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1.
Cancer Epidemiol Biomarkers Prev ; 16(6): 1213-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17548687

RESUMO

Liver cancer is the leading cause of cancer death in many regions of the world. With the goal to discover biomarkers that reflect subsets of high-risk individuals and their prognosis, we nested our study in a male cohort of 5,581 hepatitis B surface antigen carriers in Qidong, People's Republic of China, who were recruited starting in 1989. By December 2003, 667 liver cancer cases were diagnosed in this group and plasma samples collected at the initial screening at enrollment were available in 515 cases who had succumbed to liver cancer. Hepatitis B virus (HBV) DNA could be isolated in 355 (69%) of these samples. In 14%, 15%, 19%, 31%, and 22%, screening took place at < or = 1.5, 1.51 to 3, 3.01 to 5, 5.01 to 9, and > 9 years before death, respectively; and 39% died at age below 45 years. The relation between mutations in HBV and time to death were determined by logistic regression for the odds of mutation and by survival analyses methods with age as the time scale. In 279 (79%) of these individuals, the samples contained a two-nucleotide 1762T/1764A HBV mutation. Sixteen samples lacking the 1762T/1764A mutation had novel mutations elsewhere in the 1761 to 1767 region of the HBV genome. There was a statistically significant difference (P = 0.012) for the high prevalence of the HBV mutations in the men who died from hepatocellular carcinoma under the age of 45 years relative to those who died after 55 years of age and HBV mutations accelerated death (relative hazard, 1.40; 95% confidence interval, 1.06-1.85) and that the effect was attenuated by age from 2.04 for age 35 years to 1.0 for age 65 years with the 90% confidence band being above 1 for ages < 50 years. These findings provide a conceptual framework to explain the acceleration of mortality in individuals infected with HBV.


Assuntos
Carcinoma Hepatocelular/virologia , DNA Viral/sangue , Vírus da Hepatite B/genética , Hepatite B/genética , Neoplasias Hepáticas/virologia , Infecções Tumorais por Vírus/genética , Adulto , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Estudos de Coortes , Análise Mutacional de DNA , DNA Viral/genética , Hepatite B/sangue , Hepatite B/complicações , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase , Infecções Tumorais por Vírus/sangue , Infecções Tumorais por Vírus/complicações
2.
Cancer Epidemiol Biomarkers Prev ; 14(11 Pt 1): 2605-13, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16284385

RESUMO

Residents of Qidong, People's Republic of China, are at high risk for development of hepatocellular carcinoma, in part due to consumption of aflatoxin-contaminated foods, and are exposed to high levels of phenanthrene, a sentinel of hydrocarbon air toxics. Cruciferous vegetables, such as broccoli, contain anticarcinogens. Glucoraphanin, the principal glucosinolate in broccoli sprouts, can be hydrolyzed by gut microflora to sulforaphane, a potent inducer of carcinogen detoxication enzymes. In a randomized, placebo-controlled chemoprevention trial, we tested whether drinking hot water infusions of 3-day-old broccoli sprouts, containing defined concentrations of glucosinolates, could alter the disposition of aflatoxin and phenanthrene. Two hundred healthy adults drank infusions containing either 400 or < 3 micromol glucoraphanin nightly for 2 weeks. Adherence to the study protocol was outstanding; no problems with safety or tolerance were noted. Urinary levels of aflatoxin-N(7)-guanine were not different between the two intervention arms (P = 0.68). However, measurement of urinary levels of dithiocarbamates (sulforaphane metabolites) indicated striking interindividual differences in bioavailability. An inverse association was observed for excretion of dithiocarbamates and aflatoxin-DNA adducts (P = 0.002; R = 0.31) in individuals receiving broccoli sprout glucosinolates. Moreover, trans, anti-phenanthrene tetraol, a metabolite of the combustion product phenanthrene, was detected in urine of all participants and showed a robust inverse association with dithiocarbamate levels (P = 0.0001; R = 0.39), although again no overall difference between intervention arms was observed (P = 0.29). Understanding factors influencing glucosinolate hydrolysis and bioavailability will be required for optimal use of broccoli sprouts in human interventions.


Assuntos
Aflatoxinas/urina , Anticarcinógenos/farmacologia , Brassica/química , Adutos de DNA/urina , Glucosinolatos/farmacologia , Fenantrenos/urina , Adulto , Aflatoxinas/metabolismo , Idoso , Bebidas , Disponibilidade Biológica , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/prevenção & controle , Feminino , Humanos , Hidrólise , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/prevenção & controle , Masculino , Pessoa de Meia-Idade , Placebos
3.
Gastroenterology ; 127(5 Suppl 1): S310-8, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15508099

RESUMO

Hepatocellular carcinoma is one of the most common cancers worldwide. Infection with hepatitis B virus and exposure to aflatoxins in the diet act synergistically to amplify risk. From a public health perspective, hepatitis virus vaccination programs and efforts to both reduce aflatoxin exposures and to attenuate the toxicological consequences of unavoidable exposures should have major impacts on the global incidence of this disease. Experimentally, aflatoxin-induced hepatocarcinogenesis can be inhibited by over a score of different chemopreventive agents with multiple mechanisms of action. One agent, oltipraz, is a potent inducer of phase 2 enzymes involved in the detoxication of carcinogens including aflatoxin. A second agent, chlorophyllin, impedes the bioavailability of carcinogens by forming molecular complexes and enhances their elimination in the fecal stream. This review highlights the findings of recent randomized clinical trials with oltipraz and chlorophyllin conducted in individuals exposed to dietary aflatoxins and at high risk for development of liver cancer. Both chemopreventive agents modulated levels of aflatoxin biomarkers in the study participants in manners consonant with protection. Although pharmacological approaches establish proof of principle and help identify key molecular targets for interventions, food-based approaches that also use these molecular targets may be the most practical for widespread application in high-risk populations.


Assuntos
Aflatoxinas/efeitos adversos , Anticarcinógenos/uso terapêutico , Antimutagênicos/uso terapêutico , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/prevenção & controle , Contaminação de Alimentos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/prevenção & controle , Quimioprevenção , Dieta , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
4.
Zhonghua Gan Zang Bing Za Zhi ; 11(6): 347-9, 2003 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-12837213

RESUMO

OBJECTIVE: To explore whether there exists coincidence of the most appearing time of clinical features of liver cancer at different longitude and latitude, according to the law of field equation and the theory of warpage of space time by Einstein. METHODS: Three regions with different longitude and latitude were selected randomly and sampled. There were 36 items altogether, including 12 clinical items, which were used to imitate the yearly cycle cosine curve. The acorphases and the ratioes of amplitudes and means were compared to justifying whether they were in the same range. RESULTS: All the acorphases of 36 items appeared between -90.1degrees to -207.5 degrees (from april to july), existing in one third of the same range, in which 13 items occurred rhythmly (P<0.05). The image acorphases of liver cancer at the early and middle stage and gamma-glutamyl transpeptidase acorphase appeared between -98.5 degrees to -148.2 degrees (from april to may), in which 5 items occurred rhythmly (P<0.05). CONCLUSION: It is the same mode of the yearly biologcal cycle for liver cancer malignant growth within the most appearing time (from april to july). It will increase the detecting rate of liver cancer at the early and middle stage during this time (especially from april to may).


Assuntos
Carcinoma Hepatocelular/patologia , Ciclo Celular/fisiologia , Fenômenos Cronobiológicos , Neoplasias Hepáticas/patologia , Periodicidade , Hepatócitos/fisiologia , Humanos , Computação Matemática
5.
Eur J Cancer Prev ; 11 Suppl 2: S58-64, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12570336

RESUMO

Liver cancer is one of the most common cancers worldwide. Infection with hepatitis B virus and exposure to aflatoxins in the diet act synergistically to amplify risk. From a public health perspective, hepatitis virus vaccination programs and efforts to both reduce aflatoxin exposures and to attenuate the toxicological consequences of unavoidable exposures should have major impacts on the incidence of this disease. Experimentally, aflatoxin-induced hepatocarcinogenesis can be inhibited by over a score of different chemopreventive agents with multiple mechanisms of action. One agent, oltipraz, is a potent inducer of phase 2 enzymes involved in the detoxication of carcinogens including aflatoxin. A second agent, chlorophyllin, impedes the bioavailability of carcinogens by forming molecular complexes and enhances their elimination in the fecal stream. This review highlights the findings of recent randomized clinical trials with oltipraz and chlorophyllin conducted in individuals exposed to dietary aflatoxins and at high risk for development of liver cancer. Both chemopreventive agents modulated levels of aflatoxin biomarkers in the study participants in manners consonant with protection.


Assuntos
Anticarcinógenos/administração & dosagem , Carcinoma Hepatocelular/prevenção & controle , Quimioprevenção/métodos , Clorofilídeos/administração & dosagem , Neoplasias Hepáticas/prevenção & controle , Pirazinas/administração & dosagem , Ensaios Clínicos como Assunto , Feminino , Previsões , Humanos , Masculino , Prevenção Primária/normas , Prevenção Primária/tendências , Prognóstico , Medição de Risco , Tionas , Tiofenos
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