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Biomedical subjects

M Fredrikson

Publications and source records attributed to M Fredrikson.

At least 91 records · Page 5Linked to original sources
PubMed1993

Health behavior, knowledge and attitudes among Swedish university students.

A range of health behaviors was related to beliefs concerning health practices and health knowledge. A questionnaire dealing with health-related practices, health beliefs and knowledge of health risk factors was answered by 166 male and 179 female students aged 18-30 years at Stockholm University. Female students reported engaging in better health behavior than males. Beliefs about the importance of health behaviors were closely related to their frequency of occurrence. There was only a weak relationship between health behaviors and knowledge of specific health matters. It is concluded that health attitudes rather than health knowledge determine health behavior.

Adolescent↗
PubMed1993

Conditioned nausea after cancer chemotherapy and autonomic nervous system conditionability.

There are marked individual differences in conditioned nausea after cancer chemotherapy. To examine if part of this variation is associated with individual differences in autonomic nervous system conditionability, the present study addressed whether patients with conditioned nausea acquired conditioned heart rate and electrodermal responses at a different rate than patients without conditioned nausea. Of 28 relapse-free patients who had completed cisplatinum treatment for testicular cancer between 1981 and 1986, 10 reported persistent conditioned nausea, 8 extinguished conditioned nausea and 10 no conditioned nausea. These three groups were subjected to a differential conditioning paradigm with 8 sec pictorial stimuli (circles and triangles) serving as conditioned stimuli for an unconditioned electric shock while heart rate and electrodermal activity was monitored. There were 4 habituation, 8 acquisition and 8 extinction trials with each of the two cues. Analyses of variance using nausea status as the independent variable and physiological responses as the dependent lended some support to the notion that conditioned heart rate deceleration developed in response to the reinforced compared to the nonreinforced cue during acquisition in the two groups with persistent or extinguished conditioned nausea but not in the group with no conditioned nausea. In addition, patients that displayed good, as compared to poor heart rate conditionability during acquisition, were more likely to have persistent conditioned nausea, whereas those who showed poor heart rate conditioning mostly were those without conditioned nausea. Electrodermal variables revealed no systematic differences between groups. This tentatively supports that individual differences in parasympathetic but not sympathetic nervous system conditionability may be associated with individual differences in conditioned nausea resulting from cancer chemotherapy.

Adult↗
PubMed1993

Regional cerebral blood flow during experimental phobic fear.

Positron emission tomographic measurements of regional cerebral blood flow (rCBF) were used to investigate central nervous system correlates of fear and anxiety. Volunteers with symptomatic snake phobia were studied while exposed to visual phobogenic, aversive, and neutral stimuli. Anxiety ratings and the number of nonspecific electrodermal fluctuations increased as a function of phobic stimulation. Phobic, compared to neutral and aversive, stimulation elevated rCBF in the visual associative cortex. The basal ganglia were not activated more by phobic than aversive or neutral stimulation. However, cortical and thalamic rCBF were always correlated during phobic but not aversive or neutral stimulation. This indicates that the thalamus could be a relay station for phobic stimulus processing and affect.

Adult↗
PubMed1992

Control of cisplatin induced emesis--a multidisciplinary intervention strategy.

A pharmacological, behavioural and nursing intervention strategy was evaluated for prevention of cisplatin (50 mg m-2) induced emesis in ovarian cancer patients. 46 patients received metoclopramide 2.5 mg kg-1 i.v., b.i.d., dexamethasone 20 mg i.v., lorazepam and biperiden as well as training in relaxation, nutritional advice and continuity in nursing care. Controls (n = 34) received standard treatment (metoclopramide 10-20 mg i.v. or dixyracin 20 mg i.v.). The intensity and duration of nausea and vomiting were significantly lower and measures of quality of life higher for patients on the experimental ward during the three cycles that were studied. No significant changes in emesis were observed between the cycles. There was no correlation between emesis and any of the parameters of quality of life measured. The reliability and validity of nausea ratings are discussed and we suggest that an underreporting of nausea and vomiting might be common.

Adult↗
PubMed1992

Psychobiology of stage fright: the effect of public performance on neuroendocrine, cardiovascular and subjective reactions.

Subjective, neuroendocrine and cardiovascular functions were studied in high- and low-anxious musicians performing privately and publicly. Musicians were designated as "high-anxious" if they reported at least one episode of performance-related tremor and as "low-anxious" if they never had experienced tremor while performing in public. All musicians performed privately and publicly while measurements of subjective, neuroendocrine and cardiovascular functions were made. Ratings of effort and distress were made prior to performance. Heart rate was monitored telemetrically before, during and after performance. Urinary epinephrine, norepinephrine and cortisol were sampled after public and private performance, respectively. Situational factors influenced most measures. Epinephrine, norepinephrine, cortisol, heart rate and ratings of distress but not effort increased from private to public performance. Heart rate was higher in high- than in low-anxious musicians during public performance but similar during private performance. The increase in neuroendocrine activation from private to public performance was similar in the high- and low-anxious groups. It is concluded that heart rate is a sensitive measure of both situational and individual determinants of performance-related distress.

Achievement↗
PubMed1992

Serum lipids, neuroendocrine and cardiovascular responses to stress in healthy Type A men.

This study examined the relationship between serum lipid activity in healthy Type A men and cardiovascular and neuroendocrine responses to a behavioral stressor, mental arithmetic. Assessment of blood lipids included measures of total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and serum triglycerides. Cardiovascular (blood pressure and heart rate) and neuroendocrine (epinephrine, norepinephrine and cortisol) responses were recorded before (rest), during (stress) and after (recovery) the mental arithmetic test. Diastolic blood pressure, mean arterial pressure and, to a lesser extent, systolic blood pressure levels at rest, during stress, and at recovery correlated positively with TC levels. In addition, both diastolic and mean arterial pressure were positively correlated with the ratio of TC to HDLC and with triglycerides during stress and recovery. Heart rate did not correlate with any lipid measure. Cardiovascular stress-reactivity calculated as change from rest to stress did not correlate significantly with any lipid measure. Plasma norepinephrine during stress correlated positively with triglycerides; a similar trend was observed for the TC/HDLC ratio. Plasma cortisol at rest and during stress correlated positively with the TC/HDLC ratio and serum triglycerides, and negatively with HDLC. Plasma norepinephrine reactivity calculated as change from rest to stress correlated negatively with HDLC and positively with triglycerides. In addition, cortisol reactivity was positively correlated with triglycerides. It is suggested that the mechanisms mediating Type A behavior and coronary heart disease may include increased cardiovascular and neuroendocrine responses as well as unfavorable lipid profiles.

Adult↗
PubMed1992

Blood pressure reactivity to active and passive behavioral conditions in hypertensives and normotensives.

Blood pressure reactivity and passive behavioral tasks was studied in patients with mild essential hypertension and normotensive controls. The passive condition included 10 presentations of a 6 sec, 78 dB, 1000 Hz tone without any response requirements. In the active condition subjects were given an additional 10 tone presentations and asked to press a push-button at tone termination. The absolute and percent increase in systolic blood pressure from rest was greater in hypertensives than normotensives in response to the active condition but similar to the passive condition. It is concluded that patients with hypertension compared to normotensive controls show exaggerated blood pressure reactivity to tasks involving active but not passive coping efforts. Since the tasks used to induce active and passive coping in the present study were identical apart from coping requirements, the notion that the activity dimension in and of itself modulates reactivity differences between patients and controls is supported.

Adaptation, Psychological↗
PubMed1992

Aspects of patient care. Interviews with relapse-free testicular cancer patients in Stockholm.

Thirty-nine relapse-free testicular cancer patients were interviewed 1-6 years after completion of chemotherapy, in connection with a study of conditioned nausea. Some structured questions about experiences of diagnosis and treatment were included, but this report also summarizes spontaneously given information. The patients' first contact with a treatment setting appears to be an important determinant of the overall treatment experience. If resources are limited, they are used effectively if concentrated during the initial contact with the patient. Support from relatives and friends was reported as good for 90% of the men during treatment. Thirty-two distressing factors during the treatment period were mentioned; the most severe were nausea and vomiting. Other high-ranking factors were "being restricted for the infusion" and "the smell of food." There is a need for flexibility in ways to prepare and serve food on the ward. Some men argued for more information concerning the disease and chemotherapy; others said they received too much information. Several men suggested that a debriefing talk with the physician and someone from the staff should be arranged 6 months to 1 year after completion of treatment.

Adult↗
PubMed1991

Stress reactivity and exercise training in premenopausal and postmenopausal women.

Examined the influence of ovarian function on psychophysiological stress responses and determined if aerobic exercise reduced stress reactivity. Fifty premenopausal and postmenopausal women initially were subjected to a public speaking task and an ice-on-the-forehead procedure, during which time their blood pressure and heart rate were monitored and continuous blood samples were obtained. Subjects also underwent aerobic fitness evaluations with a maximum-exercise treadmill test. Subjects were then randomly assigned to a 12-week exercise program of either aerobic exercise (e.g., walking and jogging at a prescribed exercise intensity) or non-aerobic strength and flexibility training and were then reevaluated. Results indicated that postmenopausal women exhibited lower resting epinephrine levels but greater epinephrine reactivity to the speaking task compared to the premenopausal women. There were no differences between premenopausal and postmenopausal women with respect to cardiovascular or catecholamine responses during the cold challenge. Premenopausal and postmenopausal women also achieved comparable improvements in aerobic fitness. However, results of the mental stress testing were complex and provided only partial support for the role of aerobic exercise in reducing stress responses.

Arousal↗
PubMed1991

Blood pressure and heart rate variability and reactivity as related to daily activities in normotensive men measured with 24-h intra-arterial recording.

The effect of blood pressure and heart rate reactivity on respective variability in everyday life conditions was studied in a group of middle-aged, normotensive men (n = 22, mean age 39.3 years, range 35-45 years). Continuous intra-arterial tape recording was used to measure 24-h blood pressure and heart rate and the subjects completed a 24-h behavioural diary. The variability of blood pressure and heart rate was analysed using 30-s averages and cumulative distribution curves. The overall blood pressure and heart rate variability was calculated as the difference between the 90 and 10% levels of the cumulative distribution curves. Reactivity caused by different daily activities was calculated as the change from baseline level, defined as the 10% level determined from the cumulative distribution curve of waking hours. All regular activities were monitored. Large interindividual differences were found in variability and reactivity. The mean reactivity to different activities varied from 3.3 to 44.7 mmHg for systolic blood pressure, from 1.8 to 16.3 mmHg for diastolic blood pressure and from 2.0 to 46.0 beats/min for heart rate. The mean contribution of reactivity to variability varied between 21 and 74% for systolic blood pressure, from 19 to 58% for diastolic blood pressure and from 20 to 82% for heart rate. As expected, blood pressure and heart rate levels were significantly higher at work than at home. We conclude that the reactivity caused by daily activities has a pronounced influence on blood pressure level and variability during waking hours.

Activities of Daily Living↗
PubMed1991

Psychophysiological theories on sympathetic nervous system reactivity in the development of essential hypertension.

Psychophysiological theories on the development of essential hypertension are reviewed and evaluated. Two interconnected theories that relate behavior to essential hypertension and account for individual differences in susceptibility to disease are the "hyperreactivity" theory and "the symptom specificity" theory. The "hyperreactivity" theory identifies individual differences in autonomic nervous system reactivity as the pathophysiological mechanism and the "symptom specificity" theory suggests that inflexible, stereotypical responding increases the risk to develop hypertension. Based on a literature review, these theories are examined. There exist both case/control and prospective studies on autonomic nervous system reactivity and the development of hypertension. It is concluded that a neurogenically mediated hyperreactivity to stress is a precursor and not an effect of hypertension. Tasks that call for active but not passive coping efforts are more efficient elicitors of reactivity differences between those at high and low risk to develop hypertension in case/control studies. In prospective studies, active tasks may also have a predictive advantage over passive with respect to blood pressure development. In the early phase of hypertension, an increased cardiovascular reactivity is accompanied by increased neuroendocrine activation. In the later phase, heightened reactivity is confined to the cardiovascular system. This does not prove but is consistent with the notion that transient episodes of increased cardiac output translate into essential hypertension by causing vascular hypertrophy. Case/control studies suggest that an increased "symptom specificity", with stereotypical responding across multiple stressors, is independent of cardiovascular reactivity and a precursor of hypertension. The literature lacks prospective studies on the clinical relevance of stereotypical responding. It is suggested that the presence of both hyperreactivity and symptom specificity in a single individual increases the risk to develop essential hypertension.

Arousal↗
PubMed1991

Ambulatory and laboratory blood pressure in individuals with negative and positive family history of hypertension.

Undertook 24-hr ambulatory blood pressure (BP) monitoring in men and women with and without family history of essential hypertension. Cardiovascular functions were also recorded in the laboratory during mental arithmetic, image star tracing, isometric exercise, and the cold pressor test. Ambulatory daytime, but not nighttime, systolic and diastolic BP as well as heart rate (HR) level and variability was higher in those with than without family history. During sleep, HR level and variability were higher among those with family history; at rest in the laboratory, however, all cardiovascular functions were similar in both groups. The strongest laboratory-based predictor of daytime BP was stress-induced BP levels. BP reactivity also significantly predicted daytime BP but with less accuracy. The best predictor of BP and HR at sleep was resting cardiovascular functions. Thus, ambulatory BP recordings add information to resting and stress-induced levels in identifying cardiovascular risk reactions.

Adult↗
PubMed1990

Soft tissue sarcoma and occupational exposures.

The associations between soft tissue sarcoma (STS) and occupational exposures were studied in a case-referent study in the southeast of Sweden. Exposure information was obtained through mailed questionnaires to 96 cases, 450 randomly selected population referents, and 200 cancer referents. Odds ratios (OR), were calculated for various occupational groups, and particularly, for occupations with potential exposure to chlorinated phenoxy herbicides and chlorophenols. In the analyses based on population referents, increased risks for soft tissue sarcoma were seen for especially gardeners (OR = 4.1), but also railroad workers (OR = 3.1); construction workers with exposure to impregnating agents (OR = 2.3), asbestos (OR = 1.8), or pressure impregnating agents (OR = 1.7); and unspecified chemical workers with potential exposure to phenoxy herbicides and/or chlorophenols (OR = 1.6). A similar pattern appeared when cancer referents were used although the numerical values of the odds ratios became different. A grouping of jobs resulted in Mantel-Haensel OR from 1.5 to 1.9 for farmers and forestry workers, dependent on referents used and even more increased OR for railroad workers and unspecified chemical workers with potential exposure to phenoxy herbicides and chlorophenols. The results of the study confirm rather than refute that phenoxy herbicides and chlorophenols could be of etiologic importance for STS; the high risk for gardeners, although based on a small number of individuals, was unexpected and remains unclear. Also, since other cancers were used as referents, no definite problems of recall bias should obtain in this material. None of the exposed groups had a higher proportion of smokers than the unexposed group.

Adult↗
PubMed1990

Aerobic exercise reduces levels of cardiovascular and sympathoadrenal responses to mental stress in subjects without prior evidence of myocardial ischemia.

Thirty-seven healthy type A men (mean age 42 years) were randomly assigned to either an aerobic exercise training group or to a strength and flexibility training group. Before exercise, subjects underwent comprehensive physiologic and behavioral assessments, including graded exercise treadmill testing with direct measurement of oxygen consumption (VO2) and measurement of cardiovascular (heart rate, systolic and diastolic blood pressure and rate pressure product) and neuroendocrine (epinephrine and norepinephrine) responses to mental arithmetic. The aerobic exercise consisted of walking and jogging at an intensity of greater than or equal to 70% maximal heart rate reserve for 1 hour 3 times/week for 12 consecutive weeks. The strength training consisted of 1 hour of circuit Nautilus training 2 times/week for 12 weeks. At the completion of the exercise program, all subjects underwent repeat testing. For the aerobic group, peak VO2 increased significantly from 33.6 to 38.4 ml/kg/min (p less than 0.001), whereas the strength group only achieved a slight increase from 34.5 to 35.6 ml/kg/min (difference not significant). During the mental arithmetic, the aerobic group experienced a greater reduction in levels of heart rate, diastolic blood pressure and rate pressure product than the strength group (after completing the exercise training programs). The aerobic group also tended to secrete less epinephrine and to show a faster recovery than the strength group after the exercise program. In addition, the aerobic group tended to exhibit less cardiovascular reactivity to mental stress after exercise training. These data suggest that aerobic exercise reduces levels of cardiovascular and sympathoadrenal responses during and after mental stress.

Adrenal Medulla↗
PubMed1990

Blood pressure in healthy men and women under laboratory and naturalistic conditions.

Thirty healthy nonsmoking men and 30 women underwent a laboratory reactivity assessment with systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) recorded at rest and during behavioral (mirror image tracing, mental arithmetic, color word conflict task and a semistructured Type A interview), and physical tasks (isometric exercise and the cold pressor test). Causal SBP and DBP were measured in a physician's clinic. Four months earlier SBP, DBP and HR had been monitored during a day at work and a day at home. Readings obtained in the clinic, at rest and during stress in the laboratory were related to real-life levels, reactivity (work-home difference) and variability. For men level of cardiovascular activation at rest and during all stressors in the laboratory correlated with levels at work and at home. The best laboratory/real-life relation was observed for SBP. Systolic blood pressure levels during stress correlated with the work-home difference. Systolic blood pressure reactivity (laboratory stress levels - rest levels) to most behavioral tasks correlated with SBP levels at work and home. Daily variability and reactivity correlated with SBP reactivity to mental arithmetic and the color word conflict task. For women, levels of SBP and HR at rest and during all stressors correlated with SBP and HR at work and at home. The best laboratory/real-life relation for women was observed for HR reactivity. Casual BP in the clinic correlated with work blood pressure but generally not with daily reactivity or variability. We conclude that BP and HR levels measured in the laboratory generalizes to real life BP and HR in both men and women and also to real life SBP reactivity in men. Laboratory induced SBP reactivity also shows a weak relation to real life SBP levels, variability and reactivity in men.

Adult↗
PubMed1990

Comparison of neuroendocrine measurements under laboratory and naturalistic conditions.

Urinary catecholamines and cortisol were measured in healthy nonsmoking white collar workers (14 male and 15 female managers, 15 male and 14 female clerical workers), aged 30-50 years, during a one-hour period of laboratory-induced stress comprising five tests and a Type A interview, and during a subsequent period of rest in the laboratory. Values were compared with data obtained four months earlier from the same subjects during a normal day at work (4 values) and during a work-free day at home (4 values). No significant group differences were found during rest in the laboratory. However, during laboratory-induced stress, female managers had the highest norepinephrine values, which contributed to significantly (p less than 0.01) higher values in women than in men. Correlations between absolute measurements from laboratory and naturalistic conditions were generally positive and reached significance in most cases. Correlations between reactivity measurements in the laboratory and at work (change from rest to stress and from home to work, respectively) were generally low, whereas correlations between reactivity at different times of the day were relatively high. The data suggest that generalizability of neuroendocrine reactivity from laboratory stress to real-life stress is low. However, in agreement with earlier experimental findings, absolute levels of catecholamine and cortisol excretion were consistent over conditions and time.

Adult↗