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  • 1
    Electronic Resource
    Electronic Resource
    Inhibition and recovery of growth processes in roots of pisum sativum L. Exposed to 60-Hz electric fields (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 329-340 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60 Hz ; biologic effects ; membrane potentials ; recovery ; Pisum sativum ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Roots of Pisum sativum L. were chronically exposed in aqueous inorganic nutrient medium to 60-Hz electric fields between 140 and 490 V/m (growth medium conductivity ∼ 0.08 S/m). The growth rate, meristematic mitotic index, and growth rate recovery of the roots were determined. At 140 V/m there was no perturbation in growth rate or mitotic index. At 430 V/m the growth rate and the mitotic index were reduced. The mitotic index had a maximum depression (∼ 55% of control), which occurred at 4 h. The depression in growth rate was immediate and constant over time. When roots were exposed to an electric field at 430 V/m for 2 days, the growth rate was depressed by about 40%. When the field was terminated, the growth rate steadily increased and was almost normal after 5 days. At 490 V/m root growth rate was almost completely arrested. According to these results, there is a narrow range of induced membrane potentials that span the range from slightly altered to almost completely arrested growth rates.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020405
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  • 2
    Electronic Resource
    Electronic Resource
    Behavioral detection of 60-Hz electric fields by rats (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 4 (1983), S. 215-247 
    Details
    ISSN: 0197-8462
    Keywords: electric field ; 60-Hz ; detection ; psychophysics ; rats ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Rats partially deprived of food were trained individually to press a lever in the presence of a vertical, 60-Hz electric field and not to press in its absence. Correct detections that occurred during brief, 3- or 4-s trials occasionally produced a food pellet. The probability of detecting the field was found to increase as field strength increased. The threshold of detection, ie, the field strength required for detections at a probability of 0.5 after correction for errors, was generally between 4 and 10 kV/m. The range of field strengths between almost zero and almost 100% correctness of detection was approximately 8 kV/m. A logistic function provided a good description of the increase in the detection probability with increasing field strength. These performances occurred reliably in 19 rats, some of which were studied for 2 years. Control procedures showed that the behavior required that the rat be in the electric field; the behavior was not controlled by any of several potentially confounding variables.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250040304
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  • 3
    Electronic Resource
    Electronic Resource
    Growth rate and mitotic index analysis of Vicia faba L. Roots exposed to 60-Hz electric fields (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 6 (1985), S. 293-303 
    Details
    ISSN: 0197-8462
    Keywords: plant roots ; 60-Hz electric fields ; mitotic index ; Vicia faba L ; growth rate ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Growth, mitotic index, and growth rate recovery were determined for Vicia faba L. roots exposed to 60-Hz electric fields of 200, 290, and 360 V/m in an aqueous inorganic nutrient medium (conductivity 0.07-0.09 S/m). Root growth rate decreased in proportion to the increasing strength; the electric field threshold for a growth rate effect was about 230 V/m. The induced transmembrane potential at the threshold exposure was about 4-7 mV. The mitotic index was not affected by an electric field exposure sufficient to reduce root growth rate to about 35% of control. Root growth rate recovery from 31-96% of control occurred in 4 days after cessation of the 360 V/m exposure. The results support the postulate that the site of action of the applied electric fields is the cell membrane.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250060309
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of 60-Hz electric fields on cellular elongation and radial expansion growth in cucurbit roots (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 8 (1987), S. 57-72 
    Details
    ISSN: 0197-8462
    Keywords: root cell growth ; Cucumis sativus roots ; Cucurbita maxima roots ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Serial longitudinal and transverse sections were prepared from roots of Cucumis sativus and Cucurbita maxima that had been exposed/sham-exposed to 60-Hz electric fields for 0-2 days. Field exposures were selected to produce a 10-20% or a 70-80% growth inhibition in whole roots of both species. Cortical cell length and diameter were measured using a microscope and eyepiece micrometer; measurements were conducted “blind”. In both species, inhibition of cellular elongation was associated with exposure to electric fields (EF). Cellular radial expansion was apparently unaffected by exposure to electric fields. The diameters of radially unexpanded or fully expanded C. sativus cortical cells were about 25-30% smaller than those of comparable cells in C. maxima roots. Previous studies of the relationship between rates of root growth and applied EF strength showed that the response thresholds of C. sativus and C. maxima differed by a similar relative amount. These results are consistent with the postulate that EF-induced effects in roots are elicited by induced transmembrane potentials.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250080108
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  • 5
    Electronic Resource
    Electronic Resource
    Exposure to combined static and 60 Hz magnetic fields: Failure to replicate a reported behavioral effect (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 17 (1996), S. 279-292 
    Details
    ISSN: 0197-8462
    Keywords: low flux-density magnetic fields ; cyclotron resonance ; operant conditioning ; multiple schedules ; rats ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Two experiments failed to confirm the Thomas, Schrot, and Liboff report that low-intensity magnetic fields disrupted the operant behavior of rats. In their experiment, food-deprived rats were trained to press a lever to obtain food pellets under a multiple fixed-ratio (FR) 30, differential reinforcement of low rate 18-24 s (DRL 18-24) schedule. After baseline training, the rats were exposed to a 30 min treatment in a different chamber prior to behavioral testing. When the treatment consisted of a horizontal 60 Hz magnetic field at 5 x 10-5 Telsa aligned along the north-south axis combined with a static field that reduced the background to 2.61 x 10-5 Telsa, the rate of lever pressing in the DRL component of the multiple schedule increased reliably during the immediately following test session. Changes in responding were not observed when the rats were exposed to either the static field or the 60 Hz field independently nor during sham exposures to the fields. In the present experiments, only the combined fields, i.e., those reported to be effective, were studied in rats using the same general behavioral and exposure protocol used by Thomas et al [1986a]. In experiment 1, the 2.61 x 10-5 Telsa was achieved by reducing the vertical component of the static field. In experiment 2, both the horizontal and the vertical components were altered to match those used by Thomas et al. In both experiments additional magnetic field conditions were also studied to ensure that threshold values were exceeded and, in experiment 2, to address concerns about the role of harmonic frequencies of the 60 Hz field. The baseline performances approximated those of Thomas et al. Performances were compared between exposure, sham-exposure and control sessions. None of the exposure conditions altered any of the behavioral measures. The reasons for failing to replicate the results of Thomas et al. remain unknown. © 1996 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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  • 6
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    Binding of Tissue-Plasminogen Activator to Fibrin: Effect of Ultrasound (1998)
    American Society of Hematology
    Details
    Publication Date: 1998-03-15
    Description: Ultrasound reversibly alters the structure of polymerized fibrin, an effect that could influence tissue-plasminogen activator (t-PA) binding. We have, therefore, characterized the effects of ultrasound on binding of t-PA to fibrin using a novel system in which radiolabeled, active-site blocked, single chain tissue-plasminogen activator flowed through a fibrin gel at constant rate, and specific binding was determined by monitoring incorporation of radiolabel. Results using polymerized fibrin were compared with those using a surface of fibrin immobilized on Sepharose beads in a similar system. Interaction of t-PA with surface-immobilized fibrin involved two classes of binding sites (Kd = 31 nmol/L and 244 nmol/L) and a maximum binding ratio of 3.8 mol t-PA/mol fibrin. Ultrasound increased Kd for the high affinity site to 46 nmol/L (P 
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Published by American Society of Hematology
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  • 7
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    International Scoring System for Evaluating Prognosis in Myelodysplastic Syndromes (1997)
    American Society of Hematology
    Details
    Publication Date: 1997-03-15
    Description: Despite multiple disparate prognostic risk analysis systems for evaluating clinical outcome for patients with myelodysplastic syndrome (MDS), imprecision persists with such analyses. To attempt to improve on these systems, an International MDS Risk Analysis Workshop combined cytogenetic, morphological, and clinical data from seven large previously reported risk-based studies that had generated prognostic systems. A global analysis was performed on these patients, and critical prognostic variables were re-evaluated to generate a consensus prognostic system, particularly using a more refined bone marrow (BM) cytogenetic classification. Univariate analysis indicated that the major variables having an impact on disease outcome for evolution to acute myeloid leukemia were cytogenetic abnormalities, percentage of BM myeloblasts, and number of cytopenias; for survival, in addition to the above, variables also included age and gender. Cytogenetic subgroups of outcome were as follows: “good” outcomes were normal, −Y alone, del(5q) alone, del(20q) alone; “poor” outcomes were complex (ie, ≥3 abnormalities) or chromosome 7 anomalies; and “intermediate” outcomes were other abnormalities. Multivariate analysis combined these cytogenetic subgroups with percentage of BM blasts and number of cytopenias to generate a prognostic model. Weighting these variables by their statistical power separated patients into distinctive subgroups of risk for 25% of patients to undergo evolution to acute myeloid leukemia, with: low (31% of patients), 9.4 years; intermediate-1 (INT-1; 39%), 3.3 years; INT-2 (22%), 1.1 years; and high (8%), 0.2 year. These features also separated patients into similar distinctive risk groups for median survival: low, 5.7 years; INT-1, 3.5 years; INT-2, 1.2 years; and high, 0.4 year. Stratification for age further improved analysis of survival. Compared with prior risk-based classifications, this International Prognostic Scoring System provides an improved method for evaluating prognosis in MDS. This classification system should prove useful for more precise design and analysis of therapeutic trials in this disease.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Published by American Society of Hematology
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  • 8
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    Binding of Tissue-Plasminogen Activator to Fibrin: Effect of Ultrasound (1998)
    American Society of Hematology
    Details
    Publication Date: 1998-03-15
    Description: Ultrasound reversibly alters the structure of polymerized fibrin, an effect that could influence tissue-plasminogen activator (t-PA) binding. We have, therefore, characterized the effects of ultrasound on binding of t-PA to fibrin using a novel system in which radiolabeled, active-site blocked, single chain tissue-plasminogen activator flowed through a fibrin gel at constant rate, and specific binding was determined by monitoring incorporation of radiolabel. Results using polymerized fibrin were compared with those using a surface of fibrin immobilized on Sepharose beads in a similar system. Interaction of t-PA with surface-immobilized fibrin involved two classes of binding sites (Kd = 31 nmol/L and 244 nmol/L) and a maximum binding ratio of 3.8 mol t-PA/mol fibrin. Ultrasound increased Kd for the high affinity site to 46 nmol/L (P 
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Published by American Society of Hematology
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  • 9
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    Large Field Virtual Microscopy as a Tool for Quality Control and Blast Definitions in MDS and Leukemia. From the International Working Group on MDS. (2006)
    American Society of Hematology
    Details
    Publication Date: 2006-11-16
    Description: All current classifications for myelodysplastic syndromes (MDS) require the identification of the blast population. From the FAB (1976) to the WHO (1999) new criteria such as the results of cytogenetic analysis have been introduced but the percentage of blasts remains a major factor in diagnosis, subclassification and prognosis. The definition of a blast cell is still based on those proposed in 1976 by the FAB group, but it is unclear that it has been applied in the same manner worldwide. Since the WHO has changed the definition for AML (minimum criterion is 20% blasts) and since RAEB has been divided into two groups (5 to 9 and 10 to 19% blasts respectively) it has become clear that the definition of blasts of granulocyte lineage should be more precise. Definition: Experts in morphology from the IWG on MDS have proposed that all cells from undifferentiated blast (without granules) to but not including the promyelocyte would qualify as “blasts”. A promyelocyte starts with the appearance of a “clearly visible Golgi zone” independently of the number of granules. Mature granulocyte starts with disappearance of cytoplasmic basophilia and more mature nucleus. Methodology: To verify agreement between experts on this new definition, a unique digital picture was produced from the bone marrow smear of an AML patient with FAB M2 by the association of 150 consecutive native pictures (600x800 pixels). The mosaic picture is 8340x2386 pixels (about 30 M in jpeg format or 16 M in pdf). All the 265 nucleated cells have been numbered and a drop down menu for choices was included. The picture was placed on the server of the MDS Foundation (http://www.mds-foundation.org/goasguenfollowup) and after evaluation the results were automatically sent to the MDS foundation center and registered. The five experts evaluated exactly the same cells (numbered from 1 to 265) and results were submitted for statistical analysis. Results: for 176 cells (66.6%) there was complete concordance (5/5) and for 60 others (22.7%) concordance was 4/5. If we consider that concordance of at least 4/5 is acceptable, we obtained 89.4% good concordance. Moreover, 23 cells (8.7%) had a concordance of 3/5 while only 5 (1.89%) had a concordance of 2/5. We conclude that these definitions of blasts and promyelocytes are reproducible and may help to standardize the classification of AML and MDS. All experts would have produced the same diagnosis since standard deviations of the percentages of various cell types were very low. Conclusion: the production of large field digital pictures may be very useful for education and quality control in morphology. In addition, use of such images may help to provide a new approach to difficult cells and may be useful in proposing new criteria for classification. Table: Minimum, maximum and mean percentage of cells for 5 experts % of cells Minimum Maximum Mean Standard deviation Blasts 58.1 61.7 59.9 1.54 Promyelocytes 12.2 22.3 17.7 4.82 Matures cells 14.4 21.6 18.8 3.12
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Published by American Society of Hematology
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