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Biomedical subjects

J Quinn

Publications and source records attributed to J Quinn.

At least 127 records · Page 7Linked to original sources

L-glutamine stimulates jejunal sodium and chloride absorption in pig rotavirus enteritis.

Rotavirus enteritis is the leading cause of diarrhea in infants worldwide. A research priority of the World Health Organization is to develop oral rehydration solutions containing amino acids or other additives that will stimulate intestinal absorption more efficiently than the current glucose-based oral rehydration solutions. Glutamine is the principal metabolic fuel of the small bowel and a putative stimulator of mucosal repair. This report describes the transport response to mucosal L-glutamine following intestinal injury caused by porcine rotavirus. Peak symptoms and mucosal damage were observed 2-7 days after oral rotavirus inoculation. In vitro transport studies of the maximally injured region, the midjejunum (80% reduction in lactase), surprisingly, showed transport responses to L-glutamine (30 mmol/L) and L-alanine (30 mmol/L) that were similar qualitatively and quantitatively to those observed in control tissue. Subsequent application of mucosal D-glucose (30 mmol/L) caused additional stimulation of electrogenic Na+ transport, but the response to glucose was blunted (P less than 0.05) in the infected tissues. Glutamine and alanine enhanced Na+ absorption to a similar degree (2-2.5 muEq.cm-2.h-1), but glutamine stimulated equal amounts of electrogenic and electroneutral NaCl absorption, whereas alanine had no significant effect on net Cl- flux. Glutamine is a potentially useful substrate for investigation in oral rehydration solutions for infant diarrhea.

Alanine↗

The surgical management of children with incompletely resected hepatic cancer is facilitated by intensive chemotherapy.

This prospective study was undertaken to evaluate the efficacy of continuous-infusion doxorubicin and cisplatin (CI-DOX/CPPD) for the treatment of children with incompletely resected hepatic cancer. Of the 46 evaluable patients, 32 had hepatoblastoma (70%) and 14 had hepatocellular carcinoma. Ten children had stage II tumors (microscopic residual), 25 were defined as stage III (gross residual), and 11 had distant metastasis (stage IV). Twelve patients underwent initial incomplete resection of their hepatic lesions and in the 34 others tumor biopsy specimens were obtained. Chemotherapy was administered and the majority of the children (70%) had an excellent clinical response with a decrease in both alpha-fetoprotein levels and measured tumor dimensions. The combination of CI-DOX/CPDD clearly facilitated surgical management, allowing for delayed hepatic resections in 20 of the 34 patients (59%) whose tumors were initially biopsied and considered to be unresectable. Overall survival in this study demonstrates a significant improvement in comparison to the historical controls. Twenty-one patients (46%) remain in complete clinical remission an average of 30 months following diagnosis (range, 17 to 40 months). The outcome of the children with hepatoblastoma was much better than those with hepatocellular carcinoma (63% v 17% survival). Survival of the 20 children who underwent delayed hepatic resections was not statistically different from the 12 patients whose hepatic tumors were removed at the initial laparotomy (41% v 58% survival). Although no obvious survival advantage was observed in those patients who underwent initial hepatic resections, there did appear to be an increased risk of postoperative complications in children whose tumors were resected following chemotherapy (8% v 25%).

Adolescent↗

Bone resorption by macrophage polykaryons of giant cell tumour of tendon sheath.

The antigenic phenotype, ultrastructure and bone resorbing ability of mononuclear and multinucleated giant cells of four giant cell tumour of tendon sheath (GCTTS) lesions was assessed. Both the giant cells and the mononuclear cells exhibited the antigenic phenotype of cells of the monocyte/macrophage lineage. The giant cells, unlike osteoclasts, did not respond morphologically to calcitonin and showed ultrastructural and immunophenotypic features of macrophage polykaryons. However, like osteoclasts, the giant cells showed direct evidence of resorption pit formation on bone slices. This indicates that the GCTTS is composed of cells of histiocytic differentiation with the giant and mononuclear cell components expressing a similar antigenic phenotype. Bone resorption by macrophage polykaryons shows that this is not a unique defining characteristic of osteoclasts. Qualitative differences in the degree and pattern of bone resorption by macrophage polykaryons distinguish it from that of osteoclasts and may underlie the clinical behaviour of osteolytic lesions.

Adult↗

Information requirements and sedation preferences of patients undergoing endoscopy of the upper gastrointestinal tract.

Patients' attitudes to sedation and their information needs before undergoing endoscopy were investigated using a questionnaire. One hundred and two patients completed the study; 32 had undergone endoscopy before. Sixty-six (94%) of the new patients and all follow-up patients knew why they were undergoing the procedure; 65 (93%) new and 28 (88%) follow-up patients understood how the procedure was carried out. Forty-one percent of the new and 25% of the follow-up patients wanted an information booklet about their disease and its management. Most patients chose to be sedated during the endoscopy. The proportion wishing to be sedated did not differ significantly between the new and follow-up patient groups. Sedation and information should be offered to all patients undergoing endoscopy.

Attitude to Health↗

Immunocytochemical analysis of human synovial lining cells: phenotypic relation to other marrow derived cells.

The antigenic phenotype of human synovial lining cells in normal and hyperplastic synovium intima was determined with a panel of monoclonal antibodies directed against a large number of well defined myeloid (macrophage/granulocyte associated) antigens. Synovial lining cells express numerous macrophage associated antigens, including CD11b (CR3), CD13, CD14, CD16 (FcRIII), CD18, CD32 (FcRII), CD45 (leucocyte common antigen), CD54 (ICAM-1), CD64 (FcRI), CD68, and CD71 (transferrin receptor). Few synovial lining cells expressed CD11a (LFA-1) and CD11c (p150,95). Subintimal macrophages expressed all the macrophage associated antigens which were present on synovial lining cells and, in addition, expressed CD15a, CD25 (interleukin-2 receptor), CD34, and CD35 (C3b receptor), none of which was present on synovial lining cells. Synovial lining cell expression of a wide range of macrophage antigens argues in favour of their marrow origin and membership of the mononuclear phagocyte system.

Aged↗

Use of monoclonal antibodies to recognise osteoclasts in routinely processed bone biopsy specimens.

In decalcified (5% nitric acid) and undecalcified (glycol-methacrylate or resin embedded) routinely processed bone specimens osteoclasts against resorbing surfaces were identified with monoclonal antibodies directed against leucocyte common antigen (LCA) (PD7/26, 2B11), CD68 (KP1), and gpIIIa (Y2/51) but not against HLA-DR (CR3/43 and Ta11B5). Mononuclear cells on resorbing surfaces and occasional mononuclear cells against or near resting surfaces showed a similar pattern of reactivity. This study shows that immunohistochemistry is a sensitive and useful technique for identifying osteoclasts in routinely processed bone specimens. It also suggests a role for mononuclear cells (possibly pre-osteoclasts) in bone resorption.

Antibodies, Monoclonal↗