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Biomedical subjects

A Ciegler

Publications and source records attributed to A Ciegler.

At least 55 records · Page 3Linked to original sources

14C-Labeled aflatoxin B1 prepared with yeastlike cultures of Aspergillus parasiticus.

A simple method was developed to produce 14C-labeled aflatoxin B1 by using the yeastlike phase of Aspergillus parasiticus NRRL 2999. Yeastlike cultures resulted from absence of manganese in a synthetic medium. Sodium acetate-1-14C had a 0.22% average incorporation; sodium acetate-1,2-14C, 0.70%. The average yield of labeled B1 was 10 mg/500 ml medium with an average specific activity of either 63.3 mCi/mole (C-1 label) or 194.3 mCi/mole (C-1, 2 label).

Acetates↗

Co-identity of the refusal and emetic principle from Fusarium-infected corn.

The structure of vomitoxin isolated from Fusarium-contaminated corn was proved to be 3,7,15-trihydroxy-12,13-epoxytrichothec-9-en-8-one. This same toxin is responsible for the "refusal phenomenon" exhibited by swine fed contaminated corn. In addition, two new substances believed to be trichothecenes were isolated from naturally infected corn. Vomitoxin was also isolated from rice inoculated with F. graminearium NRRL 5883.

Animals↗

Teratogenicity of patulin and patulin adducts formed with cysteine.

The mean lethal dose of patulin for the chicken embryo injected in the air cell before incubation was determined to be 68.7 mug and that for the 4-day-old embryo was 2.35 mug. Both patulin (1 to 2 mug/egg) and the reaction mixture between patulin and cysteine (15 to 150 mug of patulin equivalents) were teratogenic to the chicken embryo. At least two ninhydrin-negative and four ninhydrin-positive products were formed during the latter reaction. Our explanation of the reaction mechanism remains to be elaborated.

Animals↗

Solid-substrate fermentor for ochratoxin A production.

A laboratory-scale fermentor designed for solid-substrate fermentation was constructed and tested. Its capacity to produce ochratoxin under varied conditions was determined with wheat as substrate. Ochratoxin yields of 2,000 to 2,500 mug/g of wheat were regularly obtained, and occasionally yields as high as 4,000 mug/g were obtained. The most critical factor in the fermentation was initial substrate moisture content; wheat tempered at 30 to 31% moisture produced the highest yields. Other variables tested were agitation and aeration rates, initial static culture time, and inoculum types and volumes.

Air↗

Mycotoxin-producing strains of Penicillium viridicatum: classification into subgroups.

Fifty-two isolates of Penicillium viridicatum Westling were divided into three groups based on ability to produce ochratoxin and/or citrinin, color, growth rate, type of growth, odor, and isolation source. Members of group I resemble one of the representative strains of P. viridicatum described in the literature; those belonging to group II differ from group I strains in several characteristics; group III is a heterogeneous series of highly variable isolates. Although three subgroupings can be recognized, retention of all isolates in the species P. viridicatum is deemed most appropriate at this time. Spore macerates of all isolates were examined for virus-like particles but none were detected.

Caproates↗

Isolation of the emetic principle from Fusarium-infected corn.

A mycotoxin responsible for vomiting in swine has been isolated from Fusarium-contaminated field corn. The compound was tentatively identified as a trichothecene, 3,7,15-trihydroxy-12,13-epoxy-trichothe-9-en-8-one, and has been given the trivial name vomitoxin.

Animal Feed↗

Studies of the toxicity of Helminthosporium maydis.

Isolates of Helminthosporium maydis from blighted corn were tested for toxicity in mice, rats, swine, rabbits, microorganisms, and tissue culture. Extracts of grains, mycelia, and culture supernatant fluids killed mice on intraperitoneal (ip) injection, but were nontoxic on administration by mouth to swine. The toxin was partially purified and appears to be a glycophospholipid. Histopathological examination revealed that the toxin acted as a severe irritant on ip injection, causing death in laboratory animals. In skin tests with rabbits, considerable exudation occurred, rather than necrosis.

Administration, Oral↗

Potential production and detoxification of penicillic acid in mold-fermented sausage (salami).

About 10% of 346 Penicillium cultures isolated from mold-fermented sausage synthesized the toxic metabolite penicillic acid on liquid media. Five of these producing cultures inoculated onto sausage failed to produce this toxin in up to 70 days of ripening. Several amino acids normally occurring in meat (cysteine, glutathione, arginine, histidine, and lysine) were found capable of readily reacting with penicillic acid. The adducts formed by the reaction between cysteine or glutathione with penicillic acid were identified and found to be non-toxic to mice, quails, and in the rabbit skin test but exhibited toxicity to the chick embryo. Hypotheses accounting for this residual toxicity are advanced.

Alkylation↗

Control of Penicillium martensii development and penicillic acid production by atmospheric gases and temperatures.

The effects of various gaseous environments and temperatures on development of Penicillium martensii NRRL 3612 and production of penicillic acid (PA) were determined. Accumulation of PA in mold-inoculated corn was measured following incubation under air; 20% CO(2), 20% O(2), 60% N(2); 40% CO(2), 20% O(2), 40% N(2); and 60% CO(2), 20% O(2), 20% N(2). Although reduced temperature initially inhibited PA production, at the end of the trial the largest quantity of PA (120 mug/g of corn) was found in air-incubated corn at the lowest test temperature (5 C). Atmospheres enriched with 60% CO(2) reduced PA accumulation below a detectable level at 5 and 10 C after a 4-week incubation period. Spore germination tests were carried out in a liquid growth medium incubated for 16 hr under several test conditions. Germ tube outgrowth at 30 C ranged from 36% in air to 2% in 60% CO(2), whereas no germination was observed in CO(2)-enriched gases at 10 C. When spore respiration rates were measured in air and O(2) in a liquid growth medium, complete removal of CO(2) from the reaction atmosphere did not reduce O(2) uptake.

Air↗