OBJECTIVETo investigate the influence of persistent rapid atrial pacing on the levels of connexin 43 (Cx43) and type III collagen in pulmonary vein and atrium in a canine model.

METHODSSixteen mongrel dogs were divided into rapid atrial pacing (RAP) group (n = 8) and normal control group (n = 8) randomly. In the RAP group, atrial pacing was performed with a rate of 400 bpm for 10 weeks to establish atrial fibrillation model. The tissues of left superior pulmonary vein (LSPV), left atrial free wall (LAFW) and right atrial appendage (RAA) were collected from each dogs. The levels of Cx43 and type III collagen were measured in each tissue.

RESULTSTen weeks later, persistent atrial fibrillation was induced in all dogs in RAP group. The level of Cx43 in RAP group was higher than that in normal control group (LSPV: 3370.91 +/- 275.11 vs 1405.82 +/- 90.38, P < 0.05; LAFW: 2448.68 +/- 272.10 vs 1467.12 +/- 147.93, P < 0.05, RAA: 2331.96 +/- 199.61 vs 1288.27 +/- 216.22, P < 0.05). The level of Cx43 in LSPV was higher than that in LAFW and RAA in RAP group, whereas the difference between LAFW and RAA was not significant in RAP group. The quantities of type III collagen in RAP group were higher than those in normal control group (LSPV: 3301.97 +/- 309.70 vs 1404.56 +/- 178.02, P < 0.05; LAFW: 2477.86 +/- 190.43 vs 1479.20 +/- 187.17, P < 0.05; RAA: 2045.92 +/- 139.43 vs 1417.07 +/- 139.43, P < 0.05). The quantities of type III collagen in LSPV was higher than those in LAFW and RAA in RAP group.

CONCLUSIONSPersistent rapid atrial pacing could increase the levels of Cx43 and type III collagen in pulmonary vein and atrium in a canine model of atrial fibrillation. The levels of Cx43 and type III collagen in pulmonary vein were higher than those in atrium. This findings indicated that pulmonary vein may be a crucial regions in maintaining atrial fibrillation.

Animals ; Atrial Fibrillation ; metabolism ; physiopathology ; Cardiac Pacing, Artificial ; methods ; Collagen Type III ; blood ; Connexin 43 ; blood ; Disease Models, Animal ; Dogs ; Female ; Male ; Pulmonary Veins ; metabolism ; physiopathology

OBJECTIVETo study regulation of Ca(2+)-activated K(+) channels (KCa) of mesenteric artery smooth muscle cell (SMC) from 21 old patients with essential hypertension (EH) by endothelin-1 (ET-1) and prostagl E(1) (PGE(1)).

METHODSMesenteric artery branch from EH was digested by enzyme. Patch clamp technique was used to pull cell-attached and inside-out patches on mesenteric artery SMC from EH and the normotensive patients respectively. The signal channel open probability (Po), open dwell-time (To) and close dwell-time (Tc), open channel number per patch were recorded. After adding Ca(2+) (10(-8) approximately 10(-6) mol/L), ET-1(2 approximately 8 x 10(9) mol/L) and PGE(1) (10, 20, 40, 100, 200, 400 nmol/L) to cytoplasm respectively. The parameters above were observed again.

RESULTSCompared to that of normotensive patients, the activities of KCa channels of patients with EH was higher. After adding Ca(2+) to cytoplasm,the Po of KCa channels in normotensive patients increased significantly. But it was few changes in EH group. KCa channels has dual reaction to ET-1 in normotensive patients. We have found no statistics difference when ET-1 present on KCa channels of EH cases. Whereas PGE(1) can affect KCa channels current and channels kinetic significantly in side-out patches. The Po of KCa channels increased. The To protracted and the Tc curtailed in EH.

CONCLUSIONSThe activities of KCa channels of patients with EH increased significantly. but the sensitive to Ca(2+) decreased. ET-1 were few effect to KCa channels. The PGE(1) can activated KCa channels of patients with EH.

Aged ; Alprostadil ; pharmacology ; Cells, Cultured ; Endothelin-1 ; pharmacology ; Female ; Humans ; Hypertension ; metabolism ; physiopathology ; In Vitro Techniques ; Male ; Mesenteric Arteries ; cytology ; Middle Aged ; Muscle, Smooth ; metabolism ; physiopathology ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; drug effects ; metabolism

Catheter Ablation ; Child ; Heart Septal Defects, Atrial ; surgery ; Humans ; Imaging, Three-Dimensional ; Male ; Tachycardia, Supraventricular ; surgery ; Tomography, X-Ray Computed

OBJECTIVETo prepare a stable water-based magnetic fluid.

METHODSA water-based magnetic fluid was prepared by addition of polyvinylpyrrolidone (PVP) as the coating agent for the magnetic particles. After preparation of Fe3O4 by co-precipitation method, PVP was added for its coating, followed by ultrasonic agitation and purification.

RESULTSThe magnetic nanoparticles of homogeneously small size and water-based magnetic fluid were obtained, which had good dispersion in water with strong magnetism.

CONCLUSIONPVP can be used as a surfactant to stabilize the magnetic fluid.

Ferrous Compounds ; chemistry ; Magnetics ; Materials Testing ; Nanoparticles ; chemistry ; Povidone ; chemistry ; Surface Properties ; Surface-Active Agents ; chemical synthesis ; chemistry

Animals ; Asia ; epidemiology ; History, 20th Century ; Humans ; Influenza A Virus, H2N2 Subtype ; chemistry ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; history ; virology ; Mutation

Background Recurrent atrial tachyarrhythmia (ATa) after circumferential pulmonary vein ablation (CPVA) includes atrial tachycardia (AT) and atrial fribrillation (AF). However, whether there are some differences in clinical course and mechanisms between the recurrent AT and the recurrent AF remained unclear. This study was conducted to investigate the incidence, mechanism, clinical course of the recurrent AT and AF in patients under CPVA.Methods One hundred and thirty consecutive patients (M/F=95/35) with highly symptomatic and multiple antiarrhythmic drugs (AADs) refractory paroxysmal (n=91) or persistent (n=39) AF were included. The ablation protocol consisted solely of two continuous circular lesions around the ipsilateral pulmonary veins (PV) guided by CARTO system. The endpoint of CPVA is PV isolation. For patients with recurrent ATa within 2 months after the initial procedure, cardioversion with direct current was attempted if the ATa lasted for more than 24 hours. A repeat ablation procedure was performed only for patients with AADs refractory recurrent ATa and at least followed up for 2 months after the initial procedure.Results Within 2 months after the initial procedure, 52 patients (40.0%) had experienced episodes of symptomatic recurrent ATa. Among them, 23 patients (44.2%) with recurred AT alone (AT group), 14 patients (26.9%) with recurred AF alone (AF group), and 15 patients (28.8%) with recurred AT and AF (AT plus AF group). The delayed cure rate (65.2%) in AT group was significant higher than that in AF group (21.4%, P<0.05) and AF plus AT group (26.7%, P<0.05). A repeat ablation was performed in 21 patients, including 6 patients with recurrent AT alone, 8 patients with recurrent AF alone, and 7 patients with recurrent AF plus AT. The mean number of PV gaps was 1.2±0.4 in AT group, which was significantly lower than that in AF group (2.6±0.7, P<0.05) and AF plus AT group (2.0±0.6, P<0.05). Delayed cure rate and number of PV gaps between AF group and AF plus AT group were comparable (P>0.05).Conclusions Present study indicates that recurrent AT and AF after CPVA have the different clinical course and different electrophysiological findings during repeat procedure as follows: ⑴After CPVA, spontaneous resolution of recurrent ATa was mainly found in patients with recurrent AT alone (about two thirds patients). ⑵The type of recurrent ATa after CPVA is associated with the number of PV gaps.

AIMTo study the expressions of scavenger receptor class B type I(SR-BI) and peroxisome proliferator-activated receptor gamma (PPARgamma) in atherosclerotic mini swine and provide a new mechanism for investigating the pathogenesis of atherosclerosis.

METHODSChinese mini swine were fed by a normal control diet or a high fat/high cholesterol diet for 12 months after common carotid artery injury induced by balloon denudation. Plasma total cholesterol(TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were determined by commercially enzymatic methods every two months. The sections, which were taken from liver and abdominal aorta, were stained with hematoxylin eosin. The expressions of SR-BI and PPARgamma mRNA and protein in liver and aorta tissue were detected by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry respectively.

RESULTSAt the end of 12 months, plasma TC, HDL-C and TG in HFHC mini swine were increased. There were fatty liver and atherosclerotic plaque in mini swine live and aorta respectively. The expression of SR-BI was upregulated in HFHC mini swine liver and aorta tissue.

CONCLUSIONHFHC may induce atherosclerosis and the expression of SR-BI and PPARgamma. Upregulating SR-BI expression may inhibit atherosclerosis. Increasing SR-BI expression in liver and aorta may accelerate SR-BI-mediated reverse cholesterol transport and develop a new anti-atherogenic strategy.

Animals ; Arteriosclerosis ; pathology ; Atherosclerosis ; metabolism ; PPAR gamma ; metabolism ; Receptors, Scavenger ; metabolism ; Swine

OBJECTIVETo compare the advantages and disadvantages of unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion in treating single segmental lower lumbar vertebra diseases.

METHODSSixty-two patients with single segmental lower lumbar vertebra disease who received treatment between January 2008 and June 2009. These patients were consisted of 16 males and 46 females, ranging in age from 27 to 72 years old, with a mean age of 51.6 years old. Among these patients, lumbar degenerative disease had in 22 patients, recurrence of lumbar intervertebral disc protrusion in 13 patients, lumbar intervertebral disc protrusion accompany with spinal canal stenosis in 12 patients, massive lumbar intervertebral disc protrusion in 5 patients and lumbar degenerative spondylolisthesis with degree I in 10 patients. The lesions occurred at L3,4 segment in 5 patients, at L4,5 segment in 42 patients, and at L5S1 segment in 15 patients. Thirty patients underwent unilateral pedicle screw fixation (unilateral screw fixation group, group A) and thirty-two patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation (bilateral screw fixation group, group B). Lumbar interbody fusion with intervertebral cages was also performed in all patients. Incision length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Loosening or breakage of internal fixations, displacement of intervertebral cages and interbody fusion conditions were observed in each group. Preoperative and postoperative intervertebral height, coronal and sagittal Cobb angle and wound pain at 72 h after operation were compared between two groups. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the cinical effects.

RESULTSNeither wound infection, skin necrosis, nerve root or cauda equia injury, nor worsened neurological dysfunction in the lower limb occurred in each group. There were no significant differences in incision length, intraoperative blood loss and postoperative wound drainage between two groups. The operation time in group A was significantly shorter than that of group B (P < 0.05). There were no significant differences in visual analogue scale value of the wound pain at postoperative 72 h between two groups (P > 0.05). All patients were followed up for 12-48 months,with a mean of 27.5 months. The intervertebral height of all patients had obviously recovered at 5 days after operation, furthermore, at the final follow-up, it still had well maintained. During follow-up, no pedicle screw and/or translaminar facet screw loosening, displacement or breakage and displacement of intervertebral cages were found. The lumbar interbody fusion rate was 96.7% and 96.9% in group A and group B, respectively, and there was no significant difference between two groups (P > 0.05). JOA score of all patients got obviously improved after operation (P < 0.05) and there was no significant difference between two groups (P > 0.05).

CONCLUSIONBoth unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion have advantages of small incision, minimal invasion, simple operation, reliable stability, high interbody fusion rate,rapid recovery, encouraging clinical effects and less complications. Compared with unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation, the operation of unilateral pedicle screw fixation is simpler and can avoid using special equipments. Therefore, unilateral pedicle screw fixation plus lumbar interbody fusion can be used in treating single-segmental lower lumbar vertebra diseases under the precondition of strictly grasping indications for surgery and improving surgical skills.

Adult ; Aged ; Bone Screws ; Female ; Humans ; Lumbar Vertebrae ; surgery ; Male ; Middle Aged ; Spinal Diseases ; surgery ; Spinal Fusion ; methods

BACKGROUNDExtensive atrial fibrillation (AF) ablation is associated with an increased success rate of catheter ablation in chronic AF patients and an increased rate of atrial tachycardia (AT) during the procedure. The mechanism of these ATs varies in previous studies. Our study aimed to report the mechanism of organized AT occurring during the stepwise ablation procedure of chronic AF.

METHODSA prospective cohort of 86 consecutive patients who underwent an ablation procedure for chronic atrial fibrillation (CAF) was investigated. The stepwise procedure was performed in the following order: circumferential pulmonary vein ablation, complex fractionated atrial electrograms ablation, mapping and ablation of AT. The endpoint was noninducibility of AF/AT after sinus rhythm (SR) was restored or the procedure time was beyond 6 hours.

RESULTSSixty-nine (80%) of patients converted to SR via AT. A total of 179 sustained ATs were observed in 69 patients during the procedure. There were 81% (n = 145) macroreentrant ATs which included 65 perimitral circuits, 48 peritricuspid tachycardia and 32 roof dependent circuits, 12% (n = 21) localized reentrant and 7% (n = 13) focal ATs. Thirty (15%) patients experienced significant left atrium (LA) and LA appendage (LAA) conduction delay or dissociation in the procedure or during the follow-up period.

CONCLUSIONSMost CAF patients converted to SR via ablation of organized AT occurring during the stepwise procedure. The mechanism of most of these ATs was macro-reentry.

Aged ; Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Electrophysiology ; Female ; Humans ; Male ; Middle Aged ; Prospective Studies ; Tachycardia, Ectopic Atrial ; surgery ; Treatment Outcome

OBJECTIVETo investigate the advantages and disadvantages of unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion with cages in the treatment of two-level lumbar vertebra diseases, by comparing bilateral pedicle screw fixation and interbody fusion with cages.

METHODSForty-nine patients with two-level lumbar diseases who received treatments from June 2009 to December 2011 were included in this study. Among these patients, 23 patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion with cages (combined fixation group) and the remaining 26 patients underwent bilateral pedicle screw fixation and interbody fusion with cages (bilateral fixation group). These patients consisted of 17 males and 32 females, ranging in age from 29 to 68 years old. Among these patients, lumbar intervertebral disc herniation accompanied by the spinal canal stenosis was found in 29 patients, degenerative lumbar disc diseases in 17 patients and lumbar degenerative spondylolisthesis (degree I) in 3 patients. The lesions occurred at L2,3 and L3,4 segments in 1 patient, at L3,4 and L4,5 segments in 30 patients, and at L4,5 segment and L5S1 segment in 18 patients. Wound length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Intervertebral space height in the lesioned segment before and during surgery and at the latest follow up was also compared between two groups. Before surgery and at the latest follow-up, the Cobb angle of the coronal plane and sagittal plane of the lumbar spine, loosening or breakage of internal fixations, the dislocation of intervertebral cages, and interbody fusion were all evaluated in each group. The visual analogue scale (VAS) was used to measure lumbar incision pain. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the function before surgery and at the latest follow-up.

RESULTSNo wound infection or skin necrosis was observed after surgery in all patients. No cerebrospinal fluid leakage, nerve root injury, cauda equia injury or worsened neural function in the lower limb occurred in all patients during and after surgery. Wound length, operation time, intraoperative blood loss and postoperative wound drainage in the combined fixation group were superior to those in the bilateral fixation group. At postoperative 72 hours, the VAS score in the combined fixation group (1 to 4 points, mean 2.35±1.20) was significantly lower than that in the bilateral fixation group (2 to 5 points, mean 3.11±1.00; P<0.05). All the patients were followed up for 12 to 48 months, with a mean of 29 months. After surgery, intervertebral space height was well recovered in each patient and it was well maintained at the latest follow-up, and there was no significant difference between two groups (P>0.05). During follow-up, pedicle screw and translaminar facet screw loosening, dislocation or breakage and dislocation of intervertebral cages were all not found. At the latest follow-up, the Cobb angle of the coronal plane and sagittal plane of the lumbar spine was obviously improved and was not significantly different between two groups (P>0.05). The lumbar interbody fusion rate was 93.5% and 96.2% in the combined fixation group and bilateral fixation group, respectively, and there was no significant difference between them (P>0.05). There was a significant difference in JOA score between before surgery and at the latest follow-up in each patient (P<0.05), and at the latest follow-up, significant difference in JOA score was found between two groups (P<0.05).

CONCLUSIONCompared to bilateral pedicle screw fixation and lumbar interbody fusion with cages, unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and lumbar interbody fusion with cages shows advantages including small skin incision, minimal invasion, ease of operation, highly reliable stability, high interbody fusion rate, rapid recovery in the treatment of two-level lumbar vertebra diseases and therefore can be preferred as a treatment method of this disease.

Adult ; Aged ; Female ; Humans ; Intervertebral Disc Degeneration ; surgery ; Lumbar Vertebrae ; surgery ; Male ; Middle Aged ; Pedicle Screws ; Spinal Fusion ; methods ; Spinal Stenosis ; surgery ; Spondylolisthesis ; surgery