ABSTRACT A rapid, sensitive, precise and accurate liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for levo 3,4-dihydroxyphenylalanine (L-DOPA) determination in Vicia faba during different growth stages. The method applied a simple sample preparation step followed by a chromatographic separation on a Kinetex XB Core-Shell C18 (100 mm x 4.6 mm, 2.6 µm) column, using a mixture of ultrapure pure water (A) with 0.5 % (v/v) formic acid and methanol (B) as mobile phase. Analysis of L-DOPA was carried out by MS/MS applying a Multiple Reaction Monitoring (MRM) method using the transition m/z 198 → m/z 152. This LC-MS/MS method allowed a well-resolved detection of L-DOPA in ca. 2 min within 6 min run. Method was validated showing a linear range from 0.05 to 10 mg L-1 (R2 = 0.99); repeatability showed RSD value of 1.40%. Recoveries ranged from 94.14 to 116.62% with RSD values ≤ 5.66% and detection and quantification limits were 0.01 and 0.05 mg L-1, respectively. Applying this validated method, L-DOPA was determined in Vicia faba samples to determined its tissue distribution. As expected, a broad range of L-DOPA content finding the lowest content in seeds (4.72±2.12 mg g-1) and the highest in sprouts (133.60±5.65 mg g-1).

Um estudo epidemiológico de tipo descritivo retrospectivo foi realizado para determinar a taxa de infecção por Neisseria gonorrhoeae e seus fenótipos de resistência aos antimicrobianos em 666 pacientes adultos de ambos os sexos que compareceram no Serviço de ITS do Instituto Nacional de Epidemiología "Dr. Juan H. Jara, ANLIS "Dr. Carlos G. Malbrán" da cidade de Mar del Plata, entre os anos de 2005-2010. Para o diagnóstico de infecção por N. gonorrhoeae, as amostras foram obtidas por esfregaços endocervicais e esfregaços uretrais em homens e em seguida cultivadas. Os isolados foram encaminhados para o Laboratório Nacional de Referência em ITS para completar o estudo da sensibilidade antimicrobiana. Uma taxa de infecção de 12,2% em N. gonorrhoeae [IC 95%: 9,83-14,95] foi obtida. Os fenótipos de resistência mais prevalentes foram QRNG/CMRNG (resistência às quinolonas em conjunto com a resistência cromossômica à penicilina e tetraciclina), QRNG (resistência a quinolonas), PPNG (cepa produtora de penicilinase) e CMTR (resistência cromossômica à tetraciclina). Sob o controle epidemiológico das infecções produzidas por N. gonorrhoeae, o papel do laboratório é não só monitorar a incidência de casos na população, mas também o perfil de resistência aos antibióticos de uso terapêutico, visando a controlar a doença.

An epidemiological retrospective descriptive study was conducted in order to determine the rate of Neisseria gonorrhoeae infection and the antimicrobial resistance phenotypes in 666 adult patients of both sexes who attended the Sexually Transmitted Disease Service, at the National Institute of Epidemiology "Dr. Juan H. Jara"- ANLIS city of Mar del Plata, between the years 2005- 2010. For the diagnosis of N. gonorrhoeae infection, samples were obtained by endocervical swabs and urethral swabs in men. Microbiological growth on selective culture medium was identified using carbohydrate utilization. N. gonorrhoeae isolates were subsequently submitted to the National Reference Laboratory in STI for the study of antimicrobial susceptibility by determining the minimum inhibitory concentration. The N. gonorrhoeae infection rate was 12.2% [CI 95%: 9.83-14.95]. The most prevalent resistance phenotypes were QRNG/CMRNG (quinolone resistance in addition to chromosomal resistance to penicillin and tetracycline), QRNG (resistance to quinolone), PPNG (penicillinase producing strain) and CMTR (chromosomal resistance to tetracycline). As part of the epidemiological surveillance of infections by N. gonorrhoeae, the role of the laboratory is not only to monitor the incidence of cases in the population but also the antibiotic resistance profile for therapeutic use, in order to control the disease.

Se realizó un estudio epidemiológico de tipo descriptivo retrospectivo, para determinar la tasa de infección por Neisseria gonorrhoeae y sus fenotipos de resistencia a los antimicrobianos, en 666 pacientes adultos de ambos sexos que asistieron al servicio al Servicio de ITS del Instituto Nacional de Epidemiología "Dr. Juan H. Jara"- ANLIS "Dr. Carlos G. Malbrán", de la ciudad de Mar del Plata, entre los años 2005-2010. Para el diagnóstico de infección por N. gonorrhoeae, las muestras fueron obtenidas por hisopados endocervicales e hisopados uretrales a varones y luego cultivadas. Los aislamientos fueron remitidos al Laboratorio Nacional de Referencia en ITS para completar el estudio de sensibilidad antimicrobiana. Se obtuvo una tasa de infección por N. gonorrhoeae del 12,2% [IC 95%: 9,83-14,95]. Los fenotipos de resistencia más prevalentes resultaron QRNG/CMRNG (resistencia a quinolonas conjuntamente con resistencia cromosómica a penicilina y tetraciclina), QRNG (resistencia a quinolonas), PPNG (cepa productora de penicilinasa) y CMTR (resistencia cromosómica a tetraciclina). En el marco de la vigilancia epidemiológica de las infecciones producidas por N. gonorrhoeae, el rol del laboratorio consiste no sólo en monitorear la incidencia de casos en la población sino también el perfil de resistencia a los antibióticos de uso terapéutico, a fin de controlar la enfermedad.

A total of 115 unique clinical isolates of Neisseria gonorrhoeae and 54 strains of other genera and species included in the database of the NH card were tested by the Vitek 2C System (bioMérieux, Marcy L'Etoile, Francia). The gonoccocal isolates had been previously identified by conventional biochemical tests and by the latex agglutination test with monoclonal antibodies using the Phadebact Monoclonal GC Test (Bactus AB, Sweeden). The NH card correctly identified 111 (96.5 %) strains of 115 isolates; one strain was identified with low discriminatory power (0.86 %), one (0.86 %) was misidentified (as Neisseria meningitidis) whereas the other two (1.7 %) remained unidentified. The NH card for N. gonorrhoeae identification provided 100 % specificity. The results were available within 6 hours. The NH card could be considered a reliable and useful tool for routine use in Neisseria gonorrhoeae identification.

Por medio de la tarjeta NH del sistema Vitek 2C (bioMérieux, Marcy L'Etoile, Francia) se ensayó un total de 115 aislamientos clínicos únicos de Neisseria gonorrhoeae y 54 cepas de otros géneros y especies incluidas en la base de datos de esta tarjeta. Los aislamientos de gonococos fueron identificados previamente por medio de pruebas bioquímicas convencionales y por aglutinación con partículas de látex y anticuerpos monoclonales usando el Phadebact Monoclonal GC Test (Bactus AB, Suecia). La tarjeta NH identificó correctamente a 111 (96,5 %) de las cepas; una (0,86 %) cepa fue identificada con bajo poder de discriminación, una (0,86 %) fue identificada erróneamente como N. meningitidis y 2 (1,7 %) no fueron identificadas. La especificidad en la identificación de N. gonorrhoeae fue del 100 %. Los resultados fueron obtenidos dentro de las 6 horas. La tarjeta NH puede ser considerada como una herramienta útil y confiable para la identificación rutinaria de N. gonorrhoeae.

Zn-EDTA degradabilty by catechol-driven Fenton reaction was studied. Response surface methodology central composite design was employed to maximize this complex degradation. Theoretical speciation calculations were in good agreement with the experimental results. Fenton and Fenton type treatments are typically thought to be applicable only in the highly acidic range, representing a major operational constraint. Interestingly, at optimized concentrations, this CAT-driven Fenton reaction at pH 5.5 achieved 100% Zn-EDTA degradation; 60% COD and 17% TOC removals, using tiny amounts of CAT (50 µM), Fe(III) (445 µM) and H2O2 (20 mM) with no evident ferric sludge.

Ophiostoma fungi promote the occurrence of blue stain in coniferous wood, affecting the appearance wood products quality. Thus, different chemical products have been attempted to control them. Biological control of these sapstaining fungi, using albino strains of Ophiostoma looks like a successfully alternative to be applied. However, some Ophiostoma strains present a dimorphic behavior in liquid culture, which make them difficult to work with. Fungal dimorphism is defined as an environmentally and chemically controlled, reversible transformation of the yeast and mycelia morphologies. In this research, a two level factorial design was applied for evaluating the effect of four operative variables on albino strain PcF2A29 (Ophiostoma piceae (Münch) H. & P. Syd.) yeast-like growth a complex liquid medium. The results showed that inoculum size, temperature and their interaction had a statistically significant effect on yeast-like growth of albino strain PcF2A29. The most important effect was inoculum size. This factor explained 53% of the observed variability. The effect of inoculum size on yeast-like growth, phenomenon that is described in the O. piceae species by the first time with this paper, would be associated to quorum sensing activity.

Los hongos del género Ophiostoma promueven la ocurrencia de la mancha azul en madera de coníferas, afectando significativamente la calidad en los productos de apariencia. Para la prevención de la mancha azul se han empleado productos químicos de diferente naturaleza. El control biológico de la mancha azul con cepas albinas del género Ophiostoma aparece como una alternativa de promisorio potencial. Algunos de estos hongos cuando cultivados en medio líquido presentan un crecimiento dimórfico, con alta proporción de micelio, que dificulta su utilización. El dimorfismo, transformación reversible de las morfologías levadura y micelio, es controlado por factores químicos y del entorno. En esta investigación mediante la aplicación de un diseño factorial completo de dos niveles, se estudió el efecto de cuatro variables operacionales sobre el crecimiento levaduriforme de la cepa albina PcF2A29 de la especie Ophiostoma piceae (Münch) H. & P. Syd., creciendo en medio de cultivo líquido complejo. Los resultados mostraron que el tamaño del inóculo, la temperatura y la interacción tamaño del inóculo-temperatura tuvieron un efecto estadístico significativo sobre el crecimiento levaduriforme de la cepa albina PcF2A29de la especie O. piceae. De éstas variables, el tamaño del inóculo resultó ser el efecto más importante y explicó el 53% de la variabilidad observada. Estos resultados sugieren por primera vez, en la especie O. piceae, la existencia de un mecanismo de detección del quórum asociado a la variable tamaño del inóculo.

Tribromophenol (TBP) is a halogenated phenol mainly used as an intermediate of flame retardants in the electronics manufacturing industry as well as a fungicide in the wood industry to prevent fungal wood stain and decay. As a result of this massive use, its bio-availability, toxicity, and environmental fate are of increasing concern worldwide. TBP degradation by a catechol (CAT)-driven Fenton reaction was studied. In order to achieve the best yield in TBP degradation, an experimental design was applied for multivariate optimization of the experimental degrading system variables. At optimized concentrations, the CAT- driven Fenton reaction yielded 75% TBP degradation in 2 h at room temperature. The multivariate optimization showed that the highest TBP degradation (1 mol base) was obtained at a ratio of CAT: FeCl3: H2O2 = 0.150 : 0.211: 5.100 at pH = 3.4. A time course degradation of TBP comparing the CAT-driven Fenton reaction with the classical Fenton reaction is also presented. During the first hours of reaction (up to 8h), increased degradation efficiencies were observed in the CAT-driven Fenton reaction in comparison with the conventional Fenton reaction. Possible causes for the observed behavior are also discussed.

Degradation of EDTA in a Total Chlorine Free (TCF) cellulose pulp bleaching effluent, using UV and UV/H2O2 in presence and absence of iron, was studied. All experiences were conducted in an annular photolytic reactor at pH 9, 20°C, and 0.38 mM (110 mgL-1) EDTA concentration. EDTA degradation followed a first order apparent kinetics, with rate constant in the range of 0.02-0.72 min-1, depending on the initial hydrogen peroxide concentration and iron content. UV treatment without peroxide yielded 100 % degradation of Fe(III)-EDTA in 40 minutes of reaction, but low COD (8 %) and TOC (13 %) removal. Peroxide addition (3.3 mM)increased Fe(III)-EDTA degradation rates by UV treatment, resulting in 100% removal after 20 minutes, and greater COD (28 %) and TOC (36 %) reductions. In absence of iron, peroxide addition was required to obtain EDTA degradationyields above 50% after 1 h treatment. Results presented here show that UV/H2O2 treatment could be suitable as a preliminary stage before a biological treatment

The chelating agent EDTA (ethylenediaminetetraacetic acid) is a compound of massive use world wide with household and industrial applications, being one of the anthropogenic compounds with highest concentrations in inland European waters. In this review, the applications of EDTA and its behavior once it has been released into the environment are described. At a laboratory scale, degradation of EDTA has been achieved; however, in natural environments studies detect poor biodegradability. It is concluded that EDTA behaves as a persistent substance in the environment and that its contribution to heavy metals bioavailability and remobilization processes in the environment is a major concern.