Frequency-domain study of the mechanical response of living striated muscle

Summary Small-amplitude sinusoidal displacements, in the frequency rang 4–100 Hz, were applied to intact whole frog sartorius muscle whilst in a state of tetanus. At low frequencies the muscle, was observed to do oscillatory work, while at higher frequencies it tended towards elastic behaviour. Frequency-response plots obtained were compared with those from other muscle preparations. Results were interpreted in terms of mechano-chemical transduction properties of muscle.The authors wish to thank the Australian Research Grants Commission for provision of the laser, and L. I. Patterson for construction of the mechanical apparatus.     

Dialyzable serum factors alter cellular immunity in pregnancy

Summary Lymphocyte responsiveness was found to be decreased in pregnant and increased in habitually aborting women. This is attributed to a dialyzable serum factor(s), that can be removed from the surface of lymphocytes by repeated washing.     

Human leukocyte and fibroblast interferons are structurally related

The coding sequences of the dDNAs of cloned human leukocyte interferon I and human fibroblast interferon show homologies of 45% at the nucleotide and 29% at the amino acid level. We conclude that the two genes were derived from a common ancestor.     

Effects of thalidomide on the skeleton of the rat foetus

Zusammenfassung Nach Thalidomidverabreichung an trächtigen Ratten fanden wir Fruchtresorption und Anomalien am fünften Brustbeinkern der Föten. Weitere ergänzende Skelettuntersuchungen ergaben, besonders bei mittelgrossen Thalidomidgaben, Verknöcherungs-störungen an den Halswirbelkörpern. Andere Skeletteile zeigten keine Thalidomid-abhängigen Entwicklungsvariationen.     

Effect of biogenic amines on γ-amylase (acid α-glucosidase)

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Bacteriocinogeny inProteus rettgeri

Zusammenfassung In 2 von 7 Stämmen vonProteus rettgeri gelang die Induktion von Bakteriozinen unter der Einwirkung von Mitomycin C. Die gewonnenen Bakteriozine waren chloroformbeständig, trypsinresistent und hitzelabil.     

Threo-3,4-Dihydroxyphenylserine,a poor source of noradrenaline in the rat

Résumé Chez le rat, les injections dedl-thréo-3,4-dihydroxyphénylsérine, un précurseur pharmacologique synthétique de la noradrénaline, provoquent une conversion de moins de 1% au 4-hydroxy-3-méthoxyphényl-glycol, le métabolite urinaire majeur de la noradrénaline dans cette espèce. Un nouveau cheminement qui entraîne une coupure latérale de la chaîne prit environ 10% de la dose et un autre 10% fût excrété comme un amino-acideO-méthylé; le sort de quelque 80% est inconnu.