Identification and Characterization of a cDNA and the Structural Gene Encoding the Mouse Epithelial Membrane Protein-1

The PMP22/EMP/MP20 gene family includes four closely related proteins, peripheral myelin protein-22 (PMP22), epithelial membrane protein-1 (EMP-1), epithelial membrane protein-2 (EMP-2), and epithelial membrane protein-3 (EMP-3), which share amino acid identities ranging from 33 to 43%. In addition, the lens-specific membrane protein MP20 represents a more distant relative. Functionally, this family of proteins is likely to play important roles in the control of cell proliferation, cell differentiation, and cell death. In particular, mutations affecting thePMP22gene are responsible for various hereditary peripheral neuropathies in humans and mice. We report the isolation and characterization of a mouse EMP-1 cDNA and the correspondingemp-1gene. Mouse EMP-1 displays 93% amino acid identity to rat EMP-1 and 39% identity to mouse PMP22. The cDNA-predicted EMP-1 protein contains four putative membrane-associated domains and can beN-linked glycosylatedin vitro.EMP-1 is encoded by a single-copy gene with the positions of introns exactly conserved betweenemp-1andPMP22,corroborating the hypothesis that both genes belong to the same family. Computer-predicted structural domains of EMP-1 are partially mirrored by the exon/intron structure ofemp-1.Most interestingly, exon 4, which covers the potential second transmembrane domain, a small intracellular loop, and half of the third transmembrane domain, encodes the most highly conserved regions between the EMP-1 and PMP22 proteins and is also remarkably conserved in the MP20 gene, indicating some shared functional significance for this module in the PMP22/EMP/MP20 family.     

Two new Cocconeis taxa (Bacillariophyceae) from coral sands off the Mascarenes (Western Indian Ocean) and some related unidentified taxa

Coral sands off Réunion Island and Rodrigues (Mascarene archipelago, Western Indian Ocean) support diverse diatom communities, particularly rich in Monoraphidineae. Recent surveys of reef environments (June 2005 and June 2007) permitted the recognition of several taxa belonging to the diatom genus Cocconeis, among which are two new, relatively small taxa, epipsammic on coral sand. Cocconeis coronata Riaux-Gobin et Romero sp. nov. is similar to C. scutellum but has its own distinctive features. In external view, the concave raphe valve possesses uniseriate striae and a subsident hyaline marginal rim, while the strongly convex sternum valve has a submarginal, generally continuous crest, a hexagonal pattern of areolation, short, rounded spines that are often regularly arranged around valve face areolae, a complex areola hymen and small marginal chambers. Some morphometric differences were noted between the populations of C. coronata at Réunion and Rodrigues. Cocconeis margaritata Riaux-Gobin et Al-Handal, sp. nov. is smaller, possesses a sternum valve like that of C. placentula and C. neothumensis, but has denser striation and small pearl-like concretions around the areola aperture on the sternum valve. Several other taxa that resemble, or may be varieties of, C. margaritata require further study before being formally described. Cocconeis margaritata and C. coronata are small and relatively rare, so their study requires scanning electron microscopy.     

Early history of mammals is elucidated with the ENCODE multiple species sequencing data

Understanding the early evolution of placental mammals is one of the most challenging issues in mammalian phylogeny. Here, we addressed this question by using the sequence data of the ENCODE consortium, which include 1% of mammalian genomes in 18 species belonging to all main mammalian lineages. Phylogenetic reconstructions based on an unprecedented amount of coding sequences taken from 218 genes resulted in a highly supported tree placing the root of Placentalia between Afrotheria and Exafroplacentalia (Afrotheria hypothesis). This topology was validated by the phylogenetic analysis of a new class of genomic phylogenetic markers, the conserved noncoding sequences. Applying the tests of alternative topologies on the coding sequence dataset resulted in the rejection of the Atlantogenata hypothesis (Xenarthra grouping with Afrotheria), while this test rejected the second alternative scenario, the Epitheria hypothesis (Xenarthra at the base), when using the noncoding sequence dataset. Thus, the two datasets support the Afrotheria hypothesis; however, none can reject both of the remaining topological alternatives.     

Characterization of serracin P,a phage-tail-like bacteriocin,and its activity against Erwinia amylovora,the fire blight pathogen

Serratia plymithicum J7 culture supernatant displayed activity against many pathogenic strains of Erwinia amylovora, the causal agent of the most serious bacterial disease of apple and pear trees, fire blight, and against Klebsiella pneumoniae, Serratia liquefaciens, Serratia marcescens, and Pseudomonas fluorescens. This activity increased significantly upon induction with mitomycin C. A phage-tail-like bacteriocin, named serracin P, was purified from an induced culture supernatant of S. plymithicum J7. It was found to be the only compound involved in the antibacterial activity against sensitive strains. The N-terminal amino acid sequence analysis of the two major subunits (23 and 43 kDa) of serracin P revealed high homology with the Fels-2 prophage of Salmonella enterica, the coliphages P2 and 168, the phiCTX prophage of Pseudomonas aeruginosa, and a prophage of Yersinia pestis. This strongly suggests a common ancestry for serracin P and these bacteriophages.     

Time-of-flight secondary ion mass spectrometry: characterisation of stainless steel surfaces immersed in natural seawater.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been employed to study the biofouling of stainless steel samples immersed in seawater. The aim of these characterisations was to understand the initial mechanisms of biomolecule adsorption for relatively short immersion times (from 0 to 24 h).The results show that: (i) there were unavoidable sample "precontaminations" on the surfaces, despite precaution during their preparation and manipulation (washing, drying and storing); (ii) the major peaks detected were the substrate ones whatever the immersion time [However, some organic (nitrogen and oxygen containing) and inorganic secondary ions appeared and grew with the immersion time.]; (iii) the surface contaminations, the nonuniformity of the adsorbed material so as and bacteria have been clearly observed by high-lateral resolution molecular ToF-SIMS mapping.     

Fine structural survey of old cuticle degradation during pre-ecdysis in two European Atlantic crabs

Light and transmission electron microscopy were used to monitor changes due to the degradation of the old exoskeleton and related events in the sclerites, articular membranes, and gills of two decapod crustaceans (Carcinus maenas and Macropipus puber) during pre-ecdysis. In both sclerites and articular membranes, degradation follows a similar general pattern in both crab species, while the gill cuticle appears unaltered. In early pre-ecdysis (D(0)), the degradation of the old cuticle starts with the secretion of ecdysial droplets by the epidermis. Apolysis, occurring at stage D(1)', is re-defined as an event, not necessarily morphologically observable, consisting in the loss of adherence between the epidermis and the old cuticle during early pre-ecdysis of arthropods. At the stage D(1)', the moulding of the epidermal cell surface occurs in preparation to the deposition of the new cuticle and causes the opening of the ecdysial cleft. In the principal layer of sclerites, degradation of the chitin-protein microfibres should precede mineral dissolution. In contrast to the other degraded cuticle layers, the membranous layer of sclerites and the innermost endocuticular lamellae of articular membranes are transformed into a digestion-resistant fibrous network resembling the ecdysial membrane of insects.     

Ultrastructure and cytochemistry of the early calcification site and of its mineralization organic matrix in Paracentrotus lividus (Echinodermata: Echinoidea)

 The ultrastructure and cytochemistry of skeleton formation sites prior to mineralization are described for the first time in echinoderms. These early sites are intracellular vacuoles located in syncytial pseudopodia of skeleteton-forming cells. They contain a mineralization organic matrix, which shows a calcium-binding ability and is framed in a tridimensional structure made of concentric layers bridged by radial threads. This organic matrix presents repetitive structures which could be implicated in mineralization control. Both the tridimensional organization of the organic matrix and its framing, before mineralization starts, question the current theories which suggest that the echinoderm organic matrix is soluble at the onset of mineralization and adsorbs on the forming crystal. Accepted: 19 March 1998     

High Sodium and Low Potassium Intake among Italian Children: Relationship with Age,Body Mass and Blood Pressure

Background

Hypertension is the leading cause of death in developed countries and reduction of salt intake is recommended as a key preventive measure.

Objective

To assess the dietary sodium and potassium intakes in a national sample of Italian children and adolescents and to examine their relationships with BMI and blood pressure (BP) in the framework of the MINISAL survey, a program supported by the Italian Ministry of Health.

Population and Methods

The study population included 1424 healthy subjects (766 boys, 658 girls) aged 6-18 years (mean age: 10.1±2.9) who were consecutively recruited in participating National Health Service centers in 10 Italian regions. Electrolyte intake was estimated from 24 hour urine collections tested for completeness by the concomitant measurement of creatinine content. Anthropometric indices and BP were measured with standardized procedures.

Results

The average estimated sodium intake was 129 mmol (7.4 g of salt) per day among boys and 117 mmol (6.7 g of salt) among girls. Ninety-three percent of the boys and 89% of the girls had a consumption higher than the recommended age-specific standard dietary target. The estimated average daily potassium intakes were 39 mmol (1.53 g) and 36 mmol (1.40 g), respectively, over 96% of the boys and 98% of the girls having a potassium intake lower than the recommended adequate intake. The mean sodium/potassium ratio was similar among boys and girls (3.5 and 3.4, respectively) and over 3-fold greater than the desirable level. Sodium intake was directly related to age, body mass and BP in the whole population.

Conclusions

The Italian pediatric population is characterized by excessive sodium and deficient potassium intake. These data suggest that future campaigns should focus on children and adolescents as a major target in the framework of a population strategy of cardiovascular prevention.     

HIV Shedding from Male Circumcision Wounds in HIV-Infected Men: A Prospective Cohort Study

BackgroundA randomized trial of voluntary medical male circumcision (MC) of HIV—infected men reported increased HIV transmission to female partners among men who resumed sexual intercourse prior to wound healing. We conducted a prospective observational study to assess penile HIV shedding after MC.ConclusionPenile HIV shedding is significantly reduced after healing of MC wounds. Lower plasma VL is associated with decreased frequency and quantity of HIV shedding from MC wounds. Starting ART prior to MC should be considered to reduce male-to-female HIV transmission risk. Research is needed to assess the time on ART required to decrease shedding, and the acceptability and feasibility of initiating ART at the time of MC.     

The anti-biofilm activity secreted by a marine Pseudoalteromonas strain

Bacterial biofilms occur on all submerged structures in marine environments. The authors previously reported that the marine bacterium Pseudoalteromonas sp. 3J6 secretes antibiofilm activity. Here, it was discovered that another Pseudoalteromonas sp. strain, D41, inhibited the development of strain 3J6 in mixed biofilms. Confocal laser scanning microscope observations revealed that the culture supernatant of strain D41 impaired biofilm formation of strain 3J6 and another marine bacterium. A microtiter plate assay of the antibiofilm activity was set up and validated with culture supernatants of Pseudoalteromonas sp. 3J6. This assay was used to determine the spectra of action of strains D41 and 3J6. Each culture supernatant impaired the biofilm development of 13 marine bacteria out of 18. However, differences in the spectra of action and the physical behaviours of the antibiofilm molecules suggest that the latter are not identical. They nevertheless share the originality of being devoid of antibacterial activity against planktonic bacteria.