Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Med Liege ; 75(1): 37-42, 2020 Jan.
Artigo em Francês | MEDLINE | ID: mdl-31920042

RESUMO

OBJECTIVE: Perfluoroalkyl substances (PFAS) are chemicals widely employed in the industry. Long term consequences of the newborns' contamination by PFAS on thyroid function are of concern. The aim of this study is to assess the potential associations between PFAS contamination measured at birth and thyroid function assessed few months later. PFAS levels were previously determined in cord blood from a cohort of newborns recruited in Liege. METHOD: Parents of the children belonging to the first and the fifth quintiles of exposure to PFAS were contacted in order to measure the thyroid stimulating hormone (TSH) levels in their child few months after birth. Twenty-eight children participated in the study. Moreover, we performed a literature review about associations between pre- or perinatal exposure to persistent organic pollutants and thyroid function during early childhood. RESULT: No significant difference was highlighted between both groups of contamination (Mann-Whitney, p-value = 0.91). Literature review highlighted the critical need of new longitudinal data about this problematic. CONCLUSION: Our results suggest that the PFAS levels at birth are not associated with TSH levels later in life. Large scale studies are required to confirm our results.


Assuntos
Poluentes Ambientais , Fluorcarbonetos , Doenças da Glândula Tireoide , Glândula Tireoide , Criança , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Estudos Longitudinais , Gravidez , Doenças da Glândula Tireoide/epidemiologia , Glândula Tireoide/fisiopatologia
2.
Scand J Gastroenterol ; 51(6): 712-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26815198

RESUMO

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are potentially progressive diseases. Few data are available on the prevalence and the factors associated with mild inflammatory bowel diseases (IBD). AIM: Our aim was to assess the natural history of mild CD and mild UC and to identify predictive factors of mild evolution over the long term. METHODS: Retrospective study of IBD patients registered in the database of the university hospital CHU of Liège, Belgium. Mild CD was defined as an inflammatory luminal disease (no stricture, abdominal or perianal fistulae) requiring no immunomodulator (IM), anti-TNF and no surgery. Mild UC was defined as no requirement for IM, anti-TNF and no colectomy. RESULTS: Four hundred and seventy-three CD and 189 UC were included (median follow-up: 13 and 11 years respectively). At 1 year, 147 patients had mild CD. At 5 years and the maximum follow-up, 56% and 13% patients still had mild CD, respectively. At 1 year, 142 patients had mild UC. At 5 years and the maximum follow-up, 72% and 44% still had a mild UC, respectively. Factors associated with long-term mild CD and UC were older age at diagnosis and absence of corticosteroids in the first year. In UC proctitis location was associated with mild UC. CONCLUSIONS: In this cohort, 90% of CD patients and 3/4 of UC with mild disease at 1 year lost their mild disease status over time. An old age at diagnosis was predictive of the persistence of a mild CD and UC.


Assuntos
Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Progressão da Doença , Índice de Gravidade de Doença , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Colite Ulcerativa/terapia , Doença de Crohn/terapia , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
3.
J Assist Reprod Genet ; 32(8): 1233-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26174124

RESUMO

PURPOSE: The aim of this study was to evaluate long-term embryo cryopreservation, utilization, and success rate in patients subjected to gonadotoxic treatments in the context of cancer. METHODS: This is a retrospective study on patients (n = 54) undergoing ovarian stimulation and IVF for fertility preservation between January 1997 and June 2014. Embryos were slow-frozen and stored until the women were cured and able to undergo embryo transfer. RESULTS: Fifty-four women underwent 66 oocyte pick-up procedures in total, and embryos were obtained from 52 of the 54 patients. Four patients died before their frozen embryos could be thawed. Of the remaining 48, 9 women returned to use their embryos, resulting in 6 pregnancies (66% cumulative pregnancy rate), two of which ended in miscarriage. The live birth rate per patient was thus 44% (4/9). The true come-back rate, calculated after applicable exclusions, was found to be 23%. CONCLUSION: IVF followed by embryo freezing is a widely established technique for fertility preservation, but little has been published on the outcomes in cancer patients. While we found the number of good-quality embryos to be lower than in a normal population, the cumulative live birth rate was similar to that achieved with fresh embryos in non-cancer patients. The utilization rate of this fertility preservation method can be considered high.


Assuntos
Criopreservação/métodos , Preservação da Fertilidade/métodos , Fertilização In Vitro/estatística & dados numéricos , Neoplasias , Indução da Ovulação/métodos , Adulto , Blastocisto/fisiologia , Transferência Embrionária/métodos , Feminino , Preservação da Fertilidade/estatística & dados numéricos , Fertilização In Vitro/métodos , Humanos , Neoplasias/terapia , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Adulto Jovem
4.
Hum Reprod ; 24(12): 3108-18, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19726447

RESUMO

BACKGROUND: Cross-border reproductive care indicates the cross-border movements made by patients to obtain infertility treatment they cannot obtain at home. The problem at present is that empirical data on the extent of the phenomenon are lacking. This article presents the data on infertility patients going to Belgium for treatment. METHODS: A survey was conducted among the centres for reproductive medicine that are allowed to handle oocytes and create embryos (B-centres). Data were collected on the nationality of patients and the type of treatment for which they attended during the period 2000-2007. RESULTS: Sixteen of 18 centres responded to the questionnaire. The flow of foreign patients has stabilized since 2006 at approximately 2100 patients per year. The majority of foreign nationals seeking treatment in Belgium were French women for sperm donation. The next highest group was patients entering the country to obtain ICSI with ejaculated sperm. CONCLUSIONS: There are clear indications that numerous movements are motivated by the wish to evade legal restrictions in one's home country, either because the technology is prohibited or because the patients have characteristics, which exclude them from treatment in their own countries.


Assuntos
Infertilidade/terapia , Turismo Médico/estatística & dados numéricos , Serviços de Saúde Reprodutiva/estatística & dados numéricos , Técnicas de Reprodução Assistida/estatística & dados numéricos , Adulto , Bélgica , Feminino , França/etnologia , Pesquisas sobre Serviços de Saúde , Humanos , Inseminação Artificial Heteróloga/estatística & dados numéricos , Masculino , Turismo Médico/tendências , Pessoa de Meia-Idade , Programas Nacionais de Saúde/legislação & jurisprudência , Programas Nacionais de Saúde/estatística & dados numéricos , Países Baixos/etnologia , Seleção de Pacientes , Diagnóstico Pré-Implantação/estatística & dados numéricos , Técnicas de Reprodução Assistida/legislação & jurisprudência , Injeções de Esperma Intracitoplásmicas/estatística & dados numéricos , Adulto Jovem
5.
J Econ Entomol ; 102(2): 616-23, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19449641

RESUMO

Beekeepers suspected maize, Zea mays L., treated with imidacloprid to result in substantial loss of honey bee (Hymenoptera: Apidae) colonies in Belgium. The objective of this study was to investigate the potential impact of maize grown from imidacloprid-treated seeds on honey bee mortality. A survey of 16 apiaries was carried out, and all maize fields treated or not with imidacloprid were located within a radius of 3,000 m around the observed apiaries. Samples of honey, beeswax, and bees were collected in three colonies per apiary and analyzed for pesticide contain by liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry. We first found a significant correlation between the number of colonies per apiary and the mortality rates in an apiary. In addition, this mortality rate was inversely correlated with the surface of maize fields treated and not with imidacloprid, suggesting that this pesticide do not interact with bees' fitness. Moreover, a very large number of our samples contained acaricides either prohibited or ineffective against Varroa destructor (Anderson & Trueman) (Acari: Varroidae), suggesting that the treatment methods used by the beekeepers to be inadequate for mite control. Our results support the hypothesis that imidacloprid seed-treated maize has no negative impact on honey bees.


Assuntos
Abelhas/efeitos dos fármacos , Imidazóis/farmacologia , Inseticidas/farmacologia , Nitrocompostos/farmacologia , Sementes , Zea mays , Animais , Mel/análise , Imidazóis/química , Inseticidas/química , Neonicotinoides , Nitrocompostos/química , Resíduos de Praguicidas/química , Ceras/química
7.
Hum Reprod ; 22(10): 2653-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17670763

RESUMO

Aggressive chemotherapy and radiotherapy generally result in the loss of both endocrine and reproductive functions. In 1990, a woman aged 20 years, presenting with beta-thalassemia major, underwent chemotherapy (busulfan and cyclophosphamide) and total body irradiation (TBI) before bone marrow transplantation (BMT), the donor being her 17-year-old HLA-compatible sister. The treatment resulted in premature ovarian failure. In 2006, after excision of ovarian cortical fragments from the HLA-compatible sister, these fragments were immediately sutured to the ovarian medulla of the patient. Both procedures were performed by laparoscopy. Six months after reimplantation, vaginal ultrasonography and hormone concentrations indicated recovery of ovarian secretion and function. From 6 to 11 months, the patient experienced menstrual bleeding and the development of a follicle concomitant with high estradiol levels. Eleven months after reimplantation, two follicles were detected and punctured under vaginal ultrasonographic control. Two mature oocytes were retrieved and inseminated by ICSI. Two embryos (2- and 3-cell) were obtained. Allotransplantation of fresh ovarian tissue was laparoscopically performed between two genetically non-identical sisters. Restoration of ovarian function was achieved after six months. Oocyte retrieval and embryo development were demonstrated.


Assuntos
Ovário/transplante , Insuficiência Ovariana Primária/cirurgia , Adolescente , Adulto , Bussulfano/efeitos adversos , Terapia Combinada , Ciclofosfamida/efeitos adversos , Feminino , Humanos , Recuperação de Oócitos , Ovário/fisiologia , Insuficiência Ovariana Primária/etiologia , Irmãos , Injeções de Esperma Intracitoplásmicas , Transplante Homólogo , Irradiação Corporal Total/efeitos adversos , Talassemia beta/terapia
8.
J Chromatogr A ; 1152(1-2): 116-23, 2007 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-17416380

RESUMO

We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid-liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CCalpha and CCbeta (0.0002-0.943 ng g(-1) for CCalpha, and 0.0002-1.232 ng g(-1) for CCbeta) show the good sensitivity attained by this multi-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure.


Assuntos
Cromatografia Líquida/métodos , Mel/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Hum Reprod ; 21(7): 1894-900, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16556673

RESUMO

BACKGROUND: The aim of the study was to investigate whether intranasal (IN) administration of a GnRH agonist could provide luteal support in IVF/ICSI patients. METHODS: Controlled ovarian hyperstimulation (COH) was performed using hMG/FSH and a GnRH antagonist. Patients were then randomly allocated to either 10,000 IU hCG, followed by vaginal administration of micronized progesterone (3x 200 mg/day) (group A), or 200 microg IN buserelin followed by either 100 microg every 2 days (group B), or 100 microg every day (group C), or 100 microg twice a day (group D), or 100 microg three times a day (group E). Luteal support was continued for 15 days. RESULTS: Twenty-three patients were randomized. Groups B and C were discontinued prematurely in view of the short luteal phase. The luteal phase was significantly shorter in groups B, C and D, whereas group E was comparable with group A, 13.5 and 13.0 days, respectively. In the mid-luteal phase, median progesterone levels were significantly lower in groups B, C and D, whereas group E was comparable with group A, 68.9 and 98.0 ng/ml, respectively. Estradiol (E2) was significantly reduced in groups B and D but sustained in group E. In the hCG group, LH levels were undetectable (<0.1 IU/l), whereas LH was detectable and significantly higher in groups C, D and E. Two pregnancies were obtained in the hCG group (two of five), one ectopic and one ongoing. Three pregnancies were obtained in group E, one miscarriage and two ongoing twin pregnancies (three of five). CONCLUSION: IN administration of buserelin may be effective in triggering follicular maturation and providing luteal phase support in patients undergoing assisted reproduction techniques (ART).


Assuntos
Busserrelina/administração & dosagem , Fertilização In Vitro/métodos , Hormônio Liberador de Gonadotropina/agonistas , Fase Luteal/efeitos dos fármacos , Administração Intranasal , Administração Intravaginal , Adulto , Gonadotropina Coriônica/uso terapêutico , Estradiol/sangue , Feminino , Humanos , Hormônio Luteinizante/sangue , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/fisiologia , Projetos Piloto , Gravidez , Taxa de Gravidez , Progesterona/administração & dosagem , Progesterona/sangue , Injeções de Esperma Intracitoplásmicas/métodos
10.
Hum Reprod ; 21(6): 1408-15, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16537563

RESUMO

BACKGROUND: The aim of this study was to assess the non-inferiority of an oral contraceptive (OC)-pretreated cetrorelix regimen and a buserelin regimen in IVF/ICSI patients treated with r-hFSH in terms of total number of oocytes retrieved. METHODS: Multicentre, randomized study. One hundred and eighty two patients were randomized to receive cetrorelix with OC pretreatment (n = 91) or to receive buserelin (n = 91). The cetrorelix group started with daily OCs on cycle day 5 and continued for 21-28 days. Cetrorelix (0.25 mg) was given daily from stimulation day 6 up to and including the day of r-hCG administration. The buserelin group started with buserelin (500 microg/day) for at least 10 days until down-regulation was achieved, after which the dose was reduced to daily 200 microg up to and including the day of r-hCG administration. r-hFSH was started in both groups on a Friday, in the cetrorelix group 5 days after the last OC pill intake. Both regimens were followed by a standard IVF or ICSI procedure. The primary efficacy endpoint was the number of oocytes retrieved per patient. RESULTS: Number of oocytes, cancellation rates, r-hFSH requirements, number of oocyte retrievals during the weekend or public holiday and number of pregnancies were similar in both groups. Both treatment regimens were well tolerated. CONCLUSIONS: Cetrorelix pretreated with OCs resulted in similar number of oocytes retrieved compared with a long buserelin protocol. Both regimens were well tolerated and allowed scheduling of the oocyte retrieval, with only small number of retrievals falling on a weekend or public holiday.


Assuntos
Fertilização In Vitro/métodos , Hormônio Liberador de Gonadotropina/análogos & derivados , Injeções de Esperma Intracitoplásmicas/métodos , Adolescente , Adulto , Busserrelina/uso terapêutico , Anticoncepcionais Orais/uso terapêutico , Feminino , Hormônio Liberador de Gonadotropina/uso terapêutico , Antagonistas de Hormônios/uso terapêutico , Humanos , Oócitos/metabolismo , Folículo Ovariano , Indução da Ovulação/métodos , Gravidez
11.
Hum Reprod ; 21(1): 183-8, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16126712

RESUMO

Ovarian function after orthotopic transplantation of cryopreserved ovarian tissue has been restored in women with malignant disease. Here the techniques are adapted for a non-cancer patient. In 1999, right oophorectomy was performed in a 21 year old woman before chemotherapy, prior to bone marrow transplantation. Ovarian cortex was frozen, according to a strict protocol. After thawing, ovarian cortex was reimplanted into the ovary and in a peritoneal window close to the ovary in 2004. Four-and-a-half months after reimplantation, LH, FSH, 17beta-estradiol and progesterone levels, as well as ultrasonography, demonstrated the presence of an ovulatory cycle. After this cycle, the patient experienced two other ovulatory cycles, evidenced by FSH and 17beta-estradiol concentrations, as well as ultrasound demonstration of a follicle. Follicular development was clearly observed in both the intraovarian site (1st and 2nd cycle) and the peritoneal window (3rd cycle). Restoration of endocrine ovarian function occurred after ovarian cortical strips, biopsied and cryopreserved before chemotherapy, were reimplanted into the ovary itself and a periovarian peritoneal window.


Assuntos
Anemia Falciforme/tratamento farmacológico , Criopreservação , Ovário/fisiologia , Ovário/cirurgia , Insuficiência Ovariana Primária/cirurgia , Reimplante , Adulto , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Ovário/diagnóstico por imagem , Insuficiência Ovariana Primária/induzido quimicamente , Progesterona/sangue , Transplante de Tecidos , Transplante Autólogo , Ultrassonografia
12.
Hum Reprod ; 20(7): 1798-804, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15890740

RESUMO

BACKGROUND: The study objective was to investigate whether repeated intranasal administration of a GnRH agonist could provide convenient and safe luteal support. METHODS: Twenty-four patients with unexplained infertility were enrolled. All patients were treated with an aromatase inhibitor. When ovulation trigger criteria were met, patients were randomly allocated to either 5000 IU hCG (group A), or 200 microg intranasal buserelin followed by 100 microg every 3 days (group B), 100 microg every 2 days (group C), or 100 microg every day (group D), up to day 14 of the luteal phase. All patients underwent intrauterine insemination. RESULTS: Follicular development was similar in all groups with 1.1 +/- 0.3 follicles > or = 16 mm, 229.4 +/- 95.2 pg/ml estradiol (E2) and 0.8 +/- 0.5 ng/ml progesterone (mean+/-SD). The luteal phase duration (median; 95% confidence interval) was 15 (14.1, 15.0), 14 (12.5, 15.5), 15 (11.8, 18.2) and 15 (14.4, 15.6) days in groups A, B, C and D respectively. From luteal phase day 7 onwards, progesterone levels tended to be higher in group D compared with A. On day 14 of the luteal phase, progesterone levels were 3.0 (0.8, 5.2), 1.7 (-0.5, 3.9), 3.9 (-0.7, 8.5) and 7.7 (3.4, 11.9) ng/ml in groups A, B, C and D respectively (P = 0.045). No pregnancy was recorded in group A, but there was one biochemical pregnancy in group B, one biochemical and one singleton clinical pregnancy in group C, and two singleton clinical pregnancies in group D. CONCLUSION: Intranasal administration of buserelin could be effective to provide luteal support. This treatment was associated with a good pregnancy rate (5/18, 28%).


Assuntos
Busserrelina/administração & dosagem , Manutenção do Corpo Lúteo/efeitos dos fármacos , Fármacos para a Fertilidade Feminina/administração & dosagem , Hormônio Liberador de Gonadotropina/agonistas , Administração Intranasal , Adulto , Gonadotropina Coriônica/administração & dosagem , Manutenção do Corpo Lúteo/sangue , Estradiol/sangue , Feminino , Humanos , Fase Luteal/sangue , Fase Luteal/efeitos dos fármacos , Hormônio Luteinizante/sangue , Masculino , Indução da Ovulação , Gravidez , Progesterona/sangue , Técnicas de Reprodução Assistida
13.
Lancet ; 364(9443): 1405-10, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15488215

RESUMO

BACKGROUND: The lifesaving treatment endured by cancer patients leads, in many women, to early menopause and subsequent infertility. In clinical situations for which chemotherapy needs to be started, ovarian tissue cryopreservation looks to be a promising option to restore fertility. In 1997, biopsy samples of ovarian cortex were taken from a woman with stage IV Hodgkin's lymphoma and cryopreserved before chemotherapy was initiated. After her cancer treatment, the patient had premature ovarian failure. METHODS: In 2003, after freeze-thawing, orthotopic autotransplantation of ovarian cortical tissue was done by laparoscopy. FINDINGS: 5 months after reimplantation, basal body temperature, menstrual cycles, vaginal ultrasonography, and hormone concentrations indicated recovery of regular ovulatory cycles. Laparoscopy at 5 months confirmed the ultrasonographic data and showed the presence of a follicle at the site of reimplantation, clearly situated outside the ovaries, both of which appeared atrophic. From 5 to 9 months, the patient had menstrual bleeding and development of a follicle or corpus luteum with every cycle. 11 months after reimplantation, human chorionic gonadotrophin concentrations and vaginal echography confirmed a viable intrauterine pregnancy, which has resulted in a livebirth. INTERPRETATION: We have described a livebirth after orthotopic autotransplantation of cryopreserved ovarian tissue. Our findings suggest that cryopreservation of ovarian tissue should be offered to all young women diagnosed with cancer.


Assuntos
Criopreservação , Doença de Hodgkin/tratamento farmacológico , Ovário/transplante , Gravidez , Transplante de Tecidos , Adulto , Antineoplásicos/efeitos adversos , Feminino , Humanos , Recém-Nascido , Infertilidade Feminina/induzido quimicamente , Infertilidade Feminina/prevenção & controle , Insuficiência Ovariana Primária/induzido quimicamente , Transplante Autólogo
14.
Chemosphere ; 54(1): 137-42, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14559266

RESUMO

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food samples collected in Belgium, Switzerland, Czech Republic, United States of America and Australia. PCDD/F and PCB concentrations for the four investigated types of meals were very low. PCDD/F values ranged from non-detected to 1.40 pg WHO-TEQ/g fat and from 0.79 to 2.08 pg WHO-TEQ/g fat for lower and upper bound, respectively. Major contributors to the PCDD/F TEQ were 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The relative contribution of PCBs to the total TEQ was 68%. For adults, an average estimated intake was 6.7 pg WHO-TEQ/kg bw/month, including consumption of all types of analyzed meals, representing 9.5% of the PTMI. For child, a value of 14.5 pg WHO-TEQ/kg bw/month was obtained, representing 20.6% of the PTMI.


Assuntos
Benzofuranos/análise , Análise de Alimentos , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Austrália , Dibenzofuranos Policlorados , Ingestão de Alimentos , Europa (Continente) , Humanos , Estados Unidos
15.
Chemosphere ; 52(4): 725-33, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12738286

RESUMO

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 35 samples of commercial long-life pasteurised cows' milk issued from eight different brands available in Walloon supermarkets (Belgium). The observed congener profile was characteristic of milk samples issued from industrialised countries with good inter and intra-brand reproducibility's. The PCDDs to PCDFs ratio was equal to 1.8 in concentration. The toxic equivalent (TEQ based on WHO-TEF) value for PCDD/Fs in all analysed milks was 1.09+/-0.30 pg TEQ/g fat (range 0.86-1.59), which is below the recommended EU non-commercialisation threshold value of 3 pg TEQ PCDD/Fs/g of milk fat. The mean TEQ value including cPCBs was 2.23+/-0.55 pg TEQ/g fat. These PCBs actually contributed for 49+/-8.6% of the total TEQ. Among PCDD/Fs and cPCBs, tetrachloro dibenzo-p-dioxin (TCDD), pentachloro dibenzo-p-dioxin (PeCDD), pentachloro dibenzofurans (PeCDFs) and 3,3',4,4',5-pentachloro biphenyl (PCB-126) were the most important contributors to the TEQ. Estimated daily intake (EDI) due to consumption of such milks was 0.34 pg TEQ/kg of body weight/day for PCDD/Fs and 0.69 pg TEQ/kg of body weight/day when cPCBs were included.


Assuntos
Benzofuranos/análise , Leite/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Animais , Bélgica , Bovinos , Coleta de Dados , Dibenzofuranos Policlorados , Europa (Continente) , Conservação de Alimentos/métodos
16.
Chemosphere ; 48(8): 763-70, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12222769

RESUMO

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 20 non-pooled breast milk samples collected in or close to an industrial area of Wallonia (Belgium). PCDD/F concentrations ranged between 16.0 and 52.1 pg TEQ/g fat, with a mean value of 29.4 pg TEQ/g fat. If coplanar PCBs (77, 126, 169) are included in TEQ calculations, levels ranged between 22.2 and 100.2 pg TEQ/g fat, with a mean value of 40.8 pg TEQ/g fat. It appears that 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126 account for more than 90% of the TEQ. Estimated PCDD/F dietary intake is 76 pg TEQ/kg body weight (bw)/day. This value is almost 20 times higher than the World Health Organization tolerable daily intake. A value of 103 pg TEQ/kg bw/day represents the intake of PCDDs, PCDFs and cPCBs (no mono-ortho PCBs included).


Assuntos
Benzofuranos/análise , Poluentes Ambientais/análise , Bem-Estar do Lactente , Leite Humano/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , Adulto , Bélgica , Dibenzofuranos Policlorados , Feminino , Humanos , Recém-Nascido , Gravidez , Valores de Referência , Organização Mundial da Saúde
17.
Chemosphere ; 48(2): 167-79, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12117051

RESUMO

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 197 foodstuffs samples of animal origin from Belgium during years 2000 and 2001. All investigated matrices (except horse) present background levels lower than the Belgian non-commercialization value of 5 pg TEQ/g fat. Pork was the meat containing the lowest concentration of both PCDD/Fs and cPCBs. The mean background concentration of 2,3,7,8-TCDD toxicity equivalent in milk was 1.1 pg/g of fat, with a congener distribution typical of non-contaminated milk. The relative contribution of 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF to the PCDD/Fs TEQ was 85+/-7.9% for all investigated matrices. The cPCBs contribution to the total TEQ was 47+/-19.0% for products of terrestrial species and 69+/-20.0% for aquatic species. Once the contribution of cPCBs was added to the TEQ, few foodstuffs such as horse, sheep, beef, eggs and cheese presented levels above the future European guidelines that currently only include PCDD/Fs but will be re-evaluated later in order to include 'dioxin-like' PCBs. Based on levels measured in the samples, the estimation of the dietary intake was 65.3 pg WHO-TEQ/day for PCDD/Fs only (1.00 pg WHO-TEQ/kg bw/day, for a 65 kg person) and 132.9 pg WHO-TEQ/day if cPCBs were included (2.04 pg WHO-TEQ/kg bw/day, for a 65 kg person). Meat (mainly beef), dairy products, and fish each account for roughly one third of the intake.


Assuntos
Benzofuranos/análise , Poluentes Ambientais/análise , Contaminação de Alimentos , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , Bélgica , Dibenzofuranos Policlorados , Dieta , Ovos , Guias como Assunto , Humanos , Carne , Saúde Pública , Medição de Risco , Alimentos Marinhos
18.
J Chromatogr A ; 925(1-2): 207-21, 2001 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-11519807

RESUMO

A fast clean-up procedure for the low level analysis of polychlorinated dibenzo-p-dioxins. polychlorinated dibenzofurans and coplanar polychlorinated biphenyls in highly fatty biological matrices using high capacity disposable multi-layer silica columns is presented. Results were compared with gel permeation chromatography for removal of lipids. Analytical criteria such as recovery rates, repeatability, reproducibility and robustness are evaluated through a broad range of biological matrices and reference materials analysis. The final proposed procedure for the complete analysis, including pressurized liquid extraction, Power-Prep system clean-up and GC-high-resolution MS analysis requires only 48 h, and allows the simultaneous preparation of up to 10 samples.


Assuntos
Benzofuranos/análise , Gorduras/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Cromatografia em Gel , Controle de Qualidade , Padrões de Referência , Reprodutibilidade dos Testes
19.
Environ Sci Technol ; 35(8): 1616-23, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11329711

RESUMO

Fly ash, collected in the electrostatic precipitator of a sinter plant in Belgium, has been examined and characterized in terms of its behavior with respect to thermal polychlorodibenzo-p-dioxins (PCDD) and polychlorodibenzofurans (PCDF) formation. Thermal experiments of the fly ash were conducted in a flow of air. The temperature was varied from 250 to 450 degrees C, and the reaction time varied from 30 min to 6 h. For comparison, the oxidative degradation of carbon in the fly ash was studied by differential scanning calorimetry (DSC) in the temperature range from 50 to 500 degrees C. Besides the known maximum of formation of PCDD/Fs around 325 degrees C generally found on experiments with incinerator fly ash, a second maximum of formation around 400 degrees C is observed on the sinter fly ash used in this study. DSC measurements on the fly ash show that the oxidative degradation of carbon appears at these two different temperatures confirming that the de novo synthesis on this kind of fly ash take place at two different optimum temperatures. About the reaction time, already after 30 min, an important quantity of PCDD/Fs is formed; the fast increase in PCDD/Fs amount is followed by a slower formation rate between 2 and 4 h. At longer reaction time, the formation slows down, and decomposition reactions become important. Analysis of homologue distribution indicates that the profile of PCDD/Fs is independent of the reaction time but that an increase of the temperature leads to a rise of lower chlorinated species. In all experiments, PCDF are formed preferentially (total PCDF/PCDD ratios larger than 5). The PCDF/PCDD ratio is clearly independent of the reaction time. Concerning the temperature, the apparently better stability of PCDF at high temperature (PCDF/PCDD ratio higher at high temperature) results in the fact of different PCDF/PCDD ratios for the different family and modifications of homologue distribution with the temperature. The isomer distribution shows little reaction time or temperature dependency, which is an argument in favor of a thermodynamic control of the isomer distribution during de novo formation of PCDD/Fs. Differences within the isomer distribution patterns of PCDD/Fs obtained from the laboratory de novo synthesis experiments and the original fly ash, reflecting the formation under the industrial process, suggest a different mechanism of formation in the sinter plant for the PCDD and PCDF. The de novo synthesis is sufficient to explain the PCDF formation in the real process, but synthesis from precursors must play a role for the PCDD formation.


Assuntos
Benzofuranos/síntese química , Carbono , Resíduos Industriais , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/síntese química , Polímeros/síntese química , Varredura Diferencial de Calorimetria , Cinza de Carvão , Cinética , Material Particulado , Termodinâmica , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA