bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of sleep inertia on decision‐making performance
Authors: Bruck Dorothy , Pisani Danielle L. 
Published: March 2003

SummarySleep inertia, the performance impairment that occurs immediately after awakening, has not been studied previously in relation to decision‐making performance. Twelve subjects were monitored in the sleep laboratory for one night and twice awoken by a fire alarm (slow wave sleep, SWS and REM sleep). Decision making was measured over 10 3‐min trials using the ‘Fire Chief’ computer task under conditions of baseline, SWS and REM arousal. The most important finding was that sleep inertia reduces decision‐making performance for at least 30 min with the greatest impairments (in terms of both performance and subjective ratings) being found within 3 min after abrupt nocturnal awakening. Decision‐making performance was as little as 51% of optimum (i.e. baseline) during these first few minutes. However, after 30 min, performance may still be as much as 20% below optimum. The initial effects of sleep inertia during the first 9 min are significantly greater after SWS arousal than after REM arousal, but this difference is not sustained. Decision‐making performance after REM arousal showed more variability than after SWS arousal. Subjects reported being significantly sleepier and less clear‐headed following both SWS and REM awakenings compared with baseline and this was sustained across the full 30 min. In order to generalize this finding to real‐life situations, further research is required on the effects of continuous noise, emotional arousal and physical activity on the severity and duration of sleep inertia.
Does sleep fragmentation impact recuperation?A review and reanalysis
Authors: Wesensten Nancy Jo , Balkin Thomas J. , Belenky Gregory 
Published: March 2003

SummaryStudies have shown that next‐day performance and alertness are impaired by sleep fragmentation procedures even when total sleep time (TST) is unaffected. Based on these studies it has been hypothesized that both the duration and continuity of sleep determine its recuperative value. This review of the literature suggests that when sleep fragmentation procedures increase the relative amount of stage 1 sleep, next‐day performance and alertness are impaired. Other studies suggest that stage 1 sleep has little or no recuperative value. Total sleep time, however, is typically defined as the sum of time spent in sleep stages 1, 2, 3, 4, and REM. In the present paper it is shown that when stage 1 sleep is excluded from TST, a stronger relationship between TST and subsequent alertness and performance emerges – and the need to invoke ‘sleep continuity’ as a variable that contributes independently to recuperative sleep processes is obviated. In the same way that partial or total sleep deprivation impairs alertness and performance, it is proposed that sleep disruption also impairs alertness and performance by reducing true recuperative sleep time.
Acute finger temperature changes preceding sleep onsets over a 45‐h period
Authors: Lack Leon , Gradisar Michael 
Published: March 2003

SUMMARYA resurgence in the field of sleep initiation and thermoregulation has seen a number of investigators reporting relatively gradual increases in distal skin temperatures of the hands and feet prior to sleep onset at typical bedtimes. The present study extends upon prior knowledge by investigating whether: (1) this is a change of distal skin temperature triggered specifically by the attempt to fall asleep and (2) whether this relationship holds for various phases of the circadian rhythm whenever sleep is attempted. Fourteen healthy good sleepers participated in a modified 45‐h constant routine (CR) with multiple sleep onset latency tests (MSLT) conducted every half hour. After a brief decrease of finger temperature associated with small postural adjustments at the beginning of each sleep latency test, finger temperature showed rapid (0.8 °C min−1) increases of 1–3 °C leading up to the onset of sleep. This rapid increase of finger temperature was relatively consistent across the 45‐h CR, despite very significant circadian variation of the pre‐MSLT baseline finger temperature and homeostatic decrease of sleep latency.
Rapid tryptophan depletion reverses phenelzine‐induced suppression of REM sleep
Authors: Landolt Hans‐Peter , Kelsoe John R. , Rapaport Marc H. , Gillin J. Christian 
Published: March 2003

SUMMARYTreatment with the monoamine oxidase inhibitor phenelzine completely suppressed rapid eye movement (REM) sleep in five depressed patients. Hypothesizing that increased serotonergic neurotransmission eliminated REM sleep, we administered a tryptophan‐free amino acid drink (TFD) known to reduce plasma tryptophan and brain levels of serotonin. The TFD reversed the REM sleep suppression, while the control drink (TFD plus tryptophan) had virtually no effect on sleep. Neither TFD nor control drink affected mood, total sleep time, sleep efficiency or the all‐night electroencephalogram power spectra in non‐rapid eye movement (NREM) sleep. We report the first non‐disruptive, double‐blind method for studying human subjects overnight with and without REM sleep. It opens up a novel strategy for investigating the functions of REM sleep, and the roles of serotonin and REM sleep in the regulation of NREM sleep and mood.
Bioavailability of amoxycillin in pigs
Authors: AGERSØ  , FRIIS  
Published: March 2003

Amoxycillin was administered to pigs intravenously (i.v.), intramuscularly (i.m.) and orally (p.o.), in a cross‐over design to examine the bioavailability (F) of various drug formulations. These included: a sodium salt for reconstitution in water and administration i.v.; trihydrate salt in an oil base for intramuscular administration producing ‘conventional’ duration of plasma concentrations; a trihydrate salt in oil base giving prolonged (LA) duration, and a trihydrate powder for oral administration in solution. The concentration of amoxycillin in plasma was measured by high‐performance liquid chromatography, and its pharmacokinetic variables were assessed for the individual pigs by use of non‐compartmental methods. Following i.v. administration (8.6 mg/kg), amoxycillin was eliminated rapidly with a mean residence time (MRT) of 1.4 h. After i.m. administration of the conventional formulation (14.7 mg/kg), the plasma amoxycillin concentration peaked at 2 h at 5.1 μg/mL. The bioavailability was 0.83. Intramuscular administration (14.1 mg/kg) of the long acting formulation (i.m. LA), lead to two peaks in plasma at 1.3 and 6.6 h. The bioavailability was calculated to be 1.11. After p.o. administration to fasted pigs, peak concentration was reached after 1.9 h, and the bioavailability was 0.33. In fed pigs, the corresponding values were 3.6 h and 0.28. Data showed that treatment of respiratory tract diseases in pigs by p.o. dosing alone, may not be optimal, because of the relatively low bioavailability and the fact that infections often result in reduced feed and water consumption. A rational treatment regime for susceptible respiratory pathogens includes an initial i.m. injection, followed by p.o. dosing every 12 h. Alternatively, the long acting formulation may be administered i.m. in a dose of 15 mg/kg, which would lead to active plasma concentrations for approximately 48 h.
Single‐dose pharmacokinetics of flumequine in cod (Gadus morhua) and goldsinny wrasse (Ctenolabrus rupestris)
Authors: Hansen M. K. , Horsberg T. E. 
Published: March 2003

Knowledge of the pharmacokinetic properties of drugs to combat bacterial infections in cod (Gadus morhua) and wrasse (Ctenolabrus rupestris) is limited. One antimicrobial agent likely to be effective is flumequine. The aim of this study was to investigate the pharmacokinetic properties of flumequine in these two species.Flumequine was administered intravenously to cod (G. morhua) at a dose of 5 mg/kg bodyweight and wrasse (C. rupestris) at a dose of 10 mg/kg. Flumequine was also administered orally to both species at a dose of 10 mg/kg body weight, and as a bath treatment at a dose of 10 mg/L water for 2 h. Identical experimental designs were used otherwise. The study was performed in seawater with a salinity of 3.2% and a temperature of 8.0±0.2 °C (cod) and 14.5±0.4 °C (wrasse). Pharmacokinetic modelling of the data showed that flumequine had quite different pharmacokinetic properties in cod and wrasse. Following intravenous administration, the volumes of distribution at steady‐state (Vss) were 2.41 L/kg (cod) and 2.15 L/kg (wrasse). Total body clearances (Cl) were 0.024 L/h.kg (cod) and 0.14 L/h.kg (wrasse) and the elimination half‐lives (t1/2 λ z) were calculated to be 75 h (cod) and 31 h (wrasse). Mean residence times (MRT) were 99 h (cod) and 16 h (wrasse). Following oral administration, the t1/2 λ z were 74 h (cod) and 41 h (wrasse). Maximal plasma concentrations (tmax) were 3.5 mg/L (cod) and 1.7 mg/L (wrasse), and were observed 24 h post‐administration in cod and 1 h post‐administration in wrasse. The oral bioavailabilities (F) were calculated to be 65% (cod) and 41% (wrasse). Following bath administration, maximal plasma concentrations were 0.13 mg/L (cod) and 0.09 mg/L (wrasse), and were observed immediately after the end of the bath.
Ribavirin treatment in dialysis patients with chronic hepatitis C virus infection – a pilot study
Authors: Bruchfeld A. , Ståhle L. , Andersson J. , Schvarcz R. 
Published: March 2003

Standard treatment for chronic hepatitis C is with interferon (IFN)‐α and ribavirin for 6–12 months. In dialysis patients only interferon therapy is currently used due to the lack of knowledge concerning ribavirin dosage and side‐effects. The aim of this study was to investigate if ribavirin can be added to interferon when treating dialysis patients with hepatitis C.Five patients on haemodialysis and one patient on peritoneal dialysis with chronic hepatitis C, five with genotype 1 and one with genotype 4, were given interferon‐α2b 3 MU thrice weekly for 4 weeks, whereafter ribavirin 200–400 mg was added, for an intended total treatment period of 28 weeks. Ribavirin plasma concentrations were monitored, using HPLC.Four patients completed the treatment. One patient suffered marked side‐effects from interferon and therapy was terminated. One patient developed heart failure and died after 14 weeks of treatment but the death was not considered treatment related. Based on plasma concentrations, ribavirin doses were frequently adjusted initially. The target concentration (10–15 μmol/L) was reached with average daily doses of 170–300 mg ribavirin. Ribavirin induced anaemia was managed with high doses of erytropoietin (20 000–30 000 IU/week). Five of six patients became hepatitis C virus (HCV)‐RNA negative during treatment, but four relapsed post‐treatment; one is HCV‐RNA negative.Hence ribavirin, in combination with IFN‐α, can be used to treat dialysis patients with HCV. However, this requires reduced ribavirin doses and close monitoring of ribavirin plasma concentrations and haemoglobin. Ribavirin‐induced anaemia can be managed with high doses of erythropoeitin.
Lower expression of CD81 B‐cell receptor in lymphoproliferative diseases associated with hepatitis C virus infection
Authors: Cacoub P. , Bourlière M. , Hausfater P. , Charlotte F. , Khiri H. , Toci S. , Piette J. C. , Poynard T. , Halfon P. 
Published: March 2003

summary. Chronic hepatitis C virus (HCV) infection is frequently associated with type II mixed cryoglobulinaemia (MC), a benign lymphoproliferative disease (LPD). More recently, HCV has been implicated as a possible aetiologic factor of B‐cell non‐Hodgkin lymphoma (B‐NHL). CD81, a B‐cell surface receptor, has been proposed as a receptor for HCV binding and entry in circulating B cells. The stimulation of CD81 complex enables B cells to respond to lower concentrations of antigen and finally induces B‐cell proliferation. We studied the phenotypic expression of CD81, CD19 and CD5 on circulating B cells in HCV patients LPD‐positive or LPD‐negative. Sixty‐two patients were anti‐HCV antibody positive. Among HCV positive patients, 44 were HCV RNA positive with an histologically proven chronic active hepatitis of whom 10 had a B‐NHL, 14 an MC and 24 no extrahepatic manifestation. Eighteen patients were HCV RNA negative with evidence of resolved infection. A control group included 40 healthy subjects. Peripheral blood mononuclear cells (PBMC) were stained for surface expression of CD81, CD19 and CD5 using monoclonal antibodies, and were analyzed by flow cytometry. The percentage of PBMC expressing CD81, CD19 and CD5 receptors were compared between the groups by univariate analysis. Logistic regression model variables were then evaluated to correlate the presence of an LPD with HCV infection characteristics (i.e. age, gender, genotype, duration of infection, HCV RNA positivity, liver histological lesions), or phenotypic expression of CD81, CD19 and CD5 receptors on PBMC. HCV antibody‐positive compared with HCV‐negative subjects had a higher expression of CD19 receptor (23 ± 13 vs 13 ± 1%, P = 0.003). Among HCV RNA positive‐patients, LPD+ compared with LPD– patients had a lower expression of CD81 (58 ± 28 vs 82 ± 18%, P = 0.001) and CD5 receptor (66 ± 16 vs 74 ± 13%, P = 0.04). In multivariate analysis, the expression of CD81 receptor was a negative (OR = 0.15, 95% CI = 0.04–0.64, P = 0.01) and CD19 receptor a positive (OR = 4.81, 95% CI =1.29–17.88, P = 0.02) predictive factor for an LPD. We found two negative predictive factors for HCV RNA positivity, i.e. age (OR = 0.23, 95% CI. = 0.08–0.62, P = 0.003) and the expression of CD81 receptor (OR = 0.34, 95% CI = 0.13–0.89, P = 0.02). In patients with a chronic active HCV infection, the presence of a lymphoproliferative disease, either MC or B‐NHL, is associated with lower expression of CD81 and higher expression of CD19 receptor on peripheral B cells.
Long‐term liver histology improvement in patients with chronic hepatitis C and sustained response to interferon
Authors: Toccaceli F. , Laghi V. , Capurso L. , Koch M. , Sereno S. , Scuderi M. ,   The Italian Hepanet Group
Published: March 2003

summary.  A retrospective multicentre survey was conducted to evaluate, in patients with chronic hepatitis C, the long‐term liver histological changes induced by interferon (IFN). A total of 112 patients (mean age 46.4 years) were studied. All patients had received a 6–12‐month IFN‐α course (6–18 MU/week) and had successively undergone clinical, biochemical and virological follow‐up for at least 36 months (range: 36–76). In each patient, two liver biopsies had been performed: 1–6 months before treatment and, 12–76 months after its completion. In 87 patients with biochemical and virological sustained response persisting for 12 months after therapy, post‐treatment liver necroinflammation and fibrosis mean(±SD) scores (Knodell index) were significantly lower than pretreatment scores (2.9 ± 2.2 vs 6.8 ± 2.9 and 0.8 ± 1.0 vs 1.2 ± 1.1, respectively; P < 0.01) . In 25 patients who relapsed within 1 year, necroinflammation and fibrosis post‐treatment mean scores were similar to pretreatment scores (7.4 ± 3.2 vs 6.9 ± 3.1 and 1.8 ± 1.3 vs 1.6 ± 1.2, respectively; P > 0.05). On an individual basis, necroinflammation decreased in 87% of sustained responders but only in 36% of relapsers (P < 0.001), whereas fibrosis decreased in 44% of sustained responders but only in 14% of relapsers (P < 0.001). In sustained responders with biopsies performed 12–23 months (n=34), 24–35 months (n=26) or more than 36 months (n=27) after treatment, a progressive decrease of mean necroinflammatory score was observed (−2.6 ± 2.1, −4.1 ± 3.4 and −5.2 ± 3.7 points, respectively; P < 0.01). A similar pattern was observed in fibrosis score (−0.3 ± 0.6, −0.3 ± 0.7 and −0.7 ± 0.9 points, respectively; P < 0.05). Hence, among chronic hepatitis C patients treated with IFN, those with a 12‐month sustained response, unlike those who relapse, have a long‐term progressive reduction and, in some cases, a complete regression of liver histological damage.
Is there a future for elephants in West Africa?
Authors: Barnes R. F. W. 
Published: March 2003

AbstractThe elephants of West Africa have experienced a long history of human disturbance. Before 1800 they were much affected by the precolonial empires of the savanna and Sahelian zones, the trans‐Saharan trade routes, and the coastal trade established by the Europeans. During the 19th century, the increasing demand for ivory from Europe and North America, the European penetration of the region, and the evolution of breech‐loading rifles devastated the remaining elephants. The elephant population of West Africa collapsed before the outbreak of World War I because of intense hunting for ivory. This collapse pre‐empted the decline that would have occurred anyway due to the rapid growth of the human population and consequent loss of habitat. Elephants now find themselves in about 70 small isolated populations that cover only 5% of the region. These fragments are very vulnerable – whether in the arid lands or the humid forests – to poaching and general human disturbance. There are few data on numbers; most of the population estimates are guesses. Two‐thirds of the populations are thought to consist of fewer than 200 animals and therefore have a low probability of surviving the next century.As more habitat is lost to human activities, West African elephants will soon remain only in protected areas. But many parks and reserves are managed poorly and cannot offer effective protection; they do not guarantee a future for elephants. In addition, their crop‐raiding habit makes elephants unpopular in rural communities surrounding protected areas. Human populations are expected to continue growing and resources for conservation are scarce. The future of West African elephants lies in a small network of well‐protected areas.
Permethrin‐impregnated bednet effects on resting and feeding behaviour of lymphatic filariasis vector mosquitoes in Kenya
Authors: BØGH CLAUS , PEDERSEN ERLING M. , MUKOKO DUNSTAN A. , OUMA JOHN H. 
Published: March 2003

The impact of permethrin‐impregnated bednets on resting and feeding behaviour of mosquito vectors of Wuchereria bancrofti, causing human lymphatic filariasis was studied in six pairs of villages (treated and untreated) before and after intervention. The study villages were in Kwale District, near the coast of Kenya, where Bancroftian filariasis is highly endemic, transmitted by a combination of both anopheline and culicine mosquito vectors. Mosquitoes were collected weekly in each village, indoors (using pyrethrum spray catches) and outdoors (using pit traps) during 3–4 months following the long rainy season. Of the filariasis vector species of mosquitoes collected in 1994 before intervention, 33.6% were members of the Anopheles gambiae complex, 30% were An. funestus and 36.4% were Culex quinquefasciatus. PCR analysis of the An. gambiae complex species collected in 1995 demonstrated that 98.5% were An. gambiae sensu stricto, 1% An. arabiensis and 0.5% An. merus.Introduction of impregnated bednets in 1995 significantly reduced the number of indoor‐resting An. gambiae s.l. by 94.6% and An. funestus by 96.7%, but there was no change in the number of Cx quinquefasciatus collected indoors. The number of outdoor‐resting An. gambiae s.l. was significantly reduced, whereas densities of An. funestus and Cx quinquefasciatus remained unaffected outdoors. ELISA analysis of mosquito bloodmeals showed a shift from human to animal feeding after the introduction of treated nets. The human blood index (HBI) for indoor resting Cx quinquefasciatus was reduced from 93.1% to 14.4%. Vector potential based on the HBI and mosquito density was estimated to be reduced by 99% for An. gambiae s.l., 98% for An. funestus and 97% for Cx quinquefasciatus and vectorial capacity would be suppressed even more by the impact on the vector survival rates (not measured). These results suggest that permethrin‐impregnated bednets give effective personal protection against transmission of W. bancrofti by An. gambiae, An. funestus and Cx quinquefasciatus in East Africa.
Visual and olfactory responses of haematophagous Diptera to host stimuli
Authors: Gibson G. , Torr S. J. 
Published: March 2003

SummaryKey biotic and environmental constraints on the host‐orientated behaviour of haematophagous Diptera are summarized. For each major group of biting Diptera, responses to host stimuli are reviewed, including activation and ranging behaviour, long‐range and short‐range olfactory responses and visual responses. Limitations to the comparison of results between groups of species, and the practical problems of experimental method and equipment are discussed.
Expression of a functional antibody fragment in the gut of Rhodnius prolixus via transgenic bacterial symbiont Rhodococcus rhodnii
Authors: Durvasula R. V. , Gumbs A. , Panackal A. , Kruglov O. , Taneja J. , Kang A. S. , Cordon‐Rosales C. , Richards F. F. , Whitham R. G. , Beard C. B. 
Published: March 2003

SummaryExpression within insects of foreign antiparasitic gene products via microbial symbionts could be used to prevent transmission of vector‐borne pathogens to vertebrate hosts. Genetically transformed symbiotic bacteria Rhodococcus rhodnii expressed functional antibody fragments (rDB3 encoding murine VH/K which binds progesterone) that were exported into the gut lumen of the triatomine bug Rhodnius prolixus (Hemiptera: Reduviidae), a vector of Chagas disease. Transgenic symbionts were maintained in successive nymphal instars and adults of Rhodnius prolixus despite competition with native untransformed Rhodococcus rhodnii. This is the first description of a functional mammalian antibody fragment expressed in an insect. Our system is a model for constructing paratransgenic insects (insects carrying transformed symbionts) with compromised ability to transmit pathogens.
The spatial distribution of larvae of Culicoides impunctatus biting midges
Authors: Blackwell A. , Lock K. A. , Marshall B. , Boag B. , Gordon S. C. 
Published: March 2003

SummaryThe spatial distribution of Culicoides impunctatus Goetghebuer (Diptera: Ceratopogonidae) larvae was sampled at a site in western Scotland, and geostatistical analyses were used to quantify spatial dependencies. Nested sampling and analysis indicated that most of the spatial variance occurred within distances of 160–640 cm, levelling off at distances > 640 cm. Semivariograms for transformed data from three 100 m × 100 m grids showed similar, isotropic patterns for larval counts, soil organic content, soil water content and the distribution of Juncus spp. rushes, with the variance increasing with separation distance. High levels of significance were associated with power models used to describe the semivariograms, which was indicative of the absence of a plateau (or ‘sill’) in the respective data. Correlation analysis of transformed data revealed significantly positive relationships between larval counts and soil pH, soil percentage organic content, soil percentage water content and also the distribution of Sphagnum spp., Juncus spp. and Myrica gale. There were also significantly negative relationships between larval counts and the distribution of Pteridium aquilinum and all mosses other than Sphagnum spp. The results suggest a far more structured and predictable pattern of C. impunctatus larval sites than previous studies and are discussed in relation to their application in localized Culicoides control and to studies of the mechanisms determining the spatial distribution of C. impunctatus larvae.