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

Rib cartilage from growing guinea pigs and epiphyseal cartilage from Beagle puppie were separated into three fractions, representing non-mineralized, low mineralized, and high mineralized, tissue, by centrifuging finely ground material in acetone/bromoform density gradients. Following extraction under dissociative conditions, the proteoglycans were fractionated by density gradient ultracentrifugat

The compressibility and thermal expansion of the cubic silicon nitride (c-Si3N4) phase have been investigated by performing in situ x-ray powder-diffraction measurements using synchrotron radiation, complemented with computer simulations by means of first-principles calculations. The bulk compressibility of the c-Si3N4 phase originates from the average of both Si-N tetrahedral and octahedral compr

Proteoglycan monomers from guinea pig costal cartilage, bovine nasal and bovine tracheal cartilage were observed in the electron microscope after being spread in a monomolecular layer with cytochrome c. The proteoglycan molecule appeared as an extended central core filament to which side chain filaments were attached at various intervals. The molecules from the three sources displayed great ultras

The crystal structures of tert-butyl-tris(trimethylsilyl)silane, Si[C(CH3)3]1[Si(CH3)3]3 (Bu1), and di-ferr-butyl-bis(trimethylsilyl)silane, Si[C(CH3) 3]2[Si(CH3)3]2 (Bu2), at room temperature and at 105 K have been determined by X-ray powder diffraction; the high-pressure behavior for pressures between 0 and 5 GPa is reported. The room-temperature structures have cubic Fm3→m symmetry (Z = 4) with

Fetal guinea-pig epiphyseal chondrocytes were cultured in monolayers and as aggregates in the presence of antimicrotubular agents. Colchicine and vinblastine caused a dissociation of the Golgi complex, in addition to the disappearance of microtubules. Synthesis and secretion of proteoglycans and collagen were studied using radioactive precursors. Colchicine inhibited the synthesis of proteoglycans

An experiment was performed in water resources engineering department laboratory at Lund University of Sweden to investigate the behavior of inclined negatively buoyant jets. Such jets arise when brine is discharged from desalination plants and improved knowledge of their behavior is required for designing discharge systems that cause a minimum of environmental impact on the receiving waters. In t

The turnover in vivo of proteoglycans of guinea pig costal cartilage was investigated using Na2 35SO4 as precursor. Proteoglycans were extracted with guanidine · HCl, at both low and high ionic strength, and purified and fractionated by ultracentrifugation in CsCl gradients under associative and dissociative conditions. The results suggest that the sulfate is incorporated into macromolecules of at

High-pressure X-ray diffraction, Mössbauer, and Raman studies in the antiferromagnetic insulators RFeO3 orthorhombic perovskites (R = Pr, Eu, Lu) disclose an unusual phenomena of a reversible first-order isostructural phase transition around 50 GPa concurring with an abrupt ∼ 5% volume decrease. It is shown experimentally that this transformation concurs with, and is driven by, a high-to-low-spin