Induction of a 70,000 dalton protein in hypertrophic rat heart

Two-dimensional gel electrophoresis analysis of the product of in vitro translation of polyadenylated RNAs extracted from rat heart rendered hypertrophic by aortic constriction, shows a new protein species not present in the map of control hearts. The same is also obtained when hypertrophy is induced by treatment with thyroxine.     

Double stranded ribonuclease activity in human lymphocyte nuclei

Summary Ribonuclease activity directed against the synthetic duplex polyrC: polyrI was detected in nuclear extracts from both unstimulated and PHA-stimulated human lymphocytes. In the latter cells, the activity was about twice that of small lymphocytes.     

Reinforcement with naloxone of N-n-propylnorapomorphine (NPA) capability for stimulating male rat copulatory behavior

Summary Naloxone at a dose of 2 mg·kg^–1, which per se did not significantly alter the copulatory pattern of sexually active adult male rats, did significantly reduce the intromission frequency as well as latency to ejaculation when administered before a low and inactive dose of N-n-propylnorapomorphine (0.5 g·kg^–1).     

Double stranded ribonuclease activity in human lymphocyte nuclei.

Ribonuclease activity directed against the synthetic duplex polyrC:polyI was detected in nuclear extracts from both unstimulated and PHA-stimulated human lymphocytes. In the latter cells, the activity was about twice that of small lymphocytes.     

The Lkb1 metabolic sensor maintains haematopoietic stem cell survival

Haematopoietic stem cells (HSCs) can convert between growth states that have marked differences in bioenergetic needs. Although often quiescent in adults, these cells become proliferative upon physiological demand. Balancing HSC energetics in response to nutrient availability and growth state is poorly understood, yet essential for the dynamism of the haematopoietic system. Here we show that the Lkb1 tumour suppressor is critical for the maintenance of energy homeostasis in haematopoietic cells. Lkb1 inactivation in adult mice causes loss of HSC quiescence followed by rapid depletion of all haematopoietic subpopulations. Lkb1-deficient bone marrow cells exhibit mitochondrial defects, alterations in lipid and nucleotide metabolism, and depletion of cellular ATP. The haematopoietic effects are largely independent of Lkb1 regulation of AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signalling. Instead, these data define a central role for Lkb1 in restricting HSC entry into cell cycle and in broadly maintaining energy homeostasis in haematopoietic cells through a novel metabolic checkpoint.     

Stretching activity in dogs intracisternally injected with a synthetic melanocyte-stimulating hexapeptide

Riassunto La iniezione endocisternale nel cane di dosi fino a 0.75 mg/kg del sale acetico dell'esapeptide H. Glu (NH₂)-Ist-Fen-Arg-Tript-Gli.OH, svolgente un'attività melanoforo-stimolante della intensità di 2 × 10⁵ U/g, induce delle tipiche crisi di stiramento, del tutto simili a quelle che si ottengono iniettando per la stessa via dell'ACTH o dell'MSH. Dosi di 1.5 mg/kg invece non inducono più crisi di stiramento ma deprimono notevolmente gli animali e determinano una intensa scialorrea. Sembra di poter ammettere che la struttura chimica responsabile dell'effetto sui melanociti sia anche responsabile dell'induzione delle crisi di stiramento.

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We are indebted to Dr.R. Schwyzer, CIBA Ltd., Basle (Switzerland), for the synthetic melanocyte-stimulating hexapeptide.     

A simple microcolorimetric method for the determination of pyruvate in 0,1 ml samples of blood

Riassunto Viene descritto un micrometodo colorimetrico alla 2,4 dinitrofenilidrazina che permette la determinazione del piruvato ematico in 0,1 ml di sangue. Il metodo è di semplice attuazione e soddisfa ai normali criteri analitici.     

Induction of a 70,000 dalton protein in hypertrophic rat heart

Summary Two-dimensional gel electrophoresis analysis of the product of in vitro translation of polyadenylated RNAs extracted from rat heart rendered hypertrophic by aortic constriction, shows a new protein species not present in the map of control hearts. The same is also obtained when hypertrophy is induced by treatment with thyroxine.