The precursors, [ 35S]sulfate and [2- 3H]mannose, were used to study the biosynthesis of keratan sulfate and other oligosaccharides on proteoglycans isolated from Day 8 cultures of chick limb bud chondrocytes. After alkaline borohydride treatment, three fractions with sialic acid were separated by molecular sieve chromatography. The first contained keratan sulfate which was purified by digestion w

Proteoglycan monomer and link protein isolated from the Swarm rat chondrosarcoma both contain glycosylamine-linked oligosaccharides. In monomer, these N-linked oligosaccharides are concentrated in a region of the protein core which interacts specifically with both hyaluronate and link protein to form proteoglycan aggregates present in the cartilage matrix. Chondrocyte cultures were treated with tu

The core protein of proteoglycans from cartilage is substituted with glycosaminoglycans as well as N- and O-glycosidically linked oligosaccharides. We have taken advantage of the long intracellular half-life of the core protein precursor to the rat chondrosarcma proteoglycan to study the temporal relationship between the addition of the chondroitin sulfate chains and the O-linked oligosaccharides

macular corneal dystrophy is a human genetic disorder characterized by corneal opacities that arise, in part, from a failure to synthesize mature keratan sulfate proteoglycans. The macromolecules in macular corneas and in keratoconus corneas, an abnormality not involving proteoglycans, were biosynthetically labeled with [3H]mannose and [14C]glucosamine in organ culture, and the keratan sulfate pro

Chondrocytes isolated from the Swarm rat chondrosarcoma were incubated in culture with [1-3H]glucose for 30 min to 8 h. Labeled proteoglycans were isolated, treated with borohydride under alkaline conditions, and the three complex sugar structures purified: N- and O-linked oligosaccharides and chondroitin sulfate chains. The amount of incorporated radioactivity into each component sugar was analyz

Methods were developed for the separation of radioactively labeled carbohydrate components of proteoglycans by isocratic ion-moderated partition HPLC. Neutral sugars were separated after hydrolysis in trifluoroacetic acid with baseline separation between glucose, xylose, galactose, fucose, and mannose. N-Acetylneuraminic acid, N-acetylated hexosamines, glucose, galactose, and xylitol were likewise

Rabbit α1-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α1-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α1-microglobulin has previously been purified from the uri

Rabbit and rat bone matrix were implanted in athymic rat muscle, and the bone yield was measured as total calcium content after 4, 6, and 8 weeks. Matrix from both species induced equal amounts of new bone in the athymic rat. In rabbit and normal rat, the xenogenic matrix induced little or no bone formation. Thus, in the case of rabbit and rat, bone induction is species specific due to immunogenic

Extraskeletal bone formation can be induced in rodents by implantation of demineralised bone matrix and such implantation has been used to treat bone defects in man, but it is uncertain if induction or merely conduction occurs. We studied bone induction in primates by excising segments of the fibulae of adult squirrel monkeys, defatting and demineralising them before reimplanting them into the qua

Joint cartilage consists of cells embedded in a matrix of fibrous collagen within a concentrated water-proteoglycan gel. The integrity of this matrix is crucial for the biomechanical properties of the joint cartilage. The different components of the matrix are synthesized and degraded by the cartilage cells, a process regulated by the amount of mechanical stress applied to the chondrocytes as well

The levels of proteoglycan antigen were measured in joint aspirates from the hip of children with transient synovitis, septic arthritis, Legg-Calve-Perthes' disease and congenital and traumatic dislocation. Significantly increased levels were found in children with transient synovitis and septic arthritis as compared with other conditions. We propose that the proteoglycan antigens in the joint flu

A titanium implant in which a conduit is gradually filled with ingrowing bone (the Bone Harvest Chamber) has been modified to allow continuous local treatment of the conduit tissue with biochemical agents. Implants were inserted bilaterally in rabbit tibiae. The tissue content of the bone ingrowth conduits was studied with histology, 99mTc-MDP scintimetry and measurements of total calcium content.

Local, superficial damage was detected and localized on an 8 × 2-m concrete floor slab using a structural health monitoring system. A total of 30 piezoelectric transducers, placed in a grid, transmitted and received continuous ultrasonic waves that were measured using a lock-in amplifier. Tomography was used to create images from the measured amplitude and phase of the continuous waves between all

The ReO3-type structure NbO2F, niobium dioxyfluoride, has been studied at high pressures using diamond anvil cells and synchrotron X-ray radiation. High-pressure powder diffraction measurements have been performed up to 40.1 GPa. A phase transition from the cubic (Pm3m) ambient pressure structure to a rhombohedral (R3c) structure at 0.47 GPa has been observed. Rietveld refinements at 1.38, 1.96, 3

We have investigated the local atomic environment of the Ga atoms in an InxGa1-xN single quantum well structure using Optically Detected Extended X-ray Absorption Fine Structure (OD-EXAFS). A comparison of the OD-EXAFS data with a theoretical model shows the technique to be site selective for this particular structure and reveals that the quantum well emission originates from regions with x=0.15.