Correlation Between Etest (R), Disk Diffusion, and Microdilution Methods for Antifungal Susceptibility Testing of Candida Species From Infection and Colonization

The correlation between the microdilution (MD), Etest (R) (ET), and disk diffusion (DD) methods was determined for amphotericin B, itraconazole and fluconazole. The minimal inhibitory concentration (MIC) of those antifungal agents was established for a total of 70 Candida spp. isolates from colonization and infection. The species distribution was: Candida albicans (n = 27), C. tropicalis (n = 17), C. glabrata (n = 16), C. parapsilosis (n = 8), and C. lusitaniae (n = 2). Non-Candida albicans Candida species showed higher MICs for the three antifungal agents when compared with C. albicans isolates. The overall concordance (based on the MIC value obtained within two dilutions) between the ET and the MD method was 83% for amphotericin B, 63% for itraconazole, and 64% for fluconazole. Considering the breakpoint, the agreement between the DD and MD methods was 71% for itraconazole and 67% for fluconazole. The DD zone diameters are highly reproducible and correlate well with the MD method, making agar-based methods a viable alternative to MD for susceptibility testing. However, data on agar-based tests for itraconazole and amphotericin B are yet scarce. Thus, further research must still be carded out to ensure the standardization to other antifungal agents. J. Clin. Lab. Anal. 23:324-330, 2009. (C) 2009 Wiley-Liss, Inc.

CEDIA (R) sirolimus assay compared with HPLC-MS/MS and HPLC-UV in transplant recipient specimens

The role of the therapeutic drug monitoring laboratory in support of immunosuppressant drug therapy is well established, and the introduction of sirolimus (SRL) is a new direction in this field. The lack of an immunoassay for several years has restricted the availability of SRL assay services. The recent availability of a CEDIA (R) SRL assay has the potential to improve this situation. The present communication has compared the CEDIA (R) SRL method with 2 established chromatographic methods, HPLC-UV and HPLC-MS/MS. The CEDIA (R) method, run on a Hitachi 917 analyzer, showed acceptable validation criteria with within-assay precision of 9.1% and 3.3%, and bias of 17.1% and 5.8%, at SRL concentrations of 5.0 mu g/L and 20 mu g/L, respectively. The corresponding between-run precision values were 11.5% and 3.3% and bias of 7.1% and 2.9% at 5.0 mu g/L and 20 mu g/L, respectively, The lower limit of quantification was found to be 3.0 mu g/L. A series of 96 EDTA whole-blood samples predominantly from renal transplant recipients were assayed by the 3 methods for comparison. It was found that the CEDIA (R) method showed a Deming regression line of CEDIA = 1.20 X HPLC-MS/MS - 0.07 (r = 0.934, SEE = 1.47), with a mean bias of 20.4%. Serial blood samples from 8 patients included in this evaluation showed that the CEDIA (R) method reflected the clinical fluctuations in the chromatographic methods, albeit with the variable bias noted. The CEDIA (R) method on the H917 analyzer is therefore a useful adjunct to SRL dosage individualization in renal transplant recipients.

Molecular identification and antifungal susceptibility profiles of Candida parapsilosis complex species isolated from culture collection of clinical samples

AbstractINTRODUCTION:Candida parapsilosis is a common yeast species found in cases of onychomycosis and candidemia associated with infected intravascular devices. In this study, we differentiated Candida parapsilosis sensu stricto, Candida orthopsilosis , and Candida metapsilosis from a culture collection containing blood and subungual scraping samples. Furthermore, we assessed the in vitro antifungal susceptibility of these species to fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin.METHODS:Differentiation of C. parapsilosis complex species was performed by amplification of the secondary alcohol dehydrogenase (SADH) gene and digestion by the restriction enzyme Ban I. All isolates were evaluated for the determination of minimal inhibitory concentrations using Etest, a method for antifungal susceptibility testing.RESULTS:Among the 87 isolates, 78 (89.7%) were identified as C. parapsilosis sensu stricto , five (5.7%) were identified as C. orthopsilosis , and four (4.6%) were identified as C. metapsilosis . Analysis of antifungal susceptibility showed that C. parapsilosis sensu strictoisolates were less susceptible to amphotericin B and itraconazole. One C. parapsilosis sensu stricto isolate was resistant to amphotericin B and itraconazole. Moreover, 10.2% of C. parapsilosis sensu stricto isolates were resistant to caspofungin. Two C. parapsilosis sensu strictoisolates and one C. metapsilosis isolate were susceptible to fluconazole in a dose-dependent manner.CONCLUSIONS:We reported the first molecular identification of C. parapsilosiscomplex species in State of Goiás, Brazil. Additionally, we showed that although the three species exhibited differences in antifungal susceptibility profiles, the primary susceptibility of this species was to caspofungin.

Medida da aliança parental: validação portuguesa e construção de uma versão reduzida

Objetivo: A Medida de Aliança Parental (PAM) avalia a qualidade da relação interparental na prestação de cuidados da criança. O presente artigo apresenta a validação de uma versão portuguesa da medida, bem como examina as qualidades psicométricas de uma versão reduzida com 6 itens do instrumento (PAM-R). Método: A amostra foi constituída por 182 pais (63% mães), dos quais 72 preencheram um instrumento de avaliação dos problemas de ajustamento psicológico das crianças. Resultados: As análises fatoriais confirmatórias não corroboraram a estrutura dos dois modelos testados. No entanto, excelentes valores foram encontrados nos índices de adequação do modelo da PAM-R. Não foram encontrados erros de especificação no modelo unidimensional testado, o que suporta a validade fatorial da versão reduzida da PAM. A PAM-R apresentou excelentes valores de consistência interna e uma correlação negativa e significativa com a medida de problemas de ajustamento das crianças. Conclusões: PAM-R emerge como uma medida que possibilita a avaliação do impacto das dimensões familiares no funcionamento e desenvolvimento psicológico das crianças, em contextos de prestação de cuidados de saúde primários.

A escolha da faixa espectral no uso combinado de métodos espectroscópicos e quimiométricos

A method is presented for the choice of spectral regions when absorption measurements are coupled to chemometric tools to perform quantitative analyses. The method is based on the spectral distribution of the relative standard deviation of concentration (s c/c). It has been applied to the development of PLS-FTNIR calibration models for the determination of density and MON of gasoline, and ethanol content and density of ethanol fuel. The new method was also compared with the correlation (R²) method and has proved to generate PLS calibration models that present better accuracy and precision than those based on R².

An investigation of pile diameter influence in the bearing capacity on Dynamic Load Test (DLT)

During the construction of five residential buildings in the city of Taubate, State of São Paulo, it was possible to carry out one comprehensive investigation of the behavior of precast concrete piles in clay shales. This paper describes the results of Dynamic Load Tests (DLT's) executed in three piles with different diameters and with the same embedded length. The tests were monitored using the PDA(R) (Pile Driving Analyzer) and the pile top displacement was measured by pencil and paper procedure. From the curves of RMX versus DMX resulted from CASE(R) method, CAPWAPC(R) analyses were made for signals where the maximum mobilized soil resistance was verified. The results were compared with the predicted bearing capacity using the semi-empirical method of Decourt & Quaresma (1978) and Decourt (1982) based on SPT values and the description of the soil profile. Some comments related to the values of quake and damping used for clay shales in the analyses are also presented.

Psychometric properties of the Spanish adaptation of the School Attitude Assessment Survey-Revised

Background: The assessment of attitudes toward school with the objective of identifying adolescents who may be at risk of underachievement has become an important area of research in educational psychology, although few specific tools for their evaluation have been designed to date. One of the instruments available is the School Attitude Assessment Survey-Revised (SAAS-R). Method: The objective of the current research is to test the construct validity and to analyze the psychometric properties of the Spanish version of the SAAS-R. Data were collected from 1,398 students attending different high schools. Students completed the SAAS-R along with measures of the g factor, and academic achievement was obtained from school records. Results: Confirmatory factor analysis, multivariate analysis of variance and analysis of variance tests supported the validity evidence. Conclusions: The results indicate that the Spanish version of the SAAS-R is a useful measure that contributes to identification of underachieving students. Lastly, the results obtained and their implications for education are discussed.

Evaluating productive efficiency:comparative study of commercial banks in Gulf countries

Financial institutes are an integral part of any modern economy. In the 1970s and 1980s, Gulf Cooperation Council (GCC) countries made significant progress in financial deepening and in building a modern financial infrastructure. This study aims to evaluate the performance (efficiency) of financial institutes (banking sector) in GCC countries. Since, the selected variables include negative data for some banks and positive for others, and the available evaluation methods are not helpful in this case, so we developed a Semi Oriented Radial Model to perform this evaluation. Furthermore, since the SORM evaluation result provides a limited information for any decision maker (bankers, investors, etc...), we proposed a second stage analysis using classification and regression (C&R) method to get further results combining SORM results with other environmental data (Financial, economical and political) to set rules for the efficient banks, hence, the results will be useful for bankers in order to improve their bank performance and to the investors, maximize their returns. Mainly there are two approaches to evaluate the performance of Decision Making Units (DMUs), under each of them there are different methods with different assumptions. Parametric approach is based on the econometric regression theory and nonparametric approach is based on a mathematical linear programming theory. Under the nonparametric approaches, there are two methods: Data Envelopment Analysis (DEA) and Free Disposal Hull (FDH). While there are three methods under the parametric approach: Stochastic Frontier Analysis (SFA); Thick Frontier Analysis (TFA) and Distribution-Free Analysis (DFA). The result shows that DEA and SFA are the most applicable methods in banking sector, but DEA is seem to be most popular between researchers. However DEA as SFA still facing many challenges, one of these challenges is how to deal with negative data, since it requires the assumption that all the input and output values are non-negative, while in many applications negative outputs could appear e.g. losses in contrast with profit. Although there are few developed Models under DEA to deal with negative data but we believe that each of them has it is own limitations, therefore we developed a Semi-Oriented-Radial-Model (SORM) that could handle the negativity issue in DEA. The application result using SORM shows that the overall performance of GCC banking is relatively high (85.6%). Although, the efficiency score is fluctuated over the study period (1998-2007) due to the second Gulf War and to the international financial crisis, but still higher than the efficiency score of their counterpart in other countries. Banks operating in Saudi Arabia seem to be the highest efficient banks followed by UAE, Omani and Bahraini banks, while banks operating in Qatar and Kuwait seem to be the lowest efficient banks; this is because these two countries are the most affected country in the second Gulf War. Also, the result shows that there is no statistical relationship between the operating style (Islamic or Conventional) and bank efficiency. Even though there is no statistical differences due to the operational style, but Islamic bank seem to be more efficient than the Conventional bank, since on average their efficiency score is 86.33% compare to 85.38% for Conventional banks. Furthermore, the Islamic banks seem to be more affected by the political crisis (second Gulf War), whereas Conventional banks seem to be more affected by the financial crisis.

The synthesis and properties of some hydrazines

A new synthetic method, applicable to the preparation of a wide range of hydrazine derivatives, is described. This involves the diborane reduction of a hydrazone, or, more conveniently, the reductive-condensation of a hydrazine and the appropriate aldehyde (or ketone). The method gives high yields and provides a particularly simple route to the relatively inaccessible 1,2-disubstituted hydrazines bearing a different group on each nitrogen. The new method has also been applied to the preparation of 1,2-disubstituted hydrazines with the same group on both nitrogens (via the azine), the very rare 1 ,2-disubstituted hydrazines bearing a tert-butyl group, trisubstituted hydrazines and monosubstituted hydrazines. Application of the reaction to the preparation of diaziridines has also been investigated. A mechanism for the reduction, supported by the isolation of a boron-containing intermediate, is suggested. Some limitations of the procedure are discussed. A general i.r. method of distinguishing the isomeric disubstituted hydrazines, as stable salts, has been developed. This has the advantages of speed and simplicity over previous methods. The mass spectra of a series of monosubstituted hydrazines, a series of 1,2-disubstituted hydrazines and some 1-benzoyl 2-alkylhydrazines have been examined in detail. The spectra are generally dominated byα -cleavage processes and the compounds show a variety of interesting rearrangement reactions. The mass spectra of some 1, 1-disubstituted hydrazines and some trisubstituted hydrazines have also been examined. Rearrangement processes occurring in the mass spectrum of tropylium fluoroborate have been examined. Similar rearrangements have been found in the spectrum of trityl fluoroborate and may be of general occurrence in the mass spectra of aromatic fluoroborates. Chemical shift values for some groups on hydrazine nitrogen are recorded and the results of tumour inhibitory tests on some hydrazines are also given.

Evaluation of Etest and macrodilution broth method for antifungal susceptibility testing of Candida sp strains isolated from oral cavities of AIDS patients

A comparison of the Etest and the reference broth macrodilution susceptibility test for fluconazole, ketoconazole, itraconazole and amphotericin B was performed with 59 of Candida species isolated from the oral cavities of AIDS patients. The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines. Our data showed that there was a good correlation between the MICs obtained by the Etest and broth dilution methods. When only the MIC results at ± 2 dilutions for both methods were considered, the agreement rates were 90.4% for itraconazole, ketoconazole and amphotericin B and 84.6% for fluconazole of the C. albicans tested. In contrast, to the reference method, the Etest method classified as susceptible three fluconazole-resistant isolates and one itraconazole-resistant isolate, representing four very major errors. These results indicate that Etest could be considered useful for antifungal sensitivity evaluation of yeasts in clinical laboratories.

R-matrices and the tensor product graph method

A systematic method for constructing trigonometric R-matrices corresponding to the (multiplicity-free) tensor product of any two affinizable representations of a quantum algebra or superalgebra has been developed by the Brisbane group and its collaborators. This method has been referred to as the Tensor Product Graph Method. Here we describe applications of this method to untwisted and twisted quantum affine superalgebras.

Validation and long-term evaluation of a modified on-line chiral analytical method for therapeutic drug monitoring of (R,S)-methadone in clinical samples.

Matrix effects, which represent an important issue in liquid chromatography coupled to mass spectrometry or tandem mass spectrometry detection, should be closely assessed during method development. In the case of quantitative analysis, the use of stable isotope-labelled internal standard with physico-chemical properties and ionization behaviour similar to the analyte is recommended. In this paper, an example of the choice of a co-eluting deuterated internal standard to compensate for short-term and long-term matrix effect in the case of chiral (R,S)-methadone plasma quantification is reported. The method was fully validated over a concentration range of 5-800 ng/mL for each methadone enantiomer with satisfactory relative bias (-1.0 to 1.0%), repeatability (0.9-4.9%) and intermediate precision (1.4-12.0%). From the results obtained during validation, a control chart process during 52 series of routine analysis was established using both intermediate precision standard deviation and FDA acceptance criteria. The results of routine quality control samples were generally included in the +/-15% variability around the target value and mainly in the two standard deviation interval illustrating the long-term stability of the method. The intermediate precision variability estimated in method validation was found to be coherent with the routine use of the method. During this period, 257 trough concentration and 54 peak concentration plasma samples of patients undergoing (R,S)-methadone treatment were successfully analysed for routine therapeutic drug monitoring.

An Investigation of the Chemical Method of Determining the Cement Content of Hardened Concrete, MLR-71-01 and R-248, 1971

The Iowa State Highway Commission Laboratory is called upon to determine the cement content of hardened concrete when field problems relating to batch weights are encountered. The standard test for determining the cement content is ASTM C-85. An investigation of this method by the New Jersey State Highway Department involving duplicate samples and four cooperating laboratories produced very erratic results, however, the results obtained by this method have not been directly compared to known cement contents of concrete made with various cements and various aggregates used in Iowa.

A Laboratory Investigation of An Accelerated Polishing Method for Determining the Skid Resistance Potential of Aggregates, MLR-76-02 and R-264, 1976

An initial feasibility study indicated that the "Purdue Accelerated Polishing Method" gave repeatable results when testing the skid resistance of laboratory specimens. The results also showed a rough correlation with the field performance of the same aggregate sources. The research was then expanded to include all available asphalt aggregates. The results of the expanded study indicated that the method is not presently capable of developing and measuring the full skid potential of the various aggregate sources. Further research in the area of polishing times and/or pressures is needed.

Substitution-Newton-Raphson method applied to the modeling of a vapour compression refrigeration system using different representations of the thermodynamic properties of R-134a

This paper gives a detailed presentation of the Substitution-Newton-Raphson method, suitable for large sparse non-linear systems. It combines the Successive Substitution method and the Newton-Raphson method in such way as to take the best advantages of both, keeping the convergence features of the Newton-Raphson with the low requirements of memory and time of the Successive Substitution schemes. The large system is solved employing few effective variables, using the greatest possible part of the model equations in substitution fashion to fix the remaining variables, but maintaining the convergence characteristics of the Newton-Raphson. The methodology is exemplified through a simple algebraic system, and applied to a simple thermodynamic, mechanical and heat transfer modeling of a single-stage vapor compression refrigeration system. Three distinct approaches for reproducing the thermodynamic properties of the refrigerant R-134a are compared: the linear interpolation from tabulated data, the use of polynomial fitted curves and the use of functions derived from the Helmholtz free energy.