Hydraulic tracer studies in a pilot scale subsurface flow constructed wetland

Current design procedures for Subsurface Flow (SSF) Wetlands are based on the simplifying assumptions of plug flow and first order decay of pollutants. These design procedures do yield functional wetlands but result in over-design and inadequate descriptions of the pollutant removal mechanisms which occur within them. Even though these deficiencies are often noted, few authors have attempted to improve modelling of either flow or pollutant removal in such systems. Consequently the Oxley Creek Wetland, a pilot scale SSF wetland designed to enable rigorous monitoring, has recently been constructed in Brisbane, Australia. Tracer studies have been carried out in order to determine the hydraulics of this wetland prior to commissioning it with sealed sewage. The tracer studies will continue during the wetland's commissioning and operational phases. These studies will improve our understanding of the hydraulics of newly built SSF wetlands and the changes brought on by operational factors such as biological films and wetland plant root structures. Results to date indicate that the flow through the gravel beds is not uniform and cannot be adequately modelled by a single parameter, plug flow with dispersion, model. We have developed a multiparameter model, incorporating four plug flow reactors, which provides a better approximation of our experimental data. With further development this model will allow improvements to current SSF wetland design procedures and operational strategies, and will underpin investigations into the pollutant removal mechanisms at the Oxley Creek Wetland. (C) 1997 IAWQ. Published by Elsevier Science Ltd.

Use of confocal scanning laser microscopy to measure the concentrations of aerial and penetrative hyphae during growth of Rhizopus oligosporus on a solid surface

In order to develop a method for use in investigations of spatial biomass distribution in solid-state fermentation systems, confocal scanning laser microscopy was used to determine the concentrations of aerial and penetrative biomass against height and depth above and below the substrate surface, during growth of Rhizopus oligosporus on potato dextrose agar. Penetrative hyphae had penetrated to a depth of 0.445 cm by 64 h and showed rhizoid morphology, in which the maximum biomass concentration, of 4.45 mg dry wt cm(-3), occurred at a depth of 0.075 cm. For aerial biomass the maximum density of 39.54 mg dry wt(-3) occurred at the substrate surface. For both aerial and penetrative biomass, there were two distinct regions in which the biomass concentration decayed exponentially with distance from the surface. For aerial biomass, the first exponential decay region was up to 0.1 cm height. The second region above the height of 0.1 cm corresponded to that in which sporangiophores dominated. This work lays the foundation for deeper studies into what controls the growth of fungal hyphae above and below the surfaces of solid substrates. (C) Wiley Periodicals, Inc.

Embedded platform for ECG biometric recognition

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Electrónica e Telecomunicações

IMMUNODIAGNOSIS OF HUMAN STRONGYLOIDIASIS: USE OF SIX DIFFERENT ANTIGENIC FRACTIONS FROM Strongyloides venezuelensis PARASITIC FEMALES

SUMMARY The aim of this study was to evaluate six different antigenic fractions from Strongyloides venezuelensis parasitic females for the immunodiagnosis of human strongyloidiasis. Soluble and membrane fractions from S. venezuelensis parasitic females were prepared in phosphate-buffered saline (SSF and SMF, respectively), Tris-HCl (TSF and TMF, respectively), and an alkaline buffer (ASF and AMF, respectively). Serum samples obtained from patients with strongyloidiasis or, other parasitic diseases, and healthy individuals were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions SSF, TSF, and ASF showed 85.0%, 75.0%, and 80.0% sensitivity and 93.1%, 93.1%, and 87.5% specificity, respectively. Membrane fractions SMF, TMF, and AMF showed 80.0%, 75.0%, and 85.0% sensitivity, and 95.8%, 90.3%, and 91.7% specificity, respectively. In conclusion, the present results suggest that the fractions obtained from parasitic females, especially the SSF and SMF, could be used as alternative antigen sources in the serodiagnosis of human strongyloidiasis.

Comportamento da cepa LE de Schistosoma mansoni, após passagem em hospedeiro humano infectado acidentalmente

Uma auxiliar de laboratório infectou-se acidentalmente, com cercárias de Schistosoma mansoni, cepa LE, mantida rotineiramente em nossos laboratórios. Decorridos 5 meses, o exame parasitológico de fezes revelou 108 ovos/g . A pacientefoi tratada com oxamniquine, porém a infecção continuou ativa (6 ovos/g). Foi então obtido o isolado SSF mantido no modelo Biomphalaria glabrata - camundongo albino. Os resultados obtidos no estudo comparativo, entre o isolado SSF e a cepa LE, que lhe deu origem, mostraram que a duração do período pré-patente e o índice de infectividade em camundongos, bem como a resposta aos agentes esquistossomicidas (hycanthone, oxamniquine epraziquantel) não apresentaram diferenças estatisticamente significativas. Por outro lado, o número de miracídios obtidos dos intestinos e fígados dos camundongos infectados foi o dobro com a cepa LE, quando comparados com aquele do isolado SSF. Também a variação do peso dos animais foi bastante diferente. Concluiu-se que apenas uma passagem pelo hospedeiro humano não mudou substancialmente as características da cepa estudada.

Malnutrição em idosos na admissão hospital actuação perante a sua elevado prevalência

RESUMO: Ao longo das últimas décadas a redistribuição etária da população mundial tem vindo a apresentar um aumento do número de pessoas com 65 ou mais anos, integrando um grupo populacional comummente designado por população idosa. Importa aprofundar mecanismos fisiológicos que conduzem ao envelhecimento e de que forma podem condicionar não só aspetos clínicos, como também nutricionais, entre outros, com a perspetiva da sua origem no aparecimento de doenças crónicas. Com esse enfoque, a desnutrição na pessoa idosa é hoje considerada pela European Nutrition for Health Alliance(ENHA) um problema de saúde pública. Está descrito que a sua prevalência ronda os 60% a nível de instituições hospitalares, 40% em unidades residenciais e 5 a 10% na pessoa idosa a residir em domicílio próprio ou de familiares, e na sua maioria permanece por diagnosticar e tratar. Assim, foi objetivo deste estudo caracterizar e estimar a prevalência da desnutrição e do risco de desnutrição na pessoa idosa, nas primeiras 72 horas de admissão hospitalar. Aplicou-se um estudo observacional, analítico, transversal, quantitativo e correlacional, cujos dados foram recolhidos por entrevista ao próprio e por observação. O estudo desenvolveu-se em duas vertentes de investigação, uma focada na caracterização da desnutrição em pessoas idosas institucionalizadas em hospitais portugueses da zona centro e sul do Continente e Madeira, nos períodos de julho/agosto de 2009, abril/junho de 2010, maio/julho de 2011, através do MNA®. A outra, uma avaliação nutricional detalhada, efetuada no Centro Hospitalar de Lisboa Central – Hospital de Santa Marta, EPE, entre o início de janeiro de 2009 e o fim de janeiro de 2010, sendo a amostra recrutada de entre os idosos de ambos os sexos, internados. Foram estudados dados sociodemográficos, de saúde e feita uma avaliação nutricional extensa. A avaliação nutricional constou de colheita de parâmetros laboratoriais (hematológicos e bioquímicos) e antropométricos (índice de massa corporal (IMC), prega cutânea tricipital(PCT), prega cutânea subescapular (PCSE), perímetro braquial (PB), adequação do perímetro braquial (APB), área muscular braquial (AMB) e perímetro Geminal (PG), análise da composição corporal (Massa Gorda Corporal (MGC), Massa Isenta de Gordura (MIG)),caracterização de um dia alimentar tipo e questionário Mini Nutritional Assessment Long Form®– MNA LF®. Dos dados obtidos em hospitais portugueses, destaca-se que dos 402 idosos avaliados, 53% eram do sexo masculino, tinham uma idade média de 75,8 + 6,52 (65 – 100) e segundo o MNA® 57,5% encontravam-se Desnutridos ou em Risco de Desnutrição.Na amostra, dos dados obtidos, a nível sociodemográfico salienta-se que 50% dos doentes eram do sexo masculino, a idade média rondava os 75,5 + 7,22 (65 – 100) anos, 55% eram naturais de Lisboa e 80% residiam em Lisboa e Vale do Tejo, 38% não tiveram estudos formais e 43% fizeram-no apenas até ao 4º ano de escolaridade. Em relação aos dados de saúde, a maioria dos doentes foi admitida através do Serviço de Urgência do Centro Hospitalar de Lisboa Central – Hospital de São José e foram internados no Serviço de Medicina (38%) e no Serviço de Cardiologia (30%), por patologia médica (38%) e patologia do sistema circulatório (56%). Nos hábitos de vida, quanto à mobilidade, um terço dos doentes estavam acamados e os restantes deambulavam ou tinham uma mobilidade normal, 74% não apresentaram hábitos etanólicos regulares, 19% apresentavam um consumo elevado (> 30g de etanol/dia); 95% dos doentes não apresentavam hábitos tabágicos. Relativamente à caracterização nutricional, os valores médios encontrados em relação aos parâmetros laboratoriais revelaram-se inferiores aos valores padrão para a idade e sexo e eram inferiores no sexo feminino. Na caracterização antropométrica verificaram-se os seguintes achados: o cálculo do IMC mostrou-se pouco sensível na identificação de doentes desnutridos; a PCT e a PCSE revelaram valores de massa gorda dentro do intervalo considerado normal;segundo o PB, 88% não apresentavam valor indicativo de desnutrição e 8% estavam desnutridos; a APB identificou 50% de doentes desnutridos; a AMB, revelou que 97% dos homens e 95% das mulheres apresentavam deficit da massa magra e segundo o PG, 18% apresentavam um valor inferior a 31cm descritor de desnutrição. Na análise da composição corporal verificou-se que ambos os sexos apresentavam uma percentagem de MGC classificada como demasiado alta e que esta era superior nas mulheres em relação aos homens. Ao analisar a ingestão nutricional verificou-se que esta era inferior às Dietary Reference Intakes (DRIs) para a ingestão hídrica (p=0,00), energética (p=0,00), proteica (p=0,00), lipídica (p=0,01), MUFA (p=0,00), PUFA (p=0,00), e glícidos (p=0,00), fibra (p=0,02), potássio (p=0,00), cálcio (p=0,00), magnésio (p=0,00), fósforo (p=0,00), zinco (p=0,00), vitamina D (p=0,00), vitamina E (p=0,00) e folato (p=0,00). No que diz respeito ao MNA®, a sua aplicação permitiu identificar 62% de situações de risco nutricional ou de desnutrição já instalada. Valores de MNA® indicativos de desnutrição ou risco estavam associados a níveis de escolaridade mais baixos (r=0,32; p=0,00). Verificou-se correlação entre o MNA® e a PCT (r=0,30;p=0,00), PCSE (r=0,19;p=0,03) e PG (r=0,27;p=0,00). Na análise da amostra por sexo e escalão etário, apenas se distinguiram as mulheres mais velhas, que apresentaram situação de IMC indicador de risco de desnutrição (IMC <23,5 + 2,9, (r=0,42;p=0,02)), e de valores médios de PB de 25,6+3,84cm (r=0,42;p=0,01), em situações de menor mobilidade caraterizados pelo MNA®. Os homens maisvelhos apresentaram correlação entre o MNA® e PCSE (r=0,41;p=0,02), APMB (r=0,57;p=0,00)e PG (r=0,55;p=0,00), e as mulheres mais velhas apenas com a PCT (r=0,39;p=0,02). A análise multivariada do MNA® em função do sexo e do escalão etário, revelou que estes são independentes. Os homens apresentaram valores médios de MNA® superiores às mulheres e à medida que a idade aumenta, os valores de MNA® em ambos os sexos diminuem, sendo indicativos de risco de desnutrição. Consideramos que, tendo em conta a natureza e objetivos do presente estudo, foi possível caracterizar e estimar a prevalência da desnutrição e do risco de desnutrição em pessoas idosas nas primeiras 72 horas de admissão hospitalar. Os resultados obtidos sinalizam a sua elevada prevalência e alertam para a necessidade de procedimentos protocolados de avaliação e intervenção nutricional da população idosa na admissão hospitalar. Para este efeito a aplicação do MNA® provou a sua aplicabilidade, assim como a medição e cálculo da AMB, que poderão ser muito precocemente aplicados e contribuir para potenciar melhorias do estado de saúde e diminuir o tempo de internamento, nomeadamente de pessoas idosas. Em relação ao padrão alimentar, este estudo contribuiu para uma chamada de atenção dos profissionais de saúde que a população idosa pode apresentar carências nutricionais na admissão, e que estas se não forem devidamente sinalizadas e colmatadas tendem a agravar-se durante o internamento podendo contribuir para o aumento da morbilidade.-------------ABSTRACT:Over the last decades the age redistribution group of the population worldwide has been presenting an increasing number of people aged 65 years or more, incorporating a population group commonly referred to as the elderly population. It´s important to further analyze the physiological mechanisms that lead to aging and how they might influence not only clinical aspects, but also nutritional, among others, with the perspective of their origin in the onset of chronic diseases. With this approach, malnutrition in the elderly is now considered by the European Nutrition for Health Alliance (ENHA) a public health problem. It is reported that its prevalence is around 60% at the level of hospital units, 40% in residential units and 5 to 10% in the elderly living in their own home or family's, and mostly remains to diagnose and treat. The aim of this study was to characterize and estimate the prevalence of malnutrition and risk of malnutrition in the elderly, in the first 72 hours of hospital admission. We applied an observational, analytical, cross-sectional and correlacional quantitative type of study and data were collected by interview and observation itself. The study was developed in two lines of research: one focused on the characterization of malnutrition in elderly institutionalized in Portuguese hospitals, in the central and southern mainland and Madeira, in the periods between July - August 2009, April - June 2010, May - July 2011, through the MNA®; and the other: a detailed nutritional assessment, conducted in Hospital Lisbon Center - Hospital de Santa Marta, EPE, between early January 2009 and late January 2010, and the sample was recruited from among the elderly of both sexes at hospital admission. We studied intensively sociodemographic, health and nutritional assessment done extensive. Nutritional evaluation consisted of harvesting different parameters: hematological, biochemical and anthropometric (body mass index (BMI), triceps skinfold (TSF), sub-scapular skinfold (SSF), arm circumference (AC), arm muscle area (AMA), geminal perimeter (GP), analysis of body composition (Fat Mass (FM), Fat Free Mass (FFM)), characterization of a daily food type and Mini Nutritional Assessment Long Form® questionnaire - MNA LF®. Form the data obtained in Portuguese hospitals, it is noteworthy that of the 402 patients included, 53% were male, had a mean age of 75,8 + 6,52 (65 - 100) and, according to the MNA®, 57,5% were malnourished or at risk of malnutrition. In the sample, from the sociodemographic data obtained, we saw that 50% of patients were male, the average age was around 75,5 + 7,22 years (65-100), 55% were from Lisbon and 80 %lived in Lisbon, 38% had no formal education and 43% did so only until the 4th grade. Regarding health data, the majorities of patients were admitted through the ER of Hospital Lisbon Center - S. José Hospital - and were admitted to the Medicine Unit (38%) and to the Cardiology Unit (30%), by medical pathology (38%) and circulatory system disease (56%). In regard to lifestyle, and considering mobility, one third of patients were bedridden and the rest were ambulating or had a normal mobility. 74% had no regular ethanol habits, 19% had a high intake (> 30 g ethanol / day); 95% of the patients had no smoking habits. Regarding nutritional assessment, the mean values for laboratory parameters proved inferior to standard values for age and sex and were lower in females. In anthropometric assessment these were the findings: BMI calculation showed to be scarcely sensitive in the identification of undernourished patients; the TSF and SSF revealed values of fat mass within the normal range; in AC, 88% did not have an indicative value of malnutrition and 8% were malnourished; in AMA, 97% of men and 95% women had a deficit of lean mass and in GP, 18% had a value of less than the 31cm malnutrition descriptor. In body composition analysis found that both sexes showed a percentage of FM ranked too high and this was higher in women compared to men. By analyzing the nutritional intake was found that this was less than the Dietary Reference Intakes (DRIs) for water intake (p=0,00), energy (p=0,00), protein (p=0,00), lipid (p=0,01), MUFA (p=0,00), PUFA (p=0,00), carbohydrates (p=0,00), fiber (p=0,02), potassium (p=0,00), calcium (p=0,00), magnesium (p=0,00), phosphorus (p=0,00), zinc (p=0,00), vitamin D (p=0,00), vitamin E (p=0,00) and folate (p=0,00). Regarding MNA®, its application identified 62% of cases of nutritional risk or malnutrition already installed. MNA® values indicative of malnutrition or risk were associated with lower levels of education (r=0,32; p=0,00). There was a correlation between the MNA ® and TSF (r =0,30, p = 0,00), SFF (r = 0,19, p = 0,03) and GP (r=0,27, p = 0,00). In the analysis of the sample by gender and age group, the highlight was in older women who had BMI status indicator of malnutrition risk (BMI <23,5 + 2,9 (r=0,42;p=0,02)) and mean values of AC 25,6 +3,84cm (r=0,42; p=0,01), in situations characterized by low mobility MNA®. Older men showed a correlation between the MNA® and SFF (r = 0,41; p = 0,02), AMA (r = 0,57; p = 0,00) and GP (r=0,55;p=0,00), and in older women only TSF showed a correlation(r = 0,39; p =0,02). Multivariate analysis of the MNA® by gender and age group, revealed that they are independent. The men had MNA® mean superior to women, and as the age increases, the values of MNA® in both sexes declined, being indicative of risk of malnutrition. We believe that, given the nature and objectives of the present study, it allowed us to characterize and estimate the prevalence of risk of malnutrition and malnutrition in older people during the first 72 hours of hospital admission. The results indicate a high prevalence and point to the need for protocol procedures of nutritional assessment and intervention in the elderly population at hospital admission. For this purpose the application of MNA® has proved its applicability, as well as measuring and calculating AMA, which may be applied in early stages thus contributing to enhance health state improvements and to shorten the time of hospitalization, particularly in elderly people. In relation to dietary pattern, this study contributed to call of attention from health professionals that the elderly may have nutritional deficiencies on admission, and that these are not properly marked and addressed tend to worsen during hospitalization may contribute to increased morbidity.

Sintomas somáticos inexplicados clinicamente: um campo impreciso entre a psiquiatria e a clínica médica

Quadros clínicos caracterizados por sintomas somáticos inexplicados devido a condições médicas gerais são muito freqüentes na prática médica e representam, em geral, um quarto a metade dos atendimentos em ambos os cuidados - primários e secundários. Atualmente são classificados na psiquiatria como transtornos somatoformes (TSs) e na clínica médica, como síndromes somáticas funcionais (SSFs). A categoria diagnóstica dos TSs tem sido questionada, suscitando proposta para sua extinção nas futuras classificações internacionais. As SSFs caracterizam-se mais por sintomas, sofrimento e incapacidade do que por patologias específicas, e incluem fibromialgia, síndrome do intestino irritável (SII), síndrome da fadiga crônica, várias síndromes dolorosas, entre outras. A sobreposição dos quadros clínicos leva ao questionamento da existência de um ou vários diagnósticos, tanto entre diferentes SSFs como entre elas e os TSs, apontando também para a questão da co-morbidade. Um mesmo paciente, ao ser atendido por um psiquiatra, pode receber um diagnóstico de TS, mas, se encaminhado para um clínico, poderia receber o diagnóstico de SSF. Apresenta-se um campo impreciso, sugerindo, portanto, que deverão ocorrer modificações em termos de conceitualização, classificação diagnóstica e abordagem terapêutica. O estudo dos sintomas somáticos inexplicados clinicamente demonstra a necessidade de abordagens integradas. São mencionadas algumas experiências nesse campo do Programa de Atendimento e Estudos de Somatização da Universidade Federal de São Paulo (UNIFESP).

Bioethanol production by Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis from delignified coconut fibre mature and lignin extraction according to biorefinery concept

In search to increase the offer of liquid, clean, renewable and sustainable energy in the world energy matrix, the use of lignocellulosic materials (LCMs) for bioethanol production arises as a valuable alternative. The objective of this work was to analyze and compare the performance of Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis in the production of bioethanol from coconut fibre mature (CFM) using different strategies: simultaneous saccharification and fermentation (SSF) and semi-simultaneous saccharification and fermentation (SSSF). The CFM was pretreated by hydrothermal pretreatment catalyzed with sodium hydroxide (HPCSH). The pretreated CFM was characterized by X-ray diffractometry and SEM, and the lignin recovered in the liquid phase by FTIR and TGA. After the HPCSH pretreatment (2.5% (v/v) sodium hydroxide at 180 °C for 30 min), the cellulose content was 56.44%, while the hemicellulose and lignin were reduced 69.04% and 89.13%, respectively. Following pretreatment, the obtained cellulosic fraction was submitted to SSF and SSSF. Pichia stipitis allowed for the highest ethanol yield 90.18% in SSSF, 91.17% and 91.03% were obtained with Saccharomyces cerevisiae and Zymomonas mobilis, respectively. It may be concluded that the selection of the most efficient microorganism for the obtention of high bioethanol production yields from cellulose pretreated by HPCSH depends on the operational strategy used and this pretreatment is an interesting alternative for add value of coconut fibre mature compounds (lignin, phenolics) being in accordance with the biorefinery concept.

Valorization of eucalyptus wood by glycerol-organosolv pretreatment within the biorefinery concept: an integrated and intensified approach

The efficient utilization of lignocellulosic biomass and the reduction of production cost are mandatory to attain a cost-effective lignocellulose-to-ethanol process. The selection of suitable pretreatment that allows an effective fractionation of biomass and the use of pretreated material at high-solid loadings on saccharification and fermentation (SSF) processes are considered promising strategies for that purpose. Eucalyptus globulus wood was fractionated by organosolv process at 200 C for 69 min using 56% of glycerol-water. A 99% of cellulose remained in pretreated biomass and 65% of lignin was solubilized. Precipitated lignin was characterized for chemical composition and thermal behavior, showing similar features to commercial lignin. In order to produce lignocellulosic ethanol at high-gravity, a full factory design was carried to assess the liquid to solid ratio (3e9 g/g) and enzyme to solid ratio (8e16 FPU/g) on SSF of delignified Eucalyptus. High ethanol concentration (94 g/L) corresponding to 77% of conversion at 16FPU/g and LSR ¼ 3 g/g using an industrial and thermotolerant Saccharomyces cerevisiae strain was successfully produced from pretreated biomass. Process integration of a suitable pretreatment, which allows for whole biomass valorization, with intensified saccharification-fermentation stages was shown to be feasible strategy for the co-production of high ethanol titers, oligosaccharides and lignin paving the way for cost-effective Eucalyptus biorefinery.

Olive pomace pretreatments to enhance its valorisation by solid-state fermentation

Dissertação de mestrado em Bioengenharia

Response characteristics of arsenic-sensitive bioreporters expressing the gfp reporter gene

This paper describes the development of an analytical technique for arsenic analyses that is based on genetically-modified bioreporter bacteria bearing a gene encoding for the production of a green fluorescent protein (gfp). Upon exposure to arsenic (in the aqueous form of arsenite), the bioreporter production of the fluorescent reporter molecule is monitored spectroscopically. We compared the response measured as a function of time and concentration by steady-state fluorimetry (SSF) to that measured by epi-fluorescent microscopy (EFM). SSF is a bulk technique; as such it inherently yields less information, whereas EFM monitors the response of many individual cells simultaneously and data can be processed in terms of population averages or subpopulations. For the bioreporter strain used here, as well as for the literature we cite, the two techniques exhibit similar performance characteristics. The results presented here show that the EFM technique can compete with SSF and shows substantially more promise for future improvement; it is a matter of research interest to develop optimized methods of EFM image analysis and statistical data treatment. EFM is a conduit for understanding the dynamics of individual cell response vs. population response, which is not only a matter of research interest, but is also promising in the practical terms of developing micro-scale analysis.

Produção, propriedades e aplicação de celulases na hidrólise de resíduos agroindustriais

Cellulases have been intensively studied in the past few years, due to the interests in biofuels production from lignocellulosic materials, since they permit maintaining mild conditions during the conversion process. These enzymes can be produced by a broad variety of naturally occurring microorganisms, such as from genera Aspergillus, Trichoderma, Penicillium and Humicola. Targeting the increasing of expression levels, molecular biology tools have been used for heterologous genes insertion in host cells, e. g., Pichia pastoris and Escherichia coli. Enzymes from fungal cellulolytic complex usually act best at pH between 4 and 5 under temperatures from 40 to 60 °C and can be used for either sequential (SHF) or simultaneous (SSF) hydrolysis together alcoholic fermentation. In this review, the main raw materials for production of cellulases are identified, as well as the state of art of enzymes' properties, production and main applications.

Prevalência de Síndromes Funcionais em Estudantes e Residentes de Medicina

RESUMO O curso universitário é gerador de estresse, e, de acordo com a literatura, há elevada prevalência de sintomas depressivos e transtornos emocionais em até metade dos universitários. Cerca de um terço das pessoas com síndromes funcionais ou síndromes somáticas funcionais (SSF) sofre de ansiedade ou depressão. Percebe-se, assim, a associação das SSF com fatores psicossociais e estresse. Objetivo Verificar a prevalência de síndrome funcional em estudantes e residentes de Medicina. Métodos Foram entrevistados 200 estudantes da Faculdade de Medicina da Universidade Federal de Minas Gerais (UFMG) que cursavam o quinto, sexto, nono e décimo períodos, sendo 25 homens e 25 mulheres de cada período, bem como 27 residentes de várias especialidades do Hospital das Clínicas da UFMG (11 homens e 16 mulheres). Os voluntários responderam aos questionários Beck Depression Inventory (BDI) e Stait-Trait Anxiety Inventory (Stai), ambos validados no Brasil para avaliação da depressão e ansiedade, e a questionário para verificar a presença de síndromes funcionais. Resultados Oitenta e sete indivíduos (38,3%) tiveram o diagnóstico de síndrome somática e funcional (SSF), sendo prevalente nos residentes (48,1%) e nos alunos do quinto ano (43%) e menor nos alunos do terceiro ano (30%). Mulheres e seguidores da religião espírita foram os que apresentaram maior associação com SSF (p < 0,05), assim como os que possuíam maiores pontuações no questionário de avaliação de depressão e aqueles em período de formação mais avançado no curso médico. A SSF foi mais encontrada em estudantes com idade menor que 24 anos (39,4%), com renda inferior a dez salários mínimos (53,2%), casados (46,7%), com filhos (80%), entre os que possuíam parentesco médico (40,8), em tabagistas e alcoolistas (58,5%) e em estudantes com traços de ansiedade alta (45,6%). Conclusão As síndromes funcionais são frequentes entre os estudantes e residentes de Medicina. Elas ocorrem mais no sexo feminino e em deprimidos em períodos de maior tensão emocional.

Simultaneous allergen inactivation and detoxification of castor bean cake by treatment with calcium compounds

Ricinus communis L. is of great economic importance due to the oil extracted from its seeds. Castor oil has been used for pharmaceutical and industrial applications, as a lubricant or coating agent, as a component of plastic products, as a fungicide or in the synthesis of biodiesel fuels. After oil extraction, a castor cake with a large amount of protein is obtained. However, this by-product cannot be used as animal feed due to the presence of toxic (ricin) and allergenic (2S albumin) proteins. Here, we propose two processes for detoxification and allergen inactivation of the castor cake. In addition, we establish a biological test to detect ricin and validate these detoxification processes. In this test, Vero cells were treated with ricin, and cell death was assessed by cell counting and measurement of lactate dehydrogenase activity. The limit of detection of the Vero cell assay was 10 ng/mL using a concentration of 1.6 x 10(5) cells/well. Solid-state fermentation (SSF) and treatment with calcium compounds were used as cake detoxification processes. For SSF, Aspergillus niger was grown using a castor cake as a substrate, and this cake was analyzed after 24, 48, 72, and 96 h of SSF. Ricin was eliminated after 24 h of SSF treatment. The cake was treated with 4 or 8% Ca(OH)2 or CaO, and both the toxicity and the allergenic properties were entirely abolished. A by-product free of toxicity and allergens was obtained.

Influence de l'initiation de la traduction sur le changement programmé du cadre de lecture en -1 responsable de la synthèse des enzymes du virus de l’immunodéficience humaine de type 1

Le virus de l’immunodéficience humaine de type 1 (VIH-1) est responsable du syndrome de l’immunodéficience acquise (SIDA). Il faut identifier de nouvelles cibles pour le développement d’agents anti-VIH-1, car ce virus développe une résistance aux agents présentement utilisés. Notre but est d’approfondir la caractérisation de l’étape du changement de cadre de lecture ribosomique en -1 (déphasage -1) nécessaire à la production du précurseur des enzymes du VIH-1. Ce déphasage est programmé et effectué par une minorité de ribosomes lorsqu’ils traduisent la séquence dite glissante à un endroit spécifique de l’ARN messager (ARNm) pleine-longueur du VIH-1. L’efficacité de déphasage est contrôlée par le signal stimulateur de déphasage (SSF), une tige-boucle irrégulière située en aval de la séquence glissante. La structure du SSF est déroulée lors du passage d’un ribosome, mais elle peut se reformer ensuite. Nous avons montré que des variations de l’initiation de la traduction affectent l’efficacité de déphasage. Nous avons utilisé, dans des cellules Jurkat-T et HEK 293T, un rapporteur bicistronique où les gènes codant pour les luciférases de la Renilla (Rluc) et de la luciole (Fluc) sont séparés par la région de déphasage du VIH-1. La Rluc est produite par tous les ribosomes traduisant l’ARNm rapporteur alors que la Fluc est produite uniquement par les ribosomes effectuant un déphasage. L’initiation de ce rapporteur est coiffe-dépendante, comme pour la majorité des ARNm cellulaires. Nous avons examiné l’effet de trois inhibiteurs de l’initiation et montré que leur présence augmente l’efficacité de déphasage. Nous avons ensuite étudié l’effet de la tige-boucle TAR, qui est présente à l’extrémité 5’ de tous les ARNm du VIH-1. TAR empêche la liaison de la petite sous-unité du ribosome (40S) à l’ARNm et module aussi l’activité de la protéine kinase dépendante de l’ARN double-brin (PKR). L’activation de PKR inhibe l’initiation en phosphorylant le facteur d’initiation eucaryote 2 (eIF2) alors que l’inhibition de PKR a l’effet inverse. Nous avons étudié l’effet de TAR sur la traduction et le déphasage via son effet sur PKR en utilisant TAR en trans ou en cis, mais à une certaine distance de l’extrémité 5’ afin d’éviter l’interférence avec la liaison de la 40S. Nous avons observé qu’une faible concentration de TAR, qui active PKR, augmente l’efficacité de déphasage alors qu’une concentration élevée de TAR, qui inhibe PKR, diminue cette efficacité. Nous avons proposé un modèle où des variations de l’initiation affectent l’efficacité de déphasage en modifiant la distance entre les ribosomes parcourant l’ARNm et, donc, la probabilité qu’ils rencontrent un SSF structuré. Par la suite, nous avons déterminé l’effet de la région 5’ non traduite (UTR) de l’ARNm pleine-longueur du VIH-1 sur l’efficacité de déphasage. Cette 5’UTR contient plusieurs régions structurées, dont TAR à l’extrémité 5’, qui peut interférer avec l’initiation. Cet ARNm a une coiffe permettant une initiation coiffe-dépendante ainsi qu’un site d’entrée interne des ribosomes (IRES), permettant une initiation IRES-dépendante. Nous avons introduit cette 5’UTR, complète ou en partie, comme 5’UTR de notre ARNm rapporteur bicistronique. Nos résultats démontrent que cette 5’UTR complète inhibe l’initiation coiffe dépendante et augmente l’efficacité de déphasage et que ces effets sont dus à la présence de TAR suivie de la tige-boucle Poly(A). Nous avons aussi construit un rapporteur tricistronique où les ribosomes exprimant les luciférases utilisent obligatoirement l’IRES. Nous avons observé que cette initiation par l’IRES est faible et que l’efficacité de déphasage correspondante est également faible. Nous avons formulé une hypothèse pour expliquer cette situation. Nous avons également observé que lorsque les deux modes d’initiation sont disponibles, l’initiation coiffe dépendante est prédominante. Finalement, nous avons étudié l’effet de la protéine virale Tat sur l’initiation de la traduction et sur l’efficacité de déphasage. Nous avons montré qu’elle augmente l’initiation de la traduction et que son effet est plus prononcé lorsque TAR est située à l’extrémité 5’ des ARNm. Nous proposons un modèle expliquant les effets de Tat sur l’initiation de la traduction par l’inhibition de PKR ainsi que par des changements de l’expression de protéines cellulaires déroulant TAR. Ces résultats permettent de mieux comprendre les mécanismes régissant le déphasage du VIH-1, ce qui est essentiel pour le développement d’agents anti-déphasage.