Relevant coexpression of STMN1, MELK and FOXM1 in glioblastoma and review of the impact of STMN1 in cancer biology / Coexpressão relevante de STMN1, MELK e FOXM1 em glioblastoma e revisão do impacto de stmn1 na biologia do câncer

OBJECTIVE: To analyze the associated expression of STMN1, MELK and FOXM1 in search of alternative drugable target in glioblastoma (GBM) and to review relevant functional roles of STMN1 in cancer biology. METHOD: STMN1, MELK and FOXM1 expressions were studied by quantitative PCR and their coexpressions were analyzed in two independent glioblastoma cohorts. A review of articles in indexed journals that addressed the multiple functional aspects of STMN1 was conducted, focusing on the most recent reports discussing its role in cancer, in chemoresistance and in upstream pathways involving MELK and FOXM1. RESULTS: Significant associated expressions of MELK and FOXM1 were observed with STMN1 in GBM. Additionally, the literature review highlighted the relevance of STMN1 in cancer progression. CONCLUSION: STMN1 is very important to induce events in cancer development and progression, as cellular proliferation, migration, and drug resistance. Therefore, STMN1 can be an important therapeutic target for a large number of human cancers. In glioblastoma, the most aggressive brain tumor, the MELK/FOXM1/STMN1 presented significant associated expressions, thus pointing MELK and FOXM1 as alternative targets for therapy instead of STMN1, which is highly expressed in normal brain tissue. Continuous functional research to understand the STMN1 signaling pathway is worthwhile to improve the therapeutic approaches in cancer.

OBJETIVO: Analisar as expressões associadas de STMN1, MELK e FOXM1 na procura de alvos alternativos de tratamento em glioblastoma (GBM) e revisar os papeis funcionais relevantes de STMN1 na biologia do câncer. MÉTODO: As expressões de STMN1, MELK e FOXM1 foram estudadas por PCR quantitativo e suas coexpressões foram analisadas em dois coortes independentes de GBM. A revisão dos artigos publicados em revistas indexadas na procura dos aspectos funcionais múltiplos de STMN1 foi conduzida focando-se nos estudos mais recentes discutindo o seu papel em câncer, quimiorresistência e vias de sinalização envolvendo MELK e FOXM1. RESULTADOS: Observou-se expressões associadas significantes de MELK e FOXM1 com STMN1. Adicionalmente, a revisão da literatura salientou a relevância do STMN1 na progressão do câncer. CONCLUSÃO: STMN1 é muito importante nos eventos relacionados ao desenvolvimento e progressão do câncer, como proliferação celular, migração e resistência ao tratamento. Desta forma, STMN1 pode ser um forte alvo terapêutico em um grande número de cânceres humanos. Em GBM, o tumor cerebral mais agressivo, MELK/FOXM1/STMN1 apresentaram significativa associação em suas expressões gênicas, indicando, portanto, MELK e FOXM1 como alvos alternativos para terapia em substituição ao STMN1, que apresenta alta expressão no tecido cerebral normal. Perseverar nos estudos funcionais para o entendimento da via de sinalização do STMN1 é relevante para melhorar os esquemas terapêuticos para câncer.

Comparison of interscalene brachial plexus block and intra-articular local anesthetic administration on postoperative pain management in arthroscopic shoulder surgery / Comparação de bloqueio do plexo braquial por via interescalênica e administração de anestésico local intra-articular no manejo da dor no pós-operatório de cirurgia artroscópica do ombro / Comparación de bloqueo del plexo braquial por vía interescalénica y administración de anestésico local intraarticular en el manejo del dolor en el postoperatorio de cirugía artroscópica del hombro

BACKGROUND AND OBJECTIVES: In this study, the aim was to compare postoperative analgesia effects of the administration of ultrasound-guided interscalene brachial plexus block and intra-articular bupivacaine carried out with bupivacaine. METHODS: In the first group of patients 20 mL 0.25% bupivacaine and ultrasound-guided interscalene brachial plexus block (ISPB) were applied, while 20 mL 0.25% bupivacaine was given via intra-articular (IA) administration to the second group patients after surgery. Patients in the third group were considered the control group and no block was performed. Patient-controlled analgesia (PCA) with morphine was used in all three groups for postoperative analgesia. RESULTS: In the ISPB group, morphine consumption in the periods between 0-4, 6-12 and 12-24 postoperative hours and total consumption within 24 h was lower than in the other two groups. Morphine consumption in the IA group was lower than in the control group in the period from 0 to 6 h and the same was true for total morphine consumption in 24 h. Postoperative VASr scores in the ISPB group were lower than both of the other groups in the first 2 h and lower than the control group in the 4th and 6th hours (p < 0.05). In the IA group, VASr and VASm scores in the 2nd, 4th and 6th hours were lower than in the control group (p < 0.05). CONCLUSION: Interscalene brachial plexus block was found to be more effective than intra-articular local anesthetic injection for postoperative analgesia. .

JUSTIFICATIVA E OBJETIVOS: Comparar os efeitos na analgesia no pós-operatório da administração de bloqueio do plexo braquial por via interescalênica guiado por ultrassom e bupivacaína intra-articular, feito com bupivacaína. MÉTODOS: No primeiro grupo de pacientes, 20 mL de bupivacaína a 0,25% e bloqueio do plexo braquial por via interescalênica guiado por ultrassom (BPBI) foram administrados, enquanto 20 mL de bupivacaína a 0,25% foram administrados por via intra-articular (IA) ao segundo grupo de pacientes após a cirurgia. Os pacientes do terceiro grupo foram considerados grupo controle e nenhum bloqueio foi feito. Analgesia controlada pelo paciente (ACP) com morfina foi usada nos três grupos para analgesia pós-operatória. RESULTADOS: No grupo BPBI, o consumo de morfina nos períodos entre 0-4, 6-12 e 12-24 horas após a cirurgia e o consumo total em 24 horas foram mais baixos do que nos outros dois grupos. O consumo de morfina no grupo IA foi menor do que no grupo controle no período de 0-6 horas, como também foi menor o consumo total de morfina em 24 horas. Os escores EVAr no pós-operatório do grupo BPBI foram menores do que os escores dos dois outros grupos nas primeiras duas horas e menores do que os do grupo controle nos períodos de 4 e 6 horas (p < 0,05). No grupo IA, os escores EVAr e EVAm nos períodos de 2, 4 e 6 horas foram menores do que no grupo controle (p < 0,05). CONCLUSÃO: O bloqueio do plexo braquial por via interescalênica mostrou ser mais eficaz do que a injeção intra-articular de anestésico local para analgesia pós-operatória. .

JUSTIFICACIÓN Y OBJETIVOS: En este estudio, nuestro objetivo fue comparar en el período postoperatorio los efectos analgésicos de la administración de la bupivacaína en el bloqueo del plexo braquial por vía interescalénica guiado por ecografía y bupivacaína intraarticular. MÉTODOS: En el primer grupo de pacientes se administraron 20 mL de bupivacaína al 0,25% y se llevó a cabo el bloqueo del plexo braquial por vía interescalénica (BPBI) guiado por ecografía, mientras que al segundo grupo de pacientes se le administraron 20 mL de bupivacaína al 0,25% por vía intraarticular (IA) tras la cirugía. Los pacientes del tercer grupo fueron considerados como grupo control y en ellos no se realizó ningún bloqueo. La analgesia controlada por el paciente con morfina se usó en los 3 grupos para la analgesia postoperatoria. RESULTADOS: En el grupo BPBI, el consumo de morfina en los períodos entre 0-4, 6-12 y 12-24 h del postoperatorio y el consumo total en 24 h fueron más bajos que en los otros 2 grupos. El consumo de morfina en el grupo IA fue menor que en el grupo control en el período de 0-6 h, como también fue menor el consumo total de morfina en 24 h. Las puntuaciones EVAr en el postoperatorio del grupo BPBI fueron menores que las de los otros 2 grupos en las primeras 2 h y menores que los del grupo control en los períodos de 4 y 6 h (p < 0,05). En el grupo IA, las puntuaciones EVAr y EVAm en los períodos de 2, 4 y 6 h fueron menores que en el grupo control (p < 0,05). CONCLUSIÓN: El BPBI mostró ser más eficaz que la inyección intraarticular de anestésico local para analgesia postoperatoria. .

Children's eating behavior: comparison between normal and overweight children from a school in Pelotas, Rio Grande do Sul, Brazil / Comportamento alimentar infantil: comparação entre crianças sem e com excesso de peso em uma escola do município de Pelotas, RS

OBJECTIVE: To evaluate differences in children's eating behavior in relation to their nutritional status, gender and age. METHODS: Male and female children aged six to ten years were included. They were recruited from a private school in the city of Pelotas, Rio Grande do Sul, southern Brazil, in 2012. Children´s Eating Behaviour Questionnaire (CEBQ) subscales were used to assess eating behaviors: Food Responsiveness (FR), Enjoyment of Food (EF), Desire to Drink (DD), Emotional Overeating (EOE), Emotional Undereating (EUE), Satiety Responsiveness (SR), Food Fussiness (FF) and Slowness in Eating (SE). Age-adjusted body mass index (BMI) z-scores were calculated according to the WHO recommendations to assess nutritional status. RESULTS: The study sample comprised 335 children aged 87.9±10.4 months and 49.3% had normal weight (n=163), 26% were overweight (n=86), 15% were obese (n=50) and 9.7% were severely obese (n=32). Children with excess weight showed higher scores at the CEBQ subscales associated with "food approach" (FR, EF, DD, EOE, p<0.001) and lower scores on two "food avoidance" subscales (SR and SE, p<0.001 and p=0.003, respectively) compared to normal weight children. Differences in the eating behavior related to gender and age were not found. CONCLUSIONS: "Food approach" subscales were positively associated to excess weight in children, but no associations with gender and age were found. .

OBJETIVO: Avaliar diferenças no comportamento alimentar infantil em função do estado nutricional, do sexo e da idade. MÉTODOS: O estudo incluiu crianças na faixa de seis a dez anos, de ambos os sexos, de uma escola privada em Pelotas (RS), em 2012. Para avaliar o comportamento alimentar usaram-se as subescalas do questionário Children's Eating Behaviour Questionnaire (CEBQ): resposta à comida (FR), prazer de comer (EF), desejo de beber (DD), sobreingestão emocional (EOE), subingestão emocional (EUE), resposta à saciedade (SR), seletividade (FF) e ingestão lenta (SE). Avaliou-se o estado nutricional por meio do escore-z do IMC/idade. RESULTADOS: Participaram 335 crianças de 87,9±10,4 meses. Apresentaram eutrofia 49,3% (n=163), sobrepeso 26% (n=86), obesidade 15% (n=50) e obesidade grave 9,7% (n=32). Crianças com excesso de peso tiveram maior pontuação nas subescalas de "interesse pela comida" (FR, EF, DD, EOE, p<0,001) e menor pontuação nas subescalas de "desinteresse pela comida" (SR e SE, p<0,001 e p=0,003, respectivamente), se comparadas com as crianças com peso adequado. Não foram observadas diferenças no comportamento alimentar segundo sexo e idade. CONCLUSÕES: Observou-se que comportamentos alimentares que refletem "interesse pela comida" estão associados positivamente ao excesso de peso, mas não foi encontrada associação com o sexo e a idade da criança. .

Fatores psicossociais e socioeconômicos relacionados à insônia e menopausa: Estudo Pró-Saúde / Psychosocial and socioeconomic factors related to insomnia and menopause: Pró-Saúde Study / Factores psicosociales y socioeconómicos relacionados con el insomnio y la menopausia: Estudio Pro-Salud

Foi avaliada a associação entre menopausa e insônia e a influência de variáveis socioeconômicas e psicossociais, em estudo transversal com 2.190 funcionárias de uma universidade (Estudo Pró-Saúde), a partir de um questionário autopreenchível com variáveis sobre menopausa, insônia, transtorno mental comum, eventos de vida estressantes, apoio social e variáveis socioeconômicas. Odds ratios foram calculados por meio de regressão logística multivariada, com desfecho politômico. Após ajuste para potenciais confundidoras sociodemográficas, mulheres na menopausa há mais de 60 meses apresentaram maior chance de reportar queixas de sono frequentes (OR entre 1,53 e 1,86) do que as que estavam na menopausa há menos de 60 meses. Após os ajustes, no primeiro grupo, para as variáveis psicossociais, a magnitude dos ORs reduziu para 1,53 (IC95%: 0,92-2,52) para dificuldade em iniciar o sono, 1,81 (IC95%: 1,09-2,98) para dificuldade em manter o sono e 1,71 (IC95%: 1,08-2,73) para queixa geral de insônia. Fatores psicossociais podem mediar a manifestação da insônia em mulheres na menopausa.

This study evaluated the association between insomnia and menopausal status and the influence of socioeconomic and psychosocial variables on this association in a cross-sectional analysis of 2,190 university employees (the Pró-Saúde Study). A self-administered questionnaire was used, covering menopausal status, complaints of insomnia, common mental disorders, stressful life events, social support, and socioeconomic variables. Odds ratios were calculated using logistic regression with a polytomous outcome. After adjusting for potential socio-demographic confounders, women who had entered menopause more than 60 months previously were more likely to report complaints with sleep (OR 1.53-1.86) as compared to women in menopause for less than 60 months. After adjusting for psychosocial variables, in the first group the ORs decreased to 1.53 (95%CI: 0.92-2.52) for difficulty initiating sleep, 1.81 (95%CI: 1.09-2.98) for difficulty maintaining sleep, and 1.71 (95%CI: 1.08-2.73) for general complaints of insomnia. Psychosocial factors can mediate the manifestation of insomnia among menopausal women.

En este estudio se evaluó la asociación entre insomnio y menopausia y la influencia de las variables socioeconómicas y psicosociales, en un estudio transversal con 2.190 mujeres de una universidad (Estudio Pro-Salud), a partir de un cuestionario autoadministrado con variables de la menopausia, insomnio, trastornos mentales, situaciones de estrés vital, apoyo social y variables socioeconómicas. Se calcularon los odds ratio mediante regresión logística multivariante con desenlace politómico. Después de ajustar por factores de confusión sociodemográficos potenciales, las mujeres menopáusicas desde hace más de 60 meses fueron más propensas a reportar quejas frecuentes de sueño (OR entre 1,53 y 1,86) que las menopáusicas hace menos de 60 meses. Después de los ajustes, en el primer grupo, para las variables psicosociales la magnitud de los OR se redujo a 1,53 (IC95%: 0,92-2,52) para la dificultad para iniciar el sueño, un 1,81 (IC95%: 1,09-2,98) para mantener el sueño y un 1,71 (IC95%: 1,08-2,73) para las quejas de insomnio en general. Los factores psicosociales pueden mediar en la manifestación del insomnio en las mujeres menopáusicas.

Predictors of Success in the Treatment of Obstructive Sleep Apnea Syndrome with Mandibular Repositioning Appliance: A Systematic Review

Introduction Obstructive sleep apnea syndrome affects up to 4% of middle-aged men and 2% of adult women. It is associated with obesity. Objective The objective of this article is to review the literature to determine which factors best correlate with treatment success in patients with obstructive sleep apnea syndrome treated with a mandibular repositioning appliance. Data Synthesis A search was performed of the PubMed, Cochrane, Lilacs, Scielo, and Web of Science databases of articles published from January 1988 to January 2012. Two review authors independently collected data and assessed trial quality. Sixty-nine articles were selected from PubMed and 1 from Cochrane library. Of these, 42 were excluded based on the title and abstract, and 27 were retrieved for complete reading. A total of 13 articles and 1 systematic review were considered eligible for further review and inclusion in this study: 6 studies evaluated anthropomorphic and physiologic factors, 3 articles addressed cephalometric and anatomic factors, and 4 studies evaluated variables related to mandibular repositioning appliance design and activation. All the studies evaluated had low to moderate methodologic quality and were not able to support evidence on prediction of treatment success. Conclusion Based on this systematic review on obstructive sleep apnea syndrome treatment, it remains unclear which predictive factors can be used with confidence to select patients suitable for treatment with a mandibular repositioning appliance. .

Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3). CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state. .

A likely role for a novel PH-domain containing protein, PEPP2, in connecting membrane and cytoskeleton

PH domains (pleckstrin homology) are well known to bind membrane phosphoinositides with different specificities and direct PH domain-containing proteins to discrete subcellular apartments with assistances of alternative binding partners. PH domain-containing proteins are found to be involved in a wide range of cellular events, including signalling, cytoskeleton rearrangement and vesicular trafficking. Here we showed that a novel PH domain-containing protein, PEPP2, displayed moderate phosphoinositide binding specificity. Full length PEPP2 associated with both plasma membrane and microtubules. The membrane-associated PEPP2 nucleated at cell-cell contacts and the leading edge of migrating cells. Overexpression of PEPP2 increased membrane microviscosity, indicating a potential role of PEPP2 in regulating function of membrane and microtubules.

Search of new Antimitotics compounds from the Cuban flora / Búsqueda de nuevos compuestos con actividad antimitótica en la flora cubana

The main objective of anti-carcinogenic chemotherapy is to stop uncontrolled cellular proliferation. This has prompted us to begin a systematic survey of new effective inhibitors with ability to react with cytoskeletal components and arrest living, dividing cells. Even for traditional populations herbs-consuming, encouraging the use of species with chemopreventive actions could be helpful as part of life expectancy improvement strategies. Herbal products have significantly lower costs, exhibit little or no toxicity during long-term oral administration and are relatively available at large scale. Current work involved the screening of 85 extracts from Cuban medicinal plants, selected on the basis of traditional use, ethnobotanics and pharmacological information (antiparasitic, antitumour, abortive, etc.). Antitubulinic activity in the hydroalcoholics extracts was evaluated by using a modified version of the conventional turbidity assay of tubulin assembly/ disassembly. The activity limits of the news isolated antitubulin agents were thoroughly investigated. According to the presented results, the extracts displaying the highest antitubulinic activity were Tamarindus indica L., Lawsonia inermes L and Xanthium strumarium L.

Detener la proliferación celular es el principal propósito de la quimioterapia anticarcinogénica. Para ello se ha realizado una búsqueda a partir de fuentes naturales de nuevos inhibidores efectivos que reaccionen con los componentes del citoesqueleto y puedan detener la división celular. En poblaciones que tradicionalmente utilizan plantas medicinales se estimula el uso de aquellas especies con acción quimiopreventivas como parte de una estrategia que contribuya a la calidad de vida. Los productos herbarios tienen costos significativamente más bajos, exhiben poca o ninguna toxicidad durante la administración oral a largo plazo y están al alcance de todos. Nuestro trabajo consistió en realizar un tamizaje de 85 extractos de plantas medicinales cubanas seleccionadas en base al uso tradicional, en las encuestas etnobotánicas e información farmacológica (actividad antiparasitaria, antitumoral, abortiva, etc). La actividad antitubulínica fue evaluada mediante una versión modificada del ensayo turbimétrico del ensamblaje/desensamblaje de la tubulina. Se determinó la actividad límite de los nuevos agentes antitubulínicos siendo los extractos de Tamarindus indica L., Lawsonia inermes L and Xanthium strumarium L. los de mejor actividad antitubulínica según las condiciones ensayadas.

Does usnic acid affect microtubules in human cancer cells? / O ácido úsnico pode afetar microtúbulos em células cancerosas humanas?

Usnic acid, a lichen metabolite, is known to exert antimitotic and antiproliferative activities against normal and malignant human cells. Many chemotherapy agents exert their activities by blocking cell cycle progression, inducing cell death through apoptosis. Microtubules, protein structure involved in the segregation of chromosomes during mitosis, serve as chemotherapeutical targets due to their key role in cellular division as well as apoptosis. The aim of this work was to investigate whether usnic acid affects the formation and/or stabilisation of microtubules by visualising microtubules and determining mitotic indices after treatment. The breast cancer cell line MCF7 and the lung cancer cell line H1299 were treated with usnic acid 29 µM for 24 hours and two positive controls: vincristine (which prevents the formation of microtubules) or taxol (which stabilizes microtubules). Treatment of MCF7 and H1299 cells with usnic acid did not result in any morphological changes in microtubules or increase in the mitotic index. These results suggest that the antineoplastic activity of usnic acid is not related to alterations in the formation and/or stabilisation of microtubules.

O ácido úsnico, um metabólito de liquens, é conhecido por sua atividade antimitótica e antiproliferativa em células humanas normais e malignas. Muitos quimioterápicos exercem suas atividades bloqueando a progressão do ciclo celular e induzindo morte celular por apoptose. Os microtúbulos, estruturas protéicas envolvidas na segregação dos cromossomos durante a mitose, servem como alvo quimioterapêutico devido ao seu importante papel tanto na divisão celular quanto nos mecanismos de morte celular por apoptose. O objetivo deste trabalho foi investigar se o ácido úsnico afeta a formação e/ou estabilização dos microtúbulos, a partir da visualização de microtúbulos e determinação de índices mitóticos após o tratamento. Células de câncer de mama MCF7 e de câncer de pulmão H1299 foram tratadas por 24 horas com 29 µM de ácido úsnico e dois controles positivos: vincristina (que impede a formação de microtúbulos) e taxol (que estabiliza microtúbulos). O tratamento das células MCF7 e H1299 com o ácido úsnico não resultou em aumento do índice mitótico. Os resultados sugerem que a atividade antineoplásica do ácido úsnico não está relacionada a alterações na formação e/ou estabilização de microtúbulos.

Transferrin uptake may occur through detergent-resistant membrane domains at the cytopharynx of Trypanosoma cruzi epimastigote forms

Uptake of transferrin by epimastigote forms of the protozoan Trypanosoma cruzi occurs mainly through a cytostome/ cytopharynx, via uncoated endocytic vesicles that bud off from the bottom of the cytopharynx. We have here examined whether detergent-resistant membrane (DRM) domains might be involved in this process. Purified whole cell membrane fractions were assayed for cholesterol levels and used in dot blot analyses. Detergent-resistant membrane markers (cholera B toxin and anti-flotillin-1 antibody) presented positive reaction by dot blots in cholesterol-rich/ protein-poor membrane sub-fractions. The positive dot blot fraction was submitted to lipid composition analysis, showing composition similar to that of raft fractions described for other eukaryotic cells. Immunofluorescence assays allowed the localization of punctual positive signal for flotillin-1, matching the precise cytostome/ cytopharynx location. These data were confirmed by immunofluorescence assays with the co-localization of flotillin-1 and the transferrin uptake site. Our data suggest that DRM domains occur and are integrated at the cytostome/ cytopharynx of T. cruzi epimastigotes, being the main route for transferrin uptake.

Association of rotavirus viroplasms with microtubules through NSP2 and NSP5

Rotavirus replication and virus assembly take place in electrodense spherical structures known as viroplasms whose main components are the viral proteins NSP2 and NSP5. The viroplasms are produced since early times after infection and seem to grow by stepwise addition of viral proteins and by fusion, however, the mechanism of viropIasms formation is unknown. In this study we found that the viroplasms surface colocalized with microtubules, and seem to be caged by a microtubule network. Moreover inhibition of microtubule assembly with nocodazole interfered with viroplasms growth in rotavirus infected cells. We searched for a physical link between viroplasms and microtubules by co-immunoprecipitation assays, and we found that the proteins NSP2 and NSP5 were co-immunoprecipitated with anti-tubulin in rotavirus infected cells and also when they were transiently co-expressed or individually expressed. These results indicate that a functional microtubule network is needed for viroplasm growth presumably due to the association of viroplasms with microtubules via NSP2 and NSP5.

Secretory organelles of pathogenic protozoa

Processos de secreção celular desempenham papel relevante na biologia e no ciclo de vida de protozoários patogênicos. A presente revisão analisa, sob uma perspectiva de biologia celular, o processo de secreção em (a) micronemas, roptrias e grânulos densos encontrados em membros do grupo Apicomplexa, onde essas estruturas participam da penetração do protozoário no interior da célula hospedeira, na sua sobrevivência intravacuolar e no posterior egresso da célula hospedeira, (b) a fenda de Maurer, encontrada em Plasmodium, uma estrutura envolvida na secreção de proteínas sintetizadas pelo protozoário intravacuolar e transportada, através de vesículas, para a superfície do eritrócito, (c) a secreção de macromoléculas na bolsa flagelar de tripanosomatídeos, e (d) a secreção de proteínas que fazem parte da parede cística de Giardia e Entamoeba e que se concentram nas vesículas de encistamento.

Abnormal spindle orientation during microsporogenesis in an interspecific Brachiaria ( Gramineae ) hybrid

This paper reports a case of abnormal spindle orientation during microsporogenesis in an interspecific hybrid of the tropical grass Brachiaria. In the affected plant, prophase I was normal. In metaphase I, bivalents were regularly co-oriented but distantly positioned and spread over the equatorial plate. In anaphase I, chromosomes failed to converge into focused poles due to parallel spindle fibers. As a consequence, in telophase I, an elongated nucleus or several micronuclei were observed in each pole. In the second division, the behavior was the same, leading to polyads with several micronuclei. A total of 40 percent of meiotic products were affected. The use of this hybrid in production systems needing good-quality seeds is discussed.

Microtubule cytoskeleton distribution using fluorescent taxoid in tetratrichomonas didelphidis

Tetratrichomonas didelphidis is a flagellated protozoan found in the intestine of opossums. The specimens were stained by the Giemsa method and by FLUTAX-2, an active fluorescent derivative of Taxol which binds to the ab-tubulin polimerized of microtubules of cells. Giemsa stain revealed the morphological features of trichomonads such as four anterior flagella, undulating membrane, axostyle and posterior flagellum. An intense fluorescence was observed in living trophozoites of T. didelphidis and Trichomonas vaginalis (used as control), incubated with FLUTAX-2. An analysis of the composition of the cytoskeleton of T. didelphidis will contribute to understanding the cellular morphology of the parasites. Key words: Tetratrichomonas didelphidis, microtubule cytoskeleton, fluorescent taxoid.

Perspective of a new diagnostic for human trichomonosis

Several diagnostic techniques have been employed for the detection of Trichomonas vaginalis. Microtubules constitute the cytoskeleton in eukaryotic cells and are sensitive to antimitotic drugs, such as Taxol (paclitaxel). We used FLUTAX a fluorescent taxoid - to analyze the microtubule distribution in living trophozoites of T. vaginalis in urine and in vaginal discharge. A high intensity of fluorescence was observed in living T. vaginalis, epithelial cells and leukocytes present in urine and vaginal discharge. Our preliminary results show the perspective of a new diagnostic technique for trichomonosis and will contribute to the understanding of the cytoskeleton of T. vaginalis

Behaviour of microtubules in cells infected with Toxoplasma gondii

Toxoplasma gondii proliferates within the parasitophorous vacuole of the host cell. Simultaneously with parasite division and vacuolar development, lipids traffic and change in the spatial distribution of organelles of the host cell cytoplasm occur. Using fluorescence microscopy, and antibodies recognizing tubulin, we showed that microtubules change their distribution during host cell infection by tachyzoites of T. gondii. In addition, transmission electron microscopy of thin sections and replicas of partially extracted cells showed that host cell microtubules concentrate around the parasitophorous vacuole. Such microtubules distribution was evident in early infection times and was more prominent after 24 h of infection, when parasitophorous vacuole was completely surrounded by microtubules. However, the meshwork microtubule filaments became slack or absent after 72 h of infection of host cell. Colchicine and taxol treatment altered the shape of the parasitophorous vacuole containing tachyzoites. These observations suggest a close association between microtubules and intravacuolar development of parasites.

Cultivo y Caracterización In Vitro de una Línea Celular de Fibroblastos Gingivales Humanos / In vitro culture and characterization of a cell line of human gingival fibroblasts

The main goal is to establish a cellular line of fibroblast which come from human gingival tissue, identifying its morphologic featores. Samples were taken from gum of healthy patients without medical antecedents. Three females and three male were selected. Ages were between 16 and 30 years old. A sample of 0,5 cm² of gum was obtained to take it to a cellular growth environment. Cultures were incobated at 37C, CO² atmosphere at 5% for ten (10) days. Samples were observed daily with inverted light Microscope Olimpus II. At 6th day growth of fusiform cells was observed; their morphology was in coincidence with that of the fibroblasts, At 18th day a monolayer of 100% purity was observed. The cellular line was preserved and stored by freezing in liquid nitrogen.

The nucleation of microtubules in Aspergillus nidulans germlings

Microtúbulos säo filamentos compostos por dímeros das tubulinas alfa e beta e têm uma variedade de funçöes nas células vivas. Em fungos, os corpúsculos polares dos fusos säo geralmente considerados os centros organizadores dos microtúbulos. Com o objetivo de contribuir para uma melhor compreensäo dos processos de nucleaçäo dos microtúbulos no fungo filamentoso A. nidulans, nós utilizamos a droga antimicrotúbulo Benomil em experimentos de bloqueio e liberaçäo para depolimerizar e repolimerizar os microtúbulos. Após 20 segundos de reincubaçäo em meio sem Benomil, pequenos microtúbulos foram formados a partir de pontos distribuídos pela célula, sugerindo que os pontos de nucleaçäo de microtúbulos säo aleatoriamente distribuídos pelas hifas de A. nidulans. Como em A. nidulans o movimento nuclear é dependente de microtúbulos foi analisado se mutantes defectivos na distribuiçäo de núcleos ao longo das hifas (mutantes nud) possuíam algum defeito evidente nos microtúbulos. Os microtúbulos citoplasmáticos, dos fusos e astrais estäo presentes e aparentam-se normais em todos os mutantes nud, mas foi observada uma pequena distorçäo na proporçäo de fusos mitóticos longos e curtos nestes mutantes, comparados com o controle. Isto sugere que alguns núcleos de mutantes nud näo alcançam a fase tardia da divisäo celular, em temperatura näo restritiva.

Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat

Taiep is an autosomal recessive mutant rat that shows a highly hypomyelinated central nervous system (CNS). Oligodendrocytes accumulate microtubules (MTs) in association with endoplasmic reticulum (ER) membranes forming MT-ER complexes. The microtubular defect in oligodendrocytes, the abnormal formation of CNS myelin and the astrocytic reaction were characterized by immunocytochemical and ultrastructural methods during the first year of life. Optic nerves of both control and taiep rats were processed by the immunoperoxidase method using antibodies against tubulin, myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP). Taiep oligodendrocytes are strongly immunoreactive against tubulin, indicative of a significant accumulation of microtubules. Early differentiated oligodendrocytes observed with electron microscopy show that MT-ER complexes are mainly present in the cell body. This defect increases during the first year of life; oligodendrocytes show large MT-ER complexes projected within oligodendrocyte processes. Using anti-MBP, there was a progressive reduction of immunolabeling in the myelin sheaths as taiep rats grew older. Ultrastructural analysis revealed severely dysmyelinated axons with a frequently collapsed periaxonal collar. However, through age the myelin sheath became gradually infiltrated by MTs, suggesting their contribution to premature loss of myelin in the taiep rat. Axons of one-year-old taiep rats were severely demyelinated. Modifications in astrocytes revealed by the GFAP antibody showed a strong hypertrophy with increased immunostaining in their processes. As demyelination of axons progressed, taiep rats developed a strong astrogliosis. The present findings suggest that in taiep rats the early abnormal myelination of axons affects the adequate maintenance of myelin, leading to a progressive loss of myelin components and severe astrogliosis, features that should be considered in the pathogenesis of dysmyelinating diseases

The anthelmintic albendazole affects in vivo the dynamics and the detyrosination-tyrosination cycle of rat brain microtubules

Albendazole (ABZ) is an anthelmintic benzimidazole drug widely used in human and veterinary medicine. ABZ has binding affinity to both mammalian and helminth parasite tubulin. In the current work, we have performed in vitro assays and in vivo experiments in which rats were given ABZ orally to better characterize the action of the drug on the polymerization of rat brain microtubules and on the detyrosination/tyrosination cycle that occurs on the COOH-terminal end of alpha-tubulin. The results showed that ABZ inhibits brain microtubule polymerization in vitro, and significantly delayed microtubule assembly in vivo. The tyrosination reaction cycle was not affected in vitro; however, in rats to which the drug was administered orally, the levels of in vitro tyrosination were reduced when compared to the controls with mock treatment. These results suggest that this apparent inhibition would be due to a decrease in the amount of substrate caused by the depolymerizing effect of ABZ and the subsequent tyrosination in the intact brain with endogenous tyrosine. In conclusion, ABZ strongly affects tubulin dynamics both in vivo and in vitro. The outcome of these experiments is a contribution to the understanding of the molecular mechanisms involved in the antimicrotubular action of benzimidazole compounds.