ABUNDÂNCIA E DENSIDADE DAS LARVAS DE PEIXES E SUA RELAÇÃO COM NÍVEL DAS ÁGUAS NA CONFLUÊNCIA DOS RIOS SOLIMÕES E NEGRO E NO LAGO CATALÃO, AMAZONAS-BRASIL

Fish spawning in river and lake environment was evaluated through the abundance of ichthyoplankton at intervals of 2 m in height according to the river cycle. For collection, a cone-cylindrical type net was used with a coupled flow meter to record the volume of water and to calculate the density of larvae/10 m3. It was observed that the migratory Characiformes assemblage performs spawning scheduling in the Solimões River with a higher density of larvae/10 m3 between the coasts of 20 and 26 m. Branquinhas (Curimatídeos) and jaraquis (Semaprochilodus spp.) carry out a single spawning between the heights of 21 and 23 m. Sardines (Triportheus auritus and T. elongatus) and pacu (Mylossoma spp.) spawn in a piecemeal fashion in the 18 to 20 m depths and 21 to 19 m in the ebb. The Aracus (Anostomidae and Hemiodontids) begin spawning before the whitish ones at the height of 19 m. At Lake Catalão, we observed the spawning of Clupeiformes with the presence of eggs at a height of 19 m and of Triportheus albus (Characidae) and Plagioscion squamosissimus (Scianidae, Perciformes) in the heights of 19 to 21 m. In the Solimões River, intense spawning of Clupeiformes occurs (ANOVA One-way F = 3.79; df = 35 p = 0. 0001966) between the 18 and 16 m depths. It is concluded that, through quotas, it is possible to estimate with more precision the location and time of fish spawning in the Amazon, generating information that can serve as a basis for the creation of strategies and support wider closed programs for the conservation and species preservation.Keywords: Ichthyoplankton; quota of the river; spawning; migratory fish; fishing resources.Avaliou-se a desova de peixes em ambiente fluvial e lacustre através da abundância do ictioplâncton em intervalos de cota de 2 em 2 m de acordo com o ciclo dos rios. Para coleta, utilizou-se uma rede tipo cônico-cilíndrica com um fluxímetro acoplado para registrar o volume de água e assim calcular a densidade de larvas/10 m3. Observou-se que a assembleia de Characiformes migradores realiza um escalonamento de desova no rio Solimões com maior densidade de larvas/10 m3 entre as cotas de 20 a 26 m. Branquinhas (Curimatídeos) e jaraquis (Semaprochilodus spp.) realizam uma única desova entre as cotas de 21 a 23 m. Sardinhas (Triportheus auritus e T. elongatus) e pacu (Mylossoma spp.) desovam de forma parcelada nas cotas de 18 a 20 m e 21 a 19 m na vazante. Os Aracús (Anostomídeos e Hemiodontideos) iniciam a desova antes das branquinhas na cota de 19 m. No lago Catalão, constatamos a desova de Clupeiformes com a presença de ovos na cota de 19 m e de Triportheus albus (Characidae) e Plagioscion squamosissimus (Scianidae, Perciformes) nas cotas de 19 a 21 m. No rio Solimões, ocorre uma intensa desova de Clupeiformes(ANOVA One-way F=3,79; df=35 p=0,0001966) entre as cotas de 18 e 16 m. Conclui-se que, através das cotas, é possível estimar com mais precisão o local e a época da desova dos peixes na Amazônia, gerando informações que podem servir de base para criação de estratégias e subsidiar programas de defeso mais abrangentes visando a conservação e preservação das espécies.Palavras-chave: Ictioplâncton, cota do rio, desova, peixes migradores, recursos pesqueiros

Vaccination with a CD4+ and CD8+ T-cell epitopes-based recombinant chimeric protein derived from Leishmania infantum proteins confers protective immunity against visceral leishmaniasis.

Vaccination seems to be the best approach to control visceral leishmaniasis (VL). Resistance against infection is based on the development of a Th1 immune response characterized by the production of interferons-? (IFN-?), interleukin-12 (IL-12), granulocyte-macrophage-colony-stimulating factor (GM-CSF), and tumor necrosis factor-? (TNF-?), among others. A number of antigens have been tested as potential targets against the disease; few of them are able to stimulate human immune cells. In the present study, 1 prediction of MHC class I and II molecules-specific epitopes in the amino acid sequences of 3 Leishmania proteins: 1 hypothetical, prohibitin, and small glutamine-rich tetratricopeptide repeat-containing proteins, was performed using bioinformatics tools, and a T-cell epitopes-based recombinant chimeric protein was constructed, synthetized and purified to be evaluated in invitro and in vivo experiments. The purified protein was tested regarding its immunogenicity in peripheral blood mononuclear cells (PBMCs) from healthy subjects and VL patients, as well as to its immunogenicity and protective efficacy in a murine model against Leishmania infantum infection. Results showed a Th1 response based on high IFN-? and low IL-10 levels derived from in chimera-stimulated PBMCs in both healthy subjects and VL patients. In addition, chimera and/or saponin-immunized mice presented significantly lower parasite burden in distinct evaluated organs, when compared to the controls, besides higher levels of IFN-?, IL-2, IL-12, and GM-CSF, and an IgG2a isotype-based humoral response. In addition, the CD4+ and CD8+ T-cell subtypes contributed to IFN-? production in the protected animals. The results showed the immunogenicity in human cells and the protective efficacy against L. infantum in a murine model, and well indicate that this recombinant chimera can be considered as a promising strategy to be used against human disease

Photobiomodulation reduces the cytokine storm syndrome associated with Covid-19 in the zebrafish model

Although the exact mechanism of the pathogenesis of COVID-19 is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red PBM as an attractive therapy to downregulate the cytokine storm caused by COVID-19 from a zebrafish model. RT-PCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that rSpike was responsible for generating systemic inflammatory processes with significantly increased pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a, coa1) mRNA markers, with a pattern like those observed in COVID-19 cases in humans. On the other hand, PBM treatment decreased the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most impacted metabolic pathways between PBM and the rSpike-treated groups were related to steroid metabolism, immune system, and lipids metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19, and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials.publishedVersio