Alterations in lipid transfer to High-Density Lipoprotein (HDL) and activity of paraoxonase-1 in HIV+ patients

HIV+ patients often develop alterations of the plasma lipids that may implicate in development of premature coronary artery disease. High-density lipoprotein (HDL) has an important role in preventing atherogenesis and the aim of this study was to investigate aspects of HDL function in HIV+ patients. HIV+ patients (n = 48) and healthy control subjects (n = 45) of both sexes with similar age were studied. Twenty-five were not being treated with antiretroviral agents, 13 were under reverse transcriptase inhibitor nucleosidic and non-nucleosidic (NRTI+NNRTI) and 10 were under NRTI + protease inhibitors (NRTI+PI) treatment. Paraoxonase 1 (PON1) activity and the transfer of free and esterified cholesterol, tryglicerides and phospholipids from a lipidic nanoemulsion to HDL were analyzed. In comparison with healthy controls, HIV+ patients presented low PON-1 activity and diminished transfer of free cholesterol and tryglicerides. In contrast, phospholipid transfer was increased in those patients, whereas the transfer of cholesteryl esters was unchanged. NRTI+NNRTI increases the transfer of cholesteryl esters and triglycerides but in NRTI+PI there was no difference in respect to non-treated HIV+ patients. HDL from HIV+ patients has smaller antioxidant properties, as shown by lower PON-1 activity, and the transfer of lipids to this lipoprotein fraction is also altered, suggesting that HDL function is defective in those patients.

Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs

Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).

Evaluation of Spatial interpolation techniques for mapping climate variables with low sample density: a case study using a new gridded dataset of Bangladesh

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Effect of Efavirenz on High-Density Lipoprotein Antioxidant Properties in HIV-Infected Patients

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * In previous work, we showed a long-term and concentration-dependent beneficial effect of the non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) on high-density lipoproteins (HDL) in human immunodeficiency virus (HIV)-infected patients. * Furthermore, it has been suggested that instead of the current practice of only measuring HDL-chelesterol values, the evaluation of HDL function, namely its antioxidant properties, might be an improved tool for identifying subjects at increased risk for cardiovascular events. * Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is responsible for HDL antioxidant function. WHAT THIS STUDY ADDS: * In the present work, we studied the effect of EFV on the activity of PON-1 and showed, for the first time, that EFV-based antiretroviral therapy is associated with a better antioxidant function, i.e. with a higher PON-1 activity. AIMS: A long-term and concentration-dependent beneficial effect of efavirenz (EFV) on cholesterol associated with high-density lipoprotein (HDL-c) in human immunodeficiency virus (HIV)-infected patients has been documented. Furthermore, it has been suggested that, instead of the current practice of only measuring HDL-c values, the evaluation of HDL quality might be an improved tool for identifying subjects at increased risk of cardiovascular events. Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is involved in the onset of cardiovascular disease and responsible for HDL antioxidant function. The aim of the present study was to investigate the effect of EFV on the circulating activity of PON-1 in HIV-infected patients. METHODS: The patients included were adults with a documented HIV-1 infection, nontreated or treated with antiretroviral regimens including EFV 600 mg once daily as first therapeutic regimen for at least 3 months. The influence of treatment with EFV, HDL-c and CD4 cell count on PON-1 activity was analysed. RESULTS: HIV-infected White patients treated with EFV had higher PON-1 activity [77.35 U l(-1) (65.66, 89.04)] (P < 0.05) and higher PON-1 activity : HDL-c ratio [1.88 (1.49, 2.28)] (P < 0.01) than untreated patients. PON-1 activity was higher in Black patients (P < 0.001) and in patients with a CD4 cell count >500 cells ml(-1) (P= 0.0120). CONCLUSIONS: EFV-based antiretroviral regimens are associated with HDL particles with a better antioxidant function, i.e. with a higher PON-1 activity. The PON-1 activity of Black patients is higher than that found in Whites regardless of treatment. Ethnicity should be taken into consideration when studying drug effects on PON-1 activity.

Validation of NASA rotor 67 with openFOAM's transonic density-based solver

Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica

Two stage abe fermentation with in situ pervaporation and high cell density

Dissertation presented to Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa for obtaining the master degree in Membrane Engineering

Humoral response towards high density lipoprotein : a new mechanism for atherogenesis

RESUMO:Aterosclerose é uma das principais causas de morbilidade e mortalidade no mundo ocidental. É responsável, direta ou indiretamente, pela maior percentagem de gastos com a saúde na maioria dos países europeus. A “teoria lipídica” da aterosclerose, que se baseia na dislipidemia como causa primária para a doença vascular tem algumas implicações práticas importantes: permite a definição de linhas de orientação e protocolos simples e ainda estabelece alvos terapêuticos que podem ser atingidos na maior parte dos casos com a atual intervenção farmacológica. A associação da aterosclerose com o sistema imunológico (a “teoria imunológica”), forneceu por sua vez novas formas de explorar os mecanismos envolvidos e abriu novas perspetivas para um conhecimento mais completo da doença. No entanto, levanta dificuldades evidentes no que diz respeito às possibilidades terapêuticas. De todos os intervenientes no processo aterosclerótico (bioquímicos, imunológicos e anatómicos), as lipoproteínas de elevada densidade (HDL) são atualmente reconhecidas como um dos fatores mais importantes na aterogénese. Isto é baseado no reconhecimento das múltiplas propriedades anti-aterogénicas das HDL como por exemplo: a anti-oxidante, a anti-inflamatória e a antitrombótica, bem como o seu importante papel na melhoraria da função endotelial. Atualmente, é consensual que as funções anti-aterogénicas das HDL vão além do seu papel no transporte reverso do colesterol (RCT) e a importância das HDL no processo aterosclerótico baseia-se não apenas no seu papel protetor impedindo a formação da placa de ateroma, mas também na estabilização destas, prevenindo a sua ruptura e, consequentemente o evento trombótico. Como fundamentais no processo aterosclerótico estão reconhecidos dois principais conjuntos de eventos: um caracterizado por alterações no metabolismo das lipoproteínas que resultam em lipoproteínas pró-inflamatórias e pró-oxidantes que interagem com os componentes celulares da parede arterial e que conduzem à formação da placa de ateroma; o outro evento é a resposta imunológica desencadeada contra um novo conjunto de antigénios que por sua vez leva à produção de citoquinas pró-inflamatórias. Dada a complexidade da HDL e das suas múltiplas funções estas lipoproteínas tornaram-se um potencial alvo para a resposta auto-imune, e cujas consequências podem explicar algumas das associações identificados em estudos clínicos e epidemiológicos. Contudo esta interação entre o sistema imunológico e HDL nunca foi exaustivamente estudada. Portanto, pomos a hipótese de que em condições oxidativas e pró-inflamatórias, um aumento do antigénio (HDL) conduz a um consequente acréscimo na produção de anticorpos anti-HDL (aHDL) responsáveis pela alteração quantitativa e / ou qualitativa das HDL. O conceito de que estes anticorpos podem contribuir tanto para a evolução a longo prazo do processo aterosclerótico, como para o desencadeamento de eventos clínicos pode também explicar a heterogeneidade encontrada em cada doente e nos grandes estudos clínicos, no que diz respeito aos fatores de risco e outcomes clínicos. Para além disso, a confirmação desta hipótese pode permitir explicar porque é que as intervenções terapêuticas atualmente em desenvolvimento para aumentar os níveis de HDL, não conseguem mostrar a tão esperada redução do risco vascular. O objetivo geral desta tese foi identificar e caracterizar a resposta humoral contra os componentes da HDL, e avaliar possíveis mecanismos que possam contribuir para a modificação das propriedades anti-aterogénicas das HDL. Para alcançar este objetivo investigou-se: 1) A presença de anticorpos aHDL em doentes com lúpus eritematoso sistémico (SLE) e em doentes com manifestações clínicas de aterosclerose, como os doentes com doença arterial coronária (CAD), acidente vascular cerebral isquémico (IS) e diabetes tipo 2; 2) Os principais alvos antigénicos dentro do complexo das HDL e a associação entre os títulos de anticorpos aHDL e diferentes características clínicas destas doenças; 3) As modificações das funções normais associadas às HDL, em particular da função anti-oxidante e anti-inflamatória; 4) A atividade biológica dos anticorpos aHDL isolados do soro de doentes através de um conjunto de experiências in vitro de inibição da atividade da paraoxonase 1 (PON1) e da expressão de moléculas de adesão em culturas de células endoteliais. Para tal foi necessário estabelecer um método de isolamento dos anticorpos. Os anticorpos aHDL isolados do soro de doentes foram utilizados de forma a identificar as potenciais alterações dos sistemas celulares utilizados; 5) O efeito de fármacos usados no tratamento das dislipidemias, em particular o ácido nicotínico e as estatinas, na variação dos títulos de anticorpos aHDL através de ensaios clínicos randomizados, controlados com placebo e em dupla ocultação. Os métodos utilizados neste trabalho incluíram: técnicas imunológicas (como por exemplo, enzyme-linked immunoabsorbent assay - ELISA, ensaio imunoturbidimetrico e cromatografia de imuno-afinidade) técnicas bioquímicas (tais como a quantificação de atividade enzimática por espectrofotometria e por luminescência), experiências com cultura de células e citometria de fluxo. Os nossos resultados mostram que: 1) A presença de anticorpos aHDL, e mais especificamente anticorpos contra alguns do seus principais componentes como a apolipoproteína A-I (ApoA-I, principal apolipoproteína presente nas HDL) e a PON1 (o enzima que mais contribui para a propriedade anti-oxidante das HDL), quer em doentes com doenças auto-imunes, como o SLE, quer em doentes com manifestações clínicas de aterosclerose, como CAD, IS e diabetes tipo 2. Os doentes apresentaram títulos de anticorpos IgG aHDL, aApoA-I e aPON1 significativamente mais elevados do que controlos saudáveis com a mesma idade e sexo. 2) A correlação positiva estatisticamente significativa entre os títulos de aHDL e aApoA-I e aPON1 sugere que estes sejam dois dos principais alvos antigénicos dentro do complexo das HDL. Os anticorpos encontrados nestes doentes estão associados com a diminuição da atividade da PON1 e a uma redução da capacidade anti-oxidante total (TAC) do soro, um aumento dos biomarcadores de disfunção endotelial (como por exemplo dos metabolitos do óxido nítrico - NO2- e NO3-, as moléculas de adesão vascular e intracelular - VCAM-1 e ICAM-1 e os níveis de 3-nitrotirosina). Nos doentes com SLE os títulos destes estão associados a um aumento do dano cardiovascular e à atividade global da doença avaliados pelas escalas SLICC/ACR DI e BILAG score, respetivamente. Enquanto que nos doentes com diabetes tipo 2 estes anticorpos estão associados com um aumento dos níveis de glicemia em jejum (FGP) e hemoglobina glicada (HbA1c). 3) Após se ter estabelecido um método de isolamento dos anticorpos que permite isolar quantidades significativas de anticorpos do soro de doentes sem perder a sua especificidade, foi identificada a capacidade dos anticorpos isolados do soro de doentes inibirem de uma forma dependente da concentração a atividade da PON1 até um máximo de 70% no caso dos doentes com SLE e ente 7-52% no caso dos anticorpos isolados de doentes com CAD e IS. 4) O efeito anti-inflamatório das HDL na inibição da produção de VCAM-1 induzida por citoquinas (como o TNF-) foi revertido em mais de 80% pelos anticorpos aHDL isolados do soro de doentes. 5) A angiogenesis induzida por HDL através do aumento do fator de crescimento do endotélio vascular (VEGF) foi anulada em 65% pelos anticorpos aHDL isolados do soro de doentes. 6) Os atuais agentes farmacológicos disponíveis para aumentar as concentrações de HDL-C estão associados a um aumento dos títulos de anticorpos.-------- ABSTRACTAtherosclerosis is the major cause of morbidity and mortality in the western world. It is also responsible, directly or indirectly, for the highest percentage of health costs in most European countries. Despite the use of new technologies for the diagnosis of vascular disease and regardless of the major advances in treatment, the atherosclerosis-related clinical burden is still raising. The “lipid theory” of atherogenesis, which identifies dyslipidemia as the primary cause of this vascular disease has some important practical implications: it allows the definition of simple guidelines and establishes therapeutic targets which can be generally met with current pharmacologic intervention. The association between atherosclerosis an the immune system (the immune concept) has in turn provided new ways of exploring the mechanisms involved in this condition and has opened new perspectives in the understanding of the disease. However, it raises obvious difficulties when it comes to treatment options. Of all the players (biochemical, immunological and anatomical) involved in this matter, high-density lipoproteins (HDL) are currently recognised as one of the most important factors in atherogenesis. This is based on the recognition of HDL's multiple anti-atherogenic properties: anti-oxidant, anti-inflammatory and antithrombotic, as well as its capacity to improve endothelial function. Nowadays, it is widely recognized that the anti-atherogenic functions of HDL go beyond reverse cholesterol transport (RCT), and the importance of HDL is based not just on its ability to reduce atheroma formation but also on its ability to stabilise plaques, therefore preventing their rupture and ultimately thrombosis. Two main set of events have been recognised as fundamental in atherogenesis: one, characterized by lipoprotein metabolism alterations, resulting in pro-inflammatory and pro-oxidative lipoproteins, which interact with the normal cellular elements of the arterial wall leading to atheroma formation; the other, the immune cellular response towards new sets of antigens which lead to the production of pro-inflammatory cytokines. Given to HDL complexity and multiple functions this lipoprotein has became a potential target for an auto-immune response, the consequences of which may explain some of the association identified in epidemiological and clinical studies, though the interaction between the immune system and HDL has never been thoroughly addressed. Therefore, we hypothesized that under oxidative and pro-inflammatory conditions, the increase in the antigen (HDL) would lead to a consequent increase in the production of anti-HDL (aHDL) antibodies be responsible for quantitative and/or qualitative changes of HDL. The concept that these antibodies may contribute either to the long-term evolution of atherosclerosis or to the triggering of clinical events may also explain the heterogeneity found in individual patients and in large cohorts regarding risk factors and clinical outcomes. Moreover this may be a major breakthrough in understanding why therapeutic interventions that increase HDL levels, failed to show the anticipated reduction in vascular risk. The overall aims of this thesis were to identified and characterize the humoral response towards HDL components and to evaluate the possible mechanisms that may contribute to the modifications of the anti-atherogenic properties of HDL. To achieve this objective we investigated: 1) the presence of aHDL antibodies in patients with systemic lupus erythematosus (SLE) and in patients with atherosclerosis-related clinical events, such as coronary artery disease (CAD), ischemic stroke (IS) and type 2 diabetes; 2) the association between the titres of aHDL antibodies and different clinical features of these diseases; 3) the modifications of the anti-atherogenic properties of HDL; 4) the biologic effect of aHDL antibodies isolated from serum of patients on the anti-oxidant and anti-inflammatory properties of HDL; 5) the effect of different pharmacologic treatments for dyslipidemia on the prevalence and activity of aHDL antibodies. The methodologies used in this work included immunologic-related techniques (e.g. enzyme-linked immunoabsorbent assay – ELISA, immunoturbidimetric immunoassay and immunoaffinity chromatography), biochemical techniques (enzymatic assays with quantification by spectrophotometry and luminescence methods), cell culture experiments and flow cytometry. Our results indicate that: 1) The titres of IgG aHDL, anti-apolipoprotein A-I (aApoA-I) and anti-paraoxonase 1 (aPON1) antibodies were higher in patients with SLE, CAD, IS and type 2 diabetes when compared with age and sex matched healthy controls. 2) The antibodies found in these patients were associated with decreased PON1 activity, (the enzyme responsible for most of the anti-oxidant effect of HDL), reduced total anti-oxidant capacity (TAC) of serum and increased biomarkers of endothelial dysfunction (nitric oxide metabolites, adhesion molecules, nitrotyrosine). In patients with SLE the antibody titres were associated with an increase in disease-related cardiovascular damage and activity whereas in patients with type 2 diabetes they were directly related with the fasting glucose plasma (FGP) levels and the glycosylated haemoglobin (HbA1c). 3) The antibodies isolated from serum of our patients, directly inhibited HDL-associated PON1 activity in a dose dependent way ranging from 7 to 52%. 4) The anti-inflammatory effect of HDL, measured by the percentage of inhibition of the cytokine-induced production of vascular adhesion molecules (VCAM-1), was reduced in more than 80% by aHDL antibodies isolated from our patients. 5) The HDL-induced angiogenesis by increasing vascular endothelial growth factor (VEGF) levels was abrogated in 65% by the antibodies isolated from serum of patients. 6) The current available pharmacologic agents for increasing HDL-C concentrations were associated with an increase in the titres of IgG aApoA-I antibodies. This increase was higher in the extended release niacin when compared to statins probably due to their dampening effect on oxidative stress. In conclusion, aHDL antibodies are present in different pathologic conditions. aHDL antibodies represent a family of self-reacting immunoglobulins, of which ApoA-I and PON1 might be the most relevant targets. These antibodies are biologically active, interfering with the HDL anti-oxidant and anti-inflammatory properties and, consequently, with the atherosclerotic process. The pathogenic potential of these antibodies may lead to the identification of a new biomarker for vascular disease, whilst presenting itself as a novel target for a different treatment approach which may redefine the treatment strategies and clinical trials design for HDL interventions in the future.

Landscape composition and climatic parameters significant in the spread of an invasive species (Pine wood Nematode)

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente

Characterization tests for insulation boards made from corn cob and natural glues

In recent years there has been a growing interest in developing news solutions for more ecologic and efficient construction, including natural, renewable and local materials, thus contributing in the search for more efficient, economic and environmentally friendly construction. Several authors have assessed the possibility of using various agricultural sub products or wastes, as part of the effort of the scientific community to find alternative and more ecologic construction materials. Corn cob is an agricultural waste from a very important worldwide crop. Natural glues are made from natural materials, non-mineral, that can be used as such or after some modifications to achieve the behaviour and performance required. Two examples of these natural glues are casein and wheat flour-based glues that were used in the present study. Boards with different compositions were manufactured, having as variables the type of glue, the dimension of the corn cob particles and the features of the pressing process. The tests boards were characterized with physical and mechanical tests, such as thermal conductivity (λ) with a ISOMET 2104 and 60 mm diameter contact probe, density (ρ) based on EN 1602:2013, surface hardness (SH) with a PCE Shore A durometer, surface resistance (SR) with a PROCEQ PT pendular sclerometer, bending behaviour (σ) based on EN 12089:2013, compression behaviour (σ10) based on EN 826:2013 and resilience (R) based on EN 1094-1:2008, with a Zwick Rowell bending equipment with 2 kN and 50 kN load cells (Fig. 1), dynamic modulus of elasticity (Ed) with a Zeus Resonance Meter equipment (Fig. 5) based on NP EN 14146:2006 and water vapour permeability (δ) based on EN 12086:2013. The various boards produced were characterized according to the tests and the ones with the best results were C8_c8 (casein glue, grain size 2,38-4,76 mm, cold pressing for 8 hours), C8_c4 (casein glue, grain size 2,38-4,76 mm, cold pressing for 4 hours), F8_h0.5 (wheat flour glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours), FEV8_h0.5 (wheat flour, egg white and vinegar glue, grain size 2,38-4,76 mm, hot pressing for 0,5 hours) and FEVH68_c4 (wheat flour, egg white, vinegar and 6 g of sodium hydroxide glue, grain size 2,38-4,76 mm, cold pressing for 4 hours). Taking into account the various boards produced and respective test results the type of glue and the pressure and pressing time are very important factors which strongly influence the final product. The results obtained confirmed the initial hypotheses that these boards have potential as a thermal and, eventually, acoustic insulation material, to use as coating or intermediate layer on walls, floors or false ceilings. This type of board has a high mechanical resistance when compared with traditional insulating materials.The integrity of these boards seems to be maintained even in higher humidity environments. However, due to biological susceptibility and sensitivity to water, they would be more adequate for application in dry interior conditions.

Analysis of sandflies (Diptera: Psychodidae) in Barra do Garças, State of Mato Grosso, Brazil, and the influence of environmental variables on the vector density of Lutzomyia longipalpis (Lutz & Neiva, 1912)

INTRODUCTION: Leishmaniasis is an infectious and parasitic zoonotic, non-contagious, vector-borne disease caused by protozoa of the genus Leishmania. In Brazil, the major vector of Leishmania (Leishmania) infantum chagasi (Cunha & Chagas, 1934) is Lutzomyia longipalpis. Barra do Garças, State of Mato Grosso, was designated as a priority area by the Brazilian Ministry of Health for american visceral leishmaniasis, and it is important to identify the vector species present in this municipality. Our objective was to raise sandflies and study the influence of environmental variables on the vector density of Lutzomyia longipalpis. METHODS: We performed entomological monitoring in 3 districts using Centers for Disease Control and Prevention (CDC) light traps and recorded human cases of american visceral leishmaniasis in the city. We calculated the relative frequency and richness of sandflies and applied a transfer function model to the vector density correlate with relative humidity. RESULTS: The sandfly population was composed of 2 genera and 27 species, totaling 8,097 individuals. Monitoring identified Lutzomyia longipalpis (44%), followed by Lutzomyia lenti (18.9%), Lutzomyia whitmani (13.9%), Lutzomyia carmelinoi (9.1%), Lutzomyia evandroi (5.1%), Lutzomyia termitophila (3.3%), Lutzomyia sordellii (1.9%), and 20 other species (<4%). The male:female ratio was 3.5:1. We observed high species diversity (Dα = 6.65). Lutzomyia longipalpis showed occurrence peaks during the rainy season; there was a temporal correlation with humidity, but not with frequency or temperature. CONCLUSIONS: The presence of Lutzomyia longipalpis in the urban area of Barra do Garças underscores the changing disease profile, which was previously restricted to the wild environment.

Design and characterization of novel biopolymeric structure using biocompatible ionic liquids

The main objective of this thesis was the development of polymeric structures from the dissolution of FucoPol, a bacterial exopolysaccharide (EPS), in a biocompatible ionic liquid, choline acetate. The FucoPol was produced by the bacteria Enterobacter A47 using glycerol as carbon source at controlled temperature and pH (30ºC and 7, respectively). At the end of 3 days it was produced 7 g/L of FucoPol. The net yield of Fucopol in glycerol (YP/S) was 0.22 g/g and the maximum productivity 2.37 g/L.d This polymer was characterized about its composition in sugars and acyl groups (by High-Performance Liquid Chromatography - HPLC), containing fucose (35 % mol), galactose (21 % mol), glucose (29 % mol), rhamnose (3% mol) and glucuronic acid (12% mol) as well as acetate (14.28 % mol), pyruvate (2.15 % mol) and succinate (1.80 % mol). Its content of water and ash was 15% p/p and 2% p/p, respectively, and the chemical bonds (determined by Infrared Spectroscopy - FT-IR) are consistent to the literature reports. However, due to limitations in Differential Scanning Calorimetry (DSC) equipment it was not possible to determine the glass transition temperature. In turn, the ionic liquid showed the typical behavior of a Newtonian fluid, glass transition temperature (determined by DSC) -98.03ºC and density 1.1031 g/cm3. The study of chemical bonds by FT-IR showed that amount of water (8.80%) influenced the visualization of the bands predicted to in view of their chemical structure. After the dissolution of the FucoPol in the ionic liquid at different temperatures (50, 60, 80 and 100 ° C) it was promoted the removal of this by the phase inversion method using deionized water as a solvent, followed by drying in an oven at 70 ° C. The mixtures before and after the phase inversion method were characterized through the studies mentioned above. In order to explore possible application field’s biocompatibility assays and collage on balsa wood tests were performed. It was found that the process of washing with water by the phase inversion method was not totally effective in removing the biocompatible ionic liquid, since all FucoPol – IL mixtures still contained ionic liquid in their composition as can be seen by the DSC results and FT-IR. In addition, washing the mixtures with water significantly altered the composition of FucoPol. However, these mixtures, that developed a viscous behavior typical of a non-Newtonian fluid (shear-thinning), have the potential to be applied in the biomedical field as well as biological glues.

Normal bone density in male pseudohermaphroditism due to 5alpha- reductase 2 deficiency

Bone is an androgen-dependent tissue, but it is not clear whether the androgen action in bone depends on testosterone or on dihydrotestosterone. Patients with 5alpha-reductase 2 deficiency present normal levels of testosterone and low levels of dihydrotestosterone, providing an in vivo human model for the analysis of the effect of testosterone on bone. OBJECTIVE: To analyze bone mineral density in 4 adult patients with male pseudohermaphroditism due to 5alpha-reductase 2 deficiency. RESULTS: Three patients presented normal bone mineral density of the lumbar column (L1-L4) and femur neck, and the other patient presented a slight osteopenia in the lumbar column. CONCLUSION: Patients with dihydrotestosterone deficiency present normal bone mineral density, suggesting that dihydrotestosterone is not the main androgen acting in bone.

Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

MANGROVE BARK: A RENEWABLE RESIN SOURCE FOR WOOD ADHESIVES

From four solutions tested to extract tannins from mangrove bark for wood adhesives, hot water is recommended. Hot water extracted 21.4% of formaldehyde-hydrochloric acid reactive polyphenols on oven-dry bark basis.

Wood specific gravity of trees and forest types in the southern Peruvian Amazon

Estimates of terrestrial biomass depend critically on reliable information about the specific gravity of the wood of forest trees. The study reported on here was carried out in the southern Peruvian Amazon and involved collection of wood samples from trees (70 spp.) in intact forest stands. Results demonstrate the high degree of variability in specific gravity (ovendry weight/green volume) in trees at single locations. Three forest types (swamp, high terrace forest with alluvial soil, and sandy-soil forest) had values close to the average reported for tropical forest woods (.69). Two early successional forest types, which make up as much as 12% of the total vegetated area in this part of the Amazon, had values significantly lower (.40). An increase in specific gravity with increasing age of the tree, which has been reported in some spe cies of tropical-forest woods, is seen in a positive relationship between specific gravity and di ameter for a species prevalent in one plot. Increases in specific gravity with tree and forest age may be significant in estimating changes in carbon stores over time.