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Biomedical subjects

E D Barber

Publications and source records attributed to E D Barber.

23 records · Page 2Linked to original sources
PubMedDate not supplied

Results of the L5178Y mouse lymphoma assay and the Balb/3t3 cell in vitro transformation assay for eight phthalate esters.

Eight phthalate esters, with alcohol chain lengths of 1-11 carbon atoms and with various degrees of branching, were tested in vitro in the L5178Y mouse lymphoma mammalian cell mutation assay and in the Balb/3T3 cell transformation assay. The tests were performed as part of a voluntary testing agreement between the Chemical Manufacturers Association's Phthalate Esters Panel and the United States Environmental Protection Agency (US EPA). The esters tested were: dimethyl phthalate (DMP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), di-¿n-hexyl, n-octyl, n-decyl¿ phthalate (610P), di-isononyl phthalate (DINP), di-¿heptyl, nonyl, undecyl¿ phthalate (711P), di-isodecyl phthalate (DIDP) and di-undecyl phthalate (DUP). Both DMP and DBP were found to produce significant increases in the mutant frequency in the mouse lymphoma assay in the presence but not in the absence of an Aroclor-induced rat liver activation system (S-9). Ester 610P gave equivocal results in the mouse lymphoma assay in the presence and absence of rat liver S-9. There was no indication of mutagenic potential for any of the other test materials in the mouse lymphoma assay, and none of the test materials increased transformation frequency in the Balb/3T3 cell transformation assay. Aldehyde metabolites of the de-esterified alcohols are postulated to play a role in the positive results for DMP and DBP.

3T3 Cells↗
PubMedDate not supplied

Hydroquinone: genotoxicity and prevention of genotoxicity following ingestion.

Plant-derived polyphenolics and other chemicals with antioxidant properties have been reported to inhibit the expression of genotoxic activity by pro-oxidant chemicals (Sai et al., 1992, 1994; Teel and Castonguay, 1992). In vitro and in vivo studies with ionizing radiation suggest that hydroquinone (HQ) may have similar protective effects (Babaev et al., 1994). The present study was conducted to determine whether HQ is capable of inhibiting the induction of micronuclei in the bone marrow of mice following exposure to an oxidant, potassium bromate or KBrO3 (Nakajima et al., 1989; Sai et al., 1992, 1994). To be able to interpret the results of this work, it was also necessary to determine whether HQ is itself genotoxic when fed in the diet. HQ diets (0.8%) fed to mice for 6 days reduced the background incidence of micronuclei compared with the basal diet. KBrO3 dosed ip (12.5-100 mg/kg) produced a dose-dependent increase in micronuclei as reported by others. Mice fed 0.8% HQ diets 6 days, and then dosed intraperitoneally with KBrO3, showed a 36% reduction in micronuclei across the range of KBrO3 dose levels. This effect was associated with a reduction in the background micronucleus response as well as a reduction in response to KBrO3. Statistical significance (P < or = 0.05), observed at a dose of 25 mg/kg KBrO3 in the mice fed the control diet, was abolished in the group fed 0.8% HQ. When mice were given 50 mg HQ/kg by oral gavage and then given 50 mg KBrO3/kg ip 20 min later, the micronucleus response induced by KBrO3, was lower in animals given HQ. The results of this study demonstrate that large doses of HQ may be given orally without induction of micronuclei or bone marrow depression, that HQ reduces the background micronucleus response in animals fed a basal diet, and that the HQ reduces the micronucleus response to KBrO3 as well as background incidence of micronuclei in KBrO3-dosed animals. The protective effect of HQ may be due to enzyme induction or a direct antioxidant effect of HQ against oxidants commonly present in the diet.

Administration, Oral↗
PubMedDate not supplied

Unit orientation for experienced nurses. Process and evaluation.

In order to recruit and retain registered nurses during an era of nursing shortages, staff development educators must provide orientation programs that are highly satisfactory. This article describes a program that effectively links the perspectives of nurse managers, nursing staff, and nurse educators. Orientation evaluation questionnaires completed by orientees and staff nurses who served as their buddies show that new employees believe this program meets their learning needs. Such satisfied nurses can recruit their colleagues to employment.

Attitude of Health Personnel↗