bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative breakdown of octanoic acid is maintained in patients with cirrhosis despite advanced disease
Authors: Van de Casteele M. , Luypaerts A. , Geypens B. , Fevery J. , Ghoos Y. , Nevens F.
Published: December 2004

Abstract  As an octanoic acid 13CO2 breath test is frequently used to test gastric emptying of solid food, the purpose of the present study was to study whether oxidative breakdown of octanoic acid is affected by severe liver disease. The design of our study was twofold. First, cirrhotic patients (n = 82) of varying severity were compared with healthy controls (n = 17). Values of half‐time, time point of maximal expiration and cumulative recovery of octanoic acid breath tests (OBT) were not significantly different between them. Secondly, cirrhotic patients (n = 10) were studied before placement of transjugular intrahepatic portosystemic shunt, 4–7 days later and 1–2 months later. Values of half‐time, time point of maximal expiration and cumulative recovery of consecutive OBTs did not change significantly. The OBT may therefore be a suitable test in the future to detect delayed gastric emptying of solids in cirrhotic patients with reduced liver function and portal hypertension.
Effect of interval between swallows on oesophageal pressures and bolus movement in normal subjects – Studies with combined multichannel intraluminal impedance and oesophageal manometry
Authors: Tutuian R. , Jalil S. , Katz P. O. , Castell D. O.
Published: December 2004

Abstract  The effect of closely spaced swallows to decrease peristalsis (‘deglutitive inhibition’) is believed to be due to both central inhibitory impulses and smooth muscle refractoriness. Ten volunteers (three females, age 26–65) were given both four pairs and two series of four swallows at 5‐, 10‐, 15‐s intervals and control swallows at 30‐s intervals. Oesophageal function was assessed using combined multichannel intraluminal impedance and oesophageal manometry (MII–OM). Swallows were considered manometrical effective if distal oesophageal pressures ≥30 mmHg. Complete bolus transit was defined as bolus exiting from all three distal impedance segments. During swallowing at 5‐s intervals the majority of initial swallows were ineffective with incomplete bolus transit while the last swallow in both series and pairs was manometrically effective with complete bolus transit. During swallowing at 10–15‐s intervals the number of manometric ineffective swallows and swallows with incomplete bolus transit progressively increased with the number of swallows. The functional information obtained by MII–OM indicates pooling of liquid in the distal oesophagus that is cleared by the last swallow determined by, previously reported, neural inhibition occurring during swallowing spaced 5 s apart whereas incomplete bolus transit is related to manometrically ineffective swallows resulting from muscle refractoriness occurring during swallowing at 10–15‐s intervals.
Sudden and unexpected death in epilepsy (SUDEP): evidence of acute neuronal injury using HSP‐70 and c‐Jun immunohistochemistry
Authors: Thom M. , Seetah S. , Sisodiya S. , Koepp M. , Scaravilli F.
Published: December 2004

Post‐mortem and neuropathological examination in sudden and unexpected death in epilepsy (SUDEP) shows no specific lesions and the exact cause and mechanism of death in these cases remains undetermined. There is clinical evidence to support the fact that SUDEP is a seizure‐mediated event, and patients with poorly controlled seizures are at higher risk. We aimed to identify any evidence of acute neuronal injury in SUDEP cases at post‐mortem to support that a recent seizure had occurred. We analysed the distribution and frequency of heat shock protein (HSP)‐70 and c‐Jun immunopositive neurones in the hippocampus in 18 SUDEP cases and 22 control cases, both markers being nonspecific but early and reliable indicators of acute neuronal injury. Post‐mortem control groups included patients with epilepsy with cause of death other than SUDEP (including status epilepticus and accidental death), and patients with sudden cardiac death without an epilepsy history. An additional surgical control group included patients with refractory epilepsy and hippocampal sclerosis who had undergone temporal lobectomy. Semiquantitative analysis of the distribution of HSP‐70 staining showed significantly more SUDEP cases with positively labelled neurones in hippocampal subfields compared to epilepsy and cardiac post‐mortem controls (P < 0.001) but not compared to the epilepsy surgical controls (P = 0.4). No significant difference in immunostaining patterns between groups was seen in the parahippocampal gyrus with HSP‐70 or with c‐Jun in either the hippocampus or parahippocampal gyrus regions. The detection of HSP‐70 positive neurones in the hippocampus in SUDEP is supportive of ante‐mortem neuronal injury including a recent seizure prior to death.
Glial levels determine severity of white matter disease in Alzheimer's disease: a neuropathological study of glial changes
Authors: Sjöbeck M. , Englund E.
Published: December 2004

The morphological components of cerebral white matter disease (WMD) were studied in 17 cases of clinically diagnosed dementia and neuropathologically verified Alzheimer's disease (AD) with concomitant WMD. The distribution of grey and white matter changes was evaluated and overall as well as regional severity was graded. Total glial numbers in frontal white matter were counted using a light microscope. Oligodendrocyte and astrocyte quantities as well as astrocytic reactivity were assessed from frontal and parietal lobe white matter using a computer assisted morphometric method. The AD–WMD group was compared with 10 nondemented age‐matched controls. Astrocyte/oligodendrocyte ratio (AOR) was calculated, total glial counts and AOR were compared with severity of WMD, and Alzheimer encephalopathy grade was subjectively assessed. Astrocytic numbers, AOR and astrocytic reactivity proved to be significantly higher in the demented group, whereas oligodendrocytic and total glial counts were significantly lower. Furthermore, AOR proved to be positively correlated with severity of WMD, whereas no association was found with Alzheimer encephalopathy. We conclude that WMD in dementia, for example, of the type seen in AD, can easily be detected, measured and graded quantitatively, with AOR being a significant indicator of the severity of changes. This could serve as a tool for differentiating white matter pathologies in dementia and may be the basis for recognition of the mildest white matter changes with new imaging methods, and enable potential clinical intervention.
Females avoid manipulative males and live longer
Authors: Moore A. J. , Gowaty P. A. , Moore P. J.
Published: December 2004

Female mate choice has been demonstrated in a wide variety of species and is now accepted as an important factor in sexual selection. One of the remaining questions, however, is why females prefer specific males. Do females or their offspring benefit from their choice? Or do females choose mates to minimize costs of mating? Here we show that, in the ovoviviparous cockroach Nauphoeta cinerea, where sexual selection has been well documented, females chose mates to avoid costly male manipulation. Females were partnered with preferred or nonpreferred mates, and fitness of the females measured. We found that females lived longer when they mated with preferred males. Female lifespan depended on the rate at which offspring developed from egg to parturition: slower development led to longer life. We manipulated the male pheromone and showed that the component of the pheromone blend that makes males attractive to females also delayed parturition. Thus, like other aspects of sexual conflict in this species, offspring development and thereby the mother's lifespan depended on exposure of females to specific components of the male pheromone. Males benefit from manipulating offspring development because females with accelerated parturition remained unreceptive whereas females with slower developing offspring readily remated after giving birth to their offspring. Our results suggest a hormone-like role for the male pheromone in N. cinerea and provide the first direct evidence of mate choice to avoid male manipulation. This study shows that dominant males may not be preferred males if they are manipulating females, why multiple components with contrasting effects can exist in a sexual signal, and emphasizes the complex fitness relationships that can arise in species with sexual conflict.
Adaptive seasonal trend in brood sex ratio: test in two sister species with contrasting breeding systems
Authors: Andersson M. , Wallander J. , Oring L. , Akst E. , Reed J. M. , Fleischer R. C.
Published: December 2004

Evolutionary theory predicts adaptive adjustment in offspring sex ratio by females. Seasonal change in sex ratio is one possibility, tested here in two sister species, the Common sandpiper and the Spotted sandpiper Actitis hypoleucos and A. macularia. In the monogamous Common sandpiper, males are the most competitive sex. In each of 3 years, there was a change from mainly sons in early clutches to mainly daughters in late clutches. This seasonal adjustment of clutch sex ratio took place within the female before the eggs were laid, not by differential egg or chick survival. The sex of all eggs laid in the clutches used here was determined molecularly from chick blood taken at the time of hatching. The Spotted sandpiper in contrast is polyandrous, with partly reversed sex roles. There was no seasonal trend from sons to daughters in this species. When tested together, the two species differed significantly as predicted by the hypothesis of adaptive sex ratio adjustment by females.
Sexual conflict in Sepsis cynipsea: female reluctance, fertility and mate choice
Authors: Hosken D. J. , Martin O. Y. , Born J. , Huber F.
Published: December 2004

Sexual conflict can elevate mating costs via male inflicted damage to females. Possible selective advantages to males include decreasing the likelihood that females remate and/or increasing females' current reproductive investment in a manner analogous to terminal reproductive investment. We investigated female mating behaviour relative to their number of previous copulations in the fly Sepsis cynipsea, and whether males accepted as first mates were more likely to be accepted again. Females were more likely to remate with new rather than original males, although there was no associated fitness benefit, and in contrast to theoretical predictions, females became less reluctant to remate as the number of previous copulations increased. Additionally, females did not increase reproductive investment as would be expected if they were ensuring their final reproductive efforts were maximized by remating. This suggests that damaging females is a pleiotropic effect which inadvertently leads to increased, not decreased, polyandry.
The emergence of cetaceans: phylogenetic analysis of male social behaviour supports the Cetartiodactyla clade
Authors: Lusseau D.
Published: December 2004

The phylogeny of cetaceans is still unresolved. Two hypotheses prevail for the position of cetaceans among ungulates. The first hypothesis shows that Artiodactyla is monophyletic and is sister taxon to a clade composed of cetaceans and mesonychians. The second one shows that Artiodactyla is paraphyletic and contains Cetacea that is sister taxon of Hippopotamida. These hypotheses are based on fossil records and molecular studies. The behaviour of extant species can provide as much phylogenetic information as other classical parameters. I considered the behaviour observed during male agonistic interactions in placental mammals in order to determine which of these hypotheses was supported by the behaviour of extant species. Headbutting was only observed in ruminants, hippopotamids and cetaceans, supporting the paraphyletic nature of Artiodactyla. Primitive ruminants (tragulids) and two genera of ruminants (Moschus and Oreamnos) were not observed headbutting. These secondary losses were only present in 6.25% of the 48 surveyed ruminant genera. Head-to-head attacks emerged in pigs, which have developed dermal protusions. Yet, these confrontations are not based on mutual blow delivery. The behavioural evidence supports the inclusion of cetaceans in Artiodactyla.
Mitochondrial differentiation in a polymorphic land snail: evidence for Pleistocene survival within the boundaries of permafrost
Authors: Haase M. , Misof B. , Wirth T. , Baminger H. , Baur B.
Published: December 2004

The genetic differentiation of populations having colonized formerly unsuitable habitats after the Pleistocene glaciations depends to a great extent on the speed of expansion. Slow dispersers maintain their refugial diversity whereas fast dispersal leads to a reduction of diversity in the newly colonized areas. During the Pleistocene, almost the entire current range of the land snail Arianta arbustorum has repeatedly been covered with ice or been subjected to permafrost. Owing to the low potential for dispersal of land snails, slow (re)colonization of the wide range from southern refugia can be excluded. Alternatively, fast, passive dispersal from southern refugia or survival in and expansion from multiple refugia within the area subjected to permafrost may account for the current distribution. To distinguish between these scenarios we reconstructed a phylogeography based on the sequences of a fragment of the cytochrome oxidase I from 133 individuals collected at 45 localities and analysed the molecular variance. Seventy-five haplotypes were found that diverged on average at 7.52% of positions. This high degree of diversity suggests that A. arbustorum is an old species in which the population structure, isolation and the hermaphroditic nature have reduced the probability of lineage extinction. The genetic structure was highly significant with the highest variance partition found among regions. Geographic distance and mitochondrial differentiation were not congruent. Lineages had overlapping ranges. The clear genetic differentiation and the patchy pattern of haplotype distribution suggest that colonization of formerly unsuitable habitats was mainly achieved from multiple populations from within the permafrost area.
Evolution of RNA virus in spatially structured heterogeneous environments
Authors: Cuevas J. M. , Moya A. , Elena S. F.
Published: December 2004

A hallmark of the infectious cycle for many RNA viruses parasitizing multicellular hosts is the need to invade and successfully replicate in tissues that comprise a variety of cell types. Thus, multicellular hosts represent a heterogeneous environment to evolving viral populations. To understand viral adaptation to multicellular hosts, we took a double approach. First, we developed a mathematical model that served to make predictions concerning the dynamics of viral populations evolving in heterogeneous environments. Second, the predictions were tested by evolving vesicular stomatitis virus in vitro on a spatially structured environment formed by three different cell types. In the absence of gene flow, adaptation was tissue-specific, but fitness in all tissues decreased with migration rate. The performance in a given tissue was negatively correlated with its distance to the tissue hosting the population. This correlation decreased with migration rate.
Examining costs of induced and constitutive immune investment in Tenebrio molitor
Authors: Armitage S. A. O. , Thompson J. J. W. , Rolff J. , Siva-Jothy M. T.
Published: December 2004

Central to the conceptual basis of ecological immunity is the notion that immune effector systems are costly to produce, run, and/or maintain. Using the mealworm beetle, Tenebrio molitor, as a model we investigated two aspects of the costs of innate immunity. We conducted an experiment designed to identify the cost of an induced immune response, and the cost of constitutive investment in immunity, as well as potential interactions. The immune traits under consideration were the encapsulation response and prophylactic cuticular melanization, which are mechanistically linked by the melanin-producing phenoloxidase cascade. If immunity is costly, we predicted reduced longevity and/or fecundity as a consequence of investment in either immune trait. We found a measurable longevity cost associated with producing an inducible immune response (encapsulation). In contrast to other studies, this cost was expressed under ad libitum feeding conditions. We found no measurable costs for constitutive investment in immunity (prophylactic investment in cuticular colour).
Chloroplast DNA indicates a single origin of the allotetraploid Arabidopsis suecica
Authors: Säll T. , Jakobsson M. , Lind-Halldén C. , Halldén C.
Published: December 2004

DNA sequencing was performed on up to 12 chloroplast DNA regions [giving a total of 4288 base pairs (bp) in length] from the allopolyploid Arabidopsis suecica (48 accessions) and its two parental species, A. thaliana (25 accessions) and A. arenosa (seven accessions). Arabidopsis suecica was identical to A. thaliana at all 93 sites where A. thaliana and A. arenosa differed, thus showing that A. thaliana is the maternal parent of A. suecica. Under the assumption that A. thaliana and A. arenosa separated 5 million years ago, we estimated a substitution rate of 2.9 × 10−9 per site per year in noncoding single copy sequence. Within A. thaliana we found 12 substitution (single bp) and eight insertion/deletion (indel) polymorphisms, separating the 25 accessions into 15 haplotypes. Eight of the A. thaliana accessions from central Sweden formed one cluster, which was separated from a cluster consisting of central European and extreme southern Swedish accessions. This latter cluster also included the A. suecica accessions, which were all identical except for one 5 bp indel. We interpret this low level of variation as a strong indication that A. suecica effectively has a single origin, which we dated at 20 000 years ago or more.
Sexual selection on morphological and physiological traits and fluctuating asymmetry in the yellow dung fly
Authors: Blanckenhorn W. U. , Kraushaar U. , Reim C.
Published: December 2004

Previous univariate studies of the yellow dung fly (Scathophaga stercoraria) have demonstrated strong sexual selection, in terms of mating success, on male size (estimated as hind tibia length). To identify specific target(s) of selection on body size and possible conflicting selection pressures on particular body parts, two multivariate field studies of sexual selection were conducted. In one study using point samples from three populations, we assessed several morphological traits, including genital traits and measures of fluctuating asymmetry (FA) of all paired traits. There was sexual selection for large male size in general, confirming previous, univariate studies. With the possible exception of thorax width, which was selected in the opposite direction, no main target of selection was identified, as most morphological traits were highly correlated. There was no detectable sexual selection on the male external genital structures assessed. In a second study using multiple samples from one population, we included physiological measures of energy reserves (lipids, glucose and glycogen) known to affect mating success, in addition to trait size and FA of wings and legs. Inclusion of physiological traits is rare in phenomenological studies of selection. This study again confirmed the mating advantage of large males, and additionally showed independent positive influences of lipid and glucose but not glycogen levels. FA in paired traits generally did not affect male mating success, but was negatively correlated with energy reserves. Our study suggests that inclusion of physiological measures and genital traits in phenomenological studies of selection would be fruitful in other species.
Structure and evolution of the horizontal septum in vertebrates
Authors: Gemballa S. , Hagen K. , Röder K. , Rolf M. , Treiber K.
Published: December 2004

Although the horizontal septum (HS) has been identified as playing a role in fish biomechanics and in path finding of cells during zebrafish development, its morphology is poorly known. However, it is generally regarded as an evolutionarily conserved structure. To test this idea, we applied a novel combination of techniques to analyse the HS of 35 species from all major gnathostome clades in which is visualized its collagen fibre architecture. Results show that the HS is a conserved trait only with respect to the presence of caudolateral [= epicentral] and craniolateral [= posterior oblique] collagen fibre tracts, but differs remarkably with respect to the specifications of these tracts. Our data revealed several evolutionary changes within vertebrates. In the gnathostome ancestor, the two tracts are represented by evenly distributed epicentral fibres (ECFs) and posterior oblique fibres (POFs). ECFs are condensed to distinct epicentral tendons (ECTs) in the actinopteran ancestor. POFs independently evolved to distinct posterior oblique tendons (POTs) at least two times within teleosts. Within basal teleostomes, POFs as well as ECFs or ECTs were lost two times independently. POTs were lost at least three times independently within teleosts. This view of a homoplastic HS remains stable regardless of the competing phylogenies used for analysis. Our data make problematic any generalization of biomechanical models on fish swimming that include the HS. They indicate that the pathfinding role of the HS in zebrafish may be extended to gnathostome fishes, but not to agnathans, sarcopterygian fishes and tetrapods.
Constant relative age and size at sex change for sequentially hermaphroditic fish
Authors: Allsop D. J. , West S. A.
Published: December 2004

A general problem in evolutionary biology is that quantitative tests of theory usually require a detailed knowledge of the underlying trade-offs, which can be very hard to measure. Consequently, tests of theory are often constrained to be qualitative and not quantitative. A solution to this problem can arise when life histories are viewed in a dimensionless way. Recently, dimensionless theory has been developed to predict the size and age at which individuals should change sex. This theory predicts that the size at sex change/maximum size (L50/Lmax), and the age at sex change/age at first breeding (τ/α) should both be invariant. We found support for these two predictions across 52 species of fish. Fish change sex when they are 80% of their maximum body size, and 2.5 times their age at maturity. This invariant result holds despite a 60 and 25 fold difference across species in maximum size and age at sex change. These results suggest that, despite ignoring many biological complexities, relatively simple evolutionary theory is able to explain quantitatively at what point sex change occurs across fish species. Furthermore, our results suggest some very broad generalities in how male fitness varies with size and age across fish species with different mating systems.
Male fitness of honeybee colonies (Apis mellifera L.)
Authors: Kraus F. B. , Neumann P. , Scharpenberg H. , Van Praagh J. , Moritz R. F. A.
Published: December 2004

Honeybees (Apis mellifera L.) have an extreme polyandrous mating system. Worker offspring of 19 naturally mated queens was genotyped with DNA microsatellites, to estimate male reproductive success of 16 drone producing colonies. This allowed for estimating the male mating success on both the colony level and the level of individual drones. The experiment was conducted in a closed population on an isolated island to exclude interferences of drones from unknown colonies. Although all colonies had produced similar numbers of drones, differences among the colonies in male mating success exceeded one order of magnitude. These differences were enhanced by the siring success of individual drones within the offspring of mated queens. The siring success of individual drones was correlated with the mating frequency at the colony level. Thus more successful colonies not only produced drones with a higher chance of mating, but also with a significantly higher proportion of offspring sired than drones from less successful colonies. Although the life cycle of honeybee colonies is very female centred, the male reproductive success appears to be a major driver of natural selection in honeybees.
Testing paleolimnological predictions with molecular data: the origins of Holarctic Eubosmina
Authors: Haney R. A. , Taylor D. J.
Published: December 2004

Zooplankton of the family Bosminidae have a unique paleolimnological record in many Holarctic lakes that provides a near continuous record of morphological change for thousands of years. If this morphological change could be interpreted reliably, then a rarely achieved direct observation of macroevolution would be feasible. We tested paleolimnological predictions derived from morphological variation found in the genus Eubosmina using mtDNA and nuclear DNA sequence variation from geographically distant Holarctic sites. The mtDNA and nDNA trees were congruent but genetic divergence was inversely associated with morphological divergence. The three most genetically divergent groups belonged to Eubosmina longispina, whose phylogeography and genetic divergence was consistent with glacial vicariance. The genetic evidence also supported the hypothesis that at least two Nearctic species were recent European introductions. Finally, the genetic evidence was consistent with paleolimnology in the finding of several proposed species undergoing rapid morphological evolution and being post-glacially derived from European E. longispina. The results suggested that lacustrine bosminids are susceptible to geographic speciation processes, and that morphological interpretation of diversity in paleolimnology can be markedly improved by genetic studies.
When to be born? Prolonged pregnancy or incubation enhances locomotor performance in neonatal lizards (Scincidae)
Authors: Shine R. , Olsson M.
Published: December 2004

The degree of offspring development at hatching (or birth) varies among species within most major vertebrate lineages; altricial vs. precocial birds offer the clearest example of a trade-off between early hatching and the degree of locomotor development of the hatchling. No such diversity has been reported for reptiles, but we suggest that natural selection may fine-tune the time of hatching (in oviparous species) or birth (in viviparous species) to optimize offspring phenotypes and hence, maximize fitness. This hypothesis predicts enhanced neonatal performance after more prolonged incubation or gestation, within as well as among populations. Both published and original data on Australian scincid lizards support this prediction. In a field study, viviparous alpine skinks (Niveoscincus microlepidotus) that gave birth later in the season had faster-running offspring, that had a higher probability of surviving through the first year of life. The enhanced performance and survival were not secondary results of larger offspring size. After controlling for effects of mean incubation temperature, prolonged development also correlated with enhanced locomotor performance in hatchlings from eggs of an oviparous skink (Bassiana duperreyi) incubated at warm temperatures (>20 °C) but not at cooler temperatures (<20 °C). We suggest that embryonic reptiles control their date of hatching or birth and thus, their stage of development at this critical life-history transition.
Weak phylogenetic effects on ecological niches of Sylvia warblers
Authors: Böhning-Gaese K. , Schuda M. D. , Helbig A. J.
Published: December 2004

To understand the evolution of ecological niches it is important to know whether niche evolution is constrained by phylogeny. We approached this question for Sylvia warblers by testing if closely related species are more similar in 20 ecologically relevant morphological traits than distantly related species. Phylogenetic relatedness was quantified using a molecular phylogeny based on the mitochondrial cytochrome b gene. By Principal Component Analysis (PCA) two major niche axes were extracted. We tested the individual ecomorphological traits and the positions of the species on the PCA axes for phylogenetic effects using Mantel tests. The results demonstrated small but significant phylogenetic effects only for the length of the middle toe, a trait probably correlated with locomotion. In general, however, phylogenetic effects were very weak. This suggests that ecological niches in passerine birds have the potential to evolve rapidly and are not subject to major phylogenetic constraints.
Costs of resistance: genetic correlations and potential trade-offs in an insect immune System
Authors: Cotter S. C. , Kruuk L. E. B. , Wilson K.
Published: December 2004

Theory predicts that natural selection will erode additive genetic variation in fitness-related traits. However, numerous studies have found considerable heritable variation in traits related to immune function, which should be closely linked to fitness. This could be due to trade-offs maintaining variation in these traits. We used the Egyptian cotton leafworm, Spodoptera littoralis, as a model system to examine the quantitative genetics of insect immune function. We estimated the heritabilities of several different measures of innate immunity and the genetic correlations between these immune traits and a number of life history traits. Our results provide the first evidence for a potential genetic trade-off within the insect immune system, with antibacterial activity (lysozyme-like) exhibiting a significant negative genetic correlation with haemocyte density, which itself is positively genetically correlated with both haemolymph phenoloxidase activity and cuticular melanization. We speculate on a potential trade-off between defence against parasites and predators, mediated by larval colour, and its role in maintaining genetic variation in traits under natural selection.
Divergent genetic and epigenetic post-zygotic isolation mechanisms in Mus and Peromyscus
Authors: Zechner U. , Shi W. , Hemberger M. , Himmelbauer H. , Otto S. , Orth A. , Kalscheuer V. , Fischer U. , Elango R. , Reis A. , Vogel W. , Ropers H. , Rüschendorf F. , Fundele R.
Published: December 2004

Interspecific hybridization in the rodent genera Peromyscus and Mus results in abnormal placentation. In the Peromyscus interspecies hybrids, abnormal allelic interaction between an X-linked locus and the imprinted paternally expressed Peg3 locus was shown to cause the placental defects. In addition, loss-of-imprinting (LOI) of Peg3 was positively correlated with increased placental size. As in extreme cases this placental dysplasia constitutes a post-zygotic barrier against interspecies hybridization, this finding was the first direct proof that imprinted genes may be important in speciation and thus in evolution. In the Mus interspecies hybrids, a strong role of an X-linked locus in placental dysplasia has also been detected. However, here we show by backcross and allele specific expression analyses that neither LOI of Peg3 nor abnormal interactions between Peg3 and an X-linked locus are involved in generating placental dysplasia in Mus hybrids, although the placental phenotypes observed in the two genera seem to be identical. In contrast to this, another dysgenesis effect common to Peromyscus and Mus hybrids, altered foetal growth, is caused at least in part by the same X-chromosomal regions in both genera. These findings first underline the strong involvement of the X-chromosome in the genetics of speciation. Secondly, they indicate that disruption of epigenetic states, such as LOI, at specific loci may be involved in hybrid dysgenesis effects in one group, but not in another. Thus, we conclude that even in closely related groups divergent molecular mechanisms may be involved in the production of phenotypically similar post-zygotic barriers against hybridization.
Within-clutch variation in offspring sex determined by differences in sire body size: cryptic mate choice in the wild
Authors: Calsbeek Ryan , Sinervo Barry
Published: December 2004

Sexual selection theory predicts that paternal quality should drive female investment in progeny. We tested whether polyandrous female side-blotched lizards, Uta stansburiana, would adjust within-clutch progeny investment according to sire phenotypes. In two different years, polyandrous females selectively used sperm from larger sires to produce sons and used sperm from smaller sires to produce daughters. This cryptic sperm choice had significant effects on progeny survival to maturity that were consistent with sexually antagonistic effects associated with sire body size. Large sires produced sons with high viability and small sires produced daughters with high viability. These results are consistent with our previous findings that alleles for male body size have different fitness effects in male and female progeny. Breeding experiments in the laboratory indicate that results from the wild are more likely due to female choice than biased sperm production by males. Our results demonstrate highly refined gender-specific female choice for sperm and indicate that sire body size may signal the quality of sons or daughters that a sire will produce.
Remating and sperm displacement in a natural population of Drosophila buzzatii inferred from mother–offspring analysis of microsatellite loci
Authors: Bundgaard J. , Barker J. S. F. , Frydenberg J. , Clark A. G.
Published: December 2004

Prospects for estimation of parameters of models of sperm competition from field data have improved recently with the development of methods that employ multilocus genotype data from brood-structured samples. Sperm competition in Drosophila buzzatii is of special interest because it is possible to directly observe the breeding behaviour of this species in its natural habitat of rotting cactus. Previous laboratory experiments showed that this species exhibits an unusual pattern of frequent remating and sperm partitioning. This paper reports the first attempt to estimate the frequency of female remating and sperm competition in natural populations of D. buzzatii. For the Australian population studied, the mean remating frequency was lower (α = 2.12–2.20) than previously estimated in laboratory experiments with the same population, whereas mean sperm displacement (β = 0.69–0.71) fell within the limits of previous laboratory results. The evolution of the D. buzzatii mating system is discussed.
Immunohistochemical Characteristics of Canine Aortic and Carotid Body Tumours
Authors: Brown P. J. , Rema A. , Gartner F.
Published: December 2004

In an immunohistochemical study of 25 canine chemodectomas, 17 tumours were stained with antisera to neurone specific enolase and the same number were stained for synaptophysin; a single tumour was stained for S100. Staining for Ki‐67 occurred in 18 cases; the Ki‐67‐labelling index and the intensity of immunostaining was increased in more pleomorphic and malignant tumours, as assessed on histological grounds. Immunohistochemistry did not aid in recognition of less well‐differentiated tumours.
Evaluation of a Commercially Available Enzyme‐Linked Immunosorbent Assay (ELISA) for the Determination of C‐Reactive Protein in Canine Serum
Authors: Kjelgaard‐Hansen M. , Kristensen A. T. , Jensen A. L.
Published: December 2004

The purpose of this study was to evaluate a commercially available enzyme‐linked immunosorbent assay for determination of canine serum C‐reactive protein (CRP). The concentration of CRP could be determined accurately and the intra‐ and inter‐assay coefficients of variation were in the range of 6.9–10.1 and 7.5–29.0%, respectively.

This level of imprecision between runs is usually considered unacceptable for diagnostic purposes, but the overall results indicated that the assay was useful in differentiating dogs suffering from infections, from dogs suffering from various other diseases (neoplastic diseases, endocrine/metabolic disorders), and healthy dogs. The assay was also able to detect dynamic changes of CRP during development and after cessation of spontaneous occuring inflammatory stimuli in two clinical cases.
Effects of Prenatal Stress on Corticosteroid Receptors and Monoamine Concentrations in Limbic Areas of Suckling Piglets(Sus scrofa)at Different Ages
Authors: Kanitz E. , Otten W. , Tuchscherer M. , Manteuffel G.
Published: December 2004

The present study was conducted in order to reveal the effects of prenatal stress on the central stress regulation in domestic pigs by measuring changes in corticosteroid receptor binding and monoamine concentrations in different limbic brain regions. Pregnant sows were subjected to a restraint stress for 5 min daily during the last 5 weeks of gestation. Maternal stress resulted in a significantly higher number of glucocorticoid receptors in the hippocampus, but decreased glucocorticoid receptors in the hypothalamus of the offspring at the first postnatal day. No alterations of hippocampal mineralocorticoid receptors were found. There was also no significant effect of prenatal stress on the brain monoamine concentrations. Prenatally stressed piglets showed lower basal plasma cortisol and increased corticosteroid binding globulin concentrations at the third postnatal day indicating decreased free cortisol concentrations after birth. Morbidity and mortality during the suckling period were significantly increased in prenatally stressed litters, as shown by a higher frequency of diseased and died piglets per litter. In conclusion, the results indicate that in pigs restraint stress during late gestation affects the ontogeny of the foetal neuroendocrine feedback system with consequences for the regulation of the hypothalamo‐pituitary‐adrenal function and the vitality of the offspring.
Induction of Apoptosis by Canine Natural Killer Cells
Authors: Schmitz G. , Armien A. G. , Fonfara S. , Teifke J. P. , Burkhardt E.
Published: December 2004

Besides a secretory pathway of canine natural killer (NK) cells, which results in necrosis of the target cell, a second pathway was demonstrated, which results in apoptosis of the target cell.

Comparing the Chromium Release Assay (CRA) and the Rose Bengal Assay (RBA) for quantification ofin vitrocanine NK cell activity, a constant 10% higher NK cell activity was found in the RBA compared with the CRA. To find out the mechanism responsible for the different results of both tests, morphological studies ofin vitrocanine NK cell activity against epithelial and mesenchymal allogenic target cell lines were performed. Most target cells were undergoing necrosis as a result of NK cell killing, which was evidenced by transmission electron microscopy. However, besides necrotic target cells, shrunken target cells with dense cytoplasm, fragmented nuclei and disruption into membrane‐bound bodies were detected, which are known as signs of apoptosis. Additionally, using the terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL) method, 13–23% of target cells presented a positive staining, indicative of apoptosis. These findings give evidence for the ability of canine NK cells to kill their target cells via two different pathways, which results either in apoptosis or necrosis.
Xylazine does not Induce Retrograde Flow of Spermatozoa into the Urinary Bladder of Sexually Rested Boars
Authors: Martin P. A. , Pineda M. H. , Dooley M. P.
Published: December 2004

The effect of xylazine on the retrograde flow of spermatozoa from their storage sites in the epididymides and vasa deferentia into the urinary bladder of sexually rested boars was examined. The bladder of four boars was evacuated through a surgically implanted urinary catheter and the urine was examined for the presence of spermatozoa. Boars were then given an injection of 2.2 mg of xylazine per kilogram of body weight and, immediately thereafter, 500 ml of saline was infused into the urinary bladder. Approximately 50 ml of the post‐treatment mixture of urine and saline, referred to as ‘urine’, was collected through the catheter at 5, 10, 15, 20, 30 and 45 min after the injection of xylazine, and examined immediately for the presence and motility of spermatozoa. At 60 min, the urinary bladder was evacuated and the remaining ‘urine’ was examined for the presence and motility of spermatozoa. None of the pre‐xylazine urine and post‐xylazine fractions of ‘urine’ had motile spermatozoa and xylazine did not increase (P > 0.1) the concentration and the number of spermatozoa in the post‐treatment ‘urine’. Thus, in contrast to other species, xylazine does not induce retrograde flow of spermatozoa into the urinary bladder of boars.
Succession in Gulf of Mexico Cold Seep Vestimentiferan Aggregations:  The Importance of Spatial Variability
Authors: Bergquist Derk C. , Andras Jason P. , McNelis Tim , Howlett Sarah , Van Horn Mark J. , Fisher Charles R.
Published: December 2004

Abstract. The slow rate of change in hydrocarbon seep communities on the upper ­Louisiana slope prevents the use of direct observation in studying successional trends. We used a chronosequence consisting of three presumed stages – juvenile, adult and senescent – to test a previous model which proposed that sulfide availability and vestimentiferan growth and physiological health decline over the lifespan of a vestimenti­feran aggregation. We replicated the chronosequence at two sites to simultaneously ­explore the influence of spatial heterogeneity on the characteristics of these communities. We determined environmental sulfide concentrations and vestimentiferan growth and condition in at least two vestimentiferan aggregations representative of each stage at each of these two sites. Hydrogen sulfide concentrations were highly variable both above and below the sediment's surface, and sulfide was present in high concentrations to sediment depths of 70 cm. Vestimentiferan growth and condition varied significantly on multiple spatial scales from sites separated by tens of kilometers, to aggregations separated by tens to hundreds of meters within a site, to individual vestimentiferans ­separated by tens of centimeters within an aggregation. The striking variability in both environmental sulfide and vestimentiferan growth and condition within individual ­aggregations suggests a crucial role for microhabitat variability in the persistence of vestimentiferan aggregations at these sites. Few significant successional trends in ­environmental sulfide or vestimentiferan growth and condition were found over the three stages tested.
Substrate Effects on the Bioeroding  Demosponge Cliona orientalis. 2. Substrate Colonisation and  Tissue Growth
Authors: H. L. Schönberg Christine
Published: December 2004

Abstract Sponge bioerosion is a result of tissue expansion of endolithic sponges in calcium carbonate substrates. The efficiency of erosion by the sponges can be affected by substrate features, which are thus also likely to influence the way in which the sponge will grow. A field experiment was conducted, in which sponge tissue was grafted to biogenic blocks cut from the corals Goniopora tenuidens, massive Porites sp., Astreopora listeri, Favites halicora, Favia pallida, Goniastrea retiformis and Cyphastrea serailia, and the clam Tridacna squamosa, to investigate colonisation capabilities and growth patterns of Cliona orientalis Thiele, 1900 after 9 months of the experiment.

C. orientalis is not substrate‐specific. It invaded > 90 % of the different substrate blocks and penetrated them to varying depths, but usually only down to slightly more than 1 cm. Lateral penetration clearly exceeded depth penetration. Enlargement of surface area versus restricted depth penetration benefits the symbiotic zooxanthellae located in the sponge's surface. Structural irregularities and barriers such as coral dissepiments temporarily deflected the direction of tissue growth and created characteristic tissue patch patterns in different substrates. Tissue growth may be more pronounced in substrates of higher density and lower pore volume, but evidence was only slight. Protection against predation is better in denser materials, which may stimulate the sponge's tissue growth especially in shallower substrate depth. In more porous substrates, favoured by grazers and corallivores, relatively more tissue was located in deeper layers.
Orofacial Conidiobolomycosis due to Conidiobolus incongruus
Authors: Sharma N. L. , Mahajan V. K. , Singh P.
Published: December 2004

We report here a patient of orofacial conidiobolomycosis presenting with classical centrofacial distribution described typically for Conidiobolus coronatus infection. The culture, however, showed C. incongruus. The mode of infection and its possible correlation with patient's occupation is also discussed.
A case of subcutaneous phaeohyphomycotic cyst due to Exophiala jeanselmei complicated with systemic lupus erythematosus
Authors: Murayama N. , Takimoto R. , Kawai M. , Hiruma M. , Takamori K. , Nishimura K.
Published: December 2004

We report a case of subcutaneous phaeohyphomycosis by Exophiala jeanselmei that appeared on the extensor surface of the left lower leg of a 34‐year‐old woman with systemic lupus erythematosus (SLE). The superficial symptoms were a subcutaneous nodule 2.5 × 2 cm in size discharging a serous exudate from its center. Histopathological examination revealed granulomatous changes including large numbers of neutrophils in the dermis and the subcutaneous tissues. In addition, periodic acid‐Schiff‐positive fungal elements consisting of many yeast‐like cells and chains of cells with hyphae were seen. The statistics on E. jeanselmei infections in Japan indicated that 54 cases (24 in men and 30 in women) had been reported, of which 50 (21 in men and 29 in women) were phaeohyphomycosis, and about half had underlying diseases; and the sites of the lesions were mainly on the extremities.
Inhibition of dermatophytes by optical brighteners
Authors: Brasch J. , Kreiselmaier I. , Christophers E.
Published: December 2004

The aim of this study was to investigate a possible effect of optical brighteners on the growth of dermatophytes. Typical strains of Trichophyton rubrum, T. mentagrophytes, Microsporum canis and Epidermophyton floccosum were grown on agar plates containing two different brighteners of stilbenedisulfonic acid type in concentrations between 5 × 10−5 and 1 × 10−2 mol l−1 and their thallus diameters were compared with controls. In addition, hyphae grown with brighteners were compared with controls by fluorescence microscopy and by transmission electron microscopy. Both brighteners had a significant dose‐dependent growth‐suppressive effect on all dermatophytes tested, that was complete at a concentration of 10−2 and 10−3 mol l−1, respectively. Fluorescence microscopy of hyphae showed a pronounced fluorescence of the septal areas and a less‐intense staining of the outer cell walls. Electron microscopy revealed a marked thickening and blurred contours of the cell walls grown with brighteners. These new observations relate very well to an interference of optical brighteners with the formation of normal chitin fibrils as described previously. Optical brighteners of stilbenedisulfonic acid type may be rewarding objects for the development of new antifungal agents.
Cryptococcal meningitis in pediatric systemic lupus erythematosus
Authors: Liou J. , Chiu C. , Tseng C. , Chi C. , Fu L.
Published: December 2004

Cryptococcal meningitis is an uncommon but often fatal complication of systemic lupus erythematosus (SLE). We report on a 13‐year‐old girl with SLE using high‐dose prednisolone for several months, presented to us with low grade fever, intermittent vomiting and headache. Physical examination, including papilloedema and meningeal irritation, was unremarkable. Serum and cerebrospinal fluid (CSF) cryptococcal antigen titer was 1 : 128 by latex agglutination method. CSF culture yielded Cryptococcus neoformans. We used amphotericin B deoxycholate (a cumulative dose of 1.95 gm) and fluconazole (200 mg day−1) for 6 weeks. Clinical response was good. Then, we continued fluconazole 200 mg per qd as suppressive therapy for thirty‐four months. There were no neurological sequelae or relapse after 20‐month follow‐up. Timely diagnosis and effective antifungal therapy could improve the prognosis of cryptococcal meningitis in SLE patients.