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  • 1975-1979  (5)
  • 1970-1974  (47,024)
  • 1973  (47,024)
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  • 101
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Repression of the sporulation ability ofSaccharomyces cerevisiae by glucose present in the presporulation medium was studied. Glucose lowered sporulation ability when added to the presporulation medium containing yeast extract but did not do so when added to the presporulation medium without glucose. The glucose-repressed sporulation ability was recovered by the addition of cyclic AMP, and theophylline or caffeine to the presporulation culture. Theophylline promoted the action of cyclic AMP, but caffeine did not. The effect of caffeine to reverse glucose repression was greater than that of cyclic AMP and theophylline.
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  • 102
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Partially purified fructose diphosphatase from the obligate chemolithotroph,Thiobacillus neapolitanus has been characterized, and some of its regulatory properties described. The enzyme had a high effinity for its substrate, but was inhibited by substrate at concentrations above 1 mM. The enzyme had an absolute requirement for a divalent cation. In the absence of EDTA there was a single pH optimum in the alkaline range between 8.5 and 9.5; in the presence of EDTA there was considerable was activity at both neutral and alkaline pH. This diphosphatase was inhibited by AMP at 10−4 M or greater-, the lower the pH, the greater the AMP inhibition. Treatment of the enzyme with 5×10−5 Mpara hydroxy mercuribenzoate allowed retention of full catalytic activity while abolishing considerable AMP inhibition. Exposure of the enzyme to several concentrations of urea had no effect on the AMP inhibition. Homocystine (0.06 mM) and coenzyme A (0.1 mM) had no effect. At 1 mM, PEP caused 60% inhibition, 2, 3-diphosphoglyceric acid produced 26% inhibition, and pyruvate had no effect.
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  • 103
    Electronic Resource
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    Springer
    Archives of microbiology 93 (1973), S. 287-294 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary By taking special precautions it was possible to obtain dispersed growth of the filamentous sewage fungus Fusarium aquaeductuum in a chemostat. The growth followed the Monod theory. However, there appeared to be slight anomalies in maximum specific growth rate and yield factor. An extremely low K s value of 0.3 mg glucose/l was found which is suggested to be of ecological significance for the occurrence of the organism in polluted, yet oxygen rich rivers.
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  • 104
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The capsule of Klebsiella pneumoniae type I and slime of Enterobacter aerogenes strain A3 (SL) was examined by electron microscopy using the freeze etch technique. The capsules of K. pneumoniae were found to be composed of several layers of polysaccharide 10 nm thick; while the polysaccharide slime of E. aerogenes strain A3 (SL) was found to be composed of a diffuse network of fibrils. This work represents the first effort to visualize the replica of the unfixed, partially hydrated bacterial capsule or slime in the electron microscope. The slime of E. aerogenes strain A3 (SL) which was purified, and then freeze etched, resembled the layered structure of the capsule of K. pneumoniae. It is suggested that the charge or dielectric constant of the slime polysaccharide polymers was altered during purification, thereby permitting the layering to occur.
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  • 105
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. A number of motility mutants derived from the gliding bacterium Cytophaga columnaris were obtained by allowing motile cells to spread from an inoculated area on an agar plate and then removing cells from the center of the inoculated area. This procedure was repeated ten times. Suspensions of cells resulting from this selection procedure were spread on agar plates, and colonies which lacked the spreading edges typical of wild-type cells were picked for further study. 2. Mutants were examined in slide cultures, on agar plates under various conditions of incubation, and by electron microscopy. 3. Two classes of motility mutants were isolated. Cells of one class are only nonmotile under certain conditions of incubation, whereas cells of the second class are nonmotile under all conditions tested. One mutant of this second class lacks a system of fibrils which is present in surface layers of cells of the parent strain.
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  • 106
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A crude cell envelope suspension has been prepared from Proteus mirabilis after osmotic shock of penicillin-induced spheroplasts. Employing discontinuous sucrose gradients this cell envelope suspension can be fractionated into four fractions. Besides a pellet of remaining spheroplasts and an intermediate fraction with mixed composition a highly purified cytoplasmic membrane fraction and an outer membrane fraction have been obtained. The cytoplasmic membrane fraction is not contaminated with mucopeptide or outer membrane material. It has a buoyant density of 1.13 g/ml and a protein content of 38%. The specific activities of formate dehydrogenase and nitrate reductase and the content of cytochrome b1 have increased sixfold in comparison with the crude cell envelope suspension. The outer membrane fraction contains only few contaminations with cytoplasmic membrane components and with mucopeptide. The gradient fractions have been characterized by electron microscopy and by polyacrylamide gel electrophoresis.
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  • 107
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An Escherichia coli 15 strain has been constructed which contains, in addition to the plasmids inherent to E. coli 15 (P 1-like DNA and minicircular DNA), the colicinogenic factor E1 (Col E1). Whereas the P 1-like DNA of E. coli 15 is unaffected by the uptake of the colicin plasmid, the number of copies of minicircular DNA of E. coli 15 decreases and an equivalent amount of Col E1 DNA becomes established in the cell. The ratio between these two small plasmids is dependent on the growth temperature. The mode of replication of minicircular DNA and Col E1 DNA is very similar, but is different in various respects from that of the P 1-like plasmid: 1. Both small plasmids continue to replicate in the presence of chloramphenicol, whereas the replication of P 1-like DNA stops like the chromosomal DNA. 2. Rifampicin inhibits the synthesis of both small plasmids rather rapidly. The replication of P 1-like DNA continues during the remaining replication cycle of the chromosome in the presence of rifampicin. 3. The replication of Col E1 DNA and of the minicircular DNA still proceeds at elevated temperatures (45–50°C), whereas little or no incorporation of 3H-thymidine into P 1-like DNA is observed at these temperatures. 4. Mutants have been obtained, which show altered properties in the maintenance and replication of the plasmids without being affected in the replication of the chromosomal DNA. In all these mutants the replication and (or) maintenance of the minicircular DNA of E. coli 15 and Col E1 DNA is affected in the same way, but not that of the P 1-like plasmid.
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  • 108
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Intact cells obtained from Thiobacillus denitrificans grown autotrophically with thiosulfate as the oxidizable substrate and nitrate as the final electron acceptor catalyzed the reduction of nitrate, nitrite and nitric oxide stoichiometrically to nitrogen gas with the concomitant oxidation of thiosulfate. In addition, nitrous oxide was also capable of acting as the terminal oxidant of the respiratory chain with thiosulfate as the reductant. The anaerobic oxidation of thiosulfate by NO3 -, NO, and N2O was sensitive to the flavoprotein inhibitors, antimycin A or NHQNO, and cyanide or azide thus, implicating the participation of flavins, and cytochromes of b-, c-, and a-types in the denitrification process. The nitrite reductase system, however, was not markedly affected by the electron transport chain inhibitors. The experimental observations suggest that the dissimilatory nitrate reduction in the chemoautotroph T. denitrificans involves nitrite, nitric oxide, and nitrous oxide as theintermediates with nitrogen gas as the final reduction product.
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  • 109
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung In homokaryotischen und in dikaryotischen Mycelien der Basidiomyceten wird das Volumen des prämitotischen Kernes dadurch reduziert, daß der eigentliche Teilungskern von einem membranumgebenen Restkern abgetrennt wird. Da die Kernmembran während der gesamten Mitose persistiert, arbeitet der Spindelapparat intranucleär.
    Notes: Summary In homokaryotic as well as in dikaryotic mycelia of Basidiomycetes the volume of the premitotic nucleus is reduced by separating the division nucleus from a residual nucleus which is surrounded by a membrane. For the nuclear membrane persists throughout the mitosis the spindle apparatus acts intranuclear.
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  • 110
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    Archives of microbiology 94 (1973), S. 359-364 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The yeast,Protomyces inundatus was sensitive to griseofulvin. When griscofulvin was added to exponentially growing cultures their turbidities increased at the same rate as control cultures for one doubling and then there was a second, more protracted doubling of turbidity before growth eventually stopped. However, the viability of these cultures decreased exponentially after the addition of griseofulvin. The inhibitory effect of griseofulvin was not reversed by the addition of various mono-nucleotides.
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  • 111
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    Archives of microbiology 94 (1973), S. 365-371 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Incorporation of tritiated glucose into cell walls of growingSaccharomyces cerevisiac andSchizosaccharomyces pombe was studied using electron microscopic autoradiography. The pattern and the extent of labelling ofS. cerevisiae cell walls depended on the cell stage in the cell cycle. Quantitative evaluation of autoradiographs showed that the highest rate of wall synthesis took place during bud growth. The incorporation of new material into the wall of growing bud showed an increasing rate with the magnitude of the bud. The incorporation into the mother cell wall was almost negligible during bud growth. The rate of wall synthesis in double cells decreased during cell division. This period and that before new bud initiation was found to be the time of substantially reduced rate of wall replication inS. cerevisiae. A significant random incorporation was observed into the walls of post-division adult cells, both parental and daughter. The cell walls ofS. pombe were labelled almost exclusively at growing tips. The incorporation of tritiated carbohydrates into non-extensile regions ofS. pombe cell walls was found to be only about 5% of the total wall labelling.
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  • 112
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    Archives of microbiology 94 (1973), S. I 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 113
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    Archives of toxicology 30 (1973), S. 111-114 
    ISSN: 1432-0738
    Keywords: Diquat ; Reglone® ; Herbicide-Analytics ; Diquat ; Reglone® ; Herbicid-Analytik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Diquat wird durch den stark sauren Kationenaustauscher Permutit R S 40 aus dem Untersuchungsmaterial isoliert und anschlißend mit gesättigter Ammoniumchloridlösung eluiert. Die spektrophotometrische Gehaltsbestimmung erfolgt nach Reduktion der Verbindung zum grün gefärbten Radikal bei 379 nm.
    Notes: Abstract Permutit R S 40, an acid ion exchange resin, can be used to determine the herbicide Diquat. This compound is eluated by the ion exchange column with a cold saturated NH4 Cl solution. The spectrophotometric determination is carried through after reduction to a green colored radical.
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  • 114
    ISSN: 1432-0738
    Keywords: Trichloroethylene ; Inhalation ; Metabolism in Rats ; Trichloroethanol, Chloral Hydrate, Trichloroacetic Acid ; Methods of Determination ; Trichloräthylen ; Inhalation ; Stoffwechsel bei Ratten ; Trichloräthanol, Chloralhydrat, Trichloressigsäure ; Bestimmungsmethoden
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ratten wurden in akuten und subchronischen Inhalationsversuchen Trichloräthylen exponiert. Bei den 4stündigen Expositionen waren die Konzentrationen ca. 50 ppm bis 3160 ppm, im 14-Wochenversuch (täglich 8 Std) im MAK-Bereich (50 ppm). Das Verhalten von Trichloroäthylen und seiner Metabolite (Chloralhydrat, Trichloräthanol, Trichloressigsäure) in Atemluft, Blut und Harn wurde untersucht. Dazu wurden Methoden zur analytischen Bestimmung ausgearbeitet. Mit Ausnahme erhöhter Lebergewichte ergaben sich bei Ratten nach Inhalation einer TRI-Konzentration von ca. 55 ppm über 14 Wochen keine pathologischen Veränderungen. Die Lebervergrößerung als Folge einer Enzyminduktion wird diskutiert. Trichloroäthylen konnte im Blut nicht nachgewiesen werden, die Trichloräthanol- und Chloralhydrakontzentrationen veränderten sich nicht wesentlich. Die Trichloräthanolmenge im Harn stieg bis zur 10. Woche an, um dann allmählich abzunehmen. Dagegen blieb die Trichloressigsäurekonzentration ziemlich unverändert. Entsprechend verhielt sich das Verhältnis Trichloräthanol/Trichlor-essigsäure.
    Notes: Abstract In acute and subchronic inhalation studies rats were exposed to trichloroethylene. During the 4-h exposures the concentration was about 50 ppm to 3160 ppm and more, and in the 14-week study (8 h/day) within the range of the MAC (50 ppm). The behavior of trichloroethylene and its metabolites (chloral hydrate, trichloroethanol and trichloroacetic acid) in the expired air, blood and urine was investigated. For this purpose, analytical methods were developed. With the exception of elevated liver weights, the exposure to a trichloroethylene concentration of 55 ppm over a period of 14 weeks did not cause any pathological changes. The liver enlargement as a consequence of an enzyme induction is discussed. Trichloroethylene was not detectable in the blood, and the concentrations of trichloroethanol and chloral hydrate were not altered significantly. The urinary trichloroethanol excretion increased until the 10th week and then decreased slowly. In contrast, the trichloroacetic acid remained fairly constant. Corresponding results of the ratio TCE:TCA were found.
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  • 115
    ISSN: 1432-0738
    Keywords: Atropine ; Organophosphorus Compounds ; Phrenic Nerve ; Atropin ; Organophosphate ; N. phrenicus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Einzelfaserpräparaten des N. phrenicus der Ratte wurde die Wirkung einer Cholinesterasevergiftung durch Paraoxon und Soman auf die spontane Impulsfolge untersucht. Dabei ergab sich: 1. Paraoxon führte in Dosen von 0,12 mg/kg i.v. zu einer neuromuskulären Lähmung (Verschwinden der Muskelaktionspotentiale im Diaphragma) bei gleichzeitigem Anstieg der Entladungsfrequenz und der Spikezahlen in den inspirationsaktiven Phrenicus-Motoneuronen. 2. Nach Soman (0,06 mg/kg) sank die Entladungsfrequenz in Phrenicus-Einzelfasern ab. Auch in den Anfangsstadien der Vergiftung war keine Zunahme der Entladungsfrequenz nachweisbar. 3. Eine zusätzliche Anwendung von Atropin (1,0 mg/kg) führte sowohl bei Paraoxon- als auch bei Soman-vergifteten Tieren zu einer Verlängerung der Impulsabstände in den Phrenicus-Einzelfasern. Die Steigerung der Entladungsfrequenz bei der Paraoxonvergiftung fördert die Ausbildung einer neuromuskulären Lähmung nach dem Typ der Wedensky-Hemmung. Die initiale Senkung der Entladungsfrequenz nach Soman ist eine Er klärung für die Tatsache, daß bei dieser Organophosphatvergiftung die neuromuskuläre Lähmung erst bei stärkerer Einschränkung der peripheren Acetylcholinesteraseaktivität eintritt.
    Notes: Abstract The discharge pattern in single fibres of the phrenic nerve has been investigated in rats after inhibition of cholinesterase by the organophosphorus compounds paraoxon and soman. The results were as follows: 1. Doses of 0.12 mg/kg paraoxon intravenously produced a neuromuscular paralysis while the frequency and number of spikes in phrenic nerve increased. 2. Soman (0.06 mg/kg intravenously) caused a decrease in the frequency of phrenic discharges. 3. After application of atropine (1.0 mg/kg) the spike-interval in phrenic motoneurons was prolongated both in the paraoxon and soman intoxicated animals. The different effect of the organophosphorus compounds paraoxon and soman on frequency of phrenic motoneurons offers an explanation for the fact that after soman acetylcholinesterase must be more inhibited to achieve neuromuscular paralysis of the diaphragma than in the case of paraoxon intoxication. The increase in frequency of phrenic motoneurons promotes the appearance of Wedensky-inhibition while the prolongation in the distance of impulses would suppress the neuromuscular paralysis by organophosphates.
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  • 116
    ISSN: 1432-0738
    Keywords: Atropine ; N-Methylatropine ; Phrenic Nerve ; Respiration ; Atmung ; Atropin ; N-Methylatropin ; N. phrenicus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 78 narkotisierten, bivagotomierten Ratten wurde die Entladungsfrequenz inspirationsaktiver Einzelfasern vom N. phrenicus unter der Einwirkung von Atropin untersucht. Dabei ergab sich: 1. Atropin führte in Dosen von 0,6; 1,2; 2,4 und 4,8 mg/kg i.v. zu einer dosisabhängigen Verlängerung der Impulsabstände und zu einer Abnahme der Spikezahlen in inspirationsaktiven Phrenicus-Motoneuronen. Die Atmungsfrequenz war demgegenüber nach Atropin gesteigert. 2. Bei Stimulation der Atmung durch Anoxie (12 Vol.- % O2) oder Hypercapnie (5 Vol.- % CO2) war die erreichbare Steigerung der Entladungsfrequenz und die Erhöhung der Spikezahlen nach Atropin (1,0 mg/kg) absolut eingeschränkt, die relativen Änderungen waren iedoch in beiden Fällen vor und nach Atropinbehandlung gleich. 3. N-Methylatropin(1,0 mg/kg)zeigte keine Wirkung auf die Entladungsfrequenz im N. phrenicus. 4. Nach Denervation des Carotissinus war die Reaktion auf Atropin unverändert. Die unterschiedliche Wirkung von Atropin auf die Atmungstiefe (Zunahme der Impulsabstände, Abnahme der Spikezahlen) und auf die Atmungsfrequenz (Steigerung der Atmungscyclen pro Zeiteinheit) scheint nicht durch eine Beeinflussung der Chemoreception, sondern durch eine direkte Wirkung an der zentralen Atmungsteuerung zustandezukommen.
    Notes: Abstract The effect of atropine on discharge pattern of phrenic motoneurons was investigated in rats after vagotomy. The following results were obtained: 1. Atropine increased the distance of impulses, while the number of spikes was reduced. This effect was dose dependent for 0.6, 1.2, 2.4, and 4.8 mg/kg atropine injected intravenously. At the same time the frequency of respiration increased after administration of atropine. 2. Following atropine the effect of O2-deficiency (12 Vol.-%O2) or CO2-excess (5 Vol.-% CO2 on frequency of impulses and number of spikes was absolutely reduced, but both reactions were relatively unchanged. 3. N-Methylatropine did not influence the discharge pattern in phrenic motoneurons. 4. The effect of atropine on frequency of impulses was also demonstrable after denervation of carotid sinus. The different effect of atropine on depth of respiration (increase in the distance of impulses, reduction of spike number) and respiratory frequency is not elicited by alteration of chemoreception. The results indicate that atropine effects the discharge pattern of phrenic motoneurons by direct action on central respiratory regulation.
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  • 117
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    Archives of toxicology 30 (1973), S. 187-198 
    ISSN: 1432-0738
    Keywords: Plasma Iron Level ; Side Effect of Drugs ; Rat ; Amphetamine ; Chlorpromazin ; Haloperidolum ; Guanethidin ; Reserpine ; α-Methyltyrosine. ; Plasmaeisenspiegel ; Arzneimittelnebenwirkungen ; Ratte ; Amphetamin ; Chlorpromazin ; Raloperidol ; Guanethidin ; Reserpin ; α-Methyltyrosin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 4 Std nach einmaliger Gabe von 24 mg/kg d,l-Amphetamin i.p. kommt es bei Ratten zu einem Abfall des Eisens im Plasma um 40 bis 60 %. Die Reaktion ist nicht mit dem amphetaminbedingten Anstieg von Körpertemperatur und Skeletmuskelarbeit zu erklären, da sie durch Vorbehandlung mit α-Methyltyrosin, Chlorpromazin, Haloperidol, Guanethidin und Reserpin nicht unterdrückt werden kann. Jedes der zur Vorbehandlung verwandten Medikamente löst selbst bei entsprechend hoher Dosierung eine Hyposiderämie aus. 4 Std nach einmaliger Gabe von 200 mg/kg α-Methyltyrosin vermindert sich der Eisenspiegel im Plasma um 55 %, nach 10 mg/kg Chlorpromazin um 11 %, nach 5 mg/kg Haloperidol um 28 % und nach 20 mg/kg Guanethidin um 50 %. Dieser Effekt ist am ausgeprägtesten mit einer Plasmaeisenverminderung um 69 % 20 Std nach Gabe von 20 mg/kg Reserpin. Als möglicher Pathomechanismus der arzneimittelbedingten Hyposiderämie wird die Wirkung der untersuchten sämtlich zentralnervös aktiven Medikamente als “non-specific stressfull agents” sowie der durch ihre toxische Konzentration in Gang gesetzte Entgiftungsmechanismus im RES diskutiert.
    Notes: Abstract Four hours following a single dose of 25 mg/kg of d, 1-Amphetamine in rats, a 40 to 60 % drop of plasma iron level occurred. This reaction cannot be explained by the Amphetamine-induced rise in body temperature and motor activity, since when pretreated with α-Methyltyrosine, Chlorpromazin, Haloperidolum, Guanethidin and Reserpin this was not observable. All the drugs applied for pretreatment in adequately high doses also induced hyposideremia. Four hours following a single dose of 200 mg/kg of α-Methyltyrosine, plasma iron level was reduced by 55 %, after 10 mg/kg of Chlorpromazin by 11 %, after 5 mg/kg of Haloperidolum by 28 % and after 20 mg/kg of Guanethidin by 50 %. The most pronounced effect (69 % fall) was obtained by 20 hour pretreatment with 20 mg/kg of Reserpin. As possible pathomechanism of the drug induced hyposideremia the applied drugs may be regarded as “non-specific stressfull agents”, or as another possibility, the detoxifying mechanism in RES induced by toxic concentrations of the applied drugs can be considered as responsible for this phenomena.
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  • 118
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    Archives of toxicology 30 (1973), S. 215-226 
    ISSN: 1432-0738
    Keywords: Amanita phalloides ; Amanita species ; Hemolysins ; Phytohemagglutinins ; Amanita phalloides ; Amanita-Arten ; Hämolysine ; Phytohaemagglutinine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Phallolysin, das hochmolekulare Hämolysin ausAmanita phalloides, wurde in 42 verschiedenen Chargen grüner Knollenblätterpilze konstant und in hoher Aktivität nachgewiesen. Die Pilze waren an 19 verschiedenen Fundorten in 4 Jahren gesammelt worden. Wäßrige Extrakte von 12 weiterenAmanita-Arten wurden an Kaninchen-und menschlichen Erythrocyten auf hämolytische Aktivität geprüft. Wenn möglich wurden von jeder Art mehrere Chargen — insgesamt 99 — von verschiedenen Fundorten untersucht. Hämolysine wurden nachgewiesen inA. muscaria, A. gemmata, A. verna, A. citrina, A. porphyria, A. spissa, A. echinocephala und — konstant und in hoher Aktivität — inA. rubescens. Aus den vorliegenden und weiteren, noch unveröffentlichten Befunden ging hervor, daß das Hämolysin ausA. rubescens mit Phallolysin ausA. phalloides nicht identisch ist. A. muscaria-Extrakt führte zusätzlich zur Agglutination der Erythrocyten.
    Notes: Abstract Phallolysin, the high-molecular weight hemolysin fromAmanita phalloides, was present in high activity in each of 42 samples ofA. phalloides. The toadstools were collected in 19 different locations during a period of 4 years. Aqueous extracts of 12 furtherAmanita species of differing origin were tested for hemolytic activity. Several samples of each species — altogether 99 — were tested on rabbit and human erythrocytes. Hemolysins were present inA. muscaria, A. gemmata, A. verna, A. citrina, A. porphyria, A. spissa, A. echinocephala and invariably and in high activity inA. rubescens. According to the present results and to unpublished observations, the hemolysin ofA. rubescens differed from Phallolysin ofA. phalloides. The extracts ofA. muscaria also produced agglutination of red blood cells.
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  • 119
    ISSN: 1432-0738
    Keywords: Acetone ; Benzene ; Carbon Tetrachloride ; Halothane ; Toluene ; Trichloroethylene ; Mineral Oil ; Hydrocarbons ; Gasoline ; Aceton ; Benzol ; Tetrachlorkohlenstoff ; Halothan ; Toluol ; Trichloräthylen ; Mineralöl ; Kohlenwasserstoffe ; Benzin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Paraffinöl zeigt im Tierversuch — mit Ausnahme gegenüber dem Autobenzin - keinerlei Antidotwirkungen gegen Vergiftungen mit Aceton, Tetrachlorkohlenstoff, Trichloräthylen, Halothan, Benzol, Toluol. 2. Die Toxicität von normalem Autobenzin kann durch gleichzeitige Gaben von Paraffinöl auf ca. 60 % der Ausgangswerte gesenkt werden. Diese Wirkung ist zeitlich sehr begrenzt und nicht mehr nachweisbar, wenn Benzin- und Paraffinölgabe mehr als 15 bis 20 min auseinanderliegen. 3. Die Frage, welche Inhaltsstoffe im Benzin für die Antidotwirkung von Paraffinöl verantwortlich sind, kann noch nicht beantwortet werden. Fest steht bisher nur, daß die gesättigten aliphatischen Verbindungen ebenso wie Benzol und Bleitetraäthyl dabei keine Rolle spielen. 4. Paraffinöl kann nach diesen Ergebnissen nicht mehr als Antidot gegen die sog. organischen Lösungsmittel empfohlen werden. Über seine Abführwirkung als Gleitmittel hinaus hat es - ausgenommen bei Autobenzin - keinerlei Effekt.
    Notes: Abstract Mineral oil has no antidotal effects on acetone, benzene, carbon tetrachloride, halothane, toluene, or trichloroethylene poisoning. Experiments on mice show that the toxicity of gasoline only may be lowered to bout half the control values by simultaneous oral administration of mineral oil. This effect, however, was not demonstrable if the interval between gasoline and mineral oil administration exceeded 20 min, through it proved to be unimportant whether mineral oil was given before or after gasoline administration. The question as to which gasoline component is responsible for the antidotal effect of mineral oil cannot be answered as yet. Hexane, heptane, and octane may be excluded because of their very low toxicity. This is true also for the acute effects of tetraethyl lead. Additional experiments with benzene-heptane mixtures also excluded the possibility that benzene might be the compound on which mineral oil exerts its effects, though it is a component of gasoline and partially responsible for its higher toxicity. Furthermore, mineral oil was almost ineffective as an antidote to more toxic gasoline and this may find an explanation in its higher benzene content. Mineral oil as a consequence of these results has no place as antidote in the treatment of hydrocarbon poisoning.
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  • 120
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    Archives of toxicology 31 (1973), S. 7-12 
    ISSN: 1432-0738
    Keywords: Doxepin ; Intoxication ; Doxepin in postmortem Material ; Doxepin ; Vergiftung ; Doxepin in Autopsiematerial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine Doxepinvergiftung wird beschrieben einschließlich der pathologisch-anatomischen Befunde und einer Methode zur Isolierung von Doxepin im Obduktionsmaterial. UV-Spektrum, gaschromatographische Daten, Infrarot-und Massenspektren werden angegeben. Urinextrakte wurden dünnschicht-chromatographisch untersucht. Drei Metaboliten wurden entdeckt, aber noch nicht identifiziert. Die Resultate der toxikologischen Analysen sind in Tabellen wiedergegeben.
    Notes: Abstract A case of doxepin intoxication is reported. Relevant autopsy findings are mentioned and an extraction procedure for the determination of doxepin in autopsy material is described. UV-spectrum, gas chromatography data, infrared and mass spectra of doxepin are given. Thin-layer chromatography of urine extracts gave three metabolites. These are not yet identified. The results of the toxicological investigations are presented.
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  • 121
    ISSN: 1432-0738
    Keywords: DDT ; Rat Liver Mitochondria ; ATPase Activity ; DDT ; Rattenlebermitochondrien ; ATPase-Aktivität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß des DDT und semer Stoffwechselprodukte auf die ATPase der Rattenlebermitochindrien wurde geprüft. Eine Stimulierung der ATPase-Aktivität durch DDT und seine Metaboliten an intakten Mitochondrien wurde festgestellt; diese Stoffe sind dagegen ohne jede Wirkung auf geschädigte mitochondriale Präparationen. Auf einen Entkopplungsmechanismus der oxydativen Phosphorylierung wird hingewiesen, der für die toxische Wirkung der Pesticide im Säugetier verantwortlich sein kann.
    Notes: Abstract The effect of DDT and its main metabolites on ATPase activity in rat liver mitochondria was studied. These compounds stimulated ATPase activity in intact mitochondria of rat liver and had no effect on ATPase activity in damaged mitochondria. This suggests that the uncoupling of the oxidative phosphorylation in mitochondria may be responsible for the toxic effect of DDT in mammals.
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  • 122
    ISSN: 1432-0738
    Keywords: Recosen® Protection ; Tri-Ortho-Cresyl Phosphate Intoxication ; Oxotremorine ; Verhütung durch Recosen® ; Intoxikation mit Tri-ortho-cresyl-phosphat ; Oxotremorin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Recosen® verhindert die Entstehung von Paralysis bei Hühnern, hervorgerufen durch Tri-ortho-cresyl-phosphat.
    Notes: Abstract Recosen® protects cocks from paralysis caused by tri-ortho-cresyl phosphate.
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  • 123
    ISSN: 1432-0738
    Keywords: o-Chlorobenzylidene Malononitrile ; Malononitrile ; Potassium Cyanide ; Cyanide Formation ; Thiocyanate Excretion ; Sodium Thiosulfate ; Sodium Nitrite ; Cobalt-EDTA ; o-Chlorbenzylidenmalononitril ; Malononitril ; Kaliumcyanid ; Cyanidbildung ; Rhodanidausscheidung ; Natriumthiosulfat ; Natriumnitrit ; Kobalt-EDTA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Mäuse wurden mit o-Chlorbenzylidenmalononitril (CS) durch i.p. Injektion (0,5 LD50) oder Aerosol (20000 mg min−1 m−3) behandelt. Eine gesteigerte Ausscheidung von Ehodanid im Harn wurde beobachtet, was eine Umwandlung von CS in Cyanid in vivo andeutet. Bestimmungen von Cyanid in Vollblut bestätigten eine schnelle Bildung von Cyanid nach der Injektion von CS. Eine Korrelation zwischen dem Verlauf der Cyanidkonzentrationen und den Vergiftungssymptomen der Tiere wurde beobachtet. Die Toxicität von injiziertem CS wurde bei prophylaktischer Behandlung mit Thiosulfat deutlich reduziert, während Nitrit eine geringere und Co2EDTA keine Wirkung hatte. Die Ausscheidung von Rhodanid, die Cyanidkonzentrationen des Blutes und die Wirkung der Antidote wurde auch bei Behandlung mit 0,5 LD50 von Malononitril und Kaliumcyanid untersucht. Die Bedeutung der Cyanidbildung für die Toxicität von CS wurde diskutiert.
    Notes: Abstract Mice received o-chlorobenzylidene malononitrile (CS) by i.p. injection (0.5 LD50) or by aerosol exposure (20,000 mg min−1 m−3). Increased excretion of thiocyanate in the urine was observed, indicating a transformation of CS to cyanide in vivo. Determinations of cyanide in whole blood after i.p. administration of CS verified a rapid transformation of the agent to cyanide. A correlation between the time course of cyanide levels and symptoms was observed. Toxicity of injected CS was significantly reduced by pretreatment with thiosulfate, slightly reduced by nitrite and not affected by Co2EDTA. Thiocyanate excretion, blood cyanide levels and protective effect of antidotes were also evaluated after administration of 0.5 LD50 of malononitrile and potassium cyanide. The importance of cyanide formation for the toxicity of CS is discussed.
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  • 124
    ISSN: 1432-0738
    Keywords: Diazepam ; Intoxication ; Drug Addicts ; Diazepam ; Intoxikation ; Drogenabhängige
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Über eine zum Tode führende Vergiftung mit Diazepam (Valium®) bei einem jugendlichen Drogenabhängigen wird berichtet. Aus der Verteilung des Valiums und seines Demethylierungsmetaboliten in den Körperflüssigkeiten, Geweben und Organen wird auf die eingenommene Valiumdosis zurückgeschätzt. Die toxische Wirkung des Valiums in Verbindung mit anderen möglichen Faktoren, wie Alkohol und Unterkühlung, wird diskutiert.
    Notes: Abstract Fatal intoxication of a young drug addict with Diazepam is reported. The amount of Diazepam taken is estimated from the distribution of Diazepam and its demethylated metabolite in body fluids, tissues, and organs. The toxic effect of Diazepam in connection with other possible factors such as alcohol and cooling is discussed.
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  • 125
    ISSN: 1432-0738
    Keywords: DDT ; Rat Liver Mitochondria ; DDT Metabolites ; Glutamate Dehydrogenase ; DDT ; Rattenlebermitochondrien ; DDT Metabolite ; Glutaminsäuredehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von DDT, DDE, DDOH und DDA auf die Oxydation von NADH, Glutamat, β-Hydroxybutyrat und Succinat in Rattenlebermitochondrien wurde untersucht. Der Einfluß dieser Stoffe auf die Aktivität der Glutaminsäuredehydrogenase wurde ebenfalls geprüft. Es wurde festgestellt, daß DDT und seine Metabolite die Oxydation der NAD-abhängigen Substrate in intakten sowie in den Ultraschall-behandelten Mitochondrien hemmen. Die wasserlöslichen Metabolite von DDT (DDOH und DDA) stimulieren die Oxydation von Succinat in intakten, aber nicht in den Ultraschall-beschädigten Mitochondrien; DDOH und DDA hemmen auch die Aktivität der Glutaminsäuredehydrogenase. Auf Grund dieser Befunde wurde angenommen, daß DDT und seine Metabolite auf die mitochondriale Atmungskette zwischen NADH und Ubichinon wirken, die Glutaminsäuredehydrogenase hemmen und die oxydative Phosphorylierung entkoppeln können.
    Notes: Abstract The effects of DDT, DDE, DDOH and DDA on the oxidation of NADH, glutamate, β-hydroxybutyrate and sucoinate by rat liver mitochondria were investigated. The influence of these compounds on the activity of purified liver glutamate dehydrogenase was also checked. It was found that DDT and all those of its metabolites investigated inhibited oxidation of NAD-linked substrates by both intact and sonicated mitochondria. The water-soluble metabolites of DDT (DDOH and DDA) stimulated succinate oxidation by intact but not by sonicated mitochondria, and inhibited the activity of glutamate dehydrogenase. It is concluded that DDT and its metabolites may affect mitochondrial respiratory chain between NADH and CoQ, inhibit glutamate dehydrogenase, and uncouple oxidative phosphorylation.
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  • 126
    ISSN: 1432-0738
    Keywords: ALA-D ; Lead ; Glutathione ; Free and Blocked Part of ALA-D ; ALA-D ; Blei ; Glutathion ; Freier und blockierter Teil von ALA-D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Weil sich in Tierversuchen bei niedriger Bleibelastung Tendenzen zur Normalisierung der bleiempfindlichen Parameter zeigten, wurde dieser als Adaptation interpretierte Vorgang in vivo und in vitro geprüft. Blei hemmte in vitro die Delta-Aminolävulinsäure-Dehydratase (ALA-D) dosisabhängig und nicht kompetitiv oder irreversibel kompetitiv. Der durch Blei blockierte Anteil der ALA-D war bei vermehrt bleikontaminierten Versuchstieren höher als bei Kontrolltieren. Dagegen bestanden im freien Anteil keine signifikanten Unterschiede zwischen den beiden Gruppen. Die Normalisierung des freien Anteils erfolgte über eine Neusynthese des Enzyms. Somit erscheint die Messung des durch Blei inaktivierten, durch Glutathion reaktivierten Anteils dieses Fermentes eher geeignet, eine chronische Bleieinwirkung festzustellen, als die Messung der möglicherweise wieder normalisierten ALA-D-Aktivität.
    Notes: Abstract Because there were tendencies for normalization of lead-sensitive parameters in animals with low lead burdens, these phenomena were examined in vivo and in vitro. Lead inhibited the enzyme delta-aminolevulinic acid dehydratase (ALA-D) dose-dependently and not competitively or irreversibly competitively in vitro. The lead-blocked portion of ALA-D could be reactivated at least partially by glutathione. This part was higher in lead-contaminated animals than in the control group, though there were no significant differences in the free part of the enzyme. The free part of the enzyme was normalized by a resynthesis of the molecule. Therefore the determination of the lead-blocked part and the part reactivated by glutathione, seemed more suitable for determining the chronic lead burden than the measurement of a possible adapted total activity of ALA-D.
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  • 127
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    Archives of toxicology 31 (1973), S. 193-196 
    ISSN: 1432-0738
    Keywords: Methyprylon ; Tissue-Extraction ; Gaschromatography ; Methyprylon ; Gewebsextraktion ; Gaschromatographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird eine gaschromatographische Methode beschrieben, Methyprylon in Gewebeteilen nachzuweisen. Als Extraktionsmittel wird Chloroform benutzt, Reinigungsschritte sind nicht erforderlich. Die Ausbeute beträgt 95,2±8,6% (p〈0,05).
    Notes: Abstract A gas-chromatographic method for the estimation of methyprylon in animal tissues is reported. Chloroform is used for the extraction. Purification is not necessary. The recovery is 95.2±8.6% (p〈0.05).
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  • 128
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    Biological cybernetics 13 (1973), S. 1-5 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The recognition of textures involves multiple local filtering and subsequent averaging of the image to produce a feature space in which textures are represented as cluster centers. Results are presented for a two variate algorithm involving the features “brightness” and “roughness”. Both regular and random textures generated by program are used. The final result of classification is expressed in terms of the original textures: the computer “paints” what it has seen — and makes rather understandable errors at the borders between different textures.
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  • 129
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    Biological cybernetics 13 (1973), S. 24-29 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract A neural net model of discrete populations of formal neurons have been constructed to study evoked potentials based on our previous simulation studies (Anninos, 1972). Some interesting results came up from the examination of our findings regarding the latencies and the period of the cyclic activity of the evoked potentials. In fact, the different successive latencies for the five identical stimuli and the different periods for each of the cyclic activities, all are consequences of inhibitory and excitatory influences from a large neuronal population. Furthermore, such behavior of the system is not only related to the unknown neuronal population but was also substantially altered by what occurred in other systems at the time of stimulus, or prior to it.
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  • 130
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    Biological cybernetics 13 (1973), S. 6-23 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Zusammenfassung Ausgehend von den elektrischen Vorgängen an der erregbaren Membran wird der Kodierungsprozeß untersucht. Eine Leitwert-Potential-Beziehung als Bedingung für die Impulsauslösung gestattet eine detaillierte Analyse bei verschiedenen Eingangssignalen. Bei der Ansteuerung mit einem Leitwert erfolgt die Sättigung der Umsetzungskennlinie des Kodierers erheblich früher als bei Stromeingang. Auch das Phänomen des over-stretch wird vom Modell erklärt. Zur Kleinsignalanalyse wird die Theorie der Systeme mit zeitvariablen Parametern angewendet. Die Übertragungsfunktion des Kodierers setzt sich in vielen Fällen additiv aus denen mehrerer Leckstrom-Integratoren mit unterschiedlichen Zeitkonstanten zusammen. Auch die teilweise beobachtete Abhängigkeit der Parameter von der Trägerfrequenz wird modellmäßig erfaßt. Die Adaptationsvorgänge im Kodierer beruhen auf einer intracellulären Anhäufung von Natriumionen während der Impulsabgabe. Die Aktivierung der Ionenpumpe bewirkt einen zusätzlichen Stromfluß, wodurch sich die abgegebene Impulsfrequenz verringert. Bei größeren Ansteuerungen trägt die durch langsame Kalium- und Natriuminaktivierung auftretende Verschiebung der Impulsauslösecharakteristik ebenfalls zur Adaptation bei. Die Betrachtungen, obwohl allgemeingültig für den biologischen Mechanismus der Impulsentstehung und Kodierung, wurden im Rahmen der Arbeit nur auf experimentelle Befunde an Receptorneuronen begrenzt. Für das Motoneuron und Neuronen in verarbeitenden Schichten müssen zusätzlich die Summation synaptischer Vorgänge und statistische Verknüpfungen zwischen Eingangs- und Ausgangssignal berücksichtigt werden.
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  • 131
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Starting with the assumption that the output of a biological transducer is the linear sum of discrete waveshapes, then under appropriate conditions, such a system may be modelled by a transfer function whose input is a train of delta functions. The transfer function is obtained by averaging over the population of possible waveshapes. The representation of the input as a train of delta functions facilitates the calculation of its frequency power spectrum. A number of examples of possible physiological interest are given.
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  • 132
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    Biological cybernetics 13 (1973), S. 53-54 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
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  • 133
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The introduction (A) is followed by parts B and C in which active movements of the tibia are recorded from intact legs and legs with cut receptor tendons (tendon of the femoral chordotonal organ). For this purpose the femur is fixed and then either the movement of the freely moving tibia is filmed or the force produced by the fixed tibia is measured directly. Leg movements caused by touching the abdomen (active movements) are faster than movements which are caused by stretching and releasing the femoral chordotonal organ in inactive animals. After an active movement the return to the starting-point is similar to that following a passive displacement: the speed of the backward movement is very low in intact legs, but relatively high in legs with cut receptor tendons. In intact legs the speed of the return to the starting-point shows a correlation between active and passive movements. A preliminary discussion of these movements is given in (D). It is followed in Section E by a description of the movements of the femur-tibia-joint of intact legs and legs with cut receptor tendons in free-walking animals. Cutting the receptor-tendon does not enlarge the amplitude very significantly. In Section F the receptor tendon is sinusoidally moved during active movements. The result of such an experiment upon inactive animals is quite different. No reaction can be observed during active movements at that phase position for which the response occures in inactive animals. But there is an alternative reaction with the same frequency as the stimulus. In active animals the amplitude of the reaction is very irregular, but normally larger than in inactive animals. Sometimes one reaction is omitted or there is more than one reaction per stimulus-cycle. The phase-shift is significantly larger than in inactive animals. In Section D a hypothesis for the control of active movements is discussed. According to this hypothesis the control system of the “Kniesehnenreflex” is switched off during active movements. The set-point of the system (the starting-point) is not altered by an active movement. The beginning of flexion and/or extension of the femur-tibia-joint and the maximum speed of the movements are at least partially influenced by the femoral chordotonal organ. The amount of this influence is variable.
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  • 134
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    Biological cybernetics 13 (1973), S. 81-94 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract This paper pursues three basic definitions of comparative information motivated by various theories of information. The first definition involves the ordering of experiments according to a qualitative relation “not more informative than”, the second is derived from measure-theoretic properties of information without probability leading to a construction of a partially ordered algebra of information, the third is based on a particular aspect of qualitative semantic information involving the ordering of propositions according to their information content. This approach leads to a Boolean interpretation of informative propositions generating a qualitative probability structure. Some ways are discussed how to represent informative propositions by compatible normed information measures, leading to a measure of probability in terms of information.
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  • 135
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    Topics: Biology , Computer Science , Physics
    Notes: Abstract It is proposed that distinct anatomical regions of cerebral cortex and of thalamic nuclei are functionally two-dimensional. On this view, the third (radial) dimension of cortical and thalamic structures is associated with a redundancy of circuits and functions so that reliable signal processing obtains in the presence of noisy or ambiguous stimuli. A mathematical model of simple cortical and thalamic nervous tissue is consequently developed, comprising two types of neurons (excitatory and inhibitory), homogeneously distributed in planar sheets, and interacting by way of recurrent lateral connexions. Following a discussion of certain anatomical and physiological restrictions on such interactions, numerical solutions of the relevant non-linear integro-differential equations are obtained. The results fall conveniently into three categories, each of which is postulated to correspond to a distinct type of tissue: sensory neo-cortex, archior prefrontal cortex, and thalamus. The different categories of solution are referred to as dynamical modes. The mode appropriate to thalamus involves a variety of non-linear oscillatory phenomena. That appropriate to archior prefrontal cortex is defined by the existence of spatially inhomogeneous stable steady states which retain contour information about prior stimuli. Finally, the mode appropriate to sensory neo-cortex involves active transient responses. It is shown that this particular mode reproduces some of the phenomenology of visual psychophysics, including spatial modulation transfer function determinations, certain metacontrast effects, and the spatial hysteresis phenomenon found in stereopsis.
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  • 136
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    Biological cybernetics 13 (1973), S. 223-227 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract A general characterization of multi-input movement detection models is given in terms of the Volterra series formalism. When nonlinearities of order higher than the second are negligible, an n-input system can be decomposed into a set of 2-input systems, summing linearly. For a (symmetrical) 2-input system which has significant nonlinearities only up to the second order, the correlation model is its most general expression, if the infinite time average of the output is taken. Specific observations from optomotor experiments (e.g. phase invariance and contrast frequency dependence) can be interpreted in a general way in terms of properties of the Volterra representation.
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  • 137
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    Topics: Biology , Computer Science , Physics
    Notes: Abstract Normal subjects and cerebellar patients were instructed to arrest “as soon as possible” a ballistically initiated flexion movement of the forearm. The intentional actions consist essentially of a downward torque, the peak value of which has almost a constant latency (about 200 msec) from the beginning of the movement. A variable number of oscillations precede the arrest of the movement, the characteristics of which depend on the initial velocity of the flexion and on the mass with which the forearm is loaded. The motor commands responsible for the intentionally produced downward torque are controlled centrally as to leave the ratio between the peak values of the angular velocity which precede and follow the peak of the torque almost constant, under all conditions. To describe the oscillations a simple analytical model was proposed which includes the mechanical as well as the reflex factors, the latter under the form of a delayed velocity term. The satisfactory fitting of this model to the experimental findings permitted to establish the following points: 1. The oscillations are sustained by both a mechanical and a reflex stiffness. The contribution of the reflex loop is however quantitatively dominant since it accounts for about 75% of the inertial torque. It is fairly constant over the range of frequency of the oscillations considered. 2. Under the imposed experimental conditions angular velocity appears to be the parameter of the movement which is predominantly sensed and fed back by the reflex loop. Data were also presented on the performance of the motor task by patients who underwent surgical ablations of the cerebellar cortex. Comparison of these results with those of normal subjects strongly supports the hypothesis that cerebellar-related activities are instrumental in determining the sensitivity of the stretch reflex to angular velocity.
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  • 138
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    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 139
    ISSN: 1432-0800
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    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary A study was made of the problems encountered when the chromatogram of a sample being analyzed for PCB's via GLC cannot readily be compared to a particular Aroclor standard. The use of mixed Aroclor standards was proposed and a study made of the effect of mixed standards on the analytical results. It was found that the choice of a standard could alter the values by more than a factor of 2. In addition, the particular mixture used as a standard should be reported along with resulting values.
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  • 140
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  • 141
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    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary An investigation was carried out to estimate the amount of lead extracted by storing acetic acid in 231 pieces of glazed earthenware pottery. The average concentration of lead was found to be 4.2 mg/litre and the range was 1.0 to 6.5 mg/litre. The amount of lead extracted increased sharply between 70° to 90°C. Hence storage of hot beverages in pottery for long periods may pose health hazards due to chronic lead toxicity.
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  • 142
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  • 143
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  • 144
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  • 145
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    Notes: Conclusions 1. The investigation was designed to elucidate the mechanism of migration of Aroclor 1242 to packaged foods. It was conducted in sealed glass jars and the packaging materials used had been treated to contain higher levels of Aroclor 1242 than are commonly found in food packaging materials presently used in the food industry. The data indicate that migration is a vapor-phase phenomenon. Accordingly, interposing barrier materials between Aroclor bearing paperboard and food significantly reduces the migration to food. The degree of the reductions appears inversely correlated with the known gas permeabilities for the classes of barrier materials studied. Of these, PVDC-coated paper prevented Aroclor migration for the 90-day test period. Waxed glassine paper was found to be second most effective of the barriers included in this study. Polyethylene film was relatively ineffective at the longer storage intervals. 2. In the absence of an effective barrier, Aroclor 1242 was shown to migrate from paperboard to food in measurable amounts when food is packaged in paperboard containing a significant amount of Aroclor 1242. 3. Pick-up of Aroclor 1242 by packaged foods is predominately an adsorption phenomenon. The equilibrium adsorption of Aroclor 1242 on food is primarily dependent on the surface area of the food and only secondarily dependent on the fat content of the food. This suggests that adsorption is a surface condensation mechanism. 4. The effectiveness of other barrier materials commonly used in food packaging, e.g., foil laminates, copolymer films, paper laminates was not investigated. The results of this study would suggest that materials of low gas permeability would be effective barriers to PCB migration.
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  • 146
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  • 147
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  • 148
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  • 149
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  • 150
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  • 151
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  • 152
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  • 153
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary The modes of inhibitory effects of 3 PCBs, KC-300,-400 and -500, on oxidative phosphorylation of respiring mitochondria were studied. It was found that the toxicity potency of the PCBs increases with lower chlorine content. The modes of inhibition of the 3 PCBs with regard to antagonism and toxicity, were found to be different according to their composition. KC-300 was only an energy transfer and electron transfer system inhibitor at all concentration levels in contrast with KC-400 and -500, which were energy transfer and electron transfer system inhibitors at low concentrations but had an uncoupling effect at higher concentrations. A slight difference in inhibitory effects between KC-400 and -500 was also observed.
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  • 154
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 155
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 156
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 157
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 158
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Cadmium compounds and other heavy metals usually inhibit enzymic and metabolic processes (Webb 1966). The inhibition of detoxication activity of liver microsomal enzymes would be particularly detrimental to an organism, because the toxicity of many other substances would be increased. In fact, it has recently been reported (Hadley and Miya 1972) that hexobarbital sleep time was prolonged after injection of rats with cadmium acetate. In contrast, the present report contains observations on stimulation of liver microsomal enzyme activity in rats fed cadmium acetate (CdAc) and the interaction of effects of CdAc with those of phenobarbital sodium (PB).
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  • 159
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 160
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 161
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Effects of insecticides upon both target and non-target organisms often reflect interaction with cellular membranes (Matsumura and O'Brien, 1966). For instance, in the case of vertebrates, these effects include inhibition of plasma membrane ATPase (adenosine triphosphatase) (Davis et al. 1972), increased metabolic transformations by microsomal membranes (Remmer et al. 1967), and disruption of osmotic equilibrium (Janicki and Kinter 1971). Since mitochondrial energy coupling is localized in the inner mitochondrial membrane and since coupling is highly sensitive to assault on the integrity of that membrane, we have undertaken to examine the action of insecticides on processes associated with mitochondrial energy conservation. The present communication presents data indicating that low concentrations of several chemically-unrelated insecticides stimulate mouse mitochondrial ATPase in a manner similar to that of uncouplers of oxidative ATP synthesis.
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  • 162
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary The present report from Texas confirms the Mississippi findings of insecticide resistance inGambusia. In addition, we report evidence that urban, as well as agricultural, uses of insecticide may result in resistantGambusia populations. Further, we observed a resistance pattern that is distinctly different from that found in Mississippi.
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  • 163
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 164
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary The effects of DDE on the function of the salt gland, the main route of sodium chloride excretion in marine birds, were investigated in mature mallards,Anas platyrhynchos, maintained on either fresh water or 1 percent salt water and given 0, 10, 100, or 1000 ppm DDE in the diet (12 birds per level). The rate of sodium chloride excretion by the salt gland following injections of concentrated salt solutions was not reduced (from that of controls) in DDE-treated birds maintained on salt water, but was significantly reduced in DDE-treated birds not previously given salt.
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  • 165
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    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 166
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary ‘Aroclor 1242’ (PCB) or DDT increased liver weight and lipids and decreased liver vitamin A of male and female rats or male Japanese quail. Laying female quail did not show consistent changes, presumably due to mobilization of lipid and vitamin A for egg yolk. When egg laying was inhibited, PCB reduced liver vitamin A 50%. ‘Aroclor 1242’ reduced egg production, but had no effect on egg weight or eggshell thickness.
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  • 167
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Summary Laying hens were fed a total of 18 mg of dieldrin over an 11-day period. Some of these were fed charcoal and others received phenobarbital during the 11-day period. Neither treatment affected the amount of dieldrin residue in the eggs. The maximum dieldrin residue in the eggs was about 4 ppm and occurred about 20 days after the initial dosage or about 9 days after cessation of dosage. The dieldrin residue levels in the livers ranged from 0 to 228 ppb and the brains contained no dieldrin residue. No change in shell thickness of the eggs or weights of the chickens was noted.
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  • 168
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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