Vasoconstriction: a novel activity for low density lipoprotein

Low density lipoprotein plays an important role in the pathogenesis of atherosclerosis. Cumulative addition of 1-30 micrograms/ml of LDL from normolipidemic subjects produced a dose-dependent increase in contractile tension of thoracic aortic rings from rats. The maximal LDL-induced contractile response was approximately 30% of that induced by 1 microM norepinephrine. Similar concentrations of LDL induced a dose-dependent transient increase of the concentration of intracellular free calcium, and a biphasic change of the intracellular pH in cultured rat vascular smooth muscle cells. We conclude that low density lipoprotein occurring for example in the extravascular fluid can mediate vasoconstriction by changes in cytosolic calcium and intracellular pH.     

Class III β-tubulin,a novel biomarker in the human melanocyte lineage

It is generally thought that class III β-tubulin expression is limited to cells of the neural lineage and is therefore often used to identify neurons amongst other cell types, both in vivo and in vitro. Melanocytes are derived from the neural crest and share both morphological features and functional characteristics with peripheral neurons. Here, we show that these similarities extend to class III β-tubulin (TUBB3) expression, and that human melanocytes express this protein both in vivo and in vitro. In addition, we studied the expression of class III β-tubulin in two murine melanogenic cell lines and show that expression of this protein starts as melanoblasts mature into melanocytes. Melanin bleaching experiments revealed close proximity between melanin and TUBB3 proteins. In vitro stimulation of primary human melanocytes by α-MSH indicated separate regulatory mechanisms for melanogenesis and to TUBB3 expression. Together, these observations imply that human melanocytes express TUBB3 and that this protein should be recognized as a wider marker for multiple neural crest-derived cells.     

Der Nahrungserwerb von Bufo calamito Laurenti

Ohne ZusammenfassungDie vorliegende Arbeit, wurde unternommen auf Anraten des Herrn Dr. J. Verwey, welchem ich für seine Hilfe zu besonderem Dank verpflichtet bin.     

3-Nitrobenzenesulfonate, 3-Aminobenzenesulfonate, and 4-Aminobenzenesulfonate as Sole Carbon Sources for Bacteria

Aerobic, carbon-limited, enrichment cultures containing 3-aminobenzenesulfonate or 3-nitrobenzenesulfonate as the sole source of carbon and energy yielded growth and complete substrate disappearance. Pure cultures of putative pseudomonads were isolated which utilized these compounds quantitatively. Degradation was compared with that of 2- and 4-aminobenzenesulfonate.     

Effect of insecticides,acaricides and fungicides onMormoniella vitripennis walker (Hym. Pteromalidae)

Zusammenfassung In Versuchen über die Anf?lligkeit von Schlupfwespen für Bek?mpfungsmittel wurdeMormoniella vitripennis benutzt. Eine Spritzbelagmethode wurde angewandt. Die Ergebnisse in Tabellen I, II und III zeigen eine sehr geringe Giftwirkung von Captan, Karathane, Thiram und die Sauerstoffanalogon von Eradex, dagegen gaben Thiodan und Sevin eine sehr hohe Mortalit?t. Ryanicide, Chlorbenside und Isolan waren in den angewandten Konzentrationen nicht gef?hrlich für diesen Parasit.      

On-line measurement in biotechnology: techniques.

Bioprocesses are generally ill controlled. This is due to the fact that the measurement of relevant variables is difficult. Therefore, fundamental knowledge of metabolic interrelations is, at least in vivo, limited. In this article, some of the most important measurement techniques are reviewed in order to provide an evaluation of their current state. Emphasis is given to the underlying principles and on-line capability which allow to judge their importance and potential for exploitation resulting in well (maybe entirely) controlled bioprocesses in the future.