Suramin inhibits bFGF-induced endothelial cell proliferation and angiogenesis in the chick chorioallantoic membrane

The effects of suramin, an inhibitor of growth factor mitogenic activity, were evaluated on basic fibroblast growth factor (bFGF)-induced proliferation of bovine aortic endothelial cells and on angiogenesis in the chorioallantoic membrane (CAM) of chick embryos. The role of bFGF gene expression in endothelial cell growth was also investigated by using an antisense oligodeoxynucleotide to bFGF. The 4-fold increase in [3H]-thymidine uptake in endothelial cells in vitro upon stimulation with 10 ng ml-1 of bFGF was inhibited by suramin 300 micrograms ml-1. bFGF antisense oligomer (10 microM) reduced [3H]-thymidine incorporation in exponentially growing cells by 76%; this effect was reversed by bFGF 10 ng ml-1. In the CAM of chick embryos suramin 50 micrograms was a more potent inhibitor of angiogenesis than the combination of heparin 60 micrograms/hydrocortisone 50 micrograms; the mean value of the area with reduced vascularity was significantly larger in suramin-treated CAMs (2.4 cm2) than in heparin/hydrocortisone (0.6 cm2), while the reduction of vascular density was similar (- 35 and - 29% compared to controls, respectively), In conclusion, the effects of treatments with bFGF and bFGF antisense oligomer demonstrate that bFGF plays a relevant role in endothelial cell proliferation and may be the target of suramin since the drug is able to suppress basal and bFGF-induced endothelial cell growth; in addition to this, suramin is a more potent angiogenesis inhibitor in the CAM than the combination of heparin/hydrocortisone

Tooth preparations for complete crowns: an art form based on scientific principles.

In 1747, Pierre Fauchard described the process by which roots of maxillary anterior teeth were selected for the restoration of single teeth and replacement of multiple teeth. Gold or silver pivots (posts) were retained in the roots with the use of a heat-softened adhesive called "mastic," and crown replacements were attached to the pivots. Material and methods. Literature covering 250 years of clinical practice was reviewed with emphasis on scientific data acquired during the last 50 years. Both a MEDLINE search and an extensive manual search were used to locate relevant articles written in English in the last 50 years. Results. Teeth should be prepared so that they exhibit the following characteristics: 10 to 20 degrees of total occlusal convergence, a minimal occlusocervical dimension of 4 mm for molars and 3 mm for other teeth, and an occlusocervical-to-faciolingual dimension ratio of 0.4 or greater. Facioproximal and linguoproximal line angles should be preserved whenever possible. When the above features are missing, the teeth should be modified with auxiliary resistance features such as axial grooves or boxes, preferably on proximal surfaces. Finish line selection should be based on the type of crown/retainer, esthetic requirements, ease of formation, and personal experience. Expectations of enhanced marginal fit with certain finish lines could not be validated by recent research. Esthetic requirements and tooth conditions determine finish line locations relative to the gingiva, with a supragingival location being more acceptable. Line angles should be rounded, and a reasonable degree of surface smoothness is desired. Conclusion. CLINICAL IMPLICATIONS The principles identified in this article can help dentists design, assess, and modify complete coverage tooth preparations to ensure clinical success for the treatment of a variety of unprepared and previously prepared teeth

Inhibition of experimental angiogenesis by the somatostatin analogue octreotide acetate (SMS 201-995)

The present study investigates the effect of the somatostatin analogue octreotide acetate (SMS 201-995) on experimental angiogenesis in vitro and in vivo. Octreotide reduced the proliferation of human HUV-EC-C endothelial cells (mean, -45.8% versus controls at 10(-9) M; P < 0.05) as well as the density of the vascular network of the chick chorioallantoic membrane (mean, -35.7% versus controls at 50 microgram; P < 0.05). Furthermore, octreotide significantly inhibited chick chorioallantoic membrane neovascularization by the human MCF-10Aint-2 mammary cells secreting the angiogenic protein FGF-3. The proliferation of endothelial and smooth muscle cells from rat aorta explants on fibronectin was reduced by octreotide 10(-8) M (mean, -32.6% versus controls; P < 0.05), and a similar effect was produced on cells sprouting from explants cultured in fibrin (mean, -52.9% versus controls; P < 0.05). Topical administration of octreotide 10 microgram/day for 6 days inhibited rat cornea neovascularization induced by AgNO3/KNO3 (mean, -50.6% versus controls; P < 0.05). Octreotide 40 microgram/day i.p was tested on angiogenesis in rat mesentery obtained by i.p. injections of compound 48/80, a mast cell degranulating agent, or conditioned medium from MCF-10Aint-2 cells and was able to reduce the extent of neovascularization (mean, -45.6 and -64.1%, respectively, versus controls; P < 0.05). These data provide evidence that octreotide is an inhibitor of experimental angiogenesis in vitro and in vivo

Age-related changes in the noradrenergic pattern and receptor responses of the rat cardiovascular system after repeated microwave exposure.

In the present research the effect of repeated microwave exposure on the noradrenergic pattern by histofluorescence method and on receptor-mediated responses using alpha and beta agonists in myocardium and aorta of young-adult and aged rats was studied. Young-adult irradiated rats showed an increase in noradrenergic innervation more marked in myocardial tissue, while an increase in maximal response to the agonist was found only at aortic level. Aged stressed rats exhibited an increase in fluorescent fibres at atrial and aortic level, but in the atrial section this increase was found to be less evident than in young-adult animals. Functional data in aged rats revealed a more marked decrease in maximal response ratio (M.R.R.) of myocardial tissue than in young-adult rats, together with a noticeable decrease in maximal response at aortic level. These results indicate no direct correlation between morphological and functional data. Participation of both central and peripheral mechanisms is suggested