The Mycotoxins
Las Micotoxinas.
***********************************
****** DATA-MÉDICOS *********
*********************************
LAS MICOTOXINAS / THE MYCOTOXINS
**************************************
***** DERMAGIC-EXPRESS No 3 ******
****** 18 OCTUBRE DE 1.998 *******
************************************
EDITORIAL ESPAÑOL
===============
Hola amigos DERMAGICOS, a propósito del simposio VIRTUAL sobre
MICOTOXINAS, que la Dra. Gioconda San Blas invita entre el 19 y 23 de
Octubre (esta semana) ENCONTRÉ, en las BASES DE DATOS algunas
referencias interesantes al respecto, de modo que el tema sobre el
FINASTERIDE irá después.
La idea de esta LISTA BIBLIOGRÁFICA, es cubrir en lo posible TODOS los
capítulos ligados a la dermatología, y la MICOLOGÍA forma parte
integral de ella, es por ello que la edición de hoy va dedicada a este
tema, sobre LAS MICOTOXINAS. Espero que les guste.
====================================================================
DERMAGIC/EXPRESS(3)
=====================================================================
LAS MICOTOXINAS /
THE MYCOTOXINS
=====================================================================
REFERENCIA: 1: Ochratoxin A
REFERENCIA: 2: T-2 toxin
REFERENCIA: 3: aflatoxin B1, zearalenone and deoxynivalenol
REFERENCIA: 4: Stachybotrys chartarum
REFERENCIA: 5: ochratoxin A
REFERENCIA: 6: Fumonisin B1 (FB1)
REFERENCIA: 7: aflatoxin B1, aflatoxin B1-8,9-epoxide
REFERENCIA: 8: micotoxinas y quesos
REFERENCIA: 9: rubratoxin-B biosynthesis
REFERENCIA: 10: Ochratoxin A y nefropatia
REFERENCIA: 11: fumonisin, Fusarium moniliforme
REFERENCIA: 12: trichothecene toxin T-2
REFERENCIA: 13: Ochratoxin A y nefropatia
REFERENCIA: 14: nivalenol.
=====================================================================
1.) Ochratoxin A-induced stimulation of extracellular signal-regulated
kinases 1/2 is associated with Madin-Darby canine kidney-C7 cell
dedifferentiation.
=====================================================================
AU: Schramek-H; Wilflingseder-D; Pollack-V; Freudinger-R;
Mildenberger-S; Gekle-M
AD: Department of Physiology, University of Innsbruck, Innsbruck,
Austria.
SO: J-Pharmacol-Exp-Ther. 1997 Dec; 283(3): 1460-8
ISSN: 0022-3565
PY: 1997
LA: ENGLISH
CP: UNITED-STATES
AB: The kidneys represent one of the main targets of ochratoxin A (OTA),
a secondary fungal metabolite that is produced by certain species of
Aspergillus and Penicillium. OTA has the ability to disturb
Madin-Darby canine kidney (MDCK) cell pH homeostasis, leading to
intracellular alkalinization and morphological alterations resembling
those that occur when MDCK cells are exposed to transient alkaline
stress. Because alkali-induced epithelial dedifferentiation of MDCK-C7
cells is associated with an increase in the activity of extracellular
signal-regulated kinases (ERK), we performed experiments that
investigated a possible role for ERK1 and ERK2 as intracellular
signaling molecules mediating some of the mycotoxin's effects on renal
epithelia. We studied the effects of OTA on ERK1/2 phosphorylation and
activation, as well as on cell morphology by using cloned MDCK-C7 and
MDCK-C11 cells. In MDCK-C7 cells, but not in MDCK-C11 cells, OTA led
to a time-dependent and concentration-dependent increase in ERK1/2
phosphorylation. OTA-induced ERK1/2 phosphorylation in MDCK-C7 cells
occurred at concentrations of 500 nM, started after 2 hr and was
maximal after 8 hr. Furthermore, after 8 hr of incubation, 500 nM and
1 &mgr;M OTA significantly increased ERK1/2 activity in MDCK-C7 but
not in MDCK-C11 cells. This OTA-stimulated ERK1/2 phosphorylation and
ERK1/2 activation in MDCK-C7 cells was partially inhibited by the
synthetic mitogen-activated protein kinase kinase (MKK or MEK)
inhibitor PD098059. Transepithelial resistance and lactate
dehydrogenase release remained unaltered after incubation in the
presence of 1 microM OTA for 8 hr or of 100 nM OTA for 24 hr, so it is
unlikely that these OTA effects on ERK1/2 are due to secondary toxic
effects of the mycotoxin. Interestingly, OTA-induced long-term
activation of ERK1/2 in MDCK-C7 cells was associated with epithelial
dedifferentiation, as assessed by analysis of vectorial solute and
water transport as well as cell morphology. In contrast, MDCK-C11
cells, which do not show significant increases in ERK1/2
phosphorylation and ERK1/2 activity in response to OTA, retained their
epithelial phenotype under identical experimental conditions. Taken
together, our data demonstrate an epithelial dedifferentiation of
MDCK-C7 cells, but not of MDCK-C11 cells, after long-term incubation
in the presence of OTA, a result associated with the ability of this
mycotoxin to stimulate ERK1/2 in MDCK-C7 cells but not in MDCK-C11
cells. We conclude that OTA-induced activation of ERK1/2 could be an
important intracellular signaling pathway that mediates some of the
mycotoxin's effects on renal epithelia.
=====================================================================
2.) TI: Apoptotic cellular damage in mice after T-2 toxin-induced acute
toxicosis.
=====================================================================
AU: Ihara-T; Sugamata-M; Sekijima-M; Okumura-H; Yoshino-N; Ueno-Y
AD: Department of Pathology, Institute of Tochigi Clinical Pathology,
Tochigi, Japan.
SO: Nat-Toxins. 1997; 5(4): 141-5
ISSN: 1056-9014
PY: 1997
LA: ENGLISH
CP: UNITED-STATES
AB: By histopathologic, electron microscopic, and immunochemical
observation, the mechanism of cellular death was investigated in
thymus, spleen, and liver of mice given intraperitoneally sublethal
doses of T-2 toxin, a trichothecene mycotoxin. In the thymus and
spleen of mice given 5.0 mg/kg body weight of T-2 toxin and killed 12
hours later, a massive cellular destruction characterized by chromatin
condensation was evident, and electron microscopy analysis revealed
the presence of apoptotic bodies. In the liver of mice given 2.5 mg/kg
of T-2 toxin and killed 2 hours later, the induction of apoptotic
cellular lesions was observed by electron microscopy, and Kupffer
cells phagocytosed the apoptotic bodies. Such lesions were not
observed in the mice killed 12 hours after receiving the toxin. In
situ nick translation analysis (Tunel method) revealed DNA
fragmentation in thymus, spleen, and liver shortly after
administration of T-2 toxin. As previously observed in vitro, these
findings indicated that T-2 toxin is a potent inducer of apoptotic
cell death in thymus, spleen, and liver in vivo; especially in liver,
apoptosis is induced rapidly as compared with the other tissues
observed, and Kupffer cells play an important role for clearance of
apoptosis.
=====================================================================
3.) TI: Mycoflora and incidence of aflatoxin B1, zearalenone and
deoxynivalenol in poultry feeds in Argentina.
=====================================================================
AU: Dalcero-A; Magnoli-C; Chiacchiera-S; Palacios-G; Reynoso-M
AD: Dpto. de Microbiologia e Inmunologia, Facultad de Ciencias, Exactas
Fisico-Quimicas y Naturales, Universidad Nacional de Rio Cuarto.
SO: Mycopathologia. 1997; 137(3): 179-84
ISSN: 0301-486X
PY: 1997
LA: ENGLISH
CP: NETHERLANDS
AB: In Argentina, there is rather little information about the natural
occurrence of mycotoxins in feedstuffs. The aim of this work was to
determine the fungal flora and natural incidence of aflatoxin B1
(AFB1), zearalenone (ZEA) and deoxynivalenol (DON) in poultry feeds
from 5 factories of Rio Cuarto, Cordoba. Three hundred samples were
taken from May 1995 to May 1996. Fungal counts of poultry feeds ranged
10(4) to 10(6) CFU g-1. The lowest counts were obtained on the first
months from the sampling (May to September 1995) with mean values
significantly different from those found at the last of the sampling
(October 1995 to April 1996). The most prevalent species isolated of
poultry feed samples belonged to the genera Penicillium that was
present in 98% of the samples, Fusarium (87%) and Aspergillus (52%).
Fusarium species isolated were: F moniliforme in 73% of the samples, F
subglutinans (35%), F graminearum (20%) and within Aspergillus
species: A. parasiticus (33%) and A. flavus (8%) were identified. In
poultry feeds aflatoxin B1 (AFB1) was the most significant mycotoxin
with levels ranging from 17 to 197 ng/g. For deoxynivalenol (DON) the
levels ranged from 240 to 410 ng/g. Only three out of 300 samples were
contaminated with zearalenone (ZEA) in concentrations of 30, 120 and
280 ng/g. These are preliminary data on this subject in our region.
=====================================================================
4.) TI: [Mass development of Stachybotrys chartarum on compostable plant
pots made from recycled paper]
=====================================================================
TO: Massenentwicklung von Stachybotrys chartarum auf kompostierbaren
Pflanztopfen aus Altpapier.
AU: Dill-I; Trautmann-C; Szewzyk-R
AD: Fachgebiet Okologie der Mikroorganismen, Technische Universitat
Berlin, BR Deutschland.
SO: Mycoses. 1997; 40 Suppl 1: 110-4
ISSN: 0933-7407
PY: 1997
LA: GERMAN; NON-ENGLISH
CP: GERMANY
AB: After handling plants grown in decomposable pots made of recycling
paper, three women working in a big horticulture developed very
painful inflammated efflorescences at the finger-tips, followed by
scaling off the skin. The pots appeared to be very mouldy. Black
masses of conidia of Stachybotrys chartarum and perithecia of
Chaetomium globosum were identified on almost every pot. Apart from
various other fungal genera, Trichoderma und Acremonium were
frequently detected. Considering the observed symptoms, special
attention was payed to the mycotoxin producing species St. chartarum.
To evaluate the inhalative spore load, air sampling was performed. The
detection of St. chartarum in the air was only possible with the spore
trap (sampling of particles) but not with the Andersen sampler
(detection of colony forming units). Without moving the pots,
measurements yielded values of 30-100 St. chartarum conidia per m3 of
air. The concentration of air-borne conidia increased drastically by
handling the pots, thus attaining up to 7,500 conidia per m3 of air
for St. chartarum only. The occurrence of St. chartarum in such
amounts is alarming because of possible toxin production. In addition,
the allergenic stress by fungal spores has to be emphasized. The
results are discussed with regard to general medical-mycological
aspects related to the degradation of environmentally-friendly
decomposable materials.
=====================================================================
5.) TI: Effects of ochratoxin A on DNA repair in cultures of rat
hepatocytes and porcine urinary bladder epithelial cells.
=====================================================================
AU: Dorrenhaus-A; Follmann-W
AD: Institut fur Arbeitsphysiologie an der Universitat Dortmund,
Germany.
SO: Arch-Toxicol. 1997; 71(11): 709-13
ISSN: 0340-5761
PY: 1997
LA: ENGLISH
CP: GERMANY
AB: In cultured rat hepatocytes the mycotoxin ochratoxin A (OTA) induced
unscheduled DNA synthesis (UDS) only in a narrow concentration range.
Using a culture medium supplemented with 1% fetal calf serum, at 750
nM OTA a weak induction and at 1 microM OTA a marked induction of DNA
repair was observed (15 +/- 11 and 38 +/- 24% cells in repair,
respectively). Concentrations > 1 microM OTA were cytotoxic, and <750
nM no induction occurred. In cultures of cells from the urinary
bladder (porcine urinary bladder epithelial cells; PUBEC), a target
organ of the mycotoxin, OTA induced UDS in a concentration-dependent
manner. To inhibit the proliferation of the cultured epithelial cells,
which would counteract the detection of DNA repair, epidermal growth
factor was omitted and an arginine-deficient medium (ADM) was used.
Under these serum-free culture conditions the amount of cells
undergoing DNA repair in PUBEC control cultures was approximately 7
+/- 4%, a value also comparable to those of control cultures of rat
hepatocytes. At concentrations between 250 nM and 1 microM OTA a
concentration-dependent increase of cells in repair was observed.
Above 1 microM OTA was cytotoxic. At this concentration a maximum of
approximately 61 +/- 9% of the cells undergo DNA repair. This amount
is comparable to control cultures incubated with 5 or 10 mM
ethylmethane-sulphonate (EMS) (49 +/- 9 and 69 +/- 10% cells in
repair, respectively), used as a positive control. These results show
that in cultured rat hepatocytes induction of UDS is relatively weak
whereas in urothelial cells this effect was significant. Whether this
effect is due to OTA metabolites formed locally in the urothelium
cannot be excluded since PUBEC have been shown to be able to
metabolize xenobiotics independently from the liver.
=====================================================================
6.) TI: Mycotoxin-induced elevation of free sphingoid bases in
precision-cut rat liver slices: specificity of the response and
structure-activity relationships.
=====================================================================
AU: Norred-WP; Plattner-RD; Dombrink-Kurtzman-MA; Meredith-FI; Riley-RT
AD: Richard B. Russell Agricultural Research Center, ARS/USDA, Athens,
Georgia 30604-5677, USA.
SO: Toxicol-Appl-Pharmacol. 1997 Nov; 147(1): 63-70
ISSN: 0041-008X
PY: 1997
LA: ENGLISH
CP: UNITED-STATES
AB: Fumonisin B1 (FB1) is the predominant member of a family of toxic
metabolites produced by several species of Fusarium and is commonly
found on corn. FB1 is a potent competitive inhibitor of ceramide
synthase, which catalyzes the conversion of sphinganine and
sphingosine to ceramide. The resultant accumulation of free sphingoid
bases and the disruption of sphingolipid metabolism is believed to be
the mechanism of toxicity of the fumonisins. The objectives of this
study were to determine the relative potency of analogs of FB1 to
inhibit ceramide synthase and to determine whether the inhibition is
specific to mycotoxins with fumonisin-like structures. Fumonisins B1,
B2, B3, B4, C4, and TA toxin (a structurally similar mycotoxin
produced by the tomato pathogen, Alternaria alternata f. sp.
lycopersici) were approximately equipotent inhibitors. Hydrolyzed
fumonisins B1, B2, and B3, which lack the tricarballylic side chains,
were only 30-40% as potent as the parent toxins. N-acetylated FB1
(FA1) did not block ceramide synthase, suggesting that FA1 is
nontoxic. Inhibition of ceramide synthase by fumonisin analogs did not
appear to be related to the lipophilicity of the compounds, as
determined by computer estimation of log P values. The ability of
relatively high (10 and 100 &mgr;m) doses of other mycotoxins that
bear no structural similarity to fumonisins, including aflatoxin B1,
cyclopiazonic acid, beauvericin, T-2 toxin, sterigmatocystin,
luteoskyrin, verrucarin A, scirpentriol, and zearalenone, to block
ceramide synthase was also determined. All of the toxins tested were
negative in the bioassay with the exception of fumonisins, indicating
that disruption of sphingolipid metabolism is a specific cytotoxic
response. Copyright 1997 Academic Press.
MESH: Acetylation-; Alternaria-; Liver-metabolism; Rats-;
Rats,-Sprague-Dawley; Sphingosine-analogs-and-derivatives;
Sphingosine-analysis; Structure-Activity-Relationship;
Tomatoes-metabolism; Tomatoes-microbiology
=====================================================================
7.) TI: Metabolic activation of aflatoxin B1 to aflatoxin B1-8,9-epoxide
in woodchucks undergoing chronic active hepatitis.
=====================================================================
AU: Gemechu-Hatewu-M; Platt-KL; Oesch-F; Hacker-HJ; Bannasch-P;
Steinberg-P
AD: Institute of Toxicology, University of Mainz, Germany.
SO: Int-J-Cancer. 1997 Nov 14; 73(4): 587-91
ISSN: 0020-7136
PY: 1997
LA: ENGLISH
CP: UNITED-STATES
AB: Chronic hepatitis B virus infection as well as consumption of food
contaminated with the mycotoxin aflatoxin B1 are considered to be 2
major risk factors for the development of primary liver cancer in
humans. Furthermore, epidemiological surveys indicate that hepatitis B
virus and aflatoxin B1 might act synergistically to induce primary
liver cancer. In the present study, we have tested the hypothesis that
the metabolic activation of aflatoxin B1 to aflatoxin B1-8,9-epoxide,
the ultimate mutagenic and carcinogenic mycotoxin metabolite, is
enhanced in an experimental model of chronic hepatitis using
woodchucks, chronically infected with the woodchuck hepatitis virus.
Woodchuck liver microsomes were incubated with radiolabeled aflatoxin
B1, the resulting aflatoxin B1-8,9-epoxide was trapped as a
glutathione conjugate and its formation rate was determined by a
reversed-phase HPLC analysis. In woodchuck hepatitis virus-positive
woodchucks, activation of aflatoxin B1 to aflatoxin B1-8,9-epoxide was
reduced when compared to woodchuck hepatitis virus-free animals, and
the extent of the reduction was dependent on the severity of the
hepatitis. Hence, at least in woodchucks, a chronic hepadnaviral
infection does not lead to an enhanced activation of aflatoxin B1.
======================================================================
8.) Development of a semisynthetic cheese medium for fungi using
chemometric methods.
======================================================================
Hansen BV; Nielsen PV
Department of Biotechnology, Technical University of Denmark, Lyngby,
Denmark.J Dairy Sci (UNITED STATES) Jul 1997 80 (7) p1237-45 ISSN: 0022-0302
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9711
Subfile: INDEX MEDICUS
The growth, color formation, and mycotoxin production of six
cheese-related fungi were studied on nine types of natural cheeses and 24 semisynthetic
cheese media and compared using principal component analysis. The semisynthetic cheese
media contained various amounts of Ca, K, Mg, Na, P, Fe, Cu, Zn, lactate,
lactose, and casein. A robust well-defined and easily prepared semisynthetic cheese
medium was developed for Penicillium commune, the most frequently occurring
contaminant on semihard cheese. Growth experiments on the medium were repeatable and
reproducible. The medium was also suitable for Penicillium camemberti.
The medium had
the following composition: 100 g of casein, 8.3 g of 90% lactate, 7.9 g of
lactose, 7.3 g of CaCl2.2H2O, 2.6 g of MgSO4.7H2O, 26.0 g of NaCl, 20 g of agar, 0.025
g of FeSO4.7H2O, 0.004 g of CuSO4.5H2O, and water to a total weight of 1 kg.
The semisynthetic cheese medium was less suitable for Penicillium
roqueforti, Penicillium discolor, Penicillium verrucosum, and Aspergillus versicolor. However,
another semisynthetic cheese medium could be recommended for P. roqueforti and
P. discolor. That medium had higher contents of P (5000 ppm, wt/wt), K (5000 ppm),
and Zn (50 ppm) and lower contents of Na (2700 ppm), Fe (1 ppm), Cu (0.1 ppm), and
casein (1%).
=====================================================================
9.) Regulation of rubratoxin-B biosynthesis: assessment of role of
gamma-irradiation,
pH and carbohydrates.
=====================================================================
Aziz NH; Abdel-Aal SS
National Centre for Radiation Research and Technology, Cairo, Egypt.
Microbios (ENGLAND) 1997 89 (358) p47-54 ISSN: 0026-2633
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9710
Subfile: INDEX MEDICUS
The maximum rubratoxin-B yield was obtained at pH 5.5,, and by
increasing the initial pH to near neutrality the yield decreased for both yeast extract
sucrose (YES) and Sabouraud dextrose yeast extract (SDYE) media, but the
concentration of mycotoxin was higher in YES medium. The rubratoxin-B yield from
Penicillium purpurogenium decreased with increasing gamma-irradiation, and at 1.0
kGy no mycotoxin was detected at any pH values. In both the unirradiated and
irradiated P. purpurogeniium cultures, as the rubratoxin-B synthesis increased from 46
to 72 h, the
lipid content decreased. The concentration (mmoles/g dry wt mycelium) of
puridine nucleotides in the mycelium of P. purpurogenium during growth in YES and
SDYE media may be a factor in rubratoxin-B synthesis. An elevated NADPH/ NADP ratio
favours fatty acid synthesis whereas a depressed NADPH/NADP ratio favours
mycotoxin formation.
The gamma-irradiation played a role in the regulation of rubratoxin-B
biosynthesis.
======================================================================
10.) Molecular and epidemiological approaches to the etiology of urinary
tract tumors in an area with Balkan endemic nephropathy.
======================================================================
Nikolov IG; Petkova-Bocharova D; Castegnaro M; Pfohl-Leskowicz A; Gill
C; Day N; Chernozemsky IN
National Oncological Centre, Sofia, Bulgaria.
J Environ Pathol Toxicol Oncol (UNITED STATES) 1996 15 (2-4) p201-7
ISSN: 0731-8898
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9710
Subfile: INDEX MEDICUS
Recently, we completed a second biostatistical study of urinary tract
tumors (UTT) in areas with Balkan endemic nephropathy (BEN) in the Vratza district,
Bulgaria, during the period 1975 to 1991. We confirmed the positive correlation
between the incidence of urinary tract tumors (UTT) and BEN demonstrated in our
first population-based case control 1977 study. A UTT incidence of 98.9 per 100,000 men
and 74.7 per 100,000 women was found in villages most affected by BEN when compared
with 11.0 and 6.7 for men and women, respectively, in nonendemic villages. The
relative risk (RR) of UTT in BEN villages showed tumors of kidney pelvis and ureters-29 in
men and 35 in
women and urinary bladder tumors-4 in men and 11 in women. The
percentage of food and blood samples containing nephrotoxic and carcinogenic mycotoxin
Ochratoxin A (OTA) correlated with the origin of the samples. The most contaminated
samples were found in BEN villages and households, and the urinary excretion of OTA
was higher in
the group of BEN/UTT patients. The UTT DNA's were studied by the
32P-postlabeling method for the presence of OTA-DNA adducts. Some OTA-DNA adducts
characteristic for endemic UTT and absent in control nonendemic UTT and nontumorous tissues
were described for the first time.
======================================================================
11.) Dietary Fusarium moniliforme culture material induces in vitro
tumor necrosis
factor-alpha like activity in the sera of swine.
=======================================================================
Guzman RE; Bailey K; Casteel SW; Turk J; Rottinghaus G
Veterinary Medical Diagnostic Laboratory, College of Veterinary
Medicine, University of Missouri-Columbia, USA.
Immunopharmacol Immunotoxicol (UNITED STATES) May 1997 19 (2) p279-89
ISSN: 0892-3973
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9710
Subfile: INDEX MEDICUS
Sera obtained from a group of pigs (n = 5) fed a diet amended with
fumonisin
containing Fusarium moniliforme culture material was used to determine
the levels of Tumor Necrosis Factor-Alpha (TNF) activity by a functional bioassay
utilizing the TNF sensitive WEHI 140 mouse fibrosarcoma cell line. Two pigs developed
signs consistent with pulmonary edema which was confirmed by pathologic examination in
only one pig. Significant, time dependent increases in TNF-like activity were observed
in all pigs during the five days of the trial. Another group of pigs (n = 5) was
given a defined daily dose of the same culture material by gastric intubation. Two pigs
developed fulminant pulmonary edema and sharp increases in TNF activity were
observed during the 3 days of the trial in all pigs. In both cases the activity was not
abrogated by addition of a neutralizing anti-human TNF monoclonal antibody suggesting
that other factors may have been responsible for these effects, possibly the
increased levels of sphingoid bases in the serum. Since the pig has become an important
model in the study of TNF mediated endotoxic shock, these studies illustrate the
relevance of certifying the absence of this important mycotoxin from corn based
animal diets, specially if functional assays are used to monitor the activity of TNF
in serum.
======================================================================
12.) [Studies on relationship between toxicity of trichothecene toxin
T-2 and its
structure]
======================================================================
Peng S; Dong J; Yang J
Institute of Toxicology and Pharmacology Academy of Military Medical
Sciences, Beijing.
Chung Hua Yu Fang I Hsueh Tsa Chih (CHINA) May 1996 30 (3) p141-3 ISSN:
0253-9624
Language: CHINESE Summary Language: ENGLISH
Document Type:
JOURNAL ARTICLE English
Abstract
Journal Announcement: 9709
Subfile: INDEX MEDICUS
Toxic action of mycotoxin T-2 and its metabolite T-2 tetraol and deepoxy
T-2; tetraol was studied by cytotoxicity and animal toxicity tests to explore
the relationship between toxin T-2 and its structure. Restults showed that
proliferation
of LLC-PK1 cells and synthesis of DNA could be inhibited by both toxin
T-2 and T-2 tetraol. Toxicity of toxin T-2 was 100 times greater than that of T-2
tetraol. There was no obvious toxicity to the proliferation of LLC-PK1 cells and
synthesis of DNA in a dose of 10 mg/L deepoxy T-2 tetraol. But, toxin T-2 caused
obvious damage in heart muscle and articular cartilage of chicken embryos, and T-2
tetraol and deepoxy T-2 tetraol in heart muscle, but not in articular cartilage. T-2
tetraol produced by hydrolysis of toxin T-2 had toxicity to certain extent, but
its strength
was significantly less than that of the latter. It suggests that the
epoxide group in toxin T-2 played a determinant role for its toxicity. If epoxy cycle
of the basic nucleus of the molecule is open, its toxicity will change significantly.
======================================================================
13.) Ochratoxin A in human sera in the area with endemic nephropathy in
Croatia.
======================================================================
Radic B; Fuchs R; Peraica M; Lucic A
Department of Toxicology, Institute for Medical Research and
Occupational Health, Zagreb, Croatia.
Toxicol Lett (NETHERLANDS) Apr 28 1997 91 (2) p105-9 ISSN: 0378-4274
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9709
Subfile: INDEX MEDICUS
Ochratoxin A (OA) is nephrotoxic fungal metabolite (mycotoxin) occurring
in foodstuffs. The compound is causally associated with mycotoxin porcine
nephropathy, a disease comparable with a human kidney disease called endemic
nephropathy (EN). In this paper we presented results obtained over a 10-year period in the
hyperendemic village Kaniza, and in control villages where no clinical cases of
nephropathy had been found. In the hyperendemic village Kaniza and non-endemic villages
the incidence of OA in human blood was up to 4.5% (range 2-50 ng/ml) and up
to 2.4% (range 2-10 ng/ml), respectively. Almost all samples of food and feed,
collected randomly in the hyperendemic village were found to contain OA.
Considering marked exposure to OA in Kaniza, it was assumed that incidence of EN in this
population could be related to OA contamination of food and feed.
======================================================================
14 Experimental IgA nephropathy induced by a low-dose environmental
mycotoxin, nivalenol.
======================================================================
Hinoshita F; Suzuki Y; Yokoyama K; Hara S; Yamada A; Ogura Y; Hashimoto
H; Tomura S; Marumo F; Ueno Y
Kidney Center, Toranomon Hospital, Tokyo, Japan.
Nephron (SWITZERLAND) 1997 75 (4) p469-78 ISSN: 0028-2766
Language: ENGLISH
Document Type: JOURNAL ARTICLE
Journal Announcement: 9708
Subfile: INDEX MEDICUS
Based on the hypothesis that IgA nephropathy (IgAN) is triggered by some
exogenous antigen(s) which induces dysregulation of the mucosal immune system, we
developed an experimental model of orally induced IgAN by an environmental mycotoxin,
nivalenol (NIV), which often contaminates agricultural products in Southeast Asia
and Japan.
In the present study, low doses of oral NIV reproducibly induced
significant IgA deposits in the glomerular mesangium and elevated serum IgA levels in
mice irrespective of the strain; the degree of immunopathological changes
analogous to human IgAN was associated with the dose and duration of NIV treatment.
Furthermore, a competitive enzyme-linked immunosorbent assay with an NIV
analogue-protein conjugate disclosed that the IgA antibody in the sera from the NIV model
mice had a higher affinity to the mycotoxin. Conclusively, these findings suggest
that NIV induces some pathological changes in mice which resemble those in human
IgAN, and that this mycotoxin is associated with pathogenesis in some types of glomerulonephritis.
======================================================================
DATA-MÉDICOS/DERMAGIC-EXPRESS No (3) 18/10/98 DR. JOSÉ LAPENTA R.
DERMATÓLOGO
======================================================================
|
