Continuous registration of the pancreatic blood flow after intravenous application of glucose

Zusammenfassung Die Hyperglykämie nach einmaliger stossartiger Glukoseinjektion bewirkt einen Durchblutungsanstieg der Bauchspeicheldrüse. Dieser wurde kontinuierlich mit einem elektromagnetischen Blutstrommesser bei narkotisierten Hunden registriet. Der Anstieg setzt sich aus 2 Abschnitten zusammen, wovon der erste unspezifisch auch in der A. femoralis auftritt.     

Inhibition de la cancérogenèse spontanée chez les souris R III et AkR par des implants de tissus cancéreux modifiés

Summary (1) After a 24-h passage in a rabbit, fragments of spontaneous isologous mammary carcinoma were implanted under the skin of young R III females. This procedure was found to prevent the appearance of spontaneous mammary tumours in a high percentage of these animals. The subsequent appearance of carcinoma was to be observed in only 23% of treated animals as compared with 51% in controls.(2) After a 24-h passage in a rabbit, fragments of leukotic isologous tissue, implanted subcutaneously in young AkR females, reduced subsequent spontaneous leukomogenesis from 85 to 38%.     

Über die hemmung des wachstums vonLactobacillus casei durch einige antiphlogistica

Summary A new method for the classification of antiphlogistics is described using the growth inhibition ofLactobacillus casei. In this test the fenamic acids and particularly the new class of the Cinnopentazon-antiphologistics (Scha 306, Scha 764 etc.) exhibit bacteriostatic properties of a medium intensity.

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Alexander von Muralt zum 65. Geburtstag gewidmet.     

The bacterial SoxAX cytochromes

SoxAX cytochromes are heme-thiolate proteins that play a key role in bacterial thiosulfate oxidation, where they initiate the reaction cycle of a multi-enzyme complex by catalyzing the attachment of sulfur substrates such as thiosulfate to a conserved cysteine present in a carrier protein. SoxAX proteins have a wide phylogenetic distribution and form a family with at least three distinct types of SoxAX protein. The types of SoxAX cytochromes differ in terms of the number of heme groups present in the proteins (there are diheme and triheme versions) as well as in their subunit structure. While two of the SoxAX protein types are heterodimers, the third group contains an additional subunit, SoxK, that stabilizes the complex of the SoxA and SoxX proteins. Crystal structures are available for representatives of the two heterodimeric SoxAX protein types and both of these have shown that the cysteine ligand to the SoxA active site heme carries a modification to a cysteine persulfide that implicates this ligand in catalysis. EPR studies of SoxAX proteins have also revealed a high complexity of heme dependent signals associated with this active site heme; however, the exact mechanism of catalysis is still unclear at present, as is the exact number and types of redox centres involved in the reaction.     

Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype

Tetraodon nigroviridis is a freshwater puffer fish with the smallest known vertebrate genome. Here, we report a draft genome sequence with long-range linkage and substantial anchoring to the 21 Tetraodon chromosomes. Genome analysis provides a greatly improved fish gene catalogue, including identifying key genes previously thought to be absent in fish. Comparison with other vertebrates and a urochordate indicates that fish proteins have diverged markedly faster than their mammalian homologues. Comparison with the human genome suggests approximately 900 previously unannotated human genes. Analysis of the Tetraodon and human genomes shows that whole-genome duplication occurred in the teleost fish lineage, subsequent to its divergence from mammals. The analysis also makes it possible to infer the basic structure of the ancestral bony vertebrate genome, which was composed of 12 chromosomes, and to reconstruct much of the evolutionary history of ancient and recent chromosome rearrangements leading to the modern human karyotype.     

Chromatin dynamics during epigenetic reprogramming in the mouse germ line

A unique feature of the germ cell lineage is the generation of totipotency. A critical event in this context is DNA demethylation and the erasure of parental imprints in mouse primordial germ cells (PGCs) on embryonic day 11.5 (E11.5) after they enter into the developing gonads. Little is yet known about the mechanism involved, except that it is apparently an active process. We have examined the associated changes in the chromatin to gain further insights into this reprogramming event. Here we show that the chromatin changes occur in two steps. The first changes in nascent PGCs at E8.5 establish a distinctive chromatin signature that is reminiscent of pluripotency. Next, when PGCs are residing in the gonads, major changes occur in nuclear architecture accompanied by an extensive erasure of several histone modifications and exchange of histone variants. Furthermore, the histone chaperones HIRA and NAP-1 (NAP111), which are implicated in histone exchange, accumulate in PGC nuclei undergoing reprogramming. We therefore suggest that the mechanism of histone replacement is critical for these chromatin rearrangements to occur. The marked chromatin changes are intimately linked with genome-wide DNA demethylation. On the basis of the timing of the observed events, we propose that if DNA demethylation entails a DNA repair-based mechanism, the evident histone replacement would represent a repair-induced response event rather than being a prerequisite.