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101.
Palmeira VF Kneipp LF Alviano CS dos Santos AL 《FEMS immunology and medical microbiology》2006,46(1):21-29
We investigated the possible secretion of peptidases by F. pedrosoi, when conidial cells were cultured in two distinct media. Aspartyl proteolytic activity was detected on the Czapeck-Dox-derived supernatant, which was blocked by pepstatin, and only active in extremely acidic conditions. The supernatant obtained after conidia growth in Kauffman medium presented metallopeptidase activity, which was active over a broad pH range and sensitive to 1,10-phenanthroline and EGTA. Additionally, both culture supernatants were able to cleave a wide range of proteinaceous substrates, including important human serum proteins (e.g. albumin and immunoglobulin G) and extracellular matrix components (e.g. fibronectin and laminin). As peptidases participate in different cellular metabolic pathways, we also tested the influence of proteolytic inhibitors on the F. pedrosoi conidia development in vitro. The metallopeptidase inhibitors, 1,10-phenanthroline, EGTA and EDTA, strongly abrogated the growth of conidial forms by approximately 95%, 85% and 60%, respectively. Moreover, 1,10-phenanthroline blocked the differentiation process from conidia to mycelia, an essential step during the F. pedrosoi life cycle. Phenylmethanesulfonyl fluoride, a serine peptidase inhibitor, slightly reduced the conidial growth, whereas proteolytic inhibitors of cysteine (E-64) and aspartic (pepstatin) type peptidases did not alter conidial developmental behavior. In summary, our results showed for the first time the expression of extracellular proteolytic activity by F. pedrosoi conidial cells. 相似文献
102.
Corrêa S Palmeira P Carneiro-Sampaio MM Sanae Nishimura L Guth BE 《FEMS immunology and medical microbiology》2006,47(2):199-206
Diarrhea is an important cause of morbidity and mortality amongst infants of low socio-economic levels in developing countries and in travelers who visit such areas. Enterotoxigenic E. coli strains express two sets of virulence-associated factors: enterotoxins (heat-stable toxins or heat-labile toxins) and colonization factors. Studies have shown that breast-feeding protects infants against infectious diseases, such as diarrhea, as it presents a great variety of immunological components. The aim of this study was to analyze the reactivity of immunoglobulin A from human colostrum to colonization factor antigens I and II. The colostrum ability in preventing enterotoxigenic E. coli adhesion to Caco-2 cells was also evaluated. Colostrum samples were collected from 32 healthy women, and a human colostrum pool was prepared. Enterotoxigenic E. coli strains expressing colonization factor antigens I and II were utilized. The colostrum pool and individual samples showed variable antienterotoxigenic E. coli immunoglobulin A titers, that were reactive with colonization factor antigen I and CS1/CS3 (colonization factor antigen II). The human colostrum pool and individual samples inhibited enterotoxigenic E. coli colonization factor antigen I and II adhesion to Caco-2 cells, at variable levels, and this ability was a result of immunoglobulin A antibodies reactive to these colonization factors. The immunoglobulin A-depleted pool lost this inhibitory ability. As bacterial adhesion is the initial mechanism of enterotoxigenic E. coli infection, breast-feeding could protect the offspring against diarrhea caused by this agent. 相似文献
103.
Carla Cristina Braz Louly Sara Fernandes Soares Diana da Nóbrega Silveira Marcelo Sales Guimarães Lígia Miranda Ferreira Borges 《Experimental & applied acarology》2010,51(4):353-362
To ascertain whether brown dog tick Rhipicephalus sp. infests resistant (beagle) and susceptible (English cocker spaniel) dogs differently, five animals of each breed were
maintained in a kennel whose walls were infested with 7,000 larvae, 320 nymphs, 80 males and 80 females, in 3 infestations,
at 10-day intervals. Five times more ticks were found on cocker spaniels (498) than on beagles (96). Substances were collected
by rubbing pieces of clean flannel on the dogs for 15 min and these were tested for arrestment and attractiveness of ticks.
Three choices were offered: cocker extract vs. control; beagle extract vs. control, and cocker extract vs. beagle extract.
When allowed to choose between substances rubbed from dogs and a control, more ticks were arrested by extracts from the cockers
than from beagles. In the arrestment tests with only a choice between substances from dogs of each breed, more ticks were
arrested by cocker substances. To test for attraction, capsules containing adsorbent were used and the tests were carried
out in a Y-olfactometer. Fifteen males and 15 females were tested, for each treatment. In the olfactometer, the ticks were
not attracted to the odor of either breed, however the odor of the Beagle was apparently repellent. These results indicate
that R. sanguineus can use substances from the dogs to differentiate susceptible English Cocker Spaniels from resistant Beagles. 相似文献
104.
Elsa Lamy Gonçalo Graça Gonçalo da Costa Catarina Franco Fernando Capela e Silva Elvira Sales Baptista Ana Varela Coelho 《Proteome science》2010,8(1):65
Background
Previous studies suggested that dietary tannin ingestion may induce changes in mouse salivary proteins in addition to the primarily studied proline-rich proteins (PRPs). The aim of the present study was to determine the protein expression changes induced by condensed tannin intake on the fraction of mouse whole salivary proteins that are unable to form insoluble tannin-protein complexes. Two-dimensional polyacrylamide gel electrophoresis protein separation was used, followed by protein identification by mass spectrometry. 相似文献105.
Márcio V. Ramos Thalles B. Grangeiro Eder A. Freire Maurício P. Sales Diego P. Souza Eliane S. Araújo Cleverson D. T. Freitas 《Arthropod-Plant Interactions》2010,4(1):57-67
The defensive role of the latex of Calotropis procera has recently been reported. In this study, latex proteins involved in detrimental effects on insects were evaluated on another important crop pest. The latex was fractionated to obtain its major protein fraction, which was then used to evaluate its insecticidal properties against Callosobruchus maculatus (Coleoptera: Bruchidae) in artificial bioassays. Laticifer proteins (LP) were investigated to characterize their action in such an activity. LP was highly insecticidal at doses as low as 0.1% (W/W). This effect was slightly augmented in F1 generation reared in artificial seeds containing LP at similar proportions of F0, but was fully reversed when F1 developed in LP-free seeds. The insecticidal proteins were not retained in a chitin column, and did not lose their insecticidal activity, even after heat treatment or pronase digestion. However, these samples inhibited papain (EC 3.4.22.2) activity and gut proteases of C. maculatus larvae, and a reverse zymogram showed the presence of protein bands resistant to papain digestion. These activities were not observed in unheated LP as they were probably masked by abundant endogenous cysteine protease (EC 3.4.22.16) activity present in unheated LP. LP was resistant to proteolysis when assayed with C. maculatus gut extract. However, gut proteins of C. maculatus were digested when incubated with LP. These observations and the deleterious effects of LP upon C. maculatus, reinforce the hypothesis that laticifer fluids are involved in plant defense against insects and indicate C. procera latex to be a source of promising insecticidal proteins. The inhibitor of proteolysis present in the latex seems to be resistant to heat and proteolysis and is certainly involved in the detrimental effects observed. 相似文献
106.
Emiret O. Faria Lucilia Kato Cecília M.A. de Oliveira Brenda G. Carvalho Cleuza C. Silva Lilian S. Sales Ivânia T.A. Schuquel Elisângela P. Silveira-Lacerda Piero G. Delprete 《Phytochemistry letters》2010,3(3):113-116
Two new quaternary alkaloids, compound 1 and the 14-oxo derivative 2, were isolated along with the known alkaloid strictosamide (3) from the leaves of Psychotria prunifolia (Kunth) Steyerm. (Rubiaceae, Psychotriae). Their structures were elucidated using spectroscopic methods (1D and 2D NMR, IR, and HRMS). 相似文献
107.
Ueda-Nakamura T Mendonça-Filho RR Morgado-Díaz JA Korehisa Maza P Prado Dias Filho B Aparício Garcia Cortez D Alviano DS Rosa Mdo S Lopes AH Alviano CS Nakamura CV 《Parasitology international》2006,55(2):99-105
Leishmaniasis is a group of diseases with a large spectrum of clinical manifestations caused by protozoans of the genus Leishmania. Here we demonstrate the leishmanicidal activity of the essential oil of Ocimum gratissimum as well as its main constituent, eugenol. The eugenol-rich essential oil of O. gratissimum progressively inhibited Leishmania amazonensis growth at concentrations ranging from 100 to 1000 microg/ml. The IC50 (sub-inhibitory concentration) of the essential oil for promastigotes and amastigotes were respectively 135 and 100 microg/ml and the IC50 of eugenol was 80 microg/ml for promastigote forms. L. amazonensis exposed to essential oil at concentrations corresponding to IC50 for promastigotes and for amastigotes underwent considerable ultrastructural alterations, as shown by transmission electron microscopy. Two or more nuclei or flagella were observed in 31% and 23.3% of treated amastigote and promastigote forms, respectively, suggesting interference in cell division. Considerable mitochondrial swelling was observed in essential oil-treated promastigotes and amastigotes, which had the inner mitochondrial membrane altered, with a significant increase in the number of cristae; in some amastigotes the mitochondrial matrix became less electron-dense. The minimum inhibitory concentration for both promastigotes and amastigotes was 150 microg/ml. Pretreatment of mouse peritoneal macrophages with 100 and 150 microg/ml essential oil reduced the indices of association between promastigotes and the macrophages, followed by increased in nitric oxide production by the infected macrophages. The essential oil showed no cytototoxic effects against mammalian cells. This set of results suggests that O. gratissimum essential oil and its compounds could be used as sources for new antileishmanial drugs. 相似文献
108.
Kannan RY Salacinski HJ Sales KM Butler PE Seifalian AM 《Cell biochemistry and biophysics》2006,45(2):129-136
It has been recognized that seeding vascular bypass grafts with endothelial cells is the ideal method of improving their long-term
patency rates. The aim of this study was to assess the in vitro cytocompatibility of a novel silica nanocomposite, polyhedral
oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU) and hence elicit its feasibility at the vascular interface
for potential use in cardiovascular devices such as vascular grafts. Using primary human umbilical vein endothelial cells
(HUVEC), cell viability and adhesion were studied using AlamarBlue assays, whereas cell proliferation on the polymer was assessed
using the PicoGreen dye assay. Cellular confluence and morphology on the nanocomposite were analyzed using light and electron
microscopy, respectively. Our results showed that there was no significant difference between cell viability in standard culture
media and POSS-PCU. Endothelial cells were capable of adhering to the polymer within 30 min of contact (Student's t-test, p<0.05) with no difference between POSS-PCU and control cell culture plates. POSS-PCU was also capable of sustaining good cell
proliferation for up to 14d even from low seeding densities (1.0×103 cells/cm2) and reaching saturation by 21 d. Microscopic analysis showed evidence of optimal endothelial cell adsorption morphology
with the absence of impaired motility and morphogenesis. In conclusion, these results support the application of POSS-PCU
as a suitable biomaterial scaffold in bio-hybrid vascular prostheses and biomedical devices. 相似文献
109.
Philip Batterham Ayscha Hill-Williams Garry Levot Narelle Sales John A McKenzie 《Australian Journal of Entomology》2006,45(1):87-90
Abstract Several genes on chromosomes IV and VI have a significant influence on high-level resistance to diflubenzuron in a strain of the Australian sheep blowfly from Tara, Queensland. Low-level resistance to cyromazine in the same strain is due to genes on these chromosomes with a gene (gene complex) in the sv marker region of chromosome IV being particularly important. For both insecticides, genetic background influences resistance status. If the results of the Tara strain prove typical for those of other populations, resistance to diflubenzuron in the Australian sheep blowfly has potentially significant consequences for woolgrowers. 相似文献
110.
A A Nascimento A Sales T R D Cardoso N L Pinheiro R M M Mendes 《Revista brasleira de biologia》2007,67(4):735-740
In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP), YY polypeptide (PYY) and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin-Immunoreactive cells to (B cells) were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets. 相似文献