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1.
Formation of a Tree having a Low Lignin Content 总被引:2,自引:0,他引:2
Received 30 September 2001/ Accepted in revised form 26 October 2001 相似文献
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Diabetic nephropathy (DN), a major cause of end-stage chronic renal failure, is histologically characterized by glomerulosclerosis. To investigate the molecular mechanisms of DN, it is important to establish a stable model of glomerulosclerosis in mice, because genomic manipulation techniques (such as gene destruction or transgene insertion) are well established in rodent species. In this study, we found that repeated administrations of streptozotocin led to early onset of glomerular sclerotic lesions in C57BL/6 mice, accompanied with renal dysfunction. During the natural course of DN, glomerular endothelial cells decreased at 10 weeks after the start of streptozotocin-injections, whereas myofibroblastic mesangial cells became evident. Our results provide an animal tool to elucidate the molecular mechanisms of DN, for example to investigate vascular pathology in diabetic glomerular diseases. 相似文献
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Tsuyoshi Akiyoshi Shinya Arinaga Hideo Tsuji 《Cancer immunology, immunotherapy : CII》1987,24(3):259-262
Summary The effects of mitomycin C (MMC) on the generation of cell-mediated cytotoxicity in primary stimulation culture of human peripheral blood mononuclear cells (PBM) with the B lymphoblastoid Raji cell line were assessed. The cell-mediated cytotoxicity induced in culture was significantly augmented when MMC was added to cultures on day –1 to day 3 for 24 h at concentrations of 2.5×10–2 g/ml and 2.5×10–3 g/ml. To identify the cell populations affected by MMC, PBM were separated by adherence to plastic after treatment with MMC for 24 h (day –1). The two populations were recombined with untreated separated cells and stimulated with antigen. The ability to develop an augmented cell-mediated cytotoxicity was associated with the adherent cell fraction of MMC-treated PBM. Therefore, the ability of MMC-treated adherent cells to produce interleukin 1 (IL 1) was examined. Significantly higher levels of IL 1 were produced by treated cells as compared to untreated adherent cells. The results appear to indicate that the selective effects of MMC on the adherent cell fraction, especially the modification of IL 1 production, may be involved in the mechanisms of MMC-induced augmented cell-mediated cytotoxicity. 相似文献
6.
Kenji Tomioka Kenji Yamada Shinya Yokoyama Yoshihiko Chiba 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(3):291-298
The coupling mechanism between the bilaterally paired optic lobe circadian pacemakers in the cricket Gryllus bimaculatus was investigated by recording locomotor activity, under constant light or constant red light, after the optic nerve was unilaterally severed.
These results suggest that the 2 optic lobe pacemakers weakly couple to one another and that the cricket maintains a stable temporal structure in its behavior through the phase-dependent mututal inhibition of activity and the phase-dependent freerunning period modulation. 相似文献
1. | The majority (about 70%) of the animals showed a locomotor rhythm with 2 rhythmic components; one freerunning with a period of 25.33 ± 0.41 (SD) h and the other with 24.36 ± 0.37 (SD) h under constant light (Fig. 3A). |
2. | Removal of the intact side optic lobe abolished the longer period component (Fig. 4A), while the operation on the operated side caused a reverse effect (Fig. 4B), indicating that the longer and the shorter period components are driven by the pacemaker on the intact and the operated side, respectively. |
3. | The activity driven by a pacemaker was inhibited during the subjective day of the contralateral pacemaker (circadian time 0–10, Fig. 5). |
4. | The freerunning periods of the two components were not constant but varied as a function of the mutual phase angle relationship (Figs. 3A, 7, 8). |
7.
Takeshi Murakami Hiroyuki Anzai Satoshi Imai Atsuyuki Satoh Kozo Nagaoka Charles J. Thompson 《Molecular & general genetics : MGG》1986,205(1):42-53
Summary We have isolated and studied the organization ofStreptomyces hygroscopicus genes responsible for the biosynthesis of the antibiotic herbicide bialaphos. Bialaphos production genes were cloned from
genomic DNA using a plasmid vector (pIJ702). Three plasmids were isolated which restored productivity toS. hygroscopicus mutants blocked at different steps of the biosynthetic pathway. Subcloning experiments using other nonproducing mutants showed
that four additional bialaphos production genes were also contained on these plasmids. A gene conferring resistance to bialaphos,
which was independently cloned using the plasmid vector pIJ61, and an antibiotic-sensitive host (S. lividans), was also linked to the production genes. Cosmids were isolated which defined the location of these genes in a 16 kb cluster. 相似文献
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Possible involvement of aminopeptidase, an ecto-enzyme, in the inactivation of bradykinin by intact neutrophils 总被引:1,自引:0,他引:1
The subcellular localization of the bradykinin-inactivating activity was studied using guinea-pig neutrophils and the following results were obtained. The bradykinin-inactivating activities were found to be present in the cytosol and membrane fractions but not in the granular and nuclear fractions. The bradykinin-inactivating activity of the cytosol fraction was inhibited by N-carbobenzoxy-Gly-Pro, an inhibitor of prolyl endopeptidase, whereas that of the membrane fraction was inhibited by bestatin, an inhibitor of aminopeptidase. Prolyl endopeptidase and aminopeptidase activities were located predominantly in the cytosol and membrane fractions, respectively, and their activities were inhibited by their respective inhibitors. Prolyl endopeptidase and aminopeptidase activities measured with synthetic substrates were competitively inhibited by bradykinin, suggesting that bradykinin is a possible substrate for prolyl endopeptidase and aminopeptidase. Intact neutrophils inactivated bradykinin rapidly. However, when neutrophils were modified chemically by diazotized sulfanilic acid, a poorly permeant reagent which inactivates ecto-enzymes selectively, both the bradykinin-inactivating activity and aminopeptidase activity of neutrophils decreased significantly without any inhibition of cytosol prolyl endopeptidase. The possibility that aminopeptidase, an ecto-enzyme, would be responsible for the inactivation of bradykinin by intact neutrophils was deduced from the results above, although both cytosol prolyl endopeptidase and membrane aminopeptidase could inactivate bradykinin. 相似文献
10.
M Sogami S Era S Nagaoka K Kuwata K Kida K Miura H Inouye E Suzuki S Hayano S Sawada 《International journal of peptide and protein research》1985,25(4):398-402
Human mercaptalbumin (HMA) and nonmercaptalbumin (HNA) could be separated by high-performance liquid chromatography (HPLC) at neutral pH. Using HPLC, the present authors found the nonmercapt-mercapt conversion (HNA----HMA) during hemodialysis and the mercapt-nonmercapt conversion (HMA----HNA) after hemodialysis in chronic renal failure, indicating HMA as the covalent carrier protein for sulfur-containing amino acids. 相似文献