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21.
Norio Tada Takuya Sakamoto Akihiko Kagami Keiko Mochizuki Kosei Kurosaka 《Molecular and cellular biochemistry》1993,119(1-2):171-178
Human plasmain vitro inhibits the growth of coagulase negative staphylococci,S. epidermidis, which may be pathogenic in the immunocompromised host. To determine the antimicrobial components, serum was fractionated by column chromatography, which revealed that elution areas where lipoproteins can be yielded had high antimicrobial activity againstS. epidermidis. Therefore, lipoprotein fractions, including very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL), were separated by ultracentrifugation and incubated withS. epidermidis. All 3 lipoprotein fractions suppressed bacterial growth within the first 3 h but VLDL enhanced bacterial growth after 9 h of incubation compared with the control. HDL, however, inhibited bacterial growth throughout 21 h of incubation.To confirm these results, serum from healthy volunteers was separated by ion exchange column chromatography and again by HPLC to purify the antimicrobial fraction. In the protein analysis with gradient polyacrylamide-SDS gel, apolipoprotein Al (apo Al), which is a major apolipoprotein of HDL, was detected in the antimicrobial fraction. Therefore, this fraction was loaded onto an immunoaffinity column coupled with the anti-apo Al monoclonal antibody (Mab). Unbound fraction had no antimicrobial activity, but anti-S. epidermidis activity was recovered from the bound fraction which consisted mainly of apo Al, All and apo C in protein composition.These results indicated that the antimicrobial activity was associated with the apo Al-containing lipoprotein particles (HDL). This property of HDL may directly affect bacterial growth and promote the self-defense mechanisms of normal and immunocompromised individuals. 相似文献
22.
Tokuo Ogawa Junichi Sugenoya Norikazu Ohnishi Keiko Natsume Kazuno Imai Yoshikazu Kandori Akira Ishizuka Atsushi Osada 《European journal of applied physiology and occupational physiology》1993,67(4):354-359
We have examined the nonparallel changes in tampanic membrane temperatures (T
ty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the T
ty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in T
ty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the T
ty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in T
ty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the T
ty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using 99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in T
ty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation. 相似文献
23.
The concanavalin A staining of cellular glycoproteins and thedirect analysis of their sugar chains released by hydrazinolysisrevealed that the processing of N-linked sugar chains of someglycoproteins is suppressed by exposure of mouse monocytoidcells P388D1 to dimethyl sulphoxide, which can induce Fc receptor-mediatedphagocytosis. To elucidate the significance of altered glycosylationin inducing phagocytosis, the effects of exposure of the cellsto processing inhibitors (swainsonine and castanospermine) wereexamined and it was found that the cells are induced to acquirean ability to ingest IgG-coated sheep red blood cells, dependingon the dose of the inhibitors and incubation time. Analysisof the N-linked sugar chains liberated from cellular glycoproteinsby hydrazinolysis confirmed that the processing of the sugarchains is suppressed by the two inhibitors as expected. Sinceno significant alteration was induced in protein synthesis andDNA synthesis after exposure to the inhibitors, it is suggestedthat the altered glycosylation of cellular glycoproteins mayhave some direct role in the induction of Fc receptor-mediatedphagocytosis. The inhibitors did not affect the binding of theIgG-coated red blood cells to Fc receptors on the cells, non-specificphagocytosis of latex beads, and the contents of lysosomal enzymes,ß-glucuronidase and acid phosphatase. These resultssuggest that the glycosylation status of cellular glycoproteinsinfluences some specific processes involved in the ingestionof the ligands bound to Fc receptors. castanospermine macrophages phagocytosis swainsonine 相似文献
24.
Hisao Yamaguchi Keiko Hosokawa Zheng-Lin Jiang Akira Takahashi Toshitaka Ikehara Hiroshi Miyamoto 《Journal of cellular biochemistry》1993,53(1):13-20
Cell cycle progression of synchronized HeLa cells was studied by measuring labeling of the nuclei with [3H]thymidine. The progression was arrested in a chemically defined medium in which K+ was replaced by Rb+ (Rb-CDM) but was restored upon addition of insulin and/or low density lipoprotein (LDL). Cells started DNA synthesis 12 hr after addition of insulin and/or LDL, regardless of the time of arrest, suggesting their arrest early in the G1 phase. After incubation of cells in Rb-CDM containing insulin or LDL singly for 3, 6, or 9 hr, replacement of the medium by that without an addition resulted in marked delay in entry of cells into the S phase, but in its replacement by medium containing both agents, the delay was insignificant. Synthesis of bulk protein, estimated as increase in the cell volume, was not strongly inhibited. From these results we conclude that cell cycle progression of HeLa cells in K?-depleted CDM is arrested early in the G1 phase and that the arrest is due to lack of some protein(s) required for entry into the S phase that is synthesized in the early G1 phase. 相似文献
25.
26.
Takehiko Nohmi Masami Yamada Michiko Matsui Keiko Matsui Masahiko Watanabe Toshio Sofuni 《Molecular & general genetics : MGG》1995,247(1):7-16
Expression of the umuDC operon is required for UV and most chemical mutagenesis in Escherichia coli. The closely related species Salmonella typhimurium has two sets of umuDC-like operons, umuDC
ST on the chromosome and samAB on a 60-MDa cryptic plasmid. The roles of theumuDC-like operons in chemically induced frameshift mutagenesis of the hisD3052 allele of S. typhimurium were investigated. Introduction of a pBR322-derived plasmid carrying umuDCST increased the rate of reversion of hisD3052, following treatment with 1-nitropyrene (1-NP) or 1,8-dinitropyrene (1,-8DNP) tenfold and fivefold, respectively, whereas it did not substantially increase the rate of reversion induced by other frameshift mutagens, i.e. 2-nitrofluorene (2NF) and 2-amino- 3-methyldipyrido[1,2-a:3 ,2-d]imi-dazole (Glu-P-1). Introduction of a pBR322-derived plasmid carrying samAB did not increase the incidence of reversion of hisD3052 observed with any of the mutagens examined. Deletion of umuDC
STSubstantially lowered the reversion rate induced by l-NP or 1,8-DNP, but it did not affect reversion induced by 2-NF, Glu-P-1 or N-hydroxyacetylaminofluorene (N-OH-AAF). Deletion of samAB had little impact on reversion incidence induced by any of the five frameshift mutagens. DNA amplification using the polymerase chain reaction technique followed by restriction enzyme analysis using BssHII, suggested that the mutations induced by the five frameshift mutagens were all CG deletions at the CGCGCGCG sequence in hisD3052. These results suggest that umuDCST, but not samAB, is involved in the -2 frameshift mutagenesis induced by l-NP and 1,8-DNP at the repetitive CG sequence, whereas neither operon participates in induction of the same type of mutations by 2-NF, Glu-P-1 or N-OH-AAF. 相似文献
27.
Wataru Shibata Hiroharu Banno Yukihiro Ito Keiko Hirano Kenji Irie Shoji Usami Chiyoko Machida Yasunori Machida 《Molecular & general genetics : MGG》1995,246(4):401-410
A cDNA (cNPK2) that encodes a protein of 518 amino acids was isolated from a library prepared from poly(A)+ RNAs of tobacco cells in suspension culture. The N-terminal half of the predicted NPK2 protein is similar in amino acid sequence to the catalytic domains of kinases that activate mitogen-activated protein kinases (designated here MAPKKs) from various animals and to those of yeast homologs of MAPKKs. The N-terminal domain of NPK2 was produced as a fusion protein in Escherichia coli, and the purified fusion protein was found to be capable of autophosphorylation of threonine and serine residues. These results indicate that the N-terminal domain of NPK2 has activity of a serine/threonine protein kinase. Southern blot analysis showed that genomic DNAs from various plant species, including Arabidopsis thaliana and sweet potato, hybridized strongly with cNPK2, indicating that these plants also have genes that are closely related to the gene for NPK2. The structural similarity between the catalytic domain of NPK2 and those of MAPKKs and their homologs suggests that tobacco NPK2 corresponds to MAPKKs of other organisms. Given the existence of plant homologs of an MAP kinase and tobacco NPK1, which is structurally and functionally homologous to one of the activator kinases of yeast homologs of MAPKK (MAPKKKs), it seems likely that a signal transduction pathway mediated by a protein kinase cascade that is analogous to the MAP kinase cascades proposed in yeasts and animals, is also conserved in plants. 相似文献
28.
Kenji Hara Henneke Pangkey Kiyoshi Osatomi Keiko Yatsuda Atsushi Hagiwara Katsuyasu Tachibana Tadashi Ishihara 《Hydrobiologia》1997,358(1-3):89-94
We examined some characteristics of hydrolyticenzymes, especially -1,3-glucanase, to obtain theinformation of cell wall lytic enzymes forrotifers.Crude enzyme (ammonium sulfate fraction) of rotifershydrolyzed starch, -1,3-glucan, glycol chitinand CM-cellulose. Optimum pH for hydrolysis ofstarch and CM-cellulose was 6.5, and that for -1,3glucan and glycol chitin was pH 6.0. Pectic acid,xylan and agarose were not hydrolyzed at pH 3–10.-1,3 glucanase was purified about 73-fold from crudeenzyme by ion-exchange chromatography and gelfiltration. Optimum pH and temperature of the enzymewere 6 and 60 °C, respectively. The molecular weight ofthe enzyme was estimated about 260 kDa by gelfiltration. The enzyme was inhibited byHgCl2 and MnCl_2. 相似文献
29.
Keiko Yamamura Tsunehisa Sakurai Kohji Yano Takashi Osada Toshitaka Nabeshima 《Microbiology and immunology》1995,39(11):895-896
To examine the efficacy of sisomicin (SISO) incorporated into fibrin glue (FG) for the prevention of graft infection in animal models, the susceptibility to infection of Dacron grafts (control) and SISO-FG Dacron grafts following the inoculation of Staphylococcus aureus or S. epidermidis was compared. The results showed that SISO-FG Dacron grafts displayed resistance to graft infection. 相似文献
30.
Immunochemical characterisation and epitope mapping of a novel fimbrial protein (Pg-II fimbria) of Porphyromonas gingivalis 总被引:2,自引:0,他引:2
Tomohiko Ogawa Kenji Yasuda Keiko Yamada Hideharu Mori Keiko Ochiai Mamoru Hasegawa 《FEMS immunology and medical microbiology》1995,11(3):247-255
Abstract Mouse monoclonal antibody (mAb) Pgf-II specific for a 72-kDa major cell-surface protein (72K-CSP) derived from Porphyromonas gingivalis OMZ 409 was prepared. Immunoblotting analysis revealed that mAb Pgf-II reacted with 72K-CSP but not with 41-kDa fimbrial subunit protein (41K-fimbrilin) derived from P. gingivalis 381. Electron microscopic observation revealed that P. gingivalis OMZ 409 possessed peritrichous, thin fimbriae on their surface. Immunogold electron microscopy also demonstrated that mAb Pgf-II bound to the 72K-CSP examined with the gold particles arranged along the fibril array originating from the cell surface of the bacteria. These findings suggested that P. gingivalis 72K-CSP was identifiable as another fimbriae (termed Pg-II fimbriae) different from the fimbriae (termed Pg-I fimbriae) composed of a 41K-fimbrilin. Using multipin peptide synthesis technology, 102 sequential overlapping peptides covering the entire 514 amino-acid stretch of Pg-II fimbriae were synthesised. Seven immunodominant regions within Pg-II fimbrial protein molecule, which definitely reacted with the serum of patients with periodontal diseases, were detected. 相似文献