bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fate-Mapping Technique: Targeted Whole-Embryo Electroporation of DNA Constructs into the Germ Layers of Mouse Embryos 7-7.5 Days Post-coitum
Authors: Khoo P.-L. , Franklin V.J. , Tam P.P.L. 
Published: November 2007

INTRODUCTIONFate maps reveal body plan organization and presage the expression of molecular characteristics of cell lineages and formation of body parts. This protocol targets DNA expression constructs into the germ layers of gastrula-stage mouse embryos by focal electroporation. Plasmids utilizing a promoter that drives widespread, non-lineage-restricted expression of transgenes are introduced to cells in defined germ layer regions by whole-embryo electroporation. Germ-layer cells are exposed to the DNA by microinjecting the plasmids into the proamniotic cavity (ectoderm) or directly into the intercellular space of the mesenchyme (mesoderm), or by incubating the embryo in the DNA solution (endoderm). Electroporation is performed on whole embryos in vitro by electric current-mediated permeation of the cell membrane, which allows DNA adsorbed to cell surfaces to enter the cells. A point electrode is used to focus the electric field to the intended site of electroporation and a plate electrode is used to generate the current at an effective voltage low enough to minimize damage to the embryonic tissue. Expression of the transgene can be used to track the fate and movement of cells and the cDNA to study the functional consequences of overexpression of genes during embryonic development in vitro.
Combined Flow Cytometric Measurement of Two Cell-Surface Antigens and DNA-RNA Content: Figure 1.
Authors: Schmid Ingrid 
Published: November 2007

INTRODUCTIONFlow cytometry is frequently used to assess nucleic acid content in individual cells. Based on DNA content alone, however, cells in the quiescent G0 phase cannot be discriminated from cells in the proliferative G1 phase, as DNA content remains constant until S-phase entry. In contrast, by measuring RNA content in addition to DNA content, cells can be assigned to G0 and cell-cycle subcompartments of G1. Assessing phenotype at the same time as nucleic acid content allows determination of the cell-cycle status of subpopulations in mixed-cell preparations. This protocol describes an optimized method for combining dual-color cell-surface immunofluorescent staining with staining for DNA-RNA, adapted for a basic dual-laser flow cytometer with blue (488-nm) and red (633- or 647-nm) excitation. DNA is stained at low pH in the presence of saponin with 7-aminoactinomycin D (7-AAD), and RNA is stained with pyronin Y (PY). Both dyes are used at low concentration, and 7-AAD is exchanged with nonfluorescent actinomycin D to minimize fluorochrome-fluorochrome interactions, which can negatively affect detection of cell-surface antigen staining.
Imaging Real-Time Gene Expression in Living Systems with Single-Transcript Resolution: Construct Design and Imaging System Setup
Authors: Wells Amber L. , Condeelis John S. , Singer Robert H. , Zenklusen Daniel 
Published: November 2007

INTRODUCTIONThe most common way for a cell to respond to internal and external signals is to change its gene expression pattern. This requires the synchronization of regulatory steps along the expression pathway. Biological imaging techniques can be used to visualize and measure such processes in individual live cells in real time. This article discusses the use of a fluorescent RNA-binding protein system that allows real-time analysis of gene expression with single-transcript resolution.
Genetic diversity and population structure of indigenous yellow cattle breeds of China using 30 microsatellite markers
Authors: Zhang G. X. , Wang Z. G. , Chen W. S. , Wu C. X. , Han X. , Chang H. , Zan L. S. , Li R. L. , Wang J. H. , Song W. T. , Xu G. F. , Yang H. J. , Luo Y. F. 
Published: November 2007

SummaryTwenty‐seven domesticated yellow cattle breeds of China and three introduced cattle breeds were analysed by means of 30 microsatellite markers to determine the level of genetic variation within and among populations as well as the population structure. In all, 480 microsatellite alleles were observed across the 30 breeds with the mean number of alleles per locus of 9.093 for native breeds and 6.885 for the three introduced breeds. Mean F‐statistics (0.08) for Chinese native cattle breeds implied that 92% of the total genetic variation was from genetic differentiation within each breed and 8% of the genetic variation existed among breeds. A phylogenetic tree was constructed based on Nei's genetic distances, and three clusters were obtained. According to the tree, the three introduced breeds were distinct from the 27 native breeds. The indigenous cattle breeds were divided into two clusters, one cluster including five humpless breeds and the other cluster containing 22 humped breeds. This study identifies multiple origins of yellow cattle of China from Bos taurus and Bos indicus. Furthermore, population structure analysis implies that there are possibly five independent original domestications for yellow cattle in China. Four of five origins were four different Bos indicus types, mainly in areas of the Chang Jiang, the Zhu Jiang River basin, the Yellow River and the Huai River basin. The other origin was for Bos taurus type of Mongolian descent, mainly located in Northwestern China, the Mongolian plateau and Northeastern China or north of the Great Wall.
Anti‐myeloperoxidase and anti‐cathepsin G antibodies in sulphonamide hypersensitivity
Authors: Lavergne S. N. , Drescher N. J. , Trepanier L. A. 
Published: November 2007

SummaryBackgroundAnti‐neutrophil cytoplasmic antibodies (ANCA) are associated with vasculitis in humans. Sulphonamide antimicrobials cause drug hypersensitivity (HS) reactions with some clinical signs that are suggestive of vasculitis.ObjectiveThe purpose of this study was to determine whether sulphonamide HS is associated with anti‐neutrophil antibodies, using the dog as a spontaneous clinical model.MethodsThirty‐four sulphonamide‐HS dogs, 11 sulphonamide‐‘tolerant’ dogs, and nine healthy sulphonamide‐naïve dogs were evaluated for anti‐neutrophil antibodies using a commercial ELISA against human myeloperoxidase (MPO), a commercial human ANCA Western blot protocol, and immunoblotting against whole canine neutrophils.ResultsUsing ELISA, anti‐MPO antibodies were found with an apparent higher frequency in HS dogs (50%), compared with ‘tolerant’ dogs (18%), which also showed significantly lower absorbances. Among HS dogs, anti‐MPO antibodies were significantly more common, with significantly higher absorbances, in dogs that did not survive the HS reaction (78%) compared with survivors (35%). Using immunoblotting, ANCA were detected with similar overall frequencies in HS and ‘tolerant’ dogs. However, one protein targeted by several HS dogs, but no ‘tolerant’ dogs, was identified as cathepsin G.ConclusionThese data indicate that anti‐MPO antibodies and anti‐cathepsin G antibodies are associated with sulphonamide HS. Anti‐MPO antibodies have been shown to be pathogenic bothin vitroandin vivo, leading to vasculitis lesions and vasculitis‐like syndromes. The present study therefore suggests that vasculitis might be one mechanism of tissue damage in this sulphonamide HS. Furthermore, the evaluation of ANCA, and its relationship to disease severity and clinical outcome, should be considered in human patients with sulphonamide drug HS.
Relationship between early intestinal colonization, mucosal immunoglobulin A production and systemic immune development
Authors: Martino D. J. , Currie H. , Taylor A. , Conway P. , Prescott S. L. 
Published: November 2007

SummaryBackground
Variations in early intestinal colonization patterns have been implicated in the predispostion to allergic disease through effects on mucosal and systemic immune function.Methods
Colonization patterns and mucosal IgA production at 6 months of age were examined in relation to early exposures, systemic immune development and early allergic outcomes. This was performed in a cohort (n=189) who had received either Lactobacillus acidophilus or a placebo since birth.Results
Children who developed sensitization to one or more allergens by 12 months of age had significantly higher total (but not secretory) IgA levels at 6 months (P=0.024), but this was independent of probiotic treatment. There were no relationships between colonization patterns and IgA (total or secretory IgA) levels or allergic outcomes (sensitization, atopic dermatitis or food allergies). Breastfeeding, and the use of yoghurt or probiotic supplements were independently associated with significantly higher proportions of ‘favourable’ lactobacilli and bifidobacteria species. Caesarean delivery and the use of antibiotics during the first 6 months were not associated with significant variations in colonization. Higher proportions of ‘favourable’ bacteria (notably bifidobacteria) were associated with reduced production of most cytokine response to allergens, but increased expression of regulatory cell markers (P=0.009) and transforming growth factor‐β (P=0.016).Conclusion
‘Favourable’ colonization, particularly with bifidobacteria, was associated with effects on cellular immune function, but this was not associated with mucosal immunity (secretory IgA) or reduced risk of allergic disease.
Effect of stress on basophil function in chronic idiopathic urticaria
Authors: Dyke S. M. , Carey B. S. , Kaminski E. R. 
Published: November 2007

SummaryBackground
Chronic idiopathic urticaria (CIU) is a distressing skin condition involving recurrent itchy hives lasting 6 weeks or longer. The mechanism involves mast cell and basophil degranulation, which releases inflammatory mediators including histamine. In our clinical practice, we have observed that the onset of CIU is often preceded by a major life event.Objective
To investigate the role of the hormones of the hypothalamic–pituitary–adrenal (HPA) axis in the link between psychological stress and CIU.Methods
Thirty people with CIU and 30 normal controls were recruited. A flow cytometric CD63 expression assay was used to quantify basophil activation, and serum cortisol concentrations were measured as an indication of stress.Results
Both corticotrophin releasing factor (CRF) and adrenocorticotrophic hormone (ACTH) were shown to activate basophils. There was no significant difference between numbers of CIU patients and normal controls responding to CFR, ACTH or cortisol. However, the responses in the CIU patients were stronger than those in normal controls. There was also a trend towards higher serum cortisol concentrations in CIU patients. The basophil response to CRF and ACTH correlated with the serum cortisol concentration in normal controls, but not in CIU patients.Conclusions
Although our data have not supported the hypothesis that stress makes a major contribution to CIU, the heightened basophil response to CFR and ACTH and higher levels of serum cortisol do suggest a derangement of the HPA axis in CIU.
Beta‐sitosterolaemia: a new nonsense mutation in the ABCG5 gene
Authors: Mannucci L. , Guardamagna O. , Bertucci P. , Pisciotta L. , Liberatoscioli L. , Bertolini S. , Irace C. , Gnasso A. , Federici G. , Cortese C. 
Published: November 2007

AbstractBackground  Sitosterolaemia is a rare autosomal recessive disorder characterised by elevated plasma levels of plant sterols and cholesterol. Sitosterolaemia is caused by gene mutations in either of two ATP‐binding cassette (ABC) half transporters, ABCG5 and ABCG8. The plasma sterol profile and genetic analysis of a 10‐year‐old girl who had tuberous xanthomas is the subject of this report.Materials and methods  Genomic DNA was isolated from white blood cells from the proband, her family and a control group of healthy people. All exons of ABCG5 and ABCG8 were sequenced. Plasma cholesterol and triglycerides were measured by routine methods. All other plasma sterols were measured by Gas Chromatography coupled to Mass Spectrometry.Results  The proband was found to be homozygous for a single nucleotide mutation in exon 10 of the ABCG5 gene, consisting of a C to T transition at nucleotide 1336 of the coding sequence, which results in the premature termination of the ABCG5 protein at amino acid 446 (Arg446X). Her mother and brother were also homozygous for the same mutation and all had elevated plasma beta‐sitosterol levels. The father was heterozygous and showed normal beta‐sitosterol levels. This mutation was not found in healthy normolipidaemic subjects.Conclusions  We describe a novel nonsense mutation in exon 10 of the ABCG5 gene in a 10‐year‐old girl showing clinical and biochemical features of sitosterolaemia. This family study broadens the spectrum of the ABCG5/ABCG8 mutations causing sitosterolaemia and helps highlight the correlations between such gene mutations, biochemical phenotype and the development of cardiovascular disease.
Declining trends in conception rates in recent birth cohorts of native Danish women: a possible role of deteriorating male reproductive health
Authors: Jensen Tina Kold , Sobotka Tomáš , Hansen Martin A. , Pedersen Anette Tønnes , Lutz Wolfgang , Skakkebæk Niels E. 
Published: November 2007

SummaryRecent findings of poor semen quality among at least 20% of normal young men in Denmark prompted us to use unique Danish registers on births and induced abortions to evaluate a possible effect of the poor male fecundity on pregnancy rates among their presumed partners – the younger cohorts of women. We have analysed data from the Danish birth and abortion registries as well as the Danish registry for assisted reproduction (ART) and defined a total natural conception rate (TNCR), which is equal to fertility rate plus induced abortion rate minus ART conception rate. A unique personal identification number allowed the linkage of these databases. Our database included 706 270 native Danish women born between 1960 and 1980. We used projections to estimate the fertility of the later cohorts of women who had not yet finished their reproduction. We found that younger cohorts had progressively lower TNCR and that in terms of their total fertility rate, the declining TNCR is compensated by an increasing use of ART. Our hypothesis of an ongoing birth cohort‐related decline in fecundity was also supported by our finding of increasing and substantial use of ART in the management of infertility of relatively young couples in the later cohorts. Furthermore, the lower rates of induced abortion among the younger birth cohorts, often viewed as a success of health education programs, may not be fully explained by improved use of contraception. It seems more likely that decreased fecundity because of widespread poor semen quality among younger cohorts of otherwise normal men may explain some of the observed decline in conception rates. This may imply increasing reproductive health problems and lower fertility in the future, which is difficult to reverse in the short term. The current and projected widespread use of ART in Denmark may be a sign of such an emerging public health problem.
The restoration of ecological interactions: plant–pollinator networks on ancient and restored heathlands
Authors: Forup Mikael Lytzau , Henson Kate S. E. , Craze Paul G. , Memmott Jane 
Published: November 2007

Summary

Attempts to restore damaged ecosystems usually emphasize structural aspects of biodiversity, such as species richness and abundance. An alternative is to emphasize functional aspects, such as patterns of interaction between species. Pollination is a ubiquitous interaction between plants and animals. Patterns in plant–pollinator interactions can be analysed with a food web or complex‐systems approach and comparing pollination webs between restored and reference sites can be used to test whether ecological restoration has taken place.
Using an ecological network approach, we compared plant–pollinator interactions on four pairs of restored and ancient heathlands 11 and 14 years following initiation of restoration management. We used the network data to test whether visitation by pollinators had been restored and we calculated pollinator importance indices for each insect species on the eight sites. Finally, we compared the robustness of the restored and ancient networks to species loss.
Plant and pollinator communities were established successfully on the restored sites. There was little evidence of movement of pollinators from ancient sites onto adjacent restored sites, although paired sites correlated in pollinator species richness in both years. There was little insect species overlap within each heathland between 2001 and 2004.
A few widespread insect species dominated the communities and were the main pollinators. The most important pollinators were typically honeybees (Apis mellifera), species of bumblebee (Bombus spp.) and one hoverfly species (Episyrphus balteatus). The interaction networks were significantly less complex on restored heathlands, in terms of connectance values, although in 2004 the low values might reflect the negative relationship between connectance and species richness. Finally, there was a trend of restored networks being more susceptible to perturbation than ancient networks, although this needs to be interpreted with caution.
Synthesis and applications. Ecological networks provide a powerful tool for assessing the outcome of restoration programmes. Our results indicate that heathland restoration does not have to occur immediately adjacent to ancient heathland for functional pollinator communities to be established. Moreover, in terms of restoring pollinator interactions, heathland managers need only be concerned with the most common insect species. Our focus on pollination demonstrates how a key ecological service can serve as a yardstick for judging restoration success.
Do small mammals avoid roads because of the traffic?
Authors: McGregor Rachelle L , Bender Darren J , Fahrig Lenore 
Published: November 2007

Summary

Roads can act as barriers to animal movement, which may reduce population persistence by reducing recolonization of empty habitats and limiting immigration. Appropriate mitigation of this barrier effect (e.g. seasonal road closures, location and design of wildlife over‐ or underpasses) depends upon whether the animals avoid the road itself or the traffic on the road. Empirical studies of road avoidance to date do not generally differentiate between these.
We conducted short‐ and long‐distance translocations and trapping studies of white‐footed mice (Peromyscus leucopus) and eastern chipmunks (Tamias striatus) near two‐lane paved roads, which differed widely in traffic amount, from 47 to 15 433 vehicles per day.
In the trapping study (13 sites) only five animals moved across a road, in comparison to 36 animals that moved the same distance without an intervening road (P < 0·0001). In the short‐distance translocations (15 sites), 51% of the small mammals that were translocated across roads returned, in comparison to a return rate of 77% of animals that were translocated a similar distance with no intervening road (P = 0·009).
In the long‐distance translocation study (24 sites) we found that each intervening road reduced the probability of successful return by about 50%.
We found no significant effects of traffic amount on return rates in either the short‐distance or the long‐distance translocations studies.
Small mammal densities were not lower near roads and we found no evidence for a decrease in density near roads with increasing traffic amount.
Synthesis and applications. Our results suggest that small mammals avoid the road itself, and not emissions such as noise from the traffic on the roads. Our results imply that the barrier effect of roads on these species cannot be mitigated by measures aimed at reducing traffic amount; other measures such as wildlife passages would be needed.
Land‐use change and subalpine tree dynamics: colonization of Larix decidua in French subalpine grasslands
Authors: Albert Cécile H. , Thuiller Wilfried , Lavorel Sandra , Davies Ian D. , Garbolino Emmanuel 
Published: November 2007

Summary

In many places in Europe, trees are currently far below their theoretical altitudinal limit because of past land use. However, under the current crisis affecting mountain agriculture, trees are likely to recolonize the subalpine belt. Addressing the societal issues associated with such landscape change requires predictive tools to assess vegetation dynamics in relation to management strategies. This study aims to analyse the factors determining tree dynamics at the subalpine ecotone and to evaluate the impact of land‐use change on landscape vegetation patterns.
We developed a hierarchical scaling approach and applied it to a European larch (Larix decidua Mill.) colonization in the French Alps. Our landscape case study focused on subalpine south‐facing grasslands of Villar d’Arêne (France). First, we used a habitat‐suitability model to delineate the climatic suitability habitats of larch in the French Alps. Then we used a landscape model (LaMoS) to determine whether larch is able to colonize these grasslands predicted to be climatically suitable, considering land use and local vegetation. The sensitivity of landscape colonization patterns to land‐use scenarios (abandonment, delayed mowing or traditional mowing) and biological attributes of larch were analysed with a factorial simulation experiment.
The accuracy of the habitat‐suitability model at the French Alps scale allowed for the prediction that the grasslands of Villar d’Arêne were highly suitable for larch.
Simulations highlighted the effect of land use on larch establishment at the local but not at the landscape scale. On the other hand, larch attributes such as dispersal capacity, juvenile tolerance to light interaction (competition and facilitation) and its capacity to survive on infertile soil were shown as essential for tree spatial dynamics.
Synthesis and applications. Combining a habitat‐suitability model with a spatially and temporally explicit landscape model enhances the capacity to account for environmental factors acting at different overlapping scales. This modelling strategy increases the robustness and accuracy of predictions, a prerequisite for landscape management in a global change context. We conclude that ongoing and future agri‐environmental policies have to be quickly adapted to protect biodiversity and ecosystem services provided by subalpine grasslands.