bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrophysiologic and Antiarrhythmic Effects of the New Class III Antiarrhythmic Drug KCB-328 in Experimental Canine Atrial Flutter
Authors: Rahme Marc M. , Ungab GilAnthony , Wadhwa Manish , Al-Kandari Fawziah , Yao Biguang , Gupta Anuj , Lee Kiho , Kim Hak-Yeop , Feld Gregory K. 
Published: June 2007

Background: The electrophysiologic and antiarrhythmic effects of a new class III antiarrhythmic drug (KCB-328), a delayed rectifier potassium current (IKr) blocker with minimal reverse use-dependent effect on atrial repolarization, were evaluated in the canine night atrial crush-injury model of atrial flutter (AFL). Methods: Ten anesthetized, open-chest dogs, were studied after right atrial crush-injury. Atrial effective refractory period (ERP), conduction velocity (CV), wavelength, and dispersion of refractoriness were determined during programmed stimulation (S1S2 at SISI = 200, 300, 400, and 500 msec) at four sites via a mapping plaque sutured on the right atrial free wall. Right and left ventricular ERP were similarly measured at single sites. Electrophysiological parameters were determined at baseline and following sequential cumulative doses of KCB-328 (10, 30, 100. and 300,ug/kg). Results: Sustained AFL was inducible in 7/10 dogs by rapid pacing following baseline electrophysiologic measurements. KCB-328 significantly prolonged sinus cycle length, but had no effect on PR interval, and prolonged QTc only at the highest dose level. KCB-328 significantly prolonged atrial ERP and wavelength and ventricular ERP, and significantly reduced dispersion of atrial refractoriness. KCB-328 significantly prolonged AFL cycle length, and increasing doses progressively terminated sustained AFL and prevented its reinduction by pacing. No adverse hemodynamic or ventricular proarrhythmic effects were observed. Conclusions: The electrophysiologic profile of KCB-328 in this canine model of AFL, particularly its lack of reverse use-dependent effect on atrial refractoriness, suggests that it may have significant antiarrhythmic potential in treatment of atrial arrhythmias.
Efficacy of Amiodarone for the Termination of Chronic Atrial Fibrillation and Maintenance of Normal Sinus Rhythm: A Prospective, Multicenter, Randomized, Controlled, Double Blind Trial
Authors: Galperin Jorge , Elizari Marcelo V. , Chiale Pablo A. , Molina Remberto Torres , Ledesma Rauil , Scapin Angel O. , Blanco Manuel Vaizquez 
Published: June 2007

Objective: We sought to assess the efficacy and safety of amiodarone for restoration and maintenance of sinus rhythm in patients with chronic atrial fibrillation in a prospective, randomized, double blind trial. Background: Restoration and preservation of sinus rhythm is difficult in patients with chronic atrial fibrillation. The efficacy of oral amiodarone has not been conclusively established. Methods: Ninety-five patients with chronic atrial fibrillation, lasting an average of 35.6 months, were randomized to either amiodarone (600 mg/d) (47 patients) or placebo (48 patients) during four weeks. Nonresponders underwent electric cardioversion, and those who reverted continued with amiodarone (200 mg/d) or placebo. End-points were successful cardioversion and sinus rhythm maintenance. Results: Sixteen patients (34.04%) in the amiodarone group reverted within 27.28 ± 8.85 days in comparison with 0% in the placebo group (P < 0.000009). The conversion rate rose to 51.72% in patients with chronic atrial fibrillation lasting less than 12 months. Twenty-eight patients in the amiodarone group and 39 in the placebo group underwent electric cardioversion, which was successful in 19 patients (67.8%) of the amiodarone group and in 15 (38.46%) of the placebo group (P = 0.017). Altogether, conversion was obtained in 79.54% of the amiodarone group patients and in 38.46% of the placebo group patients (P < 0.0001). During follow-up, atrial fibrillation relapsed in 13 (37.14%) of 35 patients of the amiodarone group within 8.84 + 8.57 months and in 12 (80%; P = 0.009) of 15 patients of the placebo group within 2.74 ± 3.41 months. Conclusions: Oral amiodarone restored sinus rhythm in one third of patients with chronic atrial fibrillation, increased the success rate of electric cardioversion, decreased the number of relapses and delayed their occurrence.
Effects of Diltiazem and Esmolol on Cycle Length and Spontaneous Conversion of Atrial Fibrillation
Authors: Sticherling Christian , Tada Hiroshi , Hsu William , Bares Anton C. , Oral Hakan , Pelosi Frank , Knight Bradley P. , Strickberger S. Adam , Morady Fred 
Published: June 2007

Background: Calcium channel blocking agents have been shown to prolong the duration of atrial fibrillation. This study compared the effects of intravenous diltiazem and esmolol on the cycle length and conversion rate of pacing-induced atrial fibrillation. Methods and Results: In 41 adults without structural heart disease, atrial fibrillation was induced by rapid atrial pacing. After 3 minutes, either diltiazem (n = 13), esmolol (n = 15), or saline (n = 13) was infused. In the diltiazem group, the atrial fibrillation cycle length shortened by a mean of 43 milliseconds and became significantly shorter than in the control group, while the atrial fibrillation cycle length in the esmolol group did not change. Spontaneous termination of atrial fibrillation occurred significantly less often in the diltiazem group (23%) than in the esmolol (67%, P < 0.05) or placebo groups (77%, P = 0.01). Conclusions: Intravenous diltiazem shortens the atrial fibrillation cycle length and lowers the probability of spontaneous conversion of recent-onset atrial fibrillation to sinus rhythm. These results suggest that the use of diltiazem for acute rate control may unwittingly prolong the duration of recent-onset atrial fibrillation.
Cariporide for Pharmacologic Defibrillation After Prolonged Cardiac Arrest
Authors: Wann Shue-ren , Weil Max Harry , Sun Shijie , Tang Wanchun , Yu Ting 
Published: June 2007

Background: We hypothesized that cariporide, a sodium-hydrogen exchange inhibitor, would be as cardioprotective during the global myocardial ischemia of prolonged cardiac arrest as it is in settings of coronary occlusion.Methods and Results: Fifteen Sprague-Dawley rats were randomized to receive bolus injections of cariporide or placebo in a dose of 3 mg.kg-1into the right atrium either 5 minutes before, or at 8 minutes after, onset of ventricular fibrillation. Ventricular fibrillation was electrically induced and untreated for 8 minutes. Precordial compression, together with mechanical ventilation, was then started and continued for an interval of 8 minutes prior to attempted resuscitation. All but one placebo-treated animal were successfully resuscitated. Spontaneous defibrillation with restoration of circulation was observed in both cariporide-pretreatment and post-treatment groups but in none of the placebo-treated animals. Postresuscitation cardiac index, end-tidal CO2, mean aortic pressure, left ventricular systolic pressure, left ventricular end-diastolic pressure, and left ventricular contractile and lusitropic functions (dP/dt40, and -dP/dt) were significantly less impaired after cariporide, especially in the pretreated group, compared to electrically defibrillated controls. Postresuscitation ventricular premature beats were significantly reduced after cariporide. The duration of postresuscitation survival was significantly increased in animals pretreated with cariporide.Conclusions: Cariporide, when administered prior to and during cardiac arrest, improved both the success of resuscitation and postresuscitation myocardial function.
Effects of Acetaminophen on Myocardial Infarct Size in Rats
Authors: Dai Wangde , Kloner Robert A. 
Published: June 2007

Objective: Acetaminophen is widely prescribed as an analgesic agent in hospitals and clinics. However, acetaminophen theoretically could influence myocardial infarct size by reducing prostaglandin synthesis in vivo. To date, the effect of acetaminophen on myocardial infarct size is unknown. The present study investigated (1) whether acetaminophen has any effect on myocardial infarct size when given in an analgesic dose and (2) whether acetaminophen can affect the cardioprotective effect of the early phase of ischemic preconditioning in rats. Methods: Female Sprague-Dawley rats were randomly assigned to four groups (n = 12 each). Group 1 (no preconditioning): Vehicle (intravenous ethanol, 0.9 mL/kg) was given 39 minutes prior to ischemia. Group 2 (acetaminophen plus no preconditioning): intravenous acetaminophen (125 mg/kg) was given 39 minutes prior to ischemia. Group 3 (preconditioning): The heart was preconditioned before ischemia, and the vehicle (intravenous ethanol, 0.9 mL/kg) was given 39 minutes prior to the ischemia. Group 4 (acetaminophen plus preconditioning): The heart was preconditioned before ischemia, and intravenous acetaminophen (125 mg/kg) was given 39 minutes prior to the ischemia. The preconditioning protocol consisted of three cycles of 3 minutes of coronary occlusion and 5 minutes of reperfusion. The left coronary artery was then occluded for 60 minutes, followed by 3 hours of reperfusion. The end points were hemodynamics, body temperature, and risk area and area of necrosis of the left ventricle. Results: The area of risk was similar among the four groups. The area of necrosis, expressed as a percentage of the area at risk, was 55.7% ± 6.1% in the no-preconditioning group, 62.8% ± 2.4% in the acetaminophen plus no-preconditioning group, 24.7% ± 7.3% in the preconditioning group, and 17.2% ± 6.4% in the acetaminophen plus preconditioning group. The area of necrosis/area at risk was decreased significantly in the preconditioning group and in the acetaminophen plus preconditioning group compared with the no-preconditioning group ( P < .05); but there were no significant differences between the no-preconditioning group and the acetaminophen plus no-preconditioning group (P = .29), or between the preconditioning group and acetaminophen plus preconditioning group (P = .45). Among the four groups, heart rate and body temperature were similar. The infusion of the vehicle or acetaminophen increased blood pressure in the four groups, but to a lesser extent in the acetaminophen group. However, during coronary artery occlusion and reperfusion, the four groups had comparable blood pressures. Conclusion: Acetaminophen had no beneficial or adverse effects on infarct size in nonpreconditioned rats, and the beneficial effects of preconditioning were not blocked or prevented by acetaminophen at this analgesic dose.
Differential Effects of Peroxisome Proliferator Activator Receptor-α and γ Ligands on Intimal Hyperplasia After Balloon Catheter-Induced Vascular Injury in Zucker Rats
Authors: Desouza Cyrus V. , Murthy S. N. , Diez Jose , Dunne Bruce , Matta Anil S. , Fonseca Vivian A. , McNamara Dennis B. 
Published: June 2007

Background: Patients with type 2 diabetes mellitus have a higher rate of restenosis following angioplasty. Peroxisome proliferator activator receptor-x (PPAR) and y ligands such as fenofibrate and rosiglitazone, respectively, have been shown to have protective effects on the vessel wall. We studied the effect of fenofibrate and rosiglitazone on intimal hyperplasia in the Zucker rat, a model for insulin resistance and type 2 diabetes mellitus, following balloon catheter-induced injury.Methods and Results: Three groups of 13-week-old female fatty Zucker rats were administered an aqueous suspension of either 3 mg/kg/d rosiglitazone (n = 7) or 150 mg/kg/d fenofibrate (n = 6) by gavage, or served as controls (n = 9). In addition, two groups of 13-week-old female lean Zucker rats were either administered 3 mg/kg/d rosiglitazone (n = 6) or served as controls (n = 6). Carotid balloon injury was induced 1 week after the drugs were started. The drug administration was continued for 3 weeks. A 2-mm balloon catheter was introduced through the femoral artery to the left carotid. The balloon was inflated to 4 atmospheres for 20 seconds and then was deflated to 2 atmospheres and dragged down to the aorta. The rats were killed 3 weeks after the injury. The carotid intima/media ratio was calculated. Intimal hyperplasia after carotid balloon-induced injury in the fatty Zucker rats was significantly reduced in the group treated with rosiglitazone (0.18 ± 0.29) compared with the untreated group (0.97 ± 0.13; P < .01). Plasma glucose, triglyceride, and insulin levels were elevated, indicative of the presence of insulin resistance; rosiglitazone treatment significantly reduced insulin and triglyceride levels without decreasing glucose. Rosiglitazone treatment also reduced, but to a lesser extent, the intimal hyperplasia in the lean Zucker rats (0.57 ± 0.10 vs 1.06 ± 0.12 treated and untreated, respectively; P < .01); however, it had no effect on insulin, triglyceride, or glucose levels in this group. The intimal hyperplasia in the fatty Zucker rats treated with fenofibrate was not reduced compared with controls (0.84 ± 0.26 vs 0.97 ± 0.13, respectively); fenofibrate reduced insulin and triglyceride, but not glucose levels, in these animals.Conclusions: The PPAR-y ligand rosiglitazone, but not the PPAR-x ligand fenofibrate, decreases intimal hyperplasia following balloon injury in both fatty and lean Zucker rats. This effect of the PPAR-y ligand was independent of glycemia, insulin, and lipid levels, and was more pronounced in insulin-resistant rats.
Effect of Acute Intravenous Cocaine Administration on Endothelium-Dependent Vasodepressor Responses to Acetylcholine
Authors: Pradhan Leena , Dabisch Paul A. , Liles John T. , Agrawal Krishna C. , Kadowitz Philip J. 
Published: June 2007

Background: Cardiovascular events commonly associated with acute and chronic cocaine abuse include coronary vasospasm, arrhythmias, myocardial infarction, and sudden death. It has been suggested that cocaine causes endothelial dysfunction and vasoconstriction by inhibiting local production of nitric oxide and that endothelial dysfunction may be involved in the cardiovascular events associated with cocaine use. The present study investigated the effect of acute intravenous cocaine administration on endothelium-dependent vasodepressor responses to acetylcholine in the anesthetized rat.Methods and Results: Rats were anesthetized with intraperitoneally Inactin (140 mg/kg) and catheters were inserted into the jugular vein and iliac artery for the injection of drugs and measurement of systemic arterial pressure. A thermistor catheter was advanced to the aortic arch for the measurement of cardiac output via the thermal dilution technique. A 5 mg/kg intravenous dose of cocaine, which enhances the vasopressor response to norepinephrine and blocks the vasopressor response to tyramine, had no effect on the vasodepressor response to the endothelium-dependent vasodilator acetylcholine. In addition, responses to the nitric oxide-donor sodium nitroprusside and the vasoconstrictor peptide angiotensin II were not altered by administration of cocaine.Conclusions: Acute administration of cocaine in a dose that blocks norepinephrine uptake into adrenergic terminals had no effect on endothelial function as measured by the absence of an effect on the vasodepressor response to intravenous injections of acetylcholine. Although chronic cocaine exposure has been shown to cause vascular dysfunction, eventually leading to impairment of the nitric oxide pathway, it appears that acute cocaine administration does not inhibit this pathway in the anesthetized rat.
From awareness to acknowledgment: The development of concern among Latina mothers of children with disruptive behaviors
Authors: Arcia Emily , Fernández María C. 
Published: June 2007

The purpose of this study was to describe the process by which Latina mothers become concerned about their children’s disruptive behaviors and deem professional help to be a necessary measure. A sample fo 62 Latina first-time help seekers were asked to narrate their stories of their children’s behavior, the process by which they became concerned, and their decision to seek professional services. Both qualitative and quantitative measures and procedures were used. Key findings include the following. Most mothers described onset after age 3.75. Earlier recognition of disruptive behaviors and earlier concern over these were associated with greater perceptions of functional impairment and with a greater degree of maternal distress at the time of the interview. Increases in awareness and in concern were associated with life events such as moving, migration, and changes in family composition. Mothers often assumed these life events to be causally linked to children’s difficulties. Earlier concern did not speed the awareness process. A “saturation point” was a better descriptor of the culmination of maternal concern than “problem recognition” or “problem labeling” School report of negative behavior was the strongest catalyst to problem acknowledgement. Mothers who recognized onset after their children entered school progressed through the concern process significantly faster than mothers who became concerned at younger child ages.
A chart review study of the Inattentive and Combined Types of ADHD
Authors: Weiss M. , Worling D. , Wasdell M. 
Published: June 2007

Studies of the clinical correlates of the subtypes of Attention-Deficit/Hyperactivity Disorder (ADHD) have identified differences in the representation of age, gender, prevalence, comorbidity, and treatment. We report retrospective chart review data detailing the clinical characteristics of the Inattentive (IA) and Combined (C) subtypes of ADHD in 143 cases of ADHD-IA and 133 cases of ADHD-C. The children with ADHD-IA were older, more likely to be female, and had more comorbid internalizing disorders and learning disabilities. Individuals in the ADHD-IA group were two to five times as likely to have a referral for speech and language problems. The children with ADHD-IA were rated as having less overall functional impairment, but did have difficulty with academic achievement. Children with ADHD-IA were less likely to be treated with stimulants. One eighth of the children with ADHD-IA still had significant symptoms of hyperactivity/impulsivity, but did not meet the DSM-IV threshold for diagnosis of ADHD-Combined Type. The ADHD-IA subtype includes children with no hyperactivity and children who still manifest clinically significant hyperactive symptomatology but do not meet DSM-IV criteria for Combined Type. ADHD-IA children are often seen as having speech and language problems, and are less likely to receive medication treatment, but respond to medical treatment with improvement both in attention and residual hyperactive/impulsive symptoms.
EEG biofeedback vs. placebo treatment for Attention-Deficit/Hyperactivity Disorder: A pilot study
Authors: Heywood C. , Beale I. 
Published: June 2007

Method: Seven children diagnosed with attention-deficit hyperactivity disorder (ADHD) were trained using a standard EEG biofeedback treatment protocol designed to alter SMR/theta ratios and reduce behavioral symptomatology diagnostic of ADHD. During alternate periods they were also trained using a placebo protocol that was identical to the treatment protocol, save that the association between EEG patterns and feedback to the participants was random. Single-case design elements were used to control for the effects of internal validity threats such as maturation, history, and treatment order. Two participants failed to complete all training sessions, and the effects of training on behavior were analyzed both including and excluding these non-completers. Results: When all participants were included in analyses that controlled for overall trend, EEG biofeedback was found to be no more effective than the placebo control condition involving non-contingent feedback, and neither procedure resulted in improvements relative to baseline levels. When overall behavioral trends unrelated to training were not controlled for and noncompleters were excluded from the analysis, it could be mistakenly concluded that EEG biofeedback is significantly more effective than placebo and that the effect sizes involved are moderate to large. These results indicate that many previous reports of the efficacy of EEG biofeedback for ADHD, particularly those presenting series of single cases, might well have been based on spurious findings.
The effects of yoga on the attention and behavior of boys with Attention-Deficit/hyperactivity Disorder (ADHD)
Authors: Jensen Pauline. S. , Kenny Dianna T. 
Published: June 2007

Boys diagnosed with ADHD by specialist pediatricians and stabilized on medication were randomly assigned to a 20-session yoga group ( n = 11) or a control group (cooperative activities; n = 8). Boys were assessed pre- and post-intervention on the Conners’ Parent and Teacher Rating Scales-Revised: Long (CPRS-R:L & CTRS-R:L; Conners, 1997), the Test of Variables of Attention (TOVA; Greenberg, Cormna, & Kindschi, 1997), and the Motion Logger Actigraph. Data were analyzed using one-way repeated measures analysis of variance (ANOVA). Significant improvements from pre-test to post-test were found for the yoga, but not for the control group on five subscales of the Conners’ Parents Rating Scales (CPRS): Oppositional, Global Index Emotional Lability, Global Index Total, Global Index Restless/Impulsive and ADHD Index. Significant improvements from pre-test to post-test were found for the control group, but not the yoga group on three CPRS subscales: Hyperactivity, Anxious/Shy, and Social Problems. Both groups improved significantly on CPRS Perfectionism, DSM-IV Hyperactive/Impulsive, and DSM-IV Total .For the yoga group, positive change from pre- to post-test on the Conners’ Teacher Rating Scales (CTRS) was associated with the number of sessions attended on the DSM-IV Hyperactive-Impulsive subscale and with a trend on DSM-IV Inattentive subscale. Those in the yoga group who engaged in more home practice showed a significant improvement on TOVA Response Time Variability with a trend on the ADHD score, and greater improvements on the CTRS Global Emotional Lability subscale. Results from the Motion Logger Actigraph were inconclusive. Although these data do not provide strong support for the use of yoga for ADHD, partly because the study was under-powered, they do suggest that yoga may have merit as a complementary treatment for boys with ADHD already stabilized on medication, particularly for its evening effect when medication effects are absent. Yoga remains an investigational treatment, but this study supports further research into its possible uses for this population. These findings need to be replicated on larger groups with a more intensive supervised practice program.
The acute effect of methylphenidate in Brazilian male children and adolescents with ADHD: A randomized clinical trial
Authors: Szobot C. M. , Ketzer C. , Parente M. A. , Biederman J. , Rohde L. A. 
Published: June 2007

Objective: To evaluate the acute efficacy of methylphenidate (MPH) in Brazilian male children and adolescents with ADHD. Method: In a 4-day, double-blind, placebo-controlled, randomized, fix dose escalating, parallel-group trial, 36 ADHD children and adolescents were allocated to two groups: MPH ( n = 19) and placebo ( n = 17). Participants were evaluated pre- and posttreatment using the 10-item Conners Abbreviated Rating Scale (ABRS), the Children’s Global Assessment Scale (CGAS), and a simplified version of the Continuous Performance Test (CPT). Results: The MPH group had a significantly greater decrease in ABRS scores and a significantly higher increase in CGAS scores than the placebo group ( p < 0.01). The MPH group showed also a significantly higher proportion of patients with a robust improvement (decrement of at least 50% in the ABRS score after the intervention) than the placebo group ( p < 0.01). The MPH effect size for the ABRS was 1.05 (95% CI = 0.73-1.37). Conclusion: Our results extend the efficacy of MPH on the ADHD core symptoms extensively demonstrated in clinical trials with samples from some developed countries to a sample from a developing country where a diverse culture may modulate the clinical presentation of the disorder.