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Il est désormais bien établi que l'altération des roches, comme celle des matériaux d'origine anthropique, n'est pas le seul fait de l'interaction avec une phase aqueuse purement minérale. Les composés organiques et l'activité des micro-organismes interviennent également, tant dans la dégradation que dans les minéralisations secondaires. Toutefois, compte tenu de la complexité des milieux réactionnels, il n'existe pas de validation convaincante du rôle de certaines bactéries sur la vitesse de dégradation des silicates complexes. L'objectif de ce travail était d'évaluer expérimentalement (pendant 133 jours) l'effet d'une seule bactérie largement répandue dans la nature (Pseudomonas aeruginosa) sur la vitesse de dégradation de quelques silicates d'intérêt environnemental. Les matériaux testés sont un mâchefer résultant de l'incinération d'ordures ménagères (MIOM), un vitrifiât de mâchefer industriel (JAP) et un verre basaltique (Basalte). Les expériences ont été réalisées en milieu stérile et en milieu biotique au cours desquelles le milieu de culture a été périodiquement renouvelé. Les résultats indiquent que les vitesses sont systématiquement plus grandes en milieu stérile qu'en milieu biotique, et cela dans des proportions allant de 40 à 60 % suivant l'élément et le matériau. Des différences sont toutefois constatées selon le matériau considéré. Le MIOM s'altère à une vitesse moyenne de 5,3×10-4g. m-2. j-1en milieu biotique et 7,6×10-4g. m-2. j-1en milieu stérile. La vitesse d'altération du verre JAP en présence de P. aeruginosaest de 7,7×10-4g. m-2. j-1et de 12,8×10-4g. m-2. j-1en l'absence de bactéries. Le Basalte s'altère avec une vitesse égale à 18,3×10-4g. m-2. j-1en biotique et 29,8×10-4g. m-2. j-1en stérile. Contrairement à ce qui a été décrit jusqu'à présent dans la littérature, cette étude montre que les bactéries jouent un rôle protecteur vis-à-vis des matériaux testés.

Today it is generally accepted that alteration of rocks as well as anthropogenic products is not only driven by the interaction with water or mineral aqueous solutions. Organic compounds and also micro-organisms are of importance for material degradation together with secondary mineralization. However, the exact role of some bacteria in these processes remains unclear in such complex systems. There is no convincing experimental validation of such phenomenon for silicate phases. The goal of the present work was to experimentally evaluate (during 133?days) the effect of one type of bacteria (Pseudomonas aeruginosa) on the alteration rate of some silicates of environmental interest. Experiments were conducted in biotic and abiotic conditions with a periodic renewal of the growth medium. The tested materials are a municipal solid waste incinerator bottom ash (MIOM), a vitrified industrial bottom ash (JAP) and a basaltic glass (Basalte). Results shows that the alteration rate are systematically higher in sterile condition than in biotic one in proportions going from?40 to?60% depending on element and material. The dissolution rate of MIOM is 5,3?10-4?g.m-2.d-1in biotic condition and 7,6?10-4?g.m-2.d-1in the sterile one. The vitrified bottom ash dissolution rate is 7,7?10-4?g.m-2.d-1in presence of P. aeruginosa and 12,8?10-4?g.m-2.d-1without bacteria. Basalte deteriorates with a rate of 18,3?10-4?g.m-2.d-1in biotic and 29,8?10-4?g.m-2.d-1in sterile system. Contrarily to previous results described in the literature, this study shows that bacteria have a protective effect on the tested materials. Il est d?sormais bien ?tabli que l'alt?ration des roches, comme celle des mat?riaux d'origine anthropique, n'est pas le seul fait de l'interaction avec une phase aqueuse purement min?rale. Les compos?s organiques et l'activit? des micro-organismes interviennent ?galement, tant dans la d?gradation que dans les min?ralisations secondaires. Toutefois, compte tenu de la complexit? des milieux r?actionnels, il n'existe pas de validation convaincante du r?le de certaines bact?ries sur la vitesse de d?gradation des silicates complexes. L'objectif de ce travail ?tait d'?valuer exp?rimentalement (pendant 133?jours) l'effet d'une seule bact?rie largement r?pandue dans la nature (Pseudomonas aeruginosa) sur la vitesse de d?gradation de quelques silicates d'int?r?t environnemental. Les mat?riaux test?s sont un m?chefer r?sultant de l'incin?ration d'ordures m?nag?res (MIOM), un vitrifi?t de m?chefer industriel (JAP) et un verre basaltique (Basalte). Les exp?riences ont ?t? r?alis?es en milieu st?rile et en milieu biotique au cours desquelles le milieu de culture a ?t? p?riodiquement renouvel?. Les r?sultats indiquent que les vitesses sont syst?matiquement plus grandes en milieu st?rile qu'en milieu biotique, et cela dans des proportions allant de?40 ? 60?% suivant l'?l?ment et le mat?riau. Des diff?rences sont toutefois constat?es selon le mat?riau consid?r?. Le MIOM s'alt?re ? une vitesse moyenne de?5,3?10-4?g.?m-2.?j-1en milieu biotique et?7,6?10-4?g.?m-2.?j-1en milieu st?rile. La vitesse d'alt?ration du verre JAP en pr?sence de P. aeruginosa est de 7,7?10-4?g.?m-2.?j-1et de 12,8?10-4?g.?m-2.?j-1en l'absence de bact?ries. Le Basalte s'alt?re avec une vitesse ?gale ??18,3?10-4?g.?m-2.?j-1en biotique et?29,8?10-4?g.?m-2.?j-1en st?rile. Contrairement ? ce qui a ?t? d?crit jusqu'? pr?sent dans la litt?rature, cette ?tude montre que les bact?ries jouent un r?le protecteur vis-?-vis des mat?riaux test?s.

One prerequisite for the virulence of Yersinia pestis, causative agent of bubonic plague, is the yersiniabactin (Ybt) siderophore-dependent iron transport system that is encoded within a high-pathogenicity island (HPI) within the pgm locus of the Y. pestis chromosome. Several gene products within the HPI have demonstrated functions in the synthesis or transport of Ybt. Here we examine the roles of ybtU and ybtT. In-frame mutations in ybtT or ybtU yielded strains defective in siderophore production. Mutant strains were unable to grow on iron-deficient media at 37 degrees C but could be cross-fed by culture supernatants from a Ybt-producing strain of Y. pestis. The ybtU mutant failed to express four indicator Ybt proteins (HMWP1, HMWP2, YbtE, and Psn), a pattern similar to those for other ybt biosynthetic mutants. In contrast, strains carrying mutations in ybtT or ybtS (a previously identified gene required for Ybt biosynthesis) produced all four proteins at wild-type levels under iron-deprived conditions. To assess the effects of ybtT, -U, and -S mutations on transcription of ybt genes, reporter plasmids with ybtP or psn promoters controlling lacZ expression were introduced into these mutants. Normal iron-regulated beta-galactosidase activity was observed in the ybtT and ybtS mutants, whereas a significant loss of expression occurred in the DeltaybtU strain. These results show that ybtT and ybtU genes are involved in the biosynthesis of the Ybt siderophore and that a ybtU mutation but not ybtT or ybtS mutations affects transcription from the ybtP and psn promoters.

The molecular mechanisms controlling bone extracellular matrix (ECM) deposition by differentiated osteoblasts in postnatal life, called hereafter bone formation, are unknown. This contrasts with the growing knowledge about the genetic control of osteoblast differentiation during embryonic development. Cbfa1, a transcriptional activator of osteoblast differentiation during embryonic development, is also expressed in differentiated osteoblasts postnatally. The perinatal lethality occurring in Cbfa1-deficient mice has prevented so far the study of its function after birth. To determine if Cbfa1 plays a role during bone formation we generated transgenic mice overexpressing Cbfa1 DNA-binding domain (DeltaCbfa1) in differentiated osteoblasts only postnatally. DeltaCbfa1 has a higher affinity for DNA than Cbfa1 itself, has no transcriptional activity on its own, and can act in a dominant-negative manner in DNA cotransfection assays. DeltaCbfa1-expressing mice have a normal skeleton at birth but develop an osteopenic phenotype thereafter. Dynamic histomorphometric studies show that this phenotype is caused by a major decrease in the bone formation rate in the face of a normal number of osteoblasts thus indicating that once osteoblasts are differentiated Cbfa1 regulates their function. Molecular analyses reveal that the expression of the genes expressed in osteoblasts and encoding bone ECM proteins is nearly abolished in transgenic mice, and ex vivo assays demonstrated that DeltaCbfa1-expressing osteoblasts were less active than wild-type osteoblasts. We also show that Cbfa1 regulates positively the activity of its own promoter, which has the highest affinity Cbfa1-binding sites characterized. This study demonstrates that beyond its differentiation function Cbfa1 is the first transcriptional activator of bone formation identified to date and illustrates that developmentally important genes control physiological processes postnatally.

CHOLINE acetyltransferase (ChAT) is the key enzyme responsible for the synthesis of the neurotransmitter acetylcholine and is reduced in various central neurodegenerative diseases. From a previously selected 12.6 kb human choline acetyltransferase (hChAT) genomic clone, we have identified and characterized a promoter region of 895 bp. Sequence analysis revealed the presence of a TATA-like box, a CAAT box and several putative regulatory responsive elements. Three transcription initiation sites were determined by primer extension analysis. The Northern blot of poly(A)+RNA, showed a single band of 2300 Nt in the human nucleus accumbens and facial nucleus. By using transient transfections into NE-1–115 and COS-1 cells of the 5′ flanking region of the hChAT gene we identified a sequence of 66 bp upstream of the transcription start site which confers responsiveness to proto-oncogenes c-Fos/c-Jun. These data suggest that the hChAT gene may be a physiological target of c-Fos/c-Jun and therefore may play a role in neuronal responses to various stimuli.

The Cbfa1gene, which encodes the transcription factor Osf2/Cbfa1 required for osteoblast differentiation in mouse and human, is mutated in cleidocranial dysplasia, a skeletal dysplasia. We describe here the isolation of the full-length human OSF2/ CBFA1 cDNAs, the genomic organization of the entire CBFA1 gene, its expression, and the existence of an alternative splicing event. Nucleotide sequence analysis of the human and mouse OSF2/CBFA1 cDNAs showed a 98% homology in the coding sequence and 96% in the 5′ untranslated (UTR) sequence. Analysis of CBFA1 genomic clones revealed that the 5′ UTR sequence of the human OSF2/CBFA1 cDNA lies 75 kb upstream of the originally described 5′ end of the gene. The existence of two OSF2/CBFA1 cDNAs is due to an alternative splicing event around exon 8 that affects the transcriptional activity of the protein. Northern blot analysis demonstrates that the expression of the human OSF2/CBFA1 gene is restricted to osteoblastic cells.

Les mutations d’AIPprédisposent aux adénomes hypophysaires, majoritairement somatotropes et chez le sujet jeune. Le rôle d’AIP dans le fonctionnement de l’axe somatotrope et la tumorigenèse hypophysaire reste toutefois mal connu. Les souris Aip+/–constituent le seul modèle physiopathologique in vivo décrit mais, en dehors de l’identification d’adénomes hypophysaires à l’histologie, leur phénotype a été peu caractérisé. Nous avons comparé la croissance somatique, la composition corporelle et la sécrétion de GH de souris mâles sauvages et Aip+/–suivies longitudinalement de 3 à 12 mois. Le poids des jeunes souris Aip+/–est supérieur à celui des souris sauvages, sans différence de taille naso-anale. Les animaux Aip+/–de 3 et 12 mois présentent une diminution de la masse grasse et une augmentation de la masse maigre suggérant un effet de la GH. L’analyse de la pulsatilité de GH sur 6h a montré une sécrétion accrue chez les souris Aip+/–de 12 mois par rapport aux souris sauvages, sans différence entre les taux d’IGF-I. La sécrétion de GH induite par la GHRH ex vivo ainsi que l’expression des transcrits hypophysaires de GH et des transcrits hypothalamiques de GHRH sont plus élevées chez les souris Aip+/–de 3 mois que chez les souris sauvages. En conclusion, les souris Aip+/–ne présentent pas de gigantisme ni d’acromégalie évidents aux âges étudiés. Contrairement à la pathologie humaine, le développement tumoral est tardif. La réponse accrue à la GHRH ainsi que sa surexpression hypothalamique suggèrent toutefois une hyperplasie somatotrope précédant l’apparition des adénomes, actuellement recherchée par immunohistochimie.

Cbfa1 is an essential transcription factor for osteoblast differentiation and bone formation. We investigated functional differences among three isoforms of Cbfa1: Type I (originally reported as Pebp2alphaA by Ogawa et al. (Ogawa, E., Maruyama, M., Kagoshima, H., Inuzuka, M., Lu, J., Satake, M., Shigesada, K., and Ito, Y. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 6859-6863), Type II (originally reported as til-1 by Stewart et al. (Stewart, M., Terry, A., Hu, M., O'Hara, M., Blyth, K., Baxter, E., Cameron, E., Onions, D. E., and Neil, J. C. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 8646-8651), and Type III (originally reported as Osf2/Cbfa1 by Ducy et al. (Ducy, P., Zhang, R., Geoffroy, V., Ridall, A. L., and Karsenty, G. (1997) Cell 89, 747-754). A reverse transcriptase-polymerase chain reaction analysis demonstrated that these isoforms were expressed in adult mouse bones. The transient transfection of Type I or Type II Cbfa1 in a mouse fibroblastic cell line, C3H10T1/2, induced the expression of alkaline phosphatase (ALP) activity. This induction was synergistically enhanced by the co-introduction of Xenopus BMP-4 cDNA. In contrast, the transient transfection of Type III cDNA induced no ALP activity. In C3H10T1/2 cells stably transfected with each isoform of Cbfa1, the gene expression of ALP was also strongly induced in cells transfected with Type I and Type II Cbfa1 but not in cells with Type III Cbfa1. Osteocalcin, osteopontin,and type I collagen gene expressions were induced or up-regulated in all of the cells stably transfected with each isoform of Cbfa1, and Type II transfected cells exhibited the highest expression level of osteocalcin gene. A luciferase reporter gene assay using a 6XOSE2-SV40 promoter (6 tandem binding elements for Cbfa1 ligated in front of the SV40 promoter sequence), a mouse osteocalcin promoter, and a mouse osteopontin promoter revealed the differences in the transcriptional induction of target genes by each Cbfa1 isoform with or without its beta-subunit. These results suggest that all three of the Cbfa1 isoforms used in the present study are involved in the stimulatory action of osteoblast differentiation, but they exert different functions in the process of osteoblast differentiation.

Cbfa1 is an essential transcription factor for osteoblast differentiation and bone formation. We investigated functional differences among three isoforms of Cbfa1: Type I (originally reported as Pebp2αA by Ogawa et al.(Ogawa, E., Maruyama, M., Kagoshima, H., Inuzuka, M., Lu, J., Satake, M., Shigesada, K., and Ito, Y. (1993) Proc. Natl. Acad. Sci. U. S. A.90, 6859–6863), Type II (originally reported astil-1by Stewart et al.(Stewart, M., Terry, A., Hu, M., O'Hara, M., Blyth, K., Baxter, E., Cameron, E., Onions, D. E., and Neil, J. C. (1997) Proc. Natl. Acad. Sci. U. S. A.94, 8646–8651), and Type III (originally reported asOsf2/Cbfa1by Ducy et al.(Ducy, P., Zhang, R., Geoffroy, V., Ridall, A. L., and Karsenty, G. (1997)Cell89, 747–754). A reverse transcriptase-polymerase chain reaction analysis demonstrated that these isoforms were expressed in adult mouse bones. The transient transfection of Type I or Type IICbfa1in a mouse fibroblastic cell line, C3H10T1/2, induced the expression of alkaline phosphatase (ALP) activity. This induction was synergistically enhanced by the co-introduction ofXenopus BMP-4cDNA. In contrast, the transient transfection of Type III cDNA induced no ALP activity. In C3H10T1/2 cells stably transfected with each isoform ofCbfa1,the gene expression of ALPwas also strongly induced in cells transfected with Type I and Type IICbfa1but not in cells with Type III Cbfa1. Osteocalcin, osteopontin,and type I collagengene expressions were induced or up-regulated in all of the cells stably transfected with each isoform of Cbfa1, and Type II transfected cells exhibited the highest expression level ofosteocalcingene. A luciferase reporter gene assay using a 6XOSE2-SV40 promoter (6 tandem binding elements for Cbfa1 ligated in front of the SV40 promoter sequence), a mouse osteocalcinpromoter, and a mouse osteopontinpromoter revealed the differences in the transcriptional induction of target genes by eachCbfa1isoform with or without its β-subunit. These results suggest that all three of the Cbfa1isoforms used in the present study are involved in the stimulatory action of osteoblast differentiation, but they exert different functions in the process of osteoblast differentiation.

Osteocalcin gene expression is initiated perinatally and is restricted to mature osteoblasts and odontoblasts. Because their pattern of expression is highly restricted, the osteocalcin genes are excellent tools to study osteoblast-specific gene expression. To define the mechanisms of osteocalcin cell-specific gene expression in vivo, we generated transgenic mice harboring deletion mutants of the promoter region of OG2, one of the mouse osteocalcin genes. We show here that only 647 base pairs of this promoter are sufficient to confer cell-specific and time-specific expression to a reporter gene in vivo. This promoter fragment contains two copies of OSE2. This osteoblast-specificcis-acting element binds Osf2, a recently characterized osteoblast-specific transcription factor (Ducy, P., Zhang, R., Geoffroy, V., Ridall, A. L., and Karsenty, G. (1997)Cell89, 747–754). We also demonstrate that the proximal OSE2 element is critical to confer an osteoblast-specific, developmentally regulated pattern of expression to a reporter gene. The other OSE2 element, located more upstream and presenting a lower affinity for Osf2, affects only weakly OG2promoter activity. These data demonstrate the crucial role of Osf2 in controlling osteocalcin gene expression. Since osteocalcin synthesis is a hallmark of the differentiated osteoblast phenotype, these results suggest that, beyond its developmental function, Osf2 is also required for the maintenance of the osteoblast phenotype postnatally.

The plea of illegality as a limb of incidental review alongside the preliminary ruling procedure is examined in light of its raison d'être, nature, ratione materiae and personae scope and its interrelated characteristics with other remedies and procedures in the EU judicial system. This article considers the origin of anomalies in the inconsistent case law reaching different conclusions with regard to standing of different applicants on a selective basis in the transposition of national procedure of exception d'illegalité into the Rome Treaty with a general wording. It is argued that the broad interpretation of ratione personae scope of the procedure on the basis of the wording of Article 277 TFEU requires, in parallel, relaxation of the strict application of the admissibility requirements towards individual applications especially where irregularities might become apparent after the concrete application of the general act in order to prevent from carrying privileged or non-privileged status of applicants under the action for annulment to the plea of illegality. [ABSTRACT FROM AUTHOR]

An effective method for preventing bone loss is by promoting osteoblast differentiation and bone formation. While dexamethasone has been routinely used as a classical inducer for osteoblast differentiation, limitations have been observed with its usage, including its varied effects on expression of osteoblast genes in different species and its potentials in suppressing osteoblastic differentiation and mineralization. In this study, we assessed the ability of flavonoid icariin in enhancing differentiation and mineralization of cultured rat primary osteoblasts in the absence of dexamethasone. It was found that, compared to the non-stimulated control, icariin at 10-5 M produced a higher alkaline phosphatase activity, more and larger areas of alkaline phosphatase-positive colonies (CFU-FALP) and mineralized nodules, more osteocalcin secretion and calcium deposition, higher levels of mRNA expression of alkaline phosphatase, osteoblastic transcription factors osterix and runt-related transcription factor 2, and collagen 1α, higher levels of protein expression of collagen 1α, alkaline phosphatese, osterix, and runt-related transcription factor 2. In addition, icariin at 10-5 M was always more potent than dexamethasone at its optimal concentration of 10-8 M on the above osteoblast differentiation and mineralization markers. Taken together, our studies demonstrated that icariin has a pronounced ability in promoting osteoblast differentiation in vitro in the absence of dexamethasone. [ABSTRACT FROM AUTHOR]

This section offers news briefs concerning lawsuits in the U.S. The Tenth Circuit affirmed denial of habeas corpus relief to James Diestel, a paranoid schizophrenic, who claimed that eh was legally insane when the crime was committed. A Pennsylvania court affirmed the suspension of the license of psychiatrist Luz Perez-Rocha who was alcohol dependent. An Oregon appeals court reversed an involuntary commitment order after it concluded that the respondent, due to depression, was not a danger to herself.

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Pseudomonas aeruginosa is a human opportunistic pathogen ubiquitously distributed in nature. Under iron-limiting conditions, this organism secretes pyoverdine, which aids in iron chelation. Ferripyoverdine complexes are recognized by ferripyoverdine transporters located at the outer membrane of P. aeruginosa. These ferripyoverdine transporter genes (fpvAI, II, and III) were characterized previously, and their sequences were determined by cloning techniques. The purpose of this study was to use the polymerase chain reaction (PCR) for the determination of about 2.5 kb gene sequence of the ferripyoverdine receptor genes (fpvA types I, IIa, IIb, and III, and fpvB) in clinical and environmental isolates of P. aeruginosa. This was achieved by using a series of external and internal primers designed both for the amplification and sequencing of these genes and these sequencesare presented., Introduction Pseudomonas aeruginosa produces three different pyoverdines, types I-III (Cornelis et al., 1989), which are able to chelate iron and form ferripyoverdine complexes that are recognized and transported by different [...]

Pseudomonas aeruginosa, found to be distributed in soil, water, and marine environments and pathogenic to both humans and animals, is gaining much popularity in clinical scientific research where it accounts [...]