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Biomedical subjects

M Egan

Publications and source records attributed to M Egan.

At least 73 records · Page 4Linked to original sources
PubMed1988

Localization of salivary amylase and epithelial membrane antigen in salivary gland tumours by means of immunoperoxidase and immunogold-silver techniques.

A series of 87 salivary glands was examined using an immunogold-silver technique for salivary gland amylase (SGA) and epithelial membrane antigen (EMA) and an indirect immunoperoxidase technique for both antigens. The specimens comprised 21 pleomorphic adenomas, 3 monomorphic adenomas, 25 adenolymphomas, 5 mucoepidermoid carcinomas, 3 acinic cell tumours, 8 adenoid cystic carcinomas, 2 adenocarcinomas and 8 undifferentiated carcinomas. In addition 5 normal salivary glands and 6 salivary glands showing benign lymphoepithelial lesions were included.

Adenolymphoma↗
PubMed1988

Intraepithelial neoplasia, human papilloma virus infection and argyrophilic nucleoprotein in cervical epithelium.

A silver colloid technique was applied to 50 colposcopic biopsies of cervix. These comprised nine cases of wart virus infection of the cervix, 11 cases of cervical intraepithelial neoplasia (CIN) I, nine cases of CIN II, eight cases of CIN III, seven normal biopsies and six cases showing only incomplete squamous metaplasia. The mean numbers of argyrophilic nucleolar organizer regions (AgNORS) increased from CIN I to CIN III. Statistically significant differences for AgNORs were found in comparisons between CIN III, normal basal cells, human papilloma virus-infected basal cells and incomplete squamous metaplasia, and in comparisons between normal basal cells and human papilloma virus-infected basal cells. CIN III could be distinguished from incomplete squamous metaplasia and from basal cells and from human papilloma virus-infected basal cells. The latter could be distinguished from normal basal cells on the basis of their AgNORs. It is suggested that this simple technique is diagnostically useful and has considerable clinicopathological potential in cervical pathology and cytology.

Epithelium↗
PubMed1988

Comparative study of the degree of differentiation of neuroblastoma and mean numbers of nucleolar organiser regions.

Twenty confirmed cases of childhood neuroblastoma diagnosed over six years were reviewed and classified according to the subtyping proposed by Shimada et al. The tumours were stained using a silver colloid method for nucleolar organiser regions (NORs), and the mean number of NORs for every 200 cells was calculated. The correlation between the mean number of NORs and histology and survival was studied. There was a significant correlation between the mean numbers of NORs and differentiation, and with the mitosis-karyorrhexis index (MKI) in the stroma poor group (p = 0.01-0.001). A trend to increased survival with decreased numbers of NORs was observed in the study group as a whole (rank order of correlation = -0.57, p = 0.05-0.02). It is suggested that mean number of NORs is of prognostic value in neuroblastomas.

Cell Count↗
PubMed1988

Benign cystic mesothelioma of the peritoneum: immunohistochemical and ultrastructural features in a child.

Benign cystic mesothelioma of the peritoneum is a well-defined but rare entity. A total of 35 instances have been reported, almost all in adults, the majority females. Cystic mesotheliomas have, until recently, been labeled cystic lymphangiomas or lymphohemangiomas. We report the case of a 14-year-old boy who, despite only subtotal resection of his abdominal mass, is well and recurrence free 9 months after surgery. The role of immunohistochemistry and electron microscopy in diagnosis is emphasized.

Adolescent↗
PubMed1988

Ectopic production of beta-human chorionic gonadotropin by inverted papilloma of the nose.

A series of 19 inverted papillomas (transitional type or Schneiderian papillomas) of the nose were examined using an immunogold-silver (IGS) technique and an indirect immunoperoxidase technique. We demonstrated beta-HCG production in all 19 specimens with both methods. The staining demonstrated by the IGS technique was of a greater intensity and in a larger number of cells than that observed by the indirect immunoperoxidase method.

Adult↗
PubMed1985

Electrophysiological interactions between haloperidol and reduced haloperidol, and dopamine, norepinephrine and phencyclidine in rat brain.

Haloperidol and its metabolite, reduced haloperidol, were compared as antagonists of catecholaminergic neurotransmission in central nervous system of the rat. Agonists and antagonists were applied from multibarrelled micropipettes, which were also used to record extracellularly the effects of these substances on neuronal discharge. Haloperidol antagonized dopaminergic inhibition of caudate neurons and inhibition of cerebellar Purkinje neurons induced by noradrenaline, whereas reduced haloperidol was an ineffective antagonist. Phencyclidine, which is an indirect dopaminergic agonist in the caudate, caused inhibition of the discharges of caudate neurons resembling that induced by dopamine itself. These indirect effects of phencyclidine were also antagonized by haloperidol but not by reduced haloperidol. The data suggest that the metabolite, reduced haloperidol, is not an effective neuroleptic drug in the central nervous system.

Animals↗
PubMed1985

The site of commencement of retinal maturation in the rabbit.

In the developing retina of the rabbit the ganglion cell layer can first be identified between E(embryonic day) 20 and 24, but the regional variations found in the adult retina, particularly the visual streak, are not well developed until shortly before birth. At about E31, the last day of gestation, the laminar structure of the retina begins to mature, cytogenesis begins to cease and the outer plexiform layer starts to form. These processes commence in far temporal retina, at or near the site of the area centralis, and spread preferentially along the visual streak.

Animals↗
PubMed1983

Relationship between incorporation of 9-beta-D-arabinofuranosyladenine in L 1210 DNA and cytotoxicity.

We have used cesium sulfate density gradient centrifugation to monitor the incorporation of 9-beta-D-arabinofuranosyladenine (ara-A) into L1210 cellular nucleic acids. The results demonstrate the specific incorporation of ara-A in L1210 DNA. We have also found a highly significant relationship between the formation of ara-A incorporated into DNA and loss of clonogenic survival. This relationship was maintained when using ara-A in the presence of the adenosine deaminase inhibitor deoxycoformycin. Furthermore, treatment with increasing concentrations of ara-A resulted in a greater proportion of ara-A residues at the 3'-terminus, consistent with this agent providing a poor primer terminus for elongating DNA strands. These findings are similar to those obtained previously with 1-beta-D-arabinofuranosylcytosine and suggest that the incorporation of arabinofuranosyl derivatives in DNA is one mechanism responsible for cell lethality.

Animals↗
PubMed1981

Differentiation antigens expressed by epithelial cells in the lactating breast are also detectable in breast cancers.

Two monoclonal antibodies, 3.14.A3 and 1.10.F3, raised against a delipidated preparation of the human milk fat globule and characterized as epithelium-specific (Taylor-papadimitriou et al., 1981) were assayed histologically, by an indirect immunoperoxidase technique, against formalin-fixed, paraffin-embedded, normal and tumour tissue sections, in order to establish their in vivo specificity. Both antibodies bound to less than 10% of the alveoli and ducts in the resting breast, but bound to all areas of alveoli, ducts and secretion in the lactating breast. Binding was to the luminal surface of the alveolar and ductal epithelium. Antibody 3.14.A3 showed positive reactions with each of 20 primary breast carcinomas tested, and with metastatic lesions in lymph nodes from six of these. Antibody 1.10.F3 also reacted with most of the primary carcinomas but not with those of the mucoid type nor with metastatic lesions in lymph nodes. When tested against a variety of normal tissues, 1.10.F3 bound only to the luminal epithelial surface of classically defined exocrine glands, to their associated ducts and to the collecting tubules of kidney and bronchioles of the lung. 3.14.A3 showed a similar pattern of binding to 1.10.F3 but also bound to sweat glands, the alveolar epithelium of lung and the luminal epithelium of the ductuli efferentes of the epididymis. The only tumours, other than breast, showing a positive reaction with the antibodies were adenocarcinomas of the lung, uterus and ovary.

Antibodies, Monoclonal↗
PubMed1980

Reduced chronic hemolysis during high-dose vitamin E administration in Mediterranean-type glucose-6-phosphate dehydrogenase deficiency.

The observation that high-dose oral vitamin E supplementation (800 IU per day) improved red-cell survival in two rare disorders associated with increased red-cell susceptibility to oxidative stress prompted a similar trial in 23 patients with Mediterranean glucose-6-phosphate dehydrogenase (G6PD) deficiency. Three months of vitamin E administration resulted in decreased chronic hemolysis as evidenced by improved red-cell life span (P less than 0.025), with an improvement in red-cell half-life from 22.9 +/- 0.7 days to 25.1 +/- 0.6 days (mean +/- S.E.M.), increased hemoglobin concentration (P less than 0.001), and decreased reticulocytosis (P less than 0.001) as compared with base-line values. Evaluation after one year of vitamin E administration demonstrated sustained improvement in all these indexes. Controlled clinical trials of vitamin E supplementation may be warranted to examine its efficacy in ameliorating acute hemolytic crises or in reducing morbidity from neonatal jaundice in this relatively common genetic disorder.

Administration, Oral↗