Liver monoamine oxidase in normal and regeneratingDiemictylus viridescens

Résumé L'oxydase monoamine se trouve sous une forme active dans le foie d'un urodèle adulte capable d'activité normale et régénératrice. Au cours des deux premières heures qui suivent l'amputation d'un membre antérieur, on peut noter une augmentation appréciable de l'activité de l'oxydase monoamine. Cette augmentation indique que la tension physiologique produite par l'amputation rend actifs dans le foie les précurseurs de l'oxydase monoamine qui peuvent, à leur tour, stimuler un métabolisme plus rapide et augmenter la quantité des catécholamines qui circulent.     

Mechanical responses of the isolated cervix of the day-22 pregnant rat to field stimulation

Summary Field stimulation of isolated, spirally-cut cervix from day-22 pregnant rats produced contractions which could be inhibited by tetrodotoxin or hyoscine and potentiated by propranolol. The rat cervix would appear to receive both cholinergic and noradrenergic innervations whose transmitters activate muscarinic cholinoceptors and -adrenoceptors respectively.We thank the Lalor Foundation, USA, for financial support.     

态度决定人生

态度是决定一个人的观点和人生经历的关键因素。我们的观点和经历反过来又会影响我们对人生的态度。态度是我们每时每刻自由做出的选择。人生经历中的种种因素都会影响到我们的人生观和世界观。探讨了人生态度是如何影响生活质量的。     

DNA sequence of human chromosome 17 and analysis of rearrangement in the human lineage

Chromosome 17 is unusual among the human chromosomes in many respects. It is the largest human autosome with orthology to only a single mouse chromosome, mapping entirely to the distal half of mouse chromosome 11. Chromosome 17 is rich in protein-coding genes, having the second highest gene density in the genome. It is also enriched in segmental duplications, ranking third in density among the autosomes. Here we report a finished sequence for human chromosome 17, as well as a structural comparison with the finished sequence for mouse chromosome 11, the first finished mouse chromosome. Comparison of the orthologous regions reveals striking differences. In contrast to the typical pattern seen in mammalian evolution, the human sequence has undergone extensive intrachromosomal rearrangement, whereas the mouse sequence has been remarkably stable. Moreover, although the human sequence has a high density of segmental duplication, the mouse sequence has a very low density. Notably, these segmental duplications correspond closely to the sites of structural rearrangement, demonstrating a link between duplication and rearrangement. Examination of the main classes of duplicated segments provides insight into the dynamics underlying expansion of chromosome-specific, low-copy repeats in the human genome.     

A basal tyrannosauroid dinosaur from the Late Jurassic of China

The tyrannosauroid fossil record is mainly restricted to Cretaceous sediments of Laurasia, although some very fragmentary Jurassic specimens have been referred to this group. Here we report a new basal tyrannosauroid, Guanlong wucaii gen. et sp. nov., from the lower Upper Jurassic of the Junggar Basin, northwestern China. G. wucaii is the oldest known tyrannosauroid and shows several unexpectedly primitive pelvic features. Nevertheless, the limbs of G. wucaii share several features with derived coelurosaurs, and it possesses features shared by other coelurosaurian clades. This unusual combination of character states provides an insight into the poorly known early radiation of the Coelurosauria. Notably, the presumed predatory Guanlong has a large, fragile and highly pneumatic cranial crest that is among the most elaborate known in any non-avian dinosaur and could be comparable to some classical exaggerated ornamental traits among vertebrates.     

Protein turnover in skeletal muscle and liver of rats bearing the Walker 256 carcinoma

Résumé Les protéines des tissus de rats ont été marquées au moyen del-Lysine-4, 5-H3. Une inoculation de Carcinome Walker 256 a été effectuée 7 jours après. Des observations de perte de protéines radioactives indiquent que chez les rats avec tumeur la dégradation des protéines du gastrocnémius augmente celle des protéines du foie, diminue et que celle du soléus n'est pas modifiée.

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This work was supported by the Scottish Hospital Endowments Research Trust.