Relationship between heart rate and minute ventilation, tidal volume and respiratory rate during brief and low level exercise.

The correlation between heart rate (HR) and three respiratory parameters, minute ventilation (VE), tidal volume (Vt), and respiratory rate (RR), were studied. Four healthy subjects performed four exercise tests (duration 30 seconds at 50, 100, 150, or 200 W), in random order. Cardio-respiratory parameters were recorded respiratory cycle by respiratory cycle.

Failure of the exercise test to predict the anterograde refractory period of the accessory pathway in Wolff Parkinson White syndrome.

Modifications of the delta wave on the surface ECG during an exercise stress test were compared to electrophysiological variations in accessory pathway (AP) refractoriness and in AV node conduction, during intravenous isoproterenol infusion in ten patients with WPW syndrome. In one patient, the delta wave persisted unchanged at the end of exercise and, with isoproterenol, there was a greater reduction in the AP anterograde effective refractory period (AERP) than in AV node conduction time. In three patients, the delta wave became less and less apparent but without completely disappearing; in these patients, the slight reduction of the AERP in the accessory pathway with isoproterenol was comparable to the reduction in AV node conduction time, explaining the progressive fusion between the two activation fronts.

Collection and characterization of aerosols from metal cutting techniques typically used in decommissioning nuclear facilities.

This study was designed to collect and characterize aerosols released during metal cutting activities typically used in decommissioning radioactively contaminated facilities. Such information can guide in the selection of appropriate control technologies for these airborne materials. Mechanical cutting tools evaluated included a multi-wheel pipe cutter, reciprocating saw, band saw, chop saw, and large and small grinding wheels.

The relation of parenting style to adolescent school performance.

This article develops and tests a reformation of Baumrind's typology of authoritarian, permissive, and authoritative parenting styles in the context of adolescent school performance. Using a large and diverse sample of San Francisco Bay Area high school students (N = 7,836), we found that both authoritarian and permissive parenting styles were negatively associated with grades, and authoritative parenting was positively associated with grades. Parenting styles generally showed the expected relation to grades across gender, age, parental education, ethnic, and family structure categories.

Growth curves and adult height estimation for adolescents.

Using data from the large number of adolescents studied in cycle III of the National Health Examination Survey, we utilized a sexual maturity index to develop a set of growth curves that reduce the distortion caused by commingling height data from adolescents maturing at different rates. We also created a set of correction tables to be used with these curves to permit the calculation of an adjusted height percentile that compensates for the effects of the differing rates of pubertal maturation. These adjusted height percentiles should remain more constant throughout puberty than height percentiles obtained from traditional growth curves; they may thus be used to estimate final adult height with only data obtained during routine physical examinations, by assuming that subjects maintain their adjusted height percentile through adolescence to adulthood.

[New forms of work in general practice].

A trial with job rotation between repetitive jobs failed within a year after initial enthusiasm among the workers. Stress may increase to an intolerable level with the number of tasks, with higher qualified work and due to the lack of familiarity with fellow workers in ever changing settings.

A comparative study of immuno-blotting techniques for the detection of Gc-subtypes after isoelectric focusing on agarose and polyacrylamide gels.

A comparison of separation and detection techniques has been carried out to determine the most suitable combination for use in Gc-subtyping. The best results (i.e.

Physiological relationship between AV interval and heart rate in healthy subjects: applications to dual chamber pacing.

The purpose of this paper is to specify the mathematical relationship between spontaneous AV interval (AVI) and heart rate (HR), the amplitude and rate of variation of AVI, and the physiological factors likely to affect these characteristics. Ten patients with healthy hearts were studied. Two catheter electrodes were positioned in the right atrium and at the tip of the right ventricle respectively, allowing the detection of endocardial signals.

Growth and intellectual development.

Data from the National Health Examination Survey (cycles II and III) provided a representative sample of 13,887 US youths (6 to 17 years of age) with which to examine the relationship between height (normalized for age and sex) and measures of intellectual development (Wechsler Intelligence Scale for Children) and academic achievement (Wide Range Achievement Test). Additionally, 2,177 subjects were studied first in cycle II and 2 to 5 years later in cycle III, forming a well-selected longitudinal study group in which to examine any association between linear growth and change in IQ scores. Wechsler Intelligence Scale for Children and Wide Range Achievement Test scores were significantly correlated with height in both cycle II and cycle III.

Prospective study of computed tomography in initial management of blunt abdominal trauma.

Physical examination is often unreliable in the evaluation of blunt abdominal trauma. The utility of computed tomography (CT) in the early management of abdominal trauma in the absence of definite signs is controversial. CT was prospectively evaluated as an adjunct to physical examination in the initial assessment of blunt abdominal trauma.

The effects of pubertal timing on body image, school behavior, and deviance.

Variation in the timing of pubertal maturation may result in behavioral differences among early, mid-, and late maturers. Using data from the National Health Examination Survey, a national probability sample of children and youth aged 12-17, we investigated the relationships between maturational timing and body image, school behavior, and deviance. In terms of body image, the early maturing boys were the group most satisfied with height and weight.

Single parents, extended households, and the control of adolescents.

This paper uses a representative national sample of adolescents to study the interrelationships among family structure, patterns of family decision making, and deviant behavior among adolescents. Mother-only households are shown to be associated with particular patterns of family decision making and adolescent deviance, even when family income and parental education are controlled. In contrast to adolescents in households with 2 natural parents, youth in mother-only households are perceived as more likely to make decisions without direct parental input and more likely to exhibit deviant behavior.

Plasma amino acids in liver transplantation: correlation with clinical outcome.

The branch chain to aromatic amino acid ratio is depressed in patients with advanced liver disease. Liver transplantation results in three different ratio response patterns: (1) no improvement, (2) transient improvement followed by decline, and (3) sustained improvement. In nine patients who underwent 12 transplantation procedures the ratio rose and remained above 2.

Sexual maturation, social class, and the desire to be thin among adolescent females.

Veblen's 1899 hypothesis that associated a female desire for thinness with the higher social classes was tested with data from a representative national sample of adolescents, 12 to 17 years of age, in the National Health Examination Survey. Controlling for the actual level of fatness, adolescent females in higher social classes wanted to be thinner more often than those in lower classes. The greater female desire for thinness was not the product of health information nor of sex differences in the level of fatness.

Indwelling venous access catheters in patients with acute leukemia.

Reliable venous access is often a serious problem in the cancer chemotherapy patient. In one year, the authors of this report have inserted 26 chronic double-lumen silastic Hickman catheters in 25 acute leukemia patients. Each patient received an average 12 courses of combination chemotherapy, 11.

Studies on pharmacokinetics of STS 557 in animal species and man.

Following oral and i.v. administration of [14 alpha, 15 alpha-3H]-STS 557 to beagle dogs, baboons, rats and female volunteers, plasma level courses of total radioactivity and STS 557, and radioactivity excretion in urine and feces have been investigated.