Social modulation of sex steroid concentrations in the urine of male cichlid fish Oreochromis mossambicus

The relationship between urinary concentrations (free + sulfates + glucuronides) of the steroids testosterone (T), 11-ketotestosterone (11KT), 17α, 20ß-dihydroxy-4-preg- nen-3-one (17,20ß-P) and 17a,20a-dihydroxy-4-preg- nen-3-one (17,20α-P), and the social behavior of males of the cichlid fish Oreochromis mossambicus was inves- tigated. After 8 days of isolation none of the steroids were good predictors of social dominance developed after subsequent formation of all-male groups. One day after group formation dominance indexes were good predictors of the urine concentrations of all sex steroids. Dominance indexes and androgen concentrations mea- sured after all-male group formation were positively cor- related with territoriality, courtship rate, and nest size. Similar relationships were found for progestins with the exception that they were not correlated with courtship rate. All-male group formation was also accompanied by an increase in urinary sex steroid concentrations in fish that became territorial and a decrease in non-territorial fish with the exception of T, which increased in both groups. Addition of ovulating females caused steroid concentrations to return to levels near isolation, except for 17,20α-P in territorials, which underwent a large in- crease. Thus, social interactions may have an important modulatory effect on sex steroid concentrations in O. mossambicus

Bioactive potential and chromatographic characterization of body mucus from Portugal coastal fish halobatrachus didactylus

The body mucus in fish provides a stable physical or chemical barrier against invading pathogens. In mucus, antimicrobial peptides are secreted as a response to immunestimulation. Studies have shown antimicrobial activity against multidrug­resistant pathogens and low toxicity to eukaryotic cells. Previously, body mucus from five captive Halobatrachus didactylus individuals was collected. We aim to explore the mucus studying molecules with bioactive potential. Size exclusion high­performance liquid chromatography (SE­HPLC) analyses were performed on the five body mucus samples showing a similar molecular size distribution with a maximum peak of ca. 800 Da. These five mucus samples were pooled to assess the following bioactivities: antioxidant (ABTS and ORAC), antimicrobial (minimal inhibitory concentration), andcytotoxicity (Caco­2 and HaCaT human cell lines). The protein content in the mucus, determined by the bicinchoninic acid methodology, was 16836 ± 1020 µg BSA/mL. The antioxidant activity resulted in 268 ± 11 µmol TE/g mucus protein for ABTS and 306 ± 11 µmol TE/g mucus protein for ORAC. The antibacterial activity was assessed against five pathogenic bacteria: Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, within minimal inhibitory concentrations of 421 to 105 µg mucus protein/mL. Moreover, the mucus showed non­cytotoxic for Caco­2 cells in concentrations between 196 to 25 µg mucus protein/mL, while it showed cytotoxicity for HaCaT cells. In the future, liquid chromatography­tandem mass spectrometry (LC­MS/MS) analysis will be performed to determine the molecules behind these bioactivities, namely antimicrobial peptides.info:eu-repo/semantics/publishedVersio

First bioactive characterization of the skin mucus from Portugal coastal fish Halobatrachus didactylus

info:eu-repo/semantics/publishedVersio

Peptide fraction identification by SE-HPLC and LC-MS/MS analysis of the body mucus from Portugal coastal fish Halobatrachus didactylus

The mucus covers the fish's body, working as a protective barrier. Besides physical protection, mucus provides molecules that protect the fish from pathogens damaging. 1,2These include antimicrobial peptides secreted in the mucus, which play an essential role in defense against microbial pathogens since these belong to the innate immune system2,3. In this study, two adult Halobatrachus didactylus individuals were captured from the wild in Sesimbra. Then, mucus collection was performed by scraping the dorsal-lateral body of the fish with a sponge. Our objective was the identification of new peptides with bioactive potential in mucus samples by chromatography analysis. Size exclusion high-performance liquid chromatography (SE-HPLC) analysis performed on mucus samples from the two individuals revealed a similar profile with an intense highlight peak which resulted in a distribution of about 775 Dalton. With interest in that peak, the two mucus samples were pooled for fractionation by SEC. The resulting fraction was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the most probable peptide sequences. Identification from databases did not provide reliable results, indicating a lack of information on the matrix analyzed. We resorted to de novo sequencing with good results using PEAKS Studio software. Five identified peptides were selected according to their bioactivities predicted in silico. Furthermore, the five identified peptides were synthesized, and the molecular size was validated by SE-HPLC analysis. Overall, this chromatographic approach enabled the identification of promising peptides, which bioactivities will be evaluated in vitro in future work.info:eu-repo/semantics/publishedVersio

PALM and STORM: Into large fields and high-throughput microscopy with sCMOS detectors

Single Molecule Localization Microscopy (SMLM) techniques such as Photo-Activation Localization Microscopy (PALM) and Stochastic Optical Reconstruction Microscopy (STORM) enable fluorescence microscopy super-resolution: the overcoming of the resolution barrier imposed by the diffraction of light. These techniques are based on acquiring hundreds or thousands of images of single molecules, locating them and reconstructing a higher-resolution image from the high-precision localizations. These methods generally imply a considerable trade-off between imaging speed and resolution, limiting their applicability to high-throughput workflows. Recent advancements in scientific Complementary Metal-Oxide Semiconductor (sCMOS) camera sensors and localization algorithms reduce the temporal requirements for SMLM, pushing it toward high-throughput microscopy. Here we outline the decisions researchers face when considering how to adapt hardware on a new system for sCMOS sensors with high-throughput in mind

Análise sensorial da aparência de cinco tipos de palmitos: com e sem rotulagem.

O palmito é considerado uma iguaria tipicamente brasileira e de grande aceitação no mercado, tanto interno quanto externo, sendo que, nos EUA e na Europa, esse compete com produtos como alcachofra e aspargo. É classificado como uma hortaliça não convencional e pode ser extraído de várias espé cies de palmeiras, sendo que a escolha destas depende de fatores como disponibilidade, palatabilidade, cor, formato e rendimento, além da facilidade de extração. No Brasil, antes da década de 60, a extração era feita de forma predatória e concentrava-se no palmito do tipo Juçara, nativo da Mata Atlântica. Como este apresenta um ciclo longo e sua palmeira não perfilha (necessita de replantio) sua presença natural foi quase exterminada. Devido ao aumento da fiscalização por órgãos oficiais impedindo a devastação predatória, ao custo do reflorestamento e ao alto preço do produto no mercado externo, houve um incentivo ao plantio comercial e produção racional de palmito industrializado. Para isso, houve uma busca por gêneros da família Palmae que fornecessem palmito de boa qualidade em curto prazo. As espécies de maior importância sócio-econômica e ambiental são: Juçara, Açaí, Pupunha, Palmeira Real e Babaçu. Portanto, o objetivo desse trabalho foi avaliar a preferência dos palmitos quanto a aparência do produto em salmoura sem e com a rotulagem. Inicialmente foi aplicado um questionário para caracterizar o perfil do consumidor e em seguida foi realizado os testes de ordenação da preferência (1= desgostei e 5= gostei) quanto à aparência dos palmitos. Para ambos os testes foram utilizados 50 provadores, que ordenaram as amostras da esquerda para a direita conforme a cor e preferência. A interpretação dos dados obtidos nos testes de ordenação de preferência visual foi de acordo com a ABNT (1994). Para os resultados (5 amostras e 50 respostas) constatou-se que, para que haja diferença significativa entre as amostras ao nível de 5% de significância, a diferença entre o somatório de cada par de amostras deve ser igual ou maior que 44. Com o resultado da caracterização do grupo dos provadores, foi possível notar que a forma de consumo ficou em sua maioria no consumo do tipo salada e em recheio de salgados. Já os itens observados que decidiriam a compra de um determinado palmito foram: data de validade, preço e o tipo de palmito seriam os mais importantes. Quanto à preferência dos palmitos sem rotulo, os resultados mostraram a seguinte ordem nos valores dos somatórios: Babaçu (119) < Pupunha (132) < Juçara (154) < Palmeira Real (170) < Açaí (175). Verificou-se, portanto, que houve diferença significativa (p?0,05) entre o Babaçu e os palmitos Palmeira Real e Açaí, porém o não ocorreu diferença na preferência entre as demais. Quanto a preferência dos palmitos com rotulagem em relação a embalagem, verificou-se que as somatórias foram: Babaçu (117) < Palmeira Real (150) < Juçara (153) < Açaí (162) < Pupunha (168) com diferença significativa (p?0,05) entre o Babaçu e os palmitos Açaí e Pupunha. Desta maneira conclui-se que a rotulagem afetou significativamente a escolha do produto, com exceção do Babaçu que obteve resultados inferiores nos dois testes