Ivabradine for controlling heart rate in permanent atrial fibrillation: A translational clinical trial.

BACKGROUND: Pharmacological options for rate control in atrial fibrillation are scarce. Ivabradine was postulated to reduce the ventricular rate in this setting. OBJECTIVES: The objectives of this study were to evaluate the mechanism of inhibition of atrioventricular conduction produced by ivabradine and to determine its efficacy and safety in atrial fibrillation. METHODS: The effects of ivabradine on atrioventricular node and ventricular cells were studied by in vitro whole-cell patch-clamp experiments and mathematical simulation of human action potentials. In parallel, a multicenter, randomized, open-label, phase III clinical trial compared ivabradine with digoxin for uncontrolled permanent atrial fibrillation despite ß-blocker or calcium channel blocker treatment. RESULTS: Ivabradine 1 µM inhibited "funny" current and rapidly activating delayed rectifier potassium channel current by 28.9% and 22.8%, respectively (P < .05). The sodium channel current and L-type calcium channel current were reduced only at 10 µM. Ivabradine slowed the firing frequency of a modeled human atrioventricular node action potential by 10.6% and induced a minimal prolongation of ventricular action potential. Thirty-five (51.5%) patients were randomized to ivabradine and 33 (49.5%) to digoxin. The mean daytime heart rate decreased by 11.6 beats/min (-11.5%) in the ivabradine arm (P = .02) vs 19.6 (-20.6%) in the digoxin arm (P < .001), although the noninferiority margin of efficacy was not met (Z = -1.95; P = .97). The primary safety end point occurred in 3 patients (8.6%) on ivabradine and in 8 (24.2%) on digoxin (P = .10). CONCLUSION: Ivabradine produced a moderate rate reduction in patients with permanent atrial fibrillation. The inhibition of funny current in the atrioventricular node seems to be the main mechanism responsible for this reduction. Compared with digoxin, ivabradine was less effective, was better tolerated, and had a similar rate of serious adverse events.

Patient's learning needs and self-efficacy level after percutaneous coronary intervention: A descriptive study.

AIMS AND OBJECTIVES: Identify and compare learning needs, levels of self-efficacy and their association among inpatients and outpatients of a cardiac care unit with coronary heart disease who have undergone percutaneous coronary intervention (PCI) in a Swiss university hospital. BACKGROUND: After primary PCI, 42% of patients will suffer a recurrent ischemic cardiovascular event. Although adherence to therapeutic regimen contributes to prevent recurrence, patient adherence remains low. To strengthen it, learning needs and self-efficacy must be considered when developing effective therapeutic patient education (TPE). METHODS: Learning needs and self-efficacy were assessed using the Cardiac Patient Learning Needs Inventory (CPLNI) and the Cardiac Self-Efficacy Scale among inpatients and outpatients. The STROBE checklist for cross-sectional studies was used in reporting this study. RESULTS: Ninety-three patients participated in the study with a participation rate of 73.9%. The CPLNI median total score was significantly higher in inpatients than in outpatients: 4.23 (3.82, 4.64) versus 3.67 (3.33, 4.09), p < .001. In both units, participants declared that the most important need was related to 'anatomy and physiology' of the heart. Despite the high score, the least important need was about 'physical activity' for inpatients and 'miscellaneous information' for outpatients. No statistically significant differences were found among patients from both units regarding their self-efficacy level. CONCLUSIONS: This study shows that after PCI, patients have high learning needs and moderate levels of self-efficacy that require addressing. RELEVANCE TO CLINICAL PRACTICE: Patient's individual learning needs and self-efficacy level must be assessed prior/after PCI. A tailored TPE that considers individual learning needs and self-efficacy is recommended as a preventative measure to reduce recurrent ischemic cardiovascular events. Nurses can play a key role in this process. NO PATIENT OR PUBLIC CONTRIBUTION: For feasibility reasons, patients and public were not involved in the design, conduct, reporting or dissemination plans of this research.

Workplace Wellbeing and Quality of Life Perceived by Portuguese Nurses during the COVID-19 Pandemic: The Role of Protective Factors and Stressors.

During the COVID-19 pandemic, nurses were exposed to many stressors, which may have been associated with some mental health problems. However, most of the studies carried out on nurses' quality of life and workplace wellbeing during the COVID-19 pandemic took a pathogenic approach. Given that current scientific knowledge in this field presented too many gaps to properly inform preventive and therapeutic action, the aim of this study was to explore whether protective factors (resilience, perceived social support, and professional identification) and stressors (perceived stress and psychosocial risks in the workplace) influenced the quality of life and workplace wellbeing perceived by Portuguese nurses during the COVID-19 pandemic. Data for this cross-sectional study was collected through online self-administered questionnaires. Linear regression models were used to analyze the relationships between variables. Results showed that perceived stress, resilience and job satisfaction were associated with quality of life and workplace wellbeing among Portuguese nurses. The study's findings could serve to inform health policy and should draw the attention of nursing managers to the needs and difficulties reported by nurses, to the importance of providing them with emotional support, and to the relevance of promoting a good work environment.

Eupatorin and Salviandulin-A, with Antimicrobial and Anti-Inflammatory Effects from Salvia lavanduloides Kunth Leaves.

This study describes the antimicrobial and anti-inflammatory effects from extracts obtained from the leaves of Salvia lavanduloides. The plant material was macerated with three solvents of ascending polarity (n-hexane (Sl-Hex), ethyl acetate (Sl-AcOEt), and dichloromethane (Sl-D)). The extracts, fractions (SlD-2 and SlD-3), and isolated compounds (15,16-epoxy-10-ß-hydroxy-neo-cleroda-3,7,13(16),14-tetraene-17,12R:18,19-diolide (1), salviandulin A (2), and eupatorin (3)) were evaluated as antimicrobials against Gram-negative, Gram-positive bacteria and the fungus Candida albicans (Ca) using the minimum inhibitory concentration (MIC) and the anti-inflammatory activity induced by 13-acetate of 12-O-tetradecanoylforbol (TPA). Sl-D and Sl-AcOEt extracts, SlD-2 and SlD-3 fractions showed the highest antimicrobial activity. The isolated compounds showed good activity against Pseudomonas aeruginosa with a MIC < 2 µg/mL, while the anti-inflammatory activity, the Sl-Hex, Sl-D extracts, and SlD-3 fraction presented an inhibition of 62, 45 and 61%, respectively, while (2) 70% and (3) 72%.

Influence of seasonality on the quality of oysters from the Sado and Mira rivers.

There is a lack of knowledge about the influence of seasonality on the microbial and physicochemical quality of oysters in Sado and Mira rivers. Water, sediment, and oysters (Crassostrea angulata and Crassostrea gigas) were collected for microbiological, nutritional, and sensory analyses. The microbiological water quality and the oyster shell contamination were better during the warmer months. No seasonal effect was observed on sediments and on oyster meat. A good physicochemical and nutritional quality was also observed, with high content of polyunsaturated fatty acids, including omega-3 fatty acids, resulting in good lipid quality indices. From the sensory evaluation, both oysters' species were well scored and presented the highest scores (4) in parameters such as cream-ivory colour, sea smell, firmness and juiciness. These attributes denote the freshness degree at the time of the tasting, reflecting the quality of the bivalve.

Biología del tejido óseo y cambios morfológicos en su regeneración / Biology of bone tissue and morphological changes in its regeneration

Introducción: La regeneración ósea permite la reintegración y conformación de tejidos posteriores a la extracción o corrección de un defecto óseo. Es considerada una técnica de estimulación para la formación de hueso nuevo, donde se favorece la construcción y la preservación del coágulo con el fin de evitar la infiltración en la zona de reparación, de componentes celulares (células epiteliales y conjuntivas). Objetivos: Describir los cambios a nivel morfológico durante el proceso de regeneración ósea y mencionar distintas técnicas de preservación ósea y los factores necesarios para su realización. Presentación de caso: Paciente femenina con periodontitis apical asintomática en órganos dentarios 34 y 37, que se sometió a preservación alveolar mediante la práctica de exodoncia atraumática y regeneración ósea con xenoinjerto, colocación de membrana colágeno e implante posextractivo inmediato. Principales comentarios: La colocación inmediata de implantes posexodoncia permite una buena preservación del alveolo, siempre y cuando las condiciones clínicas del paciente así lo permitan, por ejemplo, la ausencia de procesos infecciosos agudizados como en el presente caso. La regeneración ósea, en el defecto producido por el proceso inflamatorio periapical, implicó una correcta detoxificación de la zona a través del curetaje y la aplicación de antibióticos. La respuesta inmunológica exagerada ante injertos óseos no es frecuente; sin embargo, en este caso llevó a una pérdida parcial del sustituto óseo sin comprometer el pronóstico de los implantes(AU)

Introduction: Bone regeneration allows the reintegration and conformation of tissues after the extraction or correction of a bone defect. It is considered a stimulation technique for the formation of new bone, where the construction and preservation of the clot is favored in order to avoid infiltration in the repair area of cellular components (epithelial and conjunctiva cells). Objective: Describe the changes at the morphological level during the bone regeneration process and mention different bone preservation techniques and the necessary factors for their implementation. Case presentation: Female patient with asymptomatic apical periodontitis in dental organs 34 and 37, who underwent alveolar preservation through the practice of atraumatic exodontics and bone regeneration with xenograft, collagen membrane placement and immediate post-extraction implant. Main comments: The immediate placement of post-exodontic implants allows a good preservation of the alveolus, as long as the clinical conditions of the patient allow it, for example, the absence of exacerbated infectious processes as in the present case. Bone regeneration, in the defect produced by the periapical inflammatory process, involved a correct detoxification of the area through curettage and the application of antibiotics. Exaggerated immune response to bone grafts is not common; however, in this case it led to a partial loss of bone substitute without compromising the prognosis of the implants(AU)

Diclofenac biotransformation in the enhanced biological phosphorus removal process.

Diclofenac is a pharmaceutical active compound frequently detected in wastewater and water bodies, and often reported to be persistent and difficult to biodegrade. While many previous studies have focussed on assessing diclofenac biodegradation in nitrification and denitrification processes, this study focusses on diclofenac biodegradation in the enhanced biological phosphorus removal (EBPR) process, where the efficiency of this process for diclofenac biodegradation as well as the metabolites generated are not well understood. An enrichment of Accumulibacter polyphosphate accumulating organisms (PAOs) was operated in an SBR for over 300 d, and acclimatized to 20 µg/L of diclofenac, which is in a similar range to that observed in domestic wastewater influents. The diclofenac biotransformation was monitored in four periods of stable operation and linked to the microbial community and metabolic behaviour in each period. Nitrification was observed in two of the four periods despite the addition of a nitrification inhibitor, and these periods were positively correlated with increased diclofenac biodegradation. Interestingly, in two periods with excellent phosphorus removal (>99%) and no nitrification, different levels of diclofenac biotransformation were observed. Period 2, enriched in Accumulibacter Type II achieved more significant diclofenac biotransformation (3.4 µg/gX), while period 4, enriched in Accumulibacter Type I achieved lower diclofenac biotransformation (0.4 µg/gX). In total, 23 transformation products were identified, with lower toxicity than the parent compound, enabling the elucidation of multiple metabolic pathways for diclofenac biotransformation. This study showed that PAOs can contribute to diclofenac biotransformation, yielding less toxic transformation products, and can complement the biodegradation carried out by other organisms in activated sludge, particularly nitrifiers.

Mapping Technologies for Catheter Ablation of Atrial Fibrillation Beyond Pulmonary Vein Isolation.

Catheter ablation remains the most effective and relatively minimally invasive therapy for rhythm control in patients with AF. Ablation has consistently shown a reduction of arrhythmia-related symptoms and significant improvement in patients' quality of life compared with medical treatment. The ablation strategy relies on a well-established anatomical approach of effective pulmonary vein isolation. Additional anatomical targets have been reported with the aim of increasing procedure success in complex substrates. However, larger ablated areas with uncertainty of targeting relevant regions for AF initiation or maintenance are not exempt from the potential risk of complications and pro-arrhythmia. Recent developments in mapping tools and computational methods for advanced signal processing during AF have reported novel strategies to identify atrial regions associated with AF maintenance. These novel tools - although mainly limited to research series - represent a significant step forward towards the understanding of complex patterns of propagation during AF and the potential achievement of patient-tailored AF ablation strategies for the near future.

Anatomical targets and expected outcomes of catheter-based ablation of atrial fibrillation in 2020.

Anatomical-based approaches, targeting either pulmonary vein isolation (PVI) or additional extra PV regions, represent the most commonly used ablation treatments in symptomatic patients with atrial fibrillation (AF) recurrences despite antiarrhythmic drug therapy. PVI remains the main anatomical target during catheter-based AF ablation, with the aid of new technological advances as contact force monitoring to increase safety and effective radiofrequency (RF) lesions. Nowadays, cryoballoon ablation has also achieved the same level of scientific evidence in patients with paroxysmal AF undergoing PVI. In parallel, electrical isolation of extra PV targets has progressively increased, which is associated with a steady increase in complex cases undergoing ablation. Several atrial regions as the left atrial posterior wall, the vein of Marshall, the left atrial appendage, or the coronary sinus have been described in different series as locations potentially involved in AF initiation and maintenance. Targeting these regions may be challenging using conventional point-by-point RF delivery, which has opened new opportunities for coadjuvant alternatives as balloon ablation or selective ethanol injection. Although more extensive ablation may increase intraprocedural AF termination and freedom from arrhythmias during the follow-up, some of the targets to achieve such outcomes are not exempt of potential severe complications. Here, we review and discuss current anatomical approaches and the main ablation technologies to target atrial regions associated with AF initiation and maintenance.

Mechanical Properties of the Mandible in Postmenopausal Women Under Aledronate Treatment.

AIMS: This study evaluated the mechanical properties of mandibular bone tissue retrieved from postmenopausal women under alendronate treatment. METHODS: Twenty postmenopausal women were divided into two groups: healthy postmenopausal subjects (control group) and osteoporotic subjects treated with alendronate (alendronate group). Mandibular bone samples were retrieved with a trephine bur at the time of dental implant placement and fixed in 4% formalin. Samples were processed for hard tissue histology, and the bone surface was analyzed for nanohardness measurement. Nanohardness and elastic modulus were evaluated by using a Berkovich tip with elastic modulus of 1.016x106 MPa, Poisson coefficient of 0.3, and a load of 100 mN. Each cycle was configured with a load time of 18 seconds (speed of 1 mN/second), the discharge time of 18 seconds, and a rest time of 5 seconds during indentation at a depth of 10 µm. RESULTS: The control group presented the highest values for nanohardness and elastic modulus (p less than 0.05) in relation to the osteoporotic subjects. CONCLUSIONS: Within the limitations of the study, it can be concluded that treatment with alendronate negatively influenced the mechanical properties of mandibular bone in postmenopausal women by reducing bone nanohardness and elastic modulus.

A constant postpacing interval in response to overdrive pacing with variable number of beats: An aid in the identification of entrainment for a particular pacing train during macroreentrant atrial tachycardias.

BACKGROUND: When pacing trains with a constant cycle length (CL) but increasing number of beats are introduced during a macroreentrant atrial tachycardia (MAT), the postpacing interval (PPI) is expected to increase if entrainment does not occur but could be stable if entrainment occurs. We tested the ability of PPI analysis to detect entrainment. METHODS: Synchronized pacing trains with increasing number of beats (1-20) were delivered from the coronary sinus (CS) and lateral right atrium (RA) at a CL 20 ms shorter than the MAT CL. Pacing trains were grouped in pairs differing by one-paced beat, and the ∆PPI measured. RESULTS: In an initial prospective cohort of 21 patients (48% had left atrial flutter) the mean ∆PPI was 21.3 ± 5.6 ms for pairs of pacing trains in which neither entrained the MAT and 2.8 ± 1.4 ms for those in which both entrained the MAT (P < .0001). Results were similar for common vs atypical flutter, PPI-TCL ≤30 ms vs PPI-TCL >30 ms, presence vs absence of antiarrhythmic drugs and faster vs slower MAT. When an index pacing train was compared to one with two-paced beats less, a PPI difference of <19 ms identified entrainment with 95% sensitivity and 98% specificity. In a validation cohort of 16 patients, this cut-off value resulted in sensitivity and specificity of 90% and 94%. CONCLUSIONS: A relatively constant ∆PPI in response to overdrive pacing with identical CL but different number of beats allows accurate discrimination between trains that entrained vs those which did not entrain a MAT.

A retrospective study of scorpionism in 11 domestic dogs and a cat in the urban area of Manizales, Colombia.

The present study analyzes cases of scorpionism in 11 dogs and a cat that were registered at a veterinary clinic in the city of Manizales, between 2009 and 2018. All eight cases where expert identification of the arthropod was possible, involved Centruroides gracilis (Latreille, 1804). None of the stings were lethal, though two cases were classified as severe envenomation and five moderate. The primary sign was local pain, in addition to lameness in all 10 cases that involved one of the limbs (83,3%, 10 of 12 cases). The other two cases had injuries involving the face. The established treatment was symptomatic with clinical and patient monitoring. Antivenom could not be used due to its high cost and scarcity. However, even the severest cases improved satisfactorily, and all patients were discharged without complication.

Small-Caliber Lead Failure After Generator Exchange.

INTRODUCTION AND OBJECTIVES: The Sprint Fidelis defibrillator lead (Medtronic) was recalled in 2007 due to an increased risk of failure. The generator exchange (GE) procedure has been associated with the development of Fidelis lead dysfunction. The aim of this study was to compare the rate of dysfunction between Sprint Fidelis and other defibrillator leads during the first year after GE. METHODS: A multicenter retrospective study involving patients from the UMBRELLA database who underwent GE with previous normal lead function and minimum follow-up of 1 year after the procedure was performed. The incidence of lead dysfunction was determined via remote monitoring and defined as pacing impedance > 1,500 ohm, high-voltage impedance > 100 ohm, R wave sensing under 2 mV, or the presence of VT/VF episodes classified as noise. RESULTS: A total of 531 patients were included (114 Fidelis). In the first year after GE, the total incidence of lead dysfunction was 3.6%. No significant differences were found between Fidelis and the others in survival analysis (3.5% vs. 3.6%, respectively, log-rank 0.002, P = 0.962). CONCLUSIONS: According to our results, the preventive removal/replacement of the Sprint Fidelis leads with normal function until GE is not a recommended practice since the rate of dysfunction after the procedure in this subgroup is no different compared with other defibrillator leads.

Immediate post-procedure bridging with unfractioned heparin versus low molecular weight heparin in patients undergoing radiofrequency ablation for atrial fibrillation with an interrupted oral anticoagulation strategy.

PURPOSE: Many centers perform catheter ablation for atrial fibrillation (AF) with periprocedural interruption of oral vitamin K antagonists. In this scenario, the optimal post-procedural anticoagulation strategy is still under debate. We sought to compare the incidence of major complications associated with post-procedural use of low molecular weight heparin (LMWH) versus unfractioned heparin (UFH) as a bridge to reinitiation of oral anticoagulation after an AF ablation procedure. METHODS: We retrospectively reviewed medical history data of all patients undergoing catheter ablation for AF at three Spanish referral centers between January 2009 and January 2014. A total of 702 patients were included in the analysis. We compared the incidence of major complications (a combination of major bleeding and thromboembolic events) between patients receiving UFH (291) and those receiving LMWH (411) after the procedure. RESULTS: The overall incidence of major complications was 4.1%, including five thromboembolic events (0.7%) and 24 major bleeding events (3.4%), with no significant differences in patients treated with LMWH vs. UFH (2.9 vs. 4.1%; P = NS). The presence of peripheral vascular disease emerged as the only independent predictor of major complications (adjusted odds ratio (OR) 9.1; confidence interval (CI) 95% 1.7-49.3; P < 0.01). CONCLUSIONS: Immediate post-procedural bridging with UFH or with LMWH are equally safe strategies in patients undergoing catheter ablation for AF in whom oral anticoagulation is interrupted for the procedure. Due to its greater simplicity of use, LMWH may be the preferred option. The presence of peripheral vascular disease is a potent predictor of major post-procedural complications.

Number of Beats in the Transition Zone With Fixed SA Interval during Right Ventricular Overdrive Pacing Determines Accessory Pathway Location in Orthodromic Reentrant Tachycardia.

BACKGROUND: Ventricular overdrive pacing (VOP) produces reset during the transition zone (TZ) of QRS fusion in orthodromic reentrant tachycardia (ORT) and after the TZ in atrioventricular nodal reentrant tachycardia (AVNRT), and this represents a simple diagnostic maneuver to differentiate the two tachycardia mechanisms. OBJECTIVE: The purpose of this study was to determine whether the number of beats with reset in the TZ predicts accessory pathway (AP) location in ORT. METHODS: We retrospectively reviewed 57 patients with ORT (21 left-sided AP, 20 septal AP, and 16 right-sided AP) and 20 patients with AVNRT (19 typical AVNRT and one atypical AVNRT) who underwent VOP from the right ventricular apex. We analyzed the number of beats with reset during or after the TZ, demonstrated by fixed ventricular stimulus-atrial (SA) interval during VOP. RESULTS: The overall mean tachycardia cycle length [CL] minus VOP CL was 22.6 ± 7.5 ms with no statistical difference between the groups (P = 0.480). The mean number of beats in the TZ with fixed SA interval was 2.5 ± 1.4 for the whole ORT group, 1.1 ± 0.4 for left-sided AP (range 1-2), 2.8  ±  0.9 for septal AP (range 1-5), and 4.0 ± 0.9 for right-sided AP (range 3-6) (P < 0.001). Using a cutoff >2 beats distinguished right- versus left-sided AP in all cases. CONCLUSION: Assessing the number of beats in the TZ with fixed SA interval during VOP helps to determine AP location in ORT and adds valuable information to an established simple diagnostic pacing maneuver, especially when a two-catheter simplified approach is employed.

Performance of the SA-VA Difference to Differentiate Atrioventricular Nodal Reentrant Tachycardia from Orthodromic Reentrant Tachycardia in a Large Cohort of Consecutive Patients.

BACKGROUND: The stimulus-atrial (SA) interval minus ventriculoatrial (VA) interval (SA-VA) difference represents a simple diagnostic maneuver to distinguish between atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic reentrant tachycardia (ORT) during electrophysiology study. However, its usefulness has largely been studied in selected patient subgroups. The purpose of this study was to evaluate the performance of the SA-VA difference against commonly used diagnostic maneuvers in a large cohort of consecutive patients. METHODS: Consecutive patients with inducible supraventricular tachycardia and successful entrainment through pacing trains from right ventricular apex during an electrophysiological study were included. Atrial tachycardias were excluded. The following intervals were calculated for each patient: SA-VA difference, His potential, and atrial electrogram during entrainment minus His potential and atrial electrogram during tachycardia, and the corrected return cycle. RESULTS: A total of 456 patients fulfilled the inclusion criteria, of which electrophysiological study revealed 265 typical AVNRT, 38 atypical AVNRT, and 54 and 108 ORT through a septal and free-wall accessory pathway, respectively. An SA-VA difference >99 ms identified AVNRT in all patients with sensitivity, specificity, and positive and negative predictive values of 97.7%, 96.9%, 98.3%, and 95.7%, respectively. CONCLUSIONS: This study confirms the high ability to distinguish AVNRT from ORT using the SA-VA difference, not only in selected patient subgroups, but as whole when a cut-off of >99 ms is used.

Evaluación de l mutación abcb1-1▲ en peros y sus implicaciones terapéutticas y toxicológicas / Analysis of he ccanine abcb1-1▲ mutation and its theraeutic and toxiccological implications

Se analizó la literatura científica de los últimos 10 años en las bases de datos BBCS-LILACS, Fuente Académica, IB-PsycINFO, IB-SSCI, IB-SciELO, SCOPUS y SCIRUS, estudiando las implicaciones terapéuticas de la mutación del gen ABCB1 en perros; esta mutación que consiste en la deleción de 4 pares de bases que provocan un codón de terminación prematuro, es la responsable de la ausencia de la glicoproteína P en la barrera hematoencefálica, la carencia de esta glicoproteína priva al cerebro de la protección de una bomba de eflujo frente a múltiples xenobióticos. Además, se describen los cambios farmacocinéticos y las intoxicaciones medicamentosas resultantes de esta mutación y se presenta una lista, extraída de los distintos estudios, donde se copilan algunos fármacos sustratos para la glicoproteína P y los medicamentos que pueden inhibir dicha glicoproteína, todos ellos capaces de inducir severos efectos adversos en los perros con dicha mutación.

We conducted a review of the results of the studies of the last ten years from the data bases BBCS-LILACS, IB- PsycINFO, IB-SSCI, IB.SciELO, SCOPUS and SCIRUS, about the therapeutic implications of the gene mutation ABCB1 in dogs. This mutation is responsible for the absence of the glycoprotein P in the blood-brain barrier, depriving the brain of an efflux pump to protect against various xenobiotics. Furthermore, we described the pharmacokinetic changes and drug poisoning resulting from this mutation. We also present a list of drug substrates for the glycoprotein P and the medications that can inhibit said glycoprotein, all of them capable of inducing severe side effects in dogs with the mutation.

Cavo-tricuspid isthmus radiofrequency ablation using a novel remote navigation catheter system in patients with typical atrial flutter.

AIMS: A new remote catheter system (AMIGO™ Remote Catheter System) compatible with conventional ablation catheters is now commercially available but no data about its performance in clinical use during ablation have been reported. This study evaluates the feasibility, efficacy, and safety of cavo-tricuspid isthmus (CTI) ablation with this system in patients with typical atrial flutter (AFl). METHODS AND RESULTS: Sixty patients with typical AFl underwent CTI ablation using the new remote catheter navigation system with 8 mm tip or irrigated catheters in three centres following each centre's routine practice. The endpoint was stable bidirectional CTI block. CTI ablation was successful in 98% of patients. Ablation was completed manually in one patient. The overall procedure, fluoroscopy, and radiofrequency times (median ± standard deviation, range) were 123 ± 42 (50-250), 24 ± 13 (3-82), and 10 ± 8 (1.17-43.3) min, respectively. Three patients had vascular complications not requiring surgical intervention. There were no complications related to the remote catheter manipulation system. CONCLUSION: Cavo-tricuspid isthmus ablation for typical AFl can be safely and effectively performed with the AMIGO™. The learning curve seems to be short even for physicians with limited ablation experience.

Evaluación de la citotoxicidad de la Clindamicina en cultivos de fibroblastos gingivales humanos / Evaluation of the cytotoxicity of Clindamycin in cultures of gingival human fibroblasts

Introducción: la presencia de microorganismos residuales post-preparación químico-quirúrgico de los conductos radiculares, sugiere el empleo de medicación intracanal eficaz y biológicamente compatible con los tejidos periapicales. Objetivo: comparar la citotoxicidad de medicaciones de uso intracanal en fibroblastos gingivales humanos. Métodos: estudio de tipo experimental. Con cuatro diferentes grupos: control (G1), Clorhidrato de Clindamicina 2g asociado a fosfato de dexametasona 0,32g (Clindex) vehiculado en solución alcohólica (G2), Clindex Vehiculado en polietilenoglicol 400 (G3), y NDP: paramonoclorofenol asociado a fosfato de dexametasona 0,32g vehiculado en polietilenoglicol 400 y solución salina (G4). Las células fueron estimuladas con las medicaciones por 24, 48 y 72 horas y la viabilidad celular fue evaluada usando la técnica de análisis de MTT y la lectura fue realizada en el espectrofotómetro de ELISA. Resultados: fueron analizados por medio de la actividad mitocondrial y mostraron que el G2 obtuvo los mejores resultados en los tres tiempos estudiados, seguido por el G3 y el G4. Se realizó análisis estadístico (ANOVA y complementado con la prueba de Tukey) mostraron diferencias significante a nivel de 1% G2 y G3 cuando se compararon con el G4. Conclusión: la combinación Clindamicina dexametasona independiente del vehículo presentó mayor viabilidad celular que el paramonoclorofenol asociado a fosfato de dexametasona.

Introduction: the presence of residual microorganisms after chemical-surgical preparation of root canals suggests the use of effective intracanal medication, biologically compatible with periapical tissues. Objective: compare the cytotoxicity of intracanal medications in gingival human fibroblasts. Methods: an experimental study was conducted with four different groups: control (G1), Clindamycin Hydrochloride 2g associated to dexamethasone phosphate 0.32g (Clindex) vehicled in alcoholic solution (G2), Clindex vehicled in polyethylene glycol 400 (G3), and NDP: paramonochlorophenol associated to dexamethasone phosphate 0.32g vehicled in polyethylene glycol 400 and saline solution (G4). The cells were stimulated with the medications for 24, 48 and 72 hours. Cell viability was evaluated with the technique of MTT analysis. Readings were performed in an ELISA spectrophotometer. Results: the groups were analyzed in terms of mitochondrial activity. G2 had the best results in the three times studied, followed by G3 and G4. A statistical analysis was performed (ANOVA and complemented by Tukey's test). Significant differences of 1% were found when comparing G2 and G3 with G4. Conclusion: the Clindamycin dexamethasone combination, irrespective of the vehicle, showed greater cell viability than paramonochlorophenol associated to dexamethasone phosphate.