Caracterización colorimétrica del proceso termogravimétrico de la deshidroxilación de caolín hidrotermal y de toba / Colorimetric characterization of thermogravimetric process for dehydroxilation of hydrothermal and tuff kaolins

El metacaolín es el producto obtenido de la calcinación del caolín. La alta actividad puzolánica del metacaolín permite su utilización como un material sustituto del cemento en el concreto. Esta y otras propiedades fisicoquímicas se ven afectadas por las condiciones de procesamiento del caolín. Por lo tanto, este estudio tuvo como objetivo caracterizar los cambios del color y densidad de dos tipos de caolín (toba triturada e hidrotermal) por medio de un análisis termogravimétrico del proceso de calcinación. Para la evaluación de la densidad se empleó la norma ASTM C188, mientras que la valoración de los cambios de color utilizó un espectrofotómetro C I E - L* a * b* en conjunto con la norma UNE 80117. Asimismo, la pérdida de peso y la densidad se correlacionaron con las coordenadas de color mediante una regresión polinomial. Los resultados demostraron que la deshidroxi-lación de los caolines ocurrió entre 400 ºC y 650 ºC, caracterizándose por un máximo en el delta E* de 12.9 y 4.3 para el caolín hidrotermal y de toba, respectivamente. Además, el caolín de toba triturada presentó la máxima luminosidad (L* = 92.84) de todos los tratamientos a los 21 ºC. Este valor disminuyó 11.75% al incrementar la temperatura hasta 450 ºC. A partir de esta temperatura,L* incrementó linealmente hasta alcanzar un valor final de 87.3 a 900 ºC. La regresión polinomial obtenida explica en un 93% y 92% la variación del peso en función de los parámetros C I E - L* a * b* para el caolín de toba triturada e hidrotermal, respectivamente.

Metakaolin is a product of kaolin's calcination. The high pozzolanic activity of metakaolin allows its usage as supplementary cementitious material in concrete. This property and other physicochemical properties are affected by metakaolin's manufacturing conditions. Therefore, this study aims to characterize the changes in color and density of two types of kaolin (tuff and hydrothermal) through a thermogravimetric analysis of the calcina-tion process. Evaluation of density used ASTM C188, while the assessment of color changes used a CIE-L*a*b* spectrophotometer in conjunction with normative UNE 80117. In addition, weight loss and density were correlated with the color coordinates using polynomial regression. The results showed that kaolin dehydroxylation occurred at 450ºC and 650ºC, characterized by a maximum in delta E * of 12.9 and 4.3 for hydrothermal and tuff kaolin, respectively. In addition, the tuff kaolin presented the maximum luminosity (L * = 92.84) of all the treatments at 21ºC. This value decreased 11.75% during the temperature increment up to 450ºC. From this temperature, L * increased linearly until reaching a final value of 87.3 at 900ºC. The polynomial regression explained 93% and 92% of the weight variation as a function of the CIE-L*a*b* parameters for tuff and hydrothermal kaolin, respectively.

Estruturação de emulsão tipo maionese com característica funcional e produzida com derivado proteico / Mayonnaise emulsion with functional characteristic and produced with protein derivative

O soro de leite é considerado um subproduto das indústrias de laticínios, uma parte de sua produção é destinada como matéria-prima de produtos alimentícios, mas parte é direcionada para alimentação animal. Objetivou-se com o presente estudo elaborar formulas de emulsões do tipo maionese utilizando ingrediente proteico o soro de leite em pó, leite desnatado em pó e a mistura entre soro e leite, ambos em pó, bem como investigar a influência destes ingredientes na textura, reologia, análise térmica, índice de estabilidade, análise colorimétrica e a vida útil das formulações. Justifica-se a utilização de soro de leite devido a seu menor preço de mercado do que ovos em pó ou líquido pasteurizado normalmente utilizados, evidenciando a necessidade de dar espaço a matérias-primas consideradas como subprodutos dentro da indústria. Os produtos emulsionados foram formulados com mistura de óleo, água, soro de leite em pó, leite desnatado em pó, alho e mostarda em pó, contendo aproximadamente 70% de gordura, com variação no teor proteico. Foram estabelecidas três formulações cada uma com um tipo ou mistura de emulsificantes. As análises efetuadas no desenvolvimento do trabalho foram textura, reologia, atividade de água, pH, colorimetria, análise térmica, índice de estabilidade da emulsão e cálculo de proteínas e lipídeos das formulações. Foi possível verificar que tanto o soro de leite em pó como o leite desnatado em pó apresentaram características de agente emulsificante.A formulação F1 (soro de leite em pó) não atingiram os padrões estruturais de maioneses comerciais, todavia os resultados obtidos pela formulação F2 (leite desnatado em pó) atingiram padrões equivalentes a produtos comercializados, bem como a formulação F3 (soro de leite em pó + leite desnatado em pó) com padrão das maioneses light em textura e reologia. Os resultados das análises de atividade de água apresentaram pequenas variações (0,934-0,941) ao longo dos 30 dias de avaliação. Os conservantes em pó (alho e mostarda) favoreceram a coloração das formulações, pH na faixa da neutralidade, assegurando aos produtos vida útil de 30 dias em temperatura de refrigeração. É possível utilizar osoro de leite e leite em pó como agente emulsificante para emulsões do tipo maionese, bem como alho e mostarda em pó como ingredientes que aumentem a maior vida útil desses produtos

Whey is considered a by-product of the dairy industry, part of its production is used as raw material for food products, but part is used for animal feed. The objective of this study was to prepare mayonnaise emulsion formulas using protein whey powder, skimmed milk powder and the mixture between whey and milk, both in powder, as well as investigating the influence of these ingredients on texture, rheology, thermal analysis, stability index, colorimetric analysis and the useful life of the formulations. The use of whey is justified due to its lower market price than powdered eggs or pasteurized liquid normally used, highlighting the need to make room for raw materials considered as by-products within the industry. The emulsified products were formulated with a mixture of oil, water, whey powder, skimmed milk powder, garlic and mustard powder, containing approximately 70% fat, with variation in protein content. Three formulations were established each with a type or mixture of emulsifiers. The analyzes carried out in the development of the work were texture, rheology, water activity, pH, colorimetry, thermal analysis, emulsion stability index and calculation of proteins and lipids in the formulations. It was possible to verify that both whey powder and skimmed milk powder showed characteristics of emulsifying agent. Formulation F1 (whey powder) did not reach the structural standards of commercial mayonnaise, however the results obtained by formulation F2 (skimmed milk powder) reached standards equivalent to commercialized products, as well as the formulation F3 (whey powder + skimmed milk powder) with light mayonnaise pattern in texture and rheology. The results of the water activity analysis showed slight variations (0.934-0.941) over the 30 days of evaluation. The preservatives in powder (garlic and mustard) favored the color of the formulations, pH in the neutrality range, ensuring the products' useful life of 30 days in refrigeration temperature. It is possible to use whey and powdered milk as an emulsifying agent for emulsions of the mayonnaise type, as well as garlic and mustard powder as ingredients that increase the longer useful life of these products

Análise da presença de formol e avaliação do ph de alisantes capilares / Analysis of presence of formol and ph assessment in hair straighteners

O processo de alisamento capilar é uma prática comum realizada nos salões de beleza. O procedimento exige a utilização de substâncias com capacidade de rompimento das cadeias dissulfídricas da fibra capilar com posterior modelamento para o efeito desejado, sendo o formol um dos compostos mais utilizados para esta finalidade, porém indevidamente. De acordo com a legislação vigente, o formol só pode ser utilizado em produtos cosméticos com a função de conservante em uma concentração máxima de 0,2%. Devido a seu uso incorreto em produtos capilares o presente trabalho teve como objetivo realizar uma análise semi-quantitativa da presença de formol em amostras de alisantes capilares, bem como verificar o pH destes produtos. Foram obtidas 22 amostras de alisantes capilares doadas por salões de beleza da região de Umuarama - PR. A determinação da presença de formol foi realizada através da reação de Shiff e comparação com escala colorimétrica de concentrações padronizadas de formaldeído variando de 0,005% a 10%. A verificação do pH foi realizada através da preparação de soluções aquosas de 10% do alisante e posterior aferição em pHmetro digital. Das amostras analisadas, verificou-se 22,72% encontraram-se em conformidade, apresentando quantidade de formaldeído adequada com a legislação (até 0,2%) ou ausência do composto, enquanto que 77,28% apresentaram valores acima do permitido. Já o pH adequado foi constatado em apenas 13,64% amostras. O uso incorreto ou exagerado do formol pode acarretar danos à saúde, como cefaléia, dispnéia, queimadura, edema pulmonar e até câncer. Uma maior fiscalização deve ser realizada nos estabelecimentos que realizam procedimentos de alisamento capilar, bem como nas indústrias produtoras e ainda em importadoras, para uma melhor garantia do cumprimento da legislação tanto para a preservação da saúde dos profissionais quando dos usuários.

The hair-straightening process is a common practice in most beauty salons. The procedure requires the use of substances capable of disrupting the disulfide chains of the hair fiber with subsequent modeling for the desired effect, with formaldehyde being one of the most commonly but improperly used compounds for this purpose. According to the current legislation, formaldehyde can only be used in cosmetic products as a preservative function in a maximum concentration of 0.2%. Due to its incorrect use in capillary products, this work has the purpose of developing a semi-quantitative analysis of the presence of formaldehyde in samples of hair straighteners, as well as verifying the pH of those products. Twenty-two samples of hair straighteners were donated by beauty salons from the region of Umuarama-PR. The determination of the presence of formaldehyde was performed using the Shiff reaction and compared using the colorimetric scale for standard formaldehyde concentrations varying from 0.005% to 10%. The pH verification was carried out by the preparation of 10% aqueous solutions of the straightener and subsequent measurement in a digital pH meter. From the analyzed samples, 22.72% were found to be in compliance, presenting the amount of formaldehyde within the legislation (up to 0.2%) or absence of the compound, while 77.28% presenting values above the legal limitations. Additionally, adequate pH was verified in only 13.64% of the samples. Incorrect or exaggerated use of formaldehyde can lead to health issues, such as headache, dyspnea, burns, pulmonary edema and even cancer. Greater surveillance should be carried out in establishments that perform hair straightening procedures as well as in the producing and importing industries in order to guarantee better compliance with the legislation both for the preservation of the health of professionals and users alike.

Biological roles of filamin a in prostate cancer cells

ABSTRACT Objective This study aims to investigate the association of filamin A with the function and morphology of prostate cancer (PCa) cells, and explore the role of filamin A in the development of PCa, in order to analyze its significance in the evolvement of PCa. Materials and Methods A stably transfected cell line, in which filamin A expression was suppressed by RNA interference, was first established. Then, the effects of the suppression of filamin A gene expression on the biological characteristics of human PCa LNCaP cells were observed through cell morphology, in vitro cell growth curve, soft agar cloning assay, and scratch test. Results A cell line model with a low expression of filamin A was successfully constructed on the basis of LNCaP cells. The morphology of cells transfected with plasmid pSilencer-filamin A was the following: Cells were loosely arranged, had less connection with each other, had fewer tentacles, and presented a fibrous look. The growth rate of LNCap cells was faster than cells transfected with plasmid pSilencer-filamin A (P <0.05). The clones of LNCap cells in the soft agar cloning assay was significantly fewer than that of cells stably transfected with plasmid pSilencer-filamin A (P <0.05). Cells stably transfected with plasmid pSilencer-filamin A presented with a stronger healing and migration ability compared to LNCap cells (healing rate was 32.2% and 12.1%, respectively; P <0.05). Conclusion The expression of the filamin A gene inhibited the malignant development of LNCap cells. Therefore, the filamin A gene may be a tumor suppressor gene.

Comparação dos colorímetros Nix Color Sensor Pro e MINOLTA CM-5 na avaliação da cor da carne bovina descongelada e maturada / Comparison of Nix Color Sensor Pro and MINOLTA CM-5 colorimeters in the evaluation of thawed and aged beef color

O objetivo deste trabalho foi comparar a capacidade dos colorímetros Nix Color Sensor Pro (NIX) e CM-5 (MINOLTA) para detectar a variação de cor em amostras de carne bovina submetidas a diferentes taxas de congelamento (lento x rápido) e diferentes tempos de maturação (0 e 14 dias). Todos os índices de cor mensurados foram maiores (P<0,05) no colorímetro MINOLTA do que no colorímetro NIX, que registra a cor das amostras cárneas como sendo mais escuras, com menor intensidade e com tonalidade menos vermelha. A variação nos índices de cor medida pelos aparelhos não foi compatível, indicando efeitos diferentes pelos tratamentos avaliados. Conclui-se que o NIX não pode ser considerado comparável ao MINOLTA ao medir a cor da carne bovina.

Uso de la tarjeta colorimétrica visual para la detección oportuna de atresia de vías biliares / Colorimetric card use for early detection visual biliary atresia

Resumen: Introducción: La atresia de vías biliares (AVB) es una condición que provoca obstrucción al flujo biliar, y de no corregirse quirúrgicamente, provoca cirrosis y la muerte antes de los 2 años de edad. En México, a partir del año 2013 se incorporó la tarjeta colorimétrica visual (TCV) para la detección oportuna de la AVB a la Cartilla Nacional de Salud (CNS). El objetivo de este estudio fue evaluar el impacto de la TCV para la detección de AVB antes y después de su incorporación a la CNS. Métodos: Estudio ambispectivo, observacional y analítico. Se incluyeron pacientes con AVB atendidos en dos hospitales pediátricos de tercer nivel de atención. Se compararon la edad de referencia, el diagnóstico y la cirugía antes y después de la incorporación de la TCV. Además, se realizó un cuestionario a los padres para conocer su percepción sobre la TCV. Resultados: En 59 niños no hubo diferencias en la edad al diagnóstico (75 vs 70 días) ni en la edad al momento de la cirugía (84 vs 90 días) entre antes y después de la implementación de la TCV. Solo el 30% de los padres recibieron información del uso de la TCV y solo el 38% identificaron las evacuaciones anormales. Conclusiones: Este estudio no mostró cambios en el tiempo para la detección oportuna de AVB mediante el uso de la TCV. Por lo tanto, es necesario reforzar el programa en los tres niveles de atención en nuestro país.

Abstract: Background: Bile duct atresia (BVA) is a condition that causes obstruction to biliary flow, not corrected surgically, causes cirrhosis and death before 2 years of age. In Mexico from 2013 the visual colorimetric card (VVC) was incorporated for the timely detection of BVA to the National Health Card (NHC). The aim of this study was to evaluate the impact of VCT for the detection of BVA before and after the use of NHC incorporation. Methods: Ambispective, analytical observational study. We included patients with AVB treated in two pediatric hospitals of third level care. We compared the age of reference, diagnosis and surgery before and after incorporation of the TCV. In addition, a questionnaire was made to the parents to know their perception about the TCV. Results: In 59 children, there were no differences in age at diagnosis (75 vs 70 days) and age at surgery (84 vs 90 days) between the pre and post-implementation period of the VVC. The questionnaire showed that 10 (30%) of the parents received information about the use of the VVC and 13 (38%) identified the abnormal evacuations. Conclusions: This study did not show changes in time for the timely detection of BVA by using VVC. Therefore, it is necessary to reinforce the program in the three levels of care in our country.

Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability

Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm) from polyamide (Valplast) and PMMA (Vertex Rapid Simplified) denture base materials were made. Eight specimens from each material were immersed in distilled water (control) and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE*) and translucency parameter (TP) were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p<0.05) and a significant interaction of cycle-material (p<0.001). The ΔΕ* parameter was significantly higher with a higher number of cycles (p<0.001), but it did not vary between materials (p>0.05). TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001). Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.

Screening of melon genotypes for resistance to vegetable leafminer and your phenotypic correlations with colorimetry

ABSTRACT Melon is one of the most important vegetable crops in the world. With short cycle in a system of phased planting, phytosanitary control is compromised, and a great volume of agricultural chemicals is used to control vegetable leafminer. Genetic control is an ideal alternative to avoid the damage caused by this insect. Thus, the aim of this study was to evaluate Cucumis accessions in regard to resistance to leafminer and correlate the variables analyzed. Fifty-four accessions and four commercial hybrids of melon were tested. The study was divided into two experiments: with and with no choice. The following characteristics were evaluated: with choice, in field - subjective score based on the infestation and the number of mines per leaf; and with no choice, in cage - number of mines per leaf, chlorophyll content, and leaf colorimetry. The results showed variability among the accessions and some genotypes showed favorable results for resistance in both experiments. There was correlation between the two variables in the experiment in the field. The accessions CNPH 11-282, CNPH 06-1047, and CNPH 11-1077 are the most recommended for future breeding programs with aim on introgression of resistance to vegetable leafminer in melon.

Peptídeos peptidomiméticos da película adquirida do esmalte: efeitos no crescimento de cristal de hidroxiapatita / Peptidomimetics of acquired enamel pellicle peptides: effects on hydroxyapatite crystal growth

Os peptídeos da estaterina (DR9) e da histatina 3 (RR14), que ocorrem naturalmente na película in vivo, amplificam o efeito inibitório do crescimento de cristais de hidroxiapatita, função relacionada à remineralizarão do esmalte e formação de cálculos dentários. A hipótese da duplicação/hibridação de domínios funcionais dos peptídeos DR9 da estaterina e RR14 da histatina 3 foi testada. Para isto, os peptídeos peptidomiméticos (DR9-DR9, DR9-RR14), além deles individualmente e suas proteínas intactas (DR9, RR14, estaterina e histatina 3) foram estudados em sete concentrações diferentes para avaliar o efeito da inibição do crescimento de cristais de hidroxiapatita. Foi utilizado um ensaio colorimétrico de microplaca para quantificar o crescimento de cristais de hidroxiapatita. As experiências foram feitas em triplicata e a concentração inibitória (IC50) foi estabelecida para cada grupo. A IC50 foi calculada para todos os peptídeos e proteínas testados. A histatina 3 e o RR14 não atingiram o valor de IC50. O DR9- RR14 atingiu o valor de IC50 a 3,80 M. Como esperado, DR9 e DR9-DR9 demonstraram um efeito inibitório significativo na atividade de crescimento de cristais, atingindo o valor de IC50 a 2,82 M e 1,07 M, respectivamente. A estaterina atingiu o valor de IC50 a 2,50 M. Na análise estatística, foram aplicados os testes ANOVA e Student-Newman-Keuls para comparações por pares, para comparar os valores entre os grupos. O DR9-DR9 amplificou o efeito inibitório do crescimento de cristais de hidroxiapatita quando comparado com DR9 único (p <0,05), demonstrando que a multiplicação do domínio funcional é uma forte tendência evolutiva da proteína. De forma interessante, o peptídeo híbrido DR9-RR14 demonstrou um efeito inibitório intermediário quando comparado com outros dois grupos: DR9 único e DR9-DR9. Este estudo utilizou a abordagem peptidomimética para investigar uma via potencial de evolução da proteína relacionada com a duplicação/hibridação dos constituintes peptídicos naturais da película adquirida de esmalte. O conhecimento obtido por meio dos resultados deste trabalho pode fornecer uma base para o desenvolvimento de peptídeos sintéticos para uso terapêutico, tanto contra cárie dentária, como para a doença periodontal.(AU)

The statherin and histatin 3 peptides (DR9 and RR14 respectively), which occur naturally in the film in vivo, amplify the inhibitory effect for the growth of hydroxyapatite crystals, a function related to remineralization of the enamel and formation of dental calculi. The hypothesis of duplication/hybridization of functional domains of the DR9 peptides of the statherin and RR14 of histatin 3 was tested. For this, the peptidomimetic peptides (DR9-DR9, DR9-RR14), in addition to them individually and their intact proteins (DR9, RR14, statherin and histatin 3) were studied at seven different concentrations to evaluate the effect of growth inhibition of hydroxyapatite crystals. A colorimetric assay of microplate was used to quantify the growth of hydroxyapatite crystals. The experiments were done in triplicate and the inhibitory concentration (IC50) was established for each group. The IC50 was calculated for all peptides and proteins tested. Histatin 3 and RR14 did not reach the IC50 value. DR9-RR14 reached the IC50 value at 3.80 M. As expected, DR9 and DR9-DR9 demonstrated a significant inhibitory effect on crystal growth activity, reaching the IC50 value at 2.82 M and 1.07 M, respectively. Statherin reached the IC50 value at 2.50 M. ANOVA and Student-Newman-Keuls tests for paired comparisons were applied to compare the values between the groups. DR9-DR9 amplified the inhibitory effect of hydroxyapatite crystal growth when compared to single DR9 (p <0.05), demonstrating that the multiplication of the functional domain is a strong protein evolution pathway. Interestingly, the hybrid peptide DR9-RR14 demonstrated an intermediate inhibitory effect when compared to other two groups: single DR9 and DR9-DR9. This study utilized the peptidomimetic approach to investigate a potential pathway of protein evolution related to duplication/hybridization of the natural peptidic constituents of the acquired enamel film. The knowledge obtained through the results of this work can provide a basis for the development of synthetic peptides for therapeutic use, both against dental caries and for periodontal disease.(AU)

Comparison of independent and dependent culture methods for the detection of transient bacteremia in diabetic subjects with chronic periodontitis / Comparación entre métodos de cultivo independientes y dependientes para la detección de bacteriemia transitoria en individuos diabéticos con periodontitis crónica

Introduction: Oral-derived bacteremia may occur after several dental procedures and routine daily activities. Some conditions of the oral cavity may favor episodes of bacteremia. This would be the case of patients with diabetes mellitus and periodontitis, who exhibit exacerbated gingival inflammation and may be more prone to developing oral-derived bacteremia. Objective: To compare the effectiveness of an independent culture method (quantitative real-time PCR- qCR) and the most commonly used method (BacT-ALERT 3D ® ) for the diagnosis of bacteremia. Materials and methods: Blood samples were drawn from subjects with type 2 diabetes mellitus and chronic periodontitis before and after apple chewing. Samples were processed by an automated blood culture system (BacT-ALERT 3D ® ) monitored for 15 days with suitable subculture of positive cultures. In parallel, whole DNA from blood samples was purified using a commercial kit and screened by qPCR using a universal primer set of 16S rDNA for bacteria detection. Results: Blood cultures taken before apple chewing were shown to be negative by the two diagnostic methods. After chewing, two samples (11%) showed bacterial growth by BacT-ALERT 3D ® whereas qPCR did not detect the presence of bacteria in any sample. Conclusions: qPCR did not show greater effectiveness than the BacT-ALERT 3D ® in the detection of bacteremia of oral origin.

Introducción. Las bacteriemias de origen oral pueden ocurrir después de procedimientos odontológicos y de otros actos cotidianos. Algunas condiciones de la cavidad oral favorecen las bacteriemias como en el caso de pacientes con diabetes mellitus y periodontitis que presentan inflamación gingival exacerbada. Objetivo. Comparar la eficacia de un método independiente de cultivo (PCR cuantitativa) y otro dependiente (BacT-ALERT 3D ® ) en la detección de la bacteriemia. Materiales y métodos. Se tomaron muestras de sangre de individuos con diabetes mellitus de tipo II y periodontitis, antes y después de la masticación de manzana. Una alícuota se procesó por el sistema automatizado de hemocultivo (BacT-ALERT 3D ® ) y se monitorizó durante 15 días; la otra alícuota fue tratada para la extracción del ADN y procesada por RT-PCR usando un conjunto de cebadores de 16S rDNA exclusivos para bacterias. Resultados. En las muestras tomadas antes de masticar se confirmó la ausencia de bacterias mediante los dos métodos. En las muestras tomadas después de masticar la presencia de bacterias se evidenció únicamente en dos hemocultivos y en ninguna de las muestras se detectó la presencia de bacterias con el método de RT-PCR. Conclusiones. La PCR cuantitativa no mostró mayor eficacia que el BacT-ALERT 3D ® en la detección de la bacteriemia de origen oral.

Mixed biofilms formed by C. albicans and non-albicans species: a study of microbial interactions

Abstract Most Candida infections are related to microbial biofilms often formed by the association of different species. The objective of this study was to evaluate the interactions between Candida albicans and non-albicans species in biofilms formed in vitro. The non-albicans species studied were:Candida tropicalis, Candida glabrata andCandida krusei. Single and mixed biofilms (formed by clinical isolates of C. albicans and non-albicans species) were developed from standardized suspensions of each strain (107 cells/mL), on flat-bottom 96-well microtiter plates for 48 hour. These biofilms were analyzed by counting colony-forming units (CFU/mL) in Candida HiChrome agar and by determining cell viability, using the XTT 2,3-bis (2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide colorimetric assay. The results for both the CFU/mL count and the XTT colorimetric assay showed that all the species studied were capable of forming high levels of in vitro biofilm. The number of CFU/mL and the metabolic activity of C. albicans were reduced in mixed biofilms with non-albicans species, as compared with a singleC. albicans biofilm. Among the species tested, C. krusei exerted the highest inhibitory action against C. albicans. In conclusion, C. albicans established antagonistic interactions with non-albicans Candida species in mixed biofilms.

Validación del método m­hidroxibifenilo para la cuantificación de ácido urónico en polisacáridos purificados de Streptococcus pneumoniae / Validation of the m-hydroxibiphenil method for the quantitation of uronic acid in purified Streptococcus pneumoniae polysaccharides

Introducción: la complejidad y diversidad estructural de los polisacáridos capsulares de Streptococcus pneumoniae hace que la metodología analítica necesaria para la caracterización y control de calidad sea engorrosa. El método colorimétrico m‒hidroxibifenil desarrollado por Blumenkrantz y Asboe‒Hansen en el año 1973, permite contrarrestar las desventajas del método propuesto en la Farmacopea Europea 6ta Edición, 2011. Objetivo: validar el método m‒hidroxibifenilo para cuantificar ácido urónico en polisacáridos purificados de streptococcus pneumoniae. Métodos: se determinó el tiempo de vigencia de la solución de tetraborato de sodio responsable de generar la respuesta analítica y se seleccionó una metodología para la cuantificación de ácido urónico por el método del m‒hidroxibifenilo se emplea una solución estándar de ácido galacturónico a 1 mg/mL. Se realizó una evaluación de los parámetros de validación: linealidad, exactitud, precisión, rango y especificidad, según exigencias actuales. Además se comparó con el método del carbazol descrito en la Farmacopea Europea 6ta Edición, 2011 para la cuantificación de ácido urónico. Resultados: se demostró que el tiempo de vida útil de la solución de tetraborato de sodio fue de 24 h. El método del m‒hidroxibifenilo fue específico, lineal, exacto y preciso en el rango de 2‒20 µg/mL porque se cumplieron satisfactoriamente los criterios de aceptación establecidos para cada uno de ellos. La comparación del método propuesto con el método normalizado reveló que no existieron diferencias estadísticamente significativas entre ambos(AU) Conclusión: el método colorimétrico del m‒hidroxibifenilo resultó válido para el control de calidad de las muestras de polisacárido purificado de Streptococcus pneumoniae, dando resultados comparables con el método recomendado en la Farmacopea Europea, 2011(AU)

Introduction: complexity and diversity in the structure of Streptococcus pneumoniae capsular makes the analytical methodology for characterization and quality control a troublesome aspect. The colorimetric m/hydroxibiphenil method devised by Blumenklrantz and Asboe-Hansen in 1973 allows reducing the disadvantages of the suggested method in the European Pharmacopea 6th edition, 2011. Objective: to validate the m-hydroxybiphenil method for quantitation of uronic acid in purified Streptococcus pneumonia polysaccharides. Methods: the length of validity of a sodium tetraborate solution, responsible for generating the analytical response, was estimated, and additionally, a methodology for quantitation of uronic acid by the m-hydroxybiphenil method was selected in which a standard galacturonic acid solution at 1mg/ml was used. The validation parameters were evaluated as follows: linearity, accuracy, precision, range and specificity, according to the present requirements. This method was compared with the carbazol method described in the European Pharmacopea 6th edition, 2011 for quantitation of uronic acid. Results: it was demonstrated that the useful lifetime of the sodium tetraborate solution was 24 hours. The m-hydroxybiphenil method was specific, linear, accurate and precise in the range of 2 to 20 ?g/mL because the set acceptance criteria were satisfactorily complied with for each of them. The comparison of the suggested method with the standardized method yielded that no statistically significant differences exist between them. Conclusions: the colorimetric m-hydroxybiphenil method proved to be valid for the quality control of purified Streptococcus pneumonia polysaccharide samples and the results are comparable to those of the recommended method in the European Pharmacopea, 2011(AU)

A high-throughput screening assay for distinguishing nitrile hydratases from nitrilases

A modified colorimetric high-throughput screen based on pH changes combined with an amidase inhibitor capable of distinguishing between nitrilases and nitrile hydratases. This enzymatic screening is based on a binary response and is suitable for the first step of hierarchical screening projects.

Atividade in vitro de plantas condimentares (Rosmarinus officinalis L., Lippia graveolens HBK e Thymus vulgaris L. ) contra o calicivírus felino / In vitro activity of plants used as condiments (Rosmarinus officinalis L., Lippia graveolens HBK e Thymus vulgaris L. ) against the feline calicivirus

O calicivírus felino (FCV) é um importante patógeno de gatos que causa lesões ulcerativas orais e infecções respiratórias. O vírus tem sido utilizado como modelo experimental para avaliação de agente antivirais contra norovírus (NoVs). Nesse estudo, investigou-se a ação dos óleos essenciais de alecrim (Rosmarinus officinalis L.), orégano mexicano (Lippia graveolens HBK.) e tomilho (Thymus vulgaris L.) frente ao FCV, in vitro. A toxicidade celular foi testada pelo método de MTT e os ensaios antivirais pelo teste de redução de placas. Três protocolos foram aplicados: a) diferentes concentrações não tóxicas dos óleos essenciais (CNTOE) foram incubadas com o vírus por 1 hora antes da inoculação (ensaio virucida); b) CNTOE foram adicionadas às células CRFK e incubadas por 1 hora antes da adsorção viral (ensaio de pré-tratamento); c) CNTOE foram adicionadas às células após a inoculação do FCV e mantidas por 18 horas (ensaio de pós-tratamento). A CC 50 para os óleos de alecrim, orégano mexicano e tomilho foram: 1300,21 ?g mL -1 ; 435,92 ?g mL -1 e 675,34 ?g mL -1 ; respectivamente. O óleo essencial de tomilho apresentou índice de seletividade [IS=CC 50 /CI 50 ] de 8,57 para o ensaio de pré-tratamento e 6,2 no ensaio virucida. O óleo de alecrim mostrou atividade antiviral no ensaio virucida (IS=6,54) e de pós-tratamento (IS=6,86). O orégano mexicano apresentou IS de 5,75 no ensaio virucida e 5,59 no de pós-tratamento. Conclui-se que os óleos essenciais de tomilho e alecrim apresentaram atividade frente ao FCV em diferentes momentos da infecção viral.(AU)

The feline calicivirus (FCV) is an important pathogen of feline causing oral ulcerative lesions and respiratory disease. This virus has been used as a model to evaluate antiviral compounds against Norovirus (NoVs). In this study, the essential oils of rosemary (Rosmarinus officinalis L.), mexican oregano (Lippia graveolens HBK) and thyme (Thymus vulgaris L.) were examined for their activity towards FCV, in vitro. The cytotoxicity was determined by the MTT test and the antiviral assays were performed by the plaque reduction test. Three protocols were applied: a) different non-toxic concentrations of the essential oils (NTCEO) were incubated with the virus for 1 hour before viral inoculation (virucidal assay); b) NTCEO were added to CRFK cells and incubated for 1 hour before viral adsorption (pre-treatment assay); c) NTCEO were added to cells after virus inoculation and maintained for 18 hours (post-treatment assay). The cytotoxic concentration at 50% (CC 50 ) for the essential oils of rosemary, mexican oregano, and thyme were: 1300.21 ?g mL -1 ; 435.92 ?g mL -1 and 675.34 ?g mL -1 ; respectively. The essential oil of thyme showed a selectivity index (IS=CC 50 /CI 50 ) of 8.57 at the cell pre-treatment assay and 6.2 at the virucidal assay. The essential oil of rosemary showed antiviral activity at the virucidal assay (IS=6.54) and, also, at the post- treatment assay (IS=6.86). The mexican oregano showed an IS of 5.75 at the virucidal assay and 5.59 at the post-treatment. Therefore, it can be concluded that the essential oils of thyme and rosemary show antiviral activity against FCV in different times of the infection.(AU)

Development and application of a portable instrument for drugs analysis in pharmaceutical preparations

This article describes the application and performance of an inexpensive, simple and portable device for colorimetric quantitative determination of drugs in pharmaceutical preparations. The sensor is a light detector resistor (LDR) incorporated into a black PTFE cell and coupled to a low-cost multimeter (Ohmmeter). Quantitative studies were performed with captopril/p-chloranil/H2O2 and methyldopa/ammonium molybdate systems. Calibration curves were obtained by plotting the electrical resistance of the LDR against the concentration of the colored species in the ranges 1.84 × 10-4 to 1.29 × 10-3mol L-1 and 5.04 × 10-4 to 2.52 × 10-3 mol L-1 for captopril/p-chloranil/H2O2 and methyldopa/ammonium molybdate systems, respectively, exhibiting good coefficients of determination. Statistical analysis of the results obtained showed no significant difference between the proposed methodologies and the official reported methods, as evidenced by the t-test and variance ratio at a 95% confidence level. The results of this study demonstrate the applicability of the instrument for simple, accurate, precise, fast,in situ and low-cost colorimetric analysis of drugs in pharmaceutical products.

Este artigo descreve o desenvolvimento e a aplicação de um dispositivo portátil, simples e barato para a determinação colorimétrica quantitativa de fármacos em formulações farmacêuticas. O sensor é um resistor detector de luz (RDL) colocado numa célula de PTFE e acoplado a um multímetro de baixo custo. Os estudos quantitativos foram realizados utilizando captopril/p-cloranil/H2O2 e metildopa/molibdato de amônio como sistemas reacionais. As curvas de calibração foram obtidas através da representação gráfica da resistência elétrica do RDL contra a concentração dos complexos coloridos formados nas faixas de 1,84 × 10-4 e 1,29 × 10-3 mol L-1 e 5,04 × 10-4 e 2,52 × 10- 3 mol L-1 para captopril/p-cloranil/H2O2 e de metildopa/molibdato de amônio, respectivamente, com bons coeficientes de determinação. As análises estatísticas dos resultados obtidos mostraram que não houve diferença significativa entre os métodos propostos e os métodos oficiais como evidente a partir dos testes "t-Student" eF-Fisher, com nível de confiança de 95%. Os resultados deste estudo demonstram que o instrumento proposto neste trabalho é simples, de fácil operação, baixo custo e apresentou boa exatidão e boa precisão para o doseamento de fármacos em medicamentos.

Proteus mirabilis biofilm - Qualitative and quantitative colorimetric methods-based evaluation

Proteus mirabilis strains ability to form biofilm is a current topic of a number of research worldwide. In this study the biofilm formation of P. mirabilis strains derived from urine of the catheterized and non-catheterized patients has been investigated. A total number of 39 P. mirabilis strains isolated from the urine samples of the patients of dr Antoni Jurasz University Hospital No. 1 in Bydgoszcz clinics between 2011 and 2012 was used. Biofilm formation was evaluated using two independent quantitative and qualitative methods with TTC (2,3,5-triphenyl-tetrazolium chloride) and CV (crystal violet) application. The obtained results confirmed biofilm formation by all the examined strains, except quantitative method with TTC, in which 7.7% of the strains did not have this ability. It was shown that P. mirabilis rods have the ability to form biofilm on the surfaces of both biomaterials applied, polystyrene and polyvinyl chloride (Nelaton catheters). The differences in ability to form biofilm observed between P. mirabilis strains derived from the urine of the catheterized and non-catheterized patients were not statistically significant.

Cultivo de cepas de levaduras de suelo trumao en ®vinaza¼ / Cultivation of yeast strains of the trumao soil in ®vinasse¼

30 cepas de levaduras aisladas desde un suelo trumao (Hapludans) usado como pradera en rotación, se cultivaron individualmente (100 µl = a 102 ufc delevaduras/mL) en matraces con 50 mL de ®vinaza¼, estos fueron incubados en un agitador orbital a 150 rpm, 23 °C por 5 días, luego de la incubación el contenido de cada matraz se centrifugo a 3.500 rpm por 20 min., a los pellet obtenidos se les determino: el peso seco (PS); fosforo total (FT) por digestión ácida y posterior lectura a 400 nm; proteínas totales (PT) por colorimetría Biuret a 595 nm y lípidos totales (LT) mediante el método colorimétrico de la sulfo-fosfo vainillina a 520 nm. Las 30 cepas de levaduras crecieron en la vinaza. El mayor PS lo registro la cepa 25 (331 g de levadura L-1 de ®vinaza¼). FT lo registro la cepa 28 (4,8 mg g-1 de levadura seca). PT lo registro la cepa 24 (25,90 mg g-1 de levadura seca) y LT lo registro la cepa 18 (287,4 mg g-1 de levadura seca).

Thirty strains of yeast isolated from a volcanic ash soil (Hapludans), used as pasture rotation, were individually cultured (100 µl = 102 cfu of yeast cells mL-1) in flasks with 50 mL of ®vinasse¼, these were incubated at 23 °C for 5 day, after incubation the contents of each flask was centrifuged at 3500 rpm for 20 min, the pellet obtained was determined: dry weight (DW); total phosphorus (FT) by acid digestion and later reading at 400 nm; total protein (TP) by Biuret at 595 nm and total lipid (TL) by the colorimetric method of the sulfo-phospho-vanillin at 520 nm. The Thirty strains of yeast grown on vinasse. The best DW, was determined for strain 25 (331 g yeast L-1 ®vinasse¼). FT was determined for strain 28 (4,8 mg g-1 dry yeast). TP was determined for strain 24 (25, 90 mg g-1 dry yeast) and TL was determined for strain18 (287, 4 mg g-1 dry yeast).

Development of bioconjugate from Streptomyces tyrosinase and gold nanoparticles for rapid detection of phenol constituents.

Most of the phenol compounds are toxic and have been considered as hazardous pollutants. Several physicochemical and biological methods are available to detect and monitor the phenol pollutants in water and soil. In the present study, phenol constituents of winery, paper and plastic industrial effluents were successfully detected employing tyrosinase-gold nanoparticles bioconjugate. The synthesis of extracellular tyrosinase and gold nanoparticles was achieved by a single isolate of Streptomyces sp. DBZ-39. Enhanced production (369.41 IU) of tyrosinase was produced in submerged bioprocess employing response surface method with central composite design. Extracellular gold nanoparticles synthesized (12-18 nm) by Streptomyces sp. DBZ-39 were characterized with TEM, EDAX and FTIR analysis. A rapid detection (within 10 min) of phenol constituents from winery effluents was achieved by bioconjugate, when compared to tyrosinases and gold nanoparticles independently. Streptomyces tyrosinase could exhibit relatively a better performance than commercially available mushroom tyrosinase in the detection of phenol constituents. Winery effluent has shown much higher content (0.98 O.D) of phenol constituents than paper and plastic effluents based on the intensity of color and U.V absorption spectra.

Quantificação do ácido 5-hidroxi-indolacético urinário por técnica caseira do nitrosonaftol comparada com ensaio de nitrosonaftol em microcoluna de cromatografia e imunoensaio enzimático / Quantification of urinary 5-hydroxyindoleacetic acid by in-house nitrosonaphthol reaction compared with nitrosonaphthol micro column chromatography and enzyme-linked immunosorbent assay

The aim of this study was to compare the colorimetric "kit" and enzyme-linked immunosorbent assay (ELISA) methods to quantify urinary 5-hydroxyindoleacetic acid through the Goldenberg's technique, exploring the potential of replacing it. 24-hour urine samples were tested by Goldenberg's assay and compared with kits. The agreement was almost perfect for the comparison of Goldenberg's assay with both colorimetric kit, and with ELISA kit, considering ≤ 7.5 mg/24h normal cutoff value. Therefore, both "kits" would be good alternatives to Goldenberg's technique due to practicality and agreement between values...

O objetivo deste estudo foi comparar métodos por kit colorimétrico e por ensaio imunossorvente ligado à enzima (ELISA) para quantificar o ácido 5-hidroxi-indolacético urinário com a técnica de Goldenberg, explorando o potencial de substituí-la. Amostras de urina de 24 horas foram testadas pela técnica de Goldenberg e com os kits. A concordância foi quase perfeita, tanto para a comparação do ensaio de Goldenberg com o kit colorimétrico quanto para com o kit ELISA, considerando normal o valor de corte de ≤ 7.5 mg/24h. Portanto, ambos os kits seriam boa alternativa para a técnica de Goldenberg devido à praticidade e à concordância entre os valores...

A new rapid colourimetric method for testing Mycobacterium tuberculosis susceptibility to isoniazid and rifampicin: a crystal violet decolourisation assay

The aim of this study was to investigate the performance of a new and accurate method for the detection of isoniazid (INH) and rifampicin (RIF) resistance among Mycobacterium tuberculosis isolates using a crystal violet decolourisation assay (CVDA). Fifty-five M. tuberculosis isolates obtained from culture stocks stored at -80ºC were tested. After bacterial inoculation, the samples were incubated at 37ºC for seven days and 100 µL of CV (25 mg/L stock solution) was then added to the control and sample tubes. The tubes were incubated for an additional 24-48 h. CV (blue/purple) was decolourised in the presence of bacterial growth; thus, if CV lost its colour in a sample containing a drug, the tested isolate was reported as resistant. The sensitivity, specificity, positive predictive value, negative predictive value and agreement for INH were 92.5%, 96.4%, 96.1%, 93.1% and 94.5%, respectively, and 88.8%, 100%, 100%, 94.8% and 96.3%, respectively, for RIF. The results were obtained within eight-nine days. This study shows that CVDA is an effective method to detect M. tuberculosis resistance to INH and RIF in developing countries. This method is rapid, simple and inexpensive. Nonetheless, further studies are necessary before routine laboratory implementation.