A potential vector of Schistosoma mansoni in Uruguay Um vetor potencial do Schistosoma mansoni no Uruguai

Susceptibily experiments were carried out with a Biomphalaria straminea-like planorbid snail (Biomphalaria aff. straminea, species inquirenda) from Espinillar, near Salto (Uruguay), in the area of the Salto Grande reservoir, exposed individually to 5 miracidia of Schistosoma mansoni (SJ2 and BH2 strains). Of 130 snails exposed to the SJ2 strain, originally infective to Biomphalaria tenagophila, 30 became infected (23%). The prepatent (precercaria) period ranged from 35 to 65 days. The cercarial output was irregular, following no definite pattern, varying from 138 to 76,075 per snail (daily average 4.3 to 447.5 and ending up with death. Three specimens that died, without having shed cercarie, on days 69 (2) and 80 after exposure to miracidia, had developing secondary sporocysts in their tissues, justifying the prospect of a longer precercarial period in these cases. In a control group of 120 B. teangophila, exposed to the SJ2 strain, 40 became infected, showing an infection rate (33.3%) not significantly different from that of the Espinillar snail (X [raised to the power of] 2 = 3.26). No cercarie were produced by any of the Espinilar snails exposed to miracidia of the BH2 strain, originally infective to Biomphalaria glabrata. Four specimens showed each a primary sporocyst in one tentacle, which disappeared between 15 and 25 days post-exposure, and two others died with immature, very slender sporocysts in their tissues on days 36 and 54. In a control group of 100 B. glabrata exposed to BH2 miracidia, 94 shed cercariae (94%) and 6 remained negative. Calculation of Frandsen's (1979a, b) TCP/100 index shows that "Espinillar Biomphalaria-SJ2 S. mansoni" is a vector-parasite "compatible" combination. Seeing that tenagophila-borne schistosomiasis is prevalent in Rio de Janeiro and São Paulo states and has recently spread sothwards to Santa Catarina state, and the range of B. tenagophila overlaps taht of the Espinillar Biomphalaria, the possibility of schistosomiais establishing itself in Uruguay, although not imminent, is not to be disregarded.<br>Foram feitas provas de suscetibilidade com um molusco planorbídeo semelhante à Biomphalaria straminea (species inquirenda) de Espinillar, localidade próxima a Salto (Uruguay), na área da represa de Salto Grande, cada exemplar sendo exposto individualmente a 5 miracídios de Schistosom mansoni (cepas SJ2 e BH2). De 130 exemplares expostos à cepa SJ2, originalmente infectante para B. tenagophila, 30 se infectaram (23%). O período pré-patente (pré-cercariano) variou de 35 a 65 dias. A emissão de cercárias foi irregular, não seguindo padrão definido, variando de 138 a 76.075 por exemplar (média diária de 4,3 a 447,5) e teminando com a morte. Três exemplares que morreram, sem ter eliminado cercárias, no 69º (2) e no 80º dia após exposição aos miracídios, tinham esporocistos secundários em desenvolvimento nos tecidos, justificando a expectativa de um período pré-patente mais longo nestes casos. Em um grupo-controle de 120 B. tenagophila, exposta à cepa SJ2, 40 se infectaram, não diferindo significativamente seu índice de infecção (33.3%) daquele do planorbídeo de Espinillar (X [ao quadrado]=3.26). De 100 exemplares de Espinillar expostos a miracídios da cepa BH2, originalmente infectante para B. glabrata, nenhum produziu cercárias. Um esporocisto primário formou-se em um tentáculo em 4 exemplares, desaparecendo entre 15 e 25 dias após a exposição. Dois outros exemplares morreram com esporocistos imaturos e muito delgados nos tecidos (4 em um caso e 3 no outro), no 36º e 54º dias. Em um grupo-controle de 100 B. glabrata exposto à cepa BH2, 94 emitiram cercárias (94%) e 6 permaneceram negativos. De acordo com o índice TCP/100 de Frandsen (1979a,b), a combinação Biomphalaria de Espinillar-S. mansoni SJ2 constitui uma relação vetor-parasito "compatível". Tendo em vista que a xistosomose transmitida pela B. tenagophila é prevalente nos estados do Rio de Janeiro e São Paulo e recentemente propagou-se para o sul até o estado de Santa Catarina, e a distribuição geográfica da B. tenagophila soprepõe-se à da Biomphalaria de Espinilar, a possibilidade do estabelecimento da xistosomose no Uruguai, ainda que não iminente, não deve ser desconsiderada

Oxidative damage in human periodontal ligament fibroblast (hPLF) after methylmercury exposure

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. Lygia S. Nogueira was supported by Programa Nacional de Pós-Graduação (PNPD/CAPES).Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Toxicologia. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil / Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil.Human exposure to mercury (Hg) is primary associated with its organic form, methylmercury (MeHg), through the ingestion of contaminated seafood. However, Hg contamination is also positively correlated with the number of dental restorations, total surface of amalgam, and organic mercury concentration in the saliva. Among the cells existing in the oral cavity, human periodontal ligament fibroblast (hPLF) cells are important cells responsible for the production of matrix and extracellular collagen, besides sustentation, renewal, repair, and tissue regeneration. In this way, the present study is aimed at investigating the potential oxidative effects caused by MeHg on hPLF. Firstly, we analyzed the cytotoxic effects of MeHg (general metabolism status, cell viability, and mercury accumulation) followed by the parameters related to oxidative stress (total antioxidant capacity, GSH levels, and DNA damage). Our results demonstrated that MeHg toxicity increased in accordance with the rise of MeHg concentration in the exposure solutions (1-7 μM) causing 100% of cell death at 7 μM MeHg exposure. The general metabolism status was firstly affected by 2 μM MeHg exposure (43:8±1:7%), while a significant decrease of cell viability has arisen significantly only at 3 μM MeHg exposure (68:7±1:4%). The ratio among these two analyses (named fold change) demonstrated viable hPLF with compromised cellular machinery along with the range of MeHg exposure. Subsequently, two distinct MeHg concentrations (0.3 and 3 μM) were chosen based on LC50 value (4.2 μM). hPLF exposed to these two MeHg concentrations showed an intracellular Hg accumulation as a linear-type saturation curve indicating that metal accumulated diffusively in the cells, typical for metal organic forms such as methyl. The levels of total GSH decreased 50% at exposure to 3 μM MeHg when compared to control. Finally, no alteration in the DNA integrity was observed at 0.3 μM MeHg exposure, but 3 μM MeHg caused significant damage. In conclusion, it was observed that MeHg exposure affected the general metabolism status of hPLF with no necessary decrease on the cell death. Additionally, although the oxidative imbalance in the hPLF was confirmed only at 3 μM MeHg through the increase of total GSH level and DNA damage, the lower concentration of MeHg used (0.3 μM) requires attention since the intracellular mercury accumulation may be toxic at chronic exposures

Gene expression profile in immortalized human periodontal ligament fibroblasts through hTERT ectopic expression: transcriptome and bioinformatic analysis

This study was partially supported by a grant provided by CNPq (Brazilian National Council for Scientific and Technological Development, 435093/2018-5) and CAPES/PROCAD - Higher Education Improvement Coordination (23038.005350/2018-78; Finance Code 001). Pró-Reitoria dePesquisa e Pós-graduação from the Federal University of Pará (PROPESP-UFPA).Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. School of Dentistry. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.University of São Paulo. Medical School . Regional Blood Center at University Hospital. Ribeirão Preto, SP, Brazil.Federal University of Pará. School of Dentistry. Belém, PA, Brazil.Federal University of Pará. School of Dentistry. Belém, PA, Brazil.University of São Paulo. School of Dentistry of Bauru. Bauru, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Human periodontal ligament fibroblast (hPLF) cells play an important role in maintaining oral cavity homeostasis with special function in tissue regeneration and maintenance of dental alveoli. Although their primary cell cultures are considered a good experimental model with no genetic changes, the finite life span may limit some experimental designs. The immortalization process increases cell life span but may cause genetic changes and chromosomal instability, resulting in direct effects on physiological cell responses. In this way, we aimed to investigate the global gene expression of hPLFs after the immortalization process by the ectopic expression of the catalytic subunit of the enzyme telomerase reverse transcriptase (hTERT) through transcriptome analysis. The embryonic origin of the primary culture of hPLF cells and immortalized hPLF-hTERT was also tested by vimentin staining, hTERT synthesis evaluated by indirect immunocytochemistry, analysis of cell proliferation, and morphology. The results indicated that hPLFs and hPLF-hTERT were positive for vimentin. On the 20th cell passage, hPLFs were in senescence, while hPLF-hTERT maintained their proliferation and morphology characteristics. At the same passage, hPLF-hTERT presented a significant increase in hTERT synthesis, but transcriptome did not reveal overexpression of the hTERT gene. Fifty-eight genes had their expression altered (11 upregulated and 47 downregulated) with the absence of changes in the key genes related to these cell types and in the main cancer-associated genes. In addition, the increase in hTERT protein expression without the overexpression of its gene indicates posttranscriptional level regulation. Successful immortalization of hPLFs through the ectopic expression of hTERT encourages further studies to design experimental protocols to investigate clinical questions from a translational perspective