Crohn's disease and ulcerative colitis, collectively known as IBD, are chronic inflammatory disorders of the gastrointestinal tract. Although the aetiopathogenesis of IBD is largely unknown, it is ...widely thought that diet has a crucial role in the development and progression of IBD. Indeed, epidemiological and genetic association studies have identified a number of promising dietary and genetic risk factors for IBD. These preliminary studies have led to major interest in investigating the complex interaction between diet, host genetics, the gut microbiota and immune function in the pathogenesis of IBD. In this Review, we discuss the recent epidemiological, gene-environment interaction, microbiome and animal studies that have explored the relationship between diet and the risk of IBD. In addition, we highlight the limitations of these prior studies, in part by explaining their contradictory findings, and review future directions.
Early mobilisation is recommended following total hip arthroplasty (THA) or total knee arthroplasty (TKA) to prevent venous thromboembolism (VTE). We sought to determine the proportions of patients ...that first mobilised on post-operative day 0 (POD 0) and factors associated with earlier time to mobilisation.
A prospective cohort study was conducted involving patients with hip or knee osteoarthritis who had undergone primary unilateral THA (n = 818) and TKA (n = 989) at 19 Australian hospitals. Patient-related (e.g. age, gender, body mass index), treatment-related (e.g. hospital site, presence of indwelling catheter) and mobilisation-related variables were collected on standardised forms. Time was measured by post-operative days, where POD 0 was defined as the day of surgery ending at midnight. Multivariate Poisson regression analysis identified associations between patient- and treatment-related covariates and time to mobilisation.
Inter-hospital variation was evident, but overall, only 9.4% of THA and 5.6% of TKA patients mobilised on POD 0. For THA patients, earlier time to mobilisation was associated with hospital site and absences of an indwelling catheter and acute complications. For TKA patients, earlier time to mobilisation was associated with hospital site and absence of donor blood transfusion.
Few THA and TKA patients mobilise POD 0, although some hospitals appear more aggressive with their mobilisation attempts than others. Treatment-related factors, not patient-related, are associated with post-operative day of mobilisation, indicating the potentially pivotal role of service providers in promoting early mobilisation to improve health outcomes and reduce rates of VTE.
To examine the relationship between Mediterranean diet and risk of later-onset Crohn's disease (CD) or ulcerative colitis (UC).
We conducted a prospective cohort study of 83 147 participants (age ...range: 45-79 years) enrolled in the Cohort of Swedish Men and Swedish Mammography Cohort. A validated food frequency questionnaire was used to calculate an adherence score to a modified Mediterranean diet (mMED) at baseline in 1997. Incident diagnoses of CD and UC were ascertained from the Swedish Patient Register. We used Cox proportional hazards modelling to calculate HRs and 95% CI.
Through December of 2017, we confirmed 164 incident cases of CD and 395 incident cases of UC with an average follow-up of 17 years. Higher mMED score was associated with a lower risk of CD (P
=0.03) but not UC (P
=0.61). Compared with participants in the lowest category of mMED score (0-2), there was a statistically significant lower risk of CD (HR=0.42, 95% CI 0.22 to 0.80) but not UC (HR=1.08, 95% CI 0.74 to 1.58). These associations were not modified by age, sex, education level, body mass index or smoking (all P
>0.30). The prevalence of poor adherence to a Mediterranean diet (mMED score=0-2) was 27% in our cohorts, conferring a population attributable risk of 12% for later-onset CD.
In two prospective studies, greater adherence to a Mediterranean diet was associated with a significantly lower risk of later-onset CD.
Summary Background Colorectal cancer is the third most common cancer worldwide and has a high mortality rate. We tested the hypothesis that only one flexible sigmoidoscopy screening between 55 and 64 ...years of age can substantially reduce colorectal cancer incidence and mortality. Methods This randomised controlled trial was undertaken in 14 UK centres. 170 432 eligible men and women, who had indicated on a previous questionnaire that they would accept an invitation for screening, were randomly allocated to the intervention group (offered flexible sigmoidoscopy screening) or the control group (not contacted). Randomisation by sequential number generation was done centrally in blocks of 12, with stratification by trial centre, general practice, and household type. The primary outcomes were the incidence of colorectal cancer, including prevalent cases detected at screening, and mortality from colorectal cancer. Analyses were intention to treat and per protocol. The trial is registered, number ISRCTN28352761. Findings 113 195 people were assigned to the control group and 57 237 to the intervention group, of whom 112 939 and 57 099, respectively, were included in the final analyses. 40 674 (71%) people underwent flexible sigmoidoscopy. During screening and median follow-up of 11·2 years (IQR 10·7–11·9), 2524 participants were diagnosed with colorectal cancer (1818 in control group vs 706 in intervention group) and 20 543 died (13 768 vs 6775; 727 certified from colorectal cancer 538 vs 189). In intention-to-treat analyses, colorectal cancer incidence in the intervention group was reduced by 23% (hazard ratio 0·77, 95% CI 0·70–0·84) and mortality by 31% (0·69, 0·59–0·82). In per-protocol analyses, adjusting for self-selection bias in the intervention group, incidence of colorectal cancer in people attending screening was reduced by 33% (0·67, 0·60–0·76) and mortality by 43% (0·57, 0·45–0·72). Incidence of distal colorectal cancer (rectum and sigmoid colon) was reduced by 50% (0·50, 0·42–0·59; secondary outcome). The numbers needed to be screened to prevent one colorectal cancer diagnosis or death, by the end of the study period, were 191 (95% CI 145–277) and 489 (343–852), respectively. Interpretation Flexible sigmoidoscopy is a safe and practical test and, when offered only once between ages 55 and 64 years, confers a substantial and longlasting benefit. Funding Medical Research Council, National Health Service R&D, Cancer Research UK, KeyMed.
Making predictions about the rewards associated with environmental stimuli and updating those predictions through feedback is an essential aspect of adaptive behavior. Theorists have argued that ...dopamine encodes a reward prediction error (RPE) signal that is used in such a reinforcement learning process. Recent work with fMRI has demonstrated that the BOLD signal in dopaminergic target areas meets both necessary and sufficient conditions of an axiomatic model of the RPE hypothesis. However, there has been no direct evidence that dopamine release itself also meets necessary and sufficient criteria for encoding an RPE signal. Further, the fact that dopamine neurons have low tonic firing rates that yield a limited dynamic range for encoding negative RPEs has led to significant debate about whether positive and negative prediction errors are encoded on a similar scale. To address both of these issues, we used fast-scan cyclic voltammetry to measure reward-evoked dopamine release at carbon fiber electrodes chronically implanted in the nucleus accumbens core of rats trained on a probabilistic decision-making task. We demonstrate that dopamine concentrations transmit a bidirectional RPE signal with symmetrical encoding of positive and negative RPEs. Our findings strengthen the case that changes in dopamine concentration alone are sufficient to encode the full range of RPEs necessary for reinforcement learning.
Pain affects approximately 80% of patients with pancreatic cancer, with half requiring strong opioid analgesia, namely: morphine-based drugs on step three of the WHO analgesic ladder (as opposed to ...the weak opioids: codeine and tramadol). The presence of pain is associated with reduced survival. This article reviews the literature regarding pain: prevalence, mechanisms, pharmacological, and endoscopic treatments and identifies areas for research to develop individualized patient pain management pathways. The online literature review was conducted through: PubMed, Clinical Key, Uptodate, and NICE Evidence. There are two principal mechanisms for pain: pancreatic duct obstruction and pancreatic neuropathy which, respectively, activate mechanical and chemical nociceptors. In pancreatic neuropathy, several histological, molecular, and immunological changes occur which correlate with pain including: transient receptor potential cation channel activation and mast cell infiltration. Current pain management is empirical rather etiology-based and is informed by the WHO analgesic ladder for first-line therapies, and then endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) in patients with resistant pain. For EUS-CPN, there is only one clinical trial reporting a benefit, which has limited generalizability. Case series report pancreatic duct stenting gives effective analgesia, but there are no clinical trials. Progress in understanding the mechanisms for pain and when this occurs in the natural history, together with assessing new therapies both pharmacological and endoscopic, will enable individualized care and may improve patients’ quality of life and survival.
T follicular helper (Tfh) cells are a critical component of adaptive immunity and assist in optimal Ab‐mediated defense. Multiple effector functions of Tfh support germinal center B cell survival, Ab ...class switching, and plasma cell maturation. In the past 2 decades, the phenotype and functional characteristics of GC Tfh have been clarified allowing for robust studies of the Th subset including activation signals and environmental cues controlling Tfh differentiation and migration during an immune response. A unique, 2‐step differentiation process of Tfh has been proposed but the mechanisms underlying transition between unstable Tfh precursors and functional mature Tfh remain elusive. Likewise, newly identified transcriptional regulators of Tfh development have not yet been incorporated into our understanding of how these cells might function in disease. Here, we review the signals and downstream transcription factors that shape Tfh differentiation including what is known about the epigenetic processes that maintain Tfh identity. It is proposed that further evaluation of the stepwise differentiation pattern of Tfh will yield greater insights into how these cells become dysregulated in autoimmunity.
Graphical
Transcriptional regulation and epigenetic remodeling stabilize Tfh subset identity and require multiple APC‐mediated stages of activation
Microbiome dysbiosis predisposes to colorectal cancer (CRC), but a population-based study of oral antibiotic exposure and risk patterns is lacking.
To assess the association between oral antibiotic ...use and CRC risk.
A matched case-control study (incident CRC cases and up to five matched controls) was performed using the Clinical Practice Research Datalink from 1989 to 2012.
28 980 CRC cases and 137 077 controls were identified. Oral antibiotic use was associated with CRC risk, but effects differed by anatomical location. Antibiotic use increased the risk of colon cancer in a dose-dependent fashion (p
<0.001). The risk was observed after minimal use, and was greatest in the proximal colon and with antibiotics with anti-anaerobic activity. In contrast, an inverse association was detected between antibiotic use and rectal cancers (p
=0.003), particularly with length of antibiotic exposure >60 days (adjusted OR (aOR), 0.85, 95% CI 0.79 to 0.93) as compared with no antibiotic exposure. Penicillins, particularly ampicillin/amoxicillin increased the risk of colon cancer (aOR=1.09 (1.05 to 1.13)), whereas tetracyclines reduced the risk of rectal cancer (aOR=0.90 (0.84 to 0.97)). Significant interactions were detected between antibiotic use and tumour location (colon vs rectum, p
<0.001; proximal colon versus distal colon, p
=0.019). The antibiotic-cancer association was found for antibiotic exposure occurring >10 years before diagnosis (aOR=1.17 (1.06 to 1.31)).
Oral antibiotic use is associated with an increased risk of colon cancer but a reduced risk of rectal cancer. This effect heterogeneity may suggest differences in gut microbiota and carcinogenesis mechanisms along the lower intestinal tract.
► Lysyl oxidase (LOX) is a critical enzyme for collagen cross-linking. ► Rat cardiac fibroblasts were used to study TGF-β1 regulation of LOX. ► TGF-β1 increased LOX mRNA, protein and activity. ► ...TGF-β1 activated PI3K/Akt, Smad and MAPK signaling pathways. ► Inhibition of PI3K, Smad3, p38-MAPK, ERK1/2, or JNK blocked TGF-β1 increase of LOX.
Lysyl oxidase (LOX) is a key extracellular enzyme responsible for the post-translational modification of collagens I and III to form mature fibrillar collagen. Increased expression of LOX is associated with fibrosis and cardiac dysfunction, yet little is known about the regulation of LOX in the heart. In this study, the cell signaling pathways responsible for the regulation of LOX expression by transforming growth factor (TGF)-β1 were assessed. Adult cardiac fibroblasts were isolated from male Sprague–Dawley rat hearts by enzymatic digestion. Fibroblasts were grown in DMEM with 10% FBS until approximately 80% confluent, growth arrested for 24
h, and then treated with TGF-β1 (0–10
ng/ml), in the absence or presence of inhibitors of (1) PI3K (wortmannin), (2) Smad3 (SIS3), (3) p38-MAPK (PD169316), (4) JNK (SP600125) and (5) ERK1/2 (PD98059). TGF-β1 treatment significantly upregulated LOX mRNA and protein expression in cardiac fibroblasts, as well as activity in the cell-conditioned media. Concomitant increases in collagen types I and III, and bone morphogenic protein (BMP-1) expression were found in response to TGF-β1. The increase of LOX protein in response to TGF-β1 was prevented by inhibitors of PI3K, Smad3, p38-MAPK, JNK and ERK1/2. Blockade of PI3K also decreased TGF-β1 induced phosphorylation of Smad3, suggesting that the PI3K/Akt and Smad pathways may be integrated in TGF-β1 signaling. Further studies are warranted to address the regulation of LOX in the normal and diseased heart, and how this critical extracellular enzyme may be targeted for clinical benefit.
Pancreatic ductal adenocarcinoma has the worst prognosis of any cancer. New adjuvant chemotherapies are urgently required, which are well tolerated by patients with unresectable cancers. This paper ...reviews the existing proof of concept data, namely laboratory, pharmacoepidemiological, experimental medicine and clinical trial evidence for investigating metformin in patients with pancreatic ductal adenocarcinoma. Laboratory evidence shows metformin inhibits mitochondrial ATP synthesis which directly and indirectly inhibits carcinogenesis. Drug–drug interactions of metformin with proton pump inhibitors and histamine H2-receptor antagonists may be of clinical relevance and pertinent to future research of metformin in pancreatic ductal adenocarcinoma. To date, most cohort studies have demonstrated a positive association with metformin on survival in pancreatic ductal adenocarcinoma, although there are many methodological limitations with such study designs. From experimental medicine studies, there are sparse data in humans. The current trials of metformin have methodological limitations. Two small randomized controlled trials (RCTs) reported null findings, but there were potential inequalities in cancer staging between groups and poor compliance with the intervention. Proof of concept data, predominantly from laboratory work, supports assessing metformin as an adjunct for pancreatic ductal adenocarcinoma in RCTs. Ideally, more experimental medicine studies are needed for proof of concept. However, many feasibility criteria need to be answered before such trials can progress.
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