Biofeedback-assisted relaxation: Effects on phagocytic capacity

The purpose of this study was to investigate whether subjects who self-report high levels of stress have lower immunity, and whether low-immunity subjects under high stress could enhance phagocytic activity through biofeedback-assisted relaxation (BAR). During Phase 1, the level of stress and the level of phagocytic immune functioning (nitroblue tetrazolium test) were assessed as high or low. Significant chi-square analysis (x²=3.8624, df=1, p<.05) showed that subjects with high stress had low immunity. Sixteen high-stress, low-immunity subjects were randomly assigned to BAR and control groups during Phase 2. Following treatment, NBT changes showed significant increases (F=11.11, p<.003) for experimental group as compared to control group. White blood cell count and white blood cell differential were unchanged across blood samples for both groups. Experimental subjects reported significant decreases in tension-anxiety and increases in overall coping. BAR was concluded to have improved coping skills and phagocytic capacity. BAR affected the quality, rather than the quantity, of phagocytic neutrophils.     

Altered phagocytosis by monocytes from HLA-DR2 and DR3-positive healthy adults is Fc gamma receptor specific

Fc gamma receptor-dependent mononuclear phagocyte system (MPS) clearance of opsonized erythrocytes is prolonged in healthy adults with the class II alloantigens HLA-DR2, DR3, or DQw1, despite normal receptor-specific Fc ligand binding by monocytes in these groups. To investigate the basis for the MPS dysfunction, we determined the phagocytic capacity of blood monocytes from 66 disease-free adults and analyzed the data according to the HLA type of the subjects. The data demonstrate decreased phagocytosis of IgG-sensitized erythrocytes (EA) by monocytes from HLA-DR2, DR3, or DQw1-positive subjects compared with normals without these B cell alloantigens (2.87 +/- 0.83 erythrocytes/monocyte vs 3.87 +/- 1.05, p less than 0.004; 3.01 +/- 0.94 vs 3.87 +/- 1.05, p less than 0.02; 3.18 +/- 0.89 vs 3.87 +/- 1.05, p less than 0.02, respectively). Because HLA-DR2 and DQw1 are in linkage disequilibrium, we compared EA phagocytosis in subjects with DQw1 alone to normals without HLA-DR2, DR3, or DQw1. Among subjects positive only for DQw1, no significant decrease in phagocytosis could be seen (3.46 +/- 0.95 vs 3.87 +/- 1.05, p = NS). To determine whether these differences represented an Fc receptor-specific dysfunction or a more generalized decrease in phagocytic activity, we compared the quantitative phagocytosis of EA with that of neuraminidase-treated erythrocytes (EN), which is Fc receptor independent and beta-glucan receptor mediated. No segregation of phagocytic capacity for EN by HLA class II phenotypes could be demonstrated (DR2, 2.68 +/- 1.30 erythrocytes/monocyte; DR3, 2.95 +/- 1.30; DQw1, 2.84 +/- 1.15; others, 3.06 +/- 1.14). Our data indicate that the decrease in phagocytosis by blood monocytes from normal individuals with HLA-DR2 or DR3, the class II alloantigens associated with systemic lupus erythematosus and other autoimmune diseases, is specific for the Fc receptor-mediated process. This alteration of Fc receptor function among immunogenetically defined individuals may contribute to their predisposition to autoimmune disease. These differences may also apply to other Fc receptor-initiated cellular functions.     

Changes in the leukocyte phagocytic activity of donor blood after its UV irradiation. I. Its relation to the irradiation dose and initial level of phagocytic activity

Phagocytic activity of human mono- and granulocytes increased markedly after UV blood irradiation in the apparatus "Izolda" used in hospitals of the USSR for medical treatment. With the rise of irradiation dose the ratio of cells ingesting latex particles increased, although the average number of particles ingested per cell decreased. The integrative phagocytic index poorly depended on the irradiation dose. In patients with a low initial level of phagocytic index, after UV blood irradiation it became more pronounced than in those with the initial elevated level. The enhancement of phagocytic activity is the result of a direct UV-stimulation of cells. This stimulation not mediated by irradiated blood plasma is known to inhibit the phagocytic activity of leucocytes. A possible mechanism of phagocytic activity stimulation is discussed.     

Influence of the iron saturation of bacteria on the phagocytic capacity of neutrophils

The comparative study of the adsorptive capacity of human blood neutrophils with respect to "iron saturated" cells of bacteria belonging to different systematic groups was carried out. A decrease in the phagocytic number by 22-76% of the control level was shown. In experiments with iron-saturated Gram positive bacteria the phagocytic number was noted to be less than the physiological norm.     

Sympathetic hyperreactivity in offspring of essential hypertensive patients

A multistage exercise test was carried out in normotensive subjects with normotensive parents (controls; n = 12), and 32 offspring of essential hypertensive patients that were normotensive (NTO; n = 20) or borderline hypertensive (BHO; n = 12) The groups were comparable as to age, weight and working capacity. Changes in sympathetic nervous activity were determined by measurements of plasma noradrenaline. The initial rise in noradrenaline levels during the exercise test was proportional to the increase in work load until the noradrenaline concentration rose sharply to levels more than 1000 pg/ml above baseline levels. The work load immediately prior to the steep rise in plasma noradrenaline (sympathetic threshold level: STL) is considered to represent the point from which anaerobic energy-yielding processes play an increasingly greater role as the work load increases. The initial increase in plasma noradrenaline until STL was significantly higher in both the NTO (p less than 0.02) and BHO (p less than 0.005) compared to the control group. The absolute noradrenaline level at STL and the increase in noradrenaline from baseline to STL were significantly higher in the BHO group (p less than 0.02, p less than 0.005). No significant differences between the groups were found when comparing noradrenaline levels at rest or at absolute or relative work loads. The systolic blood pressure response during the exercise test was significantly more pronounced in the BHO group (p less than 0.05) compared to the controls and the NTO group.     

The Relationship of Metabolic Syndrome with Stress,Coronary Heart Disease and Pulmonary Function - An Occupational Cohort-Based Study

Background and Aims

Higher levels of stress impact the prevalence of metabolic syndrome (MetS) and coronary heart disease. The association between MetS, impaired pulmonary function and low level of physical activity is still pending assessment in the subjects exposed to stress. The study aimed to examine whether higher levels of stress might be related to MetS and the plaque presence, as well as whether MetS might affect pulmonary function.

Design and Methods

The study embraced 235 police officers (mean age 40.97 years) from the south of Poland. The anthropometrics and biochemical variables were measured; MetS was diagnosed using the International Diabetes Federation criteria. Computed tomography coronary angiography of coronary arteries, exercise ECG, measurements of brachial flow-mediated dilation, and carotid artery intima-media thickness were completed. In order to measure the self-perception of stress, 10-item Perceived Stress Scale (PSS-10) was applied. Pulmonary function and physical activity levels were also addressed. Multivariate logistic regression analyses were applied to determine the relationships between: 1/ incidence of coronary plaque and MetS per se, MetS components and the number of classical cardiovascular risk factors, 2/ perceived stress and MetS, 3/ MetS and pulmonary function parameters.

Results

Coronary artery atherosclerosis was less associated with MetS (OR = 2.62, 95%CI 1.24–5.52; p = 0.011) than with a co-existence of classical cardiovascular risk factors (OR = 5.67, 95% CI 1.07–29.85, p = 0.03; for 3 risk factors and OR = 9.05; 95% CI 1.24–66.23, p = 0.02; for 6 risk factors, respectively). Perceived stress increased MetS prevalence (OR = 1.07, 95% CI 1.03–1.13; p = 0.03), and impacted coronary plaque prevalence (OR = 1.05, 95% CI 1.001–1.10; p = 0.04). Leisure-time physical activity reduced the chances of developing MetS (OR = 0.98 95% CI 0.96–0.99; p = 0.02). MetS subjects had significantly lower values of certain pulmonary function parameters.

Conclusions

Exposure to job-specific stress among police officers increased the prevalence of MetS and impacted coronary plaque presence. MetS subjects had worse pulmonary function parameters. Early-stage, comprehensive therapeutic intervention may reduce overall risk of cardiovascular events and prevent pulmonary function impairment in this specific occupational population.     

Coping with abortion

This study evaluated individual differences in coping style in response to an abortion procedure. The 55 subjects displayed a wide range of responses, although the average level of distress was fairly high. These women were quite similar to other stressed populations in their response to the Impact of Event Scale, providing evidence for a generalized stress response syndrome. When divided into groups based on coping style, "avoiders" were found to experience more distress that "nonavoiders," and "approachers" decreased in distress over time while "nonapproachers" did not. The implications of these findings are discussed in the context of the interaction between coping styles and counseling strategies.     

Reduced glucocorticoid sensitivity of monocyte interleukin-6 release in male employees with high plasma levels of tumor necrosis factor-alpha

Cytokine production by monocytes plays a key role in atherosclerosis. In vitro, preincubation of whole blood with tumor necrosis factor (TNF)-alpha regulates interleukin (IL)-6 release from monocytes stimulated with lipopolysaccharide (LPS). We investigated whether plasma levels of TNF-alpha would also relate to LPS-stimulated monocyte IL-6 production and the inhibitory effect of a glucocorticoid on this process. 224 middle-aged men were assigned to three groups according to tertiles of plasma levels of TNF-alpha. Subjects in the highest tertile (high TNF-alpha, n = 75) were compared to those in the lowest (low TNF-alpha, n = 74) and medium tertile (medium TNF-alpha, n = 75), respectively. In vitro monocyte IL-6 release following lipopolysaccharide (LPS)-stimulation was assessed with and without coincubation with incremental doses of dexamethasone. Monocyte glucocorticoid sensitivity was defined as the dexamethasone concentration inhibiting IL-6 release by 50%. Subjects with high TNF-alpha showed more IL-6 release after LPS-stimulation than those with low TNF-alpha (p =.011). Monocyte glucocorticoid sensitivity was lower in subjects with high levels of TNF-alpha than in subjects with low (p =.014) and with medium (p =.044) levels of TNF-alpha. Results held significance when a set of classic cardiovascular risk factors was controlled for. Our findings suggest that elevated plasma levels of TNF-alpha might enhance LPS-stimulated IL-6 release from circulating monocytes. Such a mechanism might contribute to exaggerated monocyte cytokine release in vivo to any LPS-like danger signal such as related to an infection or cellular stress thereby promoting atherosclerosis.     

Stress-induced hormonal and mood responses in scuba divers: a field study

The majority of injuries in scuba-divers are attributable to inappropriate behavior under stressful diving conditions, predominantly involving panic reactions emerging from elevated levels of anxiety. Divers with an elevated level of anxiety and poor coping are at higher risk of developing panic reactions than those possessing more adequate stress-coping-mechanisms. In the comparison of two extreme groups of seven divers each with opposite stress coping strategies, prolactin was found to be a hormonal marker with a significant increase in the sub-group of the stress-controllers. This hormonal response was observed in a recreational and a stressful dive, and in the latter with a more distinct elevation. Along with the self-reported emotional conditions under immersion, these data suggest that an increased prolactin level reflects a state of elevated physical and mental activation and vigilance. Facing a stressful situation subjects with more emotional concern and the tendency to surrender react by "blunted responses" and show significantly lower elevations of the prolactin levels in contrast to subjects with the very opposite psychological features. The other observed somatic parameters (epinephrine, norepinephrine) showed significant increases during and after dives (with the exception of saliva cortisol), however without any significant group difference.     

The effects of aging and activity on muscle blood flow

Background

Our purpose was to determine if aging had an influence on muscle blood flow independent of habitual physical activity levels.

Methods

Blood flow was measured in the femoral artery by Doppler ultrasound after cuff occlusion of 10 minutes. Active and inactive older subjects (73 ± 7 years) were compared to active and inactive young subjects (26 ± 6 years).

Results

Peak blood flow capacity when normalized to lean muscle mass was related to activity level (p < 0.001), but not to age. Specifically, the young active group had higher peak blood flows than the young inactive (p = 0.031) or older inactive (p = 0.005) groups. Resting blood flow and conductance were not significantly different between groups. Mean arterial pressure was significantly higher in the older compared to young group (p = 0.002). Conductance was related to both activity (p = 0.002) and age (p = 0.003). A prolonged time for blood flow to recover was found in the older compared to the young group (p = 0.038) independent of activity status.

Conclusions

The prolonged recovery time in the older subjects may suggest a reduced vascular reactivity associated with increased cardiovascular disease risk. Peak blood flow capacity is maintained in older subjects by physical activity. In summary, maximal flow capacity and prolonged recovery of blood flow are influenced by different mechanisms in young and older active and inactive subjects.

     

The effect of daily hassles of humoral immunity: An interaction moderated by locus of control

Research has shown that stress is associated with depressed cellular immune functioning. Controversy exists as to whether humoral immunity shows a similar depression under stress. Several psychological variables have been found to moderate responses to stress. In particular, an internal locus of control has been correlated with better health. The present study examined the level of salivary immunoglobulin A (IgA) and health locus of control in subjects with high and low stress levels. The Hassles scale was administered to identify two subject groups differing significantly in reported stress levels. Results showed no significant differences between the two groups on salivary IgA. There was a significant negative correlation between IgA and internal locus of control. The direction of this correlation is in contrast with previous findings on internality. The evidence suggests that high internal individuals may be especially vulnerable to high levels of stress, particularly stress that they cannot control. Also, there was a significant difference in IgA levels between females depending on whether they were in the first or the second half of their menstrual cycle. Those in the premenstrual phase had lower IgA levels.     

The effect of daily Hassles of humoral immunity: an interaction moderated by locus of control

Research has shown that stress is associated with depressed cellular immune functioning. Controversy exists as to whether humoral immunity shows a similar depression under stress. Several psychological variables have been found to moderate responses to stress. In particular, an internal locus of control has been correlated with better health. The present study examined the level of salivary immunoglobulin A (IgA) and health locus of control in subjects with high and low stress levels. The Hassles scale was administered to identify two subject groups differing significantly in reported stress levels. Results showed no significant differences between the two groups on salivary IgA. There was a significant negative correlation between IgA and internal locus of control. The direction of this correlation is in contrast with previous findings on internality. The evidence suggests that high internal individuals may be especially vulnerable to high levels of stress, particularly stress that they cannot control. Also, there was a significant difference in IgA levels between females depending on whether they were in the first or the second half of their menstrual cycle. Those in the premenstrual phase had lower IgA levels.     

Circadian variation of the phagocytic activity of polymorphonuclear leukocytes and of various other parameters in 13 healthy male adults.

Twenty-four different laboratory parameters including the phagocytic activity (phagocytic index) of polymorphonuclear leukocytes (PMNs) and various hematologic variables were investigated in 13 young healthy men during Spring 1988 in Munich, Germany. Venous blood of these volunteers was obtained under standardized conditions at 4-h intervals over a 24-h span. All parameters were analyzed by the single cosinor method and by a Kruskal-Wallis analysis of variance (ANOVA). Statistically significant circadian rhythms were found for the number of circulating lymphocytes and leukocytes (WBCs), potassium, systolic blood pressure, phagocytic index, Quick test, heart rate, and rectal body temperature (p less than 0.05; single cosinor). For all of these parameters except WBCs, rectal body temperature, and Quick test, a temporal variation was confirmed by the ANOVA (p less than 0.05; phagocytic index: p = 0.05). The circadian acrophases of WBC, number of circulating lymphocytes, and phagocytic index were all found at about 01:00 h. This temporal coincidence of the acrophases of the phagocytic index and the number of circulating lymphocytes may reflect the modulation of phagocytosis by T lymphocytes that release cytokines known to stimulate the phagocytic activity of PMNs.     

Immune response in experimental animals immunized with Burkholderia pseudomallei surface antigens

The influence of the chromatographic fractions of B. pseudomallei surface antigenic complex (C, C1, D, H) on immune response in white rats and white mice was under study. These antigenic complexes were noted to produce perceptible stimulating effect on the immune system of white rats, in contrast to that of white mice. The immunization of the mice the above-mentioned fractions suppressed the phagocytic activity of peritoneal macrophages (PM) and slightly enhanced cell-mediated immunity. In experiments on white rats, fraction C induced the growth of specific antibody titers and stimulated the phagocytic activity of PM, as well as the indices of delayed hypersensitivity (DH). Fraction D showed a lower level of the induction of the phagocytic activity of PM and was inactive in the manifestation of cell-mediated immunity, but induced a high level of humoral immunity. Antigenic complexes C1 and H increased the phagocytic activity of PM and DH characteristics with a low level of antibody production. The studied fractions of the causative agent of melioidosis decreased the content of bactericidal cationic proteins (BCP) in rat blood neutrophils, and in mice a decreased content of BCP in phagocytes was registered. The fractions increased the activity of myeloperoxidase in blood neutrophils in mice and rats. As revealed with the use of immunoelectrophoresis, SDS PAAG electrophoresis and immunoblotting, the surface antigenic complex contained proteins of 18, 22, 39 kD and glycoproteins 42, 55, 90 kD. The latter glycoprotein was found in all the fractions under study, having protective properties.     

Influence of an Interpersonal Laboratory Stressor on Youths’ Choice to Be Physically Active

Objective: To determine whether interpersonal stress reduces youths’ motivation to exercise in a laboratory setting. Research Methods and Procedures: Physical activity and sedentary behavior were measured in boys and girls across a control day, after reading children's magazines, and on a stress day, after giving a videotaped speech. For one analysis, children were divided into low (n = 12) and high (n = 13) heart‐rate reactivity groups based on changes in heart rate to stress. In a second analysis, children were divided into low and high perceived level of stress based on changes in perceived stress. To determine differences in choice of exercise or sedentary behavior across the control and stress conditions, subjects chose either to exercise for progressively longer periods to earn a monetary reinforcer or to engage in a high‐rated sedentary behavior. Results: The choice to exercise was influenced by stress reactivity differently in the stress and control conditions. Low heart‐rate reactive children participated in similar (p > 0.50) amounts of exercise on the stress and control days, but high heart‐rate reactive children participated in less (p < 0.01) exercise (22.0 ± 2.5 vs. 26.3 ± 2.2 minutes) on the stress than control days. When grouped by change in perceived stress, there were no group differences, but subjects exercised longer (p < 0.01) on the control day than the stress day. Discussion: Interpersonal stress decreased exercise in children susceptible to interpersonal stress. Stress‐induced alterations in health behaviors may lead to weight gain in children.     

Methionine challenge paradoxically induces a greater activation of the antioxidant defence in subjects with hyper- vs. normohomocysteinemia

To determine whether hyperhomocysteinemia induced post-methionine loading (PML) is associated with different response in the aminothiol redox state and oxidative stress vs. normohomocysteinemia, we assessed PML plasma thiols, vitamins, free malondialdehyde (MDA), and blood reduced glutathione (GSH) in 120 consecutive subjects (50 [35-56] years, 83 males), divided into two groups according to PML plasma total Hcy < 35 microM (Group 1, n = 65) or > or = 35 microM (Group 2, n = 55).In the group as a whole, plasma reduced cysteine and cysteinylglycine, blood reduced GSH (all p for time = 0.0001) and plasma total GSH (p for time = 0.001) increased from baseline to PML. MDA values were unchanged. Group 1 and 2 differed in blood reduced GSH (p for group = 0.004, higher in Group 2), and MDA levels (p for group = 0.024, lower in Group 2).The oxidative stress induced by methionine challenge seems to be opposed by scavenger molecules activation, namely GSH, and lipid peroxidation does not increase. This mechanism paradoxically appears to be more efficient in hyperhomocysteinemic subjects.     

Cardiovascular and renal effects of calcitonin gene-related peptide in hypertensive dogs

The systemic cardiovascular and renal effects of synthetic beta-human calcitonin gene-related peptide (beta-hCGRP) were examined in conscious normotensive and one-kidney one-clip (1K-1C) hypertensive dogs. beta-hCGRP was infused intravenously at 10 and 50 ng/kg/min for 75-min periods each. Mean arterial pressure did not change significantly (p greater than 0.05) in either group during low dose infusion of beta-hCGRP, but infusion of beta-hCGRP at 50 ng/kg/min produced a fall in mean arterial pressure from 140 +/- 4 to 116 +/- 6 mmHg (p less than 0.05) in the hypertensive dogs (n = 4) and from 100 +/- 4 to 78 +/- 3 mmHg (p less than 0.05) in the normotensive dogs (n = 4). Heart rates increased significantly during infusion of beta-hCGRP in both groups. Also, renal sodium and potassium excretion decreased (p less than 0.05) in the two groups at both the low and high doses of beta-hCGRP. Creatinine clearance was unchanged in normal dogs and decreased (p less than 0.05) in 1K-1C hypertensive dogs at the high rate of beta-hCGRP infusion. The clearance of p-aminohippurate increased approximately 20% (p less than 0.05) in both groups with the low dose infusion of beta-hCGRP but further increases were elicited only in the normotensive dogs in response to the elevation in the beta-hCGRP infusion rate. Plasma renin and aldosterone levels increased (p less than 0.05) above control levels during the maximum hypotensive response to beta-hCGRP infusion in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Maintenance of Positive Diversity-Stability Relations along a Gradient of Environmental Stress

Background

Environmental stress is widely considered to be an important factor in regulating whether changes in diversity will affect the functioning and stability of ecological communities.

Methodology/Principal Findings

We investigated the effects of a major environmental stressor (a decrease in water volume) on diversity-abundance and diversity-stability relations in laboratory microcosms composed of temperate multi-trophic rock pool communities to identify differences in community and functional group responses to increasing functional group richness along a gradient of environmental stress (low, medium, and high water volume). When a greater number of functional groups were present, communities were less temporally variable and achieved higher abundances. The stabilizing effect of increased functional group richness was observed regardless of the level of environmental stress the community was subjected too. Despite the strong consistent stabilizing effect of increased functional group richness on abundance, the way that individual functional groups were affected by functional group richness differed along the stress gradient. Under low stress, communities with more functional groups present were more productive and showed evidence of strong facilitative interactions. As stress increased, the positive effect of functional group richness on community abundance was no longer observed and compensatory responses became more common. Responses of individual functional groups to functional group richness became increasing heterogeneous are stress increased, prompting shifts from linear diversity-variability/abundance relations under low stress to a mix of linear and non-linear responses under medium and high stress. The strength of relations between functional group richness and both the abundances and temporal variability of functional groups also increased as stress increased.

Conclusions/Significance

While stress did not affect the relation between functional group richness and stability per se, the way in which functional groups responded to changes in functional group richness differed as stress increased. These differences, which include increases in the heterogeneity of responses of individual functional groups, increases in compensatory dynamics, and increases in the strength of richness-abundance and richness-variability relations, may be critical to maintaining stability under increasingly stressful environmental conditions.     

Cardiac content of brain natriuretic peptide in DOCA salt-hypertensive rats

The cardiac content of immunoreactive rat brain natriuretic peptide (ir-rBNP) in deoxycorticosterone acetate (DOCA)-salt hypertensive rats was measured by radioimmunoassay (RIA). The atrial content of ir-rBNP was significantly lower in the DOCA-salt group than in the control group (p less than 0.01). However, the ventricular content of ir-rBNP was markedly increased in the DOCA-salt group as compared to the other groups. Ir-rBNP level in the atria was negatively correlated with other groups. Ir-rBNP level in the atria was negatively correlated with blood pressure (r = -0.49, p less than 0.01), while that in the ventricle was positively correlated with blood pressure (r = 0.79, p less than 0.001). A significant correlation was observed between tissue levels of ir-rBNP and ir-rat atrial natriuretic peptide (rANP) both in atrium and ventricle (atrium, r = 0.63, p less than 0.001; ventricle, r = 0.95, p less than 0.001). These results raise the possibility that rBNP as well as rANP functions as a cardiac hormone, the production of which probably changes in response to increased of body fluid and blood pressure.     

Cardiovascular reactivity to emotional texts in subjects with low and high level of psychoticism

The article presents the results of comparative study of groups of subjects with low and high level of psychoticism. Heart rate, heart rate responses to inspiratory and expiratory Valsalva maneuvers, and blood pressure were measured before and after presentation of the texts with validated negative content in groups of subjects with low and high psychoticism scores. It was hypothesized that subjects with high level of psychoticism would be less engaged in the processing of negative contents of the texts and their physiological reactivity (physiological resources submitted for support of cognitive processing) would be less pronounced compared to subjects with low level of psychoticism. Significant main effect of psychoticism was obtained for changes in heart rate to expiratory Valsalva maneuver after presentations of the texts. Significant interaction effects of gender and psychoticism were obtained for systolic blood pressure. Other cardiovascular variables were not sensitive to the level of psychoticism. These effects of psychoticism were independent of other individual traits, such as neuroticism, extraversion, lie (social desirability), anger, trait anxiety and depression.