摘要:

Polychlorinated biphenyl (PCB) and dichlorodiphenylethane (DDE) methyl sulfone (MSF) metabolites possess high affinities for binding two homologous 16,000 Da homodimeric receptor proteins in the lung (Clara cell secretory protein, CCSP) and the uterus (uteroglobin, UG), leading to selective bioaccumulation of MSFs in these tissues. As marine mammals are highly exposed to organochlorines, concentrations of PCBs, PCB MSFs, DDT, and DDE MSF were analyzed in blubber, lung, and uterus samples from harbor seal (Phoca vitulina) and striped dolphin (Stenella coeruleoalba

ISSN:1528-7394    

DOI:10.1080/00984100050201622

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

The pulmonary toxicity of particles is often studied using a single intratracheal instillation of the material. It was hypothesized that smaller multiple intratracheal administrations of silica would result in differences in pulmonary responses as compared to a single large intratracheal administration. In the first of a series of experiments, the pulmonary responses in male F344 rats to a single intratracheal instillation of crystalline silica (5 mg/100 g body weight) given on d 0 were compared with those resulting from 5 consecutive daily intratracheal administrations of the dust (1 mg/100 g body weight/d) with the initial dose given on d 0. Controls received saline intratracheally. In the second experiment, the dose was reduced to 1 mg/100 g body weight for the single-dose protocol and 0.2 mg/100 g body weight/d for 5 consecutive days for the multiple-dose protocol. In both experiments, responses were assessed on d 14. In the third experiment, the doses were the same as the first experiment, but the responses were assessed on d 28. The indices of toxicity were cellular differentials recovered by bronchoalveolar lavage, which is an index of inflammation, and the level of albumin in the bronchoalveolar lavage fluid, a measure of damage to the capillary-epithelial barrier. At the higher dose of silica, similar levels of inflammation and lung damage were evident in both dosing protocols. Less severe responses occurred at the lower dose. The comparative pattern between the single and multiple dosing protocols was similar in all three experiments. Since only minor differences were noted in the pulmonary responses when the responses to the single- and multiple-dose protocols were compared, data indicate that the multiple-dose protocol does not offer any advantages over the single-dose protocol.

ISSN:1528-7394    

DOI:10.1080/00984100050201631

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

ISSN:1528-7394    

DOI:10.1080/00984100050201640

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

Bipyridylium herbicides produce embryotoxic and teratogenic effects in dipteran, amphibian, avian, and mammalian organisms. Diquat dibromide, a bipyridylium compound, is commonly used as an aquatic herbicide. Mallard (Anas platyrhynchos) eggs were exposed to diquat by immersing the eggs for 10 s in solutions of 0.88, 3.5, 7, 14, or 56 g/L on either d 4 or 21 of incubation. Application of diquat on d 4 yielded an estimated LC50 of 19.5 g/L through 18 d of incubation, and 9.6 g/L through hatching. Body and organ weights, and bone lengths of hatchlings did not differ between control and treatment groups with the exception of a slight increase in brain weight in the 14 g/L group. Malformations in diquat-treated embryos included defects of the brain, eye, bill, limb, and pelvis; skeletal scoliosis; and incomplete ossification. Subcutaneous edema was also present. Significant manifestations of oxidative stress were apparent in hatchlings and included increased hepatic thiobarbituric acid-reactive substances (TBARS) (lipid peroxidation) and decreased brain reduced glutathione (GSH). Brain protein-bound sulfhydryls (PBSH) increased. Diquat applied on d 21 of incubation yielded an estimated LC50 of 12.6 g/L through hatching. Exposure at this late stage of development did not produce deformities. Body and organ weights and, bone lengths of hatchlings did not differ between control and treatment groups. Significant manifestations of oxidative stress in hatchlings included decreased brain GSH, increased oxidized glutathione (GSSG), and ratio of GSSG to GSH. This study suggests that concentrations of diquat commonly used for aquatic weed control, when based upon the dilution effect of average water depth of the application area, would probably have little impact on mallard embryos. However, concentrations applied above ground to weeds and cattails along ditches could adversely affect the survival and development of mallard embryos, and presumably other avian species nesting in such habitats.

ISSN:1528-7394    

DOI:10.1080/00984100050201659

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

The aim of this study was to investigate the effects of cadmium-induced peroxidative damage to rat adrenals. Cadmium significantly increased adrenal lipid peroxidation in a dose- and time-related manner. Cadmium-induced lipid peroxidation was accompanied by a marked elevation in adrenal iron (Fe) levels, in particular the free elemental form. Chelation of Fe with deferoxamine decreased the cadmium effect on lipid peroxidation. Selenium (Se) was also effective in inhibiting Cd-induced adrenal lipid peroxidation. Data indicate that Cd-induced lipid peroxidation in rat adrenals may be dependent upon Fe and Se levels in this tissue.

ISSN:1528-7394    

DOI:10.1080/00984100050201668

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

The Kozi Brod (left tributary of the Biala Przemsza, east of Katowice) flows in a highly industrial coal-mining area dominated by the power plant of Siersza. Concentrations of the microelements nickel (Ni), chromium (Cr), cobalt (Co), zinc (Zn), manganese (Mn), lead (Pb), cadmium (Cd), copper (Cu), barium (Ba), aluminum (Al), vanadium (V), and strontium (Sr), as well as the macronutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and sulfur (S), were measured in water and plants of the Kozi Brod. The collected plants were:Myosotis palustrisL. Nathorst,Galium palustreL.,Mentha rotundifoliaL. Huds.,Mentha aquaticaL.,Berula erecta(Huds.) Coville,Cardamine amaraL.,Epilobium angustifoliumL.,Geranium palustreL.,Lysimachia vulgarisL.,Crepis paludosaL. Much.,Calitriche vernaL.,Solanum dulcamaraL., and the aquatic mossHygrohypnum ochraceum(Turn.) Loesk. These plants were used to evaluate the spatial distribution of elements in the Kozi Brod and contained elevated levels of Co, Cd, Zn, Ni, Mn, Al, Pb, and Cu. Significant correlations between concentrations of Cd, Zn, and Mn in water and plants indicate the potential of these species for pollution monitoring.

ISSN:1528-7394    

DOI:10.1080/00984100050201677

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor