3. Hans A. Froebe: Der Sproßaufbau von Hydrocotyle vulgaris L.

Das Ziel der Arbeit ist, den komplizierten Sproßaufbau von Hydrocotyle vulgaris morphologisch aufzuklären. Entgegen der herrschenden Auffassung ist deren Hauptachse orthotrop, also nicht am plagiotropen Wuchs des Vegetationskörpers beteiligt. Allerdings endet sie bereits nach Ausgliederung von nur vier Blattorganen (zwei Primärblättern und zwei Folgeblättern) in einer äußerst hinfälligen Hauptinfloreszenz. Für die ganze Pflanze hat dieser Primärsproß nur transitorische Bedeutung, denn die Seiten- und Beisprosse aus der Achsel der beiden Folgeblätter sind es, die den bekannten prostraten Vegetationskörper erst aufbauen. Hierbei handelt es sich vergleichend-morphologisch gesehen um ein exremes Beispiel anthokladischer Kriechtriebe, für deren Verselbständigung das Radikationsvermögen der Knoten von entscheidender Bedeutung ist. Außerdem sind sie befähigt, an ihren distalen Enden stets wieder zur vegetativ-monopodialen Wuchsweise zurückzukehren. Ihre Seitenachsen zweiter Ordnung erscheinen entweder als Langtriebe, Übergangstriebe oder aber als monochasiale, reproduktiv tätige Kurztriebe, die sich in Abhängigkeit von den spezifischen Standortsverhältnissen ebenfalls wieder vegetativ-monopodial fortsetzen können. Auf diesen Erkenntnissen fußend, wird versucht, ein Schema des gesamten Sproßsystems zu entwerfen. Da es sich bei H. vulgaris um den Prototyp der prostrat wachsenden Hydrocotyle-Arten überhaupt handelt, kann vermutet werden, daß das gegebene Schema nicht nur für die hier behandelte Hydrocotyle vulgaris, sondern im Prinzip auch für viele andere Arten der Gattung, soweit sie prostraten Wuchs aufweisen, Geltung hat.     

Anti‐cancer therapy with TNFα and IFNγ: A comprehensive review

Tumour necrosis factor alpha (TNFα) and interferon gamma (IFNγ) were originally found to be produced by inflammatory cells and play important roles in the immune system and surveillance of tumour growth. By activating distinct signalling pathways of nuclear factor‐κB (NF‐κB), mitogen‐activated protein kinase (MAPK), and JAK/STAT, TNFα and IFNγ were reported to effectively trigger cell death and perform powerful anti‐cancer effects. In this review, we will discuss the new advancements of TNFα and IFNγ in anti‐cancer therapy.     

Characterization of calf-ovary adenosine;3':5'-monophosphate-dependent protein kinases and adenosine-3':5'-monophosphate-binding proteins.

Protein phosphokinase activity from the calf ovary cytosol (105000 X g supernatant fraction) has been resolved by chromatography and polyacrylamide gel electrophoresis into two major protein kinases, PK-H1 and PK-H2, both dependent on adenosine 3':5'-monophosphate (cyclic AMP). The enzymes have similar molecular weights (230000) and substrate specificities but differ in their cyclic-AMP-dependency and stimulation by cyclic AMP. The differences have been explained by the presence in PK-H1 of a unique cyclic-AMP-binding protein which has little catalytic activity associated with it. The cyclic-AMP-binding protein has a high affinity for cyclic AMP and in addition is able to inhibit the activity of the isolated catalytic subunit. The ovarian cyclic-AMP-dependent protein kinases have properties similar to those found in other tissues. They can be dissociated into catalytic and regulatory subunits and are inhibited by a heat-stable protein inhibitor isolated from rabbit skeletal muscle. Preincubation of the cytosol with high levels of cyclic AMP resulted in additional cyclic-AMP-dependent protein kinases and cyclic-AMP-binding proteins which include protein kinases and binding proteins of greater than 400 000 molecular weight.     

TGF-β3 and cancer: A review

With the development of growth factors and growth factor modulators as therapeutics for a range of disorders, it is prudent to consider whether modulating the growth factor profile in a tissue can influence tumour initiation or progression. As recombinant human TGF-β3 (avotermin) is being developed for the improvement of scarring in the skin it is important to understand the role, if any, of this cytokine in tumour progression.Elevated levels of TGF-β3 expression detected in late-stage tumours have linked this cytokine with tumourigenesis, although functional data to support a causative role are lacking. While it has proved tempting for researchers to interpret a ‘correlation’ as a ‘cause’ of disease, what has often been overlooked is the normal biological role of TGF-β3 in processes that are often subverted in tumourigenesis. Clarifying the role of this cytokine is complicated by inappropriate extrapolation of the data relating to TGF-β1 in tumourigenesis, despite marked differences in biology between the TGF-β isoforms. Indeed, published studies have indicated that TGF-β3 may actually play a protective role against tumourigenesis in a range of tissues including the skin, breast, oral and gastric mucosa. Based on currently available data it is reasonable to hypothesize that administration of acute low doses of exogenous TGF-β3 is unlikely to influence tumour initiation or progression.     

Solution properties of γ‐crystallins: Hydration of fish and mammal γ‐crystallins

Lens γ crystallins are found at the highest protein concentration of any tissue, ranging from 300 mg/mL in some mammals to over 1000 mg/mL in fish. Such high concentrations are necessary for the refraction of light, but impose extreme requirements for protein stability and solubility. γ‐crystallins, small stable monomeric proteins, are particularly associated with the lowest hydration regions of the lens. Here, we examine the solvation of selected γ‐crystallins from mammals (human γD and mouse γS) and fish (zebrafish γM2b and γM7). The thermodynamic water binding coefficient B₁ could be probed by sucrose expulsion, and the hydrodynamic hydration shell of tightly bound water was probed by translational diffusion and structure‐based hydrodynamic boundary element modeling. While the amount of tightly bound water of human γD was consistent with that of average proteins, the water binding of mouse γS was found to be relatively low. γM2b and γM7 crystallins were found to exhibit extremely low degrees hydration, consistent with their role in the fish lens. γM crystallins have a very high methionine content, in some species up to 15%. Structure‐based modeling of hydration in γM7 crystallin suggests low hydration is associated with the large number of surface methionine residues, likely in adaptation to the extremely high concentration and low hydration environment in fish lenses. Overall, the degree of hydration appears to balance stability and tissue density requirements required to produce and maintain the optical properties of the lens in different vertebrate species.     

Helix–coil transition in copolypeptides. II. Poly(γ-benzyl L-glutamate-co-ε-carbobenzoxy-L-lysine)

The thermal helix–coil transition of poly(γ-benzyl L -glutamate-co-ε-carbobenzoxy-L -lysine) copolypeptides was studied in solvent mixtures of different compositions. The cooperativity parameter v changes linearly with polymer (and solvent) composition, whereas the heat of the transition shows a very pronounced minimum as a function of polymer composition. This minimum cannot be due only or mainly to the solvent changes and must be attributed to the effect on the transition of the side chains of the polypeptides.