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1.
Appl Environ Microbiol ; 79(7): 2484-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23377935

RESUMO

Small-subunit (SSU) rRNA gene sequences associated with the phylum Armatimonadetes were analyzed using multiple phylogenetic methods, clarifying both the phylum boundary and the affiliation of previously ambiguous groupings. Here we define the Armatimonadetes as 10 class-level groups and reclassify two previously associated groups as candidate divisions WS1 and FBP.


Assuntos
Bactérias/classificação , Bactérias/genética , Filogenia , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
2.
Lipids ; 46(12): 1155-61, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21805326

RESUMO

A Gram-negative, aerobic, pink-pigmented, rod-shaped bacterium Chthonomonas calidirosea (strain T49(T)) with an optimal temperature for growth of 68 °C, isolated from soil samples from Hell's Gate in the Tikitere geothermal system (New Zealand), was the first cultivated bacterium of the novel phylum Armatimonadetes (formerly candidate division OP10). The lipid composition of C. calidirosea presents a number of unusual features both in the fatty acids and polar lipids. This contribution reports on the fatty acid profile of C. calidirosea. Transmethylation of bacterial biomass yielded fatty acid methyl esters and hydrocarbons, including squalene, partially hydrogenated squalenes, and diploptene. The only type of unsaturation found in C. calidirosea fatty acids was cis-Δ5, as revealed by GCMS of dimethyl disulfide (DMDS) adducts, and the lack of trans-unsaturation absorbance at 960-980 cm(-1) in the IR spectrum of fatty acids methyl esters. An unidentified component X with ECL 16.86 (BP1) and ECL 17.27 (BP20) was also observed, with molecular ion at m/z 282 ("17:1"). X did not form DMDS adducts, nor was affected by mild hydrogenation conditions, indicating the likely presence of a ring rather than unsaturation. The presence of a cyclopropane ring with cis-stereochemistry was confirmed by the (1)H-NMR spectrum. Hydrogenation of X in acetic acid resulted in formation of straight chain 17:0, 5-methyl- and 6-methyl-16:0 fatty acid methyl esters, thus confirming the structure of a novel 5,6-methylene hexadecanoic acid. The major fatty acids of a solid media-grown C. calidirosea were as follows (in weight % of total fatty acids): 16:0 (25.8), i17:0 (19.3), ai17:0 (13.5), 16:1∆5 (8.8), i17:1∆5 (6.8), 5,6-methylene 16:0 (5.2), i16:0 (4.4), 18:0 (3.6), 18:1∆5 (3.2).


Assuntos
Ácidos Graxos/análise , Bactérias Aeróbias Gram-Negativas/química , Fontes Termais/microbiologia , Cromatografia em Camada Fina , Meios de Cultura , Ciclopropanos/análise , Dissulfetos/química , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Aeróbias Gram-Negativas/isolamento & purificação , Bactérias Aeróbias Gram-Negativas/metabolismo , Temperatura Alta , Espectroscopia de Ressonância Magnética , Nova Zelândia , Esqualeno/análise , Triterpenos/análise
3.
Clin Radiol ; 57(1): 18-28, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11798198

RESUMO

Most osteochondromas are asymptomatic and incidental with typical radiographic characteristics. When symptomatic, complications due to space-occupying effects, mechanical deformity, or malignant transformation are usually the underlying causes. This article addresses the imaging strategy for their identification and evaluation.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Osteocondroma/diagnóstico por imagem , Neoplasias Ósseas/complicações , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/etiologia , Humanos , Imageamento por Ressonância Magnética , Síndromes de Compressão Nervosa/diagnóstico por imagem , Síndromes de Compressão Nervosa/etiologia , Osteocondroma/complicações , Tomografia Computadorizada por Raios X , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/etiologia
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