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91.
Johnson DW Trinh MU Oe T 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,798(1):159-162
High pressure liquid chromatography with a narrow bore C8 column has been used to separate pristanic, phytanic and very long chain fatty acids, important in the diagnosis of peroxisomal disorders, for their accurate isotope dilution quantification by tandem mass spectrometry. The fatty acids, isolated from plasma, were analysed as trimethylaminoethyl ester (quaternary ammonium) derivatives. Analysis time was 2.5 h and sample requirement was 10 microl of plasma. Good agreement with GC-MS methods for the levels of pristanic and phytanic acids, C26:0/C22:0 and C24:0/C22:0 ratios were obtained for 12 plasma samples from peroxisomal disorder patients and a set of controls. 相似文献
92.
Ohno T Kita M Yamaoka Y Imamura S Yamamoto T Mitsufuji S Kodama T Kashima K Imanishi J 《Helicobacter》2003,8(3):207-215
Background. Helicobacter pylori is an important pathogen responsible for gastroduodenal diseases in humans. Although the eradication of H. pylori using antibiotics often improves gastroduodenal diseases, resistance to the antibiotics is emerging. Materials and Methods. The antimicrobial effect of essential oils and the development of resistance to the essential oils were evaluated in vitro and in vivo. Results. Thirteen essential oils used in this study completely inhibited the growth of H. pylori in vitro at a concentration of 0.1% (v/v). Cymbopogon citratus (lemongrass) and Lippia citriodora (lemon verbena) were bactericidal against H. pylori at 0.01% at pH 4.0 and 5.0. Resistance to lemongrass did not develop even after 10 sequential passages, whereas resistance to clarithromycin developed under the same conditions. In in vivo studies, the density of H. pylori in the stomach of mice treated with lemongrass was significantly reduced compared with untreated mice. Conclusions. These results demonstrate that the essential oils are bactericidal against H. pylori without the development of acquired resistance, suggesting that essential oils may have potential as new and safe agents for inclusion in anti‐H. pylori regimens. 相似文献
93.
We have applied in vivo intracellular antibody capture (IAC) technology to isolate human intrabodies which bind to the oncogenic RAS protein. IAC facilitates the capture of antibody fragments, in this case single-chain Fvs (scFvs), which tolerate reducing environments, such as the cytoplasm of cancer cells. Three anti-RAS scFvs with different affinity, solubility and intracellular binding activity were characterized. The anti-RAS scFvs with highest affinity were expressed relatively poorly in mammalian cells, and greater soluble expression was achieved by mutating the antibody framework to canonical consensus scaffolds, previously derived from IAC, without losing antigen specificity. Mutagenesis experiments showed that the consensus scaffolds are functional as intrabody fragments without an intra-domain disulfide bond. Furthermore, we could convert an intrabody which does not bind RAS in mammalian cells into a high-affinity reagent capable of inhibiting RAS-mediated NIH 3T3 transformation by exchanging VH and VL complementarity-determining regions onto its consensus scaffold. These data show that the consensus scaffold is a robust framework by which to improve intrabody function. 相似文献
94.
WAVE2 deficiency reveals distinct roles in embryogenesis and Rac-mediated actin-based motility 总被引:11,自引:0,他引:11
Yan C Martinez-Quiles N Eden S Shibata T Takeshima F Shinkura R Fujiwara Y Bronson R Snapper SB Kirschner MW Geha R Rosen FS Alt FW 《The EMBO journal》2003,22(14):3602-3612
The Wiskott-Aldrich syndrome related protein WAVE2 is implicated in the regulation of actin-cytoskeletal reorganization downstream of the small Rho GTPase, Rac. We inactivated the WAVE2 gene by gene-targeted mutation to examine its role in murine development and in actin assembly. WAVE2-deficient embryos survived until approximately embryonic day 12.5 and displayed growth retardation and certain morphological defects, including malformations of the ventricles in the developing brain. WAVE2-deficient embryonic stem cells displayed normal proliferation, whereas WAVE2-deficient embryonic fibroblasts exhibited severe growth defects, as well as defective cell motility in response to PDGF, lamellipodium formation and Rac-mediated actin polymerization. These results imply a non-redundant role for WAVE2 in murine embryogenesis and a critical role for WAVE2 in actin-based processes downstream of Rac that are essential for cell movement. 相似文献
95.
We describe a new enzymatic reaction method for the preparation of the radioisotope-labeled cytokinins isopentenyladenine
(iP), trans-zeatin (tZ), and their ribosides. The method is based on the three enzyme activities of an adenylate isopentenyltransferase
(IPT; EC 2.5.1.27) from Arabidopsis thaliana, an alkaline phosphatase (EC 3.1.3.1) from calf intestine, and a purine-nucleoside phosphorylase (EC 2.4.2.1) from Escherichia coli. The A. thaliana IPT, AtIPT7, utilized both dimethylallyldiphosphate and 4-hydroxy-3-methyl-2-(E)-butenyl diphosphate as isoprenoid donors. The dual specificity of the substrates enabled us to produce iP-type and tZ-type
cytokinins separately in the same system simply by switching the substrates. Our method affords a much higher yield of the
labeled products than the chemical reaction methods previously used. These labeled compounds will be useful tools for cytokinin
research, such as receptor–ligand assays and cell metabolism studies. 相似文献
96.
Goro Yoshizaki Kiyoko Fujinuma Yoshiko Iwasaki Tomoyuki Okutsu Shinya Shikina Ryosuke Yazawa Yutaka Takeuchi 《Comparative biochemistry and physiology. Part D, Genomics & proteomics》2011,6(1):55-61
Recent progress in genome-based breeding has created various fish strains carrying desirable genetic traits; however, methods for the long-term preservation of their genetic resources have not yet been developed, mainly due to the lack of cryopreservation techniques for fish eggs and embryos. Recently, we established an alternative cryopreservation technique for fish spermatogonia using a slow-freezing method. Furthermore, we developed a transplantation system to produce functional eggs and sperm derived from spermatogonia. Spermatogonia isolated from the testes of vasa-green fluorescent protein (Gfp) transgenic rainbow trout (Oncorhynchus mykiss) were transplanted into the peritoneal cavity of triploid masu salmon (Oncorhynchus masou) hatchlings of both genders. The transplanted trout spermatogonia migrated towards the gonadal anlagen of the recipient salmon, into which they were subsequently incorporated. We confirmed that the donor-derived spermatogonia resumed gametogenesis, and produced sperm and eggs in male and female recipient salmon, respectively. Fertilization of the resultant eggs and sperm produced only rainbow trout in the first filial (F1) generation, suggesting that the sterile triploid recipient salmon produced functional eggs and sperm derived from the trout donors. A combination of spermatogonial transplantation and cryopreservation could be a powerful tool for preserving valuable fish strains with desirable genetic traits and endangered species. 相似文献
97.
Increase in Alkaline Phosphatase Activity in Cucumber Roots during Calcium Starvation 总被引:1,自引:0,他引:1
Alkaline phosphatase activity in cucumber roots increased withcalcium deficiency. However, acid phosphatase was scarcely affectedby the treatment. Re-addition of calcium not only suppressedthe continuous increase in alkaline phosphatase activity butalso reduced the already formed activity. Alkaline phosphatase activity increased with a deficiency ofcalcium, phosphate, minor elements and iron in this order. Eithercycloheximide or actinomycin D completely suppressed the increasein the activity caused by calcium deficiency. (Received April 16, 1981; Accepted July 17, 1981) 相似文献
98.
Tomo Inomata Hiroyoshi Ninomiya Tomoyuki Mizutani Yuko Mori Naomi Kashiwazaki Akio Kiuchi Tetsushi Nagai 《Experimental Animals》2005,54(2):117-122
A simple method of ileocolostomy was performed in rats. The colon near the cecum was ligated, including its arteries and veins. Main artery and vein of the cecum were ligated. Then, the cecum was cut out. A longitudinal incision was made on the anti-mesenteric side of the proximal end of the colon, approximately 7-8 mm long. A 21-G needle was inserted toward the incision 2 cm away from the proximal end of the anti-mesenteric side of the colon. A nylon suture was knotted once to the distal end of the ileum and was introduced into the tip of the needle which had previously been passed through the colon. Then, the needle was removed. The suture was pulled to introduce the distal end of the ileum into the colonic lumen. Then, the suture was knotted once on the colon again to fix the ileum to the colon. The incision in the proximal end of the colon was not closed. At the 2nd week after the operation, X-ray examinations demonstrated that the ileocolonic passages with no leakage at the anastomotic site were quite satisfactory. At the 4th week after the operation, there were no macroscopic or microscopic complications at the anastomotic site. The mucosal and serosal epithelia of the ileum and colon continued smoothly. This simple method may be very effective in preparing anastomosis in the gastrointestinal tract, especially in small laboratory animals for nutritional and surgical experiments. 相似文献
99.
Imidazole dipeptides can quench toxic 4‐oxo‐2(E)‐nonenal: Molecular mechanism and mass spectrometric characterization of the reaction products
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Imidazole dipeptides, such as carnosine (β‐alanyl‐l ‐histidine) and anserine (β‐alanyl‐Nπ‐methyl‐l ‐histidine), are highly localized in excitable tissues, including skeletal muscle and nervous tissue, and play important roles such as scavenging reactive oxygen species and quenching reactive aldehydes. We have demonstrated several reactions between imidazole dipeptides (namely, carnosine, and anserine) and a lipid peroxide‐derived reactive aldehyde 4‐oxo‐2(E)‐nonenal. Seven carnosine adducts and two anserine adducts were characterized using liquid chromatography/electrospray ionization‐multiple‐stage mass spectrometry. Adduct formation occurred between imidazole dipeptides and 4‐oxo‐2(E)‐nonenal mainly through Michael addition, Schiff base formation, and/or Paal‐Knorr reaction. The reactions were much more complicated than the reaction with a similar lipid peroxide‐derived reactive aldehyde, 4‐hydroxy‐2(E)‐nonenal. 相似文献
100.
Tomoyuki Makino Maya Yamashita Natsumi Takeuchi Toshihide Kabuki Makoto Hattori 《Bioscience, biotechnology, and biochemistry》2013,77(12):2298-2306
ABSTRACTLactic acid bacteria are known to have various health-promoting effects and are highly expected to find applications in anti-allergic food materials. In this study, we focused on Lactobacillus helveticus SBT2171 (LH2171), which reportedly modifies some unique immune responses and ameliorated symptoms of patients allergic to mites and house dust in the previous studies. We examined the effect of LH2171 on cytokine production by antigen-stimulated murine naïve splenocytes in vitro and demonstrated that it inhibited IL-4 and IL-13 production while enhancing IFN-γ and IL-10 production. Then, we examined the anti-allergic effect of LH2171 in vivo using a murine model of pollen allergy and found that LH2171 reduced the sneezing frequency when orally administered to mice. We successfully confirmed the immune modulatory activity of LH2171 and its anti-allergic activity against inhaled antigens. These evidences would contribute to identifying the anti-allergic mechanism of LH2171.Abbreviations: ALDH: aldehyde dehydrogenase; EGCG: epigallocatechin gallate; LAB: lactic acid bacteria; LH2171: Lactobacillus helveticus SBT2171; NALT: nasal-associated lymphoid tissue; OVA: ovalbumin 相似文献