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3.
Acta fisiátrica ; 30(1): 55-62, mar. 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1434953

RESUMO

The stretching with thermotherapies associated have been related in the literature as a way to increase the range of motion (ROM), but still are not consensus about this efficacy and costeffectiveness. The muscle stretching is a useful technique in rehabilitation and in physical activities programs, either to gain or maintain the flexibility, as a recovery of musculoskeletal and joint injuries. Objective: To determine the effects of thermotherapies associated to flexibility training in ROM of knee extension in healthy adults. Method: The search strategy was conducted in main databases, as Cochrane Library, LILACS, PEDro, PUBMED/ Medline, Scopus and Web of Science. The searches were done in 2016, and renewed in 2023, in order to achieve new publications along this time. Were selected only randomized clinical trials that have executed a training of hamstrings stretching, associated or not with one or more thermotherapies in healthy young adults, as long as the outcome was knee extension ROM. Only papers in Portuguese or English were assessed. To evaluate risk of bias was used the Cochrane Collaboration's Risk of Bias Tool, and the methodological quality assessment was rated following the PEDro Scale. Results: Eight articles were included, totalizing 260 participants. The papers showed low methodological quality, and uncertain risk of bias. Only chronic effect of local warming and cryotherapy plus stretching showed a statistically significant difference versus control group. However, the thermotherapy action associated with stretching is still unclear, once the results suggest that even without the thermotherapy there are ROM increases. Conclusion: The stretching is effective in knee extension ROM improvement in healthy adults, with or without thermotherapy. New studies with higher methodological rigor and standardized protocols are needed


Os alongamentos com termoterapias associadas têm sido relatados na literatura como forma de aumentar a amplitude de movimento (ADM), mas ainda não há consenso sobre sua eficácia e custo-efetividade. O alongamento muscular é uma técnica útil na reabilitação e em programas de atividades físicas, tanto para ganho ou manutenção da flexibilidade, quanto para recuperação de lesões musculoesqueléticas e articulares. Objetivo: Determinar os efeitos das termoterapias associadas ao treinamento de flexibilidade na ADM de extensão do joelho em adultos saudáveis. Método: A estratégia de busca foi realizada nas principais bases de dados, como Cochrane Library, LILACS, PEDro, PUBMED/ MedLine, Scopus e Web of Science. As buscas foram realizadas em 2016, e renovadas em 2023, a fim de alcançar novas publicações ao longo deste tempo. Foram selecionados apenas ensaios clínicos randomizados que tenham executado um treinamento de alongamento de isquiotibiais, associado ou não a uma ou mais termoterapias, em adultos jovens saudáveis, desde que o desfecho fosse ADM de extensão de joelho. Apenas artigos em português ou inglês foram avaliados. Para avaliar o risco de viés foi usado o Risk of Bias Tool da Cochrane Collaboration, e a avaliação da qualidade metodológica foi classificada de acordo com a Escala PEDro. Resultados: Foram incluídos oito artigos, totalizando 260 participantes. Os artigos apresentaram baixa qualidade metodológica e risco incerto de viés. Apenas o efeito crônico de aquecimento local e crioterapia associados ao alongamento mostrou uma diferença estatisticamente significativa em relação ao grupo controle. No entanto, a ação da termoterapia associada ao alongamento ainda não está clara, uma vez que os resultados sugerem que mesmo sem a termoterapia há aumento da ADM. Conclusão: O alongamento é eficaz na melhora da ADM de extensão do joelho em adultos saudáveis, com ou sem termoterapia. Novos estudos com maior rigor metodológico e protocolos padronizados são necessários

4.
Arch Gerontol Geriatr ; 105: 104868, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36402001

RESUMO

OBJECTIVE: To compare the results of different modalities of physical exercises on the sarcopenia diagnostic criteria in older people. METHODS: Systematic review of systematic reviews. Search strategy included older people and sarcopenia MeSh, performed at mainly databases. Selected studies include older adults, submitted to physical training (Intervention Group: IG) compared to control groups (CG). Quantitative analyses with the inverse variance statistic method (random effects). The effect measures mean difference. Heterogeneity measured with Q-Test. RESULTS: 494 systematic reviews found. After screening, 5 were included (48 papers. n=3,877). Mean age: 74.02±6.1. 73.44% female. Mean interventions duration: 17.38 weeks (average: 2.56 weekly sessions). AMSTAR and PRISMA showed high methodological quality. Meta-analyses compared results of resistance training interventions (RTA) with other than resistance (Non-resistance Training interventions: NRTA). Handgrip strength, skeletal muscle mass (SMM) and gait speed showed statistically significant differences (SSD) favorable to IG. In chair stand test, RTA showed SSD favorable to the IG, and NRTA to CG. The timed-up-and-go do not showed SSD. DISCUSSION: The SMM and strength showed better results in RTA, although the confidence intervals (CI) overlap. Both valences can be trained with similar volume and training intensity, which can modify muscle volume and strength. Physical performance obtained better results in NRTA, even with CI overlap. For severely sarcopenic, training including more than one valence may be best. In sarcopenia diagnosis most studies do not take into account the consensuses of standardization, making hard the larger groups analysis. CONCLUSION: Being part of any training program can be beneficial for sarcopenia in older people, with resistance training better for strength and SMM, and mixed modalities for physical performance.


Assuntos
Força da Mão , Treinamento de Força , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Masculino , Exercício Físico
5.
Artigo em Inglês | LILACS | ID: biblio-1525936

RESUMO

OBJECTIVE: To compare sarcopenia diagnosis according to 2 versions of the European Consensus on Sarcopenia (EWGSOP and EWGSOP2) in a sample of older adults. METHOD: This cross-sectional study included 82 community-dwelling older people from Porto Alegre, Brazil. The patients were assessed by trained professionals and were classified according to the criteria of the 2 versions of the consensus to show the differences between the classification models. RESULTS: The participants performed the Timed Up and Go test in < 7.21 seconds. On average, their performance on the 6-meter walk test was above the predicted value. Only 3 patients had a gait speed < 0.8 m/s. Handgrip strength was, on average, the predicted percentage. In the Short Physical Performance Battery, the scores of a few were intermediate but most were high. According to EWGSOP criteria, 92.18% were non-sarcopenic and 7.81% had severe sarcopenia, while according to EWGSOP2 criteria, 98.43% were non-sarcopenic, 1.56% were sarcopenic, and none had severe sarcopenia. The rate of sarcopenia diagnosis, which was 8.53% according to EWGSOP criteria, reduced to 3.65% according to EWGSOP2 criteria and the new cut-off points (p = 0.034). CONCLUSION: Although our sample was small, the reduction was significant, indicating that the change in criteria, even with lower cut-off points, reduced the probability of early diagnosis


OBJETIVO: Comparar a aplicação dos critérios e orientações das duas versões do Consenso Europeu sobre Sarcopenia (EWGSOP e EWGSOP2) para o diagnóstico e classificação, numa amostra de idosos residentes na comunidade. METODOLOGIA: Estudo transversal, com 82 idosos residentes na comunidade da cidade de Porto Alegre. Os pacientes foram avaliados por profissionais treinados e classificados segundo os critérios dos dois consensos para mostrar as diferenças entre os dois modelos de classificação.RESULTADOS: Em testes físicos como o timed up and go, a amostra realizou o teste em menos de 7,21 segundos. Em média, os idosos conseguiram caminhar no teste de caminhada de 6 metros mais do que a percentagem prevista para esse público. Apenas três pacientes apresentaram velocidade de caminhada inferior a 0,8 m/s. Na avaliação de força, os idosos conseguiram atingir, em média, o percentual previsto. No Short Physical Performance Battery, poucos tiveram desempenho intermediário. A maioria teve desempenho alto. Quando avaliados pelo EWGSOP, 92,18% eram não sarcopênicos, enquanto 7,81% eram sarcopênicos severos; e, quando avaliados pelo EWGSOP2, 98,43% eram não sarcopênicos, 1,56% sarcopênico e nenhum sarcopênico severo. A aplicação dos critérios EWGSOP2 e novos pontos de corte reduziram a capacidade de diagnóstico de sarcopenia na amostra de 8,53 para 3,65% (p = 0,034).CONCLUSÃO: Embora a amostra seja pequena, a redução é significativa e expressa que a mudança de critério, mesmo utilizando pontos de corte mais baixos para a amostra em análise, trouxe impacto no sentido de não diagnosticar precocemente


Assuntos
Humanos , Idoso , Sarcopenia/diagnóstico , Estudos Transversais , Consenso
6.
Arq. ciências saúde UNIPAR ; 27(10): 5961-5973, 2023.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1513159

RESUMO

Objective: To demonstrate the correlations of the diagnostic criteria for sarcopenia and the levels of Non-alcoholic Fat Liver Disease (NAFLD) assessed by liver biopsy in a physically active population. Methods: Cross-sectional study. Individuals aged >18 years, with NAFLD confirmed by liver biopsy, physically active. Sarcopenia assessment followed EWGSOP2: muscle strength by handgrip, Skeletal Muscle Mass by Bioimpedance, and physical performance by usual gait speed. Statistical Analysis: To test differences between groups in continuous variables, Student's T or Mann-Whitney U Test for independent samples. Pearson and Spearman tests were used for correlations. A 5% significance was considered (p<0.05). Results: 52 patients with NAFLD included, consisting of 35 women and 15 men. There was no difference in age or anthropometric variables. Were found difference statically significant in platelets (higher in women), basal insulin, HOMA-IR and Quick (higher in men). In sarcopenia, the handgrip strength showed difference in favors of men. There was no statistically significant correlation between the sarcopenia and NAFLD levels. Discussion: sarcopenia has been reported as an independent risk factor for NAFLD and its progressions. The physical exercise is one of the most recommended and more effective treatment for both conditions, so is expected that a non-sedentary individual can reduce both indicators. However, there is no consensus about the best method. Also, the both conditions share heterogeneity in diagnosis, prognosis, reason for develop and risk factors across the literature. Conclusion: For populations where most individuals are physically active, it is not possible to find correlation between sarcopenia diagnostic criteria and the stages of NAFLD.


Objetivo: Demonstrar as correlações dos critérios diagnósticos de sarcopenia e dos níveis de doença hepática gordurosa não alcoólica (DHGNA) avaliados por biópsia hepática em uma população fisicamente ativa. Métodos: Estudo transversal. Indivíduos com idade >18 anos, com DHGNA confirmada por biópsia hepática, fisicamente ativos. A avaliação da sarcopenia seguiu o EWGSOP2: força muscular por preensão manual, massa muscular esquelética por bioimpedância e performance física por velocidade usual de marcha. Análise Estatística: Para testar diferenças entre grupos nas variáveis contínuas, teste T de Student ou Teste U de Mann-Whitney para amostras independentes. Os testes de Pearson e Spearman foram utilizados para correlações. Foi considerada significância de 5% (p<0,05). Resultados: Foram incluídos 52 pacientes com DHGNA, sendo 35 mulheres e 15 homens. Não houve diferença na idade ou nas variáveis antropométricas. Foram encontradas diferenças estatisticamente significativas em plaquetas (maior em mulheres), insulina basal, HOMA-IR e Quick (maior em homens). Na sarcopenia, a força de preensão manual apresentou diferença em favor dos homens. Não houve correlação estatisticamente significativa entre os níveis de sarcopenia e DHGNA. Discussão: a sarcopenia tem sido relatada como fator de risco independente para DHGNA e suas progressões. O exercício físico é um dos tratamentos mais recomendados e mais eficazes para ambas as condições, pelo que se espera que um indivíduo não sedentário consiga reduzir ambos os indicadores. No entanto, não há consenso sobre o melhor método. Além disso, ambas as condições compartilham heterogeneidade no diagnóstico, prognóstico, razão de desenvolvimento e fatores de risco em toda a literatura. Conclusão: Para populações onde a maioria dos indivíduos é fisicamente ativo, não é possível encontrar correlação entre os critérios diagnósticos de sarcopenia e os estágios da DHGNA.


Objetivo: demostrar las correlaciones de los criterios diagnósticos de sarcopenia y los niveles de enfermedad del hígado graso no alcohólico (EHGNA) evaluados mediante biopsia hepática en una población físicamente activa. Métodos: Estudio transversal. Individuos mayores de 18 años, con EHGNA confirmada mediante biopsia hepática, físicamente activos. La evaluación de la sarcopenia siguió el EWGSOP2: fuerza muscular mediante agarre manual, masa muscular esquelética mediante bioimpedancia y rendimiento físico mediante velocidad de marcha habitual. Análisis estadístico: Para probar diferencias entre grupos en variables continuas, prueba T de Student o U de Mann-Whitney para muestras independientes. Para las correlaciones se utilizaron las pruebas de Pearson y Spearman. Se consideró una significancia del 5% (p<0,05). Resultados: Se incluyeron 52 pacientes con EHGNA, 35 mujeres y 15 hombres. No hubo diferencia en la edad ni en variables antropométricas. Se encontraron diferencias estadísticamente significativas en plaquetas (mayor en mujeres), insulina basal, HOMA- IR y Quick (mayor en hombres). En la sarcopenia, la fuerza de prensión manual mostró diferencia a favor de los hombres. No hubo correlación estadísticamente significativa entre la sarcopenia y los niveles de NAFLD. Discusión: la sarcopenia ha sido reportada como un factor de riesgo independiente para NAFLD y sus progresiones. El ejercicio físico es uno de los tratamientos más recomendados y efectivos para ambas afecciones, por lo que se espera que una persona no sedentaria pueda reducir ambos indicadores. Sin embargo, no hay consenso sobre cuál es el mejor método. Además, ambas afecciones comparten heterogeneidad en el diagnóstico, pronóstico, motivo de desarrollo y factores de riesgo en la literatura. Conclusión: Para poblaciones donde la mayoría de las personas son físicamente activas, no es posible encontrar correlación entre los criterios de diagnóstico de sarcopenia y las etapas de NAFLD.

7.
World J Transplant ; 13(6): 290-298, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38174151

RESUMO

The shortage of deceased donor organs has prompted the development of alternative liver grafts for transplantation. Living-donor liver transplantation (LDLT) has emerged as a viable option, expanding the donor pool and enabling timely transplantation with favorable graft function and improved long-term outcomes. An accurate evaluation of the donor liver's volumetry (LV) and anatomical study is crucial to ensure adequate future liver remnant, graft volume and precise liver resection. Thus, ensuring donor safety and an appropriate graft-to-recipient weight ratio. Manual LV (MLV) using computed tomography has traditionally been considered the gold standard for assessing liver volume. However, the method has been limited by cost, subjectivity, and variability. Automated LV techniques employing advanced segmentation algorithms offer improved reproducibility, reduced variability, and enhanced efficiency compared to manual measurements. However, the accuracy of automated LV requires further investigation. The study provides a comprehensive review of traditional and emerging LV methods, including semi-automated image processing, automated LV techniques, and machine learning-based approaches. Additionally, the study discusses the respective strengths and weaknesses of each of the aforementioned techniques. The use of artificial intelligence (AI) technologies, including machine learning and deep learning, is expected to become a routine part of surgical planning in the near future. The implementation of AI is expected to enable faster and more accurate image study interpretations, improve workflow efficiency, and enhance the safety, speed, and cost-effectiveness of the procedures. Accurate preoperative assessment of the liver plays a crucial role in ensuring safe donor selection and improved outcomes in LDLT. MLV has inherent limitations that have led to the adoption of semi-automated and automated software solutions. Moreover, AI has tremendous potential for LV and segmentation; however, its widespread use is hindered by cost and availability. Therefore, the integration of multiple specialties is necessary to embrace technology and explore its possibilities, ranging from patient counseling to intraoperative decision-making through automation and AI.

8.
RSC Adv ; 11(23): 14203-14212, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35423922

RESUMO

Conversion efficiency as high as 80-100% and 50% selectivity for camphene and limonene was achieved with low production of polymeric byproducts (18-28%), easy recovery with a magnet and reuse for up to five cycles maintaining similar activity and distribution of products, using a new magnetically recyclable catalyst based on niobium oxide coated on superparamagnetic iron oxide nanoparticles (SPION) impregnated with phosphotungstic acid (HPW). The catalyst was demonstrated to be effective in the selective conversion of alpha and beta-pinenes into valuable terpenes, under ultrasonic probe activation and with toluene as solvent. A unique synergic effect between the components generating more active and selective catalytic sites was demonstrated, indicating that the SPION covered with 30 wt% of Nb2O5 gives the best performance when impregnated with HPW as co-catalyst. The materials were fully characterized by XRD, EDX, XPS, TEM, BET, VSM and FTIR.

9.
Saúde debate ; 44(126): 790-804, jul.-set. 2020. tab
Artigo em Português | LILACS-Express | LILACS, Sec. Est. Saúde SP | ID: biblio-1139561

RESUMO

RESUMO O objetivo deste estudo foi relacionar o uso de agrotóxicos com a ocorrência de malformações congênitas no município de Giruá (RS), bem como determinar os fatores de risco associados. A pesquisa é de abordagem quantitativa, do tipo descritivo-exploratória, realizada durante o primeiro semestre de 2019. O estudo foi conduzido em duas etapas: (a) associação da ocorrência de malformações com o uso de agrotóxicos, que foi calculada por meio dos Odds Ratios, sendo o Intervalo de Confiança (IC) adotado para as amostras de 95%; e (b) determinação dos fatores de risco associados, em que foi realizada uma entrevista com agricultores residentes no município. Percebe-se que as taxas de malformações congênitas do município de Giruá são superiores à média do estado para o mesmo período. Há probabilidade de que a ocorrência de malformações no município esteja associada ao uso de agrotóxicos, pois todos os valores dos Odds Ratios foram maiores que um. Os fatores de risco identificados foram baixa escolaridade, classe toxicológica e princípios ativos, uso inadequado de Equipamentos de Proteção Individual (EPIs), número de pessoas com diagnóstico de intoxicação ou que relataram algum sinal ou sintoma associado e armazenamento dos produtos.


ABSTRACT The objective of this study was to relate the use of pesticides to the occurrence of congenital malformations in the city of Giruá (RS), as well as to determine the associated risk factors. The research has a quantitative, descriptive-exploratory approach, and was carried out during the first semester of 2019. The study was conducted in two stages: (a) association of the occurrence of malformations with the use of pesticides which was calculated using the Odds Ratios, with the Confidence Interval (CI) being adopted for the 95% samples; and (b) determination of the associated risk factors, for which an interview was conducted with farmers living in the municipality. It is noticed that the rates of congenital malformations in the city of Giruá, are higher than the state average for the same period. There is a probability that the occurrence of malformations in the municipality is associated with the use of pesticides, because all Odds Ratios were greater than one. The risk factors identified were low educational level, toxicological class and active principles, inadequate use of Personal Protective Equipment (PPE), number of people diagnosed with intoxication or who reported some associated signal or symptom and storage of the products.

10.
RSC Adv ; 10(63): 38490-38496, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35517526

RESUMO

Biodiesel is an alternative biodegradable and non-toxic fuel, with a low emission profile and capable of reducing significantly the level of carcinogenic pollutants released into the atmosphere. A newly designed nano-biocatalyst prepared by conjugation of lipase A on superparamagnetic iron oxide nanoparticles (SPIONs) demonstrated high efficiency for production of biodiesel by the reaction of soybean oil with anhydrous methanol. The nanomaterial was characterized by FTIR, TGA and XRD, and its enzymatic activity compared with Lipozyme 435, a commercial gold standard from Novozyme™, which presented average enzymatic activity of 4559 ± 75 only twice as large as that of the SPION-CAL-A catalyst (2283 ± 249 PLU g-1), whereas Lipozyme TLIM showed a much lower activity of 588 ± 16 PLU g-1. These results were confirmed in the transesterification reaction for production of biodiesel where a yield of 11.4% was achieved with Lipozyme 435 and 4.6 ± 0.5% with the nano-biocatalyst. Such an improved performance associated with easy magnetic recovery and reuse make the material potentially interesting for production of biodiesel from used cooking oil, adding value to this abundant resource.

11.
Mem. Inst. Oswaldo Cruz ; 110(1): 145-147, 03/02/2015. graf
Artigo em Inglês | LILACS | ID: lil-741613

RESUMO

Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition.


Assuntos
Animais , Feminino , Masculino , Camundongos , Suplementos Nutricionais , Diabetes Mellitus Experimental/dietoterapia , Hiperglicemia/prevenção & controle , Hipoglicemiantes/uso terapêutico , Liriope (Planta)/química , Tubérculos/química , Polissacarídeos/uso terapêutico , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Suplementos Nutricionais/efeitos adversos , Etnofarmacologia , Regulação Enzimológica da Expressão Gênica , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/isolamento & purificação , Resistência à Insulina , Glicogênio Hepático/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Fígado/patologia , Medicina Tradicional Chinesa , Pâncreas/metabolismo , Pâncreas/patologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/efeitos adversos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Polissacarídeos/administração & dosagem , Polissacarídeos/efeitos adversos , Polissacarídeos/isolamento & purificação , Distribuição Aleatória , Ratos Wistar , Testes de Toxicidade Aguda
12.
Rev. Inst. Adolfo Lutz ; 68(2): 215-223, maio-ago. 2009. tab
Artigo em Português | LILACS, Sec. Est. Saúde SP, SESSP-CTDPROD, Sec. Est. Saúde SP, SESSP-ACVSES, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: lil-544600

RESUMO

Os fungos termorresistentes dos gêneros Byssochlamys, Neosartorya e Talaromyces representam grave problema para a indústria processadora de alimentos, especialmente de frutas e hortaliças, em virtude da ocorrência de ascosporos extremamente resistentes e/ou de micotoxinas termo estáveis. Com o propósito de fornecer subsídios quanto ao uso de quantidades mais racionais de conservantes pela indústria de alimentos e, portanto, tornar seu consumo menos danoso à população, o presente estudo determinou in vitro a concentração mínima de metabissulfito de sódio, benzoato de sódio e sorbato de potássio necessária e suficiente para inibir o crescimento micelial e a germinação de ascósporos de B. fulva, N. fischeri e T.flavus em meio de cultivo acidificado (pH 3,5). Foi demonstrado que metabissulfito de sódio em baixas concentrações é tão eficiente na inibição dos fungos mencionados quanto aos demais conservantes em altas concentrações. Por comparação com os procedimentos utilizados pelas indústrias de alimentos, é possível inferir que estas podem reformular o uso de conservantes, considerando-se o tipo de matéria-prima, a temperatura de processamento, a combinação e concentração efetivamente necessária de aditivos, bem como os efeitos tóxicos desses compostos para a saúde humana.


Assuntos
Benzoato de Sódio , Fungos , Talaromyces
13.
Biotechnol Prog ; 21(3): 868-74, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15932267

RESUMO

The aim of this work was to select the operating conditions for the extraction and recovery of glucose oxidase (GOX) by reversed micelles from mixtures of commercial enzyme and Aspergillus niger homogenates. For this purpose, the influence of the main operating parameters (pH, surfactant concentration, and presence of cell debris or not) on GOX extraction was investigated at 25 degrees C. Without cell debris, the highest yield of GOX activity recovery (90.8%) was obtained performing (a) the forward extraction in isooctane as solvent and hexanol and butanol as cosolvents at 76/6/18 ratio, pH 7.0, 0.2 M cetyl trimethylammonium bromide as cationic surfactant, and electric conductivity of 5.0 mS cm(-1) and (b) the backward extraction at pH 5.5. Forward and backward extractions furnished comparable results when using raw homogenate, which demonstrates a negligible impact of the presence of cell debris on the process. The highest extraction yield (94%) was obtained under the same forward and backward conditions adopted without cell debris. The promising results of this work suggest that the proposed methodology could be profitably exploited at an industrial level.


Assuntos
Aspergillus niger/enzimologia , Centrifugação/métodos , Fracionamento Químico/métodos , Glucose Oxidase/biossíntese , Glucose Oxidase/isolamento & purificação , Solventes/química , Concentração de Íons de Hidrogênio , Micelas , Projetos Piloto , Soluções
14.
J Biotechnol ; 116(4): 411-6, 2005 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-15748768

RESUMO

Aim of this work was to establish the optimum operating conditions for the extraction and recovery by cationic reversed micelles of commercial glucose oxidase (GOX) from Aspergillus niger, in view of possible application to raw cell homogenates. The influence of pH, temperature, electric conductivity and solvent/co-solvents ratio on the extraction was investigated by a fractional factorial design of 2(3-1) type, conjugated with a mixture experimental design, using the residual enzyme activity to evaluate the results. The best conditions for GOX extraction were ensured using isooctane as solvent and hexanol and butanol as co-solvents at 76/6/18 volume ratio, pH 6.0, 0.2 M cetyl trimethylammonium bromide (CTAB) as cationic surfactant, and electrical conductivity (kappa) of 4.8 mS cm-1. The highest yield of GOX activity recovery (about 90%) was in fair accordance with the value predicted by the model.


Assuntos
Aspergillus niger/enzimologia , Centrifugação/métodos , Fracionamento Químico/métodos , Coloides/química , Coloides/isolamento & purificação , Técnicas de Química Combinatória/métodos , Glucose Oxidase/isolamento & purificação , Simulação por Computador , Micelas , Modelos Químicos , Soluções
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