bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetics and pharmacodynamics of controlled release insulin loaded PLGA microcapsules using dry powder inhaler in diabetic rats
Authors: Hamishehkar Hamed , Emami Jaber , Najafabadi Abdolhossien Rouholamini , Gilani Kambiz , Minaiyan Mohsen , Hassanzadeh Kambiz , Mahdavi Hamid , Koohsoltani Maryam , Nokhodchi Ali 
Published: March 2010

AbstractThe pulmonary route is an alternative route of administration for the systemic delivery of peptide and proteins with short‐half lives. A long‐acting formulation of insulin was prepared by encapsulation of protein into respirable, biodegradable microcapsules prepared by an oil in oil emulsification/solvent evaporation method. Insulin‐loaded PLGA microcapsules prepared as a dry powder inhaler formulation were administered via the pulmonary route to diabetic rats and serum insulin and glucose concentrations were monitored. Control treatments consisted of respirable spray‐dried insulin (RSDI) powder administered by intratracheal insufflation, insulin‐loaded PLGA microcapsules and NPH (long‐acting) insulin administered by subcutaneous (SC) administration. Pharmacokinetic analysis demonstrated that insulin administered in PLGA microcapsules illustrated a sustained release profile which resulted in a longer mean residence time, 4 and 5 fold longer than those after pulmonary administration of RSDI and SC injection of NPH insulin, respectively. Accordingly, the hypoglycemic profile followed a stable and sustained pattern which remained constant between 10 and 48 h. Results of the in vitro experiments were in good agreement with those of in vivo studies. Bronchoalveolar lavage fluid analysis indicated that microcapsules administration did not increase the activities of lactate dehydrogenase and total protein. However, histological examination of the lung tissue indicated a minor but detectable effect on the normal physiology of the rat lung. These findings suggest that the encapsulation of peptides and proteins into PLGA microcapsules technique could be a promising controlled delivery system for pulmonary administration. Copyright © 2010 John Wiley & Sons, Ltd.
Proton leak modulation in testicular mitochondria affects reactive oxygen species production and lipid peroxidation
Authors: Rodrigues Ana Sofia , Lacerda Beatriz , Moreno António J. M. , Ramalho‐Santos João 
Published: March 2010

AbstractMitochondrial proton leak can account for almost 20% of oxygen consumption and it is generally accepted that this process contributes to basal metabolism. In order to clarify the role of basal proton leak in testicular mitochondria, we performed a comparative study with kidney and liver mitochondrial fractions. Proton leak stimulated by linoleic acid and inhibited by guanosine diphosphate (GDP) was detected, in a manner that was correlated with protein levels for uncoupling protein 2 (UCP2) in the three fractions. Modulation of proton leak had an effect on reactive oxygen species production as well as on lipid peroxidation, and this effect was also tissue‐dependent. However, a possible role for the adenine nucleotide transporter (ANT) in testicular mitochondria proton leak could not be excluded. The modulation of proton leak appears as a possible and attractive target to control oxidative stress with implications for male gametogenesis. Copyright © 2010 John Wiley & Sons, Ltd.
How credible are mining corporations' sustainability reports? a critical analysis of external assurance under the requirements of the international council on mining and metals
Authors: Fonseca Alberto 
Published: March 2010

AbstractMember companies of the International Council on Mining and Metals (ICMM) have committed to publish externally assured sustainability reports. This paper evaluates the quality of assurance provided to those companies by analyzing the extent to which a sample of their assurance statements met minimum recommended contents. It also seeks to understand the implications of the recently launched ICMM Assurance Procedure. Nine out of the sixteen companies hired assurance in the period analyzed. Their statements mirrored several quality problems highlighted in previous studies. The extensive scope limitations and diversity of verification criteria employed by assurors indicate that mining companies had significant control over the practice. The Assurance Procedure might bring more consistency and breadth to the verification process. The extent to which it will contribute to increased trust in reported information will depend on several factors, including how assurors may interpret the procedure's requirements. Directions for further research are discussed. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Lifetime evaluation in energy‐efficient rectangularad hocwireless networks
Authors: Feng Wei , Elmirghani Jaafar M. H. 
Published: March 2010

AbstractAd hocwireless network nodes are typically battery‐powered, therefore energy limit is one of the critical constraints ofad hocwireless networks' development. This paper evaluates the network lifetime of a rectangular network model that achieves energy efficiency by optimizing the node radio range based on the geographical adaptive fidelity (GAF) topology management protocol (Proceedings of ACMMobil'01, July 2001; 70–84). We derive the optimal transmission range of nodes and analyze both static and dynamic traffic scenarios in both equal‐grid and adjustable‐grid rectangular GAF models, where the results show that the adjustable‐grid model saves 78.1% energy in comparison with the minimum energy consumption of equal‐grid model. The impact of node density on both equal‐grid and adjustable‐grid models is investigated to achieve grid‐lifetime balance among all grids to optimize the entire network lifetime. The lifetime estimation results show that without node density control the adjustable‐grid model prolongs the entire network lifetime by a factor of 4.2 compared with the equal‐grid model. Furthermore, the adjustable‐grid model with node density control is able to prolong the entire network lifetime by a factor of 6 compared with the equal‐grid model. Copyright © 2010 John Wiley & Sons, Ltd.
17α-ethinylestradiol induces an imbalance between apoptosis and cell proliferation to sex steroid disruption in a testis culture of gudgeon,Gobio gobio
Authors: Nadzialek Stéphanie , Kestemont Patrick 
Published: March 2010

AbstractThe aim of this study was to investigate the effect of the most potent xenoestrogen currently found in the environment, ethinylestradiol (EE2), on some physiological events occurring during early spermatogenesis of gudgeon (Gobio gobio), a common European fish species. Physiological pathways studies were apoptosis, cell proliferation, and steroidogenesis on sex steroids (testosterone [T], 11-ketotestosterone [11-KT], and 17β-estradiol [E2]). Testis pieces were cultured in vitro during 21 d at 10−4, 10−3, 10−2, 10−1, 1 and 10 µg/L of EE2 as well as in positive (10−1 µg/L of E2) and ethanol control medium. Apoptosis and cell proliferation displayed opposite responses related to the EE2 concentration. When apoptosis inhibition was observed, cell proliferation was induced at 10−2 and 10−1 µg/L of EE2 as well as in the positive control. In contrast, a massive cell death was detected for high EE2 concentrations (1 and 10 µg/L). Steroidogenesis was also disrupted in a dose-related manner. 11-Ketotestosterone was depressed at 10−2 and 10−1 µg/L of EE2 whereas E2 was detectable in the medium only at 10−3, 10−2, and 10−1 µg/L of EE2. High concentrations of T were detected in the medium at 10−3, 10−2, and 10−1 µg/L of EE2 but depressed at 1 and 10 µg/L of EE2. In conclusion, intermediate EE2 concentrations (10−2 and 10−1 µg/L) used in this experimental design have obviously disrupted early spermatogenesis, leading to an imbalance between cell death and cell proliferation in a sex steroid environment toward E2. The results of the present study could be the basis conditions for oocyte development within the testis of a common teleost fish under xenoestrogen exposure. Environ. Toxicol. Chem. 2010;29:881–886. © 2009 SETAC
Influences of soil properties and leaching on copper toxicity to barley root elongation
Authors: Li Bo , Ma Yibing , Mclaughlin Mike J. , Kirby Jason K. , Cozens Gill , Liu Jifang 
Published: March 2010

Abstract
The relationships developed between soil properties and phytotoxicity threshold values for copper require validation in a wide range of soils with different properties and climate characteristics before they can be applied for regulatory purposes in countries throughout the world. Seventeen soils, which are representative of the major soil types and properties in China, were spiked with Cu chloride. A subset of the Cu-spiked soils was leached with artificial rain water to compare toxicity with that in unleached soils. Barley root elongation tests were performed under controlled environmental conditions. The concentrations of added Cu causing a 50% inhibitory effect (EC50) ranged from 67 to 1,129 mg/kg in unleached soils and from 88 to 1,255 mg/kg in leached soil. Compared with the unleached toxicity thresholds, the leached EC10 (10% inhibition) and EC50 were higher by an average of 1.43- and 1.15-fold, respectively. Soil leaching significantly (p ≤ 0.05) decreased the toxicity of Cu in approximately 35% of the soils. In this study, no single soil property was found to explain over 35% of the variance in (log transformed) EC50. However, stepwise multiple regressions using soil pH, organic carbon (OC) content, and effective cation exchange capacity (eCEC) were found to explain over 80% of the variance in Cu toxicity across soils. The model developed for Chinese soils based on these factors was found to predict significantly (r2, 0.90) the phytotoxicity of Cu in European soils. These quantitative relationships between Cu toxicity and soil properties are helpful for developing soil-specific guidance on Cu toxicity thresholds. Environ. Toxicol. Chem. 2010;29:835–842. © 2009 SETAC
Toxicity and biotransformation of uncoated and coated nickel hydroxide nanoparticles on mesquite plants
Authors: Parsons Jason G. , Lopez Martha L. , Gonzalez Christina M. , Peralta-Videa Jose R. , Gardea-Torresdey Jorge L. 
Published: March 2010

Abstract
Nanomaterials are of particular interest in environmental chemistry due to their unknown toxicity to living organisms. Reports indicate that nanoparticles (NPs) affect seed germination, but the uptake and biotransformation of metal nanoparticles is not well understood. The present study investigated the toxicity and biotransformation of Ni(OH)2 NPs by mesquite plants (Prosopis sp.). Three sets of plants were treated for four weeks with 0.01, 0.05, or 0.10 g of either uncoated or sodium citrate coated NPs before and after synthesis. Nickel concentrations in plants were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and the form and oxidation state of Ni was determined using X-ray absorption spectroscopy (XAS). Results showed that uncoated NPs had an average size of 8.7 nm, whereas coated NPs before and after synthesis had an average of 2.5 and 0.9 nm, respectively. The ICP-OES results showed that plants treated with 0.10 g of uncoated and coated NPs before and after synthesis had 803, 764, and 400 mg Ni kg dry weight, in the leaves, respectively. The XAS analyses showed Ni NPs in roots and shoots of plants treated with uncoated NPs, whereas leaves showed a Ni(II)-organic acid type complex. However, plants treated with coated NPs before or after synthesis showed Ni NPs only in roots and a Ni(II)-organic acid complex in shoots and leaves. Results also showed that none of the treatments reduced plant size or chlorophyll production. To the authors' knowledge, this is the first time that the biotransformation of nanoparticles by a plant system is reported. Environ. Toxicol. Chem. 2010;29:1146–1154. © 2010 SETAC
Multimedia modeling of human exposure to chemical substances: The roles of food web biomagnification and biotransformation
Authors: Arnot Jon A. , Mackay Don , Parkerton Thomas F. , Zaleski Rosemary T. , Warren Christopher S. 
Published: March 2010

Abstract
The Risk Assessment IDentification And Ranking (RAIDAR) model is refined to calculate relative human exposures as expressed by total intake, intake fraction (iF), and total body burden (TBB) metrics. The RAIDAR model is applied to three persistent organic pollutants (POPs) and six petrochemicals using four mode-of-entry emission scenarios to evaluate the effect of metabolic biotransformation estimates on human exposure calculations. When biotransformation rates are assumed to be negligible, daily intake and iFs for the nine substances ranged over six orders of magnitude and TBBs ranged over 10 orders of magnitude. Including biotransformation estimates for fish, birds, and mammals reduced substance-specific daily intake and iF by up to 4.5 orders of magnitude and TBB by more than eight orders of magnitude. The RAIDAR iF calculations are compared to the European Union System for the Evaluation of Substances (EUSES) model iF calculations and differences are discussed, especially the treatment of food web bioaccumulation. Model selection and application assumptions result in different rankings of human exposure potential. These results suggest a need to critically consider model selection and to include reliable biotransformation rate estimates when assessing relative human exposure and ranking substances for priority setting. Recommendations for further model evaluations and revisions are discussed. Environ. Toxicol. Chem. 2010;29:45–55. © 2009 SETAC
Toxicity of the herbicides bromacil and simazine to the aquatic macrophyte, Vallisneria americana Michx
Authors: Wilson P. Chris , Wilson Sandra B. 
Published: March 2010

Abstract
Vallisneria americana Michx. (tapegrass) is an ecologically important submersed, vascular aquatic plant that provides food and shelter for many aquatic and waterfowl species. This plant often occurs close to land areas where herbicides are used. Nontarget exposure of these plants to herbicides may compromise ecological structure and function. The objective of the present study was to evaluate the suitability of several endpoint measurements for determining no-observable-adverse effect concentrations (NOAECs), lowest-observable-adverse effect concentrations (LOAECs), and median effective concentration values (EC50s) for tapegrass exposed to the herbicides bromacil (0–0.092 mg/L) and simazine (0–0.592 mg/L) following a 13-d single-pulse exposure and 15-d (bromacil) or 14-d (simazine) postexposure periods. The NOAEC/LOAEC/EC50 for fresh weight gains, new leaf production, and total leaf growth after 13-d exposure to bromacil were 0.020/0.036/0.032, 0.036/0.054/0.036, and 0.036/0.054/0.043 mg/L, respectively. The same respective NOAEC/LOAEC/EC50s for simazine were &lt;0.058/0.058/0.067, 0.229/0.344/0.154, and 0.058/0.116/0.081 mg/L. Reductions in quantity and fresh weight of daughter plants produced and stolon fresh weights occurred at bromacil concentrations ≥0.077, 0.020, and 0.036 mg/L, respectively; and simazine concentrations ≥0.344, &gt;0.592, and ≥0.116 mg/L, respectively. Neither herbicide affected leaf greenness, total chlorophyll concentrations, or carbohydrate allocation. Although toxicity was shown for many endpoints, most EC50 values were greater than aquatic life benchmark values for algae used by the U.S. Environmental Protection Agency (U.S. EPA), but less than for aquatic plants, indicating that V. americana would likely be protected by use of the algal benchmark criteria. Environ. Toxicol. Chem. 2010;29:201–211. © 2009 SETAC
An evaluation of mercury concentrations in three brands of canned tuna
Authors: Gerstenberger Shawn L. , Martinson Adam , Kramer Joanna L. 
Published: March 2010

Abstract
There is widespread concern over the presence of Hg in fish consumed by humans. While studies have been focused on determining the Hg concentration in sport fish and some commercial fish, little attention has been directed to canned tuna; it is widely held that concentrations are low. In the present study, the amount of Hg present in canned tuna purchased in Las Vegas, Nevada, USA, was examined, and the brand, temporal variation, type, and packaging medium impacts on Hg concentrations in tuna were explored. A significant (p &lt; 0.001) brand difference was noted: Brand 3 contained higher Hg concentrations ( standard deviation (SD) (0.777 ± 0.320 ppm) than Brands 1 (0.541 ± 0.114 ppm) and 2 (0.550 ± 0.199 ppm). Chunk white tuna (0.619 ± 0.212 ppm) and solid white tuna (0.576 ± 0.178 ppm) were both significantly (p &lt; 0.001) higher in mean Hg than chunk light tuna (0.137 ± 0.063 ppm). No significant temporal variation was noted, and packaging had no significant effect on Hg concentration. In total, 55% of all tuna examined was above the U.S. Environmental Protection Agency's (U.S. EPA) safety level for human consumption (0.5 ppm), and 5% of the tuna exceeded the action level established by the U.S. Food and Drug Administration (U.S. FDA) (1.0 ppm). These results indicate that stricter regulation of the canned tuna industry is necessary to ensure the safety of sensitive populations such as pregnant women, infants, and children. According to the U.S. EPA reference dose of 0.1 µg/kg body weight per day and a mean Hg value of 0.619 ppm, a 25-kg child may consume a meal (75 g) of canned chunk white tuna only once every 18.6 d. Continued monitoring of the industry and efforts to reduce Hg concentrations in canned tuna are recommended. Environ. Toxicol. Chem. 2010;29:237–242. © 2009 SETAC
Arsenic in Lake Lansing, michigan
Authors: Batterson Ted R. , McNabb Clarence D. 
Published: March 2010

Abstract
Lake Lansing was treated with sodium arsenite for macrophyte control in 1957. Two 2.5-m cores from deep portions of the basin showed the historical consequence of this treatment. Maxima of 330–340 μg As g−1 dry weight occurred at a depth interval of 0.15–0.30 m; background was 17–20 ppm As. An arsenic mass balance budget for the lake for June 1978 to June 1979 showed it lost more arsenic than it received. Internal loading of the water from the sediments was occurring; &gt; 85% of the area of surficial sediments had concentrations two to six times background. From laboratory experiments, we hypothesize Fe3+ controls arsenic concentration over aerobic sediments; As(III) increases in anoxic water with conversion of Fe3+ to Fe2+ and As(V) to As(III) at the sediment surface. As(III) in water diminishes during prolonged anoxia by reaction with S2−. As(III) and Fe2+ are oxidized upon aeration of anoxic water, and As(V) is taken out of solution with ferric iron in a manner similar to phosphate. Arsenic concentrations observed in the lake over an annual cycle fit these expectations.
Comparative toxicology of mirex, photomirex and chlordecone after oral administration to the mouse
Authors: Fujimori K. , Ho I. K. , Mehendale H. M. , Villeneuve D.C. 
Published: March 2010

AbstractThe toxicities of chlordecone (CD), mirex (M) and photomirex (PM) were compared in the male mouse after daily oral administration of 10 mg/kg in corn oil vehicle (10 ml/kg). Mortality occurred starting day 10 with M, and day 16 with PM and CD, and LT50 values were 132, 265 and 254 mg/kg, respectively. However the LT50 values of M, PM or CD were not different (range, 100–125 mg/kg) when animals were intubated with the compounds daily at 25 or 50 mg/kg. Food and water consumption and body weight were decreased after M, but PM and CD increased these parameters. Other symptoms of toxicity included severe diarrhea with M, whereas a moderate diarrhea occurred with PM and little or no diarrhea with CD. The effects of M, PM or CD on the hepatic microsomal mixed function oxidase system were compared 4 d after the administration of 10 mg/kg/d of these compounds. M and PM were equipotent, whereas CD was found to be approximately half as effective in inducing cytochrome P-450 and associated enzyme activities. CD and M caused a decrease in blood glucose levels due to enhanced oxidation, since liver glycogen levels were also reduced. CD-induced tremors could not be prevented by restoring the blood glucose level. CD levels in liver, muscle, whole brain and plasma were several-fold higher than for either M or PM. These results suggest that although structurally similar, these three analogs differ significantly in their biological effects.
The effects of a chronic mercury exposure on survival, reproduction and population dynamics of Mysidopsis Bahia
Authors: Gentile J. H. , Gentile S. M. , Hoffman G. , Heltshe J. F. , Hairston N. 
Published: March 2010

Abstract
The epibenthic mysid Mysidopsis bahia was chronically exposed throughout its entire life cycle to inorganic mercury. The experimental design permitted the precise measurements of survival rates; individual and population growth rates; and sublethal reproductive responses, including time to sexual maturation and first brood release, egg development time, brood size and frequency of reproduction. Mercury was acutely toxic (96-h LC50) to juveniles at 3.5 μg L−1, chronically toxic (35-d LC50) at 1.8 μg L−1 and differentially toxic to males and females (α = 0.05). Male and female mortality rates were 35 and 18%, respectively, from sexual maturation (day 14) through termination of the assay (day 35). Reproductive effects included delays in sexual maturation and brood release at 1.6 μg L−1, a doubling of brood development time at 2.5 μg L−1 and subsequent abortion and significant decreases in the total broods released (and therefore juveniles produced) at 1.6 μg L−1. Intrinsic rates of population increase (r), calculated from life-tables, decreased with increasing mercury concentration. The critical value (r = 0) for mercury occurs at 1.6 μg L−1, which corresponds well with the upper limit of the maximum acceptable toxicant concentration, the usual endpoint of life-cycle toxicity tests. The toxicity test system is a sensitive, precise model for studying lethal, sublethal and potential population consequences of pollution.
Relative sensitivity of Daphnia Magna, rainbow trout and fathead minnows to endosulfan
Authors: Nebeker Aaln V. , McCrady Joel K. , Mshar Roger , McAuliffe Chris K. 
Published: March 2010

Abstract
Flow-through and static tests were conducted with fathead minnows, rainbow trout and Daphnia magna to determine their relative sensitivities to measured concentrations of the insecticide endosulfan and to compare responses of fish in replicated static and flow-through exposure procedures. Fathead minnow 96-h static LC50 values were 1.3, 0.8 and 1.3 μg/L endosulfan. The 96-h LC50 values for fatheads in flow-through tests were 1.7 and 1.0 μg/L. Rainbow trout 96-h static LC50 values were 1.7 and 1.6 μg/L. The 96-h LC50 values for rainbows in flow-through tests were 0.3 and 0.4 μg/L. Acute 48-h static EC50 values for D. magna were 343 and 271 μg/L endosulfan. These results suggest that differences in species sensitivity can be as great as three orders of magnitude.