Objective To analyse the variability of spontaneous firing frequencies and firing patterns of a Hippocampal CA1 neuron with the changes of extracellular potassium concentration[K+]0 and ion channel conductance.Methods A 16-compartment cable model of a Hippocampal CA1 neuron was developed based on the Warman model with computer software MATLAB.The dendrites contained no active channels,while five active channels (INa,INap,IDR,IA,IM)were contained in soma.In the model,the calcium currents and potassium currents(ICm,,ICT and IAHP) regulated by calcium concentration were not included.ResultsSimulation results showed that the neuron could generate periodicspontaneous firing activity.The spiking frequency increased with the increasing of[K+]0 and sodium conductance and decreasing of potassium conductance.Spontaneous single neuron activity appeared in singlet or in grouped bursts of two or three spikes.Conclusion The variability of spontaneous firing frequencies and firing patterns of single neuron are relevant to[K+]0 and ion channel conductance.

Objective:To evaluate the effect and adverse reaction of thymosin ?1(T?1) in the treatment of malignant tumor.Methods:MEDLINE,Chinese hospital knowledge database(CHKD),Chinese Biomedical Database(CBM) were searched by key word ,and the obtained references were screened for clinical controlled trials(CCT) on the introduction of T?1 in therapy of malignant tumor.The CCT results of efficacy and safety were pooled and analyzed with a fixed or random effects model after Chi-Square testing for heterogeneity.Results:Six CCTs were included for efficacy analysis.It was found that the efficacy rate in T?1 group(70.63%) was significantly higher than that in control group(52.99%),and the value of odds ratio was 1.28 with the 95% confidence interval from 1.06 to 1.55(P

Objective To evaluate endoscopic ultrasonography (EUS) in preoperative staging of gastric carcinoma,and to study the molecular biologic basis of its ultrasonic manifestation.Methods Sev-enty-four patients with gastric carcinoma were referred to EUS and staged preoperatively.The staging esults of EUS were compared with the histopathological staging and the expression of PTEN.Results The verall accuracy rate of EUS for determination of T staging was 82.4%(61/74),for T1,T2,T3 and T4 were 100.0%,72.7％,85.O％ and 78.9％,respectively.For N staging,EUS had the overall accuracy rate of 74.3%(55/74),with sensitivity and specificity of 80.8％ and 59.1％,respectively.The preoperative EUS for T and N staging of gastric carcinoma was of inverse correlation with the expression of PTEN.Conclusions EUS is an accurate staging modality in determining carcinoma invasive depth and lymph node involved,with a few exceptions of overstaging and understaging.However,EUS criteria to differentiate benign from malignant nodes still need to be further defined by future studies.The preoperative EUS for T and N staging could well display the molecular pathologic basis of gastric carcinoma.

BACKGROUND:Currently,there are three types of visual prosthesis:retinal prosthesis,optic nerve prosthesis and visual cortical prosthesis.Normal optic nerve fiber is the basis to apply visual prosthesis.Extracellular stimulation of myelinated optic nerve fiber is developed from intracellular stimulation,with feasible selection of stimulation locations and low requirements for operation.OBJECTIVE: Using computer to simulate the response of myelinated rat optic nerve fiber to extracellular point current source and to analyze the effect of the position of the point source on the response of the optic nerve fiber.METHODS:The experiment data of ion channels of rat optic nerve fiber and the characteristic of common ion channels were summarized,and the existing Hodgkin-Huxley like optic nerve fiber models were analyzed.The response of the optic nerve fiber model was simulated by computer,and the differences of action potentials of Ranvier node were compared by changing the position of point source.RESULTS AND CONCLUSION:Simulated models showed that the response of optic nerve is affected by the position of extracellular exciting electrode.The myelinated rat optic nerve fiber is easier to activate when the distance between point source and the Ranvier node center of the optic nerve fiber is short.

Objective To analyze the prevalence of hypertension in coal mine male workers and its influencing factors. Methods A total of 1 772 coal mine male workers from a coal mining group were selected as research subjects using multi stage complex sampling method. The prevalence of hypertension and its influencing factors were analyzed. Results The prevalence of hypertension was 33.0%（585/1 772）. Logistic regression analysis of complex sampling showed that body mass index， family history of hypertension， alcohol-drinking， tea-drinking， and snoring were independent risk factors for hypertension（all P<0.05），after adjusting for the effects of other inclusion factors on the basis of age. The risk of hypertension in coal mine male workers was higher in those with overweight and obesity than in normal weight（all P<0.01），higher in those with family history of hypertension than in no history of hypertension（P<0.01），and higher in tea drinkers than in no tea drinkers （P<0.05）. The more the alcohol consumption and the higher the frequency of snoring，the higher the risk of hypertension（all P<0.01）. These factors have a dose-response relationship. Conclusion The body mass index，family history of hypertension，alcohol-drinking，tea-drinking and snoring can affect the prevalence of hypertension in coal mine male workers.

Objective To investigate the hemodynamic changes in cirrhosis rats after orthotopic liver transplantation. Methods The cirrhosis model was constructed in 50 healthy male SD rats by intraperitoneal and subcutaneous injection with carbon tetrachloride (CCl_4), and induced by drinking alcohol solution for 10 weeks. Orthotopic liver transplantation with two-cuff technique was adopted to these rats. The hemodynamic changes were observed. Results Cirrhosis model was constructed in 36 rats, 26 of which then received liver transplantation. Finally 12 cirrhosis rats survived, and hemodynamics of portal vein were observed. The statistical analysis revealed that the portal venous pressure decreased significantly after the operation compared with pretransplant [(1.60±0.10)kPa vs. (1.70±0.25)kPa, P<0.05]; the portal vascular resistance increased significantly [(7.55±1.02)mL/min vs. (6.15±0.88)mL/min, P<0.05]; however, the portal venous flow decreased obviously[(11.84×10~(-2)±2.51×10~(-2))kPa/(mL·min)vs.(16.29×10~(-2)±2.40×10~(-2))kPa/(mL·min),P<0.05-.Conclusion The hemodynamics of cirrhosis rats ameliorate after rthotopic liver transplantation.

Objective To observe the effect of midazolam plus propofol administered for colonoscopy on cognitive function in middle-aged and aged patients. Methods One hundred and thirty six patients, ASA I and II, aged 40~75 years and undergoing colonoscopy were randomized to propofol group (group P, n=68) and propofol plus midazolam group (group PM, n=68). Baseline cognitive function was measured using Mini mental state exami-nation (MMSE) before anesthesia and the cognitive testing was repeated 10 minutes after emerging from anesthesia. BP, HR, SpO2, analgesic effect and sedative drug doses in both groups were recorded. Procedure time, recovery time and Rasmay sedation score were both recorded. Results Recovery time was significantly longer in group PM than that in group P (P<0.05). The total dose of propofol was significantly smaller in group PM than that in group P (P<0.05). MMSE score of both groups decreased, but the incidence of cognitive decline and the level of cognition in group PM were more notable than those of group P (P<0.05). Conclusions Midazolam plus propofol and propo-fol alone administered for colonoscopy could both increase the incidence of cognitive decline, and the effect of the former is more notable, but midazolam added to propofol could reduce the dosage of propofol.

Cough ; diagnosis ; Disease Management ; Humans

AIM:To explore whether histamine can regulate the expression of early growth response factor-1 (Egr-1) in the cerebral cortex astrocytes.METHODS:Normal wild-type (WT) mice, histidine decarboxylase knockout ( HDC-KO) mice and histamine treated HDC-KO mice were sacrificed for extracting the total RNA of the cerebral cortex. Primary cultured rat cortical astrocytes were treated with histamine at concentrations of 10 -8 , 10 -7 , 10 -6 , 10 -5 or 10 -4 mol/L for 15, 30, 60, 120 or 240 min.H1 or H2 receptor antagonists were pretreated for 15 min before histamine treat-ment.After histamine treatment, the cell total RNA or protein was extracted.The expression of Egr-1 at mRNA and protein levels was determined by real-time PCR and Western blot.RESULTS:The mRNA level of Egr-1 in cerebral cortex of HDC-KO mice was significantly lower than that in WT mice, while exogenous histamine induced the mRNA expression of Egr-1 in HDC-KO mice.In cultured astrocytes, histamine induced the mRNA expression of Egr-1.The maximum increase in the mRNA level of Egr-1 was produced by histamine at concentration of 10 -5 mol/L.In addition, histamine-induced Egr-1 mRNA accumulation peaked at 30 min after commencing stimulation, while histamine significantly increased Egr-1 protein expression at 60 min.Furthermore, histamine-induced Egr-1 expression was inhibited by H1 receptor antagonist but not H2 receptor antagonist.CONCLUSION:Histamine up-regulates the Egr-1 expression in cerebral cortex and cultured astrocytes, which may attribute to H1 receptor activation.