The Adolescent Lifestyle Questionnaire: development and psychometric testing.

This paper describes the development and psychometric testing of an instrument designed to measure healthy lifestyle in adolescents. The Adolescent Lifestyle Questionnaire (ALQ) was tested on 292 adolescents residing in eastern Canada using item analysis, factor analysis, and reliability measures. Factor analysis isolated seven dimensions to a healthy lifestyle in adolescents, which accounted for 56.

Divergence of endocardial QT interval components during programmed electrical stimulation including observations during induction of sustained ventricular tachyarrhythmias.

Measurements were made in 12 normal subjects and during induction of sustained ventricular tachyarrhythmias in 31 patients with remote myocardial infarction. QT interval measurements were made semiautomatically with computer assistance and the total QT interval was divided into early (QT1) and late (QT2) components. QT intervals and QT interval dispersion between two right ventricular endocardial sites were plotted against the degree of prematurity of the last extrastimulus (S2, S3, or S4).

Unique expression patterns of H19 in human testicular cancers of different etiology.

The expression pattern of the imprinted human H19 gene was investigated in testicular cancers of different etiology, as well as in normal testicular parenchyma, parenchyma without germ cells, and adjacent to testicular germ cell tumors of adolescents and adults (TGCTs), using RNase protection analysis, mRNA in situ hybridization and reverse-transcription polymerase chain reaction. While different total expression levels were detected in spermatocytic seminomas, lymphomas, a Sertoli cell tumor and Leydig cell tumors, none showed a disturbance of monoallelic expression. Strikingly, the majority of invasive TGCTs revealed expression of both parental alleles.

Methylation similarities of two CpG sites within exon 5 of human H19 between normal tissues and testicular germ cell tumours of adolescents and adults, without correlation with allelic and total level of expression.

Testicular germ cell tumours (TGCTs) of adolescents and adults morphologically mimic different stages of embryogenesis. Established cell lines of these cancers are used as informative models to study early development. We found that, in contrast to normal development, TGCTs show a consistent biallelic expression of imprinted genes, including H19, irrespective of histology.

Relation of circadian ventricular ectopic activity to cardiac mortality. CAST Investigators.

The relation between the circadian occurrence of ventricular premature depolarizations (VPD) and sudden arrhythmic death was examined in a subset of patients entered into the Cardiac Arrhythmia Suppression Trial (CAST). Ambulatory electrocardiographic recordings with hourly measurement of VPD frequency were available in 357 patients. Forty percent of the patients (142 of 357) demonstrated circadian variation in VPD frequency between 6:00 A.

The impact of pulse generator longevity on the long-term costs of cardiac pacing.

The long-term costs of cardiac pacing include the device costs, the procedural costs, the follow-up costs, and the replacement costs. At present, there is significant variability in the efficiencies of the integrated circuits and the total battery capacity among different pulse generators that will influence replacement rates over time. Accordingly, we compared the influence of pulse generator longevity on the long-term costs of pacing.

Spatial changes in transmembrane potential during extracellular electrical shocks in cultured monolayers of neonatal rat ventricular myocytes.

This study investigated the role of different types of discontinuities in tissue architecture on the spatial distribution of the transmembrane potential. Specifically, we tested the occurrence of so-called "secondary sources," ie, localized hyperpolarizations and depolarizations during the application of extracellular electrical shocks (EESs). Changes in transmembrane potential relative to action potential amplitude (delta Vm/APA) were measured in patterned cultures of neonatal rat myocytes, stained with voltage-sensitive dye (RH-237), by optical mapping (96-channel photodiode array, 6- to 30-micron resolution) during the application of EES (field strength, 8 to 22 V/cm; duration, 6 ms).

Increased precordial QTc dispersion predicts ventricular fibrillation during acute myocardial infarction.

Electrocardiograms of 19 consecutive patients with acute myocardial infarction complicated by early ventricular fibrillation were compared with those in 19 case-matched patients with acute myocardial infarction not complicated by ventricular fibrillation. The mean precordial QTc interval dispersion in patients with ventricular fibrillation was greater than that of patients without ventricular fibrillation (73 +/- 28 ms vs 30 +/- 12 ms, p < 0.001).

Propafenone pharmacokinetics and pharmacodynamics in patients with sustained ventricular tachycardia.

The myocardium accumulation and pharmacodynamics of propafenone were evaluated during intravenous infusion in 6 patients undergoing electrophysiologic study for evaluation of ventricular tachycardia. The myocardial accumulation of propafenone was delayed and resulted in nonlinear arterial concentration-effect relations.

Cardiac electrophysiological variables in blood-perfused and buffer-perfused, isolated, working rabbit heart.

Effects of crystalloid buffer and blood-buffer perfusates on cardiac electrophysiological parameters were compared in four groups of isolated, working rabbit hearts. Hearts were perfused with Krebs-Henseleit buffer or blood plus Krebs-Henseleit buffer (10% hematocrit) over a range of left ventricular afterload (30-100 cmH2O) and cardiac outputs (30-180 ml/min). Left ventricular monophasic action potential duration (APD) was significantly shorter at low afterload and high cardiac output in buffer-perfused (114 +/- 35 ms) compared with blood-perfused hearts (177 +/- 23 ms, P < 0.

Disadvantaged women and smoking.

High rates of smoking are found among disadvantaged women, and there is a demand for cessation interventions specifically targeted to meet their needs. This project used a number of information sources to examine the factors associated with these women's smoking behaviours and the potential barriers and supports to cessation. Few of the women-centred cessation programs whose representatives were contacted were appropriate for, or available to, disadvantaged women in Canada.

Teens for healthy living.

Improving the health and quality of life of adolescents is a fundamental aspiration of community health nurses. But developing health promotion programs that are attractive to young people can be a major challenge. In a rural Nova Scotia school district, this challenge has been met by bringing the teens themselves into the design and implementation of the program.

Quinidine pharmacodynamics in normal and isoproterenol-induced hypertrophied blood-perfused working rabbit hearts.

Ventricular hypertrophy is associated with several electrophysiologic abnormalities. However, little is known about the pharmacodynamics of antiarrhythmic drugs in the setting of ventricular hypertrophy. We studied the myocardial accumulation and pharmacodynamics of quinidine in 10 control rabbit hearts and 10 with isoproterenol-induced hypertrophy.

Aberrant platelet-derived growth factor alpha-receptor transcript as a diagnostic marker for early human germ cell tumors of the adult testis.

Testicular germ cell tumors are the most common form of cancer in young adult males. They result from a derangement of primordial germ cells, and they grow out from a noninvasive carcinoma-in-situ precursor. Since carcinoma in situ can readily be cured by low-dose irradiation, there is a great incentive for non- or minimally invasive methods for detection of carcinoma in situ.

So long as they both shall live: marital dissolution and the decline of domestic homicide in France, 1852-1909.

This article suggests that the growth of European states, the decline of familism, and the rise of individualism generated the institutionalization of judicial separation and divorce. Time-series analyses of France (1852-1908) reveal a persistent negative association between separation/divorce and domestic homicide, especially among males. Neither indicators of economic change nor trends in the wider pattern of violent crime account for the relationship.

A randomized clinical trial of the noninvasive and invasive approaches to drug therapy for ventricular tachycardia: long-term follow-up of the Calgary trial.

Individualized antiarrhythmic drug therapy for patients with ventricular tachyarrhythmias may be selected by the noninvasive approach (suppression of spontaneous ventricular premature beats) or the invasive approach (suppression of ventricular tachyarrhythmias induced at an electrophysiologic study). There is controversy over which approach is superior. From a screened population of 124 patients with symptomatic ventricular tachycardia or ventricular fibrillation, 57 patients with both frequent ventricular premature beats and inducible ventricular tachycardia at baseline were randomized to have chronic therapy selected by either the noninvasive or invasive approach.

Smoking among disadvantaged women: causes and cessation.

This study aimed to identify social-psychological factors associated with smoking and smoking cessation among disadvantaged women. Individual and group interviews were conducted with disadvantaged women in Atlantic Canada. Participants were predominantly poor, unemployed, geographically isolated, and single parents.

The current status of the implantable cardioverter defibrillator.

Since its initial application in 1980, the implantable cardioverter defibrillator (ICD) has evolved into a highly sophisticated device that offers programmable tiered therapy (antitachycardia pacing, cardioversion, and defibrillation) for ventricular tachyarrhythmias and backup pacing for bradycardia. It also provides diagnosis information about detected events. Successful implantation of nonthoracotomy systems is now routine.