不同临床标本微生物检验的阳性率结果对比研究

目的：探讨不同临床标本微生物检验的阳性率结果及其对比分析。方法：比较2010-2012年20000份临床标本（呼吸道标本、血培养标本、其他非呼吸道标本，以及大便标本）的微生物检验阳性率，并对其结果进行回顾性分析。结果：与2010-2011年相比，2011-2012年呼吸道标本和其他非呼吸道标本的微生物检验阳性率明显降低，而血培养标本阳性率显著升高，P〈O．05，差异有统计学意义。结论：针对不同临床标本的微生物检验阳性率，寻找其原因，为临床疾病的诊断及预后判断。提供客观依据。     

Estudio comparativo de las 2 versiones de un inmunoanálisis comercializado para la monitorización terapéutica de adalimumab en artritis reumatoide

ObjectiveTo describe the results of the comparative study between both versions of an immunoassay commercialized for therapeutic drug monitoring of adalimumab (ADA) in rheumatoid arthritis (AR).Material and methods140 samples of patients with RA treated with ADA 40 mg every 14 days were analyzed by both versions of the test (V1 or previous and V2 or updated).ResultsA good correlation was obtained by both versions. In general V2 provides higher results of ADA's concentration than V1 and presents greater precision in the range of concentrations for clinical decisions, adjusting for the real concentration of the drug in blood. In addition, V2 allows for complete automation, which simplifies the analysis and reduces significantly the variability.ConclusionADA's monitoring with the updated version demonstrated to have technical significant advantages, constituting a more practical tool for therapeutic decisions in patients with RA.     

A General AUC-Type Measure and Biomarker Selection

Receiver operating characteristic (ROC) curve-based methods are well-accepted measures for describing and comparing the accuracy of diagnostic tests and biomarkers, which are essential in, for example, medical diagnoses and development of drugs and treatments. However, conventional ROC curve-based methods depend on the existence of a binary-scale gold standard and cannot be directly applied to a case with only a continuous gold standard and no binary references. One possible approach is to dichotomize such a continuous gold standard into a binary surrogate. However, to do so, we have to pay the price for the dubious dichotomization. To overcome this shortcoming, we propose a novel area under ROC curve-type measure, such that one can measure the association between biomarkers or diagnostic tests with the continuous gold standard directly, which extends the traditional area under the ROC curve and includes a measure reported in the literature as its special case. Moreover, it is well known that the diagnostic power of an individual marker can be improved through the combination of multiple potential markers. Hence, in this article, we also propose several algorithms to find the best linear combination of markers, with respect to this newly proposed measure. The asymptotic properties of both estimates of this new measure and of the best combination vector are studied. We then illustrate the performance of the proposed method using both synthesized and real datasets.     

Conical crowns with electroplated gold copings: retention force changes caused by wear and combined off‐axial load

Objectives: The aim of this study was to examine the wear behavior of conical crowns of gold alloy and zirconium dioxide ceramics facing electroplated gold copings. Methods: The conical crowns were milled in Group A of a cast gold alloy (Degunorm^®, DeguDent^®) and B zirconium dioxide (Cercon^®, DeguDent^®). Fifteen specimens were milled per group with a conicity of 2°. The electroplated coping was established by direct electroforming with the Solaris system (DeguDent^®) and glued into a framework. An apparatus accomplishing 5000 wear cycles performed the wear test. After each of the cycles, extra axial forces (80 N) were loaded 1 million times on an extension of the framework. The retentive forces and the correlating distance during insertion and separation were measured. The wear test was separated in a start phase, an initial wear phase and the long‐term wear period. The retention force value and the force–distance integral of the first 0.3 mm of each cycle were calculated. Results: The changes of retention force (ΔF) and integral (ΔF_d) differed significantly between both groups in the start phase (ΔF: A ?1.85 N, B +1.39 N, P=0.0028; ΔF_d: A ?0.155 N mm, B +0.2685 N mm, P=0.0378) and the initial wear phase. The long‐term wear period showed no differences in force and integral development. As a statistical test for the comparison of the median values of the two groups, the Mann–Whitney test was used. The median force never fell below 4 N or exceeded 12 N. Conclusions: Within the limitations of this study, the conical crowns tested showed clinically acceptable retentive properties. The values of about 4–6 N mentioned as sufficient in the recent literature were always attained. As the most retentive elements for dentures, both groups showed the main changes in retentive forces during the first 2000 cycles. The retention force development of the zirconia group appears to be less excursive over the whole wear test. To cite this article:
Bayer S, Zuziak W, Kraus D, Keilig L, Stark H, Enkling N. Conical crowns with electroplated gold copings: retention force changes caused by wear and combined off‐axial load.
Clin. Oral Impl. Res. 22 , 2011; 323–329.
doi: 10.1111/j.1600‐0501.2010.02003.x     

Expression of the C-terminal ORF2 protein of duck astrovirus for application in a serological test

Duck astrovirus (DAstV) is an important pathogen causing duck viral hepatitis (DVH), a highly contagious and fatal disease in young ducklings. To provide an antigen for a diagnostic serum test, the C-terminus of DAstV ORF2 protein was expressed in Escherichia coli. Four positive and 30 negative sera were used to validate the purified ORF2 protein by developing an indirect enzyme-linked immunosorbent assay (ELISA). No cross-reactions were found against other duck pathogens, including duck hepatitis A virus, duck plague herpesvirus, duck reovirus, Newcastle disease virus, and Riemerella anatipestifer 12/19 (63.2%) and 26/51 (51%) sera samples from two flocks of ducks that survived DAstV infections in commercial duck farms were positive for DAstV by this method, respectively. Interestingly, DAstV-specific antibodies were also detected in 12 (28.6%) of 42 sera samples from a different flock without DVH, indicating a wide distribution of subclinical infections caused by DAstV.     

A single amino acid substitution modulates low-pH-triggered membrane fusion of GP64 protein in Autographa californica and Bombyx mori nucleopolyhedroviruses

We have previously shown that budded viruses of Bombyx mori nucleopolyhedrovirus (BmNPV) enter the cell cytoplasm but do not migrate into the nuclei of non-permissive Sf9 cells that support a high titer of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) multiplication. Here we show, using the syncytium formation assay, that low-pH-triggered membrane fusion of BmNPV GP64 protein (Bm-GP64) is significantly lower than that of AcMNPV GP64 protein (Ac-GP64). Mutational analyses of GP64 proteins revealed that a single amino acid substitution between Ac-GP64 H155 and Bm-GP64 Y153 can have significant positive or negative effects on membrane fusion activity. Studies using bacmid-based GP64 recombinant AcMNPV harboring point-mutated ac-gp64 and bm-gp64 genes showed that Ac-GP64 H155Y and Bm-GP64 Y153H substitutions decreased and increased, respectively, the multiplication and cell-to-cell spread of progeny viruses. These results indicate that Ac-GP64 H155 facilitates the low-pH-triggered membrane fusion reaction between virus envelopes and endosomal membranes.     

Comparison among the BED capture enzyme immunoassay test and AxSYM avidity index assay for determining recent HIV infection and incidence in two Voluntary Counselling and Testing Centres in Northeast Brazil

The aims of this study were to compare the automated AxSYM avidity assay index with the BED capture enzyme immunoassay test and to calculate the HIV-1 incidence using the BED capture enzyme immunoassay and AxSYM avidity assay index algorithms within a population seeking the Voluntary Counselling and Testing Centres in two municipalities in the Metropolitan Region of Recife, Northeast of Brazil. An analysis was conducted in 365 samples that tested positive for HIV infection from frozen serum collected during the period 2006–2009. There was a similar proportion of males and females; most patients were heterosexual (86%) with a median age of 29 years. Of the 365 samples, 102 (28%) and 66 (18.1%) were identified as recent infections by BED capture enzyme immunoassay and AxSYM avidity assay index, respectively. The HIV-1 total incidence in the BED capture enzyme immunoassay and AxSYM avidity assay index algorithms were: 0.79 (95% CI: 0.60–0.98) and 0.34 (95% CI: −0.04 to 0.72), respectively. Incidence was higher among men. There was good agreement between the tests, with a kappa of 0.654 and a specificity of 95.8%. AxSYM avidity assay index may be helpful in improving the quality of the estimates of recent HIV infection and incidence, particularly when used in a combined algorithm with BED capture enzyme immunoassay.     

Assessment of biofilm removal capacity of a broad host range bacteriophage JHP against Pseudomonas aeruginosa

Pseudomonas aeruginosa is an efficient biofilm‐dwelling microbial pathogen, associated with nosocomial infections. These biofilm‐associated infections are resistant to antibiotics and immune defenses, therefore pose major problem against their treatment. This scenario demands alternative therapeutic regimens, and bacteriophage therapy is one among potential strategies for clinical management of multiple drug resistance. In this investigation, the efficacy of a bacteriophage, JHP, is evaluated to eradicate P. aeruginosa biofilms. Growth kinetics of P. aeruginosa biofilm revealed that the highest cell density biofilm (1.5 × 10¹⁶ CFU/mL) was established within the polystyrene microtiter plate at 72 h post inoculation. Pseudomonas aeruginosa biofilms of different ages, treated with JHP (0.6 MOI) for different post‐infection durations, reduced biomass from 2 to 4.5 logs (60–90%). JHP treatment before biofilm development reduced the bacterial load up to 9 logs (>95% bacterial load reduction) as compared with untreated control, which highlights its potential to prevent biofilm formation in indwelling medical devices. Combinations of JHP with other phages or antibiotics could be an efficient alternative for P. aeruginosa biofilm removal in clinical and industrial settings.     

Cytotoxic and mutagenic evaluation of extracts from plant species of the Miconia genus and their influence on doxorubicin-induced mutagenicity: An in vitro analysis

The Miconia genus, a plant widely used for medicine, occurs in tropical America and its extracts and isolated compounds have demonstrated antibiotic, antitumoral, analgesic and antimalarial activities. However, no study concerning its genotoxicity has been conducted and it is necessary to determine its potential mutagenic effects to develop products and chemicals from these extracts. This study assessed the cytotoxicity, mutagenicity and the protective effects of methanolic extracts from Miconia species on Chinese hamster lung fibroblast cell cultures (V79). The cytotoxicity was evaluated using a clonogenic assay. Cultures exposed to the extract of Miconia albicans up to a concentration of 30 μg/mL, M. cabucu up to 40 μg/mL, M. albicans up to 40 μg/mL and M. stenostachya up to 60 μg/mL exhibited a cytotoxic effect on the cells. The clonogenic assay used three non-cytotoxic concentrations (5, 10 and 20 μg/mL) to evaluate mutagenicity and antimutagenicity of the extracts. Cultures were treated with these three extract concentrations (mutagenicity test) or the extract associated with doxorubicin (DXR) (antimutagenicity test) in three protocols (pre-, simultaneous and post-treatments). Distilled water and DXR were used as negative and positive controls, respectively. In the micronucleus (MN) test, a significant reduction was observed in MN frequency in cultures treated with DXR and extracts compared to those receiving only DXR; a significant reduction was also observed for the presence of mutagenicity in all treatments. This study confirmed the safe use of Miconia extracts at the concentrations tested and reinforced the therapeutic properties previously described for Miconia species by showing their protective effects on doxorubicin-induced mutagenicity.