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Biomedical subjects

G L Grove

Publications and source records attributed to G L Grove.

49 records · Page 3Linked to original sources
PubMed1979

Application of microspectrophotometry to biomedical research.

During recent years, the utilization of microspectrophotometry in biomedical research has increased at a rapid pace. This growth has been facilitated by both the advent of commercially available instruments which are reliable and manageable as well as improvements in histochemical techniques. This paper discusses the fundamental principles of visible light microspectrophotometry and important design criteria as well as briefly reviewing a wide range of applications. Special emphasis will be given to the Vickers M85 scanning integrating microspectrophotometer which is being routinely employed for both clinical and laboratory studies by a sizeable number of investigators.

Cell Nucleus↗
PubMed1977

Characterization of the cell cycle of cultured human diploid cells: effects of aging and hydrocortisone.

Age-related changes in the cytokinetics of human diploid cells in vitro have been compared in normal cultures and in cultures in which lifespan has been prolonged by the addition of hydrocortisone to the medium. For both cultures, with advancing age the fraction of cells in the actively proliferating pool decreased and the intercellular variation in cell cycle times increased. The average cell cycle time was prolonged during aging due almost entirely to changes in the duration of G1. The duration of S remained constant, while a small delay in G 2 was observed in late passage cells near the end of their lifespan. Although the same pattern of change in proliferative parameters occurred in both control and hydrocortisone-treated cultures, the changes were somewhat delayed in the presence of the steroid. The results are interpreted in terms of several cell cycle models and suggest that the events controlling cell proliferation are sensitive to hydrocortisone modulation during the G1 and possibly the G2 periods.

Cell Division↗
PubMed1977

Cell size in aging monolayer cultures.

Changes in the size of the area covered by individual cultured WI-38 cells as the cultures age have been studied by using a new microphotographic paper cutout technique. This method is nondestructive and noninstrusive and avoids a number of artifacts which can occur in the measurement of suspended cells. The measurements reveal that the decreased cell yield of late passage cultures reflects not only the appearance of a subpopulation of larger cells but also the failure of the cells to utilize all the growth surface available to them.

Cell Division↗
PubMed1977

Hydrocortisone effects on cell proliferation: specificity of response among various cell types.

The effect of 14 micrometer hydrocortisone (HC) on the proliferative activity of various vertebrate cell lines has been measured. Such activity in human deploid cell line WI-38 was enhanced by HC addition whereas in a number of other vertebrate cell lines under identical conditions HC was inhibitory to growth. We examined the effects of HC on normal human diploid cells other than WI-38; some were stimulated, some inhibited and some were unresponsive. The results suggest that cells derived from different human tissues retain in vitro some aspects of their cell-specific hormonal responses.

Aging↗
PubMed1976

Cytophotometric studies of epidermal proliferation in psoriatic and normal skin.

Cytophotometric measurements of single-cell DNA content were used to study human epidermal cell proliferation in vivo. It was found that Feulgen-DNA profiles can be used to assess proliferative activity in involved, uninvolved, and nonpsoriatic skin. Profiles of involved psoriatic skin were bimodal as is characteristic of actively proliferating populations. This was due to the presence of cells with twice (2C--presynthetic) or four times (4C--post-synthetic) the amount of DNA of the gametes, separated by the intermediate values of cells undergoing scheduled DNA synthesis. Profiles of uninvolved psoriatic as well as nonpsoriatic epidermis were unimodal with the majority of cells containing a 2C amount of DNA incating relatively low levels of proliferative activity. The observed variations in proliferative activity of these samples are discussed in terms of two alternative models. Since radioisotopes are not required, this technique presents a useful approach to studying human epidermal proliferation in vivo.

Cell Division↗
PubMed1976

The 'transition probability model' and the regulation of proliferation of human diploid cell cultures during aging.

Genealogies derived from time-lapse cinemicrophotographic studies of aging human diploid cell cultures were analysed in terms of the 'transition probability' model. It was found that the distribution of intermitotic times obtained from middle passage cells deviated only slightly from that predicted by the model. In contrast, the plot for late passage cultures did not fit the predicted pattern and appeared to be composed of multiple curves. These changes are discussed in reference to cellular senescence as expressed by normal human diploid cells in vitro.

Cell Division↗