Development of a method for oral administration of hydrophobic substances to Caenorhabditis elegans: pro-longevity effects of oral supplementation with lipid-soluble antioxidants.

Methods for quantitative oral administration of various substances to Caenorhabditis elegans are needed. Previously, we succeeded in oral administration of hydrophilic substances using liposomes. However, an adequate system for delivery of hydrophobic chemicals was not available. In this study, we developed a method for oral administration of lipid-soluble substances to C. elegans. γ-cyclodextrin (γCD), which delivers hydrophobic chemicals, was used to make micro-particles of inclusion compounds that can be ingested by bacteriophagous nematodes, which do not distinguish these micro-particles from their food bacteria. Successful oral delivery of the hydrophobic fluorescent reagent 3,3'-dioctadecyloxacarbocyanine perchlorate into the intestines of C. elegans was observed. Oral administration of the hydrophobic antioxidants tocotrienol, astaxanthin, or γ-tocopherol, prolonged the nematode lifespan; tocotrienol rendered them resistant to infection with the opportunistic pathogen Legionella pneumophila. In contrast, older conventional delivery methods that involve incorporation of chemicals into the nematode growth medium or pouring chemicals onto the plate produced weaker fluorescence and no longevity effects. Our method efficiently and quantitatively delivers hydrophobic solutes to nematodes, and a minimum effective dose was estimated. In combination with our liposome method, this γCD method expands the usefulness of C. elegans for the discovery of functional food factors and for screening drug candidates.

Accuracy and safety of percutaneous pedicle screw placement using the K-wireless minimally invasive spine percutaneous pedicle screw system in Japan: A randomized active controlled study.

Background: Minimally invasive lumbar fusion has recently become a widely used technique worldwide. This randomized active controlled study was conducted to demonstrate the non-inferiority of the K-wireless Minimally Invasive Spine (MIS) Percutaneous Pedicle Screw (PPS) system compared with use of the six pedicle screw systems currently used in our practices with respect to the accuracy of pedicle screw placement.Also to compare the screw-insertion time and number of fluoroscopic observations during screw insertion between the groups. Methods: A total of 80 patients with degenerative spinal diseases or vertebral fractures were assigned, including 41 patients in the K-wireless MIS PPS system group (K-wireless group) and 39 in the control group (K-wire group).The accuracy of the screw insertion, screw-insertion time, number of fluoroscopic observations during screw insertion, and the incidence of adverse events were compared between the K-wireless group and the K-wire group. The accuracy rate was calculated as the number of screws with no breach divided by the total number of screws. Results: The accuracy rates of screw insertion were 85.7% and 75.0% in the K-wireless and K-wire groups, respectively, with an intergroup difference of 10.7% (95% confidence interval: 2.3-19.1%). The K-wireless group demonstrated non-inferiority compared with the K-wire group. The mean screw-insertion time was significantly shorter in the K-wireless group (2.62 and 2.97 min in the K-wireless and K-wire groups, respectively; P=0.005). There were also significantly fewer fluoroscopies in the K-wireless group (10.7 and 17.4 in the K-wireless and K-wire groups, respectively; P<0.001). There were no device-related or study treatment-related adverse events in either group. Conclusions: The accuracy of pedicle screw insertion using the K-wireless MIS PPS system was not inferior to that of existing products. In terms of safety, no product-related or treatment-related adverse events were identified in this study and no new safety concerns were noted.

Oxidative addition of an aromatic ortho C-H bond of tetraphosphine to asymmetric diiridium(i) centres.

Reactions of a tetraphosphine, meso-bis{[(diphenylphosphinomethyl)phenyl]phosphino}propane (dpmppp), with [IrCl(cod)]2 and CO (1 atm) or isocyanide (RNC) in the presence of NH4PF6 at 80-100 °C in dichloromethane/acetonitrile/acetone and/or methanol mixed solvents afforded asymmetric diiridium(ii) complexes, [Ir2(H)(Cl)(µ-(dpmppp-H)-κP(4)C)(CO)3]PF6 (1) and [Ir2(H)(µ-(dpmppp-H)-κP(4)C)(RNC)4)]-(PF6)2 (R = 2,6-xylyl (2), 2,4,6-mesityl (3); dpmppp-H = {PPh(o-C6H4)CH2P(Ph)(CH2)3P(Ph)CH2PPh2}(-)). A similar reaction with (t)BuNC resulted in the formation of a mononuclear Ir(III) complex of [Ir(H)(dpmppp-κP(3))((t)BuNC)2](PF6)2 (4). Complexes 1-3 were characterized by ESI mass spectrometry, (1)H and (31)P NMR spectroscopy and X-ray diffraction analyses. They were found to consist of cis/trans-P,P asymmetric Ir(II)-Ir(II) bonded dinuclear structures derived from oxidative addition of an ortho C-H bond of dpmppp (Ir-Ir = 2.8044(2) Å (1), 2.8569(2) Å (2), and 2.8524(5) Å (3)), resulting in a [IrPCCIr] intermetallic cyclometal-bridge and a terminal hydride. DFT calculations indicated the presence of Ir-Ir, Ir-H, and Ir-Cortho covalent bonds. Initial stages of the reactions with CO and XylNC at room temperature were investigated by (31)P{(1)H} NMR spectroscopy and found to contain a symmetrical Ir(I) dinuclear unit with dpmppp that was readily transformed into 1 and 2 upon heating. The Ir intermediate with XylNC, [Ir2(XylNC)4(µ-dpmppp)](PF6)2 (6), was isolated and characterized by X-ray crystallography and DFT calculations as an electron-deficient 32e(-) Ir species involving a Ir(I)→Ir(I) dative bond (2.7989(5) Å). The reaction pathways from 6 to 2 were investigated by DFT calculations. The present study suggested that a novel oxidative addition of an ortho C-H bond proceeded on the cis/trans-P,P asymmetric diiridium(i) scaffold supported by the tetraphosphine, dpmppp, which was assumed to be facilitated by dimetal cooperation with switching Ir→Ir dative interactions.

Reversible dioxygen binding on asymmetric dinuclear rhodium centres.

Electron-deficient dinuclear rhodium complexes [Rh2Cl2(µ-dpmppp)(RNC)] (1), with the linear tetraphosphine ligand dpmppp, showed reversible binding of molecular oxygen to form asymmetric dirhodium η(2)-peroxo complexes [Rh2Cl2(O2)(µ-dpmppp)(RNC)] (2) stabilized by a Rh→Rh dative bond.

Aspirin and NS-398 inhibit hepatocyte growth factor-induced invasiveness of human hepatoma cells.

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) activity and are considered to exert antitumor actions in a variety of cancer cells, although the effects are unlikely entirely due to COX inhibition. Because clinical observations suggest that hepatocyte growth factor (HGF) can promote metastasis of hepatoma cells while stimulating tumor invasiveness, we investigated the effect of aspirin and NS-398, a selective COX-2 inhibitor, on HGF-mediated invasiveness of HepG2 human hepatoma cells. HGF stimulated the invasiveness of HepG2 cells in Matrigel cell invasion assay, together with increased expression of matrix metalloproteinase (MMP) 9. Addition of aspirin or NS-398, similar to PD98059, which acts as a specific inhibitor of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK), an upstream kinase regulating extracellular signal-regulated kinase (ERK)1/2, abrogated such actions of HGF without affecting cell viability. Aspirin and NS-398, in contrast to PD98059, did not suppress ERK1/2 phosphorylation induced by HGF. However, both agents inhibited the kinase activity of ERK1/2 induced by HGF and repressed HGF-induced phosphorylation of 90-kd ribosomal S6 kinase (RSK) and Elk-1, key downstream substrates of ERK1/2, resulting in the suppression of transcriptional activity of Elk-1 as well as nuclear factor kappaB (NF-kappaB) and AP-1, which are involved in MMP-9 gene regulation. In conclusion, our results suggest that aspirin and NS-398 inhibit HGF-induced invasiveness of HepG2 human hepatoma cells through ERK1/2.