Antigenic epitope targets of rhesus macaques self-curing from Schistosoma mansoni infection

The self-cure of rhesus macaques from a schistosome infection and their subsequent strong immunity to a cercarial challenge should provide novel insights into the way these parasites can be eliminated by immunological attack. High-density arrays comprising overlapping 15-mer peptides from target proteins printed on glass slides can be used to screen sera from host species to determine antibody reactivity at the single epitope level. Careful selection of proteins, based on compositional studies, is crucial to encompass only those exposed on or secreted from the intra-mammalian stages and is intended to focus the analysis solely on targets mediating protection. We report the results of this approach using two pools of sera from hi- and lo-responder macaques undergoing self-cure, to screen arrays comprising tegument, esophageal gland, and gastrodermis proteins. We show that, overall, the target epitopes are the same in both groups, but the intensity of response is twice as strong in the high responders. In addition, apart from Sm25, tegument proteins elicit much weaker responses than those originating in the alimentary tract, as was apparent in IFNγR KO mice. We also highlight the most reactive epitopes in key proteins. Armed with this knowledge, we intend to use multi-epitope constructs in vaccination experiments, which seek to emulate the self-cure process in experimental animals and potentially in humans.

Stem cell proliferation and differentiation during larval metamorphosis of the model tapeworm Hymenolepis microstoma.

Background: Tapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed de novo from a population of stem cells called germinative cells. This process is difficult to study for human pathogens, as these larvae are infectious and difficult to obtain in the laboratory. Methods: In this work, we analyzed cell proliferation and differentiation during larval metamorphosis in the model tapeworm Hymenolepis microstoma, by in vivo labelling of proliferating cells with the thymidine analogue 5-ethynyl-2'-deoxyuridine (EdU), tracing their differentiation with a suite of specific molecular markers for different cell types. Results: Proliferating cells are very abundant and fast-cycling during early metamorphosis: the total number of cells duplicates every ten hours, and the length of G2 is only 75 minutes. New tegumental, muscle and nerve cells differentiate from this pool of proliferating germinative cells, and these processes are very fast, as differentiation markers for neurons and muscle cells appear within 24 hours after exiting the cell cycle, and fusion of new cells to the tegumental syncytium can be detected after only 4 hours. Tegumental and muscle cells appear from early stages of metamorphosis (24 to 48 hours post-infection); in contrast, most markers for differentiating neurons appear later, and the detection of synapsin and neuropeptides correlates with scolex retraction. Finally, we identified populations of proliferating cells that express conserved genes associated with neuronal progenitors and precursors, suggesting the existence of tissue-specific lineages among germinative cells. Discussion: These results provide for the first time a comprehensive view of the development of new tissues during tapeworm larval metamorphosis, providing a framework for similar studies in human and veterinary pathogens.

Production and Characterization of Cellulosic Pulp from Mango Agro-Industrial Waste and Potential Applications.

The growing demand for cellulosic pulp presents an opportunity to explore alternatives to this material, focusing on utilizing agro-industrial residues. Mango's tegument is a rich source of cellulose, making it a valuable raw material for manufacturing single-use articles or blends with biopolymers. In this sense, employing conventional alkaline and acid chemical treatments, the mango's tegument was treated to obtain cellulosic pulp. The teguments were subjected to treatment with alkaline solutions (2% and 4% NaOH w/v) at 80 °C for 1 or 2 h or with an acetic acid solution (1:1 or 1:2 CH3COOH:H2O2) at 60-70 °C for 1 or 2 h. After treatment, an evaluation was conducted to assess the yield, color, chemical analysis, and structural, thermal, and morphological properties. The alkali treatments produced cellulosic pulps with a light color with 37-42% yield and reduced hemicellulose content. The acid treatments produced orange-brown cellulosic pulp with 47-48% yield and higher hemicellulose content. The acid pulps were thermally more stable (maximum decomposition at 348-357 °C) than the alkali pulps (maximum decomposition at 316-321 °C). The crystallinity index demonstrated that both treatments increased the crystallinity of the cellulose pulps compared with the untreated tegument. The thermal stability of cellulosic pulp at the processing temperatures of disposable tableware (50-120 °C) revealed that plates, bowls, trays, and cups could be produced. Another potential application is as a component of blends with biopolymers to make straws or rigid food packaging (trays) with reinforced structures.

Seed morphoanatomy of the genus Passiflora L. (Passifloraceae) by scanning electron microscopy and light microscopy.

Morphoanatomical analysis of seeds contributes to knowledge of the development of seedlings and identification of species, as well as supporting conservation studies. The conservation of the species belonging to the Passiflora genus is crucial due to of the threats to the genetic resources of these species. Thus, the objective of this study was to morphoanatomically characterize Passiflora seeds, verify possible injuries to the tissues after cryopreservation and thus contribute to the conservation strategies of the species of this genus. Initially, seeds of Passiflora coccinea, P. edulis, P. gibertii, P. maliformis, P. morifolia, P. setacea, P. suberosa, and P. tenuifila collected from the Passion Fruit Active Germplasm Bank of the Embrapa Cassava and Fruits research unit (Embrapa Mandioca e Fruticultura) were analyzed. Then, their length, width and thickness, shape of the base and tip, and ornamentations present on the body and edge of the seeds were evaluated. The seeds of the species were placed in cryotubes and immersed in liquid nitrogen to assess possible cryoinjuries. The tegument and tissues of the seeds were examined by scanning electron microscopy. The seeds had varied biometric data, with average values of 4.63 mm for length, 3.28 mm for width, and 1.51 mm for thickness. Six ornamentation types were observed: reticulate for the species P. coccinea; finely reticulate for P. edulis; foveolate reticulate for P. gibertii and P. setacea; alveolate reticulate for P. maliformis and P. tenuifila; coarsely reticulate for P. morifolia; and falsifoveolate reticulate for P. suberosa. Some seeds suffered tegument cracks due to the freezing in liquid nitrogen, but without physiological damages to the embryo and endosperm. The cryopreservation of the seeds in the presence of the tegument significantly reduced the cryoinjuries caused to the embryo. Cryopreservation can be promising for long-term conservation of passion fruit seeds.

Schistosome proteomics: updates and clinical implications.

INTRODUCTION: Schistosomes are long-lived blood dwelling helminth parasites using intricate mechanisms to invade, mature, and reproduce inside their vertebrate hosts, whilst simultaneously deploying immune evasion strategies. Their multi-tissue organization and solid body plan presents particular problems for the definition of sub-proteomes. AREAS COVERED: Here, we focus on the two host-parasite interfaces of the adult worm accessible to the immune system, namely the tegument and the alimentary tract, but also on the secretions of the infective cercaria, the migrating schistosomulum and the mature egg. In parallel, we introduce the concepts of "leakyome' and 'disintegrome' to emphasize the importance of interpreting data in the context of schistosome biology so that misleading conclusions about the distinct proteome compositions are avoided. Lastly, we highlight the possible clinical implications of the reviewed proteomic findings for pathogenesis, vaccine design and diagnostics. EXPERT OPINION: Proteomics has provided considerable insights into the biology of schistosomes, most importantly for rational selection of novel vaccine candidates that might confer protective immunity, but also into the pathogenesis of schistosomiasis. However, given the increasing sensitivity of mass spectrometric instrumentation, we stress the need for care in data interpretation since schistosomes do not deviate from the fundamental rules of eukaryotic cell biology.

Evolutionary Adaptations of Parasitic Flatworms to Different Oxygen Tensions.

During the evolution of the Earth, the increase in the atmospheric concentration of oxygen gave rise to the development of organisms with aerobic metabolism, which utilized this molecule as the ultimate electron acceptor, whereas other organisms maintained an anaerobic metabolism. Platyhelminthes exhibit both aerobic and anaerobic metabolism depending on the availability of oxygen in their environment and/or due to differential oxygen tensions during certain stages of their life cycle. As these organisms do not have a circulatory system, gas exchange occurs by the passive diffusion through their body wall. Consequently, the flatworms developed several adaptations related to the oxygen gradient that is established between the aerobic tegument and the cellular parenchyma that is mostly anaerobic. Because of the aerobic metabolism, hydrogen peroxide (H2O2) is produced in abundance. Catalase usually scavenges H2O2 in mammals; however, this enzyme is absent in parasitic platyhelminths. Thus, the architecture of the antioxidant systems is different, depending primarily on the superoxide dismutase, glutathione peroxidase, and peroxiredoxin enzymes represented mainly in the tegument. Here, we discuss the adaptations that parasitic flatworms have developed to be able to transit from the different metabolic conditions to those they are exposed to during their life cycle.

Electrical potentials of protoscoleces of the cestode Echinococcus granulosus from bovine origin.

Larval stages of taeniid Echinococcus granulosus are the infective forms of cystic echinococcosis or hydatidosis, a worldwide zoonosis. The protoscolex that develops into the adult form in the definitive host is enveloped by a complex cellular syncytial tegument, where all metabolic interchange takes place. Little information is available as to the electrical activity of the parasite in this developmental stage. To gain insight into the electrical activity of the parasite at the larval stage, we conducted microelectrode impalements of bovine lung protoscoleces (PSCs) of Echinococcus granulosus in standard saline solution. We observed two distinct intra-parasitic potentials, a transient peak potential, and a stable second potential, most likely representing tegumental and intra-parasitic extracellular space electrical potential differences. These values changed on the developmental status of the parasite, its anatomical regions, or time course after harvesting. Changes in electrical potential differences of the parasite provide an accessible and valuable parameter for the study of transport mechanisms and potential targets for developing novel antiparasitic therapeutics.

Epitope mapping of exposed tegument and alimentary tract proteins identifies putative antigenic targets of the attenuated schistosome vaccine

The radiation-attenuated cercarial vaccine remains the gold standard for the induction of protective immunity against Schistosoma mansoni. Furthermore, the protection can be passively transferred to naïve recipient mice from multiply vaccinated donors, especially IFNgR KO mice. We have used such sera versus day 28 infection serum, to screen peptide arrays and identify likely epitopes that mediate the protection. The arrays encompassed 55 secreted or exposed proteins from the alimentary tract and tegument, the principal interfaces with the host bloodstream. The proteins were printed onto glass slides as overlapping 15mer peptides, reacted with primary and secondary antibodies, and reactive regions detected using an Agilent array scanner. Pep Slide Analyzer software provided a numerical value above background for each peptide from which an aggregate score could be derived for a putative epitope. The reactive regions of 26 proteins were mapped onto crystal structures using the CCP4 molecular graphics, to aid selection of peptides with the greatest accessibility and reactivity, prioritizing vaccine over infection serum. A further eight MEG proteins were mapped to regions conserved between family members. The result is a list of priority peptides from 44 proteins for further investigation in multiepitope vaccine constructs and as targets of monoclonal antibodies.

Adaptability of brazilian beans cultivars to industrial canning / Adaptabilidade de cultivares brasileiras de feijão ao processamento industrial tipo enlatado

A current alternative for meeting the modern consumers beans food demands is the industrial processing. This study evaluated the adaptability of eight Brazilian beans cultivars to industrial canning from commercial class cultivars of Carioca and of Black beans. The grains were processed in an industry sector using metallic cans with a capacity of 420 g, where the samples were conditioned without previous hydration. The cooking and sterilization process took place in a rotating autoclave. Quality parameters were evaluated in the canned beans. As a result, it was verified that, for the Carioca class, the Estilo cultivar differs from the rest of the genetic materials in terms of its low drained weight, which contributes to the increase in the total solids in the sauce, which have low hardness values. Estilo cultivar is not suitable for the type of processing used in this experiment. For the Black class, similar quality characteristics were observed between Esplendor and Uirapuru and between Esteio and Campeiro cultivars, where the latter stands out due to its lower damaged bean indices after processing. Finally, with the information present in this paper we intend to contribute to future researches on this subject and thereby increase the consumption and exportation of beans as processed product.(AU)

Atualmente uma alternativa alimentar que atende às demandas do consumidor moderno é o processamento industrial do feijão. Foi avaliada a adaptabilidade de oito cultivares de feijão ao processamento industrial. Os grãos foram processados em uma indústria do setor, utilizando-se embalagens metálicas com capacidade de 420 g, nas quais as amostras foram acondicionadas sem o emprego de hidratação prévia. O processo de cozimento e esterilização foi realizado em autoclave rotativa. No feijão enlatado foram então avaliados os parâmetros de qualidade. Como resultado, verificou-se que, na classe Carioca, o cultivar BRS Estilo diferencia-se dos demais, devido ao baixo peso drenado que contribuiu para o aumento de sólidos totais no caldo, com baixos valores de dureza, não se adaptando ao tipo de processo utilizado neste experimento. Na classe Preto, observaram-se características de qualidade semelhantes entre BRS Esplendor e IPR Uirapuru, e entre BRS Esteio e BRS Campeiro, destacando-se esta última por apresentar menores índices de grãos danificados após o processamento. Por fim, com as informações presentes neste trabalho pretende-se contribuir com pesquisas futuras sobre o tema e dessa forma incrementar o consumo do feijão e sua exportação na forma de produto processado.(AU)

Linking murine resistance to secondary cystic echinococcosis with antibody responses targeting Echinococcus granulosus tegumental antigens.

Successful establishment of a parasite infection depends partially on the host intrinsic susceptibility to the pathogen. In cystic echinococcosis (CE), a zoonotic disease caused by the cestode parasite Echinococcus granulosus, the infection outcome in the murine model of secondary CE varies according to the mouse strain used. In this regard, intrinsic differences in susceptibility to the infection were previously reported for Balb/c and C57Bl/6 mice, being C57Bl/6 animals less permissive to secondary CE. Induction of parasite-specific antibodies has been suggested to play relevant roles in such susceptibility/resistance phenomena. Here, we report an in deep comparison of antibody responses induced in both mouse strains. Firstly, only C57Bl/6 mice were shown to induce specific-antibodies with efficient anti-parasite activities during early secondary CE. Then, through ImmunoTEM and Serological Proteome Analysis (SERPA), an evaluation of specific antibody responses targeting parasite tegumental antigens was performed. Both strategies showed that infected C57Bl/6 mice -unlike Balb/c animals- narrowed their IgG recognition repertoire against tegumental antigens, targeting fewer but potentially more relevant parasite components. In this sense, tegumental antigens recognition between Balb/c and C57Bl/6 mice, either by natural and/or induced antibodies, was analyzed through SERPA and MALDI-TOF/TOF studies. A total of 13 differentially recognized proteins (DRPs) uniquely targeted by antibodies from C57Bl/6 mice were successfully identified, wherein a subset of 7 DRPs were only recognized by infection-induced antibodies, suggesting their potential as natural protective antigens. In this regard, immunoinformatic analyses showed that such DRPs exhibited higher numbers of possible T cell epitopes towards the H-2-IAb haplotype, which is present in C57Bl/6 mice but absent in Balb/c animals. In summary, our results showed that the genetic predisposition to generate better T-dependent antibody responses against particular tegumental antigens might be a key factor influencing host susceptibility in the murine model of secondary CE.

Epitope Mapping of Exposed Tegument and Alimentary Tract Proteins Identifies Putative Antigenic Targets of the Attenuated Schistosome Vaccine.

The radiation-attenuated cercarial vaccine remains the gold standard for the induction of protective immunity against Schistosoma mansoni. Furthermore, the protection can be passively transferred to naïve recipient mice from multiply vaccinated donors, especially IFNgR KO mice. We have used such sera versus day 28 infection serum, to screen peptide arrays and identify likely epitopes that mediate the protection. The arrays encompassed 55 secreted or exposed proteins from the alimentary tract and tegument, the principal interfaces with the host bloodstream. The proteins were printed onto glass slides as overlapping 15mer peptides, reacted with primary and secondary antibodies, and reactive regions detected using an Agilent array scanner. Pep Slide Analyzer software provided a numerical value above background for each peptide from which an aggregate score could be derived for a putative epitope. The reactive regions of 26 proteins were mapped onto crystal structures using the CCP4 molecular graphics, to aid selection of peptides with the greatest accessibility and reactivity, prioritizing vaccine over infection serum. A further eight MEG proteins were mapped to regions conserved between family members. The result is a list of priority peptides from 44 proteins for further investigation in multiepitope vaccine constructs and as targets of monoclonal antibodies.

Adaptability of brazilian beans cultivars to industrial canning / Adaptabilidade de cultivares brasileiras de feijão ao processamento industrial tipo enlatado

ABSTRACT: A current alternative for meeting the modern consumer's beans food demands is the industrial processing. This study evaluated the adaptability of eight Brazilian beans cultivars to industrial canning from commercial class cultivars of Carioca and of Black beans. The grains were processed in an industry sector using metallic cans with a capacity of 420 g, where the samples were conditioned without previous hydration. The cooking and sterilization process took place in a rotating autoclave. Quality parameters were evaluated in the canned beans. As a result, it was verified that, for the Carioca class, the Estilo cultivar differs from the rest of the genetic materials in terms of its low drained weight, which contributes to the increase in the total solids in the sauce, which have low hardness values. Estilo cultivar is not suitable for the type of processing used in this experiment. For the Black class, similar quality characteristics were observed between Esplendor and Uirapuru and between Esteio and Campeiro cultivars, where the latter stands out due to its lower damaged bean indices after processing. Finally, with the information present in this paper we intend to contribute to future researches on this subject and thereby increase the consumption and exportation of beans as processed product.

RESUMO: Atualmente uma alternativa alimentar que atende às demandas do consumidor moderno é o processamento industrial do feijão. Foi avaliada a adaptabilidade de oito cultivares de feijão ao processamento industrial. Os grãos foram processados em uma indústria do setor, utilizando-se embalagens metálicas com capacidade de 420 g, nas quais as amostras foram acondicionadas sem o emprego de hidratação prévia. O processo de cozimento e esterilização foi realizado em autoclave rotativa. No feijão enlatado foram então avaliados os parâmetros de qualidade. Como resultado, verificou-se que, na classe Carioca, o cultivar BRS Estilo diferencia-se dos demais, devido ao baixo peso drenado que contribuiu para o aumento de sólidos totais no caldo, com baixos valores de dureza, não se adaptando ao tipo de processo utilizado neste experimento. Na classe Preto, observaram-se características de qualidade semelhantes entre BRS Esplendor e IPR Uirapuru, e entre BRS Esteio e BRS Campeiro, destacando-se esta última por apresentar menores índices de grãos danificados após o processamento. Por fim, com as informações presentes neste trabalho pretende-se contribuir com pesquisas futuras sobre o tema e dessa forma incrementar o consumo do feijão e sua exportação na forma de produto processado.

Efficacy of silver nanoparticles against the adults and eggs of monogenean parasites of fish.

Monogeneans are a diverse group of parasites that are commonly found on fish. Some monogenean species are highly pathogenic to cultured fish. The present study aimed to determine the in vitro anthelmintic effect of silver nanoparticles (AgNPs) against adults and eggs of monogeneans in freshwater using Cichlidogyrus spp. as a model organism. We tested two types of AgNPs with different synthesis methodologies and size diameters: ARGOVIT (35 nm) and UTSA (1-3 nm) nanoparticles. Damage to the parasite tegument was observed by scanning electron microscopy. UTSA AgNPs were more effective than ARGOVIT; in both cases, there was a concentration-dependent effect. A concentration of 36 µg/L UTSA AgNPs for 1 h was 100% effective against eggs and adult parasites, causing swelling, loss of corrugations, and disruption of the parasite's tegument. This is an interesting result considering that monogenean eggs are typically tolerant to antiparasite drugs and chemical agents. To the best of our knowledge, no previous reports have assessed the effect of AgNPs on any metazoan parasites of fish. Therefore, the present work provides a basis for future research on the control of fish parasite diseases.

Combining proteomics and bioinformatics to explore novel tegumental antigens as vaccine candidates against Echinococcus granulosus infection.

Echinococcus granulosus is the parasite responsible for cystic echinococcosis (CE), an important worldwide-distributed zoonosis. New effective vaccines against CE could potentially have great economic and health benefits. Here, we describe an innovative vaccine design scheme starting from an antigenic fraction enriched in tegumental antigens from the protoscolex stage (termed PSEx) already known to induce protection against CE. We first used mass spectrometry to characterize the protein composition of PSEx followed by Gene Ontology analysis to study the potential Biological Processes, Molecular Functions, and Cellular Localizations of the identified proteins. Following, antigenicity predictions and determination of conservancy degree against other organisms were determined. Thus, nine novel proteins were identified as potential vaccine candidates. Furthermore, linear B cell epitopes free of posttranslational modifications were predicted in the whole PSEx proteome through colocalization of in silico predicted epitopes within peptide fragments identified by matrix-assisted laser desorption/ionization-TOF/TOF. Resulting peptides were termed "clean linear B cell epitopes," and through BLASTp scanning against all nonhelminth proteins, those with 100% identity against any other protein were discarded. Then, the secondary structure was predicted for peptides and their corresponding proteins. Peptides with highly similar secondary structure respect to their parental protein were selected, and those potentially toxic and/or allergenic were discarded. Finally, the selected clean linear B cell epitopes were mapped within their corresponding 3D-modeled protein to analyze their possible antibody accessibilities, resulting in 14 putative peptide vaccine candidates. We propose nine novel proteins and 14 peptides to be further tested as vaccine candidates against CE.

Usnic acid potassium salt from Cladonia substellata (Lichen): Synthesis, cytotoxicity and in vitro anthelmintic activity and ultrastructural analysis against adult worms of Schistosoma mansoni.

We report for the first time the in vitro effect of Potassium Salt, derived from Usnic Acid (PS-UA), isolated from the lichen Cladonia substellata Vanio, on couples of Schistosoma mansoni. As schistosomicide parameters, we evaluated mortality, motility, cell viability of the worms and tegument changes by scanning electron microscopy (SEM). Exposure to a concentration of 100 µM caused 75% mortality after 3 h. After 6 h, changes in motility in concentrations of 50 and 25 µM are evidenced. After 12 h and 24h, the concentrations of 50 and 100 µM caused 6.25% and 87.5% and 50% and 100% mortality, respectively. PS-UA reduced the cell viability of the worms by 27.36% and 52.82% at concentrations 50 and 100 µM, respectively. Through SEM we observed progressive dose-and time-dependent, alterations such as swelling, blisters, dorsoventral contraction, erosion until disintegration of the tubercles in the tegument of male and female. PS-UA did not alter the viability of human peripheral blood mononuclear cells and showed high selectivity indices (IC50 > 200 µM). Our results indicate that PS-UA represents a possible candidate for a new anthelmintic drug in the control of schistosomiasis.

Excessive luminosity fades the skin color of cardinal tetra / Luminosidade excessiva reduz a coloração da pele do cardinal tetra

In order to understand the morphological and physiological changes on the loss of coloration in the tegument of cardinal tetra under excessive luminosity, specimens of Paracheirodon axelrodi were conditioned to different light intensities (0, 250, 500, 1,200 and 2,700 lux) at different time intervals (0, 12, 24 and 72 hours). Types of chromatophores, dispersion of melanosomes and density of chromatophores were analyzed after the experiment. The dark stripe on the species consists of yellowish-brown (dorsally located) and darkish-brown (medially located) melanophores. In the iridescent blue stripe, darkish-brown melanophores were closely associated with iridophores. Erythrophores were found only in the red stripe. Loss of skin color was observed when cardinal tetra was exposed to intense light. The melanic and neon stripes became pale due to a reduction in melanophores densities. On the other hand, the color of the red stripe was intensified due to the proliferation of erythrophores. At low light levels (0 to 250 lux), the melanophores (with dispersed melanosomes) proliferate in the black and neon stripes resulting in a more vibrant skin color. We suggest that in nature, the paleness of the skin may represent a camouflage strategy during the hours of the day with greater luminosity in the black water of the Rio Negro. Fading the skin color can help this species to visually confuse potential predators.

Para compreender as mudanças morfológicas e fisiológicas da perda da coloração no tegumento do cardinal após exposição à luminosidade, exemplares de Paracheirodon axelrodi foram submetidos a diferentes intensidades luminosas (0, 250, 500, 1.200 e 2.700 lux), em diferentes intervalos de tempo (0, 12, 24 e 72 horas). Após a exposição, foram analisadas a dispersão dos melanossomos e a densidade de cromatóforos. A faixa de coloração escura do cardinal é constituída por melanóforos de coloração marrom-amarelado (dorsalmente localizados) e marrom-escuro (latero-medial). Na faixa azul iridescente, os melanóforos de cor marrom-escuro estão intimamente associados aos iridóforos. Eritróforos foram encontrados apenas na faixa vermelha. Observou-se que a perda da coloração ocorre devido à exposição pela luminosidade excessiva. As faixas melânica e neon tornam-se pálidas devido à redução na densidade dos melanóforos, enquanto a faixa vermelha intensifica-se como resultado da proliferação de eritróforos. Em baixa luminosidade (0 a 250 lux), os melanóforos (com melanossomos dispersos) proliferam-se nas faixas melânica e neon realçando ainda mais as cores vibrantes do cardinal. Nós sugerimos que na natureza a palidez pode representar um padrão de camuflagem durante as horas de intensa luminosidade nas águas pretas do rio Negro. A redução da coloração na pele pode ajudar o cardinal a confundir potenciais predadores visuais.

Excessive luminosity fades the skin color of cardinal tetra / Luminosidade excessiva reduz a coloração da pele do cardinal tetra

In order to understand the morphological and physiological changes on the loss of coloration in the tegument of cardinal tetra under excessive luminosity, specimens of Paracheirodon axelrodi were conditioned to different light intensities (0, 250, 500, 1,200 and 2,700 lux) at different time intervals (0, 12, 24 and 72 hours). Types of chromatophores, dispersion of melanosomes and density of chromatophores were analyzed after the experiment. The dark stripe on the species consists of yellowish-brown (dorsally located) and darkish-brown (medially located) melanophores. In the iridescent blue stripe, darkish-brown melanophores were closely associated with iridophores. Erythrophores were found only in the red stripe. Loss of skin color was observed when cardinal tetra was exposed to intense light. The melanic and neon stripes became pale due to a reduction in melanophores densities. On the other hand, the color of the red stripe was intensified due to the proliferation of erythrophores. At low light levels (0 to 250 lux), the melanophores (with dispersed melanosomes) proliferate in the black and neon stripes resulting in a more vibrant skin color. We suggest that in nature, the paleness of the skin may represent a camouflage strategy during the hours of the day with greater luminosity in the black water of the Rio Negro. Fading the skin color can help this species to visually confuse potential predators.(AU)

Para compreender as mudanças morfológicas e fisiológicas da perda da coloração no tegumento do cardinal após exposição à luminosidade, exemplares de Paracheirodon axelrodi foram submetidos a diferentes intensidades luminosas (0, 250, 500, 1.200 e 2.700 lux), em diferentes intervalos de tempo (0, 12, 24 e 72 horas). Após a exposição, foram analisadas a dispersão dos melanossomos e a densidade de cromatóforos. A faixa de coloração escura do cardinal é constituída por melanóforos de coloração marrom-amarelado (dorsalmente localizados) e marrom-escuro (latero-medial). Na faixa azul iridescente, os melanóforos de cor marrom-escuro estão intimamente associados aos iridóforos. Eritróforos foram encontrados apenas na faixa vermelha. Observou-se que a perda da coloração ocorre devido à exposição pela luminosidade excessiva. As faixas melânica e neon tornam-se pálidas devido à redução na densidade dos melanóforos, enquanto a faixa vermelha intensifica-se como resultado da proliferação de eritróforos. Em baixa luminosidade (0 a 250 lux), os melanóforos (com melanossomos dispersos) proliferam-se nas faixas melânica e neon realçando ainda mais as cores vibrantes do cardinal. Nós sugerimos que na natureza a palidez pode representar um padrão de camuflagem durante as horas de intensa luminosidade nas águas pretas do rio Negro. A redução da coloração na pele pode ajudar o cardinal a confundir potenciais predadores visuais.(AU)

Germinação de sementes e emergência de plântulas de jutaí (Hymenaea parvifolia Huber. ) / Seed germination and emergence of jutai (Hymenaea parvifolia Huber. ) seedlings

RESUMO O objetivo do presente trabalho foi avaliar a influencia do tamanho e da temperatura na germinação das sementes, assim como, da posição de escarificação do tegumento e a profundidade de semeadura na emergência de plântulas de jutaí. As sementes foram separadas em três grupos: sementes pequenas, médias e grandes. A germinação das sementes foram realizadas nas temperaturas de 5, 10, 15, 20, 25, 30, 35, 40 e 45 °C e com fotoperíodo de 12 horas. As sementes escarificadas foram colocadas para germinar em 0, 2, 4 e 6 cm de profundidade de semeadura. As sementes médias e grandes apresentaram maiores porcentagens e índices de velocidade de germinação. A faixa de temperatura ótima de germinação está entre 25 e 35°C. A escarificação no hilo da semente ou não é adequada para quebra de dormência de sementes de jutaí. Profundidades de semeadura iguais ou superiores a 4 cm são inadequadas para a emergência de plântulas de jutaí.

ABSTRACT The objective of this study was to evaluate the influence of seed size and temperature on seed germination, as well as the scarification position of the tegument and sowing depth on the emergence of jutai seedlings. The seeds were separated into three groups: large, medium and small. The temperatures to which the seeds were subjected for germination were 5, 10, 15, 20, 25, 30, 35, 40, and 45°C under a photoperiod of 12 hours. The scarified seeds were placed to germinate at depths of 0, 2, 4, and 6 cm. Seed germination was affected by seed size (large and medium seeds). The optimum temperature range was found to be between 25 and 35°C. The scarification in the hilum or the tegument was enough to break the dormancy of the jutai seeds. Sowing depths equal to or deeper than 4 cm were found to be inadequate for the emergence of jutai seedlings.

Tumor maligno derivado de melanocitos en piel de un bovino de presentación inusual: estudio de caso / Malignant Tumor Derived from Skin Melanocytes of a Bovine of Unusual Presentation: A Case Study / Tumor maligno derivado de melanócitos na pele de um bovino de apresentação incomum: estudo de caso

Los tumores melanocíticos o melanomas en los animales domésticos incluyen neoplasias compuestas por células productoras de melanina. En los bovinos, estos tumores son poco frecuentes y la mayoría son benignos; mientras que los malignos son de poca presentación. El artículo registra el caso de un bovino hembra mestizo de 38 meses de edad con una masa fluctuante, localizada entre el borde mandibular y la región parotídea izquierda, de aproximadamente tres meses de evolución, con crecimiento más evidente en los últimos treinta días. Después de su escisión quirúrgica, se remite una muestra conservada en formalina tamponada al 10 % al Laboratorio de Patología de la Universidad de Nariño, consistente en un fragmento de 7,0 x 10,5 x 8,0 cm, de forma elipsoide, con piel y pelo en una de sus caras, superficie irregular, color pardo negruzco, consistencia semiblanda al corte y presencia de contenido translúcido de aspecto viscoso para el procesamiento e inclusión en parafina y cortados a 5 de espesor y tincionados con coloración de hematoxilina-eosina. El tejido remitido se catalogó como una neoplasia de comportamiento maligno derivada de melanocitos, debido a sus características celulares: patrón de crecimiento, patrón de distribución, severo pleomorfismo celular, anisocitosis, megalocitosis, pleomorfismo nuclear, anisocariosis, megalocariosis y afectación de las paredes de los vasos sanguíneos; adicionalmente, al bloque de parafina se le realizó un corte para procesamiento inmunohistoquímico, empleando los marcadores monoclonales S-100 DAKO® y Melan A DAKO®, contrastado con hematoxilina de Meyer. Se evidencia fuerte inmunomarcación de las células neoplásicas, y se constituye en el primer caso registrado de esta patología en Nariño (Colombia).

Melanocytic tumors and melanomas in domestic animals include neoplasms composed of melanin-producing cells. In cattle, these tumors are rare and mostly benign, while malignant tumors are almost non-existent. The article reports the case of a female crossbred cow 38 months of age with a fluctuating mass located between the mandibular border and the left parotid region, about three months duration, with evident growth in the last thirty days. After surgical excision, a sample preserved in buffered formalin (10%) was sent to the Laboratory of Pathology (University of Nariño)-consisting of a fragment of 7.0 x 10.5 x 8.0 cm, ellipsoid, with skin and hair on one side, irregular surface, blackish brown, semi-soft consistency, and presence of shear translucent slimy content-for processing and inclusion in paraffin, cut to 5 µm thickness and stained with hematoxylin-eosin coloration. The forwarded tissue was classified as a neoplasm of malignant behavior derived from melanocytes, due to its cellular characteristics: growth pattern, pattern of distribution, severe cellular pleomorphism, anisocytosis, megalocytosis, nuclear pleomorphism, anisokaryosis, megalokaryosis, and involvement of blood vessel walls; additionally, the paraffin block was cut for immunohistochemical processing using monoclonal markers (S-100 DAKO® and Melan A DAKO®), contrasted with Mayer's hematoxylin. Strong immunostaining of neoplastic cells is evident, and it constitutes the first reported case of this disease in Nariño (Colombia).

Os tumores melanócitos ou melanomas nos animais domésticos incluem neoplasias compostas por células produtoras de melanina. Nos bovinos, estes tumores são pouco frequentes e na maioria das vezes são benignos; enquanto que os malignos são de pouca apresentação. O artigo relata o caso de uma fêmea bovino mestiça de 38 meses de idade com uma massa flutuante, localizada entre a borda da mandíbula e a região parotídea esquerda, de aproximadamente três meses de evolução, com crescimento mais evidente nos últimos trinta dias. Depois de sua excisão cirúrgica, se remete uma amostra conservada em formalina tamponada ao 10 % ao Laboratório de Patologia da Universidade de Nariño, consistente em um fragmento de 7,0 X 10,5 x 8,0 cm, de forma elipsoide, com pele e pelo em uma de suas caras, superfície irregular, color pardo enegrecido, consistência semi-suave ao corte e presença de conteúdo translúcido de aspecto viscoso para o processamento e inclusão em parafina e cortados a 5 de espessura e com coloração de hematoxilina-eosina. O tecido remetido se catalogou como uma neoplasia de comportamento maligno derivada de melanócitos, devido às suas características celulares: padrão de crescimento, padrão de distribuição, severo pleomorfismo celular, anisocitose, megalocitose, pleomorfismo nuclear, anisocariose, "megalocariose" e afetação das paredes dos vasos sanguíneos; adicionalmente, se realizou ao bloco de parafina um corte para processamento imuno-histoquímica, empregando os marcadores monoclonais S-100 DAKO® e Melam A DAKO®, contrastado com hematoxilina de Meyer. Evidencia-se forte imuno- marcação das células neoplásicas, e se constitui no primeiro caso reportado desta patologia em Nariño (na Colômbia).

Stereoscopy and scanning electron microscopy of Brazil nut (Bertholletia excelsa H.B.K.) shell, brown skin, and edible part: part one--healthy nut.

UNLABELLED: In this article, tissue layers and cells characteristics of the Brazil nut (Bertholletia excelsa H.B.K.) shell (tegument), brown skin (testae), and edible part (cotyledons) were identified by stereoscopy (SM) and scanning electron microscopies (SEM). (a) The shell (a lignin rich, protective wall) varies in thickness throughout the nut structure and comprises different tissue types (total 3)/texture (hard/mid-hard/soft), layers (2 to 5), colors (light to dark brown and white to cream), cell shape (amorphous/flattened on both surfaces; polygonal and cylindrical with thick, porous primary and secondary wall in cross-section), and vascular distribution (helically and polyedrical thickened vessels at soft tissue and locule/channel structures). These variations are observed either in the shell faces, face corners, nut tips, or locule in testae. (b) The brown skin (shell nut part linked to both the shell and edible part) is made of flattened irregular-shaped parenchymal cells distributed in several layers with more flexible fibrous, thinner wall tissue than shell. It has both rough and smooth shiny texture on the upper and lower surfaces, respectively. However, the nut (c) edible part, that is the nut storage tissue, shows several different tissue/cell layers starting from epidermis (double/triple cells sequence of round and palisade shapes) layer-the endosperm tissue. The parenchymal tissues show cells of irregular shape with small and larger sizes distributed in regular and randomly layers, respectively, separated by a short meristem tissue layer. The cortex cells increase in size as they approach the cotyledons junction. The Brazil nut part's tissue layers and cells were identified by the SM and SEM microscopy methods applied, which provides knowledge for further understanding of nut alterations that may occur either in the forest or during the factory processing. PRACTICAL APPLICATION: Knowledge about the characteristics and nature of the waste woody tissues from the Brazil nut factories is of interest for potential applications in the industry. Understanding the nut tissues and cells structures helps in judging how much whole nut edible part gets spoiled/deteriorated (either raw or processed), for further development of procedures to prevent and/or control such spoiling/deterioration for achieving nut quality and safety (to be discussed in Part Two).