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Biomedical subjects

C M Christensen

Publications and source records attributed to C M Christensen.

At least 73 records · Page 4Linked to original sources
PubMed1972

Effects on turkey poults of rations containing corn invaded by Fusarium tricinctum (Cda.) Sny. & Hans.

Consumption of an otherwise balanced ration containing 1% of corn invaded by Fusarium tricinctum isolate 2061-C resulted in the death of 13% of turkey poults within 35 days, in decreased feed efficiency and weight gain, and moderate development of bilateral necrotic lesions at angles of the mouth, especially in those that succumbed. Consumption of a ration with 2% of corn invaded by F. tricinctum resulted in death of 60 to 83% of the birds, in greatly reduced growth and feed efficiency in the survivors, and in development of severe mouth lesions. Consumption of rations containing 5, 10, and 20% of corn invaded by the fungus resulted in death of all birds in 5 to 15 days.

Animal Feed↗
PubMed1972

Effect on young swine of consumption of rations containing corn invaded by Fusarium roseum.

Both male and female pigs given a ration containing corn invaded by Fusarium roseum, in amounts sufficient to provide 500 to 600 ppm of F-2, for the first 64 days of the test and which for another 60 days were given a commercial pig ration were much lower in weight than the controls which were given a commercial pig ration throughout. In relation to the weight of the animals, in the pigs receiving the ration containing F-2, the weight of the uterine horn of the gilts was much greater and the weight of the testes of the males was much less than the weight of the same organs of the controls.

Animal Feed↗
PubMed1972

Tenuazonic acid, a toxic produced by Alternaria alternata.

Fifty-seven of 87 isolates of Alternaria alternata (Fr) Keissler grown on autoclaved, moist corn-rice substrate and fed to rats were lethal. The major toxin produced was isolated and characterized as tenuazonic acid. Twenty of 23 toxigenic Alternaria isolates examined produced tenuazonic acid. No tenuazonic acid could be detected in either of the field samples of sorghum or blackeyed peas, which were heavily invaded by Alternaria.

Acetates↗
PubMed1971

Filamentous fungi and bacteria in macaroni and spaghetti products.

Filamentous fungi, especially Aspergillus flavus-oryzae, and bacteria were present in all samples of macaroni and spaghetti products tested. No aflatoxin was detected in the three samples, all relatively high in A. flavus-oryzae, that were tested for it. Five of the nine isolates of A. flavus-oryzae from macaroni and sphaghetti grown in corn, incorporated into an otherwise balanced ration, and given to ducklings resulted in death of one to five ducklings within six days.

Aflatoxins↗
PubMed1967

Estrogenic metabolite produced by Fusarium graminearum in stored corn.

A derivative of resorcinylic acid, produced by the fungus Fusarium graminearum, has been found to be responsible for the estrogenic signs in swine and laboratory rats. An estrogenic response in rats can be incited by injecting intramuscularly as little as 20 mug of the estrogen (F-2). Stimulation in growth of rats was noted at the lower concentrations (20 to 40 mug) of a series. Up to 3,500 ppm of the estrogen was produced on a solid corn medium. The compound is relatively stable to heat and ultraviolet irradiation. Methods of analysis have been developed and include: extraction procedures, evaluations by ultraviolet absorption spectrophotometry, thin-layer chromatography, and gas-liquid chromatography.

Animals↗
PubMed1967

Microflora of black and red pepper.

Dilution cultures of 30 samples of ground black pepper yielded an average of 39,000 colonies of fungi per g, with a range of 1,700 to 310,000 per g. Total numbers of colonies of bacteria from 11 samples averaged 194,000,000 per g, with a range from 8,300,000 to 704,000,000 per g. A variety of fungi grew from nearly all surface-disinfected whole peppercorns that were cultured. Thirteen samples of ground red pepper from the United States yielded an average of 1,600 colonies of storage fungi per g and an equal number of other fungi; five samples from India yielded an average of 78,900 colonies of storage fungi per g and 169,400 colonies of other fungi per g. Among the fungi from both black and red pepper were Aspergillus flavus and A. ochraceus, some isolates of which, when grown for 8 to 10 days on moist autoclaved corn and fed to white rats or to 2-day-old Pekin ducklings, were rapidly lethal to them. Aflatoxin B(1) was isolated from one of the samples of corn on which A. flavus from black pepper was grown. Among the bacteria isolated from ground black pepper were Escherichia coli, E. freudii, Serratia sp., Klebsiella sp., Bacillus sp., Staphylococcus sp., and Streptococcus sp. No cultures of Shigella or Salmonella were found.

Aflatoxins↗
PubMed1966

Toxicity to rats of corn invaded by Chaetomium globosum.

Of 53 isolates of Chaetomium globosum Kunze isolated from corn, manufactured feed, and fiberboard, grown on autoclaved corn, and fed to rats, 25 were lethal within 4 to 6 days. Thirty-six single ascospore cultures of one isolate were uniformly lethal when similarly grown and fed to rats. Incubation of the fungus on corn for 6 to 8 weeks resulted in greater toxicity than shorter incubation times. Premortem symptoms indicated damage to the central nervous system of the affected animals, and postmortem lesions included hemoglobinuria, hemorrhagic enteritis, and subdural hemorrhaging. Corn invaded by C. globosum and toxic to rats had no detectable effects on swine when fed as their sole ration for 6 weeks, and appeared to be consumed with relish. The toxic substance was best obtained by defatting the fungus-invaded corn with petroleum ether (bp, 60 to 70 C), extraction with acetone, and further purification by elution from a silica gel column with acetone and 5% acetone in chloroform.

Animals↗