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Biomedical subjects

J Quinn

Publications and source records attributed to J Quinn.

At least 163 records · Page 9Linked to original sources
PubMed1989

Ultrasound fetal femur length measurement in the screening for Down's syndrome.

The fetal femur length determined by an ultrasound examination at between 13 and 39 weeks gestation in 83 pregnancies associated with Down's syndrome was statistically significantly less than the expected value for pregnancies with the same biparietal diameter examined in the same ultrasound department (P less than 0.0001). Expected values were based on linear regressions of femur length on biparietal diameter in 1340 control pregnancies from 27 ultrasound departments. The median value for the affected pregnancies was 0.94 times the expected value (95% CI 0.92 to 0.97). Eleven per cent of affected and 1.4% of control pregnancies had values less than or equal to 0.85 times the expected. The reduction in femur length in affected pregnancies was not related to biparietal diameter or to maternal age. Fetal femur length may be useful as an ancillary screening variable in the antenatal screening for Down's syndrome.

Down Syndrome↗
PubMed1989

DR. A.C. Guyton: Builder.

Dr. Arthur C. Guyton will retire in September from his post as chairman of physiology and biophysics at the University of Mississippi Medical Center. Mississippians will mark the occasion by paying tribute to his life's work on Arthur Guyton Day, August 25. The event is described as a "celebration of science," because the man being honored "is one of the true luminaries of 20th century science."

History, 20th Century↗
PubMed1988

The immunohistology of synovial lining cells in normal and inflamed synovium.

The immunohistology of synovial lining cells (SLCs) in normal and inflamed hyperplastic synovium was investigated using monoclonal antibodies directed against leucocyte common antigen (LCA) HLA-DR and other macrophage components. We found that some SLCs in normal synovium express LCA, HLA-DR, and monocyte/macrophage-associated antigens. The number of SLCs expressing these antigens is increased in hyperplastic osteoarthritic (OA) and rheumatoid (RA) synovium. Some SLCs which did not react for LCA or other macrophage markers but were positive for HLA-DR were also noted in normal synovium and some segments of hyperplastic OA synovium. SLCs which are positive for LCA, HLA-DR, and macrophage markers contribute to the intimal hyperplasia in RA where they account for the majority of SLCs in the synovial intima. In OA synovium, the distribution of SLCs showing this pattern of reactivity was less uniform with numerous SLCs which were positive for HLA-DR but negative for LCA and other macrophage markers also present in the synovial intima. These findings indicate that there are some SLCs of bone marrow origin in normal and hyperplastic synovium. They also suggest that recruitment of SLCs of marrow origin is important in the production of intimal hyperplasia in both RA and OA and that there is also a significant local proliferation of non-marrow derived SLCs in OA.

Adult↗
PubMed1988

An anatomical study of cholinergic innervation in rat cerebral cortex.

The cholinergic innervation of rat cerebral cortex was studied by immunohistochemical localization of choline acetyltransferase. Stained bipolar cells, fibers and terminals were found in all areas of cortex. The density of cholinergic terminals was similar in all cortical areas with the exception of entorhinal and olfactory cortex, which showed a marked increase in the number of stained terminals. A laminar distribution of cholinergic terminals was found in many cortical areas. In motor and most sensory areas, terminal density was high in layer 1 and upper layer 5, and lowest in layer 4. Visual cortex, in contrast to other cortical areas, was characterized by a dense band of innervation in layer 4. It has been known that the majority of cortical cholinergic structures derive from a projection to cortex from large, multipolar neurons in the basal forebrain, which stain heavily for choline acetyltransferase. In this study, stained fibers were observed to take three different pathways from basal forebrain to cortex. The first, confined to medial aspects of forebrain and cortex, was observed to originate in the septal area, from where fibers formed a discrete bundle, swinging forward around the rostral end of the corpus callosum, then travelling caudally in the cingulate bundle. The second was found to consist of fibers fanning out laterally from the area of the globus pallidus, travelling through the caudate, then continuing for various distances in the corpus callosum before finally turning into the cortex. A third pathway appeared to innervate olfactory and entorhinal cortex. Ibotenic acid injections were made in the area of the globus pallidus to study the effect of lesioning the lateral pathway on the cholinergic innervation in cortex. A major loss of choline acetyltransferase positive terminals was observed in neocortex, but retrosplenial, cingulate, entorhinal and olfactory cortex showed a normal density of cholinergic innervation. The borders separating areas with lesioned cholinergic input from non-lesioned areas were precise. The distribution of stained terminals remaining in cortical areas with lesioned basal forebrain innervation suggests that the basal forebrain projection to cerebral cortex, and not the intrinsic cortical cholinergic neurons, give rise to the laminar distribution of cholinergic terminals observed in normal cortex. To compare the relative densities of different cholinergic cortical systems, the distribution of choline acetyltransferase staining was compared with that of vasoactive intestinal polypeptide and substance P, which are co-localized in some choline acetyltransferase-positive neurons innervating cortex.

Animals↗
PubMed1988

Immunohistology of rheumatoid nodules and rheumatoid synovium.

The immunohistological features of rheumatoid nodules and rheumatoid synovium were examined using monoclonal and polyclonal antibodies raised against macrophages, HLA-DR, leucocyte common antigen, and immunoglobulin components. The palisading cells surrounding the necrotic centre of the rheumatoid nodule were shown to be HLA-DR positive leucocytes, mostly histiocytes. The inflammatory infiltrate associated with rheumatoid nodules showed many immunohistochemical similarities to that of rheumatoid synovium, including a preponderance of IgG positive plasma cells, and a similar number and microanatomical pattern of distribution of HLA-DR positive cells. The significance of these findings for the cellular immunopathology and aetiology of the rheumatoid lesion is discussed.

Antigens, Differentiation↗
PubMed1988

Localization of platelet antigens and fibrinogen on osteoclasts.

The antigenic phenotype of the human osteoclast, which is known to be derived from a circulating mononuclear precursor cell of haemopoietic origin, is controversial. Recent studies have shown that macrophage as well as megakaryocyte/platelet antigens are expressed by osteoclasts. In this study, we have sought to define, by immunohistochemistry, the nature and possible function of platelet antigens expressed by human osteoclasts in foetal and adult bone specimens. Monoclonal antibodies to platelet glycoprotein IIIa (gpIIIa) and CD9 antibodies stained osteoclasts in all bone specimens examined. Fibrinogen was also localized to the osteoclast membrane in foetal bone imprints. In addition, we found that CD9 and gpIIIa antibodies reacted weakly with monocytes in buffy coat smears. Antibodies to factor 8 and glycoproteins Ib and IIb/IIIa did not react with osteoclasts. These results show that osteoclasts, monocytes, macrophages, megakaryocytes and platelets possess common antigens and that fibrinogen is present on the surface of osteoclasts. By analogy with platelets, CD9 and gpIIIa may play a role in fibrinogen binding by osteoclasts. Possible mechanisms by which platelet antigens and fibrinogen binding could affect osteoclast function are proposed.

Antibodies, Monoclonal↗
PubMed1988

Immunocytochemical analysis of the human osteoclast: phenotypic relationship to other marrow-derived cells.

The immunocytochemistry of the osteoclast, which is known to be derived from a circulating mononuclear precursor cell of bone marrow origin, is controversial. In this study, we have determined the antigenic phenotype of human osteoclasts in fetal and adult (Paget's disease, giant cell tumour of bone) specimens using a large number of monoclonal antibodies which react with granulocytes and mononuclear phagocytes. We have identified antibodies which reacted with human osteoclasts including CD13, CD15 and several groups of anti-macrophage antibodies. All the antibodies which reacted with osteoclasts are also known to react with monocytes or macrophages. Other marrow elements such as granulocytes, megakaryocytes and platelets were also commonly stained. Expression of myeloid and platelet antigens on osteoclasts shows that they are phenotypically related to these cells and is in keeping with the origin of osteoclast precursors from the pluripotential haemopoietic stem cell. Only a proportion of osteoclasts in fetal bone preparations were stained by CD15 antibodies, suggesting that subsets or different populations of osteoclasts, which can be identified by monoclonal antibodies, may be present in bone.

Adult↗