Impact of after-treatment devices and biofuels on diesel exhausts genotoxicity in A549 cells exposed at air-liquid interface.

Using an air-liquid interface (ALI) device in dynamic conditions, we evaluated the efficiency of fuel after-treatment strategies (diesel oxidation catalysis, DOC, and diesel particulate filter, DPF, devices) and the impact of 7% and 30% rapeseed methyl esters (RME) blending on oxidative stress and genotoxicity induced in A549 lung cells after 3h exposure to whole Diesel exhausts. Oxidative stress was studied using assays of ROS production, glutathione level, catalase and superoxide-dismutase (SOD) activities. No oxidative stress and no clear differences on cytotoxicity patterns between biodiesel and standard Diesel exhausts were found. A weak but significant genotoxicity (8-oxodGuo adducts) and, for standard Diesel only, a DNA damage response (DDR) as evidenced by ƔH2AX foci, remained after DOC+DPF flowing. All together, these data could contribute to the improvement of the after treatment strategies and to health risk assessment of current diesel exhausts.

Comparative mutagenicity and genotoxicity of particles and aerosols emitted by the combustion of standard vs. rapeseed methyl ester supplemented bio-diesel fuels: impact of after treatment devices: oxidation catalyst and particulate filter.

Diesel exhausts are partly responsible for the deleterious effects on human health associated with urban pollution, including cardiovascular diseases, asthma, COPD, and possibly lung cancer. Particulate fraction has been incriminated and thus largely investigated for its genotoxic properties, based on exposure conditions that are, however, not relevant for human risk assessment. In this paper, original and more realistic protocols were used to investigate the hazards induced by exhausts emitted by the combustion of standard (DF0) vs. bio-diesel fuels (DF7 and DF30) and to assess the impact of exhaust treatment devices (DOC and DPF). Mutagenicity and genotoxicity were evaluated for (1) resuspended particles ("off line" exposure that takes into account the bioavailability of adsorbed chemicals) and for (2) the whole aerosols (particles+gas phase components) under continuous flow exposure ("on line" exposure). Native particles displayed mutagenic properties associated with nitroaromatic profiles (YG1041), whereas PAHs did not seem to be involved. After DOC treatment, the mutagenicity of particles was fully abolished. In contrast, the level of particle deposition was low under continuous flow exposure, and the observed mutagenicity in TA98 and TA102 was thus attributable to the gas phase. A bactericidal effect was also observed in TA102 after DOC treatment, and a weak but significant mutagenicity persisted after DPF treatment for bio-diesel fuels. No formation of bulky DNA-adducts was observed on A549 cells exposed to diesel exhaust, even in very drastic conditions (organic extracts corresponding to 500 µg equivalent particule/mL, 48 h exposure). Taken together, these data indicate that the exhausts issued from the bio-diesel fuels supplemented with rapseed methyl ester (RME), and generated by current diesel engines equipped with after treatment devices are less mutagenic than older ones. The residual mutagenicity is linked to the gas phase and could be due to pro-oxydants, mainly for RME-supplemented fuels.

Mutagenicity and clastogenicity of native airborne particulate matter samples collected under industrial, urban or rural influence.

Airborne particulate matter has recently been classified by the IARC as carcinogenic to humans (group 1). However, the link between PM chemical composition and its carcinogenicity is still unclear. The aim of the present study was to evaluate and to compare genotoxic potencies of 6 native PM samples collected in spring-summer or autumn-winter, either in industrial, urban or rural area. We evaluated their mutagenicity through Ames test on YG1041, TA98, and TA102 tester strains, and their clastogenicity on human bronchial epithelial BEAS-2B cells using comet assay, γ-H2AX quantification, and micronucleus assay. Ames test results showed a strong positive response, presumably associated with nitro-aromatics content. In addition, at least 2 positive responses were observed out of the 3 genotoxicity assays for each of the 6 samples, demonstrating their clastogenicity. Our data suggest that PM samples collected in autumn-winter season are more genotoxic than those collected in spring-summer, potentially because of higher concentrations of adsorbed organic compounds. Taken together, our results showed the mutagenicity and clastogenicity of native PM2.5 samples from different origins, and bring additional elements to explain the newly recognized carcinogenicity of outdoor air pollution.

Effects of alcohol consumption on biomarkers of oxidative damage to DNA and lipids in ethanol-fed pigs.

Chronic alcohol consumption is known to result in tissue injury, particularly in the liver, and is considered a major risk factor for cancers of the upper respiratory tract. Here we assessed the oxidative effects of subchronic ethanol consumption on DNA and lipids by measuring biomarkers 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and malondialdehyde (MDA), respectively. Physiological responses of pigs (n = 4) administered ethanol in drinking water for 39 days were compared with those of water-fed pigs (n = 4). Alcoholisation resulted in serum ethanol concentration of 1.90 g L(-1) and in a moderate but significant increase in alanine aminotransferase activity, an index of liver injury. However, between the alcoholised and control groups there were no significant differences in the levels of 8-oxodG (8-oxodG per 10(6) 2'deoxyguanosine) from leucocytes (2.52 ± 0.42 Vs 2.39 ± 0.34) or from target organs, liver, cardia and oesophagus. Serum MDA levels were also similar in ethanol-fed pigs (0.33 ± 0.04 µM) and controls (0.28 ± 0.03 µM). Interestingly, levels of 8-oxodG in cardia were positively correlated with those in oesophagus (Spearman correlation coefficient R = 1, P < 0.0001). Our results suggest that alcohol consumption may not cause oxidative damage to DNA and lipids as measured by 8-oxodG and MDA, respectively. The duration of alcoholisation and the potential alcohol-induced nutritional deficiency may be critical determinants of ethanol toxicity. Relevant biomarkers, such as factors involved in sensitization to ethanol-induced oxidative stress are required to better elucidate the relationship between alcohol consumption, oxidative stress and carcinogenesis.

Mutagenicity and genotoxicity of PM2.5 issued from an urbano-industrialized area of Dunkerque (France).

Epidemiological studies have demonstrated the link between chronic exposure to particulate matter (PM), especially particles with an aerodynamic diameter lesser than 2.5 µm (PM(2.5) ), and lung cancer. Mechanistic investigations focus on the contribution of the various genotoxicants adsorbed onto the particles, and more particularly on polycyclic aromatic hydrocarbons or nitroaromatics. Most of the previous studies dealing with genotoxic and/or mutagenic measurements were performed on organic extracts obtained from PM(2.5) collected in polluted areas. In contrast, we have evaluated genotoxic and mutagenic properties of urbano-industrial PM(2.5) (PM) collected in Dunkerque (France). Thermally desorbed PM(2.5) (dPM) was also comparatively studied. Suspensions of PM and dPM (5-50 µg per plate) were tested in Salmonella tester strains TA98, TA102 and YG1041 ± S9mix. Significant mutagenicity was observed for PM in YG1041 ± S9 mix. In strain TA102 - S9mix, a slight, but not significant dose-response increase was observed, for both PM and dPM. Genotoxic properties of PM and dPM were evaluated by the measurement of (1) 8-OHdG in A549 cells and (2) bulky DNA adducts on A549 cells and on human alveolar macrophages (AMs) in primary culture. A dose-dependant formation of 8-OHdG adducts was observed on A549 cells for PM and dPM, probably mainly attributed to the core of the particles. Bulky DNA adducts were observed only in AMs after exposure to PM and dPM. In conclusion, using relevant exposure models, suspension of PM(2.5) induces a combination of DNA-interaction mechanisms, which could contribute to the induction of lung cancer in exposed populations.

Toxigenic fungi and mycotoxins in mature corn silage.

To investigate the exposure of livestock and farm workers to mycotoxins during the last months of silage use, the mycoflora and the mycotoxins in a mature silage (11-months-old) were studied. A multimycotoxin method was developed to evaluate the toxigenic in vitro ability of fungal strains. The screening of potentially toxigenic fungi isolated from the mature silage showed that six Fusaria (Fusarium culmorum, Fusarium equiseti, Fusarium graminearum, Fusarium oxysporum, Fusarium solani and Fusarium verticillioides) and one Aspergillus (Aspergillus fumigatus) were able to produce mycotoxins on nutrient agar. Seven major mycotoxins (aflatoxin B(1), citrinin, deoxynivalenol, fumonisin B(1), gliotoxin, ochratoxin A and zearalenone) were also searched in the corn silage by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Among the three mycotoxins (citrinin, gliotoxin and deoxynivalenol) detected in the silage, gliotoxin, a strongly immunosuppressive mycotoxin, occurred in the mature silage at level up to 877 ppb, which was associated with the presence of A. fumigatus in the silage.

Evidence of genotoxicity related to high PAH content of sediments in the upper part of the Seine estuary (Normandy, France).

In order to characterize the genotoxicity in the Seine estuary and Seine bay, chemical and toxicological analyses were performed on 17 sediments collected in June 2001 and June 2003. Many potent mutagenic and/or carcinogenic compounds - including polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and metals - were detected. Those compounds were found to be at relatively high concentrations in the upper part of the Seine estuary but were barely detectable at sites outside the plume from the Seine. The levels of pollution did not vary significantly between the two sampling periods, except that PAH concentrations in sediments collected at Oissel and Le Havre showed a marked increase in June 2003. The toxicity of organic extracts from sediments was evaluated by both embryotoxicity and in vitro genotoxicity (SOS Chromotest) assays. Organic extracts from sediments taken from the Seine estuary appeared significantly more embryotoxic than those from the Seine bay. In addition, the sediment extracts from the upper part of the Seine estuary exhibited higher genotoxicity than those from the lower part, and no genotoxicity was reported for sediments from the Seine bay. The genotoxic activity was detected only after adding an S9 microsomal fraction, suggesting the preponderant involvement of pro-genotoxic organic compounds. In addition, SOS Chromotest responses obtained with purified organic fractions revealed that PAH and, to a lesser extent, unknown polar organic compounds were probably responsible for this genotoxicity. Altogether, these results suggest that sediments from the upper Seine estuary are genotoxic and embryotoxic, and therefore, could be potentially hazardous for species living or feeding in the area.

Genotoxicant accumulation and cellular defence activation in bivalves chronically exposed to waterborne contaminants from the Seine River.

The aim of the present work was to investigate genotoxicant accumulation and biological responses of zebra mussels and blue mussels collected along a pollution gradient in the Seine estuary and in the Seine Bay. The sampling area included three contaminated and one reference sites for each species. The study focused on polyaromatic hydrocarbons (PAH), lindane, polychlorobiphenyls (PCB) and metals known to be potential genotoxicants and/or reactive oxygen species (ROS) inducers. Enzymatic activities related to cellular defence systems including the phase II enzyme glutathione S-transferase (GST) and three antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were measured in gills. DNA adducts and DNA strand breaks (Comet assay) were measured in digestive gland and hemocytes, respectively. Species differences were observed in metal accumulation (As and Pb), GPx activity and DNA adduct formation. A marked upstream-downstream gradient was reported for PAH body burden and to a lesser extent for PCB and metals with the highest values measured just downstream the industrialized area of Rouen. GST and SOD activities in gills of bivalves were positively related to PAH and metals body burden, respectively. Activation of those cellular defences may prevent accumulation of electrophilic metabolites and free radicals and thus may protect DNA and others macromolecules against oxidation and adduction. Although DNA strand breaks and bulky adducts were detected in both species, levels were relatively low and no significant site differences were observed in June 2003. Our results indicate a clear relationship between genotoxicant accumulation and positive activation of detoxification and antioxidant systems but poor consequences in term of DNA damage for wild population of mussels inhabiting the Seine estuary.

DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas. Potential use for genotoxicant biomonitoring of fresh water ecosystems.

The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a 32P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of 32P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 microg g(-1) dry weight) in comparison to individuals from the reference site (0.053 microg g(-1) dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10(8) nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 microg g(-1) dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 microg g(-1) dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10(8) nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced 32P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in zebra mussels could be a suitable biomarker to monitor PAH-exposure and evaluate genotoxicity in fresh water ecosystems.

Seasonal variations of DNA-adduct patterns in open field farmers handling pesticides.

Seasonal variations of DNA-adduct levels in peripheral blood cells were evaluated in open field farmers (n=26) by use of the 32P-postlabelling assay. Samples were collected before (sample S0) and during (sample S4) the period of intensive pesticide use. A similar sampling procedure was applied to a referent group (n=29). Exposure to pesticides was estimated via a detailed questionnaire. For the group of farmers, an increase in mean adduct level was observed during the season (mean RALS0=3.9+/-3.4 x 10(-10), mean RALS4=13.3+/-15.7 x 10(-10); p=0.008; RAL=relative adduct level). The mean adduct levels were significantly different between farmers and referents only in the S4 samples, with higher levels for farmers (p=0.02). The number of different adducts per individual was higher for farmers at S4 when compared with S0 (p=0.02) and compared with the referents at S4 (p=0.03). However, the increase of the adduct level in farmers did not seem to be attributable to the occurrence of specific new adducts in S4 as compared with S0, but was supposedly due to intensification of pre-existing spots and/or appearance of new unspecific ones. This would be in agreement with indirect genotoxic (epigenetic) effects known for several pesticides, even though a direct mechanism cannot be ruled out definitively. The implication of the pesticides used by the farmers in the modulation of DNA-adduct patterns was explored by analysis of exposure data obtained from the questionnaire.

Urine mutagenicity and lymphocyte DNA damage in fruit growers occupationally exposed to the fungicide captan.

AIMS: To determine haematological parameters, urine mutagenicity (on three Salmonella typhimurium strains), and DNA damage (using the comet assay) in mononuclear leucocytes of farmers before and after a one-day spraying period of pear and apple trees with the fungicide captan in usual conditions. METHODS: Fruit growers were exposed to captan during the 1998 (n = 12) and/or the 2000 spraying seasons (n = 17). Biological samples were collected on the morning of the day of spraying (S1), the evening after spraying (S2), and the morning of the day after (S3). The UK Predictive Operator Exposure Model (UK-POEM) was used to quantify pesticide exposure intensity. RESULTS: No effect was observed on haematological parameters for these two spraying seasons. Proportions of mutagenic urine samples did not significantly differ between S1 and S2/S3 sampling points. In contrast with strains TA97a and YG1041 mainly sensitive to frameshift mutations, a positive trend was observed between the difference (S3-S1) of mutagenic power on strain TA102 detecting base-pair mutations and the exposure predicted value given by UK-POEM, mainly due to parameters related to protective clothing. No significant variations in DNA damage levels were observed between S1 and S3, nor were correlations observed with parameters of pesticide exposure. CONCLUSIONS: A one-day spraying period with captan and other pesticides does not significantly induce DNA damages in mononuclear leucocytes. In contrast, an inefficient protective clothing could correlate with an increase in urine mutagenicity as assessed by the TA102 tester strain.

Population mixing and leukaemia in young people around the La Hague nuclear waste reprocessing plant.

In order to investigate for an association between population mixing and the occurrence of leukaemia in young people (less than 25 years), a geographical study was conducted, for the years 1979 to 1998, in Nord Cotentin (France). This area experienced between the years 1978 and 1992 a major influx of workers for the construction of a nuclear power station and a new nuclear waste reprocessing unit. A population mixing index was defined on the basis of the number of workers born outside the French department of 'La Manche' and living in each 'commune', the basic geographical unit under study. The analyses were done with indirect standardisation and Poisson regression model allowing or not for extra-Poisson variation. Urban 'communes' were considered as the reference population. The Incidence Rate Ratio was 2.7 in rural 'communes' belonging to the highest tertile of population mixing (95% Bayesian credible interval, 95%BCI=1.2-5.9). A positive trend was observed among rural strata with increasing population mixing index (IRR for trend=1.4, 95%BCI=1.1-1.8). The risk became stronger for Acute Lymphoblastic Leukaemia in children 1-6 years old in the highest tertile of population mixing (IRR=5.5, 95%BCI=1.4-23.3). These findings provide further support for a possible infective basis of childhood leukaemia.

The incidence of childhood leukaemia around the La Hague nuclear waste reprocessing plant (France): a survey for the years 1978-1998.

BACKGROUND: A previous study has suggested an increased incidence rate of leukaemia from 1978 to 1992 in people aged 0 to 24 years and living in the vicinity of the La Hague nuclear waste reprocessing plant without considering age and cytological type. SETTING: The Nord Cotentin region (France) and the island of Alderney (United Kingdom). STUDY OBJECTIVE: To describe the occurrence of leukaemia for each age group and cytological type from 1978 to 1998 in the same area, using accurate reference incidence rates and adequate estimation of the at risk population. DESIGN: A geographical study of incidence using three zones defined according to their distance from the site (0 to 10 km: Beaumont-Hague electoral ward, 10 to 20 km and 20 to 35 km) has been conducted. The risk of leukaemia was estimated from the standardised incidence ratio (SIR) of the number of cases observed to the number expected. Exact 95% confidence intervals (CI) have been computed. PARTICIPANTS: All people under the age of 25 years living in the study region between 1978 and 1998. MAIN RESULTS: The observed number of cases of leukaemia in the study region as a whole was consistent with the expected value (SIR=1.03; 95%CI: 0.73, 1.41). No cases were observed on Alderney. The SIR in the Beaumont-Hague electoral ward was 2.17 (95%CI: 0.71, 5.07). The highest SIR was observed in the 5 to 9 years age group (SIR=6.38; 95%CI: 1.32, 18.65). This consists in acute lymphoblastic leukaemia cases. CONCLUSION: This study indicates an increased incidence of leukaemia in the area situated at less than 10 km from the plant. Monitoring and further investigations should be targeted at acute lymphoblastic leukaemia occurring during the childhood incidence peak (before 10 years) in children living near the La Hague site and may be other nuclear reprocessing plants.

Localized squamous-cell cancer of the esophagus: retrospective analysis of three treatment schedules.

BACKGROUND AND PURPOSE: A retrospective study comparing chemotherapy and radiation, esophagectomy alone versus preoperative radiochemotherapy and surgery in localized squamous-cell esophageal carcinoma. MATERIALS AND METHODS: Between 1989 and 1995, 139 patients (40 stage I, 77 stage IIA and 22 stage IIB according to the UICC 78 TNM classification) were treated in two different institutions. They were divided into three groups according to the treatment proposed: E group (treatment by esophagectomy; n = 30), RCT+E group (treatment by preoperative radiochemotherapy and esophagectomy; n = 46), RCT group (treatment by radiochemotherapy; n = 63). Factors like age, tumor localization and stage were similar in all groups. An intention to treat analysis was made. RESULTS: The E group showed no postoperative mortality, while in the RCT+E group, the surgery mortality was 12.8%. The mortality after RCT was 1.7%. After preoperative radiochemotherapy, a pathological complete response was observed in 25% of cases and the curative resection rate was higher (82% after RCT + E versus 60% after E). The 5-year survival difference between the three groups was not relevant (E group, 12.6%; RCT group, 25.8%; RCT + E group, 38.7%). The median survival was 29, 24 and 28.5 months, respectively. The event-free survival was identical for the E group and the RCT group. For patients treated by radiochemotherapy, local and/or distant relapses were significantly reduced by esophagectomy (relapses occurred in 51% of patients in the RCT + E group versus 75% in the RCT group, P = 0.017). Palliative care (dilatations, prosthesis, gastrostomy or jejunostomy) to improve dysphagia was necessary for 38% of patients treated by exclusive radiochemotherapy versus 11% of patients treated by surgery (P = 0.001). CONCLUSIONS: Treatments by esophagectomy or radiochemotherapy were not significantly different. Preoperative radiochemotherapy and surgery lead to a higher survival rate than exclusive radiochemotherapy, however, with a high postoperative mortality rate. This study suggests the relevance of a prospective randomized trial to compare RCT+E and RCT alone.

Understanding variations in survival for colorectal cancer in Europe: a EUROCARE high resolution study.

BACKGROUND: Marked differences in population based survival across Europe were found for colorectal cancers diagnosed in 1985-1989. AIMS: To understand the reasons for these differences in survival in a new analysis of colorectal cancers diagnosed between 1988 and 1991. SUBJECTS: A total of 2720 patients with adenocarcinoma of the large bowel from 11 European cancer registries (CRs). METHODS: We obtained information on stage at diagnosis, diagnostic determinants, and surgical treatment (not routinely collected by CRs) and analysed the data in relation to three year observed survival, calculating relative risks (RRs) of death and adjusting for age, sex, site, stage, and determinants of stage. RESULTS: Three year observed survival rates ranged from 25% (Cracow) to 59% (Modena), and were low in the Thames area (UK) (38%). Survival rates between registries for "resected" patients varied less than those for all patients. When age, sex, and site were considered, RRs ranged from 0.7 (95% confidence intervals (CI) 0.6-0.9) (Modena) to 2.3 (95% CI 1.9-2.9) (Cracow). After further adjustment by stage, between registry RR variation was between 0.8 (95% CI 0.6-0.9) and 1.8 (95% CI 1.5-2.2). Inter-registry RR differences were slightly reduced when the determinants of stage (number of nodes examined and liver imaging) were included in the model. The reduction was marked for the UK registries. CONCLUSIONS: The wide differences across Europe in colorectal cancer survival depend to a large extent on differences in stage at diagnosis. There are wide variations in diagnostic and surgical practices. There was a twofold range in the risk of death from colorectal cancer even after adjustment for surgery and disease stage.

Moral reasoning, interpersonal skills, and cognition of rapists, child molesters, and incest offenders.

54 inmates were subdivided into four groups and classified according to their index offense. The groups included Rapists (n = 14), Incest Offenders (n = 9), Child Molesters (n = 11), General Offenders (n = 20). Nonoffenders (n = 20) were included as a control group. Psychometric tests including the Test of Nonverbal Intelligence, the Defining Issues Test, Survey of Interpersonal Values, Porteus Maze, and Minnesota Multiphasic Personality Inventory were administered to all inmate and control groups. Analysis showed the rapists and child molesters scored higher on moral reasoning on the Defining Issues Test; also rapists' scores were more elevated on the Psychopathic Deviate and Paranoia scales of the Minnesota Multiphasic Personality Inventory than those of other offender and control groups. These results imply that rapists and child molesters have the ability to understand moral issues; however, given their personality orientation, they ignore these interpersonal social values.

Risk factors in violent and nonviolent offenders.

Factors leading to risk for violence were evaluated in an offender population of 36 male offenders including 18 Violent, e.g., assault, threatening and 17 nonviolent (break and enter, theft), and 17 nonoffenders. Their scores on the Psychopathy Checklist Revised, Violence Risk Scale-Experimental Version 1, Minnesota Multiphasic Personality Inventory-168, and the Porteus Maze tests showed scores for the inmates with violent offenses were elevated on Psychopathic Deviate, Paranoia, Schizophrenia scales of the Minnesota Multiphasic Personality Inventory, violence risk of the Violence Risk Scale, showed psychopathic orientation on the Psychopathy Checklist Revised, and had a lower test age quotient score on the Porteus Maze test.

Comparative in vitro and in vivo assessment of genotoxic effects of etoposide and chlorothalonil by the comet assay.

The alkaline single cell gel electrophoresis (comet) assay was used to assess in vitro and in vivo genotoxicity of etoposide, a topoisomerase II inhibitor known to induce DNA strand breaks, and chlorothalonil, a fungicide widely used in agriculture. For in vivo studies, rats were sacrificed at various times after treatment and the induction of DNA strand breaks was assessed in whole blood, bone marrow, thymus, liver, kidney cortex and in the distal part of the intestine. One hour after injection, etoposide induced DNA damage in all organs studied except kidney, especially in bone marrow, thymus (presence of HDC) and whole blood. As observed during in vitro comet assay on Chinese hamster ovary (CHO) cells, dose- and time-dependent DNA effects occurred in vivo with a complete disappearance of damage 24 h after administration. Even though apoptotic cells were detected in vitro 48 h after cell exposure to etoposide, such a result was not found in vivo. After chlorothalonil treatment, no DNA strand breaks were observed in rat organs whereas a clear dose-related DNA damage was observed in vitro. The discrepancy between in vivo and in vitro models could be explained by metabolic and mechanistic reasons. Our results show that the in vivo comet assay is able to detect the target organs of etoposide and suggest that chlorothalonil is devoid of appreciable in vivo genotoxic activity under the protocol used.

[Superficial cancer of the stomach in the area of Calvados from 1978 to 1990. Epidemiology and prognostic factors]. / Le cancer superficiel de l'estomac dans le département du Calvados de 1978 á 1990. Epidémiologie et facteurs pronostiques.

AIMS OF THE STUDY: The 5-year survival rate of gastric cancer is less than 20% in cancer registries. The prognosis of early gastric cancer is much better but this diagnosis is rare in Europe. The aim of the study was to evaluate the prognosis and trends in the incidence of early gastric cancer in the area of Calvados (France) during a 13-year period. METHODS: Between 1978 and 1990 the Digestive Cancer Registry of Calvados recorded 1,160 new cases of gastric cancer. The diagnosis of early gastric cancer was defined according to the Japanese Gastroenterological Society criteria. Prognostic factors were determined with univariate and multivariate analysis. RESULTS: One hundred patients had early gastric cancer (8.6%). This rate did not change significantly during the period. The mean age was 64.2 +/- 1.5 in males and 64.8 +/- 2.2 in females and 39% of patients were older than 70. A precancerous condition was present in 56% of cases on the surgical specimen. A total gastrectomy was performed in 23% of cases and a subtotal gastrectomy in 72% of cases. The postoperative mortality was 5% and the 5-year relative survival was 86.8% +/- 4.6. Univariate and multivariate analysis found a better prognosis in patients younger than 75 or in patients with a superficial or excavated gross appearance compared with those older than 75 or with a protruded type. Lymph node metastasis, depth of invasion, size of the tumor and histologic differentiation did not influence significantly the outcome. CONCLUSION: According to the data of the Cancer Registry of Calvados the proportion of Early Gastric Cancer was low and did not change between 1978 and 1990. The prognosis of EGC is good, mainly altered in elderly and in cases with a protruded type.