bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left atrioventricular plane displacement determined by echocardiography: a clinically useful, independent predictor of mortality in patients with stable coronary artery disease
Authors: Rydberg E. , Erhardt L. , Brand B. , Willenheimer R. 
Published: October 2003

Abstract. Rydberg E, Erhardt L, Brand B, Willenheimer R (Malmö University Hospital, University of Lund, Malmö, Sweden). Left atrioventricular plane displacement determined by echocardiography: a clinically useful, independent predictor of mortality in patients with stable coronary artery disease. J Intern Med 2003; 254: 479–485.Background. Echocardiographically determined left atrioventricular plane displacement (AVPD) is strongly related to prognosis in patients with chronic heart failure and in postmyocardial infarction patients. We aimed at exploring whether AVPD, unlike ejection fraction, is related to mortality in patients with stable coronary artery disease (CAD).Methods and results. Atrioventricular plane displacement was assessed by two dimensionally guided M‐mode echocardiography in the four and two chamber views, in 333 consecutive patients with stable CAD and an abnormal coronary angiogram. Patients were followed up for an average of 41 months. AVPD was lower in patients who died (n = 30, 9.0 %) compared with survivors (9.0 ± 2.2 vs. 11.5 ± 2.1 mm, P < 0.0001). Amongst patients with prior myocardial infarction (n = 184) AVPD was 8.7 ± 2.3 mm in those who died (n = 17) and 11.2 ± 2.3 mm in the survivors (P < 0.0001). In patients without prior myocardial infarction (n = 149), AVPD was 9.4 ± 2.1 (n = 13) and 11.8 ± 1.8 mm, respectively (P < 0.0001). Age, AVPD and four other echocardiographical variables correlated significantly with prognosis in univariate logistic regression analysis. In multiple logistic regression analysis only AVPD (P < 0.0001) correlated independently with mortality.Conclusion. Echocardiographically determined AVPDis a clinically useful, independent prognostic tool in patients with stable CAD. The presence of a documented previous myocardial infarction does not influence this observation.
White Adipose Tissue: Getting Nervous
Authors: Fliers E. , Kreier F. , Voshol P. J. , Havekes L. M. , Sauerwein H. P. , Kalsbeek A. , Buijs R. M. , Romijn J. A. 
Published: October 2003

AbstractNeuroendocrine research has altered the traditional perspective of white adipose tissue (WAT) as a passive store of triglycerides. In addition to fatty acids, WAT produces many hormones and can therefore be designated as a traditional endocrine gland actively participating in the integrative physiology of fuel and energy metabolism, eating behaviour and the regulation of hormone secretion and sensitivity. WAT is controlled by humoral factors, para‐ and intracrine factors and by neural regulation. Sympathetic nerve fibres innervate WAT and stimulate lipolysis, leading to the release of glycerol and free fatty acids. In addition, recent research in rats has clearly shown a functional parasympathetic innervation of WAT. There appears to be a distinct somatotopy within the parasympathetic nuclei: separate sets of autonomic neurones in the brain stem innervate either the visceral or the subcutaneous fat compartment. We therefore propose that the central nervous system (CNS) plays a major role in the hitherto unexplained regulation of body fat distribution. Parasympathectomy induces insulin resistance with respect to glucose and fatty acid uptake in the innervated fat depot and has selective effects on local hormone synthesis. Thus, the CNS is involved not only in the regulation of hormone production by WAT, but also in its hormone sensitivity. The developments in this research area are likely to increase our insights in the pathogenesis of metabolic disorders such as hypertriglyceridemia, diabetes mellitus type 2 and lipodystrophy syndromes.
The Effects of Neonatal Castration on the Subsequent Behavioural Response to Centrally Administered Arginine Vasopressin and the Expression of V1a Receptors in Adult Male Prairie Voles
Authors: Cushing B. S. , Okorie U. , Young L. J. 
Published: October 2003

AbstractCentrally administered arginine vasopressin induces the formation of partner preferences in male prairie voles (Microtus ochrogaster). The expression of many vasopressin‐regulated behaviours is testosterone dependent. In this study, we tested the hypothesis that early exposure to gonadal steroids are necessary to establish the typical response of adult male prairie voles to exogenous vasopressin, predicting that adult males which were castrated neonatally would not form partner preferences in response to centrally administered vasopressin. We also examined the effect of neonatal castration on the expression of vasopressin (V1a) receptors. Voles were castrated on the day of birth (NEOCAST), sham‐castrated on the day of birth (NEOSHAM) or castrated as adults (ADULTCAST). With the exception of one group of neonatal sham males (NEOSHAM CON), which served as a control for the effects of vasopressin, as adults, all males received a 1‐µl intracerebroventricular injection of vasopressin (100 ng) in artificial cerebrospinal fluid. In addition, 2 weeks before testing, one group of neonatally castrated males received an implant of testosterone propionate (NEOCAST + TP). Between 60 and 90 days of age, an internal cannula was placed in the lateral cerebral ventricle and, 24 h later, males were injected with vasopressin. Subsequently, after an additional 15 min, males were cohabitated with a female ‘partner’ for 1 h. Immediately following cohabitation, males were placed in a Y‐shaped partner preference test apparatus for 3 h, in which the male had access to the ‘partner’ and a novel female, ‘stranger.’ Time spent with the partner versus the stranger was compared within and between treatments. The results were found to support our hypothesis as the NEOSHAM and ADULTCAST males formed partner preferences, spending more time with the partner, and they spent significantly more time with their partner than did NEOSHAM CON, NEOCAST or NEOCAST + TP males. Replacement of testosterone in neonatally castrated males did not restore partner preference formation in response to vasopressin in adult males. Finally, neonatal castration did not affect the distribution of V1a receptors.
Immunoreactive Galanin Expression in Ovine Gonadotropin‐Releasing Hormone Neurones: No Effects of Gender or Reproductive Status
Authors: Dufourny L. , Schofield N. , Skinner D. C. 
Published: October 2003

AbstractThe neuropeptide, galanin, has been implicated to play a significant role in numerous physiological functions, including reproduction. Studies on several species have shown that galanin enhances gonadotropin‐releasing hormone (GnRH)‐induced luteinizing hormone secretion. In rodents, a subset of GnRH neurones expresses galanin in a sexually dimorphic manner and it has been suggested that this may underpin the differences in GnRH secretion observed between the sexes. However, there are few data available for other species. Previous studies in sheep have shown that the distribution of GnRH neurones overlaps with galanin cells. The primary objectives of our study were to determine whether GnRH and galanin coexist in the sheep brain and, importantly, if a sex difference is apparent in the colocalization of these two peptides. Using immunocytochemistry coupled to high temperature antigen retrieval, we found that all GnRH neurones in the ovine brain colocalize with galanin. There is also a distinct population of galanin neurones that do not secrete GnRH. In addition, the distribution of galanin‐immunoreactive cells was similar to that previously reported for colchicine treated ewes and, in agreement with earlier studies, the number of GnRH neurones did not differ between rams and ewes or between ewes killed at different stages of the oestrous cycle. These results suggest that, in sheep, GnRH and galanin may be cosecreted but the functional significance of this coexpression and possible cosecretion remains to be elucidated.
APJ Receptor mRNA Expression in the Rat Hypothalamic Paraventricular Nucleus: Regulation By Stress and Glucocorticoids
Authors: O'Carroll A.‐M. , Don A. L. J. , Lolait S. J. 
Published: October 2003

AbstractThe apelin receptor (APJ receptor, APJR) has recently come to prominence following the isolation and identification of its endogenous ligand, apelin, from bovine stomach tissue extracts. Investigation of APJR mRNA expression has revealed a hypothalamic distribution similar to that of vasopressin suggesting that the apelin–APJR system may be involved in the regulation of the hypothalamic‐adrenal‐pituitary (HPA) stress axis. To investigate whether APJR is involved in the regulation of hypothalamic function during stress, APJR mRNA expression levels were measured by in situ hybridization in the hypothalamus of rats subjected to acute and repeated restraint stress. Acute stress caused an increase in APJR mRNA expression in the hypothalamic parvocellular paraventricular nucleus (pPVN) while repeated restraint stress induced a sustained up‐regulation of pPVN APJR mRNA expression in intact rats. Removal of endogenous glucocorticoids by adrenalectomy also resulted in an increased expression of APJR mRNA in the PVN, suggesting a negative regulation of APJR mRNA expression by glucocorticoids. The role of glucocorticoids in mediating these stress‐induced changes was investigated by analysing the effects of acute and repeated restraint stress on APJR mRNA levels in adrenalectomized rats. In these rats, APJR mRNA expression levels did not change above the already elevated levels of adrenalectomized‐control rats. These data suggest that acute and repeated stress exert a stimulatory influence on APJR mRNA expression at the hypothalamic level that may be dependent on basal levels of circulating glucocorticoids, and further suggest a role for APJR in the regulation of hypothalamic function.
Genes encoding a cellulosic polymer contribute toward the ecological success of Pseudomonas fluorescens SBW25 on plant surfaces
Authors: Gal Micaela , Preston Gail M. , Massey Ruth C. , Spiers Andrew J. , Rainey Paul B. 
Published: October 2003

Abstract Pseudomonas fluorescens SBW25 is a Gram‐negative bacterium that grows in close association with plants. In common with a broad range of functionally similar bacteria it plays an important role in the turnover of organic matter and certain isolates can promote plant growth. Despite its environmental significance, the causes of its ecological success are poorly understood. Here we describe the development and application of a simple promoter trapping strategy (IVET) to identify P. fluorescens SBW25 genes showing elevated levels of expression in the sugar beet rhizosphere. A total of 25 rhizosphere‐induced (rhi) fusions are reported with predicted roles in nutrient acquisition, stress responses, biosynthesis of phytohormones and antibiotics. One rhi fusion is to wss, an operon encoding an acetylated cellulose polymer. A mutant carrying a defective wss locus was competitively compromised (relative to the wild type) in the rhizosphere and in the phyllosphere, but not in bulk soil. The rhizosphere‐induced wss locus therefore contributes to the ecological performance of SBW25 in the plant environment and supports our conjecture that genes inactive in the laboratory environment, but active in the wild, are likely to be determinants of fitness in natural environments.
Population dynamics and gene transfer in genetically modified bacteria in a model microcosm
Authors: Lilley A. K. , Bailey M. J. , Barr M. , Kilshaw K. , Timms‐Wilson T. M. , Day M. J. , Norris S. J. , Jones T. H. , Godfray H. C. J. 
Published: October 2003

AbstractThe horizontal transfer and effects on host fitness of a neutral gene cassette inserted into three different genomic loci of a plant‐colonizing pseudomonad was assessed in a model ecosystem. The KX reporter cassette (kanamycin resistance, aph, and catechol 2, 3, dioxygenase, xylE) was introduced on the disarmed transposon mini‐Tn5 into: (I) the chromosome of a spontaneous rifampicin resistant mutant Pseudomonas fluorescens SBW25R; (II) the chromosome of SBW25R in the presence of a naturally occurring lysogenic‐phage (phage Φ101); and (III) a naturally occurring plasmid pQBR11 (330 kbp, tra+, Hgr) introduced into SBW25R. These bacteria were applied to Stellaria media (chickweed) plants as seed dressings [c. 5 × 104 colony‐forming units (cfu)/seed] and the seedlings planted in 16 microcosm chambers containing model plant and animal communities. Gene transfer to pseudomonads in the phyllosphere and rhizosphere was found only in the plasmid treatment (III). Bacteria in the phage treatment (II) initially declined in density and free phage was detected, but populations partly recovered as the plants matured. Surprisingly, bacteria in the chromosome insertion treatment (I) consistently achieved higher population densities than the unmanipulated control and other treatments. Plasmids were acquired from indigenous bacterial populations in the control and chromosome insertion treatments. Plasmid acquisition, plasmid transfer from inocula and selection for plasmid carrying inocula coincided with plant maturation.
Evidence for genetic monogamy and female‐biased dispersal in the biparental mouthbrooding cichlid Eretmodus cyanostictus from Lake Tanganyika
Authors: Taylor Martin I. , Morley Josephine Isabelle , Rico Ciro , Balshine Sigal 
Published: October 2003

AbstractIn this study, we investigate whether apparent social monogamy (where a species forms a pair bond but may participate in copulations outside the pair bond) corresponds with genetic monogamy (where individuals participate only in copulations within a pair bond) in a biparental mouthbrooding cichlid fish, Eretmodus cyanostictus, from Lake Tanganyika, Africa. Our findings suggest that E. cyanostictus is both socially and genetically monogamous and that monogamy may result from limited opportunities for polygyny, rather than from reproductive benefits of monogamy. Mating systems are believed to influence the relative rate of dispersal of the sexes, and our results suggest that E. cyanostictus displays female‐biased dispersal, providing some support for the ‘resource competition’ hypothesis driving sex‐biased dispersal.
Interspecific hybridization in plant‐associated fungi and oomycetes: a review
Authors: Schardl C. L. , Craven K. D. 
Published: October 2003

AbstractFungi (kingdom Mycota) and oomycetes (kingdom Stramenopila, phylum Oomycota) are crucially important in the nutrient cycles of the world. Their interactions with plants sometimes benefit and sometimes act to the detriment of humans. Many fungi establish ecologically vital mutualisms, such as in mycorrhizal fungi that enhance nutrient acquisition, and endophytes that combat insects and other herbivores. Other fungi and many oomycetes are plant pathogens that devastate natural and agricultural populations of plant species. Studies of fungal and oomycete evolution were extraordinarily difficult until the advent of molecular phylogenetics. Over the past decade, researchers applying these new tools to fungi and oomycetes have made astounding new discoveries, among which is the potential for interspecific hybridization. Consequences of hybridization among pathogens include adaptation to new niches such as new host species, and increased or decreased virulence. Hybrid mutualists may also be better adapted to new hosts and can provide greater or more diverse benefits to host plants.
A morphological cline inEucalyptus: a genetic perspective
Authors: Holman James E. , Hughes Jane M. , Fensham Rod J. 
Published: October 2003

AbstractThe putative hybrid zone betweenEucalyptus populneaandE. browniiis examined using morphological and molecular techniques. This species complex displays continuous morphological variation across the study area, which has been previously interpreted as the product of hybridization between allopatric species. A microsatellite analysis indicates that there was little genetic structuring across the morphological cline and only low levels of population differentiation. The nested clade analysis of the JLA+region of the chloroplast DNA (cpDNA) indicates that the geographical distribution of cpDNA haplotypes is unlikely to be the result of historical hybridization events, and that restricted seed‐mediated gene flow with isolation by distance is responsible for the phylogeographical distribution. A more plausible explanation for the origin and persistence of the morphological cline is that the process of continuous morphological diversification has been promoted by a directional selection gradient. This study addresses species status withinEucalyptusand the belief that hybridization is widespread and is an important process in the group's evolution.
Wood ingestion by passalid beetles in the presence of xylose‐fermenting gut yeasts
Authors: Suh Sung‐Oui , Marshall Christopher J. , Mchugh Joseph V. , Blackwell Meredith 
Published: October 2003

AbstractDuring a survey of insect gut micro‐organisms, we consistently isolated Pichia stipitis‐like yeasts (Fungi: Ascomycota, Saccharomycetes) from the wood‐ingesting beetles, Odontotaenius disjunctus and Verres sternbergianus (Coleoptera: Passalidae). The yeasts were isolated from passalid beetles over a wide area, including the eastern and midwestern USA and Panama. Phylogenetic analyses of the nuclear encoded small and large subunit rRNA gene (rDNA) sequences distinguished a well‐supported clade consisting of the passalid yeasts and Pichia stipitis, P. segobiensis, Candida shehatae and C. ergatensis. Members of this clade have the ability to ferment and assimilate xylose or to hydrolyse xylan, major components of the polysaccharide, hemicellulose. Sexual reproduction was present in the passalid isolates but was rare among the gut yeasts of other beetles to which they were compared. Minor genetic and phenotypic variation among some of the passalid yeasts was detected using markers from the internal transcribed spacer region of the rDNA repeat unit, morphology, and in vitro metabolic tests. The consistent association of xylose‐fermenting yeasts of almost identical genotypes with passalid beetles across a broad geographical distribution, suggests a significant symbiotic association.
Cytonuclear disequilibrium in a hybrid zone involving deep‐sea hydrothermal vent mussels of the genus Bathymodiolus
Authors: Won Y. , Hallam S. J. , O'Mullan G. D. , Vrijenhoek R. C. 
Published: October 2003

AbstractA hybrid zone involving the deep‐sea mussels, Bathymodiolus azoricus and B. puteoserpentis, was recently discovered at Broken Spur hydrothermal vent field (29°10′ N, 43°10′ W) along an intermediate segment of the Mid‐Atlantic Ridge axis. Examination of nuclear (allozymes) and cytoplasmic (mitochondrial DNA) gene markers in a new sample from Broken Spur revealed significant cytonuclear disequilibrium caused by an excess of the parental types (coupling phase) and a deficiency of recombinants (repulsion phase). An assignment test of individual multilocus genotypes also revealed an excess of parental genotypes in the admixed population. These results support the hypothesis that the Broken Spur mussel population comprises a nonequilibrium mixture of parental immigrants and hybrid individuals.
Long‐term temporal changes of genetic composition in brown trout (Salmo truttaL.) populations inhabiting an unstable environment
Authors: Østergaard Siri , Hansen Michael M. , Loeschcke Volker , Nielsen Einar E. 
Published: October 2003

AbstractThe genetic structure of brown trout (Salmo trutta) populations inhabiting rivers on the island of Bornholm in the Baltic Sea was studied on a spatial and temporal scale. Low water levels in the rivers during the summer period are assumed to have a significant impact on the persistence of local populations, possibly resulting in a metapopulation structure. Extinctions may, however, also be buffered by a remnant strategy, whereby juveniles escape to river outlets during periods of drought. We compared polymorphism at seven microsatellite DNA loci in contemporary and past samples collected from 1944 to 1997. A principal component analysis, a hierarchical gene diversity analysis and assignment tests showed that the genetic composition of populations was not temporally stable, and that temporal genetic differentiation was much stronger than spatial differentiation. Genetic variability was high and stable over time. Effective population sizes (Ne) and migration rate (m) were estimated using a maximum‐likelihood‐based implementation of the temporal method.Neestimates were low (ranging from 8.3 to 22.9) and estimates ofmwere high (between 0.23 and 0.99), in contrast to other Danish trout populations inhabiting larger and more environmentally stable rivers (Nebetween 39.2 and 289.9 andmbetween 0.01 and 0.09). Thus, the observed spatio‐temporal patterns of genetic differentiation can be explained by drift in small persisting populations, where levels of genetic variation are maintained by strong gene flow. However, observations of rivers devoid of trout suggested that population turnover also takes place. We suggest that Bornholm trout represent a metapopulation where the genetic structure primarily reflects strong drift and gene flow, combined with occasional extinction–recolonization events.
Phylogeography of Biomphalaria glabrata and B. pfeifferi, important intermediate hosts of Schistosoma mansoni in the New and Old World tropics
Authors: Dejong R. J. , Morgan J. A. T. , Wilson W. D. , Al‐Jaser M. H. , Appleton C. C. , Coulibaly G. , D’Andrea P. S. , Doenhoff M. J. , Haas W. , Idris M. A. , Magalhães L. A. , Moné H. , Mouahid G. , Mubila L. , Pointier J.‐P. , Webster J. P. , Zanotti‐Magalhães E. M. , Paraense W. L. , Mkoji G. M. , Loker E. S. 
Published: October 2003

AbstractThe historical phylogeography of the two most important intermediate host species of the human blood fluke Schistosoma mansoni, B. glabrata in the New World, and B. pfeifferi in the Old World, was investigated using partial 16S and ND1 sequences from the mitochondrial genome. Nuclear sequences of an actin intron and internal transcribed spacer (ITS)‐1 were also obtained, but they were uninformative for the relationships among populations. Phylogenetic analyses based on mtDNA revealed six well‐differentiated clades within B. glabrata: the Greater Antilles, Venezuela and the Lesser Antilles, and four geographically overlapping Brazilian clades. Application of a Biomphalaria‐specific mutation rate gives an estimate of the early Pleistocene for their divergence. The Brazilian clades were inferred to be the result of fragmentation, due possibly to climate oscillations, with subsequent range expansion producing the overlapping ranges. Within the Venezuela and Lesser Antilles clade, lineages from each of these areas were estimated to have separated approximately 740 000 years ago. Compared to B. glabrata, mitochondrial sequences of B. pfeifferi are about 4× lower in diversity, reflecting a much younger age for the species, with the most recent common ancestor of all haplotypes estimated to have existed 880 000 years ago. The oldest B. pfeifferi haplotypes occurred in southern Africa, suggesting it may have been a refugium during dry periods. A recent range expansion was inferred for eastern Africa less than 100 000 years ago. Several putative species and subspecies, B. arabica, B. gaudi, B. rhodesiensis and B. stanleyi, are shown to be undifferentiated from other B. pfeifferi populations.