Radioimmunoassay for benzo[a]pyrene.

A benzo[a]pyrene (BP)-bovine serum albumin conjugate was synthesized and used to immunize 2.5- to 3.0-kg New Zealand White rabbits. The resulting antisera to BP bound trace amounts of [3H] (55 pg; 6,000 counts/min). A radioimmunoassay (RIA) to BP was developed by the antiserum first being titered with the [3H]BP and then a standard curve being constructed from the addition of unlabeled BP (0.4-15.8 pmoles; 0.1-4.0 ng/assay tube). The RIA could reliably detect 0.4 pmoles (0.1 ng) BP. The specificity with respect to structurally related polycyclic aromatic hydrocarbons was examined by means of competitive binding. Here concentrations of 4.0-400 pmoles of the compound were used, and the resulting competitive curves were compared for relative cross-reactivity at 50% B/B0 (counts per minute labeled BP bound to antiserum in the presence of corresponding concentrations of unlabeled BP/counts per minute labeled BP bound to antiserum in the absence of unlabeled BP). The antiserum B4-3 was specific to BP with the closest cross-reacting substance being 3-hydroxybenzo[a]pyrene (20% relative cross-reactivity). BP added to pooled human serum was measurable by the RIA at 1 ng/ml. A BP RIA may have potential use for the quantification of the absorbed dose of this carcinogen in man.

Amphoteric drugs. 3. Synthesis and antiallergic activity of 3-[(5,11-dihydro[1]benzoxepino[4,3-b]pyridin-11- ylidene)piperidino]propionic acid derivatives and related compounds.

An important approach to the design of antiallergic agents with reduced penetration into the central nervous system (CNS) is described. A series of 3-[(5,11- dihydro[1]benzoxepino[4,3-b]-pyridin-11-ylidene)piperidino]propion ic acid derivatives (31-47) and related compounds (48-54) were synthesized and evaluated for antiallergic activity and penetration of a compound into the CNS in comparison with the corresponding 6H-dibenz[b,e]oxepin derivative (3). Combination of zwitterionization and introduction of a pyridine component resulted in an increase in antiallergic activity and a great reduction of penetration into the CNS, which was evaluated by the selectivity (B/A) of antihistaminic activities in the central system [ID50 value (B) for ex vivo H1 binding to mouse brain membranes] and in the peripheral system [ED50 value (A) for inhibitory effect on histamine-induced increase in vascular permeability in mice]. This surprising reduction of penetration into the CNS could be considered on the basis of an increase in hydrophilicity caused by both of the zwitterionization and the introduction of a pyridine component. 3-[4-(8-Fluoro-5,11-dihydro[1]benzoxepino[4,3- b]pyridin-11-ylidene)piperidino]propionic acid (33) exhibited a strong antiallergic effect in various experimental models and very low penetration into the CNS. Compound 33 (HSR-609) is now under clinical trial as a promising antiallergic agent with greatly reduced penetration into the CNS.

Endometriosis: the pathophysiology as an estrogen-dependent disease.

Endometriosis, defined as the presence of endometrial glands and stroma outside of the uterine cavity, develops mostly in women of reproductive age and regresses after menopause or ovariectomy, suggesting that the growth is estrogen-dependent. Indeed, the lesions contain estrogen receptors (ER) as well as aromatase, an enzyme that catalyses the conversion of androgens to estrogens, suggesting that local estrogen production may stimulate the growth of lesions. The expression patterns of ER and progesterone receptors in endometriotic lesions are different from those in the eutopic endometrium. Moreover, estrogen metabolism, including the expression pattern of aromatase and the regulation of 17 beta-hydroxysteroid dehydrogenase type 2 (an enzyme responsible for the inactivation of estradiol to estrone), is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. Immunostaining for P450arom in endometrial biopsy specimens diagnosed these diseases with sensitivity and specificity of 91 and 100%, respectively. This is applicable to the clinical diagnosis of endometriosis. The polymorphisms in the ER-alpha gene, the CYP19 gene encoding aromatase, and several other genes are associated with the risk of endometriosis. Studies of these will lead to better understandings of the etiology and pathophysiology of endometriosis.

Benzene-induced micronuclei formation in mouse fetal liver blood, peripheral blood, and maternal bone marrow cells.

The transplacental cytogenetic effects of benzene were studied by using the micronucleus test of polychromatic erythrocytes (PCE) found in both fetal liver and fetal peripheral blood, and were compared with PCE from maternal bone marrow. Timed-pregnant mice received single intraperitoneal doses of benzene (0, 109, 219, 437, or 874 mg/kg bw) on the 14th day of gestation and were sacrificed 21 hr after injection. Benzene elicited a significant increase (P less than 0.01) in the frequency of micronucleated polychromatic erythrocytes (MNPCE) in fetal liver blood cells (0.55 to 1.36%, control 0.18%) at doses of 219 to 874 mg/kg, and in fetal peripheral blood cells (0.49 to 0.58%, control 0.25%) and maternal bone marrow cells (0.53 to 0.70%, control 0.10%) at doses of 437 and 874 mg/kg. The data demonstrate that benzene is a moderate transplacental clastogenic agent, and that the mouse transplacental micronucleus test using fetal liver blood cells is a potentially more sensitive indicator of the genotoxicity of benzene than either fetal peripheral blood or maternal bone marrow cells.

Toxicity of Trp-P-2 to cultured human and rat keratinocytes.

Keratinocytes cultured from human and rat epidermis exhibited strongly divergent sensitivities to toxicity from the heterocyclic amine food mutagen Trp-P-2. To find a biochemical basis for this difference, the cultured cells were compared in their expression of phase 1 and 2 biotransformation activities, mutagenic activation and macromolecular adducts. The human and early passage rat cells expressed similar levels of ethoxyresorufin O-deethylase and N-acetyl transferase activities, their microsomes were similarly active in inducing bacterial mutagenesis when incubated with Trp-P-2, and the keratinocytes accumulated similar levels of DNA adducts over a 4-day treatment period. However, the human cells expressed an order of magnitude higher cytosolic glutathione S-transferase activity than the rat cells, likely providing enhanced protection. Late passage rat epidermal cells were insensitive to Trp-P-2 toxicity, attributable to their rapid loss of measured cytochrome P450 activity. Rat esophageal and fore-stomach epithelial cells resembled late passage rat epidermal cells in their lack of sensitivity to Trp-P-2 toxicity and lack of P450 activity. Human esophageal epithelial cells expressed substantial P450 activity but, in contrast to human epidermal cells, were sensitive to Trp-P-2 toxicity. Thus keratinocytes provide a valuable system in which to examine the basis for species- and tissue-specific differences in toxicity from this carcinogenic heterocyclic amine.

Cytotoxicity and keratinocyte microsome-mediated mutagenic activation of carcinogens in cultured epidermal cells.

Four model carcinogens (aflatoxin B(1), 6-nitrochrysene, 3-amino-1-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2)) were examined for their ability to inhibit the growth of cultured human and rat epidermal cells. To find a basis for observed differences in growth inhibition, aflatoxin B(1), Trp-P-1 and Trp-P-2 were tested for activation by microsomes isolated from these cells in a bacterial mutagenesis assay. Treated rat cultures exhibited sensitivity to Trp-P-1 and Trp-P-2 and especially aflatoxin toxicity (growth inhibition) despite their microsomes being unable to induce bacterial mutagenicity. In treated human cultures, the toxicities of Trp-P-1, Trp-P-2 and AFB(1) were stimulated by 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), consistent with their dependence on the biotransformation reactions this agent induces; however, the toxicity correlated poorly with observed bacterial mutagenicity mediated by their isolated microsomes. 6-Nitrochrysene, a known direct-acting mutagen in bacteria, was highly toxic to the rat but not to the human cells. Since toxic effects can modify carcinogenic outcomes, these findings are compatible with a complex relationship between toxicity, mutagenicity and carcinogenicity and indicate the utility of keratinocytes for clarifying this relationship.

A simple modification of the Salmonella liquid-incubation assay. Increased sensitivity for detecting mutagens in human urine.

A simple modification of the Salmonella/microsome liquid-incubation procedure improves the sensitivity of the assay for detecting mutagens in human urine. Extracts from cigarette smokers' urine were used as a model complex mutagenic mixture for validation of the assay. The modification consists of adding increased numbers of bacterial cells (approximately 10(9] in a concentrated suspension to liver homogenate mix and urine extract, all in 0.2-ml volume. After 90 min incubation at 37 degrees C, the mixture is processed according to the standard Ames test protocol. This procedure is 20 times more sensitive than the standard plate-incorporation test and 13 times more sensitive than a previously reported liquid-incubation protocol. The number of spontaneous revertants did not increase under these conditions and, compared to the plate-incorporation test, 10-fold less liver homogenate and 5-fold less enzymatic cofactors were needed per plate. The procedure was approximately 14 times more sensitive in detecting the mutagenic activity of benzo[ a ]pyrene. We also used the modification to determine mutagenic activity in urine from a group of nonsmokers. The method may be generally useful for investigations of mutagenic activity in human urine samples.

The kinetics of mutagen excretion in the urine of cigarette smokers.

The excretion of mutagens in the urine of cigarette smokers was studied as a model for absorption and elimination of complex carcinogenic and mutagenic mixtures in humans. Urine was collected from an occasional smoker who smoked 1 cigarette (17 mg tar/cigarette) and from a heavy smoker (smokes approximately 20 cigarettes/day) who quit for 2 days and then resumed smoking. Urine samples were collected for 6 days, including a 2-day pre-smoking period for the occasional smoker and pre-abstention period for the heavy smoker, respectively. Mutagen excretion patterns were determined by extracting the mutagens in each urine sample with XAD-2 resin and testing the extract in a microsuspension modification of the Salmonella/microsome liquid-incubation assay using bacterial strain TA98 with metabolic activation. Peak mutagenic activity of the urine collected from the two smokers appeared 4-5 h after the beginning of smoking. Activity decreased to pre-smoking "baseline' levels in approximately 12 h for the occasional smoker, and the activity for the heavy smoker approached the occasional smoker's 'baseline' in approximately 18 h after the cessation of smoking. The mutagen excretion patterns of the occasional smoker after smoking a single cigarette suggests that, the mutagens, as detected by the Salmonella assay, are absorbed rapidly (3-5 h) and are eliminated from the body following first order kinetics. The excretion rate constant for the occasional smoker was approximately 0.1 h-1 and the half-life (T1/2) was approximately 7 h.

Antimutagenicity of ellagic acid against aflatoxin B1 in the Salmonella microsuspension assay.

Ellagic acid (EA) is a phenolic compound with antimutagenic and anticarcinogenic properties. It occurs naturally in some foods such as strawberries, raspberries, grapes, black currants and walnuts. In the present study, we used the Salmonella microsuspension assay to examine the antimutagenicity of EA against the potent mutagen aflatoxin B1 (AFB1) using tester strains TA98 and TA100. Further, we used a two-stage incubation procedure that incorporates washing the bacterial cells free of the incubation mixture after the first incubation to investigate EA and AFB1 interaction. Three different concentrations of AFB1 (2.5, 5 and 10 ng/tube) were tested against five different concentrations of EA for TA98 and TA100. EA significantly inhibited mutagenicity of all doses of AFB1 in both tester strains with the addition of S9. EA alone was not mutagenic at the concentrations tested. The greatest inhibitory effect of EA on AFB1 mutagenicity occurred when EA and AFB1 were incubated together. Lower inhibition was apparent when the cells were first incubated with EA followed by a second incubation with AFB1, and also when the cells were first incubated with AFB1 followed by a second incubation with EA alone. The results of the sequential incubation studies support the hypothesis that one mechanism of inhibition could involve the formation of a chemical complex between EA and AFB1.

Micronucleus formation in cultured fetal liver blood cells using mitomycin C.

Mouse fetal-liver blood cells were cultured and used to investigate micronucleus formation after exposure to mitomycin C (MMC). The isolated fetal cells were incubated in a medium supplemented with erythropoietin (EPO), and the frequency of micronuclei formation was detected in polychromatic erythrocytes (PCE). The effects of four variables were investigated: (1) MMC exposure dose, (2) MMC exposure time, (3) incubation time, and (4) EPO concentration. PCE were formed by proliferation and differentiation of the erythroid cells in culture. Micronucleated PCE (MNPCE) were observed in a dose-dependent manner after exposing the cultured cells with up to 1.0 microgram/ml MMC. The optimum time of MMC exposure and post-exposure incubation was 3 h and 48 h, respectively, and the optimum EPO concentration was 0.25 U/ml. Mouse fetal-liver PCE are sensitive primordial cell targets that can be obtained in relatively large numbers from a single pregnant animal. The procedure is relatively simple and potentially useful in detecting mutagens and carcinogens capable of causing chromosomal damage.

Genotoxicity testing of methyl tertiary-butyl ether (MTBE) in the Salmonella microsuspension assay and mouse bone marrow micronucleus test.

Methyl tertiary-butyl ether (MTBE) is an oxygenated fuel additive that is present in gasoline at levels up to 15% by volume. Since the 1990 Clean Air Act amendments require the use of oxygenated gasoline in 39 areas of the USA, the use of MTBE is projected to continue to dramatically increase. As the use of MTBE increase, the potential for environmental release of MTBE from gasoline stations and automobiles will also increase. Despite its growing use as a fuel additive and its potential for increased exposure to the public, few genotoxicity data on MTBE have been published in the peer-review literature. In the present study, we tested the potential genotoxicity of MTBE in two short-term test systems, an in vitro Salmonella microsuspension assay and an in vivo mouse bone marrow micronucleus test. For the microsuspension assay, MTBE was tested at 7 dose levels of 30 to 7400 micrograms/tube in tester strain TA98, TA100, TA104, and TA1535, with and without the addition of metabolic enzymes (S9) at 4 concentration (0, 300, 600, and 1200 micrograms S9/ml final concentration). A closed system was used to minimize loss of MTBE. The response was not significant. However, a high degree of toxicity was observed at the highest doses in all tester strains. MTBE was also tested for clastogenicity i the mouse bone marrow micronucleus test using both male and female Swiss-Webster mice. Mice were administered single intraperitoneal injections of MTBE in olive oil at 5 doses ranging from 0.25 to 1.75 g/kg. There were no significant increases in micronucleus formation at any dose of MTBE when compared with the negative control animals receiving only olive oil. MTBE was not positive when tested for point mutations and clastogenicity, using respectively, a Salmonella microsuspension assay and the mouse bone marrow micronucleus test.

Inhibitory effects of ellagic acid on the direct-acting mutagenicity of aflatoxin B1 in the Salmonella microsuspension assay.

Ellagic acid (EA) is a phenolic compound that exhibits both antimutagenic and anticarcinogenic activity in a wide range of assays in vitro and in vivo. It occurs naturally in some foods such as strawberries, raspberries, and grapes. In the previous work, we used the Salmonella microsuspension assay to examine the antimutagenicity of EA against the potent mutagen aflatoxin B1 (AFB1) using tester strains TA98 and TA100. Briefly, the microsuspension assay was approximately 10 times more sensitive than the standard Salmonella/microsome (Ames) test in detecting AFB1 mutagenicity, and EA significantly inhibited mutagenicity of all AFB1 doses in both tester strains with the addition of S9. The greatest inhibitory effect of EA on AFB1 mutagenicity occurred when EA and AFB1 were incubated together (with metabolic enzymes). Lower inhibition was apparent when the cells were first incubated with EA followed by a second incubation with AFB1, or when the cells were first incubated with AFB1 followed by a second incubation with EA alone, all with metabolic enzymes. The result of these sequential incubation studies indicates that one mechanism of inhibition could involve the formation of an AFB1-EA chemical complex. In the present study, we further examine the effect of EA on AFB1 mutagenicity, but without the addition of exogenous metabolic enzymes. We report the mutagenicity of AFB1 in the microsuspension assay using TA98 and TA100 without the addition of S9. Neither the concentrations of AFB1 (0.6, 1.2, and 2.4 microg/tube) nor the concentrations of EA (0.3, 1.5, 3, 10, and 20 microg/tube) were toxic to the bacteria. The results indicate that AFB1 is a direct-acting mutagen, and that EA inhibits AFB1 direct-acting mutagenicity.

Measuring personal exposure to airborne mutagens and nicotine in environmental tobacco smoke.

The exposure of individuals to environmental tobacco smoke (ETS) is of increasing public health concern because epidemiological studies have associated passive smoking with increased risk of a variety of adverse health effects among non-smokers including lung cancer. As a way to measure individual exposure to the mutagenic compounds in the complex mixture of ETS, we used a sensitive Salmonella/microsome micro pre-incubation (microsuspension) assay to detect mutagenicity of particulate matter collected on filters from low volume (1.7 1/min flow rate) personal sampling pumps. Airborne nicotine was collected concurrently as a marker for ETS exposure. In pilot-field studies, individual exposure to ETS was measured in two separate indoor environments in which smokers were present: a gambling casino and a bingo parlor. Total suspended particulate matter (TSP) was collected on filters worn near the breathing zone of non-smoking individuals. Sampling times ranged from 40 min to 6 h. All extracts of filters had detectable levels of mutagenic activity (TA98, +S9) resulting in airborne mutagenic activity concentrations of 500-5000 rev/m3. The mutagenic activity of the filters from the casino and bingo parlors was significantly correlated with total particulate matter per filters (n = 12; Rho = 0.85, p less than 0.01) and with airborne nicotine per filter (n = 12; Rho = 0.95, p less than 0.01). The microsuspension assay was sufficiently sensitive to detect the mutagens associated with extracts of particulate matter from low volume samples (0.2-0.6 m3) in these indoor environments over a relatively short sampling time, and could be useful in studies of personal exposure to the mutagens in environmental tobacco smoke. Further, airborne nicotine concentrations were highly correlated with airborne mutagenicity and the mutagenic activity associated with ETS could therefore be estimated by the concentrations of nicotine.

Quantitative integration of the Salmonella microsuspension assay with supercritical fluid extraction of model airborne vapor-phase mutagens.

Vapor-phase mutagens are potentially a major class of toxic contaminants in ambient and indoor air. These compounds are not routinely analyzed due to a lack of an established integrated methodology to quantitatively trap, extract and test the compounds in a bioassay. In a previous report, we emphasized the trapping of volatile and semi-volatile mutagens and the extraction of these compounds using supercritical carbon dioxide (CO2). In the present study, we discuss the use of a bioassay for the quantitation of the model mutagens, ethylene dibromide(EDB) and 4-nitrobiphenyl (4-NB), trapped from an airstream. The compounds EDB and 4-NB were released into a controlled airstream, trapped on XAD-4 adsorbent, and were extracted using supercritical CO2. The extract was tested in a microsuspension modification of the Ames Salmonella/microsome test adapted for volatile compounds. Linear dose-response relationships were obtained for supercritical CO2-extracted EDB using tester strain TA100 (+/- S9) and for 4-NB using tester strains TA98 and TA100 (-S9). Standard dose-response curves with known amounts of the compounds were also determined for comparison with measured amounts of the model compounds collected in an airstream. The gas chromatographic (GC)- and bioassay-determined quantities of EDB and 4-NB were highly correlated, accurate and precise. For example, bioassay-determined EDB concentrations were within 10% of the GC-determined concentrations. Our results demonstrate that the integrated methodology for vapor-phase mutagens developed in this study would be useful for quantitative analysis of these and related airborne vapor-phase mutagenic compounds.

Genotoxicity of fractionated organic material in airborne particles from São Paulo, Brazil.

Particulate matter less than 10 microns aerodynamic diameter (PM10) is associated with adverse health effects including increased respiratory problems and mortality. PM10 is also associated with increases in cancer in some urban areas. Identification of toxic compounds in PM10 is a step toward estimating exposure to these compounds and evaluating their public health risk. However, the toxic compounds on PM10 are part of a highly complex mixture of compounds that makes chemical characterization difficult. Before this study, there has been little investigation of genotoxic compounds in particulate matter from Latin American cities. Here, both bioassay (mutagenicity) and chemical analyses were conducted with organic solvent extracts of PM10 collected from São Paulo, a major Brazilian city. Sequential extraction in dichloromethane (DCM) followed by acetone (ACE) yielded 20.3% and 10.2% of the total mass, respectively. Non-polar and moderately polar organic material solubilized in DCM. ACE extracted more polar organic species and some inorganic ions. Both extracts were fractionated separately using cyanopropyl-bonded silica chromatography with organic solvents of increasing polarity. The mass distribution among the fractions was measured. The mutagenic activity of the fractions was assayed using the microsuspension procedure with the Salmonella typhimurium tester strain TA98, with and without addition of metabolic enzymes (S9). The DCM extract had about four times higher mutagenic activity than the ACE extract. In general, addition of S9 resulted in an increase in mutagenicity of DCM fractions, but a decrease for the ACE extract. Most of the activity was concentrated in fractions in the mid-range of polarity within both the DCM and ACE extracts. The fractions were analyzed by gas chromatography with mass selective detection (GC/MS) without derivatization. The most mutagenic fractions in the DCM extract contained ketones, aldehydes, and quinolines. The most mutagenic ACE fraction had ketones, carboxylic acids, and aldehydes.

Enhancement of hepatocellular genotoxicity of several mutagens from amino acid pyrolysates and broiled foods following ethanol pretreatment.

The effect of subchronic ethanol ingestion on the genotoxicity and metabolism of the mutagens 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,5-b]indole (Trp-P-2), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-3,4- dimethylimidazo[4,5-f]quinoline (MeIQ) was evaluated in primary cultures of rat hepatocytes. Male Sprague-Dawley rats were pair-fed, for 8 days, liquid diets containing either ethanol (8%, v/v) or an isocaloric sucrose solution. Ethanol pretreatment significantly (P less than 0.05, Student's t test) enhanced the level of DNA repair stimulated by Glu-P-1, Glu-P-2, IQ and MeIQ. Statistically significant increases in DNA-repair activity ranged from 1.9-fold for IQ to 3.4-fold for Glu-P-2. Following a 16-hr exposure, the concentration of parent mutagen in the culture medium decreased by 75-98%. Neither the rate of mutagen metabolism in hepatocyte cultures nor the extent of mutagenic activation in microsome preparations was appreciably affected by ethanol pretreatment. The results suggest that ethanol pretreatment enhances the genotoxicity of Glu-P-1, Glu-P-2, IQ and MeIQ by inducing non-microsomal activation processes.

Immunohistochemical localization of aromatase and apoptosis-associated proteins in ovarian serous cystadenocarcinoma arising from ovarian endometriosis.

An immunohistochemical study was made of a case of serous cystadenocarcinoma that had been shown to have arisen from ovarian endometriosis. Aromatase cytochrome P450 (P450arom), an enzyme responsible for estrogen biosynthesis, was localized in the epithelial linings of the endometriosis and faintly in the transitional part, whereas it was not expressed in the carcinoma tissue. In contrast, estrogen receptors, progesterone receptors, and apoptosis-associated proteins, Fas, Fas ligand, and Bax were expressed in both endometriosis and carcinoma tissues of the tumor, whereas Bcl-2 was not expressed in either tissue of the tumor. It was suggested that the undifferentiated shift of the histologic grade might result in the loss of P450arom and that the malignant transformation was not caused by an altered balance of apoptosis-associated proteins. Accumulation of these studies may lead to a better understanding of the nature of malignant transformation of ovarian endometriosis.

Markers of exposure to diesel exhaust in railroad workers.

Diesel exhaust is a known mutagen and a potential human carcinogen. Recent epidemiological studies have demonstrated a small increase in the risk of lung cancer from diesel exhaust exposure. However, many epidemiological studies have used crude estimates of exposure, and even accurate measures of exposure may not be accurate estimates of the internal dose received. Measurement of diesel exhaust exposure also has been limited by the absence of a standard marker. This study was undertaken to evaluate the usefulness of urinary mutagenicity as a biological marker of diesel exhaust exposure in the workplace. We measured the exposure of individual railroad workers to diesel exhaust by using personal air samples taken over two consecutive work shifts. Nicotine in the samples was measured to adjust the respirable particle concentrations for active and passive cigarette smoking. Urine samples were collected at the end of the study work shifts and were analyzed for markers of cigarette smoking (nicotine, cotinine) and for mutagenicity, using a sensitive microsuspension assay (micro preincubation assay; Salmonella strain TA98 with or without S9 enzyme). The number of cigarettes smoked on the study shift was recorded, and subjects completed a questionnaire at the end of the second day on personal habits and exposures at home and work. Multiple regression analyses were used to analyze independent determinants of urinary mutagenicity, including a generalized least-squares analysis that divided residual variation into between- and within-person components. Eighty-seven subjects completed 151 two-day protocols; an additional four subjects provided usable data for a single day (n = 306 samples). Respirable particle concentration was not a good marker of diesel exhaust exposure when contamination by environmental tobacco smoke existed in the work location, but respirable particle concentration that was adjusted for environmental tobacco smoke correlated with a priori assessments of diesel exhaust exposure by job grouping. Phenanthrene concentration, as a potential marker, was measured in a subset of personal samples, and correlated with known diesel exhaust exposure by job grouping. A constant ratio of phenanthrene to respirable particles in area samples from diesel exhaust-exposed work locations suggested that phenanthrene is promising as a marker for diesel exhaust. Mutagenic activity was also measured from extracts of respirable particles in a few personal filter samples, and this technique may be useful for further investigation in epidemiological studies.(ABSTRACT TRUNCATED AT 400 WORDS)

[Synthesis and dual antagonistic activity against thromboxane A2 and leukotriene D4 of benzenesulfonamide derivatives].

In order to find dual antagonists against both thromboxane A2 (TXA2) and leukotriene D4 (LTD4) receptors for a new antiasthmatic agent, various benzenesulfonamide derivatives were synthesized and evaluated for those pharmacological effects. TXA2 and LTD4 antagonistic activities in vitro were evaluated by the inhibitory effects on LTD4-induced and U-46619-induced contraction of guinea-pig trachea. Furthermore, TXA2 and LTD4 antagonistic activities in vivo were evaluated by the inhibitory effects on LTD4-induced and U-46619-induced bronchoconstriction of guinea-pig after oral administration of test compounds. It was found that 4-[5-[1-(4-chlorobenzenesulfonamido)-5-methylhexyl]-2-thi eny l]butyric acid and 4-[5-[1-(4-fluorobenzenesulfonamido)-5-methyl-hexyl]-2-thienyl]but yric acid possess good anti-LTD4 and anti-TXA2 activities by oral administration.