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Biomedical subjects

W E Field

Publications and source records attributed to W E Field.

At least 19 recordsLinked to original sources
PubMed1992

Toxicity studies of Caramel Colour III and 2-acetyl-4(5)-tetrahydroxybutylimidazole in F344 rats.

Caramel Colour III is used as a colour additive in beers and a variety of foods. Beer is the most important single source of Caramel Colour III in the diet although consumption of dark beers has been decreasing in recent years. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an acceptable daily intake of 200 mg/kg/day for Caramel Colour III. The safety of Caramel Colour III has been questioned during recent years following feeding studies in the rat that were associated with reduced white cell and lymphocyte counts. These effects have been attributed to the presence of 2-acetyl-4(5)-tetrahydroxybutylimidazole (THI) in this class of caramel colour. Short-term oral toxicity studies were conducted on low-THI and high-THI samples of Caramel Colour III (13 wk) and on a sample of THI (28 days). In both studies, the test materials were mixed with demineralized water and the solutions were given to the animals ad lib. in the drinking fluid. In the 13-wk subchronic toxicity study of Caramel Colour III, groups of 20 rats/sex were given concentrations of caramel colour equivalent to intakes of 0, 10, 15 or 20 g low-THI caramel colour/kg body weight/day or 20 g/kg of a high-THI caramel colour. In the 4-wk toxicity study with THI, groups of 20 rats/sex were given 0, 8 or 64 ppm THI (equivalent to approx. 0, 0.9 or 7.2 mg/kg/day) and 10 rats/sex were given 1, 2, 4, 16 or 32 ppm THI (equivalent to approx. 0.1, 0.2, 0.5, 1.9 or 3.7 mg/kg/day) for 4 wk followed by a 2-wk recovery phase for 10 rats/sex in the 0, 8 and 64 ppm groups. Rats given Caramel Colour III had soft faeces; there were no other treatment-related clinical observations and no treatment-related deaths occurred. All treated groups given Caramel Colour III had lower food and fluid consumption than controls. Males given 15 or 20 g low-THI caramel colour/kg or 20 g high-THI caramel colour/kg and females given 20 g/kg of either type had lower body weights than controls. In the 4-wk toxicity study with THI, there were no treatment-related ante-mortem observations, and no effects on body weights or food consumption. Fluid consumption by males and females treated with 64 ppm THI was lower than that of controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1992

Toxicity and carcinogenicity studies of Caramel Colour IV in F344 rats and B6C3F1 mice.

Caramel Colour IV, a type of caramel colour used in the manufacture of cola soft drinks, was evaluated for subchronic and chronic toxicity in rats, and carcinogenicity in Fischer-344 (F344) rats and B6C3F1 mice. In each of the studies, Caramel Colour IV was mixed with demineralized water and the solutions given to the animals ad lib. in the drinking fluid. The concentrations of Caramel Colour IV in the drinking fluid were adjusted periodically to achieve the desired caramel colour intake per kg body weight. In the range-finding studies, groups of 30 rats/sex were given Caramel Colour IV at levels of 0, 15, 20, 25 or 30 g/kg for 13 wk, and groups of 10 male rats were given levels of 0, 2.5, 5, 10 or 15 g/kg for 6 wk followed, for some dose groups, by a 2-wk withdrawal period, and then re-initiation of dosing for another 2 wk. In the rat chronic toxicity study, levels of Caramel Colour IV of 0, 2.5, 5, 7.5 or 10 g/kg were given to groups of 25 rats/sex for 12 months. The test groups in the rat and mouse carcinogenicity studies were composed of 50 animals/sex and each species was given the caramel colour at levels of 0, 0, 2.5, 5 or 10 g/kg for 24 months. In each of the studies, treated animals tended to have dose-related lower water consumption than controls. This was attributed to poor palatability of the drinking fluid, and was generally associated with decreased food consumption and body weights. Rats given caramel colour often had soft or liquid malodorous faeces although there were no treatment-related ante-mortem observations in mice. Blood biochemical changes in the rat (i.e. reduced blood urea nitrogen, alkaline phosphatase and total serum protein) appeared to be related to dietary influences and were not considered toxicologically significant. There were no treatment-related alterations in haematological variables or treatment-related differences in survival or in the incidence of benign or malignant tumours among treated and control groups and no toxicologically important pathological findings. On the basis of these studies, Caramel Colour IV was not toxic or carcinogenic in F344 rats or B6C3F1 mice. The highest dose level tested in the long-term studies (10 g/kg) was considered to be the no-observed-adverse-effect level (NOAEL).

Administration, Oral↗
PubMed1990

Scope and magnitude of injuries in the agricultural workplace.

Agricultural work injury data are less available than data for other industries, so an overview of existing data is provided. Agriculture has the highest annual work death rate of all industries, 52 per 100,000 workers, which is five times the combined rate for all industries. Tractor-related injuries are the leading types of fatal injuries; injuries involving agricultural machinery, animals, and trucks are the leading types of non-fatal injuries. Victims of fatal accidents range in age from less than 1 year to over 90. Research needs are discussed, including the need for comprehensive surveillance.

Accidents, Occupational↗
PubMed1988

The effect of selected arachidonic acid metabolites on natural killer cell activity.

The effect of arachidonic acid (AA) metabolites of lipoxygenase(s) was evaluated on natural killer (NK) cell activity in Fischer F344 rat splenic lymphocytes and compared with prostaglandin E2 (PGE2), a known inhibitor of NK cell lytic activity. It was observed that 5(S),12(S)-dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid (5(S),12(S)-diHETE, EZEZ) inhibited NK cell activity to a degree comparable to the inhibitory effects of PGE2. This compound maximally inhibited NK cell activity at concentrations of 10(-6) and 10(-8) M. PGE2 and 5(S),12(S)-diHETE (EZEZ) inhibited NK activity to an identical degree at all concentrations and effector:target (E:T) cell ratios tested. Of the other lipoxygenase pathway metabolites screened, 8(S),15(S)-all trans-diHETE and 8(S),15(S)-diHETE (EZEZ) also inhibited NK activity, but only at 10(-6) M and a 50:1 E:T cell ratio. These findings provide further evidence that the lipoxygenase and cyclooxygenase pathways produce metabolites which can modulate NK cell function, and that 5(S),12(S)-diHETE (EZEZ), which has not been previously tested for effects on NK cells, may have a significant immunoregulatory role.

Analysis of Variance↗
PubMed1985

Hearing voices.

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Adaptation, Psychological↗
PubMed1984

Clinical competencies of baccalaureate students.

Clinical Competencies of new graduates from baccalaureate programs have periodically been criticized by employers of new graduates. In an effort to understand the levels of clinical preparation for new baccalaureate graduates, three hypotheses dealing with the cognitive, affective, and psychomotor domains were tested. A review of the literature reveals that most exploration and work has been done relative to the cognitive domain. Sixty-four NLN accredited baccalaureate programs responded to a request that they provide all of the clinical objectives used in their program. Findings revealed that there were clinical evaluation criteria written at all levels of the three domains; however, most schools did not have objectives at each of the levels of the three domains. A disproportionately large number of clinical objectives are written at the cognitive domain. The study raises the question as to the abilities of students to be clinically proficient upon graduation when there are relatively few evaluation criteria written in the psychomotor domain.

Affect↗
PubMed1981

Preclinical toxicologic studies of netilmicin.

1-N-Ethylsisomicin (netilmicin), a semisynthetic aminoglycoside antibiotic, was given parenterally to mice, rats, guinea pigs, rabbits, and dogs for toxicological evaluation. Acute signs of toxicity were consistent with neuromuscular blockade. Results of teratological studies in rats and rabbits were negative; the only effect observed was wavy ribs, a minor developmental variation, in rats. No effects were found on fertility, reproduction, or development of offspring. Single daily doses of 60 mg/kg s.c. for 10 weeks in young rats and 30 days in young dogs were non-toxic. No indication of toxicity was found in rats and dogs given single daily doses of 7.5 mg/kg i.v. for 2 weeks. Daily i.m. doses caused signs of neuromuscular blockade in rats after 2 weeks at 100 mg/kg and after 1 month at 50 mg/kg, and in dogs after 2 months at 75 mg/kg; dose levels of 150 mg/kg did not cause renal failure. No ocular changes or impairment of vestibular or auditory function were evident at any dose studied. Comparison with tobramycin, gentamicin, and kanamycin at s.c. doses of 50 or 150 mg/kg per day for 4 weeks showed netilmicin to be less nephrotoxic in rats than tobramycin or gentamicin and only slightly more nephrotoxic than kanamycin. Only mild changes were seen microscopically in kidneys of dogs given netilmicin at daily doses of 75 mg/kg i.m. for 3 months. The renal effects of netilmicin given at high multiples of the human therapeutic dose were one-half to one-third less that those of gentamicin and were not severe at any dosage.

Abnormalities, Drug-Induced↗
PubMed1975

Cataracts in beagle dogs given diazoxide.

In two studies for toxicity, cataracts occurred in beagle dogs given diazoxide daily in high doses. Two of eighteen dogs given diazoxide intravenously at doses of 30.0 mg. per kilogram twice a day for fourteen days had reversible lenticular changes. These changes were not observed in dogs given 22.5 or 10.0 mg. per kilogram twice a day. By fifty-eight days after the last treatment, the cataracts had regressed or disappeared completely. In a study of diazoxide given orally for a maximum of seventy-eight weeks, cataracts developed in six of forty-two dogs given doses ranging from 50 to 200 mg. per kilogram daily, but none occurred in dogs receiving 15 or 30 mg. per kilogram daily. Hyperglycemia was observed at doses of 50 mg. per kilogram or higher. In five of the six dogs that had cataracts and hyperglycemia, vacuolation or absence of islet cells was seen on histologic examination of pancreatic tissue at necropsy. Ocular changes were attributed to the hyperglycemic effect of high doses of diazoxide given daily for prolonged periods. The daily doses given dogs in which cataracts developed were from ten to forty times that suggested in man (5 mg./kg.).

Administration, Oral↗