摘要:

A single dose of 2,3,7,8‐TCDD (1 μg/kg,i.p. injection) resulted in a significant decrease in cellular 3‐O‐methyl‐[3H]‐glucose uptake by guinea pig adipose tissue and pancreas after 24 hours. Anin situtissue culture study in which pieces of adipose tissue were incubated with 10‐8M TCDD showed a time‐dependent decrease in glucose uptake. Reconstitution of adipocyte plasma membrane from tested or control animals into artificial liposomes also resulted in this difference in glucose uptake. Binding of [3H]‐cytochalasin B, a specific inhibitor of glucose transporter proteins, was significantly lower in acetone‐ether powder preparations of TCDD‐treated adipose tissue than from controls, suggesting that the total titer of these proteins is decreased by TCDD. Finally, the relevance of these results to glucose or lipid metabolism was tested. Lipoprotein lipase (LPL) activity of guinea pig adipose tissue was decreased after 8 hours ofin situincubation with TCDD indicating that glucose uptake was depressed at an earlier time point. These findings may contribute to a better understanding of dioxin‐induced “wasting syndrome.”

ISSN:0360-1234    

DOI:10.1080/03601239209372797

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Comparative toxicity of several pesticides, lindane, endosulfan, pentachlorophenol (PCP), 3,4‐dichloroaniline (DCA) and copper sulphate has been tested to determine their lethality in two species of freshwater invertebrates,Daphnia magnaandBrachionus calyciflorus. D. magnawas more sensitive thanB. calyciflorusto all the toxicants tested except to copper sulphate. DCA was the most toxic compound toD. magnaand was followed in order of decreasing toxicity by copper sulphate, PCP, endosulfan and lindane. Copper sulphate was the most toxic chemical tested to the rotiferB. calyciflorusand was followed by PCP, endosulfan, lindane and DCA. The 24 hr LC50 values (mg/L) forD. magnaandB. calyciflorus,respectively, were: lindane, 1.64 and 22.5; endosulfan, 0.62 and 5.15; DCA, 0.20 and 61.5; PCP, 0.39 and 2.16; copper sulphate, 0.38 and 0.076.

ISSN:0360-1234    

DOI:10.1080/03601239209372798

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An indirect enzyme‐linked immunosorbent assay (EIA) for metolachlor (2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐l‐methylethyl)acetamide) detection in river water and soil was developed using serum obtained from rabbits immunized against the acid of metalaxyl ((N‐(2,6‐dimethylphenyl)‐N‐(methoxy‐acetyl)‐DL‐alanine methyl ester) conjugated to bovine serum albumin. The assay had a linear working range from 1 to 50 ng/ml with a mean IJ0value of 13.6 ng/ml and a lower detection limit of 2.0 ng/ml. Both the mean interwell and interassay coefficients of variation were less than 4% over the range of the standard curves for samples which had been prepared in phosphate buffered saline (PBS), river water, or soil extract. Assay cross‐reactivity to the following four structurally related chloro‐acetanilide pesticides were: propachlor (0%), metazachlor (0%), alachlor (23%), and metalaxyl (5,000%). Mean recoveries of metolachlor in spiked (2.0 to 32.0 ng/ml range) PBS, river water, and soil extract were 102%, 103%, and 110%, respectively. Soil samples were taken over a 56‐d period from field plots treated with metolachlor and analyzed by GC and EIA. The correlation coefficient for comparison of the two methods was 0.96 with the slope of the linear regression line being 0.78. Furthermore, no statistical difference (P<0.05) was found between the dissipation curves of metolachlor derived from GC data versus EIA data.

ISSN:0360-1234    

DOI:10.1080/03601239209372799

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This study was conducted to determine the degradation rates in turfgrass soil over a 12‐month period after a single field application of propoxur and to isolate microorganisms from the soil capable of degrading the insecticide. Soil samples were collected from a turfgrass experimental site near Fort Lauderdale, FL one week before the field application of propoxur, and over a 12‐month period after the field application. Mineralization rates in surface (0 ‐ 15 cm depth) and subsurface (15 ‐ 30 cm depth) soil samples collected before the field application were low. Mineralization in surface and subsurface samples collected 1, 6 and 8 months after the field application was much higher than for corresponding samples collected before the field application. Mineralization in the subsurface samples collected 12 months after the field application had reverted back to the similar rate for the corresponding sample collected before field application. Half‐life values (t1/2) for propoxur showed similar trends to the results of mineralization. After a single application of propoxur, degradation in turfgrass soil was enhanced. Such enhancement lasted less than 12 months for the subsurface, but more than 12 months for the surface. A strain ofArthrobactersp. capable of degrading propoxur was isolated from the soil.

ISSN:0360-1234    

DOI:10.1080/03601239209372800

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This study was conducted to examine adsorption and the utility of Koc for the pesticides carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate), metalaxyl (N‐(2,6‐dimethylphenyl)‐N‐(2‐methoxyacetyl) alanine methyl ester), and simazine (6 chloro‐?,?'‐diethyl‐1,3,5‐triazine‐2,4‐diamine). Adsorption parameters for these pesticides were measured in the laboratory on samples from 12 western Washington soil layers. Predicted transport of the 3 pesticides using Koc values from the literature and from this study as model inputs were compared with field observations. Carbofuran was the least strongly adsorbed of the three pesticides. Carbofuran adsorption correlated well with soil organic carbon content. Koc values calculated for carbofuran were similar over a range of soils from both this study and other literature. Metalaxyl appeared to be preferentially adsorbed on soil mineral surfaces, and meaningful Koc estimates could not be obtained. Simazine behavior was intermediate between carbofuran and metalaxyl. For carbofuran and simazine, reasonable predictions of pesticide transport could be made using published Koc data for model inputs. Site‐specific adsorption parameters are probably necessary to characterize metalaxyl transport.

ISSN:0360-1234    

DOI:10.1080/03601239209372801

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Aqueous tank mixes of permethrin, fenitrothion,Bacillus thuringiensis(B.t.), diflubenzuron (DFB), and glyphosate containing different amounts of Triton® X‐114, a nonionic surfactant, were prepared. Glyphosate formed clear solutions, permethrin and fenitrothion formed emulsions, DFB and B.t provided suspensions. Emulsion stability of permethrin and fenitrothion increased with increasing surfactant level, while the emulsion drop size decreased.

ISSN:0360-1234    

DOI:10.1080/03601239209372802

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Effects of ionizing radiation on brain myelination and some physical development parameters were studied in laboratory rats (Fisher F‐344 inbred strain). Rats were treated with three different doses of radiation (150 rad, 15 rad, and 6.8 rad) delivered on the 20th day of prenatal life. Exposure to 150 rad reduced body, brain, ovary, kidney, heart and spleen weights. Prenatal exposure to 150 rad of radiation reduced the cerebral cortex weight by 22 percent at 30 days of age, and 20 percent at 52 days of age which caused a reduction in cerebral cortex myelin content by 20 and 23 percent at the ages of 30 and 52 days respectively. This dose did not affect the myelin content of the cerebellum or the brain stem, or the myelin concentration (mg myelin/g brain tissue) of the cerebral cortex, cerebellum, and the brain stem. The cerebral cortex weight of the 15 rad treated rats was reduced at the age of 30 days. Exposure to 15 rad, and 6.8 rad did not affect either the myelin content or the myelin concentration of these brain areas.

ISSN:0360-1234    

DOI:10.1080/03601239209372803

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor