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1.
In the accompanying paper it has been shown that two major groups of proteins (low-sulphur and high-sulphur) of ovine wool, horn, and hoof contain similar components although the overall proportions of the groups of proteins and the relative proportions of components within the groups may show significant differences. In the present paper it has been shown for five other species (echidna, hedgehog, rabbit, ox and man) that the hard keratins produced by one animal contain the same groups of protein components but in different relative proportions. The wide apparent differences in the type and relative proportions of the the low-sulphur components which comprise the major constituent proteins of the microfibrils suggest that microfibrils can tolerate a considerable variation in the constituent proteins and still produce functional structures. The low-sulphur protein components are sufficiently well resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis to make this procedure potentially useful for animal identification and classification. 相似文献
2.
M C Datta J Josephs M E Tolbert J Anderson H Dowla 《Biochemical and biophysical research communications》1986,137(1):69-75
Normal adult Sprague-Dawley rats were made anemic by repeated phlebotomy. Ion-exchange chromatography of anemic blood showed newborn like hemoglobin proportions, involving the same six hemoglobin components as is found when newborn and adult blood are compared. However, acetylsalicylic acid intake during anemia failed to demonstrate the changes in hemoglobin proportions, either totally or partially, depending upon the doses. Since acetylsalicylic acid inhibits prostaglandin synthesis, the data suggest that one or more prostaglandins may be involved in the process of reverse switching of hemoglobin in adult rat erythroid cells during erythropoietic stress. 相似文献
3.
Measurements of the palatal components: premaxillary, maxillary, and palatine length are made on the adult skulls of 19 male
and 21 femalePapio cynocephalus anubis. The relative contributions of each of these components to overall palatal length are compared between the sexes. It is found
that the proportions are the same for the two sexes and concluded that sexual dimorphism observed in the adult is not the
result of differential growth of one component. 相似文献
4.
A. H. Lachke M. C. Srinivasan S. S. Deshmukh M. V. Deshpande 《Biotechnology letters》1987,9(2):147-150
Summary The mutants ofPenicillium
funiculosum viz. N-4, BU-36 and Cu-1 producing different proportions of cellulase components have been isolated. Results of saccharification experiments using various lignocellulose substrates with culture filtrates of these mutants suggested criteria for their selection. 相似文献
5.
Endothelial cells derived from human pulmonary arteries incorporate (3H)-glucosamine and 35SO4 into glycosaminoglycans and into the carbohydrate side chains of glycoproteins. These 3H/35S-carbohydrate chains were isolated from cells and culture medium after Pronase digestion. The 3H/35S-glycosaminoglycans were separated from the 3H/35S glycopeptides by chromatography on Sephadex G-50. The distribution of cellular glycosaminoglycans and glycopeptides indicated that 30–60% of the cellular 35S-glycopeptides may be associated with the matrix components that are synthesized by the cell and attached to a plastic substratum. Human pulmonary arterial endothelial cells were grown on collagen or on a matrix derived from vascular smooth muscle cells in order to investigate how smooth muscle cell extracellular matrix components may regulate the synthesis of endothelial cell glycoconjugates. Endothelial cells grown on plastic release various proportions of the glycoconjugates they synthesize into the culture medium. However, these same cells, when grown on substratum composed of extracellular matrix materials, synthesized altered proportions of cell-associated glycosaminoglycans and reduced the levels of total glycosaminoglycans they released into the culture medium. Thus the growth of endothelial cells on a matrix of smooth muscle cell components indicates that the glycosaminoglycan materials released into the culture medium by cells grown on a plastic substratum may not be an accurate reflection of the levels or composition of extracellular matrix materials made by endothelial cells in vivo. 相似文献
6.
7.
V D Artemenko L G Ivanova V P Nenashev G I Kuznetsova N I Ochkina 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(11):37-41
A successful attempt to use analytico-experimental approach to the evaluation of experimental data for the scientifically based calculation of the composition of complex culture media, intended for growing pathogenic microorganisms, has been made. The method is based on the evaluation of the specific growth-stimulating and toxin-forming activity of the components of a given culture medium, which are determined by the number of cells grown in the variants of the medium with the limited amount of one of its components. The use of the analytico-experimental balancing method makes it possible to develop culture media with the optimal composition ensuring the definite yield of the target product rather quickly and economically by experimenting on the minimal number of variants equal to the number of the components of the medium. The investigation carried out by means of the analytico-experimental method has revealed that on the basis of peptic serum albumin hydrolysate, pancreatic casein hydrolysate and fodder yeast extract, alongside the culture medium described in an earlier work and containing these components in the proportion 4:2:1, two other media, containing the above components in the proportion 2:4:1 and 3:4:2, can be obtained, these media providing the optimal conditions for, respectively, the toxin formation and growth of C. perfringens, type A. 相似文献
8.
The method for analysis of the ontogenetic changes of size and shape based on the decomposition of Kullback divergence into parts corresponding to the principal components, found for intragroup variability of signs is suggested. The application of this method is illustrated by the analysis of age changes of body proportions for boys 3-17 years old. Before the pubertal period the stable tendency to a relative lengthening of extremities which changes to a contrast one at age of 12-14 has been pointed out. The definitive differences of proportions to a considerable extent is determined by variability of biological age at the group of children. 相似文献
9.
D Poccia 《The Journal of experimental zoology》1988,246(1):57-64
Fragments of sea urchin testicular tissue were cultured at 15 degrees C in serum-supplemented seawater for 5 weeks. Cells whose DNA had been pulse-labelled with 3H-thymidine at the beginning of the experiment were followed by autoradiography, and counts were made of the proportions of each male germ-line cell type from sections of tissue at several time points. Differentiation of spermatogonia to mid-spermatids occurred within the first 10 days, with a decline of about 40% in the total number of spermatogonia and an increase of 250% in the number of mid-spermatids. Thereafter, no changes occurred in the proportions of germ-line cells, although tissue integrity was maintained throughout. The results indicate that sea urchin male germ-line cells can complete meiosis and the first stages of spermiogenesis including nuclear condensation and cytoplasmic reduction in culture with kinetics similar to those in vivo. The system should permit analysis of factors responsible for male germ-cell differentiation. 相似文献
10.
The emanation of Petunia (Petunia hybrida) flowers fed with various substrates has been found to be a mixture of at least four gaseous components, one of which being ethylene. The relative proportions of these gases change with the substrate, which therefore means that the compounds generally accepted as ethylene precursors are not all converted primarily into ethylene. 相似文献
11.
To study the degradation of a xenobiotic that requires a mixed culture it is essential to monitor the proportions and to control the population dynamics of the component strains. For these purposes fluorochromising techniques and multi-parametric flow cytometry were used to follow Rhodococcus erythropolis K2-3 and Ochrobactrum anthropi K2-14, both of which are needed to degrade 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). Although the two strains can grow in constant proportions in mixed cultures on other substrates, 2,4-DB could not be degraded as a sole substrate in a continuous process and R. erythropolis K2-3 was clearly impaired in the binary mixture. Addition of a second, easily assimilable substrate (xylitol) in appropriate concentrations (empirically determined) helped this strain survive, and thus facilitated complete degradation of the xenobiotic. This combination of substrates was found to stabilise the growth of R. erythropolis K2-3 and, consequently promoted the action of O. anthropi K2-14. Thus, the two organisms became established in constant proportions in a continuous process until reaching steady state. Consequently, multiplication and cell division activities of the two components of the binary culture were high and reached similar values to those attained when they are grown in pure culture. 相似文献
12.
Optimization of bagasse,nutrients and initial moisture ratios on the yield of penicillin in solid-state fermentation 总被引:1,自引:0,他引:1
Domínguez M. Mejía A. Revah S. Barrios-González J. 《World journal of microbiology & biotechnology》2001,17(7):751-756
An advanced solid-state fermentation (SSF) system (liquid medium absorbed on an inert support) has been applied to antibiotic production. The main components of this solid medium are: support (sugarcane bagasse), nutrients and water. The first two are solids and have to be considered to calculate the initial moisture content (IMC) of the medium. Earlier work indicated the importance of using high IMCs and concentrated media to obtain high penicillin yields in SSF. Nevertheless, the present work shows that high values of IMC or nutrients content can stimulate or inhibit penicillin production, depending on the strategy used to compensate this change (i.e. the proportions of the other two components). Conversely, increasing bagasse content always showed an inhibitory effect on the production. Since penicillin production depends on the combinations of these components, a global approach was used. The effect of the proportions of the three components on penicillin production was studied by means of a triangle of combinations and a 3D graph. It was possible to establish that high penicillin production is only obtained in a zone of low support content (10–12.5%). Surprisingly, one production maximum was observed in a zone of low moisture and high nutrients content (62 and 25.5% respectively); and another one in a zone of high moisture and a relatively low nutrients concentration (75.5 and 12.4% respectively). 相似文献
13.
Curve resolution into Gaussian components of the absorption spectra during the varying stages of the Shibata shift in dark grown, irradiated leaves of barley indicates that the chlorophyll a forms formed after irradiation consist of the same main components which have been reported to be present in all hitherto investigated plant materials (peak values in the red region 662, 670, 677 and 683 nm, respectively) but in varying proportions. The spectra during the Shibata shift proper can be satisfied by a mixture of two single components gradually changing their proportions, although a four component system gives a still better fit to the measured absorption curves. It is also shown that curves taken before and after the shift and added together in the appropriate proportions will match the absorption spectrum measured with peak at the isosbestic point (after ca. 15 min at room temperature). 相似文献
14.
一种白僵菌代谢产物中生物活性物质的研究 Ⅰ.具有清除自由基的活性物质的分离和制备 总被引:3,自引:0,他引:3
通过对白僵菌Beauveriasp.的液体培养及生物活性测定,发现该菌代谢产物具有较强的清除自由基的活性,我们用甲醇成功地提取出该活性成分,同时用色谱等方法对该活性成分进行了分离和制备,并用高压液相色谱法和DPPH薄层试验对其纯度及活性进行了检验,得到了具消除自由基活性的纯化合物P-24-3。 相似文献
15.
Effect of growth conditions on production of rhamnose-containing cell wall and capsular polysaccharides by strains of Lactobacillus casei subsp. rhamnosus. 总被引:1,自引:0,他引:1
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Strains of Lactobacillus casei subsp. rhamnosus possessing two cell wall polysaccharides, a hexosamine-containing H-polysaccharide and a rhamnose-containing R-polysaccharide, were examined for the effect of growth conditions on the production of these two components. In strain NCTC 6375, R- and H-polysaccharides accounted for an estimated 44 and 20%, respectively, of the cell wall for organisms grown in batch culture with glucose as the carbohydrate source. Growth on fructose-containing media reduced the amount of R-polysaccharide by approximately 50% without affecting the amount of H-polysaccharide. Subculture of fructose-grown organisms in glucose restored the original proportions of the two polysaccharides. Galactose- and sucrose-grown cells behaved similarly to glucose-grown cells with respect to polysaccharide production, whereas growth in rhamnose or ribose showed values close to those for fructose-grown cells. Continuous culture of strain NCTC 6375 for more than 100 generations showed a gradual and irreversible reduction of the R-polysaccharide to less than 5% of the cell wall and an increase of the H-polysaccharide to 40% of the cell wall. Other type culture strains of L. casei subsp. rhamnosus, NCIB 7473 and ATCC 7469, behaved similarly in batch and continuous culture. In contrast, strains of L. casei subsp. rhamnosus isolated at the Institute of Dental Research showed phenotypic stability with respect to the relative proportions of R- and H-polysaccharides in both batch and continuous culture. Changes in polysaccharide composition of type culture strains were also mirrored in changes in the immunogenicity of the two components and resistance to the rate of enzymic lysis of whole organisms. For L. casei subsp. rhamnosus strain NCTC 10302 the R-polysaccharide is present entirely as capsular material. The amount of R-polysaccharide produced was also markedly dependent on the carbohydrate component of the medium in batch culture and both dilution rate and nature of the limiting carbohydrate in continuous culture, varying over a 10-fold range, whereas the cell wall H-polysaccharide remained constant. 相似文献
16.
It is shown that the lipids from 5 extreme thermoacidophile bacteria of the Caldariella group—2 isolates of Sulfolobus acidocaldarius, one of Thermoplasma acidophila, and 2 of the MT series—are all based on the same type of cyclic diether combining glycerol and one of a series of very unusual C40 isoprenoid diols. The relative proportions of the different C40 components in each isolate have been determined. 相似文献
17.
The article deals with the development of a new method for the extraction of intracellular glycolytic metabolites from bacterial cells. The study has been made on the culture of E. coli B/r CSH. In accordance with this method, the same bacterial filter is used for both filtration (the removal of the culture fluid) and the extraction of low-molecular components of the cells with perchloric acid. The advantage of this method is the absence of unnecessary operations due to the use of a filter installation designed by the author. Quantitatively, this method yields better and reproducible results. The filtration capacity of different types of filters has been analyzed. The optimal time for the extraction of low-molecular cell components has been determined. A change in the concentration of pyruvate in the process of the cellular cycle of E. coli synchronous culture grown in the presence of glucose has been shown to occur. The newly developed method of extraction can be used not only for E. coli, but also for cells of other types. 相似文献
18.
Giemsa Stain for the Diagnosis of Bovine Babesiosis. I. Staining Properties of Commercial Samples and Their Component Dyes 总被引:1,自引:0,他引:1
J. R. SAAL 《The Journal of eukaryotic microbiology》1964,11(4):573-582
SYNOPSIS. Studies on the composition of commercial Giemsa stain and its effect upon staining quality are reported. These studies were supplemented by observations on the preparation of the components of Giemsa stain and their staining properties in aqueous solution, in Nocht's solution, and in laboratory prepared Giemsa stains containing one azure component. Five groups of commercial batches were differentiated on the basis of their staining reactions on thick and thin films of bovine blood containing Babesia bigemina and B. argentina. Spectrophotometric and chromatographic analysis showed that four groups differed in the proportions of the thiazine components present, while the fifth-group did not appear to be Giemsa stain. Comparison of their staining effects with those obtained with each component in laboratory prepared stains indicated that the major effects of commercial batches on both blood cells and parasites were due to the thiazine component or components in highest proportions, with satisfactory staining of protozoa associated with those batches containing high proportions of methylene blue and azure B and low proportions of the remaining thiazine components.
The function of each component of Giemsa stain is defined and the need for the proper balancing of thiazine eosinates with free azure is shown. Close correlation was obtained between analysis by spectrophotometry and chromatography and direct staining tests when samples initially with low MX values were re-examined spectrophotometrically after removal of their methylene violet content. The existence of a leuco form of eosin is reported and its possible significance to the Romanowsky effect is discussed. 相似文献
The function of each component of Giemsa stain is defined and the need for the proper balancing of thiazine eosinates with free azure is shown. Close correlation was obtained between analysis by spectrophotometry and chromatography and direct staining tests when samples initially with low MX values were re-examined spectrophotometrically after removal of their methylene violet content. The existence of a leuco form of eosin is reported and its possible significance to the Romanowsky effect is discussed. 相似文献
19.
Just noticeable differences in component concentrations modify the odor quality of a blending mixture 总被引:1,自引:0,他引:1
Le Berre E Béno N Ishii A Chabanet C Etiévant P Thomas-Danguin T 《Chemical senses》2008,33(4):389-395
The odors we perceive are mainly the result of mixtures of odorants that, however, are commonly perceived as single undivided entities; nevertheless, the processes involved remain poorly explored. It has been recently reported that perceptual blending based on configural olfactory processing can cause odorant mixtures to give rise to an emergent odor not present in the components. The present study examined whether specific component proportions are required to elicit an emergent odor. Starting from the composition of a ternary target mixture in which an emergent pineapple odor was perceived, 4 concentration levels of each component were chosen to elicit just noticeable differences (JNDs). Each combination of levels was used to design sample mixtures. Fifteen subjects evaluated the intensity, typicality, and pleasantness of each sample mixture against the target mixture in a paired-comparison protocol. Statistical modeling showed that a variation of less than 1 JND in one of the components was sufficient to induce a significant decrease in pineapple odor typicality in the ternary mixture. This finding confirms previous findings on perceptual blending in simple odorant mixtures and underscores the human ability to discriminate between odor percepts induced by mixtures including very similar odorant proportions. 相似文献
20.
In the present studies, we have made several unique observations. First, we have shown that cytosolic phosphatidate phosphohydrolase from adipose tissue subjected to butyl-agarose chromatography was resolved into four different components. These components, designated as passthrough (PT), D150, D250 and E, were present in the proportions of 51:7:24:16, respectively, in the rat adipose cytosol. Comparison of the properties of these components revealed some similar properties, and also several differences. These components showed the same pH optimum, required Mg2+ for activity and were inhibited by N-ethylmaleimide, indicating a requirement of active sulfhydryl groups for activity. These components differed from one another with respect to hydrophobicity, sedimentation behavior, Stokes diameter, Km values, thermolability and susceptibility to proteinase treatment. Second, we have shown that each component of this system was associated with lipids which were found to be essential for the catalytic activity. Perturbation of this association by organic solvent or by adding excess amounts of exogenous lipids resulted in the loss of enzyme activity. Finally, we analyzed lipid composition of individual components. These studies suggest that the multi-component system of Mg2+-dependent phosphatidate phosphohydrolase may be a part of the cytomembrane network. 相似文献