Superoxide anion can modulate vascular smooth muscle tone and is potentially involved in diabetic vascular complications. The present study was undertaken to characterize both vascular production and the enzymatic source of superoxide anion in type 2 diabetic rats. In the thoracic aorta of OLETF rats, endotheliumdependent relaxation was markedly attenuated compared with that of control (LETO) rats in association with a significant increase in superoxide production (2,421.39 ؎ 407.01 nmol ⅐ min -1 ⅐ mg -1 ). The increased production of superoxide anion was significantly attenuated by diphenyleneiodonium (DPI; 10 mol/l), an inhibitor of NAD(P)H oxidase. The production of superoxide anion in response to NADH as a substrate was markedly increased in the vascular homogenates, but NADPH, arachidonic acid, xanthine, and succinate produced only small increases in chemiluminescence. In line with these results, studies using various enzyme inhibitors, such as DPI, allopurinol, rotenone, N G -monomethyl-L-arginine, and indomethacin, suggest that the predominant source of superoxide anion in vascular particulate fraction is NADH-dependent membranebound oxidase. Furthermore, the expression of p22phox, a major component of vascular NAD(P)H oxidase, was markedly increased in the aorta from OLETF rats compared with that of LETO rats. These findings suggest that upregulated expression of p22phox mRNA and enhanced NADH oxidase activity contribute to the impaired endothelium-dependent vasodilation in OLETF rats. Diabetes 51:522-527, 2002

Recently, inkjet printing technology has become crucial in many industrial fabrication fields mainly due to its advantages of noncontact and fast pattern generation. In this paper, we investigate an electrostatic field induced inkjet printing system, which is based on an electrohydrodynamic process, for drop-on-demand jetting. In order to locate the optimal jetting conditions, we tested jetting performance for various bias voltages and pulse signals. To investigate the characteristics of drop-on-demand operation and micropatterning, we used conductive silver ink and examined the drops and lines patterned on a substrate.

A droplet-based (digital) microfluidics platform has been developed to prepare and purify protein samples for measurement by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Liquid droplets are moved in air by sequentially applying an electric potential to an array of electrodes patterned beneath a hydrophobic dielectric layer. We show that a complete integrated sequence of protein processing steps can be performed on this platform, including disulfide reduction, alkylation, and enzymatic digestion, followed by cocrystallization with a MALDI matrix and analysis of the sample in situ by MALDI-MS. Proteins carbonic anhydrase, cytochrome c, and ubiquitin were used to demonstrate the digestion and postdigestion steps; insulin, serum albumin, and lysozyme were used to illustrate the complete sequence of protein processing steps available with the platform. Several functional improvements in the platform are reported, notably, the incorporation of acetonitrile in the protein droplets to facilitate movement, and patterning the device surfaces to optimize sample crystallization. The method is fast, simple, repeatable, and results in lower reagent consumption and sample loss than conventional techniques for proteomics sample preparation.

PurposeMuscles play an important role in energy metabolism. Several studies have investigated the association between muscle mass and metabolic syndrome (MetS), reporting conflicting results. However, studies concerning the association between muscle strength and MetS are limited. We aimed to investigate the association between relative handgrip strength (HGS) and MetS in Korean adults.Participants and methodsWe analyzed data from 5,014 Korean adults aged ≥20 years (2,472 men and 2,542 women) who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) VI (2014–2015).ResultsThe increasing quartiles of relative HGS (defined as the sum of both hands’ HGS divided by body mass index) were inversely associated with the risk of MetS in both men and women (OR, 0.37; 95% CI, 0.30–0.45, vs OR, 0.19; 95% CI, 0.14–0.27, respectively) after multivariable adjustment for age, region of residence, smoking status, heavy alcohol consumption, regular exercise, family income, and education level. On multivariable logistic regression analyses, participants with the highest relative HGS had a significant decrease in relative risk of MetS, compared with those with the lowest relative HGS. The multivariable-adjusted ORs (with 95% CIs) for MetS in quartiles 1, 2, 3, and 4 were 1.00, 0.72 (0.55–0.94), 0.34 (0.26–0.46), and 0.22 (0.15–0.32) in men and 1.00, 0.50 (0.36–0.68), 0.26 (0.17–0.40), and 0.16 (0.09–0.27) in women, respectively.ConclusionRelative HGS showed a highly significant inverse association with the risk of MetS in Korean adults, and it can be a novel biomarker for assessing the risk of MetS.