Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 1999. / Typescript. Bibliography: p. 115-134.

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 2001. / Typescript. Bibliography: leaves 123-144.

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, / Typescript. Bibliography: leaves 184-211.

Produtos naturais são cada vez mais vendidos como suplementos dietéticos devido a várias das suas propriedades terapêuticas, enfatizando a pesquisa para novos medicamentos. Este trabalho mostra que extratos aquosos de Lentinula edodes, Pleurotus sajor-caju e Agaricus blazei exercem atividade citotóxica, através do ensaio da redução do sal de brometo tetrazólio, nas linhagens celulares humanas de carcinoma de laringe (Hep-2) e carcinoma cervical (HeLa). Os extratos foram obtidos inicialmente em três diferentes temperaturas (4C, 22ºC e 50C). Entretanto, a temperatura ambiente foi escolhida para a realização dos outros experimentos já que apresentou os melhores resultados na redução da viabilidade celular. Ensaios bioquímicos realizados em paralelo indicaram uma maior quantidade de polifenóis nos extratos do L. edodes nas três temperaturas de extração e também uma melhor capacidade de eliminação do radical 2,2-difenil-1-picrilhidrazilo. Os resultados para a atividade citotóxica revelaram que o extrato de P. sajor-caju foi mais eficiente do que os extratos de L. edodes e A. blazei, nas linhagens testadas. Modificações morfológicas observadas nas células foram confirmadas pela coloração de Giemsa, após o tratamento com os extratos, sugerindo a inibição da proliferação e indução da apoptose dose/dependente. O tipo de morte celular foi testada com o método da anexina V acoplada a um fluorocromo mais iodeto de propídio, confirmando que tanto os extratos de L. edodes e P. sajor-caju induzem a apoptose tardia. Ensaios da composição química obtidos por cromatografia gasosa acoplada ao espectrômetro de massas mostraram a presença de ácidos graxos nos extratos, com uma prevalência do ácido palmítico no extrato de L. edodes e P. sajorcaju e ácido esteárico no extrato de A. blazei. A quantificação dos carboidratos e proteínas indicaram uma maior quantidade de carboidratos no L. edodes, e o A. blazei apresentou um maior teor de proteínas. Estes resultados indicam que os extratos aquosos dos cogumelos L. edodes, P. sajor-caju e A. Blazei são potenciais fontes antioxidantes, ricos em proteínas e ácidos graxos e possuem atividade anticancerígena por indução da apoptose. No entanto, novos estudos são necessários para explorar seus usos terapêuticos e para elucidar o seu modo de ação no organismo. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-11T12:32:57Z No. of bitstreams: 1 Dissertacao Tiane Cristine Finimundy.pdf: 150195 bytes, checksum: 16fa4de06cc7be6b6a285105c8c35610 (MD5) / Made available in DSpace on 2014-06-11T12:32:57Z (GMT). No. of bitstreams: 1 Dissertacao Tiane Cristine Finimundy.pdf: 150195 bytes, checksum: 16fa4de06cc7be6b6a285105c8c35610 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Natural products are increasingly sold as dietary supplements due to several of its therapeutic properties, emphasizing the search for new drugs. This work shows that aqueous extracts of Lentinula edodes, Pleurotus sajor-caju and Agaricus blazei, exert cytotoxic activity by testing the reduction of tetrazolium bromide salt in human cell lines of laryngeal carcinoma (Hep-2) and cervix carcinoma (HeLa). The extracts were obtained initially at three different temperatures (4C, 22ºC and 50C), however ambient temperature was chosen to carry out other experiments that have shown the best results in the reduction of cell viability. Biochemical assays performed in parallel showed an increased amount of polyphenols in the extracts of L. edodes the three extraction temperatures and also a better ability to eliminate the radical 2,2-diphenyl-1- picrylhydrazyl. The results for the cytotoxic activity revealed that the extract of P. sajor-caju was more efficient than that of L. edodes and A. blazei, the strains tested. Observed morphological changes in the cells was confirmed by Giemsa staining after treatment with the extracts, suggesting that the inhibition of proliferation and induction of apoptosis dose/dependent. The type of cell death was assayed by the method of annexin V bound to a fluorochrome and propidium iodide further confirming that both of L. edodes and P. sajor-caju induce apoptosis late. Testing the chemical composition obtained by gas chromatography mass spectrometer showed the presence of fatty acids in the extracts, with a prevalence of palmitic acid in the extract of L. edodes and P. sajor-caju and stearic acid extract of A. blazei. The quantification of carbohydrates and proteins indicated a greater amount of the carbohydrates L. edodes and A. blazei showed a higher protein content. These results indicate that the aqueous extracts of the mushroom L. edodes , P. sajor-caju and A. blazei, are potential sources antioxidants, high in protein and fatty acids and have anticancer activity by induction of apopt sis. However, further studies are needed to explore their therapeutic use and to elucidate its systemic effects.

Produtos naturais são cada vez mais vendidos como suplementos dietéticos devido a várias das suas propriedades terapêuticas, enfatizando a pesquisa para novos medicamentos. Este trabalho mostra que extratos aquosos de Lentinula edodes, Pleurotus sajor-caju e Agaricus blazei exercem atividade citotóxica, através do ensaio da redução do sal de brometo tetrazólio, nas linhagens celulares humanas de carcinoma de laringe (Hep-2) e carcinoma cervical (HeLa). Os extratos foram obtidos inicialmente em três diferentes temperaturas (4C, 22ºC e 50C). Entretanto, a temperatura ambiente foi escolhida para a realização dos outros experimentos já que apresentou os melhores resultados na redução da viabilidade celular. Ensaios bioquímicos realizados em paralelo indicaram uma maior quantidade de polifenóis nos extratos do L. edodes nas três temperaturas de extração e também uma melhor capacidade de eliminação do radical 2,2-difenil-1-picrilhidrazilo. Os resultados para a atividade citotóxica revelaram que o extrato de P. sajor-caju foi mais eficiente do que os extratos de L. edodes e A. blazei, nas linhagens testadas. Modificações morfológicas observadas nas células foram confirmadas pela coloração de Giemsa, após o tratamento com os extratos, sugerindo a inibição da proliferação e indução da apoptose dose/dependente. O tipo de morte celular foi testada com o método da anexina V acoplada a um fluorocromo mais iodeto de propídio, confirmando que tanto os extratos de L. edodes e P. sajor-caju induzem a apoptose tardia. Ensaios da composição química obtidos por cromatografia gasosa acoplada ao espectrômetro de massas mostraram a presença de ácidos graxos nos extratos, com uma prevalência do ácido palmítico no extrato de L. edodes e P. sajorcaju e ácido esteárico no extrato de A. blazei. A quantificação dos carboidratos e proteínas indicaram uma maior quantidade de carboidratos no L. edodes, e o A. blazei apresentou um maior teor de proteínas. Estes resultados indicam que os extratos aquosos dos cogumelos L. edodes, P. sajor-caju e A. Blazei são potenciais fontes antioxidantes, ricos em proteínas e ácidos graxos e possuem atividade anticancerígena por indução da apoptose. No entanto, novos estudos são necessários para explorar seus usos terapêuticos e para elucidar o seu modo de ação no organismo. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Natural products are increasingly sold as dietary supplements due to several of its therapeutic properties, emphasizing the search for new drugs. This work shows that aqueous extracts of Lentinula edodes, Pleurotus sajor-caju and Agaricus blazei, exert cytotoxic activity by testing the reduction of tetrazolium bromide salt in human cell lines of laryngeal carcinoma (Hep-2) and cervix carcinoma (HeLa). The extracts were obtained initially at three different temperatures (4C, 22ºC and 50C), however ambient temperature was chosen to carry out other experiments that have shown the best results in the reduction of cell viability. Biochemical assays performed in parallel showed an increased amount of polyphenols in the extracts of L. edodes the three extraction temperatures and also a better ability to eliminate the radical 2,2-diphenyl-1- picrylhydrazyl. The results for the cytotoxic activity revealed that the extract of P. sajor-caju was more efficient than that of L. edodes and A. blazei, the strains tested. Observed morphological changes in the cells was confirmed by Giemsa staining after treatment with the extracts, suggesting that the inhibition of proliferation and induction of apoptosis dose/dependent. The type of cell death was assayed by the method of annexin V bound to a fluorochrome and propidium iodide further confirming that both of L. edodes and P. sajor-caju induce apoptosis late. Testing the chemical composition obtained by gas chromatography mass spectrometer showed the presence of fatty acids in the extracts, with a prevalence of palmitic acid in the extract of L. edodes and P. sajor-caju and stearic acid extract of A. blazei. The quantification of carbohydrates and proteins indicated a greater amount of the carbohydrates L. edodes and A. blazei showed a higher protein content. These results indicate that the aqueous extracts of the mushroom L. edodes , P. sajor-caju and A. blazei, are potential sources antioxidants, high in protein and fatty acids and have anticancer activity by induction of apopt sis. However, further studies are needed to explore their therapeutic use and to elucidate its systemic effects.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / AvaliaÃÃo dos efeitos da administraÃÃo diÃria, intragÃstrica (ig) e subcutÃnea (sc) prolongada do produto hidrossolÃvel da prÃpolis verde, extraÃda em L-lisina e do aminoÃcido L-lisina ig sobre a angiogÃnese de carcinomas de bexiga e a carcinogÃnese de bexiga induzida pelo BBN (N-butil-N{4-hidroxibutil}nitrosamina) em ratas Wistar. O total de 125 ratas foi distribuÃdo inicialmente em 14 grupos: I, IIA, IIB, III, IV, V, VI, VII, VIII, IX, X, XI, XII e XIII. Os grupos de I a X receberam BBN por 14 semanas em Ãgua de beber. O grupo I foi tratado com prÃpolis ig 150 mg/kg/peso, por 44 s, iniciado 30 dias antes do inÃcio do BBN. Os grupos IIA, III e VIII foram tratados com prÃpolis (150 mg/kg/peso), por 40s, vias sc e ig iniciada simultaneamente com o BBN. Na 32Âs, os animais dos grupos IV, V, VI, VII e IX, apÃs ultrassonografia, foram estratificados e realocados em 4 grupos K, L, M e N, de forma que cada grupo recebesse o mesmo nÃmero de animais sem lesÃo vesical ou com imagem tumoral pequena, mÃdia e grande. As ratas dos grupos L, M e N, foram tratadas ig com: L-lisina (300mg/kg/peso), celecoxibe (30 mg/kg/peso) e prÃpolis (300 mg/kg/peso) respectivamente, da 32 a 40Âs. Os grupos controles positivos (que receberam apenas BBN) IIB e K foram tratados com Ãgua, via sc e oral, respectivamente, por 40 s. Os grupos controles negativos XI, XII e XIII receberam nesta sequÃncia, prÃpolis (150mg/kg/peso), L-lisina (150 mg/kg/peso) e Ãgua ig por 40 semanas (s). Os grupos III e VIII foram reunidos em um Ãnico grupo, o grupo III. Os animais foram sacrificados ao final da 40Âs. A carcinogÃnese foi estudada em todos os grupos. A angiogÃnese foi avaliada nos grupos K, L, M, N III e X, pela quantificaÃÃo da densidade microvascular em hot spots, atravÃs de imunomarcaÃÃo (CD-31), utilizando-se um programa de computador. O Ãndice de carcinogÃnese (21,00) e a incidÃncia de carcinomas (20%) no grupo I, tratado com prÃpolis 30 dias antes do inÃcio do BBN, foram menores (P<005) que os do grupo controle K (39,67% e 66,67%, respectivamente). A densidade microvascular de hot spot em carcinomas de bexigas foi menor (P<0,05) tanto em ratos tratados com prÃpolis por 40 semanas (grupo III), quanto em tratados com prÃpolis da 32 a 40Âs (grupo N), quando comparada com a densidade dos carcinomas de animais que receberam apenas carcinÃgeno (grupo K). A multiplicidade de carcinomas (P= 0, 00267), o Ãndice de carcinogÃnese (P<0,05) a densidade microvascular (P<0,05) no grupo X (tratado com L-lisina) foram maiores que os do grupo controle K. Somando-se a isso, a incidÃncia de carcinomas no grupo X foi de 100% e apresentando tumores mais invasivos (p= 0, 0039) que os verificados no grupo K. O grupo que recebeu apenas L-lisina nÃo apresentou lesÃes vesicais. Isso significa que a L-lisina por si sà nÃo gera carcinomas. NÃo hà descriÃÃo de efeito promotor da L - lisina na carcinogÃnese de bexiga na literatura pesquisada. A incidÃncia de 100% de carcinomas no grupo tratado com L- lisina pode fazer desta modelo para estudo da carcinogÃnese de bexiga. Conclui-se que o produto de prÃpolis verde administrado diariamente na dose de 150 mg/kg/peso ig, diminui a incidÃncia de carcinomas quando iniciada 30 dias antes do BBN e inibe a angiogÃnese de carcinomas de bexiga na dose de 150 mg/kg/peso quando iniciada simultaneamente ou na dose de 300 mg/kg/peso apÃs a 31 semana do inÃcio de BBN. / The present study evaluated the effects of prolonged, daily intragastric (ig) or subcutaneous (sc) administration of water-soluble derivative of green propolis extracted in L-lysine and of ig administration of L-lysine upon Wistar rat bladder carcinomas angiogenesis and bladder carcinogenesis induced with BBN (N-butyl-N-[4-hydroxybutyl] nitrosamine). At baseline 125 rats were distributed in 14 groups (I, IIA, IIB, III, IV, V, VI, VII, VIII, IX, X, XI, XII and XIII). Groups I through X received BBN in drinking water for 14 weeks. Group I was treated with propolis ig (150 mg/kg body weight) during 44 weeks beginning 30 days before challenge with BBN. Groups IIA, III and VIII were treated for 40 weeks with propolis (150 mg/kg) sc and ig initiated concurrently with BBN. By the 32nd week, the animals in Groups IV, V, VI, VII and IX were ultrasound-scanned, stratified and reallocated into 4 groups (K, L, M and N) so that the groups contained the same number of animals with small, medium and large tumors or without lesions. Groups L, M and N were treated with L-lysine ig (300mg/kg), celecoxib (30 mg/kg) and propolis (300 mg/kg), respectively, from the 32nd to the 40th week. Groups IIB and K (positive control groups receiving BBN only) were treated with water sc and orally, respectively, during 40 weeks. Groups XI, XII and XIII (negative control groups) received propolis (150mg/kg), L-lysine (150 mg/kg) and water ig, respectively, for 40 weeks. Groups III and VIII were merged into a single group (Group III). The animals were euthanized after 40 weeks. Carcinogenesis was studied in all groups. Angiogenesis was evaluated for Groups K, L, M, N, III and X using quantifying microvascular density of hot spots in histological sections stained with the marker CD-31 and analyzed with specific software. The carcinogenesis index (21.00) and the carcinoma incidence (20%) in Group I (treated with propolis 30 days prior to challenge with BBN) were smaller (p<0.05) than for Group K (control; 39.67 and 66.67%, respectively). The microvascular density of bladder carcinoma hot spots was smaller (p<0.05) for rats treated with propolis for 40 weeks (Group III) and rats treated with propolis from the 32nd to the 40th week (Group N) than for rats receiving BBN only (Group K). Carcinoma multiplicity (p=0.00267), carcinogenesis index (p<0.05) and microvascular density (p<0.05) were greater for Group X (treated with L-lysine) than for group K. In addition, the carcinoma incidence in Group X was 100%, and tumors were more invasive (p=0.0039) than in Group K. The group receiving only L-lysine presented no vesical lesions, indicating that L-lysine in itself does not generate carcinomas. Our review of the literature identified no reports of L-lysine acting as a promoter of bladder carcinogenesis. However, the 100% carcinoma incidence observed in the group treated with L-lysine suggests the amino acid may serve as a model for the study of carcinogenesis. In conclusion, daily ig administration of water-soluble derivative of green propolis at 150 mg/kg body weight reduced the incidence of carcinoma when initiated 30 days prior to challenge with BBN, and inhibited angiogenesis in bladder carcinoma at 150 mg/kg when initiated concurrently with BBN or when administered at 300 mg/kg after 31a week of the initiate BBN.

Assim como tecidos normais, tumores possuem uma demanda de nutrientes e oxigênio, suprida através da vasculatura a eles associada que resulta do processo de angiogênese. Fatores pró-angiogênicos são capazes de atrair monócitos, os quais se diferenciam em macrófagos associados a tumores (TAMs). TAMs comumente apresentam fenótipo M2, cujas características são consideradas pró-tumorais, como a promoção da angiogênese e a degradação de matriz extracelular. Estudos indicam que galectina-3 (gal-3), uma proteína pleiotrópica que se liga a ?-galactosídeos, participa do controle da angiogênese e da infiltração de macrófagos M2 na massa tumoral, mas pouco se sabe sobre os mecanismos envolvidos. No presente estudo, utilizamos um modelo de sarcoma induzido por carcinógeno em camundongos selvagens (WT) e knockout para gal-3 (Gal- 3 KO). Comparando os tumores de animais WT e Gal-3 KO, não observamos diferenças no padrão de crescimento tumoral, na área necrótica relativa, na proliferação celular e na quantificação de fibras de colágeno. Demonstramos que, embora ambos os grupos desenvolvam tumores, a angiogênese foi inibida em um microambiente desprovido de gal-3. Entretanto, não houve diferença na produção do fator de crescimento endotelial vascular (VEGF). As imagens obtidas in vivo indicaram que gal- 3 também influencia na formação estrutural de vasos adjacentes ao tumor. Além de mediar aspectos morfológicos relacionados à angiogênese, demonstramos que gal-3 também contribuiu para a funcionalidade vascular, pois houve uma redução na velocidade de fluxo sanguíneo nos vasos intratumorais de animais Gal-3 KO. Nossos dados sugeriram que há menos macrófagos no tumor que não expressa gal-3 e, dentre os TAMs, há mais M2 em comparação ao tumor gal-3-positivo. A análise do tecido onde o tumor se desenvolve, na fase inicial da tumorigênese, indicou que a ausência de gal-3 está relacionada a uma maior densidade de macrófagos M2. Considerando que a presença maior de macrófagos M2 nos sarcomas gal-3-negativos não resultou em maior produção de VEGF, mas sim na inibição da angiogênese, nossos resultados apontam para uma participação significativa de gal-3 na mediação da angiogênese pelos macrófagos / As well as normal tissues, tumors require nutrients and oxygen, which are supplied by the associated vasculature that results from the process of angiogenesis. Pro-angiogenic factors are able to attract monocytes and they differentiate into tumor-associated macrophages (TAMs). TAMs commonly exhibit M2 phenotype, which has characteristics considered pro-tumoral, such as angiogenesis promotion and degradation of extracellular matrix. Studies show that galectin-3 (gal-3), a pleiotropic ?-galactosidebinding protein, participates in angiogenesis control and M2 macrophage infiltration into the tumor mass, but little is known about the mechanisms involved. In this work, we established a model of carcinogen-induced sarcoma in wild-type (WT) and gal-3 knockout (Gal-3 KO) mice. Comparing tumors from WT and Gal-3 KO animals, there were no differences in the pattern of tumor growth, relative necrotic area, cell proliferation and collagenous fibers. We demonstrated that, although both groups develop tumors, angiogenesis was inhibited in a microenvironment devoid of gal-3. However, there was no difference in the production of vascular endothelial growth factor (VEGF). The images obtained in vivo indicated that gal-3 also influenced the structural formation of vessels adjacent to the tumor. In addition to mediating morphological aspects related to angiogenesis, we demonstrated that gal-3 also contributes to vascular functionality, since there was a reduction in blood flow velocity in intratumoral vessels from Gal-3 KO animals. Our data suggested that there are fewer macrophages in tumors without gal-3 and, among TAMs, there are more M2 compared to gal-3-positive tumors. Analysis of the tissue where the tumor develops, in early stages of tumorigenesis, indicated that the lack of gal-3 is related to an increased density of M2 macrophages. Since the greater number of M2 macrophages in gal-3-negative fibrosarcomas did not result in increased VEGF production, but inhibited angiogenesis, our results suggest a significant role of gal-3 in regulation of angiogenesis by macrophages

There is a growing attention in the synthesis of fructo-oligosaccharides (FOS) due to their excellent bio-functional and health-promoting properties. The current production processes are limited to chemical hydrolysis reactions of plant extracts, which are often associated with several drawbacks. In this study, fructosyltransferase (FTase) and polygalacturonase (PGase) activities, present in a commercial enzyme preparation (Pectinex® Ultra SP-L) sourced from Aspergillus aculeatus, have been separated and fully purified by anion-exchange and sizeexclusion chromatography. The FTase possesses fructosyl transfer activity for FOS synthesis and the PGase has pectin hydrolytic activity. Fructosyltransferase is a single-band protein with a molecular weight of 85 kDa, whereas PGase is a distinct protein of 40 kDa. The temperature and pH optima of FTase were 60 ºC and 6.0, with a half-life of 8 h; while that for PGase were 40 ºC and 6.0, respectively. FTase was slightly inhibited in the presence of Ni²⁺, Mg²⁺ and urea; but PGase was more susceptible to divalent ions such as Ca²⁺, Mg²⁺ and Mn²⁺. The kinetic parameters (Km and Vmax) of FTase for the hydrolysis of β-(2→1) linkages from sucrose were 752.3 mM and 120.5 μmol.min⁻¹.mL⁻¹, respectively; whereas the same parameters for pectin hydrolysis by PGase were 13.0 mg.mL⁻¹ and 263 μmol.min-1.mL⁻¹, respectively. The purified FTase was able to transfer fructosyl residues from sucrose, synthesizing the corresponding chains of FOS. PGase was relatively stable at 40 ºC (t½ > 3 h), depolymerizing the pectin backbone while releasing the inulins from within the chicory roots. Analysis of various mixtures of FOS by mass spectrometry, HPLC and ¹H-NMR was undertaken. Results indicated that MS with electrospray ionization and ¹H-NMR are capable of providing relative quantitative data of the FOS present in the mixtures. The pharmaceutical effects of various sc-FOS (0.5%, v/v) and SCFA (0.3%, v/v) on certain bacterial enzymes (β-glucuronidase, urease and β-glucosidase) associated with the formation of carcinogens were also studied. These enzyme activities were not directly influenced by the sc-FOS, but were found to be remarkably decreased by SCFA, pointing toward the prebiotic effect of FOS in intestinal microflora modulation.

En épidémiologie de la santé au travail, la non prise en compte du genre dans les études peut contribuer à maintenir dans l'invisibilité certaines questions propres à la santé des femmes, telles les risques cancérogènes qu'elles peuvent encourir en milieu professionnel. L’objectif de cette thèse est d'analyser la manière dont les biais liés au genre affectent différentes étapes du processus de production des connaissances épidémiologiques sur les cancers d'origine professionnelle.Le premier biais notable est le nombre limité d’études s’intéressant à l’étiologie des cancers d’origine professionnelle chez les femmes. À travers une revue systématique d’études observationnelles (n= 243) indexées sur PubMed et portant sur le cancer du poumon, nous montrons que les risques cancérogènes restent largement sous-étudiés chez les femmes comparées aux hommes. Dans un deuxième temps, à partir de l’enquête Giscop93, nous avons réalisé une comparaison à l’échelle du poste de travail (n= 7 702) entre une évaluation de l’exposition aux solvants chlorés effectuée par un comité d’expert·e·s et une évaluation effectuée par la matrice emplois-expositions en population générale Matgéné. Nos résultats suggèrent des désaccords (dans les indices d’exposition produits) entre les deux outils, qui varient notamment selon le degré de féminisation du métier évalué. Dans un troisième temps, nous montrons à partir de l’enquête cas-témoins ICARE (cas, n= 2 926 dont 22% de femmes, témoins, n= 3 555 dont 22% de femmes) que le odds ratio de cancer du poumon associé à l’exposition aux solvants chlorés diffère selon le sexe et la catégorie socioprofessionnelle.Cet ensemble de travaux nous a mené à des propositions de pratiques de recherche et de nouvelles méthodes d’analyse et de contrôle des biais de genre dans les études en épidémiologie de la santé au travail. / In occupational epidemiology, failure to take gender into account in the analyses may contribute to conceal certain issues specific to women's health, such as the carcinogenic risks they may incur in the workplace. The aim of this thesis is to analyze how gender-related biases affect different stages of the process of producing epidemiological knowledge on occupational cancers, in particular in the definition of the scope of investigation, the exposure assessment and the statistical modelling.The first significant bias is the limited number of studies assessing the etiology of occupational cancers in women. Through a systematic review of observational studies (n = 243) indexed on PubMed for lung cancer, we show that carcinogenic risks remain largely under-studied in women as compared to men. Secondly, based on the Giscop93 study, we have compared, at the job level (n= 7 702), an assessment of occupational exposure to chlorinated solvents made by an expert panel to an evaluation performed by a general population job-exposure matrix Matgéné. Our results suggest some disagreements (in the exposure indices assigned) between the two methods, notably according to the degree of feminization of the job evaluated. Thirdly, based on the ICARE case-control study (cases, n = 2 926 (22% were women), controls, n = 3 555 (22% were women)), we show that the odds ratio of lung cancer associated with exposure to chlorinated solvents is modified by sex and occupational category.This body of work has led us to proposals for research practices and new methods for the analysis and control of gender bias in occupational epidemiology studies.

We have investigated phase II activation of the food-derived mutagen 2- hydroxyamino-1-methyl-6-phenyl[4,5-b]pyridine (N-OH-PhIP) by cytosolic acetyltransferase, sulfotransferase, and tRNA synthetase/kinase enzymes from human breast tissue. Cytosol from homogenates of mammary gland tissue obtained from breast-reduction surgery or mastectomy was incubated with and without enzyme-specific cofactors, and mutagen binding to calf thymus DNA was quantified by 32P-postlabeling. In addition, microsomal fractions of mammary epithelial cells from some individuals were examined for prostaglandin H synthetase activation of N-OH-PhIP. Our results show that all four enzymes can participate in activating N-OH-PhIP, thus inducing PhIP-DNA adduct formation in human mammary cells. However, not all individuals exhibited all these activities; instead each individual showed a combination of one or more activation pathways. The present findings demonstrate that the human mammary gland has the capacity to metabolically activate a dietary mutagen by several enzyme systems, including acetyltransferase, sulfotransferase, tRNA synthetase/kinase, and prostaglandin hydroperoxidase catalysis.