Abbreviations used: BBB, blood-brain barrier; Gd-DTPA, gadolinium-diethylenetriamine pentaacetic acid; MCAO, middle cerebral artery occlusion; MMP, matrix metalloproteinase; MRI, magnetic resonance imaging; NBO, normobaric hyperoxia; PBS, phosphate-buffered saline; TTC, 2,3,5-triphenyltetrazolium chloride. AbstractMatrix metalloproteinase-9 (MMP-9) and NADPH oxidase contribute to blood-brain barrier (BBB) disruption after ischemic stroke. We have previously shown that normobaric hyperoxia (NBO) treatment reduces MMP-9 and oxygen free radical generation in ischemic brain. In this study, we tested the hypothesis that NBO protects the BBB through inhibiting NADPH oxidase-mediated MMP-9 induction in transient focal cerebral ischemia. Male Sprague-Dawley rats (n = 69) were given NBO (95% O 2 ) or normoxia (21% O 2 ) during 90-min filament occlusion of the middle cerebral artery. Cerebral microvessels were isolated for analyzing MMP-9 and NADPH oxidase. BBB damage was non-invasively quantified with magnetic resonance imaging. In normoxic rats, both NADPH oxidase catalytic subunit gp91 phox and MMP-9 expression were up-regulated in ischemic hemispheric microvessels after 90-min middle cerebral artery occlusion with 22.5 h reperfusion. Inhibition of NADPH oxidase with apocynin reduced the MMP-9 increase, indicating a causal link between NADPH oxidase-derived superoxide and MMP-9 induction. NBO treatment inhibited gp91 phox expression, NADPH oxidase activity, and MMP-9 induction, which led to significantly less BBB damage and brain edema in the ischemic brain. These results suggest that gp91 phox containing NADPH oxidase plays an important role in MMP-9 induction in ischemic BBB microvasculature, and that NBO treatment may attenuate MMP-9 induction and brain edema through inhibiting NADPH oxidase after transient cerebral ischemia.

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A high-performance anion exchange chromatographic method was adapted for the quantitative determination of phytic acid and inositol pentakisphosphate isomers (excluding enantiomers) in foods. Because of the cost and limited availability of inositol phosphate standards, a phytic acid sodium salt standard was used for the calculation of an average relative response factor for the quantification of inositol pentakisphosphate isomers, and the purity of phytic acid sodium salt standard was also accurately established. The detection limits (S/N = 3) for phytic acid and inositol pentakisphosphates were in the range of 1.5-3.4 microM (0.1-0.2 microg/100 microL). This method has been successfully applied to the determination of phytic acid and inositol pentakisphosphates in a variety of beans and nuts after extraction with 0.5 M HCl and cleanup with solid phase extraction cartridges. The results demonstrated that there was a strong correlation between either the phytic acid content or the total content of phytic acid together with inositol pentakisphosphates and the total dietary fiber content in the group of all raw dry beans and in the group of raw dry black beans but not in the group of raw dry red kidney beans, which was probably due to the insufficient number of the raw dry red kidney bean samples.

A close correllation between molecular-level interactions and macroscopic characteristics of polymer networks exists. The characteristics of the polymeric hydrogels assembled from β-cyclodextrin (β-CD) and adamantyl (AD) substituted poly(acrylate)s can be tailored through selective host-guest complexation between β-CD and AD substituents and their tethers. Dominantly, steric effects and competitive intra- and intermolecular host-guest complexation are found to control poly(acrylate) isomeric inter-strand linkage in polymer network formation. This understanding of the factors involved in polymeric hydrogel formation points the way towards the construction of increasingly sophisticated biocompatible materials.

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Gastric cancer is a common kind of malignant tumour that seriously affects people's health. 1 According to the data from the World health Organization (WHO), in contrast to the United States, Australia and New Zealand, China, Japan and Chile have higher incidence areas of gastric cancer. 2 In China, gastric cancer is the second cause of cancer-related deaths, with 679 000 new cases and 498 000 deaths. 3 Gastric cancer is predisposed to occur in individuals aged between 50 and 70 years. However, in recent

Plasma immersion ion implantation of the inner surface of a finite-length small cylindrical tube with a coaxial, grounded auxiliary electrode is modeled using a two-dimensional particle-in-cell model. Various ratios of tube lengths against tube diameters are simulated. It is found that a peak in total accumulated dose is observed near the ends of the tube. Provided that it is long enough, the ions that come from the outside of the tube cannot pass through the middle-plane. That is, the tube can be divided conceptually into an "end" and a "middle" region, while the middle remains empty and all the flux goes to the end. In other words, a one-dimensional model can be applied to the "middle" region. The simulation results including the enhanced ion dose agrees with our experimental data.