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991.
do Vale A Costa-Ramos C Silva A Silva DS Gärtner F dos Santos NM Silva MT 《Cellular microbiology》2007,9(4):988-1003
Bacterial modulation of phagocyte cell death is an emerging theme in pathogenesis. Here we describe the systemic destruction of macrophages and neutrophils by the Gram-negative Photobacterium damselae ssp. piscicida (Phdp) in fish pasteurellosis, a deadly systemic infection. Following experimental inoculation, Phdp spreads by bacteraemia and colonizes the organs, producing a septicaemic infection, and secretes the apoptogenic exotoxin AIP56 which is systemically disseminated. In experimental and natural pasteurellosis, destruction of macrophages and neutrophils by secondary necrosis following caspase-3-associated apoptosis was seen predominantly in the spleen, head kidney and gut lamina propria. Identical phagocyte destruction occurred after injection of rAIP56, but not of heat-inactivated rAIP56, or AIP56-negative Phdp strains, indicating that AIP56 is responsible for phagocyte destruction occurring in pasteurellosis. Active caspase-3 and active neutrophil elastase are present in the blood in advanced infection, indicating that phagocyte lysis by secondary necrosis is accompanied by release of tissue-damaging molecules. The AIP56-induced lysis of phagocytes represents a very efficient, self-amplifying etiopathogenic mechanism, because it results in two effects that operate in concert against the host, namely, evasion of the pathogen from a crucial defence mechanism through the destruction of both professional phagocytes, and release of tissue-damaging molecules. The induction by a bacterial exotoxin of in vivo systemic lysis of both professional phagocytes by secondary necrosis, now described for the first time, may represent an overlooked etiopathogenic mechanism operating in other infections of vertebrates. 相似文献
992.
Vera MF da Silva Anthony M Carter Carlos E Ambrosio Ana F Carvalho Marina Bonatelli Marcelo C Lima Angelica Maria Miglino 《Reproductive biology and endocrinology : RB&E》2007,5(1):26-6
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that
of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing
two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle
bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion.
The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium
were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions
with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised
and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested
within Artiodactyla as sister group to the hippopotamids. 相似文献
993.
994.
The predaceous mite Amblyseius herbicolus (Chant) is the second most abundant phytoseiid on coffee plants (Coffea arabica L), after Euseius alatus DeLeon, in Lavras, MG, Brazil, associated to the vector of the coffee ring spot virus, Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae). Its life history was studied taking into account biological aspects, life table, predatory activity and functional and numerical responses in relation to the density of the prey. The adult female has longevity of 38 days when supplied with B. phoenicis. The intrinsic rate of population increase (r m) was 0.150 and the mean generation time (T) 25.3 days. The population doubles every 4.6 days. Thirty mites B. phoenicis /3-cm diameter coffee leaf arenas were separately offered to one specimen of each predator phase. Adult females were more efficient in killing all developmental phases of B. phoenicis, followed by the nymph stages. For the functional and numerical responses studies, from 0.14 to 42.3 immature specimens of the prey /cm(2) of arena were submitted to the predator, the preferred phase for predation. Predation and the oviposition of A. herbicolus increased with increasing prey density, with a positive and highly significant correlation. Regression analysis suggests a functional type II response, with a maximum daily predation near 35 B. phoenicis /cm(2) /one adult female. 相似文献
995.
Abramson CI Wanderley PA Wanderley MJ Silva JC Michaluk LM 《Neotropical Entomology》2007,36(6):828-835
It was recently discovered that exposure to small concentrations of the essential oils of sweet fennel (Foeniculum vulgare Mill) or pignut [Hyptis suaveolens (L.) Poit] can be used to control aphids. What is not known is whether these oils also influence honeybee behavior. Experiments using both harnessed and free-flying foragers at concentrations used to control aphids showed that bees readily associated the odors with a reward, discriminated between them, and were not repelled. Honeybees, however, would not consume the oils when mixed with sucrose to create an unconditioned stimulus. An experiment in which harnessed bees consumed various concentrations showed that concentrations greater than 50% were detrimental. The experiments reported here provide further evidence supporting the use of conditioning techniques to evaluate the use of essential oils on honey bee behavior. 相似文献
996.
Biological aspects of the caterpillar Macrosoma tipulata Hübner and its damage to young leaves of Theobroma grandiflorum (Wild ex Spreng Schum) were studied under laboratory conditions of 24.5 +/- 0.7 masculineC, UR 61.6 +/- 9.1% and 12h photophase. The larval stage presented five instars with a total duration of 15.9 +/- 4.31 days, and survival of 98%. The pupal period stage was 7.0 +/- 0.56 days for males and 6.9 +/- 0.56 days for females, with 99% survival for both sex. The pupal mean length was 18.9 +/- 0.89 mm for males and 19.1 +/- 1.13 mm for females. The mean longevity of the adult was 10.3 +/- 2.25 days. The vertical distribution of damage was relatively uniform, with a tendency of greater defoliation in the middle of the treetop, but without significant difference among the three positions. 相似文献
997.
The genus Lutzomyia has great importance in the New World, with some species implicated in the transmission of causal agents of leishmaniases, bartonellosis and arboviruses. From April 2003 to June 2004 an investigation was undertaken on the richness and abundance of the sand fly fauna in the northeast area of Manacapuru county, Amazonas State. The captures were carried out, with 16 light traps CDC, in areas of forest known as terra firme along the highway Manuel Urbano. In the period of 13 months we collected a total of 10,446 sandfly specimens, 3,908 males (38%) and 6,465 females (62%), distributed in 43 species belonging to the genus Lutzomyia, 10 subgenera and six species groups. These results evidenced a diversified and abundant sand fly fauna, with some species not yet reported for Manaus county, close to the study area. 相似文献
998.
Generalist foraging behavior among stingless bees is accepted but untested, as well as the subsidiary hypothesis of floral preferences in the genus Melipona. Here we analyzed those hypotheses comparing the use of floral sources of pollen, through paired analyses of pollen samples from different colonies of Melipona scutellaris Latreille, in three areas of the Atlantic Forest Domain, in Northern Brazil. From August, 2004 to January, 2005, monthly samples of pollen were collected at the entrance of twelve colonies of M. scutellaris. In two places, four colonies of M. scutellaris were compared with four colonies of africanized Apis mellifera L. The main pollen sources chosen by the colonies of M. scutellaris were flowers of the following plant families, in decreasing order of importance: Myrtaceae, Mimosaceae, Anacardiaceae, Sapindaceae, Caesalpiniaceae and Fabaceae. Productive pollen sources of Asteraceae, Arecaceae e Rubiaceae were heavily exploited by the colonies of A. mellifera and discharged by the colonies of M.scutellaris. Often, both species shared the main productive pollen sources, as the flowers of Myrtaceae and Mimosaceae. On the other hand, no pollen sources were heavily exploited altogether by both of them, as a rule. In different places and periods, the colonies of M. scutellaris presented high intra-specific similarity and they formed distinct clusters apart from A. mellifera. Therefore, the selection of pollen sources by colonies was species dependent. The paired comparisons refute the hypothesis of random flower exploitation by colonies and give support to the subsidiary hypothesis of selectivity or floral preferences by M.scutellaris. 相似文献
999.
Mariana Cardoso Helena Silva Carla Patinha Natlia Costa Susana Nunes ngela Cunha 《The Annals of applied biology》2022,180(1):99-108
The halophyte species Salicornia ramosissima has long been consumed as food and is currently regarded as a high-value gourmet item. However, given that these plants grow in estuarine areas, often impacted by pollution, and are prone to the accumulation of ions, the risks associated with food borne pathogens or toxic metals has to be carefully considered. The objective of this work was to gather evidence that S. ramossissima harvested locally in an estuarine system (Ria de Aveiro, Portugal) can be safely consumed as a healthy and catering-amenable food. Fresh shoots, taken as green vegetables, and dried powdered shoots (green salt) intended as seasoning, were analysed for total aerobic bacteria, total coliforms, Escherichia coli, Bacillus cereus and fungi (yeasts and moulds). The nutritional profile and the concentration of macro and micro elements, including potential toxic elements, was also established. Fresh shoots and green salt were incorporated in catering meals (soup and a meat dish) and subjected to sensory analyses. The microbiological quality of fresh shoots and green salt was compliant with the guidelines for salad greens and herbs and spices, respectively. The nutritional and elemental profile revealed that fresh shoots have a high content in fibre and NaCl. From the concentration of Na determined in green salt, a daily dose of 7 g was estimated as corresponding to the recommended daily dietary intake Na. None of the other elements was present in concentrations that could exceed the dietary intake limits. In the sensory tests, fresh shoots were well accepted as salad greens but green salt, used as seasoning, was considered as insufficient in terms of saltiness and does not completely substitute cooking salt. The results confirm the nutritional and sensory value of S. ramossisima and represent a promising prospect for the incorporation of locally harvested or crop cultivated plants in catering meals. 相似文献
1000.
Bunholi Ingrid Vasconcellos da Silva Ferrette Bruno Lopes Domingues Rodrigo Rodrigues Rotundo Matheus Marcos Cuevas Juan Martín García Mirta Gómez Sebastián de Freitas Renato Hajenius Aché Oliveira Claudio Foresti Fausto Mendonça Fernando Fernandes 《Hydrobiologia》2022,849(9):2177-2192
Hydrobiologia - The angular angelshark (Squatina guggenheim) is a coastal endangered angel shark from the Southwest Atlantic Ocean and one of the major bycatch victims. Despite major concerns about... 相似文献