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Biomedical subjects

T K Taylor

Publications and source records attributed to T K Taylor.

At least 127 records · Page 7Linked to original sources
PubMed1976

N6,O2'-dibutyryl adenosine 3', 5'-monophosphate-stimulated release of proteoglycans from cultured immature rabbit ear cartilage.

The stimulatory effects of N6, O2'-dibutyrl adenosine 3',5'-monphosphate on proteoglycan released from immature rabbit ear cartilage were studied in viltro. Cartilage incubayed in medium containing dibutyryl cyclic AMP resulted in a significant increase of proteoglycans released in concentrations above 0.5 mM. Theophylline (1 mM) which did not significantly stimulate proteoglycans released alone, was found to potentiate the action of this nucleotide. ATP, 5'-AMP and butyric acid in the presence of theophylline, did not stimulate proteolgycans released. The addition of protein or RNA synthesis inhibitors depressed proteoglycans released by dibutyryl cyclic AMP and theophylline. Gel chromatogrphic and chemical investigation of the proteoglycans released into the culture media in the presence of dibutylic cyclic AMP indicated a reduction in the proportion of protein associated with these complexes. This result, together with enzyme inhbitor studies, leads us to speculate that the observed action of dibutyryl cyclic AMP on rabbit ear cartilages may be mediated by the neutral proteases.

Acetylglucosaminidase↗
PubMed1976

Effect of anti-inflammatory drugs on sulphated glycosaminoglycan synthesis in aged human articular cartilage.

The anti-inflammatory drugs, sodium salicylate, indomethacin, hydrocortisone, ibuprofen, and flurbiprofen, were examined for their effects on sulphated glycosaminoglycan synthesis in aged human cartilage in vitro. Cartilage was obtained from femoral heads removed during surgery and drug effects were found to vary significantly from one head to another. Statistical analysis of the results showed that sodium salicylate exhibits concentration-dependent inhibition of glycosaminoglycan synthesis over the concentration range used. Indomethacin, hydrocortisone, and ibuprofen, at concentrations comparable to those attained in man, caused a statistically significant depression of sulphated glycosaminoglycan synthesis in cartilage from some femoral heads but not others, reflecting the variable response of human articular cartilage to anti-inflammatory drugs. Sodium salicylate and indomethacin at higher doses produced significant (Pless than 0-005) inhibition of sulphated glycosaminoglycan synthesis in all femoral heads studied. The results for flurbiprofen were less conclusive; this compound appears not to inhibit glycosaminoglycan synthesis over the concentration range used.

Aged↗
PubMed1976

The collagenous and non-collagenous protein of the canine intervertebral disc and their variation with age, spinal level and breed.

The total nitrogen, collagen and non-collagenous protein (NCP) content of the nucleus pulposus (NP), transitional zone (TZ) and annulus fibrosus (AF) of the beagle (a chondrodystrophoid breed) and greyhound (a non-chondrodystrophoid breed) intervertebral discs have been determined over the age range birth to 124 months. Discs were sampled at three spinal levels - lumbosacral, lumbar and thoracic regions. The beagle NP attains an average NP collagen content of 25% dry weight before 11 months of age, whereas the greyhound NP content is less than 5% collagen for most of its life. The NCP of the young greyhound disc is greater than that of the beagle of corresponding age. Plots of the ratio of collagen/NCP for discal regions at various ages highlight the large differences between the two breeds of dog. It is suggested that these differences in protein distribution are related to the elevated incidence of intervertebral disc prolapse in the beagle.

Aging↗
PubMed1976

A comparative chemical and histochemical study of the chondrodystrophoid and nonchondrodystrophoid canine intervertebral disc.

The chemical composition of the intervertebral disc of 9-month-old chondrodystrophoid and nonchondrodystrophoid dogs was studied for collagen, noncollagenous protein and glycosaminoglycan. Content of these substances differed significantly between breeds. The differences were most marked in the nucleus pulposus; the noncollagenous protein content of the nonchondrodystrophoid breed was higher than in that of the chondrodystrophoid dogs. The total nitrogen value of the nonchondrodystrophoid nuclei pulposi was less than that of the corresponding chondrodystrophoid discs mainly because of the high collagen content of the latter discs. Histochemically, it was found that the nuclei pulposi of the nonchondrodystrophoid breed contains larger amounts of glycosaminoglycan than in the discs of the chondrodystrophoid breeds.

Animals↗
PubMed1976

Seat belt fractures of the cervical spine.

Three unusual injuries of the cervical spine in wearers of safety belts are reported. In each case, the presence of diagonal bruising and abrasions in the line of the sash strap indicated its involvement in the mechanism of the injury.

Accidents, Traffic↗
PubMed1976

The qualitative assessment of glycosaminoglycans in the canine intervertebral disc using a critical electrolyte concentration staining technique.

Through the use of a critical electrolyte concentration staining technique, the glycosaminoglycans (GAGs) in the nucleus pulposus region of the canine intervertebral disc were arbitrarily identified as "hyaluronic acid", chondroitin sulphate and keratan sulphate. Approximate estimates of GAG concentration could be qualitatively deduced by determining the appropriate GAG "ALCIANOPHILIC INDEX". This index was considered to be an effective qualitative adjunct to chemical quantitation of GAGs in the intervertebral disc.

Alcian Blue↗
PubMed1975

The composition and protein metabolism in the immature rabbit intervertebral disc.

The nucleus pulposus (NP) and annulus fibrosus (AF) of immature rabbit intervertebral discs (IVD) have been subjected to the dissociative extraction procedure of Sajdera and Hascall (1969). The soluble, insoluble and unextracted fractions so obtained were analysed for total nitrogen, collagen, tyrosine, uronic acid, hexosamine and sialic acid content. A high proportion of non-collagenous protein, hexose and sialic acid in the NP insoluble fraction suggests the presence of glycopeptides associated with collagen and/or proteoglycans. The levels of proteoglycan in the soluble NP and AF fraction are similar. Immature (soluble) collagen, however, resides largely in the AF region. The metabolism of rabbit IVD protein components was also investigated both chemically and by autoradiography. L-Tyrosine-3,5-H3 was administered intraperitoneally (3 mc/kg) to 4 week-old rabbits. Animals were sacrificed at various time intervals and the harvested tissues extracted as before and lumbar discs collected. The levels of L-Tyrosine-3,5-H3 in the NP and AF insoluble and soluble fractions were determined using a tritium scintillation counting procedure and localisation by autoradiography. Pronounced extracellular activity of proteoglycan and glycoprotein is not evident before 24 hours. Soluble collagen, however, is synthesized and dispersed within 4 hours of isotope administration.

Animals↗
PubMed1975

The characterisation and function of the polysaccharidases of human synovial fluid in rheumatoid and osteoarthritis.

A potential enzymic mechanism for the degradation of glycosaminogly cans was characterised using enzymes found in rheumatoid synovial fluid from the knee joint. This mechanism involves a true hyluronidase together with the concerted action of beta-glucuronidase and beta-N-acetylhexosaminidase. The contribution of the exopolysaccharidases to hyaluronate degradation was demonstrated by the use of specific inhibitors, while the distinct identity of a true hyaluronidase was shown by ammonium sulphate and agarose gel column fractionations. Only the hyluronidase fraction was capable of degrading high molecular weight hyaluronate. The exopolysaccharidase activities were shown to be markedly elevated in rheumatoid as compared to osteoarthritic synovial fluid and also normal serum. On the other hand, hyluronidase was similarly active in rheumatoid and osteoarthritic synovial fluids; both these levels were lower than that of normal human serum. Hyaluronidase in synovial fluid may thus be derived by diffusion from serum, since it is of relatively low molecular weight (60 000). The pH requirements of this enzyme system and the strong inhibition of hyaluronidase by synovial fluid make it unlikely that the mechanism operates extracellularly. It is proposed that as a lysosomal mechanism, however, it is an important contributing factor in the chronic erosion process characteristic of rheumatoid arthritis.

Acetates↗