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Biomedical subjects

J P O'Brien

Publications and source records attributed to J P O'Brien.

At least 145 records · Page 8Linked to original sources
PubMed1981

Vascular compression of the duodenum (cast syndrome) associated with the treatment of spinal deformities. A report of six cases.

Vascular compression of the duodenum, the so-called cast syndrome, which is due to the mechanical compression of the third part of the duodenum from the superior mesenteric artery, was developed postoperatively in six patients treated for their spine deformities. The early recognition of the clinical signs of the obstructive ileus and the proper conservative treatment proved efficient for five of the patients, and only in one laparotomy and duodeno-jejunostomy were inevitable due to the severity and persistency of the symptoms. The purpose of this report is to record these cases describing the clinical manifestations, the treatment, and the pathogenesis of the vascular compression of the duodenum which may occur during the treatment of the spine deformities.

Adolescent↗
PubMed1981

Immunofluorescent staining for collagen and proteoglycan in normal and scoliotic intervertebral discs.

Specific antisera to collagen Types I, II and III and proteoglycan were used to investigate the distributions of these molecules in normal human intervertebral discs. Immunofluorescent staining indicated the presence of small amounts of Type III collagen located pericellularly in normal adult intervertebral discs. This finding had not been demonstrated previously by other methods. Similar specimens of intervertebral discs from 17 patients with scoliosis of varying aetiologies were examined, but no evidence was obtained for primary connective tissue defects. Secondary changes, especially marked vascularisation of the inner annulus, were apparent in a number of scoliotic discs, and some of these showed enhanced staining for collagen Type I and proteoglycan, and intercellular matrix staining for Type III collagen.

Adolescent↗
PubMed1981

Alterations in vertebral growth following prolonged plaster immobilisation.

Long-term immobilisation in serial plasters for scoliosis, including the period of the adolescent growth spurt, leads to an increase in height of the vertebral bodies and a decrease of their height to width ratio. These changes are at the expense of the disc which is reduced in thickness. This stimulating effect on the vertebral body growth is probably due to the changes in mechanical factors.

Adolescent↗
PubMed1981

The role of actinically provoked systemic elastolysis in polymyalgic vascular disease. A study based on serum fluorescence and haptoglobin.

This study of cutaneous elastic tissue and serum fluorescence supports the hypothesis that widespread destruction and resorption of elastic tissue (elastolysis) occurs in the temporal arteritis/polymyalgia rheumatica syndrome. A systemic elastolysis of this nature may be provoked by actinic (radiant) damage to the "exposed" elastic tissues in the skin and superficial arteries, the archetype of such injury being seen in temporal arteritis. Scattered giant cells are the usual agents of elastolysis but tuberculoid ("sarcoid") infiltrates often take over in the later stages. In acute polymyalgia, the phenomenon probably becomes diffuse and humoral. Elastolysis may be a direct pathogenetic link between polymyalgia and other vascular diseases such as idiopathic aneurysm and atherosclerosis.

Blood Protein Electrophoresis↗
PubMed1980

The neuropathology of intervertebral discs removed for low-back pain.

Thirty lower lumbar intervertebral discs (IVDs) removed for low-back pain were examined. There is a profuse non-myelinated axonal network and abundant free nerve terminals in the outer (lateral) half of the annulus fibrosus. The inner annulus and the nucleus pulposus did not contain nerve terminals. No significant changes in the nerve networks could be demonstrated in degenerate IVDs: in particular, ingrowth of nerve terminals into foci of granulomatous tissue was not seen. Early foci of degeneration are clearly shown by Marshall's silver method for metalophil cells. Mucinous filaments are argyrophilic and can be mistaken for axonal structures in the nucleus pulposus.

Back Pain↗
PubMed1980

Rat dendritic cells function as accessory cells and control the production of a soluble factor required for mitogenic responses of T lymphocytes.

Transformation of T lymphocytes, induced by treatment with periodate or with neuraminidase plus galactose oxidase, requires the participation of accessory cells. Procedures were developed for the fractionation of rat lymph node cells, by which most of the lymphocytes can be recovered as a major population of cells that do not respond to mitogenic stimulation unless accessory cells from a separated minor population are added. Further purification led to a 1000-fold overall increase in accessory activity per cell, with a 50-70% yield. The purest preparations were virtually free of macrophages and contained more than 90% typical dendritic cells. Maximum responses occurred at a ratio of only one dendritic cell per 200 periodate-treated lymphocytes. This evidence thus indicates strongly that in rats, dendritic cells--not macrophages--function as accessory cells. Further, the number of dendritic cells in a preparation governed the magnitude of the mitogenic response and was limiting in the case of unfractionated lymph node cells. In addition, when oxidized with periodate or with neuraminidase plus galactose oxidase, the dendritic cell served as a very potent indirect stimulator of untreated responder lymphocytes. Both functions of the dendritic cell appeared to lack species specificity, since mouse dendritic cells were very active when tested with rat responder lymphocytes. A soluble factor (accessory cell-replacing factor), produced by cultures of lymph node or spleen cells subjected to oxidative mitogenesis, enabled otherwise unresponsive mitogen-treated lymphocytes to respond. Dendritic cells were required for the production of this factor but may not be solely responsible for its production.

Adhesiveness↗
PubMed1980

Scoliosis in symptomatic spondylolisthesis.

The association between spondylolisthesis and scoliosis was studied in 84 patients who presented during a 30-year period with symptomatic spondylolisthesis. The incidence of scoliosis was 42 per cent, the majority of cases being lumbar or thoracolumbar curves of less than 15 degrees. The incidence was highest in the group of patients with spondylolisthesis at L4--5 where all except one had scoliosis. Scoliosis was present in 47 per cent of patients with dysplastic spondylolisthesis at the lumbosacral junction; in this group, the incidence of scoliosis was greater where the displacement exceeded 25 per cent. The lowest incidence (25 per cent) was found in the group with isthmic spondylolisthesis at the lumbosacral junction. There appeared to be no relationship between excessive lumbar lordosis or tightness of the hamstrings and scoliosis.

Adolescent↗