Gervásio Henrique Bechara

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The present study performed an analysis about the effects of andiroba seed oil (Carapa guianensis) in the ovary of Rhipicephalus sanguineus semi-engorged females; once, there are few studies about the action of natural products on the reproductive system, a vital organ for the biological success of this animal group. The results showed that andiroba oil is(More)
The present study demonstrated the effects of the arthropod growth regulator, fluazuron (Acatak®), in the formation of the integument and digestive processes of Rhipicephalus sanguineus nymphs fed on rabbits treated with different doses of this chemical acaricide. For this, three different doses of fluazuron (20, 40, or 80 mg/kg) were applied “pour on” to(More)
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(More)
The tick Rhipicephalus sanguineus is the species with the largest worldwide distribution and is proven to be involved in the transmission of pathogens such as Babesia canis, Ehrlichia canis, Coxiella burnetii, Rickettsia ricketsii, Rickettsia conorii, among others. Studies have demonstrated acquisition of resistance to some of the active principles used in(More)
This study analyzed the histopathology of rabbit skin, previously immunized with SGE2, SGE4, and SGE6 gland extracts prepared from salivary glands of Rhipicephalus sanguineus female with 2, 4, and 6 days of feeding, at the region of the R. sanguineus female feeding lesion 2, 4, and 6 days after tick attachment. In this work, infestation-naïve New Zealand(More)
Cocaine cardiotoxicity is partly due to sympathetic activation of the heart resulting from inhibition of catecholamine uptake at the sympathetic nerve terminal and possible central sympathetic stimulation and/or inhibition. This study evaluated the role of postsynaptic mechanisms in potentiation by cocaine of cardiac adrenergic responses. Cardiovascular(More)
In ticks, the digestion of blood occurs intracellularly and proteolytic digestion of hemoglobin takes place in a dedicated type of lysosome, the digest vesicle, followed by transfer of the heme moiety of hemoglobin to a specialized organelle that accumulates large heme aggregates, called hemosomes. In the present work, we studied the uptake of fluorescent(More)
The present study demonstrated the effects of dinotefuran (active compound of the Protetor Pet® acaricide) in germ cells and the digestive processes of semi-engorged females of R. sanguineus exposed to different concentrations of the chemical. For this purpose, 120 semi-engorged females were divided into four treatment groups with 30 individuals each: group(More)
Comparative studies between brown dog tick Rhipicephalus sanguineus populations from Brazil (Jaboticabal, São Paulo) and Argentina (Rafaela, Santa Fé) showed significant biological, morphological and genetic differences between them. This work aimed to study, in a comparative way, the acquisition of resistance in domestic dogs to R. sanguineus from(More)
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(More)