bluuebunny/crossref_metadata_2025 huggingface dataset:
Children of the mentally ill: a qualitative focus group approach
Authors: Garley D. , Gallop R. , Johnston N. , Pipitone J.
Published: November 2003

Children of the mentally ill constitute a group neglected by mental health care providers. Increased rates of psychopathology, impaired attention processes, disturbances in interpersonal relationships, and reduced overall adaptive functioning are reported as significant outcomes for offspring of parents with a mood disorder. While epidemiological studies underscoring the risks from a hereditary standpoint are many, there are few studies examining the subjective experience of living with a depressed parent. Findings from this pilot study elucidate the subjective experience of preadolescents/adolescents living with an affectively ill parent, applying a qualitative focus group design. Videotaped sessions were analysed using methods consistent with qualitative research. ‘Struggle to understand the illness’, ‘managing the illness’, ‘recognizing the signs’, and ‘impact of parent's hospitalization’ emerged as central themes, capturing the essence of participants' experiences. The first two themes were further divided into subthemes. Findings illuminate the need to broaden nursing interventions and research, to include family perspectives, particularly when parental mental illness is a factor.
Variables and designs in psychiatric/mental health nursing research articles published from 1982 to 1992
Authors: Yonge O. , Qiupling Z. , Zaleski J.
Published: November 2003

Research designs and variables of interest were classified in 194 mental health psychiatric articles published between 1982 and 1992. Common variables only could be identified in 100 articles and independent and dependent variables were identified in the remaining 94 articles. The majority of research designs were descriptive. The variables pertained to diverse interests from nurse and patient perspectives, specifically including patients' behavioural responses to illness, care and caregivers. These variables were then compared by the writers to the current research foci as identified in the recent literature. As listed, these are: biological psychiatry; working with the chronically and persistently mentally ill; shifting of care to the community; working with consumers; and outcome research. There is some link between research published between 1982 and 1992 and current trends in design and a few variables of interest. However, current researchers in mental health psychiatric nursing need to change foci and their relationships with other disciplines to ensure relevancy in their research programmes.
Where are we now? Evaluating two decades of group interventions with adult cancer patients
Authors: Bottomley A.
Published: November 2003

Substantial evidence suggests that psychosocial interventions are effective in reducing the psychological distress associated with cancer. As the requirement for more cost‐effective health care becomes a global concern, considerable focus has been directed towards group interventions with cancer patients. This review examines the literature of intervention groups provided across a wide range of approaches used and illustrates the mental health benefits seen from these studies. Methodological limitations in previous work are examined and ways towards improving research using cancer intervention groups are suggested.
Mental illness and criminal behaviour: a literature review
Authors: Anderson M.
Published: November 2003

The purpose of this paper is to review the current literature in relation to mental illness and criminal behaviour. The material presented for discussion was selected from forensic and general psychiatric literature. However, a number of important publications, policy documents and independent reports were used to explore the debate surrounding this subject. Contemporary studies of prison populations in the UK and abroad illustrated the difficulty in relating mental illness to crime. Papers presenting research in the UK revealed important implications for mental health policy and the way in which the penal system deals with mentally disordered offenders. The literature reviewed provided arguments for and against an association between mental illness and criminal behaviour. Methodological problems associated with criminological and psychiatric research were addressed in relation to the exploration of whether people suffering from a mental illness are more dangerous or violent than other people. Research papers focusing on public reaction to mentally ill people living in the community provided important considerations when addressing mental illness and criminal behaviour in the context of care in the community policy. This paper will be of interest to a broad range of mental health professionals, particularly those working with individuals who have a history of mental illness and violent behaviour, or mental health professionals working with mentally disordered offenders.
Understanding the psychological impact of rape and serious sexual assault of men: a literature review
Authors: Rentoul L. , Appleboom N.
Published: November 2003

Until recently, very little attention has been paid to male victims of sexual abuse in childhood and male victims of rape and sexual assault in adulthood. Increasingly, researchers and clinicians are turning their attention to the particular problems encountered by male victims of abuse and sexual assault. Recent changes in British Law have acknowledged the existence of rape of male victims and have highlighted the need to identify the number of male victims of sexual assault and plan appropriate clinical services. A review of the literature reveals very little British empirical research on the psychological impact of rape upon male victims, although the studies that have been carried out provide clear evidence of a wide range of psychological consequences, both in the immediate period following the assault and in the long‐term. Differences and similarities with female victims of rape are discussed. The particular problems encountered by male victims mean that they are even less likely than female victims to report an assault; when they do seek help the most pervasive themes that emerge from the literature concern their problems in reconciling their masculine identity with their experience of being a sexual victim. Issues concerning treatment of male victims are also discussed.
Case management: a week in the life of a clinical case management team
Authors: Waite A. , Carson J. , Cullen D. , Oliver N. , Holloway F. , Missenden K.
Published: November 2003

This paper describes the work of a clinical case management core team (four nurses and an occupational therapist) during the course of a week. Information was gathered through non‐participant observation of the team by two independent researchers. Transcripts produced from the data recorded were examined. From this, seven categories of activity were identified: planned client contact; unplanned client contact; family/carer contact; liaison; administration; team information sharing and supervision, training and personal development. These categories were felt to encompass the range of activities practised by the team. The amount of time that case managers spent engaged in these core functions was calculated. Detailed examples are presented. Results are discussed with reference to Kanter's components and principles of clinical case management.
The nursing process in crisis‐oriented psychiatric home care
Authors: Boomsma J. , Dingemans C. A. J. , Dassen Th. W. N.
Published: November 2003

Crisis‐oriented psychiatric home care is a recent development in the Dutch mental health care system. Because of the difference between psychiatric care in the home and in the hospital, an action research project was initiated. This project was directed at the nursing process and the nurses' role and skills in psychiatric home care. The main goal of the project was to describe and to standardize nursing diagnoses and interventions used in crisis‐oriented and long‐term psychiatric home care. The development of supporting methods of assessment and intervention were also important aspects of this project. In this article a crisis‐oriented psychiatric home care programme and the first developmental research activities within this programme are described. To support the nursing process, the development of a nursing record and an assessment‐format, based on Gordon's Functional Health Patterns (FHP), took place. By means of content analysis of 61 nursing records, the most frequently stated nursing diagnoses, based upon the North American Nursing Diagnosis Association (NANDA) taxonomy, were identified. The psychiatric diagnostic categories of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV) were also collected. The most common categories found were those of mood disorders and schizophrenia or psychotic disorders. Seventy‐five per cent of the nursing diagnoses showed up within four FHP: role‐relationship, coping‐stress tolerance, self‐perception/self‐concept and activity‐exercise. The nursing diagnosis of ‘ineffective individual coping’ was stated most frequently. This is not surprising because of the similarities in the definitions of this nursing diagnosis and the concept of ‘crisis’ to which the psychiatric home care programme is oriented. Further research activities will be focused on standardization of nursing diagnosis and the interventions that nurses undertake in this type of care.
Mental health nursing in the 1950s and 1960s revisited
Authors: Nolan P. , Hopper >.
Published: November 2003

From the post‐War period to the 1960s, immense changes took place in the philosophy, organization and delivery of mental health care in the UK. These changes were driven by the financial burden that Bevan's National Health Service imposed on the British Government, by the dynamism and vision of psychiatrists and mental health nurses returning from the War, and by a new social and cultural consciousness, which put minority groups such as the mentally ill onto the political agenda. This paper seeks to explore some of these complex interactions and to show how the closure of mental hospitals was the inevitable outcome of movements both inside psychiatry and far beyond it. An awareness of the historical context of mental health care can assist planners and providers to avoid the many pitfalls that have been made by our predecessors.
Client‐centred approach to student nurse education in mental health practicum: an inquiry
Authors: Morgan S. , Sanggaran R.
Published: November 2003

This project utilized constructive feedback from clients of mental health facilities as a means of facilitating student nurse learning in three clinical environments. Three questionnaires were utilized to elicit and evaluate the impact of this feedback with a sample of 43 students and 74 client participants. The inquiry demonstrated that clients are willing to participate in students learning and believe that they can contribute towards it. Students also believed that clients have a valuable role to play in their learning, although they note caution in regards to client selection.
Melatonin and insomnia
Authors: ELLIS C.M. , LEMMENS G. , PARKES J.D.
Published: November 2003

The hypnotic action of melatonin 5 mg p.o. was explored in 15 subjects with psychophysiological insomnia in a double‐blind controlled self‐report questionnaire study. Melatonin or placebo was taken at 20.00 hours for a 1‐week period in random order. Effects on sleep and wakefulness were monitored by visual analogue scale and structured interview. Bedtime, sleep onset time, estimated total sleep and wake time, as well as self‐rated sleep quality, were not altered by melatonin, and estimates of next‐day function did not change. The period of melatonin treatment was retrospectively correctly identified by 8 of 15 subjects. Despite unchanged ratings of night sleep quality on the last night of each treatment, 7 of 15 subjects reported that sleep had subjectively improved to a minor extent in the week of active treatment. Side‐effects attributed to melatonin included headache and an odd taste in the mouth. These data indicate that melatonin is probably of no clinical value in the management of psychophysiological insomnia.
The rhythms of human sleep propensity and core body temperature
Authors: LACK LEON , LUSHINGTON KURT
Published: November 2003

Evidence from human free‐running studies has suggested a close relationship between the timing of the circadian rhythm of core body temperature and the rhythm of sleep propensity. However, this relationship may be questioned by variations of sleep and wakeful activity which could have masked the endogenous temperature rhythm. A constant routine was used here to «unmask» the endogenous temperature rhythm in addition to frequent sleep trials across a 24‐h period to confirm the relationship between temperature and sleep propensity rhythms. Of the 14 healthy, good sleeping subjects 13 had significant 24‐h cosine rhythms of sleep propensity. Eight of these also had a significant 12‐h cosine rhythm. The eight subjects with both 24‐h and 12‐h rhythms showed a minor peak of sleep propensity in the early afternoon followed by a trough in the early evening (20.00 hours). Sleep propensity then rose rapidly at about midnight to a major peak in the early morning. This was followed by a second trough of sleep propensity in the late morning. The average times of the sleep propensity phases relative to the circadian temperature rhythm were very similar to the earlier free‐running studies. Furthermore, the times of the sleep propensity phases were highly correlated with the body temperature minimum. These results suggested the possibility that a common oscillator determines the timing of both the body temperature rhythm and the phases of the sleep propensity rhythm.
Behavioural sleep in the giraffe (Giraffa camelopardalis) in a zoological garden
Authors: TOBLER I. , SCHWIERIN B.
Published: November 2003

Behavioural sleep was assessed for 152 nights in 5 adult, 2 immature and 1 juvenile giraffes at a zoological garden, using continuous time‐lapse video recording. Sleep occurred while the giraffes were standing (SS) and in recumbency (RS). Paradoxical sleep (PS) was recognized by the peculiar positioning of the head on the croup and by phasic events. The 24‐h sleep profile had a main bimodal nocturnal sleep period between 20.00 and 07.00 hours, with a trough between 02.00 and 04.00 hours, and several short naps between 12.00 and 16.00 hours. Total sleep time (TST), excluding the juvenile, was 4.6 h, whereby PS comprised only 4.7%. TST was not age dependent, but the lowest amount of RS and the highest amount of SS occurred in the oldest and the two oldest animals, respectively. Sleep was fragmented, as indicated by the predominance of RS episodes lasting less than 11 min. Sleep cycle duration was very variable with most values between 1 and 35 min (when no waking or RS was allowed within PS episodes), or 6–35 min (when the criteria for ending a PS episode allowed 1–2 min interruptions by RS). There were several indications for sleep regulation: (i) RS and SS complemented each other to yield a relatively stable daily value of TST; (ii) sleep was redistributed on nights following a day when the giraffes spent a few hours in an outside enclosure. The first peak of the bimodal sleep profile was absent and RS was more prominent in the second half of the night compared with nights following days spent in the barn; and (iii) napping was followed by a minor reduction of RS and an increase in SS in the subsequent night compared with nights following days without naps.
Inhibition of melatonin secretion onset by low levels of illumination
Authors: TRINDER JOHN , ARMSTRONG STUART , O»BRIEN CATHERINE , LUKE DAVID , MARTIN MARION
Published: November 2003

Melatonin is a hormone released during darkness under the control of the hypothalamic circadian pacemaker. It has been shown that melatonin is suppressed by light as a function of intensity, with low levels of illumination producing small effects and more intense light greater, but not complete inhibition. The studies which lead to these conclusions administered light subsequent to the secretion pattern being well established. Light as low as 250 lux administered during the normal onset of secretion can reduce melatonin to below detectable levels. The onset of melatonin secretion was delayed for at least an hour during 250 lux exposure and did not rise until termination of light exposure (two hours after control melatonin onset) with higher illumination (500, 1000 and 2500 lux). This tentatively indicates that duration of the inhibition is intensity dependent. It is suggested that the experimental paradigm used in the present study may be a more realistic representation of the effect of normal light exposure (both natural and artificial) on the circadian system, and that findings may be pertinent to the aetiology of certain sleep onset insomnias, which would include delayed sleep phase syndrome (DSPS) and adaptation to shift work.
Inducing a 6‐hour phase advance in the elderly: effects on sleep and temperature rhythms
Authors: CARRIER JULIE , MONK TIMOTHY , BUYSSE DANIEL , KUPFER DAVID
Published: November 2003

The aim of this experiment was to study the effects on sleep and temperature rhythms of a 6‐hour (h) phase advance of the sleep/wake cycle in healthy elderly subjects. Twenty‐five subjects (77–91 y.o.) lived in a time‐isolation apartment on an experimenter‐controlled routine for 15 days. The experiment started with five baseline days. The wake time on the 6th night was phase advanced by 6‐h and the routine for the remaining nine days was held constant to the new phase position. After the phase shift, temperature circadian rhythms showed rapid phase adjustment leading to a small (1.1 h) phase angle disturbance. Sleep efficiency decreased and showed little evidence of recovery back to baseline following the phase shift. The amount of wakefulness in the first two hours of sleep increased after the phase shift while no effect was found for the amount of wakefulness in the last two hours of sleep. The 6‐h phase shift did not change the percentages of REM and SWS. Early night sleep propensity appeared to be very sensitive to a small phase angle disturbance of the circadian oscillator in this healthy elderly sample. The phase angle disturbance induced in this study did not seem to be large enough to have a systematic effect on sleep propensity at the end of the night or on REM sleep parameters, suggesting that these variables are less sensitive to an altered phase relationship with the circadian oscillator than early night sleep propensity. These results indicate that there might be a variable phase tolerance for different sleep parameters in older subjects.
Human circadian rhythms in constant dim light (8 lux) with knowledge of clock time
Authors: MIDDLETON BENITA , ARENDT JOSEPHINE , STONE BARBARA
Published: November 2003

The light/dark (L/D) cycle is a major synchronizer of human circadian rhythms. In the absence of a strong L/D cycle, synchrony with 24 hours can nevertheless be maintained in a socially structured environment, as shown in Polar regions (Broadway et al. 1987) and by some blind subjects (Czeisler et al. 1995a). The relative contribution of other time cues to entrainment in dim light has not been fully explored. The present study investigated the behaviour of melatonin (assessed as 6‐sulphatoxymelatonin); rectal temperature; activity and sleep (actigraphy and logs) in constant dim light (L/L) with access to a digital clock. 6 normal healthy males were maintained as a group in partial temporal isolation with attenuated sound and ambient temperature for 21 days. All 6 subjects showed free‐running periodicity for 6‐sulphatoxymelatonin and 5/6 subjects for temperature, activity and sleep offset. The average period (tau) was 24.26±0.049, substantially shorter than in previous experiments with a self selected L/D cycle but similar to a recent study conducted in very dim light. One subject maintained a rigid sleep/wake cycle throughout whilst his 6‐sulphatoxymelatonin rhythm free‐ran. Total sleep time, from actigraph data, did not change but sleep efficiency decreased during the experiment. The subjects did not show group synchronization. These results confirm previous data indicating the importance of the L/D cycle in human entrainment and underline the lesser role of social cues and knowledge of clock time. This particular approach will permit the administration of timed medication to sighted humans under free‐running conditions.
Evaluation of activity‐based techniques to identify transient arousal in respiratory sleep disorders
Authors: DRINNAN M.J. , MURRAY A. , WHITE J.E.S. , SMITHSON A.J. , GIBSON G.J. , GRIFFITHS C.J.
Published: November 2003

Daytime sleepiness and impaired cognitive function can be a consequence of recurrent transient arousal from sleep. Arousal is often associated with abrupt changes in the electroencephalogram (EEG), and such changes can be used as an index of sleep disturbance, but EEG analysis is laborious and requires trained observers. Possible alternative indices of arousal not reliant on EEG analysis were investigated. Recordings were made from 36 sleeping subjects who were being investigated for sleep‐related breathing disorders. In each study awakenings and transient arousals according to EEG criteria were compared with activity in five potential indirect indicators of arousal: wrist movement, ankle movement, left and right tibial electromyogram, and phase change in ribcage‐abdominal movement. The mean values of sensitivity to arousal ranged from only 25 to 45%. However, their high positive predictive accuracies (PPAs, 68 to 92%) indicated that activity, when present, was usually associated with arousal. Sensitivity to awakenings was higher (71–87%), though PPAs were lower (42 to 63%). For the indicator based on ribcage‐abdominal phase, the number of periods of activity showed a significant relation to the number of arousals (r=0.70, P<0.001). It can be concluded that phase changes in chest/abdomen movement are a useful indicator of arousal associated with obstructive apnoea and related conditions. Limb activity has much lower sensitivity for transient arousal, but may be of value in indicating periods of wakefulness.
Day‐time melatonin administration: Effects on core temperature and sleep onset latency
Authors: REID KATHRYN , VAN DEN HEUVEL CAMERON , DAWSON DREW
Published: November 2003

Significant hypothermic and hypnotic effects have been reported for melatonin at a wide range of doses. It has been suggested that this decrease in core temperature (Tc) following melatonin administration may mediate the observed increase in sleepiness. To test this, melatonin was administered to young adults during the day, and the concurrent effects on Tc and sleep onset latency (SOL) were recorded. Sixteen healthy males received either a 5 mg oral formulation of melatonin or placebo at 14.00 hours. Core temperature was recorded continuously. Sleep onset latency to stage 1 (SOL1) and stage 2 (SOL2) were recorded using an hourly multiple sleep latency test (MSLT). Compared with placebo, melatonin significantly decreased Tc 1.5 h after administration for 6 h. Between 15.00 and 18.00 hours, the drop in Tc was associated with a concurrent decrease in SOL1 and SOL2. Following administration mean SOL1 and SOL2 were reduced by 40 and 25%, respectively. In this study, daytime melatonin administration produced a significant decrease in Tc with a corresponding decrease in SOL. Taken together, these data are not inconsistent with the suggestion that melatonin may facilitate sleep onset via a hypothermic effect. In addition, this study provides support for the idea that melatonin may play a role in regulating circadian and/or age‐related variations in sleep/wake propensity. From a practical perspective, exogenous melatonin may be useful in the treatment of sleep disorders associated with increased nocturnal Tc.
Seasonal covariation of the circadian phases of rectal temperature and slow wave sleep onset
Authors: VAN DONGEN HANS , KERKHOF GERARD , KLÖPPEL HEINZ‐BERND
Published: November 2003

There is a scarcity of well‐controlled studies of the seasonal variation in circadian rhythmicity. In the present study, the circadian phase of rectal temperature and the onset of slow wave sleep were studied in a series of twelve 24‐h experiments, one each month of the year, for six healthy subjects under controlled conditions in a climatic chamber. In winter, as compared with summer, the average circadian rhythm of rectal temperature was phase delayed by 45 min, and the average onset of slow wave sleep was phase delayed by 40 min. The temporal relationship between the circadian phase of rectal temperature and the timing of slow wave sleep was maintained throughout the year. Habitual rising and retiring times covaried as well. Furthermore, the circadian rhythm of rectal temperature followed the timing of the photoperiod across the year, but had a much smaller range of seasonal variation. Apparently, the seasonal variation in the photoperiodic zeitgeber is largely compensated for by the stabilizing influence of secondary zeitgebers. However, in healthy subjects some effect of photoperiodic variation can still be observed.
Psychophysiological insomnia: the behavioural model and a neurocognitive perspective
Authors: PERLIS M. L , GILES D. E , MENDELSON W. B , BOOTZIN R. R , WYATT J. K
Published: November 2003

A number of paradoxes are apparent in the assessment and treatment of psychophysiological insomnia and sleep state misperception. Three of these paradoxes exist as discrepancies between polysomnographic (PSG) measures and the subjective impressions regarding sleep quality and quantity. The remaining incongruity exists largely within the objective domain. In the case of subjective–objective discrepancies, patients with insomnia: (1) frequently identify themselves as having been awake when awakened from PSG defined sleep; (2) tend to overestimate sleep latency and underestimate total sleep time as compared with PSG measures; (3) appear to derive more benefit from pharmacotherapy that can be explained by objective gains. The remaining paradox pertains to the observation that hypnotic medications, by and large, do not normalize sleep architecture or produce a more ‘sleep‐like’ EEG. In this paper, we review possible explanations for these various paradoxes, introduce a new perspective and suggest possible research avenues. The model introduced is based on the observation that beta and/or gamma activity (which have been found to be associated with cognitive processes) is enhanced in insomnia at or around sleep onset. We propose that this kind of high frequency EEG activity may interfere with the normal establishment of sleep onset‐related mesograde amnesia. As a result, the patient with insomnia maintains a level of information and/or memory processing that blurs the phenomenological distinction between sleep and wakefulness and influences retrospective judgments about sleep initiation and duration.
Endogenous and exogenous components in the circadian variation of core body temperature in humans
Authors: HIDDINGA A. E , BEERSMA  , VAN DEN HOOFDAKKER R. H
Published: November 2003

Core body temperature is predominantly modulated by endogenous and exogenous components. In the present study we tested whether these two components can be reliably assessed in a protocol which lasts for only 120 h. In this so‐called forced desynchrony protocol, 12 healthy male subjects (age 23.7 ± 1.4 y) were subjected one by one to an artificial light/dark cycle of 20 h (10 lux vs. darkness). Core body temperature was measured continuously. The temperature data were analysed by an iterative method based on the assumption that the endogenous and exogenous components contribute to body temperature in an additive way. The results show that the average temperature curve is an almost perfect addition of the two components. The endogenous component differs from a sinusoid, and the relative contributions of the endogenous and exogenous components to the raw temperature curves differ substantially between the subjects. The average amount of unexplained variance in the individual data was 17%. Averaging of the body temperature curves over subjects reduced the unexplained variance to only 2%. This reduction in unexplained variance upon averaging over subjects must be due to the fact that most of the variance is either differently dependent on circadian phase for the various subjects or not dependent on circadian phase at all. The circadian pacemaker component revealed an average value of tau of 24.30 ± 0.36 h, which is consistent with recent findings in the literature. We conclude that a short forced desynchrony protocol is sufficient for the distinction between the masking and pacemaker components of core body temperature. The same protocol can be used to study the influence of these components on all kinds of other physiological and psychological signals.
Paradoxical sleep as a programming system
Authors: Jouvet Michel
Published: November 2003

The concept of ‘psychological individuation’ i.e ‘intraspecific variability’ is essential for evolution as stated by Mayr (1958). It has been recently revived by the study of Bouchard (1990) in homozygous twins separated at birth and reared in different environments. These twins still retain identical psychological idiosyncratic reactions. Even if their brains are almost identical at birth, it is most likely that the different epigenetic stimuli from the external world have differently altered many cerebral synaptic circuitry due to the plasticity of the brain. Therefore, in order to maintain an identical psychological profile, there should be a mechanism which would reinforce the genetic programmation of the central nervous system either in reinforcing or erasing special genetic circuitry which would be stimulated during previous and/or subsequent waking periods. In ectothermic vertebrates, in immature mammals or sometimes in mature birds, this programming can be effectuated by neurogenesis. After neurogenesis has stopped in mammals, paradoxical sleep would be well suited for reinforcing the genetic programming during sleep. The patterns of portogeniculo‐occipital (PGO) activity (which depend upon genetic factors) would be responsible for this function, together with the theta activity of the hippo‐campus (read out of previous waking events) and fast cortical EEG. This programming would activate all the brain including the pyramidal motor system while movements would be suppressed by the system controlling muscle atonia.
Reactivation of neuronal ensembles in hippocampal dentate gyrus during sleep after spatial experience
Authors: Shen Jiemin , Kudrimoti Hemant , McNaughton Bruce , Barnes Carol
Published: November 2003

Patterns of neuronal activity recorded in CA1 of the hippocampus and in neocortex during waking‐behavior, are reactivated during subsequent slow‐wave sleep (SWS). It has been suggested that this reactivation may originate in the hippocampal CA3 region, where modifiable excitatory recurrent connections are abundant and where sharp‐waves, in which the reactivation is most robust, appear to arise. The present experiment investigated whether ensemble firing patterns of granule cells in the fascia dentata (FD), an area ‘upstream’ from CA3, are also reactivated during sleep. Populations of FD granule cells were recorded from during spatial behavior and during prior and subsequent SWS. Firing rate correlations between cell‐pairs with overlapping place fields were significantly enhanced during post behavioral sleep compared to pre behavioral sleep. Correlations between cells with non‐overlapping place fields or which were silent during maze behavior, were not changed. Thus, reactivation of experience‐specific correlation states also occurs in granule cells during sleep. Because these cells do not have excitatory interconnections, but form a major input to CA3 pyramidal cells, current models predicted that sleep reactivation would appear first in CA3. There are, however, both extensive polysynaptic excitatory interactions among granule cells and feedback from CA3 pyramidal cells. Granule cells also receive indirect input from neocortical regions known to undergo trace reactivation. Although a simple model for a CA3 origin of the reactivation phenomenon cannot be confirmed, the present results extend our understanding of the generality of this phenomenon.
Memory consolidation during sleep: a neurophysiological perspective
Authors: BuzsÁk GyÖrgy
Published: November 2003

In the awake brain, information about the external world reaches the hippocampus via the entorhinal cortex, whereas during sleep the direction of information flow is reversed: population bursts initiated in the hippocampus invade the neocortex. We suggest that neocortico‐hippocampal transfer of information and the modification process in neocortical circuitries by the hippocampal output take place in a temporally discontinuous manner associated with the wake‐sleep cycle. Loading the hippocampus with neocortical information may happen fast during the aroused state of the hippocampus associated with theta/gamma oscillations. On the other hand, transfer of the stored representations to neocortical areas is carried by discrete quanta of co‐operative neuronal bursts (called sharp wave bursts) initiated in the hippocampus during slow wave sleep. The spatio‐temporal participation of principal cells in sharp waves is determined by experience‐induced changes in the CA3 recurrent collateral matrix. The co‐operative, converging pre‐synaptic activity can induce localized fast spikes and associated calcium influx in the apical dendrites of CA1 pyramidal cells, a necessary condition for the induction of synaptic plasticity. In addition, the subcortical effects of hippocampal sharp wave bursts may be critical in the release of various hormones which, in turn, may affect synaptic plasticity. These observations suggest that sleep patterns in the limbic system are essential for the preservation of experience‐induced synaptic modifications.
Temporal evolution of coherence and power in the human sleep electroencephalogram
Authors: Achermann Peter , BorbÉly Alexander
Published: November 2003

Coherence analysis of the human sleep electroencephalogram (EEG) was used to investigate relations between brain regions. In all‐night EEG recordings from eight young subjects, the temporal evolution of power and coherence spectra within and between cerebral hemispheres was investigated from bipolar derivations along the antero‐posterior axis. Distinct peaks in the power and coherence spectra were present in NREM sleep but not in REM sleep. They were situated in the frequency range of sleep spindles (13–14 Hz), alpha band (9–10 Hz) and low delta band (1–2 Hz). Whereas the peaks coincided in the power and coherence spectra, a dissociation of their temporal evolution was observed. In the low delta band, only power but not coherence showed a decline across successive NREM sleep episodes. Moreover, power increased gradually in the first part of a NREM sleep episode, whereas coherence showed a rapid rise. The results indicate that the intrahemispheric and interhemispheric coherence of EEG activity attains readily a high level in NREM sleep and is largely independent of the signal amplitude.
Functional brain imaging of human sleep
Authors: MAQUET PIERRE , PHILLIPS CHRISTOPHE
Published: November 2003

This paper presents an overview of the contribution of functional brain mapping to the study of human sleep. Early studies were essentially successful in describing the variations of the global level of cerebral metabolism. More recently, regional distribution of cerebral blood flow was reported. The results suggest that the permissive and executive processes of slow wave sleep and REM sleep are similar in humans and in animals. They also show cortical blood flow distributions specific to each sleep stage. The cellular mechanisms underlying the involvement of these cortical areas in sleep are not yet precisely known. They should be looked for by further investigations in animals. Future research in functional neuroimaging will attempt to explore functional and, hopefully, effective connectivity between cerebral areas involved in sleep processes. This final goal will probably require the co‐registration of two or more brain imaging techniques to precisely describe the spatio‐temporal course of neuronal interactions occurring during sleep.
A new method for detecting state changes in the EEG: exploratory application to sleep data
Authors: McKeown Martin , Humphries Colin , Achermann Peter , Borbély Alexander , Sejnowsk Terrence
Published: November 2003

A new statistical method is described for detecting state changes in the electroencephalogram (EEG), based on the ongoing relationships between electrode voltages at different scalp locations. An EEG sleep recording from one NREM‐REM sleep cycle from a healthy subject was used for exploratory analysis. A dimensionless function defined at discrete times ti, u(ti), was calculated by determining the log‐likelihood of observing all scalp electrode voltages under the assumption that the data can be modeled by linear combinations of stationary relationships between derivations. The u(ti), calculated by using independent component analysis, provided a sensitive, but non‐specific measure of changes in the global pattern of the EEG. In stage 2, abrupt increases in u(ti) corresponded to sleep spindles. In stages 3 and 4, low frequency (≈ 0.6 Hz) oscillations occurred in u(ti) which may correspond to slow oscillations described in cellular recordings and the EEG of sleeping cats. In stage 4 sleep, additional irregular very low frequency (≈ 0.05–0.2 Hz) oscillations were observed in u(ti) consistent with possible cyclic changes in cerebral blood flow or changes of vigilance and muscle tone. These preliminary results suggest that the new method can detect subtle changes in the overall pattern of the EEG without the necessity of making tenuous assumptions about stationarity.
Interspecies comparisons of plasma half‐life of trimethoprim in relation to body mass
Authors: PASHOV D.A. , LASHEV L.D. , MATEV I.B. , KANELOV I.N.
Published: November 2003

The relationship between body mass and plasma half‐life of trimethoprim was studied in 10 different species of animals and man using published data. Log half‐life was positively and significantly correlated to log body mass based on individual measurements in herbivorous animals (n=23, P<0.01), in herbivorous animals+pigs (n=29, P<0.01), in ungulates (n=27, P<0.01), in ruminants (n=16, P<0.01) and in non‐herbivorous mammals, except pigs (n=6, P<0.05). The correlation was described by the allometric equations: t½β=27 W0.26 in herbivorous animals and t½β=125 W0.32 in non‐herbivorous animals except pigs.
Changes in taurine levels in response to repeated administration of the β2‐agonist salbutamol in lambs
Authors: BASTOS M.L. , CARVALHO F. , REMIÃO F. , MENDES M.E. , FERREIRA M.A. , SOARES M.E. , TIMBRELL J.A.
Published: November 2003

Repeated oral administration of salbutamol to lambs for 28 days was found to decrease levels of taurine significantly in the serum and heart, and the mean excretion of taurine into urine was significantly less than in controls. Serum urea, low density lipoprotein and high density lipoprotein were also significantly reduced. Consistent with these changes, fat content in muscle was reduced, whereas protein content was not significantly changed. Body weight was not significantly changed by salbutamol treatment but heart and kidney weights (relative to body weight) were significantly increased. Salbutamol excretion in urine was relatively constant and residues were detected in certain organs and tissues, notably liver, bile and kidney. Changes in urinary and serum taurine level may reflect subtle changes in protein metabolism not detectable as changes in body weight or gross protein content.
Veterinary drug bioequivalence determination
Authors: TOUTAIN P.‐L. , KORITZ G. D.
Published: November 2003

A bioequivalence trial is a statistically based comparison of two formulations to demonstrate with a controlled consumer (patient) risk that two formulated drug products are interchangeable. The basic assumption underlying a bioequivalence trial is that essentially the same plasma time‐course leads to essentially the same effect allowing two formulations to be interchanged. Bioequivalence is generally assessed using kinetic end points and in practice, two formulations in which bioavailability parameters (rate and extent) differ by 20% or less, with a 90% degree of confidence, are considered to be bioequivalent. In this review, the design and evaluation of bioequivalence studies are presented with special attention given to scientific issues.
A comparison of preoperative morphine and buprenorphine for postoperative analgesia for arthrotomy in dogs
Authors: Brodbelt D.C. , Taylor P.M. , Stanway G.W.
Published: November 2003

The aim of this study was to compare morphine with the partial agonist, buprenorphine, for postoperative analgesic effects, when administered preoperatively for elective arthrotomy in dogs. Fifty two dogs were anaesthetized for stifle, elbow, or hock arthrotomy. The dogs were premedicated 30 min prior to induction of anaesthesia with 0.03 mg/kg acepromazine intramuscularly, and either 0.3 mg/kg morphine or 0.01 mg/kg buprenorphine intramuscularly (allocated randomly). Anaesthesia was induced with thiopentone and maintained with halothane in an oxygen/nitrous oxide mixture. Pain and sedation were assessed preoperatively, and 0.5, 1, 2, 3, 5, and 7 h after the halothane was switched off, with a visual analogue scale scoring system. Pain scores did not differ significantly (morphine group median postoperative score from 30 to 40 mm, buprenophine group median postoperative score from 36 to 43 mm) and analgesia was considered adequate in the majority of cases (score less than 40 mm). Morphine produced significantly more sedation at 0.5 h after anaesthesia only. It was concluded that both opioids are equally suitable analgesics for postoperative analgesia for the elective arthrotomy in dogs.
Pharmacokinetics of oxolinic acid in sea‐bass, Dicentrarchus labrax (L., 1758), after a single rapid intravascular injection
Authors: POHER I. , BLANC G. , LOUSSOUARN S.
Published: November 2003

The pharmacokinetics of oxolinic acid was studied in sea‐bass (Dicentrarchus labrax). The fish were kept in seawater at 15.2°C with a 12 h/12 h photoperiod. Oxolinic acid was injected in the caudal vein of anaesthetized sea‐bass in a single rapid intravascular administration at a dose of 10 mg/kg of body weight. Plasma concentrations of oxolinic acid were determined using two analytical methods, a classic plate diffusion bioassay using Escherichia coli and a high performance liquid chromatography (HPLC) using solid phase extraction with an internal standard and a U.V. detection. The mean recoveries were 99.6% and 110.8% and determination limits were 0.04 μg/mL and 0.02 μg/mL, for the bioassay and the HPLC respectively. Compared to other fish species, the oxolinic acid was rapidly (absorption half life, ta1/2= 0.69 h) distributed to body tissues outside the blood volume (volume of central compartment, Vc= 0.4 L/kg) and presented a large volume of distribution (Vdss= 2.55 L/kg). Considering its disappearance from the central compartment (rate constant: central‐eliminated, k10= 0.16 h–1) and its total body clearance (Clt= 0.066 L/kg.h), the elimination phase of the oxolinic acid in sea‐bass was shorter than in trout kept in freshwater, and longer than in salmon in seawater. Consequently, the area under the concentration–time curve (AUC= 157 μg.h/mL) and the mean residence time (MRT= 42 h) were relatively low and short, respectively.
Pharmacokinetics of penicillin‐G in ewes and cows in late pregnancy and in early lactation
Authors: Bengtsson B. , Jacobsson S‐o. , Luthman J. , Franklin A.
Published: November 2003

Concentrations of penicillin‐G in serum were determined after single intravenous doses of potassium penicillin‐G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin‐G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model‐independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.

Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination‐half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.

It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin‐G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.
The effects of medetomidine and xylazine on gastrointestinal motility and gastrin release in the dog
Authors: NAKAMURA K. , HARA S. , TOMIZAWA N.
Published: November 2003

The effect of medetomidine, a potent and highly selective α2‐adrenoceptor agonist, on the motility of the gastric antrum, duodenum, mid‐jejunum and ileum was investigated in ten dogs. Its effect on the release of gastrin was also determined. Administration of medetomidine intramuscularly (i.m.) at a dose of 40 μg/kg inhibited the motility of the gastric antrum, duodenum, mid‐jejunum and ileum significantly, in comparison to administration of xylazine intramuscularly at a dose of 2.0 mg/kg. The release of gastrin was also significantly decreased in dogs receiving medetomidine. It was found to inhibit the motility in the gastric antrum and duodenum longer than in the mid‐jejunum and ileum, presumably by acting specifically on α2‐adrenoceptors, likely at the peripheral level. Medetomidine also inhibited the gastric contraction associated with gastrin secretion.
Pharmacokinetics of an injectable sustained‐release formulation of morphine for use in dogs
Authors: Tasker R.A.R. , Ross S.J. , Dohoo S.E. , Elson C.M.
Published: November 2003

This study investigated the pharmacokinetics of morphine sulphate in an injectable chitosan‐based gel. Gels were made from a combination of N‐O‐carboxymethylchitosan (NOCC) and chitosan and were easily injectable via a 22 gauge needle and appeared stable during long‐term storage. Groups of six beagles were injected subcutaneously (s.c.) with 1.2 mg/kg morphine sulphate, either in sterile saline or in sterilized gels, and serial blood samples were withdrawn via a jugular catheter and later analysed for morphine concentrations using radioimmunoassay. Data were analysed according to non‐compartmental pharmacokinetics. NOCC‐based gels resulted in significantly lower serum morphine concentrations at 10 and 30 min following injection but significantly higher concentrations at all points from 120 to 480 min post‐injection. Dogs receiving morphine gel exhibited equivalent or lesser variability in serum morphine concentrations than dogs receiving conventional morphine sulphate. Pharmacokinetic analysis revealed that morphine release from the gel matrix was significantly prolonged but fully bioavailable. There were no significant differences in either distribution (Vd) or terminal elimination (t1/2). Dogs experienced no adverse effects other than those normally associated with morphine administration at the time of injection but all dogs receiving the gel presented with an undefined stiffness the next day that resolved spontaneously within 48 h. We conclude that carboxymethylchitosan‐based gels hold considerable promise for the development of injectable sustained‐release formulations of opioid analgesics.