Environmental PCB exposure and risk of endometriosis.

BACKGROUND: Hormonally active environmental agents have recently been associated with the development of endometriosis. METHODS: We undertook a study to assess the relationship between endometriosis, an estrogen-dependent gynaecological disease, and 62 individual polychlorinated biphenyl (PCBs) congeners. We enrolled 84 eligible women aged 18-40 years undergoing laparoscopy for study, which included an interview and blood specimen (n=79; 94%). Thirty-two women had visually confirmed endometriosis at laparoscopy while 52 did not. Blood specimens were run in batches of 14 including four quality control samples for toxicological analysis. Each PCB congener was adjusted for recovery; batch-specific reagent blanks were subtracted. All PCB concentrations were log transformed and expressed in ng/g serum first as a sum and then as tertiles by purported estrogenic or anti-estrogenic activity of PCB congeners. RESULTS: Using unconditional logistic regression analysis, a significantly elevated odds ratio (OR) was observed for women in the third tertile of anti-estrogenic PCBs [OR 3.77; 95% confidence interval (CI) 1.12-12.68]. Risk remained elevated after controlling for gravidity, current cigarette smoking and serum lipids (OR 3.30; 95% CI 0.87-12.46). CONCLUSIONS: These data suggest that anti-estrogenic PCBs may be associated with the development of endometriosis.

A sensitive method for determining levels of [-]-2,5,-dimethoxy-4-methylamphetamine in the brain tissue.

INTRODUCTION: Indolamine and phenethylamine hallucinogens are drugs of abuse and, as well, mimic some aspects of idiopathic psychosis. To assist in investigating the mechanisms of action of (-)2,5-dimethoxy4-methylamphetamine ([-]-DOM), a member of the phenethylamine class of serotonergic hallucinogens, a sensitive and precise method for determining its levels in the brain tissue is required. METHODS: We now describe a method for determining nanogram quantities of [-]-DOM in the rat brain tissue using D-amphetamine as an intemal standard. The method employs solvent extraction with toluene and derivatization with trifluoroacetic acid anhydride (TFAA) followed by analysis using gas chromatography-mass spectrometry (GS-MS) in the selective ion monitoring (SIM) mode. RESULTS: With SIM detection, our overall recoveries were greater than 90%. The method was reliable in terms of within-day and between-day precision, accuracy, and linearity. The procedure was applied to animal subjects to determine the in vivo [-]-DOM brain levels following intraperitoneal (ip) administration. Our findings indicate that peak levels of [-]-DOM do not coincide with the 75-min pretreatment time established by drug-induced stimulus control. DISCUSSION: This study demonstrates a sensitive and precise analytical method for the determination of [-]-DOM levels in the rat brain following systemic administration of behaviorally relevant doses.

Parental consumption of contaminated sport fish from Lake Ontario and predicted fecundability.

Wildlife studies suggest that consumption of contaminated fish from the Great Lakes may expose humans to polychlorinated biphenyls and persistent chlorinated pesticides. To assess whether time to pregnancy or fecundability is affected, we conducted a telephone survey in 1993 with female members of the New York State Angler Cohort Study who were considering pregnancy between 1991 and 1994 (N = 2,445). Among the 1,234 (50%) women who became pregnant, 895 (73%) had a known time to pregnancy. Upon enrollment into the cohort in 1991, both partners reported duration and frequency of Lake Ontario sport fish consumption. We estimated lifetime exposure to polychlorinated biphenyls from recent consumption and used a discrete-time analog of Cox proportional hazards analysis to estimate conditional fecundability ratios and 95% confidence intervals (CIs) for fish consumption among couples with complete exposure data who discontinued birth control to become pregnant (N = 575). Maternal consumption of fish for 3-6 years was associated with reduced fecundability (fecundability ratio = 0.75; 95% CI = 0.59-0.91), as was more than a monthly fish meal in 1991 (fecundability ratio = 0.73; 95% CI = 0.54-0.98). Our findings suggest that maternal but not paternal consumption of contaminated fish may reduce fecundability among couples attempting pregnancy.

Paternal Lake Ontario fish consumption and risk of conception delay, New York State Angler Cohort.

The aquatic ecosystems of the Great Lakes are contaminated with a variety of compounds, some of which are considered reproductive toxicants. Few studies of paternal fish consumption and reproductive endpoints have been undertaken and serve as the impetus for study. Standardized telephone interviews were conducted with 2445 female members of the New York State Angler Cohort (82% response) to update reproductive profiles and to ascertain specific information on time-to-pregnancy (TTP). The study sample includes women with a known TTP and paternal fish consumption data (n=785). Conception delay was defined as more than 12 cycles of unprotected intercourse to achieve pregnancy. Paternal fish consumption was assessed by three measures: frequency of Lake Ontario sport fish meals in 1991, numbers of years eating fish, and estimated PCB exposure from fish consumption. Adjusted ORs for number of fish meals, based on logistic regression, ranged from 0.69 to 0.80; from 0.61 to 0.82 for number of years eating fish; and from 0.44 to 1.14 for quartiles of estimated PCB exposure from fish consumption. All confidence intervals included one. These findings suggest that, based on paternal self-reports, Lake Ontario fish consumption does not increase the risk of conception delay.

Relation of Lake Ontario fish consumption, lifetime lactation, and parity to breast milk polychlorobiphenyl and pesticide concentrations.

Lactating female members and spouses of male members of the New York State Angler Cohort who agreed to provide breast milk samples were the subjects of this study. Questionnaires were provided to participants focusing on Lake Ontario fish consumption, reproductive history, and lactation history. Milk samples were analyzed for 77 polychlorinated biphenyls (PCB) congeners, 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE), a metabolite of dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene (HCB), and 1,1a,2,2,3,3a, 4,5,5,5a,5b,6-dodecachlorooctahydro-1,3, 4-methano-1H-cyclobuta[cd]pentalene (Mirex). The percentage of samples with quantifiable levels, above the limit of detection (LOD), varied among the individual congeners from 10 to 100%. Nine PCB congeners (designated by their IUPAC No.) and DDE were found in all of the 100 samples analyzed. These include the following, in decreasing order of concentration: DDE>153>138>180>118>187>188>177>200. Total PCB concentrations were estimated by taking the sum of the concentrations of all PCB congeners (up to 77 congeners) above their respective LOD in a given sample. PCB concentrations increased with increasing concentration of milk lipid. Lipid adjusted PCB concentrations increased as a function of maternal age. PCB congener profiles in milk favored the higher chlorinated congeners, with the four highest congeners having 5 to 7 chlorine atoms. Fish eaters had a significantly higher level of several major PCB congeners with congeners 153 and 138 being 1.36 and 1.34 times higher, respectively. PCB and DDE concentrations, expressed on a lipid basis, varied inversely with parity. The total number of months of lifetime lactation varied inversely with the total PCB concentration in breast milk. A similar relationship was evident for DDE. These data are of use for risk assessment in estimating the relative exposure to these environmental contaminants in breast fed infants whose mothers consumed contaminated Lake Ontario fish.

Comparison of PCB congeners and pesticide levels between serum and milk from lactating women.

Samples of blood and milk were obtained from lactating women participating in the New York State Angler study. A total of seven women gave one blood and one milk sample at time intervals between blood and milk collection different for each woman. The time between samples varied from 3 to 318 days. One subject provided a second milk sample 219 days after the first milk sample. The samples were analyzed for 69 PCB congeners, DDE (a metabolite of DDT), Mirex, and hexachlorobenzene (HCB). Lipid content was determined by gravimetric analysis. The congener profiles in serum and milk were similar for each individual but different among all subjects. The sum of the concentrations of the congeners present above the limit of detection was used to estimate the total PCB concentration that was in the range of 2.6 to 5.8 ng/g of serum and 3.5 to 14.1 ng/g of milk. The ratio of serum to milk concentrations varied from 0.18 to 1.66 with a mean of 0.65+/-0.49 showing no consistency among individuals prior to adjusting the data for lipid content. The total PCB levels normalized for lipid content were 320-728 ng/g of serum lipid and 239-428 ng/g of milk lipid. The range of the lipid adjusted serum/milk ratio was 1.1 to 2.8 and the mean+/-SD serum/milk ratio was 1.9+/-0.5. The ranges of lipid adjusted serum concentration of DDE, HCB, and Mirex were 95 to 591, 8 to 48, and 3 to 29 ng/g lipid, respectively. The ranges of lipid adjusted milk concentration of DDE, HCB, and Mirex were 90 to 577, 11 to 22, and 1 to 10 ng/g lipid, respectively. For DDE, HCB, and Mirex, the means of the individual lipid adjusted serum to milk ratios were 1.5+/-0.7, 2.5+/-1.5, and 5. 3+/-4.6, respectively. Considerable differences were found among lipid adjusted concentrations of these environmental pollutants in serum and milk samples from the same individual. This suggests that body burden estimates in lactating women using different matrices may not be equivalent even when lipid adjusted values are used.

Polychlorinated biphenyls, cytochrome P4501A1 polymorphism, and postmenopausal breast cancer risk.

In experimental systems, polychlorinated biphenyls (PCBs) induce cytochrome P4501A1 (CYP1A1), which is involved in metabolism of steroid hormones and polycyclic aromatic hydrocarbons in humans. A genetic polymorphism coding for a valine to isoleucine substitution in exon 7 has been associated with lung cancer risk in Japanese populations. In a previous study, we found no association between CYP1A1 genotype and breast cancer risk. However, we were interested in determining whether genotype would relate to risk when PCB body burden was taken into account. In a subset of a case-control study in western New York, 154 postmenopausal women with incident, primary, histologically confirmed postmenopausal breast cancer and 192 community controls were interviewed and underwent phlebotomy. Serum levels of 56 PCB peaks were determined by high resolution gas chromatography with electron capture. PCR-RFLP analyses of the CYP1A1 polymorphism were performed. Unconditional logistic regression was used to compute adjusted odds ratios and 95% confidence intervals. Among women with serum PCB levels above the median of the distribution in the control group, there was increased risk of breast cancer associated with the presence of at least one valine allele, compared with women who were homozygous for the isoleucine alleles (odds ratio, 2.93; 95% confidence interval, 1.17-7.36). Among women with low PCB body burden, no association between CYP1A1 genotype and breast cancer risk was observed. Adjustment for serum lipids and body mass index did not affect the magnitude of the observed associations. PCB body burden may modify the effect of the polymorphism on postmenopausal breast cancer risk through increased CYP1A1 enzyme induction or by activation by specific PCB congeners. These results should be considered preliminary, pending replication by other studies.

An evaluation of proposed frameworks for grouping polychlorinated biphenyl (PCB) congener data into meaningful analytic units.

BACKGROUND: Polychlorinated biphenyls (PCBs) have been associated with a variety of health outcomes. Enhanced laboratory techniques can provide a relatively large number of individual PCB congeners for investigation. However, to date there are no established frameworks for grouping a large number of PCB congeners into meaningful analytic units. METHODS: In a case-control study of serum PCB levels on breast cancer risk, measured levels of 56 PCB congener peaks were available for analysis. We considered several approaches for grouping these compounds based on 1) chlorination, 2) factor analysis, 3) enzyme induction, 4) enzyme induction and occurrence, and 5) enzyme induction, occurrence, and other toxicological aspects. The utility of a framework was based on the mechanism of biologic actions within each framework, lack of collinearity among congener groups, and frequency of detection of PCB congener groups in measured serum levels of 192 healthy postmenopausal women. RESULTS: Most participants had detectable levels for the proposed PCB congeners groups, using degree of chlorination as a grouping framework. In addition, the previously proposed grouping approach based on enzyme induction, occurrence, and other toxicological aspects was an applicable alternative to the crude approach of grouping by degree of chlorination. Grouping these congeners with respect to P450 enzyme induction activity, and the previously proposed framework based on enzyme induction and occurrence, did not fit these data as well, because only a small proportion of participants had detectable levels for the congener groups with the greatest toxicological potential. Statistical grouping did not result in an interpretable and meaningful clustering of these exposures. CONCLUSIONS: In these data, grouping with respect to degree of chlorination and the previously proposed framework based on enzyme induction, occurrence, and other toxicological aspects were the most useful approaches to reducing a large number of PCB congeners into meaningful analytic units. Factors affecting the utility of the proposed grouping frameworks are discussed.

Environmental organochlorine exposure and postmenopausal breast cancer risk.

Environmental exposure to organochlorine compounds has been associated with a potential role in breast cancer etiology, but results from previous investigations yielded inconsistent results. In this case-control study, we examined the effect of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), hexachlorobenzene (HCB), mirex, and several measures of polychlorinated biphenyls (PCBs) on postmenopausal breast cancer risk. The study sample included 154 primary, incident, histologically confirmed, postmenopausal breast cancer cases and 192 postmenopausal community controls. Usual diet, reproductive and medical histories, and other lifestyle information was obtained by an extensive in person interview. Serum levels (ng/g) of DDE, HCB, mirex, and 73 PCB congeners were determined by gas chromatography with electron capture. PCB exposure was examined as total measured PCB levels, total number of detected PCB peaks, and three PCB congener groups. In the total sample, there was no evidence of an adverse effect of serum levels of DDE [odds ratio (OR), 1.34; 95% confidence interval (CI) 0.71-2.55], HCB (OR, 0.81; 95% CI, 0.43-1.53), or mirex (OR, 1.37; 95% CI, 0.78-2.39). Further, higher serum levels of total PCBs (OR, 1.14; 95% CI, 0.61-2.15), moderately chlorinated PCBs (OR, 1.37; 95% CI, 0.73-2.59), more highly chlorinated PCBs (OR, 1.19; 95% CI, 0.60-2.36), or greater number of detected peaks (OR, 1.34; 95% CI, 0.72-2.47) were not associated with increased risk. There was some indication of a modest increase in risk for women with detectable levels of less chlorinated PCBs (OR, 1.66; 95% CI, 1.07-2.88). Among parous women who had never lactated, there was some evidence for increased risk, associated with having detectable levels of mirex (OR, 2.42; 95% CI, 0.98-4.32), higher serum concentrations of total PCBs (OR, 2.87; 95% CI, 1.01-7.29), moderately chlorinated PCBs (OR, 3.57; 95% CI, 1.10-8.60), and greater numbers of detected PCB congeners (OR, 3.31; 95% CI, 1.04-11.3). These results suggest that an increase in risk of postmenopausal breast cancer associated with environmental exposure to PCBs and mirex, if at all present, is restricted to parous women who had never breast-fed an infant. Future studies should consider lactation history of participants, as well as use similar epidemiological and laboratory methodologies, to ensure comparability of results across studies.

Standardization of a method for the routine analysis of polychlorinated biphenyl congeners and selected pesticides in human serum and milk.

A methodology is presented for the routine determination of specific polychlorinated biphenyl (PCB) congeners in serum and milk samples. The procedures include standardized extraction, cleanup and quantitation by high-resolution gas chromatography (GC) and comprehensive quality assurance program to minimize systematic and erratic errors. The analyses of 68 PCB congeners and three pesticides, p,p1-dichloro diphenyl dichloro ethylene (DDE), hexachlorobenzene (HCB), and Mirex, at part-per-billion levels include the addition of surrogate congener standards (IUPAC isomers #46 and #142), extraction with hexane after protein precipitation, cleanup with Florisil, and analysis by GC with capillary column and electron capture detection. Quantitation is based on calibration standards and response factors using isomers #30 and #204 as internal standards. The quality control activities consist of analyses of samples in batches of 6 to 10 simultaneously with quality control (QC) samples. The quality assurance program checks that the procedures are under control by the use of control charts and set the criteria for data acceptability. The detection limits for the congeners and pesticides associated with the analyses of 500 serum samples and of 100 milk samples are reported. In addition, typical profiles of congener distribution in both matrices are illustrated.

The New York Angler Cohort Study: exposure characterization and reproductive and developmental health.

The New York State Angler Study will evaluate the association between past and current consumption of contaminated fish from Lake Ontario and both short- and long-term health effects in a population-based cohort. It will measure fish consumption and reproductive and developmental health among 10,518 male anglers and 6,651 of their wives or partners, as well as among 913 female anglers. To characterize exposure among subgroups of the cohort, further analytical methods were developed and implemented to measure specific polychlorinated biphenyls (PCB) congeners, methylmercury, and other substances in biological samples. Exposure assessment has been completed for a stratified random sample of 321 anglers. In addition, analyses for 79 congeners of PCBs are complete for 177 anglers. A special study of duck and turtle consumers currently is underway. Telephone interviews have been completed with 2,454 of the 2,999 women who planned a pregnancy between 1991 and 1994. The entire cohort of male anglers, partners of male anglers, and female anglers has been submitted for matching with the New York State live birth and fetal death registries to obtain lifetime reproductive histories. A medical record abstraction study will assess perinatal and developmental outcomes among the 3,442 births that occurred between 1986 and 1991. Finally, a study of breast milk from currently lactating women is underway, and 215 breast milk samples have been collected from the planned pregnancy subcohort. Progress on each of the study components is discussed herein.

Extracorporeal regional complexing haemodialysis treatment of acute inorganic mercury intoxication.

A 70-year-old white female presented approximately 24 h after ingesting three 475 mg tablets (1.425 g) of mercuric chloride in a suicide attempt. Acute renal failure necessitated the initiation of haemodialysis approximately 4 d after the ingestion. Treatment with BAL (2,3-dimercaptopropanol) resulted in only small increases in mercury output into dialysate. A new procedure involving the extracorporeal infusion of the chelating agent dimercaptosuccinic acid (DMSA) into the arterial blood line during haemodialysis was initiated. This procedure of Extracorporeal Regional Complexing Haemodialysis (ERCH) had been effective in increasing methylmercury removal in patients poisoned by contaminated grain. The first DMSA-ERCH procedure was performed 6 d after poisoning. There was a dramatic increase in mercury output into the dialysate. During three treatment sessions of 80 min each, 1189 micrograms of mercury were removed from the patient. The dialysed mercury represented the only mercury output since the patient was anuric and not producing faeces. DMSA-ERCH appears to be much more effective than BAL and haemodialysis in the treatment of acute inorganic mercury poisoning. The long interval between poisoning and initiation of treatment probably contributed to the patients ultimate demise, 28 d after poisoning. Efficacy of the DMSA-ERCH procedure for inorganic mercury poisoning is likely to be improved as the interval between exposure and treatment is reduced.

Influence of cefoperazone on ethanol and acetaldehyde metabolism in vitro.

The effect of cefoperazone on ethanol and acetaldehyde metabolism was studied in rat liver homogenates and with a purified aldehyde dehydrogenase. Rat liver homogenates were incubated with ethanol (30 mM) alone or in combination with cefoperazone (15 or 150 micrograms/g liver). Ethanol and acetaldehyde concentrations were determined at 6, 12, 18 and 24 minutes. Cefoperazone added to the incubation medium inhibited ethanol and acetaldehyde metabolism in a concentration-dependent manner. The addition of cefoperazone to rat liver homogenates incubated with acetaldehyde (300 microM), however, did not inhibit acetaldehyde disappearance for a period of 15 minutes. Purified aldehyde dehydrogenase was incubated with 300 microM acetaldehyde. When cefoperazone was added, acetaldehyde disappearance was significantly slower than without cefoperazone. The data indicate that cefoperazone inhibits ethanol metabolism in rat liver homogenates in a concentration-dependent manner. The effect of the antibiotic on acetaldehyde elimination in liver homogenate, however, depends on the concentration of acetaldehyde in the medium. The acetaldehyde dehydrogenase obtained from yeast is inhibited by cefoperazone.

Renal pressor effect of ethanol in the isolated perfused rat kidney.

These experiments were performed to detect changes in renal function produced by acute infusions of small amounts of ethanol into the isolated kidney of the rat. Ethanol was infused for 10 min beginning at 40 min to reach a final concentration of approximately 80 mg/100 ml in the recirculating perfusate. Control kidneys were perfused for 90 min without the addition of ethanol. Control and ethanol infused kidneys were compared with respect to the following measurements: glomerular filtration rate, urine volume, urine protein concentration, pressure and fractional excretion of sodium, chloride, potassium, calcium and magnesium. Ethanol concentration in the perfusate was measured by gas chromatography. The only parameter affected by these concentrations of ethanol was pressure. During the ten min ethanol infusion, the pressure in the system rose significantly (P less than 0.01) from 110 +/- 0.3 to 120 +/- 2.8 mmHg. After the ethanol infusion, the pressure decreased towards pre-ethanol levels at a faster rate than the decrease in ethanol concentration in the perfusate.

Alcohol consumption and systolic blood pressure in the general population.

Survey data was analyzed to examine the relationship between alcohol consumption and systolic blood pressure (SBP) in the general population. Among older people, SBP is higher for heavier drinkers. Among females, SBP is slightly lower for the light drinkers than for abstainers.. These effects are measured with obesity, race, and menopause, use of birth control pills, smoking, and anxiousness held constant. The reasons for these effects are not clear.

Ethanol and indomethacin interactions in motor impairment, hypnosis, and body temperature.

The actions of indomethacin on the effects produced by ethanol were determined in rats and mice by measuring motor coordination (Rotorod test), sleep times, and body temperatures. Mice receiving indomethacin in combination with ethanol slept shorter times than those receiving ethanol alone. The blood and brain ethanol concentrations at time of awakening were significantly higher in the mice receiving the combination of drugs. Ethanol actions on motor impairment in rats and mice and on hypothermia in mice were not altered by pharmacologically relevant doses of indomethacin. The data show that indomethacin antagonizes only some of the observed effects of ethanol. It is suggested that a common mechanism, such as prostaglandin synthesis, is not involved in the interactions of both drugs.

Drug interactions in goldfish tolerant to ethanol and pentobarbital.

The interactions between short- and long-term exposure to ethanol and pentobarbital were characterized in goldfish tolerant to one of these drugs. The effects of ethanol and pentobarbital were measured by the overturn test as the time of onset of the loss of the righting reflex and the corresponding drug concentration in brain of fish immersed in 674 mumol/ml ethanol or 1.21 mumol/ml sodium pentobarbital (challenge solutions). The chronic treatment consisted of 6- or 24-h preexposure to 130 mumol/ml ethanol or 0.06 mumol/ml sodium pentobarbital in Tris buffer solution. Fish preexposed to ethanol for 6 or 24 h or to pentobarbital for 24 h were rendered more tolerant to pentobarbital or ethanol, respectively. Preexposure to pentobarbital for 6 h, however, produced in goldfish the same degree of tolerance to ethanol and to pentobarbital.

Ethanol and diazepam effects on intrauterine growth of the rat.

Four groups of 6 pregnant Long-Evans rats were intubated on days 6, 7, 9, 12, 15, and 18 of gestation with (a) 4 g/kg ethanol (E), (2) 10 mg/kg diazepam (D) plus isocaloric amounts of sucrose, (3) 10 mg/kg diazepam plus 4 g/kg ethanol (DE), and (4) gum arabic suspension plus sucrose solution in isocaloric amount with E (PF). All groups were pair-fed with group DE and had ad libitum access to water. On day 19 there were no differences in maternal weight gain, litter size, fetal weight, and protein content in fetal brain. Fetal brain and placental weight were significantly decreased in E, D, and DE. The decrease in placental weight in DE was significantly higher than in E or D. The concentrations of glutamic acid, alanine, glycine, serine, threonine, leucine, valine, and tyrosine in fetal brains were significantly decreased after E and D, but not different in DE from PF. Diazepam did not potentiate the effects of ethanol. Undernutrition could be a confounding factor in the observed effects.

Indomethacin-ethanol interactions on acute inflammation.

The effect of ethanol on the anti-inflammatory actions of indomethacin was studied using carrageenan-induced edema in the paw of the rat as the test for acute inflammation. The agents were administered 1 hour prior to carrageenan injection, and the volume of the paw was measured immediately and at 3 and 5 hours after carrageenan. Ethanol at 1, 2, and 4 g/kg and indomethacin at 5 and 20 mg/kg significantly inhibited paw edema at 3 and 5 hours. The combination of the various doses of ethanol and indomethacin produced the same degree of inhibition as ethanol alone and significantly higher inhibition than indomethacin alone. The concentration of indomethacin in the inflammed paw was significantly higher than in the other paw in animals receiving 20 mg/kg indomethacin alone and 5 or 20 mg/kg indomethacin in combination with 2 g/kg ethanol. Ethanol co-administration significantly increased the concentration of indomethacin in the inflammed paw. Whether the observed interaction is due to increased concentration of indomethacin at the site of action or to direct interaction of ethanol and indomethacin in the inflammation process remains unclear.