Dynamic control of endogenous metabolism with combinatorial logic circuits.

Controlling gene expression during a bioprocess enables real-time metabolic control, coordinated cellular responses, and staging order-of-operations. Achieving this with small molecule inducers is impractical at scale and dynamic circuits are difficult to design. Here, we show that the same set of sensors can be integrated by different combinatorial logic circuits to vary when genes are turned on and off during growth. Three Escherichia coli sensors that respond to the consumption of feedstock (glucose), dissolved oxygen, and by-product accumulation (acetate) are constructed and optimized. By integrating these sensors, logic circuits implement temporal control over an 18-h period. The circuit outputs are used to regulate endogenous enzymes at the transcriptional and post-translational level using CRISPRi and targeted proteolysis, respectively. As a demonstration, two circuits are designed to control acetate production by matching their dynamics to when endogenous genes are expressed (pta or poxB) and respond by turning off the corresponding gene. This work demonstrates how simple circuits can be implemented to enable customizable dynamic gene regulation.

Boosting Wnt activity during colorectal cancer progression through selective hypermethylation of Wnt signaling antagonists.

BACKGROUND: There is emerging evidence that Wnt pathway activity may increase during the progression from colorectal adenoma to carcinoma and that this increase is potentially an important step towards the invasive stage. Here, we investigated whether epigenetic silencing of Wnt antagonists is the biological driver for this increased Wnt activity in human tissues and how these methylation changes correlate with MSI (Microsatelite Instability) and CIMP (CpG Island Methylator Phenotype) statuses as well as known mutations in genes driving colorectal neoplasia. METHODS: We conducted a systematic analysis by pyrosequencing, to determine the promoter methylation of CpG islands associated with 17 Wnt signaling component genes. Methylation levels were correlated with MSI and CIMP statuses and known mutations within the APC, BRAF and KRAS genes in 264 matched samples representing the progression from normal to pre-invasive adenoma to colorectal carcinoma. RESULTS: We discovered widespread hypermethylation of the Wnt antagonists SFRP1, SFRP2, SFRP5, DKK2, WIF1 and SOX17 in the transition from normal to adenoma with only the Wnt antagonists SFRP1, SFRP2, DKK2 and WIF1 showing further significant increase in methylation from adenoma to carcinoma. We show this to be accompanied by loss of expression of these Wnt antagonists, and by an increase in nuclear Wnt pathway activity. Mixed effects models revealed that mutations in APC, BRAF and KRAS occur at the transition from normal to adenoma stages whilst the hypermethylation of the Wnt antagonists continued to accumulate during the transitions from adenoma to carcinoma stages. CONCLUSION: Our study provides strong evidence for a correlation between progressive hypermethylation and silencing of several Wnt antagonists with stepping-up in Wnt pathway activity beyond the APC loss associated tumour-initiating Wnt signalling levels.

Safety of the colonoscope magnetic imaging device (ScopeGuide) in patients with implantable cardiac devices.

BACKGROUND AND STUDY AIMS: Use of the colonoscope magnetic imaging device (ScopeGuide, Olympus Medical Systems, Tokyo, Japan) is currently contraindicated by the manufacturer for patients with implantable cardiac devices, a group of patients that is increasing annually along with the number of colonoscopies performed in the era of colorectal cancer screening. This is the first study to examine the safety of ScopeGuide in patients with permanent pacemakers, implantable cardioverter defibrillators, and cardiac resynchronization therapy. PATIENTS AND METHODS: Nonimplanted cardiac devices were exposed to the electromagnetic field of ScopeGuide ex vivo and assessed for evidence of interference or change in device settings. Following this, consecutive patients attending device check clinics were prospectively recruited and exposed to the ScopeGuide electromagnetic field. After an initial device check, patients underwent continuous external cardiac monitoring and device interrogation while a colonoscope was placed on the abdomen over clothing and connected to ScopeGuide to simulate colonoscopy. Patients were monitored for 2 minutes to assess for any interference. ScopeGuide was then disconnected and devices were checked for any change in settings. RESULTS: A total of 230 patients were invited to participate and 100 were recruited to the study. There was no evidence of interference on device leads or change in programming following exposure to the electromagnetic field generated by ScopeGuide. CONCLUSION: ScopeGuide does not appear to cause interference or change in settings and is therefore likely to be safe for use in patients with implantable cardiac devices.

Moving from non-emergency bleeps and long-range pagers to a hospital-wide, EHR-integrated secure messaging system: an implementer report.

INTRODUCTION: Obsolete bleep/long-range pager equipment remains firmly embedded in the National Health Service (NHS). OBJECTIVE: To introduce a secure, chart-integrated messaging system (Epic Secure Chat) in a large NHS tertiary referral centre to replace non-emergency bleeps/long-range pagers. METHODS: The system was socialised in the months before go-live. Operational readiness was overseen by an implementation group with stakeholder engagement. Cutover was accompanied by a week of Secure Chat and bleeps running in parallel. RESULTS: Engagement due to socialisation was high with usage stabilising approximately 3 months after go-live. Contact centre internal call activity fell significantly after go-live. No significant patient safety concerns were reported. DISCUSSION: Uptake was excellent with substantial utilisation well before cutover indirectly supporting high levels of engagement. The majority of those who previously carried bleeps were content to use personal devices for messaging because of user convenience after reassurance about privacy. CONCLUSION: An integrated secure messaging system can replace non-emergency bleeps with beneficial impact on service.

Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening.

BACKGROUND AND OBJECTIVES: The UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests. In this multisite, prospective, randomised controlled trial, we aimed to compare the performance of Standard Definition Olympus Lucera (SD-OL) with Scope Guide and the High Definition Pentax HiLine (HD-PHL). PATIENTS AND METHODS: Subjects undergoing a colonoscopy as part of the UK National BCSP at four UK sites were randomised to an endoscopy list run using either SD-OL or HD-PHL. Primary endpoints were polyp and adenoma detection rate (PDR and ADR, respectively) as well as polyp size, morphology and histology characteristics. RESULTS: 262 subjects (168 males, mean age 66.3±4.3 years) were colonoscoped (133 patients with HD-PHL while 129 with SD-OL). PDR and ADR were comparable within the two optical systems. The HD-PHL group resulted in a PDR 55.6% and ADR 43.6%; the SD-OL group had PDR 56.6% and ADR 45.7%. HD-PHL was significantly superior to SD-OL in detection of flat adenomas (18.6% vs 5.2%, p<0.001), but not detection of pedunculated or sessile polyps. Patient comfort, use of sedation and endoscopist perception of procedural difficulty resulted similar despite the use of Scope Guide with SD-OL. CONCLUSION: PDR and ADR were not significantly different between devices. The high-resolution colonoscopy system HD-PHL may improve polyp detection as compared with standard resolution technology in detecting flat adenomas. This advantage may have clinically significant implications for missed lesion rates and post-colonoscopy interval colorectal cancer rates.

Activation of Akt is increased in the dysplasia-carcinoma sequence in Barrett's oesophagus and contributes to increased proliferation and inhibition of apoptosis: a histopathological and functional study.

BACKGROUND: The incidence of oesophageal adenocarcinoma is increasing rapidly in the developed world. The serine-threonine protein kinase and proto-oncogene Akt has been reported to regulate proliferation and apoptosis in several tissues but there are no data on the involvement of Akt in oesophageal carcinogenesis. Therefore we have examined the activation of Akt in Barrett's oesophagus and oesophageal adenocarcinoma and the functional effects of Akt activation in vitro. METHODS: Expression of total and active (phosphorylated) Akt were determined in endoscopic biopsies and surgical resection specimens using immunohistochemistry. The functional effects of Akt were examined using Barrett's adenocarcinoma cells in culture. RESULTS: In normal squamous oesophagus, erosive oesophagitis and non-dysplastic Barrett's oesophagus, phospho-Akt was limited to the basal 1/3 of the mucosa. Image analysis confirmed that Akt activation was significantly increased in non-dysplastic Barrett's oesophagus compared to squamous epithelium and further significantly increased in high-grade dysplasia and adenocarcinoma. In all cases of high grade dysplasia and adenocarcinoma Akt was activated in the luminal 1/3 of the epithelium. Transient acid exposure and the obesity hormone leptin activated Akt, stimulated proliferation and inhibited apoptosis: the combination of acid and leptin was synergistic. Inhibition of Akt phosphorylation with LY294002 increased apoptosis and blocked the effects of acid and leptin both alone and in combination. Activation of Akt was associated with downstream phosphorylation and deactivation of the pro-apoptotic protein Bad and phosphorylation of the Forkhead family transcription factor FOXO1. CONCLUSION: Akt is abnormally activated in Barrett's oesophagus, high grade dysplasia and adenocarcinoma. Akt activation promotes proliferation and inhibits apoptosis in Barrett's adenocarcinoma cells and both transient acid exposure and leptin stimulate Akt phosphorylation. Downstream targets of Akt include Bad and Forkhead transcription factors. Activation of Akt in obesity and by reflux of gastric acid may be important in the pathogenesis of Barrett's adenocarcinoma.

The Association of Geriatric Syndromes with Hospital Outcomes.

BACKGROUND: Frailty, history of dementia (HoD), and acute confusional states (ACS) are common in older patients admitted to hospital. OBJECTIVE: To study the association of frailty (≥6 points in the Clinical Frailty Scale [CFS]), HoD, and ACS with hospital outcomes, controlling for age, gender, acute illness severity (measured by a Modified Early Warning Score in the emergency department), comorbidity (Charlson Comorbidity Index), and discharging specialty (general medicine, geriatric medicine, surgery). DESIGN: Retrospective observational study. SETTING: Large university hospital in England. PATIENTS: We analyzed 8202 first nonelective inpatient episodes of people aged 75 years and older between October 2014 and October 2015. MEASUREMENTS: The outcomes studied were prolonged length of stay (LOS ≥10 days), inpatient mortality, delayed discharge, institutionalization, and 30-day readmission. Statistical analyses were based on multivariate regression models. RESULTS: Independently of controlling variables, prolonged LOS was predicted by CFS ≥6: odds ratio (OR) =1.55; 95% confidence interval [CI], 1.36-1.77; P ⟨ 0.001; HoD: OR = 2.16; 95% CI, 1.79-2.61; P ⟨ 0.001; and ACS: OR = 3.31; 95% CI, 2.64-4.15; P ⟨ 0.001. Inpatient mortality was predicted by CFS ≥6: OR = 2.29; 95% CI, 1.79-2.94; P ⟨ 0.001. Delayed discharge was predicted by CFS ≥6: OR = 1.46; 95% CI, 1.27-1.67; P ⟨ 0.001; HoD: OR = 2.17; 95% CI, 1.80-2.62; P ⟨ 0.001; and ACS: OR = 2.29; 95% CI: 1.83-2.85; P ⟨ 0.001. Institutionalization was predicted by CFS ≥6: OR = 2.56; 95% CI, 2.09-3.14; P ⟨ 0.001; HoD: OR = 2.51; 95% CI, 2.00-3.14; P ⟨ 0.001; and ACS: OR 1.93; 95% CI, 1.46-2.56; P ⟨ 0.001. Readmission was predicted by ACS: OR = 1.36; 95% CI, 1.09-1.71; P = 0.006. CONCLUSIONS: Routine screening for frailty, HoD, and ACS in hospitals may aid the development of acute care pathways for older adults. Journal of Hospital Medicine 2017;12:83-89.

The relationship between prevalence of active trachoma, water availability and its use in a Tanzanian village.

This study aimed to establish the relationship between the prevalence of active trachoma in children, water availability and household water use in a village in Tanzania. Nine hundred and fourteen children aged 1-9 years were examined for signs of trachoma. Data were collected on time taken to collect water, amount of water collected and other trachoma risk factors. In a sub-study, 99 randomly selected households were visited twice daily on two consecutive days to document patterns of water use. The prevalence of active trachoma in the children examined was 18.4% (95% CI 15.9-20.9). Active trachoma prevalence increased with increasing water collection time (OR 2.25; 95% CI 1.13-4.46) but was unrelated to the amount of water collected. In the sub-study, active trachoma prevalence was substantially lower in children from households where more water was used for personal hygiene (P for trend < or =0.01), independent of the total amount of water used. The allocation of water to hygiene was predicted by lower water collection time. The key element in the relationship between water availability and trachoma is the allocation of water within households. Collection time may influence both the quantity of water collected and its allocation within the household.

The McKittrick-Wheelock syndrome: a rare cause of curable diabetes.

UNLABELLED: McKittrick-Wheelock syndrome (MWS) is a rare consequence of severe dehydration and electrolyte depletion due to mucinous diarrhoea secondary to a rectosigmoid villous adenoma. Reported cases of MWS commonly describe hypersecretion of mucinous diarrhoea in association with dehydration, hypokalaemia, hyponatraemia, hypochloraemia and pre-renal azotemia. Hyperglycaemia and diabetes are rarely reported manifestations of MWS. Herein we describe the case of a 59-year-old woman who presented with new-onset diabetes and severe electrolyte derangement due to a giant rectal villous adenoma. Subsequent endoscopic resection of the tumour cured her diabetes and normalised electrolytes. This case describes a rare cause of 'curable diabetes' and indicates hyperaldosteronism and/or whole-body potassium stores as important regulators of insulin secretion and glucose homeostasis. LEARNING POINTS: McKittrick-Wheelock syndrome (MWS) is typically characterised by the triad of pre-renal failure, electrolyte derangement and chronic diarrhoea resulting from a secretory colonic neoplasm.Hyperglycaemia and new-onset diabetes are rare clinical manifestations of MWS.Hyperaldosteronism and/or hypokalaemia may worsen glucose tolerance in MWS.Aggressive replacement of fluid and electrolytes is the mainstay of acute management, with definitive treatment and complete reversal of the metabolic abnormalities being achieved by endoscopic or surgical resection of the neoplasm.

Helicobacter pylori: antibiotic resistance and eradication rates in Suffolk, UK, 1991-2001.

Helicobacter pylori infection causes a number of gastrointestinal diseases and its current treatment is based on multidrug regimes including acid suppression and antimicrobials. The success of these regimes is determined by a number of factors including antibiotic resistance, which varies widely but is an increasing problem. Local data are important in establishing the most cost-effective eradication regime. Data have been collected prospectively on antibiotic resistance at Ipswich Hospital (Suffolk, UK) in all consecutive isolates of H. pylori from 1991 to 2001. The success of regimes consisting of a proton pump inhibitor, amoxycillin and metronidazole (PPI/A/M) has also been evaluated in patients found positive on serological testing in primary care using urea breath testing. Overall, metronidazole resistance was found in 31.7 % of isolates and clarithromycin resistance in 5.3 %. A significant increase in metronidazole resistance from 29.1 to 37.0 % (P = 0.022) and a decrease in clarithromycin resistance from 10.3 to 3.8 % (P = 0.014) was seen over the study period. Metronidazole resistance was significantly more common in women (P < 0.001) and young patients (P < 0.001). Eradication with PPI/A/M was successful in 89.9 % of patients and did not change significantly over the study period. Eradication rates were lower in young patients (P < 0.001). Whilst metronidazole resistance is increasing in Suffolk, this does not seem to have a significant effect on eradication rates. Metronidazole-based regimes are still effective first-line treatments in most patients.

Three-year prospective validation of a pre-endoscopic risk stratification in patients with acute upper-gastrointestinal haemorrhage.

OBJECTIVE: To assess the accuracy of a risk stratification that is used at initial assessment to identify groups with increased risk of mortality and requirement for urgent treatment intervention. DESIGN: Prospective assessment of risk stratification in consecutive patients with acute upper-gastrointestinal haemorrhage. METHODS: Over a 3-year period, 1349 consecutive patients with acute upper-gastrointestinal haemorrhage presenting to a single teaching hospital were prospectively risk stratified before endoscopy and followed up for outcome. MAIN OUTCOME MEASURES: Two-week, all-cause mortality, re-bleeding, and need for urgent treatment intervention. RESULTS: Stratification within the high-risk group predicted a significant increased risk of 2-week, all-cause mortality (P < 0.001) when compared with intermediate- and low-risk patients (11.8%, 3% and 0%, respectively), re-bleeding (P < 0.001) (44.1%, 2.3% and 0%, respectively), and need for urgent treatment intervention (P < 0.001) (71%, 40.6% and 2.6%, respectively). CONCLUSIONS: Over a 3-year period, medical staff at this institution have routinely used this risk stratification, which identifies groups of patients at high and low risk of mortality, re-bleeding and need for urgent treatment intervention following acute upper-gastrointestinal haemorrhage. Use of this risk stratification should allow targeting of more intensive treatment where it might be of most benefit. Those patients at lowest risk from outpatient management are also identified.

Oral gel choline salicylate induced refractory gastric ulceration.

Common over the counter oral ulcer soothing gel can be an unexpected source of salicylate and cause refractory gastrointestinal ulcers if not identified.

A comparison of outcomes for adults and children undergoing resection for inflammatory bowel disease: is there a difference?

Background. The incidence of inflammatory bowel disease (IBD) is increasing in the paediatric population. Since 2007, a single surgeon whose main practice is in the treatment of adults has performed surgery for IBD in adults and children within two dedicated multidisciplinary teams. Our aim was to assess and compare outcomes for adults and children following surgery for IBD. Methods. Analysis of a prospectively collected database was carried out to include all patients who had undergone resectional surgery for IBD between 2007 and 2012. Results. 48 adults and 30 children were included in the study. Median age for children was 14 years (range 8-16) and for adults was 33.5 years (range 17-64). Median BMI was 23 (range 18-38) and 19 (range 13-29.5) in adults and children, respectively (P < 0.001). Laparoscopic resection was performed in 27 (90%) children and 36 (75%) adults. Postoperative complication rates were comparable, 11 (23%) in adults versus 6 (20%) in children (P = 1.00). Conclusion. Resectional surgery for IBD in children has outcomes that compare favourably with the adult population, with the majority of cases being performed by a laparoscopic approach.

Sir James Young Simpson and religion: myths and controversies.

This paper analyses two key aspects of the life and work of Sir James Young Simpson: his evangelical Christianity and his reaction to criticism following his use of anaesthesia in obstetrics. Simpson's personal religious struggle is placed in the context of the devastating events surrounding the Disruption of the established Church of Scotland in 1843. Whatever his involvement in the events of that year, the development of his faith demonstrates his simple evangelical conviction in the atonement of Christ, very much in keeping with that of many believers in Victorian Britain. There has arisen the notion (still current as is clear from publications in medical journals within recent years) that there was a savage religious response, especially in Presbyterian Scotland, to his use of chloroform - in reality the attack on Simpson's enthusiastic promotion of chloroform was brief, sporadic and of little moment. Simpson's carefully constructed counter to criticism of anaesthesia, drawing on considerable theological and linguistic expertise, reveals a complexity at odds with the simplicity of his faith. The contrast is so great and the reaction so elaborate that it is proposed that Simpson deliberately exaggerated the affair, believing the publicity could only be valuable.

Comparison of Pentax HiLine and Olympus Lucera systems at screening colonoscopy.

AIM: To compare the performance characteristics of Pentax HiLine (PHL) (with i-scan) and Olympus Lucera (OL) systems in a screening population. METHODS: Screening colonoscopies in asymptomatic guaiac faecal occult blood test-positive patients with PHL (n = 58) and OL (n = 425) colonoscopes were analysed. All procedures were performed by a single colonoscopist. PHL used white-light endoscopy (WLE) on scope insertion and contrast/surface enhancement (i-scan 1) on withdrawal, and OL utilised WLE both on insertion and withdrawal. Patient age, sex, instrument insertion and withdrawal times, nurse assessed patient comfort scores, midazolam and fentanyl doses, procedure completion and rates of lesion detection were recorded separately for each group. Comparisons between the groups were made using either Fisher's exact test (for dichotomous variables) or Mann-Whitney U test (for ordinal and continuous variables). RESULTS: Colonoscopy completion rates were similar in both groups: 413/425 (97.2%) for OL and 55/58 (94.9%) for PHL (P = 0.24). For complete colonoscopies, the two groups were well matched for age, sex, colonoscope insertion times (mean 11.1 min in OL vs 11.6 min in PHL, P = 0.93) and normal colonoscopy withdrawal times (mean 15.6 min in OL vs 14.7 min in PHL, P = 0.2). Patients in the PHL group experienced a small increase in discomfort (mean patient comfort scores were 0.49 in the OL and 0.95 in the PHL group, P < 0.0001). While Fentanyl doses required were similar between groups (mean 57.5 µg in OL vs 61.4 µg in PHL, P = 0.13), slightly more Midazolam was required in the PHL group (mean 2.1 mg in OL vs 2.4 mg in PHL, P = 0.035). There was no difference in polyp (58% in OL vs 67% in PHL) or adenoma (49% in OL vs 56% in PHL) detection rates between the groups. Neither the total number of polyps and adenomas, nor the characteristics of these (including size, location or presence of advanced features) were different between the two systems. CONCLUSION: This study suggests that there is no advantage of either colonoscope system in lesion detection.

The frequency of Chlamydia trachomatis major outer membrane protein-specific CD8+ T lymphocytes in active trachoma is associated with current ocular infection.

Chlamydia-specific cytotoxic T lymphocytes are able to control model infections but may be implicated in disease pathogenesis. HLA-A2 peptide tetramers to Chlamydia trachomatis major outer membrane protein 258-266 (MOMP258-266) and MOMP260-268 were used to characterize HLA class I-restricted CD8+ T cells in Gambian children aged 4 to 15 years with clinical signs of active trachoma and/or infection with C. trachomatis. The frequencies of circulating HLA-A2 tetramer binding cells (TBC) were determined in whole blood samples by flow cytometric analysis. Initial screening of subjects with an anti-HLA-A2 antibody confirmed the presence of either HLA-A2 or HLA-A28. These were subsequently further divided by molecular subtyping. The C. trachomatis-specific HLA-A2 peptide tetramers were able to bind T cells with receptors from subjects which were restricted by either the HLA-A2 or the HLA-A28 restriction element. In this population, the median value of C. trachomatis-specific CD8+ T cells was 0.02%, with frequencies of up to 3.71% of CD8+ T cells reactive with a single tetramer in a minority of subjects. TBC were detected more often in subjects who were infected at the ocular surface, and their presence was associated with infection episodes of longer duration. Detection of C. trachomatis-specific TBC was not associated with the presence of disease or with the estimated load of ocular C. trachomatis infection at the time of sample collection. High frequencies of C. trachomatis-specific cells did not predict subsequent appearance or resolution of the clinical disease signs of active trachoma.