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Biomedical subjects

E L Besch

Publications and source records attributed to E L Besch.

At least 37 records · Page 2Linked to original sources
PubMed1981

Body temperature, oviposition, and food intake in the hen during continuous light.

Deep-body temperature of the laying hen was measured with an implantable radio transmitter. Food and water intake and oviposition time were recorded, remotely, based on electric signals from microswitches attached to the individual cages. Body temperature and feeding activity of the laying hen under continuous light displayed a circadian rhythm. The length of the body-temperature cycle was 25.2 h, and the feeding cycle was 25.3 h. These values appear to be associated with the animal's laying cycle which was 25.3 h. The laying cycle of the hen can play an important role in the maintenance of circadian rhythms of body temperature and feeding activity. Both the marked temperature rise found at the time of oviposition and the prelaying (or nesting) behavior may be controlled by a preovulatory surge of luteinizing hormone (LH) and progesterone.

Animals↗
PubMed1981

Comparative responses of rabbits and rats to elevated noise.

New Zealand white rabbits and Wistar rats were exposed, in an acoustic chamber, to 1.5 hours of white noise per day at intensities of 107--112 decibels. Compared to the control condition of 60 decibels (background noise level), both rabbits and rats displayed increased adrenal weights (p less than 0.05). Rabbits also had decreased spleen and thymus weights (p less than 0.05). Rats had increased total leukocyte counts and a relative eosinopenia (p less than 0.05). Also, noise exposed rats exhibited a decrease (p less than 0.05) in food intake by the third day of noise exposure. There were no observed changes in hematocrit or plasma protein concentrations.

Animals↗
PubMed1980

Environmental quality within animal facilities.

Maintenance of environmental quality for laboratory animals involves more than heat and moisture production of animals or room air changes per hour. Heating, ventilating and air conditioning of animal facilities allows control of room temperature and humidity, cage microenvironment, gaseous and particulate contamination, air distribution and diffusion, air quality and temperature differentials. However, other factors may influence environmental quality: population density, species of animals, and husbandry and sanitation practices. Because of all of these considerations, animal facilities tend to be energy intensive. Recommended environmental conditions are designed to satisfy physiological requirements of animals but prevent physiologic and psychophysiologic stresses. Analytical studies will provide necessary information to attain these goals and simultaneously reduce energy expenditures or minimize the need for expensive control systems.

Air Conditioning↗
PubMed1978

Calibration of a new ear oximeter in humans during exposure to centrifugation.

An optoelectronic ear oximeter (Hewlett-Packard, model 47201A) was evaluated as a noninvasive method for determining arterial oxygen saturation (SaO2) in human subjects during exposure to various levels of accelerative forces. This physiological calibration involved exposing five subjects, while breathing air and wearing the ear oximeter for 60 s to each of three levels of accelerative forces (3, 5, and 7 G); arterial blood samples were withdrawn concurrently. SaO2 was calculated indirectly from the oxygen tensions (PaO2) measured from the sampled arterial blood with a blood gas analyzer and corrected for pH and base excess. These data were compared, as were similar data taken from the same subjects breathing three different hypoxic gas mixtures while resitng at earth's gravity (1 G). Regression analyses of these data for both experimental groups (a, G exposure, or b, hypoxic exposure), comparing the ear-oximeter SaO2 with the calculated SaO2, showed the ear oximeter to be accurate with correlation coefficients of 0.95 and 0.98, respectively.

Adaptation, Physiological↗
PubMed1978

Telemetry measured body temperature of domestic fowl at various ambient temperatures.

Adult, male Single Comb White Leghorn chickens (SCWL) were housed unrestrained in individual cages in a controlled environment room with a photoperiod of 12L:12D. By means of surgically implanted radio transmitter, body temperatures were recorded hourly for five consecutive days at each of six experimental temperatures: 23, 26, 29, 32, 35, and 38 C. The data were evaluated statistically by correlogram, periodogram, and harmonic analysis. Period length of each cycle was about 24 hr at all ambient temperatures. No significant differences in deep body temperature were observed until the ambient temperature reached 32 C; but highly significant increases were detected between 32, 35, and 38 C. Diurnal differences in body temperature ranged from .6 to 1.1 C. It has been suggested that the body temperature of male chicken may be under the control of a biological clock that synchronizes with the solar day.

Animals↗
PubMed1977

Estrous cycle variations of food and water intake in rats in the heat.

Effects of heat and estrous cycle on food and water intake and on the kinetics of water metabolism were studied in Holtzmann rats, 12 adult females per group. The animals were housed individually in metabolic cages, in series, in a controlled-environment room at (24.5 degrees C) followed by two experimental temperatures (29.2 degrees C and 34.0 degrees C). In all cases relative humidity was 50% and the photoperiod 12L:12D (L = 0600--1800 h). Intake of food and water, available ad libitum, were measured and recorded daily for at least five consecutive estrous cycle (about 25 days). Water turnover was measured using tritiated water. The results indicate that the experimental conditions constituted stressful environments for the rats. Their corticosterone levels were significantly (P less than 0.01) elevated and a relative lymphopenia and neutrophilia (P less than 0.01) were observed. Additionally, food intake was decreased and water intake increased, both significantly (P less than 0.01). Body water turnover was increased (P less than 0.01) while body water pool size and the biological half-life for 3H2O were reduced. However, the cyclic variation of food and water intake and its relationhsip to the estrous cycle were unchanged.

Adrenal Cortex Hormones↗
PubMed1977

Heat dissipation biorhythms of laboratory animals.

Body heat dissipation rates were determined in greyhound and beagle dogs, the rabbit, and the rat. Each group of animals was confined in standard cages in a controlled environment room maintained under conditions of 24 degrees C, 50% relative humidity, and fixed ventilation rats. Food and water were available ad libitum. Heat dissipation rates were determined for each group and normalized to an individual animal basis. The ratio of actual heat dissipation to standard metabolic rate, the metabolic heat ratio, was 2.01+/-0.18 for the greyhound, 1.98+/-0.03 for the beagle, 2.66+/-0.20 for the rabbit, and 1.95+/-0.13 for the rat. For each species, the ratio displayed a 24-hour cyclic pattern in which four contiguous maximum values differed significantly from four contiguous minimum values. The ratios of maximum values to minimum values were between 1.54 and 1.75.

Animals↗
PubMed1975

Experimental evaluation of heat and moisture transfer in metal dog cage environments.

Dog cages with solid and expanded metal flooring were tested while unoccupied, occupied by a 10-kg adult male beagle, and occupied by simulated loads to represent a beagle and a greyhound. Cage performances were evaluated with no direct coupling between the room air supply and the cage, and with mechanical coupling of 50% and 100% of the room air supplied directly to the cage. At each of these conditions, the room was maintained at approximately 24 degrees C and 45% relative humidity with room air exchange rates of 5, 10, and 15 changes per hr. Results indicated significant differences existed in dry-bulb and dew-point temperatures between the cage and the room. These differences, together with significant vertical gradients of air velocity and dry-bulb and dew-point temperatures within the cage were shown to be affected by room air exchange rate, cage flooring, type of coupling, and cage load.

Air↗