Intraluminal pressure and equivalent arterial wall tension

Résumé P=T/r, une loi de Laplace, est d'habitude appliquée pour exprimer la relation entre la pression intraluminale (P) et la tension intramurale (T) d'un vaisseau de rayonr. Sur un segment tubulaire, et sur une bande hélicale de l'aorte du lapin, nous avons mesuré deux valeurs équivalentes,P _50% etT _50%, obtenues lorsque la contraction causée par la noradrénaline est réduite de moitié. Ainsi la valeur der, calculée en utilisant l'equationP=T/r, est environ 75% de la valeur mesurée.     

Cerebrovascular reactivity to CO2: Modulation by arterial pressure

Summary Cerebrovascular reactivity to CO₂ (CO₂R), measured in halothane-anesthetized rabbits, decreased as arterial pressure was increased either pharmacologically or mechanically. On the other hand, hypotension, induced by bleeding, led to an increase in CO₂R. These responses were unaffected by denervation of baroreceptors.This work was supported by grants from NIH (HL 17903) and American Heart Association — Greater Los Angeles Affiliate (437IG). To whom requests for reprints should be sent.     

Cerebrovascular reactivity to CO2: modulation by arterial pressure

Cerebrovascular reactivity to CO2 (CO2R), measured in halothane-anesthetized rabbits, decreased as arterial pressure was increased either pharmacologically or mechanically. On the other hand, hypotension, induced by bleeding, led to an increase in CO2R. These responses were unaffected by denervation of baroreceptors.     

The effect of microcytosis on red cell constituents

Zusammenfassung Der Gehalt an Riboflavin, Azetylcholin-Esterase, Glutamat-Oxalacetat-Transaminase, Glutamat-Pyruvat-Transaminase und Folinsäure wurde in menschlichen Erythrozyten verschiedener Grössenordnung bestimmt. Die Ergebnisse sprechen dafür, dass ihre intrazelluläre Konzentration, im Gegensatz zu derjenigen des Hämoglobins, keinen limitierenden Einfluss auf die Fortdauer der Synthese dieser Stoffe ausübt.

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This work was supported by grants from Tenovus and the Endowment Fund of the United Cardiff Hospitals.     

Effect of sudden reductions of the arterial blood pressure on the mean diastolic coronary resistance

Summary At the beginning of a 10 sec arterial haemorrhage, vascular elasticity induces an increase of mean diastolic coronary resistance. Then, the increase is counteracted by the relaxation of the vascular musculature, which causes a coronary hyperaemia when, after the haemorrhage is arrested, the vascular wall is stretched by a sudden though slight increase of blood pressure.Acknowledgment. The authors wish to thank Mr Rodolfo Dalla Valle for his technical assistance.     

The leakage of intracellular constituents from heated suspensions ofStaphylococcus aureus

Résumé Une analyse a été fait des substances que perdent les cellules deStaphylococcus aureus chauffées à 50 °C et 60 °C. Ces substances comprennent des acides aminés, de la proteine et des substances absorbantes à une longeur d'onde de 260 nm.     

The interaction of warfarin with antacid constituents in the gut

Summary A study was made of the effect of 4 constituents of antacid preparations on the absorption of the coumarin derivate warfarin sodium using an in vitro experimental model. The constituents tested were activated dimethicone (a silicone) magnesium trisilicate, bismuth carbonate and the adsorbant, kaolin. Slight decreased intestinal absorption was shown by magnesium trisilicate (19%) and bismuth carbonate (7%), the other 2 components showing no effects.     

The interaction of warfarin with antacid constituents in the gut.

A study was made of the effect of 4 constituents of antacid preparations on the absorption of the coumarin derivate warfarin sodium using an in vitro experimental model. The constituents tested were activated dimethiocone (a silicone) magnesium trisilicate, bismuth carbonate and the adsorbant, kaolin. Slight decreased intestinal absorption was shown by magnesium trisilicate (19%) and bismuth carbonate (7%), the other 2 components showing no effects.     

The effect of potato virus X on the nitrogenous constituents of potatoes

Summary Infection with potato virus X (PVX) increased the total nitrogen and non-protein nitrogen contents of Katahdin tubers. Protein nitrogen remained unchanged, but a 22% increase in free amino acid content accompanied infection. No differences were observed in the number or composition of protein fractions in infected tubers.     

Effects ofl-dopa alone and in combination with dopa decarboxylase inhibitors on the arterial pressure and heart rate of dogs

Zusammenfassung Nach Vorbehandlung mitl-HMD (peripherer Hemmer der Dopa-Dekarboxylase) wird mitl-Dopa (25 und 50 mg/kg i.v.) Blutdruck und Herzfrequenz herabgesetzt.     

Interrelationship between mean arterial blood pressure,blood flow,and vascular resistance in solid tumor tissue of DS-carcinosarcoma

Zusammenfassung In vivo-Untersuchungen der Tumordurchblutung an Implantationstumoren eines DS-Carcinosarkoms in der Rattenniere zeigen eine deutliche Abhängigkeit der Durchblutungsgrösse vom Tumorgewicht. Bei Variation des arteriellen Mitteldrucks zwischen 40 und 135 mm Hg steigt die Durchblutung der einzelnen Tumoren linear mit zunehmendem Perfusionsdruck an. Eine zunehmende Rarefizierung der terminalen Strombahn mit ansteigendem Tumorgewicht wird belegt durch eine starke Zunahme des Strömungswiderstandes, der schon bei sehr jungen Tumoren wesentlich höhere Werte als bei verschiedenen Organen aufweist.

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Supported by the Landesversicherungsanstalt Rheinland-Pfalz, Speyer/Rh.     

Unsaponifiable constituents inSpirographis spallanzani

Riassunto L'insaponificabile del muscolo diSpirographis spallanzani contiene accanto a steroli e tocoferolo, un composto di natura chinonica avente molte proprietà in comune con gli ubichinoni. Anche il tocoferilchinone è stato identificato negli estratti. Si ritiene però che esso si formi dal tocoferolo durante il procedimento di estrazione.

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This work has been partially supported by a U.S. Public Health Service Grant (R.G. 4845). The authors gratefully acknowledge suggestions and criticisms from Dr.Hemming and Dr.Pennock, Biochemistry Department, Liverpool.     

Heartwood constituents ofPinus formosana

Zusammenfassung Die Untersuchung der sauren Anteile eines Extraktes des Kernholzes vonPinus formosana zeigte das Vorhandensein von Pinostrobin und Tectochrysin neben Dehydroabietin- und Isodextroprimarsäure. Diese Befunde erlauben,P. formosana der Gruppe Haploxylon zuzuteilen.     

The rate of incorporation of gaseous14CO2 into brain tissue constituents

Zusammenfassung Die¹⁴CO₂-Fixation verschiedener Fraktionen des Rattengehirnes wurde untersucht. Die Ratten wurden 15–120 min in gasförmigem¹⁴CO₂ exponiert und in flüssigem N₂ gefroren. Nach 15, 30, 60 und 120 min waren 9, 17, 21 und 35% vom Gesamt-¹⁴CO₂ in der Gehirnsubstanz organisch gebunden. Der grösste Teil des organischen¹⁴CO₂ fand sich in säurelöslicher Fraktion, während ein kleinerer Teil (etwa 10%) aus der Proteinfraktion isoliert werden konnte.