Social and cultural dimensions of hypertension in Brazil: a review

Elevated arterial blood pressure varies substantially in relation to social and cultural variables. Early work on acculturation, socioeconomic status, and blood pressure documented this variation, which could not be explained entirely by conventional factors such as diet, physical activity, or access to medical care. These findings stimulated the development of a model of stress and disease. The stress model emphasizes social and psychological factors that are perceived by individuals to be stressful, as well as factors that help individuals to respond to those stressors. Conventional stress models are, however, problematic because the primary emphasis is on individual perception, with little consideration of the social and cultural context in which stress occurs. This paper describes a complementary model of social and cultural influences on disease risk, placing greater emphasis on how individuals are able to approximate, in their own behaviors, shared cultural models of life, referred to as "cultural consonance". Findings from research in Brazil indicate that the higher an individual's cultural consonance, the lower his or her blood pressure. These results indicate the importance of linking different levels of analysis - the cultural, the individual, and the biological - to understand disease risk.

[The use of enterosorbents for preventing and stopping chronic toxic stress in submariners]

The efficiency of prophylactic intestinal sorbents use (algisorb and activated carbon) to prevent chronic toxic stress was investigated in 20 healthy volunteers (atomic submarine personnel) basing on evaluation of central nervous system functional state, hemodynamics, hepatic detoxicative ability and dynamics of trace elements in urine. It was revealed that intestinal sorbents administration in daily dose of 5 g during 20 days promotes gastrointestinal elimination of toxic compounds (cadmium, bismuth, chrome, molybdenum, lithium). It is accompanied with decrease in organism intoxication evidences: reduction in central nervous system excessive excitation, decrease in functional tension of cardiovascular system, recovery of hepatic detoxicative ability. Algisorb has an advantage over activated carbon that allows to recommend this drug in prophylaxis and arresting of chronic toxic stress in submariners both during interfield period and autonomic sailing.

Psychophysiological stress responses in amputees with and without phantom limb pain

The present experiment tested the hypothesis that phantom limb pain amputees show a different pattern of psychophysiological reactivity to stress compared with painfree amputees. Six phantom limb pain (PLP) and five painfree upper-extremity amputees were administered two groups of tasks: stressful and relaxing. The measured dependent variables were skin temperature recorded at both stump and intact site, heart rate, blood pressure, subjective pain and stress ratings. Phantom limb pain patients were characterized by higher stump temperature compared with phantom limb painfree patients. This effect was observed during the whole recording. Consistently with the between-subjects effect, when PLP patients exhibited higher skin temperature (during relaxation, compared with during stressful tasks), they perceived more pain. The experiment showed higher cardiovascular reactivity in PLP patients, specifically to the stressful free-speech task, which focused on recollection of the amputation event. As compared with the painfree patients, during the personal stressor, PLP patients' heart rate and systolic blood pressure increased, indicating a greater sympathetic response. Results indicate that peripheral factors, such as stump temperature reliably differentiate PLP from painfree patients. Moreover, the clear cardiovascular hyperreactivity observed in PLP patients during their report of amputation suggests that PLP is associated with a long-term emotional memory for the painful experience of that event. These results are consistent with most reports in the literature relating phantom pain development to the experience of preamputation pain.

Music modulates behaviour of premature infants following heel lance

The physiological and behavioural effects of music during recovery from heel lance were examined in 14 preterm infants at 29 to 36 weeks post-conceptual age (PCA). Infants were tested on 2 occasions: during a music condition and during a no-music control condition. Each condition was videotaped during 3 periods: baseline, heel lance, and recovery. Infants were divided into 2 age groups for data analyses: less than and greater than 31 weeks PCA. Mixed model ANOVAs showed that heel lance elicited a stress response (i.e., increased heart rate, decreased oxygen saturation, increased state-of-arousal, and increased facial actions indicative of pain) in both age groups. The stress response was greater in the older group. During recovery, the older group had a more rapid return of heart rate, behavioural state, and facial expressions of pain to baseline levels in the presence of compared to the absence of music. It was concluded that music is an effective NICU intervention following a stress-provoking stimulus in infants older than 31 weeks PCA.

Color discrimination under chronic hypoxic conditions (simulated climb "Everest-Comex 97")

Hypoxia is known to alter visual functions. In the present study, the effects of chronic hypobaric hypoxia upon visual color discrimination were studied in 8 subjects participating in a simulated climb from sea level (PO2 = 210 hPa) to 8,848 m (PO2 = 70 hPa) over a 31-day period of confinement in a decompression chamber ('Everst-Comex 97'). During these investigations, the subjects were required to discriminate between colors of different hue in the red, blue, and green ranges. Alterations in color discrimination increased slightly but significantly as altitude increased. Impairments occurred mainly in the red and blue ranges. In addition, our results further indicate that color discrimination would be affected only when a minimum threshold of difference between color stimuli is not present. Methodological and physiological implications are discussed.

Adaptogenic activity of Siotone, a polyherbal formulation of Ayurvedic rasayanas

Siotone (ST) is a herbal formulation comprising of Withania somnifera, Ocimum sanctum, Asparagus racemosus, Tribulus terristris and shilajit, all of which are classified in Ayurveda as rasayanas which are reputed to promote physical and mental health, improve defence mechanisms of the body and enhance longevity. These attributes are similar to the modern concept of adaptogenic agents, which are, known to afford protection of the human physiological system against diverse stressors. The present study was undertaken to investigate the adaptogenic activity of ST against chronic unpredictable, but mild, footshock stress induced perturbations in behaviour (depression), glucose metabolism, suppressed male sexual behaviour, immunosuppression and cognitive dysfunction in CF strain albino rats. Gastric ulceration, adrenal gland and spleen weights, ascorbic acid and corticosterone concentrations of adrenal cortex, and plasma corticosterone levels, were used as the stress indices. Panax ginseng (PG) was used as the standard adaptogenic agent for comparison. Additionally, rat brain levels of tribulin, an endogenous endocoid postulated to be involved in stress, were also assessed in terms of endogenous monoamine oxidase (MAO) A and MAOB inhibitory activity. Chronic unpredictable footshock induced marked gastric ulceration, significant increase in adrenal gland weight and plasma corticosterone levels, with concomitant decreases in spleen weight, and concentrations of adrenal gland ascorbic acid and corticosterone. These effects were attenuated by ST (50 and 100 mg/kg, p.o.) and PG (100 mg/kg, p.o.), administered once daily over a period of 14 days, the period of stress induction. Chronic stress also induced glucose intolerance, suppressed male sexual behaviour, induced behavioural depression (Porsolt's swim despair test and learned helplessness test) and cognitive dysfunction (attenuated retention of learning in active and passive avoidance tests), and immunosuppression (leucocyte migration inhibition and sheep RBC challenged increase in paw oedema in sensitized rats). All these chronic stress-induced perturbations were attenuated, dose-dependently by ST (50 and 100 mg/kg, p.o.) and PG (100 mg/kg, p.o.). Chronic stress-induced increase in rat brain tribulin activity was also reversed by these doses of ST and by PG. The results indicate that ST has significant adaptogenic activity, qualitatively comparable to PG, against a variety of behavioural, biochemical and physiological perturbations induced by unpredictable stress, which has been proposed to be a better indicator of clinical stress than acute stress parameters. The likely contribution of the individual constituents of ST in the observed adaptogenic action of the polyherbal formulation, have been discussed.

Ethanol, but not the anxiolytic drugs buspirone and diazepam, produces a conditioned place preference in rats exposed to conditioned fear stress

The present study was designed to investigate the role of an anxiolytic effect in the development of a drug-associated place preference in rats exposed to conditioned fear stress, using the conditioned place-preference paradigm. The administration of a low dose of ethanol (300 mg/kg, IP) and the anxiolytic drugs, buspirone (1 and 2 mg/kg, IP) and diazepam (1.25 and 2.5 mg/kg, IP), did not produce a place preference in rats that were not exposed to conditioned fear stress. In rats that were exposed to conditioned fear stress, ethanol produced a significant place preference, while buspirone and diazepam failed to produce a place preference. In addition, ethanol, buspirone, and diazepam produced no place preference in rats treated with an anxiogenic dose of pentylenetetrazole (20 mg/kg, IP). A significant decrease in locomotor activity was observed in rats exposed to conditioned fear stress. Ethanol, but not buspirone and diazepam, significantly recovered or increased locomotor activity in rats exposed to conditioned fear stress. Further, the locomotor-stimulating effect of ethanol was markedly enhanced by repeated exposure to conditioned fear stress. These results suggest that the stimulating effect may be strongly related to the development of the rewarding effect of a low dose of ethanol under psychological stress, and that the conditioned place preference paradigm with conditioned fear stress may be useful for studying the rewarding mechanism of ethanol with regard to the interaction between ethanol and psychological stress.

The relationship of parental alcoholism and family dysfunction to stress among college students

The relationship between collegiate adult children of alcoholics (ACOAs) and adult children from dysfunctional families (ACDFs) was examined to determine whether ACOAs and ACDFs were at greater risk of stress than non-ACOAs and non-ACDFs. The participants were 549 students from a midwestern university. The data collection instruments were the Children of Alcoholics Screening Test, 6-Item Version (CAST-6); the Family Adaptability and Cohesion Evaluation Scales, Version II (FACES-II); and the Perceived Stress Scale (PSS). A substantial proportion of the sample was classified as ACOA, ACDF, or both, and there was considerable overlap between the two groups. Both ACOA and ACDF status were found to be significant predictors of stress, with ACDF status being a better predictor than ACOA status. Possible explanations for the results and implications for collegiate wellness programs are discussed.

Stress assessment by means of questionnaires

A comprehensive methodology for the measurement of stress comprises objective physiological and biochemical methods as well as application of self-reporting scales. This overview focuses on the subjective procedures, their psycho-physiological theoretical background and practical issues. We discuss the most valuable procedures used to assess stress factors, reactions to stress and relationships between the stressed subject and the physical and psychosocial environment. The strengths and limitations of self-reports and the conditions to obtain reliable data and to interpret the findings are outlined. The results of several investigations performed by our teams concern especially the assessment of occupational stress.

THE CANNABINOID AGONIST HU 210 MODIFIES RAT BEHAVIOURAL RESPONSES TO NOVELTY AND STRESS

Experiments were performed on groups of rats after acute and sub-chronic treatment (once daily for 9 days) with the cannabinoid agonist HU 210 (25-100 µg kg(-1), i.p.) as well as 24 h and 7 days after the last drug injection. The animals underwent three behavioural tests in novel environments. In the observation cages (Test 1), rat locomotor activity was found to be dose-dependently reduced after acute and sub-chronic treatment at all doses and virtually unchanged during abstinence; grooming was potently inhibited by acute treatment but potentiated by the sub-chronic one at doses of 50 and 100 µg kg(-1), the effect of the higher dose persisting after 24 h and 7 days abstinence. Vocalization in animals in response to a tactile stimulus was highest after HU 210 at 100 µg kg(-1)in all experimental modes except after 7 days abstinence. In the X-maze (Test 2), sub-chronic HU 210 dose- dependently enhanced rat natural aversion for open arms, and this behaviour persisted during abstinence after the highest dose. Grooming in the X-maze was completely absent in rats acutely injected with HU 210 but potentiated in those sub-chronically treated or abstinent. In the swimming test (Test 3) rats sub-chronically treated at 50 and 100 pg kg(-1)displayed relevant wall-hugging and the same occurred 24 h after last injection. On the whole, our results are indicative of an anxiogenic-like effect of sub-chronic HU 210 at high doses and reflect the persistence of enhanced emotional response to novel environments when the treatment is discontinued. 2000 Academic Press@p$hr Copyright 2000 Academic Press.

Behavioral mechanisms underlying the link between smoking and drinking

Many people use both alcohol and nicotine (i.e., cigarettes and other tobacco products). The behavioral effects of these two drugs differ, and they do not act on the same target sites in the brain, although they may share, or partly share, certain properties. The initiation of alcohol or nicotine use may be precipitated by similar personality characteristics in the user, such as impulsivity and sensation seeking. Moreover, the mechanisms underlying the development of dependence may be similar for alcohol and nicotine. Thus, certain factors, such as reinforcing drug effects, conditioning processes, automatic behavior, and stress, may influence the development of dependence on both drugs. Other factors, such as tolerance and sensitization to the drugs' actions and the development of withdrawal symptoms, may also contribute to dependence. This review discusses the actions of the two drugs on certain brain chemical (i.e., neurotransmitter) systems and the extent to which the effects of the two drugs may interact.

Multigenerational caregiving and well-being: distress of middle-aged daughters providing assistance to elderly parents

This article investigates whether being a caregiver of an elderly parent and the caregiver's involvement in multiple roles increases distress in middle-aged women. Previous studies assumed that providing care to frail parents causes distress in women, in particular when they have other social roles as well. Longitudinal data were collected within a cohort of middle-aged women (n = 934; n = 743). The acquisition or loss of the caregiver role did not appear to affect levels of distress of middle-aged women, nor did additional roles of caregivers increase distress levels or caregiver role strain. Most distressed were women not performing any major social role, suggesting that the lack of social roles rather than the multiplicity of roles is associated with distress. The caregiver role might even reduce distress when women have very few other roles. Findings are explained in terms of the role scarcity, the role expansion and role accumulation hypotheses of role theory.

Effect of acute and chronic stress restraint on amphetamine-associated place preference: involvement of dopamine D(1) and D(2) receptors

The purpose of this study was to determine the D-amphetamine (1.0, 1. 5 and 2 mg/kg i.p.)-induced place preference in rats pre-exposed to acute or chronic restraint stress, using the conditioned place preference model. We also studied the involvement of opioid and dopamine mechanisms in the acute restraint stress-induced increase of D-amphetamine-induced place preference. A single restraint session (2 h) but not chronic restraint (2 h/day for 7 days) leading to adaptation to the stressor, enhanced the D-amphetamine-induced place preference. This enhancing effect was prevented by haloperidol administration (0.4 mg/kg i.p.), (+/-)-sulpiride (60 mg/kg i.p.) or R(+)-SCH-23390 hydrochloride (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4, 5-tetrahydro-1H-3-benzazepine hydrochloride, 30 microg/kg i.p.) 10-20 min prior to the acute restraint session. However, naltrexone pretreatment (1 or 2 mg/kg i.p.) failed to prevent the acute restraint-induced enhancement of D-amphetamine-induced place preference. These results suggest that: (1) the enhancement of D-amphetamine-induced place preference occurred after a single restraint stress but not following chronic restraint stress, (2) the stimulation of both dopamine D(1) and D(2) receptors is necessary for the development of single restraint stress-induced enhancement of D-amphetamine-induced place preference and (3) apparently, an opioid system is not involved in this acute restraint-induced effect.

Sex-dependent behavioral effects of the neurosteroid allopregnanolone (3alpha,5alpha-THP) in neonatal and adult rats after postnatal stress

The neuroactive steroid allopregnanolone (3a-hydroxy-5a-pregnan-20-one, 3alpha,5alpha-THP) has been shown to be involved in the central nervous system's response to stress. This experiment investigated whether response to the neuroactive steroid allopregnanolone, a positive modulator of the GABA(A) receptor, would be altered in neonatal or adult rats previously exposed to a chronic stressor-daily maternal separation during the first week of life. Subjects were then tested either as neonates or adults. In neonates, allopregnanolone decreased the number of ultrasonic vocalizations after brief maternal separation. Previously separated subjects vocalized less and were less active than controls, but were not more sensitive to allopregnanolone on either measure. In adulthood, subjects with a prior history of maternal separation had a greater grooming response to a novel environment after a 10-min cold water swim test than nonseparated subjects. Allopregnanolone reduced grooming, but, again, there was no difference due to stress history. A significant effect of gender was noted in the adult subjects--females were largely responsible for the effects reported. These results suggest that early maternal separation stress can produce an habituation response in neonates and a long-term sensitization response to later novel stress in adults. However, because the behavioral effects of allopregnanolone were not differentially influenced by this early stress history, the neuroactive steroid/GABA(A) receptor complex may not be the major mediator of these early stress sequela. Results indicating that females were more responsive to allopregnanolone than males are discussed in light of previous findings.

Stress and coping: the psychoneuroimmunology of HIV/AIDS

A considerable body of evidence, reviewed in this chapter, suggests that psychosocial factors play an important role in progression of HIV infection, its morbidity and mortality. Psychosocial influences relating to faster disease progression include life-event stress, sustained depression, denial/avoidance coping, concealment of gay identity (unless one is rejection-sensitive), and negative expectancies. Conversely, protective psychosocial factors include active coping, finding new meaning, and stress management. In studying long survivors of HIV/AIDS, our group has found protective effects on health of life involvement, collaborative relationship with doctor, emotional expression, depression (conversely), and perceived stress (conversely). Reviewed and discussed are psychoneuroimmunological pathways by which immune and neuroendocrine mechanisms might link psychosocial factors with health and long survival. Finally, biological factors are also a major determinant of disease progression and include genetics and age of the host, viral strain and virulence, medication and several immune response factors on which psychosocial influences could impact.

Incidence of Epstein-Barr virus in astronaut saliva during spaceflight

BACKGROUND

Astronauts experience psychological and physical stresses that may result in reactivation of latent viruses during space-flight, potentially increasing the risk of disease among crewmembers.

HYPOTHESIS

The shedding of Epstein-Barr virus (EBV) in the saliva of astronauts will increase during spaceflight.

METHODS

A total of 534 saliva specimens were collected from 11 EBV-seropositive astronauts before, during, and after four space shuttle missions. The presence of EBV DNA in saliva, assessed by polymerase chain reaction (PCR), was used to determine shedding patterns before, during, and after space-flight.

RESULTS

EBV DNA was detected more frequently before flight than during (p < 0.001) or after (p < 0.01) flight. No significant difference between the inflight and postflight periods was detected in the frequency of occurrence of EBV DNA.

CONCLUSIONS

The increased frequency of shedding of EBV before flight suggests that stress levels may be greater before launch than during or after spaceflight.

[The estimation of the severity and stressfulness of the work process in industrial medicine]

Underestimation of physical and psychoemotional occupational hazards that are widespread now during social and hygienic monitoring takes place in sanitary and epidemiologic service and in higher and comprehensive education.

Stress system response and rheumatoid arthritis: a multilevel approach

A growing body of research indicates that the stress system, and its interactions with the immune system, play a pivotal role in the aetiology and progression of rheumatoid arthritis (RA). The stress system has multiple levels and comprises physiological, psychological and environmental components. However, most investigations in RA that involve the stress system tend to focus on the interrelationships between neuroendocrine and immune function, and related disease activity, with little regard for the role of other aspects of stress system activation, including psychological variables. This is despite the fact that psychological stressors, and related psychological variables, are known to influence RA disease activity. This article aims to explore the multiple levels of stress system activation and how they may ultimately influence disease-related outcomes in RA. Some measurement issues of psychological stress will also be examined.

Experimentally induced aggressiveness in adult children of alcoholics (ACOAs): preliminary behavioral and neuroendocrine findings

OBJECTIVE

This study was conducted to determine the nature of the reaction of nonalcoholic adult children of alcoholic (ACOA) fathers to the experimental induction of aggression. Of particular interest was the relationship between biochemical factors and personality traits during a stressful event experienced by persons at risk for alcoholism.

METHOD

Aggression was induced by a modified free-operant procedure in 14 ACOA and 14 non-ACOA subjects between 18 and 19 years of age with men and women represented in equal numbers. Neurotransmitter-hormonal assays from blood drawn immediately before, and 20 and 30 minutes after, starting the test included norepinephrine (NE), epinephrine (EPI), prolactin (PRL), growth hormone (GH) and cortisol (Cort). Personality traits were assessed by the Minnesota Multiphasic Personality Inventory (MMPI) Tridimensional Personality Questionnaire (TPQ) and the Buss-Durkee Hostility Inventory (BDHI).

RESULTS

During the aggression induction session, ACOAs gained (F = 4.6, 1/13 df, p < .05) and subtracted (F = 9.2, 1/13 df, p < .005) significantly less money than non-ACOAs, evidence of lower outward-directed aggressiveness among ACOAs. Higher baseline plasma levels of Cort (F = 9.8, 1/13 df, p < .01) and PRL (F = 4.0, 1/13 df, p < .05) and decreased NE (F = 8.5, 1/13 df, p < .005) and GH (F = 10.9, 1/13 df, p < .001) responses during the experimental session were observed. On personality measures ACOAs scored higher than non-ACOAs on MMPI hysteria (F = 10.8, 1/13 df, p < .005), hypochondria (F = 20.1, 1/13 df, p < .001) and paranoia (F = 4.7, 1/13 df, p < 0.5) subscales, on the TPQ reward dependence (F = 10.9, 1/13 df, p < .005) subscale and on BDHI guilt (F = 15.7, 1/13 df, p < .001) and resentment (F = 6.4, 1/13 df, p < .05) subscales.

CONCLUSION

These findings, preliminary in nature, support a hypothesis of inhibition of state and trait aggression in ACOAs in association with monoaminergic and endocrine changes.

The effects of neonatal stress on brain development: implications for psychopathology

Recent studies have focused on the behavioral and neurobiological sequella of exposure to early adverse events. We hypothesize that early adverse experiences result in an increased sensitivity to the effects of stress later in life and render an individual vulnerable to stress-related psychiatric disorders. This vulnerability may be mediated by persistent changes in corticotropin-releasing-factor (CRF)-containing neurons, the hypothalamic-pituitary-adrenal axis, and the sympathetic nervous system. We therefore present an overview of the CRF system and its role as a mediator in the development of the stress response, major depression, and posttraumatic stress disorder. The literature pertaining to behavioral and neurobiological alterations associated with exposure to early adverse life events in rodents, nonhuman primates, and humans is reviewed. We focus on animal models that precipitate depressive and anxiety symptoms while producing neuroendocrine alterations that mimic those seen in adults with those disorders. The literature integrating neurobiological and behavioral consequences of early life stress is also reviewed, focusing primarily on infants born to mothers with depression and on infants who were abused or neglected.

Heart rate and behavioural responses of crib-biting horses to two acute stressors

The heart rate and behaviour of 14 adult saddle horses, eight crib-biters and six normal controls, were investigated. Initially, the relationship between crib-biting and heart rate was investigated while the horses were undisturbed. The horses were tested when restrained with a lip twitch, and assessed when they were exposed suddenly to the rapid inflation of a balloon. The heart rate of the crib-biters during crib-biting was lower than during other behaviours. The crib-biters had a higher overall mean heart rate (P<0.05) suggesting that they may have had a higher basal sympathetic activity. After the application of the twitch, all the horses had a transient increase in heart rate which returned to basal values more rapidly in the crib-biters. The crib-biters were less reactive to the lip twitch, five of the six investigated remaining calm, and after the release of the twitch, they spent more time nibbling (P<0.05) than the control horses. The crib-biters reacted more strongly to the inflation of the balloon (three of the six reacted), and after it had been inflated they spent more time walking in the box.