bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong rebound of wakefulness follows prostaglandin D2‐ or adenosine A2a receptor agonist‐induced sleep
Authors: Gerashchenko Dmitry , Okano Yasuhisa , Urade Yoshihiro , Inoué Shojiro , Hayaishi Osamu 
Published: March 2003

SUMMARYWe studied the effect of sleep excess on the sleep‐wakefulness pattern of rats. Subarachnoid infusion of prostaglandin D2 or the adenosine A2a receptor agonist CGS21680 effectively induced slow wave sleep (SWS) for the first 12 h of the night‐time period, whereas they did not induce sleep during the following 24 h of infusion. An increase in the amount of wakefulness was seen during the last 12 h of prostaglandin D2 infusion. The amounts of wakefulness strongly increased during the following 36‐h recovery period. Rebound wakefulness was extraordinarily strong after the cessation of CGS21680 infusion, reaching almost complete insomnia during the night‐time. Treatment of animals with prostaglandin D2 overnight, following by treatment with CGS21680 on the next night, resulted in the strongest induction of wakefulness rebound. During the rebound period, the amount of wakefulness reached up to 50 min per hour in the daytime. Rebound of wakefulness depended on the amounts of preceding SWS induced by infusion of prostaglandin D2 for 6 or 12 h and of CGS21680 for 12 h. The larger the amount of SWS, the larger the amount of the following rebound of wakefulness. Rebounds of wakefulness occurred as a result of decrease in SWS amounts, whereas paradoxical sleep amounts did not change. Desensitization of adenosine A2a receptors and accumulation of prostaglandin E2 may be involved in the production of strong wakefulness rebound following relatively long treatments (more than 12 h) with prostaglandin D2 or CGS21680.
Effects of amphetamine and modafinil on the sleep/wake cycle during experimental hypersomnia induced by sleep deprivation in the cat
Authors: Lin J. S. , Gervasoni D. , Hou Y. , Vanni‐Mercier G. , Rambert F. , Frydman A. , Jouvet M. 
Published: March 2003

SUMMARYModafinil is a newly discovered waking substance now being used in the treatment of hypersomnia and narcolepsy. We have shown previously in the cat that, unlike amphetamine, modafinil induces long‐lasting wakefulness (W) without behavioral excitation and subsequent sleep rebound, and that its waking effect does not depend on endogenous catecholamines. To further characterize the awakening properties of modafinil and current psychostimulants in experimental models of hypersomnia, we examined the effect of oral administration of placebo, modafinil (5 mg kg−1) or amphetamine (1 mg kg−1) on the sleep/wake cycle and power spectral density (PSD) in cats after an 18‐h water‐tank sleep deprivation period. We found that the placebo had no effect on the dynamics of sleep recovery, while both modafinil and amphetamine induced suppression of cortical slow activity and a waking state lasting 6–8 h. After the amphetamine‐induced waking period, both deep slow wave sleep (SWS2) and paradoxical sleep (PS) occurred in greater amounts than after placebo and the PSD during SWS was also increased. Thus, the cumulative time spent in W during a 48‐h period was similar to that with placebo, indicating enhanced sleep rebound. In contrast, after the modafinil‐induced W, the occurrence and evolution of SWS2 or PS, as well as the PSD during SWS, were similar to those seen with placebo during the same period, so that the total time spent in W in a 48‐h period remained significantly higher than the control level, indicating no additional sleep rebound. These results indicate that modafinil is effective against somnolence and hypersomnia and does not produce a subsequent increase in sleep and suggest that the pharmacological profile of modafinil is different from that of amphetamine.
Passive immunization of chronic hepatitis B patients on lamivudine therapy: a feasible issue?
Authors: Van Nunen A. B. , De Man R. A. , Heijtink R. A. , Vossen A. C. T. M. , Schalm S. W. 
Published: March 2003

In view of the limited efficacy of lamivudine monotherapy for chronic hepatitis B (HBV) infection, combination with other drugs seems logical. Intravenous neutralization of circulating HBsAg by specific hepatitis B immunoglobulin (HBIg) has been shown to protect hepatocytes against (re‐)infection with HBV in the setting of liver transplantation and postexposure prophylaxis. Large controlled vaccination trials have revealed that HBV can be prevented by HBIg therapy in the majority of newborns after perinatal infection. A benefit of anti‐HBs in HBV patients has so far only been investigated in three small studies. In this pilot study we investigated the effects of polyclonal i.v. HBIg (HepatectR, Biotest) administration in HBV‐infected patients. Six liver biopsy‐proven HBV‐infected patients, all on lamivudine treatment and HBV DNA negative by PCR, were investigated. Pre‐treatment HBsAg levels varied between 120 and 9760 ng/mL. On day 1, 10.000 IU HBIg was given, followed by 10.000 IU once, twice or three times on day 29. Long‐term follow‐up lasted at least 4 months. HBsAg and anti‐HBs were measured quantitatively by standard MEIA and also by an experimental EIA. In vitro neutralization of HBsAg by Hepatect was mimicked in an `inhibition in solution assay'.Complete neutralization of HBsAg by HBIg in vitro was possible, 50% inhibition concentrations varied between 100 and 250 IU/L HBIg with HBsAg levels of 68 and 120 ng/mL. No HBIg‐related side‐effects were observed. In two patients with low pretreatment HBsAg levels HBsAg reached levels below the detection limit of the assay, which persisted a maximum of 31 and 7.5 h, respectively. Peak anti‐HBs concentrations were 5100 and 4648 IU/L. In the other four patients, with higher pretreatment HBsAg levels, HBsAg concentrations in serum hardly changed. For the whole population, the drop in HBsAg did not reach statistical significance. However, in four of the six patients a further decrease in HBsAg [18%–66%] was observed.In conclusion, HBIg was well tolerated; however, efficacy was limited due to high HBsAg levels in spite of maximum inhibition of virion production. `Neutralization' was achieved only in two patients with low HBsAg levels. Passive immunization in HBV‐DNA negative patients is not a feasible option. This strategy seems only feasible if agents inhibiting both the production of viral proteins and Dane particles more selectively, become available.
First phase hepatitis c viral kinetics in previous nonresponders patients
Authors: Cotler S. J. , Layden J. E. , Neumann A. U. , Jensen D. M. 
Published: March 2003

summary.  A large proportion of patients fails to respond to treatment for hepatitis C. Initiation of interferon therapy is associated with a rapid first phase decline in viremia, reflecting inhibition of viral production or release from infected cells. We characterized first phase viral kinetics in previous nonresponder patients and compared the antiviral efficacy of interferon in nonresponders to that observed in naive patients. Twenty nonresponders with genotype 1 infection were evaluated. Ten received a single 15 mcg dose of interferon alfacon‐1 and ten were given a 30 mcg dose. Viral kinetic data from previously untreated historical control patients with genotype 1 infection who received 9 mcg (n = 12) or 15 mcg (n = 13) of interferon alfacon‐1 provided a basis for comparison. Antiviral efficacy was evaluated by calculating the reduction in HCV RNA levels during the first 24 h after interferon administration (log effectiveness). Hepatitis C virus levels decreased exponentially in previous nonresponder patients. Non‐responders treated with 30 mcg of interferon alfacon‐1 exhibited a greater log drop than non‐responders receiving 15 mcg (P = 0.01). The log effectiveness of 15 mcg of interferon alfacon‐1 in nonresponders was similar to 9 mcg in naives and was significantly < 15 mcg (P = 0.04) in naïve patients. The 30 mcg dose provided similar log effectiveness in nonresponders compared with 15 mcg in naive patients and exceeded the log effectiveness of 9 mcg in previously untreated patients (P = 0.035). Nonresponders who had greater than a 50% decrease in HCV RNA level from baseline at the end of previous treatment had a larger reduction in viral load at 24 h compared with those who had not achieved that level of response with prior therapy (P = 0.04). In conclusion, the log effectiveness of interferon was lower in nonresponders compared with treatment naive patients. The difference in antiviral effectiveness in previous nonresponders was overcome by higher interferon doses.
An estimate of the impact of predators on the British Field Vole Microtus agrestis population
Authors: Dyczkowski Jerzy , Yalden D. W. 
Published: March 2003

AbstractThe productivity of the British Field Vole population is estimated to be between 677 000 and 982 000 voles per year, depending on the precise basis of the calculation. The total consumption of Field Voles by all the major predators, mammalian and avian, is estimated to be around 980 000, if the very uncertain consumption by Feral Cats is included. Two specialist vole predators (Weasel, Kestrel) and two generalist predators (Red Fox, Feral Cat) consume 85% of the total between them, the other 10 species share the rest between them. However important voles might be for owls, owl predation is unimportant to voles. The slight evidence for cyclicity in Field Vole populations in Britain might be explained by the overall take of voles by the predators, and by the rather generalized diet of even the vole specialists.
Geographical variation in genet (Genetta genetta L.) diet: a literature review
Authors: Virgós E. , Llorente M. , Cortésá Y. 
Published: March 2003

AbstractThe geographical variation in the Genet Genetta genetta L. diet was analysed from 12 locations covering its entire range. Data were obtained from the available literature on food studies in this species. We studied the general food spectrum of this species and compared the importance of different prey items in each area through PCA analysis. The possible influence of some large‐scale environmental factors (latitude, altitude, Mediterraneity) on diet were studied by means of regression analysis and
anova. The study assessed the frequency of occurrence of each prey group and diet diversity. Results show the existence of two ‘food’ groups: (i) Genets which feed on a wide food spectrum, especially arthropods and (ii) Genets which feed on small mammals at a high frequency, while the remaining prey items are scarce or absent. At the intraspecific level, Genets behave as generalist species, with the small mammals (especially, the Woodmouse) as the most outstanding prey item. However, when compared with the diet of other medium‐sized Palaearctic carnivores, we can say that the Genet is intermediate between typical generalists (Martens Martes spp., Red Foxes Vulpes vulpes and Badgers Meles meles) and specialists (Otters Lutra lutra, Stoat Mustela erminea and Weasel Mustela nivalis). Finally,
anova shows the existence of a relationship between diet diversity and Mediterraneity (associated with taxa such as arthropods, reptiles and amphibians), but no relationship was found for latitude or altitude. The importance of interspecific competition, based on island data, is discussed.
The use of fumigants and anticoagulant rodenticides on game estates in Great Britain
Authors: Mcdonald Robbie A. , Harris Stephen 
Published: March 2003

ABSTRACTSeveral studies have highlighted the potential risk to nontarget wildlife associated with accidental exposure to vertebrate control agents. In order to provide information that may assist in the mitigation of this problem, we questioned 215 gamekeepers in Great Britain about the use of vertebrate control agents on the land for which they were responsible. Fumigants were used to control Rabbits Oryctolagus cuniculus by 59% of gamekeepers. Use of fumigants was more common than on farms in general. 91% of gamekeepers reported the use of rodenticides, 95% of which were anticoagulants. Patterns of rodenticide use were similar to those on arable farms, though chlorophacinone and warfarin were used more commonly on game estates. Future studies of the exposure of nontarget wildlife to anticoagulants should be expanded to include these compounds. Rodenticides were apparently used in accordance with label recommendations in most cases. However, better information and guidelines for users may improve standards of agent application and reduce potential risks to nontarget wildlife.
The palaeoecology of the Vombatidae: did giant wombats burrow?
Authors: Woolnough Andrew P. , Steele Vernon R. 
Published: March 2003

ABSTRACTDebate over the origins of burrowing in the Vombatidae has continued since the discovery of the remains of the largest of all wombats, Phascolonus gigas, in the nineteenth century. In this paper, we argue that the largest of the ancestors of extant wombats did not burrow due to physical and physiological limitations of burrows. Further, we suggest that the burrowing characteristics of the extant wombats were derived from an ancestor of similar body size (20–40 kg) that is presently not represented in the fossil record.
Bark consumption by small rodents in the northern and southern hemispheres
Authors: Baxter R. , Hansson L. 
Published: March 2003

ABSTRACTThe distribution and environmental conditions of bark consumption by small rodents were compiled for the northern and southern hemispheres. Main bark consumption occurred under snow at peak cyclic density and in the dry season of annually fluctuating rodent populations, respectively. The species responsible appeared more folivorous in the north. Among woody species that are damaged, a large number were in both cases exotics. Various defences against bark consumption have evolved, including secondary compounds. However, this defence appears inadequate when indigenous trees are grown under new environmental conditions. It is pointed out that the stem and bark are very sensitive components of perennial trees and bushes and that this potential but usually well protected resource will only be used in crucial situations by various mammals. In view of the many unsuccessful attempts to prevent small rodent damage by bark consumption, costs for rodent damage should be included in any cost–benefit analyses for plantations of exotic species or indigenous species under new conditions. Screening and even selection for resistant varieties may be needed at large scale plantations.
The beaver's reconquest of Eurasia: status, population development and management of a conservation success
Authors: HALLEY D. J. , ROSELL F. 
Published: March 2003

ABSTRACTOverhunting reduced Eurasian Beaver (Castor fiber) populations to c. 1200 animals, in eight isolated populations, around the end of the 19th century. Protection, natural spread and reintroductions led to a powerful recovery in both range and populations during the 20th century, which continues at a rapid pace. The minimum population estimate is 593 000. There are also c. 12 500 North American Beaver (C. canadensis) established in Finland and Russian Karelia; however, other populations of C. canadensis introduced in Austria, Poland and France ap‐pear to be extinct. Castor fiber is now established throughout Europe with the exception of the British Isles, Iberia, Italy and the southern Balkans; reintroductions are continuing. Considerable further expansion in range and population, especially in western Europe and the lower Danube basin, can be expected. If current trends continue, C. fiber will, within a few decades, be a fairly common mammal in much of Europe. Following initial recolonization, populations typically show a pattern of rapid range extension within a watershed, followed only later by rapid population growth, and a barrier effect of watershed divides, which can be strongly isolating where physical or habitat barriers (such as mountains or intensive farmland) intrude between watersheds. Management of beaver distribution should therefore operate at the watershed scale, except where large human‐made dams form significant bar‐riers to spread. The period of rapid population increase, if unchecked, leads to a phase of population decline as marginal habitats are occupied and exhausted. This coincides with a peak in conflicts with human land‐use interests. A regulated hunting take of healthy beaver populations is recommended as the optimal management regime in managed landscapes. Early provision of interpretation and public viewing opportunities has been a feature of several recent reintroductions. This provides a benefit to the local economy through wildlife tourism, and helps foster positive attitudes to beavers.
Culicoides in relation to transmission of African Horse Sickness virus in The Gambia
Authors: RAWLINGS  , SNOW  , BOORMAN  , DENISON  , HAMBLIN  , MELLOR  
Published: March 2003

Twelve light trap collections made near overnight shelters of horses and donkeys in four villages in the Central River Division of The Gambia captured fourteen species of biting midge of the genus Culicoides. Five species new to The Gambia were identified. This brought the number of recognized species of Culicoides (after a revision of C. schultzei) to twenty‐nine in The Gambia. Species known or suspected as vectors of African horse sickness virus (AHSV) and bluetongue virus (BTV) comprised 83% of female captures, 65% of captures being C. imicola or its sibling species, C. miombo. Captures of female Culicoides in the late dry season were almost as large as in the early dry season, despite the extreme heat and dryness at this time of the year.Tests on batches of formalin‐preserved female midges, using AHSV or BTV antigen capture ELISAs, did not show the presence of any virus amongst 2286 females in 240 aliquots. Nearly all Gambian equines are reportedly seropositive to AHSV and these results suggest that virus challenge from Culicoides vectors may be a factor in the health of Gambian horses and donkeys.
Pyrethroid resistance inCulex quinquefasciatusfrom West Africa
Authors: Chandre F. , Darriet F. , Darder M. , Cuany A. , Doannio J. M. C. , Pasteur N. , Guillet P. 
Published: March 2003

Laboratoire de Lutte contre les Insectes Nuisibles, ORSTOM, Montpellier, France, *OCCGE, Institut Pierre Richet, BP 1500, Bouaké 01, Côte d'Ivoire, †INRA, Laboratoire de Biologie des Invertébrés, 123 Bd Meilland, 06606 Antibes, France, and ‡CNRS UMR 5554, Laboratoire de Génétique et Environnement, Institut des Sciences de l'Environnement, Université de Montpellier II (CC 065), 34095 Montpellier, France Abstract.Pyrethroid resistance was investigated in thirty‐three samples of Culex quinquefasciatus Say from twenty‐five cities in Côte d'Ivoire and Burkina Faso. Permethrin resistance ratios at LC50 ranged from 9.5‐ to 82‐fold in Côte d'Ivoire and from 17‐ to 49‐fold in Burkina Faso. For deltamethrin, resistance ratios were lower and ranged from nine to thirty‐eight in both countries. A strain was selected with permethrin to investigate resistance mechanisms. After forty‐two generations of selection, permethrin resistance level reached 3750‐fold, but deltamethrin resistance remained unexpectedly unchanged. This indicated that a specific mechanism was involved in permethrin resistance. Synergist assays and biochemical tests indicated that resistance was partly due to P450‐dependent oxidases. A target site insensitivity (kdr) was also involved, associated with DDT cross resistance and a dramatic loss of permethrin knockdown effect on adults. This resistance should be taken into consideration when planning the use of pyrethroid‐impregnated materials in urban areas, as Culex is by far the main source of nuisance. Any failure in nuisance control due to resistance is likely to demotivate people in using impregnated materials.
Efficiency and cost of strategic use of acaricide for tick control in N’Dama cattle in The Gambia
Authors: Mattioli R. C. , Jaitner J. , Bah M. 
Published: March 2003

SummaryThe efficiency of strategic and strategic/selective applications of flumethrin spray formulation for controlling ticks were assessed, respectively, in two groups of fourteen N’Dama cattle (Group S and Group S/S) by comparison of the number of feeding ticks with thirteen untreated N’Dama cattle (Group U) over a period of 11 months (June 1996 to April 1997). During the expected peak of tick abundance, acaricide was applied fortnightly on the whole body in animals in Group S and only on the most infested body areas in cattle in Group S/S. Weight changes and skin lesions, directly associated with tick attachment, were recorded in cattle in the three groups. The costs of the two tick control schemes were estimated. Maximum level of ticks, all species together, feeding on cattle was observed in the rainy season. Both in Group S/S and Group S, cattle carried a lower (P < 0.001) number of feeding ticks than animals in Group U over the whole study period. Percentage of tick control, over the entire period of tick investigation, was satisfactory in both acaricide‐treated groups, reaching 61.2 and 75.2% in Groups S/S and S, respectively. However, the proportion of control varied according to tick species or genus. Significantly lower prevalence of skin lesions was observed on the ano‐genital and udder region in cattle in Group S/S (P < 0.05) and Group S (P < 0.01) in comparison with cattle in Group U. Mean amount of acaricide solution used and relative estimated cost of treatment in cattle in Group S/S were, respectively, 25‐ and 14‐fold lower than those in cattle in Group S. At the end of the study, animals in Groups S/S and S were, respectively, 7.2 and 15.9 kg heavier than animals in Group U. The difference was statistically significant (P < 0.02) only between Groups S and U. However, the efficiency, low cost and derived benefits of the strategic/selective acaricide application scheme indicated that it might be the most cost effective.
Distribution of domestic Triatominae and stratification of Chagas Disease transmission in Oaxaca, Mexico
Authors: Ramsey J. M. , Ordoñez R. , Cruz‐Celis A. , Alvear A. L. , Chavez V. , Lopez R. , Pintor J. R. , Gama F. , Carrillo S. 
Published: March 2003

SummaryMexico has 18 species of Triatomine bugs (Hemiptera: Reduviidae) reported to be vectors of Trypanosoma cruzi. Chagas Disease is widespread in Mexico, with up to 3.5% seropositivity of human transfusion blood. The State of Oaxaca has the longest history of endemic Chagas Disease, based on acute and chronic case reports, and of entomological surveys in the country. However, the State health care services need more information on current risks of vector transmission. In order to identify and characterize areas of transmission in Oaxaca and to stratify the vector potential, the distribution of domestic Triatominae was surveyed during 1996–98 in collaboration with the primary health care services and local communities. Villages were studied in 11% of 570 municipalities in Oaxaca. Eight triatomine species were found in domestic and peri‐domestic habitats: Triatoma barberi Usinger, T. bolivari Carcavallo et al. T. dimidiata (Latreille), T. mazzottii Usinger, T. nitida Usinger, T. pallidipennis (Stal), T. phyllosoma (Burmeister) and Rhodnius prolixus Stal. For each triatomine species in Oaxaca, the range of distribution and habitat characteristics are described. Habitat partitioning, principally based on altitude and mean annual precipitation, limited the overlap of distribution between species. Relatively consistent altitude of human settlements facilitates the dispersion of individual species within microregions. Entomological indices of house infestation were used to estimate that ∼50% of the human population (1874 320 inhabitants) would be at risk of vector transmission, with a minimum of 134 320 infected people and 40 280 chronic cases of Chagas Disease currently in Oaxaca.