Broad spectrum repairing properties of an extract of Aquaphilus dolomiae on in vitro and ex vivo models of injured skin.

BACKGROUND: A biological concentrate was produced from cultures of an Avène aquatic microflora isolate, namely Aquaphilus dolomiae. Some of the beneficial effects on diseased and damaged skin are thought to be due to the presence of this microorganism. AIMS: An extract of A. dolomiae (A. dolomiae extract-G2, ADE-G2) was evaluated for its wound-healing effects using in vitro and ex vivo models of injured skin. METHODS: The effect of ADE-G2 on the proliferation of fibroblasts, migration of keratinocytes and re-epithelialization of ex vivo wounded skin explants was measured. Antimicrobial protection by ADE-G2 was measured by analysing the gene expression of a panel of antimicrobial proteins (AMPs) in keratinocytes (RNASE7, S100A7, DEFB4A/B and DEFb103B), as well as the protein encoded by DEFB4A-B (hBD2) in the medium. RESULTS: ADE-G2 increased fibroblast proliferation and keratinocyte migration, as well as re-epithelialization of wounded ex vivo skin. ADE-G2 induced the expression of all AMP genes analysed in keratinocytes, as well as stimulated the release in to the medium of hBD2 peptide, encoded by DEFB4A/B. CONCLUSIONS: We have shown the broad spectrum of the repairing properties of the A. dolomiae extract, ADE-G2. These results support the use of ADE-G2 as a promising component for use in formulations aimed at repairing skin, limiting wound superinfection and preventing complicated wounds.

Protective effect of Aquaphilus dolomiae extract-G1, ADE-G1, on tight junction barrier function in a Staphylococcus aureus-infected atopic dermatitis model.

BACKGROUND: Atopic dermatitis (AD) is a common skin disease characterized by recurrent pruritic inflammatory skin lesions and defects of the skin barrier. Bacterial infection with Staphylococcus aureus contributes to increased severity of AD by compromising the barrier further. A microorganism component of Avène Thermal Spring Water, Aquaphilus dolomiae, is thought to contribute to some of its beneficial effects to skin, eg AD alleviation. AIMS: Here, we have investigated the effects of an extract of A. dolomiae, A. dolomiae extract-G1 (ADE-G1), on the structural barrier function of keratinocytes, tight junction (TJ) protein expression and the expression of several genes altered in AD patients. METHODS: An epidermal cell culture model mimicking the AD environment and phenotype was used, in which S. aureus-infected cell cultures of normal human epidermal keratinocytes were exposed to a proinflammatory environment. Endpoints measured included the transepithelial electrical resistance (TER) and immunohistological staining of the epidermal TJ proteins, claudin and occludin. Additional analysis was made of several genes known to be differentially regulated in skin from AD patients (C-C motif chemokine ligand 20 (CCL20), interleukin-8 (IL-8), S100 calcium binding protein A7 (S100A7), defensin beta 4 (DEFB4) and filaggrin). RESULTS: Aquaphilus dolomiae extract-G1 strongly increased TER in non-infected cells and provided protection against infection by overcoming the decrease in TER induced by the infection with S. aureus. In infected cells exposed to a pro-inflammatory environment - depicting AD-like conditions - TER protection by ADE-G1 was still observed. Gene expression analysis of infected and pro-inflammatory stimulated cells indicated that ADE-G1 modulated the inflammatory response (induced IL-8 and attenuated CCL20 expression), increased antimicrobial activities (induced DEFB4 and A100A7) and strengthened barrier function (restored filaggrin expression). CONCLUSIONS: ADE-G1 reinforces barrier function and strongly protects TJ barrier disruption induced by bacterial infection and inflammation.

In vitro approaches to pharmacological screening in the field of atopic dermatitis.

In vitro models are valuable for evaluating potential active ingredients and other molecules used in medications for atopic dermatitis (AD). However, finding appropriate in vitro models can be problematic. Our strategy was to set up different in vitro models that would mimic the pathomechanisms of AD. We describe five such models - the AD keratinocyte model, the AD reconstructed human epidermis model, the adaptive immunity model, the innate immunity model and the pruritus model - which we have used to evaluate a new ingredient for emollients derived from a biological extract. The models chosen provide useful data for the pharmacological characterization of active ingredients in adjunctive treatments for AD.

Phase stability of Fe-5at%Cr and Fe-10at%Cr films under Fe+ ion irradiation.

This work is within the objective of understanding the effects caused to Fe-Cr alloys by fast Fe ion irradiation. As the penetration length of Fe ion is of the order of hundreds of nanometers, 70 nm Fe-5at%C and Fe-10at%Cr films were irradiated at room temperature with 490 keV Fe+ ions at increasing fluence corresponding to a maximum damage of 50 displacements per atom (dpa). In Fe-5at%Cr alloy the Cr solute concentration remains unaltered even after a damage of 50 dpa. In the 10at%Cr the Cr solute concentration is reduced, with the increase of damage, asymptotically to a value of 7.2 at%.

[Multiple primary intraductal tumors of Wirsung's duct: demonstration of a relation between benign and malignant tumors]. / Tumeurs intra-canalaires primitives multiples du canal de Wirsung: démonstration d'une filiation entre tumeurs bénignes et malignes.

A case of multiple villous and, more rarely, tubulovillous adenomas of the main pancreatic duct, associated with a diffuse infiltrating adenocarcinoma of the pancreas in which evidence for a link between these lesions is supported by histopathologic features, is reported in a 53 year old patient. Clinical presentation included abdominal pain, weight loss and chronic diarrhea with steatorrhea related to pancreatic insufficiency. Retrograde endoscopic pancreatography showed a complete stenosis of the main pancreatic duct located 3 mm beyond the ampulla of Vater. CT scan showed an heterogeneous cephalic pancreatic tumor with extensive enlargement of the main pancreatic duct. After total pancreatectomy, recovery was maintained (follow-up 18 months). By analogy to colorectal tumors, a new pathologic classification of these rare neoplasms may be proposed.

[Chronic active hepatitis associated with anti-native DNA antibodies: incidence of drug etiology]. / Hépatites chroniques actives associées à des anticorps anti-ADN natif: fréquence de l'étiologie médicamenteuse.

Of 75 patients with HBsAg negative chronic active hepatitis (CAH), 28 had antinuclear antibodies in their serum. We have tested these patients' sera for serum antibodies against double stranded (native) DNA (anti-ds-DNA), by immunofluorescence with Crithidia luciliae as substrate. They were found in 14 patients (50 p. 100). Thirteen of the patients with anti-ds-DNA and 11 of those without were female; the mean ages were 64 +/- 16 and 56 +/- 19 years, respectively. The clinical and biological signs seemed to be more severe in patients with anti-ds-DNA than in those without. Liver histological activity and frequency of cirrhosis (about 50 p. 100) were similar in patients with or without anti-ds-DNA. Ten of the 14 patients with anti-ds-DNA had been given hepatotoxic drugs whereas only 2 patients lacking these antibodies had taken a hepatotoxic drug (p less than 0.01). In subjects with anti-ds-DNA, clometacin was the most common hepatotoxic drug, taken alone in 5 patients or together with other hepatotoxic drugs in 3 subjects. Only 4 of the patients with anti-ds-DNA displayed symptoms of systemic lupus erythematosus and two of these subjects took a hepatotoxic drug. In our experience, serum anti-ds-DNA were frequently found in patients with CAH and antinuclear antibodies; in this group CAH was often associated with hepatotoxic drugs, especially clometacin. Thus, the presence of anti-ds-DNA in sera of patients with HBsAg negative CAH may be an indication of drug-induced liver damage.

Structure-based secondary structure-independent approach to design protein ligands: Application to the design of Kv1.2 potassium channel blockers.

We have developed a structure-based approach to the design of protein ligands. This approach is based on the transfer of a functional binding motif of amino acids, often referred as to the "hot spot", on a host protein able to reproduce the functional topology of these residues. The scaffolds were identified by a systematic in silico search in the Protein Data Bank for proteins possessing a group of residues in a topology similar to that adopted by the functional motif in a reference ligand of known 3D structure. In contrast to previously reported studies, this search is independent of the particular secondary structure supporting the functional motif. To take into account the global properties of the host protein, two additional criteria were taken into account in the selection process: (1) Only those scaffolds sterically compatible with the positioning of the functional motif as observed in a reference complex model were retained. (2) Host proteins displaying electrostatic potentials, in the region of the transferred functional motif, similar to that of the reference ligand were selected. This approach was applied to the development of protein ligands of the Kv1.2 channel using BgK, a small protein isolated from the sea anemone Bunodosoma granulifera, as the reference ligand. Four proteins obtained by this approach were produced for experimental evaluation. The X-ray structure of one of these proteins was determined to check for similarity of the transferred functional motif with the structure it adopts in the reference ligand. Three of these protein ligands bind the Kv1.2 channel with inhibition constants of 0.5, 1.5, and 1.6 microM. Several mutants of these designed protein ligands gave binding results consistent with the presumed binding mode. These results show that protein ligands can be designed by transferring a binding motif on a protein host selected to reproduce the functional topology of this motif, irrespective to the secondary structure supporting the functional motif, if the host protein possesses steric and electrostatic properties compatible with the binding to the target. This result opens the way to the design of protein ligands by taking advantage of the considerable structural repertoire of the Protein Data Bank.

[Gram-negative septicemia and bacteremia in an internal medicine department]. / Septicémies ou bactériémies à gram négatif dans un service de médecine interne.

Among 31 patients with positive blood cultures for gram-negative bacilli seen in a department of internal medicine, 13 had at least 3 positive blood cultures from samples taken over more than 12 hours and were diagnosed as having septicemia (group I) ; 18 patients had less than three positive blood cultures over the same period or had several positive blood cultures over a shorter period and were diagnosed as having bacteremia (group II). There were no significant differences between these two groups concerning age, sex, fever, other clinical features, or biological findings. E. coli was recovered in 70 % of cases and was almost always related to urinary infection. 8 patients died (3 in group I, 5 in group II), 6 of whom had cirrhosis. The sensitivity of the pathogens to the main antibiotics is described. The most often used antibiotic combination was ampicillin-gentamycin. It is suggested that in departments receiving patients from outside the hospital rather than from intensive care units the ampicillin-gentamycin combination can be advocated as the first treatment. As there were no significant differences between patients with septicemia or bacteremia, in severe infections a single positive blood culture should be taken into account and discrimination between septicemia and bacteremia is useless.