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- Isolation, excystation and axenization of Giardia lamblia isolates: in vitro susceptibility to metronidazole and albendazolePublication . Cruz, Agostinho; Sousa, M. Isaura; Azeredo, Zaida; Leite, Emilia; Sousa, J. C. Figueiredo de; Cabral, MiguelFrom 53 samples of human faeces containing Giardia lamblia cysts, 18 isolates were successfully excysted in vitro, and cultivated axenically in TYI-S-33 modified medium. The in vitro effects of metronidazole and albendazole on these isolates were evaluated by the trophozoite adherence inhibition method. The IC50 was between 2.4 and 11.5 µM for metronidazole and 0.027 and 0.192 µM for albendazole. These IC50 values were similar to those found for the ATCC 30888 and 30957 reference isolates. All isolates were susceptible to the antiparasitic drugs tested. These results suggest that resistance of G. lamblia to metronidazole and albendazole does not seem to be a significant problem in our population.
- Comparison between two common methods for measuring Giardia lamblia susceptibility to antiparasitic drugs in vitroPublication . Cruz, Agostinho; Sousa, M. Isaura; Azeredo, Zaida; Silva, M. Carolina; Sousa, J.C. Figueiredo de; Manso, Olga; Cabral, MiguelIn this study a comparison between two different methods for measuring the susceptibility of Giardia lamblia trophozoites to metronidazole and albendazole is performed. Modifications of Meloni’s method, based on the loss of adherence of parasites to surfaces, and the Hill method, based on the loss of parasite division capacity, are compared. A logistic model was used to calculate the inhibitory concentrations IC10, IC50 and IC90 that were further compared using the respective standard errors. The results obtained, after contact of parasites with the antiparasitic drugs for 24 h, show that the adherence method is more sensitive than the multiplication method for low and moderate inhibitory concentrations of albendazole. Conversely for metronidazole the multiplication method seems to be more sensitive for high inhibitory concentrations of the drug. For screening the IC50, both methods seem to be effective, however, the inhibition of adherence method have even better performance for the benzimidazole like drugs.
- Avaliação da prevalência de Trichomonas vaginalis pelos métodos direto e culturalPublication . Alves, Maria José; Cruz, Agostinho; Balteiro, Jorge; Ferraz Oliveira, Rita; Cunha, AgostinhoA tricomoniose é a doença sexualmente transmitida não víral de maior prevalência nos seres humanos. Apresenta grande variabilidade de manifestações clínicas, desde a ausência de sintomas a um elevado risco de inflamação pélvica e ínfertilidade. Sinais clínicos e sintomas não são nem sensíveis nem específicos o suficiente para serem usados isoladamente no diagnóstico da tricomoniose, como tal o diagnóstico laboratorial é fundamental na detecção desta parasitose. A baixa sensibilidade dos métodos usados no diagnóstico laboratorial desta infecção subestima a sua prevalência. Consistiram em detenninar a prevalência de Trichomonas vaginalis em mulheres recorrendo ao exame directo e cultural com intuito de verificar as respectivas sensibilidades. Foi propósito demonstrar a importância da utilização sequencial destas duas metodologias no diagnóstico da tricomofíiose. As colheitas dos exsudados vaginais foram efectuadas em 288 mulheres que frequentavam a consulta de planeamento familiar dos Centro de Saúde 1, Centro de Saúde 2 e Hospital Distrital de Chaves, recorrendo a duas metodologias de diagnóstico (método Directo/Cultural). Das 288 mulheres investigadas a infecção por T. vaginalis foi detectada em 11 (3, 8%) recorrendo conjuntamente às duas metodologias. A infecção foi diagnosticada pelo método directo em 4 das 11 mulheres, no entanto o método cultural (Meio TYM) detectou os 11 casos positivos. Apesar de continuar a ser o mais utilizado no diagnóstico da tricomoniose o método directo apresentou uma sensibilidade de apenas 36,3%. Pela comparação de sensibilidades é visível a elevada precisão do método cultural relativamente ao directo. A associação destas duas metodologias poderá ser uma mais valia no diagnóstico da tricomoniose.
- Epidemiologia de trichomonas vaginalis em mulheresPublication . Alves, Maria José; Oliveira, Rita; Balteiro, Jorge; Cruz, AgostinhoA tricomoniose é uma das Doenças Sexualmente Transmissíveis (DSTs) não viral mais comum em todo mundo, com uma incidência anual superior a 180 milhões de casos. A Organização Mundial de Saúde estimou que esta infeção explica quase 50 % de todas as DSTs com cura em todo o mundo. Em Portugal poucos têm sido os trabalhos de carácter epidemiológico realizados sobre parasitose. Assim, o objetivo deste estudo consistiu em determinar a prevalência da T. vaginalis em mulheres que frequentam a consulta de planeamento familiar nos CSN.º1 CSN.º2 e Hospital em Chaves, e estabelecer uma possível associação desta parasitose com as características sociodemográficas, a sintomatologia, o comportamento sexual e o tratamento anterior deste tipo de parasitoses, através da resposta a um inquérito. Foi recolhida uma amostra de exsudado vaginal em 288 mulheres sintomáticas / assintomáticas para pesquisa de T. vaginalis recorrendo ao exame direto e cultural. Das 288 mulheres que aderiram ao estudo 11 (3,8 %) encontravam–se com tricomoniose. Variáveis como a idade, estado civil, grau de escolaridade, uso de contraceção, não apresentaram resultados estatisticamente significativos relativamente ao número de casos positivos. De entre os casos positivos apenas 54, 5 % das mulheres eram sintomáticas sendo as restantes 45,5 % assintomáticas. Uma associação estatisticamente significativa foi encontrada entre tricomoniose e múltiplos parceiros sexuais. Em suma, há necessidade de se seguirem outros estudos com o intuito de reavaliar o quadro atual desta parasitose em Portugal. Finalmente parece fundamental informar a população acerca dos elevados casos assintomáticos desta parasitose, bem com das consequências que desta podem advir.
- A case based learning model in therapeuticsPublication . Jesus, Ângelo; Gomes, Maria João; Cruz, AgostinhoNowadays, learning a Pharmaceutical Profession is an increasing challenge. Apart from traditional texts, lectures and self-guided individual learning, pharmaceutical educators are encouraged to find and implement ways to promote higher order thinking, collaborative learning and to increase students’ motivation. One way of achieving these objectives is to complement traditional learning methods with the development and implementation of Case Based Learning (CBL), supported in real life situations.Methods regarding real problems stand in contrast to a more traditional approach to learning and instruction. They promote learner-centered, small group, interactive learning experiences, instead of large group, didactic, teacher-centered instruction. Developing such a learning approach can be a challenge. In this sense, it becomes relevant to promote and share experiences already underway and by doing so, disseminate knowledge in this field. It is our goal with this text toshare our experience in the design and implementation of a Case Based Approach to Therapeutics.
- Overexpression of tumour-associated carbohydrate antigen sialyl-Tn in advanced bladder tumoursPublication . Ferreira, José Alexandre; Videira, Paula; Lima, Luís; Pereira, Sofia; Silva, Mariana; Carrascal, Milene; Severino, Paulo; Fernandes, Elisabete; Almeida, Andreia; Costa, Céu; Vitorino, Rui; Amaro, Teresina; Oliveira, Maria José; Reis, Celso; Dall'Olio, Fabio; Amado, Francisco; Santos, LúcioLittle is known on the expression of the tumour-associated carbohydrate antigen sialyl-Tn (STn), in bladder cancer. We report here that 75% of the high-grade bladder tumours, presenting elevated proliferation rates and high risk of recurrence/progression expressed STn. However, it was mainly found in non-proliferative areas of the tumour, namely in cells invading the basal and muscle layers. STn was also found in tumour-adjacent mucosa, which suggests its dependence on a field effect of the tumour. Furthermore, it was not expressed by the normal urothelium, demonstrating the cancer-specific nature of this antigen. STn expression correlated with that of sialyltransferase ST6GalNAc.I, its major biosynthetic enzyme. The stable expression of ST6GalNAc.I in the bladder cancer cell line MCR induced STn expression and a concomitant increase of cell motility and invasive capability. Altogether, these results indicate for the first time a link between STn expression and malignancy in bladder cancer. Hence, therapies targeting STn may constitute new treatment approaches for these tumours.
- Web 2.0 tools in biomedical education: limitations and possibilitiesPublication . Jesus, Ângelo; Gomes, Maria JoãoThe use of Web 2.0 technology is rapidly being integrated into undergraduate and graduate education, which dramatically influences the ways learners approach and use information. Knowledge transfer has become a two-way process. Users no longer simply consume and download information from the web; they create and interact with it. Several theoretical frameworks were developed in order to discuss the possibilities of integration of Web 2.0 tools in Pharmacy, Medicine, Allied Health, Nursing and many other biomedical areas. Other studies have started gathering qualitative and quantitative evidence of the importance of Web 2.0 tools in the learning process. By performing the integrative review, this paper will provide an overview of current research in biomedical education, and elaborate on some of the potential opportunities and challenges that these applications present. We hope to give our contribution to ongoing research in this promising area.
- Case based learning digital: estratégias de avaliação e colaboração onlinePublication . Jesus, Ângelo; Gomes, Maria João; Cruz, AgostinhoA adoção de atividades de formação a distância em modalidade de e-learning por instituições de ensino superior cuja área de intervenção tem sido essencialmente presencial, é considerada um importante contributo para a diversificação da oferta formativa, nomeadamente em termos de flexibilidade de gestão dos momentos e espaços de aprendizagem por parte dos estudantes. Contudo, a adesão dos professores à incorporação de práticas de e-learning nas suas atividades não é alheia a dificuldades. A esse nível é recorrente a existência de preocupações relacionadas com a avaliação das aprendizagens e da colaboração online. Neste contexto considera-se relevante divulgar práticas já em curso, partilhando experiências adquiridas e disseminando o conhecimento neste domínio. É nosso objetivo com este texto contribuir para uma aproximação dos educadores a esta problemática, através da partilha da nossa experiência na avaliação das aprendizagens e da colaboração online num contexto de ensino e aprendizagem da Farmácia e das Ciências Farmacêuticas.
- Response of high-risk of recurrence/progression bladder tumours expressing sialyl-Tn and sialyl-6-T to BCG immunotherapyPublication . Lima, Luís; Severino, Paulo; Silva, Mariana; Miranda, Andreia; Tavares, Ana; Pereira, Sofia; Fernandes, Elisabete; Cruz, Ricardo; Amaro, Teresina; Reis, Celso; Dall'Olio, Fabio; Amado, Francisco; Videira, Paula; Santos, Lúcio; Ferreira, José AlexandreHigh risk of recurrence/progression bladder tumours is treated with Bacillus Calmette-Guérin (BCG) immunotherapy after complete resection of the tumour. Approximately 75% of these tumours express the uncommon carbohydrate antigen sialyl-Tn (Tn), a surrogate biomarker of tumour aggressiveness. Such changes in the glycosylation of cell-surface proteins influence tumour microenvironment and immune responses that may modulate treatment outcome and the course of disease. The aim of this work is to determine the efficiency of BCG immunotherapy against tumours expressing sTn and sTn-related antigen sialyl-6-T (s6T). METHODS: In a retrospective design, 94 tumours from patients treated with BCG were screened for sTn and s6T expression. In vitro studies were conducted to determine the interaction of BCG with high-grade bladder cancer cell line overexpressing sTn. RESULTS: From the 94 cases evaluated, 36 had recurrence after BCG treatment (38.3%). Treatment outcome was influenced by age over 65 years (HR=2.668; (1.344-5.254); P=0.005), maintenance schedule (HR=0.480; (0.246-0.936); P=0.031) and multifocality (HR=2.065; (1.033-4.126); P=0.040). sTn or s6T expression was associated with BCG response (P=0.024; P<0.0001) and with increased recurrence-free survival (P=0.001). Multivariate analyses showed that sTn and/or s6T were independent predictive markers of recurrence after BCG immunotherapy (HR=0.296; (0.148-0.594); P=0.001). In vitro studies demonstrated higher adhesion and internalisation of the bacillus to cells expressing sTn, promoting cell death. CONCLUSION: s6T is described for the first time in bladder tumours. Our data strongly suggest that BCG immunotherapy is efficient against sTn- and s6T-positive tumours. Furthermore, sTn and s6T expression are independent predictive markers of BCG treatment response and may be useful in the identification of patients who could benefit more from this immunotherapy.
- Iron Overload Favors the Elimination of Leishmania infantum from Mouse Tissues through Interaction with Reactive Oxygen and Nitrogen SpeciesPublication . Vale-Costa, Sílvia; Gomes Pereira, Sandra Isabel; Teixeira, Carlos Miguel; Rosa, Gustavo; Rodrigues, Pedro Nuno; Tomás, Ana; Appelberg, Rui; Gomes, Maria SaloméIron plays a central role in host-parasite interactions, since both intervenients need iron for survival and growth, but are sensitive to iron-mediated toxicity. The host’s iron overload is often associated with susceptibility to infection. However, it has been previously reported that iron overload prevented the growth of Leishmania major, an agent of cutaneous leishmaniasis, in BALB/c mice. In order to further clarify the impact of iron modulation on the growth of Leishmania in vivo, we studied the effects of iron supplementation or deprivation on the growth of L. infantum, the causative agent of Mediterranean visceral leishmaniasis, in the mouse model. We found that dietary iron deficiency did not affect the protozoan growth, whereas iron overload decreased its replication in the liver and spleen of a susceptible mouse strain. The fact that the iron-induced inhibitory effect could not be seen in mice deficient in NADPH dependent oxidase or nitric oxide synthase 2 suggests that iron eliminates L. infantum in vivo through the interaction with reactive oxygen and nitrogen species. Iron overload did not significantly alter the mouse adaptive immune response against L. infantum. Furthermore, the inhibitory action of iron towards L. infantum was also observed, in a dose dependent manner, in axenic cultures of promastigotes and amastigotes. Importantly, high iron concentrations were needed to achieve such effects. In conclusion, externally added iron synergizes with the host’s oxidative mechanisms of defense in eliminating L. infantum from mouse tissues. Additionally, the direct toxicity of iron against Leishmania suggests a potential use of this metal as a therapeutic tool or the further exploration of iron anti-parasitic mechanisms for the design of new drugs.