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R Philen

Publications and source records attributed to R Philen.

4 recordsLinked to original sources
PubMed2001

Investigation of systemic lupus erythematosus in Nogales, Arizona.

In 1996, a citizens group in Nogales, Arizona, reported to the Arizona Department of Health their concerns about a possible excess prevalence of systemic lupus erythematosus (SLE) due to exposure to environmental contamination in the area. The authors conducted a two-phase study in which the objectives of phase I were to identify potential SLE cases and to determine the prevalence of SLE and the objectives of phase II were to identify potential risk factors associated with the development of SLE and to evaluate the possible association between SLE and environmental exposure to pesticides and inorganic compounds. Participants included 20 confirmed cases and 36 controls. The authors found the prevalence of SLE to be 103 cases per 100,000 population (95 percent confidence interval: 56, 149), two to seven times higher than the prevalence in the US population. They detected elevated levels of 1,1-dichloro-2,2-bis-(p-chorophenyl)ethylene and organophosphate metabolites among cases and controls. In both, levels were higher than the reference mean for the US population. The authors found no statistical association between elevated levels of pesticides and disease status. Their results show that the prevalence of SLE in Nogales is higher than the reported prevalence in the US population and that both cases and controls had past exposure to chlorinated pesticides and have ongoing exposure to organophosphates.

Arizona↗
PubMed2001

Storage time and deodorization temperature influence the formation of aniline-derived compounds in denatured rapeseed oils.

In 1981 an epidemic, named Toxic Oil Syndrome, occurred in Spain as a result of ingestion of rapeseed oil denatured with 2% aniline, which had been imported for industrial use but was fraudulently diverted and processed for human consumption. Two groups of chemical compounds have been identified in the ingested toxic oil: fatty acid anilides and amino-propanediol derivatives. The objective of this work was to assess the effect of several refining process variables on the formation of 3-(N-phenylamino)-1,2-propanediol (PAP) esters. The amount of PAP esters in aniline-denatured oil increased dramatically when oil was heated from 250 degrees C to 300 degrees C. However, the ones formed when 300 degrees C was reached were lost during processing at that temperature. The level maintained during the operation time at 300 degrees C was higher in denatured samples stored for 3 weeks before refining than in denatured samples stored only for 1 week. Anilides were also analyzed. We found that anilides decreased very little with distillation time. In this paper we discuss the influence of storage time prior to refining and of elevated refining temperature, such as temperatures that might occur in close proximity to a deodorizer coil.

Aniline Compounds↗
PubMed2000

Workshop to identify critical windows of exposure for children's health: neurobehavioral work group summary.

This paper summarizes the deliberations of a work group charged with addressing specific questions relevant to risk estimation in developmental neurotoxicology. We focused on eight questions. a) Does it make sense to think about discrete windows of vulnerability in the development of the nervous system? If it does, which time periods are of greatest importance? b) Are there cascades of developmental disorders in the nervous system? For example, are there critical points that determine the course of development that can lead to differences in vulnerabilities at later times? c) Can information on critical windows suggest the most susceptible subgroups of children (i.e., age groups, socioeconomic status, geographic areas, race, etc.)? d) What are the gaps in existing data for the nervous system or end points of exposure to it? e) What are the best ways to examine exposure-response relationships and estimate exposures in vulnerable life stages? f) What other exposures that affect development at certain ages may interact with exposures of concern? g) How well do laboratory animal data predict human response? h) How can all of this information be used to improve risk assessment and public health (risk management)? In addressing these questions, we provide a brief overview of brain development from conception through adolescence and emphasize vulnerability to toxic insult throughout this period. Methodological issues focus on major variables that influence exposure or its detection through disruptions of behavior, neuroanatomy, or neurochemical end points. Supportive evidence from studies of major neurotoxicants is provided.

Adolescent↗