Trypanosoma cruzi: cell charge distribution

Differences in cell charge between epimastigote and trypomastigote populations were compared in Y, Cl and Colombiana strains of T. cruzi. Trypomastigote populations were more homogenous in relation to cell charge than epimastigotes. This homogeneity of cell charge was not the result of the selection of trypomastigote sub-populations by the host immunosystem, but may be the result of a surface coat formed by host blood components.

Antigen characterization of vector-borne and cultured metacyclic trypomastigotes of Trypanosoma cruzi

Metacyclic trypomastigotes ol the CL strain of Trypanosoma cruzi obtained from triatomid vectors and from axenic cultures were comparatively analysed as to their antigen make-up and immunogenic characteristics. They were found to be similar by the various parameters examined. Thus, sera of mice immunized with either one of the two metacyclic types precipitated a 82Kd surface protein from 131I-labeled culture metacyclics. Sera of mice protected against acute T. cruzi infection by immunization with killed culture metacyclics of a different strain (G) recognized, by immunoblotting, a 77Kd protein in both types of CL strain metacyclics. A monoclonal antibody raised against G strain metacyclics, and specific for metacyclic stages of this strain, reacted with both CL strain metacyclic types. Both metacyclic forms were similarly Iysed by various anti-T. cruzi sera, in a complement-mediated reaction.

Avaliação de antígenos do trypanosoma cruzi para a reação de hemaglutinação indireta: II. Antígenos de diferentes amostras e formas evolutivas

Para aprimorar a sensibilidade e a especificidade da reação de hemaglutina-ção indireta no diagnóstico da doença de Chagas, foram utilizados eritrocitos sensibilizados com antígeno de epimastigotas de diferentes amostras (clones Al.7, B12, Cl e cepas D150 e Y), de tripomastigotas metacíclicos de cultura (TMC) e de tri-pomastigotas de cultura de células (TCC) do Trypanosoma cruzi. Foram titulados 132 soros de indivíduos chagásicos e 161 soros de não chagásicos, diagnosticados pela reação de imunofluorescência indireta (RIFI), considerada como reação de referência no cálculo dos índices de co-positividade (i.c.p.), co-negatividade (i.c.n.) e concordância. Utilizando o título discriminante (T.D.) de 1:40, os antígenos da cepa Y e do clone B12 apresentaram valores elevados para os três índices calculados, indicando boa sensibilidade e especificidade em relação à RIFI. Os antígenos dos clones Al .7 e Cl apresentaram baixa especificidade considerando o T.D. de 1:40, mas ocorreu um aumento acentuado para o i.c.n. considerando o T.D. de 1:80, indicando um aumento de especificidade relativa sem alteração significativa da sensibilidade relativa. Com os antígenos T.M.C, e T.C.C, foram observados títulos mais baixos e valores menores para o i.c.p., indicando pouca sensibilidade em relação à RIFI.

Primary bioreceptivity of limestones from the mediterranean basin to phototrophic microorganisms

Dissertação apresentada para a obtenção do grau de Doutor em Conservação e Restauro pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Screening the mutagenic activities of coomonly used antiparasite drugs by the Simultest, a simplified Salmonella/microsome plate incorporation assay

The mutagenic activities of 16 anti-parasite drugs were screened by the Simultest in both qualitative (spot test) and quantitative (plate incorporation) assays with a Salmonella typhimurium pool composed by the indicator strains TA97, TA 98, TA100 and TA102. Four anti Chagas' disease drugs (nifurtimox, benznidazole, CL 64,855, and MK 436) and two anti-amebae drugs (metronidazole and tinidazole) gave positive results in qualitative tests and incorporation of rat liver microsomes did not alter the results. Comparative dose response curves of the mutagenic activities of CL 64,855, metronidazole and benznidazole obtained by the simultest and by individual Salmonella indicator strains demonstrated that both approachs have similar sensitivities. The results corroborate the validity of the Simultest, as a simplified, fast and economic version of the Ames test in preliminary screening of potential mutagenic drugs.

Rheological behaviour of concrete made with fine recycled concrete aggregates - Influence of the superplasticizer

This paper evaluates the influence of two superplasticizers (SP) on the rheological behaviour of concrete made with fine recycled concrete aggregates (FRCA). Three families of concrete were tested: family CO made without SP, family Cl made with a regular superplasticizer and family C2 made with a high-performance superplasticizer. Five replacement ratios of natural sand by FRCA were tested: 0%, 10%, 30%, 50% and 100%. The coarse aggregates were natural gravels. Three criteria were established to design the concrete mixes' composition: keep the same particle size distribution curves, adjust the water/cement ratio to obtain a similar slump and no pre-saturation of the FRCA. All mixes had the same cement and SP content. The results show that the incorporation of FRCA significantly increased the shrinkage and creep deformation. The FRCA's effect was influenced by the curing age. The reference concrete made with natural sand stabilizes the creep deformation faster than the mixes made with FRCA. The incorporation of superplasticizer increased the shrinkage at early ages and decreased the shrinkage at 91 days of age. The regular superplasticizer did not improve the creep deformation while the high-performance superplasticizer highly improved this property. The incorporation of FRCA jeopardized the SP's effectiveness. This study demonstrated that to use FRCA and superplasticizer for concrete production it is necessary to take into account the different rheological behaviour of these mixes. (C) 2015 Elsevier Ltd. All rights reserved.

Evolution of subpatent parasitaemia in Trypanosoma cruzi chronically infected mice with the help of a cyclophosphamide amplification transfer assay

We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transferred with one Y strain parasite and in 20% of animals transferred with one CL strain parasite). Using acute phase bloodforms, the assay proved to be more sensitive than conventional subinoculation when dealing with the CL, but not the Y strain of the parasite. With the help of this parasite detection tool, we have studied during a one year period, the evolution of subpatent parasitaemias in a group of mice which survived through chemotherapy from lethal acute phase of T. cruzi infection. Cyclophosphamide transfer assay revealed occult parasitaemias in 100% of the chronic animals, nevertheless, continuous and discontinuous patterns of positivity were observed.

Trace metals in size-fractionated particulate matter in a Portuguese hospital: exposure risks assessment and comparisons with other countries

Hospitals are considered as a special and important type of indoor public place where air quality has significant impacts on potential health outcomes. Information on indoor air quality of these environments, concerning exposures to particulate matter (PM) and related toxicity, is limited though. This work aims to evaluate risks associated with inhalation exposure to ten toxic metals and chlorine (As, Ni, Cr, Cd, Pb, Mn, Se, Ba, Al, Si, and Cl) in coarse (PM2.5–10) and fine (PM2.5) particles in a Portuguese hospital in comparison with studies representative of other countries. Samples were collected during 1 month in one urban hospital; elemental PM characterization was determined by proton-induced X-ray emission. Noncarcinogenic and carcinogenic risks were assessed according to the methodology provided by the United States Environmental Protection Agency (USEPA; Region III Risk-Based Concentration Table) for three different age categories of hospital personnel (adults, >20, and <65 years) and patients (considering nine different age groups, i.e., children of 1–3 years to seniors of >65 years). The estimated noncarcinogenic risks due to occupational inhalation exposure to PM2.5-bound metals ranged from 5.88×10−6 for Se (adults, 55–64 years) to 9.35×10−1 for As (adults, 20–24 years) with total noncarcinogenic risks (sum of all metals) above the safe level for all three age categories. As and Cl (the latter due to its high abundances) were the most important contributors (approximately 90 %) to noncarcinogenic risks. For PM2.5–10, noncarcinogenic risks of all metals were acceptable to all age groups. Concerning carcinogenic risks, for Ni and Pb, they were negligible (<1×10−6) in both PM fractions for all age groups of hospital personnel; potential risks were observed for As and Cr with values in PM2.5 exceeding (up to 62 and 5 times, respectively) USEPA guideline across all age groups; for PM2.5–10, increased excess risks of As and Cr were observed particularly for long-term exposures (adults, 55–64 years). Total carcinogenic risks highly (up to 67 times) exceeded the recommended level for all age groups, thus clearly showing that occupational exposure to metals in fine particles pose significant risks. If the extensive working hours of hospital medical staff were considered, the respective noncarcinogenic and carcinogenic risks were increased, the latter for PM2.5 exceeding the USEPA cumulative guideline of 10−4. For adult patients, the estimated noncarcinogenic and carcinogenic risks were approximately three times higher than for personnel, with particular concerns observed for children and adolescents.

Permeable Reactive Barriers using nanoparticles to remediate nitrate pollution

Nitrat e (NO3 - ) i s per vasi ve i n t he bi ospher e[ 1, 2]. Cont emporar y agri cult ural pr acti ces are a mong t he maj or ant hr opogeni c sources of r eacti ve nitrogen speci es, wher e nitrat ei s t he most abundant of t hese [ 2]. Excessi ve a mount s of r eacti ve nitrogen i n soil s and gr oundwat er ar e creati ng si gnifi cant t hr eat s t o hu man healt h and saf et y [ 3] as well as a host of undesirabl e environment al i mpact s [ 2]; it i s curr ently consi der ed t he second most r el evant environment al i ssue, aft er car bon di oxide e mi ssi ons. Nowadays, a mong t he most r el evant and pr omi si ng appr oaches t o r educe nitrat e concentrati on i n wat er, na mel y gr oundwat er, ar e denitrifi cati on- based pr ocesses [ 4]. Per meabl e r eacti ve barri ers ( PRB) have been pr oven eff ecti ve i n r educi ng vari ous cont ami nant s i n copi ous a mount s, parti cul arl y i n shall ow gr oundwat er [ 5]. However t he possi bl e added eff ecti veness of usi ng nanoparti cl es i n t hese structur es t o obt ai n nitrogen gas from nitrat es requires f urt her i nvesti gati on.

Phase behaviour of alternative solvents

Dissertation presented to obtain the Ph.D. degree in Chemistry (Physical Chemistry) at the Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa

Cultura e desempenho nas organizações de economia social: um estudo em cooperativas

Este estudo tem como objetivo compreender a relação existente entre a cultura organizacional e o desempenho nas organizações de economia social, em particular nas cooperativas. A pertinência do objeto de estudo reside no facto de a economia social, em particular as cooperativas, ser reconhecidamente um fenómeno secular, tendo expressão na quase totalidade dos países do mundo, o que tem contribuído para o seu reconhecimento jurídico e político. A crescente importância que este setor tem adquirido nos diferentes países revela o seu potencial enquanto agente empregador e enquanto alternativa às formas organizacionais e gestionárias do sistema capitalista em vigor. Também, o cooperativismo representa um papel fundamental a nível da economia social, por ser um imprescindível ator da coesão social, promovendo a renovação da economia e sociedade, contribuindo para a criação de novas esperanças e oportunidades para as comunidades e os seus cidadãos. Por outro lado, no mundo globalizado em que se vive ocorrem mudanças que despertam a reavaliação de premissas culturais. Nesse sentido, a cultura organizacional é considerada um fator de grande importância para o bom desempenho das organizações em geral (Campos, Rédua & Alvareli, 2011). Para a recolha de dados, utilizou-se o questionário, tendo por base o Modelo dos Valores Contrastantes de Quinn & Rohbaugh (1983) para a cultura e, para o desempenho, recorreu-se ao Modelo de Análise de Medição do desempenho nas OES de Carvalho (2005) e questionário para medir a satisfação no trabalho.Os resultados contribuíram para sugerir linhas orientadoras para o aprofundamento da temática. Não foi encontrado um perfil cultural que esteja mais relacionado com o melhor desempenho das cooperativas. Neste trabalho, saiu evidenciado que: vários tipos de cultura podem ser importantes para a obtenção de bons desempenhos nas cooperativas, havendo maior predominância para as culturas de Clã, Adocracia e Mercado e menos predominância para a cultura de Hierarquia. No âmbito das cooperativas deste estudo, a cultura Hierarquia, percecionada como não predominante parece coocorre com o melhor desempenho. Realçando o facto de que, mesmo nas cooperativas em que não há procedimentos estruturados é possível ter um bom desempenho.

Avaliação da efectividade de uma intervenção em psiquiatria de ligação na doença coronária aguda

RESUMO: Várias intervenções psiquiátricas e psicossociais têm demonstrado ser eficazes na redução da depressão e da ansiedade em indivíduos que sofreram um acidente coronário agudo. A possiblidade de modificarem a evolução da doença coronária e de reduzirem a mortalidade cardíaca continua, no entanto, por comprovar. Este estudo teve como principal objectivo avaliar a efectividade de uma intervenção de Psiquiatria de Ligação (PL) em doentes com cardiopatia isquémica aguda. Métodos: um grupo inicial de 129 doentes consecutivos, internados por Enfarte Agudo do Miocárdio (EAM) ou Angina Instável, numa unidade de cuidados intensivos foi avaliado com a Hospital Anxiety e Depression Scale (HADS). Os doentes que apresentaram uma pontuação ≥8 nas subescalas da Depressão ou da Ansiedade (n=72) foram aleatoriamente distribuídos por grupo de intervenção (GI) (n=37) e grupo de controlo (GC) (n=35). O GI foi sujeito a uma intervenção de PL, realizada durante o período hospitalar, que se iniciou nos primeiros dias de internamento e consistiu em pelo menos 3 sessões individuais (incluindo avaliação psiquiátrica, psicoterapia de suporte, intervenção psicoeducativa e medicação, quando necessário). A sessão pré-alta envolveu o cônjuge e abordou a modificação de comportamentos de risco, a adesão terapêutica e o regresso ao trabalho. O GC recebeu os cuidados habituais da unidade de internamento. Todos os doentes completaram uma entrevista inicial para avaliação do estado cognitivo (Mini Mental State Examination – MMSE), do ajustamento social (Social Problems Questionnaire – SPQ) e de aspectos sociodemográfi cos e clínicos. Os doentes foram reavaliados antes da alta, aos 45 dias, 3 e 6 meses com a HADS, o SPQ e ainda com o Nottingham Health Profi le (NHP) para avaliação da qualidade de vida. No follow-up de 6 meses foi colhida informação sobre sobrevivência, número e duração de reinternamentos, número de dias de baixa e regresso ao trabalho. Resultados: na amostra de 129 doentes avaliados no início do internamento, 20,9% apresentavam níveis de depressão ≥8 na subescala da Depressão (HADS), 53,5% níveis de ansiedade ≥8 na subescala da Ansiedade (HADS) e 9,3% perturbações cognitivas (MMSE). A avaliação longitudinal desta amostra mostrou que os níveis de depressão, inicialmente baixos, aumentaram nos 45 dias após o internamento, para depois diminuírem até ao fi nal do follow-up. Os níveis de ansiedade, que eram inicialmente altos, aumentaram nos 45 dias seguintes e antiveram- se estáveis, mas altos, até ao fi m do estudo. O GI apresentou uma pontuação média na subescala da depressão signifi cativamente inferior à do GC no follow-up de 6 meses (5,8±4,1 no GI vs. 7,9±4,3 no GC, p=0,04). O número de doentes deprimidos foi signifi cativamente menor no GI nas avaliações realizadas aos 3 meses (11 vs. 18 no GC, p=0,04) e aos 6 meses (12 vs. 18 no GC, p= 0,05). O mesmo aconteceu com o número de doentes ansiosos aos 3 meses (15 no GI vs. 23 no GC, p=0,01). As dimensões do NHP “Isolamento social” aos 45 dias e “Reacção emocional” aos 45 dias e aos 3 meses, bem como a qualidade de vida geral (NHP 2ª parte) aos 3 meses, mostraram melhoria signifi cativa no grupo de intervenção. Embora a intervenção tenha reduzido o nível médio da ansiedade nas várias avaliações após a alta, esta redução não atingiu signifi cância estatística. A intervenção realizada não teve impacto na mortalidade ou nas variáveis relacionadas com a evolução da doença cardíaca no período do follow-up. Conclusões: Os resultados do presente estudo mostram a alta prevalência de depressão e de ansiedade após um acidente coronário agudo e a manutenção de níveis altos de ansiedade nos 6 meses seguintes. Os resultados comprovam também a efectividade de uma intervenção em PL no tratamento da depressão e da ansiedade em doentes que sofreram um acidente coronário agudo. Estes resultados apontam para a necessidade de desenvolvimento de programas de PL para este tipo de doentes, tanto no hospital geral como nos cuidados de saúde primários. Sugerem ainda a necessidade de desenvolvimento de investigação que permita estabelecer o impacto específi co dos diversos tipos de intervenção, assim como compreender os mecanismos subjacentes à associação da depressão e da ansiedade com a doença coronária.----------ABSTRACT:Different types of psychiatric and psychochosocial interventions have proven effi cacy in decreasing anxiety and depression in coronary heart disease. There is, however, an ongoing discussion about the impact these interventions may have on the clinical outcome and on cardiac mortality. The main objective of the current study was to evaluate the effectiveness of a consultation liaison psychiatry (CL) intervention on a group of patients admitted with Myocardial Infarction or Unstable Angina, to a Coronary Care Unit. Methods: The study had a prospective, randomised, controlled design, with a 6-month follow-up. One hundred and twenty-nine consecutive patients were assessed during the first 48 hours of admission with the Hospital Anxiety and Depression Scale (HADS). Those with a score of ≥8 on the Depression or the Anxiety subscales (n=72) were randomly allocated to intervention (n=37) and usual care (n=35). The CL intervention, started during the fi rst days of admission, had a minimum of 3 (60 minutes) sessions, and included a psychiatric evaluation, supportive psychotherapy, a psychoeducational intervention, when necessary, psychotropic drugs. The last session, shortly before discharge, included the spouse and was focused on compliance, modifi cation of behavioral risk factors, and possible diffi culties upon returning to work. Cognitive status (Mini-Mental State Examination - MMSE), social adjustment (Social Problems Questionnaire - SPQ), and demographic and clinical characteristics were also assessed at baseline. Patients were reassessed before discharge, and at 45 days, 3 and 6 months after admission with HADS, SPQ, and with Nottingham Health Profile (NHP) for quality of life. Survival, number of readmissions and days of readmission, number of sickleave days and return to work were assessed at six months. Results: The initial sample of 129 patients, presented a 20.9% prevalence of depressive symptoms, 53.5% of anxiety symptoms, and 9.3% of cognitive disorders. The longitudinal evaluation of this sample showed that the initially low levels of depression were increased 45 days later, and slowlly decreased afterwards till the 6-month follow-up. Initially high anxiety levels, somewhat decreased before discharge, had increased 45 days later, and stayed stable and high till the end of the study. The intervention group showed a signifi cantly lower depression mean score at 6 months (5.8±4.1 vs. 7.9±4.3 in the controls, p=0.04). The number of patients considered depressed was lower in the intervention group at 3(11 vs. 18 controls, p=0.04) and 6 months (12vs. 18 controls, p=0,05). The number of anxious patients was also lower in the intervention.

Immunoperoxidase for the detection for the detection of antibodies in cerebrospinal fluid in neurocysticercosis: use of Cysticercus cellulosae and Cysticercus longicollis particles fixed on microscopy slides

The ORF strain of Cysticercus longicollis represents an important model for the study of heterologous antigens in the immunodiagnosis of neurocysticercosis (NC). The immunoperoxidase (IP) technique was standardized using a particulate antigen suspension of Cysticercus longicollis (Cl) and Cysticercus cellulosae (Cc). Cerebrospinal fluid (CSF) samples were incubated on the antigen fixed to microscopy slides; the conjugate employed was anti-IgG-peroxidase and the enzymatic reaction was started by covering the slides with chromogen solution (diaminobenzidine/H2O2). After washing with distilled water, the slide was stained with 2% malachite green in water. Of the CSF samples from 21 patients with NC, 19 (90.5%) were positive, whereas the 8 CSF samples from the control group (100%) were negative. The results of the IP-Cl test applied to 127 CSF samples from patients with suspected NC showed 28.3% reactivity as opposed to 29.1 % for the IP-Cc test. The agreement index for the IP test (Cl x Cc) was 94.2%, with no significant difference between the two antigens.

Dot-ELISA for the detection of anti-Cysticercus cellulosae antibodies in cerebrospinal fluid using a new solid phase (resin-treated polyester fabric) and Cysticercus longicollis antigens

A dot-ELISA was developed for the detection of antibodies in CSF in the immunologic diagnosis of human neurocysticercosis, using antigen extracts of the membrane and scolex of Cysticercus cellulosae (M+S-Cc) and, alternately, membrane (M) and vesicular fluid (VF) of Cysticercus longicollis (Cl) covalently bound to a new solid phase consisting of polyester fabric treated with N-methylol-acrylamide resin (dot-RT). The test was performed at room temperature, with reduced incubation times and with no need for special care in the manipulation of the support. The sensitivity rates obtained were 95.1% for antigen Cc and 97.6% for antigen Cl. Specificity was 90.6% when Cc was used, and 96.9% and 100% when M-Cl and VF-Cl were used, respectively. No significant differences in titer were observed between tests carried out with homologous and heterologous antigens. The low cost and easy execution of the dot-RT test using antigen extracts of Cysticercus longicollis indicate the test for use in the immunodiagnosis of human neurocysticercosis.

HEMAGGLUTINATION TEST FOR THE DIAGNOSIS OF HUMAN NEUROCYSTICERCOSIS: DEVELOPMENT OF A STABLE REAGENT USING HOMOLOGOUS AND HETEROLOGOUS ANTIGENS

A hemagglutination (HA) test was standardized using formalin- and tannin-treated gander red blood cells sensitized with a total salt extract of C. cellulosae (HA-Cc) and an antigenic extract of Cysticercus longicollis (HA-Cl) vesicular fluid. A total of 61 cerebrospinal fluid (CSF) samples were assayed, 41 from patients with neurocysticercosis and 20 from a control group, which were, respectively, reactive and non-reactive to ELISA using C. cellulosae. The CSF samples from the control group did not react and 35 (85.4%) and 34 (82.9%) CSF samples from patients were reactive to the HA-Cc and HA-Cl tests, respectively. The reagents ready for use were stable up to 6 months when stored at 4°C in 50% glycerol. The present results confirm that the reagent using Cysticercus longicollis stabilized with glycerol can be used as an alternative in the immunological diagnosis of neurocysticercosis