Association of MRI T1 relaxation time with neuropsychological test performance in manganese- exposed welders.

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.

Field-scale monitoring of pharmaceutical compounds applied to active golf courses by recycled water.

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.

Association between water consumption from polycarbonate containers and bisphenol A intake during harsh environmental conditions in summer.

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.

Designing monitoring programs for chemicals of emerging concern in potable reuse--what to include and what not to include?

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.

Carbonic anhydrase IX is a predictive marker of doxorubicin resistance in early-stage breast cancer independent of HER2 and TOP2A amplification.

BACKGROUND: In early-stage breast cancer, adjuvant chemotherapy is associated with significant systemic toxicity with only a modest survival benefit. Therefore, there is considerable interest in identifying predictive markers of response to therapy. Doxorubicin, one of the most common drugs used to treat breast cancer, is an anthracycline chemotherapeutic agent, a class of drugs known to be affected by hypoxia. Accordingly, we examined whether expression of the endogenous hypoxia marker carbonic anhydrase IX (CA IX) is predictive of outcome in early-stage breast cancer patients treated with doxorubicin. METHODS: We obtained 209 early-stage pre-treatment surgically-resected breast tumours from patients, who received doxorubicin in their chemotherapeutic regimen and had >10 years of follow-up. Immunohistochemistry was used to detect CA IX, and we used fluorescence in situ hybridisation to detect both human epidermal growth factor receptor (HER2) and DNA topoisomerase II-alpha (TOP2A) gene amplification. RESULTS: Carbonic anhydrase IX intensity was significantly correlated with progression-free survival (PFS) and overall survival (OS) in patients receiving 300 mg m(-2) of doxorubicin (HR=1.82 and 3.77; P=0.0014 and 0.010, respectively). There was a significant, inverse correlation between CA IX score and oestrogen receptor expression, but no significant correlations were seen with either HER2 or TOP2A ratio. CONCLUSION: We demonstrate that CA IX expression is correlated with worse PFS and OS for breast cancer patients treated with doxorubicin, independent of HER2 or TOP2A gene amplification. This study provides evidence that using CA IX to detect hypoxia in surgically-resected breast tumours may be of clinical use in choosing an appropriate chemotherapy regimen.

Establishment and characterization of a canine soft tissue sarcoma cell line.

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.

The role of hypoxia in canine cancer.

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.

Human recombinant erythropoietin (rEpo) has no effect on tumour growth or angiogenesis.

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.

Nonylphenol and nonylphenol ethoxylates in fish, sediment, and water from the Kalamazoo River, Michigan.

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.

A transducer to measure isometric elbow moments.

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.

Bioconcentration of nonylphenol in fathead minnows (Pimephales promelas).

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.

Simultaneous administration of glucose and hyperoxic gas achieves greater improvement in tumor oxygenation than hyperoxic gas alone.

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).

Identification and quantitation method for nonylphenol and lower oligomer nonylphenol ethoxylates in fish tissues.

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.

Effects of nonylphenol ethoxylate exposure on reproductive output and bioindicators of environmental estrogen exposure in fathead minnows Pimephales promelas.

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.

Identification and quantitation of nonylphenol ethoxylates and nonylphenol in fish tissues from Michigan.

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.

Comparison of tumor and normal tissue oxygen tension measurements using OxyLite or microelectrodes in rodents.

In this study we compare oxygen tension (PO2) histograms measured with O2 microelectrodes and a new optical PO2 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. PO2 histograms of spleen and thymus with the two devices were not different. The OxyLite tumor PO2 histogram, however, was left-shifted compared with the microelectrode (median PO2 1.0 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 PO2 increases (approximately 28 mmHg) with hyperoxia, whereas the microelectrode response was variable. The OxyLite averages PO2 over an area that contains interstitial and vascular components, whereas the microelectrode measures a more local PO2. This study demonstrates the importance of considering the features of the measurement device when studying tissues with heterogeneous PO2 distributions (e.g., tumors).

Identification and quantification of estrogen receptor agonists in wastewater effluents.

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.

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.

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.