bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variability and correlations in carnivore crania and dentition
Authors: MEIRI S. , DAYAN T. , SIMBERLOFF D. 
Published: May 2005

Summary

We analysed patterns of variability and correlations in skulls and teeth of a wide (>100 species; >17 000 specimens) sample of terrestrial carnivores.
Within species, larger craniodental components vary less than do smaller ones.
The higher variability of canines in comparison with lower carnassials probably reflects the low complexity of the former.
Among species, however, trait variation is not size‐related, suggesting that the higher intraspecific variability of small traits is not an artefact of measurement error.
Correlations between the carnassial teeth are higher in carnivores feeding mainly on vertebrates than in those that eat mostly invertebrates or fruit, suggesting that the degree of functional integration between these teeth is under differing selective pressures.
Correlations between the carnassials probably have a phylogenetic basis as well, with caniform carnivores having higher correlation coefficients than feliform ones.
A potential microevolutionary life‐history trade‐off in White‐Footed Mice (Peromyscus leucopus)
Authors: HEIDEMAN P. D. , RIGHTLER M. , SHARP K. 
Published: May 2005

SummaryReproductive costs can affect survival and future reproduction. In winter and in short photoperiods, some individuals within populations of temperate‐zone rodents inhibit reproduction and decrease food intake, while others do not.Two lines derived from a natural population of White‐Footed Mice and selected to maintain or inhibit reproduction in short photoperiod were tested for two potentially correlated responses to selection: changes in food intake and body mass. Mice were raised to age 70 days in short or long photoperiod, following which testis size, body mass and food intake were measured over a 2‐week period.In both lines and both photoperiods, there was an apparent response to selection in testis size and a correlated response to selection in food intake but not body mass. In both photoperiods, mice in the line selected for winter reproduction ate 50% more than mice in the line selected for winter reproductive inhibition. Mice in an unselected control line were intermediate for testis size and food intake.The increased food intake in a line of mice with a genetic tendency for winter reproduction suggests a potential cost of winter reproduction and a potential microevolutionary trade‐off related to this cost of reproduction.
Quality control workshops in standardization of sperm concentration and motility assessment in multicentre studies
Authors: TOFT GUNNAR , RIGNELL‐HYDBOM ANNA , TYRKIEL EWA , SHVETS MARYNA , GIWERCMAN ALEKSANDER 
Published: May 2005

SummarySemen quality has been reported to vary markedly between different regions. To properly assess the differences among countries a minimization of the variation among centres in the assessments of sperm quality is essential. We here report on the training and two subsequent follow‐up workshops on assessments of sperm concentration and motility. A total of 26 fresh ejaculates were analysed by four persons who were collecting these data in a multicentre study on sperm quality. In addition, two trained technicians from one of the laboratories analysed the samples. At the first training workshop, the median coefficient of variation among centres in sperm concentration was 27.7%, but decreased markedly to 17.0% at the second workshop and 8.1% (p = 0.048) at the third workshop. The CV for evaluation of the proportion of progressive motile sperm decreased less and not statistically significant from 16.5 to 14.1% and 11.0% (p = 0.94). At the third workshop there were no statistical significant differences among centres in assessments of sperm concentration or motility (p > 0.57). Furthermore the coefficient of variation in assessments of sperm concentration and motility among centres were at the same level as between two trained technicians (p > 0.72). This study indicates that training and subsequent follow‐up workshops can assure minimum variability among centres in assessments of sperm concentration and motility.
Is inhibin B involved in the toxic effect of lead on male reproduction?
Authors: MAHMOUD A. , KISS P. , VANHOORNE M. , DE BACQUER D. , COMHAIRE F. 
Published: May 2005

SummaryHuman studies indicate exposure to lead is associated with decreased sperm quality with modest, if any, effects on conventional reproductive endocrine profile. Inhibin B is a marker of Sertoli cell function and spermatogenesis. The present study evaluates possible effects of lead exposure on serum levels of inhibin B in a group of lead workers as compared with a non‐exposed group of hospital personnel. The study population included 68 healthy Belgian workers from a lead smelter (Hoboken, Belgium) and for comparison a control group of 91 hospital personnel (University Hospital Ghent, Belgium). Semen analysis and measurement of current blood lead levels and serum levels of inhibin B, follicle stimulating hormone (FSH) and estradiol (E2). Lead workers had significantly lower sperm concentration (35 vs. 51 million/mL) and higher serum inhibin B (259 vs. 177 pg/mL) as well as lead blood levels 30.9 vs. 3.4 μg/dL) compared with the hospital personnel (all p < 0.05). Serum FSH and E2 levels were similar in both groups. Overall, inhibin B levels correlated significantly positively with blood lead levels and sperm concentration while it was negatively correlated with serum FSH. In multiple regression analysis of data from all participants, blood lead and serum FSH (p < 0.0001 for both) followed by sperm count (p = 0.007) were selected as the only independent variables for inhibin B with an R‐adjusted coefficient of determination of 0.3714. The results of the present study suggest that the exposure of the cells of Sertoli to excessive amounts of lead results in inappropriate inhibin B overproduction that may be involved in the impairment of spermatogenesis.
Glutathione levels in patients with erectile dysfunction, with or without diabetes mellitus
Authors: TAGLIABUE M. , PINACH S. , DI BISCEGLIE C. , BROCATO L. , CASSADER M. , BERTAGNA A. , MANIERI C. , PESCARMONA G.P. 
Published: May 2005

SummaryThe reduced form of glutathione (GSH) is the most important cell antioxidant and is also an essential cofactor for nitric oxide (NO) synthase that synthesizes NO from l‐arginine. Reduced levels of GSH, due both to a hyperglycaemia‐induced increase of free radical production and to a decrease of NADPH levels [like in diabetes mellitus (DM)], can hamper the endothelial cell functions. This condition may play an important role in the aetiology of some clinical signs, like erectile dysfunction (ED). The aim of this study was to test the hypothesis that GSH concentration is reduced in patients with ED and type 2 diabetes mellitus. We studied 111 male patients with ED: 64 with diabetes (ED/DM) and 47 without diabetes (ED/wDM); 20 patients with diabetes but without ED (DM) and 26 male normal subjects as a control group (C). The GSH red blood cell concentration was significantly lower in ED than in C (X ± SD; 1782.12 ± 518.02 vs. 2269.20 ± 231.56 μmol/L, p < 0.001). In particular, GSH was significantly reduced in ED/DM vs. ED/wDM (1670.74 ± 437.68 vs. 1930.63 ± 581.01 μmol/L, p < 0.01). In DM, GSH was significantly lower than in C and significantly higher than in ED/DM (2084.20 ± 118.14 vs. 2269.20 ± 231.56 and vs. 1670.74 ± 437.68 μmol/L, p < 0.002 and p < 0.001 respectively). GSH showed a negative correlation with fasting glucose concentrations (r = −0.34, p < 0.01) and with the duration of DM (r = −0.25, p < 0.05). A GSH depletion can lead to a reduction of NO synthesis, thus impairing vasodilation in the corpora cavernosa.
Unusual germ cell organization in the seminiferous epithelium of a murid rodent from southern Asia, the greater bandicoot rat,Bandicota Indica
Authors: WORAWITTAYAWONG P. , LEIGH C. M. , COZENS G. , PEIRCE E. J. , SETCHELL B. P. , SRETARUGSA P. , DHARMARAJAN A. , BREED W. G. 
Published: May 2005

SummaryIn the greater bandicoot rat,Bandicota indica, of south‐east Asia, nine cell associations were documented in the testicular seminiferous epithelium. In about 10% of the tubule cross sections two or more cell associations occurred and, furthermore, some of the generations of germ cells within the cell associations were sometimes either out of phase, or missing, in the tubule cross sections. These features, together with the fact that this species has a highly pleiomorphic sperm head shape, are somewhat reminiscent of those of the seminiferous epithelium in humans and some other primates but not of common laboratory rodents. This species could thus be a good model for investigating irregular patterns of spermatogenesis in naturally occurring wild species of rodent.
Stroke and coronary heart disease in treated hypertension – a prospective cohort study over three decades
Authors: ALMGREN T. , PERSSON B. , WILHELMSEN L. , ROSENGREN A. , ANDERSSON O. K. 
Published: May 2005

Abstract.Objective. To compare cardiovascular mortality and morbidity in middle‐aged hypertensive men with initially nonhypertensive men derived from the same random population sample, and to study stroke morbidity in these men in relation to cardiovascular risk factors during 25–28 years of follow‐up.Design. Prospective, population‐based observational study in men where the main intervention effort was directed towards treatment of hypertension in a special outpatient clinic.Subjects and methods. A total of 754 hypertensive men aged 47–55 years at screening were compared with 6740 men with normal blood pressure. The hypertensive men got stepped care treatment with either beta‐blockers, thiazide diuretics, or combination treatment including vasodilating agents during the whole observational period. Data on cause‐specific mortality and morbidity, and all cause mortality were obtained from patient files and the national registers on mortality and hospital admissions respectively.Main outcome measures. Baseline and change of cardiovascular risk factors during the first 15 years of follow‐up and all cause mortality, and mortality and morbidity from stroke and coronary heart disease during 25–28 years.Results. Treated hypertensive men had their blood pressure reduced with 21/15 mmHg during the first 5 years of the study and mean blood pressure levels were then rather constant. A minor reduction of serum cholesterol was also observed and a significant reduction in the prevalence of smoking. Treated hypertensive men suffered a substantial increased incidence of cardiovascular complications that escalated during the latter course of the study. Their total incidence of stroke was doubled; they had 50% more myocardial infarctions (MIs); mortality from coronary heart disease was doubled and all cause mortality was increased by a third, compared with nonhypertensive. In multiple regression analysis the incidence of stroke was significantly related to smoking and diabetes at entry and in time‐dependent Cox's regression analysis it was significantly related only to smoking. There was no relationship observed between achieved systolic or diastolic blood pressure and the risk of stroke or MI nor was there any relationship between the change in blood pressure and such cardiovascular complications.Conclusion. In spite of a substantial reduction of their blood pressure, treated hypertensive middle‐aged men had a highly increased risk of stroke, MI and mortality from coronary heart disease compared with nonhypertensive men of similar age. The increased risk of cardiovascular complications escalated during the latter course of the study.
A randomized placebo‐controlled trial of an NMDA receptor antagonist in sleep‐disordered breathing
Authors: TORVALDSSON STEFAN , GROTE LUDGER , PEKER YÜKSEL , BASUN HANS , HEDNER JAN 
Published: May 2005

SummaryHypoxemia is a powerful stimulus of glutamate release in the central nervous system (CNS) and a hallmark phenomenon in sleep disordered breathing (SDB). Glutamate effects that include neuronal damage and apoptosis following hypoxemia and apnea following microinjections in animal models are in part mediated via postjunctional N‐methyl‐d‐aspartate (NMDA) receptors. This was a double blind, randomized, placebo‐controlled single dose cross‐over study of the NMDA receptor antagonist AR‐R15896AR in 15 male patients with moderate to severe SDB. Seven patients received 120 mg and eight patients received 350 mg AR‐R15896AR or corresponding placebo (given by 2 h infusion) starting half an hour before estimated sleep onset. AR‐R15896AR concentrations were in line with the predicting kinetic model. A standard polysomnographic montage was applied. Repeated plasma samples were obtained in nine patients for analysis of plasma glutamate. Glutamate concentration in plasma did not change overnight and was unrelated to severity of SDB. Overall AHI (apnea–hypopnea index; primary efficacy variable) or investigated oxygen saturation variables were not significantly changed after AR‐R15896AR at either dosage level. Side effects were mostly confined to the higher dose level and included vivid dreams, nightmares as well as in two cases mild hallucinations. The previously postulated role of glutamate in SDB could not be confirmed after AR‐R15896AR induced NMDA‐receptor blockade.
Influence of HLA antigens and OSAS in childhood: a preliminary report*
Authors: BRUNETTI LUIGIA , FRANCAVILLA RUGGIERO , LEONARDO MINIELLO VITO , LEONE MADDALENA , RANA MICHELE , COLAZZO DAMIANO , LOGRILLO PAOLO , FAVOINO BIAGIO , ARMENIO LUCIO 
Published: May 2005

SummarySeveral studies have emphasized the role of familial factors and familial aggregation in increasing susceptibility to obstructive sleep apnea syndrome (OSAS); the aim of the present study was to investigate the possible influence of human leukocyte antigen (HLA) in the development of sleep disordered breathing and OSAS of children. Between January 2000 and January 2003, all the 370 children [193 males; median age: 5.2 years (range: 1–12 years)] with sleep disordered breathing referred to our Center were screened by a 41‐item multiple‐choice questionnaire. All habitual snores children underwent a polisomnographic evaluation, and those with an apnea/hypopnea index >3 were diagnosed as having OSAS. All children with OSAS or primary snoring were HLA typied for class I and II. According to nocturnal polygraphic monitoring study, 41 patients were diagnosed as having OSAS and 32 as primary snoring. Patients in the two diagnostic groups were homogeneous for demographic and clinical characteristics. HLA‐B65 was found to be significantly more expressed in children with sleep disordered breathing as compared with controls (10.5% versus 3.61; Pypc < 0.04) while no difference was found for the other tested antigens. A logistic regression analysis found cough (P < 0.02) and persistent wheeze (P < 0.008) the sole risk factors for OSAS development. Our preliminary data suggest that HLA does not play a key role in the pathogenesis of OSAS, however more studies are needed to clarify this issue.
Regional differences of the sleep electroencephalogram in adolescents
Authors: JENNI OSKAR G. , VAN REEN ELIZA , CARSKADON MARY A. 
Published: May 2005

SummaryThe sleep electroencephalogram (EEG) was recorded from anterior (Fz/Cz) and posterior (Pz/Oz) bipolar derivations in two developmental groups: 20 pre‐ or early pubertal (Tanner 1/2, mean age 11.4 ± 1.1 years, 11 boys) and 20 late pubertal or mature adolescents (Tanner 4/5, 14.1 ± 1.3 years, 8 boys). A sleep‐state independent reduction of EEG power over almost the entire frequency range was present in Tanner 4/5 compared with Tanner 1/2 adolescents. Spectral characteristics of the sleep EEG yielded state‐ and frequency‐dependent regional differences that were similar in both developmental groups. Anterior predominance of power in delta and sigma ranges occurred in non‐rapid eye movement sleep. Rapid eye movement sleep EEG power was greater in low delta, alpha, and sigma ranges for the posterior derivation and in theta and beta ranges for the anterior derivation. The decay rate of the sleep homeostatic process – reflected by the exponential decline of the 2‐Hz EEG power band across the sleep episode – did not differ for derivations or groups. These results indicate that the nocturnal dynamics of sleep homeostasis are independent of derivation and remain stable across puberty.
Odds, prevalence and predictors of sleep problems in school‐age normal children
Authors: SPRUYT KAREN , O'BRIEN LOUISE M. , CLUYDTS RAYMOND , VERLEYE GINO BENJAMIN , FERRI RAFFAELE 
Published: May 2005

SummaryThe objectives of the study were to describe the prevalence, odds, and predictors of 36 paediatric sleep behaviours and describe their coexistence in a school‐age normal population. The design was community‐based questionnaire survey of sleep–wake patterns, sleep environment, and 36 sleep behaviours indicative of six sleep disorder‐subscales using the Health‐Behaviour Questionnaire. A caregivers’ report of 3045 children aged 6–13 years in Belgium constituted the participants. Prevalence of each sleep behaviour was calculated. Log‐linear modelling within and between the sleep disorder‐subscales was used to screen for coexistence. The effect size of selected night‐time parameters to the likelihood of sleep behaviours and disorder‐subscale was expressed as odds ratios via logit regression analysis. Significant differences in sleep–wake patterns were found between weekday and weekend. Ranking by odds showed that: (1) sleep problems such as ‘tired when waking up’, ’repetitive limb movements’, ‘going to bed reluctantly’, and ‘sleep paralysis’ and; (2) the disorder‐subscale ‘excessive somnolence’ are common in children. Coexistences within and between disorder‐subscales of sleep problems are evident in a school‐age, normal population. These results suggest that disorders of excessive somnolence (DES) are highly prevalent in a non‐clinical sample of school‐age children. Furthermore, sleep‐onset latency and a noisy, not well‐darkened room are predictive towards the odds for exhibiting sleep problems and disorders. It is advocated that more information on the importance of good sleep–wake hygiene should reach parents and children.
Invasion genetics of the Eurasian spiny waterflea: evidence for bottlenecks and gene flow using microsatellites
Authors: COLAUTTI ROBERT I. , MANCA MARINA , VILJANEN MARKKU , KETELAARS HENK A. M. , BÜRGI HANSRUDOLF , MACISAAC HUGH J. , HEATH DANIEL D. 
Published: May 2005

AbstractThe Eurasian spiny waterflea (Bythotrephes longimanus) is a predacious zooplankter that has increased its range in Europe and is rapidly invading inland water‐bodies throughout North America's Great Lakes region. To examine the genetics of these invasions, we isolated five microsatellite DNA loci with between 5 and 19 alleles per locus. We sampled three populations where B. longimanus has been historically present (Switzerland, Italy, and Finland) as well as an introduced European population (the Netherlands) and three North American populations (Lakes Erie, Superior, Shebandowan). Consistent with a bottleneck during colonization (i.e. founder effect), average heterozygosities of the four European populations ranged from 0.310 to 0.599, and were higher than that of three North American populations (0.151–0.220). Pairwise FST estimates among North American populations (0.002–0.063) were not significantly different from zero and were much lower than among European populations (0.208–0.474). This is consistent with a scenario of high gene flow among North American populations relative to that of European ones. Contrary to an invasion bottleneck, however, Erie and Superior populations contained similar numbers of rare alleles as European populations. Assignment tests identified several migrant genotypes in all introduced populations (the Netherlands, Erie, Superior, Shebandowan), but rarely in native ones (Switzerland, Italy and Finland). A large number of genotypes from North America were assigned to our Italian population suggesting a second, previously unidentified, invasion source somewhere in the region of northern Italy. Together, our results support an invasion bottleneck for North American populations that has been largely offset by gene flow from multiple native sources, as well as gene flow among introduced populations.
Genetic evidence of local adaptation of wheat yellow rust (Puccinia striiformis f. sp. tritici) within France
Authors: ENJALBERT J. , DUAN X. , LECONTE M. , HOVMØLLER M. S. , DE VALLAVIEILLE‐POPE C. 
Published: May 2005

Abstract Puccinia striiformis f. sp. tritici (PST), a clonal basidiomycete causing yellow rust disease on wheat, has a long record of ‘overcoming’ cultivar resistance introduced by breeders. Despite the long dispersal capacity of its spores, the French population of PST presents a strong geographical structure, with the presence of a specific pathotype (array of avirulence genes) at high frequencies in the south of France. The genetic diversity underlying this differentiation was analysed by microsatellite and AFLP markers. A total of 213 French isolates belonging to 10 pathotypes collected over a 15‐year period were investigated. For each of the 12 microsatellites used, polymorphism resulted from a unique allelic variant associated to the south‐specific pathotype. This pathotype was characterized by 40 specific markers over the total of 63 polymorphims detected using 15 AFLP primer combinations. Phylogeographical analysis indicated a strictly clonal structure of the population, and a strong genomic divergence between the northern population and a south‐specific clone. Both virulence and molecular data show that the northern French population belongs to the northwestern European population, whereas the southern clone is most likely related to a Mediterranean population, the two subpopulations resulting from the ancient divergence of two clonal lineages. While the virulence complexity in the northern population may be explained by the successive introduction of corresponding resistance genes in cultivars, the maintenance of a simple virulence type in southern France, despite gene flow between the two populations, may be explained in terms of host cultivars repartition and local adaptation to specific host or climatic conditions.
Phosphatases modulate the bistable sporulation gene expression pattern in Bacillus subtilis
Authors: Veening Jan‐Willem , Hamoen Leendert W. , Kuipers Oscar P. 
Published: May 2005

SummarySpore formation in the Gram‐positive bacterium Bacillus subtilis is a last resort adaptive response to starvation. To initiate sporulation, the key regulator in this process, Spo0A, needs to be activated by the so‐called phosphorelay. Within a sporulating culture of B. subtilis, some cells initiate this developmental program, while other cells do not. Therefore, initiation of sporulation appears to be a regulatory process with a bistable outcome. Using a single cell analytical approach, we show that the autostimulatory loop of spo0A is responsible for generating a bistable response resulting in phenotypic variation within the sporulating culture. It is demonstrated that the main function of RapA, a phosphorelay phosphatase, is to maintain the bistable sporulation gene expression. As rapA expression is quorum regulated, it follows that quorum sensing influences sporulation bistability. Deletion of spo0E, a phosphatase directly acting on Spo0A∼P, resulted in abolishment of the bistable expression pattern. Artificial induction of a heterologous Rap phosphatase restored heterogeneity in a rapA or spo0E mutant. These results demonstrate that with external phosphatases, B. subtilis can use the phosphorelay as a tuner to modulate the bistable outcome of the sporulating culture. This shows that B. subtilis employs multiple pathways to maintain the bistable nature of a sporulating culture, stressing the physiological importance of this phenomenon.