Accumulation of unfolded proteins in the endoplasmic reticulum (ER) causes ER overload, resulting in ER stress. To cope with ER stress, mammalian cells trigger a specific response known as the unfolded protein response (UPR). Although recent studies have indicated cross-talk between ER stress and oxidative stress, the mechanistic link is not fully understood. By using murine fibrosarcoma L929 cells, in which tumor necrosis factor (TNF) ␣ induces accumulation of reactive oxygen species (ROS) and cell death, we show that TNF␣ induces the UPR in a ROS-dependent fashion. In contrast to TNF␣, oxidative stresses by H 2 O 2 or arsenite only induce eukaroytic initiation factor 2␣ phosphorylation, but not activation of PERK-or IRE1-dependent pathways, indicating the specificity of downstream signaling induced by various oxidative stresses. Conversely, the UPR induced by tunicamycin substantially suppresses TNF␣-induced ROS accumulation and cell death by inhibiting reduction of cellular glutathione levels. Collectively, some, but not all, oxidative stresses induce the UPR, and pre-emptive UPR counteracts TNF␣-induced ROS accumulation.Newly synthesized secretory and membrane-associated proteins are correctly folded and assembled in the endoplasmic reticulum (ER). 2Once ER function is perturbed by various pathological conditions, newly synthesized unfolded proteins accumulate in the ER, resulting in ER stress. To cope with accumulated unfolded ER proteins, mammalian cells trigger a specific response termed the unfolded protein response (UPR) (1-3). There are three distinct signaling pathways that are triggered in response to ER stress, mediated by PERK, ATF6, and IRE1. Under non-pathological conditions, all three components associate with the abundant lumenal chaperon Bip (also known as glucose-regulated protein 78) and this interaction keeps these signaling molecules in an inactive state (4, 5). Once unfolded proteins accumulate in the ER, Bip preferentially associates with the unfolded proteins instead of PERK, ATF6, and IRE1, resulting in activation of their downstream signaling molecules. PERK is an ER-resident serine/threonine protein kinase that phosphorylates the ␣ subunit of eukaryotic translation initiation factor 2 (eIF2␣) (6). Phosphorylation of eIF2␣ subsequently inhibits protein synthesis to prevent further influx of nascent proteins into an already saturated ER lumen. Paradoxically, eIF2␣ phosphorylation induces translation of a transcription factor ATF4 and subsequent expression of the ATF4 target genes, GADD34 and CHOP (7). The second signaling pathway is mediated by the basic leucine zipper-type transcription factor, ATF6. ATF6 is synthesized as a type II transmembrane precursor protein with a molecular mass with 90 kDa (p90 ATF6), and anchored to the ER membrane where it is retained by Bip. In response to ER stress, ATF6 is released from Bip and transported to the Golgi complex (8), where ATF6 undergoes sequential cleavages by two proteases, S1P and S2P (9). The processed form of ATF6 (p50ATF6) translocate...

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We recently reported that Wuzhi tablet (WZ; Schisandra sphenanthera extract) can inhibit P-glycoprotein (P-gp)-mediated efflux and CYP3A-mediated metabolism of tacrolimus (FK506) and thus increase the blood concentrations of FK506. Major active lignans of WZ include schisandrin A, schisandrin B, schisandrin C, schisandrol A, schisandrol B, and schisantherin A. Whether and how these six lignans affect the pharmacokinetics of FK506 remains unclear. Therefore, this study aimed to investigate the effects of these lignans on the first-pass absorption and metabolism of FK506 and the involved mechanisms in vitro and in vivo. The results showed that whole-blood concentrations of FK506 were increased to different degrees following coadministration of the six lignans, respectively. Schisandrol B showed the strongest effect on the increase of the area under the concentration-time curve, the oral bioavailability, the gut processes affecting availability, and the hepatic availability of FK506. The reduction of intestinal first-pass effect contributed most to the increase in oral bioavailability of FK506 when coadministered with schisandrol B. In vitro transport experiment showed that schisandrin A, schisandrin B, and schisandrol B inhibited P-gp-mediated efflux of FK506. In vitro metabolism study showed that the inhibitory effect of these six lignans on FK506 metabolism was dose-dependent. In conclusion, the exposure of FK506 in rats was increased when coadministered with these lignans, and schisandrol B showed the strongest effect. Lignans of WZ inhibited P-gp-mediated efflux and CYP3A-mediated metabolism of FK506, and the reduction of intestinal first-pass affected by the lignans was the major cause of the increased FK506 oral bioavailability.

Rationale: Early diagnosis and treatment of tuberculous meningitis saves lives, but current laboratory diagnostic tests lack sensitivity.Objectives: We investigated whether the detection of intracellular bacteria by a modified Ziehl-Neelsen stain and early secretory antigen target (ESAT)-6 in cerebrospinal fluid leukocytes improves tuberculous meningitis diagnosis.Methods: Cerebrospinal fluid specimens from patients with suspected tuberculous meningitis were stained by conventional Ziehl-Neelsen stain, a modified Ziehl-Neelsen stain involving cytospin slides with Triton processing, and an ESAT-6 immunocytochemical stain. Acid-fast bacteria and ESAT-6-expressing leukocytes were detected by microscopy. All tests were performed prospectively in a central laboratory by experienced technicians masked to the patients' final diagnosis.Measurements and Main Results: Two hundred and eighty patients with suspected tuberculous meningitis were enrolled.Thirty-seven had Mycobacterium tuberculosis cultured from cerebrospinal fluid; 40 had a microbiologically confirmed alternative diagnosis; the rest had probable or possible tuberculous meningitis according to published criteria. Against a clinical diagnostic gold standard the sensitivity of conventional Ziehl-Neelsen stain was 3.3% (95% confidence interval, 1.6-6.7%), compared with 82.9% (95% confidence interval, 77.4-87.3%) for modified Ziehl-Neelsen stain and 75.1% (95% confidence interval, 68.8-80.6%) for ESAT-6 immunostain. Intracellular bacteria were seen in 87.8% of the slides positive by the modified Ziehl-Neelsen stain. The specificity of modified Ziehl-Neelsen and ESAT-6 stain was 85.0% (95% confidence interval, 69.4-93.8%) and 90.0% (95% confidence interval, 75.4-96.7%), respectively.Conclusions: Enhanced bacterial detection by simple modification of the Ziehl-Neelsen stain and an ESAT-6 intracellular stain improve the laboratory diagnosis of tuberculous meningitis.

A silver nanoplate aggregation based plasmonic absorber layer with excellent light confinement and photothermic harvesting performance in the broadband range.