Abstract:
:Some of the statistical properties of a simple two-stage model of carcinogenesis are explored. The implications of additive treatment effects versus independent treatment effects on the shape of the dose-response curve are considered. Response that is low-dose linear results in the cases where the mutation rates are affected by dose or in the cases where treatment changes the birth rate/death rate of initiated cells in an additive fashion. Independent treatment effects lead to non-low-dose linear response when the survival of initiated cells is affected by treatment. A computer simulation experiment was performed that examined the ability of animal carcinogenesis data to differentiate between various forms of this simple two-stage model. It is shown that animal carcinogenicity experiments do not contain enough data to adequately describe the difference between these two types of effects.
journal_name
Environ Health Perspectjournal_title
Environmental health perspectivesauthors
Portier CJdoi
10.1289/ehp.8776125subject
Has Abstractpub_date
1987-12-01 00:00:00pages
125-31eissn
0091-6765issn
1552-9924journal_volume
76pub_type
杂志文章abstract::Forty percent of hazardous waste sites in the United States are co-contaminated with organic and metal pollutants. Data from both aerobic and anaerobic systems demonstrate that biodegradation of the organic component can be reduced by metal toxicity. Metal bioavailability, determined primarily by medium composition/so...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.5840
更新日期:2003-06-01 00:00:00
abstract::Many epidemiologic reports associate ambient levels of particulate matter (PM) with human mortality and morbidity, particularly in people with preexisting cardiopulmonary disease (e.g., chronic obstructive pulmonary disease, infection, asthma). Because much ambient PM is derived from combustion sources, we tested the ...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.97105s51053
更新日期:1997-09-01 00:00:00
abstract:BACKGROUND:Experimental tools for studying the complex steroidogenic interactions that occur between placenta and fetus during human pregnancy are extremely limited. OBJECTIVES:We aimed to develop a co-culture model to study steroidogenesis by the human fetoplacental unit and its disruption by exposure to environmenta...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.1307518
更新日期:2014-04-01 00:00:00
abstract::We used an improved method for trapping carbon-centered radicals (.R) from the gas-phase to compare radical suites trapped from various tobacco smoke and model smoke systems. Using a nitroxide trap, 3-amino-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (3AP), on solid support, we trapped radicals directly from the gas phase, ...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.01109765
更新日期:2001-08-01 00:00:00
abstract::An important public health challenge has been the need to protect children's health. To accomplish this goal, the scientific community needs scientifically based child-specific risk assessment methods. Critical to their development is the need to understand mechanisms underlying children's sensitivity to environmental...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.00108s113
更新日期:2000-03-01 00:00:00
abstract::The subchronic inhalation toxicology of ethylene glycol monoethyl ether (EGEE) was evaluated in rats and rabbits using a 13-week exposure regimen. Groups of 20 rabbits (10 M, 10 F) and 30 rats (15 M, 15 F) were exposed to a vapor of 25 ppm, 100 ppm, or 400 ppm, 6 hr/day, 5 days/week. The control groups received air on...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.8457157
更新日期:1984-08-01 00:00:00
abstract::Methylation is considered the detoxification pathway for inorganic arsenic (InAs), an established human carcinogen. Urinary speciation analysis is used to assess the distribution of metabolites [monomethylarsonate (MMA), dimethylarsinate (DMA), and unmethylated arsenic (InAs)], as indicators of methylation capacity. W...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.96104620
更新日期:1996-06-01 00:00:00
abstract:BACKGROUND:Organophosphate developmental neurotoxicity involves multiple mechanisms converging on neural cell replication and differentiation. OBJECTIVES:We evaluated mechanisms contributing to the adverse effects of chlorpyrifos (CPF) on DNA synthesis, cell number and size, and cell signaling mediated by adenylyl cyc...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.10194
更新日期:2007-09-01 00:00:00
abstract:BACKGROUND:Most studies on endocrine-disrupting chemicals and breast cancer have focused on single compounds and have produced inconclusive findings. OBJECTIVES:We assessed the combined estrogenic effects of mixtures of xenoestrogens in serum and their relationship to breast cancer risk. METHODS:A total of 186 incide...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/EHP157
更新日期:2016-10-01 00:00:00
abstract:BACKGROUND:In male rodents, anogenital distance (AGD) provides a sensitive and continuous correlate of androgen exposure in the intrauterine environment and predicts later reproductive success. Some endocrine-disrupting chemicals can alter male reproductive tract development, including shortening AGD, in both rodents a...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.1103421
更新日期:2011-07-01 00:00:00
abstract::This study assessed whether exposure of male rats to two estrogenic, environmental chemicals, 4-octylphenol (OP) and butyl benzyl phthalate (BBP) during gestation or during the first 21 days of postnatal life, affected testicular size or spermatogenesis in adulthood (90-95 days of age). Chemicals were administered via...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.951031136
更新日期:1995-12-01 00:00:00
abstract:BACKGROUND:Functional limitations are a major cause for needing care and institutionalization among older adults. Exposure to air pollution has been suggested to be associated with increased functional limitations in older people. OBJECTIVE:Our objective was to assess the association between air pollution and physical...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/EHP2239
更新日期:2018-01-19 00:00:00
abstract::Most air pollution in West Germany is caused by combustion products. Particulate organic matter released by incomplete combustion is suspected to contribute to the "urban factor" of lung cancer frequency in urban-industrial centers. The carcinogenic potential of single components, groups of compounds and total source ...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.8347293
更新日期:1983-01-01 00:00:00
abstract:BACKGROUND:The upward trend in industrial nations in the incidence of male genitourinary (GU) conditions may be attributed to increased exposure to endocrine disruptors. Polybrominated biphenyl (PBB), a brominated flame retardant, is one such suspected endocrine disruptor. OBJECTIVE:We investigated the relationship be...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.0800058
更新日期:2009-07-01 00:00:00
abstract::The immune system comprises a highly integrated network of multiple tissues and cell types with complicated interactions and effects. It is modulated by the endocrine and nervous systems and there is growing realization of its multifunctionality. The session focusing on immunologic effects of dioxin and related compou...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.95103s2157
更新日期:1995-03-01 00:00:00
abstract:BACKGROUND:Studies suggest that phthalate exposures may adversely affect child respiratory health. OBJECTIVES:We evaluated associations between asthma diagnosed in children between 5 and 11 years of age and prenatal exposures to butylbenzyl phthalate (BBzP), di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEH...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.1307670
更新日期:2014-10-01 00:00:00
abstract::Southwest metropolitan Mexico City (SWMMC) inhabitants have been exposed several hours per day for the last 6 years to photochemical smog, ozone being the most important oxidant pollutant. Subjects exposed to the SWMMC atmosphere develop several histopathological changes in their nasal mucosa: dysplasia is the most si...
journal_title:Environmental health perspectives
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1289/ehp.101-1519752
更新日期:1993-06-01 00:00:00
abstract::Over 250 adults and children were exposed to chlordane when the wooden building surfaces and soil around an apartment complex were sprayed in 1987. Two hundred-sixteen adults had neurobehavioral functions measured and completed questionnaires for symptom frequency, mood status, confounding factors, and medical, rheuma...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.95103690
更新日期:1995-07-01 00:00:00
abstract::The best evidence of an adverse human health effect is a properly conducted epidemiological study. But human beings should not be the sole test animal. Properly conducted animal studies have been shown to be preductive for carcinogenicity and toxicologic responses in human populations. We need to develop more efficien...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.7932297
更新日期:1979-10-01 00:00:00
abstract::In vitro liver preparations are increasingly used for the study of hepatotoxicity of chemicals. In recent years their actual advantages and limitations have been better defined. The cell models, slices, and mainly primary hepatocyte cultures, appear to be the most powerful in vitro systems, as liver-specific functions...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.98106511
更新日期:1998-04-01 00:00:00
abstract::Inorganic particulate matter in foods and drugs is discussed from the standpoint of determination by optical microscopy, source, and regulatory significance. Some particulate matter may be generated as extraneous material and traced to specific operational practices during processing and production with excessive leve...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.749183
更新日期:1974-12-01 00:00:00
abstract::Research conducted in recent years has increased public health concern about the toxicity of lead at low dose and has supported a reappraisal of the levels of lead exposure that may be safely tolerated in the workplace. In this article, which appears as part of a mini-monograph on adult lead exposure, we summarize a b...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.9784
更新日期:2007-03-01 00:00:00
abstract::The normal mucociliary epithelium of the respiratory tract in chronic cigarette smokers often is replaced focally by a metaplastic squamous epithelium. Because asbestos workers who smoke have a substantially greater risk of bronchogenic carcinoma than nonsmokers, we hypothesized that interaction of asbestos with squam...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.835127
更新日期:1983-09-01 00:00:00
abstract::Exposure to indoor air pollutants such as tobacco smoke and dust mites may exacerbate childhood asthma. Environmental interventions to reduce exposures to these pollutants can help prevent exacerbations of the disease. Among the most important interventions is the elimination of environmental tobacco smoke from the en...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.95103s655
更新日期:1995-09-01 00:00:00
abstract::Historical aerial applications of the insecticide Matacil 1.8D provide an opportunity to look for potential effects of the endocrine disrupting compound 4-nonylphenol (4-NP) on Atlantic salmon (Salmo salar) populations. Matacil 1.8D contained the carbamate insecticide aminocarb, with 4-NP as primary solvent. Between 1...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.99107349
更新日期:1999-05-01 00:00:00
abstract:BACKGROUND:The potential impact of microwave radiofrequency electromagnetic fields (RF-EMF) emitted by wireless communication devices on neurocognitive functions of adolescents is controversial. In a previous analysis, we found changes in figural memory scores associated with a higher cumulative RF-EMF brain dose in ad...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/EHP2427
更新日期:2018-07-23 00:00:00
abstract::The toxic effects of cadmium and other heavy metals have been well established, and many of these and other environmental pollutants are known to be embryotoxic or teratogenic. However, it has proven difficult to identify individual cells that respond to toxicants among the wide range of cell populations in an intact ...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.021101041
更新日期:2002-10-01 00:00:00
abstract::Widespread and persistent organochlorine (OC) contaminants, such as polychlorinated biphenyls (PCBs) and pesticides, are known to have broad-ranging toxicities in wildlife. In this study we investigated, for the first time, their possible health effects on loggerhead sea turtles (Caretta caretta). Nonlethal fat biopsi...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.6923
更新日期:2004-07-01 00:00:00
abstract:BACKGROUND:Epidemiologic and experimental studies have reported a variety of health effects in response to ozone (O3) exposure, and some have indicated that certain populations may be at increased or decreased risk of O3-related health effects. OBJECTIVES:We sought to identify potential response-modifying factors to d...
journal_title:Environmental health perspectives
pub_type: 杂志文章,评审
doi:10.1289/ehp.1307541
更新日期:2014-11-01 00:00:00
abstract::In the fall of 1976 Congress enacted the Resource Conservation and Recovery Act, commonly referred to as RCRA. The objective of the statute is to create an orderly system for the generation, handling and disposal of hazardous waste by means of a comprehensive tracking and record keeping mechanism. RCRA does not regula...
journal_title:Environmental health perspectives
pub_type: 杂志文章
doi:10.1289/ehp.834819
更新日期:1983-02-01 00:00:00