bluuebunny/crossref_metadata_2025_split huggingface dataset:
Obesity in adults with Down syndrome: a case–control study
Authors: Melville C. A. , Cooper S.‐A. , McGrother C. W. , Thorp C. F. , Collacott R. 
Published: January 2005

AbstractBackground  Obesity has a negative impact upon mortality and morbidity. Studies report that obesity is more prevalent in individuals with Down syndrome than individuals with intellectual disabilities (ID) not associated with Down syndrome. However, there have been no studies using a methodology of matched comparison groups and findings from previous studies are contradictory.Methods  A detailed method was used to identify all adults with ID in Leicestershire. Individuals were invited to participate in a medical examination – that included measurement of their height and weight, from which body mass index (BMI) was calculated. For each person with Down syndrome, an individual matched for gender, age and accommodation type was identified, from the Leicestershire ID database.Results  The data for 247 matched pairs is reported. Women with Down syndrome had lower mean height and weight, but greater mean BMI than the matched pairs. Men with Down syndrome had a lower mean height and weight but there was no statistical difference in BMI compared to the matched pairs. Using World Health Organization categories of BMI, women with Down syndrome were more likely to be overweight or obese than their matched pairs (odds ratio = 2.17). Men with Down syndrome were more likely to be in the overweight category than their matched pairs but were less likely to be obese (odds ratio = 0.85).Conclusions  This study demonstrates that, compared to a matched sample, there is a greater prevalence of obesity amongst women with Down syndrome but not men. As the impact on the health of people with Down syndrome of being overweight or obese is uncertain, this is an area that requires further study.
Underweight, obesity and exercise among adults with intellectual disabilities in supported accommodation in Northern England
Authors: Emerson E. 
Published: January 2005

AbstractBackground  Significant deviation from normal weight (obesity and underweight) and lack of physical exercise have been identified as three of the most significant global behavioural risks to health.Methods  Body mass index (BMI) and levels of physical activity were measured in a sample of 1542 adults with intellectual disabilities (ID) receiving supported accommodation in nine geographical localities in Northern England. Comparative population data were extracted from the Health Survey for England 1998 and 2001.Results  Men and women with ID living in supported accommodation are at increased risk of being significantly underweight and physically inactive. Women with ID living in supported accommodation are at increased risk of obesity. Within the population of people with ID living in supported accommodation increased behavioural health risks are associated with gender, severity of ID, age and location.Conclusion  Significant deviation from normal weight and lack of physical exercise are significant behavioural risks to health among people with ID.
The evolutionary forces maintaining a wild polymorphism of Littorina saxatilis: model selection by computer simulations
Authors: Pérez‐Figueroa A. , Cruz F. , Carvajal‐Rodríguez A. , Rolán‐Alvarez E. , Caballero A. 
Published: January 2005

AbstractTwo rocky shore ecotypes of Littorina saxatilis from north‐west Spain live at different shore levels and habitats and have developed an incomplete reproductive isolation through size assortative mating. The system is regarded as an example of sympatric ecological speciation. Several experiments have indicated that different evolutionary forces (migration, assortative mating and habitat‐dependent selection) play a role in maintaining the polymorphism. However, an assessment of the combined contributions of these forces supporting the observed pattern in the wild is absent. A model selection procedure using computer simulations was used to investigate the contribution of the different evolutionary forces towards the maintenance of the polymorphism. The agreement between alternative models and experimental estimates for a number of parameters was quantified by a least square method. The results of the analysis show that the fittest evolutionary model for the observed polymorphism is characterized by a high gene flow, intermediate‐high reproductive isolation between ecotypes, and a moderate to strong selection against the nonresident ecotypes on each shore level. In addition, a substantial number of additive loci contributing to the selected trait and a narrow hybrid definition with respect to the phenotype are scenarios that better explain the polymorphism, whereas the ecotype fitnesses at the mid‐shore, the level of phenotypic plasticity, and environmental effects are not key parameters.
Nonantagonistic interactions between the sexes revealed by the ecological consequences of reproductive traits
Authors: Lacey Knowles L. , Brodie Hernandez B. , Markow T. A. 
Published: January 2005

AbstractIn addition to the obvious role reproductive traits play in mating‐system evolution, reproductive characters can also have critical ecological or life history consequences. In this study we examine the ecological consequences of mating for female cactophilic Drosophila to test different hypotheses about the processes driving divergence in reproductive characters. Comparisons between intra‐ and interpopulation matings suggest that population differences in mating benefits, namely increased desiccation resistance in mated females, is not solely attributable to either a male or female‐specific reproductive trait. Instead, the results indicate that increased desiccation resistance is a product of a male–female postmating–prezygotic interactions. The results underscore that postmating–prezygotic interactions can serve as an arena for the evolution of male characters that confer substantial benefits to females, not just costs arising from sexual conflict. Variation in the relative benefits conferred by mating between intra‐ and interpopulation matings also suggests that the relationship between speciation and divergence in reproductive characters via male–female interaction will be difficult to predict.
Environmental variation influences the magnitude of inbreeding depression in Cucurbita pepo ssp. texana (Cucurbitaceae)
Authors: Nelson Hayes C. , Winsor James A. , Stephenson Andrew G. 
Published: January 2005

AbstractWe grew inbred and outcrossed Cucurbita pepo ssp. texana plants and measured inbreeding depression for several male and female fitness traits 4 years in a row in adjacent fields at the same field station under the same cultivation conditions. We found that the magnitude of inbreeding depression varied from 0.16 to 0.53 from year to year and that those traits which were most affected tended to vary with year. We also grew inbred and outcrossed C. pepo ssp. texana plants in two adjacent fields differing only in the presence of nitrogen fertilizer to examine the effect of nutrient limitation as a form of environmental stress on the magnitude of inbreeding depression. We found that inbreeding depression was more severe in the unfertilized field. Overall, this study illustrates the notion that any estimate of inbreeding depression represents a single point in a cluster of possible estimates that can vary (often dramatically) with growing conditions.
Spatial and temporal patterns of parthenogenesis and parasitism in the freshwater snail Melanoides tuberculata
Authors: Ben‐Ami F. , Heller J. 
Published: January 2005

AbstractThe Red Queen hypothesis predicts that sex should be more common in populations heavily infested with parasites, than in those without. This hypothesis was investigated in the aquatic snail Melanoides tuberculata, in which both sexual and parthenogenetic individuals exist in natural populations, and some populations are heavily infested by trematodes. The presence of fertile males and the higher genetic diversity of bisexual populations are indicative of sexual reproduction. We compared sites in 1990, 1999, and 2001, and we looked for a positive correlation between male and parasite frequencies. Male frequency was not correlated with the frequency of individuals infected by trematodes. This lack of correlation was reconfirmed in a retrospective power analysis. In a period of 9 years, male frequencies decreased but infection levels increased. These results do not support the Red Queen hypothesis. In samples with high male frequency the number of embryos was low, perhaps indicating that males may have a negative effect on embryo numbers. This effect of males on fitness could perhaps suggest that the cost of sex is fewer embryos. The reduction in embryo numbers may also represent a trade‐off between mating and egg production costs.
Pitfalls in experiments testing predictions from sperm competition theory
Authors: Engqvist L. , Reinhold K. 
Published: January 2005

AbstractAs females of many species mate with more than one male, ejaculates often face competition from the sperm of other males. In recent years, numerous papers have been published on theoretical predictions of evolutionary, behavioural and physiological responses to variation in the strength of sperm competition (SC). These theoretical predictions have also been extensively tested. However, although predictions from SC theory are relatively straightforward, extra caution has to be paid in the design of experiments testing them. One difficulty is for example to disentangle immediate and mean SC risk and intensity. Without carefully designed experiments, it is also very easy to simultaneously increase SC risk and the probability of intense SC – a situation for which we currently have no clear predictions, as the theoretical models to date only assume variation in either SC risk or intensity. In this paper, we discuss these and some other pitfalls related to manipulations of SC risk and intensity and suggest how to avoid them.
Population differentiation and hybrid success inCampanula americana: geography and genome size
Authors: Galloway L. F. , Etterson J. R. 
Published: January 2005

AbstractPopulations within a species may diverge through genetic drift and natural selection. Few studies report on population differentiation in autopolyploids where multiple gene copies and the ratio of cytoplasmic to nuclear genes differ from diploids and may influence divergence. In autotetraploidCampanula americanawe created hybrids between populations that differed in geographic proximity and genome size. Differences in genome size (up to 6.5%) did not influence hybrid performance. In contrast, hybrid performance was strongly influenced by population proximity. F1 hybrids between distant populations performed poorly relative to their parents while hybrids between proximate populations outperformed their parents. Outbreeding depression was strongest for juvenile traits. The expression of outbreeding depression often differed between reciprocal hybrids indicating interactions between nuclear and cytoplasmic genes contribute to population differentiation. Because plants were grown under greenhouse conditions, the outbreeding depression was likely due to genetic (underdominance or loss of additive‐by‐additive epistasis) rather than ecological factors.
Covariation between brain size and immunity in birds: implications for brain size evolution
Authors: Møller A. P. , Erritzøe J. , Garamszegi L. Z. 
Published: January 2005

AbstractParasitism can negatively affect learning and cognition, setting the scene for coevolution between brain and immunity. Greater susceptibility to parasitism by males may impair their cognitive ability, and relatively greater male investment in immunity could compensate for greater susceptibility to parasites, in particular when males have a relatively large brain. We analysed covariation between relative size of immune defence organs and brain in juvenile and adult birds. The relative size of the bursa of Fabricius and the spleen in adults covaried positively with relative brain size across bird species. The relative size of these two immune defence organs covaried with sex differences in relative size of the brain, indicating that the relationship between immune defence and brain size was stronger for males. In contrast, liver and heart size or sexual size dimorphism in size did not covary with immune defence. Thus, species in which males have relatively large brains also have relatively large immune defence organs.
Granule cell number, cell death and cell proliferation in the dentate gyrus of wild‐living rodents
Authors: Amrein Irmgard , Slomianka Lutz , Lipp Hans‐Peter 
Published: January 2005

AbstractAdult neurogenesis in the dentate gyrus occurs at species‐specific levels. Wood mice (Apodemus flavicollis) show higher proliferation rates than laboratory mice and voles (Clethrionomys glareolus, Microtus subterraneus). We compare rates of cell death and proliferation and investigate if cell proliferation leads to the long‐term recruitment of granule cells. Granule and pyknotic cell numbers were estimated in wild‐living rodents in different age classes and compared with laboratory mice of mixed genetic background. All species differ significantly in their number of granule cells, except for the comparison of laboratory mice with European pine voles. Granule cell number is significantly higher in old bank voles and wood mice as compared to adults (23 and 37%, respectively). The number of pyknotic cells is highest in wood mice and lowest in laboratory mice. Across all species, the numbers of proliferating and pyknotic cells correlate. Despite differences in cell proliferation and cell death, the ratio of proliferating to pyknotic cells does not differ between adults of the wild‐living species, but in laboratory mice a significantly lower proportion of cells die compared with the other species. In addition, the ratio of proliferating to pyknotic cells was significantly higher in old wood mice than in adults. We conclude (i) that cell proliferation can lead to an increase in granule cell number in wild‐living rodents and (ii) that species‐ and age‐specific changes of the ratio between proliferating and pyknotic cells occur as deviations from a close correlation of these two numbers across all species and age groups.
Regulation of the lateral wall stiffness by acetylcholine and GABA in the outer hair cells of the guinea pig
Authors: Batta Tamás József , Panyi György , Szűcs Attila , Sziklai István 
Published: January 2005

AbstractAcetylcholine (ACh) and GABA, the main neurotransmitters of the efferent innervation of the outer hair cells (OHCs), are assumed to regulate the efficacy of the cochlear amplifier through a variety of mechanisms. The recently described stretch‐induced changes of the lateral wall stiffness (regulatory stiffness response) and the stretch‐induced slow cell motility of OHCs may be important regulatory mechanisms in this process [J.T. Batta et al. (2003) Eur. J. Physiol. 424, 328–336]. We found that ACh in cochleobasal OHCs significantly reduces the stiffness of the lateral wall but increases the regulatory stiffness response and stretch‐induced slow cell motility. Qualitatively similar cellular responses were evoked by GABA in cochleoapical OHCs. The effects of ACh could be inhibited by strychnine, the specific inhibitor of the α9 ACh receptors expressed in OHCs, whereas the effects of GABA could be blocked by bicuculline, a specific GABAA receptor antagonist. In the absence of extracellular Ca2+ the effects of ACh and GABA on the regulatory stiffness response were reduced, indicating the involvement of Ca2+ in the control of this process. Based on our results we suggest that efferent innervation protects the organ of Corti against high sound intensities and supports adaptation by modification of the micromechanical properties of OHCs. This could be governed by ACh and GABA indirectly, via the potentiation of stretch‐induced cell shortening in a Ca2+‐dependent manner, rather than by a direct stiffness regulation‐related mechanism.
Fractalkine reduces N‐methyl‐d‐aspartate‐induced calcium flux and apoptosis in human neurons through extracellular signal‐regulated kinase activation
Authors: Deiva Kumaran , Geeraerts Thomas , Salim Hassan , Leclerc Philippe , Héry Christiane , Hugel Bénédicte , Freyssinet Jean‐Marie , Tardieu Marc 
Published: January 2005

AbstractOur purpose was to investigate in human neurons the neuroprotective pathways induced by Fractalkine (FKN) against glutamate receptor‐induced excitotoxicity. CX3CR1 and FKN are expressed constitutively in the tested human embryonic primary neurons and SK‐N‐SH, a human neuroblastoma cell line. Microfluorometry assay demonstrated that CX3CR1 was functional in 44% of primary neurons and in 70% of SK‐N‐SH. Fractalkine induced ERK1/2 phosphorylation within 1 min and Akt phosphorylation after 10 min, and both phosphorylation decreased after 20 min. No p38 and SAPK/JNK activation was observed after FKN treatment. Application of FKN triggered a 53% reduction of the NMDA‐induced neuronal calcium influx, which was insensitive to pertussis toxin and LY294002 an inhibitor of Akt pathway, but abolished by PD98059, an ERK1/2 pathway inhibitor. Moreover, FKN significantly reduced neuronal NMDA‐induced apoptosis, which was pertussis toxin insensitive and abolished in presence of PD98059 and LY294002. In conclusion, FKN protected human neurons from NMDA‐mediated excitotoxicity in at least two ways with different kinetics: (i) an early ERK1/2 activation which reduced NMDA‐mediated calcium flux; and (ii), a late Akt activation associated with the previously induced ERK1/2 activation.
Low‐voltage‐activated A‐current controls the firing dynamics of mouse hypothalamic orexin neurons
Authors: Burdakov Denis , Alexopoulos Haris , Vincent Angela , Ashcroft Frances M. 
Published: January 2005

AbstractThe activity of hypothalamic neurons that release the neuropeptides orexin‐A and orexin‐B is essential for normal wakefulness. Orexin neurons fire spontaneously and are hyperpolarized and inhibited by physiological neuromodulators, but the intrinsic determinants of their electrical activity are poorly understood. We show that mouse orexin neurons coexpress orexin‐A and orexin‐B, and possess a low‐voltage‐activated A‐type K+ current (A‐current) likely to be composed of Kv4.3 subunits. The A‐current enhances the inhibitory influence of hyperpolarizing currents via two mechanisms: by delaying the resumption of spiking after hyperpolarization and by increasing the slope of the relation between the firing frequency and injected current. These results identify an important determinant of the firing dynamics of orexin neurons, and support the idea that the A‐current can control neuronal gain.
Clinical effects of scaling and root planing on untreated teeth
Authors: Pawlowski Adrian P. , Chen Allen , Hacker Beth M. , Mancl Lloyd A. , Page Roy C. , Roberts Frank A. 
Published: January 2005

AbstractObjective: The aim of this report is to examine whether scaling and root planing (SRP) in one area of the mouth may affect periodontal improvement in untreated areas in the same patient, possibly through systemic effects of treatment.Material and Methods: Twenty patients diagnosed with generalized aggressive periodontitis were randomized into treatment (n=11) and no treatment (n=9) groups. Within the treatment group, three quadrants were treated by SRP at week 0, 3, 12, and 24, while a single experimental quadrant remained untreated throughout the study. The outcome for all teeth was assessed using clinical parameters, subtraction radiography, and pathogenic bacteria levels in the subgingival flora over the 24‐week study period.Results: Compared with sites in no treatment patients, the treated sites in the treated patients showed a 1 mm decrease in probing depth (PD) (p<0.01) and a 0.5 mm increase in bone height (p<0.01) by 24 weeks. In untreated sites within treated subjects, however, PDs tended to improve (p=0.09) but at a reduced rate compared with treated sites. The levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis (Bacteroides forsythus) remained unchanged in untreated sites while levels of Prevetolla intermedia and Treponema denticola tended to decrease as compared with controls but did not reach significance.Conclusions: This study indicates that untreated sites in treated periodontitis patients show a trend towards clinical improvement and exhibit reductions in some but not all periodontopathic bacterial species tested.
Periodontitis, a marker of risk in pregnancy for preterm birth
Authors: Dörtbudak Orhun , Eberhardt Rita , Ulm Martin , Persson G. Rutger 
Published: January 2005

AbstractBackground: Why chronic periodontitis may induce an inflammatory response with premature pregnancy termination is unclear.Aims: (1) To assess if periodontitis predicts premature gestation; (2) to study amniotic fluid cytokines and periodontitis variables in early‐stage pregnancy.Material and Methods: A periodontal examination and collection of amniotic fluid was performed (weeks 15–20) of pregnancy in 36 women at risk for pregnancy complications. Amniotic fluid (bacteria), vaginal smears and intra‐oral plaque samples were studied. Cytokine levels in amniotic fluid were studied in relation to other study variables.Results: Periodontitis was diagnosed in 20% of normal and in 83% of preterm birth cases (p<0.01). Bacteria were never found in the amniotic fluids studied. Sub‐gingival plaque samples including bacteria in the orange and red complexes were found in 18% of full‐term 100% of preterm cases (p<0.001) and total colony‐forming units (CFUs) were higher in preterm birth (p<0.01). Amniotic levels of interleukin (IL)‐6 and prostaglandin‐E2 (PGE2) were higher in preterm cases (p<0.001). Amniotic IL‐6 (r=0.56, p<0.01) and PGE2 (r=0.50, p<0.01) cytokine levels were correlated with CFU from sub‐gingival plaque samples (r2=0.44).The odds ratio of preterm delivery and having periodontitis was 20.0 (95% confidence interval (CI): 2.0–201.7, p<0.01). The odds of >60 CFU in sub‐gingival plaque and preterm birth was 32.5:1 (95% CI: 3.0–335.1, p<01).Conclusions: Pregnant women with findings of elevated amniotic fluid levels of PGE2, IL‐6 and IL‐8 in the 15–20 weeks of pregnancy and with periodontitis are at high risk for premature birth. The implication of this is that periodontitis can induce a primary host response in the chorioamnion leading to preterm birth.