BACKGROUND: Ketamine is a kind of frequently used general venous anesthesia drug in clinic, and the medication in vein or epidural cavum has analgesic effect. It is N-methyl-D-aspartic acid (NMDA) receptor noncompetitive antagonist, which can inhibit toxic effect of excitatory amino acids.OBJECTIVE: To observe effect of ketamine on apoptosis of dorsal horn astrocytes of spinal cord of rats induced by NMDA receptor over activation and explore its possible mechanism of action.DESIGN: Randomized controlled observation.SETTING: Department of Anesthesiology, Taihe Hospital Affiliated to Yunyang Medical College.MATERIALS: The experiment was conducted at Cell Biology Laboratory,Institute of Basic Medical Sciences, Yunyang Medical College between September 2003 and January 2005. Neonatal Wistar rats of two or three days were provided by Animal Experimental Center of Wuhan University. METHODS: Primary astrocytes in dorsal horn of T11-L6 spinal cord of Wistar rats were purified and cultured. Astrocytes were used in the experiment when its purity coefficient reached 98% assessed by gial fibrillary acidic protein. The cultured cells in 24-well plates were divided randomly into 6 groups (9 portions in each group): ①50 μL Hanks liquor was added into the control group. ②Amount of 100μmol/L was added into the NMDA group. ③Amount of 1 mmol/L was added into the ketamine group. ④100μmol/L NMDA + 0.1 mmol/L ketamine group. ⑤100 μmol/L NMDA + 0.5 mmol/L ketamine group. ⑥100μmol/L NMDA + 1 mmol/L ke tamine group. 1 mmol/L ketamine was clinical antalgic dosage. Activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) were examined after 24-hour culture. Content of Bcl-2 protein and change of morphology were observed with immunocytochemistry. Apoptosis of astrocytes was measured with flow cytometry. MAIN OUTCOME MEASURES: ① Counterstain cell staining and changes of morphology of Bcl-2 protein with immunohistochemical method and hematoxylin-esoin staining (HE). ②Apoptosis of astrocytes was detected with flow cytometry. ③Content of MDA and activity of SOD.RESULTS: ①Mean absorbance (A) of Bcl-2 as expression of Bcl-2 protein measured semiquantitatively: It was lower in the 100μmoL/L NMDA group than the control group, which had significant difference [0.054±0.021,0.108±0.039, respectively, P＜0.01]. It was higher in the 100 μmol/L NMDA + 1 mmol/L ketamine group than the 100 μmol/L NMDA group,which had significant difference [0.148±0.045, 0.054±0.021, respectively,P ＜ 0.01]. ②Apoptosis of astrocytes detected with flow cytometry: It was higher in the 100μmol/L NMDA group than the control group, which had significant difference [(25.26±6.13)%, (5.66±2.24)%, respectively, P＜0.01].It was lower in the 100μmol/L NMDA + 1 mmol/L ketamine group than in the 100μmol/L NMDA group, which had significant difference[(24.41±4.82)%, (25.26±6.13)%, respectively, P＜0.01]. ③Content of MDA and activity of SOD: 100 μmol/L NMDA made the content of MDA in astrocytes obviously increase , while the activity of SOD markedly decrease. 1 mmol/L ketamine remarkably decreased the content of MDA, distinctly increased the activity of SOD. This effectiveness had evidently dosage-effect relationship in clinical antalgic dosage, which had obviously difference as compared with that of the NMDA group (P ＜ 0.01 ). The differences between the 1 mmol/L ketamine group and the control group as well as between the 100 μmol/L NMDA + 0.1 mmol/L ketamine group and the NMDA group had insignificant difference.CONCLUSION: NMDA receptor over activation can induce apoptosis of a great number of astrocytes in spinal dorsal horn of rats. Suitable ketamine dramatically inhibits apoptosis, and its mechanism can enhance the expressionof Bcl-2 protein of astrocytes, at the same time inhibit the production of free radical and reinforce the activity of SOD.

Objective: To investigate formalin-induced inflammatory nociceptive response and Fos expression of interbrain following stellate ganglion block (SGB) in rabbits. Methods: Catheters were inserted closely to right stellate ganglia in rabbits.One week later,twenty-four rabbits were randomly divided into three groups of 8 each:sham group,SGB group and control group,receiving 0.5ml of normal saline,3% formalin and 3% formalin stimulation by intraplantar injection into the right front paw, respectively. ten mins before stimulation,0.5ml of 0.25% bupivacaine was administered via the catheter in SGB group,while 0.5ml of normal saline in sham group and control group. Nociceptive response was observed for 60min using weighted pain score. Local inflammatory response was measured by histopathology, the expression of Fos of interbrain was measured with immunohistochemistry 2 hours after stimulation. Results: Formalin-induced nociceptive behavior in phase 2 and local inflammatory response were relieved following SGB; the average numbers of Fos-positive neurons of hypothalamus in SGB group was lower than that in control group( P 0.05). Conclusion: SGB suppresses formalin-induced Fos expression of hypothalamus.

Sixty-eight patients with pneumoconiosis combined with chronic obstructive pulmonary disease underwent large volume lavage in one lung under double cavity tracheal intubation and intravenousinhalant anesthesia. The vital signs of patients were recorded before, 10, 30min after and at the end of lavage. Results showed that the vital signs were stable during the lavage; and after the lavage all patients had relief significantly from the symptoms of dyspnea, polypnea and cough. Our results indicate that general anesthesia with bilateral lung ventilation are a safe and effective method in large volume whole lung lavage for treatment of pneumoconiosis patients combined with chronic obstructive pulmonary disease.

Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; methods ; Dimethyl Sulfoxide ; analysis ; Workplace

OBJECTIVETo establish a rapid determination method with gas chromatography-mass spectrometer (GC-MS) for thiodiglycolic acid (TDGA), a vinyl chloride (VCM) biomarker.

METHODSA high- sensitivity determination method was established using a moderate methyl esterification instead of methyl esterification of highly toxic diazo reaction.

RESULTSThe standard curve regression linear equation of the method was: y=8460.5x-4758.2, the linear coefficient was 0.999 7, the minimum quantity concentration was 2.0 µg/L, the range of precision value was 0.81%-2.38%, and the average recovery of standard addition was 99.0%-102.9%.

CONCLUSIONThis method reduces the risk of traditional methyl esterification, improves the determination sensitivity compared with the GC-FPD method, and meets the determination requirement of TDGA.

Objective To investigate the effect of stellate ganglion block ~SGB) on formalin-induced nociceptive behavior of rabbits, the expression of brain-derived neurotrophic factor ~BDNF) of dorsal root ganglia ~DRG) and the concentration of serum interleukin-8 ~IL-8) in rabbits. Methods Twenty-four rabbits were used in this study. Catheters were inserted closely to right stellate ganglia of the animals, which were randomly divided into control group ~A), SGB group ~B) and pain model group ~C). Group B and C were administered with an injection of 0.5ml of 3% formalin into the right front paw subcutaneously, group A 0.5ml saline by the same way. 0.5ml of (0.25)% bupivacaine was administered via the catheter in group B at 10 minutes before injection, while group A and C were given 0.5ml of saline at the same time. Nociceptive behavior was observed for 60 minutes after injection, and assessed by weighted pain score. Serum IL-8 was measured radioimmunologically at 10 minutes ~T_0) before injection, 10 ~T_1), 60 ~T_2) and 120 minutes ~T_3) after injection. The expression of BDNF in the right DRG of cervical 7, 8 and thoracic 1 was investigated immunohistochemically at 120 minutes after injection. Results Formalin-induced nociceptive behavior in phase Ⅱ was relieved following SGB. The concentration of serum IL-8 in groups B and C at T_2 and T_3 was significantly increased than that at T_0 and T_1~P

Objective To investigate the effect of penehyclidine hydrochloride (PHCD) on tramadol dependence and c-fos,△ FosB and M5 receptor expression in relevant brain regions in rats.Methods Thirty male adult SD rats weighing 180-220 g were randomly assigned to 3 groups (n =10 each):control group (group C),tramadol dependence group (group T) and PHCD group (group P).Tramadol dependence was induced by subcutaneous 10 mg/kg once a day for 7 consecutive days in groups T and P.PHCD 1.5 mg/kg was injected intraperitoneally on day 8 in group P,while in groups C and T the equal volume of normal saline was injected intraperitoneally instead of PHCD.The rats underwent conditioned place perference test at 30 min after intraperitoneal injection.The time spent in drug-paired side (gray area) was recorded.The rats were sacrificed after the conditioned place perference testand the brain was removed.The relevant brain regions (ventral tegmental area,prefrontal cortex,nucleus accumbens )were separated for determination of c-fos,△ FosB expression by Western blot and M5 receptor mRNA expression by RT-PCR.Results Compared with group C,the time spent in the drug-paired side (gray area) was significantly prolonged,and c-fos,△FosB and M5 receptor mRNA expressions were up-regulated in group T,△FosB and Ms receptor mRNA expressions were down-regulated in group P ( P ＜ 0.05 or 0.01 ).There was no significant difference in time spent in the drug-paired side (gray area) and c-fos expression between groups C and P( P ＞ 0.05).Compared with group T,the time spent in the drug-paired side (gray area) was significantly shortened,and c-fos,△ FosB and M5 receptor mRNA expressions were down-regulated in group P (P ＜0.01).Conclusion PHCD can significantly inhibit tramadol dependence by down-regulating c-fos,△FosB and M5 receptor expression in relevant brain regions.

Objective: To assess psychological acceptance and occupational stress of medical staff, analyze the relationship among personality, psychological acceptance and occupational stress and discuss the direct or indirect effects of personality to occupational stress. Methods: The gaseous four kinds of carboxylic acids in the workplace air were simultaneously collected by silica gel tube, and then desorbed by deionized water and eluted by ion chromatograph. The the content was detected by conductivity detector. Results: The linear relationship was good in the concentration range of about 0~140 mg/L. The correlation coefficient r>0.999, and the maximum detection limit was 4.5 μg/mL. The sampling efficiency of the four carboxylic acids ranges from 96.10%~100.27%. Through the sample added recovery experiments, the low and high content of the silicone tube samples were detected; and the range of desorption efficiency was 82.18%~100.12%; the range of precision was 0.70%~3.71%. Conclusion This method adopts deionized water to desorb samples, and the application of ion chromatography detection have reached the requirements of《Guidelines for the establishment of occupational health standards, Part 4: Determination of chemical substances in workplace air》, which can be used in four kinds of workplace air detection of carboxylic acid compounds.

Air Pollutants, Occupational ; analysis ; Butylene Glycols ; analysis ; Chromatography, Gas ; Workplace

Objective To explore the clinical efficacy of minimally invasive posterior reconstructive plating by parallel Kirschner wires in the treatment of unstable posterior pelvic fractures.Methods From January 2013 to December 2016,29 patients with unstable posterior pelvic fracture were treated at Trauma Center,Liuzhou Workers' Hospital.They were 22 men and 7 women,aged from 19 to 65 years (mean,44.2 years).By the Tile classification,10 cases were classified as type B and 19 as type C.The delay from injury to surgery ranged from 4 to 14 days (mean,8.7 days).All the patients received minimally invasive posterior fixation with a U-shaped reconstructive plate and parallel Kirschner wires.The length of incision,intraoperative bleeding,operation time,quality of fracture reduction,curative effects and complications at the last follow-up were recorded.Results The length of intraoperative unilateral incision ranged from 2.3 to 3.4 cm (average,2.99 cm);the volume of intraoperative bleeding ranged from 47 to 88 mL (average,69.9 mL);the average operation time ranged from 17 to 34 min (average,25.2 min).One patient was lost to the follow-up.The other 28 patients were followed up for 14 to 26 months (average,18.3 months).The fracture healing time ranged from 8 to 15 months (average,10.1 months).According to the Matta criteria for fracture reduction,17 cases were rated as excellent at the last follow-up,9 as good,one as fair and one as poor,giving an excellent to good rate of 92.9％.According to the Pohlemann functional scoring,14 cases were rated as excellent,11 as good,2 as fair and one as poor,giving an excellent to good rate of 89.3％.Conclusion In the treatment of unstable posterior pelvic fractures,minimally invasive posterior reconstructive plating by parallel Kirschner wires presents advantages of high security,limited surgical trauma,good curative effects and limited postoperative complications.