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Shmuel Galili Hillel Fromm Dvora Aviv Marvin Edelman Esra Galun 《Molecular & general genetics : MGG》1989,218(2):289-292
Summary A streptomycin resistant Nicotiana plastome mutant, X/str
R6, was subjected to molecular analysis. In this mutant, a single nucleotide transition, C » T, in the chloroplast gene for ribosomal protein S12 alters codon 90 from proline to serine while the nucleotide sequence of the chloroplast 16 S rRNA gene is identical to that of the wild type. Mutant X/str
R6 thus differs from several previously reported streptomycin resistant chloroplast mutants which are altered in the gene for 16 S rRNA. 相似文献
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Summary Highly sensitive and specific synthetic substrates were used to quantitate cathepsin B and D activity in peritoneal macrophages in response to stimulation in vivo with mineral oil and thioglycollate. After intraperitoneal instillation of mineral oil the activity of cathepsin B increased significantly (to 15 300 units/mg protein versus 7 340 in saline controls), reaching values approaching those found in alveolar macrophages (18 400 units/mg protein). Significantly greater stimulation of enzyme activity was obtained after intraperitoneal instillation of thioglycollate (23 600 units/mg protein). Cathepsin D activity also increased significantly after both mineral oil and thioglycollate. However, the increase was moderate (from 806 to about 1 200 units/mg protein), remaining still more than six times lower-than in alveolar macrophages. The data are the first to demonstrate that cathepsin B activity can be stimulated in vivo in peritoneal macrophages by instillation of agents that induce acute inflammation. They also point to a differential control of expression of cathepsin B and D activity in both peritoneal and alveolar macrophages in spite of the common lysosomal origin of the two enzymes.Abbreviations Cbz
-N-benxyloxycarbonyl
- 2NA
2-naphthylamine
- EDTA
ethylenediamine tetraacetate
- DMSO
dimethylsulfoxide
- PBS
phosphate-buffered saline
- PM
peritoneal macrophage
- AM
alveolar macrophage 相似文献
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Glucocorticoid-Induced Cleft Palate in the Mouse: Two Major Histocompatibility Complex, H-2, Loci with Different Mechanisms 总被引:1,自引:0,他引:1 下载免费PDF全文
Isolated cleft palate is induced in the progeny of pregnant mice that are given glucocorticoids. The incidence varies among inbred strains and with dose and stage of gestation when the drug is given. One chromosomal region responsible for strain-associated differences in sensitivity is the major histocompatibility complex, H-2. H-2a is associated with susceptibility, H-2b with resistance. There appear to be both maternal and embryonic genetic factors affecting the sensitivity to glucocorticoids. In experiments reported here congenic strains of mice with H-2a, H-2d and H-2k haplotypes on a C57BL/10 genomic background were used. This allowed the determination of the effect on sensitivity by two H-2 subregions; the subregions are H-2K to I-E and I-C to H-2D. Methods included dose-response analysis and reciprocal cross analysis using dexamethasone given on day 12 of pregnancy. Results show that each subregion affects the strain's sensitivity to dexamethasone-induced cleft palate. The regression coefficients for B10.A-H-2a (45.4 ± 4.13) were different from those for B10.BR-H-2k (67.2 ± 10.8) and B10.D2-H-2d (70.5 ± 9.74). The estimated mean arcsine% cleft palate at 160 mg/kg was different for each strain: B10.A- H-2a, 53.1 ± 2.19; B10.BR-H-2k, 33.1 ± 2.27; B10.D2-H-2d, 25.0 ± 2.75. Different patterns of change in sensitivity were observed among the reciprocal crosses. In summary, the H-2K to I-E subregion seemed to influence both maternal and embryonic factors, whereas only embryonic factors were influenced by the I-C to H-2D subregion. These data suggest that the mechanisms affecting glucocorticoid sensitivity which are genetically encoded within each H-2 subregion are different, and there is an interaction between the alleles. The mode of interaction can be either complementation or epistasis. 相似文献
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Marvin R. Mark Edward F. Domino Seong S. Han Aurelio Ortiz Benjamin N. Mathews Sandra K. Tait 《Life sciences》1983,33(12):1191-1197
Parasympathetic denervation of the rat parotid gland by avulsion of the auriculotemporal nerve caused a marked and lasting decrease in gland weight. Parasympathectomy did not change the levels of choline in the gland but decreased by 60% the levels of acetylcholine (ACh) ten days after surgery and 65% at 28 days. It is puzzling that relatively high levels of ACh remained after parasympathetic denervation. The presence of additional cholinergic nerves that innervate the gland, or pass through it en route to other structures may account for some of the remaining ACh. Also, Schwann cells from denervated nerves might have contributed to some of the ACh. The existence of an extraneuronal source of ACh is considered. 相似文献
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