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Biomedical subjects

L M Cherry

Publications and source records attributed to L M Cherry.

29 records · Page 2Linked to original sources
PubMed1985

Differential mutagen susceptibility in cultured lymphocytes of normal individuals and cancer patients.

When cultured human lymphocytes were treated with a radiomimetic chemical bleomycin, metaphase chromosomes from different individuals exhibited a wide spectrum of responses in terms of number of chromatid lesions. This variability is interpreted as the result of capability for DNA repair. Among 100 healthy, normal individuals tested, nearly 60% showed a mean breaks per cell rate in the range of 0.20-0.60, whereas, only 12% showed breaks per cell rates above 1.00. On the other hand, among 75 cancer patients, 60% showed breaks per cell rates above 1.00. It is believed that differential responses to a mutagen have genetic implications. Individuals with DNA repair deficiencies may be more susceptible to carcinogens and, therefore, are more susceptible to neoplastic induction.

Bleomycin↗
PubMed1985

Fluorescence microscopy with antisera against specific cellular structure: double photography method for cell identification in populations of multiple cell types.

Immunofluorescent staining techniques using antitubulin antibody have been difficult to apply to meiotic tissue (testis) because of the large number of cell types present. Such techniques customarily use a fluorescent dye to counterstain nuclei, and this counterstain is hard to distinguish because of the fluorescence of the antitubulin. By counterstaining with dilute hematoxylin, we can photograph the same field using UV and then conventional illumination. This double photography allows us to identify precisely the many types of cells present, and it will be a useful tool for reexamining the staging of spermatogenesis.

Animals↗
PubMed1984

Antitubulin immunofluorescence studies of spermatogenesis in the mouse.

Immunofluorescence staining techniques, using antibodies against tubulin molecules, have been successfully used with somatic tissue culture cells. Their application to gametogenesis, however, has been more difficult, largely due to the presence of many different cell types in such a preparation. We have circumvented this problem by counterstaining with dilute hematoxylin, a biological stain that shows excellent cellular morphology without affecting the fluorescence of the antibody. We can then photograph the same field, using either ultraviolet light or conventional bright-field microscopy. Using this approach, we have examined the entire progression of murine spermatogenesis, from spermatogonial cells through mature spermatozoa. This technique has been especially valuable in the visualization of the manchette, and has allowed a reassessment of the staging of spermatid development. In the future, the antibody/hematoxylin double-staining approach will allow a more informative examination of the effects of tubulin-active mitotic poisons on mammalian germline cells.

Animals↗
PubMed1984

Effects of gamma-irradiation on chromosomes of cultured lymphocytes from rheumatoid arthritis patients and their family members.

Increased rates of spontaneous or induced chromosome breakage are seen in many types of diseases, including the 'collagen-type' autoimmune diseases. Using a 60Co gamma cell, we irradiated lymphocyte cultures from three related rheumatoid arthritis patients, their immediate family members, and two unrelated rheumatoid arthritis patients. Although these individuals had not shown abnormally high levels of spontaneous chromosome breakage, they did show an abnormal sensitivity to irradiation, which was manifested in several ways. Two of the probands showed induced breakage rates that were twice as high as those seen in controls. In addition, the reduction of mitotic index, due either to increased cell death or to induction of a G2 lag period, was higher in the arthritis group (including non-symptomatic family members) than in the control group. Finally, we observed a high frequency of an unusual type of cell in the arthritis group. These unusual cells resembled c-anaphases seen with extended colcemid treatment, and may indicate that the mitotic apparatus in cells from this group is particularly sensitive to ionizing radiation.

Arthritis, Rheumatoid↗
PubMed1982

Restitution of chromatid and isochromatid breaks induced in the G2 phase by actinomycin D.

Although actinomycin D (AMD) appears to cause chromatid breakage, it has been suggested that it merely weakens the chromosomal proteins, causing breaks to occur during the stress of fixation. To determine if this was true, we examined lymphocytes treated with AMD (3.5 micrograms/ml) for 90 min prior to harvesting for evidence of DNA repair. Besides single chromatid breaks, we observed a high frequency of chromatid exchange figures (translocations, inversions, rings) and closed isochromatid breaks, indicating that a type of DNA repair leading to chromosome aberration had occurred prior to cell fixation. Therefore, at least some of the breaks observed after AMD treatment in G2 represented true DNA damage and were not merely artifacts of fixation.

Chromatids↗
PubMed1977

The nonpolar egg wax lipids of the cattle tick, Boophilus microplus (canestrini).

About 40% of the lipids of the egg wax of Boophilus microplus are nonpolar and comprise hydrocarbons (10%) and wax esters (90%). The hydrocarbon fraction is 87% unbranched alkanes, the major components being n-nonadecane (10.8%), n-eicosane (12.1%), and n-heneicosane (9.8%). This fraction also contains 2,4,6-cholestatriene (4.6%). The majority of the acids are branched (77%) the major components being 12-methyl-tetradecanoic (16.3%) and branched hexadecanoic acids (28%). The major alcohols are n26:0 (20.4%), n28:0 (47.3%) and n36:0 (18.2%). A steroid possibly 2,4,6-cholestatrien-25-ol (5.6%), is also present.

Animals↗
PubMedDate not supplied

Bleomycin-induced chromosome damage in lymphocytes of medullary thyroid carcinoma patients and their family members.

Lymphocyte cultures were treated with bleomycin to see if individuals who exhibit a high rate of spontaneous chromosome breakage also show an exaggerated response to clastogenic agents. For our experimental group, we used patients with medullary thyroid carcinoma and their immediate family members. Lymphocytes from these individuals tend to show high rates of spontaneous chromosome breakage. The average bleomycin-induced breakage rate in this group was significantly higher than that found in the normal controls. In the control group, the distribution of breakage rates was bimodal, with mean values of 0.68 breaks per cell in one group, and 1.84 breaks/cell in the other. The high rate of induced breakage shown by phenotypically normal subjects may mean that these individuals have a potential sensitivity to mutagen exposure.

Bleomycin↗