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121.
Lu KT Ko MC Chen BY Huang JC Hsieh CW Lee MC Chiou RY Wung BS Peng CH Yang YL 《Journal of agricultural and food chemistry》2008,56(16):6910-6913
Resveratrol is a natural polyphenol and possesses many biological functions such as anti-inflammatory activity and protection against atherosclerosis and myocardial infraction. Parkinson's disease is a common progressive neurodegenerative disease. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is the most useful neurotoxin to induce Parkinsonism. The present study was carried out to elucidate the neuroprotective effect and possible mechanism of resveratrol on MPTP-induced striatal neuron loss. Sixty adult Balb/c mice were divided into four groups: sham operation, MPTP treatment (30 mg/kg, i.p.), MPTP combined with resveratrol administration (20 mg/kg, i.v.), and resveratrol treatment alone. Microdialysis and high-performance liquid chromatography were used to analyze dihydroxybenzoic acid (DHBA) that reflected the hydroxyl radical level. In the present study, we found MPTP chronic administration significantly induced motor coordination impairment in mice. After MPTP administration, the hydroxyl radical levels in substantia nigra were also significantly elevated and animals displayed severe neuronal loss. Resveratrol administration significantly protected mice from MPTP-induced motor coordination impairment, hydroxyl radical overloading, and neuronal loss. Our results demonstrated that resveratrol could elicit neuroprotective effects on MPTP-induced Parkinsonism through free radical scavenging. 相似文献
122.
Chen PH Kuo TY Liu FH Hwang YH Ho MH Wang DM Lai JY Hsieh HJ 《Journal of agricultural and food chemistry》2008,56(19):9015-9021
Several nontoxic dicarboxylic acid solutions (oxalic acid, succinic acid, malic acid, and adipic acid solutions) instead of an acetic acid solution were used as solvents for chitosan dissolution. The amount of free amino groups of the chitosan in the solution decreased due to the ionic cross-linking of the dicarboxylic acids with chitosan. These solutions were used to fabricate porous chitosan membranes. Replacing acetic acid with these dicarboxylic acids for membrane preparation improved the water uptake (by 35% at most), tensile strength (by 110% at most), and elongation capability (by 50% at most) of the membranes. These dicarboxylic acid solutions not only act as solvents but also improve the material properties of the chitosan membranes due to the ionic cross-linking and hydrogen bond formation. In brief, a nontoxic and straightforward cross-linking method has been developed for chitosan material; this method does not result in a brittle product, thus making it better than the use of toxic cross-linking reagents. 相似文献
123.
Ting Fang Hsieh Jenn Wen Huang Tom Hsiang 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(6):571-581
Light, scanning electron and fluorescent microscopy were used to observe the infection process of Botrytis elliptica on leaves of oriental lily (cv. Star Gazer). At 20 °C and 100% relative humidity, conidia germinated on both adaxial and abaxial foliar surfaces, but germ tubes failed to invade epidermal cells on the adaxial surface. On abaxial surfaces, short (< 20 m) swollen germ tube appressoria penetrated through stomatal openings (19%), through the epidermis near guard cells (52%), or directly through epidermal cells (29%). Esterase activity was detected on germ tubes and conidia after 6 h of incubation, and deformation of the cuticle on abaxial surfaces of lily was observed surrounding infection sites. By 3 h after inoculation, almost 70% of the conidia had germinated, but no penetration was observed. At 6 h after inoculation, almost one-third of germinated conidia had penetrated epidermal cells, and water-soaked lesions were associated with 20% of the penetrations. By 9 h after inoculation, approximately 60% of the germinated conidia had penetrated plant tissues, and water-soaked lesions were associated with 60% of the infections. Fluorescent microscopy with a specific fungal stain allowed assessment of successful infection and visualization of sub-epidermal hyphae. We conclude that penetration of abaxial foliar surfaces of oriental lilies by B. elliptica occurs via short swollen germ tube appressoria mostly near stomata. 相似文献
124.
Herpesviruses can establish a persistent infection in the cells and tissues of their natural hosts and thus may produce diseases due to cytolytic infections. We have isolated a herpesvirus from a bovine vascular endothelial cell culture after continuous subculturing. Typical cytopathic changes were observed in bovine endothelial cell cultures 2 days after inoculation of the virus. The virus had an icosahedral nucleocapsid of 100-150 nm in diameter and an envelope. The sequences of some DNA fragments of the virus were highly homologous to those of the bovine herpesvirus type 4 (BHV-4) strains. The DNA restriction maps of the virus and the reference strains of BHV-4, DN 599 and Movar 33/63 were very similar but not identical. Therefore, the newly isolated virus has been designated Taiwan strain. The presence of BHV-4 DNA in apparently normal bovine endothelial cell cultures was shown by Southern blot hybridization with the BamHI fragment of the newly isolated BHV-4 and was further confirmed by digestion of the DNA with BamHI plus AccI. In conclusion, we have demonstrated that BHV-4 persisted in the bovine endothelial cell cultures and continuous subcultures could lead to the production of infectious viral particles. 相似文献
125.
126.
Molinate, a selective herbicide, is used for the control of annual and perennial weeds in rice paddy fields. This study was designed to assess the basis of the selective action of molinate between a susceptible broadleaf crop, tobacco, and a resistant graminaceous plant, rice. Experiments were conducted comparing plant growth under different concentrations of molinate, determining the absorption and translocation of the herbicide in the plant and identifying the metabolites in suspension cells. Rice showed greater tolerance to molinate than tobacco. Leaves of tobacco showed retarded and distorted growth at 10 mg liter-1 of molinate 14 days after treatment, but rice leaves were unaffected at this concentration. Higher concentrations of molinate accumulating in the root of tobacco seedlings may inhibit root development and represent a significant factor in the herbicide's selective action. Seven and eight metabolites were found in tobacco and rice cells, respectively, with molinate sulfoxide and molinate sulfone present in both species. © 1998 SCI 相似文献
127.
128.
S A Barker T McDowell B Charkhian L C Hsieh C R Short 《Journal of the Association of Official Analytical Chemists》1990,73(1):22-25
Methodology for the analysis of 8 benzimidazoles as residues in bovine liver is reported. Spiked tissues were extracted by homogenization in saline and ammonium hydroxide and blending with diatomaceous earth. This matrix was packed into a column, and the benzimidazoles were eluted with ethyl acetate. After the sample was further purified, benzimidazoles were separated and quantitated by liquid chromatography with ultraviolet detection (290 nm). Liver tissue samples obtained from cattle which had undergone a drug depletion study of fenbendazole administered per os were analyzed using these methods. The results of these analyses and the application of this approach to multiresidue analysis of drugs in animal tissues are discussed. 相似文献
129.
Extracts were prepared from Chinese chive (Allium tuberosum), cinnamon (Cinnamomum cassia), and corni fructus (Cornus officinalis) and used to evaluate their antimicrobial activity on common foodborne microorganisms, alone and in combination. The mixed extract, consisting of three extracts in equal volumes, showed an entire antimicrobial spectrum and had excellent stability to heat, pH, and storage. The mixed extract exhibited better inhibition on growth of Escherichia coli than potassium sorbate at 2-5 mg/mL. The mixed extract inhibited the growth of Pichia membranaefaciens at levels as low as 2 mg/mL. When the mixed extract was used in foods, the expected antimicrobial effect in orange juice, pork, and milk was observed. After gel filtration chromatography, each extract was partially purified into fractions, and one fraction in each extract showed enhanced antimicrobial activity. Overall, the mixed extract was of promising potential for incorporation into various food products for which a natural antimicrobial additive is desired. 相似文献
130.
A surfactant-coated lipase (SCL) prepared by mixing Candida rugosa lipase with emulsifier in ethanol was used to hydrolyze tuna oil in a two-phase aqueous-organic system. Both enzyme (SCL) and substrate (tuna oil) were soluble in the organic phase, and the hydrolysis could occur with water molecules from the aqueous phase. This hydrolysis could promptly proceed compared to that catalyzed by native lipases which only occurred at the interface between the two phases. Michaelis-Menten kinetics in the two-phase reactions showed that the K(m) value of the SCL was half that of the native lipase, while the maximum velocity (V(max)) was 11.5 times higher. The hydrolysis method resulted in enrichment of n-3 polyunsaturated fatty acid (n-3 PUFA) content in glyceride mixtures from 26.4% to 49.8% and DHA from 19.1% to 38.9%. The SCL acted as an efficient hydrolytic catalyst for tuna oil. 相似文献