1.Comparative Study of Clinical Efficacy of Ultrafine Extracted Granule Preparation and Traditional Herbal Decoction of Li Zhong Tang
Qingping LIU ; Junfeng YAN ; Dongbo LIU ; Man LI ; Guangxian CAI
Chinese Journal of Information on Traditional Chinese Medicine 2014;(4):34-36
Objective To compare the clinical efficacy of different doses of ultrafine extracted granule preparation (EGP) and traditional herbal decoction (THD) of Li Zhong Tang in treatment of epigastric pain. Methods Sixty cases of epigastric pain patients in accordance with the diagnostic criteria of deficiency and cold pattern of spleen and stomach in TCM were randomly divided into THD group, 1/3 dose group and 1/5 dose group, and were given THD, 1/3 dose of ultrafine EGP and 1/5 dose of ultrafine EGP, respectively. The clinical efficacy of the three groups after one course of medication was comparatively analyzed. Results There were no significant differences in age, course of disease, symptom score before treatment, epigastric pain efficacy and syndrome curative effect among the three groups, the differences had no statistical significance (P>0.05). The severity, frequency and duration of epigastric pain were all reduced in the three groups, with significant differences between before and after treatment (P<0.05). Conclusion There are no significant differences in the clinical efficacy on epigastric pain among THD, 1/3 dose of ultrafine EGP and 1/5 dose of ultrafine EGP. In addition, the effect of 1/3 dose group is very close to the THD group.
2.Preparation and Release Rate in Vitro of Clomipramine Hydrochloride Sustained-release Tablets
Dongbo JIANG ; Xiaoli MA ; Dong HUANG ; Weiming CAI
China Pharmacy 2005;0(13):-
OBJECTIVE: To prepare clomipramine hydrochloride sustained release tablet and study its in vitro release rate.METHODS: Orthogonal experiment was carried out to optimize the formulation and the preparation was prepared taking by the formula dosage of HPMC,lactose and amylum pregelatinisatum as factors and the in vitro release rate as index.The in vitro drug release rate was investigated as well.RESULTS: The optimal formulation was as follows: HPMC 45 mg,lactose 35 mg,and amylum pregelatinisatum 40 mg.The preparation prepared in the optimal formulation had a sustained release of 24 h and the release behavior of the tablets followed the zero order equation.CONCLUSION: The formula of the sustained release tablets is reasonable and which had satisfactory sustained release efficacy.
3.Monocytes to high-density lipoprotein cholesterol ratio predicts the early neurological deterioration and outcome in patients with acute anterior circulation ischemic stroke
Jing ZHANG ; Jianhua ZHAO ; Jieyu BAO ; Mengmeng CAI ; Linlin CHAO ; Dongbo LIU
International Journal of Cerebrovascular Diseases 2022;30(10):738-744
Objective:To investigate the monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR) for the predictive value of early neurological deterioration (END) and poor outcome in patients with acute anterior circulation ischemic stroke (AACIS).Methods:Patients with AACIS admitted to Henan Provincial People's Hospital from January 2021 to January 2022 were included retrospectively. END was defined as the National Institutes of Health Stroke Scale (NIHSS) score within 7 d of onset increase ≥2 compred with baseline or the increase of motor function score ≥1. The patients were divided into END group and non-END group according to the presence or absence of END. The patients were also divided into good outcome group (0-2 points) and poor outcome group (3-6 points) according to the modified Rankin Scale score 3 months after onset. Multivariate logistic regression analysis was used to determine the independent risk factors for END and poor outcome, and the predictive value of MHR for END and poor outcome was evaluated by receiver operating characteristic (ROC) curve. Results:A total of 522 patients were enrolled, including 338 male (64.8%), aged 61.99±11.39 years old. One hundred and five patients (20.1%) had END, 123 (23.6%) had poor outcome. Multivariate logistic regression analysis showed that baseline NIHSS score (odds ratio [ OR] 1.075, 95% confidence interval [ CI] 1.017-1.137; P=0.010) and MHR (with the lowest quartile as the reference, the third quartile: OR 2.778, 95% CI 1.255-6.151, P=0.012; the fourth quartile: OR 12.645, 95% CI 5.942-26.912; P<0.001) were the independent risk factors for END; the baseline NIHSS score ( OR 1.075, 95% CI 1.021-1.132; P=0.006), END ( OR 2.306, 95% CI 1.010-6.261; P=0.047) and MHR (with the first quartile as reference, the fourth quartile: OR 2.769, 95% CI 1.167-6.569; P=0.021) were the independent risk factors for poor outcomes. ROC curve analysis showed that area under the curve of MHR for predicting END and poor outcome in patients with AACIS were 0.805 (95% CI 0.750-0.860; P<0.001) and 0.747 (95% CI 0.690-0.803; P<0.001) respectively. The best cutoff value was 0.435, the sensitivity was 73.3% and 64.2%, and the specificity was 79.6% and 78.7% respectively. The area under the curve of MHR for predicting END and poor outcome was higher than that of monocyte and HDL-C alone. Conclusion:MHR can be used as a predictor of END and poor outcome in patients with AACIS, and its predictive value is higher than that of monocytes or HDL-C.
4.Glycogen synthase kinase 3βinhibitor CHIR99021 induces human embryonic stem cells to differentiate into definitive endoderm cells
Cong DU ; Dongbo QIU ; Nan CAI ; Yabin WANG ; Yuan FENG ; Qi ZHANG ; Peng XIANG ; Huimin YI
Chinese Journal of Hepatic Surgery(Electronic Edition) 2014;(3):183-188
Objective To investigate the feasibility of glycogen synthase kinase (GSK) 3βinhibitor CHIR99021 induces human embryonic stem cells to differentiate into definitive endoderm cells. Methods Human embryonic stem cells H1 cells were cultured in feeder-free medium (Essential 8). The expression of human embryonic stem cell pluripotency markers Oct4, Nanog were detected by immunolfuorescence. Human embryonic stem cells were treated with CHIR99021 of different concentrations (0.33, 1.00, 3.00, 9.00, 27.00μmol/L) and cultured for 3 d respectively. The untreated cells were taken as control. The expression levels of pluripotency related genes OCT4, SOX2 and deifnitive endoderm related genes GATA4, SOX17 were detected by lfuorescent quantitative polymerase chain reaction (PCR). The experimental data were compared using one-way analysis of variance and LSD-t test. Results The expression of human embryonic stem cell pluripotency markers Oct4, Nanog could be detected by immunofluorescence. The human embryonic stem cells were observed in good growth when treated with CHIR99021 of different concentrations (0.33, 1.00, 3.00μmol/L) . The human embryonic stem cells were observed in poor growth or dead when treated with the higher concentrations of CHIR99021. The expression of pluripotency related gene OCT4 decreased after treated with CHIR99021 of 1.00, 3.00μmol/L concentration (LSD-t=-40.54,-59.12;P<0.05). The expression of SOX2 also decreased significantly (LSD-t=-20.46,-3.87;P<0.05). The expression of definitive endoderm related genes GATA4 increased after treated with CHIR99021 of 1.00, 3.00μmol/L concentration (LSD-t=137.21, 65.29;P<0.05). The expression of SOX17 also increased significantly (LSD-t=50.93, 6.56;P<0.05). Conclusions Human embryonic stem cells can maintain a good pluripotent state in the feeder-free culturing system. CHIR99021 can effectively induce the human embryonic stem cells to differentiate into deifnitive endoderm cells.
5.Influences of age-adjusted Charlson comorbidity index on prognosis of patients undergoing laparoscopic radical gastrectomy: a multicenter retrospective study
Zukai WANG ; Jianxian LIN ; Yanchang XU ; Gang ZHAO ; Lisheng CAI ; Guoxin LI ; Zekuan XU ; Su YAN ; Zuguang WU ; Fangqin XUE ; Yihong SUN ; Dongbo XU ; Wenbin ZHANG ; Peiwu YU ; Jin WAN ; Jiankun HU ; Xiangqian SU ; Jiafu JI ; Ziyu LI ; Jun YOU ; Yong LI ; Lin FAN ; Jianwei XIE ; Ping LI ; Chaohui ZHENG ; Changming HUANG
Chinese Journal of Digestive Surgery 2022;21(5):616-627
Objective:To investigate the influences of age-adjusted Charlson comorbidity index (ACCI) on prognosis of patients undergoing laparoscopic radical gastrectomy.Methods:The retrospective cohort study was conducted. The clinicopathological data of 242 gastric cancer patients who underwent laparoscopic radical gastrectomy in 19 hospitals of the Chinese Laparoscopic Gastrointestinal Surgery Study Group-04 study, including 54 patients in Fujian Medical University Union Hospital, 32 patients in the First Hospital of Putian City, 32 patients in Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 31 patients in Zhangzhou Affiliated Hospital of Fujian Medical University, 17 patients in Nanfang Hospital of Southern Medical University, 11 patients in the First Affiliated Hospital with Nanjing Medical University, 8 patients in Qinghai University Affiliated Hospital, 8 patients in Meizhou People′s Hospital, 7 patients in Fujian Provincial Hospital, 6 patients in Zhongshan Hospital of Fudan University, 6 patients in Longyan First Hospital, 5 patients in the First Affiliated Hospital of Xinjiang Medical University, 5 patients in the First Hospital Affiliated to Army Medical University, 4 patients in the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, 4 patients in West China Hospital of Sichuan University, 4 patients in Beijing University Cancer Hospital, 3 patients in the First Affiliated Hospital of Xiamen University, 3 patients in Guangdong Provincial People′s Hospital, 2 patients in the First Affiliated Hospital of Xi′an Jiaotong University, from September 2016 to October 2017 were collected. There were 193 males and 49 females, aged 62(range, 23?74)years. Observation indicators: (1) age distribution, comorbidities and ACCI status of patients; (2) the grouping of ACCI and comparison of clinicopathological characteristics of patients in each group; (3) incidence of postoperative early complications and analysis of factors affecting postoperative early complications; (4) follow-up; (5) analysis of factors affecting the 3-year recurrence-free survival rate of patients. Follow-up was conducted using outpatient examination or telephone interview to detect postoperative survival of patients up to December 2020. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3) or M(range), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was conducted using the nonparametric rank sum test. The X-Tile software (version 3.6.1) was used to analyze the best ACCI grouping threshold. The Kaplan-Meier method was used to calculate survival rates and draw survival curves. The Log-Rank test was used for survival analysis. The Logistic regression model was used to analyze the factors affecting postoperative early complications. The COX proportional hazard model was used for univariate and multivariate analyses of factors affecting the 3-year recurrence-free survival rate of patients. Multivariate analysis used stepwise regression to include variables with P<0.05 in univariate analysis and variables clinically closely related to prognosis. Results:(1) Age distribution, comor-bidities and ACCI status of patients. Of the 242 patients, there were 28 cases with age <50 years, 68 cases with age of 50 to 59 years, 113 cases with age of 60 to 69 years, 33 cases with age of 70 to 79 years. There was 1 patient combined with mild liver disease, 1 patient combined with diabetes of end-organ damage, 2 patients combined with peripheral vascular diseases, 2 patients combined with peptic ulcer, 6 patients combined with congestive heart failure, 8 patients combined with chronic pulmonary diseases, 9 patients with diabetes without end-organ damage. The ACCI of 242 patients was 2 (range, 0-4). (2) The grouping of ACCI and comparison of clinicopathological characteristics of patients in each group. Results of X-Tile software analysis showed that ACCI=3 was the best grouping threshold. Of the 242 patients, 194 cases with ACCI <3 were set as the low ACCI group and 48 cases with ACCI ≥3 were set as the high ACCI group, respectively. Age, body mass index, cases with preoperative comorbidities, cases of American Society of Anesthesiologists classification as stage Ⅰ, stage Ⅱ, stage Ⅲ, tumor diameter, cases with tumor histological type as signet ring cell or poorly differentiated adenocarcinoma and cases with tumor type as moderately or well differentiated adenocarcinoma, cases with tumor pathological T staging as stage T1, stage T2, stage T3, stage T4, chemotherapy cycles were (58±9)years, (22.6±2.9)kg/m 2, 31, 106, 85, 3, (4.0±1.9)cm, 104, 90, 16, 29, 72, 77, 6(4,6) in the low ACCI group, versus (70±4) years, (21.7±2.7)kg/m 2, 23, 14, 33, 1, (5.4±3.1)cm, 36, 12, 3, 4, 13, 28, 4(2,5) in the high ACCI group, showing significant differences in the above indicators between the two groups ( t=-14.37, 1.98, χ2=22.64, Z=-3.11, t=-2.91, χ2=7.22, Z=-2.21, -3.61, P<0.05). (3) Incidence of postoperative early complications and analysis of factors affecting postoperative early complications. Of the 242 patients, 33 cases had postoperative early complications, including 20 cases with local complications and 16 cases with systemic complica-tions. Some patients had multiple complications at the same time. Of the 20 patients with local complications, 12 cases had abdominal infection, 7 cases had anastomotic leakage, 2 cases had incision infection, 2 cases had abdominal hemorrhage, 2 cases had anastomotic hemorrhage and 1 case had lymphatic leakage. Of the 16 patients with systemic complications, 11 cases had pulmonary infection, 2 cases had arrhythmias, 2 cases had sepsis, 1 case had liver failure, 1 case had renal failure, 1 case had pulmonary embolism, 1 case had deep vein thrombosis, 1 case had urinary infection and 1 case had urine retention. Of the 33 cases with postoperative early complications, there were 3 cases with grade Ⅰ complications, 22 cases with grade Ⅱ complications, 5 cases with grade Ⅲa complications, 2 cases with grade Ⅲb complications and 1 case with grade Ⅳ complica-tions of Clavien-Dindo classification. Cases with postoperative early complications, cases with local complications, cases with systemic complications were 22, 13, 9 in the low ACCI group, versus 11, 7, 7 in the high ACCI group, respectively. There were significant differences in cases with postoperative early complications and cases with systemic complications between the two groups ( χ2=4.38, 4.66, P<0.05), and there was no significant difference in cases with local complications between the two groups ( χ2=2.20, P>0.05). Results of Logistic regression analysis showed that ACCI was a related factor for postoperative early complications of gastric cancer patients undergoing laparoscopic radical gastrectomy [ odds ratio=2.32, 95% confidence interval ( CI) as 1.04-5.21, P<0.05]. (4) Follow-up. All the 242 patients were followed up for 36(range,1?46)months. During the follow-up, 53 patients died and 13 patients survived with tumor. The 3-year recurrence-free survival rate of the 242 patients was 73.5%. The follow-up time, cases died and cases survived with tumor during follow-up, the 3-year recurrence-free survival rate were 36(range, 2-46)months, 29, 10, 80.0% for the low ACCI group, versus 35(range, 1-42)months, 24, 3, 47.4% for the high ACCI group. There was a significant difference in the 3-year recurrence-free survival rate between the two groups ( χ2=30.49, P<0.05). (5) Analysis of factors affecting the 3-year recurrence-free survival rate of patients. Results of univariate analysis showed that preoperative comorbidities, ACCI, tumor diameter, histological type, vascular invasion, lymphatic invasion, neural invasion, tumor pathological TNM staging, postoperative early complications were related factors for postoperative 3-year recurrence-free survival rate of gastric cancer patients undergoing laparoscopic radical gastrectomy [ hazard ratio ( HR)=2.52, 3.64, 2.62, 0.47, 2.87, 1.90, 1.86, 21.77, 1.97, 95% CI as 1.52-4.17, 2.22-5.95, 1.54-4.46, 0.27-0.80, 1.76-4.70, 1.15-3.12, 1.10-3.14, 3.01-157.52, 1.11-3.50, P<0.05]. Results of multivariate analysis showed that ACCI, tumor pathological TNM staging, adjuvant chemotherapy were indepen-dent influencing factors for postoperative 3-year recurrence-free survival rate of gastric cancer patients undergoing laparoscopic radical gastrectomy ( HR=3.65, 11.00, 40.66, 0.39, 95% CI as 2.21-6.02, 1.40-86.73, 5.41-305.69, 0.22-0.68, P<0.05). Conclusions:ACCI is a related factor for post-operative early complications of gastric cancer patients undergoing laparos-copic radical gastrectomy. ACCI, tumor pathological TNM staging, adjuvant chemotherapy are indepen-dent influencing factors for postoperative 3-year recurrence-free survival rate of gastric cancer patients undergoing laparoscopic radical gastrectomy.
6.Quality representation and correlation analytical study of Semen Cassiae based on phenolic characteristic architecture of medical system
Lu LIU ; Qian LI ; Deyong ZHOU ; Daohan SUN ; Dongbo LU ; Jing KONG ; Xiufen CAI ; Menglin WANG ; Qiuhong WU ; Wenxia LI ; Sitong LI ; Yuanyuan FAN ; Yujuan HUANG ; Xin FENG ; Renbing SHI
Journal of Beijing University of Traditional Chinese Medicine 2018;41(4):316-328
Objective To establish the quality representation and correlation analysis method and the content of characteristic ingredients based on spectrum of medicinal system of Juemingzi (Semen Cassiae),in order to evaluate the quality of Semen Cassiae decocting pieces effectively and accurately. Methods HPLC-PDA method was established to characterize the quality of spectrum of Semen Cassiae medicinal system architecture;quality of 11 batches of Semen Cassiae decocting pieces was characterized based on the number and chemical type of peaks on characteristic spectrum. The content of 6 characteristic index components, naphthopyrones and anthraquinones were characterized by indexes in characteristic spectrum. Correlation analysis of quality of Semen Cassiae was then performed with reference to the standard reference pieces. Results Taken as the reference substance, characteristic spectrum of batch 10 Semen Cassiae altogether contains 12 characteristic peaks, all characteristic peaks appeared on the chromatograms of 11 batches of Semen Cassiae. In 11 batches of Semen Cassiae, No.5, 11, 8, 1, 2 pieces contained higher effective index components, while No. 5, 11, 2, 9, and 7 pieces had high relevance with the reference piece (No. 10). Consolidated quality characterization and correlation analysis,the quality of No. 5,11,8,1,2,9,and 7 were excellent and dominant. Conclusion The HPLC method to analyze quality and quantity of phenolic components spectrum of 11 batches of Semen Cassiae is simple and accurate. The evaluation mode of quantity and quality and their correalation based on Semen Cassiae medical system, including systemic correlation and appilication validity, as it can provide a reliable methodological basis for the comprehensive quality evaluation of Semen Cassiae.
7.Efficient production of L-asparaginase in Bacillus licheniformis by optimizing expression elements and host.
Xinyuan YANG ; Yi RAO ; Mengxi ZHANG ; Jiaqi WANG ; Wenyuan LIU ; Dongbo CAI ; Shouwen CHEN
Chinese Journal of Biotechnology 2023;39(3):1096-1106
L-asparaginase (L-ASN) is widely applied in the treatment of malignant tumor and low-acrylamide food production, however, the low expression level hampers its application. Heterologous expression is an effective strategy to increase the expression level of target enzymes, and Bacillus is generally used as the host for efficient production of enzymes. In this study, the expression level of L-asparaginase in Bacillus was enhanced through optimization of expression element and host. Firstly, five signal peptides (SPSacC, SPAmyL, SPAprE, SPYwbN and SPWapA) were screened, among which SPSacC showed the best performance, reaching an activity of 157.61 U/mL. Subsequently, four strong promoters (P43, PykzA-P43, PUbay and PbacA) from Bacillus were screened, and tandem promoter PykzA-P43 showed the highest yield of L-asparaginase, which was 52.94% higher than that of control strain. Finally, three Bacillus expression hosts (B. licheniformis Δ0F3 and BL10, B. subtilis WB800) were investigated, and the maximum L-asparaginase activity, 438.3 U/mL, was reached by B. licheniformis BL10, which was an 81.83% increase compared with that of the control. This is also the highest level of L-asparaginase in shake flask reported to date. Taken together, this study constructed a B. licheniformis strain BL10/PykzA-P43-SPSacC-ansZ capable of efficiently producing L-asparaginase, which laid the foundation for industrial production of L-asparaginase.
Bacillus licheniformis/metabolism*
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Asparaginase/genetics*
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Bacillus/genetics*
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Protein Sorting Signals
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Promoter Regions, Genetic/genetics*
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Bacillus subtilis/genetics*
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Bacterial Proteins
8.Association of inflammatory indices with the severity of urinary sepsis: analysis of 70 cases.
Leming TAN ; Cheng YANG ; Xukai YANG ; Yangmin WANG ; Gaoping CAI ; Zhigang CAO ; Chuang HUANG ; Dongbo XU
Journal of Southern Medical University 2019;39(1):93-99
OBJECTIVE:
To analyze the association of the clinical inflammatory indices with the severity of urinary sepsis.
METHODS:
We reviewed the clinical data of 70 patients with urinary sepsis treated in our hospital between January, 2013 and April, 2018. All the patients were diagnosed in line with the Guidelines for Diagnosis and Treatment of Urological Diseases in China (2014 edition), including 22 patients with sepsis, 12 with hypotension and severe sepsis, 17 with septic shock, and 19 with critical septic shock. White blood cell count (WBC), neutrophil percentage (N%), platelets (PLT), fibrinogen (FIB), Ddimer, interleukin-6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) were examined in all the cases and compared among the 4 groups. The correlations of these inflammatory markers with the severity of sepsis were analyzed using logistic regression analysis.
RESULTS:
The 4 groups of patients showed significant differences in N%, PLT, D-dimer, and PCT ( < 0.05) but not in CRP (>0.05). Kruskal-Wallis Pairwise comparisons showed that the N% and PCT in patients with sepsis differed significantly from those in the other 3 groups; platelets in patients with sepsis differed significantly from those in patients with septic shock and critical septic shock; D-dimer differed significantly between patients with sepsis and those with septic shock. Among the 4 groups, the median levels of PLT decreased and PCT and N% increased with the worsening of sepsis. Logistic regression analysis indicated that PCT (=0.186, =0.000), N% (=0.047, =0.035) and PLT (=-0.012, =0.003) were significantly correlated with the severity of sepsis in these patients.
CONCLUSIONS
PCT, PLT and N% are all significantly correlated with the severity of sepsis, and their combined detection can be informative for assessing the severity of sepsis to facilitate clinical decisions on treatment.
Biomarkers
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blood
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C-Reactive Protein
;
analysis
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China
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Fibrin Fibrinogen Degradation Products
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analysis
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Fibrinogen
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analysis
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Humans
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Interleukin-6
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blood
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Leukocyte Count
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Platelet Count
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Procalcitonin
;
blood
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Sepsis
;
blood
;
diagnosis
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Severity of Illness Index
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Shock, Septic
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blood
;
diagnosis
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Statistics, Nonparametric
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Urinary Tract Infections
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diagnosis
9.Enhanced production of bacitracin via energy metabolism engineering in Bacillus licheniformis DW2.
Qing ZHANG ; Shan ZHU ; Naixiang CUI ; Bowen ZHANG ; Zhi WANG ; Xiaobin CHEN ; Jun LIU ; Junhui LI ; Dongbo CAI ; Zhifan YANG ; Shouwen CHEN ; Xin MA
Chinese Journal of Biotechnology 2020;36(6):1126-1137
Bacitracin is a broad-spectrum cyclic peptide antibiotic, and mainly produced by Bacillus. Energy metabolism plays as a critical role in high-level production of target metabolites. In this study, Bacillus licheniformis DW2, an industrial strain for bacitracin production, was served as the original strain. First, our results confirmed that elimination of cytochrome bd oxidase branch via deleting gene cydB benefited bacitracin synthesis. Bacitracin titer and ATP content were increased by 10.97% and 22.96%, compared with those of original strain, respectively. Then, strengthening cytochrome aa3 oxidase branch via overexpressing gene qoxA was conducive to bacitracin production. Bacitracin titer and ATP content were increased by 18.97% and 34.00%, respectively. In addition, strengthening ADP synthesis supply is also proven as an effective strategy to promote intracellular ATP accumulation, overexpression of adenosine kinase DcK and adenylate kinase AdK could all improve bacitracin titers, among which, dck overexpression strain showed the better performance, and bacitracin titer was increased by 16.78%. Based on the above individual methods, a method of combining the deletion of gene cydB and overexpression of genes qoxA, dck were used to enhance ATP content of cells to 39.54 nmol/L, increased by 49.32% compared to original strain, and bacitracin titer produced by the final strain DW2-CQD (DW2ΔcydB::qoxA::dck) was 954.25 U/mL, increased by 21.66%. The bacitracin titer produced per cell was 2.11 U/CFU, increased by 11.05%. Collectively, this study demonstrates that improving ATP content was an efficient strategy to improve bacitracin production, and a promising strain B. licheniformis DW2-CQD was attained for industrial production of bacitracin.
Bacillus licheniformis
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metabolism
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Bacitracin
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biosynthesis
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Energy Metabolism
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genetics
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Industrial Microbiology
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methods
10.Enhanced production of bacitracin by knocking out of amino acid permease gene yhdG in Bacillus licheniformis DW2.
Yang LI ; Fei WU ; Dongbo CAI ; Yangyang ZHAN ; Junhui LI ; Xiaobin CHEN ; Huichao CHEN ; Shouwen CHEN ; Xin MA
Chinese Journal of Biotechnology 2018;34(6):916-927
Bacitracin is a broad-spectrum polypeptide antibiotic, which is formed by 11 amino acids residues. Precursor amino acids supply might be the limit factor during bacitracin fermentation. First, our results demonstrated that increasing Ile and Leu supplies were regarded as the efficient strategies for the enhanced titer of bacitracin. Then, the amino acid permease YhdG, which was identified as the BCAA permease, was deleted and overexpressed in DW2, respectively. Our results showed that knocking out of permease YhdG could improve bacitracin production remarkablely. The bacitracin titer of the yhdG deficient strain DW2ΔyhdG reached 917.35 U/mL by flask fermentation, increased by 11% compared with that of DW2. In addition, the bacitracin titer was decreased by 25% in the YhdG overexpressed strain. Meanwhile, the intracellular concentrations of BCAA were higher than DW2 during the biosynthesis of bacitracin. The above results suggested that the permease YhdG might act as an exporter for branched chain amino acids in B. licheniformis DW2. Taken together, the increasing intracellular concentrations of branched chain amino acids by deleting amino acid permease YhdG could improve bacitracin titer. This study provided a new strategy for high-level production of bacitracin.