Hydrodynamic effects on animal cells grown in microcarrier cultures

Hydrodynamic phenomena in microcarrier cultures are investigated with regard to the development of improved reactor designs for large-scale operations. New concepts and theoretical models that describe new data as well as previously published data are presented.     

The effects of epidermal growth factor on neural crest cells in tissue culture

Epidermal growth factor (EGF) stimulates the release of hyaluronic acid (HA) and chondroitin sulfate proteoglycan (CSPG) from quail trunk neural crest cultures in a dose-dependent fashion. It also promotes the expression of cell-associated heparan sulfate proteoglycan (HSPG) as detected by immunofluorescence and immunoprecipitation of the 3H-labeled proteoglycan. Furthermore, EGF stimulates [3H]thymidine incorporation into total cell DNA. These results raise the possibility that EGF or an analogous growth factor is involved in regulation of neural crest cell morphogenesis.     

Epithelial cells in tissue culture

In this review the characteristics of established renal and intestinal epithelial cell lines are described by summarizing the accumulated literature about specific properties retained by the cells in tissue culture. Furthermore, brief examples are given for the use of cultured epithelia as model systems to study epithelial transport and metabolic functions, epithelial cell polarity, and aspects of the differentiation and maturation of epithelia by physiological, biochemical and genetic, or cell and molecular biological approaches.     

Ependymal cells in tissue culture

Summary Ciliated ependymal cells from various locations of the ventricular system of mammals showed outgrowth either in the form of epithelial sheets or in the form of pools and elongated double rows, dependant on the site from which the ependyma was taken and on the original orientation of the cells in respect to the cover slip.The ependymal cilia in such cultures were shown to be moving at a rate of 51/2 to 6 times per second. The movement of the cilia of adjacent cells was apparently well coordinated causing the surrounding fluid to flow in a particular direction.The effect of physiological saline, morphine sulfate, ethyl and methyl alcohol on the ciliary motility has been studied in living cells with phase contrast cinematography.Grateful acknowledgement is made to Messers G. Lefeber, E. Pitsinger and J. Carnes for indispensible aid with photographic work. Mrs. J. Finerty and Mrs. W. Hild contributed generously in the management of the tissue cultures and in executing staining procedures.This investigation was supported by a research grant [PHS B-364 (C3)] from the National Institute of Neurological Diseases and Blindness, of the National Institutes of Health, Public Health Service, administered by C. M. Pomerat.     

The effects of serum albumin and phospholipid on sterol exretion in tissue culture cells

Serum albumin was an effective as whole serum or α-globulins in facilitatting sterol release from strain L mouse fibroblasts. Commercial bovine serum albumin preparations, however, had markedly different absolute effects in this regard. These differences were attributable to the variation in phospholipid content of these products. All but one of these albumins enhanced sterol release when supplemented with phospholipid. The exception was fatty acid-poor albumin which contained an adequate amount of phospholipid. Among the phospholipids examine, lecithin proved to be most effective, while phosphatidylethanolamine had little potentiating influence. As the unsaturation of the test lecithins increased, enhancement of sterol release decreased. The potentiating effect of the phospholipid was in turn dependent on the protein used, since the phenomenon was not observed with non-serum proteins like ovalbumin or with non-transport serum proteins such as γ-globulins. The results of these studies raise the possibility that serum albumin together with phospholipid can play an important role in sterol release in tissue cultured cells.     

Irradiation of cells in tissue culture

Summary Cultures of human amnion were employed to check the hypothesis that cell strains with heteroploid chromosome counts regularly produce giant cells within 12 days following treatment with 2000 r and 4000 r of gamma irradiation from a cobalt source, while this response has not been obtained from primary cultures whose cells were presumed to be diploid.The giant cell reaction not only was obtained from two transfer passage lines of a well-established amnion strain developed at Berkeley (No A 185-21C-26 and No A 185-21C-45) but was also found for a 20-day second passage culture of amnion. Since this line has continued to reproduce at a rapid rate, it is presumed to have assumed the features of a typical strain within the period of observation. This impression was reinforced by the finding that the chromosome number for 32 cells fixed on the 35th day had a modal value of 67.In contrast, both untrypsinized and trypsinized spindle cells in primary cultures as well as unaltered epithelial elements which had not been subcultured gave no evidence of giant cell formation 12 days after exposure to 2000 r and 4000 r from a Cobalt⁶⁰ source.These data lend evidence that giant cell formation is related to the chromosomal constitution of the irradiated elements.This research was supported by funds provided under Contract AF 18(600)-1263 with the School of Aviation Medicine, USAF, Randolph Air Force Base, Texas.Fellow of the Instituto de Alta Cultura and the Fundacão Calouste Gulbenkian of Lisbon, Portugal.Tobacco Industry Research Committee Fellow.     

Irradiation of cells in tissue culture

Summary Strain cultures of the cervical carcinoma HeLa (Puck-clone), human fetal intestinal epithelium (Henle) and adult human skin (NCTC clonal 2414) were used in Rose chambers for gamma irradiation at 2000 r and 4000 r from a Cobalt⁶⁰ source.Phase contrast, time-lapse cinematographic records generally made from one to 5 days following irradiation yielded a total of more than 6000 feet of 16 mm film records for analysis.Cell enlargement was regularly observed. Telo-reduplication, including a second division is reported. Multinucleation arising from cells with single and multiple nuclei producing one or two daughter cells with numerous micronuclei was found for all three strains.It is believed that these mitotic anomalies represented a quantitative rather than a qualitative difference between irradiated and control cultures.The method permits an accurate assessment of the divisional potentialities of living cells during long periods of life in vitro under experimental conditions.This research was supported by the USAF under Contract No. AF 18(600)-1263, monitored by the School of Aviation Medicine, USAF, Randolph Air Force Base, Texas.Captain, USAF (MSC).     

Irradiation of cells in tissue culture

Summary The susceptibility of giant cells which had been induced by 1000 to 4000 r of gamma irradiation from a Cobalt⁶⁰ source was studied in comparison to unirradiated cultures. Three human lines were utilized: a synovial cell (McCoy), an amnion (Fernandes) and a fetal lung (Nakanishi). In the amnion line a complete cytopathogenic effect was observed in the giant cells at the beginning of the third day after inoculation as compared to a similar effect produced on the fifth for the corresponding unirradiated control elements. A similar difference of two days was noted for the synovial cells. The virus titers of the amnion line were similar while the synovial cells produced a difference of approximately one logarithm for the virus obtained from the giant elements. The peak for the viral titer was reached earlier with the use of the irradiated cells.After treatment with 2000 r of gamma irradiation, the fetal lung strain which had not been found susceptible to bluetongue virus showed a complete cytopathogenic effect four days following virus inoculation.Giant cells were observed with phase contrast microscopy and following staining in order to study the lesions caused by the virus. Time-lapse phase contrast cinematography was also employed in the study of the giant cell-virus system. No specific lesions were observed.This research was supported by funds provided under Contract AF 41(657)-198 with the School of Aviation Medicine, USAF, Randolph Air Force Base, Texas.Fellow of the Instituto de Alta Cultura and the Fundaçaõ Calouste Gulbenkian of Lisbon, Portugal. Permanent address: Laboratorio Nacional de Investigação Veterinária, Lisbon, Portugal.