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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 4 (1983), S. 371-381 
    ISSN: 0197-8462
    Keywords: 2,450 MHz ; microwaves ; natural killer cells ; macrophages ; mice ; lymphocytes ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effect of 2,450-MHz CW microwaves on natural killer (NK) cell activity and lymphocyte responsiveness to mitogen stimulation was studied in mice. Groups of mice were irradiated at power densities of 5, 15, or 30 mW/cm2 (SAR = 3.5, 10.5, and 21 W/kg respectively) for 1.5 h on 2 or 9 consecutive days. NK cell activity was determined using an in vitro 51Cr release cytotoxicity assay and an in vivo tumor-cell clearance assay. No consistent change was observed in the mitogen response of spleen cells from sham compared with irradiated mice. A significant suppression of NK cell activity measured in vitro was observed for mice irradiated at 30 mW/cm2, but not at 15 or 5 mW/cm2. A significant suppression of NK cell activity, as determined using the in vivo tumor clearance assay, was also observed at 30 mW/cm2. NK cell activity, as determined using the in vitro assay, returned to normal within 24 h following the last irradiation. Treatment of mice with hydrocortisone caused suppression of NK cell activity measured in vitro and in vivo. Paradoxically, peritoneal macrophage phagocytosis was enhanced following irradiation at 30 mW/cm2, the power density at which NK activity was suppressed. The possible role that microwave heating plays in producing these effects is discussed.
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 542-551 
    ISSN: 0192-253X
    Keywords: Glycine max ; Transposable element ; Transposon tagging ; Genetic instability ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An unstable mutation for anthocyanin pigmentation in soybean (Giycine max [L.] Merr.) was identified in 1983. The mutability is conditioned by an allele at the w4 locus that is recessive to wild type. The population containing the mutable allele is known as the w4-mutable line. Most plants in the line have chimeric flowers with purple sectors on a near-white background. The mutable allele yields germinal revertants at a rate that varies from 5 to 10% per generation, and the revertant alleles are stable. Approximately 1% of the progenies derived from germinal revertant plants contain mutations at other loci These features, as well as the occurrence of pale flower phenotypes and changes of state, suggest that a transposable element system is producing the unstable phenotype.Several new mutants were isolated in an experiment designed to tag loci. The first three chlorophyll-deficient mutants found (CD-1, CD-2, and CD-3) are inherited as single-gene recessives. Each of the mutants lacks the same two mitochondrial malate dehydrogenase (MDH) bands. No recombination has been detected between the MDH phenotype and the chlorophyll-deficient phenotype. Genetic data indicate that the three mutants are allelic, and additional evidence suggests that each of the CD mutants is the result of a deletion. In the CD-1, CD-2, and CD-3 mutants, the deletions result in the silencing of an MDH locus, atypical chloroplast development, and an altered chlorophyll composition. Additional mutants for root necrosis, partial and near sterility, chlorophyll deficiency, and flower color isolated from the transposon tagging study have provided material for future research.
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  • 3
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Experiments will be described which demonstrate that the product of purified “Qβ-replicase” is fully competent to serve both as a template and as a program for the synthesis of complete virus particles. The use of mutant RNA has permitted the demonstration that nucleic acid is the instructive agent in the replication process and hence satisfies the definition of a self-duplicating entity. Methods have been devised to examine the product both physically and biologically with a minimum of manipulation and with complete recovery of product and input template. A detailed analysis of every interval of synthesis has thus become possible. These technical advances have permitted us to demonstrate the existence of a latent period prior to the appearance of the first new complete infectious RNA molecules. Further, this latent period is accompanied by an eclipse of the input templates as infectious agents. The use of electrophoretic separation on acrylamide gels has yielded a detailed account of both templates and early product during the latent period, with the consequent identification of the intermediate stages. The resulting data and their implications for the mechanism of RNA replication will be discussed.
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  • 4
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this study, the intracellular concentrations of six elements (mmole/kg dry weight) were directly measured in the muscle fibers of pectoralis major muscles of eight week old, genetically dystrophic and normal chickens by the X-ray microanalysis technique. The extent of muscle degeneration was evaluated by morphometric measurements of muscle fiber diameter and other histological changes. A significant increase in the concentration of intracellular sodium and chlorine was evident in dystrophic muscles. The concentration of intracellular sodium was 127.0 ± 35.0 in the muscle fibers of dystrophic chicks compared to 65.7 ± 16.5 in normal controls. The concentration of chlorine was 90.5 ± 27.5 and 54.1 ± 5.5 in the muscle fibers of dystrophic and normal chicks respectively. The intracellular concentrations of potassium, magnesium, phosphorous, and sulfur remained unchanged in the dystrophic condition. Morphometric studies revealed that the dystrophic pectoralis muscles contain fewer but thicker fibers per unit area compared to normal pectoralis muscles. The importance of these findings are discussed in relation to the results of earlier investigations.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 9 (1984), S. 253-260 
    ISSN: 0148-7280
    Keywords: calmodulin ; embryonic development ; mitosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Two-cell mouse embryos were incubated in the presence of calmodulin inhibitors to determine their effect on embryonic development to the blastocyst stage. Calmodulin, a Ca2+-dependent regulatory protein, has been localized in the cytoplasm and has been implicated in regulation of many cellular events, such as mitosis. Several concentrations of either commercial or synthesized calmodulin inhibitors were tested. Several phenothiazine sulfoxide derivatives were more effective than the three naphthalene sulonic acid derivatives tested; 2-chloro-10-aminopropyl phenothiazine and 10-aminopropyl phenothiazine were the most potent phenothiazines to inhibit embryonic development at the two-cell stage. The interesting aspect of this study is that phenothiazine sulfoxide derivatives are not potent inhibitors of calmodulin, however, they were successful in inhibiting embryonic development. Potent inhibitors of calmodulin apparently did not penetrate the embryonic membranes because they had no effect.
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  • 6
    ISSN: 0148-7280
    Keywords: heparin ; fertilization ; dextran sulfate ; fucose sulfate glycoconjugate ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effects of sulfated glycoconjugates on the preparation of mammalian sperm for fertilization were investigated. The three sulfated glycoconjugates tested were heparin, dextran sulfate, and the fucose sulfate glycoconjugate (FSG) from the sea urchin egg jelly coat. In vivo, FSG induces the acrosome reaction in sea urchin sperm. Bovine sperm were found to be capacitated by heparin and FSG as judged both by ability of lysophosphatidylcholine (LC) to induce an acrosome reaction and by ability to fertilize bovine oocytes in vitro. The mechanism by which heparin or FSG capacitated bovine sperm appeared similar, since glucose inhibited capacitation by both glycoconjugates. In contrast to effects on bovine sperm, heparin and FSG induced the acrosome reaction in capacitated hamster sperm. When hamster sperm were incubated under noncapacitating conditions, heparin had no effect on capacitation or the acrosome reaction. Three molecular weights (MW) of dextran sulfate (5,000, 8,000, 500,000) were found to capacitate bovine sperm as judged by the ability of LC to induce an acrosome reaction. Whereas bovine sperm incubated with 5,000 or 8,000 M W dextran sulfate fertilized more bovine oocytes than control sperm (P 〈0.05), sperm treated with 500,000 M W dextran sulfate failed to penetrate oocytes. The high-MW dextran sulfate appeared to interact with the zona pellucida and/or sperm to prevent sperm binding. Results suggest that sulfated glycoconjugates may prepare sperm for fertilization across a wide range of species.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 21 (1988), S. 233-241 
    ISSN: 0148-7280
    Keywords: spermatozoa ; acrosome ; F79.3E2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Transmission electron microscopy was used to confirm that a monoclonal antibody (F79.3E2; class IgGlK) was specifically localized to an antigen in the acrosomal ground substance of stallion sperm. This antibody was used to develop and validate an indirect immunofluorescent procedure to evaluate integrity of the plasma-acrosomal membranes of stallion sperm. The concept was that primary monoclonal antibody would be “shielded” from its acrosomal antigen by an intact plasma membrane. Conversely, sperm with damaged plasma-acrosomal membranes would exhibit green acrosomal fluorescence when viewed with an epifluorescence microscope. A lipophilic counterstain (red fluorescence) was used to insure that all sperm were visualized. Sperm in fresh-extended or frozen-thawed semen were incubated with hybridoma supernatant containing monoclonal antibody for 30 min at 37°C, then a second antibody (rabbit anti-mouse IgG-FITC) was added for 30 min at 37°C. Unbound antibody was removed by dilution and centrifugation. Sperm were resuspended in phosphate-buffered saline containing Evan's blue as a counterstain. All sperm fluoresced bright red, regardless of the status of cell membranes, except that in cells with damaged plasma-acrosomal membranes, the green fluorescence associated with antibody was overriding for the rostral portion. By counting fluorescent and nonflourescent “acrosomes”, the percentage of sperm with intact plasma-acrosomal membranes was easily determined. Evaluation of five mixtures of undamaged and damaged sperm by this procedure gave a correlation of 0.91 between the percentage of damaged sperm in a mixture and the percentage of sperm with a fluorescent acrosome. Intra- and interassay coefficients of variability were 〈 6%.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 11 (1990), S. 273-282 
    ISSN: 0197-8462
    Keywords: electric field ; ion current ; ion concentration ; average daily gain ; reproduction ; cow ; calf ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Two herds of beef cattle were maintained beneath a ±500 kV direct-current transmission line during a 30-month period, and were compared with two similar herds maintained away from the transmission line. Exposures of animals under the line were five to 30 times greater than those of control animals, depending on the parameter of interest, with average exposure magnitudes of 5.6 kV/m, 4.1 nA/m2, and 13 k ions/cm3, respectively, for electric field, ion current, and density of ions. Productivity and health status of cows and calves were similar between lines and control treatments. Mean body mass of cows increased with maturity, from 438 kg in 1985 to 496 kg in 1987. Calf gain averaged 0.93 kg per head per day. No unusual sources of mortality were observed. Based on this confinement study, beef cattle permitted to graze in the vicinity of a high-voltage, direct-current transmission lines are not expected to experience any decrease in frequency of conception, calving, growth rate, or survival.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 279-284 
    ISSN: 0197-8462
    Keywords: 970 MHz ; rats ; long-term exposure ; serum chemistry ; hematology ; lymphocytes ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Rats (N = 16) exposed individually in circularly polarized waveguides to 970-MHz electromagnetic radiation (SAR=2.5 mW/g, 22 h daily for 70 consecutive days) had significantly higher serum levels of triglycerides, albumin, and total protein compared with sham-irradiated controls. No difference was observed in the weights, hematologic profile, or in vitro lymphocyte responses to mitogens between these two groups. The higher serum levels of triglycerides in radiofrequency-radiation-exposed rats suggest a non-specific stress reaction.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 4 (1983), S. 383-396 
    ISSN: 0197-8462
    Keywords: hematology ; immunology ; mice ; pulsed microwaves ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Mice were exposed in the far field in an anechoic chamber to 2,880-MHz pulsed microwaves 3 to 7.5 h daily, 5 days/week for 60 to 360 h. Three experiments were performed at average power densities of 5 mW/cm2 and six at 10 mW/cm2, corresponding to averaged specific absorption rates (SARs) of 2.25 and 4.50 mW/g, respectively. Each experiment consisted of eight mice, with a concurrently sham-exposed group of eight. In two of three studies at 5 mW/cm2, there was a significant increase in bone marrow cellularity in the microwave-exposed groups compared to the sham-exposed groups. Significant differences were occasionally seen in erythrocyte, leukocyte, and platelet values from microwaveexposed groups, but were not consistently observed. In one of six groups exposed at 10 mW/cm2, mean bone marrow cellularity was reduced significantly in the microwaveexposed mice; in another group, the lymphocyte count was increased. In only one exposure (10 mW/cm2 for 360 h) was any significant effect noted on serum proteins: a reduction to 5.1 ± 0.3 g/dl in the exposed versus 5.6 ± 0.4 g/dl in the sham-exposed mice. This was due to a decrease in alpha and beta globulins, with no effect on albumin or gamma globulin concentrations. No effect on bone marrow granulocyte/macrophage colony-forming units (CFU) was revealed following exposure of mice to pulsed microwaves at 5 mW/cm2. In one of four exposures at 10 mW/cm2, there was a significant increase in CFU-agar colonies. No significant effects of exposures at 10 mW/cm2 were observed on in vivo and in vitro assays of cell-mediated immune functions. No exposure-related histopathologic lesions were found from examination of several tissues and organs. Results of these series of exposures of mice at SARs of 2.25 and 4.50 mW/g indicated no consistent effects on the hematologic, immunologic, or histopathologic variables examined.
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