Relationship Between the Changes of Left Atrium, Pulmonary Vein Ostia and AF Recurrence After Radiofrequency Catheter Ablation by Enhanced Cardiac MRI Evaluation / 中国循环杂志

Objectives: To evaluate the changes of left atrial volume (LAV) and the maximum ostial cross-sectional area (CAS) of pulmonary vein (PV) in atrial fibrillation (AF) patients after circumferential pulmonary vein isolation radiofrequency catheter ablation (CPVA-RFCA) and to explore their relationship to AF recurrence by enhanced cardiac MRI evaluation. Methods: Our research included in 2 groups: Control group, n=20 healthy subjects and AF group, n=78 patients whom were classified into 2 subgroups as Paroxysmal AF subgroup, n=46 and Persistent AF subgroup, n=32; 66 patients received CPVA-RFCA and based on 6 months post-operative recurrence, they were divided into another set of 2 groups: AF recurrent subgroup, n=17 and Non-AF recurrent subgroup, n=49. Pre- and 6 months post-operative maximum ostial CSA of PV were measured by enhanced cardiac MRI, LAV were obtained by 3D reconstruction and the differences were compared between AF group and Control group, Paroxysmal AF subgroup and Persistent AF subgroup, AF recurrent subgroup and Non-AF recurrent subgroup; their relationships to AF recurrence were studied.Results: Compared with Control group, AF group had increased LAV and elevated ostial CSA of superior PV (SPV), both P<0.05. Compared with Paroxysmal AF subgroup, Persistent AF subgroup had increased LAV and elevated ostial CSA of SPV, both P<0.05. Compared with pre-operative condition, at 6 months after the operation, Non-AF recurrent subgroup showed reduced ostial CSAs in left SPV (LSPV), right SPV (RSPV), right inferior PV (RIPV) and decreased LAV, all P<0.05;while AF recurrent subgroup showed expanded RSPV and increased LAV,allP<0.05.Post-operative reductions of LAV and ostial CSA of SPV had close correlation; multivariate Logistic regression analysis indicated that LAV (HR=1.05, P<0.01)and ostial CSA of RSPV(HR=1.09,P=0.05)were related to AF recurrence after RFCA. Conclusions: CAPV-RFCA could reverse left atrial and PV remodeling in AF patients, LAV and ostial CSA of RSPV were related to post-operative AF recurrence.

Cloning and expression of Hgp44 from Porphyromonas gingivalis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To clone and express the gene of Hgp44 in adhesin domains of gingipains from Porphyromonas gingivalis (Pg) and to purify the protein.</p><p><b>METHODS</b>The genomic DNA of Pg was isolated from PgATCC33277. The Hgp44 gene fragment was amplified by polymerase chain reaction (PCR) and then inserted into the cloning vector pMD18-T and sequenced. The correct fragment was linked with a prokaryotic expression vector pET-22b to construct the recombinant expression plasmid pET22b-Hgp44. The pET22b-Hgp44 confirmed by enzyme digestion was transformed into competent Escherchia coli (Ec) BL21 (DE3) cells. Expression of fusion protein was induced by isopropyl-β-D-thiogalactoside (IPTG), and purified by immobilized metal-chelating affinity chromatography (IMAC) using a Ni(2+) matrix column. SDS-polyaerylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis were used to examine the fusion protein.</p><p><b>RESULTS</b>A 1 100 bp fragment was successfully amplified and verified by the agarose gel electrophoresis and sequencing. The generated recombinant expression vectors pET22b-Hgp44 were verified by enzyme digestion and agarose gel electrophoresis. The expression of fusion protein in Ec BL21 (DE3) cells was examined by SDS-PAGE and Western blotting analyses, and the data showed that the protein was 44 000 in size and expressed mostly in the form of inclusion body. The purification of fusion protein was achieved using Ni(2+) affinity chromatography. About 3.5 mg/L fusion protein was obtained.</p><p><b>CONCLUSIONS</b>Hgp44 was successfully expressed in the prokaryotic expression system and purified by IMAC using a Ni(2+) matrix column.</p>

Role of CTLA4-Ig and anti-CD40L monoclonal antibody in the immune rejection of pancreas transplantation in rats / 中华器官移植杂志

Objective To investigate the role of CTLA4-Ig and anti-CD40L monoclonal antibody in the acute rejection of pancreaticoduodenal transplantation model of rats.Methods Pancreaticoduo- denal transplantation model was established from the donor F344 rats to the Lewis recipients(diabetes models).The models were divided into 4 groups:groups A,B,C and D with 12 rats in each group. Two days after transplantation,recipients were injected intraperitoneally with saline,CTLA4-Ig(200?g),anti-CD40L monoclonal antibody(200?g),CTLA4-Ig(200?g)combined with anti-CD40L monoclonal antibody(200?g)respectively.On the day 1,4,7,10 after transplantation,the grafts were harvested for histopathological examination and RT-PCR to determine the levels of interleukin (IL)-2,interferon(IFN)-?,IL-4 and IL-10;The blood CD3~+,CD4~+and CD8~+ T cells were detected by flow cytometry.On the day 4 after transplantation,the CD4~+ CD25~+ T cells in the grafts were de- tected by flow cytometry.Results As compared with group A,the severity of the rejection of grafts in groups B,C and D were depressed;Down-regulation of IL-2 was observed in the groups B,C and D, and the levels in group D were lowest.Down-regulation of IFN-7 was detected in the groups B,C and D,but there was no significantly difference between groups D and B or groups D and C.Up-regulation of IL-4 was observed in the groups B and C,and the levels in group D were lower than in groups A,B and C.Up-regulation of IL-10 was observed in groups B and C,and there was significant difference between groups D and B or groups D and C.The CD3~+,CD4~+ and CD8~+ T cells in groups B,C and D were less,but more CID4~+ CD25~+ T ceils in transplanted pancreas were observed,more notably in group D than in group C.Conclusions Combined use of CTLA4-Ig and anti-CD40L monoclonal anti- body can remarkably diminish the severity of the rejection,which might be mediated by altering the balance in Th1/Th2 and increasing the number of CD4~+ CD25~+ regulatory T cells.Co-stimulation blockade with CTLA4-Ig and anti-CD40L monoclonal antibody induction seems to be an attractive strategy to control allograft rejection.