bluuebunny/crossref_metadata_2025 huggingface dataset:
The spatial and seasonal distribution of African horse sickness and its potential Culicoides vectors in Morocco
Authors: BAYLIS M. , HASNAOUI H. EL , BOUAYOUNE H. , TOUTI J. , MELLOR P. S.
Published: March 2008

Abstract African horse sickness (AHS) is a vector‐borne, infectious disease of equines that is caused by African horse sickness virus (AHSV). The only proven field vector is the biting midge Culicoides imicola, although C.obsoletus and C.pulicaris are suspected vectors. There was a recent epizootic of AHS in Iberia (1987‐90) and Morocco (1989‐91). In 1994‐45 a total of 3887 light trap samples were taken from twenty‐two sites distributed over most of Morocco. Culicoides imicola was found to be very widely dispersed, with the greatest catches in the low‐lying northwestern areas (between Tangier and Rabat) and at Marrakech. Culicoides imicola was absent at one site only, near Settat. Culicoides imicola was found at altitudes ranging from 4 to 1275 m and in climatic conditions ranging from subhumid to saharan. In general, the catch of C.imicola peaked in late summer and autumn, with a smaller peak in spring. In areas where the insect appears most abundant at least one adult C.imicola per night may be caught in a light trap at all times of year, thus providing a possible means of viral overwintering. Culicoides obsoletus and C.pulicaris are also widely distributed in Morocco but trap catches were much lower than for C.imicola. Peak catches occurred in spring, and late summer and autumn. Other frequently caught species were C.circumscripta, C.newsteadi, C.puncticollis and members of the odibilis subgenus. In general, the findings for C.imicola correspond well with the distribution of disease outbreaks during the epizootic. Although disease outbreaks were widespread in the country, die greatest number of reported cases was in the northwest (1989‐90); in 1991 there were also significant numbers in Marrakech province. No cases were reported in a large area to the west of the Atlas mountains (including Settat) despite the presence of a large equine population. It is likely that during the epizootic the virus overwintered in the northwest (1989) and in Marrakech province (1990). Disease outbreaks occurred from July to December, with a peak from September to November. An unexplained phenomenon is the large number of reported cases of AHS in mules in Chefchaouen province in 1990, despite the apparent low abundance of C.imicola at a site at Chefchaouen. It is argued that C.obsoletus and C.pulicaris were probably of little significance to the epidemiology of AHS in Morocco in 1989‐91.
Blowfly species composition in sheep myiasis in Scotland
Authors: MORRIS OWEN S. , TITCHENER RICHARD N.
Published: March 2008

Abstract Samples of dipteran larvae were collected from live sheep throughout Scotland, reared in the laboratory, and identified once adult flies emerged. Lucilia sericata was found in 77% of samples, and other species in 49%. The most common alternative species were L.caesar, which occurred in 31 % of samples, and Protophormia terraenovae, which occurred in 18%. Three other calliphorid species, Calliphora vomitoria, C.vicina and Lillustris, and the muscid Muscina pabulorum were also found. The proportion of samples containing alternative species was significantly lower in eastern Scotland than in western Scotland. Significantly higher proportions of samples containing alternative species were collected at altitudes of 200 m and above; from sheep of hill breeds; from rough grazing conditions and moorland; in the absence of trees; and in the presence of bracken.
The effects of hair density of beef cattle on Haematobia irritans horn fly populations
Authors: STEELMAN C. D. , BROWN M. A. , GBUR E. E. , TOLLEY G.
Published: March 2008

Abstract We show the relationships that exist between the amount of hair and quantity of sebum on cattle skin and the population density of the horn fly, Haematobia irritans. Brahman and Chianina steers had means of 2390 and 1587 hairs per cm2, respectively, significantly more than the mean number of hairs on Angus, Brahman x Angus Crossbred, Charolais, and Red Poll steers. The Chianina steers had > 30% more sebum present on their skin and hair (0.58g/929cm2) than the Angus, Charolais, and Red Poll steers at the Beef Cattle Research Station Savoy, Arkansas. The Brahman steers had a significantly greater amount of sebum present on the skin (1.51 g/ 929 cm2) than the Crossbred and purebred Angus steers (0.55 and 0.25g/929cm2, respectively) at the South Central Family Farms Research Centre Booneville, Arkansas. The Brahman and Chianina steers had means of 61.9 and 17.0 horn flies per steer, respectively, during the fly season, whereas the Angus, Crossbred, Charolais and Red Poll steers had fly season means that ranged from 76.9 to 265.8 flies per steer. Regression analysis showed that an increase of 100 hairs per cm2, was associated with a reduction of 11 horn flies in the Angus II, 5 in Angus I, 20 in Charolais, 37 in Red Poll, and 0.4 in Chianina steers at the Savoy Station and a reduction of 6.6 horn flies for the Angus, Brahman, and Crossbred steers at the Booneville Centre. Regardless of cattle breed, an increase of 1.0 g of sebum per 929 cm2 output by the steer was associated with 478.5 additional hairs per cm2 on the animal. Each increase of 0.25 g of sebum per 929 cm2 resulted in a decrease of 9.2 horn flies per steer. We conclude that some of the factors responsible for fly‐resistance in cattle are hair density and the corresponding amount of sebum present on cattle skin and hair.
Immunology of interactions between ticks and hosts
Authors: BROSSARD M. , WIKEL S. K.
Published: March 2008

Abstract Infestation with ixodid tick stimulates the immune regulatory and effector pathways of the hosts involving antigen presenting cells, T‐lymphocytes, B‐lymphocytes, basophils, mast cells, eosinophils and a variety of bioactive molecules like cytokines, antibodies and complement. Tick‐mediated immunosuppression has been investigated using cells derived from infested animals and by exposing cells from uninfested animals to tick salivary gland molecules. Tick‐induced suppression of host immune defences is characterized by reduced ability of lymphocytes from infested animals to proliferate m vitro in the presence of concanavalin A (Con A), diminished primary antibody responses to T‐cell dependent antigen, and decreased elaboration of macrophage (IL‐1 and TNF‐α) and Th 1 ‐lymphocyte cytokines (IFN‐γ), whereas Th2 cytokines production (IL‐4, IL‐5 and IL‐10) isenhanced. It is known that IL‐10 inhibits Thl cell development and also reduces the in vitro T‐lymphocyte proliferative response to Con A stimulation. Proteins which inhibited T‐lymphocyte in vitro responsiveness to Con A were also isolated from tick salivary glands.
Tick saliva: recent advances and implications for vector competence
Authors: BOWMAN A. S. , COONS L. B. , NEEDHAM G. R. , SAUER J. R.
Published: March 2008

Abstract . Secretions of the tick salivary glands are essential to the successful completion of the prolonged feeding of these ectoparasites as well as the conduit by which most tick‐borne pathogens are transmitted to the host. In ixodid ticks the salivary glands are the organs of osmoregulation, and excess water from the bloodmeal is returned via saliva into the host. Host blood must continue to flow into the feeding lesion as well as remain fluid in the tick mouthparts and gut. The host's haemostatic mechanisms are thwarted by various anti‐platelet aggregatory, anticoagulatory and anti‐vasoconstrictory factors in tick saliva. Saliva components suppress the immune and inflammatory response of the host permitting the ticks to remain on the host for an extended period of time and, adventitiously, enhancing the transmission and establishment of tick‐borne pathogens. Over the years much work has been done on the numerous enzyme and pharmacological activities found in the tick saliva. The present article reviews the most recent work on salivary gland secretionith special emphasis on how they favour pathogen transmission.
First record in America of Aedes albopictus naturally infected with dengue virus during the 1995 outbreak at Reynosa, Mexico
Authors: IBÁÑEZ‐BERNAL SERGIO , BRISEÑO BALTASAR , MUTEBI JOHN PAUL , ARGOT ENID , RODRÍGUEZ GUADALUPE , MARTINEZ‐CAMPOS CARMEN , PAZ RAFAEL , ROMÁN PEDRO DE LA FUENTE‐SAN , TAPIA‐CONYER ROBERTO , FLISSER ANA
Published: March 2008

Abstract Mosquito collections were conducted during a dengue outbreak in Reynosa, Tamaulipas, Mexico, July‐December 1995. A total of 6694 adult mosquitoes (four genera and nine species) were captured, of which 2986 (78.3% females and 21.7% males) were Aedes albopictus and 2339 (39.7% females and 60.3% males) were Ae.aegypti. These two species comprised 84.2% of the total collection. Specimens were grouped into pools, nearly 50% of them processed for detection of virus by cythopathic effect in C6‐36 and VERO cell cultures and by haemagglutination test. Five pools gave positive haemagglutin‐ation reactions and were examined by immunofluorescence using monoclonal antibodies to flavivirus and to dengue virus. One pool of ten Ae.albopictus males was positive for dengue virus: serotypes 2 and 3 were identified by serotype‐specific monoclonal antibodies arid confirmed by RT‐PCR. This is the first report of Ae.albopictus naturally infected with dengue virus in America. Also, it is the very first time Ae.albopictus males have been found infected with dengue virus in the wild.
Stable fly, Stomoxys calcitrans, mouthpart removal influences stress and anticipatory responses in mice
Authors: COLWELL DOUGLAS D. , KAVALIERS MARTIN , LYSYK TIMOTHY J.
Published: March 2008

Abstract Biting fly attack induces a variety of stress and anxiety related changes in the physiology and behaviour of the target animals. Significant reductions in pain, or more appropriately, nociceptive sensitivity (latency of a foot‐lifting response to an aversive thermal stimulus), are evident in laboratory mice after a 1 h exposure to stable flies, Stomoxys calcitrans. The role of the various components of biting fly attack in the development of this stress‐induced reduction in pain sensitivity (analgesia) is, however, unclear. This study demonstrates that fly‐naive mice do not exhibit a stress‐induced analgesia when exposed to stable flies whose biting mouthparts have been removed. In contrast, mice that have been previously exposed to intact stable flies exhibit significant analgesia when exposed to flies that are incapable of biting. However, the level of analgesia induced is lower than that elicited by exposure to intact stable flies. Exposure to non‐biting house flies, Musca domestica, has no effect on nociceptive sensitivity. It appears that the actual bite of the stable fly is necessary for the induction of analgesia and probably other stress and anxiety associated responses in fly naive mice. However, mice rapidly learn to recognize biting flies and exhibit significant, possibly anticipatory analgesic responses to the mere presence of biting flies.
Immunization of rabbits with faecal extract of Pediculus humanus, the human body louse: effects on louse development and reproduction
Authors: MUMCUOGLU K. Y. , BEN‐YAKIR D. , OCHANDA J. O. , MILLER J. , GALUN R.
Published: March 2008

Abstract Immunization of rabbits with a faecal extract of the human body louse (Pediculus humanus) induced a high titre of specific IgG. The mean weight of Wood taken by females fed on the immunized rabbits was significantly lower (29%) than taken by females fed on the control rabbits. The mean number of eggs per female fed on the immunized rabbits was significantly lower than for females fed on the control rabbits. The hatchability of the eggs laid by lice fed on immunized rabbits (91%) was significantly lower than of those fed on control rabbits (94%). The rate of development of nymphs fed on control rabbits was significantly higher than those fed on the immunized rabbits. There was no difference in survival rates of lice fed on immunized and control rabbits.
The sandfly Lutzomyia longipalpis shows specific humoral responses to bacterial challenge
Authors: NIMMO DERRIC D. , HAM PETER J. , WARD RICHARD D. , MAINGON RHAIZA
Published: March 2008

Abstract The presence of immune molecules induced by microorganisms in the haemolymph of Lutzomyia longipalpis sandflies has been investigated. Injections of Escherichia coli and Micrococcus luteus into female sandflies induced anti‐bacterial activity in the haemolymph. Inhibition zone assays showed that haemolymph from E.coli and M.luteus injected sandflies differentially inhibited M.luteus growth. This differential effect was specific to M. luteus infection since anti‐Zs. coli activity was similar in haemolymph from both E.coli oxM.luteus injected sandflies. Haemolymph following injection of either bacteria showed the induction of a 4kDa peptide. Haemolymph from M.luteus injected sandflies also contained a 33 kDa polypeptide which was absent in haemolymph from E.coli and control uninfected insects. Sandflies, in common with other insects, were shown to possess general and specific humoral immune responses to the presence of microorganisms.
The potential for control of the blowfly Lucilia sericata using odour‐baited targets
Authors: WALL R. , SMITH K. E.
Published: March 2008

Abstract A deterministic simulation model is used to explore the potential for control of the sheep blowfly, Lucilia sericata, using odour‐baited targets. The simulations show that the ambient temperatures of 15oC or 20oC, 13% and 24% of the females present in a population would need to be killed per day, respectively, to prevent the population growing from its initial spring density during the summer blowfly season. In contrast, if both sexes could be sterilized, so that sterilized males were also able to disrupt the fertility of unsterilized females, only 6.5–13% of both sexes would need to be attracted and sterilized at 15oC or 20oC respectively. To examine whether these numbers of individuals could be attracted by targets baited with liver and sodium sulphide, mark‐release‐recapture studies in sheep pastures were used to quantify sticky target efficiencies. The percentage of the Lsericata population caught on any one day was shown to be positively related to average ambient temperature. At 15oC each sticky target caught approximately 13% and at 20oC, 41% of the females within a 20 m radius. The results indicate that, at ambient temperatures between 15 and 20oC, if distributed at a density of approximately 5/ha, targets baited with liver and sodium sulphide could effectively suppress a population of L.sericata. Lower densities of targets would be required if they were able to sterilize both sexes rather than kill or if more attractive synthetic semiochemical baits could be developed.
Aedes polynesiensis in the Society Islands: environmental correlates of isoenzyme differentiation
Authors: SHIU SYLVIANE , MERCER DAVID R. , MARTIN PAUL M. V. , RODHAIN FRANCOIS , RAYMOND MICHEL , FAILLOUX ANNA‐BELLA
Published: March 2008

Abstract Isoenzyme genetic differentiation of Aedes polynesiensis mosquitoes in Raiatea island, French Polynesia, was evaluated by two models of population structure based on seven gene‐enzyme systems: Ak, Est, Got, Gpi, Hk, Mdh and Pgm. The ecological model tested whether genetic differentiation is congruent with habitat differences. The isolation model evaluated whether genetic differentiation is proportional to geographical distribution. The ecological model found no significant differentiation between populations of Ae.polynesiensis from beach and forest ecotopes, whereas the isolation model was consistent with the data. However, incipient speciation is opposed by the source‐sink system of population dynamics in such small neighbouring islands, where Ae.polynensiensis extinction is readily followed by reinvasion causing considerable gene flow between island populations.
Diel flight periodicity of the biting midge Culicoides impunctatus and the effects of meteorological conditions
Authors: BLACKWELL ALISON
Published: March 2008

Abstract The hourly flight periodicity of adults of the biting midge Culicoides impunctatus was sampled at a site in Western Scotland, using suction traps over 18 days in July/August 1994. In addition, meteorological conditions were logged continuously. Female but not male C. impunctatus had a bimodal pattern of activity, with peaks at dawn and dusk. The dawn peak (05.00–07.00 hours) was most distinct. Correlation analysis revealed significantly positive relationships between catches of female midges and both relative humidity and rainfall, and negative relationships with wind velocity. The calculation of partial correlation coefficients reinforced the influence of relative humidity on female activity, and highlighted a further positive relationship with air temperature. Male C.impunctatus activity was negatively correlated with air temperature, although the total male catch was relatively small (15% of total trap catches) and further data would be required to confirm this result. Overall, the results help to clarify previous confusion as to whether C.impunctatus has a circadian rhythm of activity, with the data matching closely predictions of a bimodal pattern. Clearly, this pattern will be damped by meteorological conditions, which may vary greatly on a local scale.
Effects of chickens on the prevalence of infestation and population density of Triatoma infestans in rural houses of north‐west Argentina
Authors: CECERE MARÍA C. , GÜRTLER RICARDO E. , CHUIT ROBERTO , COHEN JOEL E.
Published: March 2008

Abstract Effects of the presence of chickens on population density of the bug Triatoma infestans, principal vector of Chagas disease, were investigated by standardized sampling (indoors and peridomestically) from sixty‐eight houses of three rural communities in north‐west Argentina, during March 1992.

The domiciliary density of T. infestans increased linearly with the percentage of bugs that fed on chickens, as identified by agar double‐diffusion tests. Bug density was significantly higher in houses where hens usually nested indoors than in those where they did not, as determined by concurrent direct observations and interviews of householders. Multiple linear regression analysis of domiciliary bug density on (a) the total number of people, dogs and cats per house; (b) the percentage of domiciliary bugs that fed on chickens, or (c) the indoor‐brooding habit of hens, showed the two variables (b, c) related to chickens as significant predictors in each regression model. Inclusion both variables representing chickens increased the fit significantly. Addition of other potentially confounding factors (domestic insecticide use, type of roof and walls of house) did not affect the significant variables retained in the best‐fitting regression model.

Peridomestic infestation was positively associated with the household number of fowls. Chickens were the main bloodmeal source of peridomestic T.infestans populations. Human‐fed bugs were detected in peridomestic sites of sixteen houses, indicating active dispersal of adults and large nymphal instars from bedroom areas.

Exclusion of hens from domiciliary areas and promotion of chicken sheds, of an appropriate design that would not harbour bug populations, should limit the triatomine population growth rate and reduce the risk of infestation.
Isozymic and metric variation in the Lutzomyia longipalpis complex
Authors: DUJARDIN JEAN‐PIERRE , TORREZ E. M. , PONT F. LE , HERVAS D. , SOSSA D.
Published: March 2008

Abstract Male Lutzomyia longipalpis of two types from Bolivia were compared using isozyme electrophoresis and wing morphometry. One sample (ex Chiflonkaka Cave, alt. 2800 m at Toro Toro, Charcas Province, Potosi Department) was ‘two‐spot’ phenotype males (i.e. tergites III and IV with paired pale patches of pheromone glands), whereas two other locality samples (Apa Apa and Imanaco, Sud Yungas Province, La Paz Department) were one‐spot male phenotype (only tergite IV with paired pale patches). Multilocus enzyme electrophoresis (using ACON, aGPD, GPI, IDH, MDH, ME, 6PGD, PGM, LAP and PEPB) found no difference between samples from adjacent hen houses at Apa Apa. Nei's standard genetic distance between one‐spot samples from Apa Apa and Imanaco (5 km apart, 1500m alt.) was 0.001‐0.002, whereas the two‐spot males from Toro Toro (800 km away) showed a genetic distance of 0.081 from the one‐spot males (Apa Apa and Imanaco). This genetic distance is commensurate with speciation, but may simply be intraspecific differentiation due to ‘isolation by distance’.

For comparative wing morphometry, we included additional material of one‐spot males from Bolivia (Guyabal, Sud Yungas, La Paz), Brazil, Colombia and Nicaragua. These three other country samples were assumed to be different sibling species in the complex Lutzomyia longipalpis (Lanzaro et al, 1993). Statistics were based on univariate and multivariate analysis. The comparison between size‐in and size‐free canonical variate analysis (CVA) indicated that the wing morphometric divergence between one‐spot and two‐spot Bolivian phenotypes was not size dependent and could have taxonomic significance.
Dynamic morphology of plastids and stromules in angiosperm plants
Authors: HANSON MAUREEN R. , SATTARZADEH AMIRALI
Published: March 2008

Labelling of plastids with fluorescent proteins has revealed the diversity of their sizes and shapes in different tissues of vascular plants. Stromules, stroma‐filled tubules comprising thin extensions of the stroma surrounded by the double envelope membrane, have been observed to emanate from all major types of plastid, though less common on chloroplasts. In some tissue types, stromules are highly dynamic, forming, shrinking, attaching, releasing and fragmenting. Stromule formation is negatively affected by treatment of tissue with cytoskeletal inhibitors. Plastids can be connected by stromules, through which green fluorescent protein (GFP) and fluorescently tagged chloroplast protein complexes have been observed to flow. Within the highly viscous stroma, proteins traffic by diffusion as well as by an active process of directional travel, whose mechanism is unknown. In addition to exchanging materials between plastids, stromules may also serve to increase the surface area of the envelope for import and export, reduce diffusion distance between plastids and other organelles for exchange of materials, and anchor the plastid onto attachment points for proper positioning with the plant cell. Future studies should reveal how these functions may affect plants in adapting to the challenges of a changing environment.
An Arabidopsis homolog of the bacterial peptidoglycan synthesis enzyme MurE has an essential role in chloroplast development
Authors: Garcia Marlon , Myouga Fumiyoshi , Takechi Katsuaki , Sato Hiroshi , Nabeshima Kazuma , Nagata Noriko , Takio Susumu , Shinozaki Kazuo , Takano Hiroyoshi
Published: March 2008

Enzymes encoded by bacterial MurE genes catalyze the ATP‐dependent formation of uridine diphosphate‐N‐acetylmuramic acid‐tripeptide in bacterial peptidoglycan biosynthesis. The Arabidopsis thaliana genome contains one gene with homology to the bacterial MurE:AtMurE. Under normal conditions AtMurE is expressed in leaves and flowers, but not in roots or stems. Sequence‐based predictions and analyses of GFP fusions of the N terminus of AtMurE, as well as the full‐length protein, suggest that AtMurE localizes to plastids. We identified three T‐DNA‐tagged and one Ds‐tagged mutant alleles of AtMurE in A. thaliana. All four alleles show a white phenotype, and A. thaliana antisense AtMurE lines showed a pale‐green phenotype. These results suggest that AtMurE is involved in chloroplast biogenesis. Cells of the mutants were inhibited in thylakoid membrane development. RT‐PCR analysis of the mutant lines suggested that the expression of genes that depend on a multisubunit plastid‐encoded RNA polymerase was decreased. To analyze the functional relationships between the MurE genes of cyanobacteria, the moss Physcomitrella patens and higher plants, a complementation assay was carried out with a P. patens (Pp) MurE knock‐out line, which exhibits a small number of macrochloroplasts per cell. Although the Anabaena MurE, fused with the N‐terminal region of PpMurE, complemented the macrochloroplast phenotype in P. patens, transformation with AtMurE did not complement this phenotype. These results suggest that AtMurE is functionally divergent from the bacterial and moss MurE proteins.
PRECLINICAL STUDY: Disposition of Δ9tetrahydrocannabinol in CF1 mice deficient in mdr1a P‐glycoprotein
Authors: Bonhomme‐Faivre Laurence , Benyamina Amine , Reynaud Michel , Farinotti Robert , Abbara Chadi
Published: March 2008

P‐glycoprotein (P‐gp) plays a major role in drug efflux. All the transported substrates are more or less hydrophobic and amphiphatic in nature. Being lipophilic, Δ9tetrahydrocannabinol (THC), the main cannabis component, could be a potential P‐gp substrate. The aim of this project was to determine the contribution of the mdr1a gene product to THC disposition. Therefore, oral THC and digoxin (substrate test for P‐gp) pharmacokinetics have been investigated in the intestinal epithelium and in the brain capillary endothelium of CF1 mdr1a (−/−) mice (mice naturally deficient in P‐gp). These pharmacokinetics were compared to THC and digoxin oral pharmacokinetics in wild type mice mdr1a (+/+) (not P‐gp deficient). The application of Bailer's method showed that THC total exposure measured by the area under the plasma concentration time curve was 2.17‐fold higher in CF1 mice naturally deficient in P‐gp than in wild type mice after oral administration of 25 mg/kg of THC, and 2.4‐fold higher after oral administration of 33 µg/kg of digoxin. As a consequence, the oral bioavailability of THC and digoxin was higher in naturally P‐gp‐deficient mice. We concluded that P‐gp limits THC oral uptake and mediates direct drug excretion from the systemic circulation into the intestinal lumen.
GENETIC STUDY: Smoking status moderates the association of the dopamine D4 receptor (DRD4) gene VNTR polymorphism with selective processing of smoking‐related cues
Authors: Munafò Marcus R. , Johnstone Elaine C.
Published: March 2008

Recently, a variable number of tandem repeats (VNTR) polymorphism in the dopamine D4 receptor (DRD4) gene has been reported to be associated with greater craving and more attention to smoking cues, following a cue‐elicited craving procedure. We investigated whether the DRD4 VNTR 7‐repeat polymorphism is associated with selective processing of smoking‐related stimuli, using a modified Stroop task, and whether smoking status moderates this association. Thirty‐one current smokers and 17 ex‐smokers attended a single testing session and completed the modified Stroop task. The experimental design included two between‐subjects factors of smoking status (current smoker, ex‐smoker) and DRD4 genotype (short, long). The DRD4 VNTR polymorphism was associated with selective processing of smoking‐related stimuli in ex‐smokers but not in current smokers. Our data, therefore, provide partial support for our primary hypothesis and extend on previous work which suggests a role for variation at the DRD4 locus in modulating reactivity to drug‐related cues.
PRECLINICAL STUDY: Effects of bupropion, alone or coadministered with nicotine, on social behavior in mice
Authors: Gómez Carmen , Carrasco Carmen , Redolat Rosa
Published: March 2008

Bupropion, administered alone or combined with nicotine, is presently used to treat nicotine dependence. Despite experimental evidence of the complex behavioral actions of this drug, there have been little data reported about its effects on social behavior. Our main aim was to investigate the effects of acute administration of bupropion, alone or plus nicotine, on social interaction in mice. OF1 group‐housed male mice were confronted in a neutral cage with an anosmic opponent during a 10 minutes encounter. Time allocated to body care and digging was reduced by administration of bupropion (40 mg/kg) both when administered alone and with nicotine (1 and 0.5 mg/kg). The lowest dose of bupropion (10 mg/kg) also reduced digging when combined with 1 mg/kg of nicotine. Time spent on non‐social exploration and exploration from a distance was significantly higher in mice treated with bupropion (40 mg/kg) alone or combined with nicotine (1 and 0.5 mg/kg). The lowest dose of bupropion (10 mg/kg) increased non‐social exploration when combined with 0.5 mg/kg of nicotine and exploration from a distance when combined with 1 mg/kg of nicotine. Ethopharmacological assessment of the behavior of groups of mice treated with different combinations of the two drugs indicates that nicotine can potentiate some of the behavioral effects of low doses of bupropion. Results also indicate that bupropion, either alone or combined with nicotine, has no significant effects on social investigation, suggesting that this drug does not induce a clear anxiolytic profile in OF1 mice.
PRECLINICAL STUDY: Protracted ‘anti‐addictive’ effects of adolescent phenylpropanolamine exposure in C57BL/6J mice
Authors: Penzner Jeffery H. , Thompson Daria L. , Arth Cory , Fowler Jaclyn K. , Ary Alexis W. , Szumlinski Karen K.
Published: March 2008

Exposure to the once highly prevalent over‐the‐counter (OTC) sympathomimetic phenylpropanolamine (PPA; ±‐norephedrine) during pre‐adolescence alters the developmental trajectory of catecholamine and amino acid neurotransmitter systems in the nucleus accumbens (NAC) that culminate in a ‘pro‐addictive’ phenotype in adulthood. Thus, the present study sought to extend these earlier data by examining the long‐term consequences of repeated PPA treatment during adolescence upon the behavioral and neurochemical responses to cocaine. For this, C57BL/6J mice were pre‐treated with PPA (0–40 mg/kg) during postnatal days 35–44, and the capacity of cocaine (4 × 15 mg/kg) to elicit a conditioned place‐preference, as well as behavioral and neurochemical sensitization within the NAC, were then assessed in adulthood. While adolescent PPA exposure did not influence spontaneous locomotor activity or the motor responses to either acute or repeated cocaine (4 × 15 mg/kg), PPA pre‐exposure dose‐dependently reduced the expression of a conditioned place‐preference. As observed previously for juvenile PPA treatment, adolescent PPA administration blunted the dopamine and norepinephrine response to acute cocaine, prevented the development of catecholamine sensitization but did not influence cocaine‐induced elevations in serotonin. However, unlike juvenile PPA treatment, adolescent PPA also prevented the development of glutamate sensitization within the NAC. These data provide evidence that adolescent exposure to a formerly prevalent OTC sympathomimetic produces protracted effects upon cocaine‐induced changes in NAC glutamate transmission that may reduce vulnerability to cocaine addiction in later life and further the hypothesis that early exposure to sympathomimetic drugs may be an environmental factor contributing to the etiology of addiction.
Associations of adipokines with asthma, rhinoconjunctivitis, and eczema in German schoolchildren
Authors: Nagel Gabriele , Koenig Wolfgang , Rapp Kilian , Wabitsch Martin , Zoellner Iris , Weiland Stephan K.
Published: March 2008

There is growing evidence for an association between obesity and asthma, but little is known about the underlying mechanisms. We hypothesized that high plasma leptin and low plasma adiponectin concentrations might be related to asthma and allergies in children. Plasma leptin and adiponectin concentrations were measured in a cross‐sectional study involving 462 children aged 10 years. Information on disease symptoms and diagnosis was collected by parental questioning. Multivariate linear and logistic regression models were used to assess the association between biomarkers and disease. High leptin levels were associated with increased lifetime prevalence of asthma [odds ratio (OR): 3.76; 95% confidence interval (CI): 1.42–9.92]. The relationship was particularly strong for non‐atopic asthma (OR: 5.51; 95% CI: 1.99–17.51). No associations were observed between plasma leptin levels and hay fever, and rhinoconjunctivitis. Low adiponectin levels were associated with increased prevalence of both symptoms of atopic dermatitis (OR: 3.23; 95% CI: 1.28–7.76) and ever‐diagnosed eczema (OR: 2.35; 95% CI: 1.13–4.89). In girls and non‐atopic children, stronger associations for both leptin and adiponectin levels with asthma than in boys and atopic children were observed. These results suggest that adipokines may contribute to increased asthma and allergy risk in obese subjects. Stronger associations among girls with non‐atopic asthma may indicate diverse pathological mechanisms.
Survival and recovery of apheresis platelets stored in a polyolefin container with high oxygen permeability
Authors: Ezuki S. , Kanno T. , Ohto H. , Herschel L. , Ito T. , Kawabata K. , Seino O. , Ikeda K. , Nollet K. E.
Published: March 2008

Background and Objectives  Oxygen permeability is important in platelet storage media. We compared a new polyolefin container with enhanced oxygen permeability (PO‐80; Kawasumi, Tokyo, Japan) to a widely used alternative (PL2410; Baxter Healthcare, Deerfield, IL, USA).

Materials and Methods  In vitro characteristics of paired platelet concentrates (PCs; mean 4·2 × 1011/250 ml plasma/bag) stored in PO‐80 or PL2410 were assessed through 9 days of storage. In vivo recovery and survival of 7‐day‐old autologous PCs were assessed according to the Murphy method.

Results  Laboratory assessment of platelet quality favoured PO‐80 during 9 days of storage with statistically significant differences in glucose consumption (2·75 vs. 4·93 mmol/1012/24 h in the interval 120–168 h), lactate generation (4·37 vs. 8·11 mmol/1012/24 h in the interval 120–168 h), pressure of oxygen (pO2) (59·3 vs. 38·1 mmHg at day 1), and (14·7 vs. 13·4 mmol/l at day 1). Statistically significant differences were not seen in aggregation, hypotonic shock response or pH. In vivo assessment of autologous platelets stored 7 days in the PO‐80 container revealed that recovery was 82·1% and survival was 81·0% of fresh control. Seven‐day stored PCs in PO‐80 were shown in vivo to be non‐inferior to fresh platelets, with upper confidence limits (UCL95) in recovery and survival of stored PCs below the maximum acceptable difference (MAD); 15·3% UCL95 < 20·4% MAD and 2·1 days UCL95 < 2·1 days MAD.

Conclusions  The in vitro characteristics of PCs stored in a highly oxygen‐permeable container were stable at least 7 days. The in vivo study supports the suitability of PO‐80 for 7‐day platelet storage.
Root Distribution of Drought‐Resistant Peanut Genotypes in Response to Drought
Authors: Songsri P. , Jogloy S. , Vorasoot N. , Akkasaeng C. , Patanothai A. , Holbrook C. C.
Published: March 2008

The ability of a plant to modify its root distribution to exploit deeper stored soil water may be an important mechanism to avoid drought. This study aimed at assessing root distributions, variations in root length density (RLD) and percentage of root distribution, and the relevance of root traits for yield of drought‐resistant peanut genotypes under different available soil water levels. The experiment was conducted in the dry season during the years 2003/04 and 2004/05. Eleven peanut genotypes (ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308, ICGV 98324, ICGV 98330, ICGV 98348, ICGV 98353, Tainan 9, KK 60‐3 and Tifton‐8) and three soil moisture levels [field capacity (FC), 2/3 available soil water (AW) and 1/3 AW] were laid out in a split‐plot design with four replications. Roots were sampled by a core sampler at 37, 67 and 97 days after sowing (DAS). Root length was determined by a scanner and the WINRHIZO Pro 2004a software. RLD was calculated as the ratio of root length (cm) and soil volume (cm3). Graphical illustration of root distribution was constructed by merging RLD in the first and second soil layers (0–40 cm) as upper roots and pooling RLD at the third, fourth and fifth layers (40–100 cm) as lower roots. Pod yield, biomass and harvest index (HI) were recorded at harvest. A drought tolerance index (DTI) was calculated for each parameter as the ratio of the parameter under stress treatment to that under well‐watered conditions. Variations in RLD in 40 to 100 cm layer (RLD40 to 100 cm) were found under well‐watered conditions, and the peanut genotypes could be readily identified as high, intermediate and low for this trait. Changes in RLD in the 40 to 100 cm soil layer were found at 2/3 AW and were more evident at 1/3 AW. ICGV 98300, ICGV 98303, ICGV 98305, ICGV 98308 and KK 60‐3 were classified as drought responsive as they increased RLD in the deeper subsoil level in response to drought. In general, RLD under drought conditions was not related to biomass production. The ability to maintain the percentage of RLD (DTI for %RLD) was related to pod yield, DTI for pod yield and DTI for HI. ICGV 98300, ICGV 98303, ICGV 98305 exhibited high DTI (RLD40 to 100 cm) which may explain their high pod yield, DTI (PY) and DTI (HI). Based on these observations we classified them as drought‐avoiding genotypes.
Chlorophyll Stability is an Indicator of Drought Tolerance in Peanut
Authors: Arunyanark A. , Jogloy S. , Akkasaeng C. , Vorasoot N. , Kesmala T. , Nageswara Rao R. C. , Wright G. C. , Patanothai A.
Published: March 2008

Chlorophyll stability during drought might be a promising criterion for selection for drought resistance in peanut. The study describes two field trials conducted at Khon Kaen University, Thailand which investigate genotype × drought interactions in a wide range of peanut germplasm in general and assess the relationship between chlorophyll stability and genotypic performance in particular, under drought. Two field experiments (during 2003/2004 and 2004/2005 dry seasons) were conducted in a split plot design with three water regimes [field capacity, 2/3 available water (AW) and 1/3 AW] as main, and 12 peanut genotypes as subtreatments, replicated four times. Observations on total dry matter (TDM), chlorophyll density (ChlD) (chlorophyll content per unit leaf area), chlorophyll content (chlorophyll content per plant) and SPAD chlorophyll meter readings (SCMR) were recorded at 30, 60 and 90 days after emergence. Transpiration (T) and transpiration efficiency (TE) were computed using the data on amount of water input and TDM. Drought stress significantly reduced TDM, T and chlorophyll content across genotypes but significantly increased TE and ChlD in peanut. However, there were significant differences among genotypes for TE and chlorophyll parameters. The genotype × drought interaction effects for chlorophyll characters (content and density) were not significant suggesting a strong genetic effect. The correlation coefficients between TDM and chlorophyll content (r = 0.51, P = 0.01 to r = 0.91, P = 0.01) and between TE and ChlD (r = 0.46, P = 0.05 to r = 0.77, P = 0.01) were positive and significant. These findings suggest that chlorophyll parameters are strongly linked with drought tolerance in peanut. There were highly significant and positive relationships between ChlD and SCMR (r = 0.67, P = 0.01 to r = 0.93, P = 0.01), between SCMR and TE (r = 0.41, P = 0.05 to r = 0.80, P = 0.01) suggesting that SCMR could be used as a tool for rapid assessment of relative chlorophyll status in peanut genotypes as well as for the indirect selection of drought tolerance in peanut.
Angiotensin II receptor blocker inhibits tumour necrosis factor‐alpha‐induced cell damage in human renal proximal tubular epithelial cells
Authors: KAGAWA TORU , TAKAO TOSHIHIRO , HORINO TARO , MATSUMOTO REIKO , INOUE KOUSUKE , MORITA TATSUHITO , HASHIMOTO KOZO
Published: March 2008

Aim:  We investigated the effect of angiotensin II (AII) type 1 (AT1) and angiotensin II type 2 (AT2) receptor blockers on tumour necrosis factor alpha (TNF‐α)‐induced cell damage in human renal proximal tubular epithelial cells (RPTEC).

Methods:  The lactate dehydrogenase (LDH) and N‐acetyl‐beta‐glucosaminidase (NAG) release into the medium after TNF‐α treatment in RPTEC were determined using modified commercial procedures. In addition, the levels of caspase 3/7 activity in RPTEC were measured after TNF‐α treatment with ΑΤ1 or AT2 receptor blockers. Finally we investigated the change of p22phox protein levels after TNF‐α with ΑΤ1 or AT2 receptor blockers in RPTEC.

Results:  Tumour necrosis factor alpha (10−8 mol/L) significantly increased LDH and NAG release into the medium from RPTEC. ΑΤ1 receptor blockers, olmesartan and valsartan (10−9−10−6 mol/L) showed a significant reduction on TNF‐α‐induced LDH and NAG release in RPTEC. AT2 receptor blocker, PD123319 (10−7−10−5 mol/L) also decreased TNF‐α‐induced LDH and NAG release in RPTEC. Blockade of both ΑΤ1 and AT2 receptor indicated additional reduction on TNF‐α‐induced LDH and NAG release. TNF‐α (10−8 mol/L) treatment showed small but significant increases of caspase 3/7 activity in RPTEC, and AT1 and AT2 receptor blockers (10−8 mol/L) comparably decreased TNF‐α‐induced caspase 3/7 activity. Significant increases of p22phox protein levels were observed in TNF‐α‐treated group in RPTEC. However, only ΑΤ1 (10−8 mol/L) but not AT2 (10−5 mol/L) receptor blocker significantly decreased TNF‐α‐induced p22phox protein levels.

Conclusion:  The present study demonstrates that TNF‐α induces renal tubular cell damage in RPTEC and AT1/AT2 receptor blockers showed cytoprotective effects probably via at least partly different mechanism.
Endothelial nitric oxide synthase polymorphisms are associated with hypertension and cardiovascular disease in renal transplantation
Authors: BHANDARY USWANATHAN V , TSE WAI , YANG BINGMEI , KNOWLES MARK R , DEMAINE ANDREW G
Published: March 2008

Aim:  Nitric oxide (NO), produced by the polymorphic endothelial nitric oxide synthase (NOS3), plays an important role in endothelial function. The aim was to determine the effect of NOS3 polymorphisms on hypertension and cardiovascular disease (CVD) in renal allograft recipients.

Methods:  Three polymorphisms of NOS3 were examined in 168 renal allograft recipients. A 27 base pair repeat sequence in intron 4 (NOS3 a/b), a single G→T substitution in exon 7 at nucleotide 894 and a T‐786C substitution in the promoter region were studied.

Results:  Significant differences in the frequencies of the 894T and −786C alleles between allograft recipients and controls (n = 141) were demonstrated (894T: 40.5% vs 30.1%, P < 0.01; −786C: 45.2% vs 34.4%, P < 0.01). There was a significant excess of both the 894T and −786C alleles in hypertensive allograft recipients compared with normotensive allograft recipients and controls (894T: 41.7%, 35.7% and 30.1%, respectively, P < 0.025; −786C: 47.4%, 37.1% and 34.4%, respectively, P < 0.01), and in allograft recipients with CVD compared with those without CVD and controls (894T: 47.2%, 38.6% and 30.1%, respectively, P < 0.025; −786C: 54.2%, 42.8% and 34.4%, respectively, P < 0.01).

Conclusion:  The 894T and −786C alleles of the NOS3 gene were significantly associated with both hypertension and CVD in renal allograft recipients.
Extracellular signal‐regulated kinase‐dependent interstitial macrophage proliferation in the obstructed mouse kidney
Authors: HAN YINGJIE , MASAKI TAKAO , HURST LYNETTE A , IKEZUMI YOHEI , TRZASKOS JAMES M , ATKINS ROBERT C , NIKOLIC‐PATERSON DAVID J
Published: March 2008

Aim:  A number of growth factors have been shown to induce proliferation of renal cell types in animal models of kidney disease. In vitro studies suggest that many such growth factors induce renal cell proliferation through the extracellular signal‐regulated kinase (ERK) pathway. The aim of this study was to determine the functional role of ERK signalling in cell proliferation in the obstructed kidney.

Methods:  Unilateral ureteric obstruction was induced in C57BL/6J mice which then received an ERK inhibitor drug (U0126 100 mg/kg t.i.d.), vehicle (DMSO) or no treatment, starting at day 2 after unilateral ureteric obstruction surgery and continuing until animals were killed on day 5. Cell proliferation was assessed by uptake of bromodeoxyuridine (BrdU).

Results:  In normal mice, phosphorylation (activation) of ERK (p‐ERK) was restricted to collecting ducts. Western blotting identified a marked increase in p‐ERK in the obstructed kidney in the no‐treatment and vehicle‐treated groups. Immunostaining showed strong p‐ERK staining in many tubules and in interstitial cells. U0126 treatment inhibited ERK phosphorylation as assessed by western blot and immunostaining. The number of BrdU+ cortical tubular cells was reduced by vehicle treatment but was not further changed by U0126 treatment. In contrast, interstitial cell proliferation in the obstructed kidney was unaltered by vehicle treatment, but this was significantly inhibited by U0126. This was associated with a reduction in interstitial macrophage accumulation, but no effect was seen upon interstitial accumulation of α‐SMA+ myofibroblasts. Renal fibrosis, as assessed by collagen deposition, was unaffected by U0126 or vehicle treatment.

Conclusion:  These studies show that accumulation of interstitial macrophages in the obstructed kidney is, in part, dependent upon the ERK signalling pathway.
Omega‐3 fatty acid supplementation and total homocysteine levels in end‐stage renal disease patients
Authors: BEAVERS KRISTEN M. , BEAVERS DANIEL P. , BOWDEN RODNEY G. , WILSON RONALD L. , GENTILE MINDY
Published: March 2008

Aim:  Elevated total homocysteine (tHcy) levels are commonplace among end‐stage renal disease (ESRD) patients increasing risk for poor cardiovascular outcomes. Specifically, when plasma levels become significantly elevated, tHcy levels appear to contribute to vascular damage and premature atherosclerosis. The purpose of this study was to examine the effect of an over‐the‐counter omega‐3 (n‐3) fatty acid supplementation on tHcy levels in ESRD patients undergoing chronic haemodialysis.

Methods:  The present study was conducted using a double‐blind, permuted‐randomized and placebo‐controlled experimental protocol. ESRD patients were followed prospectively while supplementing n‐3 or corn oil (n‐6) prospectively for 6 months.

Patients:  Sixty‐nine patients were recruited that had previously demonstrated compliance with dialysis and medication. Following a 12 h fast, participants donated 12 mL of blood for analysis of tHcy at baseline and at 6 months.

Results:  The results of this study using regression models revealed no differences in age and gender regarding homocysteine levels at the post‐test with P‐values of 0.6818, 0.6709 and 0.3331 for each regression model. The study findings also revealed that daily administration of 6 g of n‐3 fatty acids containing 160 mg of eicosapentaenic acid (0.96 g/day) and 100 mg of docosahexaenoic acid (0.6 g/day) had no effect on tHcy levels when compared with control.

Conclusion:  Potential reasons for this non‐significant result may be found in a dose–response relationship, advancement of disease progression in our sample population, or potentially the lack of a significant relationship between fish oil and tHcy. Future studies should address whether a dose–response relationship between n‐3 fatty acid supplementation and tHcy levels exists, and how stage of disease progression affects intervention success or failure.