Como melhorar a mobilidade ativa em São Paulo, Brasil? Inquérito com lideranças de organizações não governamentais e com gestores públicos e privados / How to improve active mobility in São Paulo, Brazil? Survey with leaders of nongovernmental organizations and public and private sector managers / ¿Cómo mejorar la movilidad activa en São Paulo, Brasil? Encuesta con líderes de organizaciones no gubernamentales y gestores públicos y privados

Resumo: Este estudo teve como objetivo descrever um inquérito quantitativo realizado com lideranças para investigar ações efetivas, viáveis e que podem ser testadas em modelos computacionais para informar políticas de promoção da mobilidade ativa, tendo como base a cidade de São Paulo, Brasil. Em 2022, foi realizado um inquérito online no contexto da pesquisa de Atividade Física e Ambiente do Inquérito de Saúde de São Paulo, acompanhada por representantes de organizações não governamentais, gestores públicos e de entidades privadas. Foi elaborado questionário com três perguntas com 13 alternativas de respostas sobre ações para promoção da caminhada ou uso de bicicleta. As lideranças deveriam selecionar até três alternativas a partir de seu potencial em termos de (1) efetividade; (2) viabilidade ou facilidade de implementação; e (3) desejo de realizar testes em modelos computacionais para informar políticas. O inquérito foi respondido por 18 lideranças de 16 instituições, sendo 13 (72%) mulheres e 12 (67%) representantes do terceiro setor, cuja média de idade era 48 anos, todos com nível superior de escolaridade. A redução da velocidade dos veículos motorizados foi a opção mais citada nas três questões. Outras ações citadas referem-se ao controle de circulação de veículos em regiões centrais, à segurança de pedestres, à diminuição das distâncias entre residências e locais de emprego, às campanhas educativas e à ampliação e melhoria de estruturas como ciclovias e calçadas. Os resultados são relevantes para apoiar a tomada de decisões baseadas em evidências na gestão pública e oferecer subsídios para a elaboração de modelos computacionais com vistas à promoção da mobilidade ativa.

Abstract: This study aimed to describe a quantitative survey conducted with leaders to investigate effective and feasible actions that can be evaluated in computational models to inform policies to promote active mobility based in the city of São Paulo, Brazil. In 2022, an online survey was conducted during the Health Survey in São Paulo (Physical Activity and Environment study), which is monitored by representatives of nongovernmental organizations and public and private sector managers. A questionnaire was elaborated with three questions with 13 alternative answers about actions to promote walking and/or cycling. Leaders should select up to three alternatives based on their potential regarding: (1) effectiveness; (2) feasibility or ease of implementation; and (3) desire to verify tests in computational models to inform policies. The survey was answered by 18 leaders from 16 institutions, comprising 13 (72%) women and 12 (67%) representatives of the third sector, whose average age was 48 years and all had complete higher education. Reducing the speed of motor vehicles was the most cited option in all three questions. Other actions mentioned refer to controlling the traffic of vehicles in central areas, improving pedestrian safety, reducing the distances between homes and places of employment, conducting educational campaigns, and expanding and enhancing structures such as bicycle lanes and sidewalks. The results are relevant to support evidence-based decision-making in public management and to provide subsidies for the development of computational models with a view to promoting active mobility.

Resumen: Este estudio tuvo como objetivo presentar una encuesta cuantitativa realizada con líderes para investigar las acciones efectivas, viables y que puedan probarse en modelos informáticos para orientar las políticas que promuevan la movilidad activa en la ciudad de São Paulo, Brasil. En 2022 se realizó una encuesta en línea en el contexto de la Encuesta de Salud de São Paulo (Actividad Física y Medio Ambiente), que es monitoreada por representantes de organizaciones no gubernamentales, gestores públicos y entidades privadas. Se elaboró un cuestionario de tres preguntas con 13 respuestas alternativas sobre acciones para promover la caminata o el uso de la bicicleta. Los líderes podían seleccionar hasta tres alternativas en función de su potencial en términos de (1) efectividad; (2) viabilidad o facilidad de implementación; y (3) deseo de verificar las pruebas en modelos informáticos para orientar las políticas. La encuesta fue respondida por 18 líderes de 16 instituciones; de los cuales 13 (72%) eran mujeres y 12 (67%) representaban el tercer sector; la edad promedio de ellos fue de 48 años y todos contaban con educación superior. Reducir la velocidad de los vehículos de motor fue la opción más citada en las tres preguntas. Otras acciones mencionadas se refieren al control de la circulación de vehículos en las regiones centrales, la seguridad de los peatones, la reducción de las distancias entre los hogares y los lugares de trabajo, las campañas educativas y la expansión y mejora de estructuras como carriles bici y aceras. Los resultados son relevantes para apoyar la toma de decisiones basada en la evidencia en la gestión pública y ofrecer subsidios para la elaboración de modelos computacionales destinados a promover la movilidad activa.

Endocytosis in anaerobic parasitic protists

The incorporation of different molecules by eukaryotic cells occurs through endocytosis, which is critical to the cell's survival and ability to reproduce. Although this process has been studied in greater detail in mammalian and yeast cells, several groups working with pathogenic protists have made relevant contributions. This review analysed the most relevant data on the endocytic process in anaerobic protists (Entamoeba histolytica, Giardia intestinalis, Trichomonas vaginalis, and Tritrichomonas foetus). Many protozoa can exert endocytic activity across their entire surface and do so with great intensity, as with E. histolytica. The available data on the endocytic pathway and the participation of PI-3 kinase, Rab, and Rho molecular complexes is reviewed from a historical perspective.

Inhibition of nitric oxide production of activated mice peritoneal macrophages is independent of the Toxoplasma gondii strain

BACKGROUND Toxoplasma gondii causes toxoplasmosis and is controlled by activated macrophages. However, infection of macrophages by tachyzoites induces TGF-β signaling (TGF-s) inhibiting nitric oxide (NO) production. NO inhibition may be a general escape mechanism of distinct T. gondii strains. OBJECTIVES To evaluate in activated macrophages the capacity of T. gondii strains of different virulence and genetics (RH, type I; ME-49, type II; VEG, type III; P-Br, recombinant) to evade the NO microbicidal defense system and determine LC3 loading to the parasitophorous vacuole. METHODS Activated peritoneal macrophages were infected with the different T. gondii strains, NO-production was evaluated by the Griess reagent, and inducible nitric oxide synthase expression, TGF-s, and LC3 localisation assayed by immunofluorescence. FINDINGS Only RH persisted in macrophages, while VEG was more resistant than P-Br and ME-49. All strains induced TGF-s, degradation of inducible nitric oxide synthase, and NO-production inhibition from 2 to 24 h of infection, but only RH sustained these alterations for 48 h. By 24 h of infection, TGF-s lowered in macrophages infected by ME-49, and P-Br, and NO-production recovered, while VEG sustained TGF-s and NO-production inhibition longer. LC3 loading to parasitophorous vacuole was strain-dependent: higher for ME-49, P-Br and VEG, lower for RH. All strains inhibited NO-production, but only RH sustained this effect probably because it persisted in macrophages due to additional evasive mechanisms as lower LC3 loading to parasitophorous vacuole. MAIN CONCLUSIONS These results support that T. gondii can escape the NO microbicidal defense system at the initial phase of the infection, but only the virulent strain sustain this evasion mechanism.

Prostaglandin A1 inhibits the replication of bovine viral diarrhea virus

ABSTRACT Bovine viral diarrhea virus can cause acute disease in livestock, leading to economic losses. We show that Prostaglandin A1 inhibits bovine viral diarrhea virus replication in Madin-Darby bovine kidney cells (94% inhibition using 5 µg/mL). Light and electron microscopy of infected cells shows that Prostaglandin A1 also prevents virus-induced vacuolization, but at higher concentrations (10 µg/mL).

Caracterização hidrológica e influência da cobertura do solo nos parâmetros de vazão do Rio das Fêmeas / Hydrological characterization and influence of the land cover on Fêmeas River flow parameters

RESUMO Nesta pesquisa realizou-se a caracterização pluvi-fluviométrica da Bacia do Rio das Fêmeas em São Desidério (BA) e avaliaram-se as modificações das vazões, considerando a presença de uma Pequena Central Hidrelétrica (PCH) e as alterações na cobertura do solo. Selecionaram-se as estações da rede da Agência Nacional de Águas (ANA) para análise dos dados históricos de vazão e precipitação (1985-2013); utilizaram-se imagens dos satélites Landsat 5 e IRS-P6 (RESOURCESAT-1) dos anos 1985, 1995, 2000, 2005, 2008, 2011 e 2012 para classificação supervisionada da cobertura do solo em duas classes distintas: áreas com vegetação natural e áreas com interferências antrópicas, cujas regiões possuíam algum tipo de uso. Além disso, foram avaliadas as alterações das vazões medianas e médias anuais antes e após a instalação da PCH. Os resultados deste trabalho mostraram que os dados anuais médios de vazão, ao longo do tempo, reduziram com uma magnitude maior que os dados médios anuais de precipitação na bacia estudada. Em relação à ocupação do solo, a área antropizada aumentou ao longo do tempo. Diante deste estudo verificou-se que a presença do reservatório da PCH possibilitou redução nos picos de vazões máximas e aumento nos valores baixos das vazões mínimas. No período pós-PCH ocorreram vazões médias e medianas inferiores ao período pré-PCH. Entretanto, estes resultados foram influenciados pela combinação do aumento das atividades antrópicas com a variação da precipitação média anual na bacia.

ABSTRACT In this research it was studied a pluvi-fluviometric characterization and the flow rates changes of Fêmeas River basin located in São Desidério (BA), considering the presence of a PCH and the cover soil alterations. Therefore the network stations of the Agência Nacional de Águas were selected to analyze the rainfalls and flows historical data (from 1985 to 2013); LandSat 5 and IRS-P6 (RESOURCESAT-1) satellite images of 1985, 1995, 2000, 2005, 2008, 2011 and 2012 years were used for land cover classification in two classes: natural; and areas with anthropic influence, in whose regions there was some kind of use; and the changes in the median and average annual flows before and after the PCH installation were evaluated. The results of this research showed that the annual average flow data over the study period reduced in a magnitude higher than the annual average rainfall data. In relation to the soil land use, the anthropic area increased over time. With this study it was found that the presence of the PCH reservoir allowed a reduction in the maximum and minimum flow rates peak. It was observed that in the post-PCH period both average and median flow rate data were lower than that those measured in the pre-PCH period. Nevertheless, these results were influenced by the combination of the human activities that increased over time and the annual average rainfall data variation in the basin.

Adamantylidene-substituted alkylphosphocholine TCAN26 is more active against Sporothrix schenckii than miltefosine

Sporotrichosis is the most frequent subcutaneous mycosis in the world and its increasing incidence has led to the search for new therapeutic options for its treatment. In this study, we demonstrated that three structural analogues of miltefosine (TCAN26, TC19, and TC70) showed inhibitory activity against Sporothrix schenckii sensu stricto and that TCAN26 was more active in vitro than miltefosine against several isolates. Scanning electron microscopy showed that S. schenckii exposure to TCAN26 resulted in cells that were slightly more elongated than untreated cells. Transmission electron microscopy showed that TCAN26 treatment induced loss of the regular cytoplasmic electron-density and altered the cell envelope (disruption of the cell membrane and cell wall, and increased cell wall thickness). Additionally, TCAN26 concentrations required to kill S. schenckii cells were lower than concentrations that were cytotoxic in mammalian cells, and TCAN26 was more selective than miltefosine. Thus, the adamantylidene-substituted alkylphosphocholine TCAN26 is a promising molecule for the development of novel antifungal compounds, although further investigations are required to elucidate the mode of action of TCAN26 in S. schenckii cells.

Portfólio Reflexivo Eletrônico: Resultados de um Projeto Piloto / Reflective e-Portfolio: Results of a Pilot Project

RESUMO Este estudo investigou a implantação de um Portfólio Reflexivo Eletrônico (PRE) nas atividades de Prática Profissional (PP), que ocorrem em ambientes internos e externos ao campus. Para avaliação, um protótipo foi instalado em netbooks e usado durante cinco meses por um grupo de estudantes e um facilitador do primeiro ciclo da Unidade Educacional de Prática Profissional (Uepp) do curso de Medicina da Universidade Federal de São Carlos (UFSCar). O estudo percorreu as seguintes etapas: levantamento dos requisitos, design e implementação do protótipo e avaliação do protótipo. Na avaliação foi feito um inquérito com aplicação de dois questionários e a realização de observações locais durante esse período. Os resultados demonstraram que a maioria dos estudantes prefere usar o PRE nas atividades internas e em grupo, mas prefere usar papel durante o atendimento aos pacientes, e que características de hardware e software do dispositivo de acesso e os diferentes ambientes de uso influenciam essa preferência.

ABSTRACT This study investigated the deployment of a Reflective e-Portfolio (REP) for Professional Practice (PP) activities, which activities occur on and off the campus. For the prototype evaluation, the e-Portfolio was installed on netbooks and used for five months by a group of students and a facilitator of the first cycle of the Educational Unit of Professional Practice (EUPP) of the UFSCar Medicine Course. The study involved the following steps: survey to establish the requirements, design and implementation of the prototype, and evaluation of the prototype. The evaluation consisted of an investigation with the application of two questionnaires and local observations conducted during that period. The results showed that most students prefer to use the REP in the internal and group activities, but prefer to use paper for patient care, and that hardware and software characteristics of the access device as well as the different environments of use influence this preference.

Trichuris trichiura in a post-Colonial Brazilian mummy

Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

Mechanisms of growth inhibition of Phytomonas serpens by the alkaloids tomatine and tomatidine

Phytomonas serpens are flagellates in the family Trypanosomatidae that parasitise the tomato plant (Solanum lycopersicum L.), which results in fruits with low commercial value. The tomato glycoalkaloid tomatine and its aglycone tomatidine inhibit the growth of P. serpens in axenic cultures. Tomatine, like many other saponins, induces permeabilisation of the cell membrane and a loss of cell content, including the cytosolic enzyme pyruvate kinase. In contrast, tomatidine does not cause permeabilisation of membranes, but instead provokes morphological changes, including vacuolisation. Phytomonas treated with tomatidine show an increased accumulation of labelled neutral lipids (BODYPY-palmitic), a notable decrease in the amount of C24-alkylated sterols and an increase in zymosterol content. These results are consistent with the inhibition of 24-sterol methyltransferase (SMT), which is an important enzyme that is responsible for the methylation of sterols at the 24 position. We propose that the main target of tomatidine is the sterols biosynthetic pathway, specifically, inhibition of the 24-SMT. Altogether, the results obtained in the present paper suggest a more general effect of alkaloids in trypanosomatids, which opens potential therapeutic possibilities for the treatment of the diseases caused by these pathogens.

PREHISTORICAL Pediculus humanus capitis INFESTATION: QUANTITATIVE DATA AND LOW VACUUM SCANNING MICROSCOPY / Infestação pré-histórica por Pediculus humanus capitis: análise quantitativa e por microscopia de varredura de baixo vácuo

A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits.

Há décadas um escalpo peruano, datado do período pré-colombiano, foi examinado por um pesquisador da Fundação Oswaldo Cruz. O Professor Olympio da Fonseca Filho descreveu lêndeas e adultos fixos a fios de cabelos e fez comentários sobre a origem da infecção por piolhos na espécie humana. Este mesmo escalpo foi enviado ao nosso laboratório e é objeto deste artigo. Sua análise mostrou maciça infestação, com nove lêndeas/cm2 em impressionante número de adultos muito bem preservados. O tempo de infestação foi estimado em cerca de nove meses antes da morte, baseado na maior distância entre lêndeas e o couro cabeludo, levando em consideração taxa média de crescimento capilar de 1 cm por mês. Um pequeno pedaço de tecido tradicional peruano foi encontrado associado ao escalpo, provavelmente pertencente ao conjunto de peças usado no ritual funerário. Aqui, apresentamos alguns aspectos morfológicos de adultos e lêndeas vizualizados por microscopia eletrônica de varredura de baixo vácuo.

Toxoplasmose e Toxoplasma gondii / Toxoplasmosis and Toxoplasma gondii

A infecção por Toxoplasma gondii é hoje muito disseminada ao redor do mundo, especialmente no Brasil. A coletânea parte da história da descoberta desse parasita e da doença por ele causada, a toxoplasmose, e visita os diferentes aspectos relacionados ao tema. São apresentados o ciclo evolutivo, a epidemiologia, o diagnóstico, o quadro clínico e o tratamento, em uma ampla revisão sobre o assunto, provavelmente a mais completa já realizada. Somente nos anos 1970 desvendou-se o ciclo de vida desse protozoário, do qual o gato é hospedeiro definitivo. Outros animais de sangue quente, entre eles o ser humano, são hospedeiros intermediários. Muitos indivíduos infectados pelo T. gondii não apresentam sintomas, mas, quando a doença se manifesta, pode ter diferentes configurações, afetando gânglios, olhos, coração, pulmões, fígado, cérebro e meninges, ou articulações. Além de uma completa revisão, a obra também traz para o leitor o que há de mais atual no conhecimento científico acerca da toxoplasmose e do T. gondii. O livro cobre praticamente todos os campos do conhecimento sobre o agente etiológico e a doença, apresentando novos aspectos, particularmente em relação à bioquímica, à interação entre o parasita e a célula hospedeira e à resposta imunológica à infecção.

Prokaryotic cells: structural organisation of the cytoskeleton and organelles

For many years, prokaryotic cells were distinguished from eukaryotic cells based on the simplicity of their cytoplasm, in which the presence of organelles and cytoskeletal structures had not been discovered. Based on current knowledge, this review describes the complex components of the prokaryotic cell cytoskeleton, including (i) tubulin homologues composed of FtsZ, BtuA, BtuB and several associated proteins, which play a fundamental role in cell division, (ii) actin-like homologues, such as MreB and Mb1, which are involved in controlling cell width and cell length, and (iii) intermediate filament homologues, including crescentin and CfpA, which localise on the concave side of a bacterium and along its inner curvature and associate with its membrane. Some prokaryotes exhibit specialised membrane-bound organelles in the cytoplasm, such as magnetosomes and acidocalcisomes, as well as protein complexes, such as carboxysomes. This review also examines recent data on the presence of nanotubes, which are structures that are well characterised in mammalian cells that allow direct contact and communication between cells.

Organização estrutural do taquizoíto de toxoplasma gondii: [revisão] / Structural organization of the tachyzoite of toxoplasma gondii: [review]

Objetivos: fazer uma revisão dos aspectos básicos da ultraestrutura do taquizoíto de Toxoplasma gondii, agente etiológico da toxoplasmose. Fonte de dados: os dados apresentados tomam como referência resultados recentes obtidos pelos principais grupos de pesquisadores no mundo, que se dedicam ao estudo do Toxoplasma gondii, incluindo-se dados do próprio grupo de autores. Síntese dos dados: os taquizoítos de Toxoplasma gondii são responsáveis pela fase aguda da infecção, penetrando ativamente, através do complexo apical, em células dos hospedeiros onde se multiplicam. São abordadas características ultraestruturais e moleculares particulares da película, do citoesqueleto, de organelas secretórias (róptrias, micronemas e grânulos densos) e não secretórias (apicoplasto) exclusivas do filo Apicomplexa, além das peculiaridades do núcleo, mitocôndria, acidocalcisomas, retículo endoplasmático e complexo de Golgi desses parasitos intracelulares. Conclusões: estas características confirmam que o sucesso nas etapas de adesão, invasão e multiplicação do parasito possui clara correlação com suas características morfofuncionais.

Aims: To review basic aspects on the ultrastructure of the tachyzoite of Toxoplasma gondii, the causative agent of toxoplasmosis. Source of data: The data presented are based on recent publications by the most distinguished research groups in the area dedicated to the study of Toxoplasma gondii, including studies from the present authors. Summary of findings: The tachyzoites are responsible for the acute phase of the infection by actively penetrating, through the parasites? apical complex, the host cells where they multiply. Both ultrastructural and molecular particularities of the pellicle, the cytoskeleton, secretory (rhoptries, micronemas and dense granules) and non secretory (apicoplast) organelles, specific to Apicomplexa phylum, besides peculiar features of the nucleus, mitochondrion, acidocalcisomes, endoplasmic reticulum and Golgi complex of these intracellular parasites. Conclusions: These characteristics confirm that the success in the process of adhesion, invasion and multiplication of this parasite is clearly correlated to its morphology.

Recordações de Carlos Chagas Filho / Memories of Carlos Chagas Filho

Recordações de Carlos Chagas Filho inaugura, o que esperamos seja seguido por outras iniciativas, publicações que testemunham e recriam pela expressão do vivido, o caleidoscópio multiforme e único de uma vida e obra exemplares. Darcy Fontoura de Almeida e Wanderley de Souza, organizadores, reuniram uma seleção muito especial de autores que descrevem e analisam as contribuições científicas de Carlos Chagas Filho, a formação do Instituto de Biofísica e a política universitária e científica brasileira, que compõem as três seções dessas Recordações. A riqueza da leitura muito se deve por terem organizadores e autores convivido de maneira mui­to especial e, em muitos casos, serem co-artífices do legado científico e institucional do homenageado. Não são recortes estanques, pois em todos os textos transbordam o afeto e o reconhecimento revelador de traços comuns e de peculiaridades do jeito de ser de Carlos Chagas Filho. Aprendemos muito sobre a construção de campos e disciplinas científicas, dos processos de consolidação de uma instituição de excelência, o Instituto de Biofísica Carlos Chagas Filho, que expandiu fronteiras e se mantém como ícone de excelência da ciência brasileira, de relações históricas e contemporâneas com o legado de Manguinhos. Deli­ciamo-nos com causos e nos comovemos com a profundidade dos afetos que envolvem essas relações e que ressoam nos sentimentos que são também nossos. Há uma evidência que unifica todos os textos: a intimidade com Carlos Chagas Filho era um encontro transformador. Ele sabia avaliar o que tinham de melhor, elevar sua auto-estima, apos­tar em seus potenciais e abrir caminhos para se realizarem profissionalmente.

Toxoplasma gondii: further studies on the subpellicular network

The association of the pellicle with cytoskeletal elements in Toxoplasma gondii allows this parasite to maintain its mechanical integrity and makes possible its gliding motility and cell invasion. The inner membrane complex (IMC) resembles the flattened membrane sacs observed in free-living protozoa and these sacs have been found to associate with cytoskeletal proteins such as articulins. We used immunofluorescence microscopy to characterise the presence and distribution of plateins, a sub-family of articulins, in T. gondii tachyzoites. A dispersed labelling of the whole protozoan body was observed. Electron microscopy of detergent-extracted cells revealed the presence of a network of 10 nm filaments distributed throughout the parasite. These filaments were labelled with anti-platein antibodies. Screening the sequenced T. gondii genome, we obtained the sequence of an IMC predicted protein with 25 percent identity and 42 percent similarity to the platein isoform alpha 1 present in Euplotes aediculatus, but with 42 percent identity and 55 percent similarity to that found in Euglena gracilis, suggesting strong resemblance to articulins.