Biomedical subjects
Publications and source records attributed to M Beard.
A peroxide generating oxidase is demonstrated cytochemically in the peroxisomes of adult and larval Drosophila melanogaster, Oregon R and Rosy-506 strains. This enzyme activity is demonstrable using D-pipecolate or D-proline, but not L-proline, as substrate and is inhibited by kojic acid. Thus this enzyme shares cytochemical characteristics with vertebrate D-amino acid oxidase.
Neonatal hypotonia, seizures beginning at 5 days, and severe retardation were noted in a girl with normal karyotype and biochemical evidence of impaired adrenal function. Postmortem examination at 14 months revealed malformative and destructive lesions of central gray and white matter, atrophy of adrenal cortex with striated adrenocortical cells, hepatic fibrosis, and PAS-positive macrophages in several organs. Pathologically and clinically, this patient most closely approximated neonatal adrenoleukodystrophy (ALD) and differed strikingly from X-linked childhood ALD. In contrast, biochemical changes resembled the abnormalities observed in X-linked ALD and differed from those in the neonatal form. The very-long-chain fatty acid accumulation characteristic of both disorders was demonstrated, but unlike neonatal ALD, the levels or metabolism of plasmalogens, pipecolic acid, phytanic acid, and bile acid intermediates were normal, and peroxisomes in a liver biopsy specimen were present in normal number and appeared enlarged. While the case resembles the recently reported entity of peroxisomal acyl-CoA oxidase deficiency, assignment to this category was excluded by immunoblot studies on postmortem liver, which revealed normal amounts of this enzyme. Correlation of clinical, morphologic, and biochemical data suggests that this case is an example of a so-far undescribed entity, and reinforces the concept that the phenotypic spectrum of peroxisomal disorders is wider than realized.
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Extracts of the atrial gland of the sea hare Aplysia californica (Mollusca) induce egg laying when injected into mature individuals. Since egg laying is controlled endogenously by a peptide secreted by neuroendocrine cells in the central nervous system, the relationship between the atrial gland and these central neurons has become an issue of interest. With the particular objective of examining secretory structures we undertook an ultrastructural study of the atrial gland and adjacent tissues. This study revealed that the atrial gland epithelium in composed of two major cell types: 'goblet-like' exocrine cells containing large electron-dense granules, and ciliated 'capping cells'. A non-secretory, and possibly post-secretory, cell containing electron-lucent granules was noted. A region of the large hermaphroditic duct contiguous ot the atrial gland, known as the red hemiduct, also displayed capping cells and secretory cells with large granules. The content of these granules is organized into crista-like condensations. The cell also contains iron-rich pigment inclusions.
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24 patients with Philadelphia chromosome positive chronic myeloid leukaemia (CML) in blast crisis were treated with intensive chemotherapy. 16 patients showed either partial or complete response to this treatment, but median survival remained short (13 weeks), and much of this time was spent in hospital. These results were not significantly better than those obtained by others using vincristine and prednisolone alone, and this combination of drugs can often be given on an outpatient basis. It is concluded that until more effective intensive therapy becomes available patients in CML blast crisis should be managed in such a way that the quality of life is not impaired; and that at present vincristine and prednisolone appears to be the most impaired; and that at present vincristine and prednisolone appears to be the most appropriate initial treatment, though even this is far from satisfactory.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
An observational study was carried out to assess the effect of bacterial growth on changes in platelet cellular indices and leucocyte content. Platelet derived from pooled buffy coats, with and without an additional leucocyte removal step by filtration and platelet derived from Cobe LRS system were used. These were spiked with two doses of several types of bacteria (1 and 50 CFU) in a paired control and test experiment. The changes in cellular parameters were monitored by an automated cell counter (Sysmex SE-9000) and the concentration of the residual leucocyte were evaluated by two automated techniques, based on DNA staining principles (flow cytometry-EPICS-XL Coutter and Imagn 2000). Our results indicate that initially bacterial growth is associated with a decrease in leucocyte count, followed by a concomitant increase in platelet large cell ratio, possibly due to aggregate formation. During the prolonged storage a dramatic increase in pseudoleucocytes was observed by both Imagn 2000 and flow cytometry techniques with an abnormal dot plot around FL3 regions in the latter counting method, making the true identification of native leucocytes rather difficult. It is concluded that bacterial growth is associated with both changes in platelet cellular indices and development of cellular aggregates and/or partially fragmented cells with DNA binding properties appearing as pseudoleucocytes. Further work on the true nature of so called 'pseudoleucocyte' is in progress.
The effects of a new alpha-2 adrenoceptor antagonist, RS 15385, on sleep and nocturnal penile tumescence (NPT) was assessed by intravenous infusion of the drug, in two doses (high and low), and of placebo through the night in 12 young normal volunteers and 24 men with erectile dysfunction. The drug reduced total sleep time in the younger normal volunteers only with the high dose and in the dysfunctional men with both doses. There was no selective effect on different sleep stages in the normal volunteers, except for an increase in the per cent of total sleep time in Stage 1 with the high dose. The dysfunctional men were divided into two age groups (< 47 years and > 47 years). There was an age-related increase in the proportion of total sleep in rapid eye movement (REM), which was only apparent in the older age group. In the volunteers, there was a curvilinear dose-response effect on NPT. The lower dose modestly increased erectile response, particularly during non-REM sleep, whereas the higher dose reduced erectile response, most noticeably during REM. The only positive effect of the higher dose was an increase in spontaneous erections after lights out before sleep onset. The older dysfunctional group showed no drug effects on NPT. The younger dysfunctional men showed increased erectile response during non-REM with the higher dose, an effect that was also significant in the interval between sleep onset (Stage 2) and first REM.