Impact of external quality assessment on antinuclear antibody detection performance.

Our objective was to evaluate performance of the clinical laboratories for the detection of antinuclear antibodies (ANA) by using indirect immunofluorescence method (IIF), in France. A national external quality assessment (EQA) on ANA detection was organized by the French health products safety agency once a year since 1998. Between 606 to 687 laboratories together with six university reference laboratories experienced in performing tests in autoimmunity participated in the six-year consecutive survey.

[Monoclonal immunoglobulin: national external quality assessment and diagnostic reasoning].

In 2003, for the scheme of the French national external quality assessment, Afssaps sent to medical laboratories a sample for which two analyses could be carried out: the electrophoresis of proteins and the characterization for monoclonal immunoglobulin. The purpose of this new approach was to make it possible to the laboratories to transpose their usual diagnostic reasoning. This survey recalled to the biologists that it is necessary to check the sensitivity of the test of electrophoresis of proteins used in first intention and to use advisedly the anti-serums anti-free chains.

Perceptual learning through optimization of attentional weighting: human versus optimal Bayesian learner.

Human performance in visual detection, discrimination, identification, and search tasks typically improves with practice. Psychophysical studies suggest that perceptual learning is mediated by an enhancement in the coding of the signal, and physiological studies suggest that it might be related to the plasticity in the weighting or selection of sensory units coding task relevant information (learning through attention optimization). We propose an experimental paradigm (optimal perceptual learning paradigm) to systematically study the dynamics of perceptual learning in humans by allowing comparisons to that of an optimal Bayesian algorithm and a number of suboptimal learning models.

Evidence for a role of the parafascicular nucleus of the thalamus in the control of epileptic seizures by the superior colliculus.

Purpose: The aim of this study was to investigate whether the nucleus parafascicularis (Pf) of the thalamus could be a relay of the control of epileptic seizures by the superior colliculus (SC). The Pf is one of the main ascending projections of the SC, the disinhibition of which has been shown to suppress seizures in different animal models and has been proposed as the main relay of the nigral control of epilepsy.

Methods: Rats with genetic absence seizures (generalized absence epilepsy rat from Strasbourg or GAERS) were used in this study.

Prevalence and diagnosis of migraine in patients consulting their physician with a complaint of headache: data from the Landmark Study.

Context: Headache experts have suggested that to improve the recognition of migraine, patients with a stable pattern of episodic, disabling headache and a normal physical exam should be considered to have migraine in the absence of contradictory evidence. The premise upon which this approach is based-that is, that episodic, recurrent primary headache in the clinic is usually migraine-has not been evaluated in prospective clinical studies.

Objectives: To (1) evaluate the diagnoses of patients consulting their physician with primary episodic headache and (2) compare clinic diagnoses and patient self-diagnoses with International Headache Society (IHS) headache diagnoses assigned on the basis of longitudinal data from patient diaries.

Association of idiopathic hepatic sinusoidal dilatation with the immunological features of the antiphospholipid syndrome.

Background: Isolated sinusoidal dilatation is an uncommon hepatic lesion and the cause is largely unknown.

Objective: To investigate whether prothrombotic disorders or perisinusoidal cell changes could be involved in pure idiopathic hepatic sinusoidal dilatation (HSD).

Methods: Evaluation for associated conditions, prothrombotic disorders, and studies of hepatic perisinusoidal cell activation in consecutive patients, seen between 1993 and 2002, with isolated sinusoidal dilatation unrelated to outflow block, sinusoidal infiltration, or hepatic granulomas.

Anatomic M-mode, a pertinent tool for the daily practice of transthoracic echocardiography.

Objectives: We sought to compare anatomic M-mode (AMM), a new echocardiographic postprocessing option, and conventional M-mode (CMM) using fundamental imaging and tissue harmonic imaging.

Methods: Transthoracic echocardiography was performed in 15 selected patients to analyze the reproducibility of AMM and in 47 patients to assess its clinical value versus CMM. Acquisitions were performed successively: CMM fundamental imaging; CMM tissue harmonic imaging; tissue harmonic imaging cineloops for AMM; and fundamental imaging cineloops for AMM.

An antineutrophil cytoplasmic autoantibody associated with a propylthiouracil-induced adult respiratory distress-like syndrome: report of a case and review of the literature.

Objective: To report the first case of propylthiouracil-induced adult respiratory distress-like syndrome associated with the presence of an antineutrophil cytoplasmic autoantibody.

Methods: We describe the initial manifestations, laboratory findings, and clinical course in a patient and discuss underlying factors potentially contributing to her condition.

Results: A 57-year-old woman with hyperthyroidism had an influenza-like illness and vasculitis during propylthiouracil therapy.

Evaluation of JPEG 2000 encoder options: human and model observer detection of variable signals in X-ray coronary angiograms.

Previous studies have evaluated the effect of the new still image compression standard JPEG 2000 using nontask based image quality metrics, i.e., peak-signal-to-noise-ratio (PSNR) for nonmedical images.

Automated optimization of JPEG 2000 encoder options based on model observer performance for detecting variable signals in X-ray coronary angiograms.

Image compression is indispensable in medical applications where inherently large volumes of digitized images are presented. JPEG 2000 has recently been proposed as a new image compression standard. The present recommendations on the choice of JPEG 2000 encoder options were based on nontask-based metrics of image quality applied to nonmedical images.

The footprints of visual attention during search with 100% valid and 100% invalid cues.

Human performance during visual search typically improves when spatial cues indicate the possible target locations. In many instances, the performance improvement is quantitatively predicted by a Bayesian or quasi-Bayesian observer in which visual attention simply selects the information at the cued locations without changing the quality of processing or sensitivity and ignores the information at the uncued locations. Aside from the general good agreement between the effect of the cue on model and human performance, there has been little independent confirmation that humans are effectively selecting the relevant information.

The inclusion of reports of randomised trials published in languages other than English in systematic reviews.

Objective: To assemble a large dataset of language restricted and language inclusive systematic reviews, including both conventional medicinal (CM) and complementary and alternative medicine (CAM) interventions. To then assess the quality of these reports by considering and comparing different types of systematic reviews and their associated RCTs; CM and CAM interventions; the effect of language restrictions compared with language inclusions, and whether these results are influenced by other issues, including statistical heterogeneity and publication bias, in the systematic review process.

Data Sources: MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and the Centralised Information Service for Complementary Medicine.

Should meta-analysts search Embase in addition to Medline?

It is widely accepted that meta-analysts should search multiple databases. The selection of databases is ideally based on the potential contribution of each database to the project or on the potential for bias if a database is excluded, as supported by research evidence. We explore whether searching Embase yields additional trials that influence a meta-analysis.

Differential expression of perforin and granzyme B in the liver of patients with chronic hepatitis C.

T lymphocytes have been reported to be the predominant inflammatory cells in the liver of patients with chronic hepatitis C. On activation, CD8+ T lymphocytes can exert their cytolytic activity by releasing their granule components, notably perforin and granzyme B. The aim of the present study was to assess whether the granule cytolytic pathway was used by liver-infiltrating CD8+ T lymphocytes.

Five-year survival predictive factors in patients with excessive alcohol intake and cirrhosis. Effect of alcoholic hepatitis, smoking and abstinence.

Aim: To evaluate 5-year survival predictive factors in hospitalised patients with excessive alcohol intake and cirrhosis, including in a multivariate analysis the severity of the liver disease, gastrointestinal bleeding, concomitant viral B or C infection, smoking status, presence of alcoholic hepatitis at inclusion and abstinence from alcohol during follow-up.

Methods: In a non-concurrent cohort study, 122 patients with excessive alcohol intake and cirrhosis were followed up at least five years or till death. Two patients were lost to follow-up.

Suppression of absence seizures by electrical and pharmacological activation of the caudal superior colliculus in a genetic model of absence epilepsy in the rat.

Activation of the superior colliculus has been shown to reproduce the antiepileptic effect of the inhibition of the substantia nigra reticulata. A circuit involving neurons of the caudal deep layers of the superior colliculus has been suggested to control brain stem convulsive seizures. The present study was designed to examine whether a similar circuit is also involved in the control of absence seizures.

Early detection of cysteine rich protein 61 (CYR61, CCN1) in urine following renal ischemic reperfusion injury.

Background: Acute renal failure (ARF) has a high morbidity and mortality. Many therapies have worked in animals but were unsuccessful in clinical trials. The inability to diagnose ARF early may have impaired the success of these trials.

Acyl dipeptides as reversible caspase inhibitors. Part 2: further optimization.

A new structural class of broad spectrum caspase inhibitors was optimized for its activity against caspases 1, 3, 6, 7, and 8. The most potent compound had low nanomolar broad spectrum activity, in particular, single digit nanomolar inhibitory activity against caspase 8.

Acyl dipeptides as reversible caspase inhibitors. Part 1: initial lead optimization.

Parallel synthesis was used to explore the SAR of a peptidomimetic caspase inhibitor. The most potent compound had nanomolar activity against caspases 1, 3, 6, 7, and 8.

Meta-analysis of randomised controlled trials of the effectiveness of antiarrhythmic agents at promoting sinus rhythm in patients with atrial fibrillation.

Objective: To conduct a meta-analysis of randomised controlled trials to estimate the effectiveness of antiarrhythmic drugs at promoting sinus rhythm in patients with atrial fibrillation.

Design: Articles were identified by using a comprehensive search of English language papers indexed in Medline from 1966 to August 2001. For the outcomes of sinus rhythm and death, a random effects model was used to model repeated assessments within a study at different time points.

Serum hepatitis B virus DNA levels and liver histology in inactive HBsAg carriers.

Background/aims: A recent NIH research workshop on hepatitis B virus (HBV) revisited the definition of healthy HBsAg carriers. The new definition inactive surface antigen (HBsAg) carriers includes an estimated serum HBV DNA level below 105 copies/ml. However, this cut-off value needs to be confirmed.

A comparison of the quality of Cochrane reviews and systematic reviews published in paper-based journals.

This study set out to compare Cochrane reviews and reviews published in paper-based journals. Two assessment tools were used to collect the data, a 23-item checklist developed by Sacks and a nine-item scale developed by Oxman. Cochrane reviews were found to be better at reporting some items and paper-based review at reporting others.

How efficacious and safe is short-acting methylphenidate for the treatment of attention-deficit disorder in children and adolescents? A meta-analysis.

Background: Numerous small clinical trials have been carried out to study the behaviourally defined efficacy and safety of short-acting methylphenidate compared with placebo for attention-deficit disorder (ADD) in individuals aged 18 years and less. However, no meta-analyses that carefully examined these questions have been done. We reviewed the behavioural evidence from all the randomized controlled trials that compared methylphenidate and placebo, and completed a meta-analysis.

Prospective study on anti-hepatitis C virus-positive patients with persistently normal serum alanine transaminase with or without detectable serum hepatitis C virus RNA.

A significant proportion of patients with detectable antibodies to hepatitis C virus have normal serum alanine transaminase levels. Our aim was to study the outcome of this group. Between 1992 and 1999, 135 consecutive anti-HCV-positive patients with persistently normal ALT were followed for 3.