Geossintéticos em vias de comunicação: influência das condições climáticas

Trabalho de Dissertação de Natureza Científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

Cell and humoral immunity in endemic pemphigus foliaceus

A study was conducted on 16 patients with pemphigus foliaceus, ten of them with the localized form (group G1) and six with the disseminated form (group G2). These patients were submitted to full blood counts, quantitation of mononuclear cell subpopulations by monoclonal antibodies, study of blastic lymphocyte transformation, and quantitation of circulating antibodies by the indirect immunofluorescence test, in order to correlate their clinical signs and symptoms and laboratory data with their immunological profile, and to determine the relationship between circulating autoantibody titers and lesion intensity and course of lesions under treatment. Leucocytosis was observed especially in group G2. All patients showed decreased relative CD3+ and CD4+ values and a tendency to decreased relative values of the CD8+ subpopulation. Blastic lymphocyte transformation indices in the presence of phytohemagglutinin were higher in patients (group G1+G2) than in controls. The indirect immunofluorescence test was positive in 100% of G2 patients and in 80% of G1 patients. The median value for the titers was higher in group G2 than in group G1. Analysis of the results as a whole permits us to conclude that cell immunity was preserved and that there was a relationship between antibody titers detected by the direct immunofluorescence test and extent of skin lesions.

Cyclophosphamide effect on paracoccidioidomycosis in the rat

Paracoccidioidomycosis is an endemic fungal disease widely distributed throughout Latin America. The potent immunosuppressor cyclophosphamide (CY) has been used to modulate host immune response to Paracoccidioides brasiliensis in an experimental model. Inbred male Buffalo/Sim rats weighing 250-300 g were inoculated with 5 x 10(6) P. brasiliensis cells of the yeast phase form by intracardiac route. One group of animals was treated with 20 mg/kg body weight at days +4, +5, +6, +7, +11 and +12 post-infection (pi.), while a control group was infected alone. No mortality was recorded in either group. Treated rats presented: a) a decrease in granuloma size, which contained less fungal cells; b) a lack of specific antibodies up to 35 days pi., and c) a significant increase in the footpad swelling test (DTH) against paracoccidioidin. Splenic cell transfer from CY-treated P. brasiliensis-infected donors to recipients infected alone led to a significant increase in DTH response in the latter versus untreated infected controls. Likewise, in treated infected recipients transferred with untreated infected donor spleen cells, footpad swelling proved greater than in controls. Thus, it would seem that each successive suppressor T lymphocyte subset belonging to the respective cascade may be sensitive to repeated CY doses administered up to 12 days pi.. Alternatively, such CY schedule may induce the appearance of a T cell population capable of amplifying DTH response.

Caracterização do transporte intermodal de cargas na zona norte de Portugal

Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Logística Orientado pela professora Doutora Maria Teresa Ribeiro Pereira Esta dissertação não inclui as críticas e sugestões feitas pelo Júri.

Some hematimetric findings in human Giardia lambia infection

Up to now few reports about haematological alterations induced by Giardia lamblia infection have been described. Because there are questions on this matter still not answered, we carried out a study to evaluate some erythrometric and leucometric parameters in a sample that consisted of 55 patients exclusively infected with G. lamblia and of 55 sex and age matched parasite-free individuals. The haematological parameters evaluated were: mean corpuscular volume (MCV), hemoglobin concentration, and relative and absolute number of eosinophils and lymphocytes. No significant differences in the mean values of MCV, hemoglobin levels and absolute relative lymphocyte numbers between the two groups could be detected. When the giardiasis and control groups were separated by pediatric (0-18 years old) and adult (older than 18 years) classes, a very significant difference in both relative and absolute number of eosinophils in the adult class was observed. With respect of the pediatric class, no differences, either in relative and absolute number of eosinophils, could be observed. Our findings suggest that, during G. lamblia infection, some kind of parasite allergen(s) could be secreted and be responsible for the increasing of eosinophil counts in peripheral blood of adults.

Screening pentachlorophenol degradation ability by environmental fungal strains belonging to the phyla Ascomycota and Zygomycota

Pentachlorophenol (PCP) bioremediation by the fungal strains amongst the cork- colonising community has not yet been analysed. In this paper, the co- and direct metabolism of PCP by each of the 17 fungal species selected from this community were studied. Using hierarchical data analysis, the isolates were ranked by their PCP bioremediation potential. Fifteen isolates were able to degrade PCP under co-metabolic conditions, and surprisingly Chrysonilia sitophila, Trichoderma longibrachiatum, Mucor plumbeus, Penicillium janczewskii and P. glandicola were able to directly metabolise PCP, leading to its complete depletion from media. PCP degradation intermediates are preliminarily discussed. Data emphasise the signiWcance of these fungi to have an interesting potential to be used in PCP bioremediation processes.

Análise de desempenho de algoritmos de otimização para extração de parâmetros em modelos semicondutores de potência

Apresenta-se nesta tese uma revisão da literatura sobre a modelação de semicondutores de potência baseada na física e posterior análise de desempenho de dois métodos estocásticos, Particle Swarm Optimizaton (PSO) e Simulated Annealing (SA), quando utilizado para identificação eficiente de parâmetros de modelos de dispositivos semicondutores de potência, baseado na física. O conhecimento dos valores destes parâmetros, para cada dispositivo, é fundamental para uma simulação precisa do comportamento dinâmico do semicondutor. Os parâmetros são extraídos passo-a-passo durante simulação transiente e desempenham um papel relevante. Uma outra abordagem interessante nesta tese relaciona-se com o facto de que nos últimos anos, os métodos de modelação para dispositivos de potência têm emergido, com alta precisão e baixo tempo de execução baseado na Equação de Difusão Ambipolar (EDA) para díodos de potência e implementação no MATLAB numa estratégia de optimização formal. A equação da EDA é resolvida numericamente sob várias condições de injeções e o modelo é desenvolvido e implementado como um subcircuito no simulador IsSpice. Larguras de camada de depleção, área total do dispositivo, nível de dopagem, entre outras, são alguns dos parâmetros extraídos do modelo. Extração de parâmetros é uma parte importante de desenvolvimento de modelo. O objectivo de extração de parâmetros e otimização é determinar tais valores de parâmetros de modelo de dispositivo que minimiza as diferenças entre um conjunto de características medidas e resultados obtidos pela simulação de modelo de dispositivo. Este processo de minimização é frequentemente chamado de ajuste de características de modelos para dados de medição. O algoritmo implementado, PSO é uma técnica de heurística de otimização promissora, eficiente e recentemente proposta por Kennedy e Eberhart, baseado no comportamento social. As técnicas propostas são encontradas para serem robustas e capazes de alcançar uma solução que é caracterizada para ser precisa e global. Comparada com algoritmo SA já realizada, o desempenho da técnica proposta tem sido testado utilizando dados experimentais para extrair parâmetros de dispositivos reais das características I-V medidas. Para validar o modelo, comparação entre resultados de modelo desenvolvido com um outro modelo já desenvolvido são apresentados.

Protection of C57BL/10 mice by vaccination with association of purified proteins from Leishmania (Leishmania) amazonensis

In the past few years, induction of protective immunity to cutaneous leishmaniasis has been attempted by many researchers using a variety of antigenic preparations, such as living promastigotes or promastigote extracts, partially purified, or defined proteins. In this study, eleven proteins from Leishmania (Leishmania) amazonensis (LLa) with estimated molecular mass ranging from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and electro-elution. The proteins were associated as vaccine in different preparations with gp63 and BCG (Bacilli Calmette-Guérin). The antigenicity of these vaccines was measured by their ability to induce the production of IFN-g by lymphocyte from subjects vaccinated with Leishvacinâ . The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were vaccinated with three doses of each vaccine consisting of 30 mg of each protein at 15 days interval. One hundred mg of live BCG was only used in the first dose. Seven days after the last dose, they received a first challenge infection with 105 infective promastigotes and four months later, a second challenge was done. Two months after the second challenge, 42.86% of protection was obtained in the group of mice vaccinated with association of proteins of gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa; 57.14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa, gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of gp63+46+40kDa that did not protect the mice, despite the good specific stimulation of lymphocytes (LSI = 7.60) and 10.77UI/ml of IFN-g production. When crude extract of L. (L.) amazonensis was used with BCG a 57.14% of protection was found after the first challenge and 28.57% after the second, the same result was observed for gp63. The data obtained with the vaccines can suggest that the future vaccine probably have to contain, except the 40kDa, a cocktail of proteins that would protect mice against cutaneous leishmaniasis.

Clinical and laboratory findings of disseminated Mycobacterium avium complex infection (DMAC) in a pair matched case-control study

A pair matched case/control study was conducted from January 1991 to 30 June 1992 in order to define clinical and laboratory findings associated with DMAC infection in AIDS patients. Since DMAC infection is usually associated with advanced immunodeficiency, and therefore also with other opportunistic illnesses, in addition to the number of CD4+ lymphocytes, cases and controls were matched using the following criteria: date of AIDS diagnosis and antiretroviral therapy, number and severity of associated opportunistic infections and, whenever possible, type of Pneumocystis carinii prophylaxis, age and gender, in this order of relevance. Cases (defined as patients presenting at least one positive culture for MAC at a normally sterile site) and controls presented CD4+ lymphocyte counts below 50 cel/mm3. A significantly higher prevalence of general, digestive and respiratory signs, increased LDH levels, low hemoglobin levels and CD4+ cell counts were recorded for cases when compared to controls. Increases in gGT and alkaline phosphatase levels seen in cases were also recorded for controls. In conclusion, the strategy we used for selecting controls allowed us to detect laboratory findings associated to DMAC infection not found in other advanced immunossupressed AIDS patients without DMAC.

Bacterial inter-species communication mediated by the autoinducer-2 signal

Dissertation presented to obtain the Ph.D degree in Biology by Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica, Instituto Gulbenkian de Ciência.

Bacillary angiomatosis: description of 13 cases reported in five reference centers for AIDS treatment in Rio de Janeiro, Brazil

The aim of this case series was to describe the clinical, laboratory and epidemiological characteristics and the presentation of bacillary angiomatosis cases (and/or parenchymal bacillary peliosis) that were identified in five public hospitals of Rio de Janeiro state between 1990 and 1997; these cases were compared with those previously described in the medical literature. Thirteen case-patients were enrolled in the study; the median age was 39 years and all patients were male. All patients were human immunodeficiency virus type 1 (HIV-1) infected and they had previous or concomitant HIV-associated opportunistic infections or malignancies diagnosed at the time bacillary angiomatosis was diagnosed. Median T4 helper lymphocyte counts of patients was 96 cells per mm³. Cutaneous involvement was the most common clinical manifestation of bacillary angiomatosis in this study. Clinical remission following appropriate treatment was more common in our case series than that reported in the medical literature, while the incidence of relapse was similar. The frequency of bacillary angiomatosis in HIV patients calculated from two of the hospitals included in our study was 1.42 cases per 1000 patients, similar to the frequencies reported in the medical literature. Bacillary angiomatosis is an unusual opportunistic pathogen in our setting.

Avaliação do papel da glutationa e do vacúolo como mecanismos de defesa contra a toxicidade induzida pelo chumbo na levedura Saccharomyces cerevisiae

A presença de metais pesados no meio ambiente deve-se, principalmente, a actividades antropogénicas. Ao contrário do Cu e do Zn, que em baixas concentrações são essenciais para o normal funcionamento celular, não se conhece para o chumbo nenhuma função biológica. O chumbo apresenta efeitos tóxicos, e considerado possível agente carcinogéneo, sendo classificado como poluente prioritário pela Agencia de Protecção Ambiental dos EUA (US-EPA). O presente trabalho teve como objetivo avaliar o papel da glutationa e do vacúolo, como mecanismos de defesa, contra os efeitos tóxicos induzidos pelo chumbo, usando como modelo a levedura Saccharomyces cerevisiae. A levedura S. cerevisiae quando exposta a varias concentrações de chumbo, durante 3h, perde a viabilidade e acumula espécies reativas de oxigénio (ROS). O estudo comparativo da perda de viabilidade e acumulação de ROS em células de uma estirpe selvagem (WT) e de estirpes mutantes, incapazes de produzir glutationa devido a uma deficiência no gene GSH1 (gsh1) ou GSH2 (gsh2) mostrou que as estirpes gsh1 ou(gsh2 não apresentavam um aumento da sensibilidade ao efeito toxico do chumbo. No entanto, o tratamento de células da estirpe WT com iodoacetamida (um agente alquilante que induz a depleção de glutationa) aumentou a sensibilidade das células a presença de chumbo. Pelo contrário, o enriquecimento em GSH, através da incubação de células WT com glucose e uma mistura de aminoácidos que constituem a GSH (acido L-glutâmico, L-cisteína e glicina), reduziu o stress oxidativo e a perda de viabilidade induzida por chumbo. A importância do vacúolo, como mecanismo de defesa, foi avaliada através da utilização de um mutante sem qualquer estrutura vacuolar (vps16) ou de mutantes deficientes na subunidade catalítica A (vma1) ou B (vma2) ou no proteolítico - subunidade C (vma3) da V-ATPase. As células da estirpe ƒ´vps16 apresentaram uma elevada suscetibilidade a presença de chumbo. As células das estirpes deficientes na subunidade A, B ou c da V-ATPase, apresentaram uma maior perda de viabilidade, quando expostas a chumbo, do que as células da estirpe WT, mas menor do que a da estirpe vps16 Em conclusão, os resultados obtidos, no seu conjunto, sugerem que a glutationa esta envolvida na defesa contra a toxicidade provocada por chumbo; todavia, a glutationa, por si só, parece não ser suficiente para suster o stress oxidativo e a perda de viabilidade induzida por chumbo. O vacúolo parece constituir um importante mecanismo de defesa contra a toxicidade provocada por chumbo. A V-ATPase parece estar envolvida na compartimentação de chumbo no vacúolo.

Cavin 1 and cavin 2 roles on adipocyte cell function

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Diagnosis of cytomegalovirus infections by qualitative and quantitative PCR in HIV infected patients

A high incidence of cytomegalovirus (CMV) infections is observed in Brazil. These viruses are causatives of significant morbidity and mortality among patients with advanced human immunodeficiency virus (HIV) infection. This work, shows the application of a PCR on determination of CMV load in the buffy coat and plasma. We analyzed the samples of 247 HIV infected patients in order to diagnose CMV infection and disease. We developed a semi-quantitative PCR that amplifies part of the glycoprotein B (gB) gene of CMV. The semi-quantitative PCR was carried out only in positive clinical samples in a qualitative PCR confirmed by a nested-PCR. CD4 lymphocyte count, HIV viral load and CMV disease symptom were correlated with CMV load. CMV genome was detected in the buffy coat of 82 of 237 (34.6%) patients, in 10 of these the CMV load was determined varying between 928 and 332 880 viral copies/mug DNA. None of these 237 patients developed any suggestive manifestation of CMV disease. For the other 10 HIV infected patients selected based on the suspicion of CMV disease, CMV genome was detected in only one case. This patient presented a high CMV load, 8 000 000 copies/mug DNA, and developed a disseminated form of CMV disease including hepatitis and retinitis. Our results were greatly influenced by the impact of the highly active antiretroviral therapy that reduced incidence of CMV viremia and occurrence of CMV disease in the HIV infected patients.

Enrichment of bioactive compounds in microalgae for aquaculture

Microalgae are promising microorganisms for the production of food and fine chemicals. Several species of microalgae are used in aquaculture with the purpose of transfer bioactive compounds up to the aquatic food chain. The main objective of this project was to develop a stress–inducement strategy in order to enhance the biochemical productivity of Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp. for aquaculture purposes having in account their growth and organizational differences. In this regard, two experiments were design: the first one consisted on the alteration of overall nutrient availabilities in growth medium; and the second one comprised changes in nitrogen and sulfur concentrations maintaining the concentrations of the other nutrients present in a commercial growth medium (Nutribloom plus), which is frequently used in aquaculture. Microalgae dried biomass was characterized biochemically and elemental analysis was also performed for all samples. In first experimental design: linear trends between nutrient availability in growth media and microalgae protein content were obtained; optimum productivities of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) were attained for both R. marina and N. gaditana in growth media enriched with 1000 L L-1 of nutrient solution whereas for Isochrysis sp. the double of Nutribloom plus was needed; the decrease of glucans and total monosaccharides with nutrient availability for R. marina and Isochrysis sp. showed the occurrence of a possible depletion of carbohydrates towards lipids and proteins biosynthesis. Second experimental desing: N. gaditana exhibited the highest variation in their biochemical composition against the applied perturbation; variations observed for microalgae in their biochemical composition were reflected in their elemental stoichiometry; in N. gaditana the highest nitrogen concentrations lead to overall maximum productivities of the biochemical parameters. The results of the present work show two stress-inducement strategies for microalgae that may constitute a base for further investigations on their biochemical enhancement.