Urinary mutagenicity as a biomarker in workers exposed to benzidine: correlation with urinary metabolites and urothelial DNA adducts

Urinary mutagenicity has been used in occupational and epidemiological studies for over two decades as a cost-effective, general biomarker of exposure to genotoxic agents. However, few studies have compared urinary mutagenicity to additional biomarkers determined among low- and high-exposed groups. To address this issue, we evaluated the relationship between urinary mutagenicity and other types of biomarkers in a cross-sectional study involving 15 workers exposed to the urinary bladder carcinogen benzidine (BZ, high exposure), 15 workers exposed to BZ-dyes (low exposure), and 13 unexposed controls in Ahmedabad, India. Urinary organics were extracted by C18/methanol and evaluated for mutagenicity in the presence of S9 in the Salmonella strain YG1024, which is a frameshift strain that overproduces acetyltransferase. The results were compared to biomarker data reported recently from the same urine samples (Rothman et al., Proc. Natl Acad. Sci. USA, 93, 5084- 5089, 1996) that included a metabolite biomarker (the sum of the urinary levels of BZ + N-acetylbenzidine + N,N'-diacetylbenzidine) and a DNA adduct biomarker [a presumptive N-(3'-phosphodeoxyguanosin-8-yl)- N'-acetylbenzidine (C8dG-ABZ) DNA adduct in exfoliated urothelial cells]. The mean +/- SE urinary mutagenicity (revertants/micromol of creatinine) of the low-exposure (BZ-dye) workers was 8.2 +/- 2.4, which was significantly different from the mean of the controls (2.8 +/- 0.7, P = 0.04) as was that of the mean of the high-exposure (BZ) workers (123.2 +/- 26.1, P < 0.0001). Urinary mutagenicity showed strong, positive correlations with urinary metabolites (r = 0.88, P < 0.0001) and the level of the presumptive C8dG-ABZ urothelial DNA adduct (r = 0.59, P = 0.0006). A strong association was found between tobacco use (bidi smoking) and urinary mutagenicity among the controls (r = 0.68, P = 0.01) but not among the exposed workers (r = 0.18, P = 0.11). This study confirms the ability of a biomarker such as urinary mutagenicity to detect low-dose exposures, identify additional genotoxic exposures among the controls, and correlate strongly with urinary metabolites and DNA adducts in the target tissue (urinary bladder epithelia) in humans.      

The 185delAG BRCA1 mutation originated before the dispersion of Jews in the diaspora and is not limited to Ashkenazim

The 185delAG mutation in BRCA1 is detected in Ashkenazi Jews both in familial breast and ovarian cancer and in the general population. All tested Ashkenazi mutation carriers share the same allelic pattern at the BRCA1 locus. Our previous study showed that this 'Ashkenazi' mutation also occurs in Iraqi Jews with a similar allelic pattern. We extended our analysis to other non-Ashkenazi subsets: 354 of Moroccan origin, 200 Yemenites and 150 Iranian Jews. Heteroduplex analysis complemented by direct DNA sequencing of abnormally migrating bands were employed. Four of Moroccan origin (1. 1%) and none of the Yemenites or Iranians was a carrier of the 185delAG mutation. BRCA1 allelic patterns were determined for four of these individuals and for 12 additional non-Ashkenazi 185delAG mutation carriers who had breast/ovarian cancer. Six non-Ashkenazi individuals shared the common 'Ashkenazi haplotype', four had a closely related pattern, and the rest ( n = 6) displayed a distinct BRCA1 allelic pattern. We conclude that the 185delAG BRCA1 mutation occurs in some non-Ashkenazi populations at rates comparable with that of Ashkenazim. The majority of Jewish 185delAG mutation carriers have a common allelic pattern, supporting the founder effect notion, but dating the mutation's origin to an earlier date than currently estimated. However, the different allelic pattern at the BRCA1 locus even in some Jewish mutation carriers, might suggest that the mutation arose independently.      

Effects of social status and moderate alcohol consumption on mammary gland and endometrium of surgically postmenopausal monkeys

OBJECTIVE: To evaluate the effects of social subordination stress and chronic moderate alcohol consumption on indices of breast and endometrial cancer risk. DESIGN: Forty-six adult, ovariectomized, cynomolgus monkeys (Macaca fascicularis) were trained to voluntarily drink a placebo or a two-drink/day equivalent of ethanol (0.5 g/kg), 5 days a week for 26 months, the latter resulting in average blood alcohol levels of 42 mg/100 mL. Indices of cell proliferation and sex steroid receptor abundance were measured. RESULTS: Compared with dominants, socially subordinate females had increased cell proliferation and proportions of glandular (P < 0.02) and epithelial tissue (P = 0.009) and less stroma (P < 0.02) in endometrium, and increased tissue thickness in breast (P < 0.05). There was no evidence of increased risk of breast or endometrial cancer with chronic moderate alcohol consumption, as indicated by markers of cell proliferation and sex steroid receptor abundance. Chronic moderate alcohol consumption did not effect circulating sex steroid concentrations (all P > 0.10). The adipocyte hormones leptin and adiponectin were correlated with indices of cell proliferation and sex steroid receptor abundance. CONCLUSIONS: These observations suggest that social status was more important than chronic moderate alcohol consumption in endometrial and breast biology of surgically postmenopausal females. Endogenous sex steroid metabolism was not significantly affected by chronic moderate alcohol exposure consistent with the lack of estrogen-like effects on breast and endometrium. Social subordination stress was associated with initial cellular changes that may increase endometrial cancer risk. Ovariectomized cynomolgus monkeys may be a useful model for the study of effects of social factors and obesity on breast and endometrial cancer risk.     

Permissive recognition of immunodominant determinants of the retinal S- antigen in different rat strains, primates and humans

The majority of antigenic peptides exhibit restriction in their interaction with the MHC molecules on antigen-presenting cells of different haplotypes. Certain peptides, however, are "permissive': they bind strongly to different MHC molecules and are selected as the immunodominant epitopes by animals using these MHC gene products. Here we show for the first time that several peptides from four regions of the sequence of human S-antigen (H-SAg), a retinal-specific protein, demonstrate high levels of permissiveness. Each of these peptides was found to be immunodominant in at least some of four inbred rat strains and five cynomolgus monkeys, immunized with whole H-SAg. Moreover, some of these peptides were recognized by lymphocytes from four normal controls and four patients with uveitis who responded against the H-SAg molecule. On the other hand, the permissive peptides stimulated marginal or no response in cultures of Lewis rats injected with adjuvant alone, or rat and human cell lines specific to other antigens, thus demonstrating that these peptides do not carry any non-specific mitogenic activity. One peptide, 29, which was found immunodominant in the monkeys, the uveitis patients and Lewis rats, is highly immunopathogenic in this rat strain. No good correlation between immunodominance and immunopathogenicity was found with other H-SAg peptides. The finding of cross-species permissiveness among peptides of H-SAg and similar observations with myelin proteins suggest that permissiveness could be quite prevalent among peptides of immunopathogenic antigens.      

Design and synergistic effect of nano-sized epoxy-NiCo2O4 nanocomposites for anticorrosion applications

In the present work, we evaluated the corrosion inhibition properties of a ligand and mixed metal oxide nanocomposite. The ligand and mixed nickel–cobalt complex were synthesized using 1-naphthoic acid and aminoguanidine with the formulae [C₁₁H₇O₂(CN₄H₅)(CN₄H₆)]·H₂O and {Ni–Co[(CH₅N₄)₂(C₁₁H₇O₂)₂]}·H₂O, respectively. After their synthesis, physicochemical techniques such as CHNS analysis, infrared and UV-visible spectroscopy, thermal analysis, and X-ray diffraction (XRD) were employed to characterize both the synthesized ligand and nickel–cobalt complex. The metal oxide prepared from the decomposition of the metal complex was also characterized using several techniques to confirm its bonding and structure. In addition, the corrosion inhibition efficiency of the epoxy-ligand and epoxy-NiCo₂O₄ nanocomposite on mild steel (MS) in 3 M hydrochloric acid (HCl), 1.5 M sulfuric acid (H₂SO₄), and 0.5 M phosphoric acid (H₃PO₄) solution was examined and compared using weight loss measurements, Tafel plots, isotherms and electrochemical impedance spectroscopy (EIS). The results from the electrochemical studies disclosed that the epoxy coating of mixed metal oxides with 0.8 ppm concentration yielded excellent corrosion protection. The SEM images of mild steel and mild steel coated with epoxy-ligand/epoxy-NiCo₂O₄ in HCl confirmed the anti-corrosive behavior of the synthesized compounds. Hence, the as-prepared material can be a next-generation tool for sustainable anti-corrosive coatings.

This study reports the synthesis of nano-sized epoxy-NiCo₂O₄ nanocomposites and their anti-corrosive efficiency to attain sustainable development.     

Puberty in perinatal HIV-1 infection: a multicentre longitudinal study of 212 children

OBJECTIVE: To define age at entry into Tanner stages in children with perinatal HIV-1 infection. DESIGN: Multicentre longitudinal study including 212 perinatally HIV-1-infected children (107 girls and 105 boys) followed-up during puberty (from 8 and 9 years onwards in girls and boys, respectively). Healthy children (843 girls and 821 boys) provided reference percentiles. P2 or B2 stages in girls and P2 or G2 stages in boys defined onset of puberty. METHODS: The cumulative probability [95% confidence limit (CI)] of entry into each stage at different ages was estimated by the Kaplan-Meier product-limit method; differences were evaluated by log rank test. Relationships were tested using the Spearman's rank correlation coefficient. RESULTS: Ages of girls [years (95%CI)] at P2 [12.9 (12.6-13.2)], P3 [13.4 (13.0-13.8)], P4 [14.6 (14.0-15.2)], B2 [12.7 (12.2-13.2)], B3 [13.3 (12.8-14.0)] and B4 [14.6 (14.0-15.2)] stages were > 97th percentile (> or = 21 month delay) of controls. Ages of boys [years (95%CI)] at P2 [12.6 (12.1-13.1)], P3 [13.9 (13.4-14.4)], P4 [14.9 (14.2-15.6)], G2 [12.1 (11.5-12.7)], G3 [13.6 (13.1-14.1)] and G4 [14.9 (14.1-15.7)] stages were at the 75-97th percentiles (< or = 15 month delay). Age at onset of puberty was not related to clinical and immunological condition, antiretroviral treatment, weigh for height and age at onset of severe disease or immune suppression. CONCLUSION: Perinatal HIV-1 infection interferes with sexual maturation. The mechanisms by which this occurs should be elucidated and intervention strategies designed. Intervention could save much psychological distress, since associated linear growth failure can exacerbate adolescents' feelings of being different and unwell.     

Effect of the early use of the anti-tumor necrosis factor adalimumab on the prevention of job loss in patients with early rheumatoid arthritis

OBJECTIVE: To compare work disability and job loss in early rheumatoid arthritis (RA) patients receiving adalimumab plus methotrexate (adalimumab + MTX) versus MTX alone. METHODS: In this multicenter, randomized, controlled trial, patients with RA for <2 years who had never taken MTX and who self-reported work impairment were randomized to adalimumab + MTX or placebo + MTX for 56 weeks. Primary outcome was job loss of any cause and/or imminent job loss at or after week 16. Secondary outcomes included disease activity, function (Health Assessment Questionnaire [HAQ] score), and RA quality of life (RAQoL) questionnaire score. Work was evaluated with work diaries and the RA Work Instability Scale. RESULTS: Although job loss during the 56-week study was significantly lower with adalimumab + MTX (14 of 75 patients) compared with MTX alone (29 of 73 patients; P=0.005), the primary end point was not met (12 of 75 versus 20 of 73 patients; P=0.092), likely owing to early drop out in the MTX group. There were significant improvements in American College of Rheumatology 20% response criteria, 28-joint Disease Activity Score, DeltaHAQ, DeltaRAQoL, and working time lost in the adalimumab + MTX group. Twenty-four serious adverse events were reported in 17 participants, with no differences between groups. CONCLUSION: Adalimumab + MTX reduced job loss and improved productivity in early RA when compared with MTX alone, which supports the early use of anti-tumor necrosis factor therapy and suggests its cost efficacy.     

Reduction in the incidence of myocardial infarction in patients with rheumatoid arthritis who respond to anti-tumor necrosis factor alpha therapy: results from the British Society for Rheumatology Biologics Register

OBJECTIVE: Rheumatoid arthritis (RA) is associated with an increased risk of coronary artery disease, possibly acting via shared mechanisms of inflammation. This study was undertaken to test the hypothesis that the powerful antiinflammatory effect of anti-tumor necrosis alpha (anti-TNFalpha) therapy might lead to a reduction in the incidence of myocardial infarction (MI) in patients with RA. METHODS: Using data from the British Society for Rheumatology Biologics Register, a national prospective observational study, we compared MI rates in 8,670 patients with RA treated with anti-TNFalpha and 2,170 patients with active RA treated with traditional disease-modifying antirheumatic drugs (DMARDs). RESULTS: Through July 2006, 63 MIs occurred in the anti-TNFalpha cohort during 13,233 person-years of followup and 17 MIs occurred in the DMARD cohort during 2,893 person-years of followup, equivalent to a rate of 4.8 events per 1,000 person-years and 5.9 events per 1,000 person-years, respectively. After adjustment for baseline risk factors, there was no reduction in the rate of MI in the anti-TNFalpha cohort compared with the DMARD cohort (incidence rate ratio 1.44 [95% confidence interval 0.56-3.67]). In an analysis of anti-TNFalpha-treated patients who responded to the treatment within 6 months versus those who did not, MI rates were found to be 3.5 events per 1,000 person-years in responders and 9.4 events per 1,000 person-years in nonresponders. The adjusted incidence rate ratio (95% confidence interval) for responders compared with nonresponders was 0.36 (0.19-0.69). CONCLUSION: These results indicate that RA patients treated with anti-TNFalpha do not have a lower incidence of MI compared with RA patients treated with traditional DMARDs. However, the risk of MI is markedly reduced in those who respond to anti-TNFalpha therapy by 6 months compared with nonresponders. This finding supports the notion that inflammation plays a pivotal role in MI.