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排序方式: 共有177条查询结果,搜索用时 15 毫秒
31.
Effects of some lignans and neolignans on the development and excretion of Rhodnius prolixus. 总被引:2,自引:0,他引:2
The effects of six lignans and neolignans as inhibitors of ecdysis and on the water balance in fourth-instar larvae of Rhodnius prolixus were studied by oral, topical and continuous contact treatments. The main results may be summarised as follows: (i) burchellin, pinoresinol, sesamin, licarin A and nordihydroguaiaretic acid (NDGA) did not cause feeding inhibition at doses of 100 micrograms/ml blood; podophyllotoxin had no antifeedant effect but caused a high moulting inhibition and significant toxicity when applied either orally or topically; (ii) the highest ecdysis inhibitory effects were observed with pinoresinol and NDGA when applied orally at a dose of 100 micrograms/ml (58% and 50% of moulting inhibition, respectively); burchellin inhibited 30% of the moulting at this concentration; (iii) by topical treatment none of the compounds presented any influence on the moulting cycle; and (iv) podophyllotoxin and burchellin significantly reduced the excretion of the insect in 24 h; the other compounds had no effect on excretion. The implications of these findings in relation to the pertinent biological events in R. prolixus are discussed. 相似文献
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The bulbourethral glands of 323 Bos indicus or B. indicus crossbred bulls more than 1 1/2 years old were examined in an abattoir study. Bulbourethral adenitis was diagnosed grossly and confirmed by histological examination in 4 (1.2%). Unilateral chronic interstitial inflammation was seen in 2 cases; one of these was associated with a degenerative-type seminal vesiculitis. In the others adenitis was bilateral; in one case it was associated with a concretion and foreign (plant) material in the principal duct of the left bulbourethral gland; in the other bilateral case, numerous calculi were present and microscopically, a chronic active and diffuse inflammation was observed. Chemical analysis of the calculi showed calcium oxalate and tricalcium phosphate to be the most important components. Corynebacterium spp was isolated from the lesion with multiple calculi but attempts to isolate Chlamydia spp, Mycoplasma spp and Brucella abortus from the 4 adenitis cases were unsuccessful. Congenital abnormalities such as glandular fusion (2.2%) or unilateral aplasia (0.6%) were also observed. Cysts were the most common finding (19.2%), and duct dilation was frequent (7.1%). The significance of these findings in relation to fertility is considered. 相似文献
34.
dos Santos Alyce Raiana Monteiro Cabral Carla Heloísa Avelino Cabral Carlos Eduardo Avelino de Barros Lívia Vieira de Barros Jackelliny Melo Cabral Welton Batista Dias Milene Rodrigues 《Tropical animal health and production》2019,51(8):2395-2403
Tropical Animal Health and Production - This study evaluated the effect of energy and protein supplementation on the nutritional characteristics, ingestive behavior, and productive performance in... 相似文献
35.
Carlos Alberto Alves de Oliveira Filho José Augusto Gomes Azevêdo Gleidson Giordano Pinto de Carvalho Camilla Flávia Portela Gomes da Silva Ícaro dos Santos Cabral Luiz Gustavo Ribeiro Pereira Larissa Gomes dos Reis Flávio Moreira de Almeida Lígia Lins Souza 《Tropical animal health and production》2016,48(2):289-295
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Daniel Mageste de Almeida Marcos Inácio Marcondes Luciana Navajas Rennó Lívia Vieira de Barros Carla Heloísa Avelino Cabral Leandro Soares Martins David Esteban Contreras Marquez Felipe Vélez Saldarriaga Faider Alberto Castaño Villadiego Manuela Acevedo Cardozo Roman Maza Ortega Javier Enrique Garces Cardenas Virginia Lucia Neves Brandão Mário Fonseca Paulino 《Tropical animal health and production》2018,50(8):1771-1777
Beef cows’ milk yield is typically determined by measuring milk yield once daily and then doubling this value to estimate daily production. However, it is not known whether this is accurate. Thus, we aimed to determine the association between morning and afternoon milk yield in grazing Nellore cows. Eighty Nellore cows were used, with initial weight of 516.0?±?1.0 kg. The experiment was a completely randomized factorial scheme, with 20 replications and four treatments (i.e., +?or ??pre-partum supplementation in combination with +?or ??post-partum supplementation): PRMM—1 kg of supplement/cow/day for 90 days pre-partum; MMPS—1 kg of supplement/cow/day for 90 days post-partum; PRPS—1 kg of supplement/cow/day for 90 days pre-partum and 90 days post-partum; and MM—only mineral mix ad libitum during pre- and post-partum. Milk was sampled on days 45, 135, and 225 post-partum (early, middle, and late lactation, respectively). No effects were observed of pre- and post-partum supplementation on milk yield (P?>?0.05). The afternoon/morning proportion of 0.45 in the early third of lactation was higher than other stages, which had a proportion of 0.41 (P?<?0.05). Post-partum supplementation increased milk protein in the morning and afternoon milking (P?<?0.05). There was also no effect of pre- and post-partum supplementation on afternoon-morning proportion other milk components (P?>?0.05). We conclude that estimating daily milk production of grazing beef cattle by multiplying a once daily milking amount times two is not accurate. Under the conditions of this study, proportion of total daily production represented by the ratio of afternoon/morning milking was 0.45 in early lactation (first third) and 0.41 in mid- and late lactation. 相似文献
38.
Schuindt SH Oliveira BC Pimentel PM Resende TL Retamal CA DaMatta RA Seipel D Arnholdt AC 《Veterinary parasitology》2012,186(3-4):207-215
Toxoplasmosis is a world wide spread zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells for dispersal throughout the body. However, the molecular mechanisms or outcomes of the subversion of the host cell are largely unknown. Recently our group established that metalloproteinases are involved in migration of infected macrophages. Herein, we evaluated the recruitment of host invasive machinery components in T. gondii infected murine macrophages. We showed by immunoprecipitation assays that MMP-9, CD44 TIMP-1 and uPAR were secreted as a multi-protein complex by infected macrophages. Zymographic analysis revealed that MMP-9 was present in its pro- and active form. Moreover, inhibition of uPA/uPAR pathway by PAI-1 decreased secretion of MMP-9 active forms, as well those associated to uPAR and TIMP-1, but not to CD44. Data presented here suggest that MMP-9 is secreted as a multiprotein complex by T. gondii infected macrophages, similar to that observed in metastatic cells. We further speculate that uPA/uPAR system is involved in the expression/secretion of complexes containing active MMP-9 forms. 相似文献
39.
P. Silveira U. Vashist A. Cabral K. B. Amaral G. L. G. Soares M. Dagosto 《Tropical animal health and production》2009,41(7):1319-1323
Plasmodium juxtanucleare is one of the agents that cause avian malaria in chickens and little is known about the treatment of the infection. The aim
of this study was to compare the antimalarial activities of rutin and chloroquine in chickens infected with P. juxtanucleare after immunossuppression with corticosteroid. Antimalarial activity was verified in 33 fowls by evaluation of parasitemia
levels in Giemsa-stained blood smears taken to 30 days. Rutin did not exert a reduction in parasitemia from P. juxtanucleare when compared to chloroquine treatment that kept the parasites at a low level, demonstrating its antimalarial effect. During
the course of the infection, the trophozoite stage predominated (80%), followed by schizont (17%) and gametocyte (3%). Maximum
parasitemia levels were recorded on day 12 in control and rutin groups. There were no significant differences in the hematocrit
values, weight body or the temperature of the fowls among the groups evaluated (p > 0.05). 相似文献
40.
Alexandre R. Cabral Marlon A. Capanema Julia Gebert Joao F. Moreira Louis B. Jugnia 《Water, air, and soil pollution》2010,209(1-4):157-172
Stable isotope analyses were performed on gas samples collected within two instrumented biocovers, with the goal of evaluating CH4 oxidation efficiencies (f 0). In each of the biocovers, gas probes were installed at four locations and at several depths. One of the biocovers was fed with biogas directly from the waste mass, whereas the other was fed through a gas distribution system that allowed monitoring of biogas fluxes. While the f 0 values obtained at a depth of 0.1 m were low (between 0.0% and 25.2%) for profiles with poor aeration, they were high for profiles with better aeration, reaching 89.7%. Several interrelated factors affecting aeration seem to be influencing f 0, including the degree of water saturation, the magnitude of the biogas flux and the temperature within the substrate. Low f 0 values do not mean necessarily that little CH4 was oxidized. In fact, in certain cases where the CH4 loading was high, the absolute amount of CH4 oxidized was quite high and comparable to the rate of CH4 oxidation for cases with low CH4 loading and high f 0. For the experimental biocover for which the CH4 loading was known, the oxidation efficiency obtained using stable isotopes (f 0?=?55.67% for samples taken inside flux chambers) was compared to the value obtained by mass balance (f 0?=?70.0%). Several factors can explain this discrepancy, including the high sensitivity of f 0 to slight changes in the isotopic fractionation factor for bacterial oxidation, α ox, uncertainties related to mass flow metre readings and to the static chamber method. 相似文献