Effects in short-term of alloxan application to diabetes induction in Wistar rats

The present study aimed to verify action of alloxan in metabolic and immune parameters after 24 and 192 hours of the injection in Wistar rats. Thus, eight rats were fasted and received monohidrated alloxan Sigma (32 mg/kg body weight) via endovenous. Glycemia and trglyceridemia analyzes were performed before and 192 hours after alloxan application. After 24 hours, alloxan application increased water intake and decreased body mass, food intake and leucocytes counting. 192 hours after alloxan application, there was a recuperation in food intake and leucocytes counting. On the other hand, in this period there was an increase of glycemia and water intake and reduction of body mass. These results indicate that some of diabetic signs caused by alloxan occur in short-term after drug administration.Univ Estadual Paulista, Dept Educ Fis, Sao Paulo, BrazilUniv Estadual Paulista, Dept Biol, Sao Paulo, BrazilUniv Fed Sao Paulo Baixada Santista, Sao Paulo, BrazilUniv Estadual Paulista, Dept Ciencias Biol, Sao Paulo, BrazilUniv Fed Sao Paulo Baixada Santista, Sao Paulo, BrazilWeb of Scienc

Efeitos do óleo da semente de neem (Azadirachta indica A. Juss) nos ovócitos e glândulas salivares de carrapatos Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Rhipicephalus sanguineus ticks have attracted, in recent years, the attention of researchers as well as public health managers, since they have become major urban pests, transmitters of diseases to humans and dogs. For this reason, the search for formulations with acaricide action has been constant concern of veterinary pharmaceutical industries. However, the vast majority of products currently commercialized exhibits high toxicity to the hosts of these ectoparasites and to the environment, even inducing resistance in ticks. Alternative control methods such as the use of plant extracts, for example, have become increasingly interesting, since they have reduced costs and low toxicity. In this sense, Azadirachta indica (neem) species stands out, as its leaf and seed extracts have recognized repellent, insecticide and acaricide potential. Thus, this study aimed to evaluate the morphological alterations resulting from the action of neem in the ovary and salivary glands of semi-engorged R. sanguineus female ticks, subjected to the topical application of the oil extracted from neem seeds, at concentrations of 20, 40 and 60%, using 10% aqueous ethanol as solvent. The organs were collected and fixed, and analyzed by means of techniques in conventional light microscopy, confocal laser scanning microscopy and transmission electron microscopy. In general, the methodology proposed in this work allowed the simulation of a topical treatment of the infested animals, making the results closer to a practical application in field. In both analyzed organs, neem oil clearly demonstrated a dose-dependent effect. Oocytes and glandular acini of R. sanguineus ticks exhibited similar morphological changes, such as evident signs of cytoplasmic disorganization, cellular vacuolation, nuclear or nucleolar irregularities, dilation of mitochondrial cristae, as well as dilation in rough endoplasmic reticulum lumen. These facts show that, regardless of the organ, neem ...Os carrapatos Rhipicephalus sanguineus têm atraído, nos últimos anos, a atenção de pesquisadores, bem como de órgãos gerenciadores da saúde pública, por estarem se tornando grandes pragas urbanas, transmissoras de doenças para cães e humanos. Por esta razão, a busca por formulações com ação acaricida tem sido preocupação constante das indústrias farmacêuticas veterinárias. No entanto, a grande maioria dos produtos atualmente comercializados apresenta alta toxicidade aos hospedeiros dos ectoparasitas e ao meio ambiente, induzindo, inclusive, resistência nos carrapatos. Métodos alternativos de controle, como o uso de extratos de plantas, por exemplo, têm se tornado cada vez mais interessantes, já que apresentam menores custos e baixa toxicidade. Neste sentido, destaca-se a espécie Azadirachta indica (neem), cujos extratos de folhas e sementes apresentam reconhecido potencial repelente, inseticida e acaricida. Desta forma, este estudo teve como objetivo avaliar as alterações morfológicas observadas no ovário e nas glândulas salivares de fêmeas semiingurgitadas de carrapatos R. sanguineus, submetidas à aplicação tópica do óleo extraído das sementes de neem, nas concentrações de 20, 40 e 60%, utilizando-se etanol aquoso a 10% como solvente. Os órgãos foram coletados, fixados, e analisados por meio de técnicas de microscopia de luz convencional, microscopia confocal de varredura a laser e microscopia eletrônica de transmissão. De forma geral, a metodologia proposta neste trabalho permitiu a simulação de um tratamento tópico dos animais infestados, tornando os resultados obtidos mais próximos de uma aplicação prática em campo. Em ambos os órgãos analisados, o óleo de neem demonstrou efeitos claramente dose-dependentes. Os ovócitos e os ácinos glandulares de carrapatos R. sanguineus exibiram alterações morfológicas semelhantes, tais como sinais evidentes de desorganização citoplasmática,...Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Collagen and reticular fibers in left ventricular muscle in diabetic rats: Physical exercise prevents its changes?

Diabetic cardiomyopathy contributes to the high incidence of mortality in both types of diabetes. We aimed to investigate the histochemical aspects of collagen and reticular fibers in the cardiac muscle and evaluate the influence of physical exercise on these aspects. Wistar rats were divided in 4 groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced with alloxan (35 mg/kg). Training program consisted of swimming 1 h/day with a load of 4.8% of body weight for TD and 5.2% for TC. during 8 weeks. At the end of the experiment, samples of the left ventricle were collected, fixed in Bouin and processed on historesin. Sections were stained with periodic acid of Schiff, picrosirius-hematoxylin and ammoniacal silver. the PAS technique shows that individuals of group SD presented more intense reaction that the other groups. Picrosirius-hematoxylin technique showed a possible deposition of collagen fibers in SD. the TD group presented a reaction a lot similar to the controls' for both techniques', showing a possible prevention of this deposition. These results indicate that physical exercises might have an important role on the prevention of some negative alterations caused by experimental diabetes. (C) 2010 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)São Paulo State Univ, Dept Biol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, São Paulo, BrazilWeb of Scienc

Tests of fed and unfed Amblyomma cajennense ticks (Acari: Ixodidae): first morphological data

The tick species Amblyomma cajennense is of great medical importance, as it is the vector of the Rickettsia rickettsii, agent of Rocky Mountain spotted fever. The objective of this study was to perform a morphological and histological analysis of the male reproductive system of fed and unfed A.cajennense. The male reproductive system is formed by a pair of tubular testes dorsolaterally arranged in opisthosoma. They were divided into three regions: proximal region (next to vas deferens), median region and distal region (nearest to the blind ending of testis). Proximal regions are connected to the seminal vesicles by the deferent ducts and to accessory glands, similar to what was observed for other Ixodidae. Feeding plays a fundamental role in the development of the reproductive system, as in unfed individuals, the testes, the seminal vesicles and the accessory glands were smaller comparing with the fed individuals. In addition, the prospermia, precursors of the spermatozoa, were only observed in fed individuals. The germ cells were organized in spermatocysts, enveloped by a connective tissue. The cells in more advanced stages of spermatogenesis were localized in the distal region, in accord with studies in other ticks, but opposite to what was observed for other arthropods.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

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Effects of andiroba (Carapa guianensis) oil in ticks: ultrastructural analysis of the synganglion of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

The present study performed an analysis of the ultrastructural changes induced by andiroba seed oil in the synganglion of Rhipicephalus sanguineus female ticks, aiming to provide scientific grounds to help in the creation of more specific and efficient methods of control. The synganglion consists of a mass of fused nerves externally covered by the neural lamella, a uniform and acellular layer. Just below, the perineurium is found, formed by glial cells. Internally, the synganglion is subdivided into an outer cortical region (cortex), which contains the cellular bodies of the neural cells and an inner region, the neuropile, formed by a set of nerve fibers (extensions of the neural cells). The results showed that the synganglion of females exposed to andiroba oil showed structural changes, such as: irregular and apparently thinner neural lamella, perineurium glial cells presenting large cytoplasmic vacuoles, decrease in the extensions of glial cells, separation of cortex cells, which were formerly attached through their membranes, neural cells presenting irregular plasma membranes and cytoplasm with autophagic vacuoles and mitochondria with disorganized cristae and in process of degeneration. This study confirmed the neurotoxic action of the andiroba oil, which would probably be able to impair the neural functions. Thus, it is suggested that this product has the potential to be used as an alternative method to control ticks.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Central nervous system of Rhipicephalus sanguineus ticks (Acari: Ixodidae): an ultrastructural study

This study performed the ultrastructural description of the synganglion of Rhipicephalus sanguineus males and females, aiming to contribute to the understanding of the cellular organization of this organ. The results show that the central nervous system of these individuals consists of a mass of fused nerves, named synganglion, from where nerves emerge towards several parts of the body. It is surrounded by the neural lamella, a uniform and acellular layer, constituted by repeated layers of homogeneous and finely granular material. The perineurium is just below, composed of glial cells, which extensions invaginate throughout the nervous tissue. The synganglion is internally divided into an outer cortex, which contains the cellular bodies of the neural cells and an inner neuropile. The neural cells can be classified into two types according to cell size, cytoplasm-nucleus relation, and neurosecretory activity. Type I cells are oval or spherical and present a large nucleus occupying most part of the cytoplasm, which contains few organelles. Type 2 cells are polygonal, present a great cytoplasm volume, and their nuclei are located in the cell periphery. The cytoplasm of these cells contains a well-developed rough endoplasmic reticulum, Golgi regions, mitochondria, and several neurosecretory granules. The subperineurium and the tracheal ramifications are found between the cortex and the neuropile. The latter is formed mainly by neural fibers, tracheal elements, and glial cells. The results obtained show that R. sanguineus males' and females' nervous tissue present an ultrastructural organization similar to the one described in the literature for other tick species.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP [2010/51942-8, 2011/06865-8, 2011/10427-6

Potential of the chemical dinotefuran in the control of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) semi-engorged female ticks

Ticks are vectors of several pathogens to vertebrates, including the human being. They produce lesions on the hosts during the blood feeding and great economic losses. Several chemical acaricides have been used in an attempt to control tick infestations; however these substances are harmful to both the human being and non-target organisms, and to the environment. Therefore, there is a need to fight these ecto-parasites through less harmful methods, less aggressive to the environment, non-target organisms and to the human health. The present study examined the efficacy of dinotefuran on the susceptibility of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of the product. Its lethal concentration of 50% (LC50) at 95% confidence interval was determined. The ticks were immersed in Petri dishes containing different concentrations of dinotefuran or distilled water for 5 minutes and then dried and maintained in an incubator for 7 days. The results showed the daily number of dead R. sanguineus semi-engorged females after being treated with different concentrations of dinotefuran. The mortality data in bioassay 2 were subjected to Probit analysis, where a LC50 of 10,182.253 ppm (8725.987-13,440.084) and 95% confidence interval were estimated. The susceptibility of R. sanguineus semi-engorged females to dinotefuran in higher concentrations of the acaricide was demonstrated, indicating that its effect is probably dose-dependent. In addition, the action of dinotefuran was slow and gradual, interfering in the development and growth of the individuals throughout the observation period (7 days). (C) 2015 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq