Polyphenols were extracted from the rape of Israeli olive oil using hexane, acetone and ethanol in a simple sequential procedure yielding three fractions (A,B,C). Fraction A (extracted with hexane) contained few polyphenols (0.05%), while Fraction B (extracted with acetone) and Fraction C (extracted with ethanol) contained about 5% polyphenols each. Fractions B and C were also found to contain the highest ortho‐di‐phenol concentration (about 3%). The addition of purified Fraction B at a level of 100 ppm to refined olive or soybean oils partially inhibited the oxidative deterioration when the oils were stored in the dark at 100 C.

Quantitative exposure assessments made using biologically relevant markers will facilitate epidemiological studies of risk from environmental carcinogens. Blood proteins are readily accessible macromolecules that have been shown to be targets for activated chemical carcinogens. Serum albumin is quantitatively the most abundant target for aflatoxin B1 and the measurement of aflatoxin-serum albumin adducts has been used to detect exposed individuals. The goal of these experiments was to devise an analytical procedure that would increase the overall recovery of aflatoxin adducts in serum albumin, and thereby improve the accuracy of exposure monitoring. The method developed consisted of the following procedures. Proteins were precipitated from serum (< or = 100 microliters) with 80% ammonium sulfate, with incubation at 4 degrees C for 2 h. Following dialysis against phosphate-buffered saline (pH 7.0 for 3 h at 4 degrees C), the proteins were digested with protease (Pronase) (1:4.1 w/w enzyme:protein) for 15 h at 37 degrees C with shaking. Enzyme and other undigested proteins were precipitated with acetone (1:2 v/v, 40 min, 4 degrees C). After evaporation of the acetone under vacuum, levels of aflatoxin B1-albumin adducts were determined by radioimmunoassay carried out on 300 microliters fractions. This procedure obviated the isolation of albumin prior to analysis and reduced interference in the radioimmunoassay. High recoveries of aflatoxin B1 adducts were achieved together with a low limit of detection. The applicability of the procedure in epidemiological studies of human aflatoxin exposure was illustrated by results of analysis of aflatoxin-albumin adducts in serum samples from residents of Chongming Island, People's Republic of China.

In vitro dialysis using human blood and in vivo extracorporeal haemodialysis trials with dogs, in the presence and absence of various chelating agents, showed that haemodialysis alone facilitated efficient removal of the metal, even in the absence of any of the chelating agents. In vitro haemodialysis for 5 hr without chelating agents caused the removal of 85% of the arsenic (As) added to the blood 1 hr before the beginning of the treatment. Ten-33% of the single dose given to the dogs, were removed into the dialysate during the first treatment and 8-15% during the second. The amounts of As excreted in the urine of dogs given 0.25 mg As/kg b.wt./day for 6 days were 6.8-7.4 mg As/24 hr, while the same amounts of the metal were removed into the dialysate during haemodialysis for 5 hr. This demonstrates the advantage of employing haemodialysis over the conventional treatment for the enhanced removal of As from the body.

Reaction ofsyntheticN-(2'-deoxyguanosin-8-yl)-4-amlnobiphenyl Analysis of human DNA samples with existing methods can produce conflicting results (2, 10), emphasizing the utility of alternative methodologies. Our objective was to develop a method for detecting carcinogen-DNA adducts that could be broadly applicable to carcinogens representing diverse chemical classes, have sensitivity adequate to detect adduct levels resulting from ambient exposures, be capable of identifying individual adducts as well as mixtures resulting from complex exposures, have potential for quantifying adduct recovery and structural identification of specific carcinogen adducts, and utilize readily available reagents and equipment. The experimental strategy for a method addressing these objectives, based on chemical derivatization of mononucleosides, is summarized in Fig. 1. DNA is digested enzymatically and adducted nucleosides are separated from unmodified nucleosides either by reversed-phase chromatography, for bulk separation, or by immunoaffnmity purification of specific carcinogen adducts for which monoclonal antibodies are available. For quantification of adducts of specific carcinogens, adducted nucleosides isolated by immunoaffinity purification can be subjected directly to acylation with t-butoxycarbonyl-L-[35S]methionine, N-hydroxysuccinimidyl ester (35S-TBM-NHS), for identification and quantification.Alternatively, adducted nucleosides can be acylated as a mixture, after which total adduct levels can be determined by HPLC separation, and in parallel, specific carcinogen adducts can be determined by immunoaffinity purification with monoclonal antibodies. Nucleoside adducts are acylated with an 35S-TBM-NHS reagent previously used for protein labeling through reaction with primary amine groups (11,12). After the reaction under conditions optimized for each class of adducts, the derivatives are chromatographically separated by HPLC and radioactivity was quantified with a flow-through liquid scintillation detector. Yields at each step and overall recovery can be quantified through the use of internal standards and the acylation products identified by use of authentic reference nucleosides. MATERIALS AND METHODSChemicals were purchased as follows: 2'-deoxyguanosine and Sephadex LH-20 from Sigma; 4-aminobiphenyl, triethylamine (TEA), and N',N'-diisopropylcarbodiimide (DIC) from Aldrich; 2'-deoxy-1',2'-[3H]guanosine 5'-triphosphate

The effect of ethylenediamine tetraacetic acid (EDTA), glutathione (GSH), citrate and 2,3-dimercaptosuccinic acid (DMSA) on the elimination of cadmium (Cd) from human blood, by complexing haemodialysis, was investigated in vitro. A significant increase in elimination rate was observed with all four chelators compared to that observed without chelators. EDTA was found to be the most effective agent, which at a level of 0.01M in the dialysate facilitated elimination of 80% of the blood Cd originally present.