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Biomedical subjects

M Walsh

Publications and source records attributed to M Walsh.

At least 199 records · Page 11Linked to original sources
PubMed1992

Fungal Pseudoallescheria boydii lung infiltrates unresponsive to amphotericin B in leukaemic patients.

The management of patients with acute leukaemia is often complicated by serious fungal infections, especially of the lungs. The outcome of therapy has historically depended on the early use, efficacy and toxicity of amphotericin B. Pseudoallescheria boydii is an uncommon cause of such infections but as it is more often resistant to amphotericin B early identification may enable the prompt use of alternative and newer antifungal agents. Here we report our experience and review the literature in three cases of P. boydii infection in patients with leukemia, showing unique features such as childhood and central nervous system disease, positive blood cultures and response to itraconazole.

Adolescent↗
PubMed1992

Keratinocyte expression of class II MHC antigens in long-lasting allergic patch test reactions.

The keratinocyte expression of class II MHC antigens HLA-DR, DP and DQ was studied in 20 long-lasting allergic patch test reactions and 17 normal allergic patch tests reactions. No significant difference in the expression of these antigens in the 2 groups was detected. No 1 allergen was responsible for the majority of long-lasting allergic patch test reactions. The immunological mechanisms which may contribute to long-lasting allergic patch test reactions are discussed with reference to HLA-DR keratinocytes.

Adult↗
PubMed1992

Sources of stress in children with asthma.

Children experience stressors related to self-concept and school, family, and peer relationships. This study of children with asthma determined their perceptions of the frequency and severity of stressors they experience other than their asthma. Children with asthma are similar to peers with regard to perceptions of stressors. Teachers, health professionals, and parents should consider children with asthma as normal children who have an additional source of stress--a chronic illness. Results suggest perceptions of most stressors relate more strongly to gender-role development than to asthma. Children with asthma rated feeling left out of the group and not being good enough at sports as serious stressors. School personnel could be instrumental in encouraging management and prevention of exercise-induced asthma and promote all children's full participation in physical activities. Further examination of the relationship between stress and asthma is needed.

Adolescent↗
PubMed1992

A placebo controlled observer blind immunocytochemical and histologic study of epithelium adjacent to anogenital warts in patients treated with systemic interferon alpha in combination with cryotherapy or cryotherapy alone.

OBJECTIVE: To examine biopsy specimens of tissue immediately adjacent to anogenital (AG) warts which had been treated with either cryotherapy plus subcutaneous interferon (IFN) alpha 2a or cryotherapy alone, for histological features of (a) human papilloma virus (HPV) infection (b) localised cellular immune responses, to further characterise any cellular immune infiltrates with tissue immunocytochemistry, and to relate any histological, immunocytochemical findings to the treatment response of nearby AG warts. DESIGN: A randomised placebo controlled observer blind study. SETTING: Genitourinary Medicine clinic, Department of Immunopathology, Royal Victoria Hospital, Belfast, N. Ireland. SUBJECTS: Thirty patients with AG warts; 16 treated with IFN alpha 2a plus cryotherapy, and 14 treated with cryotherapy alone. OUTCOME MEASURES: (1) Light microscopic features associated with HPV infection and local cellular immune responses. (2) Indirect immunofluorescence detection of the following cell surface markers: HLA DR, alpha one antitrypsin, CD1, CD3, CD4, CD8, CD22. (3) Clinical response of AG warts to treatment. RESULTS: In pre-treatment biopsies only non specific indicators of HPV infection (acanthosis, 29/30 biopsies, and hyperkeratosis, 7/30 biopsies) were seen on light microscopy. Mononuclear cells were seen both throughout the upper dermis and centred around dermal blood vessels in 19/30 (63.3%) biopsies, and infiltrating into the epidermis in 12/30 (40%) biopsies. On indirect immunofluorescence CD3, CD8, CD4 antigen was detected on the surface of cells throughout the upper dermis in 24/29 (82.7%), 15/29 (51.7%), and 3/29 (10.3%), of biopsy specimens respectively. CD3 antigen, CD8 antigen and CD4 antigen was detected on the surface of cells infiltrating into the epidermis in 18/29 (62%), 7/29 (24.1%), and 6/29 (20.7%) of biopsy specimens respectively. CD1 antigen was seen on the surface of dendritic cells throughout the epidermis in all specimens; CD1 positive cells infiltrated into the upper dermis in 5/29 (17.2%). HLA DR was detected on the surface of dendritic cells throughout the epidermis in 22/29 (75.9%) of specimens, and on the surface of cells scattered both diffusely throughout the upper dermis and centred around dermal blood vessels in all specimens. Alpha one antitrypsin (A1AT) antigen was seen on the surface of cells in the upper dermis in 6/29 (20.7%) of biopsy specimens; no cells expressing CD22 surface antigen were seen. The nature of this local cellular immune response was not altered by treatment of nearby warts with either cryotherapy alone or cryotherapy plus systemic IFN alpha 2a, or related to the therapeutic outcome of these warts. CONCLUSIONS: (1) No convincing histological evidence of HPV infection was seen in epithelium surrounding AG warts. (2) A predominantly T cell-mediated immune response (the target of which is uncertain) was seen in this perilesional epithelium. (3) In the dosage regimens used in this study, treatment of AG warts with either systemic IFN alpha 2a plus cryotherapy or cryotherapy alone did not appear to augment localised cellular immune responses (against any presumed subclinical HPV infection) in epithelium surrounding AG warts.

Adolescent↗
PubMed1992

Laser safety primer outline for industrial/medical users.

Laser safety standards are detailed technical documents arising from the complexity of the different mechanisms, depending on the parameters of the laser beam, by which lasers interact with living tissue. As a result, their interpretation by non-expert laser users, who are concerned about safety issues, can cause many difficulties. Based on experience in advising industrial and medical laser users, we have developed a primer which (i) provides step-by-step guidance in the interpretation and use of the laser safety standards, and (ii) explains how to calculate the laser irradiance (on the retina or the skin) to which the user may be subjected in typical situations. A computer program has also been developed which, through a series of questions and answers, guides the user through the calculation of the maximum permissible exposure level and the nominal optical hazard distance for the application of interest. The overall package should be particularly useful to laser safety officers and users of lasers for research applications, as an independent check on safety calculations. It also provides a useful complement to the many worked examples in the laser safety standards.

Equipment Safety↗
PubMed1991

Enhanced intraspecific protoplast fusion in yeast.

Intraspecific hybrid production from the polyethylene glycol induced fusion of yeast protoplasts was greatly increased when calcium propionate was included as the source of the requisite Ca2+. The use of calcium propionate, as opposed to the more commonly employed calcium chloride, resulted in substantially greater yields of hybrids from intraspecific fusions of protoplasts of Saccharomyces cerevisiae and Candida albicans. It is postulated that the ability of calcium propionate to enhance the fusion frequency is due to the anion binding to the etheric oxygen of PEG and potentiating the fusogenicity of the polymer.

Acetates↗
PubMed1991

Avian myeloblastosis virus reverse transcriptase. Effect of glycerol on its hydrodynamic properties.

Although reverse transcriptase has been the subject of intensive investigation, minimal information is available regarding the physical properties of the enzyme. The basic hydrodynamic properties of avian myeloblastosis virus reverse transcriptase in solution were measured by both sedimentation velocity and equilibrium measurements in two buffer systems. In a 0.3 M potassium phosphate buffer system, pH 7.8, the enzyme sedimented as a homogenous particle with a sedimentation coefficient of (7.1 +/- 0.3) S with a weight-average molecular weight, Mw, of (1.52 +/- 0.05) x 10(5). Since the enzyme consists of an alpha and beta subunit of equal molar ratio with Mw of 6.3 x 10(4) and 9.4 x 10(4), respectively, it was concluded that the enzyme exists as an alpha beta heterodimer in this buffer system. In a Tris buffer system, pH 7.9, containing 0.46 M NaCl and 4% glycerol, the native enzyme also sedimented as a homogeneous particle with an apparent sedimentation coefficient of (10.1 +/- 0.5) S, without considering the effect of glycerol on solvent-protein interaction. Based on the results of Gekko and Timasheff (Gekko, K., and Timasheff, S. N. (1981) Biochemistry 20, 4667-4676) and the polarity of the enzyme, it was estimated that there is significant solvent-protein interaction even at 4% glycerol leading to a value of -0.06 g/g in the preferential solvent interaction parameter. When the solvent effect was taken into consideration, the value for s020,w increased from 10.1 to 11.9 S, implying that the native enzyme dimerizes in the presence of 4% glycerol. The combined results of gel filtration and sedimentation velocity showed that the dimerization of the enzyme to form (alpha beta)2 is favored at 20 degrees C with the alpha beta form predominating at 4 degrees C. The secondary structure of the reverse transcriptase was measured by circular dichroism. Results showed that the enzyme consists of (16 +/- 2)% alpha-helix, (24 +/- 2)% beta-sheet, (24 +/- 2)% beta-turn, and (36 +/- 4)% undefined structures.

Avian Myeloblastosis Virus↗
PubMed1991

Fine-needle aspiration in recurrent tonsillitis.

The incidence of tonsillitis that is unresponsive to penicillin therapy is leading to concern. This phenomenon has been linked to a change in the core tonsil bacteria, in particular beta-lactamase production. To date, the only way to identify the presence of these resistant microbes is at tonsillectomy. In this prospective study, we performed fine-needle tonsil aspiration in 34 patients (mean age, 7.6 years) before tonsillectomy. The bacteriologic nature of the aspirate was compared with that obtained from culturing the tonsillar surface (in situ) and core of the resected tonsils. The bacteriologic findings of the aspirate corresponded closely with those of the tonsil core (qualitative and quantitative comparison), while the superficial swab was of limited value in predicting the core bacteria. Based on this study, tonsil fine-needle aspiration may have a place in the treatment of recurrent tonsillitis.

Adolescent↗
PubMed1991

Effect of acylation stimulating protein on the triacylglycerol synthetic pathway of human adipose tissue.

Acylation stimulating protein (ASP) is a 14 kDa plasma protein which causes in vitro triacylglycerol synthesis in human adipocytes and fibroblasts to increase substantially. ASP was found to stimulate human adipose tissue microsomal glycerophosphate acyltransferase and diacylglycerol acyltransferase activities by 23% and 90%, respectively. However, phosphatidate phosphohydrolase activity showed no increase in activity, nor did microsomal acyl-CoA synthetase activity. Moreover, ASP did not decrease the apparent Km of diacylglycerol acyltransferase (DGAT), but rather increased its apparent Vmax suggesting direct interaction of ASP with DGAT.

Acyltransferases↗
PubMed1991

Subcorneal pustular dermatosis and IgA paraproteinaemia: response to both etretinate and PUVA.

A non-insulin dependent male diabetic is reported with subcorneal pustular dermatosis associated with intraepidermal IgA deposits and a benign IgA paraproteinaemia. Treatment with dapsone and etretinate was reasonably effective, but etretinate had to be discontinued due to the development of diffuse idiopathic skeletal hyperostosis. His subcorneal pustular dermatosis subsequently flared and was troublesome for 2 years until he was commenced on PUVA, with excellent response.

Aged↗
PubMed1991

A comparison of expression of surface-bound immunoglobulin E on antigen-presenting cells in cutaneous tissue between patients with allergic, irritant and atopic dermatitis.

The expression of surface-bound immunoglobulin E by dendritic cells within cutaneous tissue has been compared in atopic and contact dermatitis. 45 patients were recruited into 4 groups using clinical criteria and patch testing to a standard series of allergens: atopic (12 cases), allergic contact dermatitis (14 cases), irritant contact dermatitis (10 cases) and the control group (9 cases); using clinical criteria and patch testing to a standard series of allergens. Skin biopsies from each patient were analysed by the indirect immunofluorescence technique. This differentiated 3 patterns of cutaneous IgE distribution: (i) no detectable cutaneous IgE; (ii) detection of IgE solely within the dermis; (iii) detection of IgE within both epidermis and dermis. Detection of IgE within the epidermis was always associated with the presence of IgE within the dermis. In each case, IgE was surface-bound by dendritic cells. Immunoglobulin E was detected within both epidermis and dermis in skin biopsies from 8 (66.7%) atopic patients and 2 (20%) patients with irritant contact dermatitis. No other cases demonstrated IgE deposition within both the epidermis and dermis. Atopic patients were significantly more likely to have detectable IgE deposition, within both epidermis and dermis, than patients with contact dermatitis (allergic and irritant groups combined, p = 0.0011) or controls (p = 0.0049). This finding suggests that the demonstration of IgE within both epidermis and dermis supports a diagnosis of atopic dermatitis. It would therefore be of value in differentiating between atopic and contact dermatitis, where clinical diagnosis is in doubt.

Dendritic Cells↗
PubMed1991

Globus pharyngeus: long-term follow-up and prognostic factors.

A prospective trial of 80 patients with globus pharyngeus is reported. An in-depth analysis of the typical history at presentation is given. The average follow-up period was 27 months (range, 21 to 42 months). The asymptomatic rate at this interval was 25%, with a further 35% reporting a significant improvement in symptoms. Three independent factors were found to influence prognosis (p less than .05). These were sex, length of history at consultation, and the presence or absence of associated throat symptoms. Male patients having a history of the globus symptom for less than 3 months and not complaining of any associated throat symptoms had the best chance of becoming asymptomatic or symptomatically improved. The presence or absence of heartburn or its treatment had no bearing on outcome.

Adult↗
PubMed1991

Effects of ascorbic acid depletion and supplementation on periodontal health and subgingival microflora in humans.

This study describes the relationship between varying ascorbate intake, periodontal status, and subgingival microflora as part of a multidisciplinary investigation of ascorbic acid (AA) metabolism in young men housed for 13 weeks in a nutrition suite that provided controlled periods of ascorbic acid depletion and repletion. Twelve medically healthy non-smoking men, aged 25 to 43 years, ate a rotating four-day diet adequate in all nutrients except ascorbic acid. Following an initial baseline period during which the subjects received 250 mg AA/day, the subjects received 5 mg AA/day for a 32-day depletion period. Eight of the 12 subjects participated in a subsequent 56-day repletion period designed to replace the reduced body AA pool slowly. Plasma and leukocyte ascorbate levels, Plaque Index, Gingival Index, probing depths, and attachment level were monitored at the beginning and end of the depletion and repletion periods. Subgingival plaque samples were obtained and examined for selected organisms by indirect immunofluorescence microscopy. A uniform oral hygiene program was reinforced after each examination. Ascorbate concentrations in plasma and leukocytes responded rapidly to changes in vitamin C intake. There were no significant changes in plaque accumulation, probing pocket depth, or attachment level during the study. In contrast, gingival bleeding increased significantly after the period of AA depletion and returned to baseline values after the period of AA repletion. However, no relationship could be demonstrated between either the presence or proportion of target periodontal micro-organisms and measures of bleeding or ascorbate levels.

Actinomyces viscosus↗
PubMed1991

Radiological assessment of dysphagia in Parkinson's disease.

Videofluoroscopy was used to examine swallowing in 24 patients with Parkinson's disease and dysphagia. Motility patterns for liquids, semi-solids and solid foods were classified into oral, pharyngeal and oesophageal phases. Abnormalities in swallowing were demonstrated in 92% of patients in the oral phase, 54% in the pharyngeal phase and 8% in the oesophageal phase. Tracheal aspiration occurred in 46%. These abnormalities were more marked with liquids than with semi-solids or solids. Abnormalities of swallowing are common in Parkinsonian patients with dysphagia. Videofluoroscopy is the appropriate method of investigation.

Barium Sulfate↗
PubMed1991

Evidence of prenatal infection in the bottlenose dolphin (Tursiops truncatus) with the lungworm Halocercus lagenorhynchi (Nematoda: Pseudaliidae).

Adult lung nematodes identified as Halocercus lagenorhynchi were collected from the lungs of four Tursiops truncatus calves. The calves ranged in age from newborn to 3-wk-old and were found on both the Atlantic and Gulf coasts of Florida (USA). This finding suggests the possibility of a more cosmopolitan distribution of prenatal infection with lung nematodes in cetaceans than previously suspected.

Animals↗
PubMed1991

QA systems must balance functionality with data security.

Confidentiality of patient records has been a critical focus of automated clinical systems since their inception. The added dimension of quality assurance studies, however, greatly broadens the area of confidentiality and liability, heightening security concerns for quality-assurance professionals.

Confidentiality↗