TY - JOUR A1 - Stopper, Helga A1 - Metzler, M. T1 - Carcinogenic oestrogens induce respiration deficiency mutation in yeast N2 - In addition to hormonal activity, genetic darnage has been proposed as an important factor in oestrogen-mediated carcinogenesis. However, as short-term tests for oestrogens usually fail to show DNA mutations, lesions other than dassie nuclear DNA mutation have to be considered. Oestrogeninduced mitochondrial darnage was studied in the yeast Saccharomyces cerevisiae. Stilbene-type, but not steroidal, oestrogens were found to induce respiration-dcficient petite mutation. The effect was inversely correlated with cytotoxicity and required aromatic hydroxyl groups at the stilbene molecule. It only occurred under growth conditions and apparently was not due to the A TPase inhibitory qualities of stilbene oestrogens. Other studies have shown that petite mutation clones, which can be induced by a variety of substances, contain altered mitochondrial DNA. The mechanism of petite mutation induction might be important in tumorigenesis by also acting on nuclear DNA or facilitating carcinogenesis by disturbance of mitochondrial function. KW - Toxikologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63466 ER - TY - JOUR A1 - Carr, Martha A1 - Schneider, Wolfgang T1 - Long-term maintenance of organizational strategies in kindergarten children N2 - The goal of the present study was to determine whether 4- and 5-year-old kindergarten children could be trained to maintain an organizational strategy over 2- and 8 week periods through an elaborate training program. A second goal was to assess the effects of the training program on strategy awareness. Twenty-eight kindergarten children were pretested on two sort-recall tasks and their awareness of the use of the clustering strategy was assessed through a protocol type procedure. Half the children received seven half-hour sessions of individual training in the clustering strategy and half the children participated in a control group. Both groups were post-tested on two sort-recall tasks 2 weeks following training and again 8 weeks following training. Strategy awareness, as measured by verbal protocol, was assessed at both post-test points. The elaborate strategy training program was successful in inducing short- and long-term strategy maintenance of the clustering strategy. Trained children’s clustering during sorting and clustering during recall was consistently related to the amount of items correctly recalled. No differences in strategy awareness were found. These findings demonstrate that the elaborate training procedure used in this study can be a very effective memory technique for young kindergarten children. KW - Psychologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62157 ER - TY - JOUR A1 - Tas, P. A1 - Stopper, Helga A1 - Koschel, K. A1 - Schiffmann, D. T1 - Influence of the carcinogenic oestrogen diethylstilboestrol on the intracellular calcium level in C6 rat glioma cells N2 - The ~fthetic oes~rog~n diethylsti~boestrol (DES) causes a dose-dependent elevation of the cytoplasuuc Ca concentratton m C6 rat ghoma cells. This Ca2+ rise is caused neither by Ca2+ influx nor ~-r release from the ~a2 + stores of the endoplasmic reticulum. Therefore it seems likely that DES mob!hzes Ca2+ from a nutochondrial source. The DES-induced Ca2+ signal is remarkably similar to the one mduced by the. tumou~ promotor ~hapsigargin. As this compound causes leakage of calcium from the endoplasmt~ rettculum tt ~ms posstble that DES induces a similar leakage from mitochondrial Ca2+ stores. It remaans to be estabhshed whether the DES-mediated rise in intracellular calcium is causally related to the tumour-promoting properties of this compound KW - Toxikologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63459 ER - TY - JOUR A1 - Hacker, Jörg A1 - Rdest, Ursula A1 - Wintermeyer, E. A1 - Ludwig, B. T1 - Legiolysin, a New Hemolysin from L. pneumophila N2 - Legionella pneumophila generares exotoxins, cytolysins, proteases oc hemolysins that darnage host cells llke erythrocytes or rissue cu lrure cells. The gene for a new L. pneumophila hemolysin withour a proteolytic activiry was idemified, cloned in E. coli and sequenced. The gene producr was analysed by SDS-Polyacrylamide-gel-electrophoresis. N2 - Legionella pneum.ophila bildet Exoroxine, Zytolysine, Proteasen oder Hämolysine, die Wirtszellen wie Erythrozyten oder Animalzellen schädigen. Das Gen für ein neues L. pneumophila Hämolysin ohne proteolytische Aktivität wurde identifiziert, in E. coli kloniert und sequenziert. Das Genprodukt wurde durch SDS-Gelelcktropborese analysiert. KW - Hämolysin KW - Legionella pneumophila Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73070 ER - TY - JOUR A1 - Lutz, Werner K. A1 - Poetzsch, J. A1 - Schlatter, J. A1 - Schlatter, C. T1 - The real role of risk assessment in cancer risk management N2 - Rtgulatory aclio11s Iaken to reduu tht risk of harmfultffects of exposure to chemieals ofltn arenot commensurDtt with the toxicologicDf risk SJsstS&ment. A numbtr of factors relating to psychology, sociology, economics Dntl politics rather than science and medicine afftct tht final decision. Wemer Lutz and colleagues illustratt the situation using tht feuktmia-indudng chtmiCJJI benzene as an examplt. KW - Toxikologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60730 ER - TY - JOUR A1 - Krzymanski, Maciej A1 - Waaga, Ana M. A1 - Ulrichs, Karin A1 - Deja, Aadam A1 - Oko, Andrzej A1 - Rommel, Thomas A1 - Müller-Ruchholtz, Wolfgang T1 - The influence of MHC class II antigen blockade by perfusion with a monoclonal antibody on rat renal graft survival N2 - To decrease immunogenicity of the rat kidney, grafts were perfused with an anti-MHC class li monoclonal antibody (mAb ). How effectively this procedure blocked dass li-positive cells, which were mainly dendritic in appearance, was checked by immunostaining renal sections after perfusion and comparing them with in vitro stained sections. Optimum conditions were applied for graft pretreatment before transplantation. This procedure prolonged graft survival, though not satisfactorily from the biological point ofview (9.6 ± 0.8 versus 7.7 ± 0.5 days in the control group; P < 0.02). The dendritic cells were not killed but blocked. Several hours after transplantation, the mAb dissociated from these dass li-positive cells. It was also shown that donor cells migrate into the recipient's spieen early after transplantation. The number of these cells was smaller when the transplanted organ was perfused with the mAb. Further studies are suggested to deplete the graft of donor dendritic cells more adequately. They should also combine graft perfusion with antidass II mAb and recipient immunosuppression at reduced doses. KW - Chirurgie KW - Class II antigen blockade KW - rat KW - renal transplantation KW - Monoclonal antibody KW - dass II antigen blockade Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64431 ER - TY - JOUR A1 - Schneider-Schaulies, Sibylle A1 - Kreth, H. W. A1 - Hofmann, G. A1 - Billeter, M. A. A1 - ter Meulen, V. T1 - Expression of measles virus RNA in peripheral blood mononuclear cells of patients with measles, SSPE, and autoimmune diseases N2 - No abstract available KW - Virologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62297 ER - TY - JOUR A1 - Kraus, E. A1 - Schneider-Schaulies, Sibylle A1 - Miyasaka, M. A1 - Tamatani, T. A1 - Sedgwick, J. T1 - Augmentation of major histocompatibility complex class I and ICAM-1 expression on glial cells following measles virus infection: evidence for the role of type-1 interferon N2 - No abstract available KW - Virologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62301 ER - TY - JOUR A1 - Feuerstein, G. A1 - Zerbe, R. L. A1 - Sirén, Anna-Leena T1 - Supraoptic nuclei in vasopressin and hemodynamic responses to hemorrhage in rats N2 - CARDIOVASCULAR and vasopressin (A VP) responses to hcmorrhagc wcrc studicd in rats with lesions of the hypothalamic supraoptic nuclei (SONL). Bleeding caused hypotension and increase in heart rate (HR) and A VP. SONL rats failed to fully recover from bleeding as compared to normal rats. Plasma A VP in SONL rats was in the normal in basal conditions, but failed to increase to levels attained in normal rats throughout the post-hemorrhage period. These data suggcst that the supraoptic nuclei are the primary regulatory sitcs for A VP release in rcsponse to hemorrhage and that lack of adequate A VP release significantly retards blood pressure recovery after bleeding. KW - Neurobiologie KW - Hypothalamus KW - Supraoptic nucleus KW - Hemorrhage KW - Vasopressin Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63057 ER - TY - JOUR A1 - Sirén, Anna-Leena A1 - Feuerstein, G. T1 - Hypothalamic opioid µ-receptors regulate discrete hemodynamic functions in the conscious rat N2 - The effect of the selective \(\mu\)-opioid agonist o-Ala\(^2\)-Me-Phe\(^4\)-Gly-ol'-enkephalin (DAGO), injected into the medial preoptic nucleus of hypothalamus, on cardiac output and regional blood flow was studied in the conscious rat and the effect of DAGO on renal sympathetic nerve activity and renal blood flow was studied in anesthetized rats. In conscious rats, injections of DAGO (1 or 10 nmol) into the preoptic nucleus increased the blood pressure in a dose-related manner. The maximum rises of mean arterial pressure and pulse pressure after the larger dose were +23 ± 5 mmHg (mean ±SEM, P < 0.01) and + 17 ± 3 mmHg(P < 0.01), respectively. A small dose (0.1 nmol) increased heart rate ( +47 ± 13 bpm, P < 0.05); thc 1 nmol dosc produced bradycardia (- 39 ± 11 bpm, P < 0.05), while the 10 nmol dose initially decreased heart rate ( -68 ± 15 bpm (P < 0.01) and then gradually increased heart rate to a maximum of + 74 ± 13 bpm, (P < 0.0 1). A long-lasting increase in cardiac output was also elicited by DAGO, with maximum changes after 1 and 10 nmol of + 14 ± 6% and +22 ± 7% (P < 0.01), respectively. B1ood flow in the hindquarters increascd after DAGO but the mesenteric and renal blood ftow decreased in a dose-related manner. Significant responscs in hindquarter and mesenteric blood fl.ow after DAGO were independent of systemic hemodynamic responses at the dose ofO.l nmol. The vascular resistance in the hindquarters significantly decreased after a small dose of DAGO while the larger doses dose-dependently increased mesenteric and renal vascular resistance. A crucial role of the sympathetic nervous system in the hemodynamic effects of DAGO was demonstrated: (1) by the profound activation of renal sympathetic nerve activity after injections of DAGO (I nmol/100 nl) into the preoptic nucleus, (2) by blockade of the pressor, tachycardic and regional hemodynamic effects of DAGO (I nmol) by the ganglion blocker ch1orisondamine (5 mg/kg i.v.). The results suggest that the pressor effect of DAGO in preoptic nucleus is due primarily to an increase in cardiac output. The differential changes in blood ftow in organs further suggest that the opioid \(\mu\)-receptors in the preoptic nucleus might be involved in the integration of peripheral blood ftow in the hypothalamus during affective behavior. KW - Neurobiologie KW - chlorisondamine KW - blood pressure KW - heart rate KW - cardiac output KW - regional blood ftow KW - sympathetic nerve activity. Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63069 ER - TY - JOUR A1 - Vonhof, S. A1 - Sirén, Anna-Leena A1 - Feuerstein, G. T1 - Central ventilatory effects of thyrotropin-releasing hormone in the conscious rat N2 - Thyrotropin-releasing hormonewas shown to exert potent ventilatory effects after centrat administration. These data, however, were derived from studies using anesthetized animal preparations. Since TRH elicits strong arousal reactions, the observed ventilatory effects of TRH under anesthesia may have been due to nonspecific reduction in the anesthetic state of the animals. In order to clarify the extent to which the reversal of anesthesia may change ventilatory parameters after TRH application, we investigated the effect of TRH on Ventilation rate, relative tidal volume, relative respiratory minute volume, CO\(_2\) production CO\(_2\) consumption, and locomotor activity in the conscious, unrestrained rat. Intracerebroventricular application of TRH induced a dose-dependent, sustained increase in ventilation rate, relative tidal volume, and relative respiratory minute volume of maximally 128%, 890%, and 235%, respectively. In addition, CO\(_2\) production and O\(_2\) consumption were elevated by 4.6 and 11.7 fold, whiJe no significant changes in locomotor activity were observed. The results suggest that TRH stimulates ventilation by a mechanism independent of its analeptic properties. KW - Neurobiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63075 ER - TY - JOUR A1 - Adeyemo, O. M. A1 - Shapira, S. A1 - Tombaccini, D. A1 - Pollard, H. A1 - Feuerstein, G. A1 - Sirén, Anna-Leena T1 - A goldfish model for evaluation of the neurotoxicit of \(\omega\)-conotoxin GVIA and screening of monoclonal antibodies N2 - A Goldfish Model for Evaluation of the Neurotaxicity of \(\omega\)-Conotoxin GVI A and Screening of Monoclonal Antibodies. ADEYEMO, 0. M .. SHAPIRA, S., TOMBACCINI, D., POLLARD, H. 8 .• FEUERSTEIN, G .. AND SIREN, A-L. ( 1991 ). Toxicol. App/. Pharmaco/. 108, 489-496. The neurotoxicity of \(\omega\)-conotoxin (\(\omega\)-CgTx), a potent neuronal voltage-sensitive calcium channel blocker, was measured using a new bioassay. \(\omega\)-CgTx was administered intraperitoneally (ip) to goldfish weighing approximately 1.6 g, and dose-related changes were observed over a 2-hr period. \(\omega\)CgTx induced time- and dose-dependent abnormal swimming behavior (ASB) and mortality. The antitoxin activity of the antiborlies was investigated in vivo by either ( l) preincubation of the antibody with w-CgTx at 4°C overnight, or (2) pretreatment with antibody, 30 min before \(\omega\)CgTx injection in a 10:1 antibody/\(\omega\)-CgTx molar ratio. The LD50 dose of \(\omega\)-CgTx in goldfish was 5 nmol/kg ip, and preincubation of monoclonal antibody (50 nmol/kg ip) with \(\omega\)-CgTx (5 nmol/kg ip) significantly (p < 0.05) reduced mortality. ASB, and toxicity time. The antitoxin activity of the monoclonal antiborlies evidenced in the goldfish bioassay was further tested in the conscious rat. In the rat, the increases in mean arterial pressure and heart rate induced by \(\omega\)-CgTx (0.03 nmol/rat icv) were significantly (p < 0.02 and p < 0.0 l, respectively) attenuated by preincubation of the toxin with the antibody (0.3 nmol/rat). We conclude that the goldfish bioassay provides a simple. accurate, and inexpensive in vivo model for the study of the toxicity of \(\omega\)CgTx KW - Neurobiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63087 ER - TY - JOUR A1 - Sirén, Anna-Leena A1 - Vonhof, S. A1 - Feuerstein, G. T1 - Hemodynamic defense response to thyrotropin-releasing hormone injected into medial preoptic nucleus in rats N2 - No abstract available KW - Neurobiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63099 ER - TY - JOUR A1 - Rethwilm, Axel A1 - Erlwein, Otto A1 - Baunach, Gerald A1 - Mauerer, Bernd A1 - ter Meulen, Volker T1 - The transcriptional transactivator of human foamy virus maps to the bel 1 genomic region N2 - The human foamy virus (HFV) genome possesses three open reading frames (bel I, 2, and 3) located between env and the 3' long terminal repeat. By analogy to other human retroviruses this region was selected as the most Iikely candidate to encode the viral transactivator. ResuIts presented here confirmed this and showed further that a deletion introduced only into the bell open reading frame of a plasmid derived from an infectious molecular clone of HFV abolished transactivation. In contrast, deletions in bel 2 and bel 3 had only minor effects on the ability to transactivate. The role of the bel I genomic region as a transactivator was further investigated by eukaryotic expression of a genome fragment of HFV spanning the bel I open reading frame. A construct expressing bell under control of a heterologous promoter was found to transactivate the HFV long terminal repeat in a dose-dependent fashion. Furthermore, it is shown that the U3 region of the HFV long terminal repeat is sufficient to respond to the HFV transactivator. KW - Virologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47342 ER - TY - JOUR A1 - Schneider-Schaulies, Jürgen A1 - Kirchhoff, F. A1 - Archelos, J. A1 - Schachner, M. T1 - Downregulation of Myelin Associated Glycoprotein (MAG) on Schwann cells by interferon-gamma and tumor necrosis factor-alpha affects neurite outgrowth N2 - To investigate the influence of inflammatory cytokines on the potential of peripheral nerves to regenerate, we analyzed the effect of interferon-y (lFN-y) and tumor necrosis factor-a (TNF-a) on the ability of immortalized Schwann cells to mediate outgrowth of neurites from primary DRG neurons. We found that IFN-y and TNF-a synergistically inhibited the neurite outgrowth-promoting properties of the Schwann cells by spedfically dowllregulating myelin-associated glycoprotein (MAG) at the levels of mRNA and cell surface protein by approximately 60%. Antibodies to MAG inhibited the outgrowth of neurites on Schwann cells to the same extent as treatment with the two cytokines. Since MAG appears to be involved in both neurite outgrowth and myelination, our findings may provide evidence for a mechanism, by wh ich inflammatory cytokines interfere with Schwann cell-neuron interactions. KW - Immunologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54850 ER - TY - JOUR A1 - Vonhof, S. A1 - Sirén, Anna-Leena T1 - Reversal of µ-opioid-mediated respiratory depression by α2-adrenoceptor antagonism N2 - The present study was performed in order to evaluate the effects of the selective 02- adrenoceptor antagonist 6-chloro-2,3,4,5-tetrahydro-3-methyl-1H-3-benzazepine (SK&F 86466) on dermorphin-induced analgesia, respiratory depression and inhibition of locomotor activity in the conscious rat. Intracerebroventricular (icv) administration of dermorphin (3 nmol/rat) decreased respiration rate and relative ventilatory minute volume maximally by 38 % and 50 % of baseline respectively. SK&F 86466 dose-dependently reversed the dermorphin-induced depression of ventilatory parameters, while SK&F 86466 exerted no effect on dermorphin-induced analgesia or depression of locomotor activity due to catalepsia. It appears, therefore, that a 2-adrenoceptors selectively interact with Jl2-opioid-receptor mediated effects, such as respiratory depression, but are not involved in the modulation of Jl,-opioid-related effects, such as supraspinal analgesia and depression of locomotor activity. KW - Biowissenschaften Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47454 ER - TY - JOUR A1 - Solbach, Werner A1 - Moll, Heidrun A1 - Röllinghoff, Martin T1 - Lymphocytes play the music but the macrophage calls the tune N2 - No abstract available KW - Immunologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45889 ER - TY - JOUR A1 - Pfeffer, K. A1 - Schoel, H. A1 - Gulle, H. A1 - Moll, Heidrun A1 - Kromer, S. A1 - Kaufmann, S. H. E. A1 - Wagner, H. T1 - Analysis of primary T cell responses to intact and fractionated microbial pathogens N2 - Freshly isolated human T lymphocytes were tested for their response to mycobacteria, mycobacteriallysates, 2 dimensional (2D) PAGE separated mycobacteriallysates, leishmania and defined leishmanial antigen preparations. While,o T cells proliferated vigourously in the presence of mycobacteria and mycobacteria derived lysates, a significant stimulation from 2 D gel separated lysates was not detected. In addition '10 T cells failed to respond towards leishmania or leishmanial components. In the ab T cell compartment some donors, presumably according to their state of immunity against mycobacteria, responded to mycobacteria, mycobacterial lysates and 2 D gel separated mycobacterial lysates. Neither freshly isolated '10 T cells nor ab T cells from naive donors did mount a significant immune response against leishmania. Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46916 ER - TY - CHAP A1 - Eckstein, V. A1 - Ulrichs, Karin A1 - Meincke, G. A1 - Mülller-Ruchholtz, W. T1 - Transplantation of Diabetic Patients With Xenogeneic Pancreatic Islets Has to Consider Natural Xenophile Antibodies (NXA) In Patients Sera As a Major Obstacle to Success N2 - No abstract available KW - Immunbiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45707 ER - TY - CHAP A1 - Winoto-Morbach, S. A1 - Ulrichs, Karin A1 - Müller-Ruchholtz, W. T1 - New Developments in Biodegradable Microspheres For Magnetic Separation Techniques N2 - No abstract available KW - Immunbiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45712 ER -