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Biomedical subjects

J Zulley

Publications and source records attributed to J Zulley.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Falling asleep at the wheel: the chief cause of severe traffic accidents].

All fatal traffic accidents on highways in Bavaria in 1991 have been analyzed. The most frequent single cause for the 204 accidents was falling asleep (24%). A time of day analysis revealed that the highest accidents frequencies could be observed at 6:00 a.m. and 2:00 p.m. In addition an age effect could be observed. The majority of the day accidents were caused by older drivers, while most of the night accidents were caused by younger ones.

Accidents, Traffic↗
PubMed1995

[Effect of treatment of patients with sleep apnea with a nCPAP device on stress coping and well-being].

This study analyzed the influence of CPAP-Treatment on stress coping and well-being in sleep apnea patients. 20 patients with sleep apnea were examined using a stress coping questionnaire ("Stressverarbeitungsfragebogen" of Janke, Erdmann, and Kallus, 1985) and the Scale of Well-Being ("Befindlichkeitsskala" of von Zerssen, 1976). Results showed an improvement in the stress coping mechanism following CPAP treatment. In addition, prior to treatment apnea patients exhibited significantly worse mood compared to that of the control group. Treatment with CPAP significantly improved the mood of apnea patients.

Adaptation, Psychological↗
PubMed1993

Sleep and circadian rhythm during a short space mission.

An experiment was conducted to assess sleep and circadian regulation in an orbiting spacecraft. In orbit the weakened influence of 24-h zeitgebers could result in delayed circadian phases with the possibility of a transition to free-running circadian rhythms. This and the specific stressors of a space mission may lead to changes in ultradian sleep regulation and in reduced sleep quantity and quality. During the mission sleep was recorded polygraphically on tape, as was body temperature. Daytime alertness was rated subjectively by a mood questionnaire. For comparison the same parameters were measured during a baseline period preceding the space mission. The circadian rhythms of body temperature and alertness were found to be delayed in space compared to baseline. This may mark a phase shift or the transition to a circadian state of free-run. Sleep was shorter and more disturbed. The structure of sleep was significantly altered. In space REM latency was shorter, there was less REM sleep in the second non-REM/REM cycle, and slow-wave sleep was redistributed from the first to the second cycle. The self-assessed mood resembled sleep disturbances and adaptation to the space environment. Reduced sleep quality and quantity are likely to result in fatigue and lower daytime performance. Countermeasures should be adopted to improve sleep of astronauts.

Body Temperature↗
PubMed1993

When the human circadian system is caught napping: evidence for endogenous rhythms close to 24 hours.

It is now well acknowledged that napping constitutes an inherent component of the human circadian system. To date, however, few studies have examined the effects of spontaneous napping on human free-running rhythms. This study investigated the free-running circadian periods of rest/activity and body core temperature in a group of young subjects who were permitted to nap during their time in isolation. Based on the frequency of self-reported sleep bouts, subjects were classified as Nappers or Nonnappers. Nappers exhibited free-running rhythms in both rest/activity and body core temperature that were not significantly different from 24 hours. Nappers showed a tendency for shorter free-running periods in both variables, when compared with Nonnappers. These findings emphasize the need for careful reassessment of data obtained from traditional free-run protocols.

Adult↗
PubMed1992

Forced splitting of human sleep in free-running rhythms.

The assumption of polyphasic sleep/wake regulation is based on the occurrence of nap-sleep at specific phase positions in the circadian cycle. Further support would be the split of the normal long major sleep episode into shorter components. Evidence for this hypothesis comes from the discovery of bimodal distribution in sleep duration. An experimental approach to test this hypothesis has been carried out by restricting sleep duration in free-running rhythms. The outcome was a biphasic distribution of sleep within a circadian cycle with sections of dissociation and synchronization of the two sleep blocks. The results show similarities with 'splitting', a phenomenon which has been found in animal studies. The relatively short duration of the different sections as well as the asymmetric distribution of the two sleep blocks in the circadian cycle leads to the assumption of a splitting of the major sleep episode and not of the circadian rhythm. Sleep split into two, relatively short sleep episodes of comparable duration contrasts with napping, which is characterized by an extra sleep episode in addition to the long major sleep.

Journal Article↗
PubMed1990

A polysomnographic study in young psychiatric inpatients: major depression, anorexia nervosa, bulimia nervosa.

The baseline EEG sleep patterns of 10 young depressed patients, 20 patients with anorexia nervosa, 10 patients with bulimia nervosa, and 10 healthy subjects were found to be indistinguishable, except for an increased REM density in the depressed patients. In eating disorder patients, a concomitant major depressive episode had no influence on EEG sleep. The results of the cholinergic REM sleep induction test revealed a significantly faster induction of REM sleep in the depressed patients when compared with the eating disorder patients and the control subjects. This indicates a subthreshold hypersensitivity of the REM sleep triggering cholinergic transmitter system in depressives, but not in eating disorder patients.

Adolescent↗
PubMed1989

[Sleep in anorexia nervosa, bulimia nervosa and depressive diseases: a polysomnographic comparative study].

All-night EEG sleep in 20 anorexics, 10 bulimics, 10 endogenous depressives, and in 10 healthy subjects (all age matched) was compared. In addition, the REM sleep-induction-test was performed in 12 patients with an eating disorder, 7 depressives, and 12 controls by application of the cholinergic agent RS 86. During baseline night, EEG-sleep parameters, especially REM latency, did not differ between the patients and the controls, except for the phasic components of REM sleep (REM density) that were increased in the depressive patients. The frequency of shortened REM latencies, however, was significantly higher in the depressed patients. These observations indicate that in some of the young depressives the disturbance of the REM sleep regulating transmitter system is already present to a similar degree as it is assumed in elderly depressives. After the application of RS 86, REM latency was shortened in all groups under investigation. However, the REM sleep inducing effect of RS 86 was significantly more pronounced in the depressives when compared with both the eating disorder patients and the controls. In the latter two samples, the shortening of REM latency was similar. Furthermore, the eating disorder patients with a concomitant major depression reacted similar to RS 86 as the non-depressed eating disorder patients and the control subjects. Whereas baseline EEG-sleep did not differ significantly among eating disorder patients, young depressives, and healthy subjects, the REM sleep inducing effect of the cholinergic agent RS 86 clearly distinguished between the depressives and both the patients suffering from eating disorders and the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Evidence for circadian influence on human slow wave sleep during daytime sleep episodes.

The occurrence of slow wave sleep within spontaneously initiated daytime sleep episodes was studied to examine hypothesized associations with prior wakefulness and circadian factors. There was a strong relationship between measures of slow wave sleep and the proximity of sleep episodes to the maximum of body core temperature. Those sleep episodes that began within 4 hours of the maximum in body core temperature contained significantly more slow wave sleep than did all other daytime sleep periods, approximating proportions typical of nocturnal sleep. Multiple regression analysis revealed no relationship between measures of slow wave sleep and prior wakefulness. These findings are consistent with an hypothesized approximately-12-hour rhythm in the occurrence of slow wave sleep and they underscore the influence imposed on human sleep by the endogenous circadian timing system.

Adult↗
PubMed1988

Influence of the cholinergic agonist RS 86 on normal sleep: sex and age effects.

In 36 healthy control subjects (21 females, 15 males; age range 18-65 years; mean age 41.8 years, SD 15.6 years), a bedtime dose of 1.5 mg RS 86, an orally acting cholinergic agonist, shortened rapid eye movement (REM) latency, increased REM sleep, and decreased slow-wave sleep. Six of the subjects (greater than 40 years old) even displayed sleep-onset REM periods after the drug. Results of the present study agree well with those of studies using other cholinomimetics (i.e., physostigmine, arecholine) and confirm the importance of the cholinergic system for REM sleep regulation. Since RS 86 mimicked some of the REM sleep abnormalities specific for patients with depressive disorders, the cholinergic system may play a role in the pathogenesis and pathophysiology of depressive diseases.

Adolescent↗
PubMed1988

EEG sleep and the cholinergic REM induction test in anorexic and bulimic patients.

The electroencephalographic (EEG) sleep of 20 anorexic patients, 10 bulimic patients, and 10 age-matched healthy controls was studied. In addition, six anorexic patients and six bulimic patients had a cholinergic rapid eye movement (REM) sleep induction test (RIT) performed with the cholinergic agent RS 86. The three samples showed no major differences in sleep patterns. The same held true when attention was focused on patients who additionally met DSM-III criteria for major depression. The RIT results were similar in the patients with eating disorders and in controls, but differed from those reported in depressives. Therefore, the present study found no hints of depression-like sleep patterns in patients with eating disorders.

Adult↗
PubMed1986

Is there a relationship between response to total sleep deprivation and efficacy of clomipramine treatment in depressed patients?

Total sleep deprivation (TSD) and tricyclic medication are successful treatment modalities for patients with a major depressive disorder. Recent studies have suggested a positive relationship between TSD response and succeeding tricyclic treatment, even on a very specific level, thus supporting the assumption of two distinct biochemical subtypes of depression. The present study tested this hypothesis by treating 10 inpatients with a major depressive disorder first with TSD and succeedingly with clomipramine. Contrary to expectation, a negative relationship between clinical response to the two treatment modalities was found.

Adolescent↗
PubMed1985

Napping behavior during "spontaneous internal desynchronization": sleep remains in synchrony with body temperature.

Patterns of sleep and wakefulness exhibited in an environment without time cues are generally considered to be monophasic, with a distinct relationship between sleep episodes and the minimum of body core temperature. In some cases this relationship between major sleep episodes and temperature becomes replaced by an apparently varying phase relationship between the two variables called "spontaneous internal desynchronization". In the present study the sleep-wake and temperature data of six subjects living in an environment without time cues and exhibiting internal desynchronization were reanalyzed to include subjectively designated naps. Two groups of naps were identified based on their phase positions relative to temperature, with one group occurring around the temperature minimum and another group clustering approximately halfway between successive minima. The results support the suggestion that neither monophasic sleep placement nor sleep patterns typically associated with spontaneous internal desynchronization reflect biological sleep tendency. Rather, sleep tendency is reflected more accurately by the bimodal sleep patterns exhibited by subjects who are allowed to time their sleep and waking with no restrictions.

Body Temperature↗
PubMed1981

The dependence of onset and duration of sleep on th circadian rhythm of rectal temperature.

The sleep-wake cycle and the circadian rhythm of rectal temperature were recorded in subjects who lived singly in an isolation unit. In 10 subjects, the freerunning rhythms remained internally synchronized, 10 other subjects showed internal desynchronization. Times of onset and end of bedrest ("sleep") were determined in each cycle and referred to the phase of the temperature rhythm. In the synchronized subjects, onset of sleep occurred, on the average, 1.34 h before the minimum of temperature, and end of sleep 6.94 h thereafter, with narrow distributions. The desynchronized subjects had a broad bimodal distribution of sleep onsets (peaks 6.3 and 1.3 h before the minimum); the duration of sleep varied between more than 15 h when sleep began about 10 h before the temperature minimum, and less than 4 h when sleep began several hours after the minimum. The dependence of sleep duration on body temperature is interpreted as a continuing action of the coupling forces between the two rhythms after mutual synchronization is lost.

Adult↗
PubMed1980

The REM-NREM sleep cycle: renewal process or periodically driven process?

The question of the serial dependence of successive REM-NREM sleep cycles was examined. The experiments were performed in two different settings: 309 sleep episodes of 11 healthy young sleepers (age range, 20-36 years) were recorded under entrained conditions in the sleep laboratory; 5 of these subjects also slept in an isolation unit (underground apartment) with free-running sleep-wake cycles for a total of 107 sleep episodes. The covariances between the first three REM-NREM cycles were computed using an intraindividual cross-night approach. Significant negative covariances were observed. This result confirmed the assumption of serial dependencies between successive REM-NREM cycles. These data agree with the features of a periodically driven process and are incompatible with the alternatively hypothesized renewal model. The periodically driven process is similar in concept to the basic rest-activity cycle.

Adult↗
PubMed1980

Distribution of REM sleep in entrained 24 hour and free-running sleep--wake cycles.

One hundred thirty sleep episodes of 6 subjects, living on a natural 24 hr day, were compared with 116 sleep times of the same subjects living isolated from external time cues. The polygraphic sleep recordings were analyzed for the distribution of REM sleep under both conditions. Additionally, the relationship between body temperature and REM sleep was analyzed by comparing sleep episodes in which the temperature minimum occurred early in the sleep episode with those in which there was a late temperature minimum. The results show that there is more REM sleep in the beginning of sleep in sleep episodes of free-running rhythms as compared to sleep episodes of entrained 24 hr rhythms. This higher amount of REM sleep is due to a longer first REM episode and shorter first NREM episodes. The comparison of the sleep episodes that differ in the position of the temperature minimum shows similar differences, i.e., more REM sleep in the beginning of sleep episodes in which the temperature minimum occurs earlier as compared to episodes in which the temperature minimum occurs later. It was hypothesized that the amount of REM sleep depends on the phase relationship between sleep and the circadian temperature cycle. From this point of view, the difference in the distribution of REM sleep in the entrained 24 hr rhythm, on the one hand, and the free-running rhythm, on the other hand, can be explained by the different courses of body temperature during sleep. That only the first REM episode is influenced by circadian parameters may indicate an exceptional role for this REM episode in contrast to the following episodes.

Adult↗