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Biomedical subjects

J Quinn

Publications and source records attributed to J Quinn.

At least 145 records · Page 8Linked to original sources
PubMed1990

New sites of cellular vitronectin receptor immunoreactivity detected with osteoclast-reacting monoclonal antibodies 13C2 and 23C6.

The immunohistochemical profile of osteoclast-reacting monoclonal antibodies, 13C2 and 23C6, known to detect the alpha-chain of the vitronectin receptor, is described. Both antibodies reacted with several cell types apart from osteoclasts including megakaryocytes, smooth muscle cells, endothelial cells, thyroid follicular epithelium, renal glomeruli and tubular epithelium, myoepithelial and epithelial cells in the breast and prostate, and both cytotrophoblast and syncytiotrophoblast. In addition, macrophage polykaryons, synovial lining cells, a small number of mononuclear cells in buffy coats, and a few macrophage-like cells in the stroma of various tissues were also stained. The epitopes recognized by these antibodies are thus not osteoclast-specific and are present on other cells of the mononuclear phagocyte system. The implications of these results for osteoclast ontogeny, the nature of the antigens described and the question of osteoclast-specific antibodies are discussed.

Antibodies, Monoclonal↗
PubMed1990

Origin of marrow stromal cells and haemopoietic chimaerism following bone marrow transplantation determined by in situ hybridisation.

The origin and cell lineage of stromal cells in the bone marrow is uncertain. Whether a common stem cell exists for both haemopoietic and stromal cells or whether these cell lines arise from distinct stem cells is unknown. Using in situ hybridisation for detection of the Y chromosome, we have examined histological sections of bone marrow from seven patients who received marrow transplants from HLA-matched donors of the opposite sex. Stromal cells (adipocytes, fibroblasts, endothelial cells, osteoblasts and osteocytes) were identified in these recipients as being of host origin. This result is consistent with the concept of a distinct origin and separate cell lineage for cells of the haemopoietic and stromal systems. It also shows that engraftment of marrow stromal cell precursors does not occur and that host stromal cells survive conditioning regimens for marrow transplantation. With the exception of one case, with a markedly hypocellular marrow, mixed chimaerism was seen in haemopoietic cells, indicating that this is not a rare event after marrow transplantation.

Adolescent↗
PubMed1990

The effects of submaximal endurance exercise upon LH pulsatility.

The acute effects of submaximal endurance exercise (three consecutive 20-min runs on a treadmill at 50, 60 and 70% of the subjects' maximum oxygen uptake) upon the pulsatile release of LH were compared with those accompanying leisurely strolling for a similar period in seven normally menstruating young women. All trials were conducted during the early to mid-luteal phase, as determined by body temperature patterns, ultrasonic scans of the ovaries, detection of the LH surge in first morning urine specimens, and serial measurements of plasma progesterone. Blood was sampled every 10 min via an indwelling cannula for 8 h before and 12 h after exercise and serum LH measured by radioimmunoassay. LH pulsations were analysed by a time series method. Following cannulation, mean LH levels declined but then rose to reach a maximum 2 h before the beginning of the exercise bout. LH concentrations remained virtually unchanged during exercise itself, and exhibited a declining trend throughout the post-exercise period. The findings in the two groups were similar in all respects, except that in the control study the rate of LH pulsatility was significantly diminished (P less than 0.05) during the first 2 h of sampling as compared with the subsequent 2-h period. The approximate half-life of LH varied from 27 to 57 min, with a mean of 41 min.

Adult↗
PubMed1990

Immunophenotypic differences between osteoclasts and macrophage polykaryons: immunohistological distinction and implications for osteoclast ontogeny and function.

The antigenic phenotype of human fetal osteoclasts was compared with that of human tissue macrophages and macrophage polykaryons in foreign body lesions using a large number of monoclonal antibodies directed against myeloid (granulocyte/mononuclear phagocyte) antigens. Osteoclasts expressed a restricted range of macrophage-associated antigens including CD13, CD15A, CD44, CD45, CD54, (ICAM-1), CD71 (transferrin receptor), and CD68. These antigens were also present on macrophages and macrophage polykaryons both of which also strongly expressed CD11a,b,c, CD18, (LFA family), CD14, CD31, CD36, CD37, CD39 and CD43 antigens. There was also weak and occasional expression of CD16 (FcRIII), CD25 (interleukin 2 receptor), CD32 (FcRII), CD35 (C3b receptor) and HLA-DR by macrophage polykaryons. The presence of some macrophage associated antigens on osteoclasts is consistent with their originating from cells of the mononuclear phagocyte system. The numerous differences in antigenic phenotype between osteoclasts and macrophage polykaryons, however, suggest that their pathways of development and differentiation are not identical. The differences discerned in antigenic phenotype should also permit distinction between these polykaryons (and possibly their mononuclear precursors) in normal and diseased tissues.

Antibodies, Monoclonal↗
PubMed1990

Development of L-glutamine-stimulated electroneutral sodium absorption in piglet jejunum.

Glutamine is the primary metabolic fuel of the small intestine. To determine the effects of glutamine on intestinal electrolyte transport, piglet (3 days to 3 wk old) jejunum was bathed in Ussing chambers in a buffer containing 10 mM serosal glucose, and the effects of different concentrations of mucosal L-glutamine and D-glucose on short-circuit current and transmucosal Na+ and Cl- transport were measured. Resting jejunum secreted Na+ and Cl- in an electrogenic manner. In contrast to mucosal D-glucose (30 mM), which promoted electrogenic Na+ absorption (1.8 mueq.cm-2.h-1), mucosal L-glutamine (30 mM) stimulated both Na+ (2.7 mueq.cm-2.h-1) and Cl- (2.2 mueq.cm-2.h-1) absorption. This NaCl-absorptive jejunal response depended on the presence of both Na+ and Cl-, did not appear until animals were greater than 7 days of age, and was not observed with glucose, phenylalanine, or mannitol. Serosal, as well as mucosal, glutamine (30 mM) promoted electroneutral NaCl absorption. A small electrogenic Na(+)-absorptive response to L-glutamine was also observed. The effect of L-glutamine on jejunal NaCl transport resembles that of other metabolic fuels on colonic transport; its mechanism remains to be determined. We conclude that glutamine promotes electroneutral salt absorption in the small intestine.

Aging↗
PubMed1989

Ciguatera and mannitol: experience with a new treatment regimen.

Ciguatera is a distressing, hitherto-untreatable and not rare disease which results from the eating of ciguatoxin-contaminated fish from tropical and subtropical waters. We report here the results of a pilot study to assess the efficacy of mannitol therapy in ciguatera poisoning. Twelve adult patients (six men) have been treated, five of whom--who were ill acutely--experienced a significant benefit from this therapy, in three cases, with a hitherto-unexperienced dramatic reversal of symptoms. We conclude that an intravenous infusion of 1.0 g/kg of mannitol which is given over 45 minutes, after rehydration if required, can be of significant benefit to at least some acutely intoxicated victims. We postulate either a reduction of axonal oedema, or a scavenger effect, or both, as the mechanism of the beneficial effects of mannitol. Ciguatoxin is rich in hydroxyl groups, and causes microscopic oedema of neural tissue. If our conclusion of the beneficial effects of mannitol therapy is confirmed, this will offer the first effective therapy for acute phases of this disease, and has promise of preventing much long-term morbidity.

Acute Disease↗
PubMed1989

Long-term pulmonary sequelae of meconium aspiration syndrome.

To determine the incidence of long-term sequelae after meconium aspiration syndrome (MAS), we studied 11 children who had MAS at age 8.2 +/- 0.2 years (mean +/- SD) and nine healthy control subjects with pulmonary function and exercise stress tests. The MAS children had evidence of mild airway obstruction, hyperinflation, and increased closing volumes in comparison with control values. During graded exercise stress tests on a treadmill, MAS children achieved normal maximal oxygen consumption and anaerobic threshold without a significant fall in arterial oxygen saturation or increase in CO2 tension. Exercise-induced bronchospasm occurred in four (36%) MAS subjects but in none of the control subjects. We conclude that children surviving MAS have long-term pulmonary sequelae, including airway obstruction, hyperinflation, elevated closing volumes, and airway hyperreactivity; yet they achieve normal aerobic capacity. These findings are similar, although less severe, than those after prematurity and bronchopulmonary dysplasia.

Airway Obstruction↗
PubMed1989

The origin and nature of stromal osteoclast-like multinucleated giant cells in breast carcinoma: implications for tumour osteolysis and macrophage biology.

The origin and nature of osteoclast-like multinucleated giant cells (OMGCs), in extraskeletal neoplasms, is uncertain. The ultrastructure, antigenic phenotype and function of OMGCsm in a breast carcinoma were studied in order to clarify the relationship between OMGCs, osteoclasts and other cells of the mononuclear phagocyte system (MPS). OMGCs resorbed cortical bone in a manner similar to osteoclasts. However, unlike osteoclasts, OMGCs did not possess a ruffled border or clear zone, and expressed HLA-DR and Fc receptors and CD14, CD16, CD18 and CD11 (p150,95) antigens. In addition, OMGCs failed to respond morphologically to calcitonin and were directly stimulated by parathyroid hormone (PTH) to increase bone resorption. These findings suggest that OMGCs are a specific type of macrophage polykaryon distinct from both osteoclasts and other types of inflammatory polykaryon. Occasional smaller (20-25 microns) macrophage-like cells were also associated with resorption pits. Bone resorption by OMGCs isolated from the breast indicates that a cell of the MPS can be transplanted to a new tissue location and perform a highly specialised function appropriate to an MPS cell of that tissue (i.e. the osteoclast). PTH stimulation of bone resorption by OMGCs suggests that PTH or a PTH-like protein, may be involved in the bone resorption and consequent hypercalcaemia associated with metastatic breast cancer.

Antigens, Differentiation↗