Distinctive serum miRNA profile in mouse models of striated muscular pathologies

Biomarkers are critically important for disease diagnosis and monitoring. In particular, close monitoring of disease evolution is eminently required for the evaluation of therapeutic treatments. Classical monitoring methods in muscular dystrophies are largely based on histological and molecular analyses of muscle biopsies. Such biopsies are invasive and therefore difficult to obtain. The serum protein creatine kinase is a useful biomarker, which is however not specific for a given pathology and correlates poorly with the severity or course of the muscular pathology. The aim of the present study was the systematic evaluation of serum microRNAs (miRNAs) as biomarkers in striated muscle pathologies. Mouse models for five striated muscle pathologies were investigated: Duchenne muscular dystrophy (DMD), limb-girdle muscular dystrophy type 2D (LGMD2D), limb-girdle muscular dystrophy type 2C (LGMD2C), Emery-Dreifuss muscular dystrophy (EDMD) and hypertrophic cardiomyopathy (HCM). Two-step RT-qPCR methodology was elaborated, using two different RT-qPCR miRNA quantification technologies. We identified miRNA modulation in the serum of all the five mouse models. The most highly dysregulated serum miRNAs were found to be commonly upregulated in DMD, LGMD2D and LGMD2C mouse models, which all exhibit massive destruction of striated muscle tissues. Some of these miRNAs were down rather than upregulated in the EDMD mice, a model without massive myofiber destruction. The dysregulated miRNAs identified in the HCM model were different, with the exception of one dysregulated miRNA common to all pathologies. Importantly, a specific and distinctive circulating miRNA profile was identified for each studied pathological mouse model. The differential expression of a few dysregulated miRNAs in the DMD mice was further evaluated in DMD patients, providing new candidates of circulating miRNA biomarkers for DMD.

[Emergency admission to a palliative care unit]

Emergency admission to a palliative care unit. The emergency admission of a patient to a palliative care unit requires availability, trust in the professionals who request the admission and the conviction that this care is essential for the patient's overall care. An example with the palliative care unit of Montfermeil hospital.

Lack of correlation between outcomes of membrane repair assay and correction of dystrophic changes in experimental therapeutic strategy in dysferlinopathy

Mutations in the dysferlin gene are the cause of Limb-girdle Muscular Dystrophy type 2B and Miyoshi Myopathy. The dysferlin protein has been implicated in sarcolemmal resealing, leading to the idea that the pathophysiology of dysferlin deficiencies is due to a deficit in membrane repair. Here, we show using two different approaches that fullfiling membrane repair as asseyed by laser wounding assay is not sufficient for alleviating the dysferlin deficient pathology. First, we generated a transgenic mouse overexpressing myoferlin to test the hypothesis that myoferlin, which is homologous to dysferlin, can compensate for the absence of dysferlin. The myoferlin overexpressors show no skeletal muscle abnormalities, and crossing them with a dysferlin-deficient model rescues the membrane fusion defect present in dysferlin-deficient mice in vitro. However, myoferlin overexpression does not correct muscle histology in vivo. Second, we report that AAV-mediated transfer of a minidysferlin, previously shown to correct the membrane repair deficit in vitro, also fails to improve muscle histology. Furthermore, neither myoferlin nor the minidysferlin prevented myofiber degeneration following eccentric exercise. Our data suggest that the pathogenicity of dysferlin deficiency is not solely related to impairment in sarcolemmal repair and highlight the care needed in selecting assays to assess potential therapies for dysferlinopathies.

[Assessment of scientific production after initial medical education at the Faculty of Medicine of Angers from 2002 to 2008]

INTRODUCTION

The activity of scientific publication after initial medical education is unclear. The purpose of this study was to evaluate the proportion of MD theses and Board certification manuscripts resulting in a publication, their impact in terms of SIGAPS points and the main difficulties in the publication of this work.

METHODS

MD theses sustained from 2002 to 2008 at the Faculty of Medicine of Angers have been identified from the "Système universitaire de documentation" (SUDOC), catalog, and specialty certification manuscripts (Board and Complementary Board) directly to diplomates. Publications were searched in Medline via Pubmed, ISI Web of Knowledge and in the three SIGAPS reports from 2002 to 2008. A survey aimed at determining the barriers to publication and the way to suppress them was launched to all MD directors and specialty mentors.

RESULTS

Five hundred and ninety-eight theses were sustained, 311 (52%) in general medicine and 287 (48%) in specialties. One hundred and sixty-five theses have resulted in publication (28%) of which 97 (16%) indexed in Medline via Pubmed (11% in general medicine and 22% in specialty). Thirty-three of these 97 articles (35%) were published in journals of high quality classes A, B or C of SIGAPS classification. These articles from theses represented 4.17% of the SIGAPS scoring of the hospital calculated on a total of 2088 articles over this period. Two hundred and four specialty certification manuscripts resulted in 69 articles (33.8%), 50 (24.5%) indexed in Medline. The rate of publication of these specialty manuscripts, Board and Complementary Board, were respectively 31% (45/145) and 40.7% (24/59). They represented 1.9% (432 points) total SIGAPS score. The main barriers to publication were lack of time of directors, remote students after the promotion and the lack of logistic resources.

CONCLUSION

Scientific publications issued from initial medical education at the Faculty of Medicine of Angers was of good quality but quantitatively insufficient, and contributed poorly to the University Hospital funding despite a significant number of diplomates. Logistical support should be considered in order to promote scientific production after initial medical education.

Dependent patients discharged home from PRM departments: relevant indicators

OBJECTIVE

To evaluate simple, measurable indicators of optimal organizational procedures for the hospital-to-home discharge of dependent patients.

MATERIAL AND METHOD

All the general practitioners (GPs) in the Maine-et-Loire county of France were sent a questionnaire asking them to rank the three main criteria (from the most important to the least significant) from a list of 14. We analyzed the median ranking for each item and identified the most important items in terms of their relative frequency.

RESULTS

The response rate was 10.77% (104 out of 966). Four criteria had a median score over 9: contact with the GP prior to discharge, informing the GP of the discharge date, training for the patient and his/her family in activities of daily living and providing a list of people to be contacted in the event of a problem at home. Respite hospitalization (in the event of difficulties at home) was cited as one of the three most relevant criteria.

DISCUSSION-CONCLUSION

The criteria highlighted by the GPs were not highly specific for the discharge of a dependent patient. However, it would be interesting to extend this study by interviewing other stakeholders and determining whether these criteria indeed improve the organization of hospital-to-home discharge.

Psychosocial risk factors for chronic low back pain in primary care--a systematic review

BACKGROUND

Low back pain (LBP) is a major public health problem, often encountered in primary care. Guidelines recommend early identification of psychosocial factors that could prevent recovery from acute LBP.

METHODS

To review the evidence on the prognostic value of psychosocial factors on transition from acute to chronic non-specific LBP in the adult general population. Systematic review is the design of the study. A systematic search was undertaken for prospective studies dealing with psychosocial risk factors for poor outcome of LBP in primary care, screening PubMed, PsychInfo and Cochrane Library databases. The methodological quality of studies was assessed independently by two reviewers using standardized criteria before analysing their main results.

RESULTS

Twenty-three papers fulfilled the inclusion criteria, covering 18 different cohorts. Sixteen psychosocial factors were analysed in three domains: social and socio-occupational, psychological and cognitive and behavioural. Depression, psychological distress, passive coping strategies and fear-avoidance beliefs were sometimes found to be independently linked with poor outcome, whereas most social and socio-occupational factors were not. The predictive ability of a patient's self-perceived general health at baseline was difficult to interpret because of biomedical confounding factors. The initial patient's or care provider's perceived risk of persistence of LBP was the factor that was most consistently linked with actual outcome.

CONCLUSION

Few independent psychosocial risk factors have been demonstrated to exist. Randomized clinical trials aimed at modifying these factors have shown little impact on patient prognosis. Qualitative research might be valuable to explore further the field of LBP and to define new management strategies.

A naturally occurring human minidysferlin protein repairs sarcolemmal lesions in a mouse model of dysferlinopathy

Dysferlinopathies are autosomal recessive, progressive muscle dystrophies caused by mutations in DYSF, leading to a loss or a severe reduction of dysferlin, a key protein in sarcolemmal repair. Currently, no etiological treatment is available for patients affected with dysferlinopathy. As for other muscular dystrophies, gene therapy approaches based on recombinant adeno-associated virus (rAAV) vectors are promising options. However, because dysferlin messenger RNA is far above the natural packaging size of rAAV, full-length dysferlin gene transfer would be problematic. In a patient presenting with a late-onset moderate dysferlinopathy, we identified a large homozygous deletion, leading to the production of a natural "minidysferlin" protein. Using rAAV-mediated gene transfer into muscle, we demonstrated targeting of the minidysferlin to the muscle membrane and efficient repair of sarcolemmal lesions in a mouse model of dysferlinopathy. Thus, as previously demonstrated in the case of dystrophin, a deletion mutant of the dysferlin gene is also functional, suggesting that dysferlin's structure is modular. This minidysferlin protein could be used as part of a therapeutic strategy for patients affected with dysferlinopathies.

Methods for noninvasive monitoring of muscle fiber survival with an AAV vector encoding the mSEAP reporter gene

Muscular dystrophies (MD) are a group of genetically and phenotypically heterogeneous inherited disorders characterized by the progressive degeneration of the skeletal muscle tissue. In the last decade, a tremendous amount of studies were performed to test therapeutic strategies in animal models. Evaluation of such strategies requires the use of criteria predictive of their therapeutic relevance. Here we describe a simple, noninvasive assay to monitor muscle degenerative process. An adeno-associated vector encoding a secreted form of murine embryonic alkaline phosphatase (mSEAP) reporter gene is administrated at the time of treatment. The amount of circulating mSEAP will reflect the level of myofiber survival. We tested this assay with therapeutic gene transfer. We found a strong correlation between therapeutic gene expression/muscle disease amelioration and the circulating levels of mSEAP. The assay will be very useful for monitoring muscle cell survival after therapeutic intervention.