Myasthenia gravis is an autoimmune disease resulting from the production of antibodies against acetylcholine receptors of the endplate. These antibodies impair postjunctional membrane and reduce the number of functional acetylcholine receptors of endplate. Thymectomy is an effective therapeutic method for adult myasthenic patients. In this paper, the author reviewed the pathophysiological characteristics and problems related to anesthesia, such as preoperative evaluation, the effect of preoperative medical treatment on the anesthesia, patients'response to muscle relaxants and postoperative management.

Objective To study the effect of intra-articular injection of dehydroepiandrosterone (DHEA) on the balance of ADAMTS/TIMP-3 system in a rabbit osteoarthritis models.Methods Sixty rabbits were underwent bilateral anterior cruciate ligament transection (ACLT).Rabbits were randomizedn to the following treatment:one knee of each rabbit was treated with 100 μmol/L DHEA dissolved in dimethylsulphoxide (the experimental group) and the other knee was treated under the same schedule using dimethylsulphoxide (the control group) 4 weeks after transection,once a week for eight weeks.Twelve weeks after ACLT,all rabbits were killed after X-ray assessment and the knee joints were evaluated by gross morphology and histology.The concentration of hydroxyproline and glycosaminoglycan in the cartilage were analyzed.The mRNA expression of ADAMTS-4,ADAMTS-5,tissue inhibitor of metalloproteinases-3 (TIMP-3),transforming growth factor (TGF)-β1.Aggrecan and Collagen Ⅱ in the cartilage were analyzed using reverse transcription polymerase chain reaction (RT-PCR).The protein expression of aggrecan ARGxx and Collagen Ⅱ in the cartilage were analyzed by Western blot.Results By Mann-Whitney test,Gross morphologic scores on femoral condyle and tibial plateau in the control group were significantly higher than the experi-mental group (Z=-3.517,P＜0.01 ; Z=-2.518,P＜0.05).By unpaired Student's t test,histological evaluation showed that the grade of cartilage damage in the experimental group [(5.3±1.2) μg/ml] were less severe than that in the control group (10.1 ± 1.3,P＜0.01).The concentration of hydroxyproline [(5.7±0.3,23.6± 1.7) μg/ml] and glycosaminoglycan (30±4) in the experimental group increased significantly when compared with the control group [(4.6±0.5),(18.5±1.4),(24±4) μg/ml,P＜0.01].The mRNA expression of ADAMTS-4 (0.15±0.03)and ADAMTS-5 (0.10±0.04) in the experimental group decreased significantly compared with the control group (0.29±0.08,0.15±0.05; all P＜0.05).The mRNA expression of TIMP-3 (0.85±0.10),TGF-β1(1.2±0.4),Aggrecan (0.87±0.31) and Collagen Ⅱ (2.74±0.59) in the experimental group increased significantly when compared with the control group (0.70±0.13,0.8±0.4,0.49±0.16,2.2±0.5; all P＜0.05).The protein expression of Aggrecan ARGxx (0.53±0.10) in the experimental group decreased significantly when compared with the control group (0.81±0.12,P＜0.01).The protein expression of Collagen Ⅱ (2.3±0.7) in the experimental group increased significantly when compared with the control group (1.7±0.5,P＜0.05).Conclusion DHEA protects against cartilage degradation and inhibits the progression of OA,TGF-β1,Aggrecan and Collagen Ⅱ in cartilage may be the mechanism of the protective effect of DHEA on OA.

Objective To explore the safety and outcomes of thoracoscopic esophagectomy for esophageal cancer.Methods The clinical data of 22 patients with esophageal cancer received thoracoscopic minimally invasive esophagectomy ( study group ) were retrospectively analyzed and compared with 46 patients underwent conventional open thoracic esophagectomy( control group) .The medium-term clinic outcomes of the two groups were compared. Results Compared to the control group,the study group showed significantly longer operation time[(183 ±37)mins vs (239 ±41)mins,t=6.19,P=0.002],less intraoperative blood loss[(95 ±33)mL vs (115 ±27)mL,t=5.04, P=0.004],shorter postoperative hospital stay[(15.8 ±6.2)d vs (17.5 ±7.1)d,t=5.62,P=0.003],and more removed lymph nodes[(11.6 ±4.2) vs (10.3 ±5.8),t=-3.19,P=0.018)].No significant difference was observed in the survival rate between the two groups (χ2 =0.358,P=0.449) .Conclusion There is no difference in medium-term clinic outcomes between the two kinds of esophagectomy.The patients with esophageal cancer received thoracoscopic minimally invasive esophagectomy has less complication and quick recovery.And the technology should be widely applied.

Objective To study the paracrine effect of hypoxic preconditioned umbilical cord mesenchymal stem cells (UCMSCs) on the proliferation,migration and osteogenic differentiation of osteoblasts.Methods UCMSCs were cultured under hypoxia and normal oxygen condition before two UCMSCs conditioned media were obtained.After that,MG-63 cells were cultured in three groups:hypoxia conditioned medium group,normoxia conditioned medium group and DMEM control group.The proliferation of MG-63 cells was detected by mosmann tetrazoline colorimetry( MTT) method after 1,3 and 5 days.The migratory ability of MG-63 cells was detected by scratch assay .After 21 days′culture , the formation of osteogenic calcium nodules was detected by Alizarin red staining.ELISA method was used to detect the content of vascular endothelial growth factor ( VEGF) in hypoxia and normoxia conditioned medium.Results The MTT test showed that the proliferation ability of MG-63 cells in hypoxia conditioned medium group and normoxia conditioned medium group was greater than in the DMEM control group.The difference was statistically significant ( P <0.05).Furthermore, the proliferation ability of cells in hypoxia conditioned medium group were much greater than cells in normoxia culture medium group.The difference was statistically significant (P<0.05).Scrath assay showed that the migratory ability of MG-63 cells in hypoxia conditioned medium group and normoxia conditioned medium group was greater than cells in DMEM control group,and cells in hypoxia conditioned medium group was much greater than cells in normoxia conditioned medium group. After 21 days′culture,we found that the number of calcium nodules was the largest in hypoxia conditioned medium group, followed by normoxia conditioned medium group and DMEM control group.ELISA showed that the content of VEGF in hypoxia conditioned medium was higher than that in normoxia conditioned medium and the difference was statistically significant (P<0.01).Conclusion The paracrine function of UCMSCs can be enhanced by hypoxia,thus improving the proliferation,migration and osteogenic differentiation of osteoblasts.

Objective To observe the morphologic protection effect of intra-articular injection of osteoprotegerin (OPG)on articular cartilage in a rabbit model of osteoarthritis (OA).Methods Sixty male New Zealand rabbits were randomly divided into 3 groups:OPG group (n=20),sham-operated group (n=20) and PBS group (n=20).In OPG group and PBS group,each rabbit underwent anterior cruciate ligament transection (ACLT) in left knee joint,then 0.1 ml OPG solution or PBS were injected into the left knee for 8 weeks (5 times a week) in OPG group and PBS group,respectively.In sham-operated group,the anterior cruciate ligament was just exposed without transection,and then the incision was closed.All rabbits were sacrificed 12 weeks after operation,and the left knee joints were obtained.The Pelletier score and Mankin score were used to evaluate the macroscopic and microscopic cartilage morphology.Results The score of femoral condyle cartilage and tibial plateau cartilage was 1.80±0.89 and 1.80±0.77 in OPG group,respectively,and 3.10±0.97 and 3.20±0.77 in PBS group.However,there was no statistical difference in Pelletier score between the sham-operated group and the OPG group.Consistent with the macroscopic data,the OPG group has a significantly lower Mankin score involving cartilage structure (2.65±0.88),chondrocyte (1.35±0.71),Safranin O staining (1.83±0.83),tidemark integrity (0.30±0.47) and total score (6.13±1.97) compared with the PBS group (4.52±1.09,1.85±0.63,2.80±0.75,0.65±0.49,and 9.83±1.98,respectively).The OPG group has a significantly higher total Mankin score compared with the sham-operated group (4.80±1.25),however,there were no statistical differences in four subitem scores between the two groups.Moreover,the cartilage thickness in OPG group was 371.84±38.94 μm,255.09±74.82 μm in PBS group,and 404.68±15.97 μm in the sham-operated group,and the differences were statistically significant between three groups.Conclusion OPG has a protective effect on articular cartilage and can slow the progression of OA by reducing the grade of synovitis,decreasing the volume of osteophytes,and suppressing the loss of cartilage thickness.

Objective:To investigate the effects of propofol on cerebrospinal fluid pressure(CSFP),mean arterial pressure(MAP),cerebral perfusion pressure(CPP) and heart rate(HR)during induction of anesthesia in patients underwent intracranial operation. Methods: In 20 patients scheduled for elective craniotomy, an epidural catheter was placed into subarachanoid. Fentanyl(2 ?g/kg), intravenousl Midazolam (0.04~0.05mg/kg) and propofol (2mg/kg) were administered respectively prior to induction of anesthesia. CSFP,MAP,CPP and HR were monitored at 2min,5min after propofol administration and 2,5,10min after another supplementary dose of propofol 1mg/kg addendum during endotracheal intubation. Results: Compared with the preanesthetic baseline values, CSFP, CPP, and MAP all decreased significantly during induction(P

Objective To study the clinical significance of the injury and functional change of hypothalamic-pituitary-adrenal (HPA) axis after acute severe traumatic brain injury (TBI) in the rats.Methods A total of 60 adult healthy male Spraque-Dawley rats were randomly (random number) divided into 3 groups (n =20 in each group):sham operation group,model group and treatment group.The TBI models of rats were established by Feeney' s method.A low dose of dexamethasone (0.6 mg/kg) was injected into the abdominal cavity 20 minutes,24 hours and 48 hours after injury in treatment group,while rats of sham operation group and model group received equal volume of normal saline instead.All the rats were injected 1 μg adrenocorticotropic hormone (ACTH) into the abdominal cavity.The related parameters were detected at four time points,3 hours,12 hours,24 hours and 72 hours after cerebral contusion.The plasma corticosterone (CORT) and ACTH levels were measured by chemiluminescence.The hypothalamic,pituitary and adrenal of the rats were taken out for observing interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression detecting by immunohistochemical techniques at 72nd hour after TBI.One-way ANOVA and SNK-q test were used to analyze the results with SPSS 17.0 software package.Results The levels of ACTH and CORT on 3rd hour of model group raised remarkably compared with that of sham operation group,then they reduced gradually.The levels of CORT were lower than that of sham operation group at every time points after ACTH stimulation test (P ＜0.05 or P ＜0.01).The levels of CORT at all time points of treatment group were changed remarkably compared with that of model group.However,the ACTH levels of treatment group on 24 h increased slightly than that of model group.And the tendency of them was similar to model group (P ＜ 0.05 or P ＜ 0.01).The number of the hypothalamus and pituitary cells which express IL-6 and TNF-α in model group was more significantly increased when compared with that in sham operation group (P ＜ 0.01),while the number of this kind of cell in treatment group was significantly decreased than that in model group (P ＜ 0.01).The number of the adrenal cortex cells which express IL-6 in treatment group was more significantly decreased when compared with that in model group (P＜ 0.01),while the number of this kind of cell in model group was significantly increased than that in sham operation group (P ＜ 0.01).However,there was no significant difference of the TNF-α between all the groups (P ＞ 0.05).Conclusions Functional change of adrenal occurs early in the severe acute traumatic brain injury rats,and the response of adrenal to ACTH decreased as time goes by.Low-dose,short-course dexamethasone can delay the pathological changes,reduce the inflammatory response of HPA axis and increase the sensitivity of adrenal response to ACTH.

Objective To predict a value of ischemia modified albumin (IMA) levels for assessing secondary cerebral infarction in patients with transient ischemic attack (TIA) in anterior circulation.Methods 105 patients with TIA in anterior circulation admitted to the hospital within 3 hours were retrospectively studied.Combined with ABCD2 score,the correlations of IMA levels at 3 h,6 h and 12 h with secondary cerebral infarction after anterior circulation TIA were analyzed.Results IMA level was 75.28 u/L within 3h after TIA,and the sensitivity and specificity of TIA in anterior circulation were 66.7％ and 76.2％ respectively.In the total of 105 patients,16 cases (15.2％) suffered from secondary cerebral infarction within 7d,and 21 cases (20.0％) within 8～30d.The serum IMA levels were (87.43±19.89)U/L,(63.88±12.51)U/L and (61.21±12.28)U/L at 3h,6h and 12h after TIA,respectively.A simple analysis showed that there was a linear correlation between the IMA level and ABCD2 scores (P=0.000,r=0.666).Kaplan-Meier survival curve analysis showed that the increased IMA level within 3h,and moderate to high ABCD2 score were the risk factors for secondary cerebral infarction after TIA in anterior circulation (P=0.012,0.041).Conclusions Early detection of IMA has a clinical value similar to ABCD2 score to predict secondary cerebral infarction in patients with TIA in anterior circulation.

Cone beam CT(CBCT)data of 4 550 impacted mandibular third molars were divided into 6 groups by the direction of teeth im-paction.Analyzed by SPSS 19.0 statistical package and Pearson Chi-square Test,the incidence of disto-lingual roots was 5.38% and was various with different impation direction.

Objective To study the results of functional hemispherectomy for pediatric intractable epilepsy with hemisphere lesions , and to explore the indications of functional hemispherectomy , as well as the prognosis. Methods Twenty-four children with intractable epilepsy caused by hemisphere lesions were included , who underwent functional hemispherectomy. All patients were followed up for 3 ~ 48 months. Results All 24 cases obtained improvement of abnormal behavior , and no significant exacerbation of neurological deficits was observed. During the follow-up, 18 cases were in EngelⅠ(75%), 5 in Engel Ⅱ(21%), and 1 in Engel Ⅰ(4%) respectively. No long-term complication was observed. Conclusion Comprehensive presurgical evaluation is a prerequisite for the surgical treatment of pediatric intractable epilepsy caused by hemisphere lesions. Functional hemispherectomy can effectively control seizures and obviously improve the prognosis.