Objective The Toxicology study of Tibetan medicine MNXT granules was observed to provide basis for clinical safe medication.Methods The acute toxicity test in mice was conducted with the oral maximum-tolerated dosage,and then toxicity reaction and death situations in mice at 14d after the intragastric administration (ig) one day at 3 times was observed; Long-term toxic test:the does of MNXT granule 13.23 g/kg · d-1,6.667 g/kg· d-1,3.33 g/kg· d-1 (equivalent 100,50,25 times of the clinical dosage) were continuous administered to medicating groups for 30 days,and blank group was given distilled water instead.The rats'behavior,appearance,food intake,water intake,body weight were observed,and the blood,blood biochemical parameters,the main organ coefficient,anatomical,pathological morphology were determined at 30d after administration and 15d after withdrawal.Results The maximum study medication dose of Tibet an medicine MNXT granule was 39 g/kg (equivalent to 300 times the clinical dose) and the mice had not any adverse reaction.Long-term toxicity test:the rats' blood and blood biochemical parameters,the main organ coefficient,anatomical,pathological morphology had not significant differences compared with the blank grou? during the 30d administration and 15d withdrawal.Conclusion Toxicity of the Tibetan medicine MNXT granules was not observed in acute or long-term toxicity test.

In the aromatic amino acid biosynthetic pathway 3-dehydroshikimate (DHS) is a key intermediate. As a potent antioxidant and important feedstock for producing a variety of important industrial chemicals, such as adipate and vanillin, DHS is of great commercial value. Here, in this study, we investigated the effect of the co-expression of aroFFBR (3-deoxy-D-arabino-heptulosonate 7-phosphate synthase mutant with tyrosine feedback-inhibition resistance) and tktA (Transketolase A) at different copy number on the production of DHS. The increased copy number of aroFFBR and tktA would enhance the production of DHS by the fold of 2.93. In order to further improve the production of DHS, we disrupted the key genes in by-product pathways of the parent strain Escherichia coli AB2834. The triple knockout strain of ldhA, ackA-pta and adhE would further increase the production of DHS. The titer of DHS in shake flask reached 1.83 g/L, 5.7-fold higher than that of the parent strain E. coli AB2834. In 5-L fed-batch fermentation, the metabolically engineered strain produced 25.48 g/L DHS after 62 h. Metabolically engineered E. coli has the potential to further improve the production of DHS.
3-Deoxy-7-Phosphoheptulonate Synthase ; genetics ; Amino Acids, Aromatic ; biosynthesis ; Biosynthetic Pathways ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Metabolic Engineering ; Shikimic Acid ; analogs & derivatives ; metabolism ; Transketolase ; genetics

Rhamnolipid biosurfactant is mainly produced by Pseudomonas aeruginosa that is the opportunistic pathogenic strain and not suitable for future industrial development. In order to develop a relatively safe microbial strain for the production of rhamnolipid biosurfactant, we constructed engineered Escherichia coli strains for rhamnolipid production by expressing different copy numbers of rhamnosyltransferase (rhlAB) gene with the constitutive synthetic promoters of different strengths in E. coli ATCC 8739. We further studied the combinatorial regulation of rhlAB gene and rhaBDAC gene cluster for dTDP-1-rhamnose biosynthesis with different synthetic promoters, and obtained the best engineered strain-E. coli TIB-RAB226. Through the optimization of culture temperature, the titer of rhamnolipd reached 124.3 mg/L, 1.17 fold higher than that under the original condition. Fed-batch fermentation further improved the production of rhamnolipid and the titer reached the highest 209.2 mg/L within 12 h. High performance liquid chromatography-mass spectrometry (LC-MS) analysis showed that there are total 5 mono-rhamnolipid congeners with different nuclear mass ratio and relative abundance. This study laid foundation for heterologous biosynthesis of rhanomilipd.
Bacterial Proteins ; genetics ; Batch Cell Culture Techniques ; Decanoates ; Escherichia coli ; metabolism ; Fermentation ; Glycolipids ; biosynthesis ; Hexosyltransferases ; genetics ; Industrial Microbiology ; methods ; Multigene Family ; Promoter Regions, Genetic ; Pseudomonas aeruginosa ; Rhamnose ; analogs & derivatives ; biosynthesis ; Surface-Active Agents ; metabolism

OBJECTIVETo explore the feasibility of short-term neoadjuvant chemotherapy (NACT) in patients with advanced gastric cancer (AGC), and to compare clinical efficacy of short-term neoadjuvant chemotherapy with different ways.

METHODSClinical data of 310 AGC patients treated with one course of NACT using EOF regimen(epirubicin, oxaliplatin and fluorouracil plus calcium folinate) in our hospital from January 2008 to December 2011 were retrospectively analyzes. Efficacy was compared between regional arterial infusion chemotherapy and intravenously chemotherapy.

RESULTSAll the 310 AGC patients completed one course of NACT and none was interrupted by adverse events. Postoperative pathological remission rate was 33.9% (105/310) and 5 patients (1.6%) had complete pathological remission. The pathologic response rate in the regional arterial infusion chemotherapy group was higher than that in the intravenously chemotherapy group(42.4% vs. 23.6%, P = 0.001). Multivariate analysis revealed that chemotherapy method(HR=1.827, 95% CI:1.006-3.316, P = 0.048) was associated with significantly higher pathologic response.

CONCLUSIONSPathological response rate is quite low following short-term NACT. Regional arterial infusion chemotherapy with short-term NACT can improve the pathological response rate of advanced gastric cancer.

Antineoplastic Combined Chemotherapy Protocols ; administration & dosage ; therapeutic use ; Epirubicin ; Fluorouracil ; Humans ; Infusions, Intra-Arterial ; Leucovorin ; Neoadjuvant Therapy ; Organoplatinum Compounds ; Remission Induction ; Retrospective Studies ; Stomach Neoplasms ; drug therapy

Objective To assess the dosimetric benefit,prognosis and toxicity of intensitymodulated radiation therapy (IMRT) for stage Ⅲ esophageal squamous cell cancer.Methods This was a retrospective analysis of 28 patients,aged between 45 and 83 years,with stage Ⅲ esophageal squamous cell cancer who had received radical IMRT.Of these patients,six received concurrent chemotherapy and eight received targeted therapy.The median radiotherapy dose was 67.1 Gy.Dosimetric parameters for the target volume and critical normal structures were evaluated by dose volume histogram.The Kaplan-Meier method was used to calculate overall survival (OS),progress free survival (PFS) and locoregional control (LRC).Results The mean conformity index (CI) and homogeneity index (HI) scores of the planning target volume (PTV) were 0.82 and 0.92,respectively,indicating very good coverage of the target volume.Three-year OS,PFS,and LRC were 48.0 ％,31.2％,and 62.0％,respectively.Acute toxicities were mild,only two patients developed acute esophagitis (grade ≥3),and three had acute pneumonitis (grade ≥2).Conclusions IMRT can provide excellent dose conformity and achieve favorable LRC and survival with only mild toxicities in patients with stage Ⅲ esophageal squamous cancer.

Cases of 2019-nCoV nucleic acid and antibody (IgM and IgG total antibody) after discharge from a hospital in Chongqing were continuously monitored. It was found that 5 cases of "re-positive" phenomenon, 5 cases of antibody were positive, and there was a trend of increasing with time. "Re-Positive" may be related to the following three factors. Children with asymptomatic infection had a long time of fecal detoxification.There were two consecutive nucleic acid tests "false negative" caused by various reasons.The virus clearance in patients was not complete, and the discharge standard was not conservative enough. The analysis of the causes of "Re-Positive" patients and the discussion of its infection will help us reveal more characteristics of this virus, and to provide a new basis for the discharge standard in the constantly updated diagnosis and treatment programme.

Objective To summarize current status of multidrug-resistant organism (MDRO) infection in lung transplant recipients and analyze the risk factors of MDRO infection. Methods Clinical data of 321 lung transplant recipients were retrospectively analyzed. According to the incidence of postoperative MDRO infection, they were divided into the MDRO group (n=122) and non-MDRO infection group (n=199). The incidence of MDRO infection in lung transplant recipients was summarized. The risk factors of MDRO infection in lung transplant recipients were analyzed by logistic regression model. The dose-response relationship between MDRO infection and time of ventilator use was determined by restricted cubic spline model. Results Among 321 lung transplant recipients, 122 cases developed MDRO infection, with an infection rate of 38.0%. Two hundred and twenty-nine strains of pathogenic bacteria were detected in the MDRO infection group, mainly Gram-negative bacteria (92.6%), and the top three strains were carbapenem-resistant acinetobacter baumannii (46.3%), carbapenem-resistant pseudomonas aeruginosa (22.3%) and carbapenem-resistant klebsiella pneumoniae (14.8%), respectively. MDRO infection mainly consisted of lower respiratory tract infection (61.5%), followed by ventilator-associated pneumonia (26.2%). Univariate analysis showed that the risk factors of MDRO infection in lung transplant recipients were single-lung transplantation, long-time postoperative use of extracorporeal membrane oxygenation (ECMO), long operation time, long-time urinary catheterization, long-time central venous catheterization and long-time ventilator use (all P < 0.05). Multivariate logistic regression analysis indicated that single-lung transplantation and long-time ventilator use were the independent risk factors for MDRO infection in lung transplant recipients (both P < 0.05). Results of restricted cubic spline model analysis showed that the risk of infection continued to increase with the prolongation of ventilator use time within 20 d. After 20 d, prolonging the time of ventilator use failed to increase the risk of infection, showing a plateau effect. Conclusions The MDRO infection rate tends to decline in lung transplant recipients year by year. Single-lung transplantation and long-time ventilator use are the independent risk factors for MDRO infection in lung transplant recipients.

p-coumaric acid is one of the aromatic compounds that are widely used in food, cosmetics and medicine due to its properties of antibacterium, antioxidation and cardiovascular disease prevention. Tyrosine ammonia-lyase (TAL) catalyzes the deamination of tyrosine to p-coumaric acid. However, the lack of highly active and specific tyrosine ammonia lyase limits cost-effective microbial production of p-coumaric acid. In order to improve biosynthesis efficiency of p-coumaric acid, two tyrosine ammonia-lyases, namely Fc-TAL2 derived from Flavobacterium columnare and Fs-TAL derived from Flavobacterium suncheonense, were selected and characterized. The optimum temperature (55 ℃) and pH (9.5) for Fs-TAL and Fc-TAL2 are the same. Under optimal conditions, the specific enzyme activity of Fs-TAL and Fc-TAL2 were 82.47 U/mg and 13.27 U/mg, respectively. Structural simulation and alignment analysis showed that the orientation of the phenolic hydroxyl group of the conserved Y50 residue on the inner lid loop and its distance to the substrate were the main reasons accounting for the higher activity of Fs-TAL than that of Fc-TAL2. The higher activity and specificity of Fs-TAL were further confirmed via whole-cell catalysis using recombinant Escherichia coli, which could convert 10 g/L tyrosine into 6.2 g/L p-coumaric acid with a yield of 67.9%. This study provides alternative tyrosine ammonia-lyases and may facilitate the microbial production of p-coumaric acid and its derivatives.
Ammonia-Lyases/chemistry* ; Coumaric Acids ; Escherichia coli/genetics* ; Tyrosine

Objective To compare the therapeutic effects between three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in patients with stage Ⅱ/Ⅲ esophageal cancer and investigate the prognostic factors.Methods Medical record of 2 132 patients with stage Ⅱ/Ⅲ esophageal cancer who underwent definitive radiotherapy with/without chemotherapy in 10 hospitals from January 2002 to December 2016 from were retrospectively analyzed.Among these patients,37.9％ of them were aged ≥ 70 years,33.9％ with neck and upper esophageal tumors and 66.1％ with middle and lower esophageal and borderline tumors.The median gross tumor volume (GTV) and lymph node gross tumor volume (GTVnd) was 41.6 cm3.Among them,32％ were stage Ⅱ] and 68％ were stage Ⅲ.A total of 723 patients received 3DCRT and 1 409 cases received IMRT.Patients received an equivalent dose in 2 Gy (EQD2) ≥ 60 Gy accounted for 86.1％,and 41.1％ of them received concurrent chemoradiotherapy.Results The median follow-up time was 60.8 months.The 1-,3-and 5-year overall survival (OS) of all patients was 73.9％,41.7％ and 32.6％,and the 1-,3-and 5-year progression-free survival (PFS) was 62.2％,37.3％ and 32％,respectively.Multivariate analysis demonstrated that age,primary tumor location,clinical stage,tumor target volume,EQD2 and concurrent chemoradiotherapy were the independent prognostic factors for OS.Age,primary tumor location,clinical stage,tumor target volume and EQD2 were the independent prognostic factors for PFS.The OS and PFS did not significantly differ among the low-risk,low-/moderate-risk,moderate-/high-risk and high-risk groups according to age≥70 years,tumor diameter＞5 cm,tumor volume ≥41.6 cm3 and stage Ⅲ (P＜0.001).After the propensity score matching (PSM) method,neither 3DCRT nor IMRT yielded significant advantages in OS or PFS (P=0.971;P=0.658).However,IMRT tended to yield survival benefits in low-risk patients (P=0.125).Conclusions Both 3DCRT and IMRT yield relatively high OS rate in patients with stage Ⅱ/Ⅲ esophageal cancer.The prognosis model established in this investigation can properly predict the survival of patients.Low-risk patients tend to obtain survival benefits from IMRT.

Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.
Adipates ; metabolism ; Bacteria ; genetics ; metabolism ; Fungi ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; methods ; Metabolic Networks and Pathways ; genetics