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Biomedical subjects

E Heyderman

Publications and source records attributed to E Heyderman.

At least 55 records · Page 3Linked to original sources
PubMed1983

Immunoperoxidase techniques: the deleterious effect of sodium azide on the activity of peroxidase conjugates.

The effect of including sodium azide as a bacteriostatic agent in solutions used to dilute antibodies conjugated with the enzyme horseradish peroxidase was examined. An enzyme-linked immunosorbent assay (ELISA) and an immunohistochemical method were used and both techniques demonstrated an inhibitory effect of sodium azide on the activity of the peroxidase conjugates. It is concluded that the use of sodium azide in solutions used to dilute peroxidase conjugates is to be avoided.

Antibodies↗
PubMed1982

Prognostic factors in clinical stage I non-seminomatous germ-cell tumours of the testis.

Prognostic factors have been studied in 59 men with clinical Stage I non-seminomatous germ-cell tumours of the testis (NSGCTT) seen at the Royal Marsden Hospital between 1973 and 1978. Fourteen of the patients relapsed, and 45 have remained continuously disease-free. Two factors were identified which showed a significant correlation with relapse following radiotherapy: local extent of the primary tumour, and rate of decline of serum alpha-foetoprotein (AFP) and beta-human chorionic gonadotrophin (hCG) levels following orchidectomy. High serum marker levels at the time of referral after orchidectomy were not prognostically significant per se. The presence of tissue-associated hCG in the primary tumour was not prognostically significant. The results were compared with histology and pathological stage of the primary tumour in patients presenting with lung metastases but no clinical evidence of lymph-node disease. Embryonal carcinoma was more commonly associated with a locally invasive primary tumour and with extralymphatic spread than was teratocarcinoma.

Adolescent↗
PubMed1982

Biological markers in lung cancer: an immunocytochemical approach.

In oat cell (small cell) carcinoma and, to some extent, in other histological types of lung cancer, improved forms of treatment have resulted in prolongation of survival and even cure. Progress is hampered by the lack of reliable biochemical markers such as those which have completely changed the management and outlook in testicular and gestational carcinoma. Carcinoembryonic antigen (CEA) has been of some value. Raised circulating levels of calcitonin and of adrenocorticotropic hormone (ACTH) are found in many patients with lung cancer but have not proved as useful for monitoring disease progression. It is probable that since lung tumors form a heterogeneous population, production of markers varies with histological type. Our approach has been to affinity purify those polyclonal antisera to potential lung tumor markers which are not yet available as monoclonal hybridoma antibodies and to examine 10 representative resection specimens of each of the four common carcinoma types--squamous, adeno-, large cell, and small cell using an indirect immunoperoxidase localization technique on formalin-fixed paraffin-embedded sections. Substances localized included CEA, epithelial membrane antigen, calcitonin, alpha and beta subunits of human chorionic gonadotropin, and human placental lactogen.

Carcinoembryonic Antigen↗
PubMed1981

Alkaline phosphatase for immunocytochemical labelling: problems with endogenous enzyme activity.

Alkaline phosphatase may be used as a label for immunocytochemistry and can be demonstrated in tissue sections using the single step naphthol phosphate method. Endogenous enzyme activity may not be destroyed by fixation in formalin, formol alcohol, Carnoy's or Baker's solutions and should be inhibited before results are assessed. Either Bouin's solution or periodic acid followed by potassium borohydride are satisfactory inhibitor and do not adversely affect immunocytochemical results.

Acetates↗
PubMed1981

Hypothesis: when is a seminoma not a seminoma?

A xenograft line, HX 53, has been established in immune-suppressed mice from a specimen of a lymph node metastasis in a patient with a histological diagnosis of seminoma but with markedly raised circulating levels of alpha-fetoprotein. Histological, immunocytochemical, and ultrastructural studies of this xenograft line have suggested that a solid variant of yolk sac carcinoma may exist, which morphologically resembles seminoma, or that a continuum of differentiation exists between seminoma and yolk sac carcinoma.

Adult↗
PubMed1981

Immunoperoxidase localisation of human placental lactogen: a marker for the placental origin of the giant cells in 'syncytial endometritis' of pregnancy.

One hundred endometrial biopsies of various histological patterns, and material from 10 tubal pregnancies together with their associated uterine decidua, were examined for the presence of human placental lactogen using affinity-purified first and second antibodies and an indirect immunoperoxidase technique. Positive cells in endometrial curettings were seen only in association with an intrauterine pregnancy and morphologically resembled syncytiotrophoblast. Decidua associated with tubal pregnancy, pseudodecidua in progestogen-treated patients, and proliferative, secretory, and basal endometria were all negative. An immunoperoxidase stain for human placental lactogen is a useful marker for intrauterine pregnancy and supports the placental origin of the syncytial giant cells in so-called 'syncytial endometritis'. The technique is of potential value in those endometrial biopsies where pregnancy is suspected but no villi are seen.

Endometrium↗
PubMed1979

A comparison of the ability of beta-galactosidase and horseradish peroxidase enzyme-antibody conjugates to detect specific antibodies.

The ability of two different enzyme-antibody conjugates to detect specific antibodies has been compared. beta-Galactosidase was conjugated to antibodies raised against rabbit Fc fragments using m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS). Horseradish peroxidase (HRP) was conjugated to part of the same batch of antibodies using the periodate method. The beta-galactosidase and HRP labels enabled detection of approximately 8 fmoles and 4 fmoles respectively of human growth hormone (HGH) antibodies, when their enzyme activities were measured spectrophotometrically. The detection limit of the beta-galactosidase label was increased 4-fold when a fluorimetric detection system was employed.

Animals↗
PubMed1979

A human testicular teratoma serially transplanted in immune-deprived mice.

Serial transplantation of an HCG-producing human testicular teratoma in immune-deprived mice is described. The xenografted tumour was compared to the tumour of origin in histology, immunohistochemistry (using an immune peroxidase technique to localize HCG) autoradiography, marker production and growth rate. It is concluded that the xenograft retained the characteristics of the original tumour with the exception of a reduction in HCG-producing elements at transplantation beyond 5 serial passages.

Adult↗
PubMed1979

A new antigen on the epithelial membrane: its immunoperoxidase localisation in normal and neoplastic tissue.

Using antisera raised against defatted human cream we have demonstrated a new antigen on the epithelial membrane. An indirect immunoperoxidase technique on routinely processed histological sections was used, and we describe results which show that this antigen has a widespread but highly selective distribution, being apparently localised to membranes that have a secretory function. The antigen is carried by a variety of adenocarcinomas, suggesting that its localisation may have a role in the diagnosis and differential diagnosis of malignant disease.

Antigens↗