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R Shaw

Publications and source records attributed to R Shaw.

At least 181 records · Page 10Linked to original sources

Effect of temperature on invertase, invertase inhibitor, and sugars in potato tubers.

The accumulation of reducing sugars in potato tubers exposed to low temperatures occurs with concomitant formation of the enzyme invertase. During the initial period of cold treatment when reducing sugars increase rapidly, invertase formation proceeds until the level of enzyme exceeds that of an endogenous macromolecular invertase inhibitor, resulting in a basal invertase activity. As the rate of sugar accumulation decreases and the sugar level becomes nearly constant, total invertase decreases, the basal activity disappears, and a low excess of inhibitor develops. On transfer of cold-stored tubers to warmer temperatures, sugars and invertase decrease sharply and a large excess of inhibitor develops. These changes in sugars, invertase and inhibitor occur reversibly when the tubers are subjected to alternating temperatures.

Journal Article↗

Patient or person.

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Nurse-Patient Relations↗

The Academy of Psychosomatic Medicine practice guidelines for psychiatric consultation in the general medical setting. The Academy of Psychosomatic Medicine.

This practice guideline seeks to provide guidance to psychiatrists who regularly evaluate and manage patients with medical illnesses. The guideline is intended to delineate the knowledge base, professional expertise, and integrated clinical approach necessary to effectively manage this complex and diverse patient population. This guideline was drafted by a work group consisting of psychiatrists with clinical and research expertise in the field, who undertook a comprehensive review of the literature. The guideline was reviewed by the executive council of the Academy of Psychosomatic Medicine and revised prior to final approval. Some of the topics discussed include qualifications of C-L consultants, patient assessment, psychiatric interventions (e.g., psychotherapy, pharmacotherapy), medicolegal issues, and child and adolescent consultations.

Adolescent↗

Supine bicycle stress echocardiography: peak exercise imaging is superior to postexercise imaging.

The abilities of peak exercise (PEAK) stress echocardiography versus postexercise (POST) stress echocardiography to detect coronary artery disease were evaluated in 136 consecutive patients undergoing supine bicycle stress echocardiography and coronary arteriography: 42 (31%) had normal coronary vessels, 38 (28%) had single-vessel disease, 34 (25%) had double-vessel disease, and 22 (16%) had triple-vessel disease. The results were as follows: (1) For detection of disease in the group of patients, sensitivity of PEAK versus POST was 94% versus 83% (p < 0.01) and specificity was 88% versus 90%. (2) For detection of disease in specific vessels, sensitivity of PEAK versus POST was 90% versus 72% (p < 0.0001) and specificity was 89% versus 92%. (3) For evaluation of the three major coronary arteries, sensitivity of PEAK versus POST was 96% versus 85% (p < 0.05) for the left anterior descending artery, 90% versus 65% (p < 0.01) for the right coronary artery, and 79% versus 60% (p < 0.05) for the left circumflex coronary artery. There were no differences in specificity. (4) The percent diameter stenosis of vessels normalizing from PEAK to POST versus vessels abnormal at PEAK and POST was 80.6% +/- 16% versus 85.9% +/- 14%, p = 0.07. There were no differences in exercise parameters between patients with and without resolution from PEAK to POST. (5) PEAK versus POST accuracy for identification of patients with multivessel disease was 93% versus 68% (p < 0.001). We conclude that stress echocardiography performed during peak exercise is superior to postexercise stress echocardiography.

Coronary Angiography↗

Supine bicycle stress echocardiography versus tomographic thallium-201 exercise imaging for the detection of coronary artery disease.

To compare the accuracy of supine bicycle stress echocardiography (SBSE), a new technique for evaluating coronary disease during peak exercise, with tomographic thallium-201 exercise imaging (SPECT), 71 patients were evaluated by SBSE, SPECT, and coronary arteriography. Twenty patients had normal coronary vessels; 22 had single-vessel, 14 had double-vessel, and 15 had triple-vessel disease. There were no differences in sensitivity (90% vs 92%), specificity (80% vs 65%), and accuracy (87% vs 85%) between SBSE and SPECT for the group of 71 patients. The results were similar in patients with and without prior myocardial infarction and with single-, double-, or triple-vessel disease. There were no differences between SBSE and SPECT for disease detection for the group of 213 individual vessels in sensitivity (88% vs 80%), specificity (87% vs 84%), and accuracy (88% vs 82%), but SBSE was more sensitive for the left anterior descending artery (97% vs 82%, p < 0.005) and for arteries involved in triple-vessel disease (93% vs 69%, p < 0.01) and more specific for the right coronary artery (88% vs 66%, p < 0.01). Supine bicycle exercise was associated with significantly lower maximal heart rates than treadmill exercise but with significantly higher systolic and diastolic blood pressures. There were no differences in heart rate x systolic blood pressure. We conclude that SBSE and SPECT are equally reliable for coronary disease detection in patients and for evaluation of disease in specific arteries with the exception of SBSE's higher sensitivity for the left anterior descending artery and arteries involved in triple-vessel disease and higher specificity for the right coronary artery.

Coronary Disease↗

Elevated levels of psychophysiological arousal and cortisol in patients with somatization syndrome.

OBJECTIVE: This study investigates psychological and psychobiological processes in patients with somatization syndrome. METHOD: We compared physiological measures (heart rate, finger pulse volume, electrodermal activity, electromyography), cortisol levels, and subjective well-being during rest and during a mental stress task as well as selective attention and memory for illness-related words in 58 patients with somatization syndrome and 21 healthy controls. RESULTS: The somatization group had higher morning salivary cortisol concentrations, higher heart rates, and lower levels of finger pulse volume. During the mental stress task, patients with somatization syndrome felt more distressed and had higher heart rates, whereas controls showed habituation to the experimental situation. We were unable to demonstrate an attention or memory bias specific for somatization. CONCLUSIONS: The results point to several psychological, psychophysiological, and psychobiological mechanisms that might be involved in the maintenance of somatization syndrome. These results are discussed from a cognitive-psychobiological perspective.

Adolescent↗