bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arrhythmia Mechanisms in the Failing Heart
Authors: JIN HONGWEI , LYON ALEXANDER R. , AKAR FADI G. 
Published: July 2008

Background:

Heart failure (HF) claims over 200,000 lives annually in the United States alone. Approximately 50% of these deaths are sudden and unexpected, and presumably the consequence of lethal ventricular tachyarrhythmias. Electrical remodeling that occurs at the cellular and tissue network levels predisposes patients with HF to malignant arrhythmias. Our limited understanding of fundamental arrhythmia mechanisms has hampered the development of effective treatment strategies for these patients.
Methods and Conclusions:

In this review, we outline recent advances in our understanding of arrhythmia mechanisms in the failing heart, highlighting various aspects of remodeling of ion channels, calcium handling proteins, and gap junction‐related molecules. As will be discussed, these changes promote the prolongation of the action potential, the enhancement of spatio‐temporal gradients of repolarization, the formation of calcium‐mediated triggers and conduction abnormalities, all of which combine to form an electrophysiological substrate that is ripe for the genesis of lethal arrhythmias and sudden cardiac death.
Usefulness of Interatrial Conduction Time to Distinguish Between Focal Atrial Tachyarrhythmias Originating from the Superior Vena Cava and the Right Superior Pulmonary Vein
Authors: CHANG KUAN‐CHENG , CHEN JAN‐YOW , LIN YU‐CHIN , HUANG SHOEI K. STEPHEN 
Published: July 2008

Objective: Differentiation of the tachycardia originating from the superior vena cava (SVC) or the right superior pulmonary vein (RSPV) is limited by the similar surface P‐wave morphology and intraatrial activation pattern during tachycardia. We sought to find a simple method to distinguish between the two tachycardias by analyzing the interatrial conduction time. Methods: Sixteen consecutive patients consisting of 8 with SVC tachycardia and the other 8 with RSPV tachycardia were studied. The interatrial conduction time from the high right atrium (HRA) to the distal coronary sinus (DCS) and the intraatrial conduction time from the HRA to the atrial electrogram at the His bundle region (HIS) were measured during the sinus beat (SR) and during the tachycardia‐triggering ectopic atrial premature beat (APB). The differences of interatrial (Δ[HRA‐DCS]SR‐APB) and intraatrial (Δ[HRA‐HIS]SR‐APB) conduction time between SR and APB were then obtained. Results: The mean Δ[HRA‐DCS]SR‐APB was 1.0 ± 5.2 ms (95% confident interval [CI]–3.3–5.3 ms) in SVC tachycardia and 38.5 ± 8.8 ms (95% CI 31.1–45.9 ms) in RSPV tachycardia. The mean Δ[HRA‐HIS]SR‐APB was 1.5 ± 5.3 ms (95% CI –2.9–5.9 ms) in SVC tachycardia and 19.9 ± 12.0 ms (95% CI 9.9–29.9 ms) in RSPV tachycardia. The difference of Δ[HRA‐DCS]SR‐APB between SVC and RSPV tachycardias was wider than that of Δ[HRA‐HIS]SR‐APB (37.5 ± 9.3 ms vs. 18.4 ± 15.4 ms, P < 0.01). Conclusions: The wide difference of the interatrial conduction time Δ[HRA‐DCS]SR‐APB between SVC and RSPV tachycardias is a useful parameter to distinguish the two tachycardias and may avoid unnecessary atrial transseptal puncture.
Intracardiac Echo‐Guided Radiofrequency Catheter Ablation of Atrial Fibrillation in Patients with Atrial Septal Defect or Patent Foramen Ovale Repair: A Feasibility, Safety, and Efficacy Study
Authors: LAKKIREDDY DHANUNJAYA , RANGISETTY UMAMAHESH , PRASAD SUBRAMANYA , VERMA ATUL , BIRIA MAZDA , BERENBOM LOREN , PIMENTEL RHEA , EMERT MARTIN , ROSAMOND THOMAS , FAHMY TAMER , PATEL DIMPI , BIASE LUIGI DI , SCHWEIKERT ROBERT , BURKHARDT DAVID , NATALE ANDREA 
Published: July 2008

Introduction: Patients with atrial septal defect (ASD) are at higher risk for atrial fibrillation (AF) even after repair. Transseptal access in these patients is perceived to be difficult. We describe the feasibility, safety, and efficacy of pulmonary vein antral isolation (PVAI) in these patients. Method: We prospectively compared post‐ASD/patent foramen ovale (PFO) repair patients (group I, n = 45) with age‐gender‐AF type matched controls (group II, n = 45). All the patients underwent PVAI through a double transseptal puncture with a roving circular mapping catheter technique guided by intracardiac echocardiography (ICE). The short‐term (3 months) and long‐term (12 month) failure rates were assessed. Results: In group I, 23 (51%) had percutaneous closure devices and 22 (49%) had a surgical closure. There was no significant difference between group I and II in the baseline characteristics. Intracardiac echo‐guided double transseptal access was obtained in 98% of patients in group I and in 100% of patients in group II. PVAI was performed in all patients, with right atrial flutter ablation in 7 patients in group I and in 4 patients in group II. Over a mean follow‐up of 15 ± 4 months, group I had higher short‐term (18% vs 13%, P = 0.77) and long‐term recurrence (24% vs 18%, P = 0.6) than group II. There was no significant difference in the perioperative complications between the two groups. Echocardiography at 3 months showed interatrial communication in 2 patients in group I and 1 patient in group II, which resolved at 12 months. Conclusion: Percutaneous AF ablation using double transseptal access is feasible, safe, and efficacious in patients with ASD and PFO repairs.
Benefit of Primary Prevention Implantable Cardioverter‐Defibrillators in the Setting of Chronic Kidney Disease: A Decision Model Analysis
Authors: AMIN MITESH S. , FOX AARON D. , KALAHASTY GAUTHAM , SHEPARD RICHARD K. , WOOD MARK A. , ELLENBOGEN KENNETH A. 
Published: July 2008

Introduction: Primary prevention ICD trials have excluded patients with CKD. Comorbidities and lower life expectancy in patients with CKD make the benefit of primary prevention ICD implantation uncertain. Methods: A decision analysis model was devised to evaluate the risks and benefits of implantable cardioverter‐defibrillators (ICD) implantation in patients with chronic kidney disease (CKD) who meet current criteria for a primary prevention ICD. Published data capturing event rates, infection risks, and overall survival in CKD patients with and without ICDs were utilized. Variables included patient's age, GFR and stage of CKD, probability of sudden cardiac death (SCD), and device implantation mortality. Results: The benefit of an ICD for primary prevention of SCD in patients with CKD depends primarily on the patient's age and stage of kidney disease. With stages 1 and 2 CKD, ICD implantation reduces mortality. However, in patients with more advanced stages of CKD, the benefit is less significant and age‐dependent. This is attributed to patients with advanced CKD having a higher procedural risk and decreased life expectancy. With average procedural mortality, ICD implantation is favored at ages <80 for stage 3, ages <75 for stage 4, and ages <65 for stage 5. As procedural mortality rates increase, age thresholds for ICD implantation decrease. Conclusions: Our model shows that benefit from primary prevention ICD implantation is determined by the patient's age and stage of kidney disease. While there is limited impact with lower stages of CKD, careful consideration of ICD implantation is suggested for older patients with more advanced stages of kidney disease.
Impact of a Patent Foramen Ovale on Paroxysmal Atrial Fibrillation Ablation
Authors: KNECHT SÉBASTIEN , WRIGHT MATTHEW , LELLOUCHE NICOLAS , NAULT ISABELLE , MATSUO SEIICHIRO , O'NEILL MARK D. , LOMAS OLIVER , DEPLAGNE ANTOINE , BORDACHAR PIERRE , SACHER FREDERIC , DERVAL NICOLAS , HOCINI MÉLÈZE , JAÏS PIERRE , CLÉMENTY JACQUES , HAÏSSAGUERRE MICHEL 
Published: July 2008

Introduction: A patent foramen ovale (PFO) is located at the anterior and superior part of the anatomical interatrial septum, the area that is targeted during transseptal puncture. This study sought to investigate the impact of accessing the left atrium via a PFO on paroxysmal AF ablation. Methods: From March 2004, 203 patients (55 ± 11 years) underwent catheter ablation for paroxysmal AF (80 ± 71 months), with the endpoint being electrical isolation of all pulmonary veins (PV) and AF noninducibility. The presence of a PFO was determined by both transesophageal echocardiography and catheter probing. Procedural difficulty was evaluated by radiofrequency (RF), procedural, and fluoroscopic durations. Clinical follow‐up was also investigated. Results: A PFO was detected in 27 patients (13%) by transesophageal echocardiography and in 22 additional patients (total 49 patients, 24%), by catheter probing (P < 0.001). A PFO was associated with longer total RF applications (57 ± 19 vs 51 ± 18 min, P = 0.04) and RF applications to isolate the PVs (42 ± 16 vs 35 ± 12 min, P = 0.001). Procedural and fluoroscopic times were unaffected. Seventy‐three patients (36%) required a second procedure; there was no difference in the number of PV reconnections (1.3 vs 1.8 veins, P = NS). After a mean follow‐up of 19 ± 9 months, 194/203 patients (96%) were free of AF, with no difference in patients in whom a PFO had been used. Conclusion: Although isolation of PVs is longer, overall procedural duration and success is not affected when using a PFO compared with a transseptal puncture. The presence of a PFO is underestimated by transesophageal echocardiography with brachial injection when compared with catheter probing.
Genotypic characterization of Porphyromonas gingivalis isolated from subgingival plaque and blood sample in positive bacteremia subjects with periodontitis
Authors: Pérez‐Chaparro P. Juliana , Gracieux Patrice , Lafaurie Gloria Inés , Donnio Pierre‐Yves , Bonnaure‐Mallet Martine 
Published: July 2008

AbstractAim: The objective of this study was to investigate clonal relationship among Porphyromonas gingivalis isolated from subgingival plaque and blood samples in positive transient bacteremia subjects with periodontitis.Material and Methods: Unrelated patients with general chronic periodontitis or general aggressive periodontitis requiring scaling and root planing (SRP) were included in the study. Genotyping of each isolate was performed using pulsed field gel electrophoresis technique. Genetic relatedness of strains isolated within an individual or between different patients was determined by dendogram analysis.Results: Following SRP, from 16 patients, seven patients showed positive P. gingivalis bacteremia and nine were negative. Thirty‐two strains were isolated from subgingival plaque and blood samples before and during induced transient bacteremia. The majority of the patients harboured one clonal type. Two patients showed different clones in plaque and blood samples suggesting that more than one clone can be found in subgingival plaque. P. gingivalis isolates from periodontitis patients after transient bacteremia following SRP, revealed a high heterogeneity among isolates.Conclusion: In 6/16 subjects the same P. gingivalis isolate was found in the blood and in oral cavity. P. gingivalis heterogeneity suggests no association of a unique clonal type with transient bacteremia.
Tapered toothbrush filaments in relation to gingival abrasion, removal of plaque and treatment of gingivitis
Authors: Versteeg PA , Piscaer M , Rosema NAM , Timmerman MF , Van der Velden U , Van der Weijden GA 
Published: July 2008

Abstract:  Objectives:  To compare a tapered filament toothbrush (TFTB) to a control toothbrush (ADA) in their potential to cause gingival abrasion and improve the gingival condition following a period of experimental gingivitis.Methods:  Thirty‐two subjects refrained from brushing mandibular teeth for 21 days. During a subsequent 4‐week treatment phase, the left or right side of the mouth was brushed with either the TFTB or ADA as randomly allocated. Gingival abrasion, plaque and gingival bleeding were assessed.Results:  During the treatment phase gingival abrasion showed a trend to be lower with the TFTB than the ADA, which was significant at the 2‐week assessment. The mean plaque scores changed from 2.98 (day 21) to 1.59 for the TFTB and from 3.00 (day 21) to 1.31 for the ADA. The mean bleeding scores changed from 1.86 (day 21) to 1.35 for the TFTB and from 1.85 (day 21) to 1.20 for the ADA. Plaque and bleeding scores were significantly lower with the ADA.Conclusions:  Both toothbrushes improved gingival health and effectively removed plaque. Although there was a tendency towards fewer sites with gingival abrasion with the TFTB brush, it was less effective than the ADA in the removal of plaque biofilm and reduction of bleeding. Subjects considered the TFTB to be more pleasant to use.
Microbiology and Cytokine Levels Around Healthy Dental Implants and Teeth
Authors: Nowzari Hessam , Botero Javier Enrique , DeGiacomo Marina , Villacres Maria C. , Rich Sandra K. 
Published: July 2008

ABSTRACTBackground: Elicitation of the relationship of periodontopathogens and pro‐inflammatory cytokines to bone resorption and formation is significant to a growing body of research known as osteoimmunology. It is essential that clinically healthy peri‐implant and periodontal sites are studied to contribute comparison data for investigations that are addressing diseased sites.Purpose: The purpose of this study was to describe levels of selected pro‐inflammatory cytokines in clinically healthy peri‐implant and periodontal sites, and to examine whether cytokine levels may be related to specific bacterial/viral pathogens.Materials and Methods: Eleven subjects (mean age 56.2 ± 10) participated in the study. Subgingival microbial samples were cultured for periodontopathic bacteria. Gingival crevicular fluid samples were analyzed by nested polymerase chain reaction for Cytomegalovirus (HCMV) and were tested for the quantification of Interleukin (IL)‐8, IL‐1β, IL‐6, IL‐10, Tumor Necrosis Factor (TNF)‐α, and IL‐12p70 using flow cytometry (FACS). Findings for microbiota composition and cytokine levels were compared between implants and teeth (chi square, Kruskall–Wallis, Mann–Whitney; p ≤ .05).Results: Both the frequency (%) and levels (%) of periodontopathic bacteria were higher around teeth than implants. The concentration (picogram per milliliter) of cytokines was more prominent around implants than teeth, reaching nearly twofold differences in some instances. Cytokine levels were higher when the sites analyzed were positive for any bacteria tested. HCMV was not detected.Conclusions: Pro‐inflammatory cytokine production was unrelated to heavy bacterial challenge. Nevertheless, when periodontopathic bacteria were detected by culture, cytokine levels were increased around both implants and teeth. Studies are needed to investigate the pro‐inflammatory cytokines (especially IL‐1β and TNF‐α) produced in spite of minimal bacterial accumulation.
A Conservative Approach for Treating Young Adult Patients with Porcelain Laminate Veneers
Authors: CHEN YEN‐WEI , RAIGRODSKI ARIEL J. 
Published: July 2008

ABSTRACTControversy persists regarding the treatment planning criteria for young adult patients in need of esthetic restorations. The trend of conservative treatment modalities continues to become widely acknowledged. One of the conservative treatment modalities is porcelain laminate veneers (PLVs). PLVs not only provide suitable esthetics but also reliable functional strength. This article presents two anterior esthetic cases to demonstrate a conservative treatment planning approach and its application as a nontraditional solution for young adult patients. It is recommended that a conservative approach be used wherever possible as an alternative to treatment options that may aggressively sacrifice tooth structure as well as the health of the supporting tissues.CLINICAL SIGNIFICANCEBy using a conservative approach to treatment with porcelain veneers, long‐lasting, esthetic, and functional results may be achieved. Sacrificing as little tooth structure as possible and conserving the supporting tissues will facilitate prospective treatments for young adult patients.
Effect of Curing Lights and Bleaching Agents on Physical Properties of a Hybrid Composite Resin
Authors: LIMA DÉBORA ALVES NUNES LEITE , DE ALEXANDRE RODRIGO SVERSUT , MARTINS ANA CLÁUDIA MORAES , AGUIAR FLÁVIO HENRIQUE BAGGIO , AMBROSANO GLÁUCIA MARIA BOVI , LOVADINO JOSÉ ROBERTO 
Published: July 2008

ABSTRACTThe aim of this in vitro study was to evaluate the microhardness (MH) and diametral tensile strength (DTS) of a minifill hybrid composite (Filtek Z250, 3M ESPE), polymerized with halogen lamp or second generation light‐emitting diode (LED), submitted to different bleaching agents. Composite resin specimens were randomly polymerized according to experimental groups (halogen, 550 mW/cm2/20 seconds; LED, 550 mW/cm2/25 seconds) and subdivided into three subgroups (N = 8): A, without bleaching (control); H, 35% hydrogen peroxide; and C, 16% carbamide peroxide. After that, the MH test and DTS test were performed. Two‐way analysis of variance (whitening × light) and Tukey's tests (α = 5%) were performed. For DTS, there were no statistical differences among the bleaching agents and the control group; however, the halogen group presented statistically lower DTS (p < 0.05) than the LED group. For the MH test, the carbamide peroxide group presented statistically lower MH means (p < 0.05) than the control groups, and there were no statistical differences among the light‐curing units. Sixteen percent carbamide peroxide reduced the MH of the hybrid composite tested. The second generation LED presented a performance similar to or better than the halogen lamp for hardness and DTS, respectively.CLINICAL SIGNIFICANCERepolishing of minifill hybrid composite is suggested, as the alteration caused after the contact with 16% carbamide peroxide was limited to the material surface. The second generation light‐emitting diode is a good option for a curing light device when the polymerization initiator of composite resin is camphorquinone.
Mitochondrial diversity of native pigs in the mainland South and South‐east Asian countries and its relationships between local wild boars
Authors: TANAKA Kazuaki , IWAKI Yoshiatsu , TAKIZAWA Tatsuya , DORJI Tashi , TSHERING Gyem , KUROSAWA Yaetsu , MAEDA Yoshizane , MANNEN Hideyuki , NOMURA Koh , DANG Vu‐Binh , CHHUM‐PHITH Loan , BOUAHOM Bounthong , YAMAMOTO Yoshio , DAING Than , NAMIKAWA Takao 
Published: July 2008

ABSTRACTIn this study, we analyzed DNA sequence of mitochondrial DNA (mtDNA) control regions on the 130 native domestic pigs and eight wild boars in the mainland South and South‐east Asian countries including Bhutan, Cambodia, Laos, Myanmar, and Vietnam. Forty‐four haplotypes were found in the 138 individuals, 41 were in the domestic and four were in wild boars. Only one haplotype was shared by domestic and wild population in Bhutan. In other cases, mtDNA of wild boars did not show close affinity to that of the domestic pigs in the same location, indicating that the native domestic pigs in these countries did not originate in the present habitat. Phylogenetic analyzes of mtDNA haplotypes recapitulated several major clusters identified in other studies, but 11 haplotypes were grouped in a new cluster we named MTSEA. In most cases, more than one lineage group were present in a sampling station, indicating that the present indigenous domestic pigs may have multiple origins. The MTSEA haplotypes were present in relatively high frequencies in domestic pigs in the mountainous area of mainland South‐east Asia (Cambodia and Laos), with a few found in Myanmar and Bhutan. The distributions of MTSEA haplotypes are in great conformity with the distribution of present‐day Mon‐Khmer language and indicated the existence of yet another independent domestication. The D2 haplotypes that distribute high frequency (almost 100%) throughout the Chinese breeds were dominant in Bhutan, Myanmar, and Vietnam. These results suggest an existence of human‐mediated dispersal of domestic pigs from north to the south during the historical expansion of Sino‐Tibetan and Tai peoples. The D3 haplotypes previously reported in north India were found in sympatric domestic and wild pigs in Bhutan. The D3 haplotype is an important proof of independent domestication event and/or great gene flow between wild and domestic pigs in the foot of Himalaya.
The effects of protein sources supplemented with urea‐treated potato pulp (PP) silage and feeding levels of the PP silage‐based concentrate on feed intake, digestibility and ruminal fermentation in beef steers
Authors: SUGIMOTO Masahito , KANAMOTO Masayo , CHIBA Takuya , HIDARI Hisashi , KIDA Katsuya , SAITO Waka , OOI Motoki , SATO Yukinobu , SAITO Toshiro 
Published: July 2008

ABSTRACTSix Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH3‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH3‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH3‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.