Search PubMed⌕ Search

Biomedical subjects

H E Schaefer

Publications and source records attributed to H E Schaefer.

At least 145 records · Page 8Linked to original sources

The presence and significance of the Thomsen-Friedenreich antigen in mammary gland. II. Its topochemistry in normal, hyperplastic and carcinoma tissue of the breast.

Normal tissue as well as various benign and malignant lesions of the breast were histochemically examined for the presence of the Thomsen-Friedenreich (TF)-antigen. Fluorescein- or 3H-labelled peanut agglutinin was used for this purpose, a lectin that is known to have a high affinity for the TF-antigen. The occurrence of this TF-antigen seemed in all cases, even in the carcinoma lobulare in situ that is regarded as being derived from myoepithelial cells by some authors, to be associated with a secretory condition. Its presence (free and neuraminic acid covered) in normal, hyperplastic and malignant breast tissue, however, cannot be considered a specific tumour associated antigen as has been previously assumed. Furthermore the investigations have shown that the intensity of fluorescence for peanut agglutinin (PNA)-receptors was generally stronger in differentiated carcinomas than in undifferentiated carcinomas of the breast. The histochemical findings are discussed with regard to diagnostical and immunotherapeutical aspects.

Antigens, Neoplasm↗

Demonstration of human apolipoprotien A in isolated mucosal cells from small intestine and isolated hepatocytes.

Isolated mucosal cells from the human jejunum and stomach, cryostat sections from the jejunum, isolated parenchymal liver cells and lymphocytes were investigated for the presence of apolipoprotien A (apoA). Antisera against purified human apoA-I and apoA-II were raised in rabbits and conjugated with fluorescein-isothiocyanate (FITC). Mucosal cells from jejunum and stomach were isolated with pronase from tissue obtained from operated patients. ApoA-I and apoA-II could be demonstrated in isolated mucosal cells as well as in cryostat sections from the jejunum. The fluorescence pattern in isolated jejunal cells was coarse granular. In the radial gel diffusion test the homogenate from mucosal cells of jejunum showed a single precipitation line with anti-apoA-I and with anti-apoA-II, respectively. The reaction was more intensive with anti-apoA-I than with anti-apoA-II. Isolated gastric cells were negative for apoA. Hepatocytes incubated with FITC anti-apoA-I showed a fine granular fluorescence pattern in the cytoplasm. Anti-apoA-II did not react with hepatocytes. There was no evidence for an in vivo fixation of serum-apoA at the surface of isolated mucosal cells from jejunum or isolated hepatocytes. The results support the hypotheses that in man apoA is synthesised in the epithelial cells of the small intestine and in parenchymal liver cells.

Apolipoproteins↗

Histochemical methods for the demonstration of Thomsen-Friedenreich antigen in cell suspensions and tissue sections.

1. Three different methods are described for the visualisation of the Thomsen-Friedenreich (TF) antigen on cell suspensions, formalin-fixed and paraffin embedded or frozen tissue sections: a) Rosette formation with chicken and sheep erythrocytes. b) Fluorescence-microscopy with fluorescein labelled peanut agglutinin. c) Autoradiography with 3H-labelled peanut agglutinin. 2. The TF antigen was shown, as far as presently investigated, to be exposed on various blood cells, glomerula of the kidney and normal mammary gland after neuraminidase treatment. Mammary gland was also shown to possess TF receptors without prior treatment with neuraminidase. 3. The exposure of this cryptantigen can be brought about by bacterial or viral neuraminidase and is followed by an antigen/antibody reaction, which can lead to possible pathological consequences.

Animals↗

Characterization of high density lipoproteins in patients heterozygous for Tangier disease.

In this study a large family group affectd with Tangier disease has been investigated. Besides two homozygous propositi, several heterozygous patients have been identified on the basis of quantitative measurements of high density lipoproteins and their constitutive polypeptides. By a variety of quantitative immunological methods, such as one-dimensional Laurell eletrophoresis, two-dimensional immunoelectrophoresis, and double-antibody radioimmunoassay, the total amount of apoprotein A-I and apoprotein A-I contained in the serum of heterozygous patients and the distribution of these A apoproteins among serum lipoproteins have been determined. The molar ration of apoprotein A-I and apoprotein A-II contained in high density lipoproteins of heterozygous patients did not significantly differ from that of control preparations, although the total mass of high density lipoproteins was reduced by approximately 50%. The elution profile of high density lipoproteins from agarose columns and their morphological appearance, as ascertained by electron microscopy, were similar to control preparations. In addition to the quantitative alterations of serum lipoproteins, lipid storage in histiocytes of the rectal mucosa obtained from heterozygous patients has been documented. It is concluded that patients heterozygous for Tangier disease have normal high density lipoproteins in circulation, the total mass of which is reduced by approximately 50%.

Apolipoproteins↗

Spontaneous variations in the cell population of a T-cell lymphoma during tissue culture and transplantation.

Immunologically induced T-cell lymphomas were kept for long period fo time in isotransplantation and in tissue culture. Initially, a certain number of cells within the tumor showed differentiation towards histiocytes. These disappeared completely after about the twentieth graft generation when the tumor changed toward a more atypical and more uniform neoplasm. That change was correlated with a decrease in transplantability, a limited growth in tissue culture, and a decrease in density of theta antigens on tumor cell membranes. While the original tumor and early grafts contained occasional C-type particles, these were never demonstrated in late tumor grafts. The possible implications of these changes are discussed.

Animals↗

[Cytochemical polymorphism of acid phosphatase in hairy cell leukemia].

In four cases of hairy cell leukemia a cytochemical polymorphism concerning acid phosphatase (AP) is evident. Any AP is lacking in all hairy cells of one case; only tartrate inhibitable AP is occurring in two cases, in another case tartrate resistant AP is found in high activity. Thus, the lack of tartrate resistant AP seems not to be an argument against hairy cell leukemia.

Acid Phosphatase↗