A150 MODERATE AGREEMENT IN ENDOSCOPIC DISEASE SCORING OF PEDIATRIC EOSINOPHILIC ESOPHAGITIS AMONG PEDIATRIC GASTROENTEROLOGISTS IN CANADA

Background

Endoscopy is an important tool in assessing the severity of gastrointestinal diseases including Eosinophilic Esophagitis (EoE). Agreement regarding endoscopy outcomes is important when using tools such as the Endoscopic Reference Score for EoE (EREFS).

Purpose

Our goal was to determine interrater and intrarater agreement of EREFS among Canadian pediatric gastroenterologists.

Method

Survey-based study of interrater and intrarater reliability amongst pediatric gastroenterologists with interest in pediatric EoE. Participants were sourced from the Canadian Pediatric EoE Network. Participants were asked how many years of training they’ve had with endoscopy for pediatric EoE and their comfort in disease scoring for pediatric EoE. Pediatric EoE cases were identified from the pediatric EoE registry at the Stollery Children’s Hospital with an endoscopic video associated with each case. Participants were asked to score each video using the EREFS questionnaire for the proximal, middle and distal segments of the esophagus. 15 endoscopic videos were evaluated, with 3 cases provided each week over a period of 5 weeks. Additional data included ratings of the video quality and endoscopy quality. Of 15 cases, 12 were unique cases, distributed evenly in severity between no active disease to severe disease. 3 cases were repeated to assess intrarater reliability. The maximum grade of the proximal, middle and distal segments of the esophagus for each component endoscopic finding (edema, rings, exudates, furrows, strictures) were used for reliability calculations. Fleiss Kappa was calculated for all EREFS items and for each component endoscopic finding. Cohen’s Kappa was calculated to assess intrarater reliability.

Result(s)

Fifteen participants were recruited for the study. The participants had a median of 12 years (IQR: 7, 19) of clinical experience in endoscopy for pediatric EoE. The majority of participants were “comfortable” (i.e., 4 on 5-point scale) with EREFS scoring for pediatric EoE. Fleiss Kappa for all EREFS items was 0.481. For each component endoscopic finding (edema, rings, exudates, furrows, strictures), Fleiss Kappa was 0.365, 0.293, 0.548, 0.263, 0.445 respectively. Cohen’s Kappa had a median of 0.620 (IQR: 0.593, 0.704). The majority of raters rated video quality and endoscopy quality as “good” (i.e., 4 on 5-point scale).

Conclusion(s)

There is moderate interrater reliability in EREFS scoring for pediatric EoE. Interrater reliability was between fair to moderate for each component endoscopic finding. Intrarater reliability was good. This study shows there is room for improvement in disease scoring for pediatric EoE. This could be in the form of additional training, expert-defined conventions, or centralized reading which have reduced variability in endoscopic reporting for adult GI disease in past studies and could be used in a follow-up study to attempt to improve agreement. Additionally, incorporating EREFS into routine clinical practice may increase agreement amongst endoscopists.

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None

Disclosure of Interest

None Declared

A143 PEDIATRIC EOSINOPHILIC ESOPHAGITIS IN CANADA: A MULTI-CENTER COHORT WITH FOCUS ON THE STRICTURING PHENOTYPE

Background

Eosinophilic esophagitis (EoE) is a chronic eosinophil-predominant esophageal inflammatory condition, and is now recognized as one of the most common organic causes of dysphagia in pediatrics. While fibrostenotic esophageal strictures are a common complication of adult EoE, characterization of the stricturing phenotype in pediatric EoE remains at an early stage.

Purpose

Describe the Canadian pediatric EoE experience, with focus on the stricturing phenotype.

Method

New pediatric EoE diagnoses from 2015-2018 were retrospectively identified in Vancouver (BC), Northern Alberta (AB), Hamilton (ON) and Nova Scotia (NS). Incidence rates were calculated using 2016 Federal census data. Clinical, endoscopic and histologic data were gathered for each patient’s initial clinical encounter and for any esophagogastroduodenoscopies (EGD) until the end of the follow-up period (fall 2019).

Result(s)

332 new EoE cases were identified during the study period across all 4 sites. The incidence of EoE in patients less than 15 years old was 9.1 (AB), 6.5 (NS), 3.1 (BC) and 5.4 (combined) per 100,000 person-years. Incidence was not calculated for Hamilton due to risk of ascertainment bias given their catchment area overlaps with multiple other centers. Of identified cases, 40 (12.0%) had endoscopically-identified esophageal strictures at diagnosis or during the follow-up period, with a subset of 11 (3.3%) of these patients undergoing mechanical esophageal dilation. Another 11 (3.3%) patients had more subtle signs of esophageal narrowing (ex. mucosal rents), while the majority had no evidence of esophageal narrowing (281, 84.6%). The median age at diagnosis was higher in the cohort with strictures (12.4 years, IQR 8.9-14.1) than those without (10.3 years, IQR 6.1-13.6) but with wide IQR's. A similar trend was seen for the median duration of symptoms at diagnosis (1.5 years, IQR 0.5-3 versus 1.0 years, IQR 0.6-2.8). Patient reported food bolus impaction (OR 9.8, 95% CI 3.9-19.9) and dysphagia (OR 3.3, 95% CI 1.3-7.8) were associated with stricturing disease, with other symptoms less clearly linked. Trachealization was the endoscopic finding most closely associated with esophageal strictures (OR 5.7, 95% CI 2.8-11.5). Esophageal stricture(s) were noted on 72 EGDs, including 27 endoscopic esophageal dilations, but excluding 10 esophageal dilations by interventional radiology. Of the 65 EGDs done in follow-up of a known esophageal stricture (see Table), 4 of 31 had resolution of this finding post mechanical dilation, and 19 of 39 had resolution of the stricture after initiation of new medical or dietary treatments (without dilation).

Conclusion(s)

EoE is common in Canadian children, with esophageal strictures within a few years of diagnosis in 12% of cases. Interestingly, a large portion of strictures resolved without mechanical dilation, which seems to point away from fibrosis as the primary driver of esophageal strictures in this patient population.

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CAG, Other

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Women and Children's Health Research Institute

Disclosure of Interest

None Declared

A14 WIDE VARIATION IN CLINICAL MANAGEMENT OF PAEDIATRIC EOSINOPHILIC ESOPHAGITIS: A CANADIAN EXPERIENCE

Background

Eosinophilic esophagitis (EoE) is a chronic disorder treated by food elimination diet (FED), topical steroids and/or proton-pump inhibitors (PPI). Serial endoscopies and biopsies assess response to therapy. EoE management has evolved as guidelines are updated.

Aims

To identify practice variation among Canadian paediatric gastroenterologists (PG) who care for children with EoE.

Methods

An online survey using REDCap about decision-making in children with EoE was distributed to PG in Canada in November 2020.

Results

62 PG completed the survey (response rate 69%, 62/94). The majority work in academic centres (92%). 3 centers indicated an accrual of >50 new patients per year; 9/16 centres have >100 patients in follow-up. An EoE Clinic is present in 5 centres.

Diagnosis: Familiarity with the 2018 AGREE and 2020 AGA EoE guidelines was found to be 57% and 67% respectively. Criteria required to diagnose EoE according to current guidelines were correctly indicated by 42% of PG. (Figure 1).

Endoscopy: The majority of PG (95%) adhere to guidelines in terms of required number and location of biopsies for the initial diagnosis. Ideal timing of repeat endoscopy after change in therapy in patients who are not in histological remission was 8–12 weeks by 67% of PG, timing in stable patients on maintenance therapy varied (33% only if patient is symptomatic). 25% used the EREFS Score in reporting endoscopic findings.

Therapy: Improvement of symptoms was the highest ranked goal (64%), followed by remission of histologic findings (30%). A treatment algorithm was in place in 4 centers. The majority routinely assess adherence to therapy (73%) and consult a dietitian for FED (77%). Most (87%) do not consult an allergist for initial management. Preferred choices of 1st-line therapy varied among PG (Figure 2). When FED was selected, 32% of PG started with 1 food, 32% started with 2 foods, most frequently excluding dairy, followed by wheat. 14 (26%) start with ≥6 FED. Prescription of budesonide slurry was consistent among PG with doses of 1 and 2 mg/day in children <10 and >10 years, respectively.

Conclusions

The is the first Canadian study to assess the variation in management of children with EoE by PG. Overall, PG demonstrated good adherence to the guidelines in terms of initial diagnosis, but differences in maintenance therapy choice and timing of endoscopies. The results highlight a need for standardized management algorithms to deliver uniform care to this growing group. Grounding these guidelines in evidence will warrant a significant investment in further paediatric EoE research.

Funding Agencies

None

A196 INCIDENCE OF PEDIATRIC EOSINOPHILIC ESOPHAGITIS IN EDMONTON ZONE AND RISK OF STRICTURING AT DIAGNOSIS

Background

Eosinophilic esophagitis (EoE) is a common cause of esophageal dysfunction in children. A subset of children have a more severe phenotype of EoE, complicated by esophageal stricturing. Limited work has been done to characterize this phenotype.

Aims

To determine the incidence of EoE, and the frequency of esophageal stricturing in pediatric EoE.

Methods

We retrospectively identified all new cases of EoE at the Stollery Children’s Hospital from 2015–2018 using esophageal biopsy reports for the province of Alberta (CoPath database), EoE clinic lists and an OR database for esophageal dilatation at the Stollery. Electronic medical records (EMR) were reviewed to confirm EoE diagnosis. For each confirmed case, clinical data was captured from the outpatient EMR and gastroscopy/pathology reports. A review of peri-endoscopy OR/nursing charts was performed on a subset of patients (n=75) to capture scope adverse event. Statistics Canada 2016 census data was used to calculate incidence rates.

Results

185 new cases of EoE were diagnosed at our center during the study period (see table). For patients < 15 years old living in Edmonton zone (n=73), the incidence over the 4 years was 11.1 cases per 100,000 person years {8.7 (0–4 year-old), 7.6 (5–9 year old), and 18.1 (10–14 year old)}. There was limited variation in incidence in the 4 years (9.1–12.1 per 100,000 person years). 8 of 185 (4%) patients had endoscopically confirmed esophageal strictures, 4 of which required mechanical dilation (mean 3.75 dilations per patient, range 1–6). 11/185 (5.9%) patients had more subtle signs of esophageal narrowing, but no strictures. No perforations or episodes of significant bleeding were reported in peri-endoscopy charts reviewed for 239 gastroscopes, including 16 dilations. Pain was reported after 15% of all scopes, including 50% of the 28 scopes with strictures and 63% of the 16 scopes involving dilations.

Conclusions

Edmonton zone has one of the highest incidences of EoE reported in children. In this cohort, 4% had esophageal stricture (half required dilatation) and 5.9% had more subtle narrowing. Patients with strictures were older, had more frequent food impaction and longer duration of symptoms (Table). This data will be included in an ongoing multicenter case-control study across Canada.

Funding Agencies

CAGWomen and Children’s Health Research Institute (Univ. Alberta)

Anthropologists Respond to The Lancet EAT Commission

The Lancet Commissions are widely known as aspirational pieces, providing the mechanisms for consortia and networks of researchers to organize, collate, interrogate and publish around a range of subjects. Although the Commissions are predominantly led by biomedical scientists and cognate public health professionals, many address social science questions and involve social science expertise. Medical anthropologist David Napier was lead author of the Lancet Commission on Culture and Health (2014), for example, and all commissions on global health (https://www.thelancet.com/global-health/commissions) address questions of social structure, everyday life, the social determinants of health, and global inequalities.

Validity of the Titmus Vision Screener: A Comparison with the Snellen Chart

Given limited knowledge regarding validity of the Titmus vision screener, we sought to compare visual acuity measurements obtained from the Titmus with that from the Snellen chart and assess the validity properties of the Titmus as a screening instrument to detect vision impairment. Visual acuity was measured in 150 participants recruited from an academic ophthalmology practice, using the Snellen chart as well as the Titmus vision screener. Visual acuities from the Titmus and Snellen were compared and validity of the Titmus vision screener was assessed by computing sensitivity and specificity. Using Snellen visual acuity as the reference standard, the sensitivity of the Titmus vision screener to detect vision impairment, defined as visual acuity worse than 20/40, was 92% (95% CI (72.5, 98.6)) and the specificity was 64% (95% CI (57.9, 70.1)). Comparisons of the precise visual acuity level revealed poor agreement between the two methods (weighted Kappa: 0.15, 95% CI (0.08, 0.21)). Visual acuities obtained from the Titmus were, on average, two lines worse than Snellen visual acuities. ((logMAR Snellen – logMAR Titmus) = - 0.19 ± 0.29, 95% confidence interval (CI) (-0.23, -0.16)). Titmus vision screener is a sensitive tool to detect visual impairment. However high false positive results and poor agreement with Snellen limits its widespread use in clinical applications.

Abstract P2-11-17: Pilot Study to Evaluate a Home-based Exercise and Weight Loss Intervention on Cardiopulmonary Fitness and Markers of Breast Cancer Risk in Postmenopausal Breast Cancer Survivors

Background: BrCa survivors have an estimated 4-fold increase in risk for developing cardiovascular disease compared to women never treated for breast cancer and a nearly 3-fold increase in breast cancer mortality in women with an exercise capacity (VO2max) less than 28mL kg−1 min−1. Cardiac events are the second most common cause of death in long-term breast cancer (BrCa) survivors.

Purpose: We conducted a study to investigate the effects of standard exercise or structured exercise on targeted cardiovascular outcomes during a home-based diet and exercise intervention for breast cancer survivors.

Method: Cross-sectional within- and between-group design. A total of 19 breast cancer survivors, average age of 52.6+/−9.3, were enrolled in the study. A convenient sample was enrolled into two exercise groups receiving either: standard (150 minutes per week of usual care (exercise without instruction) cardiovascular exercise + resistance training) or structured (150 minutes per week of gradual increased intensity cardiovascular exercise + resistance training) exercise instruction along with a group based behavioral weight loss intervention. All participants underwent baseline and 17 week assessments including maximal exercise testing (VO2max and minutes on the treadmill), measurements of body composition (weight, BMI, % body fat), and assessment of quality of life.

Results: We report on the 16 participants who completed the baseline and 17 week assessments (9 = Standard Exercise Group; 7 = Structured Exercise Group). The structured exercise group exhibited significantly greater improvements in measures of cardiorespiratory fitness: VO2max (p = 0.05) and duration on treadmill (p = 0.02). No significant differences were noted for all other cardiorespiratory fitness testing outcomes. Significant improvements from baseline to 17 weeks were seen across both groups for all measures of body composition. Lean body mass did not significantly change from baseline to 17 weeks in both groups. There were no significant between group differences for change in body composition.

Perceived Muscle Soreness in Recreational Female Runners

The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at -15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR.

RESULTS

Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1-100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR.

CONCLUSION

Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS.

Neutrophil elastase and cathepsin G protein and messenger RNA expression in bone marrow from a patient with Chediak-Higashi syndrome

Aims-To determine whether neutrophil elastase and cathepsin G are expressed, at transcriptional or translational levels, in the bone marrow from a patient with Chediak-Higashi syndrome.Methods-Blood neutrophils were isolated from three patients with Chediak-Higashi disease and bone marrow was collected from one. Cell lysates were analysed for neutrophil elastase and cathepsin G activity by enzyme linked immunosorbent assay and western immunoblotting. Northern blotting was used to detect messenger RNA (mRNA) for cathepsin G, elastase and beta-actin in bone marrow extracts, and immunohistochemistry was used to localise the enzymes in marrow myeloid cells.Results-Elastase and cathepsin G were not detected in blood neutrophils from the patients with Chediak-Higashi disease, but were present in bone marrow cells, although immunohistochemistry showed they were not within cytoplasmic granules. The concentrations of elastase and cathepsin G in Chediak-Higashi bone marrow were about 25 and 15%, respectively, of those in normal marrow. Quantitative scanning of northern blots showed that elastase and cathepsin G mRNA, corrected for beta-actin mRNA, were expressed equally in normal marrow.Conclusions-Transcription of elastase and cathepsin G mRNA in promyelocytes of patients with Chediak-Higashi disease is normal, but the protein products are deficient in these cells and absent in mature neutrophils. This suggests that the translated proteins are not packaged into azurophil granules but are degaded or secreted from the cells.

A phase I evaluation of oral CI-1033 in combination with paclitaxel and carboplatin as first-line chemotherapy in patients with advanced non-small cell lung cancer

PURPOSE

In the United States, lung cancer represents the third most common cancer, causing the most cancer-related deaths, with treatment advances minimally affecting 5-year survivals. Erb-B family receptor elevations are found in many non-small cell lung cancer tumors, making this receptor family a drug target with potential for improving survival.

DESIGN

Chemotherapy-naive patients with advanced non-small cell lung cancer were enrolled who had at least one elevated tumor-expressed member of the erb-B family receptors. This dose-finding, multicenter, open-label, phase I study combined chemotherapy with paclitaxel and carboplatin, adding the tyrosine kinase inhibitor CI-1033. Patients were evaluated for toxicity, response, survival, and pharmacokinetics.

RESULTS

All 39 patients enrolled were assessable for safety and efficacy. Dose-limiting toxicities (diarrhea, rash, asthenia, and hypotension) occurred at the 200- and 150-mg dose levels of CI-1033; the maximum tolerated dose was 100 mg. Most toxicities were mild to moderate. Pharmacokinetics studies showed that paclitaxel levels were unaffected by CI-1033 and that CI-1033 plasma concentrations were consistent with historical controls. Ten patients (25.6%) achieved partial responses and another 11 (28.2%) had stable disease. In the recommended phase II dose cohort (n = 23), six patients (26%) had partial responses and six (26%) had stable disease. Median survival time was 12.4 months; median progression-free survival was 5.1 months.

CONCLUSION

Paclitaxel-carboplatin, combined with CI-1033 at 100 mg/day, was safe and well tolerated. Efficacy and survival results were comparable to those of similar studies in advanced non-small cell lung cancer and therefore warrant additional phase II testing.

Nicotinamide Reverses Neurological and Neurovascular Deficits in Streptozotocin Diabetic Rats

In diabetes, activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) is an important effector of oxidative-nitrosative injury, which contributes to the development of experimental diabetic peripheral neuropathy (DPN). However, the potential toxicity of complete PARP inhibition necessitates the utilization of weaker PARP inhibitors with additional therapeutic properties. Nicotinamide (vitamin B3) is a weak PARP inhibitor, antioxidant, and calcium modulator and can improve energy status and inhibit cell death in ischemic tissues. We report the dose-dependent effects of nicotinamide in an established model of early DPN. Control and streptozotocin-diabetic rats were treated with 200 to 400 mg/kg/day nicotinamide (i.p.) for 2 weeks after 2 weeks of untreated diabetes. Sciatic endoneurial nutritive blood flow was measured by microelectrode polarography and hydrogen clearance, and sciatic motor and hind-limb digital sensory nerve conduction velocities and thermal and mechanical algesia were measured by standard electrophysiological and behavioral tests. Malondialdehyde plus 4-hydroxyalkenal concentration in the sciatic nerve and amino acid-(4)-hydroxynonenal adduct and poly(ADP-ribosyl)ated protein expression in human Schwann cells were assessed by a colorimetric method with N-methyl-2-phenyl indole and Western blot analysis, respectively. Nicotinamide corrected increased sciatic nerve lipid peroxidation in concert with nerve perfusion deficits and dose-dependently attenuated nerve conduction slowing, as well as mechanical and thermal hyperalgesia. Nicotinamide (25 mM) prevented high (30 mM) glucose-induced overexpression of amino acid-(4)-hydroxynonenal adducts and poly(ADP-ribosyl)ated proteins in human Schwann cells. In conclusion, nicotinamide deserves consideration as an attractive, nontoxic therapy for the treatment of DPN.

Taurine reverses neurological and neurovascular deficits in Zucker diabetic fatty rats

Increased oxidative stress is implicated in the pathogenesis of diabetic peripheral neuropathy (DPN). However, the efficacy of antioxidant therapy on DPN complicating type 2 diabetes remains unexplored. We therefore determined the ability of the antioxidant taurine to reverse deficits of hind limb sciatic motor and digital sensory nerve conduction velocity (NCV), nerve blood flow (NBF), and sensory thresholds in hyperglycemic Zucker diabetic fatty (ZDF) rats. Experimental groups comprised lean nondiabetic (ND), ND treated with taurine (ND + T), untreated ZDF diabetic (D), and D rats treated with taurine (D + T). Compared to ND rats, 23%, 15% and 56% deficits of motor NCV, sensory NCV and NBF, respectively as well as thermal and mechanical hyperalgesia were reversed by taurine. An 84% deficit of dorsal root ganglion neuron calcitonin gene-related peptide in D rats was prevented by taurine. In summary, the antioxidant taurine reverses neurological and neurovascular deficits in experimental type 2 diabetes.

The detection of circulating breast cancer cells in blood

At present, sampling of the lymph nodes or bone marrow for the detection of regions of metastatic disease in patients with breast cancer can only be undertaken at the time of initial diagnosis and surgery. However, the sampling of these tissues and the methods used are inaccurate, time consuming, and cannot be used for easy routine screening to determine disease recurrence and response to treatment. Because of the problems encountered with current methods and tissues sampled at the time of breast cancer diagnosis, this review discusses the urgent requirement for and potential development of a quick, simple, and accurate diagnostic test utilising the haematogenous system, a source of circulating tumour cells in patients with breast cancer, and highly sensitive molecular biological techniques, such as reverse transcription polymerase chain reaction. In addition, this review also highlights potential problems that may be encountered and should be avoided when devising such a test.

Inhalation toxicity of Cyclosarin (GF) vapor in rats as a function of exposure concentration and duration: potency comparison to sarin (GB)

The inhalation toxicity of cyclohexyl methylphosphonofluoridate (GF) was examined in male and female Sprague-Dawley rats exposed by whole body in a dynamic 750-L chamber. The objectives of this study were to (1) generate GF vapor in a dynamic inhalation chamber system, starting in the lethal to near-lethal concentration range, (2) examine dose-response effects of inhaled GF vapor and analyze the relationship between concentration (C) and exposure duration (T) in determining probability of lethality, and (3) establish a lethal potency ratio between GF and the more volatile agent Sarin (GB). Using a syringe pump, GF vapor concentrations were generated for exposure times of 10, 60, and 240 min. Dose-response curves with associated slopes were determined for each exposure duration by the Bliss probit method. GF vapor exposures were associated with sublethal clinical signs such as tremors, convulsions, salivation, and miosis. Concentration-exposure time values for lethality in 50% of the exposed population (LCT(50)) were calculated for 24-h and 14-day postexposure periods for 10-, 60-, and 240-min exposures. In general, LCT(50) values were lower in female rats than males and increased with exposure duration; that is, CT was not constant over time. The GF LCT(50) values for female rats were 253 mg min/m(3) at 10 min, 334 mg min/m(3) at 60 min, and 533 mg min/m(3) at 240 min, while the values for males were 371, 396, and 585 mg min/m(3), respectively. The GB LCT(50) values for female rats were 235 mg min/m(3) at 10 min, 355 mg min/m(3) at 60 min, and 840 mg min/m(3) at 240 min, while the values for males were 316, 433, and 1296 mg min/m(3), respectively. At longer exposure durations, the LCT(50) for GF was less than that found for GB but at shorter exposure durations, the LCT(50) for GF was more than that found for GB. Empirical models, consisting of the toxic load model plus higher order terms, were developed and successfully fit to the data.

Clinical pathology accreditation: standards for the medical laboratory

This article describes a new set of revised standards for the medical laboratory, which have been produced by Clinical Pathology Accreditation (UK) Ltd (CPA). The original standards have been in use since 1992 and it was recognised that extensive revision was required. A standards revision group was established by CPA and this group used several international standards as source references, so that the resulting new standards are compatible with the most recent international reference sources. The aim is to make the assessment of medical laboratories as objective as possible in the future. CPA plans to introduce these standards in the UK in 2003 following extensive consultation with professional bodies, piloting in selected laboratories, and training of assessors.

Interaction of exposure concentration and duration in determining acute toxic effects of sarin vapor in rats

Sarin (GB) vapor exposure is associated with both systemic and local toxic effects occurring primarily via the inhalation and ocular routes. The objective of these studies was to develop models for predicting dose-response effects of GB vapor concentrations as a function of exposure duration. Thus, the probability of GB vapor-induced lethality was estimated in rats exposed to various combinations of exposure concentration and duration. Groups of male and female Sprague-Dawley rats were exposed to one of a series of GB vapor concentrations for a single duration (5-360 min) in a whole-body dynamic chamber. The onset of clinical signs and changes in blood cholinesterase activity were measured with each exposure. Separate effective concentrations for lethality in 50% of the exposed population (LC50) and corresponding dose-response slopes were determined for each exposure duration by the Bliss probit method. Contrary to that predicted by Haber's rule, the interaction of LC50 x time (LCT50) values increased with exposure duration (i.e., the CT for 50% lethality in the exposed population and corresponding dose-response slope was not constant over time). A plot of log (LCT50) versus log (exposure time) showed significant curvature. Predictive models derived from multifactor probit analysis of results describing the relationship between exposure conditions and probability of lethality in the rat are discussed. Overall, female rats were more sensitive to GB vapor toxicity than male rats over the range of exposure concentration and duration studied. Miosis was the initial clinical sign noted after the start of GB vapor exposure. Although blood cholinesterase activity was significantly inhibited by GB vapor exposure, poor correlation between cholinesterase inhibition and exposure conditions or cholinesterase inhibition and severity of clinical signs was noted.

Looking over the horizon: an Internet-based international course in healthcare management

The International Course in Healthcare Management is predicated on the belief that comparative benefits can most effectively be 'taught' by enabling students to work directly with colleagues in other countries, sharing views, discussing differences, and checking understandings on how healthcare is structured and managed in different countries. The course focuses on four countries--Canada, Germany, Finland and Ireland--which offer an interesting range and mix of approaches to healthcare, and yet are sufficiently similar to ensure relative ease of understanding. The course, which is delivered and taught jointly by faculty from five participating institutions in the four countries using the Internet as the distance delivery medium, is an integral component of each institution's participating department's graduate program. The aims of the course are: to enable the participants to develop an in-depth understanding of the healthcare systems of each country; to foster a deeper understanding, through comparative analysis, of each participant's own healthcare system; and to facilitate the development of new insights into ways of addressing common concerns in healthcare management. The course is structured around a series of case studies organized under four main themes: financing and funding; delivery issues; impact of health service reforms; and evidence-based management.

Standards for the medical laboratory--harmonization and subsidiarity

An International Standard, ISO 15189, specifically for 'Quality management in the medical laboratory' for use by accrediting 'bodies that recognize the competence of medical laboratories,' is expected to be published shortly. The origins, content and limitations of the new standard are discussed and the diversity of current arrangements for accreditation is reviewed. A new International Standard is an important step towards harmonization of laboratory practice but an accreditation system is more than its standards and a harmonized approach to the treatment of noncompliances found at inspection is important. Experience gained in writing national standards can improve the approach to the drafting and improvement of International Standards. Recognition of the principle of subsidiarity aids rather than hinders progress to harmonization and empowers the 'fourth element' (the laboratories to be accredited) to be a part of the accreditation process.

Expression and activity of ADAMTS-5 in synovium

ADAMTS proteinases, belonging to the adamalysin subfamily of metalloproteinases, have been implicated in a variety of cellular events such as morphogenesis, cell migration, angiogenesis, ovulation and extracellular matrix breakdown. Aggrecanase-1 (ADAMTS-4) and aggrecanase-2 (ADAMTS-5) have been identified in cartilage and are largely responsible for cartilage aggrecan breakdown. We have shown previously that synovium, the membrane lining diarthrodial joints, generates soluble aggrecanase activity. We report here the expression, localization and activity of ADAMTS-5 from human arthritic and bovine synovium. ADAMTS-5 was expressed constitutively in synovium with little or no transcriptional regulation by recombinant human interleukin-1 alpha or all-trans-retinoate, factors previously shown to upregulate aggrecanase activity in cartilage. Aggrecanase activity generated by synovium in vitro and recombinant ADAMTS-5 cleaved aggrecan extensively, resulting in aggrecan fragments similar to those generated by chondrocyte-derived aggrecanases, and the activity was inhibited by heparin. ADAMTS-5 was immunolocalized in human arthritic synovium, where staining was mostly pericellular, particularly in the synovial lining and around blood vessels; some matrix staining was also seen. The possibility that synovium-derived ADAMTS-5 may play a role in cartilage aggrecan breakdown is discussed.

Usefulness of EC4 essential criteria for quality systems of medical laboratories as guideline to the ISO 15189 and ISO 17025 documents. European Community Confederation of Clinical Chemistry (EC4) Working Group on Harmonisation of Quality Systems and Accreditation

Many medical laboratories have made a start with the introduction of quality management systems. However, it is still not clear against which standards such systems should be measured. The existing ISO and CEN standards do not cover essential aspects of medical laboratories. The publication of the EC4 Essential Criteria has stimulated the development of the ISO/Draft International Standard 15189. This standard seems adequate for our type of laboratories. However, it is not easy to read. The EC4 Essential Criteria could well serve as a guide, covering additional aspects, e.g. on total quality management and budget management as required in the EFQM model, that are not (yet) included in the ISO standard. In the present article the EC4 Essential Criteria are cross-referenced with two new international ISO standards, ISO/FDIS 15189 and ISO/FDIS 17025, the latter being the successor of ISO guide 25 and EN 45000. Both new ISO documents are in compliance with the new ISO 9000:2000 standard.

Toxicity evaluation of petroleum blending streams: inhalation subchronic toxicity/neurotoxicity study of a light catalytic reformed naphtha distillate in rats

A 13-wk whole-body inhalation study was conducted with Sprague-Dawley CD rats (16/sex/group) exposed to a light catalytic reformed naphtha distillate (LCRN-D, CAS number 64741-63-5) at target concentrations of 0, 750, 2500, and 7500 ppm for 6 h/d, 5 d/wk. Sixteen rats per sex in the control and high-dose groups were maintained after final exposure for a 4-wk recovery period. The highest exposure concentration was 75% of the lower explosive limit. Standard parameters of subchronic toxicity were measured throughout the study; at necropsy, organs were weighed and tissues processed for microscopic evaluation. Neurotoxicity evaluations consisted of motor activity (MA) and a functional operational battery (FOB) measured pretest, throughout exposure and after the recovery period. Neuropathology was evaluated at termination. No test-related mortality or effects on physical signs, body weight, food consumption, or clinical chemistry were observed. In males exposed to 7500-ppm LCRN-D, a statistically significant decrease in white blood cell counts and lymphocyte counts was observed at the termination of exposure that was not present in animals after the 4-wk recovery period. However, mean corpuscular volume was slightly decreased in high-dose males after the recovery period. Statistically significant increases in kidney weights relative to body weights in 7500-ppm male rats correlated with microscopically observed hyaline droplet formation and renal tubule dilation, indicative of light hydrocarbon nephropathy, a condition in male rats that is not toxicologically significant for humans. Statistically significant decrease in absolute and relative spleen weights in 7500-ppm male rats correlated with decreases in hematologic parameters but had no microscopic correlate and was not observed in animals after 4 wk of recovery. This mild, reversible effect in white blood cell populations may relate to the presence of aromatics in the distillate. The only effect of LCRN-D on neurobehavioral parameters was significantly higher motor activity counts among high-dose (7500 ppm) males after the 4-wk recovery period, suggesting a possible delayed effect of LCRN-D. However, there was no evidence of hyperactivity or abnormal behavior from the functional observational battery evaluations, and there were no microscopic changes in neural tissue to support this observation. The no-observed-adverse-effects level (NOAEL) for LCRN-D was 2500 ppm for both subchronic toxicity and neurotoxicity. The no-observed-effects level (NOEL) was 750 ppm.

Toxicity evaluation of petroleum blending streams: reproductive and developmental effects of light catalytic reformed naphtha distillate in rats

A distillate of light catalytic reformed naphtha (CAS number 64741-63-5, LCRN-D) administered by inhalation was tested for reproductive and developmental toxicity in Sprague-Dawley rats, following a modified OECD Guideline 421, Reproductive/Developmental Toxicity Screening protocol. LCRN-D was administered as a vapor, 6 h/d, 7 d/wk at target concentrations of 0, 750, 2500 or 7500 ppm to female rats for approximately 6 wk from 2 wk prior to mating, during mating through gestational d 19, and to males beginning 2 wk prior to mating for approximately 7 consecutive weeks. Dams and litters were sacrificed on postnatal d 4 and males were sacrificed within the week after the last litter was necropsied. Parental systemic effects observed at the 7500 ppm exposure level included slightly lower body weights for males throughout the study. Increased kidney to body weight and increased liver to body weight ratio in male rats exposed to 7500 ppm LCRN-D may be related to slightly lower final mean body weights. Body and organ weight data for female rats in all exposure groups were comparable to controls. No test-material-related microscopic changes were observed in the reproductive organs or nasal turbinate tissue of either sex. Reproductive performance was unaffected by exposure to LCRN-D. The mating and fertility indices were 100% in all groups. There were no significant exposure-related differences in implantation sites or live pups per litter, and no gross abnormalities were observed in pups from treated dams. Pups born from LCRN-D-exposed dams showed comparable body weights and weight gain to control pups. The viability index on postpartum d 4 was > or =97%. Under conditions of this study, the no-observed-adverse-effect level (NOAEL) for exposure to light catalytic reformed naphtha distillate for parental effects was 2500 ppm and the NOAEL for reproductive and developmental toxicity was 7500 ppm.

Female gender associates with increased duration of intubation and length of stay after coronary artery surgery. CABG Clinical Benchmarking Database Participants

BACKGROUND

Females have worse outcome than do males after coronary artery bypass grafting; however, gender effects on length of stay (LOS) outcomes, such as duration of intubation or intensive care unit (ICU) LOS, have not been evaluated previously. The authors hypothesized that adjustment for pertinent preoperative covariates would eliminate any significant effect of gender on duration of intubation, LOS in the ICU after extubation, total ICU LOS, postoperative (exclusive of ICU) LOS, or total postoperative LOS.

METHODS

Patients undergoing elective or urgent primary coronary artery bypass grafting surgery at 51 academic health centers in 1995 and 1997 were studied. Unique multivariable statistical models were developed for duration of intubation, ICU LOS after extubation, total ICU LOS, and postoperative (exclusive of ICU and total) LOS to test for independent associations with gender. Preoperative but not intraoperative or postoperative variables were included in the model. P> or =0.01 was considered significant.

RESULTS

All LOSs were of significantly longer duration in females than in males in both the 1995 (n = 1,064) and 1997 (n = 910) data collections. After covariate adjustment, female sex remained associated with significantly longer duration ICU LOS and total postoperative LOS in both the 1995 (female:male ratios 1.30:1 and 1.13:1, respectively) and the 1997 (female:male ratios 1.19:1 and 1.12:1, respectively) data sets. After covariate adjustment, duration of intubation and ICU LOS after extubation were of significantly longer duration in women than men in 1995 (female:male ratios 1.22:1 and 1.39:1, respectively), but the differences were not significant in 1997.

CONCLUSIONS

Even in the context of accelerated recovery programs, these analyses show that female sex has powerful associations with increased LOS intervals for coronary artery bypass grafting surgery, even after adjustment for preoperative covariates. These effects could result from differences in the ways in which men and women respond to coronary artery disease, anesthesia, and coronary artery bypass grafting surgery, or to bias on the part of healthcare workers.

Toxicity evaluation of petroleum blending streams: reproductive and developmental effects of light catalytic cracked naphtha distillate in rats

A distillate of light catalytic cracked naphtha (CAS number 64741-55-5, LCCN-D), administered by inhalation, was tested for reproductive and developmental toxicity in Sprague-Dawley rats, following a modified OECD Guideline 421, Reproductive/Developmental Toxicity Screening Protocol. LCCN-D was administered as a vapor, 6 h/d, 7 d/wk at target concentrations of 0, 750, 2500 or 7500 ppm to female rats for approximately 7 wk from 2 wk prior to mating, during mating through gestational d 19, and to males beginning 2 wk prior to mating for 8 consecutive weeks. Dams and litters were sacrificed on postnatal d 4, and males were sacrificed within the following week. Parental systemic effects observed at the 7500 ppm exposure level were increased kidney weights and relative liver weights in males and increased spleen weights in high-dose females. Livers and spleens from rats in the high-dose group were normal in appearance at necropsy. IncreaSed kidney weights in high-dose males were indicative of male-rat-specific light hydrocarbon nephropathy. No test-related microscopic changes were observed in the reproductive organs or nasal turbinate tissues of either sex. Reproductive performance was unaffected by treatment with LCCN-D. Fertility index was > or =90% in all dose groups. There were no exposure-related differences in implantation sites and live pups per litter, and no gross abnormalities were observed. Pups born from treated dams showed comparable body weights and weight gains to controls. The viability index on postpartum d 4 was > or =97%; the high-dose group had more male than female pups at birth and at d 4 postpartum. Under the conditions of this study, the no-observable-adverse-effect level (NOAEL) for exposure to light catalytic cracked naphtha distillate for parental toxicity was 2500 ppm and the NOAEL for reproductive performance and developmental toxicity was 7500 ppm.

Use of intravenous adenosine as a noninvasive diagnostic test for sick sinus syndrome

BACKGROUND

Testing for sick sinus syndrome (SSS) requires invasive stimulation protocols for sinus node recovery time (SNRT) and corrected sinus node recovery time (CSNRT).

METHODS AND RESULTS

We compared the CSNRT with the lengthening of the sinus cycle length (ADO:SCL) corrected to the basic cycle length (ADO:CSNRT) after administration of an intravenous bolus of adenosine (0.15 mg/kg) in 10 patients with clinical SSS (group 1) and 67 control patients (group 2). With 550 ms as an abnormal result for the ADO:CSNRT (and for the CSNRT) as an indicator of sinus node dysfunction, the ADO:CSNRT had a sensitivity of 80% and specificity of 97% for detection of SSS compared with sensitivity and specificity of 70% and 95% for invasive CSNRT. When combined, the 2 tests had a sensitivity of 100%. There was significant difference in the CSNRT between group 1 (1848 +/- 1825 ms) and group 2 (355 +/- 169 ms, P <. 0001) and a significant difference in ADO:CSNRT between group 1 (1168 +/- 1002 ms) and group 2 (272 +/- 592 ms, P <.0001).

CONCLUSIONS

We conclude that the ADO:CSNRT is a sensitive and specific test for SSS that equals invasive testing and should be considered as an alternative to invasive testing in patients with suspected SSS.

A direct correlation between nicotinamide N-methyltransferase activity and protein levels in human liver cytosol

Phenotypic differences in nicotinamide N-methyltransferase (NNMT, E. C. 2.1.1.1) activity may be due to a genetic polymorphism. We report the characterisation of the hepatic NNMT activity in cytosol from normal human livers, enzyme protein levels determined by Western blotting and ELISA and mRNA levels determined by SDS-PAGE/Northern blotting. Subjects with high NNMT activity had high levels of NNMT protein and NNMT mRNA levels in hepatic cytosol and the converse was true for individuals with low NNMT activity. No differences in sequences were seen when cDNAs of individuals with high and low NNMT activity were compared. Thus phenotypic differences in the general population are due to differences in steady-state mRNA levels and not because of a polymorphism in the coding region of the NNMT gene.