PubMed Health⌕ Search

Biomedical subjects

A E Pohland

Publications and source records attributed to A E Pohland.

At least 19 recordsLinked to original sources
PubMed1996

Occurrence of fumonisins in the U.S. food supply.

Over the past several years a great deal of interest has been shown in assessing human exposure to the fumonisins. This interest, of course, arises as a result of the finding of fumonisins in foods and the expanding data base on toxicological effects, both acute and sub-acute. The basis for exposure assessment lies in surveys of foods as well as a knowledge of consumption patterns. An overview of such surveys, limited as they are, will be presented along with some evaluation of the methodology used.

Carcinogens, Environmental↗
PubMed1995

Chemical studies of phytoestrogens and related compounds in dietary supplements: flax and chaparral.

High-performance liquid chromatographic (HPLC) and mass spectrometric (MS) procedures were developed to determine lignans in flaxseed (Linum usitatissimum) and chaparral (Larrea tridentata). Flaxseed contains high levels of phytoestrogens. Chaparral has been associated with acute nonviral toxic hepatitis and contains lignans that are structurally similar to known estrogenic compounds. Both flaxseed and chaparral products have been marketed as dietary supplements. A mild enzyme hydrolysis procedure to prevent the formation of artifacts in the isolation step was used in the determination of secoisolariciresinol in flaxseed products. HPLC with ultraviolet spectral (UV) or MS detection was used as the determinative steps. HPLC procedures with UV detection and mass spectrometry were developed to characterize the phenolic components, including lignans and flavonoids, of chaparral and to direct fractionation studies for the bioassays.

Butylene Glycols↗
PubMed1984

Myelotoxicity and macrophage alteration in mice exposed to ochratoxin A.

Six- to seven-week-old female B6C3F1 mice were administered a total of 0, 20, 40, or 80 mg/kg of ochratoxin A (OCT A) ip on alternate days over an 8-day period. Twenty-four hours following the final dose, histopathology, bone marrow, and macrophage parameters were assayed. There was a dramatic dose related decrease in thymic mass with the mean thymus weight of the high dose animals being only 33% of controls. Histologic evidence of nephrotoxicity was minimal and restricted to the inner cortex. Myelotoxicity was present as evidenced by bone marrow hypocellularity, decreased marrow pluripotent stem cells (CFU-S), granulocyte-macrophage progenitors (CFU-GMs), and decreased 59Fe uptake in marrows and spleens of exposed mice. Peritoneal macrophages from sc as well as ip injected mice demonstrated increased phagocytic capacities and increased capacity to inhibit tumor cell growth. These alterations in bone marrow cells and macrophages suggest myelotoxicity is an additional potential hazard of OCT A exposure.

Animals↗
PubMed1984

Poisonous plants contaminating edible ones and toxic substances in plant foods. Part 3. Pyrrolizidine alkaloids from Heliotropium digynum Forssk. (= H. luteum, Poir.).

Investigation of the alkaloidal constituents of Heliotropium digynum resulted in the isolation of four alkaloids viz. heliotrine, europine, lasiocarpine and 7-angelylheliotrine. Moreover, HPLC and GLC showed the probable presence of heliotridine and some other unidentified minor constituents. A summary of the pharmacotoxicity and biological activity of the ethanolic extract, total alkaloids with special reference to heliotrine is presented.

Animals↗
PubMed1981

Development of a sensitive high-performance liquid chromatographic method for detection of aflatoxins in pistachio nuts.

A very sensitive method is described for the detection of aflatoxins in pistachio nuts. The method employs the extraction procedure used in the BF method (described in the Association of Official Analytical Chemists' Book of Methods) followed by an acid alumina column clean-up to remove sample components which would otherwise interfere in the final determinative step. The quantitation of the aflatoxins is carried out by high-performance liquid chromatography on a C18 reversed-phase column after conversion of aflatoxins B1 and G1 to their more fluorescent derivatives, B2a and G2a. The limit of detection was found to be 0.5 microgram/kg. The chromatograms were found to be free of interfering peaks and multiple injections showed excellent reproducibility.

Aflatoxins↗
PubMed1980

Determination of roquefortine in blue cheese and blue cheese dressing by high pressure liquid chromatography with ultraviolet and electrochemical detectors.

A method is described for the determination of roquefortine in blue cheese and blue cheese dressing. The method involves sample extraction with ethyl acetate, cleanup by liquid-liquid partition, and determination by high pressure liquid chromatography with ultraviolet and electrochemical detectors connected in series. Recoveries of roquefortine added to cheese at levels of from 16 to 320 ng/g averaged 74.9%. This method was applied to the analysis of 12 samples of blue cheese and 2 samples of blue cheese dressing, all of which were produced in the United States; roquefortine was found in all of the samples at average levels of 424 ng/g for the blue cheese and 45 ng/g for the blue cheese dressing.

Cheese↗
PubMed1977

Isolation and identification of xanthomegnin, viomellein, rubrosulphin, and viopurpurin as metabolites of penicillium viridicatum.

Four of the metabolites of Penicillium viridicatum 66-68-2 grown on rice cultures were isolated and identified as xanthomegnin, viomellein, rubrosulphin, and viopurpurin. Melting points, elemental analysis, and infrared, ultraviolet, and field desorption and electron impact mass spectra of the isolated compounds were consistent with values reported in the literature for these compounds. In addition, diacetate and triacetate derivatives were prepared, and the chemical and physical analyses of the derivatives were also consistent with literature data. Proton magnetic resonance spectroscopy and thin-layer chromatography were also used for the additional identification of selected compounds.

Chemical Phenomena↗
PubMed1977

Studies concerning the metabolites produced by Stachybotrys atra, Penicillium islandicum, Penicillium viridicatum and Aspergillus versicolor.

Over the past ten years it has become quite apparent that mycotoxins, or toxins produced by fungi, are responsible for a wide variety of human and animal illnesses and, in many cases, deaths. Consequently, the study of the metabolites produced by fungi and the possible occurrence of such metabolites in foodstuffs is of critical importance. It is the purpose of this paper to outline the approach taken at the U.S. Food and Drug Administration in evaluating the possible hazard to human health posed by the growth of molds on foods, and to elaborate upon the results of studies sponsored by FDA relative to the metabolites produced by four mold species frequently found on foodstuffs. i.e., S. atra, P. islandicum, P. viridicatum and A. versicolor.

Aspergillus↗
PubMed1977

Aflatoxin in Tunisian foods and foodstuffs.

1076 samples of different commodities were screened for aflatoxin contamination. Samples were taken from storage houses and dealers throughout the country. 14 of these samples contained aflatoxin (as much as 62 microgram/kg). Corn was found to be the most contaminated agricultural product followed by sorghum and peanuts. Wheat and barley showed no contamination. 1 out of 19 pistachio samples contained 22 microgram/kg of aflatoxin B1. Fluid milk showed no contamination while only 2 out of 248 cheese samples were found contaminated with aflatoxin M1 (10.6 microgram/kg).

Aflatoxins↗
PubMed1977

Aflatoxin in Tunisian aleppo pine nuts.

Twenty-six of 50 Aleppo pine nuts samples collected throughout Tunisia showed relatively high levels of contamination by aflatoxin. Some samples contained as much as 2000 ppb aflatoxin B1, and very few contained less than 100 ppb. Total aflatoxins as high as 7550 ppb were found. A traditional pudding, widely consumed in Tunisia, which was prepared from contaminated nuts still contained more than 80% of the aflatoxin originally present in the nuts.

Aflatoxins↗
PubMed1976

Determination of sterigmatocystin in corn and oats by gel permeation and high-pressure liquid chromatography.

Corn and oats samples are extracted with acetonitrile-water, followed by partition of the extract against hexane, transfer to chloroform, and elution from a silica gel column. The extract is purified by gel permeation chromatography on an automatic instrument. Reverse phase high-pressure liquid chromatography, using a 254 nm ultraviolet detector and 0.1 M KH2PO4-acetonitrile (7+5) as the mobile phase, is used for quantitation. The average recovery from 6 samples of corn to which 0, 25, 50, and 100 mug sterigmatocystin/kg had been added was 59%, with a coefficient of variation of 8.4%. The average recovery from oats fortified at the same levels was 74%, with a coefficient of variation of 12%. A confirmation procedure based on hemiacetal derivative formation on a thin layer chromatographic plate is also described.

Chromatography, Gel↗
PubMed1975

Collaborative study of a method for chemical confirmation of the identity of aflatoxin.

The chemical method for confirmation of the identity of aflatoxin by derivative formation directly on the TLC plate was studied collaboratively by 8 participants. The results show that aflatoxin B-1 was confirmed in 17 of 17 sample extracts representing 15 mu-g aflatoxin B-1/kg peanut butter, in 13 of 16 extracts representing 5 mu-g/kg, and in none of the 7 aflatoxin-free extracts. Collaborators commented that the method was easily performed and gave good results. The method has been adopted as official first action.

Aflatoxins↗