Papers by JOSÉ CLECILDO BARRETO BEZERRA
The snail Biomphalaria glabrata acts as an intermediate host to Schistosoma mansoni, an endemic p... more The snail Biomphalaria glabrata acts as an intermediate host to Schistosoma mansoni, an endemic parasite in several countries. B. glabrata hemocytes are related to its defense against infection by trematodes, including S. mansoni. In the present paper, the activity of molluscicidal substances such as the tannic acid extracts of Stryphnodendron polyphyllum, a plant from the Brazilian Savannah, on the morphology and number of B. glabrata hemocytes was evaluated. The bark and leaf extracts of S. polyphyllum were diluted in dechlorinated water and groups of snails were exposed to 25 and 50 mg.L -1 concentrations of the extracts, as well as, to tannic acid during 24h. Subsequently, hemolymph was removed from the pericardic region. Hemocyte subpopulations were detected and classified as small (5.0 -6.9 µm), medium (7.0 -8.9μm), large (9.0 -12.0μm) and giant (over 12μm), the latter being a novel classification. The extracts stimulated an increase in the number of hemocyte cells in the hemolymph. This is understood as a defense mechanism against toxic substances such as tannic acid, present in high levels in both tested extracts. Hemocytes showed vacuoles in the cytoplasm due to the presence of such substances, which are signs of cellular death due to apoptosis. We conclude that the extracts are highly effective against B. glabrata, recommending further biological impact studies aiming its use as a natural molluscicide.
BioMed Research International, 2015
Leishmaniasis is a complex disease that affects mammals and is caused by approximately 20 distinc... more Leishmaniasis is a complex disease that affects mammals and is caused by approximately 20 distinct protozoa from the genus Leishmania. Leishmaniasis is an endemic disease that exerts a large socioeconomic impact on poor and developing countries. The current treatment for leishmaniasis is complex, expensive, and poorly efficacious. Thus, there is an urgent need to develop more selective, less expensive new drugs. The energy metabolism pathways of Leishmania include several interesting targets for specific inhibitors. In the present study, we sought to establish which energy metabolism enzymes in Leishmania could be targets for inhibitors that have already been approved for the treatment of other diseases. We were able to identify 94 genes and 93 Leishmania energy metabolism targets. Using each gene's designation as a search criterion in the TriTrypDB database, we located the predicted peptide sequences, which in turn were used to interrogate the DrugBank, Therapeutic Target Database (TTD), and PubChem databases. We identified 44 putative targets of which 11 are predicted to be amenable to inhibition by drugs which have already been approved for use in humans for 11 of these targets. We propose that these drugs should be experimentally tested and potentially used in the treatment of leishmaniasis.
Saúde Coletiva: Uma construção teórico-prática permanente 5
Revista de Ciências Farmacêuticas Básica e Aplicada, 2008
The leishmaniasis is a parasitic disease caused by protozoons of the genus Leishmania. It is an e... more The leishmaniasis is a parasitic disease caused by protozoons of the genus Leishmania. It is an endemic illness across 80 countries, some in the European continent but most of them in underdeveloped or developing regions. This article reviews traditional and current treatments whose leishmanicidal activity may lead to the rational development of new drugs. The main focus is the application of natural products to the treatment of leishmaniasis (e.g.: quinolines, chalcones and crude extracts)
Revista de Patologia Tropical / Journal of Tropical Pathology, 2018
Schistosomiasis is a neglected tropical disease caused by parasites of the genus Schistosoma. In ... more Schistosomiasis is a neglected tropical disease caused by parasites of the genus Schistosoma. In Brazil only Schistosoma mansoni causes this disease. The World Health Organization estimated in 2012 approximately 249 million people at risk of acquiring this disease around the world. The main strategy to control this disease is praziquantel treatment of individuals living in endemic areas. The drug praziquantel is used on a large scale in the treatment of schistosomiasis and currently there are reported cases of resistance, indicating the need to discover new drugs. In silico drug repositioning is a time and cost reducing strategy in the search for anti-Schistosoma agents. This work used bioinformatic tools to identify potential schistosomicidal drugs. A list was compiled of S. mansoni potential targets that are part of essential processes in the database TDR and the targets that are part of the tegument were obtained in the scientific literature. The file with S. mansoni targets contained 1,376 targets, and of these only 61 targets associated with 399 drugs had homology with drug targets. After removal of duplicate drugs, drugs found in previous studies and after the analysis of the conservation of the binding site, only 28 S. mansoni targets associated with 102 drugs had 60% or more of the active site conserved. Some of the drugs had activity and are interesting to validate this study such as: artemether, lumefantrine, meloxicam. Among the drugs found 18 drugs were selected to be tested in prospective experimental assays according to the following criteria: low toxicity in vivo, off-patent status, and logP <5.0.
Revista de Biologia Neotropical / Journal of Neotropical Biology, Nov 6, 2019
Brazilian Journal of Biology, 2016
Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabr... more Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabrata (Say, 1818), intermediate host of Schistosoma mansoni Sambon, 1907 in Brazil, and represents a limiting factor to its distribution and adaptation to the environment. This study investigated the effect of different concentrations of exogenous CaCO3 on the energetic metabolism of B. glabrata for better understanding the physiological interference of chemical elements dissolved in the environment with the physiology of this species. Sixty-day-old snails were distributed into six groups, five exposed to different concentrations of CaCO3 (20, 40, 60, 80 and 100 mg/L) and a control group. The exposure to CaCO3 was assessed over time, with analysis of 15 snails of each group in the following intervals: 1, 14, 21 or 30 days for hemolymph extraction. Concentrations of calcium and glucose in the hemolymph were determined by commercial kits, and organic acids were extracted using an ion exchang...
Revista de Patologia Tropical, 2014
Revista de Patologia Tropical, 2008
Experimental Parasitology, 2011
Leishmania spp are protozoans capable of carbohydrates degradation and as energy source they can ... more Leishmania spp are protozoans capable of carbohydrates degradation and as energy source they can use glucose, aminoacids or lipids from the environment. The products of the metabolic pathways such as organic acids may be used as an index of their energetic metabolic profile. Therefore, in this study a metabolic profile comparison was made between promastigotes from one reference strain (MHOM/ BR/1975/M2903) and two different isolates of Leishmania (Viannia) braziliensis (MHOM/BR/2003/IMG3 and MHOM/BR/2005/RPL5). The parasites culture was performed in complete Grace's culture media seeded in 24-well plates at 26 °C. During the growth curve performance samples were collected from the logarithmic and stationary phases of culture and therefore analyzed by high performance liquid chromatography (HPLC) and spectrophotometry assays to determine the concentrations of glucose, lactate, citrate, a-ketoglutarate, succinate, fumarate, malate, oxaloacetate and b-hydroxybutirate which are indicative of the energetic pathways. It was possible to detect an increase in the glucose from the stationary phase from the M2903 strain when compared to the logarithmic phase while in the IMG3 and RPL5 isolates there was a decrease (p < 0.05). The spectrophotometric and chromatographic results indicated that the logarithmic phase which presents higher energy consumption due to the intense replication rate have the energetic pathways intensified. It was also possible to note some metabolic differences between the analyzed parasites which may indicate possible adaptations of the parasite when facing different environmental and physiological conditions during its life cycle and that these differences may help in the understanding of the diversity of the host-parasite relationship from Leishmania parasites.
Anais da Academia Brasileira de Ciências, 2020
Plant-derived molluscicides have been indicated as biodegradable and lowcost strategies for contr... more Plant-derived molluscicides have been indicated as biodegradable and lowcost strategies for control of Biomphalaria spp., intermediate host for the Schistosoma. This study evaluated whether the crude ethanolic extract of the Persea americana stem bark has molluscicidal activity against embryos, newly-hatched and adults of Biomphalaria glabrata. The extract was obtained, characterized and its toxicity analyzed by snail embryotoxicity test (144 h) and acute toxicity test with newly-hatching and adult snails (96 h). Results showed the presence of fl avonoids, anthraquinone heterosides, coumarins and tannins in the crude ethanolic extract, which showed molluscicidal activity against all life cycle stages of B. glabrata. The LC 50 for embryos, newly-hatched and adults were 27.06, 30.60 and 55.55 ppm, respectively. Embryos exposed to the extract at 50 ppm showed hatching inhibition and at 6.2 and 25 ppm had the highest rates of morphological alterations, such as shell malformations and coagulation of the perivitelline substance. Adult snails exposed to the extract at 75 ppm showed a peak of behavioral changes, such as lethargy and shell reclusion, in addition to answers like hemolymph release in most concentrations. Further studies are required, prioritizing toxicity testing on non-target organisms and further elucidation of the active molecules.
Latin American Journal of Business Management, 2014
A vigilância sanitaria e importante componente do Sistema Unico de Saude no processo de protecao,... more A vigilância sanitaria e importante componente do Sistema Unico de Saude no processo de protecao, promocao e defesa da saude. Este estudo objetivou analisar a estruturacao da vigilância sanitaria de municipios goianos (VISAM), na percepcao dos seus trabalhadores, e relacionar os processos de trabalho, as condicoes e organizacao do trabalho, as relacoes socioprofissionais, o estilo de lideranca exercido pelos gestores e a gestao de pessoas e processos. Participaram 335 trabalhadores da VISAM de 53 municipios goianos, respondendo os diferentes instrumentos adotados no estudo. Utilizou-se o programa SPSS (Statistical Package for the Social Sciences) for Windows, versao 18, para tratamento estatistico. Evidenciou-se que a gestao de pessoas e processos ocorre de maneira mais eficaz para o desenvolvimento das atividades do servico, sem que haja preocupacao com os aspectos dos recursos humanos. A maioria dos respondentes avaliou as condicoes e organizacao do trabalho como graves ou critica...
New Journal of Chemistry, 2020
Schistosomiasis control in endemic areas depends on several factors, including mass drug delivery... more Schistosomiasis control in endemic areas depends on several factors, including mass drug delivery programs and interrupting the transmission of disease by controlling the intermediate host snails in the freshwater ecosystem using molluscicides.
Acta Tropica, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Chemosphere, Jan 8, 2018
Schistosomiasis is a disease that affects tropical and subtropical areas and is considered the se... more Schistosomiasis is a disease that affects tropical and subtropical areas and is considered the second most prevalent parasitic disease in the world. One of the ways of combating this disease is the use of molluscicidal agents to eliminate or reduce the population of intermediate host snails. Polyhexamethylene biguanide hydrochloride (PHMB) is a chemical biocide commonly used as a disinfectant and antiseptic in the food industry and very successfully for the disinfection of swimming pools. The US Environmental Protection Agency (USEPA) indicated the PHMB as low environmental risk. The present study aimed to evaluate the molluscicidal activity of the PHMB in freshwater snail (Biomphalaria glabrata), intermediate host of Schistosoma mansoni. The PHMB showed high toxicity against all stages of the snail B. glabrata: embryos, new-borns and adults. The LC estimated was 0.98 mg L; 1.43 mg L and 1.49 mg L, respectively, after exposure of 144 h for embryos and 96 h for new-borns and adults. ...
Revista de Administração em Saúde, 2018
Objetivo: Identificar fatores que contribuem para a subnotificação de doenças e agravos de notifi... more Objetivo: Identificar fatores que contribuem para a subnotificação de doenças e agravos de notificação compulsória no Sistema Nacional de Agravos de Notificação (Sinan), na percepção dos profissionais de saúde. Métodos: Estudo conduzido com base na Técnica dos Incidentes Críticos para a coleta dos dados e na análise de conteúdo, em uma amostra estratificada de trabalhadores e gestores das unidades de vigilância em saúde responsáveis pelas notificações de doenças e agravos de notificação compulsória. Resultados: Os casos relatados associaram-se a 33 doenças e agravos de notificação compulsória e os principais comportamentos resultantes foram a não notificação ou a notificação tardia no Sinan. A conduta do médico ou enfermeiro, as dificuldades no processo de notificação e os problemas relacionados ao paciente e/ou familiares foram os principais fatores associados à subnotificação. Conclusão: A subnotificação é uma realidade vivenciada nas unidades de atendimento ao paciente e esconde ...
Revista de Patologia Tropical, 1996
Um caso de paraplegia em uma paciente de 36 anos é associado a infecção não autóctone de Schistos... more Um caso de paraplegia em uma paciente de 36 anos é associado a infecção não autóctone de Schistosoma mansoni, A possibilidade da presença de fatores que possibilitarão o estabelecimento desta parasitose no Estado de Goiás é discutida. Goiás; Migração do ovo; Paraplegia; Schistosoma. A doença tropical esquistossomose, causada pelo parasito Schistosoma mansoni, ocupa lugar de destaque entre as parasitoses humanas. Estima-se que cerca de 8 milhões de brasileiros estejam infectados, com ocorrência em várias unidades da federação e prevalência variada. A área de risco estimada para infecção corresponde
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Papers by JOSÉ CLECILDO BARRETO BEZERRA