bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of different luting procedures on the seating of ceramic inlays
Authors: Hahn P. , Schaller H.‐G. , Hafner P. , Hellwig E.
Published: March 2003

This in vitro study evaluated the effect of different luting procedures on the proper seating of ceramic inlays and on the marginal seal through microleakage testing. Sixty mesial‐, occlusal‐, distal‐ (MOD) cavities were prepared in third molars, and distributed among four groups. In the control group 1, the cavity surface was treated with dentin and enamel bonding agents; ceramic inlays were placed into the cavity and light cured. In group 2, the dentin and enamel bonding agents were cured prior to the placing of the inlays, and following the insertion. In group 3, the inlays were luted without enamel bonding. In group 4, the inlays were cemented using a one‐bottle bonding and two times light curing. The groups with only one time light curing at the end of the luting process exhibited the smallest luting space following cementation. The smallest dye penetration values were obtained for the two groups with separate light curing of the dentin bonding agent. Reducing the film thickness of polymerized dentin bonding agents, i.e. by changing the composition of the bonding agents, could facilitate proper seating of ceramic inlays together with a better marginal seal.
The bond of two adhesive resins to alumina blasted and heat‐treated gold alloy surfaces
Authors: Ogunyinka A.
Published: March 2003

The purpose of this study was to test in shear mode the bond strengths of two BIS‐GMA resin cements bonded to alumina blasted and heat‐treated gold alloy surfaces. This was carried out in order to investigate the manufacturer's claim of the superiority of Panavia 21 over Panavia Ex. Alumina blasted gold alloy surfaces were cemented in pairs with either Panavia Ex or Panavia 21 resin cements. Heat‐treated gold alloy surfaces were similarly paired. The luted pairs were stored in water at 37 °C for 48 h before bond was tested with shearing forces. Although the differences were not statistically significant, it was found that Panavia 21 formed stronger bonds on the alumina blasted surfaces than Panavia Ex. However, Panavia Ex exhibited higher mean strength values than Panavia 21 on the heat‐treated surfaces. Not only was this difference statistically significant, but the bond strength values obtained for Panavia Ex on this surface were the highest in the data set. On the basis of bond testing in shear, it would appear that Panavia 21 is inferior to Panavia Ex on heat‐treated gold alloy surfaces.
Sectional prosthesis with hollow obturator portion made of thin silicone layer over resin frame
Authors: Kanazawa T. , Yoshida H. , Furuya Y. , Shimodaira K.
Published: March 2003

Magnetically retained sectional obturator prostheses, consisting of a hollow obturator portion made of thin silicone layer over a resin frame and a denture portion, were fabricated to alleviate some of the limitations of silicone materials, and applied to two edentulous patients with maxillectomy defects. The silicone obturator allowed profound engagement of undercuts within the defect, resulting in adequate retention, support and stability of the prostheses for over 3 years. The patients have achieved improvement in speech and mastication without complications, by use of the obturator prostheses.
Oral functional characteristics and gastrointestinal pathology: an epidemiological approach
Authors: Tosello A. , Foti B. , SÉdarat C. , Brodeur J. M. , Ferrigno J. M. , Tavitian P. , Susini G. , Bonfil J. J.
Published: March 2003

One of the main problems for aged people is that of having a balanced diet, improved by correct conditioning of the alimentary bolus. Does the masticatory status influence the appearance of gastrointestinal disorders? Such a question justifies the present study. The present work concerned all the patients (211) of eight geriatric institutions, and was completed by a retrospective approach (case–control study). The main result brought by the case–control study, showed that poor oral functional characteristics represent a risk for gastrointestinal pathology (age being neutralized; odds ratio (OR): 2.62). This result indicates that the loss of teeth must be compensated by functionally effective dentures. Not only will the patients’ physical and psychic health improve but also medical and public health problems will be solved.
Fracture strength of copy‐milled and conventional In‐Ceram crowns
Authors: Hwang Jung‐Won , Yang Jae‐Ho
Published: March 2003

The purpose of this study was to compare the fracture resistance of copy‐milled and conventional In‐Ceram crowns. Four groups of 10 uniform sized all‐ceramic anterior crowns were fabricated for this test: (1) In‐Ceram Spinell (2) In‐Ceram Alumina (3) Celay In‐Ceram Spinell, and (4) Celay In‐Ceram Alumina crowns. All specimens were cemented on stainless steel master die with resin cement and stored in 37 °C water for one day prior to loading into a universal testing machine. Using a steel ball at a crosshead speed of 0·5 mm min−1, the crowns were loaded at 30 °C angle until catastrophic failure occurred. Mean fracture strength was analysed and compared. Under the conditions of this study and the materials used, the following conclusions were drawn: 1. The strength of Celay In‐Ceram anterior crowns had a slightly higher fracture strength than conventional In‐Ceram crowns. 2. In‐Ceram Alumina crowns had a significantly higher fracture strength than In‐Ceram Spinell crowns in both conventional and copy milling methods.
Pressure–pain threshold determination in the oral mucosa: validity and reliability
Authors: Ogimoto T. , Ogawa T. , Sumiyoshi K. , Matsuka Y. , Koyano K.
Published: March 2003

Fundamental knowledge of pain in the oral mucosa is lacking. We determined the validity and reliability of the pressure–pain threshold (PPT) measurement in the oral mucosa using a newly developed hand‐held pressure algometer. Ten dentulous subjects were recruited, and the PPT was measured at the bilateral buccal (on the attached gingiva apical to the midline of the upper first premolars, 3 mm from the mucogingival junction) and the palatal sites (mid‐point between the bilateral upper first molars). The PPT linearly increased with an increase in load‐rate (P < 0·0001). The PPT yielded a high intra‐individual stability both for the same‐day consecutive trials and weekly sessions. The palatal site revealed a 4‐ to 4·65‐fold greater PPT than the buccal sites (Bonferroni, P < 0·0001), whereas no difference was found between the bilateral buccal sites (P=0·663). Despite a great interindividual variation in the PPT, significant intra‐individual correlations were found among the measurement sites. This suggested differences in individual sensitivity to pain in the oral mucosa, which may determine overall pain sensation specific to an individual. A pressure algometer described herein reliably assessed the PPT in the oral mucosa and sensitively discriminated PPT differences at different sites and at different load‐rates, suggest‐ing the reliability and validity of PPT measure‐ments in the oral mucosa for clinical and research investigations.
The interaction of glass–ionomer cements containing vinylphosphonic acid with water and aqueous lactic acid
Authors: Nicholson J. W. , Czarnecka B. , Limanowska‐Shaw H.
Published: March 2003

summary  A glass–ionomer cement containing an acrylic acid/vinyl phosphonic acid copolymer, has been investigated for its interaction with water and with aqueous lactic acid and the results compared with those from conventional glass–ionomers based on polyacrylic acid. Cylindrical specimens (12 mm high × 6 mm diameter) were placed in 8 cm3 of aqueous lactic acid (20 mmol dm⊟3; pH 2·7) for 1 week, at the end of which the pH was determined. Each specimen was then placed in a fresh 8 cm3 volume of lactic acid and the pH determined after a further week. This procedure was continued for a total of 13 weeks for each specimen. Experiments were also carried out on similar specimens exposed to 8 cm3 of water for 1 week only. Further experiments were carried out in which discs of cement were exposed to thin films (0·15 mm) of lactic acid at pH 4·5, with pH values determined at 30 s, 1, 2, 5 and 10 min. After 1 week, cements had changed the pH of the lactic acid to a mean value of 3·63 (SD 0·08) while in weeks 2–13 they changed it to a mean value of 3·31 (SD 0·11). After 1 week in aqueous lactic acid the cements had gained mass by a mean of 1·26% (SD 0·59%) compared with 1·22% (SD 0·14%) in water. After 13 weeks in lactic acid, cements had lost a mean of 2·83% (SD 0·74%) in mass. Thin films of aqueous lactic acid changed from pH 4·5–5·1 at 30 s and to a steady value of 5·6 (SD 0·3) between 2 and 10 min. These results were similar to those for conventional glass–ionomer cements based on carboxylic acid polymers. Hence, it was concluded that the presence of the vinylphosphonic acid units made no significant difference to the interaction of cements with aqueous solutions.
Time‐series analyses of mandibular and perioral soft tissue movements during mastication
Authors: Sakaguchi K. , Kawasaki T. , Araki O.
Published: March 2003

summary  Masticatory movements are rhythmically repeated and coordinated movements of the jaw, tongue and facial muscles. Thus, we considered that the elucidation of movements that are specific to perioral soft tissue, as a result of perioral facial muscle activities, should be useful for evaluation of the smoothness of masticatory movements. The aim of this study was to evaluate the smoothness of masticatory movements from the component of movements that are specific to perioral soft tissue during mastication by the application of time‐series analysis. The subjects were 15 healthy persons with complete natural dentition. The experimental food used for mastication in this study was sufficiently softened chewing gum. The results showed that the component of movements that are specific to perioral soft tissue during mastication are the equal repetition spatially and stable movements temporally, and that these movements have the same accurate rhythm as that of mandibular movements and cooperate with mandibular movements temporally. Moreover, the results suggested, from the viewpoint of kinematics, that the innervation of the central pattern generator was concerned with the neural basis of rhythm generation of perioral facial muscles. Therefore, the component of movements that are specific to perioral soft tissue during mastication is useful for evaluation of the smoothness of masticatory movements.
Finding time for patients: an exploration of nurses’ time allocation in an acute psychiatric setting
Authors: Whittington D. , McLaughlin C.
Published: March 2003

This article explores the proportion of work time psychiatric nurses spend in potentially psychotherapeutic one‐to‐one communication with patients. Twenty staff nurses from three acute admission wards in a psychiatric hospital in Northern Ireland were observed. The time spent in a selection of routine activities was recorded using a specially developed observation system Nurses’ Daily Activity Recording System (NURDARS). The main findings were: (i) less than half of the working day (42.7%) was spent in patient contact, and (ii) the proportion of work time which was devoted to potentially psychotherapeutic interaction with patients was very small (6.75%). The implications and limitations of the study are discussed and suggestions are made for the management and practice of psychiatric nursing, for the education of psychiatric nurses, and for further research.
Being‐With, Doing‐With: a model of the nurse–client relationship in mental health nursing
Authors: Hanson B. , Taylor M. F.
Published: March 2003

The authors describe a model of the nurse–client relationship within mental health nursing. This is preceded by a consideration of the literature in reference to the efficacy of nursing models in terms of their use within mental health nursing. A statement of philosophical beliefs is the starting point from which the model is described. The terms ‘Doing‐With’ and ‘Being‐With’ form the nucleus of the nurse–client relationship model that is founded upon the philosophy of Martin Buber. Buber explicated a philosophy of human relationships founded on his concepts of the ‘I‐Thou’ and ‘I‐It’ relationships. Two examples of the model illustrate its principles in clinical practice. The authors draw upon the work of Fawcett to argue the limitations and potential for the future development of the model described.
UK and USA Clinical Mental Health Nurse Specialists’ perceptions of their work
Authors: Nolan P. , BourKe P. , Doran M.
Published: March 2003

There is little scholarship to compare the work of mental health nurses in different countries, although this is perhaps understandable given that mental health nursing as a discrete discipline exists only in a few countries worldwide. The small‐scale study reported here sought to compare the perceptions of UK and American Clinical Nurse Specialists of various aspects of their work, including latest professional developments, current therapies and interventions, and the major problems confronting nurses today. Prior to the main study being undertaken, a short questionnaire was piloted in both countries. The main questionnaire was distributed to 34 American nurses and completed by 25 (75.5% response rate), and to 28 UK nurses and completed by 24 (86% response rate). Descriptive statistics and content analyses were used to analyse the data which suggested that where UK nurses were concerned with the range and availability of services for clients and their families, American nurses were primarily preoccupied with the quality of those services. The American sample placed greater emphasis on the provision of care that enabled clients to take responsibility for themselves than did their UK counterparts. While acknowledging the limitations of the study, the results would appear to suggest that American nurses tend to favour humanistic care, have a belief in the efficacy of chemotherapy and aim to get people functioning independently. They fear the threat to their relationship with clients that managed care might entail. Concurrently, UK nurses appear to be preoccupied with finding appropriate services for their clients and they appear to believe that the changing nature of their work is designed to accommodate structural changes in the health service, rather than to meet the needs of clients. The implications of these findings are discussed.
Teamwork in mental health: rhetoric and reality
Authors: Stark S. , Stronach I. , Warne T.
Published: March 2003

This paper offers a discussion of team‐working in mental health. It is based upon a 2‐year study funded by the English National Board for Nursing, Midwifery and Health Visiting. The authors advocate that team‐working should be studied situationally. The paper begins therefore by highlighting contextual tensions and paradoxes that create potential problems for effective team‐working. It is argued that team‐working is better caught as opposed to being taught. This involves a layered reading of vignettes and case studies, as well as ‘hands on’ experiences of team‐working. Such an approach foregrounds for inspection the complexities and dilemmas of policy, models of practice and team‐working patterns. As a result, the students build their own evidence‐base, which is not built on the ideal (or optimal) but is located in the real everyday habitus of individuals in healthcare settings. This, the authors feel, is more likely to shift terms such as team‐working, partnerships and so on, from merely remaining a healthy rhetoric.
The clinical diagnosis of the narcoleptic syndrome
Authors: PARKES J. , CHEN S. , CLIFT S. , DAHLITZ M. , DUNN G.
Published: March 2003

Sleep–wake habits and control of postural muscle tone were investigated by self‐report questionnaire in 183 subjects considered to have the narcoleptic syndrome, 62 subjects with hypersomnia and 10 with obstructive sleep apnoea. Results were compared with those in a group of 188 control subjects with normal sleep–wake habits. Excessive daytime sleepiness, determined by the Epworth Sleepiness Scale (ESS), was five times greater in the narcoleptic syndrome than in control subjects (score range 0–24, mean scores ±SD 19.6±3.0; and 4.5±3.3 respectively; P<0.001). The propensity to cataplexy, as determined by a rating scale developed to estimate the likelihood of loss of postural tone in response to sudden emotional stimuli, including laughter, was 10 times greater in narcoleptic syndrome than in control subjects (postural atonia total score range 0–600; mean±SD 334±122 and 28±45, respectively; P<0.001). Narcoleptics had more disturbances of night sleep than controls with episodes of muscle jerking, sleep walking, sleep talking and sleep terrors, as well as sleep paralysis, and higher insomnia self‐rating scores. Sleep latency from bedtime to sleep‐onset time was shorter in narcoleptics than controls. The hypersomniac group of 62 subjects was heterogeneous. Subsequent investigation showed that 18 subjects (29%) had idiopathic hypersomnia, four (6%) ‘incomplete’ narcolepsy without cataplexy and 10 (16%) hypersomnia accompanying a mood disorder. The mean ESS scores in this group and in subjects with obstructive sleep apnoea were comparable to those of the narcoleptic syndrome subject group. Mean postural atonia scores were similar to those of control subjects.
Correlations among Epworth Sleepiness Scale scores, multiple sleep latency tests and psychological symptoms
Authors: OLSON L. , COLE M. , AMBROGETTI A.
Published: March 2003

The aim of this study was to identify factors other than objective sleep tendency associated with scores on the Epworth Sleepiness Scale (ESS). There were 225 subjects, of whom 40% had obstructive sleep apnoea (OSA), 16% had simple snoring, and 4.9% had snoring with sleep disruption (upper airway resistance syndrome); 9.3% had narcolepsy and 7.5% had hypersomnolence without REM sleep abnormalities; 12% had chronic fatigue syndrome; 7.5% had periodic limb movement disorder and 3% had diurnal rhythm disorders. ESS, the results of overnight polysomnography and multiple sleep latency test (MSLT) and SCL‐90 as a measure of psychological symptoms were recorded. The ESS score and the mean sleep latency (MSL) were correlated (Spearman ??=−0.30, P<0.0001). The MSL was correlated with total sleep time (TST) and with sleep efficiency but not with apnoea/hypopnoea index. There was no association between the MSL and any aspect of SCL‐90 scores, except a borderline significant association with the somatisation subscale. The ESS was correlated with TST but not with sleep efficiency or apnoea/hypopnoea index. The ESS was correlated with all subscales of the SCL‐90 except psychoticism. An ESS≥10 had poor sensitivity and specificity as a predictor of MSL <10 min or MSL <5 min. We conclude that the MSLT and the ESS are not interchangeable. The ESS was influenced by psychological factors by which the MSL was not affected. The ESS cannot be used to demonstrate or exclude sleepiness as it is measured by MSLT.
Sino‐aortic denervation augments the increase in blood pressure seen during paradoxical sleep in the rat
Authors: SEI HIROYOSHI , MORITA YUSUKE , TSUNOOKA KIYOSHI , MORITA HIRONOBU
Published: March 2003

Using a computer assisted telemetric system, we have re‐examined the effect of sino‐aortic denervation (SAD) on the changes in arterial blood pressure (AP) and heart rate (HR) during sleep in the rat suitably recovered from the operation. Eight 1 hourly polygraphic recordings were performed 4 weeks after the initial SAD surgery. In the SAD rats, the increase in AP during paradoxical sleep (PS) was much larger than that in sham‐operated rats. HR in the SAD rats increased on‐going from slow‐wave sleep to PS, but it showed no change in sham‐operated rats. The present study suggests that chronic SAD causes the enhanced AP increase during PS concomitantly with the persistent hypertension and tachycardia across sleep‐wake states.
Cardiac autonomic function during sleep in psychogenic and organic erectile dysfunction
Authors: Lavie Peretz , Shlitner Arie , Nave Rachel
Published: March 2003

The present study investigated the sympathetic/parasympathetic balance during non‐rapid eye movement (NREM) and rapid eye movement (REM) sleep in patients with psychogenic and organic erectile dysfunction. The cardiac autonomic balance was assessed from the power of the low frequency (LF) and high frequency (HF) spectral components of heart‐rate variability in 11 patients with psychogenic erectile dysfunction and 11 patients with organic erectile dysfunction as determined by monitoring sleep‐related erections. Spectral analysis of heart‐rate variability was calculated for at least four successive 4‐min epochs of electrocardiogram recordings during NREM sleep and for all available 4‐min epochs during REM sleep. Statistical analysis revealed that organic patients had a significantly higher LF/HF ratio (P< 0.01) during both stages of sleep, which resulted from a significantly lower power in the HF component (P< 0.004) and higher power in the LF component (P< 0.01) in these patients, in both REM and NREM sleep stages. These results demonstrate that patients complaining of daytime sexual dysfunction and found by sleep‐related erection monitoring to suffer from organic erectile dysfunction, have altered cardiac autonomic balance during both stages of sleep.
Sleep/wake abnormalities in patients with periodic leg movements during sleep: Factor analysis on data from 24‐h ambulatory polygraphy
Authors: Bastuji Hélène , García‐Larrea Luis
Published: March 2003

>Periodic Leg Movements (PLM) in sleep occur in a wide variety of sleep/wake disorders but their relationship with sleep disturbance, and notably with the concomitant existence of a ‘restless legs’ syndrome (RLS) remains unclear. We performed 24‐h ambulatory polygraphy in a population of 54 consecutive, unselected patients with PLMs (Coleman's index greater than 5/h) who complained of different sleep disorders. A Principal Component Analysis (PCA) was conducted on seven variables from the sample, namely PLM index, patient's age, sleep stage changes per hour, sleep depth index (SWS+PS/TST), diurnal sleep time, number of awakenings exceeding 2 min and presence of a RLS. PCA yielded four independent factors. The PLM index and the changes of sleep stage clustered in a single factor, linking therefore sleep fragmentation to the frequency of PLMs. The second factor appeared to reflect a circadian sleep/wake disorder, combining diurnal sleep time with the number of long night awakenings. The third factor was mainly loaded by the patients’ age and the sleep depth index, thus reflecting a well known relationship. Finally, the variable reflecting the existence of a RLS appeared isolated in a single factor, independent from the three previously described. These results confirm and extend the link between PLMs and sleep fragmentation, as well as the recently described dissociation between PLMs and diurnal somnolence. On the other hand, our analysis suggests that in PLM patients the concomitant existence of a RLS is not related to the frequency of occurrence of PLMs, at least when these latter are quantified independently of their arousal index.
Effect of low and high frequency thalamic stimulation on sleep in patients with Parkinson's disease and essential tremor
Authors: Arnulf Isabelle , Bejjani Boulos‐Paul , Garma Lucile , Bonnet Anne‐Marie , Damier Philippe , Pidoux Bernard , Dormont Didier , Cornu Philippe , Derenne Jean‐Philippe , Agid Yves
Published: March 2003

Continuous high frequency stimulation of the ventral intermediate nucleus of the thalamus (Vim), delivered through surgically implanted quadripolar electrodes, alleviates tremor in Parkinson's disease (PD) and essential tremor (ET). The Vim is adjacent to the thalamic reticular nuclei, where sleep spindles originate according to animal models. In order to determine whether Vim stimulation affects sleep spindles, six patients (4 PD, 2 ET), aged 60–69 years, were recorded on a control night and a stimulation night (130 Hz, 2–3 V; right stimulation in five patients and bilateral stimulation in one patient). Stimulation did not modify sleep quality or architecture. Sleep spindles were present and symmetrical in five out of six patients under stimulation. However, in one patient with a sustained ‘thalamotomy‐like effect’ that abolished tremor, spindles were asymmetrical even without stimulation. In each patient, spindle density was similar on both nights (mean± SEM: 2.25±0.61 spindles per min of stage 2 sleep vs. 1.84±0.31). In an attempt to promote sleep two different patterns of stimulation were applied in the region of ventrooralis posterior and reticularis nuclei in five patients in the awake state. Continuous low frequency stimulation (5 Hz, 0.1 V), and repeated trains of 15 Hz for 1 s every 15 s mimicking the pattern of physiological spindles, each failed to induce sleep or cortical synchronization. We conclude that Vim stimulation, unlike thalamotomy, selectively reduces tremor without altering sleep or sleep spindles. Our results also suggest that low frequency stimulation applied in the region of the reticular nuclei does not induce sleep.
Pattern analysis of sleep‐deprived human EEG
Authors: Kim Hyungrae , Guilleminault Christian , Hong Seungchul , Kim Daijin , Kim Sooyong , Go Hyojin , Lee Sungpil
Published: March 2003

Progress during the past decade in non‐linear dynamics and instability theory has provided useful tools for understanding spatio‐temporal pattern formation. Procedures which apply principle component analysis (using the Karhunen–Loeve decomposition technique) to the multichannel electroencephalograph (EEG) time series have been developed. This technique shows localized changes of cortical functioning; it identifies increases and decreases of the activity of localized cortical regions over time while the subject performs a simple task or test. It can be used to demonstrate the change in cortical dynamics in response to a continuous challenge. Using 16 EEG electrodes, the technique provides spatio‐temporal information not obtained with power spectrum analysis, and includes the weighted information given with omega complexity. As an application, we performed a pattern analysis of sleep‐deprived human EEG data in 20 healthy young men. Electroencephalograph recordings were performed on subjects for <2 min, with eyes closed after normal sleep and after 24 h of experimentally‐induced sleep deprivation. The significant changes in the eigenvector components indicated the relative changes of local activity in the brain with progressive sleep deprivation. A sleep deprivation effect was observed, which was hemispherically correlated but with opposite directional dynamics. These changes were seen in the temporo‐parietal regions bilaterally. The application of the technique showed that the simple test task was performed with a limited unilateral hemispheric involvement at baseline, but needed a much larger cortical participation with decreased frontal activity and increased coherence and bilateral hemispheric involvement. The calculations performed demonstrated that the same weighted changes as those obtained with omega complexity were shown, but the technique had the added advantage of showing the localized directional changes of the principle eigenvector at each studied electrode, pointing out the cortical localized region affected by the sleep deprivation and toward which direction the environmental challenge induced the spatial change. This methodology may allow the evaluation of changes in local dynamics in brain activity in normal and pathological conditions.
Detecting insomnia: comparison of four self‐report measures of sleep in a young adult population
Authors: Smith Simon , Trinder John
Published: March 2003

The sensitivity and specificity of four self‐report measures of disordered sleep – the Sleep Impairment Index (SII), the Sleep Disorders Questionnaire (SDQ), the Dysfunctional Beliefs and Attitudes About Sleep Scale (DBAS) and the Sleep–Wake Activity Inventory (SWAI) – were compared in subjects with insomnia and normal sleep. Nineteen young adult subjects met DSM‐IV criteria for primary insomnia and another 19 were normal control subjects. Discriminatory characteristics of each measure were assessed using receiver operator characteristic curve analyses. Discriminatory power was maximised for each measure to produce cut‐scores applicable for identification of individuals with insomnia. The DBAS, SII and SDQ psychiatric DIMS subscale were found to correlate, and discriminated well between the two groups. The SWAI nocturnal sleep subscale was not found to be an accurate discriminator. The results suggest differences in the measures in their ability to detect insomnia, and offer guidelines as to the optimal use of test scores to identify young adults suspected of insomnia.
Heart rate variability during sleep in children with partial epilepsy
Authors: Ferri Raffaele , Curzi‐Dascalova Lilia , Arzimanoglou Alexis , Bourgeois Marie , Beaud Christine , Nunes Magda lahorgue , Elia Maurizio , Musumeci Sebastiano A. , Tripodi Mariangela
Published: March 2003

Alterations in autonomic control of cardiac activity in epileptic patients have been reported by several studies in the past, and both ictal and interictal modifications of heart rate regulation have been described. Alterations of autonomic control of cardiac activity can play an important role in sudden unexplained death in patients with epilepsy (SUDEP). However, the presence of specific changes in heart rate variability (HRV) during sleep, not correlated with seizures, has not been assessed in children with epilepsy; for this reason, we evaluated features of cardiac autonomic function during sleep without ictal epileptiform electroencephalogram (EEG) activity in a group of children with partial epilepsy. Eleven patients (five males and six females; mean age 11.5 years, SD: 3.65 years) affected by partial epilepsy were admitted to this study; 11 normal subjects (five males and six females; mean age 12.9 years, SD: 2.72 years) served as a control group. All subjects slept in the laboratory for two consecutive nights. The data were analyzed during the second night. Sleep was polygraphically recorded [including one electrocardiography (ECG) channel] and signals were digitally stored. A series of 5‐min ECG epochs were chosen from each sleep stage, during periods without evident ictal epileptiform activity in the EEG. Electrocardiography signals were analyzed for automatic detection of R‐waves and, subsequently, a series of time‐ and frequency‐domain measures were calculated. Epileptic subjects tended to show an overall lower HRV in both time‐ and frequency‐domain parameters, principally during rapid eye movement (REM) sleep and, to a lesser extent, during sleep stage 2. Among the different bands, this decrease was most evident for the high‐frequency band (HF) absolute power. For this reason, the ratio between the low‐frequency band (LF) and HF was always higher in epileptic patients than in normal controls and the difference was statistically significant during sleep stages 3 and/or 4 and REM sleep. Our results indicate that during sleep, a particular condition of basal modification in autonomic characteristics occurs (mostly during REM sleep) in partial epilepsy patients. This finding might represent an important factor contributing to the complex mechanism of SUDEP which takes place most often during sleep and supports the need of studying HRV specifically during this state in subjects with seizures.
Spatial organization of EEG activity from alertness to sleep stage 2 in old and younger subjects
Authors: TSUNO N. , SHIGETA M. , HYOKI K. , KINOSHITA T. , USHIJIMA S. , FABER P. L. , LEHMANN D.
Published: March 2003

In order to elucidate brain mechanisms that contribute to the increased tendency for vigilance dysregulation in the elderly, we examined the spatial organization of brain electric activity [electroencephalogram (EEG)] during decreasing vigilance from alertness to onset of sleep stage 2, comparing 7 old and 10 younger, healthy subjects (60–79 and 18–41 years old, respectively). Two features were analyzed: (1) change of location of the brain electric source gravity centers of the EEG frequency bands, and (2) magnitude of fluctuation of these locations over time. Multichannel EEG was analyzed into source gravity center localizations for seven EEG frequency bands, using fast Fourier transform (FFT) Dipole Approximation (first principal component‐single source modeling in the frequency domain). Multivariate analysis of covariance (MANCOVA) showed: source localizations were more anterior in old than younger subjects for beta‐1 and more superior for all three beta bands; from alertness to sleep, delta and theta EEG sources (inhibitory activity) changed to more posterior and superior areas, and alpha‐1 and ‐2 (routine activity) and beta‐1 and ‐2 sources (excitatory activity) towards anterior and superior areas. Fluctuations of the source locations of delta and beta‐2 were larger on the superior–inferior axis, and of beta‐2 smaller on the left–right axis in the old than younger subjects. The results suggest functional specifications (inhibitory, routine, excitatory) of cortical positron emission tomography (PET) changes reported in sleep. In sum, aging exhibits changes in spatial organization of EEG‐generating neuronal assemblies; during the transition wakefulness‐to‐sleep, aging affects the spatial‐temporal dynamics of this organization. The latter is suggested to contribute to the increased risk for consciousness disturbances in the elderly.
A pharmacokinetic study including some relevant clinical effects of medetomidine and atipamezole in lactating dairy cows
Authors: Ranheim  , Arnemo  , Ryeng  , Søli  , Horsberg
Published: March 2003

Medetomidine is the most potent and selective α2‐agonist used in veterinary medicine and its effects can be antagonized by the α2‐antagonist atipamezole. The pharmacokinetics of medetomidine and atipamezole were studied in a cross‐over trial in eight lactating dairy cows. The animals were injected intravenously (i.v.) with medetomidine (40 μg/kg) followed by atipamezole i.v. (200 μg/kg) or saline i.v. after 60 min. Drug concentrations in plasma were measured by HPLC. After the injection of atipamezole, the concentration of medetomidine in plasma increased slightly, the mean increment being 2.7 ng/mL and the mean duration 12.1 min. However, atipamezole did not alter the pharmacokinetics of medetomidine. It is likely that the increase in medetomidine concentration is caused by displacement of medetomidine by atipamezole in highly perfused tissues. The volume of distribution at steady state (Vss) for medetomidine followed by saline and medetomidine followed by atipamezole was 1.21 and 1.32 L/kg, respectively, whereas the total clearance (Cl) values were 24.2 and 25.8 mL/min·kg. Vss and Cl values for atipamezole were 1.77 mL/kg and 48.1 mL/min·kg, respectively. Clinically, medetomidine significantly reduced heart rate and increased rectal temperature for 45 min. Atipamezole reversed the sedative effects of medetomidine. However, all the animals, except one, relapsed into sedation at an average of 80 min after injection of the antagonist.
Bioavailability of amprolium in fasting and nonfasting chickens after intravenous and oral administration
Authors: Hamamoto  , Koike  , Machida
Published: March 2003

The bioavailability of amprolium (APL) was measured after intravenous (i.v.) and oral (p.o.) administration to chickens. Twelve healthy chickens weighing 1.28–1.41 kg received a dose of 13 mg APL/kg intravenously, and 13 or 26 mg APL/kg orally in both a fasted and a nonfasted condition in a Latin square design. Plasma samples were taken from the subwing vein for determination of APL concentration by HPLC method. The data following intravenous and oral administration were best fitted by 2‐compartment and 1‐compartment models, respectively, using weighted nonlinear least squares regression. The half‐life beta t½β, volume of distribution (Vd) and total body clearance (Cl) after intravenous administration were 0.21 h, 0.12 L/kg and 1.32 L/h.kg, respectively. The elimination half‐life (t½ Kel) after oral administration was 0.292–0.654 h which is 1.5–3.2 times longer than after intravenous administration, suggesting the presence of a ‘flip‐flop’ phenomenon in chickens. The maximum plasma concentration (Cmax) of 13 mg/kg APL administered orally to chickens during fasting was significantly (about four times) higher than that during nonfasting (P < 0.05). Bioavailability during nonfasting was from 2.3 to 2.6%, and 6.4% during fasting.
Ropivacaine in the horse: its pharmacological responses, urinary detection and mass spectral confirmation
Authors: Harkins J. D. , Karpiesiuk W. , Lehner A. , Woods W. E. , Dirikolu L. , Carter W. G. , Boyles J. , Tobin T.
Published: March 2003

This report evaluates the pharmacological responses, urinary detection and mass spectral confirmation of ropivacaine in horses. Ropivacaine, a potent local anesthetic (LA) recently introduced in human medicine, has an estimated highest no‐effect dose (HNED) of about 0.4 mg/site as determined in our abaxial sesamoid block model. Apparent ropivacaine equivalents were detectable by ELISA screening using a mepivacaine ELISA test after administration of clinically effective doses. Mass spectral examination of postadministration urine samples showed no detectable parent ropivacaine, but a compound indistinguishable from authentic 3‐hydroxyropivacaine was recovered from these samples. The study shows that ropivacaine is a potent LA in the horse, that clinically effective doses can be detected in postadministration samples by ELISA‐based screening, and that its major post administration urinary metabolite is 3‐hydroxyropivacaine.
Endothelin receptor mediating contraction of isolated bovine coronary artery
Authors: Ishiguro S. , Kawase J. , Miyamoto A. , Nishio A.
Published: March 2003

We studied endothelin (ET) receptors and their subtypes on isolated bovine coronary arteries. Endothelin receptors that mediated contraction of isolated bovine coronary artery were characterized by the use of antagonists and agonists. Contractions induced by the nonselective agonist ET‐1 (10–10–10–7 M) were not affected by the removal of the endothelium (pEC50: 8.52, maximal contraction: 105% of that induced by 60 mM KCl). BQ‐123 (3 × 10–7 M) antagonized contractions of endothelium‐denuded coronary rings induced by low concentrations of ET‐1 (10–10 or 10–9 M), but potentiated the contractions induced by higher concentrations of ET‐1 (3 × 10–8 and 10–7 M). BQ‐788 (10–6 M) potentiated contractions induced by ET‐1 (3 × 10–10 and 10–7 M). In the presence of BQ‐788 (10–6 M), BQ‐123 (3 × 10–8–3 × 10–6 M) concentration – dependently inhibited contractions induced by ET‐1 (3 × 10–10 and 10–7 M) (pA2: 6.61). Sarafotoxin S6b (10–9–3 × 10–7 M) evoked contractions in the denuded coronary artery (pEC50: 8.49, maximal contraction: 139% of 60 mM KCl). The BQ‐123 caused a concentration‐dependent rightward shift of contractions induced by sarafotoxin S6b (pA2: 7.89). The present study indicates that ET‐1 and sarafotoxin S6b contract the isolated bovine coronary artery by stimulating ETA receptors on smooth muscle cells, and that ETB receptors might suppress the ET‐1‐induced contractions.
In vitro cytochrome P450‐mediated hepatic activities for five substrates in specific pathogen free chickens
Authors: Khalil W. F. , Saitoh T. , Shimoda M. , Kokue E.
Published: March 2003

Total hepatic microsomal cytochrome P450 (CYP) content as well as in vitro CYP mediated activities for five substrates [bufuralol 1‐hydroxylation, ethoxyresorufin O‐deethylation, S‐mephenytoin 4‐hydroxylation, testosterone 6β‐hydroxylation, and tolbutamide hydroxylation] were measured in specific pathogen free male Japanese leghorn chickens and male beagle dogs. The Vmax, Km and intrinsic clearance (Vmax/Km) for these substrates were calculated and compared between animal species in order to evaluate the drug catalytic activity in chicken liver. The total CYP content in chicken (0.296 ± 0.04 nmol/mg microsomal protein) was close to levels reported for other species including humans, cats, pigs and some nonmammalian vertebrates (e.g. snakes, frogs and trout fish), but was lower than levels measured in dogs (1.11 ± 0.22) or recorded in guinea‐pigs, hamsters, monkeys, mice, rabbits, rats, horse and ruminants. Bufuralol 1‐hydroxylation, ethoxyresorufin O‐deethylation, S‐mephenytoin 4‐hydroxylation, and testosterone 6β‐hydroxylation were lower in chickens than in dogs based on intrinsic clearance. On the other hand, tolbutamide hydroxylation was markedly higher in chickens than in dogs.
Acute effects of escalating doses of amiodarone in isolated guinea pig hearts
Authors: BICER S. , PATCHELL J. S. , HAMLIN D. M. , HAMLIN R. L.
Published: March 2003

Bicer, S., Patchell, J. S., Hamlin, D. M., Hamlin, R. L. Acute effects of escalating doses of amiodarone in isolated guinea pig hearts. J. vet Pharmacol. Therap.25, 221–226.

Cardiac effects of escalating concentrations of amiodarone were determined on isolated perfused guinea pig hearts (Langendorff preparations). Spontaneously beating hearts were instrumented for the measurement of RR, PQ, QRS, QT and QTc durations (from a bipolar electrogram), and dP/dtmax and dP/dtmin from an isovolumetric left ventricular pressure curve. Ten hearts were exposed to escalating concentrations of amiodarone (10–7, 10–6, 10–5 and 10–4 M) in dimethyl sulfoxide (DMSO)/Krebs–Henseleit or to DMSO/Krebs–Henseleit (vehicle). Measurements were collected during the last minute of a 15‐min concentration. Means of all parameters were compared by ANOVA with repeated measures design. When compared with vehicle, amiodarone prolonged QT and QTc durations at concentrations >10–6 M. The apparent lengthening of RR, PQ and QRS at concentrations >10–6 M did not achieve statistical significance. Similarly, the apparent decreases in dP/dtmax and dP/dtmin at concentrations >10–6 M did not achieve statistical significance. The putative therapeutic concentration of amiodarone is between 2 and 4 × 10–6 M. In this study, at a concentration of 10–6 M, only RR and dP/dtmin tended to change, but they were not different from vehicle. Thus, amiodarone in this preparation has little potential for cardiac toxicity at therapeutic concentrations.
Leucocyte interferon‐α retreatment for chronic hepatitis C patients previously intolerant to other interferons
Authors: Cacopardo B. , Benanti F. , Brancati G. , Romano F. , Nunnari A.
Published: March 2003

The activity and tolerability of a retreatment cycle with leucocyte interferon‐α (IFN‐α) (6 million units (MU) three times weekly for 12 months) was evaluated in a group of 22 hepatitis C patients who had been intolerant to a previous course of lymphoblastoid IFN‐α. Seven patients (31%) discontinued the new therapy owing to either a lack of response (six patients) or to severe leucopenia (one patient). Fifteen patients (68%) completed the 12‐month treatment: all had a biochemical response and 10 (45%) also had disappearance of serum HCV RNA (complete response). Mild adverse reactions (fever, headaches and diarrhoea) were seen in these patients during retreatment. After 12 months of follow‐up, 11 patients (50%) still maintained the biochemical response (long‐term response); seven of these patients (32%) were also negative for serum HCV RNA. Biochemical and complete responses, at the end of both treatment and follow‐up, were similar to those seen with lymphoblastoid IFN‐α. The full dose of leucocyte IFN‐α, when used in patients previously intolerant to the same dosage of lymphoblastoid IFN‐α, was better tolerated: only one of the 15 patients who completed the 12‐month treatment had a severe adverse event leading to withdrawal vs 22 of 68 patients treated with lymphoblastoid IFN‐α. Furthermore, there were no manifestations of serological or clinical autoimmunity caused by leucocyte IFN‐α, even in patients with autoantibodies associated with previous IFN therapy.
Hepatitis B virus infection in microcarrier‐attached immortalized human hepatocytes cultured in molecularporous membrane bags: a model for long‐term episomal replication of HBV
Authors: Gong Z. J. , De Meyer S. , Roskams T. , Van Pelt J. F. , Soumillion A. , Crabbé T. , Yap S. H.
Published: March 2003

Studies on the pathobiology of chronic (long‐term) hepatitis B virus (HBV) infection and in vitro drug testing have been hampered by the lack of appropriate systems for culturing susceptible cells chronically infected with HBV. Most of the in vitro studies of HBV replication have been performed with HBV genome‐transduced cell lines. In this system, viral production is mainly the result of chromosomal replication. In an invitro infection system, owing to medium refreshment (which leads to the removal of infectious particles necessary for the perpetuation of infection) and to trypsinization for cell passages, it is difficult, if not impossible, to maintain chronic HBV infection, despite the use of susceptible cells. To circumvent these unfavourable factors for chronic HBV infection in vitro, we cultured microcarrier‐attached immortalized human hepatocytes, infected with HBV, in molecularporous (MW 12000–14000) membrane (dialysis) bags for a duration of 2 months. HBV covalently‐closed‐circular (ccc) DNA, HBV precore/core and X mRNAs were detected in the cells cultured in this system following infection until the end of the experiment (day 58), while in classical culture conditions (monolayer), markers of HBV replication were also detected. Production of hepatitis B surface antigen (HBsAg) and HBV DNA was detected and their levels in culture medium (collected at the end of experiments from the molecularporous membrane bags) were increased 2.86‐ and 3.28‐fold respectively. Using Southern blot analysis, HBV replicative intermediates could also be demonstrated throughout the experiments. However, integrated HBV DNA was not present. In contrast, HBV ccc DNA, HBV precore/core and X mRNAs, and replicative intermediates were not demonstrable in FTO 2B rat hepatoma cells infected in the same manner in parallel experiments. This in vitro infection system, using susceptible, immortalized human hepatocytes, therefore provides a new tool for studying the long‐term effect of HBV infection, mainly involving episomal replication in hepatocytes, and for drug testing.