404 research outputs found
Células Germinativas E Espermatogênese Do Lagarto Tropidurus Torquatus (tropiduridae) De Uma área Urbana No Bioma Cerrado Do Centro-oeste Brasileiro
Tropidurus comprises a Neotropical genus of lizard that currently has about 30 species widely distributed in the South American. Among these species, Tropidurus torquatus, which has the characteristic of great physiological plasticity, occupying a variety of habitats in open areas and urbanized environments. Considering this, the aim of the study was to investigate the germinative cells and spermatogenesis of a population of T. torquatus in an urban area under Cerrado Biome influences to understand how to establish the temporal development of germinative cells and spermatogenesis during a period of one year. Individuals were obtained in the Zoological Collection of Vertebrates at the Universidade Federal de Mato Grosso (UFMT), and the germinative cells and full spermatogenesis were described with light microscopy. Tropidurus torquatus presented germ cells with similar characteristics already documented for the other species of lizards and reptiles. Spermatogonia type A and B, primary and secondary spermatocytes, and spermatids were present in almost all months evaluated. The gonadosomatic ratio presented its highest value in October, moment in which spermatogenesis presented all the germinative cells and spermatozoa in the lumen, of the seminiferous tubules. In the seasonal climate of the Cerrado Biome, we observe discontinuous spermatogenesis in T. torquatus with the production of spermatozoa in almost every month of the year, however with sperm storage in the epididymis during the phase of testicular regression. © 2016, Universidade Federal de Uberlandia. All rights reserved.3261595160
Use Of Blends Bioabsorbable Poly(l-lactic Acid)/poly(hydroxybutyrate-co-hydroxyvalerate) As Surfaces For Vero Cell Culture
Vero cells, a cell line established from the kidney of the African green monkey (Cercopithecus aethiops), were cultured in F-10 Ham medium supplemented with 10% fetal calf serum at 37°C on membranes of poly(L-lactic acid) (PLLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and their blends in different proportions (100/0, 60/40, 50/50, 40/60, and 0/100). The present study evaluated morphology of cells grown on different polymeric substrates after 24 h of culture by scanning electron microscopy. Cell adhesion was also analyzed after 2 h of inoculation. For cell growth evaluation, the cells were maintained in culture for 48, 120, 240, and 360 h. For cytochemical study, the cells were cultured for 120 or 240 h, fixed, processed for histological analysis, and stained with Toluidine blue, pH 4.0, and Xylidine ponceau, pH 2.5. Our results showed that cell adhesion was better when 60/40 and 50/50 blends were used although cells were able to grow and proliferate on all blends tested. When using PLLA/PHBV (50/50) slightly flattened cells were observed on porous and smooth areas. PLLA/PHBV (40/60) blends presented flattened cells on smooth areas. PLLA/PHBV (0/100), which presented no pores, also supported spreading cells interconnected by thin filaments. Histological sections showed that cells grew as a confluent monolayer on different substrates. Cytochemical analysis showed basophilic cells, indicating a large amount of RNA and proteins. Hence, we detected changes in cell morphology induced by alterations in blend proportions. 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Characteristics of the Male Reproductive System and Spermatozoa of Leptophlebiidae (Ephemeroptera)
This study describes morphological changes in the male reproductive system of Miroculis amazonicus (Savage & Peters) from mature nymphs to subimago stages. The sperm ultrastructure of Massartela brieni (Lestage), Farrodes carioca (Domínguez et al) and Miroculis mourei (Savage & Peters), as well as aspects of cell fragments observed in these species' subimagos deferent ducts were described. Sperm from the three species studied are aflagellated and immotile, while those from F. carioca and Ma. brieni are approximately spherical with a homogenous nucleus and acrosome. Sperm of F. carioca present two or three mitochondria located between the nucleus and the acrosome. In Ma. brieni, only one lateral mitochondria was found. Sperm from Mi. mourei are shaped as a number 'eight', with electron lucent spots inside the nucleus and two mitochondria above the acrosome. Large cell fragments containing degenerative vesicles and some sperm were observed in the deferent duct lumen of the three species. Testes of Mi. amazonicus are extremely reduced in the subimago stage, which suggests that these cell fragments originated from testes degeneration.103107Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Standing united or falling divided? High stakes bargaining in a TV game show
We examine high stakes three-person bargaining in a game show where contestants bargain over a large money amount that is split into three unequal shares. We find that individual behavior and outcomes are strongly influenced by equity concerns: those who contributed more to the jackpot claim larger shares, are less likely to make concessions, and take home larger amounts. Contestants who announce that they will not back down do well relative to others, but they do not secure larger absolute amounts and they harm others. There is no evidence of a first-mover advantage and little evidence that demographic characteristics matter
Dados preliminares sobre partículas semelhantes a virus em células de triatomíneos
Viral particles distributed within cytolysomes or other cytoplasmic globule types, giving rise to membrane enclosed paracrystalline arrays, and between membranes of contiguous cells, were found in the Malpighian tubes of Triatoma infestans Klug and Panstrongylus megistus Burmeister. Other tissues of the same insects also display paracrystalline arrays of these viruses. A RNP composition is assumed for the viruses based on their response to cytochemical methods at the EM level. Drastic morphological changes were not found in the injected tissues. This infection assumed to be promoted by ingestion of a bird infected blood meal.Nos tubos de Malpighi de Triatoma infestans Klug e de Panstrongylus megistus Burmeister foram encontradas estruturas víricas distribuídas no citoplasma, no interior de citolissomos ou outros tipos de glóbulos, formando às vezes arranjos para cristalinos envolvidos por membrana, e entre plasmalemas de células contíguas. Outros tecidos dos mesmos insetos apresentam arranjos paracristalinos desses virus. A análise citoquímica ao nível da microscopia eletrônica indica serem estes virus compostos de RNP. Não são encontradas alterações morfológicas drásticas nos tecidos infectados. Admite-se que tais virus tenham sido ingeridos durante uma alimentação de sangue infectado de ave
Mudanças sazonais na histologia do testículo e epidídimo do lagarto tropical Tropidurus itambere, durante seu ciclo reprodutivo
The reproductive cycles of lizards, including Tropidurus species, have been widely studied. However, few studies describe in detail the ultrastructure and the epithelial changes in the epididymis. Using histology and trasmission electron microscopy, we show the seasonal changes in the testis and epididymis of the lizard Tropidurus itambere, during its annual reproductive cycle. The reproductive cycle of T. itambere was analysed from June 1988 to June 1989 and from June 2001 to June 2002. While the frequency of reproductive males in the population varied throughout the year, there were reproductive males in most months except for February through April. During this nonreproductive period, there is a reduction in the mean seminiferous tubule volume and few sperm were found in both the testis and the epididymis.O ciclo reprodutivo de alguns lagartos já foi extensamente estudado, incluindo algumas espécies do gênero Tropidurus. Entretanto, poucos estudos mostram os aspectos morfológicos do testículo e epidídimo, durante o ciclo reprodutivo anual, e não existe nenhuma descrição ultraestrutural das variações epiteliais no epidídimo. O presente estudo foi feito para mostrar, através da histologia e microscopia eletrônica de transmissão, detalhes das mudanças sazonais no testículo e epidídimo durante o ciclo reprodutivo anual. Acompanhamos o ciclo de Tropidurus itambere, na floresta atlântica brasileira, durante o período de junho de 2001 a junho de 2002. Os machos variam em sua atividade reprodutiva, mas foram considerados potencialmente reprodutivos na maioria dos meses, à exceção dos meses de fevereiro a abril. Durante este período, ocorreu uma redução no volume médio dos túbulos seminíferos e uma menor quantidade de espermatozóides no testículo e no epidídimo.429435Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Ultrastructural and biochemical changes induced by salt stress in jatropha curcas seeds during germination and seedling development
Jatropha curcas L. is a multipurpose species of the Euphorbiaceae family that is widespread in arid and semiarid regions. This study investigated the ultrastructural and biochemical changes induced by salt stress during J. curcas seed germination and seedling development. Salt stress negatively affected seed germination and increased Na+ and Cl– contents in endosperms and embryo-axis. Lipids represented the most abundant reserves (64% of the quiescent seed dry mass), and their levels were strongly decreased at 8 days after imbibition (DAI) under salinity stress. Proteins were the second most important reserve (21.3%), and their levels were also reduced under salt stress conditions. Starch showed a transient increase at 5 DAI under control conditions, which was correlated with intense lipid mobilisation during this period. Non-reducing sugars and free amino acids were increased in control seeds compared with quiescent seeds, whereas under the salt-stress conditions, minimal changes were observed. In addition, cytochemical and ultrastructural analyses confirmed greater alterations in the cellular reserves of seeds that had been germinated under NaCl stress conditions. Salt stress promoted delays in protein and lipid mobilisation and induced ultrastructural changes in salt-stressed endosperm cells, consistent with delayed protein and oil body degradation4286587
Use of blends of bioabsorbable poly(L-lactic acid)/poly(hydroxybutyrate-co-hydroxyvalerate) as surfaces for Vero cell culture
Vero cells, a cell line established from the kidney of the African green monkey (Cercopithecus aethiops), were cultured in F-10 Ham medium supplemented with 10% fetal calf serum at 37 degrees C on membranes of poly(L-lactic acid) (PLLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and their blends in different proportions (100/0, 60/40, 50/50, and 0/100). The present study evaluated morphology of cells 40/60, grown on different polymeric substrates after 24 h of culture by scanning electron microscopy. Cell adhesion was also analyzed after 2 h of inoculation. For cell growth evaluation, the cells were maintained in culture for 48, 120, 240, and 360 h. For cytochemical study, the cells were cultured for 120 or 240 h, fixed, processed for histological analysis, and stained with Toluidine blue, pH 4.0, and Xylidine ponceau, pH 2.5. Our results showed that cell adhesion was better when 60/40 and 50/50 blends were used although cells were able to grow and proliferate on all blends tested. When using PLLA/PHBV (50150) slightly flattened cells were observed on porous and smooth areas. PLLA/PHBV (40/60) blends presented flattened cells on smooth areas. PLLA/PHBV (0/100), which presented no pores, also supported spreading cells interconnected by thin filaments. Histological sections showed that cells grew as a confluent monolayer on different substrates. Cytochemical analysis showed basophilic cells, indicating a large amount of RNA and proteins. Hence, we detected changes in cell morphology induced by alterations in blend proportions. This suggests that the cells changed their differentiation pattern when on various PLLA/PHBV blend surfaces.38111623163
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