RESUMO
To estimate daily intake of aflatoxins from peanut products consumed by the population of Paraná State (Brazil), 100 samples of peanut products were collected between July 2006 and April 2007. Aflatoxins were determined by an HPLC method with fluorescence detection. There was a 50% occurrence of aflatoxins (B1, B2, G1 and G2) in concentrations ranging from 0.5 to 113 ng g(-1), with 13 samples with levels above 20 ng g(-1). Intake was calculated for average and high adult consumers of peanut products and it was compared with provisional maximum tolerable daily intake (PMTDI). The estimated probable daily intake (PDI) for aflatoxin B1 (AFB1) varied from 0.6 to 10.4 ng kg(-1) bw day(-1), exceeding the PMTDI of 0.4 ng kg(-1) bw day(-1) for carriers of hepatitis B virus.
Assuntos
Aflatoxinas/análise , Arachis/química , Dieta , Exposição Ambiental , Contaminação de Alimentos/análise , Brasil , Cromatografia Líquida de Alta Pressão , Controle de Qualidade , Espectrometria de Fluorescência , Inquéritos e QuestionáriosRESUMO
Fifty-two isolates of Fusarium species and one of Gibberella fujikuroi were tested for galactose oxidase (GO) production. Five Fusarium isolates contained GO activity in the culture filtrate: three F. graminearum and one each F. moniliforme f. sp. subglutinans and F. acuminatum. This is the first time F. acuminatum is reported to be a producer of GO enzyme. GO enzyme activity produced by isolates was assayed through a time course. Moreover, GO protein was partially purified from the most productive four isolates to show that the activity measured in the culture filtrates was due to the presence of GO protein.
Assuntos
Fusarium/classificação , Fusarium/enzimologia , Galactose Oxidase/biossíntese , Meios de Cultura , Galactose Oxidase/isolamento & purificação , Fatores de TempoRESUMO
The galactose oxidase-producing fungus Dactylium dendroides was re-identified as a Fusarium species. Fungi of this genus are well known for the production of mycotoxins. Verification of growth of this fungus on rice, corn and liquid medium described for the production of galactose oxidase is provided to determine whether the fungus could produce Fusarium toxins, namely, moniliformin, fusaric acid, fumonisin, zearalenone and the trichothecenes, deoxynivalenol, 3-acetyldeoxynivalenol, fusarenone, nivalenol, diacetoxyscirpenol, neosolaniol, and toxin T-2. Under the culture conditions used, deoxynivalenol, 3-acetyldeoxynivalenol and zearalenone were detected in the fungal culture medium. The finding is consistent with the hypothesis that the fungus is in fact a Fusarium species.
Assuntos
Fusarium/metabolismo , Galactose Oxidase/biossíntese , Micotoxinas/biossíntese , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Fusarium/enzimologia , Fusarium/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Micotoxinas/análise , Micotoxinas/toxicidade , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Testes de Irritação da Pele , Tricotecenos/análise , Tricotecenos/biossíntese , Tricotecenos/toxicidade , Zearalenona/análise , Zearalenona/biossíntese , Zearalenona/toxicidadeRESUMO
A Leishmania brasiliensis e um dos agentes causadores da Leishmaniose Tegumentar Americana (LTA). A cepa 034-jcg, isolada de paciente da regiao norte do estado do Parana, Brasil, foi cultivada em meio Blood Agar Base, liofilizada e submetida a extracao com fenol-agua e o extrato obtido foi tratado com RNase I. O antigeno contendo carboidrato (AgCHO) mostrou-se imunogenico para coelhos e apresentou pelo menos uma fracao com poucas cargas negativas em pH 8,2. Este antigeno apresenta reacao cruzada com extrato fenolico do meio de cultura usado para o cultivo de promastigotas...
Assuntos
Animais , Masculino , Ratos , Antígenos/isolamento & purificação , Carboidratos/isolamento & purificação , Leishmaniose/imunologia , Leishmania braziliensis/metabolismo , Testes Imunológicos/métodosRESUMO
Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL). The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treated with RNase I. The carbohydrate containing-antigen (Ag-CHO) was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100 degrees C for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.
Assuntos
Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Animais , Antígenos de Protozoários/química , Antígenos de Protozoários/isolamento & purificação , Brasil , Carboidratos/análise , Colorimetria/métodos , Epitopos , Imunofluorescência , Imunodifusão , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Masculino , CoelhosRESUMO
Histoplasma capsulatum var. capsulatum is a dimorphic fungus that, under special conditions, converts from its more common mycelial form to a yeast-like form. Achieving this conversion, however, has been problematical for researchers. The present study tested conversion rates in ten Histoplasma capsulatum var. capsulatum strains using seven culture media, four of wich were conventional and three novel. One of our novel media, MLGema, induced complete conversion, of two strains within five days of incubation at 35 degrees centigrades, and of all strains that eventually converted by the time of the second subculturing transfer, under defined experimental conditions. MLGema is also inexpensive and easy to produce
Assuntos
Histoplasma/fisiologia , Histoplasmose/prevenção & controle , Histoplasma/análise , Histoplasma/crescimento & desenvolvimentoRESUMO
Histoplasma capsulatum var. capsulatum is a dimorphic fungus that, under special conditions, converts from its more common mycelial form to a yeast-like form. Achieving this conversion, however, has been problematical for researchers. The present study tested conversion rates in ten Histoplasma capsulatum var. capsulatum strains using seven culture media, four of which were conventional and three novel. One of our novel media, MLGema, induced complete conversion of two strains within five days of incubation at 35 degrees C, and of all strains that eventually converted by the time of the second subculturing transfer, under defined experimental conditions. MLGema is also inexpensive and easy to produce.
Assuntos
Meios de Cultura , Histoplasma/crescimento & desenvolvimento , Micologia/métodos , TemperaturaRESUMO
Zearalenone, a natural product isolated from Fusarium graminearum, has anabolic properties and affects glycogen catabolism in the rat liver. In the isolated perfused liver, L-lactate production, glucose release from endogenous glycogen and oxygen uptake are increased upon infusion of the compound. Fructose metabolism is only slightly affected by zearalenone, except for the transformation of fructose into glucose which is decreased. The action of zearalenone seems to be related to the amount of drug retained by the liver rather than to the concentration in the perfusion fluid.
Assuntos
Frutose/metabolismo , Glucose/metabolismo , Fígado/metabolismo , Resorcinóis/farmacologia , Zearalenona/farmacologia , Animais , Metabolismo Energético/efeitos dos fármacos , Glicogênio Hepático/biossíntese , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Perfusão , Ratos , Ratos EndogâmicosRESUMO
Zearali, a natural product isolated from Fusarium granunearum, has anabolic properties and effects glycogen catabolism in the rat liver. In the isolated perfused liver, L-lactate production, glucose release from endogenous glycogen and oxygen uptake are increased upon infusion of the compound. Fructose metabolism is only slightly affected by zearalenone, except for the transformation of fructose intoglucose which is decreased. The actiohn of zearalenone seems to be related to the amount of drug retained by the liver rather than to the concentration in the perfusion fluid