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Dr. Heidrun Lauke Katrin Behrens Adolf-Friedrich Holstein 《Cell and tissue research》1989,255(3):475-479
Summary Numerous mitoses were noted in testicular tissue from adult men with early germ cell tumors. More than 15 Leydig cells undergoing mitosis were found in the interstitial compartment. The presence of specific crystalline intracytoplasmatic inclusions demonstrated for the first time that differentiated Leydig cells are capable of proliferation. Occasionally cells are difficult to discriminate during mitosis. To establish reference criteria, the light- and electron-microscopic features of the following mitotic cells were examined: Leydig cells, fibroblasts, perivascular cells, peritubular cells, and lymphocytes. Supplementary mitoses in germ cell tumors and in a case of Leydig cell tumor were investigated. In the literature, only single reports of mitoses in Leydig cells are available. The frequent incidence of Leydig cell mitosis in early germ cell tumors may be due to the presence of growth-promoting factors in the testicular tissue. 相似文献
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Radiolabelled calmodulin has previously been used to screen cDNA expression libraries to isolate calmodulin-binding proteins.
We have modified this technique for the isolation of plant calmodulin-binding proteins. [35S]-methionine was used instead of the inorganic [35S]-sulfate, or125I used in previous methods. In addition, theE. coli pET expression system was chosen to obtain high levels of recombinant calmodulin at the time of labelling. The procedure
thus takes into account both the specific activity of the probe and the amount of protein necessary for screening a large
number of filters. Here we describe in detail a procedure for the production and purification of [35S]-recombinant calmodulin and the use of the radiolabelled protein as a probe to screen plant cDNA expression libraries. The
[35S]-labeled calmodulin probe easily detects the λICM-1 phage encoding a partial mouse calmodulin-dependent protein kinase II
that was previously isolated using a [125I]-calmodulin probe (Sikela and Hahn, 1987). Subsequently, a tobacco root cDNA expression library was screened and a positive
clone encoding a calcium-dependent calmodulin-binding protein was isolated. 相似文献
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Katrin Kausch Clemens R. Müller Tiemo Grimm Kenneth Ricker Marcella Rietschel Sabine Rudnik-Schöneborn Klaus Zerres 《Human genetics》1991,86(3):317-318
Summary Two recent articles have reported the linkage of a gene for recessive spinal muscular atrophy (SMA) on the chromosome region 5q11.2–13.3. Our data show no linkage of the dominantly inherited forms of SMA to this chromosome region. 相似文献
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Katrin Lineruth 《Genetica》1986,78(1):33-37
The protein synthesis pattern of a set of stage and tissue specific proteins has previously been described in Drosophila melanogaster. The analysis of this set of follicle cell proteins (Fc proteins) is here extended to cover several sibling species of Drosophila melanogaster, namely D. simulans, D. mauritiana, D. erecta and D. yakuba. Even though a similar set of proteins were synthesized in these species, minor differences in size of the proteins were found between the species. Some of the species exhibited variation within species. 相似文献
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Recombinant human interleukin 1 alpha: purification and biological characterization 总被引:29,自引:0,他引:29
U Gubler A O Chua A S Stern C P Hellmann M P Vitek T M DeChiara W R Benjamin K J Collier M Dukovich P C Familletti 《Journal of immunology (Baltimore, Md. : 1950)》1986,136(7):2492-2497
Interleukin 1 (IL 1) is a polypeptide hormone produced by activated macrophages that affects many different cell types involved in immune and inflammatory responses. The cloning and expression of a murine IL 1 cDNA in Escherichia coli encoding a polypeptide precursor of 270 amino acids has been reported, and expression of the carboxy-terminal 156 amino acids of this precursor in E. coli yields biologically active IL 1. By using the murine IL 1 cDNA as a probe, we have isolated its human homolog from cDNA generated to lipopolysaccharide-stimulated human leukocyte mRNA. Nucleotide sequence analysis of this cDNA predicts a protein of analysis of this cDNA predicts a protein of 271 amino acids (termed IL 1 alpha) which shows congruent to 61% homology to its murine counterpart but only 27% homology to a recently characterized human IL 1 precursor (IL 1 beta). We have expressed the carboxy-terminal 154 amino acids of IL 1 alpha in E. coli, purified this protein to homogeneity, and have compared it with pure recombinant murine IL 1 in several different IL 1 assays based on murine and human cells. Recombinant IL 1 is capable of stimulating T cell and fibroblast proliferation and inducing fibroblast collagenase and prostaglandin production, thus proving that a single molecule has many of the activities previously ascribed to only partially purified IL 1 preparations. Our results indicate that there exists a family of at least two human IL 1 genes (alpha and beta) whose dissimilar protein products have similar biological activities. 相似文献
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