bluuebunny/crossref_metadata_2025_split huggingface dataset:
3  ISCHEMIC MITRAL VALVE REPAIR: THE IMPACT OF THE MECHANISM OF MITRAL REGURGITATION ON LATE POSTOPERATIVE RESULTS
Authors: Ereminienė E. , Vaskelyte J. , Jurkevicius R. 
Published: October 2004

Aim: The aim of our study was to establish the anatomical‐functional mechanisms of ischemic mitral regurgitation (MR) and to analyse its impact on late results after mitral valve (MV) reconstructive surgery. Methods: The study included 53 patients with ischemic MR, who underwent CABG and MV repair. MV surgery consisted of subvalvular apparatus repair and/or annuloplasty. 2D Doppler investigations performed pre‐, 10–14 days, and 12 months after surgery included evaluation of MV and left ventricular (LV) geometry and function. Results: Analysis of the mechanisms of ischemic MR permitted dividing patients into two groups: group 1—29 patients with inferobasal scar and posterior papillary muscle (PM) displacement, including 22 patients with PM infarction and 7 patients without it, and group 2—24 patients with isolated mitral annulus (MA) dilation. In the case of PM infarction two different mechanisms of MR were stated: (a) P3 restriction and A3 prolapse due to chordal tethering, (b) A3 P3 (commissural) prolapse due to chordal papillary elongation. Preoperatively LV geometry and function were better preserved in group 1 and late MV repair results were better versus (vs.) group 2: LV end‐systolic diameter index decreased from 22.9 ± 3.1 mm/m2 to 20.9 ± 3.6 mm/m2 at 1 year, p < 0.05, LV ejection fraction increased from 34.9 ± 8.4 to 41.8 ± 8.1%, respectively, p < 0.05. No significant changes in LV geometry and function were noted in group 2. Conclusions: The underlying mechanism of ischemic MR has an impact on MV repair results. In patients with MR due to posterobasal infarction MV repair resulted in more favorable postoperative effect‐marked improvement in LV geometry and function late after surgery versus MR due to isolated MA dilation.
5  DIAGNOSTIC PITFALLS IN THE ECHOCARDIOGRAPHIC EVALUATION OF HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM) REFERRED FOR CATHETER INTERVENTIONAL THERAPY
Authors: Beer G. , Kuhn. H. 
Published: October 2004

Introduction: Generally, the diagnosis of typical HOCM with subaortic obstruction and a dynamic pressure gradient across the left ventricular outflow tract is made by noninvasive diagnostic procedures with great certainty by employing transthoracic (TTE) and/or transoesophageal (TEE) echocardiography. However, in patients with asymmetric septal hypertrophy pitfalls in echocardiographic examination may arise from several additional diseases as described in casuistic reports. To date systematic investigations in patients referred for catheter interventional therapy of HOCM are lacking. Patients and Methods: Therefore we investigated for the first time in a systematic study 200 symptomatic patients. (180 consecutive and 20 nonconsecutive patients; functional class 3 or 4 according to NYHA) with HOCM who were referred for this new catheter interventional therapy. In all patients TTE, bicycle exercise Doppler echocardiography and multiplane TEE were performed. Results: In 4 of 180 consecutive patients. (2.2%) discrete subvalvular membranous aortic stenosis (DSAS) (3 female patients and 1 male patient; age 20 to 58 years; mean septal diameter 19 mm; Sam‐like motion in all 4 patients) was made. In all cases the diagnosis could be confirmed by surgical treatment. TEE evaluation was of crucial importance with demonstration of a typical subvalvular membrane that was situated a few millimeters below the aortic valve. In all cases a typical asymmetric septal hypertrophy mimicking HOCM was seen. Additionally, in 2 patients there was a conincidence of severe symptomatic valvular aortic stenosis and HOCM and in 1 patient a tunnel type of subvalvular aortic stenosis was present. Conclusion: These results show the potential pitfalls in echocardiographic diagnosis of HOCM. Especially, the frequency of DSAS in symptomatic patients referred for HOCM is unexpectedly high (2.2%). Especially in patients in whom TTE is of insufficient quality, investigation employing multiplane TEE with careful evaluation of the small poststenotic subvalvular area in HOCM is of crucial importance. This is of special significance prior to catheter interventional therapy, because in these patients surgical treatment is mandatory.
A global invader at home: population structure of the green crab, Carcinus maenas, in Europe
Authors: ROMAN JOE , PALUMBI STEPHEN R. 
Published: October 2004

AbstractThe European green crab, Carcinus maenas, has a native distribution that extends from Norway to Mauritania. It has attracted attention because of its recent invasions of Australia, Tasmania, South Africa, Japan and both coasts of North America. To examine the population structure of this global invader in its native range, we analysed a 502‐base‐pair fragment of the mitochondrial cytochrome c oxidase I (COI) gene from 217 crabs collected in the North Atlantic and 13 specimens from the Mediterranean. A clear genetic break (11% sequence divergence) occurs between the Mediterranean and Atlantic, supporting the species‐level status of these two forms. Populations in the Faeroe Islands and Iceland were genetically distinct from continental populations (FST = 0.264–0.678), with Iceland represented by a single lineage also found in the Faeroes. This break is consistent with a deep‐water barrier to dispersal in green crabs. Although there are relatively high levels of gene flow along the Atlantic coast of Europe, slight population structure was found between the central North Sea and populations to the south. Analysis of variance, multidimensional scaling, and the distribution of private haplotypes support this break, located between Bremerhaven, Germany, and Hoek van Holland. Similar biogeographical and genetic associations for other species, such as benthic algae and freshwater eels, suggest that the marine fauna of Europe may be generally subdivided into the areas of Mediterranean, western Europe and northern Europe.
INVITED REVIEW: Plant self‐incompatibility in natural populations: a critical assessment of recent theoretical and empirical advances
Authors: CASTRIC VINCENT , VEKEMANS XAVIER 
Published: October 2004

AbstractSelf‐incompatibility systems in plants are genetic systems that prevent self‐fertilization in hermaphrodites through recognition and rejection of pollen expressing the same allelic specificity as that expressed in the pistils. The evolutionary properties of these self‐recognition systems have been revealed through a fascinating interplay between empirical advances and theoretical developments. In 1939, Wright suggested that the main evolutionary force driving the genetic and molecular properties of these systems was strong negative frequency‐dependent selection acting on pollination success. The empirical observation of high allelic diversity at the self‐incompatibility locus in several species, followed by the discovery of very high molecular divergence among alleles in all plant families where the locus has been identified, supported Wright's initial theoretical predictions as well as many of its later developments. In the last decade, however, advances in the molecular characterization of the incompatibility reaction and in the analysis of allelic frequencies and allelic divergence from natural populations have stimulated new theoretical investigations that challenged some important assumptions of Wright's model of gametophytic self‐incompatibility. We here review some of these recent empirical and theoretical advances that investigated: (i) the hypothesis that S‐alleles are selectively equivalent, and the evolutionary consequences of genetic interactions between alleles; (ii) the occurrence of frequency‐dependent selection in female fertility; (iii) the evolutionary genetics of self‐incompatibility systems in subdivided populations; (iv) the evolutionary implications of the self‐incompatibility locus's genetic architecture; and (v) of its interactions with the genomic environment.
Inbreeding and population structure of the potato cyst nematode (Globodera pallida) in its native area (Peru)
Authors: PICARD D. , PLANTARD O. , SCURRAH M. , MUGNIÉRY D. 
Published: October 2004

AbstractThe dispersal abilities and the population genetic structure of nematodes living in the soil are poorly known. In the present study, we have pursued these issues in the potato cyst nematode Globodera pallida, which parasitizes potato roots and is indigenous to South America. A hierarchical sampling regime was conducted in Peru to investigate gene flow on regional, field and plant scales. Multilocus genotypes of single individuals were obtained using eight polymorphic microsatellites markers. Large heterozygote deficiencies were observed at most loci. The limited active dispersal of larvae from their cyst, which favours mating between (half) siblings, could be responsible for this pattern. Within fields, as well as among fields within regions (even 35 km apart), low FST values suggest extensive gene flow. Among fields within regions, only 1.5–4.4% genetic variability was observed. Passive dispersal of cysts by natural means (wind, running water, or wild animals) or by anthropogenic means (tillage, movement of infected seed tubers) is probably responsible for the results observed. Among regions, high FST values were observed. Thus long‐range dispersal (more than 320 km apart) is probably limited by major biogeographical barriers such as the mountains found in the Andean Cordillera. These results provide useful information for the management of resistant varieties, to slow down the emergence and spread of resistance‐breaking pathotypes.
Major alteration of the expression site of endogenous cellulases in members of an apical termite lineage
Authors: TOKUDA GAKU , LO NATHAN , WATANABE HIROFUMI , ARAKAWA GAKU , MATSUMOTO TADAO , NODA HIROAKI 
Published: October 2004

AbstractTermites are among the most important cellulose‐digesting animals on earth, and are well‐known for the symbiotic relationship they have with cellulolytic trichomonad and oxymonad flagellates (unicellular eukaryotes). Perhaps less well‐known is the fact that ∼75% of the ∼2600 described termite species — those belonging to the family Termitidae — do not harbour such flagellates. Unlike most termites from other families, the majority of termitids do not consume wood, feeding instead on soil, leaf litter, fungi, grass, or lichen. Recent years have seen the characterization of the endogenous cellulase enzymes that help termites digest cellulose, from one flagellate‐harbouring species (Reticulitermes speratus), as well as one termitid (Nasutitermes takasagoensis). The genes encoding the enzymes in these two termites are similar. However, their site of expression differs markedly — the salivary glands in R. speratus and the midgut in N. takasagoensis. To investigate this difference further, we performed a comparative study of cellulase expression in various termitid and flagellate‐harbouring species, using enzyme assays and reverse transcription polymerase chain reactions. Taxa from phylogenetically basal lineages were consistently found to express endogenous genes specifically in the salivary glands, whilst those from a relatively apical lineage containing termitids expressed cellulases solely in the midgut. Relatively low levels of cellulase activity were found in nonwood‐feeding species, while the wood‐feeding Coptotermes formosanus— arguably the most destructive pest species world‐wide — was found to have high levels of activity in all parts of the gut when compared to all other termites. In the light of these results, as well as recently accumulated phylogenetic data, we discuss scenarios for the evolution of cellulose digestion in termites.
COMMENTARY: How cryptic is the Scandinavian lynx?
Authors: PAMILO P. 
Published: October 2004

AbstractA reanalysis of the existing genotypic data shows that they are compatible with the hypothesis that the present‐day Scandinavian lynx represents a recent expansion from a single source. This contradicts earlier conclusions. The difference arises when it is assumed that the expansion and colonization have been stochastic processes and that the populations may not be at a drift‐migration equilibrium.
Phylogeography of roe deer (Capreolus capreolus) populations: the effects of historical genetic subdivisions and recent nonequilibrium dynamics
Authors: RANDI E. , ALVES P. C. , CARRANZA J. , MILOŠEVIĆ‐ZLATANOVIĆ S. , SFOUGARIS A. , MUCCI N. 
Published: October 2004

AbstractWe sequenced 704 mitochondrial DNA (mtDNA) control‐region nucleotides and genotyped 11 autosomal microsatellites (STR) in 617 European roe deer (Capreolus capreolus) samples, aiming to infer the species’ phylogeographical structure. The mtDNA sequences were split in three distinct haplogroups, respectively, named: Clade West, sampled mainly in Iberia; Clade East, sampled mainly in Greece and in the Balkans; and Clade Central, which was widespread throughout Europe, including the eastern countries and Iberia, but not Greece. These clades might have originated in distinct Iberian and Balkanic refuges during the penultimate or the last glaciations. Clades East and West contributed little to the current postglacial mtDNA diversity in central Europe, which apparently was recolonized mainly by haplotypes belonging to Clade Central. A unique subclade within Clade Central grouped all the haplotypes sampled from populations of the Italian subspeciesC. c. italicus. In contrast, haplotypes sampled in central and southern Spain joined both Clade Central and Clade West, suggesting that subspeciesC. c. gargantahas admixed origin. STR data support a genetic distinction of peripheral populations in north Iberia and southern Italy, and show the effects of anthropogenic disturbance in fragmented populations, which were recently reintroduced or restocked and not may be in mutation–drift equilibrium. Roe deer in central Europe are mainly admixed, while peripheral populations in north Portugal, the southern Italian Apennines and Greece represent the remains of refugial populations and should be managed accordingly.
Pleistocene glaciation is implicated in the phylogeographical structure of Potamopyrgus antipodarum, a New Zealand snail
Authors: NEIMAN MAURINE , LIVELY CURTIS M. 
Published: October 2004

AbstractPleistocene glaciation has been identified as an important factor shaping present‐day patterns of phylogeographical structure in a diverse array of taxa. The purpose of this study was to use mitochondrial sequence data to address whether Pleistocene glaciation is also a major determinant of phylogeographical patterns in Potamopyrgus antipodarum, a freshwater snail native to New Zealand. We found that haplotypes were separated by no more than 3.7% sequence divergence, and major genetic divisions tended to occur on a north–south axis. These data fit the predictions of the hypothesis that isolation of P. antipodarum in glacial refugia at the northern and southern tip of the South Island of New Zealand during the Pleistocene glaciation underlies the present‐day phylogeographical structure. Because sexual P. antipodarum occasionally produce asexual offspring, we also used these data to show that the appearance of asexuality is not phylogeographically constrained. This means that the maintenance of sex in P. antipodarum cannot be wholly due to limited contact between sexual and asexual lineages and must instead be linked to a selective advantage of sexual reproduction.
Temperature‐mediated seasonal variation in phosphoglucomutase allozyme frequency in the yellow dung fly, Scathophaga stercoraria
Authors: WARD P. I. , JANN P. , BLANCKENHORN W. U. 
Published: October 2004

AbstractThe allozyme genetic variability of various species is correlated with a variety of morphological, physiological and fitness‐related traits. In particular, temperature can affect the fitness of insects through its influence on enzyme function. We examined the seasonal (12 days over 1 year) and daily (nine samples over each day) allozyme variation at the phosphoglucomutase (PGM) locus in one population of yellow dung flies (Scathophaga stercoraria; Diptera: Scathophagidae). PGM is of central functional importance in the mobilization of glycogen reserves for flight, and has been shown to affect larval growth at different temperatures in the laboratory. Based on a sample of over 3000 flies, we found a quadratic relationship, with a minimum at ~12 °C, between the frequency of the most common allele and temperature, primarily mediated by seasonal temperature variation. This could be caused by behavioural responses over the short‐term, but over the year either variable viability or sexual selection probably operates on this locus, maintaining the existing polymorphism. These results call for further work on the functional differences between PGM allozyme genotypes.
Phylogeography of two European Reticulitermes (Isoptera) species: the Iberian refugium
Authors: KUTNIK M. , UVA P. , BRINKWORTH L. , BAGNÈRES A.‐G. 
Published: October 2004

AbstractChemical, i.e. cuticular hydrocarbons, and molecular data were used to probe the phylogeography of Reticulitermes termites collected from various parts of France, Spain and Portugal. Phylogenetic relationships were inferred from sequences of the internal transcribed spacer (ITS2) of nuclear ribosomal RNA genes as well as from two partial mitochondrial DNA segments, the cytochrome oxidase II gene and a sequence combining the tRNA‐Leu gene and fragments of the NADH dehydrogenase I and ribosomal 16S genes. Two species, namely, R. grassei and R. banyulensis, were identified based on an analysis of cuticular hydrocarbons and the identification was confirmed by ITS2 haplotyping. However, phylogeny based on the analysis of mitochondrial DNA was not completely in agreement with the conclusions drawn from the chemical and nuclear data. An analysis of 56 R. grassei colonies revealed intraspecific differentiation into two major lineages with distinct geographical ranges. Whereas analysis of cuticular hydrocarbons showed that R. banyulensis was chemically distinct from R. grassei, analysis of mitochondrial DNA showed its close kinship with the R. grassei lineage occurring in southern Spain. This kinship could be explained by their evolution from a common polymorphic ancestor species in this ice age refugium.
Community structure of arbuscular mycorrhizal fungi in undisturbed vegetation revealed by analyses of LSU rDNA sequences
Authors: ROSENDAHL SØREN , STUKENBROCK EVA H. 
Published: October 2004

AbstractArbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with plant roots and are found in most ecosystems. In this study the community structure of AMF in a clade of the genus Glomus was examined in undisturbed costal grassland using LSU rDNA sequences amplified from roots of Hieracium pilosella. Roots were sampled from May to November along eight 30‐m transects, 30–120 m apart. Phylogenetic analysis of the sequences revealed 11 phylogenetic clusters within the clade of Glomus. The phylogenetic clusters were patchily distributed within the area; time had no influence on the distribution pattern. The dominant cluster covered up to 10 m along the transect, whereas other clusters formed what can be interpreted as small individual mycelia. Four of the phylogenetic clusters included known species; the other clusters, including the dominant sequence types, were unknown. The dominant phylogenetic cluster enclosed nine haplotypes, and analyses of genetic diversity of this phylogenetic cluster showed that the total diversity could be found within single root fragments, suggesting that the multiple sequences were derived from a single individual.
The power and perils of ‘molecular taxonomy’: a case study of eyeless and endangered Cicurina (Araneae: Dictynidae) from Texas caves
Authors: PAQUIN P. , HEDIN M. 
Published: October 2004

AbstractRapid development in karst‐rich regions of the US state of Texas has prompted the listing of four Cicurina species (Araneae, Dictynidae) as US Federally Endangered. A major constraint in the management of these taxa is the extreme rarity of adult specimens, which are required for accurate species identification. We report a first attempt at using mitochondrial DNA (mtDNA) sequences to accurately identify immature Cicurina specimens. This identification is founded on a phylogenetic framework that is anchored by identified adult and/or topotypic specimens. Analysis of ~1 kb of cytochrome oxidase subunit I (CO1) mtDNA data for over 100 samples results in a phylogenetic tree that includes a large number of distinctive, easily recognizable, tip clades. These tip clades almost always correspond to a priori species hypotheses, and show nonoverlapping patterns of sequence divergence, making it possible to place species names on a number of immature specimens. Three cases of inconsistency between recovered tip clades and a priori species hypotheses suggest possible introgression between cave‐dwelling Cicurina, or alternatively, species synonymy. Although species determination is not possible in these instances, the inconsistencies point to areas of taxonomic ambiguity that require further study. Our molecular phylogenetic sample is largest for the Federally Endangered C. madla. These data suggest that C. madla occurs in more than twice the number of caves as previously reported, and indicate the possible synonymy of C. madla with C. vespera, which is also Federally Endangered. Network analyses reveal considerable genetic divergence and structuring across caves in this species. Although the use of DNA sequences to identify previously ‘unidentifiable’ specimens illustrates the potential power of molecular data in taxonomy, many other aspects of the same dataset speak to the necessity of a balanced taxonomic approach.
Development of Y‐chromosomal microsatellite markers for nonhuman primates
Authors: ERLER AXEL , STONEKING MARK , KAYSER MANFRED 
Published: October 2004

AbstractWe have analysed 136 newly identified human Y‐chromosomal microsatellites in five (sub)species of nonhuman primates. We identified 83 male‐specific loci for central chimpanzees, 82 for western chimpanzees, 67 for gorillas, 45 for orangutans and 19 loci for mandrills. Polymorphism was detected at 56 loci in central chimpanzees, 29 in western chimpanzees, 24 in western gorillas, 17 in orangutans and at three in mandrills. Success in male‐specific amplification of human Y‐chromosomal microsatellites in nonhuman primates was significantly negatively correlated with divergence time from the human lineage. We observed significantly more Y‐chromosomal microsatellite diversity in central chimpanzees than in western chimpanzees. There were significantly more male‐specific loci with longer alleles in humans than with longer alleles in the nonhuman primates; however, this significant difference disappeared when only the loci which are polymorphic in nonhuman primates were analysed, suggesting that ascertainment bias is responsible. This study provides primatologists with a large number of polymorphic, male‐specific microsatellite markers that will be valuable for investigating relevant questions in behavioural ecology such as male reproductive strategies, kin‐based cooperation among males and male‐specific dispersal patterns in wild groups of nonhuman primates.