Induction of micronuclei in PHA-stimulated human lymphocyte cultures by therapeutic radiation

Summary Micronuclei frequency and percent of chromosome breaks increases significantly in adults whose thymus glands were irradiated in infancy and after irradiation of cancer patients.Acknowledgments. This work was supported by a grant, No. CA-14876, from the National Cancer Institute. Rita Giuliano gave valuable technical assistance.     

Lymphocyte survival and macrophage growth in long term in vitro leucocyte cultures

Zusammenfassung Unterschwellige Dosen von Phytohämagglutinin verlängern die Lebensdauer von Lymphozyten in menschlichen Zellkulturen, vermindern die Zahl der Makrophagen in der Kultur und erhöhen die Zahl der transformationsfähigen Lymphozyten.     

Induction of mitotic abnormalities in the root tips ofAllium cepa by tobacco smoke

Zusammenfassung Es wurden Untersuchungen der Wirkung des Tabakrauches auf mitotische Fehler beiAllium-cepa-L.-Sämlingen gemacht und dabei eine Abnahme des mitotischen Indexes und induzierte mitotische Missbilungen gefunden.

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This study was carried out under contract No. 12-14-100-10341 (73) with the Agricultural Research Service, U.S. Department of Agriculture, administered by the Southeastern Marketing and Nutrition Research Division, RRC, Athens, Georgia, 30604.     

Induction of morphological aberrations by enzyme inhibition inDrosophila melanogaster

Zusammenfassung Zusatz zum Futter vonDrosophila melanogaster von 5-Fluoro-2-deoxyuridin oder Aminopterin induziert überzählige Skutellar- und Dorsozentralborsten sowie gekerbte Flügel. Diese Modifikationen wurden als Konsequenz von Enzymhemmung interpretiert.     

Chromosome aberrations induced by daunomycin in human leucocyte cultures,with the apparent synergistic effect of arginine

Zusammenfassung Das Antibiotikum und Zytostatikum Daunomycin induziert beträchtliche Chromosomenaberrationen in menschlichen Leukozyten in der Konzentration von 0,02 µg/cm³. Dieser Effekt wird durch Zusatz von Arginin zur Zellkultur wesentlich verstärkt, und die Aberrationen werden auch qualitativ verändert. Es ist nicht bekannt, wie Daunomycin und Arginine aufeinander einwirken.     

Induction of root-coiling by 2-chloroethane phosphonic acid and its reversal by 2,3,5-triiodobenzoic acid

Résumé L'éthrel provoque l'enroulement des racines du jeuneIpomoea pentaphylla. Cet effet est complètement annulé par l'adjonction de TIBA.     

Pentobarbital sodium and chromosome abnormalities in rabbit blastocysts.

Female rabbits were injected with pentobarbital sodium at 1/4 h or 6 h post coitum. A slight delay in oocyte maturation was evident in animals killed at 17 h pc, however, zygote development appeared normal by 24 h pc. At 6 days pc, a greater frequency of chromosomally abnormal blastocysts was found in animals injected with pentobarbital than in control rabbits.     

Induction of chromosome aberrations and chlorophyll mutations in plants by methylisocyanate (MIC) gas

Summary Seeds ofSolanum surattense Burm. f. collected from areas of Bhopal (India) affected by methylisocyanate gas showed chromosome aberrations in root cells, and growth retardation and chlorophyll mutation of seedlings, the frequencies of which varied from one locality to another.     

Cystamine inhibition of enzyme induction and acetate oxidation inPseudomonas aeruginosa and reversal by high salt concentrations

Riassunto L'inibizione della ossidazione di acetato e della induzione di benzoato-ossidasi da parte della cistamina in un ceppo diPseudomonas aeruginosa, varia colla concentrazione del mezzo nel quale le cellule sono sospese. L'effetto inhibitorio diminuisce con l'aumentare della concentrazione del buffer. Altre diamine e cistamina in forma ridotta sono inattive. La cistenia inibisce le medesime reazioni ma il suo effetto è indipendente della concentrazione del mezzo di sospensione. La cistina è priva di effetto.     

Hydrolysis of human leucocyte phospholipids by snake venoms

Résumé Les phospholipases A des venins du serpentVipera palestinae et duNaja naja ne clivent pas des phospholipides de leucocytes intacts, sauf en présence d'un facteur lytique se trouvant dans le venin deNaja naja. L'activité des phospholipases des deux venins sur les leucocytes endommagés n'est pas la même.     

Induction of neovascularization in vivo by glycerol

Glycerol, injected into a site between the femoral vessels of the rat, induced neovascularization, both from the preexisting microcirculation and from the side of the femoral vein facing the artery-vein interstitium where the glycerol was administered. The use of glycerol together with a known angiogenic substance (PGE₂) did not modify the neocapillary density (NCD) obtained with glycerol alone. In contrast, the lower level of NCD achieved with an acylglycerol (triacetylglycerol) was increased when the latter was associated with PGE₂. Values reached were similar to, but never higher than, those for glycerol alone, or combined with PGE₂. The results suggest that glycerol and some substances containing glycerol, amongst which 1-butyrylglycerol has been previously considered¹, may stimulate angiogenesis by a direct or indirect mechanism of action.     

Induction of morphological changes in bacteria by optochin

Zusammenfassung Es wird die Wirkung des Optochins auf die Zellmorphologie desBacterium anitratum beschrieben und aus Versuchsergebnissen geschlossen, dass Optochin zur Gruppe chemischer Substanzen gehört, die zu hochgradigen morphologischen Veränderungen der Bakterienzelle führen.     

Platelet aggregation and stimulation of leucocyte procoagulant activity by rickettsial lipopolysaccharides in rabbits and in man

Summary The effects in vitro of 4 purified lipopolysaccharide (LPS) preparations from Rickettsiae on platelets and leucocytes were studied in rabbits and in man. All LPS induced aggregation in rabbit platelet-rich plasma but to differing degrees. This activity was abolished by inactivation of complement. None of the preparations induced aggregation of human platelets. Both rabbit and human leucocytes, when incubated with each of the rickettsial LPS preparations, generated a potent procoagulant activity (tissue factor). These findings add further support to the concept that rickettsial LPS behave as typical LPS from gram-negative bacteria and may be relevant to the understanding of the mechanism(s) responsible for triggering intravascular coagulation in rickettsial diseases.     

Induction of delayed hypersensitivity by carrageenan

Zusammenfassung Nachweis einer Sensibilisierung des Meerschweinchens durch intradermale Injektion von Carrageenan, was zu «passiv übertragbaren» Spätreaktionen führte.

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The authors wish to thank to MissI. Kawana, MissA. Saito and MissA. Chida for their technical assistance and Prof.Y. Horiuchi for his advice.     

Induction of uncoiled chromosomes by vibration

Summary Chromatin condensation during metaphase can be removed by simple vibration of metaphase cells prior to fixation. Uncoiled chromosome arms consist of long threads with dense regions at irregular distances each from the other.Acknowledgment. This work is supported by the Hellenic Anticancer Institute.