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Biomedical subjects

D Russell

Publications and source records attributed to D Russell.

At least 235 records · Page 13Linked to original sources
PubMed1986

Studies of Doppler aortic flow velocity during supine bicycle exercise.

Although Doppler echocardiography is useful in the assessment of left ventricular function at rest, little information is available on the application of this technique during exercise. Consequently, Doppler aortic flow studies were performed in 17 young normal subjects during and after supine bicycle exercise. The purposes of the study were to determine the feasibility of recording Doppler aortic flow velocity with a suprasternal notch transducer during exercise and to assess the changes in normal aortic flow velocity parameters during exercise and early recovery. Each subject exercised until fatigue; mean duration of exercise was 10 minutes. Heart rate increased from a mean of 69 beats/min at control to 159 beats/min at peak exercise. On average, aortic peak flow velocity increased by 45% from control, reaching its maximum at 2 minutes after exercise. Ejection time decreased by 34% during exercise, being shortest at peak exercise. Heart rate, peak flow velocity and ejection time had not returned to normal by 10 minutes after exercise. Aortic flow velocity integral (a relative measure of stroke volume) decreased by 10% at peak exercise (p less than 0.05) compared with control, but had returned to control at 2 minutes after exercise. Despite mild aliasing, increased spectral dispersion, faster heart rates and increased respiratory rate during maximal exercise, aortic flow velocity measurements could be recorded using the suprasternal technique. These baseline Doppler exercise data should be useful in further studies of exercise hemodynamic changes in patients with heart disease.

Adolescent↗
PubMed1986

Left ventricular filling in hypertrophic cardiomyopathy: a pulsed Doppler echocardiographic study.

Abnormal left ventricular diastolic properties have been described in patients with hypertrophic cardiomyopathy. To evaluate the diastolic filling characteristics of the left ventricle in patients with this disease, pulsed Doppler echocardiography was used to study mitral flow velocity in 17 patients with hypertrophic cardiomyopathy (11 with and 6 without systolic anterior motion of the mitral valve) and 16 age-matched normal subjects. There were no statistically significant differences between patients with hypertrophic cardiomyopathy with and without systolic anterior motion with regard to ventricular septal thickness, left ventricular posterior wall thickness, left ventricular internal dimensions or the extent of hypertrophy evaluated by two-dimensional echocardiography. Mitral regurgitation was detected by Doppler echocardiography in all 11 patients with and in 2 (33%) of the 6 patients without systolic anterior motion of the mitral valve. Early and late diastolic peak flow velocity, the ratio of late to early diastolic peak flow velocity and deceleration of early diastolic flow were measured from Doppler mitral flow velocity recordings. There were no statistically significant differences in these four indexes between the patients with systolic anterior motion and normal subjects. In contrast, the patients with hypertrophic cardiomyopathy without systolic anterior motion showed lower early diastolic peak flow velocity, higher ratio of late to early diastolic peak flow velocity and lower deceleration of early diastolic flow compared with the patients with systolic anterior motion and normal subjects, suggesting impaired left ventricular diastolic filling.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Social support and adaptation to stress by the elderly.

The first of a two-phase project is reported that examined the prospective effects of stress and social support on the physical and mental health of the elderly. A sample of 50 elderly subjects was assessed at two points in time over a 6-month period. Results indicated that social support was a significant predictor of physical health status, whereas mental health was related to the Stress X Social Support interaction term. These latter results were consistent with the buffering hypothesis, in that high levels of social support served to reduce the negative impact of stress on mental health. Individuals who were in better mental health at the initial assessment experienced fewer stressful events and higher levels of social support over the subsequent 6-month period. The implications of these findings for research and theory regarding the relation between stress and social support are discussed.

Aged↗
PubMed1986

Herpes zoster ophthalmicus with cerebral angiitis and reduced cerebral blood flow.

Two patients with herpes zoster ophthalmicus (HZO) who experienced a delayed contralateral hemiparesis, the so-called crossed zoster syndrome, are described. Particular emphasis is paid to the cerebral blood flow (CBF) findings studied with the Xenon-133 inhalation technique using single photon emission computed tomography (SPECT). In a 40-year-old female with right-sided hemiparesis, angiography showed multiple segmental narrowings of the intracerebral arteries. Cerebral computer tomography (CT) scans were normal. The CBF studied 11 months after the HZO showed a generalized reduction of flow which, however, was more pronounced in the left hemisphere. On re-examination 8 months later both the mean hemispheric flow and regional CBF (rCBF) had increased to normal values. In a 66-year-old male with dysphasia and right-sided hemiparesis, cerebral CT scans demonstrated two small deep left-sided infarcts. CBF examination showed a generalized reduction of flow in the left hemisphere. The flow was slightly increased on re-examination 12 months later. These findings suggest that the Xenon-133 inhalation method represents a useful way to demonstrate the CBF pattern in this group of patients.

Adult↗
PubMed1986

Patency and flow velocity profiles in the internal carotid artery assessed by digital subtraction angiography and Doppler studies three months following endarterectomy.

Pulsed Doppler spectral analysis and intravenous digital subtraction angiography have been carried out in 55 patients, three months after a total of 60 carotid endarterectomies. Five patients were operated on both sides and there were no re-operations. There were no re-stenoses and only one of the 60 internal carotid arteries was occluded. Spectral spreading of of the Doppler signal at the site of the endarterectomy was found in 52% of the internal carotid arteries, whereas wall irregularities were demonstrated in 25% by intravenous digital subtraction angiography. A stenosis or occlusion was found in 11 (18%) of the 60 ipsilateral external carotid arteries.

Carotid Artery Diseases↗
PubMed1986

Long-term effects of incestuous abuse in childhood.

The authors studied two groups of adult women with histories of incest, a nonclinical sample (N = 152) and an outpatient sample (N = 53). Women in the community sample reported a range of long-term effects from the incest. The great majority said they had been upset by their incest experiences, but about half said they had recovered well from their trauma. Most women who had suffered forceful, prolonged, or highly intrusive sexual abuse, or who had been abused by their father or stepfather, reported long-lasting negative effects. The patient sample reported histories comparable to the most severe traumatic histories in the community sample.

Adolescent↗
PubMed1986

Ketazolam once daily for spasticity: double-blind cross-over study.

This double-blind cross-over study of 14 severely spastic inpatients with chronic multiple sclerosis reveals that once-daily doses of ketazolam, a new drug, are effective in reducing spasticity in a significant proportion of patients without significant side-effects. Added to the similar findings of an earlier double-blind controlled study of divided doses, the results suggest that this special feature of ketazolam provides a unique flexibility that may be exploited in individual cases.

Acute Disease↗
PubMed1986

Reduced cerebral blood flow in high altitude climbers.

Cerebral blood flow (CBF) was studied by 133Xe inhalation dynamic single photon emission computer tomography in 8 members of a climbing expedition to the Himalayas. With one exception they had all previously climbed at high altitudes. All stayed above 6,500 m for approximately 3 weeks, and 5 reached the summit of Mt. Everest. CBF was measured in Oslo before, immediately after, and one year after the completion of the expedition. Measurements were made at rest and following the injection of 1 g acetazolamide intravenously. As reference group was used 13 healthy male subjects of similar age from the hospital staff. Ten age-matched male diving instructors formed a second control group. In the climbers a small, but not significant reduction in CBF was seen after the expedition. On the other hand, they had significantly lower CBF than reference subjects already before the expedition. The flow difference was most pronounced corresponding to the perfusion territory of the middle cerebral artery. One year after the completion of the expedition the average CBF in climbers was still more than 15% lower than in the reference group. The climbers had higher relative flow increase after acetazolamide injection than the reference subjects, showing that the functional capacity of the microvascular system of the brain was intact. Whether neuronal activity or number of neurones is reduced in climbers proportional to the decrease in flow, or maintained at normal level by increased oxygen and glucose extraction, cannot be answered by the present data.

Acclimatization↗
PubMed1986

Measurement of cerebral blood flow with 133Xe inhalation and dynamic single photon emission computer tomography. Normal values.

Cerebral blood flow (CBF) was studied by 133Xe inhalation tomography in 25 healthy subjects. Mean age was 41 years and range 23-66 years. Mean hemispheric CBF at rest was 59.8 ml/100 g/min, and cerebellar flow 60.8 ml/100 g/min. This difference was not statistically significant. The distribution of CBF values was skewed and approximated a log normal distribution. Estimated lower and upper normal reference range limits calculated as mean (log) +/- 2 S.D. (log) were 47-74 ml/100 g/min. Women had approximately 5 ml/100 g/min higher CBF values than men. This difference corresponded to the difference in hematocrit. Neither in men nor in women was there any tendency to age dependent reduction or increase in flow. In both sexes hemispheric regional CBF (rCBF) was asymmetric with higher flow values in the right cerebral hemisphere; particularly in the anterior distribution territory of the middle cerebral artery. In this region the maximum individual flow difference was 8 ml/100 g/min and the average difference 3.5 +/- 2.6 ml/100 g/min. Emotional activation as a consequence of the study conditions is assumed to be the cause of this observed asymmetry. Cerebellar flow was not assymetric. No significant difference in cerebellar or hemispheric CBF was found when a second study followed the first by 3-15 months. PCO2 correction of flow improved the reproducibility. The standard deviation of the flow difference between test/retest measurements was 5 ml/100 g/min. After 1 g acetazolamide given intravenously the mean increase in hemispheric CBF was 15.7 +/- 5.1 ml/100 g/min.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetazolamide↗
PubMed1985

A comparison of pulsed Doppler spectral analysis and intravenous digital subtraction angiography in the detection of carotid occlusive disease.

The purpose of this study was to compare the accuracy of pulsed Doppler spectral analysis and intravenous digital subtraction angiography (IVDSA), in the detection of carotid occlusive disease. In 132 carotid arteries the results of these two examinations have been assessed independently and compared with findings by conventional arteriography. All 39 stenoses causing a diameter reduction of more than 25% were found by Doppler examination and 36 (92%) by IVDSA. Twelve occlusions of the internal carotid artery, shown by conventional arteriography, were also detected by Doppler examination and 11 (92%) by IVDSA. Both Doppler and IVDSA detected 56% of the lesions which reduced the diameter by less than 25%. All 54 arteriographically normal vessels were assessed correctly by Doppler examination and 53 (98%) of them by IVDSA. This study shows that Doppler and IVDSA are well suited for assessing patients with symptoms suggestive of carotid occlusive disease, both methods being accurate in the detection of lesions which reduce the diameter of the carotid artery by more than 25%.

Carotid Artery Thrombosis↗
PubMed1985

Psychiatric diagnosis and the oppression of women.

The system of psychiatric diagnosis which has recently been adopted by most western countries has features, which in various ways, work against the interests of women. This is important as the diagnostic scheme is not a theoretical work which will lay gathering dust on the bookshelves in medical libraries, it is a practical tool which forms the basis for the categorization of 'the insane'. Once the label has been assigned, it is then quite likely that the person labelled will be encouraged or even forced to have certain treatments. This may cause disquiet if the initial labelling is suspect. The purpose of this article is to reveal problems lurking beneath the surface of this moderately bland-looking system of psychiatric diagnosis and to show how the Scheme may help perpetuate the oppression of women.

Adjustment Disorders↗
PubMed1984

Reproducibility of Doppler aortic blood flow measurements: studies on intraobserver, interobserver and day-to-day variability in normal subjects.

Doppler aortic flow velocity measurements have been used to assess quantitatively left ventricular performance at rest and after pharmacologic and other hemodynamic interventions. To permit more meaningful interpretation of Doppler data, 10 normal subjects were studied to establish the intraobserver, interobserver and day-to-day variability in Doppler aortic flow velocity measurements. In each subject, pulsed Doppler recordings of ascending aortic flow velocity were obtained from the suprasternal notch on 2 different days (mean interval 6 days), with the same technician performing and same physician reading both Doppler studies to evaluate day-to-day variability of measurements. Interobserver variability was assessed by having 2 observers read each Doppler study. Both observers read the Doppler records from both days again at a second session to determine intraobserver variability. Intraobserver variability ranged from 1.9 +/- 1.8 to 3.2 +/- 2.9% for ejection time, peak flow velocity and flow velocity integral, but was higher for acceleration time (7.9 +/- 6.6%). Interobserver variability ranged from 3.5 +/- 2.2 to 5.4 + 3.4% for peak flow velocity, ejection time and flow velocity integral, but was notably higher for acceleration time (17 +/- 9%). Day-to-day variability was higher for acceleration time (7.0 +/- 5.2%) than for ejection time, peak flow velocity and flow velocity integral (range from 3.6 +/- 3.1 to 5.2 +/- 4.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Social and emotional loneliness: an examination of Weiss's typology of loneliness.

This study examined Weiss' conceptualization of social and emotional loneliness. Using data from an extensive survey of undergraduate and graduate students at the University of Iowa, we measured social and emotional loneliness, students' affective and behavioral reactions to loneliness, students' social relationships, and their judgments of the degree to which their relationships supply the six social provisions described by Weiss. As expected, we found differences in the subjective experiences of social and emotional loneliness, although both forms of loneliness were also characterized by a common core of experiences. The results generally supported Weiss's ideas concerning the determinants of social and emotional loneliness. Predictions concerning the affective and behavioral consequences associated with each type of loneliness, however, were only partly supported, although the two forms of loneliness were associated with different affective reactions and coping behaviors. The implications of these findings for Weiss's typology of loneliness are discussed.

Adult↗
PubMed1984

Chronic paroxysmal hemicrania: severity, duration and time of occurrence of attacks.

A detailed clinical study of 105 CPH attacks in five patients has been carried out. Data were recorded during periods when patients were without medication and with the use of methods which were not dependent on the patients' memory of events. When overall assessments of symptoms during the study period were mild or moderate the attack frequency was from 4 to 8, mean 6.5 attacks per 24 h. However, when overall assessments of symptoms were described as severe or extremely severe the attack frequency was from 13 to 38, mean 21.8 attacks per 24 h. The mean duration of attacks was 13.3 +/- 7.6 min. No nocturnal preponderance of attacks was found.

Adult↗
PubMed1984

Chronic paroxysmal hemicrania: heart rate changes and ECG rhythm disturbances. A computerized analysis of 24 h ambulatory ECG recordings.

Ambulatory ECG recordings have been carried out in five patients suffering from CPH. During the study a total of 105 attacks occurred. Contrary to findings in cluster headache, no typical pattern of heart rate change was found in association with attacks of CPH. A striking finding in all patients, however, was that there were often large and rapid variations in heart rate which could be observed "before", "during" or "after" the attacks. One patient developed bradycardia and sino-atrial block and another bundle branch block together with episodes of atrial fibrillation in association with attacks.

Adult↗