Determining the mechanisms by which genes are switched on and off during development is a key aim of current biomedical research. Gene transcription has been widely observed to occur in a discontinuous fashion, with short bursts of activity interspersed with periods of inactivity. It is currently not known if or how this dynamic behaviour changes as mammalian cells differentiate. To investigate this, using an on-microscope analysis, we monitored mouse α-globin transcription in live cells throughout erythropoiesis. We find that changes in the overall levels of α-globin transcription are most closely associated with changes in the fraction of time a gene spends in the active transcriptional state. We identify differences in the patterns of transcriptional bursting throughout differentiation, with maximal transcriptional activity occurring in the mid-phase of differentiation. Early in differentiation, we observe increased fluctuation in transcriptional activity whereas at the peak of gene expression, in early erythroblasts, transcription is relatively stable. Later during differentiation as α-globin expression declines, we again observe more variability in transcription within individual cells. We propose that the observed changes in transcriptional behaviour may reflect changes in the stability of active transcriptional compartments as gene expression is regulated during differentiation.

Over the past 50 years erythropoiesis and globin gene expression has played a central role as a model to establish the principles by which mammalian genes are switched on and off during development and differentiation. In addition, investigating how gene expression is perturbed in the haemoglobinopathies has pioneered our understanding of the molecular basis of human disease. A key question has been to understand the molecular and cellular basis of the normal switch between the genes encoding the fetal form of haemoglobin (HbF: 22) and those encoding adult globin (HbA: 22).

During the early stages of postnatal development, in concert with the radial expansion of the skull, the mechanical properties of the calvarial bones change and the visible gaps at the sutures reduce to micro/nanometer gaps where the sutures differentiate to bone. Our understanding of the level of loading that sutures experience during the development is limited. The aim of this study was to develop a validated finite element (FE) model of a normal mouse calvarial growth to estimate the level of mechanical strain that sutures undergo during the development and to predict the pattern of bone formation at these joints.

There is a shortage of monoclonal antibodies (Mabs) against the Duffy b antigen (Fyb). Anti-Fy antibodies are clinically significant, particularly in multiply transfused individuals and have been implicated in fatal transfusion reactions (Cotorruelo et al., 2009). The Fyb differs from the Fya antigen by a single-point mutation at position 42 (glycine in Fya and aspartic acid in Fyb). In the absence of experimental structural data, it was proposed to model the Fya antibody–antigen interactions in silico and predict amino acid mutations that would shift the specificity of the antibody from Fya to Fyb. In silico modelling was assessed using all-atom explicit molecular dynamics (MD). Candidate double or triple amino acid mutants were proposed, for which MD suggested an altered specificity of the antibody, increasing the stability of the modelled Fyb peptide–antibody complex. The variable regions of a monoclonal anti-Fya antibody were engineered into a single-chain variable fragment (scFv) and translationally fused to either maltose-binding protein (MBP) or bacteriophage in order to make the system more amenable to forward genetic engineering in bacteria and to test candidate mutants using purified recombinant protein. A first generation of mutations was postulated: in vitro binding assays with recombinant protein suggested a shift in specificity from Fya to Fyb in a triple mutant. This framework may now serve as the basis for further efforts to engineer novel specificities in an antibody and possibly the development of a novel, monoclonal, Fyb typing reagent. Financial contributor: Biorad

Introduction Seventeen thousand patients are treated with radical pelvic radiotherapy annually in the UK.50% develop chronic GI symptoms. The structured approach to management used in this service evaluation has been shown to identify treatable diagnoses and improve symptoms in the short term. We report the first 12 month outcome data for the effect of structured gastroenterological evaluation on symptom burden and patient satisfaction. Methods Fifty-six patients with GI symptoms > 6 months after radical pelvic radiotherapy underwent structured gastroenterological assessment as part of a service evaluation. They were assessed using the following questionnaires: inflammatory bowel disease questionnaire(IBDQ); Vaizey incontinence questionnaire (VIQ); and the Common Terminology Criteria for Adverse Events (CTCAE)pelvic symptom questionnaire.12 month assessments were compared to the previously reported baseline and 6 month assessments to determine if the improvement in symptoms was sustained. Patient satisfaction with the service was assessed at 12 months by an in-house questionnaire. Results Forty patients(71%)completed the 12 month assessment and 37(66%) completed the patient satisfaction questionnaire. The initial statistically significant improvement in GI symptoms from baseline to 6 months in parallel to GI evaluation was sustained up to 12 months in all questionnaires (IBDQ p = 0.019, IBDQB and CTCAE rectum bowel subset p < 0.0005) except the VIQ (p = 0.098).There was also a clinically significant improvement as defined by an increase in IBDQ score of ≥0.5 points per question. Median total IBDQ and IBDQB score increased by 25 and 11 points respectively between baseline and 12 months.97% of patients found the appointments convenient, 97% felt their problems were understood; 86% were satisfied with the outcome and 89% with the service. Dissatisfaction related to communication (n = 3), travel (n = 2) and ongoing symptoms (n = 3). Conclusion The clinically and statistically significant improvement in GI symptoms found in parallel to structured gastroenterological evaluation for chronic GI symptoms following pelvic radiotherapy was sustained over 12 months follow up. These data suggest that structured investigation on the basis of the BSG guidelines can lead to a sustained improvement in symptoms and is acceptable to patients. Further research is essential to optimise patient care. Disclosure of Interest None Declared.

Fifty percent of patients develop chronic gastrointestinal (GI) symptoms following pelvic radiotherapy that adversely affect quality of life. Fewer than 20 % are referred to a gastroenterologist. We aimed to determine if structured gastroenterological evaluation is of benefit to this patient group.

Introduction EMR is an established treatment for large colorectal polyps, yet the data regarding efficacy and outcome are principally limited to single centre experience. We present a multicentre study to determine prognostic factors of short-term (3 month) and long-term (1 year) outcomes following an index (intention to treat (ITT)) EMR for large sessile colorectal polyps. Methods Endoscopy databases & hospital coding records identified patients that had an ITT EMR for colonic polyps 2 cm or greater between 2005 and 2010 in five North-West teaching hospitals. Patients were audited longitudinally for 1 year. Multivariate analysis (Logistic Regression Model) determined significant prognostic factors (OR [95% CI]; p<0.05 as significant). Results Demographics: 313 patients (mean [SD] age 69.7[10.4] years, 65.5% male, 86% ASA grade 1–2) underwent EMR for mean polyp size of 33.5 [11.5] mm. Morphologically; 63.8% were flat lesions and 21.7% were located in the right colon. Procedure: 26% were performed by inexperienced endoscopists (Outcomes: Cancer diagnosis was in 9.5% (6.3% invasive & 3.2% intra-mucosal). Complications; Perforation rate 0.5%, bleeding rate 0.5% & all cause 30-day mortality 0.6 %, with no procedure related mortality. Recurrence rate was 26% & treated endoscopically in 64.6%, & surgically in 8.5%. Overall, surgery was required in 7.3%, of which 8.7% were emergencies (to treat perforation) and 56% was for cancer. ITT short-term success rate was 68% and 1-year success rate was 82.4%, with an adjusted rate of 87.2%. Prognostic Factors: Predictors of recurrence were cancer histology (OR 9 [95% CI 4 to 22]=<0.05), piecemeal resection (OR 4 [95% CI 1.5 to 11] p<0.005) and EMR session >1 (OR 22 [95% CI 10 to 50] p<0.005). Poor prognostic indicators for long-term success were cancer (OR 11 [95% CI 4.5 to 28] p<0.005) and EMR session >1 (OR 3.6 [95% CI 1.5 to 8.4] p=0.003). While endoscopist inexperience, increasing polyp size, no adjuvant APC were poor prognostic factors univariately, on multivariate analysis they were insignificant. Gender, age, ASA, Training, site, morphology and complications were not significant factors. Conclusion While recurrence rates in EMR for large colonic lesions were high (>1/4), long-term outcomes were good (cure rate 87.2%) with complications similar to previous series. Most important poor prognostic factors were cancer histology and requirement of more than 1 session. Competing interests J Geraghty grant/research support from: Cook Medical, K Bodger: None declared, S Alam: None declared, W Jafar: None declared, M Gillon: None declared, C Babbs: None declared, J Ramesh: None declared, R Willert: None declared, S Lal: None declared, S Sarkar: None declared.

Introduction 17 000 patients are treated with radical pelvic radiotherapy per year in the UK. Although 50% develop significant chronic gastrointestinal (GI) symptoms, <20% are referred for gastroenterological evaluation. We aimed to determine the causes of GI symptoms in this patient group. Methods 60 patients with GI symptoms ≥6 months after radical pelvic radiotherapy were identified from oncology clinics. Those requiring urgent investigation via the 2-week wait pathway were excluded. Baseline characteristics including demographic data, cancer treatment details and symptoms were collected. Patients were referred for gastroenterological evaluation using an algorithmic approach, which involves the identification of all GI symptoms and investigation for all potential causes for the individual symptoms. Details of investigations and diagnoses were collected. Results 20 men and 36 women with primary gynaecological (31), urological (17) or lower GI (8) tumours were included, with a median age of 58.5 years (range 26.9–81.8). As part of their cancer treatment 15 patients also had brachytherapy, 28 had chemotherapy and 25 had surgery. Patients presented with multiple GI symptoms (median 8, range 4–16) including frequency (46), urgency (52), loose stool (50), faecal incontinence (40), flatulence (43), bloating/distension (38) and rectal bleeding (29). The median number of investigations per patient was 9 (range 1–17), including routine blood tests (47), coeliac screen (39), breath tests for small bowel bacterial overgrowth (21) and lactose intolerance (16), SeHCAT scans (27) and upper (27) and lower (38) GI endoscopy. Common diagnoses include radiation proctopathy (22) and bile acid mabsorption (12). Some diagnoses are unrelated to previous radiotherapy, for example, diverticulosis (9) and colonic polyps (8). No cause was found for symptoms in seven patients. 25 patients have 2 or more GI diagnoses. Conclusion Gastroenterological evaluation identifies significant and potentially treatable diagnoses in patients who develop chronic GI symptoms following pelvic radiotherapy. Some findings are incidental and some are unrelated to previous cancer treatment. GI symptoms in these patients have historically been considered “untreatable”. These data suggest that structured gastroenterological assessment has the potential to improve outcome by identifying these diagnoses and facilitating focussed treatment. Competing interests None declared.

We read with considerable interest the review “Minimizing occupational hazards in endoscopy: personal protective equipment, radiation safety, and ergonomics” by Pedrosa et al1 from the American Society for Gastrointestinal Endoscopy Technology Committee and wished to share our own experience of endoscopy overuse injuries from a United Kingdom perspective. From a questionnaire survey sent to 143 gastroenterologists in the northwest of England, we had a response rate of 41% (58) and found that 57% reported pain in at least one anatomical region more than once a week during endoscopy.

this study.This parameter is also highly controversial and questionable.The number of ''abnormal'' lymph nodes is assessed, but it is unknown whether they fulfilled all abnormal characteristics or only 1 of them.What is the significance of a lymph node with nondistinct borders classified as abnormal?Are the abnormal lymph nodes truly abnormal (ie, malignant)?Even if all of them would really be malignant, would that be of any clinical significance?Anyone familiar with the use of EUS already knows that linear echo-endoscopes have better echo-penetration and resolution, with which more detailed structures can be identified, while on the other hand this type of endoscope has limitations in orientation.Thus, although Tstaging with a radial EUS scope may indeed be better than linear, this was not proven convincingly by the data from this study, given the number of flaws mentioned above.

This is an introduction to the Gut tutorial “A patient with impaired gastric motility” hosted on BMJ Learning—the best available learning website for medical professionals from the BMJ Group. The functional as opposed to inflammatory effects of gastrointestinal pathology are often neglected by clinicians. Helicobacter pylori infection may impair gastric function either due to …

Perlyn, Chad A. MD; Babbs, Christian DPhil; Ornitz, David MD, PhD; Morriss-Kay, Gillian PhD, DSc Author Information

The otic vesicle (otocyst) occupies a pivotal position in inner ear development, bridging the gap between otic placode determination, and morphogenesis of vestibular and auditory compartments. The molecular mechanisms underlying the progressive subdivision of the developing inner ear into different compartments, and the molecular control and execution of the different developmental processes involved, are largely unknown. Since relatively few genes have been implicated in these processes, we have undertaken this study to identify genes involved in these early embryonic stages. We have used cDNA subtractions of mouse otic vesicle against adult liver cDNA, and describe a set of 280 candidate genes. We have also performed otic vesicle RNA hybridizations against DNA chips to not only confirm the efficacy of the library approach, but also to investigate the utility of DNA array alternatives. To begin to dissect potential developmental roles, we investigated the spatial pattern of gene expression for a selected set of 80 genes in developing mouse embryos at mid-gestation by whole-mount in situ hybridization. These data illustrate the compartmentalisation of gene expression in the otic vesicle for the majority of genes tested, and furthermore, implicate many of the genes tested with distinct developmental subprocesses.