Suppression of ethanol withdrawal by dopamine

Summary An ethanol-inhalation technique was used to determine a potential relationship between dopamine and central nervous effects produced by alcohol. Bothl-DOPA and intracranially injected dopamine resulted in attenuation of ethanol-induced withdrawal convulsion scores, whereas, haloperidol, a known dopaminergic blocker was found to significantly increase convulsion scores.We thankB. Wiggins, S. Elston andRaul Marin for technical help. The work was supported gy NIH, Air Force Office of Scientific Research and Pharmaceutical Manufacturers Association Grants. Dr.Blum is also a recipient of the Career Teacher Award, Grant No. 1-T01-D100290-01.     

Suppression of graft-versus-host reaction by phytohemagglutinin

Zusammenfassung Mit Phytohämagglutinin behandelte Milzzellen erwachsener Mäuse, übertragen auf neugeborene Balb/c-Mäuse, lösen die erwartete « Runt-disease » nicht aus. Versuche mit Milzzellsuspensionen werden diskutiert.

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This investigation was supported by U.S. Atomic Energy Commission, contracts Nos. RLO-1927-26 and AT (45-1)-581.     

Suppression of the primary immune response by antilymphocyte serum

Zusammenfassung Die immunosuppressive Wirkung des Antilymphozytenserums wird beschrieben.     

Some observations on the effect of Ro 7-1051 on Trypanosoma cruzi,particularly in cell culture

Summary The drug Ro 7-1051 showed a deleterious effect on the intracellular and extracellular forms of Trypanosoma cruzi represented by nuclear pyknosis, fragmentation and lysis of parasites and by its reduced susceptibility to infection.Acknowledgments. The authors are deeply thankful to Roche Products for supplying the drug and for valuable information. The authors are also grateful to Prof. Nelson Villa for criticism and to Miss edna Bertin for technical assistance     

Use of the specific benzodiazepine antagonist,Ro 15-1788, in studies of physiological dependence on benzodiazepines

Summary The specific benzodiazepine antagonist, Ro 15-1788, elicited withdrawal symptoms in squirrel monkeys, cats, rats and mice made tolerant and physically dependent by subchronic administration of high doses of diazepam, lorazepam or triazolam.     

Suppression of experimental allergic encephalomyelitis by vitamin A

Résumé L'encéphalomyélite allergique expérimentale n'apparaît pas chez les cobayes auxquels on a injecté de fortes doses de vitamine A.

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The authors are indebted toElisabeth Móre for technical assistance.     

Suppression of cellular immunity in vivo by rifampicin

Zusammenfassung Rifampicin hemmte die Tuberkulinreaktion bei Meerschweinchen. Eine andere Manifestation zellulärer Immunität, die Abstossung von Hautallotransplantaten bei Mäusen, wurde erst bei Anwendung toxischer Dosen des Tuberkulostatikums vermindert.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

Summary The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Suppression of erythropoiesis by administration of deoxycorticosterone and corticosterone

Résumé Les stéroïdes surrénaux, déoxycorticostérone et corticostérone font diminuer l'érythropoïèse chez la souris femelle. La suppression produite par le corticostérone a lieu plus tôt et est plus grande que celle qui résulte du traitement au déoxycorticostérone.

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Supported by grants from the United Medical Research Foundation of North Carolina and the Foundation of the University of North Carolina at Charlotte.     

Suppression of delayed type hypersensitivity of mice by lead

Summary Application of lead suppressed the delayed type hypersensitivity (DTH) of mice induced by sheep red blood cells (SRBC). Inhibition of elicitation of DTH in primary as well as in secondary response was correlated with the concentration of lead in the blood of the mice.Acknowledgments. Supported by the Georg-und-Agnes-Blumenthal-Stiftung and the Verein für Wasser-, Boden- und Lufthygiene. We thank Miss Schachtschneider for the excellent technical assistance.     

Selective antagonism by Mg2+ of amino acid-induced depolarization of spinal neurones

Summary In the isolated frog or rat spinal cord, low concentrations of Mg²⁺ (0.5–1.00 mM) markedly depress, in a substantially Ca²⁺-independent manner, ventral root depolarizations produced by dorsal root stimulation and by certain amino acids (e. g. N-methyl-D-aspartate and L-homocysteate) but do not depress depolarizations produced by other excitatory amino acids (e. g. kainate and quisqualate). L-Aspartate-induced depolarizations are more sensitive to Mg²⁺ then are L-glutamate-induced depolarizations.Acknowledgment. We thank D. J. Oakes for skilled technica assistance. This work was supported by the Medical Research Council.     

Suppression of mitogen- and antigen-induced lymphocyte proliferation by lanthanides

Lanthanide ions (Ln3+) inhibited the proliferative response of human lymphocytes to various polyclonal mitogens and the 'purified protein derivative' (PPD) of the tuberculin antigen. Of the four Ln3+ ions tested lanthanum (La3+) was the strongest inhibitor; erbium (Er3+) and lutetium (Lu3+) were only weakly active, while samarium (Sm3+) had intermediate potency. At a concentration of 1 mM, La3+ almost completely inhibited the uptake of [3H]-thymidine by lymphocytes exposed to mitogenic agents. Trypan blue exclusion tests confirmed that the La3+ ions were not toxic. These findings may bear upon the reported anti-inflammatory properties of the lanthanides.     

Suppression of paradoxal sleep by clonidine in man]

The administration of clonidine (300 mug) suppresses REM sleep or strikingly diminishes its duration in Man. The statistical difference with placebo given in a double blind trial is highly significant. This suppression of REM sleep may depend on the stimulation of alpha-adrenergic receptors.     

Suppression of PHA-induced lymphocyte blastogenesis by concomitant presence of PPD in the culture

Summary PHA-induced lymphocyte blastogenic response was remarkably suppressed by the simultaneous presence of PPD in cultures of lymphocytes derived from individuals sensitized to PPD, but not affected by the presence of PPD when the cultures contained lymphocytes from an individual not sensitized to the protein. This double stimulation blastogenesis study with PHA and a specific antigen is feasible as a simple and rapid test to measure cell-mediated immunity to the antigen.Supported by United States grant USPHS Grant AM 27384.     

Disappearance of radioactivity from plasma following intravenous administration of tritiated thyrotrophin-releasing hormone (Ro 8-6270) to man

Zusammenfassung Nach i. v. Verabreichung von Thyrotrophin-releasing Hormonen an Versuchspersonen ergibt sich eine biphasische Kurve für den Abfall der Tritiumaktivität im Plasma mit einer Exkretions-Halbwertszeit von 3 h.

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Acknowledgements. The authors wish to express their gratitude to Hoffmann-La Roche and Co. AG, Basel for the research funds which supported this work. We are indebted to Dr.C. Metzler, Upjohn Co., Kalamazoo for a gift of the NON-LIN computer programme.     

Selective antagonism by Mg2+ of amino acid-induced depolarization of spinal neurones.

In the isolated frog or rat spinal cord, low concentrations of Mg2+ (0.5-1.00 mM) markedly depress, in a substantially Ca2+-independent manner, ventral root depolarizations produced by dorsal root stimulation and by certain amino acids (e.g. N-methyl-D-aspartate and L-homocysteate) but do not depress depolarizations produced by other excitatory amino acids (e.g. kainate and quisqualate). L-Aspartate-induced depolarizations are more sensitive to Mg2+ then are L-glutamate-induced depolarizations.     

Suppression of carcinogen-induced rat mammary tumor formation by Actinomycin D

Zusammenfassung Sprague-Dawley-Ratten, die eine kombinierte Belastung mit 7,12-Dimethylbenz()anthrazen und Aktinomyzin D überleben, weisen eine drastisch erniedrigte tastbare Tumorinzidenz auf. Kontrolltiere erhielten nur das Karzinogen.     

Suppression of the immunological reaction by methylhydrazines,a new class of antitumour agents

Zusammenfassung 1-Methyl-2-p-(isopropylcarbamoyl)-benzyl-hydrazin-hydrochlorid (I), ein Cytostaticum, hemmt die Immunreaktion gegen heterologe Tumortransplantate. Diese Reaktion wird nur beeinträchtigt, wenn das Methylhydrazin-Derivat vor der Implantation gegeben wird. Die erwähnte Verbindung gehört einer Gruppe von neuen Cytostatica an, die unter anderem auch die Lymphopoese beeinflussen. Die Zusammenhänge zwischen der Wachstumshemmung gewisser mesenchymaler Gewebe (Lymphocyten, Plasmazellen etc.), der Beeinträchtigung der Antikörperproduktion bzw. der Unterdrückung der Immunreaktionen gegenüber fremden Geweben, werden diskutiert.