Carbohydrate-binding proteins of tumor lines with different growth properties

Summary A tumor model system of clones of myeloproliferative sarcoma virus (MPV)-transformed rat fibroblasts (NRK) with different growth properties and metastatic potential was studied. The relationship between metastatic behavior and composition of carbohydrate-binding proteins (lectins) was analyzed by affinity chromatography. The metastatic variant differs qualitatively from its parental clone in the presence of galactoside-binding proteins at apparent molecular weights of 80 kDa, 70 kDa, 22 kDa, 18 kDa and 16 kDa and of a fucose-binding protein at apparent molecular weight of 42 kDa. The -glucosyl-binding proteins at apparent molecular weights of 67 kDa and 53 kDa and a galactoside-binding protein of apparent molecular weight of 34 kDa, however, are not detectable in the metastatic variant in comparison to its parental clone. In this respect the parental clone shows closer resemblance to the clone 5–8#1 with different growth properties and low metastatic potential than to its own metastatic variant. Furthermore, only the parental clone has a melibiose- and a mannan-binding protein of an apparent molecular weight of 64 kDa and 14 kDa, respectively. Rosette formation as model system for intercellular interaction reveals differences in the inhibition pattern with sugar between the two clones 5–8#1 and 5–20#20, whereas the metastatic variant 5–20#20 (s) exhibits drastically reduced capability to form rosettes. Initial experiments demonstrate the feasibility of drug targeting to transformed fibroblasts via carbohydrate-binding proteins.     

Structural studies of an acidic polysaccharide from the mucin secreted by Drosera capensis

The polysaccharide of the mucin secreted by the leaves of Drosera capensis is composed of l-arabinose, d-xylose, d-galactose, d-mannose, and d-glucuronic acid in the molar ratio of 3.6:1.0:4.9:8.4:8.2. For structural elucidation, methylation analysis using g.l.c. and g.l.c.-m.s. was performed on the native, the carboxyl-reduced, and the degraded polysaccharides. Partial hydrolysis, periodate oxidation, chromium trioxide oxidation, and uronic acid degradation were also performed on the native and carboxyl-reduced polysaccharides. Partial hydrolysis of the native and carboxyl-reduced polysaccharides gave various oligosaccharides that were characterized and suggest a structure containing a d-glucurono-d-mannan backbone having a repeating unit → 4)-β-d-GlcpA-(1 → 2)-α-d-Manp-(1 →. l-Arabinose and d-xylose are present as nonreducing furanosyl and pyranosyl end-groups, respectively, both attached to O-3 of d-glucuronic acid residues of the backbone. d-Galactose is present as non-reducing pyranosyl end-group linked to O-3 of d-mannose residues.     

Cloned nodulation genes of Rhizobium leguminosarum determine host-range specificity

Summary Three nodulation-deficient (nod) mutants of Rhizobium leguminosarum were isolated following insertion of the transposon Tn5 into pRL1JI, the R. leguminosarum plasmid known to carry the nodulation genes. DNA adjacent to the nod: Tn5 alleles was subcloned and used to probe a cosmid clone bank containing DNA from a Rhizobium strain carrying pRL1JI. Two cosmid clones which showed homology with the probe contained about 10 kb of DNA in common. The R. leguminosarum host-range determinants were found to be present within this 10 kb common region since either of the cosmid clones could enable a cured R. phaseoli strain to nodulate peas instead of Phaseolus beans, its normal host. Electron microscopy of nodules induced by Rhizobium strains cured of their normal symbiotic plasmid but containing either of the two cosmid clones showed bacteroid-forms surrounded by a peri-bacteroid membrane, indicating that normal infection had occurred. Thus it is clear that this 10 kb region of nodDNA carries the genes that determine host range and that relatively few bacterial genes may be involved in nodule and bacteroid development.     

On global stability of discrete population models

A necessary and sufficient condition for the global stability of a large class of discrete population models is provided which does not require the construction of a Liapunov function. The general result is applied to difference equations defined in terms of “two hump” functions and to an example of frequency dependent selection.     

ACTIVATION OF PIG BRAIN GLUTAMINASE

Pig brain glutaminase (EC 3.5.1.2, l -glutamine amidohydrolase) is activated by certain anions (e.g. phosphate, fluoride, carboxylic acids) and inhibited by others (e.g. chloride, bromide, iodide and glutamate). The only cation which has been found to activate the enzyme is the ammonium ion. This applies to both the tris-HCl form and the phosphate-borate form of glutaminase.     

Über bau und funktion der prosoma-drüsen von spinnmilben (Tetranychidae,Trombidiformes)

Zoomorphology - Die licht- und elektronenmikroskopische Untersuchung der Prosomadrüsen der Spinnmilben Bryobia praetiosa, Bryobia rubrioculus und Tetranychus urticae (Tetranychidae,...     

Lineare Systeme mit gesteuerten statistischen Impulsquellen

Summary From the communication engineers point of view the paper deals with networks consisting of linear filters and a special sort of controlled statistical pulse generators (SIG). The SIG responds to an analog signal with a sequence of Dirac impulses, where the probability for an output impulse at a given time depends on the instantaneous value of the input signal only. In connection with linear filters, however, systems can be realized in which the whole past of the input determines the statistical structure of the output. Therefore systems consisting of linear filters and SIGs (SIG networks) become interesting as models of biological systems, because in biological information processing transformations from analog signals into pulse trains occur very often. An example concerning the application of SIG systems in behavioural sciences will be discussed in a subsequent paper. In the present paper a theoretical analysis of the SIG and SIG networks is carried out by means of Statistical Communication Theory and Theory of Stochastic Processes. It is shown that under certain conditions very complex SIG networks can be treated with Correlation Theory. For one case not satisfying these conditions a solution on the base of Markoff processes is given.

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Auszug aus einer von der Fakultät für Maschinenwesen und Elektrotechnik der Technischen Hochschule München genehmigten Dissertation.Herrn Prof. Dr.-Ing. H. Marko danke ich für das Interesse und die fördernde Kritik während des Entstehens der dieser Arbeit zugrundeliegenden Dissertation. Der Deutschen Forschungsgemeinschaft ist für die finanzielle Förderung der Untersuchungen zu danken. Die numerischen Berechnungen wurden auf der Rechenanlage TR4 des Leibniz-Rechenzentrums der Bayerischen Akademie der Wissenschaften durchgeführt.     

Ascendente Handschwingen-Mauser beiMuscicapa striata

Zusammenfassung Ascendente Mauser der Handschwingen beiMuscicapa striata wird beschrieben. Der Ersatz der Handschwingen von der äußeren zur inneren fortschreitend ist einzigartig bei den Passeres. Bisher war von allen untersuchten Passeres nur die descendente, von innen nach außen fortschreitende Mauser der Handschwingen bekannt. Auch die nächstverwandten ArtenMuscicapa gambagae, M. sibirica undM. latirostris mausern descendent. Vermutlich verlaufen auch die Mauser der Armschwingen und der Schwanzfedern beiM. striata nach einem anderen Schema als bei den übrigen Passeres. Die mögliche Bedeutung der Erscheinung wird diskutiert.

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Summary The examination of eight specimens of the palearctic FlycatcherMuscicapa striata collected in the wintering grounds in Tanganyika Territory and Kenya Colony, all in different stages of complete prenuptial moult, yielded the unexpected result of ascending primary moult (beginning with the outermost primary), in contrast to the descending mode so far known to be followed by all Passeriformes.With regard to the moult of secondaries and tail-feathers the material, somewhat scanty in this respect, seems to show that in both these feather-tracts too the ordinary Passerine sequence is reversed, the rectrices being moulted centripetally and the secondaries diverging from a single moult centre represented by the sixth, but this needs corroboration.A superficial search among other members of the genusMuscicapa, includingM. gambagae, and among other genera of Flycatchers disclosed the usual descending primary moult in all these forms (listed in the text).A possible functional meaning of the ascending primary moult inMuscicapa striata is discussed.