1,770 research outputs found
Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales
Aim: To define good and poor regression using pathology and MRI regression scales after neo-adjuvant chemotherapy for rectal cancer. Methods: A systematic review of all studies up to December 2015, without language restriction that were identified from MEDLINE, Cochrane Controlled Trials Register (1960–2015), and EMBASE (1991–2015). Searches were performed of article bibliographies and conference abstracts. MeSH and text words, included “tumour regression”, “mrTRG”, “poor response” and “colorectal cancers”. Clinical studies using either MRI or histopathological TRG scales to define good and poor responders were included in relation to outcomes (local (LR), distant recurrence (DR), disease free (DFS), overall survival (OS)). There was no age restriction to included patients nor stage of cancer.Data was extracted by two authors independently using pre-defined outcome measures. Results: Quantitative data (prevalence) were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. Qualitative data (LR, DR, DFS &OS) were presented as ranges. The overall proportion of poor responders after neo-adjuvant CRT was 37.7% (CI: 30.1 to 45.8). There were 19 different reported histopathological scales and one MRI regression scale (mrTRG). Clinical studies used nine and six histopathological scales for poor and good responders respectively. All studies using MRI to define good and poor response used one scale. The most common histopathological definition for good response was the Mandard grades 1&2 or Dworak grades 3&4; Mandard 3,4&5 and Dworak 0,1&2 were used for poor response. For histopathological grades, the 5-year outcomes for poor responders were LR 3.4-4.3%, DR 14.3-20.3%, DFS 61.7-68.1% and OS 60.7-69.1. Good pathological response 5-year outcomes were LR, 0-1.8%; DR, 0-11.6%; DFS, 78.4-86.7%; and, OS, 77.4-88.2%. A poor response on MRI (mrTRG 4,5) resulted in 5-year LR 4-29%, DR 9%, DFS 31-59% and OS 27-68%. The 5-year outcomes with a good response on MRI (mrTRG 1,2 & 3) was LR 1-14%, DR 3%, DFS 64-83% and OS 72-90%. Conclusions: For histopathology regression assessment Mandard1,2/Dworak3,4 should be used for good and Mandard3,4,5/Dworak0,1,2 for poor response. MRI indicates good and poor response by mrTRG1-3 and mrTRG4-5 respectively
Proteomic analysis of filaggrin deficiency identifies molecular signatures characteristic of atopic eczema
\ua9 2017 The Authors. Background: Atopic eczema (AE) is characterized by skin barrier and immune dysfunction. Null mutations in filaggrin (FLG), a key epidermal barrier protein, strongly predispose to AE; however, the precise role of FLG deficiency in AE pathogenesis remains incompletely understood. Objectives: We sought to identify global proteomic changes downstream of FLG deficiency in human epidermal living skin-equivalent (LSE) models and validate findings in skin of patients with AE. Methods: Differentially expressed proteins from paired control (nontargeting control short hairpin RNA [shNT]) and FLG knockdown (FLG knockdown short hairpin RNA [shFLG]) LSEs were identified by means of proteomic analysis (liquid chromatography-mass spectrometry) and Ingenuity Pathway Analysis. Expression of key targets was validated in independent LSE samples (quantitative RT-PCR and Western blotting) and in normal and AE skin biopsy specimens (immunofluorescence). Results: Proteomic analysis identified 17 (P ≤ .05) differentially expressed proteins after FLG knockdown, including kallikrein-7 (KLK7; 2.2-fold), cyclophilin A (PPIA; 0.9-fold), and cofilin-1 (CFL1, 1.3-fold). Differential protein expression was confirmed in shNT/shFLG LSEs; however, only KLK7 was transcriptionally dysregulated. Molecular pathways overrepresented after FLG knockdown included inflammation, protease activity, cell structure, and stress. Furthermore, KLK7 (1.8-fold) and PPIA (0.65-fold) proteins were differentially expressed in lesional biopsy specimens from patients with AE relative to normal skin. Conclusions: For the first time, we show that loss of FLG in the absence of inflammation is sufficient to alter the expression level of proteins relevant to the pathogenesis of AE. These include proteins regulating inflammatory, proteolytic, and cytoskeletal functions. We identify PPIA as a novel protein with levels that are decreased in clinically active AE skin and show that the characteristic upregulation of KLK7 expression in patients with AE occurs downstream of FLG loss. Importantly, we highlight disconnect between the epidermal proteome and transcriptome, emphasizing the utility of global proteomic studies
A global perspective on marine photosynthetic picoeukaryote community structure
A central goal in ecology is to understand the factors affecting the temporal dynamics and spatial distribution of microorganisms and the underlying processes causing differences in community structure and composition. However, little is known in this respect for photosynthetic picoeukaryotes (PPEs), algae that are now recognised as major players in marine CO2 fixation. Here, we analysed dot blot hybridisation and cloning–sequencing data, using the plastid-encoded 16S rRNA gene, from seven research cruises that encompassed all four ocean biomes. We provide insights into global abundance, α- and β-diversity distribution and the environmental factors shaping PPE community structure and composition. At the class level, the most commonly encountered PPEs were Prymnesiophyceae and Chrysophyceae. These taxa displayed complementary distribution patterns, with peak abundances of Prymnesiophyceae and Chrysophyceae in waters of high (25:1) or low (12:1) nitrogen:phosphorus (N:P) ratio, respectively. Significant differences in phylogenetic composition of PPEs were demonstrated for higher taxonomic levels between ocean basins, using Unifrac analyses of clone library sequence data. Differences in composition were generally greater between basins (interbasins) than within a basin (intrabasin). These differences were primarily linked to taxonomic variation in the composition of Prymnesiophyceae and Prasinophyceae whereas Chrysophyceae were phylogenetically similar in all libraries. These data provide better knowledge of PPE community structure across the world ocean and are crucial in assessing their evolution and contribution to CO2 fixation, especially in the context of global climate change
Abnormal corneal epithelial maintenance in mice heterozygous for the micropinna microphthalmia mutation Mp
We investigated the corneal morphology of adult Mp/Ăľ mice, which are heterozygous for the micropinna
microphthalmia mutation, and identified several abnormalities, which implied that corneal epithelial
maintenance was abnormal. The Mp/Ăľ corneal epithelium was thin, loosely packed and contained goblet
cells in older mice. Evidence also suggested that the barrier function was compromised. However, there
was no major effect on corneal epithelial cell turnover and mosaic patterns of radial stripes indicated that
radial cell movement was normal. Limbal blood vessels formed an abnormally wide limbal vasculature
ring, K19-positive cells were distributed more widely than normal and K12 was weakly expressed in the
peripheral cornea. This raises the possibilities that the limbal-corneal boundary was poorly defined or
the limbus was wider than normal. BrdU label-retaining cell numbers and quantitative clonal analysis
suggested that limbal epithelial stem cell numbers were not depleted and might be higher than normal.
However, as corneal epithelial homeostasis was abnormal, it is possible that Mp/Ăľ stem cell function was
impaired. It has been shown recently that the Mp mutation involves a chromosome 18 inversion that
disrupts the Fbn2 and Isoc1 genes and produces an abnormal, truncated fibrillin-2MP protein. This
abnormal protein accumulates in the endoplasmic reticulum (ER) of cells that normally express Fbn2 and
causes ER stress. It was also shown that Fbn2 is expressed in the corneal stroma but not the corneal
epithelium, suggesting that the presence of truncated fibrillin-2MP protein in the corneal stroma disrupts
corneal epithelial homeostasis in Mp/Ăľ mice
Solar-type dynamo behaviour in fully convective stars without a tachocline
In solar-type stars (with radiative cores and convective envelopes), the
magnetic field powers star spots, flares and other solar phenomena, as well as
chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The
dynamo responsible for generating the field depends on the shearing of internal
magnetic fields by differential rotation. The shearing has long been thought to
take place in a boundary layer known as the tachocline between the radiative
core and the convective envelope. Fully convective stars do not have a
tachocline and their dynamo mechanism is expected to be very different,
although its exact form and physical dependencies are not known. Here we report
observations of four fully convective stars whose X-ray emission correlates
with their rotation periods in the same way as in Sun-like stars. As the X-ray
activity - rotation relationship is a well-established proxy for the behaviour
of the magnetic dynamo, these results imply that fully convective stars also
operate a solar-type dynamo. The lack of a tachocline in fully convective stars
therefore suggests that this is not a critical ingredient in the solar dynamo
and supports models in which the dynamo originates throughout the convection
zone.Comment: 6 pages, 1 figure. Accepted for publication in Nature (28 July 2016).
Author's version, including Method
The incidence of other gastroenterological disease following diagnosis of irritable bowel syndrome in the UK: a cohort study
BACKGROUND: Guidelines recommend Irritable Bowel Syndrome (IBS) diagnosis and management in primary care with minimal investigations; however little evidence exists regarding risk of organic gastrointestinal conditions following diagnosis of IBS and how such risks vary over the long term. This study assesses excess incidence of coeliac disease, inflammatory bowel disease (IBD) and colorectal cancer (CRC) and variation with age and time after IBS diagnosis.
METHODS: IBS patients and controls were identified within the UK Clinical Practice Research Dataset. Incidence rates were calculated and stratified by age and time since IBS diagnosis with incident rate ratios generated.
RESULTS: Fifteen years after IBS diagnosis there is a significant cumulative excess incidence of coeliac disease, IBD and CRC in IBS of 3.7% compared to 1.7% in controls. For every 10000 patient years, IBS patients experienced an additional 4 diagnoses of coeliac disease, 13 of IBD and 4 CRCs. In each condition peak excess incidence was in the 6 months following diagnosis. After one year, increased incidence of coeliac disease remained consistent without variation by age. IBD incidence fell slowly, with higher rates in those under 30. CRC incidence was increased only in patients aged 30 to 74 during the first 5 years.
CONCLUSION: Some IBS patients later receive organic gastrointestinal diagnoses, with the early excess incidence likely detected during diagnostic investigation at the time of IBS diagnosis. More than 5 years after IBS diagnosis there is no increased risk of CRC compared to the general population, but a small excess risk of coeliac disease and IBD persists. Overall, though our findings provide reassurance that non-specialists, especially those in primary care, are unlikely to be missing an organic condition in the majority of their patients. This suggests that current guidelines suggesting avoidance of universal referral for these patients are appropriate
A lithium-isotope perspective on the evolution of carbon and silicon cycles
The evolution of the global carbon and silicon cycles is thought to have contributed to the long-term stability of Earth's climate. Many questions remain, however, regarding the feedback mechanisms at play, and there are limited quantitative constraints on the sources and sinks of these elements in Earth's surface environments. Here we argue that the lithium-isotope record can be used to track the processes controlling the long-term carbon and silicon cycles. By analysing more than 600 shallow-water marine carbonate samples from more than 100 stratigraphic units, we construct a new carbonate-based lithium-isotope record spanning the past 3 billion years. The data suggest an increase in the carbonate lithium-isotope values over time, which we propose was driven by long-term changes in the lithium-isotopic conditions of sea water, rather than by changes in the sedimentary alterations of older samples. Using a mass-balance modelling approach, we propose that the observed trend in lithium-isotope values reflects a transition from Precambrian carbon and silicon cycles to those characteristic of the modern. We speculate that this transition was linked to a gradual shift to a biologically controlled marine silicon cycle and the evolutionary radiation of land plants
Interactions and potential implications of Plasmodium falciparum-hookworm coinfection in different age groups in south-central CĂ´te d'Ivoire
BACKGROUND: Given the widespread distribution of Plasmodium and helminth infections, and similarities of ecological requirements for disease transmission, coinfection is a common phenomenon in sub-Saharan Africa and elsewhere in the tropics. Interactions of Plasmodium falciparum and soil-transmitted helminths, including immunological responses and clinical outcomes of the host, need further scientific inquiry. Understanding the complex interactions between these parasitic infections is of public health relevance considering that control measures targeting malaria and helminthiases are going to scale.METHODOLOGY: A cross-sectional survey was carried out in April 2010 in infants, young school-aged children, and young non-pregnant women in south-central CĂ´te d'Ivoire. Stool, urine, and blood samples were collected and subjected to standardized, quality-controlled methods. Soil-transmitted helminth infections were identified and quantified in stool. Finger-prick blood samples were used to determine Plasmodium spp. infection, parasitemia, and hemoglobin concentrations. Iron, vitamin A, riboflavin, and inflammation status were measured in venous blood samples.PRINCIPAL FINDINGS: Multivariate regression analysis revealed specific association between infection and demographic, socioeconomic, host inflammatory and nutritional factors. Non-pregnant women infected with P. falciparum had significantly lower odds of hookworm infection, whilst a significant positive association was found between both parasitic infections in 6- to 8-year-old children. Coinfected children had lower odds of anemia and iron deficiency than their counterparts infected with P. falciparum alone.CONCLUSIONS/SIGNIFICANCE: Our findings suggest that interaction between P. falciparum and light-intensity hookworm infections vary with age and, in school-aged children, may benefit the host through preventing iron deficiency anemia. This observation warrants additional investigation to elucidate the mechanisms and consequences of coinfections, as this information could have important implications when implementing integrated control measures against malaria and helminthiases
Updated Three-Stage Model for the Peopling of the Americas
Background: We re-assess support for our three stage model for the peopling of the Americas in light of a recent report that identified nine non-Native American mitochondrial genome sequences that should not have been included in our initial analysis. Removal of these sequences results in the elimination of an early (i.e.,40,000 years ago) expansion signal we had proposed for the proto-Amerind population. Methodology/Findings: Bayesian skyline plot analysis of a new dataset of Native American mitochondrial coding genomes confirms the absence of an early expansion signal for the proto-Amerind population and allows us to reduce the variation around our estimate of the New World founder population size. In addition, genetic variants that define New World founder haplogroups are used to estimate the amount of time required between divergence of proto-Amerinds from the Asian gene pool and expansion into the New World. Conclusions/Significance: The period of population isolation required for the generation of New World mitochondrial founder haplogroup-defining genetic variants makes the existence of three stages of colonization a logical conclusion. Thus, our three stage model remains an important and useful working hypothesis for researchers interested in the peopling of th
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