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Results 451 - 500 of 594
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Salazar M - - 1998
The purpose of this study was to evaluate the toxicity of Spirulina maxima, a blue-green alga used as food supplement and food coloring, after 13 weeks of treatment. Groups of ten mice of each sex were given S. maxima in the diet at concentrations of 0 (control), 10, 20 or ...
Randall D J - - 1998
Uptake of persistent lipophilic toxicants in fish occurs via the food and by transfer across the body surface, notably the gills. Flux rates of most lipid soluble toxicants across the gills is rapid and the animal must eat at very high rates for feeding to have a significant effect on ...
Mandal B K - - 1998
The groundwater in seven districts of West Bengal, India, covering an area of 37,000 km2 with a population of 34 million, has been contaminated with arsenic. In 830 villages/wards more than 1.5 million people, out of the total population, drink the arsenic-contaminated water. Safe water from a source having < ...
Miller A L - - 1998
Heavy metals are, unfortunately, present in the air, water, and food supply. Cases of severe acute lead, mercury, arsenic, and cadmium poisoning are rare; however, when they do occur an effective, non-toxic treatment is essential. In addition, chronic, low-level exposure to lead in the soil and in residues of lead-based ...
Komori Y - - 1998
Biological activities in Vipera a. aspis and V. a. zinnikeri venom were investigated and compared. Phospholipase A2 and lethal activities were found to be much higher in V. a. zinnikeri venom; the LD50 values for V. a. aspis and V. a. zinnikeri crude venom were 0.55 and 0.35 microgram/g, while ...
Galer D M - - 1998
The tissue residues of veterinary drugs given to food-producing animals are an ill-defined mosaic of parent drug and metabolites. Consumers are only ever exposed to this mixture in the presence of a vast excess of the excipient, food. Given the modifying effects of food on the absorption and disposition of ...
Aphale A A - - 1998
Ginseng (Panax ginseng) and Ashwagandha (Withania somnifera) are widely used as geriatric tonics. Both individually have not shown any toxicity on long term administration. Study was planned to assess the safety of the combination by doing subacute toxicity study in rats with 90 days oral administration using three doses. Food ...
Fernandez Leborans G - - 1998
The toxicity and bioaccumulation of lead has been studied using marine protozoa communities developed in laboratory microecosystems. The concentrations tested were 500 and 1000 micrograms.L-1 of lead as lead acetate. The protozoan was able to bioaccumulate 27.02-504 micrograms Pb.g-1 dry weight. Bacteria also bioaccumulated lead, but always to a lesser ...
WILDISH, David
The effects of toxic and non-toxic strains of Alexandrium sp. on the initial feeding responses of the Pacific oyster Crassostrea gigas were determined by continuous monitoring of the clearance rate of individual oysters. This was determined fluorometrically by loss of fluorescence of live microalgae introduced as food. Feeding oysters with ...
Gebel T W - - 1998
Part of the northern Palatinate region in Germany is characterized by elevated levels of arsenic and antimony in the soil due to the presence of ore sources and former mining activities. In a biomonitoring study, 218 residents were investigated for a putative increased intake of these elements. Seventy-six nonexposed subjects ...
MacIntosh D L - - 1997
Inorganic arsenic intake in 969 men and women and methylmercury intake in 785 men and women from across the United States were assessed by a semiquantitative food frequency questionnaire, in combination with a database for the content of those elements in foods, and by toenail concentrations of arsenic and mercury. ...
Hamilton S J - - 1997
Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios ...
van Elteren J T - - 1997
A novel separation for cationic arsenic compounds on a polymer-based cation-exchange column was developed using an ion-pairing reagent (3-carboxy-4-hydroxybenzenesulphonic acid) in the mobile phase. An existing anion-exchange separation was used for anionic arsenic compounds. Combining both separation techniques, eight environmentally important arsenic compounds can be determined using on-line decomposition in ...
Hellwig J - - 1997
In a two-generation reproduction toxicity study, groups of 25 male and 25 female Wistar rats (for both F0 and F1 generations) received acrylic acid (AA) in the drinking water at concentrations of 0 (control), 500, 2500 and 5000 ppm for at least 70 days prior to mating, through mating, gestation, ...
Kungsuwan A - - 1997
Screening tests were carried out on the toxicity of freshwater puffers Tetraodon leiurus complex and Tetraodon suvatii collected from Udonthani province, north-eastern Thailand. Toxicity was highest in the liver and varied according to the location and season of fish catch. Fish which were reared in tap water for 3 months ...
Biggs M L - - 1997
The purpose of this study was to investigate methods for ascertaining arsenic exposure for use in biomarker studies. Urinary arsenic concentration is considered a good measure of recent arsenic exposure and is commonly used to monitor exposure in environmental and occupational settings. However, measurements reflect exposure only in the last ...
Eteng M U - - 1997
Caffeine and theobromine are purine alkaloids widely consumed as stimulants and snacks in coffee and cocoa based foods and most often as part of ingredients in drugs. Man has enjoyed a long history of consumption of caffeine and theobromine. Recent interest in these two alkaloids, however, is centered on their ...
Sapunar-Postruznik J - - 1996
Total amounts of arsenic in foods sold in Croatia were determined over a 5-year period (1988-1993). Highest mean levels were recorded in the following food groups: fish (498 micrograms/kg), fishery products (270 micrograms/kg) and cheese and dairy products (39 micrograms/kg); lowest levels were contained in fruit, chocolate and fruit products ...
Uthus E O - - 1996
Circumstantial evidence suggests that aluminum, arsenic, bromine, cadmium, germanium, lead, lithium, nickel, rubidium, silicon, tin and vanadium are essential. The evidence is most compelling for arsenic, nickel, silicon and vanadium. The estimated daily dietary intakes for these elements are arsenic, 12-50 micrograms; nickel, 100 micrograms; silicon, 20-50 mg and vanadium, ...
Hopenhayn-Rich C - - 1996
Methylation is considered the detoxification pathway for inorganic arsenic (InAs), an established human carcinogen. Urinary speciation analysis is used to assess the distribution of metabolites [monomethylarsonate (MMA), dimethylarsinate (DMA), and unmethylated arsenic (InAs)], as indicators of methylation capacity. We conducted a large biomarker study in northern Chile of a population ...
Careri M - - 1996
This paper reviews applications of different LC-MS techniques for the determination of xenobiotic substances in foods. Specific examples of contaminants discussed are pesticides, herbicides, insecticides and drugs; concerning toxic substances, mycotoxins, phycotoxins, cyanobacterial toxins, mutagenic and heterocyclic amines and beta-carbolines, arsenic, tin and inorganic halogen compounds, packaging materials and various ...
Barry M J - - 1995
The effects of algal concentration (Selanastrum capricornatum) on the toxicity of the organochlorine pesticide endosulfan and the synthetic pyrethroid esfenvalerate to Daphnia carinata was investigated. The study progressed through four stages: (1) A dose-response experiment on the effects of endosulfan and esfenvalerate on the survival, growth, and reproduction of D. ...
Zaroogian G - - 1995
Toxicities of binary mixtures of Cu2+, Cd2+, benzo(a)pyrene [B(a)P] and N-ethylmaleimide (NEM) were screened using the in vitro neutral red (NR) assay to test the hypothesis that combined toxicity is more than or less than additive relative to the influence of each mixture constituent on toxicant uptake and brown cell ...
Iverson F - - 1995
Synthetic phenolic antioxidants have been added to foods for decades to retard the autooxidation of lipid that leads to rancidity. The major antioxidants, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), are used in foods world wide. Recent studies suggest that BHA, and perhaps BHT, are carcinogenic to rodents. International efforts, ...
Nagayama J - - 1995
We have been already contaminated with various chemicals including highly toxic organochlorine compounds such as 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), 2, 3, 4, 7, 8-pentachlorodibenzofuran (PenCDF) and 3, 4, 5, 3', 4'-pentachlorobiphenyl (Co-PenCB). In this study, in order to evaluate the genotoxicity of the three chemicals, we have examined their ...
Krogh P H - - 1995
The reproduction of two closely related soil microarthropods, Folsomia candida Willem and Folsomia fimetaria L. (Insecta: Collembola), was tested under the influence of the insecticide dimethoate. Dimethoate had an adverse effect on the survival of adults and their reproduction in concentrations of about the recommended field dose, with F. fimetaria ...
Hamilton S J - - 1995
Acute toxicity tests were conducted with three life stages of Colorado squawfish (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and bonytail (Gila elegans) in a reconstituted water quality simulating the middle part of the Green River of Utah. Tests were conducted with boron, lithium, selenate, selenite, uranium, vanadium, and zinc. The ...
Yang R S - - 1995
Methyl bromide is widely used as an insecticidal fumigant in food supplies, warehouses, barges, buildings, and furniture. Its popularity as a fumigant is largely attributable to its high toxicity to many pests, the variety of settings in which it can be applied, its ability to penetrate the fumigated substances, and ...
Rabovsky J - - 1995
Biogenic amorphous silica (BAS) is a natural constituent of living matter (eg, unicellular organisms and crop plants). Diatoms, whose siliceous remains are the geologic precursors to diatomaceous earth, actively process soluble silica into BAS. In some plants, a portion of the BAS exists externally as pointed or irregularly shaped fibers. ...
Spoerke D - - 1994
Even though it comes from a potentially toxic family and may contain solanine-type alkaloids, the potato has risen from a wild food stuff of South American Indians to one of the world's most useful plants and important food source. Toxicity of the tuber commonly seen today is low, with the ...
Fargasová A - - 1994
The toxicity of Hg2+ [HgCl2], Cr6+(1) [(NH4)2CrO4], Cr6+(2) [CrO3], Cd2+ [CdCl2.2,5H2O], Pb2+ [Pb(CH3COO)2.3H2O], and As5+ [Na2HAsO4.7H2O] on the sensitivity and survival of Daphnia magna and Tubifex tubifex has been studied. All test metals were dissolved and determined under standardized conditions (dilution water, Bringmann and Kühn, 1982) and 96 hr LC50 ...
Adebajo L O - - 1994
Chicken embryo bioassay was used to monitor the toxicity of extracts from rootstock snack samples during a 210-day storage period. Results show that the relative toxicity values which were initially very low increased significantly as from 120th day (when 32% mortality was recorded) up till the last day when 73% ...
Komala Z - - 1994
The toxicity level of heterocyclic compound fractions obtained from dust in Silesia for Paramecium primaurelia was studied. For the estimation of their toxicity a special scale elaborated for this material was used. It was found that the level of toxicity of investigated fractions differed, depending on the sampling place and ...
Vetter J - - 1994
The arsenic and cadmium contents of 88 samples of mushrooms were determined. The majority of samples have a very low (practically zero) arsenic level; however, significant accumulations were found in the Agaricus species and in Macrolepiota rhacodes (which is related to the Agaricaceae family) and in three Tricholomataceae species (Flammulina ...
Iverson F - - 1994
Marine and terrestrial food sources are susceptible to contamination by various industrial chemicals and microbial pathogens. Both types of hazard are amenable to regulatory assessment using a single toxicology data base, along with some knowledge of contaminant levels and consumption figures for food. On the other hand, regulatory problems persist ...
Moore D - - 1993
Thallium is a heavy metal whose salts are used in some rodent poisons and in the manufacture of optical lenses, semiconductors, scintillation counters, low temperature thermometers, and switching devices, green coloured fireworks, and imitation jewelery, and as chemical catalysts. In clinical practice thallium isotopes are used in cardiac scanning, but ...
Amonoo-Neizer E H - - 1993
The total arsenic content of some Ghana food and cash crops from Kumasi and Obuasi farms and markets was determined. Quantitative analysis of arsenic was also conducted on vegetation, cooked food obtained from some homes, local fish, and meat, as well as some soil and water samples. In all, 266 ...
Naylor C - - 1993
The continuous culture of fresh green algae for use as food for Daphnia magna in toxicity tests is labor intensive. The possibility of using freeze-dried Chlorella vulgaris as an off-the-shelf food was investigated. The performance of D. magna provided with freeze-dried food was investigated over several generations and was found ...
Schuytema G S - - 1993
Sub-adult African clawed frogs (Xenopus laevis) were fed pentachlorophenol (PCP)-injected mealworms containing 64.8 to 2604 ug of PCP per gram of worm for 27 days. There was no mortality and no significant bioaccumulation of PCP in the frogs. After three weeks, frogs fed 2,604 micrograms/g of PCP ceased eating. The ...
Clayson D B - - 1993
Those chemicals that are added to food during modern processing are most stringently examined for toxic effects and, if they demonstrate toxicity, are strictly controlled. Despite this, a considerable proportion of the North American human cancer burden has been associated with diet and nutrition. The possible contributions of excess calories, ...
Munger L L - - 1993
Coumafuryl (Fumarin) toxicity was diagnosed in chickens less than 1 week of age. Mortality rate was 100%. Necropsy showed crops and gizzards to be full of feed. There was diffuse hemorrhage and unclotted blood in the abdomen and thorax. Histological examination showed congestion and hemorrhage. Chemical analysis of crop and ...
Gorbi G - - 1993
The effects of feeding Daphnia magna on algae (Scenedesmus acutus) pretreated with different concentrations of Cr(VI) were studied. A positive effect on growth and newborn production rate was observed in the daphnids fed on algae exposed to 1 mg/liter Cr(VI). Fecundity and growth were drastically reduced in daphnids fed on ...
Dabeka R W - - 1993
During a comprehensive total diet study extending from 1985 to 1988, foods were collected in 6 Canadian cities (in one of them, a pilot study was conducted twice). For each of the 7 collections, foods were processed into 112 composites (105 in the initial pilot trial). Total arsenic was determined ...
Del Razo L M - - 1993
This paper reports on the concentrations and geographical relationships between fluoride and total arsenic in 129 water wells of the Región Lagunera, Mexico, where arsenic has caused severe health effects. Fluoride concentrations ranged from less than 0.5 to 3.7 mg liter(-1); 25 samples (19.4%) had levels above 1.5mg liter(-1), the ...
Stoltz J H - - 1992
Psittacine birds can develop severe and often fatal pneumonitis when exposed to various noxious inhalants. Toxicosis in these birds caused by inhalation of pyrolysis products produced from overheated polytetrafluoroethylene-coated cooking pans on stove tops is well known, but compounds emitted from burned foods and other materials can also be toxic. ...
Nygren O - - 1992
CCA-impregnated timber contains copper, chromium and arsenic (CCA), and occupational exposure to wood dust as well as the CCA compounds may occur in work with such timber. Dust from commercially available impregnated wood has been found to contain hexavalent chromium, which is regarded as a carcinogen. Apart from determinations of ...
Stone L - - 1992
Aquatic ecosystems offer striking examples of how positive feedback can be integral to the dynamics of complex communities. In particular, microorganisms (bacteria and protozoa) introduce a multitude of positive feedback pathways by rapidly recycling nutrients at the very base of many aquatic food webs. The relatively large magnitude of fluxes ...
Bennett D C - - 1992
Sodium toxicity was suspected in hand-reared great blue heron (Ardea herodias) chicks fed herring frozen in brine (seawater). Affected chicks were lethargic with stiff legs that extended to the posterior, and breathing was labored. Chicks regurgitated food or refused to eat. All chicks that were fed herring exclusively and eight ...
Aldeen W E - - 1992
In a blind comparison, 465 randomly collected clinical fecal specimens were examined. Hemo-De was found to be an excellent replacement for ethyl acetate in the concentration procedure and for carbol-xylene and xylene in the trichrome staining procedure. Elimination of toxic reagents, combined with its lower cost, makes Hemo-De the preferred ...
Aregheore E M - - 1992
A review of the toxicity factors in some food and feedingstuffs in the nutrition of man and livestock in Nigeria was conducted. The crops reviewed were cassava, cocoyam, guinea corn, cottonseed, soyabean, bambara, groundnut and cowpea. These crops provide cheap sources of carbohydrate and protein in the diets of humans ...
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