bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potato virus X: structure, disassembly and reconstitution
Authors: ATABEKOV JOSEPH , DOBROV EUGEN , KARPOVA OLGA , RODIONOVA NINA 
Published: July 2007

SUMMARYThis paper summarizes some structural characteristics of Potato virus X (PVX), the flexuous filamentous plant potexvirus. A model of PVX coat protein (CP) tertiary structure in the virion proposed on the basis of tritium planigraphy combined with predictions of the protein tertiary structure is described. A possible role of glycosylation and phosphorylation in the CP structure and function is discussed. Two forms of PVX virion disassembly are discussed: (i) the virion co‐translational disassembly after PVX CP in situ phosphorylation and (ii) disassembly of PVX triggered by different factors after linear destabilization of the virion by binding of the PVX‐coded movement protein (TGBp1) to one end of the polar CP‐helix. Special emphasis was placed on a translational activation of encapsidated PVX RNA and rapid disassembly of TGBp1‐PVX complexes into free RNA and CP. The results of experiments on the PVX CP repolymerization and PVX reconstitution are considered. In particular, the products assembled from PVX RNA, CP and TGBp1 were examined. Single‐tailed particles were found with a helical, head‐like structure consisting of helically arranged CP subunits located at the 5′‐tail of RNA; the TGBp1 was bound to the end of the head. Translatable ‘RNA‐CP‐TGBp1’ complexes may represent the transport form of the PVX infection.
The histidine kinase CpHK2 has impact on spore germination, oxidative stress and fungicide resistance, and virulence of the ergot fungus Claviceps purpurea
Authors: NATHUES EVA , JÖRGENS CORDULA , LORENZ NICOLE , TUDZYNSKI PAUL 
Published: July 2007

SUMMARYHistidine kinases are important mediators for adaptation of bacteria and plants to environmental signals. Genome analyses of filamentous fungi have revealed the presence of a high number of potential hybrid histidine kinase (HK)‐encoding genes; the role of most of these potential sensors is so far unclear, though some members of the class III histidine kinases were shown to be involved in osmostress responses. Here we present a functional analysis of cphk2, a histidine kinase‐encoding gene in the biotrophic grass pathogen Claviceps purpurea. The putative product of cphk2 (CpHK2) was shown to group within family X of fungal HKs and it had high homology to the oxidative stress sensors SpMAK2/3 of Schizosaccharomyces pombe. Analysis of a cphk2 deletion mutant indicated that this histidine kinase is involved in spore germination, sensitivity to oxidative stress and fungicide resistance. In addition, virulence of the Dcphk2 mutant on rye was significantly reduced compared with the wild‐type strain, even if the conidial titre was adjusted to the lower germination rate. This is the first report of a role for a class X histidine kinase in a filamentous fungus.
Recent progress in the development of RNA interference for plant parasitic nematodes
Authors: LILLEY CATHERINE J. , BAKHETIA MANJULA , CHARLTON WAYNE L. , URWIN PETER E. 
Published: July 2007

SUMMARYRNA interference (RNAi), first described for Caenorhabditis elegans, has emerged as a powerful gene silencing tool for investigating gene function in a range of organisms. Recent studies have described its application to plant parasitic nematodes. Genes expressed in a range of cell types are silenced when preparasitic juvenile nematodes take up double‐stranded (ds)RNA that elicits a systemic RNAi response. Important developments over the last year have shown that in planta expression of a dsRNA targeting a nematode gene can successfully induce silencing in parasitizing nematodes. When the targeted gene has an essential function, a resistance effect is observed paving the way for the potential use of RNAi technology to control plant parasitic nematodes.
A meta‐analysis of the association between Caesarean section and childhood asthma
Authors: Thavagnanam S. , Fleming J. , Bromley A. , Shields M. D. , Cardwell C. R. 
Published: July 2007

SummaryBackground
Children born by Caesarean section have modified intestinal bacterial colonization and consequently may have an increased risk of developing asthma under the hygiene hypothesis. The results of previous studies that have investigated the association between Caesarean section and asthma have been conflicting.Objective
To review published literature and perform a meta‐analysis summarizing the evidence in support of an association between children born by Caesarean section and asthma.Methods
MEDLINE, Web Science, Google Scholar and PubMed were searched to identify relevant studies. Odds ratio (OR) and 95% confidence interval (CI) were calculated for each study from the reported prevalence of asthma in children born by Caesarean section and in control children. Meta‐analysis was then used to derive a combined OR and test for heterogeneity in the findings between studies.Results
Twenty‐three studies were identified. The overall meta‐analysis revealed an increase in the risk of asthma in children delivered by Caesarean section (OR=1.22, 95% CI 1.14, 1.29). However, in this analysis, there was evidence of heterogeneity (I2=46%) that was statistically significant (P<0.001). Restricting the analysis to childhood studies, this heterogeneity was markedly decreased (I2=32%) and no longer attained statistical significance (P=0.08). In these studies, there was also evidence of an increase (P<0.001) in the risk of asthma after Caesarean section (OR=1.20, 95% CI 1.14, 12.6).Conclusion
In this meta‐analysis, we found a 20% increase in the subsequent risk of asthma in children who had been delivered by Caesarean section.
Distinctive immunoglobulin E anti‐house dust allergen‐binding specificities in a tropical Australian Aboriginal community
Authors: Hales B. J. , Laing I. A. , Pearce L. J. , Hazell L. A. , Mills K. L. , Chua K. Y. , Thornton R. B. , Richmond P. , Musk A. W. , James A. L. , LeSouëf P. N. , Thomas W. R. 
Published: July 2007

SummaryBackground
There is evidence that the specificity of the IgE binding in allergy tests can vary for different populations.Objective
We aimed to examine the allergenic specificity of IgE binding in sera from house dust mite (HDM)‐atopic subjects in a tropical Australian Aboriginal community.Methods
Sera shown to contain IgE antibodies to an HDM extract of Dermatophagoides pteronyssinus were examined for IgE binding to a panel of nine purified HDM allergens from this mite species by quantitative microtitre assays. IgG antibody binding (IgG1 and IgG4) was also measured.Results
The IgE‐binding activity in the sera from the Aboriginal community was not directed to the expected major groups 1 and 2 HDM allergens but instead to the group 4 amylase allergen. There was also little IgE binding to the potentially cross‐reactive tropomyosin (Der p 10) or arginine kinase (Der p 20) allergens. The IgG4 antibody was rarely detected and limited to the Der p 4 allergen. IgG1 antibody binding was frequently measured to all the allergens regardless of an individual's atopic status, whereas in urban communities it is restricted to the major allergens and to atopic subjects.Conclusion
The high IgE anti‐HDM response of Australian Aboriginals predominantly bound Der p 4 and not the Der p 1 and 2 allergens, showing a distinctive allergy that could affect the disease outcome and diagnosis.
The expression pattern of MUC1 (EMA) is related to tumour characteristics and clinical outcome in ‘pure’ ductal carcinoma in situ of the breast
Authors: De Roos M A J , Van Der Vegt B , Peterse J L , Patriarca C , De Vries J , De Bock G H , Wesseling J 
Published: July 2007

Aims:  To classify MUC1 according to five predefined expression patterns in ductal carcinoma in situ (DCIS) and related clinicopathological parameters, coexpression of other biological markers and prognosis.Methods and results:  With a manual tissue arrayer, 92% (n = 80) of the 87 DCIS samples were successfully targeted. Immunohistochemistry was carried out for MUC1, oestrogen receptor (ER), progesterone receptor (PR), Her2/Neu, p53 and cyclin D1. Entire membrane expression was related to Her2/neu negativity (P =0.042). Apical membrane expression was associated with low grade (P = 0.027), Her2/neu negativity (P = 0.014) and PR positivity (P = 0.005). Focal cytoplasmic expression was related to high grade (P = 0.006). Diffuse cytoplasmic expression was associated with high grade (P = 0.004), large tumour size (P = 0.046), Her2/neu positivity (P =0.042) and cyclin D1 positivity (P = 0.002). On the basis of these analyses the four patterns were reclassified as membranous or cytoplasmic expression. On multivariate analysis, cytoplasmic MUC1 expression (hazard ratio 8.5, 95% confidence interval 1.0, 73.0; P = 0.04) was the only independent predictor of local recurrence.Conclusions:  Four patterns of MUC1 expression are recognized in DCIS that suggest a relationship to functional differentiation and can be simplified into two types that are clinically relevant and could therefore be helpful in the distinction between different subgroups of DCIS.
The expression pattern of MUC1 (EMA) is related to tumour characteristics and clinical outcome of invasive ductal breast carcinoma
Authors: Van Der Vegt B , De Roos M A J , Peterse J L , Patriarca C , Hilkens J , De Bock G H , Wesseling J 
Published: July 2007

Aims:  To clarify MUC1 patterns in invasive ductal breast carcinoma and to relate them to clinicopathological parameters, coexpression of other biological markers and prognosis.Methods and results:  Samples from 243 consecutive patients with primary ductal carcinoma were incorporated into tissue microarrays (TMAs). Slides were stained for MUC1, oestrogen receptor (ER), progesterone receptor (PR), Her2/neu, p53 and cyclin D1. Apical membrane MUC1 expression was associated with smaller tumours (P = 0.001), lower tumour grades (P < 0.001), PR positivity (P = 0.003) and increased overall survival (OS; P = 0.030). Diffuse cytoplasmic MUC1 expression was associated with cyclin D1 positivity (P = 0.009) and increased relapse‐free survival (RFS; P = 0.034). Negativity for MUC1 was associated with ER negativity (P = 0.004), PR negativity (P = 0.001) and cyclin D1 negativity (P = 0.009). In stepwise multivariate analysis MUC1 negativity was an independent predictor of both RFS [hazard ratio (HR) 3.5, 95% confidence interval (CI) 1.5, 8.5; P = 0.005] and OS (HR 14.7, 95% CI 4.9, 44.1; P < 0.001).Conclusions:  The expression pattern of MUC1 in invasive ductal breast carcinoma is related to tumour characteristics and clinical outcome. In addition, negative MUC1 expression is an independent risk factor for poor RFS and OS, besides ‘classical’ prognostic indicators.
Clinical relevance of standardization of endodontic irrigation needle dimensions according to the ISO 9626:1991 and 9626:1991/Amd 1:2001 specification
Authors: Boutsioukis C. , Lambrianidis T. , Vasiliadis L. 
Published: July 2007

AbstractAim  To examine the current status of standardization of endodontic irrigation needles produced by different manufacturers.Methodology  Measurements of needle internal and external diameter were conducted under scanning electron microscopy and stereoscopic microscopy to determine the incidence and degree of deviation from ISO 9626:1991 and ISO 9626:1991/Amd 1:2001 specification.Results  None of the needles examined complied with the ISO nominal size. All SS needles were within the ISO tolerance limits. A Ni‐Ti needle, which is not included in the specification, was found to exceed ISO external diameter limits.Conclusions  Exact knowledge of the tip's external diameter is crucial for the selection of the appropriate size irrigation probe during endodontic treatment. Units of the widely used ‘gauge’ system cannot be directly extrapolated to clinical practice. Adoption of millimetre as the standard metric unit, already recommended by ISO, should be accelerated. A colour‐coding of needles corresponding to endodontic instruments would also be beneficial.
Hyperpolarization‐activated channels in trigeminal ganglia innervating healthy and pulp‐exposed teeth
Authors: Wells J. E. , Rowland K. C. , Proctor E. K. 
Published: July 2007

AbstractAim  To use immunocytochemistry for determining the expression of HCN1, HCN2 and HCN3 (three subunits of the hyperpolarization‐activated cyclic nucleotide‐gated current channel) in rodent trigeminal ganglia (TG) that innervate healthy teeth and determine if expression of HCN subunits is increased in TG following pulp exposure.Methodology  Pulps were exposed in right maxillary incisors of male Sprague‐Dawley rats. After fixation, TG were removed, cryostat sectioned, and immunocytochemistry was utilized to study the expression of HCN1‐3 subunits. Immunoreactivity of individual neurons from the maxillary region of the TG was determined with ImageJ software. Differences in the number immunopositive neurons amongst groups were tested for statistical significance with either a Yates or Pearson’s chi‐square or Fisher’s exact probability tests depending on neuron sample size. Differences in the intensity of immunoreactivity between groups were tested for statistical significance with a Student’s t‐test.Results  The majority of TG neurons were immunopositive for HCN1‐3. Moreover, statistically significant increases in the number of TG neurons immunopositive for HCN1 and the intensity of HCN1‐3 immunoreactivity were observed within hours of exposing the tooth pulp.Conclusions  HCN1‐3 expression, as determined by immunocytochemistry, is increased within hours after injury. Given that Ih can facilitate neuronal excitability, results of the current study suggest that antagonists to HCN1‐3 subunits could work as analgesics in the alleviation of orofacial pain.
Apical sealing ability of Resilon/Epiphany versus gutta‐percha/AH Plus: immediate and 16‐months leakage
Authors: Paqué F. , Sirtes G. 
Published: July 2007

AbstractAim  To compare the long‐term apical sealing ability of gutta‐percha/AH Plus and Resilon/Epiphany.Methodology  The root canals of 90 single‐rooted human mandibular premolars with single narrow root canals were prepared with ProFile 0.4 taper instruments to apical size 40. After each instrument, the canals were irrigated with 1% sodium hypochlorite. Subsequently, the teeth were randomly divided into four groups containing 20 teeth each. Additionally, 10 prepared premolars served as positive and 10 counterparts with intact crowns as negative controls. The root canals were filled with gutta‐percha/AH Plus or Resilon/Epiphany using lateral or vertical compaction. Specimens were allowed to set for 7 days at 37 °C and 100% humidity. Subsequently, the root fillings were removed down to the apical 4 mm. Fluid movement was then assessed using a fluid transportation model and re‐evaluated after 16 months of water storage. Leakage within and between groups was compared using nonparametric tests.Results  Negative controls revealed no fluid movement and positive controls displayed gross fluid movement at both times of observation. At the immediate measurement, there were no significant differences between the experimental groups (Kruskal–Wallis, P > 0.05). Gutta‐percha/AH Plus fillings retained their seal after 16‐months storage (Wilcoxon, P > 0.05), whilst the Resilon/Epiphany groups lost their sealing capacity (Wilcoxon, P < 0.001). In these groups, 29 of the 40 specimens exhibited gross leakage similar to positive controls.Conclusion  Initially, Resilon/Epiphany root fillings prevented fluid movement to the same degree as gutta‐percha/AH Plus counterparts, but showed more fluid movement when tested at 16 months.
The oro‐dental phenotype in Prader–Willi syndrome: a survey of 15 patients
Authors: BAILLEUL‐FORESTIER ISABELLE , VERHAEGHE VERONIEK , FRYNS JEAN‐PIERRE , VINCKIER FRANS , DECLERCK DOMINIQUE , VOGELS ANNICK 
Published: July 2007

Background.  Prader–Willi syndrome (PWS) is a rare disorder caused by genetic defects in certain regions of chromosome 15q11–13. It is characterized by severe neonatal hypotonia and feeding problems, childhood‐onset hyperphagia and obesity, short stature, facial dysmorphy, hypogonadism, learning and behavioural difficulties, and dental abnormalities.Aim.  To describe the oro‐dental phenotypic spectrum of patients with PWS.Design.  Fifteen PWS patients (3–35 years of age) being followed at the Centre for Human Genetics of the University Hospital of Leuven were examined at the dental clinic of the same institution. Medical information collected included age at diagnosis, body mass index (BMI) and level of cognitive functioning. Oral, clinical and radiological evaluations were performed. Caries experience (cavitation level), dental erosion and salivary flow rates were assessed.Results.  The 15 patients had dmft/DMFT scores ranging from 0 to 28, while nine were cavity‐free. Those with severe caries experience also presented advanced dental erosion. BMI ranged from 16 to 42.6. There was no association between BMI and caries experience or erosive tooth wear. The PWS patients in our survey presented with a more favourable oral health status than those in previous studies. This might be due to early diet management or better oral hygiene during childhood or both.
Population dynamics in a long‐lived seabird: I. Impact of breeding activity on survival and breeding probability in unbanded king penguins
Authors: BOHEC CÉLINE LE , GAUTHIER‐CLERC MICHEL , GRÉMILLET DAVID , PRADEL ROGER , BÉCHET ARNAUD , GENDNER JEAN‐PAUL , MAHO YVON LE 
Published: July 2007

SummaryUnderstanding the trade‐off between current reproductive effort, future survival and future breeding attempts is crucial for demographic analyses and life history studies.We investigated this trade‐off in a population of king penguins (Aptenodytes patagonicus) marked individually with transponders using multistate capture–recapture models.This colonial seabird species has a low annual proportion of non‐breeders (13%), despite a breeding cycle which lasts over 1 year. To draw inferences about the consequences of non‐breeding, we tested for an effect of reproductive activity on survival and on the probability of subsequent breeding.We found that birds non‐breeding in yeartshow the same survival rate as breeders (two‐states analysis: breeding and non‐breeding). However, breeders had a lower probability of breeding again the following year. This negative phenotypic correlation suggests the existence of reproductive costs affecting future breeding probability, but it might also be strengthened by late arrival for courtship in yeart.A three‐state analysis including breeding success revealed that failed breeders in yearthave a lower probability to reproduce successfully in yeart + 1 than non‐breeders in yeart, providing some evidence for the existence of reproductive costs. Moreover, successful breeders showed higher survival probability. This positive phenotypic correlation between current reproduction and subsequent survival supports the hypothesis of an heterogeneity in individual quality.Males breeding in yearthad a lower probability to breed again in yeart + 1 than females, suggesting higher reproductive costs for this sex. Such additional costs might be due to higher male parental investment in the final phase of chick‐rearing, which also delays the arrival of males in yeart + 1, and decreases their breeding probability.Our study is the first to explore the breeding biology and the demography of penguins without the disturbance of flipper‐bands.
Short‐term transformation of matrix into hospitable habitat facilitates gene flow and mitigates fragmentation
Authors: BLAUM NIELS , WICHMANN MATTHIAS C. 
Published: July 2007

Summary

Habitat fragmentation has major implications for demography and genetic structure of natural plant and animal populations as small and isolated populations are more prone to extinction. Therefore, many recent studies focus on spatial fragmentation.
However, the temporal configuration of suitable habitat may also influence dispersal and gene flow in fragmented landscapes. We hypothesize that short‐term switching of inhospitable matrix areas into suitable habitat can mitigate effects of spatial fragmentation in natural and seminatural ecosystems.
To test our hypothesis, we investigated the hairy‐footed gerbil (Gerbillurus paeba, Smith 1836), a ground‐dwelling rodent, in fragmented Kalahari savannah areas. Here, rare events of high above mean annual rainfall suggest short‐term matrix suitability.
During the field survey in ‘matrix’ areas in the Kalahari (shrub encroachment by heavy grazing) we never observed the hairy‐footed gerbil in years of average rainfall, but observed mass occurrences of this species during rare events of exceptionally high rainfall.
In a second step, we developed an agent‐based model simulating subpopulations in two neighbouring habitats and the separating matrix. Our mechanistic model reproduces the mass occurrences as observed in the field and thus suggests the possibly underlying processes. In particular, the temporary improvement in matrix quality allows reproduction in the matrix, thereby causing a substantial increase in population size.
The model demonstrates further how the environmental trigger (rainfall) impacts genetic connectivity of two separated subpopulations. We identified seasonality as a driver of fragmentation but stochasticity leading to higher connectivity.
We found that our concept of temporal fragmentation can be applied to numerous other fragmented populations in various ecological systems and provide examples from recent literature. We conclude that temporal aspects of fragmentation must be considered in both ecological research and conservation management.
Quantifying and comparing bumblebee nest densities in gardens and countryside habitats
Authors: Osborne Juliet L. , Martin Andrew P. , Shortall Chris R. , Todd Alan D. , Goulson Dave , Knight Mairi E. , Hale Roddy J. , Sanderson Roy A. 
Published: July 2007

Summary

Bumblebees provide an important pollination service to both crops and wild plants. Many species have declined in the UK, particularly in arable regions. While bumblebee forage requirements have been widely studied, there has been less consideration of whether availability of nesting sites is limiting. It is important to know which habitats contain the most bumblebee nests per unit area in order to guide conservation and management options; particularly in the light of current emphasis on environmental stewardship schemes for farmed landscapes. However, it is extremely difficult to map the distribution of bumblebee nests.
We describe the findings of the National Bumblebee Nest Survey, a structured survey carried out by 719 volunteers in the UK during early summer 2004. The surveyors used a defined protocol to record the presence or absence of bumblebee nests in prescribed areas of gardens, short grassland, long grassland and woodland, and along woodland edge, hedgerows and fence lines. The records allowed us to estimate the density of bumblebee nests in each of these habitats for the first time.
Nest densities were high in gardens (36 nests ha−1), and linear countryside habitats (fence lines, hedgerows, woodland edge: 20–37 nests ha−1), and lower in non‐linear countryside habitats (woodland and grassland: 11–15 nests ha−1).
Findings on nest location characteristics corroborate those of an earlier survey carried out in the UK (Fussell & Corbet 1992).
Synthesis and applications. Gardens provide an important nesting habitat for bumblebees in the UK. In the countryside, the area occupied by linear features is small compared with that of non‐linear features. However, as linear features contain high densities of nests, management options affecting such features may have a disproportionately large effect on bumblebee nesting opportunities. Current farm stewardship schemes in the UK are therefore likely to facilitate bumblebee nesting, because they provide clear guidance and support for ‘sympathetic’ hedgerow and field margin management.