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991.
Shiota S Shimizu M Sugiyama J Morita Y Mizushima T Tsuchiya T 《Microbiology and immunology》2004,48(1):67-73
Corilagin and tellimagrandin I are polyphenols isolated from the extract of Arctostaphylos uvaursi and Rosa canina L. (rose red), respectively. We have reported that corilagin and tellimagrandin I remarkably reduced the minimum inhibitory concentration (MIC) of beta-lactams in methicillin-resistant Staphylococcus aureus(MRSA). In this study, we investigated the effect of corilagin and tellimagrandin I on the penicillin binding protein 2 '(2a) (PBP2 '(PBP2a)) which mainly confers the resistance to beta-lactam antibiotics in MRSA. These compounds when added to the culture medium were found to decrease production of the PBP2 '(PBP2a) slightly. Using BOCILLIN FL, a fluorescent-labeled benzyl penicillin, we found that PBP2 '(PBP2a) in MRSA cells that were grown in medium containing corilagin or tellimagrandin I almost completely lost the ability to bind BOCILLIN FL. The binding activity of PBP2 and PBP3 were also reduced to some extent by these compounds. These results indicate that inactivation of PBPs, especially of PBP2 '(PBP2a), by corilagin or tellimagrandin I is the major reason for the remarkable reduction in the resistance level of beta-lactams in MRSA. Corilagin or tellimagrandin I suppressed the activity of beta-lactamase to some extent. 相似文献
992.
We investigated the effect of exercise on iron metabolism in horses. Four horses were walked on a mechanical walker for 1
wk (pre-exercise). They then performed moderate exercise on a high-speed treadmill in the first week of the exercise and relative
high in the second week and high in the third week. Serum iron was significantly lower in the third week of exercise than
in the pre-exercise. Transferrin saturation (TS) was significantly lower in the first and third weeks of exercise than in
the pre-exercise. Serum haptoglobin was significantly lower in the first week of exercise than in the pre-exercise and further
significantly lower in the second and third weeks than in the first. The packed cell volume did not change during the experiment.
The exercise significantly increased the apparent absorption of iron. Urinary iron excretion did not change throughout the
experiment. Sweat iron loss did not change during the exercise. The exercise significantly increased iron balance. We considered
that hemolysis is induced by moderate exercise and is further enhanced by heavy exercise, which decreases serum iron and TS.
However, the increase in iron absorption compensates for the adverse effect of exercise on iron status. Therefore, exercise
does not induce anemia in horses. 相似文献
993.
994.
Recent evidence suggests that cell cycle-related molecules play pivotal roles in multiple forms of cell death in post-mitotic neurons. Nevertheless, it remains unclear what molecular mechanisms are involved in the regulation of expression levels and activities of these molecules. We showed previously that treatment with extracellular glutamate decreases cyclin-dependent kinase inhibitor p27 before neuronal cell death. In this study, we demonstrate that reductions of both p27 and neuronal viability were dependent on activity of calpain, a Ca(2+)-dependent protease, but not on activity of caspase 3. Interestingly, the glutamate-induced reduction of p27 was not dependent on the ubiquitin-proteasome system. In fact, p27 was present only in the neuronal nucleus, whereas calpain 1, a ubiquitous calpain, was observed both in the neuronal nucleus and cytoplasm in control cultures. Glutamate treatment did not change the localization patterns of p27 and calpain 1. It reduced p27 expression level in the nucleus in a calpain-dependent manner. In vitro experiments using neuronal cell lysate and p27 recombinant protein revealed that p27 was degraded as a substrate of activated calpain 1. These results suggest that calpain(s), activated by glutamate treatment, degrade(s) p27 in the nucleus of neurons, which might promote aberrant cell cycle progression. 相似文献
995.
996.
Matsui T Hayashi-Kisumi F Kinoshita Y Katahira S Morita K Miyachi Y Ono Y Imai T Tanigawa Y Komiya T Tsukita S 《Genomics》2004,84(2):384-397
997.
Michio Masuko Kensuke Miyamoto Kensuke Sakurai Moritoshi Iino Yasuyoshi Takeuchi Tohru Hashimoto 《Phytochemistry》1983,22(5):1278-1280
Two new growth inhibitors, R-dihydromaleimide and R-dihydromaleimide β-d-glucoside, were isolated from 2-week-old pea shoots. 相似文献
998.
Kikuyoshi Yoshida Noboru Matsuura Nobuaki Tamahashi Tohru Takahashi 《Cell and tissue research》1993,272(1):1-10
Recently, we produced monoclonal antibodies reacting specifically with the reticular meshwork (RM) of lymphoid tissues, and demonstrated that, in the splenic white pulp of normal mouse, the antigenic heterogeneity of RM was associated with the segregation of the T and B lymphocytes. In the present study, we attempted to visualize further the interaction between splenic RM and T and B lymphocytes transferred into severe combined immunodeficient (SCID) mice. The splenic white pulp of naive SCID mice, containing a few T and B cells, showed little tendency for T-B segregation and antigenic diversity of RM. Transfer of spleen or bone marrow cells from normal mice resulted in complete recovery of lymphocyte populations, showing not only a clear segregation of T and B lymphocytes but also a remarkable antigenic diversity of RM. The same results were obtained following the transfer of spleen or bone marrow cells from the nude mouse. Next, we transferred purified T lymphocytes to one group of SCID mice and B cells to another. In mice given T cells, a few B cells were observed in the white puop; T lymphocytes lodged not only in the inner periarterial lymphatic sheath (PALS) but also in the outer PALS and follicles. In the animals to which B cells were transferred, T cells were few and the homing of B cells occurred only into their proper compartments, such as the outer PALS, follicles and marginal zone, but not in the inner PALS. Thus, B cells can home into their proper compartments of the splenic white pulp independently of T lymphocytes. 相似文献
999.
Recombination-Deficient Mutants of an Extreme Thermophile, Thermus thermophilus 总被引:6,自引:1,他引:5 下载免费PDF全文
Tohru Takada Satoshi Akanuma Takashi Kotsuka Masatada Tamakoshi Akihiko Yamagishi Tairo Oshima 《Applied microbiology》1993,59(8):2737-2739
Recombination-deficient strains of the extreme thermophile Thermus thermophilus have been prepared from a leucine-isoleucine mutant strain (NM6). The availability of such recombination-deficient thermophilic bacterial strains may provide especially good hosts for work with plasmid vectors. 相似文献
1000.
Misao Hiroto Motoyuki Yamada Tomoo Ueno Tohru Yasukohchi Ayako Matsushima Yoh Kodera Yuji Inada 《Biotechnology Techniques》1995,9(2):105-110
Summary Trypsin from bovine pancreas was coupled with copolymers of poly(ethylene glycol) derivative and maleic anhydride with the molecular weights of 13 kDa and 100 kDa (activated PM13 and PM100). The modified trypsins were more stable towards autolysis and heat- or urea-treatment than nonmodified trypsin. Stabilization of trypsin caused by the chemical modification with activated PMs is discussed in relation to the protein conformation. 相似文献