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941.
Isaka K Suwa Y Kimura Y Yamagishi T Sumino T Tsuneda S 《Applied microbiology and biotechnology》2008,81(2):379-385
Methanol inhibition of anaerobic ammonium oxidation (anammox) activity was characterized. An enrichment culture entrapped
in a polyethylene glycol gel carrier was designed for practical uses of wastewater treatment. Batch experiments demonstrated
that anammox activity decreased with increases in methanol concentration, and relative activity reached to 29% of the maximum
when 5 mM methanol was added. Also, batch experiments were conducted using anammox sludge without immobilization. Anammox
activity was evaluated by quantifying 14N15N (29N) emission by combined gas chromatography-quadrupole mass spectrometry, and the anammox activity was found to be almost as
sensitive to methanol as in the earlier trials in which gel carriers were used. These results indicated that methanol inhibition
was less severe than previous studies. When methanol was added in the influent of continuous feeding system, relative activity
was decreased to 46% after 80 h. Although the addition was halted, afterwards the anammox activity was not resumed in another
19 days of cultivation, suggesting that methanol inhibition to anammox activity was irreversible. It is notable that methanol
inhibition was not observed if anammox activity was quiescent when substrate for anammox was not supplied. These results suggest
that methanol itself is not inhibitory and may not directly inhibit the anammox activity. 相似文献
942.
Okubo S Asakura T Okubo K Abe K Misaka T Akita T Abe K 《Journal of plant physiology》2008,165(18):1964-1969
Neoculin is a sweet protein with a taste-modifying activity of converting sourness to sweetness. It occurs in the fruits of Curculigo latifolia, a wild plant found in tropical Asia. We successfully cultivated the plant and evaluated the production of neoculin. The neoculin content of the fruit was high for 10 weeks after flowering, following which the yield decreased gradually. The optimal period for harvesting the fruits with sensory activity coincided with this 10-week peak period during which the amount of neoculin was 1-3mg in the whole fruit and 1.3mg/g of pulp. Immunohistochemical staining showed that neoculin occurred in the whole fruit, especially at the basal portion. Although it is known that neoculin comprises an acidic subunit (NAS) with an N-glycosylated moiety and a basic subunit (NBS), protein gel blot analysis revealed the presence of a non-glycosylated NAS species. This suggests the presence of multiple NAS-NBS heterodimers in our cultivar. 相似文献
943.
Oliveira GA Tahara EB Gombert AK Barros MH Kowaltowski AJ 《Journal of bioenergetics and biomembranes》2008,40(4):381-388
Calorie restriction is a dietary regimen capable of extending life span in a variety of multicellular organisms. A yeast model
of calorie restriction has been developed in which limiting the concentration of glucose in the growth media of Saccharomyces cerevisiae leads to enhanced replicative and chronological longevity. Since S. cerevisiae are Crabtree-positive cells that present repression of aerobic catabolism when grown in high glucose concentrations, we investigated
if this phenomenon participates in life span regulation in yeast. S. cerevisiae only exhibited an increase in chronological life span when incubated in limited concentrations of glucose. Limitation of
galactose, raffinose or glycerol plus ethanol as substrates did not enhance life span. Furthermore, in Kluyveromyces lactis, a Crabtree-negative yeast, glucose limitation did not promote an enhancement of respiratory capacity nor a decrease in reactive
oxygen species formation, as is characteristic of conditions of caloric restriction in S. cerevisiae. In addition, K. lactis did not present an increase in longevity when incubated in lower glucose concentrations. Altogether, our results indicate
that release from repression of aerobic catabolism is essential for the beneficial effects of glucose limitation in the yeast
calorie restriction model. Potential parallels between these changes in yeast and hormonal regulation of respiratory rates
in animals are discussed.
G. A. Oliveira and E. B. Tahara contributed equally to this work. 相似文献
944.
Abad L Okabe S Shibayama M Kudo H Saiki S Aranilla C Relleve L de la Rosa A 《International journal of biological macromolecules》2008,42(1):55-61
The conformational associative properties of kappa-, iota-, and lambda-carrageenan and agar with irradiation dose were studied by dynamic light scattering. The random scission of the carrageenans and agar by gamma irradiation resulted in the formation of polydispersed lower molecular weight fragments. At high doses, the system moves towards uniformity. Conformational change from coil to helix was observed in all carrageenans and agar at doses up to 100 kGy. The conformational change in lambda-carrageenan may be due to the irregular and hybrid structure of this polysaccharide. Only agar and lambda-carrageenan still undergo conformational transition at a high dose of 200 kGy. Gelation is observed for kappa-, iota-carrageenan up to a dose of 50 kGy while gelation is still observed at 100 kGy for agar. Increase in the hydrodynamic radius with decreasing temperatures for the non-irradiated carrageenans follows this order: lambda-carrageenan>kappa-carrageenan>iota-carrageenan. Slight increases in hydrodynamic radius were observed with irradiation. 相似文献
945.
We investigated the effect of magnesium supplementation on zinc distribution in rats given excess calcium as carbonate. Rats
were given a control diet (5 g/kg calcium and 0.5 g/kg magnesium), a high calcium diet (HC, 25 g/kg calcium and 0.5 g/kg magnesium)
or the high calcium diet supplied with magnesium (HCM, 25 g/kg calcium and 2.5 g/kg magnesium) for 4 weeks. Calcium carbonate
and magnesium oxide were used for increasing these mineral concentrations in diets. Although feed intake did not differ among
the groups, the excess calcium suppressed feed efficiency, irrespective of dietary magnesium concentration. Femoral magnesium
concentration was lower in the HC group than in the control and the HCM groups. Femoral zinc concentration was higher in the
HC group and the HCM group than in the control group. The zinc concentration in the kidney was lower in the HC group and the
HCM group than in the control group. The excess calcium did not affect zinc concentration in plasma and other tissues such
as the liver, testis, and spleen, irrespective of dietary magnesium. These results suggest that the increasing bone zinc and
the decreasing renal zinc do not result from magnesium insufficiency in rats given excess calcium as carbonate. 相似文献
946.
Katanosaka Y Bao JH Komatsu T Suemori T Yamada A Mohri S Naruse K 《Journal of biotechnology》2008,133(1):82-89
Human vascular endothelial cells form the interface between the bloodstream and vessel walls and are continuously subjected to mechanical stimulation. When endothelial cells are stretched cyclically, along one axis, they align perpendicular to the axis of stretch. We previously reported that applying a cyclic, uni-axial strain to cells induced tyrosine phosphorylation of focal adhesion kinase and stimulated mitogen-activated protein kinase. However, it is difficult to quantify and analyze the spatial distribution of tyrosine phosphorylation in these cells, as they form focal adhesions randomly. In this study, we developed a system to overcome this problem by preparing individual, uniform, patterned cells that could be stretched cyclically and uni-axially. We constructed polydimethylsiloxane stretch chambers and used microcontact printing technology to imprint a pattern of 2 microm fibronectin dots (10 lines x 10 columns in a 38 microm square) before seeding them with human umbilical vein endothelial cells (HUVEC). We found that most HUVEC attached to the patterned dots after 2h and were similar in size and morphology, based on phase-contrast microscopy. In this system we were able to statistically analyze tyrosine phosphorylation and actin polymerization in these patterned cells, when subjected to a cyclic, uni-axial strain, using fluorescent microscopy. 相似文献
947.
Matsuda C Kameyama K Suzuki A Mishima W Yamaji S Okamoto H Nishino I Hayashi YK 《FEBS letters》2008,582(8):1189-1196
Affixin/beta-parvin is an integrin-linked kinase (ILK)-binding focal adhesion protein highly expressed in skeletal muscle and heart. To elucidate the possible role of affixin in skeletal muscle, we established stable C2C12 cell line expressing T7-tagged human affixin (C2C12-affixin cells). Exogenous expression of affixin promotes lamellipodium formation where affixin, ILK alphap21-activated kinase (PAK)-interactive exchange factor (PIX) and betaPIX accumulate. The association of affixin and betaPIX was confirmed by immunoprecipitation and pull down assay. In C2C12-affixin cells, an increased level of activated Rac1 but not Cdc42 was observed, and mutant betaPIX lacking guanine nucleotide exchange factor activity inhibited lamellipodium formation. These results suggest that affixin is involved in reorganization of subsarcolemmal cytoskeletal actin by activation of Rac1 through alpha and betaPIXs in skeletal muscle. 相似文献
948.
Makino N Toyofuku T Takegahara N Takamatsu H Okuno T Nakagawa Y Kang S Nojima S Hori M Kikutani H Kumanogoh A 《FEBS letters》2008,582(28):3935-3940
Dilated cardiomyopathy often results from autoimmunity triggered by microbial infections during myocarditis. However, it remains unclear how immunological disorders are implicated in pathogenesis of autoimmune myocarditis. Here, we demonstrated that Sema4A, a class IV semaphorin, plays key roles in experimental autoimmune myocarditis (EAM). Dendritic cells pulsed with myosin heavy chain-α peptides induced severe myocarditis in wild-type mice, but not in Sema4A-deficient mice. In adoptive transfer experiments, CD4+ T-cells from wild-type mice induced severe myocarditis, while CD4+ T-cells from Sema4A-deficient mice exhibited considerably attenuated myocarditis. Our results indicated that Sema4A is critically involved in EAM by regulating differentiation of T-cells. 相似文献
949.
Inouye S 《Journal of biochemistry》2008,143(5):711-717
The cDNA for an isotype of clytin, a calcium-binding photoprotein from the luminous jellyfish Clytia gregarium, was identified and named clytin-II. The histidine-tagged apoprotein of clytin-II expressed into the periplasmic space of Escherichia coli cells was isolated by nickel chelate affinity chromatography. Recombinant clytin-II regenerated from apoprotein by incubation with coelenterazine was purified. The yield of purified clytin-II was 13 mg from 2 l of cultured cells with purity >95%. The luminescence properties of clytin-II were characterized by comparison with clytin-I and aequorin, and semi-synthetic clytin-II was also prepared. The initial luminescence intensity of clytin-II triggered by Ca(2+) was 4.5 times higher than that of clytin-I and aequorin, but the luminescence capacity was close to clytin-I and aequorin. Thus, clytin-II is a useful protein, showing high sensitivity in the signal-to-noise ratio of luminescence intensity. 相似文献
950.
Ikeda E Yagi K Kojima M Yagyuu T Ohshima A Sobajima S Tadokoro M Katsube Y Isoda K Kondoh M Kawase M Go MJ Adachi H Yokota Y Kirita T Ohgushi H 《Differentiation; research in biological diversity》2008,76(5):495-505
Abstract Adult stem cells have been reported to exist in various tissues. The isolation of high-quality human stem cells that can be used for regeneration of fatal deseases from accessible resources is an important advance in stem cell research. In the present study, we identified a novel stem cell, which we named tooth germ progenitor cells (TGPCs), from discarded third molar, commonly called as wisdom teeth. We demonstrated the characterization and distinctiveness of the TGPCs, and found that TGPCs showed high proliferation activity and capability to differentiate in vitro into cells of three germ layers including osteoblasts, neural cells, and hepatocytes. TGPCs were examined by the transplantation into a carbon tetrachloride (CCl4 )-treated liver injured rat to determine whether this novel cell source might be useful for cell-based therapy to treat liver diseases. The successful engraftment of the TGPCs was demonstrated by PKH26 fluorescence in the recipient's rat as to liver at 4 weeks after transplantation. The TGPCs prevented the progression of liver fibrosis in the liver of CCl4 -treated rats and contributed to the restoration of liver function, as assessed by the measurement of hepatic serum markers aspartate aminotransferase and alanine aminotransferase. Furthermore, the liver functions, observed by the levels of serum bilirubin and albumin, appeared to be improved following transplantation of TGPCs. These findings suggest that multipotent TGPCs are one of the candidates for cell-based therapy to treat liver diseases and offer unprecedented opportunities for developing therapies in treating tissue repair and regeneration. 相似文献