Positively heterochromatic segment in mitotic metaphase chromosomes ofVicia faba

Zusammenfassung Nach sukzessiver Behandlung der Wurzelspitze vonVicia faba mit 5%iger Trichlorsäure und dem Gemisch von einem Teil 1N HCl und 9 Teilen 45%iger Essigsäure treten bei Feulgenfärbung die schmalen, tief gefärbten +H-Segmente der Trabanten beider metaphasischen M-Chromosomen direkt an der Astbasis hervor. Das +H-Segment ist als « nucleolus organizing body » nachMcClintock 8 anzusehen.     

Release of nonspecific esterases from the roots ofVicia faba L

Summary Roots ofVicia faba L. immersed in a buffer solution were found to release esterases into the environment. The substrate -naphthylacetate was taken up by the roots and degraded, the hydrolysis products being released back into the surrounding medium.     

Triploidy in callus culture ofVicia faba L. investigated by the Giemsa C-banding technique

Summary Callus tissue ofVicia faba has been grown from explants of immature embryos. The karyological analysis by the Giemsa C-banding technique has shown triploid and tri-aneuploid mitoses, all with an extra chromosome and with structurally altered karyotypes. Estimates of the amounts of interphase heterochromatin (chromocentres) indicate endopolyploidy up to 12 n.This work was financially supported by the Research Council of the S.R. Croatia — SIZIV. The authors wish to express their gratitude to the Industroprojekt Zagreb for the use of the image analyser, to Mr M. Denih for the area determinations of drawings, and to Dr D. Schweizer, Vienna, for critical comments.     

Radioprotective effect of hydrocortison and prednisolon on theVicia faba equina

Résumé Avec leVicia faba test, nous avons pu démontrer l'effet radioprotecteur de l'hydrocortisone et de la prednisolone. L'effet radioprotecteur de la prednisolone est grosso modo, 4 fois plus important que celui de l'hydrocortisone.

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This work was made possible by a subsidy from the Swiss National Fund for Scientific Research.     

The incorporation of H3-thymidine in newly differentiated nuclei of roots ofVicia faba

Zusammenfassung Bohnenwurzeln (Vicia faba) wurden mit H³-Thymidin behandelt. Autoradiographien zeigen Aufnahmen von DNS in Zellkernen, welche keine Zellteilungen mehr durchmachen.     

The effect of sulphydryl agents on the ioxynilinhibited cyclic photophosphorylation in chloroplasts ofVicia faba L

Zusammenfassung Es wurde die Rolle von Cystein und Glutathion als Schutzmittel für Enzym-Sulfhydrylgruppen studiert. Zyklische Photophosphorylierung, durch PMS katalysiert und durch Herbizid Ioxynil gehemmt, kann durch Zugabe von 10M Cystein oder Glutathion wieder teilweise bis ständig hergestellt werden. Es wird eine Hypothese aufgestellt, wonach der Hemmungsmechanismus auf einer Radikal-Reaktion beruhe.     

Nuclear fusion and irregular cytokinesis in binucleate and tetraploid cells ofVicia faba after caffeine treatment

Summary By means of 3 h treatment with 0.2% caffeine solution, binucleate and tetraploid cells were obtained in the lateral root meristem ofVicia faba. During recovery changing rates of fused interphases were noticed. Cell walls were formed in the equatiorial plane of the preceeding division of binucleate and tetraploid cells at interphase and in the course of bimitosis or 4n-mitosis at prophase or metaphase; during bitelophase a constriction of the fused nuclei could be seen. The conclusion is that the basic requirements of cytokinesis are not affected by caffeine.     

Protection against cocarcinogenesis by antioxidants

Zusammenfassung Natrium-Selenid und andere Antioxydantien können die Entstehung von Tumoren hemmen. Die Wirkung kommt möglicherweise zustande über eine Hemmung der Bildung von Co-Carcinogenen.     

Protection by antioxidants against ozone toxicity in mice

Zusammenfassung 16 Antioxidantien wurden auf ihre Schutzwirkung gegen Ozontoxizität in Mäusen geprüft. AHQ, Primaquin und EMQ waren hochwirksam, BHA, NDGA und Ascarbinsäure mässig wirksam, und die übrigen zeigten keinen nennenswerten Effekt.

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We thank Dr. D.Coffin for his advice and for the gift of the exposure chambers. This work was supported by N.I.H. Grants No. C-6516 and No. FR-05526 (to the Children's Cancer Research Foundation, Inc.) and has been submitted in partial fulfillment of requirements for an MS thesis at the North Eastern University, Boston, Massachusetts (by L.Pagnotto).     

Inactivation of aldolase by X-rays

Riassunto È stata studiata in vitro l'inattivazione da raggi x dell'aldolasi dal muscolo di coniglio. Il rendimento di inattivazione corrisponde a 0,10 (molecule/100 ev) per concentrazioni comprese tra 10^–5 and 10^–6 M in tampone di fosfati 0,05M, pH 7. Il rendimento non subisce modificazioni di rilievo variando il pH da 6 a 8 o sostituendo al tampone l'acqua bidistillata. Il rendimento é ridotto da 4 a 6 volte in presenza di cisteamina, di cisteina o dei corrispondenti disolfuri in concentrazioni corrispondenti a 50 molecule per molecola di enzima. Coll'ioduro di sodio in concentrazione di 600:1 si ottiene una riduzione di 6 volte.     

Protection against mercuric chloride nephropathy by sodium selenite in the rat]

Daily intraperitoneal injection of 2.5 or 5 mumole HgCl2 to male Rats weighing 250 to 350 g induces an early intense increase of urine gamma-glutamyl transferase activity. In the same conditions, equimolecular administration of sodium selenite and mercuric chloride induces no increase of the enzymuria for the low dose: for the high dose- a minor and more persistent increase of urine GGT is observed. Thus, the activity of urines GGT allows, in vivo, to establish that sodium selenite protects Rat kidney against toxic effects of mercuric chloride.     

Protection by chlorpromazine against lethality and renal toxicity of cisplatin in mice

The effect of chlorpromazine on acute lethal toxicity and nephrotoxicity induced by cisplatin was studied in mice. Chlorpromazine given (i.p.) 1 h before cisplatin greatly reduced lethal and renal toxicities of cisplatin. Chlorpromazine did not reduce the antitumor activity of cisplatin against Sarcoma 180 in ddY mice or EL-4 Leukemia in C57BL/6J mice.     

Protection by chlorpromazine against lethality and renal toxicity of cisplatin in mice.

The effect of chlorpromazine on acute lethal toxicity and nephrotoxicity induced by cisplatin was studied in mice. Chlorpromazine given (i.p.) 1 h before cisplatin greatly reduced lethal and renal toxicities of cisplatin. Chlorpromazine did not reduce the antitumor activity of cisplatin against Sarcoma 180 in ddY mice or EL-4 Leukemia in C57BL/6J mice.     

Protection of the mouse from genetic radiation damage by an optimal-dose-ratio combination of ATP,AET, and serotonin

Summary The study concerned antiradiation effects in germ-cell genetic structures produced by a combination of ATP, AET, and serotonin at dose ratio optimal for lethality namely, 4531, as arrived at in our previous work. Such a combination was found to reduce by a factor of 2 the translocation yields observed after 400 R X-rays to mouse spermatogonia. In terms of animal survival, ATP has been shown to contribute little to total protection achieved by the same combination; in terms of genetic damage; however, the role of ATP proved essential. Removal of ATP from the combination led to a significant reduction in protective effect.     

Protection against gastrointestinal effects of whole-body X-irradiation by a bile acid sequestrant in rats

Zusammenfassung Nachweis, dass die Gallensalze an der Entstehung des gastrointestinalen Strahlensyndroms mitverantwortlich sind und dass DEAE-Sephadex die Gallensalze bindet und die Überlebenszeit letal behandelter Ratten verlängert.