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Biomedical subjects

E D Bowman

Publications and source records attributed to E D Bowman.

At least 37 records · Page 2Linked to original sources
PubMed1995

Solid matrix, room temperature phosphorescence identification and quantitation of the tetrahydrotetrols derived from the acid hydrolysis of benzo[a]pyrene-DNA adducts from human lung.

A new method, suitable for human biomonitoring, that uses room temperature phosphorescence for the detection of DNA damage by carcinogenic metabolites of polycyclic aromatic hydrocarbons is described. Samples of human lung DNA (1 mg) that had been subjected to immunoaffinity chromatography (anti-benzo[a]pyrene-diol-epoxide deoxyguanosine monoclonal antibodies) were acid hydrolyzed (0.1 N HCl, 90 degrees C, 3 h) and the resulting DNA lung hydrolyzates separated by high performance liquid chromatography. Relevant fractions were combined with a solid matrix support which consisted of a mixture of alpha-cyclodextrin (alpha-CD):NaCl (1:9) or alpha-CD:TINO3: aNO3 (1:1:8). The dried and powdered sample-matrix material was analyzed by phosphorescence spectroscopy at room temperature. Certain fractions of human lung samples were found to contain materials that yielded phosphorescence spectra that were indistinguishable from those produced when an authentic r-7, t-8, t-9, c-10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene reference standard was analyzed. The data confirm previous studies that have reported the presence of r-7, t-8 dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene-DNA adducts in human tissues at levels of 1 adduct/10(7)-10(8) nucleotides. The alpha-cyclodextrin solid matrix, room temperature phosphorescence technique was performed with a commercially available instrument, but is 50 times more sensitive than the synchronous fluorescence spectroscopic technique previously used.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1994

Identification of 1-hydroxypyrene glucuronide as a major pyrene metabolite in human urine by synchronous fluorescence spectroscopy and gas chromatography-mass spectrometry.

Humans are exposed to polycyclic aromatic hydrocarbons (PAHs) from various occupational, environmental, medicinal and dietary sources. The measurement of specific PAH metabolites, particularly 1-hydroxypyrene, in human urine treated with deconjugating enzymes (e.g. beta-glucuronidase) has been extensively used as a means of assessing recent exposure to PAHs. We have examined pyrene metabolites in human urine prior to enzymatic deconjugation in order to determine the relative proportions of conjugated and unconjugated pyrene metabolites. The analytical method utilized immunoaffinity chromatography, high performance liquid chromatography (HPLC) and the complementary techniques of synchronous fluorescence spectroscopy (SFS) and gas chromatography-mass spectrometry (GC-MS) to measure pyrene-containing metabolites. SFS analysis of immunoaffinity-purified urine samples showed fluorescence spectra characteristic of the pyrene moiety (using wavelength differences of 34 nm, 54 nm and 102 nm). These spectra are produced by several PAHs containing the pyrene moiety. HPLC analysis with fluorescence detection indicated that the major fluorescent metabolite in immunoaffinity-purified urine was much more polar than simple hydroxylated metabolites of pyrene (1-hydroxypyrene) or benzo[a]pyrene (benzo[a]pyrene-diols or -tetrols). Following digestion with beta-glucuronidase, this metabolite co-chromatographed with authentic 1-hydroxypyrene and exhibited fluorescence spectra characteristic of 1-hydroxypyrene, suggesting that the major metabolite was a glucuronide conjugate of 1-hydroxypyrene. This was subsequently confirmed by GC-MS analysis of trimethylsilyl derivatives of the major metabolite; both 1-hydroxypyrene and glucuronic acid were detected independently as derivatized products. Since 1-hydroxypyrene glucuronide is approximately 5-fold more fluorescent than 1-hydroxypyrene, it may provide a more sensitive biomarker for assessing exposure to pyrene in mixtures of PAHs.

Chromatography, High Pressure Liquid↗
PubMed1994

Determination of the allelic frequencies of an L-myc and a p53 polymorphism in human lung cancer.

The L-myc and p53 genes have been implicated in lung cancer. Both of these genes have restriction fragment length polymorphisms (RFLPs) that could account for differential expression or activity of variant forms. An EcoRI restriction site in the L-myc gene was previously reported to be a predictor of poor prognosis in Japanese lung cancer patients. There are several RFLPs in the p53 gene. In exon 4 there is a polymorphism that codes for either an arginine or proline residue at codon 72. We previously reported the frequency of DNA-RFLPs at these gene loci revealed by EcoRI and AccII respectively. Here we report results from a study comparing lung cancer cases (n = 31) with chronic obstructive pulmonary disease controls (n = 49). No association was found between these RFLPs and disease status. Previous observations that the frequencies of these RFLPs varied by race were confirmed. The p53 arginine allele was found to be more common in Caucasians (0.71) than African-Americans (0.50). The EcoRI restriction site present allele in L-myc was more frequent in African-Americans (0.71) than Caucasians (0.49). Thus, the allelic frequency for L-myc was similar in African-Americans to that reported for Japanese, and the allelic frequency for p53 was similar in Caucasians to that reported for Japanese.

Base Sequence↗
PubMed1993

Polycyclic aromatic hydrocarbon-DNA adducts in human lung and cancer susceptibility genes.

Molecular dosimetry for polycyclic aromatic hydrocarbon-DNA adducts, genetic predisposition to cancer, and their interrelationships are under study in numerous laboratories. This report describes a modified 32P-postlabeling assay for the detection of polycyclic aromatic hydrocarbon-DNA adducts that uses immunoaffinity chromatography to enhance chemical specificity and quantitative reliability. The assay incorporates internal standards to determine direct molar ratios of adducts to unmodified nucleotides and to assess T4 polynucleotide kinase labeling efficiency. High performance liquid chromatography is used to assure adequacy of DNA enzymatic digestion. The assay was validated using radiolabeled benzo(a)pyrene-diol-epoxide modified DNA (r = 0.76, P < 0.05) thereby assessing all variables from enzymatic digestion to detection. Thirty-eight human lung samples were examined and adducts were detected in seven. A subset of samples also was examined for benzo(a)pyrene-diol-epoxide-DNA adducts by immunoaffinity chromatography, high performance liquid chromatography, and synchronous fluorescence spectroscopy. A high correlation between the two assays was found (P = 0.006). The lung samples were then analyzed by the polymerase chain reaction for the presence of mutations in the cytochrome P-450 (CYP) 1A1 and glutathione S-transferase mu (GST mu) genes. A positive association was identified for adduct levels and GST mu null genotypes (P = 0.038). No correlation was found between polycyclic aromatic hydrocarbon-adduct levels and CYP1A1 exon 7 mutations. Age, race, and serum cotinine were not related to adduct levels. Multivariate analysis indicated that only the GST mu genotype was associated with polycyclic aromatic hydrocarbon-DNA adduct levels. This work demonstrates that the 32P-postlabeling assay can be modified for chemically specific adduct detection and that it can be used in the assessment of potentially important genetic factors for cancer risk. The absence of a functional GST mu gene in humans is likely one such factor.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1993

7-Alkyldeoxyguanosine adduct detection by two-step HPLC and the 32P-postlabeling assay.

7-Alkyldeoxyguanosine DNA adducts may be a marker for some N-nitroso compound exposures and subsequent human cancer risk. A sensitive and highly specific assay for the detection of 7-methyl-2'-deoxyguanosine-3'-monophosphate (7-methyldGp) and 7-ethyl-2'-deoxyguanosine-3'-monophosphate (7-ethyldGp) has been developed by combining two different HPLC purification steps with the 32P-postlabeling assay. We previously reported that ion-pair reverse-phase (IP) chromatography coupled with the 32P-postlabeling assay detects 7-methyldGp in human lung, but have found that other nucleotides and unknown adducts co-elute. Thus, weak anion exchange (AE) HPLC was added in tandem with IP HPLC prior to the 32P-postlabeling assay. 2'-Deoxyguanosine-3'-monophosphate (dGp) is incorporated into the assay as an internal standard for the assessment of enzyme labeling efficiency and adduct recovery. The methodology was validated using radiolabeled DNA and liquid scintillation counting, which accounts for adduct loss from enzymatic digestion to detection. Levels of 7-ethyldGp also were correlated with accelerator mass spectrometry. The overall adduct recovery with this method was 58% for 7-methyldGp and 98% for 7-ethyldGp. The detection limit for both assays using 100 micrograms of DNA was one adduct in 10(8) unmodified dGp. 7-MethyldGp and 7-ethyldGp levels were determined in ten human lung samples at levels of 1.4-5.4 and 0.6-3.1 adducts per 10(7) dGp respectively, and in five human lymphocyte samples at levels of 5.0-8.3 and 0.3-1.4 adducts per 10(7) dGp respectively. Combining the two HPLC purification steps and the 32P-postlabeling assay attains chemical specificity, retains sufficient quantitative sensitivity and should be useful in human biomonitoring studies.

Animals↗
PubMed1993

Detection of metabolites of polycyclic aromatic hydrocarbons in human urine.

A non-invasive assay has been developed for the recovery of r-7,t-8,t-9,c-10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[alpha]-pyrene (BP-7,10/8,9-tetrol) from human urine. This tetrol is excreted as a metabolite of benzo[alpha]pyrene (BP) in a process catalyzed by cytochrome P450 enzymes and epoxide hydrolases. Urine was hydrolysed to release activated benzo[alpha]-pyrene-diol-epoxides covalently bound to macromolecular species or conjugated tetrols. The relatively non-polar organic molecules from urine hydrolysates were collected on octadecasilane chromatography columns (Sep-Paks). Materials eluted in solvent (80% CH3OH), were further purified on immunoaffinity columns with antibodies raised against anti-N2-[10(7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo [alpha]pyrenyl)]-guanosine. HPLC was then used to isolate BP-7,10/8,9-tetrol, which was quantitated by synchronous fluorescence spectroscopy (SFS). This assay detected 0.24-3.12 pmol BP-7,10/8,9-tetrol per ml urine (limit of detection 0.01 pmol/ml, given 10 ml urine), in four study subjects. Reproducibility was assessed by adding tritium labeled BP-7,10/8,9-tetrol (1500 fmol) to a urine sample previously identified to contain the tetrol at levels below the limit of detection of the fluorescence assay; a recovery of > 30% of the added radioactivity was achieved (510 +/- 64 fmol, mean +/- SD, n = 3). Because HPLC alone was not sufficient to isolate materials for quantitation by SFS directly from human urine, immunoaffinity chromatography was found to be a necessary preparatory step in BP-7,10/8,9-tetrol isolation. These data demonstrate the presence of tetrahydrotetrol metabolites of BP in human urine and suggest that measurement of BP-7,10/8,9-tetrol and other polycyclic aromatic hydrocarbon-tetrols may prove to be valuable dosimeters of human internal exposure to polycyclic aromatic hydrocarbons.

Benzo(a)pyrene↗
PubMed1993

Standardization of the 32P-postlabeling assay for polycyclic aromatic hydrocarbon-DNA adducts.

A modified method for the 32P-postlabeling assay that permits standardized quantitation for specific polycyclic aromatic hydrocarbon (PAH)-DNA adducts is described. This method has been designed to test the components of the 32P-postlabeling assay for use in the chemically specific detection of individual adducts with the ultimate goal of testing the biological significance of PAH-DNA adducts in humans. The approach relies upon high performance liquid chromatography (HPLC), concomitant labeling of 2'-deoxyguanosine (dGp) as an internal standard and thin layer chromatography (TLC), which identifies unmodified nucleotides along with PAH-DNA adducts on the same TLC plate. This method assesses labeling efficiency, detects the presence of unknown inhibitors, assesses the adequacy of digestion (when combined with HPLC) and allows for the development of calibration curves for directly determined molar ratios (adduct:internal standard). Chemically synthesized adduct standards and quantitative 32P-postlabeling data have been corroborated by UV spectroscopy, fluorescence spectroscopy and liquid scintillation counting where radiolabeled materials were available. Labeling efficiencies of the PAH-DNA adducts were found to be up to 100-fold less than expected and depended upon both the adduct and adduct levels (lower levels being less efficiently detected). The presence of unmodified nucleotides resulted in a 1.5-fold lower labeling efficiency. Mixtures of selected PAH-DNA adducts did not affect the labeling efficiencies of each other. The data suggest that previous 32P-postlabeling assay studies for PAH-DNA adducts may have underestimated adduct levels due to variations in labeling efficiency.

Adenosine Triphosphate↗
PubMed1993

Detection of polycyclic aromatic hydrocarbon-DNA adducts in human lung.

Synchronous fluorescence spectroscopy has been combined with immunoaffinity chromatography (IAC) and HPLC to detect polycyclic aromatic hydrocarbon (PAH)-DNA adducts and measure r-7,t-8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA adducts in human tissues and cells. A monoclonal antibody (8E11) that recognizes a range of PAH-DNA adducts, but not chemically unrelated adducts, was used to prepare IAC columns. Samples of DNA (25 from human lung and 8 positive and negative controls) were hydrolyzed enzymically and subjected to IAC. Adducts captured by the antibodies and eluted in NaOH (50 mM) were analyzed for fluorescent properties. The spectral fluorescence excitation-emission matrices suggested the presence of mixtures of PAH-DNA adducts in some of the eluates. The eluates were subsequently hydrolyzed with acid (HCl, 0.1 N, 3 hr) and reanalyzed by synchronous fluorescence spectroscopy using a wavelength differential of 34 nm. In 6 of the 25 human lung DNA samples, materials with HPLC retention times identical to benzo[a]pyrene-7,10/8,9-tetrahydrotetrol were found to have fluorescence characteristics indistinguishable from pyrene. Comparisons with appropriate standards indicated that BPDE-DNA adduct levels were between 1 and 40 adducts in 10(8) unmodified nucleotides. No correlation was observed between lung DNA-adduct levels and measures of recent smoking (serum cotinine), but tissue samples taken from different portions of the same lungs showed variation in the DNA adduct levels detected. This finding complicates interpretation of the data and has important implications for the design of future experiments.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1993

Combined micropreparative techniques with synchronous fluorescence spectroscopy or 32P-postlabelling assay for carcinogen-DNA adduct determination.

Methods for the detection of carcinogen-DNA adducts require both sensitivity and specificity. The 32P-postlabelling assay is highly sensitive but lacks adduct specificity. The strategy reported herein combines micropreparative techniques including HPLC and immunoaffinity chromatography (IAC) to enhance chemical specificity. The resultant assays have retained sensitivity for human DNA analysis. Combined HPLC and 32P-postlabelling has detected 7-methyldeoxyguanosine in human lung samples, while combined IAC and 32P-postlabelling has detected O6-methyldeoxyguanosine adducts in stomach tissue. The limits of detection are one adduct in 10(7) and 10(8) unmodified deoxyguanosine (dG), respectively. IAC was combined with 32P-postlabelling to detect polycyclic aromatic hydrocarbon (PAH)-DNA adducts in human lung. The detection limit was one adduct in 10(7) dG. Our laboratory has also employed synchronous fluorescence spectroscopy (SFS) for the detection of adducts formed from benzo[a]pyrene in human lung. Complex fluorescence matrices suggest the presence of other PAH-DNA adducts. Both the SFS assay and the 32P-postlabelling assay were applied to a series of human samples and a high correlation was found for adduct levels. The development of such assays using synthetic standards, internal standards, determination of calibration curves and validation with corroborating methods is required for chemically specific and sensitive adduct detection.

Benzo(a)pyrene↗
PubMed1992

Determinants of polycyclic aromatic hydrocarbon-DNA adducts in human placenta.

To determine the relative contributions of tobacco smoking and P-450 metabolism (cytochrome P-450IAI) in the formation of benzo(a)pyrenediol-epoxide and other polycyclic aromatic hydrocarbon-DNA adducts in vivo, 16 human placentas were assayed for aryl hydrocarbon hydroxylase activity and (+/-)r-7,t-8-dihydroxy-c-9,10-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene-DN A adduct levels. Immunoaffinity chromatography columns, conjugated with monoclonal antibodies raised against benzo(a)-pyrene-diol-epoxide-deoxyguanosine, were used to concentrate polycyclic aromatic hydrocarbon-DNA adducted nucleotides, and synchronous fluorescence spectroscopy was used specifically to detect r-7,t-8,t-9,c-10-tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BP-tetrol) extracted from acid hydrolysates of immunoconcentrated materials. Data were analyzed for associations with maternal dietary and smoking habits, umbilical cord blood cotinine levels, and placental aryl hydrocarbon hydroxylase levels. Complex mixtures of fluorescent materials were present in organic solvent extracts of acid hydrolysates of immunoconcentrated nucleotide-adducts from all placentas with patterns of fluorescence that may be associated with tobacco smoking determined by generation of spectral fluorescence excitation-emission matrices. BP-tetrols were detected in extracts from 8 placentas: 5 of 7 from smokers and 3 of 9 from nonsmokers. Placental aryl hydrocarbon hydroxylase activity was significantly higher in placentas from which BP-tetrols were extracted [3.9 +/- 2.4 [corrected] (mean +/- SE) pmol 3-hydroxybenzo(a)pyrene mg protein-1 min-1], than among placentas from which BP-tetrols were not extracted (0.4 +/- 0.2 [corrected] pmol 3-hydroxybenzo(a)pyrene mg protein-1 min-1) (P = 0.03, Student's t test). This association was independent of maternal smoking or umbilical cord blood cotinine levels. These results indicate that while maternal tobacco smoking is associated with the accumulation of putative, but as yet unidentified, polycyclic aromatic hydrocarbon-DNA adducts in placenta, metabolic capacity appears to be the principal determinant for the (+/-)r-7,t-8-dihydroxy-c-9,10 epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene-DNA adduct levels detected.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1992

Polycyclic aromatic hydrocarbon-DNA adducts and the CYP1A1 restriction fragment length polymorphism.

Human cancer risk assessment at a genetic level involves the investigation of carcinogen metabolism and DNA adduct formation. Wide interindividual differences in metabolism result in different DNA adduct levels. For this and other reasons, many laboratories have considered DNA adducts to be a measure of the biologically effective dose of a carcinogen. Techniques for studying DNA adducts using chemically specific assays are becoming available. A modification of the 32P-postlabeling assay for polycyclic aromatic hydrocarbon DNA adducts described here provides potential improvements in quantification. DNA adducts, however, reflect only recent exposure to carcinogens; in contrast, genetic testing for metabolic capacity indicates the extent to which carcinogens can be activated and exert genotoxic effects. Such studies may reflect both separate and integrated risk factors together with DNA adduct levels. A recently described restriction fragment length polymorphism for the CYP1A1, which codes for the cytochrome P450 enzyme primarily responsible for the metabolic activation of carcinogenic polycyclic aromatic hydrocarbons, has been found to be associated with lung cancer risk in a Japanese population. In a subset of individuals enrolled in a U.S. lung cancer case-control study, no association with lung cancer was found.

Blotting, Southern↗
PubMed1991

Fluorescence detection of benzo[a]pyrene--DNA adducts in human lung.

Improved techniques are described for the specific identification of benzo[a]pyrene-diolepoxide (BPDE)--DNA adducts in human tissues. Immunoaffinity chromatography, synchronous fluorescence spectroscopy and second-derivative synchronous fluorescence spectroscopy have previously been used to detect BPDE-DNA adducts in human placenta. Here we report how these methods, together with HPLC and the generation of complete fluorescence excitation--emission matrices, have been used to identify unequivocally BPDE-DNA adducts in samples of human lung. BPDE nucleotide adducts were isolated with immunoaffinity chromatography columns bearing antibodies raised against the (+/-)anti-7,8-diol-9,10-epoxide-deoxyguanosine adduct of benzo[a]pyrene. These adducts were hydrolyzed to tetrahydrotetrols and the hydrolysis products subjected to HPLC. The major product isolated by HPLC, benzo[a]-pyrene-7,10/8,9-tetrahydrotetrol, was determined by fluorescence spectroscopy. Using this method, levels of BPDE-DNA adducts in the range of 1-40 in 10(8) nucleotides were measured in 6 out of 25 samples, with a lower detection limit of one adduct in 10(8) nucleotides. The data may also indicate that adduct levels show regional variation in different parts of the same lung.

Adolescent↗
PubMed1991

Biochemical and molecular epidemiology of cancer.

Examples of practical approaches to molecular epidemiology of human cancer are described. Biomarkers of carcinogen exposure or inherited host factors for cancer susceptibility are discussed. Major advances have been made in the detection of carcinogenmacromolecular adducts through the use of high performance liquid chromatography, immunoaffinity chromatography, the 32P-postlabeling assay, enzyme immunoassays, gas chromatography/mass spectroscopy and synchronous spectrophotofluorimetry. The polycyclic aromatic hydrocarbon-DNA adducts are the most extensively studied in this field and together with antibodies to these adducts found in human serum, they have become useful indicators of exposure to carcinogens. Assays for various kinds of alkyl-DNA adducts have also been developed and the presence of these adducts have been documented in human tissues. Carcinogen-protein adducts have proven to be useful molecular dosimeters of carcinogen exposure. For example, 4-aminobiphenyl hemoglobin adducts are highly correlated with exposure to tobacco smoke. The study of the molecular aspects of interindividual differences in the metabolism and activation of xenobiotics and other genetic markers [DNA-restriction fragment length polymorphisms (RFLPs), mutations, and functional loss of specific genes in carcinogenesis] is an emerging new field that is discussed in the context of genetic susceptibility to cancer. The cytochrome P450 phenotypes and acetylation phenotype are examples of genetic markers that indicate an individual's potential for metabolism of exogenous substances. Further, inherited genetic polymorphic markers, e.g., DNA-RFLPs at protooncogene loci (HRAS-1 and L-myc) have been examined in a case-control study of lung cancer. Data concerning mutations of protooncogenes (H-, K-, and N-RAS) and tumor suppressor genes (retinoblastoma and p53 genes) in various common cancers are providing evidence of multiple genetic lesions that occur during the multistage process of carcinogenesis.

Biomarkers↗
PubMed1990

Purification and characterization of the Tetrahymena pyriformis P-C bond forming enzyme phosphoenolpyruvate phosphomutase.

In this paper the purification and characterization of the Tetrahymena pyriformis enzyme phosphoenolpyruvate phosphomutase are described. PEP phosphomutase was first fractionated from T. pyriformis cellular extract by using 70% ammonium sulfate. Chromatography of the crude protein fraction on a DEAE-cellulose column followed by phenyl-Sepharose column chromatography and then Bio-Gel P-200 column chromatography afforded pure PEP phosphomutase in an approximate overall yield of 70 units/150 g of cells. The maximum turnover number observed for PEP phosphomutase catalysis of the phosphonopyruvate----PEP reaction is 38 s-1 (25 degrees C). The enzyme was shown to be a homodimer of 38,000-dalton subunits and to require a divalent metal ion for activity. Mg2+ (relative Vm = 1), Co2+ (rel Vm = 0.5), Zn2+ (rel Vm = 0.4), and Mn2+ (rel Vm = 0.3) each satisfied the cofactor requirement. Binding of the physiological cofactor, Mg2+ (Ki = 0.3 mM at pH 7.5), and phosphonopyruvate (Km = 2 microM at pH 7.5) was found to be ordered, with cofactor binding preceding substrate binding. Within the pH range of 5-9 catalysis (Vm) was found to be pH independent, while phosphonopyruvate binding dropped at acidic and basic pH.

Animals↗
PubMed1990

Formation of polycyclic aromatic hydrocarbon-DNA adducts in peripheral white blood cells during consumption of charcoal-broiled beef.

The effect of ingesting charcoal-broiled (CB) beef on polycyclic aromatic hydrocarbon (PAH)-DNA adduct levels in nucleated peripheral white blood cells (WBCs) was examined in four healthy, non-smoking males who consumed an average of 280 g CB beef daily for 7 days. PAH-DNA adducts were quantitated by enzyme-linked immunosorbent assay. During the week of CB beef consumption, two individuals exhibited a 3- to 6-fold increase in PAH-DNA adducts above baseline levels observed during the month prior to CB beef consumption. In contrast, PAH-DNA adduct levels in the two other subjects did not increase. Thus, dietary sources of PAH can contribute to the PAH-DNA adduct load in peripheral WBCs in some individuals.

Adult↗
PubMed1989

Effects of running or weight lifting on self-concept in clinically depressed women.

Forty clinically depressed women were randomized to a running, weight lifting, or delayed treatment condition. Self-concept was assessed at baseline, pre-, mid-, and posttreatment for all subjects and at 1, 7, and 12 months for exercise groups. Significant improvements in self-concept were found for exercise groups relative to control groups. No significant differences between exercise groups were found, and improvements were reasonably well-maintained over time. Differential changes on dimensions of self-concept were not demonstrated. These results suggest that both running and weight lifting exercise programs improve self-concept in clinically depressed women.

Adult↗