Showing papers by "Heidelberg University published in 1968"

Early Changes in Energy Metabolism in the Myocardium Following Acute Coronary Artery Occlusion in Anesthetized Dogs

Abstract: The tissue content of energy-rich phosphates and glycolytic metabolites and the activity of myocardial enzymes were examined in the dog after producing myocardial infarction by ligating branches of the anterior descending and circumflex coronary arteries. The pattern of systolic fiber movement shown by a strain-gauge assembly differentiated ischemic from nonischemic portions of myocardium. In ischemic muscle, 30 minutes after onset of ischemia, creatine phosphate content fell from 8.0 to 1.4 µmoles/g, ATP content fell from 5.8 to 1.5 µmoles/g, lactate content rose tenfold, and α-glycerophosphate content rose fivefold. The content of energy-rich phosphates and glycolytic metabolites did not change much in nonischemic muscle. The activities of myocardial enzymes were assayed in extracts of tissue samples from ischemic and nonischemic muscle 5 to 120 minutes after coronary artery occlusion. The activities of aldolase, lactic dehydrogenase (LDH), glyceraldehydephosphate dehydrogenase, α-glycerophosphate dehydrogenase, malate dehydrogenase (MDH), and 6-phosphogluconate dehydrogenase did not change significantly in ischemic muscle during 2 hours of observation. In nonischemic muscle, phosphofructokinase activity increased 75% 5 minutes after coronary occlusion, followed by an increase in activity of isocitrate dehydrogenase, creatinephosphokinase, MDH, and LDH. The enzymatic changes in nonischemic muscle suggest metabolic changes in nonischemic muscle accompanying compensatory hyperfunction and increased energy requirements of surviving muscle.

STUDY OF THE $lambda$--N SYSTEM IN LOW-ENERGY $lambda$--p ELASTIC SCATTERING.

Abstract: The present paper is based on 378 $\ensuremath{\Lambda}\ensuremath{-}p$ elastic scattering events in the incident-momentum region 120-320 $\frac{\mathrm{MeV}}{c}$. Differential and total cross sections have been measured in several momentum intervals and found to be consistent with predominantly $S$-wave scattering. No significant indication for the existence of a low-energy $\ensuremath{\Lambda}\ensuremath{-}p$ resonance has been found. Using the effective-range approximation, the four scattering parameters ${a}_{s}$, ${a}_{t}$, ${r}_{s}$, and ${r}_{t}$ were evaluated with and without further assumptions on the $\ensuremath{\Lambda}\ensuremath{-}p$ interaction properties. Best values obtained from the four-parameter fit were ${a}_{s}=\ensuremath{-}1.8$, ${a}_{t}=\ensuremath{-}1.6$, ${r}_{s}=2.8$, and ${r}_{t}=3.3$ F. A likelihood-function mapping procedure is used to describe the large and strongly correlated errors of these values.

The effect of the duration of the action potential on contraction in the mammalian heart muscle

Abstract: A method is described to control the membrane potential in preparations of mammalian myocardium, and to measure tension simultaneously. The following observations are made: A discussion of the relationship between the action potential and contraction in cardiac muscle is included.

Single unit responses and the total afferent outflow from the cat's foot pad upon mechanical stimulation.

Abstract: The properties of mechanosensitive units with large myelinated afferents were determined in the hairless skin of the central pad of the cat's hind foot, and the total afferent outflow from this region after short skin indentations and during constant force stimuli was measured in the plantar nerves.

Einfache Methode für die Auswertung von Messungen der Transportphänomene

Abstract: Die Darstellung des Diffusionskoeffizienten D nach der Theorie von Hirschfelder et al. [1] macht es erforderlich, die beiden Parameter des Lennard-Jones-(6; 12)-Potentials, ϵ12/k und σ12, geeignet so zu bestimmen, das die damit berechneten Diffusionskoeffizienten mit den gemessenen bei allen Temperaturen Ti ubereinstimmen. Die in der Literatur [2, 3] genannten Methoden laufen auf ein sehr aufwendiges, bei vernunftigem Zeitaufwand nur von einem Computer losbares Minimalisierungsverfahren hinaus. Die hier beschriebene Methode, deren wir uns bei der Auswertung unserer an Gasen in einem groseren Temperaturbereich vorgenommenen Diffusionsversuche bedienten, erlaubt ein einfaches und schnelles Auffinden der Parameter der Potentialkurve aus den Mesergebnissen. The representation of the diffusion coefficient D according to the theory of Hirschfelder et al. [1] makes it necessary to determine both the parameters of the Lennard-Jones-(6; 12)-potential, ϵ12/k and σ12, in such a way, that the diffusion coefficients calculated using them agree with the measured values at all temperatures Ti. The methods quoted in the literature demand a very elaborate minimisation procedure, which, within a reasonable period of time, is only possible by computer. The method described here, which we have used in evaluating our diffusion experiments on gases over a wide range of temperature, permits a simple and rapid derivation of the parameters of the potential curve from the measurements.

Dorsal root potentials after C-fiber stimulation.

Abstract: A pure volley from C-fibers, set up by electrical stimulation of a cutaneous nerve and subsequent selective blocking of the A-fibers, generates in the cat spinal cord a dorsal root potential (C-DRP). Its polarity is the same as that of the dorsal root potential elicited by stimulation of the A-fibers (A-DRP), thus probably providing presynaptic inhibition of primary afferents. The size of the C-DRP increases in proportion to the size of the C-volley. A preceding A-DRP reduces the C-DRP.

Mineralogy, Petrology and Chemical Composition of Some Calcareous Tufa from the Schwäbische Alb, Germany

Abstract: Calcareous tufas from the Schwabische Alb collected and studied botanically by A. Stirn are investigated mineralogically, petrographically, and chemically.

On the utilization of erythrocyte acid phosphatase polymorphism in paternity evaluation

Abstract: Es wird uber Erfahrungen mit dem System der sauren Erythrocytenphosphatase in der Vaterschaftsbegutachtung berichtet. Im Anschlus daran wird die Frage untersucht, ob dem System bereits voller Beweiswert zuerkannt werden kann, wobei zunachst ganz allgemein auf zwei verschiedene Auffassungen eingegangen wird, daruber, welchen Umfang das Familienmaterial haben mus, das in einem serologischen System als frei von Abweichungen von dem fur das System postulierten Erbgang befunden wurde, damit dem System ein bestimmter Beweiswert hinsichtlich eines Vaterschaftsausschlusses zukommt. DieY/X-Werte des Essen-Moller-Verfahrens werden fur das System der sauren Erythrocytenphosphatase nach den von den Autoren in Sudwestdeutschland ermittelten Genfrequenz tabelliert. Im Anhang werden fur einen beliebigen autosomalen Locus mit zwei oder mehr Allelen ohne Dominanz Formeln fur die Wahrscheinlichkeit eines Vaterschaftsausschlusses abgeleitet und das allgemeine Rechenverfahren zur Ermittlung derY/X-Werte des Essen-Moller-Verfahrens angegeben.

Influence of insulin on cyclic 3',5'-AMP phosphodiesterase activity in liver, skeletal muscle, adipose tissue, and kidney.

Abstract: Influence of insulin on liver glycogen metabolism and on lipolysis appears to be mediated by a decreased intracellular 3′,5′-AMP concentration. Reduced formation of 3′,5′-AMP had been shown in adipose tissue incubated with insulin. The influence of insulin on 3′,5′-AMP degradation has been investigated. — 3′,5′-AMP phosphodiesterase (PDE) activity was reduced in liver, adipose tissue and, insignificantly, in skeletal muscle of insulin deficient, i.e. alloxan diabetic or starved rats. I.V. injection of a low dose of insulin (0.5 U/kg) or stimulation of endogenous insulin secretion by injection of glucose led to a rapid increase of PDE activity in these tissues. 15 min after insulin injection liver PDE activity was increased. The maximal effect occurred after 30–45 min. Renal PDE activity was not decreased in alloxan diabetes, insulin injection has been found ineffective. —In vitro, there was an activating effect of crystalline insulin on PDE purified from beef heart. Insulin concentration required for duplication of enzyme activity was of the order of 2 · 10−5 M. Treatment with actinomycin D nearly prevented stimulation of liver PDE by insulin. This may indicate that the action of insulin on PDE activity is essentially based on an increased enzyme synthesis. — Owing to the influence of insulin secretion on liver and adipose tissue 3′,5′-AMP concentration, glycogen metabolism and lipolysis can be quickly adapted to food intake.

Two specific feedback pathways to the central afferent terminals of phasic and tonic mechanoreceptors.

Abstract: In five types of mechanoreceptor afferents of the cat's hind foot, the primary afferent depolarization (PAD) induced by mechanical skin stimulation was measured by testing the excitability of their terminations in the dorsal horn. Two types of skin stimuli were used to set up activity in distinct populations of rapidly and slowly adapting mechanoreceptors respectively.

Über die Fermi-Resonanz bei der Wasserstoffbrückenassoziation primärer aliphatischer Amine: (nach Ultrarotuntersuchungen an 2.2.2-Trifluoräthylamin)†

Abstract: Die Ergebnisse einer vorausgegangenen Ultrarotuntersuchung, bei der die Mischassoziation primarer aliphatischer Amine mit tertiaren Aminen unterschiedlicher Basizitat unter der Verwendung von 2.2.2-Trifluorathylamin als primarem Amin verfolgt wurde, werden eingehende): gedeutet: Aus dem Intensitatsverhaltnis der beiden im Gebiet der symmetrischen NH-Valenzschwingung beobachteten Assoziatbanden, die als Fermi-Resonanzpaar aus der symmetrischen Grundschwingung und dem Oberton der Deformationsschwingung erklart wurden, wird die Lage der ungestorten Schwingungen berechnet. Das Ergebnis der Rechnung bestatigt die Annahme, das die ungestorte symmetrische Schwingung zunachst eine hohere Wellenzahl als der ungestorte Oberton besitzt, aber mit wachsender Akzeptorbasizitat uber ihn hinwegwandert und schlieslich bei kleinerer Wellenzahl liegt. Mit den Frequenzgleichungen fur unsymmetrische gewinkelte Dreimassensysteme bei Bestehen einer Unsymmetrie nur in den Valenzkraftkonstanten werden die Anderungen der Aminogruppenschwingungen bei der Assoziation berechnet. Hierbei ergibt sich eine befriedigende Ubereinstimmung mit der Beobachtung erst, wenn die Fermi-Resonanz dadurch berucksichtigt wird, das die errechnete symmetrische und die fur den ungestorten Oberton angenommene Schwingung einer Storungsrechnung unterworfen werden. Der Fermi-Resonanz wird weiterhin dadurch Rechnung getragen, das der Ermittlung der Assoziationsenergie aus der Temperaturabhangigkeit der Assoziatbande die integrierten Absorptionsintensitaten der beiden Fermi-Resonanzbanden zusammengenommen zugrunde gelegt werden. Das Verfahren liefert eine Assoziationsenergie, die mit dem Wechsel der Basizitat des Akzeptors nur zwischen 2200 und 2600 cal/mol variiert. Die geringe Anderung last sich darauf zuruckfuhren, das mit Ansteigen der Akzeptorbasizitat nicht nur die Mischassoziationsenergie zunimmt, sondern auch die von ihr abzuziehende Komplexbildungsenergie des tertiaren Amins und des als Losungsmittel verwandten Tetrachlorkohlenstoffs. The results of an earlier infrared investigation in which the mixed association of primary aliphatic amines with tertiary amines of different basicity was studied using 2,2,2-trifluoroethylamine as the primary amine, are interpreted in more detail: From the intensity ratio of the two associate bands observed in the region of the symmetrical NH-valence vibration which were interpreted as a Fermi-resonance pair formed from the symmetrical fundamental vibration and the overtone of the deformation vibration, the position of the unperturbed vibrations is calculated. The result of the calculation confirms the assumption that the unperturbed symmetrical vibration at first possesses a higher wave number than the unperturbed overtone, but with increasing acceptor basicity it is shifted and finally has a lower wave number. Using the frequency equations for unsymmetrical non-linear three-mass-systems with dissymmetry only in the stretching force constant, the changes in the amino-group vibrations when association occurs are calculated. In this way satisfactory agreement with observation is obtained if the Fermi-resonance is considered in such a way that the calculated symmetric vibration and the vibration assumed for the unperturbed overtone are treated by a perturbation calculation. Fermi-resonance is also taken into account in that the derivation of the association energy from the temperature-dependence of the associate bands is based upon the integrated absorption intensities of both Fermi-resonance bands taken together. The procedure gives an association energy which varies with change in the basicity of the acceptor only between 2200 and 2600 cal/mole. The reason for the small change is that increasing acceptor basicity increases not only the energy of mixed association but also the energy of complex formation of the tertiary amine and solvent carbon tetrachloride which has to be subtracted from it.

a membrane current related to the plateau of the action potential of purkinje fibers

Abstract: The membrane potential of cardiac Purkinje fibers was changed by a voltage clamp technique and the membrane current was measured. It was shown that a depolarizing step triggers the flow of a component of membrane current which rises within 20 ms to a maximum and declines thereafter within 50 ms. This component of membrane current is positive at membrane potentials positive to −30 mV, it is negative at potentials negative to −30 mV. Following a depolarizing pulse 700–1000 ms have to pass before a second depolarizing step elicits the full amplitude of the current component. Substitution of extracellular chloride by propionate reduces the amplitude of the current component, substitution by nitrate has the opposite effect. Sodium removal from the extracellular solution decreases the current component between resting potential and −30 mV whereas a Ca-free solution has depressant effects in the whole potential range. Changes of the extracellular ionic concentration did not change the membrane potential at which the current changes from positive to negative. Tentative explanations of the nature of this component are given in the discussion.

Effects of glucocorticoids and insulin on 3',5'-AMP phosphodiesterase activity in adrenalectomized rats.

Abstract: Glucocorticoids stimulate the rate of lipolysis which is reduced in adrenalectomized animals. This hormonal action is antagonized by insulin. The antilipolytic action of insulin appears to be mediated by a reduced intracellular concentration of 3′,5′-AMP. This reduction can partly be attributed to an insulin-induced acceleration of 3′,5′-AMP degradation. — It is shown that the stimulatory influence of glucocorticoids on lipolysis is due to a reduction of 3′,5′-AMP phosphodiesterase (PDE) activity, which is increased by adrenalectomy. PDE activity was also increased in liver, skeletal muscle and kidney of adrenalectomized rats; treatment with a glucoeorticoid prevented this increase.In vitro, PDE purified from beef heart was inhibited by glucocorticoids in high concentrations (Ki=1.1 · 10−3 M for 6 α-methylprednisolone hemisuccinate,K i=1.6 · 10−3 M for prednisolone succinate).In vivo, the glucocorticoid-induced decrease of PDE activity (with retarded onset as shown in liver), may essentially be attributed to a decreased enzyme synthesis. — Studies on the interaction of insulin and glucocorticoids on PDE activity were performed in the liver. In adrenalectomized, alloxan diabetic rats insulin stimulated PDE activity suppressed by treatment with a glucoeorticoid, unsuppressed PDE activity was not increased by insulin. In contrast, the action of glucocorticoids on PDE activity was independent of the presence or the effectiveness of insulin.

General Relationship between Suspended Sediment Concentration and Water Discharge in the Alpenrhein and some other Rivers

Abstract: IN order to make a long-term prediction of sedimentation in Lake Constance (Central Europe), about five hundred measurements of the suspended load in the Rhine (“Alpenrhein”) at Lustenau, Austria (Fig. 1), have been carried out1,2 at different water levels.

Halbeinfache Gruppenschemata über vollständigen Kurven.

Abstract: Diese Arbeit entstand aus einem Versuch, die folgende Vermutung zu beweisen: Sei K ein eindimensionaler Funktionenk6rper fiber einem endlichen Konstantenk6rper Fq. Sei G/K eine halbeinfache, einfach zusammenh~ingende algebraische Gruppe. Dann ist H 1 (K, G)= 0. (Siehe z.B. [15], Chap. II, w 3.) Es ist miI bislang nicht gelungen, diese Vermutung zu beweisen. In dieser Arbeit wird zunachst eine ganz andere Frage untersucht. Sei k ein K/Srper, sei Y/k eine glatte, projektive Kurve tiber k (s. [-9], Chap. IV, 6.8). Sei K/k der Funktionenk6rper der Kurve Y/k. Wir wollen in dieser Arbeit halbeinfache Gruppenschemata G/Y, die lokal beziJglich der Zariskitopologie zerfallen, studieren. (Siehe E6], w 3 und [13], 1.1.) Wir wollen solche Gruppenschemata rational trivial nennen; denn es sind genau diejenigen, ftir die GK=G • K ein Chevalleyschema ist (s. [13], w 3). Die ersten beiden Paragraphen dieser Arbeit sind dem systematischen Studium der Boreluntergruppen rational trivialer Gruppenschemata gewidmet. Jeder Boreluntergruppe B eines rational trivialen Gruppenschemas G/Y werden wir ein r-Tupel ganzer Zahlen nx(B)...n,(B ) zuordnen, wobei r der Rang yon G/Y ist. Diese Zahlen ni(B ) sind wie folgt definiert. Sei n = {~1... ~,} die Menge der einfachen Wurzeln von B, jeder dieser einfachen Wurzeln ist ein inversibler (gy-Modul U,, zugeordnet, und dessen Grad c(0~,) ist ni(B ). (Siehe 1.i und 2.1.) Als Hauptergebnisse dieser Arbeit sind nun der Satz 2.2.6, der Satz 2.2.13 und das Korollar 2.2.14 anzusehen. Der Satz 2.2.6 besagt: Sei g das Geschlecht der Kurve Y/k, sei h > 0 die kleinste Zahl, so dab es einen inversiblen d~r-Modul vom Grad h tiber Y gibt, dann gibt es stets eine Boreluntergruppe B in G/Y, so dab n i (B)> 2 g 2 ( h 1). Wir werden eine Boreluntergruppe, deren Invarianten ni(B ) der obigen Ungleichung geniigen, reduziert nennen. Der Satz2.2.13 besagt: Sind fiir eine reduzierte Boreluntergruppe B einige der Invarianten nil(B)...nis(B) ,,sehr grofl", so sind ffir jede reduzierte Boreluntergruppe B Ivon G/Y die gleichen Invarianten n~(BO... nis(B1) auch ,,sehr groB". Sei unter den gleichen Voraussetzungen P = B

Mutagenicity tests in mice. I. The dominant lethal method and the control problem.

Abstract: The dominant lethal method has been described and the control data of C3H inbred mice and (101xC3H)F1 hybrids were analysed. It could be demonstrated that infectious diseases and the number of implantations per uterus can influence the embryonic mortality. Other tested parameters such as 0.9% NaCl solution, aqua dest., and paternal and maternal age have within a certain frame no effect on the embryonic mortality. The heterogeneity does not permit a pooling of the controls and suggests on the other hand that each experiment should have a sufficient number of own controls to enable a decision over the mutagenicity of a compound.

Zur Evolution der Carabiden-Wehrdrüsensekrete

Abstract: bis fast zum Gefrierpunkt abgektihlt. Bis hinab zu wenigen Graden tiber Null lief der Motor noch an. Auch an einem lebenden narkotisierten Tier liel3 sich der Versuch ausftihren: In der H6he der oberen GliedmaBen wurde ein Einschnitt in die Haut vorgenommen und eine ca. t cm breite Plattenelektrode eingeftihrt sowie etwas Ringerl6sung eingebracht. Der Frosch taucht in ein Becherglas mit Ringerl6sung; eine Gegenelektrode ist an der Glaswand befestigt (s. Fig. 5). Nun ist ein M i k r o w a t t = l , 0 2 t 0 -2 Epond crn sec-1], als Leistung in mechanischen Gr6gen also ~iquivalent dem Heben eines t/ t0-Grammgewiehts um I mm pro sec. Somit sollte es aueh m6glich sein, ein isoliertes Hautsttick mechanische Arbeit verrichten zu lassen. Ein leiehtes Plexiglasgewinde| wurde als Aufsatz auf die Motoraehse gesetzt und daran mit einem Faden tiber eine Umlenkrolle ein Gewicht befestigt. Es zeigte sieh, daft Gewiehte von einigen Zehntelgramm in t bis 2 rain urn t c m emporgezogen wurden. 6 em 2 Hautfliiehe wiegen etwa 0,4 g. Die Leistungsabgabe ist also ausreichend, dab die Haut ihr Eigengewieht in wenigen Minuten um I em heben kann eine augenf~illige Demonstration der ,,elektromotorischen Kraf t\" eines biologischen ,,t3rennstoffElements\".

Selective activation of C-fibers

Abstract: A polarizing current applied transiently to a nerve selectively blocks conduction in the A-fibers, whereas the C-fibers remain unaffected The block is reversible Stimulation of A-fibers by the polarizing current is prevented by appropriately adjusting its slope of rise