Advances in several important antimicrobial lipopeptids from Bacillus spp / 生物工程学报

Bacillus spp. are probiotics and can secrete a variety of natural antimicrobiol active substances, of which lipopeptides are an important class. Up to now, about 90 lipopeptides have been identified, and most of them are cyclic lipopeptides. surfactin, iturin, fengycin, bacillomycin and polymyxins are widely studied, and the first three have huge potential for application due to their properties of surfactants and anti-fungal, anti-bacterial, anti-viral, anti-tumor and anti-inflammatory functions. In this paper, the research progress in the structure, function, synthesis regulation, separation, purification and production of surfactin, iturin and fengycin was reviewed. Synthetic biology is a vital means to increase the yield of lipopeptides, and in the future, lipopeptides can be used in crop cultivation, animal farming, food, medicine and petroleum industries as well as environmental protection. Future research should be strengthened on the discovery of new lipopeptides, synthesis of high-activity lipopeptides, economical production of lipopeptides on a large scale and their safety evaluation.

Three-column scoring system for postoperative X-ray stability of intertrochanteric fracture after intramedullary nailing / 中华创伤骨科杂志

Objective:To evaluate the clinical significance of our self-designed three-column scoring system for postoperative X-ray stability of intertrochanteric fracture after intramedullary nailing.Methods:A retrospective study was conducted of the 378 patients with intertrochanteric fracture who had been treated between January 2015 and June 2019 at Department of Orthopaedics, Linyi People's Hospital by internal fixation with proximal femoral nail antirotation (PFNA). They were 161 males and 217 females, aged from 60 to 97 years (average, 72.5 years). By the AO classification, there were 109 cases of type 31-A1, 188 cases of type 31-A2 and 81 cases of type 31-A3. Anteroposterior and lateral X-ray examinations of the hip were performed immediately after internal fixation to evaluate the fracture stability using our self-designed three-column scoring system by which the medial column is given 4 points, middle column 2 points and lateral column 2 points. A single column scoring full points is rated as stable, 3-column stability as excellent, 2-column stability as good, one-column stability as fair, and 3-column unstability as poor. Rehabilitation programs were carried out according to the results of stability evaluation: full weight bearing at an early stage was indicated for excellent patients, partial weight bearing at an early stage for good patients and weight bearing at an early stage contraindicated for fair or poor patients. Fracture union time and failure of internal fixation were recorded. The relationship between internal fixation failure and our three-column scoring system was calculated.Results:The 378 patients were followed up for 6 to 24 months (mean, 10.4 months). Of them, 365 obtained fracture union after an average time of 4.3 months (from 3 to 7 months). Internal fixation failure occurred in 13 patients, giving a failure rate of 3.4%(13/378).Of the 129 excellent patients by our three-column scoring system for post-operative X-ray stability of intertrochanteric fracture, none failed in internal fixation; of the 193 good patients, 4 failed; of the 56 fair patients, 9 failed. Internal fixation failure was closely related to our three-column scoring system for postoperative X-ray stability of intertrochanteric fracture ( r=-0.986, P=0.006), as well as to the column stability ( r=-1.000, P=0.033). Conclusion:Our self-designed three-column scoring system for postoperative X-ray stability of intertrochanteric fracture after intramedullary nailing can accurately reflect the fracture stability so that it can be used to guide rehabilitation programs for the patients and judge their prognosis.

Effect of cyclosporin A on the proliferation activity of mesenchymal stem cells / 白血病·淋巴瘤

Objective To provide data for reference on the impact of cyclosporin A (CsA) on the proliferation of the bone marrow mesenchymal stem cells in MDS patients through the investigation of the impact of cyclosporin A on human bone marrow mesenchymal stem cell proliferation. Methods The absorption rates of the bone marrow mesenchymal stem cells in the control group and the MDS patient group were determined by using the tetrazolinm salt (MTT) micro-colorimetric enzyme reaction. The concentrations of cyclosporine A are 2.5×10~4 ng/μl, 2.5×10~3 ng/μl, 2.5×10~2 ng/μl and 2.5×10ng/μl respectively. Results There is no significant difference between the each result by using different concentrations of CsA., which indicates the impact of CsA on the growth of mesenchymal stem cells is not significant(P >0.05). In the serial of concentrations mentioned, no cytotoxicity of CsA is observed. However, there is difference between the selected indicators of the control group and the patient group (P 0.05). There is no significant difference between the absorption rates of the group treated by CsA of every concentration and the corresponding control group. Conclusion The impact of CsA on the bone marrow mesenchymal stem cell proliferation is significant in neither healthy people nor MDS patients.