[Leptomeningeal dissemination after ethmoidal sinus adenocarcinoma surgery: a rare complication]

INTRODUCTION

Although rare, adenocarcinoma is the most frequent neoplasm of the ethmoid sinus and must be regarded as an occupational disease secondary to chronic wood dust exposure. Few cases with neurological metastasis have been reported.

CASE REPORT

We report the cases of two patients who developed a multiple cranial nerve disorder for the first case and a cauda equina syndrome for the second, after ethmoid adenocarcinoma surgery.

CONCLUSION

Diagnosis of carcinomatous meningitis is difficult and is based on clinical data, CSF analysis and gadolinium-enhanced T1-weighted brain and spinal cord MRI. The implication of surgery is discussed. Prognosis of such a disorder is poor.

A longitudinal observational study of a cohort of patients with relapsing-remitting multiple sclerosis treated with glatiramer acetate

Immunomodulatory treatments for relapsing-remitting multiple sclerosis (RRMS) are not efficacious or tolerated in all patients. It is important to evaluate alternative classes of treatment in patients failing first-line therapy. The objective of this prospective observational study was to evaluate the efficacy and safety of glatiramer acetate in patients, to whom beta-interferons could not be administered. The study included patients with RRMS who were intolerant to or had contraindications to beta-interferon. After initiation of glatiramer acetate treatment, follow-up visits were made every 3 months, when data on neurologist-ascertained relapses and disability [Expanded Disability Status Scale (EDSS) score] were collected. Tolerability was evaluated by spontaneous adverse event reporting. Overall, 205 patients were studied and 113 (55.1%) treated for at least 4 years. The proportion of patients presenting over three relapses per year decreased from 51.2% to 8.4% in the 2 years following treatment initiation. Over 5 years of treatment, mean annualized relapse rates and mean EDSS scores remained stable (0.4-0.6 relapses/year and 3.6 +/- 1.8-3.3 +/- 2.1 respectively). Adverse events were reported by 179 patients, leading to discontinuation of treatment in 10 patients. Patients with RRMS to whom beta-interferons cannot be prescribed can benefit from treatment with glatiramer acetate.

[Lafora's disease presenting with progressive myoclonus epilepsy]

Lafora's disease is a progressive myoclonus epilepsy and must be evocated if myoclonus, occipital seizures and progressive cognitive impairment are present. We report the case of a 14-year-old boy who suffered from several occipital seizures and two generalised seizures. The diagnosis of Lafora's disease was made six years after these inaugural symptoms because of occurrence of myoclonus, aggravation of the epilepsy with paharmacoresistance and psychic deterioration. Axila sweat gland duct biopsy was performed to conclude to the disease. A mutation was found on the gene EPM2A. Lafora's disease is a genetic autosomal-recessive pathology. Two genes have been recently identified. They code for two proteins, malin and laforin, involved in glycogen metabolism in the cellular endoplasmic reticulum. Mutations of these genes are responsible for intracytoplasmic polyglucosan inclusions called Lafora bodies and pathognomonic of the disease.

Multifaceted roles of human elafin and secretory leukocyte proteinase inhibitor (SLPI), two serine protease inhibitors of the chelonianin family

Elafin and SLPI are low-molecular weight proteins that were first identified as protease inhibitors in mucous fluids including lung secretions, where they help control excessive proteolysis due to neutrophil serine proteases (elastase, proteinase 3 and cathepsin G). Elafin and SLPI are structurally related in that both have a fold with a four-disulfide core or whey acidic protein (WAP) domain responsible for inhibiting proteases. Elafin is derived from a precursor, trappin-2 or pre-elafin, by proteolysis. Trappin-2, which is itself a protease inhibitor, has a unique N-terminal domain that enables it to become cross-linked to extracellular matrix proteins by transglutaminase(s). SLPI and elafin/trappin-2 are attractive candidates as therapeutic molecules for inhibiting neutrophil serine proteases in inflammatory lung diseases. Hence, they have become the WAP proteins most studied over the last decade. This review focuses on recent findings revealing that SLPI and elafin/trappin-2 have many biological functions as diverse as anti-bacterial, anti-fungal, anti-viral, anti-inflammatory and immuno-modulatory functions, in addition to their well-recognized role as protease inhibitors.

Relevance of a medicosurgical strategy combining cetuximab and chronomodulated (Chrono) chemotherapy (chemo) with metastases resection as 3rd line treatment for patients (pts) with metastatic colorectal cancer (MCRC)

14505

Background: Metastases surgery offers long tem survival for pts with chemo-downstaged MCRC (Adam et al. Ann Surg 2004). The relevance of this medicosurgical strategy was investigated in pts given cetuximab (Cetux) and Chrono after chemo failure. Methods: 56 pts with progressive MCRC on prior chemo received Cetux (400 mg/m2 on 1st dose then 250 mg/m2/week) and q2w Chrono based on irinotecan (34 pts), oxaliplatin (14 pts) or both (8 pts). Toxicity grades (G) and response were assessed q2w and q8w, respectively. Tumour EGFR was determined by immunohistochemistry (all pts) and gene copies by fluorescence in situ hybridisation (27 pts). Metastases surgery was attempted whenever complete resection was foreseen. Results: Median of 3 prior chemo (1 to 8); median age: 61 years (35 to 79); M/F: 34/22; WHO PS 0/1/2/3: 37/14/4/1; colon/rectum: 32/24; M sites 1/2/=3: 15/22/19; liver/lung: 45/40. EGFR was detected in the tumor of 39 pts (69.6%). 3 pts had G4 allergy. 53 evaluable pts received a median of 5 courses of Cetux-Chrono (1–22). G2–3 acneiform rash occurred in 36 pts (67.8%; G3: 30.4%). Main G3–4 toxicities were diarrhea (26.5%), neutropenia (23.1%) and neuropathy (22.6%). The objective response rate (ORR) was 32% [95% CI, 19.4 to 44.6] (13 PR and 3 CR). ORR was correlated positively with acneiform rash (p= 0.019) but negatively with the detection of EGFR+ tumor cells (0%, ORR=54.5%; 1–10%, 33%; >10%, 16.7%; p = 0.044). No EGFR amplification was documented including 8 OR. Median progression-free survival (PFS) and overall survival were 5.1 [3.2–6.9] and 13.9 months [6.5–21.3] respectively. Metastases surgery was performed in 10 pts (8 R0, 2 R1) after 3–15 courses of Cetux-Chrono as 2nd-5th line. Median PFS in resected pts was 11.7 months [5.8–17.6], with a survival estimate of 80% at 21 months. Conclusions: Cetux-Chrono safely reverted MCRC resistance and allowed successful metastases resection in 17.8% of these pts, like 1st line chemo. This medicosurgical strategy impacted favourably on long term survival, despite its application as 3rd treatment line. Supported by ARTBC, Hôpital Paul Brousse, Villejuif, France

No significant financial relationships to disclose.

Altered circadian rhythm in rest and activity (CircAct): Independent prognostic value for survival in patients (pts) with metastatic colorectal cancer (MCC)

14573

Background: Altered CircAct accelerated tumor growth in experimental models (JNCI 2002, 2005; Cancer Res 2004). CircAct was found to be related to survival in two studies (St) in MCC pts (St 1, Clin Cancer Res 2000; St 2, ASCO 2005 #3553). The current study attempted to provide an independent prognostic stratification criteria for survival according to baseline CircAct as a first step toward the development of a comprehensive prognostic model based on circadian physiology. Methods: CircAct was continuously and non- invasively assessed over 72h with a wrist accelerometer (Ambulatory Monitoring, USA), before chemotherapy in two independent datasets of 169 MCC pts (60% pretreated) at Paul Brousse Hospital (St 1) and 130 chemo-naïve MCC pts registered in the international EORTC 05963 trial (St 2). Activity distribution during rest and wakefulness was objectively quantified by I<O (50=no rhythm; 100=marked rhythm). Kaplan-Meier survival curves with logrank tests and Cox regression models were used for analyses. Results: In both St, pts with I<O = 92 (21% in St 1 and 22% in St 2) displayed a significantly poorer survival as compared to those pts with I<O > 92 (Table). The hazard ratios (HR) were 0.37 [95%CI: 0.25 to 0.55] (p<0.0001) in St 1 and 0.56 [0.36 to 0.87] (p=0.01) in St 2. The prognostic value of altered CircAct persisted after adjusting for PS (HR=0.46 [0.30 to 0.69], p=0.0002 in St 1; HR=0.61 [0.38 to 0.97], p=0.04 in St 2). Conclusions: The independent stratification of MCC pts for survival according to baseline altered CircAct occurred using a threshold value of 92 for I<O in both separate datasets. Subsequent studies will involve additional biomarkers of circadian physiology (cortisol, melatonin, clock genes) in order to further improve this prognostic stratification as a step toward tailored treatment of MCC pts.

[Table: see text]

No significant financial relationships to disclose.

Hepatitis B vaccination and first central nervous system demyelinating events: reanalysis of a case-control study using the self-controlled case series method

The hypothesis that hepatitis B vaccination is a risk factor for multiple sclerosis has been discussed at length. The data from an earlier case-control study were reanalyzed using the self-controlled case series method. Using the matched cases from the case-control study, we found a relative incidence of 1.68, 95% CI (0.77-3.68) for the 0-60-day post-vaccination risk period; this compares to an odds ratio of 1.8, 95% CI (0.7-4.6). When an additional 53 unmatched cases not used in the case-control study were included, the relative incidence was 1.35, 95% CI (0.66-2.79). Our results throw further light on the methodological aspects of the case series method. We recommend that, when case-control studies of vaccination and adverse events are planned, case series analyses based on the cases are also undertaken when appropriate.

Relative-risk ratio was a useful measure of differential association in cohort and case-series studies

OBJECTIVE

The framework consists of cohort or case-series studies with intermittent exposure and two types of events. The aim is to define and estimate an association measure between the exposure and the occurrence of one type of event rather than the other.

STUDY DESIGN AND SETTING

The model and the estimation method are obtained by extending Farrington's approach for one type of recurrent event. The proposed association measure "RR(c)" is the ratio of the relative risks pertaining to each type of event. The estimated RR(c) and its confidence interval are derived under the independence assumption between the counts of the two types of events. The data that are analyzed are part of the data of a study on antimicrobial resistance in children.

RESULTS

An interpretation of the RR(c) is proposed in terms of an odds ratio, which parallels a similar association measure defined in cross-sectional studies ("OR(c)"). The estimated value of the RR(c) agrees with the OR(c) reported in previous studies.

CONCLUSION

The RR(c) appears as a useful tool for evaluating the risk of colonization (or infection) with resistant rather than susceptible bacteria following a previous intake of a given antibiotic conditional on colonization (or infection) with any bacteria.

Disability evolution in multiple sclerosis: how to deal with missing transition times in the Markov model?

Markov modeling of disability progression in multiple sclerosis requires knowledge of all times of transitions from a given level of disability to the next level, but such data are often missing. We address methodological challenges due to partly missing transition times. To estimate the effects of prognostic factors on the risk of transitions between three consecutive disability levels, two methods were used to deal with missing data. Listwise deletion limited the analysis to subjects with complete data. Multiple imputation of missing data revealed that data were missing at random (MAR mechanism) and imputed the missing transition times from the Weibull model. The results were then compared with the full data set with the actual times established through chart review. Multiple imputation estimates were systematically closer to those from the full data set than the listwise deletion estimates.

Influence of Charge Distribution at the Active Site Surface on the Substrate Specificity of Human Neutrophil Protease 3 and Elastase

The biological functions of human neutrophil protease 3 (Pr3) differ from those of neutrophil elastase despite their close structural and functional resemblance. Although both proteases are strongly cationic, their sequences differ mainly in the distribution of charged residues. We have used these differences in electrostatic surface potential in the vicinity of their active site to produce fluorescence resonance energy transfer (FRET) peptide substrates for investigating individual Pr3 subsites. The specificities of subsites S5 to S3' were investigated both kinetically and by molecular dynamic simulations. Subsites S2, S1', and S2' were the main definers of Pr3 specificity. Combinations of results for each subsite were used to deduce a consensus sequence that was complementary to the extended Pr3 active site and was not recognized by elastase. Similar sequences were identified in natural protein substrates such as NFkappaB and p21 that are specifically cleaved by Pr3. FRET peptides derived from these natural sequences were specifically hydrolyzed by Pr3 with specificity constants k(cat)/K(m) in the 10(6) m(-1) s(-1) range. The consensus Pr3 sequence may also be used to predict cleavage sites within putative protein targets like the proform of interleukin-18, or to develop specific Pr3 peptide-derived inhibitors, because none is available for further studies on the physiopathological function of this protease.

[Finnish amyloid polyneuropathy in a French patient]

INTRODUCTION

Finnish amyloid variety is a rare familial amiloidosis polyneuropathy essentially observed in Finland. It concerns about six hundred people in the world in which five hundred reside in Finland.

OBSERVATION

We report a case of a 58-year-old French woman with a 10-year history of lattice cornea dystrophy. She consulted in January 2004 for impaired swallowing, facial paralysis principally of the right superior territory and symptoms of arthritis which had developed a few months earlier. Observation revealed facial cutis laxa, tongue amyotrophy and some fasciculation. Electroneuromyography showed chronic neurogenic involvement of the facial muscles. Limbs and the sympathetic neuronal system were free of involvement. Pathological examination revealed areas of peri vascular amiloid deposits. Molecular biology confirmed the diagnosis of Finnish amiloidosis: substitution of aspartic acid by tyrosine in the 187 codon in the 9th chromosome (gelsoline gene). This mutation has been previously found in Denmark and the Czech Republic.

CONCLUSION

Finnish amiloidosis is a familial polyneuropathy characterized by an association of cornea lattice dystrophy, cutis laxa and a chronic neurogenic involvement of the cranial nerves. Two mutations are known. Life expectancy is not affected, but quality of life is altered.

Apport de l’évaluation écologique des troubles exécutifs dans la sclérose en plaques

INTRODUCTION

Multiple sclerosis (MS) is a major cause of neurological disability among young adults. The cognitive disorders are the second cause of alteration of quality of life after physical handicap and are often responsible for loss of social-occupational adaptability. The prevalence of cognitive disorders is 40 to 65%. The alteration of executive functions predominates whereas instrumental functions are generally preserved. The assessment of these disorders is often underestimated by the usual battery of neuropsychological tests. However, the link between psychometric results and executive difficulties of daily life is uncertain.

OBJECTIVES

To evaluate the sensitivity of an ecological test compared to standard psychometric tests in assessment of executive disorders in MS.

METHODS

Twenty subjects with clinically definite MS were matched for age, sex and pre-morbid intellectual level with control subjects. A battery of neuropsychological and ecological tests was applied to all subjects. The performances on these tests formed a global score of executive function (SFE). The "paper and pencil" multiple errands test was used as the ecological test to examine planning and goal-oriented behavior. We also assessed fatigue and depression with the Fatigue Severity Scale and the Beck Depression Inventory.

RESULTS

There was no significant differences between MS patients and controls in neuropsychological executive tests, except for verbal fluencies (p=0.01). The performances were significantly decreased in the MS group for the multiple errands test (p=0.01). 75% of MS subjects have a pathological score for this test. There was a significant link between the performances with this test and SFE (p=0.009).

CONCLUSIONS

Executive disorders are underestimated in MS. However, we suggest that an ecological approach is more reliable than standard neuropsychological tests to estimate the cognitive difficulties in daily life in MS subjects. The results of our study favor further research to ascertain the usefulness of ecological assessment in MS.

The Prognostic Value of Initial Relapses on the Evolution of Disability in Patients with Relapsing-Remitting Multiple Sclerosis

The evolution of multiple sclerosis (MS) and the resulting disability are unpredictable. To identify clinical variables that could be potential prognostic factors, we followed a cohort of 288 patients diagnosed as having relapsing-remitting MS between 1990 and 2003. The end point was the first occurrence of a non-reversible EDMUS-GS score >or=3 (moderate disability). The impact of the number of MS attacks during the first 2 years of the disease as well as the first interattack interval were assessed in two Cox models, one using a fixed-in-time covariate, the other using a time-dependent covariate. Older age at onset and a higher number of MS attacks during the first 2 years of MS proved to be predictors of unfavourable prognosis. The first interattack interval had no influence on the evolution of the disability, conversely to the first relapse which had a short-term impact on the prognosis. We confirmed that the age at onset and the number of MS attacks during the first 2 years of MS are predictors of the evolution of the disability and demonstrated the importance of using time-dependent covariates.

Elafin and its precursor trappin-2 still inhibit neutrophil serine proteinases when they are covalently bound to extracellular matrix proteins by tissue transglutaminase

Elafin and its precursor trappin-2 (also called pre-elafin) are potent protein inhibitors of neutrophil serine proteases such as leukocyte elastase and proteinase 3. Trappin-2 has unique conserved sequence motifs rich in Gln and Lys residues. These motifs are substrates for transglutaminases that may enable trappin-2 to be cross-linked to extracellular matrix proteins, thus anchoring the inhibitor at its site of action. We have used Western blotting and ELISA-based assays to demonstrate that both elafin and trappin-2 can be conjugated to various extracellular matrix proteins in vitro by a type 2 transglutaminase. Cross-linked elafin and trappin-2 still inhibited their target proteases. Surface plasmon resonance studies allowed the determination of the kinetic constants governing the interaction of fibronectin-bound elafin and trappin-2 with neutrophil elastase and proteinase 3. Both inhibitors were potent inhibitors when cross-linked to fibronectin by transglutamination, with equilibrium dissociation constants K(i) for their interaction with target proteases of 0.3 nM (elastase-elafin), 20 nM (proteinase 3-elafin), 0.3 nM (elastase-trappin-2), and 12 nM (proteinase 3-trappin-2). The conjugated inhibitors reacted more slowly with their target enzymes than did the soluble inhibitors, perhaps due to their immobilization, with association rate constants of 2-7 x 10(5) M(-)(1) s(-)(1) for elastase and 1-4 x 10(4) M(-)(1) s(-)(1) for proteinase 3. We believe this is the first demonstration that transglutaminase-mediated cross-linking of serine protease inhibitors to proteins preserves their inhibitory capacities.

Effect of maternal manganese blood levels on erythrocyte calcium-pump activity in newborns

Manganese (Mn) is widely distributed in the biosphere but occurs in only trace amounts in animal tissues. Although Mn deficiency and toxicity both have pathological consequences, the underlying biochemical lesions have not been well defined. In vitro studies suggest that transport proteins are affected by Mn, lead (Pb), and selenium (Se). Among these transport proteins, the calmodulin-regulated calcium pump (Ca(2+)Mg(2+)ATPase) could be inhibited by Mn. In order to understand Mn biochemical pathways, we examined the relationships between Mn blood levels and red blood cell Ca-pump activity among 248 mothers and newborns, environmentally exposed to Mn, Pb, and Se.

POPULATION AND METHODS

248 mother-newborn pairs were recruited at Robert Debré University Hospital (Paris). Blood Mn and Pb concentrations were measured by absorption spectrophotometry. Se was measured by fluorometric method. Red blood cell membrane suspensions were obtained for Ca-pump activity measurements. Linear and quadratic regression models and Pearson correlation were performed.

RESULTS

A non-linear parabolic relationship between maternal Mn blood levels and newborn Ca-pump activity was discovered from the analysis of the observed data. The peak level of maternal Mn that corresponded to a maximal activity of the newborn Ca-pump was estimated at 23.9 microg/l with a 95% confidence interval of 17.6 to 32.4 microg/l. An inhibition of this enzyme was observed at low and high levels of maternal Mn. The relationships between the newborn Ca-pump activity and maternal Se and Pb levels became non-significant after adjustment on all the co-factors included in the final model.

CONCLUSION

Maternal environmental exposure to Mn, as reflected by maternal blood levels of this metal, is associated with a reduced activity of newborn erythrocyte Ca-pump in a non-linear pattern. Mn levels between 17.6 and 32.4 microg/l in maternal blood probably correspond to the optimal physiological concentration for the metabolism of this enzyme in newborns.

Comparaison de l’immunofixation après électrophorèse sur gel d’agarose avec la focalisation isoélectrique dans la détection des bandes oligoclonales d’IgG du liquide céphalo-rachidien de patients atteints de sclérose en plaques

INTRODUCTION

Intrathecal immunoglobulins (Ig) synthesis, reflected by oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) is observed in up to 90 percent of patients with clinically definite Multiple Sclerosis (MS). The gold standard laboratory test to establish the presence of OCBs in CSF of MS patients is isoelectric focusing (IEF). However, a quicker and less expensive method has been developed: immunofixation (IF).

METHODS

The aim of this study was to compare these two methods carried out 74 CSF/serum pairs of MS, 103 CSF/serum pairs of subject controls and to determine their sensitivity and specificity.

RESULTS

The agreement between results from IEF and IF was excellent (Kappa = 0.84). IEF sensitivity (78 percent) was not significantly different from that of IF (74 percent) (p = 0.3). Similarly, the specificity of IEF (93 percent) was not significantly different from that of IF (95 percent) (p = 0.2).

CONCLUSION

IF is a semi automated method which is easier to perform than IEF and which appears to be as efficient as IEF.

Oxidized elafin and trappin poorly inhibit the elastolytic activity of neutrophil elastase and proteinase 3

Neutrophil proteinase-mediated lung tissue destruction is prevented by inhibitors, including elafin and its precursor, trappin. We wanted to establish whether neutrophil-derived oxidants might impair the inhibitory function of these molecules. Myeloperoxidase/H(2)O(2) and N-chlorosuccinimide oxidation of the inhibitors was checked by mass spectrometry and enzymatic methods. Oxidation significantly lowers the affinities of the two inhibitors for neutrophil elastase (NE) and proteinase 3 (Pr3). This decrease in affinity is essentially caused by an increase in the rate of inhibitory complex dissociation. Oxidized elafin and trappin have, however, reasonable affinities for NE (K(i) = 4.0-9.2 x 10(-9) M) and for Pr3 (K(i) = 2.5-5.0 x 10(-8) M). These affinities are theoretically sufficient to allow the oxidized inhibitors to form tight binding complexes with NE and Pr3 in lung secretions where their physiological concentrations are in the micromolar range. Yet, they are unable to efficiently inhibit the elastolytic activity of the two enzymes. At their physiological concentration, fully oxidized elafin and trappin do not inhibit more than 30% of an equimolar concentration of NE or Pr3. We conclude that in vivo oxidation of elafin and trappin strongly impairs their activity. Inhibitor-based therapy of inflammatory lung diseases must be carried out using oxidation-resistant variants of these molecules.

Proteolytic susceptibility of the serine protease inhibitor trappin-2 (pre-elafin): evidence for tryptase-mediated generation of elafin

A number of serine, cysteine, metallo- and acid proteases were evaluated for their ability to proteolytically cleave the serine protease inhibitor trappin-2, also known as pre-elafin, and to release elafin from its precursor. None of the metalloproteases or acid proteases examined cleaved trappin-2, while serine and cysteine proteases preferentially cleaved trappin-2 within its non-inhibitory N-terminal moiety. Cathepsin L, cathepsin K, plasmin, trypsin and tryptase were able to release elafin by cleaving the Lys 38 -Ala 39 peptide bond in trappin-2. However, purified tryptase appeared to be efficient at releasing elafin. Incubation of trappin-2 with purified mast cells first challenged with anti-immunoglobulin E or calcium ionophore A23187 resulted in the rapid generation of elafin. This proteolytic release of elafin from trappin-2 was inhibited in the presence of a tryptase inhibitor, suggesting that this mast cell enzyme was involved in the process. Finally, ex vivo incubation of trappin-2 with sputum from cystic fibrosis patients indicated the production of a proteolytic immunoreactive fragment with the same mass as that of native elafin. This cleavage did not occur when preincubating the sputum with polyclonal antibodies directed against tryptase. Taken together, these findings indicate that tryptase could likely be involved in the maturation of trappin-2 into elafin under physiological conditions.

Modafinil for fatigue in MS: A randomized placebo-controlled double-blind study

OBJECTIVE

To assess whether modafinil, a wakefulness-promoting agent, is useful for fatigue in patients with multiple sclerosis (MS).

METHODS

Patients with MS with stable disability, and a baseline score of 45 or more on the Modified Fatigue Impact Scale (MFIS), were eligible for the 5-week randomized, double-blind, placebo-controlled, parallel group study. The initial daily dose of modafinil was 200 mg for 1 week. Depending on tolerance, the dose was increased by 100 mg every week up to 400 mg/day and remained unchanged between day 21 and day 35. The primary outcome variable was the change of MFIS score at day 35.

RESULTS

A total of 115 patients with MS were enrolled in the study and in the intention to treat analysis. The mean MFIS score at baseline was 63 +/- 9 in the placebo group and 63 +/- 10 in the modafinil group. MFIS scores improved between day 0 and day 35 in both placebo-treated and modafinil-treated groups, but no significant difference was detected between the two groups. There was no major safety concern.

CONCLUSIONS

There was no improvement of fatigue in patients with multiple sclerosis treated with modafinil vs placebo according to the Modified Fatigue Impact Scale.

Testing independence between two Poisson-generated multinomial variables in case-series and cohort studies

In case-series or cohort studies, we propose a test of independence between the occurrences of two types of recurrent events (such as two repeated infections) related to an intermittent exposure (such as an antibiotic treatment). The test relies upon an extension of a recent method for analysing case-series data, in the presence of one type of recurrent event. The test statistic is derived from a bivariate Poisson generated-multinomial distribution. Simulations for checking the validity of the test concerning the type I error and the power properties are presented. The test is illustrated using data from a cohort on antibiotics bacterial resistance in schoolchildren.

Expression and recombination of the EGFP and EYFP genes in lentiviral vectors carrying two heterologous promoters

BACKGROUND

Expressing two genes in the progeny of stem and progenitor cells that are transduced with a unique viral vector is desirable in certain situations. We tested the ability of two lentiviral vectors to transduce human cells of hematopoietic origin and concomitantly express two reporter genes, either EGFP (enhanced green fluorescent protein) and DsRed2, or EGFP and EYFP (enhanced yellow fluorescent protein), from two internal promoters.

METHODS

The vectors were generated from the pTRIP deltaU3 EF1alpha EGFP lentiviral vector. Following transduction of hematopoietic and non-hematopoietic cell lines, we performed FACS, PCR and Southern blot analyzes to quantify transduction, integration efficiencies and size of integrated lentiviral vectors, respectively.

RESULTS

The detection of DsRed2 fluorescence appeared unexpectedly low in human cells of hematopoietic origin. Alternatively, a modification in the flow cytometry assay allowed us to distinguish between the two overlapping fluorescence signals emitted by EGFP and EYFP, when transduced cells were excited with a 488-nm laser beam. However, the low frequency of double-positive EGFP+ EYFP+ cells, and the existence of single-positive, mostly EGFP- EYFP+, cells, prompted us to search for recombinations in the vector sequence. Southern blotting of DNA obtained from transduced cells indeed demonstrated that recombination had occurred between the two closely related EGFP and EYFP sequences.

DISCUSSION

These observations suggest that recombination occurred within the EGFP and EYFP genes, which differ by only four amino acids. We conclude that the insertion of two highly homologous sequences into a lentiviral backbone can favor recombination.

Procédures de comparaisons multiples : principes et limites Applications à l’étude différentielle de l’expression transcriptionnelle par puces à ADN

BACKGROUND

When analysing data which simultaneously implicate a large number of statistical tests, one of the main problems is to take into account the multiplicity of these tests. The huge amount of comparisons done in studies of which the aim is to detect, using microarray, genes whose transcriptional changes are related to a biological or clinical outcome leads to a renewed interest for the multiple comparisons problem. However, this problem concerns many other fields such as psychometry, epidemiology, genetics.

RESULTS

First, we introduce the multiple comparison framework. Then, we present the main procedures based on a global error rate called the "Family Wise Error Rate" (FWER) and those based on a false discovery rate expectancy (the "False Discovery Rate" (FDR) and the "positive False Discovery Rate" (pFDR)). Next, we apply the different procedures on a real dataset from a breast carcinoma study. Finally, we discuss the main results and we present guidelines for the use of these procedures.

A simple procedure for estimating the false discovery rate

MOTIVATION

The most used criterion in microarray data analysis is nowadays the false discovery rate (FDR). In the framework of estimating procedures based on the marginal distribution of the P-values without any assumption on gene expression changes, estimators of the FDR are necessarily conservatively biased. Indeed, only an upper bound estimate can be obtained for the key quantity pi0, which is the probability for a gene to be unmodified. In this paper, we propose a novel family of estimators for pi0 that allows the calculation of FDR.

RESULTS

The very simple method for estimating pi0 called LBE (Location Based Estimator) is presented together with results on its variability. Simulation results indicate that the proposed estimator performs well in finite sample and has the best mean square error in most of the cases as compared with the procedures QVALUE, BUM and SPLOSH. The different procedures are then applied to real datasets.

AVAILABILITY

The R function LBE is available at http://ifr69.vjf.inserm.fr/lbe

CONTACT

broet@vjf.inserm.fr.

Kinetics of the inhibition of neutrophil proteinases by recombinant elafin and pre-elafin (trappin-2) expressed in Pichia pastoris

Elafin and its precursor, trappin-2 or pre-elafin, are specific endogenous inhibitors of human neutrophil elastase and proteinase 3 but not of cathepsin G. Both inhibitors belong, together with secretory leukocyte protease inhibitor, to the chelonianin family of canonical protease inhibitors of serine proteases. A cDNA coding either elafin or its precursor, trappin-2, was fused in frame with yeast alpha-factor cDNA and expressed in the Pichia pastoris yeast expression system. Full-length elafin or full-length trappin-2 were secreted into the culture medium with high yield, indicating correct processing of the fusion proteins by the yeast KEX2 signal peptidase. Both recombinant inhibitors were purified to homogeneity from concentrated culture medium by one-step cationic exchange chromatography and characterized by N-terminal amino acid sequencing, Western blot and kinetic studies. Both recombinant elafin and trappin-2 were found to be fast-acting inhibitors of pancreatic elastase, neutrophil elastase and proteinase 3 with k(ass) values of 2-4 x 10(6) m(-1).s(-1), while dissociation rate constants k(diss) were found to be in the 10(-4) s(-1) range, indicating low reversibility of the complexes. The equilibrium dissociation constant K(i) for the interaction of both recombinant inhibitors with their target enzymes was either directly measured for pancreatic elastase or calculated from k(ass) and k(diss) values for neutrophil elastase and proteinase 3. K(i) values were found to be in the 10(-10) molar range and virtually identical for both inhibitors. Based on the kinetic parameters determined here, it may be concluded that both recombinant elafin and trappin-2 may act as potent anti-inflammatory molecules and may be of therapeutic potential in the treatment of various inflammatory lung diseases.

[Alien hand syndrome due to a corpus callosum infarct: a case report]

A 64-year-old man with alien hand syndrome presented with abnormal feelings in the left upper limb, associated with an intermanual conflict. There were no clinical signs of frontal or parietal apraxia. This syndrome was induced by an infarct localized in the right posterior area of the splenium, subsequent to a cardiogenic embolus. This observation enlightens the rising syndrome of callosal type alien syndrome due to a posterior callosal infarct.

Two-sample statistics for testing the equality of survival functions against improper semi-parametric accelerated failure time alternatives: an application to the analysis of a breast cancer clinical trial

This paper presents two-sample statistics suited for testing equality of survival functions against improper semi-parametric accelerated failure time alternatives. These tests are designed for comparing either the short- or the long-term effect of a prognostic factor, or both. These statistics are obtained as partial likelihood score statistics from a time-dependent Cox model. As a consequence, the proposed tests can be very easily implemented using widely available software. A breast cancer clinical trial is presented as an example to demonstrate the utility of the proposed tests.

Design and Use of Highly Specific Substrates of Neutrophil Elastase and Proteinase 3

We have exploited differences in the structures of S2' subsites of proteinase 3 (Pr3) and human neutrophil elastase (HNE) to prepare new fluorogenic substrates specific for each of these proteases. The positively charged residue at position 143 in Pr3 prevents it from accommodating an arginyl residue at S2' and improves the binding of P2' aspartyl-containing substrates, as judged by the decreased K(m). As a result, the k(cat)/K(m) for Abz-VADCADQ-EDDnp is over 500 times greater for Pr3 than for HNE, and that for Abz-APEEIMRRQ-EDDnp is over 500 times greater for HNE than for Pr3. This allows each protease activity to be measured in the presence of a large excess of the other, as might occur in vivo. Placing a prolyl residue in position P2' greatly impaired substrate binding to both HNE and Pr3, which further emphasizes the importance of S' subsites in these proteases. HNE and Pr3 activities were measured with these substrates at the surface of fixed polymorphonuclear leukocytes (PMNs) before and after activation. This demonstrated that their active site remains accessible when they are exposed to the cell surface. Both membrane-bound proteases were strongly inhibited by low M(r) serine protease inhibitors, but only partially by inhibitors of larger M(r) such as alpha1-protease inhibitor, the main physiologic inhibitor in lung secretions. Most of membrane-bound HNE and Pr3 can be released from the membrane surface of fixed cells by a buffer containing detergent, suggesting that hydrophobic interactions are involved in membrane binding.

Quality of life after complicated elective surgery requiring intensive care

OBJECTIVE

To evaluate outcomes of patients admitted to the ICU for complications after elective surgery and to assess perceived quality of life (pQOL) in survivors.

DESIGN

Two-year prospective case-control study.

SETTING

Twelve-bed ICU in a university-affiliated hospital.

PATIENTS

Patients admitted to the ICU for a complication following elective surgery were included. Six months after discharge, pQOL was assessed using the Nottingham Health Profile (NHP). Results were compared to those of matched controls without complications.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Of the 182 patients, 124 were alive after 6 months, among whom 116 had 6-month data and 104 of these had matched controls. Overall pQOL as assessed by the global NHP score was similar in both groups (median, 0.82 and 0.87 in cases and controls; P=0.24). NHP subscores showed significantly worse pain ( P=0.03) and physical impairment ( P=0.02) in the ICU patients. In the multivariate analysis, pQOL was better in patients with cancer as the reason for surgery ( P=0.05). Severity of illness at inclusion had no influence on subsequent pQOL, but cardiovascular dysfunction was associated with decreased energy ( P=0.04).

CONCLUSIONS

Although overall pQOL was satisfactory after 6 months, patients admitted to the ICU for postoperative complications had worse pain and physical impairment than controls. Whether these outcomes could be improved by early physiotherapy and aggressive pain management deserves investigation.

Variation saisonnière des accidents vasculaires cérébraux et influence des conditions météorologiques

The aim of this paper was to study the seasonal and Monthly distribution of different subtypes of strokes, and also the influence of the most usual meteorological factors on their incidence. The study, based on the population-based data of the Dijon register of stroke (France), involved 3287 patients with a cerebrovascular event during the Years 1985-1998. The seasonal distribution pointed out a summer decrease for all stroke subtypes. The cerebrovascular risk was the highest in autumn for small artery atheroma infarcts and for cerebral infarcts and, among these later, for cardioembolic infarcts and large artery atheroma infarcts, as well as for subarachnoid hemorrhages and for the total number of strokes. It was followed by spring (total number of strokes, small artery atheroma infarcts, cerebral infarcts) and/or winter (subarachnoid hemorrhages, cerebral infarcts, cardioembolic infarcts and large artery atheroma infarcts). For intracerebral hemorrhages, the risk peaked in spring and secondly in autumn. But the difference from one season to another was significant only for total number of strokes, cerebral infarcts and, among the later, for cardioembolic infarcts and large artery atheroma infarcts. As regards the Monthly distribution, the difference between Months was significant only for the total number of strokes and cerebral infarcts, with a minimum from July to September and a maximum in October for the later. Correlations with meteorological data were found for the total number of strokes, cerebral infarcts, cardioembolic infarcts, large artery atheroma infarcts and small artery atheroma infarcts. They showed an influence of temperature and relative humidity of the day of stroke or of the one to five days before. Correlations with wind speed, duration of sunshine or snow, even if less frequent, could also be found. Such results sometimes differ from those of some earlier studies, for which the climate and the risk factors were not the same, showing that regional epidemiological studies are necessary in order to determine the relations between seasons, meteorological factors and strokes.

Porcine CD58: cDNA cloning and molecular dissection of the porcine CD58-human CD2 interface

The porcine ligands of human CD2 remain unknown in xenotransplantation despite being an important pathway of T cell costimulation. Of the two main candidates, i.e., CD48 and CD58, the cDNA of the most likely ligand poCD58 was cloned from CD48-negative endothelial cells costimulating human CD4(+) T cells through the CD2 pathway. The deduced protein sequence is 244 residues long and is 43% homologous to the human sequence. Based on similarity between porcine and human CD58 external V-set Ig-type domains, a structural model of poCD58-huCD2 interaction was built. Most of the charged residues located at the interface with huCD2 are highly conserved. Six putative hydrogen bonds between poCD58 and huCD2 were identified; five involve the same residues as in the syngeneic combination while the sixth is formed between an additional tyrosine in poCD58 and Arg48 in huCD2, increasing the complementarity between the two molecules. These structural data will help us to develop poCD58 blocking agents for xenotransplantation.

[Epidemiology of hemorrhagic strokes]

Hemorrhagic stroke (HS) may be secondary to spontaneous intracerebral hemorrhage or to subarachnoid hemorrhage. There are no clinical symptoms that differentiate hemorrhagic stroke form ischemic stroke (IS) and only imaging can make the difference. But epidemiology, pathologic process and management are different in HS and IS. We will discuss the different risk factors of spontaneous intracerebral hemorrhage and subarachnoid hemorrhage.

[Spontaneous hyperdense intracranial vessels seen on CT scan in polycythemia cases]

PURPOSE

A better understanding of the significance of diffuse hyperdensity affecting the circle of Willis and the dural sinuses on unenhanced CT.

MATERIALS AND METHODS

We performed a retrospective study of 19 patients with a neurological manifestation and a CT scan without contrast injection. Among these 19 patients, six had been included because of primary or secondary polycythemia. The analysis of cerebral CT scans was made qualitatively by visual inspection and quantitatively.

RESULTS

In patients with a hematocrit percentage exceeding 60%, both circle of Willis and dural sinuses were dense on unenhanced CT scans. A linear relation between the hemoglobin level and the contrast of the dural sinuses compared with the grey matter was observed with an excellent correlation (r = 0.934; n < 0.0001; p = 19).

CONCLUSION

Increased density of cerebral vessels on unenhanced CT is a sign of a high hemoglobin level.

Oligodendrocyte myelin glycoprotein growth inhibition function requires its conserved leucine-rich repeat domain, not its glycosylphosphatidyl-inositol anchor

The oligodendrocyte myelin glycoprotein (OMgp) inhibits neurite outgrowth and axonal regeneration after brain injury, but its normal function remains unknown. Several observations suggest its implication in cell growth regulation. Here we report an analysis of the domain requirement in OMgp proliferation inhibitory function. We first studied the OMgp protein sequence in 14 mammal species and observed a high conservation of its leucine-rich repeat (LRR) domain. The deletion of this LRR domain is responsible for a total loss of function in an in vitro expression system. The possible three-dimensional structure of the LRR domain of OMgp was modelled using the structure of Yersinia pestis YopM cytotoxin as a template. The predicted arrangement of the LRR segments is compatible with a function of OMgp as a binding protein. The OMgp is a glycosylphosphatidyl-inositol-linked protein anchored in the plasma membrane of oligodendrocytes and neurones. Using deletion mutagenesis, we demonstrated the dispensability of the glycosylphosphatidyl-inositol anchor for OMgp proliferation inhibition function. Our results suggest that OMgp is part of a receptor complex, either as a coreceptor or as a membrane-bound or soluble ligand, involved in the transmission of a growth suppressive signal.

A score test for establishing non-inferiority with respect to short-term survival in two-sample comparisons with identical proportions of long-term survivors

In recent years randomized trials designed to establish non-inferiority of a new treatment as compared to a standard one have been more widely used. Two-sample statistics have been proposed for this equivalence testing problem. However, they are not suited to situations where a long-term survivor fraction is expected. In this paper we propose a score test designed for establishing non-inferiority for the new treatment as compared to the standard one while assuming identical long-term survivor rates. Simulations results show that the proposed statistic has satisfactory size and power as long as certain restricting conditions are verified. A breast cancer trial is analysed as an example.

[Gustatory disorders during multiple sclerosis relapse]

Gustatory dysfunction is a known but uncommon element in the course of multiple sclerosis. Gustatory dysfunction has been described during the chronic progressive phase and during the relapse phase. We report five patients with clinically definite multiple sclerosis who developed transient gustatory disorders during the relapse phase of their disease. Agueusia occurred as one of the first symptoms in three patients, revealing the disease. Symptoms generally improved with remission or corticosteroid administration. These disorders are due to demyelinating lesions of the gustatory pathways in the thalamus or brainstem. MRI studies were not performed during the relapse phase and no clinical neuroimaging correlations could be established. Agueusia may be accompanied by olfactory dysfunction which is due to plaque demyelinization of the olfactory pathways, particularly in the temporal and inferior frontal lobes. Taste anomalies can also be observed in other diseases, including systemic diseases such as sarcoidosis or Sjogrën's syndrome. Drug-induced gustatory disorders are also reported.