Colloidal AuNPs show potential as a blood-pool agent for x-ray CT imaging.

Neuronal cell death caused by oxidative stress is common in a variety of neural diseases and can be investigated in detail in cultured HT22 neuronal cells, where the amino acid glutamate at high concentrations causes glutathione depletion by inhibition of the glutamate/cystine antiporter system, intracellular accumulation of reactive oxygen species (ROS) and eventually oxidative stress-induced neuronal cell death. Using this paradigm, we have previously reported that resveratrol (3,5,4'-trans-trihydroxystilbene) protects HT22 neuronal cells from glutamate-induced oxidative stress by inducing heme oxygenase (HO)-1 expression. Piceatannol (3,5,4',3'-trans-trihydroxystilbene), which is a hydroxylated resveratrol analog and one of the resveratrol metabolites, is estimated to exert neuroprotective effect similar to that of resveratrol. The aim of this study, thus, is to determine whether piceatannol, similarly to resveratrol, would protect HT22 neuronal cells from glutamate-induced oxidative stress. Glutamate at high concentrations induced neuronal cell death and ROS formation. Piceatannol reduced glutamate-induced cell death and ROS formation. The observed cytoprotective effect was much higher when HT22 neuronal cells were pretreated with piceatannol for 6 or 12 h prior to glutamate treatment than when pretreated for 0.5 h. Piceatannol also increased HO-1 expression and HO activity via its activation of nuclear factor-E2-related factor 2 (Nrf2). Interestingly, neuroprotective effect of piceatannol was partly (but not completely) abolished by either down-regulation of HO-1 expression or blockage of HO-1 activity. Taken together, our results suggest that piceatannol, similar to resveratrol, is capable of protecting HT22 neuronal cells against glutamate-induced cell death, at least in part, by inducing Nrf2-dependent HO-1 expression.

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Nonvariceal upper gastrointestinal (UGI) bleeding recurs after appropriate endoscopic therapy in 10 % - 15 % of cases. The mortality rate can be as high as 25 % when bleeding recurs, but there is no consensus about the best modality for endoscopic re-treatment. The aim of this study was to evaluate clipping and detachable snaring (CDS) for rescue endoscopic control of nonvariceal UGI hemorrhage. We report a case series of seven patients from a Korean tertiary center who underwent endoscopic hemostasis using the combined method of detachable snares with hemoclips. The success rate of endoscopic hemostasis with CDS was 86 %: six of the seven patients who had experienced primary endoscopic treatment failure or recurrent bleeding after endoscopic hemostasis were treated successfully. In conclusion, rescue endoscopic bleeding control by means of CDS is an option for controlling nonvariceal UGI bleeding when no other method of endoscopic treatment for recurrent bleeding and primary hemostatic failure is possible.

AMP-activated protein kinase (AMPK), a crucial regulator of energy metabolic homeostasis, is suggested to regulate inflammatory responses, but its precise mechanisms are not fully understood. It has been reported that pharmacological activation of AMPK induces heme oxygenase-1 (HO-1) expression. β-Lapachone (BL), a well-known substrate of NAD(P)H:quinone oxidoreductase (NQO1), has been demonstrated to stimulate AMPK activation via NQO1 activation, and to exert anti-inflammatory effects in macrophages. Here we examined whether AMPK activation by BL would be linked to HO-1 expression in RAW264.7 macrophages and whether HO-1 expression could mediate the anti-inflammatory effects of BL. BL treatment induced concentration- and time-dependent AMPK phosphorylation and HO-1 expression. 5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, an AMPK activator, also induced HO-1 expression. In contrast, compound C (CC), an inhibitor of AMPK activation, prevented the increase in BL-induced HO-1 expression. BL pretreatment reduced lipopolysaccharide-induced production of tumor necrosis factor-α, a pro-inflammatory cytokine, and expression of inducible nitric oxide synthase, a pro-inflammatory enzyme. These inhibitory effects BL were almost completely abolished by CC and partly by tin protoporphyrin-IX, a competitive inhibitor of HO-1. Accordingly, the present results indicate that BL induces anti-inflammatory HO-1 expression in macrophages via AMPK activation, providing one of possible mechanisms by which BL can exert anti-inflammatory effects.