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Complete Closure (complete + closure)
Selected AbstractsDiode laser photocoagulation of choroidal neovascularization associated with retinal pigment epithelial detachmentACTA OPHTHALMOLOGICA, Issue 1 2001Francisco Gomez-Ulla ABSTRACT. Aims/Background: Association of choroidal neovascularization with pigment epithelial detachment is not an uncommon feature. Since this condition usually has a poor visual outcome, new treatments should be developed. Methods: We studied the anatomical and visual results of 11 eyes with this association as a manifestation of an Exudative Age Related Macular Degeneration which were treated with diode laser photocoagulation guided by indocyanine green angiography. The average follow up time was 25.5 months (from 12 to 48 months). Results: Complete closure with complete resolution of the exudates and flattening of the detachment was observed in five eyes (45%). Visual acuity in the final examination improved or remained stable in 6 cases (55%). Conclusion: These results indicate that diode laser photocoagulation guided by indocyanine green angiography is at least as effective as conventional lasers with shorter wavelengths for treatment of vascularized pigment epithelial detachments in Age Related Macular Degeneration. [source] Healing of Venous Ulcers of Long Duration with a Bilayered Living Skin Substitute: Results from a General Surgery and Dermatology DepartmentDERMATOLOGIC SURGERY, Issue 11 2001Harold Brem MD Background. A laboratory-grown bilayered living skin substitute (LSS) has been shown to accelerate the healing of venous ulcers. However, issues related to optimal wound bed preparation prior to the application of LSS have not been addressed. Objective. When combined with standard compression therapy and near elimination of wound exudate, bioengineered skin can achieve complete closure of venous ulcers which have been present for more than a year and which are difficult to heal. Methods. In the general surgery (center A) and dermatology (center B) departments at two separate medical centers, LSS was used to treat venous ulcers of more than 1 year's duration and which had been unresponsive to conventional therapy. Wound bed preparation at both centers had as common goals the removal of necrotic tissue, optimal formation of granulation tissue, and elimination of wound exudate. Results. There was great comparability between the two centers in the patients being treated, wound size and duration, and number of LSS applications. Both centers achieved a frequency of complete wound closure of greater than 70% within 6 months. Conclusion. At two separate clinical and specialty sites having a common goal of optimal wound preparation, treatment with LSS was associated with a high rate of complete closure of hard to heal venous ulcers. [source] Closure of the Greater Saphenous Vein with Endoluminal Radiofrequency Thermal Heating of the Vein Wall in Combination with Ambulatory Phlebectomy: Preliminary 6-Month Follow-upDERMATOLOGIC SURGERY, Issue 5 2000Mitchel P. Goldman MD Background. Incompetence of the saphenofemoral junction with reflux into the greater saphenous vein is one cause of chronic venous hypertension which may lead to the development of varicose and telangiectatic leg veins. Therefore treatment is necessary. Objective. To evaluate a novel method for closing the incompetent greater saphenous vein at its junction with the femoral vein through an endoluminal approach. Methods. Ten patients with reflux at the saphenofemoral junction into the greater saphenous vein were treated with radiofrequency heating of the vein wall through an endoluminal catheter. Patients were evaluated at 3 and 6 months to determine treatment efficacy as well as adverse sequelae. Results. All treated patients achieved complete closure of the saphenofemoral junction and greater saphenous vein. Complete treatment took an average of 20 minutes. Adverse sequelae were minimal, with 2 of 12 patients having mild erythema for 2,3 days. Conclusion. Endoluminal radiofrequency thermal heating of an incompetent greater saphenous vein has been shown to be easily accomplished and efficacious throughout the 6-month follow-up period. [source] The effects of stream canopy management on macroinvertebrate communities and juvenile salmonid production in a chalk streamFISHERIES MANAGEMENT & ECOLOGY, Issue 2 2009W. D. RILEY Abstract, The effects of changes in shading (through riparian canopy removal and re-growth) on juvenile salmon, Salmo salar L., trout, Salmo trutta L., and grayling, Thymallus thymallus (L.) populations, and macroinvertebrate biomass and species composition in a chalk stream in southern England were examined. Low levels of in-stream weed growth, because of shading by closed tree canopy, diminished macroinvertebrate production and diversity. 0+ salmon and trout had lower densities under closed canopy, relative to adjacent open sites with substantial weed cover, where fish were also found to be larger. Canopy removal positively affected the growth of aquatic macrophytes and the availability of potential prey for juvenile salmonids. The findings have implications for the management of chalk streams, in particular, that riparian tree canopy should be managed to prevent complete closure, and excessive cutting of weed should be avoided where salmon production is below sustainable levels. [source] Molecular dynamics in the formation process of single-walled carbon nanotubesHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 8 2003Yasushi Shibuta Abstract The mechanism of the nucleation and formation of single-walled carbon nanotubes (SWNTs) was investigated using molecular dynamics simulations. When the initial state was chosen so that carbon and nickel atoms were randomly distributed in a simulation domain, the formation of a random cage structure made up of carbon atoms, which had a few nickel atoms inside it, was observed by 6 ns. The nickel atoms, which move inside or on the surface of the cage, were seen to be preventing the complete closure of the cage and its anneal into the fullerene structure. Further, in order to observe a longer time-scale growth process, the simulation cell was artificially shrunk by the progress of simulation so that collisions between precursor clusters were promoted to comply with the limitation in the calculation time. Collisions of the imperfect random-cage clusters led to an elongated tubular cage structure, which could be regarded as an initiation of SWNTs. The simulation results were compared with FT-ICR mass spectra of the positive clusters generated by a laser-vaporization supersonic-expansion cluster beam source. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(8): 690,699, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10123 [source] The purse-string suture revisited: a useful technique for the closure of cutaneous surgical woundsINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 4 2007Philip R. Cohen MD The purse-string suture provides complete or partial closure of round postoperative skin defects. It is a rapid and simple procedure to perform. Tension placed on the suture uniformly advances the skin from the entire periphery of the wound, resulting in a significant reduction of the defect size and enhancement of hemostasis at the wound edge. The history, modifications of the technique, advantages, and potential complications of the purse-string suture are reviewed. It is not only useful following the removal of nonmelanoma skin cancer but also after the local excision of melanoma. In addition, this technique is especially suitable for the repair of round surgical wounds for patients who are unable to modify their active lifestyles during the week following surgery, individuals concurrently being treated with anticoagulants, antiplatelet agents or both, and people with extensive postoperative defects that would otherwise require either a skin graft or a large cutaneous flap. Typically, the site of the surgical wound following partial or complete closure with the purse-string suture demonstrates excellent long-term cosmetic and functional results. [source] Impaired healing response of periodontal furcation defects following flap debridement surgery in smokersJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2003A controlled clinical trial Abstract Objectives: The purpose of the present parallel-design, controlled clinical trial was to evaluate the treatment outcome of periodontal furcation defects following flap debridement surgery (FDS) procedure in cigarette smokers compared to non-smokers. Materials and Methods: After initial therapy, 31 systemically healthy subjects with moderate to advanced periodontitis, who presented at least one Class I or II molar furcation defect, were selected. Nineteen patients (mean age: 40.3 years, 15 males) were smokers (,10 cigarettes/day) and 12 patients (mean age: 44.8 years, 3 males) were non-smokers. Full-mouth plaque score (FMPS) and full-mouth bleeding score (FMBS), probing pocket depth (PPD), vertical clinical attachment level (v-CAL), and horizontal clinical attachment level (h-CAL) were assessed immediately before and 6 months following surgery. Results: Overall, statistically significant v-CAL gain was observed in smokers (1.0 ± 1.3 mm) and non-smokers (1.3±1.1 mm), the difference between groups being statistically significant (p=0.0003). In proximal furcation defects, v-CAL gain amounted to 2.3±0.7 mm in non-smokers as compared to 1.0±1.1 mm in smokers (p=0.0013). At 6 months postsurgery, non-smokers presented a greater h-CAL gain (1.3±1.1 mm) than smokers (0.6±1.0 mm), with a statistically significant difference between groups (p=0.0089). This trend was confirmed in both facial/lingual (1.4±1.0 versus 0.8±0.8 mm) and proximal furcation defects (1.2±1.3 versus 0.5±1.2 mm). The proportion of Class II furcations showing improvement to postsurgery Class I was 27.6% in smokers and 38.5% in non-smokers. After 6 months, 3.4% of presurgery Class I furcation defects in smokers showed complete closure, as compared to 27.8% in non-smokers. Conclusions: The results of the present study indicated that (1) FDS produced clinically and statistically significant PPD reduction, v-CAL gain, and h-CAL gain in Class I/II molar furcation defects, and (2) cigarette smokers exhibited a less favorable healing outcome following surgery in terms of both v-CAL and h-CAL gain. Zusammenfassung Ziele: Der Zweck der vorliegenden kontrollierten klinischen Studie mit einem parallelen Design war die Überprüfung des Behandlungsergebnisses bei parodontalen Furkationsdefekten nach Wurzelreinigung und ,glättung bei Lappenoperationen (FDS) bei Zigarettenrauchern und Nichtrauchern. Material und Methoden: Nach der initialen Therapie wurden 31 systemisch gesunde Personen mit moderater bis schwerer Parodontitis, die mindestens einen Klasse I oder Klasse II Furkationsdefekt aufwiesen, ausgesucht. 19 Patienten (mittleres Alter 40,3 Jahre, 15 Männer) waren Raucher (,10 Zigaretten/Tag), 12 Patienten (mittleres Alter 44,8 Jahre, 3 Männer) waren Nichtraucher. Der Plaqueindex (FMPS) und die Provokationsblutung (FMBS) im gesamten Mund, die Sondierungstiefen (PPD), die vertikalen klinischen Befestigungsniveaus (v-CAL) und die horizontalen klinischen Befestigungsniveaus (h-CAL) wurden unmittelbar vor und 6 Monate nach der Operation erhoben. Ergebnisse: Insgesamt wurde ein statistisch signifikanter v-CAL Gewinn bei Rauchern (1,0±1,3 mm) und Nichtrauchern (1,3±1,1 mm) beobachtet, die Differenz wischen den Gruppen war statistisch signifikant (p=0,0003). Bei den approximalen Furkationsdefekten betrug der v-CAL Gewinn bei Nichtrauchern 2,3±0,7 mm verglichen zu den Rauchern mit 1,0±1,1 mm (p=0,0013). 6 Monate post operationem zeigten die Nichtraucher einen größeren h-CAL Gewinn (1,3±1,1 mm) verglichen mit den Rauchern (0,6±1,0 mm) mit einer statistischen Signifikanz zwischen den Gruppen (p=0,0089). Dieser Trend wurde sowohl bei den fazialen/lingualen Defekten (1,4±1,0 mm vs. 0,8±0,8 mm) und bei den approximalen Furkationsdefekten (1,2 v 1,3 mm vs. 0,5±1,2 mm) bestätigt. Das Verhältnis von Klasse II Furkationen, die post operationem eine Verbesserung zu Klasse I Furkationsdefekten zeigten, war bei Rauchern 27,6 % und 38,5 % bei Nichtrauchern. Nach 6 Monaten zeigten 3,4 % der Klasse I Furkationsdefekte bei Rauchern einen kompletten Verschluss verglichen mit 27,8 % bei Nichtrauchern. Zusammenfassung: Die Ergebnisse der vorliegenden Studie zeigten, dass 1) FDS eine klinische und statistisch signifikante PPD Reduktion, einen v-CAL Gewinn und h-CAL Gewinn bei Klasse I/II Molaren Furkationsdefekten erbringt; 2) Zigarettenraucher weniger gute Heilungsergebnisse nach Operationen sowohl bei v-CAL als auch bei h-CAL zeigten. Résumé Objectifs: cette étude clinique contrôlée en parallèle se proposait d'évaluer l'issue du trai-tement des lésions des furcations par un lam-beau de débridement (FDS) chez des fumeurs de cigarette par rapport à des non-fumeurs. Matériel et méthodes: Après un traitement initial, 31 sujets en bonne santé atteints de parodontite modérée à avancée et présentant au moins une lésion inter-radiculaire de classe I ou II sur une molaire, furent sélectionnés. 19 patients (d'âge moyen: 40.3 ans, 15 hommes) étaient fumeurs (,10 cigarettes/jour), 12 patients (d'âge moyen: 44.8 ans, 3 hommes) étaient non-fumeurs. Le score de plaque de toute la bouche (FMPS) et le score de saignement (FMBS), la profondeur de poche au sondage (PPD), le niveau clinique d'attache vertical (v-CAL), et horizontal (h-CAL) furent estimés immédiatement avant et 6 mois après la chirurgie. Résultats: D'une façon générale, un gain de v-CAL statistiquement significatif gain était observé chez les fumeurs (1.0±1.3 mm) et chez les non-fumeurs (1.3±1.1 mm), la différence entre les groupes étant statistiquement significative (p=0.0003). Pour les lésions des furcations proximales, le gain de v-CAL atteignait 2.3±0.7 mm chez les non-fumeurs et seulement 1.0±1.1 mm chez les fumeurs (p=0.0013). 6 mois après la chirurgie, les non-fumeurs présentaient un gain de h-CAL gain plus important (1.3±1.1 mm) que les fumeurs(0.6±1.0 mm), avec une différence statistiquement significative entre les groupes (p=0.0089). Cette tendance était confirmée à la fois sur les lésions des furcations vestibulo-linguales (1.4±1.0 mm vs 0.8±0.8 mm) et proximales (1.2±1.3 mm vs 0.5±1.2 mm). La proportion de furcations de Classe II s'améliorant après chirurgie en Classe I était de 27.6% chez les fumeurs et 38.5% chez les non-fumeurs. Après 6 mois, 3.4% des furcations initialement de Classe I étaient complètement fermées contre 27.8% chez les non-fumeurs. Conclusions: Les résultats de cette étude indiquent que: 1) FDS produit une réduction cliniquement et statistiquement significative de PPD, un gain de v-CAL et de h-CAL gain sur les lésions de furcations molaires de Classe I/II; 2) Les fumeurs de cigarette ont une cicatrisation moins favorable après chirurgie en terme de gain de v-CAL et de h-CAL. [source] The Amplatzer Duct Occluder II: A New Device for Percutaneous Ductus Arteriosus ClosureJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2009ZAKHIA SALIBA M.D. Objective: Study the new Amplatzer Duct Occluder II (ADO II). Limitations were encountered with the preexisting devices in nonconical ducts, large ducts, or in small infants. These include failure, residual shunts, protrusion, migration, and vascular damage. Methods: Between June 2008 and March 2009, 20 consecutive patients were enrolled. In cases where different devices were applicable, we favored the use of the ADO II to maximize our experience with this device and prove its superiority. No coils were required in these 20 patients. Results: There were 15 females and 5 males (median age 2 years). ADO II group (n = 16): Immediate complete closure in 75% of the patients, rising to 93.7% at 24 hours. A residual shunt persisted at 3 months in one child. Aortic narrowing from device protrusion was noted in two type E ducts, without any significant gradient, however. ADO I group (n = 4): In two adolescents and in one adult patient, the duct was successfully closed. In a 2-year-old patient with a 6.6 mm type B duct, the ADO I totally obstructed the aortic flow and was retrieved before releasing. The child was sent for surgery. Conclusion: Even though we did not compare the ADO II to other devices, we feel that it has the capacity to substitute most of the coils, and some of the original ADO I indications. Arterial access was sufficient in most patients, but venous delivery is advised in small infants with large or long ducts, to avoid aortic protrusion and residual shunts. [source] Transcatheter Closure of Patent Foramen Ovale in Patients with Paradoxical Embolism.JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2008Follow-up Results after Implantation of the Starflex® Occluder Device with Conjunctive Intensified Anticoagulation Regimen, Procedural Background:Prevalence of patent foramen ovale (PFO) is higher in patients with paradoxical embolism and associated with increased risk for recurrent thromboembolic events. By percutaneous closure of PFO, surgical closure or permanent oral anticoagulation can be avoided. So far, published series included different occluder systems and various indications and regimens of postprocedural anticoagulation. The aim of the present study was to evaluate the short- and long-term results after implantation of the Starflex® occluder in patients with PFO using an intensified anticoagulation regimen. Methods and Results:154 patients with PFO (94 men; age: 44 ± 13 years) and >1 thromboembolic event were included. Other causes for embolism were excluded. PFO closure was successful in 147 patients (95.5%). All patients were treated with phenprocoumon (INR 2.5) and aspirin (100 mg/die) for 6 months. Transesophageal echocardiography (TEE) was repeated at 6 months. Mean clinical follow-up period was 26 ± 18 months. After 6 months, five patients had a significant residual shunt, and five patients had suspected thrombus formation on the occluder. In three of these five patients, the occluder was surgically removed and foreign body reaction was noted. During follow-up, nine patients suffered from neurological events (two strokes, seven transient ischemic attacks [TIA]), though complete closure of the PFO was documented by TEE. Two patients died during follow-up; three patients had bleeding complications. Conclusion:Percutaneous closure of PFO in symptomatic patients by Starflex® occluder represents an effective therapy with a low incidence of periinterventional complications and recurrent thromboembolism. However, thrombus formation at the occluder system may occur in some patients despite an aggressive anticoagulation regimen. [source] Patent Ductus Arteriosus ClosureJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2006RICHARD A. KRASUSKI M.D. Patent ductus arteriosus is a common clinical lesion which increases the risk of endocarditis and may lead to heart failure and pulmonary hypertension. Devices and techniques have advanced to the point that in most patients percutaneous closure should be the procedure of choice. Devices are best selected by fully examining the anatomy of the defect. In general coils are best suited for smaller defects and the Amplatzer Duct Occluder excels in moderate to large defects. Follow-up should include echocardiography to ensure complete closure. [source] Single-Center Experience with the HelexÔ Septal Occluder for Closure of Atrial Septal Defects in ChildrenJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2003ROBERT N. VINCENT M.D. Catheter closure of atrial septal defects (ASDs) is an accepted procedure among pediatric cardiologists. We report our early experience with the newest of these devices in clinical trials in the United States. Between April and October 2001, 14 patients were enrolled in an FDA phase II multicenter trial comparing the results of ASD closure using the HELEXÔ Septal Occluder to a surgical control group. Of the 14 patients, devices were placed and left in 13, one being removed for an excessive residual leak despite placing the largest device available. Of the remaining 13 patients, all patients had successful closure of their defects. An average of 1.8 devices/patient were deployed, reflecting the learning curve for this new device and new delivery style. Six devices were replaced because of excessive residual leaks, three for premature lock release, and two for improper seating of the device. There were no procedural complications, however, one patient required device removal 4 months postimplant for possible allergic reaction to nickel. The same patient had removal of stainless steel sternal wires for the same reason. At the 6-month follow-up, 11 of 13 patients had complete closure of the ASD, the other two having small, hemodynamically insignificant left to right shunts. In one of these patients, there was complete closure at the 12-month follow-up, whereas the other patient awaits the 1-year evaluation. Early experience at our institution has demonstrated the ease of use of this device, its complete retrievability, and excellent closure of small to moderate ASDs in children. (J Interven Cardiol 2003;16:79,82) [source] Convergence in the macroscopic anatomy of the reticulum in wild ruminant species of different feeding types and a new resulting hypothesis on reticular functionJOURNAL OF ZOOLOGY, Issue 1 2010M. Clauss Abstract The reticulum is the second part of the ruminant forestomach, located between the rumen and the omasum and characterized by honeycomb-like internal mucosa. With its fluid contents, it plays a decisive role in particle separation. Differences among species have been linked to their feeding style. We investigated whether reticulum size (absolute and in relation to rumen size) and size of the crests that form the mucosal honeycomb pattern differ among over 60 ruminant species of various body sizes and feeding type, controlling for phylogeny. Linear dimensions generally scaled allometrically, that is to body mass0.33. With or without controlling for phylogeny, species that ingest a higher proportion of grass in their natural diet had both significantly larger (higher) rumens and higher reticular mucosa crests, but neither reticulum height nor reticulum width varied with feeding type. The height of the reticular mucosa crests represents a dietary adaptation in ruminants. We suggest that the reticular honeycomb structures do not separate particles by acting as traps (neither for small nor for large particles), but that the structures reduce the lumen of the reticulum during contractions , at varying degrees of completeness in the different feeding types. In browsing species with rumen contents that may be less fluid and more viscous than those of the reticulum, incomplete closure of the lumen may allow the reticulum to retain the fluid necessary for particle separation. In grazing species, whose rumen contents are more stratified with a larger distinct fluid pool, a more complete closure of the reticular lumen due to higher crests may be beneficial as the reticulum can quickly re-fill with fluid rumen contents that contain pre-sorted particles. [source] Oral tacrolimus long-term therapy in patients with Crohn's disease and steroid resistanceALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2001E. Ierardi To report the results of a prospective, open-label, uncontrolled study in 13 patients affected by Crohn's disease with resistance to steroids. Methods: The patients were treated long-term with oral tacrolimus, aiming to both resolve acute attacks and maintain remission. Tacrolimus was administered at the dose of 0.1,0.2 mg.day/kg and adjusted in order to achieve levels of 5,10 ng/mL; only mesalazine was continued concomitantly. Steroids and total parenteral nutrition were tapered when appropriate. Results: Median treatment was 27.3 months. Only one patient dropped out due to adverse events. Crohn's disease activity index score significantly decreased after 6 months in 11 patients; for 1 year in nine of them, and 7 years in two of them. The inflammatory bowel disease life-quality questionnaire score significantly increased over the same periods. A marked drop in hospitalizations was recorded. In three out of six patients complete closure of fistulas occurred. Tacrolimus allowed total parenteral nutrition to be withdrawn in three out of five patients. Supplementation with low-dose steroids was required in five patients. Two patients underwent surgery. Conclusions: Tacrolimus therapy appears to be associated with both short- and long-term benefits, and may represent a therapeutic option in Crohn's disease when conventional therapies fail. This study encourages its use in controlled trials. [source] Dimensional Stability of the Free Fascia Grafts: An Animal Experiment,THE LARYNGOSCOPE, Issue 4 2002Shabbir Indorewala MS (ENT) Abstract Objectives/Hypothesis It appears that autologous free fascia grafts (fascia lata and temporal fascia) change their dimensions during the vital first 5 days of healing. Poor dimensional stability of these grafts can be an important reason for failure of complete closure of tympanic membrane perforations in tympanoplasty operations. There has been no study regarding this dimensional instability. Study Design Prospectively dimensional instability of the free fascia grafts was studied in 14 mongrel dogs. Methods Fourteen healthy Mongrel dogs were operated on twice. During the first surgery, fascia lata and temporal fascia grafts of measured dimensions (length, breadth, and thickness) were implanted in the subcutaneous pockets on the thoracoabdominal wall of the same dog (autograft). Five dogs were operated on again after 2 days, and 7 dogs were operated on again after 5 days to harvest the implanted grafts. The dimensions of the harvested grafts were noted. Changes with respect to their implant dimensions after 2 days and after 5 days were calculated. Results It was found that free fascia lata exhibits significantly superior dimensional stability when compared with free temporal fascia during the early healing phase, before graft integration has occurred. Shrinking and thickening of temporal fascia are greaterand are also most unpredictable. Conclusions Poor dimensional stability of temporal fascia may compromise a well-sealed perforation at the time of surgery, and it may reopen by the 5th day. This must be one of the causes of failure of tympanoplasty, which needs to be studied further. [source] Substrate analogs induce an intermediate conformational change in Toxoplasma gondii adenosine kinaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2007Yan Zhang Adenosine kinase (AK) is a key enzyme in purine metabolism in the ubiquitous intracellular parasite Toxoplasma gondii and is a potential chemotherapeutic target for the treatment of T. gondii infections. To better understand the structure,activity relationship of 6-substituted purine ribosides, the structures of the T. gondii AK,N6,N6 -dimethyladenosine (DMA) complex, the AK,DMA,AMP-PCP complex, the AK,6-methyl mercaptopurine riboside (MMPR) complex and the AK,MMPR,AMP-PCP complex were determined to 1.35, 1.35, 1.75 and 1.75,Å resolution, respectively. These structures reveal a conformation intermediate between open and closed, with a small lid-domain rotation of 12°. Residues Gly143- X - X -Gly146 undergo torsional changes upon substrate binding, which together with a Gly68-Gly69 switch induces a hinge bending of the lid domain. The intermediate conformation suggests that ATP binding is independent of adenosine binding. Orienting the ,-phosphate group of ATP into the optimal catalytic position may be the last step before the onset of chemical catalysis and may require the translocation of Arg136 following the complete closure of the lid domain. 6-Substituted purine-nucleoside analogs are accommodated in a hydrophobic cavity. Modification at the N6 or C6 position of the nucleoside would affect the interactions with the surrounding residues and the binding affinity. [source] Closure of ostium secundum atrial septum defect with the Atriasept occluder: Early European experience,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 7 2010Valérie Steiger Stolt MD Abstract Objectives: This multicentre study sought to report the safety and efficacy of the ATRIASEPT septal occluder to repair atrial septal defect (ASD). Background: The ATRIASEPT is a low profile, flexible, double disk occluder with centering system specifically designed for closure of ostium secundum ASD. Method: Patients were enrolled from four participating European sites and followed up for 12 months post procedure. Outcomes were evaluated, including closure success and incidence of adverse events. Results: Seventy-six patients received the ATRIASEPT device. Mean size of the defect was 15 ± 4 mm. Closure success was observed in 69 patients (89%) at the end of the procedure. Sixty-four patients had a six-month follow up with a complete closure by 58 patients (90%). Minor adverse events occurred in two patients. Significant functional improvement was reported by all symptomatic patients. Conclusion: Percutaneous closure of ASD ostium secundum type defects with the ATRIASEPT is safe and effective with high success rate and excellent mid-term outcome. © 2010 Wiley-Liss, Inc. [source] Transcatheter closure of perimembranous ventricular septal defects using the amplatzer membranous VSD occluder: Immediate and midterm results of an international registryCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2006Ralf Holzer MD Abstract Objective: To report the immediate and midterm results of transcatheter closure of perimembranous ventricular septal defect (PmVSD) using the Amplatzer membranous VSD occluder (AMVSD). Methods: Between April 2002 and August 2004, 100 patients underwent an attempt of percutaneous device closure of PmVSD using the AMVSD in 24 international centers. The median age was 9.0 years (0.7,58 years) and the median weight was 27.5 kg (7,121 kg). Results: A device was successfully deployed in 93/100 (93%) patients. Reasons for procedural failure were an increased gradient across the left ventricle outflow tract in one patient, aortic regurgitation in 2 patients, and inability to securely position the device in 4 patients. The median VSD size by TEE was 7.0 mm (1.5,13 mm), median device size 10 mm (4,16 mm) and median fluoroscopy time 22.1 min (8.9,96.0 min). Weight below 10 kg (P = 0.0392), inlet extension of the VSD (P = 0.0139) and aortic cusp prolapse into the VSD (P = 0.0084) were significantly associated with a lower procedural success. Patients have been followed up for a median of 182 days (1,763 days). There were no procedure-related deaths. Complications were encountered in 29/100 (29%) patients, including rhythm or conduction anomalies in 13 patients (two with complete heart block requiring permanent pacemaker implantation), new or increased aortic (9 patients) or tricuspid (9 patients) regurgitation, most of which were classified as trivial or mild. Patients with a weight below 10 kg had a significantly higher incidence of adverse events than patients with a weight above 10 kg (58.3% versus 25.0%, P = 0.0285). Immediately after device release complete closure of the defect was present in 54/93 (58.1%) patients, increasing to 46/55 (83.6%) patients at 6-months follow-up (P = 0.0012). Left ventricle end-diastolic diameter decreased from a median of 44 mm prior to device closure to a median of 39 mm at 6-months postprocedure (P = 0.0015). Conclusion: Closure of PmVSDs using the AMVSD occluder is safe and effective. However, longer follow-up period is warranted prior to the wide spread use of this device. © 2006 Wiley-Liss, Inc. [source] Morphometric evaluation of the repair of critical-size defects using demineralized bovine bone and autogenous bone grafts in rat calvariaCLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2008Rodrigo Cardoso de Oliveira Abstract Objective: To evaluate the repair of critical-size bone defects in rats treated with demineralized bovine bone (DBB) compared with autogenous bone (AB). Material and method: A bone defect of 8 mm in diameter was created in the calvaria of 50 Rattus norvegicus, treated either with DBB or AB. Sub-groups of five rats of each group were killed at 7, 14, 21, 30 and 90 days post-operatively, and the skulls were removed and processed histologically. Histological sections were stained with hematoxylin and eosin. Result: Histological analysis showed complete closure of the defects with new bone at 90 days in group AB, and substitution of the biomaterial by fibrotic connective tissue in the DBB group at 21 days. Morphometric analysis showed that DBB was rapidly absorbed at 14 days, with its volume density decreasing from 47%±0.8% at 7 days to 1.2%±0.41% at 14 days. Subsequently, volume densities of the connective tissue and neoformed bone increased from 51.1%±11.17% to 86.8%±7.92% and from 1.9%±1.13% to 12%±8.02%, respectively, for the same time interval. The volume density of AB particles did not change throughout the experimental periods, but the amount of new bone increased markedly between 7 and 90 days, from 4.5%±1.57% to 53.5%±6.42% (P<0.05). Conclusion: DBB did not provide complete repair of the defects, with significantly less new bone formation than in the AB group. [source] | |||||||||||||||||||||||||