Do we need retarded delivery of bone growth factors in facial bone repair? An experimental study in rats.

The aim of the present study was to evaluate the effect of different dosages of retarded vs. rapid release of bone morphogenic protein 2 (BMP2) at different recipient sites. Porous composite poly(D,L-lactic acid) (PDLLA)/CaCO3 scaffolds were loaded with three different dosages of rhBMP2 (24 µg, 48 µg and 96 µg) and implanted, together with blank controls, both into non-healing defects of the mandibles and into the gluteal muscles of 24 adult male Wistar rats.

Regulation of thyroid cell proliferation by TSH and other factors: a critical evaluation of in vitro models.

TSH via cAMP, and various growth factors, in cooperation with insulin or IGF-I stimulate cell cycle progression and proliferation in various thyrocyte culture systems, including rat thyroid cell lines (FRTL-5, WRT, PC Cl3) and primary cultures of rat, dog, sheep and human thyroid. The available data on cell signaling cascades, cell cycle kinetics, and cell cycle-regulatory proteins are thoroughly and critically reviewed in these experimental systems. In most FRTL-5 cells, TSH (cAMP) merely acts as a priming/competence factor amplifying PI3K and MAPK pathway activation and DNA synthesis elicited by insulin/IGF-I.

Loss of several cell functions including okadaic acid-induced apoptosis after multiple passages in FRTL-5 cells.

In FRTL-5 cells, cultured over a period of more than 3 years, different properties of the cells have been observed to undergo spontaneous changes in the course of aging, i.e. after an increase in the number of passages.

Insulin and TSH promote growth in size of PC Cl3 rat thyroid cells, possibly via a pathway different from DNA synthesis: comparison with FRTL-5 cells.

In the rat thyroid cell lines PC Cl3, FRTL- 5 and WRT, proliferation is mainly regulated by insulin or IGF, and TSH. However, the mechanism regulating cell mass doubling prior to division is still unknown. Our laboratory has shown that in dog thyroid cells insulin promotes growth in size while TSH in the presence of insulin triggers DNA replication.

Cytotoxic effects of iodide on thyroid cells: difference between rat thyroid FRTL-5 cell and primary dog thyrocyte responsiveness.

In order to investigate whether the cytotoxic effect of iodide observed in the thyroid gland represented an apoptotic phenomenon, in vitro experiments were performed using the FRTL-5 thyroid cell line and dog thyrocytes in primary culture. These cells were exposed to iodide under various incubation conditions. Apoptosis was assessed through the analysis of DNA breakdown, i.