BACKGROUND: The extracellular signal-related kinase(ERK) cascade is activated by its specific upstream kinase MAPK/ERK kinase(MEK) and identified as a critical regulator of cell growth, memory formation and long-term neuronal plasticity.OBJECTIVE: To investigate the role of ERK activation in establishment and maintenance of chronic neuropathic pain.DESIGN: A randomized controlled experiment based on the animals.SETTING: Department of Anesthesiology of a university-affiliated hospital.MATERIALS: The experiment was performed in the Medical Institute of Anesthesiology of Jiangsu Province from September 2003 to June 2004. Totally 115 male clean SD rats weighting 220 to 300 g were provided by the Experimental Animal Center of Xuzhou Medical Colleg e. The rats were raised in separate cages with natural lighting at 20 to 25 ℃, having free access to food and water.INTERVENTIONS: Five days after chronic constrictive injury(CCI) model was established, different doses of U0126 were intrathecally injected according to Mestre' s method. The control group received sterile intrathecal injection of 50 g/L dimethylsulfoxide.hyperalgesia by using von Frey filaments and thermal hyperalgesia stimulator activation and translocation of ERK in spinal cord dorsal horn by immunohistochemistry and Western blot analysis.RESULTS: CCI could increase the activity of EPK in spinal cord dorsal horn. Intrathecal injection of U0126 significantly attenuated CCI-induced mechanical and thermal hyperalgesia.CONCLUSION: Activation and translocation of ERK contribute to formation and maintenance of CCI-induced neuropathic pain.

Objective To explore the application value of diffusion-weighted imaging(DWI) in distinction of skull base chordoma from chondrosarcoma.Methods The clinical data and imaging findings of basicranial tumor confirmed by pathology,including 14 patients with classic chordoma,9 with poorly differentiated chordoma and 18 with chondrosarcoma were analyzed retrospectively.The lesion location,enhancement patterns,signal intensity on T2 WI relative to gray matter,and apparent diffusion coefficient (ADC) values were reviewed.The enhancement pattern was scored as 0 (little or non-enhancement),1 (heterogeneous enhancement),or 2 (homogeneous enhancement in ≥90％area).The data were analysed by Kruskal-Wallis test.Results There were significant differences in the mean,minimum and maximum ADC values,the intensity on T2 WI and the enhancement pattern among the three tumor types (P ＜0.05).However,the differences in the score of enhancement pattern and lesion location were not found (P＞0.05).Conclusion DWI may be helpful for the diagnosis of skull base chordoma from chondrosarcoma,and the accuracy rate will be improved when combined with T2WI intensity.

Objective To develope energic spectrum of super-large solar particle events (SPE),human body model and a Monte Carlo method for estimating the organ dose of astronauts in SPE without the shielding of geomagnetic field. Methods A voxel-based human phantom and shielding model of spacecraft were developed and the Monte Carlo program was compiled and applied to calculate the doses of astronaut's organs with the transport protons of the spectra of super-large SPEs in 1956 and 1972, normalized by the proton fluence for energy greater than 30 MeV. Results The Monte Carlo program was developed successfully and the organ dose under different shielding thickness were also calculated with the program in the normalized spectra of SPEs in 1956 and 1972 without the effects of geomagnetic field. They were similar with prior studies. Conclusion The results are reliable by the comparison with other calculations of prior researchers. Exposure to super-large SPE without the shielding of geomagnetic field would result in a very large organ absorbed dose and may be very danger for manned spaceflight.

To investigate the effect of propofol on the release of glutamate and gamma-aminobutyric acid (GABA) from rat hippocampal synatosomes, synaptosomes was made from hippocampus and incubated with artificial cerebrospinal fluid (aCSF). With the experiment of Ca(2+)-dependent release of glutamate and GABA, dihydrokainic acid (DHK) and nipectic acid were added into aCSF. For the observation of Ca(2+)-independent release of glutamate and GABA, no DHK, nipectic acid and Ca2+ were added from aCSF. The release of glutamate and GABA were evoked by 20 micromol/L veratridine or 30 mmol/L KCI. The concentration of glutamate and GABA in aCSF was measured by using high-performance liquid chromatography (HPLC). 30, 100 and 300 micromol/L propofol significantly inhibited veratridine-evoked Ca(2+)-dependent release of glutamate and GABA (P < 0.01 or P < 0. 05). However, propofol showed no effect on elevated KCl-evoked Ca(2+)-dependent release of glutamate and GABA (P > 0.05). Veratridine or elevated KCI evoked Ca(2+)-independent release of glutamate and GABA was not affected significantly by propofol (P > 0.05). Propofol could inhibit Ca(2+)-dependent release of glutamate and GABA. However, it has no effect on the Ca(2+)-independent release of glutamate and GABA.
Anesthetics, Intravenous/pharmacology ; Calcium/metabolism ; Glutamic Acid/*biosynthesis ; Hippocampus/*metabolism ; Propofol/*pharmacology ; Rats, Sprague-Dawley ; Synaptosomes/*metabolism ; gamma-Aminobutyric Acid/*biosynthesis

OBJECTIVE:To investigate the effect and clinical significance of radiotherapy on the expression of multidrug resistance-associated protein(MRP) in advanced cervical cancer.METHODS:The immunohistochemistry method was applied to detect the expression of lung resistance protein(LRRP),glutathione-S-transferases-?(GST-?),thymidylate synthetase(TS) and type Ⅱ topoisomerase(TopoⅡ) in 23 patients with advanced cervical cancer before radiotherapy and after receiving 30 Gy dose radiation.RESULTS:The positive expression rates of LRRP,GST-?,TS and TopoⅡ before radiotherapy were 47.8%,56.5%,30.4% and 60.9%,respectively.The positive expression rates of LRRP,GST-? and TS in patients after 30 Gy dose radiation were 69.6%,73.9% and 73.9%,respectively,which were signficantly higher as compared before radiotherapy(P

Objective To investigate the effects of drag-reducing polymers on microcirculation in 40%total body surface area burn-injured rats. Methods SD rats were randomized into control group, drag-reducing polymer (DRPs) group and normal saline (NS) group (5 minutes after scald, drag-reducing polymer or saline was injected for fluid resuscitation). Wet dry weigh ratio of lung, histopathologic changes and arterial blood gas at 24 hour were respectively measured by wet dry weigh ratio method, hematoxylin-eosin (HE) staining and arterial blood gas analysis. The velocity of flow of red cell in oblique ridge and the survival time of burn-injured rats were observed. Results Compared with control group, rats in NS group exhibit significant lung injury characterized by a high W/D (P < 0.01), accumulation of a large number of neutrophils in HE stain, low partial pressure of oxygen (PO2) and high lactate (Lac) (P<0.05 or P<0.01) in arterial blood. Compared with the NS group, DRPs treatment rats exhibit significantly reduced lung injury characterized by W/D reducing (P < 0.05), the reduction of neutrophil infiltration, increased PO2, decreased Lac (P<0.05, P<0.01). In addition, DRPs treatment obviously increases the burn-induced low velocity of flow of red cell in oblique ridge (P<0.01). Moreover, the survival time of burned rats can be improved by DRPs treatment (P < 0.05). Conclusion DRPs ameliorates burn-induced acute lung injury, the mechanism may be through improving the burn-induced microcirculation disorders.

Objective To predict the astronaut organs radiation exposure and related health risks in the space radiation environment, the calculated method is studied. Methods A male voxel human model based on MRI and radiation data bank was build. The calculation was carried out with Monte Carlo particle transporting program GEANT4. Results The organ absorbed dose distribution and the effec-tive doses to the model in isotropic proton fields with energies ranges from 10 MeV to 500 MeV were obtained. Conclusion Based on the Chinese astronaut voxel model and the data set of proton spectrum measured in the space cabin, the cumulated dose in the model is gotten. The calculated skin dose is about 148.6 μGy/d, which is within in the range of 100 -300 μGy/d, published by USA and Russia.

Objective To investigate the therapeutic effect and advantage of laparoscopic appendectomy by concealed three-ports technique. Methods The clinical data of 283 patients received concealed three-ports laparoscopic appendectomy were retrospectively reviewed. Results All the patients were cured after appendectomy,including 5 patients required conversion to operation(because of adhesions around the appendix and difficult to dissect). The surgical time ranged from 25 min to 110 min and the mean time was 38 min. After 8 ～ 12h the patients could move and the average length of postoperative stay was 5d (range 4 ～ 6d). 3 cases had postoperative wound infection. None occurred complications such as postoperative bleeding, abdominal abscess, intestinal fistula, adhesion ileus and incision hernia in 6 months on average (range 1 ～ 18 months)after operation. Conclusion Laparoscopic appendectomy by concealed three-ports technique was a safe and available method and had advantages such as convenience and safety,good cosmetic results,less injury,rapid recovery,less complications,cheap and easy.

Objective: To explore the correlation between the expression of C-terminal tensin-like protein (CTEN) and the prognosis of hepatocellular carcinoma (HCC). Methods: Using immunohistochemistry, we detected CTEN protein level in samples of primary lesion and adjacent non-tumor lesion collected from 240 patients with HCC. The relationship between CTEN expression and clinicopathology, 5 year recurrent-free survival, or overall survival was evaluated by Chi-square test, Kaplan-Meier, or Cox regression analysis. Results: High CTEN expression was detected in 55% of hepatocellular carcinoma tissues and 20%of adjacent carcinoma tissues (P<0.001). CTEN expression was positively correlated with tumor diameter (P=0.022), venous invasion (P=0.007) or TNM stages (P=0.022). Five-year recurrence-free survival time (P<0.001) and overall survival time (P<0.001) in patients with high CTEN expression were signiifcantly less than those in patients with low CTEN expression. Multivariate Cox regression analysis revealed that the CTEN expression was an independent prognostic marker for HCC (all P<0.05). Conclusion: CTEN protein may play a role in the genesis and development of HCC, and it can function as a prognostic marker.

Objective To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) combined with type Ⅱ collagen-hyaluronic acid-oxidized chondroitin sulfate (Col Ⅱ-HA-OCS) biomimetic hydrogel to repair articular cartilage defect in porcine and the role of the transplanted cells played in the process of cartilage repair.Methods A articular cartilage defect model which remaining cartilage calcified zone was created in the knee of Bama minipigs,the autologous BMSCs was used as seeds for transplantation and was labeled by the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE).Animals were randomly divided into three groups:Group A (blank group) was left untreated,group B (cell-free biomimetic hydrogel group) was filled with biomimetic hydrogel and group C (BMSCs combined with biomimetic hydrogel group) was filled with the CFDA SE labeled autologous BMSCs combined with biomimetic hydrogel.One month after the operation,BrdU labeled liquid was injected intravenously into the animals 24 h and 48 h before specimens were taken from the executed animals.Partial cartilage repaired tissue in Group C was taken,cryosectioned and stained with DAPI and BrdU immunofluorescence.Confocal laser scanning microscope was used to observe and count the cells.Specimens of the three groups were analyzed through gross observation and histological staining,and scored according to the international cartilage repair society (ICRS) gross morphological score and ICRS histological score.Results Laser scanning confocal microscopy showed (97.3 ± 2.6) ％ of the cells were derived from the implanted BMSCs in repaired tissue and that the ratio of these cells with proliferative capacity was (76.6 ± 2.5) ％.Gross observation suggested most of the cartilage defect areas in Group C were filled with ivory tissue,but those in Group A and B were still obvious depression.Histological staining showed the cartilage defect areas in Group C were filled with cartilage like tissue,which was well integrated with the surrounding normal cartilage,presented a few cartilage lacunas could be seen,and had contents of Col Ⅱ and glycosaminoglycan similar with the adjacent normal cartilage.There was almost no filler in the defect area in Group A.There was little fibrous tissue in the defect area in Group B.ICRS gross score was (8.3 ± 1.0) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(2.3 ± 0.5) points] (P ＜ 0.05).ICRS histological score was (10.3 ± 2.4) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(4.5 ± 1.0) points] (P ＜ 0.05).Conclusions BMSCs combined with Col Ⅱ-HA-OCS biomimetic hydrogel for repairing porcine articular cartilage defects can achieve satisfactory results.Implanted BMSCs are the main component of the cell composition in the repaired tissue and gradually differentiated into chondrocytes.