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BACKGROUND AND AIMS: There are no agreed-on endoscopic signs for the diagnosis of villous atrophy (VA) in celiac disease (CD), necessitating biopsy sampling for diagnosis. Here we evaluated the role of near-focus narrow-band imaging (NF-NBI) for the assessment of villous architecture in suspected CD with the development and further validation of a novel NF-NBI classification. METHODS: Patients with a clinical indication for duodenal biopsy sampling were prospectively recruited. Six paired NF white-light endoscopy (NF-WLE) and NF-NBI images with matched duodenal biopsy sampling including the bulb were obtained from each patient. Histopathology grading used the Marsh-Oberhuber classification. A modified Delphi process was performed on 498 images and video recordings by 3 endoscopists to define NF-NBI classifiers, resulting in a 3-descriptor classification: villous shape, vascularity, and crypt phenotype. Thirteen blinded endoscopists (5 expert, 8 nonexpert) then undertook a short training module on the proposed classification and evaluated paired NF-WLE-NF-NBI images. RESULTS: One hundred consecutive patients were enrolled (97 completed the study; 66 women; mean age, 51.2 ± 17.3 years). Thirteen endoscopists evaluated 50 paired NF-WLE and NF-NBI images each (24 biopsy-proven VAs). Interobserver agreement among all validators for the diagnosis of villous morphology using the NF-NBI classification was substantial (κ = .71) and moderate (κ = .46) with NF-WLE. Substantial agreement was observed between all 3 NF-NBI classification descriptors and histology (weighted κ = 0.72-.75) compared with NF-WLE to histology (κ = .34). A higher degree of confidence using NF-NBI was observed when assessing the duodenal bulb. CONCLUSIONS: We developed and validated a novel NF-NBI classification to reliably diagnose VA in suspected CD. There was utility for expert and nonexpert endoscopists alike, using readily available equipment and requiring minimal training. (Clinical trial registration number: NCT04349904.).
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Doença Celíaca , Adulto , Idoso , Atrofia/patologia , Doença Celíaca/diagnóstico por imagem , Duodeno/diagnóstico por imagem , Duodeno/patologia , Endoscopia , Feminino , Humanos , Pessoa de Meia-Idade , Imagem de Banda EstreitaRESUMO
OBJECTIVE: The early identification of primary non-response to anti-TNFα therapy facilitates the timely management of patients with Crohn's disease (CD). A recent, pilot study to detect prognostic markers of early response to anti-TNFα therapy identified the two genes coding for the calprotectin subunits (S100A8, S100A9) to be among the most highly expressed gene transcripts in non-responders. This study tests the hypothesis that measurements of faecal calprotectin (FCAL) pre- and post-anti-TNFα induction can predict primary non-response. METHODS: Retrospective study of 32 CD patients treated over a two-year period. Outcomes were assessed at 6 months based on clinical activity scores and the use of corticosteroids: (a) remission: Harvey-Bradshaw index (HBI) < 5, off corticosteroids >2 months; (b) response: drop in HBI >3, off corticosteroids; (c) non-response: ΔFCAL (and ΔCRP, respectively) was calculated as (FCAL post-induction - FCAL pre-induction) × 100/FCAL pre induction. RESULTS: At 6 months, 23 (72%) patients had responded (median (interquartile range) HBI: 4 (3-5), FCAL: 55 (27-146)), 17 (73%) of whom were in remission [HBI: 3 (2.5-4) and FCAL: 42 (16-115)]. There was a significant difference in the ΔFCAL from baseline to post-induction in the three groups (p < 0.0001). Comparing non-responders to combined response and remission groups, the AUC of ΔFCAL to predict outcome at 6 months was 0.97. Using ROC analysis, a Δ70% returned a sensitivity and specificity of 99% and 96%, respectively (likelihood ratio, LR= 23). ΔCRP did not predict 6 months outcomes. CONCLUSIONS: A drop in FCAL <70% after induction predicts primary non-response to anti-TNFα in CD.
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Corticosteroides/uso terapêutico , Doença de Crohn/terapia , Fármacos Gastrointestinais/administração & dosagem , Imunoterapia/métodos , Infliximab/administração & dosagem , Complexo Antígeno L1 Leucocitário/análise , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adolescente , Adulto , Anticorpos Monoclonais Humanizados , Biomarcadores , Bases de Dados Factuais , Fezes/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Falha de Tratamento , Reino Unido , Adulto JovemRESUMO
Crohn's disease (CD) and celiac disease (CelD) are chronic intestinal inflammatory diseases, involving genetic and environmental factors in their pathogenesis. The two diseases can co-occur within families, and studies suggest that CelD patients have a higher risk to develop CD than the general population. These observations suggest that CD and CelD may share common genetic risk loci. Two such shared loci, IL18RAP and PTPN2, have already been identified independently in these two diseases. The aim of our study was to explicitly identify shared risk loci for these diseases by combining results from genome-wide association study (GWAS) datasets of CD and CelD. Specifically, GWAS results from CelD (768 cases, 1,422 controls) and CD (3,230 cases, 4,829 controls) were combined in a meta-analysis. Nine independent regions had nominal association p-value <1.0 x 10â»5 in this meta-analysis and showed evidence of association to the individual diseases in the original scans (p-value < 1 x 10⻲ in CelD and < 1 x 10⻳ in CD). These include the two previously reported shared loci, IL18RAP and PTPN2, with p-values of 3.37 x 10â»8 and 6.39 x 10â»9, respectively, in the meta-analysis. The other seven had not been reported as shared loci and thus were tested in additional CelD (3,149 cases and 4,714 controls) and CD (1,835 cases and 1,669 controls) cohorts. Two of these loci, TAGAP and PUS10, showed significant evidence of replication (Bonferroni corrected p-values <0.0071) in the combined CelD and CD replication cohorts and were firmly established as shared risk loci of genome-wide significance, with overall combined p-values of 1.55 x 10⻹° and 1.38 x 10⻹¹ respectively. Through a meta-analysis of GWAS data from CD and CelD, we have identified four shared risk loci: PTPN2, IL18RAP, TAGAP, and PUS10. The combined analysis of the two datasets provided the power, lacking in the individual GWAS for single diseases, to detect shared loci with a relatively small effect.
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Doença Celíaca/genética , Doença de Crohn/genética , Proteínas Ativadoras de GTPase/genética , Predisposição Genética para Doença , Hidroliases/genética , Subunidade beta de Receptor de Interleucina-18/genética , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Interpretação Estatística de Dados , Estudo de Associação Genômica Ampla , Humanos , Fatores de RiscoRESUMO
Celiac disease (CD) is an intolerance to dietary proteins of wheat, barley, and rye. CD may have substantial morbidity, yet it is quite common with a prevalence of 1%-2% in Western populations. It is not clear why the CD phenotype is so prevalent despite its negative effects on human health, especially because appropriate treatment in the form of a gluten-free diet has only been available since the 1950s, when dietary gluten was discovered to be the triggering factor. The high prevalence of CD might suggest that genes underlying this disease may have been favored by the process of natural selection. We assessed signatures of selection for ten confirmed CD-associated loci in several genome-wide data sets, comprising 8154 controls from four European populations and 195 individuals from a North African population, by studying haplotype lengths via the integrated haplotype score (iHS) method. Consistent signs of positive selection for CD-associated derived alleles were observed in three loci: IL12A, IL18RAP, and SH2B3. For the SH2B3 risk allele, we also show a difference in allele frequency distribution (Fst) between HapMap phase II populations. Functional investigation of the effect of the SH2B3 genotype in response to lipopolysaccharide and muramyl dipeptide revealed that carriers of the SH2B3 rs3184504*A risk allele showed stronger activation of the NOD2 recognition pathway. This suggests that SH2B3 plays a role in protection against bacteria infection, and it provides a possible explanation for the selective sweep on SH2B3, which occurred sometime between 1200 and 1700 years ago.
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Infecções Bacterianas/genética , Doença Celíaca/genética , Suscetibilidade a Doenças , Proteína Adaptadora de Sinalização NOD2/genética , Polimorfismo de Nucleotídeo Único , Proteínas/genética , Seleção Genética , Proteínas Adaptadoras de Transdução de Sinal , África do Norte , Europa (Continente) , Evolução Molecular , Genética Populacional , Humanos , Peptídeos e Proteínas de Sinalização IntracelularRESUMO
Many disease-associated variants identified by genome-wide association (GWA) studies are expected to regulate gene expression. Allele-specific expression (ASE) quantifies transcription from both haplotypes using individuals heterozygous at tested SNPs. We performed deep human transcriptome-wide resequencing (RNA-seq) for ASE analysis and expression quantitative trait locus discovery. We resequenced double poly(A)-selected RNA from primary CD4(+) T cells (n = 4 individuals, both activated and untreated conditions) and developed tools for paired-end RNA-seq alignment and ASE analysis. We generated an average of 20 million uniquely mapping 45 base reads per sample. We obtained sufficient read depth to test 1371 unique transcripts for ASE. Multiple biases inflate the false discovery rate which we estimate to be approximately 50% for random SNPs. However, after controlling for these biases and considering the subset of SNPs that pass HapMap QC, 4.6% of heterozygous SNP-sample pairs show evidence of imbalance (P < 0.001). We validated four findings by both bacterial cloning and Sanger sequencing assays. We also found convincing evidence for allelic imbalance at multiple reporter exonic SNPs in CD6 for two samples heterozygous at the multiple sclerosis-associated variant rs17824933, linking GWA findings with variation in gene expression. Finally, we show in CD4(+) T cells from a further individual that high-throughput sequencing of genomic DNA and RNA-seq following enrichment for targeted gene sequences by sequence capture methods offers an unbiased means to increase the read depth for transcripts of interest, and therefore a method to investigate the regulatory role of many disease-associated genetic variants.
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Desequilíbrio Alélico/genética , Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla , Ensaios de Triagem em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Alelos , Pareamento de Bases/genética , Viés , Células Cultivadas , Biologia Computacional , Doença/genética , Epigênese Genética , Reações Falso-Positivas , Loci Gênicos/genética , Heterozigoto , Humanos , Polimorfismo de Nucleotídeo Único/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos TestesRESUMO
Objective: Faecal calprotectin (fCAL) is an established marker of intestinal inflammation in inflammatory bowel disease (IBD). Disproportionally high fCAL levels, for the severity of intestinal inflammation, have been previously observed in primary sclerosing cholangitis associated IBD (PSC-IBD). The aim of this study was to test the hypothesis that fCAL is a marker of biliary injury in PSC-IBD. Methods: We used two cohorts: (1) post hoc analysis of a colonoscopic surveillance study allowing correlation of fCAL to endoscopic severity as measured by the ulcerative colitis endoscopic index of severity (UCEIS) in PSC-IBD (n=20) and ulcerative colitis (UC, n=20) and (2) prospective recruitment of patients attending for endoscopic retrograde cholangiopancreatography allowed the correlation of fCAL to biliary calprotectin (n=8). Results: A strong correlation was seen between fCAL and UCEIS in UC (r=0.821, 95% CI (0.585 to 0.929), p<0.0001). In PSC-IBD, the correlation was weaker (r=0.596, 95% CI (0.195 to 0.8260), p=0.006). PSC-IBD patients with endoscopically quiescent colitis (UCEIS: 0-1) had higher fCAL than patients with UC (279 µg/g, IQR (68-601) vs 30 µg/g, IQR (14-107), p=0.015). This was associated with higher risk of biliary complications like need for antibiotics or instrumentation (HR 16.39, 95% CI (2.98 to 90.25)) rather than colitis flares (follow-up: 12 months). Calprotectin measured in faeces correlated positively with biliary calprotectin (r=0.898, p=0.0024). Conclusion: fCAL is a surrogate marker for biliary inflammation in PSC-IBD. Trial registration number: NCT02543021.
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BACKGROUND & AIMS: Autoimmune sclerosing cholangitis (ASC) is a childhood sclerosing cholangitis frequently associated with inflammatory bowel disease (IBD). We describe the IBD phenotype in ASC patients and associated liver disease outcomes. METHODS: Single center retrospective observational review of ASC patients, with a control population of pediatric IBD. Demographic and clinical parameters were obtained. Clinical endpoints were escalation of IBD therapy (biologic or colectomy) and transplant-free survival. RESULTS: In 93 ASC patients (53.8% female) and median follow up of 172 months: 70% had IBD, 25.8% underwent liver transplant. Median age at liver transplant was 21.7 years, at 131 months from ASC diagnosis. There was no association between presence of IBD and transplant-free survival, whilst those requiring second-line immunomodulators for ASC had poorer long-term liver prognosis. During follow-up 22 (33.8%) ASC-IBD required biologic or colectomy. On multivariate analysis ASC was associated with a lower risk of escalation of IBD therapy (HR 0.14, 95% CI 0.05-0.42; P=.001), including biologic therapy (HR 0.21, 95% CI 0.08-0.55, P=.002), but not colectomy on univariate analysis (HR 1.54, 95% CI 0.43-5.44, P=.51). CONCLUSIONS: IBD is common in ASC and during longterm follow up a third of ASC-IBD required escalation of IBD therapy; however ASC-IBD was lower risk compared to IBD alone. IBD does not appear to impact on transplant-free survival in patients with ASC, however second-line immunomodulators for ASC are associated with poorer IBD and liver outcomes.
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Produtos Biológicos , Colangite Esclerosante , Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Hepatopatias , Colangite Esclerosante/complicações , Colangite Esclerosante/epidemiologia , Colite Ulcerativa/diagnóstico , Doença de Crohn/complicações , Feminino , Humanos , Doenças Inflamatórias Intestinais/complicações , Hepatopatias/complicações , Masculino , Estudos Retrospectivos , Fatores de RiscoRESUMO
Background: Sequential drug treatment with biological agents in ulcerative colitis (UC) is becoming increasingly complex. There are few studies comparing head-to-head outcomes in second-line treatments. The study assesses whether using anti-tumour necrosis factor (anti-TNF)-α therapy following the α4ß7 integrin blocker vedolizumab (VDZ) or VDZ after an anti-TNF has more favourable clinical outcomes in UC in a real-world outpatient setting. Methods: Patients with UC who were exposed to first-line anti-TNF (adalimumab or infliximab) or VDZ who subsequently switched to the alternate class between May 2013 and August 2020 were identified by reviewing patient databases at 10 hospitals. Data were collected retrospectively using patient records. Baseline demographics, disease activity indices, biochemical markers, endoscopic Mayo score, colectomy rates, treatment persistence and urgent hospital utilisation composite endpoint (UHUC) rates were examined over a 52-week period. Results: Second-line week 52 treatment persistence was higher in the VDZ group (71/81, 89%) versus the anti-TNF group (15/34, 44%; p=0.0001), as were week 52 colectomy-free survival (VDZ: 77/80, 96%, vs anti-TNF: 26/32, 81%; p=0.009), week 52 UHUC survival (VDZ: 68/84, 81%, vs anti-TNF: 20/34, 59%; p=0.002) and week 52 corticosteroid-free clinical remission (CFCR) rates (VDZ: 22/34, 65%, vs anti-TNF: 4/20, 20%; p=0.001). Conclusion: Compared with second-line anti TNF usage, the VDZ second-line cohort had significantly higher 52-week treatment persistence, UHUC survival, higher colectomy-free survival rates and higher week 52 CFCR. These data suggest that VDZ is an effective biologic in UC as a second-line therapy after anti-TNF exposure. It highlights the effect of biological order on clinically important outcomes.
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Coeliac disease is caused by dietary gluten, triggering a chronic inflammation of the small intestine in genetically predisposed individuals. Recently, a risk locus on chromosome 2q11-q12, harbouring interleukin 18 receptor accessory protein (IL18RAP) and three other genes, was suggested for coeliac disease. IL18 has been shown to play an important role in T helper type 1 activity in coeliac disease, making this locus a highly interesting candidate. In this study, two previously indicated risk variants at the IL18RAP locus (rs13015714 and rs917997) were tested for genetic association in 1638 cases with coeliac disease and 1385 control individuals from the Finnish, Hungarian and Italian populations. The protein expression level of IL18RAP was also compared between risk allele carriers and non-carriers by Western blotting. Furthermore, immunohistochemical analysis was performed to study IL18RAP protein expression in small intestinal biopsies of untreated and treated coeliac patients and controls. We confirmed genetic association and dose effects of variants at the 2q12.1 locus with coeliac disease in the Hungarian population. The GA haplotype of the markers rs13015714 and rs917997 showed the strongest association (P = 0.0001, odds ratio = 1.475, 95% confidence interval 1.21-1.80). Two putative isoforms of IL18RAP were detected and the ratios and total levels of these isoforms may contribute to the aetiology of coeliac disease. Our study supports IL18RAP as a novel predisposing gene for coeliac disease and highlights the need for further functional studies on this relatively unknown gene in coeliac disease pathogenesis.
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Doença Celíaca/genética , Predisposição Genética para Doença , Subunidade beta de Receptor de Interleucina-18/genética , População Branca/genética , Western Blotting , Feminino , Humanos , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Leucócitos/metabolismo , Masculino , Metanálise como AssuntoRESUMO
BACKGROUND: Two inflammatory disorders, type 1 diabetes and celiac disease, cosegregate in populations, suggesting a common genetic origin. Since both diseases are associated with the HLA class II genes on chromosome 6p21, we tested whether non-HLA loci are shared. METHODS: We evaluated the association between type 1 diabetes and eight loci related to the risk of celiac disease by genotyping and statistical analyses of DNA samples from 8064 patients with type 1 diabetes, 9339 control subjects, and 2828 families providing 3064 parent-child trios (consisting of an affected child and both biologic parents). We also investigated 18 loci associated with type 1 diabetes in 2560 patients with celiac disease and 9339 control subjects. RESULTS: Three celiac disease loci--RGS1 on chromosome 1q31, IL18RAP on chromosome 2q12, and TAGAP on chromosome 6q25--were associated with type 1 diabetes (P<1.00x10(-4)). The 32-bp insertion-deletion variant on chromosome 3p21 was newly identified as a type 1 diabetes locus (P=1.81x10(-8)) and was also associated with celiac disease, along with PTPN2 on chromosome 18p11 and CTLA4 on chromosome 2q33, bringing the total number of loci with evidence of a shared association to seven, including SH2B3 on chromosome 12q24. The effects of the IL18RAP and TAGAP alleles confer protection in type 1 diabetes and susceptibility in celiac disease. Loci with distinct effects in the two diseases included INS on chromosome 11p15, IL2RA on chromosome 10p15, and PTPN22 on chromosome 1p13 in type 1 diabetes and IL12A on 3q25 and LPP on 3q28 in celiac disease. CONCLUSIONS: A genetic susceptibility to both type 1 diabetes and celiac disease shares common alleles. These data suggest that common biologic mechanisms, such as autoimmunity-related tissue damage and intolerance to dietary antigens, may be etiologic features of both diseases.
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Autoimunidade/genética , Doença Celíaca/genética , Diabetes Mellitus Tipo 1/genética , Proteínas Adaptadoras de Transdução de Sinal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/genética , Antígeno CTLA-4 , Doença Celíaca/imunologia , Criança , Pré-Escolar , Proteínas do Citoesqueleto/genética , Diabetes Mellitus Tipo 1/imunologia , Feminino , Ligação Genética , Predisposição Genética para Doença , Humanos , Lactente , Subunidade p35 da Interleucina-12/genética , Subunidade beta de Receptor de Interleucina-18/genética , Subunidade alfa de Receptor de Interleucina-2/genética , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas com Domínio LIM , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Proteínas/genética , Proteínas RGS/genética , Receptores CCR5/genética , Adulto JovemRESUMO
BACKGROUND AND AIMS: Certain foods are reported as gut symptom triggers in inflammatory bowel disease [IBD], and fructans are shown to worsen non-inflammatory symptoms in inactive IBD, which may result in self-imposed dietary restrictions. The aim of this study was to investigate nutrient and FODMAP intakes, and the relationship between gut symptoms and dietary intake, in IBD. METHODS: Nutrient, fibre, and FODMAP intakes were estimated using 7-day food records in patients with active IBD [Active IBD], inactive IBD with non-inflammatory gut symptoms [Inactive IBD-GI], inactive IBD without gut symptoms [Inactive IBD], and healthy controls. Nutrient intakes, numbers of participants achieving national recommendations, and food-related quality of life [FR-QoL] were compared across study groups. RESULTS: Food diaries were obtained from 232 patients with IBD [65 Active IBD, 86 Inactive IBD-GI, 81 Inactive IBD] and 84 healthy controls. Patients with Active IBD had significantly lower intakes of numerous micronutrients, including iron, folate, and vitamin C, compared with controls. All IBD groups consumed less total fibre [4.5 to 5.8 g/day] than controls [p = 0.001], and total FODMAP and fructan intakes were lower in Active IBD compared with controls. Strikingly, FR-QoL was significantly lower in all IBD groups compared with controls [all p = 0.001]. CONCLUSIONS: This study revealed lower intakes of fibre, FODMAPs, and micronutrients, in addition to poorer FR-QoL, in Active IBD and Inactive IBD-GI with gut symptoms compared with healthy controls. Future research should address dietary restrictions responsible for these differences.
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Fibras na Dieta , Ingestão de Alimentos , Doenças Inflamatórias Intestinais/dietoterapia , Nutrientes , Índice de Gravidade de Doença , Adulto , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Doenças Inflamatórias Intestinais/patologia , Masculino , Qualidade de VidaRESUMO
OBJECTIVES: This study aimed to identify the relationship between adherence to a gluten-free diet (GFD) and demographic characteristics, knowledge, attitudes, and beliefs regarding celiac disease (CD) and GFD, experiences of following a GFD, symptoms, and quality of life (QoL). METHODS: Patients with CD were recruited from outpatient clinics. Adherence to GFD was assessed using the CD adherence test (CDAT) and GFD score (GFD-S). Knowledge, attitudes, experiences, symptoms, and QoL were assessed using existing questionnaires. A multivariate logistic regression was performed. RESULTS: Overall, 116 patients with CD were included (48 ± 16 y; 70% female). Based on the CDAT, 58 patients (50%) were adequate adherers, but 86 patients (74%) were adequate adherers according to GFD-S. When adherence was measured using the CDAT, being female was associated with lower odds of adherence (odds ratio [OR]: 0.36; P = 0.028), and better emotional wellbeing was associated with higher odds of adherence (OR: 1.19; P < 0.001). When adherence was measured using GFD-S, membership in a support group (OR: 6.17; P = 0.002), stronger beliefs about the chronicity of CD (OR: 1.15; P = 0.059), and weaker beliefs on accident/chance causing CD (OR: 1.94; P = 0.05) were associated with greater odds of adherence. Difficulties when eating with family/friends (OR: 0.98; P = 0.005) and weaker beliefs on immunity causing CD (OR: 0.77; P = 0.031) were associated with lower odds of adherence. CONCLUSIONS: The association between gender, attending support groups, attitudes, experiences, and QoL with adherence to a GFD should be considered by health care professionals managing patients with CD.
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Doença Celíaca , Qualidade de Vida , Dieta Livre de Glúten , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Cooperação do PacienteRESUMO
From the discovery of functionally graded laminated composites, to near-structurally optimized diagonally reinforced square lattice structures, the skeletal system of the predominantly deep-sea sponge Euplectella aspergillum has continued to inspire biologists, materials scientists and mechanical engineers. Building on these previous efforts, in the present study, we develop an integrated finite element and fluid dynamics approach for investigating structure-function relationships in the complex maze-like organization of helical ridges that surround the main skeletal tube of this species. From these investigations, we discover that not only do these ridges provide additional mechanical reinforcement, but perhaps more significantly, provide a critical hydrodynamic benefit by effectively suppressing von Kármán vortex shedding and reducing lift forcing fluctuations over a wide range of biologically relevant flow regimes. By comparing the disordered sponge ridge geometry to other more symmetrical strake-based vortex suppression systems commonly employed in infrastructure applications ranging from antennas to underwater gas and oil pipelines, we find that the unique maze-like ridge organization of E. aspergillum can completely suppress vortex shedding rather than delaying their shedding to a more downstream location, thus highlighting their potential benefit in these engineering contexts.
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Vidro , HidrodinâmicaRESUMO
Students in first-year university courses often focus on mimicking application of taught procedures and fail to gain adequate conceptual understanding. One potential approach to support meaningful learning is Productive Failure (PF). In PF, the conventional instruction process is reversed so that learners attempt to solve challenging problems ahead of receiving explicit instruction. While students often fail to produce satisfactory solutions (hence "Failure"), these attempts help learners encode key features and learn better from subsequent instruction (hence "Productive"). Effectiveness of PF was shown mainly in the context of statistical and intuitive concepts, and lessons that are designed and taught by learning scientists. We describe a quasi-experiment that evaluates the impact of PF in a large-enrollment introductory university-level biology course when designed and implemented by the course instructors. One course-section (295 students) learned two topics using PF; another section (279 students) learned the same topics using an active learning approach, which is the standard in this course. Performance was assessed on the subsequent midterm exam, after all students had ample opportunities for practice and feedback, and after some time has elapsed. PF students scored nearly five percentage-points higher on the relevant topics in the subsequent midterm exam. The effect was especially strong for low-performing students. Improvement on the final exam was only visible for low-performing students. We describe the intervention and its potential to transform large introductory university courses.
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BACKGROUND: Chromoendoscopy (CE) is the recommended surveillance technique for colitis, but uptake has been limited and the literature provides scant information on patient experience (PE); imperative to adherence to surveillance programmes. Virtual CE (VCE) by Fujinon Intelligent Colour Enhancement digitally reconstructs mucosal images in real time, without the technical challenges of CE. We performed a multifaceted randomized crossover trial (RCT) to evaluate study feasibility and obtain preliminary comparative procedural and PE data. METHODS: Patients were randomized to undergo either CE with indigo carmine or VCE as the first procedure. After 3-8 weeks, participants underwent colonoscopy with the second technique. Patient recruitment/retention, missed dysplasia, prediction of dysplasia, and contamination (memory/sampling of the first procedure) were recorded. PE was assessed by validated questionnaires, and pain was assessed using a visual analog scale (mm). RESULTS: Sixty patients were recruited, and 48 patients (first procedure: 23 VCE, 25 CE) completed the trial (retention 80%) with no episodes of contamination. Eleven dysplastic lesions were detected in n = 7/48 (14.5%). VCE missed 1 lesion, and CE missed 2 lesions in n = 2 (data of VCE vs CE, respectively, for dysplasia diagnostic accuracy: 93.94% [85.2%-98.32%] vs 76.9% [66.9%-98.2%]; examination time [minutes]: 14 +/- 4 vs 20 +/- 7 (95% confidence interval, 3.5 to 8; P < 0.001); pain (mm): 27.4 +/- 17.5 vs 34.7 +/- 18; patient preference: 67% [n = 31] vs 33% [n = 15] in n = 46; P < 0.001). CONCLUSIONS: This is the first RCT to include validated PE in a colitis surveillance program. VCE is safe, technically easier, quicker, and more comfortable test, with dysplasia detection at least as good as that of CE, overcoming many barriers to the wider adoption of CE. This trial may serve as a successful foundation for a a multicenter trial to confirm the value of VCE for colitis surveillance.
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Colite/complicações , Neoplasias do Colo/diagnóstico , Detecção Precoce de Câncer/métodos , Endoscopia/métodos , Aceitação pelo Paciente de Cuidados de Saúde , Lesões Pré-Cancerosas/diagnóstico , Adolescente , Adulto , Idoso , Colite/diagnóstico por imagem , Colite/patologia , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/epidemiologia , Neoplasias do Colo/etiologia , Colonoscopia , Corantes , Estudos Cross-Over , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Lesões Pré-Cancerosas/diagnóstico por imagem , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/etiologia , Prognóstico , Reino Unido/epidemiologia , Adulto JovemRESUMO
Background: The SCENIC consensus statement recommends endoscopic resection of all visible dysplasia in inflammatory bowel disease, but patients with large or complex lesions may still be advised to have colectomy. This article presents outcomes for large nonpolypoid resections associated with colitis at our institution. Methods: Data including demographics, clinical history, lesion characteristics, method of resection, and postresection surveillance were collected prospectively in patients with visible lesions within colitic mucosa from January 2011 to November 2016. Resection techniques included endoscopic mucosal resection , endoscopic submucosal dissection (ESD), and hybrid ESD. Surveillance with magnification chromoendoscopy was performed at 3 months, 1-year postresection, and annually thereafter. Results: Fifteen lesions satisfied the inclusion criteria in 15 patients. Mean lesion size was 48.3+/-21.7 (20-90) mm. All lesions were non-polypoid with distinct margins and no ulceration. 73% lesions were scarred of which 64% had undergone prior instrumentation. En bloc resection was achieved in n=6. Presumed endoscopic diagnosis was confirmed histopathologically in all resected lesions. One case of perforation and another with bleeding were both managed endoscopically. Median follow-up was 28 months (12-35) with no recurrence. Conclusion: This cohort series demonstrates that endoscopic resection of large non-polypoid lesions associated with colitis is feasible and safe using an array of resection methods supporting the role of advanced endoscopic therapeutics for the management of colitis associated dysplasia in a western tertiary endoscopic center.
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Ressecção Endoscópica de Mucosa , Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/cirurgia , Mucosa Intestinal/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Colectomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Reino UnidoRESUMO
OBJECTIVE: To gain an understanding of the effectiveness of golimumab in a 'real-world' setting. DESIGN: Retrospective cohort study using prospectively maintained clinical records. SETTING: Two UK tertiary IBD centres. PATIENTS: Patients with ulcerative colitis (UC) were given golimumab at Guy's & St Thomas and King's College Hospitals between September 2014 and December 2016. INTERVENTION: Golimumab, a subcutaneously administered antitumour necrosis factor agent. MAIN OUTCOME MEASURES: Clinical disease activity was assessed at baseline and at the first clinical review following induction therapy using the Simple Clinical Colitis Activity Index (SCCAI). Response was defined as an SCCAI reduction of 3 points or more. Remission was defined as an SCCAI of less than 3. RESULTS: Fifty-seven patients with UC completed golimumab induction therapy. Paired preinduction and postinduction SCCAI values were available for 31 patients and fell significantly from 7 (2-19) to 3 (0-11) (p<0.001). To these 31, an additional 13 patients who did not have paired SCCAI data but stopped treatment due to documented 'non-response' in the opinion of their supervising clinician, were added. Among this combined cohort, 23/44 (52%) had a clinical response, 15/44 (34%) achieved remission and 13/44 (30%) achieved corticosteroid-free remission.Faecal calprotectin and CRP fell (FC: pre-induction: 1096 (15-4800) µg/g, post-induction: 114 (11-4800) µg/g, p = 0.011; n = 20; CRP: pre-induction: 4 (1-59) mg/L, post-induction: 2 (1-34) mg/L, p = 0.01 for n = 43). Post-induction endoscopy was carried out in 23 patients and a mucosal healing (Mayo 0 or 1) rate of 35% was observed. CONCLUSIONS: Our experience mirrors previously reported real-world cohorts and demonstrates similar outcomes to those observed in randomised controlled trials. These data demonstrate a meaningful reduction in clinical, biochemical and endoscopic disease activity as well as a steroid-sparing effect in patients with previously refractory disease.
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OBJECTIVE: The objective was to assess in an animal model the mechanical properties of five prostheses used for pelvic floor repair. STUDY DESIGN: Two months after pre-peritoneal implantation of the five types of prosthesis: Prolene, Prolene Soft, Mersuture, Vicryl and Vypro, we sacrificed the animals to measure retraction of the prosthesis, maximal resistance to traction, and maximal elongation. RESULTS: Non-absorbable prostheses retracted least. Forces at rupture were disparate with a significant difference in favor of Prolene (p<0.001). Resistance was variably affected by cicatrization. There were no significant differences in elongation. CONCLUSIONS: This study is an introductory exploration. Monofilament and macroporous propylene prostheses seem, after implantation, to have the best mechanical performance and best tissue integration. This underlines the need for experimental prostheses, which are increasingly used, but still lack the extensive evaluation needed by the surgeon. Knitted polypropylene seems to be one of the best materials at present, but is probably not sufficient.
Assuntos
Implantes Absorvíveis , Teste de Materiais , Implantação de Prótese , Slings Suburetrais , Telas Cirúrgicas , Animais , Fenômenos Biomecânicos , Modelos Animais de Doenças , Feminino , Projetos Piloto , Poliglactina 910/uso terapêutico , Polipropilenos/uso terapêutico , Sus scrofa , Resistência à TraçãoRESUMO
OBJECTIVE: To gain an understanding of the efficacy of vedolizumab in a 'real-world' setting. DESIGN: Retrospective cohort study using prospectively maintained clinical records. SETTING: Two UK tertiary inflammatory bowel disease (IBD) centres. PATIENTS: Patients with IBD commenced on vedolizumab at Guy's & St Thomas' and King's College Hospitals during November 2014-November 2015. INTERVENTION: Vedolizumab, a monoclonal antibody to α-4 ß-7 integrins that selectively inhibit leucocyte migration into the gut. MAIN OUTCOME MEASURES: Clinical disease activity was assessed at baseline, weeks 14 and 30 using Harvey-Bradshaw Index (HBI) for Crohn's disease (CD) and Simple Clinical Colitis Activity Index (SCCAI) for ulcerative colitis (UC). Response was defined as HBI or SCCAI reduction ≥3. Remission was defined as HBI <5 or SCCAI <3. Continuous data are summarised as medians, followed by range. RESULTS: Fifty patients were included: 27 CD, 20 UC and 3 IBD-U (included in the UC group for analysis). At baseline visit, the median HBI was 8 (1-16) and SCCAI was 6 (0-15). At week 14, these values had fallen to 5 (0-15) (p=0.117) and 4 (0-10) (p=0.005), respectively. Additionally, week 30 data were available for 19 patients (9 CD, 10 UC). The clinical disease activity scores at that point were HBI 2 (0-7) (p=0.039) and SCCAI 2 (0-10) (p=0.023). At baseline, 37 (74%) of the 50 patients had clinically active disease. Of the patients with active disease, 22 (59%) responded and 14 (38%) achieved remission at week 14. CONCLUSIONS: Our early experience with vedolizumab demonstrates a clear benefit in terms of disease control as well as a steroid-sparing effect in a cohort, which included patients with complex and previously refractory disease.
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INTRODUCTION: The "tension-free" procedures are widely used by surgeons for the treatment of urinary incontinence and prolapse. The clinical results are largely in favour of these procedures. The aim of our study is to determine objectively the mechanical tissue resistance when using these techniques, before healing begins. MATERIAL AND METHODS: We measured the mechanical resistance using four different routes: the retro-pubic space, the transobturator, the translevator ani muscle and the trans-sacrospinous ligament. We compared five different meshes, TVT, IVS, Lift, Prolene and Prolene Soft. In order to study the effect of increasing dimensions, we tested Prolene tapes measuring 1, 1.5 and 2 cm in width. We performed traction tests on meshes implanted in cadavers. Measurements were made with a dynamometer and the results expressed in Newtons. RESULTS: This study shows that TVT offers a better resistance to traction via the retro-pubic space route. There was no significant difference among the four routes when the same type of mesh measuring 1cm was used. However, an increase in the dimensions of Prolene tapes improves their resistance in the tissues, thereby facilitating fixation before healing begins. Also, these increasing dimensions (in width) show that there is better resistance with the trans-sacrospinous ligament compared with the transmuscular one. DISCUSSION: The increasing size of prosthetic meshes does not show the superiority of certain routes with commercial meshes of 1cm in width. The higher resistance obtained with wider tapes is probably due to an increased surface area between the tissues and meshes. This increase in resistance does not seem to be important for the treatment of urinary incontinence. However, it should be of interest for the treatment of prolapse where traction and surface are more important. CONCLUSION: Two different recommendations can be deduced from our study. On one hand, the arms of prosthetic meshes for pelvic floor repair should measure more than 1cm in width in order to improve their maintenance in the tissues in the immediate post-operative period. On the other hand to improve fixation, the posterior arms of the transperineal mesh should be passed through the sacrospinous ligament rather than via the transmuscular route. The resistance of tissues is also influenced by the armature of the prosthetic mesh. They must therefore be developed commercially specifically for "tension-free" fixation. Our results need to be confirmed by further studies including more cadavers and younger patients.