Molecular and immunological characterization of wheat Serpin (Tri a 33)

SCOPE

Several wheat proteins are responsible for food and respiratory allergies. Due to their large polymorphism, the allergenic potential of a number of them has not yet been precisely established. The aim of this work was to perform a thorough assessment of serpin (Tri a 33) allergenicity.

METHODS AND RESULTS

Recombinant wheat Serpin-Z2B isoform (rSerpin-Z2B) was expressed in Escherichia coli. Synchrotron radiation circular dichroism data indicated that the recombinant serpin contains slightly more β-strands than α-helix structures. IgE reactivity of sera from 103 patients with food allergy and 29 patients with Baker's asthma was evaluated using ELISA, a model of basophil activation and linear epitope mapping (Pepscan). Twenty percent of patients with food allergy to wheat and 31% of those with Baker's asthma displayed rSerpin-Z2B-specific IgE in ELISA. The protein was able to induce IgE-dependent basophil degranulation. The Pepscan experiment identified four regions involved in IgE binding to serpin. Heating the protein induced its irreversible denaturation and impaired IgE binding, revealing the predominance of conformational epitopes.

CONCLUSION

This study confirms wheat serpin allergenicity and shows that recombinant serpin may be a marker of a broad spectrum of sensitization to wheat proteins.

Testing independence between two sequential gap times in the presence of covariates

In the risk analysis of sequential events, the successive gap times are often correlated, e.g. as a result of an individual heterogeneity. Correlation is usually accounted for by using a shared gamma-frailty model, where the variance φ of the random individual effect quantifies the correlation between gap times. This method is known to yield satisfactory estimates of covariate effects, but underestimates φ, which could result in a lack of power of the test of independence. We propose a new test of independence between two sequential gap times where the first is the time elapsed from the origin. The test is based on an approximation of the hazard of the second event given the first gap time in a frailty model, with a frailty distribution belonging to the power variance function family. Simulation results show an increased power of the new test compared with the test derived from the gamma-frailty model. In the realistic case where hazards are event specific, and using event-specific approaches, the proposed estimation of the variance of the frailty is less biased than the gamma-frailty based estimation for a wide range of values (φ < 2.5 with the set of parameters considered), and similar for higher values. As an illustration, the methods are applied to a previously analysed asthma prevention trial with results showing a significant positive association between the successive times to asthmatic events. We also analyse data from a cohort of HIV-seropositive patients in order to assess the effect of risk factors on the occurrence of two successive markers of progression of the HIV disease. The results demonstrate the ability of the proposed model to account for negative correlations between gap times.

A model-based statistic for detecting molecular markers associated with complex survival patterns in early-stage cancer

BACKGROUND

In early-stage of cancer, primary treatment can be considered as effective at eliminating the tumor for a non-negligible proportion of patients whereas for the others it leads to a lower tumor burden and thereby potentially prolonged survival. In this mixed population of patients, it is of great interest to detect complex differences in survival distributions associated with molecular markers that potentially activate latent downstream pathways implicated in tumor progression.

METHOD

We propose a novel model-based score test designed for identifying molecular markers with complex effects on survival in early-stage cancer. From a biological point of view, the proposed score test allows to detect complex changes in the survival distributions linked to either the tumor burden or its dynamic growth.

RESULTS

Simulation results show that the proposed statistic is powerful at identifying departure from the null hypothesis of no survival difference. The practical use of the proposed statistic is exemplified by analyzing the prognostic impact of Kras mutation in early-stage of lung adenocarcinomas. This analysis leads to the conclusion that Kras mutation has a significant negative prognostic impact on survival. Moreover, it emphasizes that the complex role of Kras mutation on survival would have been overlooked by considering results from the classical logrank test.

CONCLUSION

With the growing number of biological markers to be tested in early-stage cancer, the proposed score test statistic is a powerful tool for detecting molecular markers associated with complex survival patterns.

Circadian rest-activity rhythm as a predictor of survival in metastatic colorectal cancer

e14006

Background: Experimental disruption of the Circadian Timing System (CTS) accelerates cancer progression. The relative amount of activity in-bed versus out-of-bed (I<O) was identified as a quantitative CTS estimate that predicted survival in two cohorts of patients with metastatic colorectal cancer (CI, CII). Methods: The independent prognostic value of I<O was investigated for Overall Survival (OS) and Progression-Free Survival (PFS) 1) in a new cohort of 142 patients (CIII) receiving circadian-based salvage treatment for metastatic colorectal cancer, and 2) in a pooled population of 436 patients from cohorts I-III. All patients had two-day rest-activity rhythm monitoring and then received a new treatment. Cohort-adjusted data were analyzed with log rank and multivariate Cox analyses. Results: Patients in CIII had poor prognosis disease compared to CI and CII, as assessed by prior chemotherapy (CIII, 69%; CI, 59.5%; CII, none), prior oxaliplatin (CIII, 55%; CII, none; CI, 2%) and/or irinotecan (CIII, 39.4%; CII, none; CI, 7%). The 273 male and 163 female patients in the pooled population had generally good performance status 0 (60.7%) or 1 (33.1%) and 51% had two or more metastatic sites. Following rest-activity rhythm determination, patients received a median of 8 chemotherapy courses. Median OS was 21.6 months [95% Confidence Limits, 17.8 to 25.5] in the patients with I<O above the cutoff median value of 97.5% as compared to 11.9 months [10.4 to 13.3] in those with a lower I<O (p from Log rank < 0.001). The adjusted relative risk related to I<O above cutoff was 0.587 [0.477 to 0.722] for earlier death (p<0.001) and 0.661 [0.542 to 0.807] for earlier progression (p <0.001). Conclusions: The circadian biomarker indicator I<O is a robust and independent quantitative long-term predictor of both OS and PFS in patients with metastatic colorectal cancer. Cancer patients with low I<O could potentially benefit from specific treatments for circadian disruption in order to enhance survival.

Naturally occurring substitutions of conserved residues in human immunodeficiency virus type 1 variants of different clades are involved in PG9 and PG16 resistance to neutralization

The recently described anti-human immunodeficiency virus type 1 (HIV-1) human mAb PG9 and PG16 are cross-clade broadly neutralizing. Therefore, it can be postulated that the targeted epitope(s) are highly conserved among variants of the entire group M. We analysed the sensitivity to PG9 and PG16 of pseudotyped viruses carrying envelope glycoproteins from the viral quasispecies of three HIV-1 clade CRF01_AE-infected patients. The broad heterogeneity in sensitivity to PG9 and PG16, despite closely genetically related envelope glycoproteins issued from single individuals, allowed us to identify two gp120 cross-clade conserved residues, a lysine at position 168 in the V2 loop and an isoleucine at position 215 in the C2 region, whose substitutions were associated with resistance to PG9 and PG16. By site-directed mutagenesis, we confirmed both in clades B and CRF01_AE that the substitutions K168E and I215M have a major impact on PG9 and PG16 neutralization sensitivity of pseudotyped viruses.

Circadian robustness as an independent predictor of prolonged progression-free survival (PFS) and overall survival (OS) in 436 patients with metastatic colorectal cancer (mCRC)

464

Background: The rest-activity rhythm is a biomarker of the circadian timing system (CTS), whose disruption accelerates cancer progression in experimental models. Prior studies in cancer pts identified a reliable measure of CTS function in cancer pts based on non invasive wrist actigraphy monitoring.

Methods: The prognostic value of I<O, the ratio between activity counts in-bed vs out-of-bed, was explored for PFS and OS in mCRC. The rest-activity rhythm was recorded for >48 h in 436 mCRC pts from 3 international cohorts. Data were stratified per cohort, and analyzed with Kruskall-Wallis ANOVA, log rank tests, and multivariate Cox analyses.

Results: Median age was 59.2 y. Pts were mainly men (62.6%); had good performance status (PS = 0, 58.2%; 1, 33%); > 2 metastatic sites (51.6%); metastases in liver (79%) or lung (38.8%); were chemotherapy-naïve (54.6%). After baseline actigraphy recording, pts received a median of 8 courses of oxaliplatin- or irinotecan-based chemotherapy, including chronomodulated schedules (chrono; 81.4%). Despite a strong correlation with PS (p< 0.0001), I<O independently influenced both PFS and OS. Thus, both median PFS and OS nearly doubled in the pts with I<O above 97.5% (upper two quartiles) as compared to those with I<O below 93.2% (lowest quartile). Median PFS ranged from 4.8 to 10.6 months (log rank, p<0.001) and median OS from 10.1 to 20.6 months (p<0.001). In multivariate analyses, I<O ranked as the second best independent predictor of PFS, after metastases surgery, with a hazard ratio (HR) of 0.967 [95% C.L., 0.95-0.98] (p<0.001). I<O ranked as first independent predictor of OS, with a HR of 0.95 [0.94-0.97] (p<0.001). Forrest plots revealed consistent HR of I<O for PFS and OS in each cohort.

Conclusions: The circadian biomarker indicator I<O is a robust, consistent and independent quantitative predictor of both PFS and OS in mCRC pts. Rest-activity rhythm monitoring deserves further testing for helping accurate determination of mCRC prognosis. The biological significance of I<O implies that specific treatments of circadian disruption could enhance survival in cancer pts.

National estimate of multiple sclerosis incidence in France (2001–2007)

Background:

In France, the incidence of multiple sclerosis (MS) is not well known, and MS is one of the 30 long-term illnesses for which patients are covered for 100% of their health care costs.

Objective:

To estimate the incidence of MS in France and its geographic variations.

Methods:

We estimated the national rate for notification of MS to the main French health insurance system, and its confidence interval (CI), between November 2000 and October 2007, which covers 87% of the population. We analysed geographic variations using a Bayesian approach.

Results:

Between November 2000 and October 2007, among a covered population of 52,449,871, some 28,682 individuals were registered as having MS. After age standardization according to the European population, the notification rate for MS was 6.8 per 100,000 (6.7–6.9), 9.8 (9.7–10.0) in women and 3.7 (3.6–3.8) in men. When the under-notification rate (11.5% and 29%) was taken into account, the notification rate per 100,000 inhabitants was estimated between 7.6 and 8.8. The notification rate was higher in north-eastern France, and lower on the Atlantic coast and in the Alps as well as on both sides of the Rhône River.

Conclusions:

This study, conducted on a representative French population, provides for the first time national estimates of MS incidence between November 2000 and October 2007.

Statistical power and estimation of incidence rate ratios obtained from BED incidence testing for evaluating HIV interventions among young people

Background

The objectives of this study were to determine the capacity of BED incidence testing to a) estimate the effect of a HIV prevention intervention and b) provide adequate statistical power, when used among young people from sub-Saharan African settings with high HIV incidence rates.

Methods

Firstly, after having elaborated plausible scenarios based on empirical data and the characteristics of the BED HIV-1 Capture EIA (BED) assay, we conducted statistical calculations to determine the BED theoretical power and HIV incidence rate ratio (IRR) associated with an intervention when using BED incidence testing. Secondly, we simulated a cross-sectional study conducted in a population among whom an HIV intervention was rolled out. Simulated data were analyzed using a log-linear Poisson model to recalculate the IRR and its confidence interval, and estimate the BED practical power. Calculations were conducted with and without corrections for misclassifications.

Results

Calculations showed that BED incidence testing can yield a BED theoretical power of 75% or more of the power that can be obtained in a classical cohort study conducted over a duration equal to the BED window period. Statistical analyses using simulated populations showed that the effect of a prevention intervention can be estimated with precision using classical statistical analysis of BED incidence testing data, even with an imprecise knowledge of the characteristics of the BED assay. The BED practical power was lower but of the same magnitude as the BED theoretical power.

Conclusions

BED incidence testing can be applied to reasonably small samples to achieve good statistical power when used among young people to estimate IRR.

Secretory leukocyte protease inhibitor (SLPI) is, like its homologue trappin-2 (pre-elafin), a transglutaminase substrate

Human lungs contain secretory leukocyte protease inhibitor (SLPI), elafin and its biologically active precursor trappin-2 (pre-elafin). These important low-molecular weight inhibitors are involved in controlling the potentially deleterious proteolytic activities of neutrophil serine proteases including elastase, proteinase 3 and cathepsin G. We have shown previously that trappin-2, and to a lesser extent, elafin can be linked covalently to various extracellular matrix proteins by tissue transglutaminases and remain potent protease inhibitors. SLPI is composed of two distinct domains, each of which is about 40% identical to elafin, but it lacks consensus transglutaminase sequence(s), unlike trappin-2 and elafin. We investigated the actions of type 2 tissue transglutaminase and plasma transglutaminase activated factor XIII on SLPI. It was readily covalently bound to fibronectin or elastin by both transglutaminases but did not compete with trappin-2 cross-linking. Cross-linked SLPI still inhibited its target proteases, elastase and cathepsin G. We have also identified the transglutamination sites within SLPI, elafin and trappin-2 by mass spectrometry analysis of tryptic digests of inhibitors cross-linked to mono-dansyl cadaverin or to a fibronectin-derived glutamine-rich peptide. Most of the reactive lysine and glutamine residues in SLPI are located in its first N-terminal elafin-like domain, while in trappin-2, they are located in both the N-terminal cementoin domain and the elafin moiety. We have also demonstrated that the transglutamination substrate status of the cementoin domain of trappin-2 can be transferred from one protein to another, suggesting that it may provide transglutaminase-dependent attachment properties for engineered proteins. We have thus added to the corpus of knowledge on the biology of these potential therapeutic inhibitors of airway proteases.

A pseudo-R2 measure for selecting genomic markers with crossing hazards functions

BACKGROUND

In genomic medical studies, one of the major objectives is to identify genomic factors with a prognostic impact on time-to-event outcomes so as to provide new insights into the disease process. Selection usually relies on statistical univariate indices based on the Cox model. Such model assumes proportional hazards (PH) which is unlikely to hold for each genomic marker.

METHODS

In this paper, we introduce a novel pseudo-R2 measure derived from a crossing hazards model and designed for the selection of markers with crossing effects. The proposed index is related to the score statistic and quantifies the extent of a genomic factor to separate patients according to their survival times and marker measurements. We also show the importance of considering genomic markers with crossing effects as they potentially reflect the complex interplay between markers belonging to the same pathway.

RESULTS

Simulations show that our index is not affected by the censoring and the sample size of the study. It also performs better than classical indices under the crossing hazards assumption. The practical use of our index is illustrated in a lung cancer study. The use of the proposed pseudo-R2 allows the identification of cell-cycle dependent genes not identified when relying on the PH assumption.

CONCLUSIONS

The proposed index is a novel and promising tool for selecting markers with crossing hazards effects.

High-risk syndrome for neuromyelitis optica: a descriptive and comparative study

Background: Neuromyelitis optica (NMO) frequently begins with a monofocal episode of optic neuritis or myelitis. A concept named high-risk syndrome (HRS) for NMO has been proposed for patients with monofocal episodes and NMO-IgG antibodies.

Objective: To describe HRS patients and compare them with NMO patients.

Methods: We identified 30 patients with HRS: 18 with extensive myelitis (HRM) and 12 with optic neuritis (HRON), in a database pooling patients from 25 centres in France. Clinical, laboratory/magnetic resonance imaging (MRI) data and outcome were analysed and compared with a national cohort of 125 NMO patients extracted from the same database.

Results: Mean follow-up was 4.8 years. Mean age at onset was 42.8 years (range: 12.4–70) with a female:male ratio of 0.9. Asymptomatic lesions were report on visual evoked potentials in 4/8 tested HRM patients and on spinal cord MRI in 2/7 HRON patients. Three patients died, two owing to a cervical lesion. HRS and NMO patients had similar clinical/paraclinical data, except for a predominance of men in the HRS group and a later mean age at onset in the HRM subgroup.

Conclusion: The description of HRS patients is compatible with a monofocal form of NMO. Asymptomatic lesions could be included in a new set of NMO diagnostic criteria.

Neuromyelitis optica in France: a multicenter study of 125 patients

BACKGROUND

There have been few epidemiologic studies on neuromyelitis optica (NMO) and none used the recent 2006 diagnostic criteria. Here we describe the clinical, laboratory, MRI, and disability course of NMO in a French cohort of 125 patients.

METHODS

We performed an observational, retrospective, multicenter study. Data were collected from September 2007 through August 2008, corresponding to the endpoint of the study. We identified 125 patients fulfilling the 2006 NMO criteria. Selection was made using hospital files and a specific clinical questionnaire for NMO.

RESULTS

Mean age at onset was 34.5 years (range 4-66) with a mean disease duration of 10 +/- 7.8 years at the endpoint. The patients were mainly (87%) Caucasian, with a female:male ratio of 3:1. In 90% of cases, the association of optic neuritis, longitudinal extensive myelitis, and a Paty-negative initial brain MRI was sufficient to fulfill the supportive criteria. Eighty-eight percent of patients were treated with immunosuppressive therapies. Median delay from onset to Expanded Disability Status Scale (EDSS) score 4 was 7 years; score 6, 10 years; and score 7, 21 years. The first episode of myelitis was immediately followed by an EDSS score > or = 4 in 37.3% of cases, and a severe residual visual loss was observed in 22% of patients after the first episode of optic neuritis. Multivariate analysis did not reveal any predictors of a poor evolution other than a high number of MRI brain lesions at diagnosis, which were predictive of a residual visual acuity < or = 1/10.

CONCLUSIONS

Our demographic data provide new data on disability in patients with neuromyelitis optica, most of whom were receiving treatment.

Identifying common prognostic factors in genomic cancer studies: a novel index for censored outcomes

Background

With the growing number of public repositories for high-throughput genomic data, it is of great interest to combine the results produced by independent research groups. Such a combination allows the identification of common genomic factors across multiple cancer types and provides new insights into the disease process. In the framework of the proportional hazards model, classical procedures, which consist of ranking genes according to the estimated hazard ratio or the p-value obtained from a test statistic of no association between survival and gene expression level, are not suitable for gene selection across multiple genomic datasets with different sample sizes. We propose a novel index for identifying genes with a common effect across heterogeneous genomic studies designed to remain stable whatever the sample size and which has a straightforward interpretation in terms of the percentage of separability between patients according to their survival times and gene expression measurements.

Results

The simulations results show that the proposed index is not substantially affected by the sample size of the study and the censoring. They also show that its separability performance is higher than indices of predictive accuracy relying on the likelihood function. A simulated example illustrates the good operating characteristics of our index. In addition, we demonstrate that it is linked to the score statistic and possesses a biologically relevant interpretation.

The practical use of the index is illustrated for identifying genes with common effects across eight independent genomic cancer studies of different sample sizes. The meta-selection allows the identification of four genes (ESPL1, KIF4A, HJURP, LRIG1) that are biologically relevant to the carcinogenesis process and have a prognostic impact on survival outcome across various solid tumors.

Conclusion

The proposed index is a promising tool for identifying factors having a prognostic impact across a collection of heterogeneous genomic datasets of various sizes.

[Subjective quality of life profile in patients with multiple sclerosis]

OBJECTIVES

This study aimed to assess subjective quality of life in patients with multiple sclerosis regarding the criteria of satisfaction and importance attached to various domains of life.

METHOD

Sixty-one subjects took part in this study. The psychological evaluation consisted of a clinical interview and three questionnaires: subjective quality of life profile (PQVS), State-Trait anxiety inventory (STAI), Beck depression inventory (BDI).

RESULTS

The results show a low level of general satisfaction of subjective quality of life. Fatigue and pain are the most unsatisfactory domains of life while the relationships with close relations and medical staff are perceived as the most satisfactory and important domains of life. Some differences are observed between men and women regarding the satisfaction of conjugal life and fatigue perception. The subjective quality of life seems mainly correlated to anxiety, depression and to the level of handicap.

CONCLUSIONS

Our results emphasize the necessity of taking into account the subjective perception of the disease which can lead in an appropriated treatment. These results underline the place of anxious and depressive disorders associated with multiple sclerosis, which seem to have a certain impact on the subjective quality of life.

Structural characterization of mouse neutrophil serine proteases and identification of their substrate specificities: relevance to mouse models of human inflammatory diseases

It is widely accepted that neutrophil serine proteases (NSPs) play a critical role in neutrophil-associated lung inflammatory and tissue-destructive diseases. To investigate NSP pathogenic role(s), various mouse experimental models have been developed that mimic acutely or chronically injured human lungs. We and others are using mouse exposure to cigarette smoke as a model for chronic obstructive pulmonary disease with or without exacerbation. However, the relative contribution of NSPs to lung disease processes as well as their underlying mechanisms remains still poorly understood. And the lack of purified mouse NSPs and their specific substrates have hampered advances in these studies. In this work, we compared mouse and human NSPs and generated three-dimensional models of murine NSPs based on three-dimensional structures of their human homologs. Analyses of these models provided compelling evidence that peptide substrate specificities of human and mouse NSPs are different despite their conserved cleft and close structural resemblance. These studies allowed us to synthesize for the first time novel sensitive fluorescence resonance energy transfer substrates for individual mouse NSPs. Our findings and the newly identified substrates should better our understanding about the role of NSPs in the pathogenesis of cigarette-associated chronic obstructive pulmonary disease as well as other neutrophils-associated inflammatory diseases.

Estimating the cost related to surveillance of colorectal cancer in a French population

Little is known about costs related to the surveillance of patients that have undergone curative resection of colorectal cancer. The aim of this study was to calculate the observed surveillance costs for 385 patients followed-up over a 3-year period, to estimate surveillance costs if French guidelines are respected, and to identify the determinants related to surveillance costs to derive a global estimation for France, using a linear mixed model. The observed mean surveillance cost was <euro> 713. If French recommendations were strictly applied, the estimated mean cost would vary between <euro> 680 and <euro> 1,069 according to the frequency of abdominal ultrasound. The predicted determinants of cost were: age, recurrence, duration of surveillance since diagnosis, and adjuvant treatments. For France, the surveillance cost represented 4.4% of the cost of colorectal cancer management. The cost of surveillance should now be balanced with its effectiveness and compared with surveillance alternatives.

Maternal blood lead levels and the risk of pregnancy-induced hypertension: the EDEN cohort study

BACKGROUND

Prior studies revealed associations of environmental lead exposure with risks of hypertension and elevated blood pressure.

OBJECTIVE

We examined the effect of blood lead levels on blood pressure and the incidence of pregnancy-induced hypertension (PIH) in the second and third trimesters of pregnancy.

METHODS

One thousand seventeen pregnant women were enrolled in two French municipalities between 2003 and 2005 for the EDEN (Etude des Déterminants pré et post natals du développement et de la santé de l' Enfant) cohort study. Blood lead concentrations were measured by atomic absorption spectrometry in mothers between 24 and 28 weeks of gestation.

RESULTS

PIH was diagnosed in 106 subjects (10.9%). Age, parity, weight gain, alcohol, smoking habits, and calcium supplementation were comparable between hypertensive and nonhypertensive women. Lead levels were significantly higher in PIH cases (mean +/- SD, 2.2 +/- 1.4 microg/dL) than in normotensive patients (1.9 +/- 1.2 microg/dL; p = 0.02). Adjustment for potential confounder effects slightly attenuated but did not eliminate the significant association between blood lead levels and the risk of PIH (adjusted odds ratio of PIH = 3.3; 95% confidence interval, 1.1-9.7). We also observed geographic differences in lead exposure and in the incidence of PIH and found significant correlations between blood lead levels and unadjusted as well as adjusted systolic and diastolic blood pressures after 24 weeks of gestation.

CONCLUSIONS

These findings confirm the relationship between blood lead levels at mid-pregnancy and blood pressure and suggest that environmental lead exposure may play an etiologic role in PIH.

Identification of neutralizing conformational epitopes on the human papillomavirus type 31 major capsid protein and functional implications

The aim of this study was to characterize the conformational neutralizing epitopes of the major capsid protein of human papillomavirus type 31. Analysis of the epitopes was performed by competitive epitope mapping using 15 anti-HPV31 and by reactivity analysis using a HPV31 mutant with an insertion of a seven-amino acid motif within the FG loop of the capsid protein. Fine mapping of neutralizing conformational epitopes on HPV L1 was analyzed by a new approach using a system displaying a combinatorial library of constrained peptides exposed on E. coli flagella. The findings demonstrate that the HPV31 FG loop is dense in neutralizing epitopes and suggest that HPV31 MAbs bind to overlapping but distinct epitopes on the central part of the FG loop, in agreement with the exposure of the FG loop on the surface of HPV VLPs, and thus confirming that neutralizing antibodies are mainly located on the tip of capsomeres. In addition, we identified a crossreacting and partially crossneutralizing conformational epitope on the relatively well conserved N-terminal part of the FG loop. Moreover, our findings support the hypothesis that there is no correlation between neutralization and the ability of MAbs to inhibit VLP binding to heparan sulfate, and confirm that the blocking of virus attachment to the extracellular matrix is an important mechanism of neutralization.

Comparative epidemiology of stroke and acute myocardial infarction: the Dijon Vascular project (Diva)

BACKGROUND

Despite a common pathophysiological mechanism (ie, atherosclerosis) and similar vascular risk factors, few reliable studies have compared the epidemiology of stroke and acute myocardial infarction (AMI).

METHODS

All first ever cases of stroke and AMI in Dijon, France (151 846 inhabitants) from 2001 to 2006 were prospectively recorded. The 30 day case fatality rates (CFRs) and vascular risk factors were assessed in both groups.

RESULTS

Over the 6 years, 1660 events (1020 strokes and 640 AMI) were recorded. Crude incidence of stroke was higher than that of AMI (112 vs 70.2/100 000/year; p<0.001). With regard to sex, the relative incidence of stroke compared with AMI was 0.88 (95% CI 0.60 to 1.29; p = 0.51) in women <65 years and 2.32 (95% CI 1.95 to 2.75; p<0.001) in those >65 years whereas it was 0.60 (95% CI 0.42 to 0.86; p<0.001) in men below 55 years, 1.01 (0.81 to 1.24, p = 0.96) in those between 55 and 75 years and 2.01 (95% CI 1.48 to 2.71; p<0.001) at 75 years and older. CFRs at 30 days were similar for stroke and AMI (9.80% vs 9.84%; p = 0.5). Hyperglycaemia (>7.8 mmol/l) at onset was significantly associated with higher CFR in both stroke and AMI patients. The prevalence of male sex, hypercholesterolaemia and diabetes was higher in AMI patients whereas hypertension was more frequent in stroke patients.

CONCLUSION

These findings will help health care authorities to evaluate future needs for stroke and AMI services, and to develop secondary prevention strategies.

Protease inhibitors derived from elafin and SLPI and engineered to have enhanced specificity towards neutrophil serine proteases

The secretory leukocyte protease inhibitor (SLPI), elafin, and its biologically active precursor trappin-2 are endogeneous low-molecular weight inhibitors of the chelonianin family that control the enzymatic activity of neutrophil serine proteases (NSPs) like elastase, proteinase 3, and cathepsin G. These inhibitors may be of therapeutic value, since unregulated NSP activities are linked to inflammatory lung diseases. However SLPI inhibits elastase and cathepsin G but not proteinase 3, while elafin targets elastase and proteinase 3 but not cathepsin G. We have used two strategies to design polyvalent inhibitors of NSPs that target all three NSPs and may be used in the aerosol-based treatment of inflammatory lung diseases. First, we fused the elafin domain with the second inhibitory domain of SLPI to produce recombinant chimeras that had the inhibitory properties of both parent molecules. Second, we generated the trappin-2 variant, trappin-2 A62L, in which the P1 residue Ala is replaced by Leu, as in the corresponding position in SLPI domain 2. The chimera inhibitors and trappin-2 A62L are tight-binding inhibitors of all three NSPs with subnanomolar K(i)s, similar to those of the parent molecules for their respective target proteases. We have also shown that these molecules inhibit the neutrophil membrane-bound forms of all three NSPs. The trappin-2 A62L and elafin-SLPI chimeras, like wild-type elafin and trappin-2, can be covalently cross-linked to fibronectin or elastin by a tissue transglutaminase, while retaining their polypotent inhibition of NSPs. Therefore, the inhibitors described herein have the appropriate properties to be further evaluated as therapeutic anti-inflammatory agents.

Circadian rhythm in rest and activity: a biological correlate of quality of life and a predictor of survival in patients with metastatic colorectal cancer

The rest-activity circadian rhythm (CircAct) reflects the function of the circadian timing system. In a prior single-institution study, the extent of CircAct perturbation independently predicted for survival and tumor response in 192 patients receiving chemotherapy for metastatic colorectal cancer. Moreover, the main CircAct parameters correlated with several health-related quality of life (HRQoL) scales. In this prospective study, we attempted to extend these results to an independent cohort of chemotherapy-naive metastatic colorectal cancer patients participating in an international randomized phase III trial (European Organisation for Research and Treatment of Cancer 05963). Patients were randomized to receive chronomodulated or conventional infusion of 5-fluorouracil, leucovorin, and oxaliplatin as first-line treatment for metastatic colorectal cancer. Patients from nine institutions completed the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 and wore a wrist accelerometer (actigraph) for 3 days before chemotherapy delivery. Two validated parameters (I<O and r24) were used to estimate CircAct. Of 130 patients with baseline CircAct assessments, 96 had baseline HRQoL data. I<O was confirmed to correlate with global quality of life, physical functioning, social functioning, fatigue, and appetite loss (r > |0.25|; P < 0.01). I<O further independently predicted for overall survival with a hazard ratio of 0.94 (P < 0.0001). The associations between CircAct parameters, HRQoL, and survival, which were shown in this international study involving previously untreated metastatic colorectal cancer patients, confirm prior single-institution findings in mostly pretreated metastatic colorectal cancer patients. The circadian timing system constitutes a novel therapeutic target. Interventions that normalize circadian timing system dysfunction may affect quality of life and survival in cancer patients.

Meta-analysis of gender effect for first-line chronomodulated 5-fluorouracil-leucovorin-oxaliplatin (ChronoFLO) compared with FOLFOX or constant infusion (conventional delivery, CONV) against metastatic colorectal cancer (MCC) in three international controlled phase III randomized trials (RT)

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Background: Gender predicted for the most effective schedule in a RT of ChronoFLO vs CONV against MCC: overall survival (OS) was significantly increased in men on chronoFLO vs FOLFOX, whereas the reverse was found in women (Giacchetti, JCO 2006). Methods: To assess the relevance of gender for patient (pt) outcome, meta-analysis was performed on individual pt data (IPD) from 3 RT in 845 MCC pts treated with chronoFLO vs CONV (346 F, 499 M at 36 centers in 1990–2002)(Lévi, JNCI 1994; Lancet 1997). Data bases were merged and updated at 9 y after inclusion of the 1st pt. Main prognostic factors were comparable in each RT according to gender and treatment arm (median age: 61y; PS=0, 46% pts; liver M, 85% pts; liver involvement >25%, 41% pts; lung M, 37% pts; CEA>10, 56% pts). Results: No significant difference was found according to delivery schedule or gender in the whole population for Response Rate (RR), Progression-Free Survival (PFS) and OS. However, men on chronoFLO had highest RR, longest PFS and OS. PFS and OS were highest in women on CONV ( Table ). The rate of complete macroscopic resections of liver metastases (R0+R1) was 12.5% in men on chronoFLO vs 7.8–8.5% in men on CONV or in women on either schedule. A complete histologic response of liver metastases was documented in 2.1% of the men on chronoFLO vs 0–1.1% in the other groups. The relative risk of an earlier death in men vs women was 0.76 [95% CL, 0.91 to 0.94] on chronoFLO and 1.24 [0.99 to 1.56] on CONV. Conclusions: This IPD meta-analysis of 3 RT in MCC with a minimum follow up of 5 years confirms that men benefit from chronoFLO as compared to CONV delivery, with regard to long term outcome and medico-surgical strategy. ChronoFLO should be preferred to conventional oxaliplatin-5-FU-LV schedules in men with MCC. Support: ARTBC Internationale, P. Brousse Hospital, Villejuif, France.

[Table: see text]

No significant financial relationships to disclose.

[Focal subarachnoid hemorrhage and cerebral amyloid angiopathy: a non-fortuitous association]

INTRODUCTION

Cerebral amyloid angiopathy is a degenerative angiopathy due to amyloid deposits in the walls of the meningeal and cortical vessels. It is considered as a major cause of cerebral hemorrhage to the elderly. It was recently demonstrated that the association of focal meningeal bleedings and cerebral hemorrhage is very suggestive of cerebral amyloid angiopathy. In contrast, the links between subarachnoid hemorrhage and amyloid angiopathy are less well-known.

CASES REPORTS

We report nine cases of cerebral amyloid angiopathy. The clinical presentation was variable, but all had at least one inaugural meningeal bleeding. As cortico-meningeal biopsies were not performed the Boston criteria were used to establish the diagnosis.

CONCLUSION

Cerebral amyloid angiopathy is an underestimated cause of subarachnoid hemorrhage. Our observations show that this diagnosis should be evoked when focal meningeal bleeding occurs without head trauma or when focal subarachnoid hemorrhage is followed by a subcortical hematoma in an elderly subject.

Inflammatory demyelinating events following treatment with anti-tumor necrosis factor

BACKGROUND

Tumor necrosis factor alpha (TNF-alpha) is an inflammatory cytokine involved in certain inflammatory diseases including multiple sclerosis (MS), rheumatoid arthritis (RA), and Crohn's disease. The anti-TNF-alpha treatments used for RA may be associated with inflammatory demyelinating events affecting the central nervous system and may possibly aggravate known MS.

OBJECTIVE

We report here three new cases of inflammatory demyelinating events of the central nervous system following treatment with anti-TNF-alpha.

RESULTS

The neurological symptoms appeared on average 5 months after initiation of the treatment. For all patients, the inflammatory process was confirmed by brain magnetic resonance imaging. The symptoms totally or partially regressed as soon as anti-TNF-alpha treatment was stopped except for one patient who developed clinically defined MS.

CONCLUSIONS

Inflammatory demyelination of the central nervous system may be associated with the use of anti-TNF-alpha. Patients with rheumatoid arthritis treated with these treatments should benefit from a follow-up which includes brain MRI.

Ischaemic stroke subtypes and associated risk factors: a French population based study

BACKGROUND

There is little reliable population based information about the distribution of risk factors among the various ischaemic stroke subtypes, even though determining risk factor profiles is of major importance to develop targeted preventive strategies.

METHODS

The distribution of first ever ischaemic stroke subtypes was established in a prospective population based study conducted in Dijon, France (152,606 inhabitants). Cases were collected between January 2005 and December 2006, and were classified using TOAST classification. Vascular risk factors were recorded to determine a risk factor profile for each subtype.

RESULTS

332 patients with first ever ischaemic stroke (150 men and 182 women) were recorded. Adjusted incidence to world population was 54/100,000/year. The distribution of ischaemic stroke subtypes was as follows: 119 (35.8%) cases of large artery atherosclerosis, 89 (26.8%) small artery occlusions, 81 (24.4%) cardioembolisms and 43 (13%) other and undetermined causes. The most frequent vascular risk factor was hypertension, irrespective of the ischaemic stroke subtype, with a total prevalence of 62%. Using multivariate regression, a positive association between cardioembolism and age (OR 1.051; 95% CI 1.026 to 1.076; p<0.001) was demonstrated and between small artery occlusion and either high blood pressure (OR 1.86; 95% CI 1.06 to 3.27; p = 0.03) or hypercholesterolaemia (OR 2.23; 95% CI 1.33 to 3.76; p = 0.02).

CONCLUSION

This comprehensive prospective population based study has demonstrated that vascular risk factors exhibit a particular distribution according to the ischaemic stroke subtypes. These findings, as well as the great frequency of hypertension among stroke patients, have implications for prevention strategies, the design of clinical trials and the organisation of health care services.

[Stroke in elderly: what have we learned from stroke epidemiology in younger people]

Stroke in the elderly has more major differences compared to young people: it is the first complication of atherothrombosis disease associated with the following risk factors: hypertension, diabetes, hypercholesterolemia, tobacco consumption and sleep apnea syndrome; AVC is the first consequence of atrial fibrillation; from a clinical point of view, seizure at the onset of the stroke is more frequent; prognosis is characterized by a high risk of dementia (20%); primary and secondary prevention is very efficacious even in very old patients, not only on the risk of stroke, but also on the risk of dementia; time trends at Dijon show a slight decrease of incidence rates of stroke only over 85 years, while prevention of stroke has taken advantage of real progress in precocious diagnosis and innovative treatments. In contrast, we observed a decrease of case-fatality rates at any day with a delay in age of onset of stroke, reaching five years in men and eight years in women, suggesting an increase of life expectancy without stroke, reflecting a certain efficacy of prevention.

Clinical parameters to predict response to interferon in relapsing multiple sclerosis

BACKGROUND

To identify clinical parameters of response to beta-interferon (IFN-beta) in relapsing-remitting multiple sclerosis (RRMS) from an East France cohort.

METHODS

Data from 2,645 patients, identified by Burgundy and Lorraine multiple sclerosis (MS) networks, were computerized by a neurologist using the European Database for MS software. Patient inclusion criteria were: clinically or laboratory-supported definite RRMS according to Poser's diagnostic criteria and treatment with IFN-beta for at least 6 months. Four criteria were chosen to predict a response to IFN-beta. The first criterion was any patient who had a lower annualized relapse rate under IFN-beta therapy than during the year preceding treatment; the second criterion was a lower relapse rate than during the 2 years preceding treatment. The third was any patient free of relapse during the first 2 years of IFN-beta therapy. The last criterion concerned the variation in the degree of disability measured by the Disability Status Scale during the first year of treatment. Multivariate logistic regression analyses were performed.

RESULTS

751 RRMS cases were included. A higher relapse rate in the year preceding IFN-beta onset, an older age at MS onset and having a polysymptomatic onset of MS were significantly associated with a response for the first criterion. With the 3 other criteria, no parameter predicting response was identified.

CONCLUSION

Only the relapse rate in the year before initiation of IFN-beta treatment appears to be able to predict response to treatment but not the one of 2 years before.

The adolescent and adult form of cobalamin C disease: clinical and molecular spectrum

BACKGROUND

Cobalamin C disease is the most common inborn error of cobalamin metabolism with an autosomal recessive mode of inheritance and mutations within the MMACHC gene. Clinical features, including systemic, haematological and neurological abnormalities, usually occur in the first year of life. Adolescent and adult onset presentations are rare.

METHODS

We report on the clinical, molecular and imaging features in three patients aged 40, 42 and 42 years at the last follow-up. We examine these cases together with eight previously described cases to determine the clinical and molecular features of the disease in adults.

RESULTS

Mean age at onset of clinical symptoms was 26 years; clinical features included predominant neurological disturbances and thromboembolic complications. White matter abnormalities on brain MRI were sometimes observed. Most patients (eight of nine patients investigated) were compound heterozygotes for the 271dupA mutation and a missense mutation. Intramuscular or intravenous hydroxycobalamin therapy stopped the progression of the disease and resulted in a better clinical outcome and favourable biological status in 7/9 treated cases, while the two untreated patients died quickly.

CONCLUSIONS

As cobalamin C disease and related disorders of homocysteine metabolism are treatable conditions, homocysteinaemia should be included in the investigations of patients with progressive neurological deterioration, unexplained psychiatric disturbances or recurrent thromboembolic events.

The antibacterial and antifungal properties of trappin-2 (pre-elafin) do not depend on its protease inhibitory function

Trappin-2 (also known as pre-elafin) is an endogenous inhibitor of neutrophil serine proteases and is involved in the control of excess proteolysis, especially in inflammatory events, along with the structurally related secretory leucocyte proteinase inhibitor. Secretory leucocyte proteinase inhibitor has been shown to have antibacterial and antifungal properties, whereas recent data indicate that trappin-2 has antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus. In the present study, we tested the antibacterial properties of trappin-2 towards other respiratory pathogens. We found that trappin-2, at concentrations of 5-20 microm, has significant activity against Klebsiella pneumoniae, Haemophilus influenzae, Streptococcus pneumoniae, Branhamella catarrhalis and the pathogenic fungi Aspergillus fumigatus and Candida albicans, in addition to P. aeruginosa and S. aureus. A similar antimicrobial activity was observed with trappin-2 A62D/M63L, a trappin-2 variant that has lost its antiprotease properties, indicating that trappin-2 exerts its antibacterial effects through mechanisms independent from its intrinsic antiprotease capacity. Furthermore, the antibacterial and antifungal activities of trappin-2 were sensitive to NaCl and heparin, demonstrating that its mechanism of action is most probably dependent on its cationic nature. This enables trappin-2 to interact with the membranes of target organisms and disrupt them, as shown by our scanning electron microscopy analyses. Thus, trappin-2 not only provides an antiprotease shield, but also may play an important role in the innate defense of the human lungs and mucosae against pathogenic microorganisms.