Immunological balance of CD8CD28/CD8CD28T lymphocytes can predict gastrointestinal hemorrhage in patients with inflammatory bowel disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the sensitivity and specificity of CD8CD28/CD8CD28T lymphocyte balance in predicting the gastrointestinal hemorrhage (GH) in patients with inflammatory bowel disease (IBD).</p><p><b>METHODS</b>Forty-nine IBD patients, including 30 with ulcerous colitis (UC) and 19 with Crohn's disease (CD), were enrolled to test peripheral blood CD8CD28and CD8CD28T cells using flow cytometry. All the patients were followed up for one year. The receiver-operating characteristic (ROC) curves were used to test the efficiency of CD8CD28/CD8CD28T lymphocyte balance to predict GH. The differences in lasting time of remission (LTR) under different factors were compared using Kaplan-Meier survival analysis, and the correlation between CD8T lymphocytes and the factors were analyzed.</p><p><b>RESULTS</b>The utilization rates of immunosuppressant, steroids, and biological agent (BA) were significantly higher in CD patients than in UC patients (P=0.003, 0.043 and 0.002, respectively). The frequencies of CD8CD28T cells were obviously higher in UC patients than those in CD patients (t=3.022, P=0.004). CD8CD28T cells, CD8CD28T cells, and especially CD8CD28/CD8CD28ratio (area under curve of 0.977, P=0.000; cut-off value of 1.14 [13.95%/12.24%] with a sensitivity of 93.3% and a specificity of 91.2%) showed good efficiencies in predicting GH (P<0.01). The mean and median of LTR of IBD patients who did not receive BA or surgical treatment were significantly longer (Χ=9.730, P=0.002; Χ=15.981, P=0.000). CD8CD28/CD8CD28ratio was significantly related to both BA (P=0.009) and surgery (P=0.038).</p><p><b>CONCLUSION</b>Both decreased CD8CD28T cells and elevated CD8CD28T cells are closely correlated with GH, and their ratio can predict the occurrence of GH with a high sensitivity and specificity and is correlated with BA and surgery at the cut-off value of 1.14.</p>

Effects of chronic multiple stress on learning and memory and the expression of Fyn, BDNF, TrkB in the hippocampus of rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The effect of chronic stress on cognitive functions has been one of the hot topics in neuroscience. But there has been much controversy over its mechanism. The aim of this study was to investigate the effects of chronic multiple stress on spatial learning and memory as well as the expression of Fyn, BDNF and TrkB in the hippocampus of rats.</p><p><b>METHODS</b>Adult rats were randomly divided into control and chronic multiple stressed groups. Rats in the multiple stressed group were irregularly and alternatively exposed to situations of vertical revolution, sleep expropriation and restraint lasting for 6 weeks, 6 hours per day with night illumination for 6 weeks. Before and after the period of chronic multiple stresses, the performance of spatial learning and memory of all rats was measured using the Morris Water Maze (MWM). The expression of Fyn, BDNF and TrkB proteins in the hippocampus was assayed by Western blotting and immunohistochemical methods. The levels of Fyn and TrkB mRNAs in the hippocampus of rats were detected by RT-PCR technique.</p><p><b>RESULTS</b>The escape latency in the control group and the stressed group were 15.63 and 8.27 seconds respectively. The performance of spatial learning and memory of rats was increased in chronic multiple stressed group (P < 0.05). The levels of Fyn, BDNF and TrkB proteins in the stressed group were higher than those of the control group (P < 0.05). The results of immunoreactivity showed that Fyn was present in the CA3 region of the hippocampus and BDNF positive particles were distributed in the nuclei of CA1 and CA3 pyramidal cells as well as DG granular cells. Quantitative analysis indicated that level of Fyn mRNA was also upregulated in the hippocampus of the stressed group (P < 0.05).</p><p><b>CONCLUSIONS</b>Chronic multiple stress can enhance spatial learning and memory function of rats. The expression of Fyn, BDNF and TrkB proteins and the level of Fyn mRNA are increased in the stessed rat hippocampus. These suggest that Fyn and BDNF/TrkB signal transduction pathways may participate in the process of the enhanced learning and memory during chronic multiple stress.</p>

Chronic multiple stress enhances learning and memory capability in rats / 生理学报

The present study aimed at investigating the effects of chronic multiple stress on learning and memory functions of rats. Adult male Wistar rats were randomly divided into stressed and control groups. Rats in the stressed group were irregularly and alternately exposed to the situation of vertical revolution, sleep deprivation, noise stimulation, and night illumination 6 h per day for 6 weeks to prepare a chronic multiple stressed model. Learning and memory performance of rats was measured by using Morris water maze first and Y-maze afterwards. Neurons in the dentate gyrus(DG), CA3 and CA1 regions of the hippocampus were stained by using Cresyl violet method and counted. The results showed that: (1) After chronic multiple stress, compared with the control rats, the escape latency to the hidden platform in Morris water maze was significantly shortened in stressed rats. In stressed and control groups, the escape latency periods were (15.89+/-9.15) s and (27.30+/-12.51) s, respectively, indicating that spatial memory of the stressed rats was stronger than that of the control ones. In brightness-darkness discrimination learning in the Y- maze, the correct trials and correct percentage of entering safe arm was remarkably increased in the stressed rats, the correct rates of stressed and control groups were (79.01+/-1.23)% and (66.12+/-1.61)%, respectively, indicating that brightness-darkness discrimination learning ability of the stressed rats was better than that of the control ones. (2) After chronic multiple stress, nerve cell density in DG, CA1 and CA3 of the hippocampus in stressed rats was higher than that of the control group, the cell densities in DG, CA1 and CA3 of the stressed and the control group were (223.78+/-26.52), (112.07+/-14.23) and (105.55+/-18.12) as well as (199.13+/-15.36), (92.89+/-13.69), and (89.02+/-15.77) respectively. These results suggest that the chronic multiple stress may enhance the capability of spatial memory and brightness-darkness discrimination learning of rats. Possible reasons for the chronic multiple stress-induced learning and memory enhancement of rats were also discussed.