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991.
H Nakashima Y Hirata M Uchihashi T Fujita H Taniguchi S Baba S Matsukura 《Hormones et métabolisme》1985,17(4):205-208
Release of plasma ACTH- and beta-endorphin (beta-EP)-like immunoreactivity (LI) was studied in vivo in a patient with an ectopic ACTH-producing malignant thymoma. Administration of lysin vasopressin stimulated concomitant release of plasma ACTH- and beta-EP-LI. Administration of cyproheptadine, naloxone, and somatostatin significantly suppressed plasma levels of ACTH- and beta-EP-LI, while saline infusion did not. Gel exclusion chromatography of the plasma extracts revealed that ACTH-LI consisted of two components, large and small molecular weight form, while beta-EP-LI consisted of three components, large molecular weight, beta-lipotropin-, and beta-EP-sized form; each of these components was incompletely suppressed by somatostatin infusion. It is suggested that certain tumors may have acquired aberrant multiple receptors during malignant transformation which may lead to the paradoxical hormone response as demonstrated in this case. 相似文献
992.
Wenming Wang Milos Tanurdzic Meizhong Luo Nicholas Sisneros Hye Ran Kim Jing-Ke Weng Dave Kudrna Christopher Mueller K Arumuganathan John Carlson Clint Chapple Claude de Pamphilis Dina Mandoli Jeff Tomkins Rod A Wing Jo Ann Banks 《BMC plant biology》2005,5(1):1-8
Background
The lycophytes are an ancient lineage of vascular plants that diverged from the seed plant lineage about 400 Myr ago. Although the lycophytes occupy an important phylogenetic position for understanding the evolution of plants and their genomes, no genomic resources exist for this group of plants.Results
Here we describe the construction of a large-insert bacterial artificial chromosome (BAC) library from the lycophyte Selaginella moellendorffii. Based on cell flow cytometry, this species has the smallest genome size among the different lycophytes tested, including Huperzia lucidula, Diphaiastrum digita, Isoetes engelmanii and S. kraussiana. The arrayed BAC library consists of 9126 clones; the average insert size is estimated to be 122 kb. Inserts of chloroplast origin account for 2.3% of the clones. The BAC library contains an estimated ten genome-equivalents based on DNA hybridizations using five single-copy and two duplicated S. moellendorffii genes as probes.Conclusion
The S. moellenforffii BAC library, the first to be constructed from a lycophyte, will be useful to the scientific community as a resource for comparative plant genomics and evolution. 相似文献993.
994.
Fujita M Shiota S Kuroda T Hatano T Yoshida T Mizushima T Tsuchiya T 《Microbiology and immunology》2005,49(4):391-396
During the screening of compounds that potentiate the effect of antimicrobial agents against methicillin-resistant Staphylococcus aureus(MRSA), we found that an extract of thyme (Thymus vulgaris L) leaves greatly reduced the minimum inhibitory concentration (MIC) of tetracycline against MRSA. We isolated the effective compound and identified it as baicalein (5, 6, 7-trihydroxyflavone). One of the clinically isolated MRSA strains possessed tetK, a gene encoding active efflux pump for tetracycline. We examined the effect of baicalein on the efflux of tetracycline, using Escherichia coli KAM32/pTZ1252 carrying the tetK. The E. coli KAM32/pTZ1252 showed 8 to 16 times higher MIC than E. coli KAM32. We observed strong inhibition of transport of tetracycline by baicalein with membrane vesicles prepared from E. coli KAM32/pTZ1252. Baicalein also showed synergy with tetracycline in a MRSA strain that doesn't possess tetK, or with beta-lactams. Thus, mechanisms of the synergies seem to be versatile. 相似文献
995.
Göran Ekborg Martin Klinger Lennart Rodén John Wjesen John S Schutzbach Dee H Huang N Rama Krishna Gattadalli M Anantharamaiah 《Glycoconjugate journal》1987,4(3):255-266
3-O-β-d-Xylopyranosyl-l-serine (xylosylserine) was synthesized by the following three-step procedure: 1) 2,3,4-tri-O-benzoyl-α-d-xylopyranosyl bromide (benzobromoxylose) was condensed withN-carbobenzoxy-l-serine benzyl ester using the silver triflate-collidine complex as promoter; 2) theN-carbobenzoxy and benzyl ester groups in the resultant glycoside were cleaved by transfer hydrogenation with palladium black as catalyst and ammonium formate as hydrogen donor; and 3) the benzoyl groups were removed with methanolic ammonia. Xylosylserine was obtained in an overall yield of 70%. O-β-d-Galactopyranosyl-(1-4)-O-β-d-xylopyranosyl-(1-3)-l-serine (galactosylxylosylserine) was also synthesized by this methodology and was characterized by 2-dimensional (2D) NMR spectroscopy techniques. The two serine glycosides (xylosylserine and galactosylxylosylserine) were used in detection and partial purification of galactosyltransferase I (UDP-d-galactose:d-xylose galactosyltransferase) from adult rat liver. 相似文献
996.
Uenishi Y Fujita Y Kusunose N Yano I Sunagawa M 《Journal of microbiological methods》2008,72(2):149-156
The mycobacterial cell envelope consists of a characteristic cell wall skeleton (CWS), a mycoloyl arabinogalactan peptidoglycan complex, and related hydrophobic components that contribute to the cell surface properties. Since mycolic acids have recently been reported to play crucial roles in host immune response, detailed molecular characterization of mycolic acid subclasses and sub-subclasses of CWS from Mycobacterium bovis BCG Tokyo 172 (SMP-105) was performed. Mycolic acids were liberated by alkali hydrolysis from SMP-105, and their methyl esters were separated by silica gel TLC into three subclasses: alpha-, methoxy-, and keto-mycolates. Each mycolate subclass was further separated by silver nitrate (AgNO(3))-coated silica gel TLC into sub-subclasses. Molecular weights of individual mycolic acid were determined by MALDI-TOF mass spectrometry. alpha-Mycolates were sub-grouped into cis, cis-dicyclopropanoic (alpha1), and cis-monocyclopropanoic-cis-monoenoic (alpha2) series; methoxy-mycolates were sub-grouped into cis-monocyclopropanoic (m1), trans-monocyclopropanoic (m2), trans-monoenoic (m3), cis-monocyclopropanoic-trans-monoenoic (m4), cis-monoenoic (m5), and cis-monocyclopropanoic-cis-monoenoic (m6) series; and keto-mycolates were sub-grouped into cis-monocyclopropanoic (k1), trans-monocyclopropanoic (k2), trans-monoenoic (k3), cis-monoenoic (k4), and cis-monocyclopropanoic-cis-monoenoic (k5) series. The position of each functional group, including cyclopropane rings and methoxy and keto groups, was determined by analysis of the meromycolates with fast atom bombardment (FAB) mass spectrometry and FAB mass-mass spectrometry, and the cis/trans ratio of cyclopropane rings and double bonds were determined by NMR analysis of methyl mycolates. Mycolic acid subclass and molecular species composition of SMP-105 showed characteristic features including newly-identified cis-monocyclopropanoic-trans-monoenoic mycolic acid (m4). 相似文献
997.
Marie Louis Amélia Viricel Tamara Lucas Hélène Peltier Eric Alfonsi Simon Berrow Andrew Brownlow Pablo Covelo Willy Dabin Rob Deaville Renaud de Stephanis François Gally Pauline Gauffier Rod Penrose Monica A. Silva Christophe Guinet Benoit Simon‐Bouhet 《Molecular ecology》2014,23(4):857-874
Despite no obvious barrier to gene flow, historical environmental processes and ecological specializations can lead to genetic differentiation in highly mobile animals. Ecotypes emerged in several large mammal species as a result of niche specializations and/or social organization. In the North‐West Atlantic, two distinct bottlenose dolphin (Tursiops truncatus) ecotypes (i.e. ‘coastal’ and ‘pelagic’) have been identified. Here, we investigated the genetic population structure of North‐East Atlantic (NEA) bottlenose dolphins on a large scale through the analysis of 381 biopsy‐sampled or stranded animals using 25 microsatellites and a 682‐bp portion of the mitochondrial control region. We shed light on the likely origin of stranded animals using a carcass drift prediction model. We showed, for the first time, that coastal and pelagic bottlenose dolphins were highly differentiated in the NEA. Finer‐scale population structure was found within the two groups. We suggest that distinct founding events followed by parallel adaptation may have occurred independently from a large Atlantic pelagic population in the two sides of the basin. Divergence could be maintained by philopatry possibly as a result of foraging specializations and social organization. As coastal environments are under increasing anthropogenic pressures, small and isolated populations might be at risk and require appropriate conservation policies to preserve their habitats. While genetics can be a powerful first step to delineate ecotypes in protected and difficult to access taxa, ecotype distinction should be further documented through diet studies and the examination of cranial skull features associated with feeding. 相似文献
998.
999.
Inoue M Suzuki T Fujita Y Oda M Matsumoto N Yamase T 《Journal of inorganic biochemistry》2006,100(7):1225-1233
The enhancement of antibacterial activity of beta-lactam antibiotics by polyoxometalates against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) was investigated by using K6[P2W18O62] . 14H2O (P2W18), K4[SiMo12O40] . 3H2O (SiMo12), and K7[PTi2W10O40] . 6H2O (PTi2W10). Susceptibility test by a beta-lactam-disk method showed the synergistic effect of the polyoxometalates in combination with oxacillin against both MRSA and VRSA. Energy dispersive X-ray analysis of the strain treated with P2W18 revealed localization of the polyoxometalate-tungsten atoms at the periphery of the cell, and the biological reduction of P2W18 and SiMo12 proceeded within both cells of MRSA and VRSA as far as they keep alive. These results indicate that the polyoxometalates can penetrate through the cell wall consisting of peptidoglycan layers and reach cytoplasmic membrane. The inhibitory effect of the polyoxometalates on both mecA- and pbp-induced mRNA expression of both MRSA and VRSA cells, verified by the RT-PCR-electrophoresis analysis, is observed, and the mechanism of the synergistic effect by the polyoxometalates is discussed in terms of the depression of penicillin-binding protein 2' (PBP2') coded by mecA gene. 相似文献
1000.
Toshitsugu Kawata Chiyoko Tokimasa Tadashi Fujita Masato Kaku Keisuke Tsutsui Shinya Kohno Akira Matsuki Kaoru Tenjo Junji Ohtani Masahide Motokawa Takashi Kobayakawa Mao Shigekawa Kazuo Tanne 《Experimental Animals》2002,51(5):521-524
The time-dependent effects of daily dosing of IGF-I (1.21 mg/g) on the linear growth of the femur were investigated in mice. The femoral length and volume and the number of osteoclasts were significantly greater after IGF-I injection as compared to the non-injected control, suggesting that the IGF-I imbalance might cause a quick turnover cycle of the bone resulting in the altered femoral modeling. 相似文献