Validation of the ACE [Albumin, CRP, and Endoscopy] Index in Acute Colitis: Analysis of the CONSTRUCT dataset

BACKGROUND AND AIMS

In 2020 we reported the ACE Index in acute colitis which used biochemical and endoscopic parameters to predict steroid non-response on admission in patients with acute ulcerative colitis [UC]. We aimed to validate the ACE Index in an independent cohort.

METHODS

The validation cohort comprised patients screened as eligible for inclusion in the CONSTRUCT study, a prospective, randomized, placebo-controlled trial which compared the effectiveness of treatment with infliximab vs ciclosporin in patients admitted with acute UC. The CONSTRUCT cohort database was reviewed at The Edinburgh IBD Unit and the same biochemical and endoscopic variables and cut-off values as those in the derivation cohort were applied to the validation cohort.

RESULTS

In total, 800 patients were identified; 62.5% [55/88] of patients with a maximum ACE Index of 3 did not respond to intravenous [IV] steroids (positive predictive value [PPV] 62.5%, negative predictive value [NPV] 79.8%). Furthermore, 79.8% [158/198] of patients with an ACE Index of 0 responded to IV steroids [PPV 79.8%, NPV 62.5%]. Receiver operator characteristic [ROC] curve analysis produced an area under the curve [AUC] of 0.663 [p < 0.001].

CONCLUSIONS

We have now reported and externally validated the ACE Index in acute colitis in a combined cohort of over 1000 patients from across the UK. The ACE Index may be used in conjunction with clinical judgement to help identify patients admitted with active UC who are at high risk of not responding to IV steroids. Further studies are required to improve objectivity and accuracy of assessment.

Real-World Cohort Study on the Effectiveness and Safety of Filgotinib Use in Ulcerative Colitis

BACKGROUND

Filgotinib is a small molecule with preferential inhibition of Janus kinase type 1, approved for the treatment of ulcerative colitis in Scotland in May 2022. We present the first real world experience on its use in clinical practice.

METHODS

In this retrospective, observational, cohort study we assessed patients with active ulcerative colitis who received filgotinib in NHS Lothian, Scotland. Baseline demographic, phenotype and follow-up data were collected via review of electronic medical records.

RESULTS

We included 91 patients with median treatment duration of 39 weeks (IQR 23-49). Among the cohort, 67% (61/91) were biologic and small molecule naïve, whilst 20.9% (19/91) had failed one and 12.1% (11/91) ≥2 classes of advanced therapy. Of the biologic and small molecule naïve patients, 18% (11/61) were also thiopurine naïve. Clinical remission (partial Mayo score <2) was achieved in 71.9% (41/57) and 76.4% (42/55) of patients at weeks 12 and 24 respectively. Biochemical remission (CRP≤5mg/L) was achieved in 87.3% (62/71) at week 12 and 88.9% (40/45) at week 24. Faecal biomarker (calprotectin <250µg/g) remission was achieved in 82.8% (48/58) at week 12 and 79.5% (35/44) at week 24.At the end of follow-up, median 42 weeks (IQR 27-50), 82.4% (75/91) of patients remained on filgotinib. Severe adverse events leading to drug discontinuation occurred in 2.2% (2/91) and there were 8.8% (8/91) moderate adverse events that required temporary discontinuation.

CONCLUSION

These are the first reported data on the real-world efficacy and safety of filgotinib in ulcerative colitis. Our findings demonstrate that filgotinib is an effective and low risk treatment option for these patients.

CSF1R-dependent macrophages in the salivary gland are essential for epithelial regeneration after radiation-induced injury

The salivary glands often become damaged in individuals receiving radiotherapy for head and neck cancer, resulting in chronic dry mouth. This leads to detrimental effects on their health and quality of life, for which there is no regenerative therapy. Macrophages are the predominant immune cell in the salivary glands and are attractive therapeutic targets due to their unrivaled capacity to drive tissue repair. Yet, the nature and role of macrophages in salivary gland homeostasis and how they may contribute to tissue repair after injury are not well understood. Here, we show that at least two phenotypically and transcriptionally distinct CX3CR1+ macrophage populations are present in the adult salivary gland, which occupy anatomically distinct niches. CD11c+CD206-CD163- macrophages typically associate with gland epithelium, whereas CD11c-CD206+CD163+ macrophages associate with blood vessels and nerves. Using a suite of complementary fate mapping systems, we show that there are highly dynamic changes in the ontogeny and composition of salivary gland macrophages with age. Using an in vivo model of radiation-induced salivary gland injury combined with genetic or antibody-mediated depletion of macrophages, we demonstrate an essential role for macrophages in clearance of cells with DNA damage. Furthermore, we show that epithelial-associated macrophages are indispensable for effective tissue repair and gland function after radiation-induced injury, with their depletion resulting in reduced saliva production. Our data, therefore, provide a strong case for exploring the therapeutic potential of manipulating macrophages to promote tissue repair and thus minimize salivary gland dysfunction after radiotherapy.

Longitudinal Fecal Calprotectin Profiles Characterize Disease Course Heterogeneity in Crohn's Disease

BACKGROUND AND AIMS

The progressive nature of Crohn's disease is highly variable and hard to predict. In addition, symptoms correlate poorly with mucosal inflammation. There is therefore an urgent need to better characterize the heterogeneity of disease trajectories in Crohn's disease by utilizing objective markers of inflammation. We aimed to better understand this heterogeneity by clustering Crohn's disease patients with similar longitudinal fecal calprotectin profiles.

METHODS

We performed a retrospective cohort study at the Edinburgh IBD Unit, a tertiary referral center, and used latent class mixed models to cluster Crohn's disease subjects using fecal calprotectin observed within 5 years of diagnosis. Information criteria, alluvial plots, and cluster trajectories were used to decide the optimal number of clusters. Chi-square test, Fisher's exact test, and analysis of variance were used to test for associations with variables commonly assessed at diagnosis.

RESULTS

Our study cohort comprised 356 patients with newly diagnosed Crohn's disease and 2856 fecal calprotectin measurements taken within 5 years of diagnosis (median 7 per subject). Four distinct clusters were identified by characteristic calprotectin profiles: a cluster with consistently high fecal calprotectin and 3 clusters characterized by different downward longitudinal trends. Cluster membership was significantly associated with smoking (P = .015), upper gastrointestinal involvement (P < .001), and early biologic therapy (P < .001).

CONCLUSIONS

Our analysis demonstrates a novel approach to characterizing the heterogeneity of Crohn's disease by using fecal calprotectin. The group profiles do not simply reflect different treatment regimens and do not mirror classical disease progression endpoints.

Rates, predictive factors and effectiveness of ustekinumab intensification to 4- or 6-weekly intervals in Crohn's disease

BACKGROUND

The UNITI trial reports efficacy of ustekinumab (UST) dose intensification in Crohn's disease (CD) from 12- to 8-weekly, but not 4-weekly. We aimed 1) to assess the cumulative incidence of UST dose intensification to 4- or 6-weekly, 2) to identify factors associated with dose intensification, and 3) to assess the effectiveness of this strategy.

METHODS

We performed a retrospective, observational cohort study in NHS Lothian including all UST treated CD patients (2015-2020).

RESULTS

163 CD patients were treated with UST (median follow-up: 20.3 months [13.4-38.4]), of whom 55 (33.7%) underwent dose intensification to 4-weekly (n = 50, 30.7%) or 6-weekly (n = 5, 3.1%). After 1 year 29.9% were dose intensified. Prior exposure to both anti-TNF and vedolizumab (HR 9.5; 1.3-70.9), and concomitant steroid use at UST start (HR 1.8; 1.0-3.1) were associated with dose intensification. Following dose intensification, 62.6% patients (29/55) remained on UST beyond 1 year. Corticosteroid-free clinical remission was achieved in 27% at week 16 and 29.6% at last follow-up.

CONCLUSION

One third of CD patients treated with UST underwent dose intensification to a 4- or 6-weekly interval within the first year. Patients who failed both anti-TNF and vedolizumab, or required steroids at initiation were more likely to dose intensify.

Macrophages in intestinal homeostasis and inflammatory bowel disease

Macrophages are essential for the maintenance of intestinal homeostasis, yet appear to be drivers of inflammation in the context of inflammatory bowel disease (IBD). How these peacekeepers become powerful aggressors in IBD is still unclear, but technological advances have revolutionized our understanding of many facets of their biology. In this Review, we discuss the progress made in understanding the heterogeneity of intestinal macrophages, the functions they perform in gut health and how the environment and origin can control the differentiation and longevity of these cells. We describe how these processes might change in the context of chronic inflammation and how aberrant macrophage behaviour contributes to IBD pathology, and discuss how therapeutic approaches might target dysregulated macrophages to dampen inflammation and promote mucosal healing. Finally, we set out key areas in the field of intestinal macrophage biology for which further investigation is warranted.

Multiple infliximab biosimilar switches appear to be safe and effective in a real-world inflammatory bowel disease cohort

BACKGROUND

Switching from originator infliximab (IFX) to biosimilar IFX is effective and safe. However, data on multiple switching are scarce. The Edinburgh inflammatory bowel disease (IBD) unit has undertaken three switch programmes: (1) Remicade to CT-P13 (2016), (2) CT-P13 to SB2 (2020), and (3) SB2 to CT-P13 (2021).

OBJECTIVE

The primary endpoint of this study was to assess CT-P13 persistence following switch from SB2. Secondary endpoints included persistence stratified by the number of biosimilar switches (single, double and triple), effectiveness and safety.

METHODS

We performed a prospective, observational, cohort study. All adult IBD patients on IFX biosimilar SB2 underwent an elective switch to CT-P13. Patients were reviewed in a virtual biologic clinic with protocol driven collection of clinical disease activity, C-reactive protein (CRP), faecal calprotectin (FC), IFX trough/antibody levels, and drug survival.

RESULTS

297 patients (CD n = 196 [66%], ulcerative colitis/inflammatory bowel disease unclassified n = 101, [34%]) were switched (followed-up: 7.5 months [6.8-8.1]). This was the third, second and first IFX switch for 67/297 (22.5%), 138/297 (46.5%) and 92/297 (31%) of the cohort respectively. 90.6% of patients remained on IFX during follow-up. The number of switches was not independently associated with IFX persistence after adjusting for confounders. Clinical (p = 0.77), biochemical (CRP ≤5 mg/ml; p = 0.75) and faecal biomarker (FC<250 µg/g; p = 0.63) remission were comparable at baseline, week 12 and week 24.

CONCLUSION

Multiple successive switches from IFX originator to biosimilars are effective and safe in patients with IBD, irrespective of the number of IFX switches.

Antibody decay, T cell immunity and breakthrough infections following two SARS-CoV-2 vaccine doses in inflammatory bowel disease patients treated with infliximab and vedolizumab

Anti tumour necrosis factor (anti-TNF) drugs increase the risk of serious respiratory infection and impair protective immunity following pneumococcal and influenza vaccination. Here we report SARS-CoV-2 vaccine-induced immune responses and breakthrough infections in patients with inflammatory bowel disease, who are treated either with the anti-TNF antibody, infliximab, or with vedolizumab targeting a gut-specific anti-integrin that does not impair systemic immunity. Geometric mean [SD] anti-S RBD antibody concentrations are lower and half-lives shorter in patients treated with infliximab than vedolizumab, following two doses of BNT162b2 (566.7 U/mL [6.2] vs 4555.3 U/mL [5.4], p <0.0001; 26.8 days [95% CI 26.2 - 27.5] vs 47.6 days [45.5 - 49.8], p <0.0001); similar results are also observed with ChAdOx1 nCoV-19 vaccination (184.7 U/mL [5.0] vs 784.0 U/mL [3.5], p <0.0001; 35.9 days [34.9 - 36.8] vs 58.0 days [55.0 - 61.3], p value < 0.0001). One fifth of patients fail to mount a T cell response in both treatment groups. Breakthrough SARS-CoV-2 infections are more frequent (5.8% (201/3441) vs 3.9% (66/1682), p = 0.0039) in patients treated with infliximab than vedolizumab, and the risk of breakthrough SARS-CoV-2 infection is predicted by peak anti-S RBD antibody concentration after two vaccine doses. Irrespective of the treatments, higher, more sustained antibody levels are observed in patients with a history of SARS-CoV-2 infection prior to vaccination. Our results thus suggest that adapted vaccination schedules may be required to induce immunity in at-risk, anti-TNF-treated patients.

Real-world experience with tofacitinib in ulcerative colitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Tofacitinib is a Janus kinase inhibitor (JAKi) recently approved for the treatment of moderate to severe ulcerative colitis (UC) based on robust efficacy and safety data derived from OCTAVE clinical trials. Evidence on the outcomes of tofacitinib therapy in real-world UC patients is needed, as a number of these patients would be deemed ineligible for clinical trials. We have therefore summarised data derived from observational, real-world evidence (RWE) studies on the effectiveness and safety of tofacitinib in moderate to severe UC patients.

METHODS

We searched the PubMed, EMBASE, Scopus, Web of Science and Cochrane databases for observational studies on the use of tofacitinib in UC patients, published between 30 May 2018 and 24 January 2021. Pooled induction (8-14 weeks) and maintenance (16-26 weeks) clinical response and remission rates were calculated, as well as the proportion of reported adverse events using random effects models.

RESULTS

Nine studies were included, comprising 830 patients, of which 81% were previously treated with anti-tumour necrosis factor (TNF) and 57% with vedolizumab. Induction of clinical response and remission were achieved in 51% (95% confidence interval, 41-60%) and 37% (26-45%) of patients, after a median follow-up of 8 weeks. At the end of a median follow-up of 24 weeks, maintenance of clinical response and remission were met in 40% (31-50%) and 29% (23-36%) of patients, respectively. Thirty-two percent of the patients had at least one adverse event, the most commonly reported being mild infection (13%) and worsening of UC, requiring colectomy (13%). A third of the patients (35%) discontinued tofacitinib, most frequently due to primary non-response (51%).

CONCLUSION

Tofacitinib is a safe and effective therapy in real-world UC patients, as previously reported by clinical trials.

The transcription factor EGR2 is indispensable for tissue-specific imprinting of alveolar macrophages in health and tissue repair

Alveolar macrophages are the most abundant macrophages in the healthy lung where they play key roles in homeostasis and immune surveillance against airborne pathogens. Tissue-specific differentiation and survival of alveolar macrophages rely on niche-derived factors, such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor–β (TGF-β). However, the nature of the downstream molecular pathways that regulate the identity and function of alveolar macrophages and their response to injury remain poorly understood. Here, we identify that the transcription factor EGR2 is an evolutionarily conserved feature of lung alveolar macrophages and show that cell-intrinsic EGR2 is indispensable for the tissue-specific identity of alveolar macrophages. Mechanistically, we show that EGR2 is driven by TGF-β and GM-CSF in a PPAR-γ–dependent manner to control alveolar macrophage differentiation. Functionally, EGR2 was dispensable for the regulation of lipids in the airways but crucial for the effective handling of the respiratory pathogen Streptococcus pneumoniae. Last, we show that EGR2 is required for repopulation of the alveolar niche after sterile, bleomycin-induced lung injury and demonstrate that EGR2-dependent, monocyte-derived alveolar macrophages are vital for effective tissue repair after injury. Collectively, we demonstrate that EGR2 is an indispensable component of the transcriptional network controlling the identity and function of alveolar macrophages in health and disease.

Normalization of Fecal Calprotectin Within 12 Months of Diagnosis Is Associated With Reduced Risk of Disease Progression in Patients With Crohn's Disease

BACKGROUND & AIMS

The level of fecal calprotectin (FC) correlates with endoscopic evidence of inflammation in Crohn's disease (CD). A treat-to-target algorithm for patients with CD, that incorporates FC, outperforms a treatment strategy based on symptoms alone in the induction of mucosal healing at 12 months. We investigated whether normalization of FC within 12 months of diagnosis of CD is associated with a reduction in disease progression.

METHODS

We performed a retrospective cohort study at a tertiary IBD centre in the United Kingdom. We identified all incident cases of CD diagnosed from 2005 through 2017. Patients with a FC measurement ≥250 μg/g at diagnosis who also had at least 1 follow-up FC measurement within the first 12 months of diagnosis and >12 months of follow up were included. The last FC measurement within 12 months of diagnosis was used to determine normalization (cut-off <250 μg/g). The primary endpoint was time to first disease progression (composite of progression in Montreal disease behavior B1 to B2/3, B2 to B3, or new perianal disease; CD-related surgery; or CD-related hospitalization). Cox proportional hazards regression analysis was used to determine independent factors associated with time to first disease progression.

RESULTS

A total of 375 patients out of 1389 incident cases were included, with a median follow up of 5.3 years (interquartile range, 3.1-7.4 years). Normalization of FC within 12 months of diagnosis was confirmed in 43.5% of patients. Patients with normalized levels of FC had a significantly lower risk of composite disease progression (hazard ratio [HR], 0.36; 95% CI, 0.24-0.53; P < .001). They also had a lower risk of reaching any of the separate progression endpoints (progression in Montreal behavior or new perianal disease HR, 0.22; 95% CI, 0.11-0.45; P < .001; hospitalization HR, 0.33; 95% CI, 0.21-0.53; P <.001; surgery HR, 0.39; 95% CI, 0.19-0.78; P = .008) CONCLUSIONS: Normalization of FC within 12 months of diagnosis is associated with a reduced risk of progression of CD.

Incidence of collagenous colitis in NHS Lothian: a population-based study

OBJECTIVE

Increases in incidence of collagenous colitis (CC) have been documented across Europe; however, previous data from NHS Lothian (1998-2003) demonstrated this to be a low-prevalence area. We aimed to assess incidence of CC in NHS Lothian over time by comparing a more recent cohort (2013-2018) with our existing cohort.

METHODS

All histologically confirmed diagnoses of CC between 2013 and 2018 were obtained from the NHS Lothian colorectal pathology department (Western General Hospital, Edinburgh). Case record review was performed to obtain relevant demographic and clinical data. Data were also collected regarding the availability of colonoscopy in NHS Lothian.

RESULTS

224 cases of CC were diagnosed between 2013 and 2018, compared with 25 between 1998 and 2003. Mean annual incidence rose from 0.5/100 000 population to 4.3/100 000 population. Incidence in females ≥60 years old rose from 2.3/100 000 population to 22.4/100 000 population (p<0.001). The total number of colonoscopies performed increased by 179.1% from 15 262 (1998-2003) to 42 600 (2013-2018), with the number of CC cases per 1000 colonoscopies performed rising from 1.7 to 5.3 (p<0.001).

CONCLUSION

We describe the increasing incidence of CC in Southeast Scotland, with temporal trends comparable to other European countries. The increase is particularly marked in older females and parallels increasing numbers of colonoscopies being performed.

Effectiveness and Safety of Adalimumab Biosimilar SB5 in Inflammatory Bowel Disease: Outcomes in Originator to SB5 Switch, Double Biosimilar Switch and Bio-Naïve SB5 Observational Cohorts

BACKGROUND AND AIMS

Multiple adalimumab [ADA] biosimilars are now approved for use in inflammatory bowel disease [IBD]; however, effectiveness and safety data remain scarce. We aimed to investigate long-term outcomes of the ADA biosimilar SB5 in IBD patients following a switch from the ADA originator [SB5-switch cohort] or after start of SB5 [SB5-start cohort].

METHODS

We performed an observational cohort study in a tertiary IBD referral centre. All IBD patients treated with Humira underwent an elective switch to SB5. We identified all these patients in a biological prescription database that prospectively registered all ADA start and stop dates including brand names. Data on IBD phenotype, C-reactive protein [CRP], drug persistence, ADA drug and antibody levels, and faecal calprotectin were collected.

RESULTS

In total, 481 patients were treated with SB5, 256 in the SB5-switch cohort (median follow-up: 13.7 months [IQR 8.6-15.2]) and 225 in the SB5-start cohort [median follow-up: 8.3 months [4.2-12.8]). Of the SB5-switch cohort, 70.8% remained on SB5 beyond 1 year; 90/256 discontinued SB5, mainly due to adverse events [46/90] or secondary loss of response [37/90]. In the SB5-start cohort, 81/225 discontinued SB5, resulting in SB5-drug persistence of 60.3% beyond 1 year. No differences in clinical remission [p = 0.53], CRP [p = 0.80], faecal calprotectin [p = 0.40] and ADA trough levels [p = 0.55] were found between baseline, week 26 and week 52 following switch. Injection site pain was the most frequently reported adverse event.

CONCLUSION

Switching from ADA originator to SB5 appeared effective and safe in this study with over 12 months of follow-up.

Analysis of colectomy rates for ulcerative colitis in pre- and postbiological eras in Lothian, Scotland

AIM

Biological treatment is effective in maintaining remission in ulcerative colitis (UC), although the effect on colectomy rates remains unclear. In the UK the use of antitumour necrosis factor and anti-α4β7 treatments for maintenance therapy in UC was restricted until 2015. The aim of this study was to describe the impact that this change in the prescribing of biologicals had on colectomy rates for UC.

METHOD

All patients (adult and paediatric) with a diagnosis of UC who received maintenance biological treatment and/or underwent a colectomy in Lothian, Scotland between 2005 and 2018 were identified. Linear and segmental regression analyses were used to identify the annual percentage change (APC) and temporal trends (statistical joinpoints) in biological prescription and colectomy rates.

RESULTS

Rates of initiation of maintenance biological therapy increased from 0.05 per 100 UC patients in 2005 to 1.26 in 2018 (p < 0.001). Colectomy rates per 100 UC patients fell from 1.47 colectomies in 2005 to 0.44 in 2018 (p < 0.001). The APC for colectomy decreased by 4.1% per year between 2005 and 2014 and by 18.9% between 2014 and 2018. Temporal trend analysis (2005-2018) identified a significant joinpoint in colectomy rates in 2014 (p = 0.019).

CONCLUSION

The use of maintenance biological therapy increased sharply following the change in guidance. This has been paralleled by a significant reduction in the rates of colectomy over the same time period.

The ACE (Albumin, CRP and Endoscopy) Index in Acute Colitis: A Simple Clinical Index on Admission that Predicts Outcome in Patients With Acute Ulcerative Colitis

BACKGROUND

Intravenous (IV) steroids remain the first-line treatment for patients with acute ulcerative colitis (UC). However, 30% of patients do not respond to steroids, requiring second-line therapy and/or surgery. There are no existing indices that allow physicians to predict steroid nonresponse at admission. We aimed to determine if admission biochemical and endoscopic values could predict response to IV steroids.

METHODS

All admissions for acute UC (ICD-10 K51) between November 1, 2011, and October 31, 2016 were identified. Case note review confirmed diagnosis; clinical, endoscopic, and laboratory data were collected. Steroid response was defined as discharge home with no further therapy for active UC. Nonresponse was defined as requirement for second-line therapy or surgery. Univariate and binary logistic regression analyses were employed to identify factors associated with steroid nonresponse.

RESULTS

Two hundred and thirty-five acute UC admissions were identified, comprising both acute severe and acute nonsevere UC; 155 of the 235 patients (66.0%) responded to steroids. Admission C-reactive protein (CRP) (P = 0.009, odds ratio [OR] 1.006), albumin (P < 0.001, OR 0.894) and endoscopic severity (P < 0.001, OR 3.166) differed significantly between responders and nonresponders. A simple UC severity score (area under the curve [AUC] 0.754, P < 0.001) was derived from these variables; 78.1% (25 of 32) of patients with concurrent CRP ≥50 mg/L, albumin ≤30 g/L, and increased endoscopic severity (severe on physician's global assessment) (maximum score = 3) did not respond to IV steroids (positive predictive value [PPV] 78.1%, negative predictive value [NPV] 87.1%).

CONCLUSIONS

More than three quarters of patients scoring 3 (albumin ≤30 g/L, CRP ≥50 mg/L, and increased endoscopic severity) did not respond to IV steroids. This combination of parameters (ACE) identifies on admission a high-risk population who may benefit from earlier second-line medical treatment or surgical intervention.

Age and sex-related decline of muscle strength across the adult lifespan: a scoping review of aggregated data

Muscle strength is sex-related and declines with advancing age; yet, a comprehensive comparative evaluation of age-related strength loss in human females and males has not been undertaken. To do so, segmented piecewise regression analysis was performed on aggregated data from studies published from 1990 to 2018 and are available in CINAHL, EMBASE, MEDLINE, and PsycINFO databases. The search identified 5613 articles that were reviewed for physical assessment results stratified by sex and age. Maximal isometric and isokinetic 60°·s^-1 knee extension (KE) and knee flexion (KF) contractions from 57 studies and 15 283 subjects (N = 7918 females) had sufficient data reported on females and males for meaningful statistical evaluation to be undertaken. The analysis revealed that isometric KE and KF strength undergo similar rapid declines in both sexes late in the sixth decade of life. Yet, there is an abrupt age-related decline in KE 60°·s^-1 peak torque earlier in females (aged 41.8 years) than males (aged 66.7 years). In the assessment of KF peak torque, an age-related acceleration in strength loss was only identified in males (aged 49.3 years). The results suggest that age-related isometric strength loss is similar between sexes while the characteristics of KE and KF peak torque decline are sex-related, which likely explains the differential rate of age-related functional decline. Novelty Inclusion of muscle strength and torque of KE and KF data from >15 000 subjects. Isometric KE and KF strength loss are similar between sexes. Isokinetic 60°·s^-1 KE torque decline accelerates 25 years earlier in females and female age-related KF peak torque decline does not accelerate with age.

British Society of Gastroenterology guidance for management of inflammatory bowel disease during the COVID-19 pandemic

The COVID-19 pandemic is putting unprecedented pressures on healthcare systems globally. Early insights have been made possible by rapid sharing of data from China and Italy. In the UK, we have rapidly mobilised inflammatory bowel disease (IBD) centres in order that preparations can be made to protect our patients and the clinical services they rely on. This is a novel coronavirus; much is unknown as to how it will affect people with IBD. We also lack information about the impact of different immunosuppressive medications. To address this uncertainty, the British Society of Gastroenterology (BSG) COVID-19 IBD Working Group has used the best available data and expert opinion to generate a risk grid that groups patients into highest, moderate and lowest risk categories. This grid allows patients to be instructed to follow the UK government's advice for shielding, stringent and standard advice regarding social distancing, respectively. Further considerations are given to service provision, medical and surgical therapy, endoscopy, imaging and clinical trials.

The Methyl-CpG-Binding Protein Mbd2 Regulates Susceptibility to Experimental Colitis via Control of CD11c+ Cells and Colonic Epithelium

Methyl-CpG-binding domain-2 (Mbd2) acts as an epigenetic regulator of gene expression, by linking DNA methylation to repressive chromatin structure. Although Mbd2 is widely expressed in gastrointestinal immune cells and is implicated in regulating intestinal cancer, anti-helminth responses and colonic inflammation, the Mbd2-expressing cell types that control these responses are incompletely defined. Indeed, epigenetic control of gene expression in cells that regulate intestinal immunity is generally poorly understood, even though such mechanisms may explain the inability of standard genetic approaches to pinpoint the causes of conditions like inflammatory bowel disease. In this study we demonstrate a vital role for Mbd2 in regulating murine colonic inflammation. Mbd2^−/− mice displayed dramatically worse pathology than wild type controls during dextran sulfate sodium (DSS) induced colitis, with increased inflammatory (IL-1β⁺) monocytes. Profiling of mRNA from innate immune and epithelial cell (EC) populations suggested that Mbd2 suppresses inflammation and pathology via control of innate-epithelial cell crosstalk and T cell recruitment. Consequently, restriction of Mbd2 deficiency to CD11c⁺ dendritic cells and macrophages, or to ECs, resulted in increased DSS colitis severity. Our identification of this dual role for Mbd2 in regulating the inflammatory capacity of both CD11c⁺ cells and ECs highlights how epigenetic control mechanisms may limit intestinal inflammatory responses.

IBD prevalence in Lothian, Scotland, derived by capture-recapture methodology

OBJECTIVE

IBD prevalence is estimated to be rising, but no detailed, recent UK data are available. The last reported prevalence estimate in the UK was 0.40% in 2003. We aimed to establish the current, and project future, prevalence in Lothian, Scotland.

DESIGN

We conducted an all-age multiparameter search strategy using inpatient IBD international classification of disease (ICD-10) coding (K50/51)(1997-2018), IBD pathology coding (1990-2018), primary and secondary care prescribing data (2009-2018) and a paediatric registry, (1997-2018) to identify 'possible' IBD cases up to 31/08/2018. Diagnoses were manually confirmed through electronic health record review as per Lennard-Jones/Porto criteria. Autoregressive integrated moving average (ARIMA) regression was applied to forecast prevalence to 01/08/2028.

RESULTS

In total, 24 601 possible IBD cases were identified of which 10 499 were true positives. The point prevalence for IBD in Lothian on 31/08/2018 was 784/100 000 (UC 432/100 000, Crohn's disease 284/100 000 and IBD unclassified (IBDU) 68/100 000). Capture-recapture methods identified an additional 427 'missed' cases (95% CI 383 to 477) resulting in a 'true' prevalence of 832/100 000 (95% CI 827 to 837).Prevalence increased by 4.3% per year between 2008 and 2018 (95% CI +3.7 to +4.9%, p<0.0001). ARIMA modelling projected a point prevalence on 01/08/2028 of 1.02% (95% CI 0.97% to 1.07%) that will affect an estimated 1.53% (95% CI 1.37% to 1.69%) of those >80 years of age.

CONCLUSIONS

We report a rigorously validated IBD cohort with all-age point prevalence on 31/08/2018 of 1 in 125, one of the highest worldwide.

Association Between Level of Fecal Calprotectin and Progression of Crohn's Disease

BACKGROUND & AIMS

Mucosal healing is associated with improved outcomes in patients with Crohn's disease (CD), but assessment typically requires ileocolonoscopy. Calprotectin can be measured in fecal samples to determine luminal disease activity in place of endoscopy-this measurement is an important component of the treat-to-target strategy. We investigated whether levels of fecal calprotectin are associated with subsequent CD progression.

METHODS

We performed a retrospective study of 918 patients with CD (4218 patient-years of follow-up evaluation; median, 50.6 mo; interquartile range [IQR], 32.8-76.0 mo) managed at a tertiary medical center in Edinburgh, United Kingdom, from 2003 through 2015. Patients were included if they had 1 or more fecal calprotectin measurements made 3 months or more after their diagnosis. We collected clinical data and fecal calprotectin measurements and analyzed these data to identify factors associated with a composite outcome of progression in Montreal behavior, hospitalization, and resection.

RESULTS

An increased level of fecal calprotectin at the index visit was associated with subsequent progression of CD, independent of symptoms or disease location. The median level of fecal calprotectin at the index visit was 432 μg/g (IQR, 1365-998 μg/g) in patients who reached the composite end point vs 180 μg/g (IQR, 50-665 μg/g) in patients who did not. In multivariable analysis, a cut-off value of 115 μg/g calprotectin identified patients who met the end point with a hazard ratio of 2.4 (95% CI, 1.8-3.1; P < .0001).

CONCLUSIONS

In a retrospective analysis of patients with CD, we found that measurements of fecal calprotectin made during routine monitoring can identify patients at risk for disease progression, independent of symptoms or disease location. It is therefore important to screen asymptomatic patients for mucosal inflammation and pursue complete resolution of inflammation.

Real-world Effectiveness and Safety of Vedolizumab for the Treatment of Inflammatory Bowel Disease: The Scottish Vedolizumab Cohort

BACKGROUND & AIMS

Vedolizumab is an anti-a4b7 monoclonal antibody that is licensed for the treatment of moderate to severe Crohn's disease and ulcerative colitis. The aims of this study were to establish the real-world effectiveness and safety of vedolizumab for the treatment of inflammatory bowel disease.

METHODS

This was a retrospective study involving seven NHS health boards in Scotland between June 2015 and November 2017. Inclusion criteria included: a diagnosis of ulcerative colitis or Crohn's disease with objective evidence of active inflammation at baseline (Harvey-Bradshaw Index[HBI] ≥5/Partial Mayo ≥2 plus C-reactive protein [CRP] >5 mg/L or faecal calprotectin ≥250 µg/g or inflammation on endoscopy/magnetic resonance imaging [MRI]); completion of induction; and at least one clinical follow-up by 12 months. Kaplan-Meier survival analysis was used to establish 12-month cumulative rates of clinical remission, mucosal healing, and deep remission [clinical remission plus mucosal healing]. Rates of serious adverse events were described quantitatively.

RESULTS

Our cohort consisted of 180 patients with ulcerative colitis and 260 with Crohn's disease. Combined median follow-up was 52 weeks (interquartile range [IQR] 26-52 weeks). In ulcerative colitis, 12-month cumulative rates of clinical remission, mucosal healing, and deep remission were 57.4%, 47.3%, and 38.5%, respectively. In Crohn's disease, 12-month cumulative rates of clinical remission, mucosal healing, and deep remission were 58.4%, 38.9%, and 28.3% respectively. The serious adverse event rate was 15.6 per 100 patient-years of follow-up.

CONCLUSIONS

Vedolizumab is a safe and effective treatment for achieving both clinical remission and mucosal healing in ulcerative colitis and Crohn's disease.

Faecal Calprotectin and Magnetic Resonance Enterography in Ileal Crohn's Disease: Correlations Between Disease Activity and Long-Term Follow-Up

BACKGROUND AND AIMS

Magnetic resonance enterography [MRE] is the gold standard for assessing ileal inflammation in Crohn's disease [CD]. The aim of the present study was to correlate faecal calprotectin [FC] to MRE via a simple score in an exclusive ileal cohort with long-term follow-up for association with time to surgery or biologic therapy.

METHODS

In total, 150 MRE studies with matched FC [±30 days] were identified from the Edinburgh FC Register [2008-12; n = 18138]. Scans were re-read blinded to clinical data, independently, by two expert gastrointestinal radiologists, to generate a simple MRE score [range 0-10] from assessment of the worst intestinal segment plus total disease extent.

RESULTS

In total, 119 MRE scans were evaluated from 104 patients with ileal CD [L1 or L3 with panproctocolectomy]. Receiver operating characteristic analysis showed an area under the curve of 0.77 [0.67-0.87, p < 0.0001] for FC and MRE score >1, with an optimal cut-off of 145 μg/g for severe inflammation on MRE with 69.3% [57.6-79.5] sensitivity and 71.4% [53.7-85.4] specificity. Long-term follow-up over a median [interquartile range] of 2086 days [1786-2353] revealed FC ≥ 145 μg/g was associated with reduced biologic-free survival until 3 years following MRE, whereas MRE score [severe vs absent] was associated with reduced surgery- and biologic-free survival throughout follow-up. Backwards stepwise logistic regression revealed that length of ileal disease (odds ratio [OR] 3.8, 1.1-13.2, p = 0.034) and increased bowel wall thickness at MRE [OR 4.2, 1.6-10.7, p < 0.0001] or female sex [OR 5.2, 1.5-18.7, p = 0.011] increased the risk of biologic use or surgery, respectively.

CONCLUSIONS

FC correlates well with MRE assessment of ileal CD with MRE parameters associated with long-term biologic- and surgery-free remission.

Dynamics of Colon Monocyte and Macrophage Activation During Colitis

Background: Macrophages are pivotal in coordinating a range of important processes in the intestines, including controlling intracellular infections and limiting damaging inflammation against the microbiota. However, it is not clear how gut macrophages, relative to recruited blood monocytes and other myeloid cells, contribute to the intestinal inflammatory milieu, nor how macrophages and their monocyte precursors mediate recruitment of other immune cells to the inflamed intestine. Methods: Myeloid cell populations isolated from colonic inflammatory bowel disease (IBD) or murine dextran sulphate sodium (DSS) induced colitis were assessed using flow cytometry and compared to healthy controls. In addition, mRNA expression profiles in human and murine colon samples, and in macrophages and monocytes from healthy and inflamed murine colons, were analysed by quantitative PCR (qPCR) and mRNA microarray. Results: We show that the monocyte:macrophage balance is disrupted in colon inflammation to favour recruitment of CD14+HLA-DRInt cells in humans, and Ly6CHi monocytes in mice. In addition, we identify that murine blood monocytes receive systemic signals enabling increased release of IL-1β prior to egress from the blood into the colon. Further, once within the colon and relative to other myeloid cells, monocytes represent the dominant local source of both IL-1β and TNF. Finally, our data reveal that, independent of inflammation, murine colon macrophages act as a major source of Ccl7 and Ccl8 chemokines that trigger further recruitment of their pro-inflammatory monocyte precursors. Conclusions: Our work suggests that strategies targeting macrophage-mediated monocyte recruitment may represent a promising approach for limiting the chronic inflammation that characterises IBD.

Chromatic techniques for in vivo monitoring jaundice in neonate tissues

OBJECTIVE

A chromatic method is described for providing a preliminary indication of unacceptable bilirubin levels in a newly born baby in order to avoid the development of serious mental deficiencies. The aim was to investigate the reliability of a new chromatic approach using a novel template unit for a preliminary, non-invasive monitoring of the skin tissue of newly born babies with jaundice and its capability for use with different mobile phone cameras.

APPROACH

A description of the monitoring system is given along with an explanation of the monitoring technique used. Preliminary tests have been performed on 48 different neonates each being addressed by one of six different mobile phone cameras, which were randomly available to the operating clinicians.

MAIN RESULTS

The test results have a correlation (R ²) of 0.81, a sensitivity (Sn) of 0.97, a specificity (Sp) of 0.82, a positive predictive value (PPV) of 0.95 and a negative predictive value (NPV) of 0.9.

SIGNIFICANCE

The significance of the results obtained is that they show the approach to have a high level of fail-safe reliability in indicating the bilirubin levels when compared with blood test results. The results also show that the approach can be used with a few different mobile phone cameras and that because of its non-invasive nature and its cost effectiveness, has the potential for remote use from a medical hospital to provide an immediate preliminary diagnosis.

Cancer Therapy: Phenothiazines in an Unexpected Role

Four lines of evidence (clinical findings, epidemiology, inhibition of tumor growth together with prolongation of survival time, and mechanism of action) which suggest that certain phenothiazines, particularly chlorpromazine, possess a range of anti-neoplastic activities in man and in rodents which has not been generally recognised are reviewed and discussed. Chlorpromazine interferes with energy production in sensitive tumours; the mode of action appears to correspond to autooxidative cellular injury, a common form of cell death.

Stretch training induces unequal adaptation in muscle fascicles and thickness in medial and lateral gastrocnemii

This study compared adaptations in fascicle lengths, pennation angles, and muscle thickness of the lateral and medial gastrocnemii in response to 6 weeks of stretch training. The nondominant plantar flexors of 11 males were stretched five times per week for 6 weeks and compared with the contralateral leg and a nonstretched control group of 10 males. During stretch training, instantaneous electromyography was utilized to ensure passive muscle stretch. At baseline, week three, week six and 1 week after the conclusion of stretch training, ultrasound was used to measure fascicle lengths, pennation angles, muscle thickness of the lateral gastrocnemius and medial gastrocnemius, and Achilles tendon thickness and length. Plantar flexion torque was measured, and voluntary activation was assessed. Muscle thickness increased 5.6% after 6 weeks of stretch training (P=.009). The fascicles in the lateral gastrocnemius lengthened to a greater extent than the medial. Overall, fascicles lengthened 25% (P<.001) in the muscle tendon junction and 5.1% (P<.001) in the muscle belly. Pennation angles were unchanged in the medial gastrocnemius but decreased in the lateral gastrocnemius 7.1% (P=.02). There was no change in maximal voluntary contraction, voluntary activation, tendon length, or thickness. This study demonstrates that stretch training is a viable modality to alter muscle architecture of the human gastrocnemius through lengthening of muscle fascicles, decreasing pennation angles, and increasing muscle thickness, albeit adaptations are unequal between the lateral and medial heads.

Concurrence of Frailty and Parkinson's Disease

BACKGROUND

Females with Parkinson's disease (PD) are at greater risk of frailty than males. Little is known about how age and disease-related characteristics influence frailty in females with PD because frailty studies often exclude persons with underlying neurological pathologies.

OBJECTIVE

To determine age and disease-related characteristics that best explain physical frailty in community-dwelling females with and without PD.

DESIGN AND MEASUREMENT

Correlation coefficients described relationships between PD-related characteristics and physical frailty phenotype criteria (Cardiovascular Health Study). Regression analysis identified associations between disease-related characteristics and frailty in non-PD and PD females.

SETTING

Community-dwelling.

PARTICIPANTS

Females with mild to moderate PD (n = 17, mean age = 66 ± 8.5 years) and non-PD (n = 18, mean age = 72 ± 13.2 years) participated.

RESULTS

Daily carbidopa-levodopa dose best explained frailty in PD females (β = 0.5), whereas in non-PD females, age (β = 0.7) and comorbidity (β = 0.5) were most associated with frailty.

CONCLUSIONS

Dopaminergic medication explained frailty in PD and not measures of disease progression (i.e. severity, duration). In females without PD age-related accumulation of comorbidities resulted in greater risk of frailty. This indicates dopaminergic management of PD symptoms may better reflect frailty in females with PD than disease severity or duration. These data suggest the influence of underlying frailty should be considered when managing neurological conditions. Understanding how frailty concurrently exists with PD and how these conditions progress within the aging female will facilitate future care management.

How Do Community Physical and Occupational Therapists Classify Frailty? A pilot Study

BACKGROUND

Frailty is a complex geriatric syndrome that is often difficult to diagnose, especially by healthcare professionals working in the community. Objectives, Measurements: This study examined how physical and occupational therapists classified community-dwelling clients using categories of 'nonfrail', 'prefrail' or 'frail' as compared to measurements of established frailty criteria from the Cardiovascular Health Study frailty index (CHSfi).

RESULTS

Results indicate that community therapists underestimate frailty in comparison to the CHSfi. Therapists' classification of frailty suggested their perceptions of frailty may not only relate to client's functional capacity, but the context in which the client receives care.

CONCLUSION

A multi-dimensional approach is required to capture all aspects of frailty across the healthcare continuum that accounts for how the client thrives within their personal environment.

Systematic review: The use of thiopurines or anti-TNF in post-operative Crohn's disease maintenance--progress and prospects

BACKGROUND

Post-operative recurrence of Crohn's disease is an important management challenge, with 2-year recurrence rates defined by clinical, endoscopic and radiological parameters of up to 77%, 64% and 49%. Clinical and severe endoscopic recurrence vary widely in controlled trials from 13% to 36% and 22% to 56% with thiopurine treatment or 0% and 9% with infliximab treatment respectively at 1 year.

AIMS

To provide a review of the evidence for thiopurine or anti-TNF use in post-operative Crohn's disease, and to assess the ability to identify those patients at highest risk of recurrent disease.

METHODS

A literature search was undertaken using Medline, Embase and Cochrane databases to identify studies using search terms 'thiopurine', 'azathioprine', 'mercaptopurine', 'Infliximab', 'adalimumab', 'Anti-TNF', 'Crohn's disease', 'post-operative' and 'recurrence'.

RESULTS

Trials to examine this important area have proved difficult to execute, with recruitment and retention of patients posing major challenges to randomised clinical trials. There have been four RCTs of 433 patients of thiopurine therapy (with three meta-analyses of these data), and one of anti-TNF therapy involving 24 patients. Overall the efficacy data for thiopurine use in this setting are inconclusive, and other than smoking, there are no consistent predictors of post-operative relapse.

CONCLUSIONS

At present, evidence for routine use of thiopurine treatment in post-operative Crohn's disease is heterogeneous and unconvincing. Stratification by risk of relapse emerges as a key challenge in post-operative management that needs to be addressed, using clinical parameters and emerging biomarkers. The evidence for prophylactic anti-TNF use is limited though promising, with its routine use guided by early assessment of relapse.

Precision high-value resistance scaling with a two-terminal cryogenic current comparator

We describe a cryogenic two-terminal high-resistance bridge and its application in precision resistance scaling from the quantized Hall resistance (QHR) at RH = RK/2 = 12 906.4035 Ω to decade resistance standards with values between 1 MΩ and 1 GΩ. The design minimizes lead resistance errors with multiterminal connections to the QHR device. A single variable voltage source and resistive ratio windings are utilized to achieve excellent dynamic stability, which is not readily obtained in low-current measurements with conventional cryogenic current comparators (CCCs). Prototypes of this bridge have been verified by a successful international comparison of high-resistance scaling using two-terminal CCCs in the national metrology institutes of Argentina, Mexico, and the United States.

Impact of antibiotic treatment for pulmonary exacerbations on bacterial diversity in cystic fibrosis

BACKGROUND

A diverse array of bacterial species is present in the CF airways, in addition to those recognised as clinically important. Here, we investigated the relative impact of antibiotics, used predominantly to target Pseudomonas aeruginosa during acute exacerbations, on other non-pseudomonal species.

METHODS

The relative abundance of viable P. aeruginosa and non-pseudomonal species was determined in sputa from 12 adult CF subjects 21, 14, and 7 days prior to antibiotics, day 3 of treatment, the final day of treatment, and 10-14 days afterwards, by T-RFLP profiling.

RESULTS

Overall, relative P. aeruginosa abundance increased during antibiotic therapy compared to other bacterial species; mean abundance pre-antibiotic 51.0±36.0% increasing to 71.3±30.4% during antibiotic (ANOVA: F(1,54)=5.16; P<0.027). Further, the number of non-pseudomonal species detected fell; pre-antibiotic 6.0±3.3 decreasing to 3.7±3.3 during treatment (ANOVA: F(1,66)=5.11; P<0.027).

CONCLUSIONS

Antibiotic treatment directed at P. aeruginosa has an additional significant impact on non-pseudomonal, co-colonising species.

Mechanism of association between BMI and dysfunction of the gastro-oesophageal barrier in patients with normal endoscopy

INTRODUCTION

The association between body mass index (BMI) and gastro-oesophageal pressure gradient (GOPG) is incompletely understood. We examined the association between BMI and gastro-oesophageal (GO) barrier function and the effect of mechanically increasing intra-abdominal pressure on GO physiology.

METHODS

(A) 103 dyspeptic patients with normal endoscopy underwent 24 h pH-metry and upper gastrointestinal manometry. Relationships between BMI and acid reflux, intragastric pressure (IGP), GOPG and lower oesophageal sphincter (LOS) pressure were calculated using bivariate correlations. (B) In 18 healthy volunteers, the effects of increasing IGP by abdominal belt on GO manometry were studied.

RESULTS

(A) There was a linear correlation between BMI and oesophageal acid exposure in erect (R=0.35, p<0.001) and supine (R=0.40, p<0.001) positions. BMI was strongly associated with IGP (inspiration: R=0.66, p<0.001; expiration: R=0.78, p<0.001) and inspiratory GOPG (R=0.50, p<0.001). There were a positive correlation between BMI and inspiratory LOS pressure relative to atmospheric pressure (R=0.29, p=0.016) and a negative correlation with LOS pressure relative to IGP on expiration (R=-0.25, p=0.018). Logistic regression models using all significant manometric variables and relevant interactions revealed marked decline in the magnitude and significance of relationship between BMI and oesophageal acid exposure in supine (from OR 1.12 (95% CI 1.03 to 1.22), p=0.009, to 1.00 (0.86 to 1.17), p=0.999) and upright positions (from 1.11 (1.02 to 1.20), p=0.020, to 1.03 (0.89 to 1.18), p=0.717). (B) Application of the constricting abdominal belt produced similar manometric changes to those associated with increased BMI. However, the belt did not reproduce the reduced LOS pressure relative to IGP.

CONCLUSION

The association between reflux and BMI may be largely explained by effects of increased intra-abdominal pressure. However, the reduced LOS pressure associated with BMI may be mediated by another mechanism or effects of chronic rather than acute elevation of intra-abdominal pressure.

Audit of acute Charcot's disease in the UK: the CDUK study

AIMS/HYPOTHESIS

We studied factors associated with the development and resolution of acute Charcot foot using a web-based observational study.

METHODS

Clinicians managing cases of acute Charcot foot in the UK and Ireland between June 2005 and February 2007 were invited to register anonymised details on a secure website.

RESULTS

A total of 288 cases (age 57.0 ± 11.3 years [mean ± SD]; 71.2% male) were registered from 76 centres. Of these, 36% of patients recalled an episode of relevant trauma in the preceding 6 months, while 12% had had surgery to the affected foot. In 101 (35%) cases, ulceration was present at registration and 20% of these had osteomyelitis. Non-removable off-loading devices were used at presentation in 35.4% of cases, with removable off-loading used in 50%. Data on resolution were available for 219 patients. The median time to resolution was 9 months in patients whose initial management included the use of non-removable off-loading, compared with 12 months in the remainder (p = 0.001). Bisphosphonates were administered intravenously in 25.4% and orally in 19.4% of cases. The median time to resolution in patients who received bisphosphonates was 12 months and was longer than in those who did not (10 months, p = 0.005).

CONCLUSIONS/INTERPRETATION

The median time to resolution was longer than in earlier series. Although limited by being observational and non-randomised, these data suggest that the use of non-removable off-loading at presentation may shorten the time to resolution. They provide no evidence to indicate that the use of bisphosphonates is beneficial.

BMI is superior to symptoms in predicting response to proton pump inhibitor: randomised trial in patients with upper gastrointestinal symptoms and normal endoscopy

OBJECTIVES

In most patients undergoing endoscopy for upper gastrointestinal (GI) symptoms in the Western world, no macroscopic abnormality or evidence of Helicobacter pylori infection is identified. Following this negative investigation, proton pump inhibitor (PPI) therapy is usually prescribed. The aim of this study was to assess the value of such treatment compared with placebo and to identify predictors of response.

DESIGN

Prospective parallel randomised study.

SETTING

Dyspepsia Research Clinic.

PARTICIPANT

105 patients (49 men, median age 44 years, IQR 22) with normal endoscopy and H pylori negative with ongoing upper GI symptoms following 2-week run-in period. Intervention Full demographic symptom severity and characteristics were assessed and 24 h oesophageal pH metry and oesophageal manometry were performed prior to randomisation to 2 weeks of treatment with lansoprazole 30 mg/day or placebo (2:1), with reassessment of symptom severity during the second week of treatment.

PRIMARY OUTCOME

50% reduction in Glasgow Dyspepsia Severity Score (GDSS).

RESULTS

According to intention to treat analysis, the response was 35.7% for the active group and 5.7% for the placebo group (p < 0001). The only non-invasive independent predictor of response to PPI in multivariable analysis was the patient's body mass index (BMI) (p = 0.003). The association of BMI with response to PPI was apparent across the full range of quartiles (p values for trend=0.01). BMI had a similar predictive value to either 24 h oesophageal pH metry or manometry. Predominant symptom and symptom subgroups were unhelpful in predicting the response to PPI. Including all pretreatment assessments, only BMI (p < 0.05) and lower oesophageal sphincter pressure (p < 0.05) were independent predictors of response.

CONCLUSION

The response to PPI therapy is likely to be related to underlying acid reflux. The strong predictive value of BMI is probably due to its association with underlying reflux disease and the fact that it is a more objective and reproducible measure than symptom characteristics. It is recommended that BMI should be measured in patients with upper GI symptoms. Trial Registration Number ISRCTN 32863375.

Comparison of extraction of a β-blocker from plasma onto a molecularly imprinted polymer with liquid–liquid extraction and solid phase extraction methods

An optimised solid phase extraction (SPE) method developed for the extraction of a structural analogue of the beta-blocking drug propranolol from plasma utilising a molecularly imprinted polymer (MIP) has been compared with methods based on conventional liquid-liquid extraction (LLE), and SPE using C18-bonded and immobilised phenyl boronic acid (PBA). All four methods could be used for the extraction of the analyte with acceptable accuracy and precision. The MIP-based method, unlike the other methods required a protein precipitation step prior to extraction to eliminate the effects of co-extracted protein. The best performance was seen with the LLE method followed by SPE on the C18 phase. The MIP-based method represented no advantage over the comparator methods for this analyte. Indeed the performance of the MIP-based method was marginally worse as leaching of low level template impurities prevented detection of the target analyte at low concentrations (5 ngmL(-1)). This relatively poorer performance was evident as worse accuracy at low concentrations with a consequent higher limit of quantification than the conventional methods.

Passive immunization of rainbow trout, Oncorhynchus mykiss (Walbaum), against Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease and rainbow trout fry syndrome

Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease (CWD) and rainbow trout fry syndrome (RTFS), causes high mortality in cultured salmonids. The present study was designed to determine the role antibody plays in conferring protection to rainbow trout fry, Oncorhynchus mykiss (Walbaum), by passive immunization with convalescent serum or serum from adult rainbow trout immunized with F. psychrophilum, and goat anti-F. psychrophilum serum. In each experiment, rainbow trout fry were injected intraperitoneally with antiserum and challenged by subcutaneous injection with a virulent strain (CSF-259-93) of F. psychrophilum 24-h post-immunization. Relative percentage survival (RPS) ranged from 9-42% when rainbow trout fry (mean weight 1.3 g) were injected with a 1:2 dilution of 25 microL of convalescent serum ranging in enzyme-linked immunosorbent assay antibody titres from 1600-102400. Rainbow trout fry (mean weight 1.0 g) passively immunized with 25 microL of serum from immunized adult fish exhibited RPS values of up to 57%. In each of these experiments, RPS increased with increasing antibody titres against F. psychrophilum. Passive immunization with 25 or 50 microL goat anti-F. psychrophilum serum, however, did not confer protection to fry (mean weight 1.3 g). These results suggest that trout antibody plays a role in conferring protection to F. psychrophilum, but antibody alone is unable to provide complete protection.

Structure, stability and folding of the alpha-helix

Pauling first described the alpha-helix nearly 50 years ago, yet new features of its structure continue to be discovered, using peptide model systems, site-directed mutagenesis, advances in theory, the expansion of the Protein Data Bank and new experimental techniques. Helical peptides in solution form a vast number of structures, including fully helical, fully coiled and partly helical. To interpret peptide results quantitatively it is essential to use a helix/coil model that includes the stabilities of all these conformations. Our models now include terms for helix interiors, capping, side-chain interactions, N-termini and 3(10)-helices. The first three amino acids in a helix (N1, N2 and N3) and the preceding N-cap are unique, as their amide NH groups do not participate in backbone hydrogen bonding. We surveyed their structures in proteins and measured their amino acid preferences. The results are predominantly rationalized by hydrogen bonding to the free NH groups. Stabilizing side-chain-side-chain energies, including hydrophobic interactions, hydrogen bonding and polar/non-polar interactions, were measured accurately in helical peptides. Helices in proteins show a preference for having approximately an integral number of turns so that their N- and C-caps lie on the same side. There are also strong periodic trends in the likelihood of terminating a helix with a Schellman or alpha L C-cap motif. The kinetics of alpha-helix folding have been studied with stopped-flow deep ultraviolet circular dichroism using synchrotron radiation as the light source; this gives a far superior signal-to-noise ratio than a conventional instrument. We find that poly(Glu), poly(Lys) and alanine-based peptides fold in milliseconds, with longer peptides showing a transient overshoot in helix content.

Massive hepatosplenomegaly caused by Penicillium marneffei associated with human immunodeficiency virus infection in a Thai patient

A 29 year old Thai woman presented with non-specific features and examination revealed left upper zone consolidation and hepatosplenomegaly. The initial clinical differential diagnosis included tuberculosis and melioidosis. She died four days after admission, while still under investigation. Postmortem examination revealed antibodies to human immunodeficiency virus, disseminated Penicillium marneffei infection, and Salmonella enteritidis infection. Penicillium marneffei is a well described AIDS defining pathogen in South East Asia but is very rare in the UK. Appropriate antifungal treatment may be associated with a successful outcome. Increased awareness of this clinical association may enable correct diagnosis in affected patients from South East Asia presenting within the UK.

Stabilizing nonpolar/polar side-chain interactions in the alpha-helix

A simplistic, yet often used, view of protein stability is that amino acids attract other amino acids with similar polarity, whereas nonpolar and polar side chains repel. Here we show that nonpolar/polar interactions, namely Val or Ile bonding to Lys or Arg in alpha-helices, can in fact be stabilizing. Residues spaced i, i + 4 in alpha-helices are on the same face of the helix, with potential to favorably interact and stabilize the structure. We observe that the nonpolar/polar pairs Ile-Lys, Ile-Arg, and Val-Lys occur in protein helices more often than expected when spaced i, i + 4. Partially helical peptides containing pairs of nonpolar/polar residues were synthesized. Controls with i, i + 5 spacing have the residues on opposite faces of the helix and are less helical than the test peptides with the i, i + 4 interactions. Experimental circular dichroism results were analyzed with helix-coil theory to calculate the free energy for the interactions. All three stabilize the helix with DeltaG between -0.14 and -0.32 kcal x mol(-1). The interactions are hydrophobic with contacts between Val or Ile and the alkyl groups in Arg or Lys. Side chains such as Lys and Arg can thus interact favorably with both polar and nonpolar residues.

The incidence of hematuria in middle distance track running

The purpose of this study was to establish if middle distance track athletes experience hematuria during their competitive season interval workouts and, if so, what type of workout based on intensity and distance was most associated with hematuria. During a 4-week observational period, athletes (n = 10) underwent reagent strip urinalysis before and after their twice weekly interval sessions. Positive samples for hematuria were analyzed microscopically to accurately determine red blood cell (RBC) loss. Seventy-one individual interval workouts were observed, of which 32 cases of hematuria were reported. Nine cases of hematuria exhibited >100 RBC per High Power Field (Hpf). Furthermore, 90% of the athletes experienced post-workout hematuria at least once. The highest incidence of hematuria was observed after workouts run at 110% of VO(2peak) over short (600-1,500 m) to moderate (1,501-3,000 m) distances. All post-exercise cases of hematuria resolved within 2 hr of recovery.

Protection of rainbow trout against infectious hematopoietic necrosis virus four days after specific or semi-specific DNA vaccination

A DNA vaccine against a fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV), was shown to provide significant protection as soon as 4 d after intramuscular vaccination in 2 g rainbow trout (Oncorhynchus mykiss) held at 15 degrees C. Nearly complete protection was also observed at later time points (7, 14, and 28 d) using a standardized waterborne challenge model. In a test of the specificity of this early protection, immunization of rainbow trout with a DNA vaccine against another fish rhabdovirus, viral hemorrhagic septicemia virus, provided a significant level of cross-protection against IHNV challenge for a transient period of time, whereas a rabies virus DNA vaccine was not protective. This indication of distinct early and late protective mechanisms was not dependent on DNA vaccine doses from 0.1 to 2.5 microg.

(Z)-3-hexenyl (R)-3-hydroxybutanoate: a male specific compound in three North American decorator wasps Eucerceris rubripes, E. conata and E. tricolor

The males of the decorator wasps Eucerceris have been observed to display abdomen-dragging behavior on plants surrounding their nest. It is thought that this applies a territorial-marking sex pheromone that serves to alert females to the males' territory for courtship and mating. The extracts of three species E. rubripes, E. conata, and E. tricolor have been analyzed by GC-MS. The gas chromatograms revealed the presence, in large quantities, of one common volatile compound in the male head extracts. By analogy with the closely related bee wolves Philanthus, we believe the pheromone is produced in the mandibular glands. Utilizing mass spectrometry, microreactions, FT-IR, and 1H and 13C NMR spectroscopy the structure of the pheromone was proposed to be (Z)-3-hexenyl 3-hydroxybutanoate, which was confirmed by synthesis. The absolute configuration of the chiral center was determined to be R for the three species by preparing the Mosher esters of the insect samples and comparing their GC retention times with a synthetic sample of known absolute configuration. In addition 2- and 3-hexenoic acid and some aromatic compounds were also found in varying quantities in both males and females along with hydrocarbons and fatty acids, although no species-specific profiles emerged.

An unexpected selectivity of a propranolol-derived molecular imprint for tamoxifen

During the evaluation of molecular imprinted polymers (MIPs) prepared against the drug tamoxifen a propranolol-derived MIP was used as a positive control. Surprisingly the propranolol-derived MIP showed considerable selectivity towards tamoxifen, and was indeed much more selective than the MIP prepared using tamoxifen as the imprint molecule. The consequences of this unexpected, cross reactivity for the use of MIPs in analytical chemistry is discussed.

Defensive role of secretion of ectal mandibular glands of the wasp Polistes dominulus

Ectal mandibular glands of insects are exocrine glands localized in the anterior-lateral region of the head, close to the base of the mandibles. In social wasps, the gland is composed of secretory cells and a reservoir into which the secretion accumulates. At the time of emission the secretion flows onto a specialized cuticular area on the outside of the base of the mandibles. Secretion of Polistes dominulus is emitted only when wasps are greatly disturbed or in the presence of predators, and its function seems to be mainly defensive. Morphometric studies did not reveal any size differences between the glands of the queens and those of the workers. GC-MS analyses of the glands identified 32 compounds, mainly acids and aldehydes in the range C2-C18. The overall odor, caused by the mixture of aldehydes, is distinct. Workers do not respond strongly to the odor. The secretion probably serves as a warning signal to vertebrate predators.

Causes of Alzheimer's disease: paracetamol (acetaminophen) today? Amphetamines tomorrow?

Phenacetin was implicated as a causative factor in Alzheimer's disease (AD) in 1971. Although the chief metabolite, paracetamol, was earlier identified as responsible for its analgesic and antipyretic properties, a link with senile plaque formation does not appear to have been previously suspected. In common with paracetamol, so-called recreational drugs (RDs) likewise stimulate free radical activity, and might therefore pose a similar danger in terms of causing AD later in life. The case for regarding the brain as an even more delicate and vulnerable structure than currently believed, at risk especially from substances untested in man but of proven neurotoxicity in rodents and non-human primates, needs to be taken more seriously than at present.