98 research outputs found
First report of eprinomectin-resistant isolates of Haemonchus contortus in 5 dairy sheep farms from the Pyrénées Atlantiques département in France
Infection of sheep by gastrointestinal nematodes (GIN) in pastoral systems such as those found in the South Western area of France, the Pyrénées Atlantiques, is one of the main reasons for economic loss and degradation of their welfare. In the present study, the efficacy of eprinomectin (EPN) was monitored on farms from this area following suspicion of lack of anthelmintic efficacy. Suspicions were raised by veterinarians, based on clinical signs ranging from milk and body condition loss, to anaemia, and mortality. Resistance was evaluated according to the World Association for the Advancement for Veterinary Parasitology (WAAVP) guidelines using fecal egg count reduction tests reinforced by individual analysis of drug concentration in the serum of all treated ewes by high-performance liquid chromatography (HPLC). EPN was administered by subcutaneous (SC) and topical (T) route according to manufacturer's requirements, as well as by the oral route (O) with the topical solution according to off-labelled practices in the field. For the first time in France, the presence of resistant isolates of Haemonchus contortus to EPN was observed in 5 dairy sheep farms. The HPLC dosages showed exposure of worms to concentrations compatible with anthelmintic activity for animals treated by the SC and O routes. By contrast, they showed under exposure to the drug of most individuals treated by the T route. EPN is the only null milk withdrawal anthelmintic molecule currently available. The presence of resistant isolates of the pathogenic H. contortus to EPN in this important dairy region requires an urgent change in grazing, and sometimes production, systems
What Is New for an Old Molecule? Systematic Review and Recommendations on the Use of Resveratrol
Stilbenes are naturally occurring phytoalexins that generally exist as their more stable E isomers. The most well known natural stilbene is resveratrol (Res), firstly isolated in 1939 from roots of Veratrum grandiflorum (white hellebore) (1) and since then found in various edible plants, notably in Vitis vinifera L. (Vitaceae) (2). The therapeutic potential of Res covers a wide range of diseases, and multiple beneficial effects on human health such as antioxidant, anti-inflammatory and anti-cancer activities have been suggested based on several in vitro and animal studies (3). In particular, Res has been reported to be an inhibitor of carcinogenesis at multiple stages via its ability to inhibit cyclooxygenase, and is an anticancer agent with a role in antiangiogenesis (4). Moreover, both in vitro and in vivo studies showed that Res induces cell cycle arrest and apoptosis in tumor cells (4). However, clinical studies in humans evidenced that Res is rapidly absorbed after oral intake, and that the low level observed in the blood stream is caused by a fast conversion into metabolites that are readily excreted from the body (5). Thus, considerable efforts have gone in the design and synthesis of Res analogues with enhanced metabolic stability. Considering that reduced Res (dihydro- resveratrol, D-Res) conjugates may account for as much as 50% of an oral Res dose (5), and that D-Res has a strong proliferative effect on hormone-sensitive cancer cell lines such as breast cancer cell line MCF7 (6), we recently devoted our synthetic efforts to the preparation of trans-restricted analogues of Res in which the E carbon-carbon double bond is embedded into an imidazole nucleus. To keep the trans geometry, the two aryl rings were linked to the heteroaromatic core in a 1,3 fashion. Based on this design, we successfully prepared a variety of 1,4-, 2,4- and 2,5-diaryl substituted imidazoles including Res analogues 1, 2 and 3, respectively, by procedures that involve transition metal-catalyzed Suzuki-Miyaura cross-coupling reactions and highly selective N-H or C-H direct arylation reactions as key synthetic steps.
The anticancer activity of compounds 1–3 was evaluated against the 60 human cancer cell lines panel of the National Cancer Institute (NCI, USA). The obtained results, that will be showed and discussed along with the protocols developed for the preparation of imidazoles 1–3, confirmed that a structural optimization of Res may provide analogues with improved potency in inhibiting the growth of human cancer cell lines in vitro when compared to their natural lead.
(1) Takaoka,M.J.Chem.Soc.Jpn.1939,60,1090-1100.
(2) Langcake, P.; Pryce, R. J. Physiological. Plant Patology 1976, 9, 77-86.
(3) Vang, O.; et al. PLoS ONE 2011, 6, e19881. doi:10.1371/journal.pone.0019881
(4) Kraft, T. E.; et al. Critical Reviews in Food Science and Nutrition 2009, 49, 782-799.
(5) Walle, T. Ann. N.Y. Acad. Sci. 2011, 1215, 9-15. doi: 10.1111/j.1749-6632.2010.05842.x
(6) Gakh,A.A.;etal.Bioorg.Med.Chem.Lett.2010,20,6149-6151
Ecophysiological and bioclimatic foundations for a global plant functional classification
Question: What plant properties might define plant functional types (PFTs) for the analysis of global vegetation responses to climate change, and what aspects of the physical environment might be expected to predict the distributions of PFTs?
Methods: We review principles to explain the distribution of key plant traits as a function of bioclimatic variables. We focus on those whole-plant and leaf traits that are commonly used to define biomes and PFTs in global maps and models.
Results: Raunkiær's plant life forms (underlying most later classifications) describe different adaptive strategies for surviving low temperature or drought, while satisfying requirements for reproduction and growth. Simple conceptual models and published observations are used to quantify the adaptive significance of leaf size for temperature regulation, leaf consistency for maintaining transpiration under drought, and phenology for the optimization of annual carbon balance. A new compilation of experimental data supports the functional definition of tropical, warm-temperate, temperate and boreal phanerophytes based on mechanisms for withstanding low temperature extremes. Chilling requirements are less well quantified, but are a necessary adjunct to cold tolerance. Functional traits generally confer both advantages and restrictions; the existence of trade-offs contributes to the diversity of plants along bioclimatic gradients.
Conclusions: Quantitative analysis of plant trait distributions against bioclimatic variables is becoming possible; this opens up new opportunities for PFT classification. A PFT classification based on bioclimatic responses will need to be enhanced by information on traits related to competition, successional dynamics and disturbance
Allergomic study of cypress pollen via combinatorial peptide ligand libraries
Although Cupressus sempervirens (Cups) pollen represents one of the main aeroallergens in southern Europe, only two Cups allergens have yet been identified and reported: Cup s 1 and Cup s 3.The aim of this study was to identify allergens in cypress pollen using an immuno-proteomic approach. A sequential pollen protein extn. was developed and supplemented by a combinatorial peptide ligand library (CPLL) treatment to select low-abundance species. Control exts. and CPLL eluates have then been resolved by 1-DE and 2-DE gel electrophoresis, blotted and confronted with sera from cypress allergic patients. Extd. proteins including IgE-binding components were identified using nanoLC-MS/MS anal. A total of 108 unique gene products were identified analyzing the eluates and control loaded onto 1-DE SDS-PAGE. Forty proteins were identified in control samples and 68 supplementary species upon CPLL treatment. Out of the 12 IgE-binding proteins characterized in 2-DE gels, 9 were already reported as allergens in various sources including the two major known allergens of Cupressaceae (groups 1 and 2). Three IgE-binding proteins, not previously reported as allergens, are newly described. The improvement in protein extn. combined with the enrichment of low-abundance species allowed us to extend the repertoire of potential cypress pollen allergen
Unravelling the long-strike variability of the Angola-Gabon rifted margin : a mapping approach.
International audienc
In-depth exploration of Hevea brasiliensis latex proteome and "hidden allergens" via combinatorial peptide ligand libraries
The proteome of Hevea brasiliensis latex has been explored in depth via combinatorial peptide ligand libraries. A total of 300 unique gene products have been identified in this latex, whose proteome has been largely unknown up to the present. In search for unknown allergens, control latex and eluates from the ligand libraries have been fractionated by two-dimensional mapping, blotted and confronted with sera of 18 patients. In addition to the already known and named Hevea major allergens, we have unambiguously detected several others like, for instance: heat shock protein (81 kDa), proteasome subunit (30 kDa), protease inhibitor (8 kDa), hevamine A (43 kDa) and glyceraldehyde-3-phosphate dehydrogenase (37 kDa). Gene Ontology analysis of analyzed fractions has shown that major functions are substantially unchanged after sample treatment, while novel biological functions appeared that were undetectable in the crude sampl
Identification of a polygalacturonase (Cup s 2) as the major CCD-bearing allergen in Cupressus sempervirens pollen
International audienceAs IgE glyco‐epitopes, also referred to as cross‐reactive carbohydrate determinants (CCDs), can share significant structural homologies between different plants, they are prone to extensive cross‐reactivity among allergen pollen extracts. Here, cypress pollen allergens, especially a polygalacturonase (PG), were further characterized using double one‐dimensional electrophoresis (D1‐DE). The presence of specific IgE directed against CCDs was investigated by bromelain IgE inhibition and concanavalin A binding assays using sera of cypress pollen‐sensitized patients. Our results showed that IgE reactivity to CCDs in Cupressus sempervirens pollen extracts is mainly related to bromelain‐type epitopes of a newly identified cypress PG. This glycoprotein has been further characterized through an immunoproteomic approach and officially indexed as Cup s 2 by the WHO/IUIS allergen nomenclature. Cup s 2 could thus be associated with the increased prevalence of IgE reactivity to cypress pollen extracts because of CCD interference
Interpretasi Filter Fraser dan Karous-Hjelt pada Data VLF-EM untuk Mengidentifikasi Air Lindi di Area TPA Ngipik
Telah dilakukan penelitian untuk mendeteksi keberadaan air lindi dengan metode VLF dimana pengolahan data yang dilakukan menggunakan Filter Fraser dan Karous-Hjlet. Hasil filter Fraser menghasilkan perpotongan grafik Inphase dan Quadrature yang mana anomali dapat dilihat jika grafik tersebut berpotongan pada saat Inphase negatif dan Quadrature positif sedangkan hasil Filter Karous-Hjelt menghasilkan penampang 2 dimensi dengan parameter rapat arus. Dari hasil penelitian diperoleh keberadaan air lindi ditunjukkan oleh adanya anomali konduktif pada lintasan 1 berada pada posisi 75-125m, 140-160m dan 210-230m, untuk Lintasan 2 berada pada posisi 20-25 m dan 75-135 m, sedangkan Lintasan 3 berada pada posisi 20-50m, 75-170 m dan 210-250 m. Hasil Filter Fraser dan Karous-Hjelt bisa digunakan untuk mendeteksi keberadaan air lindi yang diinterpretasi secara kualitatif dengan adanya anomali yang bersifat konduktif, namun hanya bisa melihat anomali secara lateral (horizontal
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