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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 124 (1998), S. 131-140 
    ISSN: 1432-1335
    Schlagwort(e): Key words Conditional cancerogens ; Diterpene esters ; Euphorbia peplus ; Food chain ; Dietary cancer ; Milk polluted ; Skin irritants ; Tumor promoters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The hypothesis was proposed that there is a risk of dietary cancer from conditional cancerogens in produce of livestock polluted with irritants of the diterpene ester type, picked up by feeding on species of Euphorbiaceae ( spurge). To challenge this, several herbaceous plants of the genus Euphorbia, widespread as weeds and contaminants of livestock fodder, were identified botanically and extracts of their aerial parts were tested for irritancy on the mouse ear. As compared to a standard probe of croton oil, the extracts of E.␣peplus, E. nubica and E. helioscopia displayed irritancy. The most active extract (that from E. peplus) was investigated by a fractionation procedure monitored by the mouse ear assay, and five molecularly uniform irritant Euphorbia factors Pe1–Pe5 were identified as diterpene ester-type toxins. Together these factors comprise at least 11 ppm in the aerial parts. They were characterized individually to␣carry the diterpene parent alcohols ingenol, 20-deoxyingenol, and 20-deoxyingenol-6 α, 7α-epoxide. The irritancy of the aerial plant parts was shown to be caused mainly by the Euphorbia factors Pe1 and Pe2 together. Upon chronic administration of these irritants and hyperplasiogens as principal cancerogenic risk factors in the mouse skin initiation/promotion bioassay, Pe1 and Pe2 were established as tumor promoters. These findings together support the␣initial hypothesis and suggest the need for further investigations to determine whether there is a consequent risk of dietary cancer.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 124 (1998), S. 179-185 
    ISSN: 1432-1335
    Schlagwort(e): Key words Conditional cancerogens ; Risk of dietary cancer ; Diterpene esters ; Euphorbia peplus ; Food chain ; Lactating goats ; Polluted milk ; Poisoning by contaminated fodder ; Tumour promoters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Lactating goats were fed on aerial parts of the herb Euphorbia peplus L. admixed with their usual green fodder. During the experimental feeding period they showed symptoms of general poisoning. In necropsy the main toxic effects were seen in the heart, lung and liver. Histopathological examinations revealed that the primary toxic effects originated from degenerative changes in parenchymal and endothelial cells. Adverse symptoms in the liver and kidney were also reflected in an alteration of the levels of certain serum enzymes and of blood urea nitrogen. The milk of the goats fed on E. peplus, consumed by their young kids, caused poisoning and even death, with signs similar to those observed in the adult dams. These observations support the hypothesis that the poisoning observed in both milk-raised kids and mother goats is caused by diterpene ester type toxins present in the aerial parts of the herb contaminating the dams fodder. Generally, such skin irritant and hyperplasiogenic toxins are known to be highly active tumour promoters of skin and other organ, e.g. in mice. Lactating goats – as an important source of milk around the world – in a setting similar to that described, may provide a valid experimental etiological model for investigation of food polluted by tumour-promoting diterpene ester toxins.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 124 (1998), S. 301-306 
    ISSN: 1432-1335
    Schlagwort(e): Key words Conditional cancerogens ; Diterpene esters ; Euphorbia factors ; Food chain ; Metabolism of␣tumor promoters in goats ; Poisoning by contaminated fodder ; Pollution of goat's milk
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Special procedures were developed to investigate poisonous milk of lactating goats fed experimentally on aerial parts of the herb Euphorbia peplus L. In extracts of the milk, weakly irritant in the mouse-ear assay, three diterpene ester toxins were detected by techniques of high-performance liquid chromatography. They are of the ingenane structural type: Euphorbia␣factor Pel (ingenol 20-acetate 3-angelate), Euphorbia factor Pe2 (20-deoxyingenol 3-angelate) and Euphorbia factor␣Pe4 (20-deoxyingenol-6α,7α-epoxide 3-angelate). From goats milk collected 15 days after cessation of the experimental feeding period, extracts were completely free of diterpene ester toxins. The toxins polluting the milk are identical to diterpene ester entities occurring in the aerial parts of E. peplus. Of these, Euphorbia factors Pe1 and Pe2 are known as promoters of tumors of mouse skin. Apart from the toxic Euphorbia factors, the non-toxic parent alcohol ingenol was also detected in the milk. It is absent in the plant, and may have been generated metabolically from a certain portion of the toxic diterpene esters picked up by the goats from their fodder. The results presented here provide, for the first time, data for a novel interpretation of the locally high incidence of esophageal cancer observed in certain areas in the Caspian littoral of Iran, associated with a greater consumption of goat's (and sheep's) milk.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 25 (1953), S. 397-398 
    ISSN: 0009-286X
    Schlagwort(e): Chemistry ; Industrial Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Es wird ein einfaches Gerät beschrieben, das ein schonendes Eindampfen von Substanzfraktionen ohne Aufsicht und in kürzester Zeit ermöglicht.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 25 (1953), S. 505-509 
    ISSN: 0009-286X
    Schlagwort(e): Chemistry ; Industrial Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Es wird ein einfaches Verteilungselement und eine verbesserte Verteilungsbatterie beschrieben. Die entwickelten Apparaturen gestatten die Ausführung sämtlicher Verfahren der Gegenstromverteilung und haben sich bei der Trennung von Substanzgemischen zwischen 3 mg und 30 g bewährt. Ihr Anwendungsbereich wird an Hand von Verteilungskurven aufgezeigt.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 29 (1957), S. 23-24 
    ISSN: 0009-286X
    Schlagwort(e): Chemistry ; Industrial Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Die O'Keeffe-Verteilung (mehrmalige Substanzzugabe in der Mitte der Apparatur) ermöglicht die Trennung beliebig großer Substanzmengen für präparative Zwecke. Während früher für diese Art der Verteilung nur Scheidetrichter angewandt wurden, wird im folgenden die Arbeitsweise mit Hilfe einer der üblichen Verteilungs-Batterien beschrieben.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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