Biomedical subjects

G Cewrien

Publications and source records attributed to G Cewrien.

3 recordsLinked to original sources

PubMed1986

Quantitation of the nuclear DNA content in tissue prepared for electron microscopy.

The possibility of determining the cellular DNA content in tissue prepared for electron microscopy (EM) was investigated. Comparative cell population DNA analyses of deparaffinized and Epon-embedded sections of equal thickness (2 micron) from the same tumor (osteosarcoma) showed almost identical DNA distribution curves. The methodologic prerequisites for both EM and DNA analyses of identical cells was then investigated. Using a special technique involving consecutive sections of 500-600 A and 2-micron thickness for EM morphology and Feulgen staining, respectively, nuclear parts of identical cells could be identified in both types of sections. Thus, cells selected in ultrathin sections could be identified in corresponding Feulgen-stained Epon-embedded sections for cytophotometric DNA analysis. All normal cells (lymphocytes, fibroblasts, macrophages), as defined and selected at the ultrastructural level, proved to be diploid (with normal DNA content) as determined in the corresponding Feulgen-stained Epon-embedded sections, whereas all analyzed osteosarcoma cells, except one, were aneuploid. The results indicate that 2-micron thick Feulgen-stained, Epon-embedded specimens from osteosarcoma, previously fixed in glutaraldehyde and OsO4, may be used for cytophotometric DNA measurements. Since aneuploidy is almost exclusively found in malignant cells, this criterion may serve as a marker for such cells. Consequently, whenever it is questionable whether in a mixed population a given cell selected for ultrastructural study is malignant or not, DNA cytophotometry may give decisive information, provided aneuploidy can be demonstrated.

Bone Neoplasms↗

PubMed1982

Cellular DNA content in human osteosarcoma: aspects on diagnosis and prognosis.

The cellular DNA content was determined in a consecutive series of 26 classical and two paraosteal osteosarcomas by means of single cell cytophotometry. All classical osteosarcomas regardless of histologic type (osteo-, chondro-, fibroblastic) or grade were found to be hyperploid (abnormally increased DNA content) while both paraosteal osteosarcomas proved to be diploid (normal DNA content). Closer analysis of the DNA distribution curves showed that the majority of the classical osteosarcomas exhibited a triploid modal DNA value and more than 90% hyperploid cells. Cytochemical characterization of osteosarcomas may be of prognostic significance in reflecting the degree of malignancy. The results of the present study indicate that cytophotometric DNA analysis, as an adjunct to conventional histologic evaluation, offers an objective means of differentiating between classical and paraosteal osteosarcomas.

Adolescent↗

PubMed1981

Comparative single-cell and flow DNA analysis of bone sarcoma.

Five chondrosarcomas and seven osteosarcomas were analyzed by single-cell DNA cytophotometry, in both imprint preparations and tissue sections, and by means of flow DNA cytophotometry. A comparative analysis of the DNA distribution curves of each tumor, as determined by these three methods, showed a good correlation with respect to the modal DNA values. In addition, there was a strong correlation between the proportion of tumor cells with an increased DNA value (hyperploid cells) in imprint preparations and in tissue sections of each tumor as determined by single-cell DNA cytophotometry. Flow cytophotometry appears to be the method of choice for the determination of the aneuploid modal DNA value of a tumor cell population, while single-cell cytophotometry of identified cells seems more appropriate for the determination of the proportion of hyperploid cells in a tumor cell population. In this respect, single-cell and flow DNA cytophotometry may be considered complementary. For the demonstration of the existence of aneuploidy in a tumor cell population, however, the three investigated methods seem to be equivalent. Previous studies using single-cell cytophotometry have shown that DNA determinations in chondrosarcoma as well as in other tumors provide significant prognostic information. For routine clinical work, however, as an adjunct to the conventional histopathologic malignancy grading, single-cell cytophotometry is a rather time consuming procedure, while flow cytophotometry offers a rapid and convenient means of determining the nuclear DNA content. The present study clearly showed that flow DNA cytophotometry may be applied to sarcoma of bone.

Bone Neoplasms↗