Kohichiro Ohtsubo

Cytotoxicity of new cytochalasans fromChaetomium globosum

Nachweis, dass CHCl3-Rohextrakte aus Myzelien und Filtraten der Zuchtmedien vonChaetomium globosum Kunze ex Fries einen akuten toxischen Effect auf HeLa-Zellen in vitro, sowie auf Mäuse zeigten. Chaetoglobosine die aus Mycelium-Rohextrakt isoliert wurden und chemisch zu den Cytochalasanen gehören, induzierten in HeLa-Zellen eine Polynukleierung und multipolare Kernverteilung. Auch beim Chaetogobosin wird eine Mikrofilament-Schädigung angenommen.

High incidence of hepatic tumours in rats fed mouldy rice contaminated with Aspergillus versicolor containing sterigmatocystin.

Abstract The hepatocarcinogenicity of rice contaminated with Aspergillus versicolor was investigated by feeding two groups of male Donryu rats on a mouldy-rice culture added to the diet in an amount to provide 5 or 10 ppm sterigmatocystin, equivalent to a daily intake of 75 or 150 μg/rat. Of the 13 rats in each test group that died between day 465 (when the first animal with a tumour died) and day 709 (when survivors were killed), 12 of those fed 10 ppm sterigmatocystin and 11 fed 5 ppm developed hepatic tumours, mostly hepatocellular carcinomas. Three haemangiosarcomas were also observed. In view of the high incidence of hepatomas following ingestion of very low levels of sterigmatocystin, increased surveillance of this toxin in feeds and foodstuffs is recommended.

Hypertrophy of pulmonary arteries and arterioles with cor pulmonale in rats induced by seneciphylline, a pyrrolizidine alkaloid

Seneciphylline, one of the hepatotoxic pyrolizidine alkaloids, induced, as do also monoclotaline, etc., a marked arterial and arteriolar hypertrophy of the lung of young Wistar rats a month after a single s. c. injection of 50–80 mg/kg. Cor pulmonale with leftward shift of the ventricular septum was also noted.

Toxic metabolites of Aspergillus candidus

Zwei neue Toxine wurden aus den Mycelien und dem Zuchtmedium eines Schimmelpilzes,Aspergillus candidus, sowie aus dem experimentell mit demselben Pilz verschimmelten polierten Reis isoliert. Die beiden Substanzen sind sowohl chemisch als auch toxikologisch voneinander völlig verschieden.

Field Survey of Mycotoxin-Producing Fungi Contaminating Human Foodstuffs in Japan, with Epidemiological Background

Approximately 250 strains selected from 2940 strains of fungi isolated as food contaminants were assayed for their toxic effects on cultured cells and animals.