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871.
872.
Ogata Y Sakurai T Nakao S Kuboyama N Moriwaki K Furuyama S Sugiya H 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2002,131(3):315-322
4-Bromophenacyl bromide (BPB) is generally used as a phospholipase A(2) (PLA2) inhibitor. In the present study, we demonstrate that BPB induces Ca2+ influx in human gingival fibroblasts. In fura-2-loaded human gingival fibroblasts, BPB evoked a transient increase in intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. The BPB-induced Ca2+ mobilization was also shown in a single fluo-3-loaded-fibroblast. The BPB-induced increase in [Ca2+]i was completely abolished by the elimination of the external Ca2+. Ca2+ influx induced by the Ca2+-mobilizing agonist histamine was markedly enhanced in the presence of BPB. These suggest that the BPB-induced Ca2+ mobilization is due to the influx of extracellular Ca2+. However, it is unlikely that the effect of BPB is dependent on the inhibition of PLA2 activity, because other PLA2 inhibitors, such as AACOCF3, quinacrine dihydrochloride and manoalide, failed to induce Ca2+ mobilization. Chemical compounds similar to BPB, but which have no -CH2-Br at position 1 in the benzene ring failed to evoke Ca2+ mobilization, indicating that the position of -CH2--Br in BPB is important for causing the Ca2+ influx. 相似文献
873.
Female spawning strategy in Rhinogobius sp. OR: how do females deposit their eggs in the nest? 总被引:1,自引:1,他引:0
We tried to elucidate how females of a paternal nest brooding goby Rhinogohius sp. OR deposit their eggs in a nest, using a marking technique for live eggs under laboratory conditions in which male somatic
condition, nest space, and mating pattern (monogamous or bigamous) were controlled. Whether females rejected mating was independent
of either male quality, such as body size and somatic condition, or nest space. In a situation in which two females were allowed
to spawn sequentially with a male, however, females rejected mating at a higher rate when they were the first to spawn than
when they were the second to spawn; this is because eggs from first females were more vulnerable to cannibalism by parental
males and second females. Even when nest space was limited and thus was occupied by eggs from the first females, second females
could deposit all their eggs in the nest by using the minute interspace of existing eggs. In the presence of the parental
male, such a female seemed less likely to suffer a cost from increased egg mortality due to crowdedness, still holding the
advantage of being the second spawner. Finally, we extrapolated the field breeding ecology of this fish from the laboratory
data. It was suggested that a single monolayer brood of the same age usually consisted of eggs from multiple females and thus
the mating pattern would be more polygynous than previously expected.
Received: March 6, 2002 / Revised: July 11, 2002 / Accepted: August 14, 2002
RID="*"
ID="*" Present address: Center for Marine Environmental Studies, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577, Japan
(e-mail: nokuda@sci.ehime-u.ac.jp)
Acknowledgments I am grateful to S. Sone and D. Takahashi for giving us useful information and to M. Inoue and H. Miyatake for their field
assistance. This study was financially supported by Research Fellowships of the Japan Society for the Promotion of Science
for Young Scientists.
Correspondence to:Noboru Okuda 相似文献
874.
Sisson TH Hanson KE Subbotina N Patwardhan A Hattori N Simon RH 《American journal of physiology. Lung cellular and molecular physiology》2002,283(5):L1023-L1032
Plasminogen activator inhibitor-1 (PAI-1)-deficient transgenic mice have improved survival and less fibrosis after intratracheal bleomycin instillation. We hypothesize that PAI-1 deficiency limits scarring through unopposed plasminogen activation. If this is indeed true, then we would expect increased urokinase-type plasminogen activator (uPA) expression to result in a similar reduction in scarring and improvement in mortality. To test our hypothesis, using the tetracycline gene regulatory system, we have generated a transgenic mouse model with the features of inducible, lung-specific uPA production. After doxycycline administration, these transgenic animals expressed increased levels of uPA in their bronchoalveolar lavage (BAL) fluid that accelerated intrapulmonary fibrin clearance. Importantly, this increased plasminogen activator production led to a reduction in both lung collagen accumulation and mortality after bleomycin-induced injury. These results suggest that PAI-1 deficiency does protect against the effects of bleomycin-induced lung injury through unopposed plasmin generation. By allowing the manipulation of plasminogen activation at different phases of the fibrotic process, this model will serve as a powerful tool in further investigations into the pathogenesis of pulmonary fibrosis. 相似文献
875.
Arak Y Andoh A Fujiyama Y Hata K Makino J Shimada M Bamba H Okuno T Urushiyama N Bamba T 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2002,766(2):351-356
In a previous study, we reported a novel method for the separation and quantification of a strong negatively charged material, dextran sulfate sodium (DSS), using fluorometric labeling with 2-aminopyridine and size-exclusion high-performance liquid chromatography. In the present study, we developed a method for the separation of pyridylamino-DSS (PA-DSS) using reversed-phase high-performance liquid chromatography (RPLC). In vitro enzymatic degradation of the PA-DSS was carried out using alpha-amylase. In RPLC, depolymerized PA-DSS was eluted on the basis of molecular mass (in the order pentamer, trimer, dimer, and monomer of PA-DSS) and separations were more sharply than in size-exclusion chromatography. The combination of RPLC and size-exclusion chromatography also separated depolymerized PA-DSS as effectively as RPLC alone. 相似文献
876.
The intra-strand Parity Rule 2 of DNA (PR2) states that A=T and G=C within each strands. Useful corollaries of PR2 are G/(G+C)=A/(A+T)=0.5, G/(G+A)=C/(C+T)=G+C, G/(G+T)=C/(C+A)=G+C. Here. A, T, G, and C represent relative contents of the four nucleotide residues in a specific strand of DNA, so that A+T+G+C=1. Thus, deviations from the PR2 is a sign of strand-specific (or asymmetric) mutation and/or selection pressures. The present study delineates the symmetric and asymmetric effects of mutations on the intra-genomic heterogeneity of the G+C content in the human genome. The results of this study on the human genome are: (1) When both two- and four-codon amino acids were combined, only slight departures from the PR2 were observed in the total ranges of G+C content of the third-codon position. Thus, the G+C heterogeneity is likely to be caused by symmetric mutagenesis between the two strands. (2) The above result makes the deamination of cytosine due to double-strand breathing of DNA [Mol. Biol. Evol. 17 (2000) 1371] and/or incorporation of the oxidized guanine (8-oxo-guanine) opposite adenine during DNA replication (dGTP-oxidation hypothesis) as the most likely candidates for the major cause of the diversities of the G+C content. (3) Patterns of amino acid-specific PR2-biases detected by plotting PR2 corollaries against the G+C content of third codon position revealed that eight four-codon amino acids can be divided into three types by the second codon letter: (a) C2-type (Ala, Pro, Ser4, and Thr), (b) G2-type (Arg4 and Gly), and (c) T2-type (Leu4 and Val). (4) Most of the asymmetric plot patterns of the above three classes in PR2 biases can be explained by C2→T2 deamination of C2pG3 of C2-type to T2pG3 (T2-type) in both human and chicken. This explains the existence of some preferred codons in human and chicken. However, these biases (asymmetric) hardly contribute to the overall G+C content diversity of the third codon position. 相似文献
877.
Kano R Hattori Y Murakami N Mine N Kashima M Kroppenstedt RM Mizoguchi M Hasegawa A 《Microbiology and immunology》2002,46(6):409-412
The clinical isolates from biopsy specimen human subcutaneous nodule developed orange-colored and wrinkled colonies on Sabouraud's dextrose agar at 24 C for 2 weeks. The isolates were aerobic and gram-positive. The bacteria were rod-shaped to coccoid and 1 x 5 microm in size. The assimilation tests revealed that the clinical isolate was identical to a reference strain of Nocardia veterana. A nucleotide sequence analysis of the 16S ribosomal DNA from the isolate and a reference strain of N. veterana showed 99.8% similarity. All data are consistent with the conclusion that the isolate in this human case of mycetoma is N. veterana. 相似文献
878.
Mycoplasmal lipoproteins induce toll-like receptor 2- and caspases-mediated cell death in lymphocytes and monocytes 总被引:6,自引:0,他引:6
Into T Nodasaka Y Hasebe A Okuzawa T Nakamura J Ohata N Shibata K 《Microbiology and immunology》2002,46(4):265-276
Lipoproteins of Mycoplasma salivarium and Mycoplasma fermentans preferentially induced necrotic cell death in lymphocytic cell lines, MOLT-4 and Raji, and in one monocytic cell line, THP-1, whereas they preferentially induced apoptotic cell death in another monocytic cell line, HL-60. These findings were also supported by ultrastructural observations by the use of scanning and transmission electron microscopes and by agarose gel electrophoresis of the genomic DNA. The lipoproteins activated caspase-3 in both MOLT-4 and HL-60 cells, which was assessed by the cleavage of the synthetic substrate DEVD-pNA and the endogenous substrate poly(ADP-ribose) polymerase. The cytotoxicity to MOLT-4 and HL-60 cells was inhibited by various caspase inhibitors, Ac-DMQD-CHO, Ac-IETD-CHO, and Z-VAD-FMK. The cytotoxicity was also partially suppressed by the monoclonal antibody to Toll-like receptor 2. Thus this study demonstrated that mycoplasmal lipoproteins induce caspases-dependent necrotic and apoptotic cell death in lymphocytes and monocytes/macrophages, which is partially induced by TLR2-mediated signaling. 相似文献
879.
Two outer membrane proteins (Omps) of Vibrio cholerae O1, expressed in the intestine (in vivo) but not in culture media (in vitro), were investigated. The molecular masses of those proteins were 116 kDa and 15 kDa, and they were not associated with iron-regulated proteins. Convalescent cholera patients' sera reacted with the 15 kDa protein but not with the 116 kDa protein. The N-terminal amino acid sequence of the 15 kDa protein was homologous to V. cholerae OmpT. Anti-serum to the 15 kDa protein caused agglutination of the organisms grown in the intestine, but not the organisms in in vitro culture. The anti-serum was bactericidal, but it did not inhibit the adhesion of the organisms to the intestine and HEp-2 cells. These findings suggest the possibility that the 15 kDa protein could be involved in post-infection immunity. 相似文献
880.
Inoue N Watanabe T Kutsukake T Saitoh H Tsumura H Arai H Takeuchi M 《Glycoconjugate journal》1999,16(11):707-718
Human thrombopoietin (TPO) that regulates the numbers of megakaryocytes and platelets is a heavily N- and O-glycosylated glycoprotein hormone with partial homology to human erythropoietin (EPO). We prepared recombinant human TPO produced in Chinese hamster ovary (CHO) cells and analyzed the sugar chain structures quantitatively using 2-aminobenzamide labeling, sequential glycosidase digestion and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS).We found bi-, tri- and tetraantennary complex-type sugar chains with one or two N-acetyllactosamine repeats, which are common to recombinant human EPO produced in CHO cells. On the other hand, there were triantennary sugar chains with one or two N-acetyllactosamine repeats that were specific to the recombinant human TPO, and their distributions of branch structures were also different. These results suggested that proximal protein structure should determine the branch structure of Asn-linked sugar chains in addition to the glycosyltransferases subset. 相似文献