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D J Hulmes

Publications and source records attributed to D J Hulmes.

59 records · Page 4Linked to original sources
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Degenerative joint disease in poultry--differences in composition and morphology of articular cartilage are associated with strain susceptibility.

The morphology and basic biochemical composition of articular cartilage from two strains of fowl were examined. Broiler breeder fowl are considered susceptible to degenerative joint disease (DJD); histological examination of one-year-old broiler breeders showed in some samples, articular cartilage thinning, fibrillation and chondrocyte cluster formation, features considered typical of DJD. Examination of similar samples from laying strain fowl showed only minor age-related changes such as some slight cartilage thinning and very mild fibrillation. The articular cartilage from the broiler breeder birds was significantly more hydrated with a higher uronic acid content than that of the laying strain birds. In addition, unloaded articular surfaces such as the proximal humerus had significantly higher amounts of uronic acid than the loaded cartilage surfaces of the proximal tarsometatarsus and the distal tibiotarsus; this suggested that the joint loading may have a role in any biochemical differences found between joints and between strains of fowl. These findings concur with other reports in mammals that showed increased hydration and uronic acid in association with early DJD and in models of osteoarthritis (OA). Thus, despite some differences between avian and mammalian articular cartilage, studies on avian DJD may give insights into mammalian disease.

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Quasi-hexagonal molecular packing in collagen fibrils.

Collagen molecules in native 66.8 nm (D) periodic fibrils are widely believed to be assembled into discrete, rope-like substructures, or microfibrils. Several types of microfibril have been proposed (2, 4, 5, 7- and 8-stranded) mainly on the basis of information contained in the medium angle X-ray diffraction patterns of native tendon fibres. These patterns show a series of equatorial and near-equatorial Bragg reflections which indicate that the collagen molecules are arranged on a three-dimensional crystalline lattice. The 4-stranded, 5-stranded and 8-stranded microfibrils are D-periodic with approximate diameter 3.8 nm, and these and the 2-stranded model are supposed to be packed on a three-dimensional lattice whose basal unit cell, (approximately) perpendicular to the fibril axis, is tetragonal (or quasi-tetragonal)with side a, a square root 2 or 2a, where a is approximately 3.8 nm. In this paper we describe a re-interpretation of the X-ray data which leads to a new model for the crystalline regions of the fibril, based on quasi-hexagonal molecular packing without microfibrillar sub-structures, and hence having the character of a molecular crystal.

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Changes in proteoglycan content of articular cartilage during avian degenerative joint disease.

OBJECTIVE: To determine the biochemical changes in articular cartilage composition associated with the development of avian degenerative joint disease (DJD) in ad libitum fed broiler fowl, in comparison to feed-restricted broilers and J-lin fowl (non-susceptible to DJD). METHODS: Articular cartilage from the distal tibiotarsus (DTT) was characterised up to age 180 days. Proteoglycan content was determined by uronic acid and sulphated glycosaminoglycan analysis, cellularity by assay for DNA content, and collagen content and crosslinking by hydroxyproline and pyridinoline analysis, respectively. RESULTS: Disease development was accompanied by increased hydration and proteoglycan content (particularly sulphated proteoglycans) and decreased cellularity, with no significant differences in either total collagen content or in mature collagen cross-linking. CONCLUSION: The biochemical features of avian DJD are similar to those observed in other animal models. This bipedal model is exceptional however since cartilage alterations occur spontaneously and in a load-dependent manner.

Amino Acids↗
PubMedDate not supplied

Effects of body mass and genotype on avian degenerative joint disease pathology and articular cartilage proteoglycan distribution.

OBJECTIVE: The objective of this study was to investigate the role of body mass and genotype in the development of avian degenerative joint disease (DJD). METHODS: Layer strain and broiler strain fowl, fed either ad libitum or on a restricted diet, were kept under identical conditions for up to a year. At various time points cartilage samples were taken from the distal tibiotarsus (DTT), proximal tarsometatarsus, antitrochanter and proximal humerus. All samples were assessed for gross morphology and histopathology, and in some samples the cartilage proteoglycan distribution was investigated by Safranin O staining. RESULTS: Layer strain fowl did not develop DJD. Heavy ad libitum fed broiler strain fowl developed DJD earlier and more severely than lighter, feed restricted, broiler strain fowl. The articular surface of the DTT was worst affected by DJD. Safranin O staining of DTT samples (age 180 days) from the ad libitum fed broilers revealed variable proteoglycan distribution in the articular cartilage. Some areas were intensely stained throughout all zones, whereas other areas showed no staining in any zone. Age matched, non-diseased DTT samples from feed restricted broilers showed a more consistent staining pattern with little staining in the surface zone and more in the middle and deep zones. CONCLUSIONS: These data indicate that avian DJD is body mass mediated in broiler strain fowl, and that proteoglycan distribution is altered in diseased cartilage.

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