Life events, frontal electroencephalogram laterality, and functional immune status after acute psychological stressors in adolescents

Observed parent-child relationship quality predicts antibody response to vaccination in children

BACKGROUND

Quality of the parent-child relationship is a robust predictor of behavioral and emotional health for children and adolescents; the application to physical health is less clear.

METHODS

We investigated the links between observed parent-child relationship quality in an interaction task and antibody response to meningococcal conjugate vaccine in a longitudinal study of 164 ambulatory 10-11 year-old children; additional analyses examine associations with cortisol reactivity, BMI, and somatic illness.

RESULTS

Observed Negative/Conflict behavior in the interaction task predicted a less robust antibody response to meningococcal serotype C vaccine in the child over a 6 month-period, after controlling for socio-economic and other covariates. Observer rated interaction conflict also predicted increased cortisol reactivity following the interaction task and higher BMI, but these factors did not account for the link between relationship quality and antibody response.

CONCLUSIONS

The results begin to document the degree to which a major source of child stress exposure, parent-child relationship conflict, is associated with altered immune system development in children, and may constitute an important public health consideration.

Relationship between neural activity and immunity in patients with undifferentiated somatoform disorder

It has been suggested that somatoform disorders are related to both the brain and the immune system, and that immune functions may be influenced by cerebral asymmetry. However, few studies have examined the relationship between brain activity and immune function in somatoform disorders. Thirty-two patients with non-medicated undifferentiated somatoform disorder were enrolled in this study. Blastogenic responses to phytohemagglutinin (PHA) were used to measure immunity. Regional cerebral perfusion was measured by 99m-Tc-ethyl cysteinate dimer single photon emission computed tomography (SPECT). Significant hypoperfusion was found at the left inferior parietal lobule and the left supramarginal gyrus in the more immune-suppressed (MIS) subgroup compared with the less immune-suppressed (LIS) subgroup. However, no regions of significant hyperperfusion were found in the MIS subgroup compared with the LIS subgroup. Decreased cerebral blood flow in the left inferior parietal lobule and the left supramarginal gyrus in the patient group was also significantly associated with reduced blastogenic responses to PHA regardless of sex and age. These results suggest that the left inferior parietal lobule and the left supramarginal gyrus might play an immunomodulating role in patients with undifferentiated somatoform disorder. In addition, these results suggest the role of cerebral asymmetry in altered immunity in the patients.

Effect of phytoncide from trees on human natural killer cell function

We previously reported that the forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after trips to forests both in male and female subjects. To explore the factors in the forest environment that activated human NK cells, in the present study we investigate the effect of essential oils from trees on human immune function in twelve healthy male subjects, age 37-60 years, who stayed at an urban hotel for 3 nights from 7.00 p.m. to 8.00 a.m. Aromatic volatile substances (phytoncides) were produced by vaporizing Chamaecyparis obtusa (hinoki cypress) stem oil with a humidifier in the hotel room during the night stay. Blood samples were taken on the last day and urine samples were analysed every day during the stay. NK activity, the percentages of NK and T cells, and granulysin, perforin, granzyme A/B-expressing lymphocytes in blood, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the stay on a normal working day. The concentrations of phytoncides in the hotel room air were measured. Phytoncide exposure significantly increased NK activity and the percentages of NK, perforin, granulysin, and granzyme A/B-expressing cells, and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene, were detected in the hotel room air. These findings indicate that phytoncide exposure and decreased stress hormone levels may partially contribute to increased NK activity.

The impact of environmental risk factors on HIV-associated cognitive decline in children

Both the human immunodeficiency virus (HIV) and environmental stress have been independently associated with decreased cognitive functioning in children. Given that they are also known to have a strong relationship with each other, the present study sought to test the hypothesis that children in conditions of high environmental risk would be at greater risk for the cognitive complications related to immunosuppression. A retrospective review was conducted to examine the records of 141 children treated at a large pediatric AIDS clinic from 1993 to 2000. CD4+ lymphocyte levels were recorded from laboratory results and IQ scores were recorded from routine psychological evaluations. Key indicators of environmental risk were collected and combined into one measure of overall environmental risk. Pearson product moment correlations were conducted to examine the relationship between environmental risk, age-adjusted CD4 and IQ. Results indicated a significant correlation between CD4 and IQ, with higher levels of immunocompetence predicting higher IQ scores. When subjects were dichotomized based on their environmental risk score, there was no relationship between CD4 count and IQ in the low environmental risk group. In contrast, CD4 was positively associated with IQ in the high environmental risk group. It is proposed that this may be due to gp120 levels in immunocompromised children being particularly toxic to the hippocampus and cortex under conditions of high stress but not so under conditions of low stress.

Healthy lifestyles are associated with higher levels of perforin, granulysin and granzymes A/B-expressing cells in peripheral blood lymphocytes

OBJECTIVE

It is well documented that natural killer (NK) cells provide host defense against tumors and viruses. We previously showed that lifestyle affects human NK and LAK activities. In order to explore the underlying mechanism, we investigated the effect of lifestyle on intracellular perforin, granulysin, and granzymes A/B in peripheral blood lymphocytes (PBL).

METHODS

114 healthy male subjects, aged 20-59 years, from a large company in Osaka, Japan were selected with informed consent. The subjects were divided into groups reporting good, moderate, and poor lifestyles according to their responses on a questionnaire regarding eight health practices (cigarette smoking, alcohol consumption, sleeping hours, working hours, physical exercise, eating breakfast, balanced nutrition, and mental stress). Peripheral blood was taken, and numbers of NK, T, perforin, granulysin, and granzymes A/B-expressing cells in PBL were measured by flow cytometry.

RESULTS

Subjects with good or moderate lifestyle showed significantly higher numbers of NK, and perforin, granulysin, and granzymes A/B-expressing cells and a significantly lower number of T cells in PBL than subjects with poor lifestyle. Among the eight health practices, cigarette smoking, physical exercise, eating breakfast, and balanced nutrition significantly affect the numbers of NK, T cells, perforin, granulysin, and/or granzymes A/B-expressing cells, and alcohol consumption significantly affects the number of granzyme A-expressing cells. On the other hand, mental stress, sleeping, and working hours had no effect on those parameters.

CONCLUSIONS

Taken together, these findings indicate that poor lifestyle significantly decreases the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells in PBL.

Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.

Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of specific immunity. Brief naturalistic stressors (such as exams) tended to suppress cellular immunity while preserving humoral immunity. Chronic stressors were associated with suppression of both cellular and humoral measures. Effects of event sequences varied according to the kind of event (trauma vs. loss). Subjective reports of stress generally did not associate with immune change. In some cases, physical vulnerability as a function of age or disease also increased vulnerability to immune change during stressors.

Psychoneuroimmunology and psychosomatic medicine: back to the future

OBJECTIVE

Although psychological modulation of immune function is now a well-established phenomenon, much of the relevant literature has been published within the last decade. This article speculates on future directions for psychoneuroimmunology research, after reviewing the history of the field.

METHODS

This review focuses on human psychoneuroimmunology studies published since 1939, particularly those that have appeared in Psychosomatic Medicine. Studies were clustered according to key themes, including stressor duration and characteristics (laboratory stressors, time-limited naturalistic stressors, or chronic stress), as well as the influences of psychopathology, personality, and interpersonal relationships; the responsiveness of the immune system to behavioral interventions is also addressed. Additionally, we describe trends in populations studied and the changing nature of immunological assessments. The final section focuses on health outcomes and future directions for the field.

RESULTS

There are now sufficient data to conclude that immune modulation by psychosocial stressors or interventions can lead to actual health changes, with the strongest direct evidence to date in infectious disease and wound healing. Furthermore, recent medical literature has highlighted a spectrum of diseases whose onset and course may be influenced by proinflammatory cytokines, from cardiovascular disease to frailty and functional decline; proinflammatory cytokine production can be directly stimulated by negative emotions and stressful experiences and indirectly stimulated by chronic or recurring infections. Accordingly, distress-related immune dysregulation may be one core mechanism behind a diverse set of health risks associated with negative emotions.

CONCLUSIONS

We suggest that psychoneuroimmunology may have broad implications for the basic biological sciences and medicine.

Stress management in medical education: a review of the literature

PURPOSE

To review systematically clinical studies providing empirical data on stress-management programs in medical training.

METHOD

The authors searched Medline and PSYCHINFO from 1966 to 1999. Studies were included if they evaluated stress-management programs for medical trainees (medical students, interns, or residents); reported empirical data; and had been conducted at allopathic medical schools.

RESULTS

Although the search yielded over 600 articles discussing the importance of addressing the stress of medical education, only 24 studies reported intervention programs, and only six of those used rigorous scientific method. Results revealed that medical trainees participating in stress-management programs demonstrated (1) improved immunologic functioning, (2) decreases in depression and anxiety, (3) increased spirituality and empathy, (4) enhanced knowledge of alternative therapies for future referrals, (5) improved knowledge of the effects of stress, (6) greater use of positive coping skills, and (7) the ability to resolve role conflicts. Despite these promising results, the studies had many limitations.

CONCLUSION

The following considerations should be incorporated into future research: (1) rigorous study design, including randomization and control (comparison) groups, (2) measurement of moderator variables to determine which intervention works best for whom, (3) specificity of outcome measures, and (4) follow-up assessment, including effectiveness of future patient care.