Johanna G Koster

Learn More
BACKGROUND AND PURPOSE Perinatal hypoxia-ischemia is a major cause of neonatal morbidity and mortality. Until now no established neuroprotective intervention after perinatal hypoxia-ischemia has been available. The delay in cell death after perinatal hypoxia-ischemia creates possibilities for therapeutic intervention after the initial insult. Excessive(More)
The Xenopus homolog of the proto-oncogene wnt-1 (int-1) is transiently expressed during neurula and tailbud stages of early development. To determine the mechanisms involved in the transcriptional regulation of the Xwnt-1 gene, we isolated Xwnt-1 genomic sequences. The promoter activity of the 5' flanking region of the gene was analysed by microinjection of(More)
Protein C inhibitor (PCI) is a heparin binding serine protease inhibitor in plasma, which exerts procoagulant activity by inhibiting thrombomodulin-bound thrombin or activated protein C (APC). Since the role of PCI in vivo is largely unknown we generated genetically modified mice with expression of human PCI mRNA in hepatocytes only. Three transgenic lines(More)
In eukaryotes pre-tRNA species are processed at the 5' end by an endonuclease. Here we describe the first characterization of the structure of a eukaryotic pre-tRNA 5' processing endonuclease. The 5' pre-tRNAase, isolated from X. laevis ovaries, copurifies with a 16S macromolecular complex consisting of at least 14 polypeptides ranging in MW from about(More)
High (pharmacological) doses of glucocorticoids inhibit the proliferation of growth plate chondrocytes, which leads to one of the side-effects of these steroids, namely suppression of longitudinal growth. Growth inhibition by glucocorticoids is thought to be mediated in part by impaired action of components of the IGF axis, which are important for(More)
Overexpression of human insulin-like growth factor II (IGF-II) in transgenic mice does not result in increased overall body growth. The IGF-II overexpression, however, specifically causes growth of the thymus and not of the spleen. We address the question whether the observed differences in growth induction in lymphoid tissues by IGF-II can be related to(More)
Glucocorticoid (GC) treatment in childhood can lead to suppression of longitudinal growth as a side effect. The actions of GCs are thought to be mediated in part by impaired action of the insulin-like growth factors (IGF-I and IGF-II) and their binding proteins (IGFBP-1 to -6). We have studied the effects of GCs on IGF and IGFBP expression at the local(More)
The insulin-like growth factors, IGF-I and IGF-II, and their binding proteins play an important role in the growth and development of the central nervous system. In the brain, colocalization of IGFs and IGFBPs often occurs, suggesting that IGFBPs can modulate IGF action. In one strain of our human (h)IGF-II transgenic mice, which carry an hIGF-II transgene(More)
Supraphysiological doses of glucocorticoids cause growth retardation in both animals and humans. Many studies have addressed the interaction of glucocorticoids with the GH/IGF system, but little is known about the effect of glucocorticoids on T(4)-stimulated growth. The Snell dwarf mouse is deficient in GH, thyroid-stimulating hormone, and prolactin and(More)
Most genomes are much more complex than required for the minimum chemistry of life. Evolution has selected sophistication more than life itself. Could this also apply to bioenergetics? We first examine mechanisms through which bioenergetics could deliver sophistication. We illustrate possible benefits of the turbo-charging of catabolic pathways, of loose(More)