Stress and sensitization in children: a controlled prospective psychophysiological study of children exposed to international relocation.

This controlled prospective study investigated the development of sensitization as a result of international relocation in children, using the analyzing system Phadiatop. The effects of climate and predisposition to allergy were also measured. Children were examined prior to and during their first year of living abroad. A control group living at home was also examined during the same period. Participants answered a questionnaire before and after 1 year abroad, and blood samples were collected to determine sensitization. Before going abroad, there were no significant differences in atopic sensitization between groups nor in other key variables. After 1 year abroad, the proportion of children showing sensitization had increased significantly as compared with the control group at home. The exposed group reported an increase in skin symptoms during the year abroad. This study suggests that unidentified factors associated with foreign relocation increase the risk of sensitization in predisposed children. Stress might be one factor.

A nonconventional approach to the treatment of "environmental illness".

Twenty patients with symptoms of "environmental illness" were subject to a controlled study of deep versus superficial acupuncture. The patients were evaluated by a detailed questionnaire concerning their occupational, environmental, and medical history. Blood samples were taken as well. Patients were randomized to deep or superficial acupuncture. Both groups improved significantly in key variables during and after treatment. There were no group differences. There were no changes in biological variables apart from a gradual and continuous increase in serum cortisol and a decrease in neuropeptide Y, which was somewhat more accentuated in those receiving deep acupuncture. This rise in cortisol may have contributed to decreased dermal symptoms among the participants. It is hypothesized that the positive treatment results observed are partly due to weakening of the conditioned response, linking bodily symptoms to environmental agents. To date, a number of different methods have been tried in the management of patients with environmental illness. However, only rarely have the treatments been evaluated in controlled studies.

Recovery within day-time sleep after slow wave sleep suppression.

Six subjects had their SWS activity suppressed by acoustic stimulation during a day-time (11.00 h) recovery sleep after a 4 h night sleep (03.00-07.00 h). Sleep was disturbed for a period corresponding to 90% of the duration of a preceding undisturbed baseline sleep (also at 11.00 h and preceded by a 4 h night sleep) and thereafter allowed to continue undisturbed until spontaneous awakening. The results showed that SWS and EEG power density were significantly reduced during suppression and that full recovery occurred before spontaneous awakening. The disturbed sleep was significantly longer than the baseline sleep. The increase in duration consisted mainly of SWS, stage 2 and REM. The results suggest that the suppression of SWS activity caused a need for an extension of sleep in order to allow recovery.

Psychophysiological reactions to international adjustment. Results from a controlled, longitudinal study.

BACKGROUND: This controlled prospective study examines psychophysiological reactions in employees during their first and second year abroad to identify individual as well as work-related factors predictive of positive adjustment. METHODS: Employees (n = 47) relocating from Sweden to a foreign country on a work-related assignment were followed. The subjects completed a questionnaire before relocation and after 1 and 2 years abroad. Blood samples were collected for determination of the stressor-related hormones prolactin, cortisol and testosterone. A matched non-moving reference group of employees (n = 35) responded to the questionnaire at similar time periods, and also provided blood samples. RESULTS: During the years abroad, the expatriate employees experienced increased psychosocial stress as well as negative adjustment as reflected in circulating levels of prolactin and testosterone, worse mental well-being and worsening subjective work environment, as compared with the non-moving group. The greatest change occurred during the first year. Individual factors such as social support, internal locus of control, self-esteem and sense of coherence modified the stress response and predicted employees' ability to adjust to foreign assignments. Negative changes in the psychosocial work environment explained to a large degree the decrease in work adjustment during the first year and these findings were also reflected in physiological stress indicators. CONCLUSIONS: The study emphasises the importance for multinational organisations to look at these individual characteristics before sending employees abroad. They also need to get more involved in supporting employees to manage stressors characteristic of the first year of foreign work.

Urinary catecholamine responses to basic types of physical activity.

Urinary adrenaline, noradrenaline, heart rate, and subjective ratings were obtained from 9 healthy males during six different physical activities, ranging in intensity from lying down to running. Heart rate, subjective ratings and noradrenaline excretion reflected the work load in the different conditions. Adrenaline, on the other hand, failed to show this relationship. There was no significant increase in adrenaline excretion even at the highest work load (corresponding to a heart rate of 160 bpm). It was concluded that urinary adrenaline may safely be used as an indicator of mental factors even in situations with different levels of physical activity.

Physicians during and following night call duty--41 hour ambulatory recording of sleep.

Six house officers at two Stockholm hospitals were subjected to 41 h of continuous ambulatory recording of EEG and EOG in connection with night call duty, and to 24 h in connection with normal day work. The results showed that night call duty greatly interfered with sleep, reducing its duration to 4 h. The reduction mainly affected sleep stages 2 and REM. SWS was not affected, whereas EEG spectral power density in the 0.5-7.9 Hz band was suppressed. During subsequent time off, napping and night sleep increased total sleep length above baseline levels. It was concluded that night call duty of the present type causes considerable sleep loss.

Catecholamine measurements in urine by high-performance liquid chromatography with amperometric detection--comparison with an autoanalyser fluorescence method.

In order to validate different methods of measuring urinary catecholamines (norepinephrine, epinephrine and dopamine) in humans, methods based on separation of catecholamines using reversed-phase or cation-exchange high-performance liquid chromatography with electrochemical detection were compared with an autoanalyser-based fluorescence method. Different methods for pre-chromatography sample purification were also studied. For measurements of urinary catecholamines, the reversed-phase-based chromatographic techniques studied were found to give less reliable results than cation-exchange chromatography, even if one of them (Clin Rep Urine Catecholamine Kit) gave almost as precise estimates. The autoanalyser technique yielded good results. It is concluded that cation-exchange chromatography with an appropriate sample work-up procedure (a combination of organic solvent extraction and alumina adsorption) is a reliable and accurate method for analyses of urinary catecholamines.