Consequences of genetic erosion on fitness and phenotypic plasticity in European tree frog populations (Hyla arborea)

The detrimental effects of genetic erosion on small isolated populations are widely recognized contrary to their interactions with environmental changes. The ability of genotypes to plastically respond to variability is probably essential for the persistence of these populations. Genetic erosion impact may be exacerbated if inbreeding affects plastic responses or if their maintenance were at higher phenotypic costs. To understand the interplay 'genetic erosion-fitness-phenotypic plasticity', we experimentally compared, in different environments, the larval performances and plastic responses to predation of European tree frogs (Hyla arborea) from isolated and connected populations. Tadpoles from isolated populations were less performant, but the traits affected were environmental dependant. Heterosis observed in crosses between isolated populations allowed attributing their low fitness to inbreeding. Phenotypic plasticity can be maintained in the face of genetic erosion as inducible defences in response to predator were identical in all populations. However, the higher survival and developmental costs for isolated populations in harsh conditions may lead to an additional fitness loss for isolated populations.

Assessment of risk of psoriatic arthritis in patients with plaque psoriasis: a systematic review of the literature

OBJECTIVE

The aim of this study was to determine the prevalence of psoriatic arthritis (PsA) in the patients with plaque psoriasis and to give recommendation for the diagnosis of PsA for dermatologists.

METHODS

A systematic search was performed in Pubmed, Cochrane and Embase databases. The key-words used from the Medical Searching Heading (MeSH) were: 'Psoriasis', 'Arthritis, Psoriatic', 'Uveitis' and 'Dactylitis'. We selected cross-sectional epidemiological studies written in English or French between January 1980 and October 2009.

RESULTS

The initial literature search identified 2171 references. Based on abstract reading and exclusion of studies not written in English or French, and without control group, the final selection included 20 epidemiological studies. With the eight studies using rheumatologically validated criteria, the prevalence of PsA among psoriasis patient spanned a wide range from 7% to 26%.

CONCLUSION

Psoriasis arthritis may affect up to 24% of psoriasis patients. Dermatologist should be aware of main clinical sign of PsA to promote earlier recognition and treatment of PsA.

Evidence-based recommendations to assess psoriasis severity: systematic literature review and expert opinion of a panel of dermatologists

BACKGROUND

Severity of psoriasis appears to be multidimensional and its assessment in everyday clinical practice requires a complex holistic approach.

OBJECTIVES

To develop evidence-based recommendations to assess severity of plaque-type psoriasis in adult patients in everyday clinical practice.

METHODS

A scientific committee (10 members identified on the basis of their expertise in psoriasis) using Delphi methodology selected eight questions in three domains: severity, health-related quality of life (HR-QoL) and comorbidities. Three systematic literature reviews (one per domain) of all studies published between January 1980 and June 2009 were performed based on Pub-Med, Cochrane and Embase database. Selected articles were systematically reviewed and evidence appraised according to the Oxford Levels of Evidence. On June 2009, a group of 44 French dermatologists both hospital and office based participated in a meeting including three separate rounds of discussions, plenary sessions, and modified Delphi technique votes. Recommendations for clinical practice based on systematic review and clinical experience were formulated by the group. Subsequently, agreements among the participants regarding these recommendations as well as potential impact on clinical practice were evaluated.

RESULTS

A total of 10 642 references were identified, of which 154 articles were analysed. Ten key recommendations on the assessment of psoriasis severity were formulated: three recommendations relating to severity assessment, three recommendations relating to HR-QoL (including the use of the Dermatology Life Quality Index [DLQI] in clinical practice) and four recommendations relating to comorbidities (including systematic screening for peripheral or axial inflammatory joint damage, regardless of psoriasis severity).

CONCLUSIONS

Ten recommendations to assess the severity of plaque-type psoriasis in adult patients in daily practice were developed. The recommendations are based on systematic appraisal of available evidence. They were developed and supported by a panel of dermatologists, which enhances their validity and practical relevance.

A laboratory X-ray microbeam for combined X-ray diffraction and fluorescence measurements

A prototype instrument has been developed which allows the simultaneous acquisition of both X-ray diffraction and X-ray fluorescence data at a microscopic length scale for mapping studies on materials. The instrument takes full advantage of the performance of recently developed optics and detectors to optimize the detection of low-intensity signals with a monochromatic X-ray microbeam of 20 µm diameter with a laboratory X-ray source.

[Long-term follow-up of the efficacy of methotrexate alone or in combination with low doses of oral corticosteroids in the treatment of alopecia areata totalis or universalis]

BACKGROUND

Treatment of severe and chronic forms of alopecia areata (AA) totalis remains difficult. It has been suggested that methotrexate (MTX) is an efficacious treatment for AA totalis. The aim of our study was to assess the long-term safety and efficacy of MTX in patients with chronic severe forms of AA totalis.

PATIENTS AND METHODS

Thirty-three patients (24 women and nine men) with AA totalis or universalis were included. Mean disease duration was 7.7 years and these patients had not responded to prior standard treatment. The initial weekly dosage of MTX was 15 mg (n=2), 20mg (n=16) or 25mg (n=15). Nineteen patients (58%) were treated with MTX and low doses of corticosteroids (prednisone 10-20mg/d), while 14 patients (42%) received MTX alone. The primary end-point was complete hair regrowth under treatment.

RESULTS

Twenty-one patients had total hair regrowth and 13 patients were considered as treatment failures, with 10 of these having partial regrowth and three having no regrowth. Complete regrowth was seen in 12 of 19 patients (63%) on combined treatment and in eight of 14 patients (57%) on MTX alone. The onset of hair regrowth was noted after a median delay of 3 months. At the end of the study, after a median of 30 months' follow-up, the median cumulative dose of MTX was 1.8 g (400mg-5.5 g). Relapse was observed on corticosteroid dose reduction or withdrawal in 16 of the 20 patients in whom total hair regrowth initially occurred. Regrowth after treatment of relapse was seen in 14 of these 16 patients (87%). Seven patients experienced adverse events consisting of transient elevated transaminases (n=4), persistent nausea (n=2) and lymphocytopenia (n=1).

CONCLUSION

MTX alone or in combination with low doses of oral corticosteroids resulted in complete hair regrowth in about half of these patients presenting AA totalis or universalis. Lasting improvement required continuous treatment in most cases.

[Intra- and interfamilial phenotype variation in Birt-Hogg-Dubé syndrome: Consequences for therapy]

BACKGROUND

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal-dominantly inherited genodermatosis that predisposes to the development of benign hair follicle tumours, lung cysts, kidney tumours, and possibly colonic cancers, due to mutations in the FLCN gene. We report cases involving a new mutation in three unrelated families.

MATERIALS AND METHODS

Blood samples of three probands were submitted for a molecular diagnosis of BHDS. Following DNA extraction, FLCN gene sequencing was performed. The identified mutations were confirmed on a second sample. A cancer genetics consultation was organized and specific tests (dermatological examination, CT scan of chest and abdomen and colonoscopy) were proposed for each BHDS patient.

RESULTS

FLCN gene-sequencing analysis revealed an identical complex harmful mutation in all three families. The first proband showed fibrofolliculomas (FF), a history of pneumothorax and colonic adenoma. The mutation was found in a brother and two sisters, who were asymptomatic, and in a niece with FF. The second proband showed FF. The mutation was found in her mother, who had FF. The third proband presented diffuse emphysema and very rare FF.

DISCUSSION

This case report shows extremely wide intra- and interfamilial phenotype variation within individuals having a similar FLCN gene mutation. In large cohorts of BHDS patients, no genotype-phenotype correlation has been shown. This case emphasises the vital importance of presymptomatic diagnosis for each member of a BHDS family by means of a cancer genetics consultation, followed by a CT scan of the chest and abdomen, colonoscopy and annual kidney imaging.

Treatment of bullous pemphigoid and pemphigus. The French experience, 2009 update

There have been several recent advances in the management of auto-immune blistering diseases. The aim of this review was to provide an update, based on ''expert'' interpretation of published evidences on the treatments of pemphigoid and pemphigus. A literature search (Pubmed) of all randomized controlled trials that had not been included in two reviews published by the Cochrane Skin Group in 2005 on pemphigoid and 2009 on pemphigus have been performed. Recent series of pemphigus cases treated with anti-CD20 antibodies have also been reviewed. Concerning pemphigoid there is good evidence that high dose topical clobetasol propionate should be the first line treatment, and that further studies should focus on the finding of simple and well tolerated maintenance therapy. For pemphigus, after decades of inconclusive trials, there is now some evidence of a moderate efficacy of azathioprine, cyclophosphamide, mycophenolate in addition to corticosteroids and may be of intravenous immunoglobulins. The practical impact of such evidence is strongly challenged by the possible superiority of anti-CD20 monoclonal antibodies that may emerge as the most efficient treatment of pemphigus. Because of concerns on long-term safety, multicenter trials of these ''biological'' treatments should be undertaken urgently.