Antiproliferative Activity of Fucan Nanogel     

Nednaldo Dantas-Santos  Jailma Almeida-Lima  Arthur Anthunes Jacome Vidal  Dayanne Lopes Gomes  Ruth Medeiros Oliveira  Silvia Santos Pedrosa  Paula Pereira  Francisco Miguel Gama  Hugo Alexandre Oliveira Rocha 《Marine drugs》2012,10(9):2002-2022

Sulfated fucans comprise families of polydisperse natural polysaccharides based on sulfated L-fucose. Our aim was to investigate whether fucan nanogel induces cell-specific responses. To that end, a non toxic fucan extracted from Spatoglossum schröederi was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution with hydrophobic chains was close to 100%, as estimated by elemental analysis. SNFfuc in aqueous media had a mean diameter of 123 nm and zeta potential of −38.3 ± 0.74 mV, as measured by dynamic light scattering. Nanoparticles conserved their size for up to 70 days. SNFuc cytotoxicity was determined using the MTT assay after culturing different cell lines for 24 h. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0%–43.7% at nanogel concentrations of 0.05–0.5 mg/mL and rabbit aorta endothelial cells (RAEC) non-tumor cell line proliferation displayed inhibition of 8.0%–22.0%. On the other hand, nanogel improved Chinese hamster ovary (CHO) and monocyte macrophage cell (RAW) non-tumor cell line proliferation in the same concentration range. The antiproliferative effect against tumor cells was also confirmed using the BrdU test. Flow cytometric analysis revealed that the fucan nanogel inhibited 786 cell proliferation through caspase and caspase-independent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle.  相似文献   

Chemical and microbiological soil properties in organic and conventional management systems of Coffea arabica L.     

Romildo Rocha Azevedo Junior  Janaina Biral dos Santos  Dilmar Baretta  Alessandro Coutinho Ramos  Arthur Prudêncio de Araujo Pereira  Elke Jurandy Bran Nogueira Cardoso 《Journal of plant nutrition》2017,40(14):2076-2086

The goal of this study was to evaluate the effect of organic (OS) and conventional (CS) farming of Arabica coffee on chemical and microbiological soil properties and to identify which attributes correlate and/or contribute to distinguishing these two management systems. We collected soil samples on a 100 × 100 m² grid in both, the OS and CS, in winter and summer and submitted chemical and microbiological properties to univariate and multivariate analyses (canonical discriminant analysis – CDA – and redundancy analysis – RDA). The best indicators to discriminate OS and CS were chemical and microbiological properties, as the elements calcium (Ca) and boron (B), besides microbial biomass carbon (MBC), metabolic quotient (qCO₂), acid phosphatase (ACP), and alkaline phosphatase (ALP). The RDA showed that, regardless of the season, MBC and ACP correlated with nitrogen (N), sulfur (S) and organic matter (OM), whereas basal respiration (C-CO₂) and ACP correlated with qCO₂ and with magnesium (Mg), calcium (Ca), phosphorus (P), potassium (K) and pH.  相似文献   

Disposition of the anti‐ulcer medications ranitidine,cimetidine, and omeprazole following administration of multiple doses to exercised Thoroughbred horses          下载免费PDF全文

H. K. Knych  S. D. Stanley  R. M. Arthur  D. S. McKemie 《Journal of veterinary pharmacology and therapeutics》2017,40(1):92-96

The use of anti‐ulcer medications, such as cimetidine, ranitidine, and omeprazole, is common in performance horses. The use of these drugs is regulated in performance horses, and as such a withdrawal time is necessary prior to competition to avoid a medication violation. To the authors' knowledge, there are no reports in the literature describing repeated oral administrations of these drugs in the horse to determine a regulatory threshold and related withdrawal time recommendations. Therefore, the objective of the current study was to describe the disposition and elimination pharmacokinetics of these anti‐ulcer medications following oral administration to provide data upon which appropriate regulatory recommendations can be established. Nine exercised Thoroughbred horses were administered 20 mg/kg BID of cimetidine or 8 mg/kg BID of ranitidine, both for seven doses or 2.28 g of omeprazole SID for four doses. Blood samples were collected, serum drug concentrations were determined, and elimination pharmacokinetic parameters were calculated. The serum elimination half‐life was 7.05 ± 1.02, 7.43 ± 0.851 and 3.94 ± 1.04 h for cimetidine, ranitidine, and omeprazole, respectively. Serum cimetidine and ranitidine concentrations were above the LOQ and omeprazole and omeprazole sulfide below the LOQ in all horses studied upon termination of sample collection.  相似文献   

Selective control of mite and collembolan pests of pastures and grain crops in Australia     

Paul A. Umina  Aston L. Arthur  Stuart A. McColl  Ary A. Hoffmann  John M.K. Roberts 《Crop Protection》2010

Control of invertebrate pests in broad-acre agriculture largely relies on the application of broad-spectrum pesticides, however resistance problems and environmental concerns are driving a search for alternatives including more selective products. Here we explore the feasibility of using novel chemical groupings in the control of problematic pests that attack germinating pastures and grain crops in Australia. A modified laboratory bioassay is described for testing the response of several invertebrate pests to pesticides that have contact and systemic/translaminar properties. Two contact pesticides (fenitrothion and gamma-cyhalothrin) and three pesticides with strong systemic/translaminar properties (lambda-cyhalothrin, abamectin and diafenthiuron) showed promise for control of the collembolan Sminthurus viridis and four mite pests (Halotydeus destructor, Balaustium medicagoense, Penthaleus falcatus and Bryobia sp.). No single pesticide emerged as the most efficacious against all these pests, highlighting the need for correct pest identification before making control recommendations. Incorporating these new chemical options into pest control programs may help to control emerging pests and counter pesticide resistance issues. Selective pesticides in particular are likely to be compatible with integrated control programs that promote the establishment and maintenance of beneficial natural enemies.  相似文献   

Fishing for data in the Ross Sea     

Blight LK  Ainley DG  Ackley SF  Ballard G  Ballerini T  Brownell RL  Cheng CH  Chiantore M  Costa D  Coulter MC  Dayton P  Devries AL  Dunbar R  Earle S  Eastman JT  Emslie SD  Evans CW  Garrott RA  Kim S  Kooyman G  Lescroël A  Lizotte M  Massaro M  Olmastroni S  Ponganis PJ  Russell J  Siniff DB  Smith WO  Stewart BS  Stirling I  Willis J  Wilson P  Woehler EJ 《Science (New York, N.Y.)》2010,330(6009):1316

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Politics,Policy, Settlers,and Consequences for Canadian Prairie Grasslands: A Range Management Perspective     

Arthur Bailey  Michael P. Schellenberg  Duane McCartney  Patricia Bailey 《Herpetological Monographs》2010,32(5):17-25

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Solid-state selective (13)C excitation and spin diffusion NMR to resolve spatial dimensions in plant cell walls     

Foston M  Katahira R  Gjersing E  Davis MF  Ragauskas AJ 《Journal of agricultural and food chemistry》2012,60(6):1419-1427

The average spatial dimensions between major biopolymers within the plant cell wall can be resolved using a solid-state NMR technique referred to as a (13)C cross-polarization (CP) SELDOM (selectively by destruction of magnetization) with a mixing time delay for spin diffusion. Selective excitation of specific aromatic lignin carbons indicates that lignin is in close proximity to hemicellulose followed by amorphous and finally crystalline cellulose. (13)C spin diffusion time constants (T(SD)) were extracted using a two-site spin diffusion theory developed for (13)C nuclei under magic angle spinning (MAS) conditions. These time constants were then used to calculate an average lower-limit spin diffusion length between chemical groups within the plant cell wall. The results on untreated (13)C enriched corn stover stem reveal that the lignin carbons are, on average, located at distances ～0.7-2.0 nm from the carbons in hemicellulose and cellulose, whereas the pretreated material had larger separations.  相似文献   

Comparison of the effectiveness of different methods of screening for bacterial soft rot resistance of potato tubers     

Ewa Łojkowska  Arthur Kelman 《American Journal of Potato Research》1994,71(2):99-113

Tubers from eight potato cultivars (cvs) grown at two different locations in Wisconsin were tested for bacterial soft rot resistance using different inoculation techniques. The procedures included 1) point inoculations of tubers with different inoculum levels followed by incubation in ambient or low oxygen condtions, 2) inoculation of mechanically bruised tubers followed by incubation in a mist chamber, and 3) a standard slice inoculation method. The point titration test followed by incubation in dew chamber and the mist chamber-bruise test showed similar patterns of resistance for cultivars that were used in these experiments. These two methods are considered to be effective for screening potato tubers for bacterial soft rot resistance. Point titration methods are very useful if only limited numbers of tubers are available. The mist chamber-bruise test is simpler than the other procedures; however, to obtain reproducible results large numbers of tubers are required. Because of the great variability of the results obtained in inoculation of slices, the reliability of this approach can be questioned as a standardized method for evaluation of resistance. Tubers of somatic hybrids ofS. brevidens andS. tuberosum and their sexual progeny were significantly more resistant to bacterial soft rot than tubers of moderately resistant cultivars when evaluated by each of the assay procedures.  相似文献   

Row fumigation with Vorlex for control of a meadow nematode (Pratlylenchus penetrans) in potatoes     

Arthur Hawkins  P. M. Miller 《American Journal of Potato Research》1971,48(2):64-68

Row fumigation with Vorlex at 3 and 7 gallons per acre was applied for meadow nematode (Pratylenchus penetrans) control in potatoes. The material was applied 3 weeks before planting using one chisel per row at a depth of 8″, and ridged. The treatments resulted in a reduction in population ofP. penetrans in the soil and in the potato roots. On a soil with a relatively high population of meadow nematodes, row application of Vorlex at 3 and 7 gal per acre resulted in a yield increase of 10 and 14% respectively, and a lower incidence of tubers with vascular discoloration. By early October as many nematodes were present in treated rows as in untreated rows. Row fumigation is of value for only one potato crop.  相似文献   

The effect of different combinations of soil moisture and nitrogen levels on early plant development and tuber set of the potato     

George A. Bradley  Arthur J. Pratt 《American Journal of Potato Research》1955,32(7):254-258

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