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Hans Drexler - One of the best experts on this subject based on the ideXlab platform.

  • unnecessary investigations in Environmental Medicine
    Deutsches Arzteblatt International, 2016
    Co-Authors: Annette Greiner, Hans Drexler
    Abstract:

    Background Patients in Environmental Medicine often want a thorough diagnostic evaluation of nonspecific symptoms. Unconventional testing, as well as conventional testing for indications other than the established ones, can lead to false diagnoses and, in turn, to substantial emotional, social, and financial harm. The goal of this single-center study was to assess inappropriate diagnostic testing among the patients of a specialized university outpatient clinic for Environmental Medicine. Methods The charts of 653 consecutive outpatients seen in the institute and outpatient clinic of occupational, social, and Environmental Medicine in Erlangen from 2010 to 2015 were evaluated, and inappropriate diagnostic tests were assessed. Results 9% of the patients had received at least one inappropriate diagnostic test. The most common one was an inappropriate heavy-metal test (26%), followed by an inappropriately ordered hair analysis (15%) and biomonitoring in the blood or urine with an erroneous choice of the testing matrix or an erroneous interpretation of the findings (15%). Biomonitoring performed by us did not confirm the suspected Environmental diagnosis in any case. Laboratory values exceeding the normal limits were rarer among these patients than in the patients for whom we considered biomonitoring to be indicated without any pretesting. Conclusion An appreciable number of patients in Environmental Medicine were subjected to inappropriate diagnostic testing. When this happens, proper testing often needs to be done thereafter in order to confirm or refute the findings. This phenomenon should be more thoroughly assessed and quantified.

  • radon in indoor spaces an underestimated risk factor for lung cancer in Environmental Medicine
    Deutsches Arzteblatt International, 2010
    Co-Authors: K Schmid, Torsten Kuwert, Hans Drexler
    Abstract:

    SUMMARY Background: Occupational Medicine has long recognized radon to be a cause of lung cancer, especially among miners working under ground. Until recently, however, little scientific evidence was available about the risk to the general population caused by indoor radon. Methods: The authors analyzed literature that they found by a selective search in the light of the recently published S1 guideline of the German Society of Occupational and Environmental Medicine (Deutsche Gesellschaft fur Arbeitsmedizin und Umweltmedizin) and a recent publication of the German Commission on Radiological Protection (Strahlenschutzkommission).

  • Quality assurance of biological monitoring in occupational and Environmental Medicine.
    Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2002
    Co-Authors: K. H. Schaller, Jay Angerer, Hans Drexler
    Abstract:

    Biological monitoring of chemical exposure in the workplace has become increasingly important in the assessment of health risk as an integral part of the overall occupational health and safety strategy. In Environmental Medicine biological monitoring plays also an important role in the assessment of excessive, acute or chronic exposure to chemical agents. To guarantee that the results obtained in biological monitoring are comparable with threshold limit values and results from other laboratories, the analysis must be carried out with tested and reliable analytical methods and accompanied by a quality assurance scheme. Confounding influences and interferences during the pre-analytical phase can be minimised by recommendations from experienced laboratories. For internal quality control commercially available control samples with an assigned concentration are used. External quality control programs for biological monitoring are offered by several institutions. The external quality control program of the German Society of Occupational and Environmental Medicine has been organised since 1982. In the meantime the 27th program has been carried out offering 96 analytes in urine, blood and plasma for 47 substances. This program covers most of the parameters relevant to occupational and Environmental Medicine. About 350 laboratories take part in these intercomparison programs. At present, ten German and 14 international laboratories are commissioned to determine the assigned values. The data evaluated from the results of the intercomparison programs give a good overview of the current quality of the determination of analytes assessed in occupational and Environmental toxicological laboratories. For the analysis of inorganic substances in blood and urine the tolerable variation ranges from 7.5 to 43.5%. For organic substances in urine the tolerable variation ranges from 12 to 48%. The highest variations (36-60%) were found for the analysis of organochlorine compounds in plasma. The tolerable variations for the determination of solvents in blood by head space gas chromatography range from 26 to 57%. If the recommendations for the pre-analytical phase, the selection of reliable analytical methods by the laboratory and the carrying out of adequate quality control are observed, the pre-requisites for reliable findings during biological monitoring are fulfilled

  • hemoglobin adducts of ethylene oxide propylene oxide acrylonitrile and acrylamide biomarkers in occupational and Environmental Medicine
    Toxicology Letters, 2002
    Co-Authors: Thomas Schettgen, Jurgen Angerer, Horst Christoph Broding, Hans Drexler
    Abstract:

    In a chemical plant, ethylene oxide (EO) and propylene oxide (PO) were used for the production of surfactants for the textile industry. Within health supervision, we investigated the internal exposure of the workers using hemoglobin adducts as parameters of biochemical effects. The 95th percentile for N-2-hydroxyethylvaline (HEV) was 1280 pmol/g globin (=29.4 microg/l blood) in blood from exposed workers compared with 100 pmol/g globin (or 2.3 microg/l) in controls. N-(R,S)-2-hydroxypropylvaline (HPV) both in workers and controls was below the detection limit (80 pmol/g globin or 2 microg/l). The levels of the adducts of acrylonitrile (ACN) and acrylamide (AA) were also determined, though they were mainly accounted for by smoking and diet. Median values of N-2-cyanoethylvaline (CEV) were below 4 pmol/g globin (or 0.1 microg/l) in non-smokers (n=24) and 131 pmol/g globin (or 3.3 microg/l) in smokers (n=38). Median values of N-2-carbamoylethylvaline (AAV) were 22 pmol/g globin (or 0.6 microg/l) in non-smokers compared with 89 pmol/g globin (or 2.4 microg/l) in smokers. Correlations were found between smoking habits and adduct levels of CEV and AAV.

  • new gas chromatographic mass spectrometric method for the determination of urinary pyrethroid metabolites in Environmental Medicine
    Journal of Chromatography B: Biomedical Sciences and Applications, 2002
    Co-Authors: Thomas Schettgen, Hans Drexler, Holger M Koch, Jurgen Angerer
    Abstract:

    We have developed and validated a new, reliable and very sensitive method for the determination of the urinary metabolites of the most common pyrethroids in one analytical run. After acidic hydrolysis for the cleavage of conjugates, the analytes cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl 2 CA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (trans-Cl 2 CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Br 2 CA), 4-fluoro-3-phenoxybenzoic acid (F-PBA) and 3-phenoxybenzoic acid (3-PBA) were extracted from the matrix with a liquid-liquid extraction procedure using n-hexane under acidic conditions. For further clean-up, NaOH was added to the organic phase and the carboxylic acids were re-extracted into the aqueous phase. After acidification and extraction into n-hexane again, the metabolites were then derivatised to volatile esters using N-tert.-butyldimethylsilyl-N-methyltrifluoroacetamid (MTBSTFA). Separation and detection were carried out using capillary gas chromatography with mass-selective detection (GC-MS). 2-Phenoxybenzoic acid (2-PBA) served as internal standard for the quantification of the pyrethroid metabolites. The limit of detection for all analytes was 0.05 μg/l urine. The RSD of the within-series imprecision was between 2.0 and 5.4% at a spiked concentration of 0.4 μg/l and the relative recovery was between 79.3 and 93.4%, depending on the analyte. This method was used for the analysis of urine samples of 46 persons from the general population without known exposure to pyrethroids. The metabolites cis-Cl 2 CA, trans-Cl 2 CA and 3-PBA could be found in 52, 72 and 70% of all samples with median values of 0.06, 0.11 and 0.16 μg/l, respectively. Br 2 CA and F-PBA could also be detected in 13 and 4% of the urine samples.

Christine Schulz - One of the best experts on this subject based on the ideXlab platform.

  • reference values for metabolites of pyrethroid and organophosphorous insecticides in urine for human biomonitoring in Environmental Medicine
    International Journal of Hygiene and Environmental Health, 2006
    Co-Authors: Ursel Heudorf, Christine Schulz, Werner Butte, Jurgen Angerer
    Abstract:

    Pesticides are widely used throughout the world in agriculture to protect crops, and in public health to control diseases transmitted by vectors or intermediate hosts. After the prohibition of organochlorines, such as DDT, today mainly pyrethroids and organophosphorous insecticides are used. With reliable and sensitive analytical methods for detecting metabolites of organophosphorous and pyrethroid insecticides in urinary specimens of the general population several studies have been published on internal exposure to these insecticides of the population in Germany. In total, data on levels of metabolites of organophosphorous acids in urine of about 1200 children and adults have been published, as well as data on levels of pyrethroid metabolites in urine of about 2100 children and adults. In Germany, reference values for Environmental pollutants related to the population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency, preferably based on data gained by representative studies. Reference values are defined as the 95th percentile, rounded off within the 95% confidence interval of the population studied. Since there is a need for reference values to characterise the population's exposure to organophosphates and pyrethroids, and since there are different studies available from Germany that agree quite well with data from other industrialised countries, the Commission has derived reference values from the available data, though none of the studies had fulfilled criteria on representativity. Reference values for metabolites of organophosphorous acids are as follows: DMP 135 microg/l, DMTP 160 microg/l and DEP 16 microg/l and for metabolites of pyrethroids: cis-Cl2CA 1 microg/l, trans-Cl2CA 2 microg/l and 3-PBA 2 microg/l. As the volume-related concentrations of organophosphate and pyrethroid metabolites show no significant age-dependence, the reference values derived are not age-stratified. Though based merely on statistical and not on toxicological data, levels analysed above the reference levels, when reliably measured (verified several times), should prompt Environmental health practitioners to search for sources, within the bounds of proportionality. In addition to accidental poisoning, possible sources include indoor contamination following improper pest control operations in homes as well as in pets and food products contaminated by these pesticides.

  • revised and new reference values for arsenic cadmium lead and mercury in blood or urine of children basis for validation of human biomonitoring data in Environmental Medicine
    International Journal of Hygiene and Environmental Health, 2006
    Co-Authors: Michael Wilhelm, Christine Schulz, Michael Schwenk
    Abstract:

    Reference values for Environmental pollutants in the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The reference values (defined as 95th percentile) are usually derived from results of the German Environmental Surveys (GerES). However, current reference values for children are lacking since GerES II conducted in 1990/92 and additionally the first German Environmental Survey on Children (GerES IV) will not be finished until the end of 2006. As an interim solution, the commission derived in 2005 reference values for children aged 6-12 years from a survey performed in south-west Germany in 2002/03 (508 children) and the pilot study for GerES IV 2001/2002 (252 children). A new reference value of 15 microg/l for children was derived for arsenic in urine. The reference values for cadmium in whole blood (0.5 microg/l) and for cadmium in urine (0.5 microg/l) were confirmed. The following reference values were lowered: for lead in blood from 60 to 50 microg/l, for mercury in whole blood from 1.5 to 1.0 microg/l and for mercury in urine from 1.4 to 0.7 microg/l.

  • revised and new reference values for some trace elements in blood and urine for human biomonitoring in Environmental Medicine
    International Journal of Hygiene and Environmental Health, 2004
    Co-Authors: Michael Wilhelm, Ulrich Ewers, Christine Schulz
    Abstract:

    Reference values for Environmental pollutants related to the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The reference values for arsenic, cadmium, lead, mercury and platinum in blood or urine were derived from the German Environmental Survey 1998 (adults aged 18-69 years). The reference value for lead in blood was lowered for females from 90 to 70 micrograms/l and for males from 120 to 90 micrograms/l, while the values for cadmium of 1.0 and for mercury of 2.0 micrograms/l in blood remained unchanged. For cadmium in urine the reference value was lowered from 1.5 to 0.8 micrograms/l and for mercury in urine from 1.4 to 1.0 micrograms/l. New reference values were derived for arsenic (15 micrograms/l) and platinum in urine (0.01 microgram/l). Additionally, for nickel in urine a new reference value of 3.0 micrograms/l based on data from the literature was established. Reference values for estimation of the selenium status were summarized from the literature. For aluminium in blood or urine no reference values were derived and the use of human biomonitoring to estimate aluminium exposure in Environmental Medicine is not recommended.

  • revised and new reference values for some persistent organic pollutants pops in blood for human biomonitoring in Environmental Medicine
    International Journal of Hygiene and Environmental Health, 2003
    Co-Authors: Michael Wilhelm, Ulrich Ewers, Christine Schulz
    Abstract:

    Abstract Reference values for Environmental pollutants related to the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The revised and new reference values for organochlorine compounds in whole blood are derived from the German Environmental Survey 1998 (adults aged 18 – 69 years) and from a survey performed with children (age 9 – 11 years) in south-west Germany 1998/99. The levels of organochlorine compounds in blood of adults increased with increasing age. Therefore the reference values are revised for different age groups (age groups: 18 – 19, 20 – 29, 30 – 39, 40 – 49, 50 – 59, 60 – 69). The reference values for PCB 138 in whole blood range from 0.4 to 2.2 μg/l, for PCB 153 from 0.6 to 3.3 μg/l, for PCB 180 from 0.3 to 2.4 μg/l, for β-HCH from 0.3 to 0.9 μg/l and for HCB from 0.4 to 5.8 μg/l. The reference values for DDE among adults in East Germany are higher compared to those in West Germany. The reference values of DDE in blood for adults in West Germany increase from 1.5 μg/l to 11 μg/l for the different age groups. The corresponding results for East Germany are 3 and 31 μg/l. The following reference values in blood of children (age 9 – 11 years) are recommended: 0.3 μg/l for PCB 138, 0.4 μg/l for PCB 153, 0.3 μg/l for PCB 180, 0.9 μg/l for sum of PCB (138+153+180), 0.3 μg/l for β-HCH, 0.3 μg/l for HCB and 0.7 μg/l for DDE. In comparison with the former evaluation the revised reference values for PCB, β-HCH and HCB levels in blood were reduced especially for younger adults

Alessandro Miani - One of the best experts on this subject based on the ideXlab platform.

  • Indoor air quality at school and students' performance: Recommendations of the UNESCO Chair on Health Education and Sustainable Development & the Italian Society of Environmental Medicine (SIMA).
    Health promotion perspectives, 2020
    Co-Authors: Manuela Pulimeno, Prisco Piscitelli, Salvatore Colazzo, Annamaria Colao, Alessandro Miani
    Abstract:

    The issue of indoor air quality (IAQ) concerns 64 million students across Europe, but it is still a neglected topic, although it impacts both their health and learning outcomes. Classroommicroclimate is the first key factor determining a healthy or unhealthy school environment, and it is influenced by ventilation, temperature and humidity rate. Classrooms are usually crowded, overheated and poorly ventilated, thus resulting in possible increases of carbon dioxide (CO2), that can cause several problems when its concentrations exceed the value of 0.15 percentage volume of CO2 (1500 ppm) or even at lower levels (1000 ppm). CO2 can also arise from outside the school, being widely produced by the combustion of fossils or road traffic. Anthropogenic activities are responsible for the emission of nitrogen dioxide (NO2) and polycyclic aromatic hydrocarbons(PAH) too, which represent other possible external contaminants potentially impairing IAQ. Furtherdangerous exposures for students' health are those related to natural emission of gas Radon, which typically accumulates in poorly ventilated classrooms, and volatile organic compounds (VOCs, released by building materials, paints, furnishings, detergents), while chemicals substances (i.e.cyanoacrylate, lead, cadmium, nickel) might be contained in school materials. Finally, particulate matter (PM2.5 and PM10) originating from road traffic, domestic heating or industrial activities represent additional possible contaminants impacting schools' air quality. Poor IAQ might result in mild adverse events (i.e. headaches, nausea etc.) or cause respiratory problems. More frequently, IAQ affects students' attention and their school performances, as widely documented by many studies. Standardized tests administered to pupils exposed to poor IAQ (to assess reading and mathematical abilities) systematically result in worse outcomes compared to students staying in healthy classroom environments. In this paper, we present recommendations of UNESCO Chair on Health Education and Sustainable Development and Italian Society of Environmental Medicine(SIMA) to ensure an optimal IAQ at school, including some post-COVID-19 issues.

  • Indoor air quality at school and students’ performance:Recommendations of the UNESCO Chair on Health Education and Sustainable Development & the Italian Society of Environmental Medicine (SIMA)
    'Maad Rayan Publishing Company', 2020
    Co-Authors: Manuela Pulimeno, Prisco Piscitelli, Salvatore Colazzo, Annamaria Colao, Alessandro Miani
    Abstract:

    The issue of indoor air quality (IAQ) concerns 64 million students across Europe, but it is still a neglected topic, although it impacts both their health and learning outcomes. Classroom microclimate is the first key factor determining a healthy or unhealthy school environment, and it is influenced by ventilation, temperature and humidity rate. Classrooms are usually crowded, overheated and poorly ventilated, thus resulting in possible increases of carbon dioxide (CO2), that can cause several problems when its concentrations exceed the value of 0.15 percentage volume of CO2 (1500 ppm) or even at lower levels (1000 ppm). CO2 can also arise from outside the school, being widely produced by combustion of fossils or road traffic. Anthropogenic activities are responsible for the emission of nitrogen dioxide (NO2) and polycyclic aromatic hydrocarbons (PAH) too, which represent other possible external contaminants potentially impairing IAQ. Further dangerous exposures for students\u2019 health are those related to natural emission of gas Radon, which typically accumulates in poorly ventilated classrooms, and volatile organic compounds (VOCs, released by building materials, paints, furnishings, detergents), while chemicals substances (i.e. cyanoacrylate, lead, cadmium, nickel) might be contained in school materials. Finally, particulate matters (PM2.5 and PM10) originating from road traffic, domestic heating or industrial activities represent additional possible contaminants impacting schools\u2019 air quality. Poor IAQ might result in mild adverse events (i.e. headaches, nausea etc.) or cause respiratory problems. More frequently, IAQ affects students\u2019 attention and their school performances, as widely documented by many studies. Standardized tests administered to pupils exposed to poor IAQ (to assess reading and mathematical abilities) systematically result in worse outcomes compared to students staying in healthy classroom environments. In this paper, we present recommendations of UNESCO Chair on Health Education and Sustainable Development and Italian Society of Environmental Medicine (SIMA) to ensure an optimal IAQ at school, including some post-COVID-19 issues

Claudia Traidlhoffmann - One of the best experts on this subject based on the ideXlab platform.

  • multiple chemical sensitivity mcs a guide for dermatologists on how to manage affected individuals
    Journal Der Deutschen Dermatologischen Gesellschaft, 2020
    Co-Authors: Katharina Harter, Gertrud Hammel, Megan Fleming, Claudia Traidlhoffmann
    Abstract:

    Multiple chemical sensitivity (MCS) is a condition characterized by a subjectively perceived increase in sensitivity to Environmental chemicals. Individuals affected report a wide variety of nonspecific complaints, and frequently attribute cutaneous and mucosal symptoms to chemical exposures. Dermatologists should therefore be familiar with this condition. MCS is a diagnosis of exclusion. Other causes for the patients' symptoms should be ruled out by routine laboratory tests, allergy tests and, if indicated, monitoring for toxic (Environmental) substances. The primary job of dermatologists is to rule out skin diseases or hypersensitivities as possible causes of the complaints. Interdisciplinary patient management is essential, especially in severe cases in which those affected have problems coping with everyday life. Relevant specialties in this context include Environmental Medicine, psychosomatic Medicine as well as occupational and social Medicine. Cutaneous symptoms are usually addressed with symptomatic treatment using basic skin care products. There are currently no evidence-based treatment recommendations for MCS. It is crucial that MCS patients be protected from unnecessary treatments and thus from mental, social and financial strain. In addition to medical skills, managing MCS patients requires communicative and psychosocial competence in particular. Physicians involved in the treatment will benefit from training in psychotherapy. Irrespective of the mechanisms that lead to MCS, diagnosis and treatment of this condition require an actively supportive attitude towards these patients, a good doctor-patient relationship and interdisciplinary cooperation.

Xiaoping Chen - One of the best experts on this subject based on the ideXlab platform.

  • molecular population genetics of human cyp3a locus signatures of positive selection and implications for evolutionary Environmental Medicine
    Environmental Health Perspectives, 2009
    Co-Authors: Xiaoping Chen, Haijian Wang, Gangqiao Zhou, Xiumei Zhang, Xiaojia Dong, Fuchu He
    Abstract:

    A key event in human population history is the dispersal of early humans from Africa to other parts of the world with different climates, pathogens, sources of food and xenobiotic exposure, and the dynamic adaptation to the evolving environments (Jin and Su 2000). Current phenotypic differences between individuals/groups could be due partly to functional polymorphisms that facilitated survival in the ancestral populations (Di Rienzo and Hudson 2005). Resolving the underlying allelic architectures of Environmental response and searching for their molecular adaptation to selective forces have been attractive indirect strategies for implementation and interpretation of genetic analysis of Environmental response and complex disorders (Bamshad and Wooding 2003; Sabeti et al. 2007). Members of the cytochrome P450 (CYP) 3A family are among the most important CYP enzymes in humans. They metabolize various endogenous and exogenous chemicals, such as clinically important drugs, Environmental carcinogens, cholesterol, steroids, and other lipids (Wojnowski 2004). Members of the CYP3A family are expressed in organs primarily associated with xenobiotic and hormone disposition, such as the liver and gastrointestinal tract (Wojnowski 2004). Four functional CYP3A enzymes—CYP3A4, CYP3A5, CYP3A7, and CYP3A43—have been identified in humans. CYP3A4 is most abundant in adult liver and intestine and is the major enzyme involved in xenobiotic and drug metabolism (Fujita 2004). CYP3A5 is the predominant form in the kidney (Givens et al. 2003). CYP3A7, a fetoplacental enzyme found only in humans, is expressed mainly in fetal liver (Leeder et al. 2005) and extrahepatic tissues such as endometrium and placenta (Burk et al. 2002; Schuetz et al. 1993). The more recently cloned CYP3A43 is expressed predominantly in prostate and testis (Gellner et al. 2001). Interindividual variation in CYP3A activity up to 10-fold has been observed (Dorne et al. 2003). Because CYP3A activity is a major determinant of drug response and may be associated with risk for cancers such as breast and prostate cancer (Keshava et al. 2004), the identification of sequence variants at the CYP3A locus and functional characterization of their clinical relevance have been of long-standing interest in pharmacogenetics and toxicogenetics. The human CYP3A gene cluster resides in a 231-kb region on chromosome 7q22 and consists of four genes and two pseudogenes, arranged in the order of CYP3A5, CYP3A5P1, CYP3A7, CYP3A5P2, CYP3A4, and CYP3A43, from centromere to telo mere (Finta and Zaphiropoulos 2000) (Figure 1). CYP3A43 is in the opposite orientation from all other CYP3A genes. Each intact gene encodes a protein consisting of 503 amino acids. Finta and Zaphiropoulos (2000) suggested that the locus arose through duplication of an ancestral CYP3A cassette of 40–50 kb. Many genetic variants have been identified in this locus and are available online (http://www.imm.ki.se/CYPalleles/); some functional variants for CYP3A have been reported, such as the CYP3A5*3, which results in an incorrectly spliced mRNA and a truncated nonfunctional protein (Kuehl et al. 2001). Figure 1 Genomic structure of genes and pseudogenes at the CYP3A locus. Abbreviations: Cen, centromere; Qtel, telomere. Exons for genes and pseudogenes are shown as boxes; arrows indicate transcriptional orientation; and broken lines indicate resequenced regions. ... Parallel to exploring phenotypic effects and clinical relevance of CYP3A genetic polymorphisms, investigating molecular adaptations to the environment is an intriguing complementary strategy for pharmacogenetic and toxicogenetic studies. The CYP3A4 and CYP3A5 genes have a strong haplotype structure at varying frequencies across ethnic groups (Thompson et al. 2004). Using a comparative genomics approach and sequence-based neutrality test, Thompson et al. (2004) reported evidence of positive selection on the derived allele of the functional CYP3A5*3 in non-African populations and significant correlation of its allelic frequency with distance from the equator. In a genotype-based investigation on the CYP3A locus, Schirmer et al. (2006) proposed that negative natural selection acted primarily toward the elimination in non-African populations of the ancestral CYP3A4*1B allele rather than toward the reduction of CYP3A5 expression described by Thompson et al. (2004). It should be noted that these population genetics studies were based on a small fraction of sequence information or on only limited data of genotypes of single-nucleotide polymorphisms (SNPs), and both had limited coverage of the 230-kb genomic sequence of CYP3A locus. Therefore, the refined molecular targets of natural selection on the complete CYP3A locus and its evolutionary dynamics with respect to geographically and temporally fluctuating environments in our demographic history have not yet been explicitly pinpointed. To further identify genetic variations in the human CYP3A locus and assess the effect of natural selection on the pattern of nucleotide diversity at this locus, we resequenced the human CYP3A locus in three populations and addressed evolutionary population genetics on the gene cluster.

  • molecular population genetics of human cyp3a locus signatures of positive selection and implications for evolutionary Environmental Medicine
    Environmental Health Perspectives, 2009
    Co-Authors: Xiaoping Chen, Haijian Wang, Gangqiao Zhou, Xiumei Zhang, Xiaojia Dong, Lianteng Zhi, Li Jin
    Abstract:

    BackgroundThe human CYP3A gene cluster codes for cytochrome P450 (CYP) subfamily enzymes that catalyze the metabolism of various exogenous and endogenous chemicals and is an obvious candidate for e...