Biomedical subjects
Publications and source records attributed to B J Coventry.
An alternative approach to laparoscopic splenectomy is described. This technique uses a lateral position and modified port placement. Initial experience with three patients has demonstrated advantages over previously described approaches, by providing a more direct view of the splenic hilum and by eliminating the need for retraction of adjacent organs.
OBJECTIVES: To assess the degree to which limb-sparing surgery is implemented in patients with soft-tissue sarcoma, and its outcome. DESIGN AND SETTING: A detailed review of 40 patients who were all tertiary referrals to one surgeon, and general review of all 215 patients with sarcoma treated in South Australia between 1986 and 1992. INTERVENTIONS: Conservation of the limb by wide resection or marginal resection of soft tissue, combined when necessary with radiotherapy. Amputation was used when limb conservation failed or was not possible. MAIN OUTCOME MEASURES: Median survival time after treatment. RESULTS: Limb-sparing treatment was successful in 37 of the group of 40 patients. Thirty-two patients received adjuvant radiotherapy, and 19 received chemotherapy. Median survival time was 35 months. Review of all 215 patients with sarcoma revealed a higher initial amputation rate and a lower use of combined treatment methods than in our series. Twenty-six patients (65%) were initially incorrectly diagnosed before referral, resulting in a median delay in treatment of 16 weeks. CONCLUSIONS: The concept of limb-sparing surgery is well established, but is not yet as widely practised for limb sarcomas as it could be. Delay in diagnosis is a significant problem.
We have applied a technique which was originally used for cardiac transplantation in mice, to the transplantation of human breast cancers. To our knowledge previous reports of this method for tumour xenografting have not been made. This technique has wider application for many non-vascularised tissue allografts, including for example synovial grafts for arthritis research or other tumour types in oncology research. The method is simple and reproducible within the limits of the experiments reported.
Surface molecules present in low copy numbers can be detected with high-sensitivity fluorescence flow cytometry. Many cells previously thought not to express certain molecules on their surface can now be shown to have these molecules in very low copy numbers by high-sensitivity fluorescent cytometric methods. Detection of molecules by immunoperoxidase staining methods has not previously been compared with high-sensitivity flow cytometry techniques. Computerized video image analysis (VIA) is a method that allows measurement of area and density of the immunostain chromogen reaction product in a standardized fashion analogous to flow cytometry. In this study, we compared immunoperoxidase reaction products measured by VIA methods with high-sensitivity flow cytometric measurements for cells with 10,000 down to 50 antibody molecules bound to their surfaces. Detection of 100-200 surface molecules was possible with heavy metal-enhanced immunoperoxidase methods, whereas standard immunoperoxidase methods were not as sensitive. The sensitivity of the nickel-enhanced immunoperoxidase staining method was confirmed for detection of an epitope (Tac-IL2 receptor alpha-chain) present in low numbers on the surface of peripheral blood lymphocytes.
A rare case of pre B-lymphoblastic lymphoma of the testes and adrenal glands is presented. No lymph node, central nervous system or bone marrow involvement was demonstrated at diagnosis. The primary presentation was of acute unilateral pain and swelling, mimicking simple orchitis. The diagnosis was made using aspiration cytology and the lymphoma characterized using immunohistochemical, electron microscopic and karyotype analysis techniques. Pre B-cell markers were clearly demonstrated by all criteria used. Monoclonal antibodies (FMC 29 and FMC 31) were used to define the early B-cell nature of the lymphoma. Confirmation using karyotype analysis in addition to immunoglobulin and T-cell beta-receptor gene rearrangement was obtained. Intrathecal chemotherapy was used prophylactically. Combination chemotherapy produced regression of the primary lymphomatous lesions, but subsequent bone marrow spread led to death.
Two rare but life-threatening complications of percutaneous endoscopic gastrostomy (PEG) are reported: small bowel perforation and obstruction. Both resulted from impaction of the PEG end-piece after separation at skin level. Review of the literature revealed very few complications from intestinal passage of PEG end-pieces. The free intragastric PEG end-piece routinely passes through the gastrointestinal tract in most cases. One of these two cases was drawn from a series of 100 patients with intentional intestinal passage of PEG end-pieces to give a severe complication rate of 1%. A case can be made for routine endoscopic per-oral removal of PEG end-pieces in the elective setting, but this is more costly and not without hazard. Previous laparotomy and/or known adhesions is a relative indication for endoscopic retrieval of the PEG end-piece. Oesophageal disease or intolerance of endoscopy is a relative indication for intestinal passage. Close clinical follow up is recommended to ensure that the PEG end-piece has passed per-rectum. If the PEG end-piece has not passed and is shown in the small bowel on plain X-ray at approximately 3 weeks after separation then lodgement has probably occurred and early operative intervention is warranted.
CD1a molecules are expressed on dendritic cells (DC) during certain maturational phases coincident with the functions of antigen capture and processing. During these phases, CD1a is anchored to the cytoplasmic membrane through its cytoplasmic domain and the antigenic binding domain is projected from the cell surface. Membrane bound HLA Class I and II molecules are also expressed at relatively high levels on DC, but it is not known whether there is any interdependence between CD1 expression and that of the classical histocompatability molecules. Recent information concerning the structure, function and likely role of CD1 in presentation of hydrophobic lipid and carbohydrate antigens to the immune system is detailed. The potential relevance of the lipid presenting functions of CD1 molecules for the detection and recognition of tumour glycolipid antigens is hypothesised and discussed. CD1 a tumour infiltrating putative dendritic cells are discussed in terms of their density, separation, culture and possible function in breast cancers in the light of recent findings.