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C Pierre

Publications and source records attributed to C Pierre.

At least 19 recordsLinked to original sources
PubMed2006

Microbial community structure in three deep-sea carbonate crusts.

Carbonate crusts in marine environments can act as sinks for carbon dioxide. Therefore, understanding carbonate crust formation could be important for understanding global warming. In the present study, the microbial communities of three carbonate crust samples from deep-sea mud volcanoes in the eastern Mediterranean were characterized by sequencing 16S ribosomal RNA (rRNA) genes amplified from DNA directly retrieved from the samples. In combination with the mineralogical composition of the crusts and lipid analyses, sequence data were used to assess the possible role of prokaryotes in crust formation. Collectively, the obtained data showed the presence of highly diverse communities, which were distinct in each of the carbonate crusts studied. Bacterial 16S rRNA gene sequences were found in all crusts and the majority was classified as alpha-, gamma-, and delta- Proteobacteria. Interestingly, sequences of Proteobacteria related to Halomonas and Halovibrio sp., which can play an active role in carbonate mineral formation, were present in all crusts. Archaeal 16S rRNA gene sequences were retrieved from two of the crusts studied. Several of those were closely related to archaeal sequences of organisms that have previously been linked to the anaerobic oxidation of methane (AOM). However, the majority of archaeal sequences were not related to sequences of organisms known to be involved in AOM. In combination with the strongly negative delta 13C values of archaeal lipids, these results open the possibility that organisms with a role in AOM may be more diverse within the Archaea than previously suggested. Different communities found in the crusts could carry out similar processes that might play a role in carbonate crust formation.

Anaerobiosis↗
PubMed2001

[Infectious crystalline keratopathy: a case report].

We report a case of perforated infectious crystalline keratopathy in a 88-year-old woman. Corneal surgery like keratoplasty and topical corticosteroids are the main causative factors present in the rare reported cases. Clinically, the anterior layers of cornea exhibit slowly progressive stellate infiltrates. "Viridans streptococci" are the most common micro-organisms involved but their culture for identification is difficult. As compared to cultures, histologic examination is more sensitive for diagnosis, by showing clusters of bacteria in the corneal stroma with no inflammatory response.

Administration, Topical↗
PubMed2000

Improved antibacterial activities of coumarin antibiotics bearing 5',5'-dialkylnoviose: biological activity of RU79115.

A new series of coumarin inhibitors of DNA gyrase B bearing a N-propargyloxycarbamate at C-3' of various 5',5'-dialkylnoviose, including RU79115, were synthesised and their antibacterial activities have been delineated. Introduction of dialkyl substituents at 5'5'-position of noviose leads to coumarin analogues with improved in vitro and in vivo antibacterial activity.

Anti-Bacterial Agents↗
PubMed2000

Nephrogenic adenofibroma in a young child.

Nephrogenic adenofibroma is a benign renal tumor in children and young adults described by Hennigar and Beckwith in 1992. Seven cases have been described, and we report the first case in an 11-month-old child, in good health, revealed by a macroscopic hematuria. Nephrogenic adenofibroma is an unusual tumor, which was difficult to distinguish from nephroblastoma and mesoblastic nephroma. Beckwith makes a distinction between this principal differential diagnosis in child renal tumors based upon morphologic and immunohistochemical patterns. In our observation, the diagnosis remained difficult and needed several reviews of our case. Beckwith proposed the final diagnosis: nephrogenic adenofibroma with stromal predominance. The prognosis is excellent and no treatment is indicated. A FISH analysis of the tumor cells found a trisomy 11. Trisomy 11 has been reported in mesoblastic nephroma as the most frequent chromosomal abnormality. This finding in tumor cells provides an argument for excluding the diagnosis of nephroblastoma but can not clarify the difference between nephrogenic adenofibroma and mesoblastic nephroma.

Adenofibroma↗
PubMed2000

Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector.

We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The transgene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications.

Actins↗
PubMed1998

Paradoxical metabolic response of the human brain to a single electroconvulsive shock.

Regional brain protein synthesis was evaluated with positron emission tomography (PET) and L-(S-[11C]methyl)methionine ([11C]MET) in depressive patients, before and 3 h after an electroconvulsive shock (ECS), when energy supply is restored, and in healthy volunteers. Depressive patients presented apparent lower protein synthesis than normals, in agreement with known reduction of cerebral activity. In contrast, ECS resulted in a significant increase (56%, P < 0.05) in global cortical protein synthesis. This paradoxical hyperactivation of cellular protein metabolism in response to seizures and the fact that synaptic activity is further reduced after electroconvulsive therapy (ECT), may provide new insights for understanding the mechanism of action of ECT.

Adult↗
PubMed1998

[Helminth diagnosis in pathologic anatomy].

Most publications devoted to diagnosis of helminths emphasize characteristic parasitological features. Histological feature are seldom described in detail. The purpose of this study was to propose a diagnostic method suitable for use by histologists who, unlike parasitologists, do not visualize the whole worm but rather pieces randomly scattered over a slide. It is relatively easy to distinguish helminths which have smooth muscle, no respiratory or circulatory system, and no coelom from arthropods which have striated muscle, both respiratory and circulatory systems, and coelom. At the adult stage, roundworms or nemathelminths present an external cuticle that may have patterned markings. The visceral cavity is empty. Adults can dwell either in the intestine in which case they are oviparous (oxyuris, ascaris, Ancylostoma, Strongyloides stercoralis, Trichuris...) or in tissue in which case they are viviparous (filaria). Larva of some species can be found in tissues. Adult tape-worms are devoid of cuticle and have a mesenchymatous visceral cavity. Cestodes which are segmented and have no digestive tract (taenias) are readily distinguishable from trematodes which are not segmented and have a digestive tract (faciolasis) Some cestodes unable thrive in man can cause cyst formation (hydatidosis, sparganosis, cysticercosis, coenurosis). On the basis of symptoms and histological features, it is usually possible to diagnose the genus and even the species of the offending helminth provided that the parasite has not been excessively damaged and that a sufficient number of sections are available.

Animals↗
PubMed1998

[Hamartomatous adiposity of the thyroid].

Report of one case of hamartomatous adiposity of the thyroid gland. Only eight cases have been reported. The lesion is composed of thyroid tissue and mature adipose elements. Previously reported cases are reviewed and the pathogenesis is discussed.

Adipose Tissue↗
PubMed1997

Emergence of vancomycin resistance in the genus Streptococcus: characterization of a vanB transferable determinant in Streptococcus bovis.

Streptococcus bovis NEM760 was isolated from a stool swab collected on admission from a patient as surveillance for vancomycin-resistant enterococci. Strain NEM760 was identified as S. bovis by conventional biochemical methods and partial sequence analysis of its 16S rRNA. This strain was resistant to a low level of vancomycin (MIC, 64 micrograms/ml) but was susceptible to teicoplanin (MIC, 1 micrograms/ml), and vancomycin induced resistance to both glycopeptides. The presence of a vanB-related gene in NEM760 was demonstrated in a PCR assay which enabled specific amplification of a 635-hp internal segment of vanB. Sequence analysis of the corresponding PCR product revealed that it was highly homologous (96% identity) to the prototype vanB sequence of Enterococcus faecalis V583. The VanB resistance of determinant of S. bovis NEM760 was transferred by conjugation to E. faecalis and Enterococcus faecium at a similar frequency of 2 x 10(-5) per donor. SmaI-digested genomic DNAs of independently obtained transconjugants of E. faecalis and E. faecium were analyzed by pulsed-field gel electrophoresis and Southern hybridization with a vanB DNA probe. The electrophoretic and hybridization patterns obtained with all transconjugants of the same species were indistinguishable and revealed vanB-containing chromosomal insertions of approximately 100 kb. These results suggest that the genes mediating VanB-type resistance in S. bovis NEM760 are part of large transferable genetic elements. The results presented in the report demonstrate for the first time the role of streptococci in the dissemination of vancomycin resistance among gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed1997

[Retiform hemangioendothelioma].

Hemangioendotheliomas are vascular tumors of intermediate malignancy considered as low-grade angiosarcomas. The authors report two cases of a distinctive type, named retiform hemangioendothelioma because of its particular morphologic features, and recently delineated by Calonje and al. This tumor of the skin recurs frequently but has a very low metastatic rate.

Adult↗
PubMed1997

[Multifocal epithelioid angiosarcoma of the small intestine. Apropos of a case].

A case of angiosarcoma in the small bowel is reported. There were multifocal lesions in the duodeno-jejunum with peritoneal metastasis, revealed by an hemorrhagic syndrome. This tumor rare in the gastro-intestinal tract was epithelioïd. The authors present an histochemical and immunohistochemical study with a review of the literature.

Aged↗