Identification and Characterization of Epithelial Cells in Mammalian Tissues by Immunofluorescence Microscopy Using Antibodies to Prekeratin

The occurrence of intermediate-sized filaments containing prekeratin-like proteins ('cytokeratins') has been examined in various organs of rat and cow by electron microscopy and by immunofluorescence microscopy on frozen sections using antibodies to defined constitutive proteins of various types of intermediate-sized filaments (prekeratin, vimentin, desmin). Positive cytokeratin reaction and tonofilament-like structures have been observed in the following epithelia: epidermis; ductal, secretory, and myoepithelial cells of sweat glands; mammary gland duct; myoepithelial cells of lactating mammary gland; milk secreting cells of cow; ductal, secretory, and myoepithelial cells of various salivary glands; tongue mucosa; bile duct; excretory duct of pancreas; intestinal mucosa; urothelium; trachea; bronchi; thymus reticulum, including Hassall corpuscles; mesothelium; uterus; and ciliated cells of oviduct. None of the epithelial cells mentioned has shown significant reaction with antibodies to vimentin, the major component of the type of intermediate-sized filaments predominant in mesenchymal cells. The widespread, if not general occurrence of cytokeratin filaments in epithelial cells is emphasized, and it is proposed to use this specific structure as a criterion for true epithelial character or origin.     

VORZUGSTEMPERATUR UND VORZUGSLUFTFEUCHTIGKEIT DER BEIDEN SCHABENARTEN PERIPLANET A AMERICANA UND BLABERUS TRAPEZOIDEUS (INSECTA: BLATTARIA)

Von adulten Männchen der beiden Schabenarten Periplaneta americana und Blaberus trapezoideus wurden gleichzeitig Vorzugstemperatur und Vorzugsluftfeuchtigkeit ermittelt. Für beide Arten konnten in ihren Vorzugstemperaturen gewisse Akklimatisationserscheinungen festgestellt werden. Bei P. americana steigt die Vorzugstemperatur von 26°–29° nach einem einmonatigen Aufenthalt bei 20° auf etwa 29°— 30° nach einerer Exposition bei 35° an. B. trapezoideus hat eine um etwa 3° niedrigere Vorzugstemperatur. Nach einem Aufenthalt bei 20° beträgt sie etwa 23°–26°. Sie steigt auf etwa 26° nach einer Exposition bei 32° an. P. americana bevorzugt stets ein trockenes Milieu (geboten wurden 18% r.L.), B. trapezoideus sucht höhere Luftfeuchtigkeit auf (45%–93% r.L.) und meidet trockenes Milieu. Ein Gewichtsverlust von 15%–18% veranlaßt P. americana eine um 1°–3° niedrigere Vorzugstemperatur, aber vor allem eine sehr hohe Luftfeuchte aufzusuchen. Ein Gewichtsverlust von 20%–25% des Körpergewichtes hat keinen Einfluß auf die Vorzugstemperatur von B. trapezoideus; jedoch halten sich die Tiere nur ebenfalls länger in sehr hoher Luftfeuchte auf.     

中国淡脉隧蜂属指名亚属三新种(膜翅目:蜜蜂总科, 隧蜂科)

本文记述中国淡脉隧蜂属指名亚属Lasioglossum(Lasioglossum)三新种。所有正模、配模和大多数副模标本保存于中国科学院动物研究所,少量副模标本保存于奥地利国P. Andreas Werner Ebmer处。     

The Role of Malate, Oxalate, and Mustard Oil Glucosides in the Evolution of Zinc-Resistance in Herbage Plants

Malate, oxalate and mustard oils were analysed in zinc-resistant and zinc-sensitive ecotypes of Silene cucubalus Wib., Rumex acetosa L., Thlaspi alpestre L. and Agrostis tenuis Sibth. The effect of zinc on the activities of carbonic anhydrase and peroxidase in Siiene cucubalus was tested. Carbonic anhydrase of the zinc-resistant ecotypes was stimulated by addition in vivo of high amounts of zinc. The high activity of peroxidase in the non-zinc-resistant ecotypes after the addition of zinc documented a poisoning of the sensitive plants by zinc. The amount of oxalate differed greatly between ecotypes. There was, however, no direct correlation between zinc-resistance and oxalate. When applying zinc to the nutrient medium, the synthesis of oxalate was inhibited in zinc-sensitive, but stimulated in zinc-resistant ecotypes of Silene cucubalus and Rumex acetosa. In Thlaspi alpestre high concentrations of mustard oil glucosides were found. Zinc-resistant plants produced twice as much glucosides as sensitive ones. A possible role of mustard oils in zinc-resistance is discussed. In the content of malate there were great quantitative differences between zinc-resistant and zinc-sensitive plants. All zinc-resistant ecotypes of all the species contained much higher concentrations in their green organs than the sensitive ones. It is assumed that malate is a major factor in the evolution of zinc-resistance. Malate may act as a complexing agent for zinc within the plasma, whereas oxalate and mustard oils may function as “terminal acceptors” of large amounts of zinc. The role of malate may be extended by a special transport mechanism, by which zinc is eliminated from the plasma into the vacuole.