Establishment and characterization of continuous cell line MTC-SK derived from a human medullary thyroid carcinoma.

Tumor cells of a human medullary thyroid carcinoma were isolated and propagated in tissue culture. Several cell lines with different morphology developed from the primary culture, among others a fibroblast-like growing cell line (MTC-F) and a cell line growing as a suspension of single cells and spherical cell clusters (MTC-SK). The MTC-SK cell line was serially propagated for 90 passages, over 3 years. When examined at different times throughout the in vitro period, MTC-SK exhibited properties characteristic of medullary thyroid carcinomas: the cells maintained their epithelioid morphology; endocrine granules were demonstrated in the cytoplasm by electron microscopy; in situ hybridization confirmed the production of calcitonin- and bombesin-mRNA (gastrin releasing peptide); the cells revealed positive immunoreactivity with antibodies to calcitonin, calcitonin gene-related peptide, and bombesin. The in vitro properties of the MTC-SK cells corresponded to the results obtained from the tissue of origin. Cytogenetic studies of the MTC-F cell line revealed a supernumerary metacentric chromosome (20?). In the MTC-SK cell line the predominant findings were terminal chromosomal rearrangements most frequently concerning chromosome 11p, i.e., the locus of the calcitonin and calcitonin gene-related peptide genes and the H-ras oncogene, and a characteristic instability of the centromeric region of chromosome 16 and somatic pairing of the homologous chromosomes 16.

The effect of nerve growth factor (NGF) on the catecholamine contents of two human pheochromocytomas in tissue culture.

Two further cases of human pheochromocytomas were kept in tissue culture for three months. The cultures were parted into two groups: one group was treated with nerve growth factor (NGF), the other group served as the control. The catecholamines in the medium were determined radioenzymatically (Da Prada). NGF-treatment led to lower contents of adrenaline, noradrenaline and dopamine. Cultures without NGF had higher levels. Electron micrographs showed catecholamine granula during the whole culture period. NGF treated cultures contained more catecholamine granula than the untreated cultures. Though the number of catecholamine granula was increased by the NGF-treatment, the medium contained less catecholamines than in untreated cultures. It may be concluded that NGF influences the liberation of adrenaline, noradrenaline and dopamine in tissue culture: though NGF treated cells contained more catecholamine granula, the catecholamines were retained in the pheochromocytoma cells.

Pretransplantation treatment of human teeth in tissue culture combined with storage in liquid nitrogen. A scanning electron microscopic study.

A combined method of tissue culture and storage in liquid nitrogen is described, which is suitable for covering the root surface of transplantable teeth with a dense cell layer: after an initial period of 10 days in tissue culture the teeth are stored in liquid nitrogen. 10 days before a transplantation the teeth are thawed and cultured again for 10 days. By this pretransplantation treatment a densely grown periodontal cell layer as well as an unlimited storage time are achieved.

Long-term tissue culture of human pheochromocytomas.

Two human pheochromocytomas were cultured for long periods. One was cultured for a year, the other is still growing after a cultivation time of seven months. Though decreasing with the age of cultures the cells contained catecholamines all the time. Catecholamines were demonstrated by electron microscope, by fluorescence histochemistry and by Vulpian's and Da Prada's methods. Both pheochromocytomas were responsive to Nerve Growth Factor and showed dose-dependent development of neurite-like processes.

Effects of adrenaline-tablets on rat heart cells in tissue culture at normal and raised temperature.

Primary cultures of rat heart cells were incubated at 37 degrees C or 39.5 degrees C. For permanent treatment with adrenaline recently developed tablets were added to the cultures. After 10 hours the cell counts, glucose, lactate, LDH, alpha-HBDH and GOT were determined. Permanent adrenaline-application led to a decrease of cell counts, an increase of lactate, LDH, alpha-HBDH and GOT. The results indicate an injured membrane function of rat heart cells. Raised temperature sensitized the cells for adrenaline-treatment.