Estudo in vivo do comportamento de bioprótese liofilizada: seguimento de 3 meses em carneiros jovens / In vivo study of lyophilized bioprostheses: 3 month follow-up in young sheep

OBJETIVO: Para melhorar as propriedades mecânicas e imunogênicas, o glutaraldeído é utilizado no tratamento do pericárdio bovino que é utilizado em biopróteses. A liofilização do pericárdio bovino tratado com glutaraldeído diminui os radicais aldeído, com provável redução do potencial para calcificação. O objetivo deste estudo é avaliar os efeitos da liofilização em biopróteses valvares de pericárdio bovino como mecanismo protetor na diminuição da disfunção estrutural valvar. MÉTODOS: Foi realizado o implante de biopróteses de pericárdio bovino tratado com glutaraldeído, liofilizadas ou não, em carneiros de 6 meses de idade, sendo os animais eutanasiados com 3 meses de seguimento. As biopróteses foram implantadas em posição pulmonar, com auxílio de circulação extracorpórea. Um grupo controle e outro grupo liofilizado foram avaliados quanto ao gradiente ventrículo direito/artéria pulmonar (VD/AP) no implante e explante; análise quantitativa de cálcio; inflamação; trombose e pannus. O nível de significância estabelecido foi de 5%. RESULTADOS: O gradiente médio VD/AP, no grupo controle, no implante, foi 2,04 ± 1,56 mmHg e, no grupo de liofilização, foi 6,61 ± 4,03 mmHg. No explante, esse gradiente aumentou para 7,71 ± 3,92 mmHg e 8,24 ± 6,2 mmHg, respectivamente, nos grupos controle e liofilização. O teor de cálcio médio, após 3 meses, nas biopróteses do grupo controle foi 21,6 ± 39,12 µg Ca+2/mg de peso seco, em comparação com um teor médio de 41,19 ± 46,85 µg Ca+2/mg de peso seco no grupo liofilizado (P = 0,662). CONCLUSÃO: A liofilização de próteses valvares com pericárdio bovino tratado com glutaraldeído não demonstrou diminuição da calcificação neste experimento.

OBJECTIVE: Glutaraldehyde is currently used in bovine pericardium bioprosthesis to improve mechanical and immunogenic properties. Lyophilization is a process that may decrease aldehyde residues in the glutaraldehyde treated pericardium decreasing cytotoxicity and enhancing resistance to calcification. The aim of this study is to evaluate bioprosthetic heart valves calcification in adolescent sheep and to study the potential of lyophilization as a mechanism to protect calcification. METHODS: Two groups were evaluated: a control group in which a bovine pericardium prosthetic valve was implanted in pulmonary position and a lyophilized group in which the bovine pericardium prosthetic valve was lyophilized and further implanted. Sixteen sheeps 6 months old were submitted to the operation procedure. After 3 months the sheeps were euthanized under full anesthesia. RESULTS: Six animals of the control group reached 95.16 ± 3.55 days and six animals in the lyophilized group reached 91.66 ± 0.81 days of postoperative evolution. Two animals had endocarditis. Right ventricle/pulmonary artery (RV/PA) mean gradient, in the control group, at the implantation was 2.04 ± 1.56 mmHg, in the lyophilization group, the RV/PA mean gradient, at the implantation was 6.61 ± 4.03 mmHg. At the explantation it increased to 7.71 ± 3.92 mmHg and 8.24 ± 6.25 mmHg, respectively, in control and lyophilization group. The average calcium content, after 3 months, in the control group was 21.6 ± 39.12 µg Ca+2/mg dry weight, compared with an average content of 41.19 ± 46.85 µg Ca+2/mg dry weight in the lyophilization group (P=0.662). CONCLUSION: Freeze drying of the bovine pericardium prosthesis in the pulmonary position could not demonstrate calcification mitigation over a 3 month period although decreased inflammatory infiltration over the tissue.

Efeito da descelularização com SDS na prevenção da calcificação em pericárdio bovino fixado em glutaraldeído: estudo em ratos / Effect of SDS-based decelullarization in the prevention of calcification in glutaraldehyde-preserved bovine pericardium: study in rats

OBJETIVO: Avaliar a descelularização com SDS como tratamento anticalcificante em pericárdio bovino fixado em glutaraldeído. MÉTODOS: Peças de 0,5 cm² foram implantadas em modelo subcutâneo de 18 ratos por até 90 dias. Foram formados quatro grupos: grupo GDA: pericárdio fixado em glutaraldeído 0,5% (GDA), grupo GDA-GL: pericárdio fixado em GDA + ácido glutâmico (GL) 0,2%, grupo D-GDA: pericárdio descelularizado (D) com SDS 0,1% e fixado em GDA e grupo D-GDA-GL: pericárdio descelularizado + GDA + ácido glutâmico 0,2%. Cada animal recebeu enxertos dos quatro grupos. Os explantes foram realizados com 45 e 90 dias. As avaliações foram: análise histológica com as colorações hematoxilina-eosina e alizarina-red, análise morfométrica e quantificação de cálcio por espectrometria de absorção atômica. RESULTADOS: O padrão de infiltrado inflamatório foi o mesmo nos quatro grupos, sendo mais intenso nos grupos GDA e GDA-GL aos 45 dias, ficando mais evidente aos 90 dias. O conteúdo de cálcio aos 45 dias foi de 32,52 ± 3,19 µg/ mg no grupo GDA; 22,12 ± 3,87 µg/mg no grupo GDA-GL; 1,06 ± 0,38 µg/mg no grupo D-GDA e 3,99 ± 5,78 µg/mg no grupo D-GDA-GL (P< 0,001). Aos 90 dias, foi de 65,91 ± 24,67 µg/mg no grupo GDA; 38,37 ± 13,79 µg/mg no grupo GDA-GL; 1,24 ± 0,99 µg/mg no grupo D-GDA e 30,54 ± 8,21 µg/mg no grupo D-GDA-GL (P< 0,001). O grupo D-GDA foi o único que não apresentou progressão da calcificação de 45 para 90 dias (P=0,314). CONCLUSÃO: A descelularização com SDS reduziu o processo inflamatório e inibiu a calcificação em pericárdio bovino implantado em modelo subcutâneo de ratos até 90 dias.

OBJECTIVE: The aim of study was to investigate the SDS-based decellularization process as an anticalcification method in glutaraldehyde-preserved bovine pericardium in subcutaneous rat model. METHODS: Pericardium samples with 0.5 cm² area were divide in four groups: group GDA: 0.5% glutaraldehydepreserved pericardium (GDA); group GDA-GL: GDA + 0.2% glutamic acid (GL); group D-GDA: decellularized (D) pericardium with 0.1% SDS + GDA and group D-GDA-GL: decellularized pericardium + GDA + 0.2% glutamic acid. After this samples were implanted in 18 rats in subcutaneous position till 90 days. Each animal received samples of the four groups. The explants were performed at 45 and 90 days. The explants were subjected to histology in glass slides stained with hematoxilin-eosin and alizarin red, morphometry evaluation and the calcium content was measured by flame atomic absorption spectrometry. RESULTS: The inflammatory infiltrate was the same in all groups, however more intense in GDA and GDA-GL groups in 45 days, increasing at 90 days. The calcium contents for 45 days were: 32.52 ± 3.19 µg/mg in GDA group; 22.12 ± 3.87 µg/ mg in GDA-GL group; 1.06 ± 0.38 µg/mg in D-GDA group and 3.99 ± 5.78 µg/mg in D-GDA-GL (P< 0.001). For 90 days were 65.91 ± 24.67 µg/mg in GDA group; 38.37 ± 13.79 µg/mg in GDA-GL group; 1.24 ± 0.99 µg/mg in D-GDA group and 30.54 ± 8.21 µg/mg in D-GDA-GL (P< 0.001). Only D-GDA did not show increase rates of calcium at 45 to 90 days (P=0.314). CONCLUSION: SDS-based decellularization process reduced the inflammatory intensity and calcification in bovine pericardium in subcutaneous rat model for 90 days.

Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1 percent sodium hypochlorite, 2 percent sodium hypochlorite, 5.25 percent sodium hypochlorite, 2 percent glutaraldehyde, and 4 percent chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5 percent. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

In vitro dentin permeability after application of Gluma® desensitizer as aqueous solution or aqueous fumed silica dispersion

OBJECTIVES: To assess and to compare the effects of Gluma® Desensitizer (GDL) with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG) on dentin permeability using a chemiluminous tracer penetration test. MATERIAL AND METHODS: Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM) for surface remnants. RESULTS: Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values refected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were signifcantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not signifcantly different. Treated specimens showed no surface remnants after rinsing. CONCLUSIONS: The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution.

Análise do comportamento hemodinâmico de conduto valvado de pericárdio bovino, implantado em posição aórtica de ovinos / Analysis of hemodynamic performance of the bovine pericardium valved conduit, implanted in the aortic position in ovines

OBJETIVOS: A necessidade de substituição da valva, aorta ascendente e reimplante coronariano em pacientes onde a anticoagulação é indesejável, é crescente. Avaliamos em animais o comportamento hemodinâmico de um conduto valvado aórtico feito com pericárdio bovino tratado pelo glutaraldeído (CVAP). MÉTODOS: Para isto, implantamos CVAPs em oito ovinos e os explantamos após 150 dias de pós-operatório. Realizouse estudo angiográfico e hemodinâmico no pré-operatório e antes do explante. EcoDopplercardiogramas foram realizados nos dias 30 e 150 de pós-operatório (teste) e também em cinco ovinos não operados. Após explantados, submetemos os CVAPs à avaliação macroscópica, radiológica e histológica por microscopia óptica. RESULTADOS: Na análise hemodinâmica, as pressões arterial e capilar pulmonar aumentaram (P<0,05) entre os dias 0 e 150. Na análise ecoDopplercardiográfica, o grupo teste apresentou incremento dos diâmetros diastólicos e sistólicos do ventrículo esquerdo (P<0,05). O grupo teste entre os dias 30 e 150 aumentou: peso, espessura das paredes do ventrículo esquerdo, gradiente transvalvar máximo, gradiente transvalvar médio, diâmetro diastólico do ventrículo esquerdo e decréscimo da fração de ejeção (P<0,05). Dois animais com endocardite explicam essas diferenças, tal como demonstrado na análise estatística realizada sem a presença desses animais. A macroscopia demonstrou calcificação de grau variável. A microscopia óptica demonstrou similaridade com a literatura quanto ao uso do pericárdio bovino tratado pelo glutaraldeído. CONCLUSÕES: Estes dados indicam que o CVAP permite a realização desse tipo de experimento no modelo proposto e que os resultados hemodinâmicos encontrados se assemelham aos parâmetros fisiológicos.

OBJECTIVE: The necessity for replacement of the valve, ascending aorta and aortic with coronary reimplantation in patients where anti-coagulation is undesirable, is increasing. We evaluated the hemodynamic performance of an aortic valved conduit made with glutaraldehyde treated bovine pericardium (AVCP) in animals. METHODS: Therefore, AVCPs were implanted in eight young ovine and explanted after 150 days. Angiographic and hemodynamic study was performed at pre-operative and prior the explant. EchoDopplercardiograms were performed at day 30 and 150 of post-operative (test) and also in five nonoperated ovines. After explanted, AVCPs were submitted to a macroscopical, radiological and histological evaluation by optic microscopy. RESULTS: In the hemodynamic analysis the arterial and pulmonary capillary pressure increased (P<0.05) between day 0 and 150. In the echoDoppercardiographic analysis, the test group presented higher values in the diastolic and systolic diameters of the left ventricle (P<0.05). In the test group, between day 30 and 150, occurred an increase of weight, thickness of the left ventricle walls, maximum transvalvar gradient, medium transvalvar gradient, left ventricle diastolic diameter and a decrease in the ejection function (P<0.05). Two animals with endocarditis explain those differences, how we can see with the statistycal analysis without this sample. Macroscopy showed calcification in variable degrees. Optic microscopy revealed data similar to literature with the use of glutaraldehyde treated bovine pericadium. CONCLUSIONS: These data indicate that the AVCPs allows the performance of this kind of experiment in the proposed model and that the hemodynamic outcomes found are similar to physiological parameters.

Mycobacterium massiliense BRA100 strain recovered from postsurgical infections: resistance to high concentrations of glutaraldehyde and alternative solutions for high level disinfection / Mycobacterium massiliense clone BRA100 associado a infecções pós-cirúrgicas: resistência a altas concentrações de glutaraldeído e produtos alternativos para desinfecção de alto nível

PURPOSE: To evaluate the minimum inhibitory concentration (MIC) of GTA against these microorganisms and alternative disinfectants for high-level disinfection (HLD). METHODS: Reference mycobacteria and clinical M. massiliense strains were included in this study. Active cultures were submitted to susceptibility qualitative tests with GTA dilutions (ranging from 1.5 percent to 8 percent), and commercial orthophthaldehyde (OPA) and peracetic acid (PA) - based solutions, during the period of exposure as recommended by National Agency of Sanitary Surveillance for HLD. RESULTS: All reference and M. massiliense non-BRA100 strains, recovered from sputum, were susceptible to any GTA concentration, OPA and PA solutions. M. massiliense BRA100 strains presented MIC of 8 percent GTA and were susceptible to OPA and PA. CONCLUSION: M. massiliense BRA100 strain is resistant to high GTA concentrations (up to 7 percent), which proves that this product is non-effective against specific rapidly growing mycobacteria and should be substituted by OPA or PA - based solutions for HLD.

OBJETIVO: Avaliar a concentração mínima inibitória (CMI) de GTA frente a M. massiliense e a susceptibilidade a produtos alternativos para desinfecção de alto nível (DAN). MÉTODOS: Cepas de M. massiliense de origem clínica e de referência foram incluídas no estudo. As culturas ativadas foram submetidas a testes qualitativos com diluições de GTA (de 1,5 por cento a 8 por cento) e com soluções comerciais de ortoftaldeído (OPA) ou ácido peracético (PA), utilizando os tempos de exposição recomendados pela Agência Nacional de Vigilância Sanitária para DAN. RESULTADOS: Todas as cepas de referência e M. massiliense não-BRA100, obtida de escarro, foram susceptíveis às concentrações de GTA, e soluções de OPA e PA. As cepas de M. massiliense BRA100 apresentaram CMI de 8 por cento para GTA e foram susceptíveis a OPA e PA. CONCLUSÃO: M. massiliense BRA100 é resistente a altas concentrações de GTA (até 7 por cento), o que demonstra que esse composto não é eficaz, e deve ser substituído por OPA ou PA nos processos de DAN.

Endoscope reprocessing using glutaraldehyde in endoscopy services of Goiânia, Brazil / O reprocessamento de endoscópios pelo uso do glutaraldeído: a realidade em serviços de endoscopia de Goiânia, GO

CONTEXT: The endoscopic procedure safety depends on the use of an adequately reprocessed device which quality is related to each of its operational steps. OBJECTIVE: To characterize the reprocessing of endoscopes using glutaraldehyde in endoscopy services METHODS: Study was conducted by observing the reprocessing of 60 endoscopes from 20 medical practices of the municipality of Goiânia, GO, central area of Brazil. RESULTS: This study showed failure in all reprocessing steps. The pre-washing was performed in 24 (40.0 percent) of the endoscope. In the cleaning steps, was identify the improper use of enzymatic detergent, and in 27 (45.0 percent) cases, the brushing of internal channels was not performed. All 60 endoscopes were submitted to this disinfectant. However, for 33 (55.0 percent) of the cases the internal channels was not filled. The total immersion of endoscope in the glutaraldehyde was not performed in 39 (65.0 percent) cases. The recommended minimum total immersion time for exposure to 2 percent glutaraldehyde solution was followed only for 12 (20.0 percent) endoscopes. There was no filter for water treatment used in the rinse of most endoscopes 54 (90.0 percent) and to dry the internal channels only 6 (10.0 percent) of them used compressed air. Adequate storing conditions were identified. CONCLUSION: Considering the particularities of the endoscope and its reprocessing, it is imperative to establish protocols to ensure the quality of the disinfection and the prevention of cross-contamination.

CONTEXTO: A segurança do procedimento endoscópico depende do uso de um aparelho adequadamente reprocessado e a qualidade do reprocessamento está relacionada a cada uma das etapas operacionais desse processo. OBJETIVO: Caracterizar o reprocessamento de endoscópios pelo uso do glutaraldeído em serviços de endoscopia. MÉTODOS: Estudo conduzido em 20 serviços de endoscopia digestiva do município de Goiânia, GO. A amostra se constituiu de endoscópios utilizados para endoscopia digestiva alta. Os dados foram obtidos mediante observação direta de 60 reprocessamentos de endoscópios. Resultado - Foram observadas falhas em todas as etapas do reprocessamento. Em 24 (40,0 por cento) endoscópios foi realizada a pré-lavagem. Na etapa da limpeza, foi identificado o uso inadequado do detergente enzimático e em 27 (45,0 por cento) não foi realizada a escovação dos canais internos. Todos os 60 endoscópios foram submetidos ao desinfetante, entretanto para 33 (55,0 por cento) não foi aspirado o produto nos canais internos. O tempo de exposição ao glutaraldeído foi observado apenas para 12 (20 por cento) dos endoscópios. O enxágue de 54 (90,0 por cento) dos endoscópios ocorreu com o uso de água não-filtrada e, para a secagem dos canais internos, apenas 6 (10,0 por cento) utilizaram o ar comprimido. Foram identificadas condições adequadas para o armazenamento. CONCLUSÃO: Considerando as particularidades do reprocessamento dos endoscópios é imperativo estabelecer protocolos para assegurar a qualidade da desinfecção e a prevenção da contaminação cruzada.

Effect of inmersion desinfection with 0, 5 percent sodium hypochlorite and 2 percent glutaraldehyde on alginate and silicone: microbiology and SEM study / Efecto de la desinfección en inmersión con 0, 5 por ciento de hipoclorito sódico y glutaraldehído al 2 por ciento sobre alginato y silicona: estudio de la microbiología y SEM

The disinfection of dental impression materials has become an essential topic of universal concern, as it may be the first instance of microbial contamination during dental care. The purpose of this study is twofold: To determine the effectiveness of disinfection with 0.5 percent sodium hypochlorite and 2 percent glutaraldehyde solutions in irreversible hydrocolloid (alginate) and silicone impressions and to analyze the effect of disinfection on surface quality with a scanning electronic microscope. Atotal of 32 impressions (16 made of irreversible hydrocolloid and 16 made of silicone) were taken from maxillary dentate patients. Samples of 1cm2 (80 , irreversible hydrocolloid, 80 silicone) were obtained and distributed in ten groups: alginate in no disinfectant (control group 1, AL), alginate in 0.5 percent sodium hypochlorite (NaOCl) for 5 (AH5) and 10 minutes (AH10), alginate in 2 percent glutaraldehyde for 5 (AG5) and 10 minutes (AG10), silicone in no disinfectant (control group 2), silicone in 0.5 percent NaOCl for5 (SH5) and 10 minutes (SH10), and silicone in 2 percent glutaraldehyde for 5 (SG5) and 10 minutes (SG10). Each sample was divided into two segments (one for the microbiological and one for the SEM study). Microbiological samples were planted on blood agar, Mac Conkey agar, and Sabouraud agar, and identification was made by Gram´s stain. The samples were then processed by an SEM. Immersion in the 5 percent NaOCl and 2 percent glutaraldehyde for 10 minutes completely eliminated bacteria in the impressions, compared with the control group (P=0.000004). Immersion in 0.5 percent NaOCl and 2 percent glutaraldehyde for 5 and 10 minutes significantly inhibited bacterial growth in both the irreversible hydrocolloid and silicone impressions compared with control group (P<0.05). However, in the SEM study, immersion in both disinfectant solutions for 5 and 10 minutes did not significantly affect the surface quality of the irreversible hydrocolloid...

La desinfección de los materiales de impresión dental se ha convertido en un tema esencial, ya que puede ser el primer caso de contaminación microbiana durante la atención dental. El propósito de este estudio es doble: determinar la eficacia de la desinfección con hipoclorito sódico al 0,5 por ciento y 2 por ciento de glutaraldehído en soluciones de hidrocoloide irreversible (alginato) y las impresiones de silicona, para analizar el efecto de la desinfección en la calidad de la superficie con un microscopio electrónico de barrido. Un total de 32 impresiones (16 hechas de hidrocoloides irreversibles y 16 de silicona) superiores de pacientes dentados fueron estudiadas. Las muestras de 1cm2 (80, hidrocoloide irreversible, el 80 de silicona) fueron obtenidas y distribuidas en diez grupos: alginato sin desinfectante (grupo de control1, AL), alginato en el 0,5 por ciento de hipoclorito sódico (NaOCl) durante 5 (AH5) y 10 minutos (AH10), alginato en glutaraldehído al 2 por ciento durante 5 (GA5) y 10 minutos (AG10), silicona sin desinfectante (grupo de control 2), silicona en 0,5 por ciento de NaOCldurante 5 (SH5) y 10 minutos (SH10) y, en glutaraldehído al 2 por ciento durante 5 (SG5) y 10 minutos (SG10). Cada muestra se dividió en dos segmentos (uno para los análisis microbiológicos y uno para el estudio SEM). Las muestras microbiológicasse sembraron en agar sangre, agar MacConkey y agar Sabouraud, y la identificación se realizó por tinción de Gram. Las muestras fueron procesadas por un SEM. La inmersión en 5 por ciento NaOCl y 2 por ciento de glutaraldehído durante 10 minutos eliminó completamente las bacterias de las impresiones, en comparación con el grupo control (P = 0,000004). La inmersión en 0,5 por ciento de NaOCl y glutaraldehído al 2 por ciento durante 5 y 10 minutos, inhibió el crecimiento de bacterias, tanto en el hidrocoloide irreversible e impresiones de silicona en comparación con el grupo control (P <0,05). Sin embargo, en el estudio SEM...

Antimicrobial efficacy of chemical disinfectants on contaminated full metal crowns

Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1 percent and 2 percent sodium hypochlorite and 2 percent glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.

Restaurações protéticas provadas na cavidade bucal dos pacientes são fontes potenciais de infecção. Para evitar infecção cruzada, protocolos de controle de infecção devem ser estabelecidos no consultório e laboratório odontológicos. Este estudo avaliou a eficácia antimicrobiana de desinfetantes químicos em coroas metálicas contaminadas com microorganismos. Coroas totais fundidas com liga de Ni-Cr foram divididas em grupo controle (n=6) e 5 grupos experimentais (n=18). As coroas foram colocadas em balões de vidro e esterilizadas em autoclave. A suspensão microbiana de cada tipo de cepa (S. aureus, P. aeruginosa, S. mutans, E. faecalis e C. albicans) foi assepticamente adicionada a cada grupo experimental, e as coroas foram deixadas contaminar por 30 min. Os corpos-de-prova contaminados foram colocados em recipientes com os desinfetantes químicos (hipoclorito de sódio 1 por cento e 2 por cento e glutaraldeído) por 5, 10 e 15 min. A seguir, as coroas foram colocadas em tubos contendo diferentes meios de cultura e incubadas a 35ºC. Os corpos-de-prova do grupo controle foram contaminados, imersos em água destilada por 20 min e a seguir colocados em tubos de ensaio com meio de cultura Thioglycollate e incubados a 35ºC. A análise do crescimento microbiano foi realizada pelo exame visual qualitativo após 48 h, 7 e 12 dias. Houve crescimento microbiano apenas no grupo controle. No grupo experimental não foi observada turvação dos meios de cultura, independentemente das cepas e períodos de imersão. Conclui-se que todos desinfetantes químicos foram eficazes para prevenir o crescimento microbiano.

Infecções por micobactérias de crescimento rápido resistentes a desinfetantes: uma problemática nacional? / Infections by rapidly growing mycobacteria resistant to disinfectants: a national matter?

Rapidly growing mycobacteria (RGM) are opportunistic microorganisms and widely distributed into aqueous environment and soil. Human RGM infections are usually associated with contaminated solutions or medical instruments used during invasive procedures. RGM postsurgical infections have recently emerged in Brazil and have caused national alert, considering the risk factors and epidemiological aspects. This study aimed at analysing the main factors linked to the recent RGM outbreaks, with focus on the national epidemic of Mycobacterium massiliense infections related to the BRA100 strains resistant to 2 percent glutaraldehyde commercial solutions commonly used for preoperative high-level disinfection. Based on previous studies and laboratorial results of assays and colaborations, it has been observed that the cases have been associated with videolaparoscopy for different applications and elective esthetic procedures, such as lipoaspiration and mammary prosthesis implant. Furthermore, outbreaks between 2004 and 2008 and the epidemic in Rio de Janeiro state may be considered particular Brazilian events. Although there are a few epidemiological published studies, some hypotheses based on common aspects related to most national nosocomial occurrences are possible, such as lack of protocols for cleaning and high-level disinfection, use of 2 percent glutaraldehyde as high-level disinfectant for surgical instruments, and dissemination of M. massiliense BRA100 by unknown mechanisms.

Infecção por micobactérias de crescimento rápido após procedimentos videocirúrgicos: a hipótese do glutaraldeído / Rapidly growing mycobacteria infection after videosurgical procedures: the glutaraldehyde hypothesis

Between August 2006 and February 2007, in the state of Rio de Janeiro, Brazil, a massive outbreak of RGM infections after video laparoscopy was mainly associated to the recently described Mycobacterium massiliense species. All confirmed and probable cases reports described the use of high-level disinfection of medical devices by using 2 percent glutaraldehyde (2 percent GA) for 30 min before the surgical procedures. We investigated the susceptibility of the M. massiliense isolates recovered during the outbreak to high-level disinfection after 30 min, 1h, 6h and 10h of exposure to the commercial disinfectants. Reference strains for official mycobactericidal tests such as Mycobacterium abscessus, Mycobacterium bovis, Mycobacterium chelonae, Mycobacterium neoaurum and Mycobacterium smegmatis were included as controls. Although all the reference strains were eliminated in 30 min of exposure to 2 percent GA, we observed the recovery of all M. massiliense clinical isolates even after 10h of exposure. This study suggests that failures in high-level disinfection and the high tolerance of these M. massiliense clinical strains to the 2 percent GA were strongly associated to the magnitude of the outbreak.

Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin.

AIM: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. MATERIALS AND METHODS: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250) cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM). RESULTS: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. CONCLUSION: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

The effect of 0.5% sodium hypochlorite and 2% glutaraldehyde spray disenfectants on irreversible hydrocolloid impression material.

Infection control has assumed prime importance in dentistry. It is a prime concern in prosthodontics as well, where impressions materials are most commonly used. Impression materials can act as a medium for cross infection. To prevent cross infection many products are being developed. Among them 0.5% Sodium hypochlorite and 2% Glutaraldehyde are considered effective. This study was done to asses the efficacy of 0.5% Sodium hypochlorite and 2% Glutaraldehyde on irreversible hydrocolloid impression material. The result of the study indicated that they are effective against both Gram positive and Gram negative organisms and their use is recommended.

Efficiency of the glutaraldehyde test strip for monitoring the concentration of glutaraldehyde in reused solutions for disinfecting endoscopes.

BACKGROUND: Glutaraldehyde has been widely used for low-temperature disinfection of endoscopes. The current practice at Siriraj Hospital is to change the glutaraldehyde solution every 21 days or when the solution appears turbid. The disadvantages of this practice include inadequate disinfection of endoscopes if the concentration of glutaraldehyde in a reused solution is insufficient or wasted if the discarded solution is still active. OBJECTIVE: To determine the efficiency of a glutaraldehyde test strip (GTS) in monitoring the amount of glutaraldehyde in a reused solution for disinfecting endoscopes. METHOD: Reused glutaraldehyde solutions for disinfecting bronchoscopes, gastroscopes and colonoscopes were tested for the concentration of glutaraldehyde with a GTS thrice weekly for the first week and then every working day up to 56 days. If the GTS indicated a concentration of glutaraldehyde > or = 1.8 per cent after 21 days, 5 ml of the solution was taken to the laboratory to determine its mycobactericidal activity. RESULTS: All samples of the reused glutaraldehyde solution up to 56 days with a concentration of > or = 1.8 per cent glutaraldehyde on GTS from testings showed mycobactericidal activity. If the glutaraldehyde solution was reused for up to 28, 42 or 56 days, it could save 9,603; 22,813 and 29,415 baht per year respectively for the gastroscopy and colonoscopy units. The corresponding figures were -949; 2,726 and 4,564 baht per year for the bronchoscopy unit. It is estimated that up to 400,000 baht per year could be saved by adopting the strategy of GTS monitoring in all endoscopy units at Siriraj Hospital. CONCLUSION: The current strategy of discarding reused glutaraldehyde solution in the gastroscopy, colonoscopy and bronchoscopy units at Siriraj Hospital may be inappropriate since the reused solution is still mycobactericidal for up to 56 days.

Isolation of bovine plasma albumin by liquid chromatography and its polymerization for use in immunohematology

The aim of the method described here is to remove hemoglobin, the major contaminant in the bovine plasma obtained from slaughterhouses, by adding a mixture of 19 percent cold ethanol and 0.6 percent chloroform, followed by fibrinogen and globulin precipitation by the Cohn method and nonspecific hemagglutinin by thermocoagulation. The experimental volume of bovine plasma was 2,000 ml per batch. Final purification was performed by liquid chromatography using the ion-exchange gel DEAE-Sepharose FF. The bovine albumin thus obtained presented > or = 99 percent purity, a yield of 25.0 + or 1.2 g/l plasma and >71.5 percent recovery. N-acetyl-DL-tryptophan (0.04 mmol/g protein) and sodium caprylate (0.04 mmol/g protein) were used as stabilizers and the final concentration of albumin was adjusted to 22.0 percent (w/v), pH 7.2 to 7.3. Viral inactivation was performed by pasteurization for 10 h at 60 degres C. The bovine albumin for the hemagglutination tests used in immunohematology was submitted to chemical treatment with 0.06 percent (w/v) glutaraldehyde and 0.1 percent (w/v) formaldehyde at 37 degrees C for 12 h to obtain polymerization. A change in molecular distribution was observed after this treatment, with average contents of 56.0 percent monomers, 23.6 percent dimers, 12.2 percent trimers and 8.2 percent polymers. The tests performed demonstrated that this polymerized albumin enhances the agglutination of Rho(D)-positive red cells by anti-Rho(D) serum, permitting and improving visualization of the results

Anatomia, histologia e ultra-estrutura do lobo ventral da próstata de ratos (Rattus norvegicus) vasectomizados / Anatomy, histology and ultrastructure of prostate ventral lobe of vasectomized (Rattus norvegicus)

A vasectomia é um método de contracepçäo amplamente utilizado, que tem sido associado ao carcinoma da próstata em estudos epidemiológicos. Contudo, poucos estudos morfológicos foram realizados sobre a possibilidade da vasectomia alterar a estrutura da próstata. Este trabalho apresenta uma revisäo de literatura que associa a vasectomia ao câncer da próstata, bem como resultados de estudo experimental em ratos. Dividiu-se um total de 48 ratos machos albinos (Rattus norvegicus), com 6 a 8 semanas de idade, em dois grupos : simulado e vasectomizado. Perfundiu-se, com glutaraldeído a 2,5 por cento, seis ratos de cada grupo após 60, 120, 180 e 360 dias pós-vasectomia. Coletou-se o lobo ventral da próstata para análise microscópica. No estudo ao microscópio de luz, näo se observaram diferenças estruturais entre os grupos estudados. Em ambos grupos näo se encontraram evidências de carcinoma da próstata. A análise morfométrica da altura do epitélio prostático näo demonstrou diferença significativa entre vasectomizados e simulados. Ultra-estruturalmente, as células epiteliais do grupo simulado apresentaram núcleo basal com contorno irregular, retículo endoplasmático rugoso amplamente distribuído, complexo de Golgi bem desenvolvidos, grânulos de secreçäo em diferentes graus de maturidade no citoplasma apical, e microvilos na superfície luminal. Detectou-se características similares nas células prostáticas dos animais vasectomizados, porém, nos períodos iniciais pós-cirurgia, o citoplasma apical continha menor quantidade de grânulos de secreçäo. Os resultados permitem sugerir que a secreçäo prostática diminui logo após a vasectomia, voltando à normalidade posteriormente. Nos ratos vasectomizados, as células epiteliais do lobo ventral da próstata näo demonstraram quaisquer sinais de degeneraçäo ou de carcinoma como efeito da vasectomia.

Avaliaçäo da efetividade de soluçöes desinfetantes utilizadas para o controle de infecçäo cruzada em filmes radiográficos intrabucais / Effectiveness evaluation of desinfection solutions on cross-contamination control in periapical radiographic films

O presente trabalho visou demonstrar a necessidade do controle de infecçäo cruzada em procedimentos radiográficos intrabucais, além de elaborar e testar um sistema de controle de infecçäo cruzada por meio de algumas substâncias de fácil acesso em nosso país. Foram testados como desinfetantes das superfícies dos filmes periapicais as soluçöes: álccol 77 por cento v/v; hipoclorito de sódio 2 por cento; água oxigenada a 3 por cento; e glutaraldeído 2 por cento. A amostra foi composta por 80 filmes que, após remoçäo da cavidade bucal, foram divididos em 7 grupos experimentais, contendo 10 filmes cada, e um grupo controle, também composto por 10 filmes, onde näo se utilizou nenhum método de desinfecçäo. Para os 7 grupos experimentais, realizou-se a desinfecçäo dos filmes segundo dois métodos: imersäo em soluçäo por 5 minutos e fricçäo com gaze esterilizada embebida na soluçäo por 30 segundos, com exceçäo de glutaraldeído, testado apenas para o método de imersäo. A efetividade das soluçöes empregadas foi avaliada pela semeadura de todos os filmes, tanto do grupo controle quanto do grupo experimental, na superfície de placas de ágar sangue (PROBAC), a fim de detectar a densidade de crescimento bacteriano. Os filmes, após serem submetidos à análise microbiológica, foram processados pelo método tempo/temperatura para verificar se as soluçöes usadas alteravam ou näo a imagem radiográfica. Das soluçöes testadas, o glutaraldeído 2 por cento, álcool 77 por cento v/v e hipoclorito de sódio 2 por cento se mostraram efetivos na desinfecçäo dos filmes, näo se observando crescimento bacteriano sobre as placas semeadas para ambos os métodos de desinfecçäo, enquanto que a água oxigenada, permitiu o crescimento de colônias bacterianas sobre as mesmas. Em todos os grupos testados näo ocorreu alteraçäo da imagem radiográfica após o processamento, indicando que as soluçöes empregadas näo prejudicaram a qualidade das imagens obtidas

Avaliaçäo bacteriológica da açäo do glutaraldeído utilizado como desinfetante em esofagogastroduodenofibroscopia / Bacteriological evaluation of the action of glutaraldehyde used as disinfecting agent in esophagogastroduodescopy

Foi estudado o efeito bacteriológico do glutaraldeído a 2 por cento, usado como desinfetante, em um esofagogastroduodenofibroscópio modelo Olympus GIFXQ. Realizaram-se culturas do material colhido na superfície externa e no canal operatório, antes do início da jornada de trabalho, imediatamente após uso no paciente e após limpeza e desinfecçao. Concluiu-se que, quando imerso em glutaraldeído a 2 por cento por dez minutos, fazendo-se também a aspiraçao do desinfetante pelo canal de biópsias e enxaguadura com soro fisiológico, nao houve crescimento bacteriano nem na superfície externa nem no canal operatório do aparelho, constituindo-se em procedimento eficaz para limpeza e desinfecçao.

Fibrovideo endoscopía de la vía biliar / Endoscopy biliary procedure

Se presentan 45 pacientes en los que se realizó endoscopía de la vía biliar. La vía utilizada fue: laparotómica en 35, laparoscópica en 4, transfistular en 3 y transhepática en otros 3. El tiempo de exploración promedio fue de 17,7 minutos y no hubo accidentes o complicaciones relacionadas con el método. En el 27 por ciento de los casos se modificó el diagnóstico inicial. En el 45 por ciento de los casos de litiasis coledociana, demostró persistencia de litiasis luego de la exploración instrumental. Por la mejor evaluación biliar, se realizaron 10 coledocorrafias primarias y 7 abordajes transcísticos. La principal ventaja de la endoscopía biliar es su efectividad para reducir a los niveles mínimos la incidencia de litiasis residual postoperatoria. Es un procedimiento versátil que puede realizarse por varios accesos a la vía biliar y permite definir el tratamiento en forma más racional