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Biomedical subjects

J A Stevenson

Publications and source records attributed to J A Stevenson.

At least 37 records · Page 2Linked to original sources
PubMed1982

A crossed parabigemino-lateral geniculate projection in rats blinded at birth.

Anatomical techniques are used to demonstrate a projection from the parabigeminal nucleus (PBG) to the contralateral dorsal lateral geniculate nucleus (dLGN) in adult pigmented rats which had been bilaterally enucleated at birth. No similar pathway is detected in normal animals. Ultrastructural examination of degeneration in dLGN of blinded rats after contralateral PBG lesion reveals a similarity of the PBG terminals to "replacement terminals" seen in dLGN of anophthalmic or neonatally enucleated mice (Cullen and Kaiserman-Abramof 1976).

Animals↗
PubMed1982

Thrombotic microangiopathy: recurrence following renal transplant and response to plasma infusion.

Recurrence of thrombotic microangiopathy (TMA) has rarely been reported following renal transplantation. We describe a 24-year-old man who developed irreversible renal failure due to thrombotic microangiopathy. Following renal transplantation, he developed recurrent episodes of microangiopathic hemolysis; during one of these episodes a biopsy revealed the development of thrombotic microangiopathy in the graft. In each of five recurrences to date, plasma infusion, either alone or combined with other forms of therapy, has produced a prompt remission. This is the first report, to our knowledge, of the successful treatment of recurrent TMA in a renal transplant recipient.

Adult↗
PubMed1982

Henoch-Schönlein purpura: simultaneous demonstration of IgA deposits in involved skin, intestine, and kidney.

Recent reports indicate that circulating IgA immune complexes may play a primary role in the pathogenesis of Henoch-Schönlein vasculitis and are responsible for the granular deposits of IgA seen in biopsy specimens of skin and kidney. A patient had classic Henoch Schönlein syndrome, including hematuria, purpura, and abdominal pain; tissue taken simultaneously from the small intestine, skin, and kidney was examined by light immunofluorescent, and electron microscopy. Granular deposits of IgA were found in small-vessel walls of the intestinal tissue and skin, and in the glomerular mesangium. This provides further support for the notion that IgA deposits produce tissue injury in intestine, skin, and kidney in Henoch-Schönlein syndrome.

Adult↗
PubMed1981

Mitosis of radial glial cells in the optic tectum of adult goldfish.

A class of tectal cells whose mitotic activity is enhanced by optic nerve regeneration in adult goldfish has been identified as radial neuroglia. These mitotic glial cells are morphologically distinct cells with prominent radial processes which extend through the entire depth of the tectal layers. The radial glia incorporate exogenous [3H]thymidine ([3H]TdR) into DNA as early as 2 hr after systemic injection. The plane of cell division for the mitotic radial glia is always aligned to the equator of the cell body, perpendicular to the direction of the radial process. In a few cases, radially adjacent pairs of labeled daughter radial glial cells are observed as early as 12 hr and also as late as 51 days after [3H]TdR injection. In other cases, however, only one labeled daughter radial glial cell is identified, and the other daughter cell cannot be traced. These observations suggest that radial glial cells of the adult goldfish tectum can be induced (presumably by mitogenic effects of regenerating optic nerve fibers) to undergo mitosis.

Animals↗
PubMed1980

Kinetics of cell proliferation in the halved tectum of adult goldfish.

The time course of post-operative cell proliferation was studied in the halved optic tectum of adult goldfish using autoradiographic methods. At varying intervals after bilateral optic nerve crush and unilateral lesion of the caudal hemitectum, fish were injected with [3H]thymidine and allowed to survive for designated times before sacrifice. Comparisons of labeled cell numbers in different laminar regions on the intact and operated sides of the tecta were made. When short post-injection survival times were employed, there was a bimodal increase in proliferation on both tectal sides with increases occurring by 5 and between 20 and 35 days after surgery (dpo). More labeled cells were seen on the lesioned side in the outer tectal zone in fish injected at 25 and 35 dpo. Within their inner tectal zones these same fish showed more labeled cells in the periependymal layer on the lesioned side. With extended post-injection survival there was a general decline in numbers of labeled cells on both tectal sides. The only labeled cells which persisted in force were those of the periependymal layer; equal numbers were seen on both operated and intact sides. On the basis of these observations we conclude that the cell proliferation which occurs in this situation may be attributed primarily to the effects of optic nerve regeneration; the tectal surgery per se does not induce massive cell proliferation which might numerically reconstitute the halved tectum.

Animals↗