ABSTRACT
Objective To investigate the effect of different extinction training on fear memory,DNA methylation protein and hippocampal newborn neurons in adult rats.Methods Male SD rats were randomly divided into four groups:naive group,conditioned fear group,traditional-extinction group and retrieval-extinction group.Conditioned fear models were established by tone paired foot shock,and retrieval-extinction training or traditional-extinction training were performed in adult rats.Retention test,Western blot and immunnohischemistry were used to detect the no-freezing time percentage,the DNA methylation protein level,the newborn neurons respectively at 1d,4d and 7d after different extinction training.Results The traditional-extinction group((28.06± 11.33) ％) or retrieval-extinction group((30.28± 11.48) ％) had higher percentage of no-freezing time than that of conditioned fear group((21.35±9.45) ％),and lower percentage of no-freezing time than that of naive group ((75.65±8.69)％) (t=2.204,2.517,7.955,7.023,all P＜0.05) at the fourth day after extinction training.At the seventh day after extinotion training,the retrieval-extinction group ((69.72±13.62)％) had higher percentage of no-freezing time than traditional-extinction group((24.27± 11.67)％,t=7.052,P＜0.01) or conditioned fear group((50.64± 12.51)％,t=2.451,P＜0.05),and showed no significant difference compared with naive group((72.03±9.36) ％,t=0.251,P＞0.05).The expressions of Dnmt-1 and MBD-2 in traditional-extinction group or retrieval-extinction group were lower than those in conditioned fear group,and higher than those in naive group (P＜0.05) at 4 d after extinction.training.At 7 d after extinction training,the expressions of Dnmt-1 and MBD-2 in retrieval-extinction group were lower than those in traditional-extinction group or conditioned fear group (P＜0.05),and there was no significant difference between retrieval-extinction group and naive group.The Brdu-positive cells of traditional-extinction group or retrieval-extinction training were higher than conditioned fear group,and less than naive group (P＜0.05) at the fourth day after extinction training.At the seventh day after extinction training,the Brdu-positive cells in retrieval-extinction group were higher than those in traditional-extinction group or conditioned fear group (P＜0.05),and there was no significant difference between retrieval-extinction group and naive group.Conclusion The extinction training can decrease fear memory of rats with conditioned fear memory,and the effect of retrieval-extinction training were better than traditional-extinction training,which may be associated with the increases of hippocampus newborn neurons and the decline of DNA methylation.
ABSTRACT
Objective:To investigate the current status and related factors of psychological distress in tele-phone operators.Methods:Totally 575 telephone operators from sample of a convenient survey in a certain telecom-munication company of Shandong Province were selected.They were assessed with Kessler Psychological Distress Scale (K10),Connor-Davidson Resilience Scale (CD-RISC-10),Perceived Social Support Scale (PSSS)and Sim-plified Coping Style Questionnaire (SCSQ)for the evaluation of psychological distress,resilience,perceived social support and the coping style respectively.Ordinal logistic regression was used to identify the related factors of psy-chological distress.Results:The mean score of K10 was (24.7 ±6.7),91.8% (528 /575)of telephone operators had psychological distress.Specifically,24.5%(141 /575)had mild psychological distress,45.4% (261 /575)had moderate psychological distress,21.9% (126 /575)had severe psychological distress.Ordinal logistic regression a-nalysis indicated that the ones with good economic conditions (OR =1.74,95%CI:1.15 -2.63),higher level of re-silience (OR =1.13,95%CI:1.10 -1.17)and other social support (OR =1.07,95%CI:1.02 -1.12)had milder psychological distress;while with negative coping style (OR =0.29,95%CI:0.20 -0.41)had more severe psycho-logical distress.Conclusion:It suggested that the prevalence rate of psychological distress among telephone opera-tors is high.Poor economic conditions,lower level of resilience and social support,and negative coping style might be the related factors of psychological distress.
ABSTRACT
Objective To explor the value of Tei index for evaluation the cardiac function of patients with chronic heart failure(CHF).Methods Tei index in 60 patients with CHF(CHF group) and 30 normal controls(control group) were evaluated and compared with the levels of NT-ProBNP and the NYHA class,and the sensitivity and specificity of Tei index for CHF diagnosis were appraised.Results (1) Tei index in CHF group was significantly higher than that in control group.When Tei index was more than and equal to 0.45,the sensitivity,specificity,positive predictive value,and negative predictive value of Tei index for diagnosing CHF were 85.6％,90.4％,89.8％ and 78.0％.(2)There was a remarkable positive correlation between Tei and Log NT-ProBNP(r =0.84,P ＜ 0.01).(3)There were significant differences in Tei index among NYHA Ⅱ,Ⅲ,Ⅳ class [(0.47 ± 0.06),(0.56 ± 0.08),(0.64 ±0.13)].Conclusion Tei index can be used to diagnose CHF and evaluate the degree of it.
ABSTRACT
Objective The experiment aims at probing the best condition of the isolation and purification of rat islets.Methods The islets were isolated from rat pancreas by hepatopancreatic duct perfusing with collagenase and purified with Ficoll 400 discontinuous density gradient centrifugation.Then the purified islets were subjected to histological staining,electron microscopy and radioimmunoassay for identification of specificity and viability.Results The histological staining revealed that the viability and the purity of the purified islets were above 95％and 85％respectively.Electron microscopy showed that the purified islets were morphologically intact with clear membrane and plenty of secreting granules.Radioimmunoassay demonstrated the secreted insulin concerntration between low-glucose groups and high-glucose groups varied significantly,which verified the good function of the islets.Conclusion Hepatopancreatic duct perfusing with collagenase is a good method for digestion.There aye many factors that influence the quantity and quality of the acquired islets,such as the completed expansion of pancreas,the concentration and viability of collagenase and the digested time,etc.
ABSTRACT
Objective The experiment aims at probing the best condition of the isolation and purification of rat islets. Methods The islets were isolated from rat pancreas by hepatopancreatic duct perfusing with collagenase and purified with Ficoll 400 discontinuous density gradient centrifugation.Then the purified islets were subjected to histological staining,electron microscopy and radioimmunoassay for identification of specificity and viability. Results The histological staining revealed that the viability and the purity of the purified islets were above 95% and 85% respectively.Electron microscopy showed that the purified islets were morphologically intact with clear membrane and plenty of secreting granules.Radioimmunoassay demonstrated the secreted insulin concerntration between low-glucose groups and high-glucose groups varied significantly,which verified the good function of the islets.Conclusion Hepatopancreatic duct perfusing with collagenase is a good method for digestion.There are many factors that influence the quantity and quality of the acquired islets,such as the completed expansion of pancreas,the concentration and viability of collagenase and the digested time,etc.