Effects ofβ-internal (P32) irradiation on the 5-HT content of CNS levels

Zusammenfassung Die interne-Bestrahlung in kleinen Dosen vergrössert den 5-Hydroxytryptamin-Inhalt des zentralen Nervensystems der Ratte: Gehirnrinde, Dyencephalus, Hypothalamus, Geruchbulbe, Mittelhirn und Rückenmark. Bei Experimenten mit höheren Dosen (über 500 rad) sinkt der 5-Hydroxytryptamin-Gehalt.

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This work has been carried out under a grant from the International Atomic Energy Agency, Vienna; contract No. 95 RB/1-RB/2.     

Mechanisms of sympathetic regulation of arterial smooth muscle

Zusammenfassung Der Wirkungsbereich der Querschnittsregulation der A. dorsalis pedis durch den Sympathikus bei Hunden wurde erfasst und die Relation Reizerfolg-Reizfrequenz durch eine Hyperbel charakterisiert. Mittels Fluoreszenzmethode gewonnene Befunde weisen darauf hin, dass die durch Sympathikusreizung freigesetzen Monoamine zu den nervenfreien Mediaschichten diffundieren.

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For the supply of Nialamide we are indebted to Pfizer Corporation, Eastern Europe Division.     

Variation in the specific activity of intestinal DNA in Alytes obstetricians larvae (Amphibia, Anura) treated with thyroxine]

Treatment by thyroxine modified the specific activity of intestianl DNA in premetamorphic Alytes tadpoles. The activity decreased up to the 3rd day, and showed afterwards a peak which culminates on the 9th day. These results have been discussed in comparison with previous radioautographic observations.     

Triploidy in callus culture ofVicia faba L. investigated by the Giemsa C-banding technique

Summary Callus tissue ofVicia faba has been grown from explants of immature embryos. The karyological analysis by the Giemsa C-banding technique has shown triploid and tri-aneuploid mitoses, all with an extra chromosome and with structurally altered karyotypes. Estimates of the amounts of interphase heterochromatin (chromocentres) indicate endopolyploidy up to 12 n.This work was financially supported by the Research Council of the S.R. Croatia — SIZIV. The authors wish to express their gratitude to the Industroprojekt Zagreb for the use of the image analyser, to Mr M. Denih for the area determinations of drawings, and to Dr D. Schweizer, Vienna, for critical comments.     

Myosin IXB variant increases the risk of celiac disease and points toward a primary intestinal barrier defect

Celiac disease is probably the best-understood immune-related disorder. The disease presents in the small intestine and results from the interplay between multiple genes and gluten, the triggering environmental factor. Although HLA class II genes explain 40% of the heritable risk, non-HLA genes accounting for most of the familial clustering have not yet been identified. Here we report significant and replicable association (P = 2.1 x 10(-6)) to a common variant located in intron 28 of the gene myosin IXB (MYO9B), which encodes an unconventional myosin molecule that has a role in actin remodeling of epithelial enterocytes. Individuals homozygous with respect to the at-risk allele have a 2.3-times higher risk of celiac disease (P = 1.55 x 10(-5)). This result is suggestive of a primary impairment of the intestinal barrier in the etiology of celiac disease, which may explain why immunogenic gluten peptides are able to pass through the epithelial barrier.     

Tumour biology: senescence in premalignant tumours

Oncogene-induced senescence is a cellular response that may be crucial for protection against cancer development, but its investigation has so far been restricted to cultured cells that have been manipulated to overexpress an oncogene. Here we analyse tumours initiated by an endogenous oncogene, ras, and show that senescent cells exist in premalignant tumours but not in malignant ones. Senescence is therefore a defining feature of premalignant tumours that could prove valuable in the diagnosis and prognosis of cancer.