Slowing of wound healing by psychological stress

There is evidence that psychological stress adversely affects the immune system. We have investigated the effects of such stress, caused by caring for a relative with Alzheimer's disease, on wound healing. We studied 13 women caring for demented relatives (mean age 62.3 [SE 2.3] years) and 13 controls matched for age (60.4 [2.8] years) and family income. All subjects underwent a 3.5 mm punch biopsy wound. Healing was assessed by photography of the wound and the response to hydrogen peroxide (healing was defined as no foaming). Wound healing took significantly longer in caregivers than in controls (48.7 [2.9] vs 39.3 [3.0] days, p < 0.05). Peripheral-blood leucocytes from caregivers produced significantly less interleukin-1 beta mRNA in response to lipopolysaccharide stimulation than did controls' cells. Stress-related defects in wound repair could have important clinical implications, for instance for recovery from surgery.

Spousal caregivers of dementia victims: longitudinal changes in immunity and health

Providing long-term care for a demented relative profoundly affects caregivers' lives. We assessed changes in depression, immune function, and health in 69 spousal caregivers who had already been caregiving for an average of five years and 69 sociodemographically matched control subjects. Between the initial sample ("intake") and the follow-up data collected an average of 13 months later, caregivers showed decrements relative to controls on three measures of cellular immunity. Caregivers also reported significantly more days of infectious illness, primarily upper respiratory tract infections. Caregivers had a much greater incidence of depressive disorders than controls, with 25% of caregivers meeting syndromal criteria at intake and 32% at follow-up, compared with no cases among controls at intake and 6% at follow-up. Caregivers who reported lower levels of social support at intake and who were most distressed by dementia-related behaviors showed the greatest and most uniformly negative changes in immune function at follow-up.

Psychosocial modifiers of immunocompetence in medical students

This study addressed the effects of a naturally occurring stressor on components of the immune response. Blood was drawn twice from 75 first-year medical students, with a baseline sample taken one month before their final examinations and a stress sample drawn on the first day of final examinations. Median splits on scores from the Holmes--Rahe Social Readjustment Rating Scale and the UCLA Loneliness Scale produced a 2 X 2 X 2 repeated measures ANOVA when combined with the trials variable. Natural killer (NK) cell activity declined significantly from the first to the second sample. High scorers on stressful life events and loneliness had significantly lower levels of NK activity. Total plasma IgA increased significantly from the first to second sample, while plasma IgG and IgM, C-reactive protein, and salivary IgA did not change significantly.

Chronic stress alters the immune response to influenza virus vaccine in older adults

To determine whether a chronic stressor (caregiving for a spouse with a progressive dementia) is associated with an impaired immune response to influenza virus vaccination, we compared 32 caregivers' vaccine responses with those of 32 sex-, age-, and socioeconomically matched control subjects. Caregivers showed a poorer antibody response following vaccination relative to control subjects as assessed by two independent methods, ELISA and hemagglutination inhibition. Caregivers also had lower levels of in vitro virus-specific-induced interleukin 2 levels and interleukin 1beta; interleukin 6 did not differ between groups. These data demonstrate that down-regulation of the immune response to influenza virus vaccination is associated with a chronic stressor in the elderly. These results could have implications for vulnerability to infection among older adults.

Marital quality, marital disruption, and immune function

Marital disruption is associated with significant increases in a variety of psychologic and physical disorders. In order to examine psychologic and physiologic mediators, self-report data and blood samples were obtained from 38 married women and 38 separated/divorced women. Among married subjects, poorer marital quality was associated with greater depression and a poorer response on three qualitative measures of immune function. Women who had been separated 1 year or less had significantly poorer qualitative and quantitative immune function than their sociodemographically matched married counterparts. Among the separated/divorced cohort, shorter separation periods and greater attachment to the (ex)husband were associated with poorer immune function and greater depression. These data are consistent with epidemiologic evidence linking marital disruption with increased morbidity and mortality.

Chronic stress and immunity in family caregivers of Alzheimer's disease victims

Although acute stress has been associated with transient immunosuppression, little is known about the immunologic consequences of chronic stress in humans. In order to investigate possible health-related consequences of a long-term stressor, we obtained blood samples for immunologic and nutritional analyses and psychologic data from 34 family caregivers of Alzheimer's disease (AD) victims and 34 sociodemographically matched comparison subjects. Family caregivers for AD victims were more distressed than comparison subjects without similar responsibilities. Greater impairment in the AD victim was associated with greater distress and loneliness in caregivers. Caregivers had significantly lower percentages of total T lymphocytes and helper T lymphocytes than did comparison subjects, as well as significantly lower helper-suppressor cell ratios; caregivers also had significantly higher antibody titers to Epstein-Barr virus than did comparison subjects, presumably reflecting poorer cellular immune system control of the latent virus in caregivers. The percentages of natural killer cells and suppressor T lymphocytes did not differ significantly. These data suggest that chronically stressed AD family caregivers do not show immunologic or psychologic adaptation to the level of their well-matched age peers.

Psychological influences on surgical recovery. Perspectives from psychoneuroimmunology

Greater fear or distress prior to surgery is associated with a slower and more complicated postoperative recovery. Although anxiety presumably interferes with recuperation through both behavioral and physiological mechanisms, the pathways have been unclear. Recent work in psychoneuroimmunology (PNI) has demonstrated that stress delays wound healing. In addition, a second line of research has illustrated the adverse effects of pain on endocrine and immune function. A biobehavioral model is described that is based on these and other data; it suggests a number of routes through which psychological and behavioral responses can influence surgery and post-surgical outcomes. Clinical and research implications are highlighted.

A biobehavioral model of cancer stress and disease course

Approximately 1 million Americans are diagnosed with cancer each year and must cope with the disease and treatments. Many studies have documented the deteriorations in quality of life that occur. These data suggest that the adjustment process is burdensome and lengthy. There is ample evidence showing that adults experiencing other long-term stressors experience not only high rates of adjustment difficulties (e.g., syndromal depression) but important biologic effects, such as persistent downregulation of elements of the immune system, and adverse health outcomes, such as higher rates of respiratory tract infections. Thus, deteriorations in quality of life with cancer are underscored if they have implications for biological processes, such as the immune system, relating to disease progression and spread. Considering these and other data, a biobehavioral model of adjustment to the stresses of cancer is offered, and mechanisms by which psychological and behavioral responses may influence biological processes and, perhaps, health outcomes are proposed. Finally, strategies for testing the model via experiments testing psychological interventions are offered.

Stress, loneliness, and changes in herpesvirus latency

This study used a prospective design to examine the influence of examination stress and loneliness on herpesvirus latency as measured by changes in antibody levels to three herpesviruses, Epstein-Barr virus (EBV), Herpes simplex type I (HSV-1), and cytomegalovirus (CMV). Three blood samples were obtained from 49 first-year medical students, with the first sample drawn 1 month before final examinations, the second on the first day of final examinations, and the third during the first week after their return from summer vacation. A median split on the UCLA Loneliness Scale divided subjects into high- and low-scoring loneliness groups. There were significant changes in the antibody titers to all three herpesviruses across the sample points, with the lowest levels found in the third (low stress) sample. High-loneliness subjects had significantly higher EBV antibody titers than low-loneliness subjects. These data suggest that stress-related immunosuppression can significantly modulate herpesvirus latency.

Stress and immune responses after surgical treatment for regional breast cancer

BACKGROUND

Adults who undergo chronic stress, such as the diagnosis and surgical treatment of breast cancer, often experience adjustment difficulties and important biologic effects. This stress can affect the immune system, possibly reducing the ability of individuals with cancer to resist disease progression and metastatic spread. We examined whether stress influences cellular immune responses in patients following breast cancer diagnosis and surgery.

METHODS

We studied 116 patients recently treated surgically for invasive breast cancer. Before beginning their adjuvant therapy, all subjects completed a validated questionnaire assessing the stress of being cancer patients. A 60-mL blood sample taken from each patient was subjected to a panel of natural killer (NK) cell and T-lymphocyte assays. We then developed multiple regression models to test the contribution of psychologic stress in predicting immune function. All regression equations controlled for variables that might exert short- or long-term effects on these responses, and we also ruled out other potentially confounding variables.

RESULTS

We found, reproducibly between and within assays, the following: 1) Stress level significantly predicted lower NK cell lysis, 2) stress level significantly predicted diminished response of NK cells to recombinant interferon gamma, and 3) stress level significantly predicted decreased proliferative response of peripheral blood lymphocytes to plant lectins and to a monoclonal antibody directed against the T-cell receptor.

CONCLUSIONS

The data show that the physiologic effects of stress inhibit cellular immune responses that are relevant to cancer prognosis, including NK cell toxicity and T-cell responses. Additional, longitudinal studies are needed to determine the duration of these effects, their health consequences, and their biologic and/or behavioral mechanisms.

Metabolic flux ratio analysis of genetic and environmental modulations of Escherichia coli central carbon metabolism

The response of Escherichia coli central carbon metabolism to genetic and environmental manipulation has been studied by use of a recently developed methodology for metabolic flux ratio (METAFoR) analysis; this methodology can also directly reveal active metabolic pathways. Generation of fluxome data arrays by use of the METAFoR approach is based on two-dimensional (13)C-(1)H correlation nuclear magnetic resonance spectroscopy with fractionally labeled biomass and, in contrast to metabolic flux analysis, does not require measurements of extracellular substrate and metabolite concentrations. METAFoR analyses of E. coli strains that moderately overexpress phosphofructokinase, pyruvate kinase, pyruvate decarboxylase, or alcohol dehydrogenase revealed that only a few flux ratios change in concert with the overexpression of these enzymes. Disruption of both pyruvate kinase isoenzymes resulted in altered flux ratios for reactions connecting the phosphoenolpyruvate (PEP) and pyruvate pools but did not significantly alter central metabolism. These data indicate remarkable robustness and rigidity in central carbon metabolism in the presence of genetic variation. More significant physiological changes and flux ratio differences were seen in response to altered environmental conditions. For example, in ammonia-limited chemostat cultures, compared to glucose-limited chemostat cultures, a reduced fraction of PEP molecules was derived through at least one transketolase reaction, and there was a higher relative contribution of anaplerotic PEP carboxylation than of the tricarboxylic acid (TCA) cycle for oxaloacetate synthesis. These two parameters also showed significant variation between aerobic and anaerobic batch cultures. Finally, two reactions catalyzed by PEP carboxykinase and malic enzyme were identified by METAFoR analysis; these had previously been considered absent in E. coli cells grown in glucose-containing media. Backward flux from the TCA cycle to glycolysis, as indicated by significant activity of PEP carboxykinase, was found only in glucose-limited chemostat culture, demonstrating that control of this futile cycle activity is relaxed under severe glucose limitation.

Modulation of cellular immunity in medical students

This study assessed the psychosocial modulation of cellular immunity in 34 medical-student volunteers. The first blood sample was obtained 1 month before examinations, and the second on the day of examinations. There were significant declines in the percentage of helper/inducer T-lymphocytes, in the helper/inducer-suppressor/cytotoxic-cell ratio, and in natural killer-cell activity in the blood samples obtained on the day of examinations. Half of the subjects were randomly assigned to a relaxation group which met between sample points; the frequency of relaxation practice was a significant predictor of the percentages of helper/inducer cells in the examination sample. Three biochemical nutritional assays (albumin, transferrin, and total iron-binding protein) were within normal limits on both samples. Data from the Brief Symptom Inventory showed significantly increased global self-rated distress associated with examinations in the no-intervention group, compared to nonsignificant change in the relaxation group. Clinical and theoretical implications are discussed.

Negative behavior during marital conflict is associated with immunological down-regulation

Although increased morbidity and mortality have been reliably associated with social isolation and less satisfying personal relationships, relatively little is known about the underlying biopsychosocial mechanisms. We assessed problem-solving behaviors and changes in immune function in 90 newlywed couples who were admitted to a hospital research unit for 24 hours. Subjects who exhibited more negative or hostile behaviors during a 30-minute discussion of marital problems showed greater decrements over 24 hours relative to low negative subjects on four functional immunological assays (natural killer cell lysis, blastogenic response to two mitogens, and the proliferative response to a monoclonal antibody to the T3 receptor), as well as larger increases in the numbers of total T lymphocytes and helper T lymphocytes. High negative subjects had higher antibody titers to latent Epstein-Barr virus than low negative subjects, consistent with down-regulated immune function. Women were more likely to show negative immunological changes than men. The discussion of marital problems also led to larger increases in blood pressure that remained elevated longer in high negative subjects than low negative subjects. Positive or supportive problem-solving behaviors were not related to either immunological or blood pressure changes. These physiological differences were particularly noteworthy because marital satisfaction was high in both groups, and couples had been selected on the basis of stringent mental and physical health criteria. These data provide additional support for the link between personal relationships and immune function.

Stress-related immune suppression: health implications

This study used a year-long prospective design to assess linkages among distress, immunity, and illness. Serial blood samples were collected from 40 first-year medical students at the first, third, and fifth examination periods, as well as 1 month before each. There were significant decrements in the production of gamma-interferon by concanavalin A-stimulated lymphocytes obtained at the time of examinations. Antibody titers to Epstein-Barr virus (EBV) increased during examination periods, suggesting reactivation of latent EBV and therefore poorer cellular immune control of latent virus. We obtained data that suggest that T-cell killing by memory T lymphocytes of EBV transformed autologous B lymphocytes also declined during examination periods. The activity of a lymphokine, leukocyte migration inhibition factor, normally suppressed during recrudescence of herpes simplex virus type 2 infections, was altered during examination periods and an increase in both plasma and intracellular levels of cyclic AMP associated with examination stress was observed. An increase in the incidence of self-reported symptoms of infectious illness was also associated with examination periods. The data support the linkage between stress-related immunosuppression and health.

Stress-related changes in proinflammatory cytokine production in wounds

BACKGROUND

Several recent studies have shown that stress markedly delays wound healing. This study assessed the relationship between psychological stress and the secretion of proinflammatory cytokines at an actual wound site, providing in vivo data on the development of local immune responses that are central in the early stages of wound repair.

METHODS

To study the dynamics of inflammation, skin blisters were induced on the forearm of 36 women (mean age, 57 years) by suction. After the blister roofs were removed, a plastic template was taped to the arm, and wells were filled with 70% autologous serum in buffer. Specimens were aspirated from blister chamber wells 5 and 24 hours after wounding.

RESULTS

Women with higher perceived stress scores demonstrated significantly lower levels of 2 key cytokines--interleukin 1alpha and interleukin 8--at wound sites. In addition, subjects who had low levels of both cytokines after 24 hours reported more stress and negative affect, and they had higher levels of salivary cortisol than those who had high cytokine levels.

CONCLUSION

Consistent with the evidence that stress delays wound healing, these data suggest a possible mechanism: psychological stress has measurable effects on proinflammatory cytokine production in the local wound environment.

Stress-induced modulation of the immune response to recombinant hepatitis B vaccine

Each of a series of three hepatitis B (Hep B) inoculations was given to 48 second-year medical students on the 3rd day of a 3-day examination series to study the effect of academic stress on the ability to generate an immune response to a primary antigen. Those students who seroconverted after the first injection (25%) were significantly less stressed and anxious than those who did not seroconvert at that time. In addition, students who reported greater social support demonstrated a stronger immune response to the vaccine at the time of the third inoculation, as measured by antibody titers to Hep B surface antigen (HBsAg) and the blastogenic response to a HBsAg peptide (SAg).

Marital discord and immunity in males

While limited data suggest significant gender differences in mental and physical health risks following marital disruption, men have not been studied as intensively as women. In this study, self-report data and blood samples were obtained from 32 separated or divorced men and 32 sociodemographically matched married men. Separated/divorced men were more distressed and lonelier, and reported significantly more recent illness than did married men; the former also had significantly poorer values on two functional indices of immunity (antibody titers to two herpesviruses), while not differing significantly on quantitative indices (percentages of helper and suppressor cells and their ratio). Among married men, poorer marital quality was associated with greater distress and a poorer response on one functional immunological measure, antibody to Epstein-Barr virus (EBV), as well as lower helper/suppressor ratios. Among separated/divorced subjects, those who had separated within the past year and who had initiated the separation were less distressed, reported better health, and had a better performance on one functional immunological assay (EBV antibody titers) than did noninitiators. These data are discussed in the context of research on longer-term adaptation to marital disruption.

Two epithelial tumor cell lines (HNE-1 and HONE-1) latently infected with Epstein-Barr virus that were derived from nasopharyngeal carcinomas

Two epithelial tumor cell lines were established from biopsy specimens of nasopharyngeal carcinomas (NPC). The specimens were taken from poorly differentiated squamous cell carcinomas of the nasopharynx. The tissues were prepared for cell culture and eventually two continuous epithelial cell lines were obtained and designated HONE-1 and HNE-1. Light and electron microscopic examination of these two cell lines demonstrated cells with an epithelial morphology including the presence of desmosomes. The HNE-1 cell line has been passaged more than 100 times and the HONE-1 cell line has been passaged more than 90 times. It was found that early-passage uncloned HNE-1 cells (passage 23) could be superinfected with the B95-8 and NPC-EBV isolates as demonstrated by the induction of Epstein-Barr virus (EBV)-specific early antigen(s) in a small percentage of the cells; HONE-1 cells could also be superinfected with EBV. Southern blot analysis detected EBV DNA in samples from uncloned HNE-1 cells at passages 12, 17, 21, 27, and 35. However, by passage 45, EBV DNA could no longer be detected in HNE-1 cells by Southern blot analysis. The EBV genome was detected in parental HONE-1 cells at subculture 9 and in clone 40 cells up to passage 40 thus far. When HNE-1 cells were examined for the expression of the EBV-encoded nuclear antigen (EBNA) at passage 12, only about 10% of the cells were found to be positive. The percentage of EBNA-positive HNE-1 cells decreased as the cells were passaged. A similar loss of EBNA was observed in uncloned HONE-1 cells, but not in HONE-1 clone 40 cells. In clone 40, which has been passaged 40 times thus far, 85-90% of the cells are still EBNA-positive. The data suggest that EBV genome-positive HNE-1 and HONE-1 cells were lost as the cells were cultivated in vitro and that cloning the cells at an early passage level may be critical in maintaining EBV genome-positive epithelial NPC cells. These EBV genome-positive epithelial NPC cell lines will be useful for studying the association of EBV and NPC.

Marital conflict in older adults: endocrinological and immunological correlates

OBJECTIVE

To assess endocrinological and immunological correlates of marital conflict and marital satisfaction, 31 older couples (mean age 67 years) who had been married an average of 42 years were studied.

METHOD

Couples were admitted to the Clinical Research Center and a catheter was placed in each subject's arm. Blood was drawn on entry for immunological assays; for hormone analyses, five blood samples were drawn during a 30-minute conflict discussion and a 15-minute recovery session. The conflict session was recorded on videotapes that were later coded for problem-solving behaviors using the Marital Interaction Coding System (MICS).

RESULTS

Among wives, escalation of negative behavior during conflict and marital satisfaction showed strong relationships to endocrine changes, accounting for 16% to 21% of the variance in the rates of change of cortisol, adrenocorticotropic hormone (ACTH), and norepinephrine (but not epinephrine). In contrast, husbands' endocrine data did not show significant relationships with negative behavior or marital quality. Both men and women who showed relatively poorer immunological responses across three functional assays (the blastogenic response to two T-cell mitogens and antibody titers to latent Epstein-Barr virus) displayed more negative behavior during conflict; they also characterized their usual marital disagreements as more negative than individuals who showed better immune responses across assays.

CONCLUSION

Abrasive marital interactions may have physiological consequences even among older adults in long-term marriages.

Stress-related impairments in cellular immunity

The percentages of total T-lymphocytes (OKT-3+), helper T-cells (OKT-4+), and suppressor T-cells (OKT-8+) were significantly lower in blood samples obtained from 40 medical students during examinations, compared to baseline values obtained 6 weeks earlier. In addition, the response of T-lymphocytes to stimulation by phytohemagglutinin and concanavilin A was also significantly lower during examinations, compared to baseline. Self-report data documented significantly greater distress associated with examinations. The data have implications for immunosuppressive disorders and stress-related illnesses.

Stress depresses interferon production by leukocytes concomitant with a decrease in natural killer cell activity

This study addressed the effects of a commonplace stressful event on interferon production and natural killer (NK) cell activity and numbers. The quantity of interferons (IFN) produced by concanavalin A stimulated leukocytes obtained from 40 medical students during examinations was significantly lower when compared with IFN levels produced by peripheral blood leukocytes (PBLs) taken 6 weeks earlier (baseline). In addition, three different assays measuring NK cells also showed significant decrements during examinations when compared with baseline samples. These assays included lysis of MOLT-4 target cells, percentage of anti-Leu-7+ (NK) cells, and percentage of large granular lymphocytes. Self-report data documented the significantly greater distress associated with examinations in comparison with baseline samples. The data have implications for immunosuppressive disorders and stress-associated illnesses.

Urinary cortisol levels, cellular immunocompetency, and loneliness in psychiatric inpatients

This study examined the associations among loneliness, stressful life events, urinary cortisol levels, and immunocompetency. Blood and urine were obtained from 33 psychiatric inpatients on the day after admission, at which time the patients completed the UCLA Loneliness Scale, the Psychiatric Epidemiology Research Interview Life Events Scale (PERI), and the MMPI. Patients who scored above the median on loneliness had significantly higher urinary cortisol levels. The high loneliness group also had significantly lower levels of natural killer cell activity, as well as a poorer T-lymphocyte response to phytohemagglutinin. The high loneliness subjects described themselves as more distressed than the low loneliness group on the MMPI. There were no consistent significant effects on either the immunologic measures or the MMPI associated with the PERI.