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1.
A F Frolov V E Rychnev V M Frolov M A Bala 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(11):93-96
The dynamics of circulating immune complexes (CIC) in comparison with the level of SH-groups of serum deproteinate and other characteristics of cell-mediated and humoral immunity (the reaction of the inhibition of antibodies, the levels of T-cells and their main subpopulations) was studied in 103 erysipelas patients and in 46 persons having had the disease at the acute period of this infection and at the periods between relapses. The elevated levels of CIC and SH-groups of serum deproteinate were found to be directly correlated with the inhibition index. The study showed that, as a rule, in patients with the elevated level of CIC the frequently relapsing form of erysipelas, accompanied by the formation of relative hypersuppressor-type secondary immunodeficiency and by a decrease in the functional activity of dermal macrophages, was observed. 相似文献
2.
Summary Responses of lentil in unsterile soils at low, medium and high levels of plant available soil P toGlomus fasciculatum inoculation were evaluated. It was observed that growth, dry matter accumulation, nodulation, and nitrogen fixation were considerably improved in VAM inoculated plants over uninoculated control at low and medium levels of plant available soil P. 相似文献
3.
Epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) synergistically stimulate placental lactogen (hPL) secretion by placental cells. To understand the mechanism of actions we have investigated a possible heterologous regulatory effect of EGF and IGF-I on each other's receptors. Pretreatment of the cells with IGF-I had no effect on [125I]-EGF binding or the down-regulation of EGF receptor. Pretreatment of the cells with EGF, concomitantly with IGF-I, had no effect on [125I]-IGF-I binding but it augmented the IGF-I down-regulation of IGF-I receptor. The time required to initiate the IGF-I-induced down-regulation of IGF-I receptor was reduced by 4 h in the presence of EGF. IGF-I-down-regulated decreased (P less than 0.05) receptor numbers were further decreased (p less than 0.05) in the presence of EGF. These results suggested that the synergistic effect of EGF and IGF-I seen in hPL secretion by placental cells is not due to direct heterologous hormone-receptor interactive effects. However, the effects seen may be due to a differentiating effect of EGF sensitizing the cells for responsiveness to IGF-I. 相似文献
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5.
Summary Sequence divergence between the 3 long terminal repeats (LTR) of avian reticuloendotheliosis virus (REV), deletion variant proviral clone 2-20-4, and spleen necrosis virus (SNV)—proviral clones 14-44, 60, and 70—was found to involve two classes of base substitutions: low-frequency interspersed and high-frequency clustered substitutions. Clones 2-20-4 and 14-44 have diverged 4.4% owing to low-frequency substitutions. In contrast, two high-frequency substitution segments have diverged by 30% and 29%, respectively. Clustered substitutions appear to be located either within or next to tandem repeats, suggesting their introduction concomitant with sequence deletions and duplications commonly associated with such repeats. A new 19-bp tandem repeat is found in clone 2-20-4. Its sequence could have evolved from the 26-bp repeats found in the SNV clones. 相似文献
6.
John J. Marchalonis Fatma Dedeoglu Hulya Kaymaz Samuel F. Schluter Allen B. Edmundson 《Journal of Protein Chemistry》1992,11(2):129-137
Although the amino acid sequence and three-dimensional structure of human immunoglobulin light chains have been known for more than 15 years, the location of antigenic markers characteristic of chains has not been determined. Here, we use a set of synthetic overlapping peptides to completely model the sequence of the chain Mcg and test these for the binding or rabbit and goat antisera specific for chain determinants. We assess peptide contributions to -antigenic reactivity and also to identify a portion of C-region where conformational factors contribute to the antigenicity. Specific determinants occur both in the constant and variable (first and third framework) domains of the molecule. The fourth framework of the variable region, a segment specified by the joining gene, is also recognized and cross-reacts antigenically with the homologous region of T cell receptor chains. Major specific determinants are localized in the N- and C-terminal segments, which are linear and devoid of major conformational folding. Other segments that are strongly antigenic, such as the third framework of the V region (residue 78–93) and a segment of the constant region (residues 177–192), show strong conformational dependence in antigenicity. 相似文献
7.
Rafael Balaña Fouce Maria I. Escribano Jose M. Alunda 《Molecular and cellular biochemistry》1991,107(2):127-133
Summary The putrescine uptake/efflux regulation and their regulatory role on intracellular polyamine pools have been studied in the parasitic protozoa Leishmania infantum. Putrescine uptake was age-dependent with maximal values in logarithmic phase promastigotes and minimal in stationary phase. Moreover, putrescine uptake was activated in response to depletion of intracellular polyamines by alpha-difluoromethylornithine (DFMO) — a well known irreversible enzyme-activated inhibitor of ornithine decarboxylase. Kinetic studies of putrescine uptake induction showed a notable rise in Vmax without Km changes, suggesting a de novo synthesis of putrescine carriers. Putrescine uptake was able to replenish polyamine content and also to recover the proliferative rate in cells treated during 24 hours with DFMO. 相似文献
8.
Characterization of two mutant metJ proteins with reduced, temperature-dependent capacity to regulate Escherichia coli K-12 met regulon elements. 总被引:1,自引:1,他引:0
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At 28 degrees C, but not at 34 or 42 degrees C, strains with the metJ193 allele repressed chromosomal met genes but not a plasmid-borne met promoter. Increasing the metJ193 gene dosage to two copies resulted in overrepression of chromosomal and plasmid-borne met promoters at 28 degrees C. Suppressing the metJ185 amber mutation with supF (tRNATyr) produced the MetJ185F protein. Strains producing MetJ185F repressed chromosomal met promoters but not a plasmid-borne met promoter at 42 degrees C. These are the first known defective MetJ proteins with documented temperature-dependent function. 相似文献
9.
Antimutagenicity of water and chloroform extracts of dried myroblan Terminalia chebula was determined against two direct acting mutagens, sodium azide and 4-nitro-o-phenylenediamine (NPD) in strains TA100 and TA1535, and TA97a and TA98 of Salmonella typhimurium respectively and S9-dependent mutagen 2-aminofluorene (2-AF) in TA97a, TA98 and TA100 strains. Water extract reduced NPD as well as 2-AF induced his+ revertants significantly but did not have any perceptible effect against sodium azide included his+ revertants in TA100 and TA1535 strains of S. typhimurium. The pre-incubation studies, where the extract was incubated at 37 degrees C for 30 min with the said mutagen prior to plating, enhanced the inhibitory effect. Autoclaving the water extract reduced the inhibitory effect but the reduction in the effect was not significant. No inhibitory effect was observed in any of the strains and against any of the test mutagens with chloroform extract. 相似文献
10.