Effect of C5-siRNA silencing receptor C5 on myocardial ischemia injury in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of C5-siRNA on pathological changes after myocardial ischemia in rats.</p><p><b>METHODS</b>Thirty healthy Sprague-Dawley rats were randomly divided into sham-operated group, ischemia group and C5-siRNA group. The cardiac ischemia models were established in ischemia group and C5-siRNA group by ligating the proximal end of the left anterior descending (LAD) coronary artery. The rats were infused with 100 microl/kg of C5-siRNA into myocardial tissue in C5-siRNA group and equal amount of normal saline in ischemia group and sham-operated group after ligating the LAD coronary artery for 30 min and then performed of ischemia for 4 hours. The cardiac index and left ventricular mass index were determined, morphological changes of myocardial tissue observed under optical microscope and the expression of C5 was detected by immunohistochemical staining and image analysis system.</p><p><b>RESULTS</b>There were no statistically significant difference between the three groups in the left ventricular mass index and cardiac index in the rats after ischemia for 4 hours. Light microscopy indicated edema and degeneration of the myocardial tissue were milder in C5-siRNA group than in ischemia group, a small amount of red blood cells existed in the myocardial stroma of the former. The expression of C5 was increased more significantly in ischemia group and C5-siRNA group than in sham-operated group (P<0.001), but was decreased in C5-siRNA group more than in ischemia group with no statistically significant difference between the two groups (P=0.132).</p><p><b>CONCLUSION</b>C5-siRNA could attenuate myocardial ischemia injury in rats by reducing inflammatory cell infiltration and expression of C5.</p>

Efficacy of endoscopic variceal ligation and its correlation with liver function / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To analyze the efficacy of endoscopic variceal ligation and its correlation with liver function.</p><p><b>METHODS</b>322 patients received EVL (endoscopic variceal ligation) and 34 patients with PDP (pericardial devascularization procedure) were retrospectively analyzed and divided into groups A, B and C. These patients were then subdivided into bleeding and non-bleeding subgroups according to Child-Pugh scores of liver function and history of upper gastrointestinal bleeding. The bleeding rate and mortality were contrasted between EVL and PDP. Liver function, Platelet count, leucocyte count and spleen thickness of before and after ligation were contrasted in EVL.</p><p><b>RESULTS</b>The bleeding rate and mortality were 1.7%, 3.4%, 7.0%; 0%, 5.1%, 8.1% in EVL group and 9.1%, 14.3%, 100.0%; 0%, 9.5%, 50.0% in PDP group, respectively. Variceal obliteration needed means of 2.1+/-0.7, 3.1+/-0.8 and 4.2+/-1.2 sessions in A, B and C ligation groups, respectively (F = 41.2, P is less than 0.01). On subgroup analysis, the numbers of ligation session were 2.6+/-0.7, 3.2+/-0.9 and 4.3+/-1.1 in A, B and C bleeding subgroup (F = 39.3, P value is less than 0.01) and 2.0+/-0.6, 2.7+/-0.6, and 2.9+/-0.4 in A, B and C non-bleeding subgroup, respectively (F = 17.0, P value is less than 0.01). ALT, AST, Platelet count and leucocyte count reduced significantly, spleen thickness increased remarkably in bleeding subgroup after ligation.</p><p><b>CONCLUSION</b>The efficacy of EVL was significantly negatively correlated with liver function and prior to pericardial devascularization procedure. EVL had no effect on liver function but might increase spleen thickness and aggravate hypersplenism. EVL was recommended especially for the bleeding liver cirrhosis patients with Child B and C scores.</p>

Transient change of cardiac action potential and intracellular Ca2+ during ventricular fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>The cardiac action potential (AP) and the intracellular Ca(2+) transient (CaT) are closely associated under normal physiological conditions, but not during ventricular fibrillation (VF). The purpose of this study was to determine whether this dissociation is directly related to the higher activation rate during VF.</p><p><b>METHODS</b>We optically mapped AP and CaT simultaneously in nine isolated rabbit hearts. Pinacidil, a K(ATP) channel opener, was used to shorten the action potential duration (APD) in order to capture tissue at fast pacing rates or to induce ventricular tachycardia (VT) comparable to VF activation rates. Mutual information (MI) was used to calculate the degree of AP and CaT coupling.</p><p><b>RESULTS</b>Pinacidil (40 micromol/L) infusion significantly shortened APD. The averaged cycle length (CL) of VF without Pinacidil was (77 +/- 13) ms, whereas the shortest CL achieved during VT under Pinacidil infusion was 76 ms. MIs during fast pacing (1.13 +/- 0.15) bits and fast VT (0.88 +/- 0.18) bits were higher than those during baseline VF (0.39 +/- 0.11) bits, VF with Pinacidil infusion (0.21 +/- 0.07) bits and VF after Pinacidil washout (0.36 +/- 0.15) bits. MIs during fast pacing or fast VT were higher than those of VFs at comparable dominant frequencies.</p><p><b>CONCLUSIONS</b>CaT is closely associated with the AP during fast pacing and fast VT, but not during VF. The reduced MI during VF is not secondary to the fast rate of ventricular activation.</p>

Ectopic expression of keratin 19 and integrin beta1 during wound healing process after microskin grafting in rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the characteristics of keratin 19 and integrin beta1 expressions in the wound after microskin grafting , and to investigate the healing mechanism.</p><p><b>METHODS</b>Full layer skin defects were created in twenty Sprague-Dawley rats and they were divided into two groups, i.e., A group (with grafting of autologous microskin accounting 10% in weight of epidermis loss from skin defect), B group (with grafting of autologous microskin and allogeneic microskin, accounting 10% and 40% weight of epidermis loss respectively in skin defect). The wound healing rate and contraction rate were observed at 2,3,4 post-grafting week (PGW), and the expression and distribution of keratin 19 and integrin beta1 were observed at 2 and 4 PGW.</p><p><b>RESULTS</b>The wound healing rate in the B group on 2 and 3 PGW was obviously higher than that in A group [(85 +/- 5)% vs. (53 +/- 10)%, (84 +/- 8)% vs. (65 +/- 9)%, P < 0.01]. No obvious difference in wound contraction rate between the two groups was observed on the 2, 3 and 4 PGW (P > 0.05). Cells with expression of keratin 19 and integrin beta1 were observed in the suprabasal layers of the epidermis in healing wound, but not in the basal membrane. Integrin beta1 positive expression cells were not observed in the suprabasal layers until 4 PGW.</p><p><b>CONCLUSION</b>Mixed grafting with autogenous and allogenous microskin can improve wound healing. Ectopic expression of keratin 19 and integrin beta1 exists during wound healing process after microskin grafting.</p>

Inhibition of integrin beta1 expression in human keratinocyte stem cells by vector-1 based interfering RNA strategy / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of integrin beta1 on the proliferation and differentiation of human keratinocyte stem cells (KSCs).</p><p><b>METHODS</b>DNA oligonucleotides targeting integrin beta1 at different locations were synthesized and inserted into BamHI-1 HindIII linearized p Silencer 3.1/H1 plasmids. The inserted sequences were verified by DNA sequencing. The KSCs were divided into control (without transfection), T1 (with transfection of vacant vector), T2 (with transfection of si integrin beta(1-1) vector), T3 (with transfection of si integrin beta(1-1) vector), and T4 (with transfection of si Negative vector) groups. The change in the expression of integrin beta1, was determined with Western blotting. The positive vector with the highest expression of integrin beta1 was selected and named as integrin beta1, and semi-quantitative RT-PCR was employed to detect the change in the expression of integrin beta1 mRNA.</p><p><b>RESULTS</b>The protein expression of integrin beta1, was not suppressed in control and T1 group, but it was suppressed in T2 and T3 groups, especially in T3 group (the suppression rate was 60%-70%, which was named si integrin beta1). The expression of integrin beta1 mRNA was obviously decreased by integrin beta1, transfection (the suppression rate was 70%).</p><p><b>CONCLUSION</b>The expression of integrin beta1, mRNA and protein could be down-regulated with recombinant si integrin P, vector transfection.</p>

Clinical analysis of the changes of plasma BNP,Mb and TnⅠin patients with acute myocardial infrction / 中国基层医药

Objective To investigate the dynamic changes of plasma myoglobin(Mb),troponinⅠ(TnⅠ) and brain natriuretic peptide(BNP)levels in the course of acute myocardial infrction(AMI)and to detect the best marker for early diagnosis and outcome prediction.Methods Plasma Mb,TnⅠand BNP levels were measured in 49 patients with AMI both before and after thrombolysis therapy and 32 controls.Results Plasma levels of all the three markers were significantly higher in the AMI patients than those in the controls(P

Noncontact endocardial mapping to guide ablation for hemodynamically unstable or nonsustained ventricular tachycardia / 中华心血管病杂志

<p><b>OBJECTIVE</b>To determine the feasibility and assess the validity of noncontact endocardial mapping to guide ablation of hemodynamically unstable or nonsustained ventricular tachycardia (VT).</p><p><b>METHODS</b>Noncontact mapping permitted individual-beat analysis of ventricular arrhythmias. Three-dimensional electroanatomical mapping allowed detailed reconstruction of a chamber geometry and activation sequence. Eighteen hemodynamically unstable or nonsustained VTs were induced (cycle length: 336 ms +/- 58 ms) in 17 patients and mapped by noncontact mapping using an EnSite 3000 system performed for the guidance of catheter ablation.</p><p><b>RESULTS</b>Three patients were mapped during premature ventricular complexes (PVCs) because sustained VT could not be induced. Analysis of the archived noncontact activation maps was performed to identify the exit site and/or the diastolic pathway of the VT reentry circuit. The endocardial exit sites 10 ms +/- 16 ms before QRS were defined in 9 right ventricular outflow tract (RVOT) and 5 ischemic VTs. The diastolic pathway was identified in 5 ischemic VTs. The earliest endocardial diastolic activity preceded the QRS onset by 60.1 ms +/- 42.6 ms. The earliest activation sites were identify in 3 patients with nonsustained VTs or PVCs. Radiofrequency current was applied around the exit site or to create a line of block across the diastolic pathway. Catheter ablation was performed in 17/18 (94%) VTs and 15/17 (88%) VTs was successfully ablated. Two (67%) of the three patients with non-sustained VTs were mapped and successfully ablated during PVCs. Catheter ablation was not performed in 1 patient (peri-Hisian VT) and was unsuccessful in 2 patients.</p><p><b>CONCLUSION</b>Noncontact endocardial mapping is able to be used to guide ablation of untolerated or nonsustained VTs.</p>

Influence of mixed grafting of autologous and allogeneic microskin on burn wound healing in rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the influence of mixed grafting of autologous and allogeneic microskin on burn wound healing.</p><p><b>METHODS</b>Autologous microskin grafting (expansion rate 5:1) was employed as control. Autologous microskin mixed with the allogeneic microskin with the thickness of 0.3 mm and 0.6 mm, respectively, were designated as experimental groups 1 and 2 (EP1 and EP2). The wound healing rate, wound contraction rate, and histological changes were observed on the 2nd, 3rd and 4th weeks after the grafting.</p><p><b>RESULTS</b>The wound healing rate in two experimental groups (94.58 +/- 3.99)% in EP1, and (95.28 +/- 1.93)% in EP2 was significantly higher than that in the control group (88.28 +/- 6.85)% at the end of the 2nd week after the grafting (P < 0.05) The wound healing rate in experimental group 2 (94.55 +/- 3.47)% was obviously higher than that in control (88.51 +/- 5.59)% and experimental group 1 (89.51 +/- 4.70)% at the end of the 3rd week after grafting (P < 0.05). There was no obvious difference in wound healing rate among the three groups at the end of the 4th week after grafting. Obvious lymphocytic infiltration was observed by histological examination between epidermis and dermis in the two experimental groups at the end of the 2nd week after grafting. But there was no obvious difference among the three groups 4 weeks after grafting.</p><p><b>CONCLUSION</b>The wound healing could be improved by mixed skin grafting with appropriate quantity of allogeneic and autologous microskin. Furthermore, the wound contraction could be ameliorated if the thickness of allogeneic dermis was increased in the mixed grafting even with the same proportion of allogeneic to autologous microskin.</p>