1.Pre-operative risk assessment of hepatocellular carcinoma recurrence in liver transplant recipients by non-invasive detection of pre-existing genetic lesions
Suqin YANG ; Sunbin LING ; Jianhua LI ; Yan WANG ; Jiapei WANG ; Qiwei HUANG ; Fanming LIU ; Yiqi ZHUANG ; Yingyu ZHENG ; Rui WANG ; Zhe YANG ; Xiaoping ZHENG ; Kai WANG ; Zhikun LIU ; Jun CHEN ; Jianguo WANG ; Haiyang XIE ; Lin ZHOU ; Leiming CHEN ; Guoqiang CAO ; Dandan CHEN ; Junfang JI ; Bin ZHAO ; Chao JIANG ; Di LU ; Xuyong WEI ; Hangjin JIANG ; Qiaonan SHAN ; Hengbo SHI ; Yong-Zhen XU ; Shusen ZHENG ; Zhengxin WANG ; Shengda LIN ; Xiao XU
Clinical and Molecular Hepatology 2026;32(2):884-903
Background/Aims:
Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy.
Methods:
We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues.
Results:
We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts.
Conclusion
Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.
2.Experimental study on alternative method of local lymph node assay using bromodeoxyuridine with flow cytometry(LLNA:BrdU-FCM)for skin sensitization evaluation of cosmetics
Xiao-jun LYU ; Ju ZHANG ; Sen WU ; Xiao-ling XU ; Meng-ting SHI ; Jin-jing XU ; Wang-ping PAN ; Jia-te SHEN ; Kai-yong HE
Chinese Pharmacological Bulletin 2025;41(4):793-799
Aim To establish and evaluate an alternative meth-od for detecting skin sensitization of cosmetics based on local lymph node assay using bromodeoxyuridine(BrdU)with flow cytometry(FCM).Methods(1)25%hexyl cinnamic alde-hyde(HCA)was chosen as a positive control with an acetone:olive oil(4∶1,V/V,AOO)mixture as a vehicle control for the experiment.The dorsal sides of both ears of mice were treated with test solutions on day 1,day 2,and day 3.Brdu solution was injected inter-peritoneally on day 5.On day 6,the bilateral ears and mandibular lymph nodes were excised,and the number of Brdu positive cells was measured by flow cytometry.The stim-ulation index(SI)was calculated to identify whether it was ≥3,in order to establish the method of LLNA:Brdu-FCM.(2)BrdU-FCM test was conducted using a blind method with the fif-teen reference substances listed in OECD TG429 whose skin sensitization potentials were known.The test substances were dissolved in AOO,N,N-dimethylformamide(DMF)or dimeth-yl sulfoxide(DMSO)at three different concentrations.Tests were performed the same as above.SI and EC2.7 were calculat-ed to evaluate whether the test substance was categorized as a skin sensitizer.The reliability and accuracy of the method were validated by comparing the classification of test substances with that in OECD TG429.Results The SI for 25%HCA was 3.9,showing positive in the skin sensitization test.It demonstrated that the LLNA:Brdu-FCM test method was properly implemen-ted.Nine test substances(2,4-dinitrochlorobenzene,4-pheny-lenediamine,cobalt chloride,2-mercaptobenzothiazole,hexyl-cinnamaldehyde,eugenol,phenyl benzoate,cinnamic alcohol,imidazolidinyl urea)were positive,and six test substances(methyl methacrylate,chlorobenzene,isopropanol,lactic acid,methyl salicylate,salicylic acid)were negative.The method was evaluated with sensitivity of 90%,specificity of 100%,positive prediction rate of 100%,negative prediction rate of 83%,false positive rate of 0%,false negative rate of 17%and accuracy of 93%.The LLNA:BrdU-FCM assay could correctly categorize the test substances that were skin sensitizers or non-sensitizers.Conclusion The LLNA:BrdU-FCM assay appears to be a relia-ble predictor of skin sensitization protential of chemicals,and it is expected to an alternative method for identifying skin sensitization as a supplementary in safety evaluation of cosmetic ingredient.
3.Assay for detection of toxigenic Clostridioides difficile with combined microfluidic chip and immunochromatography technology
Hong-rui CHENG ; Xiao-jun SONG ; Yu CHEN ; Meng ZHANG ; Meng-ting CAI ; Kun ZHU ; Yu-lei TAI ; Shi-bo YING ; Da-zhi JIN
Chinese Journal of Zoonoses 2025;41(2):142-149
An assay was established for detection of toxigenic Clostridioides difficile by combining microfluidic chip analysis with immunochromatography,and its performance was evaluated and compared with those of the Xpert C.difficile/Epi and VIDAS CD AB tests.Primer pairs were designed according to the tcdB and tpi genes in C.difficile.The specificity,limit of detection,reproducibility,and stability were evaluated.A total of 215 stool samples from patients with diarrhea were collected and tested in parallel with the Xpert C.difficile/Epi,VIDAS CDAB,and our assay.C.difficile was isolated from samples,and the tcdB gene was identified when discrepant results were obtained from the three above assays.Our assay showed no cross-reaction with other diarrhea-associated pathogens.Its reproducibility was 100%in testing of two standard plasmids containing tcdB and tpi genes at two concentrations(105 and 102 copies/μL).Two standard plasmids were detected after the PCR and immunochromatography reagents had been stored for 3,6,9,and 12 months,and all the results were posi-tive.The limit of detection was 10 copies/μL for toxigenic C.difficile.Testing of 33 samples positive for C.difficile with our assay(33/215,15.3%)yielded findings statistically coherent with those of the Xpert C.difficile/Epi test(kappa value=0.965).The sensitivity,specificity,positive predictive value,and negative predictive value of our assay,with respect to Xpert C.difficile/Epi as the standard,were 94.3%,100.0%,100.0%,and 98.9%;these values were significantly higher than those of VIDAS CDAB(60.0%,98.9%,91.3%,and 92.7%)(Kappa=0.714,OR=157.50,95%CI:62.03-847.28,P=0.013).In conclusion,our newly developed assay is specific,stable,and reproducible,and may be used for rapid and accu-rate detection of toxigenic C.difficile.The assay could be used for C.difficile infection screening in outpatient and emergen-cy,community medical service center,and epidemiological settings.
4.M2 macrophage-derived exosomes promote microglia M2-type polarization
Jun FANG ; Wei WEI ; Yating XUE ; Chenlong CUI ; Jiasheng WEI ; Xiao SHI ; Lijuan YANG ; Baozhong YANG
Chinese Journal of Tissue Engineering Research 2025;29(25):5320-5327
BACKGROUND:Much of the current research on M2 macrophage-derived exosomes focuses on their effects on wound healing and osteoblast proliferation and differentiation,while few studies have focused on their role in regulating microglia phenotype.OBJECTIVE:To discuss the role and molecular mechanisms of M2 macrophage-derived exosomes in the phenotypic regulation of microglia.MERHODS:(1)Bone marrow primary macrophages were extracted and then stimulated with 50 ng/mL interleukin 4 for 24 hours to promote macrophage M2-type polarization.Flow cytometry and cellular immunofluorescence were used to identify the M2-type macrophage marker CD206.(2)M2 macrophage-derived exosomes were extracted and identified.(3)Microglia BV2 were randomly divided into three groups:control group,lipopolysaccharide group,and treatment group.No treatment was done in the control group.500 ng/mL lipopolysaccharide was added to the intervention for 24 hours in the lipopolysaccharide group.500 ng/mL lipopolysaccharide and 25 μg/mL M2 macrophage-derived exosomes were added simultaneously to the treatment group for 24 hours.ELISA was performed to detect the secretion of tumor necrosis factor α and interleukin 10 in the culture supernatant.qRT-PCR was performed to detect the mRNA expression of inducible nitric oxide synthase,arginase 1,interleukin 1β,and interleukin 10 in the cells.Western blot assay was performed to detect the protein expression of inducible nitric oxide synthase,arginase 1,and nuclear factor-κB signaling pathway related protein expression.RESULTS AND CONCLUSION:(1)ELISA results showed that the secretion of tumor necrosis factor α was significantly increased in the lipopolysaccharide group compared with the control group.The secretion of tumor necrosis factor α was reduced and the secretion of interleukin 10 was increased in the treatment group compared with the lipopolysaccharide group.(2)The qRT-PCR results showed that compared with the control group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase increased in the lipopolysaccharide group.Compared with the lipopolysaccharide group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase decreased,and the mRNA expression of interleukin 10 and arginase 1 increased in the treatment group.(3)Western blot assay results showed that the expression of inducible nitric oxide synthase protein was increased in the lipopolysaccharide group compared with the control group.The expression of inducible nitric oxide synthase protein was decreased and the expression of arginase 1 protein was elevated in the treatment group compared with the lipopolysaccharide group.(4)Compared with the control group,the expression of p65 and p-IκB-α proteins in the nuclear factor-κB signaling pathway was reduced in the lipopolysaccharide group,whereas the expression of p65 and p-IκB-α proteins was elevated in the treatment group compared with the lipopolysaccharide group.The results showed that M2-type macrophage-derived exosomes could significantly inhibit lipopolysaccharide-induced inflammatory responses in microglia,enhance the expression of the anti-inflammatory factor interleukin 10,suppress the expression of the pro-inflammatory factors tumor necrosis factor α and interleukin 1β,and promote microglial cell phenotypes polarized from the M1-type to the M2-type.The mechanism may be related to the inhibition of nuclear factor-κB signaling pathway activation by M2-type macrophage-derived exosomes.
5.Association between insulin resistance and idiopathic central precocious puberty in girls and the diagnostic value of insulin resistance
Jin-Bo LI ; Ya XIAO ; Shu-Qin JIANG ; Xiang-Yang LUO ; Hong-Ru ZHANG ; Jun SUN ; Wen-Hui SHI ; Ying YANG ; Wei WANG
Chinese Journal of Contemporary Pediatrics 2025;27(12):1487-1492
Objective To explore the relationship between insulin resistance and idiopathic central precocious puberty(ICPP)in girls and the diagnostic value of insulin resistance.Methods Clinical data of 245 girls aged 4 to 7.5 years with low luteinizing hormone(LH)levels(0.2-0.83 IU/L),normal body weight(body mass index standard deviation score between-2 and+2),and early breast development who visited the Department of Pediatric Endocrinology,Henan Provincial Maternal and Child Health Hospital from January 2022 to March 2025 were retrospectively analyzed.According to the Expert Consensus on the Diagnosis and Treatment of Central Precocious Puberty(2022),patients were assigned to an ICPP group(n=123)or a control group(n=122).Correlations between the homeostasis model assessment of insulin resistance(HOMA-IR)and selected indices were assessed.Multivariable logistic regression was used to evaluate the association between HOMA-IR and ICPP,and the diagnostic performance of various indices for ICPP was evaluated.Results HOMA-IR was higher in the ICPP group than in the control group(P<0.001)and was positively correlated with LH peak(rs=0.467,P<0.05)and the LH peak/FSH peak ratio(rs=0.444,P<0.05).The multivariable logistic regression model including age,BMI,and basal LH showed that HOMA-IR was closely associated with ICPP(OR=2.756,95%CI:1.940-3.913).Receiver operating characteristic curve analysis showed that the areas under the curve for basal LH,HOMA-IR,and their combination in diagnosing ICPP were 0.735,0.735,and 0.805,respectively(P<0.05),and the combined model had a greater area under the curve than either basal LH or HOMA-IR alone(both P<0.05).Conclusions HOMA-IR is closely associated with ICPP in girls with low LH and normal body weight,and combining HOMA-IR with basal LH improves early identification and diagnostic efficiency in this population.
6.Transcatheter aortic valve implantation for native aortic valve regurgitation:single-centre experience
Xiao-xue ZHANG ; Yi FENG ; Xian-tao MA ; Yu-jie YANG ; Akilu WAJEEHULLAHI ; Chen-xi YAN ; Zi-yue ZHANG ; Zi-jun CHEN ; Bo QIN ; Shi-liang LI ; Cai CHENG
Chinese Journal of Interventional Cardiology 2025;33(1):33-41
Objective To evaluate the efficacy and safety of transcatheter aortic valve implantation(TAVI)for the treatment of primary aortic valve regurgitation(NAVR)and to compare the difference in the choice of prosthetic valve size and the difference in complications with aortic stenosis(AS).Methods According to the definition of Valve Academic Research Consortium(VARC-3),143 patients with NAVR/AS treated with TAVI and patients with NAVR treated with surgical aortic valve replacement(SAVR)at Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology,China,from March 2019 to September 2024 were selected,and clinical data on baseline,perioperative,and primary endpoint events were were retrospectively collected and compared.Results Forty-three patients with NAVR were treated with TAVI,with a device success rate of 86.0%and a surgical success rate of 95.3%.Subgroup comparisons:(1)NAVR-TAVI group than NAVR-SAVR group:patients in the TAVI group had a significantly shorter operative time than those in the SAVR group(P<0.001);complete left bundle branch block was more likely to occur after TAVI(P=0.042),and complete right bundle branch block was more likely to occur after SAVR(P=0.044).SAVR postoperatively The incidence of congestive heart failure was higher(P=0.013),and the mortality rate was significantly higher in the SAVR group than in the TAVI group(P=0.019).(2)NAVR-TAVI group than AS-TAVI group:the differences in access selection,THV size[28(22,34)mm vs.24(22,32)mm,P=0.044]and proportion of THV overdiameter[14%(7%,20%)vs.7%(3%,11%),P<0.001]were statistically significant.patients in AS and NAVR groups had 1 case of permanent pacing after TAVI treatment.In the AS and NAVR groups,there was 1 case of permanent pacemaker implantation after TAVI.2 patients in the AS group were converted to surgical treatment,and 6 patients died.Conclusions The use of"off-label"(transfemoral)and"on-label"(transapical)TAVI devices(both from domestic sources)is safer than SAVR for the treatment of NAVR,especially in elderly and high-risk patients.Compared with patients with AS treated with TAVI,larger diameter annulas are usually selected for NAVR,with higher rates of valve migration,but overall safety and efficacy are comparable to AS.
7.Association between insulin resistance and idiopathic central precocious puberty in girls and the diagnostic value of insulin resistance
Jin-Bo LI ; Ya XIAO ; Shu-Qin JIANG ; Xiang-Yang LUO ; Hong-Ru ZHANG ; Jun SUN ; Wen-Hui SHI ; Ying YANG ; Wei WANG
Chinese Journal of Contemporary Pediatrics 2025;27(12):1487-1492
Objective To explore the relationship between insulin resistance and idiopathic central precocious puberty(ICPP)in girls and the diagnostic value of insulin resistance.Methods Clinical data of 245 girls aged 4 to 7.5 years with low luteinizing hormone(LH)levels(0.2-0.83 IU/L),normal body weight(body mass index standard deviation score between-2 and+2),and early breast development who visited the Department of Pediatric Endocrinology,Henan Provincial Maternal and Child Health Hospital from January 2022 to March 2025 were retrospectively analyzed.According to the Expert Consensus on the Diagnosis and Treatment of Central Precocious Puberty(2022),patients were assigned to an ICPP group(n=123)or a control group(n=122).Correlations between the homeostasis model assessment of insulin resistance(HOMA-IR)and selected indices were assessed.Multivariable logistic regression was used to evaluate the association between HOMA-IR and ICPP,and the diagnostic performance of various indices for ICPP was evaluated.Results HOMA-IR was higher in the ICPP group than in the control group(P<0.001)and was positively correlated with LH peak(rs=0.467,P<0.05)and the LH peak/FSH peak ratio(rs=0.444,P<0.05).The multivariable logistic regression model including age,BMI,and basal LH showed that HOMA-IR was closely associated with ICPP(OR=2.756,95%CI:1.940-3.913).Receiver operating characteristic curve analysis showed that the areas under the curve for basal LH,HOMA-IR,and their combination in diagnosing ICPP were 0.735,0.735,and 0.805,respectively(P<0.05),and the combined model had a greater area under the curve than either basal LH or HOMA-IR alone(both P<0.05).Conclusions HOMA-IR is closely associated with ICPP in girls with low LH and normal body weight,and combining HOMA-IR with basal LH improves early identification and diagnostic efficiency in this population.
8.Clinical trail of vericiguat combined with sacubitril valsartan sodium in the treatment of patients with heart failure with reduced ejection fraction
Miao-jun WANG ; Shi-ping XU ; Xiao-jin PAN ; Zhi-dong YE ; Yu-fang LIAN ; Jun QIU ; Shao-tang LU ; Sheng-jie ZHOU
The Chinese Journal of Clinical Pharmacology 2025;41(1):6-10
Objective To observe the clinical efficacy and safety of vericiguat tablets combined with sacubitril valsartan sodium(Sac/Val)tablets in the treatment of patients with heart failure with reduced ejection fraction(HFrEF).Methods The HFrEF patients were divided into control group and treatment group according to the cohort method.The control group was treated with Sac/Val tablets 200 mg per time,bid,orally.On the basis of control group,the treatment group was treated with vericiguat tablets 2.5 mg per time,qd,taken with meal.Two groups were treated for 3 months.The clinical efficacy,left ventricular ejection fraction(LVEF),left ventricular end-diastolic dimension(LVEDD)and end-systolic diameter(LVESD),levels of high sensitivity C-reactive protein(hs-CRP),interleukin-6(IL-6),nitric oxide(NO),N-terminal pro-brain natriuretic peptide(NT-proBNP),blood urea nitrogen(BUN)and serum creatinine(SCr),and safety were compared between the two groups.During follow-up,the heart failure rehospitalization rates and major adverse cardiovascular events were compared between the two groups.Results Treatment group was enrolled 53 patients,control group was enrolled 53 patients.After treatment,the total effective rates of treatment and control groups were 94.34%(50 cases/53 cases)and 81.13%(43 cases/53 cases)with statistical significant difference(P<0.05).After treatment,the LVEF of treatment and control groups were(48.02±5.20)%and(43.02±4.33)%,the LVEDDs were(52.85±6.30)and(55.63±6.88)mm,the LVESDs were(41.64±6.40)and(44.22±5.85)mm,the levels of hs-CRP were(10.22±2.63)and(14.60±2.98)mg L-1,the levels of IL-6 were(14.48±2.40)and(17.36±2.52)pg·mL-1,the levels of NO were(102.60±20.16)and(92.16±16.33)μmol·L-1,the levels of NT-proBNP were(898.74±102.20)and(1315.60±182.64)ng·L-1,the levels of BUN were(12.02±2.28)and(13.45±2.33)mmol·L-1,the levels of SCr were(82.22±5.89)and(85.64±6.03)μmol·L-1,the heart failure rehospitalization rates were 5.66%and 13.21%,respectively;the differences were statistical significant between two groups(all P<0.05).The adverse drug reactions of treatment group were hyperkalemia,hypotension,renal dysfunction,dizziness and headache,while those in control group were renal dysfunction,hyperkalemia,and hypotension.The major adverse cardiovascular events of treatment group were angina pectoris and acute myocardial infarction,while those in control group were angina pectoris,acute myocardial infarction and atrial fibrillation.The incidences of total adverse drug reactions in treatment and control groups were 13.21%and 7.55%,the incidences of major adverse cardiovascular events were 5.66%and 13.21%,respectively,without statistically significant differences(all P>0.05).Conclusion Vericiguat tablets combined with Sac/Val tablets have a definitive clinical efficacy in the treatment of HFrEF patients,which can improve cardiac and endothelial function,reduce inflammatory response and readmission times,without increasing the incidences of adverse drug reactions.
9.M2 macrophage-derived exosomes promote microglia M2-type polarization
Jun FANG ; Wei WEI ; Yating XUE ; Chenlong CUI ; Jiasheng WEI ; Xiao SHI ; Lijuan YANG ; Baozhong YANG
Chinese Journal of Tissue Engineering Research 2025;29(25):5320-5327
BACKGROUND:Much of the current research on M2 macrophage-derived exosomes focuses on their effects on wound healing and osteoblast proliferation and differentiation,while few studies have focused on their role in regulating microglia phenotype.OBJECTIVE:To discuss the role and molecular mechanisms of M2 macrophage-derived exosomes in the phenotypic regulation of microglia.MERHODS:(1)Bone marrow primary macrophages were extracted and then stimulated with 50 ng/mL interleukin 4 for 24 hours to promote macrophage M2-type polarization.Flow cytometry and cellular immunofluorescence were used to identify the M2-type macrophage marker CD206.(2)M2 macrophage-derived exosomes were extracted and identified.(3)Microglia BV2 were randomly divided into three groups:control group,lipopolysaccharide group,and treatment group.No treatment was done in the control group.500 ng/mL lipopolysaccharide was added to the intervention for 24 hours in the lipopolysaccharide group.500 ng/mL lipopolysaccharide and 25 μg/mL M2 macrophage-derived exosomes were added simultaneously to the treatment group for 24 hours.ELISA was performed to detect the secretion of tumor necrosis factor α and interleukin 10 in the culture supernatant.qRT-PCR was performed to detect the mRNA expression of inducible nitric oxide synthase,arginase 1,interleukin 1β,and interleukin 10 in the cells.Western blot assay was performed to detect the protein expression of inducible nitric oxide synthase,arginase 1,and nuclear factor-κB signaling pathway related protein expression.RESULTS AND CONCLUSION:(1)ELISA results showed that the secretion of tumor necrosis factor α was significantly increased in the lipopolysaccharide group compared with the control group.The secretion of tumor necrosis factor α was reduced and the secretion of interleukin 10 was increased in the treatment group compared with the lipopolysaccharide group.(2)The qRT-PCR results showed that compared with the control group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase increased in the lipopolysaccharide group.Compared with the lipopolysaccharide group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase decreased,and the mRNA expression of interleukin 10 and arginase 1 increased in the treatment group.(3)Western blot assay results showed that the expression of inducible nitric oxide synthase protein was increased in the lipopolysaccharide group compared with the control group.The expression of inducible nitric oxide synthase protein was decreased and the expression of arginase 1 protein was elevated in the treatment group compared with the lipopolysaccharide group.(4)Compared with the control group,the expression of p65 and p-IκB-α proteins in the nuclear factor-κB signaling pathway was reduced in the lipopolysaccharide group,whereas the expression of p65 and p-IκB-α proteins was elevated in the treatment group compared with the lipopolysaccharide group.The results showed that M2-type macrophage-derived exosomes could significantly inhibit lipopolysaccharide-induced inflammatory responses in microglia,enhance the expression of the anti-inflammatory factor interleukin 10,suppress the expression of the pro-inflammatory factors tumor necrosis factor α and interleukin 1β,and promote microglial cell phenotypes polarized from the M1-type to the M2-type.The mechanism may be related to the inhibition of nuclear factor-κB signaling pathway activation by M2-type macrophage-derived exosomes.
10.Experimental study on alternative method of local lymph node assay using bromodeoxyuridine with flow cytometry(LLNA:BrdU-FCM)for skin sensitization evaluation of cosmetics
Xiao-jun LYU ; Ju ZHANG ; Sen WU ; Xiao-ling XU ; Meng-ting SHI ; Jin-jing XU ; Wang-ping PAN ; Jia-te SHEN ; Kai-yong HE
Chinese Pharmacological Bulletin 2025;41(4):793-799
Aim To establish and evaluate an alternative meth-od for detecting skin sensitization of cosmetics based on local lymph node assay using bromodeoxyuridine(BrdU)with flow cytometry(FCM).Methods(1)25%hexyl cinnamic alde-hyde(HCA)was chosen as a positive control with an acetone:olive oil(4∶1,V/V,AOO)mixture as a vehicle control for the experiment.The dorsal sides of both ears of mice were treated with test solutions on day 1,day 2,and day 3.Brdu solution was injected inter-peritoneally on day 5.On day 6,the bilateral ears and mandibular lymph nodes were excised,and the number of Brdu positive cells was measured by flow cytometry.The stim-ulation index(SI)was calculated to identify whether it was ≥3,in order to establish the method of LLNA:Brdu-FCM.(2)BrdU-FCM test was conducted using a blind method with the fif-teen reference substances listed in OECD TG429 whose skin sensitization potentials were known.The test substances were dissolved in AOO,N,N-dimethylformamide(DMF)or dimeth-yl sulfoxide(DMSO)at three different concentrations.Tests were performed the same as above.SI and EC2.7 were calculat-ed to evaluate whether the test substance was categorized as a skin sensitizer.The reliability and accuracy of the method were validated by comparing the classification of test substances with that in OECD TG429.Results The SI for 25%HCA was 3.9,showing positive in the skin sensitization test.It demonstrated that the LLNA:Brdu-FCM test method was properly implemen-ted.Nine test substances(2,4-dinitrochlorobenzene,4-pheny-lenediamine,cobalt chloride,2-mercaptobenzothiazole,hexyl-cinnamaldehyde,eugenol,phenyl benzoate,cinnamic alcohol,imidazolidinyl urea)were positive,and six test substances(methyl methacrylate,chlorobenzene,isopropanol,lactic acid,methyl salicylate,salicylic acid)were negative.The method was evaluated with sensitivity of 90%,specificity of 100%,positive prediction rate of 100%,negative prediction rate of 83%,false positive rate of 0%,false negative rate of 17%and accuracy of 93%.The LLNA:BrdU-FCM assay could correctly categorize the test substances that were skin sensitizers or non-sensitizers.Conclusion The LLNA:BrdU-FCM assay appears to be a relia-ble predictor of skin sensitization protential of chemicals,and it is expected to an alternative method for identifying skin sensitization as a supplementary in safety evaluation of cosmetic ingredient.

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