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Biomedical subjects

U Wagner

Publications and source records attributed to U Wagner.

At least 181 records · Page 10Linked to original sources
PubMed1991

An approach to fetal surgery: endoscopic use of excimer laser.

Recent progress in the area of prenatal diagnosis by means of ultrasound forces the improvement of surgical techniques for intra-uterine fetal therapy. By the use of short, intense pulses of ultraviolet laser light (20-200 ns long) a photoablation of defined samples of biological tissue is performed with no substantial thermal side effects. The experimental set-up applied in this study included endoscopic operation on five fetal lambs. Macroscopically, a sharp edge in the incision area was observed at both prechosen laser frequencies of 10 and 40 Hz. The clinical application of pulsed ultraviolet laser systems with the characteristics of guided photoablation and atraumatic incisions avoiding thermal side-effects opens new perspectives for fetal surgery.

Animals↗
PubMed1991

[The OFFER self concept questionnaire for adolescents and the success of inpatient psychotherapy].

The OFFER-Self-Image-Questionnaire reflect psychotherapeutic effects under special conditions. The OFFER-Self-Image-Questionnaire was used to evaluate outcome of in-patient psychotherapy in 15 adolescents. An increase of 8 or more points on the standard scale between the first and fourth week was associated with favourable outcome while an increase of 7 or less points indicated less favourable outcome.

Adolescent↗
PubMed1990

BAP, a rat liver protein that activates transcription through a promoter element with similarity to the USF/MLTF binding site.

The vitellogenin genes of Xenopus are liver-specifically expressed. An in vitro transcription system derived from rat liver nuclei allowed us to define the cis-element BABS (B-activator binding site) in the promoter of the B1 vitellogenin gene. An oligonucleotide encompassing the region from -53 to -44 linked to a TATA box is sufficient for a tenfold increase of the transcriptional activity. Gel retardation assays with nuclear rat liver proteins reveal two DNA-protein complexes: Complex 1 can be competed by the USF/MLTF binding site of the adeno major late promoter whereas complex 2 is a distinct protein we refer to as BAP (B-activator protein). In vitro transcription experiments in the presence of USF/MLTF binding site as competitor show that BAP is an efficient transcription factor. Based on UV cross-linking we estimate that BAP has a molecular weight of 58 kd. Phosphatase treatment reveals that DNA binding of BAP requires phosphorylation. BABS is also present in the hepatitis B virus enhancer suggesting that it might play a role in the tumorigenic potential of the virus.

Animals↗
PubMed1990

[Health behavior and cardiovascular risk factors in females in relation to their marital status].

This is an overview of the literature analysing the international level of knowledge about the influence of marital status on the prevalence of cigarette smoking, hypertension, hyperlipoproteinemia, obesity, alcohol consumption and type-A-behavior of women. An accumulation of the more behavior-dependent risk factors cigarette smoking and alcohol consumption was found by divorced and of the obesity by never married women. Widowed women scarcely differ from women in other marital status groups in their risk factor profile. The risk factors hypertension and hyperlipoproteinemia hardly correlate with the marital status. The overcome-behavior by loading is discussed as one possible cause of the found correlations. That's why family and social support has got a preventive consequence.

Adult↗
PubMed1990

Measuring threshold of reinforcing brain stimulation by the method of constant stimuli.

A new method for measuring threshold of reinforcing electrical brain stimulation is described and results of a parametric study using this method are presented. Two groups of rats were trained under a concurrent FR-CRF (fixed ratio-continuous reinforcement) schedule of reinforcement provided by electrical stimulation of the lateral hypothalamus. The invariant intermittent FR schedule of reinforcement was used to maintain a baseline of behavior while a superimposed concurrent CRF schedule was used to measure reinforcement magnitude by varying the intensity of the CRF stimulus between zero and a maximum. Increasing and decreasing stimulus intensity on the CRF schedule leads to a gradual disappearance, respectively reappearance, of post-reinforcement pauses (PRPs) on the concurrent FR schedule, providing a criterion for changeover in schedule control, and thus, for threshold of reinforcement. To illustrate the measurement of threshold according to psychophysical requirements of the Method of Constant Stimuli, different CRF intensities were given in a randomized order. In one group of animals FR and CRF stimuli were given through the same electrode. Another group received FR and CRF stimuli through separate electrodes implanted in different hemispheres of the brain. For both groups the duration of the PRP was used as the dependent variable. The data of both groups showed a high negative correlation between the intensity of the CRF stimulus and the duration of the PRP, which is consistent with the results of experiments in which a Method of Limits procedure was used. On the basis of this relationship between CRF current intensity and PRP duration a threshold for reinforcing brain stimulation was calculated.

Animals↗
PubMed1990

[A trial with immunotherapy of ovarian cancer by idiotype vaccination. Activation of the idiotype network in patients with advanced ovarian cancers by treatment with monoclonal antibody OC125].

Up to date, the positive effect of immunotherapy, using tumour-associated antigens or tumour cells of ovarian carcinomas, is still vague. Another and effective approach to overcome an experimentally induced tolerance, is the presentation of an definitive antigen in a different surrounding by the induction of the idiotypic network. Antibodies against a tumour-associated antigen are used to induce following antibodies, which are directed against the variable antigen-binding group, the so-called idiotype of the antibody-vaccine. Then, the induced antibodies carry a mirror image of the tumour-associated antigen and are therefore able to modulate the host's immune response against the tumour. For the induction of this system, we used the monoclonal antibody OC125 as a F(ab)2-fragment, which is directed against the tumour-associated antigen CA125 of epithelial ovarian carcinomas. 12 patients with advanced ovarian carcinomas received antibody fragments of the OC125 in the course of radioimmunodetections since 1985. Until April 1990 only these 5 patients, who developed the anti-idiotypic antibodies after the vaccination, are still alive. Our first results with the induction of the idiotypic network system for patients with advanced ovarian carcinomas indicate, that in spite of the same surgical and chemotherapeutical treatment, patients show a delayed clinical course after the induction of the idiotypic system. The transfer of the definitive tumour-associated antigen in an idiotypic antigen, seems to modulate the immunoresponse of the patients and in this way also the clinical course of a malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Anti-Idiotypic↗
PubMed1990

Immunogold labelling of membrane receptors for scanning electron microscopical investigations of genetically determined disorders of lipid metabolism.

Receptors binding of low-density lipoprotein at surfaces of human lymphocytes was studied by immunochemical and scanning electron microscopical methods. Using colloidal gold sol binding ability of cells from several probands could be demonstrated by immunolabelling. We investigated cell material from normolipidaemic persons and from patients with heterozygote autosomal monogenic hypercholesterolaemia. We found a distinct decrease of labelled gold particles at the cell surface of patients with this disorder of lipid metabolism. The simple extraction possibility of lymphocytes from human venous blood and the demonstrated scanning electron microscopical results recommend the described procedure for genetic application.

Apolipoproteins↗
PubMed1990

Accumulation of pollutants in the genital tract of sterility patients.

In order to assess the burden of environmental pollutants in the genital tract, 12 different chlorinated hydrocarbons were determined in 152 samples of follicular, seminal and cervical fluids from sterility patients in the in vitro fertilization programme at the Centre for Obstetrics and Gynaecology of the University of Bonn. The lowest concentrations were found in the follicular fluids of patients who eventually became pregnant by in vitro fertilization. Higher concentrations were found in patients with sterility of unknown origin. Concentrations in the cervical secretion were up to twenty times higher than those in the seminal or follicular fluids. The results show that considerable concentrations of chlorinated hydrocarbons may be present in parts of the reproductive system, and that these compounds accumulate in the reception zone for spermatozoa. Certain pollutants therefore probably contribute to infertility.

Cervix Uteri↗
PubMed1990

Evidence for interaction of human anti-idiotypic antibodies with CA 125 determination in a patient after radioimmunodetection.

Very high concentrations of CA 125 have been found in some ovarian cancer patients after repeated radioimmunodetection with anti-CA 125 antibodies [OC125-F(ab')2]. In one patient we measured a CA 125 concentration of 135,000 kilo-arb. units/L, using an enzyme immunoassay involving OC125 antibodies. With an immunoradiometric assay involving use of two new anti-CA 125 antibodies (B43.13 and B27.1), the CA 125 concentration was 34 kilo-arb. units/L, indicating a discrepancy. The component responsible for the high result in the enzyme immunoassay could be purified by immunoaffinity chromatography on Protein A-Sepharose. Furthermore this component bound to anti-human IgG-Sepharose in the same manner as did the serum IgG fraction. Adsorption of human anti-mouse antibodies present in the serum did not decrease the CA-125-like material. Binding of whole OC125 antibodies to the purified CA-125-like material was inhibited completely in the presence of CA 125 antigen. We infer that the false-positive CA 125 activity is ascribable to a human IgG directed against an idiotope of the OC125 antibody, which was induced by repeated application of OC125 antibodies. To avoid falsely positive results in patients receiving OC125 antibodies, CA 125 should be measured by an assay in which other antibodies are used.

Aged↗
PubMed1990

[A case report of welder's lung].

The case of a 57-year-old man is reported, who worked as a plasma welder about 15 years. Chronic recurrent bronchitis was diagnosed 12 years after beginning of this work. The patient changed the place of his employment but the course of disease was uncommonly progressive. He died of right ventricular heart failure 10 years later. One year before death, the chronic obstructive pulmonary lesions were acknowledged as occupational disease. The post-mortem histological and chemical analysis of lung tissue yielded a mixed dust pneumoconiosis. These findings supported additionally the diagnosis of occupational disease.

Dust↗
PubMed1990

[The pre- and postnatal carcinogenic effect of 3,3-diethyl-1-methyl-1-nitrosourea (DEMNU) in rats following intravenous application].

The pre- and postnatal administration of DEMNU induces a high frequency of tumors when applied via the intravenous route, and the latency periods show a dose dependence (table I). Tumors of the brain, spinal cord and cranial nerves clearly predominate. Furthermore, a large number of neoplasms of kidney, heart and soft tissue was observed (table II). As DEMNU is per se a very stable compound, it is suggested that this agent is metabolized by monooxygenases. 3-Ethyl-1-methyl-1-nitrosourea should be formed as an intermediate product via this pathway, which is relatively stable and might explain the mainly neurotropic carcinogenicity of DEMNU. Species differences in the carcinogenicity of trialkyl-nitrosoureas and the mode of metabolic activation are discussed.

Animals↗
PubMed1989

[Family status and coronary heart disease in the female].

This is an overview of the literature analysing the international level of knowledge about the influence of marital status on the coronary heart disease of women. Divorced and widowed women show a greater coronary risk than never married and married women, as some studies show. But there are also studies, which found no correlation between marital status and morbidity and mortality of coronary heart disease. In the multifactorical genesis of the coronary heart disease of women the marital status does not play the role of a definitive risk factor, but affects above all as a confounder of many psychosocial and coronary risk factors and there by influences the coronary risk of women.

Coronary Disease↗
PubMed1989

Interhemispheric relationship between lateral hypothalamic self-stimulation and the region of the nucleus tegmenti pedunculo-pontinus.

Electrical self-stimulation in the lateral hypothalamus was recorded in both hemispheres of 20 rats before and after making a lesion either by unilateral radiofrequency stimulation or by injection of N-methyl-D,L-aspartate into the region of the peduncular-pontine nucleus. For the animals which received the radiofrequency lesion, a rate-intensity function was established for 3 stimulation intensities 3 days before and 5 days after the lesion. For the animals in which N-methyl-D,L-aspartate was injected, a reinforcement threshold was measured 3 days before and after the lesion using a psychophysical method-of-limits procedure. With the rate-intensity procedure a decrease in the rate of self-stimulation was observed at the highest stimulation intensity through the electrode situated contralateral to the side of the lesion. Similarly, with the reinforcement threshold method, a significant increase in threshold was found from the electrode placed in the hemisphere contralateral but not ipsilateral to the site of the lesion. These data suggest an involvement of primarily crossed pathways coursing to or from the peduncular-pontine nucleus as being involved in the control of lateral hypothalamic self-stimulation.

Animals↗
PubMed1989

Liver cell specific gene transcription in vitro: the promoter elements HP1 and TATA box are necessary and sufficient to generate a liver-specific promoter.

The hepatocyte-specific promoter element HP1, which is present in several genes specifically expressed in the liver, is active in an in vitro transcription system. The liver-specificity is retained in the in vitro system, as the activity is found in extracts of rat liver or hepatoma cells but is absent in an L-cell extract. Mutational analysis identifies HP1 as a 13 bp element: Two point mutations abolish the function of HP1. This inactivation is correlated with a reduced binding affinity of the transcription factors recognizing HP1. Two other mutants, which reduce the activity of HP1, bind the transcription factors with an affinity identical to the wildtype sequence. This suggests that the binding of the transcription factors is not sufficient for activation of HP1 dependent transcription. The function of HP1 depends on the presence of a TATA box within a distance of some 70 bp. Various TATA sequences are functional and no stereospecific alignment between HP1 and the TATA box is required.

Animals↗
PubMed1989

Self-, ingroup, and outgroup achievement attributions of German and Turkish pupils.

The present study investigated intergroup bias in achievement attributions in a sample of 62 German and 55 Turkish pupils (aged 15 years) in the Federal Republic of Germany. The design was 2 x 2 x 2 x 3 (Ethnic Group x Outgroup Prejudice x Outcome x Stimulus) with repeated measures on the last two factors. Subjects attributed examination performance to ability, effort, luck, and task difficulty. Intergroup bias was limited to German pupils, who attributed failure of an ingroup member or self more to bad luck than they did that of an outgroup member. Turkish pupils acted more in terms of self than ingroup, attributing the success of another Turkish child more to good luck than they did that of self or an outgroup member. They also failed to distinguish clearly between success and failure in their task attributions. Results are discussed in terms of the inventive nature of explanations for ability-linked performance and the motivational consequences of causal attributions.

Achievement↗