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排序方式: 共有1298条查询结果,搜索用时 62 毫秒
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Kei Watanabe Kenta Wada Tomoko Ohashi Saki Okubo Kensuke Takekuma Ryoichi Hashizume Jun-Ichi Hayashi Tadao Serikawa Takashi Kuramoto Yoshiaki Kikkawa 《PloS one》2012,7(11)
We discovered a new cataract mutation, kfrs4, in the Kyoto Fancy Rat Stock (KFRS) background. Within 1 month of birth, all kfrs4/kfrs4 homozygotes developed cataracts, with severe opacity in the nuclei of the lens. In contrast, no opacity was observed in the kfrs4/+ heterozygotes. We continued to observe these rats until they reached 1 year of age and found that cataractogenesis did not occur in kfrs4/+ rats. To define the histological defects in the lenses of kfrs4 rats, sections of the eyes of these rats were prepared. Although the lenses of kfrs4/kfrs4 homozygotes showed severely disorganised fibres and vacuolation, the lenses of kfrs4/+ heterozygotes appeared normal and similar to those of wild-type rats. We used positional cloning to identify the kfrs4 mutation. The mutation was mapped to an approximately 9.7-Mb region on chromosome 7, which contains the Mip gene. This gene is responsible for a dominant form of cataract in humans and mice. Sequence analysis of the mutant-derived Mip gene identified a 5-bp insertion. This insertion is predicted to inactivate the MIP protein, as it produces a frameshift that results in the synthesis of 6 novel amino acid residues and a truncated protein that lacks 136 amino acids in the C-terminal region, and no MIP immunoreactivity was observed in the lens fibre cells of kfrs4/kfrs4 homozygous rats using an antibody that recognises the C- and N-terminus of MIP. In addition, the kfrs4/+ heterozygotes showed reduced expression of Mip mRNA and MIP protein and the kfrs4/kfrs4 homozygotes showed no expression in the lens. These results indicate that the kfrs4 mutation conveys a loss-of-function, which leads to functional inactivation though the degradation of Mip mRNA by an mRNA decay mechanism. Therefore, the kfrs4 rat represents the first characterised rat model with a recessive mutation in the Mip gene. 相似文献
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The production of hydroxyl radicals during calcium paradox injury was investigated by measuring the production of 2,5-dihydroxybenzoic acid (2,5-DHBA) from salicylate. Four groups of rats were analyzed. In the first group, isolated hearts were perfused with calcium-free medium for 10 minutes followed by perfusion with medium containing Ca++ for 10 minutes. In the other groups, 0.25 microM N,N'-diphenyl-1,3-phenylenediamine (DPPD), 80 microM cytochrome c, or 450 U/ml catalase was added. Coronary effluent was analyzed for the presence of 2,5-DHBA, and tissue sections were examined using light microscopy. In the first group, 2,5-DHBA production began during the calcium-free period, peaked tenfold 60-90 sec. into the Ca repletion period, and declined thereafter. The increase in 2,5-DHBA was accompanied by severe cell damage. Cytochrome c reduced 2,5-DHBA production, and catalase almost completely inhibited 2,5-DHBA production, while DPPD had no effect on 2,5-DHBA production. None of the three additives provided any complete morphological protection. The data provide evidence for the production of hydroxyl radicals during calcium-paradox injury, that their production is dependent upon the presence of hydrogen peroxide, and that cell damage in the calcium paradox is not primarily mediated by the extracellular hydroxyl radicals. 相似文献
5.
Summary Conventional chemical fixation and paraffin-embedding procedures give good preservation of morphology, although the antigenicity of many proteins in the tissue sample is destroyed. On the other hand, fresh frozen sections can preserve the antigenicity, but provide poor morphological preservation. To overcome this dilemma, cryofixation and freeze drying were used on human skin tissue, applying methodology which has only been used to study lymphoid tissue. First, fresh human skin was cryofixed in liquid isopentane (–160° C) cooled by liquid nitrogen. The skin was then freeze-dried at –40° C and 10–2 atmospheric pressure for 72 h, followed by embedding in paraffin. Sections 4 m thick taken from this cryofixed, freeze-dried, and paraffin-embedded skin were stained with hematoxylin-eosin or used for immunolabeling with antibodies against basement membrane antigen, including type IV and type VII collagen, bullous pemphigoid antigen, epidermolysis bullosa acquisita antigen, and GB3 antigen. The morphological preservation of these sections was as good as that of routine formalin-fixed and paraffin-embedded skin sections. The basement membrane was clearly immunostained with all antibodies used, and the intensity of the reaction was as strong as that seen in frozen sections. Evaluation of antigen distribution in conjunction with the detailed skin structure was therefore possible in the same sections.A part of this work was presented at the 90th Annual Meeting of the Japanese Dermatological Association, Kyoto, Japan, April, 1991 相似文献
6.
Takashi Saito Kensuke Futatsugi Daisuke Miki Hiroshi Suzuki Kiyoshi Yasukawa 《Biotechnology Techniques》1992,6(4):365-370
Summary Murine interleukin-6 (mIL-6) was expressed inEscherichia coli as human growth hormone (hGH) fusion protein. The products were cleaved by thrombin to liberate mIL-6. Monoclonal and polyclonal
antibodies specific to mIL-6 were prepared by immunizing rats with mIL-6 thus obtained. ELISA for the quantitation of mIL-6
was also established, which could detect mIL-6 in a quantity as low as 2 ng/ml. 相似文献
7.
The mode of inheritance of hydronephrosis was investigated by crossing inbred DDD mice having a high incidence of hydronephrosis and C57BL/6 mice having normal kidneys. In the males, incidences of hydronephrosis in F1 animals were intermediate between the two parental strains at a rate of 32.6% in (DDD x C57BL/6)F1 and 23.4% in reciprocal F1. The same tendency was observed in F2 male animals. In BCF1 males, the number of affected mice was higher in (C57BL/6 x DDD) F1 x DDD (72.4%) than in (DDD x C57BL/6)F1 x C57BL/6 (11.1%). A few affected mice were found among the females of hybrids F1, F2 and BCF1. These results suggested that hydronephrosis in the DDD strain of mice was controlled by polygenes, and that male hormones may have some effect on the occurrence of hydronephrosis. 相似文献
8.
The properties of three fractions (FI, FII, and FIII) of porcine creatine kinase MM, which have been isolated by isoelectric focusing, were compared. Sugars were not detected in them. Their carboxyl-terminal sequences were identical and were determined to be -Thr-Lys by digestion with carboxypeptidases A and B. Immunodiffusion and competitive radioimmunoassay could not differentiate the three fractions from one another. Their amino-terminal sequences revealed that they had different primary structures. At residue 1, although all the three fractions had Pro, FI and FIII had an additional amino acid, Ser. At residue 23, only FI had Leu in addition to Ser, the amino acid common to the three fractions. These results indicate that differences among the three fractions of porcine creatine kinase MM are based on differences in the primary structures of the subunits in their dimer structures, and confirm the conclusion that FII is a homodimer and FI and FIII are heterodimers, which was reported in the preceding paper [Takasawa, T. & Shiokawa, H. (1983) J. Biochem. 93, 383-388]. 相似文献
9.
Endotoxic properties of chemically synthesized lipid A analogs. Studies on six inflammatory reactions in vivo, and one reaction in vitro 总被引:1,自引:0,他引:1
M Yoshida M Hirata K Inada N Tsunoda T Kirikae T Onodera Y Ishikawa O Sasaki T Shiba S Kusumoto 《Microbiology and immunology》1989,33(10):797-810
Biological activities of two groups of synthesized lipid A analogs, the counterpart of biosynthetic precursor, Lehmann's Ia type, 406, and E. coli lipid A type, 506, as well as their non-phosphorylated, and mono-phosphorylated analogs were investigated. The activities employed included four bone marrow cell reactions in mice, mice skin reaction, leukocytes migration in rabbits' cornea, and hemagglutination. Compound 406 and 506 elicited bone marrow reactions in mice and hemagglutination of mouse RBC, although 406 failed to elicit hemorrhage and necrosis also in mice skin. Compound 406 did not elicit corneal reaction in rabbits. The results suggest that for elicitation of this reaction and mice skin reaction, acyloxyacyl structure is required. Cytotoxicity and thromboplastin production of four bone marrow reactions had been reported by us to be endotoxic reactions, since these had not been elicited by peptidoglycan of Lactobacillus and Staphylococcus (1981) and 300 series synthesized analogs (1984) which did not have endotoxic structures. From these results, it seems that these two marrow reactions and hemagglutination require, as does the limulus test, the lipid A part structure as is present in 406. 相似文献
10.
Yuichiro Arai Se KyungKim Hiroyasu Kinemuchi Takeshi Tadano Shinetsu Satoh Nobunori Satoh Katsuyuki Oyama Kensuke Kisara 《Neurochemistry international》1990,17(4):587-592
The present study was carried out mainly to clarify whether the two amphetamine metabolites, p-hydroxyamphetamine (P-OHA) and p-hydroxynorephedrine (p-OHN) are taken up by mouse brain 5-hydroxytryptamine (5-HT) nerve terminals to inhibit type A monoamine oxidase (MAO-A) and then potentiate the abnormal behavior, head-twitch. Of the two metabolites, only intracerebroventricular p-OHA, at 80 μg/mouse, sufficient to cause a head-twitch response (HTR), appreciably inhibited MAO-A activity without affecting MAO-B activity in homogenates of the mouse striatum, hypothalamus and the rest of the forebrain; and p-OHN did not inhibit either type of MAO at the dose tested. Estimation of intra- and extrasynaptosomal MAO-A activity showed that both metabolites significantly inhibited only the intrasynaptosomal deamination of 5-HT by MAO-A with p-OHA being more potent. Taken together with our previous findings, these present results clearly indicate that p-OHA may accumulate in the 5-HT nerve terminals through the uptake system, and concomitantly inhibit MAO-A activity. These actions of p-OHA may increase intraneuronal 5-HT levels and then potentiate 5-HT release to cause interaction with the post-synaptic 5-HT receptors. 相似文献