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Bowler RM, Yeh CL, Adams SW, Ward EJ, Ma RE, Dharmadhikari S, Snyder SA, Zauber SE, Wright CW, Dydak U. Association of MRI T1 relaxation time with neuropsychological test performance in manganese- exposed welders. Neurotoxicology 2018; 64:19-29. [PMID: 28587807 PMCID: PMC5905426 DOI: 10.1016/j.neuro.2017.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 05/23/2017] [Accepted: 05/30/2017] [Indexed: 01/07/2023]
Abstract
This study examines the results of neuropsychological testing of 26 active welders and 17 similar controls and their relationship to welders' shortened MRI T1 relaxation time, indicative of increased brain manganese (Mn) accumulation. Welders were exposed to Mn for an average duration of 12.25 years to average levels of Mn in air of 0.11±0.05mg/m3. Welders scored significantly worse than controls on Fruit Naming and the Parallel Lines test of graphomotor tremor. Welders had shorter MRI T1 relaxation times than controls in the globus pallidus, substantia nigra, caudate nucleus, and the anterior prefrontal lobe. 63% of the variation in MRI T1 relaxation times was accounted for by exposure group. In welders, lower relaxation times in the caudate nucleus and substantia nigra were associated with lower neuropsychological test performance on tests of verbal fluency (Fruit Naming), verbal learning, memory, and perseveration (WHO-UCLA AVLT). Results indicate that verbal function may be one of the first cognitive domains affected by brain Mn deposition in welders as reflected by MRI T1 relaxation times.
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Affiliation(s)
- R M Bowler
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA.
| | - C-L Yeh
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - S W Adams
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - E J Ward
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - R E Ma
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - S Dharmadhikari
- Department of Radiology and Imaging Sciences, Emory University Hospital,1364 Clifton Road, Atlanta, GA, 30322, USA
| | - S A Snyder
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Speech, Language and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907, USA
| | - S E Zauber
- Department of Neurology, Indiana University School of Medicine, 355 W 16th St, Indianapolis, IN 46202, USA
| | - C W Wright
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - U Dydak
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA; Department of Speech, Language and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907, USA.
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2
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Young MH, Green RL, Conkle JL, McCullough M, Devitt DA, Wright L, Vanderford BJ, Snyder SA. Field-scale monitoring of pharmaceutical compounds applied to active golf courses by recycled water. J Environ Qual 2014; 43:658-670. [PMID: 25602667 DOI: 10.2134/jeq2013.07.0299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The scarcity of potable water in arid and semiarid environments has led to the wider use of recycled water for irrigating agricultural fields, parks, golf courses, and other areas. One concern using recycled water as a source of irrigation has been the presence, fate, and transport of pharmaceutical compounds in water that percolates below the root zone of plants; however, very few multiyear field studies have been reported in the peer-reviewed literature. Here, we assessed compound mass flux of 13 pharmaceuticals in the fairways of four golf courses in the southwestern United States during a 2-yr field study. The sites varied by climate and soil type but were similar regarding turfgrass management. The results showed the presence of at least one pharmaceutical compound in nearly all samples collected, although concentrations were substantially lower after transport through the soil. Percent reduction in compound mass fluxes in drainage water was effectively 100% in 22 of 52 cases, 98 to 100% in 27 of 52 cases, and 73 to 94% in 3 of 52 cases (a case is defined as a specific compound measured at a specific site). Mass fluxes migrating below the root zone were calculated as <250 × 10 g ha for all compounds and >100 × 10 g ha in only two cases. For cases where the majority of the analyses were reportable, all fluxes were <8.80 × 10 g ha. Carbamazepine, meprobamate, and sulfamethoxazole were most commonly found in drainage water, representing nearly 80% of all reportable detections. This research demonstrates the potential of turfgrass/soil systems to reduce contaminant loading below the root zone and potentially toward groundwater.
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Makris KC, Andra SS, Jia A, Herrick L, Christophi CA, Snyder SA, Hauser R. Association between water consumption from polycarbonate containers and bisphenol A intake during harsh environmental conditions in summer. Environ Sci Technol 2013; 47:3333-43. [PMID: 23448553 DOI: 10.1021/es304038k] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
With the exception of polycarbonate (PC) baby bottles, little attention has been paid to bisphenol A (BPA) intake from packaged water consumption (PC water dispensers), especially during summer weather conditions. We determined the magnitude and variability of urinary BPA concentrations during summer in 35 healthy individuals largely relying upon PC packaged water to satisfy their potable needs. We used liquid chromatography-tandem mass spectrometry to measure urinary BPA concentrations. A questionnaire was administered in July/August and a spot urine sample was collected on the same day and 7 days after the completion of the interview (without intervention). Linear regression was performed to assess the association of variables, such as water consumption from different sources, on urinary BPA levels for the average of the two urine samples. A significant positive association (p = 0.017) was observed between PC water consumption and urinary BPA levels in females, even after adjusting for covariates in a multivariate regression model. The geometric mean of daily BPA intake back-calculated from urinary BPA data was 118 ng · (kg bw)(-1) · day(-1), nearly double the average intake levels observed in biomonitoring studies worldwide. High urinary BPA levels were partially ascribed to summer's high PC water consumption and weather characteristics (high temperatures, >40 °C; very high UV index values, >8), which could be causing BPA leaching from PC. It is suggested that PC-based water consumption could serve as a proxy for urinary BPA, although the magnitude of its relative contribution to overall daily intake requires further investigation.
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Affiliation(s)
- K C Makris
- Cyprus International Institute for Environmental and Public Health in association with Harvard School of Public Health, Cyprus University of Technology, Limassol, Cyprus.
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Drewes JE, Anderson P, Denslow N, Olivieri A, Schlenk D, Snyder SA, Maruya KA. Designing monitoring programs for chemicals of emerging concern in potable reuse--what to include and what not to include? Water Sci Technol 2013; 67:433-9. [PMID: 23168646 DOI: 10.2166/wst.2012.520] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This study discussed a proposed process to prioritize chemicals for reclaimed water monitoring programs, selection of analytical methods required for their quantification, toxicological relevance of chemicals of emerging concern regarding human health, and related issues. Given that thousands of chemicals are potentially present in reclaimed water and that information about those chemicals is rapidly evolving, a transparent, science-based framework was developed to guide prioritization of which compounds of emerging concern (CECs) should be included in reclaimed water monitoring programs. The recommended framework includes four steps: (1) compile environmental concentrations (e.g., measured environmental concentration or MEC) of CECs in the source water for reuse projects; (2) develop a monitoring trigger level (MTL) for each of these compounds (or groups thereof) based on toxicological relevance; (3) compare the environmental concentration (e.g., MEC) to the MTL; CECs with a MEC/MTL ratio greater than 1 should be prioritized for monitoring, compounds with a ratio less than '1' should only be considered if they represent viable treatment process performance indicators; and (4) screen the priority list to ensure that a commercially available robust analytical method is available for that compound.
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Affiliation(s)
- J E Drewes
- Colorado School of Mines, Advanced Water Technology Center (AQWATEC), Golden, CO, USA.
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Novak PJ, Arnold WA, Blazer VS, Halden RU, Klaper RD, Kolpin DW, Kriebel D, Love NG, Martinović-Weigelt D, Patisaul HB, Snyder SA, Vom Saal FS, Weisbrod AV, Swackhamer DL. On the need for a National (U.S.) research program to elucidate the potential risks to human health and the environment posed by contaminants of emerging concern. Environ Sci Technol 2011; 45:3829-3830. [PMID: 21438522 DOI: 10.1021/es200744f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Affiliation(s)
- P J Novak
- Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Abstract
Stringently controlled in vitro experiments are a necessary part of translational research. Cell lines are useful for exploring the underlying biology of cancer. Very few canine soft tissue sarcoma cell lines exist. This report describes the establishment of a new canine soft tissue sarcoma cell line (MBSa1) derived from a high-grade, metastatic neurofibrosarcoma. The primary tumor tissue was obtained from a 12-year-old neutered male German Shepherd Dog and was maintained in tissue culture for a minimum of 20 passages over 7 months. MBSa1 was injected into athymic mice to determine tumorigenicity. Five million cells were injected into the subcutis of the right flank of athymic nude mice. Nine of the 10 mice grew tumors 1 cm or larger within 8 weeks of cell injection. The large number of in vitro passages coupled with solid tumor formation in athymic nude mice demonstrates that MBSa1 has been immortalized and is tumorigenic.
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Affiliation(s)
- S A Snyder
- Department of Clinical Sciences, North Carolina State University School of Veterinary Medicine, Raleigh, NC, USA
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Abstract
Human oncology has clearly demonstrated the existence of hypoxic tumours and the problematic nature of those tumours. Hypoxia is a significant problem in the treatment of all types of solid tumours and a common reason for treatment failure. Hypoxia is a negative prognostic indicator of survival and is correlated with the development of metastatic disease. Resistance to radiation therapy and chemotherapy can be because of hypoxia. There are two dominant types of hypoxia recognized in tumours, static and intermittent. Both types of hypoxia are important in terms of resistance. A variety of physiological factors cause hypoxia, and in turn, hypoxia can induce genetic and physiological changes. A limited number of studies have documented that hypoxia exists in spontaneous canine tumours. The knowledge from the human literature of problematic nature of hypoxic tumours combined with the rapid growth of veterinary oncology has necessitated a better understanding of hypoxia in canine tumours.
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Affiliation(s)
- S A Snyder
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
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Hardee ME, Kirkpatrick JP, Shan S, Snyder SA, Vujaskovic Z, Rabbani ZN, Dewhirst MW, Blackwell KL. Human recombinant erythropoietin (rEpo) has no effect on tumour growth or angiogenesis. Br J Cancer 2006; 93:1350-5. [PMID: 16288305 PMCID: PMC2361536 DOI: 10.1038/sj.bjc.6602846] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Tumour hypoxia has been shown to increase mutation rate, angiogenesis, and metastatic potential, and decrease response to conventional therapeutics. Improved tumour oxygenation should translate into increased treatment response. Exogenous recombinant erythropoietin (rEpo) has been recently shown to increase tumour oxygenation in a mammary carcinoma model. The mechanism of this action is not yet understood completely. The presence of Epo and its receptor (EpoR) have been demonstrated on several normal and neoplastic tissues, including blood vessels and various solid tumours. In addition, rEpo has been shown in two recent prospective, randomized clinical trials to negatively impact treatment outcome. In this study, we attempt to characterize the direct effects of rEpo on tumour growth and angiogenesis in two separate rodent carcinomas. The effect of rEpo on R3230 rat mammary adenocarcinomas, CT-26 mouse colon carcinomas, HCT-116 human colon carcinomas, and FaDu human head and neck tumours, all of which express EpoR, was examined. There were no differences in tumour growth or proliferation (measured by Ki-67) between placebo-treated and rEpo-treated tumours. In the mammary window chamber, vascular length density (VLD) measurements in serial images of both placebo-treated and Epo-treated rats revealed no difference in angiogenesis between the Epo-treated tumours and placebo-treated tumours at any time point. These experiments are important because they suggest that the recent clinical detriment seen with the use of Epo is not due to its tumour growth effects or angiogenesis. These studies also suggest that further preclinical studies need to examine rEpo's direct tumour effects in efforts to improve the therapeutic benefits of Epo in solid tumour patients.
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Affiliation(s)
- M E Hardee
- Department of Pathology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - J P Kirkpatrick
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - S Shan
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - S A Snyder
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - Z Vujaskovic
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - Z N Rabbani
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - M W Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
| | - K L Blackwell
- Department of Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
- Department of Hematology–Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA
- Departments of Medicine and Radiation Oncology, Duke University Medical Center, Box 3893, Durham, NC 27710, USA; E-mail:
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Rowe M, Snyder SA, Lyons CR, Alverson DC, Helman P, Veroff R, Ohls RK. 245 INFLAMMATORY MEDIATORS AS PREDICTORS OF NEONATAL SEPSIS. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Kannan K, Keith TL, Naylor CG, Staples CA, Snyder SA, Giesy JP. Nonylphenol and nonylphenol ethoxylates in fish, sediment, and water from the Kalamazoo River, Michigan. Arch Environ Contam Toxicol 2003; 44:77-82. [PMID: 12434221 DOI: 10.1007/s00244-002-1267-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A survey measuring concentrations of nonylphenol (NP) and its ethoxylates (NPEs) in fish was performed in the Kalamazoo River, Michigan, USA, in 1999. Of 183 fish analyzed, 59% had no detectable NP or NPE. Detected concentrations were reported to range from 3.3 (limit of detection) to 29.1 ng NP/g wet weight. To further explore the means of exposure of NP and NPE in the fish, concentrations of NP and its mono-through tri-ethoxylates (NPE(1-3)) were measured in fish, sediment, and water collected near two wastewater treatment plants on the Kalamazoo River in 2000. Samples were analyzed using exhaustive steam distillation with concurrent liquid extraction. Nonylphenol ethoxycarboxylates (NPE(1-3)C) were also analyzed in water. Concentrations of NP and NPEs in fish were less than the method detection limits (MDLs) in all the samples except one fish, which contained 3.4 ng NP/g wet weight, just above the detection limit of 3.3 ng/g. Three of 36 sediments and 1 of 24 water samples contained detectable concentrations of NP or NPE(1). NPE(2), NPE(3), and NPEC were not detected in water samples.
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Affiliation(s)
- K Kannan
- Department of Zoology, 213 National Food Safety and Toxicology Center, and Institute for Environmental Toxicology, Michigan State University, East Lansing 48824, USA.
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Abstract
OBJECTIVE The purpose of this study was to design and implement a transducer to measure accurately the isometric elbow moments produced by individuals with tetraplegia. DESIGN The device needed to be insensitive to off-axis moments and proximal joint motions and be capable of being used over a wide range of elbow and shoulder positions in an outpatient clinic setting. BACKGROUND Measurement of the smaller isometric moments produced by individuals with tetraplegia is especially sensitive to the errors that can be introduced by inaccurate lever arm determination, off-axis loads, and proximal joint motions. Devices traditionally utilized for quantifying isometric strength are difficult to implement for the spinal cord injured population. METHODS The elbow moment transducer consists of two four-bar parallelogram linkages joined by a lockable pivot. Strain gauges mounted on one beam of the parallelogram produce an output proportional to the elbow moment. RESULTS Calibration of the device indicates that it accurately quantifies isometric elbow moments over a range that is appropriate for evaluating elbow extension strength in individuals with tetraplegia. CONCLUSIONS A device was developed and implemented that accurately quantifies isometric elbow moments over a range that is appropriate for evaluating elbow extension strength in individuals with tetraplegia. RELEVANCE The ability to quantitatively evaluate elbow strength in persons with tetraplegia is useful for understanding and improving the clinical outcomes of rehabilitative interventions that involve the elbow.
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Affiliation(s)
- W D Memberg
- Louis B. Stokes Veterans' Affairs Medical Center, Cleveland, OH, USA.
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Snyder SA, Lanzen JL, Braun RD, Rosner G, Secomb TW, Biaglow J, Brizel DM, Dewhirst MW. Simultaneous administration of glucose and hyperoxic gas achieves greater improvement in tumor oxygenation than hyperoxic gas alone. Int J Radiat Oncol Biol Phys 2001; 51:494-506. [PMID: 11567826 DOI: 10.1016/s0360-3016(01)01654-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PURPOSE To test the feasibility of hyperglycemic reduction of oxygen consumption combined with oxygen breathing (O(2)), to improve tumor oxygenation. METHODS AND MATERIALS Fischer-344 rats bearing 1 cm R3230Ac flank tumors were anesthetized with Nembutal. Mean arterial pressure, heart rate, tumor blood flow ([TBF], laser Doppler flowmetry), pH, and pO(2) were measured before, during, and after glucose (1 or 4 g/kg) and/or O(2). RESULTS Mean arterial pressure and heart rate were unaffected by treatment. Glucose at 1 g/kg yielded maximum blood glucose of 400 mg/dL, no change in TBF, reduced tumor pH (0.17 unit), and 3 mm Hg pO(2) rise. Glucose at 4 g/kg yielded maximum blood glucose of 900 mg/dL, pH drop of 0.6 unit, no pO(2) change, and reduced TBF (31%). Oxygen tension increased by 5 mm Hg with O(2). Glucose (1 g/Kg) + O(2) yielded the largest change in pO(2) (27 mm Hg); this is highly significant relative to baseline or either treatment alone. The effect was positively correlated with baseline pO(2), but 6 of 7 experiments with baseline pO(2) < 10 mm Hg rose above 10 mm Hg after combined treatment. CONCLUSION We demonstrated the feasibility of combining hyperglycemia with O(2) to improve tumor oxygenation. However, some cell lines are not susceptible to the Crabtree effect, and the magnitude is dependent on baseline pO(2). Additional or alternative manipulations may be necessary to achieve more uniform improvement in pO(2).
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Affiliation(s)
- S A Snyder
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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Snyder SA, Villeneuve DL, Snyder EM, Giesy JP. Identification and quantification of estrogen receptor agonists in wastewater effluents. Environ Sci Technol 2001; 35:3620-5. [PMID: 11783637 DOI: 10.1021/es001254n] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Total concentrations of several known xenobiotic estrogen receptor (ER) agonists and natural and synthetic estrogen were measured in water by use of a combination of instrumental and bioanalytical approaches. Samples from 3 municipal wastewater treatment plants (WWTPs) in south central Michigan (upstream and effluent); 4 point source locations on the Trenton Channel of the Detroit River, MI; and 5 locations in Lake Mead, NV were analyzed. Organic compounds were extracted from 5 L water samples using solid-phase extraction disks and separated into three fractions based on polarity. Whole extracts and fractions were tested for ER agonist potency using the MVLN in vitro bioassay. ER agonist potency was characterized by comparing the magnitude of induction elicited by the extract or fraction to the maximum induction caused by 17beta-estradiol (E2). The greatest concentrations of ER agonists were associated with the most polar fraction (F3). Instrumental analyses and further fractionation were used to identify specific ER agonists associated with bioassay responses. Bioassay data were compared to extract concentrations in order minimize variability associated with the extraction procedure. Concentrations of endogenous estrogen, E2, and the synthetic estrogen ethynylestradiol (EE2) ranged from nondetectable to 14.6 ng/mL extract (nondetectable to 3.66 ng/L water) and represented from 88 to 99.5% of the total estrogen equivalents in the water samples analyzed. Concentrations of alkylphenols (APs) ranged from nondetectable to 148 microg/mL extract (nondetectable to 37,000 ng/L water). In general, alkylphenols contributed less than 0.5% of the total estrogen equivalents in the water samples. Both bioassay-directed fractionation results and comparison of ER agonist concentrations, adjusted for their known relative potencies, support the conclusion that E2 and EE2 were the dominant environmental estrogens in water samples from mid-Michigan and Lake Mead, NV.
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Affiliation(s)
- S A Snyder
- Department of Zoology, National Food Safety and Toxicology Center, Michigan State University, East Lansing 48824-1311, USA.
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Abstract
Bioconcentration of p-nonylphenol (NP) by fathead minnows was determined under laboratory conditions. Fish were exposed continuously for 42 days to 0.33, 0.93 and 2.36 microg NP/l in a flow-through system. NP was Soxhlet extracted from whole fish homogenates with dichloromethane (DCM). The resulting extract was concentrated and bulk lipids removed by gel permeation and silica-gel chromatography. Compounds were identified and quantified by reverse-phase high-pressure liquid chromatography (RP-HPLC) with fluorescence detection. Mass spectrometry was used for verification of peak assignments. Bioconcentration factors (BCFs) ranged from 245 to 380.
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Affiliation(s)
- S A Snyder
- Department of Zoology, Institute of Environmental Toxicology, National Food Safety and Toxicology Center, Michigan State University, East Lansing 48824-1311, USA.
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Snyder SA, Keith TL, Naylor CG, Staples CA, Giesy JP. Identification and quantitation method for nonylphenol and lower oligomer nonylphenol ethoxylates in fish tissues. Environ Toxicol Chem 2001; 20:1870-1873. [PMID: 11521811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Substantial research is currently focused on the toxicological effects of alkylphenol ethoxylates (APEs) and alkylphenols (APs) on aquatic animals. Considerable data are available on the concentrations of APEs and APs in river systems in the United States; however, few if any data are available on the tissue concentrations of fish living in these rivers. A reliable method for the analysis of nonylphenol (NP) and lower oligomer nonylphenol ethoxylates (NPE1-3) in fish tissues has been developed. Nonylphenol and NPE1-3 were extracted from fish tissues using extractive steam distillation. Normal phase high-performance liquid chromatography (HLPC) was used as a cleanup step prior to analysis by gas chromatography with mass selective detection (GC/MSD) using selected ion monitoring. Optimization of this technique resulted in consistent recoveries in excess of 70%, with the exception of NPE3 (17%). Method detection limits (MDLs) and limits of quantitation using the technique range from 3 to 20 and 5 to 29 ng/g wet weight, respectively. Nonylphenol and NPE1 were detected in subsamples (n = 6) of a single common carp captured in the Las Vegas Bay of Lake Mead (NV, USA) at average concentrations of 184+/-4 ng/g and 242+/-9 wet weight, respectively. Nonylphenol ethoxylates were not detected in the carp collected at Lake Mead.
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Affiliation(s)
- S A Snyder
- Department of Zoology and Institute for Environmental Toxicology, Michigan State University, East Lansing 48824, USA.
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Braun RD, Lanzen JL, Snyder SA, Dewhirst MW. Comparison of tumor and normal tissue oxygen tension measurements using OxyLite or microelectrodes in rodents. Am J Physiol Heart Circ Physiol 2001; 280:H2533-44. [PMID: 11356608 DOI: 10.1152/ajpheart.2001.280.6.h2533] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study we compare oxygen tension (Po 2) histograms measured with O2 microelectrodes and a new optical Po 2 measurement device, the OxyLite, in normal tissues (mouse spleen and thymus) and in tumors (R3230Ac in rats) ( n = 5–6). The transient response to glucose infusion or 100% O2 breathing (hyperoxia) was also measured in tumors. Po 2 histograms of spleen and thymus with the two devices were not different. The OxyLite tumor Po 2 histogram, however, was left-shifted compared with the microelectrode (median Po 21.0 vs. 4.0 mmHg, P = 0.016). Both probes responded to acute hyperglycemia with a mean increase of 3–6 mmHg, but the microelectrode change was not significant. The OxyLite consistently recorded large Po 2 increases (∼28 mmHg) with hyperoxia, whereas the microelectrode response was variable. The OxyLite averages Po 2 over an area that contains interstitial and vascular components, whereas the microelectrode measures a more local Po 2. This study demonstrates the importance of considering the features of the measurement device when studying tissues with heterogeneous Po 2 distributions (e.g., tumors).
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Affiliation(s)
- R D Braun
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Nichols KM, Snyder EM, Snyder SA, Pierens SL, Miles-Richardson SR, Giesy JP. Effects of nonylphenol ethoxylate exposure on reproductive output and bioindicators of environmental estrogen exposure in fathead minnows Pimephales promelas. Environ Toxicol Chem 2001; 20:510-522. [PMID: 11349851 DOI: 10.1897/1551-5028(2001)020<0510:eoneeo>2.0.co;2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nonylphenol ethoxylates (NPEOs) were evaluated in the laboratory for potential effects on the reproductive physiology and fecundity of fathead minnows (Pimephales promelas). Groups of three adult male and three female fathead minnows were exposed in a continuous flow-through system to 0, 0.21, 0.65, 2.1, or 7.9 microg NPEO/L for 42 d. Rabbit anti-goldfish vitellogenin (VTG) antiserum was prepared and a competitive enzyme-linked immunosorbent assay (ELISA) was adapted for measurement of plasma VTG in fish following exposure. Plasma 17beta-estradiol (E2) and testosterone (T) were also quantified by ELISA at the end of the exposure. Neither survival nor fecundity of fathead minnows exhibited a concentration-dependent response to NPEOs. No significant differences were observed in plasma VTG concentrations among treatments for males or females. Mean plasma VTG concentrations in females ranged from 291.7 to 895.1 microg VTG/ml among treatments and did not overlap with mean concentrations measured in the plasma of males, which ranged from less than the method detection limit (0.27 microg VTG/ml) to 3.2 microg VTG/ml. Plasma E2 concentrations exhibited a significant difference between males and females within all NPEO treatments, but no differences were observed among treatments. Similarly, plasma T concentrations did not exhibit a concentration-dependent response to NPEOs.
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Affiliation(s)
- K M Nichols
- Department of Fisheries and Wildlife, Michigan State University, East Lansing 48824, USA
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Keith TL, Snyder SA, Naylor CG, Staples CA, Summer C, Kannan K, Giesy JP. Identification and quantitation of nonylphenol ethoxylates and nonylphenol in fish tissues from Michigan. Environ Sci Technol 2001; 35:10-13. [PMID: 11351989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nonylphenol (NP) and its lower ethoxylates, nonylphenol monoethoxylate (NPE1) and nonylphenol diethoxylate (NPE2), can be present in aquatic environments at total concentrations of more than 10 microg/L. They are metabolites of nonylphenol polyethoxylates (NPE) and have been found to be weakly estrogenic. To evaluate bioaccumulation potential and identify potential risks posed by these chemicals, concentrations of NP, NPE1, NPE2, and nonylphenol triethoxylate (NPE3) were determined in the tissues of fish inhabiting various waters in Michigan. This method involves extraction of samples using exhaustive steam distillation with concurrent liquid extraction. Concentrations of NP among all sites and species ranged from <3.3 to 29.1 ng/g, ww and varied little among sites. NPE1 was detectable in some samples but at concentrations less than the method detection limit (16.8 ng/g). Concentrations of NPE2 and NPE3 in all samples were less than their respective MDLs of 18.2 and 20.6 ng/g.
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Affiliation(s)
- T L Keith
- Department of Zoology, National Food Safety and Toxicology Center, and Institute for Environmental Toxicology, Michigan State University, East Lansing 48824-1311, USA
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Nicolaou KC, Snyder SA, Simonsen KB, Koumbis AE. Model Studies towards Diazonamide A: Synthesis of the Heterocyclic Core We thank Dr. D. H. Huang, Dr. G. Suizdak, and Dr. R. Chadha for NMR spectroscopic, mass spectrometric, and X-ray crystallographic assistance, respectively. We also thank Professor R. H. Grubbs for a generous gift of catalyst 30. Financial support for this work was provided by The Skaggs Institute for Chemical Biology, the National Institutes of Health (USA), a predoctoral fellowship from the National Science Foundation (S.A.S.), postdoctoral fellowships from the Alfred Benzons Foundation and the Danish Natural Science Research Council (K.B.S.), and grants from Abbott, Amgen, ArrayBiopharma, Boehringer-Ingelheim, GlaxoWellcome, Hoffmann-LaRoche, DuPont, Merck, Novartis, Pfizer, and Schering Plough. Angew Chem Int Ed Engl 2000; 39:3473-3478. [PMID: 11091394 DOI: 10.1002/1521-3773(20001002)39:19<3473::aid-anie3473>3.0.co;2-e] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- KC Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology The Scripps Research Institute 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA) and Department of Chemistry and Biochemistry University of California San Diego 9500 Gilman Drive, La Jolla, CA 92093 (USA)
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Nicolaou KC, Koumbis AE, Snyder SA, Simonsen KB. Novel Reactions Initiated by Titanocene Methylidenes: Deoxygenation of Sulfoxides, N-Oxides, and Selenoxides We thank Drs. D. H. Huang and G. Suizdak for NMR spectroscopic and mass spectroscopic assistance, respectively. Financial support for this work was provided by The Skaggs Institute for Chemical Biology, the National Institutes of Health (USA), fellowships from the National Science Foundation (S.A.S.) and the Alfred Benzons Foundation (K.B.S.), and grants from Abbott, Amgen, Boehringer-Ingelheim, GlaxoWellcome, Hoffmann-LaRoche, DuPont, Merck, Novartis, Pfizer, and Schering Plough. Angew Chem Int Ed Engl 2000; 39:2529-2533. [PMID: 10941126 DOI: 10.1002/1521-3773(20000717)39:14<2529::aid-anie2529>3.0.co;2-e] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- KC Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology The Scripps Research Institute 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the north american great lakes : Part I: Structure of the scoring and ranking system (ESPR No. 1, 2000) DOI: http://dx.doi.org/10.1065/espr 199910.009 Part II: Bioaccumulation potential and persistence (ESPR No.2, 2000) DOI: http://dx.doi.org/10.1065/espr 199910.010 Part III: Acute and subchronic or chronic toxicity (ESPR No. 3, 2000) DOI: http://dx.doi.org/10.1065/espr199910.011 Part IV: Results from representative chemicals, sensitivity analysis, and discriminatory power (ESPR No. 4, 2000). Environ Sci Pollut Res Int 2000; 7:51. [PMID: 20490936 DOI: 10.1007/bf03000666] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- E M Snyder
- Department of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, 48824, East Lansing, MI, USA
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes. Part I: Structure of the scoring and ranking system. Environ Sci Pollut Res Int 2000; 7:52-61. [PMID: 19153841 DOI: 10.1007/bf03028072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1999] [Accepted: 09/06/1999] [Indexed: 05/27/2023]
Abstract
Hundreds of chemical contaminants have been identified in the Great Lakes System of North America. Depending on the agency or organization, various subset lists of these contaminants have been identified as chemicals of potential concern. However, there is no agreement on the method that should be used to make management decisions. Except for consensus on approximately 40 chemicals that most North American agencies agree can cause deleterious effects if released into the environment, no agreement has been reached regarding the priority that contaminants should receive for further action. That leaves hundreds of chemicals that have been, are being, or potentially could be released into the environment that have not been evaluated yet. A profile for potential chemicals of concern is generally thought to include persistence in the environment, potential to bioaccumulate, and ability to cause toxic effects at environmentally relevant concentrations. Except for the International Joint Commission's definition of persistence (> 8 weeks residence time in air, water, soil or sediment), there is little concurrence about what defines these characteristics. For instance, the State of Michigan currently has no established definitions or profiles of persistent, bioaccumulative, toxic substances. Furthermore, there is no standard process to rank chemicals relative to these characteristics. The Chemical Scoring and Ranking Assessment Model (SCRAM) has been developed to provide a process to rank-order chemicals based on these characteristics. The SCRAM system was developed primarily for use in the Great Lakes region of North America and particularly in Michigan, but it is not site-specific. Use of this system may assist in pollution prevention activities and other future chemical control efforts, allowing attention to be focused first on those chemicals likely to present the greatest hazard.
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Affiliation(s)
- E M Snyder
- Dept. of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, East Lansing, MI, USA
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes. Part II: Bioaccumulation potential and persistence. Environ Sci Pollut Res Int 2000; 7:116-21. [PMID: 19009433 DOI: 10.1065/espr199910.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1999] [Accepted: 09/06/1999] [Indexed: 05/27/2023]
Abstract
Part I (Snyder et al.: , 1999a) of this series introduced SCRAM, a chemical scoring and ranking system for contaminants of the North American Great Lakes. Here, in Part II, scoring of the bioaccumulation potential and persistence of chemicals is discussed, including acceptable types of data, specific scoring instructions, and the basis for criteria and scores for these categories of the system. Difficulties encountered during the process of determining which types of data adequately represent the properties of interest are discussed. Also, justification is given for an emphasis on scoring on the basis of persistence.
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Affiliation(s)
- E M Snyder
- Department of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, East Lansing, MI, USA
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes. Environ Sci Pollut Res Int 2000; 7:115. [PMID: 19009432 DOI: 10.1065/espr199910.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- E M Snyder
- Department of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, East Lansing, MI, USA
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes. Part III: Acute and subchronic or chronic toxicity. Environ Sci Pollut Res Int 2000; 7:176-84. [PMID: 19104881 DOI: 10.1065/espr199910.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1999] [Accepted: 09/06/1999] [Indexed: 05/27/2023]
Abstract
In Part I of this series (Snyder: et al., 1999a), the Chemical Scoring and Ranking Assessment Model (SCRAM) was introduced. This system produces scores for chemicals based on their bioaccumulation potential, environmental persistence, and toxicity. In Part II, scoring of the potential for a chemical to persist in the environment and bioaccumulate was described (Snyder et al., 1999b). In Part III, scoring of chemical toxicity is discussed, including definitions and descriptions of effects that are scored, specific scoring instructions, the basis for the criteria and scores, and specific conditions or concerns regarding the types of data used for scoring. A score for each chemical screened is determined from available test data from acute or subchronic and chronic toxicity tests conducted on aquatic and terrestrial organisms. Subchronic and chronic human health effects, including carcinogenicity, are also considered. Part IV includes an evaluation of the performance of the scoring and ranking system (Snyder: et al., 1999c).
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Affiliation(s)
- E M Snyder
- Dept. of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, East Lansing, MI, USA
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Snyder EM, Snyder SA, Giesy JP, Blonde SA, Hurlburt GK, Summer CL, Mitchell RR, Bush DM. SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes. Part IV: Results from representative chemicals, sensitivity analysis, and discriminatory power. Environ Sci Pollut Res Int 2000; 7:220-4. [PMID: 19005838 DOI: 10.1007/bf02987352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1999] [Accepted: 09/06/1999] [Indexed: 05/27/2023]
Abstract
The Chemical Scoring and Ranking Assessment Model (SCRAM) has been described in Parts I-III of this series (Snyder et al.: , 1999a; 1999b; 1999c). SCRAM is a chemical scoring and ranking (CSR) system that scores chemicals on the basis of bioaccumulation potential, environmental persistence, and toxicity. Part IV describes various tests and descriptions of the performance of this system. A group of 21 representative chemicals was chosen and scored to test the system. For those chemicals, the percentages of the scores associated with fate-related properties and associated with data uncertainty were determined. The scoring of four of these chemicals is described in greater detail, and the suitability of the scores is discussed. An analysis of the sensitivity of the system to incomplete data sets is presented. And finally, the discriminatory power of the system is described.
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Affiliation(s)
- E M Snyder
- Dept. of Zoology, Michigan State University, National Food Safety and Toxicology Center and Institute of Environmental Toxicology, East Lansing, MI, USA
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Abstract
INTRODUCTION The purpose of this study was to examine mothers' perceptions of the severity and susceptibility of their children to lead poisoning and to determine if a correlation existed between mothers' knowledge of lead poisoning and their children's blood lead levels. It was thought that mothers of children with lead poisoning (lead levels > or = 10 micrograms/dL) would score lower on a test of their perceptions and knowledge of lead poisoning than would mothers of children with normal lead levels (lead levels < or = 9 micrograms/dL). METHOD A cross-sectional study comparing scores of a questionnaire completed by mothers whose children had elevated blood lead levels and mothers whose children had normal blood lead levels was conducted. RESULTS No difference was found in the median test score between the 2 groups. For the correct responses on a question-by-question comparison, significant difference existed between groups; however, the percentage of correct responses was not always greater for the mothers of children with normal blood lead levels. DISCUSSION Mothers' perceptions and knowledge of lead poisoning were not associated with their children's blood lead levels.
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Affiliation(s)
- R L Anderson
- Department of Pediatrics, MetroHealth Medical Center, Cleveland, Ohio 44109-1998, USA
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Miles-Richardson SR, Pierens SL, Nichols KM, Kramer VJ, Snyder EM, Snyder SA, Render JA, Fitzgerald SD, Giesy JP. Effects of waterborne exposure to 4-nonylphenol and nonylphenol ethoxylate on secondary sex characteristics and gonads of fathead minnows (Pimephales promelas). Environ Res 1999; 80:S122-S137. [PMID: 10092426 DOI: 10.1016/s0166-445x(99)00009-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fathead minnows were exposed to 4-nonylphenol (NP) or nonylphenol ethoxylate (NPEO) to determine the effects of these weak estrogen agonists on secondary sex characteristics and gonads of sexually mature males and females during 42-day continuous-flow exposures. Neither NP nor NPEO caused statistically significant effects on tubercles or fatpad size at the concentrations tested. Exposure to 1. 1 or 3.4 micrograms NP/L caused changes in the number and size of Sertoli cells and germ cell syncytia. Necrotic aggregates of various stages of germ cells in the spermatogenic sequence were observed in the testes of males exposed to NP. Electron microscopy of the testes of NP-exposed males revealed the presence of phagocytic cells in the lumina of seminiferous tubules. The cytoplasm of some Sertoli cells was distended with myelin figures and necrotic spermatozoa. No significant effects on the stages of follicular development were observed in females exposed to NP. There were no differences in the gonads or secondary sex characteristics of males or females exposed to 5.5 micrograms NPEO/L, the greatest concentration studied. The histologic responses observed are sensitive indicators of waterborne exposure to NP at environmentally relevant concentrations, but not as sensitive as induction of plasma vitellogenin. The secondary sex characteristics were not affected by concentrations of NP or NPEO as great as 3.4 or 5.5 micrograms/L, respectively. Histologic responses occurred at concentrations that were less than the final chronic value based on survival and approximately the same as those required to cause effects on egg production. The histologic effects caused by NP were similar to, but not exactly the same as those caused by exposure of fathead minnows to 17 beta-estradiol.
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Affiliation(s)
- S R Miles-Richardson
- Department of Pathology, Michigan State University, East Lansing, Michigan, 48824-1222, USA
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Miles-Richardson SR, Pierens SL, Nichols KM, Kramer VJ, Snyder EM, Snyder SA, Render JA, Fitzgerald SD, Giesy JP. Effects of waterborne exposure to 4-nonylphenol and nonylphenol ethoxylate on secondary sex characteristics and gonads of fathead minnows (Pimephales promelas). Environ Res 1999; 80:S122-S137. [PMID: 10092426 DOI: 10.1006/enrs.1998.3945] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fathead minnows were exposed to 4-nonylphenol (NP) or nonylphenol ethoxylate (NPEO) to determine the effects of these weak estrogen agonists on secondary sex characteristics and gonads of sexually mature males and females during 42-day continuous-flow exposures. Neither NP nor NPEO caused statistically significant effects on tubercles or fatpad size at the concentrations tested. Exposure to 1. 1 or 3.4 micrograms NP/L caused changes in the number and size of Sertoli cells and germ cell syncytia. Necrotic aggregates of various stages of germ cells in the spermatogenic sequence were observed in the testes of males exposed to NP. Electron microscopy of the testes of NP-exposed males revealed the presence of phagocytic cells in the lumina of seminiferous tubules. The cytoplasm of some Sertoli cells was distended with myelin figures and necrotic spermatozoa. No significant effects on the stages of follicular development were observed in females exposed to NP. There were no differences in the gonads or secondary sex characteristics of males or females exposed to 5.5 micrograms NPEO/L, the greatest concentration studied. The histologic responses observed are sensitive indicators of waterborne exposure to NP at environmentally relevant concentrations, but not as sensitive as induction of plasma vitellogenin. The secondary sex characteristics were not affected by concentrations of NP or NPEO as great as 3.4 or 5.5 micrograms/L, respectively. Histologic responses occurred at concentrations that were less than the final chronic value based on survival and approximately the same as those required to cause effects on egg production. The histologic effects caused by NP were similar to, but not exactly the same as those caused by exposure of fathead minnows to 17 beta-estradiol.
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Affiliation(s)
- S R Miles-Richardson
- Department of Pathology, Michigan State University, East Lansing, Michigan, 48824-1222, USA
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Suarez WA, Snyder SA, Berman BB, Brittenham GM, Patel CR. Preclinical cardiac dysfunction in transfusion-dependent children and young adults detected with low-dose dobutamine stress echocardiography. J Am Soc Echocardiogr 1998; 11:948-56. [PMID: 9804099 DOI: 10.1016/s0894-7317(98)70136-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Transfusion-dependent (TD) patients develop cardiac iron overload that will eventually lead to cardiac pump failure. Low-dose dobutamine stress echocardiography may complement resting echocardiography and identify preclinical myocardial dysfunction caused by early cardiac hemosiderosis. Twenty-six iron-overloaded TD patients had stress echocardiography with 5 microg/kg per minute of dobutamine. Indexed left ventricular (LV) mass, LV dimensions, meridional wall stress, and cardiac index were significantly increased. TD patients had similar LV shortening fraction by M-mode (40.5% +/- 5.6% vs 39.4% +/- 4.5%) but had a lower mean LV ejection fraction (53.3% +/- 3.9% vs 46.8% +/- 6.9%, P < .002) and a subnormal increase in cardiac index during dobutamine stress (35% +/- 20% vs 11% +/- 16%, P < .0001). Impairment in LV relaxation was demonstrated by a prolonged isovolumetric relaxation time (0.060 +/- 0.005 vs 0.088 +/- 0.019 seconds, P < .0001), increased peak mitral E wave, and abnormal E/A ratio. Asymptomatic TD patients demonstrate decreased systolic functional reserve and abnormal left ventricular relaxation that may be caused by cardiac hemosiderosis. Low-dose dobutamine stress echocardiography may be useful for detecting and following cardiac dysfunction in patients at risk for cardiac hemosiderosis.
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Affiliation(s)
- W A Suarez
- Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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Cao F, Eckert R, Elfgang C, Nitsche JM, Snyder SA, H-ulser DF, Willecke K, Nicholson BJ. A quantitative analysis of connexin-specific permeability differences of gap junctions expressed in HeLa transfectants and Xenopus oocytes. J Cell Sci 1998; 111 ( Pt 1):31-43. [PMID: 9394010 DOI: 10.1242/jcs.111.1.31] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gap junctions provide direct intercellular communication by linking adjacent cells with aqueous pores permeable to molecules up to 1 kDa in molecular mass and 8–14 A in diameter. The identification of over a dozen connexins in the mammalian gap junction family has stimulated interest in the functional significance of this diversity, including the possibility of selectivity for permeants as seen in other channel classes. Here we present a quantitative comparison of channel permeabilities of different connexins expressed in both HeLa transfectants (rat Cx26, rat Cx32 and mouse Cx45) and Xenopus oocytes (rat Cx26 and rat Cx32). In HeLa cells, we examined permeability to two fluorescent molecules: Lucifer Yellow (LY: anionic, MW 457) and 4′,6-diamidino-2-phenylindole, dihydrochloride (DAPI, cationic, MW 350). A comparison of the kinetics of fluorescent dye transfer showed Cx32, Cx26 and Cx45 to have progressively decreasing permeabilities to LY, but increasing permeabilities to DAPI. This pattern was inconsistent with selection based on physical size of the probe, nor could it be accounted for by the differences between clones in the electrical conductance of the monolayers. In Xenopus oocytes, where electrical and dye coupling could be assessed in the same cells, Cx32 coupled oocytes showed an estimated 6-fold greater permeability to LY than those coupled by Cx26, a comparable result to that seen in HeLa cells, where an approximately 9-fold difference was seen. The oocyte system also allowed an examination of Cx32/Cx26 heterotypic gap junction that proved to have a permeability intermediate between the two homotypic forms. Thus, independent of the expression system, it appears that connexins show differential permeabilities that cannot be predicted based on size considerations, but must depend on other features of the probe, such as charge.
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Affiliation(s)
- F Cao
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260, USA
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Hahn JS, Braun RD, Dewhirst MW, Shan S, Snyder SA, Taube JM, Ong ET, Rosner GL, Dodge RK, Bonaventura J, Bonaventura C, DeAngelo J, Meyer RE. Stroma-free human hemoglobin A decreases R3230Ac rat mammary adenocarcinoma blood flow and oxygen partial pressure. Radiat Res 1997; 147:185-94. [PMID: 9008211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We examined the effect of a nitric oxide (NO) quencher, stroma-free human hemoglobin A (HbA0; 0.01, 0.05, 0.1, 0.2 g/kg), on the blood flow measured using the Doppler flow technique, tumor oxygen pressure (pO2) and the diameter of the arterioles using R3230Ac mammary adenocarcinoma as the tumor model. In female Fischer 344 rats with 1-cm-diameter tumors implanted in the lateral aspect of the left quadriceps, intravenous infusion of 0.1 and 0.2 g/kg HbA0 decreased both central tumor and peripheral tumor blood flow by 20-30% (P < 0.05). Tumor pO2 decreased 28% with 0.2 g/kg HbA0, from 15 mm Hg (baseline) to 11 mm Hg at 10 min (P = 0.02). Although 0.2 g/kg HbA0 increased blood flow 55% in the left quadriceps muscle proximal to the implanted tumor (P < 0.05), HbA0 had little effect on blood flow in right quadriceps muscle with no tumor implanted, and increased right quadriceps pO2, from 21 mm Hg (baseline) to 23 mm Hg at 10 min (P = 0.03). HbA0 increased mean arterial pressure 5-10% in a manner that was dependent on dose while heart rate concurrently decreased 9-19%. The diameter of the arterioles supplying the tumor was rapidly reduced 10% by 0.2 g/kg HbA0 (P = 0.037) and remained stable through 60 min of observation (P = 0.005). HbA0 selectively reduces tumor blood flow and tumor pO2 through vasoconstriction of the arterioles supplying the tumor. Vascular NO quenching provides an alternative to NO synthase inhibition as a means to achieve the goal of selective tumor hypoxia.
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Affiliation(s)
- J S Hahn
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Bean JM, Archer GE, Munley MT, Ong E, Snyder SA, Haroon ZA, McLendon RE, Marks LB, Stratford MRL, Chaplin DJ, Brizel DM, Bigner DD, Dewhirst MW. 2013 The impact of hypoxia and oxygenation modification on the radiation response of an intracranial rat glioma. Int J Radiat Oncol Biol Phys 1997. [DOI: 10.1016/s0360-3016(97)80782-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schmidt KA, Snyder SA. Effect of horizontal lithotomy position on hyperbaric tetracaine spinal anesthesia. Anesth Analg 1988; 67:894-6. [PMID: 3415002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- K A Schmidt
- Department of Anesthesiology, Hackensack Medical Center, New Jersey 07601
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