Über die Blutkapillaren und perivaskulären Strukturen der Area postrema des Kaninchens und über ihr Verhalten im Pentamethylentetrazol-(„Cardiazol“-)Krampf

Zusammenfassung Die sinusförmigen Kapillaren der Area postrema werden von zwei Basalmembranen umgeben, die einen Raum einschließen, in dem Makrophagen liegen. Verästelte Ausläufer der äußeren Basalmembran dringen tief zwischen die Gliafortsätze ein und bilden ein Membranlabyrinth. Das Kapillarendothel ist fenestriert. Nach Cardiazolkrampf entsteht ein perivaskuläres Oedem, das das Membranlabyrinth öffnet und den perivaskulären Raum vergrößert. Das Endothel zeigt hierbei starke Cytopempsis. Die funktionelle Bedeutung der Strukturen wird diskutiert.

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Summary The sinusoid capillaries of the area postrema are surrounded by two basement membranes enclosing a perivascular space, in which macrophages are found. Ramified extensions of the outer basement membrane penetrate deeply between the glial processes forming a labyrinth of basement membranes. The capillary endothelium is fenestrated. After a Cardiazolinduced convulsion a perivascular edema opens the basement membrane labyrinth and the perivascular space is greatly enlarged. The endothelium shows pinocytotic activity. The functional significance of these structures is discussed.

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Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Zur Frage einer intraventrikulären Neurosekretion

Zusammenfassung In der vorderen Wand des IV. Ventrikels und des Canalis centralis gegenüber der Area postrema liegen beim Kaninchen Nervenzellen, deren Fortsätze intraventrikulär mit 6 großen Protoplasmakugeln endigen, die mit Mitochondrien angefüllt sind. Das Perikaryon ist reich an Ergastoplasma, alle Teile der Zelle enthalten leere, 600 bis 1500 Å messende, und ein dichtes Granulum enthaltende, 650–1000 Å große Bläschen. Vermutlich werden Stoffe in den Liquor cerebrospinalis abgegeben. Dem Plasmalemm der Nervenzellen liegen Synapsen an.

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Summary In the anterior wall of the IVth ventricle, opposite to the area postrema, nerve cells are found. Their processes end with spheroid swellings extending into the ventricle. These bulbs contain a large number of mitochondria, while ergastoplasm is seen in the perikaryon. The cytoplasm of the whole cell shows vesicles (600–1500 Å) and dense-core vesicles (650–1000 Å) which might be extruded into the liquor cerebrospinalis. The plasmalemma of the perikaryon is in contact with synapses.

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Die Untersuchung wurde mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft durchgeführt.     

Zur Blütenmorphologie und Bestäubungsökologie vonVeratrum album subsp.lobelianum (Bernh.)Rchb.

Zusammenfassung BeiVeratrum album subsp.lobelianum (Bernh.)Rchb. wurden im Gebirge Krkonoe (Riesengebirge) Blütenbau, Blütedauer und Blühverlauf studiert; besondere Berücksichtigung fanden dabei Vorkommen von Zwitterblüten und eingeschlechtlichen Blüten, Bau des Nektariums, Art und Weise der Nektarsekretion, Funktionsdauer der Narbe und Absinken der Keimfähigkeit des Pollens während der Anthese.Die Blütedauer der Zwitterblüten läßt eine deutliche Abhängigkeit von der Höhe ü. d. M. erkennen.Die (im Gegensatz zuVeratrum nigrum L.) weniger ausgeprägte Dichogamie erlaubt nur, ein männliches und ein Zwitterstadium der Blüte zu unterscheiden.Künstliche Bestäubungsversuche zeigten, daßV. album subsp.lobelianum weitgehend selbstfertil ist.Als regelmäßige Blumenbesucher und hauptsächlichste Bestäuber vonV. album susp.lobelianum wurden im obgenannten Gebirge 15 Dipteren-Arten (der Besucherzahl nach vorherrschend Aasfliegen) festgestellt, die ausgiebig Nachbar- und Fremdbestäubung (Geitonogamie, Allogamie), weniger schon Selbstbestäubung (Autogamie) bewirken.Die experimentelle Analyse des Blumenbesuches dieser Fliegen-Arten im Freiland ergab, daß ihre Fernanlockung durch den spezifischen Duft erfolgt, wobei die optische Wirkung der Blüten (Farbe, Form, Glanz der Nektarschicht) entbehrlich erscheint. Veratrum album susp.lobelianum kann bis zu einem gewissen Grade als aasblumig und ihre Blüte als Täuschblume bezeichnet werden.     

Das Verhalten von Ameisenarbeiterinnen gegenüber der Königin nach vorangegangener weisellosigkeit

Zusammenfassung Arbeiterinnen vonMyrmica ruginodis Nyl. werden im weisellosen Zustand fertil. Sie legen aber keine Eier, wenn sie mehr als 3 Larven je Arbeiterin zu versorgen haben (Mamsch, 1965). Arbeiterinnengruppen wurden mit und ohne Larven von der Königin abgetrennt. In den eierlegenden Gruppen wurde die erneut zugesetzte eigene Königin entweder nicht beachtet oder angegriffen. In den Gruppen, in denen die Arbeiterinnen durch Larvenpflege unfruchtbar blieben, wurde die Königin intensiv beleckt und in das engere Nest eingetragen. Isolierte eierlegende Arbeitergruppen zeigten im Gegensatz zu Arbeiterinnen mit inaktiven Ovarien keine Tendenz, sich mit der Königingruppe zu vereinigen. Das veränderte Verhalten der Arbeiterinnen gegenüber der Königin ist demnach nicht vom Zeitraum der Weisellosigkeit abhängig. Es wurde nur bei eierlegenden Arbeiterinnen beobachtet.

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Summary Workers ofMyrmica ruginodis Nyl. start laying eggs after being separated from their queen. No deposition of eggs occurs in groups in which each worker has to feed 3 or more larvae (Mamsch, 1965). Worker groups rearing larvae and those without brood were separated from the queen.When the queen was put again into an egg-laying worker group, either no attention was paid to her or she was attacked. In groups of workers sterile due to rearing larvae the queen was licked intensively and carried into the nest cavity. Fertile worker groups showed no tendency to join the queen group. The change in the workers' behaviour does not depend on the time of the separation from the queen. It only occurs in groups of fertile workers.

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Résumé Des ouvrières deMyrmica ruginodis Nyl. deviennent fertiles après avoir été séparées de la reine. Mais elles ne pondent pas d'ufs, si elles ont chacune trois larves ou plus à nourrir (Mamsch, 1965). Des groupes d'ouvrières, d'une part avec larves et d'autre part sans, ont été séparés de la reine. Les groupes d'ouvrières pondeuses n'attachaient pas d'attention à la reine replacée dans le nid ou encore l'attaquaient. Dans les groupes où les ouvrières étaient restées infertiles à cause du nourrissement du couvain, la reine était léchée d'une façon intensive et portée à l'intérieur du nid. A l'opposé des ouvrières stériles, les groupes d'ouvrières pondeuses isolées ne montraient aucune tendance à joindre le groupe de la reine. Le changement du comportement des ouvrières ne dépend donc pas de la durée de l'état orphelin; il n'est observé que chez les ouvrières pondeuses.

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Herrn Prof. Dr.K. Gösswald, zum 60. Geburtstag gewidmet.     

Antioxidant Activity of 5-Hydroxytryptophan, 5-Hydroxyindole, and Dopa Against Microsomal Lipid Peroxidation and Its Dependence on Vitamin E

The antioxidant capacity of 5-hydroxy-tryptophan. 5-hydroxy-indole. and DOPA (3,4-dihydroxy-phenyI-alanine) was tested in the Fe-induced lipid peroxidation of liver microsomes of normal- and vitamin E-deficient rats, using ascorbate as a reductant. Lipid peroxidation was monitored as low-level chemilu-minescence, indicative of generation of electronically-excited states arising from the recombination of secondary lipid peroxyl radicals.     

Chemiluminescent oxidation of ribose catalyzed by horseradish peroxidase in presence of hydrogen peroxide

The reaction of ribose with horseradish peroxidase in the presence of H₂O₂ is accompanied by light emission. The detection of horseradish peroxidase Compound II (FeO²⁺) indicates that the enzyme participates in a normal peroxidatic cycle. Hydrogen peroxide converts horseradish peroxidase into Compound I (FeO³⁺) which in turn is converted into Compound II by abstracting a hydrogen atom from ribose forming a ribosyl radical. In aerated solutions oxygen rapidly adds to the ribosyl radical. Based on the spectral characteristics and the enhancement of the chemiluminescence by chlorophyll-a, xanthene dyes, D₂O and DABCO, it is suggested that the excited species, apparently triplet carbonyls and ¹O₂, are formed from the bimolecular decay of the peroxyl radicals via the Russell mechanism.     

Clinical and biochemical studies in three patients with severe early infantile Cockayne syndrome

Summary We present clinical and biochemical data from three patients with severe Cockayne syndrome (CS) of very early onset. Unlike in classic CS, signs became evident in the first weeks of life and led to unusually early death. Fibroblasts from two of the patients showed a complete defect of the repair of UV-induced thymine dimer lesions. They were unable to remove thymine dimer lesions from their DNA, had a severe reduction of the RNA synthesis rates after UV irradiation, and showed no reactivation of an UV-inactivated indicator gene and no DNA recondensation after UV irradiation. DNA repair investigated in these two fibroblast cell strains resembled that of xeroderma pigmentosum cells of complementation group A. In contrast, fibroblasts from the third patient showed the same in vitro repair characteristics as classic CS cells.     

Binding characteristics and cross-reactivity of three different antilipid A monoclonal antibodies

A detailed characterization of binding specificity and cross-reactivity of three antilipid A murine mAb was performed. Binding characteristics of these three mAb were investigated against Ag (ReLPS, lipid A, derivatives of lipid A) in solid phase (ELISA) and in fluid phase (C consumption, inhibition studies), and upon incorporation in membranes (E: passive hemolysis assay, and liposomes: inhibition studies). Cross-reactivity with heterologous Ag was investigated in ELISA (LPS, Gram-negative bacteria) and immunoblot experiments (LPS). The binding specificity of mAb 26-5 (IgG2b), raised against synthetic lipid A, was located in the hydrophilic region of biphospholipid A and was also exposed after membrane incorporation of lipid A or after preincubation of lipid A with polymyxin B (PMX). mAb 26-20 (IgM), also raised against synthetic lipid A, showed binding specificity for the hydrophobic region of lipid A: no binding to membrane-associated lipid A could be demonstrated, and binding in ELISA could be blocked very efficiently by PMX. The reaction pattern of mAb 8-2 (IgM), raised against the heat-killed Re mutant of Salmonella typhimurium, was in part similar to that of mAb 26-20. However, inhibition of binding with PMX was less efficient and a high specificity for ReLPS, also after membrane incorporation of this Ag, was demonstrated. In contrast to mAb 26-5 and 26-20, mAb 8-2 showed extensive cross-reactivity with heterologous LPS preparations and heat-killed as well as live Gram-negative bacteria. It is concluded that each of the three mAb binds to a different antigenic epitope in lipid A and that exposure of those epitopes for antibody binding is restricted in a differential manner, depending on mode of Ag presentation. The here defined reaction patterns provide a basis for the interpretation of potential inhibitory effects on in vitro and in vivo biologic (and toxic) activities of endotoxins and Gram-negative bacteria.     

Preference for plants damaged by conspecific larvae in ovipositing cabbage root flies: influence of stimuli from leaf surface and roots

In laboratory dual-choice assays females of the cabbage root fly, Delia radicum, prefer for oviposition plants with roots damaged by conspecific larvae to undamaged controls. Cauliflower and kale plants were inoculated with root fly eggs (25 per plant) and the hatching larvae were allowed to feed on the roots for various periods of time (1–17 days). After 4 (cauliflower) or 5 (kale) days of larval feeding the oviposition preference was most pronounced and flies laid between 64% and 68% of their eggs near plants with damaged roots. Later, with increasing damage but fewer surviving, and thus actively feeding, larvae, the magnitude of the preference declined. The preference for plants already damaged by conspecific larvae may contribute to the previously observed aggregated distribution of D. radicum eggs in Brassica crop fields.Further experiments revealed that the sensory cues inducing this oviposition preference originate from the complex consisting of the damaged roots, the surrounding substrate (soil) and associated microbes, rather than from the aerial plant parts. In choice assays using the root-substrate complex of damaged and control plants (aerial parts removed), the observed preference for damaged roots was similar to that found for the entire plant but was more pronounced. The damaged roots alone, compared to control roots, received up to 72% (cauliflower) and 75% (kale) of the eggs. By contrast, surrogate leaves sprayed with methanolic leaf surface extracts from the most preferred plants which had been damaged were not discriminated from surrogate leaved sprayed with extracts of the respective control plants. Analysis of glucosinolate levels in methanolic leaf surface extracts revealed that root damage resulted in enhanced concentrations of indole-glucosinolates on the leaf surface in kale but not in cauliflower. Although indole-glucosinolates are oviposition stimulants for the cabbage root fly, the induced changes were apparently too small to influence oviposition behaviour.