Search PubMed⌕ Search

Biomedical subjects

D M MacDonald

Publications and source records attributed to D M MacDonald.

At least 145 records · Page 8Linked to original sources
PubMed1984

Inflammatory characteristics of platelet activating factor (PAF-acether) in human skin.

The phospholipid PAF-acether is released from a range of inflammatory cell types and, in experimental animals, has properties appropriate to a mediator of inflammation. We have studied the inflammatory characteristics of intradermally injected PAF-acether in human skin. An early weal and flare response was succeeded, in a proportion of subjects, by an area of late-onset erythema at the site of the resolved weal, reminiscent of the dual response to allergen in sensitized individuals. The time-course and dose-response relationship of the early response has been determined and a synergistic interaction between PAF-acether and prostaglandin E2 established. PAF-acether should therefore be considered as a potential mediator of both acute and persisting inflammation in man.

Adult↗
PubMed1984

The diagnostic value of parakeratosis.

A study of dermatopathological specimens exhibiting parakeratosis has been made and the parakeratosis classified on morphological and topographical criteria. Twelve patterns of parakeratosis have been identified and their association with particular pathological conditions described.

Humans↗
PubMed1984

Ultrastructural features of metastatic cutaneous carcinoid.

Tissue from the cutaneous metastases of bronchial carcinoid was examined. Fine argyrophil secretory granules were demonstrated in the cytoplasm of the abnormal cells which showed positive labelling with neuron-specific enolase. Ultrastructural studies revealed numerous electron-dense membrane bound neuro-secretory granules, 50-300 nm in diameter. Other characteristic features included inter-digitating pseudo pod-like processes (up to 2 mu in size) in the cytoplasmic membrane, perinuclear filaments, a well-defined Golgi zone and numerous large mitochondria.

Aged↗
PubMed1984

Prevalence of lactase deficiency in British adults.

The prevalence of lactase deficiency in British adults is unknown. Examination of the distribution of lactase activities in single and multiple biopsies of jejunum indicated that 0.8 U/g wet weight was a suitable cut-off point to separate lactase deficient patients from others. One hundred and fifty white British adults were selected, none of whom had significant intestinal disease and all of whom had normal histopathology of a jejunal biopsy and normal activities of other disaccharidases measured in the biopsy. The prevalence of lactase deficiency in this group was 4.7%. In contrast, 15 of 20 non-white adults were lactase deficient. Lactase deficiency was found in only three of 36 patients investigated because of diarrhoea after gastric surgery, and in 16 of 200 patients with irritable bowel syndrome (8%). As the prevalence of lactase deficiency is no higher in irritable bowel syndrome than in 'normal' individuals, lactase deficiency clearly is not a predisposing factor for irritable bowel syndrome in white British adults although the two conditions may occasionally coexist.

Adult↗
PubMed1984

Pagetoid reticulosis. Histiocyte marker studies.

Epidermal mononuclear cell infiltrate from three patients with pagetoid reticulosis was examined for the presence of the cytoplasmic markers lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin, using specific antisera and a peroxidase-antiperoxidase technique. Many of the infiltrating cells possessed these markers, indicating that they belonged to the monocyte-macrophage-histiocyte series.

Adult↗
PubMed1983

Absence of human leukocyte antigen molecules in skin tumors and some cutaneous appendages: evidence using monoclonal antibodies.

Four highly sensitive monoclonal antibodies were assessed for their use in an immunoperoxidase technic on cutaneous sections. Three, B2, C23, and 2A1, were found to discriminate basal cell carcinomas (BCCs) from benign proliferative disorders of skin, and 2A1, a monoclonal antibody against the heavy chain component of class 1 human leukocyte antigens (HLA) for the first time directly demonstrated the absence of this structure from the malignant cell membrane. However, the deeper portions of hair follicles were also found to be unlabeled, and further study of benign follicular tumors which may histologically mimic basal cell carcinomas is suggested.

Antibodies, Monoclonal↗