PubMed Health⌕ Search

Biomedical subjects

B Brownell

Publications and source records attributed to B Brownell.

At least 19 recordsLinked to original sources
PubMed2000

Trends in the in-hospital treatment of acute myocardial infarction between 1984 and 1993 - The Halifax County MONICA Project.

BACKGROUND: The Halifax County MONItoring of trends and determinants in CArdiovascular disease (MONICA) Project found that between 1984 and 1988, the proportion of myocardial infarctions (MIs) that were fatal within 28 days remained constant, but declined between 1989 and 1993. The objective was to investigate association among case fatality, treatment and case severity of MI in hospitalized patients. PATIENTS AND METHODS: The MONICA MI register contains data on demographics, health history, in-hospital investigations, interventions and treatment, and vital status at 28 days after onset of symptoms for all MIs occurring in residents of Halifax County, aged 25 to 74 years. Logistic regression analysis was used to estimate trends in the use of cardioactive drugs and revascularization procedures. A case severity score was developed from patient characteristics at time of admission. Case fatality was calculated as the proportion of MIs that were fatal within 28 days. RESULTS: Between 1984 and 1988, a large increase (OR 1.3) occurred in the use of angiotensin-converting enzyme (ACE) inhibitors, acetylsalicylic acid (ASA), thrombolysis and percutaneous transluminal coronary angioplasty (PTCA); a minor increase occurred in use of calcium channel blockers (OR=1.29, 99% CI 1.19 to 1.40); beta-blocker use decreased; case fatality remained constant and case severity score increased. From 1989 to 1993, ACE inhibitor use increased (OR=1.4, 99% CI 1.27 to 1.55); minor increases occurred in use of ASA and beta-blockers, and in PTCA and coronary artery bypass grafting; case severity did not change and case fatality decreased. CONCLUSIONS: While use of beneficial treatment increased between 1984 and 1988, MI case fatality did not decrease, probably because case severity increased. Between 1989 and 1993, case severity remained constant, and the further increase in the use of beneficial therapy was associated with a decline in case fatality.

Acute Disease↗
PubMed1985

The role of monoclonal antibodies in brain tumour diagnosis and cerebrospinal fluid (CSF) cytology.

This paper reviews the diagnostic role of monoclonal antibody immunohistochemistry in a series of 189 brain tumour biopsies and 22 cases of neoplastic meningitis. The diagnostic monoclonal antibody panel, which includes markers for glial, neural, epithelial and lymphoid differentiation antigens, was used to test a wide variety of cerebral and spinal tumours by indirect immunofluorescence and immunoperoxidase techniques on unfixed frozen sections. Gliomas, meningiomas, schwannomas, medulloblastomas, choroid plexus tumours, cerebral lymphomas and metastatic carcinomas could all be reliably differentiated by means of their characteristic antigenics profiles, as defined by their patterns of reactivity with the antibody panel. Confident diagnosis was possible even in very poorly differentiated tumours and in biopsies distorted by surgical squeeze artefact, where paucity of morphological clues made diagnosis by conventional histological methods difficult or impossible. It was estimated that use of the antibody panel was responsible for, or made a significant contribution towards the final diagnosis in approximately 20% of cases. The monoclonal reagents were also found to be of great value in the detection and characterisation of neoplastic cells in CSF specimens from patients with malignant meningitis. Malignant cells were detected in 73% of cases and characterised in 16% of cases by routine cytological techniques. Employing monoclonal immunocytology however, these figures were improved to 95% and 95% respectively. Our findings suggest that patients with neoplastic meningitis can be spared prolonged investigation and inappropriate management by the early detection and characterisation of malignant cells in CSF using panels of monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1985

Immunohistological diagnosis of central nervous system tumours using a monoclonal antibody panel.

A panel of seven monoclonal antibodies has been used to characterise 164 cerebral and spinal tumours. These reagents have enabled rapid and accurate diagnosis of tumours to be made, particularly in cases where standard techniques have proved equivocal. On the basis of characteristic antigenic profiles of tumours, it has been possible to distinguish between gliomas, meningiomas, schwannomas, medulloblastomas, neuroblastomas, choroid plexus tumours, various metastatic deposits, and primary brain lymphomas. The reagents used in the study comprise antibodies binding to (a) most neuroectodermally derived tissues and tumours (UJ13A), (b) fetal brain and tumours of neuroblastic origin (UJ181.4), (c) schwannomas, normal and neoplastic neurones (UJ127.11), (d) glial cells (FD19), (e) epithelial cells (LE61), and (f) leucocytes (2D1). Some reagents, such as antibody A2B5, were less effective as diagnostic markers than originally suggested by previously described specificity. This monoclonal antibody reacted with both neuroectodermal and epithelial derived tumours. The panel of monoclonal antibodies was most useful in the diagnosis of tumours composed of small round cells, particularly lymphoma and neuroblastoma, but the pattern of reactivities allowed most of the central nervous system tumours to be accurately classified. This approach was a valuable adjunct to conventional histological techniques in about 20% of the cases examined.

Aged↗
PubMed1985

Subependymomas of the fourth ventricle. Surgical treatment in 12 cases.

Subependymomas of the fourth ventricle are generally considered incidental postmortem findings, and have received scant attention from neurosurgeons. The authors present a surgical series of 12 cases of this disorder diagnosed over a 13-year period. The clinical and radiological findings were reviewed and correlations made with pathological studies. The subependymoma is a histologically benign tumor that tends to be calcified. It has a predilection for the fourth ventricle and a peak incidence in the fifth decade of life. It is usually of considerable size with extensive attachment at the time of its detection, and is associated with significant surgical morbidity. The authors believe that magnetic resonance imaging may be the best method of investigation. Intraoperative disturbance of circulatory or respiratory control should suggest to the surgeon that the operation be abandoned. A laser or ultrasonic aspirator may be very helpful in removing these tumors. Postoperative care must include monitoring for apnea.

Aged↗
PubMed1984

Use of monoclonal antibody panel to identify malignant cells in cerebrospinal fluid.

A panel of monoclonal antibodies was systematically applied to cerebrospinal fluid from 17 patients with suspected neoplastic meningitis and the results were compared with those obtained from routine cytological preparations. The antibody panel consisted of markers for neuroectodermal tissue ( UJ13A ), epithelial cytokeratin ( LE61 ), leucocytes ( 2D1 ), and neoplastic neuroblasts ( UJ181 .4). Additional antibodies were used to refine diagnosis when indicated. Cerebrospinal fluid samples from 12 patients with non-neoplastic conditions were used as controls. The use of monoclonal antibodies gave a positive diagnosis in 16/17 cases and the cells were accurately categorised as carcinoma (5/6 cases), neuroectodermal tumour (8/8 cases), and lymphoma (3/3 cases). In the 14 cases examined by routine cytology, malignant cells were reported in 10 cases and accurately categorised in only 3/14 cases. Immunocytological testing of cerebrospinal fluid with an antibody panel has greatly increased the accuracy with which malignant cells can be identified and categorised.

Aged↗
PubMed1983

Biological characterization and clinical applications of a monoclonal antibody recognizing an antigen restricted to neuroectodermal tissues.

The monoclonal antibody UJ13A was raised following immunization of mice with human foetal brain and subsequent somatic cell hyridization of spleen cells with the mouse myeloma cell line P3-X63-AG8-653. The antibody is of the IgG1 subclass and has been shown by indirect immunofluorescence studies on normal foetal, paediatric and adult tissues to selectively bind to most tissues of neuroectodermal origin. Many tumours of neural origin also express the UJ13A antigen and the reagent can be used to distinguish primary intracranial neural tumours from secondary carcinomas and lymphomas. UJ13A is also useful as one of a panel of reagents employed for the identification of metastatic spread of neuroblastoma cells to bone marrow and cerebrospinal fluid. Knowledge of the full spectrum of normal and malignant tissues binding UJ13A suggests that the antibody may have a role in the radioimmunolocalization of neuronal tumours such as neuroblastoma.

Animals↗
PubMed1982

Distribution of measles antigen and immunoglobulin-containing cells in the CNS in subacute sclerosing panencephalitis (SSPE) and atypical measles encephalitis.

The immunoperoxidase technique has been used to study the distribution of measles virus antigen and immunoglobulin (Ig)-containing cells within the CNS, in 5 cases of subacute sclerosing panencephalitis (SSPE) and 1 case of atypical measles encephalitis. Measles virus antigen was demonstrated within the brain in all cases, and in the spinal cord in 1 case of SSPE. Ig-containing cells were also demonstrated in all cases, the proportions of the different light and heavy chain types varying somewhat from case to case. In SSPE IgG constituted the major and IgA the principal minor heavy chain demonstrated. In all cases of SSPE there was significant excess of light-chain-containing over heavy-chain-containing cells. In the case of atypical measles encephalitis there was a paucity of Ig-containing cells and a relatively high proportion (39%) of these contained IgM. The case of atypical measles encephalitis differed from those of SSPE also in the presence of multinucleate giant cells, some of which contained measles virus antigen.

Adolescent↗
PubMed1981

Computed tomographic appearances in microgliomatosis.

The computed tomography (CT) appearances of 11 patients with microgliomatosis have been reviewed, and as a result it is possible to suggest that there may be typical features for the recognition of such tumours. In this series three fairly distinctive patterns were encountered. In view of their reputed response to radiotherapy, there is a strong case for making the diagnosis of such lesions, and CT has given the opportunity of alerting the surgeon and the pathologist to the likelihood of their presence at an early stage.

Aged↗
PubMed1981

Primary amoebic meningoencephalitis.

The third case in the UK of primary amoebic meningoencephalitis is reported; it affected an 11-year-old girl. Six days before admission the girl had swum in a pool fed by hot spring water in which the causative agent Naegleria fowleri was found. Early treatment with amphotericin B would seem to offer the only hope of recovery in this almost uniformly fatal infection.

Amebiasis↗
PubMed1979

Effects of the oral administration of Cannabis sativa (dagga) on chacma baboons (Papio ursinus).

Eighteen adult chacma baboons were fed Cannabis sativa, the plant material being incorporated into their food. They were divided into three equal groups. Group 1 animals were fed on 2% cannabis in food for 4 months, after which 2 animals remained on 2%, 2 were given 4% and 2 6% cannabis in food for the next 4 months. They became mildy apathetic. Five gained weight. Serum glucose, potassium and CO2 values decreased. Neuropathological examination of their brains did not show any significant abnormality. Group 2 animals were fed 10% cannabis for several weeks. They ate less and lost weight, and later became very apathetic. Right temporal biopsies were done in all and in 3 the tissue was analysed for glutamine, glutamate, tryptophan, ammonia and cyclic AMP. No significant change was found. Serum glucose and CO2 levels rose and potassium levels fell. Blood cholesterol values decreased in 3 of the 9 males. Group 3 animals were fed 6% cannabis for 2--4 months. Radio-immunoassay of sera and urine showed the presence of cannabinoids. They became apathetic, and 5 lost weight. Serum glucose and potassium levels (measured in the males) decreased. No neuropathological lesions were found in the brains, apart from an incidental leptomeningitis in 1 animal which died suddenly. The question of cannabis encephalopathy is discussed.

Administration, Oral↗
PubMed1976

Malignant spread of haemangioblastoma: report on two cases.

Two cases are described in which, after successful removal of a cerebellar haemangioblastoma followed by several years of freedom from symptoms, there developed a progressive spinal cord compression, leading to death. At necropsy the spinal cords in both cases and the brainstem in one case, were irregularly plastered with haemangioblastoma. Although there was no doubt that malignant spread had occurred from one or more primary tumours, the histology of the tumour tissue was in no way different from that of conventional haemangioblastoma.

Adenoma↗
PubMed1975

Granulomatous myopathy: its relationship to sarcoidosis and polymyositis.

In three cases of generalized muscle weakness, muscle biopsy revealed well-defined, non-caseating epithelioid granulomata with giant cells. In one of these patients there was, in addition, a high serum CPK and histological evidence of widespread muscle cell degeneration and regeneration, apparently unrelated to the granulomatous process. In a re-examination of the histopathology of these cases, using biopsy material from a fourth case of proven sarcoidosis as a standard, it was concluded that there are no special features of the granulomatous/giant cell process which permit the separation of the case of presumed polymyositis. However, it appeared that granulomata per se do not exert a significant ill effect on surrounding muscle cells, and that evidence of widespread degeneration of muscle cells is the important point of distinction.

Adult↗
PubMed1975

Degeneration of muscle in association with carcinoma of the bronchus.

The clinical features and necropsy findings are described in three cases in which severe and rapidly progressive muscle weakness developed in association with carcinoma of the bronchus. In all three cases, muscular weakness was directly responsible for death. Histological and ultramicroscopical examination in all cases showed an unusual type of degeneration of muscle fibres accompanied by degeneration of intramuscular nerve fibres, but without involvement of the central nervous system, or of the peripheral nerve trunks. The findings are compared with those of previously reported cases, and possible mechanisms for the muscle degeneration are discussed.

Aged↗