Variation in xylem vessel diameter is one of the most important parameters when evaluating plant water relations. This review provides a synthesis of the ecophysiological implications of variation in ...lumen diameter together with a summary of our current understanding of vessel development and its endogenous regulation. We analyzed inter‐specific variation of the mean hydraulic vessel diameter (Dv) across biomes, intra‐specific variation of Dv under natural and controlled conditions, and intra‐plant variation. We found that the Dv measured in young branches tends to stay below 30 µm in regions experiencing winter frost, whereas it is highly variable in the tropical rainforest. Within a plant, the widest vessels are often found in the trunk and in large roots; smaller diameters have been reported for leaves and small lateral roots. Dv varies in response to environmental factors and is not only a function of plant size. Despite the wealth of data on vessel diameter variation, the regulation of diameter is poorly understood. Polar auxin transport through the vascular cambium is a key regulator linking foliar and xylem development. Limited evidence suggests that auxin transport is also a determinant of vessel diameter. The role of auxin in cell expansion and in establishing longitudinal continuity during secondary growth deserve further study.
Variation in xylem vessel diameter impacts transport efficiency, vulnerability to freezing‐induced embolism, and other aspects of plant biology. This review provides a synthesis of the ecophysiological implications of variation in lumen diameter together with a summary of our current understanding of vessel development and its endogenous regulation. Emphasis is placed on the presumed role of auxin at multiple developmental stages.
We developed a validated index for assessing histological disease activity in UC and established its responsiveness.
Two hundred biopsies were scored. The outcome was the Global Visual Evaluation ...(GVE). Eight histological features were tested. The Nancy index was developed by multiple linear regression and bootstrap process to create an index that best matched the GVE. Goodness of fit was assessed by the adjusted R squared (adjusted R
). The second step was the validation of the index: 100 biopsies were scored for the Nancy index by three pathologists from different centres. Inter-reader reliability was evaluated for each reader. The relationship between the change of the Nancy index and the Geboes index was assessed to assess the responsiveness.
After backward selection with bootstrap validation, 3/8 items were selected: ulceration (adjusted R
=0.55), acute inflammatory infiltrate (adjusted R
=0.88) and chronic inflammatory infiltrate (adjusted R
=0.79). The Nancy index is defined by a 5-level classification ranging from grade 0 (absence of significant histological disease activity) to grade 4 (severely active disease). The intraclass correlation coefficient (ICC) for the intrareader reliability was 0.88 (95% CI 0.82 to 0.92) and the index had good inter-reader reliability (ICC=0.86 (0.81 to 0.99)). The correlation between the Nancy index and the Geboes score or the GVE was very good. The index had a good responsiveness with a high correlation between changes in the Geboes score and changes in the Nancy index (0.910 (0.813 to 0.955)).
A three descriptor histological index has been validated for use in clinical practice and clinical trials.
In this article we provide a contemporary overview of available clinical data on certolizumab pegol, a pegylated anti-tumor necrosis factor (TNF) alpha agent that comprises a uniquely small protein, ...and its emerging role as a therapy for Crohn’s disease (CD). The results from a comprehensive clinical trial program suggest that certolizumab pegol offers rapid and sustained remission of moderate to severe CD. Certolizumab pegol is an effective and well-tolerated therapy both in patients who have already received biologics and in patients who are anti-TNF naïve. Benefits of therapy include a stable dosing regimen, which allows for rapid induction of a clinical response followed by long-term maintenance of response and remission under one fixed dose. Treatment with certolizumab pegol has been shown to improve function and quality of life in patients with CD, and insights into the potential mechanisms by which certolizumab pegol effects a response in CD suggest that this agent may have the potential to slow or even modify disease progression. Early therapy is particularly effective and could help control CD progression and lessen the burden of disease on patients.
ADHD is a psychiatric disorder which is characterized by hyperactivity, impulsivity and attention problems. Due to recent findings of microbial involvement in other psychiatric disorders like autism ...and depression, a role of the gut microbiota in ADHD pathogenesis is assumed but has not yet been investigated. In this study, the gut microbiota of 14 male ADHD patients (mean age: 11.9 yrs.) and 17 male controls (mean age: 13.1 yrs.) was examined via next generation sequencing of 16S rDNA and analyzed for diversity and biomarkers. We found that the microbial diversity (alpha diversity) was significantly decreased in ADHD patients compared to controls (pShannon = 0.036) and that the composition (beta diversity) differed significantly between patients and controls (pANOSIM = 0.033, pADONIS = 0.006, pbetadisper = 0.002). In detail, the bacterial family Prevotellacae was associated with controls, while patients with ADHD showed elevated levels of Bacteroidaceae, and both Neisseriaceae and Neisseria spec. were found as possible biomarkers for juvenile ADHD. Our results point to a possible link of certain microbiota with ADHD, with Neisseria spec. being a very promising ADHD-associated candidate. This finding provides the basis for a systematic, longitudinal assessment of the role of the gut microbiome in ADHD, yielding promising potential for both prevention and therapeutic intervention.
Summary
Xylem vessel diameters represent an important plant hydraulic trait to ensure sufficient water supply from the roots to the leaves. The ability to adjust the hydraulic pathway to ...environmental cues is key in order to satisfy transpirational demands and maximize growth and survival.
We evaluated the variability of vessel diameters in trembling aspen in a reciprocal transplant experiment. We tested six provenances from three ecological regions of North America planted at four test sites in western Canada. All test sites were established at the same time with the same provenances arranged in a randomized complete block design.
Vessel diameter showed a strong interaction of population and test site suggesting a high degree of phenotypic plasticity in this trait. Gaussian kernel density estimates support plastic as well as genetic contributions in vessel diameter control trending from bimodal distributions at the most northern test site towards unimodal distributions at the warmest and mildest test site.
Furthermore, we used test site‐specific climate data in form of a 2‐year, 5‐year and 10‐year average of 21 directly and derived climatic variables and found that average site‐specific vessel diameters correlated strongly with summer moisture availability. A previously found negative relationship with vessel diameter and tree height in central Alberta was also found at two other boreal test sites but reversed at a wetter and milder sub‐boreal test site.
In summary, vessel diameters were highly plastic in response to different environments and varied with summer moisture availability. The variability of vessel diameter and tree height correlations suggests that vessel diameter alone cannot serve as a reliable proxy for long‐term growth performance beyond boreal environments. Instead, selecting aspen populations with a high degree of plasticity in this trait appears to be the safest option for assisted migration and seed transfer programmes under climate change.
Lay Summary
Tofacitinib, an oral, small-molecule Janus kinase inhibitor, was shown to have potential efficacy as induction therapy for ulcerative colitis in a phase 2 trial. We further evaluated the efficacy of ...tofacitinib as induction and maintenance therapy.
We conducted three phase 3, randomized, double-blind, placebo-controlled trials of tofacitinib therapy in adults with ulcerative colitis. In the OCTAVE Induction 1 and 2 trials, 598 and 541 patients, respectively, who had moderately to severely active ulcerative colitis despite previous conventional therapy or therapy with a tumor necrosis factor antagonist were randomly assigned to receive induction therapy with tofacitinib (10 mg twice daily) or placebo for 8 weeks. The primary end point was remission at 8 weeks. In the OCTAVE Sustain trial, 593 patients who had a clinical response to induction therapy were randomly assigned to receive maintenance therapy with tofacitinib (either 5 mg or 10 mg twice daily) or placebo for 52 weeks. The primary end point was remission at 52 weeks.
In the OCTAVE Induction 1 trial, remission at 8 weeks occurred in 18.5% of the patients in the tofacitinib group versus 8.2% in the placebo group (P=0.007); in the OCTAVE Induction 2 trial, remission occurred in 16.6% versus 3.6% (P<0.001). In the OCTAVE Sustain trial, remission at 52 weeks occurred in 34.3% of the patients in the 5-mg tofacitinib group and 40.6% in the 10-mg tofacitinib group versus 11.1% in the placebo group (P<0.001 for both comparisons with placebo). In the OCTAVE Induction 1 and 2 trials, the rates of overall infection and serious infection were higher with tofacitinib than with placebo. In the OCTAVE Sustain trial, the rate of serious infection was similar across the three treatment groups, and the rates of overall infection and herpes zoster infection were higher with tofacitinib than with placebo. Across all three trials, adjudicated nonmelanoma skin cancer occurred in five patients who received tofacitinib and in one who received placebo, and adjudicated cardiovascular events occurred in five who received tofacitinib and in none who received placebo; as compared with placebo, tofacitinib was associated with increased lipid levels.
In patients with moderately to severely active ulcerative colitis, tofacitinib was more effective as induction and maintenance therapy than placebo. (Funded by Pfizer; OCTAVE Induction 1, OCTAVE Induction 2, and OCTAVE Sustain ClinicalTrials.gov numbers, NCT01465763 , NCT01458951 , and NCT01458574 , respectively.).
Summary Background Filgotinib (GLPG0634, GS-6034) is a once-daily, orally administered, Janus kinase 1 (JAK1)-selective inhibitor. The FITZROY study examined the efficacy and safety of filgotinib for ...the treatment of moderate-to-severe Crohn's disease. Methods We did a randomised, double-blind, placebo-controlled phase 2 study, which recruited patients from 52 centres in nine European countries. We enrolled eligible patients aged 18–75 years with a documented history of ileal, colonic, or ileocolonic Crohn's disease for 3 months or more before screening, as assessed by colonoscopy and supported by histology, and a Crohn's Disease Activity Index (CDAI) score during screening between 220 and 450 inclusive. Patients were randomly assigned (3:1) to receive filgotinib 200 mg once a day or placebo for 10 weeks. Patients were stratified according to previous anti-tumour necrosis factor alpha exposure, C-reactive protein concentration at screening (≤10 mg/L or >10 mg/L), and oral corticosteroid use at baseline, using an interactive web-based response system. The primary endpoint was clinical remission, defined as CDAI less than 150 at week 10. After week 10, patients were assigned based on responder status to filgotinib 100 mg once a day, filgotinib 200 mg once a day, or placebo for an observational period lasting a further 10 weeks. The filgotinib and placebo treatment groups were compared using ANCOVA models and logistic regression models containing baseline values and randomisation stratification factors as fixed effects. Analyses were done on the intention-to-treat non-responder imputation set. The trial was registered at ClinicalTrials.gov , number NCT02048618. Findings Between Feb 3, 2014, and July 10, 2015, we enrolled 174 patients with active Crohn's disease confirmed by centrally read endoscopy (130 in the filgotinib 200 mg group and 44 in the placebo group). In the intention-to-treat population, 60 (47%) of 128 patients treated with filgotinib 200 mg achieved clinical remission at week 10 versus ten (23%) of 44 patients treated with placebo (difference 24 percentage points 95% CI 9–39, p=0·0077). In a pooled analysis of all periods of filgotinib and placebo exposure over 20 weeks, serious treatment-emergent adverse effects were reported in 14 (9%) of 152 patients treated with filgotinib and three (4%) of 67 patients treated with placebo. Interpretation Filgotinib induced clinical remission in significantly more patients with active Crohn's disease compared with placebo, and had an acceptable safety profile. Funding Galapagos.
Background & Aims Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Mouse models of NAFLD have been used in studies of pathogenesis and ...treatment, and have certain features of the human disease. We performed a systematic transcriptome-wide analysis of liver tissues from patients at different stages of NAFLD progression (ranging from healthy obese individuals to those with steatosis), as well as rodent models of NAFLD, to identify those that most closely resemble human disease progression in terms of gene expression patterns. Methods We performed a systematic evaluation of genome-wide messenger RNA expression using liver tissues collected from mice fed a standard chow diet (controls) and 9 mouse models of NAFLD: mice on a high-fat diet (with or without fructose), mice on a Western-type diet, mice on a methionine- and choline-deficient diet, mice on a high-fat diet given streptozotocin, and mice with disruption of Pten in hepatocytes. We compared gene expression patterns with those of liver tissues from 25 patients with nonalcoholic steatohepatitis (NASH), 27 patients with NAFLD, 15 healthy obese individuals, and 39 healthy nonobese individuals (controls). Liver samples were obtained from patients undergoing liver biopsy for suspected NAFLD or NASH, or during liver or bariatric surgeries. Data sets were analyzed using the limma R-package. Overlap of functional profiles was analyzed by gene set enrichment analysis profiles. Results We found differences between human and mouse transcriptomes to be significantly larger than differences between disease stages or models. Of the 65 genes with significantly altered expression in patients with NASH and 177 genes with significantly altered expression in patients with NAFLD, compared with controls, only 1–18 of these genes also differed significantly in expression between mouse models of NAFLD and control mice. However, expression of genes that regulate pathways associated with the development of NAFLD were altered in some mouse models (such as pathways associated with lipid metabolism). On a pathway level, gene expression patterns in livers of mice on the high-fat diet were associated more closely with human fatty liver disease than other models. Conclusions In comparing gene expression profiles between liver tissues from different mouse models of NAFLD and patients with different stages of NAFLD, we found very little overlap. Our data set is available for studies of pathways that contribute to the development of NASH and NAFLD and selection of the most applicable mouse models ( http://www.nash-profiler.com ).
The recognition of autophagy related 16-like 1 (ATG16L1) as a genetic risk factor has exposed the critical role of autophagy in Crohn's disease. Homozygosity for the highly prevalent ATG16L1 risk ...allele, or murine hypomorphic (HM) activity, causes Paneth cell dysfunction. As Atg16l1(HM) mice do not develop spontaneous intestinal inflammation, the mechanism(s) by which ATG16L1 contributes to disease remains obscure. Deletion of the unfolded protein response (UPR) transcription factor X-box binding protein-1 (Xbp1) in intestinal epithelial cells, the human orthologue of which harbours rare inflammatory bowel disease risk variants, results in endoplasmic reticulum (ER) stress, Paneth cell impairment and spontaneous enteritis. Unresolved ER stress is a common feature of inflammatory bowel disease epithelium, and several genetic risk factors of Crohn's disease affect Paneth cells. Here we show that impairment in either UPR (Xbp1(ΔIEC)) or autophagy function (Atg16l1(ΔIEC) or Atg7(ΔIEC)) in intestinal epithelial cells results in each other's compensatory engagement, and severe spontaneous Crohn's-disease-like transmural ileitis if both mechanisms are compromised. Xbp1(ΔIEC) mice show autophagosome formation in hypomorphic Paneth cells, which is linked to ER stress via protein kinase RNA-like endoplasmic reticulum kinase (PERK), elongation initiation factor 2α (eIF2α) and activating transcription factor 4 (ATF4). Ileitis is dependent on commensal microbiota and derives from increased intestinal epithelial cell death, inositol requiring enzyme 1α (IRE1α)-regulated NF-κB activation and tumour-necrosis factor signalling, which are synergistically increased when autophagy is deficient. ATG16L1 restrains IRE1α activity, and augmentation of autophagy in intestinal epithelial cells ameliorates ER stress-induced intestinal inflammation and eases NF-κB overactivation and intestinal epithelial cell death. ER stress, autophagy induction and spontaneous ileitis emerge from Paneth-cell-specific deletion of Xbp1. Genetically and environmentally controlled UPR function within Paneth cells may therefore set the threshold for the development of intestinal inflammation upon hypomorphic ATG16L1 function and implicate ileal Crohn's disease as a specific disorder of Paneth cells.
Clinical trials of Crohn's disease generally use the Crohn's Disease Activity Index to assess disease activity; these calculations are complex, time-consuming, and impracticable. We investigated ...whether a simpler tool, the Harvey-Bradshaw Index, was equally effective in assessing disease severity.
Crohn's Disease Activity and Harvey-Bradshaw Index scores were collected from 2 large multicenter Crohn's disease studies. The PEGylated antibody fragment evaluation in Crohn's disease: safety and efficacy (PRECiSE) 1 and 2 trials assessed efficacy and tolerability of certolizumab pegol (PEGylated, humanized, Fab' fragment of an antitumor necrosis factor alpha antibody). PRECiSE 1 and 2 data were analyzed to determine if results from the Crohn's Disease Activity Index correlated with those from the Harvey-Bradshaw Index criteria for defining response and remission.
Analysis of almost 1000 data pairs showed a positive correlation between scores. The correlation between the indices for pooled data from PRECiSE 1 and PRECiSE 2 was 0.800 (Spearman correlation coefficient). The correlations between indices for the PRECiSE 1 or PRECiSE 2 were 20.698 and 0.716, respectively (Kronecker product variance). A 3-point change in the Harvey-Bradshaw Index score corresponded to a 100-point change in the Crohn's Disease Activity Index (clinical response); scores < or =4 points corresponded to a Crohn's Disease Activity Index score < or =150 points (clinical remission).
Results from the Crohn's Disease Activity Index correlate with those from the Harvey-Bradshaw Index; use of the Harvey-Bradshaw Index might permit simpler Crohn's disease activity assessment in long-term clinical trials, and facilitate standardized disease activity measurements and cross-center comparisons.
PDF
