BACKGROUND: Distal humerus fracture is often comminuted, and is difficult to receive reduction and fixation due to its special anatomical structure. Choosing which surgical approach is still a controversy.OBJECTIVE: To compare and analyze the curative efficacy of the perpendicular double-locking plating system for the internal fixation of type C distal humerus fractures through two kinds of postcubital approaches.METHODS: Thirty-two cases of type C distal humerus fractures were enrolled and divided into groups A (osteotomy of olecranon approach) and B (tricep anconeus flap approach). There was no significant difference in the baseline data between two groups. The operation time, intraoperative blood loss, hospital stay, healing time,postoperative follow-up and complications were recorded and analyzed. The patients were followed up at 2 weeks, 1, 3,6, 12, and 18 months. The healing time and complications were recorded according to radiographs and physical examinations. The Mayo Elbow Performance Score was used to determine the elbow function at 1 year postoperatively.RESULTS AND CONCLUSION: (1) The group A had a longer operation time and more intraoperative blood loss than those in the group B (P < 0.05), but showed a better elbow flexion and extension degrees, and higher Mayo Elbow Performance Score at 1 year postoperatively (P < 0.05). (2) There was no significant difference in the healing time between two groups (P > 0.05). (3) These results suggest that the articular surface of the distal humerus fracture is displayed well through two approaches, and the perpendicular double-locking plating system for the internal fixation of type C distal humerus fractures is rational. Noticeably, the tricep anconeus flap approach dose little damage to the muscle, while the osteotomy of olecranon approach obtains better elbow function and less complications.

Objective To evaluate the effect of heat treatment on ultraviolet B (UVB)-induced oxidative injury to human melanocytes.Methods Melanocytes were isolated from adult foreskins,and subjected to a primary culture.After 3-4 passages of subculture,the melanocytes were classified into 4 groups:control group incubated at 37 ℃,heat treatment group incubated at 42 ℃ for 1 hour,UVB group exposed to UVB irradiation at 100 mJ/cm2,combination group receiving heat treatment at 42 ℃ for 1 hour followed by UVB irradiation at 100 mJ/cm2.After three successive days of treatment,MTT assay was performed to evaluate cell viability,a biochemical method to determine the activity of superoxide dismutase (SOD) and concentration of malonaldehyde (MDA),and flow cytometry to detect intracellular reactive oxygen species (ROS) and apoptosis in melanocytes.Results The cell survival rate,apoptosis rate,SOD activity,MDA concentration and ROS level were (100 ± 6.14)％,(4.66 ± 0.58)％,(53.39 ± 8.23) U/gprot,(1.09 ± 0.32) mmol/gprot,and 1070.85 ± 42.07 in the control group respectively.UVB exposure induced a significant increase in apoptosis rate (24.14％ ± 2.90％,P ＜ 0.001),MDA concentration (1.65 ± 0.33 mmol/gprot,P ＜ 0.01) and ROS level (1416.45 ± 79.12,P＜ 0.01),but a significant decrease in cell survival rate (50.23％ ± 5.36％,P＜ 0.01)and SOD activity (31.98 ± 1 1.89 U/gprot,P ＜ 0.01) in the UVB group compared with the control group,while the heat pretreatment markedly downregulated the UVB-induced increase in apoptosis rate (14.9％ ± 1.49％,P ＜ 0.001),MDA concentration (1.10 ± 0.26 mmol/gprot) and ROS level (1033.30 ± 68.41,P＜ 0.01),as well as the decrease in cell survival rate (74.12％ ± 6.17％,P＜ 0.01) and SOD activity (51.63 ± 6.55 U/gprot,P＜ 0.01) in the combination group.Conclusion Heat treatment could protect melanocytes from UVB-induced oxidative injury.

BACKGROUND: The biomechanics of cervical spine is complicated. It is an important way to select the appropriate biomechanical model and research method so as to explore the diagnosis and evaluation mechanism of cervical spine injury and prognosis judgement.OBJECTIVE: To discuss the alternation of cervical biomechanics after the degeneration of cervical disc and the influence of degeneration on cervical stability.METHODS: (1) A three-dimensional finite element model of cervical spine was established from the CT scan images of cervical spine of a healthy male volunteer, Solid-Works2015, HyperMesh and ANSYS11.0. We created a cervical three-dimensional finite element model. To simulate the degenerative disc by modified the mechanical characters and height of the disc model, we observed the biomechanics of the impact on the cervical spine (the range and the stress on intervertabral disc).RESULTS AND CONCLUSION: (1) The entire model with a total of 97705 nodes and 372896 elements. Ligament and joint capsule were also constructed. Face to face contact element was used in the facet joint, with complete structure and high accuracy of measurement of spatial structure. (2) The range of motion of cervical spine increased during degeneration compared with normal cervical segments (P < 0.05). (3) Intervertebral disc degeneration caused angle increase at disc and motion segment. Osteophyte formed on vertebral edge. Intervertebral disc degeneration caused cervical instability. Simultaneously, instability increased the disc degeneration.

BACKGROUND: At present, bone remodeling biological model study usually applys finite element method combing with computer technique to simulate and predict bone quantity or bone structure. In this study the author integrate inversion method with animal experiment to establish a quantification bone remodeling biological model of in vivo bone tissue in real stress environment.OBJECTIVE: To set up a quantification biological model of bone growth and remodeling adaptation, which integrates animal experiments, parameter inversion identification of mathematical functions, and technique of computer simulation. DESIGN, TIME AND SETTING: The experiment was accomplished in Animal Experiment Center of Dalian Medical University in October 2002.MATERIALS: 60 female Sprague Dawley mice of 6-week old were used in this study. Challenger double-energy X ray bone density device was provided from DMS Company, France. Sensation l6 CT machine was provided from Germany Siemens Company.METHODS: 60 mice were randomly divided into two groups: i 5 animals were in normal control groups. 45 in experiment groups. By designing a new animal experiment, we investigate the effects of stress environments on bone growth and remodeling of rapid growing rats and gather the bone mineral density (BMD) of proximal femur in the same interval for the unknown parameters (B and K) inversion of bone growth and remodeling equation to create the femur three-dimension geometrical model based on CT images. MAIN OUTCOMING MEASURES: Body weight of animal, bone density and CT imagine of proximal femur. RESULTS: Body mass in the experiment group and control group was increased with the rat growing; BMD in the control group and overloading group was also increased with the rat growing; but BMD in the unloading group was decreased in the fifth week. Inversion and experimental data showed that parameter B was rapidly decreased as compared to time, and it was closed to zero in the 10th week. Parameter K was rapidly increased as compared to time. and it was gradually increased from the 5th to the 10th weeks, moreover, it was closed to the horizontal line after 10 weeks. This predicted that rapid growth was over, and bone reconstitution and absorption came into another balance cycle. CONCLUSION: The thought and method used in the model creating in.this paper provide clue and reference to establish human model of bone growth and remodeling.

Objective To investigate the effects of hepatic pedicle exclusion and low central venous pressure (LCVP) on blood loss in right lobe tumor resection and evaluate its influence on hepatic and renal function. Methods Forty-eight patients with right lobe tumor admitted from December 2006 to June 2008 were randomly allocated to the LCVP group (23 cases) and routine hepatectomy, (control group 25 cases). During the parenchymal transection phase of surgery, CVP < 5 mm Hg ( 1 mm Hg = 0.133 kPa) and SBP ≥90 mm Hg were maintained in the LCVP group by drugs. However, no special management of CVP and SBP was done in control group. The parenchymal transection blood loss, postoperative hospital stay, postoperative hepatic and renal function changes between two groups were compared, and the incidence of comphcation was also observed. Results There were no significant difference in type of hepatectomy, time of vascular clamping, period of operation, postoperative complication rate, postoperative hepatic and renal functions between two groups. Parenchymal transection blood loss in the LCVP group was significantly lower than that in the control group (326.67 ± 109.13 ) ml vs (538.33 ± 177.07 ) ml, (P < 0.01 ). Postoperative hospital stay in the LCVP group was significantly shorter than that in the control group (8.52 ± 1.78) d vs (9.40±1.68) d, (P < 0.05). Conclusions Hepatic pedicle exclusion and LCVP during hepatectomy is safe. It can reduced blood loss during parenchymal transection and decrease postoperative hospital stay. It is no detrimental effect to hepatic or renal function.

Objective To explore the value of preoperative diagnosis for breast cancer patients in different locating ways. Methods The tissues were gotten by core needle biopsy from 146 breast cancer patients through different locating ways,and were taken for histopathological examinations and were compared with postoperative pathologic results. Results Seventy-four cases were biopsied with ultrasound-guide (ultrasound-guide group), and 72 cases with free-hand (free-hand group), without serious complications.Compared with postoperative pathologic results,the false negative rate in ultrasound-guide group was 5.41%(4/74);the false negative rate in free-hand group was 18.06% (13/72). The accuracy of the ultrasound-guided biopsy was higher than that in free-hand (U = 13.63,P ＜ 0.01 ). Conclusions Preoperative ultrasoundguided biopsy and postoperative pathologic examination has no significant difference, with high consistency.The study provides a good basis for selection for clinical work,so as to the more effective guide for the comprehensive treatment of breast cancer patients.

BACKGROUND:Pathological mechanism of femoral head necrosis is not fuly known, and high-dose corticosteroids are prone to induce femoral head necrosis.
OBJECTIVE:To investigate the clinical effect of bone marrow mesenchymal stem cels combined with theaflavin on steroid-induced avascular necrosis of femoral head in rats.
METHODS: Rat bone marrow mesenchymal stem cels were isolated and culturedin vitro and compounded onto gelatin sponge, and then, divided into four groups: model group, decompression group, cel transplantation group and combined group. Models of steroid-induced avascular necrosis of femoral head were established using liquid nitrogen method. In the combined group, gelatin sponge carrying bone marrow mesenchymal stem cels was transplanted and 250 mg theaflavin was given daily after modeling.
RESULTS AND CONCLUSION:At 4 weeks after modeling, the femoral head samples in the four groups were round with exfoliation of articular cartilage that was pale in color. Then, the exfoliation of articular cartilage was aggravated in the model group, and some specimens appeared to colapse; the femoral head specimens in the combined group were round and pale. Until the 8th week after modeling, bone necrosis was increased in the model group; osteoblasts were found in the decompression group with fibrous calus formation; a few of empty bone lacunae appeared with irregular medulary cavity in the cel transplantation group; a large amount of new bone tissues formed in the combined group, and intramedulary adiocytes were in regular array. At 4 and 8 weeks after modeling, the number of empty bone lacunae was significantly lower in the combined group than the other groups (P < 0.05). These findings indicate that bone marrow mesenchymal stem cels combined with theaflavin is an ideal therapy for steroid-induced avascular necrosis of femoral head.

Objective To evaluate effects of ascorbic acid on proliferative activity of cultured melanocytes in vitro, as well as on H2O2?induced oxidative injury in melanocytes. Methods The optimal concentration of ascorbic acid solution and median lethal dose of H2O2 solution were determined by CCK?8 assay for the following experiment. Cultured melanocytes were classified into the control group, ascorbic acid group, H2O2 group and combination group. During the first 24 hours, the control group and H2O2 group were treated with M254 medium, while the ascorbic acid group and combination group with ascorbic acid solution. During an additional 24?hour period, the control group and ascorbic acid group were treated with M254 medium, while the H2O2 group and combination group with H2O2 solution at the median lethal dose. After 48?hour treatment, CCK?8 assay and flow cytometry were performed to determine the survival rate and apoptosis rate of melanocytes, respectively, in the 4 groups. Biochemical methods were used to evaluate the superoxide dismutase(SOD)activity and determine the malondialdehyde(MDA)concentration, and fluores?cent staining was conducted to detect the level of reactive oxygen species(ROS)in the control group, H2O2 group and combination group. Results The optimal concentration of ascorbic acid solution was 1 000μmol/L, and the median lethal dose of H2O2 solution was 300 μmol/L. The cell survival rate, apoptosis rate, SOD activity, MDA concentration and ROS fluorescence intensity in the control group were 100% ± 4.99%, 6.90% ± 0.87%, 54.71 ± 4.75 U/mgprot, 263.39 ± 20.17 nmol/mgprot and 342.16 ± 27.36 respectively. Compared with the control group, H2O2 solution could significantly increase the cell apoptosis rate(16.47%± 1.07%), SOD activity(103.62 ± 10.44 U/mgprot), MDA concentration(493.70 ± 31.36 nmol/mgprot)and intracellular ROS fluorescence intensity (782.48 ± 36.25), but decrease the survival rate of melanocytes (39.07% ± 2.94%), while ascorbic acid solution markedly down?regulated the H2O2?induced apoptosis (11.83%± 0.95%), SOD activity(76.73 ± 5.20 U/mgprot), MDA concentration(371.82 ± 23.05 nmol/mgprot) and ROS level (475.64 ± 52.18), but increased the cell survival rate (74.31% ± 5.53%). Conclusion Ascorbic acid solution at the concentration of 1 000 μmol/L can not only promote proliferative activity of melanocytes, but also protect melanocytes from H2O2?induced oxidative injury.

Objective This paper explored the effect of the early clinical exposure in im-proving medical students' cognitive aspects of the doctor-patient relationship. Methods (1)From 280 undergraduate students of Grade 2010 who participated in early clinical exposure of Xi'an Jiaotong University College of Medicine and 280 undergraduate students of Grade 2011 who did not participate in the early clinical exposure, we selected 140 students respectively to conduct a simple random sam-pling survey. The results were analyzed by SPSS after using Microsoft Excellsoftware for entry. Statis-tical methods selected χ2-test/Fisher exact test(P<0.05). (2)We had an interview to students,teachers leading the project, instructor,experts engaging in the study of the doctor-patient relationship by using focus group discussion and in-depth interview, and then using thematic analysis to analyze the data. (3)The main aspects of questionnaires and interviews were: details, activity participation/interest, general cognitive on the doctor-patient relationship, passion for profession, choice of career, the effect in improving medical students' cognitive aspects of the doctor-patient relationship and the suggestions and comments. Results The effective questionnaires collected from Grade 2010 were 134, and124 from Grade 2011.The participation rate of the undergraduates of Grade 2010(participating group) was 94.0%(126/134), while the interest rate of undergraduates of Grade 2011 (control group) was only 76.6%(95/124). Participating group had a better cognitive understanding of doctor-patient relationship than control group(P=0.0192). The activities had significant effects on choice of career(P=0.0002), and no effect on passion for profession(P=0.7372). There was statistically significant difference on their views of employment(P=0.0002). The key words for the interview were: not enough preparation before activity, not reasonable timing, teachers leading the project, stimulation of professional pride. Conclusions Early clinical exposure activities can be effective in improving medical students' awareness of the current doctor-patient relationship. Still we have some shortages in the activity, some more exploration and amelioration should be made in late stage.

OBJECTIVE To study the influence of focused ultrasound on the morphology of nasal mucosa in sheep. METHODS A model CZB ultrasound therapeutic system for rhinitis, developed and produced by Chongqing Haifu(HIFU)Technology Co.,Ltd.,Chongqing China,was used in this study. Linear scans were performed on bovine liver in vitro under different scan parameters, and the biologic focal field(BFF)was detected to evaluate if it met the requirements of designed. The nasal mucosa of inferior turbinate of sheep was exposed with the same scan parameters under the observation of nasal endoscope, and morphological changes of the nasal mucosa were observed by gross examination, light and electron microscopes. RESULTS This study revealed that the designed biological focal field in bovine liver in vitro could be obtained under the scan parameters mentioned above. Linear scan with the same condition,there was no obvious change in appearance and color of the treated nasal mucosa in the inferior turbinate of the sheep. However,3 days after treatment,there was an increased secretion in the nasal cavity,which recovered 7 days post-treatment. Light microscopic examination 3 days after exposure showed that the epithelia of the nasal mucosa was intact and there was diffused distribution of spot coagulated necroses in the subepithelia layer of treated nasal mucosa. Degeneration of vascular endothelial cells and thrombosis of blood vessels were found in the coagulated necrosis region. Besides,degeneration or necrosis of nerve cells was induced,and glandular cells werepartially or completely damaged. The structure of epithelial goblet cells and ciliated cells in the treated nasal mucosa appeared to be normal under the observation of electronic microscope. At the seventh day after treatment,signs of tissue regeneration such as hyperplasia of collagen fiber were found in the coagulated region,and the necrosis tissue began to dissolve and was absorbed at the 14th day post-treatment. CONCLUSION Under the above scan parameters,the energy of focused ultrasound could be deposited specifically at the subepithelia layer,and to ablate the targeted nasal mucous tissues which are rich in blood vessels,nerves and glands. There were no damage to the non-target area such as epithelial layer,which could maintain the normal structure and biological function of mucociliary of nasal mucosa.