Through introducing mutations into ribosomes by obtaining spontaneous drug resistance of microorganisms, ribosome engineering technology is an effective approach to develop mutant strains that overproduce secondary metabolites. In this study, ribosome engineering was used to improve the yield of butenyl-spinosyns produced by Saccharopolyspora pogona by screening streptomycin resistant mutants. The yields of butenyl-spinosyns were then analyzed and compared with the parent strain. Among the mutants, S13 displayed the greatest increase in the yield of butenyl-spinosyns, which was 1.79 fold higher than that in the parent strain. Further analysis of the metabolite profile of S13 by mass spectrometry lead to the discovery of Spinosyn α1, which was absent from the parent strain. DNA sequencing showed that there existed two point mutations in the conserved regions of rpsL gene which encodes ribosomal protein S12 in S13. The mutations occurred a C to A and a C to T transversion mutations occurred at nucleotide pair 314 and 320 respectively, which resulted in the mutations of Proline (105) to Gultamine and Alanine (107) to Valine. It also demonstrated that S13 exhibited genetic stability even after five passages.
Genetic Engineering ; Macrolides ; metabolism ; Point Mutation ; Ribosomal Proteins ; genetics ; Ribosomes ; metabolism ; Saccharopolyspora ; metabolism

To improve spinosyn-producing strain and enhance spinosyns yield, we studied the effects of glycin concentration and the operational time, temperature and lysozyme concentration on protoplast preparation of Saccharopolyspora spinosa SP06081. We also studied different regeneration media and osmotic stabilizing agents. In addition, we compared the change of morphology and spinosyns yield of the regenerated strains. The results showed that the Saccharopolyspora spinosa SP06081 protoplast yield was the highest under these conditions: the collected mycelium from SP06081 grown in Tryptic Soy Broth (TSB) medium with 0.2% glycin for 48 h was treated by 0.1 mg/mL lysozyme at 28 degrees C for 20 min, then plated on the R2YE medium with sucrose as osmotic stabilizer, the number of regeneration protoplast was up to 10(8)/mL. The protoplast-regenerated strains exhibited changes in morphology and antibiotic production, 29.3% protoplast-regenerated strains was characterized by loose mycelium and abundant broken branches as did their parent. Among them, 58.2% strains presented the trend to positive variation in spinosad yield, with the highest spinosad yield of up to 582.0 mg/L, 85.6% higher than that of their parent. There is significant correlation between the morphological differentiation and antibiotic yield of the protoplast-regenerated strains from spinosyn-producing strain.
Culture Media ; pharmacology ; Drug Combinations ; Glycine ; pharmacology ; Insecticides ; metabolism ; Macrolides ; metabolism ; Muramidase ; pharmacology ; Protoplasts ; cytology ; drug effects ; Regeneration ; Saccharopolyspora ; genetics ; metabolism ; physiology

BACKGROUNDGensing Rg3 is an active component from ginseng. The aim of this study is to observe the clinical anticancer effect of Rg3 in combination with chemotherapy regimen NP (vinorelbine+cisplatin) in advanced non-small cell lung cancer (NSCLC).

METHODSStage III-IV NSCLC patients confirmed by pathology or cytology all received vinorelbine plus cisplatin for at least two cycles, and were randomized into two groups: patients in arm A also received placebo twice a day, while patients in arm B received two tablets of Rg3 twice a day for at least two months. The endpoints of the study were the efficacy, survival and tolerance of patients.

RESULTSFrom July 2000 to May 2002, 115 patients were enrolled into the trial. The patients' characteristics were well balanced in the two groups. Sex of patients: male, 79; female 36. Types of pathology: adenocarcinoma, 71; squamous cell carcinoma, 29; adenosquamous carcinoma, 8; others, 7. TNM stage: stage III, 45; stage IV, 70. Prior chemotherapy: with, 17; without, 98. Prior radiotherapy: with, 15; without, 100. Prior surgical treatment: with, 23; without, 92. Nine patients discontinued from the trial due to severe adverse effects (5) and other reasons (4), so there were 106 patients evaluable for clinical efficacy. The response rate was 14.5% (8/55) in arm A, and 33.3% (17/51) in arm B (P=0.011). The survival time in arm A was 9.7 months (mean) and 8.0 months (median), and 15.3 months (mean) and 10.0 months (median) in arm B (P=0.0088).

CONCLUSIONSPreliminary results show improvements in response rate and survival time (median and mean) in Rg3 arm compared with placebo arm. It is worthy to confirm the results in further clinical trials.

Objective To discuss the application of shear wave elastography and strain elasticity imaging diagnosis of infants with congenital muscular torticollis. Methods Children with congenital muscular torticollis in 50 patients and 100 healthy infants were recruited for the research at Shezhen Children′s Hospital in the period of September to December, analyzing factors in normal sternocleidomastoid two mode ultrasonic elastography, including the young′s modulus, shear wave velocity, shear modulus and the ratio of strain results, comparing the change of elasticity between the patients and normal. Results The elastic parameters of the sternocleidomastoid showed no statistically significant difference between the genders, the left side and the right side. The results of young′s modulus, shear wave velocity and shear wave modulus were higher in long axis section than the short axis section, and the difference was statistically significant (P<0.05). However, the results of the strain ratio and thickness was not statistically significant. The young′s modulus, shear wave velocity and shear wave modulus are higher in the stretch back position than symmetrical supine position, and the difference is statistically significant (P<0.05). But those of strain ratio and thickness was not statistically significant. The thickness of the sternocleidomastoid muscle and the young′s modulus, shear wave velocity, shear modulus and the ratio of strain results ultrasound elastic results were higher in the lesion side than the healthy side, and the difference is statistically significant (P<0.05). Conclusion The ultrasound elastic imaging of multimodal technique can quantify the elasticity of the normal infant and the patients sternocleidomastoid, be used for diagnose for the infants with the congenital muscular torticollis.

Objective:To understand the degree of professional autonomy of nurses in Pediatric Nursing Alliance and the status of pediatric nursing practice environment, which providing guidance for the development of a series of specialized training in the alliance.Methods:Stratified random sampling method was used to conduct a questionnaire survey on nursing staff of different professional levels in Pediatric Nursing Alliance, which through the questionnaire star by using the questionnaire general information and training demand questionnaire, nurses practice professional autonomy scale, pediatric nursing staff structural empowerment questionnaire and nursing practice influencing factors questionnaire through the questionnaire star.Results:The total score for professional autonomy of nurses in the pediatric alliance was 192.66±18.63, the structural empowerment ( OR=1.137, 95% CI=1.084-1.194), lack of caring team ( OR=2.763, 95% CI=1.443-5.292) and performance evaluation ( OR=0.498, 95% CI= 0.274-0.908), specialized education and professional experience ( OR=0.548, 95% CI= 0.334-0.871) were affecting the clinical nursing practice. Conclusion:The degree of professional autonomy of nurses in the Pediatric Nursing Alliance is in the middle and high level. Key factors affecting nursing practice including insufficient structural empowerment, lack of opportunities to continue learning, lack of nursing teams, lack of effectiveness evaluation and the lack of specialized education and work experience, which guiding the pediatric nursing alliance to continuously deepen the connotation of pediatric nursing professional and innovative team collaboration new model, utilize the advantages of resources to actively cultivate specialized nursing research personnel, carry out multi-disciplinary and cross-disciplinary cooperation, improve the nursing quality evaluation index system, so as to enhance the professional nursing service capacity and value.

Objective: To evaluate the antimicrobial activity of nonequilibrium plasma against Enterococcus faecalis (Ef) biofilms in vitro and to obtain novel evidence of root canal disinfection with nonequilibrium plasma. Methods: Sterile cover slips and single-rooted canals were filled with Ef and incubated to form 1-week-old and 3-week-old biofilms, respectively. The infected samples were subjected to nonequilibrium plasma, 2% chlorhexidine digluconate (CHX) and saline for 3, 10 and 30 minutes, respectively. After treatment, the killing effectiveness of nonequilibrium plasma was analyzed by using laser scanning confocal microscopy (LSCM) and colony forming unit (CFU) counting. Results: The 3-dimentional reconstruction LSCM images showed that about 48.3%-79.8% of 1-week-old Ef biofilm cells and 40.0%-67.4% of 3-week-old biofilm cells were killed by nonequilibrium plasma and 2% CHX compared to saline (P<0.05). The proportion of killing activity was lower after 3 minutes (40.0%-50.9% killing) than after 10 minutes (65.3%-77.8% killing) and 30 minutes (66.4%-79.8% killing) (P<0.05). And the killing of biofilm bacteria was fastest during the first 3 minutes (13.3%-17.0% killing per minute) and slow down greatly after 10 minutes. Remarkably more bacteria were killed in 1-week-old Ef biofilms (48.3%-79.8% killing) than in 3-week-old biofilms (P<0.05). Conclusions The nonequilibrium plasma killed more Ef biofilm cells in infected root canals showed promotional as an additional approach against bacterial biofilms during root canal disinfection.

Objective: To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro. Methods: Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test. Results: After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05). Conclusions The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

Objectives: To propose a novel clinical classification system of gallbladder cancer, and to investigate the differences of clinicopathological characteristics and prognosis based on patients who underwent radical resection with different types of gallbladder cancer. Methods: The clinical data of 1 059 patients with gallbladder cancer underwent radical resection in 12 institutions in China from January 2013 to December 2017 were retrospectively collected and analyzed.There were 389 males and 670 females, aged (62.0±10.5)years(range:22-88 years).According to the location of tumor and the mode of invasion,the tumors were divided into peritoneal type, hepatic type, hepatic hilum type and mixed type, the surgical procedures were divided into regional radical resection and extended radical resection.The correlation between different types and T stage, N stage, vascular invasion, neural invasion, median survival time and surgical procedures were analyzed.Rates were compared by χ² test, survival analysis was carried by Kaplan-Meier and Log-rank test. Results: Regional radical resection was performed in 940 cases,including 81 cases in T1 stage,859 cases in T2-T4 stage,119 cases underwent extended radical resection;R0 resection was achieved in 990 cases(93.5%).The overall median survival time was 28 months.There were 81 patients in Tis-T1 stage and 978 patients in T2-T4 stage.The classification of gallbladder cancer in patients with T2-T4 stage: 345 cases(35.3%)of peritoneal type, 331 cases(33.8%) of hepatic type, 122 cases(12.5%) of hepatic hilum type and 180 cases(18.4%) of mixed type.T stage(χ²=288.60,P<0.01),N stage(χ²=68.10, P<0.01), vascular invasion(χ²=128.70, P<0.01)and neural invasion(χ²=54.30, P<0.01)were significantly correlated with the classification.The median survival time of peritoneal type,hepatic type,hepatic hilum type and mixed type was 48 months,21 months,16 months and 11 months,respectively(χ²=80.60,P<0.01).There was no significant difference in median survival time between regional radical resection and extended radical resection in the peritoneal type,hepatic type,hepatic hilum type and mixed type(all P>0.05). Conclusion With application of new clinical classification, different types of gallbladder cancer are proved to be correlated with TNM stage, malignant biological behavior and prognosis, which will facilitate us in preoperative evaluation,surgical planning and prognosis evaluation.