Recovery of hydrothermal vent communities in response to an induced disturbance at the Lucky Strike vent field (Mid-Atlantic Ridge).

So far, the natural recovery of vent communities at large scales has only been evaluated at fast spreading centers, by monitoring faunal recolonisation after volcanic eruptions. However, at slow spreading ridges, opportunities to observe natural disturbances are rare, the overall hydrothermal system being more stable. In this study, we implemented a novel experimental approach by inducing a small-scale disturbance to assess the recovery potential of vent communities along the slow-spreading northern Mid-Atlantic Ridge (nMAR). We followed the recovery patterns of thirteen Bathymodiolus azoricus mussel assemblages colonising an active vent edifice at the Lucky Strike vent field, in relation to environmental conditions and assessed the role of biotic interactions in recolonisation dynamics. Within 2 years after the disturbance, almost all taxonomic richness had recovered, with the exception of a few low occurrence species. However, we observed only a partial recovery of faunal densities and a major change in faunal composition characterised by an increase in abundance of gastropod species, which are hypothesised to be the pioneer colonists of these habitats. Although not significant, our results suggest a potential role of mobile predators in early-colonisation stages. A model of post-disturbance succession for nMAR vent communities from habitat opening to climax assemblages is proposed, also highlighting numerous knowledge gaps. This type of experimental approach, combined with dispersal and connectivity analyses, will contribute to fully assess the resilience of active vent communities after a major disturbance, especially along slow spreading centers targeted for seafloor massive sulphide extraction.

A new matrikine-derived peptide up-regulates longevity genes for improving extracellular matrix architecture and connections of dermal cell with its matrix.

OBJECTIVE: Skin extracellular matrix (ECM) is a dense and well-organized structure produced by fibroblasts. This ECM transduces environmental mechano-signals to cell nucleus through the integrin-actin complex, thus triggering ECM protein syntheses. The aim of this study was to discover a novel peptide, structurally related to dermal matrikines, that promotes syntheses of ECM components. METHODS AND RESULTS: Screening tests with 120 peptides were carried out by using normal dermal human fibroblasts (HF). As a result, one candidate of interest was isolated, the N-Prolyl Palmitoyl Tripeptide-56 Acetate (PP56), which increases collagen and fibronectin productions at gene and/or protein levels. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a recent and innovative analytical technology, in addition to more traditional techniques, it was showed that two metabolic pathways were significantly modulated: one for collagen production and one for actin. Moreover, this peptide up-regulated the transcription of Forkhead Box O (FOXO) and sestrin messenger RNAs (mRNA), leading to production of proteins involved into longevity and more recently in collagen production. RESULTS: Results indicated that this peptide is a potential candidate to improve ECM density and organization in a new way.

OBJECTIF: La matrice extracellulaire cutanée (MEC) est une structure dense et bien organisée produite par les fibroblastes. Cette MEC transduit les mécano-signaux environnementaux vers le noyau de la cellule par le biais du complexe intégrine-actine, ce qui déclenche la synthèse de protéines par la MEC. Le but de cette étude était de découvrir un nouveau peptide, structurellement apparenté aux matrikines dermiques, qui favorise la synthèse des composants de la MEC. MÉTHODES ET RÉSULTATS: Des tests de criblage avec 120 peptides ont été réalisés en utilisant des fibroblastes humains dermaux normaux (HF). Un candidat d'intérêt a été isolé, l'acétate de N-Prolyl Palmitoyl-Tripeptide-56 (PP56), qui augmente les productions de collagène et de fibronectine aux niveaux du gène et / ou de la protéine. En utilisant une technologie analytique récente et innovante, la spectrométrie de masse par chromatographie liquide-tandem (LC-MS / MS) ainsi que des techniques plus traditionnelles, il a été démontré que deux voies métaboliques sont modulées de manière significative: une pour la production de collagène et une pour l'actine. En outre, ce peptide a régulé positivement la transcription des ARN messagers (ARNm), du facteur de transcription Forkhead Box (FOXO) et de la sestrine, conduisant à la production de protéines impliquées dans la longévité et plus récemment dans la production de collagène. RÉSULTATS: Les résultats ont indiqué que ce peptide est un candidat potentiel pour améliorer la densité et l'organisation de la MEC d'une manière nouvelle.

Effect of nanosecond pulsed electric field on Escherichia coli in water: inactivation and impact on protein changes.

AIMS: This article shows the effect of nanosecond pulsed electric field (nsPEF) on Escherichia coli, which could imply a durable change in protein expressions and then impacted the phenotype of surviving bacteria that might lead to increase pathogenicity. METHODS AND RESULTS: The effects of nsPEF on E. coli viability and membrane permeabilization were investigated. One log10 reduction in bacterial counts was achieved at field strength of 10(7) V m(-1) with a train of 500 successive pulses of 60 × 10(-9) s. Incubation of germs after treatment with propidium iodide showed that membrane permeabilization was reversible. Possible protein changes of surviving bacteria were checked to assess potential phenotypical changes using two-dimensional electrophoresis. In our study, after 40 generations, only UniProt #P39187 was up-regulated with P ≤ 0·05 compared with the control and corresponded to the uncharacterized protein YtfJ. Antibiograms were used to check whether or not the pattern of cultivable bacteria after nsPEF deliveries changed. CONCLUSIONS: The results tend to show that nsPEFs are able to inactivate bacteria and have probably no serious impact in E. coli protein patterns. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of nsPEF is a safe promising new nonthermal method for bacterial inactivation in the food processing and environmental industry.

[Superior mesenteric artery syndrome following correction of spinal deformity: case report and review of the literature]. / Syndrome de la pince aorto-mésentérique après correction d'une déformation rachidienne.

Superior mesenteric artery syndrome is a rare complication which can develop after surgical correction of a spinal deformity. The syndrome is caused by an extrinsic compression on the third portion of the duodenum by the aorta posteriorly and the mesenteric artery anteriorly. We report here a case of aortomesenteric compression of the duodenum secondary to surgical correction of lower thoracic scoliosis in a 19-year-old female. The patient presented vomiting and intestinal obstruction ten days after spinal surgery. Treatment consisted in exclusive parenteral nutrition followed by careful surveillance and progressive reintroduction of oral food intake to avoid unnecessary surgery. Young thin subjects are predominantly exposed to this type of complication. The body mass index is a good indication to identify subjects at risk. Symptoms of upper gastrointestinal obstruction develop seven to ten days after surgery. Diagnosis is based on transit studies using a hydroluble contrast agent which reveals major gastric dilation and a clear interruption of the transit at the level of the third duodenum as well as retrograde peristaltism. Medical treatment should be undertaken first and is effective in the large majority of cases. Surgery may be proposed only in the event of failure. Recurrence is exceptional. Early diagnosis, delivery of clear information for the patient and family and multidisciplinary management are important points to consider for proper care for this complication which if neglected can become life-threatening.

The strong induction of metallothionein gene following cadmium exposure transiently affects the expression of many genes in Eisenia fetida: a trade-off mechanism?

Metal pollution causes disturbances at various levels of biological organization in most species. Important physiological functions could be affected in the exposed individuals and among the main physiological functions, immunity may provide one (or more) effector(s) whose expression can be directly affected by a metal exposure in various macroinvertebrates. Protein expressions were studied in order to test them as molecular biomarkers of metal exposure in Eisenia fetida. Selected effectors were calmodulin, heat shock proteins, superoxide dismutase, catalase, metallothionein, beta-adrenergic receptor kinase, pyruvate carboxylase, transcriptionally controlled tumor protein, protein kinase C, ubiquitin and cyclophilin-A. The level of expression of each gene was analysed in whole organism following exposures to cadmium in soil using real-time PCR. Metallothionein, transcriptionally controlled tumor protein and cyclophilin-A expression were also measured following copper exposures in soil because these genes seemed to be sensitive to copper. This work enabled to distinguish metallothionein and cyclophilin-A among the 15 selected effectors. A strong decrease of the number of transcripts was also detected for most effectors soon after the exposure to cadmium suggesting that a trade-off mechanism occurs.

Tricuspid bioprosthesis replacement with cryopreserved mitral homograft.

We report the case of replacement of a dysfunctional tricuspid Hancock bioprosthesis by a cryopreserved mitral homograft. Tricuspid bioprosthesis was approached on a beating heart. The mitral homograft was orientated so as the anatomic anterior leaflets corresponding and a semi rigid prosthetic ring was inserted. At 1 year follow-up, the patient's clinical condition and echocardiographic results were satisfactory.

Intracavity LiNbO(3) Fabry-Perot etalon for frequency stabilization and tuning of a single-mode quasi-continuous-wave titanium:sapphire ring laser.

We describe an intracavity LiNbO(3) Fabry-Perot etalon for frequency stabilization and tuning of a single-mode quasi-continuous-wave Ti:Al(2)O (3) ring laser. Taking into account the 150-micros pulse duration and the 40-Hz repetition rate of our laser, we achieve stabilization by 266-kHz modulation of 100-V peak-to-peak voltage applied to the electro-optic crystal. Tuning is ensured by the presence of a gain loop that contains a lock-in amplifier reacting with a multimorphous ceramic by means of 0-300-V dc voltage, which causes slight rotation of the LiNbO(3) Fabry-Perot etalon. A continuous frequency scan of 6 GHz was made that potentially can be extended to 6 cm(-1) .

Isolation of a member of ets gene family in the polychaete annelid Perinereis cultrifera.

Numerous genes belonging to the ets gene family have been described for a few years. The founder of this family is the v-ets proto-oncogene, which is the viral counterpart of the chicken c-ets-1 proto-oncogene. Main research was carried out both on Vertebrates, Drosophila and the nematod Caenorhabditis elegans. Previously, two genes of this family named Nd ets and Nd erg, were isolated in the polychaete annelid Hediste (Nereis) diversicolor. Here we have described the isolation of one gene from the ets family in another polychaete annelid named Perinereis cultrifera. By polymerase chain reaction using degenerated primers, we have amplified an approximatively 515 pb genomic region encoding the ETS domain and another domain designed as "R" domain by Qi et al. (1992) and which can mediate transactivation. By using this method for isolating members of the ets gene family, we are going to realize a phylogenetic study of the phylum of polychaete annelids.

Collaborative learning partnership creates the perinatal nurse practitioner.

A Jesuit university and a large medical center in the Rocky Mountain region combined talents and resources in response to a community need to develop a new practitioner program. Together, the university and the medical center created what neither one alone could have: the perinatal nurse practitioner (PNNP) program. At the time it was developed it was the first of its kind in the country. The collaborative relationship, the PNNP role, and the curriculum are described.