Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Comparing Effectiveness of a Generic Oral Nutritional Supplement With Specialized Formula in the Treatment of Active Pediatric Crohn's Disease

BACKGROUND

Exclusive enteral nutrition (EEN) is the recommended induction treatment of mild to moderate active pediatric Crohn's disease (CD). This study compared outcomes of 2 proprietary polymeric formulas. Treatment effectiveness was examined along with practical aspects of formula delivery and differences in estimated treatment costs.

METHODS

Data were retrospectively collected from patients with CD who received a generic oral nutritional supplement (Fortisip) across 2 centers (RCH, Melbourne and RHSC, Edinburgh). This was compared with a prospective cohort (RHC, Glasgow) that used a specialized formula (Modulen IBD). The data collected included patient demographics, remission rates, biochemical markers, administration method, and anthropometrics. The estimated treatment cost was performed by comparing price per kcal between each formula.

RESULTS

One hundred seventy-one patients were included (106 Fortisip, 65 Modulen IBD, 70 female; median age 13.3 yrs). No difference was demonstrated in remission rate (Fortisip n = 67 of 106 [63%] vs Modulen IBD n = 41 of 64 [64%], P = .89), nonadherence rate (Fortisip n = 7 of 106 [7%] vs Modulen IBD 3 of 64 [5%], P = .57) or method of administration (NGT Fortisip use n = 16 of 106 [12%] vs Modulen IBD 14 of 65 [22%]; P = .31). There was no difference in reduction of biochemical disease markers between the groups (C-reactive protein , P = .13; erythrocyte sedimentation rate, P = .49; fecal calprotectin, P = .94). However, there was a cost-saving of around £500/patient/course if the generic oral nutritional supplement was used.

CONCLUSIONS

The generic oral nutritional supplement and specialized formulas both had similar clinical effectiveness in induction of remission in pediatric CD. However, there is considerable cost-saving when using a generic oral nutritional supplement.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

A25 THE RISING GLOBAL INCIDENCE OF PEDIATRIC INFLAMMATORY BOWEL DISEASE: A SYSTEMATIC REVIEW OF POPULATION-BASED STUDIES

Background

The incidence of inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is increasing internationally, particularly in developing nations where rates were historically low. Previous reports of the incidence and prevalence of pediatric-onset IBD have identified a paucity of population-based studies.

Aims

We reviewed the global trends in incidence of pediatric IBD using evidence from population-based studies.

Methods

(PROSPERO CRD42019125193) We systematically reviewed studies indexed in MEDLINE, EMBASE, Airiti Library, and SciELO from 01/2010-02/2020 to identify population-based studies reporting the incidence of pediatric-onset IBD, CD, and UC. Included studies combined childhood and adolescent-onset IBD (onset <21y). Changes in incidence since 2000 were plotted by continent, with data from 2000–09 provided by our previous systematic review1. To depict trends, multiple times points reported in single studies were connected on graphs. When incidence was reported as an aggregated estimate over a range of years, data was plotted using the midpoint of the interval.

Results

Of 8096 abstracts screened, 74 studies described the incidence of IBD, CD, or UC in 33 countries (Figure panel A). The incidence of pediatric-onset IBD is highest in Northern Europe and North America, and lowest in Southern Europe, Asia, and the Middle East. This geographical distribution is similar in UC, while incidence of pediatric-onset CD is highest in North America and Northern Europe, followed by Australia. Trends in incidence over time, stratified by continent, are reported in Figure, panel B. Significantly increasing incidence of IBD, CD, and/or UC was reported in China, Bahrain, Canada, New Zealand, Australia, Singapore, Saudi Arabia, and most European countries. Very Early Onset (VEO) IBD significantly increased in Canada, however Saudi Arabia reported decreasing incidence of VEO-CD but stable incidence of VEO-UC.

Conclusions

Conclusion: Incidence of pediatric-onset IBD are highest in Northern Europe and North American and are increasing globally. There remains a paucity of studies from many parts of the world on the incidence pediatric IBD. Further research is needed to understand the pathogenesis of the rising incidence of pediatric IBD, including work to understand the genetic, environmental, immunological and microbiome alterations leading to the increasing rates in children.

References: 1Benchimol, Fortinsky et al. Inflamm Bowel Dis 2011;17:423–39.

Funding Agencies

None

Malignancy and mortality in paediatric-onset inflammatory bowel disease: a 3-year prospective, multinational study from the paediatric IBD Porto group of ESPGHAN

BACKGROUND

Risk benefit strategies in managing inflammatory bowel diseases (IBD) are dependent upon understanding the risks of uncontrolled inflammation vs those of treatments. Malignancy and mortality in IBD have been associated with disease-related inflammation and immune suppression, but data are limited due to their rare occurrence.

AIM

To identify and describe the most common causes of mortality, types of cancer and previous or current therapy among children and young adults with paediatric-onset IBD.

METHODS

Information on paediatric-onset IBD patients diagnosed with malignancy or mortality was prospectively collected via a survey in 25 countries over a 42-month period. Patients were included if death or malignancy occurred after IBD diagnosis but before the age of 26 years.

RESULTS

In total, 60 patients were identified including 43 malignancies and 26 fatal cases (9 due to cancer). Main causes of fatality were malignancies (n = 9), IBD or IBD-therapy related nonmalignant causes (n = 10; including 5 infections), and suicides (n = 3). Three cases, all fatal, of hepatosplenic T-cell lymphoma were identified, all were biologic-naïve but thiopurine-exposed. No other haematological malignancies were fatal. The 6 other fatal cancer cases included 3 colorectal adenocarcinomas and 3 cholangiocarcinomas (CCAs). Primary sclerosing cholangitis (PSC) was present in 5 (56%) fatal cancers (1 colorectal carcinoma, 3 CCAs and 1 hepatosplenic T-cell lymphoma).

CONCLUSIONS

We report the largest number of paediatric-onset IBD patients with cancer and/or fatal outcomes to date. Malignancies followed by infections were the major causes of mortality. We identified PSC as a significant risk factor for cancer-associated mortality. Disease-related adenocarcinomas were a commoner cause of death than lymphomas.

Potential urban runoff impacts and contaminant distributions in shoreline and reservoir environments of Lake Havasu, southwestern United States

Heavy metal, nutrient, and hydrocarbon levels in and adjacent to Lake Havasu, a regionally significant water supply reservoir with a highly controlled, dynamic flow regime, are assessed in relation to possible stormwater runoff impacts from an arid urban center. Shallow groundwater and sediment analyses from ephemeral drainage (wash) mouths that convey stormwater runoff from Lake Havasu City, Arizona to the reservoir, provided contaminant control points and correlation ties with the reservoir environment. Fine-grain sediments tend to contain higher heavy metal concentrations whereas nutrients are more evenly distributed, except low total organic carbon levels from young wash mouth surfaces devoid of vegetation. Heavy metal and total phosphate sediment concentrations in transects from wash mouths into the reservoir have mixed and decreasing trends, respectively. Both series may indicate chemical depositional influences from urban runoff, yet no statistically significant concentration differences occur between specific wash mouths and corresponding offshore transects. Heavy metal pollution indices of all sediments indicate no discernible to minor contamination, indicating that runoff impacts are minimal. Nevertheless, several heavy metal concentrations from mid-reservoir sediment sites increase southward through the length of the reservoir. Continual significant water flow through the reservoir may help to disperse locally derived runoff particulates, which could mix and settle down gradient with chemical loads from upriver sources and local atmospheric deposition. Incorporating the shoreline environment with the reservoir investigation provides spatial continuity in assessing contaminant sources and distribution patterns. This is particularly acute in the investigation of energetic, flow-through reservoirs in which sources may be overlooked if solely analyzing the reservoir environment.

Triggering apoptosis in cancer cells with an analogue of cribrostatin 6 that elevates intracellular ROS

Elevation of reactive oxygen species (ROS) is both a consequence and driver of the upregulated metabolism and proliferation of transformed cells. The resulting increase in oxidative stress is postulated to saturate the cellular antioxidant machinery, leaving cancer cells susceptible to agents that further elevate their intracellular oxidative stress. Several small molecules, including the marine natural product cribrostatin 6, have been demonstrated to trigger apoptosis in cancer cells by increasing intracellular ROS. Here, we report the modular synthesis of a series of cribrostatin 6 derivatives, and assessment of their activity in a number of cell lines. We establish that placing a phenyl ring on carbon 8 of cribrostatin 6 leads to increased potency, and observe a window of selectivity towards cancer cells. The mechanism of activity of this more potent analogue is assessed and demonstrated to induce apoptosis in cancer cells by increasing ROS. Our results demonstrate the potential for targeting tumors with molecules that enhance intracellular oxidative stress.

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12<CR<25). Previous ICF experiments at the NIF utilized high convergence (CR>30) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

Systematic review and meta-analysis: Prevalence and possible causes of vitamin D deficiency and insufficiency in pediatric cancer patients

BACKGROUND AND AIMS

Vitamin D inadequacy is now an internationally recognized health problem and pediatric cancer patients may be at even higher risk than healthy children. We aimed to evaluate primary research to establish the prevalence of vitamin D inadequacy and to explore its possible causes in pediatric cancer patients.

METHODS

Electronic databases were searched (no restriction-Aug 2013) with no language restrictions and keywords related to cancer and vitamin D. We included studies of patients aged <18 years, diagnosed with and treated for cancer and reporting plasma vitamin D status. Evidence was critically appraised employing the CASP tool. Meta-analysis was performed when appropriate.

RESULTS

We included 19 studies, which were mainly of moderate-quality and heterogeneous in the definitions of vitamin D deficiency and insufficiency. The median (range) prevalence of vitamin D deficiency was 14% (0-61.5%) and insufficiency 23% (0-83%). Finally, a significant effect of younger age with vitamin D inadequacy was shown (effect size: -0.132; 95%CI -0.203, -0.060).

CONCLUSION

There is a possibility of a high prevalence of vitamin D inadequacy in pediatric cancer patients, especially older children, urging the need for high-quality population-based longitudinal studies using standard definitions.

Anti-TNF therapy for paediatric IBD: the Scottish national experience

BACKGROUND AND AIMS

Biological agents are being increasingly used in the UK for paediatric-onset inflammatory bowel disease (PIBD) despite limited evidence and safety concerns. We evaluated effectiveness and safety in the clinical setting, highlighting drug cost pressures, using our national Scottish PIBD biological registry.

METHODS

Complete usage of the biological agents, infliximab (IFX) and adalimumab (ADA) for treatment of PIBD (in those aged <18 years) from 1 January 2000 to 30 September 2010 was collated from all treatments administered within the Scottish Paediatric Gastroenterology, Hepatology and Nutrition (PGHAN) national managed service network (all regional PGHAN centres and paediatric units within their associated district general hospitals).

RESULTS

132 children had biological therapy; 24 required both agents; 114 had Crohn's disease (CD), 16 had ulcerative colitis (UC) and 2 had IBD Unclassified (IBDU). 127 children received IFX to induce remission; 61 entered remission, 49 had partial response and 17 had no response. 72 were given maintenance IFX and 23 required dose escalation. 18 had infusion reactions and 27 had adverse events (infections/other adverse events). 29 had ADA to induce remission (28 CD and 1 UC), 24 after IFX; 10 entered remission, 12 had partial response and 7 had no response. All had maintenance; 19 required dose escalation. 12 children overall required hospitalisation due to drug toxicity. No deaths occurred with either IFX or ADA.

CONCLUSIONS

Complete accrual of the Scottish nationwide 'real-life' experience demonstrates moderate effectiveness of anti tumour necrosis factor agents in severe PIBD but duration of effect is limited; significant financial issues (drug cost-need for dose escalation and/or multiple biological usage) and safety issues exist.

Neutron source reconstruction from pinhole imaging at National Ignition Facility

The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the ignition stage of inertial confinement fusion (ICF) implosions at NIF. Since the neutron source is small (∼100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, single-sided tapers in gold. These apertures, which have triangular cross sections, produce distortions in the image, and the extended nature of the pinhole results in a non-stationary or spatially varying point spread function across the pinhole field of view. In this work, we have used iterative Maximum Likelihood techniques to remove the non-stationary distortions introduced by the aperture to reconstruct the underlying neutron source distributions. We present the detailed algorithms used for these reconstructions, the stopping criteria used and reconstructed sources from data collected at NIF with a discussion of the neutron imaging performance in light of other diagnostics.

Measurements of an ablator-gas atomic mix in indirectly driven implosions at the National Ignition Facility

We present the first results from an experimental campaign to measure the atomic ablator-gas mix in the deceleration phase of gas-filled capsule implosions on the National Ignition Facility. Plastic capsules containing CD layers were filled with tritium gas; as the reactants are initially separated, DT fusion yield provides a direct measure of the atomic mix of ablator into the hot spot gas. Capsules were imploded with x rays generated in hohlraums with peak radiation temperatures of ∼294  eV. While the TT fusion reaction probes conditions in the central part (core) of the implosion hot spot, the DT reaction probes a mixed region on the outer part of the hot spot near the ablator-hot-spot interface. Experimental data were used to develop and validate the atomic-mix model used in two-dimensional simulations.

Systematic review: MRI enterography for assessment of small bowel involvement in paediatric Crohn's disease

BACKGROUND

Barium meal enteroclysis (BM) is the recommended imaging technique for small bowel inaccessible by ileo-colonoscopy when diagnosing paediatric-onset inflammatory bowel disease, but it has poor sensitivity and involves ionising radiation. MRI enterography (MRE) is an alternative methodology.

AIMS

To critically appraise the published evidence on MRE in the assessment of Paediatric inflammatory bowel disease by systematic review.

METHODS

Review of all English language data reporting MRE for the investigation of patients <18 years with known or suspected IBD. Primary searches of Medline (Jan 1950-April 2012), Cinahl (1966-April 2012) and Pubmed (Jan 1950-April 2012) were performed using keyword and MeSH terms; IBD; Magnetic resonance imaging; small bowel imaging; EMBASE was then searched. Two authors independently assessed the quality of studies using the quality assessment of diagnostic accuracy studies tool.

RESULTS

Searches yielded 930 035 hits, combination word searches limited to 1983 titles. Fifty-two studies were fully reviewed, 41 were excluded due to lack of paediatric data. Eleven studies of 496 children were included. All studies used endoscopy as the reference test. 10/496 patients required jejunal intubation for bowel preparation. Meta-analysis of six comparable studies gave a pooled sensitivity and specificity for MRE detection of active terminal ileal Crohn's disease of 84% and 97% respectively. Studies displayed heterogeneity in bowel preparation, scanning technique, reporting methodology and timing of ileo-colonoscopy in relation to MRE. In three studies comparing BM, MRE had greater sensitivity and specificity.

CONCLUSIONS

MRE is a sensitive and specific tool for diagnosis in paediatric inflammatory bowel disease. Technical considerations require refinement and standardisation; however, MRE has no radiation. Current data suggest that MRE should supersede BM as the SB imaging technique in centres with appropriate expertise.

The neutron imaging diagnostic at NIF (invited)

A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

Effect of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography-guided management of suspected recurrent papillary thyroid carcinoma: long-term follow-up with tumour marker responses

AIMS

To investigate the use of recombinant human thyroid-stimulating hormone-stimulated co-registered (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for detecting suspected recurrent papillary thyroid carcinoma among patients with rising tumour markers but negative whole-body iodine-131 scans. Tumour marker responses to (18)F-FDG PET/CT-guided therapy were also measured for these patients.

MATERIALS AND METHODS

A prospectively gathered (18)F-FDG PET/CT database and patient charts were reviewed. Patients having previously undergone total thyroidectomy and ablative iodine-131 therapy for papillary carcinoma before (18)F-FDG PET/CT were analysed.

RESULTS

Nineteen patients formed the study population: 12 women and seven men, median age 49 years, with elevated thyroglobulin (n = 15), elevated anti-thyroglobulin antibody (n = 4); the median follow-up was 46 months, range 27-56 months. Sixteen patients (84%) had a positive PET/CT scan (15 with disease confined to the head and neck and one with distant disease), whereas three patients (16%) had a negative scan. Eleven of the 15 patients with disease confined to the head and neck underwent potentially curative salvage therapy: surgery (n = 7), external beam radiotherapy (n = 2) or both (n = 2). All patients undergoing surgery had histological confirmation of malignancy. At a median follow-up of 50 months for these 11 patients, eight had detectable tumour markers at levels below pre-scan values, two had levels above, and one patient had an undetectable level. All three patients with negative PET/CT scans were placed on surveillance. At a median follow-up of 45 months for these three patients, two had tumour marker levels below pre-scan values and one had an undetectable level.

CONCLUSIONS

Recombinant human thyroid-stimulating hormone-stimulated (18)F-FDG PET/CT detected recurrent disease in most patients. Although subsequent treatment of (18)F-FDG PET/CT-detected disease reduced tumour marker levels in most patients, markers remained detectable, suggesting that not all residual or metastatic disease had been identified, which compromised salvage therapy. This is the largest and most mature study to date reporting tumour marker responses to PET- or PET/CT-guided therapy in this setting.

Point sources of emerging contaminants along the Colorado River Basin: source water for the arid Southwestern United States

Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into empty SPEs and eluted with methanol. All extracts were prepared for, and analyzed by, liquid chromatography-electrospray-ion trap mass spectrometry (LC-ESI-ITMS). Log D(OW) values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the yeast estrogen screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicity response. In the grab samples, azithromycin (an antibiotic) was detected in all but one urban waste stream, with concentrations ranging from 30ng/L to 2800ng/L. Concentration levels of azithromycin, methamphetamine and pseudoephedrine showed temporal variation from the Tucson WWTP. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10ng/L), but most were below detection limits.

Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 μm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).

The effects of anti-TNF-α treatment with adalimumab on growth in children with Crohn's disease (CD)

INTRODUCTION

Adalimumab is used to treat children with Crohn's disease (CD), but the effects of adalimumab on growth in CD have not been studied.

AIM

To study growth and disease activity over 12 months (6 months prior to (T-6), baseline (T0) and for 6 months following (T+6) adalimumab).

SUBJECTS AND METHODS

Growth and treatment details of 36 children (M: 22) who started adalimumab at a median (10th, 90th) age of 14.7 years (11.3, 16.8) were reviewed.

RESULTS

Of 36 cases, 28 (78%) went into remission. Overall 42% of children showed catch up growth, which was more likely in: (i) those who achieved remission (median change in height SDS (ΔHtSDS) increased from -0.2 (-0.9, 1.0) at T0 to 0.2 (-0.6, 1.6) at T+6, (p=0.007)), (ii) in those who were on immunosuppression ΔHtSDS increased from -0.2 (-0.9, 1.0) at T0 to 0.1 (-0.8, 1.3) at T+6, (p=0.03) and (iii) in those whose indication for using adalimumab therapy was an allergic reaction to infliximab, median ΔHtSDS increased significantly from -0.3 (-0.9, 1.0) at T0 to 0.3 (-0.5, 1.6) at T+6, (p=0.02). Median ΔHtSDS also increased from -0.4 (-0.8, 0.7) at T0 to 0.0 (-0.6, 1.6) at T+6, (p=0.04) in 15 children who were on prednisolone therapy when starting adalimumab.

CONCLUSION

Clinical response to adalimumab therapy is associated with an improvement in linear growth in a proportion of children with CD. Improved growth is more likely in patients entering remission and on immunosuppression but is not solely due to a steroid sparing effect.

A British Society of Paediatric Gastroenterology, Hepatology and Nutrition survey of the effectiveness and safety of adalimumab in children with inflammatory bowel disease

BACKGROUND

Adalimumab is efficacious therapy for adults with Crohn's disease (CD).

AIM

To summarise the United Kingdom and Republic of Ireland paediatric adalimumab experience.

METHODS

British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) members with Inflammatory Bowel Disease (IBD) patients <18 years old commencing adalimumab with at least 4 weeks follow-up. Patient demographics and details of treatment were then collected. Response and remission was assessed using the Paediatric Crohn's Disease Activity Index (PCDAI)/Physicians Global Assessment (PGA).

RESULTS

Seventy-two patients [70 CD, 1 ulcerative colitis (UC), 1 IBD unclassified (IBDU)] from 19 paediatric-centres received adalimumab at a median age of 14.8 (IQR 3.1, range 6.1-17.8) years; 66/70 CD (94%) had previously received infliximab. A dose of 80 mg then 40 mg was used for induction in 41(59%) and 40 mg fortnightly for maintenance in 61 (90%). Remission rates were 24%, 58% and 41% at 1, 6 and 12 months, respectively. Overall 43 (61%) went into remission at some point, with 24 (35%) requiring escalation of therapy. Remission rates were higher in those on concomitant immunosuppression cf. those not on immunosuppression [34/46 (74%) vs. 9/24 (37%), respectively, (χ(2) 8.8, P=0.003)]. There were 15 adverse events (21%) including four (6%) serious adverse events with two sepsis related deaths in patients who were also on immunosuppression and home parenteral nutrition (3% mortality rate).

CONCLUSIONS

Adalimumab is useful in treatment of refractory paediatric patients with a remission rate of 61%. This treatment benefit should be balanced against side effects, including in this study a 3% mortality rate.

Systematic review: medical and nutritional interventions for the management of intestinal failure and its resultant complications in children

BACKGROUND

Intestinal failure (IF) affects a growing number of children due to increasing numbers of preterm infants surviving intestinal resection for necrotising enterocolitis and improving surgical techniques for congenital gut anomalies. Parenteral nutrition (PN) is the mainstay of therapy; enteral nutrition may have trophic effects on the gut.

AIM

To review systematically evidence for the effectiveness of medical and nutritional interventions in the treatment of IF in children.

METHODS

Retrieval of data from studies of patients aged <18 years and receiving >28 days of PN. Outcome measures were improvement in intestinal function, intestinal adaptation, growth, prevention and treatment of IF-associated liver disease, and mortality. Cochrane Database (November 2009), MEDLINE (1950-November 2009) and CINAHL (1982-November 2009) electronic database searches were made using keyword and subject headings (MeSH): IF, Short Bowel Syndrome (SBS), PN and Child. The level of the evidence (EL) was assessed using SIGN (Scottish Intercollegiate Guidelines Network) methodology (http://www.sign.ac.uk).

RESULTS

From 1 607 620 hits, 720 abstracts were reviewed. Thirty-three original articles were included. No studies were of high methodological quality.

CONCLUSIONS

The evidence base for medical and nutritional interventions in paediatric IF is limited and of poor quality. In the absence of randomised-controlled trials, this evidence base can improve through case control and cohort research; and with better multiagency communication, the study of inter-centre differences is possible. Achievable short-term goals would include the study of: optimal ursodeoxycholic usage, novel intralipid formulations, cycled enteral antibiotics, enteral probiotics and new enteral feeding strategies.

Localized cartilage assessment with three-dimensional dGEMRIC in asymptomatic hips with normal morphology and cam deformity

BACKGROUND

Cam deformities cause femoroacetabular impingement and damage the acetabular labral-chondral complex. The aims of this study were to investigate the potential of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) to detect cartilage disease in asymptomatic hips with cam deformities compared with morphologically normal hips, establish whether dGEMRIC could identify advanced disease in hips with positive clinical findings, and establish whether cartilage damage correlated with the severity of the cam deformity.

METHODS

Subjects were recruited from a prospective study of individuals with a family history of osteoarthritis and their spouses who served as control subjects. Their symptoms and impingement test results were recorded. Asymptomatic hips with normal radiographic joint-space width were placed in a subgroup according to the presence of a cam deformity and the impingement test result. dGEMRIC was performed on a 3-T system, studying two regions of interest: the anterosuperior aspect of the acetabular cartilage (T1(acet)) and the total femoral and acetabular cartilage (T1(total)). The ratio T1(acet)/T1(total) gave the relative glycosaminoglycan content in the anterosuperior aspect of the acetabular cartilage. The cohort was placed in subgroups by joint morphology, impingement test status, and genetic predisposition; the mean T1 scores were compared, and the alpha angle and T1 were correlated.

RESULTS

Of thirty-two subjects (mean age, fifty-two years), nineteen had cam deformities. Hips with a cam deformity had reduced acetabular glycosaminoglycan content compared with normal hips (mean T1(acet)/T1(total), 0.949 and 1.093, respectively; p = 0.0008). Hips with a positive impingement test result had global depletion of glycosaminoglycan compared with hips with a negative result (mean T1(total), 625 ms versus 710 ms; p = 0.0152). T1(acet) inversely correlated with the magnitude of the alpha angle (r = -0.483, p = 0.0038), suggesting that the severity of cartilage damage correlates with the magnitude of the cam deformity. All of these differences occurred irrespective of genetic predisposition.

CONCLUSIONS

The dGEMRIC technique can detect cartilage damage in asymptomatic hips with cam deformities and no radiographic evidence of joint space narrowing. This damage correlates with cam deformity severity. Further study of the application of dGEMRIC as an imaging biomarker of early osteoarthritis is justified to validate its prognostic accuracy, identify subjects for clinical trials, and evaluate the effectiveness of surgical procedures.

Diagnosing inertial confinement fusion gamma ray physics (invited)

The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10(-5)γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional γ-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available γ-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV γ-rays produced by inelastic scatter of DT fusion neutrons on (12)C nuclei in the ablating plastic capsule material.

Progress toward the development and testing of source reconstruction methods for NIF neutron imaging

Development of analysis techniques for neutron imaging at the National Ignition Facility is an important and difficult task for the detailed understanding of high-neutron yield inertial confinement fusion implosions. Once developed, these methods must provide accurate images of the hot and cold fuels so that information about the implosion, such as symmetry and areal density, can be extracted. One method under development involves the numerical inversion of the pinhole image using knowledge of neutron transport through the pinhole aperture from Monte Carlo simulations. In this article we present results of source reconstructions based on simulated images that test the methods effectiveness with regard to pinhole misalignment.

Using gamma-ray emission to measure areal density of inertial confinement fusion capsules

Fusion neutrons streaming from a burning inertial confinement fusion capsule generate gamma rays via inelastic nuclear scattering in the ablator of the capsule. The intensity of gamma-ray emission is proportional to the product of the ablator areal density (ρR) and the yield of fusion neutrons, so by detecting the gamma rays we can infer the ablator areal density, provided we also have a measurement of the capsule's total neutron yield. In plastic-shell capsules, for example, (12)C nuclei emit gamma rays at 4.44 MeV after excitation by 14.1 MeV neutrons from D+T fusion. These gamma rays can be measured by a new gamma-ray detector under development. Analysis of predicted signals is in progress, with results to date indicating that the method promises to be useful for diagnosing imploded capsules.

Modeling the National Ignition Facility neutron imaging system

Numerical modeling of the neutron imaging system for the National Ignition Facility (NIF), forward from calculated target neutron emission to a camera image, will guide both the reduction of data and the future development of the system. Located 28 m from target chamber center, the system can produce two images at different neutron energies by gating on neutron arrival time. The brighter image, using neutrons near 14 MeV, reflects the size and symmetry of the implosion "hot spot." A second image in scattered neutrons, 10-12 MeV, reflects the size and symmetry of colder, denser fuel, but with only ∼1%-7% of the neutrons. A misalignment of the pinhole assembly up to ±175 μm is covered by a set of 37 subapertures with different pointings. The model includes the variability of the pinhole point spread function across the field of view. Omega experiments provided absolute calibration, scintillator spatial broadening, and the level of residual light in the down-scattered image from the primary neutrons. Application of the model to light decay measurements of EJ399, BC422, BCF99-55, Xylene, DPAC-30, and Liquid A suggests that DPAC-30 and Liquid A would be preferred over the BCF99-55 scintillator chosen for the first NIF system, if they could be fabricated into detectors with sufficient resolution.

Accuracy of simple clinical and epidemiological definitions of childhood obesity: systematic review and evidence appraisal

The optimum means of defining obesity in children is unclear, creating variation in practice, and hindering obesity surveillance, prevention and treatment. This study aimed to review evidence on the use of body mass index (BMI) and waist circumference for diagnosis of high body fat content and adverse cardiometabolic risk factors in children and adolescents. A systematic literature review was carried out and evidence appraised using the Quality Assessment of Studies of Diagnostic Accuracy in Systematic Reviews method. Literature searching began following the last systematic review of this topic (end 2001) and collected evidence in MEDLINE and EMBASE in 0- to 18-year-olds that compared the accuracy of BMI vs. waist circumference and compared BMI interpreted relative to national reference data vs. BMI interpreted relative to Cole/International Obesity Task Force international reference data. Ten studies compared diagnostic accuracy of BMI vs. waist circumference: they reported no improved identification of adverse cardiometabolic risk profiles from waist circumference over that provided by high BMI. Eight studies compared BMI with national reference data vs. the international approach: 5/8 found significantly poorer accuracy (lower sensitivity) using BMI with the international approach; 3/8 found similar sensitivity; in 7/7 studies that compared specificity this was similar. In conclusion, the present review provides no compelling evidence for use of either high waist circumference or BMI interpreted using the International Obesity Task Force approach in preference to the use of national BMI percentiles for the identification of children and adolescents with excess fatness and adverse cardiometabolic risk profile.

Magnetic resonance follow-through imaging for evaluation of disease activity in ileal Crohn's disease: an observational, retrospective cohort study

BACKGROUND

Magnetic resonance follow-through (MRFT) is a new cross-sectional imaging modality with the potential to accurately stage ileal Crohn's disease (CD), while avoiding ionizing radiation and the discomfort associated with enteroclysis. We aimed to assess the reliability of this technique in assessing the extent and activity of ileal CD, and to assess its influence on subsequent management.

METHODS

Out of a total of 342 patients undergoing MRFT between 2004 and 2008, 221 were performed in 191 patients with confirmed CD. Case notes were reviewed in detail with documentation of all investigations pre- and post-MRFT. Agreement between inflammatory markers, histopathology, and MRFT findings was determined.

RESULTS

Overall, 116/221 (52.5%) of MRFTs showed active ileal CD, and 76/221 (34.4%) quiescent CD, while 29/221 (13.1%) were suboptimal. Overall, 66 strictures and 18 fistulae were identified. There was substantial agreement between active ileal CD on MRFT and histopathology (n = 59; kappa = 0.66; P = 0.0006; sensitivity 85.1%, specificity 85.7%) and fecal calprotectin (n = 14; kappa = 0.72; P = 0.047), while C-reactive protein (CRP) showed moderate agreement (n = 107; kappa = 0.402; P = 0.00028). Management was influenced by MRFT reports following active (52/84, 62% treated medically) or quiescent (48/62, 77.4% managed conservatively) disease. Fibrotic strictures were predominantly treated surgically (7/14, 50%). In all, 13/32 (40.6%) patients with inflammatory ileal strictures required surgery, mostly due to steroid-resistant disease. Overall, 75 MR findings were documented in 221 MRFTs, including 1 renal cancer.

CONCLUSIONS

MRFT provides accurate information on ileal CD activity, with close agreement to inflammatory markers and histopathology. It represents a substantial advance in the staging of CD, while avoiding painful enteroclysis and radiation exposure in young patients.

Regionally acquired intestinal failure data suggest an underestimate in national service requirements

OBJECTIVES, SETTING AND PATIENTS: With complete case referral for prolonged parenteral nutrition (PN) beyond term equivalent, serving a stable population of 1.25 million people, we describe the long-term outcome and survival of patients referred to an intestinal failure (IF) nutrition support team over the first 8 years of existence at a regional paediatric centre, and extrapolate to potential numbers of national home parenteral nutrition (HPN) cases and intestinal transplantation data.

DESIGN AND OUTCOME MEASURES

Retrospective analysis detailing patient demographics, interventions, use of HPN, occurrence of intestinal failure-associated liver disease (IFALD), and outcomes of enteral adaptation, survival, and referral for and receipt of organ transplantation.

RESULTS

23 patients were referred over 8 years, 20 being PN dependent within the neonatal period. Diagnoses included short bowel syndrome (SBS) (18), neuromuscular abnormalities (4) and congenital enterocyte disorder (1). 12 696 days of PN were delivered with 314 confirmed episodes of sepsis at a median of 12 episodes per patient. 144 central venous catheters (CVCs) were required at a median of four per patient. IFALD occurred in 17 (73%) patients, with 10 (44%) referred for transplant assessment. Thirteen (56%) children received HPN. Overall mortality was 44%. A significant predictor for survival in the SBS group was residual bowel >40 cm (82% vs 28%, p = 0.049).

CONCLUSIONS

Survival for IF at 56% was lower than reported from non-UK supra-regional centres, and nationally collected data, possibly reflecting pre-selected referral populations. Data from regional centres with complete ascertainment may be important both when counselling parents and when planning regional and national HPN and IF specialist services.

Filaggrin loss-of-function variants are associated with atopic comorbidity in pediatric inflammatory bowel disease

BACKGROUND

Pediatric inflammatory bowel disease (IBD) has a high prevalence of coexistent atopy. Filaggrin (FLG) loss-of-function variants (null-alleles) are associated with eczema and asthma in association with eczema. The aim was to assess the contribution of FLG null-alleles to pediatric IBD susceptibility and to coexistent atopy (eczema, asthma, allergic rhinitis, or food allergy).

METHODS

FLG variants (R501X and 2282del4) were genotyped in 403 children with IBD, 683 parents, and 996 population controls.

RESULTS

In all, 11% of IBD patients carried at least 1 FLG null-allele compared to 11% of population controls (P > 0.4). Carriage of 1 or more null-alleles in patients with atopy (present in 52% of IBD patients) differed from IBD patients without atopy (14% versus 6%, P = 0.01; odds ratio [OR] 2.4, 95% confidence interval [CI] 1.2-5.1). The effect of FLG null-alleles was strongest for eczema (19% versus 7%, P = 0.0003; OR 3.3, 95% CI 1.7-6.6) and food allergy (28% versus 8%, P = 0.0001; OR 4.5, 95% CI 2.0-10.0). The presence of more than 1 atopic disease tended to increase the associated OR: eczema + asthma (23% versus 7%, P = 0.001; OR 3.9, 95% CI 1.6-9.1), eczema + asthma + allergic rhinitis (29% versus 7%, P = 0.0006; OR 5.4, 95% CI 1.9-15.4) and eczema + asthma + allergic rhinitis + food allergy (45% versus 6%, P < 10(-4); OR 12.2, 95% CI 3.2-46.3). Logistic regression analysis of IBD cases confirmed the association of carriage of an FLG null-allele with atopy (P = 0.01; OR 2.4, 95% CI 1.2-5.1) and co-occurrence of different forms of atopy (P = 0.003; OR 3.5, 95% CI 1.5-8.1).

CONCLUSIONS

Filaggrin null-alleles have no effect on IBD susceptibility but contribute to coexistent eczema and food allergy.

Efficacy and complications of adalimumab treatment for medically-refractory Crohn's disease: analysis of nationwide experience in Scotland (2004-2008)

BACKGROUND

Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).

AIMS

To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.

METHODS

We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004-2008).

RESULTS

A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).

CONCLUSIONS

Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.

Efficacy and complications of adalimumab treatment for medically-refractory Crohn's disease: analysis of nationwide experience in Scotland (2004-2008)

BACKGROUND

Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).

AIMS

To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.

METHODS

We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004-2008).

RESULTS

A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).

CONCLUSIONS

Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.

The safety profile of anti-tumour necrosis factor therapy in inflammatory bowel disease in clinical practice: analysis of 620 patient-years follow-up

BACKGROUND

Anti-TNF agents are now widely used in Crohn's disease (CD), and in ulcerative colitis (UC).

AIM

To review the safety profile of anti-TNF agents in all patients treated with infliximab in Edinburgh from 1999 to 2007.

METHODS

Complete data were available on 202/207 patients comprising 157 CD, 42 UC and three coeliac disease. Median follow-up was 2.4 years (1.0-4.9) with a total of 620 patient-years follow-up. About 19.1% of CD patients were subsequently treated with adalimumab.

RESULTS

Seven deaths (3.3%) occurred in follow-up; only one death was <1 year post-infliximab (at day 72, from lung cancer). A total of six malignancies (three haematological, three bronchogenic) and six cases of suspected demyelination (three with confirmed neurological disease) were reported. In the 90 days following infliximab, 95 adverse events (36 serious) occurred in 58/202 (28.7%) patients. In all, 42/202 (20.8%) had an infectious event (22 serious) and 27/202 (13.4%) of patients had an infusion reaction: 19 acute (four serious) and eight delayed (three serious).

CONCLUSIONS

Serious infections, malignancies and neurological disease complicate anti-TNF use in clinical practice. Although evidence for causality is unclear, potential mechanisms and predisposing factors need to be explored. In individual patients, the risk/benefit analysis needs to be carefully assessed and discussed prior to commencement of therapy.

A spatially resolved ion temperature diagnostic for the National Ignition Facility

The concepts and initial development efforts for a spatially resolved ion temperature diagnostic are described. The diagnostic is intended for Inertial Confinement Fusion experiments at the National Ignition Facility and is an integration of neutron aperture imaging and ion temperature techniques. The neutron imaging technique is extended by recording tomographic projections of the radiation-to-light converter on a streak camera. The streak record is used to calculate images at multiple times during the arrival of the thermally broadened 14.1 MeV neutron flux. The resulting set of images is used to determine the spatially resolved ion temperature.

First measurements of the absolute neutron spectrum using the magnetic recoil spectrometer at OMEGA (invited)

A neutron spectrometer, called a magnetic recoil spectrometer (MRS), has been built and implemented at the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] for absolute measurements of the neutron spectrum in the range of 6-30 MeV, from which fuel areal density (rhoR), ion temperature (T(i)), and yield (Y(n)) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring rhoR at the National Ignition Facility (NIF) [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles to ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the research and development and instrument optimization of the MRS at OMEGA are directly applicable to the MRS at the NIF, a description of the design and characterization of the MRS on the NIF is discussed as well.

Diagnosing ignition with DT reaction history

A full range DT reaction history of an ignition capsule, from 10(9) to 10(20) neutronsns, offers the opportunity to diagnose fuel conditions hundreds of picoseconds before and during burn. The burn history begins with a sharp rise when the first shock reaches the center of the capsule. The level of this jump reflects the combined shock strength and the adiabat of DT fuel. Changes to the four laser pulses driving the capsule implosion which are large enough to degrade the yield make measurable changes to the reaction history. Low mode asymmetries grow during convergence but change the reaction history during the final approximately 100 ps. High mode asymmetry or turbulence mixing affects only the reaction history within approximately 50 ps of peak burn rate. A capsule with a tritium fuel layer containing a small amount of deuterium (approximately 1%) creates a reaction history similar to the ignition capsule, but without the final ignition burn. A combination of gas Cerenkov detectors and the neutron temporal diagnostic could be capable of diagnosing the full history of ignition and tritium rich capsules.

Use of d-3He proton spectroscopy as a diagnostic of shell rho r in capsule implosion experiments with approximately 0.2 NIF scale high temperature Hohlraums at Omega

We present the calculations and preliminary results from experiments on the Omega laser facility using d-(3)He filled plastic capsule implosions in gold Hohlraums. These experiments aim to develop a technique to measure shell rho r and capsule unablated mass with proton spectroscopy and will be applied to future National Ignition Facility (NIF) experiments with ignition scale capsules. The Omega Hohlraums are 1900 microm length x 1200 microm diameter and have a 70% laser entrance hole. This is approximately a 0.2 NIF scale ignition Hohlraum and reaches temperatures of 265-275 eV similar to those during the peak of the NIF drive. These capsules can be used as a diagnostic of shell rho r, since the d-(3)He gas fill produces 14.7 MeV protons in the implosion, which escape through the shell and produce a proton spectrum that depends on the integrated rho r of the remaining shell mass. The neutron yield, proton yield, and spectra change with capsule shell thickness as the unablated mass or remaining capsule rho r changes. Proton stopping models are used to infer shell unablated mass and shell rho r from the proton spectra measured with different filter thicknesses. The experiment is well modeled with respect to Hohlraum energetics, neutron yields, and x-ray imploded core image size, but there are discrepancies between the observed and simulated proton spectra.

Can extra-articular strains be used to measure facet contact forces in the lumbar spine? An in-vitro biomechanical study

Experimental measurement of the load-bearing patterns of the facet joints in the lumbar spine remains a challenge, thereby limiting the assessment of facet joint function under various surgical conditions and the validation of computational models. The extra-articular strain (EAS) technique, a non-invasive measurement of the contact load, has been used for unilateral facet joints but does not incorporate strain coupling, i.e. ipsilateral EASs due to forces on the contralateral facet joint. The objectives of the present study were to establish a bilateral model for facet contact force measurement using the EAS technique and to determine its effectiveness in measuring these facet joint contact forces during three-dimensional flexibility tests in the lumbar spine. Specific goals were to assess the accuracy and repeatability of the technique and to assess the effect of soft-tissue artefacts.

In the accuracy and repeatability tests, ten uniaxial strain gauges were bonded to the external surface of the inferior facets of L3 of ten fresh lumbar spine specimens. Two pressure-sensitive sensors (Tekscan) were inserted into the joints after the capsules were cut. Facet contact forces were measured with the EAS and Tekscan techniques for each specimen in flexion, extension, axial rotation, and lateral bending under a ±7.5 N m pure moment. Four of the ten specimens were tested five times in axial rotation and extension for repeatability. These same specimens were disarticulated and known forces were applied across the facet joint using a manual probe (direct accuracy) and a materials-testing system (disarticulated accuracy). In soft-tissue artefact tests, a separate set of six lumbar spine specimens was used to document the virtual facet joint contact forces during a flexibility test following removal of the superior facet processes.

Linear strain coupling was observed in all specimens. The average peak facet joint contact forces during flexibility testing was greatest in axial rotation (71±25 N), followed by extension (27±35 N) and lateral bending (25±28 N), and they were most repeatable in axial rotation (coefficient of variation, 5 per cent). The EAS accuracy was about 20 per cent in the direct accuracy assessment and about 30 per cent in the disarticulated accuracy test. The latter was very similar to the Tekscan accuracy in the same test. Virtual facet loads (r.m.s.) were small in axial rotation (12 N) and lateral bending (20 N), but relatively large in flexion (34 N) and extension (35 N).

The results suggested that the bilateral EAS model could be used to determine the facet joint contact forces in axial rotation but may result in considerable error in flexion, extension, and lateral bending.

Autophagy gene ATG16L1 influences susceptibility and disease location but not childhood-onset in Crohn's disease in Northern Europe

BACKGROUND

The rs2241880A/G variant of the ATG16L1 gene has been associated with susceptibility to ileal Crohn's disease (CD) in adults. Our aim was to assess whether germline variation of ATG16L1 acts as an independent determinant of susceptibility to childhood-onset CD in the high-incidence Scottish population.

METHODS

In all, 2195 subjects (361 children (inflammatory bowel disease [IBD] diagnosis <17 years), their parents (n = 634), 855 adult IBD patients, and 345 controls were genotyped. Case-control analysis was powered to detect effect sizes with an odds ratio (OR) >1.39 in pediatric CD. Case-control analysis, transmission disequilibrium testing (TDT), analysis of variance (ANOVA) of growth parameter z-scores, Kruskal-Wallis test (age at diagnosis), and multifactorial genotype-phenotype analysis (Montreal classification) were performed. 7.8% of pediatric CD patients and 37.2% of adult CD patients had pure ileal disease.

RESULTS

We confirmed the association of the rs2241880G-allele with adult-onset CD (60.7% versus controls 53.9%, P = 0.01, OR 1.32, 95% confidence interval [CI] 1.07-1.63) in contrast to childhood-onset CD (54.1% versus controls, P = 0.95, OR 1.01, 95% CI 0.80-1.26). TDT analysis was negative. Genotype-phenotype analysis demonstrated an association of pure ileal disease with the rs2241880G-allele (P = 0.02, OR 1.34, 95% CI 1.03-1.74). Using binary logistic regression analysis we confirmed the effect of rs2241880 genotype (GG) on ileal disease versus colonic disease (P = 0.03, OR 2.43, 95% CI 1.05-5.65). ATG16L1 genotype did not influence age at CD diagnosis. ANOVA of z-scores of height, weight, and body mass index (BMI) at CD diagnosis in children showed no association with genotype.

CONCLUSIONS

The ATG16L1 variant is associated with susceptibility to adult CD in Scotland, but not early-onset disease. These contrasting effects are primarily driven by differences in disease location between early-onset and adult-onset disease.

Solid waste management in Abuja, Nigeria

The new city of Abuja provided an opportunity to avoid some of the environmental problems associated with other major cities in Africa. The current status of solid waste management in Abuja has been reviewed and recommendations for improvements are made. The existing solid waste management system is affected by unfavourable economic, institutional, legislative, technical and operational constraints. A reliable waste collection service is needed and waste collection vehicles need to be appropriate to local conditions. More vehicles are required to cope with increasing waste generation. Wastes need to be sorted at source as much as possible, to reduce the amount requiring disposal. Co-operation among communities, the informal sector, the formal waste collectors and the authorities is necessary if recycling rates are to increase. Markets for recycled materials need to be encouraged. Despite recent improvements in the operation of the existing dumpsite, a properly sited engineered landfill should be constructed with operation contracted to the private sector. Wastes dumped along roads, underneath bridges, in culverts and in drainage channels need to be cleared. Small-scale waste composting plants could promote employment, income generation and poverty alleviation. Enforcement of waste management legislation and a proper policy and planning framework for waste management are required. Unauthorized use of land must be controlled by enforcing relevant clauses in development guidelines. Accurate population data is necessary so that waste management systems and infrastructure can be properly planned. Funding and affordability remain major constraints and challenges.

Polyethylene glycol 3350 plus electrolytes for chronic constipation in children: a double blind, placebo controlled, crossover study

OBJECTIVES

To assess the efficacy and safety of polyethylene glycol 3350 plus electrolytes (PEG+E) for the treatment of chronic constipation in children.

DESIGN

Randomised, double blind, placebo controlled crossover trial, with two 2-week treatment periods separated by a 2-week placebo washout.

SETTING

Six UK paediatric departments.

PARTICIPANTS

51 children (29 girls, 22 boys) aged 24 months to 11 years with chronic constipation (lasting > or =3 months), defined as < or =2 complete bowel movements per week and one of the following: pain on defaecation on 25% of days; > or =25% of bowel movements with straining; > or =25% of bowel movements with hard/lumpy stools. 47 children completed the double blind treatment.

MAIN OUTCOME MEASURES

Number of complete defaecations per week (primary efficacy variable), total number of complete and incomplete defaecations per week, pain on defaecation, straining on defaecation, faecal incontinence, stool consistency, global assessment of treatment, adverse events and physical examination.

RESULTS

The mean number of complete defaecations per week was significantly higher for children on PEG+E than on placebo (3.12 (SD 2.05) v 1.45 (SD 1.20), respectively; p<0.001). Further significant differences in favour of PEG+E were observed for total number of defaecations per week (p = 0.003), pain on defaecation (p = 0.041), straining on defaecation (p<0.001), stool consistency (p<0.001) and percentage of hard stools (p = 0.001). Treatment related adverse events (all mild or moderate) occurred in similar numbers of children on PEG+E (41%) and placebo during treatment (45%).

CONCLUSIONS

PEG+E is significantly more effective than placebo, and appears to be safe and well tolerated in the treatment of chronic constipation in children.