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Biomedical subjects

M Burke

Publications and source records attributed to M Burke.

At least 253 records · Page 14Linked to original sources
PubMed1990

Fine needle aspiration biopsy in the diagnosis and management of fibroadenoma of the breast.

Cytological and histological biopsies were obtained on 75 breast lumps clinically diagnosed as fibroadenomas. Of these, 95 per cent of lesions were benign. In 51 (68 per cent) confirmed as fibroadenomas histologically, cytology was benign in 78 per cent, but inadequate for diagnosis in 16 per cent. The remaining 24 lesions included three breast cancers and one lymph node with Hodgkin's disease. In this group cytology was inadequate for diagnosis in 54 per cent, including one breast cancer. No lesion with benign cytology was subsequently shown to be malignant. The study supports the view that clinical diagnosis and cytology are accurate in the diagnosis of benign breast disease of this type. Breast cancer may rarely present with the clinical features of a fibroadenoma and too few lesions have been studied to assess fully the performance of cytological biopsy in detecting these small mobile lesions. A non-excisional policy should therefore include prolonged follow-up and repeat biopsy.

Adenofibroma↗
PubMed1990

A comparison of the psychopharmacological profiles of phencyclidine, ketamine and (+) SKF 10,047 in the trimethyltin rat model.

The potential neuroprotective effects of phencyclidine, ketamine and (+) SKF 10,047 were investigated in the trimethyltin (TMT)-treated rat. Of the three drugs used in this study, only phencyclidine (5 mg/kg i.p.) reversed the behavioral hyperactivity and deficits in spatial localization of TMT-treated rats. Neurochemically, phencyclidine and (+) SKF 10,047 were without effect on the neurotransmitters (e.g. noradrenaline, dopamine, serotonin and 5-hydroxindole 3-acetic acid), examined in the amygdaloid cortex and hippocampal regions, while ketamine increased the steady state concentrations of 5-HIAA in the amygdaloid cortex. These results suggest the involvement of the phencyclidine receptor in reversal of the behavioural impairments produced by TMT in rats. The significance of these results with respect to phencyclidine and sigma receptors is discussed. The lack of effect of (+) SKF 10,047 in this model may reflect behavioural differences between phencyclidine and sigma ligands. It may be concluded that the TMT model can be exploited for studying the mechanism of action of molecules liable to have an effect at the phencyclidine receptor site, as opposed to the sigma receptor.

Animals↗
PubMed1990

Inappropriate major histocompatibility complex expression on cardiac tissue in dilated cardiomyopathy. Relevance for autoimmunity?

The inappropriate expression of major histocompatibility complex (MHC) molecules on epithelial and endothelial cells is a recognized marker of autoimmune disease. An autoimmune pathogenesis has been suspected in dilated cardiomyopathy (DCM). In the normal heart, MHC products are usually not detectable on myocytes using immunochemical techniques. MHC molecule expression has not, however, been assessed on cardiac endothelial cells. The aim of this study was to investigate possible autoimmune phenomena and MHC molecule expression in fresh endomyocardial biopsies from 29 patients with DCM. These were compared with those observed in surgical specimens from 63 patients with other acquired cardiac disease and from 22 with congenital heart disease (CHD) as normal controls. Conventional immunofluorescence (IFL) with monoclonal antibodies (MoAbs) to lymphocyte and macrophage markers and to MHC molecules was employed, and double IFL with antiserum to human Factor VIII was used for the identification of endothelial cells. Myocytes did not express MHC molecules in either DCM or controls. In normal hearts, Class II molecules were detected on endothelial and endocardial cells in only a few cases (3/22 and 2/22 respectively). By contrast, endothelial and endocardial cells inappropriately expressed Class II in a high proportion of DCM patients (28/29 and 22/29) but less frequently in other acquired cardiac diseases (19/63, P less than 0.001 and 11/63, P less than 0.001 respectively). In all the DCM biopsies examined there was a hierarchy of Class II subloci product expression (DR greater than DP greater than DQ); lymphocytic infiltration was a rare finding and macrophages/dendritic cells were not prominent. The finding of inappropriate MHC Class II molecule expression on cardiac endothelial and on endocardial cells suggests a possible pathogenic role for these cells in the initiation and/or perpetuation of DCM.

Adolescent↗
PubMed1990

Poliovirus vaccination responses in HIV-infected patients: correlation with T4 cell counts.

HIV infection is known to impair both cellular and humoral immunity. The antibody levels to poliovirus were measured in 17 HIV-infected and 3 HIV-seronegative homosexual men before and after vaccination with enhanced inactivated poliovirus vaccine (eIPV). The subjects were tested for neutralizing antibodies to poliovirus types 1, 2, and 3; the number of peripheral blood T4 cells and lymphocyte responses after stimulation with phytohemagglutinin, concanavalin A, and pokeweed mitogen were measured. Before vaccination, all subjects demonstrated neutralizing antibodies to the three types of poliovirus. After eIPV administration, a rise in anti-poliovirus antibody titer was noted in subjects whose T4 cell count was greater than 200/ml, whereas the group with low T4 cell counts failed to respond. The response to eIPV immunization correlated with the number of circulating T4 cells and the mitogen-induced lymphocyte stimulation index.

Adult↗
PubMed1990

Insulinoma after streptozotocin therapy for metastatic gastrinoma: natural history or iatrogenic complication?

Islet cell carcinoma frequently produces more than one chemical product, although its clinical expression is usually restricted to a single hormone. We describe an unusual patient who presented with full-blown metastasizing gastrinoma. He was treated with cimetidine for five years and then streptozotocin therapy, which resulted in a regression in hepatomegaly and a fall in serum gastrin levels. Following one year's therapy with streptozotocin, he was admitted in hyperinsulinemic hypoglycemic stupor. This appears to be the first reported case of a "shift" from clinical gastrinoma to insulinoma possibly related to prolonged streptozotocin therapy.

Adenoma, Islet Cell↗
PubMed1990

A typology of medical practice organization in Canada. Data from a national survey of physicians.

Different modes of practice organization may result in advantages for physicians and their patients. Compared with solo practice, group practice may produce economies of scale, efficiencies in health care delivery, and improvements in the quality of care. However, in Canada assessment of the implications of differences in practice organization have been impeded by a lack of relevant data and a tendency to treat practice type as a dichotomous variable. Conventional solo/group distinctions fail to address the significance of the growing number of medical practices that are neither solo nor group, but combinations of both, and they obscure the policy implications of the growing number of physicians in institutional as opposed to private practice. This paper develops and applies a theoretically based typology of practice organization to data collected as part of a national survey of 2,398 Canadian physicians conducted in late 1986 and early 1987. The analysis identifies six practice types, describes their distribution and operating characteristics, and identifies the characteristics of physicians working in them.

Canada↗
PubMed1990

Viral myocarditis.

Evidence suggests that in susceptible individuals lymphocytic myocarditis is a virus-induced autoimmune disease which may progress to dilated cardiomyopathy. Its biopsy pathology, the application of the 'Dallas' criteria for diagnosis and the role of immunohistochemistry are discussed. The potential role for in situ hybridization in the detection of viral genomes is referred to. Pathogenesis may be related to persistence of viral RNA in tissues and may involve both cellular and humoral immune mechanisms. The effect may manifest itself at cellular level with myocytolysis or at sub-cellular level with interference in energy production, giving rise to considerable functional deficit with few morphological changes.

Autoimmune Diseases↗
PubMed1990

Acquired immunodeficiency, malabsorption and lymphoma.

A 66 year old female with a long history of recurrent pulmonary infection presented with a full-blown malabsorption syndrome. She was found to be suffering from acquired immunodeficiency. She later developed non-Hodgkin's lymphoma of the cervical lymph nodes. The possible relationships between immunodeficiency, malabsorption and lymphoma are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Comparison of fine needle aspiration cytology, radioisotopic and ultrasound scanning in the management of thyroid nodules.

In 175 patients presenting with thyroid nodules, the diagnostic value in management of fine needle aspiration and cytology (FNAC), pertechnetate (99mTc) scanning and ultrasound imaging was examined. In 82 patients, the diagnosis was confirmed at operation; in the remaining 93, there was a follow-up period of at least 2 years. Thyroid cancer was found in 13 patients. For FNAC the sensitivity, specificity and positive predictive value for thyroid cancer were 92%, 85% and 41% respectively compared with 82%, 34% and 11% for 99mTc pertechnetate scanning, 75%, 61%, 19% for ultrasound and 73%, 58% and 19% for combined pertechnetate and ultrasound scanning. In 14% of patients, the aspirates were inadequate for cytology at the first examination. FNAC is therefore the preferable initial investigation and usually gives results adequate for a decision on surgical or medical management. With medical management and follow-up, ultrasound is of value in defining the nodule and the appearance of the rest of the gland.

Biopsy, Needle↗
PubMed1990

The reproduction of physician autonomy in Ontario medical group practice.

A belief exists about the advantages of group medical practice over solo practitioners. The paper through a survey of 105 group practices examines a number of organisational and operational factors. The results suggest that practices are not always organised in a way to maximise the benefits of group operation but are still characterised by an individualistic approach.

Decision Making, Organizational↗
PubMed1990

Testicular neoplasms: seminoma.

From 1969 to 1984, 58 patients with a diagnosis of testicular seminoma were seen and treated at the University of Kansas Medical Center. The median age was 34 years (range of 20 to 62 years). The American Joint Committee on Cancer Staging System was followed: stage I (34 patients); stage II (6); stage III (8); and stage IV (10). Forty-two patients had typical seminoma, and 16 had anaplastic histology. Nine patients had elevated B subunit of human chorionic gonadotropin, and nine had a history of cryptorchidism. Fifty-six patients received radiation treatment, and seven received chemotherapy with or without radiation. The median follow-up was 7 years (range 3 to 16 years). The overall disease-free (absolute) survival according to stage was: stage I, 91% (100%); stage II, 66% (80%); stage III, 75% (85%); and stage IV, 50% (50%). There were no late complications. The survival for patients with anaplastic histology or with elevated B subunit of human chorionic gonadotropin was not significantly different from that of typical seminoma.

Adult↗