A pure culture of oligodendrocytes has been developed starting from brain hemispheres of newborn rats. Various effects of acidic and basic fibroblast growth factors (FGFs) on the development of oligodendrocytes have been examined and compared. Both factors elicited similar effects, i.e. stimulation of the proliferation, inhibition of the specific activity of the marker enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase and decrease of the ratio of myelin basic protein positive cells. These results indicate that FGFs are very potent mitogens for oligodendrocytes, even in the absence of other cell types, but that they elicit a negative effect on the cell maturation, possibly related to their strong effect on proliferation.

Ad CFTR, a replication-deficient adenovirus expressing the human cystic fibrosis transmembrane conductance regulator (CFTR), was administered by aerosolization in a single escalating dose to three pairs (cohorts) of cystic fibrosis (CF) patients. Buffer only was administered to the nose and lungs 9-14 days before nasal instillation of virus followed the day after by aerosolization of Ad CFTR to the lung. Nasal doses (defined in terms of viral plaque forming units, pfu) were 10(5), 10(7), and 4 x 10(8), whereas aerosolized doses were 10(7), 10(8), 5.4 x 10(8) for each cohort, respectively. No acute toxic effects were observed in the first 4 weeks after virus treatment. Shedding of infectious Ad CFTR was never detected, whereas detection of vector DNA sequences and CFTR expression demonstrated DNA transfer to the nose and airways of patients. No significant deviations in immunological and inflammatory parameters were observed in serum and in bronchoalveolar lavage (BAL). Importantly, for all patients, the serum anti-adenovirus antibody levels did not change significantly from baseline and no antibodies against adenovirus were found in BAL.

Astroblasts from brain of newborn rat can survive and even proliferate to some extent in a chemically defined medium containing no other growth factor than insulin, providing they are grown first in the presence of fetal calf serum for at least 4 days (Weibel et al., 1984, Int. J. devl Neurosci. 2, 355-366). We found that thrombin is a potent mitogen for these cells, in vitro. The mitogenic activity of thrombin for astroblasts can be compared to that of the astroglial growth factor on astroblasts. However, in contrast to the bFGF, thrombin does not modify significantly the morphology of the cells and their synthesis of glutamine synthetase, an astroglial marker in rat brain. Some other proteases are also able to stimulate the proliferation of astroblasts, but to a lesser extent than thrombin. Thrombin does not stimulate the proliferation of oligodendroblasts from newborn rat and of neuroblasts from 13-day-old rat embryo. These results suggest that in the central nervous system thrombin might play a role in the induction of astrocyte proliferation after brain injury.

The two fibroblast growth factors called acidic and basic FGF (aFGF and bFGF) show a strong homology (55%) of their amino acid sequence (Esch et al.: Proc. Nat. Acad. Sci. USA 85:6507-6511, 1985). The effects of these factors on the rate of proliferation of rat astroblasts and on the expression of glutamine synthetase activity in cells grown in primary culture were investigated and compared under various culture conditions. In all the experimental conditions used, both growth factors triggered the proliferation of the cells to the same extent and with similar dose dependence. The mitogenic activities of aFGF and bFGF were potentiated similarly by heparan sulfate and by heparin, with a maximum stimulation of about 100% at 100 micrograms/ml heparin. Treatment of the cells with either of the two factors resulted in identical enhancement of the activity of glutamine synthetase relative to total proteins. These results suggest that both factors act either through the same membrane receptors or through different receptors that mediate nearly identical effects.

No abstract

Transgenic mice were generated in which 5 kb of the 5′ flanking promoter region of the human Factor IX (FIX) gene fused to various FIX constructs (gene, minigene and cDNA) were stably integrated in the germ line. Several transgenic mouse lines expressed high circulating levels of active and correctly processed recombinant human FIX. The presence of at least one FIX intron had a positive effect on the expression. The FIX transgenes were expressed in a tissue‐specific manner in the liver of transgenic mice. By crossing transgenic mice synthesizing FIX with others prone to develop hepatoma, progeny which co‐express the transgenes in hepatocytes were obtained. Hepatoma‐derived cell lines were shown to have a differentiated phenotype and secrete active human FIX for many generations.

Reactive gliosis was revealed by immunocytochemistry using antibodies against the glial fibrillary acidic protein (GFAP) after a stab or an electrolytic lesion administered to the cerebral cortex, corpus callosum, striatum, or hippocampus of a 6-day-old rat. The intensity of the gliosis was about the same in the various structures injured and did not change with the delay of 3, 7, or 20 days between the injury and the sacrifice of the animals. When basic fibroblast growth factor (bFGF) was injected in the lesion locus just after the lesion was performed, it resulted (as soon as 3 days after injury) in a strong astrogliosis that was enhanced after a delay of 7 days, the astrocytes in the lesion area exhibiting enlarged cell processes and intense GFAP-positive immunoreactivity. After a delay of 20 days, the astrocytes were not dispersed any more but packed in three or four layers along the borders of the lesion, thus reducing its extension. This suggests a possible role for bFGF in promoting scar formation following brain injury.

The effects of acidic and basic fibroblast growth factors (aFGF and bFGF) on the morphology of cultured rat astroblasts and on the expression of glial fibrillary acidic protein (GFAP) were compared. The addition of either aFGF or bFGF affected the morphology of the flat, irregular, polygonal-shaped astroblasts, which formed processes and acquire a fibrous appearance. Appreciable different morphological aspects were observed between aFGF- and bFGF-induced cells, essentially between 11 and 14 days in culture. In the presence of bFGF the astroglial cells were more fibrous with a more compact perikaryon as compared to aFGF treated cells. At the ultrastructural level abundant intermediate filaments were observed in astroglial cells as an effect of aFGF and rare filaments but numerous microtubules were seen in bFGF-treated cells. The immunoreactivity for GFAP increased with time in culture and was much stronger in aFGF-treated cells compared to bFGF-treated cells at day 14. An intense positive staining was observed in the somata of the astroglial cells and their processes in the presence of aFGF, while essentially the processes were stained in the presence of bFGF. After 21 days in culture GFAP immunoreaction was also found in the perikarya of cells treated with bFGF. These results show that rat astroglial cells respond somewhat differently to aFGF and bFGF.