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Regeneration, relying mainly on resident adult stem cells, is widespread. However, the mechanism by which stem cells initiate proliferation during this process in vivo is unclear. Using planarian as a model, we screened 46 transcripts showing potential function in the regulation of local stem cell proliferation following 48 h regeneration. By analyzing the regeneration defects and the mitotic activity of animals under administration of RNA interference (RNAi), we identified factor for initiating regeneration 1 (Fir1) required for local proliferation. Our findings reveal that Fir1, enriched in neoblasts, promotes planarian regeneration in any tissue-missing context. Further, we demonstrate that DIS3 like 3'-5' exoribonuclease 2 (Dis3l2) is required for Fir1 phenotype. Besides, RNAi knockdown of Fir1 causes a decrease of neoblast wound response genes following amputation. These findings suggest that Fir1 recognizes regenerative signals and promotes DIS3L2 proteins to trigger neoblast proliferation following amputation and provide a mechanism critical for stem cell response to injury.
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Cardiogenic stroke caused by atrial fibrillation is the most harmful type of stroke, causing great social burden. Prevention and treatment of cardiogenic stroke often require the joint decision by the cerebrovascular physicians and cardiologists. Within 14 d after onset, the early stage of stroke, is a high-risk period of stroke recurrence and also a highrisk period of cerebral hemorrhage. In this period, how to prevent stroke recurrence is an urgent problem to be solved. This paper summarizes the main ways of secondary prevention for cardiogenic stroke caused by atrial fibrillation and discusses the possibility of early secondary prevention.
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This article has been retracted at the request of the Editor. The authors have plagiarized part of a paper where the data has been taken from another group of scientists. Readers can find the original Mingzhi Shen's Ph.D thesis, written in Chinese language, Role of Thioredoxin-interacting protein (TXNIP)-Wnt in diabetic myocardial infarction-induced angiogenetic suppression which is included in CNKI (China National Knowledge Infrastructure), http://cdmd.cnki.com.cn/Article/CDMD-90032-1014047242.htm. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
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<p><b>BACKGROUND</b>Lack of fluoroscopic landmarks can make valve deployment more difficult in patients with absent aortic valve (AV) calcification. The goal of this article was to evaluate the feasibility and effectiveness of transcatheter implantation of a valved stent into the AV position of a goat, assisted with a microcatheter which provides accurate positioning of coronary artery ostia to help valved stent deployment.</p><p><b>METHODS</b>The subjects were 10 healthy goats in this study. A microcatheter was introduced into the distal site of right coronary artery (RCA) through femoral artery sheath. A minimal thoracic surgery approach was used to access the apex of the heart. The apex of the left ventricle was punctured; a delivery catheter equipped with the valved stent was introduced over a stiff guidewire into the aorta arch. We could accurately locate the RCA ostia through the microcatheter placed in the RCA under fluoroscopy. After correct valve position was confirmed, the valved stent was implanted after rapid inflation of the balloon. The immediate outcome of the function of the valved stents was evaluated after implantation.</p><p><b>RESULTS</b>All ten devices were successfully implanted into the AV position of the goats. Immediate observation after the procedure showed that the valved stents were in the desired position after implantation by angiography, echocardiogram. No obstruction of coronary artery ostia occurred, and no moderate to severe aortic regurgitation was observed.</p><p><b>CONCLUSIONS</b>When the procedure of transcatheter implantation of a balloon-expandable valved stent into the AV position of goats is assisted with microcatheter positioning coronary artery ostia, the success rate of operation can be increased in those with noncalcified AV.</p>
Subject(s)
Animals , Female , Male , Aortic Valve , General Surgery , Goats , Heart Valve Prosthesis Implantation , Methods , Transcatheter Aortic Valve Replacement , MethodsABSTRACT
<p><b>BACKGROUND</b>Permanent atrial fibrillation (AF) is the most common form of dysrhythmia associated with atrial septal defects (ASDs) in patients older than 40 years. However, little is known about cardiac remodeling after transcatheter closure in patients with permanent AF. This study was designed to compare cardiac events and remodeling effects after transcatheter closure in such patients.</p><p><b>METHODS</b>Clinical data of 289 adult patients older than 40 years who underwent ASD closure at our center were analyzed retrospectively. Of them, 63 patients with permanent AF were assigned to the case group, and the other 226 patients without permanent AF were assigned to the control group. Cardiac events and changes in left and right cardiac cavity dimensions before the procedure and 6 months after the procedure were compared between the two groups.</p><p><b>RESULTS</b>Patients in the case group were significantly older than those in the control group. The right ventricular (RV) volume and right atrial (RA) volume were decreased significantly in both the groups during a median follow-up period of 6 months after closure (P < 0.001). The left atrial dimensions, left ventricular end-systolic dimensions, left ventricular end-diastolic dimensions and left ventricular ejection fraction showed no significant change before and after the procedure in both the groups. Changes of the RV volume and RA volume in the case group were significantly smaller than those in the control group (P = 0.005 and P < 0.001). The New York Heart Association cardiac function was improved in both the groups during the 6 months follow-up period.</p><p><b>CONCLUSIONS</b>The transcatheter closure of ASD can improve the cardiac remodeling and cardiac function in patients with or without AF.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Atrial Fibrillation , Therapeutics , Cardiac Catheterization , Methods , Heart Septal Defects, Atrial , Therapeutics , Retrospective StudiesABSTRACT
OBJECTIVE@#To explore the regulatory role of thioredoxin-interacting protein (TXNIP) in Wnt/β-catenin signaling pathway and therefore to elucidate its function in diabetic myocardial infarction.@*METHODS@#Diabetic myocardial infarction models were generated in mice. The expression levels of TXNIP and β-catenin and level of reactive oxygen species (ROS) were determined and compared with those in control group. Human umbilical vein endothelial cells were treated with high-concentration glucose and/or silencing TXNIP and/or H2O2. After 24 h, expression levels of TXNIP, β-catenin and its downstream protein Cyclin D1, and C-myc gene were determined by real-time PCR, Western blot and immunofluorescence method. The cell proliferation and ROS production capability in different groups were determined by methyl thiazolyl tetrazolium assay.@*RESULTS@#Compared with control group, hyperglycemia significantly up-regulated TXNIP expression and ROS level in the myocardium and endothelial cells of myocardial infarction area, whereas the β-catenin expression was down-regulated, and the difference was statistically significant (P < 0.05). In comparison with Human umbilical vein endothelial cells in the control group, high glucose level increased the levels of TXNIP expression and ROS level in cells, but reduced cell proliferation as well as migration capability and expression levels of β-catenin, Cyclin D1 and C-myc; the difference was statistically significant (P < 0.05). However, this trend can be partially reversed by silencing TXNIP.@*CONCLUSIONS@#Diabetic myocardial ischemia could up-regulate levels of TXNIP expression and ROS production in endothelial cells of myocardial infarction area. The regulation effect of TXNIP on β-catenin was partially achieved by changing ROS levels.
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Objective: To explore the regulatory role of thioredoxin-interacting protein (TXNIP) in Wnt/β-catenin signaling pathway and therefore to elucidate its function in diabetic myocardial infarction. Methods: Diabetic myocardial infarction models were generated in mice. The expression levels of TXNIP and β-catenin and level of reactive oxygen species (ROS) were determined and compared with those in control group. Human umbilical vein endothelial cells were treated with high-concentration glucose and/or silencing TXNIP and/or H
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<p><b>OBJECTIVE</b>To evaluate the safety and efficacy of transcatheter closure of ruptured aneurysm of the sinus of Valsalva (RAVS) using a domestic made small-waist ventricular septal defect occluder.</p><p><b>METHODS</b>Between September 2005 and December 2010, transcatheter closure of RAVS was randomly performed in 7 patients of (43.5 ± 13.0) years old using domestic made small-waist ventricular septal defect occluder in our department. RAVS was diagnosed by color Doppler echocardiography. The size of the small-waist double-disk occlude selected was 4 to 6 mm larger than the narrowest diameter of the opening of aneurysm. After establishment of the arteriovenous wire loop, the device was deployed by retrograde venous approach in all patients. All patients were followed up in terms of rhythm change, residual shunt, shape of occlude, and possible valve regurgitation by echocardiography for 6 to 12 months.</p><p><b>RESULTS</b>All RAVS were confirmed by aortography. Aortography showed rupture of right coronary sinus into the right ventricle in 6 patients and non-coronary sinus ruptured into right ventricle in another patient. The estimated size of the defect was 4 to 7 (5.0 ± 1.3) mm by aortogram. Ventricular septal defect was evidenced in 2 patients. All defects were successfully occluded without complication. Two patients with ventricular septal defect received combined percutaneous ventricular septal defect closure. After transcatheter RAVS occlusion, pulmonary artery systolic pressure decreased from (35.6 ± 12.7) mm Hg (1 mm Hg = 0.133 kPa) to (27.4 ± 6.2) mm Hg (P < 0.05), and mean pulmonary artery pressure decreased from (21.9 ± 8.0) mm Hg to (16.1 ± 5.3) mm Hg (P < 0.05). Cardiac murmur disappeared right after successful occlusion. Echocardiography detected a trace of residual shunt in one patient after occlusion which disappeared the next day. There was no aortic regurgitation, hemolysis and arrhythmia during hospitalization. There was no device embolization, infective endocarditis, right heart failure and death during the 6 to 12 months follow-up.</p><p><b>CONCLUSION</b>Transcatheter closure of RAVS with the domestic made small-waist ventricular septal defect occluder is safe and effective.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Aneurysm, Ruptured , General Surgery , Cardiac Catheterization , Methods , Heart Aneurysm , Septal Occluder Device , Sinus of Valsalva , Pathology , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To evaluate the efficacy and adverse effects of transcatheter closure of perimembranous ventricular septal defect (pmVSD) with modified double-disk occluder device (MDVO).</p><p><b>METHODS</b>Clinical data including clinical examination, electrocardiography daily after the procedure for a week, chest-X-rays and TTE before discharge and at 3-5 days after the procedure were analyzed from 604 patients underwent percutaneous closure of a pmVSD with MDVO at our department between December 2001 and December 2008.</p><p><b>RESULTS</b>Procedure was successful in 576 out of 604 patients (95.4%) and 583 VSD occluders were placed. Endocarditis, thromboembolism, or deaths were not observed after procedure. Conduction block occurred in 81 patients (56 RBBB, 14 LBBB) and transient nonparoxysmal ventricular tachycardia in 31 patients after the procedure. Complete heart block occurred in 11 patients, 9 of them recovered in 3 weeks, permanent pacemaker was implanted in 2 patients (one had transient III degrees AVB before the procedure, the other underwent simultaneous closure of ventricular septal defect and atrial septal defect). Trivial/small residual shunts were found in 69 patients (12.0%). The residual shunts disappeared in 31 patients and remained unchanged in 38 patients (6.6%) 7 days after procedures. Aortic regurgitation developed in 5 patients (2 trivial/small, 3 small/moderate), and tricuspid regurgitation was present in 35 patients (32 trivial/small, 3 moderate). Five patients developed haemolysis (device retrieved via catheter in 1 patient due to persistent haemolysis, the other 4 patients recovered 3-14 days post procedure). Pseudoaneurysm of femoral artery occurred in 1 patient, and disappeared by pressure dressing. Device was successfully replaced in 2 patients with either device embolization (n = 1) or device misplacement (n = 1) after device retrieval by catheter.</p><p><b>CONCLUSION</b>It is safe and effective to close congenital perimembranous ventricular septal defect with domestic-made occluder device.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Balloon Occlusion , Cardiac Catheterization , Echocardiography , Heart Septal Defects, Ventricular , Therapeutics , Treatment OutcomeABSTRACT
<p><b>BACKGROUND</b>Pulmonary regurgitation leads to progressive right ventricular dysfunction, susceptibility to arrhythmias, and sudden cardiac death. Percutaneous valve replacement has been developed in recent years, providing patients with an alternative option. Percutaneous pulmonary valve replacement has been recently introduced into clinical practice. The goal of this study was to evaluate the feasibility of percutaneous valve stent insertion to correct the pulmonary regurgitation in sheep using a cup-shaped valve stent.</p><p><b>METHODS</b>Pulmonary regurgitation was created by percutaneous cylindrical stent insertion in native pulmonary annulus of 8 sheep. One month after the initial procedure, the sheep with previous cylindrical stent implanted underwent the same implantation procedure of pulmonary valve stent. The valve stent consisted of a cup-shaped stent and pericardial valves. Hemodynamic assessments of the bioprosthetic pulmonary valve were obtained by echocardiography at immediately post-implant and at 2 months follow up.</p><p><b>RESULTS</b>Successful transcatheter cylindrical stent insertion was performed in 7 sheep but failed in 1 sheep because the cylindrical stent was released to right ventricle outflow tract. After one month the 7 sheep with pulmonary regurgitation underwent valve stent implantation successfully. Echocardiography confirmed the stents were in desired position during the follow-up. No evidence of pulmonary valve insufficiency occurred in any animals. Echocardiography showed all heart function markers were normal.</p><p><b>CONCLUSIONS</b>Percutaneous cylindrical stent insertion to induce significant pulmonary regurgitation in sheep was feasible, simple and reproducible. Percutaneous pulmonary valve stent implantation can reduce pulmonary regurgitation in a sheep model. Further development of animal model and clinical trials are warranted.</p>
Subject(s)
Animals , Female , Male , Feasibility Studies , Heart Valve Prosthesis , Heart Valve Prosthesis Implantation , Pulmonary Valve Insufficiency , General Surgery , SheepABSTRACT
<p><b>BACKGROUND</b>Valve replacement or repair is recommended in patients with tricuspid regurgitation when deterioration of their clinical status occurs as a consequence of right ventricular dysfunction. Percutaneous valve replacement was developed in recent years. To investigate the feasibility, effectiveness and long-term results of percutaneous tricuspid valve replacement, an experimental model with tricuspid regurgitation is needed. We developed a simple and reproducible percutaneous approach for the creation of tricuspid regurgitation in sheep.</p><p><b>METHODS</b>A specially designed grasping forceps were used to grasp chordae tendineae or the tricuspid valve leaflets through a catheter. Transcatheter creation of tricuspid regurgitation was performed on 7 healthy sheep. These sheep were followed up shortly after the procedure and at 6th month post-procedure with echocardiography. Additionally, all the sheep were sacrificed for anatomic evaluation at 6th month after the procedure.</p><p><b>RESULTS</b>Creation of tricuspid regurgitation was successfully accomplished in all sheep. Necropsy confirmed that damage was done to the tricuspid valve apparatus in all animals (tearing of the anterior leaflet of the tricuspid valve in five animals and posterior leaflet of the tricuspid valve in two animals). At the six-month follow-up, there was no significant increase in the right ventricle dimension and ejection fraction measured by echocardiography. Autopsy examinations demonstrated the tearing of tricuspid valve leaflets.</p><p><b>CONCLUSIONS</b>The creation of an animal model of tricuspid regurgitation via a percutaneous approach using forceps to sever one or more tricuspid leaflets is feasible and will allow investigation of devices designed replace the tricuspid valve via a percutaneous approach. Despite significant tricuspid regurgitation, the hemodynamics did not change during the follow-up period in this model.</p>
Subject(s)
Animals , Female , Male , Catheterization , Disease Models, Animal , Echocardiography , Heart Valve Prosthesis Implantation , Methods , Sheep , Tricuspid Valve Insufficiency , TherapeuticsABSTRACT
<p><b>BACKGROUND</b>Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. However, the clinical experience is still limited. We developed a W-model valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the native aortic valve position.</p><p><b>METHODS</b>A self expanding nitinol stent with W-model, containing porcine pericardium valves in its proximal part, was implanted in six sheep by means of a 14 French catheter through the right common iliac artery under guidance of fluoroscopy. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. These sheep were followed up shortly after procedure with supra-aortic angiogram and left ventriculography. Additionally, one sheep was sacrificed after the procedure for anatomic evaluation.</p><p><b>RESULTS</b>It was possible to replace the aortic valve in the beating heart in four sheep. The procedure failed in two sheep due to coronary orifice occlusion in one case and severe aortic valve regurgitation in the other case. One sheep was killed one hour after percutaneous aortic valve replacement for anatomic evaluation. There were no signs of damage of the aortic intima, or of obstruction of the coronary orifice.</p><p><b>CONCLUSIONS</b>Percutaneous aortic valve replacement with a W-model valved stent in the beating heart is possible. Further studies are mandatory to assess safety and efficacy of this kind of valved stent in larger sample size and by longer follow-up period.</p>
Subject(s)
Animals , Female , Male , Aortic Valve , Pathology , General Surgery , Aortic Valve Stenosis , General Surgery , Feasibility Studies , Fluoroscopy , Heart Valve Prosthesis Implantation , Methods , Sheep , StentsABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to determine the feasibility of transcatheter pulmonary valve replacement in sheep up to 6 months post procedure.</p><p><b>METHODS</b>Fresh sheep pericardium treated with a 0.6% glutaraldehyde solution for 36 hours was sutured to a valvular ring and then fixed onto a newly designed nitinol self-expandable stent. Thoracotomy was performed in sheep (23.5 +/- 3.1) kg under general anesthesia and the device was delivered into the native pulmonary valve of the sheep via the anterior wall of right ventricle by catheter and fooled for 6 months.</p><p><b>RESULTS</b>One sheep died 4 months after the procedure due to in-stent thrombosis. Another 4 animals survived the 6-month observing period. Angiographic and hemodynamic measurements confirmed good positioning and function of the stents with a competent valve immediately post procedure and 6 months post the procedure in surviving animals.</p><p><b>CONCLUSION</b>Implantation of the nitinol self-expandable stent in the pulmonary valve position by a transcatheter approach is feasible and good function of transcatheter implanted memory nitinol valved stents was shown after 6 months of implantation in sheep.</p>