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1.
Z Gastroenterol ; 50(10): 1083-8, 2012 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-23059801

RESUMO

Immunochemical stool blood tests have a significantly higher sensitivity for the detection of advanced neoplasia and colorectal cancer. Based on national and international studies it has been required to include them into the national cancer screening programme in Germany also. The sensitivity (detection limit) can be set by the manufacturer in order to achieve an optimal and balanced result between sensitivity and specificity. The present study was conducted with 639 patients who have undergone both the screening colonoscopy, as well as the immunochemical stool blood test. The test "immoCARE-C" provided by the company CARE diagnostica Laborreagenzien GmbH was used in the study. The test has been evaluated with seven levels of detection limits between 500  ng/mL and 25  ng/mL. The best sensitivity for detection of advanced lesions was demonstrated by a cut-off of 50 ng/mL and 25  ng/mL. The specificity did not fall below 90  %. These positive results lead to considerations to organise a primary access to such tests in the prevention of colorectal cancer as a kind of filter before offering the screening colonoscopy.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/prevenção & controle , Fezes/química , Programas de Rastreamento/estatística & dados numéricos , Sangue Oculto , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e Especificidade
2.
Int J Vitam Nutr Res ; 79(2): 87-94, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20108210

RESUMO

Carotenoids are colored molecules that are widespread in the plant kingdom, but animals cannot synthesize them. Carotenes are long, apolar molecules which require fully functioning digestive processes to be absorbed properly. Hence they could be interesting markers of intestinal absorption and digestion. Indeed, only few tests are available to assess these processes and only the D-xylose tolerance test is routinely used. However D-xylose is a sugar that tests only the absorption of water-soluble compounds and it only tests duodenal absorption. In this study, we have evaluated carotenoids as markers of digestion and absorption. We compared fasting plasma carotenoids concentrations in 21 control subjects, 20 patients with Crohn's disease, and 18 patients with pancreatic cancer. Crohn's disease alters intestinal absorption while pancreatic cancer decreases pancreatic enzyme secretion thus impairing digestion. Results show that all carotenoids are significantly lower in Crohn's and cancer patients as compared to control subjects and the multifactorial analysis shows that this decrease is mostly independent of dietary intake. Interestingly, maldigestion as seen in pancreatic cancer more strongly influences plasma lutein and lycopene concentrations while malabsorption in Crohn's disease acts on other carotenoids. Thus carotenoids could be interesting alternatives for testing and following patients that are suspected of having malabsorption or maldigestion syndromes.


Assuntos
Carotenoides/sangue , Doença de Crohn/sangue , Ileíte/sangue , Neoplasias Pancreáticas/sangue , Adulto , Idoso , Biomarcadores/sangue , Dieta , Digestão , Feminino , Humanos , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Caracteres Sexuais , Inquéritos e Questionários
3.
Eur J Clin Nutr ; 60(6): 706-17, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16391586

RESUMO

OBJECTIVES: The data was collected during the inclusion step of the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study. This article deals with the study's first stage before any supplementation. The collected data shows factors influencing blood vitamin concentrations and may reflect the vitamin status of volunteers. MATERIAL AND METHODS: A total of 12,741 volunteers were enrolled in the SU.VI.MAX study 7,713 women 35-60 years of age and 5,028 men 50-60 years of age. The serum concentrations of retinol, alpha-tocopherol, and beta-carotene were measured by HPLC, and vitamin C concentration was measured by spectrofluorimetry using a Technicon continuous flow analysis apparatus. The volunteers recorded their 24 h diet by means of a specific terminal that was connected to the main central computer of the SU.VI.MAX study. Volunteers recorded the food they consumed daily and estimated its quantity by comparing pictures of dishes. RESULTS: Retinol concentration was significantly higher in older volunteers, and was higher in male than in female volunteers. Smoking had no effect on serum retinol, but the latter was higher in the autumn than in the winter. Serum retinol concentrations were higher in the Southwest region and lower in the Ile-de-France and East-Centre regions. Serum alpha-tocopherol was slightly higher in older volunteers and also higher in male volunteers. Serum alpha-tocopherol was significantly lower in smokers, and former smokers showed intermediate levels. Like retinol, serum alpha-tocopherol was higher in the autumn, and higher in the Southwest as compared to the East-Centre Serum beta-carotene was slightly higher in younger volunteers, and concentrations were higher in female than in male volunteers. Tobacco smoking decreased serum beta-carotene, which was higher in the autumn, and higher in the East, West, and North regions. Serum vitamin C was higher in female volunteers, and was not age related. Serum vitamin C was lower in smokers, was season-dependant, but contrary to fat-soluble vitamins, concentrations were higher in the winter and spring. Serum vitamin C was higher in the Southeast and East-Centre, but lower in the North region. CONCLUSION: These results suggest that serum retinol concentrations depend on gender, age, seasons, and location of residence. Similarly, serum alpha-tocopherol concentrations were slightly influenced by age, but more by tobacco smoking, seasons, dietary intake, and location of residence. Serum concentrations of beta-carotene depend on gender, age, smoking status, dietary intake, and location of residence. Serum vitamin C concentrations depend on gender, age, smoking status, seasons, dietary intake, and location of residence. Contrary to beta-carotene, retinol concentrations were higher in male than in female volunteers. Such a reversed relation suggests a higher beta-carotene-retinol conversion in male volunteers.


Assuntos
Antioxidantes/metabolismo , Ácido Ascórbico/sangue , Dieta , Vitamina A/sangue , alfa-Tocoferol/sangue , beta Caroteno/sangue , Adulto , Fatores Etários , Análise de Variância , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Cromatografia Líquida de Alta Pressão/métodos , Demografia , Registros de Dieta , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Estações do Ano , Fatores Sexuais , Fumar , Vitamina A/administração & dosagem , alfa-Tocoferol/administração & dosagem , beta Caroteno/administração & dosagem
4.
Eur J Clin Nutr ; 59(10): 1181-90, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16034362

RESUMO

OBJECTIVE: To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc. METHODS: Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35-60 y and 1307 men aged 45-60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study. RESULTS: Women had higher baseline serum beta-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum beta-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum beta-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum beta-carotene and higher selenium concentrations. Serum beta-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary beta-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum beta-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively. CONCLUSION: Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients.


Assuntos
Antioxidantes/metabolismo , Dieta , Obesidade/sangue , Oligoelementos/sangue , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas/sangue , Antioxidantes/administração & dosagem , Antioxidantes/análise , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/sangue , Análise Química do Sangue , Ingestão de Energia , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Selênio/administração & dosagem , Selênio/sangue , Fatores Sexuais , Fumar/sangue , Oligoelementos/administração & dosagem , Oligoelementos/análise , Vitamina E/administração & dosagem , Vitamina E/sangue , Zinco/administração & dosagem , Zinco/sangue , beta Caroteno/administração & dosagem , beta Caroteno/sangue
5.
Mutat Res ; 558(1-2): 75-80, 2004 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-15036121

RESUMO

This study was undertaken with the aim to develop an optimised protocol for the evaluation of DNA damage in frozen whole blood. This was achieved by use of the single-cell gel electrophoresis (SCGE) or comet assay in its alkaline version. After collection of blood, the total blood sample was mixed with dimethyl sulfoxide (DMSO), a cryoprotectant commonly used for prevention of freezing-induced damage to living cells, and then stored at -80 degrees C. We observed no statistically significant differences in the level of DNA damage between fresh blood samples and frozen blood samples, as assessed by the comet assay. Considering the absence of effects of the freezing step, a frozen blood sample was included as a control sample in subsequent experiments. Thus the protocol was applied to blood samples of twenty healthy subjects including smokers and non-smokers. The comparative analysis indicated that the level of DNA damage was 56% higher in smokers than in non-smokers (P = 0.01). Altogether, this study strongly suggests that frozen whole blood could be utilised in association with the comet assay in human epidemiological bio-monitoring for the assessment of genetic damage in populations at risk.


Assuntos
Sangue , Ensaio Cometa , Dano ao DNA , Fumar/sangue , Estudos de Casos e Controles , Congelamento , Humanos
8.
Cancer Detect Prev ; 25(5): 479-85, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11718454

RESUMO

The "SUpplementation en VItamines et Minéraux AntioXidants" (SU.VI.MAX) study is a randomized double-blind, placebo controlled, primary-prevention trial designed to test the efficacy of a daily supplementation with antioxidant vitamins (vitamin C, 120 mg; vitamin E, 30 mg; and beta-carotene, 6 mg) and minerals (selenium, 100 microg; and zinc, 20 mg) at nutritional doses (one to three times the daily recommended dietary allowances), in reducing the frequency of cancers and cardiovascular diseases. The study involves 12,735 eligible subjects (women aged 35-60 years, men aged 45-60 years) included in 1994 in France. They will be followed up for 8 years. The targeted population is the general population. The aim of this specific analysis is to assess the effect of 2 years of supplementation on biochemical indicators of vitamin and trace element on a subsample of 1000 subjects. The mean (+/- standard deviation) concentrations of plasma beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc among participants who were randomly assigned to receive a daily supplementation with beta-carotene, vitamin E, vitamin C, selenium and zinc for 2 years were significantly higher than those who were assigned to receive placebo. Specifically, the mean concentrations among men in the intervention group were 0.86 +/- 0.70 micromol/L for beta-carotene, 35.3 +/- 9.3 micromol/L for alpha-tocopherol, 11.5 +/- 4.7 microg/ mL for vitamin C, 1.65 +/- 0.33 micromol/L for selenium, and 16.2 +/- 3.9 micromol/L for zinc. The mean concentrations among women in the intervention were 1.25 +/- 0.90 micromol/L for beta-carotene, 34.9 +/- 8.4 micromol/L for alpha-tocopherol, 12.6 +/- 4.0 microg/mL for vitamin C, 1.68 +/- 0.37 micromol/L for selenium, and 15.3 +/- 3.9 micromol/L for zinc. The values observed for beta-carotene and vitamin E in the supplementation group after 2 years of intervention are those that have been associated with the lowest risk of cancer in observational studies. They are definitely lower than concentrations reported in intervention studies showing an apparent negative effect of high levels of beta-carotene supplementation on the lung cancer incidence rate in high-risk subjects (initial level multiplied by 12-18). Data from the follow-up will ascertain if any plausible reduction in the incidence rate of cancers may be associated with such amounts of antioxidant agents.


Assuntos
Antioxidantes/administração & dosagem , Biomarcadores/sangue , Oligoelementos/administração & dosagem , Oligoelementos/sangue , Vitaminas/administração & dosagem , Vitaminas/sangue , Adulto , Ácido Ascórbico/sangue , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Selênio/sangue , Zinco/sangue , alfa-Tocoferol/sangue , beta Caroteno/sangue
9.
J Physiol Anthropol Appl Human Sci ; 20(2): 81-4, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11385942

RESUMO

Selenium is an essential trace element which is part of the active site of seleno-dependent glutathione peroxidase and type 1 deiodinase. Therefore, it plays a key role in thyroid hormone metabolism. The present work was undertaken in order to evaluate selenium status in two Ivory Coast populations: the first with high (Glanlé) and the second with low (Abidjan) prevalence of iodine deficiency. Selenium, glutathione peroxidase, glutathione reductase, glutathione and diglutathione were determined in blood and/or urine. In plasma and erythrocytes, selenium and glutathione peroxidase were dramatically low in Glanlé. Compared to Abidjan, selenium, glutathione peroxidase, vitamin E and riboflavin status were decreased whereas diglutathione was increased in Glanlé. The results clearly demonstrate a selenium deficiency and suggest an oxidant stress in Glanlé. Causes and consequences of this selenium deficiency and oxidant stress remain to be determined.


Assuntos
Iodo/deficiência , Selênio/deficiência , Antropologia Cultural , Côte d'Ivoire , Glutationa/sangue , Glutationa/urina , Glutationa Peroxidase/sangue , Glutationa Peroxidase/urina , Glutationa Redutase/sangue , Glutationa Redutase/urina , Humanos , Selênio/sangue , Selênio/urina
10.
Biol Trace Elem Res ; 83(2): 103-10, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11762527

RESUMO

Iron overload could promote the generation of free radicals and result in deleterious cellular damages. A physiological increase of oxidative stress has been observed in pregnancy. A routine iron supplement, especially a combined iron and vitamin C supplementation, without biological justifications (low hemoglobin [Hb] and iron stores) could therefore aggravate this oxidative risk. We investigated the effect of a daily combined iron supplementation (100 mg/d as fumarate) and vitamin C (500 mg/d as ascorbate) for the third trimester of pregnancy on lipid peroxidation (plasma TBARS), antioxidant micronutriments (Zn, Se, retinol, vitamin E, (beta-carotene) and antioxidant metalloenzymes (RBC Cu-Zn SOD and Se-GPX). The iron-supplemented group (n = 27) was compared to a control group (n = 27), age and number of pregnancies matched. At delivery, all the women exhibited normal Hb and ferritin values. In the supplemented group, plasma iron level was higher than in the control group (26.90 +/- 5.52 mmol/L) and TBARs plasma levels were significantly enhanced (p < 0.05) (3.62 +/- 0.36 vs 3.01 +/- 0.37 mmol/L). No significant changes were observed in plasma trace elements and red blood cell antioxidant metalloenzymes. Furthermore, the alpha-tocopherol plasma level was lowered in the iron-supplemented groups, suggesting an increased utilization of vitamin E. These data show that pharmalogical doses of iron, associated with high vitamin C intakes, can result in uncontrolled lipid peroxidation. This is predictive of adverse effects for the mother and the fetus. This study illustrates the potential harmful effects of iron supplementation when prescribed only on the assumption of anemia and not on the bases of biological criteria.


Assuntos
Ácido Ascórbico/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Ferro/efeitos adversos , Peroxidação de Lipídeos/efeitos dos fármacos , Gravidez/metabolismo , Adulto , Antioxidantes/metabolismo , Índice de Apgar , Eritrócitos/metabolismo , Feminino , Ferritinas/sangue , Hemoglobinas/análise , Humanos , Recém-Nascido , Ferro/sangue
11.
Eur J Neurosci ; 11(9): 3199-214, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10510184

RESUMO

Sonic hedgehog (Shh), a morphogen molecule implicated in embryonic tissue patterning, displays inductive, proliferative, neurotrophic and neuroprotective activities on various neural cells. Shh might exert its biological functions through binding to patched (Ptc) associated with smoothened (Smo), leading to downstream activation of target genes such as the transcription factor Gli1. We have performed a detailed localization of cells expressing transcripts of Shh, Ptc, Smo and Gli1 in brain and spinal cord of the adult rat as well as in the developing cerebellum. In the adult, Shh-positive cells were mainly observed in forebrain structures, in the Purkinje cells of the cerebellum and in motor neurons. Ptc-positive cells were frequently observed in brain areas devoid of any Shh transcripts, except in the median eminence or the facial nucleus, suggesting local Shh signalling. Interestingly, Smo transcripts were predominantly present within circumventricular organs, in granular cells of the dentate gyrus and in neurons of the reticular thalamic nucleus. The presence of Shh, Ptc and Smo transcripts in hypothalamic areas may indicate a role of Shh signalling in the modulation of neuroendocrine functions. The expression pattern of these three genes as well as of Gli1, and their developmental regulation in the cerebellum, suggest a possible role for Hedgehog signalling in the control of various cell populations within the cerebellum, particularly in granule cell proliferation and/or differentiation that might be impaired in proliferative states such as medulloblastomas.


Assuntos
Sistema Nervoso Central/crescimento & desenvolvimento , Sistema Nervoso Central/fisiologia , Transdução de Sinais/fisiologia , Transativadores , Animais , Northern Blotting , Química Encefálica/fisiologia , Mapeamento Encefálico , Neoplasias Encefálicas/fisiopatologia , Digoxigenina , Fator IX/biossíntese , Fator IX/genética , Regulação da Expressão Gênica/fisiologia , Proteínas Hedgehog , Hibridização In Situ , Masculino , Biossíntese de Proteínas , Proteínas/genética , RNA/biossíntese , RNA/isolamento & purificação , Sondas RNA , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Medula Espinal/metabolismo
12.
Food Chem Toxicol ; 37(9-10): 925-30, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10541446

RESUMO

The "SUpplementation en VItamines et Minéraux AntioXydants" (SU.VI.MAX) Study is a randomized double-blind, placebo-controlled, primary-prevention trial which started in 1994 in France. This epidemiologic study is designed to test the efficacy of a daily supplementation with antioxidant vitamins (vitamin C, 120 mg, vitamin E, 30 mg, and beta-carotene, 6 mg) and minerals (selenium, 100 microg, and zinc, 20 mg) at nutritional doses, in reducing the main causes of premature death (cancers and cardiovascular diseases); 12,735 eligible subjects (women aged 35 to 60 years, and men aged 45 to 60 years) were included in 1994 and and will be followed up for 8 years. Participants undergo a yearly visit consisting, every other year, of either biological sampling or clinical examination. They also regularly provide information on health events and dietary intake by filling out computerized questionnaires using the Minitel Telematic Network. After 2 years of supplementation, biochemical indicators of vitamin and trace element status reach reasonable level without reaching concentrations as high as those observed in intervention studies, which tested relatively high doses of antioxidants, and ended up with higher risk of pathology.


Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Doença das Coronárias/prevenção & controle , Suplementos Nutricionais , Minerais/farmacologia , Neoplasias/prevenção & controle , Vitamina E/farmacologia , beta Caroteno/farmacologia , Adulto , Antioxidantes/administração & dosagem , Ácido Ascórbico/sangue , Doença das Coronárias/epidemiologia , Método Duplo-Cego , Feminino , França , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Minerais/administração & dosagem , Neoplasias/epidemiologia , Estado Nutricional , Selênio/farmacologia , Inquéritos e Questionários , Fatores de Tempo , Vitamina E/sangue , Zinco/farmacologia , beta Caroteno/sangue
13.
J Chromatogr B Biomed Sci Appl ; 729(1-2): 333-9, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10410959

RESUMO

The detection and quantitation of slight increases of plasma homocysteine levels is of growing interest. This has prompted us to develop a highly sensitive and accurate capillary gas chromatography-mass spectrometry (GC-MS) method. The method proved to be highly sensitive (DL=0.17 micromol/l) with between- and within-run precision less than 6% and 7%, respectively. Reference values of plasma total homocysteine have been determined for men (n=39) and women (n=36), showing a significant difference (P=0.003) between gender. Preliminary results in cerebrovascular accidents and in venous thrombosis are presented.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Homocisteína/sangue , Adulto , Calibragem , Estudos de Casos e Controles , Transtornos Cerebrovasculares/sangue , Feminino , Humanos , Isótopos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Trombose Venosa/sangue
14.
Ann Biol Clin (Paris) ; 57(3): 273-82, 1999 May.
Artigo em Francês | MEDLINE | ID: mdl-10377477

RESUMO

Inverse correlations have been found in most studies on the relationship between dietary intake and plasma concentrations of carotenoids on one side and degenerative diseases such as cancer and cardiovascular diseases on the other side. Protective effects of carotenoids have been found for pathologies of the retina and the skin. Concentrations of these molecules in blood are lower in digestive pathologies and HIV. Short- and long-term toxicity of carotenoids was found to be low. In combination with the beneficial effects found for diets rich in carotenoids, this has initiated trials with relatively high doses of carotenoid supplements. In the study in Linxian (China) in a rural population with poor nutritional status, supplementation with beta-carotene, zinc, selenium and vitamin E lowered total mortality and mortality from stomach cancer. Other studies (ATBC, Caret.) on well-fed subjects did not show beneficial effects on mortality from cancer and cardiovascular diseases. On the contrary, higher mortality and lung cancer incidence was found in supplemented subjects that were also exposed to asbestos and cigarette smoke. In these studies, doses of supplemental beta-carotene were high and varied from 20 to 50 mg/day. One still ongoing study, called Suvimax, doses subjects for eight years with a cocktail of vitamins and minerals including 6 mg per day of beta-carotene. This supplementation with physiologically seen more "normal" doses might give clarity on the question if beta-carotene is the protective factor in fruits and vegetables.


Assuntos
Anticarcinógenos , Doenças Cardiovasculares/prevenção & controle , Carotenoides , Suplementos Nutricionais , Neoplasias/prevenção & controle , Vitamina E , Carotenoides/sangue , Carotenoides/uso terapêutico , China/epidemiologia , Humanos , Neoplasias/epidemiologia , Neoplasias/mortalidade , Doenças Retinianas/prevenção & controle , Dermatopatias/prevenção & controle , Vitamina E/sangue , Vitamina E/uso terapêutico
15.
Ann Biol Clin (Paris) ; 57(2): 169-83, 1999.
Artigo em Francês | MEDLINE | ID: mdl-10210743

RESUMO

Carotenoids are a family of pigments with at least 600 members. They derive from lycopene after steps of cyclisation, dehydrogenation and oxidation. It is their chemical structure that determines their physiochemical properties and, in part, their biological activities. About 50 carotenoids can be found in human diet and about 20 of them have been found in plasma and tissues. There is no RDA (Recommended Daily Allowance) for carotenoids. Quantities of carotenoids in diet are difficult to estimate, partly because methods used for the establishment of food composition tables were not specific and sensitive enough. Also, given values do not always take into account variations due to season and region of culture. Absorption of beta-carotene in humans has been the subject of numerous studies but only very little is known about other carotenoids. In general, absorption depends on bioavailability from the food matrix and solubility in micelles. After absorption through passive diffusion, carotenoids follow the chylomicrons metabolism. They are taken up by the liver and released in the blood stream in lipoproteins (VLDL). Carotenoids with no-substituted beta-ionone cycles (alpha and beta-carotene and beta-cryptoxanthin) have provitamin A activity. Highest activity has been found for all-trans beta-carotene. Not all steps of vitamin A biosynthesis and metabolism of other carotenoids have been clarified yet. Besides their provitamin A activity, carotenoids have numerous biological functions. They are efficient scavengers of free radicals, particularly of 1O2. In vitro they have been shown to protect LDL. However, results in vivo are inconsistent. Other functions include enhancement of gap junctions, immunomodulation and regulation of enzyme activity involved in carcinogenesis.


Assuntos
Carotenoides/metabolismo , Absorção , Adjuvantes Imunológicos/farmacologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Disponibilidade Biológica , Carcinógenos/metabolismo , Carotenoides/análise , Carotenoides/sangue , Carotenoides/química , Carotenoides/fisiologia , Criptoxantinas , Dieta , Difusão , Análise de Alimentos , Sequestradores de Radicais Livres/farmacologia , Junções Comunicantes/fisiologia , Humanos , Lipoproteínas VLDL/sangue , Fígado/metabolismo , Licopeno , Política Nutricional , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Distribuição Tecidual , Vitamina A/fisiologia , Xantofilas , beta Caroteno/análogos & derivados , beta Caroteno/fisiologia
16.
Free Radic Res ; 30(3): 173-80, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10711787

RESUMO

Cigarette smoke is known to generate free radicals by various mechanisms. In this study involving 30 non-smokers and 30 smokers, we show that urinary excretion of 5-(hydroxymethyl) uracil (HMUra) was not different in the two groups (6.54+/-2.07 vs. 6.70+/-1.68 nmol/mmol creatinine). In contrast, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) excretion increased by 16% (1.16+/-0.35 vs. 1.35+/-0.50 nmol/mmol creatinine, p = 0.039). Results concerning 8-oxo-dGuo are in agreement with those of previous studies. We observed significant multiple correlations between HMUra and creatinine (r(p) = 0.44), BMI (r(p) = -0.27) and nicotine derivatives (r(p) = 0.26). Multiple correlation analysis showed relations between 8-oxo-dGuo on the one hand, and: creatinine (r(p) = 0.36), nicotine derivatives (r(p) = 0.29), BMI (r(p) = -0.24) on the other.


Assuntos
Desoxiguanosina/análogos & derivados , Pentoxil (Uracila)/análogos & derivados , Fumar/urina , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Estudos de Casos e Controles , Dano ao DNA , Desoxiguanosina/urina , Radicais Livres/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Oxirredução , Pentoxil (Uracila)/urina , Fumar/metabolismo
17.
Free Radic Res ; 28(4): 377-82, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9684982

RESUMO

We measured the base 5-(hydroxymethyl) uracil (HMUra) and the nucleoside 8-oxo-7,8-dehydro-2'-deoxyguanosine (8-oxo-dGuo) in urine of adriamycin-treated cancer patients. Adriamycin has been shown to generate oxygen free radicals by various mechanisms. HMUra and 8-oxo-dGuo are two known lesions of DNA, produced by oxygen free reaction on thymine and 2'-deoxyguanosine, respectively. HMUra was measured by GC-MS/isotopic dilution and 8-oxo-dGuo by HPLC/EC, both after prepurification by semipreparative HPLC. Here we report the results of a study involving 20 cancer patients treated with flash doses of ADR. We found that urine HMUra is significantly increased (HMUra (nmol/24h): 80.8 8.44 vs. 98.7+/-6.87; p < 0.01) 24h after administration of the drug, while 8-oxo-dGuo did not show any significant variation. Urine HMUra seems to be a suitable short-term marker of DNA alterations by oxygen free radicals.


Assuntos
DNA/metabolismo , Desoxiguanosina/análogos & derivados , Doxorrubicina/uso terapêutico , Neoplasias/urina , Pentoxil (Uracila)/análogos & derivados , 8-Hidroxi-2'-Desoxiguanosina , Antibióticos Antineoplásicos/uso terapêutico , Desoxiguanosina/metabolismo , Desoxiguanosina/urina , Feminino , Humanos , Masculino , Neoplasias/tratamento farmacológico , Oxirredução , Pentoxil (Uracila)/metabolismo , Pentoxil (Uracila)/urina , Substâncias Reativas com Ácido Tiobarbitúrico/análise
18.
Int J Cancer ; 77(1): 40-6, 1998 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-9639392

RESUMO

The urinary excretion of 5-(hydroxymethyl)uracil (5-HMUra), one of the major oxidative modifications of thymine, was investigated in 134 healthy volunteers living in North Italy. Overnight urine was collected, and a questionnaire was completed on smoking habits and exposure to environmental tobacco smoke (ETS). 5-HMUra was analyzed by GC/MS, following urine purification by HPLC. 5-HMUra excretion showed an approximately normal distribution, ranging from 0.08 to 0.84 (mean 0.44) nmoles/kg/8 hr and from 3.2 to 18.7 (mean 8.5) nmoles/mmoles creatinine. 5-HMUra excretion was significantly higher in women than in men and in smokers than in non-smokers when results were expressed as the ratio to creatinine. Slightly higher levels of 5-HMUra excretion, expressed as nmoles/mmoles creatinine, were also found in subjects highly exposed to ETS, monitored either as the number of hours of exposure or as the number of smokers in the workplace and at home. Our results show that the urinary excretion of 5-HMUra is higher than that of other oxidized nucleobases, including 8-oxo-7,8-dihydroguanine, and can be slightly modified by environmental factors such as tobacco smoke. These findings suggest that measurement of urinary excretion of 5-HMUra could be useful as a biomarker of oxidative DNA damage and repair, though further research is needed to support these data.


Assuntos
Fumar , Uracila/urina , Adulto , Dano ao DNA , Reparo do DNA , Feminino , Humanos , Masculino , Oxirredução
19.
Eur J Gastroenterol Hepatol ; 10(12): 1021-4, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9895048

RESUMO

OBJECTIVE: A concise, detailed, and complete instruction sheet is indispensable for adequate completion by the users of a product. This sheet should be enclosed in the envelope which contains Hemoccult II slides. The authors found that the instructions provided by the French manufacturer were unsatisfactory. They designed a short and simple notice, adequately detailed to be understandable by all volunteers and to obtain satisfactory stool smears. Positivity rates of Hemoccult II performed with the manufacturer's notice were compared to those obtained with Hemoccult II performed with the authors' instructions. METHODS: This study was made during the third screening campaign carried out by the Office Departemental de Lutte contre le Cancer (ODLC). This screening programme only concerned women 59 to 69 years of age. Six thousand three hundred and ninety-two Hemoccult II containing the manufacturer's instructions were received at the laboratory during March, April, May, June and July 1996, and 2633 Hemoccult II containing the ODLC instructions during March, April, May, June and July 1997. All Hemoccult II were developed and read by one trained technician in the Biochemistry Laboratory (Grenoble University Hospital). RESULTS: The two populations, studied in 1996 and 1997, were strictly comparable in terms of age and number of previous screenings. Out of 6392 Hemoccult II containing the manufacturer's instructions, 157 (2.5%) were found positive, as compared to 36 (1.4%) Hemoccult II out of 2633 which contained the authors' instructions. This difference is highly significant (P = 0.001). CONCLUSION: The directions for use provided with Hemoccult II had a crucial influence on positivity rates, and therefore on the cost of screening. The instruction sheet provided by the French manufacturer is not satisfactory as it contains too much needless information, while several important pieces of advice are missing.


Assuntos
Neoplasias Colorretais/diagnóstico , Comunicação , Sangue Oculto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade
20.
Bull Cancer ; 83(8): 641-8, 1996 Aug.
Artigo em Francês | MEDLINE | ID: mdl-8869044

RESUMO

The mass screening program for cancer in the Isere department offers women between 50 and 69 years a medical consultation and three tests: mammography for breast cancer screening, Pap smear for cervical cancer screening, and hemoccult for colorectal cancer. During the first round, 29,570 women took part in the program, 21% had a mammography, 20% Pap smears and 25% a hemoccult. In breast cancer screening, the rate for further examination was 11.9%, the breast cancer detection rate was 5.4 per 1,000 women screened and the detection rate of invasive tumor < or = 10 mm: 2.0 per 1,000. In cervical cancer screening, the rate of abnormal examinations was 1.2%. The cervical cancer detection rate was 1.5 per 1,000. The rate of positive hemoccult was 2.7% and the rate of colorectal cancers and polyps 10 mm or larger was 2.7 per 1000. Results of screening are satisfying, but compliance rate is too low. Acceptance rate must be examined in following rounds.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias do Colo/epidemiologia , Neoplasias Retais/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Idoso , Neoplasias da Mama/prevenção & controle , Neoplasias do Colo/prevenção & controle , Feminino , França/epidemiologia , Humanos , Incidência , Mamografia , Programas de Rastreamento , Pessoa de Meia-Idade , Sangue Oculto , Teste de Papanicolaou , Neoplasias Retais/prevenção & controle , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal
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