Mated CD-1 mice were exposed to 20-kHz sawtooth magnetic fields similar to those associated with video display terminals (VDT). Four groups of animals were continuously exposed from day 1 to day 18 of pregnancy to field strengths of 0, 3.6, 17, or 200 microT. There were no less than 185 mated dams in each exposure group. On day 18, the dams were sacrificed and assessed for weight gain and pregnancy. The litters were evaluated for numbers of implantations, fetal deaths and resorptions, gross external, visceral and skeletal malformations, and fetal weights. There were no less than 140 pregnant females in each group, and there were no significant differences between any of the exposure groups and the sham group (0 microT) for any of the end points. The results of this study do not support the hypothesis that the 20-kHz VLF magnetic fields associated with video display terminals are teratogenic in mammals.

Abnormalities, Radiation-Induced↗

PubMed1992

The correlation between clinical diagnosis of knee pathology and findings at arthroscopy.

175 patients referred for arthroscopy were studied prospectively to assess the accuracy of clinical examination supplemented by standard radiology in the evaluation of knee symptoms. Clinical diagnosis of medial meniscal tears was inaccurate while greater confidence could be placed in the diagnosis of anterior cruciate ligament and lateral meniscus tears. Clinical accuracy rates could be improved if patients with minimal symptoms were excluded from arthroscopy examination.

Anterior Cruciate Ligament Injuries↗

PubMed1992

Melioidosis and laboratory safety.

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Bacteriological Techniques↗

PubMed1992

Multiple lentigines, myxoid tumours and endocrine overactivity; four cases of Carney's complex.

Four patients with Carney's complex, one sporadic and three familial, are described. The sporadic case was a young male with centrofacial lentigines, who developed cyclical Cushing's syndrome secondary to bilateral pigmented nodular adrenocortical disease, two separate left atrial myxomas, and buccal mucosal myxomas. The three familial cases, who all had varying degrees of centrofacial/mucosal lentigines and cutaneous myxoid tumours, were a woman with myxoid mammary fibroadenomatosis and a left atrial myxoma, her daughter who developed a prolactin-secreting pituitary adenoma, and her son who had bilateral large-cell calcified Sertoli cell testicular tumours, and an axillary psammomatous melanotic schwannoma.

Adenoma↗

PubMed1992

Erythropoietic protoporphyria, transfusion therapy and liver disease.

A 28-year-old man who had suffered from erythropoietic protoporphyria since infancy was referred because of worsening photosensitivity. Conventional therapy with beta-carotene, terfenadine and topical sunscreens was ineffective or not tolerated, and he was treated with transfusions of washed packed cells. Unexpectedly, his photosensitivity deteriorated further, his whole blood protoporphyrin levels doubled and he developed abnormal liver function tests. This is the first report of such an adverse response to blood transfusion therapy for erythropoietic protoporphyria and may have been related to subclinical hepatitis or the increased iron load associated with blood transfusion.

Adult↗

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↗

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

The pencil grip technique for middle ear effusion aspiration.

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Ear, Middle↗