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Biomedical subjects

S A Thomas

Publications and source records attributed to S A Thomas.

At least 109 records · Page 6Linked to original sources
PubMed1984

Changes in nurses' blood pressure and heart rate while communicating.

Cardiovascular responses of nurses were measured during two communication tasks. In the first experiment 40 nurses' blood pressures and heart rates were taken pre, during, and post change-of-shift report. In the second experiment, 30 nurses spoke to an individual nurse and to a group of nurses. Blood pressures and heart rates were recorded pre, during, and post speech in both conditions. Analyses of variances showed that speaking levels of all cardiovascular parameters were higher (p less than .001) than resting levels in both experiments. Blood pressures and heart rates were higher (p less than .0001) in front of a group than in front of an individual. These findings extend previous work that has shown communication alters blood pressure.

Adult↗
PubMed1984

Chloroplast ultrastructure, chlorophyll fluorescence, and pigment composition in chilling-stressed soybeans.

Shoots of 16-day-old soybeans (Glycine max L. Merr. cv Ransom) were chilled to 10 degrees C for 7 days and monitored for visible signs of damage, ultrastructural changes, perturbations in fluorescence of chlorophyll (Chl), and quantitative changes in Chl a and b and associated pigments. Precautions were taken to prevent the confounding effects of water stress. A technique for the separation of lutein and zeaxanthin was developed utilizing a step gradient with the high performance liquid chromatograph. Visible losses in Chl were detectable within the first day of chilling, and regreening did not occur until the shoots were returned to 25 degrees C. Ultrastructurally, unstacking of chloroplast grana occurred, and the envelope membranes developed protrusions. Furthermore, the lipids were altered to the point that the membranes were poorly stabilized by a glutaraldehyde/osmium double-fixation procedure. Chl fluorescence rates were greatly reduced within 2 hours after chilling began and returned to normal only after rewarming. The rapid loss of Chl that occurred during chilling was accompanied by the appearance of zeaxanthin and a decline in violaxanthin. Apparently a zeaxanthin-violaxanthin epoxidation/de-epoxidation cycle was operating. When only the roots were chilled, no substantial changes were detected in ultrastructure, fluorescence rates, or pigment levels.

Journal Article↗
PubMed1983

Social interaction and blood pressure. Influence of animal companions.

The effect of the presence of a friendly animal on children's blood pressures and heart rates while resting and their cardiovascular responses to verbalization were examined. The presence of the dog resulted in lower blood pressures both while the children (N = 38) were resting and while they were reading. The effect of the presence of the dog was greater when the dog was present initially than when it was introduced in the second half of the experiment. We speculate that the animal causes the children to modify their perceptions of the experimental situation and the experimenter by making both less threatening and more friendly. This study provides insight into the use of pets as adjuncts in psychotherapy.

Adolescent↗
PubMed1983

Short and long term effects of root and shoot chilling of ransom soybean.

The immediate short term effects on some physiological processes and the long term effects on morphology and reproductive development of root- and shoot-chilled soybeans (Glycine max L. cv Ransom) were studied. Roots or shoots of 16- or 17-day-old plants were chilled at 10 degrees C for one week, and then rewarmed to 25 degrees C. Leaf elongation rate, net CO(2) uptake rate, and stomatal conductance decreased during root or shoot chilling. Root chilling had only temporary effects on water relations, while shoot chilling caused large changes in potentials during chilling. Most processes measured returned to control levels after two days of rewarming. Root-chilled plants harvested 90 days after emergence were similar in morphology and seed weight to controls. Shoot-chilled plants showed a large increase over controls in axillary branch growth, but an early abortion of flowers and a delayed resumption of flowering caused a 78% reduction in seed weight. Root chilling in this study was found to have little or no long term effect on the plants, while shoot chilling caused significant changes in vegetative morphology, and a delay in flowering and subsequent pod filling.

Journal Article↗
PubMed1982

The effect of status on blood pressure during verbal communication.

Blood pressures and heart rates of 40 subjects were recorded at 1-min intervals over 35 min during which subjects engaged in a variety of verbal activities with either a high-status or an equal-status experimenter. All subjects showed statistically significant increases in blood pressure and heart rate when speaking compared to when quiet. Blood pressure increases during speaking of the 20 subjects exposed to a high-status experimenter were significantly greater than those of subjects exposed to an equal-status experimenter. While the blood pressure increase was related partly to the act of speaking, the amount of increase was also related to the social distance between experimenter and subject. The results are discussed relative to behavioral interventions for the treatment of hypertension.

Adult↗
PubMed1982

Interpersonal aspects of blood pressure control.

Recent observations of large, consistent increases in blood pressure during human communication prompted a reassessment of the role of interpersonal factors in the behavioral control of hypertension. It was noted that the conceptual framework around which earlier behavioral studies have been carried out, as well as in the physical methods of pressure determination themselves, have contributed to a general lack of information about the role of interpersonal interactions in hypertension. An awareness of the relationship between speaking and pressure elevations has led to the development of a new conceptual approach to understanding the etiology and treatment of hypertension. Using techniques developed out of transactional psychophysiology, hypertensive patients have been able to observe the importance of interpersonal communications in the regulation of their own blood pressure. Evidence from the clinical use of such information suggests that a new way can be developed to help patients lower their blood pressure.

Behavior Therapy↗
PubMed1982

The effects of normal and rapid speech on blood pressure.

The effects of two rates of speech on blood pressure and heart rate were measured in 30 normotensive individuals. Verbalization was linked to rapid and significant rises in blood pressure. Faster rates of speaking were associated with greater increases in blood pressure. These findings are discussed in light of earlier research on the blood pressure communication response and are evaluated in the context of the speech pattern characteristics of the Type A (coronary-prone) individual. Clinical applications of this research for hypertensive and Type A individuals are discussed.

Adult↗
PubMed1982

Automated blood pressure recording: the phenomenon of blood pressure elevations during speech.

The recent development of automatic non-invasive blood pressure devices has allowed the rapid and repeated assessment of both the blood pressure and pulse rate in the clinical setting. The development of this technology has allowed us to observe a striking relationship between human communication and blood pressure. Talking produces rapid increases in their systolic, diastolic and mean arterial pressures as well as pulse rate in both normotensive and hypertensive subjects. This phenomenon has been obscured by the conventional assessment techniques of blood pressure measurement. Ignoring the pattern of verbal communication during the assessment of blood pressure can result in marked differences in recorded blood pressure and its interpretation.

Adult↗
PubMed1982

Blood pressure changes while talking.

Using a noninvasive automatic device to rapidly and repeatedly measure blood pressure, a striking relationship was found between talking and an increase in blood pressure and heart rate. This finding was demonstrated in a variety of experimental settings (the laboratory, medical clinic, classroom and home) in both children and adults and in both normotensive and hypertensive individuals. A significant positive correlation was also observed between the level of resting pressure and the magnitude of increase in pressure while talking. These findings point toward an important link between human communication and blood pressure control that has previously been overlooked. They also suggest a new conceptual approach to the understanding and treatment of hypertension.

Adolescent↗
PubMed1981

The effects of talking on the blood pressure of hypertensive and normotensive individuals.

The use of a recently developed noninvasive automated blood-pressure device has revealed a striking relationship between human communication and elevations in blood pressure in both normotensive and hypertensive individuals. Individuals with higher resting baseline pressures tended to show greater increases during talking than did those with lower pressures. In some hypertensive individuals increases blood pressure greater than 25-40% occurred within 30 sec after the initiation of human speech. Links between difficulties surrounding human communication and elevations in blood pressure are discussed.

Adult↗
PubMed1980

Human speech and blood pressure.

The recent development of a noninvasive automated blood pressure device has revealed a strong relationship between human conversation and blood pressure. Conventional techniques of pressure measurement such as the stethoscope and manometer, which require silence during the measurement, tended to obscure this important relationship. Findings from this study indicate that interpersonal communications surrounding the measurement of blood pressure can rapidly alter systolic and diastolic pressures. In certain situations, changes greater than 20 per cent in systolic and diastolic blood pressure and heart rate can occur within 30 seconds after the initiation of human speech. Such variance can be of critical significance in making clinical judgments concerning hypertension. These findings are discussed in the context of recent nonpharmacological treatment approaches being developed to help control hypertension.

Adult↗
PubMed1979

Some aspects of sleep disturbance in coronary patients.

Of 42 coronary care patients studied during 10 hr. of polygraphically recorded sleep, 28 were in an open-ward coronary care unit and 14 were in a semi-private telemetry unit. The observed sleep disturbances were not a function of type of unit, length of hospitalization, sex, or medications. Sleep was significantly less fragmented in those patients judged less severe in pathology. These results indicate that alterations in normal sleep patterns occur routinely within coronary care environments, even in the absence of disturbing environmental stimuli and suggest that a closer analysis be made of sleep in these settings in light of the known relationships between sleep and cardiac function.

Adult↗
PubMed1977

Psychological aspects of cardiac arrhythmia.

A review of data from a wide spectrum of research studies suggests that psychological-emotional factors can significantly influence and alter the incidence of cardiac arrhythmia. While the existing data are, in many cases, difficult to interpret because of theoretical and methodological problems, sufficient evidence does exist to warrant a concerted investigation into the total involvement of psychological factors in cardiac arrhythmia.

Animals↗
PubMedDate not supplied

Modeling the potential radionuclide transport by the Ob and Yenisey Rivers to the Kara Sea.

A major portion of the former Soviet Union (FSU) nuclear program is located in the West Siberian Basin. Among the many nuclear facilities are three production reactors and the spent nuclear fuel reprocessing sites, Mayak, Tomsk-7, and Krasnoyarsk-26, which together are probably responsible for the majority of the radioactive contamination found in the Ob and Yenisey River systems that feed into the Arctic Ocean through the Kara Sea. This manuscript describes ongoing research to estimate radionuclide fluxes to the Kara Sea from these river systems. Our approach is to apply a hierarchy of simple models that use existing and forthcoming data to quantify the transport and fate of radionuclide contaminants via various environmental pathways. We present an initial quantification of the contaminant inventory, hydrology, meteorology, and sedimentology of the Ob River system and preliminary conclusions from portions of the Ob River model.

Arctic Regions↗