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At least 1,099 records · Page 61Linked to original sources
PubMed1994

Inhaled mycotoxins lead to acute renal failure.

Mysterious deaths of archeologists after opening Egyptian tombs have been suspected, but never proved, to be secondary to inhalation of mycotoxin. We observed a case of acute renal failure (ARF) due to inhalation of ochratoxin A produced by a mould of the species Aspergillus ochraceus. After working 8 h in a granary closed for several months, a farmer and his wife suffered respiratory distress; the woman developed non-oliguric ARF and biopsy revealed tubulonecrosis. A strain of Aspergillus ochraceus producing ochratoxin was isolated from the wheat.

Acute Kidney Injury↗
PubMed1994

The mycotoxin ochratoxin-A impairs protein uptake in cells derived from the proximal tubule of the kidney (opossum kidney cells).

Proximal tubule-derived opossum kidney (OK) cells are a suitable model to study proximal tubular protein endocytosis by using fluorescein-isothiocyanate-albumin as substrate. We used OK cells to investigate several steps of the endocytotic process in control cells and in ochratoxin A (OTA)-treated cells. OTA is a mycotoxin which causes proteinuria. When OTA was present only during the 15-min period in which uptake was studied, it had no effect on albumin endocytosis. Preincubation of OK cells with OTA (10 mumol/l) for 24 hr led to a reduction of transport capacity (Jmax to approximately 50% of control) and of apparent affinity (Km to approximately 200% of control). Specific binding of albumin to the apical cell surface was reduced also. Maximum binding capacity was reduced to 72% of control. By contrast, endocytotic uptake of the fluid-phase marker dextran was not affected by OTA. Preincubation of OK cells for 24 hr with 10 mumol/l of OTA reduced degradation of fluorescein-isothiocyanate-albumin to trichloroacetic acid-soluble fluorescence to 59% of control. We could not detect any difference in endosomal pH (6.13 +/- 0.05 in controls vs. 6.04 +/- 0.10 in OTA-treated cells). Furthermore, the rate of re-exocytosis of albumin taken up was significantly greater in OTA-treated cells. We conclude that: 1) OK cells are a suitable model to study several steps of the endocytotic process separately and thus to investigate the pathophysiology of reduced tubular protein reabsorption and 2) 24-hr exposure to OTA reduces protein uptake because of a decrease of specific binding sites and of enhanced exocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMedDate not supplied

Analysis of trichothecene mycotoxins in contaminated grains by gas chromatography/matrix isolation/Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry.

Gas chromatography/matrix isolation/Fourier transform infrared (GC/MI/FTIR) spectroscopy and GC/mass spectrometry (MS) were used to confirm the identities of trimethylsilyl (TMS) derivatives of trichothecene mycotoxins in naturally contaminated grains. Infrared spectral bands observed in the fingerprint region were unique for 10 trichothecene standards. Characteristic absorption bands were observed for the ester (near 1750 cm-1) and ketone (near 1700 cm-1) carbonyl stretching vibrations, the acetate CH3 symmetric bend (1370 cm-1), the epoxide ring (1262 cm-1), the trimethylsilyl CH3 in-plane deformation (1253 cm-1), the ester (O)C-O asymmetric stretching vibration (near 1244 cm-1), and several other bands including intense features due to the TMS function. Infrared bands observed under cryogenic matrix isolation conditions were compared with those found at room temperature in a potassium bromide matrix for 5 of these standards. Identities of deoxynivalenol (DON) from barley and mixed feed, nivalenol from wheat and barley, and DON and fusarenon-x from sweet corn were confirmed by comparison of their infrared spectral bands with those of standards. The identity of DON in the same test samples of sweet corn was confirmed further by GC/MS. GC/MS was also used to quantitate the levels of DON (67-455 ppm) in sweet corn test samples.

Chromatography, Gas↗
PubMedDate not supplied

Assessment of immunochemical methods for the analysis of trichothecene mycotoxins in naturally occurring moldy corn.

The efficacy of various immunochemical methods for simultaneous analysis of different trichothecene mycotoxins in corn samples naturally contaminated with various Fusarium molds was evaluated. Antibodies against either T-2 tetraol tetraacetate (T-2-4ol-4Ac) or deoxynivalenol triacetate (Tri-Ac-DON) were used in the enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) for total type A and total DON-related trichothecenes (TCTCs), respectively. Specific antibodies against T-2 toxin were used in an RIA for analysis of T-2 toxin alone. Analytical recoveries of T-2 toxin analyzed as T-2-4ol-4Ac by ELISA and T-2 toxin by RIA at 10-200 ppb were 83.5-123% and 81.8-110.6%, respectively. T-2 toxin accounts for about 30% of total type A TCTCs by both liquid chromatography (LC)-ELISA and RIA methods. The correlation coefficients (r) of total type A TCTC levels versus T-2 toxin level by RIA was 0.725 (p < 0.0001). A good correlation (r = 0.84 and p = 0.04) also was found for T-2 toxin levels obtained by LC-ELISA and RIA methods. In addition to T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and T-2 tetrol were found in samples containing high levels of type A TCTCs by LC-ELISA. For analysis of DON alone, samples were treated with a Sep-Pak C18 cartridge to remove other acetylated DONs before RIA. Recovery of DON after the C18 cartridge treatment was 90%. Overall analytical recoveries of DON as Tri-Ac-DON (sample with no C18 treatment) and DON alone (with C18 treatment) at 10-500 ppb were 81.3-94% and 72.7-104%, respectively. RIA revealed that DON accounts for about 50% of total DON-related TCTCs. The coefficient of correlation between total DON-related TCTCs and DON levels was 0.84 (p < 0.0001).

Chromatography, Liquid↗
PubMed1998

[Effect of dietary selenium on the activity of UDP-glucuronosyltransferases and metabolism of mycotoxin deoxynivalenol in rats].

The influence of selenium excess and deficiency on the activity of xenobiotic metabolizing enzymes and the metabolism of mycotoxin deoxynivalenol (DON) in rats was studied. Wistar male rats were fed for 6 weeks semi-synthetic diets containing 0.2, 1.0 or 5.0 ppm selenium. For induction of selenium deficiency the weanling rats were fed for 6 weeks diet containing < or = 0.02 ppm selenium. The activity of selenium-dependent glutathione peroxidase was reduced in the liver of selenium-deficient rats by 93% at 42 days. DON, its de-epoxy metabolite DOM-1, DON and DOM-1 glucuronides were analyzed by reverse-phase HPLC in urine and feces after the single oral dose of DON (8 mg/kg). Selenium-supplemented (5 ppm) diet increased by 2-3 times formation and elimination of DON and DOM-1 glucuronides in urine. Selenium-deficient diet decreased formation of DOM-1, but increased significantly total excretion of DON and DON glucuronides. The activity of GT1 and GT2 forms of UDP-glucuronosyltransferase, an enzyme principally responsible for glucuronidation, was two times higher in the liver of rats fed both selenium-supplemented and selenium-deficient diets.

Administration, Oral↗
PubMedDate not supplied

Mycotoxins.

Explore the source record for details and available documents.

Aflatoxins↗
PubMed1996

Leukoencephalomalacia and hemorrhage in the brain of rabbits gavaged with mycotoxin fumonisin B1.

Two of five pregnant rabbits gavaged with purified fumonisin B1 at 1.75 mg/kg/day died, one after 9 and one after 13 doses. Microscopic examination revealed focal small hemorrhages in cerebral white matter in both animals, with malacia and hemorrhage also present in the hippocampus of one. The lesions were bilateral. Both animals also had marked degeneration of renal tubule epithelium and of hepatocytes. Apoptosis was the dominant degenerative change in kidney and liver. Fumonisin is known to cause leukoencephalomalacia and hemorrhage in equines, but CNS changes associated with exposure to fumonisins apparently have not been reported in other species. This preliminary observation in rabbits is reported to alert other investigators of a potential model of the disease in equines, as well as for investigation of potential mechanisms of toxicity to the CNS.

Animals↗
PubMed1981

Mycotoxins in cereal grain. Part III. Production of ochratoxin A in different varieties of wheat, rye and barley.

Kernels of several varieties of wheat, rye and barley were found to have different resistance to fungi attack and ochratoxin A production, particularly in first step of fungus development on kernels. Zinc was stated to be a limiting factor of ochratoxin production. viable sound kernels were very resistant against fungi. Dead (e.g. autoclaved) kernels were attacked by fungus very quickly. Varieties with stronger resistance to fungi invasion during storage were selected.

Aspergillus↗
PubMed1987

Mycotoxins in cereal grain. Part 12. Contamination with ochratoxin A and penicillic acid as indicator of improper storage of cereal grain.

Formation of ochratoxin A and penicillic acid in wheat kernels at 6 moisture levels: 15, 18, 21, 24, 27 and 30% at 15 degrees C has been examined during 4 months of storage. The minimum time for formation of significant amount (0.5-1 mg/kg) of ochratoxin A and penicillic acid (6-8 mg/kg) in stored grain has been found for the various water contents as follows: 18%-16 weeks, 21%-6 weeks, 24% and more - 2 weeks. At 15% of moisture content formation of ochratoxin A and penicillic acid was not observed until 4 months of storage.

Caproates↗
PubMed1987

[Carcinogenic and genotoxic effects of mycotoxins].

Aflatoxin B1 is the most potent hepatocarcinogen among the naturally occurring compounds. It's carcinogenic effect was confirmed by longterm-studies in several animal species. There exists detailed knowledge on the molecular mechanism of the carcinogenic effect caused by aflatoxin B1. At present there does not exist a reliable evidence that human primary hepatocellular carcinoma is caused by aflatoxins. Sterigmatocystin is a hepatocarcinogen too. The genotoxicity of sterigmatocystin likewise as of aflatoxin B1 was detected by short-term-tests with microbial systems and mammalian cells in vitro. It is disputable whether ochratoxin A, citrinin and T-2 toxin are carcinogenic or not. Diacetoxyscirpenol, zearalenone and patulin are estimated as not carcinogenic after longterm-studies with oral toxin administration. Patulin and penicillic acid are genotoxic in microbial systems respectively in mammalian cells in vitro. Luteoskyrin is carcinogenic, but there was not detected any genotoxicity.

Animals↗
PubMed1992

Mycotoxic flora and mycotoxins in smoke-dried fish from Sierra Leone.

Examination of 20 samples of smoke-dried fish of the Ethmolosa sp. commonly called "Bonga", from homes and markets in Njala (Sierra Leone) revealed the presence of 4 Aspergilli species: A. flavus Links ex Fries, A. ochraceus Wilhelm, A. tamarii Kita and A. niger van Tieghem. Fresh or properly preserved smoke-dried fish showed no signs of fungal contamination. Mouldy fish extracts contained varying amounts of aflatoxins B1, G1, G2 and ochratoxin A. Isolates of A. flavus grown on yeast extract sucrose (YES) medium, produced considerable amounts of aflatoxin B1 and G1 and trace amounts of G2. On YES medium A. ochraceus produced large amounts of ochratoxin A but no penicillic acid.

Aflatoxins↗
PubMed1994

Mould contamination and the influence of water activity and temperature on mycotoxin production by two aspergilli in melon seed.

Both the moisture levels and the incidence of mould contamination recorded for shelled water melon seed samples (22) obtained from 9 markets were generally higher as those recorded for the unshelled seed samples. 16 fungi, mostly toxigenic, were isolated from the surface-disinfected mouldy seeds. Of these isolates, 7, 3 and 2 species belonged to Aspergillus, Penicillum and Fusarium genera, respectively, while Botryodiplodia, Rhizopus, Sclerotium and Syncephalastrum had one representative each. Production of aflatoxins (B1, B2) by 5 toxigenic strains of Aspergillus flavus and of ochratoxin A by 4 toxigenic strains of A. ochraceus in melon seed at varying water activity (aw) and temperature levels were investigated. Of the aw levels (0.65, 0.70, 0.80, 0.90 and 0.98) provided, toxins were detected only at and above 0.80 with the peak production recorded at either 0.90 or 0.98 aw level. Whereas aflatoxins were produced and detected under all the test temperatures (15, 20, 25, 30, 35, and 40 degrees C), the elaboration of ochratoxin A was detected only as from 25 to 40 degrees C. Optimum temperature for toxin production by all the strains of the two fungi used was 30 degrees C.

Aflatoxin B1↗