urine, with the aim to discover changes of small molecule metabolites and identify odor biomarkers of irradiation injury. RESULTS: C. elegans showed significant attraction to the urine of total body irradiation (TBI) rats compared with control rats, indicating that irradiation injury can emit 'special odor' and the metabolites in urine VOCs were changed. Using metabolomics based on headspace SPME-GC-MS for metabolic profiles analysis, we screened 63 differentially expressed metabolites. Among them, 10 metabolites including p-Cresol with excellent diagnostic ability were identified as odor biomarkers according to receiver operating characteristic (ROC) curve analysis. CONCLUSIONS: This study confirmed the 'special odor' induced by irradiation injury, and identified biomarkers through urine VOCs analysis for the first time, which can provide a novel approach and insight to evaluate irradiation injury noninvasively, accurately and conveniently.[Figure: see text].

[Determination of furan in canned foods and packaged beverages by headspace gas chromatography-mass spectrometry].

OBJECTIVE: A headspace gas chromatography-mass spectrometry(HS-GC-MS) method for the analysis of furan in canned foods and packaged beverages was established. METHODS: The furan was extracted from the samples by headspace method. D_4-furan was used as internal standard and separated on a HP-Plot Q(30 m×0.32 mm, 20 µm) column. The results were qualitative and quantitative by gas chromatography-mass spectrometry. RESULTS: The linear range of this method was 2.0-200.0 ng, and the regression equation of the working curve was y=1.14x +0.116(r~2=0.999). The recoveries were 86.3%-96.2% with the relative standard deviations(RSDs) less than 10%(n=6). The limit of quantification of furan was 1.0 ng. Through the detection of 59 samples, it was found that the common canned food and hard packaged drinks were commonly contaminated with furan, and the concentration of furan in coffee, milk tea, canned fish and other products were relatively high, with a maximum value of 153.99 ng. CONCLUSION: The method is simple, rapid, accurate and reliable, and could be used for the detection of furan in the two kinds of food.

Rapid determination of 13 organophosphorus flame retardants in milk by using modified quick, easy, cheap, effective, rugged, and safe technique, solid-phase extraction, and HPLC-MS/MS.

Organophosphorus flame retardants are a class of widely used plasticizers and flame retardants. In this study, an analytical methodology for the simultaneous determination of 13 organophosphorus flame retardants in milk was developed by using high-performance liquid chromatography-tandem mass spectrometry in combination with a modified quick, easy, cheap, effective, rugged, and safe technique and solid-phase extraction. The experimental parameters of the sample purification procedure and high-performance liquid chromatography-tandem mass spectrometry were optimized. The developed method was validated in terms of linearity, limits of detection, recovery, and precision. The method showed a linear response in the 1-100 ng/mL concentration range and the limits of detection ranged from 0.001 to 0.3 ng/mL. The mean recoveries for most organophosphorus flame retardants were in the ranges of 75.0-115.8% (spiked at 2.5 ng/mL) and 76.7-124.8% (spiked at 25 ng/mL), with relative standard deviations of <13.09%. The developed methodology was successfully applied to the analysis of nine human milk samples and nine commercial cow milk samples. Eleven organophosphorus flame retardants were detected in the human milk samples, with median concentrations that ranged from lower than the limit of detection to 1.47 ng/mL, and only nine organophosphorus flame retardants were detected in cow milk samples, with median levels of <0.32 ng/mL.

Exosomes are involved in total body irradiation-induced intestinal injury in mice.

Ionizing radiation-induced intestinal injury is a catastrophic complication in patients receiving radiotherapy. Circulating exosomes from patients undergoing radiotherapy can mediate communication between cells and facilitate a variety of pathological processes in vivo, but its effects on ionizing radiation-induced intestinal damage are undetermined. In this study we investigated the roles of exosomes during total body irradiation (TBI)-induced intestinal injury in vivo and in vitro. We isolated exosomes from serum of donor mice 24 h after lethal dose (9 Gy) TBI (Exo-IR-24h), then intravenously injected the exosomes into receipt mice, and found that Exo-IR-24h injection not only exacerbated 9 Gy TBI-induced lethality and weight loss, but also promoted crypt-villus structural and functional injury of the small intestine in receipt mice. Moreover, Exo-IR-24h injection significantly enhanced the apoptosis and DNA damage of small intestine in receipt mice following TBI exposure. In murine intestinal epithelial MODE-K cells, treatment with Exo-IR-24h significantly promoted 4 Gy ionizing radiation-induced apoptosis, resulting in decreased cell vitality. We further demonstrated that Exo-IR-24h promoted the IR-induced injury in receipt mice partially through its DNA damage-promoting effects and attenuating Nrf2 antioxidant response in irradiated MODE-K cells. In addition, TBI-related miRNAs and their targets in the exosomes of mice were enriched functionally using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Finally, injection of GW4869 (an inhibitor of exosome biogenesis and release, 1.25 mg·kg-1·d-1, ip, for 5 consecutive days starting 3 days before radiation exposure) was able to rescue mice against 9 Gy TBI-induced lethality and intestinal damage. Collectively, this study reveals that exosomes are involved in TBI-induced intestinal injury in mice and provides a new target to protect patients against irradiation-induced intestinal injury during radiotherapy.

Gut Microbiota-Derived PGF2α Fights against Radiation-Induced Lung Toxicity through the MAPK/NF-κB Pathway.

Radiation pneumonia is a common and intractable side effect associated with radiotherapy for chest cancer and involves oxidative stress damage and inflammation, prematurely halting the remedy and reducing the life quality of patients. However, the therapeutic options for the complication have yielded disappointing results in clinical application. Here, we report an effective avenue for fighting against radiation pneumonia. Faecal microbiota transplantation (FMT) reduced radiation pneumonia, scavenged oxidative stress and improved lung function in mouse models. Local chest irradiation shifted the gut bacterial taxonomic proportions, which were preserved by FMT. The level of gut microbiota-derived PGF2α decreased following irradiation but increased after FMT. Experimental mice with PGF2α replenishment, via an oral route, exhibited accumulated PGF2α in faecal pellets, peripheral blood and lung tissues, resulting in the attenuation of inflammatory status of the lung and amelioration of lung respiratory function following local chest irradiation. PGF2α activated the FP/MAPK/NF-κB axis to promote cell proliferation and inhibit apoptosis with radiation challenge; silencing MAPK attenuated the protective effect of PGF2α on radiation-challenged lung cells. Together, our findings pave the way for the clinical treatment of radiotherapy-associated complications and underpin PGF2α as a gut microbiota-produced metabolite.

Dietary exposure of general Chinese population to fatty acid esters of 3-monochloropropane-1, 2-diol (3-MCPD) from edible oils and oil-containing foods.

Edible oils and oil-containing foods have been regarded as the main source of 3-monochloropropane-1, 2-diol (3-MCPD) esters. A total of 3,847 individual food samples were collected in China to carry out 3-MCPD fatty acid esters analysis. The samples comprising edible oils, fried foods and bakery foods from 31 Chinese provinces, municipalities and autonomous regions were obtained from the national food contaminant information system during 2015-2017. The dietary exposure and potential risks associated with the consumption of 3-MPCD esters from edible oils and oil-containing foods were estimated using a semi-probabilistic assessment model. Concentrations of 3-MCPD fatty acid esters in food samples were detected by gas chromatography-mass spectrometry (GC-MS). The mean levels of 3-MCPD fatty acid esters in edible oils, fried foods and bakery foods were 0.862, 0.249 and 0.145 mg/kg, respectively. The range of mean dietary intakes of 3-MCPD esters in different subpopulation groups (classified by gender and age) was from 0.586 to 1.539 µg/kg bw/day, which were all lower than 2 µg/kg bw/day - the tolerable daily intake (TDI) established by the European Food Safety Authority (EFSA). The range of dietary intake of 3-MCPD esters in high consumers (95th percentile) in each group was from 1.511 to 4.027 µg/kg bw/day, which accounted for 75.6% to 201.4% of the TDI. The 3-MCPD esters exposure level of 3.5% of the total Chinese population exceeded the TDI. The findings indicate that the potential health risks caused by dietary 3-MCPD esters from edible oils and oil-containing foods were of low concern for most of the Chinese population. However, the exposure risk of the consumers with excessive edible oil consumption calls for attention.

[Determination of 20 kinds of ß-receptor blockers in animal foods by ultra high performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish an analytical method for determination of 20 kinds of ß-receptor blockers residues in animal foods by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: The samples of animal foods were enzymatic hydrolysis by trichloroacetic acid(TCA), purified by MCX column. The separation was performed on a Waters ACQUITYTM BEH C_(18 )column(100 mm×2. 1 mm, 1. 7 µm), then the target compounds were detected by UPLC-MS/MS with ESI positive ion scan in mode of multiple reaction monitoring(MRM) and quantified by matrix matched external standard method. RESULTS: At the spiked level of 1, 2 and 4 µg/kg, the recoveries of each compound were in the range of 61. 9%-119. 1% with the relative standard deviations of 1. 5%-28. 4%(n=6). The qualitative limits of detections were 0. 01-0. 15 µg/kg and the quantitative limits were 0. 03-0. 50 µg/kg for the 20 targets compounds. By using the established method, the target compounds in 30 animal foods were detected, and no excessive veterinary drug residue were detected. CONCLUSION: The established method is simple, rapid, high sensitivity and good stability, with a wide variety and a certain development. It can provide more convenient and fast detection method support for the daily monitoring of veterinary drug residues in animal foods.

[Determination of α_2-agonists in animal food by ultra high performance liquid chromatography -tandem mass spectrometry].

OBJECTIVE: To establish an analytical method for determination of 6 kinds of α_2-agonists in animal foods by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: The samples of animal food were enzymatic hydrolysis by ß-glucosidase/arylsulfatase, purified by MCX column. The separation was performed on a Dikma leapsil C_(18) column(2. 1 mm×100 mm, 2. 7 µm), then the target compound were detected by ultra high performance liquid chromatography-tandem mass spectrometry with electron spray ionization(ESI) positive ion scan in mode of multiple reaction monitoring(MRM) and quantified by matrix matched external standard method. RESULTS: At the spiked level of 1, 2 and 4 µg/kg, the recoveries of each compound were in the range of 70. 4%-111. 2% with the relative standard deviations of 2. 3%-18. 8%. The qualitative limits of detections were 0. 06-0. 3 µg/kg and the quantitative limits were 0. 2-1. 0 µg/kg for the 6 targets compounds. By using the established method, the target compound in 30 samples including pork, pig liver, pig kidney, beef and mutton were detected, and no excessive veterinary drug residue were detected. CONCLUSION: The established method is simple, rapid, high sensitivity and good stability, with a wide variety and a certain development. It can provide more convenient and fast detection method support for the daily monitoring of veterinary drug residues in animal food.

Gut microbiota-derived indole 3-propionic acid protects against radiation toxicity via retaining acyl-CoA-binding protein.

BACKGROUND: We have proved fecal microbiota transplantation (FMT) is an efficacious remedy to mitigate acute radiation syndrome (ARS); however, the mechanisms remain incompletely characterized. Here, we aimed to tease apart the gut microbiota-produced metabolites, underpin the therapeutic effects of FMT to radiation injuries, and elucidate the underlying molecular mechanisms. RESULTS: FMT elevated the level of microbial-derived indole 3-propionic acid (IPA) in fecal pellets from irradiated mice. IPA replenishment via oral route attenuated hematopoietic system and gastrointestinal (GI) tract injuries intertwined with radiation exposure without precipitating tumor growth in male and female mice. Specifically, IPA-treated mice represented a lower system inflammatory level, recuperative hematogenic organs, catabatic myelosuppression, improved GI function, and epithelial integrity following irradiation. 16S rRNA gene sequencing and subsequent analyses showed that irradiated mice harbored a disordered enteric bacterial pattern, which was preserved after IPA administration. Notably, iTRAQ analysis presented that IPA replenishment retained radiation-reprogrammed protein expression profile in the small intestine. Importantly, shRNA interference and hydrodynamic-based gene delivery assays further validated that pregnane X receptor (PXR)/acyl-CoA-binding protein (ACBP) signaling played pivotal roles in IPA-favored radioprotection in vitro and in vivo. CONCLUSIONS: These evidences highlight that IPA is a key intestinal microbiota metabolite corroborating the therapeutic effects of FMT to radiation toxicity. Owing to the potential pitfalls of FMT, IPA might be employed as a safe and effective succedaneum to fight against accidental or iatrogenic ionizing ARS in clinical settings. Our findings also provide a novel insight into microbiome-based remedies toward radioactive diseases. Video abstract.