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61.
探讨p38蛋白激酶信号传导通路在细胞中的特异性作用机制。应用共聚焦激光扫描技术观察心肌细胞中p38蛋白激酶的分布及LPS对其分布的影响。结果提示未受刺激静止的及EGF刺激的心肌细胞中,p38在胞浆和胞核中荧光强度呈散性分布。LPS刺激30分钟后,细胞核区的荧光强度明显增强,而胞浆区域的荧光强度降低,心肌细胞受LPS刺激激活后,其p38蛋白激酶由胞浆转位到胞核。 相似文献
62.
A mouse model for the "sudden death" and "malarial lung" syndromes is described. Mice of the C3H/z strain succumb suddenly approximately 7 days after an infection with Plasmodium berghei becomes patent, at a time when parasitemia is still moderate (6 to 8%). Death could be shown to be due to anaphylactoid shock, probably induced by soluble immune complexes. Increased vascular permeability caused transudation and leakage of serum proteins into the interstitium and the alveoli. The lungs were found to be edematous, with a fine granular precipitate in the alveoli and adherent to the vascular walls. The precipitates reacted with antiglobulins G and M, and could be shown to also contain malaria antigens and C3/4. A dramatic drop in hematocrit was recorded several hours before death, indicating the sudden release of malaria antigens. The myocardium of animals that had died very suddenly showed a patchy loss of phosphorylase activity. This loss of activity was much more extensive, and sometimes almost total, when there had been an agonal period of several (1 to 3) hours before death. In these cases the irreversibility of the myocardial damage was also indicated by the loss of activity of the dehydrogenases, as well as by typical inflammatory reactions of granulocytic and histiocytic infiltrations. The hearts thus presented a typical picture of the acute and peracute shock syndromes. In acute shock cardiac insufficiency develops so suddenly that death ensues before irreversible damage has occurred, and cardiac insufficiency can only be demonstrated by the most sensitive of enzyme histochemical means. In the present case shock was induced by the anaphylactoid activity of immune complexes with the lung as target organ. The described syndrome appears analogous to human "malarial lung." 相似文献
63.
The ethoxy chains of short ethoxy chain nonylphenol (NPEOav2.0, containing average 2.0 ethoxy units) were dehydrogenated by cell-free extracts from Ensifer sp. strain AS08 grown on a basal medium supplemented with NPEOav2.0. The reaction was coupled with the reduction in 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide and phenazine
methosulfate. The enzyme (NPEOav2.0 dehydrogenase; NPEO-DH) was purified to homogeneity with a yield of 20% and a 56-fold increase in specific activity. The
molecular mass of the native enzyme was 120 kDa, consisting of two identical monomer units (60 kDa). The gene encoding NPEO-DH
was cloned, which consisted of 1,659 bp, corresponding to a protein of 553 amino acid residues. The deduced amino acid sequence
agreed with the N-terminal amino acid sequence of the purified NPEO-DH. The presence of a flavin adenine dinucleotide (FAD)-binding
motif and glucose–methanol–choline (GMC) oxidoreductase signature motifs strongly suggested that the enzyme belongs to the
GMC oxidoreductase family. The protein exhibited homology (40–45% identity) with several polyethylene glycol dehydrogenases
(PEG-DHs) of this family, but the identity was lower than those (approximately 58%) among known PEG-DHs. The substrate-binding
domain was more hydrophobic compared with those of glucose oxidase and PEG-DHs. The recombinant protein had the same molecular
mass as the purified NPEO-DH and dehydrogenated PEG400-2000, NPEOav2.0 and its components, and NPEOav10, but only slight or no activity was found using diethylene glycol, triethylene glycol, and
PEG200.
English edition: The paper was edited by a native speaker through American Journal Experts (). 相似文献
64.
65.
Telma M. T. Zorn Estela M. A. F. Bevilacqua Dr. P. A. Abrahamsohn 《Cell and tissue research》1986,244(2):443-448
Summary An ultrastructural study of the features and distribution of collagen fibrils was performed in the endometrium of virgin and pregnant (2nd to 11th day) mice. Collagen-containing structures were observed in the cytoplasm of fibroblasts on the 2nd day of pregnancy. Treatment of tissues with lanthanum nitrate established that these structures were intracytoplasmic. Their association with lysosome-like bodies suggested the occurrence of intracellular digestion of collagen, probably connected with remodeling of the endometrial stroma prior to decidualization. On the 4th day of pregnancy, very few collagen fibrils were present in the intercellular space. From the 6th day of pregnancy onwards, thick collagen fibrils were observed between decidual cells. The diameter of these fibrils measured up to 300 nm whereas the fibrils present in the endometrium of virgin mice measured 40–68 nm. 相似文献
66.
带有氯霉素抗性基因标记的重组布氏杆菌S2的构建及其生物学特性 总被引:1,自引:0,他引:1
无法区分免疫接种和自然感染是限制布氏杆菌疫苗应用的主要原因。本研究通过基因同源重组技术,用氯霉素抗性基因(Cmr)替代布氏杆菌弱毒S2株的WbkC基因,筛选获得重组布氏杆菌rS2-WbkC株。试验发现,重组菌rS2-WbkC由原先的光滑型转变成粗糙型。rS2-WbkC在TSA培养基上传25代后仍能稳定表达氯霉素抗性蛋白。小鼠动物试验模型表明,rS2-WbkC与S2有相似的保护性,但rS2比S2具有更高的安全性。rS2-WbkC免疫小鼠后,其抗血清可通过平板凝集试验与S2免疫的血清相区分。本研究为布氏杆菌标记疫苗的研制提供了技术平台。 相似文献
67.
Asadulghani Nitta K Kaneko Y Kojima K Fukuzawa H Kosaka H Nakamoto H 《Archives of microbiology》2004,182(6):487-497
68.
The GRAM domain was found in glucosyltransferases, myotubularins and other membrane-associated proteins. So far, functions for majority of these proteins are yet to be uncovered. In order to address the evolutionary and functional significance of this family members, we have performed a comprehensive investigation on their genome-wide identification, phylogenetic relationship and expression divergence in five different organisms representing monocot/dicot plants, vertebrate/invertebrate animals and yeast, namely, Oryza sativa, Arabidopsis thaliana, Mus musculus, Drosophila melanogaster and Saccharomyces cerevisiae, respectively. We have identified 65 members of GRAM domain family from these organisms. Our data revealed that this family was an ancient group and various organisms had evolved into different family sizes. Large-scale genome duplication and divergence in both expression patterns and functions were significantly contributed to the expansion and retention of this family. Mouse and Drosophila members showed higher divergences in their proteins as indicated by higher Ka/Ks ratios and possessed multiple domains in various combinations. However, in plants, their protein functions were possibly retained with a relatively low divergence as signified by lower Ka/Ks ratios and only one additional domain was combined during evolution. On the other hand, this family in all five organisms exhibited high divergence in their expression patterns both at tissue level and under various biotic and abiotic stresses. These highly divergent expression patterns unraveled the complexity of functions of GRAM domain family. Each member may play specialized roles in a specific tissue or stress condition and may function as regulators of environmental and hormonal signaling. 相似文献
69.
Amandine Maréchal Andrew M. Hartley Thomas P. Warelow Brigitte Meunier Peter R. Rich 《BBA》2018,1859(9):705-711
Redox and CO photolysis FTIR spectra of yeast cytochrome c oxidase WT and mutants are compared to those from bovine and P. denitrificans CcOs in order to establish common functional features. All display changes that can be assigned to their E242 (bovine numbering) equivalent and to weakly H-bonded water molecules. The additional redox-sensitive band reported at 1736?cm?1 in bovine CcO and previously assigned to D51 is absent from yeast CcO and couldn't be restored by introduction of a D residue at the equivalent position of the yeast protein. Redox spectra of yeast CcO also show much smaller changes in the amide I region, which may relate to structural differences in the region around D51 and the subunit I/II interface. 相似文献
70.
Summary Urine of ddY/DAO mice lackingd-amino-acid oxidase contained 5.7 times more serine than that of normal ddY/DAO+ mice. Most of the serine wasd-isomer. The origin of thisd-serine was examined. Oral administration of 0.02% amoxicillin and 0.004% minocycline to the ddY/ DAO- mice for 7 days did not reduce the urinaryd-serine, indicating that thed-serine was not of intestinal bacterial origin. When the mouse diet was changed to one with different compositions, the urinaryd-serine was considerably reduced. Furthermore, starvation of the ddY/DAO- mice for 24 hours reduced the urinaryd-serine to 33% of the original level. These results indicate that most of the urinaryd-serine comes from the diet. However, the urine of the starved ddY/DAO- mice still contained 4.6 times mored-serine than that of the ddY/DAO+ mice, suggesting a part of the D-serine have an endogenous origin. 相似文献