Expression of monoclonal antibody-defined cell surface antigens during rat brain development

Using single-cell suspensions of mechanically dissociated, prenatal BDIX-rat brain cells (13th, 15th, and 21st days after fertilization) for immunization, we have established a collection of 37 monoclonal antibodies (Mabs) directed against neural cell surface determinants. The developmental-stage-dependent expression of cell-surface antigens recognized by these Mabs was analyzed both on plasma membranes isolated from whole brains of BDIX rats (prenatal days 13-22 and adults) using an indirect 125I solid-phase radioimmunoassay, and on intact BDIX-rat brain cells (prenatal days 13-22) using a fluorescence-activated cell sorter. Different types of developmental stage-dependent profiles of Mab binding were found, these being indicative of the presence of neural cell surface determinants whose expression increases, decreases, or does not change with brain development. Some of the Mab-binding profiles showed transient changes as a function of developmental stage. These Mabs are currently being used for the characterization, reproducible identification, and isolation of neural cell subpopulations of the developing rat brain, with the aim of investigating the cell type dependence and developmental (differentiation) stage dependence of malignant transformation following pulse exposure to the carcinogen N-ethyl-N-nitrosourea at defined stages of brain development.     

Peroxidase-mediated binding of diethylstilbestrol analogs to DNA in vitro: A possible role for a phenoxy radical

In order to investigate the role of peroxidase-mediated metabolic activation in the mechanism of carcinogenicity of diethylstilbestrol (DES), a series of ¹⁴C-labelled analogs of DES was synthesized and their binding to DNA upon oxidation by peroxidases from horseradish or mouse uterus was studied in vitro. The compounds chosen for this study were the erythro and threo form of hexestrol (HES), the E,E- and Z,Z-isomer of dienestrol (DIES) and the mono- and dimethyl ether of DES.

Non-extractable binding to DNA was observed for all compounds with at least one free hydroxyl group independent of the stilbene structure. The extent of binding was highest for the HES isomers and for E,E-DIES, whereas Z,Z-DIES and the monomethyl ether were bound to about the extent of DES. These findings imply that the formation of a phenoxy free radical is sufficient for non-extractable DNA binding and the stilbene structure is not required for peroxidase-mediated activation of DES.     

Molecular cloning of the F8 fimbrial antigen from Escherichia coli

Abstract The genetic determinant coding for the P-specific F8 fimbriae was cloned from the chromosome of the Escherichia coli wild-type strain 2980 (O18:K5:H5:F1C, F8). The F8 determinant was further subcloned into the Pst I site of pBR322 and a restriction map was established. In a Southern hybridization experiment identity between the chromosomally encoded F8 determinant of 2980 and its cloned counterpart was demonstrated. The cloned F8 fimbriae and those of the wild type strain consist of a protein subunit of nearly 20 kDa. F8 fimbriated strains were agglutinated by an F8 polyclonal antiserum, caused mannose-resistant hemagglutination and attached to human uroepithelial cells. The cloned F8 determinant was well expressed in a variety of host strains.     

3',5'-Cyclic Adenosine Monophosphate- and Ca2+-Calmodulin-Dependent Endogenous Protein Phosphorylation Activity in Membranes of the Bovine Chromaffin Secretory Vesicles: Identification of Two Phosphorylated Components as Tyrosine Hydroxylase and Protein Kinase Regulatory Subunit Type II

Abstract: Membranes of the secretory vesicles from bovine adrenal medulla were investigated for the presence of the endogenous protein phosphorylation activity. Seven phosphoprotein bands in the molecular weight range of 250,000 to 30,000 were observed by means of the sodium dodecyl sulphate electrophoresis and autoradiography. On the basis of the criteria of molecular weight, selective stimulation of the phosphorylation by cyclic AMP (as compared with cyclic GMP) and immunoprecipitation by specific antibodies, band 5 (molecular weight 60,300) was found to represent the phosphorylated form of the secretory vesicle-bound tyrosine hydroxylase. The electrophoretic mobility, the stimulatory and inhibitory effects of cyclic AMP in presence of Mg²⁺ and Zn,²⁺ respectively, and immunoreactivity toward antibodies showed band 6 to contain two forms of the regulatory subunits of the type II cyclic AMP-dependent protein kinase, distinguishable by their molecular weights (56,000 and 52,000, respectively). Phosphorylation of band 7 (molecular weight 29,800) was stimulated about 2 to 3 times by Ca²⁺ and calmodulin in the concentration range of both agents believed to occur in the secretory tissues under physiological conditions.     

Immuno-electron-microscopic evidence of ecdysteroids in Y-organ of Orconectes limosus (Crustacea,Decapoda)

Ecdysone was demonstrated by ultrastructural immunocytochemistry to be present in the mitochondria of the Y-organs of the crayfish Orconectes limosus. This is in remarkable contrast to the prothoracic glands of insects and suggests substantial differences in the biosynthesis of the same hormone, ecdysone, in crustaceans and insects.     

Zum Vorkommen des Stelzenl?ufersHimantopus h. himantopus in den Philippinen

Ohne Zusammenfassung     

Flavonglykoside in Blüten vonPaeonia arborea undPaeonia suffruticosa

Summary Three glycosides have been isolated fromPaeonia arborea: kaempferol-3--glucoside-7--glucoside (Paeonoside), apigenin-7--glucoside, and apigenin-7-rhamnoglucoside (Rhoifolin).Paeonia suffruticosa also contains these three compounds but its main glycoside is kaempferol-3--glucoside (astragalin), which is present inPaeonia arborea only in traces.     

Veronica caespitosa Boiss.,V. bombycina Boiss.&Kotschy undV. thessalica Benth. gehören nicht in die SektionVeronicastrum Benth.

Zusammenfassung Die drei hochalpinen Polster-ZwergsträucherVeronica caespitosa Boiss.,V. bombycina Boiss. &Kotschy aus Kleinasien und dem Libanon sowieV. thessalica aus Nord-Griechenland und Albanien haben polytele Rumpfsynfloreszenzen (Troll, 1963), das heißt eine oder wenige laterale (axilläre) wenigblütige Trauben, deren Abstammungsachse in einen sterilen, wenige Blattpaare tragenden Gipfelsproß endet, der in der nächsten Vegetationsperiode monopodial weiterwächst und gegen die Spitze zu abermals laterale Trauben hervorbringt (Prolifikation). Diese Bauverhältnisse wurden bisher übersehen, da die blühenden Sprosse dieser hochalpinen Zwergstrauch-Polsterpflanzen gestaucht und dicht beblättert sind und der sterile Sproßgipfel von den Blütentrauben zur Seite gedrängt wird, so daß bei oberflächlicher Betrachtung der Eindruck eines endständigen köpfchenartig gedrängten Blütenstandes entsteht. Da die Stellung der Infloreszenzen für die GattungVeronica phylogenetisch und taxonomisch wichtig zu sein scheint, können die behandelten drei Arten nicht in der (akrobotryschen) SektionVeronicastrum verbleiben, die durch terminale Infloreszenzen charakterisiert ist, sondern müssen in die pleurobotrysche, durch ausschließlich laterale Infloreszenzen ausgezeichnete SektionenVeronica=(Chamaedrys) eingereiht werden.Ein fälschlich alsV. satureioides Vis. bestimmter Beleg in den Herbarien W und WU vonV. thessalica vom Gipfel des Berges Gjalica e Lumës (zirka 2470 m s. m.) in Nord-Albanien erweitert das bekannte Areal beträchtlich, denn die Art war bisher nur von dem etwa 250 Kilometer weiter südöstlich gelegenen Thessalischen Olymp in Griechenland bekannt.

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Summary The three speciesVeronica caespitosa Boiss. andV. bombycina Boiss. &Kotschy from high mountains of Asia Minor and the Lebanon andV. thessalica from high mountains of Northern Greece and Albania have not terminal but only one or a few lateral (axillary) raceme(s), the shoot ending sterile, continuing (prolificating) next year monopodially and developping again (a) lateral raceme(s) (fig. 1a, b). This fact hitherto has been concealed by the habit of these dwarfish undershrubs with densly crowded foliation, the raceme(s) overlapping and putting aside the short terminal shoot (fig. 1a). Thus the three species mentioned have to be transferred from the sectionVeronicastrum with terminal racemes to the sectionVeronica (=Chamaedrys), characterized by bearing only lateral racemes. V. thessalica until now was recorded only from the Thessalic Olympos (Greece). A speciemen in the herbaria W and WU from the peak of the mountain Gjalica e Lumës (2470 m s. m.) in Northern Albania, misidentified asV. satureioides Vis., makes it probable, that the area of this species covers also the high mountains between Albania and the Thessalic Olympos.

     

Licht- und elektronenmikroskopische Untersuchungen über die Beeinflussung der Dynamik neurosekretorischer Zellen von Enchytraeus (Oligochaeta) durch Aktinomycin D

Zusammenfassung Die Wirkung von Aktinomycin auf die neurosekretorischen Q-und P-Zellen im Cerebralganglion von Enchytraeus wurde untersucht. Die Cytophotometrie lichtmikroskopischer Präparate von Q-Zellen ergab, daß in den ersten Stunden nach Aktinomycin-Behandlung eine deutliche Verminderung PAF-positiven Materials auftritt. Die ersten Veränderungen wurden elektronenmikroskopisch zwischen 1 und 4 Std nach Aktinomycin-Injektion beobachtet. Sie waren in beiden Zelltypen am eindeutigsten am Nucleolus. Es kommt zu einer Sonderung und räumlichen Trennung von granulärem und fibrillärem Material. Letzteres wird sehr stark vermehrt.In bezug auf Veränderungen der Strukturen des Cytoplasmas unterscheiden sich die Q-und P-Zellen besonders im Verhalten des Golgi-Apparates und der Ribosomen. Der Golgi-Apparat wird in den Q-Zellen kurze Zeit nach Applikation von Aktinomycin reduziert. In den P-Zellen persistiert er dagegen über alle beobachteten Zeitstufen hinweg. Die Ribosomen lösen sich von den Membranen in den Q-Zellen 4–8 Std nach Injektion, was in den P-Zellen nicht festzustellen ist. Diese Tatsachen führen zu der Annahme, daß das System der Proteinsynthese der P-Zellen relativ stabiler als das der Q-Zellen ist.Die in den späteren Zeitstufen beobachtete Normalisierung der Zellstrukturen läßt darauf schließen, daß die Wirkung des einmalig injizierten Aktinomycins 24 Std danach nachzulassen beginnt.

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Light and electron microscopic studies on the influence of actinomycin D on the dynamics of neurosecretory cells of Enchytraeus (Oligochaeta)

Summary The influence of actinomycin on the neurosecretory Q and P cells of the brain of Enchytraeus was studied. Cytophotometrical measurements of Q cells in light mirocscopic preparations showed a significant decrease of PAF-positive material in the first hours after actinomycin application. At the ultrastructural level primary changes were established one to four hours after injection of actinomycin: In the nucleolus granular and fibrillar material became separated; there was a substantial increase of the fibrillar component.Concerning structural changes of the cytoplasm, Q and P cells differed especially with respect to the Golgi apparatus and the ribosomes. In the Q cells the Golgi apparatus had become greatly reduced shortly after actinomycin treatment. However, it persisted in P cells during all stages examined. Ribosomes became detached from membranes only in Q cells between 4 and 8 hours after injection.These data indicate that protein synthesis in P cells shows greater stability than in Q cells. The restitution of normal ultrastruoture during subsequent stages indicates that effects begin to subside 24 hours after a single injection.

Für technische Unterstützung danken wir Frl. B. Reymann, Frl. A. Zinßer, Frau B. Cosack und Frau E. Wolschner.