Gene, Genome, Toxicogenomics
The NIEHS and its scientific partners are helping to articulate the interrelationship between the human genome and the environment. Three articles in this month's NIEHS News (p. 20) describe innovative projects in genetics research that are part of this effort.
Brave New World
In this century scientists have embarked on a genetic treasure hunt, seeking to map the human genome. The Focus (p. 24) gives an overview of the past, present, and future of this quest to understand the basic building blocks of life.
Genes for Sale?
Close on the heels of the discovery of gene sequences comes the question of who "owns" the genetic information. The Spheres of Influence (p. 30) examines the question of whether and in what cases genetic information should be patentable.
Prints of 'Tides
This month's Innovations (p. 34) describes a new system that uses inkjet printer technology to produce custom-designed microarrays of nucleotides with greater precision, less cost, and a faster turnaround than ever before possible.
Challenges of Environmental Epidemiology
The Commentary by Pekkanen and Pearce (p. 1) emphasizes that research on environmental epidemiology must be conducted at the population and ecosystem levels, in addition to the molecular level, and that progress must be complementary rather than competitive between the different levels of analysis.
Non-Cancer Risk Assessment in Russia
Privalova et al. (p. 7) selected an industrialized town for multimedia-multipollutant risk assessment. Assessment of noncarcinogenic risks due to total suspended particles, sulfur dioxide, nitrogen dioxide, lead, and cadmium are discussed as an example of how quantitative estimates of health effects can be produced by using a risk function approach.
Nasal Sensitivity to Airborne Irritants
Shusterman et al. (p. 15) examined nasal irritant sensitivity in individuals exposed to carbon dioxide (detection) and to n-propanol (localization). Females exhibited a lower threshold of response to exposure than males. The authors suggest that there is variability between subjects in nasal trigeminal sensitivity (perceptual acuity) and that this may cross classes of chemical agents and be nonrandom in the population.
Estuary-Associated Syndrome in North Carolina
Exposure of watermen to fish kills and fish with lesions attributed to Pfiesteria were examined to determine if there were toxic effects. After examination for medical, neurologic, neuropsychologic, or neurobehavioral effects, Swinker et al. (p. 21) did not identify an increased risk of estuary-associated syndrome in exposed watermen, except for a decrease in visual contrast sensitivity, and suggested that this marker be included in future studies. (Also see Science Selections, p. A39)
Autoimmunity Model in Lupus-Prone Mice
Pollard et al. (p. 27) found that mercury exposure of autoimmune-prone BXSB mice accelerated systemic autoimmunity in both sexes, but did not affect nonautoimmune C57BL/6 mice, suggesting that even low concentrations of chemicals could affect genetically susceptible hosts.
Chronic Chloroform Toxicity to Fish
Japanese medaka fish were exposed for 9 months to graded concentrations of chloroform in a flow-through system by Toussaint et al. (p. 35). Liver toxicity at 6 and 9 months was confirmed by gall bladder lesions and bile duct abnormalities, but no liver neoplasms were observed.
Cancer Risk and Chromosome Aberrations
Smerhovsky et al. (p. 41) conducted cytogenetic analysis in 3,973 subjects in the Czech Republic and report a moderate risk of cancer in individuals with an elevated frequency of chromosomal aberrations. In miners exposed to radon gas, there was a 64% increase in the risk of cancer for a 1% increase in the frequency of chromosomal aberrations.
Spread of Bacillus in Gypsy Moth Spray
Airborne exposures to the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) were measured by Teschke et al. (p. 47) during an aerial spray program to eradicate gypsy moths in Canada. The authors found that indoor insecticide concentrations exceeded outdoor concentrations 5-6 hr after spraying, that the disappearance of insecticide exhibited a half-time of 2.4 days, and that drift outside the spray zone was related more to wind velocity and direction than to distance from the spray zone.
Bisphenol A in the Mouse Uterotrophic Assay
Markey et al. (p. 55) examined the estrogenicity of bisphenol A in the immature CD-1 mouse. The authors demonstrated that uterine cell morphology, induction of lactoferrin, and expression of proliferating cell nuclear antigen are more sensitive to bisphenol A than uterine wet weight, and that these end points are more suitable for determining the estrogenicity of synthetic chemicals.
Fish Model for Metabolism
Epoxide hydrolases, which are inhibited by pesticides containing urea, carbamate, and amide moieties, were used as a biomarker for contaminant screening in fathead minnow and golden medaka larvae by Newman et al. (p. 61). Although the biomarker was effective, there was no correlation between enzyme inhibition and developmental toxicity; thus, there is little apparent risk from the tested pesticides interacting with this biochemical target.
Genetic Markers in Chinook Salmon
Nagler et al. (p. 67) examined the incidence of phenotypic sex reversal in salmon that returned to spawn and report a high incidence of a genetic marker for the Y chromosome in phenotypic females. The authors found that female salmon with a male genotype were sex reversed, suggesting that this could create the potential for a YY genotype in salmon to produce all male offspring and alter sex ratios in the endangered species.
Gene Arrays in Toxicology
Bartosiewicz et al. (p. 71) used DNA arrays containing 148 genes to examine gene expression patterns in the liver of mice in response to cadmium, benzo(a)pyrene, and trichloroethylene. The authors show that microarray analysis with a focused set of genes is capable of differentiating toxic levels and suggest that such studies must employ multiple doses and time points for effective toxicity assessment. (Also see Science Selections, p. A38)
Lessons from Breast Milk Monitoring
A review of breast milk monitoring programs in the United States by LaKind et al. (p. 75) indicates there are incomplete data on parameters related to infant exposure by breast-feeding, especially data with a time-dependent nature. Although the authors stress that breast-feeding is the preferred nutrition, data are needed for the levels of chemicals in human milk and for the rate of elimination of chemicals from the nursing mother to develop sound information on benefits and risks of breast-feeding. (Also see Science Selections, p. A38)
GIS Used to Prevent Child Lead Poisoning
Reissman et al. (p. 89) used a geographic information system to assist in identifying children at risk for lead poisoning in Kentucky. Homes where more than one child had been poisoned by lead between 1994 and 1998 were prioritized for lead hazard remediation, but the authors found that significant numbers of at-risk children had not been tested for lead exposure, even in prioritized areas.
Hypertension and Chronic Lead Toxicity
Hu (p. 95) presents the case of poorly controlled hypertension in a house painter with chronic lead toxicity. The patient's lead-induced hypertension seemed to respond positively to a high-calcium diet. The author recommends that homeowners and workers should be educated about the hazards of existing lead-based paint and that individuals working with this paint should be carefully monitored.
Last Updated: January 9, 2001
