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61.
Anish Suri Ilan Vidavsky Koen van der Drift Osami Kanagawa Michael L Gross Emil R Unanue 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(3):1235-1243
We demonstrate in this study the great degree of specificity in peptides selected by a class II MHC molecule during processing. In this specific case of the diabetogenic I-A(g7) molecule, the P9 pocket of I-A(g7) plays a critical role in determining the final outcome of epitope selection, a conclusion that is important in interpreting the role of this molecule in autoimmunity. Specifically, we examined the display of naturally processed peptides from APCs expressing either I-A(g7) molecules or a mutant I-A(g7) molecule in which the beta57Ser residue was changed to an Asp residue. Using mass spectrometry analysis, we identified over 50 naturally processed peptides selected by I-A(g7)-expressing APCs. Many peptides were selected as families with a core sequence and variable flanks. Peptides selected by I-A(g7) were unusually rich in the presence of acidic residues toward their C termini. Many peptides contained short sequences of two to three acidic residues. In binding analysis, we determined the core sequences of many peptides and the interaction of the acidic residues with the P9 pocket. However, different sets of peptides were isolated from APCs bearing a modified I-A(g7) molecule. These peptides did not favor acidic residues toward the carboxyl terminus. 相似文献
62.
Kapoor Rupam Giri Bhoopander Mukerji Krishan G. 《World journal of microbiology & biotechnology》2002,18(5):459-463
The effects of application of two arbuscular mycorrhizal (AM) fungi Glomus macrocarpum and G. fasciculatum on shoot biomass and concentration of essential oil in Anethum graveolens L. and Trachyspermum ammi (Linn.) Sprague fruits were evaluated. Results revealed significant variation in effectiveness of the two AM fungal species. AM fungal inoculation in general improved the growth of the plants. On mycorrhization, the concentration of essential oil increased up to 90% in dill and 72% in carum over their respective controls. Glomus macrocarpum was more effective than G. fasciculatum in enhancing the oil concentration. The constituents of the essential oils were characterized by gas liquid chromatography. The levels of limonene and carvone were enhanced in essential oil obtained from G. macrocarpum-inoculated dill plants, while G. fasciculatum inoculation resulted in a higher level of thymol in carum. 相似文献
63.
Herbert Lazarus E. F. Barell S. Oppenheim Awtar Krishan 《In vitro cellular & developmental biology. Plant》1974,9(5):303-310
Summary Two lymphocytic cell lines were obtained from a single specimen of peripheral blood buffy coat from a patient with acute lymphoblastic
leukemia who concurrently developed classical infectious mononucleosis. These two cell lines exhibit distinguishing differences
in culture in parallel with reviously described differences in the cells when implanted into eonatal Syrian hamsters. These
observations suggest that the cell lines were derived from two pre-existing different classes or “stelines” of cells—one of
which resembles other cell lines derived from patients with acute lymphoblastic leukemia, whereas the other resembles cell
lines derived from other, patients with infecttious mononucleosis.
These studies were suported in part by research Grants C-6516 from the National Cancer Institute and FR-05526 from the Division
of Research Facilities and Resources, National Institutes of Health. 相似文献
64.
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66.
We have previously demonstrated that ischemic injury changed the density of peroxisomes into two distinct peaks, one with a normal density (1.21 g/cm3; Peak I) and a second peak with a lighter density (1. 14 g/cm3; Peak II).We studied the peroxisomes from both peaks under the Electron microscope. Examination of peak I following ischemia showed loss of matrix proteins and damaged limiting membranes with leakage of DAB positive material in direct proportion to the duration of ischemia. Upon reperfusion of the ischemic liver Peak I showed more severe damage to the organelle. These observations clearly demonstrated that ischemia reperfusion injury causes structural damage to peroxisomes. Interestingly ultrastructural examination of Peak II following ischemia showed evidence of perisomal proliferation with budding of existing peroxisomes and the presence of micro peroxisomes (changes similar to those noted under conditions leading to perisomal proliferation). However, peak II following reperfusion showed only damaged organelle. These observations underline the importance of peroxisomes in the response of the cell to ischemia-reperfusion injury. 相似文献
67.
Two spontaneous triploid plants of Trigonella corniculata (3n=24) were observed in a population raised from irradiated seeds. Up to seven trivalents per cell were observed. One of the plants appeared to be a double translocation heterozygote involving two non-homologous chromosomes, and therefore could form a quadrivalent, a ring trivalent and bivalents without corresponding univalents. 相似文献
68.
Barley plants (Hordeum vulgare L.) received foliar applications of 10–4 M gibberellic acid (GA3) and Kinetin (KN) individually and in combination at one or more of three growth stages: flag leaf appearance (I), ear emergence (II), and the first stage of senescence initiation in the flag leaf (III). Both plant growth regulators (PGR) hastened onset of senescence when sprayed at Stage I and/or Stage II. Treatment at Stage III, either alone or in combination with treatments at the other stages, tended to postpone senescence. Yield components also showed stage-dependent response: Stage I treatment increased the formation of total and bearing tillers, and Stage III treatment improved grain number and weight. However, while GA3 proved more effective than KN, the two together acted antagonistically. 相似文献
69.
70.
Fine structure of cytochalasin-induced multinucleated cells 总被引:7,自引:0,他引:7
A Krishan 《Journal of ultrastructure research》1971,36(1):191-204