Solid phase extraction method for patulin in apple juice and unfiltered apple juice.
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Animals↗
Biomedical subjects
M W Trucksess
Publications and source records attributed to M W Trucksess.
Mycotoxin method evaluation. An introduction.
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Aflatoxins↗
Liquid chromatographic method for fumonisin B1 in sorghum syrup and corn-based breakfast cereals.
The fungus Fusarium verticillioides has been found on corn and sorghum, so it is possible that one or more of these toxins may be found in corn products such as breakfast cereals and syrup prepared from sorghum. Published methods when applied to syrups spiked with fumonisins gave low recoveries, less than 50%. A method was therefore developed which would be applicable to the syrup and breakfast cereals as well. Test samples were extracted with methanol-0.1 M sodium phosphate buffer (pH3) (1 + 1). The extract was diluted with water and applied to a 1 g C18 column. The column was washed with acetonitrile-water (2 + 8). Fumonisin B1 (FB1) was eluted with acetonitrile-trifluoroacetic acid (1000 + 1). The purified extract was evaporated and the toxin was derivatized with ophthaldialdehyde mercaptoethanol. The reaction mixture was resolved on a C18 liquid chromatographic column using acetonitrile-water-acetic acid (500 + 550 + 10.5) as the mobile phase at 37 degrees C, and FB1 measured with a fluorescence detector (excitation 335 nm, emission 440 nm). Recoveries of FB1 added to samples of sorghum syrup at levels ranging from 0.1 to 1.0 microgram/g were 94-132%. Recoveries of FB1 added to samples of breakfast cereal (corn flakes) at levels ranging from 0.2 to 1.6 micrograms/g were 96-100%. The method was applied to the analysis of 35 samples of sorghum syrup collected from 15 states in the US. One sample was found to contain FB1 at 0.12 microgram/g. A total of 32 samples of breakfast cereals collected by the Food and Drug Administration inspectors from grocery stores around the Kansas City area were analysed; no FB1 was found in the breakfast cereals (< 0.01 microgram/g). Results of this study indicated that FB1 possibly is not a problem in sorghum syrup and corn-based breakfast cereals in the US.
Biomarkers↗
Occurrence and distribution of Fusarium graminearum and deoxynivalenol in sweet corn ears.
Unusual wet and cool weather conditions during the 1994 growing season in Maryland and Delaware resulted in a severe outbreak of Fusarium graminearum on sweet corn ears ('Moore' variety) prior to harvesting and canning. The number of ears visibly infected with Fusarium spp. ranged from less than 5% to 25% in some fields. Infection typically occurred at the tassel end of the ears. Fusarium graminearum was isolated from surface disinfected kernels, both those which were visibly infected and those kernels which appeared disease-free in an area up to 5 cm from the edge of the visibly moulded areas. Infected ears were cut into four sections and the kernels only were analysed for deoxynivalenol (DON) using liquid chromatography (LC) and mass spectrometry/gas chromatography (GC/MS). Kernels from the visibly mouldy area of the ears contained DON at levels of approximately 446 mg/g DON on average; whereas in the non-visibly infected portion of the ears adjacent to the mouldy tips, DON levels averaged approximately 10 mg/g. Sections of ears closest to the base contained no detectable DON or less than 1 microgram/g. This is the first reported natural occurrence of the mycotoxin DON in sweet corn prior to harvest and canning.
Chromatography, Liquid↗
Effects of fumonisin B1 in pregnant rats.
Fumonisin B1 (FB1), the major mycotoxin from Fusarium moniliforme, has been implicated as a causative agent in several animal and human diseases. Despite animal toxicity studies and human epidemiological studies of FB1, knowledge of its reproductive effects is scarce. In this study, one of a series of proposed studies that will allow extrapolation to humans, pregnant rats were given oral doses of 0, 1.875, 3.75, 7.5 or 15 mg FB1/kg on gestation days 3 16. Caesarean sections were performed on day 17 or 20, and maternal condition, implantation efficiency, foetal viability and foetal development were measured. Dose-related decreases in overall feed consumption and body weight gain were seen, but only the feed consumption decrease at 15 mg/kg, and the decreased body weight gain at 15 mg/kg on days 0-17 were statistically significant. Foetal body weights at day 17 were similar in control and treated groups; but in day-20 foetuses, female weight and crown-rump length were significantly decreased at 15 mg/kg. FB1 was not teratogenic at the doses tested, and no dose-related effects were seen in either skeletal or soft-tissue development. In day-17 animals, maternal and foetal brain, liver and kidney tissues, and maternal serum were preserved to study the levels of sphinganine (Sa), sphingosine (So), and the Sa/So ratios. Dose-related increases were seen in Sa/So ratios in maternal livers, kidneys and serum. Sa/So ratios of maternal brains were not affected, nor were those of foetal kidneys, livers or brains.
Abnormalities, Drug-Induced↗
Effects of fumonisin B1 in pregnant rats. Part 2.
The developmental toxicity of purified fumonisin B1 (FB1), a mycotoxin from the common corn fungus Fusarium moniliforme, was examined in Charles River rats. Pregnant rats were dosed orally on gestation days 3-16 at 0, 6.25, 12.5, 25 or 50 mg FB1/kg body weight/day. FB1 was not teratogenic at the doses tested. At 50 mg/kg, maternal toxicity (inappetence, emaciation, lethargy, death, resorption of entire litters) and foetal toxicity (increased number of late deaths, decreased foetal body weight, decreased crown rump length, increased incidence of hydrocephalus, increased incidence of skeletal anomalies) were seen. The foetal toxicity observed at 50 mg/kg may be related to maternal toxicity. Histopathological evaluation of tissues from dams of control and all treated groups revealed dose-related toxic changes in kidney and liver tissues. Acute toxic tubular nephrosis was seen in kidneys from all treated groups. Hepatocellular cytoplasmic alteration and individual cellular necrosis of the liver was seen in the two high-dose groups. Sphinganine (Sa) and sphingosine (So) were measured in day-17 adult and foetal tissues. Dose related increases in Sa/So ratios were seen in maternal liver, kidney, serum and brain, but there was no effect on foetal liver, kidney and brain. These data suggest that FB1 does not cross the placenta and further suggest that the observed foetal toxicity is a secondary response to maternal toxicity.
Animals↗
High-performance liquid chromatographic determination of 1,1'-ethylidenebis(L-tryptophan) in L-tryptophan preparations.
In studies to determine the cause or causes of the eosinophilia myalgic syndrome (EMS) and to monitor the purity of L-tryptophan preparations, an HPLC method has been developed for determining 1,1'-ethylidenebis(L-tryptophan) (EBT) in L-tryptophan (W) preparations. The W preparations are extracted with 0.1% trifluoroacetic acid (TFA) and filtered, and the EBT is purified by passage through a Sep-Pak C18 cartridge. The cartridge is washed with water and 6% acetonitrile in water, and EBT is eluted with methanol. The water-diluted eluate is then chromatographed on a silica-based, reversed-phase HPLC column with a gradient of water and 80% acetonitrile, both solvents containing 0.1% TFA. EBT absorbance is measured at 280 nm. The average recovery of EBT from L-tryptophan powder, spiked over the range 1.2-4.8 micrograms/g, was 91%. The limit of determination was approximately 0.6 micrograms/g. Sixteen test samples of W products manufactured by the company to which most of the cases of EMS have been traced contained > 70 micrograms of EBT/g. Three nonpatient-related test samples either did not contain EBT or contained < 2 micrograms of EBT/g.
Buffers↗
An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan.
OBJECTIVE: To determine whether L-5-hydroxytryptophan (L-5-HTP) associated with eosinophiliamyalgia syndrome (EMS) like illness contains impurities in a fashion similar to that described in L-tryptophan associated with EMS. METHODS: Members of a family who became ill after exposure to L-5-HTP were evaluated at the National Institutes of Health. Data from patients with extended exposure to L-5-HTP were also examined. Samples of L-5-HTP were examined using high performance liquid chromatography. RESULTS: One member of the family had EMS, and 2 others had eosinophilia. No patient in the other group reviewed developed the syndrome, although 2 patients developed eosinophilia. The L-5-HTP used by the family contained an impurity not present in samples from the other patient group. After replacement with L-5-HTP not containing this impurity, eosinophilia in 2 family members resolved. CONCLUSION: Some L-5-HTP contains impurities that may be related to L-5-HTP associated EMS.
5-Hydroxytryptophan↗
Separation and isolation of trace impurities in L-tryptophan by high-performance liquid chromatography.
A high-performance liquid chromatographic (HPLC) profiling method was developed to separate trace impurities in L-tryptophan products associated with the eosinophilia-myalgia syndrome (EMS) epidemic. The test portion was dissolved in water, and the solution was filtered and chromatographed on a silica-based C18 reversed-phase HPLC column by using linear gradient elution with water and acetonitrile-water (80:20); both solvents contained 0.1% trifluoroacetic acid for ion-pairing. The method was used to profile 200 test samples from six manufacturers of L-tryptophan. The method was modified to include the use of a C18 disposable cartridge to retain the 1,1'-ethylidene-bis(L-tryptophan) (peak E, peak 97 or EBT), the impurity most strongly associated with EMS, and to remove the L-tryptophan before HPLC separation and quantitation. Recoveries of EBT added to test portions (2 micrograms/g and above) averaged 80%.
Chromatography, High Pressure Liquid↗
Pathological and immunological effects of ingesting L-tryptophan and 1,1'-ethylidenebis (L-tryptophan) in Lewis rats.
The eosinophilia-myalgia syndrome (EMS) has been associated with ingestion of L-tryptophan (L-TRP) produced by a single manufacturer. Epidemiological data implicated 1,1'-ethylidenebis (L-tryptophan) (EBT) (peak 97 or peak E) as a possible etiologic agent. We showed previously that Lewis rats treated with the L-TRP implicated in EMS develop fasciitis and perimyositis similar to those seen in human EMS. We now report the pathology associated with the treatment of Lewis rats with synthetic EBT and/or L-TRP. All animals treated for 6 wk with case-associated L-TRP or EBT developed significant myofascial thickening, compared with animals in the vehicle control and control L-TRP groups. However, even those animals receiving the control L-TRP showed a mild but significant increase in the thickness of the myofascia, compared with vehicle-treated control animals. All animals except vehicle controls also exhibited significant pancreatic pathology, including fibrosis and acinar changes. Only animals treated with case-associated L-TRP for 6 wk showed evidence of immune activation with increased frequency of CD8, Ia, and IL-2 receptor-positive cells in the peripheral blood. Animals receiving L-TRP or EBT for < 6 wk did not show significant differences in myofascial thickness, although these animals did show pancreatic acinar changes. Although these results demonstrate for the first time the pathological effects of EBT, they do not rule out the possibility that other impurities in the EMS-case-associated L-TRP may also contribute to some of the features of EMS.
Animals↗
Determination of aflatoxins in food products by chromatography.
Several chromatographic methods for the determination of aflatoxins in agricultural and food products are reviewed. During the past two decades, identification and determination of aflatoxins were done by thin-layer chromatography (TLC) because it was easy, fast and inexpensive. However, high-performance liquid chromatography (HPLC) using fluorescence detection is now the method of choice for determining aflatoxins and is also growing in popularity for their identification. The reasons for selecting HPLC over TLC can be summarized as the ability to analyze for a wide variety of compounds, including compounds that are easily degraded by heat, light or air, the ease of adaptation to confirmatory procedures, the potential for automation and the dramatic improvement in instrumentation, including the development of increasingly sensitive fluorescence and electrochemical detectors and short, high-resolution, reversed-phase columns.
Aflatoxins↗
Polymerase chain reaction identification of Vibrio vulnificus in artificially contaminated oysters.
DNAs extracted from Vibrio vulnificus seeded into oyster homogenates were evaluated as templates for the polymerase chain reaction. Several extraction procedures were examined, and it was determined that DNA recovered from cells lysed by guanidine isothiocyanate, extracted with chloroform, and precipitated with ethanol was most suitable for use as a polymerase chain reaction template. The region targeted was a 519-bp portion of the cytotoxin-hemolysin gene of V. vulnificus. This region was amplified only when DNA from this species was present in the homogenate. V. vulnificus seeded into oyster homogenates at an initial level of 10(2) CFU/g of oyster meat was consistently observed after 24 h of incubation in alkaline peptone water.
Animals↗
Synthetic oligonucleotide probes complementary to the HLA-B variable region hybridize with Klebsiella pneumoniae.
Three oligonucleotide probes complementary to base sequences of the HLA-B variable region were used to probe clinical and foodborne isolates of Klebsiella spp. by DNA colony hybridization. One oligonucleotide (RR-3) corresponding to amino acid residues 66-74 of the HLA-B27.1 sequence and one corresponding to residues 66-74 of the HLA-B7 sequence (RR-5) hybridized with K. pneumoniae under conditions of high stringency. A genomic library was constructed using K. pneumoniae K43 chromosomal DNA, and a 1 kb PstI restriction fragment was found to contain the sequence associated with specific binding of the oligonucleotide probes. After purification and radiolabeling, the cloned fragment hybridized with 96.2% of the K. pneumoniae isolates by DNA colony hybridization. These results confirm the presence of sequence similarities between bacterial DNA and the MHC Class I variable region.
Antigens, Bacterial↗
Synthetic oligodeoxyribonucleotide probes for detection of Listeria monocytogenes.
A 500-base-pair DNA fragment of a presumptive beta-hemolysin gene of Listeria monocytogenes has been used to identify this organism by a modified colony hybridization technique. We have cloned this DNA fragment into M13 bacteriophage vectors and sequenced it by a dideoxynucleotide sequencing technique. From this sequencing information, several oligodeoxyribonucleotides were synthesized and used as synthetic probes to identify L. monocytogenes. The probes were specific for L. monocytogenes and did not react with any other Listeria strains in a colony hybridization assay. In particular, one of these probes (AD07) was used to detect L. monocytogenes in artificially contaminated raw-milk and soft-cheese samples.
Base Sequence↗
Aflatoxicol and aflatoxins B1 and M1 in eggs and tissues of laying hens consuming aflatoxin-contaminated feed.
This study was undertaken to relate quantitatively the aflatoxin residue found in eggs and tissues to the aflatoxin intake via feed. Eighteen hens were fed an aflatoxin B1 (B1)-contaminated feed (8 micrograms/g) for 7 days, after which half the group was sacrificed; the remainder were sacrificed after an additional 7 days on an aflatoxin-free diet. Eggs were collected over the entire 14-day period. Aflatoxicol (R0), B1, or both were found in eggs and tissues (kidneys, liver, muscle, blood, and ova). Aflatoxin M1 (M1) (.04 to .1 ng/g) was found only in the kidneys. Levels of R0 and B1 were approximately the same in eggs, ova, kidneys, and liver. In eggs, the levels of R0 and B1 (.02 to .2 ng/g) increased steadily for 4 or 5 days, after which time the levels plateaued and then decreased after B1 withdrawal at the same rate as they had increased. At 7 days after withdrawal, only trace amounts of R0 (.01 ng/g) remained in eggs. All tissues, except blood, from hens sacrificed immediately before aflatoxin withdrawal contained R0 (.04 to .4 ng/g) or R0 and B1 (.04 to .8 ng/g). The R0 (.03 to .11 ng/g) was the only aflatoxin detected in muscle, and B1 (.05 to .07 ng/g) was the only aflatoxin in blood. Seven days after aflatoxin withdrawal, B1 (.08 ng/g) was found in one of nine livers and R0 (.01 to .04 ng/g) in eight of nine muscles analyzed, but no aflatoxins were found in any other tissues.
Aflatoxin B1↗
Absorption and distribution patterns of aflatoxicol and aflatoxins B1 and M1 in blood and milk of cows given aflatoxin B1.
Two 600-kg lactating cows were each given a single oral dose (0.5 mg/kg of body weight) of aflatoxin B1 (B1). Samples were obtained at postdosing hours 0, 1, 2, 3, 4, 6, 8, 10, and 12 and thereafter every 12 hours for 10 days. Aflatoxicol (Ro), B1, and aflatoxin M1 (M1) were found in the milk, plasma, and RBC of both cows at postdosing hour 1. Maximum concentrations of the toxins were observed at 12 and 60 hours. The ratio of the concentrations for Ro, B1, and M1 was approximately 1:10:100. Both cows had clinical signs of distress at 24 hours; 1 cow died at 60 hours and the other cow recovered within 4 days. In the samples of liver, kidney, urine, bile, and rumen contents of the cow that died, the B1 concentrations were 5.1, 3.3, 4.1, 1.6, and 320 ng/g, respectively, and the M1 concentrations were 4.3, 20, 37, 16, and 8.6 ng/g. The Ro concentrations in the kidney were approximately equal to that of B1; however, liver, urine, bile, and rumen contents concentrations were 0.88, 0.10, 0.36, and 4.9 ng/g, respectively.
Aflatoxin B1↗
Aflatoxicol and aflatoxins B1 and M1 in the tissues of pigs receiving aflatoxin.
Aflatoxicol (AFL) and aflatoxins B1 and M1 were found in tissues (kidney, liver, and muscle) of feeder pigs given an estimated LD50 oral dose of B1 (1.0 mg/kg body weight) provided as a rice culture of Aspergillus flavus and of market-weight pigs fed a naturally contaminated feed, containing aflatoxin B1 at a level of 400 ng/g from corn, for 14 days. The residues in all tissues decreased with time after treatment in both groups, with no detectable residues (approximate detection limits, ng/g, B1 0.03, M1 0.05, AFL 0.01) in pig tissues from the feeding experiment 24 h after withdrawal of aflatoxin-contaminated feed. B1 and M1, when found in the feeding experiment, were at about the same levels in all tissues except the kidney, in which M1 was the dominant aflatoxin. The level of AFL, when detected, was about 10% of the B1 level.
Aflatoxin B1↗
Microbial hazards associated with bean sprouting.
The behaviour of microorganisms was studied in mung beans and alfalfa seeds before and after germination in modified, commercially available bean-sprouting kits. The microorganism were enumerated by the aerobic plate count (APC) and by total yeast and mold count procedures. Salmonella species were artificially inoculated into selected samples and were enumerated by the most probable number (MPN) method. After germination of the beans or seeds into mature sprouts, significant increases were noted in APCs and in MPN values of Salmonella species. Although counts of yeasts and molds did not increase significantly after germination, these samples show an increase in toxic Aspergillus flavus and potentially toxic Alternaria species. The presence of toxic Penicillium cyclopium molds also increase substantially in 5 samples of a single brand of mung beans. Analysis of selected sprout samples, however, showed no presence of aflatoxin.
Aflatoxins↗