bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the Active Membrane Properties of Rat Supraoptic Neurones During Pregnancy and Lactation
Authors: Teruyama R. , Armstrong W. E. 
Published: March 2003

AbstractTo better understand the plasticity of intrinsic membrane properties of supraoptic magnocellular neuroendocrine cells associated with reproductive function, intracellular recordings were performed in oxytocin (OT) and vasopressin (VP) neurones from virgin, late pregnant (E19–22), and lactating (8–12 days of lactation) rats in vitro, using hypothalamic explants. OT neurones from virgin rats displayed a narrower spike width than neurones from pregnant and lactating rats, characterized by faster rise and decay times. Spike width changes in VP neurones were not as prominent as those observed in OT neurones. In OT neurones, the amplitude and the decay of the afterhyperpolarization following spike trains was significantly larger and faster, respectively, in pregnant and lactating rats compared to virgin rats. These properties did not change during pregnancy and lactation in VP neurones. The incidence of the depolarizing afterpotential following spikes significantly increased from approximately 20% in virgin rats to 40–50% during pregnancy and lactation in OT neurones, but was stable (80–90%) across states in VP neurones. Repetitive firing properties (frequency adaptation, the first interspike interval frequency and frequency‐current (F–I) relationship) were altered during pregnancy and lactation in OT neurones, but not VP neurones. The increased incidence of depolarizing afterpotentials in OT neurones enhances excitability, while the increased afterhyperpolarization results in suppression of firing rate. Thus, the changes may favour the short bursting activity seen in OT neurones during lactation. These results confirmed reproductive state‐dependent changes in intrinsic membrane properties of OT neurones during lactation, and suggest these changes are in place during late pregnancy. This argues that the plasticity in the electrical properties in OT neurones associated with lactation is not instigated by suckling.
Changes in the Arginine‐Vasopressin Immunoreactive Systems in Male Mice Lacking a Functional Aromatase Gene
Authors: Plumari L. , Viglietti‐Panzica C. , Allieri F. , Honda S. , Harada N. , Absil P. , Balthazart J. , Panzica G. C. 
Published: March 2003

AbstractIn male rodents, the arginine‐vasopressin‐immunoreactive (AVP‐ir) neurones of the bed nucleus of the stria terminalis (BNST) and medial amygdala are controlled by plasma testosterone levels (decreased after castration and restored by exogenous testosterone). AVP transcription in these nuclei is increased in adulthood by a synergistic action of the androgenic and oestrogenic metabolites of testosterone and, accordingly, androgen and oestrogen receptors are present in both BNST and medial amygdala. We used knockout mice lacking a functional aromatase enzyme (ArKO) to investigate the effects of a chronic depletion of oestrogens on the sexually dimorphic AVP system. Wild‐type (WT) and ArKO male mice were perfused 48 h after an i.c.v. colchicine injection and brain sections were then processed for AVP immunocytochemistry. A prominent decrease (but not a complete suppression) of AVP‐ir structures was observed in the BNST and medial amygdala of ArKO mice by comparison with the WT. Similarly, AVP‐ir fibres were reduced in the lateral septum of ArKO mice and but not in the medial preoptic area, a region where the AVP system is not sexually dimorphic in rats. No change was detected in the supraoptic and suprachiasmatic nuclei. However, a decrease in AVP‐ir cell numbers was however, detected in one subregion of the paraventricular nucleus. These data support the hypothesis that the steroid‐sensitive sexually dimorphic AVP system of the mouse forebrain is mainly under the control of aromatized metabolites of testosterone.
The effect of light premature occlusal contact on tooth pain threshold in humans
Authors: Ikeda  , Nakano  , Bando  , Suzuki  
Published: March 2003

SUMMARYThe purpose of this study was to assess the influence of an experimentally induced light premature occlusal contact on tooth sensation. This assessment involved monitoring the electric tooth pain threshold (TPT) at multiple times before and after altering the occlusal contact. This alteration was produced by placing high inlays, which were measured with a custom made measuring device in maximum intercuspation. Data were collected on 10 teeth in 5 subjects, all whom were male and between the ages of 24 and 30 years. The contact area of the high inlays varied from 75 μm to 193 μm. The TPT changes in these teeth ranged from –43 to +21% of their baseline level. Seven of these teeth showed a significant decrease (P < 0.05) in the TPT, one showed an increase and two did not show a significant change. Two of the teeth with a decreased TPT had cold water triggered occlusal pain, and 2 teeth had only occlusal pain. After several inlay adjustments to eliminate interferance in maximum intercuspation, all tested teeth returned to their TPT baseline level and all symptoms disappeared. These results suggested that a light premature occlusal contact may change tooth sensation.
Sleep, age, and shiftwork experience
Authors: Marquié J. C. , Foret J. 
Published: March 2003

SummaryThe effects of age and shiftwork experience (never, past, present) on sleep were studied in a sample of 3236 wage earners and retired workers by means of a questionnaire. The sample was composed of 32‐, 42‐, 52‐, and 62‐year‐old subjects, and included both sexes and various occupational statuses. Age resulted in a continuously increasing frequency of sleep disturbances and hypnotic use, except for difficulty getting back to sleep and early awakening, which peaked at 52 years and then decreased at 62 years, thus suggesting a ‘retirement effect’. Current and past shiftworkers reported more problems with falling asleep and early awakening than subjects who had never worked on shifts. This is a likely explanation of why the effect of age was massive in the latter group and much less pronounced in the former groups. There were no clear effects of the length or recency of shiftwork experience. This finding does not support the hypothesized permanent effect of shiftwork experience on subsequent sleep. Females had higher complaint rates at every age. There was little interaction between age and sex, but women were affected more by shiftwork as they got older, particularly as to hypnotic consumption. Some of the results support the hypothesis that a selection process excludes workers who are no longer able to cope with the demands of shiftwork.
Sleep and daytime sleepiness in retinitis pigmentosa patients
Authors: Ionescu Doina , Driver Helen S. , Heon Elise , Flanagan John , Shapiro Colin M. 
Published: March 2003

Objective We examined sleep, daytime sleepiness and the ability to stay awake during the day in patients affected with retinitis pigmentosa (RP), to further delineate the role of photoreceptors in the circadian cycle. Methods Twelve individuals diagnosed with RP (40 ± 8 years) And 12 normally sighted healthy individuals (39 ± 7 years) matched for age, body mass index (BMI) and sex were selected for the study. Participants had their sleep recorded on two consecutive nights and were monitored on the two following days. On the first day, their ability to stay awake and on the second, their sleep propensity were assessed using the Maintenance of Wakefulness Test (MWT) and the Multiple Sleep Latency Test (MSLT), respectively. Self‐report measures were obtained using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Toronto Hospital Alertness Test (THAT). Results Subjective daytime sleepiness (ESS: 9 ± 5 vs. 6 ± 4, P=0.053) and objectively measured sleep propensity (MSLT: 10 ± 5 vs. 17 ± 3 min, P < 0.000) were significantly higher in RP patients than controls, whilst their alertness (THAT: 29 ± 9 vs. 38 ± 7, P=0.016) and ability to stay awake (MWT: 21 ± 9 vs. 29 ± 2 min, P=0.006) were significantly reduced. Retinitis pigmentosa participants had more disturbed nighttime sleep, with significantly more awakenings (arousal index: 14 ± 8 vs. 8 ± 6 h, P=0.039), and tended to have less rapid eye movement (REM) sleep (19 ± 5 vs. 22 ± 3%, P=0.094). Conclusion Patients with RP have increased daytime sleepiness, reduced alertness and more disturbed nighttime sleep of poorer quality than their normally sighted counterparts, suggesting an influence of photoreceptor degeneration on the circadian cycle.
A simple way to measure daily lifestyle regularity
Authors: Monk Timothy H. , Frank Ellen , Potts Jaime M. , Kupfer David J. 
Published: March 2003

SummaryA brief diary instrument to quantify daily lifestyle regularity (SRM‐5) is developed and compared with a much longer version of the instrument (SRM‐17) described and used previously. Three studies are described. In Study 1, SRM‐17 scores (2 weeks) were collected from a total of 293 healthy control subjects (both genders) aged between 19 and 92 years. Five items (1) Get out of bed, (2) First contact with another person, (3) Start work, housework or volunteer activities, (4) Have dinner, and (5) Go to bed were then selected from the 17 items and SRM‐5 scores calculated as if these five items were the only ones collected. Comparisons were made with SRM‐17 scores from the same subject‐weeks, looking at correlations between the two SRM measures, and the effects of age and gender on lifestyle regularity as measured by the two instruments. In Study 2 this process was repeated in a group of 27 subjects who were in remission from unipolar depression after treatment with psychotherapy and who completed SRM‐17 for at least 20 successive weeks. SRM‐5 and SRM‐17 scores were then correlated within an individual using time as the random variable, allowing an indication of how successful SRM‐5 was in tracking changes in lifestyle regularity (within an individual) over time. In Study 3 an SRM‐5 diary instrument was administered to 101 healthy control subjects (both genders, aged 20–59 years) for two successive weeks to obtain normative measures and to test for correlations with age and morningness. Measures of lifestyle regularity from SRM‐5 correlated quite well (about 0.8) with those from SRM‐17 both between subjects, and within‐subjects over time. As a detector of irregularity as defined by SRM‐17, the SRM‐5 instrument showed acceptable values of kappa (0.69), sensitivity (74%) and specificity (95%). There were, however, differences in mean level, with SRM‐5 scores being about 0.9 units [about one standard deviation (SD)] above SRM‐17 scores from the same subject‐weeks. SRM‐5 scores also deviated more from a Gaussian distribution than did SRM‐17 ones. In a study with a sample size of 101, the new SRM‐5 instrument yielded scores with a mean of 4.11 and an SD of 1.13. Correlations between lifestyle regularity and age, and between lifestyle regularity and morningness appeared similar whether 5‐item or 17‐item SRM measures were used. When a gender difference in lifestyle regularity appeared, it was detected by both SRM‐5 and SRM‐17 measures.
Daytime testing after laboratory or home‐based polysomnography: comparisons of middle‐aged insomnia sufferers and normal sleepers
Authors: Edinger Jack D. , Glenn D. Michael , Bastian Lori A. , Marsh Gail R. , Dailey Dorothy , Hope T. Victor , Young Margaret , Shaw Edmund , Meeks George 
Published: March 2003

SUMMARYMany studies have shown only modest differences between insomnia sufferers and matched, non‐complaining normal controls in regard to their levels of daytime sleepiness and diurnal performances. The current study was conducted to determine whether such daytime comparisons might be affected by the setting (home vs. sleep lab) in which study participants sleep on the nights before such testing. The study used a counter‐balanced, matched‐group design in which participants underwent three consecutive nocturnal polysomnographs (PSG) conducted either in the sleep lab or in their homes prior to undergoing daytime multiple sleep latency test (MSLT) and computer‐administered performance testing. The study participants were 35 (18 women and 17 men) middle‐aged (40–59 years) non‐complaining normal sleepers and 33 middle‐aged insomnia sufferers (17 women and 16 men) who met structured interview criteria for persistent primary insomnia. Use of a hierarchical linear statistical model showed only insomnia sufferers who underwent nocturnal home PSG were more alert on the MSLT than were normal sleepers who underwent lab PSG. However, these insomnia sufferers showed a greater propensity toward attention lapses on selected reaction time tests than did either of the two normal control groups (i.e. either those who slept in the lab or those who slept at home). The results suggest the nocturnal sleep setting (home vs. lab) may affect subsequent MSLT and performance test comparisons of insomnia sufferers and normal sleepers.
Pharmacokinetics of exogenous corticotropin in normal dogs, hospitalized dogs with non adrenal illness and adrenopathic dogs
Authors: Greco  , Behrend  , Brown  , Rosychuk  , Groman  
Published: March 2003

Corticotropin (ACTH) pharmacokinetics was assessed in 10 normal dogs receiving exogenous ACTH (0.5 U/kg, i. v.). A two‐compartment open model was most appropriate for description of exogenous ACTH pharmacokinetics. The apparent distribution and elimination rate constants (α and β) were 7.4 ± 2.7 ×10−2min−1and 5.5 ± 3.8 ×10−3min−1, respectively. Area under the concentration‐time curve (AUC) was 2.91 ± 0.78 ×104pg.min/mL, mean residence time (MRT) was 45.0 ± 12.2 min, the distribution half‐life (t½α) was 9.4 min (harmonic mean), and the elimination half‐life (t½β) was 128 min (harmonic mean). The total body clearance of ACTH (ClB) was 1.83 ± 0.46 × 104mL. min/kg and volume of distribution (Vdarea) was 30 ± 15 L/kg. Corticotropin pharmacokinetics was also assessed in 12 client owned dogs, six dogs with non adrenal illness (NAI) and six dogs with hyperadrenocorticism (HAC), receiving exogenous ACTH (0.5 U/kg, i. v.). For these patients, data was best fitted to a one‐compartment open model. In dogs with NAI, theAUCwas 6.23 ± 0.62 × 105pg·min/mL,MRTwas 38.7 ± 12 min, the apparent elimination rate constant (kel) was 0.26 ± 0.0017 min−1, elimination half‐life was 26.7 min,ClBwas 0.84 ± 0.1 × 104mL/min/kg, andVdareawas 31.9 ± 5.7 L/kg. In dogs with HAC,AUCwas 4.74 ± 0.23 × 105pg·min/mL,MRTwas 20.4 min, kelwas 0.034 ± 0.009 min−1, half‐life was 20.4 min,ClBwas 1.06 ± 6.0 × 104mL /min/kg andVdareawas 29.7 ± 6.7 L/kg. Dogs with pituitary‐dependent hyperadrenocorticism showed more rapid elimination and clearance of exogenous corticotropin than dogs with NAI.
Quantification of fibrosis progression in patients with chronic hepatitis C using a Markov model
Authors: Deuffic‐Burban S. , Poynard T. , Valleron A.‐J. 
Published: March 2003

The knowledge of fibrosis progression in chronic hepatitis C and the impact of new treatments on progression is limited by the number of available liver biopsies per patient. Moreover, liver biopsies identify a patient's stage of fibrosis at a given point in time, but cannot quantify the time spent in that stage nor the date of transition to that stage. This paper assesses the potential of Markov modelling to overcome these difficulties. The data from interferon‐treated (n=185) and untreated patients (n=102) are analysed to illustrate the power of this technique.The model accurately reproduced the distributions of patients in the different fibrosis stages at two subsequent biopsies. A quantification of the role of cofactors in the progression of the disease, and the impact of interferon treatment are given. In subjects who are 40 years old and have been infected for 10 years, the model predicted that 274 of 1000 untreated patients, but only 42 of 1000 treated patients, would progress from F0 or F1 to F3 or F4 fibrosis over the next 5 years. The model also confirms that as age and duration of infection increase, the risk of fibrosis progression increases, while the impact of treatment with interferon decreases.Hence Markov modelling is an accurate tool in the analysis of fibrosis progression in chronic hepatitis C. It will be valuable for the quantification of the effect of new treatments on fibrosis progression in hepatitis C.
Fatigue in patients with chronic hepatitis C
Authors: Poynard T. , Cacoub P. , Ratziu V. , Myers R. P. , Dezailles M. H. , Mercadier A. , Ghillani P. , Charlotte F. , Piette J. C. , Moussalli J. ,   for the multivirc group*
Published: March 2003

summary. In numerous studies of symptoms in patients with chronic hepatitis C there has been no systematic assessment of both fatigue and extrahepatic manifestations. Our objective was to assess the prevalence of fatigue in patients with hepatitis C virus (HCV) infection, and to identify associations between fatigue and clinical and biological hepatic and extrahepatic manifestations. We studied 1614 patients. Data were prospectively recorded during the first visit of patients infected with HCV and the prevalence of fatigue and its association with dermatological, rheumatological, neurological and nephrological manifestations; diabetes; arterial hypertension; auto‐antibodies, and cryoglobulinaemia were assessed. Then, using multivariate analysis, we identified demographic, biochemical, immunological, virological, and histological factors associated with the presence of fatigue.Fatigue was present in 53% of patients (95% confidence interval 51–56). In 17% of patients (95% confidence interval 15–19) fatigue was severe, impairing activity. Five other extrahepatic manifestations had a prevalence above 10% including, in decreasing order: arthralgia, paresthesia,myalgia, pruritus, and sicca syndrome. In univariate and multivariate analyses, fatigue, in comparison with the absence of fatigue, was associated with female gender, age over 50 years, cirrhosis, depression and purpura. Independent of these associations, fatigue was associated with arthralgia, myalgia, paresthesia, sicca syndrome and pruritus. The prevalence of fibromyalgia (as defined by the association of fatigue with arthralgia or myalgia) was 19% (95% confidence interval 17–21). There was no significant association between fatigue and the following characteristics: viral load or genotype, alcohol consumption, abnormal thyroid function, and type and level of cryoglobulinaemia. Hence, fatigue is the most frequent extrahepatic manifestation in patients infected with HCV. Fatigue is independently associated with female gender, age over 50 years, cirrhosis, depression and purpura.
Dietary strategies of Old World Fruit Bats (Megachiroptera, Pteropodidae): how do they obtain sufficient protein?
Authors: Courts S. E. 
Published: March 2003

AbstractThe complexity of dietary strategies evolved by megachiropterans (Pteropodidae) is gaining recognition, although there are relatively few reports of feeding habits other than frugivory, and even fewer of non‐herbivorous ones. This paper reviews the information obtained so far on how the diets of Old World fruit bats may provide them with sufficient protein, as most fruits are known to be low in this vital nutrient. There is evidence to suggest that pollen, leaves or insects may provide wild pteropodids with the extra protein that studies in captivity have shown to be necessary.
The use of trackway counts to establish an index of deer presence
Authors: Mayle B. A. , Putman R. J. , Wyllie I. 
Published: March 2003

ABSTRACTThe use of transect counts of faecal pellet groups together with counts of trackways crossing the perimeter of a woodland block were investigated as a means of establishing an index of deer presence and relative abundance. Surveys were undertaken in 38 sites in agricultural landscapes in south and east England. Correlations between trackways per 100 m and faecal pellet groups per 100 m were highly significant when all sites or sites with Roe Deer (Capreolus capreolus) as the main species present were considered. Deer densities were estimated from the faecal pellet group counts and the results used to calibrate the method. Trackway counts as described provide a quick and effective means of establishing a scalar index of deer presence.
Catastrophic events and recovery from low densities in populations of otariids: implications for risk of extinction
Authors: Gerber Leah R. , Hilborn Ray 
Published: March 2003

ABSTRACTTwo key factors in a population's risk of extinction are major population declines induced by natural or anthropogenic events (catastrophes) and whether the population's rate of growth increases or decreases at very low abundance levels. These two elements should be included in any population viability analysis (PVA), but estimates of the frequency and intensity of catastrophic events and data on the dynamics of low population densities are difficult to obtain. We examined the literature on population dynamics of otariids (fur seals and sea lions), to determine how frequently populations are subjected to major population declines, and to what extent depleted populations recover from low population size. We present frequency distributions for percentage declines for otariid life‐stages (pup, juvenile, adult female and male), and describe eight examples of events leading to a population decline of 50% or greater among otariids. We found that numerous otariid populations have been reduced to very low densities by exploitation (low enough to be thought extinct) and have recovered to levels where they are no longer at risk of extinction. This suggests that the reduction in population rate of increase at low densities in otariid populations may not be strong.