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71.
Characteristics of macrolide-resistant Mycoplasma pneumoniae strains isolated from patients and induced with erythromycin in vitro 总被引:3,自引:0,他引:3
Okazaki N Narita M Yamada S Izumikawa K Umetsu M Kenri T Sasaki Y Arakawa Y Sasaki T 《Microbiology and immunology》2001,45(8):617-620
Some patients with Mycoplasma pneumoniae infection are clinically resistant to antibiotics such as erythromycin, clarithromycin, or clindamycin. We isolated M. pneumoniae from such patients and found that one of three isolates showed a point mutation in the 23S rRNA gene. Furthermore, 141 EM-sensitive clinical isolates of M. pneumoniae were cultured in broth medium containing 100 microg/ml of erythromycin (EM). Among 11 EM-resistant strains that grew in the medium, point mutations in the 23S rRNA were found in 3 strains at A2063G, 5 strains at A2064G and 3 strains at A2064C. The relationship between the point mutation pattern of these EM-resistant strains and their resistance phenotypes to several macrolide antibiotics was investigated. 相似文献
72.
Nishi M Yasue A Nishimatu S Nohno T Yamaoka T Itakura M Moriyama K Ohuchi H Noji S 《Biochemical and biophysical research communications》2002,293(1):247-251
Myostatin, which is a member of the TGF-beta superfamily, is a negative regulator of skeletal muscle formation. Double-muscled Piedmontese cattle have a C313Y mutation in myostatin and show increased skeletal muscle mass which resulted from an increase of myofiber number (hyperplasia) without that of myofiber size (hypertrophy). To examine whether this mutation in myostatin gene affects muscle development in a dominant negative manner, we generated transgenic mice overexpressing the mutated gene. The transgenic mice exhibited dramatic increases in the skeletal muscle mass resulting from hyperplasia without hypertrophy. In contrast, it has been reported that a myostatin mutated at its cleavage site produces hypertrophy without hyperplasia in the muscle. Thus, these results suggest that (1) the myostatin containing the missense mutation exhibits a dominant negative activity and that (2) there are two types in the dominant negative form of myostatin, causing either hypertrophy or hyperplasia. 相似文献
73.
Asano R Ikoma K Shimomura I Taki S Nakanishi T Umetsu M Kumagai I 《The Journal of biological chemistry》2011,286(3):1812-1818
Diabodies (Dbs) and tandem single-chain variable fragments (taFv) are the most widely used recombinant formats for constructing small bispecific antibodies. However, only a few studies have compared these formats, and none have discussed their binding kinetics and cross-linking ability. We previously reported the usefulness for cancer immunotherapy of a humanized bispecific Db (hEx3-Db) and its single-chain format (hEx3-scDb) that target epidermal growth factor receptor and CD3. Here, we converted hEx3-Db into a taFv format to investigate how format affects the function of a small bispecific antibody; our investigation included a cytotoxicity assay, surface plasmon resonance spectroscopy, thermodynamic analysis, and flow cytometry. The prepared taFv (hEx3-taFv) showed an enhanced cytotoxicity, which may be attributable to a structural superiority to the diabody format in cross-linking target cells but not to differences in the binding affinities of the formats. Comparable cross-linking ability for soluble antigens was observed among hEx3-Db, hEx3-scDb, and hEx3-taFv with surface plasmon resonance spectroscopy. Furthermore, drastic increases in cytotoxicity were found in the dimeric form of hEx3-taFv, especially when the two hEx3-taFv were covalently linked. Our results show that converting the format of small bispecific antibodies can improve their function. In particular, for small bispecific antibodies that target tumor and immune cells, a functional orientation that avoids steric hindrance in cross-linking two target cells may be important in enhancing the growth inhibition effect. 相似文献
74.
75.
Kenji Maekaji Mitsuo Sunagawa Hiroshi Imai 《Bioscience, biotechnology, and biochemistry》2013,77(3):165-169
Two kinds of anthocyanin were isolated from the petals of white peach and examined by paper chromatographic and spectral analyses. The results showed that one of them is crysanthemin and the other is a derivative of chrysanthemin which has not been isolated from peaches previously. 相似文献
76.
Kenji Kinoshita Satoshi Yaginuma Mitsuo Hayashi Kazumi Nakatsu 《Nucleosides, nucleotides & nucleic acids》2013,32(5):661-668
Abstract The molecular and crystal structure of neplanocin C(3), C11H13N5O4 M.W. = 279.26, has been determined by X-ray anlys?s. The space group is P21 with a=16.381(2), b=8.210(1), c=9.127(1) Å, β=105.31(1)° and z=4. The structure was solved by direct method, and least-squares refinement using 2093 reflections with |Fo|>3σ(F) led to the final R value of 0.0772. The sugar puckering of the two crystal-lographically independent molecules is C(2′)-exo-C(3′)-endo, and the torsion angles about the N(9)-C(1′) bond are 22.8(6) and 28.7(6)°, respectively (anti conformation). 相似文献
77.
Mitsuo. Sekine Hiroyuki. Tsuruoka Koh-ichiro. Shohda Tomohisa. Moriguchi Tomohisa. Wada 《Nucleosides, nucleotides & nucleic acids》2013,32(9-11):2033-2043
Abstract This paper describes general methods for the synthesis of N-phosphorylated ribonucleosides and oligonucleotides containing a 2′-O-phosphorylated or 2′-O-thiophosphorylated ribonucleoside. The NMR-based conformational analysis and computational molecular dynamics simulation of the 2′-O-phosphorylated ribonucleoside residue in such modified oligonucleotides suggested that the ribose residue existed preferentially in a C2′-endo conformation. It was also found that simple heating of 2′-O-phosphorylated oligonucleotides resulted in rapid dethiophosphorylation. 相似文献
78.
Keiichi Aritomo Chihiro Urashima Takeshi Wada Mitsuo Sekine 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):1-16
Abstract Reaction of 2′,3′,5′-O-silylated inosine derivative 1 with 2, 3-O-isopropylidene-5-O-tritylribosyl chloride (3) in a two-phase (CH2Cl2-aq. NaOH) system in the presence of Bu4NBr gave three products, i. e., 6-O-α-, 6-O-β-, and N 1-β-isomers of glycosides 4, 5a, and 5b. A similar PTC reaction of 1 with 2, 3, 5-tri-O-benzylribosyl bromide (9) gave four regio- and stereo-isomers involving the N1-β-glycoside 10. Reaction of 1 with 2, 3, 5-tri-O-benzoylribosyl bromide (11) afforded three products involving the desired N1-β-glycoside 12b, which could be deprotected to give N 1-ribosylinosine (15b) as a useful intermediate for the synthesis of cIDPR. 相似文献
79.
Masakatsu Kaneko Misako Kimura Yoshinobu Murofushi Takashi Yasumoto Yasuteru Iijima Mitsuo Yamazaki 《Nucleosides, nucleotides & nucleic acids》2013,32(2-4):865-887
Abstract Griseolic acid derivatives which were modified at the 2-and/or 6-positions were first synthesized from griseolic acid by a ring opening—reclosure reaction of the adenine ring. Among these derivatives, the 2-amino-6-deamino-6-hydroxyl (guanine) derivative showed 3.3 and 45 times stronger inhibitory activity against cAMP and cGMP PDE, respectively, than those of griseolic acid. Structure-activity relationships among these derivatives are also discussed. 相似文献
80.
Yuko Kimura Noboru Takamura Masato Fukunaga Mitsuo Kanagae Yasuyo Abe Kiyoshi Aoyagi 《Biomarkers》2013,18(3):291-297
Primary objective: To carry out a preliminary evaluation of subclinical inflammation and its genetic background in young adults.Research design: Fifty-five healthy Japanese young adults aged 19–27 years (37 males and 18 females, mean age: 22.3 years), and 58 healthy Japanese adults aged 40 to 60 years (21 males and 37 females, mean age: 51.5 years) were included in this study.Methods and procedures: We measured plasma high-sensitive C-reactive protein (hs-CRP) levels and screened for the C677T polymorphism of the 5-10 methylenetetrahydrofolate reductase gene (MTHFR), which is considered a genetic risk factor for atherosclerosis, by HinfI digestion.Main outcomes and results: Hs-CRP levels of the young adult group were significantly lower than the levels of the middle aged group (0.014±0.030 mg/dl vs. 0.031±0.040 mg/dl, p=0.005). The levels were significantly higher in males than in females (0.028±0.019 mg/dl vs. 0.013±0.010 mg/dl, p=0.008) among young adults. Furthermore, we evaluated the relationship of the C677T genotype and hs-CRP values, but found no association between them.Conclusions: Although the sample size is limited, our preliminary study demonstrated the profiles of hs-CRP in Japanese young adults. Further investigation will be needed to establish the guidelines for customized school health education using sensitive laboratory and genetic markers. 相似文献