BACKGROUND:Computer-assisted navigation technique has been widely applied in spinal surgery, but there is stil lack of systematic reviews on this technique in lumbar pedicle screw fixation.
OBJECTIVE:To evaluate the application of computer-assisted navigation technique in lumbar pedicle screw fixation.
METHODS:Databases such as PubMed, Embase and China journal ful-text database CNKI were searched for articles about computer-assisted navigation in lumbar pedicle screw fixation, and related studies and literatures were hand-searched as wel , and then insertion accuracy, intraoperative blood loss, operative time consumption and rate of insertion-related complications between computer-assisted navigation technique group and conservative technique group were compared.
RESULTS AND CONCLUSION:Final y 7 studies which met the inclusion criteria were included with 784 patients and 4 101 lumbar pedicle screws in total. Meta-analysis indicated that malposition rate [relative risk (RR)=0.44, 95%confidence interval (CI):(0.27, 0.69), P=0.000 4] and intraoperative blood loss [weighted mean difference (WMD)=-172.40, 95%CI:(-246.26,-98.53), P<0.000 01] had statistical y significant differences between computer-assisted navigation technique group and conservative insertion group. However, operative time consumption [WMD=-31.45, 95%CI:(-85.56, 22.66), P=0.25] and incidence of complications [RR=0.41, 95%CI:(0.12, 1.41), P=0.16] did not show significant differences between groups. Application of computer-assisted navigation technique in lumbar pedicle screw fixation would improve insertion accuracy. However, further study is stil needed to make clear whether this technique can improve final outcome in post-operative patients.

This paper analyzed the present status of the statistical teaching in medical sciences university and indicated that statistical teaching plays an important role in improving the students' Scientific Research Practice Ability.

0.05) and group TP2 ( P

Objective To establish osteosarcoma vaccine by the LM9 osteosarcoma derived from C3h mice hybridized with activated B lymphocytes and study its biological behavior and the antitumor efficacy. Methods The LM9 osteosarcoma derived from C3h mice was fused with LPS activated B lymphocytes by using 50%PEG. The fused cells was selected by HAT medium and cultured in vitro, and the biocharacter and efficacy of the fusion vaccine were investigated. Results In contrast to LM8, the fused cells grew significantly slowly in vitro. All the mice under the protection of fused vaccine survived without tumor (8/8), while all the mice in the control group succumbed to the tumor with no survival (8/8), 75%of the mice inoculated subcutaneously with cell fusion vaccine survived without tumor burden after implantation of LM8 cells subcutaneously. The mice in the control group developed tumors and died within 45 days without any exception. Conclusion It is possible that the LM9 osteosarcoma biology characteristics change after fused with LPS activated B lymphocytes. Cell fusion osteosarcoma vaccine could produce prophylactic and therapeutic effects in mice.

To design the lecture introduction of the sketch of RPD in prosthodontics by the following ways: such as textbooks, teaching aim, the key and difficulty points in teaching, the arrangement of the lecture, the preparation of teaching aids, learning, teaching methods process, preparation, situation creation, leading-in of new lessons, discussion, impartment and points, case demonstration, display of blackboard-writing, summary and conclusion as well.

AIM: To investigate the effects of dehydroepiandrosterone (DHEA) on experimental osteoarthritis in rats. METHODS: Forty rats were randomly divided into four groups. Group A is normal control group. Osteoarthritic models of rats were established by intraarticular injections of papain into the right knee joints of groups B, C and D. Then the right knee joints of rats in groups C and D, respectively, received 150 ?l intraarticular injections of DHEA at a concentration of 50 ?mol?L~(-1) and 100 ?mol?L~(-1), and the right knee joints of rats in groups A and B both received 150 ?l physiological saline, twice weekly for five weeks. Six weeks later, all rats were sacrificed, and the articular cartilage was assessed by gross morphologic, histologic, biochemical and immunohistochemical methods. RESULTS: The cartilage damage in groups C and D was much less than that in group B through observation under a surgical microscope. The Mankin's score, nitric oxide (NO) in the douche of articular cavity, malondialdehyde (MDA) in synovium, the expression of matrix metalloproteinase-1 and 9 in articular cartilage in groups C and D decreased in comparison with group B, and the foregoing indexes in group D decreased significantly compared with group C. However, the activities of superoxide dismutase (SOD) in the douche of articular cavity and blood serum in groups C and D increased in comparison with group B, and the foregoing indexes in group D increased significantly compared with group C. CONCLUSIONS:DHEA shows a cartilage-protecting effect which is in a dosage-dependent manner. The mechanism probably is to inhibit the expression of matrix metalloproteinases and to decrease the release of (NO and enhance the antioxidation.

Anesthesia safety plays an important role in the medical safety of the perioperative.At present the medical institutions in many countries apply crew resource management model for training and assessment in anesthesiology,surgery and emergency.It emphasizes the training of nontechnical skills,called crisis resource management(CRM).This article analyzes the causes of human error incidents and preventive measures and introduces CRM principles in medical principles and anesthesia correlation and applications.CRM helps to foresee the crisis of environment and deal with the crisis source to ensure the safety of patients.

Objective:To examine the expression and function of thrombonspondin-1 (TSP-1) in oxygen-induced retinopathy in new-born mice, and to investigate its role in retinal neovascularization. Methods:A total of 40 C57BL/6J newborn mice were divided equally into a model group (n=20)andanormalcontrolgroup(n=20).Miceinthemodelgroupwereexposedto75%oxygentoestablish the oxygen-induced retinopathy (OIR) model. On the 7th, 9th, and 11th day after the birth of mice, 5 mice were randomly selected each time from the 2 groups to examine the expression of TSP-1 mRNA with reverse transcription polymerase chain reaction (RT-PCR). After that, 5 mice were selected on the 11th day to observe the retinal neovascularization by fluorescein angiography retinal flatmount. Results:On the 11th day, fluorescein angiography retinal flatmount showed that the retinal blood vessels presented mean network distribution in the normal control group, while in the model group, a lot of dilatated areas in the retinal main vessels surrounded the optic disc. Meanwhile lots of new blood vessels were found surrounding the optic disc with irregular distribution but well distributed peripherial retinal small vessels, which was typical of early stage OIR. There was no signiifcant difference in the retinal TSP-1 mRNA level between the model group and the normal control group in the postnatal 7-day mice (P>0.05). Compared with the normal control group, the expression of TSP-1 mRNA in the model group was signiifcantly lower in postnatal 9-day and 11-day mice (P<0.05, P<0.01) , and the expression of TSP-1 mRNA in postnatal 9-day mice was lower than that in the postnatal 11-day mice(P<0.05).
Conclusion:In the early stage of OIR model (retinal vascular growth and development stage), the expression of TSP-1 mRNA in the retinal tissue is gradually decreased, implying that TSP-1 (as a negative regulatory factor) may be involved in the formation of retinal neovascularization in the early stage.

BACKGROUND:It is confirmed that the characteristics of soft and hard tissue development vary largely in different vertical facial types, which reflect the development trend of the patients and the control ing degree on anchorage.
OBJECTIVE:To evaluate the influence of different vertical facial types on the aesthetic evaluation of facial profiles in young females, and analyze the perception of facial attractiveness from different people.
METHODS:Three beautiful females, with high, average and low mandibular angle, respectively were selected according to the measurement data of projection and the orthodontist’s aesthetic appreciation. They were yel ow race, bilateral facial appearance was basical y symmetrical, and no other maxil ofacial disease was found. They also received no orthodontic or orthognathic treatment. The profile digital photographs and cephalograms of three females were col ected. The positions of soft tissue lip and soft tissue chin were altered incremental y with Dolphin Imaging and Management software. Twenty-five new pictures were generated by the smal scale (2 mm per unit) modification in the sagittal direction. By using“acceptable facial appearance”as a filter, 15 orthodontists selected 11 from 25 pictures. Fifty parents of orthodontic patients, 50 orthodontic patients, and 50 amateurs were taken as the evaluators for subjective aesthetic ratings and for the assessment of the influence of vertical facial types on the facial profile attractiveness.
RESULTS AND CONCLUSION:With low and average angle, straight profile, slightly protrude chin was perceived to be beautiful. With high angle, straight profile, slightly protrude profile was perceived to be beautiful, and evaluation results are consistent between men and women. Evaluators are in agreement when it comes to evaluating the perception of facial attractiveness of three different vertical facial types profile in young females. They also have certain difference in aesthetic tendencies, but when it comes to straight profile they share the same preference. Although different vertical facial types profile has an impact on the profile of lip and chin, but it can’t represent the aesthetic preference of al evaluators.

A method was developed for simultaneous determination of pyrrolizidine alkaloids and isoquinoline alkaloids in honey by dispersive solid phase extraction and high performance liquid chromatography-tandem mass spectrometry ( QuEChERS-HPLC-MS/MS) . The honey samples were extracted with acetonitrile solution and cleaned up with PSA absorbent. Agilent Poroshell 120 SB-C18 chromatographic column was used to separate alkaloids with high sensitivity and satisfactory resolution. The identification and quantification were achieved by using electrospray ionization in positive ion mode ( ESI+) with multiple reaction monitoring (MRM). Matrix-matched calibration curves with good correlation coefficients (R2>0. 99) were obtained in the concentration range of 0. 1-100 μg/L. The recoveries of the spiked samples at 1-100 μg/kg were in the range of 70% to 110% with the RSD of intra-day and inter-day lower than 15% and 20%, respectively. The limits of detection ( LOD) and limits of quantification ( LOQ) for all alkaloids were 0. 3 and 1. 0 μg/kg, respectively. This method was successfully applied to the simultaneous determination of pyrrolizidine alkaloids and isoquinoline alkaloids for quantification and confirmation in honey samples.