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Biomedical subjects

A Poschmann

Publications and source records attributed to A Poschmann.

At least 37 records · Page 2Linked to original sources
PubMed1986

The occurrence of blood group substances (A, B, H, Le-a, Le-b) in salivary glands and salivary gland tumors. An immunohistochemical investigation.

The distribution of blood group substances A, B, H, Le-a and Le-b in normal and neoplastic salivary gland tissue was evaluated by means of immunohistochemistry. The serological ABH blood group status of one third of the patients was known. Lewis blood group and secretory status were not known. In normal tissue, expression of blood group antigens corresponded to the serological blood group. Blood group substance H was present in almost every gland, regardless of the serological blood group. In submandibular glands, Le-b was rather selective for mucous acini. In tumors, a relationship of blood group expression to a glandular pattern and a high differentiation could be observed. Blood group substances were expressed at a high level in benign and highly differentiated malignant tumors. In poorly differentiated malignant tumors, they were mostly absent. Blood group expression evaluation could be of value in establishing the level of functional differentiation in salivary gland tumors.

ABO Blood-Group System↗
PubMed1985

Autoimmune haemolytic anaemia: recent advances in pathogenesis, diagnosis and treatment.

The diagnosis and management of patients with autoimmune haemolytic anaemia demands knowledge of various aspects of both clinical and laboratory medicine. There is an apparent gap of communication between the serologist and the clinical physician due to the high specialization of both. The purpose of this annotation is to close some of these gaps by relating the serological data to the diagnosis, severity of disease, treatment, and prognosis.

Adrenal Cortex Hormones↗
PubMed1985

Study on the carbohydrate specificity of antibodies formed in rabbits to synthetic glycoproteins with the carbohydrate structure of asialo-glycophorin A.

Antibodies formed in rabbits to synthetic glycoproteins with the disaccharide structure beta-D-Gal-(1-3)-D-GalNAc, the carbohydrate moiety of desialylated glycophorin A, were investigated for their carbohydrate specificity by hemagglutination techniques and radioimmunoassay. The synthetic disaccharide was coupled to human serum albumin as carrier protein using different spacer groups and different configurations of the disaccharide spacer linkage. Radioimmunological inhibition experiments using a number of different derivatives of the carbohydrate group as inhibitors revealed a significant specificity of the antibodies for the oligosaccharide structure. However, the nature of the conjugation of the disaccharide to the carrier protein was found to be important for defining the specificity of the antibodies. Furthermore the arrangement of the hapten groups in the synthetic antigen had an important influence on the antigen-antibody reaction. No cross-reactions were observed between asialo-glycophorin A and the different synthetic antigens. Synthetic antigens provide a valuable tool for generating carbohydrate-specific antibodies. However, if the synthetic hapten molecule is small compared to the combining site of antibodies, the specificity of the immunological reaction is significantly influenced by the synthetic spacer arm or even the carrier protein.

Animals↗
PubMed1985

Use of synthetic antigens with the carbohydrate structure of asialoglycophorin A for the specification of Thomsen-Friedenreich antibodies.

The panagglutination phenomenon described by Thomsen and Friedenreich (TF) is due to the reaction of naturally occurring TF-antibodies with the carbohydrate group beta-D-Gal-(1-3)-D-GalNAc of desialylated glycophorin A, the major glycoprotein component of the erythrocyte membrane. The specificity of human TF-antibodies reacting with this disaccharide was investigated by hemagglutination inhibition assay and radioimmunoassay using various synthetic oligosaccharides and neoglycoproteins as well as asialoglycophorin A. The results indicate that TF-antibodies represent a heterogeneous mixture of carbohydrate-specific antibodies. The disaccharide beta-D-Gal-(1-3)-D-GalNAc is the common structure recognized by all TF-antibodies. However, the conjugation mode of the carbohydrate to the carrier protein is important for defining the specificity of different subpopulations of TF-antibodies. The immunological reaction depends on the configuration of the glycosidical linkage as well as on the chemical nature of the aglycon, which is coupled to the disaccharide. These findings suggest that the heterogeneity of natural TF-antigens is due to the wide distribution of the carbohydrate structure beta-D-Gal-(1-3)-D-GalNAc. The characterization of TF- or TF-like antibodies directed to particular natural TF-antigens (e.g. asialoglycophorin A, tumor TF-antigens, glycolipids, bacterial antigens) requires TF-analogues, which contain the additional molecular regions together with the TF-disaccharide. These structures, apart from the TF-hapten, are obviously important for defining the immunodeterminant group of TF-antigens of different origin.

Antibodies↗
PubMed1985

[Prenatal diagnosis and therapy of hemolytic disease of the newborn].

From 1966 to 1983 a total of 586 intra-uterine fetal transfusions on 268 fetuses suffering from severe Rh-erythroblastosis were performed at the Hamburg university hospital. 149 (56%) fetuses survived. 29% of 268 fetuses exhibited ascitic fluid at the beginning of therapy. The survival rate improved to 63% in the last five years. The diagnostic and therapeutic procedures are explained in detail. The amniotic fluid analysis has been improved. In addition to Rh-antibodies, it is important to detect other blood group antibodies such as anti-Jk(a) and anti-Fy(a), that can diminish the survival rate of the donor erythrocytes in the fetus.

Amniotic Fluid↗
PubMed1984

Detection of metastatic breast carcinoma cells by immunofluorescent demonstration of Thomsen-Friedenreich antigen.

The Thomsen-Friedenreich antigen (TF-antigen), known as a precursor of the MN-blood-group system, has been suggested as a tumor-associated antigen of breast adenocarcinoma. In order to evaluate the TF-antigen as a tool in the histochemical detection of micrometastases, cryostat sections of 25 breast biopsies and 30 regionary lymph nodes were investigated. The study used a sensitive method for the fluorescent staining of the determining terminal disaccharide sequence of asialoglycophorin A by application of peanut agglutinin (PNA) and fluoresceinisothiocyanate-labeled F(ab')2 fragments of monospecific anti-PNA from rabbits. PNA binding was observed in 91% of the sections of predominantly ductal mammary carcinomas. In normal tissues and hyperplastic lesions, staining patterns were markedly different from that of malignant breast cells, and were confined to secretory glycoproteins. Lymph nodes, with histologically confirmed metastases of mammary carcinomas, showed specific PNA binding in the cytoplasm of tumor cells in 75% of cases. Even single malignant cells were demonstrable, which were not recognized at first by routine light microscopy. Fluorescent staining of lymph nodes, which were tumor-free in repeated histologic examinations, was confined to clearly diagnosible histiocytes in 3 of 15 cases. A sensitive indirect immunofluorescent technique demonstrating PNA binding is proposed to be of considerable value for the detection of single metastatic adenocarcinoma cells of the human breast.

Adenocarcinoma↗
PubMed1980

Rhesus incompatibility and aplastic anemia as the consequence of split chimerism after bone-marrow transplantation for severe combined immunodeficiency.

A patient with severe combined immunodeficiency received three transplants of bone marrow from the HLA-B- and -D-identical mother. The first transplantation led to a severe graft-versus-host reaction followed by immunological reconstitution. A split chimerism was found with engraftment only of the maternal lymphocytes. Five months after the transplantation an autoimmune hemolytic anemia was observed which was due to rhesus incompatibility as well as polyspecific antibodies. At the same time agranulocytosis developed and 9 mth after the first transplantation the child suffered from aplastic anemia. Two further attempts failed to engraft the maternal hematopoiesis. The child died during the treatment with cyclophosphamide as conditioning for a third transplantation.

Agranulocytosis↗
PubMed1980

[Small bowel stenoses as a consequence of intrauterine transfusion (author's transl)].

An infant is reported who, because of Rhesus incompatibility, required 4 antenatal blood transfusions. At the last of these transfusions performed during the 30th week of pregnancy, the catheter could not be removed and was left in the foetus's abdomen. Two weeks later, spontaneous delivery of an 1820 gm. male infant resulted. He had to be operated on on the 2nd day of life because of small bowel atresia, which was caused by two severe intestinal strictures which had been produced by the catheter. Following removal of the catheter and resection of the strictures, the post-operative course was essentially uneventful.

Adult↗
PubMed1977

'VA', a new type of erythrocyte polyagglutination characterized by depressed H receptors and associated with hemolytic anemia. II. Observations by immunofluorescence, electron microscopy, cell electrophoresis and Biochemistry.

With help of immunoflorescence, best with anti-AHP from Helix pomatia, a stippled structure could be demonstrated on the patient"s red blood cells. Thus an "A-like" receptor could be detected on the erythrocyte membrane of this group O patient. The reactive antigen was proved not to be a crypt antigen exposed by the action of neuraminidase. The same stippled fluorescence with antiAhp was observed on the red blood cells of a patient suffering from hemolytic anemia induced by influnza A2 virus. In this case this virus was shown not to be responsible for polyagglutination. No virus or microorganism could be isolated from the patient"s blood. Also by immunofluorescence the weak expression of the H antigen could be demonstrated with an extract of Evonymus europaeus. Electron microscopy of erythrocytes was normal. The neuraminic acid content and the electrophoretic mobility were found to be decreased to a minor degree. No distinct cell populations could be observed.

ABO Blood-Group System↗