Lernaea cyprinacea Linnaeus, 1758 (Copepoda: Lernaeidae) infection on Betta rubra Perugia, 1893 (Anabantiformes: Osphronemidae) from Aceh Province, Indonesia / Infecção por Lernaea cyprinacea Linnaeus, 1758 (Copepoda: Lernaeidae) em Betta rubra Perugia, 1893 (Anabantiformes: Osphronemidae) provenientes da província de Aceh, Indonésia

Abstract Betta rubra is an ornamental freshwater fish endemic to northern Sumatra, Indonesia. The B. rubra population has decreased in recent decades, and is classified as an endangered species in the IUCN Red List. This study aims to report for the first time infection by L. cyprinacea in B. rubra harvested from the Aceh Besar region of Indonesia. The fish samples were obtained from the Cot Bira tributaries, Aceh Besar District, Indonesia from January to December 2020. The results showed that the parasite infected 6 out of 499 samples in August and September, with a prevalence and intensity rate of 1% and 2 parasites/fish, respectively. The eyes and pectoral fins were the common infection sites. Despite B. rubra is not an optimal host (small size) for the parasite, this parasite might serve as additional threatening factors for the endangered B. rubra fish population.

Resumo Betta rubra é um peixe de água doce ornamental endemico da região norte Sumatra, Indonesia. A população de Betta rubra diminuiu ao longo dos anos, sendo classificada como espécie em extinção na Lista Vermelha da IUCN. Este estudo tem como objetivo relatar pela primeira vez infecção por L. cyprinacea em B. rubra coletados na região de Aceh Besar na Indonésia. As amostras de peixes foram obtidas nos afluentes Cot Bira, distrito de Aceh Besar, Indonésia de janeiro a dezembro de 2020. Os resultados mostraram que o parasito infectou 6 das 499 amostras em agosto e setembro, com uma prevalência e taxa de intensidade de 1% e 2 parasitas/peixes, respectivamente. Os olhos e as nadadeiras peitorais foram os sítios de infecção mais comuns. Apesar de B. rubra não ser um hospedeiro ideal (pequeno tamanho) para o parasita, este parasita pode servir como fator de ameaça adicional para a população de peixes B. rubra, ameaçada de extinção.

Silicone plastination of nasus and lingua in large ruminants with and without use of formaldehyde / Plastinación de silicona de nasus y lengua en rumiantes mayores con y sin el uso de formaldehido

SUMMARY: Plastination is an anatomical preparate preparation technique characterized by the replacement of tissue fluids with a reactive polymer. Although more challenging and economically costly than many anatomical methods, this method is desirable because of the fact that specimens created in this method are highly similar to the natural appearance of the intended objects, and they are durable and harmless end products for human health. Our main goal was to completely leave out formaldehyde and similar carcinogenic chemicals used in a method like plastination and to allow production of formaldehyde-free plastinates to be used in anatomy training and examinations in our country. To that end, we compared nose and tongue of 10 large ruminants by subjecting them to plastination, 5 of them with formaldehyde and 5 of them without formaldehyde, and aimed to leave formaldehyde out by taking into account the difference between them. Silicone plastination is the most commonly-used and best-known technique among the plastination techniques because specimens created using this technique look aesthetically impressive. Silicone plastination consists mainly of 5 phases. First of all, we obtained the anatomical situs we wanted and made specimens ready by dissecting some of them after fixation and some of them without fixation. Then, after the implementation of a dehydration phase in acetone baths at -25 °C, a forced impregnation phase was implemented by using a mixture of S10-S3 chemical under negative pressure. In the final phase, the curing and hardening phase, the plastination process was completed by giving the specimens their final shape with the use of the S6 solution. As a result, no significant difference was observed between silicone plastination with and without formaldehyde.

RESUMEN: La plastinación es una técnica de preparados anatómicos caracterizada por la sustitución de fluidos tisulares por un polímero reactivo. A pesar de ser económicamente más costoso que muchas métodos anatómicos, este técnica es deseable debido a que las muestras creadas son muy similares a la apariencia natural de los objetos previstos y son productos finales duraderos e inofensivos para la salud humana. Nuestro objetivo principal fue dejar completamente de lado el formaldehído y las sustancias químicas cancerígenas similares utilizadas en un método como la plastinación y permitir la producción de plastinados libres de formaldehído para su uso en la formación y los exámenes de anatomía en nuestro país. Con ese fin, comparamos la nariz y la lengua de 10 rumiantes mayores sometiéndolos a plastinación, 5 de ellos con formaldehído y 5 de ellos sin formaldehído, y buscamos eliminar el formaldehído considerando la diferencia entre ellos. La plastinación con silicona es la técnica más utilizada y más conocida entre las técnicas de plastinación porque los especímenes creados con ella se ven estéticamente impresionantes. La plastinación con silicona consta principalmente de 5 fases. En primer lugar, obtuvimos el situs anatómico que queríamos y preparamos los especímenes diseccionando algunos de ellos después de la fijación y otros sin fijación. Luego, de la implementación de una fase de deshidratación en baños de acetona a -25 °C, se implementó una fase de impregnación forzada utilizando una mezcla del químico S10-S3 a presión negativa. En la fase final, la fase de curado y endurecimiento, se completó el proceso de plastinación dando a los especímenes su forma definitiva con el uso de la solución S6. Como resultado, no se observaron diferencias significativas entre la plastinación con silicona con y sin formaldehído.

Estudo da eficácia de encapsulação da Cinarizina em cubossomos não-iônicos: caracterização estrutural e citotóxica / Study of the encapsulation efficacy of Cinnarizine in non-ionic cubosomes: structural and cytotoxic characterization

Os cubossomos são partículas nanoestruturadas em forma de bicamada lipídica, bicontínuas e altamente curvadas, as quais devem ser estabilizadas por um polímero não-iônico, neste caso o Pluronic® F-127. Podem ser compostos por alguns tipos de lipídios específicos que possuem a capacidade de se auto associar em estruturas cúbicas quando estão em excesso de água, como o fitantriol (PHY) e a monoleína (GMO). Devido a sua estrutura única, cubossomos possuem um grande potencial para serem considerados como sistemas drug delivery. Os sistemas drug delivery são amplamente utilizados na pesquisa farmacêutica e em contextos clínicos para aumentar a eficácia de compostos utilizados para diagnóstico e de fármacos. No caso da cinarizina (CNZ), fármaco já aprovado para o tratamento de náuseas, vômitos e vertigens causadas pela doença de Ménière, existem inúmeros efeitos colaterais associados a sua baixa solubilidade. Desta forma, a encapsulação em cubossomos se torna uma abordagem promissora para resolver os problemas de atividade farmacológica relacionados ao fármaco. Neste trabalho, realizamos uma caracterização biofísica da interação da CNZ em cubossomos (contendo PHY ou myverol, MYV, sendo este composto por 80% de GMO). As técnicas biofísicas utilizadas foram: espalhamento de raios-X em baixos ângulos (SAXS), espalhamento dinâmico de luz (DLS), microscopia eletrônica de transmissão (TEM), crio microscopia eletrônica de transmissão (Crio-TEM), análise de rastreamento de nanopartículas (NTA) e potencial zeta. A cromatografia líquida de alta eficiência (HPLC) foi realizada para verificar a porcentagem de eficiência de encapsulação (%EE) da CNZ nos cubossomos, enquanto que a citotoxicidade foi avaliada em eritrócitos através da análise da atividade hemolítica. Inicialmente, a influência de diferentes solventes (acetona, clorofórmio, etanol e octano) nas propriedades estruturais de cubossomos de PHY foi investigada, a fim de se minimizar os efeitos do solvente utilizados para a encapsulação da CNZ. Para amostras com acetona, descobriu-se que apenas altas concentrações tiveram influência na estrutura cristalográfica das nanopartículas, sendo o resultado foi totalmente reversível após 24h. O etanol fez com que o parâmetro de rede aumentasse de 10-15%. O clorofórmio e o octano tiveram efeitos diferentes sobre cubossomos de PHY em comparação com a acetona e o etanol; ambos induziram uma transição cúbico-hexagonal-micelar. Posteriormente, constatamos que as nanopartículas de PHY e MYV apresentaram diferentes estruturas cristalográficas, sendo elas Pn3m e Im3m, respectivamente. Devido a problemas com a baixa solubilidade de CNZ em PHY os estudos para esse lipídio foram suspensos. Nos testes para cubossomos de MYV ao incorporar a CNZ foi observado uma alteração da estrutura cúbica de Im3m para Pn3m e os valores dos parâmetros de rede se alteraram de acordo com a estrutura cristalina encontrada, porém os valores não apresentaram diferenças significativas de tamanho quando se trata da mesma estrutura, sugerindo que a CNZ não interferiu no parâmetro de rede. Os tamanhos das nanopartículas apresentaram uma população monodispersa com ~200 nm. DLS mostrou uma interferência da CNZ no tamanho dos cubossomos, variando de forma diretamente proporcional a concentração de CNZ na amostra, enquanto as técnicas de NTA e microscopia apresentaram nanopartículas de tamanhos bastante variados, mas independente da interferência da CNZ. A encapsulação de CNZ também foi dosada por HLPC em cubossomos de MYV, obtendo um limite superior de 0,6 mg/mL. A atividade citotóxica dos cubossomos foi testada em eritrócitos, revelando uma taxa de hemólise bastante inferior em cubossomos com CNZ em relação a cubossomos puros. Acreditamos que os cubossomos podem sim ser utilizados como sistemas carreadores de CNZ

Cubosomes are nanostructured particles in the form of a lipid bilayer, bicontinuous and highly curved, which must be stabilized by a non-ionic polymer, in this case Pluronic® F-127. They can be composed of some types of specific lipids that have the ability to self-associate in cubic structures when they are in excess of water, such as phytantriol (PHY) and monolein (GMO). Due to their unique structure, cubosomes have a great potential to be considered as drug delivery systems. Drug delivery systems are widely used in pharmaceutical research and clinical settings to increase the efficacy of compounds used for diagnostics and drugs. In the case of cinnarizine (CNZ), a drug already approved for the treatment of nausea, vomiting and vertigo caused by Ménière's disease, there are numerous side effects associated with its low solubility. Thus, cubosomal encapsulation becomes a promising approach to solve drug-related problems of pharmacological activity. In this work, we performed a biophysical characterization of the CNZ interaction in cubosomes (containing PHY or myverol, MYV, which is composed of 80% GMO). The biophysical techniques used were: low angle X-ray scattering (SAXS), dynamic light scattering (DLS), transmission electron microscopy (TEM), cryo transmission electron microscopy (Crio-TEM), nanoparticle tracking analysis (NTA) and zeta potential. High performance liquid chromatography (HPLC) was performed to verify the percentage of encapsulation efficiency (%EE) of CNZ in cubosomes, while cytotoxicity was evaluated in erythrocytes by analyzing the hemolytic activity. Initially, the influence of different solvents (acetone, chloroform, ethanol and octane) on the structural properties of PHY cubosomes was investigated in order to minimize the effects of the solvent used for the encapsulation of CNZ. For samples with acetone, it was found that only high concentrations had an influence on the crystallographic structure of the nanoparticles, with the result being fully reversible after 24h. Ethanol caused the network parameter to increase by 10-15%. Chloroform and octane had different effects on PHY cubosomes compared to acetone and ethanol; both induced a cubic-hexagonal-micellar transition. Later, we found that PHY and MYV nanoparticles presented different crystallographic structures, being Pn3m and Im3m, respectively. Due to problems with the low solubility of CNZ in PHY, studies for this lipid were suspended. In the tests for MYV cubosomes when incorporating CNZ, a change in the cubic structure from Im3m to Pn3m was observed and t he lattice parameters changed according to the crystal structure found, but the differences observed were not significant when it comes to the same structure, suggesting that the CNZ did not interfere with the network parameter. The nanoparticle sizes showed a monodisperse population with ~200 nm. DLS showed an interference of CNZ in the size of the cubosomes, varying directly proportionally to the concentration of CNZ in the sample, while NTA and microscopy techniques showed nanoparticles of widely varying sizes, but independent of CNZ interference. CNZ encapsulation was also dosed by HLPC in MYV cubosomes, obtaining an upper limit of 0.6 mg/ml. The cytotoxic activity of cubosomes was tested in erythrocytes, revealing a much lower rate of hemolysis in cubosomes with CNZ compared to pure cubosomes. We believe that cubosomes can indeed be used as CNZ carrier systems

Comparison of protein precipitation methods for sample preparation prior to proteomic analysis of Chinese hamster ovary cell homogenates

BACKGROUND: Chinese hamster ovary (CHO) cells are the workhorse for obtaining recombinant proteins. Proteomic studies of these cells intend to understand cell biology and obtain more productive and robust cell lines for therapeutic protein production in the pharmaceutical industry. Because of the great importance of precipitation methods for the processing of samples in proteomics, the acetone, methanol-chloroform (M/C), and trichloroacetic acid (TCA)-acetone protocols were compared for CHO cells in terms of protein recovery, band pattern resolution, and presence on SDS-PAGE. RESULTS: Higher recovery and similar band profile with cellular homogenates were obtained using acetone precipitation with ultrasonic bath cycles (104.18 ± 2.67%) or NaOH addition (103.12 ± 5.74%), compared to the other two protocols tested. TCA-acetone precipitates were difficult to solubilize, which negatively influenced recovery percentage (77.91 ± 8.79%) and band presence. M/C with ultrasonic homogenization showed an intermediate recovery between the other two protocols (94.22 ± 4.86%) without affecting protein pattern on SDS-PAGE. These precipitation methods affected the recovery of low MW proteins (< 15 kDa). CONCLUSIONS: These results help in the processing of samples of CHO cells for their proteomic study by means of an easily accessible, fast protocol, with an almost complete recovery of cellular proteins and the capture of the original complexity of the cellular composition. Acetone protocol could be incorporated to sample-preparation workflows in a straightforward manner and can probably be applied to other mammalian cell lines as well.

Evaluation of the action of precipitating agents to obtain allergenic proteins from crude mite extracts / Avaliação da ação de agentes precipitantes na obtenção de proteínas alergênicas presentes em extratos brutos de ácaros

Introduction: Allergen proteins found in dust mite extracts, such as Dermatophagoides farinae (DF), Dermatophagoides pteronyssinus (DP) and Tyrophagus putrescentiae (TP), are relevant for scientific studies in the allergy and immunotherapy fields. The precipitation/concentration of protein extracts may favor the aggregation of the allergens in homogenates. Objective and method: This paper investigates the precipitation process by submitting crude mite extracts to compounds such as ammonium sulfate (NH4)2SO4, trichloroacetic acid (TCA) and acetone. Results: The best results were obtained by fractionation with (NH4)2SO4 at 80% (w/v) saturation (~0° C), observing the protein markings on the electrophoresis gel. Major allergens were identified by immunoblot at 25 kDa (cysteine protease) for Der f and Der p; and 25 kDa, 30 kDa (tropomyosin) and Try p 3, near 26 kDa. For this percentage the total protein contents were 12.83 mg mL-1 for Der f, 24.78 mg mL-1 for Der p and 27.35 mg mL-1 for Try. Conclusion: An advantage of precipitation with (NH4)2SO4 over precipitation with acetone was the possibility of gradually obtaining protein fractions, which does not happen when using the latter. The addition of 80% (v/v) acetone to the mite extracts favored total protein precipitation in the concentrations 16.42 mg mL-1, 28.47 mg mL-1 and 13.41 mg mL-1. The use of TCA in concentrations above 20% (w/v) forms peptides that are not retained in the gel under the established experimental conditions, and dilute solutions of this acid are more efficient.

Introdução: As proteínas alergênicas presentes nos extratos dos ácaros de poeira, tais como Dermatofagoides farinae (DF), Dermatofagoides pteronyssinus (DP) e Tyrophagus putrescentiae (TP) são relevantes para estudos científicos na área de alergias e aplicação em imunoterapias. A precipitação/concentração desses extratos proteicos pode favorecer a agregação de alérgenos nos homogenatos. Objetivo e método: O trabalho investiga o processo de precipitação, submetendo os extratos brutos de ácaros de poeira a compostos como sulfato de amônio (NH4)2SO4, ácido tricloroacético (ATC) e acetona. Resultados: Os melhores resultados foram obtidos por fracionamento com (NH4)2SO4 em 80% (m/v) de saturação (~ 0°C), observando as marcações proteicas no gel de eletroforese. Os alérgenos principais foram identificados por immunoblot em 25 kDa (cisteína protease) para Der f 1 e Der p 1; e 25 kDa, 33 kDa (tropomyosin), 11 kDa para Tyr. Para esse percentual, os teores de proteína total foram de 12.83 mg mL-1 para DF; 24,78 mg mL-1 para DP; e 27,35 mg mL-1 para TP. Conclusão: A vantagem da precipitação com (NH4)2SO4 frente à precipitação com acetona foi a possibilidade de gradativamente se obter frações proteicas, o que não acontece quando utilizado esse solvente. A adição de 80% (v/v) de acetona aos extratos de ácaros favoreceu a precipitação total de proteína nas concentrações 16,42 mg mL-1; 28,47 mg mL-1; e 13,41 mg mL-1. O uso de ATC em concentrações acima de 20% (m/v) forma peptídeos que não são retidos no gel nas condições experimentais estabelecidas, sendo eficiente soluções mais diluídas desse ácido.

Acetone­butanol­ethanol fermentation from sugarcane bagasse hydrolysates: utilization of C5 and C6 sugars

Background: Fuels and chemicals from renewable feedstocks have a growing demand, and acetone, butanol and ethanol (ABE) are some relevant examples. These molecules can be produced by the bacterial fermentation process using hydrolysates generated from lignocellulosic biomass as sugarcane bagasse, one of the most abundant sources of lignocellulosic biomass in Brazil. It originates as a residue in mills and distilleries in the production of sugar and ethanol. Results: In the present work, two strategies to generate hydrolysates of sugarcane bagasse were adopted. The fermentation of the first hydrolysate by Clostridium acetobutylicum DSM 6228 resulted in final concentrations of butanol, acetone and ethanol of 6.4, 4.5 and 0.6 g/L, respectively. On the other hand, the second hydrolysate presented better results (averages of 9.1, 5.5 and 0.8 g/L, respectively), even without the need for nutrient supplementation, since key elements were already present in the medium. The productivity (QP) and yield (YP/S) of the solvents with second hydrolysate were 0.5 g/L•h-1 and 0.4 g/g, respectively. Conclusions: The results described herein open new perspectives for the production of important molecules from residual lignocellulosic biomass for the fuel and chemical industries within the context of second-generation biorefinery.

Proteomic analysis of latex from Jatropha curcas L. stems and comparison of two classic proteomic sample isolation methods: the phenol extraction and the TCA/acetone extraction

Background: Jatropha curcas is a wide-spreading latex-rich biodiesel plant with high oil content in seeds that have always been under intense studies. However, studies are lacking on the latex component that is considered rich in proteins with potentially important physiological functions and secondary metabolites that are a promising source for new drugs. The proteomic analysis, which would be the first step to study these substances, was hampered by the presence of interfering components. Phenol extraction and Trichloroacetic acid (TCA)/ acetone extraction, two major plant proteomic isolation methods, were used and compared in this study. Results: We identified 459 proteins from the J. curcas latex proteome using the combination of the two extraction techniques. Although more number of latex proteins were identified by the phenol extraction (401 proteins vs. 123 proteins by the TCA/acetone extraction), only 65 proteins were commonly isolated by both methods. Analysis of the biochemical properties revealed that relatively more number of lower isoelectric point (pI) proteins were isolated by the TCA/acetone method (pI mode: 4.79, 6.51 for phenol). Moreover, GO, COG, and KEGG analyses showed that certain classes/categories/pathways annotated more number of proteins than others, and most of them had proportionally comparable protein counts by both the methods, however, with exemplified exceptions. Conclusions: A large number of proteins were found and exclusively identified by either method, indicating that a better proteome coverage of plant samples in a similar context needs the combined use of multiple isolation methods. In addition, the core biological function of the latex may be uncovered by certain GO, COG, and KEGG classes/categories/pathways that annotate more proteins.

Evaluación de la actividad antifúngica de extractos liquénicos e identificación de sus metabolitos / Evaluation of the fungicide activity from lichens extracts and identification their metabolites

Los líquenes son los hongos que establecen una relación simbiótica con un alga o cianobacteria. En esta simbiosis se producen por parte del hongo, una serie de metabolitos secundarios conocidos como sustancias liquénicas; las cuales presentan una marcada actividad antibiótica. En Cuba no se tienen antecedentes sobre estudios de metabolitos liquénicos por lo que se propone; evaluar el efecto fungicida de extractos liquénicos producidos por especies cubanas así como identificar sus metabolitos. Se emplearon líquenes de diferentes zonas del país (Parmotrema dilatatum, P. tinctorum, P. praesorediosum P. cristiferum, Ramalina americana, Cladonia ceratophylla y Cladonia portentosa spp. pacífica), a los cuales se les extrajo con acetona, las sustancias liquénicas almacenadas en el talo. Los extractos fueron probados contra los hongos fitopatógenos Rhizoctonia solani y Phythophtora nicotianae; por el método de envenenamiento del medio de cultivo agar papa dextrosa a concentraciones de: 0,01 por ciento; 0,03 por ciento y 0,07 por ciento. Se utilizó un control negativo de dimetilsufóxido al 0,07 por ciento y se determinaron los porcentajes de inhibición, cuyos resultados fueron analizados estadísticamente. Los metabolitos secundarios presentes en los extractos se identificaron por cromatografía de capa fina (TLC). Exceptuando el extracto liquénico de P. cristiferum, todos los demás mostraron más de un 50 por ciento de inhibición del crecimiento de ambos hongos a la concentración de 0,07 por ciento, mientras que a las restantes concentraciones los valores fueron variados con diferencias significativas con respecto al control. Se lograron identificar tres metabolitos liquénicos: metil 2‘-O- metilmicrofilinato, 4-O-Demetilmicrofilinico y el ácido ramaniloico.

Lichens are fungi that establish a symbiotic relationship with an alga or cyanobacterium. This symbiosis produced by the fungus, a series of secondary metabolites known as lichen substances; which show a strong antibiotic activity. In Cuba there is no background on the studies above lichen metabolites so it is proposed; evaluate the fungicidal activity of lichen extracts produced by Cuban species and to identify metabolites. Lichens from different areas of the country (Parmotrema dilatatum, P. tinctorum, P.praesorediosum, P. cristiferum, Ramalina americana, Cladonia ceratophylla and Cladonia portentosa spp. pacífica), to which it extracted with acetone, the lichen substances stored in tallus. The extracts were tested against the fungal pathogens Rhizoctonia solani and Phythophtora nicotianae; poisoning by the method of culture medium potato dextrose agar at concentrations of 0.01 percent; 0.03 percent and 0.07 percent. A negative control to 0.07 percent dimethylsulfoxide was used and the percentage of inhibition, the results were analyzed statistically determined. Secondary metabolites present in the extracts were identified by thin layer chromatography (TLC). Except P. cristiferum lichen extract, all others showed more than 50 percent growth inhibition of both fungi at concentration of 0.07 percent, while the remaining concentrations were varied values with significant differences from the control. Was made to identify three lichen metabolites metilmicrofilinato 2‘ methyl-O, 4-ODemetilmicrofilinico and ramaniloico acid.

Avaliação da eficácia da desinfecção de instrumentos usados durante o período transoperatório do tratamento endodôntico / Evaluation of the desinfection efficacy of instruments used during the transoperatory period in endodontic treatment

Esta investigação objetivou a eficácia antimicrobiana de agentes desinfetantes utilizados na desinfecção dos instrumentos endodônticos, durante o período transoperatório do tratamento endodôntico. A atividade antimicrobiana dos desinfetantes álcool isopropílico, acetona e ácido peracético (PAA) foi avaliada sobre microrganismos planctônicos através de teste de contato (time kill assay), utilizando inóculo de 9,9 X 109 a 1,2 X 1012 unidades formadoras de colônia (UFC) e por determinação da concentração bactericida mínima (CBM), usando inóculo de aproximadamente 106 UFC. Os agentes químicos também foram avaliados sobre Enterococcus faecalis (E. faecalis) ATCC 29212 cultivada em matriz de dentina (ex vivo) visando a formação de biofilme. O biofilme (organismos sésseis) microbiano foi removido com limas tipo Kerr (LK), até as lâminas estarem visualmente preenchidas. As LK contaminadas foram usadas como carreadores (logo após a contaminação ou secas dentro de uma câmara de fluxo laminar por 10 minutos). As LK carreadoras foram imersas em álcool isopropílico ou acetona ambos a 80%, ou em Ácido peracético 2%, por 30 ou 60 segundos. As limas foram posteriormente colocadas em tubos de ensaio contendo caldo Enterococcosel para observar o crescimento dos enterococos viáveis. Depois, os experimentos in vivo foram realizados com LK contaminadas por material necrótico pulpar da região cervical de dentes indicados para tratamento endodôntico. As LK contaminadas foram imersas, por 30 ou 60 segundos, em 80% de acetona ou 80% de álcool isopropílico ou 2% de PAA. As limas foram então inoculadas em tubos de ensaio contendo meio tioglicolato. Os organismos que cresceram, foram identificados após o tratamento com PAA. A corrosão mediada pelos agentes químicos também foi testada, após a incubação de LK de aço inoxidável e de NiTi por 60 minutos, medindo o peso das LK antes e depois da imersão e por microscopia eletrônica de varredura (MEV). Todos os agentes ...

This investigation aimed to evaluate the antimicrobial efficacy of disinfectant agents used to maintain the disinfection of endodontic instruments during the transoperatory period in endodontic treatment. The antimicrobial activity of disinfectants isopropyl alcohol, acetone and peracetic acid were evaluated upon planktonic micro-organisms by time kill assay (contact test) using inoculums from 9,9 X 109 to 1,2 X 1012 colony forming units (CFU) and determination of minimal bactericidal concentration (MBC), using inoculums of 106 CFU. Chemical agents were also evaluated upon Enterococcus faecalis (E. faecalis) ATCC 29212 strain grown on matrix dentin (ex vivo) for biofilm formation. Biofilm (sessile organisms) were removed with Kerr files until the blades were visually filled and contaminated K files used as carriers (shortly after contamination or dried inside a flow chamber for 10 minutes). K files carriers were immersed in 80% isopropyl alcohol, 80% acetone or in 2% peracetic acid for 30 or 60 seconds. The files were subsequently dispensed into test tubes containing Enterococcosel broth to observe the growth of viable enterococci. Thereafter, in vivo experiments were performed with K files contaminated with pulp necrotic material from cervical region of teeth indicated to endodontic treatment. The contaminated K files were immersed for 30 or 60 seconds in 80% acetone, 80% isopropyl alcohol and 2% peracetic acid. The files were then inoculated into test tubes containing tioglycolate medium. The organisms that grew after peracetic acid treatment were identified. The corrosion mediated by the chemical agents was also tested after incubation of stainless steel and NiTi K files for 60 minutes, by measuring the weight of K-files before and after immersion, and by scanning electron microscopy (SEM). All chemical agents were capable to eliminate or reduce bacterial viability of planktonic Gram-negative and Gram-positive species, though the activity ...

Acetona exalada como novo biomarcador do diagnóstico de insuficiência cardíaca / Exhaled breath acetone as a new biomarker of heart failure diagnosis

A insuficiência cardíaca é uma síndrome clínica de alta morbimortalidade e por este motivo é crescente o interesse em se estudar novos biomarcadores da doença visando buscar caminhos para novas estratégias terapêuticas. Neste contexto, a análise do ar exalado pode ser promissora. Baseado nestes dados e na observação de que pacientes com insuficiência cardíaca grave exalam odor peculiar, ainda em estudo piloto, nós identificamos acetona no ar exalado de pacientes com insuficiência cardíaca. Assim, nosso estudo teve por objetivo primário avaliar o papel da acetona exalada como biomarcador do diagnóstico de insuficiência cardíaca e de insuficiência cardíaca descompensada. Como objetivo secundário, avaliar sua relação com a classe funcional segundo a classificação da New York Heart Assocation (NYHA) e sua correlação com o peptídeo natriurético do tipo B (BNP). Entre maio de 2009 e setembro de 2010, pacientes consecutivos com disfunção sistólica (grupo IC) admitidos na emergência (insuficiência cardíaca descompensada grupo ICDESCOMP) e pacientes estáveis nos últimos três meses encaminhados para o teste cardiopulmonar (insuficiência cardíaca compensada grupo ICCOMP) foram submetidos à coleta de ar exalado (extração em água) para posterior análise qualitativa por cromatografia gasosa acoplado à espectrometria de massas e quantificação por espectrofotometria de absorção, através da reação com salicilaldeído. Entre os 235 pacientes avaliados, 89 foram incluídos (59 com insuficiência cardíaca descompensada e 30 com insuficiência cardíaca compensada), 61% do sexo masculino e com mediana de idade de 52 anos. Vinte indivíduos saudáveis (grupo controle) pareados por idade participaram do estudo. O valor mediano (intervalo interquartil) de acetona exalada foi maior no grupo IC em relação ao controle [3,70 g/L (1,69-10,45 g/L) versus 0,39 g/L (0,30-0,79 g/L), p < 0,001]. O valor mediano de acetona em pacientes com insuficiência cardíaca descompensada foi maior do que...

Heart failure (HF) is a condition associated with high mortality and frequent hospital admissions. In this context, multiple biomarkers of heart failure severity have emerged recently. However, the usefulness of most of these biomarkers has not been fully established. Exhaled breath has been considered a suitable tool (biomarker) to evaluate different diseases. Based on the clinical observation that patients with acute decompensated heart failure (ADHF) exhale a distinct odor, in a pilot study we have identified acetone in exhaled breath of heart failure patients and this study aimed to evaluate the role of acetone as a new biomarker of heart failure and ADHF disease. As secondary aims, we intended to analyze the relation to New York Heart Association (NYHA) class and the correlation with B-Type Natriuretic Peptide (BNP). Patients with systolic dysfunction (HF group) admitted consecutively at the emergency room (ADHF group) and stable patients referred to the cardiopulmonary test (chronic HF CHF group) between May 2009 and September 2010 were submitted to exhaled breath collection (extraction into water). Acetone identification was done by gas chromatography-mass spectrometry (GC-MS) and its determination by absorption spectrophotometry after reaction with salicylaldehyde. Twenty healthy subjects matched for age were enrolled (control group). Among 235 patients with HF, 89 were included in the study (59 ADHF and 30 CHF), 61% male, with median age of 52 years. Median exhaled breath acetone value (interquartile range) was higher in the HF group when compared to control group [3.7 g/L (1.69-10.45 g/L) versus 0.39 g/L (0.30-0.79 g/L), p < 0.001] and also higher in ADHF when compared to CHF group [7.80 g/L (3.60-15.20 g/L) versus 1.22 g/L (0.682.19 g/L), p < 0,001]. The accuracy of the method to diagnose CHF (Acetone > 1.16 g/L; AUC = 0.94) and ADHF (Acetone > 2.5 g/L; AUC = 0.93) was similar to the accuracy of BNP (BNP > 42 pg/mL; AUC = 0.97 and BNP > 424 pg/mL...

Avaliação da eficácia da desinfecção de instrumentos usados durante o período transoperatório do tratamento endodôntico / Evaluation of the desinfection efficacy of instruments used during the transoperatory period in endodontic treatment

Esta investigação objetivou a eficácia antimicrobiana de agentes desinfetantes utilizados na desinfecção dos instrumentos endodônticos, durante o período transoperatório do tratamento endodôntico. A atividade antimicrobiana dos desinfetantes álcool isopropílico, acetona e ácido peracético (PAA) foi avaliada sobre microrganismos planctônicos através de teste de contato (time kill assay), utilizando inóculo de 9,9 X 109 a 1,2 X 1012 unidades formadoras de colônia (UFC) e por determinação da concentração bactericida mínima (CBM), usando inóculo de aproximadamente 106 UFC. Os agentes químicos também foram avaliados sobre Enterococcus faecalis (E. faecalis) ATCC 29212 cultivada em matriz de dentina (ex vivo) visando a formação de biofilme. O biofilme (organismos sésseis) microbiano foi removido com limas tipo Kerr (LK), até as lâminas estarem visualmente preenchidas. As LK contaminadas foram usadas como carreadores (logo após a contaminação ou secas dentro de uma câmara de fluxo laminar por 10 minutos). As LK carreadoras foram imersas em álcool isopropílico ou acetona ambos a 80%, ou em Ácido peracético 2%, por 30 ou 60 segundos. As limas foram posteriormente colocadas em tubos de ensaio contendo caldo Enterococcosel para observar o crescimento dos enterococos viáveis. Depois, os experimentos in vivo foram realizados com LK contaminadas por material necrótico pulpar da região cervical de dentes indicados para tratamento endodôntico. As LK contaminadas foram imersas, por 30 ou 60 segundos, em 80% de acetona ou 80% de álcool isopropílico ou 2% de PAA. As limas foram então inoculadas em tubos de ensaio contendo meio tioglicolato. Os organismos que cresceram, foram identificados após o tratamento com PAA. A corrosão mediada pelos agentes químicos também foi testada, após a incubação de LK de aço inoxidável e de NiTi por 60 minutos, medindo o peso das LK antes e depois da imersão e por microscopia eletrônica de varredura (MEV). Todos os agentes ...

This investigation aimed to evaluate the antimicrobial efficacy of disinfectant agents used to maintain the disinfection of endodontic instruments during the transoperatory period in endodontic treatment. The antimicrobial activity of disinfectants isopropyl alcohol, acetone and peracetic acid were evaluated upon planktonic micro-organisms by time kill assay (contact test) using inoculums from 9,9 X 109 to 1,2 X 1012 colony forming units (CFU) and determination of minimal bactericidal concentration (MBC), using inoculums of 106 CFU. Chemical agents were also evaluated upon Enterococcus faecalis (E. faecalis) ATCC 29212 strain grown on matrix dentin (ex vivo) for biofilm formation. Biofilm (sessile organisms) were removed with Kerr files until the blades were visually filled and contaminated K files used as carriers (shortly after contamination or dried inside a flow chamber for 10 minutes). K files carriers were immersed in 80% isopropyl alcohol, 80% acetone or in 2% peracetic acid for 30 or 60 seconds. The files were subsequently dispensed into test tubes containing Enterococcosel broth to observe the growth of viable enterococci. Thereafter, in vivo experiments were performed with K files contaminated with pulp necrotic material from cervical region of teeth indicated to endodontic treatment. The contaminated K files were immersed for 30 or 60 seconds in 80% acetone, 80% isopropyl alcohol and 2% peracetic acid. The files were then inoculated into test tubes containing tioglycolate medium. The organisms that grew after peracetic acid treatment were identified. The corrosion mediated by the chemical agents was also tested after incubation of stainless steel and NiTi K files for 60 minutes, by measuring the weight of K-files before and after immersion, and by scanning electron microscopy (SEM). All chemical agents were capable to eliminate or reduce bacterial viability of planktonic Gram-negative and Gram-positive species, though the activity ...

Comparación Histológica e Inmunohistoquimica de Muestras de Tejido Procesadas por la Técnica Convencional o por el Método Simplificado de Acetonas / Histological and Immunohistochemical Comparison of Tissue Samples Processed by the Conventional Technique or the Acetone Simplified Method

La técnica convencional (TC) que usa alcohol como agente deshidratante, es un método útil en los laboratorios de Histología y Anatomía Patológica. Recientemente, un nuevo método simplificado con acetona (TA) fué diseñado en un intento por reducir el tiempo de procesamiento de los tejidos (de 12 a 4 horas), el costo de reactivos, y como un factor importante para tener un diagnóstico veraz y rápido. En este trabajo se compararon los parámetros histológicos e inmunohistoquímicos en muestras de cáncer de mama, colon y riñón tratadas con ambos métodos. Los cortes fueron teñidos con H & E o tricrómico de Masson. También se llevó a cabo inmunohistoquímica con anticuerpos especificos para la identificación de citoqueratinas AE1/AE3, el receptor de estrógeno y receptor de progesterona. Se realizó un estudio ciego por tres especialistas en morfológía, quienes evaluaron la tinción nuclear, tinción del citoplasma y friabilidad o cambios en la estructura tisular. La especificidad y sensibilidad de la unión de los anticuerpos también fueron evaluadas. Los valores obtenidos para cada parámetro se analizaron estadísticamente con la prueba t de Student. Nuestros resultados muestran que los métodos de TC y TA no modificaron características histológicas como el patrón de tinción, ni se detectaron cambios tisulares. La positividad de la inmunohistoquímica fué similar para ambos métodos. No se observó diferencia estadística entre TC y TA. Nuestros resultados sugieren que la aplicación de la TA no modificó las propiedades histológicas e inmunohistoquímicas y que podría ser un método útil en el análisis morfológico.

The conventional technique (CT) using alcohol as a drying agent, is a useful method of histology and pathology in the laboratory. Recently, a new simplified method with acetone (TA) was designed in an attempt to reduce the processing time of the tissues (12 to 4 hours), the cost of reagents, and as an important factor to have an accurate and prompt diagnosis . This study compared the histological and immunohistochemical parameters in breast cancer, colon and kidney specimens treated with both methods. The sections were stained with H & E or Masson trichrome. Immunohistochemistry study with antibodies specific for the identification of cytokeratin AE1/AE3, the estrogen receptor and progesterone receptor was also carried out. Blind study was conducted by three specialists in morphology, who evaluated the nuclear staining, staining of the cytoplasm and friability or changes in tissue structure. The specificity and sensitivity of antibody binding were also evaluated. The values obtained for each parameter were statistically analyzed with Student t test. Our results show that the methods of CT and TA did not alter histological features as the pattern of staining, and tissue changes were detected. Immunohistochemical positivity was similar for both methods. There was no statistical difference between TC and TA. Our results suggest that implementation of the TA did not alter the histological and immunohistochemical properties and could be a useful method for morphological analysis.

Characterization of a novel lipase from Bacillus sp. isolated from tannery wastes

Kinetics of a lipase isolated from Bacillus sp. was studied. The enzyme showed maximum activity at pH 9 and temperature 60ºC. The Michaelis constant (K M 0.31 µM) obtained from three different plots i.e., Lineweaver-Burk, Hanes-Wolf and Hofstee, was found to be lower than already reported lipases that confirmed higher affinity of the enzyme for its substrate p-NPL (p-nitrophenyl laurate). Vmax of the enzyme was found to be 7.6 µM/mL/min. Energy of activation calculated from Arrhenius plot was found to be 20.607 kJmol-1. Activation enthalpy (ΔH*) had negative trend and the value for the hydrolysis of p-NPL by the enzyme at optimum temperature was -2.748 kJmol-1 . Activation entropy (ΔS*) and free energy of activation (ΔG*) of the enzyme were found to be 1.468 Jmol-1K-1 and -3.237 kJmol-1, respectively at optimum temperature. Low value of Q10 (0.04788) shows high catalytic activity of the enzyme. Mn2+, Fe2+ and Mg2+ enhanced the lipase activity whereas Cu2+, Na+ and Co2+ inhibited the enzyme activity. However, the enzyme activity was not affected significantly by K+ ions. EDTA and SDS also significantly inhibited the lipase activity. Activity of the enzyme was increased in n-hexane while decreased with increase in concentration of acetone, chloroform, ethanol and isopropanol.

Three-year clinical performance of composite restorations placed by undergraduate dental students

This retrospective study evaluated the clinical performance and the reasons for failure of anterior and posterior composite restorations placed by undergraduate dental students over a 3-year period. All cavities were restored using Prime & Bond 2.1 and TPH (Dentsply), according to the manufacturer's indications. One hundred and two patients who had received composite restorations by third and forth year undergraduate students were recalled and examined to analyze the quality of the restorations. The restorations were evaluated using the modified USPHS system. Two hundred and fifty-six composite restorations, 170 in anterior teeth and 86 in posterior teeth, were evaluated. Eighty-five percent of the restorations were considered satisfactory after 3 years. Class II and class IV restorations presented the highest prevalence of failure. Loss of the restoration and deficient marginal adaptation were the main causes of failure. No restoration failed due to secondary caries. Most restorations placed by dental students were considered satisfactory after long-term evaluation. Failure was more prevalent in larger restorations and was not associated with secondary caries.

Este estudo retrospectivo avaliou o comportamento clínico e as razões de falhas de restaurações de resina composta em dentes anteriores e posteriores, realizadas por alunos de graduação em odontologia, após 3 anos de acompanhamento. Cento e dois pacientes que tiveram restaurações de resina composta colocadas por alunos do terceiro ou quarto ano foram rechamados e examinados para analisar a qualidade das restaurações. Todas as cavidades foram restauradas utilizando Prime & Bond 2.1 e TPH (Dentsply), de acordo com as orientações do fabricante. As restaurações foram avaliadas utilizando o sistema USPHS modificado. Duzentas e cinquenta e seis restaurações de resina composta, 170 em dentes anteriores e 86 em posteriores foram avaliadas. Destas restaurações, 85 por cento foram consideradas satisfatórias após 3 anos. Cavidades de classe II e classe IV apresentaram maior prevalência de falhas. Perda de restaurações e adaptação marginal deficiente foram as maiores causas de falhas. Nenhuma restauração falhou em decorrência de cárie secundária. Em conclusão, restaurações de resina composta feitas por estudantes de odontologia foram na sua maioria consideradas satisfatórias após 3 anos. Falhas das restaurações foram mais prevalentes em restaurações maiores e não esteve associada com cárie secundária.

Antimicrobial efficacy of fruit extracts of two piper species against selected bacterial and oral fungal pathogens

Aim: To assess the antimicrobial efficacy of five solvent extracts of two Piper species commonly used in diet and traditional medicine, P. cubeba and P. longum, against selected bacterial and oral fungal pathogens i.e. Streptococcus mutans, Staphylococcus aureus, Candida albicans and Saccharomyces cerevisiae. Methods: The antimicrobial activity of five extracts of cubeb berries and Indian long pepper fruits was determined by the agar well diffusion method. The minimum inhibitory concentration (MIC) for the acetonic, methanolic and ethanolic extracts was determined by the modified agar well diffusion method. Results: Of the 5 fruit extracts evaluated, acetone, ethanol and methanol extracts of both the Piper spp. were found to have variable antimicrobial activities against all the four oral pathogens. The acetonic fruit extract of P. cubeba was the most effective against both the yeasts with the highest zone of inhibition (15.31 mm) against C. albicans followed by the methanolic (12.31 mm) and ethanolic (11.94 mm) extracts. C. albicans was found to be most sensitive pathogen, which survived up to 6.25 mg/mL in the acetonic extract (MIC = 12.5 mg/mL) followed by the methanolic and ethanolic extracts (MIC = 25 mg/mL). The acetonic, methanolic and ethanolic extracts of P. longum fruits showed almost equal inhibition zones of both yeasts, ranging between 10.64 and 14 mm. C. albicans survived up to 12.5 mg/mL (MIC= 25 mg/mL) while S.cerevisiae survived up to 25 mg/mL (MIC = 50 mg/mL). Conclusions: The crude extracts obtained from the fruits of the two Piper spp. may be used to treat oral fungal species, especially C. albicans, as they produced larger inhibition zones than antifungal drugs often used to treat these pathogens.

Evaluating the bonding of two adhesive systems to enamel submitted to whitening dentifrices

The aim of this study was to evaluate by micro-shear bond strength test, the bond strength of composite resin restoration to enamel submitted to whitening dentifrices. Forty bovine teeth were embedded in polystyrene resin and polished. The specimens were randomly divided into eight groups (n= 5), according to the dentifrice (carbamide peroxide, hydrogen peroxide and conventional dentifrice) and the adhesive system (Prime & Bond 2.1 and Adper Single Bond 2). Dentifrice was applied for 15 minutes a day, for 21 days. Thirty minutes after the last exposure to dentifrice, the samples were submitted to a bonding procedure with the respective adhesive system. After that, four buttons of resin were bonded in each sample using transparent cylindrical molds. After 24 hours, the teeth were submitted to the micro-shear bond strength test and subsequent analysis of the fracture mode. Data were submitted to analysis of variance and Fisher's PLSD test (α=0.05). The micro-shear bond strength showed no difference between adhesives systems but a significant reduction was found between the control and carbamide groups (p=0.0145) and the control and hydrogen groups (p=0.0370). The evaluation of the failures modes showed that adhesive failures were predominant. Cohesive failures were predominant in group IV. The use of dentifrice with peroxides can decrease bonding strength in enamel.

O objetivo deste trabalho foi avaliar, pelo metodo de microcisalhamento, a resistencia adesiva obtida em restauracoes de resina composta realizadas sobre o esmalte dental previamente exposto a diferentes dentifricios. Para isso, quarenta dentes bovinos foram incluidos em resina de poliestireno e polidos. Os dentes foram divididos aleatoriamente em 8 grupos (n=5) de acordo com o dentifricio utilizado (cremes contendo peroxido de hidrogenio, peroxido de carbamida ou dentifricio convencional) e sistema adesivo (Prime & Bond 2.1 ou Adper single Bond 2). Os dentes foram expostos por 15 minutos por dia durante 21 dias as suspensoes dos respectivos cremes dentais. Trinta minutos apos a ultima exposicao ao dentifricio, os dentes foram restaurados empregando os 2 diferentes sistemas adesivos e resina composta. Apos 24 horas os dentes foram submetidos ao teste de microcisalhamento e posterior analise do padrao de fratura. Os resultados obtidos foram submetidos a analise de variancia e teste de Fisher's PLSD (α=0.05). Nao foi detectada diferenca estatistica entre os adesivos, porem entre os tratamentos com dentifricios, houve reducao estatisticamente significante entre os grupos controle x carbamida (p=0.0145) e entre o grupo controle x hidrogenio (p=0.0370). Na avaliacao do tipo de fratura houve predominancia de falhas adesivas, com excecao do grupo IV que apresentou maior fratura coesiva em esmalte. Assim, a utilizacao de cremes dentais, contendo peroxidos em suas formulacoes, pode provocar uma reducao na resistencia de uniao ao esmalte.

Estudio comparativo de dos técnicas de plastinación / Two different plastination techniques comparative study

La técnica de plastinación es utilizada ampliamente para la mejor preservación de las piezas cadavéricas utilizadas en docencia. Nuestra unidad la está utilizando desde el año 2002, pero hemos notado que la calidad de las muestras no es la óptima, produciéndose gran retracción de éstas. Por tal motivo, se diseñó una trabajo que compara la técnica de plastinación de nuestra unidad, con otro proceso, el cual se basa en el protocolo utilizado por la Universidad de Murcia. Utilizamos 24 muestras frescas de riñones y hemiencéfalos de vacuno, riñones y corazones de cerdo y miembro inferior humano, las cuales fueron fijadas con alcohol etílico, formalina y solución fijadora Universidad de los Andes. Fueron aplicadas dos diferentes técnicas de plastinación: una basada en el protocolo utilizado hasta ese momento en nuestro laboratorio de plastinación (técnica A) y otro proceso similar al publicado por la Universidad de Murcia (técnica B). Se evaluaron los porcentajes de variación de peso, ancho, largo, espesor y perímetro de las diferentes piezas plastinadas. También se procedió a fijar las muestras en diferentes soluciones (alcohol, formalina 10 por ciento y solucion fijadora Universidad de los Andes), pesar y medir sus dimensiones. El porcentaje de pérdida de peso promedio fue 63,1 por ciento para la técnica A y 37,9 por ciento para la técnica B (p<0,01); las mediciones de las disminuciones en el largo, ancho y grosor de las muestras también fueron mayores en las piezas sometidas a la técnica A, siendo todos los porcentajes de pérdidas estadísticamente significativos. Al comparar las muestras según los diferentes métodos de fijación con la técnica B no hubo diferencias estadísticamente significativas. La plastinación de muestras basadas en la técnica de Murcia obtiene muestras de mejor calidad y menos retracción. No influiría en el proceso de plastinación el método de fijación.

The plastination technique is used extensively for the improved preservation of cadavers used for teaching. Our unit has been using this technique since 2002, but we have noticed that sample quality is not optimal, given the large retraction of samples. Therefore, a project was designed that compares our department's plastination technique, with another process, based on the protocol used by Murcia University. We used 24 fresh bovine kidneys and brain samples, pigs' kidneys and hearts and human lower limbs; all of which were fixed with ethyl alcohol, formalin and De los Andes University's fixation solution. Two different plastination techniques were applied: one based on the protocol used in our laboratory (technique A) and another one similar to that published by Murcia University (technique B). We evaluated the body weight percentage, width, length, thickness and perimeter of the different plastinated pieces, as well as measuring the same variables in each fixation solution (alcohol, formalin fixative solution 10 percent and Universidad de los Andes). The average weight loss percentage was 63.1 percent for technique A and 37.9 percent for technique B (p <0.01). The decrease measurements in length, width and thickness were also higher under technique A, all percentages being statistically significant. When comparing the samples according to different fixation methods, there were no significant differences. Plastination based on Murcia University's technique obtained better quality samples with less shrinkage. The plastination process was not influenced by the fixation method.

Thermodynamic study of the solubility of ibuprofen in acetone and dichloromethane

Thermodynamic functions, Gibbs energy, enthalpy and entropy for the solution processes of ibuprofen (IBP) in acetone and dichloromethane (DCM) were calculated from solubility values obtained at temperatures ranging from 293.15 K to 313.15 K. The respective thermodynamic functions for mixing and solvation processes as well as the activity coefficients for the solute were calculated. IBP solubility was high and proved similar in both solvents but was greater in DCM than acetone. In addition, the thermodynamic quantities for the transfer process of this drug from cyclohexane to the organic solvents were also calculated in order to estimate the contributions of hydrogen-bonds or of other dipolar interactions. The results were discussed in terms of solute-solvent interactions.

As funções termodinâmicas, energia de Gibbs, entalpia e entropia dos processos de solução de ibuprofeno (IBP) em acetona e em diclorometano (DCM) foram calculadas a partir dos valores de solubilidade, obtidos em intervalos de temperatura de 293,15 K a 313,15 K. As funções termodinâmicas respectivas para os processos de mistura e solvatação e os coeficientes de atividade para o soluto também foram calculados. A solubilidade do IBP foi grande e semelhante em ambos os solventes, mas, maior em DCM do que em acetona. Em adição, as quantidades termodinâmicas relativas ao processo de transferência desse fármaco do cicloexano para os solventes orgânicos foram, também, calculadas com o objetivo de estimar as contribuições devidas às ligações de hidrogênio ou a outras interações dipolares. Os resultados foram discutidos nos termos das interações soluto-solvente.

Bonding agent underneath sealant: shear bond strength to oil-contaminated

This study evaluated in vitro the shear bond strength of a resin-based pit-and-fissure sealant (Fluroshield - F) associated with either an ethanol-based (Adper Single Bond 2 - SB) or an acetone-based (Prime & Bond - PB) adhesive system under conditions of oil contamination. Mesial and distal enamel surfaces from 30 sound third molars were randomly assigned to 2 groups (n=30): I - no oil contamination; II - oil contamination. Contamination (0.25 mL during 10 s) was performed after 37 percent phosphoric acid etching with an air/oil spray. The specimens were randomly assigned to subgroups, according to the bonding protocol adopted: subgroup A - F was applied to enamel without an intermediate bonding agent layer; In subgroups B and C, SB and PB, respectively, were applied, light-cured, and then F was applied and light-cured. Shear bond strength was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. Means (± SD) in MPa were: IA-11.28 (±1.84); IIA-12.02 (±1.15); IB-9.73 (±2.38); IIB-9.62 (±2.29); IC-28.30 (±1.63); and IIC-25.50 (±1.91). It may be concluded that the oil contamination affected negatively the sealant bonding to enamel and the acetone-based adhesive system (PB) layer applied underneath the sealant was able to prevent its deleterious effects to adhesion.

Este estudo avaliou in vitro a resistência ao cisalhamento (RC) de um selante resinoso [Fluroshield (F); Dentsply/Caulk] em associação com um sistema adesivo com solvente a base de etanol [Adper Single Bond 2 (SB); 3M/ESPE] ou a base de acetona [Prime & Bond (PB); 3M/ESPE] após contaminação com óleo do esmalte. Superfícies mesiais e distais de esmalte de 30 terceiros molares hígidos foram aleatoriamente alocadas em 2 grupos (n=30): I - contaminação com óleo; II - sem contaminação. A contaminação foi realizada (0,25 mL;10 s) com um jato de ar/óleo após o condicionamento do esmalte com ácido fosfórico a 37 por cento. Os espécimes foram aleatoriamente alocados em subgrupos, de acordo com a técnica adesiva empregada: A - F foi aplicado sobre o esmalte condicionado sem sistema adesivo; B - SB + F; C - PB + F. RC foi testada em uma máquina universal de ensaios (0,5 mm/min; 50 kgf) e os dados analisados por ANOVA e t-teste (α=0,01). As médias de RC em MPa foram: IA-11,28 (±1,84); IIA-12,02(±1,15); IB-9,73 (±2,38); IIB-9,62 (±2,29); IC-28,30 (±1.63); e IIC-25,50 (±1,91). Conclui-se que a contaminação com o óleo afetou a adesão do selante resinoso ao esmalte e o sistema adesivo com solvente a base de acetona (Prime & Bond) aplicado sob o selante foi capaz de impedir os efeitos deletérios da contaminação com óleo.

Toxicidade de aminoacetona e células produtoras de insulina / Cytotoxity of aminoacetone on insulin-producing cells

Danos induzidos por hiperglicemia em tecidos no diabetes são caracterizados por quatro mecanismos conectados: aumento do fluxo metabólico através da via do poliol, ativação da proteína quinase C (PKC), aumento da atividade da via das hexosaminas e aumento da produção intracelular dos precursores dos produtos finais de glicação avançada (AGEs). Entre eles, os derivados de metilglioxal, um potente agente de modificação de proteínas e DNA, têm sido associados a complicações microvasculares no diabetes: nefropatia, retinopatia e neuropatia. O metilglioxal é produzido a partir das trioses fosfato, acetona e aminoacetona, um catabólito de treonina e glicina, gerado na matriz mitocondrial. A aminoacetona sofre oxidação enzimática, catalisada por aminoxidase sensível a semicarbazida (SSAO), ou química, catalisada por íons de cobre e ferro, produzindo metilglioxal, H2O2 e NH4 +. Sabendo que metilglioxal e H2O2 são capazes de induzir apoptose e/ou necrose em células produtoras de insulina (RINm5f) propomos uma possível atividade pró-oxidante da aminoacetona sobre células beta do pâncreas. O tratamento destas linhagens com aminoacetona/Cu(II) aumentou a morte celular, fluxo de Ca2+ intracelular, produção de NO, fragmentação do DNA, depleção dos níveis de glutationa reduzida (GSH), expressão gênica da proteína apoptótica Bax, enzimas antioxidantes - glutationa peroxidase (GPx), glutationa redutase (GRd), catalase e isoformas de superóxido dismutases (CuZnSOD e MnSOD) - e óxido nítrico sintase induzida (iNOS). Embora as concentrações normais e patológicas da aminoacetona, provavelmente seja muito menores que as usadas nos experimentos, sugerimos que, em tecidos de diabéticos, um acúmulo da aminoacetona em longo prazo pode conduzir a danos oxidativos e eventualmente morte das células beta do pâncreas.

Tissue damages induced by hyperglycemia in diabetics are characterized by four linked mechanisms: increased flux through the polyol pathway, protein kinase C (PKC) activation, increased hexosamine pathway activity and intracellular production of advanced glycation end product (AGE) precursors. The production of AGEs by modifying proteins and DNA agent, such as methylglyoxal, has been implicated in microvascular complications in diabetes: nephropathy, retinopathy and neuropathy. Methylglyoxal is putatively produced in vivo from trioses phosphate, acetone and aminoacetone, a catabolite of threonine and glycine synthesized in the mitochondrial matrix. Aminoacetone has been reported to undergo semicarbazide sensitive amine oxidase- catalyzed and copper- and iron-catalyzed oxidations by molecular oxygen to methylglyoxal, NH4 + ion and H2O2. Considering that methylglyoxal and H2O2 have been found to promote apoptosis/necrosis to insulin-producing cells (RINm5f), we propose a possible pro-oxidant role of aminoacetone in pancreatic beta-cells. Treatment of RINm5f cells with aminoacetone plus Cu(II) ion promotes an increase of non-viable cells, influx of Ca2+ ions, NO production, DNA fragmentation, depletion of reduced glutathione (GSH) levels, and increased mRNA expression of pro-apoptotic protein (Bax), antioxidant enzymes - glutathione peroxidase (GPx), glutathione reductase (GRd), MnSOD, CuZnSOD and catalase - and inducible nitric oxide synthase (iNOS). Although both normal and pathological concentrations of aminoacetone are probably much lower than those used here, it is tempting to propose that excess aminoacetone in diabetic patients, at long term, may drive oxidative damage and eventually death of pancreatic beta-cells.