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961.
I Hovestadt M Ernst H M?nig H Fischer 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1983,44(6):563-573
The metabolic burst accompanying phagocytosis of granulocytes (PMN) leads to the generation of activated oxygen species such as O-2, H2O2, 1O2 and OH; which give rise to chemiluminescence (CL) in the presence of luminol. Reliable CL-measurements of stimulated PMN can be carried out in freshly drawn mouse blood, when photon counts are related to the number of PMN. Effects of low dose total body X-irradiation were studied using C57B1/6 mice. It was found that 24 and 48 hours after irradiation (0.24-0.95 Gy) CL of whole blood was slightly decreased. If however CL-counts were related to the number of PMN, an enhanced CL per single granulocyte was recorded. The administration of cystamine leads to an immune stimulating effect of unirradiated animals. In animals, who received 0.95 Gy a distinct radioprotective effect of cystamine can be observed. 相似文献
962.
Te-ning E. Liu Beverly Wolf John Geigert Saul L. Neidleman Janice D. Chin David S. Hirano 《Carbohydrate research》1983,113(1):151-157
The production of solid d-arabino-hexos-2-ulose (d-glucosone) from d-glucose by use of an enzyme, pyranose-2-oxidase (EC 1.1.3.10), is described. The enzyme is extracted from the mycelia of Polyporus obtusus, partially purified, and then immobilized on activated CH-Sepharose 4B. The enzymic conversion of d-glucose into d-glucosone is simple and convenient, and provides a product free from residual d-glucose. Lyophilization of the filtered reaction-solution yields the product, solid d-glucosone. Assay methods have been developed for monitoring the enzymic reaction and evaluating the purity of the final product. 相似文献
963.
964.
Thomas T. Stevenson Richard H. Furneaux David Pang Fred Shafizadeh Lyle H. Jensen Ronald E. Stenkamp 《Carbohydrate research》1983,112(2):179-187
A single-crystal, X-ray diffraction study was performed on a nonalkenic, cyclic trimer (C18H18O9, 4) of levoglucosenone, in order to confirm its chemical structure. Crystals of 4 are orthorhombic, with unit-cell parameters of a = 792.20, b = 1874.35, c = 2383.02 pm, space group P212121, and z = 8. The structure was solved by direct methods, and refined by least-squares to R = 0.032, based on 2990 unique reflections. Each asymmetrical unit contains two symmetry-independent molecules of 4 and one of acetone. The previously assigned chemical structure and stereochemistry of 4 were found to be correct. 相似文献
965.
Distribution of Vibrio vulnificus and Other Lactose-Fermenting Vibrios in the Marine Environment 总被引:33,自引:23,他引:10
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During the summer of 1981, 3,887 sucrose-negative vibrios were isolated from seawater, sediment, plankton, and animal samples taken from 80 sites from Miami, Fla., to Portland, Maine. Of these, 4.2% were able to ferment lactose. The lactose-positive strains isolated from the various samples correlated positively with pH and turbidity of the water, vibrios in the sediment and oysters, and total bacterial counts in oysters. Negative correlations were obtained for water salinity. Numerical taxonomy was performed on 95 of the lactose-fermenting environmental isolates and 23 reference strains. Five clusters resulted, with the major cluster containing 33 of the environmental isolates and all of the Vibrio vulnificus reference strains. The 33 isolates, which produced an acid reaction in lactose broth within hours of initial inoculation, represented 20% of all lactose-fermenting vibrios studied. These isolates were nearly identical phenotypically to clinical strains of V. vulnificus studied by the Centers for Disease Control, Atlanta, Ga., and by our laboratory, and their identification was confirmed by DNA-DNA hybridization studies. V. vulnificus was isolated from all sample types and from Miami to Cape Cod, Mass., and comparison of the environmental parameters of the eight subsites yielding this species with those of all 80 subsites revealed no significant differences. The majority of the isolates were obtained from animals, with clams providing most (84%) of these. On injection into mice, 82% of the V. vulnificus isolates resulted in death. Members of the remaining four clusters contained strains which differed from V. vulnificus in such phenotypic traits as luminescence and in urease or H2S production. None of the other reference cultures, including nine other Vibrio species, were contained in the remaining clusters, and these isolates could not be identified. Most of these were also lethal for mice. Phenotypic differences, potential pathogenicity, and geographic distribution of the five clusters were examined. It is concluded that V. vulnificus is a ubiquitous organism, both geographically and in a variety of environmental sources, although it occurs in relatively low numbers. The public health significance of this organism and of the other unidentified lactose-fermenting Vibrio species is discussed. 相似文献
966.
Light and Electron Microscopic Studies of Microorganisms Growing in Rotating Biological Contactor Biofilms 总被引:5,自引:4,他引:1
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The biofilms growing in the first compartments of two rotating biological contactors used to treat municipal wastewater were examined by light and electron microscopy. The biofilms were found to contain a complex and varied microbial community that included filamentous and unicellular bacteria, protozoa, metazoa, and (possibly) bacteriophage. The predominant microorganism among these appeared to be a filamentous bacterium that was identical to Sphaerotilus in both morphological and ultrastructural characteristics. It was possible to isolate a Sphaerotilus-like bacterium from each contactor. Both the Sphaerotilus filaments and the wide variety of unicellular bacteria present tended to contain poly-β-hydroxybutyrate inclusions, a probable indication that these organisms were removing carbon from the wastewater and storing it. The microbial population of the biofilms appeared to be metabolically active, as evidenced by the presence of microcolonies and dividing cells. 相似文献
967.
David S. Carlson 《American journal of physical anthropology》1983,60(3):401-410
The growth of the masseter muscle in eight infant, juvenile, and adolescent female rhesus monkeys (M. mulatta) was examined over a 2.5 year period using serial radiographic cephalometric techniques with the aid of radiopaque muscle markers. The radiopaque markers, which are composed of small pieces of root canal broach inserted into the muscle belly, make it possible to determine longitudinal masseter muscle growth as well as migration of the masseter muscle relative to the mandible. It was found that the masseter muscle increased in length by 64% during the total growth period, most of which occurred between 6 and 18 months of age. Relative to the cranium, the masseter muscle grew markedly inferiorly and only slightly posteriorly. Relative to the mandible, the masseter migrated in a posterior and slightly superior direction, keeping pace with the ramus and condyle as they grew posteriorly and posterosuperiorly throughout the study period. It was concluded that: 1) radiopaque muscle markers are a valuable tool for analysis of muscle growth and alteration of muscle location; 2) the masseter muscle in the rhesus monkey undergoes elongation, probably due to addition of sarcomeres at the fiber-tendon junctions; and 3) posterior migration of the masseter muscle relative to the corpus of the mandible, probably due to the nature of its periosteal attachment, results in a stability of the anteroposterior position of the masseter muscle despite the anterior displacement of the mandible. 相似文献
968.
969.
Transformation of Clostridium acetobutylicum Protoplasts with Bacteriophage DNA 总被引:6,自引:3,他引:3
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Sharon J. Reid Errol R. Allcock David T. Jones David R. Woods 《Applied microbiology》1983,45(1):305-307
Techniques for the transformation of Clostridium acetobutylicum protoplasts with bacteriophage DNA are described. Transformation required regeneration of protoplasts and a 2-h eclipse period. 相似文献
970.
The nucleotide sequence of the embryonic chicken beta-type globin genes 总被引:11,自引:0,他引:11
J B Dodgson S J Stadt O R Choi M Dolan H D Fischer J D Engel 《The Journal of biological chemistry》1983,258(20):12685-12692