Biomedical subjects

G R Bushell

Publications and source records attributed to G R Bushell.

22 records · Page 2Linked to original sources

PubMedDate not supplied

Collagens, elastin and noncollagenous protein of the intervertebral disk.

This is a review of the recent developments in collagens, elastin, and noncollagenous protein of the normal and abnormal intervertebral disk. Much progress has been made on the chemistry of the normal disk constituents. However, little work has been done to date on the essential lesion of the early degenerative disk in humans; a major effort in this field is indicated in the next decade. The reasons are obvious, for in the unraveling of the etiology of degeneration of the intervertebral disk lies the hope and expectation of prevention of disk failure.

Chemical Phenomena↗

PubMedDate not supplied

Biomechanics and biochemistry of the intervertebral disks: the need for correlation studies.

The literature on the biomechanics of the intervertebral disk is reviewed with emphasis on biomechanical--biochemical--morphological correlative studies. The deficiency of definitive correlative studies is apparent and an appeal is made to interested investigators to fill in the voids in this extremely important area of study. A comprehensive theory of intervertebral disk failure awaits application of existing biomechanical, biochemical and morphological techniques in a detailed and methodical manner to the normal and early degenerative human intervertebral disks.

Animals↗

PubMedDate not supplied

Distribution of glycosaminoglycans across the normal and the scoliotic disc.

This paper reports on our investigations of the glycosaminoglycans (GAGs) (hyaluronic acid, chondroitin-6-sulfate, and keratan sulfate) of 13 adjacent zones of normal and scoliotic discs obtained at necropsy. The isolation and separation of these GAGs on the microgram scale was achieved using the different solubilities of the calcium and cetyl pyridinium chloride complexes. In normal discs the distribution of these GAGs is symmetric about the nucleus pulposus where their concentration is highest, and lowest in the outer annulus regions. A shift in this distribution profile was observed for the GAGs of the scoliotic discs, particularly at the apex of the curve. On the concave side of this disc the chondroitin-6-sulfate was elevated relative to discs at a lower level. In those annulus zones on the convex side of the curve, the keratan sulfate and hyaluronic acid levels were elevated and chondroitin sulfate depressed. These results suggest the presence in these respective regions of at least two different species of proteoglycans accompanied by elevated hyaluronate levels.

Adolescent↗

PubMedDate not supplied

Changes in the cytoplasmic elements of cultured cells infected with Eimeria vermiformis sporozoites.

Epithelial-type (PK-15) and fibroblast-type (MDBK) mammalian cell cultures were inoculated with purified Eimeria vermiformis sporozoites. Matched samples from 0 to 93 h after inoculation (HAI) were processed for electron microscopy; half of the sample preparations were extracted with non-ionic detergent prior to fixation. Specimens were examined by both transmission and scanning electron microscopy. Numerous sporozoites were attached to the cultured cells from 2 to 93 HAI, usually near the cell periphery. Some host cell microvilli extended up and appeared attached to the sporozoites. Sporozoites fixed during the penetration process were markedly constricted at the site of entry; however, no noticeable changes occurred in the host cell membrane or surface microvilli during sporozoite invasion or in sporozoite-infected cells. In cells extracted with 1% Triton X-100, the host cytoskeleton was progressively reorganized about the parasites but changes were limited to the immediate area of the sporozoite. Around resident sporozoites, the cytoskeleton became less dense but also more ordered, which contrasted with adjacent cell areas. Cytoskeletal elements passed both over and under the parasites. The appearance of the cytoskeleton suggested that the host cell formed a loose, basket-like net of cytoskeletal elements about the parasite.

Animals↗