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The ultrastructure of the upper tibial epiphyseal plate during the development of acute, experimental scurvy in the guinea pig was investigated. The cartilage was examined after the animals had been maintained, under standardized conditions, on a scorbutogenic diet for 8, 15, or 23 days. Progressive fine structural changes were observed in the experimental animals. Within the chondrocytes, the cis
The effects of in vivo zinc deficiency and restricted food intake, on the in vitro synthesis of glycosaminoglycans of rib cartilage were studied in the rat. 35S-sulfate and 14C-glucosamine were used as precursors. The glycosaminoglycans were separated on microcolumns and specific radioactivities determined for the different fractions. Chemical analyses showed that zinc deficiency or reduced food i
A rapid method for the separation and quantitative determination, including radioassay, of glucosamine and galactosamine in microgram amounts is described. It is based upon the use of a column of Aminex A-5 ion exchange resin eluted with a phosphate buffer at pH 7.00 and 60 °C. From each fraction half the volume is used for a scaled down Elson-Morgan procedure and other half for liquid scintillati
Guinea pig epiphyseal cartilage was studied ultrastructurally after staining with ruthenium red or Alcian Blue. Extracellularly, the matrix granules were positively stained with both dyes, whereas no apparent staining of the collagen fibrils occurred. Intracellularly, a positive ruthenium red staining of the Golgi vacuole granules was observed. No Alcian Blue staining of the content of the vacuole
Chondroitin sulfate and keratan sulfate in guinea pig costal cartilage, nasal septum cartilage and nucleus pulposus were separated and fractionated by chromatography on CPC-cellulose, ECTEOLA-cellulose and Sephadex G-200 columns. Characterization of the chondroitin sulfates included determination of molecular weight and of the number, and position, of sulfate groups of the disaccharide units. Dist
The effect of the neurotoxic compound 6-hydroxydopamine and its immediate precursor 6-hydroxy-DOPA on noradrenaline uptake and storage in central and peripheral catecholamine neurons of scorbutic and normal guinea-pigs has been investigated. Endogenous noradrenaline in heart and brain as well as the in vitro uptake-accumulation of 3H-noradrenaline in iris and slices of heart and brain were not sig
Fetal guinea-pig epiphyseal chondrocytes were isolated enzymatically, aggregated, and the aggregates maintained in organ culture. As revealed by light and electron microscopy, the cultures produced a typical cartilaginous matrix, but no calcification occurred. Exposure of aggregating cells, or preformed aggregates, to colchicine or vinblastihe at 10-5 M concentration led to disappearance of the mi
This paper analyses the relationship of the accumulation of technological competencies at the firm level, the spatial distribution of the firm's innovation networks and the degree of novelty of product innovation. Firm-based primary data collected in two innovative regions in emerging economies are used to predict higher degrees of novelty in emerging economy firms. Similarly to advanced economy f
The global location of R & D labs by MNCs is a rather new phenomenon; especially when it comes to establishing R & D labs in developing countries. The existing and rather limited literature on globalisation of innovation provides four possible explanations of why multinationals locate R & D labs in developing countries: reduce research costs, access large markets, tap into a large pool
'... this ambitious project definitely succeeds in putting together coherently a relatively recent body of research, and in arguing that a new policy approach to development is needed: one that puts knowledge accumulation at its core, that recognises the complex nature of learning processes and the need of new institutions to stimulate them. For the many who believe in the urgency of revising deve
