2,003 research outputs found
Calcisponges have a ParaHox gene and dynamic expression of dispersed NK homeobox genes
This study was funded by the Sars Centre core budget to M. Adamska. Sequencing was performed at the Norwegian High Throughput Sequencing Centre funded by the Norwegian Research Council. O.M.R. and D.E.K.F. acknowledge support from the BBSRC and the School of Biology, University of St Andrews.Sponges are simple animals with few cell types, but their genomes paradoxically contain a wide variety of developmental transcription factors1,2,3,4, including homeobox genes belonging to the Antennapedia (ANTP) class5,6, which in bilaterians encompass Hox, ParaHox and NK genes. In the genome of the demosponge Amphimedon queenslandica, no Hox or ParaHox genes are present, but NK genes are linked in a tight cluster similar to the NK clusters of bilaterians5. It has been proposed that Hox and ParaHox genes originated from NK cluster genes after divergence of sponges from the lineage leading to cnidarians and bilaterians5,7. On the other hand, synteny analysis lends support to the notion that the absence of Hox and ParaHox genes in Amphimedon is a result of secondary loss (the ghost locus hypothesis)8. Here we analysed complete suites of ANTP-class homeoboxes in two calcareous sponges, Sycon ciliatum and Leucosolenia complicata. Our phylogenetic analyses demonstrate that these calcisponges possess orthologues of bilaterian NK genes (Hex, Hmx and Msx), a varying number of additional NK genes and one ParaHox gene, Cdx. Despite the generation of scaffolds spanning multiple genes, we find no evidence of clustering of Sycon NK genes. All Sycon ANTP-class genes are developmentally expressed, with patterns suggesting their involvement in cell type specification in embryos and adults, metamorphosis and body plan patterning. These results demonstrate that ParaHox genes predate the origin of sponges, thus confirming the ghost locus hypothesis8, and highlight the need to analyse the genomes of multiple sponge lineages to obtain a complete picture of the ancestral composition of the first animal genome.PostprintPeer reviewe
Epitope mapping of cytochrome P450 cholesterol side-chain cleavage enzyme by sera from patients with autoimmune polyglandular syndrome type 1
OBJECTIVE: Autoimmune polyglandular syndrome type 1 (APS-1) is a disease associated with defects of the autoimmune regulator gene and is characterized by autoimmune lesions of several tissues, predominantly endocrine glands, with multiple autoantibodies. In this study we describe autoantigenic epitopes on cholesterol side-chain cleavage enzyme (P450scc) using sera from Finnish and Sardinian patients with APS-1, and analyze the epitope reactivities during disease follow-up. METHODS: A series of P450scc cDNA fragments were expressed in E. coli and tested by immunoblotting assay using the patients' sera. RESULTS: Epitope regions were found over the whole P450scc molecule except the last N- (amino acids (aa) 1-40) and C-termini (aa 456-521). The strongest reactivity with patients' sera was found with central and C-terminal regions of the P450scc protein. All studied patients had IgG1 subclass antibodies. CONCLUSIONS: The results show that Finnish and Sardinian patients with APS-1 have similar, polyclonal immune reactions against P450scc, and that epitope reactivities did not change during the disease course. These results support the opinion that autoantibodies against P450scc and their epitope reactivity pattern are formed at an early stage of steroidogenic autoimmunity
Inter-examiner reliability of the diagnosis of cervical pillar hyperplasia (CPH) and the correlation between CPH and spinal degenerative joint disease (DJD)
BACKGROUND: Cervical pillar hyperplasia (CPH) is a recently described phenomenon of unknown aetiology. Its clinical importance is poorly understood at the present time; therefore, the objective of this study was to determine (1) the inter-examiner reliability of detecting CPH and (2) if there is a clinically important correlation (r > 0.4) between the number of cervical spine levels showing signs of degenerative joint disease (DJD) and CPH. METHODS: The sample consisted of 320 radiographs of human male and female subjects who ranged from 40 to 79 years of age. The inter-examiner reliability of assessing the presence/absence of pillar hyperplasia was evaluated on 50 neutral lateral radiographs by two examiners using line drawings and it was quantified using the kappa coefficient of concordance. To determine the presence/absence of hyperplastic pillars as well as the presence/absence of DJD at each intervertebral disc and zygapophysial joint, 320 AP open mouth, AP lower cervical and neutral lateral radiographs were then examined. The unpaired t-test at the 5% level of significance was performed to test for a statistically significant difference between the number of levels affected by DJD in patients with and without hyperplasia. The Spearman's rho at the 5% level of significance was performed to quantify the correlation between DJD and age. RESULTS: The inter-examiner reliability of detecting cervical pillar hyperplasia was moderate with a kappa coefficient of 0.51. The unpaired t-test indicated that there was no statistically significant difference (p > 0.05) between the presence/absence of cervical pillar hyperplasia and the number of levels affected by DJD in an age-matched population, regardless of whether all elements were considered together, or the discs and facets were analyzed separately. A Spearman correlation rank of 0.67 (p < 0.05) suggested a moderately strong correlation between the number of elements (i.e. discs/facets) affected, and the age of the individual. CONCLUSION: Cervical pillar hyperplasia is a reasonable concept that requires further research. Its evaluation is easy to learn and acceptably reliable. Previous research has suggested that CPH may affect the cervical lordosis, and therefore, alter biomechanics which may result in premature DJD. This current study, however, indicates that, globally, CPH does not appear to be related to the development of DJD
Progressive slip after removal of screw fixation in slipped capital femoral epiphysis: two case reports
<p>Abstract</p> <p>Introduction</p> <p>In slipped capital femoral epiphysis the femoral neck displaces relative to the head due to weakening of the epiphysis. Early recognition and adequate surgical fixation is essential for a good functional outcome. The fixation should be secured until the closure of the epiphysis to prevent further slippage. A slipped capital femoral epiphysis should not be confused with a femoral neck fracture.</p> <p>Case presentation</p> <p>Case 1 concerns a 15-year-old boy with an adequate initial screw fixation of his slipped capital femoral epiphysis. Unfortunately, it was thought that the epiphysis had healed and the screw was removed after 11 weeks. This caused new instability with a progressive slip of the femoral epiphysis and subsequently re-fixation and a subtrochanteric correction osteotomy was obligatory. Case 2 concerns a 13-year-old girl with persistent hip pain after screw fixation for slipped capital femoral epiphysis. The screw was removed as lysis was seen around the screw on the hip X-ray. This operation created a new unstable situation and the slip progressed resulting in poor hip function. A correction osteotomy with re-screw fixation was performed with a good functional result.</p> <p>Conclusion</p> <p>A slipped epiphysis of the hip is not considered âhealedâ after a few months. Given the risk of progression of the slip the fixation material cannot be removed before closure of the growth plate.</p
Heavy Flavour Production at Tevatron and Parton Shower Effects
We present hadron-level predictions from the Monte Carlo generator Cascade
and numerical calculations of charm and beauty production at the Fermilab
Tevatron within the framework of the -factorization QCD approach. Our
consideration is based on the CCFM-evolved unintegrated gluon densities in a
proton. The performed analysis covers the total and differential cross sections
of open charm and beauty quarks, and mesons (or rather muons from their
semileptonic decays) and the total and differential cross sections of di-jet hadroproduction. We study the theoretical uncertainties of our
calculations and investigate the effects coming from parton showers in initial
and final states. Our predictions are compared with the recent experimental
data taken by the D0 and CDF collaborations. Special attention is put on the
specific angular correlations between the final-state particles. We demonstrate
that the final state parton shower plays a crucial role in the description of
such observables. The decorrelated part of angular separations can be fully
described, if the process is included.Comment: Fig 8,9 10 replaced, small corrections in text A discussion of the
delta phi results is adde
Beetle (Coleoptera: Scirtidae) Facilitation of Larval Mosquito Growth in Tree Hole Habitats is Linked to Multitrophic Microbial Interactions
Container-breeding mosquitoes, such as Aedes triseriatus, ingest biofilms and filter water column microorganisms directly to obtain the bulk of their nutrition. Scirtid beetles often co-occur with A. triseriatus and may facilitate the production of mosquito adults under low-resource conditions. Using molecular genetic techniques and quantitative assays, we observed changes in the dynamics and composition of bacterial and fungal communities present on leaf detritus and in the water column when scirtid beetles co-occur with A. triseriatus. Data from terminal restriction fragment polymorphism analysis indicated scirtid presence alters the structure of fungal communities in the water column but not leaf-associated fungal communities. Similar changes in leaf and water bacterial communities occurred in response to mosquito presence. In addition, we observed increased processing of leaf detritus, higher leaf-associated enzyme activity, higher bacterial productivity, and higher leaf-associated fungal biomass when scirtid beetles were present. Such shifts suggest beetle feeding facilitates mosquito production indirectly through the microbial community rather than directly through an increase in available fine particulate organic matter
Effective theories of single field inflation when heavy fields matter
We compute the low energy effective field theory (EFT) expansion for
single-field inflationary models that descend from a parent theory containing
multiple other scalar fields. By assuming that all other degrees of freedom in
the parent theory are sufficiently massive relative to the inflaton, it is
possible to derive an EFT valid to arbitrary order in perturbations, provided
certain generalized adiabaticity conditions are respected. These conditions
permit a consistent low energy EFT description even when the inflaton deviates
off its adiabatic minimum along its slowly rolling trajectory. By generalizing
the formalism that identifies the adiabatic mode with the Goldstone boson of
this spontaneously broken time translational symmetry prior to the integration
of the heavy fields, we show that this invariance of the parent theory dictates
the entire non-perturbative structure of the descendent EFT. The couplings of
this theory can be written entirely in terms of the reduced speed of sound of
adiabatic perturbations. The resulting operator expansion is distinguishable
from that of other scenarios, such as standard single inflation or DBI
inflation. In particular, we re-derive how certain operators can become
transiently strongly coupled along the inflaton trajectory, consistent with
slow-roll and the validity of the EFT expansion, imprinting features in the
primordial power spectrum, and we deduce the relevant cubic operators that
imply distinct signatures in the primordial bispectrum which may soon be
constrained by observations.Comment: (v1) 25 pages, 1 figure; (v2) references added and typos corrected,
to appear in Journal of High Energy Physic
Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice
Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (nâ=â43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank pâ=â0.03) for HIV-1(JRCSF) and 0% (0/6; log rank pâ=â0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides
Response of Coastal Fishes to the Gulf of Mexico Oil Disaster
The ecosystem-level impacts of the Deepwater Horizon disaster have been largely unpredictable due to the unique setting and magnitude of this spill. We used a five-year (2006â2010) data set within the oil-affected region to explore acute consequences for early-stage survival of fish species inhabiting seagrass nursery habitat. Although many of these species spawned during spring-summer, and produced larvae vulnerable to oil-polluted water, overall and species-by-species catch rates were high in 2010 after the spill (1,989±220 fishes km-towedâ1 [ÎŒ ± 1SE]) relative to the previous four years (1,080±43 fishes km-towedâ1). Also, several exploited species were characterized by notably higher juvenile catch rates during 2010 following large-scale fisheries closures in the northern Gulf, although overall statistical results for the effects of fishery closures on assemblage-wide CPUE data were ambiguous. We conclude that immediate, catastrophic losses of 2010 cohorts were largely avoided, and that no shifts in species composition occurred following the spill. The potential long-term impacts facing fishes as a result of chronic exposure and delayed, indirect effects now require attention
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