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Qin Z, Zhou YN, Chen HH, Gu J. Extracorporeal membrane oxygenation for out-of-hospital cardiac arrest: A bibliometric analysis. Asian J Surg 2024:S1015-9584(24)00310-5. [PMID: 38388264 DOI: 10.1016/j.asjsur.2024.02.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Affiliation(s)
- Zhen Qin
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yan-Nan Zhou
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Hao-Han Chen
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Jun Gu
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China.
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Cheng XQ, Cheng J, Zhou YN, Zuo YM, Liu XS, Gu EW, Xu GH. Anti-nociceptive Effects of Dexmedetomidine Infusion Plus Modified Intercostal Nerve Block During Single-port Thoracoscopic Lobectomy: A Double-blind, Randomized Controlled Trial. Pain Physician 2021; 24:E565-E572. [PMID: 34323443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
BACKGROUND Multimodal general anesthesia based on modified intercostal nerve block (MINB) has been found as a novel method to achieve an intraoperative opioid-sparing effect. However, there is little information about the effective method to inhibit visceral nociceptive stress during single-port thoracoscopic surgery. OBJECTIVE To investigate whether a low-dose dexmedetomidine infusion followed by MINB might be an alternative method to blunt visceral stress effectively. STUDY DESIGN Double-blind, randomized control trial. SETTING Affiliated hospital from March 2020 through September 2020. METHODS Fifty-four patients were randomized (1:1), 45 patients were included to receive dexmedetomidine with a 0.4 microgram/kg bolus followed by 0.4 microgram/kg/h infusion (group Dex) or saline placebo (group Con). During the operation, an additional dose of remifentanil 0.05-0.25 microgram/kg/min was used to keep mean arterial pressure (MAP) or heart rate (HR) values around 20% below baseline values. The primary outcome was to evaluate remifentanil consumption. Secondary outcomes included intraoperative hemodynamics, the first time to press an analgesia pump, and adverse effects. RESULTS Remifentanil consumption during surgery was markedly decreased in the Dex group than in the Con group (0 [0-0] versus 560.0 [337.5-965.0] microgram; P = 0.00). MAP and HR in the Con group during the first 5 minutes after visceral exploration was significantly higher than in the Dex group (P < 0.05). Time to first opioid demand was significantly prolonged (P = 0.04) and postoperative length of stay was shortened slightly in the Dex group (P = 0.05). LIMITATIONS This study was limited by the measurement of nociception. CONCLUSIONS This study demonstrates that low-dose dexmedetomidine infusion combined with MINB might be an effective alternative method to blunt visceral stress in patients undergoing single-port thoracoscopic lobectomy. Furthermore, the analgesic effect of MINB was significantly prolonged after dexmedetomidine infusion.
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Affiliation(s)
- Xin-Qi Cheng
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Juan Cheng
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yan-Nan Zhou
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - You-Mei Zuo
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Xue-Sheng Liu
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Er-Wei Gu
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
| | - Guang-Hong Xu
- Department of Anesthesiology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China
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3
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Zhou Y, Zhou YN, Liu SX, Wang J, Ji R, Yan X. Effects of PIM3 in prognosis of colon cancer. Clin Transl Oncol 2021; 23:2163-2170. [PMID: 33928496 DOI: 10.1007/s12094-021-02624-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/13/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE PIM kinase is called proto-oncogene, but there are less research on PIM family in colon cancer. This study was designed to explore the prognosis of PIM3 in colon cancer. METHODS In this study, we downloaded RNA-seq and clinical information of colon cancer from the Gene Expression Omnibus (GEO) database. Kaplan-Meier method was used for analyzing the impact of PIM3 on the survival of patients with colon cancer. Single-factor and multi-factor cox regression analysis were used for verifying the prognostic value of PIM3. Spearman correlation analysis was used for screening PIM3 related genes. Functional enrichment analysis was used for analyzing the biological functions and pathways in which PIM3 related genes may be involved. STRING online tools were used for building a co-expression network. Cytoscape was used for co-expression network visualization. RESULTS Compared with the low expression group, the patients in the PIM3 high expression group lived longer time. Single-factor and multi-factor cox regression analysis indicated that PIM3 was an independent prognostic factor for colon cancer. Sixty-two PIM3 related genes were screened, and GO and KEGG enrichment analyses suggested that PIM3 related genes might be involved in the MAPK and WNT pathways. The co-expression network showed a strong correlation between PIM3 and MLKL, MYL5, PPP3R1 and other genes. CONCLUSIONS PIM3 is an independent prognostic factor of colon cancer and may be a target for the diagnosis and treatment of colon cancer.
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Affiliation(s)
- Y Zhou
- Department of Geriatrics (II), The First Hospital of Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Y N Zhou
- Department of Gastroenterology, The First Hospital of Lanzhou University, No.1 Donggangxi Road, Chengguan District, Lanzhou, 730000, People's Republic of China.
| | - S X Liu
- Department of Geriatrics (II), The First Hospital of Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - J Wang
- Department of Geriatrics (II), The First Hospital of Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - R Ji
- Department of Gastroenterology, The First Hospital of Lanzhou University, No.1 Donggangxi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
| | - X Yan
- Department of Geriatrics (II), The First Hospital of Lanzhou University, Lanzhou, 730000, People's Republic of China
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4
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Liu ZZ, Ren Q, Zhou YN, Yang HM. Bioequivalence of two esomeprazole magnesium enteric-coated formulations in healthy Chinese subjects. World J Clin Cases 2020; 8:5518-5528. [PMID: 33344542 PMCID: PMC7716327 DOI: 10.12998/wjcc.v8.i22.5518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/06/2020] [Accepted: 09/08/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The pharmacokinetics and bioequivalence of esomeprazole in healthy Chinese subjects and the effects of food on the pharmacokinetics have not been well studied.
AIM To evaluate the pharmacokinetic characteristics of esomeprazole magnesium (Eso) enteric- coated capsule in the healthy subjects in China and the bioequivalence of the two formulations.
METHODS This study was conducted in the Phase I Clinical Trial Unit of the Affiliated Hospital of Changchun University of Chinese Medicine. A total of 64 healthy subjects were enrolled in the study. Thirty-two subjects fasted or fed, took the test or reference formulation Eso enteric-coated capsule by a four-cycle, two-sequence crossover of fasting/fed, self-controlled method. The liquid chromatography-mass spectrometry was performed to determine the drug plasma concentration at 16 different time points within 12 h after drug administration. The pharmacokinetic parameters Cmax, area under the curve (AUC)0-t, and AUC0-inf were calculated to evaluate the bioequivalence.
RESULTS Pharmacokinetic parameters were evaluated after subjects took the test formulation and control formulation under fasting status. The ratio of geometric means of Cmax was 104.15%, with a confidence interval (CI) of 98.20-110.46%. The ratio of geometric means of AUC0-t was 105.26%, with a CI of 99.80-111.01%. The ratio of geometric means of AUC0-inf was 105.37%, with a CI of 99.97-111.06%. The pharmacokinetic parameters were also evaluated after subjects took the reference formulation of Eso enteric-coated capsule after eating. The upper limit of 95% CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state Cmax was -0.1689, and the point estimate was 0.9509 (0.80-1.25). The upper limit of 95% CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-t was -0.1015 (≤ 0) , and the point estimate was 0.9003 (0.80-1.25). The upper limit of 95% CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-inf was -0.0593 (≤ 0), and the point estimate was 0.8453 (0.80-1.25). The results indicated that the two formulations were bioequivalent under both fasting and fed states.
CONCLUSION The two types of esomeprazole tablets were bioequivalent under both fasting and fed states, and both were generally well tolerated.
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Affiliation(s)
- Zheng-Zhi Liu
- Phase I Clinical Trial Laboratory, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Qing Ren
- Phase I Clinical Trial Laboratory, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Yan-Nan Zhou
- Phase I Clinical Trial Laboratory, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Hai-Miao Yang
- Phase I Clinical Trial Laboratory, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
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Chen YL, Wang H, Zhou YN, Lu ZH, Peng M, Sun F, Huang YH. [Epidemiological characteristics of COVID-19 in Wuchang district of Wuhan]. Zhonghua Liu Xing Bing Xue Za Zhi 2020; 41:1616-1622. [PMID: 33297617 DOI: 10.3760/cma.j.cn112338-20200412-00565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyzes epidemiological characteristics of COVID-19 and provide evidence for adjustment for COVID-19 prevention and control strategies. Methods: The data of COVID-19 cases in Wuchang district reported as of 19 March, 2020 were obtained from National Notifiable Disease Report System of Chinese Disease Prevention and Control Information System. The software's of Excel 2010, SPSSS 22.0, Arc GIS10.2 and Joinpoint regression program 4.8.0.0 were used for statistical analysis. Results: A total of 7547 COVID-19 cases had been reported as of 19 March, 2020 in Wuchang district, including 5 448 confirmed cases (72.19%), 2009 clinical diagnosed cases (26.62%) and 90 asymptomatic cases case (1.19%). The age of the cases was (56.65±16.25) years and age ranged from 2 days to 105 years among confirmed cases, 2634 were males (48.35%) and 2814 were females (51.65%), 2 492 were retirees (45.74%). A total of 545 health workers were infected with SARS-CoV-2 (7.22% of all cases) including 365 confirmed cases and 5 cases have died. A total of 430 cases of death were reported with case fatality rate of 7.89% (430/5 448), case fatality rate of males (10.9%, 266/2 634) was higher than that of females (5.82%, 164/2 814). The first phase of epidemic peak was from January 24 to January 26, the second phase of epidemic peak was from February 1 to February 5 and there was no one of new confirmed case in one day for the first time on March 18. The first four Streets with the highest incidence rates of confirmed cases were Huanghelou Street (1 043.77/100 000), Ziyang Street (627.97/100 000), Yangyuan Street (503.67/100 000) and Shuiguohu Street (486.02/100 000). Compared with females, aged ≤50 years and mild cases of clinical classification respectively, males (RR=0.690, 95%CI: 0.322-1.478), aged >50 years (RR=11.745, 95%CI: 6.878-20.058), severe cases (RR=2.317, 95%CI: 1.789-3.000) and critical cases of clinical classification (RR=10.794, 95%CI: 7.997-14.569), and gender time-dependent covariate (RR=1.392, 95%CI: 1.053-1.840) were major influencing factors of prognosis of COVID-19 confirmed cases. Conclusions: The gender, ages and occupation of distribution were wide among COVID-19 cases in Wuchang district. Males, aged >50 years, severe cases and critical cases of clinical classification were influencing factors of prognosis of COVID-19 confirmed cases. The standardized management of discharged cases, asymptomatic infected cases and close contact persons were main measures to reduce incidence rates of COVID-19 cases.
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Affiliation(s)
- Y L Chen
- Jiyuqiao Street Community Health Service Center of Wuchang District of Wuhan, Wuhan 430071, China
| | - H Wang
- Wuhan Wuchang District Health Bureau, Wuhan 430071, China
| | - Y N Zhou
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan 430071, China
| | - Z H Lu
- Renmin Hospital of Wuhan University, Wuhan 430071, China
| | - M Peng
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan 430071, China
| | - F Sun
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan 430071, China
| | - Y H Huang
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan 430071, China
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6
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Wang HY, Zeng X, Bai SY, Pu K, Zheng Y, Ji R, Guo QH, Guan QL, Wang YP, Zhou YN. The safety and efficacy of endoscopic submucosal dissection for treating early oesophageal carcinoma: a meta-analysis. Ann R Coll Surg Engl 2020; 102:702-711. [PMID: 32820658 DOI: 10.1308/rcsann.2020.0177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Oesophageal carcinoma is the sixth most lethal cancer in the world. At present, the choice of specific surgical methods is controversial. This study compares the safety and efficacy of endoscopic submucosal dissection and endoscopic mucosal resection in treating early oesophageal carcinoma. METHODS We carried out a search of online databases including the Web of Science, PubMed, Embase and the Cochrane Library with no language restrictions. The inclusion criteria were patients with early oesophageal carcinoma who accepted the treatment of endoscopic submucosal dissection compared with endoscopic mucosal resection. FINDINGS A total of 1,462 patients with 1,650 lesions from nine studies were included in the meta-analysis. When compared with the endoscopic mucosal resection group, the en bloc resection (endoscopic submucosal dissection 67.94% vs endoscopic mucosal resection 52.78%; odds ratio 19.79, p = 0.000) and complete resection (endoscopic submucosal dissection 75.57% vs endoscopic mucosal resection 59.47%; odds ratio 16.10, p = 0.000) rates were significantly higher in the endoscopic submucosal dissection group, while the local recurrence rate was significantly lower in the endoscopic submucosal dissection group (endoscopic submucosal dissection 0.08% vs endoscopic mucosal resection 2.66%; odds ratio 0.08, p = 0.000). The incidence of complications and procedural time were also tested.
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Affiliation(s)
- H Y Wang
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - X Zeng
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - S Y Bai
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - K Pu
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - Y Zheng
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - R Ji
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - Q H Guo
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - Q L Guan
- Department of Oncological Surgery, First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - Y P Wang
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
| | - Y N Zhou
- Department of Gastroenterology, First Hospital of Lanzhou University, Lanzhou, Gansu, China.,Key Laboratory for Gastrointestinal Diseases of Gansu Province, Lanzhou University, Lanzhou, Gansu, China
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7
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Liu XJ, Xia SY, Yang Y, Wu JF, Zhou YN, Ren YW. Spatiotemporal dynamics and impacts of socioeconomic and natural conditions on PM 2.5 in the Yangtze River Economic Belt. Environ Pollut 2020; 263:114569. [PMID: 32311638 DOI: 10.1016/j.envpol.2020.114569] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 05/16/2023]
Abstract
The determination of the spatiotemporal patterns and driving factors of PM2.5 is of great interest to the atmospheric and climate science community, who aim to understand and better control the atmospheric linkage indicators. However, most previous studies have been conducted on pollution-sensitive cities, and there is a lack of large-scale and long-term systematic analyses. In this study, we investigated the spatiotemporal evolution of PM2.5 and its influencing factors by using an exploratory spatiotemporal data analysis (ESTDA) technique and spatial econometric model based on remote sensing imagery inversion data of the Yangtze River Economic Belt (YREB), China, between 2000 and 2016. The results showed that 1) the annual value of PM2.5 was in the range of 23.49-37.67 μg/m3 with an inverted U-shaped change trend, and the PM2.5 distribution presented distinct spatial heterogeneity; 2) there was a strong local spatial dependence and dynamic PM2.5 growth process, and the spatial agglomeration of PM2.5 exhibited higher path-dependence and spatial locking characteristics; and 3) the endogenous interaction effect of PM2.5 was significant, where each 1% increase in the neighbouring PM2.5 levels caused the local PM2.5 to increase by at least 0.4%. Natural and anthropogenic factors directly and indirectly influenced the PM2.5 levels. Our results provide spatial decision references for coordinated trans-regional air pollution governance as well as support for further studies which can inform sustainable development strategies in the YREB.
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Affiliation(s)
- Xiao-Jie Liu
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Si-You Xia
- School of Geographical Science, Nanjing Normal University, Nanjing, 210023, China
| | - Yu Yang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Jing-Fen Wu
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yan-Nan Zhou
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ya-Wen Ren
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
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8
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Zhao RH, Zhou YN, Li H, Li R, Zhang WJ, Zong H. [Influence of apatinib and VEGFR2-906T>C polymorphism on clinical outcomes of advanced non-small cell lung cancer patients]. Zhonghua Yi Xue Za Zhi 2019; 99:105-110. [PMID: 30669747 DOI: 10.3760/cma.j.issn.0376-2491.2019.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the clinical outcomes of advanced non-small cell lung cancer (NSCLC) treated by apatinib regimens and the influence of VEGFR2-906T>C polymorphism. Methods: A total of 109 patients with advanced NSCLC who were treated by apatinib after three and more lines from March 2015 to December 2017 in the Department of Oncology of the First Affiliated Hospital of Zhengzhou University were included in this study. Overall response rates were evaluated after 2 cycles, then progression free survival (PFS) and overall survival (OS) were investigated, and safety data were recorded. Additionally, peripheral blood and the biopsy tissue specimens of some NSCLC patients were collected for the genotyping of genetic variation and VEGFR2 gene mRNA expression, respectively. The association between genotype and other characteristics and VEGFR2 gene mRNA expression were analyzed. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate analysis were adjusted by Cox regression analysis. Results: The treatment effect could be evaluated in all the 109 patients, among them, complete remission (CR) 0 case, partial remission (PR) 19 case, stable disease (SD) 58 case, progression disease (PD) 32 case. Overall response rate (ORR) was 17.43%, disease control rate (DCR) was 70.64%, median PFS was 4.35 months, median OS was 8.35 months. Of the polymorphisms analyzed, only -906T>C was of clinical significance. The prevalence of -906T>C in VEGFR2 among the study population were as follows: TT genotype 64 cases (58.72%), TC genotype 37 cases (33.94%), CC genotype 8 cases (7.34%), minor allele frequency of -906T>C was 0.24. The distribution of three genotypes was in accordance with Hardy-Weinberg Equilibrium (P=0.418). CC and TC genotype patients were merged in the comparison of clinical outcomes. The analysis of patients with different genotypes found that the ORR of CC/TC genotypes and TT genotypes were 13.33% and 20.31% (P=0.377), respectively. And the median PFS of patients with CC/TC genotype and TT genotype were 3.25 and 5.35 months, respectively, which was statistically significant (P=0.007). In terms of OS, the median OS of the two genotypes were 7.35 and 9.15 (P=0.014), respectively. Adjusted in multivariate Cox regression analysis of PFS, TC/CC genotypes were an independent factor for PFS (OR=1.83, P=0.015). The correlation between -906T>C and adverse reactions was not found in the safety analysis. Additionally, of the 69 biopsy tissue specimens, gene expression analysis was conducted. And the results show that the mRNA expression of VEGFR2 in cancer tissues of the patients with CC/TC genotypes were significantly higher than those of the TT genotype patients (P<0.001). Conclusions: Apatinib is safe and effective for patients with advanced non-small cell in multiline therapy. VEGFR2 -906T>C CC/TC genotype has a worse effect on apatinib multiline treatment in patients with advanced NSCLC.
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Affiliation(s)
- R H Zhao
- Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
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9
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Shi P, Qiu QS, Zhuang G, Gao L, Zhou YN, Zhou CX. Measurement of density fluctuation propagation direction via the far-forward collective scattering diagnostic based on polarimeter-interferometer. Rev Sci Instrum 2018; 89:10C110. [PMID: 30399876 DOI: 10.1063/1.5038845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Previously, the 17-channel three-wave polarimeter-interferometer system (POLARIS) on the J-TEXT tokamak has been implemented to measure far-forward collective scattering (FFCS) from electron density fluctuations. Recently, this system has been exploited to measure the propagation direction of density fluctuation. After considering the refraction of the laser probe beam passing through plasma, the ray tracing result shows that the detector of POLARIS may receive asymmetric far-forward scattering beams. Thus, the heterodyne detection of FFCS is available to identify the propagation direction of density fluctuation by resolving the asymmetric scattering spectrum. Experimentally, the transform of the heterodyne scattering spectrum from symmetry to asymmetry has been observed, while the refraction effect becomes strong demonstrating the capacity of measuring the propagation direction of fluctuation. Furthermore, by changing the plasma potential through the use of an applied positive electrode biasing, the reverse of frequency shift for the heterodyne scattering spectrum is identified, confirming the validity of direction discrimination of density fluctuation.
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Affiliation(s)
- P Shi
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Q S Qiu
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - G Zhuang
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - L Gao
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y N Zhou
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - C X Zhou
- International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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10
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Shi P, Chen J, Gao L, Liu Y, Liu H, Zhou YN, Zhuang G. Far-forward collective scattering measurements by FIR polarimeter-interferometer on J-TEXT tokamak. Rev Sci Instrum 2016; 87:11E110. [PMID: 27910372 DOI: 10.1063/1.4960067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The multi-channel three-wave polarimeter-interferometer system on J-TEXT tokamak has been exploited to measure far-forward collective scattering from electron density fluctuations. The diagnostic utilizes far infrared lasers operated at 432 μm with 17-channel vertical chords (3 cm chord spacing), covering the entire cross section of plasma. Scattering laser power is measured using a high-sensitivity Schottky planar diode mixer which can also detect polarimetric and interferometric phase simultaneously. The system provides a line-integrated measurement of density fluctuations with maximum measurable wave number: k⊥max ≤ 2 cm-1 and time response up to 350 kHz. Feasibility of the diagnostic has been tested, showing higher sensitivity to detect fluctuation than interferometric measurement. Capability of providing spatial-resolved information of fluctuation has also been demonstrated in preliminary experimental applications.
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Affiliation(s)
- P Shi
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - J Chen
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - L Gao
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - H Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y N Zhou
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - G Zhuang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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Chen J, Zhuang G, Li Q, Liu Y, Gao L, Zhou YN, Jian X, Xiong CY, Wang ZJ, Brower DL, Ding WX. High resolution polarimeter-interferometer system for fast equilibrium dynamics and MHD instability studies on Joint-TEXT tokamak (invited). Rev Sci Instrum 2014; 85:11D303. [PMID: 25430163 DOI: 10.1063/1.4891603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A high-performance Faraday-effect polarimeter-interferometer system has been developed for the J-TEXT tokamak. This system has time response up to 1 μs, phase resolution < 0.1° and minimum spatial resolution ∼15 mm. High resolution permits investigation of fast equilibrium dynamics as well as magnetic and density perturbations associated with intrinsic Magneto-Hydro-Dynamic (MHD) instabilities and external coil-induced Resonant Magnetic Perturbations (RMP). The 3-wave technique, in which the line-integrated Faraday angle and electron density are measured simultaneously by three laser beams with specific polarizations and frequency offsets, is used. In order to achieve optimum resolution, three frequency-stabilized HCOOH lasers (694 GHz, >35 mW per cavity) and sensitive Planar Schottky Diode mixers are used, providing stable intermediate-frequency signals (0.5-3 MHz) with S/N > 50. The collinear R- and L-wave probe beams, which propagate through the plasma poloidal cross section (a = 0.25-0.27 m) vertically, are expanded using parabolic mirrors to cover the entire plasma column. Sources of systematic errors, e.g., stemming from mechanical vibration, beam non-collinearity, and beam polarization distortion are individually examined and minimized to ensure measurement accuracy. Simultaneous density and Faraday measurements have been successfully achieved for 14 chords. Based on measurements, temporal evolution of safety factor profile, current density profile, and electron density profile are resolved. Core magnetic and density perturbations associated with MHD tearing instabilities are clearly detected. Effects of non-axisymmetric 3D RMP in ohmically heated plasmas are directly observed by polarimetry for the first time.
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Affiliation(s)
- J Chen
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - G Zhuang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Q Li
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - L Gao
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Y N Zhou
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - X Jian
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - C Y Xiong
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Z J Wang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - D L Brower
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W X Ding
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
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12
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Hou YY, Tan YS, Sun MH, Wei YK, Xu JF, Lu SH, A-Ke-Su SJ, Zhou YN, Gao F, Zheng AH, Zhang TM, Hou WZ, Wang J, Du X, Zhu XZ. C-kit gene mutation in human gastrointestinal stromal tumors. World J Gastroenterol 2004; 10:1310-4. [PMID: 15112348 PMCID: PMC4622772 DOI: 10.3748/wjg.v10.i9.1310] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To investigate the significance of c-kit gene mutation in gastrointestinal stromal tumors (GIST).
METHODS: Fifty two cases of GIST and 28 cases of other tumors were examined. DNA samples were extracted from paraffin sections and fresh blocks. Exons 11, 9 and 13 of the c-kit gene were amplified by PCR and sequenced.
RESULTS: Mutations of exon 11 were found in 14 of 25 malignant GISTs (56%), mutations of exon 11 of the c-kit gene were revealed in 2 of 19 borderline GISTs (10.5%), and no mutation was found in benign tumors. The mutation rate showed significant difference (χ2 = 14.39, P < 0.01) between malignant and benign GISTs. Most of mutations consisted of the in-frame deletion or replication from 3 to 48 bp in heterozygous and homozygous fashions, None of the mutations disrupted the downstream reading frame of the gene. Point mutations and frame deletions were most frequently observed at codons 550-560, but duplications were most concentrated at codons 570-585. No mutations of exons 9 and 13 were revealed in GISTs, Neither c-kit gene expression nor gene mutations were found in 3 leiomyomas, 8 leiomyosarcomas, 2 schwannomas, 2 malignant peripheral nerve sheath tumors, 2 intra-abdominal fibromatoses, 2 malignant fibrous histiocytomas and 9 adenocarcinomas.
CONCLUSION: C-kit gene mutations occur preferentially in malignant GISTs and might be a clinically useful adjunct marker in the evaluation of GISTs and can help to differentiate GISTs from other mesenchymal tumors of gastrointestinal tract, such as smooth muscle tumors, schwannomas, etc.
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Affiliation(s)
- Ying-Yong Hou
- Department of Pathology, Zongshan Hospital, Fudan University, Shanghai 200032, China
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Abstract
PURPOSE To elucidate the relationship between angiogenesis and prognosis after curative resection of hepatocellular carcinoma (HCC). METHODS An immunohistochemical study using anti-CD34 monoclonal antibody was carried out on surgical specimens from 78 HCC patients who had undergone curative resection; microvessel density (MVD) was counted and the overall survival and disease-free survival were analyzed retrospectively. RESULTS Blood vessels in the tumor were strongly stained by anti-CD34 antibody, but not those in the surrounding liver parenchyma. There were three types of tumor vessels: capillary-like (n = 59), sinusoid-like (n = 16) and mixed-type (n = 3). The median MVD count was 100 per field. The HCC were designated as hypovascular (n = 36) with an MVD count below 100, and hypervascular (n = 42) with an MVD count of 100 or more per field. The 5-year survival and disease-free survival rates were 49.7% and 42.8% respectively, and statistical analysis showed that the MVD level was not correlated with tumor size, capsule status, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase, and serum HBsAg status. The sinusoid-like tumor vessels appeared more frequently in the more differentiated tumors (P<0.05). No statistical difference in overall and disease-free survival between different MVD levels and microvessel types was found. Tumor size was the only predicting factor in the entire series. In patients with small HCC (< or =5 cm, n = 40), 5-year survival and disease-free survival rates were 58.9% and 52.7% respectively, higher than the values in large HCC (39.8% and 32.0% respectively, P<0.05). The MVD level was an independent predicting factor of disease-free survival, 5-year disease-free survival in the hypovascular group (74.6%) being better than that in the hypervascular group (34.7%, P<0.05). CONCLUSIONS The MVD level was not related to tumor size, capsule statuo, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase and serum HBsAg status. In the entire series, tumor size was the only factor influencing survival after curative resection. However, in patients with small HCC, the MVD level was an independent factor of disease-free survival. The pathological and clinical implications of different types of tumor vessels in HCC remain to be studied.
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Affiliation(s)
- H C Sun
- Liver Cancer Institute and Zhong Shan Hospital, Shanghai Medical University, P.R. China
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Zhou YN, Jin DJ. The rpoB mutants destabilizing initiation complexes at stringently controlled promoters behave like "stringent" RNA polymerases in Escherichia coli. Proc Natl Acad Sci U S A 1998; 95:2908-13. [PMID: 9501189 PMCID: PMC19668 DOI: 10.1073/pnas.95.6.2908] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In Escherichia coli, stringently controlled genes are highly transcribed during rapid growth, but "turned off" under nutrient limiting conditions, a process called the stringent response. To understand how transcriptional initiation at these promoters is coordinately regulated, we analyzed the interactions between RNA polymerase (RNAP) (both wild type and mutants) and four stringently controlled promoters. Our results show that the interactions between RNAP and stringently controlled promoters are intrinsically unstable and can alternate between relatively stable and metastable states. The mutant RNAPs appear to specifically further weaken interactions with these promoters in vitro and behave like "stringent" RNAPs in the absence of the stringent response in vivo, constituting a novel class of mutant RNAPs. Consistently, these mutant RNAPs also activate the expression of other genes that normally require the response. We propose that the stability of initiation complexes is coupled to the transcription of stringently controlled promoters, and this unique feature coordinates the expression of genes positively and negatively regulated by the stringent response.
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Affiliation(s)
- Y N Zhou
- Laboratory of Molecular Biology, Building 37, Room 2E14, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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15
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Joo DM, Nolte A, Calendar R, Zhou YN, Jin DJ. Multiple regions on the Escherichia coli heat shock transcription factor sigma32 determine core RNA polymerase binding specificity. J Bacteriol 1998; 180:1095-102. [PMID: 9495746 PMCID: PMC106995 DOI: 10.1128/jb.180.5.1095-1102.1998] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have analyzed the core RNA polymerase (RNAP) binding activity of the purified products of nine defective alleles of the rpoH gene, which encodes sigma32 in Escherichia coli. All mutations studied here lie outside of the putative core RNAP binding regions 2.1 and 2.2. Based on the estimated K(s)s for the mutant sigma and core RNAP interaction determined by in vitro transcription and by glycerol gradient sedimentation, we have divided the mutants into three classes. The class III mutants showed greatly decreased affinity for core RNAP, whereas the class II mutants' effect on core RNAP interaction was only clearly seen in the presence of sigma70 competitor. The class I mutant behaved nearly identically to the wild type in core RNAP binding. Two point mutations in class III altered residues that were distant from one another. One was found in conserved region 4.2, and the other was in a region conserved only among heat shock sigma factors. These data suggest that there is more than one core RNAP binding region in sigma32 and that differences in contact sites probably exist among sigma factors.
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Affiliation(s)
- D M Joo
- Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA
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16
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Abstract
This work describes a mutational analysis of the interaction between the beta and sigma subunits of Escherichia coli RNA polymerase. The rpoD800 mutant has a temperature-sensitive growth phenotype because the mutant sigma70 polypeptide is not stable at a high temperature. Some rpoB mutations, including rpoB114, enhanced the temperature sensitivity of the rpoD800 mutant. We determined the mechanism by which the rpoB114 rpoD800 double mutant becomes hyper-temperature sensitive for growth. We found that the levels of the mutant sigma70 in the rpoB114 rpoD800 mutant were dramatically reduced compared to that in the rpoD800 mutant after temperature shift-up. The rate of synthesis of the sigma70 polypeptide was reduced in the rpoB114 rpoD800 double mutant compared to the rpoD800 mutant, whereas the half-life of the mutant sigma70 polypeptide after temperature shift-up was the same in both strains. We conclude that because of the reduction of expression of rpoD800 by rpoB114, in concert with the intrinsic instability of the mutant sigma70 polypeptide, the amount of holoenzyme containing sigma70 becomes limiting upon temperature shift-up. This results in the hyper-temperature sensitivity of the rpoB114 rpoD800 double mutant. Furthermore, the effect of rpoB114 on the expression of sigma70 is independent of the rpoD800 allele and is at the transcriptional level. In vitro transcription assays showed that the mutant RNA polymerase RpoB114 was defective in transcribing the two major promoters of the rpoD operon specifically. The effects of these rpoB mutations on gene expression are discussed.
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Affiliation(s)
- Y N Zhou
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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17
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Chatterjee S, Zhou YN, Roy S, Adhya S. Interaction of Gal repressor with inducer and operator: induction of gal transcription from repressor-bound DNA. Proc Natl Acad Sci U S A 1997; 94:2957-62. [PMID: 9096328 PMCID: PMC20304 DOI: 10.1073/pnas.94.7.2957] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Gal repressor inhibits transcription from the gal promoter (P1) when it binds to the cognate operator (O(E)). The repression is relieved by the presence of the inducer D-galactose. Compared with its interaction with free repressor, D-galactose binds to the repressor-operator complex with 10-fold reduced affinity as determined by fluorescence enhancement measurements. Thermodynamic analysis and fluorescence anisotropy showed that the stability of the repressor-operator complex is reduced by only 7-fold by the presence of the inducer in the complex. The formation of the inducer-repressor-operator ternary complex has been confirmed by CD spectral analysis. Fluorescence spectroscopy and energy transfer experiments suggest that individual allosteric effects of the two ligands, inducer and operator, on Gal repressor are responsible for the slightly weakened stability of the ternary complex compared with the stability of the inducer-repressor and repressor-operator complexes. In vitro transcription results demonstrated full derepression of transcription of the P1 promoter under conditions in which the concentrations of the inducer-repressor binary complex are severalfold higher than the dissociation constant of the inducer-repressor-operator ternary complex into inducer-repressor and free DNA. These results strongly suggest that the inducer binding to the repressor-operator complex does not lead to dissociation of the repressor from the operator during transcription induction. Because Gal repressor inhibits transcription by modulating the alpha subunit of the P1-bound RNA polymerase, we conclude that the inducer binding to the operator-bound repressor only allosterically relieves the inhibitory effect of repressor on RNA polymerase without dissociating the repressor from DNA.
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Affiliation(s)
- S Chatterjee
- Department of Biophysics, Bose Institute, Calcutta, India
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Affiliation(s)
- D J Jin
- Laboratory of Molecular Biology, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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19
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Abstract
We isolated and characterized mutant repressors (GalR) of the gal operon in Escherichia coli. These repressors (super-repressors), called GalRs, have a non-inducible phenotype. Repression of the gal operon by super-repressors cannot be lifted by inducer. The mutant galR genes, galRs, have been cloned and the mutational changes determined. Two of them, galRuv7s and galR78s, were located in the proposed sugar binding domains of the repressor. The repressor from wild-type (galR+), as well as from mutant galRuv7s, was purified and characterized biochemically. The results showed that, like wild-type GalR+, GalRuv7s binds to DNA normally and represses transcription from the P1 promoter and stimulates that from the P2 promoter of the gal operon. Nevertheless, compared to GalR+, GalRuv7s is much less sensitive to the presence of the inducer, D-galactose. The affinity of D-galactose to GalRuv7s is 10 to 30-fold lower, as measured by the effect of the inducer on GalR tryptophan fluorescence; GalR complexes with DNA and on GalR repression of transcription. Our results suggest that the super-repressor phenotype of GalRuv7s is because of a defect in D-galactose binding rather than a defect in the ligand-induced allosteric change or increased affinity for the operator.
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Affiliation(s)
- Y N Zhou
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Zhou YN, Gross CA. How a mutation in the gene encoding sigma 70 suppresses the defective heat shock response caused by a mutation in the gene encoding sigma 32. J Bacteriol 1992; 174:7128-37. [PMID: 1385385 PMCID: PMC207402 DOI: 10.1128/jb.174.22.7128-7137.1992] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In Escherichia coli, transcription of the heat shock genes is regulated by sigma 32, the alternative sigma factor directing RNA polymerase to heat shock promoters. sigma 32, encoded by rpoH (htpR), is normally present in limiting amounts in cells. Upon temperature upshift, the amount of sigma 32 transiently increases, resulting in the transient increase in transcription of the heat shock genes known as the heat shock response. Strains carrying the rpoH165 nonsense mutation and supC(Ts), a temperature-sensitive suppressor tRNA, do not exhibit a heat shock response. This defect is suppressed by rpoD800, a mutation in the gene encoding sigma 70. We have determined the mechanism of suppression. In contrast to wild-type strains, the level of sigma 32 and the level of transcription of heat shock genes remain relatively constant in an rpoH165 rpoD800 strain after a temperature upshift. Instead, the heat shock response in this strain results from an approximately fivefold decrease in the cellular transcription carried out by the RNA polymerase holoenzyme containing mutant RpoD800 sigma 70 coupled with an overall increase in the translational efficiency of all mRNA species.
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Affiliation(s)
- Y N Zhou
- Department of Bacteriology, University of Wisconsin, Madison 53706
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21
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Abstract
sigma 70, encoded by rpoD, is the major sigma factor in Escherichia coli. rpoD285 (rpoD800) is a small deletion mutation in rpoD that confers a temperature-sensitive growth phenotype because the mutant sigma 70 is rapidly degraded at high temperature. Extragenic mutations which reduce the rate of degradation of RpoD285 sigma 70 permit growth at high temperature. One class of such suppressors is located in rpoH, the gene encoding sigma 32, an alternative sigma factor required for transcription of the heat shock genes. One of these, rpoH113, is incompatible with rpoD+. We determined the mechanism of incompatibility. Although RpoH113 sigma 32 continues to be made when wild-type sigma 70 is present, cells show reduced ability to express heat shock genes and to transcribe from heat shock promoters. Glycerol gradient fractionation of sigma 32 into the holoenzyme and free sigma suggests that RpoH113 sigma 32 has a lower binding affinity for core RNA polymerase than does wild-type sigma 32. The presence of wild-type sigma 70 exacerbates this defect. We suggest that the reduced ability of RpoH113 sigma 32 to compete with wild-type sigma 70 for core RNA polymerase explains the incompatibility between rpoH113 and rpoD+. The rpoH113 cells would have reduced amounts of sigma 32 holoenzyme and thus be unable to express sufficient amounts of the essential heat shock proteins to maintain viability.
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Affiliation(s)
- Y N Zhou
- Department of Bacteriology, University of Wisconsin-Madison 53706
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22
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Zhai Q, Zhou YN, Liu WJ. Sporadic acute non-A, non-B hepatitis complicated by aplastic anemia and haemolysis. Chin Med J (Engl) 1990; 103:959-60. [PMID: 2125920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Q Zhai
- Department of Infectious Diseases, First Affiliated Hospital, Xinjiang Medical College, Urumchi
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23
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Zhou YN, Kusukawa N, Erickson JW, Gross CA, Yura T. Isolation and characterization of Escherichia coli mutants that lack the heat shock sigma factor sigma 32. J Bacteriol 1988; 170:3640-9. [PMID: 2900239 PMCID: PMC211339 DOI: 10.1128/jb.170.8.3640-3649.1988] [Citation(s) in RCA: 170] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The product of the Escherichia coli rpoH (htpR) gene, sigma 32, is required for heat-inducible transcription of the heat shock genes. Previous studies on the role of sigma 32 in growth at low temperature and in gene expression involved the use of nonsense and missense rpoH mutations and have led to ambiguous or conflicting results. To clarify the role of sigma 32 in cell physiology, we have constructed loss-of-function insertion and deletion mutations in rpoH. Strains lacking sigma 32 are extremely temperature sensitive and grow only at temperatures less than or equal to 20 degrees C. There is no transcription from the heat shock promoters preceding the htpG gene or the groESL and dnaKJ operons; however, several heat shock proteins are produced in the mutants. GroEL protein is present in the rpoH null mutants, but its synthesis is not inducible by a shift to high temperature. The low-level synthesis of GroEL results from transcription initiation at a minor sigma 70-controlled promoter for the groE operon. DnaK protein synthesis cannot be detected at low temperature, but can be detected after a shift to 42 degrees C. The mechanism of this heat-inducible synthesis is not known. We conclude that sigma 32 is required for cell growth at temperatures above 20 degrees C and is required for transcription from the heat shock promoters. Several heat shock proteins are synthesized in the absence of sigma 32, indicating that there are additional mechanisms controlling the synthesis of some heat shock proteins.
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Affiliation(s)
- Y N Zhou
- Department of Bacteriology, University of Wisconsin, Madison 53706
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24
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Grossman AD, Zhou YN, Gross C, Heilig J, Christie GE, Calendar R. Mutations in the rpoH (htpR) gene of Escherichia coli K-12 phenotypically suppress a temperature-sensitive mutant defective in the sigma 70 subunit of RNA polymerase. J Bacteriol 1985; 161:939-43. [PMID: 3882672 PMCID: PMC214988 DOI: 10.1128/jb.161.3.939-943.1985] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Escherichia coli K-12 strain 285c contains a mutation in rpoD, the gene encoding the sigma subunit of RNA polymerase. The 70-kilodalton sigma polypeptide encoded by this allele is unstable, and this instability leads to temperature-sensitive growth. We describe the isolation and characterization of four temperature-resistant pseudorevertants of 285c that can grow at high temperature. Each of these revertants increased the stability of the sigma 70 mutant protein. The map position of the suppressor mutations was close to that of the rpoH (htpR) gene. A multicopy plasmid containing the intact rpoH gene restored the temperature-sensitive phenotype. Marker rescue experiments established the positions of three of the alleles within the rpoH gene. One mutation has been sequenced and causes a leucine-to-tryptophan change 7 amino acids from the carboxyl terminus of the rpoH gene product.
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