Objective To investigate whether human umbilical vein endothelial cells as a feeder layer was capable of supporting the growth of embryonic stem cells in vitro.Methods Human umbilical vein endothelial cells were isolated and cultured and then prepared as feeder cells after 3 passages.Alkaline posphatase activity(AKP) staining,stem cell surface marker test and karyotypes were conducted in different periods of cell culture.The suspension of stem cells cultured after 20 passages on endothelial cells were inoculated to the legs of severe combined immunodeficiency(SCID) mice subcutabeously to test the teratoma formation.Results E14.1 embryonic stem cells retained good colonies when they were cultured on endothelial cells for 3 passages and 8 passages.In addition,they expressed SSEA-1,Oct-4,and a membrane alkaline phosphatase to a high extent at passages 3 and 8.Embryonic stem cells cultured for 15 passages stably retaind a normal karyotype.Embryonic stem cells cultured on endothelial cells for 20 passages were inoculated into the hind leg of SCID mouse,teratomas containing three embryonic layers were recovered six weeks later.Conclusion Human umbilical vein endothelial cells would support effectively embryonic stem cells expansion,and provide a clinically safe method to expand ES cells for futureclinical application.

Objective: To establish the quality assessment of Cordyceps and its cultured Cmycelia by TLC fingerprint, and to compare the content of the nucleotides between them. Methods: Adenosine, Uridine and Guannosine were detemined by TLC-Scanning samples were perfomed by fluorescence quenching analyis. Results: The contents of adenosiue, uridine, and guanosine from cordyceps mycelia were more than that of cordyceps from wildlife. Conclusion: This method is convenient and rapid, and it can effectively evaluate nucleotides in nature Cordyceps and culture Cordyceps.

OBJECTIVETo investigate the feasibility of urinary ortho-cresol levels as a biological monitoring indicator for toluene exposure.

METHODSEstablish pre-column derivation HPLC method to detect ortho-cresol levels in urine of human body. Ortho-cresol levels in urine of workers non-exposed and exposed to toluene was examined using this pre-column derivation HPLC method, and exposure assessment was conducted.

RESULTSIt was shown that urinary ortho-cresol level in exposed workers was (2.61 +/- 1.94) mg/L, higher than those of control group [(0.32 +/- 0.23) mg/L, P < 0.001]. Urinary ortho-cresol level in exposed workers at the end of a workshift was higher than those before exposure to toluene, and also was correlated with the concentration of toluene to which individual exposed(r = 0.6295, P < 0.01).

CONCLUSIONUrinary ortho-cresol as a biological monitoring indicator for toluene exposure is feasible.

BACKGROUND: Ultra-high molecular weight polyethylene (UHMWPE) is widely used as acetabulum. The hip joint will produce lots of grind particles and lead to loosening of artificial joint because of alternating load and bad lubricate condition.OBJECTIVE: To learn about the lubricate mechanism of joint, introduce the present situation on artificial hip joint of UHMWPE including wear behavior and wear resistance properties, and grope for scientific evaluate method of tribological properties in artificial joints.RETRIEVAL STRATEGY: The articles published between January 2000 and October 2007 were searched by using computer with the key terms "hip joint, ultra-high molecular weight polyethylene, tribology" in CNKI, Weipu Science and Technology Database, Wanfang Database, and its language was limited to Chinese. Meanwhile, the English articles were searched in IEEE/IEE Electronic Library and Elsevier Electronic Journal Database with the key terms "hip simulators, ultra-high molecular weight polyethylene, tribology ". Those referring to the friction and wear property of the joints were included, whereas repeated researches were deleted.LITERATURE EVALUATION: Totally 729 articles were received. After the primary screening of the titles and abstracts, 601 repeated or similar researches were excluded, and other 128 articles were adopted for further analysis, finally 22 articles in accordance with the inclusion criteria were included as references.DATA SYNTHESIS: The study about UHMWPE focused two points, one is surface modification, the other is wear and friction mechanism.①The study indicates that wear properties of UHMWPE can be improved by surface modification, such as ion implantation and nanometer padding have a remarkable elevating ability of the wear and mechanical properties.②At recent years, scholars do many basal experiences about the tribology of hip joints, and have approved that wear rate of friction pairs would reduce under biological lubricate condition using artificial joint simulators or traditional tester in various conditions.CONCLUSION: The study about hip joint in China drops behind the developed counties, this traditional method can not really reflect wear and friction properties in vivo. Therefore, the following research should include making clear the relationships of load, environmental condition and wear of artificial joint in vivo, as well as groping for a scientific evaluate method of tribological properties in hip joints.

Objective:To evaluate the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative delirium (POD) in frail elderly patients.Methods:Sixty frail elderly patients of both sexes, aged 65-80 yr, with body mass index of 18.5-30.0 kg/m 2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, with preoperative Fried frailty phenotype scale≥3, were divided into 2 groups ( n=30 each) using a random number table method: control group (group C) and TEAS group.In group TEAS, patients received TEAS of Shenmen, Neiguan and Zusanli acupoints starting from 30 min before anesthesia induction until the end of surgery.The frequency was 2/100 Hz, wave length was 0.25 ms and the intensity was maintained at about 1-30 mA according to the current that could be tolerated.The same acupoints were continuously stimulated for 30 min at 24, 48 and 72 h after operation.Electroacupuncture was performed for 30 min at the points 4 cm lateral to the same acupoints in group C. The occurrence of POD was evaluated by Confusion Assessment Method at 1-7 days after surgery.The intraoperative consumption of propofol, remifentanil and sufentanil, the effective pressing times of patient-controlled intravenous analgesia (PCIA) pump, the requirement for rescue analgesia at 0-8 h (T 1), 8-24 h (T 2) and 24-48 h (T 3) after operation and the development of rescue analgesia, POD, postoperative nausea and vomiting (PONV) and somnolence after operation were recorded. Results:Compared with group C, requirement for rescue analgesia and the incidence of POD, PONV and somnolence after operation were significantly decreased, and intraoperative consumption of propofol and remifentanil and the postoperative effective pressing times of PCIA at T 1-3 were decreased in group TEAS ( P<0.05). Conclusion:TEAS can reduce the occurrence of POD in frail elderly patients.

Objective To evaluate the role of autophagy in apoptosis of neurons in brain tissue of rats induced by mechanical ventilation. Methods A total of 24 healthy adult male Wistar rats were divided into 4 groups (n = 6) by random number table method, including control group (C group), mechanical ventilation group (MV group), mechanical ventilation combined with 6-amino-3-methylindole treatment group (3 MA group), and mechanical ventilation plus rapamycin treatment group (R group). Group C retained spontaneous breathing after endotracheal intubation without mechanical ventilation. MV group, 3 MA group and R group were performed mechanical ventilation.3 MA group and the R group received intraperitoneal injection of 30 mg/kg 3-MA and 1 mg/kg rapamycin, respectively, at 15 min before MV, while the C group was given intraperitoneal injection of the same amount of normal saline at 15 min before MV. At the end of mechanical ventilation, 6 rats were sacrificed for brain tissue to observe pathological changes under light microscope. TUNEL assay was used to detect the apoptosis of neurons in the hippocampus CA1 region and calculate the apoptosis index. Using Western blot method to detect the expression of Bax, Bcl-2, activated Caspase-3, LC3Ⅰ, LC3 Ⅱ, p62, and calculate the ratios of Bax to Bcl-2, LC3 Ⅱ to LC3 Ⅰ. Results Compared with group C, the rest three groups had severe pathological damage, with higher hippocampus neuron apoptosis index and Bax/Bcl-2 ratio, up-regulated expression of activated Caspase-3, increased Beclin-1, LC3Ⅱ/Ⅰand decreased p62 (P ＜ 0. 05); compared with MV group, pathological damage, the hippocampus neuron apoptosis index and Bax/Bcl-2 ratio, the expression of activated Caspase-3, Beclin-1, LC3 Ⅱ/Ⅰwas decreased, p62 was up-regulated in 3 MA group (P ＜ 0. 05); compared with MV group, the changes of above indicators in the R group was contrary to 3 M group (P ＜ 0. 05).Conclusion Autophagy is involved in the apoptosis of neurons in rat brain tissue induced by high tidal volume ventilation.

Objective To explore the influence of electroacupuncture preconditioning on cognitive function and adenosine monophosphate-activated protein (AMPK) signaling pathway in depression model rats after electroconvulsive therapy (ECT). Methods Totally 75 male sprague-dawley rats were randomly divided into normal control group (groupⅠ), model group (group Ⅱ), electroconvulsive therapy group (group Ⅲ), electroacupuncture + electroconvulsive therapy group (groupⅣ), false electroacupuncture + electroconvulsive therapy group (group Ⅴ), with 15 rats in each group. GroupⅡ ～ Ⅴ were treated by chronic unpredictable mild stress (CUMS) to establish model of depression. After successful modeling, all rats in the four groups were anesthetized with 100 mg/kg by intra-peritoneal injection of propofol. Group Ⅱ was treated by anesthesia without electroconvulsive therapy, the other three groups were treated by electroconvulsive therapy. Group Ⅳ was treated by electric acupuncture at Bai hui (GV20) and Yin tang (GV29) acupoint for 30 minutes before ECT.Group Ⅴ was treated by false electric acupuncture at 5 mm next to Bai hui (GV20) and Yin tang (GV29) acupoint for 30 minutes before ECT. The rats were kept adaptively feeding for seven days, then the experiment started (the first day of the experiment). Morris water maze test (positioning navigation experiment and space exploration experiment) was carried out on the 1 stday, the 28 thday and the 40 thday of the experiment respectively. On the 6 thday, the 33 rdday and the 45 thday of the experiment, 5 rats in each group were randomly selected. After the rats were sacrificed, the expressions of AMKP and phosphorylated AMKP (p-AMKP) in the hippocampus were determined by Western blot method. Results Compared with group Ⅰ, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with the result on 5 thday, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with group Ⅲ, the escaping latency and the swimming path shortened obviously and the crossing platform significantly increased on the 44 thday in group Ⅳ, and there were significant differences (P ＜0. 05). Compared with group Ⅰ, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with the results on 5 thday, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32 ndday in group Ⅱ toⅤ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with groupⅢ, the expressions of AMPK and p-AMPK in hippocampus increased obviously on 44 thday in groupⅣ, and there were significant differences (P ＜0. 05). Conclusion Electroacupuncture preconditioning can improve the learningand memory ability of depression model rats after electroconvulsive therapy, and has a good anti-depressant effect. The mechanism may be related to the up-regulation of the expression of AMPK signaling pathway in the hippocampus.

Objective To evaluate the role of autophagy in apoptosis of neurons in brain tissue of rats induced by mechanical ventilation. Methods A total of 24 healthy adult male Wistar rats were divided into 4 groups (n = 6) by random number table method, including control group (C group), mechanical ventilation group (MV group), mechanical ventilation combined with 6-amino-3-methylindole treatment group (3 MA group), and mechanical ventilation plus rapamycin treatment group (R group). Group C retained spontaneous breathing after endotracheal intubation without mechanical ventilation. MV group, 3 MA group and R group were performed mechanical ventilation.3 MA group and the R group received intraperitoneal injection of 30 mg/kg 3-MA and 1 mg/kg rapamycin, respectively, at 15 min before MV, while the C group was given intraperitoneal injection of the same amount of normal saline at 15 min before MV. At the end of mechanical ventilation, 6 rats were sacrificed for brain tissue to observe pathological changes under light microscope. TUNEL assay was used to detect the apoptosis of neurons in the hippocampus CA1 region and calculate the apoptosis index. Using Western blot method to detect the expression of Bax, Bcl-2, activated Caspase-3, LC3Ⅰ, LC3 Ⅱ, p62, and calculate the ratios of Bax to Bcl-2, LC3 Ⅱ to LC3 Ⅰ. Results Compared with group C, the rest three groups had severe pathological damage, with higher hippocampus neuron apoptosis index and Bax/Bcl-2 ratio, up-regulated expression of activated Caspase-3, increased Beclin-1, LC3Ⅱ/Ⅰand decreased p62 (P ＜ 0. 05); compared with MV group, pathological damage, the hippocampus neuron apoptosis index and Bax/Bcl-2 ratio, the expression of activated Caspase-3, Beclin-1, LC3 Ⅱ/Ⅰwas decreased, p62 was up-regulated in 3 MA group (P ＜ 0. 05); compared with MV group, the changes of above indicators in the R group was contrary to 3 M group (P ＜ 0. 05).Conclusion Autophagy is involved in the apoptosis of neurons in rat brain tissue induced by high tidal volume ventilation.

Objective To explore the influence of electroacupuncture preconditioning on cognitive function and adenosine monophosphate-activated protein (AMPK) signaling pathway in depression model rats after electroconvulsive therapy (ECT). Methods Totally 75 male sprague-dawley rats were randomly divided into normal control group (groupⅠ), model group (group Ⅱ), electroconvulsive therapy group (group Ⅲ), electroacupuncture + electroconvulsive therapy group (groupⅣ), false electroacupuncture + electroconvulsive therapy group (group Ⅴ), with 15 rats in each group. GroupⅡ ～ Ⅴ were treated by chronic unpredictable mild stress (CUMS) to establish model of depression. After successful modeling, all rats in the four groups were anesthetized with 100 mg/kg by intra-peritoneal injection of propofol. Group Ⅱ was treated by anesthesia without electroconvulsive therapy, the other three groups were treated by electroconvulsive therapy. Group Ⅳ was treated by electric acupuncture at Bai hui (GV20) and Yin tang (GV29) acupoint for 30 minutes before ECT.Group Ⅴ was treated by false electric acupuncture at 5 mm next to Bai hui (GV20) and Yin tang (GV29) acupoint for 30 minutes before ECT. The rats were kept adaptively feeding for seven days, then the experiment started (the first day of the experiment). Morris water maze test (positioning navigation experiment and space exploration experiment) was carried out on the 1 stday, the 28 thday and the 40 thday of the experiment respectively. On the 6 thday, the 33 rdday and the 45 thday of the experiment, 5 rats in each group were randomly selected. After the rats were sacrificed, the expressions of AMKP and phosphorylated AMKP (p-AMKP) in the hippocampus were determined by Western blot method. Results Compared with group Ⅰ, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with the result on 5 thday, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with group Ⅲ, the escaping latency and the swimming path shortened obviously and the crossing platform significantly increased on the 44 thday in group Ⅳ, and there were significant differences (P ＜0. 05). Compared with group Ⅰ, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32 ndday in group Ⅱ to Ⅴ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with the results on 5 thday, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32 ndday in group Ⅱ toⅤ and the 44 thday in group Ⅱ, Ⅲ, Ⅴ. Compared with groupⅢ, the expressions of AMPK and p-AMPK in hippocampus increased obviously on 44 thday in groupⅣ, and there were significant differences (P ＜0. 05). Conclusion Electroacupuncture preconditioning can improve the learningand memory ability of depression model rats after electroconvulsive therapy, and has a good anti-depressant effect. The mechanism may be related to the up-regulation of the expression of AMPK signaling pathway in the hippocampus.

Objective:To investigate the status of occupational stress and its influencing factors among undergraduate interns.Methods:Three hundred and seventeen interns in Subei People's Hospital of Jiangsu Province were collected as research objects. In this study, the Job Content Questionnaire (JCQ), Effort-Reward Imbalance (ERI) Questionnaire and self-compiled general information questionnaire were used to evaluate the status of occupational stress and its influencing factors, and the regression analysis was carried out.Results:The results showed that 101 (31.9%) and 115 (36.3%) undergraduate interns were in significantly higher level occupational stress according to the JCQ and the ERI questionnaire respectively. Logistic regression analysis showed that the risk factors of the included occupational stress included the planning of further studies, more than 40 hours per week for internship, high score of intrinsic engagement and low score of social support. Exercise of more than three times a week was a protective factor for interns' occupational stress.Conclusion:The occupational stress of the undergraduate interns is at a high level and affected by many factors. Schools and hospitals should provide targeted mental health education for interns and improve relevant management policies.