2.Media optimization for exopolysaccharide by Pholiota squarrosa (Pers. ex Fr.) Quel. AS 5.245 on submerged fermentation.
Yun-Xiang WANG ; Zhao-Xin LU ; Feng-Xia LÜ
Chinese Journal of Biotechnology 2004;20(3):414-422
Our previous work has indicated that mycelium growth and exopolysaccharide accumulation in submerged fermentation by Pholiota squarrosa (Pers. ex Fr.) Quel. AS 5.245 are strongly affected by many internal and external factors, including medium constituents and fermentation conditions. In this study, we use an effective two-phase statistical approach to enhance exopolysaccharide production. In the first phase, Plackett-Burman design was undertaken to evaluate the effects of the twenty factors, i.e., glucose, fructose, maltose, yeast extract, tryptone, K2HPO4, KH2PO4, (NH4)2SO4, NaNO3, FeSO4, MgSO4, MnCl2, ZnCl2, FeCl3, CuSO4.5H2O, vitamin B1, initial pH, the temperature, the medium volume and the duration, to the fermentation. By regression analysis, yeast extract, tryptone, fructose, MgSO4, MnCl2, initial pH and temperature were found to be important for exopolysaccharide production, while glucose, maltose, NaNO3, ZnCl2, vitamin B1, the duration and the volume are important to the mycelium biomass. In the second phase of the optimization process, a response surface methodology (RSM) was used to optimize the above critical internal factors, and to find out the optimal concentration levels and the relationships between these factors. Based on the results of the first phase, a five-level six-factor (yeast extract, fructose, MgSO4, maltose, ZnCl2 and initial pH) central composite rotatable design (CCRD) was employed. By solving the quadratic regression model equation using appropriate statistic methods, the optimal concentrations for obtaining 876.32 microg exopolysaccharide per milliliter of fermentation liquor were calculated as: 6.0g/L yeast extract, 11.5g/L fructose, 0.5g/L MgSO4, 9.6g/L maltose, 38.6mg/L ZnCl2 and with the initial pH 5.3. The experimental data under various conditions have validated the theoretical values.
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Fructose
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metabolism
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Hydrogen-Ion Concentration
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Maltose
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metabolism
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Pholiota
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growth & development
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Temperature
4.Mechanism of multidrug resistance of human small cell lung cancer cell line H446/VP.
Yan-Ling WANG ; Yun-Li YAN ; Na-Jing ZHOU ; Shuo HAN ; Jun-Xia ZHAO ; Cui-Li CAO ; Yu-Hong LÜ
Chinese Medical Journal 2010;123(22):3299-3303
BACKGROUNDSmall cell lung cancer (SCLC) is the most aggressive form of lung cancer. This study aimed to investigate the mechanism of human small cell lung cancer cell line resistance to etoposide (VP-16), H446/VP.
METHODSThe cell viability was measured by MTT assay. Immunocytochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting methods were used to detect the multidrug resistance gene (MDR1), bcl-2, bax and the topoisomerase II (Topo II) expressions in H446 and H446/VP cells after treated with or without VP-16.
RESULTSThe 50% inhibition concentration (IC50) of VP-16 on H446 cells was 49 mg/L, and 836 mg/L was for H446/VP cells. The expressions of MDR1 and bcl-2 were up-regulated, while the amounts of bax and Topo II were reduced in H446/VP cells. After treated with 49 mg/L of VP-16, it showed that the drug could significantly inhibit bcl-2 and Topo II expressions, and increase bax expression in H446 cells compared with that of H446/VP cells.
CONCLUSIONSThe H446/VP cell was stably resistant to VP-16. The decreased expression of Topo II was correlated with the H446/VP multidrug resistance. The elevated expressions of MDR1, and the altered apoptotic pathways also played an important role in VP-16 induced multidrug resistance of SCLC.
ATP Binding Cassette Transporter, Sub-Family B ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Antigens, Neoplasm ; genetics ; metabolism ; Blotting, Western ; Cell Line, Tumor ; DNA Topoisomerases, Type II ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Drug Resistance, Multiple ; genetics ; physiology ; Drug Resistance, Neoplasm ; genetics ; physiology ; Humans ; Immunohistochemistry ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Small Cell Lung Carcinoma ; metabolism
5.Polymorphism of XRCC1 and chromosome damage in workers occupationally exposed to benzene.
Jing ZHANG ; Jian-ping LÜ ; Chen ZHANG ; Li-fang ZHOU ; Yun-jie YE ; Pin SUN ; Zhou-xiang CHENG ; Zhao-lin XIA
Chinese Journal of Industrial Hygiene and Occupational Diseases 2012;30(6):423-427
OBJECTIVETo explore the relationship between the polymorphisms of DNA repair gene (XRCC1 194, 280 and 399) and the chromosomal damage induced by benzene.
METHODSThe chromosomal damage of the peripheral lymphocytes in 459 workers occupationally exposed to benzene and 88 non-exposed controls were detected with cytokinesis-block micronucleus (CBMN) assay. PCR-RFLP technique was used to measure polymorphisms in XRCC1 194, 280 and 399.
RESULTSIt was found that the MN frequency (2.12‰ ± 1.88‰) of the exposed group was significantly higher than that (1.19‰ ± 1.68‰) of the control group (P < 0.05), in the exposed group, the MN frequency (3.00‰ ± 2.76‰) of older workers (> 35 years) was significantly higher than that (2.02‰ ± 1.71‰) of younger workers (≤ 35 years) (P < 0.05). The effect of genetic polymorphisms of XRCC1 on CBMN was not found. The haplotypes AAA/BAA, AAB/AAB, ABA/ABA, ABB/ABB could associated with the increased frequencies of total micronucleus (P < 0.05).
CONCLUSIONBenzene exposure could result in chromosome damage. Age of workers and diplotypes of XRCC1 could associated with chromosomal damage induced by benzene.
Adult ; Benzene ; adverse effects ; DNA Damage ; drug effects ; genetics ; DNA-Binding Proteins ; genetics ; Humans ; Micronuclei, Chromosome-Defective ; Micronucleus Tests ; Occupational Exposure ; Polymorphism, Single Nucleotide ; X-ray Repair Cross Complementing Protein 1 ; Young Adult
6.Response of human triple-negative breast cancer to paclitaxel after vascu-lar normalization in nude mice
zhao Rong LÜ ; yu Lu ZHAO ; zheng Chang SHI ; Wei LI ; ping Ze WENG ; Xin HUANG ; xia Ning WANG ; long Yun PAN
Chinese Journal of Pathophysiology 2017;33(10):1819-1824
AIM:To explore whether there is synergistic effect of recombinant human endostatin ( rh-Endo ) and paclitaxel (Pac) in the time window of vascular normalization and the role of magnetic resonance imaging (MRI) in early assessment of chemotherapy by observing the response of human triple -negative breast cancer ( TNBC) to Pac after vascular normalization in nude mice .METHODS:The human TNBC MDA-MB-231 cells were planted in the subcutaneous region of right lower abdomen of BALB/c-nu female nude mice .These nude mice were randomly divided into 4 groups (n=7).rh-Endo was given for 17 consecutive days in rh-Endo group and rh-Endo+Pac group.Pac was given on the 6th and 12th days in Pac group and rh-Endo+Pac group.The dosage of both drugs was 10 mg· kg-1· d-1(ip).On the day before the treatment and the 5th, 11th and 17th days after treatment, all the transplanted tumors were examined by MRI . All the mice were killed by cervical dislocation and their transplanted tumors were taken down for examinations after the last MRI on the 17th day.The changes of pathology, immunohistochemisty, microvessel density (MVD) and Ki67 expression were measured.RESULTS:On the 17th day, the volume of transplanted tumor in rh-Endo+Pac group was smaller than that in model group and rh-Endo group ( P<0.05 ) , and no difference between rh-Endo+Pac group and Pac group was found.On the 17th day, the tumor inhibitory rates in rh-Endo group, Pac group and rh-Endo+Pac group were 14.61%, 39.08%and 54.79%, respectively.The slow diffusion coefficient in Pac group was increased compared with model group , while it was decreased compared with rh-Endo+Pac group (P<0.05).No distant metastatic lesion in the tumor-bearing mice was observed .The necrotic rates in rh-Endo+Pac group and Pac group were higher than those in model group and rh-Endo group.The MVD in model group was higher than that in the other 3 groups.The MVD in rh-Endo+Pac group was decreased compared with Pac group and rh-Endo group .The Ki67 level in rh-Endo+Pac group was decreased compared with rh-Endo group , and no difference between rh-Endo+Pac group and Pac group was detected .CONCLUSION:In the time window of vascular normalization , the combination of Pac and rh-Endo has a significant antitumor effect on TNBC , but this study did not observe a significant synergistic effect of the 2 drugs.The change of slow diffusion coefficient can predict the therapeutic effect in advance .
7.Surveillance of bacterial resistance in tertiary hospitals across China:results of CHINET Antimicrobial Resistance Surveillance Program in 2022
Yan GUO ; Fupin HU ; Demei ZHU ; Fu WANG ; Xiaofei JIANG ; Yingchun XU ; Xiaojiang ZHANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Yuling XIAO ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Jingyong SUN ; Qing CHEN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yunmin XU ; Sufang GUO ; Yanyan WANG ; Lianhua WEI ; Keke LI ; Hong ZHANG ; Fen PAN ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Wei LI ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Qian SUN ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanqing ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Wenhui HUANG ; Juan LI ; Quangui SHI ; Juan YANG ; Abulimiti REZIWAGULI ; Lili HUANG ; Xuejun SHAO ; Xiaoyan REN ; Dong LI ; Qun ZHANG ; Xue CHEN ; Rihai LI ; Jieli XU ; Kaijie GAO ; Lu XU ; Lin LIN ; Zhuo ZHANG ; Jianlong LIU ; Min FU ; Yinghui GUO ; Wenchao ZHANG ; Zengguo WANG ; Kai JIA ; Yun XIA ; Shan SUN ; Huimin YANG ; Yan MIAO ; Mingming ZHOU ; Shihai ZHANG ; Hongjuan LIU ; Nan CHEN ; Chan LI ; Jilu SHEN ; Wanqi MEN ; Peng WANG ; Xiaowei ZHANG ; Yanyan LIU ; Yong AN
Chinese Journal of Infection and Chemotherapy 2024;24(3):277-286
Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5%were gram-positive and 70.5%were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3%,76.7%and 77.9%,respectively.Overall,94.0%of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8%of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2%in the isolates from children and 95.7%in the isolates from adults.The resistance rate to carbapenems was lower than 13.1%in most Enterobacterales species except for Klebsiella,21.7%-23.1%of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1%to 13.3%.The prevalence of meropenem-resistant strains decreased from 23.5%in 2019 to 18.0%in 2022 in Pseudomonas aeruginosa,and decreased from 79.0%in 2019 to 72.5%in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.