Publications by authors named "Ronaldo Zucatelli Mendonca"

Brazil has a very large biological variety, which is an almost inexhaustible source of substances of pharmacological and biotechnological interest. Several studies have demonstrated the presence of bioactive peptides in insect hemolymph and their potential use as therapeutic agents. However, few data are available regarding molecules extracted from insects with anti-apoptotic action.

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Snake venom contains a variety of toxins with a range of biological activity, among these toxins cysteine-rich secreted proteins (CRISPs) can be found. The proteins of this family have masses of 20-30 kDa and display homologous amino acid sequences containing 16 cysteine residues, forming eight disulfide bonds. Some of these proteins have been explored, characterized, and described in terms of their activity; however, little is known about their range of activities.

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The antitumor properties of ticks salivary gland extracts or recombinant proteins have been reported recently, but little is known about the antitumor properties of the secreted components of saliva. The goal of this study was to investigate the in vitro effect of the saliva of the hard tick Amblyomma sculptum on neuroblastoma cell lines. SK-N-SK, SH-SY5Y, Be(2)-M17, IMR-32, and CHLA-20 cells were susceptible to saliva, with 80% reduction in their viability compared to untreated controls, as demonstrated by the methylene blue assay.

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Neovascularization, a process that includes vasculogenesis and angiogenesis, may be a physiological or pathologic event, but in any cases the phenomenon is related to the formation of vascular net and sprouting of endothelial cells from preexisting blood vessel. The tumor environment, which counts on the tumor cell proliferation, is plenty of proangiogenic factors, such as angiogenin, TGF (α and β), FGF, VEGF, all of them playing a crucial role in angiogenesis, an important hallmark of cancer frequently related to a poor prognosis. Therefore, therapies focusing the inhibition of cancer neovasculogenesis have become an interesting strategy for the development of antitumor therapies.

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Influenza viruses cause worldwide outbreaks and pandemics in humans and animals every year with considerable morbidity and mortality. The molecular diversity of secondary metabolites extracted from mollusks is a good alternative for the discovery of novel bioactive compounds with unique structures and diverse biological activities. Phyllocaulis boraceiensis is a hermaphroditic slug that exudes mucus, in which was detected hydroxy polyunsaturated fatty acids that exhibited potent antiviral activity against measles virus.

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Ornithodoros mimon is an argasid tick that parasitizes bats, birds and opossums and is also harmful to humans. Knowledge of the transcripts present in the tick gut helps in understanding the role of vital molecules in the digestion process and parasite-host relationship, while also providing information about the evolution of arthropod hematophagy. Thus, the present study aimed to know and ascertain the main molecules expressed in the gut of argasid after their blood meal, through analysis on the gut transcriptome of engorged females of O.

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Measles is a viral disease highly contagious spread by respiratory transmission. Although infection can be controlled by vaccination, numerous cases of measles have been registered in many areas of the world, highlighting the need for additional interventions. Terrestrial gastropods exude mucus on their body surface when traveling, to protect the body from mechanical injury, desiccation or contact with harmful substances.

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The studies on chemical composition and biological activity of propolis had focused mainly on species Apis mellifera L. (Hymenoptera: Apidae). There are few studies about the uncommon propolis collected by stingless bees of the Meliponini tribe known as geopropolis.

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The transient transfection process has been developed to allow rapid production of recombinant proteins. In this paper, we describe the transient expression of recombinant rabies virus glycoprotein (RVGP) in Drosophila melanogaster Schneider 2 (S2) cells. Different cell transfection reagents were evaluated, together with the effects of different cell cultivation procedures on RVGP expression.

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This study presents a new recombinant protein that acts as a powerful antiviral (rAVLO-recombinant Antiviral protein of Lonomia obliqua). It was able to reduce the replication by 10(6) fold for herpes virus and by 10(4) fold for rubella virus. RT-PCR of viral RNA rAVLO treated infected cells also showed similar rate of inhibition in replication.

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Many active principles produced by animals, plants and microorganisms have been employed in the development of new drugs for the treatment of human diseases. Among animals known to produce pharmacologically active molecules that interfere in human cell physiology, the caterpillar Lonomia obliqua has become the focus of toxicological studies due to recent findings about its venom constituents. The objective of this study was to investigate the effects of L.

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The control of viral infections, especially those caused by influenza viruses, is of great interest in Public Health. Bio prospection has shown the presence of active principles in the hemolymph of arthropods, and in the salivary gland of ticks, and some of these are of interest for the development of new pharmacological drugs. Ticks lay their eggs in the environment, and to protect them from desiccation and microbial attack they involve the eggs in a waxy layer produced by an organ known as Gené's Organ.

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This study evaluated the effects of a micro cycle of overload training (1st-8th day) on metabolic and hormonal responses in male runners with or without carbohydrate supplementation and investigated the cumulative effects of this period on a session of intermittent high-intensity running and maximum-performance-test (9th day). The participants were 24 male runners divided into two groups, receiving 61% of their energy intake as CHO (carbohydrate-group) and 54% in the control-group (CON). The testosterone was higher for the CHO than the CON group after the overload training (694.

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In this study, we have described the biological activity of various hydrolysates and its effect on cell growth, growth rate and doubling time. A potent cell culture enhancer factor was observed in the yeastolate hydrolysates, mainly in the protein fractions with low molecular weight. In this case, a growth enhancer of 60.

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Trypsin is required in the hemagglutinin (HA) cleavage to in vitro influenza viruses activation. This HA cleavage is necessary for virus cell entry by receptor-mediated endocytosis. Bacteria in the respiratory tract are potential sources of proteases that could contribute to the cleavage of influenza virus in vivo.

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