Effect of medium on transplantability of nuclei ofBufo arenarum embryonic cells

Resumen Se transplantaron núcleos de blástulas deBufo arenarum en ovocitos enucleados de la misma especie operando en las soluciones salinas deBarth y deNiu yTwitty. Con la solución deBarth se consiguió un porcentaje más alto de huevos con segmentación normal que el obtenido con la solución deNiu yTwitty. La proporción final de renacuajos normales obtenidos, sin embargo, resultó idéntica en ambas series de experimentos.

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This work was partially supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina.     

The ascendancy of the Laplace transform and how it came about

The modern Laplace transform is relatively recent. It was first used by Bateman in 1910, explored and codified by Doetsch in the 1920s and was first the subject of a textbook as late as 1937. In the 1920s and 1930s it was seen as a topic of front-line research; the applications that call upon it today were then treated by an older technique — the Heaviside operational calculus. This, however, was rapidly displaced by the Laplace transform and by 1950 the exchange was virtually complete. No other recent development in mathematics has achieved such ready popularisation and acceptance among the users of mathematics and the designers of undergraduate curricula. Communicated by C. Truesdell     

Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in human Ascaris lumbricoides.

The phospholipid level in the human parasitic nematode Ascaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.     

Foraging behaviour patterns of herring gulls elicited by electrical forebrain stimulation

Zusammenfassung Zwei artspezitische Verhaltensabläufe, die Silbermöwen (Larus argentatus) bei der Futtersuche und Futteraufnahme zeigen, wurden durch elektrische Reizung begrenzter Bezirke des rostralen Vorderhirns experimentell hervorgerufen. Diese Befunde stützen vergleichend-anatomische Schlussfolgerungen über die funktionelle Rolle des rostralen Vorderhirns bei Vögeln.

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The work was supported by grants from the United States Air Force, the Science Research Council and the Royal Society to ProfessorN. Tinbergen and myself. It was partially carried out at the Department of Zoology, Oxford. The assistance of Dr.G. Thompson and Mr.A. Jackson is gratefully acknowledged.     

Metabolism of the neuromodulator d-serine

Over the past years, accumulating evidence has indicated that d-serine is the endogenous ligand for the glycine-modulatory binding site on the NR1 subunit of N-methyl-d-aspartate receptors in various brain areas. d-Serine is synthesized in glial cells and neurons by the pyridoxal-5′ phosphate-dependent enzyme serine racemase, and it is released upon activation of glutamate receptors. The cellular concentration of this novel messenger is regulated by both serine racemase isomerization and elimination reactions, as well as by its selective degradation catalyzed by the flavin adenine dinucleotide-containing flavoenzyme d-amino acid oxidase. Here, we present an overview of the current knowledge of the metabolism of d-serine in human brain at the molecular and cellular levels, with a specific emphasis on the brain localization and regulatory pathways of d-serine, serine racemase, and d-amino acid oxidase. Furthermore, we discuss how d-serine is involved with specific pathological conditions related to N-methyl-d-aspartate receptors over- or down-regulation.     

Lipoperoxidation rates and drug-oxidizing enzyme activities in the liver and placenta of some mammal species during the perinatal period

Summary Lipoperoxidation and drug-metabolizing enzymes were measured in livers and placentas of different mammal species during the perinatal period. In placentas and fetal livers of rat, rabbit and guinea-pig, cofactor-supported lipoperoxidation was negligible, as were the activities of drug-oxidizing enzymes. Human fetal liver contained an intact drug-oxidizing electron transport chain, and lipoperoxidation activity was accordingly observed. It is suggested that lesions mediated by lipoperoxidation may be possible in human fetus, but they are less probable in animal fetuses.The skillful technical assistance of Ms.Liisa Tuhkanen and Ms.Vuokko Väisänen is gratefully acknowledged.     

Thermische Denaturierung von Kaltblüter-Enzymproteinen

Summary The temperature, which leads to 50% reduction of catalytic activity by heat denaturation, has been determined for 8 different enzymes from cod muscle, as being in the range between 30 and 52°C. Therefore, there are no indications of a generally different heat resistance of enzymes from cold-blooded animals as compared with those from warm-blooded animals. The same conclusion is derived from calculations ofQ ₁₀-values, measured between +37 and – 37°C for cathepsin and glycylglycine dipeptidase.

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Die Untersuchungen wurden dankenswerterweise durch eine Beihilfe des Bundeswirtschaftsministeriums Bonn unterstützt. HerrnDegener, i. Fa. Hanseatische Hochseefischerei A.G., Bremerhaven-F., verdanken wir das Untersuchungsmaterial.     

Unsaponifiable constituents inSpirographis spallanzani

Riassunto L'insaponificabile del muscolo diSpirographis spallanzani contiene accanto a steroli e tocoferolo, un composto di natura chinonica avente molte proprietà in comune con gli ubichinoni. Anche il tocoferilchinone è stato identificato negli estratti. Si ritiene però che esso si formi dal tocoferolo durante il procedimento di estrazione.

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This work has been partially supported by a U.S. Public Health Service Grant (R.G. 4845). The authors gratefully acknowledge suggestions and criticisms from Dr.Hemming and Dr.Pennock, Biochemistry Department, Liverpool.     

Interaction between 6-hydroxydopamine and rhodopsin in vivo in the rat retina

Résumé Nous avons observé que l'injection de la 6-hydroxydopamine dans l'humeur vitrée des rats adaptés à la lumière bloquait le rétablissement de la sensibilité rétinale pendant l'adaptation à l'obscurité subséquente au traitement. Il est possible que cette observation soit une conséquence de la réaction du produit de l'oxydation de la 6-hydroxydopamine avec les groupes nucléophiliques de la rhodopsine.

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This study was partially supported by Postdoctoral Training Grant No. MH 10965 to S.F.P. and by Eli Lilly Co., Research to Prevent Blindness, Inc., and NSF No. GB-39853 to L.T.G. Samples of 6-aminodopamine were kindly supplied by Drs.R. N. Adams (University of Kansas, Lawrence, Kansas) andE. L. Engelhardt (Merck Sharp and Dohme Res. Labs. West Point, Pa.) andp-quinone by Dr.P. A. Wehrli (Hoffmann-La Roche, Nutley, New Jersey). The authors thank Mr.L. Tomey for excellent technical assistance.     

The endocannabinoid system in rat gliosomes and its role in the modulation of glutamate release

The endocannabinoid system and endocannabinoid receptor-driven modulation of glutamate release were studied in rat brain cortex astroglial gliosomes. These preparations contained the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, as well their major biosynthetic (N-acyl-phosphatidylethanolamines-hydrolyzing-phospholipase D and diacylglycerol-lipase) and catabolic (fatty acid amide-hydrolase and monoacylglycerol-lipase) enzymes. Gliosomes expressed type-1 (CB1R), type-2 (CB2R) cannabinoid, and type-1 vanilloid (TRPV1) receptors, as ascertained by Western blotting and confocal microscopy. Methanandamide, a stable analogue of anandamide acting as CB1R, CB2R, and TRPV1 agonist, stimulated or inhibited the depolarization-evoked gliosomal [³H]d-aspartate release, at lower and higher concentrations, respectively. Experiments with ACEA (arachidonyl-2′-chloroethylamide), JWH133 ((6aR,10aR)-3-(1,1-dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]-pyran) and capsaicin, selective agonists at CB1R, CB2R and TRPV1, respectively, demonstrated that potentiation of [³H]d-aspartate release was due to CB1R while inhibition to CB2R and TRPV1 engagement. These findings were confirmed by using selective receptor antagonists. Furthermore, CB1R activation caused increase of intracellular IP3 and Ca²⁺ concentration, suggesting an involvement of phospholipase C.     

Ultrastructural aspects of nucleolar fibrillar centres in meristematic cells ofAllium cepa

Summary This paper deals with the fine structure of the fibrillar centres of the nucleolus inAllium cepa cells in ultrathin, sections of in vivo fixed roots. The ultrastructural observations have allowed us to consider each nucleolar fibrillar centre as an active zone in the nucleolar chromatin loop, and to propose a possible model for the organization of the different components of the nucleolus within it.Acknowledgments. The author wishes to thank Dr.M. C. Risueño for her valuable comments and discussion. This work has been partially supported by the III Plan de Desarrollo of Spain and by a grant of the Foundation Rodriguez Pascual.     

Newton and the classical theory of probability

Summary Probabilistic ideas and methods from Newton's writings are discussed in § 1: Newton's ideas pertaining to the definition of probability, his probabilistic method in chronology, his probabilistic ideas and method in the theory of errors and his probabilistic reasonings on the system of the world. Newton's predecessors and his influence upon subsequent scholars are dealt with in §2: beginning with his predecessors the discussion continues with his contemporaries Arbuthnot and De Moiver, then Bentley. The section ends with Laplace, whose determinism is seen as a development of the Newtonian determinism.An addendum is devoted to Lambert's reasoning on randomness and to the influence of Darwin on statistics. A synopsis is attached at the end of the article.Abbreviations PT abridged Philosophical Transactions of the Royal Society 1665–1800 abridged. London, 1809 - Todhunter I. Todhunter, History of the mathematical theory of probability, Cambridge, 1865 To the memory of my mother, Sophia Sheynin (1900–1970)     

Chebyshev's lectures on the theory of probability

Communicated by B. Bru     

Effect of ACTH on the zona reticularis of the rat adrenal cortex: An ultrastructural stereologic study

Summary The effects of ACTH on the rat adrenalzona reticularis were investigated by stereologic methods. It was found that thezona reticularis cell responsiveness to ACTH is similar to that of thezona fasciculata elements. This excludes that thezona reticularis of the adult rat can only function as the site of destruction of worn-out elements migrating from the adrenal outer zones.Acknowledgment. We wish to thank Mr.G. Gottardo for his skilled technical assistance. This work was partly supported by a contract with the CNR No. C.T.73.00663.04.     

Pseudomonas aeruginosa cause epidemic disease in the milkweed bug,Oncopeltus fasciatus dallas (Insecta,Heteroptera)

Summary Pseudomonas aeruginosa was recognized as the causative organism of an epidemic disease occurring in a laboratory breed ofOncopeltus fasciatus. The infection probably occurs peroral and is favoured by high temperature and humidity.Pseudomonas aeruginosa destroys the fat body of the bug.For her interest and discussion I thank Dr.G. Hausner, Miss I. vonGraevenitz and Miss.H. Schilling gave techincal support.     

P.S. Laplace's work on probability

Taken together with my previous articles [77], [80] devoted to the history of finite random sums and to Laplace's theory of errors, this paper sheds sufficient light on the whole work of Laplace in probability. Laplace's theory of probability is subdivided into theory of probability proper, limit theorems and mathematical statistics (not yet distinguished as a separate entity). I maintain that in its very design Laplace's theory of probability is a discipline pertaining to natural science rather than to mathematics. I maintain also the idea that the so-called Laplacian determinism was no hindrance to applications of his theory of probability to natural science and that one of his utterances in this connection could have well been made by Maxwell's contemporaries.Two possible reasons why the theory of probability stagnated after Laplace's work are singled out: the absence of new fields of application and, also, the insufficient level of mathematical abstraction used by Laplace. For all his achievements, I reach the general conclusion that he did not originate the theory of probability as it is now known. Dedicated to the memory of my Father, Boris A. Sheynin (1898–1975), the first generation of the Russian revolution Cette inégalité [Lunaire] quoique indiquée par les observations, était négligée par le plus grand nombre des astronomes, parce qu'elle ne paraissait pas résulter de la théorie de la pesanteur universelle. Mais, ayant soumis son existence au Calcul des Probabilités, elle me parut indiqués avec une probabilité si forte, que je crus devoir en rechercher la cause.(P. S. Laplace (Théor. anal. prob., p. 361))     

Osservazioni preliminari,chimiche e farmacologiche,sulla murexina

Summary (1) Murexine, a new choline derivative found in the hypobranchial body ofMurex trunculus, Murex brandaris, andTritonalia erinacea, was isolated as picrate, picrolonate, styphnate, flavianate, and reineckate. Some preliminary characteristics of these salts are given.(2) The murexine content of the median zone of the hypobranchial body ofMurex trunculus is extremely high: murexine picrate equivalents of 45–70 mg per g fresh tissue are commonly observed.(3) Murexine manifests intense nicotinic and curariform actions, but is practically wanting in any muscarinic activity.The central nervous system is strongly affected by the substance: at first stimulation seems to prevail, but later on, with larger doses, a deep depression regularly develops.In decapitated cats and dogs murexine causes a significant rise in blood pressure, which is due, at least partially, to a liberation of epinephrine from the adrenal medulla and from the adrenergic nerve terminals.On the enucleated eye of frogs andOctopoda the substance acts to cause mydriasis and expansion of the iris chromatophora.

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V. Erspamer eF. Dordoni, Arch. int. Pharmacodyn.74, 263 (1947).     

Diphasic action of the aliphatic amide,HOE 17879, on hepatic microsomal drug metabolizing enzymes in the mouse

Summary -Hydroxy--ethylbutyryl-diethylamide (HOE 17879) influences the hepatic microsomal drug hydroxylating enzyme system of mice in a two-phasic way: First it reduces the overall reaction of drug hydroxylation but not the single enzymes whilst in the second period it increases enzyme activities.Acknowledgments. The authors are indebted to their colleague, Dr.K. Schmitt, for making the substance HOE 17879 available. They wish to thank to Mr.Mayer, Mr.Paulusch Mrs.Fey, Mrs.Stein, and MissFehlings for their skilful assistance in the project.     

The influence of a queen on the ovary development in worker bees

Zusammenfassung Unabhängig voneinander haben in den letzten Jahren einerseitsButler, andererseitsde Groot undVoogd gefunden, dass der Einfluss, den die Anwesenheit einer Königin auf die Arbeiterinnen der Honigbiene ausübt, durch Aufnahme einer Substanz bedingt ist, die die Arbeiterinnen vom Körper der Königin ablecken, und die vonButler als «queen substance» bezeichnet wurde. Als Kriterium benütztenButler den Bau von Weiselzellen,de Groot undVoogd die Ovarienentwicklung bei den Arbeiterinnen. Den zuletzt genannten Autoren gelang es weiterhin, die wirksame Substanz zu extrahieren und in Extraktform erfolgreich anzuwenden.AuchPain hat sich in mehreren Veröffentlichungen zu diesen Fragen geäussert; ihre Schlussfolgerungen sind aber durchwegs experimentell nicht ausreichend begründet.In weiteren Versuchen konnte gezeigt werden, dass dieAufnahme der extrahierten Substanz durch die Arbeiterinnenan sich (mit dem Futter) noch keinen Effekt (Hemmung der Ovarienentwicklung) hervorruft. Dazu musste der Extrakt — mit oder ohne Futter —in besonderer Weise dargeboten werden (zum Beispiel auf der Leiche einer Arbeiterin). Nur dann auch wirkte die Substanz anziehend auf die Arbeiterinnen und löste ein charakteristisches Verhalten aus, dessen Bedeutung für die Hemmung der Ovarienentwicklung weitere Experimente näher aufklären sollen.     

Kepler,Tycho, and the ‘Optical Part of Astronomy’: the genesis of Kepler's theory of pinhole images

In the last half of the 16^th century, the method of casting a solar image through an aperture onto a screen for the purposes of observing the sun and its eclipses came into increasing use among professional astronomers. In particular, Tycho Brahe adapted most of his instruments to solar observations, both of positions and of apparent diameters, by fitting the upper pinnule of his diopters with an aperture and allowing the lower pinnule with an engraved centering circle to serve as a screen. In conjunction with these innovations a method of calculating apparent solar diameters on the basis of the measured size of the image was developed, but the method was almost entirely empirically based and developed without the assistance of an adequate theory of the formation of images behind small apertures. Thus resulted the unsuccessful extension of the method by Tycho to the quantitative observation of apparent lunar diameters during solar eclipses. Kepler's attention to the eclipse of July 1600, prompted by Tycho's anomalous results, gave him occasion to consider the relevant theory of measurement. The result was a fully articulated account of pinhole images. Dedicated to the memory of Ronald Cameron Riddell (29.1.1938–11.1.1981)