Enzymatic variability among venoms from different subspecies of Apis mellifera (Hymenoptera: Apidae)

The enzymatic variability was analyzed in venom extracts from bees reared in different colonies of the Africanized, A. m. ligustica and A. m. carnica subspecies. The implications of this variation focused on the biochemistry differentiation and immunogenicity of these venoms. The results showed the existence of a huge variability among the subspecies as well as among the colonies for three out of the six tested components - hyaluronidase, acid phosphatase and proteases - suggesting the utilization of these features as possible biochemical markers. Furthermore, although not statistically significant, it was found that the Africanized bee venom presented slightly higher levels of protein content and esterase activity, when compared to the other subspecies. If the esterase plays a role in the pain intensity caused by the sting, as suggested elsewhere, this might suggest a reason for a bigger algogenicity of this venom in relation to that of European bees. On the other hand, A. m. ligustica bees presented the highest levels of proteolytic and acid phosphatase activities, whose functions are not enlightened in Hymenoptera venoms. The A. m. carnica workers presented the highest hyaluronidase and the lowest acid phosphatase activity levels. The extremely variable results among colonies of the same subspecies and among subspecies, for the tested venom components, justify the absence of correlation between allergic reactions and tests with pooled venom.

Hydrolases in the hypopharyngeal glands of workers of Scaptotrigona postica and Apis mellifera (Hymenoptera, Apinae)

Hydrolytic enzymes from hypopharyngeal gland extracts of newly emerged, nurse and foraging workers of two eusocial bees, Scaptotrigona postica, a native Brazilian stingless bee, and the Africanized honey bee (Apis mellifera) in Brazil, were compared. The hypopharyngeal gland is rich in enzymes in both species. Fifteen different enzymes were found in the extracts, with only a few quantitative differences between the species. Some of the enzymes present in the extracts may have intracellular functions, while others seem to be digestive enzymes. Scaptotrigona postica, had lower β-glucosidase and higher lipase esterase activities than A. mellifera. The differences may be due to different feeding habits and behavioral peculiarities of the two species. ©FUNPEC-RP.

Morphological, cytochemical, and ultrastructural study of thrombocytes and leukocytes in neotropical fish, Brycon orbignyanus Valenciennes, 1850 (Characidae, Bryconinae)

Morphological, cytochemical and ultrastructural studies are important to demonstrate the function of the blood cells, which is very little understood in teleosts. In peripheral blood of piracanjuba' Brycon orbignyanus, thrombocytes, lymphocytes, monocytes, neutrophils and heterophils were studied and characterized. Thrombocytes had a fusiform or oval shape with PAS-positive granules. Lymphocytes presented small size with sparse basophilic cytoplasm. Monocytes were large in size, presented basophilic cytoplasm that may be foamy or vacuolated, with non-specific esterase staining. The neutrophils presented lightly neutrophilic granule cytoplasm, with positivity for PAS and peroxidase. The heterophils were large in size, with eosinophilic and basophilic granules cytoplasm and PAS-positive. Transmission electron microscopy study demonstrated that the thrombocytes, lymphocytes and monocytes features were similar to other teleosts. In ultrastructural study only one type of neutrophils was observed. Cytochemical findings indicated that neutrophils and monocytes of B. orbignyanus may be involved in phagocytosis, and neutrophils play an important microbicidal role.

Morphological and histochemical analysis of the human vestibular fold

A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.

New flavone from the leaves of Neea theifera (Nyctaginaceae)

Neea theifera Oerst. (Nyctaginaceae) is widely used in Brazilian folk medicine for the treatment of gastric ulcers and inflammation. Phytochemical investigation of the leaves of Neea theifera afforded the isolation of the new flavone luteolin-7-O-[2″-O-(5‴-O-feruloyl)-β-D-apiofuranosyl]- β-D-glucopyranoside (1) besides the eight-known compounds vitexin, isovitexin, isoorientin, orientin, vicenin-2, chrysoeriol, apigenin and luteolin. Their chemical identification was established by NMR spectroscopic methods including 2D-NMR, as well as UV and ESI-MS analyses. ©2007 Sociedade Brasileira de Química.

Compostos fenólicos e atividade antioxidante de Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae)

This paper describes a chemical investigation (by high-speed counter-current chromatography) of an extract in methanol of the capitula (flower-heads) of the endemic Brazilian herb Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae). Fractionation of this extract by preparative chromatography and identification of the isolated compounds by spectrometric methods (IR, UV, ESI-MS, NMR) led to the identification of flavones (apigenin, luteolin and 6-methoxyluteolin) and 1,3-di-O-feruloyl glycerol. The antioxidant activity of the extract was determined by DPPH reduction and the total phenolic content by the Folin-Ciocalteau assay. It was found that the methanolic extract of L. flavescens possesses strong antioxidant activity. Additionally, the chemical profile provided useful data for a discussion of the taxonomy of the Eriocaulaceae.

In vitro and in vivo inhibition of acetylcholinesterase and carboxylesterase by metals in zebrafish (Danio rerio)

Metals are natural components in ecosystems; however, if these elements are in excess, they can have adverse effects on living organisms. This study analyzes the interference of copper, lead, iron and cadmium in acetylcholinesterase (AChE) and carboxylesterase (CbE) activities in zebrafish. AChE was significantly inhibited in vitro by copper, iron, lead and cadmium at higher concentrations (10 and 20 mmol/L), whereas CbE was inhibited only at a concentration of 20 mmol/L. In vivo, only lead and cadmium were able to cause AChE inhibition at higher concentrations, while iron didn't cause any changes, and copper promoted an increase in AChE activity at a concentration of 0.06 mg/L. CbE activity did not change at any of the times (two and seven days) and concentrations tested, except in the case of copper exposure, which resulted in a decrease in CbE activity. Indeed, iodoacetamide treatment didn't changed AChE neither CbE activities, results which indicate that the metal inhibiting effect is probably not due to its biding to thiol groups close the active site of the enzyme. This outcome reveals that metals are important esterase inhibitors in zebrafish, and should be considered in environmental monitoring studies that use esterase inhibition as exposure biomarkers of organophosphate and carbamate pesticides. © 2012 Elsevier Ltd. All rights reserved.

Phenotypic and biochemical responses of sugarcane cultivars to glyphosate application

Sugarcane cultivars show varying degrees of herbicide susceptibility, with herbicide effects ranging from no injury to total plant eradication. In this study, phenotypic and biochemical responses to glyphosate were evaluated in three sugarcane cultivars. Herbicide tolerance of the three cultivars (IACSP93-3046, IACSP94-4004 and RB72454) was tested in a greenhouse experiment using a completely randomized design. The experiment consisted of four replications of treatments in a factorial arrangement of 3 cultivars × 6 glyphosate dosages (0, 1,440, 2,160, 2,880, 3,600 and 4,320 g a. e. ha-1). Intoxication symptoms, based on a percentage scale ranging from 0 (no injury) to 100 % (total plant death), and total chlorophyll content were recorded at 1, 2, 3, 6, 7, 10, 20 and 34 days after glyphosate application (DAA). Shikimate dehydrogenase and α-esterase isoenzyme assays were performed at 8, 24, 48, 72 and 144 h after application (HAA). Intoxication symptoms observed at 6 DAA ranged from 5 % at the lowest glyphosate dosage (1,440 g a. e. ha-1) to ~30 % at the highest dosage (4,320 g a. e. ha-1) across all cultivars. IACSP94-4004 and IACSP93-3046 were determined to be the most glyphosate-tolerant cultivars. Reduction in chlorophyll content was observed with high dosages of glyphosate at 6 DAA. The shikimate dehydrogenase banding pattern was generally conserved among cultivars and treatments, with the exception of the IACSP94-4004 cultivar, which showed alterations in the banding pattern of α-esterase after glyphosate application. © 2013 Society for Sugar Research & Promotion.

Conservação pós-colheita de atemóia cv. Thompson

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impacto da tecnologia de alta pressão hidrostática sobre a qualidade do suco de laranja

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da Hidroxiuréia, uma substância de uso médico, sobre parâmetros biológicos de Drosophila melanogaster

Pós-graduação em Genética - IBILCE

Efeito citotóxico do sistema HRP/Indóis em células McCoy in vitro

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

Biomarcadores bioquímicos de contaminação em girinos de anfíbios anuros expostos a Regent®800WG (Fipronil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação em biomarcadores bioquímicos de contaminação em Tilápias do Nilo (Oreochromis niloticus) de diferentes portes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo do efeito de metais em esterases de zebrafish (Danio rerio)

Pós-graduação em Química - IBILCE