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131.
Christophe Demaison Denis David Franck Letourneur Jacques Thèze Sentob Saragosti Moncef Zouali 《Immunogenetics》1995,42(5):342-352
Using CD19 B-cell selection and polymerase chain reaction-amplified cDNA libraries, we analyzed the peripheral immunoglobulin heavy chain variable repertoire of three healthy adult donors. Here we report that most of the CD19+ circulating B cells expressed unmutated V
H-D-JH rearrangements. By specific V
H family hybridization, we show that V
H gene family utilization in the periphery roughly corresponds to the complexity of these families in the germline and appears to be relatively constant among the analyzed subjects. However, sequence data of clones picked at random from one IgM cDNA library reveals that in spite of this random utilization, the V
H gene expression in naive circulating B cells is highly biased towards the expression of a limited set of V
H genes. As previously reported by others, this restricted mechanism is also found for the D and J
H segments.The nucleotide sequence data reported in this paper have been submitted to the GenBank/EMBL nucleotide sequence database and have been assigned the accession numbers Z47213-Z47243 and Z47349 相似文献
132.
133.
Qian Shi Pascal Verdier-Pinard Arnold Brossi Ernest Hamel Kuo-Hsiung Lee 《Bioorganic & medicinal chemistry》1997,5(12):2277-2282
(+)-Thiocolchicine (2b) was prepared from (±)-colchicine (1) in a five-step reaction sequence that included chromatographic separation of appropriate camphanylated diastereomers. Acid hydrolysis of the (+)-diastereomer, followed by acetylation, yielded the desired product 2b. (+)-Thiocolchicine has 15-fold lower inhibitory activity against tubulin polymerization than (−)-thiocolchicine, and is 29-fold less potent for inhibiting growth of human Burkitt lymphoma cells. The enantiomer 2a, prepared from the (−)-camphanylated diastereomer, had potent activity in all assays comparable to that of (−)-thiocolchicine prepared by other methods. These results support the hypothesis that the proper configuration of colchicine-related compounds is an important requirement for their anti-tubulin action. 相似文献
134.
The use of low doses of dopamine in intensive care medicine 总被引:3,自引:0,他引:3
V D'Orio D el Allaf J Juchmès R Marcelle 《Archives internationales de physiologie et de biochimie》1984,92(4):S11-S20
The dopamine alpha- and beta-adrenoceptor dose-response curves are investigated in four patients who are exempt from cardiovascular disease. A dose-related increase in CO, HR and SV is observed with infusion rates of up to 3 micrograms kg-1 min-1. With concentrations greater than 10 micrograms kg-1 min-1, both BP and SVR increase. Low-dose dopamine infusion less than 3 micrograms kg-1 min-1 is investigated in ten other patients. With this infusion rate, a selective renal vasodilation is induced without peripheral or cardiac beta-adrenoceptor activation. Dopamine is responsible for an increase in diuresis FENa, GFR and RBF. These properties are indicated in renal failure, and when haemodynamic support is required in cardiac failure, if an infusion rate of up to 10 micrograms kg-1 min-1 is able to reverse cardiac insufficiency. 相似文献
135.
A Rhodes-Feuillette G Mahouy M Bellosguardo C Gouget-Zalc J Périès 《Journal of medical primatology》1984,13(1):41-48
Significant and relatively stable levels of serum-interferon were demonstrated in a Callithrix jacchus population. This circulating interferon was acid-sensitive in all cases, classifying it as immune or "gamma-type" interferon. Our results in these hematopoietic chimeras suggest that the presence of immune-type or at least pH 2-sensitive interferon could be related to the presence of two allogenic lymphocyte populations in each marmoset. 相似文献
136.
What's new in lysozyme research? 总被引:49,自引:0,他引:49
The present review is focused on the main achievements realized in the lysozyme research field since the meeting held in 1972 to commemorate the fiftieth anniversary of the discovery of this enzyme. Despite of extensive structural, physico-chemical, crystallographic, genetic, immunological and evolutionary studies devoted to lysozymes, their biological role is still not exactly known. 相似文献
137.
Summary Bovine fibrinogen and the A and B chains of bovine fibrinogen have been subjected to chemical modification by a number of reagents and the effects of these procedures on the susceptibility of the proteins to thrombin hydrolysis is described. The reagents used were rose bengal (for photo-oxidation), 2-hydroxy-5-nitrobenzyl bromide, N-acetylimidazole, iodoacetic acid and diethyl pyrocarbonate. Evidence is presented which indicates that the tryptophan and tyrosine residues of fibrinogen are not involved to any great extent in the interaction of this protein with thrombin. Modification with iodoacetic acid suggests that methionine residues play a major role in such interactions, but the fibrinogen chains on which the important residues reside remain uncertain. The use of diethyl pyrocarbonate indicates the participation also of histidine in fibrinogen-thrombin interactions and that, whereas the histidine residues of the B chain are involved to a great extent, it appears that those of the Aa chain are not. The similarities which exist between the fibrinogen-thrombin and the -casein-chymosin systems are discussed.Abbreviations used DEP
diethyl pyrocarbonate (ethoxyformic anhydride)
- HNBB
2-hydroxy-5-nitrobenzyl bromide
- N-Acl
N-acetylimidazole
- PTC
phenylthiocarbamyl
- PTH
3-phenyl-2-thiohydantoin. 相似文献
138.
139.
J C Brochon P Wahl M Charlier J C Maurizot C Hélène 《Biochemical and biophysical research communications》1977,79(4):1261-1271
A new crystal form of a mitogenic lectin from pea seeds () has been obtained which is suitable for high resolution structural work. The crystals are orthorhombic, space group P212121, with unit cell dimensions: = 64.2Å, = 72. 7Å, = 108. 3Å. The asymmetric unit contains one protein molecule. 相似文献
140.