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Biomedical subjects

P Armati-Gulson

Publications and source records attributed to P Armati-Gulson.

5 recordsLinked to original sources
PubMed1988

Osteogenesis by canine and rabbit bone marrow in diffusion chambers.

Osteogenic activity of canine and rabbit bone marrow and marrow stromal fibroblasts (MSF) derived from marrow cultured in vitro was evaluated using diffusion chambers. Marrow from young dogs and rabbits grown in cell culture produced confluent layers of MSF. Diffusion chambers containing 0.18-7.6 x 10(6) allogeneic MSF were inserted into the peritoneal cavities of 5 dogs and 6 rabbits. Chambers recovered from the dogs (15/16) contained only loose fibrous tissue while chambers from rabbits (9/13) contained membranous bone and cartilage. Diffusion chambers implanted with 1.0-32.4 x 10(7) fresh allogeneic marrow cells suspended in cell culture medium were inserted into the peritoneal cavities of 11 dogs and 9 rabbits for 3-8 weeks, and after recovery examined histologically. Membranous bone was formed in 4/40 chambers containing canine marrow while bone and hyaline cartilage was formed in 21/27 chambers containing rabbit marrow. This apparent species difference in incidence of bone marrow osteogenesis may relate to a lower concentration of osteogenic precursor cells in canine marrow, a failure of osteogenic precursor cells to differentiate to osteoblasts in a somewhat artificial environment in vivo (viz diffusion chambers), a lack of cell-matrix interaction to stimulate cell differentiation, inappropriately short diffusion chamber implantation times post grafting, or a difference in ontogenetic stage of development of marrow donors with rabbit cells being physiologically younger.

Animals↗
PubMed1983

The development of adrenergic innervation in some human foetal blood vessels.

The development of adrenergic innervation was examined in saphenous and brachial veins, femoral, brachial and superficial temporal arteries from human foetuses of 7-19 weeks gestation. Fluorescence histochemical and electron microscopic techniques were used on transverse sections of the vessels. No specific adrenergic fluorescence was detected within any of the vessels before 11 weeks gestation, by which time the arteries showed specific adrenergic fluorescence. However, there was no evidence of adrenergic innervation of veins even at 19 weeks gestation. Incubation of the vessels with alpha-methylnoradrenaline did not lead to earlier detection of fluorescence. Electron microscopy showed that the adrenergic nerves found in the arteries were arranged as bundles of axons partially enclosed within Schwann cell processes, often lying close to capillaries in the outer regions of the tunica adventitia.

Adrenergic Fibers↗
PubMedDate not supplied

The effect of cell numbers on Schwann cell radioimmunoassay for serum cytotoxicity.

Immune cytotoxic effects on cultured Schwann cells can be monitored by a 51Cr release cytotoxicity assay. This paper presents the results of experiments using different cell numbers in the assay and a revision of the method for calculating the % specific release of 51Cr. The results give a more reliable and quantitative method for distinguishing between different sera.

Cell Count↗
PubMedDate not supplied

The development of human fetal dorsal root ganglia in vitro: the first 20 days.

Human fetal dorsal root ganglia aged from 8 to 12 weeks post-menstrual were grown in vitro for up to 20 days. Outgrowth of Schwann cells, axons and fibroblasts occurred after 4 h. By the 7th day in vitro Schwann cells enclosed bundles of axons and after 10 days some Schwann cells were seen to enclose individual axons. By the 20th day in vitro there was still a predominance of Schwann cells enclosing axonal bundles, but there were more individual axons ensheathed by three or four turns of Schwann cells. This arrangement mimics the early development in vivo of human dorsal root ganglia and provides the potential for an experimental system utilizing human nervous tissue rather than non-human animal models.

Axons↗