Showing papers by "University of Bonn published in 1970"

The myothelia (myoepithelial cells). Normal state; regressive changes; hyperplasia; tumors.

Abstract: The myoepithelial cells are indeed a fascinating type of cell, in that they appear to belong to two widely divergent types of tissues, namely the epithelium and the mesenchyma. This two-sided nature is expressed not only by their position (on the one hand they are connected in typical manner with the secreting epithelium, whereas on the other hand they interact with the stroma and the basal membrane in the same way as smooth muscle fibres), but also by their possession of potentialities of both kinds of tissue, although these potentialities become apparent only under pathological conditions of growth. This concept is the key-note of the following paper, whose purpose is to report a comparative study of the myoepithelia of various organs. Many phenomena that were detectable and detected in only one organ, will be used to elucidate certain otherwise obscure changes in other organs. First we shall examine the normal myoepithelia of various tissues (I), then consider regressive changes (II) and hyperplasia (III), in order to apply the information thus obtained to the problem of tumors (IV, V). To some extent, therefore, this paper constitutes a continuation of my paper from 1939 “On the myothelia of the mammary gland”. Additional material has been collected since then; unfortunately, however, some of the relevant documents were lost during the war and in the post-war period.

Ultrastructural study of characteristic organelles (paired organelles, micronemes, micropores) of sporozoa and related organisms.

Abstract: By means of electron microscopy a study has been made of different developmental stages of Eimeria callospermophili, E. falciformis, Toxoplasma gondii, Frenkelia spec. (= M-organism), Babesia bigemina, and B. ovis. Major emphasis was given to the analysis of some characteristic organelles of the motile stages of the sporozoans. These organelles were the paired organelle, the micronemes and the micropores.

The fine structure of the conoid of sporozoa and related organisms

Abstract: The merozoites ofEimeria callospermophili andE. stiedae as well as the zoites ofToxoplasma gondii and the M-organism and the erythrocytic merozoites ofBabesia bigemina were studied by means of electron microscopy. The fine structure of the apical pole was analysed, and compared with the results of other studies of sporozoa and related organisms. The following conclusions were made:

Structure activity relationship of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts of Cannabis sativa

Abstract: The structure activity relationships of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts from Cannabis sativa were studied using four biological methods: corneal areflexia in rabbits (Gayer test) and catatonia, decrease of motor activity and suppression of isolation-induced aggressiveness in mice. Modifications in the structure of pure, natural Δ9-THC rendered the resultant compounds inactive only when activity was measured by the Gayer test; by the other three methods the activity ranged from 1/5th to equal to the activity of pure Δ 9-THC. It was concluded that of the methods employed, the Gayer test was the only useful procedure to measure Δ 9-THC content in mixtures. This was confirmed by the relationship found between Δ 9-THC content and activity using five semi-purified extracts.

Quantitative Veränderungen „Gomori-positiver” Substanzen in Infundibulum und Hypophysenhinterlappen der Ratte nach Adrenalektomie und Kochsalzoder Durstbelastung

Abstract: An normalen und bilateral adrenalektomierten Ratten wird der Einflus von Belastungen des Salz- und Wasserhaushaltes auf die Menge „Gomori-positiver” Substanzen in der Zona externa infundibuli und im Hypophysenhinterlappen untersucht. Die quantitativen Untersuchungen erfolgen an histologischen Praparaten, die nach einer modifizierten Aldehydfuchsin-Methode (Crotonaldehyd-Pararosanilin) gefarbt sind. Bei normalen Ratten enthalt die Zona externa infundibuli nur geringe Mengen „Gomori-positiver” Substanzen. Nach bilateraler Adrenalektomie nimmt die Menge dieser Substanzen erheblich zu. Die Substanzmenge wird durch anschliesende Durst- oder Kochsalzbelastung wieder vermindert. Die Neurosekretmenge des Hypophysenhinterlappens wird sowohl bei normalen als auch bei adrenalektomierten Ratten durch Durst- oder Kochsalzbelastung reduziert. Die Entleerung des Hypophysenhinterlappens ist bei Normaltieren ausgepragter als bei adrenalektomierten Tieren. Bezogen auf die Verminderung des Neurosekrets im Hypophysenhinterlappen nehmen die „Gomori-positiven” Substanzen in der Zona externa infundibuli bilateral adrenalektomierter Ratten im Durstversuch starker ab als bei Kochsalzbelastung. Die Ergebnisse sprechen dafur, das die „Gomori-positiven” Granula in der Zona externa infundibuli und im Hypophysenhinterlappen aus verschiedenen aber ahnlichen Substanzen bestehen. Die „Gomori-positiven” Substanzen in der Zona externa infundibuli werden als das morphologische Aquivalent des β-Corticotropin-releasing factor angesehen.

Treatment of the Three- and Four-Nucleon Systems by a Generalized Separable-Potential Model

Abstract: A formalism, proposed previously, which represents a generalization of the separable-potential model is applied to the four-nucleon system. It consists essentially in approximating the off-shell nucleon-deuteron scattering amplitude---as obtained in the separable-potential model---again by separable expressions. We arrive thereby at effective two-particle equations which are solvable by standard methods. The determination of the required separable terms is studied in detail. A first attempt to solve approximately our final integral equations is made. The results demonstrate the applicability of the method.

Die Struktur von Panepoxydon und verwandten Pilzmetaboliten

Abstract: The structure of panepoxydone (1) and some related products, produced by two species of Panus (basidiomycetes), are proposed on the basis of chemical transformations and physical measurements. The absolute configurations of the main products are deduced by the interpretation of CD. studies and compared with those of the structurally related compounds epoxydone (10), terreic acid (11) and terremutin (12).

Zur gas-chromatographisch-massenspektrometrischen Bestimmung von Steroidhormonen in Körperflüssigkeiten unter Verwendung eines Multiple Ion Detectors (Fragmentographie)

Abstract: Die quantitative Bestimmung geringer Steroidkonzentrationen in Korperflussigkeiten erfordert mit den heute bekannten physikalisch-chemischen Verfahren (Gas-Chromatographie, Doppelisotopenderivatverdunnungsmethoden) einen erheblichen methodischen und zeitlichen Aufwand. Eine wesentliche Vereinfachung bei hoher Empfindlichkeit und Spezifitat bietet der Einsatz des Gas-Chromatographen-Massenspektrometers. Hierbei wird das Massenspektrometer als hochspezifischer Detektor fur den Gas-Chromatographen benutzt; dies erfolgt durch Einstellung eines geeignetenm/e-Wertes. Mit Hilfe des Multiple Ion Detectors ist es auch moglich, mehrere Massen gleichzeitig aufzuzeichnen. Die Brauchbarkeit dieses Verfahrens wurde am Beispiel folgender Methoden zur Bestimmung von Steroidhormonen demonstriert: Testosteron im Plasma, Aldosteron im Urin, Oestradiol-17β und Oestron im Plasma. Als besonders vorteilhaft erwies sich bei der quantitativen Bestimmung der Oestrogene die Verwendung der entsprechenden Dideuteroverbindungen als Standardsubstanzen. Die vorlaufigen Nachweisgrenzen der hier angegebenen Verfahren liegen fur Aldosteron und Testosteron bei 1 ng, fur Oestron und Oestradiol-17β bei 0,05 ng.

The ultrastructure of medulloblastomas.

Abstract: 9 medulloblastomas were investigated by electron microscopy. They all showed a rather unique histological and cytological structure. The cells were differently shaped, had in general many cytoplasmic processes and only few organells. Special differentiations which would have made tumour elements look like glial or neural cells were not observed when the tissue samples under investigation were carefully selected by light microscopical examination. Glial or neural elements were found only in infiltration zones where no clear distinction between pre-existing cerebellar and tumourous tissues could be made by conventional histological investigation. Medulloblastomas have essentially the same appearance as parvicellular sarcomas or embryonic tissues. Their common characteristic, viz. that they usually show no special differentiation, is also the most specific quality of medulloblastomas.

Die Chloridzellen des Stichlings

Abstract: Dreistachlige Stichlinge (Gasterosteus aculeatus) aus Suswasserbiotopen wurden in mehreren Versuchsgruppen allmahlich an Meersalzlosungen steigender bzw. fallender Konzentration adaptiert. Dabei stellte sich heraus, das diese euryhaline Fischart Salzkonzentrationen zwischen 1 mg-% und 5,6% tolerieren kann. Der letzte Wert bedeutet das 1,6fache der durchschnittlichen Meerwasserkonzentration. Stichlinge aus verschiedenen salzreichen und salzarmen Adaptationsstufen dienten als Ausgangsmaterial zur elektronenmikroskopischen Untersuchung der Chloridzellen.

Über die gemeinsame Einwirkung von Ammoniak (Aminen, Iminen) und Tetrachlorkohlenstoff auf Phosphine, I

Abstract: Eine neue Methode zur bequemen Darstellung von Amino(Imino)-phosphoniumchloriden wird beschrieben. Sie beruht auf der gemeinsamen Einwirkung von Ammoniak (Aminen, Iminen) und Tetrachlorkohlenstoff auf Phosphine. Neben dem Amino(Imino)-phosphonium-chlorid entsteht als einziges Nebenprodukt noch Chloroform. Der Reaktionsmechanismus wird diskutiert. The Simultaneous Action of Ammonia (Amines, Imines) together with Carbontetrachloride on Phosphines, I A new method for a convenient preparation of amino(imino)-phosphonium chlorides is presented. It involves the simultaneous reaction of ammonia (amines, imines) and carbontetrachloride with phosphines. Chloroform is the only by-product formed in the reaction. The possible reaction mechanism is discussed.

A new method for the production of atomic beams of highly refractory elements and first atomic beam magnetic resonances in Ta 181

Abstract: A new universal method for the production of atomic beams of highly refractory elements has been developed. The beams of free atoms are produced by locally heating a small area on a target consisting of the material to be evaporated. The local heating is achieved via the focussed electron beam of a commercial electron gun. The atomic beams so obtained are suitable for studying hyperfine structures by the atomic beam magnetic resonance method. The first observedrf resonances in the ground state4F3/2 and the first excited state4F5/2 of Ta181 are reported.

On the quasivariety of convex subsets of affine spaces

Abstract: By Maleev's theorem a quasivariety of algebras is determined up to rational equivalence by its underlying concrete category (that is category with underlying set functor), so one loses nothing ff one identifies a quasivariety with its underlying concrete category. In this paper we show tha t the concrete category ~ of convex subsets of real affine spaces and restrictions to convex subsets of affine maps is an axiomatic quasivariety, and we describe the algebraic structure of ~. F~rrz OSTERMA~N and Jt)RGV, N SCHMIDT have shown in [4] tha t the concrete category 9 /of real affine spaces and affme maps is a variety, and have described the algebraic structure. Their result is stated in section 1. The axiomatisation of convex subsets of affine spaces as algebras is ~ v e n in section 2 and proved in section 3. The final section is devoted to a general discussion of the quasivariety ~ and the var iety generated by it. I n particular we show tha t !~ has only one nontrivial proper subvariety, namely the variety of semilattices. In the following affine spaces will always be affine spaces over the real numbers R. We remark tha t OSTERMA~N and SCHMIDT proved their result for affine spaces over more general rings.

Representing varieties of algebras by algebras

Abstract: In this paper we describe a way of representing varieties of algebras by algebras. That is, to each variety of algebras we assign an algebra of a certain type, such that two varieties are rationallv equivalent if and only if the assigned algebras are isomorphic.

Enamine cyclischer 1.3-Diketone als Ausgangsstoffe für Pyridinringsynthesen

Abstract: Fur das bisher unbekannte 1-Amino-cyclopenten-(l)-on-(3) (5) wird eine ergiebige Synthese beschrieben. Kondensation von 5 mit 1.3-Dicarbonylverbindungen fuhrt zu Pyridinderivaten, wobei die Ausbeuten i.a. geringer sind als beim homologen l-Amino-cyclohexen-(l)-on-(3) (1). Enamines of Cyclic 1,3-Diketones as Starting Materials for Pyridine Ring Syntheses 1-Aminocyclopent-1-en-3-one (5), the primary enamine of cyclopentane-1,3-dione, has been synthesized for the first time. 5 reacts with 1,3-dicarbonyl compounds to form pyridine derivatives in yields which are generally lower than those obtained with the homologous 1-amino-cyclohex-l-en-3-one (1).

[The L-isomer as teratogenic principle of N-phthalyl-DL-glutamic acid].

Abstract: The teratogenicity of optical antipodes of phthaloyl-glutamic acid, a metabolite of thalidomide, was determined by administering i.p. to pregnant mice. The injected solution contained Tween 20 as solubilizer. Under the conditions of experiment thel-isomer was found to be embryotoxic; whereas thed-form was devoid of any embryopathic properties.

Die thermische Spaltung des Tetraphenylhydrazins. Ein Beitrag zum Problem der nicht katalysierten Benzidin‐Umlagerung

Abstract: Bei der thermischen Zersetzung des Tetraphenylhydrazins (4) entstehen neben Diphenylamin nur das o- und das p-Semidin 6a und 7a, sowie Folgeprodukte davon. Die Bildung der anderen denkbaren Umlagerungsprodukte von 4, die auf unabhangigen Wegen synthetisiert wurden, kann ausgeschlossen werden. Die Ergebnisse werden im Vergleich zu fruheren Arbeiten uber die thermische Benzidin-Umlagerung und Vorstellungen uber ihren Mechanismus diskutiert. The Thermal Decomposition of Tetraphenylhydrazine. A Contribution to the Problem of the Non-catalysed Benzidine Rearrangement The thermal decomposition of tetraphenylhydrazine (4) affords besides diphenylamine only the o- and the p-semidine 6a and 7a, respectively, and compounds derived from them. None of the other possible rearrangement products, which were synthesized independently, is formed. The results are compared with previous work on the thermal benzidine rearrangement and its mechanism.

[Fluorescence microscopy demonstration of aldehyde fuchsin-positive substances with crotonaldehyde-diaminobenzophenone].

Abstract: Es wird ein Verfahren zur elektiven Fluorochromierung Aldehydfuchsin-positiver Gewebsstrukturen beschrieben. Bei dem verwendeten Fluorochrom handelt es sich um eine Verbindung, die aus Crotonaldehyd und 4,4′-Diamino-benzophenon entsteht.