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Biomedical subjects

M Fredrikson

Publications and source records attributed to M Fredrikson.

At least 73 records · Page 4Linked to original sources
PubMed1996

Stress-induced laboratory blood pressure in relation to ambulatory blood pressure and left ventricular mass among borderline hypertensive and normotensive individuals.

Our primary aim in the present study was to investigate the association between blood pressure measured in the laboratory and in the ambulatory state in a group of middle-aged borderline hypertensive men and age-matched normotensive control subjects. In addition, we examined the relation between stress-induced blood pressure measurements and left ventricular mass. Blood pressure and heart rate were measured noninvasively during a standardized laboratory stress protocol and four times per hour throughout 24 hours. Borderline hypertensive subjects had significantly higher systolic and diastolic pressures than normotensive subjects during both the daytime (systolic pressure, 141.1 +/- 9.7 versus 130.9 +/- 8.6 mm Hg; diastolic pressure, 88.8 +/- 7.0 versus 79.4 +/- 6.2 mm Hg, P < .001) and nighttime (systolic pressure, 114.0 +/- 9.9 versus 107.1 +/- 8.3 mm Hg; diastolic pressure, 71.5 +/- 7.5 versus 64.6 +/- 7.2 mm Hg, P < .001). The borderline hypertensive group also displayed increased systolic pressure reactivity in the laboratory compared with the normotensive group. The groups did not differ significantly in left ventricular mass (index). In both borderline hypertensive and normotensive individuals, blood pressure levels during stress testing were closely related to ambulatory blood pressure levels (r = .51 to .82). Furthermore, stress-induced blood pressure levels were significantly correlated to left ventricular mass in borderline hypertensive (r = .33 to .40) but not normotensive subjects. Since stress-induced blood pressure levels were significantly associated with both ambulatory blood pressure levels and left ventricular mass in borderline hypertensive subjects, the addition of standardized stress testing to casual blood pressure measurements may improve risk estimation.

Adult↗
PubMed1996

Cerebral correlates of anticipated fear: a PET study of specific phobia.

Cerebral correlates of anticipatory anxiety was studied in 14 women with specific snake or spider phobia, and in 6 nonphobic controls. Videofilms with neutral scenes were shown during positron emission tomographic measurements of regional cerebral blood flow (rCBF). The phobics, but not the controls, anticipated scenes with spiders or snakes to appear in the videofilms. This was reflected in higher anxiety ratings in the phobics. The primary visual cortex rCBF was lower in phobics than controls, while no rCBF differences were found in the other brain regions investigated. The results are suggested to indicate inhibition of corticogeniculate pathways, in turn representing a neurophysiological correlate of avoidant anticipatory coping.

Adaptation, Psychological↗
PubMed1996

Social support and immune status during and after chemotherapy for breast cancer.

Social support and immune status were assessed in women treated with adjuvant chemotherapy for breast cancer. Perception of enhanced attachment was associated with an increased number of white blood cell levels three months after, but not during, chemotherapy. After treatment, patients with high attachment ratings had higher numbers and proportions of granulocytes, and lower proportions of lymphocytes and monocytes. It is concluded that the support experienced by a cancer patient can be associated with counts and proportions of leukocytes, but that this effect, if present during chemotherapy, is overridden by the biological factor that affects the haematopoetic process.

Age Factors↗
PubMed1995

Affective and attentive neural networks in humans: a PET study of Pavlovian conditioning.

Using positron emission tomography (PET) and [15O]butanol we studied regional cerebral blood flow (rCBF) to a visual snake stimulus before and after classical conditioning with an unconditioned electric shock delivered to the right hand. Measures of heart rate, electrodermal activity, state anxiety and subjective distress confirmed classical conditioning of physiological and subjective responses. Subcortically, conditioning increased rCBF bilaterally in the ventromedial thalamus, the posterior hypothalamus and the central grey of the midbrain. Cortically, rCBF increased in the left anterior and posterior cingulate gyrus, the left primary somatosensory cortex, the left premotor cortex and bilaterally in parietal areas. Thus, the functional organization of classical conditioning in humans involves autonomic, affective and attentive brain mechanisms.

Adult↗
PubMed1995

Decreased sexual capacity after external radiation therapy for prostate cancer impairs quality of life.

PURPOSE: The aim of this study was to assess to what extent patients treated with radiation therapy for prostate cancer experience change in sexual functioning and to what extent this effects quality of life. METHODS AND MATERIALS: Information was provided by 53 men treated with radiation therapy for localized prostate cancer. Assessment was made with the "Radiumhemmets Scale of Sexual Functioning," which measures sexual desire, erectile capacity, orgasm, and to what extent a decrease in any of these aspects of sexual functioning affects quality of life. Function before treatment was assessed retrospectively. RESULTS: Sexual desire diminished among 77% after treatment. The erection stiffness decreased in 77%. Before external radiation therapy, 66% had an erection usually sufficient for intercourse. Half of the men lost this ability after treatment. Of those retaining orgasm after treatment, 47% reported a decreased orgasmic pleasure and 91% a reduced ejaculation volume. Of all men, 50% reported that quality of life had decreased much or very much due to a decline in the erectile capacity following external radiation therapy. CONCLUSION: The results of the present study indicate that external radiation therapy for prostate cancer is associated with a reduction in sexual desire, erectile capacity, and organism functions. In a majority of patients this reduces quality of life. Previously, we may have underestimated the importance an intact sexual function has for the quality of life in this patient category of elderly men.

Aged↗
PubMed1995

Occupational and other risk factors for clinically overt familial amyloid polyneuropathy.

Amyloidosis is associated with the deposition of amyloid substance in various tissues of the body. In several forms of familial amyloid polyneuropathy, mutated transthyretin is the main fibril component. The disease is inherited as an autosomal dominant trait with onset in adult life, but few carriers develop symptoms. The aim of the present investigation was to screen for additional factors that might be necessary for the development of familial amyloid polyneuropathy. We conducted a case-control study involving 51 male and 30 female cases of clinically overt familial amyloid polyneuropathy and 306 male and 317 female population controls. We considered occupational exposures, disease histories, and medical treatments as potential determinants of risk for clinically overt disease. We found an odds ratio of 5.4 for dressmakers. Low and high levels of exposure to organic solvents resulted in an odds ratio of 2.1 and 11.8, respectively. A history of prostatic hyperplasia, cholecystic disease, or appendectomy was also a risk factor, possibly as a consequence of anesthesia.

Adult↗
PubMed1995

Adipose tissue concentrations of dioxins and dibenzofurans in patients with malignant lymphoproliferative diseases and in patients without a malignant disease.

Concentrations of dioxins (PCDD) and dibenzofurans (PCDF) were analysed in adipose tissue from seven patients with malignant lymphoproliferative diseases and 12 surgical patients without a malignant disease. All cases in the first group had reported potential exposure to PCDD and PCDF. Of the analysed congeners significantly higher concentrations of 1,2,3,7,8-pentachlorodioxin, 1,2,3,6,7,8-hexachlorodioxin, and 2,3,4,7,8-pentachlorodibenzofuran were found in the cases with lymphoproliferative diseases compared with the patients in the other group. Higher mean concentration of 2,3,7,8-TCDD was also found in the first group but not significantly so. Toxic equivalents of PCDD and PCDF were significantly higher in the first group (mean 64.7 pg/g, range 19.9-187) than in the second group (mean 29.7 pg/g, range 12.9-53.4). Even if the cases with lymphoproliferative diseases in this case series were potentially exposed to PCDD/PCDF in contrast to the other group, the observed differences may be of may be of interest in relation to the aetiology of these malignancies. Immunosuppression increases the risk for malignant lymphoproliferative diseases, and PCDD/PCDF have established immunotoxic properties.

Adipose Tissue↗
PubMed1995

Structural cardiac changes in relation to 24-h ambulatory blood pressure levels in borderline hypertension.

OBJECTIVES: To investigate left ventricular hypertrophy (LVH) in relation to 24-h ambulatory blood pressure (24-ABPM) and insulin levels in borderline hypertension. DESIGN: A case-control study. SUBJECTS: Borderline hypertensive men (diastolic blood pressure (DBP) 85-94 mmHg, n = 69) and age-matched normotensive controls (DBP < or = 80 mmHg, n = 69) from a population screening programme. MAIN OUTCOME MEASURES: Echocardiography (M-mode), insulin (RIA) and 24-APBM (Del Mar P-IV) levels. RESULTS: The borderline group showed a significant increase in septal thickness (10.4 +/- 1.5 vs. 9.7 +/- 1.5 mm, P < 0.01), peak systolic wall stress (218 +/- 38 vs. 202 +/- 38 10(3) dynes cm-2, P < 0.05) and a decrease in LV ejection time (28.4 +/- 2.5 vs. 29.5 +/- 2.1s, P < 0.01). The septum vs. posterior wall thickness ratio was significantly higher in the borderline group (1.13 +/- 0.14 vs. 1.06 +/- 0.14, P < 0.01). Casual BP levels did not correlate with LVH indices, while 24-ABPM systolic levels correlated strongly with LVH indices in the borderline group (r = 0.22-0.52, P < 0.05) but not in the normotensive group. Insulin levels correlates strongly with LVH indices in the normotensive group (r = 0.34-0.47, P < 0.01) but not the borderline, group. CONCLUSIONS: Signs of asymmetric LVH and altered ventricular function are already detectable in borderline hypertension. The data also suggest that early structural cardiac changes are related to ambulatory blood pressure profile, but not to casual blood pressure or trophic factors such as insulin.

Adult↗
PubMed1995

Functional neuroanatomy of visually elicited simple phobic fear: additional data and theoretical analysis.

We investigated central nervous system correlates of simple phobic fear. Regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) in eight volunteers with symptomatic spider phobia that were exposed to visual phobogenic and neutral stimuli. Diazepam (0.1 mg/kg body weight i.v.) or placebo was administered under double-blind conditions after initial PET scans. The PET scans were then repeated. The presence of fear was confirmed by rating procedures and increased number of nonspecific electrodermal fluctuations and by higher heart rate during phobic than during neutral stimulation. Phobic as compared to neutral stimulation elevated the regional to whole brain (relative) CBF in the secondary visual cortex but reduced relative rCBF in the hippocampus, prefrontal, orbitofrontal, temporopolar, and posterior cingulate cortex. Diazepam treatment did not affect the relative rCBF or the subjective or physiological fear indices. The observed rCBF pattern replicates our previous findings in snake phobics (M. Fredrikson et al. [1993] Psychophysiology, 30, 127-131; G. Wik et al. [1993] Psychiatry Research (Neuroimaging), 50, 15-24) and indicates that fear and anxiety affect cortical areas outside the classic limbic system areas.

Adult↗
PubMed1995

Prognostic information from on-line vectorcardiography in unstable angina pectoris.

The prognostic information from 24-hour monitoring with on-line vectorcardiography (VCG) was assessed in 100 patients with a clinical diagnosis of unstable angina pectoris. ST change vector magnitude, ST vector magnitude and QRS vector difference were monitored. During a follow-up period of 343 +/- 77 days, 7 patients died from cardiac causes and 8 patients had a nonfatal myocardial infarction (MI). Thirty patients were readmitted for unstable angina pectoris and 36 were revascularized because of medical refractory angina. Univariate predictors of cardiac death or nonfatal MI included greater age, rest pain during hospitalization, previous MI, diabetes mellitus and high incidence of supposedly ischemic transient ST and QRS vector changes. In multivariate analysis, a high incidence of transient ST (p < 0.01) and QRS (p < 0.01) vector changes provided additional prognostic information beyond that of clinical and exercise test data. In conclusion, VCG monitoring during the first 24 h of hospitalization for unstable angina pectoris identifies patients with increased risk of adverse cardiac events.

Aged↗
PubMed1995

Anticipatory immune changes in women treated with chemotherapy for ovarian cancer.

Immune parameters were assessed in 22 women before chemotherapy for ovarian cancer and compared with assessment made at home 2 days earlier. In the hospital, as compared to home measures, patients had a lower percentage of lymphocytes and monocytes and a higher percentage of granulocytes. Absolute numbers of lymphocytes were lower at the hospital as compared to at home. T-cell proliferative responses to concanavalin A were elevated for cells isolated from hospital blood samples as compared to home samples. The observed changes in immune parameters were not related to levels o r state anxiety at home or at the hospital. The results show anticipatory immune changes in a group of patients receiving chemotherapy that did not include cyclophosphamide.

Journal Article↗
PubMed1994

Delayed chemotherapy-induced nausea is augmented by high levels of endogenous noradrenaline.

The relation between pretreatment night-time urinary catecholamine excretion and chemotherapy-induced nausea and vomiting was studied. The first cohort included 17 women and three men with various cancer forms receiving low or moderately emetogenic chemotherapy. The second cohort included 42 women receiving cisplatinum (50 mg m-2) for ovarian cancer and ondansetron as an antiemetic (8 mg i.v. x 3 at chemotherapy and 8 mg p.o. x 3 for 5 days). Relatively higher noradrenaline, but not adrenaline, excretion was associated with an increased intensity of delayed nausea following treatment. Vomiting was not consistently related to the excretion of either catecholamine. The results indicate that noradrenaline modulates delayed nausea resulting from chemotherapy.

Adult↗
PubMed1994

Serum lipids, neuroendocrine, and cardiovascular responses to stress in men and women with mild hypertension.

In this study, we examined the relation between serum lipid levels, gender, and cardiovascular and neuroendocrine stress reactivity in patients with mild hypertension. Ninety-nine individuals (62 men, 37 women) with mild hypertension performed four mental stress tasks: mental arithmetic, public speaking, cold stress, and a computer videogame. Cardiovascular reactivity scores were computed by subtracting the minimum resting blood pressure (BP) and heart rate (HR) values from the maximum values obtained during each task. Neuroendocrine reactivity was calculated as the change from epinephrine and norepinephrine values from mean rest to mean task. High and low reactors were identified on the basis of median splits of reactivity scores, averaged across all four stressors. High systolic blood pressure reactors had higher levels of total (TC), low-density lipoprotein cholesterol (LDL-C), and apo-B than did low reactors. High diastolic blood pressure reactors had lower levels of high-density lipoprotein cholesterol (HDL-C) and higher levels of LDL-C and apo-B than did low reactors. High HR reactors had higher apo-AI:apo-AII ratios than low reactors. Lipid levels were not different for high and low epinephrine and norepinephrine reactors. Although women were noted to have more favorable lipid profiles than men, both male and female hypertensive patients who were high reactors had less favorable lipid profiles than low reactors.

Adult↗
PubMed1994

Characteristics of participating and nonparticipating men in a randomized, controlled diet and exercise intervention trial.

OBJECTIVE: To study characteristics of importance for participation in a diet and physical exercise prevention programme. SETTING: Primary Health Care, Sollentuna, and the Karolinska Hospital, Stockholm, Sweden. SUBJECTS: A sample of 187 men, aged 35-60, with increased risk factors for CHD, were invited to a 6-month prevention programme. Participants (n = 158) were randomized into a diet group, a physical exercise group, a diet and physical exercise group, and a control group. Twenty-seven men, who declined participation, formed the group of nonparticipants. DESIGN: Participants and nonparticipants were compared with respect to health beliefs, health knowledge, CHD risk factors, demographic and personality factors. MAIN OUTCOME MEASURES: Characteristics of men participating and not participating in the intervention trial. RESULTS: Nonparticipants, compared with participants, believed less in the benefits of dietary change and perceived the health threat of stroke and myocardial infarction as less serious. Nonparticipants had a better knowledge of a number of risk factors for cardiovascular disease. CONCLUSION: Belief in treatment efficacy and perceived health threat, rather than health knowledge, predicted initial participation in a non-pharmacological intervention trial.

Adult↗
PubMed1993

Trait anxiety and anticipatory immune reactions in women receiving adjuvant chemotherapy for breast cancer.

We compared peripheral blood cell counts as well as mitogen activity and natural killer-cell activity in women undergoing adjuvant chemotherapy for breast cancer in the hospital prior to chemotherapy with assessment at home 2 days earlier. Patients compared to controls had an increased number of white blood cell counts in the hospital as compared to those at home, mediated by an increased total number of granulocytes. Among patients, those with high compared to low trait anxiety evidenced immune system changes. Total number of monocytes were reduced in patients with high compared to low trait anxiety and natural killer-cell activity tended to be compromised in the high anxiety group. Helper/inducer T-cells isolated from hospital blood samples were lower in patients with high as compared to low trait anxiety, while no difference was observed in samples taken at home. Conditioned nausea was associated with trait anxiety and patients with as compared to without conditioned nausea displayed immune changes similar to changes observed as a function of trait anxiety. State anxiety measured at the hospital did not relate to immune measures. The observed increase in granulocytes is consistent with an interpretation both in terms of conditioning and anticipatory stress. The anticipatory immunosuppression in patients with high compared to low trait anxiety is consistent with the hypothesis that chemotherapy patients may develop conditioned immunosuppression after repeated pairings of treatment-related stimuli with the unconditioned immunosuppressive effect of chemotherapy.

Adult↗
PubMed1993

Internal consistency and temporal stability of classically conditioned skin conductance responses.

The reliability of classically conditioned skin conductance responses was investigated. Temporal stability was determined in 28 subjects studied three weeks apart (study 1), and internal consistency in 223 subjects studied once (study 2). A discriminative classical conditioning paradigm using slides with a duration of 8 s served as conditioned stimuli (CS) for an aversive unconditioned noise stimulus (study 1) or a mild unconditioned electric shock stimulus (UCS) (study 2). Electrodermal responses were recorded during a habituation phase (4 trials), an acquisition phase, where CS+ was paired repeatedly with the UCS, while CS- never was (8 trials), and an extinction phase during which shocks were withheld (8 trials each). First interval responses were measured 1-4 s after CS- onset during all phases of the experiment. During the acquisition and extinction phases, second interval responses were scored 5-9 s after CS- onset while third interval responses were determined 1-4 s after CS- termination. Internal consistency was significant for the first (rxy range 0.96-0.90), second (rxy range 0.84-0.54) and third (rxy range 0.96-0.86) skin conductance interval response. Temporal stability was highest for the first interval response (rxy range 0.72-0.37) and lowest for the second interval response (rxy range 0.51-0.05). It is concluded that the first interval skin conductance response shows adequate internal consistency and temporal stability to assess individual differences in classical conditioning.

Adult↗
PubMed1993

A functional cerebral response to frightening visual stimulation.

The defense reaction, a fundamental reflex in the human behavioral response to threat, is characterized by anxiety and increased activity of the sympathetic nervous system. To study changes in regional cerebral blood flow (rCBF) related to the defense reaction, volunteers with snake phobia were investigated with positron emission tomography. The relative rCBF during phobogenic visual stimulation was increased in the secondary visual cortex but reduced in the hippocampus, orbitofrontal, prefrontal, temporopolar, and posterior cingulate cortex compared with that observed during neutral visual stimulation. The relative rCBF under aversive stimulation was intermediate between phobic and neutral stimulation. The rCBF patterns observed are suggested to represent a functional cerebral correlate to the visually elicited defense reaction and its associated emotions.

Adult↗