AIM To study the hemolyzation of a highly active anti complementary protein (cobra venom factor, CVF) isolated from the venom of Naja kaouthia distributed in the south of Yunnan Province, China. METHODS Guinea pig red blood cell and serum were employed to evaluate the hemolyzation of this anticomplement factor, and the effects of temperature, pH, various bivalent mental ions and EDTA on its hemolyzation were investigated. RESULTS This anticomplement factor possessed hemolytic activity of 1 391 kU?g -1 protein. It showed high stability to heat, alkalinity and acidity. Ca 2+ , Mg 2+ , Mn 2+ promoted the hemolyzation of this anticomplement factor at 1, 2 and 5 mmol?L -1 . Zn 2+ , Co 2+ also promoted the hemolyzation of this anticomplement factor at 1 and 2 mmol?L -1 , but inhibited the hemolyzation at 5 mmol?L -1 . Cu 2+ strongly inhibited the hemolyzation at 1, 2 and 5 mmol?L -1 . EDTA also strongly inhibited the hemolyzation of this anticomplement factor. CONCL- USION The anticomplement factor showed hemolytic activity. This ability could be influenced by bivalent metal ions and EDTA, but rather stable when temperature or pH value changed.

Extracellular vesicles (EVs) are vesicles like body of phospholipid bilayer membrane, which are able to mediate the transfer of genetic material. There are receptors, proteins and nucleic acids in the body, with carrying tumor genetic material, regulating tumor microenvironment, promoting tumor angiogenesis and mediating tumor cell metastasis. At present, it is found that there is a close re-lationship between the secretion and the metastasis of lung cancer. The main aspects of the brain metastasis of the lung cancer medi-ated by the exocrine body include the regulation of the microenvironment of the brain, the destruction of the blood-brain barrier, and the regulation of tumor cell pathology. The study on the relationship between the tumor and the metastasis of lung cancer may pro-vide more molecular targets for the development, diagnosis and treatment of lung cancer.

BACKGROUND:The biological function of human periodontal ligament stem cells is a hot area of research in the treatment of periodontal disease. Human periodontal ligament cells are one of the end cells derived from human periodontal ligament stem cells;meanwhile, it can also provide supports to the development of human periodontal ligament stem cells. However, few studies are reported about the difference of biological characteristics between human periodontal ligament stem cells and human periodontal ligament cells. OBJECTIVE:To compare the differences of biological characteristics between human periodontal ligament stem cells and human periodontal ligament cells. METHODS:The human periodontal ligament stem cells and human periodontal ligament cells were isolated and purified using tissue explant method and cellclone method, respectively, and then were observed under light microscope to compare the differences of morphology. cellproliferation curves of human periodontal ligament stem cells and human periodontal ligament cells were drawn respectively with cellcounting kit 8 assay. Flow cytometry analysis was used to detect their cellcircles and their surface markers expressions. The alkaline phosphatase gene, proliferating cellnuclear antigen gene and Scleraxis gene of human periodontal ligament stem cells and human periodontal ligament cells were detected by Real-time PCR assay.RESULTS AND CONCLUSION:The human periodontal ligament stem cells and human periodontal ligament cells showed a notable difference in morphology under the light microscope observation. During the first 5 days, the cellproliferation curve of human periodontal ligament stem cells was lower than that of human periodontal ligament cells, but 5 days later, the curve of human periodontal ligament stem cells was significantly higher than that of human periodontal ligament cells. The cellcircles of human periodontal ligament stem cells and human periodontal ligament cells were 41.1%and 23.9%, respectively. The surface markers of human periodontal ligament stem cells and human periodontal ligament cells were similar, but their expression rates had significant difference. The expressions of alkaline phosphatase gene, proliferating cellnuclear antigen gene and Scleraxis gene of human periodontal ligament stem cells were significantly higher than those of human periodontal ligament cells. The above results suggest that human periodontal ligament stem cells have much stronger potential ability than human periodontal ligament cells in osteogensis and cellproliferation.

Objective:To analyze the morphological characteristics of maxillary first molars,mesiobuccal roots and the incidence of second mesiobuccal(MB2)roots in Uyghur adults.Methods:1 00 Uyghur adults with full dentition were included.The morphology of maxillary first molars and root canals were examined by cone beam computerized tomography(CBCT).The prevalence of MB2 and the difference between sexes were analysed.Results:Among 200 maxillary first molars,1 54(77%)teeth were with 3 roots and 3 ca-nals,42(21 %)with 3 roots and 4 canals,2(1 %)with 3 roots and 5 canals,1 (0.5%)was with 4 roots and 6 canal,1 (0.05%) with 4 roots and 7 canal.The percentage of type Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ mesiobuccal roots was 77.0,1 3.5,9.0,0 and 0.5 respec-tively.The prevalence of MB2 was 22.32% in male and 21 .2% in female(P =0.901 ).Conclusion:The prevalence of MB2 in Uy-ghur adults is about 22% and the predominant morphology of maxillary first molarsmesiobuccal roots was type I.

Objective To evaluate the feasibility and significance of CT image-based threedimensional (3D) brachytherapy for cervical cancer.Methods Three-dimensional (3D) plan and twodimensional (2D) plan were designed for 55 CT images of brachytherapy from 12 cervical cancer patients who received radical radiotherapy in 2013.Dosimetric comparison was performed between the 3D plan and 2D plan,and paired t-test,Wilcoxon signed rank test,Pearson correlation analysis,and Spearman correlation analysis were performed.Results A point dose,D90,V100,CI,and CI' in 3D plan were higher than those in 2D plan (P=0.015,0.016,0.000,0.000,0.000).Bladder point dose,rectal point dose,and rectal D2 cm3 in 3D plan were slightly higher than those in 2D plan,but hot spot dose was significantly reduced in 3D plan (P =0.140,0.123,0.214).Bladder D2cm3 was significantly higher than bladder point dose (P =0.000).Sigmoid colon D2cm3 was more correlated with the average doses of the three highest rectal points than rectal D2 cm3 (r =0.314,0.630,P =0.000,0.000).V100 showed a linear relationship with high-risk CTV (r =0.981,P =0.000).Bladder D2cm3 was higher than 430 cGy when the bladder volume was more than 80 cm3 ;small intestinal D2 cm3 did not change significantly when the bladder volume was less than 115 cm3,but decreased significantly once the volume exceeded the value.Conclusions Compared with the traditional 2D plan,the 3D plan for CT image-based cervical cancer brachytherapy significantly increases the target coverage and conformity index,but does not significantly increase the doses to organs at risk.Point dose evaluation is confirmed to be inaccurate.The doses to the bladder,rectum,and small intestine can be adjusted by controlling the bladder volume.

Objective To determine the optimum cuff pressure of the flexible laryngeal mask airway (LMA) for airway management in pediatric patients.Methods One hundred and twenty pediatric patients undergoing strabismus surgery with general anesthesia,of American Society of Anesthesiologists physical status Ⅰ or Ⅰ,aged 3-10 yr,were randomly divided into 3 groups (n=40 each) according to the cuff pressure of the flexible LMA:20 cmH2O pressure group (group A),40 cmH2O pressure group (group B) and 60 cmH2O pressure group (group C).The cuff was inflated to the predetermined pressure using the inflatable cuff manometer in each group.Oropharyngeal leak pressure was measured after LMA placement.Peak airway pressure and the difference between inhaled and exhaled tidal volume were recorded at 5 min of positive pressure ventilation.The LMA insertion condition,LMA removal time,and development of sore throat,hoarseness,dysphagia and abdominal distention within 24 h after operation were recorded.Results There were no significant differences in the success rate of LMA placement at first attempt,peak airway pressure,or incidence of sore throat among the three groups (P＞0.05),and no hoarseness or dysphagia was found in the three groups.Compared with group A,oropharyngeal leak pressure was significantly increased,and the difference between inhaled and exhaled tidal volume and incidence of abdominal distention were decreased in B and C groups (P＜0.05).There was no significant difference in the parameters mentioned above between group B and group C (P＞0.05).Conclusion The optimum cuff pressure of the flexible LMA is 40 cmH2O when used for airway management in the pediatric patients.

BACKGROUND: As a minimally invasive technology, percutaneous vertebroplasty is a safe and effective treatment for osteoporotic vertebral compression fractures.OBJECTIVE: To overview the research progress concerning the biomechanical properties, bone strength maintenance, bone absorption and degradation of bone filling materials used in percutaneous vertebroplasty.METHODS: The first author conducted a computer-based retrieval of CNKI, PubMed and Medline databases for relevant articles published from January 2005 to May 2016. The keywords were bone cement, bone filling materials, percutaneous vertebroplasty in English and Chinese, respectively.RESULTS AND CONCLUSION: Polymethyl methacrylate is not an ideal material for osteoporotic vertebral compression fractures. Calcium phosphate cement and calcium sulfate cement can replace the traditional polymethyl methacrylate; however, some problems still exist, such as poor effect of venography, incontrollable biological degradation rate, and lack of the evidence-based medicine about its long-term effect. Composite bone cement, as a good bone repair material, holds the advantages of various bone cements. As the composite bone cement has just been introduced in clinical practice, its long-term curative efficacy needs to be further studied.

Objective: To compare the effectiveness of short-segment and long-segment bone cement-augmented fixation combined with vertebroplasty in treatment of stage Ⅲ Kümmell disease. Methods: A clinical data of 44 patients with stage Ⅲ Kümmell disease met the selection criteria between January 2014 and December 2017 was retrospectively analyzed. Eighteen cases were treated with short-segment bone cement-augmented fixation combined with vertebroplasty (short-segment group) and 26 cases were treated with long-segment bone cement-augmented fixation combined with vertebroplasty (long-segment group). There was no significant difference in gender, age, disease duration, fracture segment, bone mineral density (T value), Frankle grading, and preoperative pain visual analogue scale (VAS) score, Oswestry disability index (ODI), anterior edge height of injured vertebrae, kyphosis Cobb angle, and thoracolumbar kyphosis (TLK) between the two groups ( P>0.05). The operation time, intraoperative blood loss, bone cement injection volume, bone cement leakage rate, VAS score, ODI, anterior edge height of injured vertebrae, kyphosis Cobb angle, and TLK were compared between the two groups. Results: The operation time and the intraoperative blood loss in the short- segment group were significant lower than those in the long-segment group ( P<0.05). There was no significant difference in bone cement injection volume and bone cement leakage rate between the two groups ( P>0.05). All patients were followed up 12-36 months, with an average of 24.4 months. The VAS score, ODI, anterior edge height of injured vertebrae, kyphosis Cobb angle, and TLK significantly improved at 1 week after operation and last follow-up in the two groups ( P<0.05), there was no significant difference between the two groups ( P>0.05). At last follow-up, the neurological function of the two groups recovered, and there was no significant difference in Frankle grading between the two groups ( P>0.05). There were 3 cases (16.67%) of non-surgical vertebral fractures in the short-segment group and 6 cases (23.08%) in the long-segment group, showing no significant difference between the two groups ( P>0.05). Bone rejection occurred in 1 case in the short-segment group, and neither internal fixation failure nor collapse of the injured vertebrae occurred during follow-up. Conclusion: Both short-segment and long-segment bone cement-augmented fixation combined with vertebroplasty can achieve good effectiveness in treatment of stage Ⅲ Kümmell disease, and can maintain the height of the injured vertebra and prevent the collapse of the injured vertebra. Compared with long-segment fixation, short-segment fixation has the advantages of shorter operation time and less intraoperative bleeding.

Objective To identify-and study a monoclonal antibody (McAb) against pancreatic cancer stem cell in vitro,as well as to provide candidate antibody-drug for cancer stem cell-targeted therapy of pancreatic cancer.Methods Cell culture in serum-free medium and PKH26 staining were used to determine the existence of cancer stem cell in PANC-1 cell line.Flow cytometry was used to detect the expression of CD24 and CD44 in PANC-1 cells and sphere cells,Immunofluorescence was used to detect the expression of CD24 and antigen recognized by 15D2.The effects of 15D2 on self-renewal,proliferation and chemosensitivity to gemcitabine of PANC-1 parent or sphere cells were identified by serum-free suspension culture and CCK-8 assay,Immunohistochemistry was applied to detect the level of antigen recognized by 15D2 in cancer and adjacent tissues.Results PANC-1 cells could survive,proliferate and form sphere cells in serum-free medium.The sphere-forming rate was (2.5±0.5) ％.The percentage of CD44+ CD24+ cells population in sphere cells increased by 11.4 folds compared to PANC-1 cells,in which single nearly 97 ％ CD24+ cells was CD44+ CD24+ cells.Therefore,CD24+ was selected for cancer stem cell marker in PANC-1 in this study.The two-color immunofluorescence assay showed that 15D2 could recognize cells which was also stained by CD24.In vitro functional experiments demonstrated that 15D2 significantly suppressed the sphere formation of PANC-1 cells,with the inhibitory rate being 30.4 ％.Meanwhile,the combination of 15D2 and gemcitabine can significantly attenuate the growth of PANC-1 sphere cells.The IC50 was 0.10 μmol/L in 15D2+gemeitabine group,and 0.39 μmol/L in mlgM+gemcitabine group,Immunohistochemical results showed that the antigen recognized by 15D2 was greatly expressed in about 76.9 ％ (11/13) human pancreatic cancer tissues and hardly detected in adjacent normal tissues (10.0 ％,1/10).Conclusion McAb 15D2 can inhibit self-renewal and drug-resistance of pancreatic cancer stem cell in PANC-1 cell line,and it might become a candidate drug for target pancreatic cancer stem cell treatment.

From August 2007 to January 2009 a total of 95 patients with complex renal calculi were treated with CT ( n = 32 ), X-ray ( n = 33 ) or ultrasound ( n = 30 ) guided percutaneous nephrostomy and ureteroscopic holmium laser lithotripsy respectively. The CT guided procedure had lower positioning time,positioning failure rate, complication rate and residual stone rate than those of X-ray and ultrasound localization, particularly had advantages in the stone clearance rate and complications rate ( all P ＜ 0. 05 ).CT guided localization can be chosen in the following conditions: higher kidney position, large staghorn calculi or renal pelvis stones without hydronephrosis, with congenital renal malformations or failure of ultrasound or X-ray localization.