Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Stud Mycol ; 98: 100116, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34466168

RESUMEN

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).

2.
Int J Food Microbiol ; 109(1-2): 121-6, 2006 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-16504326

RESUMEN

Aflatoxin contamination of food and grain poses a serious economic and health problem worldwide, but particularly in Africa. Aflatoxin B(1) (AFB(1)) is extremely mutagenic, toxic and a potent carcinogen to both humans and livestock and chronic exposure to low levels of AFB(1) is a concern. In this study, the biodegradation of aflatoxin B(1) (AFB(1)) by Rhodococcus erythropolis was examined in liquid cultures using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), electro spray mass spectrometry (ESMS) and liquid chromatography mass spectrometry (LCMS). AFB(1) was effectively degraded by extracellular extracts from R. erythropolis liquid cultures. Results indicated that the degradation is enzymatic and that the enzymes responsible for the degradation of AFB(1) are extracellular and constitutively produced. Furthermore, the biodegradation of AFB(1) when treated with R. erythropolis extracellular fraction coincided with a loss of mutagenicity, as evaluated by the Ames test for mutagenicity.


Asunto(s)
Aflatoxina B1/metabolismo , Biodegradación Ambiental , Contaminación de Alimentos/prevención & control , Rhodococcus/fisiología , Cromatografía Líquida de Alta Presión/métodos , Cromatografía en Capa Delgada/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Rhodococcus/metabolismo , Factores de Tiempo
3.
Int J Food Microbiol ; 105(2): 111-7, 2005 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-16061299

RESUMEN

Biological degradation of aflatoxin B(1) (AFB(1)) by Rhodococcus erythropolis was examined in liquid cultures and in cell-free extracts. Dramatic reduction of AFB(1) was observed during incubation in the presence of R. erythropolis cells (17% residual AFB(1) after 48 h and only 3-6% residual AFB(1) after 72 h). Cell-free extracts of four bacterial strains, R. erythropolis DSM 14,303, Nocardia corynebacterioides DSM 12,676, N. corynebacterioides DSM 20,151, and Mycobacterium fluoranthenivorans sp. nov. DSM 44,556(T) were produced by disrupting cells in a French pressure cell. The ability of crude cell-free extracts to degrade AFB(1) was studied under different incubation conditions. Aflatoxin B(1) was effectively degraded by cell free extracts of all four bacterial strains. N. corynebacterioides DSM 12,676 (formerly erroneously classified as Flavobacterium aurantiacum) showed the lowest degradation ability (60%) after 24 h, while >90% degradation was observed with N. corynebacterioides DSM 20,151 over the same time. R. erythropolis and M. fluoranthenivorans sp. nov. DSM 44,556(T) have shown more than 90% degradation of AFB(1) within 4 h at 30 degrees C, whilst after 8 h AFB(1) was practicably not detectable. The high degradation rate and wide temperature range for degradation by R. erythropolis DSM 14,303 and M. fluoranthenivorans sp. nov. DSM 44,556(T) indicate potential for application in food and feed processing.


Asunto(s)
Aflatoxina B1/metabolismo , Biodegradación Ambiental , Mycobacterium/fisiología , Rhodococcus/fisiología , Aflatoxina B1/antagonistas & inhibidores , Mycobacterium/metabolismo , Nocardia/metabolismo , Nocardia/fisiología , Rhodococcus/metabolismo , Temperatura , Factores de Tiempo
4.
Toxicon ; 30(7): 768-70, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1509495

RESUMEN

The fate of the mycotoxin, fumonisin B1, (FB1) dosed to rats by i.p. injection and by gavage was traced using 14C-labelled FB1. Twenty-four hours after i.p. injection, 66% of the radioactivity was recovered in faeces, 32% in urine, 1% in liver and trace amounts (less than 1%) in kidney and red blood cells. When dosed by gavage, all (101%) radioactivity was recovered in faeces and trace amounts were found in urine, liver, kidney and red blood cells. The bulk of the radioactivity recovered was unmetabolized FB1.


Asunto(s)
Carcinógenos Ambientales/farmacocinética , Fumonisinas , Micotoxinas/farmacocinética , Animales , Radioisótopos de Carbono , Masculino , Ratas , Distribución Tisular
5.
Toxicon ; 32(6): 735-41, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7940579

RESUMEN

Fumonisin B1 (FB1), a toxic and carcinogenic secondary metabolite of the fungus Fusarium moniliforme Sheldon, was administered either by i.v. injection or by gavage to vervet monkeys (Cercopithecus aethiops). FB1 dosed by i.v. injection to two female vervet monkeys was rapidly eliminated from plasma with a mean half-life during the elimination phase of 40 min. Analysis of urine and faeces over a 5 day period after dosing gave an average 47% recovery of the dose as FB1 and its hydrolysed analogues. Two female vervet monkeys were given a single gavage dose of 14C-labelled FB1. During the subsequent 3 day period, faecal excretion of radioactivity accounted for an average of 61% of the administered dose and urinary excretion 1.2%. Residual radioactivity was recovered in low levels from skeletal muscle (1%), liver (0.4%), brain (0.2%), kidney, heart, plasma, red blood cells and bile (each 0.1%), while the contents of the intestines accounted for a further 12% of the radioactive dose. In total, 76% of the administered radioactivity was recovered. Analysis of the faeces, intestinal contents and urine indicated that over 90% of the radioactivity in these samples was due to FB1 and its hydrolysis products.


Asunto(s)
Fumonisinas , Micotoxinas/farmacocinética , Administración Oral , Animales , Chlorocebus aethiops , Heces/química , Femenino , Inyecciones Intravenosas , Mucosa Intestinal/metabolismo , Micotoxinas/sangre , Micotoxinas/orina
6.
Soc Sci Med ; 45(2): 213-20, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9225409

RESUMEN

The aim of this study is to examine whether there is socioeconomic equity in health care utilization in Curaçao, Netherlands Antilles. We explore how educational level is related to utilization of GPs, specialists, hospitals; dentists and physiotherapists, taking into account the effects of sex, age and inequalities in health. The study also examines whether these relationships vary according to the unit of analysis: probability (or incidence) of services use versus overall volume of contacts. The data were derived from the Curaçao Health Study, a health interview survey among a random sample (N = 2248) of the non-institutionalized population aged 18 and over. The results indicate that there is socioeconomic inequity in the probability of health care utilization in Curaçao. People with a higher educational level are more likely to consult a specialist, dentist or physiotherapist, and are also more likely to be hospitalized. This is not only the case when the mediating effects of socioeconomic inequalities in health (need) are taken into account, but also before adjustment for health inequalities. In other words: there appears to be both vertical inequity (i.e. greater needs for services are not met by greater use) and horizontal inequity (i.e. similar needs for care are not met by similar levels of services use). The observed inequalities in use of specialists and hospitals contrast with findings from international research. The volume of health services use (i.e. the numbers of consultations) appears to be hardly connected with a person's position in the SES hierarchy; only dental services are used more extensively by higher educated individuals.


Asunto(s)
Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Indigencia Médica/estadística & datos numéricos , Grupo de Atención al Paciente/estadística & datos numéricos , Factores Socioeconómicos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Escolaridad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Antillas Holandesas , Revisión de Utilización de Recursos
7.
Eur J Clin Nutr ; 58(8): 1159-65, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15054429

RESUMEN

OBJECTIVES: To evaluate waist circumference (WC) as a screening tool for obesity in a Caribbean population. To identify risk groups with a high prevalence of (central) obesity in a Caribbean population, and to evaluate associations between (central) obesity and self-reported hypertension and diabetes mellitus. DESIGN: Cross-sectional. SETTING: Population-based study. SUBJECTS: A random sample of adults (18 y or older) was selected from the Population Registries of three islands of the Netherlands Antilles. Response was over 80%. Complete data were available for 2025 subjects. INTERVENTION: A questionnaire and measurements of weight, height, waist and hip. MAIN OUTCOME MEASUREMENT: Central obesity indicator (WC > or =102 cm men, > or =88 cm women). RESULTS: WC was positively associated with age (65-74 y vs 18-24 y) in men (OR=7.7, 95% CI 3.4-17.4) and women (OR=6.4, 95% CI 3.2-12.7). Women with a low education had a higher prevalence of central obesity than women with a high education (OR=0.5, 95% CI 0.3-0.7). However, men with a high income had a higher prevalence of a central obesity than men with a low income (OR=1.7, 95% CI=1.1-2.6). WC was the strongest independent obesity indicator associated with self-reported hypertension (OR=1.7, 95% CI 1.4-2.0) and diabetes mellitus (OR=1.6, 95% CI 1.3-1.9). CONCLUSIONS: The identified risk groups were women aged 55-74 y, women with a low educational level and men with a high income. WC appears to be the major obesity indicator associated with hypertension and diabetes mellitus. SPONSORSHIP: Island Governments of Saba, St Eustatius and Bonaire, the Federal Government of the Netherlands Antilles, Dutch Directorate for Kingdom relationships.


Asunto(s)
Constitución Corporal/fisiología , Diabetes Mellitus Tipo 2/epidemiología , Hipertensión/epidemiología , Obesidad/epidemiología , Obesidad/fisiopatología , Adulto , Factores de Edad , Anciano , Intervalos de Confianza , Estudios Transversales , Diabetes Mellitus/epidemiología , Diabetes Mellitus Tipo 2/etiología , Escolaridad , Femenino , Encuestas Epidemiológicas , Humanos , Hipertensión/etiología , Renta , Masculino , Persona de Mediana Edad , Antillas Holandesas/epidemiología , Obesidad/diagnóstico , Oportunidad Relativa , Factores de Riesgo , Factores Sexuales , Encuestas y Cuestionarios
8.
Food Chem Toxicol ; 32(7): 627-32, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8045475

RESUMEN

An in vitro study on the interaction and biotransformation of the [14C]fumonisin B mycotoxins was conducted, using primary rat hepatocyte cultures and subcellular enzyme preparations. At the same concentration, fumonisin B2 (FB2) exhibited a higher cytotoxicity and specific binding to primary rat hepatocytes than fumonisin B1 (FB1). However, if the effective dose level (EDL) is considered (i.e. the lowest level of toxin that binds to the hepatocytes to elicit a cytotoxic effect), FB1 and FB2 exhibited a similar cytotoxic effect. FB1 was found to be associated with both the soluble and insoluble compartments within the cell. As assessed by the radioactivity associated with the cellular preparations, very little (approximately 0.01%) FB1 and/or FB2 bound to hepatocytes. In the subsequent fractionation of the culture medium using amberlite XAD-2 and silica-gel chromatography, no metabolites were detected, indicating that the fumonisin molecule was not metabolized by primary hepatocytes. The latter aspect was confirmed by the fact that incubation of FB1 with microsomal enzyme preparations also failed to indicate any metabolism of the fumonisins by the esterases or by cytochrome P-450 monooxygenase. FB1 was also found not to be a substrate for the triglyceride hepatic endothelial lipase, nor for a lipase from porcine pancreas. This study supports further the hypothesis that the intact molecule of the fumonisins is required for biological activity.


Asunto(s)
Fumonisinas , Hígado/efectos de los fármacos , Micotoxinas/farmacología , Animales , Biotransformación , Células Cultivadas , Técnicas In Vitro , Hígado/metabolismo , Masculino , Micotoxinas/farmacocinética , Ratas , Ratas Endogámicas F344 , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/metabolismo
9.
Food Chem Toxicol ; 32(1): 23-9, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8132161

RESUMEN

A method has been developed for the determination of fumonisin B1 (FB1) in the faeces of non-human primates (vervet monkeys). The animals were dosed with 14C-labelled FB1, and the radioactive compounds in faeces were recovered by repeated extractions with 0.1 M ethylenediaminetetraacetic acid. The extracts were cleaned-up on a reversed-phase (C18) solid-phase extraction cartridge, and FB1 was determined by o-phthaldialdehyde derivatization and reversed-phase HPLC. The analytical method for the determination of FB1 in the faecal extracts was reproducible [2.6% relative standard deviation (RSD)] and accurate (recovery from spiked blank extracts of 93 +/- 2.9% RSD). Confirmation of the identification of FB1 in faeces was achieved using HPLC and thin-layer chromatography, which showed that the radioactivity extracted corresponded mainly to FB1 and a new metabolite with chromatographic properties similar to those of the mycotoxin. The new metabolite was identified by mass spectrometry and nuclear magnetic resonance spectroscopy to be an equilibrium mixture of the two structural isomers of partially hydrolysed FB1, which are formed by hydrolysis of one of the ester groups of the mycotoxin.


Asunto(s)
Heces/química , Fumonisinas , Micotoxinas/análisis , Animales , Radioisótopos de Carbono , Chlorocebus aethiops , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Femenino , Hidrólisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Micotoxinas/química , Micotoxinas/metabolismo , Ratas , o-Ftalaldehído
10.
Food Chem Toxicol ; 32(5): 489-91, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8206448

RESUMEN

The biliary excretion of the mycotoxin fumonisin B1 (FB1), produced by the fungus Fusarium moniliforme Sheldon, has been measured in male Wistar rats. After ip injection of a solution of FB1 (7.5 mg/kg body weight), 67% of the applied dose was recovered in bile over a 24-hr period, 88% of this recovery being excreted in the first 4 hr after dosing. In contrast to these results, a similar dose of FB1 given by gavage resulted in only 0.2% recovery of the toxin in bile over a 24-hr period. Hence, although these results show that biliary excretion is a major route of elimination of FB1 from the circulation, only small amounts of the toxin appeared to be absorbed from the gut in rats.


Asunto(s)
Bilis/metabolismo , Fumonisinas , Micotoxinas/farmacocinética , Animales , Radioisótopos de Carbono , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Masculino , Ratas , Ratas Wistar , Conteo por Cintilación
11.
Health Policy ; 44(1): 57-72, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10180202

RESUMEN

In this study, we test the assumption that sociocultural differences in use of health services will only occur below a certain level of illness severity. Data are derived from the Curaçao Health Study (n = 2248). Subjects' educational level and degree of proto-professionalization are used as indicators of their sociocultural background. Differences in the likelihood of seeking professional care for several common health problems are analyzed, and are compared with the help-seeking behavior for chronic disorders. As hypothesized, higher educated and proto-professionalized people are less likely to seek care for everyday symptoms. In addition, proto-professionalization is accompanied by a greater likelihood of using over the counter medication. Increasing empowerment of patients appears to lead to increased self care for everyday symptoms. When conditions reach a more serious stage, the differences in help-seeking behavior disappear: for most of the chronic conditions studied, the higher educated and more proto-professionalized individuals are just as likely to seek professional treatment as the less advantaged groups. However, there is a difference as to the type of professional consulted for chronic health problems. Proto-professionalized individuals more often receive specialist treatment, probably because they are better equipped to persuade GPs to refer. The adverse side of patient empowerment may be increasing consumerism: a situation in which patient demands, not medical necessity, determine the care delivered.


Asunto(s)
Actitud Frente a la Salud , Aceptación de la Atención de Salud/etnología , Enfermedad Aguda , Enfermedad Crónica , Características Culturales , Humanos , Entrevistas como Asunto , Funciones de Verosimilitud , Antillas Holandesas , Aceptación de la Atención de Salud/estadística & datos numéricos , Poder Psicológico , Autocuidado , Clase Social , Factores Socioeconómicos
12.
West Indian Med J ; 46(1): 8-14, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9149545

RESUMEN

The Curaçao Health Study was carried out among a randomized sample (n = 2248, response rate = 85%) of the adult non-institutionalized population in order to assess aspects of lifestyle that may pose health risks. Factors examined were tobacco and alcohol use, eating habits and exercise behaviour. Outcome variables were cross-tabulated by gender, age and socioeconomic status. 17.1% of the participants were smokers and 20.5% were regular drinkers, including 6.3% of the men who consumed alcohol excessively (4 or more glasses of alcohol a day). 75% of the participants did not exercise regularly, 37% did not eat vegetables daily, and half did not eat fruit daily. Other poor eating habits were the addition of extra sugar and salt to prepared food by 33% and 20% of the participants, respectively. On the whole, men had less healthy lifestyles than women, with the exception of exercise behaviour. People of high socioeconomic status (SES) drank less alcohol, and exercised more often than those of low SES. Considering the high prevalence of diabetes mellitus and hypertension in the Caribbean, research on lifestyle factors in other Caribbean countries is required to facilitate the development of regional prevention and intervention programmes.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Ejercicio Físico , Conducta Alimentaria , Estilo de Vida , Fumar/epidemiología , Adolescente , Adulto , Anciano , Dieta , Femenino , Humanos , Masculino , Persona de Mediana Edad , Antillas Holandesas/epidemiología
13.
Int J Food Microbiol ; 135(1): 47-52, 2009 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-19683355

RESUMEN

The enzymatic degradation of aflatoxin B(1) (AFB(1)) by white rot fungi through laccase production was investigated in different liquid media. A significant (P<0.0001) correlation was observed between laccase activity and AFB(1) degradation exhibited by representatives of Peniophora and Pleurotus ostreatus cultivated in minimal salts (MSM) (r=0.93) and mineral salts - malt extract (MSB-MEB) (r=0.77) liquid media. Peniophora sp. SCC0152 cultured in MSB-MEB liquid medium supplemented with veratryl alcohol and sugarcane bagasse showed high laccase activity (496U/L), as well as 40.45% AFB(1) degradation as monitored using high performance liquid chromatography. P.ostreatus St2-3 cultivated in MSM liquid medium supplemented with veratryl alcohol resulted in laccase activity of 416.39U/L and 35.90% degradation of AFB(1). Aflatoxin B(1) was significantly (P<0.0001) degraded when treated with pure laccase enzyme from Trametes versicolor (1U/ml, 87.34%) and recombinant laccase produced by Aspergillus niger D15-Lcc2#3 (118U/L, 55%). Aflatoxin B(1) degradation by laccase enzyme from T. versicolor and recombinant laccase enzyme produced by A. niger D15-Lcc2#3 coincided with significant (P<0.001) loss of mutagenicity of AFB(1), as evaluated in the Salmonella typhimurium mutagenicity assay. The degradation of AFB(1) by white rot fungi could be an important bio-control measure to reduce the level of this mycotoxin in food commodities.


Asunto(s)
Aflatoxina B1/metabolismo , Basidiomycota/enzimología , Conservación de Alimentos/métodos , Lacasa/metabolismo , Antibiosis , Basidiomycota/metabolismo , Alcoholes Bencílicos/metabolismo , Celulosa/metabolismo , Cromatografía Líquida de Alta Presión , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Medios de Cultivo/química , Lacasa/biosíntesis , Pleurotus/enzimología , Pleurotus/metabolismo , Polyporales/enzimología , Polyporales/metabolismo , Trametes/enzimología , Trametes/metabolismo
14.
Mycotoxin Res ; 9(1): 2-12, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23606061

RESUMEN

The extraction and purification methods used in the maleyl derivatization HPLC technique was evaluated with respect to the pH of the extraction mixture, the extraction solvent and the purification methods used in order to determine optimum conditions for quantification of fumonisins B1, B2, and B3 in corn cultures. The highest recovery of the three compounds was obtained by extraction at pH 3.5 with CH3OH-H20 (3∶1), whilst the subsequent solvent partitioning and reversedphase C18 Sep-pak purification have been shown to be very important in the quantification of the fumonisins in the corn cultures. The percentage recovery of the improved technique, utilizing a gradient HPLC solvent system for the simultaneous determination of the fumonisins, was 93.4% for FB1, 68.0% for FB2, and 82.6% for FB3. The study indicates that the polarity of the fumonisins and consequently their solubility during extraction as well as their behavior during the subsequent purification step play an important role in quantification of these mycotoxins in corn cultures.

15.
Appl Environ Microbiol ; 59(8): 2673-7, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8368853

RESUMEN

Kinetics of growth and fumonisin production by Fusarium moniliforme MRC 826 in corn "patty" cultures were investigated, and a technique was developed for the production of [14C]fumonisin B1 ([14C]FB1) by using L-[methyl-14C]methionine as the precursor. A significant (P < 0.01) correlation exists between fungal growth and FB1 (r = 0.89) and FB2 (r = 0.87) production in corn patties, beginning after 2 days and reaching the stationary phase after 14 days of incubation. [14C]FB1 was produced by adding L-[methyl-14C]methionine daily to cultures during the logarithmic phase of production. Incorporation of the isotope occurred at C-21 and C-22 of the fumonism molecule and was enhanced in the presence of unlabeled L-methionine. Although the concentration of exogenous unlabeled methionine is critical for incorporation of the 14C label, optimum incorporation was achieved by adding 50 mg of unlabeled L-methionine and 200 mu Ci of L-[methyl-14C]methionine to a corn patty (30 g) over a period of 9 days, yielding [14C]FB1 with a specific activity of 36 mu Ci/mmol.


Asunto(s)
Fumonisinas , Fusarium/metabolismo , Micotoxinas/biosíntesis , Radioisótopos de Carbono , Fusarium/crecimiento & desarrollo , Cinética , Metionina/metabolismo , Micología/métodos , Micotoxinas/química , Zea mays/microbiología
16.
Mycotoxin Res ; 10(2): 107-15, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23605972

RESUMEN

Production of fumonlsins B1 (FB1) and B2 (FB2) by 5 lyophillzation batches ofFusarium moniliforme strain MRC 826 was studied in several liquid media and vermlculite supplemented with liquid media. In addition the effect of different parameters including pH, Inert material, shake versus stationary cultures as well as different carbon sources on the production of the fumonlsins were investigated. Fumonlsin production in liquid cultures was significantly (P<0.01) correlated (r=0.92-0.98) with fungal growth, which in turn is affected by the pH of the medium as well as the carbon source utilized. The highest FB1 yields (approximately 40 mg/l) over the incubation period of 14 days were produced in a chemically defined medium with glucose as carbon source set at an initial pH value of 4. FB1 production in "corn patty" cultures (approximately 1 to 3 g/kg), however, by far exceeded that obtained in the liquid media, while poor fungal growth and fumonlsin production was obtained in vermlculite supplemented cultures. From these studies it became clear that the ability of a culture to produce fumonlsins is determined by the interaction of a variety of physiological and nutritional factors regarding the inoculum and the culture medium.

17.
Appl Environ Microbiol ; 56(6): 1729-33, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2383011

RESUMEN

The kinetics of the production of fumonisin B1 (FB1) by Fusarium moniliforme MRC 826 in corn cultures was investigated as a function of fungal growth at various incubation temperatures. The growth rate of F. moniliforme, as measured by ergosterol concentration, was higher at 25 degrees C than at 20 degrees C, reaching a stationary phase after 4 to 6 weeks in both cases. FB1 production commenced after 2 weeks during the active growth phase, continued to increase during the stationary phase, and decreased after 13 weeks. The overall maximal yield of FB1 (17.9 g/kg, dry weight) was obtained in corn cultures incubated at 20 degrees C for 13 weeks, but it was not significantly (P greater than 0.05) higher than the maximum yield (16.5 g/kg, dry weight) obtained at 25 degrees C after 11 weeks. However, a significantly (P less than 0.05) higher mean yield was detected at 25 degrees C (9.5 g/kg, dry weight) than at 20 degrees C (8.7 g/kg, dry weight). Production reached a plateau after 7 weeks of incubation at 25 degrees C or 9 weeks of incubation at 20 degrees C. The maximal production of FB1 at 30 degrees C was very low (0.6 g/kg, dry weight). FB1 was also found to be heat stable, as there was no reduction in the FB1 concentration after boiling culture material of F. moniliforme MRC 826.


Asunto(s)
Carcinógenos Ambientales/metabolismo , Fumonisinas , Fusarium/metabolismo , Micotoxinas/biosíntesis , Cromatografía Líquida de Alta Presión , Fusarium/crecimiento & desarrollo , Cinética , Temperatura , Zea mays/microbiología
18.
Int J Obes Relat Metab Disord ; 21(11): 1002-9, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9368823

RESUMEN

OBJECTIVE: The aim of the article is to report the prevalence of obesity, abdominal fatness and waist circumference in different socioeconomic classes in Curaçao. DESIGN: In 1993/1994 a health interview survey (the Curaçao Health Study) was carried out among a random sample (n = 2248, response rate = 85%) of the adult non-institutionalized population of Curaçao. METHODS: We analyzed the association between obesity (BMI > or = 30), abdominal fatness (waist hip ratio (WHR) > or = 0.95 for men, WHR > or = 0.80 for women) waist circumference (WC > or = 100 cm for men, WC > or = 91 cm for women) and socioeconomic status (SES) by age adjusted logistic regressions, for men and women separately. RESULTS: The prevalence of obesity was about 27%: 36% of the women and 19% of the men were obese. An at risk WHR was reported among 62.2% of the women and among 20.4% of the men. A WC above the cut-off point was reported for 44.3% women and 25.3% men. Compared to women of higher SES, the lower SES women have a two to three times higher risk of a BMI, WHR or WC exceeding the cut-off points. Among men, no statistically significant difference between an increased BMI, WHR or WC and SES factors was found. The overlap between the three measures is large, about 56% of the women scored similarly on all three measurements. Among men the overlap is even greater (73%). CONCLUSIONS: The prevalence of obesity in Curaçao is alarming. Low SES women are at the greatest risk of an increased BMI, WHR or WC. The obesity figures can be placed between industrialized societies and less modernized cultures. Action and additional research on the prevention of obesity in Curaçao are deemed necessary. The cut-off points in our study for WC in the non-white population are preliminary and need to be elucidated further.


Asunto(s)
Obesidad/epidemiología , Clase Social , Adulto , Factores de Edad , Anciano , Constitución Corporal , Índice de Masa Corporal , Escolaridad , Femenino , Humanos , Renta , Modelos Logísticos , Masculino , Persona de Mediana Edad , Antillas Holandesas/epidemiología , Ocupaciones , Prevalencia , Factores Sexuales , Encuestas y Cuestionarios
19.
West Indian med. j ; 46(1): 8-14, Mar. 1997.
Artículo en Inglés | LILACS | ID: lil-193491

RESUMEN

The Curacao Health Study was carried out among a randomized sample (n = 2248, response rate = 85 percent) of the adult non-institutionalized population in order to assess aspects of lifestyle that may pose health risks. Factors examined were tobacco and alcohol use, eating habits and exercise behaviour. Outcome variables were cross-tabulated by gender, age and socioeconomic status. 17.1 percent of the participants were smokers and 20.5 percent regular drinkers, including 6.3 percent of the men who consumed alcohol excessively (4 or more glasses of alcohol a day). 75 percent of the participants did not excercise regularly, 37 percent did not eat vegetables daily, and half did not eat fruit daily. Other poor eating habits were the addition of extra sugar and salt to prepared food by 33 percent and 20 percent of the participants, respectively. On the whole, men had less healthy lifestyles than women, with the exception of execise behaviour. People of high socioeconomic status (SES) drank less alcohol, and exercised more often than those of low SES. Considering the high prevalence of diabetes mellitus and hypertension in the Caribbean, research of lifestyle factors in other Caribbean countries is required to facilitate the development of regional prevention and intervention programmes.


Asunto(s)
Adulto , Femenino , Humanos , Persona de Mediana Edad , Consumo de Bebidas Alcohólicas/epidemiología , Ejercicio Físico , Fumar/epidemiología , Estilo de Vida , Factores Socioeconómicos , Factores Sexuales , Indicadores de Morbimortalidad , Factores de Riesgo , Escolaridad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA