摘要:

An improved radioreceptor assay (RRA), based on the method originally described by Korenman (1968), was used for the screening of urine samples of cattle for the presence of exogenous oestrogenic anabolic compounds, i.e. stilbenes and zeranol. The method includes extraction of the hormones from urine samples with a simultaneous purification using reversed‐phase C18 cartridges. HPLC is used to isolate the anabolics from the naturally occurring oestrogens. Fractions containing the stilbenes and zeranol are collected and subsequently quantified using the RRA with the oestrogen receptor, isolated from immature calf uteri, as binder and tritiated 17β‐oestradiol as tracer. Urine samples from untreated calves and cows, as well as samples from calves treated with zeranol/trenbolon acetate, dienoestrol or hexoestrol or samples containing diethylstilboestrol, were analysed using this RRA method. Sensitivity, specificity and predictive values were calculated at different classification levels (0.4, 0.5, 0.6 and 1.0 ng ‘apparent’ oestradiol per ml urine). An optimum sensitivity (89%) with a maximum specificity (95%) was reached at a classification level of 0.6 ng/ml. At this level the detection limits in urine samples are 0.5 ng/ml for hexoestrol, 0.6 ng/ml for diethylstilboestrol, 0.9 ng/ml for dienoestrol and 5.0 ng/ml for zeranol.

ISSN:0265-203X    

DOI:10.1080/02652038909373743

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The aim of this study was the evaluation of the effect of dietary imbalances on absorption and distribution of lead in the female Sprague‐Dawley rat. In this note preliminary results on the relationship between blood concentrations of lead and unbalanced diets are presented. Hyperproteic, hyperglycidic, hyperlipidic and balanced diets were prepared, and most of them included 15 mg/kg lead. Blood samples were collected at day 0, 21, 36, and 95 of the diets and analyzed by anodic stripping voltammetry (ASV). Lead uptake as a function of feed consumption was found to decrease in the order: balanced, hyperproteic and hyperglycidic, hyperlipidic diet. On the other hand lead blood levels were as follows (decreasing order): hyperlipidic, hyperproteic, hyperglycidic, balanced. Further research is being carried out on the influences of dietary imbalances on whole‐body distribution of lead.

ISSN:0265-203X    

DOI:10.1080/02652038909373744

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Results from a survey of stocks of unopened and opened food cans in 452 U.K. households are reported. About 8840 unopened cans were found, representing an average of ∼ 19 cans/household. Twelve per cent of the unopened cans were found to be more than 2 years old, 5% more than 3 years old and 3% more than 4 years old. A total of 156 open cans were identified in 88 households, that is in 20% of the households in the survey. Almost 30% of these cans had been stored for more than 2 days and about 10% had been stored for≥7 days. Since tin concentrations tend to rise in both unopened and opened cans on storage, this information confirmed the need for better stock rotation in the home and the need for further publicity.

ISSN:0265-203X    

DOI:10.1080/02652038909373745

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652038909373746

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652038909373747

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652038909373732

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor