Glial cell line-derived neurotrophic factor(GDNF)is one of the numbers of neurotrophic factors.GDNF is involved in many physiological and pathological actions.Moreover,GDNF plays an important role in the neuropathic pain generation and development at central nerve system level,or at peripheral level.This paper provides an overview of the evolution of GDNF and neuropathic pain research in recent years.

Astrocyte is the most amount cell population of the central nervous system, which has complex signal transduction pathway. Astrocyte involves in many physiological actions and pathological processes. Further more, Astrocyte plays an important role in neuropathic pain generation and development at central nerve system level, or at peripheral level. This paper reviewed the evolution of astrocyte and neuropathic pain research in recent years.

After electrical stimulation of the phrenic nerve,the function of the diaphragm was assessed by measurement of the transdiaphragmatic pressure (PDi),establishment of the Pdi-sti-mulating frequency (F) curve,and analysis of the power spectrum on the diaphragmatic elec-tromyogram (EMGdi) at spontaneous breathing.Hypercapnia of the dogs was induced by forcing the animals to inhale a mixture of CO2 and air.The findings were as follows:(1) After acute hypercapnia,PDi rapidly and progressively decreased.The power spectrum of EMGdi was also reduced.The PDi-F curve was shifted to right.These findings suggest that the function of the diaphragm was severely damaged.(2) The decrease of pH value was the important cause of diaphragmatic fatigue.(3) The diaphragm in a static condition could reduce the damage of hypercapnia.(4) Cedi-lanid exerted certain effects on the prevention of diaphragmatic fatigue created by acute hypercapnia.

The study on the functions of the diaphragm has been carried on for 5 years.It consisted of the studies on the relationship of the tension and endurance of inspiratory muscles with pulmonary functions,the changes of diaphragmatic electromyogram in maximal ventilation volume test in normal subjects and patients with chronic obstructive pulmonary disease(COPD),the functional changes of the diaphragm in dogs with RDS and the therapeutic effects of aminophylline.the changes of diaphragmatic electromyogram in dogs with hypoxemia and hy-percapnia,determination of transdiaphragmatic pressure,the relationship of the stimulation frequency on the phrenic nerve with diaphragmtic fatigue,etc.It was found that there existed di-aphragmtic fatigue in dogs with RDS,in dogs with hypoxemia and hypercapnia,and in patients with COPD,and aminophylline,digoxin,salbutomal ?-receptor excitory agents can minimize or prevent diaphragmatic fatigue.

Objective To investigate the effect of intrathecal glial cell line-derived neurotrophic factor (GDNF) on p38 mitogen-activated protein kinase (p38MAPK) protein expression in the spinal cord dorsal horn in a rat model of neuropathic pain. Methods Male SD rats 6 weeks old weighing 180-200 g were used in this study.One hundred and twenty rats in which intrathecal catheters was successfully implanted were randomly divided into 4 groups ( n = 30 each): group Ⅰ control ( group C); group Ⅱ sham operation ( group S); group Ⅲ neuropathicpain (group P) and group Ⅳ GDNF. In groupⅢ and Ⅳ I6 spinal nerve was ligated. In group Ⅳ intrathecal GDNF was administered every other day for 14 d after spinal nerve ligation. In group Ⅲ normal saline was given instead. Ten animals from each group were selected at 3, 7 and 14 d after spinal nerve ligation, the mechanical pain threshold was measured, and then the rats were decapitated. The I4-6 segment of the spinal cord of the operated side was isolated. p38MAPK protein expression in the spinul dorsal horn was determined by immunohistochemistry and Western blotting. Results Intrathecal GDNF significantly attenuated spinal nerve ligationinduced increase in p38MAPK protein expression in spinal dorsal horn of the operated side. Conclusion IT GDNF can relieve neuropathic pain by inhibiting p38MAPK protein expression in the spinal dorsal horn.

Objective To investigate the effects of cytokines on the expression of angiotensin Ⅱ type 1 receptor (AT1R) in vascular smooth muscle cells (VSMCs) in rats. Methods Primary cultured VSMCs from SD rat thoracic aorta were cultured in serum-free DMEM for 24 h, and then in DMEM supplemented with 10% fetal bovine serum for another 12 h. The cultured VSMCs were randomly divided into 5 groups (n =6 each): control group (group C); 10% cytokine group (group L); 50% cytokine group (group N); 100% cytokine group (group H) and L-arginine methy ester (L-NAME), an inhibitor of nitric oxide synthase) group. In group C, the cellswere cultured continuously for 12 h. In L, N and H groups, 10%, 50% and 100% cytokines (IL-1β 50 ng/ml +TNF-α 100 ng/ml + IFN-γ 500 ng/ml) were added to the culture medium respectively and the cells were then incubated for 12 h. In group L-NAME, 100% cytokines + L-NAME 5 mmol/L were added to the culture medium and the cells were then incubated for 12 h. The expression of AT1R mPNA and protin was determined by RT-PCR and Western blot respectively.Results Cytokines down-regulated AT1R mRNA and protein expression in a concentration-dependent manner (P ＜ 0.05 or 0.01). L-NAME reversed cytokines-induced changes in AT1R mRNA and protein expression ( P ＜ 0.01). Conclusion Cytokines can down-regulate the expression of AT1R in rat VSMCs and the mechanism is related to the NO synthesis.

Objective To determine the risk factors for post-operative delirium(POD)and post-operative cognitive dysfunction(POCD)in patients undergoing spine surgery.Methods One hundred and twenty ASA Ⅰ-Ⅲ of both sexes aged 50-76 yr undergoing elective spine surgery under general anesthesia were studied.POD was assessed by Delirium Rating Scale revised 98 at 2 days after operation and the patients were assigned into POD and nonPOD group.Cognitive function was assessed by Mini-Mental State Examination(MMSE)at 1 day before and 3 days after operation.The patients were diagnosed as having POCD if MMSEpre-MMSEpost ≥ 3.The palients were assigned into POCD and nonPOCD group.Executive function and depression were assessed by stroop interference test and Beck Depression Inventory(BDI)at 1 day before operation.Age,sex,education,alcohol consumption per week,a history of psychiatric disease,ASA physical status,Charlson comorbidity score,type of anesthesia,anticholinergic drug administration and VAS score at 1 day after operation were recorded.If there was signifirant difference between the 2 groups,the factor was analyzed using multi-factor logistic regression to select risk factor for incidence of POD and POC).Results Eleven patients developed POD(9.2％)and 30 patients developed POCD(25.0％).Logistic regression model showed that lower Stroop-CW,higher BDI score,higher Charlson comorbidity score and a history of psychiatric disease were risk factors for POD,while lower Stroop-CW,higher BDI score,higher Charlson comorbidity score and higher alcohol consumption per week were risk factors for POCD.Conclusion Preoperative executive dysfunction,depression and greater preoperative comorbidity are risk factors for both POD and POCD.A history of psychiatric disease is a risk factor for POD and higher alcohol consumption is a risk factor for POCD in patients undergoing spine surgery.

Objective To investigate the extent of pancreatic and liver function damage of acute necrotizing pancreatitis (ANP) rats under altitude hypoxia environment,and to provide a reference for better diagnosis and treatment of severe acute pancreatitis (SAP) in the plateau region.Methods Ninety-six specific pathogen free (SPF) Wistar male rats were involved in 1 500 meters,3 300 meters and 4 300 meters altitude.The model of ANP was established by using pancreatic capsule injection of sodium taurocholate (NaTc).In the sham operation group,the rats' belly was opened and closed after only flipping its pancreas several times.Rats in sham group were sacrificed at 6 h,and ANP group were sacrificed at 6,12,24 h after modeling.Serum amylase activity was measured,and pancreas and liver tissue were harvested for pathological examination and score.Results Serum amylase activity in sham operation group rats was not remarkably changed,and pathological changes of pancreas and liver were not obvious.At same altitude,serum amylase activity,pancreas and liver pathology score of ANP rats at each time point were significantly higher than those in the sham operation group;and serum amylase activity,pancreas and liver pathology scores of ANP 12,24 h group rats were significantly higher than those of ANP 6h group;and the difference was statistically significant (P ＜ 0.05).At 3 300 meters,4 300 meters altitude,the pancreas and liver pathology scores of ANP rats at each time point were significantly higher than those at 1 500 meters altitude,and the differences were statistically significant (P ＜ 0.05),but the difference in serum amylase activity was not statistically significant.Conclusions With the increase of altitude,pancreatic and liver pathological damage of ANP rats shows continuing aggravation.

Objective To investigate the cause,prevention methods and curative effect on two different drainage methods of subcutaneous effusion after breast cancer surgery.Methods The clinical data of 68 cases subcutaneous effusion among 2 100 cases underwent breast cancer modified radical surgery in our hospitial were analyzed retrospectively from January 2010 to December 2016.The vacuum sealing drainage was performed in 1 032 cases and wound high negative pressure drainage system was performed in 1068 casess.Both the elastic bandage compresstion dressing didn't used.Results In 2 100 cases,68 cases of subcutaneous effusion occured (3.2％),including longitudinal incision 48 cases and transverse incision 20 cases.Among 1 068 cases of high negative pressure drainagesystem,subcutaneous effusion occured in 36 cases including 28 cases of incisional infection and 8 cases of skin flap necrosis.The extuhation time was 8-36 days,average 12 days.Among 1 032 cases of vacuum sealing drainage,subcutaneous effusion occured in 32 cases including 22 cases of incisional infection,10 cases of skin flap necrosis.The extubation time was 6-12 days,average 8 days.All cases were followed up for 3 months,no subcutaneous effusion and axillary effusion occurred.Conclusions Adequate drainage is the key to prevent subcutaneous effusion.Both vacuum sealing drainage and wound high negative pressure drainage can effectively reduce the occurrence of subcutaneous effusion,however,vacuum sealing drainage is more suitable for wounds with more exudation,larger lacuna and deeper incisions,especially the infected wound and abscess.