John Axelsson - Academia.edu (original) (raw)

Papers by John Axelsson

Brain, behavior, and immunity, Jan 5, 2014

Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, a... more Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, and has been proposed to be central in clinical pain conditions. Women are overrepresented in many chronic pain conditions, but experimental studies on sex differences in pain regulation during systemic inflammation are still scarce. In two randomized and double blind placebo controlled experiments, we used low doses of lipopolysaccharide (LPS) as an experimental model of systemic inflammation. The first study employed 0.8ng/kg LPS in a within-subject design of 8 individuals (1 woman), and the second study 0.6ng/kg LPS in a between-subject design of 52 participants (29 women). We investigated the effect on (a) pressure, heat, and cold pain thresholds, (b) suprathreshold noxious heat and cold sensitivity, and (c) conditioned pain modulation (CPM), and differences between men and women. LPS induced significantly lower pressure pain thresholds as compared to placebo (mean change with the 0.8...

Sleep, 2009

Sleep reduction normally causes a homeostatic response during subsequent recovery sleep, but this... more Sleep reduction normally causes a homeostatic response during subsequent recovery sleep, but this does not seem to be true for repeated partial sleep loss. The aim of the present study was to test the response to repeated partial sleep loss through detailed focus on spectral data and parts of sleep. The experiment involved 4 h of sleep across 5 days in the laboratory (partial sleep deprivation [PSD]), followed by 3 days of recovery sleep. PSD was achieved through a delayed bedtime. Nine individuals participated. To avoid "laboratory monotony," subjects were permitted to leave the lab for a few hours each day. All sleep stages and the latencies to sleep and slow wave sleep (SWS) showed a significant reduction during PSD. However, SWS and TST (total sleep time) during the first half of sleep increased gradually across days with PSD. During the first recovery sleep, SWS was significantly increased, while stage 1 and latency to stage 3 were reduced. All were back to baseline o...

Sleep, 2004

Burnout is a growing health problem in Western society. This study aimed to investigate sleep in ... more Burnout is a growing health problem in Western society. This study aimed to investigate sleep in subjects scoring high on burnout but still at work. The purpose was also to study the diurnal pattern of sleepiness, as well as ratings of work stress and mood in groups with different burnout scores. Sleep was recorded in 2 groups (high vs low on burnout) during 2 nights; 1 before a workday and 1 before a day off, in a balanced order. Sleepiness ratings as well as daytime diary ratings were analyzed for the workday and the day off after the sleep recordings. The polysomnographic recordings were made in the subjects' home. Twenty-four healthy individuals (14 women and 10 men) between the ages of 24 and 43 years participated. N/A. A higher frequency of arousals during sleep (Workday: high burnout = 12+/-1 per hour, low burnout = 8+/-1 per hour; Day off: high burnout = 12+/-2 per hour, low burnout =8+/-1 per hour), and more subjective awakening problems were found in the high-burnout g...

Journal of applied physiology (Bethesda, Md. : 1985), 2003

Although the literature claims that shift work is harmful, it overlooks the fact that that many s... more Although the literature claims that shift work is harmful, it overlooks the fact that that many shift workers are satisfied and stay healthy. There is little knowledge of the biological mechanisms mediating the differences in susceptibility. The present study compared satisfied and dissatisfied shift workers with respect to major anabolic and catabolic hormones. Forty-two male shift workers, with an extremely rapidly rotating shift schedule, were divided into two groups according to their ratings of satisfaction with their work hours. Morning blood samples were taken during the first and last morning shift in the shift cycle. Serum was analyzed with respect to testosterone, cortisol, and prolactin. Dissatisfied shift workers had lower morning testosterone than satisfied ones, but they did not significantly differ with respect to cortisol or prolactin. Low testosterone levels were, in addition, associated with a greater sleep need, disturbed sleep/wakefulness, and an increased need f...

Behavioral Sleep Medicine, 2014

This study aimed to examine the association between polysomnographic sleep and subjective habitua... more This study aimed to examine the association between polysomnographic sleep and subjective habitual sleep quality and restoration from sleep. Thirty-one normal sleepers completed the Karolinska Sleep Questionnaire and multiple home polysomnography recordings (n = 2-5). Using linear regression, sleep quality and restoration were separately analyzed as functions of standard polysomnography parameters: sleep efficiency, total sleep time, sleep latency, stage 1 and 2 sleep, slow-wave sleep, rapid eye movement sleep, wake time after sleep onset, and awakenings (n), averaged across recordings. Stage 2 and slow-wave sleep predicted worse and better sleep quality, respectively. Also, slow-wave sleep predicted less subjective restoration, although adjustment for age attenuated this relation. Our findings lend some physiological validity to ratings of habitual sleep quality in normal sleepers. Data were less supportive of a physiological correlate of ratings of restoration from sleep.

Transportation Research Part F: Traffic Psychology and Behaviour, 2000

In the literature recovery after work is taken for granted ± one has 16 h o between work bouts an... more In the literature recovery after work is taken for granted ± one has 16 h o between work bouts and one has 36 h o each weekend. However, the situation for those working irregular work hours may be quite dierent because of night work, long shifts, or long sequences of working days. Strictly speaking we don't have any scienti®c support for theories on how recovery days should be patterned. This paper, therefore, brings together data from a series of our own studies that involve irregular work hours, with the speci®c purpose of looking at the recovery process. The results show that for the average normal oce week worker two days of recovery are normally sucient. For those who work long shifts in long sequences three days are needed for normalization, whereas 12 h shifts in 2±3 day sequences seem not to cause accumulated fatigue. Interestingly, fatigue/sleepiness is often at its peak during the ®rst day of recovery ± not the last day of the working week. Air crew and oil rig workers take a longer time to recover, probably because of too much adjustment of the biological clock. As a rule, long haul air crew is usually much more fatigued than short haul crew during their days o, despite the fact that long haul¯ying is voluntary and opted for by those who¯y it. Also train drivers are aected during their days o by their irregular work hours ± in particular backwards rotating schedules seem to cause accumulation of fatigue. The results suggest that one day of recovery never is sucient, two days usually is, whereas 3±4 days are necessary after periods of severely disturbed circadian rhythmicity. Ó

Health Effects of the New Labour Market, 2002

Shift worker’ attitude to work hours is determined by insufficient time for social activities, an... more Shift worker’ attitude to work hours is determined by insufficient time for social activities, and ratings of poor sleep quality and sleepiness, whereas the attitude to the work situation is determined by psychosocial work factors. The aim of the present paper was to examine whether this is also seen in a group of day time workers. Secondly, we investigated whether

Somnologie - Schlafforschung und Schlafmedizin, 2008