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91.
92.
Ruizhong Shen John C. Kappes Lesley E. Smythies Holly E. Richter Lea Novak Phillip D. Smith 《Journal of virology》2014,88(13):7683-7688
We report that primary human vaginal dendritic cells (DCs) display a myeloid phenotype and express CD4, CCR5, and CXCR4. Vaginal CD13+ CD11c+ DCs rapidly and efficiently bound transmitted/founder (T/F) CCR5-tropic (R5) viruses, transported them through explanted vaginal mucosa, and transmitted them in trans to vaginal and blood lymphocytes. Vaginal myeloid DCs may play a key role in capturing and disseminating T/F R5 HIV-1 in vivo and are candidate “gatekeeper” cells in HIV-1 transmission. 相似文献
93.
Lise Musset Stéphane Pelleau Romain Girod Vanessa Ardillon Luisiane Carvalho Isabelle Dusfour Margarete SM Gomes Félix Djossou Eric Legrand 《Memórias do Instituto Oswaldo Cruz》2014,109(5):525-533
In a climate of growing concern that Plasmodium falciparum may be
developing a drug resistance to artemisinin derivatives in the Guiana Shield, this
review details our current knowledge of malaria and control strategy in one part of
the Shield, French Guiana. Local epidemiology, test-treat-track strategy, the state
of parasite drug resistance and vector control measures are summarised. Current
issues in terms of mobile populations and legislative limitations are also
discussed. 相似文献
94.
The aquatic and terrestrial realms differ in many physical properties that not only require specific physiological adaptations but also cause differences in dispersal options. We thus expect that life-history traits related to dispersal and colonization are under selection pressure because freshwater habitats are more isolated and thus more difficult to reach. We compared traits from European databases of three taxonomic groups along the passive–active dispersal gradient: plants (Plantes), snails (Mollusca: Gastropoda: Prosobranchia et Pulmonata) and hoverflies (Diptera: Syrphidae), all of which have both terrestrial and freshwater species (plants and snails) or early life stages (hoverflies). Aquatic taxa seem to be more successful long-distance dispersers than are terrestrial taxa. Our analysis also revealed lower numbers of seeds or eggs produced in the aquatic habitats. However, aquatic taxa often allocate resources to offspring guarding (vegetative propagules in plants, egg capsules in snails) and breeding-site selection (syrphids). Colonization of the aquatic realm is reinforced by increases in life span (plants), clonal spread (plants), shorter generation times (snails), selfing ability (marginal effect in pulmonate snails) or paedogenesis (two incidences in hoverflies, needs further studies). Probably, the variety of strategies reflects the different evolutionary backgrounds that elicit different combinations of trade-offs, but all traits also might increase invasibility of species. 相似文献
95.
Quantitative analysis of organophosphorus pesticides in freshwater using an optimized firefly luciferase‐based coupled bioluminescent assay
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In this paper, a coupled bioluminescent assay, relying on the coupling of the enzymes acetylcholinesterase, S‐acetyl‐coenzyme A synthetase and firefly luciferase, for the detection and quantitation of organophosphorus pesticides, is presented. Using malathion as a model organophosphorus pesticide, the assay was optimized through statistical experimental design methodology, namely Plackett–Burman and central composite designs. The optimized method requires only 20 μL of sample. The linear range for the assay was 2.5–15 μM of malathion, with limits of detection and quantitation of 1.5 and 5.0 μM, respectively. This simple, fast and robust method allows samples to be analyzed at room temperature and without any pretreatment. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
96.
Snake venoms are cocktails comprising combinations of different proteins, peptides, enzymes and toxins. Snake toxins have
diverse characteristics having different molecular configuration, structure and mode of action. Many toxins derived from snake
venom have distinct pharmacological activities. Venom from Bungarus fasciatus (commonly known as banded krait) is a species of
elapid snake found on the South East Asia and Indian sub-continent, mainly contains neurotoxins. Beta bungartotoxin is the major
fraction of Bungarus venom and particularly act pre-synaptically by obstructing neurotransmitter release. This toxin in other
snake species functionally forms a heterodimer containing two different subunits (A and B). Dimerization of these two chains is a
pre-requisite for the proper functionality of this protein. However, B. fasciatus bungartotoxin contains only B chain and their
structural orientation in yet to be resolved. Therefore, it is of interest to describe the predicted structure model of the toxin for
functional insights. In this work we analyzed the neurotoxic nature, their alignments, secondary and three dimensional structures,
functions, active sites and stability with the help of different bioinformatical tools. A comprehensive analysis of the predicted model
provides approaching to the functional interpretation of its molecular action. 相似文献
97.
Claire SM Kwan Rafael P Vázquez-Manrique Sung Ly Kshamata Goyal Howard A Baylis 《BMC physiology》2008,8(1):11
Background
Ultradian rhythms, rhythms with a period of less than 24 hours, are a widespread and fundamental aspect of life. The mechanisms underlying the control of such rhythms remain only partially understood. Defecation in C. elegans is a very tightly controlled rhythmic process. Underlying the defecation motor programme is an oscillator which functions in the intestinal cells of the animal. This mechanism includes periodic calcium release and subsequent intercellular calcium waves which in turn regulate the muscle contractions that make up the defecation motor programme. Here we investigate the role of TRPM cation channels in this process. 相似文献98.
Giant knotweeds (Reynoutria spp.) are highly productive and aggressive invaders in riparian wetlands of Europe and North America. We sampled ground-dwelling
beetles by pitfall traps from six sites comparing monotypic Reynoutria stands with the invaded native Urtica-dominated stands. Three sites were located in a semi-natural softwood forest and three sites were on a ruderal embankment.
The analyses are based on a total of 13,244 individuals from 218 species. Location and site significantly influenced beetle
assemblages. Moreover, there were pronounced differences between vegetation stands. The monotypic Reynoutria stands exhibited lower beetle abundance, species richness and rarefaction diversity irrespective of location. However, the
negative effect on species richness, abundance and assemblage similarities were stronger on the transformed ruderal embankment
than in the semi-natural softwood forest. Reynoutria invasion seems to influence microclimatic conditions. We found a higher abundance of silvicolous and a lower abundance of
xerophilous ground beetles in the Reyountria stands than in the Urtica-dominated stands. Feeding guilds reacted differently to Reynoutria invasion that reduced the abundance of predators and herbivores but enhanced that of detritivores. Detritivores assumingly
profit from the perennial presence of the large quantities of Reynoutria litter. We conclude that highly productive invaders pauperise the arthropod fauna and alter link strengths in trophic cascades
shifting primary producer-based food webs to detritus-based food webs. 相似文献
99.
Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin
lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed
from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and
their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly
treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group
UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August
due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move
to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better
weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the
value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture
infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better
despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments
of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without
dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where
routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed. 相似文献
100.
The agricultural sector, and particularly the horticultural production, has a singular importance in agriculture, considering that it ranks second on agricultural products, nationally and worldwide. Fungal diseases are one of the major causes of vegetable loss during storage, reducing their nutritional value, quality and sale price. Vegetables are usually exposed to diverse treatments with chemical products before storage; as a result, fungal populations develop an increased resistance over time becoming more difficult to control. Because of this, research efforts toward finding more suitable chemicals to control fungal diseases are needed. Natural extracts may be an alternative solve this problem. In the present investigation the fungicidal activity of aqueous and ethanol extracts of Agave scabra was evaluated on the growth of Botrytis cinerea, Mucor sp., Aspergillus niger, Fusarium sp. and Penicillium sp., whose strains were isolated from potato and tomato. To assess their effects, the agar-dilution and agar-well techniques were performed. The ethanol extract was more effective against Botrytis cinerea and Mucor sp. when the agar-well method was used. However, when using the agar-dilution method the ethanol extract of Agave scabra inhibited the growth of Botrytis cinerea, Mucor sp. and Penicillium sp. 相似文献