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If Baptiste Brun didn’t exist, Jean Dubuffet and Art brut scholars probably would have invented him. His pioneering research has propelled the field forward, and filled in many gaps and lacunae along the way. To his credit, he has plumbed the archives and made a large number of previously buried primary sources available to a wider public. Baptiste Brun’s two recent publications, Jean Dubuffet et la besogne de l’Art brut : critique du Primitivisme, a revision of his doctoral dissertation, and...

Si Baptiste Brun n’existait pas, les specialistes de Jean Dubuffet et de l’Art brut l’auraient sans doute invente. Sa recherche novatrice a grandement fait avancer le champ d’etude, tout en comblant de nombreuses breches et lacunes par la meme occasion. Il faut reconnaitre qu’il a sonde les archives et rendu accessibles un grand nombre de sources primaires autrefois enfouies. Les deux publications recentes de l’auteur, Jean Dubuffet et la besogne de l’Art brut : critique du primitivisme, une ...

Arylamine N-acetyltransferase (NAT) enzymes catalyze the addition of an acetyl group from acetyl-CoA to a terminal nitrogen on a suitable substrate such as environmentally relevant compounds and pharmaceuticals. In human, there are two highly polymorphic active allozymes, NAT1 and -2, and one inactive pseudogene, NATP. The expression of these enzymes is tissue-specific such that NAT1 is ubiquitously expressed and NAT2 is confined mainly to liver and colorectal tissues. We hypothesized that these genes would be tissue-specifically transcriptionally regulated, and so we isolated putative proximal control regions for both the NAT genes, which were inserted into luciferase vectors and transiently transfected into human liver and bladder cells. The transfected cells were dosed with 4-aminosalicylic acid, sulfamethazine or solvent and the resulting luciferase activity was measured. We found that both NAT1 and -2 regions were inducible in liver cells by both xenobiotics but only one of the NAT1 regions was inducible again by both xenobiotics in bladder cells. These results suggest that the NAT genes may be tissue-specifically transcriptionally regulated.

We compared two protocols for 7,12-dimethylbenz[ a ]anthracene (DMBA)-induced mammary carcinogenesis. DMBA (20 mg/ml) was prepared at room temperature or at 60°C and administered by gavage to 50-day-old Sprague-Dawley rats. Two days post-DMBA, mammary epithelial DNA was 32 P-postlabeled. At 12 weeks post-DMBA, tumor DNA was screened for H- ras codon 61 mutations using an enriched polymerase chain reaction (EPCR). The number of in situ carcinomas (3.0 - 2.7 vs. 2.5 - 2.7), invasive carcinomas (1.1 - 1.6 vs. 0.6 - 0.8), and H- ras codon 61 mutations (34 - 13% vs. 23 - 13%) were statistically not different ( p = 0.05) between the groups. The relative adduct levels in mammary organoids were significantly ( p h 0.001) greater in the 60°C (568 - 158) than the room temperature (150 - 130) group. While DMBA-DNA adduct levels differed significantly between these protocols, this did not correlate with significant differences in tumor pathologies or H- ras codon 61 mutations.

N-Heterocyclic aromatics, such as carbazole and acridine derivatives, are environmental carcinogenic pollutants. Examples of these compounds are 7H-dibenzo[c,g]carbazole (DBC) and dibenz[a,j]acridine (DBA). The ionization potential (IP) for DBC is lower than for DBA. DBC is metabolized in lung and liver by way of phenols or directly through radical cations. DBC-induced liver and lung tumors have mutations in the 61st codon of ras. DBA is metabolized in skin by way of a diol-epoxide of DBA. DBA-induced skin tumors have mutations in 12th, 13th and 61st codons of ras. In summary, the metabolic activation of DBC proceeds through different adduction pattern pathways than does DBA and leads to different ras mutational spectra.

7H-Dibenzo[C, G]carbazole (DBC) is a potent liver, lung and skin carcinogen while dibenz[A, J]acridine (DBA) is a moderate skin carcinogen. DBC is metabolized to phenols and DBC-DNA adducts are formed through the 2-, 3-, and 4-phenols or directly through radical cations. Mutations in ras as a result of DBC, activation are found exclusively in codon 61 in liver, lung and skin. DBA is metabolized to dihydrodiols, and phenols and DBA-DNA adducts are formed through the diol-epoxides and possibly through bis-diol-epoxides. Mutations in ras, as a result of DBA activation, are found in codons 12, 13, and 61. These results indicate that although the two compounds are structurally similar, differing by one carbon in the middle ring, there are differences in their metabolism, DNA binding, mutational spectra and target-organ carcinogenesis.

There is increasing evidence implicating the human NF1 gene in epithelial carcinogenesis. To test if NF1 can play a part in skin tumor formation, we analyzed effects of the skin cancer initiator dimethylbenz-anthracene and/or the tumor promoter 12-O-tetradecanoyl-13-acetylphorbol on mice heterozygous for null mutations in Nf1 (Nf1+/–). Mice were on the C57BL/6 background, noted for resistance to chemical carcinogens. Nf1+/– mice (18 of 24) developed papillomas after treatment with dimethylbenzanthracene and 12-O-tetradecanoyl-13-acetylphorbol; papillomas did not develop in wild-type C57BL/6 mice nor Nf1+/– mice treated with 12-O-tetradecanoyl-13-acetylphorbol alone. All papillomas analyzed (six of six) had mutations in codon 61 of H-ras, demonstrating strong cooperation between the Nf1 GTPase activating protein for Ras, neurofibromin, and Ras-GTP. After exposure to 12-O-tetradecanoyl-13-acetylphorbol, Nf1+/– keratinocytes showed significant, sustained, increases in proliferation, implicating Nf1 in phorbol ester responsive pathways. Thus, Nf1 levels regulate the response of keratinocytes to 12-O-tetradecanoyl-13-acetylphorbol. Nf1+/– mice also showed a 2-fold increase in the development of pigmented skin patches stimulated by dimethylbenzanthracene; patches were characterized by hair follicles in anagen phase, implicating keratinocytes in the aberrant hyperpigmentation. Our results show that mutation in the Nf1 gene causes abnormal keratinocyte proliferation that can be revealed by environmental assaults such as carcinogen exposure. The data support a plausible role for NF1 mutation in human epithelial carcinogenesis.

7H-dibenzo[c,g]carbazole (DBC) is a potent liver and skin carcinogen when topically applied to the back skin of mice. This compound is found in complex mixtures produced during incomplete combustion of fossil fuels as well as in wood and tobacco smoke. The objective of this study was to elucidate the mechanism of action of this compound by assessing the Ha-ras mutational spectra of skin and liver tumors induced in a mouse model system. Low doses (50 nmol) and high doses (100 nmol) of DBC were applied topically to the backs of Hsd:ICR(Br) mice twice weekly. No treatment and solvent application were used as controls. After the mice were killed, the skin and liver tumors were removed, DNA was isolated, and tumor DNA was screened for Ha-ras codon 12, 13, and 61 mutations by using an enriched polymerase chain reaction method. Mutations were confirmed by reverse cyclic dideoxy sequencing. No mutations were found in codons 12 and 13 of DBC-induced tumors, whereas one acetone-control tumor had a codon 13 mutation. Sixty-seven percent of skin tumors and 45% of liver tumors induced by high doses of DBC and 67% of skin tumors induced by low doses of DBC contained codon 61 mutations, whereas liver tumors induced by low doses of DBC did not. The codon 61 mutations were exclusively A:T-->T:A transversions within the second base (CAA-->CTA). These results indicate that DBC is a unique polycyclic aromatic hydrocarbon in that it induces both skin and liver tumors upon topical application and that the mutational spectra are the same in tumors from two target organs, skin and liver, yet different from tumors from a third target organ, lung.

Runoff, soil loss and sediment bound total Kjeldahl nitrogen (TKN) and Bray P-l phosphorus losses from simulated rainfall were measured from five alternative corn and soybean tillage systems. Runoff and soil loss were influenced by contouring and tillage treatment. TKN concentration in the sediment was not greatly affected by tillage treatment and the average TKN enrichment ratio was 1.15. Bray P-l concentration in the soil and eroded sediment was significantly reduced by inversion plowing, and concentrations in the eroded sediment tended to decrease as soil loss increased. Bray P-l Enrichment ratios ranged from 1.7 to 4.5, and variations were not well correlated with soil loss.

River basin lag time (LAG), defined as the elapsed time between the occurrence of the centroids of the effective rainfall intensity pattern and the storm runoff hydrograph, is an important factor in determining the time to peak and the peak value of the instantaneous unit hydrograph, IUH. In the procedure of predicting a sedimentgraph (suspended sediment load as a function of time), the equivalent parameter is the lag time for the sedimentgraph (LAGs ), which is defined as the elapsed time between the occurrence of the centroids of sediment production during a storm event and the observed sedimentgraph at the gauging station. Results of analyses of rainfall, runoff and suspended sediment concentration event data collected from five small Carpathian basins in Poland and from a 2.31-ha agricultural basin, in central Illinois, USA have shown that LAGs was, in the majority of cases, smaller than LAG, and that a significant linear relationship exists between LAGs and LAG.

The Little Vermilion River (LVR) watershed in east central Illinois is an example of a watershed with altered hydrology from subsurface drainage systems. A continuous monitoring study has been conducted from 1991 to 2004 on this watershed to evaluate the effects of agricultural management practices on fertilizer and pesticide transport in subsurface flow. Water quality results obtained from four of the seven subsurface drainage stations in the LVR watershed for the period 1991-2000 are presented in this paper. The long-term monitoring results indicated that the nitrate-N concentration in subsurface drains varied depending on fertilizer application timing, rates and methods. Elevated nitrate concentrations were observed in the first few months of growing seasons. Long-term average annual flow weighted nitrate- N concentrations were lower than 10 mg/L under no-till system. Sites with reduced tillage practices had 10-year average annual flow weighted nitrate-N concentrations higher than MCL. Atrazine concentrations were lower than 3 µg/L in most water samples. Nevertheless, atrazine concentrations exceeded MCL in several incidents for all sites during the study period. Major atrazine loss in drainage water occurred within three months of atrazine application.

7H-Dibenzo[c,g]carbazole (DBC) is a model N-heterocyclic aromatic compound (NHA) which is both a hepatotoxin and hepatocarcinogen in rodents. The focus of this investigation was to determine whether human liver cell lines display differential sensitivities to DBC-induced toxicity. Treatment of cell lines with increasing DBC concentrations produced apoptosis only in HepG2 cells. Although DBC inhibited the clonogenic growth of all cell lines at high concentrations, only the survival of HepG2 cells was reduced at lower concentrations. DBC inhibited DNA synthesis in two (HepG2, HLF) of the three cell lines at lower concentrations and was effective only at a high concentration in Mahlavu cells. Differences in DBC uptake were not observed in any of the cell lines, suggesting that bioavailability was not a limiting factor. DBC-DNA adducts were not detected in HLF or Mahlavu cells at either low or high concentrations of DBC. Consistent with the DNA adduct data, RP-HPLC analysis indicated that DBC was metabolized to a lesser degree in the HLF and Mahlavu cells. These results suggest that human liver cell lines differ markedly in the ability to metabolize DBC to toxic species and that DBC-induced apoptosis is only observed in cells that produce detectable metabolites and DBC-DNA adducts.

Carcinogenic N-heterocyclic aromatic hydrocarbons are formed during the incomplete combustion of fossil fuels as well as cigarette smoke. N-Methyldibenzo[c,g]carbazole (NMeDBC) and 7H-dibenzo[c,g]carbazole (DBC) are members of this group. DBC induces mouse skin and liver tumors, whereas NMeDBC induces only mouse skin tumors. The objective of this study was to elucidate the mechanism of action of these compounds in skin by assessing the Ha-ras mutational spectra induced by a two-stage initiation-promotion protocol. NMeDBC (200 nmol) or DBC (200 nmol) was applied to the back skin of 24 female Hsd:ICR(Br) mice (12 per group) once. 12-O-tetradecanoylphorbol-13-acetate (TPA) (2 microg) was then applied twice weekly for 28 wk. Tumors were screened for Ha-ras mutations using enriched polymerase chain reaction and mutations defined by dideoxy sequencing. In DBC animals 58% produced papillomas, of which 71% had codon 61 mutations, 4% had codon 12 mutations, 4% had codon 13 mutations, and 21% had no Ha-ras mutations. In NMeDBC animals 92% produced papillomas, of which 73% had codon 61 mutations and 27% had no Ha-ras mutations. All of the codon 61 mutations, from both NMeDBC and DBC, were CAA-->CTA transversions. The DBC-induced tumors with the codon 12 mutation had a GGA-->GAA transition, and the codon 13 mutation was a GGC-->GTC transversion. These results suggest that NMeDBC is a more potent tumor inducer than DBC, but the resulting H-ras mutations in each group were predominantly in codon 61, and, therefore, mutation induction in skin by each chemical appears to proceed by a similar mechanism.

Agriculture is the leading source of non-point source pollution on a national scale. The driving force of non-point source pollution is the rainfall-runoff process, which is the transformation of rainfall to direct streamflow. This is a complex, nonlinear, time-varying, and space-distributed process on the watershed scale that is difficult to effectively model by conventional, deterministic means. Artificial neural networks (ANNs) offer a new approach to forecasting the hydrologic and water quality response of a watershed system. The goal of this work is to develop an ANN model as a long-term forecasting tool for predicting the hydrology and water quality of agricultural watersheds. The chosen form of neural network is a flexible mathematical structure, which is capable of identifying complex nonlinear relationships between input and output data sets. In this paper, a multi-layer, feed forward ANN model was developed and tested using historical daily rainfall, streamflow, and nitrate information. Using observed rainfall, stream flow, and water quality data from the Vermilion River and Little Vermilion River watersheds in Illinois; the ANN was applied to predict daily stream flow and nutrient loads based on rainfall. The results show highly accurate performance of the ANN model (R 2 values > 0.90) in predicting daily stream flow and nitrate loads.

7H-Dibenzo[c,g]carbazole (DBC), an N-heterocyclic aromatic hydrocarbon, is cytotoxic and carcinogenic in rodent liver. While DBC leads to necrotic lesions in the liver, the induction of apoptosis by DBC has not been investigated. The focus of this study was to determine the degree to which apoptosis and necrosis contributed to DBC cytotoxicity in a human hepatoma cell line (HepG2). To determine if these effects were unique to DBC, the results were compared to another hepatotoxin, aflatoxin B(1) (AFB(1)). DBC produced a distinct biphasic LDH release curve within 24 h of exposure. During the same time period lower concentrations of DBC (

Laboratory experiments were conducted to study effects of trickle emitter discharge rate on the distribution of soil moisture in a silty-clay loam soil. Both pulsed and continuous irrigation treatments were studied. A simulation model was used to evaluate the results obtained in the laboratory. The agreement between the predicted and measured soil moisture distribution patterns was quite good. For both pulsed and continuous applications, increasing trickle discharge rate resulted in a decrease in the horizontal component and an increase in the vertical component of the wetted soil profile. Compared to the continuous treatments, pulsed applications resulted in significant reduction in water loss below the root zone. Pulsed applications rates can replace continuous small discharge rates to reduce irrigation water runoff problems on heavy soils and with restricted infiltration allow the use of larger emitter orifices to decrease potential clogging of the trickle system.

Four peak runoff rate models were tested with 183 gage years of record to determine the model most applicable to small watersheds of mild topography in east-central Illinois. The Cypress Creek, Rational, Chow, and SCS peak runoff models were evaluated for their performance. Statistical analyses indicated the Soil Conservation Service model was most appropriate for the watersheds tested.

LABORATORY experiments were conducted to study the effects of trickle discharge rate on the distribution of soil water in a silty-clay loam soil. Good agreement was found between the laboratory results and those cal-culated using the Bresler (1975) model. Results indicated that increasing the trickle discharge rate resulted in an increase in the vertical component and a decrease in the horizontal component of the wetted zone.