bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant uptake of organic pollutants from soil: Bioconcentration estimates based on models and experiments
Authors: McKone Thomas E. , Maddalena Randy L. 
Published: November 2007

AbstractThe role of terrestrial vegetation in transferring chemicals from soil and air into specific plant tissues (e.g., stems, leaves, and roots) is still not well characterized. We provide here a critical review of plant-to-soil bioconcentration ratio (BCR) estimates based on models and experimental data. This review includes the conceptual and theoretical formulations of the BCR, constructing and calibrating empirical and mathematical algorithms to describe this ratio and the experimental data used to quantify BCRs and calibrate the model performance. We first evaluate the theoretical basis for the BCR concept and BCR models and consider how lack of knowledge and data limit reliability and consistency of BCR estimates. We next consider alternate modeling strategies for BCR. A key focus of this evaluation is the relative contributions to overall uncertainty from model uncertainty versus variability in the experimental data used to develop and test the models. As a case study, we consider a single chemical, hexahydro-1,3,5-trinitro-1,3,5-triazine, and focus on variability of bioconcentration measurements obtained from 81 experiments with different plant species, different plant tissues, different experimental conditions, and different methods for reporting concentrations in the soil and plant tissues. We use these observations to evaluate both the magnitude of experimental variability in plant bioconcentration and compare this to model uncertainty. Among these 81 measurements, the variation of the plant-to-soil BCR has a geometric standard deviation (GSD) of 3.5 and a coefficient of variation (CV; i.e., ratio of the arithmetic standard deviation to the mean) of 1.7. These variations are significant but low relative to model uncertainties, which have an estimated GSD of 10, with a corresponding CV of 14.
Experimental determination of bioconcentration, biotransformation, and elimination of linear alkylbenzene sulfonates inSolea senegalensis
Authors: Álvarez-Muñoz Diana , Sáez Mónica , Gómez-Parra Abelardo , González-Mazo Eduardo 
Published: November 2007

AbstractThe bioconcentration, biotransformation, and elimination of anionic surfactants, linear alkylbenzene sulfonates (LAS), specifically 2ØC10 and 2ØC12 LAS, which are pure isomers from two different homologues, have been characterized in Solea senegalensis using an experimental flow-through system with environmental exposure levels. The LAS and their carboxylated metabolites, sulfophenylcarboxylic acids (SPCs), were analyzed by pressurized liquid extraction, followed by solid-phase extraction, liquid chromatography with fluorescence detection, and mass spectrometry. The bioconcentration factors obtained in the steady state were 17.2 ±1.2 L/kg for 2ØC10 LAS and 386.5 ± 31.5 L/kg for 2ØC12 LAS. A kinetic study also was performed with 2ØC12 LAS, and the rate constants of uptake and elimination were K1 = 177.04 L/kg d and K2 = 0.92/d, respectively. The formation of the intermediate degradation products was monitored during the 2ØC10 LAS experiment, thus allowing, to our knowledge for the first time, the identification and quantification of SPCs from 5ØC6 to 9ØC10 in marine organisms and in the depuration water as a result of biotransformation by the organisms, diffusive elimination, and excretion. The elimination percentage of the surfactants is both time- and concentration-dependent, and this suggests the existence of a concentration limit for the surfactant in the fish below which the elimination processes are slow. Overall, LAS are not persistent bioaccumulative compounds at environmental exposure levels.
Biochemical ripening of dredged sediments. Part 2. Degradation of polycyclic aromatic hydrocarbons and total petroleum hydrocarbons in slurried and consolidated sediments
Authors: Vermeulen Johan , van Gool Martine P. M. , Mentink Geert H. , Joziasse Jan , Bruning Harry , Rulkens Wim H. , Grotenhuis J. T. C. (Tim) 
Published: November 2007

AbstractRipening of polycyclic aromatic hydrocarbons (PAH) and total petroleum hydrocarbons (TPH) polluted dredged sediment can be considered as a bioremediation technique. Aerobic biodegradation of PAH and TPH was studied in five previously anaerobicslurried sediments during a 350-d laboratory incubation experiment. In addition, oxygen penetration and degradation of PAH and TPH were studied in three consolidated (physically ripened) sediments. All experiments were conducted in the laboratory at 30°C. A double exponential decay model could adequately describe PAH and TPH degradation kinetics in the slurried sediments. First-order degradation rate constants for the rapidly degradable fractions (12–58%) were approximately 0.13 and 0.058 d−1 for PAH and TPH, respectively, whereas the rate constants for the slowly degradable fractions were approximately 0.36 × 10−3 (PAH) and 0.66 × 10−3 d−1 (TPH). Rate constants for the rapidly and slowly degrading fractions have the same order of magnitude as the mineralization rate constants of the rapidly and slowly mineralizing organic matter (OM) fractions in the sediments. Oxygen uptake by degradation of PAH and TPH was negligible compared to the oxygen uptake by sulfur oxidation and OM mineralization. In consolidated sediments, PAH and TPH degradation was limited to the oxygenated part. Amounts of PAH and TPH that degraded in the oxygenated parts of the consolidated sediments during 21 d of incubation were similar to the amounts that degraded during 21 d in the slurried sediments.
A quantitative real-time polymerase chain reaction method for the analysis of vitellogenin transcripts in model and nonmodel fish species
Authors: Biales Adam D. , Bencic David C. , Lazorchak Jim L. , Lattier David L. 
Published: November 2007

Abstract
The measurement of vitellogenin (vtg) gene transcription has been shown to be a reliable indicator of exposure to estrogenic compounds. Unfortunately, the relatively poor molecular characterization of North American fish species has hindered its application to a larger number of ecologically important species. The current research aimed to demonstrate specific amplification of vtg gene transcripts in three model (zebrafish, rainbow trout, and medaka) and six nonmodel (emerald shiner, pearl dace, smallmouth bass, creek chub, white sucker, and golden redhorse) fish species. Quantitative polymerase chain reaction (QPCR) primers for model species were designed from publicly available vtg sequences. Successful amplification of vtg was demonstrated in fish exposed to 17α-ethinylestradiol (EE2) for all model species. Vitellogenin primers for selected nonmodel species were designed from published sequences of closely related species. Multiple primers were developed targeting different regions of the vtg gene. The successful amplification of vtg was confirmed through size and sequence analysis for all nonmodel species with the exception of the white sucker, in which amplifications failed. Furthermore, QPCR primers and conditions were quantitative over five orders of magnitude in at least one species (pearl dace) exposed to 5 ng/L of EE2 for 24 h. The selected species are found in a wide array of ecological habitats that span the United States. Inclusion of vtg transcriptional analysis for wild, ecologically relevant fish in monitoring studies may aid in understanding the extent of estrogenic exposure in aquatic ecosystems across the United States.
Hepatic biomarker responses to organic contaminants in feral chub (Leuciscus cephalus)—laboratory characterization and field study in the Sava River, Croatia
Authors: Krča Sanja , Žaja Roko , Čalić Violeta , Terzić Senka , Grubešić Miloš Saša , Ahel Marijan , Smital Tvrtko 
Published: November 2007

AbstractAs a widely spread cyprinid fish species, the European chub (Leuciscus cephalus) has been used extensively in bio-monitoring programs. However, no laboratory dose-response and/or time course studies related to applied biomarkers have been reported on chub yet. In order to address this issue, specimens of juvenile chub caught in September 2005 in the Sava River, Croatia, were laboratory exposed to various (0.25–50 mg/kg) doses of either model polycyclic aromatic hydrocarbons (PAH) premutagen benzo[a]pyrene (BaP), or β-naphthoflavone (β-NF), a well-known model cytochrome 1A (CYP1A) inducer, for 3 (BaP) or 5 d (β-NF). The responses of several hepatic biomarkers were determined in the exposed fish: The hepatic 7-ethoxyresorufin-O-deethylase activity, CYP1A content, glutathione S-transferase (GST) activity, liver bioactivation potential, and the amount of hydroxylated polycyclic aromatic hydrocarbon bile metabolites determined by the fixed wavelength fluorescence and the high-performance liquid chromatography technique. The relevance of determined biomarker responses has been analyzed further and crosscorrelated with the same set of biomarkers, as well as with tissue concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls, determined in chub specimens collected in September 2005 at five different polluted locations along the Sava River. The species-specific upper and lower limits in responses of studied biomarkers were determined and the obtained ranges successfully evaluated in real field situation. With the exception of the GST activity, all other biomarkers determined in chub proved to be valuable indicators of environmental pollution. Finally, the results of the present study demonstrated that the same strategy of laboratory characterization in combination with field evaluation should be used regularly in the selection of optimal biomarkers and indicator species.
Polycyclic aromatic hydrocarbon exposure in Steller's eiders (Polysticta stelleri) and Harlequin ducks (Histronicus histronicus) in the eastern Aleutian Islands, Alaska, USA
Authors: Miles A. Keith , Flint Paul L. , Trust Kimberley A. , Ricca Mark A. , Spring Sarah E. , Arrieta Daniel E. , Hollmen Tuula , Wilson Barry W. 
Published: November 2007

AbstractSeaducks may be affected by harmful levels of polycyclic aromatic hydrocarbons (PAHs) at seaports near the Arctic. As an indicator of exposure to PAHs, we measured hepatic enzyme 7-ethoxyresorufin-O-deethylase activity (EROD) to determine cytochrome P4501A induction in Steller's eiders (Polysticta stelleri) and Harlequin ducks (Histronicus histronicus) from Unalaska, Popof, and Unga Islands (AK, USA) in 2002 and 2003. We measured PAHs and organic contaminants in seaduck prey samples and polychlorinated biphenyl congeners in seaduck blood plasma to determine any relationship to EROD. Using Akaike's information criterion, species and site differences best explained EROD patterns: Activity was higher in Harlequin ducks than in Steller's eiders and higher at industrial than at nonindustrial sites. Site-specific concentrations of PAHs in blue mussels ([Mytilus trossilus] seaduck prey; PAH concentrations higher at Dutch Harbor, Unalaska, than at other sites) also was important in defining EROD patterns. Organochlorine compounds rarely were detected in prey samples. No relationship was found between polychlorinated biphenyl congeners in avian blood and EROD, which further supported inferences derived from Akaike's information criterion. Congeners were highest in seaducks from a nonindustrial or reference site, contrary to PAH patterns. To assist in interpreting the field study, 15 captive Steller's eiders were dosed with a PAH known to induce cytochrome P4501A. Dosed, captive Steller's eiders had definitive induction, but results indicated that wild Steller's eiders were exposed to PAHs or other inducing compounds at levels greater than those used in laboratory studies. Concentrations of PAHs in blue mussels at or near Dutch Harbor (∼1,180–5,980 ng/g) approached those found at highly contaminated sites (∼4,100–7,500 ng/g).
Influence of in-stream diel concentration cycles of dissolved trace metals on acute toxicity to one-year-old cutthroat trout (Oncorhynchus clarki lewisi)
Authors: Nimick David A. , Harper David D. , Farag Aïda M. , Cleasby Thomas E. , MacConnell Elizabeth , Skaar Don 
Published: November 2007

AbstractExtrapolating results of laboratory bioassays to streams is difficult, because conditions such as temperature and dissolved metal concentrations can change substantially on diel time scales. Field bioassays conducted for 96 h in two mining-affected streams compared the survival of hatchery-raised, metal-näive westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to dissolved (0.1-μm filtration) metal concentrations that either exhibited the diel variation observed in streams or were controlled at a constant value. Cadmium and Zn concentrations in these streams increased each night by as much as 61 and 125%, respectively, and decreased a corresponding amount the next day, whereas Cu did not display a diel concentration cycle. In High Ore Creek (40 km south of Helena, MT, USA), survival (33%) after exposure to natural diel-fluctuating Zn concentrations (range, 214–634 μg/L; mean, 428 μg/L) was significantly (p = 0.008) higher than survival (14%) after exposure to a controlled, constant Zn concentration (422 μg/L). Similarly, in Dry Fork Belt Creek (70 km southeast of Great Falls, MT, USA), survival (75%) after exposure to diel-fluctuating Zn concentrations (range, 266–522 μg/L; mean, 399 μg/L) was significantly (p = 0.022) higher than survival (50%) in the constant-concentration treatment (392 μg/L). Survival likely was greater in these diel treatments, both because the periods of lower metal concentrations provided some relief for the fish and because toxicity during periods of higher metal concentrations was lessened by the simultaneous occurrence each night of lower water temperatures, which reduce the rate of metal uptake. Based on the present study, current water-quality criteria appear to be protective for streams with diel concentration cycles of Zn (and, perhaps, Cd) for the hydrologic conditions tested.
Egg incubation position affects toxicity of air cell administered polychlorinated biphenyl 126 (3,3′,4,4′,5-pentachlorobiphenyl) in chicken (Gallus gallus) embryos
Authors: McKernan Moira A. , Rattner Barnett A. , Hale Robert C. , Ottinger Mary Ann 
Published: November 2007

AbstractThe avian egg is used extensively for chemical screening and determining the relative sensitivity of species to environmental contaminants (e.g., metals, pesticides, polyhalogenated compounds). The effect of egg incubation position on embryonic survival, pipping, and hatching success was examined following air cell administration of polychlorinated biphenyl (PCB) congener 126 (3,3′,4,4′,5-pentachlorobiphenyl [PCB 126]; 500–2,000 pg/g egg) on day 4 of development in fertile chicken (Gallus gallus) eggs. Depending on dose, toxicity was found to be up to nine times greater in vertically versus horizontally incubated eggs. This may be due to enhanced embryonic exposure to the injection bolus in vertically incubated eggs compared to more gradual uptake in horizontally incubated eggs. Following air cell administration of PCB 126, horizontal incubation of eggs may more closely approximate uptake and toxicity that has been observed with naturally incorporated contaminants. These data have implications for chemical screening and use of laboratory data for ecological risk assessments.
Lead toxicity in alfalfa plants exposed to phytohormones and ethylenediaminetetraacetic acid monitored by peroxidase, catalase, and amylase activities
Authors: López Martha L. , Peralta-Videa Jose R. , Castillo-Michel Hiram , Martinez-Martinez Alejandro , Duarte-Gardea Maria , Gardea-Torresdey Jorge L. 
Published: November 2007

Abstract
This manuscript describes the toxicity of lead in alfalfa plants treated with ethylenediaminetetraacetic acid (EDTA) and the phytohormones indole-3-acetic-acid (IAA), gibberellic acid (GA), and kinetin (KN), on catalase (CAT), ascorbate peroxidase (APOX), and total amylase activity (TAA). In all cases Pb was used at 40 mg/L; EDTA at 0.2 mM (equimolar to Pb); and IAA, GA, and KN at 1, 10, and 100 μM, respectively. An experiment containing Pb at 40 mg/L, 0.2 mM EDTA, and IAA and KN at 100 μM each was performed to determine changes in TAA. A control (plain nutrient solution) also was used for comparison. In all cases the treatments were performed in triplicate. Standard procedures were followed to determine the activity of the respective enzymes. After 10 d of exposure to the treatments, the leaves were harvested, homogenized, and centrifuged, and the supernatants were analyzed for CAT, APOX, and TAA. All determinations were performed in triplicate. The results demonstrated that CAT was reduced significantly (p &lt; 0.05) by all treatments containing Pb, IAA, and GA at 10 and 100 μM. However, only the treatments Pb/EDTA/KN at 1, 10, and 100 μM reduced the APOX. The TAA in leaves of alfalfa plants was increased significantly (p &lt; 0.05) by all treatments. Overall, the results suggest that the CAT tests showed no lead toxicity to the alfalfa seedlings. However IAA at 10 and 100 μM revealed toxicity to the CAT enzyme. In addition, the APOX tests exhibited no toxicity to the peroxidase enzyme with the exception of Pb/EDTA/KN treatments. Finally, the TAA tests showed high Pb/EDTA/phytohormone toxicity to the amylase enzyme in alfalfa seedlings.
Patient Out-of-Pocket Costs for Biologic Drugs After Biosimilar Competition
Authors: Feng Kimberly , Russo Massimiliano , Maini Luca , Kesselheim Aaron S. , Rome Benjamin N. 
Published: March 2024

ImportanceBiologic drugs account for a growing share of US pharmaceutical spending. Competition from follow-on biosimilar products (subsequent versions that have no clinically meaningful differences from the original biologic) has led to modest reductions in US health care spending, but these savings may not translate to lower out-of-pocket (OOP) costs for patients.ObjectiveTo investigate whether biosimilar competition is associated with lower OOP spending for patients using biologics.Design, Setting, and ParticipantsThis cohort study used a national commercial claims database (Optum Clinformatics Data Mart) to identify outpatient claims for 1 of 7 clinician-administered biologics (filgrastim, infliximab, pegfilgrastim, epoetin alfa, bevacizumab, rituximab, and trastuzumab) from January 2009 through March 2022. Claims by commercially insured patients younger than 65 years were included.ExposureYear relative to first biosimilar availability and use of original or biosimilar version.Main Outcomes and MeasuresPatients’ annual OOP spending on biologics for each calendar year was determined, and OOP spending per claim between reference biologic and biosimilar versions was compared. Two-part regression models assessed for differences in OOP spending, adjusting for patient and clinical characteristics (age, sex, US Census region, health plan type, diagnosis, and place of service) and year relative to initial biosimilar entry.ResultsOver 1.7 million claims from 190 364 individuals (median [IQR] age, 53 [42-59] years; 58.3% females) who used at least 1 of the 7 biologics between 2009 and 2022 were included in the analysis. Over 251 566 patient-years of observation, annual OOP costs increased before and after biosimilar availability. Two years after the start of biosimilar competition, the adjusted odds ratio of nonzero annual OOP spending was 1.08 (95% CI, 1.04-1.12; P &amp;lt; .001) and average nonzero annual spending was 12% higher (95% CI, 10%-14%; P &amp;lt; .001) compared with the year before biosimilar competition. After biosimilars became available, claims for biosimilars were more likely than reference biologics to have nonzero OOP costs (adjusted odds ratio, 1.13 [95% CI, 1.11-1.16]; P &amp;lt; .001) but had 8% lower mean nonzero OOP costs (adjusted mean ratio, 0.92 [95% CI, 0.90-0.93; P &amp;lt; .001). Findings varied by drug.Conclusions and RelevanceFindings of this cohort study suggest that biosimilar competition was not consistently associated with lower OOP costs for commercially insured outpatients, highlighting the need for targeted policy interventions to ensure that the savings generated from biosimilar competition translate into increased affordability for patients who need biologics.
Outcomes After Initiation of Medications for Alcohol Use Disorder at Hospital Discharge
Authors: Bernstein Eden Y. , Baggett Travis P. , Trivedi Shrunjal , Herzig Shoshana J. , Anderson Timothy S. 
Published: March 2024

ImportanceUS Food and Drug Administration–approved medications for alcohol use disorder (MAUD) are significantly underused. Hospitalizations may provide an unmet opportunity to initiate MAUD, but few studies have examined clinical outcomes of patients who initiate these medications at hospital discharge.ObjectiveTo investigate the association between discharge MAUD initiation and 30-day posthospitalization outcomes.Design, Setting, and ParticipantsThis cohort study was conducted among patients with Medicare Part D who had alcohol-related hospitalizations in 2016. Data were analyzed from October 2022 to December 2023.ExposuresDischarge MAUD initiation was defined as oral naltrexone, acamprosate, or disulfiram pharmacy fills within 2 days of discharge.Main outcomesThe primary outcome was a composite of all-cause mortality or return to hospital (emergency department visits and hospital readmissions) within 30 days of discharge. Secondary outcomes included these components separately, return to hospital for alcohol-related diagnoses, and primary care or mental health follow-up within 30 days of discharge. Propensity score 3:1 matching and modified Poisson regressions were used to compare outcomes between patients who received and did not receive discharge MAUD.ResultsThere were 6794 unique individuals representing 9834 alcohol-related hospitalizations (median [IQR] age, 54 [46-62] years; 3205 hospitalizations among females [32.6%]; 1754 hospitalizations among Black [17.8%], 712 hospitalizations among Hispanic [7.2%], and 7060 hospitalizations among White [71.8%] patients). Of these, 192 hospitalizations (2.0%) involved discharge MAUD initiation. After propensity matching, discharge MAUD initiation was associated with a 42% decreased incidence of the primary outcome (incident rate ratio, 0.58 [95% CI, 0.45 to 0.76]; absolute risk difference, −0.18 [95% CI, −0.26 to −0.11]). These findings were consistent among secondary outcomes (eg, incident rate ratio for all-cause return to hospital, 0.56 [95% CI, 0.43 to 0.73]) except for mortality, which was rare in both groups (incident rate ratio, 3.00 [95% CI, 0.42 to 21.22]). Discharge MAUD initiation was associated with a 51% decreased incidence of alcohol-related return to hospital (incident rate ratio, 0.49 [95% CI, 0.34 to 0.71]; absolute risk difference, −0.15 [95% CI, −0.22 to −0.09]).Conclusion and relevanceIn this cohort study, discharge initiation of MAUD after alcohol-related hospitalization was associated with a large absolute reduction in return to hospital within 30 days. These findings support efforts to increase uptake of MAUD initiation at hospital discharge.