The in vitro stability in human plasma of two different technetium-99m-fibrinogen compounds

Summary Two^99mTc-labeling methods of human fibrinogen resulted in different complexes. This was concluded from different dissociation rates in human plasma. The dissociation could be described by a simple exponential function.     

Labeling of endotoxin lipopolysaccharide with technetium-99m pertechnetate

Summry Bacterial endotoxin treated with technetium-99m can be visualized in living animals by gamma camera imaging.This work was supported in part by grant No. M4 305105-3100 from the Naval Research and Development Command.     

Insulin effect in vitro on human erythrocyte plasma membrane

The effect of porcine insulin has been tested in vitro on human erythrocyte plasma membrane (Na+-K+) and Mg2+-ATPase activities as well as on membrane fluidity. The results indicate that the hormonal treatment significantly inhibits (Na+-K+)-ATPase activity, and at the same time decreases membrane fluidity.     

Insulin effect in vitro on human erythrocyte plasma membrane

Summary The effect of porcine insulin has been tested in vitro on human erythrocyte plasma membrane (Na⁺–K⁺) and Mg²⁺-ATPase activities as well as on membrane fluidity. The results indicate that the hormonal treatment significantly inhibits (Na⁺–K⁺)-ATPase activity, and at the same time decreases membrane fluidity.This investigation has been supported by Consiglio Nazionale delle Richerche, Rome, Italy.     

Albumin concentration in plasma of two related species ofCeratophrys (Anura Leptodactylidae) from two different environments

Summary Albumin concentration in plasma of two related species ofCeratophrys, C. cranwelli andC. ornata was analyzed and shown to be higher in the former species, which is the adaptive form found in dry areas.     

Synthesis in vitro of immunoglobulins produced by different human mucous membranes

Riassunto Gli autori hanno dimostrato che alcune mucose della specie umana (mucosa congiuntivale, gengivale, nasale, vaginale e rettale) a contatto con l'ambiente esterno, sono in grado in vitro di sintetizzare le immunoglobuline (IgG, IgA, IgM) in diversa proporzione. La formazione di queste immunoglobuline può rivestire il significato di un meccanismo di difesa locale di tipo immunitario.     

In vitro effects of melanocytolytic agents and other compounds upon dominant human melanoma tyrosinase activity

Summary The activity of dominant human melanoma tyrosinase isozyme was greatly decreased by certain reducing agents. The number and geometry of phenolic groups as well as free-SH group appear important for enzymic inhibition.This investigation was supported by U.S. Public Health Service Research Grant No. CA-12731-02 and CA-15991-01 from National Cancer Institute.     

The formation of androgens in human foetal liver in vitro

Zusammenfassung Nach Inkubation des homogenisierten Lebergewebes menschlicher, 7–20 Wochen alter, Foeten mit 3-Hydroxy-5-androsten-17-on wird die Bildung von Testosteron, 4-Androsten-3, 17-dion und 5-Androsten-3, 17-diol nachgewiesen.     

The influence of different nutrients on plasma cholecystokinin levels in the rat

Isocaloric and isovolemic amounts of protein (casein), fat (intralipid) and carbohydrate (saccharose) and an isovolemic control solution of water were administered intragastrically to conscious rats. The plasma CCK levels, determined by a sensitive and specific radioimmunoassay, showed an increment of 6.3 +/- 0.6, 2.7 +/- 0.5, 1.7 +/- 0.4 and -0.9 +/- 0.4 pM, respectively (basal value 2.5 +/- 0.3 pM). The threshold increment of plasma CCK to stimulate pancreatic enzyme secretion by exogenous CCK was found to be 1.5 pM. It is therefore concluded that casein is a potent stimulus for CCK secretion and pancreatic secretion, but that fat and even carbohydrate, although less potent, also produce a CCK increment above the threshold for pancreatic secretion.     

The influence of different nutrients on plasma cholecystokinin levels in the rat

Summary Isocaloric and isovolemic amounts of protein (casein), fat (intralipid) and carbohydrate (saccharose) and an isovolemic control solution of water were administered intragastrically to conscious rats. The plasma CCK levels, determined by a sensitive and specific radioimmunoassay, showed an increment of 6.3±0.6, 2.7±0.5, 1.7±0.4 and –0.9±0.4 pM, respectively (basal value 2.5±0.3 pM). The threshold increment of plasma CCK to stimulate pancreatic enzyme secretion by exogenous CCK was found to be 1.5 pM. It is therefore concluded that casein is a potent stimulus for CCK secretion and pancreatic secretion, but that fat and even carbohydrate, although less potent, also produce a CCK increment above the threshold for pancreatic secretion.Supported by Grant IKW 86-16 from the Netherlands Cancer Foundation KWF.     

The effect of halothane on in vitro human neutrophil chemotaxis

Summary Increasing concentrations of halothane were shown to sequentially inhibit directed (chemotactic) and random movement of human peripheral blood neutrophils. No influence on neutrophil movement was apparent at clinically important concentrations, halothane may effect neutrophil microtubule and actomyosin microfilament systems.Acknowledgments. We thank Mr Lous Matej for his skillful technical assistance.     

In vitro effects of melanocytolytic agents and other compounds upon dominant human melanoma tyrosinase activity.

The activity of dominant human melanoma tyrosinase isozyme was greatly decreased by certain reducing agents. The number and geometry of phenolic groups as well as free--SH group appear important for enzymic inhibition.     

The interaction of protamine with human blood plasma proteins

Zusammenfassung Es wurden Interaktionen von Protamin mit vorher in Agar-Gel elektrophoretisch getrennten plasmatischen Eiweisskörpern untersucht. Neben der schon früher bekannten Interaktion mit Fibrinogen wurden auch solche mit beiden Klassen der plasmatischen Lipoproteine gefunden.     

Rheological properties of human blood plasma — A comparison of measurements with three different viscometers

Summary Human plasma viscosity was measured in capillary tube, cone-plate and Couette viscometers. The measurement of the viscosity at very low shear rates showed that plasma is a non-Newtonian fluid with a pseudoplastic rheological behaviour. The importance of this phenomenon for the microcirculation is discussed.We are grateful to OM Laboratories, Geneva, for providing the Contraves Low Shear 30 viscometer.     

Vasoactivity of human plasma and plasma protein fractions

Zusammenfassung Blutplasma des Menschen verengt isolierte, durchströmte kleine Blutgefässe. Dieser Effekt kommt nicht durch bekannte, gefässaktive Substanzen, sondern wahrscheinlich durch ein Protein zustande. Eine ähnliche Wirkung wurde in 2 Cohn-Fraktionen von Plasma-Proteinen gefunden, welche sich im Hundeversuch gefässdrucksenkend auswirkten. Plasma-Albumin ist an sich nicht gefässaktiv, es verstärkt aber die Wirkung der andern Substanzen.

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This work was supported in part by a grant from the National Heart Foundation of Australia.     

The presence of free D-serine,D-alanine and D-proline in human plasma

Twelve neutral free amino acids, i. e., serine, threonine, glutamine, asparagine, alanine, proline, methionine, tyrosine, valine, leucine, isoleucine and phenylalanine, were surveyed for the presence of D-enantiomers in plasma samples from patients with renal diseases and from normal subjects. D-serine, D-alanine and D-proline were found in the patient's plasma. The highest concentrations (D/L ratio) of D-serine, D-alanine and D-proline were 0.2362, 0.2087 and 0.0986, respectively. The sum of the contents of the three D-amino acids in a plasma sample correlated with the serum creatinine level of the subject. No D-amino acid was shown to be present in the plasma proteins.