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Biomedical subjects

J C Edwards

Publications and source records attributed to J C Edwards.

At least 127 records · Page 7Linked to original sources
PubMed1990

Enhanced detection systems for enzyme-linked heterogeneous immunoassays: luminescence.

The use of luminescence detection as the endpoint for enzyme immunoassays offers the sensitivity and performance that had previously been obtained only with radioactive immunoassays. For systems that are optimized to give a continuous output of light, simple and convenient processing of tests can be achieved without the need for accurate timing of the signal generation. The applicability of these techniques for the analysis of a wide range of substances should lead to their establishment in cancer diagnosis as well as in other fields.

Biomarkers, Tumor↗
PubMed1990

Antigen-induced arthritis in the rabbit: ultrastructural changes at the chondrosynovial junction.

Structural changes at the chondrosynovial junction of the lateral border of the lateral femoral condyle have been studied by electron microscopy in rabbits with antigen-induced arthritis of 6 h-27 days duration. Rapid changes in the collagen fibrils of the extracellular matrix in the synovial lining and articular cartilage were noted. Collagen fibrils with unusually large diameters were observed. Overgrowth of cartilage by inflamed synovium was seen within 3-6 days of induction of arthritis and by day 12 the interface between these two tissues was largely indistinguishable. The synovial pannus at this time was fibrotic and infiltrated with plasma cells, lymphocytes and macrophages. Few polymorphonuclear leucocytes were found in the developing pannus. Macrophages were found with extended processes which enveloped neighbouring cells. Some blood vessels had thickened endothelial cells though lymphocytes were not observed in their vicinity. This study reveals the rapidity with which synovial pannus can develop and suggests that there are a number of mechanisms operating to cause cartilage breakdown in antigen-induced arthritis.

Animals↗
PubMed1989

Lymphocyte kinetics in a murine model of chronic inflammation.

A modification of the air pouch system [1], has been developed to investigate the role of lymphocytes in an inmmunologically driven model of chronic inflammation. Radiolabelled spleen and lymph node mononuclear cells from mice presensitised with Bordatella pertussis vaccine (BPV) were infused intravenously into mice also presensitised with BPV and challenged with BPV into 6 day old air pouches. Cell migration was monitored by gamma counting of tissues sampled 4 hours after infusion. The percentage increase in counts obtained in air pouch tissue compared to control skin, over a time course of 30 days, reached a peak at 10 days after BPV challenge. Vessels with features of high endothelial venules, and clusters of lymphocytes have been demonstrated histologically and immunohistochemically in air pouch tissue at this time.

Animals↗
PubMed1989

Fenestration of tenosynovial capillaries.

A proportion of superficial capillaries in joint synovium are known to be fenestrated. The specialized functions of these fenestrated capillaries are unknown. We report the finding of fenestrae in tenosynovial capillaries from rabbit peroneal tendon sheaths. Fenestrations occupied 0.66% of the endothelial surface. Fenestrated capillaries appear to be a general feature of synovium, rather than a specific feature of joint tissue.

Animals↗
PubMed1989

Two ways to assess problems of evaluating third- and fourth-year medical students: a case study.

Clinical faculty commonly acknowledge that they have difficulty evaluating third- and fourth-year medical students. The faculty and administration of the Louisiana State University (LSU) School of Medicine in New Orleans conducted pilot tests of two types of materials to assess these problems as part of the Clinical Evaluation Program undertaken by the Association of American Medical Colleges in 1984-1985. The two types of materials--questionnaires and the Problem-Case Analysis--were developed by the staff of the AAMC program and used by the LSU Department of Medicine and the Department of Obstetrics and Gynecology to identify problems in the process of evaluating clerks. Furthermore, the two methods proved complementary: both methods identified some of the same problems and each identified problems not identified by the other. Handling difficult students was the single problem identified by both methods in both departments. The questionnaires permit a simple method of collecting data about a broad range of problems. The Problem-Case Analysis, on the other hand, requires more time but evokes possible causes and alternative solutions, as well as identifying the problems. Improvement plans were developed by each department to address the problems that surfaced.

Education, Medical, Undergraduate↗
PubMed1989

Effect of indomethacin on swelling, lymphocyte influx, and cartilage proteoglycan depletion in experimental arthritis.

The effects of indomethacin on antigen induced arthritis in rabbits have been investigated. Arthritis was induced in the knee joints of sensitised rabbits by intra-articular injection of antigen. Swelling of the joints was measured for 14 days after antigen challenge, and groups of animals were killed on days 1, 7, or 14 for collection of synovial fluids and tissues. Indomethacin (1 mg/kg, three times daily) reduced joint swelling and the prostaglandin E2 concentrations in synovial fluid. In addition, indomethacin increased the loss of proteoglycan from articular cartilage and the numbers of lymphocytes in the inflamed synovial lining. These findings suggest that the symptomatic benefits of indomethacin and related drugs in inflammatory arthritis may be achieved at the expense of significant adverse effects on joint tissues.

Animals↗
PubMed1989

Isolation and culture of HCO3- -secreting intercalated cells.

Intercalated cells of the distal nephron secrete either H+ or HCO3-. We have succeeded in isolating HCO3- -secreting intercalated cells from the rabbit kidney. When seeded onto collagen-coated permeable supports, these cells form monolayers with a resistance of 595 +/- 75 omega.cm2. The monolayers maintain the characteristics of an epithelium, with apical microvillae and tight junctions. They display the same polarity as do HCO3- -secreting intercalated cells in vivo, namely apical peanut lectin binding and apical Cl- -HCO3- exchange. The monolayers are capable of transepithelial HCO3- transport via this exchanger. The rate of Cl- -dependent transepithelial HCO3- transport is 4 +/- 0.4 nmol.min-1.cm-2. Transepithelial HCO3- transport is completely abolished by 50 microM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid applied to the apical side of the monolayer. These cultured HCO3- -secreting intercalated cells should prove useful for defining the cellular regulation of HCO3- secretion.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

Microvascular distribution in normal human synovium.

The distribution of vessels in normal human synovium has been investigated using frozen sections and staining with Ulex Europaeus lectin by an indirect immunoperoxidase technique. The presence of a vascular net close to the tissue surface was confirmed. Quantitative analysis showed the majority of vessel profiles to be small venules with a peak density 25-100 microns beneath the tissue surface. A smaller number of capillaries was present with a peak density within 25 microns of the tissue surface. It is suggested that important functions of the numerous venules seen in synovium may include the provision of a source of fresh monocytes to replace surface macrophages and provision of nutrients for the surface layer of cells as a whole, and that the density of the vascular net may reflect angiogenic signals from this cell layer.

Anthropometry↗
PubMed1988

Study of teaching residents how to teach.

In the study reported here, the authors evaluated the effectiveness of a teaching skills program for residents. Twenty-two residents in obstetrics and gynecology, medicine, and family medicine were randomly assigned to control and experimental groups. The experimental groups received instruction and feedback about teaching skills during their first and second postgraduate years. Both groups were evaluated at three times: in the first year before the instructional program, in the second year during the instructional program, and in the third year six months after instruction. During each study phase, videotapes were made of each resident teaching a student in the context of a case presentation. Trained raters evaluated eight teaching skills exhibited in the videotapes. In general, there was greater increase and less decline in the scores of the experimental than the control groups. These data suggest that teaching skills can be improved by instruction and that without support residents' teaching skills do not improve in relation to their clinical competence.

Evaluation Studies as Topic↗
PubMed1988

Evaluation of a teaching skills improvement programme for residents.

This study addressed three evaluation questions about the effectiveness of a workshop to teach residents how to teach: (1) How do residents evaluate their own teaching skills? (2) How do students evaluate residents' teaching skills? (3) Do residents of various specialties differ in their teaching skills? One hundred and five residents rated their skills on the Inventory of Teaching Behavior significantly higher after attending the workshop than before it. Third-year students evaluated the teaching skills of both residents who had attended the workshop and those who had not. On four of the nine items of the Clinical Teaching Assessment Form, students rated residents who had attended significantly higher than the control residents. Some differences in teaching skills among the various specialties were found as were differences between resident self-rating and student rating. These data suggest that giving residents instruction can improve their teaching skills. By doing so, both the residents and the programme can benefit.

Curriculum↗
PubMed1988

Quantitative histological analysis of antigen-induced arthritis in the rabbit.

Antigen-induced arthritis in the rabbit (AIAR) provides the closest experimental equivalent to human rheumatoid arthritis in terms of infiltration of synovial tissue by lymphoid cells. A method is described for quantitative histological analysis of AIAR. Measurements of total cell numbers, lymphocyte and polymorphonuclear leucocyte infiltration, and thickness of infiltrated synovium were obtained for ranges of antigen dosage and duration of arthritis. The method has been devised as part of a system for the analysis of joint swelling, synovial fluid biochemistry and cytology, cartilage proteoglycan chemistry and synovial histology on the same specimen.

Animals↗