The paper analyzed the economies of scale of medical service and its characteristics according to the concepts and original of such a theory. It holds that hospital operations demands an appropriate size; for medical services in need of procuring large equipments, specialized service units of an appropriate size are more cost effective than service provision in individual hospitals; web release of medical service information and price information can help expand the market size; hospital alliances can integrate medical services horizontally and vertically. The above measures can attain the economies of scale for medical service.

Objective:To analyze the effect of endoscopic submucosal tunnel dissection on patients with large esophageal superficial neoplasms.Methods: Chosen patients with large esophageal superficial neoplasms in our hospital as research object, randomly divided into control group treated by endoscopic mucosal dissection (ESD) and observation group treated by endoscopic submucosal tunnel dissection(ESTD), compared surgery related indicators, complications and treatment outcomes.Results: 1)Observation group patients’ tumor stripping rate (23.17±4.73)/min was significantly higher than control group patients’ (12.65±2.19)/min; Intraoperative blood loss(9.14±0.67)ml, total length of hospital stay (7.34±1.89) d, were significantly less than control group patients with intraoperative blood loss(21.38±3.14)ml, total length of hospital stay (13.21±3.05)d, t value was 4.965, 5.395, 4.932, respectively(t=4.965,t=5.395,t=4.932;P<0.05); 2)Observation group patients esophageal bleeding ESTD rate(5.26%), esophageal stricture rate(31.58%), mediastinal emphysema rate(5.26%), esophageal perforation rate of 0, were significantly less than control group patients with esophageal bleeding rate(31.58%), esophageal stricture rate(5.26%), mediastinal emphysema rate(21.05%), esophageal perforation rate (26.32%), t value were 4.378, 4.378, 4.471, 5.758, (t=4.378,t=4.378,t=4.471,t=5.758;P<0.05); 3)Observation group patients with no recurrence during the follow-up period, control group patients with local recurrence rate of 21.05%, t value 8.623,P<0.05(t=8.623, P<0.05).Conclusion: Endoscopic tunnel mucosal stripping technique can effectively improve the complete tumor removal rate, during the process of optimization operation at the same time reduce the occurrence of complications, to the improvement of the prognosis of patients with positive clinical significance.

Objective To observe the influence of the stress and displacement when the normal sacroiliac joint is exerted load simulating oblique-pulling manipulation, and to analyze the stress and displacement distribution when a three-dimensional finite element model of normal pelvis is exerted by oblique-pulling manipulation. Methods Lateral position was simulated on the three-dimensional finite element model of normal pelvis and it exerted loads horizontally forth and back, then the stress and displacement distribution were calculated. Results When the normal sacroiliac joint was exerted load simulating oblique-pulling manipulation, stress of the pelvis was mainly concentrated on the anterior inferior part of the left iliac fossa from the front view, with a maximum stress of 0.540E+07. The maximum value of internal and external strain of normal sacroiliac joint was 8.682 × 10-4m;the maximum value of anteropostreior strain was 3.337 × 10-4m;and the maximum value of up and down strain of normal sacroiliac joint was 3.284 × 10-4m. Conclusions The focus of the sacroiliac joint stress is mainly on the anterior and posterior superior borders when the normal pelvis exerted oblique-pulling manipulation. The internal and external strain of normal sacroiliac joint is maximal, the anteropostreior strain ranges the second, and the up and down strain is minimal.

Objective To evaluate the effect of sevoflurane postconditioning on the expression of CCAAT/enhancer-binding protein homologous protein (CHOP) in a rat model of hemorrhagic shock and resuscitation.Methods Thirty-six healthy adult male Sprague-Dawley rats,weighing 300-350 g,were divided into 3 groups (n=12 each) using a random number table:sham operation group (group S),hemorrhagic shock and resuscitation group (group HSR) and sevoflurane postconditioning group (group SP).Hemorrhagic shock was induced by withdrawing 40% of the total blood volume from the right carotid artery over an interval of 30 min,and 1 h later the removed blood was reinfused via the left jugular vein for resuscitation.Group SP inhaled 2.4% sevoflurane for 30 min starting from the onset of reinfusion.Mean arterial pressure was monitored and recorded at a 10 min interval.Before withdrawing blood (T0),immediately after the end of withdrawing blood(T1), at 1 h after the end of withdrawing blood(T2) and immediately after the end of reinfusion (T3),blood samples were collected from the common carotid artery for blood gas analysis.At 4 days after reinfusion,6 rats of each group were selected to detect spatial learning and memory ability by using Morris water maze test.The animals were then sacrificed,brains were removed for determination of neuronal apoptosis in hippocampal CA1 area using TUNEL.The rest 6 rats in each group were sacrificed at 72 h after reinfusion,and the hippocampus was isolated to detect the expression of CHOP by Western blot.Results Compared with group S,mean arterial pressure was significantly decreased,and lactic acid concentrations were increased at T1,2 in HSR and SP groups,and the escape latency was significantly prolonged,the percentage of time staying at the target quadrant was decreased,the number of apoptotic neurons in hippocampal CA1 area was increased,and the expression of CHOP was up-regulated in group HSR (P<0.05).Compared with group HSR,the escape latency was significantly shortened,the percentage of time staying at the target quadrant was increased,the number of apoptotic neurons in hippocampal CA1 area was decreased,and the expression of CHOP was down-regulated in group SP (P<0.05).Conclusion The mechanism by which sevoflurane postconditioning improves cognitive function is related to down-regulation of CHOP expression and inhibition of apoptosis in hippocampal neurons in a rat model of hemorrhagic shock and resuscitation.

ObjectiveTo analyze and summarize the feasibility and characteristics of the posterior spinal canal reduction and fixation in treating mid-upper thoracic spine facture.MethodsA retrospective study was made on 17 patients with mid-upper thoracic spine facture to record the complication, compare the functions of the patients with complete and incomplete spinal cord injuries before and after surgery and examine the iatrogenic injury in patients without spinal cord injuries.ResultsNo complication happened after surgery.Incomplete injury was found in six patients, whose ASIA scales were found to be increased for 1-3 levels during the follow-up.While the complete injury was found in eight patients,whose ASIA scale remained unchanged during the follow-up.The sensory scores of both the incomplete injury group and complete injury group were processed with variance analysis and the results showed a significant difference between pre-operation and post-operation (F = 476.47, P = 0.000).The mean value between complete injury group and incomplete group was with high statistical difference (F = 31.46, P =0.000).The variance analysis of the motor scores showed a significant difference between before and after operation (F=46.75, P =0.000) and the mean value between complete and incomplete injury groups was with statistical difference (F = 158.59, P = 0.000).There were three patients with normal spinal cord function, with no decrease of ASIA scale or no change of the sensory and motor scores.ConclusionsFor patients with mid-upper thoracic spine fracture, posterior spinal surgery is conducive to the recovery of spinal function, for it can safely and effectively avoid worsening the thoracic and other combined injuries and release spinal pressure including the pressure in front part of the spinal cannal.

Objective To investigate the association of expressions of cyclooxygenase-2(COX-2),matrix metanoproteinases-9(MMp-9)and Ki67 with occurrence,infiltration and metastasis of gastric cancer.Methods Fifty-eight surgically obtained and pathologically performed cancerous tissues were collected between Jan.2003 and Dec.2005.Among them,37 were males and 21 were females with mean age of 58.2 years(ranged from 31 to 76 years).Fifty-eight paracancerous tissues(5-6 cm apart form the cancer)were taken as controls.The expressions of COX-2,MMP-9 and Ki67 in cancerous or paracancerous tissues were examined by immunohistochemistry.Results The expressions of COX-2 and MMP-9 in cancerous tissues(82.76%and 68.9%,respectively)were higher than those in controls(37.93%and 24.14%,respectively,P＜0.01).The expressions of COX-2 and MMP-9 were not associated with sex,age,location and size of gastric cancer(P＞0.05),but were correlated with the depth of lymph node infiltration.metastasis and TNM stage(P＜0.05).The expression of MMP-9 was also associated with the degree of differentiation of gastric cancer(P＜0.05).There was a correlation between COX-2 and MMp-9 expressions in gastric cancer tissues(P＜0.05,C=0.359).The expression of Ki67 in tissues with positive expressions of COX-2 and MMp-9 was higher than that in negative ones(P＜0.O 1).Conclusion The COX-2,MMP-9 and Ki67 play important roles in metastasis and infiltration,which promote occurrence and development of gastric cancer.

Objective To investigate the effects of parecoxib and morphine on remifentanil-induced postoperative hyperalgesia in patients undergoing orthopedic operation. Methods Sixty ASA Ⅰ or Ⅱ patients,aged 20-62 yr, weighing 45-100 kg, undergoing orthopedic surgery, were randomly divided into 3 groups ( n = 20 each). Anesthesia was induced with midazolam, propofol, remifentanil and rocuronium. The patients were mechanically ventilated after tracheal intubation. Group Ⅰ received iv injection of morphine 0.15 mg/kg, group Ⅱ received iv injection of parecoxib 20 mg and morphine 0.075 mg/kg and group Ⅲ received iv injection of parecoxib 40 mg and morphine 0.075 mg/kg. Anesthesia was maintained with infusion of propofol and remifentanil and intermittent iv boluses of vecuronium. The emergence time, consciousness recovery time, extubation time,incidence of agitation and shivering, and VRS score at 5 min after recovery of consciousness were recorded. Pain at rest and at movement was evaluated using VAS score at 1,2, 4, 8, 12 and 24 h (T1-6) after surgery and MAP andHR were recorded simultaneously. The incidence of nausea and vomiting during 24 h after surgery was also recorded. Blood samples were taken before induction of anesthesia, at the end of operation and 24 h after operation for determination of plasma concentrations of PGE2 and TNF-α. Results There was no significant difference in emergence time, consciousness recovery time, extubation time, VRS scores, MAP, HR, incidence of agitation,shivering, nausea and vomiting among the 3 groups. Compared with group Ⅰ , VAS scores at rest at T1-2 and at movement at T1-6 were significantly increased in group Ⅱ , while VAS scores at rest and at movement decreased at T1-5 in group Ⅲ (P＜0.05). VAS scores at rest at T1-6 and at movement at T1-5 were significantly lower in group Ⅲ than in group Ⅱ (P＜ 0.05). There was no significant difference in the plasma concentrations of PGE2 and TNF-α at different time points between group Ⅰ and Ⅱ (P＞0.05). The plasma concentrations of PGE2 and TNF-α were significantly lower at the end of surgery in group Ⅲ than in group Ⅰ and Ⅱ (P＜0.05). Conclusion Preoperative iv parecoxib 40 mg and morphine 0.075 mg/kg can reduce remifentanil-induced postoperative hyperalgesia in patients undergoing orthopedic operation, and the efficacy is better than that of morphine alone.

Objective To observe the effects of pressure control ventilation with volume guar-antee (PCV-VG)on the pulmonary function during percutaneous nephrolithotomy procedures in pa-tients with general anesthesia.Methods Forty patients scheduled for percutaneous nephrolithotomy were selected and randomly allocated into PCV-VG group (n =20)and volume controlled ventilation (VCV)group (n =20).For two modes of ventilation,the goal tidal volume was 6-8 ml/kg,and the respiratory rate was contralled to 12-20 bpm.PA-a O 2 ,OI,RI,Ppk,Pmean,Cst,Hct,Lac were re-corded at intubation (T0 ),1 5 min (T1 ),30 min (T2 ),60 min (T3 ),and 120 min (L4 )after intuba-tion.Results PCV-VG resulted in significantly lower PA-a O 2 ,RI,Ppk,Pmean compared with VC ventilation (P < 0.05 or P < 0.01 ),and significantly higher OI,Cst versus VC ventilation (P <0.05 or P < 0.01).Conclusion In general anesthesia patients undergoing percutaneous nephrolithoto-my,PCV-VG is superior to VCV in terms of lower airway pressure and more stable hemodynamics, thus protects pulmonary function.

Objective To explore the attention bias characteristics and impacts of attention training on negative attention bias of undergraduates with sub-clinical depression.Methods The undergraduates whose BDI scores being at the top of 5％ were recruited as participations and assigned to early attention training group and late attention training group using random number table.The dot probe paradigm was used to compare the difference of depressive symptoms and ingredients of attention bias made by different processing phases of attention training.Results (1)The BDI score after the training(87.91± 12.47) was significantly lower than that the former test (97.23±17.72) (F~,32)=4.78,P＜0.05),and the attention bias score in late attention training group (-5.97±2.92) was lower than that in the early attention training group(2.77±2.75) (P＜0.05).The interaction of the stimulus materials presenting time and the measuring time was significant(F(2,64) =4.76,P＜0.05).Simple effect analysis showed that when the time of stimulus material presenting was 1 000 ms,the score of negative attention bias after the test (-4.89 ± 23.66) was significantly lower than pre-test (7.73±26.14) (F(1,33) =5.11,P＜ 0.05).In the pre-test,the negative attention bias scores of the stimulus materials presenting time for 100 ms and 1 000 ms (8.62 ± 27.60,7.73 ± 26.14) were significantly higher than that for 500 ms (-12.80±29.09)(P＜0.05).(2)When the negative disengaged score as a dependent variable,the repetitive measure analysis of variance showed that the interaction effect of the stimulus materials' presenting time and training group type was significant (F(1,32) =4.41,P＜0.05).Simple effect analysis results indicated the negative disengaged score of the late attention training group at post-test (-5.84±7.79) was significantly lower than that at pre-test (24.16±7.35) (P＜0.05).Conclusion The attention training during the late stage of the attention process can efficiently intervene the negative attention bias of undergraduates with sub-clinical depression.

Objective To evaluate the effect of conventional or goal-directed fluid management on hemodynamics in patients undergoing orthopaedic arthroscopic shoulder surgery in beach chair po-sition.Methods Thirty healthy adult patients,male 1 7 cases,female 13 cases,aged 18-65 years, weight 49-68 kg,ASA Ⅰor Ⅱ,undergoing elective arthroscopic shoulder surgery,were enrolled.Pa-tients were randomly assigned to the group R(Routine group,n = 1 5 )and the group S(SVV/CI/MAP-directed,n =1 5).All patients received 10 ml/kg of hydroxyethyl starch rapidly in group R;while in group S,if SVV > 13%,patients would receive 3 ml/kg of hydroxyethyl starch in 5 min, then the changes of each index were observed;if SVV <13% and CI< 2.5 L·min-1 ·m-2 ,given dopamine 0.5~1 μg·kg-1 ·min-1 ,until CI>2.5 L·min-1 ·m-2 .At 5 min after anesthesia induc-tion,patients were placed in a 60° upright position.The hemodynamic changes were monitored by FloTrac/Vigileo system.Heart rate (HR),mean artery pressure(MAP),cardiac index(CI),stroke volume variation(SVV),stroke volume index (SVI),were recorded on pre-induction (T1 ),post-induc-tion (T2 ),immediately after in beach chair position (T3 ),5 min after in beach chair position(T4 ),30 min after in beach chair position(T5 ),and at the end of surgery(T6 ).The duration of surgery,crys-talloid requirements,colloid requirements,urinary output,the dose of vasoactive drugs and the inci-dence of hypotension were recorded.Results Compared with T1 ,MAP,CI and SVI at T3-T5 point (after in BCP to the end of the surgery)were higher in both group(P <0.05 ).Compared with T2 , SVV in group R at T3-T5 were significantly increased (P <0.05),while SVV in group S only at T3 was slightly increased (P <0.05).Compared with group R,MAP,CI and SVI at T3-T5 were signif-icantly higher respectively,while SVV were higher at T3-T5 in group R (P <0.05).Compared with group R,the colloid requirements and total requirements in group S were significantly increased(P <0.05).Compared with group R,the doses of dopamine and ephedrine,the urinary output,the inci-dence of hypotension in group S were significantly reduced(P <0.05).Conclusion SVV/CI/MAP-di-rected fluid management is safer,more effective and renders much more stable hemodynamic than the routine fluid management.