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Biomedical subjects

H Müller

Publications and source records attributed to H Müller.

At least 379 records · Page 21Linked to original sources
PubMed1992

[Tumor proliferation, MDR phenotype and tumor associated t-lymphocytes in non-Hodgkin's lymphomas].

In this study we examined the P170-expression (mdr-phenotype) in 42 non-Hodgkin's Lymphomas with variant entities immunohistochemically with the mab JSB1. The mdr-phenotype was related to the tumor proliferation as measured by Ki67-expression and AgNOR numbers. Furthermore the mdr-phenotype was related to the tumor associated T-lymphocytes. The mdr-phenotype showed no relation to histological type and the proliferation of the tumor. There was a positive correlation between the mdr-phenotype and CD2-reactive lymphocytes. There was also a significant positive correlation between CD4-reactive lymphocytes and the mean number of AgNOR's. Possibly P170-expression and proliferation of the tumor cells have a lymphotactic effect on T-lymphocytes. The latter could promote tumor progression by means of paracrine mechanisms.

CD4 Antigens↗
PubMed1992

[Human mammary carcinoma. A model for the relationship between tumor proliferation, tumor-associate macrophages, and prognostic factors].

As compared with the lymphatic system, the mononuclear phagocyte system (MPS) represents the older defense system in the course of evolution. Organisms with defective or with no lymphocytic function are able to live for a certain time while metazoa cannot develop and exist without cells capable of phagocytosis. It is known that up to 80% of the mass of malignant experimental tumors may consist of macrophages. The biological relevance of these tumor-associated macrophages (TAM), however, is contested to date. Besides well-known tasks in specific and non-specific defense, the cells of the MPS possess nutritive functions. The different functions of TAM have been essentially examined in animal experiments in vivo and in vitro up to now. These studies have shown, e.g., that TAM of different phenotypes to some extent are assigned to different functions and that each tumor or tumor cell line has a specific TAM pattern. The available number of monoclonal antibodies (MAB) able to recognize different groups of human macrophages has only increased in the recent past. This also provided evidence of the phenotypic heterogeneity of macrophages in the human system. On the other hand, there is little knowledge to date of the possible biological cause of the presence of numerous macrophages also in the stroma of malignant tumors in man and on the functional relevance of particular macrophage phenotypes. In the present studies, the phenotypic pattern of tumor-associated cells was examined by immunohistochemistry in the model of human mammary carcinoma, using 18 monoclonal antibodies (Ki-M1-8, Leu-M1-3, Leu-M5, EBM11, CD1, anti-transferrin receptor [TFR], anti-MHC I, anti-MHC II or anti HLA-DR) and one polyclonal antibody (anti protein-S100). The first part of the study contains a semiquantitative evaluation of 216 cases of mammary carcinoma. The analytical results are correlated with established prognostic factors available in the case of malignant tumors in general and in that of mammary carcinomas in particular (age, menopausal status of patients, axillary lymph node and estrogen/progesterone receptor status, size of tumor, tumor type according to WHO, degree of malignancy according to histopathological and nuclear grading). As tumor parameters of absolute biological relevance, proliferating activity (Ki67) and MHC phenotype of tumor cells and amount or types of tumor-associated lymphocytes (TAL) are examined in order to analyze their correlation with prognostic factors and their importance in the tumor-macrophage system.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibody-Dependent Cell Cytotoxicity↗
PubMed1992

[New methods for diagnosing infection in pregnancy].

Maternal infections during pregnancy are of special relevance because of the risk of transmission to the fetus. Besides serological methods of diagnosing acute maternal infection, new approaches to assess fetal involvement have been made by invasive procedures, such as ultrasound-guided fetal blood sampling or amniocentesis. The most relevant infections in pregnancy are briefly reviewed with their incidence, consequences of fetal infection, and standard diagnostic procedures. Immunological methods are handicapped by the immaturity of the fetal immune system; direct culture is complicated and time-consuming. The application of molecular biological methods to directly identify the RNA- or DNA-sequences of the infectious agent may be an alternative. Two methods, polymerase-chain-reaction (PCR) and in-situ hybridization (ISH) are explained. Broad clinical use is still hindered by problems in specificity and quantitative accuracy. Nevertheless, successful diagnosis of most of the relevant infections in pregnancy by these molecular biological methods, is published, and discussed in a review of the recent literature.

Cytomegalovirus Infections↗
PubMed1992

[The immunization of pheasants against Newcastle disease].

ND-Adsorbatvakzine "Dessau" and Lasovak are well effective and tolerated in pheasants as immuno-prophylactic methods against Newcastle disease infection. Lasovak produces higher titres of antibodies and better rates of protection. The antibodies are created quicker too and reduced more slowly. There is no correlation between the average of antibody level and rate of protection after experimental infection. Even if antibodies are not demonstrable in hemagglutination inhibition test there is still existing a satisfactory protection. After two vaccinations in the age of chickens in 3 to 4 weeks interval and repetition after always 16 weeks pheasants can be protected effectively for the rearing and breeding seasons.

Animals↗
PubMed1992

[HIV detection in the bone transplant with polymerase chain reaction].

In trauma surgery, bone transplantation was needed in nearly 15% of all operations for reconstruction of defects. A high risk of viral infection remains in transplantation, however, cocultivation procedures have shown that human immunodeficiency virus (HIV-1) resides in bone of HIV-infected persons. Safety guidelines for running bone banks were not always easy to follow, and physical or chemical procedures applied for disinfection failed to inactivate HIV-1. In the present study we show that the polymerase chain reaction technique is an appropriate and sensitive means of detecting the HIV-1 genome in bone material prior to transplantation and-used in this way-can help to diminish the risk of HIV-1 transmission via bone transplantation.

Bone Transplantation↗
PubMed1992

[Tumor diseases in families of 600 breast cancer patients with special reference to familial adenocarcinomatosis and the Li-Fraumeni-/SBLA syndrome].

In some families breast cancer aggregates as the predominant site-specific neoplasia and in others in association with defined malignancies. In the case of familial adenocarcinomatous (Lynch II-syndrome) it occurs together mainly with colorectal and endometrial carcinoma whereas in the case of the Li-Fraumeni/SBLA-syndrome it belongs to a wider spectrum including sarcoma, brain tumors, lung and laryngeal cancer, leukaemia and adrenocortical carcinoma. The occurrence of these malignancies is reported as they were observed in the families of 600 women suffering from breast cancer.

Adenocarcinoma↗
PubMed1992

[Diabetes and pregnancy--optimal management].

Current classification, diagnostic and therapeutic guidelines of diabetes in pregnancy are briefly reviewed in this paper. Obstetricians mainly are confronted with the insulin-dependent diabetic (IDDM) prior to conception and during pregnancy. Intensive interdisciplinary co-operation is considered a prerequisite for treatment of the diabetic patient planning or carrying a pregnancy. The following subspecialties should work together in diabetic pregnant care: Reproductive Medicine incl. high-level endocrinological diagnostics, Diabetology with a teaching facility, and--within a perinatal center--an obstetric and neonatal department experienced in diabetic care. Preconceptional metabolic adjustment as well as surveillance of fetal and maternal condition during the first trimester of pregnancy are considered the mainstay in diabetic patient's care. Possible complications of diabetic pregnancy are described. Only in rare cases, pregnancy is contraindicated because of retino- or nephropathy. The screening program for gestational diabetes is based upon the patient's history, fasting-blood-glucose-levels, 50-g-oral-glucose-tolerance-test (OGTT) and a 24-h-blood-glucose-profile. Measurement of insulin levels in amniotic fluid are recommended for cases that remain yet undiagnosed.

Diabetes Mellitus, Type 1↗
PubMed1992

[Fetomaternal signal transduction by growth factors].

An attempt was made to review the current knowledge on the role of growth factors in the field of fetomaternal interaction. Of special interest was the relation between maternal T-lymphocytes and fetal growth. Stimulation of cytotrophoblast growth is effected by: IGF I/II (insulin-like growth factor), CSF-1 (colony stimulating factor), EGF (epidermal growth factor), FGF (fibroblast growth factor), IL-1, IL-3 (Interleukin), PDGF (platelet derived growth factor). TNF (tumor necrosis factor) inhibits trophoblast cell growth. TNF is synthesized in both decidual and chronic cells. CSF-1 considered the most potent stimulator of the induction of trophoblast cell growth. Cytotrophoblast itself produces IGF I/II, EGF, PDGF, TGF (transforming growth factor). Furthermore, it is known that HCG-secretion is mainly stimulated by IL-1. Whereas intra- and paracrine mechanisms in the placenta will remain in the field of basic research for the next future, animal experiments proving the positive impact of IL-3 and GM-CSF (granulocyte/macrophage-colony stimulating factor) on trophoblast growth should give reason for clinical investigations. It is assumed, that maternal T-lymphocytes realize paternally inherited alloantigenic structures resulting in local response of IL-3 and GM-CSF production.

Embryonic and Fetal Development↗
PubMed1992

Effect of AWD 52-39 on vasoconstriction induced by noradrenaline and 5-hydroxytryptamine in vitro and in vivo in rats.

The vascular effect of the potential nootropic AWD 52-39 (1; N,N-diacetoxyethyl-9,10-dihydrolysergic acid amide) as well as its influence on noradrenaline- or 5-HT-induced vasoconstriction were studied in the isolated rat aorta and in anesthetized normotensive and pithed rats. Vasoconstriction was determined by measuring the increase in mean arterial pressure (MAP). Both in vitro and in pithed rats, 1 caused a slight vasoconstriction, whereas a dose-dependent short-lasting decrease in mean arterial pressure was found in normotensive rats. In vitro and in pithed rats, 1 exerted no influence on the noradrenaline-induced vasoconstriction, while the 5-HT-induced contractile response was significantly inhibited. These findings characterize 1 as a competitive antagonist at vascular 5-HT2 receptors without any alpha-adrenolytic effect.

Animals↗
PubMed1991

[Principles of gene technology and potentials of DNA diagnosis].

Gene technology offers new potentialities for medicine in the diagnosis, treatment and also prevention of disease. DNA diagnostic procedures are already a cornerstone of genetic counselling. The number of mutated genes identified and, as a consequence, the number of disorders diagnosable with a molecular genetic approach, is steadily increasing. Since a given gene is present in practically all somatic cells, it can, irrespective of its expression, be analyzed using white blood cells or chorionic vili as a source of DNA. This results in an extension of disorders diagnosable before birth (prenatal diagnosis) or before its clinical manifestation (presymptomatic diagnosis) as well as in the reliable recognition of clinically healthy carriers of defective genes. DNA diagnostic procedures have already gained practical application in oncology, immunology or forensic medicine. The methodology of molecular biology allows the analysis of infectious agents in tissues or body fluids that are only present in a latent state. We are only at the dawn of the century of molecular medicine. However, our knowledge of the cause and the nature not only of rare single genetic diseases but also of common multifactorial disorders, such as cardiovascular diseases, cancer or autoimmune diseases, is increasing through gene technology. Therefore, on the one hand the new genetics holds out numerous promises and hopes, while on the other hand, a future characterized by exorbitant genetic testing increases an irrational fear of this technology in the public. Members of the medical profession must interest themselves in molecular genetics in order to be able to follow the development of modern medicine but also to inform their patients and the general public about the new possibilities and limitations, as well as any risks, of genetic testing. This is the only way to ensure proper use of gene technology in medicine without irrational legal restrictions imposed by an ill informed public.

DNA↗
PubMed1991

[Effect of viral structure and replication characteristics on the pathogenesis of infectious bursal disease].

Infectious bursal disease (IBD) is a highly contagious disease of young chickens, which occurs world-wide, and is responsible for severe losses in poultry industries. In birds surviving an acute infection, lymphoid cells in the bursa of Fabricius are destroyed, resulting in B-cell-dependent immunodeficiency. This causes increased susceptibility to diseases by otherwise harmless agents. The decisive role in the pathogenesis of IBD is played by the bursa, representing the target organ of the aetiological agent, infectious bursal disease virus (IBDV). By adaptation of IBDV to chicken embryo cells, we obtained several variants of a pathogenic wild type strain. These variants had altered abilities for replication in actively dividing B lymphocytes and, consequently, had altered pathogenic properties. An IBDV isolate from turkeys, non-pathogenic for chickens, was used to create reassortant virus strains. The virological and the biological characterization of these IBDV variants is reported.

Animals↗
PubMed1991

Endonuclease activity of Escherichia coli DNA helicase I directed against the transfer origin of the F factor.

DNA helicase I, the traI gene product of the Escherichia coli F factor, was shown to be associated with endonuclease activity specific for the transfer origin of the F plasmid, oriT. In the presence of Mg2+, the purified enzyme forms a complex, stable in the presence of sodium dodecylsulfate (SDS) with a negatively superhelical chimeric plasmid containing oriT. The enzyme nicks and, after this, apparently binds to the 5' nick terminus when this complex is heated in the presence of SDS and/or EDTA or treated with proteinase K. Dideoxy sequencing locates the nick site in the F DNA strand transferred during bacterial conjugation after nucleotide 138 clockwise of the mid-point of the BglII site at 66.7 kb of the F genetic map. A sequencing stop after nucleotide 137 of this strand (where oriT-nicking seems to occur in vivo) is possibly an artefact caused by helicase I protein attached to the 5' terminal nucleotide. Deletion in the amino-terminal part of the traI polypeptide abolishes the oriT-nicking activity while leaving the strand-separating activity intact. These results confirm the prediction from genetic studies that helicase I is bifunctional with site-specific endonuclease and strand-separating activities.

Base Sequence↗