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Biomedical subjects

J L Richard

Publications and source records attributed to J L Richard.

At least 55 records · Page 3Linked to original sources
PubMed1994

Gliotoxin inhibits transformation and its cytotoxic to turkey peripheral blood lymphocytes.

Gliotoxin, an epipolythiodioxopiperizine mycotoxin, has been shown to be produced by, among other fungi, Aspergillus fumigatus Fresenius. This organism is the major causative agent of the respiratory disease aspergillosis in avian species, especially turkeys. Because gliotoxin has been shown to be immunosuppressive and has the potential for being involved in the pathogenesis of aspergillosis, the in vitro activity of this compound with avian lymphocytes was investigated. Immunosuppression was investigated using peripheral blood lymphocytes from turkeys in a lymphoblastogenesis assay and a cytotoxicity assay using conversion of the tetrazolium salt MTT to MTT formazan by the mitochondrial succinate dehydrogenase enzyme elaborated only by living cells. Gliotoxin appeared to have a threshold level in both tests because little or no response or stimulation was evident when cells were exposed to concentrations of the toxin below 100 ng/ml, but at 100 ng/ml, all cells appeared to be dead. Using T-2 mycotoxin as a known cytotoxic agent, the response in the MTT bioassay using turkey peripheral lymphocytes was linear with increasing concentrations of toxin. Gliotoxin may potentially cause immunosuppression in turkey poults through action on the lymphocytes or if this toxin were present in low concentrations stimulation could possibly occur.

Animals↗
PubMed1994

Chrysosporium tropicum as a probable cause of mycosis of poultry in India.

Chrysosporium tropicum was isolated from comb lesions in two different breeds of chickens in India and subcultures were shown to be pathogenic when inoculated onto prepared skin of guinea pigs. This report provides additional evidence to consider Ch. tropicum as a pathogenic fungus and a probable cause of a dermatomycosis in chickens.

Animals↗
PubMed1994

Myocardial infarction case-fatality gradient in three French regions: the influence of acute coronary care.

The objective of this study was to evaluate the influence of acute coronary care on the myocardial infarction (MI) case-fatality gradient observed in three French regions. In 1989, a total of 813 hospitalized events of premature MI, occurring in men and women aged 25-64, were registered in three WHO-MONICA sites established in Lille (North of France), Strasbourg (East of France) and Toulouse (South of France). The case-fatality rates observed 28 days after the onset of the MI, were 30.6% in Lille, 17.5% in Strasbourg and 9.9% in Toulouse (P < 0.0001). We compared the management of events and the use of cardiovascular therapies in these centres before admission to hospital, during the stay and on discharge from hospital. Differences were observed between the three centres in the use of medical treatments: in Strasbourg, aspirin and antiplatelet agents were prescribed 15% less frequently, (P < 0.0001) while diuretics were prescribed twice as often as in Toulouse (P < 0.0001). Thrombolytic agents (P < 0.01) and invasive techniques (coronary angiography, coronary angioplasty and coronary bypass surgery) (P < 0.0001) were more widely used in Toulouse compared with the two other centres. Lille might have a higher rate of coronary case fatality than Strasbourg and Toulouse because of a series of cumulative characteristics. The disease presented in a more serious form: more frequent electrocardiographic changes in anterior leads (P < 0.02), higher percentage of use of inotropic drugs in association with diuretic agents (P < 0.04), and longer duration of stay in intensive care units (P < 0.0001). However, when case-fatality rates were adjusted for all these variables in a multivariate model, the rate remained significantly higher in Lille than in the two other centres (P < 0.0001), as suggested by the odds ratio (3.27, 95% confidence interval: 1.69-6.32). In conclusion, the influence of acute coronary care on the MI case-fatality gradient observed between the North and South of France is very weak.

Acute Disease↗
PubMed1994

Effect of building ventilation design on environment and performance of turkeys.

Environmental variables in 10 commercial turkey confinement buildings, representing 2 natural ventilation designs, were measured during summer and the following winter. Sliding doors spaced at intervals along the walls of 5 of the buildings provided about 35% opening, and continuous wall curtains provided 60 to 80% opening in the other 5 buildings. Environmental variables assessed included airspeed; temperature; relative humidity; gases; particle number, size, and mass per cubic meter of air; and colonies of bacteria, yeasts, and other fungi per cubic meter of air. Colonies of yeasts and other fungi were quantitated in feed and litter. For most of the variables evaluated, significant differences were not attributable to building ventilation design; however, in winter, the total mass of particulate matter per cubic meter of air was higher in the curtain-type houses, compared with sliding door-type houses. Ammonia concentration in the air of sliding door-type houses progressively increased during summer and winter sampling periods. A significant effect of building ventilation design on turkey performance was not detected when using mortality, average daily gain, feed conversion, condemnations at slaughter, or average individual bird weight as measures of production.

Air↗
PubMed1993

Risk factors for early death in non-insulin dependent diabetes and men with known glucose tolerance status.

OBJECTIVE: To identify risk factors for all cause mortality according to glucose tolerance status. DESIGN: Cohort study with an average 15.6 years' follow up. SETTING: Paris, France. SUBJECTS: 7166 working men aged 44-55 in 1968-72 in the Paris prospective study cohort, with non-insulin dependent diabetes or known result of two hour 75 g oral glucose tolerance test. MAIN OUTCOME MEASURES: Risk factors for death from all causes. RESULTS: 128 men were known to be diabetic, 180 had diabetes diagnosed, and 697 had impaired glucose tolerance diagnosed. Compared with normoglycaemic men the relative risks of death in these groups were 2.0 (95% confidence interval 1.4 to 3.0), 2.7 (2.0 to 3.6), and 1.6 (1.3 to 2.0) respectively. Obesity, smoking, high blood pressure, and high non-esterified fatty acid concentration were risk factors for death in all subjects and were unaffected by glucose tolerance. The risks for fasting and two hour insulin concentrations and mean corpuscular volume were two times higher in known diabetic men than in men not known to be diabetic. Central obesity was significant only in men not known to be diabetic (1.6 (1.4 to 1.9)). In known diabetic men a two hour glucose concentration higher than 11.1 mmol/l carried a relative risk of death of 3.8 (1.4 to 9.4). CONCLUSIONS: Diabetic men have similar risk factors for early mortality to other men but are at higher risk from hyperinsulinaemia, hyperglycaemia, and high mean corpuscular volume.

Adult↗
PubMed1993

Lymphocyte cytotoxicity and erythrocytic abnormalities induced in broiler chicks by fumonisins B1 and B2 and moniliformin from Fusarium proliferatum.

Peripheral blood lymphocytes were isolated from broiler chicks that had ingested feed amended with autoclaved Fusarium proliferatum culture material containing fumonisin B1 (FB1), fumonisin B2 (FB2) and moniliformin. Lymphocyte viability was determined for birds that were placed on amended rations at day 1 or day 7 of age at three different levels of mycotoxins, ranging from 61-546 ppm FB1, 14-94 ppm FB2 and 66-367 ppm moniliformin. Reduction of the tetrazolium salt, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], to yield MTT formazan, based on mitochondrial metabolic activity, was used to assess cell viability. Lymphocyte cytotoxic effects were observed in all treatment groups on day 21; chicks that started on amended feed at day 1 of age were affected more than those that started at day 7. Abnormal erythrocytes resembling early stages of erythroblasts were observed in peripheral blood from test chicks. Abnormally shaped red cells (poikilocytes) having a spindle-shape with one or both ends pointed were present. Some red cells appeared to be undergoing mitosis. Both reduced lymphocyte viability and abnormal erythrogenesis occurred in chicks given feed amended with F. proliferatum culture material containing FB1, FB2 and moniliformin.

Animal Feed↗
PubMed1993

Mortality in broiler chicks on feed amended with Fusarium proliferatum culture material or with purified fumonisin B1 and moniliformin.

Two hundred twenty-eight male chicks (Columbia x New Hampshire) were given feed amended with autoclaved culture material (CM) of Fusarium proliferatum Containing fumonisin B1 (FB1), fumonisin B2 (FB2) and moniliformin in 3 separate feeding trials. Purified FB1 and moniliformin were given separately and in combination in a fourth feeding trial. Birds were given amended rations at day 1 (Trial 1 and 4), day 7 (Trial 2), and day 21 (Trial 3) and their respective ration was given for 28 days (Trial 1), 21 days (Trial 2), 7 days (Trial 3), and 14 days (Trial 4). FB1 concentrations were 546, 193, and 61 ppm; FB2 were 98, 38 and 14 ppm; and moniliformin were 367, 193, and 66 ppm in the first 3 feeding trial regimens. Chicks in Trial 4 were given dietary concentrations of purified FB1 at 274 and 125 ppm, and moniliformin at 154 and 27 ppm. FB1 and moniliformin, both alone and in combination, produced dose-responsive clinical signs, reduced weight gains and mortality in chicks. Age of birds given amended feeds had little difference in the clinical response; however, those given the rations from days 7 or 21 were slightly less susceptible than those given rations beginning at 1 day of age. Additive effects were noted when the toxins were given in combination. When toxins were given separately, adverse effects took longer to occur. A system to monitor pattern and rate of defecation (RD) was developed for assessing the chicks' approach to feed, water and heat source as illness progressed. Our results indicate that chicks fed corn heavily infected with F. proliferatum under field conditions could suffer acute death similar to that described for 'spiking mortality syndrome' during the first 3 weeks of age.

Animal Feed↗
PubMed1993

Embryopathic and embryocidal effects of purified fumonisin B1 or Fusarium proliferatum culture material extract on chicken embryos.

One hundred eight fertile eggs (Columbia x New Hampshire) were assigned to 10 groups of 10 eggs each (2 control groups had 14 eggs each). Five groups of eggs were inoculated on day 1 of incubation, while the other 5 groups were inoculated on day 10. The inoculum of the 4 treatment groups on both day 1 and 10 consisted of 1,10, or 100 microM purified fumonisin B1 (FB1) or a culture material extract (CME) of Fusarium proliferatum, having known amounts of FB1, FB2 and moniliformin (FB1 20 microM; FB2 4 microM and moniliformin 7 microM). Inoculum consisted of the respective toxin(s) dissolved in 100 microliters double distilled, autoclaved water (diluent). Control eggs were inoculated with diluent only. Mortality was both dose- and time-responsive in all treatments. Eggs inoculated on day 1 with 1 microM FB1 had 50% mortality; 10 microM FB1 had 70% mortality; 100 microM FB1 had 100% mortality; and CME had 100% mortality. Eggs inoculated on day 10 with 1,10 or 100 microM FB1 or CME had 30, 60, 90 and 80% mortality, respectively. Normal chicks were hatched from all control eggs. The median death times (MDT50) were inversely dose-responsive in all treatments, ranging from 3.0 to 7.4 days in embryos exposed on day 1 and from 3.2 to 9.0 days in those exposed on day 10. Early embryonic changes in exposed embryos included hydrocephalus, enlarged beaks and elongated necks. Pathologic changes were noted in liver, kidneys, heart, lungs, musculoskeletal system, intestines, testes and brain toxin-exposed embryos.

Animals↗
PubMed1993

Dietary monounsaturated fatty acids enhance cholesterol efflux from human fibroblasts. Relation to fluidity, phospholipid fatty acid composition, overall composition, and size of HDL3.

This study was designed to determine whether modifications induced by dietary fats on the high-density lipoprotein3 (HDL3) physicochemical characteristics could affect cholesterol efflux and intracellular cholesterol content, leading to upregulation of low-density lipoprotein (LDL) receptor activity from cultured fibroblasts. Serum HDL3S were obtained from 12 healthy women aged 26 to 49 years who adhered to four 7-week isocaloric diets containing 30% of the caloric intake as fat. Of the total calories, 15.6% of each diet was provided by (1) milk fats, rich in saturated fatty acids; (2) sunflower oil, rich in n-6 polyunsaturated fatty acids; (3) olive oil, rich in monounsaturated fatty acids; and (4) rapeseed oil, rich in n-3 polyunsaturated fatty acids. HDL3 isolated after the monounsaturated fatty acid diet induced the greatest cellular [3H]free cholesterol efflux, reduced the content of intracellular cholesterol, and enhanced 125I-LDL degradation. Univariate regression analyses suggested that the increased capacity of HDL3 to promote cellular [3H]free cholesterol efflux was in part due to its greater fluidity, higher cholesteryl ester content, elevated linoleic to linolenic acid ratio in phospholipids, and its smaller size. In conclusion dietary fats induced physicochemical changes in HDL3, which strongly modulated cellular cholesterol homeostasis in vitro. These data also suggest a novel mechanism by which dietary fats exert their effect on atherosclerosis.

Adult↗
PubMed1993

Analysis of naturally occurring mycotoxins in feedstuffs and food.

Aflatoxins, zearalenone, deoxynivalenol, fumonisins, and their respective metabolites require specific procedures for their determination because of their diverse chemistry and occurrence in complex matrices of feedstuffs and foods. Major sources of error in the analysis of these mycotoxins arise from inadequate sampling and inefficient extraction and cleanup procedures. The determinative step in the assay for each of these toxins is sensitive to levels below those that are considered detrimental to humans and animals. Aflatoxins can be determined in grains and animal fluids and tissues by TLC, HPLC, gas chromatography-mass spectrometry (GC-MS), and ELISA procedures. Zearalenone, an estrogenic mycotoxin, can readily be determined in cereal grains and foods by HPLC (50 ng/g) and by TLC (300 ng/g). No incurred levels of zearalenone or its metabolites have been detected in animal tissues destined for human consumption. Deoxynivalenol can be determined in wheat and corn at 300 ng/g by a rapid TLC procedure and at 325 ng/g by a GC method. Although not tested collaboratively, an HPLC procedure and an ELISA screening procedure are capable of detecting deoxynivalenol at low (nanograms/gram) levels in feedstuffs and foods. The recently characterized fumonisins can be detected by TLC, HPLC, and GC-MS at levels below those now considered harmful. Thin-layer chromatography and HPLC (with fluorescence detection of derivatives) procedures can detect fumonisins at approximately 100 ng/g; GC-MS is required for detection at lower levels.

Aflatoxins↗
PubMed1993

Abdominal body mass distribution and elevated blood pressure are associated with increased risk of death from cardiovascular diseases and cancer in middle-aged men. The results of a 15- to 20-year follow-up in the Paris prospective study I.

The associations of blood pressure (BP), body mass index (BMI) and iliac-to-thigh circumference index (CI) with total, cardiovascular and cancer mortality were investigated in 7312 middle-aged men, initially free of coronary heart disease, known cancer and not treated for hypertension, who have been followed for 15 to 20 years in the Paris prospective study I. Using Cox survival regression analysis, total mortality (1208 deaths) was found to be highest in relatively lean men (BMI < 24.4 kg/m2) with elevated blood pressure (mean BP > or = 96 mmHg) and central pattern of body mass distribution (CI > 1.82). Cancer causes accounted for a large proportion of the increased mortality risk. In parallel, mortality from cardiovascular diseases increased independently with blood pressure and iliac-to-thigh circumference index, but increased with body mass index only in men with low blood pressure (mean BP < 96 mmHg). Taking into account serum cholesterol and cigarette smoking levels as covariates and excluding deaths occurring 5 to 10 years after the examination only slightly attenuated the intensity of this pattern of association.

Abdomen↗
PubMed1992

Aflatoxins in animal and human health.

Aflatoxins remain as a threat to the health of livestock as well as humans by their continuing intermittent occurrence in both feeds and foods. The finding that aflatoxin-contaminated feeds, and eventually purified aflatoxins, were carcinogenic in rats and trout initiated a multitude of studies in search of the role of these toxins in human liver disease, especially cancer. Although aflatoxins have caused acute liver disease in humans, epidemiologic evidence of the involvement of aflatoxins in PLC has not been clarified. Earlier studies did not consider that the hepatitis B virus (HBV) may have contributed to the PLC in the selected populations. Although later studies that did include measurement of the HBV antigen in serum provided conflicting evidence for the role of aflatoxin in PLC in these populations, the latest and most comprehensive study found no association between aflatoxin exposure and PLC mortality. The technological advances and findings of the chemical, immunologic, and metabolic activities of aflatoxins such as binding to DNA and protein to form adducts, development of monoclonal antibodies, and mutational specificity of the genotoxic compounds will, it is hoped, help to clarify the role of aflatoxin as a risk factor, among many others, in the development of primary liver cancer in humans. Aflatoxicosis of animals is usually manifested by pathologic changes in the liver, but they have been found to be carcinogenic and teratogenic as well as causing impaired protein formation, coagulation, weight gains, and immunity. The importance of the carcinogenic effect in livestock is diminished because they are not fed contaminated diets for a sufficient time prior to marketing for slaughter. Animals are variably susceptible to aflatoxins, depending on such factors as age, species, breed, sex, nutrition, and certain stresses. Swine, cattle, and poultry are the domestic species of greatest economic concern in terms of aflatoxicosis. In all species, the evidence of disease is a general unthriftiness and reduction in weight gains, feed efficiency, immunity, and production. More conclusive evidence of aflatoxin involvement in disease includes acute to chronic liver disease with concomitant increases in specific liver enzymes in the serum. In cattle, milk production is affected, but of greater significance is that the aflatoxins in feeds can be rather efficiently converted to toxic metabolites in milk, with even small amounts being readily detectable. The poultry industry probably suffers greater economic loss than any of the livestock industries because of the greater susceptibility of their species to aflatoxins than other species.(ABSTRACT TRUNCATED AT 400 WORDS)

Aflatoxins↗
PubMed1992

Comparison of dietary intakes in four selected European populations.

The composition of diet and food intakes in four selected European populations were compared. Dietary data (from the World Health Organization Project on Monitoring Trends and Determinants in Cardiovascular Disease) were measured by record methods and were available for middle-aged men in Finland (n = 653), France (n = 1128), Northern Ireland (n = 356), and southern Germany (Augsburg region; n = 899). Nutritional variables--which are independent of the absolute energy intake, such as the percentage supply of energy from macronutrients and the ratio of polyunsaturated to saturated fatty acids--were on the whole similar. However, striking differences were found in food intake and in the percentage supply of fat from different foods. The results indicate that detailed knowledge of consumption figures is necessary to develop prudent and acceptable nutrition intervention programs.

Adult↗
PubMed1992

A review and update of animal toxicoses associated with fumonisin-contaminated feeds and production of fumonisins by Fusarium isolates.

During the 1989 corn harvest season, numerous reports of equine leukoencephalomalacia (ELEM) outbreaks and a pulmonary edema (PPE) syndrome in swine from several regions of the United States were received by the National Veterinary Services Laboratories (NVSL), Ames, Iowa. Previous and concurrent research linked Fusarium moniliforme and fumonisin-contaminated feeds to both diseases. Chemical and mycological investigations revealed fumonisin B1 (FB1) concentrations of 20 to 360 ppm in suspect swine feeds and 8 to 117 ppm in suspect equine feeds. Nonproblem feeds contained concentrations below 8 ppm. Fusarium moniliforme and Fusarium proliferatum were isolated from both problem and nonproblem equine and swine feeds. When cultured on autoclaved corn, the F. moniliforme and F. proliferatum isolated produced respective FB1 and fumonisin B2 (FB2) that range from less than 5 to more than 2450 ppm and less than 5 to more than 1000 ppm, respectively. Isolates from both problem and nonproblem feeds produces high levels (greater than 500 ppm) in culture. Reported here is a review of chemical and mycological data resulting from the study of several cases of PPE and ELEM.

Animal Feed↗
PubMed1992

Relationship between smoking and diet: the MONICA-France project.

The association between smoking habits and diet was examined in a sample of 1126 men, aged 45-64 years, from the general population living in the three French MONICA monitoring areas: Bas-Rhin (BR) (n = 346), Haute-Garonne (HG) (n = 400) and Urban Community of Lille (UCL) (n = 380). Diet was assessed by the 3-day record method. The energy and nutrient intakes were calculated for each of the 3 centres, using the same food composition tables. Alcohol consumption was higher among smokers (P less than 0.001). Taking into account alcohol consumption, age, body mass index, centre, educational level and family size, the analyses showed no difference in non-alcoholic energy intake, proteins, carbohydrates, and total fat. However, smokers had a lower intake of polyunsaturated fatty acids (P less than 0.05) and dietary fibre (P less than 0.01) than non-smokers. With regard to food items, smokers had a higher intake of sucrose (P less than 0.05) and a lower intake of vegetables (P less than 0.001), dairy products (P less than 0.05) and cheese (P less than 0.05). These results suggest that analyses in future epidemiological research regarding the role of diet in the aetiology of tobacco-related diseases should consider this association of potential risk factors.

Alcohol Drinking↗
PubMed1992

Fate of Fumonisin B(1) in Naturally Contaminated Corn during Ethanol Fermentation.

Two lots of corn naturally contaminated with fumonisin B(1) (15 and 36 ppm) and a control lot (no fumonisin B(1) detected) were used as substrates for ethanol production in replicate 8.5-liter yeast fermentations. Ethanol yields were 8.8% for both the control and low-fumonisin corn, while the high-fumonisin corn contained less starch and produced 7.2% ethanol. Little degradation of fumonisin occurred during fermentation, and most was recovered in the distillers' grains, thin stillage, and distillers' solubles fractions. No toxin was detected in the distilled alcohol or centrifuge solids. Ethanol fermentation of fumonisin-contaminated corn coupled with effective detoxification of distillers' grains and aqueous stillage is suggested as a practical process strategy for salvaging contaminated corn.

Journal Article↗