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Biomedical subjects

A J Malcolm

Publications and source records attributed to A J Malcolm.

120 records · Page 7Linked to original sources
PubMed1982

Metaphyseal changes in Perthes' disease: an experimental study.

Glass microspheres were introduced into the hind-limb circulation of 6 immature Gottingen mini-pigs so as to result in ischaemia of the developing proximal femur. Radiological abnormalities similar to those seen in the metaphysis in Perthes' disease were produced in 1 animal. Histological examination shows that these resulted from arrest of a portion of necrotic growth plate within the metaphysis with a corresponding defect within the growth plate. This was associated with ischaemia of the adjacent epiphysis. These changes support the suggestion that metaphyseal change in Perthes' disease are secondary to epiphyseal ischaemia. It is possible that the growth-plate defect may be the precursor of intrinsic deformity of the femoral head.

Animals↗
PubMed1982

Detection of a tumor-associated antigen on the surface of human myelogenous leukemia cells.

Membrane extracts of human acute myelogenous leukemia cells were passed over immunoadsorbent columns containing antibodies directed to equivalent preparations of pooled normal peripheral blood leukocytes. This material, when compared to equivalent normal cell preparations on nonreducing polyacrylamide gels, demonstrated the presence of four unique bands, not found in normal cell preparations. With the use of a previously described leukemia-specific heteroantiserum, these bands, after elution, were tested for reactivity with the antiserum. The eluted material containing reactive antigen was used to immunize rabbits. The resulting antiserum showed strong reactivity with myelogenous leukemic cells extracts and none with normal materials. A series of bone marrow samples from patients with a variety of lymphoproliferative and myeloproliferative disorders were tested with this antiserum in the fluorescence-activated cell sorter. In every instance, bone marrow cells from patients with acute myelogenous leukemia and chronic myelogenous leukemia showed strong positive fluorescence with this antiserum. However, no bone marrow cells from patients with lymphoproliferative disorders or patients with other leukemias showed any fluorescence above background with this antiserum.

Animals↗
PubMed1981

Local tumour invasion as a prognostic factor in colorectal cancer.

A prospective study was carried out of 404 patients with colorectal cancer who were followed up for a mean period of 42 months. Macroscopic extramural tumour invasion was found at laparotomy in 46 patients undergoing apparently curative surgery and the survival rate was significantly reduced in these patients. The site of primary tumour in the colon or rectum did not influence the incidence of local tumour spread, but local invasion was related to the incidence of lymph node metastases and histological grading of the tumour. A staging classification has been proposed based not on lymphatic metastases, but on the extent of local tumour penetration. This modified staging system combines the operative findings with pathological grading of the tumour and emphasizes the prognostic significance of local tumour invasion.

Adenocarcinoma↗
PubMed1981

The leukocyte adherence inhibition assay as a measure of antitumor immunity in bladder cancer patients.

The leukocyte adherence inhibition test was used to assess antitumor immunity of patients with transitional cell carcinoma of the bladder. Patients and controls were tested against extracts of transitional cell carcinoma as well as extracts of renal cell carcinoma and normal bladder mucosa. Patients with transitional cell carcinoma had significantly greater reactivity compared to patients with other genitourinary disease or normal controls. With a pooled tumor extract from 6 different transitional cell tumors a positive response was obtained in up to 82 per cent of patients with other genitourinary disease. These results suggest that the leukocyte adherence inhibition test is a sensitive and fairly specific test of antitumor immunity in patients with transitional cell carcinoma of the bladder.

Adult↗
PubMed1980

The clinical significance of the pattern of elevated serum carcinoembryonic antigen (CEA) levels in recurrent colorectal cancer.

Serial serum carcinoembryonic antigen (CEA) assays were performed in 148 patients after potentially curative surgery for colorectal cancer. Thirty-seven patients developed proved recurrent tumour in a follow-up period of 2-5 years. Elevated CEA levels were recorded in 36 of these patients and in 27 rising levels preceded clinical symptoms of recurrent tumour. Two distinct patterns of CEA rise were observed: a 'fast' rise in which serum concentrations reached 100 microgram/l within 6 months of the first elevation and a 'slow' rise in which concentrations remained less than 75 microgram/l for at least 12 months. The majority of patients with the 'fast' rise had metastatic spread, whereas most patients with a 'slow' rise had local recurrence alone. This differential pattern may help to predict the site of recurrent tumour.

Adenocarcinoma↗
PubMed1979

The effect of hapten-specific suppression of IgE on antigen-induced histamine release from mouse peritoneal mast cells.

Subcutaneous injections of a mixture of dinitrophenylated ovalbumin (DNP3-OA) and dextran sulfate into Swiss-Webster mice elicited short-lived primary and long-lasting secondary IgE antibody responses to both DNP and OA. Histamine was released on in vitro challenge with antigen (OA or DNP22-BSA) of washed peritoneal mast cells (PMC) obtained from mice during a primary or a secondary IgE response. Administration of an intravenous injection of a tolerogenic conjugate of DNP8-mouse gamma-globulin, either prior to immunizationor during an ongoing IgE response, resulted in almost complete disappearance of circulating anti-DNP IgE antibody and in a very marked decrease in histamine release from PMC on challenge with DNP22-BSA. However, the IgE response to OA of these mice and the histamine release from their PMC on challenge with OA were not affected. Moreover, the PMC of mice, which had been tolerized to DNP, could be passively sensitized with serum containing DNP-specific IgE antibody for the release of histamine on DNP22-BSA challenge. The most significant finding of this study is the observation that the time course for the loss of reactivity of PMC to DNP22-BSA, after administration of the tolerogen during an ongoing secondary response, paralleled the decrease in circulating anti-GNP IgE antibody.

Animals↗
PubMedDate not supplied

Birbeck granules in synovial cells from a patient with rheumatoid arthritis.

Although Langerhans cells were first described as long ago as 1868, it is only relatively recently that details of their structure and function have been ascertained. They appear to be of importance in immune reactions and have been found in mammals in most squamous epithelia, including skin, buccal mucosa, esophagus, and vaginal and rectal mucosa. One of features of these cells is the presence of organelles called Birbeck granules on electron microscopy. We report the presence of cells containing Birbeck granules in the synovium of a patient with rheumatoid arthritis.

Arthritis, Rheumatoid↗