1.Exploration of the role of cisplatin on transformation of larvngeal tumor cells to stem-like cancer cells.
Maomao AI ; Feng YU ; Xin HUANG
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2015;29(4):346-351
OBJECTIVE:
To explore the possibility mechanism of non-side population cells (NSP) of Hep-2 be induced into stem-like cancer cells by chemotherapy drug--cisplatin.
METHOD:
Hep-2 cell lines were sorted by fluorescence-actived cell sorting. The acquired NSP cells in trail group were co-cultured with cisplatin for more than 48 hours,while the control group with normal saline(NS). Then identified the percentage of the side population (SP) cells by flow cytometer. The β-catenin, notch-1 mRNA in trial and control group were detected using quantitative realtime PCR, and the β-catenin, notch-1 protein in two groups were compared by Western blot.
RESULT:
The percentage of side population cells in two groups were (17.16 ± 0.18)%, (10.05 ± 1.20)%, respectively. There was significant difference between two groups (t = 5.844, P < 0.01). The expression of β-catenin, notch-1 was higher in trail group by qRT-PCR; the protein levels of β- catenin, notch-1 was found to inceased in the trail group by Western blot (t = 5.155, P = 0.031; t = 5.977, P = 0.004). Statistical analysis showed significant difference between two groups (P < 0.05).
CONCLUSION
NSP cells can be differentiated into stem-like cancer cells after being treating with cisplatin. The supposed mechanism is maybe through wnt/β-catenin, notch signaling transduction pathway abnormalities.
Antineoplastic Agents
;
pharmacology
;
Cell Differentiation
;
Cell Line, Tumor
;
Cell Separation
;
Cisplatin
;
pharmacology
;
Flow Cytometry
;
Humans
;
Laryngeal Neoplasms
;
pathology
;
Neoplastic Stem Cells
;
drug effects
;
RNA, Messenger
;
Signal Transduction
;
beta Catenin
2.The study of siRNA interference after laryngeal cancer Hep-2 cells to cisplatin sensitivity of β-catenin gene expression.
Feng YU ; Xin HUANG ; Maomao AI ; Ying LIN
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2015;29(13):1143-1147
OBJECTIVE:
To investigate the changes of laryngeal cancer Hep-2 cells to cisplatin chemosensitivity after the interference of siRNA of β-catenin gene expression.
METHOD:
Using a small interference RNA (siRNA) technology interfere β-catenin gene of Hep-2 cells . The mRNA and protein levels of β-catenin in the Hep-2 cells of different groups were detected by qPCR and Western blot. It was divided into siRNA-β-catenin-Hep-2 siRNA group, β-catenin-Neg negative control group and blank control group. Cell proliferation inhibition rate of different concentrations of cisplatin on three groups was detected by MTT assay. Calculate the 50% inhibitory effective concentration IC50 value. Check the change of three groups of cells' apoptosis rate by flow cytometry after the same concentrations of cisplatin stimulation.
RESULT:
β-catenin-siRNA interference fragment can specifically reduce the expression levels of β-catenin mRNA and protein. qPCR illustrated the expression of mRNA in β-catenin-siR-NA-Hep-2 interference group decreased 70% (P < 0.05) compared with the control group, Western blot results showed that the β-catenin protein expression of interference group (0. 545 ± 0.111) decreased significantly compared with blank control group (1.507 ± 0.139) and negative control group (1.429 ± 0.089), P < 0.05. The IC50 calculation software showed that IC50 of cisplatin on β-catenin-siRNA IC50 interference group is (5.81 ± 0.46)μg/ml, the blank control group is (10.10 ± 1.01) μg/ml, the difference between the two groups has statistical signifi- cance (P < 0.01). Cell apoptosis rate of β-catenin-siRNA interference group was (26.15 ± 0.60)%, significantly higher than the control group (14.16 ± 0.05)%, P < 0.05.
CONCLUSION
To interfere the expression of β-catenin can effectively enhance the sensitivity of laryngeal cancer cells to chemotherapeutic drugs cisplatin. It provides a theoretical support for the reduction of laryngeal cancer chemotherapy drug cisplatin dosage.
Apoptosis
;
Cell Line, Tumor
;
Cisplatin
;
pharmacology
;
Drug Resistance, Neoplasm
;
Humans
;
Laryngeal Neoplasms
;
genetics
;
RNA Interference
;
RNA, Messenger
;
RNA, Small Interfering
;
beta Catenin
;
genetics
3.Preliminary exploration of prostate cancer screening mode based on the medical community model in primary hospitals
Liwei ZHENG ; Lingmin SONG ; Gang WANG ; Weizhi ZHU ; Liejun HOU ; Maomao LI ; Jianjun HUANG ; Kewen ZHOU ; Bin ZHENG ; Xiaoming XU ; Guobin WENG
Chinese Journal of Urology 2024;45(6):416-419
Objective:To explore the suitable prostate cancer screening mode under the medical community for primary hospitals.Methods:From April 2021 to April 2022, a total of 16007 male population ≥50 years from 9 branches of the medical community of the second hospital of Yinzhou participated in this study. They were divided into four groups according to age with group 1 of 50-59 years old, group 2 of 60-69 years old, group 3 of 70-79 years old, and group 4 of 80 years old and above. Serum tPSA was added to the routine physical examination, and the screening positive patients were referred to the referral hospital for further diagnosis and treatment under the mode of medical community. We proposed multi-parametric MRI (mpMRI) for those with serum PSA ≥4 ng/ml and suspicious lesions should be scored according to PI-RADS V2. The ultrasound-guided transperineal targeted prostate biopsy was performed for those with PI-RADS ≥3 and those with PI-RADS < 3 but tPSA ≥10 ng/ml. The tPSA follow-up examinations were performed every 6 months for tPSA < 10 ng/ml and PI-RADS < 3 points and once a year for tPSA < 4 ng/ml.Results:Among the 16 007 male population ≥50 years, 2 007(12.54%) were found serum PSA ≥4 ng/ml, and 634(31.59%)were referred to the referral hospital through the medical community system. Combining tPSA and mpMRI, 271 patients underwent ultrasound-guided transperineal targeted prostate biopsy. Among them, 162 were finally diagnosed with PCa, with a biopsy positive rate of 59.78%. The detection rate of PCa in all the subjects was 1.01%. According to the pathological grade, 5(3.08%) were in ISUP group 1, 95(58.64%) in ISUP group 2-3, and 62(38.27%) in ISUP group 4-5. There were 102(62.96%), 39(24.07%) and 21(12.96%) with localized, locally advanced or metastatic PCa, respectively. The levels of tPSA in the four groups were (1.13±1.44)ng/ml, (1.77±3.45)ng/ml, (3.27±17.58)ng/ml, and (4.26±11.48)ng/ml, respectively, with statistically significant differences ( P<0.01). The positive number of biopsy in each group was 1 case(0.06%), 56 cases(0.79%), 81 cases(1.36%) and 24 cases(1.82%) respectively, with statistically significant differences ( P<0.01). The number of ISUP 4-5 grades in each group was 0, 17(30.35%), 29(35.80%), and 16(66.67%) respectively, with statistically significant differences ( P<0.01). Conclusions:Based on the medical community system, according to the tPSA screening results of the primary hospitals, it is feasible and effective to refer suspicious patients to the referral hospitals for mpMRI examination, and screen prostate cancer by ultrasound-guided transperineal prostate fusion biopsy.
4.Disease burden of liver cancer in China: an updated and integrated analysis on multi-data source evidence
Mengdi CAO ; Hong WANG ; Jufang SHI ; Fangzhou BAI ; Maomao CAO ; Yuting WANG ; Xinxin YAN ; Le WANG ; Zhen HUANG ; Jiansong REN ; Jianjun ZHAO ; Min DAI ; Chunfeng QU ; Wanqing CHEN
Chinese Journal of Epidemiology 2020;41(11):1848-1858
Objective:To analyze the disease burden of liver cancer in China.Methods:Based on eight data sources, including the series of Chinese Cancer Registry Annual Report, three national death cause surveys in China, China Health Statistical Yearbook, China Death Cause Surveillance Datasets, GLOBOCAN, Cancer Incidence in Five Continents (CI5), WHO Mortality Database and the Global Burden of Disease (GBD), the information on incidence, mortality and disability-adjusted life year (DALY) of liver cancer, were extracted for the analysis on the past, current and future disease burden caused by liver cancer in China.Results:1) Past situation: The long-term data from 1973 to 2012 reported by the CI5 showed that in urban populations in China (taking Shanghai as an example), the incidence rate of liver cancer in males and females decreased by 41.3 % and 36.3 %, respectively, and that in rural areas (taking Qidong as an example) decreased by 32.3 % and 12.2 %, respectively. The Chinese Cancer Registry Annual Reports showed that the national incidence and mortality rates of liver cancer decreased by 8.1 % and 12.8 % respectively from 2005 to 2015. The Joinpoint analysis based on the data from the China Health Statistics Yearbook also showed a declining trend: the average annual percentage change of liver cancer mortality in China from 2002 to 2017 was -3.0 % ( P<0.05), and that in rural areas was -3.1 % ( P<0.05). 2) Current status: GLOBOCAN estimates that the rates of incidence, mortality and prevalence of liver cancer in China in 2018 were 18.3 per 100 000, 17.1 per 100 000 and 10.8 per 100 000, respectively. According to the latest annual report, the incidence and mortality rates of liver cancer in cancer registration areas in 2015 were 17.6 per 100 000 and 15.3 per 100 000, respectively, and both increased with age. The mortality rate was similar to that reported in 2017 (16.7 per 100 000) by the China Death Cause Surveillance Datasets, and the male to female ratio of live cancer deaths was estimated as 3.1. The GBD 2017 reports that the DALYs caused by liver cancer in China reached 11 153.0 thousand in 2017 (accounting for 53.7 % of the global DALYs) and hepatitis B virus infection was always the leading cause. 3) Prediction: The GLOBOCAN 2018 predicts that, by 2040, the number of liver cancer cases and deaths in China would reach 591 000 and 572 000 (with an increase of 50.5 % and 54.9 %, respectively, compared with those in 2018), with a more significant increase in people over 70 years old. 4) Economic burden: According to the literature review of economic burden data on liver cancer, the direct medical expenditure per patient with liver cancer generally showed a rising trend. Conclusions:Multiple data sources indicate that the incidence and mortality rates of liver cancer in populations in China decreased in the past decades, indicating the effect of population interventions. However, the population-level disease burden are still substantial, and comprehensive intervention strategies need to be continually strengthened and optimized, especially the primary and secondary prevention.
5.An analysis of the annual expenditure per liver cancer patient in China: from the perspective of the whole disease course
Fangzhou BAI ; Chengcheng LIU ; Yuting WANG ; Hong WANG ; Maomao CAO ; Xinxin YAN ; Juan ZHU ; Le WANG ; Huiyao HUANG ; Yefan ZHANG ; Jiansong REN ; Yong WANG ; Jianjun ZHAO ; Kai ZHANG ; Ni LI ; Chunfeng QU ; Min DAI ; Wanqing CHEN ; Jufang SHI
Chinese Journal of Health Management 2019;13(5):387-393
Objective To estimate the mean annual expenditure of patients with prevalent liver cancer in China on the perspective of the natural progression of the disease and to provide baseline information for liver cancer?related disease burden estimation and evaluation of prevention strategies. Methods A multicenter survey on liver cancer was conducted between 2012 and 2014 in 13 sites where the cancer screening program was conducted in Urban China, by face?to?face interviews with hospitalized patients. Data on basic information, clinical diagnosis and treatment, direct medical expenditure, and direct non?medical expenditure were collected. By?year expenditure and number of visits from the first visit to the end of the survey were analyzed. The trend for the two indicators in each year was analyzed. The subgroup analysis of factors such as sex and age was conducted. All the expenditure data were discounted to the year 2014 and presented in Chinese yuan. The statistical analysis was performed using the SAS 9.4 software. Results A total of 2 222 patients with liver cancer, with a mean age of 55.7±11.2 years, were included. Men accounted for 79.2% (1 759 cases) of the patients, women accounted for 20.8% (463 cases) of the patients, and 75.6% (1 679 cases) of the cases were from cancer hospitals. Stage Ⅰ cases only accounted for 14.1% (299 cases) of all the cases, and most cases were stageⅢorⅣ(62.6%, 1 325 cases). Of the cases, 64.4% (1 430 cases) had pathological information, and 83.6%(1 195 cases) were pathologically hepatocellular carcinoma. The sample sizes for the first 3 years from the first visit were 2 222, 149, and 57, respectively (by?year sample sizes thereafter were<50). The annual total medical expenditures for the first 3 years were 49 091 yuan (95% confidence interval [CI]: 47 376-50 806), 30 506 yuan (95% CI: 26 462-34 549), and 32 100 yuan (95% CI: 25 917-38 283) (P<0.001). The corresponding number of visits were 1.9, 1.6, and 1.5 (P<0.001). The trend for each province was consistent with the overall trend, while the down trend from years 1 to 2 varied among provinces, ranging from 1.4 (Zhejiang province) to 5.6 times (Henan province). For the trend in the first 3 years, differences were found in subgroups such as region (P<0.001) and treatment (P<0.05), instead of sex, age, stage, and other subgroups. Conclusions For liver cancer patients in China, the annual expenditure for the first year in the whole disease course was 1.6 times higher than that for the second year, which varied among provinces. However, information on annual expenditure for the later course of liver cancer is still limited.
6.Analysis of pathogenic factors and clinical manifestations of 55 subjects with contact stomatitis
LIU Liu ; WANG Xiang ; DUAN Ning ; ZHAO Maomao ; XU Kaiyuan ; WU Kaihui ; HUANG Fan ; WANG Wenmei
Journal of Prevention and Treatment for Stomatological Diseases 2021;29(6):388-394
Objective :
To investigate the pathogenic factors and clinical manifestations of contact stomatitis, and to provide references for its clinical diagnosis and prevention.
Methods:
The data of 55 subjects with contact stomatitis were analyzed retrospectively, including age, gender, pathogenic factors, type of lesions and site of occurrence.
Results:
Among the 55 patients, contact stomatitis occurred at all ages, 19 were male, 36 were female, and the ratio of males to females was 1∶1.89. Among 55 patients, 78.18% (43/55) were caused by oral mucosal contact with dental materials: amalgam fillings accounted for 52.73% (29/55), metal crowns accounted for 9.09% (5/55), removable denture plastic bases accounted for 9.09% (5/55), resin fillings accounted for 5.45% (3/55), and alginate impression materials accounted for 1.82% (1/55); 21.82% (12/55) were caused by oral mucosal contact with food and daily necessities. The clinical manifestations of contact stomatitis include lichenoid reaction, erythema and erosion. The most common site of contact stomatitis was the cheek, followed by the tongue, and the lips, and the gingival and palatal areas were relatively rare. In the buccal mucosa, the incidence of lichenoid reaction was 55% (22/40), which was higher than that of erosion (20%) and erythema (25%), and the difference was statistically significant (P < 0.05). For tongue, lip, gingiva and palate, there was no significant difference in the incidence of the three lesion types(P > 0.05).
Conclusion
Contact stomatitis occurred at all ages, and there are more female patients than males with contact stomatitis. Dental materials, especially metal and acrylic materials (such as the plastic base of removable dentures, resin fillings, adhesives, and self-setting plastics), are the main pathogenic factors. In buccal mucosa, the incidence of lichenoid reaction is higher.
7.Priority setting in scaled-up cancer screening in China: an systematic review of economic evaluation evidences
Jufang SHI ; Ayan MAO ; Yana BAI ; Guoxiang LIU ; Chengcheng LIU ; Hong WANG ; Maomao CAO ; Hao FENG ; Le WANG ; Fangzhou BAI ; Huiyao HUANG ; Huijun BAI ; Juan ZHU ; Xinxin YAN ; Juan ZHANG ; Jiansong REN ; Ni LI ; Min DAI ; Wanqing CHEN
Chinese Journal of Preventive Medicine 2020;54(3):306-313
Objective:The existed economic evaluations of cancer screening in Chinese population are almost all single-cancer focused, evidence on parallel comparison among multiple cancers is lacking. Thus, the aim of this study was, from a priority setting perspective, to compare the cost-effectiveness of six common cancers(colorectal cancer, breast cancer, liver cancer, lung cancer, esophageal cancer and stomach cancer) to facilitate policy making in future scaled-up screening in populations in China.Methods:Partially based on our previous single-cancer systematic reviews (colorectal cancer, breast cancer, liver cancer, and lung cancer), evidence of economic evaluations of cancer screening in populations in mainland China were systematically updated and integrated. The main updates include: 1) Stomach cancer and esophageal cancer were newly added to the current analysis. 2) The literature searching was extended to 8 literature databases, including PubMed, EMbase, The Cochrane Library, Web of Science, CBM, CNKI, Wanfang Data, and VIP. 3) The period of publication year was updated to the recent 10 years: January 1, 2009 to December 31, 2018. 4) The study focused on populations in mainland China. Following the standard processes of literature searching, inclusion and exclusion from previous systematic reviews, the basic characteristics, evaluation indicators and main results of the included studies were extracted. All the costs were discounted to 2017 value using the by-year consumer price index of medical and health care residents in China and presented in the Chinese Yuan (CNY). The ratios of incremental cost-effectiveness ratio (ICER) to China′s per capita GDP in 2017 were calculated (<1 means very cost-effective, 1-3 means cost-effective, >3 means not cost-effective). Given a specific indicator, the median value among all reported screening strategies for each cancer was calculated, based on which priority ranking was then conducted among all cancers when data available.Results:A total of 45 studies were included, 22 for breast cancer, 12 for colorectal cancer, 6 for stomach cancer, 4 for esophageal cancer (all conducted in high-risk areas), 1 for liver cancer and none for lung cancer (was not then considered for next ranking due to limited numbers of studies). When based on the indicator, the median ratio of cost per life-year saved to China′s per capita GDP (reported in 12 studies), the lowest ratio (-0.015) was observed in esophageal cancer among 16 strategies of 2 studies ( N=2, n=16), followed by 0.297 for colorectal cancer ( N=3, n=12), 0.356 for stomach cancer ( N=1, n=4) and 0.896 for breast cancer ( N=6, n=52, P75=3.602). When based on another commonly used ICER indicator, the median ratio of cost per quality-adjusted life-year gained to China′s per capita GDP (reported in 13 studies), the least cost was found in stomach cancer (0.495, N=3, n=8, P75=3.126), followed by esophageal cancer (0.960, N=1, n=4, P75=1.762) and breast cancer (2.056, N=9, n=64, P75=4.217). Data was not found for colorectal cancer. In addition, cost per cancer case detected was the most adopted indicator (32 studies). The median cost among all screening strategies for each cancer was 14 759 CNY for stomach cancer ( N=5, n=7), 49 680 CNY for colorectal cancer ( N=12, n=25) and 171 930 CNY for breast cancer ( N=13, n=24), respectively. Data was not available for esophageal cancer and rare for precancer cases detected. Evidence related to cost per disability-adjusted life-year gained was not available. Conclusions:At China′s national level and limited to the six cancers covered by the current study, the preliminary analysis suggests that stomach cancer and colorectal cancer were the most cost-effective target cancers and could be given priority in the future scaled-up screening in general populations. Esophageal cancer screening should be prioritized in high-risk areas. Breast cancer was also cost-effective in general but some of the intensive screening strategies were marginal. Data on liver cancer and lung cancer were too limited to conclude, and more well-designed studies and high-quality research evidence should be required. This priority ranking might be changed if other common cancers were involved analyses.
8.Priority setting in scaled-up cancer screening in China: an systematic review of economic evaluation evidences
Jufang SHI ; Ayan MAO ; Yana BAI ; Guoxiang LIU ; Chengcheng LIU ; Hong WANG ; Maomao CAO ; Hao FENG ; Le WANG ; Fangzhou BAI ; Huiyao HUANG ; Huijun BAI ; Juan ZHU ; Xinxin YAN ; Juan ZHANG ; Jiansong REN ; Ni LI ; Min DAI ; Wanqing CHEN
Chinese Journal of Preventive Medicine 2020;54(3):306-313
Objective:The existed economic evaluations of cancer screening in Chinese population are almost all single-cancer focused, evidence on parallel comparison among multiple cancers is lacking. Thus, the aim of this study was, from a priority setting perspective, to compare the cost-effectiveness of six common cancers(colorectal cancer, breast cancer, liver cancer, lung cancer, esophageal cancer and stomach cancer) to facilitate policy making in future scaled-up screening in populations in China.Methods:Partially based on our previous single-cancer systematic reviews (colorectal cancer, breast cancer, liver cancer, and lung cancer), evidence of economic evaluations of cancer screening in populations in mainland China were systematically updated and integrated. The main updates include: 1) Stomach cancer and esophageal cancer were newly added to the current analysis. 2) The literature searching was extended to 8 literature databases, including PubMed, EMbase, The Cochrane Library, Web of Science, CBM, CNKI, Wanfang Data, and VIP. 3) The period of publication year was updated to the recent 10 years: January 1, 2009 to December 31, 2018. 4) The study focused on populations in mainland China. Following the standard processes of literature searching, inclusion and exclusion from previous systematic reviews, the basic characteristics, evaluation indicators and main results of the included studies were extracted. All the costs were discounted to 2017 value using the by-year consumer price index of medical and health care residents in China and presented in the Chinese Yuan (CNY). The ratios of incremental cost-effectiveness ratio (ICER) to China′s per capita GDP in 2017 were calculated (<1 means very cost-effective, 1-3 means cost-effective, >3 means not cost-effective). Given a specific indicator, the median value among all reported screening strategies for each cancer was calculated, based on which priority ranking was then conducted among all cancers when data available.Results:A total of 45 studies were included, 22 for breast cancer, 12 for colorectal cancer, 6 for stomach cancer, 4 for esophageal cancer (all conducted in high-risk areas), 1 for liver cancer and none for lung cancer (was not then considered for next ranking due to limited numbers of studies). When based on the indicator, the median ratio of cost per life-year saved to China′s per capita GDP (reported in 12 studies), the lowest ratio (-0.015) was observed in esophageal cancer among 16 strategies of 2 studies ( N=2, n=16), followed by 0.297 for colorectal cancer ( N=3, n=12), 0.356 for stomach cancer ( N=1, n=4) and 0.896 for breast cancer ( N=6, n=52, P75=3.602). When based on another commonly used ICER indicator, the median ratio of cost per quality-adjusted life-year gained to China′s per capita GDP (reported in 13 studies), the least cost was found in stomach cancer (0.495, N=3, n=8, P75=3.126), followed by esophageal cancer (0.960, N=1, n=4, P75=1.762) and breast cancer (2.056, N=9, n=64, P75=4.217). Data was not found for colorectal cancer. In addition, cost per cancer case detected was the most adopted indicator (32 studies). The median cost among all screening strategies for each cancer was 14 759 CNY for stomach cancer ( N=5, n=7), 49 680 CNY for colorectal cancer ( N=12, n=25) and 171 930 CNY for breast cancer ( N=13, n=24), respectively. Data was not available for esophageal cancer and rare for precancer cases detected. Evidence related to cost per disability-adjusted life-year gained was not available. Conclusions:At China′s national level and limited to the six cancers covered by the current study, the preliminary analysis suggests that stomach cancer and colorectal cancer were the most cost-effective target cancers and could be given priority in the future scaled-up screening in general populations. Esophageal cancer screening should be prioritized in high-risk areas. Breast cancer was also cost-effective in general but some of the intensive screening strategies were marginal. Data on liver cancer and lung cancer were too limited to conclude, and more well-designed studies and high-quality research evidence should be required. This priority ranking might be changed if other common cancers were involved analyses.
9.Surface electromyography of lower limb muscles in healthy middle-aged and old women during stair ascent and descent
Dan LI ; Jianxiong WANG ; Maomao HUANG ; Fangyuan XU ; Qiu ZENG ; Jiyang LI ; Yang LI ; Cuihong XIA ; Yadan ZHENG ; Zhangyu XU ; Wenfeng FANG ; Tenggang WAN
Chinese Journal of Rehabilitation Theory and Practice 2023;29(6):731-737
ObjectiveTo observe the lower limb muscle activation strategy of healthy middle-aged and old women during stair ascent and descent with surface electromyography. MethodsFrom August, 2021 to February, 2022, 20 healthy middle-aged and old women were measured the surface electromyography root mean square (RMS) and integrated electromyography (iEMG) of bilateral vastus lateral, rectus femoris, vastus medialis, biceps femoris and semitendinosus during stair ascent and descent, and co-contraction ratio was calculated. ResultsDuring stair ascent, the RMS of bilateral vastus lateral, rectus femoris and vastus medialis was higher at starting stage than at following stage (|t| > 6.650, P < 0.001), while the RMS of biceps femoris and semitendinosus was lower (t > 3.559, P < 0.01); and the co-contraction ratio of hamstrings/quadriceps was lower at starting stage than at following stage (t > 8.185, P < 0.001). During stair descent, the RMS of bilateral vastus lateral, vastus medialis, biceps femoris and semitendinosus was higher at following stage than at starting stage (t > 2.345, P < 0.05), as well as the co-contraction ratio of hamstrings/quadriceps (t > 2.405, P < 0.05). ConclusionThe activities of the muscles around the knees are almost symmetrical during stair ascent and descent for healthy middle-aged and old women. The activation and co-contraction ratio of quadriceps and hamstring are various at starting/following stages.