Effect of elevated nitrogen levels on endogenous gibberellin and jasmonic acid contents of three rice (Oryza sativa L.) cultivars

Three rice (Oryza sativa L.) cultivars ( cv. Daesanbyeo, cv. Dongjinbyeo, cv. Junambyeo) were analyzed for endogenous gibberellin (GA) and jasmonic acid (JA) contents and their changes in response to elevated nitrogen (N) levels. The N fertilizer was applied in the form of urea [(NH₂)₂CO] at three rates (0, 36.8, 73.6 kg N ha^–1). Plant growth (height and dry weight) was enhanced by the first N rate but not further enhanced by the highest rate. The endogenous GA contents were analyzed through high‐performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry–selected ion monitoring (GC‐MS‐SIM) while that of JA with GC‐MS‐SIM. They were analyzed one week after N application and were significantly increased with elevated N levels in all rice cultivars. The bioactive GA₁ markedly increased, but its concentration differed in different rice cultivars. Similar fluctuations were observed for endogenous GA₈, GA₁₂, GA₁₉, GA₂₀, and GA₅₃ in response to elevated N levels, showing that the rates of biosynthesis of GAs were differently affected by elevated N levels within different rice cultivars. The level of GA₂₀, a precursor of GA₁ biosynthesis, was not significantly increased, though GA₁₉, a precursor of GA₂₀, was found to be the most abundant GA type in all rice cultivars. Jasmonic acid content in the plants increased with the basic urea application (36.8 kg N ha^–1), but significantly decreased with the double urea level (73.6 kg N ha^–1). The results demonstrate that GA and JA are differentially affected in response to elevated N application in rice.     

Quantification of endogenous gibberellins in two flax (Linum usitatissimum L.) cultivars during seed development

Eight gibberellins (GAs) were identified and quantified in extracts of seed of the flax, Linum usitatissimum L. cv. Hwanamama, Hwabaekama by GC-MS-SIM and Kovats retention indices. Four of these gibberellins are members of the early-C13-hydroxylation pathway (GA₅₃, GA₁₉, GA₂₀, and GA₁), and four are members of the non-C13-hydroxylation pathway (GA₁₂, GA₂₄, GA₉, and GA₄). Of these eight gibberellins, GA₂₄ was more abundant in yellow-seeded flax (cv. Hwanamama) than in brown-seeded flax (cv. Hwabaekama), whereas GA₉ was 8.3-fold more abundant in brown-seeded flax (cv. Hwabaekama) than in yellow-seeded flax (cv. Hwanamama). In both flax cultivars, non-C13-hydroxylation pathway was the main route leading to endogenous accumulation of GA₄ in the seed.     

Lectin histochemistry for glycoconjugates in the small intestines of piglets naturally infected with Isospora suis

Composition of glycoconjugates was examined in small intestines naturally infected with Isospora suis in preweaned pigs by use of 21 biotinylated-labeled lectins with avidin-biotin-peroxidase complex method. As compared with control pig, staining of 18 lectins altered in jejunal villus brush border and goblet cells of pigs naturally infected with I. suis. These results indicate that I. suis infection alters carbohydrate residues on the jejunal intestines.     

Lectin histochemistry of Peyer's patches in the porcine ileum

Lectin staining pattern in Peyer's patches of porcine ileum was studied using twenty one biotinylated-labeled lectins as cell markers which were visualized with avidin-biotin-peroxidase complex method (ABC). WGA appears to be a selective marker for tingible body macrophages in the porcine germinal centers. ConA may be a positive marker for the lymphoid tissues, whereas 9 lectins (DBA, SBA, SJA, s-WGA, PNA, ECL, UEA-I, PHA-E, and PHA-L) may be negative markers for the lymphoid tissues in all areas.     

Cellular uptake of magnetic nanoparticle is mediated through energy-dependent endocytosis in A549 cells

Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO₂(RITC)s] were synthesized. For future application of the MNP@SiO₂(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism.     

添加蛋氨酸壳聚糖酵母形式的螯合铜对肉仔鸡生产性能的影响

试验研究了添加蛋氨酸螯合铜(Met-Cu)、壳聚糖螯合铜(Chitosan-Cu)、酵母螯合铜(Yeast-Cu)对肉仔鸡生产性能、营养物质消化率、血清IGg水平、嗉囊腐蚀程度、肝脏和排泄物中铜(Cu)含量以及肌肉和血清中总胆固醇的水平的影响。240只肉仔鸡(Ross208)平均分配到4个处理组中:对照组、Met-Cu组、Chitosan-Cu组、Yeast-Cu组。3个螯合铜试验组日粮铜含量均为100mg/kg。每个处理组中设6个重复,每个重复10只鸡(5只公鸡 5只母鸡)。试验结果表明,螯合铜试验组增重和采食量均高于对照组。Met-Cu组增重显著高于对照组(P<0.05),Yeast-Cu组采食量显著高于对照组(P<0.05)。各处理组料重比明显不同,由低到高依次为Met-Cu组、对照组、Chitosan-Cu组和Yeast-Cu组。各组间干物质利用率差异显著(P<0.05),螯合铜的试验组干物质利用率显著高于对照组,其中Chitosan-Cu组最高。添加螯合铜提高了嗉囊腐蚀系数,Met-Cu组肝脏铜含量最高。添加螯合铜降低了胸肌和血清中总胆固醇水平,而提高了血清高密度脂蛋白(HDL)水平。试验结果表明,在肉仔鸡日粮中以螯合铜形式添加铜100mg/kg,可以提高增重、采食量和干物质利用率,其中Met-Cu效果最好。     

Flavonol glycosides with free radical-scavenging activity of Saururus chinensis

An activity-guided fractionation procedure was used to identify the antioxidative components of the aerial parts of Saururus chinensis. The antioxidant activity was investigated with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical- and superoxide anion-scavenging assays. Three active compounds (flavonol glycosides) were identified.     

Near‐Infrared Spectroscopy for Determination of Protein and Amylose in Rice Flour Through Use of Derivatives

The use of the derivative method for near‐infrared (NIR) calibration was investigated to determine protein and amylose content in rice flour. Samples for two years, 1996 and 1999, were combined to give a wide range of the constituents for development of the calibration model. The NIR spectral data were transformed with Savitzky‐Golay derivative with multiplicative scatter correction. To develop the best derivative models, the polynomial fits (quadratic, cubic, and quartic), convolution intervals (3–11 points for protein, 3–17 points for amylose), and derivative orders (1st derivative D1; 2nd derivative D2) were investigated. For the protein analysis, all polynomial fits with 3–11 points were acceptable to develop both the D1 and D2 models. However, the three‐point quadratic and five‐point quartic fits were not acceptable for the D1 model, and the three‐point quadratic fit was not acceptable for D2. For the amylose analysis, the D1 model produced generally better results than D2. Higher convolution intervals were required for the D2 model, whereas the D1 model was not affected by convolution intervals. A quadratic (or cubic) fit with 17‐point convolution interval was acceptable for the amylose D2 model, and the quadratic fit with 5–11 points and cubic (or quartic) fit with 7–17 points were suitable for the D1 model. Based on the standard error of cross‐validation (SECV), the calibration models developed using data for two years resulted in good precision with an SECV of 0.23% for protein using four factors and an SECV of 1.0% for amylose using 10 factors.     

Antibacterial effect of Dryopteris crassirhizoma against methicillin-resistant Staphylococcus aureus

Methanol extract and its fractions (hexane, EtOAc, n-BuOH, and H2O) of Dryopteris crassirhizoma were investigated for antibacterial activity against methicillin-resistant Staphylococcus aureus. The hexane fraction showed a good antibacterial activity against all tested strains.