The radioprotective effect of solcoseryl

Zusammenfassung Solcoseryl^® ruft bei Mäusen 1 h vor Bestrahlung mit letalen Dosen von -Strahlen, i.p. oder p.o. appliziert, ein fast durchwegs 100%iges Überleben im Zeitraum von 30 Tagen hervor.     

Short-term and long-term radioprotective effect of magnesium pemoline

Zusammenfassung Magnesium-Pemoline, ein mildes Reizmittel für das Nervensystem, hat sich als gutes Strahlenschutzmittel für kurze oder lange Zeitdauer erwiesen. Für den Schutz über eine kurze Zeitdauer ist die Wirkung abhängig von der Arzneimitteldosis, für denjenigen über eine längere Zeitdauer (bis zu 2 Wochen) ist jedoch eine sehr hohe Dosis (75 mg/kg) notwendig.

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This work was supported in part by Grant No. 2 44 33 90 3 06 from the Norval Pierce Research Fund, University of Illinois and in part by a grant from Abbott Laboratories.     

The effect of stress factors on the spontaneous photon emission from microorganisms

The results of recent work on the photon emission from three yeasts and a bacterium is presented. Both visible region and ultraviolet photon emission is observed; however, no luminescence is observed in the absence of oxygen. The visible region emission is attributed to excited carbonyl groups and excited singlet oxygen dimers formed during the decomposition of lipid hydroperoxides. Possible sources of the ultraviolet photon emission are also examined. The use of microorganisms in the study of ultraweak photon emission and its relation to oxidative, temperature and chemical stress is reviewed and the applications and (or) functions of this photon emission are also discussed.     

The effect of stress factors on the spontaneous photon emission from microorganisms.

The results of recent work on the photon emission from three yeasts and a bacterium is presented. Both visible region and ultraviolet photon emission is observed; however, no luminescence is observed in the absence of oxygen. The visible region emission is attributed to excited carbonyl groups and excited singlet oxygen dimers formed during the decomposition of lipid hydroperoxides. Possible sources of the ultraviolet photon emission are also examined. The use of microorganisms in the study of ultraweak photon emission and its relation to oxidative, temperature and chemical stress is reviewed and the applications and (or) functions of this photon emission are also discussed.     

The polymerization of sickle hemoglobin in solutions and cells

The polymerization of sickle hemoglobin occurs by the same mechanisms in solutions and in cells, and involves the formation of 14 stranded fibers from hemoglobin molecules which have assumed a deoxy quaternary structure. The fibers form via two types of highly concentration-dependent nucleation processes: homogeneous nucleation in solutions with hemoglobin activity above a critical activity, and heterogeneous nucleation in similarly supersaturated solutions which also contain hemoglobin polymers. The latter pathway is dominant, and creates polymer arrays called domains. The individual polymers bend, but also cross-link, and the resulting mass behaves as a solid. The concentration of polymerized hemoglobin increases exponentially unless clamped by rate limiting effects such as oxygen delivery.     

Imaging oxygen in neural cell and tissue models by means of anionic cell-permeable phosphorescent nanoparticles

Cell-permeable phosphorescent probes enable the study of cell and tissue oxygenation, bioenergetics, metabolism, and pathological states such as stroke and hypoxia. A number of such probes have been described in recent years, the majority consisting of cationic small molecule and nanoparticle structures. While these probes continue to advance, adequate staining for the study of certain cell types using live imaging techniques remains elusive; this is particularly true for neural cells. Here we introduce novel probes for the analysis of neural cells and tissues: negatively charged poly(methyl methacrylate-co-methacrylic acid)-based nanoparticles impregnated with a phosphorescent Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP) dye (this form is referred to as PA1), and with an additional reference/antennae dye poly(9,9-diheptylfluorene-alt-9,9-di-p-tolyl-9H-fluorene) (this form is referred to as PA2). PA1 and PA2 are internalised by endocytosis, result in efficient staining in primary neurons, astrocytes, and PC12 cells and multi-cellular aggregates, and allow for the monitoring of local O₂ levels on a time-resolved fluorescence plate reader and PLIM microscope. PA2 also efficiently stains rat brain slices and permits detailed O₂ imaging experiments using both one and two-photon intensity-based modes and PLIM modes. Multiplexed analysis of embryonic rat brain slices reveals age-dependent staining patterns for PA2 and a highly heterogeneous distribution of O₂ in tissues, which we relate to the localisation of specific progenitor cell populations. Overall, these anionic probes are useful for sensing O₂ levels in various cells and tissues, particularly in neural cells, and facilitate high-resolution imaging of O₂ in 3D tissue models.     

The effect of imipramine and desipramine on UDP-glucuronyltransferase

Zusammenfassung Der Einfluss von Imipramin und Desipramin auf die Umwandlung von Bilirubin undo-Aminophenol in deren jeweilige Glukuronide wurde in vitro in der Leber untersucht. Imipramin blockiert die Umwandlung von Bilirubin und vono-Aminophenol, während Desipramin nur diejenige vono-Aminophenol blockiert.     

The stability of erythrocytes in solutions of Evan's Blue dye

Zusammenfassung Bei Behandlung mit hohen Konzentrationen von Evan's Blue sind rote Blutkörperchen von Hunden weniger stabil als solche von Menschen, Kaninchen oder Ziegen. Die Hundeerythrozyten wurden am stärksten angegriffen bei Konzentrationen von T 1824 zwischen 2–6 mg/cm³ und zeigen zunehmende Stabilität, wenn die Farbstoffkonzentrationen über oder unter diesem Wert liegen.     

The effect of L-dopa on pupillary diameter in mice

Summary Injection of L-dopa in mice produces dose-dependent mydriasis. Pre-treatment with peripheral dopa-decarboxylase inhibitors (carbidopa and benserazide) or with an alpha-adrenergic blocking agent (phentolamine) abolishes the pupillary dilation caused by L-dopa. Pretreatment with fusaric acid, an inhibitor of dopamine-beta-hydroxylase, also antagonizes the mydriatic effect of L-dopa. Thus, our results suggest that the mydriasis produced in mice following the injection of L-dopa is caused by its peripheral conversion to noradrenaline, which stimulates alpha-adrenergic receptors in the dilator iridis. There was no evidence that stimulation of specific dopaminergic receptors was involved.We are grateful to N. Rothschild, Head of Laboratory Animal Department, Sackler School of Medicine, for his help.     

The effect of lactose and iron on strontium absorption

In rats fed on a milk diet with or without the addition of lactose and/or iron the transileal strontium-85 transfer was higher by 14-38% and the intestinal strontium retention lower by 6-23% than in control rats fed on standard laboratory food.     

The effect of lactose and iron on strontium absorption

Summary In rats fed on a milk diet with or without the addition of lactose and/or iron the transileal strontium-85 transfer was higher by 14–38% and the intestinal strontium retention lower by 6–23% than in control rats fed on standard laboratory food.Presented, in part, at the 12th Yugoslav Symposium for Radiation Protection, Ohrid 1983, and at the 11th Regional Congress of IRPA (Austrian — Hungarian — Yugoslav Radiation Protection Meeting), Wien 1983. Acknowledgments. This work was supported by a research grant from the Scientific Research Council of the Socialist Republic of Croatia. The author thanks Mrs M. Buben for her technical assistance.