Receptor Research
As part of the Under the Scope series, the NIEHS News (p. A502) looks at recent studies by the Ion Channel Physiology Group, led by Jerrel L. Yakel, which is particularly interested in identifying the molecular makeup and function of the nicotinic acetylcholine and serotonin receptors.
Environmental Links to Autoimmune Diseases
The Focus (p. A504) examines a new field of study--the potential role of environmental exposures in causing autoimmune diseases, the controversial and mysterious family of ailments in which the immune system attacks the body's own tissues.
Safety in Secrets?
The Spheres of Influence (p. A510) examines the world of audit-privilege laws, which allow companies to keep secret the findings of self-audits and depend on industry's voluntary disclosure of potential public health risks.
Corny Love Songs?
The Innovations (p. A514) describes the use of photoacoustics to scan corn kernels for fungus contamination. This technique uses infrared light to generate distinctive musical tones in corn kernels contaminated with deadly aflatoxin.
Research on Medicinal Herbs
Historically, medicinal herbs have been used for prevention and treatment of disease. In a Commentary, Matthews et al. (p. 773) warn of potential toxicity, interactions with other agents, and unknown adverse effects of herbal medicines. The authors also provide recommendations for research and educational materials.
Research on German Phytomedicine
The therapeutic efficacies and preventive natures of more than 400 phytopharmaceuticals have been studied in Germany. Wagner (p. 779) reports in a Commentary that although many herbal medicines are efficacious without adverse effects and sometimes act in an additive or synergistic manner to promote healing, more research on their mechanism(s) of action is needed.
History of Medicinal Plants from India
Approximately 1,250 plants are currently being used for holistic health care. Dev (p. 783) reviews the history of medicinal plants in India and describes studies that characterize the hypertensive alkaloid Rauwolfia serpentina and the gum-resin Commiphora wightti used for correcting lipid disorders, and provides examples of other holistic crude drugs prepared from the plant genera Asparagus, Cedrus, and Psoralea.
Senescence of Liver Peroxisomes
Youssef and Badr (p. 791) review metabolic activity of the liver in response to contaminant exposure in aging animals. The authors discuss studies on the impact of aging on basal liver peroxisomal metabolism, response to peroxisome proliferators, and changes in signal transduction pathways involved in these processes. Prevailing evidence indicates that there is both a decline and a muted response to chemical induction of liver enzyme activity accompanied by greater susceptibility to liver cancer in older as compared to younger animals.
Nitrogen Pollution Impacts Amphibian Survival
A review by Rouse et al. (p. 799) reports that concentrations of nitrate between 2.5 and 100 mg/L exert lethal and sublethal effects in amphibians. Nitrate concentrations in some North American watersheds reach toxic levels and may cause death and developmental anomalies in amphibians. The authors suggest the use of vegetated buffer strips adjacent to water courses to reduce nitrogen contamination and they urge reduction in point source nitrate contamination.
Using p53 Induction for Genotoxicity Tests
Duerksen-Hughes et al. (p. 805) used an alternative in vitro assay to test 25 chemicals previously analyzed by the NIEHS in the predictive toxicology project using in vivo carcinogenicity tests. The in vitro assay is based on the ability of cells to increase the level of their tumor suppressor p53 in response to DNA damage. The authors suggest that this test captures different information about biologic processes than the Ames test, the micronucleus assay, and the sister chromosome exchange.
Sex Ratio Changes in Finland
An analysis of sex ratios in the Finnish population from a 250-year period was conducted by Vartiainen et al. (p. 813). There was an increase in the proportion of males from 1751 to 1920, followed by a decrease and interrupted by peaks in births of males during and after World War I and World War II. The turning point of the male proportion precedes the period of industrialization or the introduction of hormonal drugs, suggesting that the decrease in the ratio of male-to-female births in industrial countries is not caused by environmental factors.
Predicting Arboviral Disease from El Niño
Maelzer et al. (p. 817) used the normalized difference in surface atmospheric pressure between Tahiti and Darwin (Southern Oscillation Index) in constructing a model to predict the outbreaks of Ross River virus epidemics in Australia. The authors conclude that epidemics of arboviral disease can be predicted on the basis of climate relationships.
Reproductive Toxicity of Coumestrol
Rodent experiments by Ashby et al. (p. 819) confirm that coumestrol causes uterine hyperplasia and increases in uterine DNA content. The authors conclude that the uterotrophic activity of the phytoestrogen coumestrol in the immature intact rat is typical of the activity of the natural estrogen estradiol.
Organochlorines in Human Tissues
Dewailly et al. (p. 823) examine organochlorines in human tissue autopsy samples of Greenlanders and report concentrations of certain pesticides are 3- to 34-fold higher in native Inuits than in Quebec City Canadians. The DDE body burden of Inuits was unchanged over the last two decades, whereas DDT decreased by a factor of five. Organochlorine body burdens in Inuits are presently among the highest on earth.
Inhibition of Ciliary Function by Particles
Mucociliary clearance of inhalable particles collected from urban air in São Paulo, Brazil, was measured using a frog palate preparation by Macchione et al. (p. 829). Exposure to urban aerosol particles (PM10) for a short time altered functional, biochemical, and morphologic parameters in the ciliated frog palate; similar responses would help explain some of the short-term health effects experienced by humans exposed to polluted urban air.
Risk of Herpes Zoster from Chemical Exposure
A telephone survey of 1,642 residents near a North Carolina Superfund site was conducted by Arndt et al. (p. 835). The Aberdeen pesticides dumps site contains organochlorine pesticides, volatile organic compounds, and metals. The authors report a potential association between chemical exposure and immune suppression in the residents when herpes zoster was used as a marker of immune suppresion.
PCBs Affect Thyroid Hormones in Children
The potential associations between blood PCBs, lead, cadmium, and urinary mercury to thyroid hormones in German children were investigated by Osius et al. (p. 843). The authors report that PCBs and cadmium may influence thyroid hormones in children and suggest that future studies are warranted.
Benzene Toxicity
Baak et al. (p. 851) describe aplastic anemia in a petrochemical factory worker who had been exposed to low-level benzene (and perhaps high-level benzene for short periods) during the production and handling of petroleum resin products. The authors suggest that more research is needed to determine the toxicity of low-level benzene.
Last Updated: September 27, 1999
