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961.
962.
We developed a novel chemiluminescent assay of β-D -galactosidase (β-gal) based on the chemiluminescence of indole. 5-Bromo-4-chloro-3-indolyl-β-D -galactopyranoside (X-gal) was used as a substrate for β-gal and also as a light emitter. X-gal was hydrolysed by β-gal to liberate free indoxyl, followed by oxidation to indigo dye, and simultaneously produces hydrogen peroxide (H2O2). H2O2 reacts with the residual X-gal in the presence of horseradish peroxidase (HRP) to emit light. The measurable range of β-gal obtained by this method was 6 × 10−14 mol/L to 6 × 10−11 mol/L; the detection limit was 3 amol/assay. This chemiluminescent assay could be applied to an enzyme immunoassay of thyroxine using β-gal as the enzyme label. © 1998 John Wiley & Sons, Ltd. 相似文献
963.
Masatoshi Kakizaki Yuichiro Yamamoto Shunya Nakayama Kazuaki Kameda Etsuko Nagashima Masatoshi Ito Takashi Suyama Yumi Matsuzaki Tetsuhiro Chiba Hideaki Sumiyoshi Yutaka Inagaki Ai Kotani 《Cell death & disease》2021,12(11)
Acute liver injury (ALI) induced by chemicals or viruses can progress rapidly to acute liver failure (ALF), often resulting in death of patients without liver transplantation. Since liver transplantation is limited due to a paucity of donors, expensive surgical costs, and severe immune rejection, novel therapies are required to treat liver injury. Extracellular vesicles (EVs) are used for cellular communication, carrying RNAs, proteins, and lipids and delivering them intercellularly after being endocytosed by target cells. Recently, it was reported that EVs secreted from human hepatocytes have an ability to modulate the immune responses; however, these roles of EVs secreted from human hepatocytes were studied only with in vitro experiments. In the present study, we evidenced that EVs secreted from human hepatocytes attenuated the CCL4-induced ALI by inhibiting the recruitment of monocytes through downregulation of chemokine receptor in the bone marrow and recruitment of neutrophils through the reduction of C-X-C motif chemokine ligand 1 (CXCL1) and CXCL2 expression levels in the liver.Subject terms: Acute inflammation, Liver diseases 相似文献
964.
Chiaki Kambayashi Ryosuke Kakehashi Yusuke Sato Hideaki Mizuno Hideyuki Tanabe Andolalao Rakotoarison Sven Künzel Nobuaki Furuno Kazuhiko Ohshima Yoshinori Kumazawa Zoltn T. Nagy Akira Mori Allen Allison Stephen C. Donnellan Hidetoshi Ota Masaki Hoso Tetsuya Yanagida Hiroshi Sato Miguel Vences Atsushi Kurabayashi 《Molecular biology and evolution》2022,39(4)
Horizontal transfer (HT) of genes between multicellular animals, once thought to be extremely rare, is being more commonly detected, but its global geographic trend and transfer mechanism have not been investigated. We discovered a unique HT pattern of Bovine-B (BovB) LINE retrotransposons in vertebrates, with a bizarre transfer direction from predators (snakes) to their prey (frogs). At least 54 instances of BovB HT were detected, which we estimate to have occurred across time between 85 and 1.3 Ma. Using comprehensive transcontinental sampling, our study demonstrates that BovB HT is highly prevalent in one geographical region, Madagascar, suggesting important regional differences in the occurrence of HTs. We discovered parasite vectors that may plausibly transmit BovB and found that the proportion of BovB-positive parasites is also high in Madagascar where BovB thus might be physically transported by parasites to diverse vertebrates, potentially including humans. Remarkably, in two frog lineages, BovB HT occurred after migration from a non-HT area (Africa) to the HT hotspot (Madagascar). These results provide a novel perspective on how the prevalence of parasites influences the occurrence of HT in a region, similar to pathogens and their vectors in some endemic diseases. 相似文献
965.
Nobutoshi Ichise Naoki Morita Tamotsu Hoshino Kosei Kawasaki Isao Yumoto Hidetoshi Okuyama 《Applied microbiology》1999,65(1):73-79
A possible mechanism of resistance to hydrogen peroxide (H2O2) in Vibrio rumoiensis, isolated from the H2O2-rich drain pool of a fish processing plant, was examined. When V. rumoiensis cells were inoculated into medium containing either 5 mM or no H2O2, they grew in similar manners. A spontaneous mutant strain, S-4, derived from V. rumoiensis and lacking catalase activity did not grow at all in the presence of 5 mM H2O2. These results suggest that catalase is inevitably involved in the resistance and survival of V. rumoiensis in the presence of H2O2. Catalase activity was constitutively present in V. rumoiensis cells grown in the absence of H2O2, and its occurrence was dependent on the age of the cells, a characteristic which is observed for the HP II-type catalase of Escherichia coli. The presence of the HP II-type catalase in V. rumoiensis cells was evidenced by partial sequencing of the gene encoding the HP II-type catalase from this organism. A notable difference between V. rumoiensis and E. coli is that catalase is accumulated at very high levels (~2% of the total soluble proteins) in V. rumoiensis, in contrast to the case for E. coli. When V. rumoiensis cells which had been exposed to 5 mM H2O2 were centrifuged, most intracellular proteins, including catalase, were recovered in the medium. On the other hand, when V. rumoiensis cells were grown on plates containing various concentrations of H2O2, individual cells had a colony-forming ability inferior to those of E. coli, Bacillus subtilis, and Vibrio parahaemolyticus. Thus, it is suggested that when V. rumoiensis cells are exposed to high concentrations of H2O2, most cells will immediately be broken by H2O2. In addition, the cells which have had little or no damage will start to grow in a medium where almost all H2O2 has been decomposed by the catalase released from broken cells. 相似文献
966.
D R Light C B Glaser M Betts E Blasko E Campbell J H Clarke M McCaman K McLean M Nagashima J F Parkinson G Rumennik T Young J Morser 《European journal of biochemistry》1999,262(2):522-533
Thrombomodulin (TM) is a cofactor for protein C activation by thrombin and each residue of a consensus Ca2+ site in the sixth epidermal growth factor domain (EGF6) is essential for this cofactor activity [Nagashima, M., Lundh, E., Leonard, J.C., Morser, J. & Parkinson, J.F. (1993) J. Biol. Chem. 268, 2888-2892]. Three soluble analogs of the extracellular domain of TM, solulin (Glu4-Pro490), TME1-6 (Cys227-Cys462) and TMEi4-6 (Val345-Cys462) were prepared for equilibrium dialysis experiments by exhaustive dialysis against Ca2+-depleted buffer. However, all three analogs still contained one tightly bound Ca2+ (Kd approximately 2 microm), which could only be removed by EDTA. Epitope mapping with Ca2+-dependent monoclonal antibodies to EGF6 provided further localization of this tight Ca2+ site. Equilibrium dialysis of the soluble TM analogs in [45Ca2+] between 10 and 200 microm revealed a second Ca2+ site (Kd = 30 +/- 10 microm) in both solulin and TME1-6, but not in TMEi4-6. Ca2+ binding to this second site was unaffected by bound thrombin and we attribute it to the consensus Ca2+ site in EGF3. A 75-fold decrease in the binding affinity of thrombin to TM was observed with immobilized solulin treated with EDTA to remove the high affinity Ca2+ by measuring kassoc and kdiss rates in a BIAcoretrade mark instrument. Ca2+-dependent conformational transitions detected by CD spectroscopy in the far UV indicate a more ordered structure upon Ca2+ binding. Bound Ca2+ stabilized soluble TM against protease digestion at a trypsin-like protease-sensitive site between Arg456 and His457 in EGF6 compared with protease treatment in EDTA. Finally, TM containing EGF domains 4-6, but lacking the interdomain loop between EGF3 and 4 (TME4-6), has an identical Ca2+ dependence for the activation of protein C as found for TMEi4-6, indicating this interdomain loop is not involved in Ca2+ binding. 相似文献
967.
Mika Tanaka Akio Ueno Kosei Kawasaki Isao Yumoto Satoru Ohgiya Tamotsu Hoshino Kozo Ishizaki Hidetoshi Okuyama Naoki Morita 《Biotechnology letters》1999,21(11):939-945
A 40-kbp DNA fragment was isolated from the cosmid library of Vibrio marinus strain MP-1. Among the 22 putative open reading frames (ORFs) in this fragment, ORFs 8, 9, 10 and 11 had high homology with ORFs 5, 6, 7 and 8 of the eicosapentaenoic acid biosynthesis gene cluster, respectively. Then, we speculate that these ORFs are responsible for docosahexaenoic acid biosynthesis in this bacterium. 相似文献
968.
Noaki Morita Akio Ueno Mika Tamaka Satoru Ohgiya Tamotsu Hoshino Kosei Kawasaki Isao Yumoto Kozo Ishizaki Hidetoshi Okuyama 《Biotechnology letters》1999,21(7):641-646
A cluster of genes involved in fatty acid biosynthesis (fab) was isolated from docosahexaenoic acid (DHA)-producing Vibrio marinus strain MP-1. This fab gene cluster included five genes highly homologous to the Escherichia coli counterparts, and their order in the cluster was the same with that of the E. coli fab gene cluster except that the latter included the additional fabH gene. These fab genes should be involved in early steps of DHA biosynthesis in V. marinus strain MP-1. 相似文献
969.
The concentrations of trace elements in several mollusk, arthropod, echinoderm, and tunicata species were determined by photon
activation analysis. The samples were freeze-dried, pulverized by a mill, and fractionated through a 200-mesh sieve. Three
standard materials were used for comparative standards: NIST SRM-1566a Oyster Tissue, NIST SRM-1577b Bovine Liver, and NRCC
TORT-1 Lobster. The samples and comparator standards were sealed in silica tubes and irradiated for 3 h by 30-MeV bremsstrahlung
from a linear accelerator at Tohoku University. By measuring gamma-ray spectra, the concentrations of 16 elements (As, Br,
Ca, Cr, Cu, Fe, I, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sr, and Zn) were determined. 相似文献
970.
K Nagashima G W Mack A Haskell T Nishiyasu E R Nadel 《Journal of applied physiology》1999,86(3):867-873
To test the hypothesis that exercise-induced hypervolemia is a posture-dependent process, we measured plasma volume, plasma albumin content, and renal function in seven healthy subjects for 22 h after single upright (Up) or supine (Sup) intense (85% peak oxygen consumption rate) exercise. This posture was maintained for 5 h after exercise. Plasma volume decreased during exercise but returned to control levels by 5 h of recovery in both postures. By 22 h of recovery, plasma volume increased 2.4 +/- 0.8 ml/kg in Up but decreased 2.1 +/- 0.8 ml/kg in Sup. The plasma volume expansion in Up was accompanied by an increase in plasma albumin content (0.11 +/- 0.04 g/kg; P < 0.05). Plasma albumin content was unchanged in Sup. Urine volume and sodium clearance were lower in Up than Sup (P < 0.05) by 5 h of recovery. These data suggest that increased plasma albumin content contributes to the acute phase of exercise-induced hypervolemia. More importantly, the mechanism by which exercise influences the distribution of albumin between extra- and intravascular stores after exercise is altered by posture and is unknown. We speculate that factors associated with postural changes (e.g., central venous pressure) modify the increase in plasma albumin content and the plasma volume expansion after exercise. 相似文献