270 research outputs found
Mechanisms of Vascular Damage by Hemorrhagic Snake Venom Metalloproteinases: Tissue Distribution and In Situ Hydrolysis
Snakebite accidents by vipers cause a massive disturbance in hemostasis and tissue damage at the snakebite area. The systemic effects are often prevented by antivenom therapy. However, the local symptoms are not neutralized by antivenoms and are related to the temporary or permanent disability observed in many patients. Although the mechanisms involved in coagulation or necrotic disturbances induced by snake venoms are well known, the disruption of capillary vessels by SVMPs leading to hemorrhage and consequent local tissue damage is not fully understood. In our study, we reveal the mechanisms involved in hemorrhage induced by SVMPs by comparing the action of high and low hemorrhagic toxins isolated from Bothrops venoms, in mouse skin. We show remarkable differences in the tissue distribution and hydrolysis of collagen within the hemorrhagic lesions induced by high and low hemorrhagic metalloproteinases. According to our data, tissue accumulation of hemorrhagic toxins near blood vessel walls allowing the hydrolysis of basement membrane components, preferably collagen IV. These observations unveil new mechanistic insights supporting the local administration of metalloproteinases inhibitors as an alternative to improve snakebite treatment besides antivenom therapy
Detection of biogenic amines in mead of social bee
Mead is an alcoholic beverage, resulting from the fermentation of honey and water, although it is an old drink,
some fermentation products are still unknown. Biogenic amines have driven research on food and beverages due
to their toxicity and capacity to cause damage to the human health. This study aimed to evaluate the presence of
biogenic amines in mead from honey of two species of social bees, using different fining agents (bentonite,
banana peel flour, and passion fruit peel flour) and storage in oak barrel for 120 days. We observed the presence
of three biogenic amines for each type of mead. Putrescine was reported only in samples of mead of Apis mellifera.
Tryptamine and histamine were not detected, while tyramine was observed in the mead samples of honey
from Melipona quadrifasciata anthidioides. Samples clarified with fruit peels increased the number of amines. In
the analysis of the histamine, used as standard, obtained limits of detection and quantification of 2.47 mg/L and
of 7.48 mg/L, respectively. In this study, the amines observed remained below the limit of detection, and did not
pose a risk to consumers. The finings used demonstrated a profile similar to the control mead, and its use was
satisfactory.We thank the National Council of Technological and Scientific Development (Conselho Nacional de Desenvolvimento Científico e
Tecnológico - CNPq) under Grant (305885/2017 to C.A.L.C.). This
study was financed in part by the Coordenação de Aperfeiçoamento de
Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001. We also
thank the Fundação de Amparo a Pesquisa do Estado da Bahia -
FAPESB, under Grant 8797/2015.info:eu-repo/semantics/publishedVersio
Antioxidants activity and physicochemical properties of honey from social bees of the Brazilian semiarid region
This study compared the nutraceutical potential of Apis mellifera and Melipona quadrifasciata anthidioides honeys from the semiarid region of Bahia, Brazil, using microbiological, melissopalynological, and physicochemical techniques. Total phenols and flavonoids and the antioxidant activity were also determined. All samples had good microbiological quality and safety with an absence of coliforms, Escherichia coli, Salmonella spp., Staphylococcus coagulase positive and Clostridium sulphite reducing spores. Were identified 41 pollen types belonging to 23 botanical families. Myrtaceae, Anacardiaceae, and Sapindaceae were the predominant pollen types in A. mellifera honey, while honey Malvaceae was the most representative in the M. q. anthidioides. Regarding the physicochemical parameters evaluated, 75% complied with the standards established by the Brazilian and European quality legislation. The honey samples of A. mellifera had higher values of phenolic compounds and flavonoids (260.0 to 341.51 mgGAE.kg−1 and from 114.44 to 216.29 mgQE.kg−1, respectively). The samples from M. q. anthidioides presented higher antioxidant activity. The honeys of A. mellifera and M. q. anthidioides from the semiarid regions presented distinct botanical compositions, suggesting that both species use different plant sources, which possibly influenced the parameters related to honey quality as well as the content of phenolic compounds.We thank the National Council of Technological and Scientific
Development (Conselho Nacional de Desenvolvimento
Científico e Tecnológico - CNPq) under Grant (305885/2017
to C.A.L.C.). This study was financed in part by the
Coordenação de Aperfeiçoamento de Pessoal de Nível
Superior - Brasil (CAPES) - Finance Code 001. We also thank
the State of Bahia Research Foundation (Fundação de Amparo
a Pesquisa do Estado da Bahia - FAPESB) under Grant
8797/2015.info:eu-repo/semantics/publishedVersio
Xylem water potentials of native shrubs from northeastern Mexico
Xylem water potentials (C) were evaluated in browse plants such as Forestiera angustifolia (Oleaceae), Celtis pallida (Ulmaceae), Zanthoxylum fagara (Rutaceae), and Eysenhardtia texana (Fabaceae). Collections were carried out at Linares County, a semi-arid region of northeastern Mexico. C (MPa) were estimated at 10-day intervals between July 10 and September 30, 2008 by using a Scholander pressure bomb, and were monitored in five different plants per species at 06:00 h (predawn) and 14:00 h (midday). Air temperature, relative humidity, precipitation, and soil water content were registered
throughout. Data were subjected to one-way ANOVA and linear correlation analysis. At the wettest period, C at predawn varied from 0.29 (C. pallida and E. texana) to 0.37 (F. angustifolia and Z. fagara); in contrast, at the driest period, predawn C ranged from 3.28 (F. angustifolia) to 4.50 (Z. fagara). At midday E. texana achieved the highest (1.14) and lowest (4.20) values at wettest and driest sampling dates, respectively. It seems that air temperature and vapor pressure deficit negatively influenced C values in all species; conversely, C values augmented as relative humidity increased. Since F. angustifolia and C. pallida maintained higher predawn and midday C values under water stress, these species may be considered as drought-adapted species while, Z. fagara and E. texana that acquired lower values, may be less adapted to drought and in physiological disadvantage under limited water conditions
1 - hidróxi - 4 - oxo - 2,5 - ciclohexadieno - 1 - acetato de etila em Jacaranda mimosaefolia D. Don - Bignoniaceae
1-hydroxy-4-oxo-2,5-ciclohadien-1-ethyl acetate has been isolated from leaves and fruits of Jacaranda mimosaefolia D. Don, Bignoniaceae growing in Rio Grande do Sul, Brasil.Cromatografia em camada delgada de um extrato de Jacarada mimosaefolia D. Don mostrou a presença de 1-hidróxi-4-oxo-2,5-ciclohexadieno-1-acetato de etila nas folhas e frutos do vegetal.
Detecção de atividade antibacteriana in vitro nos extratos brutos obtidos a partir do plasmódio de Physarella oblonga (Berk. & Curt.) Morgan (Myxomycetes)
Isolamento de gnafalina a partir de Achyrocline alata (HBK) D. C.
A flavonoid was isolated from flowering stems of Achyrocline alata and structure was assigned to it by comparison with an authentic sample of 5-hydroxy-7, 8-dimethoxy-favonol.Dos caules floridos de Achyrocline alata foi isolado um flavonoide e a sua estrutura foi determinada por comparação com amostra autêntica de 5-hidroxi-7, 8-dimetoxi-flavonol
The Temporal Pattern of Mating Behavior of the Fruit Fly, Anastrepha zenildae in the Laboratory
The state of Rio Grande do Norte is an important fruit-producing and exporting area in northeastern Brazil. The success of this industry depends on fruit fly population control, especially in fly-free exporting zones. However, many fruits are not exported because of quarantine restrictions imposed by importing countries. A survey in the state has detected a considerable increase of the fruit fly, Anastrepha zenildae Zucchi (Diptera: Tephritidae), probably a result of the introduction of irrigated guava orchards that make fruit available all year. Knowledge of the sexual behavior of Tephritidae has great importance to pest control programs, particularly those that employ the Sterile Insect Technique. In order to characterize the reproductive behavior of A. zenildae, 32 individuals (16 males; 16 females) in each of six generations were submitted to an artificial 12:12 L:D cycle (750: < 1 lux, lights on 07:00–19:00) and observed over their lifetimes. The courtship and copulation occurred in leks and the episodes varied with the time of day, courtship being most frequent between Zeitgeber time (ZT) 3 and ZT 7, peaking at ZT 5–6. Copulations occurred between ZT 2 and ZT 8, with a higher frequency between ZT 5–7 and a peak at ZT 6. Mean duration was 0.28 ± 0.03 min/male (range: 5–163 min). Males in the leks attempted to copulate mainly between ZT 3 and ZT 7 with a peak at ZT 6, and males outside leks peaked at ZT 7. The different timing of sexual behaviors among related sympatric species, including A. zenildae, may contribute to species isolation
Alternative PCR protocol using a single primer set for assessing DNA quality in several tissues from a large variety of mammalian species living in areas endemic for leishmaniasis
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