Nanosilicon cluster-SiO x -C composites including nanosize Si particles were prepared by using the disproportionation of silicon mono-oxide and the polymerization of furfuryl alcohol. The applicability of nanosilicon composites as anode material for rechargeable lithium batteries was investigated on the basis of X-ray diffraction measurement, observation by transmission electron microscopy ͑TEM͒ and electrochemical studies. TEM analysis showed that Si clusters in the range of 2-10 nm were distributed homogeneously within silicon oxide phases. The nanosilicon composite anode had a large capacity of ca. 700 mAh/g and a long cycle life of Ͼ200 cycles. The improvement of cyclability is due to the nanosize Si particles and their uniform dispersion within the silicon oxide phase retained by the carbon matrix, which could effectively suppress the pulverizing of Si particles by the volume change during lithium insertion and extraction.

3-Hydroxyanthranilic acid (3-HAA), a metabolite of L-tryptophan, accumulates in monocyte-derived cells (THP-1), but not in other cell lines tested (MRC-9, H4, U373MG, Wil-NS), following immune stimulation that induces indoleamine-2,3-dioxygenase (IDO), a rate-limiting enzyme in the L-tryptophan kynurenine pathway. We examined whether metabolites of the L-tryptophan-kynurenine pathway act to induce apoptosis in monocytes/macrophages. Of the L-tryptophan metabolites tested, only 3-HAA at a concentration of 200 micromol/L was found to induce apoptosis in THP-1 and U937 cells. The addition of ferrous or manganese ions further enhanced apoptosis and free radical formation by 3-HAA in these two types of cells. The apoptotic response induced by 3-HAA was significantly attenuated by the addition of antioxidant, alpha-tocopherol or Trolox (a water-soluble analogue of vitamin E), and the xanthine oxidase inhibitor, allopurinol. In addition, the 3-HAA-induced apoptotic response was slightly attenuated by catalase, but not by superoxide dismutase (SOD), indicating that generation of hydrogen peroxide is involved in this response. Interferon-gamma (IFN-gamma), an inducer of IDO, potently induced apoptosis in THP-1 cells, but not in U937 cells, in the presence of ferrous or manganese ions. This different susceptibility to apoptosis inducer between THP-1 and U937 cells may depend on the capacity of the cells for 3-HAA synthesis following IDO induction by IFN-gamma. Furthermore, apoptosis was suppressed by cycloheximide in THP-1 cells, suggesting that newly synthesized proteins may be essential for apoptotic events. These results suggest that 3-HAA induces apoptosis in monocytes/macrophages under inflammatory or other pathophysiological conditions.

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Neurocalcin (molecular weight 23,000 and 24,000) is a Ca(2+)-binding protein with three putative Ca(2+)-binding domains and is present in large amounts in nervous tissues. Neurocalcin isoproteins separated by C18 reverse-phase column chromatography are insoluble in buffer solution and it is impossible to determine the dissociation constant of neurocalcin with Ca2+. To overcome this difficulty, recombinant neurocalcin was synthesized, based on one of the cDNAs of the neurocalcin isoproteins. Stoichiometric titration experiments, using recombinant neurocalcin, indicated that this protein bound 2 mol Ca2+/mol protein and that the apparent dissociation constant for Ca2+ was 2.2 mumol/l, suggesting that neurocalcin plays a physiological role in cellular function. Immunoblotting showed that neurocalcin is present in the bovine adrenal gland in addition to the nervous tissues. Neurocalcin, identified by immunoblotting, was purified from the bovine adrenal gland. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of neurocalcin from the bovine brain showed 23 kDa and 24 kDa double bands, while SDS-PAGE of neurocalcin from the adrenal gland showed a single band of apparently 24 kDa, suggesting that the expression of neurocalcin isoproteins differs from tissue to tissue. The content of neurocalcin in the adrenal gland was 10 micrograms protein/100 g wet tissue. Immunohistochemical analysis showed the occurrence of neurocalcin in zona glomerulosa and adrenal medulla but not in zona fasciculata or zona reticularis. The restricted localization of neurocalcin in the adrenal gland suggests that a similar Ca2+signal pathway may be present in zona glomerulosa a nd the adrenal medulla.