The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform

Moreau P.-a. Van Vooren N. - One of the best experts on this subject based on the ideXlab platform.

Bela Toth - One of the best experts on this subject based on the ideXlab platform.

  • Cancer Induction in Mice Methylformylhydrazone of With Acetaldehyde the False Morel Mushroom 1,2,3,4
    2016
    Co-Authors: Bela Toth, James W. Smith, Kashinath D. Patil
    Abstract:

    which occurs up to 0.3 % in one of the edible false morel mush-rooms, Gyromitra escu/enta, was administered to noninbred Swiss mice in propylene glycol in 52 weekly intragastric instilla-tions as 100 J.lg/g body weight. The treatment induced tumors of the lungs, preputial glands, forestomach, and clitoral glands. The tumor incidences in these four tissues in treated females were 70, 0, 16, and 12%, respectively, whereas in the treated males they were 40, 90, 0, and 0%. The corresponding tumor incidences in the solvent control females were 26, 0, 0, and 0%, whereas in the solvent control males they were 22, 0, 0, and 0%, respectively. Histopathologically, the neoplasms were classified as adenomas and adenocarcinomas of the lungs; squamous cell papillomas and carcinomas, adenocarcinomas, undifferentiated carcinomas, an-giosarcomas, and fibrosarcomas of the preputial glands; squamous cell papillomas and carcinomas of the forestomach; and squa

  • Gyromitra esculenta mushroom: a comparative assessment of its carcinogenic potency.
    In vivo (Athens Greece), 1994
    Co-Authors: Bela Toth, Peter M. Gannett
    Abstract:

    A comparative assessment is performed on one of the false morel mushrooms, Gyromitra esculenta, including the amounts of some hydrazines present in this fungus, the cancer-inducing doses of these chemicals or the mushroom used in animal experiments, the total amounts of the hydrazines or mushroom needed to induce neoplasms in mice and the estimated total amounts of hydrazines or mushroom needed to induce cancer in humans. When one compares the estimated amounts of hydrazines required to induce cancer with the amount of raw Gyromitra esculenta needed to yield a similar effect, it becomes clear that to date 37 percent of the carcinogenic ingredients of this fungus have been identified.

  • Cancer Induction in Mice by Feeding the Raw False Morel Mushroom Gyromitra esculenta
    Cancer research, 1992
    Co-Authors: Bela Toth, Heikki Pyysalo, Kashinath Patil, Carol Stessman, Peter M. Gannett
    Abstract:

    Abstract One of the false morel mushrooms, Gyromitra esculenta, was administered p.o. to Swiss mice that were 6 weeks old at the beginning of the experiment. The mushrooms were fed to the mice for 3 days and were followed by a semisynthetic diet for 4 days each week for life. The treatment induced tumors in the lungs, nasal cavity, blood vessels, forestomach, glandular stomach, cecum, and liver in the following incidences: 80, 10, 50, 16, 4, 28, and 6% in females, and 70, 12, 32, 18, 20, 22, and 12% in males. In the untreated controls, the corresponding tumor incidences were 28, 0, 14, 0, 0, 8, and 0% in females and 38, 0, 6, 0, 0, 8, and 2% in males. The light microscopic examination revealed the typical appearance of adenomas and adenocarcinomas of lungs, adenomas and adenocarcinomas of nasal cavities, hemangiomas and hemangiosarcomas of blood vessels, squamous cell papillomas and carcinomas of the forestomach, adenomas and adenocarcinomas of the glandular stomach, polypoid adenomas and adenocarcinomas of the cecum, and hepatomas. The work demonstrates the carcinogenic action of the raw G. esculenta mushroom.

  • Poisoning by Gyromitra esculenta--a review.
    Journal of Applied Toxicology, 1991
    Co-Authors: Didier Michelot, Bela Toth
    Abstract:

    Gyromitra esculenta (Pers.: Fr.) Fr. and a few other mushrooms have caused severe poisonings and even deaths in humans. Clinical data are characterized primarily by vomiting and diarrhea, followed by jaundice, convulsions and coma. Gastrointestinal disorders distinguish this poisoning. Frequent consumption can cause hepatitis and neurological diseases. The species of concern are mainly G. esculenta and G. gigas (Kromb.) Cooke (non Phill.). Nevertheless, recent advances in chromatography, biochemistry and toxicology have established that other Ascomycetes species also may prove toxic. Gyromitrin (acetaldehyde methylformylhydrazone, G) and its homologues are toxic compounds that convert in vivo into N-methyl-N-formylhydrazine (MFH), and then into N-methylhydrazine (MH). The toxicity of these chemicals, which are chiefly hepatotoxic and even carcinogenic, has been established through in vivo and in vitro experiments using animals, cell cultures and biochemical systems. When we consider the chemical nature and the reactivity of these natural compounds, we suggest that chemical and biochemical mechanisms may explain their intrinsic biological activity.

  • Chemical oxidation and metabolism of N-methyl-N-formylhydrazine. Evidence for diazenium and radical intermediates
    Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 1991
    Co-Authors: Peter M. Gannett, C. Garrett, Terence Lawson, Bela Toth
    Abstract:

    Abstract N -Methyl N -formylhydrazine ( 1 ), a component of the mushroom Gyromitra esculenta , is a carcinogen. Its mode of action, however, is poorly understood. To determine the intermediates that may form during the metabolism of 1 , we examined its oxidative chemistry, identified the products and inferred the intermediates on the basis of these products. The incubation of 1 with rat liver microsomes was also studied and the metabolites determined and quantified. Both the chemical and the microsome-mediated oxidation of 1 yielded formaldehyde and acetaldehyde. The formation of acetaldehyde requires (i) the oxidation of 1 to a diazenium ion ( I ) or diazene ( II ) and (ii) fragmentation of I/II to formyl and methyl radicals. It is suggested that these radical intermediates may be important in understanding and elucidating carcinogenesis by 1 .

Saadet Büyükalaca - One of the best experts on this subject based on the ideXlab platform.

  • Determinaton of Volatile Aroma Components of Gyromitra Mushroom Using Headspace Gas Chromatography Mass Spectrometry (HS-GC/MS)
    Turkish Journal of Agriculture - Food Science and Technology, 2013
    Co-Authors: Hatıra Taşkın, Gökhan Baktemur, Ebru Kafkas, Saadet Büyükalaca
    Abstract:

    Gyromitra is one of the poisonous mushrooms with being evaluated as edible mushrooms in Turkey and in many countries. This study was performed to determine volatile aroma compounds of Gyromitra collected from Turkey at Horticulture Department of Cukurova University, Adana-Turkey in 2011. Gyromitra mushroom samples collected from Adana province of Turkey were used as material. Volatile aroma compounds were determined using Headspace Gas Kromotografi Mass Spectrometry (HS-GC/MS) technique. Twenty-four different volatile aroma compounds were detected in this study. Phenol was identified as the major aroma component at 47.10% content. This compound was followed with Carbamic acid methyl ester (14.12%), Acetic acid (4.47%), 1-Octen-3-ol (4.14%) and Acetaldehyde (4.10%). Phenol is an antioxidant compound and it has anti-carcinogenic effect. 1-Octen-3-ol is an alcohol which commonly found in mushroom. Acetic acid and Acetaldehyde are poisonous compounds. Although high number of phenol and 1-Octen-3-ol in Gyromitra fungus is displayed as flavor and significant in terms of health, containing toxic compounds such as acetic acid and the acid aldehyde raises the risk factors in exhaustion.

  • determinaton of volatile aroma components of Gyromitra mushroom using headspace gas chromatography mass spectrometry hs gc ms
    Turkish Journal of Agriculture: Food Science and Technology, 2013
    Co-Authors: Hatıra Taşkın, Gökhan Baktemur, Ebru Kafkas, Saadet Büyükalaca
    Abstract:

    Gyromitra is one of the poisonous mushrooms with being evaluated as edible mushrooms in Turkey and in many countries. This study was performed to determine volatile aroma compounds of Gyromitra collected from Turkey at Horticulture Department of Cukurova University, Adana-Turkey in 2011. Gyromitra mushroom samples collected from Adana province of Turkey were used as material. Volatile aroma compounds were determined using Headspace Gas Kromotografi Mass Spectrometry (HS-GC/MS) technique. Twenty-four different volatile aroma compounds were detected in this study. Phenol was identified as the major aroma component at 47.10% content. This compound was followed with Carbamic acid methyl ester (14.12%), Acetic acid (4.47%), 1-Octen-3-ol (4.14%) and Acetaldehyde (4.10%). Phenol is an antioxidant compound and it has anti-carcinogenic effect. 1-Octen-3-ol is an alcohol which commonly found in mushroom. Acetic acid and Acetaldehyde are poisonous compounds. Although high number of phenol and 1-Octen-3-ol in Gyromitra fungus is displayed as flavor and significant in terms of health, containing toxic compounds such as acetic acid and the acid aldehyde raises the risk factors in exhaustion.

Andrew N. Miller - One of the best experts on this subject based on the ideXlab platform.

  • Studies in Gyromitra I: the Gyromitra gigas species complex
    Mycological Progress, 2020
    Co-Authors: Andrew N. Miller, Angela Yoon, Gro Gulden, Øyvind Stensholt, Nicolas Vooren, Esteri Ohenoja, Andrew S. Methven
    Abstract:

    The Gyromitra gigas species complex includes six morphologically similar taxa, several of which have a long history of segregation, synonymization, and rearrangement among different genera. These taxa occur throughout Asia, Europe, and North America and include G. gigas , G. khanspurensis , G. korfii , G. montana , G. pseudogigas , and G. ticiniana . ITS and LSU sequences from 66 specimens, including type specimens for all six taxa, were included in phylogenetic analyses to establish species boundaries and resolve species relationships. Sequence similarity comparisons were also conducted between the two molecular markers and between the ITS1 and ITS2 regions. Although ITS exhibited sufficient variability to discriminate among species in the G. gigas species complex, LSU displayed very low variability rendering it completely useless as a molecular marker for separating taxa in this group. The ITS1 region was twice as informative as the ITS2 region and can be used as a barcode marker to identify these species. Gyromitra gigas and G. montana occur as a well-supported clade of sister species and can be distinguished based on ascospore morphology. Gyromitra korfii and G. ticiniana also form a highly supported clade and are considered distinct species based on geography. Gyromitra littiniana is confirmed to be synonymous with G. ticiniana based on molecular data. Gyromitra khanspurensis and G. pseudogigas , which also form a highly supported clade, are considered separate species early in the process of speciation that differ significantly in ascomata and ascospore morphology. A key to species based on morphology and geography is provided.

  • A molecular phylogenetic assessment of the genus Gyromitra in North America
    Mycologia, 2013
    Co-Authors: Andrew S. Methven, Steven E. Zelski, Andrew N. Miller
    Abstract:

    Gyromitra is a widespread genus of macroscopic apothecial ascomycetes whose taxa may be mycorrhizal, saprophytic or parasitic. Nuclear ribosomal 28S large subunit sequence data from 35 specimens from North America, along with sequences available in GenBank, were used in maximum-parsimony, maximum-likelihood and Bayesian analyses to reconstruct a phylogeny of Gyromitra in North America. Gyromitra sensu lato forms a monophyletic group within the Discinaceae composed of five distinct subgenera and 11 well supported clades that include Discina, Hydnotrya and Pseudorhizina. A new subgenus is proposed to accommodate G. californica and G. sphaerospora.

Stanley M Cichowicz - One of the best experts on this subject based on the ideXlab platform.

  • Toxic Mushroom Contamination of Wild Mushrooms in Commercial Distribution.
    Journal of food protection, 1993
    Co-Authors: John S Gecan, Stanley M Cichowicz
    Abstract:

    Poisonings caused by ingestion of toxic, wild-picked morel mushrooms have been reported to the Food and Drug Administration (FDA). Problems occur when collectors of wild mushrooms inadvertently include toxic look-alike species with the edible wild species offered for sale. A 2-year survey conducted by the FDA showed 21% of the morel and 15% of the wild mixed mushrooms were contaminated with toxic look-alike species. These contaminants contain toxins that produce symptoms ranging from dizziness and gastrointestinal distress to liver and heart damage. Present regulatory controls include FDA Import Alerts for morels contaminated with Gyromitra esculenta and Verpa bohemica , a Michigan state regulation requiring licensing of harvesters of wild mushrooms, and an Illinois state regulation prohibiting the sale of wild-picked mushrooms through retail outlets. American consumers, unable to distinguish between edible and toxic look-alike wild mushrooms, may face illness and possibly death from products purchased on the normally well-regulated U.S. consumer market.