Comparison between qualitative and semiquantitative catheter-tip cultures: laboratory diagnosis of catheter-related infection in newborns

Este estudo prospectivo avaliou os métodos semiquantitativo e qualitativo de cultura de cateter para o diagnóstico de infecção relacionada a cateter (IRC) em recém-nascidos (RN). Foram incluídas pontas de cateteres provenientes de recém-nascidos internados na Unidade Neonatal do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP. Foram utilizadas as técnicas semiquantitativa e qualitativa de cultura de cateter. Para o diagnóstico de IRC, os microrganismos isolados das culturas de cateteres e de hemoculturas periféricas foram identificados e submetidos ao teste de sensibilidade a antimicrobianos. O padrão ouro correspondeu ao diagnóstico de certeza de IRC, com o isolamento do mesmo microrganismo (espécie e perfil de sensibilidade a antimicrobianos) isolado em hemocultura periférica. Foram estudados 85 cateteres provenientes de 63 RN. A cultura semiquantitativa, embora tenha apresentado menor sensibilidade (90%), apresentou uma maior especificidade (71%) em comparação à sensibilidade de 100% e especificidade de 60% encontradas na cultura qualitativa. Através da identificação dos microrganismos obtidos nas culturas de cateteres, observou-se uma predominância de espécies de Estafilococos coagulase-negativa (ECN). A espécie Staphylococcus epidermidis foi a prevalente (77,5%) nos cateteres com culturas semiquantitativas positivas. Dos 11 episódios de IRC diagnosticados, 8 (72,7%) foram associados a espécies de ECN, dos quais 6 eram da espécie S. epidermidis. Também foram detectados dois casos de IRC por S. aureus e um caso por Candida parapsilosis. O método de cultura semiquantitativo cateter apresentou vantagens para o diagnóstico de IRC em RN quando comparado com o método qualitativo tradicional.

Usefulness of catheter tip culture in the diagnosis of neonatal infections

Objective: To determine the number of colony-forming units (CFU) that best correlates with catheter-related infections (CRI) in newborns.Methods: This was a prospective study of semiquantitative cultures of catheter tips obtained from newborns in the neonatal unit at Faculdade de Medicina de Botucatu, state of São Paulo, Brazil. The microorganisms isolated from catheter and peripheral blood cultures were identified and submitted to a drug susceptibility test. The optimal cutoff point was determined by the receiver operating characteristic (ROC) curve.Results: A total of 85 catheters obtained from 63 newborns were studied. Staphylococcus epidermidis was the predominant species in the catheters (75%). Eight of 11 (72.7%) CRI episodes were associated with coagulase-negative staphylococci, six of which were of the S. epidermidis type. ROC curve analysis indicated that the optimal cutoff point for the diagnosis of CRI was 122 CFU.Conclusions: The cutoff point of 122 CFU correlated best with the diagnosis of CRI in newborns.

Influence of Implant Inclination Associated With Mandibular Class I Removable Partial Denture

The aim of this study was to use two-dimensional finite element method to evaluate the displacement and stress distribution transmitted by a distal extension removable partial denture (DERPD) associated with an implant placed at different inclinations (0, 5, 15, and 30 degrees) in the second molar region of the edentulous mandible ridge. Six hemimandibular models were created: model A, only with the presence of the natural tooth 33; model B, similar to model A, with the presence of a conventional DERPD replacing the missing teeth; model C, similar to the previous model, with a straight implant (0 degrees) in the distal region of the ridge, under the denture base; model D, similar to model C, with the implant angled at 5 degrees in the mesial direction; model E, similar to model C, with the implant angled at 15 degrees in the mesial direction; and model F, similar to ME, with the implant angled at 30 degrees in the mesial direction. The models were created with the use of the AutoCAD 2000 program (Autodesk, Inc, San Rafael, CA) and processed for finite element analysis by the ANSYS 8.0 program (Swanson Analysis Systems, Houston, PA). The force applied was vertical of 50 N on each cusp tip. The results showed that the introduction of the RPD overloaded the supporting structures of the RPD and that the introduction of the implant helped to relieve the stresses of the mucosa alveolar, cortical bone, and trabecular bone. The best stress distribution occurred in model D with the implant angled at 5 degrees. The use of an implant as a support decreased the displacement of alveolar mucosa for all inclinations simulated. The stress distribution transmitted by the DERPD to the supporting structures was improved by the use of straight or slightly inclined implants. According to the displacement analysis and von Mises stress, it could be expected that straight or slightly inclined implants do not represent biomechanical risks to use.

Evaluation of the influence of location of osseointegrated implants associated with mandibular removable partial dentures

Purpose: The aim of this research was to assess, by means of, the bi-dimensional finite element method, the best implant location in the alveolar edge, through stress distribution and support structure displacement of a distal extension removable partial denture associated with an osseointegrated implant of 10.0 x .75 mm, acting as abutment for the denture base.Methods and Materials: Five models in sagittal cut were used to represent: model A-hemi arch containing natural tooth 33 and the distal alveolar edge; model B-similar to model A, but with a conventional removable partial denture to replace the absent teeth; model C (MC)-similar to the previous one, with an implant in the distal region of the edge under the denture base; model D-similar to MC, with the implant in the central region of the edge; model E-similar to MC, with an implant in the mesial region of the edge. With the aid of the finite element program ANSYS 8.0, the models were loaded with strictly vertical forces of 50 N on each cusp tip. Displacement and von Mises Maps were plotted for visualization of results.Results: The introduction of implant diminished the tendency of intrusion of the removable partial denture in all situations. The maximum stress was observed on implant in all situations. Approximating implant in direction of support teeth was benefit for stress distribution.Conclusion: Model D presented the lowest value for maximum tendency to displacement when compared with those found in the other models; model E demonstrated better relief with regard to demand from the abutment tooth; locating the implant near of the abutment tooth influenced positively the distribution of stresses on the analyzed structures.

Effects of laser-weld joint opening size on fatigue strength of Ti-6Al-4V structures with several diameters

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of light guide tip used in the photo-activation on degree of conversion and hardness of one nanofilled dental composite

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Label-free DNA detection of hepatitis C virus based on modified conducting polypyrrole films at microelectrodes and atomic force microscopy tip-integrated electrodes

We present a new strategy for the label-free electrochemical detection of DNA hybridization for detecting hepatitis C virus based on electrostatic modulation of the ion-exchange kinetics of a polypyrrole film deposited at microelectrodes. Synthetic single-stranded 18-mer HCV genotype-1-specific probe DNA has been immobilized at a 2,5-bis(2-thienyl)-N-(3-phosphoryl-n-alkyl)pyrrole film established by electropolymerization at the previously formed polypyrrole layer. HCV DNA sequences (244-mer) resulting from the reverse transcriptase-linked polymerase chain reaction amplification of the original viral RNA were monitored by affecting the ion-exchange properties of the polypyrrole film. The performance of this miniaturized DNA sensor system was studied in respect to selectivity, sensitivity, and reproducibility. The limit of detection was determined at 1.82 x 10(-21) mol L-1. Control experiments were performed with cDNA from HCV genotypes 2a/c, 2b, and 3 and did not show any unspecific binding. Additionally, the influence of the spacer length of 2,5-bis(2-thienyl)-N-(3-phosphoryl-n-alkyl)pyrrole on the behavior of the DNA sensor was investigated. This biosensing scheme was finally extended to the electrochemical detection of DNA at submicrometer-sized DNA biosensors integrated into bifunctional atomic force scanning electrochemical microscopy probes. The 18-mer DNA target was again monitored by following the ion-exchange properties of the polypyrrole film. Control experiments were performed with 12-base pair mismatched sequences.

Rolling technique for treatment of left displacement of the large colon in horses: 11 cases (2004-2009)

Durante o período de 2004 a 2009, 11 animais foram tratados para o deslocamento à esquerda do cólon maior, por meio da técnica de rolamento sob anestesia geral, com uma técnica distinta das demais previamente descritas. A seleção dos casos foi baseada nos achados da palpação retal e confirmada ultrassonograficamente. Nove animais foram tratados com sucesso e dois foram submetidos ao tratamento cirúrgico após três tentativas de rolamento. Não foram observadas complicações decorrentes do procedimento a curto e a longo prazos. Somente um animal apresentou recidiva do quadro clínico 10 meses após o tratamento e foi novamente submetido ao rolamento. Apesar da diferença com relação às outras técnicas, esta também se mostrou eficaz. O rolamento, mesmo quando realizado mais de uma vez, mostrou ser um procedimento seguro, porém enfatiza-se a necessidade de cuidados especiais aos animais após a sua realização, pois medidas emergenciais podem ser necessárias caso complicações decorrentes desta técnica ocorram.

Distribution transformers modeling with angular displacement: actual values and per unit analysis

In this work a detailed modeling of three-phase distribution transformers aimed at complementing well-known approaches is presented. Thus, incidence of angular displacement and tapping is taken into account in the proposed models, considering both actual values and per unit. The analysis is based on minimal data requirement: solely short-circuit admittance is needed since three-phase transformers are treated as non-magnetically-coupled single-phase transformers. In order to support the proposed methodology, results obtained through laboratory tests are presented.

The tadpole of Scinax catharinae (Anura : Hylidae) with description of the internal oral morphology, and a review of the tadpoles from the Scinax catharinae group

We present a description of the external morphology and internal oral features of the tadpole of Scinax catharinae and comparisons with the known tadpoles of the S. catharinae group. Two characters of the external morphology present some intraspecific variation: the row of submarginal papillae, which can be uniseriate or absent, and the tail tip, which can be large or small, truncated or not. That said, the tadpole of S. catharinae presents some distinguishing features that differentiate it from other tadpoles in the S. catharinae group: i) the marginal row of papillae with alternate disposition, ii) the spiracle opening on the midline of the body, iii) longest snout length, and iv) largest interorbital distance. The studied species were segregated into five ecomorphological guilds, characterized by external morphological features, tadpole habitat use and vegetation formation of species range. The taxonomy of the S. catharinae group is complex, due to the morphological similarities among the adults. Larval characters could help in the resolution of the taxonomic and phylogenetic complexities, since the morphological differences among the tadpoles in this group seem more conspicuous than those found among the adults.

An implicit BEM formulation to model strong discontinuities in solids

A boundary element method (BEM) formulation to predict the behavior of solids exhibiting displacement (strong) discontinuity is presented. In this formulation, the effects of the displacement jump of a discontinuity interface embedded in an internal cell are reproduced by an equivalent strain field over the cell. To compute the stresses, this equivalent strain field is assumed as the inelastic part of the total strain. As a consequence, the non-linear BEM integral equations that result from the proposed approach are similar to those of the implicit BEM based on initial strains. Since discontinuity interfaces can be introduced inside the cell independently on the cell boundaries, the proposed BEM formulation, combined with a tracking scheme to trace the discontinuity path during the analysis, allows for arbitrary discontinuity propagation using a fixed mesh. A simple technique to track the crack path is outlined. This technique is based on the construction of a polygonal line formed by segments inside the cells, in which the assumed failure criterion is reached. Two experimental concrete fracture tests were analyzed to assess the performance of the proposed formulation.

Erbium- and ytterbium-doped sol-gel SiO2-HfO2 crack-free thick films onto silica on silicon substrate

Aware of the difficulties in applying sol-gel technology on the preparation of thin films suitable for optical devices, the present paper reports on the preparation of crack-free erbium- and ytterbium-doped silica: hafnia thick films onto silica on silicon. The film was obtained using a dispersion of silica-hafnia nanoparticles into a binder solution, spin-coating, regular thermal process and rapid thermal process. The used methodology has allowed a significant increase of the film thickness. Based on the presented results good optical-quality films with the required thickness for a fiber matching single mode waveguide were obtained using the erbium- and ytterbium-activated sol-gel silica:hafnia system. The prepared film supports two transversal electric modes at 1550 nm and the difference between the transversal electric mode and the transversal magnetic mode is very small, indicating low birefringence. Photoluminescence of the I-4(13/2) -> I-4(15/2) transition of erbium ions shows a broad band centered at 1.53 mu m with full width at a half maximum of 28 nm. Up-conversion emission was carried out under different pump laser powers, and just one transition at red region was observed. (c) 2006 Elsevier B.V. All rights reserved.

Effect of handpiece tip design on the cutting efficiency of an air abrasion system

Purpose : the aim of this study was to evaluate the effect of nozzle angle and tip diameter on the cutting efficiency of an air abrasion system. Materials and Methods: Thirty-six extracted human third molars were air-abraded with the PrepStar microabrasion machine using a handpiece with either 80degrees or 45degrees nozzle angles with 0.38 or 0.48 nun tip orifice diameters. The following parameters were held constant: abrasive particle size (27 mum), air pressure (80 psi), distance (2 mm.) and duration (15 seconds). The cutting efficiency was compared using enamel, dentin and cementum substrates. Width and depth of the cutting patterns were analyzed and measured using scanning electron micrographs. Results: Statistical analysis using three-way ANOVA and Duncan's Multiple Range test revealed that the width of the cuts was significantly greater when the cavities were prepared using the 45degrees nozzle angle. Significantly deeper cavities were produced with the 80degrees nozzle angle. The tip orifice of the nozzle influenced the cutting efficiency in softer substrates, dentin and cementum. Precise removal of hard tissue is best accomplished using the 80degrees angle nozzle tips for all types of tooth surfaces, enamel, dentin and cementum.