Biomedical subjects

C L Dewar

Publications and source records attributed to C L Dewar.

5 recordsLinked to original sources

PubMed1992

Necrotizing mesenteric vasculitis after longstanding cutaneous polyarteritis nodosa.

We describe a 21-year-old woman with cutaneous polyarteritis nodosa (PAN) who developed necrotizing mesenteric vasculitis 6 years after the onset of skin disease. Repeated investigation during that 6-year interval failed to reveal any evidence of systemic PAN. We were unable to wean the patient from prednisone or completely control her skin disease with topical and systemic therapy, including supersaturated potassium iodide, dapsone, azathioprine, methotrexate or plasmapheresis before the development of the mesenteric vasculitis, which responded to cyclophosphamide and prednisone. Development of visceral vasculitis after long-standing cutaneous PAN has very rarely been reported.

Adult↗

PubMed1990

Relapsing polychondritis in pregnancy.

A 25-year-old patient presented at 14 weeks of her 3rd pregnancy with chondritis affecting the cartilaginous portion of her right ear. The clinical syndrome of recurrent chondritis, scleritis, iritis and arthritis supported a diagnosis of relapsing polychondritis. Fetal and maternal outcomes were favorable despite steroid dependent active disease during the period of fetal organogenesis. Chondritis was limited to the 3rd pregnancy, ocular inflammation occurring in the 2nd and 3rd pregnancies. A 4th pregnancy was uneventful. This may represent the first case of relapsing polychondritis in pregnancy.

Adult↗

PubMed1986

Cytolocalization artifacts with immunofluorescent probes.

Formaldehyde fixation, nonionic detergent extraction, and ligand binding are commonly used in conjunction with immunofluorescence microscopy to visualize antigens and lectin-reactive molecules in cytoskeletal preparations. These procedures have the potential to produce serious artifacts in cytolocalization studies, as is shown in the present investigation of wheat-germ agglutinin (WGA) binding and localization in BeWo choriocarcinoma cells. Formaldehyde fixation of intact cells reduced the binding of 125I-labeled WGA by 30% and altered the pattern of staining with fluorescein isothyocyanate (FITC)-WGA. Except for perinuclear sites which were brightly stained, the binding of FITC-WGA to other cell surface regions was significantly decreased. Nonionic detergent extractions had two different effects on lectin binding activity depending on whether or not the cells had been pretreated with lectin. In lectin-pretreated cells, 50% of bound lectin was solubilized by detergent but all of the surface binding sites appeared to be retained in active form in the detergent-insoluble residue. Nuclear-cytoskeletal monolayers prepared from cells that were not lectin pretreated lost considerable binding activity, however. These results suggest that a number of erroneous conclusions can be drawn from studies on cytoskeletal associations with membrane components using immunofluorescence microscopy on fixed and detergent-extracted cells.

Binding Sites↗

PubMed1979

Scanning electron microscopy of blood cells.

Scanning electron microscopy (SEM) is an invaluable tool for studying the surface morphology of isolated blood cells. We have used a simple preparative technique for SEM to study the erythrocytes from a case of Congenital Dyserythropoietic Anaemia type II and the leucocytes from healthy individuals or patients with leukaemia or lymphoma. This rapid and inexpensive technique for fixation and dehydration of blood cells was found to be equally reliable for obtaining micrographs of healthy or diseased leucocytes or erythrocytes.

Anemia, Hemolytic, Congenital↗

PubMed1976

A simple method for processing erythrocytes for scanning electron microscopy.

A simple method for preparing erythrocytes for scanning electron microscopy by sequential fixation with glutaraldehyde and dehydration in a graded series of alcohols is presented. The method will allow visualization of membrane defects not seen under the light microscope and is therefore suitable for routine processing of erythrocytes for diagnosis of pathologic states.

Erythrocytes↗