Takeda (Japan)

Recently, we demonstrated a significant increase of an oxidized nucleoside derived from RNA, 8-hydroxyguanosine (8OHG), and an oxidized amino acid, nitrotyrosine in vulnerable neurons of patients with Alzheimer disease (AD). To determine whether oxidative damage is an early- or end-stage event in the process of neurodegeneration in AD, we investigated the relationship between neuronal 8OHG and nitrotyrosine and histological and clinical variables, i.e. amyloid-beta (A beta) plaques and neurofibrillary tangles (NFT), as well as duration of dementia and apolipoprotein E (ApoE) genotype. Our findings show that oxidative damage is quantitatively greatest early in the disease and reduces with disease progression. Surprisingly, we found that increases in A beta deposition are associated with decreased oxidative damage. These relationships are more significant in ApoE epsilon4 carriers. Moreover, neurons with NFT show a 40%-56% decrease in relative 8OHG levels compared with neurons free of NFT. Our observations indicate that increased oxidative damage is an early event in AD that decreases with disease progression and lesion formation. These findings suggest that AD is associated with compensatory changes that reduce damage from reactive oxygen.

So far some nuclear receptors for bile acids have been identified. However, no cell surface receptor for bile acids has yet been reported. We found that a novel G protein-coupled receptor, TGR5, is responsive to bile acids as a cell-surface receptor. Bile acids specifically induced receptor internalization, the activation of extracellular signal-regulated kinase mitogen-activated protein kinase, the increase of guanosine 5′-O-3-thio-triphosphate binding in membrane fractions, and intracellular cAMP production in Chinese hamster ovary cells expressing TGR5. Our quantitative analyses for TGR5 mRNA showed that it was abundantly expressed in monocytes/macrophages in human and rabbit. Treatment with bile acids was found to suppress the functions of rabbit alveolar macrophages including phagocytosis and lipopolysaccharide-stimulated cytokine productions. We prepared a monocytic cell line expressing TGR5 by transfecting a TGR5 cDNA into THP-1 cells that did not express TGR5 originally. Treatment with bile acids suppressed the cytokine productions in the THP-1 cells expressing TGR5, whereas it did not influence those in the original THP-1 cells, suggesting that TGR5 is implicated in the suppression of macrophage functions by bile acids. So far some nuclear receptors for bile acids have been identified. However, no cell surface receptor for bile acids has yet been reported. We found that a novel G protein-coupled receptor, TGR5, is responsive to bile acids as a cell-surface receptor. Bile acids specifically induced receptor internalization, the activation of extracellular signal-regulated kinase mitogen-activated protein kinase, the increase of guanosine 5′-O-3-thio-triphosphate binding in membrane fractions, and intracellular cAMP production in Chinese hamster ovary cells expressing TGR5. Our quantitative analyses for TGR5 mRNA showed that it was abundantly expressed in monocytes/macrophages in human and rabbit. Treatment with bile acids was found to suppress the functions of rabbit alveolar macrophages including phagocytosis and lipopolysaccharide-stimulated cytokine productions. We prepared a monocytic cell line expressing TGR5 by transfecting a TGR5 cDNA into THP-1 cells that did not express TGR5 originally. Treatment with bile acids suppressed the cytokine productions in the THP-1 cells expressing TGR5, whereas it did not influence those in the original THP-1 cells, suggesting that TGR5 is implicated in the suppression of macrophage functions by bile acids. Bile acids are not simply byproducts of cholesterol metabolism but play essential roles in the absorption of dietary lipids and in the regulation of bile acid synthesis (1Russell D.W. Setchell K.D.R. Biochemistry. 1992; 31: 4737-4749Google Scholar). Farnesoid X receptor and pregnane X receptor have been recently identified as specific nuclear receptors for bile acids (2Makishima M. Okamoto A.Y. Repa J.J. Tu H. Learned R.M. Luk A. Hull M.V. Lustig K.D. Mangelsdorf D.J. Shan B. Science. 1999; 284: 1362-1365Google Scholar, 3Parks D.J. Blanchard S.G. Bledsoe R.K. Chandra G. Consler T.G. Kliewer S.A. Stimmel J.B. Willson T.M. Zavacki A.M. Moore D.D. Lehmann J.M. Science. 1999; 284: 1365-1368Google Scholar, 4Jones S.A. Moore L.B. Shenk J.L. Wisely G.B. Hamilton G.A. McKee D.D. Tomkinson N.C. LeCluyse E.L. Lambert M.H. Willson T.M. Kliewer S.A. Moore J.T. Mol. Endocrinol. 2000; 14: 27-39Google Scholar, 5Staudinger J.L. Goodwin B. Jones S.A. Hawkins-Brown D. MacKenzie K.I. LaTour A. Liu Y. Klaassen C.D. Brown K.K. Reinhard J. Willson T.M. Koller B.H. Kliewer S.A. Proc. Natl. Acad. Sci. U. S. A. 2001; 98: 3369-3374Google Scholar). Through the activation of farnesoid X receptor bile acids repress the expression of cholesterol 7α-hydroxylase, the rate-limiting enzyme in bile acid synthesis (2Makishima M. Okamoto A.Y. Repa J.J. Tu H. Learned R.M. Luk A. Hull M.V. Lustig K.D. Mangelsdorf D.J. Shan B. Science. 1999; 284: 1362-1365Google Scholar,3Parks D.J. Blanchard S.G. Bledsoe R.K. Chandra G. Consler T.G. Kliewer S.A. Stimmel J.B. Willson T.M. Zavacki A.M. Moore D.D. Lehmann J.M. Science. 1999; 284: 1365-1368Google Scholar). The activation of pregnane X receptor by bile acids results in both the repression of cholesterol 7α-hydroxylase and the transcriptional induction of cytochrome P450 3a, the bile acid-metabolizing enzyme (4Jones S.A. Moore L.B. Shenk J.L. Wisely G.B. Hamilton G.A. McKee D.D. Tomkinson N.C. LeCluyse E.L. Lambert M.H. Willson T.M. Kliewer S.A. Moore J.T. Mol. Endocrinol. 2000; 14: 27-39Google Scholar,5Staudinger J.L. Goodwin B. Jones S.A. Hawkins-Brown D. MacKenzie K.I. LaTour A. Liu Y. Klaassen C.D. Brown K.K. Reinhard J. Willson T.M. Koller B.H. Kliewer S.A. Proc. Natl. Acad. Sci. U. S. A. 2001; 98: 3369-3374Google Scholar). However, no cell surface receptor for bile acids has yet been identified. In hepatobiliary diseases including obstructive jaundice, viral hepatitis, and primary biliary cirrhosis, the mean serum concentration of bile acids exceeds 100 μm (range, 70–400 μm), whereas normally this remains below 10 μm (6Keane R.M. Gadacz T.R. Munster A.M. Birmingham W. Winchurch R.A. Surgery. 1984; 95: 439-443Google Scholar). At such high concentrations, bile acids are known to exhibit immunosuppressive effects on cell-mediated immunity and macrophage functions (6Keane R.M. Gadacz T.R. Munster A.M. Birmingham W. Winchurch R.A. Surgery. 1984; 95: 439-443Google Scholar, 7Kimmings A.N. van Deventer S.J.H. Obertop H. Rauws E.A.J. Gouma D.J. J. Am. Coll. Surg. 1995; 181: 567-581Google Scholar, 8Drivas G. James O. Wardle N. Br. Med. J. 1976; 26: 1568-1569Google Scholar). The phagocytic capacity of the reticuloendothelial system including Kupffer cells is depressed in cholestasis or obstructive jaundice (8Drivas G. James O. Wardle N. Br. Med. J. 1976; 26: 1568-1569Google Scholar). Cholestatic jaundice frequently causes infectious complications and endotoxemia, which are closely related to elevated serum bile acid levels (7Kimmings A.N. van Deventer S.J.H. Obertop H. Rauws E.A.J. Gouma D.J. J. Am. Coll. Surg. 1995; 181: 567-581Google Scholar, 9Pain J.A. Cahill C.J. Bailey M.E. Br. J. Surg. 1985; 72: 942-945Google Scholar). Furthermore, bile acids including deoxycholic acid (DCA) 1The abbreviations used are: DCA, deoxycholic acid; CDCA, chenodeoxycholic acid; LPS, lipopolysaccharide; IL, interleukin; TNFα, tumor necrosis factor α; GPCR, G protein-coupled receptor; CHO cells, Chinese hamster ovary cells; TGR5-GFP, a fusion protein of human TGR5 and green fluorescent protein; TLCA, taurine-conjugated lithocholic acid; CHO-TGR5 cells, CHO cells expressing human TGR5; THP-TGR5 cells, THP-1 cells expressing human TGR5; MAP kinase, mitogen-activated protein kinase; AMs, adherent alveolar macrophage cells; LCA, lithocholic acid; CA, cholic acid; CHAPS, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid; GTPγS, guanosine 5′-3-O-(thio)triphosphate 1The abbreviations used are: DCA, deoxycholic acid; CDCA, chenodeoxycholic acid; LPS, lipopolysaccharide; IL, interleukin; TNFα, tumor necrosis factor α; GPCR, G protein-coupled receptor; CHO cells, Chinese hamster ovary cells; TGR5-GFP, a fusion protein of human TGR5 and green fluorescent protein; TLCA, taurine-conjugated lithocholic acid; CHO-TGR5 cells, CHO cells expressing human TGR5; THP-TGR5 cells, THP-1 cells expressing human TGR5; MAP kinase, mitogen-activated protein kinase; AMs, adherent alveolar macrophage cells; LCA, lithocholic acid; CA, cholic acid; CHAPS, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid; GTPγS, guanosine 5′-3-O-(thio)triphosphate and chenodeoxycholic acid (CDCA) have been demonstrated to have inhibitory activities on the lipopolysaccharide (LPS)-induced production of cytokines in macrophages, including interleukin (IL)-1, IL-6, and tumor necrosis factor α (TNFα) (10Greve J.W. Gouma D.J. Buurman W.A. Hepatology. 1989; 10: 454-458Google Scholar, 11Calmus Y. Guechot J. Podevin P. Bonnefis M.T. Giboudeau J. Poupon R. Hepatology. 1992; 16: 719-723Google Scholar). However, the precise mechanisms involved have remained unclear. Here we show that a novel G protein-coupled receptor (GPCR), TGR5, is responsive to bile acids and discuss the possibility that bile acids suppress macrophage functions via TGR5. Expression vectors with human TGR5 cDNA (pAKKO-TGR5) and rat Gi cDNA (pAKKO-Gi) were, respectively, constructed by inserting their coding regions into pAKKO-111H (12Hinuma S. Hosoya M. Ogi K. Tanaka H. Nagai Y. Onda H. Biochim. Biophys. Acta. 1994; 1219: 251-259Google Scholar). Chinese hamster ovary (CHO) dhfr− cells stably transfected with only pAKKO-111H (mock CHO cells) were cultured in a medium and used as host cells. TGR5, luciferase, and Gi were transiently expressed in the host cells by co-transfection using a LipofectAMINE 2000 (Invitrogen). After culture overnight, the cells were incubated with test compounds for 4 h. Luciferase activity was measured with a PicaGene LT.2.0 (Toyo Ink). The expression vector with a fusion protein of human TGR5 and green fluorescent protein (TGR5-GFP), pAKKO-TGR5-GFP, was constructed by the insertion of a fused DNA so that the human TGR5- and GFP-coding regions were connected in tandem. Mock CHO cells seeded onto chambered coverglasses (Nalgene) were transfected with pAKKO-TGR5-GFP and cultured overnight. After treatment with 50 μm taurine-conjugated lithocholic acid (TLCA) for 30 min, the cells were examined under a confocal fluorescence microscope. CHO cells expressing human TGR5 (CHO-TGR5) cells were established by transfecting pAKKO-TGR5 into CHO dhfr− cells (12Hinuma S. Hosoya M. Ogi K. Tanaka H. Nagai Y. Onda H. Biochim. Biophys. Acta. 1994; 1219: 251-259Google Scholar). THP-1 cells expressing human TGR5 (THP-TGR5) cells were established by transfecting pcDNA 3.1 (Invitrogen) inserted with human TGR5 cDNA and selecting neomycin-resistant cells. CHO-TGR5 and mock CHO cells were cultured in a medium containing 0.5% dialyzed fetal bovine serum and then additionally cultured overnight in a medium containing 0.1% bovine serum albumin. The cells were preincubated with fresh medium for 3 h and then exposed to TLCA at 2 μm. Western blotting was performed with a PhosphoPlus p44/42 MAP kinase (Thr-202/Tyr-204) antibody kit (Cell Signaling Technology). Membrane fractions prepared from CHO-TGR5 and mock CHO cells as described elsewhere (13Ohtaki T. Ogi K. Masuda Y. Mitsuoka K. Fujiyoshi Y. Kitada C. Sawada H. Onda H. Fujino M. J. Biol. Chem. 1998; 273: 15464-15473Google Scholar) were suspended at 500 μg/ml in a binding buffer (pH 7.4) containing 50 mm Tris, 150 mm NaCl, 5 mm MgCl2, 1 mm EGTA, 30 μm GDP, and 0.05% CHAPS. The membrane fractions (196 μl) were mixed with TLCA (2 μl of dimethyl sulfoxide solution) and 100 nm [35S]GTPγS (Amersham Biosciences) (2 μl). After incubation at 25 °C for 60 min, the reaction mixtures were diluted with 1.8 ml of a chilled washing buffer, which was a modified binding buffer without GDP, and then filtered through nitrocellulose filters (Schleicher & Schuell). The filters were washed with 1.8 ml of the washing buffer, dried, and subjected to a liquid scintillation counter to measure [35S]GTPγS bound to the membrane fractions. CHO-TGR5 cells (2 × 104) were incubated with the samples for 20 min in the presence of 0.2 mm 3-isobutyl-1-methylxanthine (Sigma). Rabbit adherent alveolar macrophage cells (AMs) (2 × 105 cells) were treated with TLCA (200 μm) for 4 min in the presence of 1 mm3-isobutyl-1-methylxanthine. THP-TGR5 or THP-1 cells (1 × 105 cells) were treated with bile acids (50 μm) for 20 min in the presence of 1 mm3-isobutyl-1-methylxanthine. The amount of cAMP was determined with a cAMP-Screen System (Applied Biosystems). Poly(A)+RNAs from human tissues and a human blood fraction multiple tissue cDNA panel were purchased from Clontech. After a 48-h culture, AMs in the culture plates were washed twice with fresh medium. Total RNAs were extracted from the adherent cells or rabbit tissues using an Isogen (Nippongene). Random-primed cDNAs were synthesized and then subjected to quantitative reverse transcription-PCR analysis using an ABI Prism 7700 sequence detector (14Fujii R. Fukusumi S. Hosoya M. Kawamata Y. Habara Y. Hinuma S. Sekiguchi M. Kitada C. Kurokawa T. Nishimura O. Onda H. Sumino Y. Fujino M. Regul. Pept. 1999; 83: 1-10Google Scholar). AMs were obtained by the lavage of lungs of female New Zealand White rabbits weighing 2.5–3.0 kg (Kitayama LABES), purified through gradient centrifugation with a Ficoll-Paque Plus (Amersham Pharmacia), and then suspended in Dulbecco's modified Eagle's medium containing 2% fetal bovine serum, nonessential amino acids, and antibiotics. The viability of the cells was more than 95% as determined by trypan blue-exclusion tests. The cells were comprised of more than 90% macrophages as determined by phagocytic tests and morphological criteria. Rabbit AMs thereby obtained were cultured overnight and used for experiments. After pretreatment with bile acids (100 μm) for 16 h, AMs were incubated with heat-inactivated yeast cells in the presence of fresh rabbit serum for 40 min, and then the AMs containing yeast cells were counted under a microscope. In the assay for cytokine secretion, AMs were preincubated with bile acids for 1 h and then treated with 1 ng/ml LPS (Escherichia coli O111:B4, Wako) in the presence of bile acids for 12 h. THP-TGR5 or THP-1 cells were treated as in AMs with the exception of LPS concentration at 50 ng/ml. TNFα concentrations (which could be neutralized by the anti-TNFα antibody) in the supernatants were measured by bioassay using L929 cells (15Evans T.J. Mol. Biotechnol. 2000; 15: Scholar). In for in the we found a human DNA sequence coding for a novel on this we a cDNA the GPCR, as TGR5, from human We TGR5 cDNAs in TGR5 and amino acid respectively, with that in and the known TGR5 at and amino acid with and N. J.A. J. 2001; We to for TGR5 as an we a to for by S. Y. R. Kawamata Y. Hosoya M. Fukusumi S. Kitada C. Y. T. H. Sekiguchi M. Kurokawa T. Nishimura O. Onda H. Fujino M. 1998; Scholar, S. Onda H. Fujino M. J. Mol. Med. 1999; in this we a We a fused to and expression vectors of human TGR5 and rat G protein α Gi the of into CHO cells. We then more than compounds by activities induced in to intracellular cAMP production and specific to bile acids including TLCA, lithocholic acid DCA, and at 25 μm. In we that TGR5 from not only human but the examined to compounds in this assay not suggesting that TGR5 functions as a receptor for bile acids in TGR5 was to be a on sequence we expressed in CHO cells and then examined J.L. Sci. 2000; Scholar, Y. K. G. W. Y. Biol. 2000; Scholar). In the of a was at the membrane but into the in to TLCA that the of TLCA and TGR5 in the we prepared membrane fractions from CHO-TGR5 and examined [35S]GTPγS binding to fractions levels of the binding were at 1 μm the at μm TLCA in a However, such in [35S]GTPγS binding were not in the membrane fractions of mock CHO cells. signal-regulated kinase MAP kinase is in the of Y. K. G. W. Y. Biol. 2000; Scholar, J. G. J. J. M. S. M.H. 1999; Scholar). Treatment with TLCA extracellular signal-regulated kinase MAP kinase activity in CHO-TGR5 cells but not in mock CHO cells 2 In we found that TLCA, LCA, DCA, CDCA, and cholic acid induced the production of cAMP in CHO-TGR5 cells 3 at the concentrations of and bile acids did not the production of cAMP in mock CHO cells not We examined cholesterol and related compounds in cAMP production in CHO-TGR5 cells 3 The activities to increase in with and not only but and were acid and cholesterol were only but showed results that the as as the acid are for the to exhibit activity on TGR5. acid and which are for farnesoid X receptor, pregnane X receptor, and X receptor, D.J. Blanchard S.G. Bledsoe R.K. Chandra G. Consler T.G. Kliewer S.A. Stimmel J.B. Willson T.M. Zavacki A.M. Moore D.D. Lehmann J.M. Science. 1999; 284: 1365-1368Google Scholar, 4Jones S.A. Moore L.B. Shenk J.L. Wisely G.B. Hamilton G.A. McKee D.D. Tomkinson N.C. LeCluyse E.L. Lambert M.H. Willson T.M. Kliewer S.A. Moore J.T. Mol. Endocrinol. 2000; 14: 27-39Google Scholar, T.R. Mangelsdorf D.J. showed activity to TGR5. we CHO cell expressing TLCA induced a to TGR5 but not to or not results that TGR5 functions as a specific cell surface receptor for bile of cAMP production in CHO-TGR5 cells by bile acids. analyses for cAMP production induced by bile acids. The the of bile acids. of cAMP production activities in bile acids and in related CHO-TGR5 cells were treated with the compounds at 2 μm. the mean of in cAMP production in at 10 μm. acid; In the expression levels of TGR5 mRNA were high in and rabbit but in rat and not We tissue in human and rabbit by reverse levels of TGR5 mRNA were in human and whereas levels were found in tissues including and fetal In human TGR5 mRNA was in the 4 rabbit the of TGR5 mRNA was in the We a high of TGR5 mRNA in AMs, that at of the cells expressing TGR5 is a We used rabbit AMs in the experiments. increase of intracellular cAMP results in the suppression of cytokine production in macrophages T. C. T. T. S. J. Tanaka H. N. Nagai H. Scholar). In has been to as the LPS receptor R.A. Science. Scholar). as demonstrated bile acids were to macrophage functions via TGR5, we examined this TLCA was found to increase cAMP production in AMs TLCA, and suppressed phagocytic activity in AMs 5 Furthermore, TLCA the induction of cytokine TNFα, IL-6, and in AMs with LPS 5 TNFα was with LCA, DCA, and and their or inhibitory activities with the cAMP production activities on CHO-TGR5 cells. the effects of bile acids were through TGR5, we established a human monocytic cell line expressing TGR5 by transfecting an expression vector of human TGR5 into THP-1 cells. The original THP-1 cells expressed TGR5 TLCA, LCA, and induced cAMP production in THP-TGR5 cells, whereas TLCA did not so in THP-1 cells TNFα was by bile acids including TLCA, LCA, DCA, and in THP-TGR5 cells but not in THP-1 cells the inhibitory activities of bile acids on TNFα from THP-TGR5 cells those in rabbit by bile acids via TGR5 in THP-1 cells expressing TGR5. increase in cAMP production in THP-TGR5 or THP-1 cells by bile acids. suppression of TNFα in THP-TGR5 cells by bile acids. of bile acids on TNFα in THP-1 cells. THP-TGR5 or THP-1 cells were treated as in 5 with the exception of LPS concentration at 50 ng/ml. the mean with We have a novel GPCR, TGR5, on the of sequence of the TGR5 was found to be to which has been recently by S. S. T. H. S. Scholar). However, the and functions of this receptor have been In this we have demonstrated that TGR5 functions as a cell surface receptor responsive to bile acids as nuclear receptors for bile acids have been we this is the on the of a responsive to bile acids. We have found that the primary and to bile acids are in TGR5 and suggesting that TGR5 has some We to a binding of to the membrane fractions of CHO-TGR5 but showed high binding to and cell membrane fractions not We that compounds with high to TGR5 be to the binding of a to TGR5 in However, of we demonstrated that TGR5 functions as a cell surface receptor responsive to bile acids on the of of using a fusion protein of TGR5 and we found that the fusion protein was at the membrane of CHO cells, and bile acids induced the of the fusion protein from the cell membrane to the Furthermore, we demonstrated that [35S]GTPγS binding were specifically induced in the membrane fractions prepared from CHO-TGR5 by the of and is specifically induced in G to results that TGR5 is specifically by with the results of and [35S]GTPγS TGR5 is to be responsive to bile acids. The treatment of bile acids specifically induced the activation of extracellular signal-regulated kinase MAP kinase and intracellular cAMP production in CHO cells expressing TGR5. However, we could not in intracellular in CHO cells expressing TGR5, suggesting that TGR5 to but not to or have not only nuclear receptors but cell surface receptors T. T. K. Y. T. Scholar). However, that the nuclear and cell surface bile acid receptors or of bile acids showed activity on TGR5. However, are to the nuclear receptors in the of a specific bile acids as In the of the bile acids were for TGR5 than for the nuclear receptors 10 the tissue of TGR5 mRNA from those of the nuclear high levels of TGR5 mRNA were in the and whereas the nuclear receptors are expressed in the and (2Makishima M. Okamoto A.Y. Repa J.J. Tu H. Learned R.M. Luk A. Hull M.V. Lustig K.D. Mangelsdorf D.J. Shan B. Science. 1999; 284: 1362-1365Google Scholar, 3Parks D.J. Blanchard S.G. Bledsoe R.K. Chandra G. Consler T.G. Kliewer S.A. Stimmel J.B. Willson T.M. Zavacki A.M. Moore D.D. Lehmann J.M. Science. 1999; 284: 1365-1368Google Scholar, 4Jones S.A. Moore L.B. Shenk J.L. Wisely G.B. Hamilton G.A. McKee D.D. Tomkinson N.C. LeCluyse E.L. Lambert M.H. Willson T.M. Kliewer S.A. Moore J.T. Mol. Endocrinol. 2000; 14: 27-39Google Scholar, 5Staudinger J.L. Goodwin B. Jones S.A. Hawkins-Brown D. MacKenzie K.I. LaTour A. Liu Y. Klaassen C.D. Brown K.K. Reinhard J. Willson T.M. Koller B.H. Kliewer S.A. Proc. Natl. Acad. Sci. U. S. A. 2001; 98: 3369-3374Google Scholar). immunosuppressive effects of bile acids have been (6Keane R.M. Gadacz T.R. Munster A.M. Birmingham W. Winchurch R.A. Surgery. 1984; 95: 439-443Google Scholar, 7Kimmings A.N. van Deventer S.J.H. Obertop H. Rauws E.A.J. Gouma D.J. J. Am. Coll. Surg. 1995; 181: 567-581Google Scholar, 8Drivas G. James O. Wardle N. Br. Med. J. 1976; 26: 1568-1569Google Scholar, 9Pain J.A. Cahill C.J. Bailey M.E. Br. J. Surg. 1985; 72: 942-945Google Scholar, J.W. Gouma D.J. Buurman W.A. Hepatology. 1989; 10: 454-458Google Scholar, 11Calmus Y. Guechot J. Podevin P. Bonnefis M.T. Giboudeau J. Poupon R. Hepatology. 1992; 16: 719-723Google the precise mechanisms have remained unclear. The phagocytic capacity of the macrophages including Kupffer cells is depressed in cholestasis or obstructive jaundice (8Drivas G. James O. Wardle N. Br. Med. J. 1976; 26: 1568-1569Google Scholar). Furthermore, bile acids including and have been to suppress production of cytokines in macrophages, including IL-6, and TNFα (10Greve J.W. Gouma D.J. Buurman W.A. Hepatology. 1989; 10: 454-458Google Scholar, 11Calmus Y. Guechot J. Podevin P. Bonnefis M.T. Giboudeau J. Poupon R. Hepatology. 1992; 16: 719-723Google Scholar). for the is that bile acids to cell However, we that cell were more than 90% the treatment of rabbit AMs with bile acids to μm. has been that cell of are not by the incubation with μm DCA, CDCA, and acid (6Keane R.M. Gadacz T.R. Munster A.M. Birmingham W. Winchurch R.A. Surgery. 1984; 95: 439-443Google Scholar). it is that the immunosuppressive functions of bile acids are the results of to cell (10Greve J.W. Gouma D.J. Buurman W.A. Hepatology. 1989; 10: 454-458Google Scholar) that bile acids such as and TNFα in human (10Greve J.W. Gouma D.J. Buurman W.A. Hepatology. 1989; 10: 454-458Google Scholar). have demonstrated that bile acids not as measured in a that the of bile acids is not a of bile acids and In bile acids induced cAMP production in rabbit AMs and THP-TGR5 cells. has been known that an increase of intracellular cAMP results in the suppression of cytokine production in macrophages T. C. T. T. S. J. Tanaka H. N. Nagai H. Scholar). We showed that TGR5 was abundantly expressed in monocytes/macrophages and that bile acids including LCA, DCA, and TNFα in rabbit In bile acids suppressed TNFα in THP-TGR5 cells but not in THP-1 cells. results that the suppression of macrophage functions by bile acids is at via TGR5 through an increase of cAMP However, we could not that the suppression of macrophage functions was via TGR5 by of experiments. the functions of TGR5, we to for TGR5 to the TGR5 but we to RNAs TGR5 is by a sequence so that it was to We but of were to suppress the expression of TGR5. We that to this with high be results that TGR5 a in the regulation of macrophage functions by bile acids, we not the possibility that TGR5 has TGR5 mRNA is not only in tissues but in Our that TGR5 is responsive to bile acids an in the functions of TGR5 in We Y. O. and H. Onda for and H. and A. for

Normal processing of the amyloid beta protein precursor (beta APP) results in secretion of a soluble 4-kilodalton protein essentially identical to the amyloid beta protein (A beta) that forms insoluble fibrillar deposits in Alzheimer's disease. Human neuroblastoma (M17) cells transfected with constructs expressing wild-type beta APP or the beta APP717 mutants linked to familial Alzheimer's disease were compared by (i) isolation of metabolically labeled 4-kilodalton A beta from conditioned medium, digestion with cyanogen bromide, and analysis of the carboxyl-terminal peptides released, or (ii) analysis of the A beta in conditioned medium with sandwich enzyme-linked immunosorbent assays that discriminate A beta 1-40 from the longer A beta 1-42. Both methods demonstrated that the 4-kilodalton A beta released from wild-type beta APP is primarily but not exclusively A beta 1-40. The beta APP717 mutations, which are located three residues carboxyl to A beta 43, consistently caused a 1.5- to 1.9-fold increase in the percentage of longer A beta generated. Long A beta (for example, A beta 1-42) forms insoluble amyloid fibrils more rapidly than A beta 1-40. Thus, the beta APP717 mutants may cause Alzheimer's disease because they secrete increased amounts of long A beta, thereby fostering amyloid deposition.

The finding that oxidative damage, including that to nucleic acids, in Alzheimer's disease is primarily limited to the cytoplasm of susceptible neuronal populations suggests that mitochondrial abnormalities might be part of the spectrum of chronic oxidative stress of Alzheimer's disease. In this study, we used in situ hybridization to mitochondrial DNA (mtDNA), immunocytochemistry of cytochrome oxidase, and morphometry of electron micrographs of biopsy specimens to determine whether there are mitochondrial abnormalities in Alzheimer's disease and their relationship to oxidative damage marked by 8-hydroxyguanosine and nitrotyrosine. We found that the same neurons showing increased oxidative damage in Alzheimer's disease have a striking and significant increase in mtDNA and cytochrome oxidase. Surprisingly, much of the mtDNA and cytochrome oxidase is found in the neuronal cytoplasm and in the case of mtDNA, the vacuoles associated with lipofuscin. Morphometric analysis showed that mitochondria are significantly reduced in Alzheimer's disease. The relationship shown here between the site and extent of mitochondrial abnormalities and oxidative damage suggests an intimate and early association between these features in Alzheimer's disease.

Electrocatalytic activity of Pt alloys with Ni, Co, and Fe, formed by sputtering, was investigated with regard to the oxygen reduction reaction (ORR) in perchloric acid solution. Hydrodynamic voltammograms with rotated electrodes were used to measure the electrocatalytic activity. Maximum activity was observed at ca. 30, 40, and 50% content of Ni, Co, and Fe, respectively, by which 10, 15, and 20 times larger kinetic current densities than that of pure Pt were attained. X‐ray photoelectron spectroscopy analysis of the surfaces after the reaction indicated that the active surfaces were covered by a few monolayers of Pt. We present an enhancing mechanism for the ORR based on an increased d‐electron vacancy of the thin Pt surface layer caused by underlying alloy. Results of this work contribute in development of new active cathode catalysts for fuel cells used as power sources of electric vehicles, etc. © 1999 The Electrochemical Society. All rights reserved.

Purpose Retrospective studies suggest that metastasis-directed therapy (MDT) for oligorecurrent prostate cancer (PCa) improves progression-free survival. We aimed to assess the benefit of MDT in a randomized phase II trial. Patients and Methods In this multicenter, randomized, phase II study, patients with asymptomatic PCa were eligible if they had had a biochemical recurrence after primary PCa treatment with curative intent, three or fewer extracranial metastatic lesions on choline positron emission tomography-computed tomography, and serum testosterone levels > 50 ng/mL. Patients were randomly assigned (1:1) to either surveillance or MDT of all detected lesions (surgery or stereotactic body radiotherapy). Surveillance was performed with prostate-specific antigen (PSA) follow-up every 3 months, with repeated imaging at PSA progression or clinical suspicion for progression. Random assignment was balanced dynamically on the basis of two factors: PSA doubling time (≤ 3 v > 3 months) and nodal versus non-nodal metastases. The primary end point was androgen deprivation therapy (ADT)-free survival. ADT was started at symptomatic progression, progression to more than three metastases, or local progression of known metastases. Results Between August 2012 and August 2015, 62 patients were enrolled. At a median follow-up time of 3 years (interquartile range, 2.3-3.75 years), the median ADT-free survival was 13 months (80% CI, 12 to 17 months) for the surveillance group and 21 months (80% CI, 14 to 29 months) for the MDT group (hazard ratio, 0.60 [80% CI, 0.40 to 0.90]; log-rank P = .11). Quality of life was similar between arms at baseline and remained comparable at 3-month and 1-year follow-up. Six patients developed grade 1 toxicity in the MDT arm. No grade 2 to 5 toxicity was observed. Conclusion ADT-free survival was longer with MDT than with surveillance alone for oligorecurrent PCa, suggesting that MDT should be explored further in phase III trials.

Abstract Drainage basins in many parts of the world are ungauged or poorly gauged, and in some cases existing measurement networks are declining. The problem is compounded by the impacts of human-induced changes to the land surface and climate, occurring at the local, regional and global scales. Predictions of ungauged or poorly gauged basins under these conditions are highly uncertain. The IAHS Decade on Predictions in Ungauged Basins, or PUB, is a new initiative launched by the International Association of Hydrological Sciences (IAHS), aimed at formulating and implementing appropriate science programmes to engage and energize the scientific community, in a coordinated manner, towards achieving major advances in the capacity to make predictions in ungauged basins. The PUB scientific programme focuses on the estimation of predictive uncertainty, and its subsequent reduction, as its central theme. A general hydrological prediction system contains three components: (a) a model that describes the key processes of interest, (b) a set of parameters that represent those landscape properties that govern critical processes, and (c) appropriate meteorological inputs (where needed) that drive the basin response. Each of these three components of the prediction system, is either not known at all, or at best known imperfectly, due to the inherent multi-scale space—time heterogeneity of the hydrological system, especially in ungauged basins. PUB will therefore include a set of targeted scientific programmes that attempt to make inferences about climatic inputs, parameters and model structures from available but inadequate data and process knowledge, at the basin of interest and/or from other similar basins, with robust measures of the uncertainties involved, and their impacts on predictive uncertainty. Through generation of improved understanding, and methods for the efficient quantification of the underlying multi-scale heterogeneity of the basin and its response, PUB will inexorably lead to new, innovative methods for hydrological predictions in ungauged basins in different parts of the world, combined with significant reductions of predictive uncertainty. In this way, PUB will demonstrate the value of data, as well as provide the information needed to make predictions in ungauged basins, and assist in capacity building in the use of new technologies. This paper presents a summary of the science and implementation plan of PUB, with a call to the hydrological community to participate actively in the realization of these goals.

Variable importance (VI) tools describe how much covariates contribute to a prediction model's accuracy. However, important variables for one well-performing model (for example, a linear model $f(\mathbf{x})=\mathbf{x}^{T}β$ with a fixed coefficient vector $β$) may be unimportant for another model. In this paper, we propose model class reliance (MCR) as the range of VI values across all well-performing model in a prespecified class. Thus, MCR gives a more comprehensive description of importance by accounting for the fact that many prediction models, possibly of different parametric forms, may fit the data well. In the process of deriving MCR, we show several informative results for permutation-based VI estimates, based on the VI measures used in Random Forests. Specifically, we derive connections between permutation importance estimates for a single prediction model, U-statistics, conditional variable importance, conditional causal effects, and linear model coefficients. We then give probabilistic bounds for MCR, using a novel, generalizable technique. We apply MCR to a public data set of Broward County criminal records to study the reliance of recidivism prediction models on sex and race. In this application, MCR can be used to help inform VI for unknown, proprietary models.

Chemokines direct tissue invasion by specific leukocyte populations. Thus, chemokines may play a role in multiple sclerosis (MS), an idiopathic disorder in which the central nervous system (CNS) inflammatory reaction is largely restricted to mononuclear phagocytes and T cells. We asked whether specific chemokines were expressed in the CNS during acute demyelinating events by analyzing cerebrospinal fluid (CSF), whose composition reflects the CNS extracellular space. During MS attacks, we found elevated CSF levels of three chemokines that act toward T cells and mononuclear phagocytes: interferon-gamma-inducible protein of 10 kDa (IP-10); monokine induced by interferon-gamma (Mig); and regulated on activation, normal T-cell expressed and secreted (RANTES). We then investigated whether specific chemokine receptors were expressed by infiltrating cells in demyelinating MS brain lesions and in CSF. CXCR3, an IP-10/Mig receptor, was expressed on lymphocytic cells in virtually every perivascular inflammatory infiltrate in active MS lesions. CCR5, a RANTES receptor, was detected on lymphocytic cells, macrophages, and microglia in actively demyelinating MS brain lesions. Compared with circulating T cells, CSF T cells were significantly enriched for cells expressing CXCR3 or CCR5. Our results imply pathogenic roles for specific chemokine-chemokine receptor interactions in MS and suggest new molecular targets for therapeutic intervention.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non-Small Cell Lung Cancer (NSCLC) address all aspects of management for NSCLC. These NCCN Guidelines Insights focus on recent updates to the NCCN Guidelines regarding targeted therapies, immunotherapies, and their respective biomarkers.

ADVERTISEMENT RETURN TO ISSUEPerspectiveNEXTMetal−Ligand Bifunctional Catalysis: A Nonclassical Mechanism for Asymmetric Hydrogen Transfer between Alcohols and Carbonyl CompoundsRyoji Noyori, Masashi Yamakawa, and Shohei HashiguchiView Author Information Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan, Kinjo Gakuin University, Omori, Moriyama, Nagoya 463-8521, Japan, and Medicinal Chemistry Laboratories, Pharmaceutical Research Division, Takeda Chemical Industries, Ltd., 2-17-85 Juso-honmachi, Yodogawa, Osaka 532-8686, Japan Cite this: J. Org. Chem. 2001, 66, 24, 7931–7944Publication Date (Web):November 3, 2001Publication History Received16 July 2001Published online3 November 2001Published inissue 1 November 2001https://pubs.acs.org/doi/10.1021/jo010721whttps://doi.org/10.1021/jo010721wreview-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views12676Altmetric-Citations798LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Alcohols,Anions,Hydrocarbons,Ketones,Ligands Get e-Alerts

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a Public Health Emergency of International Concern, which was officially declared by the World Health Organization. SARS-CoV-2 is a member of the family Coronaviridae that consists of a group of enveloped viruses with single-stranded RNA genome, which cause diseases ranging from common colds to acute respiratory distress syndrome. Although the major transmission routes of SARS-CoV-2 are inhalation of aerosol/droplet and person-to-person contact, currently available evidence indicates that the viral RNA is present in wastewater, suggesting the need to better understand wastewater as potential sources of epidemiological data and human health risks. Here, we review the current knowledge related to the potential of wastewater surveillance to understand the epidemiology of COVID-19, methodologies for the detection and quantification of SARS-CoV-2 in wastewater, and information relevant for human health risk assessment of SARS-CoV-2. There has been growing evidence of gastrointestinal symptoms caused by SARS-CoV-2 infections and the presence of viral RNA not only in feces of infected individuals but also in wastewater. One of the major challenges in SARS-CoV-2 detection/quantification in wastewater samples is the lack of an optimized and standardized protocol. Currently available data are also limited for conducting a quantitative microbial risk assessment (QMRA) for SARS-CoV-2 exposure pathways. However, modeling-based approaches have a potential role to play in reducing the impact of the ongoing COVID-19 outbreak. Furthermore, QMRA parameters obtained from previous studies on relevant respiratory viruses help to inform risk assessments of SARS-CoV-2. Our understanding on the potential role of wastewater in SARS-CoV-2 transmission is largely limited by knowledge gaps in its occurrence, persistence, and removal in wastewater. There is an urgent need for further research to establish methodologies for wastewater surveillance and understand the implications of the presence of SARS-CoV-2 in wastewater.

The beta-chemokine receptor CCR5 is considered to be an attractive target for inhibition of macrophage-tropic (CCR5-using or R5) HIV-1 replication because individuals having a nonfunctional receptor (a homozygous 32-bp deletion in the CCR5 coding region) are apparently normal but resistant to infection with R5 HIV-1. In this study, we found that TAK-779, a nonpeptide compound with a small molecular weight (Mr 531.13), antagonized the binding of RANTES (regulated on activation, normal T cell expressed and secreted) to CCR5-expressing Chinese hamster ovary cells and blocked CCR5-mediated Ca2+ signaling at nanomolar concentrations. The inhibition of beta-chemokine receptors by TAK-779 appeared to be specific to CCR5 because the compound antagonized CCR2b to a lesser extent but did not affect CCR1, CCR3, or CCR4. Consequently, TAK-779 displayed highly potent and selective inhibition of R5 HIV-1 replication without showing any cytotoxicity to the host cells. The compound inhibited the replication of R5 HIV-1 clinical isolates as well as a laboratory strain at a concentration of 1.6-3.7 nM in peripheral blood mononuclear cells, though it was totally inactive against T-cell line-tropic (CXCR4-using or X4) HIV-1.

In this study we used an in situ approach to identify the oxidized nucleosides 8-hydroxydeoxyguanosine (8OHdG) and 8-hydroxyguanosine (8OHG), markers of oxidative damage to DNA and RNA, respectively, in cases of Alzheimer's disease (AD). The goal was to determine whether nuclear and mitochondrial DNA as well as RNA is damaged in AD. Immunoreactivity with monoclonal antibodies 1F7 or 15A3 recognizing both 8OHdG and 8OHG was prominent in the cytoplasm and to a lesser extent in the nucleolus and nuclear envelope in neurons within the hippocampus, subiculum, and entorhinal cortex as well as frontal, temporal, and occipital neocortex in cases of AD, whereas similar structures were immunolabeled only faintly in controls. Relative density measurement showed that there was a significant increase (p < 0.0001) in 8OHdG and 8OHG immunoreactivity with 1F7 in cases of AD (n = 22) as compared with senile (n = 13), presenile (n = 10), or young controls (n = 4). Surprisingly, the oxidized nucleoside was associated predominantly with RNA because immunoreaction was diminished greatly by preincubation in RNase but only slightly by DNase. This is the first evidence of increased RNA oxidation restricted to vulnerable neurons in AD. The subcellular localization of damaged RNA showing cytoplasmic predominance is consistent with the hypothesis that mitochondria may be a major source of reactive oxygen species that cause oxidative damage in AD.

In rat brain three members of the protein kinase C family encoded by cDNAs termed delta, epsilon, and zeta were newly identified by molecular cloning and sequence analysis. The new members have a common structure that is closely related to but clearly distinct from the four members of the family previously isolated having alpha-, beta I-, beta II-, and gamma-sequences, although the zeta-cDNA available at present does not appear to contain a complete reading frame for protein kinase C. The delta-, epsilon-, and zeta-cDNAs all encode a characteristic cysteine-rich sequence and protein kinase domain sequence, both of which are highly homologous among the protein kinase C family. However, the new members lack one of the conserved regions that is present in alpha-, beta I-, beta II-, and gamma-sequences. An additional cDNA clone termed epsilon' was isolated, which is identical with epsilon-cDNA except for a short sequence at the 5'-terminal end region. The two members having delta- and epsilon-sequences were expressed in COS 7 cells, and partially purified and characterized. The enzymes having delta- and epsilon-sequences depend on phospholipid and diacylglycerol for the enzymatic activity, but their properties slightly differ from the previously known members of protein kinase C. Northern blot analysis suggests that the new members of protein kinase C exist in the brain and some other tissues.

Biochemical and immunocytochemical analyses were performed to evaluate the composition of the amyloid beta protein (A beta) deposited in the brains of patients with Alzheimer's disease (AD). To quantitate all A beta s present, cerebral cortex was homogenized in 70% formic acid, and the supernatant was analyzed by sandwich enzyme-linked immunoabsorbent assays specific for various forms of A beta. In 9 of 27 AD brains examined, there was minimal congophilic angiopathy and virtually all A beta (96%) ended at A beta 42(43). The other 18 AD brains contained increasing amounts of A beta ending at A beta 40. From this set, 6 brains with substantial congophilic angiopathy were separately analyzed. In these brains, the amount of A beta ending at A beta 42(43) was much the same as in brains with minimal congophilic angiopathy, but a large amount of A beta ending at A beta 40 (76% of total A beta) was also present. Immunocytochemical analysis with monoclonal antibodies selective for A beta s ending at A beta 42(43) or A beta 40 confirmed that, in brains with minimal congophilic angiopathy, virtually all A beta is A beta ending at A beta 42(43) and showed that this A beta is deposited in senile plaques of all types. In the remaining AD brains, A beta 42(43) was deposited in a similar fashion in plaques, but, in addition, widely varying amounts of A beta ending at A beta 40 were deposited, primarily in blood vessel walls, where some A beta ending at A beta 42(43) was also present. These observations indicate that A beta s ending at A beta 42(43), which are a minor component of the A beta in human cerebrospinal fluid and plasma, are critically important in AD where they deposit selectively in plaques of all kinds.

CONTEXT: Carotid artery intima-media thickness (CIMT) is a marker of coronary atherosclerosis and independently predicts cardiovascular events, which are increased in type 2 diabetes mellitus (DM). While studies of relatively short duration have suggested that thiazolidinediones such as pioglitazone might reduce progression of CIMT in persons with diabetes, the results of longer studies have been less clear. OBJECTIVE: To evaluate the effect of pioglitazone vs glimepiride on changes in CIMT of the common carotid artery in patients with type 2 DM. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, comparator-controlled, multicenter trial in patients with type 2 DM conducted at 28 clinical sites in the multiracial/ethnic Chicago metropolitan area between October 2003 and May 2006. The treatment period was 72 weeks (1-week follow-up). CIMT images were captured by a single ultrasonographer at 1 center and read by a single treatment-blinded reader using automated edge-detection technology. Participants were 462 adults (mean age, 60 [SD, 8.1] years; mean body mass index, 32 [SD, 5.1]) with type 2 DM (mean duration, 7.7 [SD, 7.2] years; mean glycosylated hemoglobin [HbA1c] value, 7.4% [SD, 1.0%]), either newly diagnosed or currently treated with diet and exercise, sulfonylurea, metformin, insulin, or a combination thereof. INTERVENTIONS: Pioglitazone hydrochloride (15-45 mg/d) or glimepiride (1-4 mg/d) as an active comparator. MAIN OUTCOME MEASURE: Absolute change from baseline to final visit in mean posterior-wall CIMT of the left and right common carotid arteries. RESULTS: Mean change in CIMT was less with pioglitazone vs glimepiride at all time points (weeks 24, 48, 72). At week 72, the primary end point of progression of mean CIMT was less with pioglitazone vs glimepiride (-0.001 mm vs +0.012 mm, respectively; difference, -0.013 mm; 95% confidence interval, -0.024 to -0.002; P = .02). Pioglitazone also slowed progression of maximum CIMT compared with glimepiride (0.002 mm vs 0.026 mm, respectively, at 72 weeks; difference, -0.024 mm; 95% confidence interval, -0.042 to -0.006; P = .008). The beneficial effect of pioglitazone on mean CIMT was similar across prespecified subgroups based on age, sex, systolic blood pressure, duration of DM, body mass index, HbA(1c) value, and statin use. CONCLUSION: Over an 18-month treatment period in patients with type 2 DM, pioglitazone slowed progression of CIMT compared with glimepiride. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00225264

Both whipping and emulsifying properties, the characteristic functional properties of soybean products, were investigated by using the commercial products in Japan. Whipping properties of the soybean products, expressed by foam expansion and foam stability, were found to correlate with water dispersible nitrogen, and the resultant foams were stable when the dissolved proteins were native. Thus, the native defatted soybean flour which contained native and soluble protein exhibited excellent whipping property. Emulsifying properties correlated positively with protein and negatively with fiber contents. As soybean protein isolate and soybean protein extract are rich in protein and poor in fiber contents, both of them show good emulsifying functions.

To produce a proton conductive and durable polymer electrolyte membrane for fuel cell applications, a series of sulfonated polyimide ionomers containing aliphatic groups both in the main and in the side chains have been synthesized. The title polyimide ionomers 1 with the ion exchange capacity of 1.78-2.33 mequiv/g were obtained by a typical polycondensation reaction as transparent, ductile, and flexible membranes. The proton conductivity of 1 was slightly lower than that of the perfluorinated ionomer (Nafion) below 100 degrees C, but comparable at higher temperature and 100% RH. The highest conductivity of 0.18 S cm(-)(1) was obtained for 1 at 140 degrees C. Ionomer 1 with high IEC and branched chemical structure exhibited improved proton conducting behavior without sacrificing membrane stability. Microscopic analyses revealed that smaller (<5 nm) and well-dispersed hydrophilic domains contribute to better proton conducting properties. Hydrogen and oxygen permeability of 1 was 1-2 orders of magnitude lower than that of Nafion under both dry and wet conditions. Fuel cell was fabricated with 1 membrane and operated at 80 degrees C and 0.2 A/cm(2) supplying H(2) and air both at 60% or 90% RH. Ionomer 1 membrane showed comparable performance to Nafion and was durable for 5000 h without distinct degradation.

You'll never walk alone? A gel actuator that can generate autonomous motility with a wormlike motion without external driving stimuli is produced. The autonomous motion is produced by dissipating the chemical energy of an oscillating reaction occurring inside the gel. Even though the gel is completely composed of synthetic polymer, it shows an autonomous motion as if it were “alive”. By coupling this with a ratchet mechanism, the gel walks by repeatedly bending and stretching itself like a looper (see figure). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2007/c0625_s.html or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.