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Biomedical subjects

A J Palfrey

Publications and source records attributed to A J Palfrey.

At least 19 recordsLinked to original sources
PubMed1988

Chondrocyte distribution in the articular cartilage of human femoral condyles.

The distribution of chondrocytes throughout the total thickness of articular cartilage from the femoral condyles of infants, children and adults has been studied using serial sections cut parallel as well as perpendicular to the articular surface. The thickness of the articular cartilage was estimated in fixed sections. In one of the adult specimens, the thickness of the articular cartilage was estimated firstly by direct measurement of the cut surfaces of a series of blocks cut from both condyles and then from the number of parallel sections of the cartilage prepared from those blocks. Cell density was highest in the superficial zone of all specimens examined, declining to lower values in the deep zone of the cartilage. Within this pattern the infant specimens had the highest values for cell density and the adults the lowest, with values for children in an intermediate range. There was no significant variation in cell density across the condyles of the selected adult specimen. The absolute values for cartilage thickness depended on the method used, but in general total thickness was found to approximately double from late gestation to maturity. In the selected adult specimen, the cartilage was thickest just anterior and posterior to the main weight-bearing area of the condyles.

Adult↗
PubMed1987

A histological study of human femoral condylar articular cartilage.

Paraffin sections cut both parallel to and perpendicular to the surface were used to study the histological structure of the articular cartilage of the lateral femoral condyle of infants, children and adults. Two main cell types were present--fusiform chondrocytes lying in swirling patterns were the predominant cell type of the cartilage up to and including two years, while a more rounded cell, randomly arranged, was commoner in the older specimens. Evidence suggests that these cells represent two distinct populations of chondrocyte, the round cells being derived from the earlier fusiform cells. Cartilage canals were a feature of the deeper regions of the presumptive articular cartilage in young specimens in which the epiphysis was still cartilaginous. The basophilic tidemark which marks the junction between the calcified and uncalcified cartilage in perpendicular sections was not seen in parallel sections. The calcified cartilage layer contained numerous processes of vascular bone which extended up from the subchondral bone and were a characteristic feature of the cartilage-bone interface. This layer of the articular cartilage cannot therefore be considered to be truly avascular.

Adult↗
PubMed1984

Intervertebral disc degeneration in adult mice with hereditary kyphoscoliosis.

Breeding experiments confirmed that a hereditary form of kyphoscoliosis in the BDL strain mouse was due to an autosomal recessive gene (ky). Sagittal sections of whole vertebral columns from adult homozygous recessive mice (ky/ky) were examined histologically. All mice showed varying degrees of degenerative change in one or more intervertebral discs between the fifth cervical and the second thoracic vertebrae. The changes comprised loss of cells, loss of distinction between nucleus pulposus and annulus fibrosus, loss of characteristic ring-like structure in the annulus, and development of wedge-shaped discs. In most animals, degenerative disc substance protruded from the disc space, usually posteriorly, sometimes anteriorly, and occasionally through the vertebral end plate cartilage. Posterior protrusions impinged on the spinal cord.

Animals↗