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Biomedical subjects

R H Strauss

Publications and source records attributed to R H Strauss.

12 recordsLinked to original sources
PubMed1992

Aeromedical transport services accepting pediatric patients and their abidance by published guidelines.

The number of aeromedical transport services accepting pediatric patients (ATSP) in the United States has increased greatly over the past decade. Most aeromedical transport services are primarily designed for adults but will also transport children. Suggested guidelines for ATSP were published by the American Academy of Pediatrics (AAP) in 1986. This survey of 65 ATSP and their abidance by the major AAP guidelines showed that two thirds of the ATSP were based at facilities with pediatric tertiary care capabilities; most ATSP were not directed by pediatric critical care (PCC) or pediatric emergency care (PEC) specialists; most transport team personnel were not trained in PCC or PEC; most ATSP had specific protocols for different clinical situations; most ATSP had separate equipment appropriate for pediatric patients; and there was little variation in transport team composition based on different clinical situations. In summary, all ATS surveyed transported children, but few were aware of the AAP guidelines, and only one in 65 was in complete abidance with the recommendations.

Adult↗
PubMed1979

Role of respiratory heat exchange in production of exercise-induced asthma.

We have hypothesized that it is the total heat flux in the tracheobronchial tree during exercise that determines the degree of postexertional obstruction in asthma, and have developed quanititative expressions that relate these two events. We tested this hypothesis by comparing the observed responses to exercise, while our subjects inhaled dry air at various temperatures ranging from subzero to 80 degrees C in a random fashion, to those that we predicted would occur based upon calculations of respiratory heat exchange. We further determined if heat could be transferred from the inspired air to the mucosa so as to offset evaporative losses from the airways. The observed responses fell as air temperature was increased from -11 to +37 degrees C and exactly matched theoretical predictions. Above 37 degrees C, the observed response exceeded predictions, indicating that it was not possible to provide sufficient heat per se in the air to offset the vaporization of water. However, when small amounts of water vapor were added to the inspirate at high temperatures, bronchospasm was virtually abolished and the response again closely matched theoretical expectations. We conclude that the magnitude of exercise-induced asthma is directly proportional to the thermal load placed on the airways and that this reaction is quantifiable in terms of respiratory heat exchange.

Adult↗
PubMed1979

Diving medicine.

Explore the source record for details and available documents.

Asthma↗
PubMed1978

Influence of heat and humidity on the airway obstruction induced by exercise in asthma.

We examined the degree of airway obstruction that developed in eight asthmatics who exercised while breathing air under four conditions: (a) ambient room temperature and water content; (b) body temperature and ambient water content; (c) ambient room temperature fully saturated; and (d) body temperature fully saturated. These test conditions were performed in random order. Multiple aspects of pulmonary mechanics were measured before and 5 min after exercise. When air at ambient conditions was inhaled, the expected airway obstruction developed after exercise, and all variables changes significantly from their pre-challenge values. Heating the air to body temperature did not influence this response. Increasing the humidity at ambient temperatures significantly blunted the response, and by inhaling body temperature, fully saturated air completely prevented it from occurring. Thus, the water content of inspired air is an important variable in the development of exercise induced asthma.

Adult↗
PubMed1977

Enhancement of exercise-induced asthma by cold air.

To study the possibility that the inhalation of cold air accentuates the bronchoconstrictor response to exercise in asthma, eight subjects exercised while breathing air at ambient or subfreezing temperatures. On a separate day, cold air was breathed at rest so as to isolate the effects of this stimulus. Pulmonary mechanics were measured before and after each experiment. In all subjects acute bronchoconstriction followed the control exercise challenge. With cold-air breathing, however, the magnitude of the response was markedly enhanced. Residual volume increased 158 per cent more than it did previously, and specific conductance and one-second forced expiratory volumes changed an additional 85 and 100 per cent, respectively. The effects of cold air at rest were very small. The results demonstrate a positive interaction of two common naturally occurring stimuli in the induction of asthmatic attacks, and constitute objective verification of a frequent clinical complaint.

Adult↗
PubMed1977

Comparison of arm versus leg work in induction of acute episodes of asthma.

The severity of exercise-induced asthma varies with the type of exercise performed. To determine whether such variation could be attributed to the use of different muscle groups, we exercised arms separately from legs using a bicycle ergometer. First, arms were exercised to exhaustion, then legs were exercised at the same load for the same duration. Arm work resulted in greater ventilation, heart rate, hydrogen ion concentration, and airway obstruction than did leg work. Later, legs were exercised to exhaustion using a load more than twice that of the arm work. Both the exhausting leg work and exhausting arm work resulted in significant bronchospasm and acidosis, whereas the nonexhausting leg work did not. These data suggest that, in arm and/or leg exercise, the relationship of work load to muscle mass is a determinant of airway obstruction.

Adult↗
PubMed1977

A critical assessment of the roles of circulating hydrogen ion and lactate in the production of exercise-induced asthma.

To evaluate the roles of circulating hydrogen ion and lactate in the production of exercise-induced asthma, two experiments were performed. In the first, we exercised six asthmatic subjects to exhaustion on a bicycle ergometer while recording arterial pH at periodic intervals. Multiple aspects of pulmonary mechanics were measured before and after the work load. After recovery, the identical procedures were repeated, but sufficient quantities of sodium bicarbonate were infused to keep the pH at the pre-exercise level. In both experiments, statistically identical attacks of asthma were induced. To study the effect of lactate, five subjects were exercised on several occasions in order to determine the lowest level of work, and hence arterial lactate, that was reproducibly associated with an acute asthma attack. When this was known, sufficient quantities of sodium lactate were infused into the resting subjects so as to equal or exceed the amount produced with exercise. Pulmonary mechanics were not altered with this intervention. These findings demonstrate that lactic acidemia is not the cause of exercise-induced asthma.

Acidosis↗
PubMed1977

Bubble formation within decompressed hen's eggs.

Decompression sickness follows a reduction in ambient pressure and is a result of bubble formation in blood or tissues. The origin of such bubbles is the subject of considerable controversy, and a number of mechanisms have been proposed to account for them. In testing these mechanisms, freshly-laid hen's eggs provide a particularly intriguing model--namely, an intact biological system in which bubbles form readily and many of the proposed processes are excluded.

Animals↗
PubMed1976

Marijuana smoking and cold tolerance in man.

Ten men who were marijuana users served as subjects in a study of the effects of marijuana smoking on response to cold. Cold water (28 degrees C for 60 min) and cold air (20 degrees C for 120 min) mediums were utilized with three exposures in each medium. The three exposures followed smoking marijuana, smoking placebo, and a no-smoking control period. Additionally, a breathhold experiment preceded and followed the four smoking periods. Marijuana and placebo smoke were inhaled from a spirometer with each man receiving the smoke of 0.739 g of marijuana and placebo. Smoking marijuana did not greatly modify body heat content, since rectal temperature and most peripheral temperatures were not altered. However, temperatures over voluntary muscles likely to be involved in shivering were elevated. Heat production also greatly increased after marijuana, suggesting that it had stimulated shivering. Marijuana also produced tachycardia and abolished apneic bradycardia. The mechanism of this action is not clear, but some sympathetic involvement is indicated.

Adaptation, Physiological↗
PubMed1976

Acute lung injury induced by cadmium aerosol. I. Evolution of alveolar cell damage.

Following exposure to an aerosol of 0.1% (.005 M) cadmium chloride, rat lungs were examined at 6 hours and 1, 2, 3, 4, 7, and 10 days. By light microscopy, damage was multifocal and centered about respiratory bronchioles. Ultrastructurally, there was Type 1 cell edema with frequent loss of surface plasma membranes during the first 24 hours. After 2 days, the number of Type 2 cells had markedly increased, and by 3 days the damaged alveoli were lined by plump cuboidal cells closely resembling Type 2 cells. By 4 days, these cells were flatter, the change being more marked by 7 days; by 10 days, the cells had regained the appearance of Type 1 cells through loss of osmiophilic bodies and superficial microvilli. We conclude that CdCl2 damages Type 1 cells, which are then replaced by proliferation of Type 2 cells. These cells lose their osmiophilic bodies and flatten out to replace the lost Type 1 cells, the process being almost complete by 10 days after the injury. This pattern resembles the injury caused by NO2, O3, and O2.

Aerosols↗
PubMedDate not supplied

Psychological moods and subjectively perceived behavioral and somatic changes accompanying anabolic-androgenic steroid use.

To assess physiological and psychological states accompanying anabolic-androgenic steroid use, male weight lifters 1) were interviewed regarding their physical training and the patterns and effects of any drug use; 2) completed a written physical and medical history questionnaire, a Profile of Mood States questionnaire, and the Buss-Durkee Hostility Inventory; and 3) were physically examined, including a blood sample and urinalysis. Subjects were divided into current anabolic-androgenic steroid users (N = 12), previous users (N = 14), and nonusers (N = 24). Current and previous users reported the following changes associated with anabolic-androgenic steroid use: increases in enthusiasm, aggression, and irritability; changes in insomnia, muscle size, muscle strength and density; faster recovery from workouts and injuries; and changes in libido. We were unable to confirm these interview and physical and medical history questionnaire responses using standardized and well-accepted psychological inventories. There were no significant differences among groups for any Profile of Moods factor, total mood disturbance, total Buss-Durkee Hostility Inventory score, or any subscale. For current users, there were no significant correlations between either total weekly drug dose or length of time on the current cycle of anabolic-androgenic steroids and any individual scale of the Profile of Mood States, Buss-Durkee Hostility Inventory, Profile of Mood States total mood disturbance, or composite Buss-Durkee Hostility Inventory score. Furthermore, anabolic-androgenic steroid users did not differ in their responses on these inventories from nonusers or from general population norms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗