Experiments on mitochondrial swelling in vivo

Riassunto E stato provato l'effetto sui mitocondri in vivo dei seguenti composti che producono rigonfiamento dei mitocondri isolati in vitro:l-cistina,l-cisteina, glutatione, L-ascorbato,l-tiroxina,l-3, 5, 3-triiodotironina, fosfato e Ca⁺⁺. Solo il Ca⁺⁺ ha provocato un aumento di volume dei mitocondri nelle cellule provate, i mioblasti coltivati in vitro.     

The effect of hydrocortisone and thyroxine on development of calcium homeostasis in embryonic intestinal epithelium

Cytoplasmic Ca²⁺ concentration of epithelial cells from 14-day embryonic chick duodena decreased during 72 h of organ culture to a value 54% of that found at 17 days in vivo. The ability of cells to maintain a constant Ca²⁺ concentration when challenged with high extracellular calcium was also significantly reduced. Addition of 1 M hydrocortisone during culture restored both parameters of Ca²⁺ homeostasis to that of 16-day uncultured duodena, and rise in cytoplasmic Ca²⁺ was significant within 4 h of hormone treatment. Thyroxine influenced epithelial Ca²⁺ similarly, but to a lesser degree and only after 48–72 h of culture. These data indicate that glucocorticoids, and possibly thyroid hormones, influence the development of calcium homeostasis in intestinal epithelium.     

Limitations of the ‘direct linear plot’ in evaluation of drug-protein binding parameters

Summary The applicability of the direct linear plot is compared with that of the Scatchard plot for the estimation of protein binding parameters. Only, if one class of binding sites exists in the system tested, binding parameters may be estimated by use of the direct linear plot. On the other hand the Scatchard plot also provides estimates in systems with more that one class of binding sites.     

Chromosomes and some issues of the evolution of the ground squirrel genusCitellus (Rodentia: Sciuridae)

Citellus (s. str.) relictus, C. dauricus C. pygmaeus (2=36, NF=72). . (Colobotis) erythrogenys . fulvus -. . (Urocitellus) undulatus (2n=32, NF=64) . columbianus. Citellus, , Citellus, . , .     

Transfer of cantharidin (1) during copulation from the adult male to the femaleLytta vesicatoria (‘Spanish flies’)

Summary Adult males of the spanish flyLytta vesicatoria (Meloidae, Coleoptera) are able to biosynthesize cantharidin (1) in copula after injection of E, E-11-(³H,¹⁴C)-farnesol and 2-¹⁴C-methylfarnesoate. During mating, the cantharidin biosynthesized in the males is transferred to the females, who are unable to biosynthesize cantharidin from any terpenoid precursors. After injection of (³H,¹⁴C)-cantharidin into males during copulation, more than 10% is transferred into the female sex organs. Males injected with 2-(³H,¹⁴C)-mevalonate 24–30 h prior to copulation transferred 93–98% of the biosynthesized cantharidin to the females during mating. After mating, the males continue to produce cantharidin. It seems that in the male the biosynthesis of cantharidin is stimulated during copulation.III. Communication on the Biosynthesis of Cantharidin; II. Communication¹⁶.Dedicated to ProfessorKurt Mothes' (Halle/Saale, DDR) 75th birthday, 4.11.1975. J. R. Sierra, Thesis in preparation University Zürich. J. R. S. thanks the Eidgenössischen Stipendienkommission für ausländische Studierende for a fellowship.Research supported by the Schweizerische Nationalfonds.     

An unwelcome discovery: The pole effect in the electric arc, a threat to early 20th century precision spectrometry

In late 1912, Fritz Goos at the Hamburg Physikalisches Staatslaboratorium discovered a systematic dependency of arc-spectra wavelengths on the length of the electric arc used and on its electric parameters, such as, for instance, the current employed. In early 1913, at Heinrich Kayser's better-equipped physical laboratory in Bonn, Goos was able to confirm these effects using a large concave Rowland grating. He was able to establish that variations of between 3 mm and 10 mm in the length of the arc produced wavelength differences of up to 0.02 Å violet shift and -0.007 Å redshift respectively. Further inquiry also revealed a dependency of the wavelength on the region of the arc selected for spectrometric observation. All these surprising effects were soon collectively named pole effect.As is shown in this paper, the pole effect threatened the validity of the results of the entire research tradition of high-precision spectroscopy which, around 1910, had excelled in establishing several internally coherent systems of wavelength assignments. These wavelength catalogues had been established by spectroscopists such as Heinrich Kayser, Paul Eversheim and their co-workers in Bonn, by August Herman Pfund in Baltimore, and by Charles Fabry and Henri Buisson in Marseille under the aegis of the International Union for Co-Operation in Solar Research. They had all produced locally consistent, homogeneous systems of wavelengths with estimated errors sometimes smaller than 0.001 Å. However, long before 1913, strange non-local inconsistencies had emerged between these systems that were of much greater magnitude than the estimated error. The discovery of the pole effect opened up the possibility that variations in the arc parameters used in the measurements, which the different teams had hitherto not specified, were responsible for the systematic differences, in their respective sets of measurements, coming to up to 0.025 Å.This paper explores the interrelations between local knowledge production, the strategies for the establishment of local coherence, and the ways in which the community of physicists and spectroscopists handled a possible threat to this coherence after 1913. Around 1930, a general agreement was reached about the physical cause of the pole effect, namely Stark effects, caused in turn by intermolecular electric fields of ions in the arc. Much before 1930, however, the community had already succeeded in standardizing the instrumentation used in high-precision spectrometry and had conformed its research practice to such an extent that from 1917 on the pole effect could be routinely circumvented in high-precision spectrometry and interferometry. Thus, experimentation along with its instrumentation, indeed had a life of its own, independent of the many unsuccessful efforts to explain the pole effect theoretically.     

An analysis of the effects of urethane on cardiovascular responsiveness to catecholamines in terms of its interference with Ca++ mobilization from both intra and extracellular pools

Summary Urethane (1×10^–2–1×10^–1 M) reduced, in a concentration-dependent manner, both intra and extracellular Ca⁺⁺ dependent noradrenaline-induced contractions of perfused rabbit ear artery as well as the tonic contractions produced by perfusion with high K⁺ solution. However, a quantitative analysis of the data indicated that for urethane concentrations similar to those found in plasma during anesthesia urethane antagonism is confined to noradrenaline-induced contractions which depend upon the mobilization of Ca⁺⁺ from intracellular storage sites. In KCl-contracted arteries, urethane enhanced the relaxant effects of isoprenaline.—Urethane reduced the amplitude of contractions of spontaneously beating guinea-pig right atrium at concentrations which have only a limited effect on frequency. In addition, it decreased in a concentration-dependent manner the amplitude of isoprenaline-activated electrically driven, and K⁺ depolarized guinea-pig right ventricular strips. Urethane had no effect on the chrono and inotropic actions of isoprenaline on cardiac preparations. In in vivo experiments the chronotropic response to low doses of isoprenaline was significantly higher in urethane-treated as compared to unanesthetized rats. The higher dose of isoprenaline tested produced a significant fall in systolic blood pressure in urethane-anesthetized rats. A significant correlation exists between the chronotropic response to isoprenaline and resting heart rate values in urethane-anesthetized rats. These results indicate that urethane, at concentrations similar to those found in plasma during anesthesia selectively interferes with mobilization of Ca⁺⁺ from intracellular storage sites. In addition, the interference of urethane anesthesia with the isoprenaline chronotropic effect in vivo cannot be explained by a direct interference of urethane with -adrenoceptors at cardiac level.     

Effects of prostaglandin E1 on45Ca++-incorporation and spike activity in longitudinal smooth muscle of cat jejunum

Summary Prostaglandin E₁ (0.3 M) decreased both the⁴⁵Ca⁺⁺-incorporation and the spike activity in isolated longitudinal smooth muscle preparations of the cat jejunum probably by an inhibition on the Ca⁺⁺ influx.     

Isoprenaline-like effects of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine on mechanical,biochemical and electrophysiological parameters in the mammalian heart

Summary The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) mimicked the effects of isoprenaline on the force of contraction, the cAMP content and the slow Ca⁺⁺ inward current (I_si) in isolated guinea pig papillary muscles. The results support the hypothesis that phosphodiesterase inhibitors and -adrenoceptor agonists exert their positive inotropic effects by increasing I_si via the common mediator cAMP.Acknowledgment. This work was supported by the Deutsche Forschungsgemeinschaft.     

Ein neues Verfahren zur Herstellung von 19-Norsteroiden

Summary The new methods for the production of 19-norsteroids described involve the conversion of 5-halogen-6-hydroxy-steroids into the corresponding 5-halogen-6:19-ethers either with lead tetraacetate or by the hypoiodite reaction^8,10. The 6:19-oxygen bridge is then opened reductively either directly or after oxidation of the 6:19-ethers to lactones or preferably after introduction of a ^4,6-3-oxo grouping. Acylolytic cleavage of the ⁴-3-oxo-6:19-ethers followed by alkaline hydrolysis gives ^4,6-3-oxo-19-hydroxy-steroids. The 19-hydroxycompounds formed are easily converted into 19-norsteroids by known methods.

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Über Steroide, 189. (vorläufige) Mitteilung; 188. Mitt. vgl.J. Kalvoda, J. Schmidlin, G. Anner undA. Wettstein, Exper.18, 398 (1962).     

Effect ofd,l-glyceraldehyde on bacterial cells metabolism

Riassunto In aerobiosi lad-l-gliceraldeide a notevoli concentrazioni ha una lievissima azione inibente sulla ossidazione del glucosio e sulla incorporazione di leucina-C¹⁴. In condizioni di anaerobiosi invece lad-l-gliceraldeide in concentrazioni medie inibisce notevolmente sia la glicolisi che la incorporazione di leucina-C¹⁴.

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This work was carried out with the help of Consiglio Nazionale delle Ricerche (CNR).     

Geminus and the concept of mean motion in Greco-Latin astronomy

Conclusion Geminus account of lunar motion in chapter 18 of hisIntroductio astronomiae is, in our view, an important contribution to Greco-Latin astronomy because, in attempting to reconstruct arithmetically (the parameters of) the Moon's motion in longitude, he undermines the task astronomers had hitherto set for themselves. This undermining of a commonly acknowledged view of the purpose of astronomy is articulated in a whole new set of questions concerning the nature and place of both observation and mathematical reasoning in the science of the heavens. Yet, one must not overlook the fact thatGeminus reconstruction also indicates resources for addressing these questions. Of these resources, the most powerful proved to be the idea that irregular motion could be quantified as a systematic departure from a mean motion, and the idea that observational data could be organized and structured by means of genetic arithmetical reconstructions.But, since we limit our attention to extant treatises and decline to speculate about works or parts of works that have not survived, we must say that it would takePtolemy to discern the new direction for astronomy thatGeminus opened up and to pursue it. In part, this involved straightening out the conflated conception of mean motion in chapter 18 — the qua arithmetic mean daily displacement can only be anapparent lunar motion in longitude and not one the Moonreally makes, but the same need not be true of the qua periodic mean daily displacement — and determining its proper relation to real and apparent planetary motion. Indeed,Ptolemy's genius lay, we think, in seeing that even though, in assimilating Babylonian astronomy, earlier and contemporary Greco-Latin writers betrayed a confused, inconsistent, and unsophisticated grasp of the proper role of arithmetic, geometry, and observation in astronomical argument [seeBowen 1994], the solution lay in a mathematical reconstruction of the observed celestial motions, in which mean motion played an essential role.     

Über «therapeutische» und «toxische» Digitoxigeninwirkungen auf elektrophysiologische Messgrössen des Meerschweinchenvorhofs

Summary Therapeutic concentrations of digitoxigenin (10^–7–3× 10^–7 g/ml), producing positive inotropic effects, did not alter resting and action potentials of electrically driven guinea-pig auricles. However, toxic concentrations of digitoxigenin (5 × 10^–7–10^–8 g/ml), producing arrhythmias and contracture of the myocardium, had a marked influence upon resting and action potentials and conduction velocity.     

Cardenolide glycosides from the adults and eggs ofChrysolina fuliginosa (Coleoptera: Chrysomelidae)

Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by¹H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.     

Synthesis of 3-(2′-chloroethoxy)-6-formyl-Δ3,5-pregnadienes. A new class of highly active anti-inflammatory corticosteroids

Riassunto È stata studiata 1'azione del reattivo di Vilsmeier-Haack su 3-cicloetilendiossi- ⁵-steroidi appartenenti ai corticoidi; è stata così ottenuta una scrie di 3-(2-cloroetossi)-6-formil- ^3,5-pregnadieni, alcuni dei quali hanno mostrato notevoli proprietà antiinfiammatorie con una netta dissociazione dell'attività per somministrazione locale e somministrazione sistemica.     

Effect of X-537A on the phosphorylated protein in sarcoplasmic reticulum vesicles

Summary The effect of the antibiotic X-537A on the phosphorylated ATPase (EP) was investigated. The results show that X-537A depresses the level of EP which is dependent on the Ca²⁺ gradient, while the Ca²⁺-independent EP is not affected. Acknowledgments. This work was supported by grants from the Instituto de Alta Cultura of the Portuguese Ministry of Education (No. CB/2) and the Calouste Gulbenkian Foundation.     

On the stability of cognitive processes

Summary An empirical and mathematical model for self-organization is proposed, based on elemental properties, on unique interaction and on the combination of hierarchical elements. In the model, higher elements are stabilized by the cognitive (strong) interaction of subelements, disregarding intermediate elements. This is called elementary reductionism and is illustrated by the sequence quarks-elementary particles-atoms-molecules-cells-organisms-societies. Optimal dynamic interaction of nonidentical elements is called cognitive stability. This is compared with thermodynamic equilibrium. The principal differences are outlined.     

Total synthesis of the antibiotic polymyxin B1

Zusammenfassung Es wird über die Synthese des cyclo-Decapeptides 7, in welchem alle Dab-Reste diel-Konfiguration aufweisen, berichtet. Dieses erwies sich als identisch mit natürlichem Polymyxin B₁ (Figur 2).     

On the structure of the natural dipeptide N-acetyl-aspartyl-glutamic acid (NAAGA)

Riassunto Si descrive la sintesi dei due dipeptidi isomeri acido N-acetil--l-aspartil-l-glutammico (I) e acido N-acetil--l-aspartil-l-glutammico (II). Il loro confronto con il NAAGA, dipeptide precedentemente isolato dal tessuto nervoso di alcuni mammiferi, ha dimostrato l'identità del nuovo metabolita con il-dipeptide (II).     

Interdependence between locomotor activity and duration of wakefulness in humans during isolation

Summary Locomotor activity was recorded in 14 subjects who lived singly in an isolation unit for 16 to 88 days. Their free-running circadian rhythms had a mean period of 25.9 h, with individual means in the duration of wakefulness () ranging from 12.1 to 22.9 h. Intraindividually, the hourly means of activity were negatively correlated with to such a degree that the total amount of activity per day remained constant irrespective of large variations in .