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941.
Susan Morrison Grace John-Stewart John J. Egessa Sezi Mubezi Sylvia Kusemererwa Dennis K. Bii Nulu Bulya Francis Mugume James D. Campbell Jonathan Wangisi Elizabeth A. Bukusi Connie Celum Jared M. Baeten Partners PrEP Study Team 《PloS one》2015,10(10)
During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting. 相似文献
942.
Paraskevi Agrafioti Christos G. Athanassiou Thomas N. Vassilakos George Vlontzos Frank H. Arthur 《PloS one》2015,10(11)
We evaluated knockdown caused by four insecticides: alpha-cypermethrin, chlorfenapyr, pirimiphos-methyl and fipronil against adults of Tribolium confusum Jacquelin Duval, the confused flour beetle and Oryzaephilus surinamensis (L.), the sawtoothed grain beetle. Bioassays were conducted on concrete and metal surfaces. Adults of the tested species were exposed on both surfaces treated with the above insecticides at two doses (low and high). Knockdown assessment was done after 15, 30 and 60 min of adult exposure in the treated surfaces. Also, after 1, 3, 5, 7 and 14 d of exposure, a lethality index was calculated with an equation resulting to values from 0 to 100, where 100 indicated complete mortality and 0 complete survival. We also developed a lethality index by ranking each adult on each surface from 0 to 4, 0: adults moved normally, 1: adults were knocked down, but were able to walk for short intervals, 2: adults were knocked down and unable to walk, but with visible movement of antennae etc., 3: adults were knocked down, with very minimal movement of the tarsi and the antennae and 4: adults were dead (no movement). Knockdown of adults immediately after exposure (15–60 min) was higher for pirimiphos-methyl followed by alpha-cypermethrin, for both dose rates tested and species, but only on the metal surface. The lethality index was nearly 100 for all insecticides after 5d of exposure for O. surinamensis, while for T. confusum the adult lethality index was considerably lower for alpha-cypermethrin, suggesting that that recovery from knockdown occurred. Chlorfenapyr was the only insecticide that was more effective on concrete than on metal, while the reverse was noted for the other three insecticides. These results show that knockdown has different levels, which can be used as indicators of insect mortality or recovery. 相似文献
943.
Using a combination of a primary growth retardant, mefluidide, a synergistic additive, chlorsulfuron, a detergent to enhance penetration (X-77), and a herbicide, 2,4-D, to provide for control of broadleaf weeds, full-season management of bluegrass (Poa pratensis L.)—tall fescue (Festuca arundinaceae Schreb.) mixtures along roadsides has been achieved. A single spray application is made in the spring, and no additional herbicide applications or mechanical mowing are needed. The treatment is effective with greater than 90% control of fescue seed heads. Those few seed heads that do form remain short. It is economical. The costs of materials and application are equal to or less than the cost of a single mowing cycle. The treatment is environmentally safe when applied in early spring before most agricultural crops have been planted. The effectiveness and low cost of the combination derive from laboratory and greenhouse observations that various materials, herein referred to as additives, often only weakly effective as growth retardants themselves, will interact synergistically with mefluidide to provide overall treatment effectiveness at application rates that are economical. Using this principle, a combination suitable for roadside vegetation management was devised, field-tested for 2 years under actual use conditions, and found to be effective for full-season vegetation management of mixed bluegrass—tall fescue turf to permit considerable cost savings when compared to three-cycle mechanical mowing. 相似文献
944.
945.
946.
947.
Anthony J. Hesketh Caroline Maloney Christopher A. Behr Morris C. Edelman Richard D. Glick Yousef Al-Abed Marc Symons Samuel Z. Soffer Bettie M. Steinberg 《PloS one》2015,10(12)
Metastatic Ewing Sarcoma carries a poor prognosis, and novel therapeutics to prevent and treat metastatic disease are greatly needed. Recent evidence demonstrates that tumor-associated macrophages in Ewing Sarcoma are associated with more advanced disease. While some macrophage phenotypes (M1) exhibit anti-tumor activity, distinct phenotypes (M2) may contribute to malignant progression and metastasis. In this study, we show that M2 macrophages promote Ewing Sarcoma invasion and extravasation, pointing to a potential target of anti-metastatic therapy. CNI-1493 is a selective inhibitor of macrophage function and has shown to be safe in clinical trials as an anti-inflammatory agent. In a xenograft mouse model of metastatic Ewing Sarcoma, CNI-1493 treatment dramatically reduces metastatic tumor burden. Furthermore, metastases in treated animals have a less invasive morphology. We show in vitro that CNI-1493 decreases M2-stimulated Ewing Sarcoma tumor cell invasion and extravasation, offering a functional mechanism through which CNI-1493 attenuates metastasis. These data indicate that CNI-1493 may be a safe and effective adjuvant agent for the prevention and treatment of metastatic Ewing Sarcoma. 相似文献
948.
949.
Determination of products of acetohydroxy acid synthase by the colorimetric method, revisited 总被引:2,自引:0,他引:2
The enzyme acetohydroxy acid synthase (AHAS, EC 4.1.3.18) catalyzes two competing reactions of physiological importance: condensation of two molecules of pyruvate to form acetolactate (AL) or condensation of pyruvate and 2-ketobutyrate to form acetohydroxybutyrate (AHB). The activity of AHAS is most frequently analyzed using the Westerfeld method, in which the acetoin formed upon decarboxylation of AL is determined by colorimetric reaction with creatine and alpha-naphthol. However, there has been confusion as to the interpretation of the results of this assay in the presence of both substrates, conditions which lead to formation of both AL and AHB. By applying this assay to enzymatically prepared samples of AL and AHB which have also been analyzed by two other independent methods, we show here that the color yield for AHB in the commonly used assay is 35-40% that for equivalent amounts of acetoin or AL. The relative color yield is not significantly affected by varying the time or temperature of various steps in the color-forming reaction. This information could in principle be used, together with an independent specific assay for AHB, to determine the composition of an AHAS product mixture; it would, however, be less accurate than a simultaneous chromatographic method. 相似文献
950.
A comparison of vector population indices for forecasting barley yellow dwarf virus in autumn sown cereal crops 总被引:1,自引:0,他引:1
Two approaches based on the concept of a vector population index are considered as possible deterministic elements for an empirical forecast of barley yellow dwarf virus (BYDV) in autumn sown cereals. The first, an aerial vector index, is a further elaboration of the infectivity index proposed by Plumb, Lennon & Gutteridge (1981), which assumes that virus damage is a function of the number of infective migrant alatae of the two main aphid vectors, Rhopalosiphum padi L. and Sitobion avenae F., integrated over time from crop planting or emergence. The new formulation, however, excludes holocyclic alate morphs (i.e. males and gynoparae) of the former species, which, although generally abundant in autumn, are nevertheless perceived as relatively unimportant virus vectors since they colonise only the alternative woody host, Prunus padus (the bird-cherry tree). The second approach, a crop vector index, is a more fundamental departure which argues that field populations of viruliferous aphids, both alatae and apterae, which have already colonised cereals, may be a better criterion of potential virus spread than the density of aerial migrant vectors. This index retains a similar integral form, but evaluates crop exposure to BYDV as accumulated infectious aphid-days. A method is described whereby this function can be derived from irregular or infrequent aphid samples in the crop. Both methods, unlike Plumb's (1976) original concept, produced indices which were significantly related to subsequent virus infection and yield loss in winter barley at Long Ashton (S.W. England, UK), 1978–1986. The best models were obtained with the crop vector index, fitted to observed virus infection by generalised linear regression using a complementary log-log link function, or to observed yield loss by simple linear regression using a log transformation of yield (r = 0.84 in each case; compared with r-values > 0.65 for the aerial vector index, and > 0.35 for Plumb's (1976) index). However, the residual errors and hence confidence limits of these fitted regressions were too large for predicting damage that was significantly less than a reasonable economic damage threshold for BYDV control. Analyses of the separate components of each index showed a good general relationship between aphid infectivity and the severity of crop infection, confirming the epidemiological importance of this factor. The functional expressions of aphid density, however, were not significant. This evident weakness in the models, and alternative approaches to BYDV forecasting are discussed. 相似文献