The changes of aerodynamic parameters in the tracheal stenosis before and after stent implantation and their clinical significance / 介入放射学杂志

Objective To explore the changes of the aerodynamic parameters in tracheal stenosis before and after stent implantation,and to discuss the significance of these changes.Methods The clinical data of 20 patients with tracheal stenosis,who were treated with stent implantation,were collected,and the clinical features as well as imaging findings were summarized.Using the computer fluid dynamics analysis software,the airflow dynamics simulation study on tracheal stenosis before and after stent implantation was conducted.The aerodynamic parameters of the region of interest were recorded and statistically analyzed.The mean values of quantitative data were compared by using t-test,and P＜0.05 was considered to be statistically significant.Results The nature of tracheal stenosis was malignant in all 20 patients,which was caused by tumor compression and invasion.Stenosis degree ＞50％ was seen in 18 patients,the stenosis was located in the middle of trachea in 10 patients,segmental stenosis was observed in 15 patients,and eccentric stenosis was found in 17 patients.After stent implantation,the lumen area at previous tracheal stenosis site became (2.03±0.32) cm2,which was larger than (0.96±0.18) cm2 measured before stent implantation.The pre-stenting velocity at the stenotic site of trachea was (1764±1484) cm/s,which was higher than (688±434) cm/s of the post-stenting velocity.The pre-stenting velocity and volume flow measured at the left main bronchus entrance were (308±209) cm/s and (359±255) ml/s respectively,both of them were smaller than those measured at the right main bronchus entrance,which were (464±246) cm/s and (526±283) ml/s respectively,the differences were statistically significant (both P＜0.05).After tracheal stent implantation,the differences in the velocity and volume flow between the left main bronchus entrance and the right main bronchus entrance were not statistically significant.Conclusion The aerodynamic parameters in tracheal stenosis are characterized by the presence of a high velocity of air flow at the stenosis site,and the stenosis of trachea has an effect on the velocity and volume flow at both left and fight main bronchus entrances.Tracheal stenting can remarkably increase the lumen area at tracheal stenosis site,reduce the high velocity at the stenotic site and make the airflow smoother,and the bronchial airflow of the right and left side can be balanced.The airflow dynamics simulation of tracheal stenosis before and after stent implantation has a certain value for the pathophysiological study of tracheal stenosis and for the evaluation of therapeutic effect.

Cloning,expression and bioinformatics analysis of cathepsin B of Echino-coccusgranulosus / 中国血吸虫病防治杂志

Objective To clone and express cathepsin B gene of Echinococcus granulosus(EgCatB)and analyze EgCatB protein by using bioinformatics tools and online databases. Methods The total RNA of E. granulosus was extracted and reverse?ly transcribed into cDNA as the template sequence for PCR. The EgCatB gene was cloned by using the In?Fusion PCR cloning method and expressed by a wheat germ cell?free system,and then the recombinant protein was identified by Western blotting. The signal peptide,transmembrane helices and subcellular location of the EgCatB sequence were predicted by the online soft?ware SignalP 4.1,TMHMM sever v. 2.0 and TargetP 1.1 respectively. Subsequently,the homologue sequence and conserved sites were aligned by using BLASTP and GeneDoc software. Finally,the structures and the glycosylation modification site of the EgCatB encoding protein were analyzed and predicted in turn by ProtParam,SMART,Predictprotein,Swiss?model,NetOGlyc 4.0 and NetNGlyc 1.0 approaches. Results The EgCatB gene was successfully amplified from cDNA of E. granulosus and ex?pressed in the soluble fractions. The molecular weight of the expressed protein was estimated 35 kDa. The bioinformatics analysis revealed that EgCatB was a classical secreted protein containing a Pept_C1 domain. The homology analysis indicated that the amino acid sequence of EgCatB was highly conserved in the active enzyme sites. The protein structure prediction showed a cata?lytic active center was formed through Gln106,Cys112,His282 and Asn302. It was found that there were nine O?glycosylation sites in the EgCatB sequence,but no N?glycosylation sites. Conclusions The EgCatB gene is cloned and expressed successfully,and the recombinant protein is analyzed by bioinformatics approaches and structure predication. The study provides useful informa? tion for further functional study of the EgCatB protein.

Clinical analysis of transcatheter closure of atrial septal defects in elderly patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the clinical feature of patients with atrial septal defects (ASD) and the safety and efficacy of transcatheter closure of ASD in elderly patients.</p><p><b>METHODS</b>Between May 2000 and June 2010, 82 patients aged (64.5 ± 3.8) years underwent attempted transcatheter ASD closure. Right heart catheterization was performed before intervention. Echocardiography was made at 1 day, 1, 3, 6 months after the procedure. The pre- and post-closure clinical feature, pulmonary artery pressure (PAP) and cardiac function were evaluated.</p><p><b>RESULTS</b>In 82 patients, 37 (45.1%) patients were associated with pulmonary arterial hypertension (PAH). The systolic PAP and mean PAP [(44.1 ± 12.4) mm Hg (1 mm Hg = 0.133 kPa) and (25.2 ± 6.8) mm Hg, respectively] were measured by right heart catheterization before the procedure. One patient was unsuitable for closure because of severe PAH. The remaining 81 patients underwent successful ASD closure without major complications. After closuring, systolic PAP decreased from (52.7 ± 10.3) mm Hg to (31.8 ± 6.3) mm Hg (P < 0.05), and mean PAP descended from (30.9 ± 4.7) mm Hg to (21.8 ± 3.4) mm Hg (P < 0.05) in the 36 patients with PAH. The cardiac function improved post procedure. There were 6 new-onset atrial fibrillations during follow up.</p><p><b>CONCLUSIONS</b>ASD in elderly patients are commonly associated with PAH. Transcatheter ASD closure is safe and effective in the majority of elderly patients.</p>

The role of ADAMTSs in arthritis

The ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family consists of 19 proteases. These enzymes are known to play important roles in development, angiogenesis and coagulation; dysregulation and mutation of these enzymes have been implicated in many disease processes, such as inflammation, cancer, arthritis and atherosclerosis. This review briefly summarizes the structural organization and functional roles of ADAMTSs in normal and pathological conditions, focusing on members that are known to be involved in the degradation of extracellular matrix and loss of cartilage in arthritis, including the aggrecanases (ADAMTS-4 and ADAMTS-5), ADAMTS-7 and ADAMTS-12, the latter two are associated with cartilage oligomeric matrix protein (COMP), a component of the cartilage extracellular matrix (ECM). We will discuss the expression pattern and the regulation of these metalloproteinases at multiple levels, including their interaction with substrates, induction by pro-inflammatory cytokines, protein processing, inhibition (e.g., TIMP-3, alpha-2-macroglobulin, GEP), and activation (e.g., syndecan-4, PACE-4).

Radiofrequency perforation and balloon valvuloplasty in infants with pulmonary atresia and intact ventricular septum / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the efficacy and safety of percutaneous radiofrequency perforation and valvuloplasty in infants with pulmonary atresia with intact ventricular septum (PA/IVS).</p><p><b>METHODS</b>Four infants (body weight 4 - 10 kg) aged 11 months, 9 months, 12 days and 9 months old, respectively, were hospitalized for dyspnea and cyanosis. All patients had a continuous murmur in the left second intercostal space. Doppler echocardiogram showed membranous pulmonary atresia with intact ventricular septum. Right ventriculogram showed a tripartite right ventricle, vasiform infundibulum, and membranous pulmonary valve atresia without ventriculocoronary connections. Descending thoracic aortogram showed good-sized confluent pulmonary arteries being filled from a ductus arteriosus. All the patients were taken up for radiofrequency perforation followed by a balloon dilatation. A 6F Judkins right coronary guiding catheter was positioned in the right ventricular outflow tract and under the atretic pulmonary valve membrane. The radiofrequency perforation catheter along with coaxial injectable catheter was then passed through the right coronary guiding catheter, using it as the guide to the imperforate membrane. The proximal end of the radiofrequency perforation catheter was then connected to radiofrequency generator. After the cusps of pulmonary valve were perforated, the coaxial injectable catheter was moved into the main pulmonary artery. A tiny floppy-tipped coronary guidewire was then passed through the coaxial injectable catheter into the main pulmonary artery and directed through the patent ductus arteriosus into the descending thoracic aorta or directed into pulmonary arteriola. Thereafter, serial balloon dilation catheters were introduced across the pulmonary valve, and dilations were sequentially performed with increasing balloon diameters. The balloon was dilated until the concave of the balloons disappeared. The radiofrequency energy (5 to 8 W) was delivered for 2 to 5 seconds once, but commonly twice, to perforate the valves. After a predilation with a 3 mm x 20 mm to 5 mm x 20 mm balloon at 6 - 14 atm pressure, the valve was subsequently dilated with 10 mm x 30 mm to 14 mm x 30 mm balloon once or twice. The duration of procedures was 120 to 150 min and exposure time was 25.4 to 43.9 min.</p><p><b>RESULTS</b>The primary procedure was successful in all the infants except one who died early of cardiac perforation with tamponade. After a follow-up period ranging from 2 to 8 months (mean 4.3 m), the remaining 3 survivors achieved complete biventricular circulation. Two of them were awaiting occlusion of the patent ductus arteriosus and 1 needed right ventricular outflow tract reconstruction because of infundibular obstruction.</p><p><b>CONCLUSION</b>PA/IVS consists of 0.7% to 3.1% of congenital heart defects. 85% of the untreated patients die within half a year. Surgical repair for the infants with PA/IVS is associated with a high mortality. In carefully selected patients with PA/IVS, radiofrequency perforation and balloon dilatation of the pulmonary valve is feasible and may represent a new alternative to surgery due to its low mortality and avoidance of cardiopulmonary bypass.</p>

Risk factors for early arrhythmias post transcatheter closure of perimembranous ventricular septal defects / 中华心血管病杂志

<p><b>OBJECTIVE</b>To analyze the risk factors for early arrhythmias after transcatheter closure of perimembranous ventricular septal defect (PVSD).</p><p><b>METHODS</b>A total of 358 patients [161 males, aged from 3 to 54, mean (10.9 +/- 8.1) years, body weight from 12 to 90, mean (32.8 +/- 17.2) kg] who underwent transcatheter closure of PVSD from August 2002 to February 2006 were included in this retrospective analysis. Electrocardiogram was performed daily after transcatheter closure for seven days. Relationships between arrhythmias and those risk factors such as the defect characteristics and the device size and types were explored by logistic regression analysis. Left ventriculography showed 195 out of 358 patients with PVSD were complicated with membranous aneurysm. The PVSD diameter ranged from 2 to 18 (6.5 +/- 3.1) mm in left ventricular side and from 2 to 12 (4.2 +/- 2.3) mm in right ventricular side. A total of 140 nonsymmetrical and 218 symmetrical occluders with diameter 4 to 18 (8.1 +/- 2.5) mm were used to close those defects.</p><p><b>RESULTS</b>Procedure was successful in all patients. Early arrhythmias after transcatheter closure of PVSD were observed in 135 (37.7%) patients and serious cardiac arrhythmias in 23 (6.4%) patients. The early arrhythmias after transcatheter closure of PVSD were significantly correlated with device size [> or = (8.6 +/- 2.7) mm] and type (nonsymmetrical device), the span between the defect and tricuspid (< or = 3 mm), and the presence of aneurysm.</p><p><b>CONCLUSION</b>Larger device size, nonsymmetrical device, narrow span between the defect and tricuspid and the presence of aneurysm are the risk factors for early arrhythmias after transcatheter closure of PVSD.</p>

Transcatheter closure of atrial septal defects in 40 pediatric patients / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical efficiency of transcatheter closure of atrial septal defect (ASD) with AGA-Amplatzer occlusion device in pediatric patients.</p><p><b>METHODS</b>Forty patients with ASD, 16 males, 24 females, at a mean age of 10.2 years (ranged from 3 to 15 years of age) and with a mean weight of 35.8 kg (ranged from 11 to 87 kg) were studied. Six cases were complicated with pulmonary stenosis (PS), 1 was complicated with ventricular tachycardia (VT). Right heart catheterizations were done in 40 patients for measuring the pressures of right ventricle and pulmonary artery. The balloon diameter of ASD was measured using balloon catheter with guiding wire. The diameter of ASD was measured by TTE and/or TEE, ascertaining the location and size of ASD. Amplatzer occlusion device was sized to be equal to or 1 - 2 mm more than the diameter of balloon stretched.</p><p><b>RESULTS</b>All patients had successful implantation of the Amplatzer device. The success rate was 100%. The diameter measured by TTE was 7 - 30 mm (mean 17.12 mm). The diameter measured by TEE was 7 - 32 mm (mean 18.44 mm). The diameter of balloon stretched of ASD was 8 - 34 mm. Of the 40 cases, 6 were complicated with PS and accepted percutaneous balloon valvuloplasty (PBPV). One case was complicated with VT and accepted radiofrequency catheter ablation (RFCA). Neither complication nor residual shunt was found in any of the patients. The patients were recovered and followed up for 3 or 4 days after deployment of the Amplatzer device. Clinical symptom, cardiac murmur, and findings in ECG, echocardiography and X-ray were improved markedly.</p><p><b>CONCLUSION</b>AGA-Amplatzer occlusion device is safe and efficient in pediatric patients with ASD.</p>