Integrated Approaches to Testing and Assessment(IATA)is a toxicological assessment decision-making method that integrates existing information from various sources,including physical and chemical properties,animal testing,and non-animal testing.Through the evaluation and analysis of a series of iterative strategies,it ultimately obtains risk assessment conclusions,thereby providing a basis for risk management decisions regarding chemical substances.The use of IATA is becoming increasingly prevalent in such areas as ocular irritation and genotoxicity.This paper introduces the conceptual connotation of IATA,sorts out the framework elements and sequential processes,explains the commonly used framework construction methods,shares cases of application in various exposure scenarios,and finally envisions future research directions in order to provide better methodological support for the risk assessment of chemical substances.

AIM: To investigate the effect of flutamide on mitochondrial biogenesis and the regulating effect of anoxidative pathway Nrf2 on it. METHODS: Human hepatocyte HepG2 cells were treated with flutamide (0-50 μmol/L) for 24 h, then mtDNA copy number and protein expression of mitochondrial biogenesis were detected by RT-PCR and WB. The effects of ERK1/2 and the role of Nrf2 pathway in mitochondrial biogenesis were further observed by gene knockdown and protein activation/inhibition methods. RESULTS: Flutamide interfered mitochondrial biogenesis concentration-dependently, the mtDNA copy number, ERK1/2 and PGC-1α proteins increased with the dose. ERK1/2 inhibition and activation regulated flutamide-induced mtDNA copy number and PGC-1α expression, and inhibition of Nrf2 pathway also affected flutamide-induced mtDNA copy number and expression of PGC-1α, as well as ERK1/2 expression. CONCLUSION: Flutamide affects mitochondrial biogenesis, and the antioxidant pathway Nrf2 may be involved in the regulation of flutamine-induced mitochondrial biogenesis by regulating ERK1/2.

Objective To evaluate the repeated dose toxicity of MNT-016 in SD rats and to provide reference for toxicity evaluation.Methods MNT-016 was administered to rats at 5, 20 and 80 mg/kg for 90 days.The toxic effects on the animals were evaluated by observing the clinical signs and measuring the body weight, hematology and blood biochemistry as well as histopathological examination.NOAEL and benchmark dose lower confidence limit(BMDL) were observed by the end point of toxicity.Results Compared with the control group, the AST, TBIL, DBIL and Crea of male rats were increased in a dose-dependent manner, while TG and CHOL decreased.The body mass(before anatomy), heart, liver, thymus, epididymis of male rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of the heart and lung was increased.The body mass (before anatomy) and thymus of female rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of lungs was increased.Vacuolation of hepatocytes was observed in groups each dose, tubule atrophy was found in the kidneys of 20 and 5 mg/kg groups, and tubule basophilia was observed in 80 mg/kg group.The incidence of the above lesions was higher in male animals than in female ones.Conclusion The NOAEL of MNT-016 is lower than 5 mg/kg in male rats and 5 mg/kg in female rats.BMDL value is 2.65 mg/kg in male animals and more accurate than NOAEL, and is 9.04 mg/kg in female animals,which is slightly larger than the corresponding NOAEL.

SUMMARY Thehumanembryonicstemcells(hESCs)serveasaself-renewable,genetically-healthy, pluripotent and single source of all body cells,tissues and organs.Therefore,it is considered as the good standard for all human stem cells by US,Europe and international authorities.In this study,the standard and healthy human mesenchymal progenitors,ligament tissues,cardiomyocytes,keratinocytes,primary neurons,fibroblasts,and salivary serous cells were differentiated from hESCs.The human cellular health-safety of NaF,retinoic acid,5-fluorouracil,dexamethasone,penicillin G,adriamycin,lead ace-tate PbAc,bisphenol A-biglycidyl methacrylate (Bis-GMA)were evaluated selectively on the standar-dized platforms of hESCs,hESCs-derived cardiomyocytes,keratinocytes,primary neurons,and fibro-blasts.The evaluations were compared with those on the currently most adopted cellular platforms.Parti-cularly,the sensitivity difference of PM2.5 toxicity on standardized and healthy hESCs derived fibroblasts, currently adopted immortalized human bronchial epithelial cells Beas-2B and human umbilical vein endo-thelial cells (HUVECs)were evaluated.The results showed that the standardized hESCs cellular plat-forms provided more sensitivity and accuracy for human cellular health-safety evaluation.

Traditional drug development and pre-clinical tests are based on animals and involve large numbers of animals,costs and long periods. Meanwhile,inter-species differences are difficult to overcome. Human embryonic stem cells (hESCs),which can self-renew and directly differentiate to types of cells,have become a new tool for toxicity alternative testing. hESC-Based alternative testing models,such as the reproductive toxicity test system,neuro development toxicity test system and metabolic model,can be used to predict target organ toxicity and toxic mechanisms of chemicals, analyze metabolic pathways and to search for potential toxicity biomarkers, when combined with omics such techiniques as metabonomics , proteomics and genomics. Therefore, hESC-based alternative testing models have extensive application to toxicology.

Objective To establish the normal reference ranges of clinical pathology for Beagle dogs in the Good Laboratory Practice ( GLP ) system.Method Sixteen biochemical indexes , seventeen hematological indexs and three coagulation function indexes of 117 Beagle dogs were detected , and the mean value of each index and the normal reference ranges were calculated and compared .Results Only alkaline phosphatase ( ALP ) from the biochemical items was significantly different between males and females (P<0.01),which was higher among males than among females .Three in-dexes of hematology were significantly different between males and females (P<0.01),with red blood cell(RBC), hemo-globin(HGB)and hematocrit(HCT)lower among males than among females.The coagulation function items were not signif-icantly different between the two sexes .Conclusion Some indexes of clinical pathology were significantly different between males and females , which should be considered during statistic analysis on toxicity .Our study has established the normal reference range of clinical pathology for Beagle dogs in the GLP system , which provides reference for toxicity tests .

Objective To observe toxic symptoms and signs , toxic damage extents and reversibility in rats after oral administration of Tangwang Mingmu granules .Methods Four dose groups with 40 rats in each group were designed in this study, including control group fed with distilled water and three groups at different dosages of the test drug .Tangwang Mingmu granules were orally administered to SD rats at the dosage of 8.4, 4.2 and 2.1 g/kg for 3 weeks and 14.0, 8.4 and 4.2 g/kg for 23 weeks, for 26 consecutive weeks .The general state of the rats was observed every day , while body mass and food consumption were calculated once a week .Halfway through and at the end of the administration (13 and 26 weeks) and after four weeks of recovery, parameters of body mass, hematology, hematological biochemistry, organ/body mass ratio and histopathology were measured .Results Compared with the control group at the same time-point, body mass of male rats in the other three groups was slightly reduced .Food consumption in high and medium dose groups was reduced (P<0.05), MCHC, ALT, TBIL and Na +in high dose group were decreased (P<0.05), TP, ALB and D-BIL were increased (P<0.05), the mean body mass and relative organ weight of thymus in medium dose male rats were decreased (P<0.05), relative organ weight of the liver and kidney in high dose male rats was increased (P<0.05), and focal chronic inflammation to different extent was observed in the liver , kidney and prostate gland .No dose-effect relationship was found in these perturbations that were all within the normal range of animals .No significant drug-related pathological changes were found.Conclusion The NOAEL of Tangwang Mingmu granules is considered to be 14.0 g/kg body mass/day (equal to 50 times the proposed clinical adult dosage ) for the 26-week repeated dose oral toxicity study in male andfemale rats.

The purpose of risk assessment is to evaluate the permissible exposure level under specific risk factors.To extrapolate the human acceptable daily intake (ADI) and/or reference dose (RfD), the traditional method uses the no-observed-adverse-effect level ( NOAEL ) to quantify toxicity after being divided by uncertainty factor.There are many limitations with NOAEL method in safety evaluation,for it relies too much on experimental design.Benchmark dose ( BMD) approach is a more reliable method with many advantages.BMD approach and its analysis software, the advantages of BMD over NOAEL, the application and methodological perfection in risk assessment of long-team exposure toxicity are presented in this review.

OBJECTIVE To investigate the role of gonadotropin-releasing hormone (GnRH) in es-tradiol(E2 ) induced advance of puberty onset in rats. METHODS Postnatal day 18 SD rats were given a daily intragastric administration of corn oil or E2(50 μg.kg-1 ) for consecutive 5 d. The day of vaginal opening (VO), pathological changes in ovary and protein expression levels of GnRH, G protein-coupled receptor 54 ( GPR54) and phospholipase C ( PLC) in hypothalamus were observed. RESULTS As compared to corn oil controll group, VO was advanced by about 12.2 d, corpus luteum was observed in the ovary section, and the protein expression levels of GnRH,GPR54 and PLC in hypothalamus were significantly increased by 47%, 55% and 56% in E2 group, respectively. CONCLUSION E2 induced onset of puberty advance may be closely related to regulation of the expression of GnRH, GPR54 and PLC in hypothalamus.

Objective To explore the effect on metabolism of glucose and lipids, potential toxicity mechanism and possible biomarker candidates by analyzing urine metabonome changes of rats after oral administration of polychlorinated biphenyl congeners( PCBs) and high fat diet alone or in combination.Methods Male SD rats were divided randomly into control group,high fat diet group, PCBs group and combination group of PCBs and high fat diet.Urine samples were collected after 6-week treatment, 1 H NMR spectra were performed and analyzed by principal component analysis ( PCA) . Results The PCA scores plot of urine 1 H NMR data showed that the combined group could be easily distinguished from the other three groups, suggesting great difference in metabolism.The loading plot of the PCA revealed significant increase in the levels of lactate, glucose, creatine, 2-hydroxy-isovaleric acid and reduction in the levels of citrate, succinate, taurine, hippurate and trimethylamine oxide ( TMAO) in the combined exposure group after six-week exposure.Conclusion The altered levels of metabolites induced by combined exposure of PCBs and high fat diet may be related to the injury to mitochondrial function, reduction of energy metabolism in tricarboxylic acid cycle (TAC).These effects possibly lead to perturbations in the metabolism of glucose, lipid and amino acids.The altered metabolites may be considered biomarker candidates of toxicity induced by exposure to PCBs and high fat diet.