US Army basic combat training alters the relationship between body mass index and per cent body fat

INTRODUCTION/BACKGROUND

As a proxy for adiposity, body mass index (BMI) provides a practical public health metric to counter obesity-related disease trends. On an individual basis, BMI cannot distinguish fat and lean components of body composition. Further, the relationship between BMI and body composition may be altered in response to physical training. We investigated this dynamic relationship by examining the effect of US Army basic combat training (BCT) on the association between BMI and per cent body fat (%BF).

METHODS

BMI and %BF were measured at the beginning (week 1) and end (week 9) of BCT in female (n=504) and male (n=965) trainees. Height and weight were obtained for BMI, and body composition was obtained by dual X-ray absorptiometry. Sensitivity and specificity of BMI-based classification were determined at two BMI thresholds (25 kg/m2 and 27.5 kg/m2).

RESULTS

A progressive age-related increase in fat-free mass index (FFMI) was observed, with an inflection point at age 21 years. In soldiers aged 21+, BMI of 25.0 kg/m2 predicted 33% and 29% BF in women and 23% and 20% BF in men and BMI of 27.5 kg/m2 predicted 35% and 31% BF in women and 26% and 22% BF in men, at the start and end of BCT, respectively. Sensitivity and specificity of BMI-based classification of %BF were poor. Soldiers below BMI of 20 kg/m2 had normal instead of markedly reduced %BF, reflecting especially low FFMI.

CONCLUSIONS

BCT alters the BMI-%BF relationship, with lower %BF at a given BMI by the end of BCT compared with the beginning, highlighting the unreliability of BMI to try to estimate body composition. The specific BMI threshold of 25.0 kg/m2, defined as 'overweight', is an out-of-date metric for health and performance outcomes. To the extent that %BF reflects physical readiness, these data provide evidence of a fit and capable military force at BMI greater than 25.0 kg/m2.

Review article: Mechanisms underlying the effectiveness of exclusive enteral nutrition in Crohn's disease

BACKGROUND

Exclusive enteral nutrition (EEN) induces remission and mucosal healing in patients with Crohn's disease, but the mechanism of action remains unknown.

AIM

To outline current understanding of the mechanisms of action of EEN.

METHODS

From a comprehensive literature search, published data were critically examined in a narrative review.

RESULTS

Multiple potential mechanisms of action have been identified. EEN optimises nutritional status. Differences in gut microbiota in terms of overall diversity and taxonomic community structure are observed between responders and non-responders to EEN. Therapy with EEN alters microbial metabolites (including faecal short-chain fatty acids, amino acids, branched-chain amino acids and sulphide) and faecal pH. Epithelial effects and restoration of barrier function, as well as changes in mucosal cytokine profiles and T-cell subsets are observed in responders to EEN. The impact of inclusion or exclusion of specific dietary components may be of importance, but putative detrimental components are found in many formulas. A major challenge in interpreting these findings is that they often contradict or change in opposite directions to what is considered 'beneficial'. It is difficult to differentiate between the observations following EEN being driven by EEN per se and those associated with resolving inflammation.

CONCLUSIONS

The mechanisms of action of EEN are likely to involve a complex interplay between host mucosal immune response and luminal environment, but the identity of key factors remains poorly understood. A better definition of pathogenic factors may aid in developing more targeted dietary treatment and provide insights into the pathogenesis of Crohn's disease.

Lessons from an audit of exclusive enteral nutrition in adult inpatients and outpatients with active Crohn's disease: a single-centre experience

OBJECTIVE

To evaluate clinical outcomes, patterns of use, tolerance and nutritional outcomes of exclusive enteral nutrition (EEN) in adults with Crohn's disease and to compare initiation in the inpatient compared with ambulatory care setting.

DESIGN/METHOD

Adults with Crohn's disease who received EEN at a single centre over 2.5 years were identified and outcomes assessed via examination of patient records.

RESULTS

EEN was initiated in 60 patients (23 as an outpatient) who had objective evidence of active disease. Of 49 in whom the goal was induction of remission, 28 completed EEN and 24 achieved clinical remission/response. Twenty-one withdrew prematurely, due to intolerance in 15 and disease factors in 6. Of 11 with a planned intervention, 6 fulfilled the goal of downstaging disease while two were intolerant. Completion of the prescribed therapy was associated with self-reported adherence to EEN and with improvements in disease activity scores and biochemical markers. Malnutrition halved (40% to 20%) and intentional weight loss (median 5.1 kg) was achieved in six obese patients. The major reason for intolerance was the inability to accept total avoidance of non-formula food. There were no differences in any outcomes according to the location of initiation of therapy.

CONCLUSION

Positive outcomes occur in 70% of adult patients with Crohn's disease tolerating EEN and 81% in those who are able to completely adhere to EEN, without compromise of nutritional status. Similar success occurs when initiated as an inpatient or outpatient. Failure to tolerate EEN is the major hurdle to its use.

Early sonographic response to a new medical therapy is associated with future treatment response or failure in patients with inflammatory bowel disease

OBJECTIVE

Gastrointestinal ultrasound (GIUS) accurately assesses inflammation and is responsive to changes in inflammatory bowel disease. This study aimed to determine the prognostic utility of sonographic response in the first 14 weeks of a newly-instituted therapy with therapeutic response at 46 weeks and to compare its performance with standard clinical assessment tools.

METHODS

Patients with sonographic evidence of inflammation were assessed by GIUS, clinical activity, serum C-reactive protein and faecal calprotectin again 2, 6 and 14 weeks after commencing a new biologic or thiopurine. Treatment failure was defined as undergoing surgery, hospitalisation, escalation of dosage or introduction of new medication over 46-weeks' follow-up. Sonographic response was defined as a decrease in bowel wall thickness and improved vascularity.

RESULTS

In 31 patients (median age 49 years, 74% Crohn's disease), sonographic response at 14 weeks [OR 19.3, 95% confidence interval (CI), 3.23-101.10; P = 0.0054] and faecal calprotectin (P = 0.018), but no clinical disease activity or C-reactive protein, were predictive of subsequent treatment response. Sonographic response alone was predictive at week 6 (P = 0.016), but not week 2. 16% reduction in bowel wall thickness at 6 weeks (area-under-the-receiver-operator-curve=0.86; P = 0.002; sensitivity 72%, specificity 90%), with similar performance for 10% at 14 weeks, was associated with treatment response.

CONCLUSION

Sonographic response as early as 6 weeks after initiation of a new therapy may accurately predict treatment outcomes over 46 weeks and is superior to other markers used to monitor disease activity.

Nonspecific ileitis: Impact of histopathology and gastrointestinal ultrasound in achieving the diagnosis of Crohn's disease

Background and Aim

Nonspecific ileitis is inflammation of the ileum without specific diagnostic features. A minority may go on to develop Crohn's disease, but optimal pathways of further investigation have not been established. This study aimed to identify a cohort of patients with nonspecific ileitis and to determine the value of ileal histology and gastrointestinal ultrasound in identifying/excluding Crohn's disease.

Patients and Methods

In a retrospective analysis, all patients having nonspecific ileitis at colonoscopy from January 2010 to August 2021 were identified. Clinical associations with those subsequently diagnosed with Crohn's disease were examined with specific reference to ileal histology and gastrointestinal ultrasound.

Results

Of 29 638 procedures, 147 patients (0.5%) had nonspecific ileitis. Crohn's disease was subsequently diagnosed in 8 patients (5.4%) at a median of 148 (range 27–603) days after colonoscopy. The presence of chronic inflammation on ileal biopsies was more common in those subsequently diagnosed with Crohn's disease (63% vs 20%; P = 0.0145). On gastrointestinal ultrasound, none of the 26 patients with normal bowel wall thickness (<3 mm) were subsequently diagnosed with Crohn's disease, and repeat ultrasound in 15 patients 1 year later showed no change. Of the nine patients with abnormal sonographic findings, three were diagnostic for Crohn's disease. Repeat ultrasound revealed Crohn's disease in two, while four had resolution of the abnormal findings.

Conclusion

Although ileal histology was of limited value in identifying patients with nonspecific ileitis who were subsequently diagnosed with Crohn's disease, gastrointestinal ultrasound was highly informative. Prospective studies are needed to confirm the value of gastrointestinal ultrasound as a diagnostic and monitoring tool in this setting.

Interrater reliability of the assessment of disease activity by gastrointestinal ultrasound in a prospective cohort of patients with inflammatory bowel disease

OBJECTIVE

Gastrointestinal ultrasound is a radiological investigation for monitoring patients with inflammatory bowel disease. However, the reliability of the findings depends on the reproducibility of results between different operators. Thus, the study aim was to assess the interrater reliability of gastrointestinal ultrasound in individuals with inflammatory bowel disease between gastroenterologists with varying GIUS experience. .

METHODS

Patients were prospectively recruited at the commencement of a new medical therapy for a baseline assessment, with a second assessment at the end of treatment induction (3 months). Consecutive, blinded ultrasounds were performed by two operators for every test. Gastrointestinal ultrasound examination included assessment of bowel wall thickness, vascularity, wall stratification assessment, mesenteric hyperechogenicity and lymphadenopathy.

RESULTS

Forty-nine patients were recruited (Crohn's n = 27, ulcerative colitis n = 22) with 35 returning for a repeat assessment at 3 months. At baseline, the intraclass coefficient for bowel wall thickness was near perfect (0.882). By bowel segment, the closest correlation was in the terminal ileum and differences in bowel wall thickness were similar by disease subtype. All other ultrasound indices of disease activity demonstrated substantial to near-perfect agreement with Gwet's agreement coefficient: vascularity (0.681), wall stratification (0.685), mesenteric hyperechogenicity (0.841) and lymphadenopathy (0.633). Similar findings were seen at 3 months.

CONCLUSION

There is substantial agreement between operators of varying experience in gastrointestinal ultrasound findings in patients with Crohn's disease or ulcerative colitis and this is repeatedly demonstrated over time. Thus, a well-trained operator should be sufficient to assess disease activity in patients with inflammatory bowel disease.

Effects of fiber intake on intestinal pH, transit, and predicted oral mesalamine delivery in patients with ulcerative colitis

BACKGROUND AND AIM

Limited data are available on the effects of fermentable fiber in altering intestinal pH and transit to predict efficacy-based delivery profiles of pH-dependent mesalamine coatings in ulcerative colitis (UC). This study aimed to examine regional pH and transit after acute changes in fermentable fiber intake in quiescent UC patients and their effects on drug release systems.

METHODS

In a randomized, double-blind study, 18 patients with quiescent UC and 10 healthy controls were supplied meals high (13 g) or low (≤ 2 g) in fermentable fiber and subsequently ingested a wireless pH-motility capsule. After a ≥ 3-day washout, they crossed over to the other diet. Measurements of intestinal pH and transit were used to predict drug release for the various pH-dependent coatings.

RESULTS

Increasing fermentable fiber intake lowered overall (median 6.2 [6.1-6.7] vs low: 6.9 [range or interquartile range: 6.4-7.4]; P = 0.01) and distal pH (7.8 [7.3-8.1] vs 8.2 [8.0-8.5]; P = 0.04) in controls. In UC patients, only cecal pH was decreased (high: 5.1 [4.8-5.5] vs low: 5.5 [5.3-5.7]; P < 0.01). Colonic transit in the UC cohort varied widely after a low-fiber intake but tended to normalize after the high fermentable fiber intake. Hypothetical coating dissolution profiles were heterogeneous in UC patients, with a multi-matrix delayed release system having the highest likelihood of patients (20-40%) with incomplete dissolution, and predominant small intestinal dissolution predicted for Eudragit L (94% patients) and S (44-69%).

CONCLUSIONS

Patients with quiescent UC have abnormalities in intestinal pH and transit in response to acute changes in fermentable fiber intake. These have potentially detrimental effects on predicted luminal release patterns of pH-dependent 5-aminosalicylic acid release systems.

Early Assessment With Gastrointestinal Ultrasound in Patients Hospitalised for a Flare of Ulcerative Colitis and Predicting the Need for Salvage Therapy: A Pilot Study

Approximately 30% of patients hospitalised with severe ulcerative colitis do not respond to corticosteroids, but the decision to introduce salvage therapy is delayed to at least the third day of treatment, according to the widely applied Oxford criteria to assess response. This pilot study aimed to determine if gastrointestinal ultrasound performed on admission can predict steroid-refractory disease. In 10 consecutive patients with severe ulcerative colitis, gastrointestinal ultrasound was performed within 24 h of admission. Six patients failed corticosteroids and required infliximab salvage therapy. Colonic bowel wall thickness was a median of 4.6 mm (range 4.2-5.6 mm) in those responding to steroids compared with 6.2 mm (6-7.9 mm) in those requiring salvage therapy (p = 0.009). Any colonic segment with a bowel wall thickness of >6 mm was associated with the need for salvage therapy (p = 0.033). Gastrointestinal ultrasound may provide an early indication of poor corticosteroid response and enable a timelier introduction of salvage therapy in patients with severe ulcerative colitis.

Standardisation of intestinal ultrasound scoring in clinical trials for luminal Crohn's disease

BACKGROUND

Intestinal ultrasound (IUS) is a valuable tool for assessment of Crohn's disease (CD). However, there is no widely accepted luminal disease activity index.

AIMS

To identify appropriate IUS protocols, indices, items, and scoring methods for measurement of luminal CD activity and integration of IUS in CD clinical trials.

METHODS

An expert international panel of adult and paediatric gastroenterologists (n = 15) and radiologists (n = 3) rated the appropriateness of 120 statements derived from literature review and expert opinion (scale of 1-9) using modified RAND/UCLA methodology. Median panel scores of 1 to ≤3.5, >3.5 to <6.5 and ≥6.5 to 9 were considered inappropriate, uncertain and appropriate ratings respectively. The statement list and survey results were discussed prior to voting.

RESULTS

A total of 91 statements were rated appropriate with agreement after two rounds of voting. Items considered appropriate measures of disease activity were bowel wall thickness (BWT), vascularity, stratification and mesenteric inflammatory fat. There was uncertainty if any of the existing IUS disease activity indices were appropriate for use in CD clinical trials. Appropriate trial applications for IUS included patient recruitment qualification when diseased segments cannot be adequately assessed by ileocolonoscopy and screening for exclusionary complications. At outcome assessment, remission endpoints including BWT and vascularity, with or without mesenteric inflammatory fat, were considered appropriate. Components of an ideal IUS disease activity index were identified based upon panel discussions.

CONCLUSIONS

The panel identified appropriate component items and applications of IUS for CD clinical trials. Empiric evidence, and development and validation of an IUS disease activity index are needed.

The Role of Epidemiological Evidence from Prospective Population Studies in Shaping Dietary Approaches to Therapy in Crohn's Disease

SCOPE

The concept that dietary factors are key risk and preventive agents in the development of Crohn's disease (CD), while widely believed and supported by epidemiological evidence, has yet to lead to clear identification of those factors through clinical trials. The aims are to examine the strength of the epidemiological evidence of diet and its association with CD, examine how interpretation of mostly epidemiological data has shaped ideas for potential dietary therapies, and to explore other factors that have driven the design of dietary clinical trials in CD.

METHODS

A literature search is performed in PubMed, Medline, EMBASE, and Google Scholar for prospective cohort studies and randomized clinical trials (RCTs) using search terms-"Crohn's disease," "diet," "risk," "remission," "treat," "cohort," "randomised."

RESULTS

Only four prospective cohort studies examine the relationship of diet and CD development, but these trials have been largely ignored by dietary RCTs in CD, which have used predominantly exclusion diets in small populations without objective endpoint assessment. Only one demonstrated clinical benefit to intestinal inflammation.

CONCLUSION

Investment in large multicenter dietary clinical trials that focus on dietary inclusions with objective endpoint assessment are needed to provide safe, sustainable dietary therapy to patients with CD.

Cytomegalovirus in inflammatory bowel disease: a clinical approach

Cytomegalovirus (CMV) infection can be a challenging clinical problem in patients with inflammatory bowel disease (IBD), particularly ulcerative colitis. Clinical presentation is difficult to distinguish from an underlying disease flare. A number of diagnostic modalities are now available and when combined can aid clinicians in the identification of patients who are most likely to benefit from antiviral therapy. The aim of this article is to review the available literature and outline a practical approach to the diagnosis and management of CMV in patients with IBD. This article is protected by copyright. All rights reserved.

Systematic Review: Clinical Utility of Gastrointestinal Ultrasound in the Diagnosis, Assessment and Management of Patients With Ulcerative Colitis

BACKGROUND AND AIMS

Gastrointestinal ultrasound is useful in the assessment of patients with Crohn's disease, but its application in ulcerative colitis [UC] is less well established. Here we systematically review the role of gastrointestinal ultrasound in patients with UC.

METHODS

Searches of the PUBMED and EMBASE databases were performed with the following search strategy: [ultrasound OR sonography] AND [intestinal OR bowel] AND [ulcerative colitis OR inflammatory bowel disease]. The final search was performed in August 2019.

RESULTS

Of 6769 studies identified in the search with a further two studies found from other sources, 50 studies met the inclusion criteria. Increased bowel wall thickness and detection of increased blood flow by colour Doppler were the most often applied criteria for defining disease activity and distribution. When compared with other reference investigations, gastrointestinal ultrasound accurately determined disease extent, severity and response to medical therapy. While further information can be obtained from haemodynamic measurements of the abdominal vessels and contrast-enhanced ultrasound, their clinical value was uncertain. Likewise, hydrocolonic sonography has few advantages over standard gastrointestinal ultrasound examination. Of several scoring systems proposed, there is disparity between the measures and a general lack of validation. There has been limited application of gastrointestinal ultrasound in acute severe ulcerative colitis with toxic megacolon, and, while performing well in children, normal limits differ from those in adults.

CONCLUSION

Current evidence indicates that gastrointestinal ultrasound has utility in the non-invasive assessment of patients with UC. Continued advances in technology with better image resolution, validation of scoring systems and application at the point of care by gastroenterologists are likely to contribute to increased use of gastrointestinal ultrasound in routine clinical practice.

Genetic and Inflammatory Biomarkers Classify Small Intestine Inflammation in Asymptomatic First-degree Relatives of Patients With Crohn's Disease

BACKGROUND & AIMS

Relatives of individuals with Crohn's disease (CD) carry CD-associated genetic variants and are often exposed to environmental factors that increase their risk for this disease. We aimed to estimate the utility of genotype, smoking status, family history, and biomarkers can calculate risk in asymptomatic first-degree relatives of patients with CD.

METHODS

We recruited 480 healthy first-degree relatives (full siblings, offspring or parents) of patients with CD through the Guy's and St Thomas' NHS Foundation Trust and from members of Crohn's and Colitis, United Kingdom. DNA samples were genotyped using the Immunochip. We calculated a risk score for 454 participants, based on 72 genetic variants associated with CD, family history, and smoking history. Participants were assigned to highest and lowest risk score quartiles. We assessed pre-symptomatic inflammation by capsule endoscopy and measured 22 markers of inflammation in stool and serum samples (reference standard). Two machine-learning classifiers (elastic net and random forest) were used to assess the ability of the risk factors and biomarkers to identify participants with small intestinal inflammation in the same dataset.

RESULTS

The machine-learning classifiers identified participants with pre-symptomatic intestinal inflammation: elastic net (area under the curve, 0.80; 95% CI, 0.62-0.98) and random forest (area under the curve, 0.87; 95% CI, 0.75-1.00). The elastic net method identified 3 variables that can be used to calculate odds for intestinal inflammation: combined family history of CD (odds ratio, 1.31), genetic risk score (odds ratio, 1.14), and fecal calprotectin (odds ratio, 1.04). These same 3 variables were among the 5 factors associated with intestinal inflammation in the random forest model.

CONCLUSION

Using machine learning classifiers, we found that genetic variants associated with CD, family history, and fecal calprotectin together identify individuals with pre-symptomatic intestinal inflammation who are therefore at risk for CD. A tool for detecting people at risk for CD before they develop symptoms would help identify the individuals most likely to benefit from early intervention.

Review article: determination of the therapeutic range for therapeutic drug monitoring of adalimumab and infliximab in patients with inflammatory bowel disease

BACKGROUND

Clinical application of therapeutic drug monitoring (TDM) to optimise anti-TNF therapies in patients with IBD depends upon target ranges.

AIMS

To review methodology used to determine therapeutic ranges and critically compare and contrast its application to infliximab and adalimumab.

METHODS

A systematic review was performed, and relevant literature was summarised and critically examined.

RESULTS

Upper limits of the therapeutic range are determined by toxicity, a plateau response and cost. Lower limits are determined by optimal concentration on the target of action in vitro and/or in vivo, or by correlation of drug levels with clinical efficacy using area-under-receiver-operator-curve (AUROC) analysis. In 43 studies, there were huge variations in time at which infliximab and adalimumab levels were measured, the end-points used (clinical remission to mucosal healing), the clinical setting (active disease vs maintenance phase) and the reason for TDM (proactive vs reactive). In the maintenance phase for infliximab, lower trough limits 2.8-5.7 µg/mL are reported depending upon end-points used, with consistent AUROC 0.68-0.77. Adalimumab TDM targets are even less consistent with a lower limit 5.9-11.8 µg/mL (AUROC 0.66-0.83) in some studies, but no cut-off can be identified that is significantly associated with outcome in others, related to inherent pharmacokinetic and pharmacodynamic differences, and heterogeneity of study design.

CONCLUSIONS

Evidence for exposure-response relationship is stronger for infliximab than adalimumab. Due to heterogeneity in settings for drug level measurements, therapeutic ranges vary. These factors need to be taken into account when interpreting the evidence and extending this to therapeutic strategies for IBD patients.

Characterization of ulcerative colitis-associated constipation syndrome (proximal constipation)

BACKGROUND

The syndrome of constipation with other abdominal symptoms ("proximal constipation") in ulcerative colitis (UC) is commonly recognized by practitioners but is poorly described, with no recognized definition and little understanding with regard to prevalence and effect of therapies on disease outcomes. This study aimed to address these issues in a cross-sectional, consecutive series of patients with UC.

METHODS

A working definition of proximal constipation was established. Consecutive patients were recruited, and their disease activity, recent medications, and investigations plus abdominal symptoms were assessed at a study visit. Relevant clinical data were also extracted from medical records.

RESULTS

Of 125 patients with UC, (mean age 47, range 14-84 years, 61 male), 58 (46%) fulfilled the definition of proximal constipation. The main symptoms were reduced stool frequency (69%), hard stools (43%), abdominal pain (40%), excessive flatus (29%), straining (24%), and sensation of incomplete emptying (14%). Proximal constipation was associated with female gender (OR 3.45 [1.45-8.24]), left-sided (OR 2.84 [1.14-7.11]) and concurrently active disease (OR 5.56 [1.96-16.67]), but not age, disease duration or therapy. A total of 88% had an increase in anti-inflammatory therapy, with the use of laxatives or fiber supplements in 63% compared with 1.4% of those without proximal constipation.

CONCLUSIONS

Proximal constipation is common, and its risk increases in active and distal disease, especially in women. Validation of its definition and evaluation of therapeutic strategies are needed. A new term "ulcerative colitis-associated constipation syndrome" is proposed to more accurately depict its nature.

Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Evolution of treatment targets in IBD has increased the need for objective monitoring of disease activity to guide therapeutic strategy. Although mucosal healing is the current target of therapy in IBD, endoscopy is invasive, expensive and unappealing to patients. GI ultrasound (GIUS) represents a non-invasive modality to assess disease activity in IBD. It is accurate, cost-effective and reproducible. GIUS can be performed at the point of care without specific patient preparation so as to facilitate clinical decision-making. As compared with ileocolonoscopy and other imaging modalities (CT and MRI), GIUS is accurate in diagnosing IBD, detecting complications of disease including fistulae, strictures and abscesses, monitoring disease activity and detecting postoperative disease recurrence. International groups increasingly recognise GIUS as a valuable tool with paradigm-changing application in the management of IBD; however, uptake outside parts of continental Europe has been slow and GIUS is underused in many countries. The aim of this review is to present a pragmatic guide to the positioning of GIUS in IBD clinical practice, providing evidence for use, algorithms for integration into practice, training pathways and a strategic implementation framework.

Phosphorylation of zinc channel ZIP7 drives MAPK, PI3K and mTOR growth and proliferation signalling

Zinc is an essential trace element participating in diverse biological processes. Cellular zinc levels are strictly controlled by two families of transport proteins: ZIP channels (SLC39A) and ZnT transporters (SLC30A). ZIP channels increase cytosolic zinc levels by importing zinc into cells or releasing zinc from intracellular stores such as the ER. Among all the 14 human members of the ZIP family, ZIP7 is a gatekeeper of zinc release from intracellular stores, requiring post-translational activation by phosphorylation on residues S275 and S276, resulting in activation of multiple downstream pathways. Employing site-directed mutagenesis, we investigated the importance of these individual serine residues as well as other predicted phosphorylation sites on ZIP7, showing that all four sites are required for maximal ZIP7 activation. Using phosphor-protein arrays, we also discovered the major signalling pathways that were activated as a direct result of ZIP7-mediated zinc release from intracellular stores. These data reveal the role of ZIP7-mediated zinc release from intracellular stores in driving major pathways, such as MAPK, mTOR and PI3K-AKT, involved in providing cell survival and proliferation and often over activated in cancer.

Is there a role for thioguanine therapy in IBD in 2017 and beyond?

Conventional thiopurines are effective for the maintenance of remission of Crohn's disease and ulcerative colitis, however, up to half of patients are intolerant or unresponsive to these medications. Thioguanine is an alternative thiopurine that has shown efficacy in inflammatory bowel disease, and is particularly useful to circumvent certain side effects associated with conventional thiopurines, for example, pancreatitis. Its association with nodular regenerative hyperplasia of the liver has hindered its widespread use. Areas covered: We aim to outline the rational use of thioguanine, including safety monitoring, with particular regard to hepatotoxicity. A literature search was performed: PubMed was searched for full papers and abstracts published in English since January 2000 using the following terms, alone and in combination: 'azathioprine', 'thiopurine', 'Crohn's disease', 'inflammatory bowel disease', 'nodular regenerative hyperplasia', 'mercaptopurine', 'thioguanine', 'ulcerative colitis'. Further relevant papers were identified from the reference lists of selected papers. Expert commentary: Despite optimisation strategies such as metabolite measurements and the use of allopurinol, a significant proportion of patients will remain intolerant to thiopurines, especially those with allergic reactions, including pancreatitis. For this subgroup of patients we suggest that low dose thioguanine is an alternative to other therapies that are either parenteral or expensive.

Paediatric extracorporeal priming procedures: does low temperature priming promote histamine release?

We have recently reported pathologically elevated plasma histamine levels in adult patients undergoing cardiac surgery throughout the perioperative period. We have found markedly higher histamine levels in paediatric practice. The priming volume of the smallest extracorporeal systems is invariably greater than the circulating blood volume of neonates and infants, necessitating the use of stored donor blood in the initial priming procedure. In 40 paediatric cases, arbitrarily selected, sampling from the arterial port of the oxygenator prior to the initiation of bypass revealed massively elevated plasma histamine levels (>30ng/ml) in those extracorporeal circuits in which the priming volume was smallest and the priming temperature lowest - at 10-12°C. It is clear that the use of donor blood (in this series less than five days old) may contribute to the delivery of histamine into the paediatric patient's circulation at the onset of cardiopulmonary bypass and that the priming temperature may play a role.

Histamine release during cardiopulmonary bypass

Plasma histamine concentrations were measured in 15 adult patients undergoing open-heart surgery (coronary artery bypass grafting) and in three control patients undergoing major noncardiac surgery. Plasma histamine levels rose in both open-heart and control patients in the early phase of operation before the onset of cardiopulmonary bypass (CPB). In the open-heart patients, significant elevations in plasma histamine concentrations occurred in the first 30 minutes of CPB (p < 0.05) in spite of haemodilution (median 36%). Plasma histamine changed neither by the application of X-clamp nor by its removal. No significant differences were observed between pulsatile and nonpulsatile flow of bypass perfusion. Two of the three patients who required infusion of sodium nitroprusside had high concentrations of plasma histamine (over 2ng/ml) throughout the observation period. DC shock induced an immediate response in histamine release. In the immediate post-CPB period when spontaneous circulation was resumed, the open-heart surgery patients exhibited a second rapid rise in plasma histamine, significantly higher than in the control patients (p < 0.05) in whom elevation in plasma histamine levels was not seen in the postoperative period. One of the CPB patients with persistent high histamine in the postoperative period had severe bronchospasm. Thus, in patients undergoing open-heart surgery, histamine release occurs at the onset of CPB and soon after the discontinuation of CPB. H1 + H2 blockade may be indicated in those at risk from histamine-mediated responses or receiving sodium nitroprusside or DC shocks.

The effect of normothermic cardiopulmonary bypass on hepatic blood flow in the dog

Hepatic blood flow was investigated in two groups of eight anaesthetized dogs during and after one hour of either pulsatile or non-pulsatile cardiopulmonary bypass (CPB). Mean perfusion pressure was maintained at 60 mmHg. Hepatic arterial (HA) and portal venous (PV) blood flows were measured using electromagnetic flow probes, and hepatic O 2 consumption determined. The results demonstrate that: (a) pulsatile CPB reduces peripheral vascular resistance during and after perfusion, and more effectively preserves pump flow rate and cardiac output than non-pulsatile CPB; (b) total liver blood flow is sustained more effectively by pulsatile CPB than by non-pulsatile CPB due to relative preservation of both HA and PV flows; (c) hepatic O2 consumption is only marginally better preserved during and after pulsatile CPB than with non-pulsatile perfusion. We conclude that: (a) pulsatile CPB tends to maintain hepatic blood flow through a relative reduction in HA vascular resistance and an improvement in PV flow produced passively by a greater pump flow rate; (b) pulsatile CPB less effectively benefits hepatic O2 consumption because of poor O2 uptake from the hepatic PV blood supply.

Performance characteristics of a new arterial line filter

A new 40 micron polyester screen arterial line filter with integral automatic blood gas separator has been designed with the potential for improved removal characteristics for gas microbubbles and massive air. A simple in vitro evaluation has been carried out comparing the new filter (Pall EC+) against a standard widely-used reference arterial line filter (Pall EC 3840). The filters have been compared in terms of their haemodynamic performance, specifically pressure drop at incremental flow rates and haemolysis characteristics measuring generated plasma free haemoglobin. In addition, the relative abilities of the test and reference filters to remove gaseous microbubbles, and also to vent massive air introduced into the test circuits have been assessed using an ultrasound based microbubble detection system. The results of the studies indicate that the test and reference filters are identical in terms of haemodynamics, with maximal pressure drops of 30 mmHg at 4-5 litres mean flow rate. Neither filter is associated with significant haemolysis in bovine blood test circuits flowing at 4 I/min for 60 minutes. However, the EC+ filter has significantly superior performance over the reference EC 3840 filter in both microbubble removal and in removal of nitrogen gas introduced directly into the test circuit at up to 5 litres gas/min ( p < 0.01). The new EC+ filter appears to offer safety in terms of haemodynamics and haemolysis, while providing maximal protection against massive arterial gas embolism.

A double blind clinical trial of Iloprost during cardiopulmonary bypass

Twenty patients undergoing elective coronary surgery were randomized to receive either the prostacyclin analogue Iloprost (Zk 36374) 5 ng/kg/min for 30 minutes before cardiopulmonary bypass (CPB) increasing to 10 ng/kg/min during CPB, or placebo, to investigate any beneficial effect on platelet preservation, or protection of the central nervous system during clinical CPB. Originally 50 patients were to have entered the trial, but unacceptable hypotensive effects occu rred in five patients who received Iloprost, lead i ng to early data analysis. No significant improvement in platelet number, volume or function; bleeding time; arterial line filter δ dry weight; retinal microembolism; or neuropsychological function, attributable to Iloprost, could be identified. The role and optimal dose of Iloprost in clinical CPB remains to be established.

Optimization of conventional therapy in patients with IBD

The majority of patients with IBD use conventional therapy (namely, aminosalicylates, antibiotics, corticosteroids and immunomodulatory agents) for prolonged periods of time, to both induce and maintain remission. Treatment paradigms in IBD have evolved towards a rapid escalation of therapy to achieve stringent goals, including mucosal healing and a reduction in the need for hospital admission and surgery. In this context, the failure to optimize conventional therapy can lead to a potentially effective treatment being abandoned too early, which is undesirable when only a limited number of drugs are effective in the management of IBD, and could also lead to patients being unnecessarily exposed to potentially toxic and/or expensive biologic drugs. This Review provides an overview of the many ways in which conventional therapy can be optimized, and describes strategies to improve adherence to drug regimens, such as simplifying the dosing regimen, optimizing drug delivery and dose, and tailoring medication on the basis of metabolite levels.

Experiences of children/young people and their parents, using insulin pump therapy for the management of type 1 diabetes: qualitative review

WHAT IS KNOWN AND OBJECTIVE

Advances in medical technology have made insulin pumps an attractive treatment option for patients with type 1 diabetes and in particular for children and young people. Previous studies have accounted the experiences and views of children/young people and their parents for the use of the injection therapy, but very few have focused on the use of insulin pumps. The objective of this review was to identify studies that explore the experiences of children/young people and their parents on the transition from injections to insulin pump therapy, in the context of their social life.

METHODS

A systematic literature search was conducted, and six studies meeting the inclusion and exclusion criteria were identified.

RESULTS

  Views and perspectives from the studies identified mainly focused on: introduction to the pump; reasons for the transition to pump therapy; advantages and disadvantages of this treatment option; and impact on quality of life (QoL). Parents and/or children reported that they learned about pump therapy either formally from a healthcare professional or informally from a friend or the internet. Many reasons were identified for the transition, the most important being the pursuit of stable and controlled blood sugar levels and the desire for a more flexible lifestyle. Participants highlighted the advantages of insulin pumps in terms of improved diabetes control. Moreover, there was a positive impact on the QoL, as insulin pumps provided children greater flexibility in lifestyles especially with regards to meals and socialization. In contrast, psychosocial issues such as pump visibility and physical restrictions were highlighted as disadvantages. Issues such as day-to-day management were also discussed.

WHAT IS NEW AND CONCLUSION

Exploring children/young people's perspectives on the use of pump therapy for managing their diabetes, and parental reflections in caring for those children is important as it provides evidence informing policy for the wider implementation of this technology in the management of diabetes in children. However, the review revealed that there is a scarcity of data in this area and that further research is needed.

Experiences of children/young people and their parents, using insulin pump therapy for the management of type 1 diabetes: qualitative review

WHAT IS KNOWN AND OBJECTIVE

Advances in medical technology have made insulin pumps an attractive treatment option for patients with type 1 diabetes and in particular for children and young people. Previous studies have accounted the experiences and views of children/young people and their parents for the use of the injection therapy, but very few have focused on the use of insulin pumps. The objective of this review was to identify studies that explore the experiences of children/young people and their parents on the transition from injections to insulin pump therapy, in the context of their social life.

METHODS

A systematic literature search was conducted, and six studies meeting the inclusion and exclusion criteria were identified.

RESULTS

  Views and perspectives from the studies identified mainly focused on: introduction to the pump; reasons for the transition to pump therapy; advantages and disadvantages of this treatment option; and impact on quality of life (QoL). Parents and/or children reported that they learned about pump therapy either formally from a healthcare professional or informally from a friend or the internet. Many reasons were identified for the transition, the most important being the pursuit of stable and controlled blood sugar levels and the desire for a more flexible lifestyle. Participants highlighted the advantages of insulin pumps in terms of improved diabetes control. Moreover, there was a positive impact on the QoL, as insulin pumps provided children greater flexibility in lifestyles especially with regards to meals and socialization. In contrast, psychosocial issues such as pump visibility and physical restrictions were highlighted as disadvantages. Issues such as day-to-day management were also discussed.

WHAT IS NEW AND CONCLUSION

Exploring children/young people's perspectives on the use of pump therapy for managing their diabetes, and parental reflections in caring for those children is important as it provides evidence informing policy for the wider implementation of this technology in the management of diabetes in children. However, the review revealed that there is a scarcity of data in this area and that further research is needed.

The inflammatory effect of cardiopulmonary bypass on leukocyte extravasation in vivo

OBJECTIVE

Extravascular trafficking of leukocytes into organs is thought to play a major role in the pathophysiologic mechanisms of the inflammatory response to cardiopulmonary bypass, yet leukocyte extravasation is difficult to study clinically. Here we have tested the hypothesis that leukocyte emigration into skin blisters can provide a way to monitor the inflammatory effect of cardiopulmonary bypass that allows testing of anti-inflammatory interventions (exemplified by aprotinin).

METHODS

Patients undergoing primary elective coronary artery bypass grafting (n = 14) were randomized into 2 equal groups to receive saline infusion during cardiopulmonary bypass (control group) or high-dose aprotinin. Experimental skin blisters (in duplicate) were induced on the forearm by means of topical application of the vesicant cantharidin, and blister fluid was sampled at 5 hours postoperatively. Inflammatory leukocyte subsets in blister fluid were analyzed by means of flow cytometry by using expression of CD11b and CD62L as a phenotypic marker of activation.

RESULTS

In the control group of patients, cardiopulmonary bypass surgery triggered a 381% increase in leukocyte extravasation into the skin compared with reference blisters carried out before surgical intervention, with neutrophil (P = .014), monocyte (P = .014), and eosinophil (P = .009) levels all statistically significantly increased. In the aprotinin group there was no statistically significant increase during cardiopulmonary bypass surgery in any inflammatory leukocyte subset. The activation phenotype of extravascular leukocytes was not significantly altered between surgical groups.

CONCLUSIONS

This study introduces the cantharidin blister technique as a powerful new research tool for analyzing the inflammatory effect of cardiopulmonary bypass in vivo. It has provided detailed molecular insight into the extravascular leukocyte population during cardiopulmonary bypass. Although aprotinin blocked cardiopulmonary bypass-dependent extravasation of leukocytes, there was no change in their CD11b/CD62L activation status. The cantharidin skin test thus represents a novel research tool for evaluating future anti-inflammatory interventions in cardiothoracic surgery.

Dual targeting of Src and ER prevents acquired antihormone resistance in breast cancer cells

Acquired resistance to endocrine therapies presents a major obstacle to the successful treatment of breast cancer patients. Previously, we have shown that acquisition of resistance to tamoxifen in breast cancer cells is accompanied by an elevation in Src kinase activity which promotes an aggressive, invasive phenotype in vitro. Here, we have explored the potential therapeutic effects of combining Src inhibition with anti-oestrogen treatment on the development of endocrine insensitivity in breast cancer cells. Treatment of MCF7 and T47D cells with tamoxifen alone resulted in an initial growth inhibitory phase followed by the eventual development of tamoxifen resistance together with an elevation of Src kinase activity, which was central to their increased invasive capacity. Chronic exposure of both cell types to the Src inhibitor, AZD0530, as a monotherapy resulted in outgrowth of AZD0530-resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasive nature. Treatment of both MCF7 and T47D cells with AZD0530 in combination with tamoxifen resulted in a reduction of Src activity together with inhibition of focal adhesion kinase phosphorylation and a complete abrogation of their in vitro invasive behaviour. Furthermore, combination therapy significantly suppressed expression of cyclinD1 and c-myc and prevented cell proliferation and the subsequent emergence of a resistant phenotype, with total cell loss occurring by 12 weeks. These data demonstrate that pharmacological targeting of Src kinase, in conjunction with antihormone therapies, effectively prevents antihormone resistance in breast cancer cells in vitro and suggests a potential novel therapeutic benefit of Src kinase inhibitors clinically.

Prospective audit of colonoscopy quality in Kent and Medway, UK

AIM

To compare the quality of colonoscopy in the Kent and Medway Strategic Health Authority with national standards and previous audits.

METHOD

A prospective 12-month audit of colonoscopy quality as assessed by number of procedures performed, total colonoscopy rates, sedation usage, and complications. Data were collected by 7 endoscopy units on 5905 colonoscopies performed by 62 colonoscopists. The endoscopy unit nurses, as opposed to the colonoscopists, verified that colonoscopy was total.

RESULTS

Seven doctors stopped performing colonoscopy during the study period. Thirty-nine of 55 colonoscopists (71 %) achieved total colonoscopy in at least 90 % of cases; 12 (22 %) completed colonoscopy in 80 - 89 % of their cases and 4 (7 %) in 79 % or less of their cases. Seventy-nine percent of colonoscopists used sedation in accordance with British Society of Gastroenterology (BSG) guidelines. Only 22 of 55 (40 %) of colonoscopists performed more than 100 colonoscopies during the 12-month audit period. Reported complications were below expected levels.

CONCLUSION

In our study almost one-third of colonoscopists did not achieve colonoscopy completion rates of at least 90%, and less than half performed more than 100 colonoscopies during the 12 month study. Adherence to quality standards appears to be inadequate.

Influence of socioeconomic status on survival after primary aortic or mitral valve replacement

OBJECTIVES

We sought to evaluate whether socioeconomic status influences outcome after first-time single aortic or mitral valve replacement.

SETTING

National Heart Valve registry.

DESIGN AND PATIENTS

Between 1 January 1986 and 31 December 2001, 51 844 consecutive patients who underwent primary aortic or mitral valve replacement were registered on the United Kingdom (UK) Heart Valve Registry. Data included age, gender, valve position, type of valve implant, postcode, follow-up time, date and cause of death. The Carstairs deprivation score (1991 Census data for the UK) was used to stratify cases by level of social deprivation according to postcodes.

RESULTS

Both 30-day and 1-year survival/mortality rates were similar across all socioeconomic levels. However, long-term survival rate (up to 15 years) was significantly higher in the least deprived socioeconomic level than in the two most deprived levels. There was an 18% lower survival rate amongst women in the most deprived levels (35.9%, 95% CI: 32.4 to 39.4) versus the least deprived level (43.7%, 95% CI: 38.1 to 49.2, p<0.004). In men, survival in the most deprived levels (39.5%, 95% CI: 36.4 to 42.5) was 7% lower than in the least deprived level (42.7%, 95% CI: 37.7 to 47.7, p<0.005). Biological valve, mitral position, female gender, and low socioeconomic status were all associated with long-term mortality.

CONCLUSIONS

A disadvantaged social background has a negative influence on long-term survival after aortic or mitral valve replacement, especially among women.

Growth factor signalling in endocrine and anti-growth factor resistant breast cancer

Growth factors provide powerful mitogenic and survival signals to breast cancer cells and it is therefore not surprising that they are able to subvert inhibitory responses to anti-hormonal drugs. In this review we discuss several mechanisms by which this may be achieved and expand our observations to encompass recently emerging anti-growth factor treatments. The information presented is underpinned by inhibitor studies that show the targeting of such mechanisms in advance of anti-hormone or anti-growth factor resistance development is able to substantially delay this event, thus pointing the way forward to intelligent combination therapies relevant to the future management of breast cancer.

Aprotinin and the protease-activated receptor 1 thrombin receptor: antithrombosis, inflammation, and stroke reduction

Cardiopulmonary bypass, although remaining an indispensable asset in cardiac surgery, especially in more complex and repeat operations, is associated with significant thrombin generation in the bypass circuit, leading to the activation of platelets, the coagulation system, an inflammatory response, and perioperative stroke. Recent clinical studies and meta-analyses of clinical trials in coronary artery bypass grafting surgery have confirmed that aprotinin not only reduces transfusion requirements in cardiac surgery but also confers significant protection against platelet dysfunction, activation of the systemic inflammatory response, and perioperative stroke when administered at the full (or "Hammersmith") dose. This article reviews research from several independent groups to propose a novel mechanism through which the antithrombotic, anti-inflammatory, and neuroprotective mechanism might be mediated, via protection of the high-affinity thrombin receptor protease-activated receptor 1 (PAR1).