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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 74-78 
    ISSN: 1432-2072
    Keywords: Piracetam ; Choline ; m-Cholinoceptor density ; Frontal cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Chronic treatment (2 weeks) with piracetam (500 mg/kg, once daily PO) elevatedm-cholinoceptor density in the frontal cortex of aged (18 months) female mice by about 30–40%, but had no effect onm-cholinoceptor density in the frontal cortex of young (4 weeks) mice. The effect of piracetam onm-cholinoceptor density as determined by the specific binding of tritiated QNB was not affected by concomitant daily treatment with either choline (200 mg/kg) or scopolamine (4 mg/kg). It is concluded that the effect of piracetam onm-cholinoceptor density could explain the positive effects which have been reported for combinations of cholinergic precursor treatment with piracetam on memory and other cognitive functions in aged experimental animals and patients and could also represent part of the possible mechanism of action of piracetam alone.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Radiation and environmental biophysics 25 (1986), S. 195-199 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Two-cell mouse embryos were X-irradiated (2 Gy) in vitro. Comparison of the frequency of micronuclei in the early interphase of the four-cell stage with that in the late interphase revealed a small, but significant loss of micronuclei during interphase: 27.9 versus 23.4 micronuclei per 100 cells.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Radiation and environmental biophysics 25 (1986), S. 213-217 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Two-cell mouse embryos were X-irradiated (1 Gy) and immediately thereafter exposed to mercuric chloride (3 µM) up to the blastocyst stage. When combined treatment started shortly (about 1 to 2 h) before mitosis to the four-cell stage, blastocyst formation, hatching of blastocysts, trophoblast outgrowth and ICM formation were impaired stronger than expected from the addition of the single effects. The enhancement of risk was maximal for hatching of blastocysts and no further increase was observed for trophoblast outgrowth and ICM formation. When exposure of embryos to X-rays and mercury began about 5 to 6 h before mitosis to the four-cell stage, only additive effects were obtained for the endpoints mentioned above.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Radiation and environmental biophysics 27 (1988), S. 115-121 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary There are situations in which the exposure to more than one agent results in an enhanced risk for the exposed organism, that is in which the observed effect exceeds the effect expected from the addition of the individual effects. Our knowledge of such hazards is rather limited, in particular for those agents that occur in the environment of man. When early mouse embryos in vitro were exposed to ionizing radiation and mercuric chloride, the observed risk was higher than expected from the individual effects. This increase in risk was due to an interaction between mechanisms induced by ionizing radiation and mercury. To gain some more insight into the mode of interaction, the time requirements of mercury exposure were studied. The amount of interaction did not depend on mercury exposure before or during irradiation. However, to achieve an enhanced risk, exposure had to start as soon as possible after irradiation and had to last as long as possible. This time dependence suggests that if inhibition of DNA-repair is involved in the mechanism of interaction at all, then there must be an additional late process that is also impaired by mercury.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Radiation and environmental biophysics 24 (1985), S. 17-25 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Sensitive cocultivation techniques were applied to study the radiation-induced activation of endogenous retroviral genomes in different mouse strains by the alpha-emitting radionuclide224Radium. Activated infectious C-type retroviruses were detected in spleen, bone marrow and bone tissues of C57BL/6-, BALB/c- and NMRI mice. The titres of high-dose-irradiated animals were higher than those found in low-dose-irradiated animals. Infectious retrovirus could be detected with a dose of 13.2 rad (maximum dose rate 0.9 rad/day) in the skeleton, and a dose of 4.2 rad (maximum dose rate 0.3 rad/day) in the spleen. The virus activation pattern was different in the three mouse strains. These data indicate that activation of endogenous retroviral genomes by alpha-irradiation shows a dose-effect relationship and a dependence on the genetic background of the mouse.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 414 (1989), S. 139-144 
    ISSN: 1432-2013
    Keywords: GABAB-receptor ; Baclofen ; Inhibition ; GABAA-receptor ; Inhibitory neurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Intracellular recordings were made from electrophysiologically identified inhibitory neurons in the dentate hilus. (−)Baclofen (0.1–0.5 μmol/l), applied by the bath, strongly hyperpolarized inhibitory neurons, reduced their input resistance and induced outward currents under voltage clamp at holding potential of −60 mV in cells recorded with KCl-filled electrodes. Increasing the (−)baclofen concentration (up to 1 μmol/l) did not increase the amplitude of the outward current, but increased its duration. (−)Baclofen depressed Cl-dependent IPSPs evoked by perforant path stimulation in inhibitory neurones, granule cells and CA3 neurons. In the case of inhibitory neurons and CA3 neurons, depression of IPSPs, membrane hyperpolarization and increase in membrane conductance concurred. All effects were blocked by BaCl2 (1 mmol/l) in the superfusate. In the case of granule cells, depression of IPSPs by (−)balcofen out-lasted an only small membrane hyperpolarization, conductance increase or outward current. High concentrations (up to 10 μmol/l) of (−)baclofen depressed evoked IPSPs of granule cells for an extended period of time, but the other effects remained small and transient. IPSPs elicited in granule cells by microdrop application of glutamate to the dentate hilus were also blocked by (−)baclofen, but spontaneous IPSPs were only reduced in amplitude. We suggest that the blockade of GABAA receptor-mediated IPSPs of hippocampal neurons by the GABAB receptor agonist (−)baclofen can be explained by a K-dependent hyperpolarization of inhibitory neurons.
    Type of Medium: Electronic Resource
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  • 17
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les métastases hépatiques des cancers colo-rectaux trouvent leur origine dans les cellules malignes qui pénètrent dans la circulation portale. Quatre cent soixante malades provenant de 7 institutions ont constitué la base d'un essai prospectif randomisé destiné à évaluer la valeur d'une perfusion portale à l'aide d'un agent chimique dont le but est de prévenir les métastases après chirurgie curative du cancer colo-rectal. En préopératoire, les malades ont été choisis au hasard pour constituer 2 groupes: (a) malades traités par la chirurgie (groupe de contrôle), (b) opérés recevant une perfusion portale de 5-FU (500 mg/m2/jour × 7) infusée continuement les 7 premiers jours post-opératoires et de mitomycine C (10 mg/m2/24 heures après l'intervention) pendant 2 heures. Le cathéter veineux portal fut placé dans une collatérale quelconque du système veineux mésentérique au cours de l'opération. Il n'y eut aucune complication dûe au cathéter intra-abdominal. Malgré une dose importante de 5-FU administrée dans la période post-opératoire immédiate, les effets secondaires systémiques furent minimes. La mortalité globale au cours de l'hospitalisation fut de 1.85% et sans relation avec la chimiothérapie. Ce taux est remarquablement inférieur à ceux rapportés par de multiples centres ou dans la littérature. Il est l'expression d'un progrès dans la technique chirurgicale et les soins pré- et postopératoires. 378 malades (groupe de contrôle: 187, perfusés: 191) ont permis une évaluation exacte de la récidive et de la survie. Après un suivi moyen de 24 mois, il a été observé 43 récidives dans le groupe de contrôle et 34 dans le groupe traité (p〈0.05). Des métastases hépatiques furent découvertes 18 fois dans le premier groupe et 14 fois dans le second. Les malades moururent de récidive 25 fois dans le groupe de contrôle et 18 fois dans le groupe traité par perfusion. En raison du faible nombre des récidives dans cette étude il est trop tôt pour tirer des conclusions sur la durée de la survie. Plusieurs essais contrôlés de traitement par perfusion portale sont en cours. Ils montrent également que la méthode peut être pratiquée et ils suggèrent que la perfusion hépatique par un agent cytotoxique peut réduire le nombre des métastases sans augmenter significativement la morbidité et la mortalité. Il est trop tôt cependant pour recommander la pratique courante de cette méthode. Elle reste sous essai clinique contrôlé et doit s'appliquer seulement à partir de protocoles prospectifs bien définis.
    Abstract: Resumen Las metástasis hepáticas de origen colorrectal se originan en células malignas que ingresan a la circulación venosa portal. Cuatro cientos sesenta pacientes de 7 instituciones participantes han sido introducidos a un ensayo clínico prospectivo y aleatorizado para determinar el valor de la terapia adyuvante con perfusión venosa portal en la prevención de las metástasis hepáticas después de cirugía colorrectal curativa. Mediante aleatorización preoperatoria, los pacientes fueron asignados a un grupo manejado con cirugía solamente (grupo control) o al grupo de infusión portal del hígado con 5-fluoruracilo (500 mg/m2 diarios × 7 en infusión continua por los 7 primeros días postoperatorios) y mitomicina-C (10 mg/m2 por 24 horas postoperatorias como infusión de 2 horas). El catéter venoso portal fue colocado a través de cualquier rama del sistema venoso mesentérico en el curso de la laparotomía para el tumor primario. Con el uso del abordaje transabdominal no se han presentado complicaciones relacionadas con el catéter. A pesar de la elevada dosis acumulativa de 5-FU administrada en el periodo postoperatorio inmediato, los efectos sistémicos han sido mínimos. La tasa global de mortalidad hospitalaria en este estudio es de 1.85% y no aparece afectada por la terapia adjuvante. Esta tasa es considerablemente menor que la informada en ensayos multicéntricos y en la literatura quirúrgica y es indicativa de un avance en la técnica operatoria y en el manejo pre-/postoperatorio de los pacientes en este tipo de cirugía electiva. Tres cientos setenta y ocho pacientes (187 del grupo control, 191 del grupo de infusión) son susceptibles de valoración total en cuanto a recurrencia y supervivencia. Después de un seguimiento promedio de 24 meses, se han presentado 43 recurrencias en el grupo control y 34 en el grupo de infusión (p 〈0.05). Se presentaron metástasis hepáticas en 18 pacientes del grupo control y en 14 del grupo de infusión. Veinte y cinco pacientes en el grupo control y 18 en el grupo de infusión murieron como consecuencia de enfermedad recurrente. Debido al bajo número de recurrencias observado en el estudio, es todavía demasiado temprano para derivar conclusiones en cuanto a supervivencia. Varios ensayos clínicos controlados utilizando infusión portal adyuvante están siendo realizados; también han demostrado la factibilidad de este enfoque y sugieren que la infusión hepática con agentes citotóxicos puede reducir la incidencia de metástasis hepáticas sin que haya un aumento significativo en la morbilidad o mortalidad. Sin embargo, es todavía muy pronto para poder recomendar la terapia adyuvante con infusión portal por fuera del marco de los ensayos clínicos y tal forma de tratamiento debe permanecer restringida a protocolos prospectivos debidamente diseñados.
    Notes: Abstract Liver metastases of colorectal origin arise from malignant cells entering the portal venous circulation. Four hundred sixty patients from 7 participating institutions have been entered in a prospective randomized trial to assess the value of adjuvant portal venous infusion to prevent liver metastases following curative colorectal cancer surgery. By preoperative randomization, patients were assigned to surgery alone (control arm) or to portal liver infusion with 5-fluorouracil (5-FU) (500 mg/m2 daily × 7, continuous infusion during the first 7 postoperative days) and mitomycin C (10 mg/m2, 24 hours postoperatively as a 2-hour infusion). A portal venous catheter was placed through any side branch of the mesenteric venous system during laparotomy for the primary tumor. Using the transabdominal route, there have been no catheter-related complications. Despite a large cumulative dose of 5-FU given during the immediate postoperative period, the systemic side effects were minimal. Overall hospital mortality in this study was 1.85% and was not influenced by the adjuvant treatment. This rate is considerably lower than that reported by previous multicenter trials and by the surgical literature, and it indicates an advance in surgical technique and pre-/postoperative patient management in this type of elective surgery. Three hundred seventy-eight patients (187 controls, 191 infusion patients) are completely evaluable for recurrence and survival. After a median follow-up of 24 months, 43 recurrences have been observed in the control group and 34 in the infusion group (p〈0.05). Liver metastases were present in 18 control patients and in 14 infusion patients. Twenty-five patients in the control group and 18 patients in the infusion group died of recurrent disease. Due to the low number of recurrences in this study, it is too early to draw survival conclusions. Several controlled trials using adjuvant portal infusion are in progress. They also showed the feasibility of this approach and they suggested that adjuvant cytotoxic liver infusion may reduce the incidence of liver metastases without significantly increasing morbidity and mortality. It is too early, however, to recommend adjuvant portal infusion outside a clinical trial setting and such treatment should still be restricted to well-designed prospective protocols.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 186 (1964), S. 190-196 
    ISSN: 1432-1459
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Das Vorkommen von Ribonucleinsäure in Hypophysentumoren wird cytophotometrisch an mit Gallocyanin-Chromalaun gefärbten Schnitten untersucht. Hierbei ergibt sich in den Zellen der aktiven oder Mischtypadenome im Gegensatz zu den inaktiven Geschwülsten eine deutlich gesteigerte Cytoplasmabasophilie. Diese Ergebnisse unterstreichen die Unzulänglichkeit der bisherigen Nomenklatur der Hypophysenadenome.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 30 (1960), S. 340-343 
    ISSN: 1432-2242
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Zusammenfassung In umfangreichen Freiland- und Laboruntersuchungen, auf deren Methodik hingewiesen wird, wurden kultivierte südamerikanische Arten und Herkünfte aus dem Sortiment des Instituts für Pflanzen züchtung Groß-Lüsewitz (G-LKS) auf ihr Verhalten gegenüber dem Krebsbiotyp G1 (Gießübel) untersucht. Insgesamt wurden 576 Herkünfte —S. curtilobum 2, ssp.andigenum-tuberosum 489, 2n=24 chromosomige kultivierte Species 85 — mit 1687 verschiedenen Genotypen untersucht. Von ssp.andigenum-tuberosum waren 25% und von den 2n=24 chromosomigen Species 13% der geprüften Genotypen resistent. Es wird darauf hingewiesen, daß durch diese Untersuchungen für die Kartoffelzüchtung ein neues beachtliches Genreservoir erschlossen wurde und daß es sich vermutlich vorerst erübrigt, aufwendige Arbeit auf der Basis resistenter Wildarten zur Züchtung krebsbiotypenresistenter Kartoffeln zu leisten.
    Type of Medium: Electronic Resource
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  • 20
    facet.materialart.
    Unknown
    Berlin : Periodicals Archive Online (PAO)
    Orientalistische Literaturzeitung. 80:6 (1985:Nov./Dez.) 573 
    ISSN: 0030-5383
    Topics: Linguistics and Literary Studies , Ethnic Sciences , History
    Notes: Besprechungen
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