Developmental changes in the distribution of cecal lectin-binding sites of Balb-c mice.

The existence of lectin-binding sites was investigated in the cecum of Balb-c mice at seven developmental stages ranging from 18 days post conception (p.c.) to 8 weeks after birth. Nine horseradish-peroxidase-conjugated lectins (concanavalin A, Triticum vulgaris, Dolichus biflorus, Helix pomatia, Arachis hypogaea, Glycine maximus, Lotus tetragonolobus, Ulex europaeus, Limulus polyphemus) were applied to 5- to 7-microns thin paraffin sections of Bouin-fixed tissue. After DAB staining the sections were evaluated by light microscopy. It was shown that each lectin exhibits a unique developmental pattern. The adult binding patterns were established at the age of 3-4 weeks with only minor changes occurring thereafter. Considerable differences in binding patterns occurred not only between lectins of different groups but also between lectins with the same nominal monosaccharide specificity.     

The cell coat of the olfactory epithelium proper and vomeronasal neuroepithelium of the rat as revealed by means of the Ruthenium-red reaction

Summary The apical cell coat of the olfactory epithelium proper and the vomeronasal neuroepithelium of the rat was investigated electronmicroscopically by means of the Ruthenium-red reaction. In the olfactory epithelium proper, the cilia of receptor cells and microvilli of supporting cells possess a cell coat measuring approximately 10 nm in thickness. In the vomeronasal neuroepithelium, the apical cell coat is thicker than in the olfactory epithelium proper. On microvilli of vomeronasal receptor cells the cell coat varies in thickness from 15 to 20 nm, and on microvilli of supporting cells it measures approximately 75 nm. The functional implications of these findings are discussed.A portion of this study was presented at the 6^th European Anatomical Congress in Hamburg. This publication is dedicated to Prof. E. KlikaSupported by the Deutsche Forschungsgemeinschaft (Br 358/5-1).     

Identification of endogenous sugar-binding proteins in the accessory sex glands of NMRI mice. A histochemical and biochemical study

In the present study we report on the histotopographical distribution of carbohydrate-binding proteins in the prostate and seminal vesicle of sexually mature NMRI mice using a panel of fluorescein-isothiocyanate labelled neoglycoproteins and asialoglycoproteins. Additionally, biochemical analysis using affinity chromatography and SDS-gel electrophoresis was performed to purify and characterize the respective proteins from the tissue. Our histochemical results clearly demonstrate the presence of endogenous receptors for the carbohydrate part of glycoconjugates in both glands. In the prostate a distinct staining was seen after incubation with melibiose-BSA-FTC, glucuronic acid-BSA-FTC and asialofetuin-FTC (only in the ventral prostate). In the epithelium of the seminal vesicle a weak staining occurred after incubation with asialofetuin-FTC and maltose-FTC. In the stroma of both accessory sex glands a distinct binding of several (neo)glycoproteins specific for beta-galactoside-binding proteins was observed which could be attributed to a beta-galactoside-binding lectin. Indeed biochemical analysis ascertained presence of such a histochemically detectable activity. We assume that the carbohydrate-binding proteins of the stroma, which were obviously linked to the elastic fibers, could play a role in the organisation of the extracellular matrix in the interstitium of the glands.     

Rastermikroskopische Untersuchungen der olfaktorischen Rezeptoren im Riechepithel des Goldfisches (Carassius auratus)

Zusammenfassung Durch rastermikroskopische Untersuchungen lassen sich mehrere, morphologisch unterschiedliche Rezeptoren in der Regio olfactoria des Goldfisches (Carassius auratus) unterscheiden. Dabei muß vorläufig offen bleiben, ob den morphologischen Varianten entsprechende funktionelle Unterschiede zuzuordnen sind. Auf den Lamellen der Riechrosette sind Sinneszellareale und in ihnen Flimmerzellgruppierungen zu beobachten. Die wechselnde Dichte der verschiedenen Rezeptoren in einzelnen Sinneszellarealen wird betont. Die Befunde werden zu Riechtheorien und zu der Frage in Beziehung gesetzt, ob es eine räumliche Zuordnung von Zonen des Riechepithels zu bestimmten Anteilen des Bulbus olfactorius gibt.

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Scanning electron microscopy of olfactory receptors in Carassius auratus

Summary Investigations by scanning electron microscopy demonstrate the existence of several morphologically different types of olfactory receptors in Carassius auratus. The structural differences, however, do not allow a definite classification of sensory cells into functionally different elements. The olfactory organ has a central axis with lamellae emerging at both sides of it. On these lamellae sensory areas with densely packed receptor cells and with groups of ciliated cells exist. The terminals of the receptor cells show a great polymorphism of their surface. The morphologically different receptor cells are not equally distributed over the olfactory organ but differ from each other in quantity and density. The morphological results are discussed in relation to olfactory theories and in relation to the question whether there are topographical projections between the peripheral olfactory organ and the Bulbus olfactorius.

Die Verfasser danken Herrn Karl Donberg für sorgfältige technische Assistenz.     

Elektronenmikroskopische und histoautoradiographische Befunde zur Puromycinwirkung auf ausreifende Plexus chorioideus-Zellen in vitro

Zusammenfassung Der Einfluß von Puromycin auf die Inkorporierung von Leucin-³H wird an kultivierten Plexus chorioideus-Zellen 9 Tage alter Hühnerembryonen untersucht. Die Kulturen zeigen unter Einwirkung von Puromycin eine deutliche Hemmung der Aufnahme von Leucin-³H. Die Aufnahme der markierten Substanz ins Cytoplasma wird im Vergleich zu Kontrolluntersuchungen prozentual mehr gehemmt als die Aufnahme des Leucins in den Kern.Unmittelbar nach dem Zusatz von Puromycin zum Nährmedium treten in den kultivierten Plexus chorioideus-Zellen Ansammlungen von multivesicular bodies und z. T. auch zahlreiche Lysosomen auf. Beide Organellen verschwinden im Verlauf der weiteren Kultivierung wieder fast vollständig aus den Zellen.Eine neuerliche Zugabe von markiertem Leucin nach der Puromycingabe zeigt, daß die beobachteten Wirkungen reversibel sind und daß die Puromycinwirkung nicht länger anhält, als diese Substanz im Nährmedium vorhanden ist.

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On the influence of puromycin on embryonic choroid plexus cells in vitro. An electronmicroscopic and histoautoradiographic study

Summary The influence of puromycin on the incorporation of leucin-³H into cells of choroid plexus of nine day old chicken embryos is studied.Puromycin causes a strong inhibition of the incorporation of leucin-³H into the cultures. Compared with controls, the inhibition of the uptake of the labelled substance is more pronounced in the cytoplasm than in the nucleus.Immediately after puromycin is added to the tissue culture medium an accumulation of multivesicular bodies and—to a certain degree—of lysosomes appears in the cells of the choroid plexus. Both organells disappear almost completely during the cultivation period.A second incubation with labelled leucin after puromycin shows that the observed effects are reversible and that puromycin acts only as long as it is present in the culture medium.The embryonic cells of choroid plexus develop normally even though treated with puromycin.

Die unreifen Plexus chorioideus-zellen entwickeln sich trotz der Puromycingaben normal.Das morphologische Differenzierungsergebnis wird nicht verändert.     

Das Verhalten trypsinierter Plexus-chorioideus-Zellen in Gewebekulturen

Zusammenfassung Die Plexus chorioidei der Seitenventrikel 10 Tage alter Hühnerembryonen wurden trypsiniert, kultiviert und anschließend licht- und elektronenmikroskopisch untersucht. Unmittelbar nach der Trypsinierung sind die Plexuszellen bei der Kultivation in flüßigen Medium als Einzelzellen anzutreffen. Nach 12stündiger Kulturzeit sieht man kleine Rosetten, deren Größe bis zum Alter von 36 Std noch zunimmt. Die isolierten Zellen und die Zellen der Rosetten weisen eine rege Zilientätigkeit auf, durch die sie in lebhafter Bewegung gehalten werden.Mit der Zusammenlagerung der isolierten Zellen zu Gewebsverbänden geht gleichzeitig eine feinstrukturelle Differenzierung einher. Es treten Desmosomen, ein basales Labyrinth, eine Basalmembran und oft ein Ergastoplasma auf.

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Trypsinized cells of the plexus chorioideus in tissue cultures

Summary Plexus cells of 10 days old chicken embryos were trypsinized. After various periods of culturing the material was studied both light- and electronmicroscopically. Directly after dissociation most of the plexus cells are found to be separated from each other in the liquid medium. However after 12 hours of culturing the individual cells reaggregate themselves in small rosettes which enlarge until the stages of 36 hours. Simultaneously the aggregational process of previously dissociated cells is combined with an ultrastructural differentiation and desmosomes, basal labyrinth, basement membrane and ergastoplasm are formed.Both the isolated cells and the rosettes exhibit quick rotational movements due to their ciliar action.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (Me 276/5).     

Ultrastructural alterations in differentiating choroid plexus cells by puromycin

This study centres on the effect of puromycin, applied in various concentrations, on the differentiation of choroid plexus cells in tissue cultures. Puromycin added to these cultures in doses of 25, 50 and 100 μg/ml medium merely produced reversible cell changes when present for 2 h. After 3 h, choroid plexus cells react to continuous feeding with puromycin in a dose of 100μg/ml with an almost total loss of the membrane system of the endoplasmic reticulum. At this time many of the free ribosomes have disappeared. The results of this study suggest a continuous renewal of the membrane-structure of the endoplasmic reticulum.     

Increased DNA breaks and up-regulation of both G1 and G2 checkpoint genes p21WAF1/CIP1 and 14-3-3 σ in circulating leukocytes of glaucoma patients and vasospastic individuals

Summary. Objective: Vascular disorder leading to local ischemia/reperfusion has been shown to play an important role in the glaucomatous damage. A decreased expression level of XPGC-gene has been found in circulating leukocytes of normal-tension glaucoma patients. Although decreased activity of XPGC-gene leads to insufficient DNA-repair, no leukopenia has been observed in glaucoma. Molecular mechanisms ensuring cell survival have not been elucidated yet for glaucoma with vascular disorder.Material and methods: Using the ex vivo optical imaging method of alkaline comet assay comparative quantification of DNA breaks was performed in circulating leukocytes of non-glaucomatous non-vasospastic and vasospastic individuals as well as both normal-tension and high-tension glaucoma patients. Relative expression levels of the anti-apoptotic factors P21^WAF1/CIP1 and 14-3-3 were investigated in all groups tested.Results and conclusions: The quantification of P21^WAF1/CIP1 showed the highest expression rates in high-tension glaucoma patients which were significantly higher than those in all other groups tested. The highest expression rates of 14-3-3 were found in both groups of glaucoma patients. These expression levels correlated well with DNA breaks measured. Since the expression of P21^WAF1/CIP1 in leukocytes was shown to be crucial for their survival under stress conditions, we suppose further that the up-regulation of this gene is the key event in the survival mechanisms of leukocytes in glaucoma accompanied with vascular disorder. The p21^WAF1/CIP1 gene should be further taken into consideration as a potential marker, the up-regulation of which in circulating leukocytes of vasospastic individuals may indicate an increased risk for the developing glaucoma.     

Intraepithelial blood vessels in the vomeronasal neuroepithelium of the rat

Summary Epithelial-vascular relationships are established during the development of the vomeronasal neuroepithelium of the rat. Special attention is given to the fine structure of the endothelial wall of intra-epithelial vessels, to ultrastructural aspects of the neuronal-vascular relationships, and to the appearance of inclusion bodies in the neuronal cells adjacent to these vessels. The neuronal perikarya surrounding the blood vessels are filled with highly developed smooth endoplasmic reticulum. Possible functional implications of the vascularization of the neuroepithelium of the vomeronasal organ in mediating olfacto-endocrine relationships are discussed. It is suggested that the intra-epithelial blood vessels are at least supportive and nutritive in nature, while their implication in an olfacto-endocrine connection remains obscure.On sabattical leave: Visiting Professor, Department of Anatomy, University of Kentucky, Lexington, Ky., USA