Neutrophil-Leishmania interaction during the initial phase of Leishmania infantum infection in dogs

A leishmaniose canina (LCan) é uma doença zoonótica causada pelo protozoário Leishmania infantum e transmitida por insetos do género Phlebotomus e Lutzomyia, respetivamente no Velho e Novo Mundos. Trata-se de uma doença grave, sistémica e potencialmente fatal. Embora estejam disponíveis algumas medidas profiláticas e terapêuticas, a sua eficácia é questionável. Apesar dos neutrófilos (PMN) serem a primeira linha de defesa do organismo, fagocitando rapidamente o parasita após inoculação, os macrófagos (MØ) são as células hospedeiras definitivas, na medida em que suportam a sua multiplicação e disseminação. Este trabalho teve como objetivos identificar os mecanismos efetores ativados pelos PMN em resposta à exposição ao parasita e o impacto da interação PMN-MØ na fase inicial da infeção canina, determinando a sua contribuição no controlo da infeção ou, pelo contrário, no estabelecimento da doença clínica. Foram selecionados animais clinica e analiticamente saudáveis que testaram negativamente para as principais patologias infeciosas e parasitárias e estabeleceram-se culturas PMN-Leishmania. Verificou-se por citometria e observação microscópica que promastigotas de L. infantum foram eficazmente fagocitados por PMN na maioria dos canídeos avaliados, activando os mecanismos oxidativos (produção de superóxido) e não oxidativos (exocitose de elastase neutrofílica), mas prevenindo a libertação de armadilhas extracelulares neutrofílicas (neutrophil extracelular traps, NET). Para além disso, promastigotas e sobrenadantes de cultura induziram a migração de PMN, mas o contacto prévio com Leishmania inibiu a quimiotaxia, o que contribui para a retenção dos PMN no local da inoculação. A interação com o parasita teve um impacto negativo na viabilidade dos PMN, tendo induzido a necrose secundária. A interação PMN-parasita resultou numa diminuição da viabilidade parasitária, embora alguns promastigotas intracelulares tenham sobrevivido e mantido a capacidade de proliferar, assegurando o estabelecimento da infeção. MØ diferenciados a partir de monócitos sanguíneos sofreram alterações morfológicas importantes com o intuito de conter o parasita e também libertaram Histona H1, cujo efeito leishmanicida não foi ainda provado em promastigotas de L. infantum. A transferência do parasita para os MØ foi confirmada por citometria em co-culturas de MØ+PMN infetados aos quais foram removidos os parasitas extracelulares. A observação microscópica destas coculturas mostrou que a eferocitose de PMN infetados e provavelmente a fagocitose de parasitas libertados por PMN apoptóticos são importantes na transferência do parasita para a célula hospedeira definitiva. Inesperadamente, a interação PMN-MØ ativou a produção de óxido nítrico e induziu a libertação de NET, o que pode contribuir para a contenção do parasita e para o controlo da infeção numa fase precoce. Os resultados obtidos ampliam o conhecimento da infeção por L. infantum no cão e podem contribuir para o desenvolvimento de novas ferramentas terapêuticas e profiláticas que conduzam à redução acentuada da LCan.Canine leishmaniosis (CanL) is a zoonotic disease caused by the protozoan Leishmania infantum transmitted by insects of the genus Phlebotomus and Lutzomyia in the Old and New Worlds, respectively. It is a severe, systemic and potentially fatal disease. Despite the availability of some prophylactic and therapeutic tools, their effectiveness is questionable. Although neutrophils (PMN) are the first line of defense of the organism, rapidly phagocytizing the parasite after inoculation, macrophages (MØ) are the definitive host cells, supporting their multiplication and spread. This study aimed to identify the effector mechanisms activated by PMN in response to L. infantum promastigotes and the impact of PMN-MØ interaction in the initial phase of canine infection by determining its contribution to infection control or, on the contrary, the establishment of clinical disease. Clinically and analytically healthy animals who tested negative for the main infectious and parasitic diseases were selected and PMN-Leishmania cultures were established. It was found by flow cytometry and microscopic observation that L. infantum promastigotes are efficiently phagocytized by PMN in the majority of the dogs, activating oxidative (superoxide production) and non-oxidative (neutrophil elastase exocytosis) mechanisms, but preventing the release of neutrophil extracellular traps (NET). Furthermore, promastigotes and culture supernatants induced PMN migration, but the prior contact with Leishmania inhibited chemotaxis, which contributes to PMN retention at the inoculation site. The interaction with the parasite had a negative impact on PMN viability, promoting secondary necrosis. PMN-parasite interaction resulted in a decrease in parasite viability, although some intracellular promastigotes survived and maintained their proliferative capacity, contributing to the establishment of the infection. MØ differentiated from blood monocytes underwent major morphological changes in order to contain the parasite and also released Histone H1, but its leishmanicidal effect was not yet proven in L. infantum promastigotes. Parasite transfer to MØ was confirmed by flow cytometry in co-cultures of MØ-infected PMN whose extracellular parasites were removed. The microscopic observation of these co-cultures showed that infected PMN efferocytosis and probably phagocytosis of parasites released from apoptotic PMN are crucial for parasite transfer to the definitive host cell. Unexpectedly, PMN-MØ interaction activated nitric oxide production and induced NET release, which can contribute to parasite containment and to the early control of the infection. These findings broaden the knowledge of L. infantum infection in the dog and can shed light in the design of new therapeutic and prophylactic tools, leading to a marked reduction in CanL

Active methodologies in incoming programming classes

Innovative approaches in teaching programming have been required to improve the success of incoming programming students. This work presents the initial results of a teaching strategy implemented in the Algorithms subject of a Computer Science course. Ninety-five students, enrolled in this subject during the first semester of the course, participated in the research. The reported activity is related with active methodologies of teaching and Problem-Based Learning, being developed on the first day of class in groups of up to five students. The activity was based in two actions: 1) answering a questionnaire associating computing elements to daily life routines; and, 2) even without programming concepts knowledge, develop a smartphone application. Each group received a questionnaire containing 19 questions, divided into four blocks. What can be perceived with the accomplishment of this work, was the enthusiasm, motivation and engagement of the students who, even being unknown from each other, organized themselves in the groups and researched the necessary strategies to complete the challenge. The teacher acted as an advisor in the teaching process, conducting the experiment in order to lead students to find the solution.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Projects Scopes: UIDB/05757/2020 and UIDB/00319/2020.info:eu-repo/semantics/publishedVersio

Using the methodology problem-based learning to teaching programming to freshman students

This work registers the initial results of a teaching strategy implemented with students entering the Algorithms discipline with a higher degree in Computing. This discipline offered to first-year students records cases of dropout and evasion. Thus, it is necessary to implement teaching strategies to provide engagement, interest, and motivation with the subjects worked on. The main objective is apply an active methodology problem-based learning in programming teaching. In this work participated 177 students in the years 2019-2 (47), 2020-1/2020-2 (83), and 2021-2 (47), enrolled in the first period of the course. The methodology adopted for the development of this study consisted of: use of questionnaires to measure prior knowledge about computing concepts; group discussion of the answers recorded in the questionnaire; development of an APP for smartphone; use of the PBL (Problem-based learning) methodology as a learning strategy. It is an activity related to the active teaching and learning methodology of problem-based learning that is being developed on the first day of class in groups of up to five students. The strategy consisted of two actions: 1) answering a questionnaire associating everyday computing elements; and 2) even though the programming concepts were not presented, the groups were challenged to develop a smartphone application. Each group received a questionnaire containing 19 questions divided into four blocks. What can be seen from the completion of this work was the enthusiasm, motivation, and engagement of the students, who, even though they were newcomers, organized themselves into groups and researched the necessary strategies to complete the challenge. When measuring the knowledge obtained through the application of a questionnaire relating to the content (with the participation of 62% of students), it was found that 81% of the participants obtained the necessary grade for approval of that content. Following the strategy of an active methodology of learning and teaching that favors the protagonism and autonomy of the student, we concluded that strategy was benefic for to the students, and the teacher acted as a guide in the teaching process, directing what should be researched to find the solution and serving as a tutor in the resolution of the problem presented. Preliminarily, part of this study was presented at the 2nd International Computer Programming Education Conference.info:eu-repo/semantics/publishedVersio

Seroprevalence of SARS-CoV-2 in Client-Owned Cats from Portugal

Funding Information: The participation of T.L.M. was supported by the projects UIDB/CVT/00772/2020 and LA/P/0059/2020, funded by the Portuguese Foundation for Science and Technology (FCT). The participation of M.A.P was supported by Global Health and Tropical Medicine (GHTM) under the project UID/04413/2020 and by the Centre for Natural Resources, Environment and Society (CERNAS) through the project UIDB/00681/2020, both founded by FCT, and by the Instituto Politécnico de Viseu (IPV) through the project Biossegurança: um passo firme na melhoria de um futuro incerto. Ref. BiossAPESPCall2. The participation of H.V. was supported by the Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB) through the project UIDB/04033/2020 and by CERNAS through the project UIDB/00681/2020, both funded by FCT, and by IPV through the project Biossegurança: um passo firme na melhoria de um futuro incerto. Ref. BiossAPESPCall2. Publisher Copyright: © 2022 by the authors.The close contact between humans and domestic cats raises concerns about the potential risks of SARS-CoV-2 transmission. Thus, this study aims to investigate anti-SARS-CoV-2 seroprevalence in client-owned cats from Portugal and evaluate the infection risk of cats that maintain contact with human COVID-19 cases. A total of 176 cats, belonging to 94 households, were sampled. Cat owners answered an online questionnaire, and cats were screened for antibodies against SARS-CoV-2 using a commercial ELISA. Twenty (21.3%) households reported at least one confirmed human COVID-19 case. Forty cats (22.7%) belonged to a COVID-19-positive and 136 (77.3%) to a COVID-19-negative household. The seroprevalences of cats from COVID-19-positive and -negative households were 5.0% (2/40) and 0.7% (1/136). The two SARS-CoV-2-seropositive cats from COVID-19-positive households had an indoor lifestyle, and their owners stated that they maintained a close and frequent contact with them, even after being diagnosed with COVID-19, pointing towards human-to-cat transmission. The SARS-CoV-2-seropositive cat from the COVID-19-negative household had a mixed indoor/outdoor lifestyle and chronic diseases. Owners of the three SARS-CoV-2-seropositive cats did not notice clinical signs or behavior changes. This study highlights the low risk of SARS-CoV-2 transmission from COVID-19-positive human household members to domestic cats, even in a context of close and frequent human–animal contact.publishersversionpublishe

Intervenção psicoeducativa na prevenção do stress na infância: a formação de educadores

A profissionalidade docente, no quadro dos processos de ensino-aprendizagem, constitui um desafio ao nível da formação especializada, especialmente numa perspetiva life span. Este estudo tem como objetivo geral identificar o tipo de intervenção psicoeducativa que permite atuar ao nível da prevenção do stress. Os resultados mostraram existir correlações moderadas entre as situações indutoras de stress de Causas Internas Psicossociais e as Causas Externas de Componente Familiar. Também as práticas educativas atentas à Cooperação Escola-Família estão correlacionadas com as Atividades de Prevenção das situações indutoras de stress na infância. São recomendados programas de intervenção psicoeducativa na formação de Educadores.publishe

New Insights on Innate Immune Response by Blood Macrophages and Liver Kupffer Cells to Leishmania infantum Parasites

Funding Information: Funding: This study was supported by FCT-Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and PTDC/CVT-CVT/0228/2020, and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.L. infantum is the aetiological agent of zoonotic visceral leishmaniasis (ZVL), a disease that affects humans and dogs. Leishmania parasites are well adapted to aggressive conditions inside the phagolysosome and can control the immune activation of macrophages (MØs). Although MØs are highly active phagocytic cells with the capacity to destroy pathogens, they additionally comprise the host cells for Leishmania infection, replication, and stable establishment in the mammal host. The present study compares, for the first time, the innate immune response to L. infantum infection of two different macrophage lineages: the blood macrophages and the liver macrophages (Kupffer cells, KC). Our findings showed that L. infantum takes advantage of the natural predisposition of blood-MØs to phagocyte pathogens. However, parasites rapidly subvert the mechanisms of MØs immune activation. On the other hand, KCs, which are primed for immune tolerance, are not extensively activated and can overcome the dormancy induced by the parasite, exhibiting a selection of immune mechanisms, such as extracellular trap formation. Altogether, KCs reveal a different pattern of response in contrast with blood-MØs when confronting L. infantum parasites. In addition, KCs response appears to be more efficient in managing parasite infection, thus contributing to the ability of the liver to naturally restrain Leishmania dissemination.publishersversionpublishe

A “LINGUAGEM DE INSERÇÃO” NO MATERIAL IMPRESSO PARA EDUCAÇÃO A DISTÂNCIA

This paper studies the language of printed material developed for Distance Learning, in Fundação Universidade do Tocantins (Unitins), focosing its attention in dialogue language and the language as an interaction process (Bakhtin), repertoire (Paulo Freire), fictional professor and “language of integration” (from the Literary Theory), and virtual student (Pierre Lévy). The aim is to design, from these notions, a concept of EaD-Unitins language, considering them in a perspective which holds elements from Literary Theory and the process of virtualization, according to Pierre Lévy.En este trabajo se estudia el lenguaje de material impreso desarrollado para la Fundación de Aprendizaje a Distancia en la Universidad de Tocantins (Unitins) focosing excelente atención al diálogo en el lenguaje y el lenguaje de un proceso de interacción (Bajtín), el repertorio (Paulo Freire), profesor de ficción y el lenguaje "de la integración "(de la Teoría de la Literatura), y virtual estudiante (Pierre Lévy). El objetivo es diseñar, a partir de estas nociones, el concepto de DE-Unitins lenguaje, en una perspectiva Teniendo en cuenta los que tiene elementos de la Teoría de la Literatura y el proceso de virtualización, según Pierre Lévy.Este artigo trata da linguagem do material impresso produzido para a Educação a Distância, na Fundação Universidade do Tocantins (Unitins), tendo como focos a linguagem dialógica e a linguagem como processo interação (Bakhtin), a ideia de repertório (Paulo Freire), professor fictício e “linguagem de inserção” (noções da Teoria da Literatura) e aluno virtual (Pierre Lévy). O objetivo é construir, a partir dessas noções, um conceito de linguagem da EaD-Unitins, considerando-as numa perspectiva que envolve elementos da Teoria da Literatura e o processo de virtualização, segundo o compreende Pierre Lévy

Prognostic Factors and Life Expectancy in Canine Leishmaniosis

Canine leishmaniosis (CanL) is a chronic and potentially fatal disease. The prognosis of CanL depends on the severity of the clinical signs and clinicopathological abnormalities presented by the dog at the time of diagnosis. This study aims to estimate the survival time of dogs with CanL, determining the prognostic value of different clinical and clinicopathological parameters. Medical records of 99 dogs diagnosed with CanL in five veterinary centers of the Alentejo region (Portugal) were examined retrospectively. The majority of dogs presented hyperproteinemia, moderate normocytic normochromic anemia, normal blood urea and creatinine levels and were classified as stage 1 according to the International Interest Society (IRIS) guidelines at the time of diagnosis. The severity of anemia, presence of concomitant infectious diseases at the time of diagnosis and the anti-Leishmania therapy were correlated with the survival time. The influence of renal dysfunction was evaluated by Receiver Operating Characteristic (ROC) curve and survival analysis. Survival analysis demonstrated that patients classified as IRIS 1 at the time of diagnosis survived more than four years, in contrast with dogs classified as IRIS 2 that survived around two and half years and dogs classified as IRIS 3–4 that survived around one month. IRIS stage deteriorated during the course of CanL in one third of the dogs and was the principal cause of death or euthanasia in a high proportion of animals. In some cases, dogs did not receive anti-Leishmania treatment or abandoned the veterinary follow-ups, which may have considerable repercussions for animal wellbeing and public health. This study reinforces the value of blood urea and creatinine levels as prognostic factors in CanL.info:eu-repo/semantics/publishedVersio

Formação humana na formação de professores do campo no Ceará

This work presents results obtained in a funded research that analyzed the in-service formative processes of teachers from secondary schools in rural areas of agrarian reform settlement in Ceará. It was chosen here to focus, among the identified formative processes, those referring to a perspective of human formation, including this category from Lukács (2013). In this way, the work elucidates human formation as a category of analysis, having as an investigative stance the historical-dialectical materialism. Finally, the results obtained from interviews with fifteen teachers from four rural schools in Ceará are presented, pointing out contributions to the training of rural teachers. The results found point to the importance of human formation in the adhesion of teachers to the pedagogical project of rural schools. It was concluded that there is a need for permanent and long-term training of field teachers, aiming to implement the proposals of a different school.Este trabalho apresenta resultados obtidos numa pesquisa financiada que analisou os processos formativos em serviço de professores das escolas do campo de ensino médio em áreas de assentamento da reforma agrária no Ceará. Optou-se aqui por enfocar, dentre os processos formativos identificados, àqueles referentes a uma perspectiva de formação humana, compreendendo essa categoria a partir de Lukács (2013). Dessa forma, o trabalho elucida a formação humana enquanto categoria de análise, tendo como postura investigativa o materialismo histórico-dialético. Por fim, apresenta-se os resultados obtidos a partir das entrevistas realizadas com quinze professores de quatro escolas do campo do Ceará, apontando contribuições a formação de professores do campo. Os resultados encontrados apontam para a importância da formação humana na adesão dos professores ao projeto pedagógico das escolas do campo. Concluiu-se que há necessidade de formação permanente e a longo prazo dos professores do campo, almejando efetivar as propostas de uma escola diferente