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41.
Gentamicin is a very useful antimicrobial agent for the treatment of serious infections caused by gram-negative bacteria. However, it's low therapeutic index and potential ototoxic and nephrotoxic side effects necessitate frequent determinations of serum concentration to assist in maintaining therapeutic levels and avoiding toxic levels. Two bioassays and a latex agglutination inhibition card (LAIC) test were evaluated to determine gentamicin levels in nearly 100 patient sera. Results were compared with a radioimmunoassay (RIA). Two bioassays, the Bio-Monitor and the GentaSak, gave correlation coefficients of 0.987 and 0.982, respectively. The correlation coefficient for the LAIC test was 0.987. All three tests compared well with RIA in accurately detecting gentamicin levels in patient as well as simulated sera. The LAIC test, however, was more rapid, giving results within half an hour whereas bioassays required 6–8 hours for completion. The LAIC test was also found to be more economical. It provides a suitable alternative to RIA procedures in small laboratories and for performing stat tests since batching is not necessary. 相似文献
42.
Previously we described a cell line OCI-LY3 derived from a patient with non-Hodgkin's lymphoma. The cell line produced interleukin-6 (IL-6) mRNA and protein and demonstrated an autocrine pattern of growth for IL-6. Southern blot analysis of the IL-6 gene did not reveal any rearrangement. To determine whether the production of IL-6 by OCI-LY3 was due to subtle changes in the promoter of IL-6 or due to the expression of trans-acting factors chloramphenicol acetyltransferase (CAT) reporter constructs containing from -1,180 to +13 to -112 to +13 of a normal IL-6 gene were electroporated into the cell line. When these constructs are transferred into unstimulated fibroblasts, no CAT activity is seen; however, CAT activity is induced when the cells are stimulated with either IL-1 alpha, lipopolysaccharide (LPS), or cyclic adenosine monophosphate (cAMP) analogues. When the cell line OCI-LY3 was transfected with these constructs, CAT activity was observed; it was not necessary to stimulate the cells with exogenous factors to observe this activity. No CAT activity was observed in a second lymphoma cell line, OCI-LY13.1, that does not produce IL-6. These results suggest that the constitutive production of IL-6 by the cell line OCI-LY3 is due to the presence of trans-acting factors that stimulate the expression of IL-6 and not due to a cis-acting mutation of the IL-6 promoter. 相似文献
43.
Plant thioredoxin h: an animal-like thioredoxin occurring in multiple cell compartments 总被引:8,自引:0,他引:8
F Marcus S H Chamberlain C Chu F R Masiarz S Shin B C Yee B B Buchanan 《Archives of biochemistry and biophysics》1991,287(1):195-198
Thioredoxin h has been purified to electrophoretic homogeneity from spinach roots using a procedure devised for leaves. The root thioredoxin (h2 form) differed from chloroplast and animal thioredoxins in showing an atypical active site (Cys-Ala-Pro-Cys) but otherwise resembled animal thioredoxin in structure. Sequence data for a total of 72 residues of spinach root thioredoxin h2 (about 69% of the primary structure) showed 43-44% identity with rabbit and rat thioredoxin. Analysis of cell fractions from the endosperm of germinating castor beans revealed that thioredoxin h occurs in the cytosol, endoplasmic reticulum, and mitochondria. The present findings demonstrate a similarity between plant thioredoxin h and animal thioredoxins in structure and intracellular location and raise the question of whether these proteins have similar functions. 相似文献
44.
T Yee 《BioTechniques》1991,10(6):786-789
A computer program for digital image processing is described which can be implemented using scanning densitometer hardware pre-existing in most biology departments plus computer video hardware which may either pre-exist in the biology department or would represent a moderate upgrade over an already planned computer purchase. The primary purpose of this computer program is to provide contrast enhancement of faint or low contrast autoradiograph images and to implement background subtraction and digital smoothing methods which permit visualization of blurry electrophoresis bands against noisy backgrounds. However, the program also has modest editing capabilities that allow its use in the routine preparation of images for publication. Finally, the program has facilities for deblurring, edge enhancement and multiple image averaging, which give it usefulness in other forms of photographic analysis. 相似文献
45.
David I. Dunstan Debbie P. Lashta Susan I. Kikcio Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》1992,28(1):33-38
Summary The effects of sucrose concentration, addition of ammonium nitrate, and exposure to N6-benzyl-adenine (BA) on multiplication potential with shoots derived from shoot cultures of 17- to 20-yr-old Douglas fir trees
[Pseudotsuga menziesii (Mirb.) Franco] were compared. Each of these conditions, when compared independently, affected recurrent shoot multiplication
and influenced shoot development, as measured by the abundance of shoot apices. Sucrose concentration was influential, the
use of 25 g · liter−1 providing twice the multiplication obtained with 20 g · liter−1, and 14 × that obtained with the 30 g · liter−1 concentration routinely used (tree 11). Ammonium nitrate usage also improved multiplication, a 2.5 times improvement being
obtained after incorporation of 100 mg · liter−1 NH4NO3 into the medium (tree 33). Shoot cultures were responsive but relatively sensitive to addition of BA, the best improvement
in multiplication (5 times) being obtained with brief exposures to 3 mg · liter−1 BA (tree 11). Although shoot cultures were responsive to the conditions investigated, differences in shoot multiplication
and development were not displayed for several weeks. It was not possible therefore to repeat all the treatments with more
than one genotype; however, when this was possible a genotype-dependent variation in response was evident. 相似文献
46.
47.
Normal and Rous sarcoma virus (RSV)-transformed chick embryo fibroblasts growing on plastic dishes were incubated with ATP (γ32P) in situ to detect external cell surface protein kinase activity. Under the conditions employed, 32P was incorporated exclusively into proteins, specifically those at the external cell surface, as radioactivity was removed by tryspin treatment of labeled whole cells. In addition, exogenous histones were phosphorylated when added to the reaction mixture. Cyclic nucleotides had virtually no effect on 32P incorporation, suggesting that little or no cyclic nucleotide-dependent protein kinase activity was present at the external cell surface. Cell surface protein kinase activity was higher in transformed than in normal cells, and, using a temperature-sensitive RSV src mutant, this difference was shown to be transformation-specific. Several differences were observed in the cell surface proteins phosphoryllated in normal and transformed cells and at least two of these were transformation-specific. These data suggest that changes in external cell surface protein physphorylation are associated with RSV transformation and thus could play a role in the formation of the transformed cell phenotype. 相似文献
48.
49.
Enterobacteriaceae and Pseudomonas aeruginosa Recovered from Vegetable Salads 总被引:5,自引:4,他引:1
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Klebsiella, Enterobacter, and Serratia were recovered frequently in high counts from vegetable salads. Pseudomonas aeruginosa, although isolated frequently, was in lower counts. 相似文献
50.