Comparative morphology of the endocrine brain and retrocerebral complex of the honeybee worlker and queens (Hymenoptera-apinae)

Foi estudado o aspecto das células neurosecretoras da pars intercerebralis e dos corpora cardiaca e allata, em material obtido de rainhas e operárias de Apis mellifera em diferentes idades. O material foi corado com hematoxilina crômicafloxina, verificando-se urna degranulação das células neurosecretoras das operárias após os 15 dias de ida de com correspondente aumento da atividade dos corpora cardiaca e dos corpora allata.Nas rainhas, com exceção da rainha virgem e da rainha fecundada, com 3 anos de idade, a atividade desse sistema endocrino manteve-se constante, fato que parece indicar a atuação dos hormônios produzidos na vitelogênese

Ultrastructure of ovarian follicular epithelium of the amazonian fish Pseudotylosurus microps (Gunther) (Teleostei, Belonidae): I. the follicular cells cycle of development

The present paper deals with the changes on ultrastructural features of the follicular cells along the growth of the oocyte of Pseudotylosurus microps (Gunther, 1868). The epithelium pass from single squamous to pseudostratified and finally cylindric. Remarkable are the changes in the nuclear shapes, the increasing amount of rough endoplasmic reticulum and the formation of large lipid deposits in the follicular cells by the end of vitellogenic phase. Very peculiar intercellular deposits forms between the perinucleolar and vitellogenic phase of oocyte maturation. Although largely referred to in the specialized literature, our attempts to correlate the follicular cells changes with the formation of the oocyte envelopes or even with an endocrine function are not supported by conclusive evidences in the present paper.99109Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Morphological study of the spermatogenesis in the teleost Piaractus mesopotamicus

The spermatogenesis of Piaractus mesopotamicus was investigated under light and transmission electron microscopy. The specimens were captured from their natural environment (Rio Miranda and Rio Aquidauana, Pantanal Matogrossense, Brazil) during April and September. The results were compared with the spermatogenic data of specimens under captivity condition. In both conditions, P mesopotamicus presented the typical spermatogenesis pattern of the teleost fishes, showing no significative differences. The spermatozoon was classified as type 1, which has a globular head without acrosome, a short middle piece and a long tail constituted only by the flagellum. This type of spermatozoon is considered the basic type in fishes.27331932

Characterization Of The Crotalus Durissus Terrificus Venom By Atomic Force Microscopy

A preliminary analysis of the morphology of crude CDT venom was performed using atomic force microscopy (AFM). As a result, a direct measurement of the forces between the surface of the venom crystals and a sharp probe tip was achieved.20413171321Azevedo Marques, M.M., Cupo, P., Coimbra, T.M., Hering, S.E., Rossi, M.A., Laure, C.J., (1985) Toxicon, 23, p. 631Sanchez, E.E., Soliz, L.A., Susana Ramirez, M., Perez, J.C., (2001) Toxicon, 39, p. 523Soares, A.M., Mancin, A.C., Cecchini, A.L., Arantes, E.C., Franca, S.C., Gutierrez, J.M., Giglio, J.R., (2001) Int. J. Biochem. Cell Biol., 33, p. 877Choumet, V., Lafaye, P., Demangel, C., Bon, C., Mazie, J.C., (1999) Biol. Chem., 380, p. 561Sanchez, S.A., Chen, Y., Muller, J.D., Gratton, E., Hazlett, T.L., (2001) Biochemistry, 40, p. 6903Sharma, S., Jabeen, T., Singh, J.K., Bredhorst, R., Vogel, C.W., Betzel, C., Singh, T.P., (2001) Acta Crystallogr., Sect. D: Biol. Crystallogr., 57, p. 596Nonato, M.C., Garrat, R.C., Mascarenhas, Y.P., Jesus, W.D.P., Assakura, M.T., Serrano, S.M.T., Oliva, G., (2001) Biol. Crystallogr., D, 57, p. 599Arni, R.K., Ward, R.J., (1996) Toxicon, 34, p. 827Souza, D.H.F., Selistre-deAraujo, H.S., Garratt, R.C., (2000) Toxicon, 38, p. 1307Binning, G., Coate, C.F., Gerber, G., (1986) Phys. Rev. Lett., 56, p. 930Baranauskas, V., Vidal, B.C., Parizotto, N.A., (1998) Appl. Biochem. Biotechnol., 69, p. 91Baranauskas, V., Garavello-Freitas, I., Jingguo, Z., Cruz-Hofling, M.A., (2001) J. Vac. Sci. Technol. A, 19, p. 104

Effects of manganese (Mn2+) on neurotoxic and myotoxic activities induced by Crotalus durissus terrificus and Bothrops jararacussu venoms in chick biventer cervicis preparations

In the present study, manganese (Mn2+), a neuromuscular blocker with pre and postsynaptic actions, was used to verify the neurotoxicity and myotoxicity induced by Crotalus durissus terrificus (Cdt) and Bothrops jararacussu (Bjssu) venoms in biventer cervicis preparations (BCp). Preparations pretreated with 0.66 and 1.6mM Mn2+ did not affect Cdt venom-induced blockage nor change KCl-induced contracture but partially reduced ACh-induced contracture. However, both Mn2+ concentrations partially hindered Bjssu venom-induced blockage after washing the preparations with Krebs solution, and only 1.6mM Mn2+ preparations significantly recovered ACh-induced contracture. The effect of Cdt venom myotoxicity on contractile responses was different from that of Bjssu venom myotoxicity. Pretreatment with 1.6mM Mn2+ partially reduced muscle damage percentage and creatine kinase (CK) activity (U/l) induced by both venoms. In conclusion, Mn2+ interfered in ACh-induced contracture of the nicotinic receptor; did not prevent Cdt venom neurotoxicity but partially reduced its myotoxicity in vitro due to the stabilizing action of this venom on the sarcolemmal membrane; and partially attenuated myotoxicity and neuromuscular blockage induced by Bjssu venom. The Mn2+ dual action (pre and postsynaptic) is useful to study snake venoms since most of them present one or both of these actions; besides, Mn2+ allowed recovering coherent interpretation of experimental versus clinical results.13247949

Expression Of Vegf And Flk-1 And Flt-1 Receptors During Blood-brain Barrier (bbb) Impairment Following Phoneutria Nigriventer Spider Venom Exposure

Apart from its angiogenic and vascular permeation activity, the vascular endothelial growth factor (VEGF) has been also reported as a potent neuronal protector. Newborn rats with low VEGF levels develop neuron degeneration, while high levels induce protective mechanisms in several neuropathological conditions. Phoneutria nigriventer spider venom (PNV) disrupts the blood-brain barrier (BBB) and causes neuroinflammation in central neurons along with excitotoxic signals in rats and humans. All these changes are transient. Herein, we examined the expression of VEGF and its receptors, Flt-1 and Flk-1 in the hippocampal neurons following envenomation by PNV. Adult and neonatal rats were evaluated at time limits of 2, 5 and 24 h. Additionally, BBB integrity was assessed by measuring the expression of occludin, β-catenin and laminin and neuron viability was evaluated by NeuN expression. VEGF, Flt-1 and Flk-1 levels increased in PNV-administered rats, concurrently with respective mRNAs. Flt-1 and Flk-1 immunolabeling was nuclear in neurons of hippocampal regions, instead of the VEGF membrane-bound typical location. These changes occurred simultaneously with the transient decreases in BBB-associated proteins and NeuN positivity. Adult rats showed more prominent expressional increases of the VEGF/Flt-1/Flk-1 system and earlier recovery of BBB-related proteins than neonates. We conclude that the reactive expressional changes seen here suggest that VEGF and receptors could have a role in the excitotoxic mechanism of PNV and that such role would be less efficient in neonate rats. © 2013 by the authors; licensee MDPI, Basel, Switzerland.51225722588Vassilevsky, A.A., Koslov, S.A., Egorov, T.A., Grishin, E.V., Purification and characterization of biologically active peptides from spider venoms (2010) Methods Mol. 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In Vitro Antiophidian Properties of Dipteryx alata Vogel Bark Extracts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 mu g/mL) and Crotalus durissus terrificus (Cdt, 15 mu g/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited similar to 40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.15959565970Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)PROBIC/UNISOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [Proc. FAPESP 04/09705-8, 07/53883-6]FAPESP [07/51414-9, 08/05459-3]CNPq [Proc. 302206/2008-6

A comparison of in vitro methods for assessing the potency of therapeutic antisera against the venom of the coral snake Micrurus nigrocinctus

Therapeutic antisera against Micrurus nigrocinctus venom were tested for protection against lethality, as well as for inhibition of the nicotinic acetylcholine receptor (AchR)-binding and neutralization of phospholipase A2 (PLA2) activities of the homologous venom. Protection against venom lethality did not correlate with inhibition of AchR-binding activity, whereas there was a significant correlation between antisera potency and inhibition of PLA2 activity (r = 0.82, n = 10, P < 0.02). Inhibition of PLA2 activity could be useful in assessing the protective efficacy of M. nigrocinctus antisera during antivenom production. Micrurus nigrocinctus nigrocinctus venom proteins were fractionated by cation-exchange chromatography on Mono S FPLC and fractions assayed for lethality, AchR-binding and PLA2 activities. Antisera were titrated by enzyme-linked immunoassay (ELISA) against a crude M. n. nigrocinctus venom, two FPLC lethal fractions containing AchR-binding activity, and two toxins purified from M. n. nigrocinctus venom. No correlation was found between protective efficacy and the ELISA titer against any of these antigens. Compared to other elapid venoms that contain few toxins as major components, M. n. nigrocinctus venom appears to be more complex and its lethal effect is likely to be due to the combined effect of several neurotoxins.Universidad de Costa Rica/[74l-93-301]/UCR/Costa RicaInternational Foundation for Science/[F/0883-4]/IFS/SueciaSwedish Agency for Research Cooperation with Developing Countries//SAREC/SueciaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Caracterização das mutações no gene KatG de cepas de mycobacterium tuberculosis resistentes a isoniazida

Orientador: Marcelo de Carvalho RamosTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: Isoniazida, rifampicina e pirazinamida têm sido usadas como a base do tratamento da tuberculose no Brasil e na maioria dos países do mundo. O fenômeno da resistência bacteriana aos agentes quimioterápicos tem sido descrito desde que seu uso foi instituído. No caso da tuberculose, houve aumento expressivo do número de cepas resistentes, principalmente na década de 1990, devido à desestruturação dos serviços de vigilância e controle da doença e, também, à pandemia da AIDS. A resistência a antimicrobianos em cepas de Mycobacterium tuberculosis resulta em aumento da morbi-mortalidade e maiores custos para o serviço de saúde. A mutação no códon 315 do gene katG, responsável pela codificação da enzima catalase-peroxidase em M. tuberculosis, é um dos mecanismos de resistência desta bactéria à isoniazida. Para caracterizar as bases genéticas da resistência a drogas em cepas de M. tuberculosis no estado de São Paulo, foram selecionadas para estudo 91 amostras resistentes e 4 sensíveis à isoniazida. Essas cepas foram obtidas de culturas enviadas ao Instituto Adolfo Lutz central, em São Paulo, para identificação e realização de teste de sensibilidade a drogas. Um total de 467 cepas foram recebidas no período de agosto de 1999 a setembro de 2000. A genotipagem, utilizando a técnica de RFLP, foi realizada para o estabelecimento de parentesco entre as cepas. Estudos com as técnicas de SSCP e seqüenciamento de fragmento contendo o códon 315, amplificado do gene katG, foram realizados para triagem e confirmação de mutações associadas à resistência à isoniazida. A associação de resistência à isoniazida e rifampicina foi encontrada em 74.8% das cepas testadas. Resistência à isoniazidalpirazinamida e isoniazidaletambutol foi encontrada em 33 e 9,9%, respectivamente. Resistência concomitante a todas as drogas consideradas de primeira linha para o tratamento da tuberculose (isoniazida, rifampicina e pirazinamida) foi encontrada em 13,1 % das cepas. A genotipagem mostrou padrão heterogêneo de bandas, com formação de oito agrupamentos com apenas dua~ amostras cada. A substituição AGC~ACC (Serina~Tirosina) foi a mutação mais encontrada (48%). Não foram encontradas mutações em 39,5% das cepas resistentes estudadas e nos restantes 12,5% foram detectadas outras mutações. Conclui-se que no estado de São Paulo a resistência à rifampicina é freqüente entre as cepas resistentes à isoniazida. A resistência às três principais drogas para o tratamento da tuberculose também ocorreu em alta freqüência. A substituição AGC-.ACC foi a mutação mais encontrada, porém uma grande parte das cepas resistentes não apresentavam tais mutações. Pelos dados levantados, podemos também inferir que o fenômeno da resistência do M. tuberculosis a drogas não é, em São Paulo, uma conseqüência de disseminação clonal das cepas, mas casos isolados, provavelmente secundários a irregularidades no tratamento. Este trabalho, quando do seu início, foi um dos primeiros a endereçar a questão das bases genéticas para resistência a drogas em M. tuberculosis no Brasil, e estudos mais sistemáticos e abrangentes são necessários para melhor compreensão desta dinâmica em nosso meioAbstract: Isoniazid, rifampin and pirazinamide have been used as the Standard treatment for tuberculosis in Brazil and most countries around the world. Antimicrobial resistance has been described since its use was instituted. As for tuberculosis, there has been an expressive rise in multidrug resistant strains in the decade of 1990, due mainly to the dismantling of tuberculosis vigilance programs and the AIDS pandemics. Antimicrobial resistance among Mycobacterium tuberculosis strains result in increase in morbidity and mortality and cost for health care. Mutations in codon 315 of the katG gene, responsible for coding catalaseperoxidase in M tuberculosis. has been associated as one of the key mechanisms of resistance of this bacteria to isoniazid. In Brazil, studies towards the molecular mechanisms involved in this process are still on its beginning. To characterize the genetic basis of M tuberculosis drug resistance in the state of São Paulo, 91 isoniazid resistant and 4 isoniazid sensitive strains were selected for study. These strains were drawn from samples (462 strains) sent to the Instituto Adolfo Lutz central laboratory in São Paulo for identification and drug susceptibility tests. The study period was from august 1999 through september 2000. Genotyping of mycobacterium was performed using RFLP technique. SSCP study and sequencing of the amplified fragment of katG gene that contained codon 315 were performed to screen and check for mutations conferring resistance to isoniazid. Concomitant resistance to isoniazid and rifampin was foud in 74,8% of strains tested. Resistance to both isoniazid/rifampin and isoniazid/ethambutol was found in 33 and 9,9%, respectively. Concomitant resistance to all drugs considered as first line treatment of tuberculosis (isoniazid, rifampin and pirazinamid) was found in 23,1% of strains. Genotypic studies revealed a heterogeneous band pattern, with formation of 8 clusters with only two specimens each. The most prevalent substitution was AGC-+ACC (Ser-+Thr), found in 48% of strains. No mutation was noted in 39,5% of resistant strains studied, and the remaining 12,5% habored other I .5S frequent mutations. In conclusion, resistance to rifampin is a frequent event among isoniazid resistant strains collected in Sao Paulo, Brazil. Resistance to the three front drugs used for the treatment of tuberculosis also occurred in high frequency. The AGC-+ACC substitution was the most frequent mutation found, a1thougha high percentage of strains did not carry any mutationDoutoradoClinica MedicaDoutor em Clínica Médic