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1.
Concentrations of the elements C, N, Fe, Na, K, Ca and Mg were analysed by chromatography and atomic absorption spectrometry in the whaleworm Anisakis simplex sensu lato. Nearly all mean inorganic element concentrations measured were higher in adult worms than in larval forms. Similarly, adults contained significantly higher nitrogen (i.e. lower C/N ratio values) than either eggs or larvae. Evidence for the significance of the parasitic life cycle stage and the systematic position of their hosts on the element concentration variability is discussed. 相似文献
2.
Gregory Plunkett Donald F. Senear Glen Zuroske Clarence A. Ryan 《Archives of biochemistry and biophysics》1982,219(2):463-464
Proteinase inhibitors I and II were purified to electrophoretic homogeneity from leaves of tomato plants induced by either wounding intact plants or by supplying excised plants with the proteinase inhibitor inducing factor. Affinity chromatography with chymotrypsin-Sepharose was employed as a final purification step for each inhibitor. The tomato leaf inhibitors are very similar to potato tuber inhibitors I and II in subunit molecular weight, composition, and inhibitory activities against chymotrypsin, trypsin, and subtilisin. However, unlike the potato tuber which contains multiple isoinhibitors by isoelectric focusing, the tomato leaf exhibits only two isoinhibitor forms of inhibitor I and a single form of inhibitor II. The molecular weight of native potato inhibitor I was reevaluated by rigorous ultracentrifugal analysis and compared with data from previous analyses. The data confirm that native inhibitor I has a native Mr of about 41,000 and is a pentamer. Inhibitor II has a molecular weight of near 23,000 and is a dimer. 相似文献
3.
Substrate-induced H+ extrusion was studied in dilute (0.04–0.5 mg dry mass per mL) unbuffered suspensions ofS. cerevisiae. Wild-type strains 196-2 and K and 196-2-derived mutants altered in hexose transport, glucosephosphate isomerase, mannosephosphate
isomerase, pyruvate kinase, and arho petite mutant were characterized as to growth, biochemical and H+-pumping properties. Their H+ extrusion differed, depending on strain, growth conditions, and the H+-efflux-inducing substrate; the efficiency of the process depended critically on the balance between substrate uptake, its
dissimilation, attendant mobilization of energy sources and build-up of acidity sources in the cell, and the energy supply
to H+excreting systems. 相似文献
4.
Ruth C. Steinkamp Clarence L. Young Dolores Nyhus Arnold E. Greenberg 《The Western journal of medicine》1968,109(2):126-133
The amount of sodium ion in water used for ingestion may be critical in effective use of a low sodium dietary regimen. Waters containing not over 20 mg of sodium per liter are provided for in the sodium restricted diets set forth by the American Heart Association. For diets containing more than 500 mg of sodium a day, waters of greater sodium content may be used if proper dietary adjustments are made.While assessment of the long-term average sodium content of a community water supply is difficult, the determined values for sodium lend to classification within range categories. The larger community water supplies in California are presented within several range categories of sodium content.The more commonly used water softeners add sodium to water. The sodium-restricted patient should be cautioned against their use. Similar consideration should probably be given to water supplies of retirement communities where the potential for disorders requiring sodium restriction is greater than in the general population. 相似文献
5.
M. Pascual J. Balanya A. Latorre L. Serra 《Journal of Zoological Systematics and Evolutionary Research》1997,35(4):159-164
The disribution ranges of Drosophila azteca and D. athabasca overlap in northen California and southern Oregon. Seven populations, four of which are located in this area, were studied. Large random amplified polymorphic DNA (RAPD) variation was found within species; nevertheless, more than half the primers used in the study yielded greater diofference between than within species. A nested analysis of molecular variance (AMOVA) showed that the variance between populations within species was significantly greater than zero for 55% of the oligonucleotides used, which provided evidence for an underlying geographical structure of these populations. Specimens of D. azteca and D. athabasca from Salem (OR), where both species were collected together, presented the highest similarity encountered between species. 相似文献
6.
Clarence E. Jones Catherine T. Lee Wayne Skinner Peggy Koyama DeAnn Prescott 《Cancer immunology, immunotherapy : CII》1984,18(2):82-86
Summary The immune status of C57BL/6J mice implanted with Lewis T241 fibrosarcoma or Lewis lung (LL) carcinoma was investigated on days 14 and 28 after implantation. Splenic lymphocyte responses were assessed in mitogen (Con A, LPS) mixed lymphocyte culture (MLC), natural killer (NK), graft-vs-host (GVH), and interleukin production assays. Except for NK-cell cytotoxicity, all other immunologic parameters were either comparable to those in medium-implanted controls or augmented. NK cytotoxicity was reduced in both tumor-bearing groups on day 28. The provision of NK potentiation therapy (-interferon, polyinosinic: polycytidylic acid) to T241 mice under various treatment conditions did not have any significant effect on lung metastasis or survival.The results of this study do not support the thesis that T241-or LL-bearing C57BL/6J mice are generally immunosuppressed. Indeed, when immune functions were assessed on the basis of total splenic activity, each of the measured immunologic parameters was substantially greater in animals with tumors than without. Further it seems improbable, considering the magnitude of the NK-cell defect in T241 mice on days 14 and 28 after implantation and the absence of a therapeutic response to NK-cell stimulants, that NK-cell cytotoxicity is intrinsically associated with resistance to tumor progression in this model. 相似文献
7.
Rangil Singh Consuelo M. Perez Cynthia G. Pascual Bienvenido O. Juliano 《Phytochemistry》1978,17(11):1869-1874
Five rices (Oryza sativa L.) differing in final grain size were studied at the midmilky stage to determine if any factor could be identified which might limit rate of starch accumulation. Only UDP glucose pyrophosphorylase activity increased with increasing grain size. Detached rice panicles incubated in liquid medium containing 1% sucrose and 0.1% glutamine, in addition to minerals and vitamins, produced grains similar to those on intact plants. Sucrose level (0–1.5%) in the medium determined the extent of dry matter and starch accumulation and influenced physiological development of the ripening grains. Chemical and enzymic composition of the grain were similar to previously reported levels in grains of intact panicles analysed at regular intervals after anthesis. Addition of 3-P glycerate or K+ to the medium did not improve dry matter accumulation in the developing grain. 相似文献
8.
I Randen D Brown K M Thompson N Hughes-Jones V Pascual K Victor J D Capra O F?rre J B Natvig 《Journal of immunology (Baltimore, Md. : 1950)》1992,148(10):3296-3301
Using hybridoma technology we established a panel of human monoclonal rheumatoid factors (RF) from the synovial tissues of two patients with rheumatoid arthritis (RA), and one patient with polyarticular juvenile RA. Nucleotide sequence analysis of the V regions of these RF indicates that two independently derived antibodies from one of the RA patients are clonally related. One of these antibodies appears to be close to germ-line configuration, whereas the other has accumulated a total of 36 substitutions in both H and L chains. Measurements of the affinity for human IgG of the two RF show that the extensively mutated RF has 100-fold higher affinity for IgG than the RF close to germline. These findings indicate that IgM RF in RA can undergo affinity maturation and suggest that certain RF may be the product of an Ag-driven immune response. 相似文献
9.
Localization of ouabain-sensitive,potassium-dependent nitrophenyl phosphatase in the rectal gland of the spiny dogfish,Squalus acanthias 总被引:2,自引:0,他引:2
Tissue from the digitiform rectal gland of the spiny dogfish, Squalus acanthias, was fixed briefly by formaldehyde perfusion and studied for the specificity and localization of p-nitrophenyl phosphatase (NPP'ase) activity. The enzymatic activity was K+-dependent (56%) and ouabain-sensitive (67%-inhibition). The electron-dense reaction product (SrPO4) of the cytochemical reaction (Ernst, 1972b) was localized along the inner surfaces of the basolateral membranes of the secretory cells. It was absent from mitochondria nuclei, vesicles, and other organelles. The luminal surface of the secretory cells was slightly reactive. On the basis of (1) this pattern of localization for the sodium transport system, (2) the presence of extensive intercellular labyrinthine channels (Bulger, 1963) that would facilitate "standing gradients" (Diamond and Bossert, 1968), and (3) the specific distribution of the energy-providing mitochondria, we conclude that the concentration and electrochemical gradients recorded from the secreting gland (Hayslett et al., 1974) are maintained across the domains of the basolateral surfaces of the secretory cells. 相似文献
10.
Dendritic cells (DCs) produce cytokines and are susceptible to cytokine-mediated activation. Thus, interaction of resting immature DCs with TLR ligands, for example nucleic acids, or with microbes leads to a cascade of pro-inflammatory cytokines and skewing of T cell responses. Conversely, several cytokines are able to trigger DC activation (maturation) via autocrine, for example TNF and plasmacytoid DCs, and paracrine, for example type I IFN and myeloid DCs, pathways. By controlling DC activation, cytokines regulate immune homeostasis and the balance between tolerance and immunity. The increased production and/or bioavailability of cytokines and associated alterations in DC homeostasis have been implicated in various human inflammatory and autoimmune diseases. Targeting these cytokines with biological agents as already is the case with TNF and IL-1 represents a success of immunology and the coming years will expand the range of cytokines as therapeutic targets in autoinflammatory and autoimmune pathology. 相似文献