Thyroid activity in cigarette smokers.

Recent studies have shown a possible relationship between cigarette smoking and endocrine function. Since changes in thyroid hormone concentrations can have a profound effect on overall metabolism as well as influencing both androgenic and estrogenic steroid activity, we investigated the relationship between cigarette smoking and thyroid function. Volunteers were divided into four groups according to self-reported and biochemical data, including blood carboxyhemoglobin, plasma cotinine, and thiocyanate, and were described as nonsmokers, light, moderate, and heavy smokers. Substantial decreases were found in serum thyroxine (T4) and triiodothyronine (T3) concentrations in heavy smokers compared with nonsmokers. Reduced serum thyroid hormone levels were not accompanied by a substantial change in serum thyrotropin concentrations. The free T4 index, free T3 index, and T4-T3 ratio were not substantially different for either group.

Cigarette smoking as a risk for cardiovascular disease. Part VI. Compensation with nicotine availability as a single variable.

In a biochemical investigation of human smoking behavior with filter cigarettes with high draw resistance that varied only in nicotine yield, we attempted to determine which nicotine levels provide desired nicotine intake with a minimum of physiologic and biochemical consequences. Twelve prescreened subjects were divided into two study groups and supplied with cigarettes that varied in nicotine delivery. Both groups were initially monitored while smoking their usual cigarette. At the following visit, smokers in group 1 received incremental increases and smokers in group 2 received incremental decreases in nicotine levels in assigned cigarettes. All subjects were monitored upon first exposure, after 1 week of acclimatization to each experimental cigarette, and upon return to their usual brands. Subjects in both groups were unable to compensate fully for their nicotine uptake from the lowest nicotine cigarette. In subjects in group 1, new nicotine baselines began to develop after 1 week of acclimatization to cigarettes containing 0.9 and 1.3 mg nicotine. New baseline nicotine levels were also noted in subjects receiving decreases in nicotine (group 2) after smoking the cigarette containing 1.3 mg nicotine for 1 week. Carboxyhemoglobin concentrations did not differ from those measured after the usual-brand cigarettes. Plasma cotinine concentrations increased as nicotine content per cigarette increased, except when subjects smoked a 1.3 mg nicotine cigarette. Plasma thiocyanate levels did not vary in either group. Systolic and diastolic blood pressures were generally not different from control values.

A new ELISA kit for measuring urinary 2-hydroxyestrone, 16alpha-hydroxyestrone, and their ratio: reproducibility, validity, and assay performance after freeze-thaw cycling and preservation by boric acid.

There is considerable controversy regarding the role of estrogen metabolites in breast cancer risk, fueled in part by the development of a rapid ELISA that is suitable for large scale investigations. An earlier version of the ELISA could detect values of the 2-hydroxyestrone (2-OHE1) and 16alpha-hydroxyestrone (16alpha-OHE1) metabolites as low as 2 ng/ml and produce consistent results in premenopausal urines. However, reproducibility was problematic in postmenopausal urines where concentrations of these compounds are much lower. In response to our concern, a new ELISA was developed with a sensitivity of 0.625 ng/ml, which we evaluated using the same pre- and postmenopausal urine samples analyzed in the earlier ELISA. In this report, we present findings on the new kit with regard to reproducibility of the 2-OHE1 and 16alpha-OHE1 measurements, comparability of results with gas chromatography-mass spectroscopy values, and with regard to the stability of the metabolites after repeated freeze-thaw cycles and after preservation by boric acid. For the most part, we found the new ELISA to be reproducible, with assay coefficients of variation ranging from 10 to 20%, and intraclass correlation coefficients (ICCs) ranging from 80 to 95% in both the pre- and postmenopausal urines. ELISA results for 16alpha-OHE1 differed from 1 day (i.e., batch) to the next, and the absolute values of the metabolites obtained by the ELISA were consistently lower than but well correlated with those obtained by gas chromatography-mass spectroscopy. Values of the 2-OHE1:16alpha-OHE1 ratio also differed between the methods, but because the range of values was not large, the magnitude of these differences was not as great. For the ratio, the correlation between methods was excellent, and the ICCs were high for both groups of women. After preservation by boric acid, values of the ratio varied according to acid concentration but not in a linear fashion. Ratio values were similar in urine samples exposed to four different freeze-thaw cycle treatments, although values for all treatments were consistently lower in one batch. Because batch-to-batch variability was not negligible, it is advisable that matched cases and controls be analyzed in the same batch. Provided this is done, the relatively low assay coefficient of variation and high ICC demonstrate that the new ELISA kit can reliably measure the 2-OHE1:16alpha-OHE1 ratio and detect small case-control differences in large population-based studies, where rapid and relatively easy laboratory methods are critical.

Reproducibility of plasma and urinary sex hormone levels in premenopausal women over a one-year period.

Although endogenous sex steroid hormones in premenopausal women may be associated with the risk of breast cancer and other illnesses, direct evidence to support this hypothesis is limited in large part by methodological issues in the conduct of relevant studies. One major unresolved issue is whether a single blood sample (such as is available in most epidemiological studies), collected in a specific phase of the menstrual cycle, reflects long-term levels in that phase. To address this issue, two sets of blood and urine samples were obtained from 87 premenopausal women over a 1-year period in both the follicular and luteal phases. Plasma estradiol, estrone, and estrone sulfate were measured in the blood samples obtained in both phases, whereas progesterone and urinary 2- and 16a-hydroxyestrone were measured in luteal-phase samples only. For all of the women combined, intraclass correlation coefficients (ICCs) ranged, with one exception, from 0.52 to 0.71 for the plasma estrogens and the urinary estrogen metabolites. The sole exception was for estradiol in the luteal phase (ICC = 0.19); inclusion of only women who were ovulatory in both cycles and who collected each sample 4-10 days before their next period resulted in a substantially higher ICC for estradiol in the luteal phase (ICC = 0.62; 95% confidence interval, 0.43-0.78). These data indicate that, for several plasma and urinary sex hormones, a single follicular- or luteal-phase measurement in premenopausal women is reasonably representative of hormone levels in that phase for at least a 1-year period.

Urinary estrogen metabolites and mammographic parenchymal patterns in postmenopausal women.

It has been hypothesized that women who metabolize their endogenous estrogens predominantly via 16(alpha)-hydroxylation rather than via 2-hydroxylation and, as a result, have a low ratio of 2-hydroxyestrone (2-OHE1):16(alpha)-hydroxyestrone (16(alpha)-OHE1) are at an increased risk of breast cancer. Epidemiological evidence in support of this hypothesis is scarce and mostly based on measurements made after the onset of the disease. To gain insight into the role of these metabolites in the etiology of breast cancer, we assessed their relationship with high-density Wolfe mammographic parenchymal patterns (P2/DY), a recognized indicator of risk of this tumor. The study was nested within a large cross-sectional survey on determinants of mammographic patterns carried out in a population-based breast screening program in Northern Greece. Urinary levels of 2-OHE1 and 16(alpha)-OHE1 were measured in a random sample of 70 postmenopausal women with P2/DY mammographic patterns and in a random sample of 70 women with N1 mammographic patterns, individually matched to the P2/DY women on year of birth, years since menopause and date of urine collection. Women with a P2/DY pattern had, on average, 58% higher levels of 2-OHE1 (P = 0.002) and 15% higher levels of 16(alpha)-OHE1 (P = 0.37) than those with an N1 pattern. The ratio of 2-OHE1:16(alpha)-OHE1 was 35% higher (P = 0.005) in women with a P2/DY pattern. Women in the highest one-third of this ratio were six times more likely to have a P2/DY pattern than those in the lowest one-third after adjusting for potential confounders (prevalence odds ratio, 6.2; 95% CI, 1.7-22.9; test for linear trend, P = 0.002). These findings seem to suggest that a high, rather than a low, 2-OHE1:16(alpha)-OHE1 ratio may be associated with an increase in breast cancer risk at postmenopausal ages, unless the pathway through which estrogen metabolites may affect breast cancer risk is unrelated to mammographic parenchymal patterns.

2-hydroxyestrone: the 'good' estrogen.

The issue of the role of 2-hydroxyestrone (2-OHE1) in breast cancer has been the subject of considerable controversy as to whether it is carcinogenic or anticarcinogenic. The expanding data base outlined below is most consistent with the conclusion that 2-OHE1 is anticarcinogenic. In every experimental model in which 2-hydroxylation was increased, protection against tumors was achieved. Correspondingly, when 2-hydroxylation was decreased, an increase in cancer risk was observed. Even more dramatically, in the case of laryngeal papillomas induction of 2-hydroxylation with indole-3-carbinol (I3C) has resulted in inhibition of tumor growth during the time that the patients continue to take 13C or vegetables rich in this compound.

Effects of pesticides on the ratio of 16 alpha/2-hydroxyestrone: a biologic marker of breast cancer risk.

Xenobiotic estrogens are external compounds with estrogenic activity that may thereby affect the risk of breast cancer. This paper describes a mechanism by which xeno-estrogens may affect the development of breast cancer. Estradiol metabolism proceeds by hydroxylation at one of two mutually exclusive sites at C-2 and C-16 alpha. The catechol pathway yields the weakly estrogenic 2-hydroxyestrone (2-OHE1), which inhibits breast cell proliferation. In contrast, the alternative pathway yields the genotoxic 16 alpha-hydroxyestrone (16 alpha-OHE1), which enhances breast cell growth, increases unscheduled DNA synthesis, and oncogene and virus expression, and increases anchorage-independent growth. Using a radiometric assay that measures the relative formation of 16 alpha-OHE1 versus 2-OHE1 from specifically tritiated estradiol in (ER+) MCF-7 cells, we compared the ratio of 16 alpha-OHE1/2-OHE1 observed after treatment with the known rodent carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) with the ratios after treatment with DDT, atrazine, gamma-benzene hexachloride, kepone, coplanar PCBs, endosulfans I and II, linoleic and eicosapentenoic acids, and indole-3-carbinol (I3C). These pesticides significantly increase the ratio of 16 alpha-OHE1/2-OHE1 metabolites to values comparable to or greater than those observed after DMBA. In contrast, the antitumor agent I3C increased 2-OHE1 formation and yielded ratios that are 1/3 of those found in unexposed control cells and 1/10th of those found in DMBA-treated cells. Thus the ratio of 16 alpha-OHE1/2-OHE1 may provide a marker for the risk of breast cancer. Assays of this ratio, which can be measured in spot urines, may prove useful for a variety of in vitro and in vivo studies bearing on breast cancer risk.

Approaches for assessing health risks from complex mixtures in indoor air: a panel overview.

Critical to a more definitive human health assessment of the potential health risks from exposure to complex mixtures in indoor air is the need for a more definitive clinical measure and etiology of the health effects of complex mixtures. This panel overview highlights six of the eight presentations of the conference panel discussion and features a number of the major topical areas of indoor air concern. W. G. Meggs assessed clinical research priorities with primary focus on the role of volatile organic chemicals in human health, recognizing the areas where definitive data are lacking. By recognizing many types of chemical sensitivity, it may be possible to design studies that can illuminate the mechanisms by which chemical exposure may cause disease. The critically important topic of multiple chemical sensitivity was discussed by N. A. Ashford, who identified four high risk groups and defined the demographics of these groups. P. A. Schulte addressed the issue of biological markers of susceptibility with specific considerations of both methodological and societal aspects that may be operative in the ability to detect innate or inborne differences between individuals and populations. Three case studies were reviewed. H. Anderson discussed the past and present priorities from a public health perspective, focusing on those issues dealing with exposures to environmental tobacco smoke and formaldehyde off-gassing from materials used in mobile home construction. J. J. Osborne described several case studies involving wood smoke exposure to children, with emphasis on the significantly greater occurrence of chronic respiratory symptoms and acute chest illness for children from homes heated with woodburning stoves.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantifying estrogen metabolism: an evaluation of the reproducibility and validity of enzyme immunoassays for 2-hydroxyestrone and 16alpha-hydroxyestrone in urine.

Rapid and simple enzyme immunoassays (EIAs) were recently developed to measure 2-hydroxyestrone and 16alpha-hydroxyestrone in unextracted urine. The balance between these competing estrogen metabolism pathways may serve as a biomarker of breast cancer risk. Before testing these assays in epidemiologic studies, we evaluated their reproducibility, and validity relative to gas chromatography-mass spectroscopy (GC-MS). Overnight 12-hr urine collections from five midfollicular premenopausal women, five midluteal premenopausal women, and five postmenopausal women were aliquoted and stored at -70 degrees C. Two aliquots from each woman were assayed with the EIAs in a random, blinded order, monthly over 4 months and 1 year later. Reproducibility over 4 months was good for both metabolites in premenopausal women (coefficient of variation = 8-14%) and satisfactory in postmenopausal women (approximately 19%). Reproducibility over 12 months remained good in premenopausal women, but was poor in postmenopausal women, with mean readings increasing 50 to 100%. Wide variation in estrogen metabolite levels enabled a single EIA measurement to characterize individual differences among premenopausal women in midfollicular (intraclass correlation coefficient = 98-99%) and midluteal phase (85-91%). A narrower range in metabolite levels among postmenopausal women reduced discrimination (78-82%). The correlation between EIA and GC-MS measurement was excellent for both metabolites (r>0.9), except for 2-hydroxyestrone in postmenopausal women (r=0.6). Analysis of absolute agreement suggested that both EIAs were less sensitive than GC-MS, and each detected nonspecific background. The low concentration of estrogen metabolites in urine from postmenopausal women may explain the problems with reproducibility and validity in this menstrual group. Accordingly, more sensitive EIAs have been developed and are now being evaluated.

Influence of indole carbinols and growth hormone on the metabolism of 4-androstenedione by rat liver microsomes.

The effect of indole-3-carbinol (IC), an anticarcinogen present in cruciferous vegetables, to alter the metabolism of 4-androstenedione (AD) by female rat liver microsomes was investigated and compared to that of its main gastric conversion product, diindolylmethane (DIM) as well as other specific cytochrome P450 inducers. DIM was a more potent inducer of the hydroxylase which converts androsterone to its 6 beta-hydroxylated derivative 3 alpha, 6 beta-dihydroxy-5 alpha-androstan-17-one (A) than IC after either oral or intraperitoneal administration and was also a better in vitro inhibitor. Isosafrole (ISF), which like IC and DIM, induces CYP1A2 as well as gestodene, were powerful inhibitors of the in vitro reaction. Naringenin produced only a weak inhibitory effect while 3-methylcholanthrene was inactive. SKF-525A, a prototypic hydroxylase inhibitor, or 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androst-1-ene-3-one which inhibits steroid 5 alpha-reductase, also decreased the formation of A from AD by liver microsomes. The infusion of human growth hormone by osmotic minipump, which feminizes hepatic steroid metabolism, increased the ability of male rat liver microsomes to convert AD to A and to respond to induction by IC. The identity of A, the main polar derivative of AD, induced by IC, DIM and ISF, was tentatively assigned by a combination of GC-MS and results from metabolic studies with intermediates in the pathway leading to its formation. It is proposed that the protective role of indole carbinols against mammary carcinoma due to decreased formation of 16 alpha-hydroxyestrone from estrone may be further enhanced by the diminished availability of AD for aromatization to estrone.

Indole-3-carbinol. A novel approach to breast cancer prevention.

The results show that all of the carcinogens, oncogenes, and tumor-associated viruses that we have studied profoundly affect the extent of 2- and 16 alpha-hydroxylation in a prorisk direction. All of the dietary and biological responses associated with increased cancer risk decrease 2-hydroxylation and increase 16 alpha-hydroxylation. Remarkably, although PAHs are reported to induce P450-1A1, we have found them to decrease 2-hydroxylation. Finally, using indole-3-carbinol to induce 2-hydroxylation results in the chemoprevention of mammary tumors in rodents and recurrences of laryngeal papillomas in humans. Also correlating with these studies in HPV is the decrease in the C-2/C-16 alpha metabolite ratio observed in women with CIN relative to control subjects. The greatest decrease was observed in women with the most severe form, CIN3 (Figure 23). These findings are under further investigation.

Multifunctional aspects of the action of indole-3-carbinol as an antitumor agent.

Previous studies from this laboratory have suggested that 2-hydroxyestrone is protective against breast cancer, whereas the other principal metabolite, 16 alpha-hydroxyestrone, and the lesser metabolite quantitatively, 4-hydroxyestrone, are potent carcinogens. Attempts to directly decrease the formation of the 16-hydroxylated metabolite were either unsuccessful or required such high levels of the therapeutic agent as to be impractical. On the other hand the concentration of the protective metabolite, 2-hydroxyestrone, proved to be readily modulated by a variety of agents, both in the direction of increased protection and the opposite direction, increased risk by a variety of agents and activities. We have focussed our attention on indole-3-carbinol, a compound found in cruciferous vegetables, and its further metabolites in the body, diindolylmethane (DIM) and indolylcarbazole (ICZ), because of its relative safety and multifaceted activities. It has been shown that it induces CyP4501A1, increasing 2-hydroxylation of estrogens, leading to the protective 2-OHE1, and also decreases CyP1B1 sharply, inhibiting 4-hydroxylation of estradiol, thereby decreasing the formation of the carcinogenic 4-OHE1. In addition to these indirect effects as a result of altered estrogen metabolism, indole-3-carbinol has been shown to have direct effects on apoptosis and cyclin D, resulting in blockage of the cell cycle. In addition to its antitumor activity in animals, it has also been shown to be effective against HPV-mediated tumors in human patients. All of these responses make the study of its behavior as a therapeutic agent of considerable interest.

Monoclonal antibody-based enzyme immunoassay for simultaneous quantitation of 2- and 16 alpha-hydroxyestrone in urine.

Alterations in the metabolism of estrogen have been implicated as an important factor in the etiology of diseases such as gynecological cancers and lupus erythematosus. The major metabolites of estradiol are hydroxylated at the C-2 or C-16 alpha position yielding products with estrogen antagonist and agonist activities, respectively. A sensitive and specific immunodiagnostic assay to determine the balance between these competing pathways might serve as a routine biomarker for management of estrogen-related diseases. We describe here the generation of high affinity, specific murine monoclonal antibodies to 2-hydroxyesterone and 16 alpha-hydroxyestrone by high efficiency fusion protocols. With these antibodies, we have developed a rapid and simple enzyme immunoassay (EIA) kit for the simultaneous quantitation of 2- and 16 alpha-hydroxyestrone in unextracted urine. Initial validation studies established that urinary metabolite 2- and 16 alpha-hydroxyestrone concentrations found by the EIA correlate well with values found by gas chromatography-mass spectroscopy. Preliminary studies with the EIA kit found total recovery of metabolites from spiked urine samples. The EIA inter- and intra-assay coefficients of variation for 2-hydroxyestrone and 16 alpha-hydroxyestrone and the ratio of 2-hydroxyesterone to 16 alpha-hydroxyestrone with the current EIA kit were consistently less than 9%. This kit, designated ESTRAMET 2/16 may provide an important new tool for research in estrogen-related diseases.

Application of an improved ELISA assay to the analysis of urinary estrogen metabolites.

Work from Strang and other laboratories has established that the 2-/16 alpha-hydroxyestrone ratio is inversely correlated with the risk for breast and cervical cancer. In order to measure these metabolites in urine samples, it is essential to have an assay for these compounds that is both sensitive and reproducible. The present paper describes such an ELISA assay, which overcomes problems that existed in prior approaches to measuring these compounds. The new ELISA procedure supplies greater sensitivity and reproducibility than earlier assay procedures. The ELISA assay has also been found to correlate well with the GC-MS procedure of Adlercreutz.

Catechol estrogen production in rat microsomes after treatment with indole-3-carbinol, ascorbigen, or beta-naphthaflavone: a comparison of stable isotope dilution gas chromatography-mass spectrometry and radiometric methods.

Compounds like indole-3-carbinol (I3C) have been shown to increase catechol estrogen formation and reduce mammary tumor incidence in mice. These compounds may exert a protective effect for breast cancer development by decreasing the overall estrogen pool available for the formation of 16 alpha-hydroxyestrone (16 alpha-OHE1), a metabolite that retains significant estrogenic activity, may be mutagenic and could represent a potential carcinogenic intermediate of estradiol degradation. I3C and ascorbigen originate from the breakdown of glucobrassicin. We have compared the inductive effects of I3C with ascorbigen and beta-naphthaflavone (Bnf) in microsomes from rats pretreated with these compounds using isotope dilution GC-MS and a radiometric method. Incubated microsomes from rats pretreated with I3C and ascorbigen yielded high levels of 2-hydroxyestradiol (2-OHE2) that were comparable to levels induced by Bnf and were significantly above control group levels (p < 0.005). Absolute values determined by the radiometric method were approximately 40% lower than 2-OHE2 concentrations determined by GC-MS, although the relative changes in each group were the same. These differences may be attributed to the radiolabel becoming trapped in microsomal intermediates in the sequence leading to tritium entering the aqueous compartment. Both ascorbigen- and Bnf-treated animals exhibited significant increases in 2-hydroxyestrone (2-OHE1) (p < 0.05). The ability of ascorbigen to induce estradiol C-2 hydroxylation has not been previously reported. Based on these data, we speculate that ascorbigen will act as an anticarcinogenic agent and will inhibit or reduce the incidence of mammary tumor formation.

Estrone and estradiol metabolism in vivo in human breast cysts.

Fibrocystic disease of the breast manifesting palpable cysts express breast cyst fluids frequently containing estrogen sulfates at concentrations far exceeding those found in sera of the patient. The study explored the potential of the breast cyst to synthesize some of these estrogen sulfates. Deuterated estrone and estradiol were synthesized and either (estradiol, 4 cases or estrone, 2 cases) was injected into a cyst. The cyst was aspirated at approximately 0, 4 and 8 h, the target being 1 ml, 50% and complete aspiration respectively. Metabolites were purified sequentially by ether extraction, enzymatic hydrolysis of estrogen conjugates, chromatography on Sephadex LH 20 and identified by gas chromatography linked to mass spectrometry. The unconjugated fraction isolated from the ether extract was subjected to the same purification and detection scheme. Among the conjugates, deuterated estrone sulfate was the major metabolite of either precursor in all studies, while estradiol sulfate was not detected in any of the 6 experiments. The sulfate fractions also yielded traces of 16alpha-hydroxyestrone (2 studies), 4-hydroxyestrone (4 studies) and 2-hydroxyestrone (1 study). In the unconjugated fraction, one study with deuterated estradiol, 4- hydroxyestrone was obtained. In one study with deuterated estrone, traces of 2-hydroxyestrone and 16alpha- hydroxyestrone were obtained. These novel data are significant because patients with fibrocystic disease are at slightly elevated risk for developing breast cancer and 16alpha-hydroxyestrone and 4- hydroxyestrone are reported carcinogens.

Urinary markers of estrogen metabolism 2- and 16 alpha-hydroxylation in premenopausal women.

There is considerable scientific interest in whether measurement of the major estrogen metabolites 2- and 16 alpha-hydroxyestrone will shed light on the role of estrogen in the risk of breast cancer. These have been difficult to measure in large numbers because of the need for radiolabeled tracers, but a new assay is able to utilize spot urine samples. The main objective of this study was to assess the reliability of a newly developed enzyme immunoassay (EIA) for the measurement of 2- and 16 alpha-hydroxyestrone in urine samples collected from a large group of healthy premenopausal women enrolled in a clinical trial A secondary objective was to assess the impact of several factors such as body weight on the urinary estrogen metabolite ratios. The study cohort included 174 women aged 44-50, who were enrolled in the Cardiovascular Risk Factors and Menopause Trial, also referred to as the Women's Healthy Lifestyle Project (WHLP), an ongoing 5-year clinical trial of 535 premenopausal women randomized either to an intensive dietary life-style intervention group or to an assessment-only control group. Measurements of 2- and 16 alpha-hydroxyestrone showed a high intraclass correlation for blind duplicate urine samples (R = 0.94 and R = 0.80), cross-sectionally and over time (R = 0.79 and R = 0.62), in this population of healthy premenopausal women. The intervention diet (of 25% of total calories from fat) did not appear to influence the estrogen metabolite ratio. This new estrogen metabolite EIA demonstrates good reliability and thus may be appropriate for use in large epidemiologic studies of estrogen-related diseases. There was no relation between dietary fat reduction, weight loss, and increased exercise and change in the ratio among premenopausal women in this study.

Estrogen metabolism and laryngeal papillomatosis: a pilot study on dietary prevention.

Evidence exists that estrogen metabolism has a role in the pathogenesis of recurrent respiratory papillomatosis (RRP). This disease has a papillomavirus etiology and is characterized by recurrent benign tumors with a significant propensity to become malignant. We have measured the systemic transformation of estrogen using an enzyme-linked-immunoassay to measure estrogen metabolites in the urine of patients with RRP and compared these ratios to the severity of RRP, a measure of the average growth rate of papillomas. Our results show an inverse relationship between the ratio of C-2 to C-16 alpha-hydroxylated estrogens and the severity of RRP. In a pilot study, patients consumed cruciferous vegetables to induce C-2-hydroxylation. In this group of patients, an increase in the ratio correlated with an improvement in RRP. The ratio did not change in a subset of these patients, and their RRP did not improve. Regardless, the ratio correlated with severity of their RRP.

Anti-estrogenic activities of indole-3-carbinol in cervical cells: implication for prevention of cervical cancer.

BACKGROUND: Cervical cancer constitutes the second most common cancer in women. Estrogen promotes development of cervical cancer in cells infected with high risk human papillomaviruses (HPVs). We asked whether the phytochemical indole-3-carbinol (I3C) has anti-estrogenic activities in cervical cells with the goal of preventing cancer in HPV infected cells. MATERIALS AND METHODS: Using the cervical cancer cell line CaSki, we evaluated expression of HPV and cytochrome p450 (CYP) enzymes by Northern, RNase protection or quantitative RT-PCR. I3C binding to estrogen receptor was measured by competition with estradiol. Estrogen metabolites were measured by gas chromarography-mass spectrometry (GC-MS). RESULTS: Estradiol increased expression of HPV oncogenes whereas I3C and the estrogen metabolite 2-hydroxyestrone (2-OHE) abrogated the estrogen-increased expression of HPV oncogenes. Both I3C and 2-OHE competed with estradiol for estrogen receptor binding. I3C enhanced gene expression of CYP enzymes responsible for 2-hydroxylation of estrogen, and induced the formation of 2-OHE. CONCLUSION: I3C has anti-estrogenic activities which should prevent cancer in cervical cells.

Kinetic parameters of L-[125I]triiodothyronine degradation in rats pretreated with polyhalogenated biphenyls.

These studies were designed to elucidate the effects on thyroid function and thyroid-hormone activity of the long-term administration of low doses of four polyhalogenated aromatic compounds. The compounds studied were the polychlorinated biphenyls (PCBs) Aroclor 1254 and Aroclor 1242, and the polybrominated biphenyls (PBBs) hexabromobiphenyl and octabromobiphenyl. Groups of eight female Sprague-Dawley rats, specified pathogen free, were fed a diet containing 50 ppm of one of the polyhalogenated biphenyls or control diet for 7 months. Significant effects on serum triiodothyronine (T3) were observed in the group given Aroclor 1254. Analysis of kinetic data revealed a decrease in T3 degradation rate and an increase of biological half-life after long-term exposure to Aroclor 1254. The T3 distribution space was increased in both groups treated with PCB, suggesting that PCB intoxication may open additional fluid pools to T3, possibly because of cell damage. Analysis of values for the same parameters for rats treated with PBBs showed less marked effects. The results of this study indicate that PCBs exert a direct effect on the thyroid gland and that the rate of synthesis of T3 may be reduced, and suggest that the mechanism of thyroid-hormone synthesis may be impaired.