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  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 271 (1978), S. 370-372 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Chinese hamster ovary cells (CHO) were grown in suspension culture according to standard procedures5. Growth medium containing the drugs to be tested was de-oxygenated in a stirred' glass vessel by flowing purified nitrogen over the solution for 10-15 min before the addition of hypoxic cells ...
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-0603
    Keywords: mammalian cells ; radiation ; cell survival ; low dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To study the effects of low dose ionizing radiation on cells, we developed the automated low dose assay systems which is a semiautomatic computer aided system that permits efficient examination of individual cells. Specifically, it provides for systematic and reliable location of cell positions and it features the means to return to those positions in order to classify cell growth. The system allows for microscopic scanning of a 7 × 12 cm surface in 12.5-µm steps with a repeatability of 100 µm.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 16 (1995), S. 178-187 
    ISSN: 0197-8462
    Keywords: fibroblasts ; image cytometry ; cell migration ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Automated image cytometry techniques were used to measure motility and morphology in 3T3 fibro-blasts exposed to extremely-low-frequency (ELF) magnetic fields. Cell motility and morphology were measured as a function of time before, during, and after 3-4 hour exposures to vertically oriented, 100 μTRMS sinusoidal magnetic fields at various frequencies in the 10-63 Hz range. Sham exposures were also carried out. No static DC fields were applied, but the geomagnetic field was almost vertical and, therefore, had a large component (28.3 μT) parallel to the applied AC field. The morphology and motile behavior of the cells were characterized by mathematically defined descriptors, which were calculated and averaged for the exposure period as well as for control periods that preceded and followed the exposure period. Each experiment involved the tracking of 100 cells that were subjected to one of the test frequencies (unless a sham exposure was being conducted). Statistical analysis of the results showed that even small changes of 10-20% could be significant at the P 〈.05 level. Changes on this order were measured in a significant proportion of the experiments. However, because such results were seen for both the sham-exposed and the ELF-exposed cells, and because the range of values that was obtained for the sham exposures was the same as that obtained for the ELF exposures, we concluded that there was no evidence to show that any of the measured changes were attributable to the applied ELF magnetic field. © 1995 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 53 (1993), S. 254-255 
    ISSN: 0730-2312
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: One of the most critical issues regarding management of early breast cancer is the proper detection and correct estimation of its malignant potential. In recent years, primarily through mammography, the frequency of ductal carcinoma in situ (DCIS) in malignant breast biopsies has increased several fold, from ∼5% to over 20%. At present, DCIS classification is based exclusively on descriptive parameters and several attempts have been made to obtain uniform classification among pathologists. This goal has been elusive and further attempts both in North America and Europe have been made to better distinguish between DCIS lesions. However, even if this can be achieved to a satisfactory degree, the malignant potential of a DCIS lesion, either comedo or non-comedo, cannot be assessed without quantitative evaluation of these lesions. It may be possible to assess the malignant potential by estimating a variety of parameters, such as the presence of oncogenes or their products, presence of receptors, etc. To date, some of these have been shown either to be necessary or sufficient conditions for obtaining invasive cancer.We have recently shown that the nuclear features of diagnostic cells, as well as nuclear features of the surrounding normal appearing cells, can be used for objective lesion classification and estimation of the malignant potential of DCIS lesions. A high resolution image cytometer (Cyto-SavantTM, Xillix Technologies Corp.) has been developed. This device can be used for automated measurements of large numbers of cell nuclei stained stoichiometrically for DNA. Nuclear features such as size, shape, DNA amount, and foremost, the texture features describing the distribution of the DNA are extracted. The Cyto-SavantTM system has been trained to recognize the relevant cells in smears from fine needle aspirates or cytospins of cells extracted from tissue blocks using standard procedures. Several thousand cell nuclei per slide can be analyzed using only a few minutes of the pathologist's time. Combining qualitative assessment with quantitative data greatly improves the diagnosis of DCIS lesions and may provide prognostic and treatment monitoring information as well. The system will be discussed in detail and experimental data shown for several cases.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 53 (1993), S. 107-113 
    ISSN: 0730-2312
    Keywords: Early breast cancer ; image cytometry ; malignant potential ; nuclear features ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have been testing two independent hypotheses which postulate that the malignant potential of early breast cancer can be objectively assessed by measuring nuclear features of the diagnostic-malignant cells (hypothesis I) and/or normal-appearing epithelial cells found in the vicinity of the carcinoma (hypothesis II). In preliminary experiments, we tested some of these hypotheses using historical samples and a high resolution image cytometry apparatus. Tissue sections were stained with our stoichiometric stain and over 60 nuclear features, primarily texture features describing the DNA distribution in the nuclei, were employed in the multivariate analyses. Data derived from measurements of ductal carcinoma in situ (DCIS) with and without the invasive component indicated that the malignant potential of these lesions can be estimated with a sensitivity and specificity of at least 80%. The analysis of the tissue surrounding an invasive breast carcinoma showed that the existing malignancy can be predicted solely from the measurements of normal nuclei (normal-appearing breast lobules) in more than 85% of patients. This result indicates that the analysis of benign tissues also could give prognostically valid information.These results can be greatly improved using larger sample sizes and other improvements, including technical improvements of the cytometry device. We believe that this approach can be developed into a practical diagnostic and prognostic tool for better management of early breast cancer.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 59 (1995), S. 43-54 
    ISSN: 0730-2312
    Keywords: Image cytometry ; malignant potential ; progression ; regression ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Of the approximately 60 million Pap smears performed in the United States in 1995, about 8% or 5 million will show cytology that is “not negative” (ASCUS, AGCUS, LSIL, HSIL, etc.). Possibly 15% or about 0.7 million of these cases will have positive follow-up by repeated Pap smears, colposcopy or biopsy. More than 4 million will be false-positive smears based on the reference standard of biopsy or repeated smears. If no treatment or medical intervention was offered to the 0.7 million cytologically and histologically positive cases, perhaps 20,000 (3%) would develop into invasive cancer. Of the original 5 million cytologically “not negative” cases, fewer than 0.5% have the potential to develop into invasive cancer.While considerable attention has been paid to false-negatives in Pap screening, the above considerations indicate that the cytological and histological criteria for assessing the malignant potential of “not negative” samples might benefit from some refinement. Until such refinement occurs, any chemoprevention studies in cervix face a formidable signal-to-noise problem - worse than 1:30.This paper presents data from quantitative image cytometry of cervical smears for assessing the malignant potential of various “not negative” cases. We have approached this in two ways - by analyzing dysplastic cell nuclei and by analyzing the nuclei of cytologically normal cells growing in the vicinity of the neoplastic lesion. In both cases, nuclear features describing the distribution of the DNA in the cell nuclei (especially texture features) are the discriminating factors. Future research into the objective assessment of malignant potential of “not negative” cases is outlined.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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