Search PubMed⌕ Search

Biomedical subjects

D M MacDonald

Publications and source records attributed to D M MacDonald.

At least 109 records · Page 6Linked to original sources
PubMed1987

Lamellar bodies in hyperkeratosis lenticularis perstans.

An ultrastructural study of lesional skin from 4 subjects with hyperkeratosis lenticularis perstans (Flegel's disease) demonstrated variable numbers of lamellar bodies of normal size and architecture within cells of the stratum granulosum and the upper stratum spinosum. Their characteristic lamellate inclusions were frequently observed within the intercellular spaces. These observations suggest that the lamellar bodies are qualitatively normal in Flegel's disease.

Adult↗
PubMed1986

Monoclonal antibody labeling of mononuclear cell surface antigens in formaldehyde-fixed paraffin-embedded cutaneous tissue.

The influence of the sequential stages of conventional formaldehyde fixation and paraffin embedding of cutaneous tissue on monoclonal antibody labeling of cell surface antigens is described. The effects of variation in fixation time, dehydration, clearing, wax embedding, and enzyme treatment of cutaneous sections were examined. By curtailing fixation time, using cold ethanol dehydration, and limited cold clearing with xylene, immunoreactivity of several important monoclonal antibodies was retained. Wax embedding could be achieved at 58 degrees C for 1 h or by using low-melting-point wax at 42 degrees C for 3 h. Thus was derived an optimal processing procedure which afforded good tissue morphology and allowed reliable reproducible labeling by monoclonal antibodies to cell surface antigens.

Antibodies, Monoclonal↗
PubMed1986

Effect of routine paraffin wax processing on cell membrane immunoreactivity in cutaneous tissue.

The effects of the sequential stages of paraffin wax embedding on immunolabelling of cutaneous cell membrane antigens by monoclonal antibodies are described. Modifications in incubation times for fixation, dehydration, clearing and wax embedding of sections were examined. Labelling of the cell surface antigens deteriorates only after formal saline fixation for a period longer than 4 hr. Dehydration in ethanol had a minor adverse influence but clearing in xylene diminished immunoreactivity markedly. Both deleterious effects could be circumvented by conducting the procedures at 4 degrees C. The wax embedding procedure at 58 degrees C adversely affected labelling after 1 hr.

Antibodies, Monoclonal↗
PubMed1986

The simultaneous presence of Langerhans' cell and interdigitating cell antigenic markers on inflammatory dendritic cells.

Immunohistological studies have been performed on tissues from various dermatological conditions using two monoclonal antibodies, RFD1 and NA1/34. These reagents were used to determine whether antigen expression restricted to interdigitating cells (RFD1+) and Langerhans' cells (NA1/34+) in normal tissues might occur together on dendritic cells involved in cutaneous inflammatory reactions. The results presented demonstrate that in psoriasis, allergic contact dermatitis and atopic dermatitis a proportion of the inflammatory dendritic cells express both antigens.

Antigens, Surface↗
PubMed1985

Metastatic cutaneous carcinoid.

A case of malignant bronchial carcinoid with multiple cutaneous metastases is reported. Despite the extremely aggressive behavior of the disease and the presence of multiple hepatic metastases, the patient did not exhibit the usual clinical features of the carcinoid syndrome. The relevance of the finding of elevated 24-hour urinary vanillylmandelic acid levels in patients with carcinoid tumors is discussed.

Aged↗
PubMed1985

Exploitation of phylogenetic distance in cell surface immune labeling: studies with beta 2-microglobulin.

Beta 2-microglobulin (beta 2M) is part of the HLA molecule, and is found on the cell surface of human nucleated cells. In certain skin tumors, malignant change has been associated with a loss of this surface beta 2M, indicating a possible diagnostic value for this marker. At present beta 2M is best identified in paraffin-embedded tissue by means of a triple-layer peroxidase-antiperoxidase technique, using mammalian polyclonal antisera. Recently a polyclonal antiserum against human beta 2M has been produced in chickens. Because of the phylogenetic differences between the species, the resulting antiserum is likely to recognize more epitopes on the beta 2M and show greater sensitivity than antisera raised in mammalian species. To confirm this hypothesis, the avian antiserum was compared to both mammalian polyclonal (rabbit) and monoclonal (mouse) antibody in vitro. beta 2M fixed to plastic surfaces combined with more avian than mammalian antibody. Furthermore, insolubilized chicken antibody could bind more secondary antibody-horseradish peroxidase conjugate than could insolubilized mammalian antibody, thus showing even greater enhancement with this system. Immunohistochemical analysis of these systems confirmed that the chicken strategy has greater sensitivity, and can be used in an indirect system with consequent reduction in nonspecific background activity. It is the most suitable technique for the investigation of the distribution of beta 2M in paraffin-embedded tissue.

Animals↗