Ivanira José Bechara

Histological study of the dynamics in epidermis regeneration of the carp tail fin (Cyprinus carpio, Linnaeus, 1758)

Teleostean fins when partially amputated suffer a regenerative process called epimorphic regeneration, characterized by the following stages: healing, based on the formation of a multistratified epidermal layer, the formation of a mass of pluripotent cells known as blastema, the differentiation of these cells, the synthesis and disposition of the extracellular matrix, morphological growth and restoration. The epidermis has a fundamental role in the regenerative process of fish fins, as the healing time of this structure leads it to a faster regenerative process and it also works as a defense against the external environment. In this sense, due to the fast regeneration shown by the epidermis, the aim of this paper is to study the histology of the regenerative dynamics of the carp fin tail (Cyprinus carpio), under the light and transmission electron microscope. Epidermic regeneration begins right in the first hours after the fin amputation and it continues throughout the regenerative process. After 24 hours, an apical epidermal cap is established. Cytoplasmatic prolongations and intercellular junctions are observed and the cells of the basal layer of the epidermis change from the cubic form to the cylindrical, due to the development of the cytoplasmatic organelles responsible for the synthesis of the basal membrane, lost after amputation. These results show the importance of histological studies in regenerative processes. We believe that the association of molecular biology with histological studies can throw further light onto these regenerative dynamics.

Effectiveness of Metarhizium anisopliae against immature stages of Anastrepha fraterculus fruitfly (Diptera : Tephritidae)

The study evaluated the effectiveness of Metarhizium anisopliae var. anisopliae (Hyphomycetes : Moniliales) strain E9, isolated from the pasture spittlebug Deois flavopicta (Hemiptera : Cercopidae), against larvae, prepupae and pupae stage and emergent adults of Anastrepha fraterculus, the South American fruitfly. The bioassay was carried out simulating field conditions, on autoclaved (AS) and non-autoclaved (NAS) soil from typical citrus orchards in the State of Sao Paulo, Southeastern region of Brazil. Various concentrations of conidia were incorporated into the soil the mortality, calculated based on the percentage of adult emergence, was 86% for the highest conidia concentrations: 2.52 x 1010 for AS and 2.52 x 1010 for NAS. The lethal concentration (LC50), expressed as conidia concentration, was 8.44 x 109 conidia/g of soil (S) for AS and 12.23 x 109 conidia/g of soil for NAS.

Dexamethasone action on caudal fin regeneration of carp Cyprinus carpio (Linnaeus, 1758)

Studies have demonstrated that the prolonged use of corticoids can delay the healing process, affecting re-epithelialization, neovascularization and collagen synthesis. As the fins of teleost fish contain a large amount of collagen, the aim of the present study was to investigate the effect of dexamethasone (anti-inflammatory and glucocorticoid steroid widely used in the treatment of rheumatic diseases) during the regeneration process in the caudal fin of specimens of carp (Cyprinus carpio). For such, two glass aquaria were used - one for a group of fish treated with dexamethasone (Henrifarma) in a 20 mg/L concentration and the other for the control group. The caudal fins were amputated transversally and fish remained in their respective aquaria until regeneration occurred. Samples of regenerating fins were collected on days 1, 2, 4, 6, 8 and 10 after amputation. The fins in the control group regenerated normally and grew within the expected in time course. The fins in the group treated with dexamethasone were significantly smaller in comparison to the control group at every evaluation time. Thus, it was possible to verify that, at this concentration of dexamethasone, the regeneration of the caudal fins was delayed, but not completely inhibited. The results show that the caudal fin is a good model for histological studies on regeneration and the action of drug toxicity, but its also of great importance the interaction with further studies for a better knowledge and understanding of all the changes in all the phases.Studies have demonstrated that the prolonged use of corticoids can delay the healing process, affecting re-epithelialization, neovascularization and collagen synthesis. As the fins of teleost fish contain a large amount of collagen, the aim of the present study was to investigate the effect of dexamethasone (anti-inflammatory and glucocorticoid steroid widely used in the treatment of rheumatic diseases) during the regeneration process in the caudal fin of specimens of carp (Cyprinus carpio). For such, two glass aquaria were used – one for a group of fish treated with dexamethasone (Henrifarma) in a 20 mg/L concentration and the other for the control group. The caudal fins were amputated transversally and fish remained in their respective aquaria until regeneration occurred. Samples of regenerating fins were collected on days 1, 2, 4, 6, 8 and 10 after amputation. The fins in the control group regenerated normally and grew within the expected in time course. The fins in the group treated with dexamethasone were significantly smaller in comparison to the control group at every evaluation time. Thus, it was possible to verify that, at this concentration of dexamethasone, the regeneration of the caudal fins was delayed, but not completely inhibited. The results show that the caudal fin is a good model for histological studies on regeneration and the action of drug toxicity, but it’s also of great importance the interaction with further studies for a better knowledge and understanding of all the changes in all the phases.

Phospholipid Containing Choline Histochemistry of Mouse Uterine Epithelia during Preimplantation Stage

The physiological role of high lipid content in endometrial cells during pregnancy has not been well established. In the present work we used histochemical techniques to analyze the total lipids and phospholipid containing choline (PCC) in the mouse uterine glandular and luminal epithelia during preimplantation stage. Sudan black histochemistry showed the highest intensity during the second day of pregnancy in both the basal and apical portions of luminal epithelium. Peaks of PCC staining were seen both in the luminal and glandular epithelia at the second and fifth days of pregnancy. Changes in localization and in the amount of lipid in the uterine epithelia suggest high mobility and metabolic rates of this substance, which may be related to morphological and/or functional changes occurring at the same time in the pregnant uterus. The increase and depletion timing of PCC content in the uterine epithelia during preimplantation stage, when uterine prostaglandin is also oscillating, suggest a possible involvement of PCC in prostaglandin biosynthesis. Therefore, the fate of lipid droplets found in the uterine epithelia may be related to critical changes of the pregnant endometrium, rather than the nourishment of developing embryos alone.

Basofilia e anisotropia nucleares em células de camundongo após tratamento com oxamniquine

Com o objetivo de se estudar a acao da oxamniquine, uma droga utilizada no tratamento da esquistossomose, sobre a cromatina de nucleos de celulas animais, foram estudados os padroes de basofilia e anisotropia nucleares em hepatocitos, em celulas do musculo cardiaco e em linfocitos de camundongos adultos jovens. A oxamniquine foi administrada por via oral (436 mg/kg) e preparados foram obtidos apos diversos tempos de fornecimento da droga aos animais. Nos nucleos corados com azul de toluidina a pH 4,0, apos digestao com RNAse, nao se encontrou diferenca quanto aos padroes de basofilia e anisotropia comparando-se animais tratados com controles. Demonstrou se assim que as moleculas de oxamniquine nao se alojam no interior da dupla helice do DNA, nao alteram a sua conformacao helicoidal nem se ligam aos grupos fosfatos livres desta macromolecula, diferindo, portanto, da atuacao de outro esquistossomicida, o hycanthone.

Nuclear basophilia and anisotropy in cells of mice treated with oxamniquine

Com o objetivo de se estudar a acao da oxamniquine, uma droga utilizada no tratamento da esquistossomose, sobre a cromatina de nucleos de celulas animais, foram estudados os padroes de basofilia e anisotropia nucleares em hepatocitos, em celulas do musculo cardiaco e em linfocitos de camundongos adultos jovens. A oxamniquine foi administrada por via oral (436 mg/kg) e preparados foram obtidos apos diversos tempos de fornecimento da droga aos animais. Nos nucleos corados com azul de toluidina a pH 4,0, apos digestao com RNAse, nao se encontrou diferenca quanto aos padroes de basofilia e anisotropia comparando-se animais tratados com controles. Demonstrou se assim que as moleculas de oxamniquine nao se alojam no interior da dupla helice do DNA, nao alteram a sua conformacao helicoidal nem se ligam aos grupos fosfatos livres desta macromolecula, diferindo, portanto, da atuacao de outro esquistossomicida, o hycanthone.