Isolation of pituitary fibroblast growth factor by fast protein liquid chromatography (FPLC): partial chemical and biological characterization

Bovine pituitary fibroblast growth factor has been purified 222,000-fold to homogeneity by a combination of differential salt extraction, gel filtration, and ion exchange chromatography on Mono S column. Pituitary FGF is a single-chain polypeptide with an apparent molecular mass of 15,800 and an isoelectric point of 9.6. It is highly active in triggering the proliferation of bovine and human vascular endothelial cell [half-maximal stimulation at 23-40 pg/ml (1.5-2.6 pM) and saturation between 140 and 280 pg/ml (9.3-18.6 pM)]. It displays a similar activity on bovine vascular smooth muscle cells, corneal endothelial cells, granulosa and adrenal cortex cells, and rabbit costal chondrocytes.     

Further observations on the fine structure and development of the infracerebral complex (“infracerebral gland”) of Nereis limnicola (Annelida,Polychaeta)

Cell and Tissue Research - The infracerebral complex consists of: (a) two types of ependymoid infracerebral cells located on the ventral surface of the brain, adjacent to a coelomic sinus and blood...     

Nitrification and nitrate uptake: Leaching balance in a declined forest ecosystem in eastern France

Nitrate uptake and leaching were measured during one year in a declined fir forest on the Vosges highlands (eastern France), in order to investigate whether excess nitrification could be responsible for a deleterious acidification of the ecosystem. Nitrate uptake by the vegetation was active mainly from spring to early fall, and then reached about 66 kg N ha^-1. No significant leaching loss occurred during the growth period of the vegetation. Significant nitrate leaching occurred in winter (about 17 kg N ha^-1). During fall and winter the nitrification rate was of the same magnitude as values reported for other ecosystems, and, thus, was not considered to be abnormaly strong. No abnormal temporal discoupling of nitrate production and nitrate uptake occurred in the ecosystem, and forest decline must therefore have some other cause.     

Transgenic Analysis of a PotentialHoxd-11Limb Regulatory Element Present in Tetrapods and Fish

Genes of theHoxDcomplex related to theDrosophila Abd-Bgene are involved in the morphogenesis of vertebrate paired appendages.Hoxd-11,for instance, is necessary in combination with otherHoxgenes for the proper development of different parts of the tetrapod limbs. Sequence comparisons between the mouse, chicken, and zebrafishHoxd-11loci have revealed the conservation of several blocks of DNA sequence which may be of importance for the regulation ofHoxd-11expression. We have used transgenic mice to show that one of these conserved elements specifically drives expression in a proximal-posterior part of developing forelimbs. Production of mice transgenic for a full fishHoxd-11construct as well as for mouse–fishHoxd-11chimeric constructs shows that the fish counterpart of this sequence is able to elicit expression in mouse forelimbs as well, though in a slightly different domain. However, this fish element requires the presence of the mouse promoter and does not work in its own context. These results are discussed in light of both the control ofHoxdgene expression during limb development and the use of a comparative interspecies approach to understand the regulation of genes involved in vertebrate development.