RESUMEN
3D printing is a new manufacturing technology that produces high-fidelity models of complex structures from 3D computer-aided design data. Radiology has been particularly quick to embrace the new technology because of the wide access to 3D datasets. Models have been used extensively to assist orthopedic, neurosurgical, and maxillofacial surgical planning. In this report, we describe methods used for 3D printing of the fetal brain by using data from in utero MR imaging.
Asunto(s)
Encéfalo/diagnóstico por imagen , Feto/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Impresión Tridimensional , Adulto , Femenino , Humanos , Modelos Anatómicos , Embarazo , Diagnóstico PrenatalRESUMEN
Background Skilled managers are an important component of quality improvement (QI) infrastructure, but there has been little evaluation of QI infrastructure, which is needed to guide enhancement of this capacity. Methods Quality managers at 97 acute care hospitals in Ontario, Canada, were surveyed by mail to describe how their roles were integrated with QI performance objectives. Binary and scaled responses were analysed quantitatively, and open-ended responses were analysed thematically. Results The response rate was 79.4%. Many QI managers were new to their role and had no support staff despite responsibility for multiple portfolios. Respondents thought that QI objectives should be less reactive to hospital executives or boards, adverse events or demands from government and accreditation bodies, and recommended that dedicated QI managers proactively apply explicit strategic plans and engage executives and clinicians. Findings were consistent regardless of rank, staffing or hospital type. Those with master's training and greater experience were more involved in strategic planning, data analysis and communication. Conclusions QI is not well resourced in most acute care hospitals in Ontario. To develop QI capacity, investment and QI training may be required. Research should empirically establish objective performance measures of QI capacity to guide investment and evaluation.
Asunto(s)
Administradores de Hospital , Hospitales/normas , Garantía de la Calidad de Atención de Salud , Humanos , Entrevistas como Asunto , OntarioRESUMEN
Antimycin A is an inhibitor of cytochrome bc1 complexes acting at the quinone reducing site (Qi) of the cytochrome b subunit. We report here the isolation and molecular characterization of two spontaneous mutants of the purple non-sulfur bacterium Rhodospirillum rubrum resistant to this inhibitor. In the two mutants antimycin A resistance was found to be conferred by replacement of an aspartate residue at position 243 of the cytochrome b polypeptide chain, in one case by histidine and in the other by glutamate. The mutants exhibit cross-resistance to aurachin C but not to aurachin D. The exchange of Asp-243 does not only diminish the antimycin sensitivity of the isolated cytochrome bc1 complexes but also has effects on the function of the quinone reducing site (Qi). Oxidant-induced reduction of cytochrome b, requiring addition of antimycin A in the wild type, is already at a maximum in the absence of antimycin A. This indicates a diminished electron flow between heme b-566 and ubiquinone at the quinone reducing site (Qi) of cytochrome b.
Asunto(s)
Antimicina A/farmacología , Farmacorresistencia Microbiana/genética , Rhodospirillum rubrum/genética , Secuencia de Aminoácidos , Secuencia de Bases , Grupo Citocromo b/antagonistas & inhibidores , Grupo Citocromo b/genética , Complejo III de Transporte de Electrones/antagonistas & inhibidores , Complejo III de Transporte de Electrones/genética , Metacrilatos , Datos de Secuencia Molecular , Quinolonas/farmacología , Rhodospirillum rubrum/efectos de los fármacos , Tiazoles/farmacologíaAsunto(s)
Antimicina A/análogos & derivados , Grupo Citocromo b/genética , Farmacorresistencia Microbiana/genética , Complejo III de Transporte de Electrones/metabolismo , Mutación Puntual , Rhodospirillum rubrum/efectos de los fármacos , Secuencia de Aminoácidos , Antimicina A/toxicidad , Ácido Aspártico , Complejo III de Transporte de Electrones/genética , Complejo III de Transporte de Electrones/aislamiento & purificación , Genes Fúngicos , Glutamatos , Ácido Glutámico , Histidina , Rhodospirillum rubrum/enzimología , Rhodospirillum rubrum/genéticaRESUMEN
A cytochrome bc1-complex of Rs. rubrum was isolated and the three subunits were purified to homogeneity. The N-terminal amino acid sequence of the purified subunits was determined by automatic Edman degradation. The pet genes of Rhodospirillum rubrum coding for the three subunits of the cytochrome bc1-complex were isolated from a genomic library of Rs. rubrum using oligonucleotides specific for conserved regions of the subunits from other organisms and a heterologous probe derived from the genes for the complex of Rb. capsulatus. The complete nucleotide sequence of a 5500 bp SalI/SphI fragment is described which includes the pet genes and three additional unidentified open reading frames. The N-terminal amino acid sequence of the isolated subunits was used for the identification of the three genes. The genes encoding the subunits are organized as follows: Rieske protein, cytochrome b, cytochrome c1. Comparison of the N-terminal protein sequences with the protein sequences deduced from the nucleotide sequence showed that only cytochrome c1 is processed during transport and assembly of the three subunits of the complex. Only the N-terminal methionine of the Rieske protein is cleaved off. The similarity of the deduced amino acid sequence of the three subunits to the corresponding subunits of other organisms is described and implications for structural features of the subunits are discussed.