ABSTRACT
BACKGROUND:During the process of acute brain injury after stroke, matrix metaloproteinase can undermine the integrity of vascular basement membrane, promote the migration of neutrophils and inflammatory factors, and cause secondary brain injury. OBJECTIVE:To investigate the activation of matrix metaloproteinase 2/9 and the degradation rule of claudin in rat models of middle cerebral artery ischemia at different ischemic durations. METHODS:Thirty-nine male SD rats were randomly divided into three groups according to different ischemic durations (3, 5 and 7 hours) . Middle cerebral artery occlusion (stroke) model was established using modified suture method,i.e., separation of the external carotid artery, inserting the suture into the internal carotid artery through the external carotid artery, and eventualy reaching the middle cerebral artery. The ischemic duration in these three groups was respectively 3 , 5 and 7 hours. After 2 hours of reperfusion, Zea-Longa score and Ludmila Belayev score, brain infarct area, matrix metaloproteinase 2/9 activities and claudin 5 degradation were determined in each group. RESULTS AND CONCLUSION:With the extension of ischemic duration, brain infarct area gradualy increased, central nervous system damage gradualy aggravated, matrix metaloproteinase 2/9 activities gradualy increased, and claudin-5 expression gradualy decreased. There were significant differences between any two ischemic durations in terms of each of above-mentioned indices. The results indicate that after long duration of ischemia, the progressive damage of brain tissue can cause the gradual increase of activation of matrix metaloproteinase 2/9 and the gradual degradation of claudin 5.
ABSTRACT
Objective To investigate the expression and clinical significance of T-cell receptor (TCR) Ⅴβ subfamily in hepatitis B virus (HBV)-related acute-on-chronic liver failure (HBV-ACLF) patients.Methods Twenty-eight patients with HBV-ACLF (HBV-ACLF group) and 32 patients with chronic hepatitis B flare (CHB-F group),who were treated in The Second People's Hospital from Oct.2010 to Mar.2012,and 20 healthy controls (HC group) were included in the study.Reverse transcriptase-polymerase chain reaction was used to detect the levels of TCR Ⅴβ subfamily and enzymelinked immunosorbent assay was used to detect the levels of serum cytokines [interleukin (IL)-2,IL-4,IL-6,IL-10,interferon (IFN)-γ and tumor necrosis factor (TNF)-α)] in the three groups.The comparison among three groups was done by one-way analysis of variance and the comparison between two groups was done by LSD-t test or rank sum test.Results The three groups had similar gender and age distribution (all P＞0.05).The HBV-ACLF group had significant different profiles of total bilirubin,albumin,prothrombin activity,international normalized ratio and cholesterol tatol compared with the CHB-F group (all P＜0.05).For patients in the HBV-ACLF group,the serum IL-2,IL-4,and IL-10 levels were lower(all P=0.000),and the IL-6 and IFN γ levels were higher than those of the HC group (all P=0.000).The IL-4,IL-10,and TNF-α levels in the CHB-F group were also significantly lower than those of the HC group (all P=0.000).Compared with the CHB-F group,the HBV-ACLF group had significantly lower IL-2,IL-10,and TNF-α levels (P=0.003,0.002,0.004),and higher IL-6 and IFN-γ levels (P=0.015,0.006).By one-way analysis of variance,there were significantly differences of △Ct1,△Ct5,△Ct7,△Ct12,△Ct15,△Ct20,△Ct22,and △Ct23 among the three groups (H=20.368,14.368,19.500,31.532,19.985,19.116,41.752 and 20.649,all P＜0.05).Conclusion The expression levels of TCR Ⅴβ subfamily and cytokines are changed in HBV-ACLF patients.