Consideration of exposure and species sensitivity of triclosan in the freshwater environment.

PubMed

Capdevielle, Marie; Van Egmond, Roger; Whelan, Mick; Versteeg, Donald; Hofmann-Kamensky, Matthias; Inauen, Josef; Cunningham, Virginia; Woltering, Daniel

2008-01-01

Triclosan (TCS) is a broad-spectrum antimicrobial used in consumer products including toothpaste and hand soap. After being used, TCS is washed or rinsed off and residuals that are not biodegraded or otherwise removed during wastewater treatment can enter the aquatic environment in wastewater effluents and sludges. The environmental exposure and toxicity of TCS has been the subject of various scientific and regulatory discussions in recent years. There have been a number of publications in the past 5 y reporting toxicity, fate and transport, and in-stream monitoring data as well as predictions from aquatic risk assessments. State-of-the-science probabilistic exposure models, including Geography-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) for European surface waters and Pharmaceutical Assessment and Transport Evalutation (PhATE) for US surface waters, have been used to predict in-stream concentrations (PECs). These models take into account spatial and temporal variability in river flows and wastewater emissions based on empirically derived estimates of chemical removal in wastewater treatment and in receiving waters. These model simulations (based on realistic use levels of TCS) have been validated with river monitoring data in areas known to be receiving high wastewater loads. The results suggest that 90th percentile (low flow) TCS concentrations are less than 200 ng/L for the Aire-Calder catchment in the United Kingdom and between 250 ng/L (with in-stream removal) and 850 ng/L (without in-stream removal) for a range of US surface waters. To better identify the aquatic risk of TCS, a species sensitivity distribution (SSD) was constructed based on chronic toxicity values, either no observed effect concentrations (NOECs) or various percentile adverse effect concentrations (EC10-25 values) for 14 aquatic species including fish, invertebrates, macrophytes, and algae. The SSD approach is believed to represent a more realistic threshold of effect than a predicted no effect concentration (PNEC) based on the data from the single most sensitive species tested. The log-logistic SSD was used to estimate a PNEC, based on an HC5,50 (the concentration estimated to affect the survival, reproduction and/or growth of 5% of species with a 50% confidence interval). The PNEC for TCS was 1,550 ng/L. Comparing the SSD-based PNEC with the PECs derived from GREATER and PhATE modeling to simulate in-river conditions in Europe and the United States, the PEC to PNEC ratios are less than unity suggesting risks to pelagic species are low even under the highest likely exposures which would occur immediately downstream of wastewater treatment plant (WWTP) discharge points. In-stream sorption, biodegradation, and photodegradation will further reduce pelagic exposures of TCS. Monitoring data in Europe and the United States corroborate the modeled PEC estimates and reductions in TCS concentrations with distance downstream of WWTP discharges. Environmental metabolites, bioaccumulation, biochemical responses including endocrine-related effects, and community level effects are far less well studied for this chemical but are addressed in the discussion. The aquatic risk assessment for TCS should be refined as additional information becomes available.

Predicted no-effect concentration (PNEC) and assessment of risk for the fungicide, triadimefon based on reproductive fitness of aquatic organisms.

PubMed

Liu, Na; Jin, Xiaowei; Zhou, Junying; Wang, Yeyao; Yang, Qi; Wu, Fengchang; Giesy, John P; Johnson, Andrew C

2018-05-21

Triadimefon, a broad-spectrum, systemic fungicide used to protect agricultural crops is popular in China. However, sub-lethal effects of triadimefon on aquatic organisms remained poorly understood, and its risks to aquatic organisms were unclear. In the current study, thresholds for chronic toxicity to five aquatic organisms were determined and a PNEC based on reproductive fitness of nine aquatic organisms was derived through use of a species sensitivity distribution (SSD). NOECs, based on reproduction or inhabitation of growth, for Oryzias latipes, Daphnia magna, Brachionus calyciflorus, Heterocypris incongruens and Soirodela polyrhiza were 5, 25, 80, 320 and 500 μg L -1 , respectively, and the final PNEC derived was 3.66 μg L -1 . A screening-level hazard assessment of surface water based on both measured environment concentrations (ND∼5.22 μg L -1 ) in 3 lakes, 2 reservoirs and 1 river and predicted environment concentrations (0.36-65 μg L -1 ) in a simulated river and pond, identified unacceptable hazard to aquatic organisms posed by triadimefon, with maximum hazard quotients (HQs) of 1.43 and 17.8, respectively. Potential deleterious effects and hazards or risks of exposure of aquatic organisms from current patterns of use of triadimefon in surface water if of concern. Since HQs were relatively small and the benefits large, it is suggested that mitigations be applied to allow use while minimizing potential for adverse effects on aquatic organisms. Copyright © 2018 Elsevier Ltd. All rights reserved.

Derivation of predicted no-effect concentration and ecological risk for atrazine better based on reproductive fitness.

PubMed

Zheng, Lei; Zhang, Yizhang; Yan, Zhenguang; Zhang, Juan; Li, Linlin; Zhu, Yan; Zhang, Yahui; Zheng, Xin; Wu, Jiangyue; Liu, Zhengtao

2017-08-01

Atrazine (ATZ) is an herbicide most commonly used in China and other regions of the world. It is reported toxic to aquatic organisms, and frequently occurs at relatively high concentrations. Currently, ATZ has been proved to affect reproduction of aquatic species at much lower levels. So it is controversial to perform ecological risk assessment using predicted no-effect concentrations (PENCs) derived from traditional endpoints, which fail to provide adequate protection to aquatic organisms. In this study, PNECs of ATZ were derived based on six endpoints of survival, growth, behavior, biochemistry, genetics and reproduction. The PNEC derived from reproductive lesion was 0.044μg ATZ L -1 , which was obviously lower than that derived from other endpoints. In addition, a tiered ecological risk assessment was conducted in the Taizi River based on six PNECs derived from six categories of toxicity endpoints. Results of these two methods of ecological risk assessment were consistent with each other, and the risk level of ATZ to aquatic organisms reached highest as taking reproductive fitness into account. The joint probability indicated that severe ecological risk rooting in reproduction might exist 93.9% and 99.9% of surface water in the Taizi River, while 5% threshold (HC 5 ) and 1% threshold (HC 1 ) were set up to protect aquatic organisms, respectively. We hope the present work could provide valuable information to manage and control ATZ pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

Ecological risk assessment of nonylphenol in coastal waters of China based on species sensitivity distribution model.

PubMed

Gao, Pei; Li, Zhengyan; Gibson, Mark; Gao, Huiwang

2014-06-01

Nonylphenol (NP) is an endocrine disruptor and causes feminization and carcinogenesis in various organisms. Consequently, the environmental distribution and ecological risks of NP have received wide concern. China accounts for approximately 10% of the total NP usage in the world, but the water quality criteria of NP have not been established in China and the ecological risks of this pollutant cannot be properly assessed. This study thus aims to determine the predicted no effect concentration (PNEC) of NP and to assess the ecological risks of NP in coastal waters of China with the PNEC as water quality criteria. To obtain the HC5 (hazardous concentration for 5% of biological species) and PNEC estimates, the species sensitivity distributions (SSDs) models were built with chronic toxicity data of NP on aquatic organisms screened from the US Environmental Protection Agency (USEPA) ECOTOX database. The results showed that the PNEC for NP in freshwater and seawater was 0.48 μg L(-1) and 0.28 μg L(-1), respectively. The RQ (risk quotient) values of NP in coastal waters of China ranged from 0.01 to 69.7. About 60% of the reported areas showed a high ecological risk with an RQ value ≥ 1.00. NP therefore exists ubiquitously in coastal waters of China and it poses various risks to aquatic ecosystems in the country. This study demonstrates that the SSD methodology can provide a feasible tool for the establishment of water quality criteria for emergent new pollutants when sufficient toxicity data is available. Copyright © 2013 Elsevier Ltd. All rights reserved.

Occurrence and effects of tire wear particles in the environment--a critical review and an initial risk assessment.

PubMed

Wik, Anna; Dave, Göran

2009-01-01

This review summarizes the existing knowledge on the occurrence of tire wear particles in the environment, and their ecotoxicological effects. A meta-analysis on tire components in the environment revealed that tire wear particles are present in all environmental compartments, including air, water, soils/sediments, and biota. The maximum Predicted Environmental Concentrations (PECs) of tire wear particles in surface waters range from 0.03 to 56 mg l(-1) and the maximum PECs in sediments range from 0.3 to 155 g kg(-1) d.w. The results from our previous long-term studies with Ceriodaphnia dubia and Pseudokirchneriella subcapitata were used to derive Predicted No Effect Concentrations (PNECs). The upper ranges for PEC/PNEC ratios in water and sediment were >1, meaning that tire wear particles present potential risks for aquatic organisms. We suggest that management should be directed towards development and production of more environmentally friendly tires and improved road runoff treatment.

Presence, fate and effects of the intense sweetener sucralose in the aquatic environment.

PubMed

Tollefsen, Knut Erik; Nizzetto, Luca; Huggett, Duane B

2012-11-01

Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda, has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 μg/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations >9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be well below 1 (PEC/PNEC=0.08), thus indicating a limited risk to the environment using traditional ecological risk assessment approaches. Copyright © 2012 Elsevier B.V. All rights reserved.

Occurrence and risk assessment of an azo dye - The case of Disperse Red 1.

PubMed

Vacchi, Francine Inforçato; Von der Ohe, Peter Carsten; Albuquerque, Anjaína Fernandes de; Vendemiatti, Josiane Aparecida de Souza; Azevedo, Carina Cristina Jesus; Honório, Jaqueline Gonçalves; Silva, Bianca Ferreira da; Zanoni, Maria Valnice Boldrin; Henry, Theodore B; Nogueira, Antonio J; Umbuzeiro, Gisela de Aragão

2016-08-01

Water quality criteria to protect aquatic life are not available for most disperse dyes which are often used as commercial mixtures in textile coloration. In this study, the acute and chronic toxicity of the commercial dye Disperse Red 1 (DR1) to eight aquatic organisms from four trophic levels was evaluated. A safety threshold, i.e. Predicted No-Effect Concentration (PNEC), was derived based on the toxicity information of the commercial product and the purified dye. This approach was possible because the toxicity of DR1 was accounting for most of the toxicity of the commercial mixture. A long-term PNEC of 60 ng L(-1) was proposed, based on the most sensitive chronic endpoint for Daphnia similis. A short-term PNEC of 1800 ng L(-1) was proposed based on the most sensitive acute endpoint also for Daphnia similis. Both key studies have been evaluated with the new "Criteria for Reporting and Evaluating ecotoxicity Data" (CRED) methodology, applying more objective criteria to assess the quality of toxicity tests, resulting in two reliable and relevant endpoints with only minor restrictions. HPLC-MS/MS was used to quantify the occurrence of DR1 in river waters of three sites, influenced by textile industry discharges, resulting in a concentration range of 50-500 ng L(-1). The risk quotients for DR1 obtained in this work suggest that this dye can pose a potential risk to freshwater biota. To reduce uncertainty of the derived PNEC, a fish partial or full lifecycle study should be performed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Environmental risk assessment of paroxetine.

PubMed

Cunningham, Virginia L; Constable, David J C; Hannah, Robert E

2004-06-15

Paroxetine hydrochloride hemihydrate (the active ingredient in Paxil) is a pharmaceutical compound used for the treatment of depression, social anxiety disorder, obsessive compulsive disorder, panic disorder, and generalized anxiety disorder. Paroxetine (PA) is extensively metabolized in humans, with about 97% of the parent compound being excreted as metabolites through the urine and feces of patients. Therefore PA and metabolites have the potential to be discharged into wastewater treatment systems after therapeutic use. PA and its major human metabolite (PM) were investigated using studies designed to describe physical/chemical characteristics and determine their fate and effects in the aquatic environment. A significant portion of the PM entering a wastewater treatment plant would be expected to biodegrade given the higher activated sludge solids concentrations present in a typical wastewater treatment plant. The potential for direct photolysis of PM is also possible based on photolysis results for PA itself. These results provide strong support for expecting that PA and PM residuals will not persist in the aquatic environment after discharge from a wastewater treatment facility. This conclusion is also supported by the results of a USGS monitoring study, where no PM was detected in any of the samples at the 260 ng/L reporting limit. The results presented here also demonstrate the importance of understanding the human metabolism of a pharmaceutical so that the appropriate molecule(s) is used for fate and effects studies. In addition to the PA fate studies, PM was investigated using studies designed to determine potential environmental effects and a predicted no effect level (PNEC). The average measured activated sludge respiration inhibition value (EC50) for PM was 82 mg/L. The measured Microtox EC50 value was 33.0 mg/L, while the Daphnia magna EC50 value was 35.0 mg/L. The PNEC for PM was calculated to be 35.0 microg/L. Fate data were then used in a new watershed-based environmental risk assessment model, PhATE, to predict environmental concentrations (PECs). Comparison of the calculated PECs with the PNEC allows an assessment of potential environmental risk. Within the 1-99% of stream segments in the PhATE model, PEC values ranged from 0.003 to 100 ng/L. The risk assessment PEC/PNEC ratios ranged from approximately 3 x 10(-8) to approximately 3 x 10(-3), indicating a wide margin of safety, since a PEC/PNEC ratio <1 is generally considered to represent a low risk to the environment. In addition, Microtox studies carried out on PM biodegradation byproducts indicated no detectable residual toxicity. Any compounds in the environment as a result of the biodegradation of PM should be innocuous polar byproducts that should not exert any toxic effects.

Ecological risk assessment of microcystin-LR in the upstream section of the Haihe River based on a species sensitivity distribution model.

PubMed

Niu, Zhiguang; Du, Lei; Li, Jiafu; Zhang, Ying; Lv, Zhiwei

2018-02-01

The eutrophication of surface water has been the main problem of water quality management in recent decades, and the ecological risk of microcystin-LR (MC-LR), which is the by-product of eutrophication, has drawn more attention worldwide. The aims of our study were to determine the predicted no effect concentration (PNEC) of MC-LR and to assess the ecological risk of MC-LR in the upstream section of the Haihe River. HC 5 (hazardous concentration for 5% of biological species) and PNEC were obtained from a species sensitivity distribution (SSD) model, which was constructed with the acute toxicity data of MC-LR on aquatic organisms. The concentrations of MC-LR in the upstream section of the Haihe River from April to August of 2015 were analysed, and the ecological risk characteristics of MC-LR were evaluated based on the SSD model. The results showed that the HC 5 of MC-LR in freshwater was 17.18 μg/L and PNEC was 5.73 μg/L. The concentrations of MC-LR ranged from 0.68 μg/L to 32.21 μg/L and were obviously higher in summer than in spring. The values of the risk quotient (RQ) ranged from 0.12 to 5.62, suggesting that the risk of MC-LR for aquatic organisms in the river was at a medium or high level during the study period. Compared with other waterbodies in the world, the pollution level of MC-LR in the Haihe River was at a moderate level. This research could promote the study of the ecological risk of MC-LR at the ecosystem level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ubiquity of Polynucleobacter necessarius subsp. asymbioticus in lentic freshwater habitats of a heterogenous 2000 km2 area

PubMed Central

Jezberová, Jitka; Jezbera, Jan; Brandt, Ulrike; Lindström, Eva S.; Langenheder, Silke; Hahn, Martin W.

2010-01-01

Summary We present a survey on the distribution and habitat range of P. necessarius subspecies asymbioticus (PnecC), an important taxon in the water column of freshwater systems. We systematically sampled stagnant freshwater habitats in a heterogeneous 2000 km2 area, together with ecologically different habitats outside this area. In total, 137 lakes, ponds and puddles were investigated, which represent an enormous diversity of habitats differing, i.e., in depth (<10 cm – 171 m) and pH (3.9 – 8.5). PnecC was detected by cultivation-independent methods in all investigated habitats, and its presence was confirmed by cultivation of strains from selected habitats including the most extreme ones. The determined relative abundance of the subspecies ranged from slightly above 0% to 67% (average 14.5% ± 14.3%), and the highest observed absolute abundance was 5.3×106 cells mL−1. Statistical analyses revealed that the abundance of PnecC is partially controlled by factors linked to concentrations of humic substances, which might support the hypothesis that these bacteria utilize photodegradation products of humic substances. . Statistical analyses revealed that the abundance of PnecC is partially controlled by low conductivity and pH and factors linked to concentrations of humic substances. Based on the revealed statistical relationships, an average relative abundance of this subspecies of 20% in global freshwater habitats was extrapolated. Our study provides important implications for the current debate on ubiquity and biogeography in microorganisms. PMID:20041938

Rational selection of alternative, environmentally compatible surfactants for biotechnological production of pharmaceuticals--a step toward green biotechnology.

PubMed

Straub, Jürg Oliver; Shearer, Russel; Studer, Martin

2014-09-01

The biotechnological production of pharmaceutical active substances needs ancillary substances. Surfactants are used at the end of the cell culture as a protection against potential viral or bacterial contamination and to lyse the producing cells for isolation and purification of the products. To find a replacement for a surfactant that had raised environmental concern, environmentally relevant data for potential alternatives were searched for in the literature. Significant data gaps were filled with additional tests: biodegradability, algal growth inhibition, acute daphnid immobilization and chronic daphnid reproduction toxicity, acute fish toxicity, and activated sludge respiration inhibition. The results were used to model removal in the wastewater treatment plants (WWTPs) serving 3 biotechnological production sites in the Roche Group. Predicted environmental concentrations (PECs) were calculated using realistic amounts of surfactants and site-specific wastewater fluxes, modeled removals for the WWTPs and dilution factors by the respective receiving waters. Predicted no-effect concentrations (PNECs) were derived for WWTPs and for both fresh and marine receiving waters as the treated wastewater of 1 production site is discharged into a coastal water. This resulted in a spreadsheet showing PECs, PNECs, and PEC ÷ PNEC risk characterization ratios for the WWTPs and receiving waters for all investigated surfactants and all 3 sites. This spreadsheet now serves as a selection support for the biotechnological developers. This risk-based prioritization of surfactants is a step toward green biotechnological production. © 2014 SETAC.

A toxicity-based method for evaluating safety of reclaimed water for environmental reuses.

PubMed

Xu, Jianying; Zhao, Chuntao; Wei, Dongbin; Du, Yuguo

2014-10-01

A large quantity of toxic chemical pollutants possibly remains in reclaimed water due to the limited removal efficiency in traditional reclamation processes. It is not enough to guarantee the safety of reclaimed water using conventional water quality criteria. An integrated assessment method based on toxicity test is necessary to vividly depict the safety of reclaimed water for reuse. A toxicity test battery consisting of lethality, genotoxicity and endocrine disrupting effect was designed to screen the multiple biological effects of residual toxic chemicals in reclaimed water. The toxicity results of reclaimed water were converted into the equivalent concentrations of the corresponding positive reference substances (EQC). Simultaneously, the predicted no-effect concentration (PNEC) of each positive reference substance was obtained by analyzing the species sensitivity distribution (SSD) of toxicity data. An index "toxicity score" was proposed and valued as 1, 2, 3, or 4 depending on the ratio of the corresponding EQC to PNEC. For vividly ranking the safety of reclaimed water, an integrated assessment index "toxicity rank" was proposed, which was classified into A, B, C, or D rank with A being the safest. The proposed method was proved to be effective in evaluating reclaimed water samples in case studies. Copyright © 2014. Published by Elsevier B.V.

Ecotoxicological evaluation of propranolol hydrochloride and losartan potassium to Lemna minor L. (1753) individually and in binary mixtures.

PubMed

Godoy, Aline A; Kummrow, Fábio; Pamplin, Paulo Augusto Z

2015-07-01

Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.

Subsea release of oil from a riser: an ecological risk assessment.

PubMed

Nazir, Muddassir; Khan, Faisal; Amyotte, Paul; Sadiq, Rehan

2008-10-01

This study illustrates a newly developed methodology, as a part of the U.S. EPA ecological risk assessment (ERA) framework, to predict exposure concentrations in a marine environment due to underwater release of oil and gas. It combines the hydrodynamics of underwater blowout, weathering algorithms, and multimedia fate and transport to measure the exposure concentration. Naphthalene and methane are used as surrogate compounds for oil and gas, respectively. Uncertainties are accounted for in multimedia input parameters in the analysis. The 95th percentile of the exposure concentration (EC(95%)) is taken as the representative exposure concentration for the risk estimation. A bootstrapping method is utilized to characterize EC(95%) and associated uncertainty. The toxicity data of 19 species available in the literature are used to calculate the 5th percentile of the predicted no observed effect concentration (PNEC(5%)) by employing the bootstrapping method. The risk is characterized by transforming the risk quotient (RQ), which is the ratio of EC(95%) to PNEC(5%), into a cumulative risk distribution. This article describes a probabilistic basis for the ERA, which is essential from risk management and decision-making viewpoints. Two case studies of underwater oil and gas mixture release, and oil release with no gaseous mixture are used to show the systematic implementation of the methodology, elements of ERA, and the probabilistic method in assessing and characterizing the risk.

Mechanical stretch-induced serotonin release from pulmonary neuroendocrine cells: implications for lung development.

PubMed

Pan, Jie; Copland, Ian; Post, Martin; Yeger, Herman; Cutz, Ernest

2006-01-01

Pulmonary neuroendocrine cells (PNEC) produce amine (serotonin, 5-HT) and peptides (e.g., bombesin, calcitonin) with growth factor-like properties and are thought to play an important role in lung development. Because physical forces are essential for lung growth and development, we investigated the effects of mechanical strain on 5-HT release in PNEC freshly isolated from rabbit fetal lung and in the PNEC-related tumor H727 cell line. Cultures exposed to sinusoidal cyclic stretch showed a significant 5-HT release inhibitable with gadolinium chloride (10 nM), a blocker of mechanosensitive channels. In contrast to hypoxia (Po2 approximately 20 mmHg), stretch-induced 5-HT release was not affected by Ca2+-free medium or nifedipine (50 microM), excluding the exocytic pathway. In H727 cells, stretch failed to release calcitonin, a peptide stored within dense core vesicles (DCV), whereas hypoxia caused massive calcitonin release. 5-HT released by mechanical stretch is derived predominantly from the cytoplasmic pool, because it is rapid ( approximately 5 min) and is releasable from early (20 days of gestation) fetal PNEC containing few DCV. Both mechanical stretch and hypoxia upregulated expression of tryptophan hydroxylase, the rate-limiting enzyme of 5-HT synthesis. We conclude that mechanical strain is an important physiological stimulus for the release of 5-HT from PNEC via mechanosensitive channels with potential effects on lung development and resorption of lung fluid at the time of birth.

Argininosuccinate synthetase (ASS) deficiency in high-grade pulmonary neuroendocrine carcinoma: an opportunity for personalized targeted therapy.

PubMed

Walts, Ann E; Bomalaski, John S; Ines, Delma; Orsulic, Sandra

2015-08-01

Cells deficient in argininosuccinate synthetase (ASS) must absorb the arginine they need for growth from circulating blood. Treatment with pegylated arginine deiminase (ADI-PEG 20) selectively eliminates arginine from the circulation and has shown some efficacy against ASS-deficient tumors including small cell lung cancer (SCLC). We sought to assess ASS expression in a cohort of high-grade pulmonary neuroendocrine carcinomas (PNEC) which include SCLC and large cell neuroendocrine carcinoma (LCNEC). Sixty-nine PNEC (49 SCLC and 20 LCNEC) were retrieved from our pathology archives. Formalin-fixed paraffin-embedded sections of the 54 primary tumors, 15 metastases and appropriate positive and negative controls were immunostained using an ASS-specific monoclonal antibody. Positive staining in <30 % of the tumor was scored as weak; staining in ≥30 % of the tumor was scored as strong. The absence of staining in the tumor was recorded as ASS negative. 58 % of the PNEC including 61.2 % of the SCLC and 50 % of the LCNEC were ASS negative. These ASS-negative tumors included 63 % of the primary and 40 % of the metastatic lesions tested. More than 50 % of the high-grade PNEC tested lack immunohistochemically detectable ASS, suggesting that they are auxotrophic for arginine and potential candidates for arginine deprivation therapy. PNEC comprise about 25 % of primary lung cancers and have a 5-year overall survival of only 5-10 %, underscoring the need for new and more effective therapies. Immunostaining for ASS has potential to improve the selection of patients with PNEC for arginine deprivation therapy with ADI-PEG 20.

Review: ecotoxicity of organic and organo-metallic antifouling co-biocides and implications for environmental hazard and risk assessments in aquatic ecosystems.

PubMed

Martins, Samantha Eslava; Fillmann, Gilberto; Lillicrap, Adam; Thomas, Kevin V

2018-01-01

Hazard assessments of Irgarol 1051, diuron, 2-(thiocyanomethylthio)benzothiazole (TCMTB), dichloro-octylisothiazolin (DCOIT), chlorothalonil, dichlofluanid, thiram, zinc pyrithione, copper pyrithione, triphenylborane pyridine (TPBP), capsaicin, nonivamide, tralopyril and medetomidine were performed to establish robust environmental quality standards (EQS), based on predicted no effect concentrations (PNECs). Microalgae, zooplankton, fish and amphibians were the most sensitive ecological groups to all the antifoulants evaluated, especially in the early life stages. No differences were identified between freshwater and seawater species. The use of toxicity tests with non-standard species is encouraged because they increase the datasets, allowing EQS to be derived from probabilistic-based PNECs whilst reducing uncertainties. The global ban of tributyltin (TBT) has been heralded as a major environmental success; however, substitute antifoulants may also pose risks to aquatic ecosystems. Environmental risk assessments (ERAs) have driven decision-makings for regulating antifouling products, but in many countries there is still a lack of regulation of antifouling biocides which should be addressed.

Applying adverse outcome pathways and species sensitivity-weighted distribution to predicted-no-effect concentration derivation and quantitative ecological risk assessment for bisphenol A and 4-nonylphenol in aquatic environments: A case study on Tianjin City, China.

PubMed

Wang, Ying; Na, Guangshui; Zong, Humin; Ma, Xindong; Yang, Xianhai; Mu, Jingli; Wang, Lijun; Lin, Zhongsheng; Zhang, Zhifeng; Wang, Juying; Zhao, Jinsong

2018-02-01

Adverse outcome pathways (AOPs) are a novel concept that effectively considers the toxic modes of action and guides the ecological risk assessment of chemicals. To better use toxicity data including biochemical or molecular responses and mechanistic data, we further developed a species sensitivity-weighted distribution (SSWD) method for bisphenol A and 4-nonylphenol. Their aquatic predicted-no-effect concentrations (PNECs) were derived using the log-normal statistical extrapolation method. We calculated aquatic PNECs of bisphenol A and 4-nonylphenol with values of 4.01 and 0.721 µg/L, respectively. The ecological risk of each chemical in different aquatic environments near Tianjin, China, a coastal municipality along the Bohai Sea, was characterized by hazard quotient and probabilistic risk quotient assessment techniques. Hazard quotients of 7.02 and 5.99 at 2 municipal sewage sites using all of the endpoints were observed for 4-nonylphenol, which indicated high ecological risks posed by 4-nonylphenol to aquatic organisms, especially endocrine-disrupting effects. Moreover, a high ecological risk of 4-nonylphenol was indicated based on the probabilistic risk quotient method. The present results show that combining the SSWD method and the AOP concept could better protect aquatic organisms from adverse effects such as endocrine disruption and could decrease uncertainty in ecological risk assessment. Environ Toxicol Chem 2018;37:551-562. © 2017 SETAC. © 2017 SETAC.

Concentrations of levonorgestrel and ethinylestradiol in wastewater effluents: Is the progestin also cause for concern?

PubMed

King, Olivia C; van de Merwe, Jason P; McDonald, James A; Leusch, Frederic D L

2016-06-01

Synthetic hormones have been widely reported in treated sewage effluents, and consequently receiving aquatic environments. Ethinylestradiol (EE2) is a potent synthetic estrogen commonly used in conjunction with levonorgestrel in oral contraceptive pills. Both EE2 and levonorgestrel have been identified in the aquatic environment, but although there is a significant amount of literature on EE2, there is much less information on levonorgestrel. Using Australian prescription data as well as excretion and predicted wastewater removal rates, the concentrations of EE2 and levonorgestrel in Australian wastewater were calculated at 0.1 ng/L to 0.5 ng/L and 0.2 ng/L to 0.6 ng/L, respectively. Both compounds were analyzed in treated wastewater and surface water grab samples from 3 Southeast Queensland, Australia sites. The predicted no-effect concentration (PNEC) for EE2 of 0.1 ng/L was exceeded at most sites, with EE2 concentrations up to 2 ng/L in treated effluent, albeit quickly diluted to 0.1 ng/L to 0.2 ng/L in the receiving environment. A provisional PNEC for levonorgestrel of 0.1 ng/L derived in the present study was slightly lower than predicted effluent concentrations of 0.2 ng/L to 0.6 ng/L, indicating a potential risk of endocrine-related effects in exposed aquatic species. The detection limit for levonorgestrel in the present study was 2.5 ng/L, and all samples were below detection limit. The present study's results suggest that improvements in analytical capabilities for levonorgestrel are warranted to more accurately quantify the risk of this compound in the receiving environment. Environ Toxicol Chem 2016;35:1378-1385. © 2015 SETAC. © 2015 SETAC.

Does monensin in chicken manure from poultry farms pose a threat to soil invertebrates?

PubMed

Zižek, Suzana; Hrženjak, Rok; Kalcher, Gabrijela Tavčar; Srimpf, Karin; Semrov, Neva; Zidar, Primož

2011-04-01

Monensin is a carboxylic polyether ionophore used in the poultry industry as a coccidiostat. It enters the environment via manure from broiler farms. In spite of its potential presence in the environment, information concerning monensin residues in manure and soil and its toxicity to soil organisms are insufficient. In the present study, two beneficial soil invertebrate species, earthworms (Eisenia andrei) and woodlice (Porcellio scaber), were used to assess the toxicity of monensin. Animals were exposed to a range of monensin concentrations via soil or food. Earthworm reproduction was found to be the most susceptible endpoint (NOEC=3.5 mg kg(-1) dry soil; EC(50)=12.7 mg kg(-1) dry soil), while no adverse effects were recorded in isopods (NOEC⩾849mgkg(-1) dry soil, NOEC⩾357mgkg(-1) dry food). The obtained toxicity data were compared with potential concentrations of monensin in soil. In view of this, manure from broiler chickens treated with monensin at a poultry farm was sampled. According to monensin and nitrogen concentrations in the chicken manure and the degradation time of monensin, the predicted environmental concentration (PEC) was calculated. PEC of monensin is around 0.013 mg kg(-1) soil if manure is used after 3 months of composting and 0.05 mg kg(-1) soil if used without storage. Data for earthworm reproduction was used to estimate the predicted no-effect concentration (PNEC). If fresh chicken manure is applied to terrestrial ecosystems, the risk quotient (PEC/PNEC ratio) is above 1, which indicates that monensin might pose an environmental risk under certain conditions. To prevent this, it is strongly recommended to compost chicken manure for several months before using it as fertiliser. Copyright © 2010 Elsevier Ltd. All rights reserved.

Environmental risk assessment on capsaicin used as active substance for antifouling system on ships.

PubMed

Wang, Jianbing; Shi, Ting; Yang, Xiaoling; Han, Wenya; Zhou, Yunrui

2014-06-01

Biodegradation experiments were carried out with capsaicin to evaluate its degradability. The results show that capsaicin was readily biodegradable under aerobic conditions. The values of Kow and the calculated bioconcentration factor indicate that capsaicin have a low potential for bioconcentration. The fish acute toxicity tests conducted with Brachydanio rerio show LC50 for capsaicin was 5.98 mg L(-1). The tests of alga growth inhibition conducted with Selenastrum capricornutum suggest EC50 for capsaicin was 114 mg L(-1). The calculated PNEC (Predicted No Effect Concentration) was 4.9×10(-4) mg L(-1). The average PEC (Predicted Environmental Concentration) for OECD-EU commercial harbor and marina were 3.99×10(-6) and 2.49×10(-5) mg L(-1), respectively. These indicate that the PEC was much less than the PNEC for capsaicin. The low Kp value of capsaicin suggests the data about the risk of capsaicin to sediment organisms can be waived. According to the results from the analysis of the degradation, bioaccumulation, toxicity and accumulation in sediment, it can be concluded that capsaicin used as active substance for antifouling system on ships poses relatively low risk to marine environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Review of measured concentrations of triphenyltin compounds in marine ecosystems and meta-analysis of their risks to humans and the environment.

PubMed

Yi, Andy Xianliang; Leung, Kenneth M Y; Lam, Michael H W; Lee, Jae-Seong; Giesy, John P

2012-11-01

The state of scientific knowledge regarding analytical methods, environmental fate, ecotoxicity and ecological risk of triphenyltin (TPT) compounds in marine ecosystems as well as their exposure and health hazard to humans was reviewed. Since the 1960s, TPT compounds have been commonly applied as biocides for diverse industrial and agricultural purposes. For instance, they are used as active ingredients in antifouling systems on marine vessels and mariculture facilities, and as fungicides in agriculture. Due to their intensive use, contamination of coastal waters by TPT and its products of transformation has become a worldwide problem. The proportion of quantified TPT to total phenyltin compounds in the marine environment provides evidence that TPT is photodegradable in water and sediment but resistant to biotransformation. Concentrations of TPT in marine biota are consistently greater than concentrations in water and sediment, which implies potential of TPT to bioaccumulate. TPT is toxic to both marine plants and animals. The predicted no effect concentration (PNEC) for TPT, as determined by use of the species sensitivity distribution approach, is 0.64 ng L(-1). In some parts of the world, concentrations of TPT in seawater exceed the PNEC, indicating that TPT can pose risks to marine life. Although there is negligible risk of TPT to average human consumers, TPT has been detected in blood of Finnish people and the concentration was greater in fishermen who ate more seafood. It is, therefore, advocated to initiate regular monitoring of TPT in blood and breast milk of populations that consume greater amounts of seafood. Copyright © 2012 Elsevier Ltd. All rights reserved.

Probabilistic determination of the ecological risk from OTNE in aquatic and terrestrial compartments based on US-wide monitoring data.

PubMed

McDonough, Kathleen; Casteel, Kenneth; Zoller, Ann; Wehmeyer, Kenneth; Hulzebos, Etje; Rila, Jean-Paul; Salvito, Daniel; Federle, Thomas

2017-01-01

OTNE [1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one; trade name Iso E Super] is a fragrance ingredient commonly used in consumer products which are disposed down the drain. This research measured effluent and sludge concentrations of OTNE at 44 US wastewater treatment plants (WWTP). The mean effluent and sludge concentrations were 0.69 ± 0.65 μg/L and 20.6 ± 33.8 mg/kg dw respectively. Distribution of OTNE effluent concentrations and dilution factors were used to predict surface water and sediment concentrations and distributions of OTNE sludge concentrations and loading rates were used to predict terrestrial concentrations. The 90th percentile concentration of OTNE in US WWTP mixing zones was predicted to be 0.04 and 0.85 μg/L under mean and 7Q10 low flow (lowest river flow occurring over a 7 day period every 10 years) conditions respectively. The 90th percentile sediment concentrations under mean and 7Q10 low flow conditions were predicted to be 0.081 and 1.6 mg/kg dw respectively. Based on current US sludge application practices, the 90th percentile OTNE terrestrial concentration was 1.38 mg/kg dw. The probability of OTNE concentrations being below the predicted no effect concentration (PNEC) for the aquatic and sediment compartments was greater than 99%. For the terrestrial compartment, the probability of OTNE concentrations being lower than the PNEC was 97% for current US sludge application practices. Based on the results of this study, OTNE concentrations in US WWTP effluent and sludge do not pose an ecological risk to aquatic, sediment and terrestrial organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Presence of antibiotic residues in various environmental compartments of Shandong province in eastern China: Its potential for resistance development and ecological and human risk.

PubMed

Hanna, Nada; Sun, Pan; Sun, Qiang; Li, Xuewen; Yang, Xiwei; Ji, Xiang; Zou, Huiyun; Ottoson, Jakob; Nilsson, Lennart E; Berglund, Björn; Dyar, Oliver James; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia

2018-05-01

To investigate the occurrence of antibiotic residues in different types of environmental samples including water samples in rural Shandong province, China. Further, to characterize the potential ecological risk for development of antibiotic resistance in the environment, and the potential direct human health risk of exposure to antibiotics via drinking water and vegetables. Environmental samples (n = 214) (river water, waste water, drinking water, sediments, manure, soil and edible parts of vegetables) were collected in twelve villages in Shandong province in eastern China. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine the concentration of antibiotic residues. The ratio of the measured environmental concentrations (MEC) to the predicted no-effect concentrations (PNEC) was used to evaluate the ecological risk (risk quotient, RQ) for development of antibiotic resistance. The potential risks to human health through exposure to antibiotics in drinking water were assessed by comparing measured environmental concentrations (MEC) and predicted no-effect concentration in drinking water (PNEC DW ), and in vegetables by comparing estimated daily intake (EDI) to ADI. Sulfapyridine, sulfamethoxazole, ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, chloramphenicol, florfenicol, doxycycline, and metronidazole were detected at concentrations ranging between 0.3 and 3.9 ng/L in river water, 1.3 and 12.5 ng/L in waste water, 0.5 and 21.4 ng/L in drinking water, 0.31 and 1.21 μg/kg in river sediment, 0.82 and 1.91 μg/kg in pig manure, 0.1 and 11.68 μg/kg in outlet sediment, 0.5 and 2.5 μg/kg in soil, and 6.3 and 27.2 μg/kg in vegetables. The RQs for resistance development were >1 for enrofloxacin, levofloxacin, and ranged between 0.1 and 1 for ciprofloxacin. MECs/PNEC DW ratios were <1 from exposure to antibiotics through drinking water for both adults and children. EDI/ADI ratios were <0.1 from exposure to antibiotics by vegetable consumption. Antibiotic pollutants were ubiquitous in various environmental compartments of Shandong province of China. Risk estimates indicated a potential for the measured levels of enrofloxacin, levofloxacin and ciprofloxacin in waste water to pose an ecological risk for resistance selection, and further studies are needed to validate this finding. The investigated antibiotics did not appear to pose an appreciable direct human health risk from environmental exposure through drinking water or vegetables consumption. However, they might still pose a risk for resistance development. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Probabilistic approaches to accounting for data variability in the practical application of bioavailability in predicting aquatic risks from metals.

PubMed

Ciffroy, Philippe; Charlatchka, Rayna; Ferreira, Daniel; Marang, Laura

2013-07-01

The biotic ligand model (BLM) theoretically enables the derivation of environmental quality standards that are based on true bioavailable fractions of metals. Several physicochemical variables (especially pH, major cations, dissolved organic carbon, and dissolved metal concentrations) must, however, be assigned to run the BLM, but they are highly variable in time and space in natural systems. This article describes probabilistic approaches for integrating such variability during the derivation of risk indexes. To describe each variable using a probability density function (PDF), several methods were combined to 1) treat censored data (i.e., data below the limit of detection), 2) incorporate the uncertainty of the solid-to-liquid partitioning of metals, and 3) detect outliers. From a probabilistic perspective, 2 alternative approaches that are based on log-normal and Γ distributions were tested to estimate the probability of the predicted environmental concentration (PEC) exceeding the predicted non-effect concentration (PNEC), i.e., p(PEC/PNEC>1). The probabilistic approach was tested on 4 real-case studies based on Cu-related data collected from stations on the Loire and Moselle rivers. The approach described in this article is based on BLM tools that are freely available for end-users (i.e., the Bio-Met software) and on accessible statistical data treatments. This approach could be used by stakeholders who are involved in risk assessments of metals for improving site-specific studies. Copyright © 2013 SETAC.

Effects of short-chain chlorinated paraffins on soil organisms.

PubMed

Bezchlebová, Jitka; Cernohlávková, Jitka; Kobeticová, Klára; Lána, Jan; Sochová, Ivana; Hofman, Jakub

2007-06-01

Despite the fact that chlorinated paraffins have been produced in relatively large amounts, and high concentrations have been found in sewage sludge applied to soils, there is little information on their concentrations in soils and the effect on soil organisms. The aim of this study was to investigate the toxicity of chlorinated paraffins in soils. The effects of short-chain chlorinated paraffins (64% chlorine content) on invertebrates (Eisenia fetida, Folsomia candida, Enchytraeus albidus, Enchytraeus crypticus, Caenorhabditis elegans) and substrate-induced respiration of indigenous microorganisms were studied. Differences were found in the sensitivity of the tested organisms to short-chain chlorinated paraffins. F. candida was identified as the most sensitive organism with LC(50) and EC(50) values of 5733 and 1230 mg/kg, respectively. Toxicity results were compared with available studies and the predicted no effect concentration (PNEC) of 5.28 mg/kg was estimated for the soil environment, based on our data.

Environmental risk assessment of engineered nano-SiO2 , nano iron oxides, nano-CeO2 , nano-Al2 O3 , and quantum dots.

PubMed

Wang, Yan; Nowack, Bernd

2018-05-01

Many research studies have endeavored to investigate the ecotoxicological hazards of engineered nanomaterials (ENMs). However, little is known regarding the actual environmental risks of ENMs, combining both hazard and exposure data. The aim of the present study was to quantify the environmental risks for nano-Al 2 O 3 , nano-SiO 2 , nano iron oxides, nano-CeO 2 , and quantum dots by comparing the predicted environmental concentrations (PECs) with the predicted-no-effect concentrations (PNECs). The PEC values of these 5 ENMs in freshwaters in 2020 for northern Europe and southeastern Europe were taken from a published dynamic probabilistic material flow analysis model. The PNEC values were calculated using probabilistic species sensitivity distribution (SSD). The order of the PNEC values was quantum dots < nano-CeO 2  < nano iron oxides < nano-Al 2 O 3  < nano-SiO 2 . The risks posed by these 5 ENMs were demonstrated to be in the reverse order: nano-Al 2 O 3  > nano-SiO 2  > nano iron oxides > nano-CeO 2  > quantum dots. However, all risk characterization values are 4 to 8 orders of magnitude lower than 1, and no risk was therefore predicted for any of the investigated ENMs at the estimated release level in 2020. Compared to static models, the dynamic material flow model allowed us to use PEC values based on a more complex parameterization, considering a dynamic input over time and time-dependent release of ENMs. The probabilistic SSD approach makes it possible to include all available data to estimate hazards of ENMs by considering the whole range of variability between studies and material types. The risk-assessment approach is therefore able to handle the uncertainty and variability associated with the collected data. The results of the present study provide a scientific foundation for risk-based regulatory decisions of the investigated ENMs. Environ Toxicol Chem 2018;37:1387-1395. © 2018 SETAC. © 2018 SETAC.

Ethinyl estradiol and other human pharmaceutical estrogens in the aquatic environment: a review of recent risk assessment data.

PubMed

Laurenson, James P; Bloom, Raanan A; Page, Stephen; Sadrieh, Nakissa

2014-03-01

Interest in pharmaceuticals in the environment has increased substantially in recent years. Several studies in particular have assessed human and ecological risks from human pharmaceutical estrogens, such as 17α-ethinyl estradiol (EE2). Regulatory action also has increased, with the USA and other countries developing rules to address estrogens and other pharmaceuticals in the environment. Accordingly, the Center for Drug Evaluation and Research at the US Food and Drug Administration has conducted a review and analysis of current data on the long-term ecological exposure and effects of EE2 and other estrogens. The results indicate that mean-flow long-term predicted environmental concentrations (PECs) of EE2 in approximately 99% or more of US surface water segments downstream of wastewater treatment plants are lower than a predicted no-effect concentration (PNEC) for aquatic chronic toxicity of 0.1 ng/L. Exceedances are expected to be primarily in localized, effluent-dominated water segments. The median mean-flow PEC is more than two orders of magnitude lower than this PNEC. Similar results exist for other pharmaceutical estrogens. Data also suggest that the contribution of EE2 more broadly to total estrogenic load in the environment from all sources (including other human pharmaceutical estrogens, endogenous estrogens, natural environmental estrogens, and industrial chemicals), while highly uncertain and variable, appears to be relatively low overall. Additional data and a more comprehensive approach for data collection and analysis for estrogenic substances in the environment, especially in effluent-dominated water segments in sensitive environments, would more fully characterize the risks.

Patients With Sentinel Acute Pancreatitis of Alcoholic Etiology are at Risk for Organ Failure and Pancreatic Necrosis: A Dual-Center Experience

PubMed Central

Easler, Jeffrey J.; de-Madaria, Enrique; Nawaz, Haq; Moya-Hoyo, Neftalí; Koutroumpakis, Efstratios; Rey-Riveiro, Mónica; Singh, Vijay P.; Acevedo-Piedra, Nelly G.; Whitcomb, David C.; Yadav, Dhiraj; Papachristou, Georgios I.

2016-01-01

Objectives Assess the relationship between alcoholic etiology, tobacco use and severe acute pancreatitis (SAP). Methods Smoking and alcohol exposure were recorded upon admission in a cohort of acute pancreatitis patients within the United States (U.S.). Patients with first, “sentinel” attack of acute pancreatitis (AP) were identified for analysis. Associations between alcohol, smoking and SAP were validated in an independent cohort of patients from Spain. Results U.S. cohort (n=222): Thirty-five% developed organ failure (OF), 35% Pancreatic Necrosis (PNec), and 7% died. OF (54% vs. 33%, p=0.03), PNec (62% vs. 31%, p=0.006), intensive care (ICU) admission (58% vs. 36%, p=0.03) and length of stay (LOS) (20 vs. 8 days, p= 0.007) were greater in alcoholic when compared to other etiologies. Spanish cohort (n=366): Similar differences in outcomes were also found with between alcoholic and non-alcoholic etiologies: OF (24% vs. 8%, p=0.001), PNec (38% vs. 14%, p<0.001), ICU admission (20% vs. 3%, p<0.001), and LOS (17 vs. 11 days, p=0.04). Multivariable analysis confirmed alcoholic etiology to be independently associated with OF and PNec in both cohorts. Conclusions Alcoholic etiology is independently associated with OF and PNec in patients with sentinel AP and is important when evaluating risk for severe disease in AP. PMID:27101573

Functional characterization of pulmonary neuroendocrine cells in lung development, injury, and tumorigenesis

USDA-ARS?s Scientific Manuscript database

Pulmonary neuroendocrine cells (PNECs) are proposed to be the first specialized cell type to appear in the lung, but their ontogeny remains obscure. Although studies of PNECs have suggested their involvement in a number of lung functions, neither their in vivo significance nor the molecular mechanis...

Occurrence and risk assessment of organophosphorus and brominated flame retardants in the River Aire (UK).

PubMed

Cristale, Joyce; Katsoyiannis, Athanasios; Sweetman, Andrew J; Jones, Kevin C; Lacorte, Silvia

2013-08-01

This study presents the occurrence and risk of PBDEs, new brominated and organophosphorus flame retardants along a river affected by urban and industrial pressures (River Aire, UK). Tris(2-choroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris[2-chloro-1-(chloromethyl)ethyl] phosphate (TDCP) and triphenyl phosphate (TPhP) were detected in all samples, with TCPP present at the highest concentrations, ranging from 113 to 26,050 ng L⁻¹. BDE-209 was detected in most of the sampled sites, ranging from 17 to 295 ng L⁻¹, while hexabromobenzene (HBB) and pentabromoethyl benzene (PBEB) were seldom detected. A risk quotients based on predicted no effect concentrations (PNEC) and flame retardants water concentration proved significant risk for adverse effects for algae, Daphnia and fish in sites close to industrial and urban sewage discharges. This study provides a protocol for the risk estimation of priority and new generation flame retardants based on river concentrations and toxicological values. Copyright © 2013 Elsevier Ltd. All rights reserved.

Are engineered nano iron oxide particles safe? an environmental risk assessment by probabilistic exposure, effects and risk modeling.

PubMed

Wang, Yan; Deng, Lei; Caballero-Guzman, Alejandro; Nowack, Bernd

2016-12-01

Nano iron oxide particles are beneficial to our daily lives through their use in paints, construction materials, biomedical imaging and other industrial fields. However, little is known about the possible risks associated with the current exposure level of engineered nano iron oxides (nano-FeOX) to organisms in the environment. The goal of this study was to predict the release of nano-FeOX to the environment and assess their risks for surface waters in the EU and Switzerland. The material flows of nano-FeOX to technical compartments (waste incineration and waste water treatment plants) and to the environment were calculated with a probabilistic modeling approach. The mean value of the predicted environmental concentrations (PECs) of nano-FeOX in surface waters in the EU for a worst-case scenario (no particle sedimentation) was estimated to be 28 ng/l. Using a probabilistic species sensitivity distribution, the predicted no-effect concentration (PNEC) was determined from ecotoxicological data. The risk characterization ratio, calculated by dividing the PEC by PNEC values, was used to characterize the risks. The mean risk characterization ratio was predicted to be several orders of magnitude smaller than 1 (1.4 × 10 - 4 ). Therefore, this modeling effort indicates that only a very limited risk is posed by the current release level of nano-FeOX to organisms in surface waters. However, a better understanding of the hazards of nano-FeOX to the organisms in other ecosystems (such as sediment) needs to be assessed to determine the overall risk of these particles to the environment.

Evolution of the hypoxia-sensitive cells involved in amniote respiratory reflexes

PubMed Central

Hockman, Dorit; Burns, Alan J; Schlosser, Gerhard; Gates, Keith P; Jevans, Benjamin; Mongera, Alessandro; Fisher, Shannon; Unlu, Gokhan; Knapik, Ela W; Kaufman, Charles K; Mosimann, Christian; Zon, Leonard I; Lancman, Joseph J; Dong, P Duc S; Lickert, Heiko; Tucker, Abigail S; Baker, Clare V H

2017-01-01

The evolutionary origins of the hypoxia-sensitive cells that trigger amniote respiratory reflexes – carotid body glomus cells, and ‘pulmonary neuroendocrine cells’ (PNECs) - are obscure. Homology has been proposed between glomus cells, which are neural crest-derived, and the hypoxia-sensitive ‘neuroepithelial cells’ (NECs) of fish gills, whose embryonic origin is unknown. NECs have also been likened to PNECs, which differentiate in situ within lung airway epithelia. Using genetic lineage-tracing and neural crest-deficient mutants in zebrafish, and physical fate-mapping in frog and lamprey, we find that NECs are not neural crest-derived, but endoderm-derived, like PNECs, whose endodermal origin we confirm. We discover neural crest-derived catecholaminergic cells associated with zebrafish pharyngeal arch blood vessels, and propose a new model for amniote hypoxia-sensitive cell evolution: endoderm-derived NECs were retained as PNECs, while the carotid body evolved via the aggregation of neural crest-derived catecholaminergic (chromaffin) cells already associated with blood vessels in anamniote pharyngeal arches. DOI: http://dx.doi.org/10.7554/eLife.21231.001 PMID:28387645

Ecotoxicological potential of the biocides terbutryn, octhilinone and methylisothiazolinone: Underestimated risk from biocidal pathways?

PubMed

Kresmann, Simon; Arokia, Arokia Hansel Rajan; Koch, Christoph; Sures, Bernd

2018-06-01

The use of biocides by industry, agriculture and households increased throughout the last two decades. Many new applications with known substances enriched the variety of biocidal pollution sources for the aquatic environment. While agriculture was the major source for a long time, leaching from building facades and preservation of personal care and cleaning products was identified as new sources in the last few years. With the different usage forms of biocidal products the complexity of legislative regulation increased as well. The requirements for risk assessment differ from one law to another and the potential risk of substances under different regulations might be underestimated. Still EC 50 and predicted no-effect concentration (PNEC) values gained from testing with different species are the core of environmental risk assessment, but ecotoxicological data is limited or lacking for many biocides. In this study the biocides widely used in facade coatings and household products terbutryn, octhilinone and methylisothiazolinone were tested with the Daphnia magna acute immobilisation assay, the neutral red uptake assay and the ethoxyresorufin-O-deethylase (EROD) assay, performed with rainbow trout liver (RTL-W1) cells. Further, the MTT assay with the ovarian cell line CHO-9 from Chinese hamster was used as mammalian model. Octhilinone induced the strongest effects with EC 50 values of 156μg/l in the D. magna assay, while terbutryn showed the weakest effects with 8390μg/l and methylisothiazolinone 513μg/l respectively. All other assays showed higher EC 50 values and thus only weak effects. EROD assays did not show any effects. With additional literature and database records PNEC values were calculated: terbutryn reached 0.003μg/l, octhilinone 0.05μg/l and methylisothiazolinone 0.5μg/l. Potential ecotoxicological risks of these biocides are discussed, considering environmental concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

Environmental Risk Assessment Strategy for Nanomaterials.

PubMed

Scott-Fordsmand, Janeck J; Peijnenburg, Willie J G M; Semenzin, Elena; Nowack, Bernd; Hunt, Neil; Hristozov, Danail; Marcomini, Antonio; Irfan, Muhammad-Adeel; Jiménez, Araceli Sánchez; Landsiedel, Robert; Tran, Lang; Oomen, Agnes G; Bos, Peter M J; Hund-Rinke, Kerstin

2017-10-19

An Environmental Risk Assessment (ERA) for nanomaterials (NMs) is outlined in this paper. Contrary to other recent papers on the subject, the main data requirements, models and advancement within each of the four risk assessment domains are described, i.e., in the: (i) materials, (ii) release, fate and exposure, (iii) hazard and (iv) risk characterisation domains. The material, which is obviously the foundation for any risk assessment, should be described according to the legislatively required characterisation data. Characterisation data will also be used at various levels within the ERA, e.g., exposure modelling. The release, fate and exposure data and models cover the input for environmental distribution models in order to identify the potential (PES) and relevant exposure scenarios (RES) and, subsequently, the possible release routes, both with regard to which compartment(s) NMs are distributed in line with the factors determining the fate within environmental compartment. The initial outcome in the risk characterisation will be a generic Predicted Environmental Concentration (PEC), but a refined PEC can be obtained by applying specific exposure models for relevant media. The hazard information covers a variety of representative, relevant and reliable organisms and/or functions, relevant for the RES and enabling a hazard characterisation. The initial outcome will be hazard characterisation in test systems allowing estimating a Predicted No-Effect concentration (PNEC), either based on uncertainty factors or on a NM adapted version of the Species Sensitivity Distributions approach. The risk characterisation will either be based on a deterministic risk ratio approach (i.e., PEC/PNEC) or an overlay of probability distributions, i.e., exposure and hazard distributions, using the nano relevant models.

Environmental Risk Assessment Strategy for Nanomaterials

PubMed Central

Scott-Fordsmand, Janeck J.; Nowack, Bernd; Hunt, Neil; Hristozov, Danail; Marcomini, Antonio; Irfan, Muhammad-Adeel; Jiménez, Araceli Sánchez; Landsiedel, Robert; Tran, Lang; Oomen, Agnes G.; Bos, Peter M. J.

2017-01-01

An Environmental Risk Assessment (ERA) for nanomaterials (NMs) is outlined in this paper. Contrary to other recent papers on the subject, the main data requirements, models and advancement within each of the four risk assessment domains are described, i.e., in the: (i) materials, (ii) release, fate and exposure, (iii) hazard and (iv) risk characterisation domains. The material, which is obviously the foundation for any risk assessment, should be described according to the legislatively required characterisation data. Characterisation data will also be used at various levels within the ERA, e.g., exposure modelling. The release, fate and exposure data and models cover the input for environmental distribution models in order to identify the potential (PES) and relevant exposure scenarios (RES) and, subsequently, the possible release routes, both with regard to which compartment(s) NMs are distributed in line with the factors determining the fate within environmental compartment. The initial outcome in the risk characterisation will be a generic Predicted Environmental Concentration (PEC), but a refined PEC can be obtained by applying specific exposure models for relevant media. The hazard information covers a variety of representative, relevant and reliable organisms and/or functions, relevant for the RES and enabling a hazard characterisation. The initial outcome will be hazard characterisation in test systems allowing estimating a Predicted No-Effect concentration (PNEC), either based on uncertainty factors or on a NM adapted version of the Species Sensitivity Distributions approach. The risk characterisation will either be based on a deterministic risk ratio approach (i.e., PEC/PNEC) or an overlay of probability distributions, i.e., exposure and hazard distributions, using the nano relevant models. PMID:29048395

Derivation of Soil Ecological Criteria for Copper in Chinese Soils.

PubMed

Wang, Xiaoqing; Wei, Dongpu; Ma, Yibing; McLaughlin, Mike J

2015-01-01

Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database. Second, the compiled data were corrected with leaching and aging factors to minimize the differences between laboratory and field conditions. Before Cu ecotoxicity data were entered into a species sensitivity distribution (SSD), they were normalized with Cu ecotoxicity predictive models to modify the effects of soil properties on Cu ecotoxicity. The PNEC value was set equal to the hazardous concentration for x% of the species (HCx), which could be calculated from the SSD curves, without an additional assessment factor. Finally, predictive models for HCx based on soil properties were developed. The soil properties had a significant effect on the magnitude of HCx, with HC5 varying from 13.1 mg/kg in acidic soils to 51.9 mg/kg in alkaline non-calcareous soils. The two-factor predictive models based on soil pH and cation exchange capacity could predict HCx with determination coefficients (R2) of 0.82-0.91. The three-factor predictive models--that took into account the effect of soil organic carbon--were more accurate than two-factor models, with R2 of 0.85-0.99. The predictive models obtained here could be used to calculate soil-specific criteria. All results obtained here could provide a scientific basis for revision of current Chinese soil environmental quality standards, and the approach adopted in this study could be used as a pragmatic framework for developing soil ecological criteria for other trace elements in soils.

Ecological risk evaluation of combined pollution of herbicide siduron and heavy metals in soils.

PubMed

Jiang, Rong; Wang, Meie; Chen, Weiping; Li, Xuzhi

2018-06-01

Combined pollution of agrichemicals and heavy metals in urban lawn soils were commonly observed throughout the world, and the co-existed two chemicals could interact with each other both in environment behavior and toxic effect. However, little has been reported on the ecological risk of their combined pollution, especially in field due to lack of systematic methodology. In this study, four soils (C, N1, N2, N3) from two public parks in Beijing, China, with similar properties but contrasting heavy metal contaminated level were chosen to assess the ecological risks of co-existed herbicide siduron and heavy metals. Environmental behaviors of siduron in studied soils were investigated with batch experiments in lab, based on which the environmental exposure level of siduron was simulated with HYDRUS-1D. Results suggested that soil organic matter (SOM) rather than the co-existed heavy metals was the dominant factor affecting the fate and the accumulation of siduron in soils. Soil N2 with the highest SOM, showed the strongest tendency to retain siduron among the studied soils. Significant joint effect of siduron and heavy metals on cucumber root elongation was observed through lab experiments. Thus, the joint toxicity of siduron and heavy metals were calculated based on single toxicology data of them using independent action (IA) and concentration addition (CA) model. Then, the predicted no effect concentration (PNEC soil ) of siduron was calculated with equilibrium partitioning method and extrapolation techniques. The PNEC soil of siduron was the lowest in heaviest heavy metal contaminated soil N3. The risk characterization ratios (RCR) of siduron in four soils were all >1. The highest RCR of siduron in soil N3 suggested that it was the joint toxicity of siduron and heavy metals to organisms determining the ecological risks of siduron in combined polluted soils. Copyright © 2018 Elsevier B.V. All rights reserved.

Pharmaceutical management through environmental product labeling in Sweden.

PubMed

Wennmalm, Ake; Gunnarsson, Bo

2009-07-01

There is an increased awareness that medicinal products for human use may cause negative effects in the environment. In Sweden a voluntary environmental classification system for drugs has been established in collaboration between producers, authorities and the public health care, and used for five years. The idea is to enhance the market demand for medicines with less environmental impact, which in turn will stimulate the producers to design future medicines to be more environmentally friendly. The system is open to the public and based on assessment of the active ingredient in the medicinal product into several classes of risk and hazard, respectively. It is closely related to the EMEA guidelines. Risk is expressed as the ratio between the predicted environmental concentration (PEC) of the active ingredient (AI) and its predicted no effect concentration (PNEC). The hazard is expressed in terms of the AI's persistence, potential to bioaccumulation, and eco-toxicity. Drug data for the classification are delivered by the respective producers. Hitherto more than 300 AI, representing more than 50% of the Swedish volume of drug use, have been classified. Data for risk assessment were missing in 47% of AI. Among drugs with data 7% had a PEC/PNEC ratio >1, and another 7% had a ratio between 0.1 and 1. The AIs with highest ratio (>10) were two estrogens. Data for hazard assessment were lacking in 16% of the AI. Among drugs with environmental data 92% were not ready biodegradable, 23% had potential to bioaccumulation, and 61% were toxic to aquatic organisms at a concentration below 1 mg/l. These data are utilized by regional pharmaceutical expert groups when selecting substances to be recommended in public health care in Sweden. They may also be used by prescribing doctors who want to identify the environmentally most favourable substance among several with equivalent medical effect. We conclude that environmental data on human medicinal products are often missing, or reveal unfavourable environmental properties. A proper judgement of the environmental impact of an AI requires a joint evaluation of its risk and hazard. We suggest that the pharmaceutical producers should highlight environmental precaution when designing new AIs, and that the environmental data should be transparent to the general public.

Histone deacetylase inhibitors up-regulate LL-37 expression independent of toll-like receptor mediated signalling in airway epithelial cells.

PubMed

Liu, Quan; Liu, Juan; Roschmann, Kristina Irene Lisolette; van Egmond, Danielle; Golebski, Korneliusz; Fokkens, Wytske Johanna; Wang, Dehui; van Drunen, Cornelis Maria

2013-04-11

HDAC inhibitors have been proposed as anticancer agents. However, their roles in innate genes expression remain not well known. Cathelicidin LL-37 is one of the few human bactericidal peptides, but the regulation of histone acetylation on LL-37 expression in airway epithelium remains largely unknown. Therefore, we investigated the effects of two non-selective HDACi, trichostatin A (TSA) and sodium butyrate (SB), on the expression of the cathelicidin LL-37 in human airway epithelial cells. LL37 in human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells(PNEC) in response to HDAC inhibitors with or without poly (I:C) stimulation was assessed using real-time PCR and western blot. In parallel, IL-6 expression was evaluated by ELISA. Our results showed that HDAC inhibitors up-regulated LL-37 gene expression independent of poly (I:C) stimulation in PNEC as well as in NCI-H292 cells. HDAC inhibitors increased LL37 protein expression in NCI-H292 cells but not in PNEC. In addition, HDAC inhibitors significantly inhibited poly (I:C)-induced IL-6 production in both of the epithelial cells. In conclusion, HDAC inhibitors directly up-regulated LL-37 gene expression in human airway epithelial cells.

Histone deacetylase inhibitors up-regulate LL-37 expression independent of toll-like receptor mediated signalling in airway epithelial cells

PubMed Central

2013-01-01

HDAC inhibitors have been proposed as anticancer agents. However, their roles in innate genes expression remain not well known. Cathelicidin LL-37 is one of the few human bactericidal peptides, but the regulation of histone acetylation on LL-37 expression in airway epithelium remains largely unknown. Therefore, we investigated the effects of two non-selective HDACi, trichostatin A (TSA) and sodium butyrate (SB), on the expression of the cathelicidin LL-37 in human airway epithelial cells. LL37 in human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells(PNEC) in response to HDAC inhibitors with or without poly (I:C) stimulation was assessed using real-time PCR and western blot. In parallel, IL-6 expression was evaluated by ELISA. Our results showed that HDAC inhibitors up-regulated LL-37 gene expression independent of poly (I:C) stimulation in PNEC as well as in NCI-H292 cells. HDAC inhibitors increased LL37 protein expression in NCI-H292 cells but not in PNEC. In addition, HDAC inhibitors significantly inhibited poly (I:C)-induced IL-6 production in both of the epithelial cells. In conclusion, HDAC inhibitors directly up-regulated LL-37 gene expression in human airway epithelial cells. PMID:23577829

Acute Toxicity and Ecological Risk Assessment of Benzophenone and N,N-Diethyl-3 Methylbenzamide in Personal Care Products.

PubMed

Sun, Hong-Qin; Du, Yang; Zhang, Zi-Yang; Jiang, Wen-Jing; Guo, Yan-Min; Lu, Xi-Wu; Zhang, Yi-Min; Sun, Li-Wei

2016-09-19

Benzophenone (BP) and N,N -diethyl-3-methylbenzamide (DEET) are two chemicals often used in personal care products (PCPs). There is a lack of systematic ecotoxicological evaluations about the two chemicals to aquatic organisms. In the present study, the acute toxic effects on Chlorella vulgaris , Daphnia Magana , and Brachydanio rerio were tested and the ecotoxicological risks were evaluated. For BP, the 96-h half-maximal effective concentration (EC 50 ) on C. vulgaris was 6.86 mg/L; the 24-h median lethal concentration (LC 50 ) on D. magana was 7.63 mg/L; the 96-h LC 50 on B. rerio was 14.73 mg/L. For DEET, those were 270.72 mg/L, 40.74 mg/L, and 109.67 mg/L, respectively. The mixture toxicity of BP and DEET, on C. vulgaris , D. magana , and B. rerio all showed an additive effect. The induced predicted no-effect concentrations (PNECs) for BP and DEET by assessment factor (AF) method are 0.003 mg/L and 0.407 mg/L, respectively. Both are lower than the concentrations detected from environment at present, verifying that BP and DEET are low-risk chemicals to the environment.

Acute Toxicity and Ecological Risk Assessment of Benzophenone and N,N-Diethyl-3 Methylbenzamide in Personal Care Products

PubMed Central

Sun, Hong-Qin; Du, Yang; Zhang, Zi-Yang; Jiang, Wen-Jing; Guo, Yan-Min; Lu, Xi-Wu; Zhang, Yi-Min; Sun, Li-Wei

2016-01-01

Benzophenone (BP) and N,N-diethyl-3-methylbenzamide (DEET) are two chemicals often used in personal care products (PCPs). There is a lack of systematic ecotoxicological evaluations about the two chemicals to aquatic organisms. In the present study, the acute toxic effects on Chlorella vulgaris, Daphnia Magana, and Brachydanio rerio were tested and the ecotoxicological risks were evaluated. For BP, the 96-h half-maximal effective concentration (EC50) on C. vulgaris was 6.86 mg/L; the 24-h median lethal concentration (LC50) on D. magana was 7.63 mg/L; the 96-h LC50 on B. rerio was 14.73 mg/L. For DEET, those were 270.72 mg/L, 40.74 mg/L, and 109.67 mg/L, respectively. The mixture toxicity of BP and DEET, on C. vulgaris, D. magana, and B. rerio all showed an additive effect. The induced predicted no-effect concentrations (PNECs) for BP and DEET by assessment factor (AF) method are 0.003 mg/L and 0.407 mg/L, respectively. Both are lower than the concentrations detected from environment at present, verifying that BP and DEET are low-risk chemicals to the environment. PMID:27657095

Chemical Chaperone of Endoplasmic Reticulum Stress Inhibits Epithelial-Mesenchymal Transition Induced by TGF-β1 in Airway Epithelium via the c-Src Pathway

PubMed Central

Lee, Heung-Man; Kang, Ju-Hyung; Shin, Jae-Min; Lee, Seoung-Ae

2017-01-01

Epithelial-mesenchymal transition (EMT) is a biological process that allows epithelial cells to assume a mesenchymal cell phenotype. EMT is considered as a therapeutic target for several persistent inflammatory airway diseases related to tissue remodeling. Herein, we investigated the role of endoplasmic reticulum (ER) stress and c-Src in TGF-β1-induced EMT. A549 cells, primary nasal epithelial cells (PNECs), and inferior nasal turbinate organ cultures were exposed to 4-phenylbutylic acid (4PBA) or PP2 and then stimulated with TGF-β1. We found that E-cadherin, vimentin, fibronectin, and α-SMA expression was increased in nasal polyps compared to inferior turbinates. TGF-β1 increased the expression of EMT markers such as E-cadherin, fibronectin, vimentin, and α-SMA and ER stress markers (XBP-1s and GRP78), an effect that was blocked by PBA or PP2 treatment. 4-PBA and PP2 also blocked the effect of TGF-β1 on migration of A549 cells and suppressed TGF-β1-induced expression of EMT markers in PNECs and organ cultures of inferior turbinate. In conclusion, we demonstrated that 4PBA inhibits TGF-β1-induced EMT via the c-Src pathway in A549 cells, PNECs, and inferior turbinate organ cultures. These results suggest an important role for ER stress and a diverse role for TGF-β1 in upper airway chronic inflammatory disease such as CRS. PMID:28804222

Chemical Chaperone of Endoplasmic Reticulum Stress Inhibits Epithelial-Mesenchymal Transition Induced by TGF-β1 in Airway Epithelium via the c-Src Pathway.

PubMed

Lee, Heung-Man; Kang, Ju-Hyung; Shin, Jae-Min; Lee, Seoung-Ae; Park, Il-Ho

2017-01-01

Epithelial-mesenchymal transition (EMT) is a biological process that allows epithelial cells to assume a mesenchymal cell phenotype. EMT is considered as a therapeutic target for several persistent inflammatory airway diseases related to tissue remodeling. Herein, we investigated the role of endoplasmic reticulum (ER) stress and c-Src in TGF- β 1-induced EMT. A549 cells, primary nasal epithelial cells (PNECs), and inferior nasal turbinate organ cultures were exposed to 4-phenylbutylic acid (4PBA) or PP2 and then stimulated with TGF- β 1. We found that E-cadherin, vimentin, fibronectin, and α -SMA expression was increased in nasal polyps compared to inferior turbinates. TGF- β 1 increased the expression of EMT markers such as E-cadherin, fibronectin, vimentin, and α -SMA and ER stress markers (XBP-1s and GRP78), an effect that was blocked by PBA or PP2 treatment. 4-PBA and PP2 also blocked the effect of TGF- β 1 on migration of A549 cells and suppressed TGF- β 1-induced expression of EMT markers in PNECs and organ cultures of inferior turbinate. In conclusion, we demonstrated that 4PBA inhibits TGF- β 1-induced EMT via the c-Src pathway in A549 cells, PNECs, and inferior turbinate organ cultures. These results suggest an important role for ER stress and a diverse role for TGF- β 1 in upper airway chronic inflammatory disease such as CRS.

Global review and analysis of erythromycin in the environment: Occurrence, bioaccumulation and antibiotic resistance hazards.

PubMed

Schafhauser, Bruno Henrique; Kristofco, Lauren A; de Oliveira, Cíntia Mara Ribas; Brooks, Bryan W

2018-07-01

Environmental observations of antibiotics and other pharmaceuticals have received attention as indicators of an urbanizing global water cycle. When connections between environment and development of antibiotic resistance (ABR) are considered, it is increasingly important to understand the life cycle of antibiotics. Here we examined the global occurrence of erythromycin (ERY) in: 1. wastewater effluent, inland waters, drinking water, groundwater, and estuarine and coastal systems; 2. sewage sludge, biosolids and sediments; and 3. tissues of aquatic organisms. We then performed probabilistic environmental hazard assessments to identify probabilities of exceeding the predicted no-effect concentration (PNEC) of 1.0 μg L -1 for promoting ABR, based on previous modeling of minimum inhibitory concentrations and minimal selective concentrations of ERY, and measured levels from different geographic regions. Marked differences were observed among geographic regions and matrices. For example, more information was available for water matrices (312 publications) than solids (97 publications). ERY has primarily been studied in Asia, North America and Europe with the majority of studies performed in China, USA, Spain and the United Kingdom. In surface waters 72.4% of the Asian studies have been performed in China, while 85.4% of the observations from North America were from the USA; Spain represented 41.9% of the European surface water studies. Remarkably, results from PEHAs indicated that the likelihood of exceeding the ERY PNEC for ABR in effluents was markedly high in Asia (33.3%) followed by Europe (20%) and North America (17.8%). Unfortunately, ERY occurrence data is comparatively limited in coastal and marine systems across large geographic regions including Southwest Asia, Eastern Europe, Africa, and Central and South America. Future studies are needed to understand risks of ERY and other antibiotics to human health and the environment, particularly in developing regions where waste management systems and treatment infrastructure are being implemented slower than access to and consumption of pharmaceuticals is occurring. Copyright © 2018 Elsevier Ltd. All rights reserved.

Select antibiotics in leachate from closed and active landfills exceed thresholds for antibiotic resistance development.

PubMed

Chung, S S; Zheng, J S; Burket, S R; Brooks, B W

2018-06-01

Though antibiotic resistance (ABR) represents a major global health threat, contributions of landfill leachate to the life cycle of antibiotics and ABR development are poorly understood in rapidly urbanizing regions of developing countries. We selected one of the largest active landfills in Asia and two landfills that have been closed for 20 years to examine antibiotic occurrences in leachates and associated hazards during wet and dry season sampling events. We focused on some of the most commonly used human antibiotics in Hong Kong, one of the most populous Asian cities and the fourth most densely populated cities in the world. Seven antibiotics (cephalexin [CLX], chloramphenicol [CAP], ciprofloxacin [CIP], erythromycin [ERY], roxithromycin [ROX], trimethoprim [TMP], sulfamethoxazole [SMX]) were quantitated using HPLC-MS/MS generally following previously reported methods. Whereas CLX, CAP, ROX and SMX in leachates did not exceed ABR predicted no effect concentrations (PNECs), exceedances were observed for CIP, ERY and TMP in some study locations and on some dates. In fact, an ABR PNEC for CIP was exceeded in leachates during both sampling periods from all study locations, including leachates that are directly discharged to coastal systems. These findings highlight the importance of developing an advanced understanding of pharmaceutical access, usage and disposal practices, effectiveness of intervention strategies (e.g., leachate treatment technologies, drug take-back schemes), and contributions of landfill leachates to the life cycle of antibiotics and ABR development, particularly in rapidly urbanizing coastal regions with less advanced waste management systems than Hong Kong. Copyright © 2018 Elsevier Ltd. All rights reserved.

Environmental Risk Assessment of Pharmaceutical Mixtures: Demands, Gaps, and Possible Bridges.

PubMed

Backhaus, Thomas

2016-07-01

The ecotoxicological risk of pharmaceutical mixtures typically exceeds the risk of each individual compound, which calls specific attention to the fact that monitoring surveys routinely find complex pharmaceutical mixtures in various environmental compartments. However, although the body of evidence on the ecotoxicology of pharmaceutical mixtures is quite consistent, the current guidelines for the environmental risk assessment of pharmaceuticals often do not explicitly address mixture effects. Data availability and acceptable methods often limit such assessments. A tiered approach that begins with summing up individual risk quotients, i.e., the ratio between the predicted or measured environmental concentration and the predicted no effect concentration (PNEC) is therefore suggested in this paper, in order to improve the realism of the environmental risk assessment of pharmaceuticals. Additionally, the use of a mixture-specific assessment factor, as well as the classical mixture toxicity concepts of concentration addition and independent action is explored. Finally, specific attention is given to the exposure-based waiving of environmental risk assessments, as currently implemented in screening or pre-screening phases (tier 0 in Europe, categorical exclusion in the USA), since even low, individually non-toxic concentrations might combine to produce substantial mixture effects.

Diesel Exhaust Particles Enhance MUC4 Expression in NCI-H292 Cells and Nasal Epithelial Cells via the p38/CREB Pathway.

PubMed

Park, Il-Ho; Kang, Ju-Hyung; Kim, Jin Ah; Shin, Jae-Min; Lee, Heung-Man

2016-01-01

Diesel exhaust particles (DEPs), the major contributors to air pollution, induce inflammatory responses in the nasal epithelium. Overproduction of airway mucins is an important pathogenic finding in inflammatory airway diseases. The aims of the present study were to determine the effect of DEPs on the expression of the mucin gene MUC4 and to investigate the underlying mechanism of DEP-induced MUC4 expression in NCI-H292 cells and primary nasal epithelial cells (PNECs). NCI-H292 cells were stimulated for 24 h with DEPs. Messenger RNA (mRNA) and protein expression of MUC4 was determined by real-time reverse transcription (RT) polymerase chain reaction (PCR) and Western blotting. NCI-H292 cells were exposed to 3 mitogen-activated protein kinase inhibitors (U0126, SB203580, and SP600125) and a CREB (cAMP response element-binding protein) inhibitor prior to stimulation with DEPs, and MUC4 expression was examined by RT-PCR and Western blotting. PNECs were pretreated with a p38 inhibitor and CREB inhibitor prior to stimulation with DEPs, and MUC4 expression was then determined by RT-PCR and/or Western blotting. DEPs significantly increased the expression of MUC4 mRNA and protein. MUC4 mRNA and protein expression was inhibited by pretreatment with p38 and CREB inhibitors in NCI-H292 stimulated with DEPs. p38 and CREB inhibitors also blocked the expression of MUC4 mRNA and protein in DEP-stimulated PNECs. We demonstrated that DEPs stimulated the expression of MUC4 via the p38/CREB pathway in NCI-H292 cells and PNECs. The results of the present study pave the way for further studies on the role of MUC4 in DEP-induced hypersecretion in airway epithelium. © 2017 S. Karger AG, Basel.

Mixture toxicity in the marine environment: Model development and evidence for synergism at environmental concentrations.

PubMed

Deruytter, David; Baert, Jan M; Nevejan, Nancy; De Schamphelaere, Karel A C; Janssen, Colin R

2017-12-01

Little is known about the effect of metal mixtures on marine organisms, especially after exposure to environmentally realistic concentrations. This information is, however, required to evaluate the need to include mixtures in future environmental risk assessment procedures. We assessed the effect of copper (Cu)-Nickel (Ni) binary mixtures on Mytilus edulis larval development using a full factorial design that included environmentally relevant metal concentrations and ratios. The reproducibility of the results was assessed by repeating this experiment 5 times. The observed mixture effects were compared with the effects predicted with the concentration addition model. Deviations from the concentration addition model were estimated using a Markov chain Monte-Carlo algorithm. This enabled the accurate estimation of the deviations and their uncertainty. The results demonstrated reproducibly that the type of interaction-synergism or antagonism-mainly depended on the Ni concentration. Antagonism was observed at high Ni concentrations, whereas synergism occurred at Ni concentrations as low as 4.9 μg Ni/L. This low (and realistic) Ni concentration was 1% of the median effective concentration (EC50) of Ni or 57% of the Ni predicted-no-effect concentration (PNEC) in the European Union environmental risk assessment. It is concluded that results from mixture studies should not be extrapolated to concentrations or ratios other than those investigated and that significant mixture interactions can occur at environmentally realistic concentrations. This should be accounted for in (marine) environmental risk assessment of metals. Environ Toxicol Chem 2017;36:3471-3479. © 2017 SETAC. © 2017 SETAC.

Acute Toxicity of the Antifouling Compound Butenolide in Non-Target Organisms

PubMed Central

Chandramouli, Kondethimmanahalli H.; Xu, Ying; Pan, Ke; Wang, Wen-Xiong; Qian, Pei-Yuan

2011-01-01

Butenolide [5-octylfuran-2(5H)-one] is a recently discovered and very promising anti-marine-fouling compound. In this study, the acute toxicity of butenolide was assessed in several non-target organisms, including micro algae, crustaceans, and fish. Results were compared with previously reported results on the effective concentrations used on fouling (target) organisms. According to OECD's guideline, the predicted no effect concentration (PNEC) was 0.168 µg l−1, which was among one of the highest in representative new biocides. Mechanistically, the phenotype of butenolide-treated Danio rerio (zebrafish) embryos was similar to the phenotype of the pro-caspase-3 over-expression mutant with pericardial edema, small eyes, small brains, and increased numbers of apoptotic cells in the bodies of zebrafish embryos. Butenolide also induced apoptosis in HeLa cells, with the activation of c-Jun N-terminal kinases (JNK), Bcl-2 family proteins, and caspases and proteasomes/lysosomes involved in this process. This is the first detailed toxicity and toxicology study on this antifouling compound. PMID:21897857

Derivation of Soil Ecological Criteria for Copper in Chinese Soils

PubMed Central

Wang, Xiaoqing; Wei, Dongpu; Ma, Yibing; McLaughlin, Mike J.

2015-01-01

Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database. Second, the compiled data were corrected with leaching and aging factors to minimize the differences between laboratory and field conditions. Before Cu ecotoxicity data were entered into a species sensitivity distribution (SSD), they were normalized with Cu ecotoxicity predictive models to modify the effects of soil properties on Cu ecotoxicity. The PNEC value was set equal to the hazardous concentration for x% of the species (HCx), which could be calculated from the SSD curves, without an additional assessment factor. Finally, predictive models for HCx based on soil properties were developed. The soil properties had a significant effect on the magnitude of HCx, with HC5 varying from 13.1 mg/kg in acidic soils to 51.9 mg/kg in alkaline non-calcareous soils. The two-factor predictive models based on soil pH and cation exchange capacity could predict HCx with determination coefficients (R2) of 0.82–0.91. The three-factor predictive models – that took into account the effect of soil organic carbon – were more accurate than two-factor models, with R2 of 0.85–0.99. The predictive models obtained here could be used to calculate soil-specific criteria. All results obtained here could provide a scientific basis for revision of current Chinese soil environmental quality standards, and the approach adopted in this study could be used as a pragmatic framework for developing soil ecological criteria for other trace elements in soils. PMID:26207783

Effects of antibacterial agents, levofloxacin and clarithromycin, on aquatic organisms.

PubMed

Yamashita, N; Yasojima, M; Nakada, N; Miyajima, K; Komori, K; Suzuki, Y; Tanaka, H

2006-01-01

Contamination of surface waters by pharmaceutical chemicals is an emerging environmental problem. This study evaluated the toxic effects of the antibacterial agents levofloxacin (LVFX) and clarithromycin (CAM), which are widely used in Japan, on aquatic organisms. Ecotoxicity tests using a bacterium, alga and crustacean were conducted. Microtox test using a marine fluorescent bacterium showed that LVFX and CAM have no acute toxicity to the bacterium. From the results of the Daphnia immobilisation test, LVFX and CAM did not show acute toxicity to the crustacean. Meanwhile, an algal growth inhibition test revealed that LVFX and CAM have high toxicity to the microalga. The phytotoxicity of CAM was about 100-fold higher than that of LVFX from a comparison of EC50 (median effective concentration) value. From the Daphnia reproduction test, LVFX and CAM also showed chronic toxicity to the crustacean. Concentrations of LVFX and CAM in the aquatic environment were compared with PNEC (predicted no effect concentration) to evaluate the ecological risk. As a result, the ecological risk of LVFX is considered to be low, but that of CAM is higher, suggesting that CAM discharged into an aquatic environment after therapeutic use may affect organisms in the aquatic environment.

Popular pharmaceutical residues in hospital wastewater: quantification and qualification of degradation products by mass spectroscopy after treatment with membrane bioreactor.

PubMed

Chiarello, M; Minetto, L; Giustina, S V Della; Beal, L L; Moura, S

2016-08-01

The occurrence of drugs in wastewater has been considered an imminent risk to the population, for the treatments used are usually ineffective. The presence of four popular drug residues (metformin, paracetamol, tetracycline, and enalapril) in hospital effluents, by using ultra-fast liquid chromatography tandem mass spectrometry (UFLC-MS/MS) with electrospray (ESI) ionization, and removal/degradation by membrane bioreactor (MBR) system are investigated in this study. For analysis method, all standard calibration curves showed satisfactory linearity (R (2) ≥ 0.993) within a relatively wide range. The recovery was between 70.4 and 105.0 %, and the relative standard deviation (RSD) values were within the ranges of 8.2 and 13.5 %. The effluent samples were collected at the end of the process treated in a bench-scale MBR treatment system and preconcentrated on solid-phase extraction (SPE) cartridges. Following that procedure, the chemical analysis demonstrated that the MBR system was effective in enalapril 94.3 ± 7.63 %, tetracycline 99.4 ± 0.02 %, and paracetamol 98.8 ± 0.86 % removal. However, the polar metformin was less effectively removed (35.4 ± 12.49 %). Moreover, the degradation products were investigated using high-resolution mass spectrometry (HRMS) by quadrupole-time of flight (Q-TOF), which has been indicated a tetracycline metabolite. In order to investigate the environmental impact, the wastewater potential risk was evaluated. The risk quotient (RQ) by measure environmental concentration (MEC) and its predicted no effect concentration (PNEC) ratio (RQ = MEC/PNEC) was between 0.003 (enalapril) to 0.815 (paracetamol). Finally, this work demonstrates that UFLC-MS/MS (ESI-Q) is a sensitive and selective method for drug analysis in wastewater and with ESI-Q-TOF has the accuracy required for determining the degradation products of these compounds. Also, it indicated that membrane bioreactor systems represent a new generation of processes that have proved to outperform conventional treatment showing better effluent quality. The removal capacity studied in this work demonstrates the efficiency of this process.

Endocrine disruptors in freshwater streams of Hesse, Germany: changes in concentration levels in the time span from 2003 to 2005.

PubMed

Quednow, Kristin; Püttmann, Wilhelm

2008-03-01

Four small freshwater streams in the region known as Hessisches Ried in Germany were investigated with respect to the temporal and spatial concentration variations of the endocrine disruptors bisphenol A (BPA), 4-tert-octylphenol (4-tert-OP), and the technical isomer mixture of 4-nonylphenol (tech.-4-NP). Measured concentrations of the target compounds in the river water samples ranged from <20 ng/l to 1927 ng/l, <10 ng/l to 770 ng/l, and <10 ng/l to 420 ng/l for BPA, 4-tert-OP and tech.-4-NP, respectively. BPA levels were, with the exception of two samples, below the predicted no-effect concentration (PNEC) for water organisms. Tech.-4-NP concentrations showed a significant tendency of decreasing concentrations during the sampling period. This is mainly attributed to the implementation of the European Directive 2003/53/EG, which restricts both the marketing and use of nonylphenols. Results from the analysis of additionally collected water samples from sewage treatment plant (STP) effluents indicate that the STPs cannot be the only sources for tech.-4-NP found in the river water.

Environmental and human risk hierarchy of pesticides: A prioritization method, based on monitoring, hazard assessment and environmental fate.

PubMed

Tsaboula, Aggeliki; Papadakis, Emmanouil-Nikolaos; Vryzas, Zisis; Kotopoulou, Athina; Kintzikoglou, Katerina; Papadopoulou-Mourkidou, Euphemia

2016-05-01

A pesticide prioritization approach was developed and implemented in the Pinios River Basin of Central Greece. It takes under consideration the Level of Environmental Risk containing information on the frequency of occurrence of pesticides above environmental thresholds, the intensity of this occurrence and the spatial distribution as well as information about the fate and behavior of pesticides in the environment and the potential to have adverse impact on humans' health. Original 3-year monitoring data from 102 Stationary Sampling Sites located on rivers and their tributaries, reservoirs, streams and irrigation/drainage canals giving rise to a collection of 2382 water samples resulting in 7088 data sets, were included in this integrated prioritization study. Among 302 monitored active ingredients, 119 were detected at least once and the concentrations found in the aquatic systems for 41% of compounds were higher than the respective lowest Predicted Non-Effect Concentration (PNEC) values. Sixteen and 5 pesticides were found with risk ratios (MECmax/PNEC) above 10 (high concern) and 100 (very high concern), respectively. However, pesticides with maximum Measured Environmental Concentration (MECmax) values exceeding by 1000 times the respective lowest PNEC values were also found which were considered of extremely high concern; in the latter group were included prometryn, chlorpyrifos, diazinon, λ-cyhalothrin, cypermethrin, α-cypermethrin deltamethrin, ethalfluralin and phosmet. The sensitivity of the analytical methods used in the monitoring study was considered inadequate to meet the toxicological endpoints for 32 pesticides. The widest distribution of occurrence in the Stationary Sampling Sites of the monitoring program was found for the pesticides, prometryn, fluometuron, terbuthylazine, S-metolachlor, chlorpyrifos, diphenylamine, acetochlor, alachlor, 2,4-D, etridiazole, imidacloprid and lindane (γ-ΗCH). Among the 27 priority pesticides included in the Directive 2013/39/EU, in the present study 13 pesticides were considered as candidates for River Basin Specific Pollutants (RBSP) for the River Basin of Pinios. Among the 30 pesticide specific pollutants that were established by the Greek authorities, in the present study only 6 were considered as candidates for RBSP for the river basin of Pinios. As a result of the implementation of the prioritization approach developed in this study a total of 71 pesticides were identified as being RBSP for the river basin of Pinios. The higher Level of Environmental Risk was found to be exerted by the organophosphorus insecticide chlorpyrifos, followed by lindane and prometryn. The present study provides background information for important decisions to be made concerning the selection of pesticides which should be included in the target analyte list of new monitoring and screening programs of surface water quality in the Pinios River Basin. In addition, the prioritization approach proposed here can be useful for the development of River Basin Management Plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Occurrence of immunosuppressive drugs and their metabolites in the sewage-impacted Vistula and Utrata Rivers and in tap water from the Warsaw region (Poland).

PubMed

Giebułtowicz, Joanna; Nałęcz-Jawecki, Grzegorz

2016-04-01

Immunosuppresive therapy following organ transplant frequently includes treatment with tacrolimus and mycophenolic acid derivatives. These pharmaceuticals may enter the environment through wastewater treatment plant (WWTP) effluents and may have a potentially harmful effect on aquatic biota. Tacrolimus, mycophenolic acid and their metabolites were measured at specific points of a large Polish river (Vistula), a smaller river (Utrata) and in tap water samples from the Warsaw region. Analysis was performed using liquid chromatography tandem mass spectrometry, after solid phase extraction for water samples, or QuEChERS extraction for sediments. Residues of tacrolimus were below quantitation limits in both water and sediment samples. However, in water samples mycophenolic acid concentrations were measured at up to 180 ng L(-1) downstream of WWTP outfalls. No immunosuppressive drugs were detected in tap water. Concentrations of mycophenolic acid exceeded the predicted no effect concentration (PNEC) value in some Polish surface water, and risk calculations predicted at least twice higher concentrations in some other countries of the European Union. To the best of the authors' knowledge, this is the first report of these immunosuppressive drug concentrations in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Contribution for the Derivation of a Soil Screening Value (SSV) for Uranium, Using a Natural Reference Soil

PubMed Central

Caetano, Ana Luisa; Marques, Catarina R.; Gavina, Ana; Carvalho, Fernando; Gonçalves, Fernando; da Silva, Eduardo Ferreira; Pereira, Ruth

2014-01-01

In order to regulate the management of contaminated land, many countries have been deriving soil screening values (SSV). However, the ecotoxicological data available for uranium is still insufficient and incapable to generate SSVs for European soils. In this sense, and so as to make up for this shortcoming, a battery of ecotoxicological assays focusing on soil functions and organisms, and a wide range of endpoints was carried out, using a natural soil artificially spiked with uranium. In terrestrial ecotoxicology, it is widely recognized that soils have different properties that can influence the bioavailability and the toxicity of chemicals. In this context, SSVs derived for artificial soils or for other types of natural soils, may lead to unfeasible environmental risk assessment. Hence, the use of natural regional representative soils is of great importance in the derivation of SSVs. A Portuguese natural reference soil PTRS1, from a granitic region, was thereby applied as test substrate. This study allowed the determination of NOEC, LOEC, EC20 and EC50 values for uranium. Dehydrogenase and urease enzymes displayed the lowest values (34.9 and <134.5 mg U Kg, respectively). Eisenia andrei and Enchytraeus crypticus revealed to be more sensitive to uranium than Folsomia candida. EC50 values of 631.00, 518.65 and 851.64 mg U Kg were recorded for the three species, respectively. Concerning plants, only Lactuca sativa was affected by U at concentrations up to 1000 mg U kg1. The outcomes of the study may in part be constrained by physical and chemical characteristics of soils, hence contributing to the discrepancy between the toxicity data generated in this study and that available in the literature. Following the assessment factor method, a predicted no effect concentration (PNEC) value of 15.5 mg kg−1 dw was obtained for U. This PNEC value is proposed as a SSV for soils similar to the PTRS1. PMID:25353962

Macrocyclic fragrance materials--a screening-level environmental assessment using chemical categorization.

PubMed

Salvito, Daniel; Lapczynski, Aurelia; Sachse-Vasquez, Christen; McIntosh, Colin; Calow, Peter; Greim, Helmut; Escher, Beate

2011-09-01

A screening-level aquatic environmental risk assessment for macrocyclic fragrance materials using a "group approach" is presented using data for 30 macrocyclic fragrance ingredients. In this group approach, conservative estimates of environmental exposure and ecotoxicological effects thresholds for compounds within two subgroups (15 macrocyclic ketones and 15 macrocyclic lactones/lactides) were used to estimate the aquatic ecological risk potential for these subgroups. It is reasonable to separate these fragrance materials into the two subgroups based on the likely metabolic pathway required for biodegradation and on expected different ecotoxicological modes of action. The current volumes of use for the macrocyclic ketones in both Europe and North America ranges from <1 (low kg quantities) to no greater than 50 metric tonnes in either region and for macrocyclic lactones/lactides the volume of use range for both regions is <1 to no greater than 1000 metric tonnes in any one region. Based on these regional tonnages, biodegradability of these two subgroups of materials, and minimal in stream dilution (3:1), the conservatively predicted exposure concentrations for macrocyclic ketones would range from <0.01 to 0.05 μg/L in Europe and from <0.01 to 0.03 μg/L in North America. For macrocyclic lactones/lactides, the concentration within the mixing zone would range from <0.01 to 0.7 μg/L in Europe and from <0.01 to 1.0 μg/L in North America. The PNECs derived for the macrocyclic ketones is 0.22 μg/L and for macrocyclic lactones/lactides is 2.7 μg/L. The results of this screening-level aquatic ecological risk assessment indicate that at their current tonnage, often referred to as volumes of use, macrocyclic fragrance materials in Europe and North America, pose a negligible risk to aquatic biota; with no PEC/PNEC ratio exceeding 1 for any material in any subgroup. Copyright © 2011 Elsevier Inc. All rights reserved.

Approach on environmental risk assessment of nanosilver released from textiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voelker, Doris, E-mail: doris.voelker@uba.de; Schlich, Karsten; Hohndorf, Lars

2015-07-15

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related tomore » PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly introduce AgNM into the textile fiber since this will strongly minimize the release of AgNM during washing. If this is not possible due to technical limitations or other reasons, the introduction of a threshold level controlling the release of AgNM from textiles is suggested. It has to be noted that this study is a case study which is only valid for the investigated NM-300K and its potential application in textiles. - Highlights: • Washing: release rates of AgNM depend on furnishing in textiles. • Calculated PNECs for the aquatic compartment were low. • For the chosen scenarios no environmental risk of AgNM from textiles was observed. • AgNM is retained in sewage sludge. • In WWTP most of the silver adsorbs to sewage sludge and thus, may reach farmland.« less

Assessment of the environmental fate and effects of azilsartan, a selective antagonist of angiotensin II type 1.

PubMed

Weltman, R; Brands, C M J; Corral, E; Desmares-Koopmans, M J E; Migchielsen, M H J; Oudhoff, K A; de Roode, D F

2012-06-01

In this paper the results of a thorough evaluation of the environmental fate and effects of azilsartan are presented. Azilsartan medoxomil is administered as a pro-drug for the treatment of patients with essential hypertension. The pro-drug is converted by hydrolysis to the active pharmaceutical ingredient azilsartan. Laboratory tests to evaluate the environmental fate and effects of azilsartan medoxomil were conducted with azilsartan and performed in accordance with OECD test guidelines. The predicted environmental concentration (PEC) in surface water was estimated at 0.32 μg L(-1) (above the action limit of 0.01 μg L(-1)), triggering a Phase II assessment. Azilsartan is not readily biodegradable. Results of the water sediment study demonstrated significant shifting of azilsartan metabolites to sediment. Based on the equilibrium partitioning method, metabolites are unlikely to pose a risk to sediment-dwelling organisms. Ratios of the predicted environmental concentrations (PECs) to the predicted-no-effect concentrations (PNECs) did not exceed the relevant triggers, and the risk to aquatic, sewage treatment plant (STP), groundwater and sediment compartments was concluded acceptable. A terrestrial assessment was not triggered. Azilsartan poses an acceptable risk to the environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Toxicity of the ionophore antibiotic lasalocid to soil-dwelling invertebrates: avoidance tests in comparison to classic sublethal tests.

PubMed

Žižek, Suzana; Zidar, Primož

2013-07-01

Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It enters the environment with the use of contaminated manure on agricultural land. Despite its extensive use, the effects of lasalocid on non-target soil organisms are poorly explored. We used classical subleathal ecotoxicity tests to assess the effects of lasalocid on earthworms (Eisenia andrei) and isopods (Porcellio scaber) and compared the results with tests using avoidance behaviour as the endpoint. The results showed that avoidance is a much more sensitive endpoint. For earthworms, EC50 for avoidance (12.3 mg kg(-1) dry soil) was more than five times lower than EC50 for reproduction (69.6 mg kg(-1) dry soil). In isopods the sensitivity of the behavioural response test was even higher. While the highest lasalocid concentration 202 mg kg(-1) had no significant effects on isopod growth or survival, already the lowest used concentration in the behavioural assay (4.51 mg kg(-1)) caused significant impact on isopod behaviour. Using the avoidance test results for calculating the predicted no-effect concentration (PNEC) of lasalocid to soil invertebrates, the value is close to the predicted environmental concentration (PEC). This indicates that the use of lasalocid-contaminated manure could potentially impair the habitat function of agricultural soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Distribution of perfluorooctane sulfonate and other perfluorochemicals in the ambient environment around a manufacturing facility in China.

PubMed

Wang, Yawei; Fu, Jianjie; Wang, Thanh; Liang, Yong; Pan, Yuanyuan; Cai, Yaqi; Jiang, Guibin

2010-11-01

Perfluorinated compounds (PFCs) can be released to the surrounding environment during manufacturing and usage of PFC containing products, which are considered as main direct sources of PFCs in the environment. This study evaluates the release of perfluorooctane sulfonate (PFOS) and other PFCs to the ambient environment around a manufacturing plant. Among the nine PFCs analyzed, only PFOS, perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS) were found in dust, water, soil, and chicken eggs. Very high concentrations of PFOS and PFOA were found in dust from the production storage, raw material stock room, and sulfonation workshop in the manufacturing facility, with the highest value at 4962 μg/g (dry weight) for PFOS and 160 μg/g for PFOA. A decreasing trend of the three PFCs concentrations in soils, water, and chicken eggs with increasing distance from the plant was found, indicating the production site to be the primary source of PFCs in this region. Risk quotients (RQs) assessment for surface water >500 m away from the plant were less than unity. Risk assessment of PFOS using predicted no-effect concentration (PNEC, 3.23 ng/g on a logarithmic scale) indicated no immediate ecological risk of a reduction in offspring survival. PFOS concentrations in most egg samples did not exceed the benchmark concentration derived in setting a reference dose for noncancer health effects (0.025 μg/(kgxd)).

Occurrence and risk assessment of pharmaceutically active compounds in wastewater treatment plants. A case study: Seville city (Spain).

PubMed

Santos, J L; Aparicio, I; Alonso, E

2007-05-01

The occurrence of four anti-inflammatory drugs (diclofenac, ibuprofen, ketoprofen and naproxen), an antiepileptic drug (carbamazepine) and a nervous stimulant (caffeine) in influent and effluent samples from four wastewater treatment plants (WWTPs) in Seville was evaluated. Removal rates in the WWTPs and risk assessment of the pharmaceutically active compounds have been studied. Analytical determination was carried out by high performance liquid chromatography (HPLC) with diode array (DAD) and fluorescence (Fl) detectors after sample clean up and concentration by solid phase extraction. All pharmaceutically active compounds, except diclofenac, were detected not only in wastewater influents but also in wastewater effluents. Mean concentrations of caffeine, carbamazepine, ketoprofen and naproxen ranged between 0.28-11.44 microg l(-1) and 0.21-2.62 microg l(-1) in influent and effluent wastewater, respectively. Ibuprofen was present in the highest concentrations in the range 12.13-373.11 microg l(-1) and 0.78-48.24 microg l(-1) in influent and effluent wastewater, respectively. Removal rates of the pharmaceuticals ranged between 6 and 98%. Risk quotients, expressed as ratios between the measured environmental concentration (MEC) and the predicted no effect concentrations (PNEC) were higher than 1 for ibuprofen and naproxen in influent wastewater and for ibuprofen in effluent wastewater.

Risk screening of pharmaceutical compounds in Romanian aquatic environment.

PubMed

Gheorghe, Stefania; Petre, Jana; Lucaciu, Irina; Stoica, Catalina; Nita-Lazar, Mihai

2016-06-01

The aquatic environment is under increased pressure by pharmaceutically active compounds (PhACs) due to anthropogenic activities. In spite of being found at very low concentrations (ng/L to μg/L) in the environment, PhACs represent a real danger to aquatic ecosystems due to their bioaccumulation and long-term effects. In this study, the presence in the aquatic environment of six non-steroidal anti-inflammatory drugs (ibuprofen, diclofenac, acetaminophen, naproxen, indomethacin, and ketoprofen), caffeine, and carbamazepine were monitored. Moreover, their aquatic risk and ecotoxicity by three biological models were evaluated. The monitoring studies performed in Romania showed that all studied PhACs were naturally present at concentrations >0.01 μg/L, pointing out the necessity to perform further toxicity tests for environmental risk assessment. The toxicity studies were carried out on aquatic organisms or bacteria and they indicated, for most of the tested PhACs, an insignificant or low toxicity effects: lethal concentrations (LC50) on fish Cyprinus carpio ranged from 42.60 mg/L to more than 100 mg/L; effective concentrations (EC50) on planktonic crustacean Daphnia magna ranged from 11.02 mg/L to more than 100 mg/L; inhibitory concentrations (IC50)/microbial toxic concentrations (MTC) on Vibrio fischeri and other bacterial strains ranged from 7.02 mg/L to more than 100 mg/L. The PhAC aquatic risk was assessed by using the ratio between measured environmental concentration (MEC) and predicted no effect concentration (PNEC) calculated for each type of organism. The average of quotient risks (RQs) revealed that the presence of these compounds in Romania's aquatic environment induced a lower or moderate aquatic risk.

A combined QSAR and partial order ranking approach to risk assessment.

PubMed

Carlsen, L

2006-04-01

QSAR generated data appear as an attractive alternative to experimental data as foreseen in the proposed new chemicals legislation REACH. A preliminary risk assessment for the aquatic environment can be based on few factors, i.e. the octanol-water partition coefficient (Kow), the vapour pressure (VP) and the potential biodegradability of the compound in combination with the predicted no-effect concentration (PNEC) and the actual tonnage in which the substance is produced. Application of partial order ranking, allowing simultaneous inclusion of several parameters leads to a mutual prioritisation of the investigated substances, the prioritisation possibly being further analysed through the concept of linear extensions and average ranks. The ranking uses endpoint values (log Kow and log VP) derived from strictly linear 'noise-deficient' QSAR models as input parameters. Biodegradation estimates were adopted from the BioWin module of the EPI Suite. The population growth impairment of Tetrahymena pyriformis was used as a surrogate for fish lethality.

A rational approach to selecting and ranking some pharmaceuticals of concern for the aquatic environment and their relative importance compared with other chemicals.

PubMed

Donnachie, Rachel L; Johnson, Andrew C; Sumpter, John P

2016-04-01

Aquatic organisms can be exposed to thousands of chemicals discharged by the human population. Many of these chemicals are considered disruptive to aquatic wildlife, and the literature on the impacts of these chemicals grows daily. However, because time and resources are not infinite, research must focus on the chemicals that represent the greatest threat. One group of chemicals of increasing concern is pharmaceuticals, for which the primary challenge is to identify which represent the greatest threat. In the present study, a list of 12 pharmaceuticals was compiled based on scoring the prevalence of different compounds from previous prioritization reviews. These included rankings based on prescription data, environmental concentrations, predicted environmental concentration/predicted no-effect concentration (PEC/PNEC) ratios, persistency/bioaccumulation/(eco)toxicity (PBT), and fish plasma model approaches. The most frequently cited were diclofenac, paracetamol, ibuprofen, carbamazepine, naproxen, atenolol, ethinyl estradiol, aspirin, fluoxetine, propranolol, metoprolol, and sulfamethoxazole. For each pharmaceutical, literature on effect concentrations was compiled and compared with river concentrations in the United Kingdom. The pharmaceuticals were ranked by degree of difference between the median effect and median river concentrations. Ethinyl estradiol was ranked as the highest concern, followed by fluoxetine, propranolol, and paracetamol. The relative risk of these pharmaceuticals was compared with those of metals and some persistent organic pollutants. Pharmaceuticals appear to be less of a threat to aquatic organisms than some metals (Cu, Al, Zn) and triclosan, using this ranking approach. © 2015 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

Occurrence of betablockers in effluents of wastewater treatment plants from the Lyon area (France) and risk assessment for the downstream rivers.

PubMed

Miège, Cécile; Favier, Maxime; Brosse, Corinne; Canler, Jean-Pierre; Coquery, Marina

2006-11-15

Five betablockers (oxprenolol, metoprolol, propranolol, bisoprolol, betaxolol) were analysed in effluents collected over a 3-month period from wastewater treatment plants (WTP) from the Lyon area in France. The analytical protocol consisted of solid phase extraction of the dissolved aqueous phase on HLB cartridges and analysis by gas chromatography coupled with mass detection (GC-MS) after derivatization. Concentrations of metoprolol, propranolol and bisoprolol varied from 45 to 2838ng/L whereas oxprenolol and betaxolol were never detected in these effluent samples. A high variability of betablockers concentrations and fluxes was observed between WTP effluents and within each WTP over the time period studied. Considering a flux per person for a dry weather period, Fontaine plant was pointed out as the less efficient WTP, which might be explained by its type of treatment (biological aerated filters). But we need additional analysis of effluent and influent waters to confirm this hypothesis. A tentative approach of local environmental risk assessment of propranolol based on the calculation of PEC/PNEC (predicted environmental concentration/predicted non effect concentration) ratio approach lead us to conclude on a negligible risk for the downstream rivers (Rhône river at Ternay and Saône river at Couzon Mt d'Or).

Seasonal variation of endocrine disrupting compounds, pharmaceuticals and personal care products in wastewater treatment plants.

PubMed

Yu, Yong; Wu, Laosheng; Chang, Andrew C

2013-01-01

The occurrence of 14 endocrine disrupting compounds (EDCs), pharmaceuticals and personal care products (PPCPs) in influents, effluents and sludge from five wastewater treatment plants (WWTPs) in southern California was studied in winter and summer. All 14 compounds were detected in influent samples from the five WWTPs except for estrone. Paracetamol, naproxen and ibuprofen were the dominant compounds, with mean concentrations of 41.7, 35.7 and 22.3 μg/L, respectively. The treatment removal efficiency for most compounds was more than 90% and concentrations in the effluents were relatively low. Seasonal variation of the compounds' concentration in the wastewater was significant: the total concentration of each compound in the wastewater was higher in winter than in summer, which is attributed to more human consumption of pharmaceuticals during winter and faster degradation of the compounds in summer. The highest concentrations of triclosan and octylphenol were detected in sewage sludge, with mean concentrations of 1505 and 1179 ng/g, respectively. Risk quotients (RQs), expressed as the ratios of environmental concentrations and the predicted no-effect concentrations (PNEC), were less than unity for all the compounds except for estrone in the effluents, indicating no immediate ecological risk is expected. However, RQs were higher than unity for 2 EDCs (estrone and octylphenol) and carbamazepine in sludge samples, indicating a significant ecotoxicological risk to human health. Therefore, appropriate treatment of sewage sludge is required before its application. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterisation of the ecotoxicity of hospital effluents: a review.

PubMed

Orias, Frédéric; Perrodin, Yves

2013-06-01

The multiple activities that take place in hospitals (surgery, drug treatments, radiology, cleaning of premises and linen, chemical and biological analysis laboratories, etc.), are a major source of pollutant emissions into the environment (disinfectants, detergents, drug residues, etc.). Most of these pollutants can be found in hospital effluents (HWW), then in urban sewer networks and WWTP (weakly adapted for their treatment) and finally in aquatic environments. In view to evaluating the impact of these pollutants on aquatic ecosystems, it is necessary to characterise their ecotoxicity. Several reviews have focused on the quantitative and qualitative characterisation of pollutants present in HWW. However, none have focused specifically on the characterisation of their experimental ecotoxicity. We have evaluated this according to two complementary approaches: (i) a "substance" approach based on the identification of the experimental data in the literature for different substances found in hospital effluents, and on the calculation of their PNEC (Predicted Non Effect Concentration), (ii) a "matrix" approach for which we have synthesised ecotoxicity data obtained from the hospital effluents directly. This work first highlights the diversity of the substances present within hospital effluents, and the very high ecotoxicity of some of them (minimum PNEC observed close to 0,01 pg/L). We also observed that the consumption of drugs in hospitals was a predominant factor chosen by authors to prioritise the compounds to be sought. Other criteria such as biodegradability, excretion rate and the bioaccumulability of pollutants are considered, though more rarely. Studies of the ecotoxicity of the particulate phase of effluents must also be taken into account. It is also necessary to monitor the effluents of each of the specialised departments of the hospital studied. These steps is necessary to define realistic environmental management policies for hospitals (replacement of toxic products by less pollutant ones, etc.). Copyright © 2013 Elsevier B.V. All rights reserved.

Nanoecotoxicity Assessment of Graphene Oxide and its Relationship with Humic Acid.

PubMed

Castro, Vera L; Clemente, Zaira; Jonsson, Claudio; Silva, Mariana; Vallim, José Henrique; de Medeiros, Aline Maria Zigiotto; Martinez, Diego Stéfani T

2018-04-02

The risk assessment of nanomaterials (NMs) is essential for regulatory purposes and for sustainable nanotechnological development. Although the application of the graphene oxide (GO) has been widely exploited, its environmental risk is not well understood since several environmental conditions can affect the behavior and toxicity of it. In the present work, the GO effect from aquatic ecosystems was assessed considering the interaction with humic acid (HA) on nine organisms: Raphidocelis subcapitata (green algae), Lemna minor (aquatic plant), Lactuca sativa (lettuce), Daphnia magna (planktonic microcrustacea), Artemia salina (brine shrimp), Chironomus sancticaroli (chironomidae), Hydra attenuata (freshwater polyp), and Caenorhabditis elegans and Panagrolaimus sp (nematodes). The No Observed Effect Concentration (NOEC) was calculated for each organism. The different criteria used to calculate NOEC values were transformed and plotted as a log-logistic function. The hypothetical hazardous concentration values HC5-50 were respectively 0.023 (0.005-0.056) and 0.10 (0.031-0.31) mg L -1 for GO with and without humic acid, respectively. The safest scenario associated to the Predictive No Effect Concentration (PNEC) values for GO in the aquatic compartment were estimated as 20 - 100 µg L -1 (in the absence of humic acid) and 5 - 23 µg L -1 (in the presence of humic acid). Finally, the approach presented in this study contributed to the risk assessment of GO-based nanomaterials and the establishment of nano-regulations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Occurrence of acidic pharmaceuticals in raw and treated sewages and in receiving waters.

PubMed

Lindqvist, Niina; Tuhkanen, Tuula; Kronberg, Leif

2005-06-01

The occurrence of five acidic pharmaceuticals, ibuprofen, naproxen, ketoprofen, diclofenac and bezafibrate, in seven different sewage treatment plants (STP) and three receiving waters were determined. The analytical procedure included solid phase extraction, liquid chromatographic separation and detection by a triple-quadrupole mass spectrometer. The studied pharmaceuticals were found in all the STPs. The pattern of the occurrence of individual compounds was the same in every STP and matched the consumption figures reported in the literature. Ibuprofen is the most used pharmaceutical in Finland and was accordingly found to be the most abundant compound in the raw sewage. In the treatment processes, the highest removal rate was observed for ibuprofen and the lowest for diclofenac, 92%+/-8% and 26%+/-17%, respectively. Due to the incomplete removal in the STPs, the pharmaceuticals were found in rivers at the discharge points of the STP effluents. Downstream from the discharge points, the concentrations decreased significantly mainly due to dilution in the river water. The risk to the aquatic environment was estimated by a ratio of measured environmental concentration (MEC) and predicted no-effect concentration (PNEC). At the concentrations the compounds were found in the surface waters, they should not pose risk for the aquatic environment. However, at dry seasons and/or during malfunctions of STPs, ibuprofen could be associated with a risk in small river systems.

Pharmaceutical contamination in residential, industrial, and agricultural waste streams: risk to aqueous environments in Taiwan.

PubMed

Lin, Angela Yu-Chen; Yu, Tsung-Hsien; Lin, Cheng-Fang

2008-12-01

This is a comprehensive study of the occurrence of antibiotics, hormones and other pharmaceuticals in water sites that have major potential for downstream environmental contamination. These include residential (hospitals, sewage treatment plants, and regional discharges), industrial (pharmaceutical production facilities), and agricultural (animal husbandries and aquacultures) waste streams. We assayed 23 Taiwanese water sites for 97 targeted compounds, of which a significant number were detected and quantified. The most frequently detected compounds were sulfamethoxazole, caffeine, acetaminophen, and ibuprofen, followed closely by cephalexin, ofloxacin, and diclofenac, which were detected in >91% of samples and found to have median (maximum) concentrations of 0.2 (5.8), 0.39 (24.0), 0.02 (100.4), 0.41 (14.5), 0.15 (31.4), 0.14 (13.6) and 0.083 (29.8) microg/L, respectively. Lincomycin and acetaminophen had high measured concentrations (>100 microg/L), and 35 other pharmaceuticals occurred at the microg/L level. These incidence and concentration results correlate well with published data for other worldwide locations, as well as with Taiwanese medication usage data, suggesting a human contamination source. Many pharmaceuticals also occurred at levels exceeding predicted no-effect concentrations (PNEC), warranting further investigation of their occurrence and fate in receiving waters, as well as the overall risks they pose for local ecosystems and human residents. The information provided here will also be useful for development of strategies for regulation and remediation.

Approach on environmental risk assessment of nanosilver released from textiles.

PubMed

Voelker, Doris; Schlich, Karsten; Hohndorf, Lars; Koch, Wolfgang; Kuehnen, Ute; Polleichtner, Christian; Kussatz, Carola; Hund-Rinke, Kerstin

2015-07-01

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related to PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly introduce AgNM into the textile fiber since this will strongly minimize the release of AgNM during washing. If this is not possible due to technical limitations or other reasons, the introduction of a threshold level controlling the release of AgNM from textiles is suggested. It has to be noted that this study is a case study which is only valid for the investigated NM-300K and its potential application in textiles. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Probabilistic modeling of the flows and environmental risks of nano-silica.

PubMed

Wang, Yan; Kalinina, Anna; Sun, Tianyin; Nowack, Bernd

2016-03-01

Nano-silica, the engineered nanomaterial with one of the largest production volumes, has a wide range of applications in consumer products and industry. This study aimed to quantify the exposure of nano-silica to the environment and to assess its risk to surface waters. Concentrations were calculated for four environmental (air, soil, surface water, sediments) and two technical compartments (wastewater, solid waste) for the EU and Switzerland using probabilistic material flow modeling. The corresponding median concentration in surface water is predicted to be 0.12 μg/l in the EU (0.053-3.3 μg/l, 15/85% quantiles). The concentrations in sediments in the complete sedimentation scenario were found to be the largest among all environmental compartments, with a median annual increase of 0.43 mg/kg · y in the EU (0.19-12 mg/kg · y, 15/85% quantiles). Moreover, probabilistic species sensitivity distributions (PSSD) were computed and the risk of nano-silica in surface waters was quantified by comparing the predicted environmental concentration (PEC) with the predicted no-effect concentration (PNEC) distribution, which was derived from the cumulative PSSD. This assessment suggests that nano-silica currently poses no risk to aquatic organisms in surface waters. Further investigations are needed to assess the risk of nano-silica in other environmental compartments, which is currently not possible due to a lack of ecotoxicological data. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrence and fate of emerging contaminants in municipal wastewater treatment plants from different geographical regions-a review.

PubMed

Tran, Ngoc Han; Reinhard, Martin; Gin, Karina Yew-Hoong

2018-04-15

Emerging contaminants, such as antibiotics, pharmaceuticals, personal care products, hormones, and artificial sweeteners, are recognized as new classes of water contaminants due to their proven or potential adverse effects on aquatic ecosystems and human health. This review provides comprehensive data on the occurrence of 60 emerging contaminants (ECs) in influent, treated effluent, sludge, and biosolids in wastewater treatment plants (WWTPs). In particular, data on the occurrence of ECs in the influents and effluents of WWTPs are systematically summarized and categorized according to geographical regions (Asia, Europe, and North America). The occurrence patterns of ECs in raw influent and treated effluents of WWTPs between geographical regions were compared and evaluated. Concentrations of most ECs in raw influent in Asian region tend to be higher than those in European and North American countries. Many antibiotics were detected in the influents and effluents of WWTPs at concentrations close to or exceeding the predicted no-effect concentrations (PNECs) for resistance selection. The efficacy of EC removal by sorption and biodegradation during wastewater treatment processes are discussed in light of kinetics and parameters, such as sorption coefficients (K d ) and biodegradation constants (k biol ), and physicochemical properties (i.e. log K ow and pK a ). Commonly used sampling and monitoring strategies are critically reviewed. Analytical research needs are identified, and novel investigative approaches for future monitoring studies are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distribution and ecological risk of antibiotics in a typical effluent-receiving river (Wangyang River) in north China.

PubMed

Jiang, Yonghai; Li, Mingxiao; Guo, Changsheng; An, Da; Xu, Jian; Zhang, Yuan; Xi, Beidou

2014-10-01

In this study, the occurrence and distribution of sixteen antibiotics belonging to four groups in surface water, sediment and groundwater samples from the Wangyang River (WYR), a typical river receiving sewage discharges were investigated. Laboratory analyses revealed that antibiotics were widely distributed in the studied area. The aqueous samples were unavoidably contaminated with antibiotics, and the target antibiotics present in high levels were oxytetracycline, tetracycline, chlortetracycline, ofloxacin, sulfamethoxazole, and trimethoprim, with maximum concentrations of the individual contaminant at 3.6×10(5), 9.7×10(3), 6.9×10(4), 1.2×10(4), 4.8×10(3), and 1.1×10(3) ng L(-1), respectively. Oxytetracycline, tetracycline, ciprofloxacin and roxithromycin were the most frequently detected compounds in sediment samples, with maximum concentrations of the individual contaminant at 1.6×10(5), 1.7×10(4), 2.1×10(3) and 2.5×10(3) ng g(-1), respectively. The results also revealed that the high intensity of aquaculture activities could contribute to the increasing levels of antibiotics in the area. According to the ratios of measured environmental concentration (MEC) to predicted no-effect concentration (PNEC), chlortetracycline, tetracycline, ofloxacin, ciprofloxacin, erythromycin-H2O and sulfamethoxazole may present possible environmental risk to Pseudokirchneriella subcapitata, Synechococcus leopoliensis and M. aeruginosa. Attention should be given to the long-term ecological effects caused by the continuous discharge of antibiotics in the WYR area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Toxicity of tributyltin (TBT) to terrestrial organisms and its species sensitivity distribution.

PubMed

Silva, Patrícia V; Silva, Ana Rita R; Mendo, Sónia; Loureiro, Susana

2014-01-01

The contamination of the terrestrial environment by disposal of tributyltin (TBT) by contaminated harbour sediments, sewage sludge and/or biocide products has been raising concerns and it may pose a risk to soil invertebrates and plants. This study aimed to improve the amount and quality of data for TBT toxicity in soils in order to assess the ecological risk of TBT to the terrestrial ecosystems. For this, bioassays were performed with the species Porcellionides pruinosus, Folsomia candida, Brassica rapa and Triticum aestivum to evaluate the toxic effects of TBT (as chloride) on these species. Additionally, this study contributed to increase the amount of data concerning TBT toxicity on soil dwelling organisms. The results showed a dose-response relationship between TBT concentration and the increase of toxicity in all species tested. These results were collated with results from literature to construct species sensitivity distributions (SSDs) and to calculate the hazardous concentration at 5% (HC₅) for all data, for each type of soil and TBT formulation used. The HC₅ value for TBT in soil was 2.06 mg TBT/kg soil dw. Little information is available concerning the concentrations of TBT in soils. In addition the predicted no-effect concentration (PNEC) value was determined to be 30 μg/kg soil. Only one study was found referring to TBT contaminated soils, and where TBT concentrations were lower than 0.024 μg TBT/kg for the wetland soil. Therefore it can be concluded that the real TBT concentrations determined represent low risk for environmental effects. In conclusion, the construction of SSDs and the calculation of HC5 using all the data available showed to be a more suitable method rather than the construction of several SSDs for each soil and TBT types. Further investigations concerning TBT concentrations and toxicity on soil organisms need to be performed to increase data and improve risk calculations. © 2013.

Impact of treated wastewater reuse and floods on water quality and fish health within a water reservoir in an arid climate.

PubMed

Zaibel, Inbal; Zilberg, Dina; Groisman, Ludmila; Arnon, Shai

2016-07-15

Treated wastewater (TWW) reuse for agricultural irrigation is a well-established approach to coping with water shortages in semi-arid and arid environments. Recently, additional uses of TWW have emerged, including streamflow augmentation and aquatic ecosystem restoration. The purpose of the current study was to evaluate the water quality and fish health, in an artificial reservoir located in an arid climate (the Yeruham Reservoir, Israel), which regularly receives TWW and sporadic winter floods. The temporal distribution of water levels, nutrients and organic micropollutants (OMPs) were measured during the years 2013-2014. OMPs were also measured in sediment and fish tissues. Finally, the status of fish health was evaluated by histopathology. Water levels and quality were mainly influenced by seasonal processes such as floods and evaporation, and not by the discharge of TWW. Out of 16 tested OMPs, estrone, carbamazepine, diclofenac and bezafibrate were found in the reservoir water, but mostly at concentrations below the predicted no-effect concentration (PNEC) for fish. Concentrations of PCBs and dioxins in fish muscle and liver were much lower than the EU maximal permitted concentrations, and similar to concentrations that were found in food fish in Israel and Europe. In the histopathological analysis, there were no evident tissue abnormalities, and low to moderate infection levels of fish parasites were recorded. The results from the Yeruham Reservoir demonstrated a unique model for the mixture effect between TWW reuse and natural floods to support a unique stable and thriving ecosystem in a water reservoir located in an arid region. This type of reservoir can be widely used for recreation, education, and the social and economic development of a rural environment, such as has occurred in the Yeruham region. Copyright © 2016 Elsevier B.V. All rights reserved.

Food web modeling of a river ecosystem for risk assessment of down-the-drain chemicals: a case study with AQUATOX.

PubMed

Lombardo, Andrea; Franco, Antonio; Pivato, Alberto; Barausse, Alberto

2015-03-01

Conventional approaches to estimating protective ecotoxicological thresholds of chemicals, i.e. predicted no-effect concentrations (PNEC), for an entire ecosystem are based on the use of assessment factors to extrapolate from single-species toxicity data derived in the laboratory to community-level effects on ecosystems. Aquatic food web models may be a useful tool to improve the ecological realism of chemical risk assessment because they enable a more insightful evaluation of the fate and effects of chemicals in dynamic trophic networks. A case study was developed in AQUATOX to simulate the effects of the anionic surfactant linear alkylbenzene sulfonate and the antimicrobial triclosan on a lowland riverine ecosystem. The model was built for a section of the River Thames (UK), for which detailed ecological surveys were available, allowing for a quantification of energy flows through the whole ecosystem. A control scenario was successfully calibrated for a simulation period of one year, and tested for stability over six years. Then, the model ecosystem was perturbed with varying inputs of the two chemicals. Simulations showed that both chemicals rapidly approach steady-state, with internal concentrations in line with the input bioconcentration factors throughout the year. At realistic environmental concentrations, both chemicals have insignificant effects on biomass trends. At hypothetical higher concentrations, direct and indirect effects of chemicals on the ecosystem dynamics emerged from the simulations. Indirect effects due to competition for food sources and predation can lead to responses in biomass density of the same magnitude as those caused by direct toxicity. Indirect effects can both exacerbate or compensate for direct toxicity. Uncertainties in key model assumptions are high as the validation of perturbed simulations remains extremely challenging. Nevertheless, the study is a step towards the development of realistic ecological scenarios and their potential use in prospective risk assessment of down-the-drain chemicals. Copyright © 2014 Elsevier B.V. All rights reserved.

Removal of APIs and bacteria from hospital wastewater by MBR plus O(3), O(3) + H(2)O(2), PAC or ClO(2).

PubMed

Nielsen, U; Hastrup, C; Klausen, M M; Pedersen, B M; Kristensen, G H; Jansen, J L C; Bak, S N; Tuerk, J

2013-01-01

The objective of this study has been to develop technologies that can reduce the content of active pharmaceutical ingredients (APIs) and bacteria from hospital wastewater. The results from the laboratory- and pilot-scale testings showed that efficient removal of the vast majority of APIs could be achieved by a membrane bioreactor (MBR) followed by ozone, ozone + hydrogen peroxide or powdered activated carbon (PAC). Chlorine dioxide (ClO(2)) was significantly less effective. MBR + PAC (450 mg/l) was the most efficient technology, while the most cost-efficient technology was MBR + ozone (156 mg O(3)/l applied over 20 min). With MBR an efficient removal of Escherichia coli and enterococci was measured, and no antibiotic resistant bacteria were detected in the effluent. With MBR + ozone and MBR + PAC also the measured effluent concentrations of APIs (e.g. ciprofloxacin, sulfamethoxazole and sulfamethizole) were below available predicted no-effect concentrations (PNEC) for the marine environment without dilution. Iodinated contrast media were also reduced significantly (80-99% for iohexol, iopromide and ioversol and 40-99% for amidotrizoateacid). A full-scale MBR treatment plant with ozone at a hospital with 900 beds is estimated to require an investment cost of €1.6 mill. and an operating cost of €1/m(3) of treated water.

Polynucleobacter meluiroseus sp. nov., a bacterium isolated from a lake located in the mountains of the Mediterranean island of Corsica.

PubMed

Pitt, Alexandra; Schmidt, Johanna; Lang, Elke; Whitman, William B; Woyke, Tanja; Hahn, Martin W

2018-06-01

Strain AP-Melu-1000-B4 was isolated from a lake located in the mountains of the Mediterranean island of Corsica (France). Phenotypic, chemotaxonomic and genomic traits were investigated. Phylogenetic analyses based on 16S rRNA gene sequencing referred the strain to the cryptic species complex PnecC within the genus Polynucleobacter. The strain encoded genes for biosynthesis of proteorhodopsin and retinal. When pelleted by centrifugation the strain showed an intense rose colouring. Major fatty acids were C16 : 1ω7c, C16 : 0, C18 : 1ω7c and summed feature 2 (C16 : 1 isoI and C14 : 0-3OH). The sequence of the 16S rRNA gene contained an indel which was not present in any previously described Polynucleobacter species. Genome sequencing revealed a genome size of 1.89 Mbp and a G+C content of 46.6 mol%. In order to resolve the phylogenetic position of the new strain within subcluster PnecC, its phylogeny was reconstructed from sequences of 319 shared genes. To represent all currently described Polynucleobacter species by whole genome sequences, three type strains were additionally sequenced. Our phylogenetic analysis revealed that strain AP-Melu-100-B4 occupied a basal position compared with previously described PnecC strains. Pairwise determined whole genome average nucleotide identity (gANI) values suggested that strain AP-Melu-1000-B4 represents a new species, for which we propose the name Polynucleobacter meluiroseus sp. nov. with the type strain AP-Melu-1000-B4 T (=DSM 103591 T =CIP 111329 T ).

Chronic toxicity of copper to five benthic invertebrates in laboratory-formulated sediment: sensitivity comparison and preliminary risk assessment.

PubMed

Roman, Yblin E; De Schamphelaere, Karel A C; Nguyen, Lien T H; Janssen, Colin R

2007-11-15

Five benthic organisms commonly used for sediment toxicity testing were chronically (28 to 35 days) exposed to copper in standard laboratory-formulated sediment (following Organization for Economic Cooperation and Development guidelines) and lethal and sub-lethal toxicities were evaluated. Sub-lethal endpoints considered were reproduction and biomass production for Lumbriculus variegatus, growth and reproduction for Tubifex tubifex, growth and emergence for Chironomus riparius, and growth for Gammarus pulex and Hyalella azteca. Expressed on whole-sediment basis the observed lethal sensitivity ranking (from most to least sensitive) was: G. pulex>L. variegatus>H. azteca=C. riparius=T. tubifex, with median chronic lethal concentrations (LC50) between 151 and 327 mg/kg dry wt. The sub-lethal sensitivity ranking (from most to least sensitive, with the most sensitive endpoint between parentheses): C. riparius (emergence)>T. tubifex (reproduction)=L. variegatus (reproduction)>G. pulex (growth)>H. azteca (growth), with median effective concentrations (EC50) between 59.2 and 194 mg/kg dry wt. No observed effect concentrations (NOEC) or 10% effective concentrations (EC10) for the five benthic invertebrates were used to perform a preliminary risk assessment for copper in freshwater sediment by means of (a) the "assessment factor approach" or (b) the statistical extrapolation approach (species sensitivity distribution). Depending on the data (NOEC or EC10) and the methodology used, we calculated a Predicted No Effect Concentration (PNEC) for sediment between 3.3 and 47.1 mg Cu/dry wt. This range is similar to the range of natural (geochemical) background concentrations of copper in sediments in Europe, i.e. 90% of sediments have a concentration between 5 and 49 mg Cu/kg dry wt. A detailed analysis of the outcome of this preliminary exercise highlighted that multiple issues need to be explored for achieving a scientifically more sound risk assessment and for the development of robust sediment quality criteria for copper, including (i) the use of the assessment factor approach vs. the statistical extrapolation approach, (ii) the importance of bioavailability modifying factors (e.g., organic carbon, acid volatile sulfide), and (iii) the influence of prevailing geochemical (bioavailable) background concentrations on the copper sensitivity of local benthic biota.

Sources identification of antibiotic pollution combining land use information and multivariate statistics.

PubMed

Li, Jia; Zhang, Haibo; Chen, Yongshan; Luo, Yongming; Zhang, Hua

2016-07-01

To quantify the extent of antibiotic contamination and to identity the dominant pollutant sources in the Tiaoxi River Watershed, surface water samples were collected at eight locations and analyzed for four tetracyclines and three sulfonamides using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The observed maximum concentrations of tetracycline (623 ng L(-1)), oxytetracycline (19,810 ng L(-1)), and sulfamethoxazole (112 ng L(-1)) exceeded their corresponding Predicted No Effect Concentration (PNEC) values. In particular, high concentrations of antibiotics were observed in wet summer with heavy rainfall. The maximum concentrations of antibiotics appeared in the vicinity of intensive aquaculture areas. High-resolution land use data were used for identifying diffuse source of antibiotic pollution in the watershed. Significant correlations between tetracycline and developed (r = 0.93), tetracycline and barren (r = 0.87), oxytetracycline and barren (r = 0.82), and sulfadiazine and agricultural facilities (r = 0.71) were observed. In addition, the density of aquaculture significantly correlated with doxycycline (r = 0.74) and oxytetracycline (r = 0.76), while the density of livestock significantly correlated with sulfadiazine (r = 0.71). Principle Component Analysis (PCA) indicated that doxycycline, tetracycline, oxytetracycline, and sulfamethoxazole were from aquaculture and domestic sources, whereas sulfadiazine and sulfamethazine were from livestock wastewater. Flood or drainage from aquaculture ponds was identified as a major source of antibiotics in the Tiaoxi watershed. A hot-spot map was created based on results of land use analysis and multi-variable statistics, which provided an effective management tool of sources identification in watersheds with multiple diffuse sources of antibiotic pollution.

Effects of the neonicotinoids acetamiprid and thiacloprid in their commercial formulations on soil fauna.

PubMed

Renaud, Mathieu; Akeju, Tolutope; Natal-da-Luz, Tiago; Leston, Sara; Rosa, João; Ramos, Fernando; Sousa, José Paulo; Azevedo-Pereira, Henrique M V S

2018-03-01

Neonicotinoids are the most prominent group of insecticides in the world and are commercialized in over 120 countries for the control of agricultural pests mainly due to their broad-spectrum activity and versatility in application. Though non-target soil organisms are likely to be exposed during application, there is paucity of information in scientific literature regarding their sensitivity to neonicotinoids. This study attempts to fill this gap by evaluating, under laboratory conditions, the chronic toxicity of the neonicotinoids thiacloprid and acetamiprid, through their commercial formulations (CF), to the soil invertebrates Folsomia candida, Eisenia andrei and Enchytraeus crypticus. Results obtained indicate that the relative reproductive sensitivity of the test organisms can be expressed as: F. candida = E. andrei > E. crypticus (for acetamiprid CF) and E. andrei > F. candida > E. crypticus (for thiacloprid CF). To extrapolate from laboratory test results to field conditions, predicted environmental concentrations (PECs) and predicted no-effect concentrations were derived. Calculated toxicity-exposure ratios (TER = EC10/PEC) were below trigger values for acetamiprid and thiacloprid, when estimated with initial PEC. While estimated hazard quotients (HQ = PEC/PNEC), were greater than the European Commission trigger value. Therefore, with the current data under standard environmental risk assessment schemes it can be considered that the risk of thiacloprid and acetamiprid to the soil compartment is unacceptable. However, further research into the effects of these substances on different organisms is required to increase the confidence in the risk assessment estimates for instance, by calculating hazardous concentrations using species sensitivity distribution curves. Copyright © 2017 Elsevier Ltd. All rights reserved.

Extracellular pH Modulates Neuroendocrine Prostate Cancer Cell Metabolism and Susceptibility to the Mitochondrial Inhibitor Niclosamide

PubMed Central

Ippolito, Joseph E.; Brandenburg, Matthew W.; Ge, Xia; Crowley, Jan R.; Kirmess, Kristopher M.; Som, Avik; D’Avignon, D. Andre; Arbeit, Jeffrey M.; Achilefu, Samuel; Yarasheski, Kevin E.; Milbrandt, Jeffrey

2016-01-01

Neuroendocrine prostate cancer is a lethal variant of prostate cancer that is associated with castrate-resistant growth, metastasis, and mortality. The tumor environment of neuroendocrine prostate cancer is heterogeneous and characterized by hypoxia, necrosis, and numerous mitoses. Although acidic extracellular pH has been implicated in aggressive cancer features including metastasis and therapeutic resistance, its role in neuroendocrine prostate cancer physiology and metabolism has not yet been explored. We used the well-characterized PNEC cell line as a model to establish the effects of extracellular pH (pH 6.5, 7.4, and 8.5) on neuroendocrine prostate cancer cell metabolism. We discovered that alkalinization of extracellular pH converted cellular metabolism to a nutrient consumption-dependent state that was susceptible to glucose deprivation, glutamine deprivation, and 2-deoxyglucose (2-DG) mediated inhibition of glycolysis. Conversely, acidic pH shifted cellular metabolism toward an oxidative phosphorylation (OXPHOS)-dependent state that was susceptible to OXPHOS inhibition. Based upon this mechanistic knowledge of pH-dependent metabolism, we identified that the FDA-approved anti-helminthic niclosamide depolarized mitochondrial potential and depleted ATP levels in PNEC cells whose effects were enhanced in acidic pH. To further establish relevance of these findings, we tested the effects of extracellular pH on susceptibility to nutrient deprivation and OXPHOS inhibition in a cohort of castrate-resistant prostate cancer cell lines C4-2B, PC-3, and PC-3M. We discovered similar pH-dependent toxicity profiles among all cell lines with these treatments. These findings underscore a potential importance to acidic extracellular pH in the modulation of cell metabolism in tumors and development of an emerging paradigm that exploits the synergy of environment and therapeutic efficacy in cancer. PMID:27438712

Risk-based prioritization of pharmaceuticals in the natural environment in Iraq.

PubMed

Al-Khazrajy, Omar S A; Boxall, Alistair B A

2016-08-01

Numerous studies have demonstrated the occurrence of pharmaceuticals in the natural environment, raising concerns about their impact on non-target organisms or human health. One region where little is known about the exposure and effects of pharmaceuticals in the environment is Iraq. Due to the high number of pharmaceuticals used by the public health sector in Iraq (hospitals and care centres) and distributed over the counter, there is a need for a systematic approach for identifying substances that should be monitored in the environment in Iraq and assessed in terms of environmental risk. In this study, a risk-based prioritization approach was applied to 99 of the most dispensed pharmaceuticals in three Iraqi cities, Baghdad, Mosul and Basrah. Initially, information on the amounts of pharmaceuticals used in Iraq was obtained. The top used medicines were found to be paracetamol, amoxicillin and metformin with total annual consumption exceeding 1000 tonnes per year. Predicted environmental concentrations (PECs) and predicted no-effect concentrations (PNECs), derived from ecotoxicological end-points and effects related to the therapeutic mode of action, were then used to rank the pharmaceuticals in terms of risks to different environmental compartments. Active pharmaceutical ingredients used as antibiotics, antidepressants and analgesics were identified as the highest priority in surface water, sediment and the terrestrial environment. Antibiotics were also prioritized according to their susceptibility to kill or inhibit the growth of bacteria or to accelerate the evolution and dissemination of antibiotic-resistant genes in water. Future work will focus on understanding the occurrence, fate and effects of some of highly prioritized substances in the environment.

Testing REACH draft technical guidance notes for conducting chemical safety assessments-the experience of a downstream user of a preparation.

PubMed

Gade, Anne Lill; Ovrebø, Steinar; Hylland, Ketil

2008-07-01

The goal of REACH is the safe use of chemicals. This study examines the efficiency and usefulness of two draft technical guidance notes in the REACH Interim Project 3.2-2 for the development of the chemical safety report and exposure scenarios. A case study was carried out for a paint system for protection of structural steel. The focuses of the study were risk assessment of preparations based on Derived No Effect Level (DNEL) and Predicted No Effect Concentrations (PNEC) and on effective and accurate communication in the supply chain. Exposure scenarios and generic descriptions of uses, risk management measures, and exposure determinants were developed. The study showed that communication formats, software tools, and guidelines for chemical risk assessment need further adjustment to preparations and real-life situations. Web platforms may simplify such communication. The downstream formulator needs basic substance data from the substance manufacturer during the pre-registration phase to develop exposure scenarios for preparations. Default values need to be communicated in the supply chain because these were critical for the derivation of applicable risk management demands. The current guidelines which rely on the available toxicological knowledge are insufficient to advise downstream users on how to develop exposure scenarios for preparations.

PCP in the freshwater and marine environment of the European Union.

PubMed

Muir, J; Eduljee, G

1999-09-15

This study collates monitoring data principally from 1991 to 1996, relating levels of pentachlorophenol (PCP) in the freshwater and marine environments of the European Union (EU) Member States of Belgium, France, Germany, the Netherlands and the UK. In general, PCP levels in the open freshwater and marine environments displayed a downward trend in these countries, and where increased PCP concentrations were observed, these were tentatively linked to specific point discharges. The monitoring data were compared against the relevant predicted no-effect concentration (PNEC) for PCP in a particular environmental medium. On this basis, the study suggests that PCP does not pose a risk to the coastal, estuarine, marine waters or marine sediments of the above countries, and that any risks posed by PCP to the freshwater environment can largely be attributed to sediments contaminated with PCP from historic usage, or due to the continued use of small quantities of sodium pentachlorophenyl laurate in northern France. Further analysis of the data was not possible owing to the lack of systematic reporting by Member States, the lack of information on usage quantities and patterns, and inconsistent environmental surveillance and reporting of environmental data. This is particularly relevant for south-west France, Portugal and north-east Spain, the region which accounts for almost 90% of the EU's consumption of NaPCP. These issues need to be addressed at a pan-European level to better inform the selection of risk management measures and to improve the effectiveness of such measures.

PETRORISK: a risk assessment framework for petroleum substances.

PubMed

Redman, Aaron D; Parkerton, Thomas F; Comber, Mike H I; Paumen, Miriam Leon; Eadsforth, Charles V; Dmytrasz, Bhodan; King, Duncan; Warren, Christopher S; den Haan, Klaas; Djemel, Nadia

2014-07-01

PETRORISK is a modeling framework used to evaluate environmental risk of petroleum substances and human exposure through these routes due to emissions under typical use conditions as required by the European regulation for the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). Petroleum substances are often complex substances comprised of hundreds to thousands of individual hydrocarbons. The physicochemical, fate, and effects properties of the individual constituents within a petroleum substance can vary over several orders of magnitude, complicating risk assessment. PETRORISK combines the risk assessment strategies used on single chemicals with the hydrocarbon block approach to model complex substances. Blocks are usually defined by available analytical characterization data on substances that are expressed in terms of mass fractions for different structural chemical classes that are specified as a function of C number or boiling point range. The physicochemical and degradation properties of the blocks are determined by the properties of representative constituents in that block. Emissions and predicted exposure concentrations (PEC) are then modeled using mass-weighted individual representative constituents. Overall risk for various environmental compartments at the regional and local level is evaluated by comparing the PECs for individual representative constituents to corresponding predicted no-effect concentrations (PNEC) derived using the Target Lipid Model. Risks to human health are evaluated using the overall predicted human dose resulting from multimedia environmental exposure to a substance-specific derived no-effect level (DNEL). A case study is provided to illustrate how this modeling approach has been applied to assess the risks of kerosene manufacture and use as a fuel. © 2014 SETAC.

What level of estrogenic activity determined by in vitro assays in municipal waste waters can be considered as safe?

PubMed

Jarošová, Barbora; Bláha, Luděk; Giesy, John P; Hilscherová, Klára

2014-03-01

In vitro assays are broadly used tools to evaluate the estrogenic activity in Waste Water Treatment Plant (WWTP) effluents and their receiving rivers. Since potencies of individual estrogens to induce in vitro and in vivo responses can differ it is not possible to directly evaluate risks based on in vitro measures of estrogenic activity. Estrone, 17beta-estradiol, 17alfa-ethinylestradiol and to some extent, estriol have been shown to be responsible for the majority of in vitro estrogenic activity of municipal WWTP effluents. Therefore, in the present study safe concentrations of Estrogenic Equivalents (EEQs-SSE) in municipal WWTP effluents were derived based on simplified assumption that the steroid estrogens are responsible for all estrogenicity determined with particular in vitro assays. EEQs-SSEs were derived using the bioassay and testing protocol-specific in vitro potencies of steroid estrogens, in vivo predicted no effect concentration (PNECs) of these compounds, and their relative contributions to the overall estrogenicity detected in municipal WWTP effluents. EEQs-SSEs for 15 individual bioassays varied from 0.1 to 0.4ng EEQ/L. The EEQs-SSEs are supposed to be increased by use of location-specific dilution factors of WWTP effluents entering receiving rivers. They are applicable to municipal wastewater and rivers close to their discharges, but not to industrial waste waters. Copyright © 2013 Elsevier Ltd. All rights reserved.

Degradation and dissipation of the veterinary ionophore lasalocid in manure and soil.

PubMed

Žižek, Suzana; Dobeic, Martin; Pintarič, Štefan; Zidar, Primož; Kobal, Silvestra; Vidrih, Matej

2015-11-01

Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It is excreted from the treated animals mostly in its active form and enters the environment with the use of contaminated manure on agricultural land. To properly assess the risk that lasalocid poses to the environment, it is necessary to know its environmental concentrations as well as the rates of its degradation in manure and dissipation in soil. These values are still largely unknown. A research was undertaken to ascertain the rate of lasalocid degradation in manure under different storage conditions (aging in a pile or composting) and on agricultural soil after using lasalocid-contaminated manure. The results have shown that there is considerable difference in lasalocid degradation between aging manure with no treatment (t1/2=61.8±1.7 d) and composting (t1/2=17.5±0.8 d). Half-lives in soil are much shorter (on average 3.1±0.4 d). On the basis of the measured concentrations of lasalocid in soil after manure application, we can conclude that it can potentially be harmful to soil organisms (PEC/PNEC ratio of 1.18), but only in a worst-case scenario of using the maximum permissible amount of manure and immediately after application. To make certain that no harmful effects occur, composting is recommended. Copyright © 2014 Elsevier Ltd. All rights reserved.

Review of the ecotoxicological effects of emerging contaminants to soil biota.

PubMed

Gomes, Ana R; Justino, Celine; Rocha-Santos, Teresa; Freitas, Ana C; Duarte, Armando C; Pereira, Ruth

2017-08-24

In recent years, emerging contaminants (e.g. pesticides and their metabolites, pharmaceuticals, personal and house care products, life-style compounds, food additives, industrial products and wastes, as well as nanomaterials) have become a problem to the environment. In fact, the cumulative use of a panoply of chemical substances in agriculture, industrial activities, in our homes and in health care services has led to their recent appearance in detectable levels in soils, surface, and groundwater resources, with unpredictable consequences for these ecosystems. Few data exist regarding the toxicity and potential for bioaccumulation in biota. When available, data were obtained only for some representatives of the main groups of chemical substances, and for a limited number of species, following non-standard protocols. This makes difficult the calculation of predicted no effect concentrations (PNEC) and the existence of sufficient data to set limits for their release into the environment. This is particularly concerning for the soil compartment, since only recently the scientific community, regulators, and the public have realised the importance of protecting this natural resource and its services to guarantee the sustainability of terrestrial ecosystems and human well-being. In this context, this review paper aims to identify the major groups of soil emerging contaminants, their sources, pathways and receptors, and in parallel to analyse existing ecotoxicological data for soil biota.

Investigation of pharmaceuticals, personal care products and endocrine disrupting chemicals in a tropical urban catchment and the influence of environmental factors.

PubMed

You, Luhua; Nguyen, Viet Tung; Pal, Amrita; Chen, Huiting; He, Yiliang; Reinhard, Martin; Gin, Karina Yew-Hoong

2015-12-01

Previous studies showed the presence of multiple emerging organic contaminants (EOCs) in urban surface waters of Singapore even though there are no obvious direct wastewater discharges. In this study, we investigated the occurrence and distribution of 17 pharmaceuticals and personal care products (PPCPs) and endocrine disruptive compounds (EDCs) in a tropical urban catchment of Singapore. Monthly samples were collected from a reservoir and its 5 upstream tributaries during a 16-month period. Analysis of samples showed all sites had measurable PPCP and EDC concentrations, with caffeine (33.9-2980 ng/L), salicylic acid (5-838 ng/L), acetaminophen (<4-485.5 ng/L), BPA (<2-919.5 ng/L) and DEET (13-270 ng/L) being the most abundant. Marked differences in concentrations of target analytes between the reservoir and upstream tributaries were observed, and were tentatively attributed to the spatial differences in source inputs, water dilution capacity as well as natural attenuation of EOCs. Significant correlations between EOCs and conductivity, dissolved oxygen, chlorophyll a, turbidity, nutrients and cumulative precipitation were observed. These factors appeared to affect the distribution and attenuation of EOCs, depending on their physicochemical properties. Rainfall also influenced the temporal distribution of caffeine, BPA, triclosan, fipronil and DEET in the reservoir. Ecological risk assessment showed that caffeine, acetaminophen, estrone, BPA, triclosan and fipronil may warrant further survey. In particular, BPA levels exceeded the literature-based Predicted No-Effect Concentration (PNEC) value, highlighting the need for source control and/or water remediation in this urban catchment. Copyright © 2015 Elsevier B.V. All rights reserved.

Marine environmental risk assessment and acute water quality criterion for pentachlorophenol in coastal waters.

PubMed

Beiras, R; Tato, T

2018-04-07

Pentachlorophenol (PCP) is a organochlorine biocide that, unlike most other organochlorines, is still in use as timber preservative. Its water solubility, high toxicity, bioaccumulation potential, and the concentrations reported in estuarine waters (up to 0.1 µg L -1 ) indicate it may pose a risk in coastal environments. Aquatic environrmental regulations are commonly based on standard freshwater organisms that may not represent the sensitivity of marine species. The present study consists of a water quality criteira reevalutation of PCP in coastal waters based on toxicity tests conducted recording sensitive endpoints of marine species representative of coastal ecosystems, following QA/QC standard procedures. The toxicity thresholds (EC 10 ) found were 4.69 µg L -1 for Paracentrotus lividus sea-urchin embryos, 6.47 µg L -1 for Mytilus galloprovincialis mussel larvae, and 78.4 µg L -1 for Isochrysis galbana cells. Therefore, there is only one order of magnitude between the predicted no-effect concentration (PNEC) for early life stages of bivalves and echinoderms and the maximum concentrations actually recorded in coastal water, which yields a remarkable risk quotient for PCP in these highly productive marine habitats. In addition, we have reviewed the ecotoxicological data on PCP toxicity on marine species representative of the main systematic groups, from algae to chordates, and derived a probabilistic acute saltwater quality criterion of 2.66 µg L -1 , intended to protect 95% of the marine species. Lack of adequate protection for marine ecosystems in some current PCP national guidelines has been identified.

Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam.

PubMed

Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

2015-01-01

The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks to the aquatic environment, yet the persistence of these antibiotics is of concern and might lead to chronic exposure of aquatic organisms as well as humans.

Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam

PubMed Central

Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

2015-01-01

The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks to the aquatic environment, yet the persistence of these antibiotics is of concern and might lead to chronic exposure of aquatic organisms as well as humans. PMID:26135396

Occurrences, toxicities, and ecological risks of benzophenone-3, a common component of organic sunscreen products: a mini-review.

PubMed

Kim, Sujin; Choi, Kyungho

2014-09-01

Benzophenone-3 (BP-3) has been widely used in sunscreens and many other consumer products, including cosmetics. The widespread use of BP-3 has resulted in its release into the water environment, and hence its potential impact on aquatic ecosystem is of concern. To better understand the risk associated with BP-3 in aquatic ecosystems, we conducted a thorough review of available articles regarding the physicochemical properties, toxicokinetics, environmental occurrence, and toxic effects of BP-3 and its suspected metabolites. BP-3 is lipophilic, photostable, and bioaccumulative, and can be rapidly absorbed via oral and dermal routes. BP-3 is reported to be transformed into three major metabolites in vivo, i.e., benzophenone-1 (BP-1), benzophenone-8 (BP-8), and 2,3,4-trihydroxybenzophenone (THB). BP-1 has a longer biological half-life than its parent compound and exhibits greater estrogenic potency in vitro. BP-3 has been detected in water, soil, sediments, sludge, and biota. The maximum detected level in ambient freshwater and seawater is 125ng/L and 577.5ng/L, respectively, and in wastewater influent is 10,400ng/L. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents. BP-3 and its derivatives have been also detected in fish lipid. In humans, BP-3 has been detected in urine, serum, and breast milk samples worldwide. BP-1 has also been detected in placental tissues of delivering women. While sunscreens and cosmetics are known to be major sources of exposure, the fact that BP-3 has been detected frequently among young children and men suggests other sources. An increasing number of in vitro studies have indicated the endocrine disrupting capacity of BP-3. Based on a receptor binding assay, BP-3 has shown strong anti-androgenic and weak estrogenic activities but at the same time BP-3 displays anti-estrogenic activity as well. Predicted no effect concentration (PNEC) for BP-3 was derived at 1.32μg/L. The levels observed in ambient water are generally an order of magnitude lower than the PNEC, but in wastewater influents, hazard quotients (HQs) greater than 1 were noted. Considering limited ecotoxicological information and significant seasonal and spatial variations of BP-3 in water, further studies on environmental monitoring and potential consequences of long-term exposure in aquatic ecosystem are warranted. Copyright © 2014 Elsevier Ltd. All rights reserved.

Environmental risk assessment of medicinal products for human use according to European Commission recommendations.

PubMed

Huschek, Gerd; Hansen, Peter D; Maurer, Hans H; Krengel, Dietmar; Kayser, Anja

2004-06-01

Presented here, based on new recommendations of the European Commission, is an environmental risk assessment (ERA) of a selected group of pharmaceuticals for Phase I, environmental exposure assessment, and Phase II Tier A, initial environmental fate and effect analysis. This pharmaceutical group is composed of the 111 highest-selling human drug substances that have annual sales in Germany of more than 5,000 kg. The data required for this ERA came from analyzing: (1) sales annually (in kg or IU) of the 2671 active pharmaceutical drug substances (2001) on the German market in all medicinal products sold by pharmacies (with and without prescriptions) and used in hospitals in 1996-2001; (2) the use pattern of drug substances as categorized according to Anatomical Therapeutic Chemical (ATC) classification indexes ATC3 and ATC7; (3) data for excretion, toxicity, and metabolites of the 111 selected human drug substances; (4) the physicochemical properties of these substances; and (5) the degradability of selected drug substances in sewage treatment plants (STPs) by using a validated and accredited liquid chromatography-electrospray ionization tandem mass spectrometry method. A correction factor for the pharmaceutical therapeutic (PT) activity of metabolites, the PT(Index) (excretion rate/100) for drug substances and PT active metabolites was established to refine the predicted environmental concentration (PEC(SURFACEWATER)). A refinement of the PEC(SURFACEWATER) was carried out with the market penetration factor of the human drug substances in Germany. In addition, for effect analysis the predicted no-effects concentration (PNEC) was calculated using assessment factors. The estimated PEC results were validated with the exposure results of effluents of the STPs. All results on ERA of drug substances have been documented in a Microsoft Access 2000 database. Copyright 2004 Wiley Periodicals, Inc.

Chemical stimulation in unconventional hydrocarbons extraction in the USA: a preliminary environmental risk assessment.

NASA Astrophysics Data System (ADS)

Sutra, Emilie; Spada, Matteo; Burgherr, Peter

2016-04-01

While the exploitation of unconventional resources recently shows an extensive development, the stimulation techniques in use in this domain arouse growing public concerns. Often in the shadow of the disputed hydraulic fracturing process, the matrix acidizing is however a complementary or alternative procedure to enhance the reservoir connectivity. Although acidizing processes are widespread within the traditional hydrocarbons sources exploration, the matrix acidizing does not appear to be commonly used in unconventional hydrocarbons formations due to their low permeability. Nonetheless, this process has been recently applied to the Monterey formation, a shale oil play in California. These stimulation fluids are composed by various chemicals, what represents a matter of concern for public as well as for authorities. As a consequence, a risk assessment implying an exposure and toxicity analysis is needed. Focusing on site surface accidents, e.g., leak of a chemical from a storage tank, we develop in this study concentration scenarios for different exposure pathways to estimate the potential environmental risk associated with the use of specific hazardous substances in the matrix acidizing process for unconventional hydrocarbon reservoirs in the USA. Primary, information about the usage of different hazardous substances have been collected in order to extract the most frequently used chemicals. Afterwards, a probabilistic estimation of the environmental risk associated with the use of these chemicals is carried out by comparing the Predicted Environmental Concentrations (PEC) distribution with the Predicted No Effect Concentrations (PNEC) value. The latter is collected from a literature review, whereas the PEC is estimated as probability distribution concentrations in different environmental compartments (e.g., soil) built upon various predefined accident scenarios. By applying a probabilistic methodology for the concentrations, the level at which the used chemicals could become risky for the environment can be determined. Additionally, these concentration levels are converted into corresponding quantities of hazardous substances in order to discuss implications in terms of safety measures and policy decisions.

Ecotoxicity of titanium silicon oxide (TiSiO4) nanomaterial for terrestrial plants and soil invertebrate species.

PubMed

Bouguerra, Sirine; Gavina, Ana; Ksibi, Mohamed; Rasteiro, Maria da Graça; Rocha-Santos, Teresa; Pereira, Ruth

2016-07-01

The huge evolution of nanotechnology and the commercialization of nanomaterials (NMs) positively contributed for innovation in several industrial sectors. Facing this rapid development and the emergence of NMs in the market, the release of this nanometric sized materials in the environment and the possible impact on different ecosystem components attracted the attention of researchers in the last few years. In our study we aimed to assess the impact of titanium silicon oxide nanomaterial (nano-TiSiO4) on soil biota to estimate a risk limit for this material. In the present research a battery of standardized ecotoxicological assays aimed at evaluating a wide range of endpoints (avoidance and reproduction of earthworms and collembolans, emergence/growth of four selected terrestrial plants) were carried out, using OECD artificial soil as test substrate spiked with aqueous suspension of different concentrations of nano-TiSiO4. The results showed a maximum avoidance percentage of 40% for earthworms (Esenia andrei) at the highest concentration tested (1000mgkg(-1) soildw of nano-TiSiO4). No significant effect on the reproductive function of both invertebrate species was recorded. Nevertheless, significant phytotoxic data was registered at least for the growth of dicotyledonous plant species (Lactuca sativa and Lycopersicon lycopersicum) with EC20 values ranging between 236 and 414 mg kg(-1) soildw of nano-TiSiO4 for L. sativa dry mass and fresh mass, respectively. Further, the characterization of nano-TiSiO4 in suspensions used to spike the soil, performed by Dynamic Light Scattering, showed the formation of aggregates with important average size diameter, thus demonstrating that the toxic effects observed were likely not size dependent. A deterministic PNEC (predicted no effect concentration) for this NM of 10.02mg kg(-1) soildw of nano-TiSiO4, is suggested, while no more ecotoxicological information exists. Copyright © 2016 Elsevier Inc. All rights reserved.

Environmental risk assessment of selected pharmaceuticals in Turkey.

PubMed

Oğuz, Merve; Mihçiokur, Hamdi

2014-07-01

In this study, environmental risks of selected pharmaceuticals were investigated to assess potential hazards. Ciprofloxacin, Clarithromycin, Cefuroxime axetil, antibiotics, Benzalkoniuman antiseptic, Paracetamol, an analgesic, and Naproxen, an anti-inflammatory, were selected due to their high rate of usage in Turkey. Ciprofloxacin was found to have the highest risk due to its high PEC/PNEC ratio (28.636). Benzalkonium, Paracetamol and Clarithromycin have a potential to cause environmental hazards. The biodegradation and biological concentration factors (BCF) of the drugs were also determined using EPA/STWIN and EPA/BCFWIN programs. The results illustrated that these pharmaceuticals are nonbiodegradable in wastewater treatment plants. The BCFs of Benzalkonium and Clarithromycin were found to be very high, 70.790 L/kg and 56.490 L/kg, respectively. It was suggested that alternative treatment methods other than biological ones should be investigated for these pharmaceuticals because of their low biodegradability. Also, unnecessary use of antibiotics is supposed to be discouraged to reduce environmental hazards. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of anionic surfactant concentrations in US effluents and probabilistic determination of their combined ecological risk in mixing zones.

PubMed

McDonough, Kathleen; Casteel, Kenneth; Itrich, Nina; Menzies, Jennifer; Belanger, Scott; Wehmeyer, Kenneth; Federle, Thomas

2016-12-01

Alcohol sulfates (AS), alcohol ethoxysulfates (AES), linear alkyl benzenesulfonates (LAS) and methyl ester sulfonates (MES) are anionic surfactants that are widely used in household detergents and consumer products resulting in over 1 million tons being disposed of down the drain annually in the US. A monitoring campaign was conducted which collected grab effluent samples from 44 wastewater treatment plants (WWTPs) across the US to generate statistical distributions of effluent concentrations for anionic surfactants. The mean concentrations for AS, AES, LAS and MES were 5.03±4.5, 1.95±0.7, 15.3±19, and 0.35±0.13μg/L respectively. Since each of these surfactants consist of multiple homologues that differ in their toxicity, the concentration of each homologue measured in an effluent sample was converted into a toxic unit (TU) by normalizing to the predicted no effect concentration (PNEC) derived from high tier effects data (mesocosm studies). The statistical distributions of the combined TUs in the effluents were used in combination with distributions of dilution factors for WWTP mixing zones to conduct a US-wide probabilistic risk assessment for the aquatic environment for each of the surfactants. The 90th percentile level of TUs for AS, AES, LAS and MES in mixing zones were 1.89×10 -2 , 2.73×10 -3 , 2.72×10 -2 , and 3.65×10 -5 under 7Q10 (lowest river flow occurring over a 7day period every 10years) low flow conditions. Because these surfactants have the same toxicological mode of action, the TUs were summed and the aquatic safety for anionic surfactants as a whole was assessed. At the 90th percentile level under the conservative 7Q10 low flow conditions the forecasted TUs were 4.21×10 -2 which indicates that there is a significant margin of safety for the class of anionic surfactants in US aquatic environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Ecological risk assessment of cheese whey effluents along a medium-sized river in southwest Greece.

PubMed

Karadima, Constantina; Theodoropoulos, Chris; Rouvalis, Angela; Iliopoulou-Georgudaki, Joan

2010-01-01

An ecological risk assessment of cheese whey effluents was applied in three critical sampling sites located in Vouraikos river (southwest Greece), while ecological classification using Water Framework Directive 2000/60/EU criteria allowed a direct comparison of toxicological and ecological data. Two invertebrates (Daphnia magna and Thamnocephalus platyurus) and the zebra fish Danio rerio were used for toxicological analyses, while the aquatic risk was calculated on the basis of the risk quotient (RQ = PEC/PNEC). Chemical classification of sites was carried out using the Nutrient Classification System, while benthic invertebrates were collected and analyzed for biological classification. Toxicological results revealed the heavy pollution load of the two sites, nearest to the point pollution source, as the PEC/PNEC ratio exceeded 1.0, while unexpectedly, no risk was detected for the most downstream site, due to the consequent interference of the riparian flora. These toxicological results were in agreement with the ecological analysis: the ecological quality of the two heavily impacted sites ranged from moderate to bad, whereas it was found good for the most downstream site. The results of the study indicate major ecological risk for almost 15 km downstream of the point pollution source and the potentiality of the water quality remediation by the riparian vegetation, proving the significance of its maintenance.

Study of pharmaceuticals in surface and wastewater from Cuernavaca, Morelos, Mexico: Occurrence and environmental risk assessment.

PubMed

Rivera-Jaimes, José Abraham; Postigo, Cristina; Melgoza-Alemán, Rosa María; Aceña, Jaume; Barceló, Damia; López de Alda, Miren

2018-02-01

The present work describes the first known study to date on the occurrence of pharmaceuticals in surface water and wastewater of Cuernavaca, the capital of the state of Morelos (México). Selected pharmaceuticals (a total of 35) were extracted from the collected water samples with a generic solid phase extraction (SPE) protocol and determined in the sample extracts by means of high-performance liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). A screening level risk assessment combining the measured environmental concentrations (MECs) with dose-response data based on predicted no-effect concentrations (PNECs) was also applied to estimate Hazard Quotients (HQs) for the pharmaceuticals detected in the investigated area. A total of twelve pharmaceuticals were found in the water samples analyzed, with detection frequencies above 78% and in most cases of 100%. Overall, the most abundant pharmaceuticals in surface water were the analgesic and anti-inflammatory drugs naproxen (732-4880ng/L), acetaminophen (354-4460ng/L), and diclofenac (258-1398ng/L), and the lipid regulator bezafibrate (286-2100ng/L). On the contrary, other compounds like the β-blocker atenolol and the psychiatric drug carbamazepine were found at only a few ng or tens of ng per liter in the Apatlaco River. Despite the fact that some of the most abundant compounds showed good removal (>97%) during wastewater treatment, concentrations downstream the WWTP were only slightly lower than upstream. This indicates the existence of additional inputs of untreated wastewater into the river. Based on the obtained HQ-values, the concentrations of ibuprofen, sulfamethoxazole, diclofenac and naproxen present in the river could pose a high toxicity risk for the aquatic ecosystem. These findings highlight these pharmaceuticals as relevant organic contaminants in the area of study and the need to further monitor them in order to adopt appropriate measures to safeguard the ecosystem, and eventually human health. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification, contribution, and estrogenic activity of potential EDCs in a river receiving concentrated livestock effluent in Southern Taiwan.

PubMed

Liu, Yung-Yu; Lin, Yi-Siou; Yen, Chia-Hung; Miaw, Chang-Ling; Chen, Ting-Chien; Wu, Meng-Chun; Hsieh, Chi-Ying

2018-04-27

We assessed 22 selected endocrine-disrupting compounds (EDCs) and other emerging, potentially endocrine-active compounds with estrogenic activity from the waters of the Wuluo River, southern Taiwan. This watershed receives high amounts of livestock and untreated household wastewaters. The river is surrounded by concentrated animal feedlot operations (CAFOs). River water samples were analyzed for selected compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS), T47D-KBluc reporter gene assay, and E-screen cell proliferation in vitro bioassay. Total concentrations of ∑alkylphenolic compounds (bisphenol A, 4-nonylphenol, t-nonylphenol, octylphenol, nonylphenol mono-ethoxylate, nonylphenol di-ethoxylate) were much higher than ∑estrogens (estrone, 17 β-estradiol, estriol, 17ß-ethynylestradiol, diethylstilbestrol), ∑preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben), ∑UV-filters (benzophenone, methyl benzylidene camphor, benzophenone-3), ∑antimicrobials (triclocarben, triclosan, chloroxylenol), and an insect repellent (diethyltoluamide) over four seasonal sampling periods. The highest concentration was found for bisphenol A with a mean of 302 ng/L. However, its contribution to estrogenic activity was not significant due to its relatively low estrogenic potency. Lower detection rates were found for BP, EE2, TCS, and PCMX, while DES and EP were not detected. E1 and E2 levels in raw water samples were 50% higher than the predicted no-effect concentrations (PNEC) for aquatic organisms of 6 and 2 ng/L, respectively. The potency of estrogenic activity ranged from 11.7 to 190.1 ng/L E2 T47D-Kbluc and 6.63 to 84.5 ng/L E2 E-Screen for extracted samples. Importantly, estrone contributed 50% of the overall activity in 60% and 44% of the samples based on T47D-KBluc and MCF-7 bioassays, followed by 17 ß-estradiol, highlighting the importance of total steroid estrogen loading. This study demonstrates that the estrogenic activity of target chemicals was comparable to levels found in different countries worldwide. More intense wastewater treatment is required in areas of intensive agriculture in order to prevent adverse impacts on the ambient environment and aquatic ecosystems. Copyright © 2018 Elsevier B.V. All rights reserved.

Investigation of PPCPs in wastewater treatment plants in Greece: occurrence, removal and environmental risk assessment.

PubMed

Kosma, Christina I; Lambropoulou, Dimitra A; Albanis, Triantafyllos A

2014-01-01

In the present work, an extensive study on the presence of eighteen pharmaceuticals and personal care products (PPCPs) in eight wastewater treatment plants (WWTPs) of Greece has been conducted. The study covered four sampling periods over 1-year, where samples (influents; effluents) from eight WWTPs of various cities in Greece were taken. All WWTPs investigated are equipped with conventional activated sludge treatment. A common pre-concentration step based on SPE was applied, followed by LC-UV/Vis-ESI-MS. Further confirmation of positive findings was accomplished by using LC coupled to a high resolution Orbitrap mass spectrometer. The results showed the occurrence of all target compounds in the wastewater samples with concentrations up to 96.65 μg/L. Paracetamol, caffeine, trimethoprim, sulfamethoxazole, carbamazepine, diclofenac and salicylic acid were the dominant compounds, while tolfenamic acid, fenofibrate and simvastatin were the less frequently detected compounds with concentrations in effluents below the LOQ. The removal efficiencies showed that many WWTPs were unable to effectively remove most of the PPCPs investigated. Finally, the study provides an assessment of the environmental risk posed by their presence in wastewaters by means of the risk quotient (RQ). RQs were more than unity for various compounds in the effluents expressing possible threat for the aquatic environment. Triclosan was found to be the most critical compound in terms of contribution and environmental risk, concluding that it should be seriously considered as a candidate for regulatory monitoring and prioritization on a European scale on the basis of realistic PNECs. The results of the extensive monitoring study contributed to a better insight on PPCPs in Greece and their presence in influent and effluent wastewaters. Furthermore, the unequivocal identification of two transformation products of trimethoprim in real wastewaters by using the advantages of the LTQ Orbitrap capabilities provides information that should be taken into consideration in future PPCP monitoring studies in wastewaters. © 2013.

Littered cigarette butts as a source of nicotine in urban waters

NASA Astrophysics Data System (ADS)

Roder Green, Amy L.; Putschew, Anke; Nehls, Thomas

2014-11-01

The effect of nicotine from littered cigarette butts on the quality of urban water resources has yet to be investigated. This two-part study addresses the spatial variation, seasonal dynamics and average residence time of littered cigarette butts in public space, as well as the release of nicotine from cigarette butts to run-off in urban areas during its residence time. Thereby, we tested two typical situations: release to standing water in a puddle and release during alternating rainfall and drying. The study took place in Berlin, Germany, a city which completely relies on its own water resources to meet its drinking water demand. Nine typical sites located in a central district, each divided into 20 plots were studied during five sampling periods between May 2012 and February 2013. The nicotine release from standardized cigarette butts prepared with a smoking machine was examined in batch and rainfall experiments. Littered cigarette butts are unevenly distributed among both sites and plots. The average butt concentration was 2.7 m-2 (SD = 0.6 m-2, N = 862); the maximum plot concentration was 48.8 butts m-2. This heterogeneity is caused by preferential littering (gastronomy, entrances, bus stops), redistribution processes such as litter removal (gastronomy, shop owners), and the increased accumulation in plots protected from mechanized street sweeping (tree pits, bicycle stands). No significant seasonal variation of cigarette butt accumulation was observed. On average, cigarette butt accumulation is characterized by a 6 days cadence due to the rhythm and effectiveness of street sweeping (mean weekly butt accumulation rate = 0.18 m-2 d-1; SD = 0.15 m-1). Once the butt is exposed to standing water, elution of nicotine occurs rapidly. Standardized butts released 7.3 mg g-1 nicotine in a batch experiment (equivalent to 2.5 mg L-1), 50% of which occurred within the first 27 min. In the rainfall experiment, the cumulative nicotine release from fifteen consecutive precipitation events (each 1.4 mm) was 3.8 mg g-1, with 47% during the first event. According to these results, one cigarette butt may contaminate an amount of 1000 L water to concentrations above the predicted no effect concentration (PNEC) of only 2.4 × 10-3 mg L-1 (Valcárcel et al., 2011). Given the continuous littering of cigarette butts, and the rapid release of nicotine, cigarette butts are assessed to be a relevant threat to the quality of urban waters and consequently to drinking water.

Validation of site-specific soil Ni toxicity thresholds with independent ecotoxicity and biogeochemistry data for elevated soil Ni.

PubMed

Hale, Beverley; Gopalapillai, Yamini; Pellegrino, Amanda; Jennett, Tyson; Kikkert, Julie; Lau, Wilson; Schlekat, Christian; McLaughlin, Mike J

2017-12-01

The Existing Substances Regulation Risk Assessments by the European Union (EU RA) generated new toxicity data for soil organisms exposed to Ni added to sixteen field-collected soils with low background concentration of metals and varying physico-chemical soil characteristics. Using only effective cation exchange capacity (eCEC) as a bioavailability correction, chronic toxicity of Ni in soils with a wide range of characteristics could be predicted within a factor of two. The objective of the present study was to determine whether this was also the case for three independent data sets of Ni toxicity thresholds. Two of the data sets were from Community Based Risk Assessments in Port Colborne ON, and Sudbury ON (Canada) for soils containing elevated concentrations of Ni, Co and Cu arising from many decades of Ni mining, smelting and refining. The third data set was the Metals in Asia study of soluble Ni added to field soils in China. These data yielded 72 leached and aged EC 10 /NOEC values for soil Ni, for arthropods, higher plants and woodlot structure and function. These were reduced to nine most sensitive single or geometric mean species/function endpoints, none of which were lower than the HC 5 predicted for a soil with an eCEC of 20 cmol/kg. Most of these leached and aged EC 10 /NOEC values were from soils co-contaminated with Cu, in some cases at its median HC 5 as predicted by the EU RA from soil characteristics. We conclude that the EU RA is protective of Ni toxicity to higher-tier ecological endpoints, including in mixture with Cu, before the assessment factor of 2 is applied. We suggest that for prospective risk assessment, the bioavailability based PNEC (HC 5 /2) be used as a conservative screen, but for retrospective and site-specific risk assessment, the bioavailability based HC 5 is sufficient. Copyright © 2017 Elsevier Ltd. All rights reserved.

Olefins and chemical regulation in Europe: REACH.

PubMed

Penman, Mike; Banton, Marcy; Erler, Steffen; Moore, Nigel; Semmler, Klaus

2015-11-05

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the European Union's chemical regulation for the management of risk to human health and the environment (European Chemicals Agency, 2006). This regulation entered into force in June 2007 and required manufacturers and importers to register substances produced in annual quantities of 1000 tonnes or more by December 2010, with further deadlines for lower tonnages in 2013 and 2018. Depending on the type of registration, required information included the substance's identification, the hazards of the substance, the potential exposure arising from the manufacture or import, the identified uses of the substance, and the operational conditions and risk management measures applied or recommended to downstream users. Among the content developed to support this information were Derived No-Effect Levels or Derived Minimal Effect Levels (DNELs/DMELs) for human health hazard assessment, Predicted No Effect Concentrations (PNECs) for environmental hazard assessment, and exposure scenarios for exposure and risk assessment. Once registered, substances may undergo evaluation by the European Chemicals Agency (ECHA) or Member State authorities and be subject to requests for additional information or testing as well as additional risk reduction measures. To manage the REACH registration and related activities for the European olefins and aromatics industry, the Lower Olefins and Aromatics REACH Consortium was formed in 2008 with administrative and technical support provided by Penman Consulting. A total of 135 substances are managed by this group including 26 individual chemical registrations (e.g. benzene, 1,3-butadiene) and 13 categories consisting of 5-26 substances. This presentation will describe the content of selected registrations prepared for 2010 in addition to the significant post-2010 activities. Beyond REACH, content of the registrations may also be relevant to other European activities, for example consideration of worker DNELs/DMELs for occupational exposure level setting, discussion of this aspect will be presented for 1,3-butadiene. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The presence and leachability of antimony in different wastes and waste handling facilities in Norway.

PubMed

Okkenhaug, G; Almås, Å R; Morin, N; Hale, S E; Arp, H P H

2015-11-01

The environmental behaviour of antimony (Sb) is gathering attention due to its increasingly extensive use in various products, particularly in plastics. Because of this it may be expected that plastic waste is an emission source for Sb in the environment. This study presents a comprehensive field investigation of Sb concentrations in diverse types of waste from waste handling facilities in Norway. The wastes included waste electrical and electronic equipment (WEEE), glass, vehicle fluff, combustibles, bottom ash, fly ash and digested sludge. The highest solid Sb concentrations were found in WEEE and vehicle plastic (from 1238 to 1715 mg kg(-1)) and vehicle fluff (from 34 to 4565 mg kg(-1)). The type of acid used to digest the diverse solid waste materials was also tested. It was found that HNO3:HCl extraction gave substantially lower, non-quantitative yields compared to HNO3:HF. The highest water-leachable concentration for wastes when mixed with water at a 1 : 10 ratio were observed for plastic (from 0.6 to 2.0 mg kg(-1)) and bottom ash (from 0.4 to 0.8 mg kg(-1)). For all of the considered waste fractions, Sb(v) was the dominant species in the leachates, even though Sb(iii) as Sb2O3 is mainly used in plastics and other products, indicating rapid oxidation in water. This study also presents for the first time a comparison of Sb concentrations in leachate at waste handling facilities using both active grab samples and DGT passive samples. Grab samples target the total suspended Sb, whereas DGT targets the sum of free- and other chemically labile species. The grab sample concentrations (from 0.5 to 50 μg L(-1)) were lower than the predicted no-effect concentration (PNEC) of 113 μg L(-1). The DGT concentrations were substantially lower (from 0.05 to 9.93 μg L(-1)) than the grab samples, indicating much of the Sb is present in a non-available colloidal form. In addition, air samples were taken from the chimney and areas within combustible waste incinerators, as well as from the vent of WEEE sorting facility. The WEEE vent had the highest Sb concentration (from <100 to 2200 ng m(-3)), which were orders of magnitude higher than the air surrounding the combustible shredder (from 25 to 217 ng m(-3)), and the incinerator chimney (from <30 to 100 ng m(-3)). From these results, it seems evident that Sb from waste is not an environmental concern in Norway, and that Sb is mostly readily recovered from plastic and bottom ash.

Occurrence of 1153 organic micropollutants in the aquatic environment of Vietnam.

PubMed

Chau, H T C; Kadokami, K; Duong, H T; Kong, L; Nguyen, T T; Nguyen, T Q; Ito, Y

2018-03-01

The rapid increase in the number and volume of chemical substances being used in modern society has been accompanied by a large number of potentially hazardous chemicals being found in environmental samples. In Vietnam, the monitoring of chemical substances is mainly limited to a small number of known pollutants in spite of rapid economic growth and urbanization, and there is an urgent need to examine a large number of chemicals to prevent impacts from expanding environmental pollution. However, it is difficult to analyze a large number of chemicals using existing methods, because they are time consuming and expensive. In the present study, we determined 1153 substances to grasp a pollution picture of microcontaminants in the aquatic environment. To achieve this objective, we have used two comprehensive analytical methods: (1) solid-phase extraction (SPE) and LC-TOF-MS analysis, and (2) SPE and GC-MS analysis. We collected 42 samples from northern (the Red River and Hanoi), central (Hue and Danang), and southern (Ho Chi Minh City and Saigon-Dongnai River) Vietnam. One hundred and sixty-five compounds were detected at least once. The compounds detected most frequently (>40 % samples) at μg/L concentrations were sterols (cholesterol, beta-sitosterol, stigmasterol, coprostanol), phthalates (bis(2-ethylhexyl) phthalate and di-n-butyl phthalate), and pharmaceutical and personal care products (caffeine, metformin). These contaminants were detected at almost the same detection frequency as in developed countries. The results reveal that surface waters in Vietnam, particularly in the center of large cities, are polluted by a large number of organic micropollutants, with households and business activities as the major sources. In addition, risk quotients (MEC/PNEC values) for nonylphenol, sulfamethoxazole, ampicillin, acetaminophen, erythromycin and clarithromycin were higher than 1, which indicates a possibility of adverse effects on aquatic ecosystems.

Probabilistic risk assessment of nitrate groundwater contamination from greenhouses in Albenga plain (Liguria, Italy) using lysimeters.

PubMed

Paladino, Ombretta; Seyedsalehi, Mahdi; Massabò, Marco

2018-09-01

The use of fertilizers in greenhouse-grown crops can pose a threat to groundwater quality and, consequently, to human beings and subterranean ecosystem, where intensive farming produces pollutants leaching. Albenga plain (Liguria, Italy) is an alluvial area of about 45km 2 historically devoted to farming. Recently the crops have evolved to greenhouses horticulture and floriculture production. In the area high levels of nitrates in groundwater have been detected. Lysimeters with three types of reconstituted soils (loamy sand, sandy clay loam and sandy loam) collected from different areas of Albenga plain were used in this study to evaluate the leaching loss of nitrate (NO 3 - ) over a period of 12weeks. Leaf lettuce (Lactuca sativa L.) was selected as a representative green-grown crop. Each of the soil samples was treated with a slow release fertilizer, simulating the real fertilizing strategy of the tillage. In order to estimate the potential risk for aquifers as well as for organisms exposed via pore water, nitrate concentrations in groundwater were evaluated by applying a simplified attenuation model to the experimental data. Results were refined and extended from comparison of single effects and exposure values (Tier I level) up to the evaluation of probabilistic distributions of exposure and related effects (Tier II, III IV levels). HHRA suggested HI >1 and about 20% probability of exceeding RfD for all the greenhouses, regardless of the soil. ERA suggested HQ>100 for all the greenhouses; 93% probability of PNEC exceedance for greenhouses containing sand clay loam. The probability of exceeding LC50 for 5% of the species was about 40% and the probability corresponding to DBQ of DEC/EC50>0.001 was >90% for all the greenhouses. The significantly high risk, related to the detected nitrate leaching loss, can be attributed to excessive and inappropriate fertigation strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

Pharmaceuticals and iodinated contrast media in a hospital wastewater: A case study to analyse their presence and characterise their environmental risk and hazard.

PubMed

Mendoza, A; Aceña, J; Pérez, S; López de Alda, M; Barceló, D; Gil, A; Valcárcel, Y

2015-07-01

This work analyses the presence of twenty-five pharmaceutical compounds belonging to seven different therapeutic groups and one iodinated contrast media (ICM) in a Spanish medium-size hospital located in the Valencia Region. Analysis of the target compounds in the hospital wastewater was performed by means of solid phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry analysis (HPLC-MS/MS). A screening level risk assessment combining the measured environmental concentrations (MECs) with dose-response data based on Predicted No Effect Concentration (PNEC) was also applied to estimate Hazard Quotients (HQs) for the compounds investigated. Additionally, the environmental hazard associated to the various compounds measured was assessed through the calculation of the Persistence, Bioaccumulation and Toxicity (PBT) Index, which categorizes compounds according to their environmentally damaging characteristics. The results of the study showed the presence of twenty-four out of the twenty-six compounds analysed at individual concentrations ranging from 5 ng L(-1) to 2 mg L(-1). The highest concentrations corresponded to the ICM iomeprol, found at levels between 424 and 2093 μg L(-1), the analgesic acetaminophen (15-44 μg L(-1)), the diuretic (DIU) furosemide (6-15 μg L(-1)), and the antibiotics (ABIs) ofloxacin and trimethoprim (2-5 μg L(-1)). The lowest levels corresponded to the anti-inflammatory propyphenazone, found at concentrations between 5 and 44 ng L(-1). Differences in terms of concentrations of the analysed compounds have been observed in all the therapeutic groups when comparing the results obtained in this and other recent studies carried out in hospitals with different characteristics from different geographical areas and in different seasons. The screening level risk assessment performed in raw water from the hospital effluent showed that the analgesics and anti-inflammatories (AAFs) acetaminophen, diclofenac, ibuprofen and naproxen, the antibiotics (ABIs) clarithromycin, ofloxacin and trimethoprim, and the β-blocker (BBL) propranolol were present at concentrations leading to HQ values higher than 10, thus indicating high risk. When applying a factor to take into account potential dilution and degradation processes, only the compound ibuprofen showed a HQ higher than 1. Likewise, the cumulative HQ or Toxic Units (TUs) calculated in the raw water for each of the therapeutic groups studied showed that these three classes of drugs were at concentrations high enough to potentially generate high risk to aquatic organisms while taking into account possible dilution and degradation processes only one of them, the AAFs can be considered to represent high risk. Finally, the environmental hazard assessment performed showed that the AAFs diclofenac and ibuprofen and the ABI clarithromycin have the highest, maximum value of 9 of PBT Index due to their inherent environmentally damaging characteristics of persistence, bioaccumulation and toxicity. The methodology followed in the present case study can be taken as a novel approach to classify and categorize pharmaceuticals on the basis of their occurrence in hospital effluents, their derived environmental risks, and their associated environmental hazard. This classification becomes important because it can be used as a model or orientation for hospitals in the process of developing environmentally sustainable policies and as an argument to justify the adoption of advanced, specific treatments for hospital effluents before being discharged into the public sewage system. Copyright © 2015 Elsevier Inc. All rights reserved.

A risk-based, product-level approach for assuring aquatic environmental safety of cleaning products in the context of sustainability: The Environmental Safety Check (ESC) scheme of the A.I.S.E. Charter for Sustainable Cleaning.

PubMed

Pickup, John Alexander; Dewaele, Joost; Furmanski, Nicola L; Kowalczyk, Agnieszka; Luijkx, Gerard Ca; Mathieu, Sophie; Stelter, Norbert

2017-01-01

Cleaning products have long been a focus of efforts to improve sustainability and assure safety for the aquatic environment when disposed of after use. The latter is addressed at ingredient level through environmental risk assessment, including in formal frameworks such as REACH. Nevertheless, in the context of programs to improve overall sustainability, stakeholders demand both environmental safety assurance and progress at product level. Current product-level approaches for aquatic toxicity (e.g., USEtox™, Critical Dilution Volume) can be seen as predominantly hazard-based. The more logical approach would be risk-based, because ecotoxicity is generally threshold-dependent and hazard-based assessment produces conflicts with risk-based learnings. The development of a risk-based approach to assess formulated products is described: the International Association for Soaps, Detergents and Maintenance Products (A.I.S.E.) Charter Environmental Safety Check (ESC), which is consistent with the scientific principles underlying REACH. This is implemented through a simple spreadsheet tool and internal database of ingredient parameters including predicted no-effect concentration (PNEC) and removal rate. A novel feature is applying market volume information for both product types and ingredients to permit a risk-based calculation. To pass the ESC check, the projected environmental safety ratio (PESR) for each ingredient as formulated and dosed (unless cleared by a published risk assessment or exempted as inherently low risk) must be less than 1. The advantages of a risk-based approach are discussed. The strengths and limitations of various possible approaches to standard-setting, product-ranking and driving continuous improvement in respect of potential ecotoxic impacts on the aquatic environment are considered. It is proposed that as ecotoxicity is generally accepted to be threshold-dependent, with no effect below the threshold, the most constructive approach to continuous improvement of sustainability with regard to ecotoxicity is to focus efforts on instances where the safety margins for ingredients as used in specific products are narrow. This necessitates a risk-based approach. Integr Environ Assess Manag 2017;13:127-138. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

RIFM fragrance ingredient safety assessment dihydro-β-terpinyl acetate, CAS Registry Number 26252-11-9.

PubMed

Api, A M; Belsito, D; Botelho, D; Browne, D; Bruze, M; Burton, G A; Buschmann, J; Dagli, M L; Date, M; Dekant, W; Deodhar, C; Francis, M; Fryer, A D; Joshi, K; La Cava, S; Lapczynski, A; Liebler, D C; O'Brien, D; Parakhia, R; Patel, A; Penning, T M; Ritacco, G; Romine, J; Salvito, D; Schultz, T W; Sipes, I G; Thakkar, Y; Theophilus, E H; Tiethof, A K; Tokura, Y; Tsang, S; Wahler, J

2018-05-01

The use of this material under current conditions is supported by existing information. The material (dihydro-β-terpinyl acetate) was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data from the read across analog menthyl acetate (1α,2β,5α) (CAS # 89-48-5) show that dihydro-β- terpinyl acetate is not genotoxic nor does it have skin sensitization potential. The repeated dose, reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (0.03, 0.03 mg/kg/day and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoint was completed based on UV spectra. The environmental endpoints were evaluated, dihydro-β-terpinyl acetate was found not to be PBT as per the IFRA Environmental Standards and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC) are <1. Copyright © 2018 Elsevier Ltd. All rights reserved.

River export of triclosan from land to sea: A global modelling approach.

PubMed

van Wijnen, Jikke; Ragas, Ad M J; Kroeze, Carolien

2018-04-15

Triclosan (TCS) is an antibacterial agent that is added to commonly used personal care products. Emitted to the aquatic environment in large quantities, it poses a potential threat to aquatic organisms. Triclosan enters the aquatic environment mainly through sewage effluent. We developed a global, spatially explicit model, the Global TCS model, to simulate triclosan transport by rivers to coastal areas. With this model we analysed annual, basin-wide triclosan export for the year 2000 and two future scenarios for the year 2050. Our analyses for 2000 indicate that triclosan export to coastal areas in Western Europe, Southeast Asia and the East Coast of the USA is higher than in the rest of the world. For future scenarios, the Global TCS model predicts an increase in river export of triclosan in Southeast Asia and a small decrease in Europe. The number of rivers with an annual average triclosan concentration at the river mouth that exceeds a PNEC of 26.2ng/L is projected to double between 2000 and 2050. This increase is most prominent in Southeast Asia, as a result of fast population growth, increasing urbanisation and increasing numbers of people connected to sewerage systems with poor wastewater treatment. Predicted triclosan loads correspond reasonably well with measured values. However, basin-specific predictions have considerable uncertainty due to lacking knowledge and location-specific data on the processes determining the fate of triclosan in river water, e.g. sorption, degradation and sedimentation. Additional research on the fate of triclosan in river systems is therefore recommended. We developed a global spatially explicit model to simulate triclosan export by rivers to coastal seas. For two future scenarios this Global TCS model projects an increase in river export of triclosan to several seas around the world. Copyright © 2017 Elsevier B.V. All rights reserved.

[Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (dipnech) - an overview of the cases diagnosed at the department of thoracic surgery in the years 2010-2014].

PubMed

Stefański, Mariusz; Bruliński, Krzysztof; Stefańska, Marianna

Pulmonary neuroendocrine cells (PNEC) are present in the normal lungs with the incidence of 1 in 2500 epithelial cells. They usually proliferate in the presence of reactive processes related to inflammation and fibrosis of the lung parenchyma. The division of pulmonary neuroendocrine cell hyperplasia proposed by Travis et al. additionally distinguished diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) or proliferation that occurs in people without reactive hyperplasia risk factors. The confirmation of the DIPNECH diagnosis requires staining of biopsy specimens using the immunohistochemical technique for neuroendocrine markers. The aim of this study is to overview the cases of 5 patients in whom the histopathological DIPNECH diagnosis was made in the process of invasive diagnostics performed at the Department of Thoracic Surgery. The aim of the study is to evaluate typical clinical, functional, radiological and histopathological features of this rare disease syndrome. In the period from April 2010 to June 2014, five patients with lesions in the lungs were subjected to invasive diagnostics. Histopathological and immunohistochemical examinations of the collected specimens were used to make the DIPNECH diagnosis in these patients. The natural history of the disease was traced based on a 5-year follow-up in one of the patients. In addition, we analyzed the literature with regard to the described cases. Thanks to the early diagnosis of non-specific lesions in the lungs, typical carcinoid which develops on the basis of discussed DIPNECH, was found in the resected material in two out of five operated patients. The accurate diagnosis of DIPNECH allows for the implementation of appropriate treatment and channels further management of the patient into the right direction.

Individual Effect-Site Concentrations of Propofol are Similar at Loss of Consciousness and at Awakening

PubMed Central

Iwakiri, Hiroko; Nishihara, Noboru; Nagata, Osamu; Matsukawa, Takashi; Ozaki, Makoto; Sessler, Daniel I.

2005-01-01

Reported effect-site concentrations of propofol at loss of consciousness and recovery of consciousness vary widely. Thus, no single concentration based on a population average will prove optimal for individual patients. We therefore tested the hypothesis that individual propofol effect-site concentrations at loss and return of consciousness are similar. Propofol effect-site concentrations at loss and recovery of consciousness were estimated with a target-control infusion system in 20 adults. Propofol effect-site concentrations were gradually increased until the volunteers lost consciousness (no response to verbal stimuli); unconsciousness was maintained for 15 minutes, and the volunteers were then awakened. This protocol was repeated three times in each volunteer. Our major outcomes were the concentration producing unconsciousness and the relationship between the estimated effect-site concentrations at loss and recovery of consciousness. The target effect-site propofol concentration was 2.0 ± 0.9 at loss of consciousness and 1.8 ± 0.7 at return of consciousness (P < 0.001). The average difference between individual effect-site concentrations at return and loss of consciousness was only 0.17 ± 0.32 μg/mL (95% confidence interval for the difference 0.09 to 0.25 μg/mL). Our results thus suggest that individual titration to loss of consciousness is an alternative to dosing propofol on the basis of average population requirements. Implications Propofol can be titrated to the concentration that produces consciousness in individual patients. Provided that the propofol effect-site concentration does not much exceed the concentration initially required to produce unconsciousness, patients can be expected to awaken quickly upon completion of the procedure. PMID:15616062

Effective concentration-based serum pharmacodynamics for antifungal azoles in a murine model of disseminated Candida albicans infection.

PubMed

Maki, Katsuyuki; Kaneko, Shuji

2013-12-01

An assessment of the effective in vivo concentrations of antifungal drugs is important in determining their pharmacodynamics, and therefore, their optimal dosage regimen. Here we establish the effective in vivo concentration-based pharmacodynamics of three azole antifungal drugs (fluconazole, itraconazole, and ketoconazole) in a murine model of disseminated Candida albicans infection. A key feature of this study was the use of a measure of mycelial (m) growth rather than of yeast growth, and pooled mouse sera rather than synthetic media as a growth medium, for determining the minimum inhibitory concentrations (MICs) of azoles for C. albicans (denoted serum mMICs). The serum mMIC assay was then used to measure antifungal concentrations and effects as serum antifungal titers in the serum of treated mice. Both serum mMIC and sub-mMIC values reflected the effective in vivo serum concentrations. Supra-mMIC and mMIC effects exhibited equivalent efficacies and were concentration-independent, while the sub-mMIC effect was concentration-dependent. Following administration of the minimum drug dosage that inhibited an increase in mouse kidney fungal burden, the duration periods of these effects were similar for all drugs tested. The average duration of either the mMIC effect including the supra-mMIC effect, the sub-mMIC effect, or the post-antifungal effect (PAFE) were 6.9, 6.5 and 10.6 h, respectively. Our study suggests that the area under the curve for serum drug concentration versus time, between the serum mMIC and the sub-mMIC, and exposure time above the serum sub-mMIC after the mMIC effect, are major pharmacodynamic parameters. These findings have important implications for effective concentration-based pharmacodynamics of fungal infections treated with azoles.

Embryotoxic effects of environmental chemicals: tests with the South African clawed toad (Xenopus laevis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumpert, K.

1987-06-01

In the course of the investigations reported below, it was shown that p-chloroaniline has a lethal effect on the embryos of Xenopus laevis at a concentration of 100 ppm and is development inhibiting (teratogenic) at concentrations of 1 and 10 ppm, respectively. In the case of aniline, a significant development-inhibiting effect was observed at a concentration as low as 1 ppm. A toxic effect was caused by concentrations between 30 and 40 ppm during embryogenesis and by concentrations above 40 ppm during larval development. A very conspicuous finding was an inhibiting effect of 20 to 40 ppm aniline on pigmentationmore » during embryogenesis and of a concentration as low as 1 ppm on the body size of the young toads. In the case of potassium dichromate, it was possible to barely detect a weak development-inhibiting effect during embryogenesis but no development-retarding effect during larval development. Toxic effects of potassium dichromate occurred during embryogenesis at concentrations of 5 and 7.5 ppm and during the larval development at concentrations above 10 ppm. Sodium dodecylbenzenesulfonic acid at a concentration of 50 ppm was found to have such a strong embryolethal effect that 80% of the eggs showed no cell division at all and the remaining 20% developed to only the bicellular stage. A teratogenic effect of this substance was not observed. Phenol, too, was found to be toxic at a concentration of 50 ppm; in contrast to sodium dodecylbenzenesulfonic acid, however, it did not show any lethal effect on the embryos but it did on the tadpoles, mainly in the first stages of larval development. Lower concentrations of phenol (5 and 10 ppm) had a nonsignificant inhibiting effect on the growth of the larvae. A teratogenic effect of phenol was not detected.« less

[Allelopathy of Andrographis paniculata vegetative].

PubMed

Li, Ming; Zhou, Xiao-Yan; Lu, Zhan-Hong

2010-12-01

Andrographis paniculata at vegetative stage were analyzed for the allelopathic effect on cabbage (Brassica chinensis), Radis (Raphanus sativus), and Desmodium styracifolium, and provided the theory reference for their application of compounding planting pattern in practice. Water extracts of Andrographis paniculata root, stem and leaf were used to dispose Brassica chinensis, Raphanus sativus and Desmodium styracifolium seeds, young seedlings. There were allelopathic effect of water extracts of Andrographis paniculata on seed germination of Brassica chinensis, Raphanus sativus and Desmodium styracifolium, but there were difference on allelopathic effect. The suppression effects of roots on seed germination rates of Brassica chinensis showed more significantly, the stems and leaves of Andrographis paniculata on the allelopathic effects on Brassica chinensis seed germination rate index was also significantly higher than the other two receptors plants. Under the treating condition of root, stem and leaf aqueous extracts of Andrographis paniculata, the root growth of receptors seeding mostly showed inhibition effect. Under low concentrations treated. The effects on the seedlings height of Raphanus sativus and Desmodium styracifolium showed the results in which low concentration promoted and high concentration inhibited, and with increasing concentration increased the promotion or inhibition effects. But in the measured concentration range, the effects on the seedlings height of Brassica chinensis were showed promote effect. Within the testing concentration range, water extracts of Andrographis paniculata on allelopathic effects of cabbage (Brassica chinensis), Radis (Raphanus sativus) and Desmodium styracifolium showed allelopathic effect, and roughly showed inhibiti effect. However, showed different effect in which high concentration inhibitied and low concentration promoted to different receptor.

Boric acid ovicidal trap for the management of Aedes species.

PubMed

Bhami, L Charlet; Das, S Sam Manohar

2015-06-01

The use of low concentrations of boric acid as a potential and effective control agent for the eggs and immature stages of Aedes aegypti L. and Aedes albopictus Skuse (Diptera: Culicidae) is found to be safe and effective as compared to synthetic chemical insecticides. The study aims to determine the ovicidal concentration of boric acid, its effective concentration for oviposition attraction and the larval mortality concentration for Ae. aegypti and Ae. albopictus. The ovicidal concentration of boric acid was determined by incubating the eggs in different concentrations of boric acid (0.1, 0.25, 0.5, 0.75 and 1%). Different dilutions of boric acid were taken in the oviposition cup and the ovicidal concentration, effective concentration for oviposition attraction and the mean survival/mortality rate of III and IV instar Ae. aegypti and Ae. albopictus larvae were determined. The ovicidal concentration of boric acid for 100% mortality in Aedes sp eggs is 1%. Effective concentration for the oviposition attraction is 0.5%. At 1% concentration, larvae of both the species died within 24 h. Boric acid is less toxic compared to different pesticides, and in low concentrations, it attracts the ovipositing female Aedes sp as well as fertile males. Dilute boric acid solution is an effective ovitrap since the eggs laid by mosquitoes either die or the larvae that hatch out from them do not survive in boric acid. Boric acid kills the males that come in contact with the solution, which are attracted to the trap by the females hovering around.

Areal distribution and concentration of contaminants of concern in surficial streambed and lakebed sediments, Lake St. Clair and tributaries, Michigan, 1990-2003

USGS Publications Warehouse

Rachol, Cynthia M.; Button, Daniel T.

2006-01-01

As part of the Lake St. Clair Regional Monitoring Project, the U.S. Geological Survey evaluated data collected from surficial streambed and lakebed sediments in the Lake Erie-Lake St. Clair drainages. This study incorporates data collected from 1990 through 2003 and focuses primarily on the U.S. part of the Lake St. Clair Basin, including Lake St. Clair, the St. Clair River, and tributaries to Lake St. Clair. Comparable data from the Canadian part of the study area are included where available. The data are compiled into 4 chemical classes and consist of 21 compounds. The data are compared to effects-based sediment-quality guidelines, where the Threshold Effect Level and Lowest Effect Level represent concentrations below which adverse effects on biota are not expected and the Probable Effect Level and Severe Effect Level represent concentrations above which adverse effects on biota are expected to be frequent.Maps in the report show the spatial distribution of the sampling locations and illustrate the concentrations relative to the selected sediment-quality guidelines. These maps indicate that sediment samples from certain areas routinely had contaminant concentrations greater than the Threshold Effect Concentration or Lowest Effect Level. These locations are the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Big Beaver Creek, Red Run, and Paint Creek. Maps also indicated areas that routinely contained sediment contaminant concentrations that were greater than the Probable Effect Concentration or Severe Effect Level. These locations include the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Red Run, within direct tributaries along Lake St. Clair and in marinas within the lake, and within the Clinton River headwaters in Oakland County.Although most samples collected within Lake St. Clair were from sites adjacent to the mouths of its tributaries, samples analyzed for trace-element concentrations were collected throughout the lake. The distribution of trace-element concentrations corresponded well with the results of a two-dimensional hydrodynamic model of flow patterns from the Clinton River into Lake St. Clair. The model was developed independent from the bed sediment analysis described in this report; yet it showed a zone of deposition for outflow from the Clinton River into Lake St. Clair that corresponded well with the spatial distribution of trace-element concentrations. This zone runs along the western shoreline of Lake St. Clair from L'Anse Creuse Bay to St. Clair Shores, Michigan and is reflected in the samples analyzed for mercury and cadmium.Statistical summaries of the concentration data are presented for most contaminants, and selected statistics are compared to effects-based sediment-quality guidelines. Summaries were not computed for dieldrin, chlordane, hexachlorocyclohexane, lindane, and mirex because insufficient data are available for these contaminants. A statistical comparison showed that the median concentration for hexachlorobenzene, anthracene, benz[a]anthracene, chrysene, and pyrene are greater than the Threshold Effect Concentration or Lowest Effect Level.Probable Effect Concentration Quotients provide a mechanism for comparing the concentrations of contaminant mixtures against effects-based biota data. Probable Effect Concentration Quotients were calculated for individual samples and compared to effects-based toxicity ranges. The toxicity-range categories used in this study were nontoxic (quotients < 0.5) and toxic (quotients > 0.5). Of the 546 individual samples for which Probable Effect Concentration Quotients were calculated, 469 (86 percent) were categorized as being nontoxic and 77 (14 percent) were categorized as being toxic. Bed-sediment samples with toxic Probable Effect Concentration Quotients were collected from Paint Creek, Galloway Creek, the main stem of the Clinton River, Big Beaver Creek, Red Run, Clinton River towards the mouth, Lake St. Clair along the western shore, and the St. Clair River near Sarnia.

Benzocaine as an anesthetic for striped bass

USGS Publications Warehouse

Gilderhus, Philip A.; Lemm, Carol A.; Woods, L. Curry

1991-01-01

Benzocaine was tested as an anesthetic on juvenile and mature adult striped bass (Morone saxatilis ). Concentrations of 55 mg/L at 22 degree C to 80 mg/L at 11 degree C effectively anesthetized fish in about 3 min. Recovery was more rapid as temperature increased. Fish survived concentrations of twice the effective concentration and exposure times up to 60 min at the effective concentration. Striped bass required higher concentrations for anesthetization than had been previously demonstrated for salmonid fishes, but safety margins for both concentration and exposure time were wider than for the salmonids.

Glucose, fructose and sucrose increase the solubility of protein-tannin complexes and at high concentration, glucose and sucrose interfere with bisulphite bleaching of wine pigments.

PubMed

Harbertson, James F; Yuan, Chunlong; Mireles, Maria S; Hanlin, Rachel L; Downey, Mark O

2013-05-01

Wines were modified with increasing sugar concentrations and decreasing tannin concentrations and analysed by a combination of protein precipitation and bisulphite bleaching. Increasing sugar concentration decreased the precipitation of tannin and protein-precipitable polymeric pigments (PPP). The use of a hydrogen bond disruptor (urea) to reduce protein-tannin and protein-pigment complex formation showed that the effect of sugar concentration occurred by increasing the solubility of the tannin-protein complex, not by interfering with protein-tannin complex formation. By increasing the solubility of pigment-protein complexes, non-protein-precipitable polymeric pigments (nPPP) appeared to increase. There was also an increase in total polymeric pigments at each tannin concentration with increasing glucose and sucrose concentration, indicating that sugar concentration might also affect bisulphite bleaching of wine pigments. While a significant effect of sugar concentration on tannin-protein complex solubility was observed, these effects were greatest at sugar concentrations far in excess of normal wine making conditions. Under normal wine making conditions, sugar concentration will have a negligible effect on protein-precipitable tannin, PPP and nPPP concentrations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms.

PubMed

Aristi, I; Casellas, M; Elosegi, A; Insa, S; Petrovic, M; Sabater, S; Acuña, V

2016-05-01

Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the experiment. Our results show that contaminants with a subsidy effect can alleviate the effects of toxic contaminants, and that long-term experiments are required to detect stress effects of emerging contaminants at environmentally relevant concentrations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effects of short-term niacin treatment on plasma lipoprotein concentrations in African green monkeys (Chlorocebus aethiops).

PubMed

Chauke, Chesa G; Arieff, Zainunisha; Kaur, Mandeep; Seier, Jurgen V

2014-02-01

Niacin is the most effective drug available for raising levels of high-density lipoprotein (HDL) cholesterol. To evaluate its effects on plasma lipid concentrations, the authors administered a low dose of niacin to healthy, adult, female African green monkeys for 3 months. In the treated monkeys, low-density lipoprotein cholesterol concentrations decreased by 43% from baseline, whereas concentrations of HDL cholesterol and apolipoprotein A-I increased by 49% and 34%, respectively. The results suggest that in this primate model, a low dose of niacin can effectively increase concentrations of HDL cholesterol.

The optimal atmospheric CO2 concentration for the growth of winter wheat (Triticum aestivum).

PubMed

Xu, Ming

2015-07-20

This study examined the optimal atmospheric CO2 concentration of the CO2 fertilization effect on the growth of winter wheat with growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, and 1200 ppm respectively. I found that initial increase in atmospheric CO2 concentration dramatically enhanced winter wheat growth through the CO2 fertilization effect. However, this CO2 fertilization effect was substantially compromised with further increase in CO2 concentration, demonstrating an optimal CO2 concentration of 889.6, 909.4, and 894.2 ppm for aboveground, belowground, and total biomass, respectively, and 967.8 ppm for leaf photosynthesis. Also, high CO2 concentrations exceeding the optima not only reduced leaf stomatal density, length and conductance, but also changed the spatial distribution pattern of stomata on leaves. In addition, high CO2 concentration also decreased the maximum carboxylation rate (Vc(max)) and the maximum electron transport rate (J(max)) of leaf photosynthesis. However, the high CO2 concentration had little effect on leaf length and plant height. The optimal CO2 fertilization effect found in this study can be used as an indicator in selecting and breeding new wheat strains in adapting to future high atmospheric CO2 concentrations and climate change. Copyright © 2015. Published by Elsevier GmbH.

Effect of lactose concentration on batch production of ethanol from cheese whey using Candida pseudotropicalis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghaly, A.E.; El-Taweel, A.A.

1995-07-01

The effect of lactose concentration on growth of Candida pseudotropicalis and ethanol production from cheese whey under batch conditions was investigated. Four initial lactose concentrations ranging from 50 to 200 g/L (5 to 20% wt/vol) were used. High concentration of lactose had an inhibitory effect on the specific growth rate, lactose utilization rate, and ethanol production rate. The maximum cell concentration was influenced by the initial substrate concentration as well as ethanol concentration. Inhibition of ethanol production was more pronounced at higher initial lactose concentrations. The maximum ethanol yield (96.6% of the theoretical yield) was achieved with the 100 g/Lmore » initial substrate concentration. The results indicated that pH control during alcohol fermentation of cheese whey is not necessary. 41 refs., 12 figs., 1 tab.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orton, Frances; Ermler, Sibylle; Kugathas, Subramaniam

Many xenobiotics have been identified as in vitro androgen receptor (AR) antagonists, but information about their ability to produce combined effects at low concentrations is missing. Such data can reveal whether joint effects at the receptor are induced at low levels and may support the prioritisation of in vivo evaluations and provide orientations for the grouping of anti-androgens in cumulative risk assessment. Combinations of 30 AR antagonists from a wide range of sources and exposure routes (pesticides, antioxidants, parabens, UV-filters, synthetic musks, bisphenol-A, benzo(a)pyrene, perfluorooctane sulfonate and pentabromodiphenyl ether) were tested using a reporter gene assay (MDA-kb2). Chemicals were combinedmore » at three mixture ratios, equivalent to single components' effect concentrations that inhibit the action of dihydrotesterone by 1%, 10% or 20%. Concentration addition (CA) and independent action were used to calculate additivity expectations. We observed complete suppression of dihydrotestosterone effects when chemicals were combined at individual concentrations eliciting 1%, 10% or 20% AR antagonistic effect. Due to the large number of mixture components, the combined AR antagonistic effects occurred at very low concentrations of individual mixture components. CA slightly underestimated the combined effects at all mixture ratios. In conclusion, large numbers of AR antagonists from a wide variety of sources and exposure routes have the ability of acting together at the receptor to produce joint effects at very low concentrations. Significant mixture effects are observed when chemicals are combined at concentrations that individually do not induce observable AR antagonistic effects. Cumulative risk assessment for AR antagonists should apply grouping criteria based on effects where data are available, rather than on criteria of chemical similarity. - Highlights: • Mixtures of AR antagonists at low individual concentrations cause complete inhibition. • Concentration addition was an appropriate prediction model for observed effects. • Risk assessment for AR antagonists should use grouping criteria based on effects.« less

Implicit Versus Explicit Applications of the Tissue Residue Approach, Oral Presentation

EPA Science Inventory

Toxic effect models based on the relationship of toxic effects to chemical concentrations within receptor organism tissues can often be reformulated to describe the relationship of toxic effects to exposure concentrations without actual specification of the tissue concentrations....

The Catalytic Function of Enzymes.

ERIC Educational Resources Information Center

Splittgerber, Allan G.

1985-01-01

Discusses: structure of the enzyme molecule; active site; reaction mechanism; transition state; factors affecting enzyme reaction rates, concentration of enzyme; concentration of substrate; product concentration; temperature effects and pH effects; factors causing a lowering of activation energy; proximity and orientation effects; substrate strain…

Effects of ammonium sulfate and sodium chloride concentration on PEG/protein liquid-liquid phase separation.

PubMed

Dumetz, André C; Lewus, Rachael A; Lenhoff, Abraham M; Kaler, Eric W

2008-09-16

When added to protein solutions, poly(ethylene glycol) (PEG) creates an effective attraction between protein molecules due to depletion forces. This effect has been widely used to crystallize proteins, and PEG is among the most successful crystallization agents in current use. However, PEG is almost always used in combination with a salt at either low or relatively high concentrations. Here the effects of sodium chloride and ammonium sulfate concentration on PEG 8000/ovalbumin liquid-liquid (L-L) phase separation are investigated. At low salt the L-L phase separation occurs at decreasing protein concentration with increasing salt concentration, presumably due to repulsive electrostatic interactions between proteins. At high salt concentration, the behavior depends on the nature of the salt. Sodium chloride has little effect on the L-L phase separation, but ammonium sulfate decreases the protein concentration at which the L-L phase separation occurs. This trend is attributed to the effects of critical fluctuations on depletion forces. The implications of these results for designing solution conditions optimal for protein crystallization are discussed.

Concentration effects of grape seed extracts in anti-oral cancer cells involving differential apoptosis, oxidative stress, and DNA damage.

PubMed

Yen, Ching-Yu; Hou, Ming-Feng; Yang, Zhi-Wen; Tang, Jen-Yang; Li, Kun-Tzu; Huang, Hurng-Wern; Huang, Yu-Hsuan; Lee, Sheng-Yang; Fu, Tzu-Fun; Hsieh, Che-Yu; Chen, Bing-Hung; Chang, Hsueh-Wei

2015-03-29

Grape seeds extract (GSE) is a famous health food supplement for its antioxidant property. Different concentrations of GSE may have different impacts on cellular oxidative/reduction homeostasis. Antiproliferative effect of GSE has been reported in many cancers but rarely in oral cancer. The aim of this study is to examine the antioral cancer effects of different concentrations of GSE in terms of cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial function, and DNA damage. High concentrations (50-400 μg/ml) of GSE dose-responsively inhibited proliferation of oral cancer Ca9-22 cells but low concentrations (1-10 μg/ml) of GSE showed a mild effect in a MTS assay. For apoptosis analyses, subG1 population and annexin V intensity in high concentrations of GSE-treated Ca9-22 cells was increased but less so at low concentrations. ROS generation and mitochondrial depolarization increased dose-responsively at high concentrations but showed minor changes at low concentrations of GSE in Ca9-22 cells. Additionally, high concentrations of GSE dose-responsively induced more γH2AX-based DNA damage than low concentrations. Differential concentrations of GSE may have a differentially antiproliferative function against oral cancer cells via differential apoptosis, oxidative stress and DNA damage.

Calcium in the control of renin release.

PubMed

Park, C S; Malvin, R L

1978-07-01

The effect of Ca concentrations in the incubation medium and of estimated intracellular Ca concentrations on renin release was examined with use of pig renal cortical slices. In addition, the Ca requirement for the epinephrine stimulatory effect and for the ouabain inhibitory action on renin release was also tested. In mediums containing 5.9 mM K, variations in Ca concentration had no effect on renin release. In contrast, when the K concentration was 59 mM, a significant inhibition of renin release was attained with all concentrations of calcium. The inhibition of renin release in high K mediums by Ca was attributed to an increase in the intracellular Ca concentration. In addition, both the stimulatory effect of epinephrine and the inhibitory effect of ouabain on renin release required Ca in the medium. These results support the hypothesis that the control of renin secretion is mediated, in part, by changes in the intracellular concentration of Ca, most likely in the juxtaglomerular cells.

Push-Pull Effects of Three Plant Secondary Metabolites on Oviposition of the Potato Tuber Moth, Phthorimaea operculella

PubMed Central

Ma, Y.F.; Xiao, C.

2013-01-01

The push-pull effects of three plant secondary metabolites, azadirachtin, eucalyptol, and heptanal, on the oviposition choices of potato tubers by the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) were tested in the laboratory. Azadirachtin at concentrations from 1.5 to 12 mg/L had a significant repellent effect on oviposition. Eucalyptol at concentrations from 3 to 12 mg/L promoted oviposition. Heptanal promoted oviposition at low concentrations from 0.1875 to 3.0 mg/L but repelled it at higher concentrations from 12 to 24 mg/L. The combination of azadirachtin (12 mg/L) with eucalyptol (3.0 mg/L) resulted in a significant pushpull effect of 56.3% on oviposition. The average maximum push-pull effects occurred with the combinations of azadirachtin with heptanal (12 and 0.375 mg/L, respectively; 38.7% push-pull effect), heptanal with eucalyptol (12 and 6 mg/L, respectively; 31.4% push-pull effect), and heptanal (high concentration) with heptanal (low concentration) (12.0 and 0.375 mg/L, respectively; 25% push-pull effect). PMID:24786822

Controlled vaporized cannabis, with and without alcohol: subjective effects and oral fluid-blood cannabinoid relationships.

PubMed

Hartman, Rebecca L; Brown, Timothy L; Milavetz, Gary; Spurgin, Andrew; Gorelick, David A; Gaffney, Gary; Huestis, Marilyn A

2016-07-01

Vaporized cannabis and concurrent cannabis and alcohol intake are commonplace. We evaluated the subjective effects of cannabis, with and without alcohol, relative to blood and oral fluid (OF, advantageous for cannabis exposure screening) cannabinoid concentrations and OF/blood and OF/plasma vaporized-cannabinoid relationships. Healthy adult occasional-to-moderate cannabis smokers received a vaporized placebo or active cannabis (2.9% and 6.7% Δ(9) -tetrahydrocannabinol, THC) with or without oral low-dose alcohol (~0.065g/210L peak breath alcohol concentration [BrAC]) in a within-subjects design. Blood and OF were collected up to 8.3 h post-dose and subjective effects measured at matched time points with visual-analogue scales and 5-point Likert scales. Linear mixed models evaluated subjective effects by THC concentration, BrAC, and interactions. Effects by time point were evaluated by dose-wise analysis of variance (ANOVA). OF versus blood or plasma cannabinoid ratios and correlations were evaluated in paired-positive specimens. Nineteen participants (13 men) completed the study. Blood THC concentration or BrAC significantly associated with subjective effects including 'high', while OF contamination prevented significant OF concentration associations <1.4 h post-dose. Subjective effects persisted through 3.3-4.3 h, with alcohol potentiating the duration of the cannabis effects. Effect-versus-THC concentration and effect-versus-alcohol concentration hystereses were counterclockwise and clockwise, respectively. OF/blood and OF/plasma THC significantly correlated (all Spearman r≥0.71), but variability was high. Vaporized cannabis subjective effects were similar to those previously reported after smoking, with duration extended by concurrent alcohol. Cannabis intake was identified by OF testing, but OF concentration variability limited interpretation. Blood THC concentrations were more consistent across subjects and more accurate at predicting cannabis' subjective effects. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

[Reducing cadmium content of rice grains by means of flooding and a few problems].

PubMed

Kawasaki, Akira; Arao, Tomohito; Ishikawa, Satoru

2012-01-01

The effects of water management in rice paddies on the levels of cadmium (Cd) and arsenic (As) in Japanese rice grains were tested. In order to reduce the Cd concentration in rice grains, flooding for 3 weeks before and after heading was most effective, but this treatment increased As concentration considerably. Aerobic treatment was effective in reducing As concentration in rice grains, but increased Cd concentration markedly. In the pot experiment, flooding treatment after heading was more effective than flooding treatment before heading in reducing both Cd and As concentrations in rice grains. The concentration of dimethylarsinic acid (DMA) in rice grains was very low under aerobic conditions, but increased in the continuous-flooding treatment. In the field experiment, the grain As concentration in the case of flooding for 3 weeks before and after heading was higher than that in the case of intermittent irrigation. The ratios of DMA to the total As concentration were 3-52% in the pot experiment and 7-13% in the field experiment.

Measured and Modeled Toxicokinetics in Cultured Fish Cells and Application to In Vitro - In Vivo Toxicity Extrapolation

PubMed Central

Stadnicka-Michalak, Julita; Tanneberger, Katrin; Schirmer, Kristin; Ashauer, Roman

2014-01-01

Effect concentrations in the toxicity assessment of chemicals with fish and fish cells are generally based on external exposure concentrations. External concentrations as dose metrics, may, however, hamper interpretation and extrapolation of toxicological effects because it is the internal concentration that gives rise to the biological effective dose. Thus, we need to understand the relationship between the external and internal concentrations of chemicals. The objectives of this study were to: (i) elucidate the time-course of the concentration of chemicals with a wide range of physicochemical properties in the compartments of an in vitro test system, (ii) derive a predictive model for toxicokinetics in the in vitro test system, (iii) test the hypothesis that internal effect concentrations in fish (in vivo) and fish cell lines (in vitro) correlate, and (iv) develop a quantitative in vitro to in vivo toxicity extrapolation method for fish acute toxicity. To achieve these goals, time-dependent amounts of organic chemicals were measured in medium, cells (RTgill-W1) and the plastic of exposure wells. Then, the relation between uptake, elimination rate constants, and log KOW was investigated for cells in order to develop a toxicokinetic model. This model was used to predict internal effect concentrations in cells, which were compared with internal effect concentrations in fish gills predicted by a Physiologically Based Toxicokinetic model. Our model could predict concentrations of non-volatile organic chemicals with log KOW between 0.5 and 7 in cells. The correlation of the log ratio of internal effect concentrations in fish gills and the fish gill cell line with the log KOW was significant (r>0.85, p = 0.0008, F-test). This ratio can be predicted from the log KOW of the chemical (77% of variance explained), comprising a promising model to predict lethal effects on fish based on in vitro data. PMID:24647349

Effects of ionic concentration gradient on electroosmotic flow mixing in a microchannel.

PubMed

Peng, Ran; Li, Dongqing

2015-02-15

Effects of ionic concentration gradient on electroosmotic flow (EOF) mixing of one stream of a high concentration electrolyte solution with a stream of a low concentration electrolyte solution in a microchannel are investigated numerically. The concentration field, flow field and electric field are strongly coupled via concentration dependent zeta potential, dielectric constant and electric conductivity. The results show that the electric field and the flow velocity are non-uniform when the concentration dependence of these parameters is taken into consideration. It is also found that when the ionic concentration of the electrolyte solution is higher than 1M, the electrolyte solution essentially cannot enter the channel due to the extremely low electroosmotic flow mobility. The effects of the concentration dependence of zeta potential, dielectric constant and electric conductivity on electroosmotic flow mixing are studied. Copyright © 2014 Elsevier Inc. All rights reserved.

High concentrations of protein test substances may have non-toxic effects on Daphnia magna: implications for regulatory study designs and ecological risk assessments for GM crops.

PubMed

Raybould, Alan; Burns, Andrea; Hamer, Mick

2014-01-01

Laboratory testing for possible adverse effects of insecticidal proteins on non-target organisms (NTOs) is an important part of many ecological risk assessments for regulatory decision-making about the cultivation of insect-resistant genetically modified (IRGM) crops. To increase confidence in the risk assessments, regulatory guidelines for effects testing specify that representative surrogate species for NTOs are exposed to concentrations of insecticidal proteins that are in excess of worst-case predicted exposures in the field. High concentrations in effects tests are achieved by using protein test substances produced in microbes, such as Escherichia coli. In a study that exposed Daphnia magna to a single high concentration of a microbial test substance containing Vip3Aa20, the insecticidal protein in MIR162 maize, small reductions in growth were observed. These effects were surprising as many other studies strongly suggest that the activity of Vip3Aa20 is limited to Lepidoptera. A plausible explanation for the effect on growth is that high concentrations of test substance have a non-toxic effect on Daphnia, perhaps by reducing its feeding rate. A follow-up study tested that hypothesis by exposing D. magna to several concentrations of Vip3Aa20, and a high concentration of a non-toxic protein, bovine serum albumin (BSA). Vip3Aa20 and BSA had sporadic effects on the reproduction and growth of D. magna. The pattern of the effects suggests that they result from non-toxic effects of high concentrations of protein, and not from toxicity. The implications of these results for regulatory NTO effects testing and ERA of IRGM crops are discussed.

The effect of beaver ponds on water quality in rural coastal plain streams

USGS Publications Warehouse

Bason, Christopher W.; Kroes, Daniel; Brinson, Mark M.

2017-01-01

We compared water-quality effects of 13 beaver ponds on adjacent free-flowing control reaches in the Coastal Plain of rural North Carolina. We measured concentrations of nitrate, ammonium, soluble reactive phosphorus (SRP), and suspended sediment (SS) upstream and downstream of paired ponds and control reaches. Nitrate and SS concentrations decreased, ammonium concentrations increased, and SRP concentrations were unaffected downstream of the ponds and relative to the control reaches. The pond effect on nitrate concentration was a reduction of 112 ± 55 μg-N/L (19%) compared to a control-reach—influenced reduction of 28 ± 17 μg-N/L. The pond effect on ammonium concentration was an increase of 9.47 ± 10.9 μg-N/L (59%) compared to the control-reach—influenced reduction of 1.49 ± 1.37 μg-N/L. The pond effect on SS concentration was a decrease of 3.41 ± 1.68 mg/L (40%) compared to a control-reach—influenced increase of 0.56 ± 0.27 mg/L. Ponds on lower-order streams reduced nitrate concentrations by greater amounts compared to those in higher-order streams. Older ponds reduced SS concentrations by greater amounts compared to younger ponds. The findings of this study indicate that beaver ponds provide water-quality benefits to rural Coastal Plain streams by reducing concentrations of nitrate and suspended sediment.

Synergistic effect of sevoflurane and isoflurane on inhibition of the adult-type muscle nicotinic acetylcholine receptor by rocuronium.

PubMed

Liu, Li; Li, Wei; Wei, Ke; Cao, Jun; Luo, Jie; Wang, Bin; Min, Su

2013-06-01

Inhaled anesthetics increase the incidence of postoperative residual neuromuscular blockade, and the mechanism is still unclear. We have investigated the synergistic effect of low-concentration inhaled anesthetics and rocuronium on inhibition of the inward current of the adult-type muscle nicotinic acetylcholine receptor (ε-nAChR). Adult-type mouse muscle ε-nAChR was expressed in HEK293 cells by liposome transfection. The inward current of the ε-nAChR was activated by use of 10 μmol/L acetylcholine alone or in combination with different concentrations of sevoflurane, isoflurane, or rocuronium. The concentration-response curves of five cells were constructed, and the data yielded the 5, 25, and 50 % inhibitory concentrations (IC5, IC25, and IC50, respectively) for single-drug application. Subsequently, the functional channels were perfused by adding 0.5 IC5 of either sevoflurane or isoflurane (aqueous concentrations 140 and 100 μmol/L, respectively) to the solution, followed by addition of IC5, IC25, or IC50 rocuronium. The amount of inhibition was calculated to quantify their synergistic effect. The inhibitory effect of rocuronium was enhanced by sevoflurane or isoflurane in a concentration-dependent manner. Sevoflurane or isoflurane (0.5 IC5) with rocuronium at IC5, IC25, and IC50 synergistically inhibited the current amplitude of adult-type muscle ε-nAChR. When the IC5 of rocuronium was used, isoflurane had a stronger synergistic effect than sevoflurane (p < 0.05). When rocuronium was applied at higher concentrations (IC25 and IC50), sevoflurane had an effect similar to that of isoflurane. For both inhaled anesthetics, the synergistic effect was more intense for rocuronium at IC5 than for rocuronium at IC25 or IC50. Residual-concentration sevoflurane or isoflurane has a strong synergistic effect with rocuronium at clinically relevant residual concentrations. A lower rocuronium concentration resulted in a stronger synergistic effect.

Effects of concentrated leachate injection modes on stabilization of landfilled waste.

PubMed

He, Ruo; Wei, Xiao-Meng; Chen, Min; Su, Yao; Tian, Bao-Hu

2016-02-01

Injection of concentrated leachate to landfills is a simple and cost-effective technology for concentrated leachate treatment. In this study, the effects of injection mode of concentrated leachate and its hydraulic loading rate on the stabilization of landfilled waste were investigated. Compared with the injection of concentrated leachate, the joint injection of leachate and concentrated leachate (1:1, v/v) was more beneficial to the degradation of landfilled waste and mitigated the discharge amount of pollutants at the hydraulic loading rate of 5.9 L m(-2) day(-1). As the hydraulic loading rate of the joint injection of leachate and concentrated leachate was increased from 5.9 to 17.6 L m(-2) day(-1), the organic matter, biologically degradable matter, and total nitrogen of landfilled waste were degraded more rapidly, with the degradation constant of the first-order kinetics of 0.005, 0.004, and 0.003, respectively. Additionally, NO2(-)-N and NO3(-)-N in the concentrated leachate could be well removed in the landfill bioreactors. These results showed that a joint injection of concentrated leachate and raw leachate might be a good way to relieve the inhibitory effect of high concentrations of toxic pollutants in the concentrated leachate and accelerate the stabilization of landfilled waste.

Assessment of combined antiandrogenic effects of binary parabens mixtures in a yeast-based reporter assay.

PubMed

Ma, Dehua; Chen, Lujun; Zhu, Xiaobiao; Li, Feifei; Liu, Cong; Liu, Rui

2014-05-01

To date, toxicological studies of endocrine disrupting chemicals (EDCs) have typically focused on single chemical exposures and associated effects. However, exposure to EDCs mixtures in the environment is common. Antiandrogens represent a group of EDCs, which draw increasing attention due to their resultant demasculinization and sexual disruption of aquatic organisms. Although there are a number of in vivo and in vitro studies investigating the combined effects of antiandrogen mixtures, these studies are mainly on selected model compounds such as flutamide, procymidone, and vinclozolin. The aim of the present study is to investigate the combined antiandrogenic effects of parabens, which are widely used antiandrogens in industrial and domestic commodities. A yeast-based human androgen receptor (hAR) assay (YAS) was applied to assess the antiandrogenic activities of n-propylparaben (nPrP), iso-propylparaben (iPrP), methylparaben (MeP), and 4-n-pentylphenol (PeP), as well as the binary mixtures of nPrP with each of the other three antiandrogens. All of the four compounds could exhibit antiandrogenic activity via the hAR. A linear interaction model was applied to quantitatively analyze the interaction between nPrP and each of the other three antiandrogens. The isoboles method was modified to show the variation of combined effects as the concentrations of mixed antiandrogens were changed. Graphs were constructed to show isoeffective curves of three binary mixtures based on the fitted linear interaction model and to evaluate the interaction of the mixed antiandrogens (synergism or antagonism). The combined effect of equimolar combinations of the three mixtures was also considered with the nonlinear isoboles method. The main effect parameters and interaction effect parameters in the linear interaction models of the three mixtures were different from zero. The results showed that any two antiandrogens in their binary mixtures tended to exert equal antiandrogenic activity in the linear concentration ranges. The antiandrogenicity of the binary mixture and the concentration of nPrP were fitted to a sigmoidal model if the concentrations of the other antiandrogens (iPrP, MeP, and PeP) in the mixture were lower than the AR saturation concentrations. Some concave isoboles above the additivity line appeared in all the three mixtures. There were some synergistic effects of the binary mixture of nPrP and MeP at low concentrations in the linear concentration ranges. Interesting, when the antiandrogens concentrations approached the saturation, the interaction between chemicals were antagonistic for all the three mixtures tested. When the toxicity of the three mixtures was assessed using nonlinear isoboles, only antagonism was observed for equimolar combinations of nPrP and iPrP as the concentrations were increased from the no-observed-effect-concentration (NOEC) to effective concentration of 80%. In addition, the interactions were changed from synergistic to antagonistic as effective concentrations were increased in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP. The combined effects of three binary antiandrogens mixtures in the linear ranges were successfully evaluated by curve fitting and isoboles. The combined effects of specific binary mixtures varied depending on the concentrations of the chemicals in the mixtures. At low concentrations in the linear concentration ranges, there was synergistic interaction existing in the binary mixture of nPrP and MeP. The interaction tended to be antagonistic as the antiandrogens approached saturation concentrations in mixtures of nPrP with each of the other three antiandrogens. The synergistic interaction was also found in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP, at low concentrations with another method of nonlinear isoboles. The mixture activities of binary antiandrogens had a tendency towards antagonism at high concentrations and synergism at low concentrations.

Extremely high myoglobin plasma concentrations producing hook effect in a critically ill patient.

PubMed

Kurt-Mangold, Michelle; Drees, Denny; Krasowski, Matthew D

2012-12-24

A 21-year old female suffered a cardiac arrest after a one week history of viral illness later shown to be caused by influenza B. The patient required extended cardiopulmonary resuscitation and had further complications including compartment syndrome. Plasma myoglobin concentration was measured using the Roche Diagnostics electrochemiluminescent myoglobin assay. The myoglobin concentration was 205,590 μg/l in an undiluted specimen, consistent with severe rhabdomyolysis. Subsequent myoglobin concentrations measured two days later showed dramatic decreases to approximately 1000 μg/l, raising suspicion of a hook effect. Dilution and re-analysis of the specimens revealed that the actual myoglobin concentrations were >395,000 μg/l, with one specimen possessing an estimated myoglobin concentration of >600,000 μg/l. Interestingly, three specimens from this patient did not show evidence of hook effect, with undiluted specimens producing myoglobin concentrations as high as 284,000 μg/l. Retrospective analysis of myoglobin results over an 8-year period did not reveal other cases with suspicion of hook effect. The case patient had the highest myoglobin concentrations out of 7301 specimens. This case illustrates that while the Roche myoglobin assay has a very wide dynamic range, hook effect can occur with extremely high concentrations of plasma myoglobin. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of biochar addition on toxic element concentrations in plants: A meta-analysis.

PubMed

Peng, Xin; Deng, Yinger; Peng, Yan; Yue, Kai

2018-03-01

Consuming food contaminated by toxic elements (TEs) could pose a substantial risk to human health. Recently, biochar has been extensively studied as an effective soil ameliorant in situ because of its ability to suppress the phytoavailability of TEs. However, despite the research interest, the effects of biochar applications to soil on different TE concentrations in different plant parts remain unclear. Here, we synthesize 1813 individual observations data collected from 97 articles to evaluate the effects of biochar addition on TE concentrations in plant parts. We found that (1) the experiment type, biochar feedstock and pyrolysis temperature all significantly decreased the TE concentration in plant parts; (2) the responses of Cd and Pb concentrations in edible and indirectly edible plant parts were significantly more sensitive to the effect of biochar than the Zn, Ni, Mn, Cr, Co and Cu concentrations; and (3) the biochar dosage and surface area, significantly influenced certain TE concentrations in plant tissues as determined via correlation analysis. Moreover, the only exception in this study was found for metalloid element (i.e., As) concentrations in plants, which were not significantly influenced by biochar addition. Overall, the effects of biochar on TE concentrations in plant tissues were negative, at least on average, and the central trends suggest that biochar has a considerable ability to mitigate the transfer of TEs to food, thereby reducing the associated health risks. Our results provide an initial quantitative determination of the effects of biochar addition on multifarious TEs in different plant parts as well as an assessment of the ability of biochar to reduce TE concentrations in plants. Copyright © 2017 Elsevier B.V. All rights reserved.

EFFECTS OF COMMONLY USED COOKING PRACTICES ON TOTAL MERCURY CONCENTRATION IN FISH AND THEIR IMPACT ON EXPOSURE ASSESSMENTS

EPA Science Inventory

The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmenta...

Posaconazole in Human Serum: a Greater Pharmacodynamic Effect than Predicted by the Non-Protein-Bound Serum Concentration ▿

PubMed Central

Lignell, Anders; Löwdin, Elisabeth; Cars, Otto; Chryssanthou, Erja; Sjölin, Jan

2011-01-01

It is generally accepted that only the unbound fraction of a drug is pharmacologically active. Posaconazole is an antifungal agent with a protein binding of 98 to 99%. Taking into account the degree of protein binding, plasma levels in patients, and MIC levels of susceptible strains, it can be assumed that the free concentration of posaconazole sometimes will be too low to exert the expected antifungal effect. The aim was therefore to test the activity of posaconazole in serum in comparison with that of the calculated unbound concentrations in protein-free media. Significant differences (P < 0.05) from the serum control were found at serum concentrations of posaconazole of 1.0 and 0.10 mg/liter, with calculated free concentrations corresponding to 1× MIC and 0.1× MIC, respectively, against one Candida lusitaniae strain selected for proof of principle. In RPMI 1640, the corresponding calculated unbound concentration of 0.015 mg/liter resulted in a significant effect, whereas that of 0.0015 mg/liter did not. Also, against seven additional Candida strains tested, there was an effect of the low posaconazole concentration in serum, in contrast to the results in RPMI 1640. Fluconazole, a low-grade-protein-bound antifungal, was used for comparison at corresponding concentrations in serum and RPMI 1640. No effect was observed at the serum concentration, resulting in a calculated unbound concentration of 0.1× MIC. In summary, there was a substantially greater pharmacodynamic effect of posaconazole in human serum than could be predicted by the non-protein-bound serum concentration. A flux from serum protein-bound to fungal lanosterol 14α-demethylase-bound posaconazole is suggested. PMID:21502622

Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli.

PubMed

Zhang, Haoshu; Dudley, Edward G; Davidson, P Michael; Harte, Federico

2017-04-15

Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. Copyright © 2017 American Society for Microbiology.

Effect of molecular weight and concentration of hyaluronan on cell proliferation and osteogenic differentiation in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Ningbo, E-mail: curl-zhao@163.com; Wang, Xin, E-mail: 394041230@qq.com; Qin, Lei, E-mail: qinlei30@126.com

Hyaluronan (HA), the simplest glycosaminoglycan and a major component of the extracellular matrix, exists in various tissues. It is involved in some critical biological procedures, including cellular signaling, cell adhesion and proliferation, and cell differentiation. The effect of molecular weight (MW) and concentration of HA on cell proliferation and differentiation was controversial. In this study, we investigated the effect of MW and concentration of HA on the proliferation and osteogenic differentiation of rabbit bone marrow-derived stem cells in vitro. Results showed that high MW HA decreased the cell adhesion rate in a concentration-dependant manner. The cell adhesion rate was decreased bymore » increasing MW of HA. Cell proliferation was significantly enhanced by low MW HA (P < 0.05). The factorial analysis indicated that MW and concentration had an interactive effect on the cell adhesion rate and cell proliferation (P < 0.05). High MW HA increased the mRNA expressions of ALP, RUNX-2 and OCN. The higher the MW was, the higher the mRNA expressions were. The factorial analysis indicated that MW and concentration had an interactive effect on ALP mRNA expression (P < 0.05). HA of higher MW and higher concentration promoted bone formation. These findings provide some useful information in understanding the mechanism underlying the effect of MW and concentration of HA on cell proliferation and differentiation. - Highlights: • Effect of hyaluronan on cell proliferation and differentiation is evaluated in vitro. • Hyaluronan of low molecular weight increases cell proliferation. • Hyaluronan of high molecular weight promotes cell osteogenic differentiation. • Molecular weight and concentration of hyaluronan show interactive effect.« less

Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli

PubMed Central

Zhang, Haoshu; Dudley, Edward G.; Davidson, P. Michael

2017-01-01

ABSTRACT Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. PMID:28213539

Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington--Part II: controlled exposure studies.

PubMed

Frew, John A; Grue, Christian E

2015-11-01

The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L(-1) , and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L(-1) . No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. © 2015 SETAC.

The Effects of Donepezil, an Acetylcholinesterase Inhibitor, on Impaired Learning and Memory in Rodents.

PubMed

Shin, Chang Yell; Kim, Hae-Sun; Cha, Kwang-Ho; Won, Dong Han; Lee, Ji-Yun; Jang, Sun Woo; Sohn, Uy Dong

2018-05-01

A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately 1.2 ± 0.4 h and 1.4 ± 0.5 h, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of 31.5 ± 5.7% was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at 46.5 ± 3.5 ng/g in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, 46.5 ± 3.5 ng/g donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

NREL, Abengoa Making Concentrating Solar Power System Manufacturing More

Science.gov Websites

Cost Effective | Energy Systems Integration Facility | NREL Abengoa NREL, Abengoa Making Concentrating Solar Power System Manufacturing More Cost Effective Abengoa is working with NREL researchers to develop a new and more cost-effective manufacturing process for critical components of concentrating solar

[Effect of propofol at different effect-site concentrations on approximate entropy of transient evoked otoacoustic emission signals in adults].

PubMed

Zhang, Xin-jian; Gu, Miao-ning; Xiao, Jin-fang

2009-01-01

To study the effect of propofol at different effect-site concentrations on approximate entropy (ApEn) of transient evoked otoacoustic emission (TEOAE) signals in adults and investigate the possibility of using ApEn for monitoring anesthesia depth. Fifteen ASA class I or II patients (aged 18-49 years with normal hearing) undergoing elective surgery under general anesthesia were enrolled in this study. Anesthesia was maintained with target-controlled infusion of propofol. With the effect-site concentrations of 1, 2, 3 and 4 microg/ml, TEOAE signals were monitored and recorded before and after anesthesia. ApEn of TEOAE in 4 frequency ranges (0-2, 1-3, 2.5-4.5, and 4-6 kHz) were calculated using MATLAB software. The ApEn of TEOAE in different frequency ranges showed no significant differences at the same effect-site concentration of propofol, or at different effect-site concentrations in the same frequency range (P>0.05). Anesthesia with propofol at different effect-site concentrations does not obviously affect ApEn of TEOAE signals in adults, and ApEn can not be used as the indicator for evaluating the depth of anesthesia.

Ovicidal activity of different concentrations of Pochonia chlamydosporia chlamydospores on Taenia taeniaeformis eggs.

PubMed

Braga, F R; Silva, A R; Carvalho, R O; Araújo, J V; Pinto, P S A

2011-03-01

Three concentrations of chlamydospores of the nematophagous fungus Pochonia chlamydosporia (1000, 10,000 and 20,000 per Petri dish) were evaluated in vitro on Taenia taeniaeformis eggs. Chlamydospores at each concentration were cultured in two different media: 2% water-agar (2%WA) and 2% corn-meal-agar (2%CMA). Taenia taeniaeformis eggs were plated in each chlamydospore concentration in 2%WA and 2%CMA (treated groups) and without fungus (control group). Eggs were removed from each Petri dish at intervals of 7, 14 and 21 days and classified according to ovicidal activity (type 1, type 2 and type 3 effects). Plates containing 2%CMA showed the highest percentages for type 3 effect (81.3%) on the 21st day of observation. A difference (P < 0.01) between the media 2%WA and 2%CMA for type 1 effect was observed only at a concentration of 1000 chlamydospores on the 7th day. There were differences (P < 0.01) between 2%WA and 2%CMA on the 14th and 21st days, at the concentration of 20,000 chlamydospores, for type 1 and type 3 effects. Regression curves for type 3 effect in 2%WA and 2%CMA at the tested concentrations showed higher ovicidal activity with increasing chlamydospore concentrations. Results indicate that, at concentrations of 1000, 10,000 and 20,000 per Petri dish, chlamydospores of P. chlamydosporia effectively destroyed T. taeniaeformis eggs and can be considered a potential biological control agent for this cestode.

Antifungal activity of Piper aduncum and Peperomia pellucida leaf ethanol extract against Candida albicans

NASA Astrophysics Data System (ADS)

Hastuti, Utami Sri; Ummah, Yunita Putri Irsadul; Khasanah, Henny Nurul

2017-05-01

This research was done to 1) examine the effect of Piper aduncum leaf ethanol extract at certain concentrations against Candida albicans colony growth inhibition in vitro; 2) examine the effect of Peperomia pellucida leaf ethanol extract at certain concentrations toward Candida albicans colony growth inhibition in vitro; and 3) determine the most effective concentration of P. aduncum and P. pellucida leaves ethanol extract against C. albicans colony growth inhibition in vitro. These plant extracts were prepared by the maceration technique using 95% ethanol, and then sterile filtered and evaporated to obtain the filtrate. The filtrate was diluted with sterile distilled water at certain concentrations, i.e.: 0%, 10%, 20%, 30%, 405, 50%, 60%, 70%, 80%, and 90%. The antifungal effect of each leaf extract concentration was examined by the agar diffusion method on Sabouraud Dextrose Agar medium. The research results are: 1) the P.aduncum leaf ethanol extract at some concentrations has an effect against C. albicans colony growth inhibition in vitro; 2) the P.pellucida leaf ethanol extract at some concentrations has an effect against C. albicans colony growth inhibition in vitro; 3) the P. aduncum leaf ethanol extract at 80% is the most effective for C. albicans colony growth inhibition in vitro; and 4) the P. pellucida leaf ethanol extract at 70% is the most effective for C. albicans colony growth inhibition in vitro.

Effect of ascorbic acid on the stability of beta-carotene and capsanthin in paprika (Capsicum annuum) powder.

PubMed

Morais, H; Rodrigues, P; Ramos, C; Forgács, E; Cserháti, T; Oliveira, J

2002-10-01

The effect of ascorbic acid, light, and storage on the stability of the pigments beta-carotene and capsanthin in red pepper (Capsicum annuum) powder has been elucidated by determining the amount of pigment in samples treated by various concentrations of ascorbic acid. Determination of pigment concentration has been performed after different storage times using high-performance liquid chromatography. The dependence of the concentration of pigments on the concentration of ascorbic acid, presence of light and the storage time has been assessed by stepwise regression analysis. The concentration of pigments decreased at longer storage time and increased at higher concentration of ascorbic acid, beta-carotene being more sensitive towards storage time and concentration of ascorbic acid than capsanthin. Interaction between the effects of light and storage time, and light and concentration of ascorbic acid has been established.

Effect of Monascus purpureus inoculum concentration on pigment production in jackfruit seed flour substrate

NASA Astrophysics Data System (ADS)

Hamdiyati, Yanti; Kusnadi, Yuliani, Lia Amelia

2016-02-01

The used of synthetic dyes have various negative effects on human health. Roomates pigment produced by Monascus purpureus mold can be used as an alternative natural food coloring. The research on the effect of inoculum concentration's M. purpureus to pigment production on the jackfruit seed flour has been done. The objective of research to is to investigate the effect of inoculum concentration's M. purpureus to the production of red, yellow and orange pigment on the jackfruit seed flour. The concentrations used were 0%, 5%, 10%, and 15% (v/w). The result of the data analysed using One-Way ANOVA showed that the inoculum concentration affected the production of red pigment M. purpureus, as well as the data analysis using the Kruskal-Wallis showed that inoculum concentration has influence on the production of yellow and orange pigments. Inoculum concentration of 15% is the optimum concentration for the production of red, yellow and orange pigments with 0:10, 0:50 and 0:20 absorbance units per gram of sample respectively. Based on the results of the research, it can be concluded that inoculum concentration of M. purpureus influenced the production of red, yellow and orange pigments.

The Effects of Acetate Buffer Concentration on Lysozyme Solubility

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Pusey, Marc L.

1996-01-01

The micro-solubility column technique was employed to systematically investigate the effects of buffer concentration on tetragonal lysozyme solubility. While keeping the NaCl concentrations constant at 2%, 3%, 4%, 5% and 7%, and the pH at 4.0, we have studied the solubility of tetragonal lysozyme over an acetate buffer concentration range of 0.01M to 0.5M as a function of temperature. The lysozyme solubility decreased with increasing acetate concentration from 0.01M to 0.1M. This decrease may simply be due to the net increase in solvent ionic strength. Increasing the acetate concentration beyond 0.1M resulted in an increase in the lysozyme solubility, which reached a peak at - 0.3M acetate concentration. This increase was believed to be due to the increased binding of acetate to the anionic binding sites of lysozyme, preventing their occupation by chloride. In keeping with the previously observed reversal of the Hoffmeister series for effectiveness of anions in crystallizing lysozyme, acetate would be a less effective precipitant than chloride. Further increasing the acetate concentration beyond 0.3M resulted in a subsequent gradual decrease in the lysozyme solubility at all NaCl concentrations.

Melatonin induces opposite effects on order and dynamics of anionic DPPG model membranes

NASA Astrophysics Data System (ADS)

Sahin, Ipek; Severcan, Feride; Kazancı, Nadide

2007-05-01

The temperature and concentration induced effects of melatonin on anionic dipalmitoyl phosphatidylglycerol (DPPG) multilamellar liposomes (MLVs) were investigated by using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The results show that melatonin does not perturb the phase transition profile, while a decrease in the main transition temperature ( Tm) is noticed at high melatonin concentrations (15, 24 and 30 mol %). Low concentrations of melatonin (3, 6 and 9 mol %) decrease the frequency of the CH 2 stretching mode, implying an ordering effect, whilst high concentrations of melatonin disorders system both in the gel and liquid crystalline phases. Furthermore, at low and high concentrations, melatonin also causes opposite effect on membrane dynamics. The bandwidth of the CH 2 stretching modes decreases at low concentrations, implying a decrease in the dynamics, while increasing it at high concentrations. Furthermore, it causes significant decrease in the frequency of the C dbnd O stretching and PO2- antisymmetric double bond stretching bands of DPPG for all concentrations both in the gel and liquid crystalline phases, which indicates strong hydrogen bonding around these functional groups.

Effects of cadmium ingestion and food restriction on energy metabolism and tissue metal concentrations in mallard ducks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Giulio, R.T.; Scanlon, P.F.

1985-08-01

The single and combined effects of cadmium ingestion and food restriction were examined in a 42-day experiment with male, juvenile mallard ducks. A 2 x 3 factorial design was employed consisting of two levels of food supply (ad libitum and 55% of ad libitum intake) and three levels of cadmium in the food (0, 5 or 50 ..mu..g Cd/g food). Cadmium ingestion alone had no effect on body or tissue weights, liver glycogen, plasma concentrations of glucose, urea, uric acid, nonesterified fatty acids (NEFA), triiodothyronine (T/sub 3/), thyroxine (T/sub 4/), or plasma or adrenal concentrations of corticosterone. The food restrictionmore » resulted in reduced body weights and reduced weights of livers, kidneys, and testes, increased adrenal weights, reduced liver glycogen, increased plasma NEFA concentrations, reduced plasma T/sub 3/ and T/sub 4/ concentrations, and increased adrenal corticosterone concentrations. In combination with the food restrictions, cadmium ingestion further reduced plasma T/sub 3/ concentrations and a similar trend was noted for T/sub 4/. Additionally, the highest plasma NEFA concentrations and highest plasma and adrenal concentrations of corticosterone were observed in food-restricted ducks receiving the highest level of dietary cadmium. These results suggest that ability of cadmium ingestion to enhanced food restriction-induced alterations in energy metabolism at levels of dietary cadmium that are by themselves without apparent effect. Also, cadmium ingestion resulted in increased kidney concentrations of copper and zinc: this effect on kidney zinc concentrations was increased in food-restricted ducks.« less

Development of a strontium chronic effects benchmark for aquatic life in freshwater.

PubMed

McPherson, Cathy A; Lawrence, Gary S; Elphick, James R; Chapman, Peter M

2014-11-01

There are no national water-quality guidelines for strontium for the protection of freshwater aquatic life in North America or elsewhere. Available data on the acute and chronic toxicity of strontium to freshwater aquatic life were compiled and reviewed. Acute toxicity was reported to occur at concentrations ranging from 75 mg/L to 15 000 mg/L. The majority of chronic effects occurred at concentrations above 11 mg/L; however, calculation of a representative benchmark was confounded by results from 4 studies indicating that chronic effects occurred at lower concentrations than all other studies, in 2 cases below background concentrations reported for US and European streams. Two of these studies, including 1 reporting effects below background concentrations, were repeated and found not to be reproducible; chronic effects occurred at considerably higher strontium concentrations than in the original studies. Studies with narrow-mouthed toad and goldfish were not repeated; both studies reported chronic effects below background concentrations, and both studies had been conducted by the authors of 1 of the 2 studies that were repeated and shown to be nonreproducible. Studies by these authors (3 of the 4 confounding studies), conducted over 30 yr ago, lacked detail in reporting of methods and results. It is thus likely that repeating the toad and goldfish studies would also have resulted in a higher strontium effects concentration. A strontium chronic effects benchmark of 10.7 mg/L that incorporates the results of additional testing summarized in the present study is proposed for freshwater environments. © 2014 SETAC.

Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

PubMed

Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

2003-04-01

A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed. Copyright 2002 Elsevier Science Ltd.

Concentration rather than dose defines the local brain toxicity of agents that are effectively distributed by convection-enhanced delivery.

PubMed

Zhang, Rong; Saito, Ryuta; Mano, Yui; Kanamori, Masayuki; Sonoda, Yukihiko; Kumabe, Toshihiro; Tominaga, Teiji

2014-01-30

Convection-enhanced delivery (CED) has been developed as a potentially effective drug-delivery strategy into the central nervous system. In contrast to systemic intravenous administration, local delivery achieves high concentration and prolonged retention in the local tissue, with increased chance of local toxicity, especially with toxic agents such as chemotherapeutic agents. Therefore, the factors that affect local toxicity should be extensively studied. With the assumption that concentration-oriented evaluation of toxicity is important for local CED, we evaluated the appearance of local toxicity among different agents after delivery with CED and studied if it is dose dependent or concentration dependent. Local toxicity profile of chemotherapeutic agents delivered via CED indicates BCNU was dose-dependent, whereas that of ACNU was concentration-dependent. On the other hand, local toxicity for doxorubicin, which is not distributed effectively by CED, was dose-dependent. Local toxicity for PLD, which is extensively distributed by CED, was concentration-dependent. Traditional evaluation of drug induced toxicity was dose-oriented. This is true for systemic intravascular delivery. However, with local CED, toxicity of several drugs exacerbated in concentration-dependent manner. From our study, local toxicity of drugs that are likely to distribute effectively tended to be concentration-dependent. Concentration rather than dose may be more important for the toxicity of agents that are effectively distributed by CED. Concentration-oriented evaluation of toxicity is more important for CED. Copyright © 2013 Elsevier B.V. All rights reserved.

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

NASA Astrophysics Data System (ADS)

Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

2015-07-01

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P<0.01), the quadratic effects of temperature were significant ( P<0.05), the linear effects of copper ion concentration were not significant ( P>0.05), and the quadratic effects of copper ion concentration were significant ( P<0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant ( P>0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

Antibacterial Effects of Different Concentrations of Althaea officinalis Root Extract versus 0.2% Chlorhexidine and Penicillin on Streptococcus mutans and Lactobacillus (In vitro).

PubMed

Haghgoo, Roza; Mehran, Majid; Afshari, Elahe; Zadeh, Hamide Farajian; Ahmadvand, Motahare

2017-01-01

The aims of the present study were to determine and compare the effects of different concentrations of Althaea officinalis extract, 0.2% chlorhexidine (CHX), and penicillin on Streptococcus mutans and Lactobacillus acidophilus in vitro . The laboratory study was done, for a period of 8 weeks. Minimum inhibitory concentration (MIC) in the test tube, minimum bactericidal concentration (MBC) in a plate culture medium, and growth inhibition zone diameter methods were used to compare the antibacterial effects of 0.2% CHX, penicillin, and different concentrations of A. officinalis root extract. The data were analyzed by SPSS version 24 using ANOVA and t -test analysis. The results showed A. officinalis root extract had antibacterial effect, but significant differences were in MIC and MBC against L. acidophilus and S. mutans with penicillin and 0.2% CHX mouthwash. In addition, the mean growth inhibition zones of all the concentrations of the plant extract were less than that of the positive control group ( P = 0.001). However, the difference in the maximum growth inhibition zone from that with the negative control group was significant. In addition, the antibacterial effect of the extract increased with an increase in its concentration. The extract exerted a greater antibacterial effect on S. mutans than on L. acidophilus . The plant polyphenols content is 3.7% which is equivalent to 29.93 g/ml. The root extract of A. officinalis exhibited antibacterial effects on S. mutans and L. acidophilus , but this effect was less than those of CHX mouthwash and penicillin. The antibacterial effect increased with an increase in the concentration of the extract.

Effect-site concentration of remifentanil during patient-controlled analgesia in labour.

PubMed

Jost, A; Blagus, R; Ban, B; Kamenik, M

2015-08-01

Intravenous remifentanil has been described for patient-controlled analgesia in labour. Recently, the application of target-controlled infusion pumps with Minto's pharmacokinetic/pharmacodynamic model has been reported. Hypothetical effect-site remifentanil concentration during patient-controlled analgesia for labour has yet to be examined. The aim of this concept study was to explore characteristics of this parameter. We performed a historical cohort study based on our previous randomised cross-over clinical trial and analysed hypothetical effect-site remifentanil concentration. Values at spontaneous vaginal delivery and Apgar scores were tested for correlation. The association between pain score and the corresponding effect-site remifentanil concentration before and after bolus administration, and their relative difference, was examined with a linear mixed-effects model, adjusted for other variables. A series of 23 parturients with uncomplicated singleton pregnancies were included. On average, effect-site remifentanil concentration was highest during the third quarter throughout our recordings (5.5ng/mL; maximum 15.8ng/mL). The mean (median) {IQR} [range] at spontaneous vaginal delivery (n=14) was 2.52 (1.32) {0.95-4.28} [0.65-6.88] ng/mL, all Apgar scores were >7, and no correlation was confirmed. A negative association between effect-site remifentanil concentration before bolus administration and pain score (scale 0-100) was observed (-3.9, 95% CI -5.16 to -2.61, P <0.01). The residual value of hypothetical effect-site remifentanil concentration before uterine contraction, at the beginning of bolus administration, predicted lower pain scores. Monitoring effect-site remifentanil concentration may be potentially useful when remifentanil is administered for labour analgesia. However, our results need to be confirmed with a pharmacokinetic model optimized for pregnant patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Monitoring total endotoxin and (1 --> 3)-beta-D-glucan at the air exhaust of concentrated animal feeding operations.

PubMed

Yang, Xufei; Wang, Xinlei; Zhang, Yuanhui; Lee, Jongmin; Su, Jingwei; Gates, Richard S

2013-10-01

Mitigation of bioaerosol emissions from concentrated animal feeding operations (CAFOs) demands knowledge of bioaerosol concentrations feeding into an end-of-pipe air treatment process. The aim of this preliminary study was to measure total endotoxin and (1 --> 3)-beta-glucan concentrations at the air exhaust of 18 commercial CAFOs and to examine their variability with animal operation type (swine farrowing, swine gestation, swine weaning, swine finishing, manure belt laying hen, and tom turkey) and season (cold, mild, and hot). The measured airborne concentrations of total endotoxin ranged from 98 to 23,157 endotoxin units (EU)/m3, and the airborne concentrations of total (1 --> 3)-beta-D-glucan ranged from 2.4 to 537.9 ng/m3. Animal operation type in this study had a significant effect on airborne concentrations of total endotoxin and (1 --> 3)-beta-D-glucan but no significant effect on their concentrations in total suspended particulate (TSP). Both endotoxin and (1 --> 3)-beta-D-glucan attained their highest airborne concentrations in visited tom turkey buildings. Comparatively, season had no significant effect on airborne concentrations of total endotoxin or (1 --> 3)-beta-D-glucan. Endotoxin and (1 --> 3)-beta-glucan concentrations in TSP dust appeared to increase as the weather became warmer, and this seasonal effect was significant in swine buildings. Elevated indoor temperatures in the hot season were considered to facilitate the growth and propagation of bacteria and fungi, thus leading to higher biocomponent concentrations in TSP.

A comparison of the effects of four therapy procedures on concentration and responsiveness in people with profound learning disabilities.

PubMed

Lindsay, W R; Pitcaithly, D; Geelen, N; Buntin, L; Broxholme, S; Ashby, M

1997-06-01

This paper is an investigation into the efficacy of four therapeutic treatment procedures increasingly used with people with profound learning disabilities: snoezelen, hand massage/aromatherapy, relaxation, and active therapy (a bouncy castle). In particular, the effects of these procedures on concentration and responsiveness were examined. Eight subjects with profound learning disabilities took part in the study and each subject received each of the treatments. To assess the effects of the treatments, simple concentration tasks were administered and the subjects' responsiveness to each treatment was rated by independent observers. The results suggest that both snoezelen and relaxation had a positive effect on concentration and seemed to be the most enjoyable therapies for clients, whereas hand massage/aromatherapy and active therapy had no or even negative effects on concentration and appeared less enjoyable.

Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria.

PubMed

Ricart, Marta; Barceló, Damià; Geiszinger, Anita; Guasch, Helena; de Alda, Miren López; Romaní, Anna M; Vidal, Gemma; Villagrasa, Marta; Sabater, Sergi

2009-09-01

A system of recirculating channels was used in this study to examine the long-term effects (29d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 microg L(-1)) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components.

Can natural variation in grain P concentrations be exploited in rice breeding to lower fertilizer requirements?

PubMed

Wang, Fanmiao; King, James Douglas Morrison; Rose, Terry; Kretzschmar, Tobias; Wissuwa, Matthias

2017-01-01

Agricultural usage of phosphorus (P) is largely driven by the amount of P removed from fields in harvested plant matter as offtake needs to be balanced by P fertilizer application. Reducing P concentration in grains is a way to decrease P offtake and reduce P fertilizer requirements or soil P mining where insufficient P is applied. Our objective was to assesses the genotypic variation for grain P concentration present within the rice gene pool and resolve to what extent it is affected by environment (P supply) or associated with genetic factors. About 2-fold variation in grain P concentrations were detected in two rice diversity panels, however, environmental effects were stronger than genotype effects. Genome wide association studies identified several putative loci associated with grain P concentrations. In most cases this was caused by minor haplotype associations with high grain P concentrations while associations with reduced P concentrations were identified on chromosomes 1, 6, 8, 11 and 12. Only the latter type of locus is of interest in breeding for reduced P concentrations and the most promising locus was at 20.7 Mb on chromosome 8, where a rare haplotype that was absent from all modern varieties studied reduced grain P concentration by 9.3%. This and all other loci were not consistently detected across environments or association panels, confirming that genetic effects were small compared to effects of environment. We conclude that the genetic effects detected were not sufficiently large or consistent to be of utility in plant breeding. Instead breeding efforts may have to rely on small to medium effect mutants already identified and attempt to achieve a more pronounced reduction in grain P concentration through the introgression of these mutants into a single genetic background.

Can natural variation in grain P concentrations be exploited in rice breeding to lower fertilizer requirements?

PubMed Central

Wang, Fanmiao; King, James Douglas Morrison; Rose, Terry; Kretzschmar, Tobias

2017-01-01

Agricultural usage of phosphorus (P) is largely driven by the amount of P removed from fields in harvested plant matter as offtake needs to be balanced by P fertilizer application. Reducing P concentration in grains is a way to decrease P offtake and reduce P fertilizer requirements or soil P mining where insufficient P is applied. Our objective was to assesses the genotypic variation for grain P concentration present within the rice gene pool and resolve to what extent it is affected by environment (P supply) or associated with genetic factors. About 2-fold variation in grain P concentrations were detected in two rice diversity panels, however, environmental effects were stronger than genotype effects. Genome wide association studies identified several putative loci associated with grain P concentrations. In most cases this was caused by minor haplotype associations with high grain P concentrations while associations with reduced P concentrations were identified on chromosomes 1, 6, 8, 11 and 12. Only the latter type of locus is of interest in breeding for reduced P concentrations and the most promising locus was at 20.7 Mb on chromosome 8, where a rare haplotype that was absent from all modern varieties studied reduced grain P concentration by 9.3%. This and all other loci were not consistently detected across environments or association panels, confirming that genetic effects were small compared to effects of environment. We conclude that the genetic effects detected were not sufficiently large or consistent to be of utility in plant breeding. Instead breeding efforts may have to rely on small to medium effect mutants already identified and attempt to achieve a more pronounced reduction in grain P concentration through the introgression of these mutants into a single genetic background. PMID:28651022

Toxic effects of lead on biochemical and histological alterations in green mussel (Perna viridis) induced by environmentally relevant concentrations.

PubMed

Hariharan, G; Purvaja, R; Ramesh, R

2014-01-01

Acute and chronic toxicity tests were conducted on green mussel (Perna viridis) to determine the adverse effects of lead (Pb). Exposure of organisms to acute toxicity test for 96 h and lethal concentration (LC(50)) was the endpoint of the test. Acute toxicity for 96-h LC(50) and 95% confidence intervals of P. viridis was 2.62 ± 0.12 (2.62-3.24) mg/L Pb. Chronic toxicity tests revealed that survival of exposed organisms decreased with elevated exposure concentrations. No-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) were calculated based on survival of test organisms. Results of this study demonstrated an increase in toxicity in test organisms with rise in exposure time and concentration. In this study, histology and biochemical enzymes, namely, catalase, reduced glutathione, glutathione S-transferase, and lipid peroxides, were correlated with chronic value and survival endpoints of P. viridis after chronic exposure to Pb. Biochemical and histological responses to different concentrations of Pb were assessed and significant differences were observed between control and increasing exposure concentrations. Biomarker studies in internal organs confirmed that the observed changes are due to adverse effects of Pb. This assessment of toxicity was the first step to determining the seawater quality criteria for marine organisms.

Regulation of net bicarbonate transport in rabbit cortical collecting tubule by peritubular pH, carbon dioxide tension, and bicarbonate concentration.

PubMed Central

Breyer, M D; Kokko, J P; Jacobson, H R

1986-01-01

The effects of changes in peritubular pH, carbon dioxide tension (PCO2), and HCO3- concentration on net HCO3- transport was examined in in vitro perfused cortical collecting tubules (CCTs) from unpretreated New Zealand white rabbits. Lowering peritubular HCO3- concentration and pH by reciprocal replacement of HCO3- with Cl-, significantly stimulated net HCO3- absorption. Lowering peritubular HCO3- concentration and pH, by substitution of HCO3- with gluconate, while keeping Cl- concentration constant, also stimulated net HCO3- absorption. Raising peritubular HCO3- concentration and pH, by reciprocal replacement of Cl- with HCO3-, inhibited net HCO3- absorption (or stimulated net HCO3- secretion). When the tubule was cooled, raising peritubular HCO3- concentration had no effect on net HCO3- transport, suggesting these results are not due to the passive flux of HCO3- down its concentration gradient. The effect of changes in ambient PCO2 on net HCO3- transport were also studied. Increasing the ambient PCO2 from 40 mmHg to either 80 or 120 mmHg, allowing pH to fall, had no effect on net HCO3- transport. Similarly, lowering ambient PCO2 to 14 mmHg had no effect on net HCO3- transport. Simultaneously increasing peritubular HCO3- concentration and PCO2, without accompanying changes in peritubular pH, i.e., isohydric changes, stimulated net HCO3- secretion to the same degree as nonisohydric increases in peritubular HCO3- concentration. Likewise, isohydric lowering of peritubular HCO3- concentration and PCO2 stimulated net HCO3- absorption. We conclude that: acute changes in peritubular HCO3- concentration regulate acidification in the CCT and these effects are mediated by a transcellular process; acute changes in ambient PCO2 within the physiologic range have no effect on HCO3- transport in the in vitro perfused CCT; and acute in vitro regulation of CCT acidification is independent of peritubular pH. PMID:3084564

Effect of crude glycerol-derived inhibitors on ethanol production by Enterobacter aerogenes.

PubMed

Lee, Sang Jun; Kim, Sung Bong; Kang, Seong Woo; Han, Sung Ok; Park, Chulhwan; Kim, Seung Wook

2012-01-01

In this study, ethanol production from pure and crude glycerol using Enterobacter aerogenes ATCC 29007 was evaluated under anaerobic culture conditions. Inhibitory effects of substrate concentrations, pH, and salt concentrations were investigated based on crude glycerol components. Ethanol production was performed with pure glycerol concentrations ranging from 5 to 30 g/L to evaluate the effects of substrate concentration and osmotic pressure. The consumed glycerol was 5-14.33 g/L, and the yield of ethanol was higher than 0.75 mol ethanol/mol glycerol after 24 h of cultivation. To evaluate the inhibitory effects of salts (NaCl and KCl), experiments were performed with 0-20 g/L of each salt. Inhibitory effects of salts were strongest at high salt concentrations. The inhibitory effect of pH was performed in the pH range 4-10, and cell growth and ethanol production were highest at pH 5-6. Also, ethanol production was slightly inhibited at low concentration of crude glycerol comparison with pure glycerol. However, significant inhibitory effects were not observed at 1.5 and 2% crude glycerol which showed higher ethanol production compared to pure glycerol.

Very low concentrations of ethanol suppress excitatory synaptic transmission in rat visual cortex.

PubMed

Luong, Lucas; Bannon, Nicholas M; Redenti, Andrew; Chistiakova, Marina; Volgushev, Maxim

2017-05-01

Ethanol is one of the most commonly used substances in the world. Behavioral effects of alcohol are well described, however, cellular mechanisms of its action are poorly understood. There is an apparent contradiction between measurable behavioral changes produced by low concentrations of ethanol, and lack of evidence of synaptic changes at these concentrations. Furthermore, effects of ethanol on synaptic transmission in the neocortex are poorly understood. Here, we set to determine effects of ethanol on excitatory synaptic transmission in the neocortex. We show that 1-50 mm ethanol suppresses excitatory synaptic transmission to layer 2/3 pyramidal neurons in rat visual cortex in a concentration-dependent manner. To the best of our knowledge, this is the first demonstration of the effects of very low concentrations of ethanol (from 1 mm) on synaptic transmission in the neocortex. We further show that a selective antagonist of A 1 adenosine receptors, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), blocks effects of 1-10 mm ethanol on synaptic transmission. However, the reduction in excitatory postsynaptic potential amplitude by 50 mm ethanol was not affected by DPCPX. We propose that ethanol depresses excitatory synaptic transmission in the neocortex by at least two mechanisms, engaged at different concentrations: low concentrations of ethanol reduce synaptic transmission via A 1 R-dependent mechanism and involve presynaptic changes, while higher concentrations activate additional, adenosine-independent mechanisms with predominantly postsynaptic action. Involvement of adenosine signaling in mediating effects of low concentrations of ethanol may have important implications for understanding alcohol's effects on brain function, and provide a mechanistic explanation to the interaction between alcohol and caffeine. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Impact of plant extracts tested in attention-deficit/hyperactivity disorder treatment on cell survival and energy metabolism in human neuroblastoma SH-SY5Y cells.

PubMed

Schmidt, Andreas Johannes; Krieg, Jürgen-Christian; Hemmeter, Ulrich Michael; Kircher, Tilo; Schulz, Eberhard; Clement, Hans-Willi; Heiser, Philip

2010-10-01

Plant extracts such as Hypericum perforatum and Pycnogenol have been tested as alternatives to the classical ADHD drugs. It has been possible to describe neuroprotective effects of such plant extracts. A reduction of ADHD symptoms could be shown in clinical studies after the application of Pycnogenol, which is a pine bark extract. The impacts of the standardized herbal extracts Hypericum perforatum, Pycnogenol and Enzogenol up to a concentration of 5000 ng/mL on cell survival and energy metabolism in human SH-SY5Y neuroblastoma cells has been investigated in the present examination. Hypericum perforatum significantly decreased the survival of cells after treatment with a concentration of 5000 ng/mL, whereas lower concentrations exerted no significant effects. Pycnogenol( induced a significant increase of cell survival after incubation with a concentration of 32.25 ng/mL and a concentration of 250 ng/mL. Other applied concentrations of Pycnogenol failed to exert significant effects. Treatment with Enzogenol did not lead to significant changes in cell survival.Concerning energy metabolism, the treatment of cells with a concentration of 5000 ng/mL Hypericum perforatum led to a significant increase of ATP levels, whereas treatment with a concentration of 500 ng/mL had no significant effect. Incubation of cells with Pycnogenol and Enzogenol exerted no significant effects.None of the tested substances caused any cytotoxic effect when used in therapeutically relevant concentrations. Copyright © 2010 John Wiley & Sons, Ltd.

Effects of vitamin D supplementation during pregnancy on neonatal vitamin D and calcium concentrations: a systematic review and meta-analysis.

PubMed

Yang, Na; Wang, Linlin; Li, Zhixia; Chen, Sen; Li, Nan; Ye, Rongwei

2015-07-01

We conducted a meta-analysis to review the effects of vitamin D supplementation during pregnancy on neonatal 25-hydroxyvitamin D (25(OH)D) and calcium concentrations. Randomized controlled trials that supplemented subjects with vitamin D2 or D3 during pregnancy and reported cord blood 25(OH)D or calcium concentrations were included. A random-effect model was used to pool the data. Subgroup analyses were performed to explore the sources of heterogeneity. We searched PubMed, Web of Science, and Cochrane Library for relevant publications. Among 1768 publications identified by our search strategy, 13 studies met our inclusion criteria. Cord blood 25(OH)D concentration was significantly increased by maternal vitamin D supplementation (mean difference, 22.48 nmol/L; 95% confidence interval, 15.90-29.06 nmol/L) with high heterogeneity (I2 = 98.8%, P < .0001). No effects on cord blood calcium concentration was reported (mean difference, 0.05 mmol/L; 95% confidence interval, -0.04-0.13 mmol/L). Supplementation regimens and the different control groups may be the major sources of heterogeneity. Vitamin D supplementation during pregnancy can improve cord blood 25(OH)D concentration in women with low 25(OH)D concentration, but does not affect cord blood calcium concentration. Future researches are needed to evaluate the effect of maternal vitamin D supplementation in women with a normal 25(OH)D concentration and explore the combined effects of vitamin D, calcium, and multivitamins. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of elevated atmospheric CO2 concentrations, clipping regimen and differential day/night atmospheric warming on tissue nitrogen concentrations of a perennial pasture grass

PubMed Central

Volder, Astrid; Gifford, Roger M.; Evans, John R.

2015-01-01

Forecasting the effects of climate change on nitrogen (N) cycling in pastures requires an understanding of changes in tissue N. We examined the effects of elevated atmospheric CO2 concentration, atmospheric warming and simulated grazing (clipping frequency) on aboveground and belowground tissue N concentrations and C : N ratios of a C3 pasture grass. Phalaris aquatica L. cv. ‘Holdfast’ was grown in the field in six transparent temperature gradient tunnels (18 × 1.5 × 1.5 m each), three at ambient atmospheric CO2 and three at 759 p.p.m. CO2. Within each tunnel, there were three air temperature treatments: ambient control, +2.2/+4.0 °C above ambient day/night warming and +3.0 °C continuous warming. A frequent and an infrequent clipping treatment were applied to each warming × CO2 combination. Green leaf N concentrations were decreased by elevated CO2 and increased by more frequent clipping. Both warming treatments increased leaf N concentrations under ambient CO2 concentrations, but did not significantly alter leaf N concentrations under elevated CO2 concentrations. Nitrogen resorption from leaves was decreased under elevated CO2 conditions as well as by more frequent clipping. Fine root N concentrations decreased strongly with increasing soil depth and were further decreased at the 10–60 cm soil depths by elevated CO2 concentrations. The interaction between the CO2 and warming treatments showed that leaf N concentration was affected in a non-additive manner. Changes in leaf C : N ratios were driven by changes in N concentration. Overall, the effects of CO2, warming and clipping treatments on aboveground tissue N concentrations were much greater than on belowground tissue. PMID:26272874

Differential effect of buffering agents on the crystallization of gemcitabine hydrochloride in frozen solutions.

PubMed

Patel, Mehulkumar; Munjal, Bhushan; Bansal, Arvind K

2014-08-25

The purpose of this study was to evaluate the differential effect of buffering agents on the crystallization of gemcitabine hydrochloride (GHCl) in frozen solutions. Four buffering agents, viz. citric acid (CA), malic acid (MA), succinic acid (SA) and tartaric acid (TA) were selected and their effect on GHCl crystallization was monitored using standard DSC and low temperature XRD. Onset of GHCl crystallization during heating run in DSC was measured to compare the differential effect of buffering agents. Glass transition temperature (Tg'), unfrozen water content in the freeze concentrate and crystallization propensity of the buffering agents was also determined for mechanistic understanding of the underlying effects. CA and MA inhibited while SA facilitated crystallization of GHCl even at 25 mM concentration. Increasing the concentration enhanced their effect. However, TA inhibited GHCl crystallization at concentrations <100mM and facilitated it at concentrations ≥100 mM. Lyophilization of GHCl with either SA or TA yielded elegant cakes, while CA and MA caused collapse. Tg' failed to explain the inhibitory effects of CA, MA and TA as all buffering agents lowered the Tg' of the system. Differential effect of buffering agents on GHCl crystallization could be explained by consideration of two opposing factors: (i) their own crystallization tendency and (ii) unfrozen water content in the freeze concentrate. In conclusion, it was established that API crystallization in frozen solution is affected by the type and concentration of the buffering agents. Copyright © 2014 Elsevier B.V. All rights reserved.

Ammonium removal using algae-bacteria consortia: the effect of ammonium concentration, algae biomass, and light.

PubMed

Jia, Huijun; Yuan, Qiuyan

2018-04-01

In this study, the effects of ammonium nitrogen concentration, algae biomass concentration, and light conditions (wavelength and intensity) on the ammonium removal efficiency of algae-bacteria consortia from wastewater were investigated. The results indicated that ammonium concentration and light intensity had a significant impact on nitrification. It was found that the highest ammonia concentration (430 mg N/L) in the influent resulted in the highest ammonia removal rate of 108 ± 3.6 mg N/L/days, which was two times higher than the influent with low ammonia concentration (40 mg N/L). At the lowest light intensity of 1000 Lux, algae biomass concentration, light wavelength, and light cycle did not show a significant effect on the performance of algal-bacterial consortium. Furthermore, the ammonia removal rate was approximately 83 ± 1.0 mg N/L/days, which was up to 40% faster than at the light intensity of 2500 Lux. It was concluded that the algae-bacteria consortia can effectively remove nitrogen from wastewater and the removal performance can be stabilized and enhanced using the low light intensity of 1000 Lux that is also a cost-effective strategy.

Performance optimization of dense-array concentrator photovoltaic system considering effects of circumsolar radiation and slope error.

PubMed

Wong, Chee-Woon; Chong, Kok-Keong; Tan, Ming-Hui

2015-07-27

This paper presents an approach to optimize the electrical performance of dense-array concentrator photovoltaic system comprised of non-imaging dish concentrator by considering the circumsolar radiation and slope error effects. Based on the simulated flux distribution, a systematic methodology to optimize the layout configuration of solar cells interconnection circuit in dense array concentrator photovoltaic module has been proposed by minimizing the current mismatch caused by non-uniformity of concentrated sunlight. An optimized layout of interconnection solar cells circuit with minimum electrical power loss of 6.5% can be achieved by minimizing the effects of both circumsolar radiation and slope error.

The effect of plant sterols on serum triglyceride concentrations is dependent on baseline concentrations: a pooled analysis of 12 randomised controlled trials.

PubMed

Demonty, Isabelle; Ras, Rouyanne T; van der Knaap, Henk C M; Meijer, Linsie; Zock, Peter L; Geleijnse, Johanna M; Trautwein, Elke A

2013-02-01

Plant sterols (PS) are well known for their low-density lipoprotein cholesterol-lowering effect. Until recently, they were believed to have little or no impact on blood triglycerides (TG). However, studies taken individually were possibly lacking statistical power to detect modest TG decreases. This study was performed to quantify the TG-lowering effect of PS by pooling individual subject data from 12 randomised controlled trials that investigated the effects of PS on blood lipids. The main outcome variable was the control-adjusted PS effect on relative (%) and absolute (mmol/L) changes in TG. The relative and absolute changes in high-density lipoprotein cholesterol (HDL-C) were also assessed. Differences in changes of serum lipid concentrations between PS and control treatments were estimated by an ANCOVA using a random effect model which included PS intake (active or control), study and predefined subject characteristics. The twelve randomised controlled trials included in total 935 hypercholesterolaemic subjects not preselected based on their baseline TG concentrations. In most studies, the PS dose ranged between 1.6 and 2.5 g/day. PS intake significantly lowered serum TG by 6.0% (95% CI: -10.7, -1.2) or 0.12 mmol/L (95% CI: -0.20, -0.04). No significant interaction was observed between PS intake and baseline TG concentrations on relative changes, but, on absolute changes, interaction was significant with larger TG decreases observed with higher TG concentrations at baseline. No effects were observed on HDL-C concentrations. These results show that PS exert a modest TG-lowering effect which is dependent on baseline concentrations.

Effects of intravenous temazepam. II. A study of the long-term reproducibility of pharmacokinetics, pharmacodynamics, and concentration-effect parameters.

PubMed

van Steveninck, A L; Schoemaker, H C; den Hartigh, J; Pieters, M S; Breimer, D D; Cohen, A F

1994-05-01

To evaluate the long-term reproducibility of pharmacokinetic, pharmacodynamic, and concentration-effect parameters after intravenous administration of temazepam. Nine healthy volunteers were studied. Temazepam, 0.4 mg/kg, was infused intravenously for 30 minutes on two occasions 6 months apart. Venous plasma concentrations of temazepam were measured by HPLC in samples obtained between 0 and 24 hours. Pharmacodynamic effects were evaluated up to 8 hours for saccadic peak velocity and electroencephalogram (EEG) beta amplitudes. Subjects' state and trait anxiety were assessed by use of the Spielberger anxiety inventory. Significant correlations between occasions were found for area under the plasma concentration-time curve (AUC) values (r = 0.91; p < 0.01) but not for maximum concentration and half-life. Significant correlations were also found for area under the effect-time curve (AUEC) values of peak velocity (r = 0.88; p < 0.01) but not for peak velocity (r = 0.48; p > 0.05). Significant differences between the slopes of concentration effect plots on different occasions were observed in two subjects for EEG beta and in three subjects for peak velocity, with one subject showing a similar change for both parameters. Trait anxiety scores were higher on the first occasion (33 +/- 7) than on the second occasion (29 +/- 7; p < 0.01). A negative correlation was found between trait anxiety scores and the slopes of concentration-effect plots for peak velocity (r = -0.63; p < 0.01). For AUC and AUEC values the results indicate a reasonable long-term reproducibility of differences between subjects in the pharmacokinetics and pharmacodynamics of temazepam. However, there were limitations to the predictive value of derived concentration-effect parameters.

The effect of isoenzyme-selective PDE inhibitors on methacholine-induced contraction of guinea-pig and rat ileum.

PubMed Central

Tomkinson, A.; Raeburn, D.

1996-01-01

1. We have examined the effects of the isoenzyme-selective phosphodiesterase (PDE) inhibitors, vinpocetine (type 1), siguazodan (type 3), rolipram (type 4) and zaprinast (type 5) and the non-selective PDE inhibitor enprofylline on methacholine (MCh) contractile concentration-response curves on guinea-pig and rat isolated ileum. 2. In guinea-pig ileum, vinpocetine (10-300 microM), zaprinast (1-300 microM) and enprofylline (100-1000 microM) produced a concentration-dependent depression of the maximum response (Emax) to MCh only without effect on the MCh EC50 values (rank order of potency: zaprinast > vinpocetine > enprofylline). In contrast, siguazodan (10-300 microM) and rolipram (10-300 microM) produced a rightward displacement of the MCh concentration-response curve (increase in EC50: rank order; rolipram > siguazodan), with effects on the MCh maximum seen only at higher concentrations. 3. In the rat ileum, vinpocetine (10-300 microM), zaprinast (0.1-300 microM) and enprofylline (100-1000 microM) caused depression of the MCh maximum contraction (rank order: zaprinast > vinpocetine > enprofylline). Low concentrations of rolipram and siguazodan had no significant effect on the MCh maximum. In the presence of higher concentrations (> 100 microM) of rolipram and siguazodan, a maximum response was not achieved at the highest concentration of MCh tested. As in the guinea-pig ileum, only rolipram (10-300 microM) and siguazodan (10-300 microM) produced a significant, concentration-dependent, rightward displacement of the MCh concentration-response curve (increase in EC50: rank order: rolipram > siguazodan). 4. In the guinea-pig ileum, isoprenaline (0.1 microM) produced a rightward displacement (approximately 3 fold) of the MCh concentration-response curve, accompanied by a significant depression of the maximum response. Increasing the isoprenaline concentration (1 microM) had no further effect on either parameter. Sodium nitroprusside (SNP, > or = 10 microM) produced a concentration-dependent depression of the MCh maximum without an effect on the EC50. 5. In the rat ileum, isoprenaline (1 microM) produced a concentration-dependent rightward displacement (approximately 2.8 fold) of the MCh concentration-response curve with depression of the MCh maximum at higher (> or = 100 microM) concentrations. SNP produced depression of the MCh maximum at a concentration of 10 microM and above. Effects on the MCh EC50 were seen only at 100 and 300 microM. 6. In guinea-pig ileum, isoprenaline (0.1 microM) in combination with rolipram (10 microM) further increased the MCh EC50 and reduced the MCh maximum. The combination of SNP (10 microM) with zaprinast (0.1 microM) produced no further significant effect than SNP alone. 7. In rat ileum, isoprenaline (1 microM) in combination with rolipram (10 microM) further increased the EC50 and reduced the maximum. SNP (10 microM) had no significant effect on either the MCh maximum or EC50. A combination with zaprinast (1 microM) had no further effect. 8. In conclusion, all the PDE inhibitors tested produced a concentration-dependent inhibition of the MCh concentration-response curve, indicating a modulator role for the PDE isoenzymes in gastrointestinal smooth muscle contractility. The PDE inhibitors that elevate cyclic GMP produced a depression of the MCh maximum response only, whilst those that elevate cyclic AMP produced a rightward displacement of the MCh concentration-response curve. This was confirmed by the use of isoprenaline and SNP. This difference in the type of inhibition produced by these PDE isoenzyme inhibitors may reflect a different intracellular site/mechanism by which the cyclic AMP- and cyclic GMP-activated kinases act functionally to antagonize the contractile response. PMID:8864552

Rapid Response Concentration-Controlled Desorption of Activated Carbon to Dampen Concentration Fluctuations

DTIC Science & Technology

2007-01-01

Behavior of trickle - bed air biofilter for toluene removal: Effect of non-use periods. Environ. Prog. 2005, 24, 155-161. (3) Martin, F. J.; Loehr, R. C...dampen the fluctuation in acetone concentration at high concentrations. The effect of inlet concentration and empty bed contact time (EBCT) on dampening...oxidizer. The MSA-SST system is a fixed- bed system that rapidly controls the power that heats the adsorbent/adsorbate, resulting in controlled

The effect of solute concentration on hindered gradient diffusion in polymeric gels

NASA Astrophysics Data System (ADS)

Buck, Kristan K. S.; Dungan, Stephanie R.; Phillips, Ronald J.

1999-10-01

The effect of solute concentration on hindered diffusion of sphere-like colloidal solutes in stiff polymer hydrogels is examined theoretically and experimentally. In the theoretical development, it is shown that the presence of the gel fibres enhances the effect of concentration on the thermodynamic driving force for gradient diffusion, while simultaneously reducing the effect of concentration on the hydrodynamic drag. The result is that gradient diffusion depends more strongly on solute concentration in gels than it does in pure solution, by an amount that depends on the partition coefficient and hydraulic permeability of the gel solute system. Quantitative calculations are made to determine the concentration-dependent diffusivity correct to first order in solute concentration. In order to compare the theoretical predictions with experimental data, rates of diffusion have been measured for nonionic micelles and globular proteins in solution and agarose hydrogels at two gel concentrations. The measurements were performed by using holographic interferometry, through which one monitors changes in refractive index as gradient diffusion takes place within a transparent gel. If the solutes are modelled as spheres with short-range repulsive interactions, then the experimentally measured concentration dependence of the diffusivities of both the protein and micelles is in good agreement with the theoretical predictions.

Effects of furosemide on hemorheologic alterations induced by incremental treadmill exercise in thoroughbreds.

PubMed

Weiss, D J; Geor, R J; Burger, K

1996-06-01

To determine whether furosemide treatment altered the blood flow properties and serum and RBC electrolyte concentrations of Thoroughbreds during submaximal treadmill exercise. Thoroughbreds were subjected to submaximal treadmill exercise with and without treatment with furosemide (1 mg/kg of body weight, IV). 5 healthy Throughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage. Venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 10 minutes after exercise, and hemorheologic and electrolyte test results were determined. Hemorheologic changes 60 minutes after furosemide administration included increased PCV, plasma total protein concentration, whole blood viscosity, mean RBC volume, and RBC potassium concentration, and decreased serum potassium concentration, serum chloride concentration, and RBC chloride concentration. Furosemide treatment attenuated the exercise-associated changes in RBC size, serum sodium concentration, serum potassium concentration, RBC potassium and chloride concentrations, and RBC density; exacerbated exercise-associated increases in whole blood viscosity; and had no effect on RBC filterability. The hemorheologic effects of furosemide probably occurred secondary to total body and transmembrane fluid and electrolyte fluxes and would not improve blood flow properties. The beneficial effects of furosemide treatment in reducing the severity of bleeding in horses with exercise-induced pulmonary hemorrhage cannot be explained by improved blood flow properties.

Effects of Glyphosate-Based Herbicide Sub-Lethal Concentrations on Fish Feeding Behavior.

PubMed

Giaquinto, Percilia Cardoso; de Sá, Marina Borges; Sugihara, Vanessa Seiko; Gonçalves, Bruno Bastos; Delício, Helton Carlos; Barki, Assaf

2017-04-01

Glyphosate-based herbicides are widely used in agricultural systems. Although the target organism are particularly plant organisms, there are numerous studies showing adverse effects in aquatic animals, such as inhibition of acetyl cholinesterase, effects on kidney, liver, and gill and stressors effects. This study analyzed the effects of commercial formulation of glyphosate on feeding behavior in Pacu (Piaractus mesopotamicus). Fish were exposed to three glyphosate concentrations (0.2, 0.6, and 1.8 ppm) for 15 days. At concentrations of 0.2 and 0.6 ppm, food intake decreased on day 13 and then returned to normal on day 15. At the highest glyphosate-based herbicide concentration, 1.8 ppm, food consumption decreased dramatically and did not recover on day 15. This study showed that glyphosate-based herbicide at sub-lethal concentrations can affect feed intake in pacu and consequently inhibits its growth.

Rhodiola sacra aqueous extract (RSAE) improves biochemical and sperm characteristics in cryopreserved boar semen.

PubMed

Zhao, H-W; Li, Q-W; Ning, G-Z; Han, Z-S; Jiang, Z-L; Duan, Y-F

2009-03-15

Although Rhodiola sacra aqueous extract (RSAE) has been used in many studies as an antioxidant, its effects on semen characteristics and its antioxidant properties during cryopreservation of boar sperm have never been evaluated. Semen was collected from five Duroc boars (2-4-year-old) twice weekly and frozen-thawed in extender with RSEA. Motion characteristics were assessed with a computer-aided semen analysis (CASA) system, whereas other sperm quality end points were assessed by routine methods. The effective concentration of RSEA in extender ranged from 4 to 8mg/L and the effect of RSEA on sperm quality was better in glycerol-free extender than extender containing glycerol (P<0.05). In frozen-thawed boar semen, there was a direct correlation (P<0.05) between RSEA concentration and glutathione (GSH) concentrations, mitochondrial activity, and hypoosmotic swelling test (HOST), and an inverse correlation (r=-0.982, P<0.05) between RSEA concentration and malondialdehyde (all end points were significantly higher at 6mg/L than in the control group). In summary: (i) the effective concentration of RSEA in extender ranged from 4 to 8mg/L; (ii) the effect of RSEA on sperm quality was better in extender without glycerol; and (iii) there was a significant correlation between RSEA concentrations and concentrations of GSH and MAD in frozen-thawed boar semen (antioxidant effects of RSEA were concentration-dependent). Further studies are needed to define the active ingredient in RSEA that protects boar sperm against ROS.

A suggested mechanism for aluminum biotoxicity.

PubMed

Forbes, W F; Agwani, N

1994-11-21

Following earlier work on the relevance of silica (SiO2) and fluoride (F) to the biotoxicity of aluminum (Al), it is shown that relatively high risks of a measure of mental impairment are frequently associated with relatively low SiO2 and F in the drinking water available in different parts of Ontario. Also, because of a negative association between SiO2 and F concentrations in the treated water available in different municipalities, a low SiO2 concentration can account for the observed association involving high F concentrations, and low F concentrations can similarly account for associations involving high SiO2 concentrations. In the light of these observations, the biotoxic effects at low Al concentrations can be explained by assuming that interactions occur with membranes. Such interactions may be less likely at higher SiO2 and F concentrations, because at these concentrations, interactions between Al-, SiO2- and F-containing species are more important. Generally, the various associations with a measure of mental impairment can be explained on the assumption that F exerts a protective effect against the biotoxic effects of Al, as does SiO2 under certain conditions, but the effects of SiO2 only become important at higher SiO2 concentrations. The results from this and other studies suggest that the neurotoxic effects of Al depend on other water constituents. The results also indicate that absorption through the lung or skin, rather than through the stomach or the bowel, can better explain the reported associations.

Effects of the Deregulation on the Concentration of the Brazilian Air Transportation Industry

NASA Technical Reports Server (NTRS)

Guterres, Marcelo Xavier; Muller, Carlos

2003-01-01

This paper addresses the effects of the deregulation of the Brazilian air transportation industry in terms of the concentration of the market. We will show some metrics that are commonly used to study the concentration of the industry. This paper uses the Herfindhal- Hirschman Index. This index tends to zero in the competitive scenario, with a large number of small firms, and to one in case of a monopolistic scenario. The paper analyses the dynamics of the concentration of the Brazilian domestic air transportation market, in order to evaluate the effects of deregulation. We conclude that the Brazilian market presents oligopoly characteristics and aspects in its current structure that maintain the market concentrated in spite of the Deregulation measures adopted by the aeronautical authority. Keywords: Herfindhal-Hirschman Index, concentration, Deregulation

Effect of laparotomy on the pituitary-adrenal axis in dogs.

PubMed

Skovira, Emily J; Behrend, Ellen N; Martin, Linda G; Palmer, Lee E; Kemppainen, Robert J; Lee, Hollie P

2017-08-01

OBJECTIVE To assess effects of major abdominal surgery on serum cortisol and aldosterone and plasma canine ACTH (cACTH) concentrations. ANIMALS 39 healthy dogs undergoing laparotomy during veterinary student surgical laboratories. PROCEDURES Blood samples were obtained before and at completion of surgery. Serum cortisol and aldosterone and plasma cACTH concentrations were measured by use of validated radioimmunoassays. Changes in concentrations (postoperative concentration minus preoperative concentration) were calculated. Data were analyzed by use of the Wilcoxon signed rank test, Pearson correlation analysis, and Mann-Whitney rank sum test. RESULTS Cortisol, aldosterone, and cACTH concentrations increased significantly from before to after surgery. Although cortisol and aldosterone concentrations increased in almost all dogs, cACTH concentrations decreased in 6 of 32 (19%) dogs. All dogs had preoperative cortisol concentrations within the reference range, but 24 of 39 (62%) dogs had postoperative concentrations above the reference range. A correlation between the change in cACTH concentration and the change in cortisol concentration was not detected. CONCLUSIONS AND CLINICAL RELEVANCE Laparotomy caused a significant increase in serum cortisol and aldosterone concentrations. In most dogs, but not all dogs, plasma cACTH concentrations increased. Lack of correlation between the change in cACTH concentration and the change in cortisol concentration suggested that increased postoperative cortisol concentrations may have been attributable to ACTH-independent mechanisms, an early ACTH increase that caused a sustained cortisol release, or decreased cortisol clearance. Further studies are indicated to evaluate the effects of various anesthetic protocols and minimally invasive surgical techniques on the stress response.

Therapeutic effects of various concentrations of lincomycin in drinking water on experimentally transmitted swine dysentery.

PubMed

Hamdy, A H

1978-07-01

Three experimental studies were conducted in 232 growing pigs (8 to 12 weeks old) to evaluate the therapeutic effects of various concentrations of lincomycin in drinking water, against swine dysentery experimentally transmitted, by oral inoculation or by contact-commingling exposure. Four or 5 concentrations of lincomycin were used in each experiment (132, 66, 33, 16.5 or 0.0 mg/L of drinking water). Medication was initiated 7 to days after exposure and was continued for 6 to 10 days. Both methods of exposure were capable of transmitting the disease successfully. A more marked dose response was noticed in pigs inoculated orally than in pigs that were exposed by contact. All concentrations of lincomycin were effective for the treatment of swine dysentery by oral or by contact exposure. At the smaller concentration of 16.5 mg/L of drinking water, lincomycin was less effective for treating the disease than it was at greater concentrations. The suggested optimal concentration was 33 mg of lincomycin/L of drinking water for the treatment of swine dysentery.

Increased chemerin concentrations in fetuses of obese mothers and correlation with maternal insulin sensitivity.

PubMed

Barker, Gillian; Lim, Ratana; Rice, Gregory E; Lappas, Martha

2012-11-01

The aim of this study was to determine the effect of maternal obesity and gestational diabetes mellitus (GDM) on (i) the circulating concentrations of chemerin in cord and maternal plasma, and (ii) gene expression and release of chemerin from human placenta and adipose tissue. Chemerin concentrations were measured in maternal and cord plasma from 62 normal glucose tolerant women (NGT) and 69 women with GDM at the time of term elective Caesarean section. Placenta and adipose tissue expression and release of chemerin was measured from 22 NGT and 22 GDM women. There was no effect of maternal obesity or GDM on maternal chemerin concentrations. Chemerin concentrations were significantly higher in cord plasma from women with maternal obesity. Cord chemerin concentrations in NGT women negatively correlated with the concentrations of maternal insulin sensitivity. There was no effect of GDM on maternal and cord chemerin concentrations, and on the release of chemerin from placenta and adipose tissue. At the time of term Caesarean section, preexisting maternal obesity, and its associated insulin resistance, is associated with higher cord plasma chemerin concentrations.

Effects of weather on the retrieval of sea ice concentration and ice type from passive microwave data

NASA Technical Reports Server (NTRS)

Maslanik, J. A.

1992-01-01

Effects of wind, water vapor, and cloud liquid water on ice concentration and ice type calculated from passive microwave data are assessed through radiative transfer calculations and observations. These weather effects can cause overestimates in ice concentration and more substantial underestimates in multi-year ice percentage by decreasing polarization and by decreasing the gradient between frequencies. The effect of surface temperature and air temperature on the magnitudes of weather-related errors is small for ice concentration and substantial for multiyear ice percentage. The existing weather filter in the NASA Team Algorithm addresses only weather effects over open ocean; the additional use of local open-ocean tie points and an alternative weather correction for the marginal ice zone can further reduce errors due to weather. Ice concentrations calculated using 37 versus 18 GHz data show little difference in total ice covered area, but greater differences in intermediate concentration classes. Given the magnitude of weather-related errors in ice classification from passive microwave data, corrections for weather effects may be necessary to detect small trends in ice covered area and ice type for climate studies.

Effect of gold nanoparticles on the fluorescence excitation spectrum of α-fetoprotein: Local environment dependent fluorescence quenching

NASA Astrophysics Data System (ADS)

Li, Jian-jun; Chen, Yu; Wang, A.-qing; Zhu, Jian; Zhao, Jun-wu

2011-01-01

The effect of colloid gold nanoparticles (AuNPs) on the fluorescence excitation spectrum of α-fetoprotein (AFP) has been investigated experimentally. The excitation spectral peaks of AFP with low concentration from 0.01 ng ml -1 to 12 ng ml -1 increase monotonically with increasing of AFP concentration. When some gold colloids were added to the AFP solution, the excitation peak at 285 nm decreases distinctly. By comparing the excitation peak intensity of AFP solution with gold colloids and without gold colloids at different AFP concentrations, the quenching effect from gold nanoparticle was more effective at lower AFP concentration. So the range of concentration from 0.01 ng ml -1 to 0.09 ng ml -1 will be the potential range of applications because of the higher sensitivity. The physical origin based on local field effect was investigated to illuminate this local environment dependent fluorescence quenching. The changing extent of quenching with different AFP concentrations can be attributed to the nonlinear decreasing of the local field factor of gold nanoparticles as a function of environmental dielectric constant.

Intrinsic Carrier Concentration and Electron Effective Mass in Hg(1-x) Zn(x) Te

NASA Technical Reports Server (NTRS)

Sha, Yi-Gao; Su, Ching-Hua; Lehoczky, S. L.

1997-01-01

In this work, the intrinsic carrier concentration and electron effective mass in Hg(l-x)Zn(x)Te were numerically calculated. We adopt the procedures similar to those used by Su et. al. for calculating intrinsic carrier concentrations in Hg(1-x)Cd(x)Te which solve the exact dispersion relation in Kane model for the calculation of the conduction band electron concentrations and the corresponding electron effective masses. No approximation beyond those inherent in the k centered dot p model was used here.

The Effect of Initial Cell Concentration on Xylose Fermentation by Pichia stipitis

NASA Astrophysics Data System (ADS)

Agbogbo, Frank K.; Coward-Kelly, Guillermo; Torry-Smith, Mads; Wenger, Kevin; Jeffries, Thomas W.

Xylose was fermented using Pichia stipitis CBS 6054 at different initial cell concentrations. A high initial cell concentration increased the rate of xylose utilization, ethanol formation, and the ethanol yield. The highest ethanol concentration of 41.0 g/L and a yield of 0.38 g/g was obtained using an initial cell concentration of 6.5 g/L. Even though more xylitol was produced when the initial cell concentrations were high, cell density had no effect on the final ethanol yield. A two-parameter mathematical model was used to predict the cell population dynamics at the different initial cell concentrations. The model parameters, a and b correlate with the initial cell concentrations used with an R 2 of 0.99.

Effect of ingested concentrate and components of sake on epidermal permeability barrier disruption by UVB irradiation.

PubMed

Hirotsune, Masato; Haratake, Akinori; Komiya, Aya; Sugita, Jun; Tachihara, Toru; Komai, Tsuyoshi; Hizume, Kazuhisa; Ozeki, Kenji; Ikemoto, Takeshi

2005-02-23

Daily topical applications of the concentrate of sake (CS) have been shown to reduce epidermal barrier disruption in murine skin caused by ultraviolet B (UVB) radiation, while one of the components of sake, ethyl alpha-D-glucoside (alpha-EG), also reduces barrier disruption. We confirmed the effect of oral ingestion of various doses of CS on epidermal barrier disruption caused by UVB irradiation in hairless mice. Then, to identify the effective components, we quantitatively analyzed alpha-EG, organic acids, and glycerol, the main components of CS, and examined the effect of various concentration of each on barrier disruption. alpha-EG and organic acids showed comparable results to CS itself, and transepidermal water loss levels in murine skin were significantly decreased as compared with the control. Furthermore, an investigation of the dose dependency of these agents was performed and the results showed the significant effectiveness of alpha-EG. In addition, red wine concentrate (WC) and beer concentrate (BC) were examined in order to confirm the unique effects of CS. Similar effects were not found with WC and BC.

The Possible Pre- and Post-UVA Radiation Protective Effect of Amaranth Oil on Human Skin Fibroblast Cells.

PubMed

Wolosik, Katarzyna; Zareba, Ilona; Surazynski, Arkadiusz; Markowska, Agnieszka

2017-07-01

The health effects of Amaranth Oil (AO) are attributed to its specific chemical composition. That makes it an outstanding natural product for the prevention and treatment of ultraviolet (UV) irradiation-related pathologies such as sunburn, photoaging, photoimmunosuppression, and photocarcinogenesis. Most of the studies are taken on animal model, and there is a lack of research on the endogenous effect of AO on fibroblast level, where UVA takes it harmful place. The aim of this study was evaluation if AO can protect or abolish UVA exposure effect on human skin fibroblast. The 0.1% AO, 0.25% AO, and 0.5% AO concentration and irradiation for 15 min under UVA-emitting lamp were studied in various condition. In all experiments, the mean values for six assays ± standard deviations were calculated. Pretreatment with various concentrations of AO was tested. The highest concentration of AO where cell survival was observed was 0.5%. Cytotoxicity assays provided evidence for pre- and post-UVA protective effect of 0.1% AO among three tested concentrations. The results also provide evidence that UVA has inhibitory effect on collagen biosynthesis in confluent skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect comparing to other used AO concentration. The assessment results on DNA biosynthesis show the significant abolished post-UVA effect when 0.1% and 0.5% of AO were added. AO gives pre- and post-UVA protection in low concentration. This provides the evidence for using it not as a main protective factor against UV but as one of the combined components in cosmetic formulation. The recommended Amaranth Oil (AO) concentration in cosmetic formulation is between 0.1 and 5%Pretreatment with various concentrations of AO suggests to use the highest 0.5% concentration of AO in human skin fibroblast culturesThe 0.1% of AO in fibroblast cultures, protects and abolishes effect of ultraviolet A (UVA) exposureUVA has inhibitory effect on collagen biosynthesis in skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effectThe abolished post-UVA effect occurs when 0.1% and 0.5% of AO were added on DNA biosynthesis. Abbreviations used: AO: Amaranth Oil.

Effect of Nitrite/Nitrate concentrations on Corrosivity of Washed Precipitate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Congdon, J.W.

2001-03-28

Cyclic polarization scans were performed using A-537 carbon steel in simulated washed precipitate solutions of various nitrite and nitrate concentrations. The results of this study indicate that nitrate is an aggressive anion in washed precipitate. Furthermore, a quantitative linear log-log relationship between the minimum effective nitrite concentration and the nitrate concentration was established for washed precipitate with other ions at their average compositions.

Fertility-dependent effects of ectomycorrhizal fungal communities on white spruce seedling nutrition.

PubMed

Smith, Alistair J H; Potvin, Lynette R; Lilleskov, Erik A

2015-11-01

Ectomycorrhizal fungi (EcMF) typically colonize nursery seedlings, but nutritional and growth effects of these communities are only partly understood. To examine these effects, Picea glauca seedlings collected from a tree nursery naturally colonized by three dominant EcMF were divided between fertilized and unfertilized treatments. After one growing season seedlings were harvested, ectomycorrhizas identified using DNA sequencing, and seedlings analyzed for leaf nutrient concentration and content, and biomass parameters. EcMF community structure-nutrient interactions were tested using nonmetric multidimensional scaling (NMDS) combined with vector analysis of foliar nutrients and biomass. We identified three dominant species: Amphinema sp., Atheliaceae sp., and Thelephora terrestris. NMDS + envfit revealed significant community effects on seedling nutrition that differed with fertilization treatment. PERMANOVA and regression analyses uncovered significant species effects on host nutrient concentration, content, and stoichiometry. Amphinema sp. had a significant positive effect on phosphorus (P), calcium and zinc concentration, and P content; in contrast, T. terrestris had a negative effect on P concentration. In the unfertilized treatment, percent abundance of the Amphinema sp. negatively affected foliar nitrogen (N) concentration but not content, and reduced foliar N/P. In fertilized seedlings, Amphinema sp. was positively related to foliar concentrations of N, magnesium, and boron, and both concentration and content of manganese, and Atheliaceae sp. had a negative relationship with P content. Findings shed light on the community and species effects on seedling condition, revealing clear functional differences among dominants. The approach used should be scalable to explore function in more complex communities composed of unculturable EcMF.

Photovoltaic performance of the dome-shaped Fresnel-Köhler concentrator

NASA Astrophysics Data System (ADS)

Zamora, Pablo; Benítez, Pablo; Yang, Li; Miñano, Juan Carlos; Mendes-Lopes, Joao; Araki, Kenji

2012-10-01

In order to have a cost-effective CPV system, two key issues must be ensured: high concentration factor and high tolerance. The novel concentrator we are presenting, the dome-shaped Fresnel-Köhler, can widely fulfill these two and other essential issues in a CPV module. This concentrator is based on two previous successful CPV designs: the FK concentrator with a flat Fresnel lens and the dome-shaped Fresnel lens system developed by Daido Steel, resulting on a superior concentrator. The concentrator has shown outstanding simulation results, achieving an effective concentration-acceptance product (CAP) value of 0.72, and an optical efficiency of 85% on-axis (no anti-reflective coating has been used). Moreover, Köhler integration provides good irradiance uniformity on the cell surface and low spectral aberration of this irradiance. This ensures an optimal performance of the solar cell, maximizing its efficiency. Besides, the domeshaped FK shows optimal results for very compact designs, especially in the f/0.7-1.0 range. The dome-shaped Fresnel- Köhler concentrator, natural and enhanced evolution of the flat FK concentrator, is a cost-effective CPV optical design, mainly due to its high tolerances. Daido Steel advanced technique for demolding injected plastic pieces will allow for easy manufacture of the dome-shaped POE of DFK concentrator.

Effects of dietary oat, barley, and guar gums on serum and liver lipid concentrations in diet-induced hypertriglyceridemic rats.

PubMed

Oda, T; Aoe, S; Imanishi, S; Kanazawa, Y; Sanada, H; Ayano, Y

1994-04-01

Effects of dietary oat, barley, and guar gums on serum and liver triglyceride or cholesterol concentrations were examined in diet-induced hypertriglyceridemic rats. Male Sprague-Dawley rats were fed a hypertriglyceridemic diet that contained 20% coconut oil, 17.5% fructose, 17.5% sucrose, and 5% cellulose at 4 weeks of age for 14 days. In the gum-supplemented diets, 2% cellulose was replaced by oat gum, barley gum, or guar gum. Hypertriglyceridemia was observed in the control group, whereas serum cholesterol concentration was not increased. All of the gums lowered serum and liver cholesterol concentrations except barley gum which had no significant effect on liver cholesterol. Both oat and barley gums suppressed the elevation of serum and liver triglyceride concentrations but guar gum had no effect.

Treatment with clozapine and its effect on plasma homovanillic acid and norepinephrine concentrations in schizophrenia.

PubMed

Davidson, M; Kahn, R S; Stern, R G; Hirschowitz, J; Apter, S; Knott, P; Davis, K L

1993-02-01

Measurement of plasma concentrations of the dopamine metabolite, homovanillic acid (pHVA), is an indirect tool to assess changes in dopamine turnover. Levels of pHVA have been reported to decrease during treatment with conventional antidopaminergic, neuroleptics, with the decrement correlating with symptomatic improvement in schizophrenic symptoms. Clozapine, an atypical neuroleptic, is the only drug proved to be effective in treatment-refractory patients. However, the mechanism mediating this unique efficacy has not been fully elucidated. This study examined the effect of clozapine on pHVA concentrations in schizophrenic patients. Since clozapine potently binds to alpha 2-adrenergic receptors, plasma norepinephrine (pNE) concentrations were also measured. Twenty-eight treatment-refractory schizophrenic patients (24 men, 4 women) were treated with clozapine (up to 600 mg/day) for 5 weeks, after a minimum 1-week drug-free period. Symptomatology and pHVA and pNE concentrations were measured at the last drug-free day and weekly for 5 weeks. Fourteen patients responded to clozapine treatment, while an equal number did not. Mean pHVA concentrations did not significantly change during treatment with clozapine. Although clozapine tended to lower pHVA concentrations in treatment responders, the effect was small and not significant. Clozapine treatment significantly raised pNE concentrations, but this did not differentiate responders from nonresponders to clozapine. These findings suggest that clozapine's effect on DA turnover is small and that clozapine may be effective in treatment-refractory schizophrenia by mechanisms other than, or in addition to, dopamine receptor blockade. However, since about one-third of NE is metabolized into HVA, the clozapine-induced increase in pNE may have overshadowed a possible lowering effect of clozapine on pHVA.

Effects of effluents from a coal-fired, electric-generating powerplant on local ground water near Hayden, Colorado

USGS Publications Warehouse

Ellis, S.R.; Mann, P.G.

1981-01-01

Data were collected at the Hayden, Colo., powerplant for about a year during 1978-79 to monitor the effects of effluent and raw-water storage ponds on the local ground water, Sage Creek, and the Yampa River. The concentration of boron in wells downgradient from the effluent ponds indicated that the ponds were leaking, increasing the average boron concentrations in the ground water to a level in excess of the standards for agricultural use of water. Water from seeps, probably the best indicators of downgradient water quality, had average concentrations of boron two times that of the Colorado Department of Health (1977) standard for agricultural use of water. Chemical analyses of water from wells and the discharge weir downgradient from the raw-water storage ponds indicated these ponds are leaking. The effect of this leakage is that the water in wells downgradient from these ponds has a lower specific conductance and a lower boron concentration than the water in wells downgradient from the effluent ponds. The concentration of trace elements in the water from the wells and the discharge weir generally declined during the study, probably because the ground water was recovering from the effects of a plume from the raw-water pond previously used for fly-ash disposal. The effluents from the Hayden powerplant lowered the specific conductance and the iron and manganese concentrations, increased the concentration of boron, and had little or no effect on the selenium concentration in Sage Creek. Sage Creek had no discernible effect on the Yampa River because the volume of water in the Yampa River was so much greater. The effluents from the powerplant also had no discernible effect on the Yampa River. (USGS)

Effect of temperature & salt concentration on salt tolerant nitrate-perchlorate reducing bacteria: Nitrate degradation kinetics.

PubMed

Ebrahimi, Shelir; Nguyen, Thi Hau; Roberts, Deborah J

2015-10-15

The sustainability of nitrate-contaminated water treatment using ion-exchange processes can be achieved by regenerating the exhausted resin several times. Our previous study shows that the use of multi-cycle bioregeneration of resin enclosed in membrane is an effective and innovative regeneration method. In this research, the effects of two independent factors (temperature and salt concentration) on the biological denitrification rate were studied. The results of this research along with the experimental results of the previous study on the effect of the same factors on nitrate desorption rate from the resin allow the optimization of the bioregeneration process. The results of nitrate denitrification rate study show that the biodegradation rate at different temperature and salt concentration is independent of the initial nitrate concentration. At each specific salt concentration, the nitrate removal rate increased with increasing temperature with the average value of 0.001110 ± 0.0000647 mg-nitrate/mg-VSS.h.°C. However, the effect of different salt concentrations was dependent on the temperature; there is a significant interaction between salt concentration and temperature; within each group of temperatures, the nitrate degradation rate decreased with increasing the salt concentration. The temperature affected the tolerance to salinity and culture was less tolerant to high concentration of salt at low temperature. Evidenced by the difference between the minimum and maximum nitrate degradation rate being greater at lower temperature. At 35 °C, a 32% reduction in the nitrate degradation rate was observed while at 12 °C this reduction was 69%. This is the first published study to examine the interaction of salt concentration and temperature during biological denitrification. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Theobromine Consumption on Serum Lipoprotein Profiles in Apparently Healthy Humans with Low HDL-Cholesterol Concentrations

PubMed Central

Jacobs, Doris M.; Smolders, Lotte; Lin, Yuguang; de Roo, Niels; Trautwein, Elke A.; van Duynhoven, John; Mensink, Ronald P.; Plat, Jogchum; Mihaleva, Velitchka V.

2017-01-01

Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH). We have investigated the effect of theobromine (TB) consumption on the concentrations of triglyceride (TG) and cholesterol (CH) in various lipoprotein (LP) subclasses. Methods: In a randomized, double-blind, placebo-controlled, cross-over study, 44 apparently healthy women and men (age: 60 ± 6 years, BMI: 29 ± 3 kg/m2) with low baseline HDL-CH concentrations consumed a drink supplemented with 500 mg/d theobromine for 4 weeks. TG and CH concentrations in 15 LP subclasses were predicted from diffusion-edited 1H NMR spectra of fasting serum. Results: The LP phenotype of the subjects was characterized by low CH concentrations in the large HDL particles and high TG concentrations in large VLDL and chylomicron (CM) particles, which clearly differed from a LP phenotype of subjects with normal HDL-CH. TB only reduced CH concentrations in the LDL particles by 3.64 and 6.79%, but had no effect on TG and CH in any of the HDL, VLDL and CM subclasses. Conclusion: TB was not effective on HDL-CH in subjects with a LP phenotype characterized by low HDL-CH and high TG in VLDL. PMID:28971099

Degree of contamination and sources of polychlorinated biphenyls in Meandering Road Creek and Woods Inlet of Lake Worth, Fort Worth, Texas, 2004 and 2006-07

USGS Publications Warehouse

Braun, Christopher L.; Wilson, Jennifer T.; Van Metre, Peter C.

2008-01-01

Lake Worth is a reservoir on the West Fork Trinity River on the western edge of Fort Worth, Texas. Air Force Plant 4 (AFP4) is on the eastern shore of Woods Inlet, an arm of Lake Worth that extends south from the main body of the lake. Two previous reports documented ele-vated polychlorinated biphenyl (PCB) concentrations in surficial sediment in Woods Inlet relative to those in surficial sediment in other parts of Lake Worth. This report presents the results of another USGS study, done in cooperation with the U.S. Air Force, to indicate the degree of PCB contamination of Meandering Road Creek and Woods Inlet and to identify possible sources of PCBs in Meandering Road Creek and Woods Inlet on the basis of suspended, streambed, and lake-bottom sediment samples collected there in 2004 and 2006-07. About 40 to 80 percent of total PCB concentrations (depending on how total PCB concentration is computed) in suspended sediment exceed the threshold effect concentration, a concentration below which adverse effects to benthic biota rarely occur. About 20 percent of total PCB concentrations (computed as sum of three Aroclors) in suspended sediment exceed the probable effect concentration, a concentration above which adverse effects to benthic biota are expected to occur frequently. About 20 to 30 percent of total PCB concentrations in streambed sediment exceed the threshold effect concentration; and about 6 to 20 percent of total PCB concentrations in lake-bottom (Woods Inlet) sediment exceed the threshold effect concentration. No streambed or lake-bottom sediment concentrations exceed the probable effect concentration. The sources of PCBs to Meandering Road Creek and Woods Inlet were investigated by comparing the relative distributions of PCB congeners of suspended sediment to those of streambed and lake-bottom sediment. The sources of PCBs were identified using graphical analysis of normalized concentrations (congener ratios) of 11 congeners. For graphical analysis, the sampling sites were divided into three groups with each group associated with one of the three outfalls sampled: SSO, OF4, and OF5. The variations of normalized PCB congener concentrations from Woods Inlet, from outfalls along Meandering Road Creek, and from streambed sediment sampling sites along Meandering Road Creek generally form similar patterns within sample groups, which is indicative of a common source of PCBs to each group. Overall, the variations in congener ratios indicate that PCBs in surficial lake-bottom sediment of Woods Inlet probably entered Woods Inlet primarily from Meandering Road Creek, and that runoff from AFP4 is a prominent source of PCBs in Meandering Road Creek. Sixteen of the 20 box core sites in Woods Inlet had lower PCB concentrations in the 2006 cores compared to those in the 2003 cores.

Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls

USGS Publications Warehouse

MacDonald, Donald D.; Dipinto, Lisa M.; Field, Jay; Ingersoll, Christopher G.; Long, Edward R.; Swartz, Richard C.

2000-01-01

Sediment-quality guidelines (SQGs) have been published for polychlorinated biphenyls (PCBs) using both empirical and theoretical approaches. Empirically based guidelines have been developed using the screening-level concentration, effects range, effects level, and apparent effects threshold approaches. Theoretically based guidelines have been developed using the equilibrium-partitioning approach. Empirically-based guidelines were classified into three general categories, in accordance with their original narrative intents, and used to develop three consensus-based sediment effect concentrations (SECs) for total PCBs (tPCBs), including a threshold effect concentration, a midrange effect concentration, and an extreme effect concentration. Consensus-based SECs were derived because they estimate the central tendency of the published SQGs and, thus, reconcile the guidance values that have been derived using various approaches. Initially, consensus-based SECs for tPCBs were developed separately for freshwater sediments and for marine and estuarine sediments. Because the respective SECs were statistically similar, the underlying SQGs were subsequently merged and used to formulate more generally applicable SECs. The three consensus-based SECs were then evaluated for reliability using matching sediment chemistry and toxicity data from field studies, dose-response data from spiked-sediment toxicity tests, and SQGs derived from the equilibrium-partitioning approach. The results of this evaluation demonstrated that the consensus-based SECs can accurately predict both the presence and absence of toxicity in field-collected sediments. Importantly, the incidence of toxicity increases incrementally with increasing concentrations of tPCBs. Moreover, the consensus-based SECs are comparable to the chronic toxicity thresholds that have been estimated from dose-response data and equilibrium-partitioning models. Therefore, consensus-based SECs provide a unifying synthesis of existing SQGs, reflect causal rather than correlative effects, and accurately predict sediment toxicity in PCB-contaminated sediments.

Effects of Cytochrome P450 (CYP) 2C19 Genotypes on Steady-State Plasma Concentrations of Escitalopram and its Desmethyl Metabolite in Japanese Patients With Depression.

PubMed

Tsuchimine, Shoko; Ochi, Shinichiro; Tajiri, Misuzu; Suzuki, Yutaro; Sugawara, Norio; Inoue, Yoshimasa; Yasui-Furukori, Norio

2018-06-01

Plasma concentrations of the S-enantiomer of citalopram were different between extensive and poor CYP2C19 metabolizers in healthy subjects and depressed patients. However, most studies applied dose-corrected concentrations. Thus, we studied the effects of polymorphisms of the CYP2C19 gene on raw plasma drug concentrations in Japanese patients with depression. Subjects in this study consisted of 412 depressed patients receiving 5, 10, 15, or 20 mg of escitalopram once a day. Plasma concentrations of escitalopram and desmethylescitalopram were quantified using HPLC. CYP2C19 genotypes were identified using polymerase chain reaction methods. There were no differences in the steady-state plasma concentrations of escitalopram or desmethylescitalopram in each dose group (5, 10, 15, or 20 mg of escitalopram) among CYP2C19 genotype groups. However, 1-way analysis of variance showed significant effects of CYP2C19 genotypes on the dose-adjusted plasma concentration of escitalopram but not in the dose-adjusted plasma concentration of desmethylescitalopram. Analysis of covariance including age, sex, and body weight showed significant effects of CYP2C19 genotypes on the dose-adjusted plasma concentration of escitalopram and the ratio of desmethylescitalopram to escitalopram. These findings suggest that the CYP2C19 variants are associated with steady-state plasma concentrations of escitalopram to some extent but are not associated with desmethylescitalopram.

An investigation on the effects of air on electron energy in atmospheric pressure helium plasma jets

NASA Astrophysics Data System (ADS)

Liu, Yadi; Tan, Zhenyu; Chen, Xinxian; Li, Xiaotong; Zhang, Huimin; Pan, Jie; Wang, Xiaolong

2018-03-01

In this work, the effects of air on electron energy in the atmospheric pressure helium plasma jet produced by a needle-plane discharge system have been investigated by means of the numerical simulation based on a two-dimensional fluid model, and the air concentration dependences of the reactive species densities have also been calculated. In addition, the synergistic effects of the applied voltage and air concentration on electron energy have been explored. The present work gives the following significant results. For a fixed applied voltage, the averaged electron energy is basically a constant at air concentrations below about 0.5%, but it evidently decreases above the concentration of 0.5%. Furthermore, the averaged densities of four main reactive species O, O(1D), O2(1Δg), and N2(A3Σu+) increase with the increasing air concentration, but the increase becomes slow at air concentrations above 0.5%. The air concentration dependences of the averaged electron energy under different voltage amplitudes are similar, and for a given air concentration, the averaged electron energy increases with the increase in the voltage amplitude. For the four reactive species, the effects of the air concentration on their averaged densities are similar for a given voltage amplitude. In addition, the averaged densities of the four reactive species increase with increasing voltage amplitude for a fixed air concentration. The present work suggests that a combination of high voltage amplitude and the characteristic air concentration, 0.5% in the present discharge system, allows an expected electron energy and also generates abundant reactive species.

Detergent effects on enzyme activity and solubilization of lipid bilayer membranes.

PubMed

Womack, M D; Kendall, D A; MacDonald, R C

1983-09-07

Over 50 detergents were tested to establish which would be most effective in releasing proteins from membrane-bounded compartments without denaturing them. Various concentrations each of detergent were tested for two activities: (1) solubilization of egg phospholipid liposomes as measured by reduction of turbidity and (2) effect of detergent concentration on the activities of soluble, hydrolytic enzymes. Those detergents most effective in solubilizing 0.2% lipid and least detrimental to enzymes were five pure, synthetic compounds recently introduced: CHAPS, CHAPSO, Zwittergents 310 and 312, and octylglucoside. Industrial detergents were generally much inferior, insofar as they solubilized membranes inefficiently and/or inactivated certain hydrolytic enzymes readily. The five detergents were characterized by (a) an unusually high critical micelle concentration and (b) a preference for forming mixed micelles with lipids instead of forming pure micelles, as indicated by an ability to solubilize lipid at concentrations of detergent significantly below the critical micelle concentration. This characteristic permits solubilization of high concentrations of membrane below the critical micelle concentration of the detergent so that protein denaturation is minimized. A generally applicable guideline that emerged from this study is that detergents should be used at approximately their critical micelle concentration which should not be exceeded by the concentration of membrane. Similar considerations should apply to the use of detergents in purifying and reconstituting intrinsic membrane proteins.

A statistical model and national data set for partioning fish-tissue mercury concentration variation between spatiotemporal and sample characteristic effects

USGS Publications Warehouse

Wente, Stephen P.

2004-01-01

Many Federal, Tribal, State, and local agencies monitor mercury in fish-tissue samples to identify sites with elevated fish-tissue mercury (fish-mercury) concentrations, track changes in fish-mercury concentrations over time, and produce fish-consumption advisories. Interpretation of such monitoring data commonly is impeded by difficulties in separating the effects of sample characteristics (species, tissues sampled, and sizes of fish) from the effects of spatial and temporal trends on fish-mercury concentrations. Without such a separation, variation in fish-mercury concentrations due to differences in the characteristics of samples collected over time or across space can be misattributed to temporal or spatial trends; and/or actual trends in fish-mercury concentration can be misattributed to differences in sample characteristics. This report describes a statistical model and national data set (31,813 samples) for calibrating the aforementioned statistical model that can separate spatiotemporal and sample characteristic effects in fish-mercury concentration data. This model could be useful for evaluating spatial and temporal trends in fishmercury concentrations and developing fish-consumption advisories. The observed fish-mercury concentration data and model predictions can be accessed, displayed geospatially, and downloaded via the World Wide Web (http://emmma.usgs.gov). This report and the associated web site may assist in the interpretation of large amounts of data from widespread fishmercury monitoring efforts.

Joint toxicity of methamidophos and cadmium acting on Abelmoschus manihot.

PubMed

Wang, Xiao-Fei; Zhou, Qi-Xing

2005-01-01

Joint toxicity of methamidophos and cadmium (Cd) on the ornamental Abelmoschus manihot was firstly examined and compared with single-factor effects of the two pollutants using ecotoxicological indexes including the inhibitory rate of seed germination, root elongation and inhibitory concentration 50% (IC50). The results indicated that methamidophos and Cd had unobvious( p > 0.05) effects on seed germination of the ornamental. There were significant( p < 0.05) inhibitory effects of Cd on root elongation of the tested plant. When the concentration of added Cd was low( < 20 mg/L), significant antagonistic effects on root elongation were observed. And synergic effects were observed when Cd was added in high dose( > 20 mg/L). However, the analysis of joint effects indicated that there were antagonistic effects between Cd and methamidophos under all the treatments. At the high concentration of Cd, joint toxicity of methamidophos and Cd was more dependent on concentration of Cd.

Induction Speed Is Not a Determinant of Propofol Pharmacodynamics

PubMed Central

Doufas, Anthony G.; Bakhshandeh, Maryam; Bjorksten, Andrew R.; Shafer, Steven L.; Sessler, Daniel I.

2005-01-01

Summary We used individual pharmacodynamic modeling to demonstrate that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate of propofol. Background Evidence suggests that the rate at which they are infused may influence plasma-effect site equilibration of intravenous anesthetics. We used 5 different rates of propofol administration to test the hypothesis that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate. We concurrently evaluated the automated responsiveness monitor (ARM) against other sedation measures and the propofol effect site concentration. Methods With Human Studies Committee approval, 18 healthy volunteers received 5 consecutive target-controlled propofol infusions. During each infusion the effect site concentration was increased by a rate of 0.1, 0.3, 0.5, 0.7, or 0.9 μg·ml−1·min−1. Bispectral index and ARM were recorded at frequent intervals. The times of syringe drop and loss and recovery of responsiveness were noted. Pharmacokinetic and pharmacodynamic modeling was performed using NONMEM. Results Once the correct rate of plasma-effect site equilibration (ke0) was determined for each individual (ke0 = 0.17 min−1, time-to-peak effect = 2.7 min), the effect site concentrations associated with each clinical measure were not affected by the rate of rise of effect site propofol concentration. ARM correlated with all clinical measures of drug effect. Subjects invariably stopped responding to ARM at lower effect site propofol concentrations than those associated with loss of responsiveness. Conclusions Population-based pharmacokinetics, combined with real-time electroencephalographic measures of drug effect, may provide a means to individualize pharmacodynamic modeling during target-controlled drug delivery. ARM appears useful as an automated measure of sedation and may provide the basis for automated monitoring and titration of sedation for a propofol delivery system. PMID:15505446

What controls the low ice number concentration in the upper troposphere?

NASA Astrophysics Data System (ADS)

Zhou, Cheng; Penner, Joyce E.; Lin, Guangxing; Liu, Xiaohong; Wang, Minghuai

2016-10-01

Cirrus clouds in the tropical tropopause play a key role in regulating the moisture entering the stratosphere through their dehydrating effect. Low ice number concentrations ( < 200 L-1) and high supersaturations (150-160 %) have been observed in these clouds. Different mechanisms have been proposed to explain these low ice number concentrations, including the inhibition of homogeneous freezing by the deposition of water vapour onto pre-existing ice crystals, heterogeneous ice formation on glassy organic aerosol ice nuclei (IN), and limiting the formation of ice number from high-frequency gravity waves. In this study, we examined the effect from three different representations of updraft velocities, the effect from pre-existing ice crystals, the effect from different water vapour deposition coefficients (α = 0.1 or 1), and the effect of 0.1 % of the total secondary organic aerosol (SOA) particles acting as IN. Model-simulated ice crystal numbers are compared against an aircraft observational dataset.Including the effect from water vapour deposition on pre-existing ice particles can effectively reduce simulated in-cloud ice number concentrations for all model setups. A larger water vapour deposition coefficient (α = 1) can also efficiently reduce ice number concentrations at temperatures below 205 K, but less so at higher temperatures. SOA acting as IN is most effective at reducing ice number concentrations when the effective updraft velocities are moderate ( ˜ 0.05-0.2 m s-1). However, the effects of including SOA as IN and using (α = 1) are diminished when the effect from pre-existing ice is included.When a grid-resolved large-scale updraft velocity ( < 0.1 m s-1) is used, the ice nucleation parameterization with homogeneous freezing only or with both homogeneous freezing and heterogeneous nucleation is able to generate low ice number concentrations in good agreement with observations for temperatures below 205 K as long as the pre-existing ice effect is included. For the moderate updraft velocity ( ˜ 0.05-0.2 m s-1), simulated ice number concentrations in good agreement with observations at temperatures below 205 K can be achieved if effects from pre-existing ice, a larger water vapour deposition coefficient (α = 1), and SOA IN are all included. Using the sub-grid-scale turbulent kinetic energy (TKE)-based updraft velocity ( ˜ 0-2 m s-1) always overestimates the ice number concentrations at temperatures below 205 K but compares well with observations at temperatures above 205 K when the pre-existing ice effect is included.

What controls the low ice number concentration in the upper troposphere?

NASA Astrophysics Data System (ADS)

Zhou, C.; Penner, J. E.; Lin, G.; Liu, X.; Wang, M.

2015-12-01

Cirrus clouds in the tropical tropopause play a key role in regulating the moisture entering the stratosphere through their dehydrating effect. Low ice number concentrations (< 200 L-1) and high supersaturations (150-160 %) have been observed in these clouds. Different mechanisms have been proposed to explain these low ice number concentrations, including the inhibition of homogeneous freezing by the deposition of water vapour onto pre-existing ice crystals, heterogeneous ice formation on glassy organic aerosol ice nuclei (IN), and limiting the formation of ice number from high frequency gravity waves. In this study, we examined the effect from three different representations of updraft velocities, the effect from pre-existing ice crystals, the effect from different water vapour deposition coefficients (α = 0.1 or 1), and the effect of 0.1 % of the total secondary organic aerosol (SOA) particles acting as IN. Model simulated ice crystal numbers are compared against an aircraft observational dataset. Including the effect from water vapour deposition on pre-existing ice particles can effectively reduce simulated in-cloud ice number concentrations for all model set-ups. A larger water vapour deposition coefficient (α = 1) can also efficiently reduce ice number concentrations at temperatures below 205 K but less so at higher temperatures. SOA acting as IN are most effective at reducing ice number concentrations when the effective updraft velocities are moderate (∼ 0.05-0.2 m s-1). However, the effects of including SOA as IN and using (α = 1) are diminished when the effect from pre-existing ice is included. When a grid resolved large-scale updraft velocity (< 0.1 m s-1) is used, the ice nucleation parameterization with homogeneous freezing only or with both homogeneous freezing and heterogeneous nucleation is able to generate low ice number concentrations in good agreement with observations for temperatures below 205 K as long as the pre-existing ice effect is included. For the moderate updraft velocity (∼ 0.05-0.2 m s-1) simulated ice number concentrations in good agreement with observations at temperatures below 205 K can be achieved if effects from pre-existing ice, a larger water vapour deposition coefficient (α = 1) and SOA IN are all included. Using the sub-grid scale turbulent kinetic energy based updraft velocity (∼ 0-2 m s-1) always overestimates the ice number concentrations at temperatures below 205 K but compares well with observations at temperatures above 205 K when the pre-existing ice effect is included.

Milk protein concentration, estimated breeding value for fertility, and reproductive performance in lactating dairy cows.

PubMed

Morton, John M; Auldist, Martin J; Douglas, Meaghan L; Macmillan, Keith L

2017-07-01

Milk protein concentration in dairy cows has been positively associated with a range of measures of reproductive performance, and genetic factors affecting both milk protein concentration and reproductive performance may contribute to the observed phenotypic associations. It was of interest to assess whether these beneficial phenotypic associations are accounted for or interact with the effects of estimated breeding values for fertility. The effects of a multitrait estimated breeding value for fertility [the Australian breeding value for daughter fertility (ABV fertility)] on reproductive performance were also of interest. Interactions of milk protein concentration and ABV fertility with the interval from calving date to the start of the herd's seasonally concentrated breeding period were also assessed. A retrospective single cohort study was conducted using data collected from 74 Australian seasonally and split calving dairy herds. Associations between milk protein concentration, ABV fertility, and reproductive performance in Holstein cows were assessed using random effects logistic regression. Between 52,438 and 61,939 lactations were used for analyses of 4 reproductive performance measures. Milk protein concentration was strongly and positively associated with reproductive performance in dairy cows, and this effect was not accounted for by the effects of ABV fertility. Increases in ABV fertility had important additional beneficial effects on the probability of pregnancy by wk 6 and 21 of the herd's breeding period. For cows calved before the start of the breeding period, the effects of increases in both milk protein concentration and ABV fertility were beneficial regardless of their interval from calving to the start of the breeding period. These findings demonstrate the potential for increasing reproductive performance through identifying the causes of the association between milk protein concentration and reproductive performance and then devising management strategies to capitalize on them. Research should be conducted to understand the component of the relationship not captured by ABV fertility. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of low concentrations of benzalkonium chloride on acanthamoebal survival and its potential impact on empirical therapy of infectious keratitis.

PubMed

Tu, Elmer Y; Shoff, Megan E; Gao, Weihua; Joslin, Charlotte E

2013-05-01

The significant antiacanthamoebal effect of benzalkonium chloride, at or below concentrations used for preservation of common ophthalmic preparations, should be understood both when choosing empiric antibiotic therapy for infectious keratitis and when assessing the persistent rise in Acanthamoeba cases in the United States since 2003. To characterize the antiacanthamoebal efficacy of low concentrations of benzalkonium chloride (BAK) for drug preservation and therapeutic effect against Acanthamoeba. Experimental study with a review of the literature. Laboratory. A concentration of 10(4) trophozoites of 3 well-characterized clinical strains of Acanthamoeba were exposed at 0.5, 2.0, 3.5, 5.0, and 6.5 hours to BAK (0.001%, 0.002%, and 0.003%), moxifloxacin hydrochloride (0.5%), and moxifloxacin (0.5%) + BAK (0.001% and 0.003%) with hydrogen peroxide (3%) and amoeba saline controls. Amoeba survival was calculated using the most probable number method recorded as log kill values. The relationship of BAK concentration and exposure time as well as the relative effect of BAK and moxifloxacin on acanthamoebal survival were analyzed. Amoebicidal activity of BAK is both time dependent and concentration dependent in pooled and strain-stratified analyses (P < .001). Moxifloxacin demonstrated no significant independent inhibitory effect or additive effect to BAK efficacy on acanthamoebal survival. The profound antiacanthamoebal effect of BAK, 0.003%, was similar to that of hydrogen peroxide for certain strains. Low concentrations of BAK, previously demonstrated to concentrate and persist in ocular surface epithelium, exhibit significant antiacanthamoebal activity in vitro at or below concentrations found in commercially available ophthalmic anti-infectives. The unexplained persistence of the Acanthamoeba keratitis outbreak in the United States, clusters abroad, and clinical studies reporting resolution or modification of Acanthamoeba keratitis without specific antiacanthamoebal therapy suggests that other contributing factors should be considered, including changes in the formulations used for empirical therapy of presumed infectious keratitis occurring in the same period.

The effect of pumpkin (Cucurbita pepo L) seeds and L-arginine supplementation on serum lipid concentrations in atherogenic rats.

PubMed

Abuelgassim, Abuelgassim O; Al-showayman, Showayman I A

2012-01-01

The present study aimed to examine the effect of pumpkin (Cucurbita pepo L.) seeds supplementation on atherogenic diet-induced atherosclerosis. Rat were divided into two main groups , normal control and atherogenic control rats , each group composed of three subgroups one of them supplemented with 2% arginine in drinking water and the other supplemented with pumpkin seeds in diet at a concentration equivalent to 2% arginine. Supplementation continued for 37 days. Atherogenic rats supplemented with pumpkin seeds showed a significant decrease (p<0.001) in their serum concentrations of total cholesterol and LDL - C as they dropped from 4.89 mmol / L to 2.55 mmol /L and from 3.33 mmol / L to 0.70 mmol / L respectively. Serum concentrations of HDL-C were also significantly elevated in the same group. Although, atherogenic rats supplemented with 2% arginine showed significant increase in serum concentration of HDL-C, no significant changes were observed in their serum concentrations of total cholesterol and LDL-C. Our results showed that treatment of atherogenic rats with pumpkin seeds significantly decreased serum concentrations of TC and LDL-C. Our findings suggest that pumpkin seeds supplementation has a protective effect against atherogenic rats and this protective effect was not attributed to the high arginine concentrations in pumpkin seeds.

Improved product energy intensity benchmarking metrics for thermally concentrated food products.

PubMed

Walker, Michael E; Arnold, Craig S; Lettieri, David J; Hutchins, Margot J; Masanet, Eric

2014-10-21

Product energy intensity (PEI) metrics allow industry and policymakers to quantify manufacturing energy requirements on a product-output basis. However, complexities can arise for benchmarking of thermally concentrated products, particularly in the food processing industry, due to differences in outlet composition, feed material composition, and processing technology. This study analyzes tomato paste as a typical, high-volume concentrated product using a thermodynamics-based model. Results show that PEI for tomato pastes and purees varies from 1200 to 9700 kJ/kg over the range of 8%-40% outlet solids concentration for a 3-effect evaporator, and 980-7000 kJ/kg for a 5-effect evaporator. Further, the PEI for producing paste at 31% outlet solids concentration in a 3-effect evaporator varies from 13,000 kJ/kg at 3% feed solids concentration to 5900 kJ/kg at 6%; for a 5-effect evaporator, the variation is from 9200 kJ/kg at 3%, to 4300 kJ/kg at 6%. Methods to compare the PEI of different product concentrations on a standard basis are evaluated. This paper also presents methods to develop PEI benchmark values for multiple plants. These results focus on the case of a tomato paste processing facility, but can be extended to other products and industries that utilize thermal concentration.

Effect of feeding sweet-potato condensed distillers solubles on intake and urinary excretion of minerals in Japanese Black steers.

PubMed

Kamiya, Yuko; Kamiya, Misturu; Hattori, Ikuo; Hayashi, Yoshiro; Funaba, Masayuki; Matsui, Tohru

2017-01-01

Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet-potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH 3 ,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium-phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P. © 2016 Japanese Society of Animal Science.

A logical starting point for developing priorities for lizard and snake ecotoxicology: a review of available data.

PubMed

Campbell, Kym Rouse; Campbell, Todd S

2002-05-01

Reptiles, specifically lizards and snakes, usually are excluded from environmental contamination studies and ecological risk assessments. This brief summary of available lizard and snake environmental contaminant data is presented to assist in the development of priorities for lizard and snake ecotoxicology. Most contaminant studies were not conducted recently, list animals found dead or dying after pesticide application, report residue concentrations after pesticide exposure, compare contaminant concentrations in animals from different areas, compare residue concentrations found in different tissues and organs, or compare changes in concentrations over time. The biological significance of the contaminant concentrations is rarely studied. A few recent studies, especially those conducted on modern pesticides, link the contaminant effects with exposure concentrations. Nondestructive sampling techniques for determining organic and inorganic contaminant concentrations in lizards and snakes recently have been developed. Studies that relate exposure, concentration, and effects of all types of environmental contaminants on lizards and snakes are needed. Because most lizards eat insects, studies on the exposure, effects, and accumulation of insecticides in lizards, and their predators, should be a top priority. Because all snakes are upper-trophic-level carnivores, studies on the accumulation and effects of contaminants that are known to bioaccumulate or biomagnify up the food chain should be the top priority.

Performance of duckweed and effective microbes in reducing arsenic in paddy and paddy soil

NASA Astrophysics Data System (ADS)

Ng, C. A.; Wong, L. Y.; Lo, P. K.; Bashir, M. J. K.; Chin, S. J.; Tan, S. P.; Chong, C. Y.; Yong, L. K.

2017-04-01

In this study phytoremediation plant (duckweed) and effective microbes were used to investigate their effectiveness in reducing arsenic concentration in paddy soil and paddy grain. The results show that using duckweed alone is a better choice as it could decrease the arsenic concentration in paddy by 27.697 % and 8.268 % in paddy grain and paddy husk respectively. The study also found out that the concentration of arsenic in soil would affect the performance of duckweed and also delayed the reproduction rate of duckweed. Using the mixture of effective microbes and duckweed together to decrease arsenic in paddy was noticed having the least potential in reducing the arsenic concentration in paddy.

Quantifying Main Trends in Lysozyme Nucleation: The Effect of Precipitant Concentration and Impurities

NASA Technical Reports Server (NTRS)

Burke, Michael W.; Judge, Russell A.; Pusey, Marc L.; Rose, M. Franklin (Technical Monitor)

2000-01-01

Full factorial experiment design incorporating multi-linear regression analysis of the experimental data allows the main trends and effects to be quickly identified while using only a limited number of experiments. These techniques were used to identify the effect of precipitant concentration and the presence of an impurity, the physiological lysozyme dimer, on the nucleation rate and crystal dimensions of the tetragonal form of chicken egg white lysozyme. Increasing precipitant concentration was found to decrease crystal numbers, the magnitude of this effect also depending on the supersaturation. The presence of the dimer generally increased nucleation. The crystal axial ratio decreased with increasing precipitant concentration independent of impurity.

Effects of Aronia melanocarpa Fruit Juice on Isolated Rat Hepatocytes.

PubMed

Kondeva-Burdina, Magdalena; Valcheva-Kuzmanova, Stefka; Markova, Tsvetelina; Mitcheva, Mitka; Belcheva, Anna

2015-10-01

Aronia melanocarpa (Michx.) Elliot fruits are very rich in polyphenols - procyanidins, flavonoids, and phenolic acids. On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of A. melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by (i) metabolic bioactivation of carbon tetrachloride (CCl4), and (ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress. Isolated rat hepatocytes are a suitable model for hepatotoxicity studies. We determined the main parameters of the functional and metabolic status of rat hepatocytes: Cell viability (measured by trypan blue exclusion) and the levels of lactate dehydrogenase (LDH), reduced glutathione (GSH), and malondialdehyde (MDA). These parameters were used to investigate the protective effects of AMFJ in the two toxicity models. The effects of AMFJ were compared with those of silymarin. The cells were treated either with AMFJ or silymarin at increasing concentrations of 5 μg/ml, 10 μg/ml, 30 μg/ml, 50 μg/ml, and 100 μg/ml which were used for measuring of IC50. In both toxicity models - CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and more prominent in the t-BuOOH model, compared to those in the CCl4 model. The cytoprotective and antioxidant effects of AMFJ established in this study might be due to its polyphenolic ingredients, which could influence the cytochrome P450-mediated metabolism of the experimental hepatotoxic substances (CCl4 and t-BuOOH) and could act as free radical scavengers. The stronger effects of the highest AMFJ concentration in comparison with that of silymarin were possibly due to the combined presence of different polyphenols in the juice. On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of Aronia melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by i) metabolic bioactivation of carbon tetrachloride (CCl4), and ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress. In both toxicity models - CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and were more prominent in the t-BuOOH model, compared to those in the CCl4 model.

Effects of Aronia melanocarpa Fruit Juice on Isolated Rat Hepatocytes

PubMed Central

Kondeva-Burdina, Magdalena; Valcheva-Kuzmanova, Stefka; Markova, Tsvetelina; Mitcheva, Mitka; Belcheva, Anna

2015-01-01

Background: Aronia melanocarpa (Michx.) Elliot fruits are very rich in polyphenols – procyanidins, flavonoids, and phenolic acids. Objective: On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of A. melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by (i) metabolic bioactivation of carbon tetrachloride (CCl4), and (ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress. Materials and Methods: Isolated rat hepatocytes are a suitable model for hepatotoxicity studies. We determined the main parameters of the functional and metabolic status of rat hepatocytes: Cell viability (measured by trypan blue exclusion) and the levels of lactate dehydrogenase (LDH), reduced glutathione (GSH), and malondialdehyde (MDA). These parameters were used to investigate the protective effects of AMFJ in the two toxicity models. The effects of AMFJ were compared with those of silymarin. The cells were treated either with AMFJ or silymarin at increasing concentrations of 5 μg/ml, 10 μg/ml, 30 μg/ml, 50 μg/ml, and 100 μg/ml which were used for measuring of IC50. Results: In both toxicity models – CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and more prominent in the t-BuOOH model, compared to those in the CCl4 model. Conclusion: The cytoprotective and antioxidant effects of AMFJ established in this study might be due to its polyphenolic ingredients, which could influence the cytochrome P450-mediated metabolism of the experimental hepatotoxic substances (CCl4 and t-BuOOH) and could act as free radical scavengers. The stronger effects of the highest AMFJ concentration in comparison with that of silymarin were possibly due to the combined presence of different polyphenols in the juice. SUMMARY On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of Aronia melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by i) metabolic bioactivation of carbon tetrachloride (CCl4), and ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress. In both toxicity models – CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and were more prominent in the t-BuOOH model, compared to those in the CCl4 model. PMID:27013800

Changes in relative and absolute concentrations of plasma phospholipid fatty acids observed in a randomized trial of Omega-3 fatty acids supplementation in Uganda.

PubMed

Song, Xiaoling; Diep, Pho; Schenk, Jeannette M; Casper, Corey; Orem, Jackson; Makhoul, Zeina; Lampe, Johanna W; Neuhouser, Marian L

2016-11-01

Expressing circulating phospholipid fatty acids (PLFAs) in relative concentrations has some limitations: the total of all fatty acids are summed to 100%; therefore, the values of individual fatty acid are not independent. In this study we examined if both relative and absolute metrics could effectively measure changes in circulating PLFA concentrations in an intervention trial. 66 HIV and HHV8 infected patients in Uganda were randomized to take 3g/d of either long-chain omega-3 fatty acids (1856mg EPA and 1232mg DHA) or high-oleic safflower oil in a 12-week double-blind trial. Plasma samples were collected at baseline and end of trial. Relative weight percentage and absolute concentrations of 41 plasma PLFAs were measured using gas chromatography. Total cholesterol was also measured. Intervention-effect changes in concentrations were calculated as differences between end of 12-week trial and baseline. Pearson correlations of relative and absolute concentration changes in individual PLFAs were high (>0.6) for 37 of the 41 PLFAs analyzed. In the intervention arm, 17 PLFAs changed significantly in relative concentration and 16 in absolute concentration, 15 of which were identical. Absolute concentration of total PLFAs decreased 95.1mg/L (95% CI: 26.0, 164.2; P=0.0085), but total cholesterol did not change significantly in the intervention arm. No significant change was observed in any of the measurements in the placebo arm. Both relative weight percentage and absolute concentrations could effectively measure changes in plasma PLFA concentrations. EPA and DHA supplementation changes the concentrations of multiple plasma PLFAs besides EPA and DHA.Both relative weight percentage and absolute concentrations could effectively measure changes in plasma phospholipid fatty acid (PLFA) concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effectiveness of sheltering in buildings and vehicles for plutonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, R.J.

1990-07-30

The purpose of this paper is to collect and present current knowledge relevant to the protection offered by sheltering against exposure to plutonium particles released to the atmosphere during accidents. For those many contaminants for which effects are linear with the airborne concentration, it is convenient to define a Dose Reduction Factor (DRF). In the past, the DRF has been defined as the ratio of the radiological dose that may be incurred within the shelter to that in the outdoors. As such, it includes the dose through shine from plumes aloft and from material deposited on the surface. For thismore » paper, which is concerned only with the inhalation pathway, the DRF is the ratio of the time-integrated concentration inside the shelter to that outdoors. It is important to note that the range over which effects are linear with concentration may be limited for many contaminants. Examples are when concentrations produce effects that are irreversible, or when concentrations are below effects threshold levels. 71 refs., 4 figs., 8 tabs.« less

Biotransference and biomagnification of selenium copper, cadmium, zinc, arsenic and lead in a temperate seagrass ecosystem from Lake Macquarie Estuary, NSW, Australia.

PubMed

Barwick, M; Maher, W

2003-10-01

In this study the biotransference of selenium copper, cadmium, zinc, arsenic and lead was measured in a contaminated seagrass ecosystem in Lake Macquarie, NSW, Australia, to determine if biomagnification of these trace metals is occurring and if they reach concentrations that pose a threat to the resident organisms or human consumers. Selenium was found to biomagnify, exceeding maximum permitted concentrations for human consumption within carnivorous fish tissue, the highest trophic level examined. Selenium concentrations measured within carnivorous fish were also above those shown to elicit sub-lethal effects in freshwater fish. As comparisons are made to selenium concentrations known to effect freshwater fish, inferences must be made with caution. There was no evidence of copper, cadmium, zinc or lead biomagnification within the food web examined. Copper, cadmium, zinc and lead concentrations were below concentrations shown to elicit adverse responses in biota. Copper concentrations within crustaceans M. bennettae and P. palagicus were found to exceed maximum permitted concentrations for human consumption. It is likely that copper concentrations within these species were accumulated due to the essential nature of this trace metal for many species of molluscs and crustaceans. Arsenic showed some evidence of biomagnification. Total arsenic concentrations are similar to those found in other uncontaminated marine ecosystems, thus arsenic concentrations are unlikely to cause adverse effects to aquatic organisms. Inorganic arsenic concentrations are below maximum permitted concentrations for human consumption.

Effects of temperature and antibiotics on persistence of antibiotic-resistant bacteria and antibiotic resistance genes in poultry litter

USDA-ARS?s Scientific Manuscript database

The effect of low, residual concentrations of antibiotics in manure and other environmental matrices is not well understood. It has been hypothesized that antibiotic concentrations below clinical MIC (minimal inhibitory concentrations) are still capable of selecting for resistance. The objective of ...

Occurrence of and trends in selected sediment-associated contaminants in Caddo Lake, East Texas, 1940-2002

USGS Publications Warehouse

Wilson, Jennifer T.

2003-01-01

Bottom-sediment cores were collected from four sites in Caddo Lake in East Texas during May 2002 for analyses of radionuclides (for age dating), organochlorine pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and major and trace elements, and to describe the occurrence and trends of these sediment-associated contaminants. The Goose Prairie Creek and Harrison Bayou sites receive drainage from an area that includes parts of the now-closed Longhorn Army Ammunitions Plant. The mid-lake site is relatively close to dense oil and gas operations in the lake. The Carter Lake site receives minimal discharge from developed areas. Sediment age (deposition) dates represented in the cores ranged from 1940 to 2002. The only organochlorine compounds detected in all core samples were the DDT degradation products DDE or DDD, and PCB Aroclors 1242, 1254, and 1260 were detected only at the Goose Prairie Creek site. One or more of the DDE concentrations at all sites exceeded a consensus-based threshold effect concentration (on benthic biota), but none exceeded a consensus-based probable effect concentration. The Goose Prairie Creek site had significant downward trends in concentrations of organochlorine compounds, except for no trend in DDE concentrations. The Ammunitions Plant is a possible historical source of the few organochlorine compounds detected at the Goose Prairie Creek and Harrison Bayou sites. PAH concentrations at all sites were below respective threshold effect concentrations. Highest PAH concentrations at all four sites were of C2- alkylated naphthalenes. Nearly all statistically significant PAH trends in the cores were downward. On the basis of PAH source-indicator ratios, the majority of PAH compounds appear to have originated from uncombusted sources such as leaks or spills from oil and gas operations or vehicles (automobiles, boats, aircraft) in the Caddo Lake area. Concentrations of several of the eight trace elements with threshold effect concentrations and probable effect concentrations (among 26 analyzed) were above the respective threshold effect concentrations, but all, except one lead concentration at the Goose Prairie Creek site (deposited about 1961), were below respective probable effect concentrations. Among trace element concentrations at the four sites, lead and mercury were consistently relatively high at the Goose Prairie Creek site. Again the Ammunitions Plant, because of its proximity and history of industrial activities, is the suspected primary source. Statistically significant trends in trace element concentrations were mixed, but more were downward than upward. Computations to indicate the dominant source (atmospheric fallout or drainage area) of mercury to the Caddo Lake sediment core sites (except Carter Lake) indicate that about one-third of the mercury at the Goose Prairie Creek site might result from drainage area sources. No drainage area sources were indicated for the Harrison Bayou and mid-lake sites. Arsenic, cadmium, and zinc concentrations were highest at the Carter Lake site. No relation between the relatively higher trace element concentrations and any potential source of contamination in the Carter Lake drainage area (for example, oil and gas operations, a road, a boat ramp) is indicated.

Vasoconstrictors in local anesthesia for dentistry.

PubMed Central

Sisk, A. L.

1992-01-01

Addition of a vasoconstrictor to a local anesthetic may have several beneficial effects: a decrease in the peak plasma concentration of the local anesthetic agent, increase in the duration and the quality of anesthesia, reduction of the minimum concentration of anesthetic needed for nerve block, and decrease of blood loss during surgical procedures. The addition of a vasoconstrictor to a local anesthetic may also have detrimental effects. A review of the literature indicates that vasoconstrictor concentrations in local anesthetics marketed for dental use in the United States are not always optimal to achieve the purposes for which they are added. In most cases, a reduced concentration of vasoconstrictor could achieve the same goal as the marketed higher concentration, with less side-effect liability. PMID:8250339

Probe diffusion of labeled polymers inside polyacrylic acid solutions: A polyelectrolyte effect

NASA Astrophysics Data System (ADS)

Mishra, Banani; Mithra, K.; Khandai, Santripti; Jena, Sidhartha S.

2018-05-01

Probe diffusion of fluorescently labeled Dextran 40 inside polyelectrolyte solution of polyacrylic acid (PAA) was investigated using Fluorescence Recovery After Photobleaching technique. The crowding and interaction effects on probe diffusion were controlled by tuning background polymer and added external electrolyte concentration. For all the salt concentration, an overall decrease in diffusion coefficient is observed with rise in polymer concentration. The diffusion coefficient decreases with decrease in salt concentration whereas the solution viscosity increases, indicating a competition between viscous drag and electrostatic interaction. A large positive deviation from the ideal Stokes-Einstein relation is observed for high polymer and low salt concentration, which reduces markedly with addition of salt confirming polyelectrolyte effects, plays a major role in deciding the probe diffusion.

Quantifying Main Trends in Lysozyme Nucleation: The Effects of Precipitant Concentration, Supersaturation and Impurities

NASA Technical Reports Server (NTRS)

Burke, Michael W.; Leardi, Riccardo; Judge, Russell A.; Pusey, Marc L.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

Full factorial experimental design incorporating multi-linear regression analysis of the experimental data allows quick identification of main trends and effects using a limited number of experiments. In this study these techniques were employed to identify the effect of precipitant concentration, supersaturation, and the presence of an impurity, the physiological lysozyme dimer, on the nucleation rate and crystal dimensions of the tetragonal forin of chicken egg white lysozyme. Decreasing precipitant concentration, increasing supers aturation, and increasing impurity, were found to increase crystal numbers. The crystal axial ratio decreased with increasing precipitant concentration, independent of impurity.

Chronic effects of environmentally-relevant concentrations of lead in Pelophylax nigromaculata tadpoles: Threshold dose and adverse effects.

PubMed

Huang, Min-Yi; Duan, Ren-Yan; Ji, Xiang

2014-06-01

Lead (Pb) is a common heavy metal in the natural environment, but its concentration has been increasing alongside widespread industrial and agricultural development in China. The dark-spotted frog Pelophylax (formerly Rana) nigromaculata (Anura: Ranidae) is distributed across East Asia and inhabits anthropogenic habitats such as farmland. Here, P. nigromaculata tadpoles (Gosner stage 19-46) were exposed to Pb at different concentrations (0, 40, 80, 160, 320, 640 and 1280µg/L) and Pb-induced survival, metamorphosis time, development, malformations, mobility and gonad structure were monitored. The results showed that above the threshold concentration of Pb, adverse effects were obvious. As the concentration of Pb increased, the adverse effects on different traits followed different patterns: the effects on hindlimb length, survival rate, metamorphosis rate, total malformation rate, swimming speed and jumping speed largely exhibited a linear pattern; the effects on snout-vent length, body mass and forelimb length largely exhibited a bimodal pattern. Sex ratio and gonadal histology were not affected by Pb, suggesting that Pb is not strongly estrogenic in P. nigromaculata. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of single-walled carbon nanotubes on primary immune cells in vitro

NASA Astrophysics Data System (ADS)

Zhang, Jin-chao; Ji, Xiao-yu; Liu, Cui-lian; Shen, Shi-gang; Wang, Shu-xiang; Sun, Jing

2008-06-01

Carbon nanotubes (CNTs) are emerging as innovative tools in nanobiotechnology. However, their toxic effects on environment and health have become an issue of great concern. The effect of single-walled carbon nanotubes (SWCNTs) on primary immune cells in vitro was studied in this paper. The results indicated that SWCNTs (25 and 50 μg/mL) could promote the proliferation of spleen cells. However, they had no significant effect on the proliferation of spleen cells at concentrations of 1 and 10 μg/mL. They also had no effect on T-lymphocyte proliferation stimulated by concanavalinA (ConA) at lower concentrations. Moreover, they turned to inhibit T-lymphocyte proliferation at higher concentrations. It was found that SWCNTs inhibited the B-lymphocyte proliferation stimulated by lipopolysaccharides (LPS) at concentrations of 1, 10, 25 and 50 μg/mL. What is more, they significantly decreased the Natural Killer (NK) cell activity compared with the control group at all tested concentrations. The results suggest that SWCNTs have possibly negative effects on immune cells in vitro.

Effects of EDTA and low molecular weight organic acids on soil solution properties of a heavy metal polluted soil.

PubMed

Wu, L H; Luo, Y M; Christie, P; Wong, M H

2003-02-01

A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the soil solution in the rhizosphere of Brassica juncea grown in a paddy soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the soil solution pH. EDTA addition significantly increased the TOC concentrations in the soil solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the soil solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the soil solution followed the sequence: EDTA > citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA > MA > CA approximately OA for Zn; and EDTA > MA > CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.

[The effect of pemolin on the mitotic activity of Vicia faba L (author's transl)].

PubMed

Brabec, F; Röper, W

1976-02-01

The effect of diverse concentrations of 5-phenyl-2-imino-4-oxazolidone (PIO, pemolin, Tradon) on the mitotic activity in lateral roots of Vicia faba L. was studied by aerated and non-aerated hydrocultivation with and without mineral nutrition, respectively. With optimal conditions (aerated nutrient solution) weak PIO-concentrations, most significantly 10(-6) g/ml, effected a marked increase of the mitotic index. Contrarily, strong PIO-concentrations (10(-4) and 3 X 10(-4) g/ml = saturated solution) significantly decreased the mitotic index though simultaneously preserving the mitotic activity in long-term experiments, when on account of nutrient deficiency it had already collapsed in weak PIO-concentrations and the controls. The activating effect of weak PIO-concentrations compared with the controls is more significant in stress situations (nutrient deficiency, O2-deficiency) than under optimal conditions. Furthermore a slight acceleration of mid-mitotic phases (metaphase--anaphase) recognized by a marked decrease in percentage of these phases, can be stated with weak PIO-concentrations, again particularly so with 10(-6) g/ml. In total, dependent on concentration, pemolin presumably may either activate or suppress cell metabolism and particularly the mitotic cycle. The exact site of action of the substance is still unknown.

A content analysis of tweets about high-potency marijuana.

PubMed

Cavazos-Rehg, Patricia A; Sowles, Shaina J; Krauss, Melissa J; Agbonavbare, Vivian; Grucza, Richard; Bierut, Laura

2016-09-01

"Dabbing" involves heating extremely concentrated forms of marijuana to high temperatures and inhaling the resulting vapor. We studied themes describing the consequences of using highly concentrated marijuana by examining the dabbing-related content on Twitter. Tweets containing dabbing-related keywords were collected from 1/1-1/31/2015 (n=206,854). A random sample of 5000 tweets was coded for content according to pre-determined categories about dabbing-related behaviors and effects experienced using a crowdsourcing service. An examination of tweets from the full sample about respiratory effects and passing out was then conducted by selecting tweets with relevant keywords. Among the 5000 randomly sampled tweets, 3540 (71%) were related to dabbing marijuana concentrates. The most common themes included mentioning current use of concentrates (n=849; 24%), the intense high and/or extreme effects from dabbing (n=763; 22%) and excessive/heavy dabbing (n=517; 15%). Extreme effects included both physiological (n=124/333; 37%) and psychological effects (n=55/333; 17%). The most common physiologic effects, passing out (n=46/333; 14%) and respiratory effects (n=30/333; 9%), were then further studied in the full sample of tweets. Coughing was the most common respiratory effect mentioned (n=807/1179; 68%), and tweeters commonly expressed dabbing with intentions to pass out (416/915; 45%). This study adds to the limited understanding of marijuana concentrates and highlights self-reported physical and psychological effects from this type of marijuana use. Future research should further examine these effects and the potential severity of health consequences associated with concentrates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effect of nicotine on reproduction and attachment of human gingival fibroblasts in vitro.

PubMed

Peacock, M E; Sutherland, D E; Schuster, G S; Brennan, W A; O'Neal, R B; Strong, S L; Van Dyke, T E

1993-07-01

The ability of fibroblasts to reproduce and attach to teeth is of paramount importance in re-establishing the lost connective tissue attachment after periodontal therapy. This study examined the effect of nicotine, a major component of the particulate phase of tobacco smoke, on human gingival fibroblast (HGF) reproduction and attachment to tissue culture surfaces. Pooled HGF cultures made from explants of gingival biopsies were utilized between passages 5 and 10 and plated in 96-well plates at 1.0 x 10(4) cells per well. Cell numbers were determined using 3-(4,5-dimethylthiazol-2-y)-2,5-diphenyl tetrazolium bromide (MTT), which is a reflection of mitochondrial dehydrogenase activity. The concentrations of nicotine used were 0.025, 0.05, 0.1, 0.2, and 0.4 microM, the average serum concentration for a smoker being approximately 0.1 microM. The effect of continuous nicotine exposure on HGF reproduction was determined by incubating cell cultures and media containing nicotine for up to 48 hours. Residual toxicity was determined by preincubating cells with nicotine for 1 or 6 hours. HGF suspensions and increasing concentrations of nicotine were added together to determine the effect on attachment. Results showed an enhanced effect of nicotine on HGF attachment, with increasing numbers of cells attaching with increasing nicotine concentrations, compared to the control. Low concentrations of nicotine had a stimulatory effect on cell replication, while higher concentrations of nicotine appear to have no significant effect on HGF reproduction. The responses of cells to some concentrations of nicotine may persist after its removal.

The effects of commonly used intravitreal steroids on proliferation index of ciliary body-derived mesenchymal stem cells: an in vitro study.

PubMed

Demir, M Necati; Acar, Ugur; Sobaci, Gungor; Pınarlı, Ferda Alpaslan; Erginturk Acar, Damla; Beyazyıldız, Emrullah; Yesilyurt, Ahmet; Delibasi, Tuncay

2016-03-01

To investigate the effects of commonly used intravitreal steroids on survival and proliferation (namely, proliferation index) of ciliary body-derived mesenchymal stem cells (CB-MSC). CB-MSCs were isolated from newborn rats' eye, and they were expanded in the medium. Commonly used intravitreal steroids such as dexamethasone (Dex) and triamcinolone acetonide (TA) were added into the medium at commonly used concentration in clinical practice (0.1 mg/mL) and at lower concentration (0.01 mg/mL). Proliferation indexes of CB-MSCs were analyzed with the xCELLigence system at nine consecutive times (at 3rd, 6th, 21th, 30th, 45th, 60th, 75th, 90th and 100th h). Both TA and Dex at both 0.01 mg/mL and 0.1 mg/mL concentrations had negative effect on proliferation indexes of CB-MSC. Although negative effect of TA on proliferation index of CB-MSC at both concentrations was not statistically significant, statistically significant negative effect of Dex at 0.01 mg/mL concentration started 60th h (p = 0.017) and 0.1 mg/mL concentration started 30th h (p = 0.014). Even therapeutic doses of intravitreal corticosteroid agents might have negative effects on limited numbers of stem cells. Especially, Dex caused statistically significant toxic effects on CB-MSCs even at lower concentrations of those used clinically. These novel findings deserve further in vivo investigations.

Cadmium toxicity at low concentration on rabbit spermatozoa motility, morphology and membrane integrity in vitro.

PubMed

Roychoudhury, Shubhadeep; Massanyi, Peter; Bulla, Jozef; Choudhury, Manabendra Dutta; Lukac, Norbert; Filipejova, Terezia; Trandzik, Jozef; Toman, Robert; Almasiova, Viera

2010-09-01

In this study the effect of cadmium on various parameters of spermatozoa motility, morphology as well as on the spermatozoa membrane integrity in rabbits was analyzed in vitro, experimental concentrations ranging from 0.62 to 0.98 micro g CdCl(2)/mL. Pooled rabbit (n = 5) semen was cultured in vitro with cadmium and subsequently diluted to various experimental concentrations apart from control which received no cadmium exposure. Using computer assisted semen analysis method (CASA) we detected decrease of total motility with in the higher concentration range at Time 0. However, with increasing time (after 1 and 2 h of culture), cadmium exerted deleterious effect leading to significant motility reduction in comparison to control. A similar trend was exhibited in case of progressive motility, too. Most of the spermatozoa distance and velocity parameters detected no significant change in comparison to control at the beginning of culture (Time 0), although the toxic effect became significant (P < 0.05) with the passage of culture time (Times 1 and 2 h) in all concentrations. Analysis of spermatozoa morphology detected significant (P < 0.05) alterations at higher concentrations. At higher concentrations acrosomal changes, head without flagellum/separated flagellum, broken flagellum and other abnormalities were significantly higher (P < 0.05), while knob-twisted flagellum and small heads differed significantly (P < 0.05) in comparison to control at all concentrations. In regards to flagellum torso, flagellum ball and retention of cytoplasmic drop statistically higher values (P < 0.05) were noted at the maxium experimental concentration only. Annexin analysis for detection of spermatozoa with disordered membranes revealed higher occurrence of positive spermatozoa in cadmium exposed groups. Annexin-positive reactions suggested alterations in anterior part of head (acrosome) and in flagellum (mitochondrial segment) of spermatozoa. This paper underlines that cadmium is highly toxic for rabbit spermatozoa, as visualized by the toxic effects on parameters of spermatozoa motility, morphology and membrane integrity. The toxic effect is more drastic at higher concentrations. This study also indicates that cadmium requires a minimum one hour incubation time to exert its deletorious effects on various parameters of spermatozoa, particularly at low concentrations.

Antibacterial effects and dissolution behavior of six bioactive glasses.

PubMed

Zhang, Di; Leppäranta, Outi; Munukka, Eveliina; Ylänen, Heimo; Viljanen, Matti K; Eerola, Erkki; Hupa, Mikko; Hupa, Leena

2010-05-01

Dissolution behavior of six bioactive glasses was correlated with the antibacterial effects of the same glasses against sixteen clinically important bacterial species. Powdered glasses (<45 microm) were immersed in simulated body fluid (SBF) for 48 h. The pH in the solution inside the glass powder was measured in situ with a microelectrode. After 2, 4, 27, and 48 h, the pH and concentration of ions after removing the particles and mixing the SBF were measured with a normal glass pH electrode and ICP-OES. The bacteria were cultured in broth with the glass powder for up to 4 days, after which the viability of the bacteria was determined. The antibacterial effect of the glasses increased with increasing pH and concentration of alkali ions and thus with increased dissolution tendency of the glasses, but it also depended on the bacterium type. The changes in the concentrations of Si, Ca, Mg, P, and B ions in SBF did not show statistically significant influence on the antibacterial property. Bioactive glasses showed strong antibacterial effects for a wide selection of aerobic bacteria at a high sample concentration (100 mg/mL). The antibacterial effects increased with glass concentration and a concentration of 50 mg/mL (SA/V 185 cm(-1)) was required to generate the bactericidal effects. Understanding the dissolution mechanisms of bioactive glasses is essential when assessing their antibacterial effects. Copyright 2009 Wiley Periodicals, Inc.

Aquatic concentrations of chemical analytes compared to ...

EPA Pesticide Factsheets

We describe screening level estimates of potential aquatic toxicity posed by 227 chemical analytes that were measured in 25 ambient water samples collected as part of a joint USGS/USEPA drinking water plant study. Measured concentrations were compared to biological effect concentration (EC) estimates, including USEPA aquatic life criteria, effective plasma concentrations of pharmaceuticals, published toxicity data summarized in the USEPA ECOTOX database, and chemical structure-based predictions. Potential dietary exposures were estimated using a generic 3-tiered food web accumulation scenario. For many analytes, few or no measured effect data were found, and for some analytes, reporting limits exceeded EC estimates, limiting the scope of conclusions. Results suggest occasional occurrence above ECs for copper, aluminum, strontium, lead, uranium, and nitrate. Sparse effect data for manganese, antimony, and vanadium suggest that these analytes may occur above ECs, but additional effect data would be desirable to corroborate EC estimates. These conclusions were not affected by bioaccumulation estimates. No organic analyte concentrations were found to exceed EC estimates, but ten analytes had concentrations in excess of 1/10th of their respective EC: triclocarban, norverapamil, progesterone, atrazine, metolachlor, triclosan, para-nonylphenol, ibuprofen, venlafaxine, and amitriptyline, suggesting more detailed characterization of these analytes. Purpose: to provide sc

Aquatic concentrations of chemical analytes compared to ecotoxicity estimates

USGS Publications Warehouse

Kostich, Mitchell S.; Flick, Robert W.; Angela L. Batt,; Mash, Heath E.; Boone, J. Scott; Furlong, Edward T.; Kolpin, Dana W.; Glassmeyer, Susan T.

2017-01-01

We describe screening level estimates of potential aquatic toxicity posed by 227 chemical analytes that were measured in 25 ambient water samples collected as part of a joint USGS/USEPA drinking water plant study. Measured concentrations were compared to biological effect concentration (EC) estimates, including USEPA aquatic life criteria, effective plasma concentrations of pharmaceuticals, published toxicity data summarized in the USEPA ECOTOX database, and chemical structure-based predictions. Potential dietary exposures were estimated using a generic 3-tiered food web accumulation scenario. For many analytes, few or no measured effect data were found, and for some analytes, reporting limits exceeded EC estimates, limiting the scope of conclusions. Results suggest occasional occurrence above ECs for copper, aluminum, strontium, lead, uranium, and nitrate. Sparse effect data for manganese, antimony, and vanadium suggest that these analytes may occur above ECs, but additional effect data would be desirable to corroborate EC estimates. These conclusions were not affected by bioaccumulation estimates. No organic analyte concentrations were found to exceed EC estimates, but ten analytes had concentrations in excess of 1/10th of their respective EC: triclocarban, norverapamil, progesterone, atrazine, metolachlor, triclosan, para-nonylphenol, ibuprofen, venlafaxine, and amitriptyline, suggesting more detailed characterization of these analytes.

Effects of boron on structure and antioxidative activities of spleen in rats.

PubMed

Hu, Qianqian; Li, Shenghe; Qiao, Enmei; Tang, Zhongtao; Jin, Erhui; Jin, Guangming; Gu, Youfang

2014-04-01

In order to determine the relationship between boron and development of the spleen, especially in the promoting biological effects, we examined the effects of different levels of boron on weight, organ index, microstructure, and antioxidative activities of the spleen in rats. Sprague-Dawley (SD) rats were selected and treated with different concentrations of boron, and then, the organs were resected and weighed. One half of the tissue was fixed and embedded in paraffin to observe tissue structure changes. The other half of the tissue was homogenated for determining the antioxidant activities. The results showed that 40 mg/L of boron could increase weight, organ indexes, and antioxidant capacity of spleens and improve the spleen tissue structure, while the boron concentration above 80 mg/L could decrease weight, organ indexes, and antioxidant capacity of spleens and damage the spleen tissue structure. The higher the concentration, the more serious the damage was. Especially at the concentration of 640 mg/L, it could significantly inhibit the development of the spleen and even exhibit toxic effect. Hence, low boron concentration played a protective role in the development of the spleen, while high boron concentration could damage the organs and even produce toxic effect.

The effects of vinblastine on endothelial cells.

PubMed

Gallagher, H; Carroll, W M; Dowd, M; Rochev, Y

2008-01-01

The development of drug-eluting stents to combat the problem of in-stent restenosis has revolutionized interventional cardiology. However, concerns have emerged about the risk of late angiographic stent thromboses associated with drug-eluting stents. It has been shown that noncytotoxic concentrations of paclitaxel exert an antiangiogenic effect, suggesting that paclitaxel and similar agents may inhibit key cellular functions in a threshold-independent manner. In this study, the effect of vinblastine, an antimitotic drug, on endothelial cells is analyzed. It is investigated whether noncytotoxic concentrations of the drug could exert an antirestenotic effect. The change in levels of cell proliferation, activity, and viability in human umbilical vein endothelial cells was measured at a range of concentrations and over a number of time points. Also, the level of apoptotic activity in response to vinblastine was analyzed. This study shows that the concentration of vinblastine most appropriate in restenosis treatment would be between 0.1 and 1 nM. At this concentration, vinblastine exerts a distinct biological effect without causing an increase in apoptotic activity. These results emphasize the importance of finding an appropriate concentration window in order to minimize the risk of delayed endothelialization and thrombosis.

Aquatic concentrations of chemical analytes compared to ecotoxicity estimates.

PubMed

Kostich, Mitchell S; Flick, Robert W; Batt, Angela L; Mash, Heath E; Boone, J Scott; Furlong, Edward T; Kolpin, Dana W; Glassmeyer, Susan T

2017-02-01

We describe screening level estimates of potential aquatic toxicity posed by 227 chemical analytes that were measured in 25 ambient water samples collected as part of a joint USGS/USEPA drinking water plant study. Measured concentrations were compared to biological effect concentration (EC) estimates, including USEPA aquatic life criteria, effective plasma concentrations of pharmaceuticals, published toxicity data summarized in the USEPA ECOTOX database, and chemical structure-based predictions. Potential dietary exposures were estimated using a generic 3-tiered food web accumulation scenario. For many analytes, few or no measured effect data were found, and for some analytes, reporting limits exceeded EC estimates, limiting the scope of conclusions. Results suggest occasional occurrence above ECs for copper, aluminum, strontium, lead, uranium, and nitrate. Sparse effect data for manganese, antimony, and vanadium suggest that these analytes may occur above ECs, but additional effect data would be desirable to corroborate EC estimates. These conclusions were not affected by bioaccumulation estimates. No organic analyte concentrations were found to exceed EC estimates, but ten analytes had concentrations in excess of 1/10th of their respective EC: triclocarban, norverapamil, progesterone, atrazine, metolachlor, triclosan, para-nonylphenol, ibuprofen, venlafaxine, and amitriptyline, suggesting more detailed characterization of these analytes. Published by Elsevier B.V.

Antioxidant effects of 14 Chinese traditional medicinal herbs against human low-density lipoprotein oxidation.

PubMed

Lin, Hsin-Hung; Charles, Albert Linton; Hsieh, Chang-Wei; Lee, Ya-Chi; Ciou, Jhih-Ying

2015-01-01

The relationship between the antioxidant activities and inhibitory effect of 14 Chinese medicinal herbs against oxidized low-density lipoprotein (LDL) formation was evaluated. Prolongation of the lag phase of LDL oxidation depended on the concentration of the herbs. The concentration of each herb that was able to prolong the lag time by about two-fold was calculated and expressed as doubling-time concentration. The lower the doubling-time concentration, the stronger the inhibitory effect exhibited toward LDL oxidation. Among them, Chrysanthemi Flos (Chrysanthemum morifolium ramat; gān jú huā), Crataegi Fructus (Crataegus pinnatifida Bge. var. major N.E.Br.; shān zhā), and Roselle (Hibiscus sabdariffa Linn.; luò shén) showed significant inhibitory effects. Correlation coefficients between doubling-time concentration and radical-scavenging activities were high; the total phenolic content was also high. In conclusion, phenolic compounds contributed not only to antioxidant activities, but also to the inhibitory effect against LDL oxidation. Chrysanthemi Flos, Crataegi Fructus, and H. sabdariffa, with lower doubling-time concentrations, could be potent phytochemical agents to reduce LDL oxidation and prevent the progression of atherosclerosis.

Cost minimisation analysis of provision of oxygen at home: are the Drug Tariff guidelines cost effective?

PubMed Central

Heaney, Liam G; McAllister, Denise; MacMahon, Joseph

1999-01-01

Objectives To determine the level of oxygen cylinder use at which it becomes more cost effective to provide oxygen by concentrator at home in Northern Ireland, and to examine potential cost savings if cylinder use above this level had been replaced by concentrator in 1996. Design Cost minimisation analysis. Setting Area health boards in Northern Ireland. Main outcome measures Cost effective cut off point for switch to provision of oxygen from cylinder to concentrator. Potential maximum and minimum savings in Northern Ireland (sensitivity analysis) owing to switch to more cost effective strategy on the basis of provision of cylinders in 1996. Results In Northern Ireland it is currently cost effective to provide oxygen by concentrator when the patient is using three or more cylinders per month independent of the duration of the prescription. More widespread use of concentrators at this level of provision is likely to lead to a cost saving. Conclusions The Drug Tariff prescribing guidelines, advocating that provision of oxygen by concentrator becomes cheaper when 21 cylinders are being used per month—are currently inaccurate in Northern Ireland. Regional health authorities should review their current arrangements for provision of oxygen at home and perform a cost analysis to determine at what level it becomes more cost effective to provide oxygen by concentrator. Key messagesThe current Drug Tariff prescribing guidelines are not cost effective for provision of oxygen at home in Northern IrelandIndividual prescriptions detailing frequency of usage and delivery costs should be recordedA switch to a more cost effective strategy is likely to result in a cost savingRegional health authorities should examinecurrent arrangements for provision of oxygen at home and should perform cost analyses PMID:10390453

Effects of glyphosate exposure on sperm concentration in rodents: A systematic review and meta-analysis.

PubMed

Cai, Wenyan; Ji, Ying; Song, Xianping; Guo, Haoran; Han, Lei; Zhang, Feng; Liu, Xin; Zhang, Hengdong; Zhu, Baoli; Xu, Ming

2017-10-01

Correlation between exposure to glyphosate and sperm concentrations is important in reproductive toxicity risk assessment for male reproductive functions. Many studies have focused on reproductive toxicity on glyphosate, however, results are still controversial. We conducted a systematic review of epidemiological studies on the association between glyphosate exposure and sperm concentrations of rodents. The aim of this study is to explore the potential adverse effects of glyphosate on reproductive function of male rodents. Systematic and comprehensive literature search was performed in MEDLINE, TOXLINE, Embase, WANFANG and CNKI databases with different combinations of glyphosate exposure and sperm concentration. 8 studies were eventually identified and random-effect model was conducted. Heterogeneity among study results was calculated via chi-square tests. Ten independent experimental datasets from these eight studies were acquired to synthesize the random-effect model. A decrease in sperm concentrations was found with mean difference of sperm concentrations(MDsperm)=-2.774×10 6 /sperm/g/testis(95%CI=-0.969 to -4.579) in random-effect model after glyphosate exposure. There was also a significant decrease after fitting the random-effect model: MDsperm=-1.632×10 6 /sperm/g/testis (95%CI=-0.662 to -2.601). The results of meta-analysis support the hypothesis that glyphosate exposure decreased sperm concentration in rodents. Therefore, we conclude that glyphosate is toxic to male rodent's reproductive system. Copyright © 2017. Published by Elsevier B.V.

Combustion characteristics of fine- and micro-pulverized coal in the mixture of O{sub 2}/CO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiangyong Huang; Xiumin Jiang; Xiangxin Han

The effects of oxygen concentration, particle size, and heating rate on the coal combustion characteristics under an O{sub 2}/CO{sub 2} atmosphere were investigated. The results indicated that the oxygen concentration played the most important role. As the oxygen concentration increases, the ignition and burnout temperatures decrease and the comprehensive combustion property index S increases. Moreover, the improvement of the oxygen concentration intensified the effects of the other factors. The ignition mechanism changes from hetero-homogeneous type to homogeneous type as the oxygen concentration increases. The ignition and burnout temperatures decrease slightly as the mean particle size decreases, and the index Smore » increases measurably as the mean particle size decreases. The heating rate has different effects on the ignition temperature, burnout temperature, and index S at different oxygen concentrations. 19 refs., 9 figs., 2 tabs.« less

Phosphorus-zinc interactive effects on growth by Selenastrum capricornutum (chlorophyta)

USGS Publications Warehouse

Kuwabara, J.S.

1985-01-01

Culturing experiments in chemically defined growth media were conducted to observe possible Zn and P interactions on Selenastrum capricornutum Printz growth indexes. Elevated Zn concentrations (7.5 ?? 10-8 and 1.5 ?? 10-7 M [Zn2+]) were highly detrimental to algal growth, affecting lag, exponential, and stationary growth phases. P behaved as a yield-limiting nutrient with maximum cell densities increasing linearly with total P. This yield limitation was intensified at elevated Zn concentrations. Although calculated cellular phosphorus concentrations increased markedly with Zn ion activity, elevated Zn concentrations had no apparent effect on rates of phosphorus uptake estimated for Selenastrum during exponential growth. Results indicated that P-Zn interactions were significant in describing Selenastrum cell yield results and are consistent with previous Zn studies on chlorophytes. These P-Zn interactions and the observed inhibitory growth effects of submicromolar Zn concentrations suggest that in nature an apparent P yield-limiting condition may result from elevated Zn concentrations.

High concentration effects of neutral-potential-well interface traps on recombination dc current-voltage lineshape in metal-oxide-silicon transistors

NASA Astrophysics Data System (ADS)

Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

2008-11-01

Steady-state Shockley-Read-Hall kinetics is employed to explore the high concentration effect of neutral-potential-well interface traps on the electron-hole recombination direct-current current-voltage (R-DCIV) properties in metal-oxide-silicon field-effect transistors. Extensive calculations include device parameter variations in neutral-trapping-potential-well electron interface-trap density NET (charge states 0 and -1), dopant impurity concentration PIM, oxide thickness Xox, forward source/drain junction bias VPN, and transistor temperature T. It shows significant distortion of the R-DCIV lineshape by the high concentrations of the interface traps. The result suggests that the lineshape distortion observed in past experiments, previously attributed to spatial variation in surface impurity concentration and energy distribution of interface traps in the silicon energy gap, can also arise from interface-trap concentration along surface channel region.

Parabolic Dish Concentrator (PDC-1)

NASA Technical Reports Server (NTRS)

Dennison, E. W.; Argoud, M. J.

1984-01-01

The design, construction, and installation of the Parabolic Dish Concentrator, Type 1 (PDC-1) has been one of the most significant JPL concentrator projects because of the knowledge gained about this type of concentrator and the development of design, testing, and analysis procedures which are applicable to all solar concentrator projects. The need for these procedures was more clearly understood during the testing period which started with the prototype panel evaluation and ended with the performance characterization of the completed concentrator. For each phase of the test program, practical test procedures were required and these procedures defined the mathematical analysis which was essential for successful concentrator development. The concentrator performance appears to be limited only by the distortions resulting from thermal gradients through the reflecting panels. Simple optical testing can be extremely effective, but comprehensive mechanical and optical analysis is essential for cost effective solar concentrator development.

Ranking filter methods for concentrating pathogens in lake water

USDA-ARS?s Scientific Manuscript database

Accurately comparing filtration methods for concentrating waterborne pathogens is difficult because of two important water matrix effects on recovery measurements, the effect on PCR quantification and the effect on filter performance. Regarding the first effect, we show how to create a control water...

Effects of limonene on ruminal concentrations, fermentation, and lysine degradation in cattle.

PubMed

Samii, S Saed; Wallace, N; Nagaraja, T G; Engstrom, M A; Miesner, M D; Armendariz, C K; Titgemeyer, E C

2016-08-01

Previous in vitro data showed that was inhibited by limonene. We further evaluated effects of limonene on growth of in vitro as well as on ruminal concentrations of in vivo. With in vitro cultivation in anaerobic brain-heart infusion broth, limonene decreased growth of . Thymol also reduced growth of , but it was less effective than limonene. Tylosin effectively reduced growth of in vitro. Although the response over fermentation times and concentrations of antimicrobials differed somewhat between tylosin and limonene, the 2 antimicrobial agents yielded similar inhibitory effects on growth of at concentrations ranging from 6 to 24 mg/L. The effects of limonene on ruminal concentration in vivo were tested in 7 ruminally cannulated heifers (225 kg initial BW) used in a 7 × 4 Youden square design. Treatments included: 1) control, 2) limonene at 10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, and 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples of ruminal contents were collected before treatment initiation and after 4, 7, and 10 d of treatment for measuring by the most probable number method using selective culture medium. Limonene linearly decreased ( = 0.03) ruminal concentration, with the lowest concentration achieved with 40 mg of limonene/kg dietary DM. Limonene tended ( ≤ 0.07) to linearly reduce ruminal molar proportions of propionate and valerate while tending to linearly increase ( ≤ 0.10) those of butyrate and 2-methyl butyrate. Limonene did not affect ruminal NH concentrations or degradation rates of lysine. Neither CRINA-L ( = 0.52) nor tylosin ( = 0.19) affected ruminal concentrations. CRINA-L significantly decreased ruminal concentrations of NH and molar proportions of 3-methyl butyrate, whereas tylosin significantly decreased molar proportions of propionate while increasing those of butyrate and tending to increase those of acetate. Limonene supplementation reduced ruminal concentrations of suggesting that it may have the potential to reduce the prevalence of liver abscesses, although further research is needed to assess the effect of limonene in feedlot cattle.

[Analyze nanofiltration separation rule of chlorogenic acid from low concentration ethanol by Donnan effect and solution-diffusion effect].

PubMed

Li, Cun-Yu; Liu, Li-Cheng; Jin, Li-Yang; Li, Hong-Yang; Peng, Guo-Ping

2017-07-01

To separate chlorogenic acid from low concentration ethanol and explore the influence of Donnan effect and solution-diffusion effect on the nanofiltration separation rule. The experiment showed that solution pH and ethanol volume percent had influences on the separation of chlorogenic acid. Within the pH values from 3 to 7 for chlorogenic acid in 30% ethanol, the rejection rate of chlorogenic acid was changed by 70.27%. Through the response surface method for quadratic regression model, an interaction had been found in molecule weight cut-off, pH and ethanol volume percent. In fixed nanofiltration apparatus, the existence states of chlorogenic acid determinedits separation rules. With the increase of ethanol concentration, the free form chlorogenic acid was easily adsorbed, dissolved on membrane surface and then caused high transmittance due to the solution-diffusion effect. However, at the same time, due to the double effects of Donnan effect and solution-diffusion effect, the ionic state of chlorogenic acid was hard to be adsorbed in membrane surface and thus caused high rejection rate. The combination of Box-Behnken design and response surface analysis can well optimize the concentrate process by nanofiltration, and the results showed that nanofiltration had several big advantages over the traditional vacuum concentrate technology, meanwhile, and solved the problems of low efficiency and serious component lossesin the Chinese medicines separation process for low concentration organic solvent-water solution. Copyright© by the Chinese Pharmaceutical Association.

Supplementation with Ca salts of soybean oil interacts with concentrate level in grazing dairy cows: intake, ingestive behavior, and ruminal parameters.

PubMed

Macedo, Fernanda Lopes; Batistel, Fernanda; de Souza, Jonas; Chagas, Lucas Jado; Santos, Flávio Augusto Portela

2016-12-01

In this study, we investigated the associative effects of concentrate levels and Ca salts of soybean oil (CSSO) supplementation on performance and ruminal parameters of mid-lactation dairy cows grazing on tropical pasture. Twenty-four Jersey × Holstein cows were used in a randomized block design and assigned to four treatments arranged in a 2 × 2 factorial design. Factors evaluated were concentrate levels (low, 3 kg/day vs. high, 7 kg/day of concentrate) and CSSO supplementation (without CSSO vs. with 250 g CSSO cow/day). All cows grazed on elephant grass (Pennisetum purpureum cv. Cameroon) and received the supplemental treatments for a 90-day period. The high concentrate level decreased forage intake and grazing time. In addition, the high concentrate level increased rumen propionate concentration and microbial synthesis and tended to decrease ammonia-N compared with low concentrate level. The addition of CSSO tended to decrease valerate, isobutyrate, isovalerate, and microbial synthesis. In conclusion, feeding CSSO for mid lactating cows grazing on tropical pasture had negative effects on rumen function. In contrast, CSSO supplementation tended to interact with concentrate level and increased energy intake when fed at low concentrate level. Feeding the high level of concentrate was an effective strategy to increase energy intake and microbial synthesis and improve N utilization.

Effects of yttrium, aluminum, and chromium concentrations in bond coatings on the performance of zirconia-yttria thermal barriers

NASA Technical Reports Server (NTRS)

Stecura, S.

1979-01-01

A cyclic furnace study was conducted between 990 - 280 C and 1095 - 280 C to evaluate the effects of yttrium, chromium, and aluminum concentrations in nickel base alloy bond coatings and also the effect of the bond coating thickness on the performance of yttria-stabilized zirconia thermal barrier coatings. The presence and the concentration of yttrium is very critical. Without yttrium, rapid oxidation of Ni-Al, Ni-Cr, and Ni-Cr-Al bond coatings causes zirconia thermal barrier coatings to fail very rapidly. Concentrations of chrominum and aluminum in Ni-Cr-Al-Y bond coating have a very significant effect on the thermal barrier coating life. This effect, however, is not as great as that due to yttrium. Furthermore, the thickness and the thickness uniformity also have a very significant effect on the life of the thermal barrier system.

Does the intestinal microenvironment have an impact on the choleretic effect of inchinkoto, a hepatoprotective herbal medicine?

PubMed

Uji, Masahito; Yokoyama, Yukihiro; Asahara, Takashi; Ebata, Tomoki; Igami, Tsuyoshi; Mizuno, Takashi; Yamaguchi, Junpei; Nagino, Masato

2018-02-01

The choleretic effects of inchinkoto (ICKT), a hepatoprotective herbal medicine, are variable among patients. This study sought to investigate the correlation between the choleretic effects of ICKT and the intestinal microenvironment in patients with biliary obstruction. Patients with biliary obstruction who underwent external biliary drainage were enrolled. The concentrations of total bilirubin and bile acid in the bile, and genipin, a major active ingredient of ICKT, in the bloodstream before and after ICKT treatment were measured. Feces were collected from the patients to determine bacterial count and organic acid concentrations. Samples from 37 patients were collected and analyzed. The serum concentration of genipin increased 3 h after ICKT treatment and showed a positive correlation with the percent changes of biliary concentrations of bile acid, total bilirubin, and direct bilirubin. Serum genipin concentration also showed a positive correlation with the fecal concentrations of representative obligate anaerobes such as the Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium, and the Atopobium cluster. In sharp contrast, so-called harmful bacteria such as Clostridium difficile, Enterobacteriaceae, and Enterococcus showed a negative correlation with the concentration of genipin. Genipin concentration after ICKT administration showed a positive correlation with the fecal concentration of short chain fatty acids such as propionic acid and butyric acid, and a negative correlation with the fecal concentration of lactic acid. The absorption of genipin was variable among patients. This variability may be associated with the fecal microenvironment profile and partly explain the variable choleretic effects of ICKT among patients. © 2017 The Japan Society of Hepatology.

[Relationship between atmospheric particles and rain water chemistry character].

PubMed

Huo, Ming-Qun; Sun, Qian; Xie, Peng; Bai, Yu-Hua; Liu, Zhao-Rong; Li, Ji-Long; Lu, Si-Hua

2009-11-01

Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 microeq x L(-1). The mass concentration of PM10 in Taian was 131.76 microg/m3 and that of PM2.5 was 103.84 microg/m3. The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 microeq x L(-1). The mass concentration of PM10 in Shenzhen was 56.66 microg/m3 and that of PM2.5 was 41.52 microg/m3. During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na+ and Ca2+ by rain is high and which of NH4+ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

A Pilot Study of the Usefulness of a Single Olanzapine Plasma Concentration as an Indicator of Early Drug Effect in a Small Sample of First-Episode Psychosis Patients

PubMed Central

Zabala, Arantzazu; Bustillo, Mariana; Querejeta, Imanol; Alonso, Marta; Mentxaka, Oiane; González-Pinto, Ana; Ugarte, Amaia; Meana, J. Javier; Gutiérrez, Miguel; Segarra, Rafael

2017-01-01

Abstract Purpose/Background Studies analyzing concentration-effect relationships in second-generation antipsychotics have reported contradictory results in chronic schizophrenia. No data are available for the early stages of the disease. The present study aims to evaluate the association between a single olanzapine plasma concentration, clinical response, and severity of adverse effects in first-episode psychosis (FEP); to test the utility of various plasma breakpoints as markers of early response to treatment; and to identify variables affecting olanzapine concentrations. Methods Data from 23 compliant FEP patients receiving olanzapine monotherapy (5–30 mg/d) were evaluated 2 months after beginning treatment. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale and the Montgomery-Åsberg Depression Rating Scale. Adverse effects were rated using the Udvalg for Kliniske Undersøgelser scale. Plasma samples were drawn at 11 (SD, 1) hours after dosing and analyzed with high-performance liquid chromatography/tandem mass spectrometry. Findings Consistent with findings on chronic disease, dose, age, sex, weight, and cigarettes/day accounted for some of the variability in olanzapine concentrations. While no relationship was found between olanzapine concentrations and adverse effects or improvement of depressive symptoms, response of psychotic symptoms was associated with concentrations between 22.56 and 77.92 ng/mL. Plasma breakpoints did not show sufficiently high specificity, resulting in a large number of false-positive results. Implications Although olanzapine concentrations do not seem to be reliable indicators of early drug effect in FEP, they may still prove useful for detecting noncompliance, as well as pharmacokinetically relevant comorbidities or genetic particularities in drug metabolism. PMID:28796022

Effects of egg order on organic and inorganic element concentrations and egg characteristics in tree swallows, tachycineta bicolor

USGS Publications Warehouse

Custer, Christine M.; Gray, B.R.; Custer, T.W.

2010-01-01

The laying order of tree swallow eggs was identified from the Housatonic River, Berkshire County, Massachusetts, USA, and eggs were chemically analyzed individually to document possible effects of laying order on organic contaminant and inorganic element concentrations. Effects of laying order on other parameters such as egg weight, size, and lipid and moisture content also were assessed. Some effects of egg order on total polychlorinated biphenyls (PCBs) were detected, but the effect was not uniform across individual females or between years. In 2004, clutches with higher total PCBs tended to have concentrations decline across egg order, whereas clutches with lower concentrations of PCBs tended to increase across egg order. In contrast, in 2005, there was a tendency for concentrations to increase across egg order. Polychlorinated biphenyl concentrations were highly variable within and among clutches in both years. The directionality of egg order associations (i.e., slopes) for trace elements was element dependent, was positive for Mn and Zn, was negative for B, and had no slope for Cr. Whole egg weight increased across egg order. Percentage lipid was variable within a clutch, with no pattern common across all females. Percentage lipid was also correlated with organic contaminant concentration. In highly contaminated environments, higher lipid content could have the unanticipated corollary of having higher concentrations of lipophilic contaminants such as PCBs. To reduce the effect of high variation within a clutch when assessing contamination exposure, it is recommended that two eggs per clutch be collected and pooled for chemical analysis. We further recommend that, as long as the two eggs are randomly collected, the additional effort needed to identify and collect specific eggs is not warranted. ?? 2009 SETAC.

Development of a Tumour Growth Inhibition Model to Elucidate the Effects of Ritonavir on Intratumoural Metabolism and Anti-tumour Effect of Docetaxel in a Mouse Model for Hereditary Breast Cancer.

PubMed

Yu, Huixin; Hendrikx, Jeroen J M A; Rottenberg, Sven; Schellens, Jan H M; Beijnen, Jos H; Huitema, Alwin D R

2016-03-01

In a mouse tumour model for hereditary breast cancer, we previously explored the anti-cancer effects of docetaxel, ritonavir and the combination of both and studied the effect of ritonavir on the intratumoural concentration of docetaxel. The objective of the current study was to apply pharmacokinetic (PK)-pharmacodynamic (PD) modelling on this previous study to further elucidate and quantify the effects of docetaxel when co-administered with ritonavir. PK models of docetaxel and ritonavir in plasma and in tumour were developed. The effect of ritonavir on docetaxel concentration in the systemic circulation of Cyp3a knock-out mice and in the implanted tumour (with inherent Cyp3a expression) was studied, respectively. Subsequently, we designed a tumour growth inhibition model that included the inhibitory effects of both docetaxel and ritonavir. Ritonavir decreased docetaxel systemic clearance with 8% (relative standard error 0.4%) in the co-treated group compared to that in the docetaxel only-treated group. The docetaxel concentration in tumour tissues was significantly increased by ritonavir with mean area under the concentration-time curve 2.5-fold higher when combined with ritonavir. Observed tumour volume profiles in mice could be properly described by the PK/PD model. In the co-treated group, the enhanced anti-tumour effect was mainly due to increased docetaxel tumour concentration; however, we demonstrated a small but significant anti-tumour effect of ritonavir addition (p value <0.001). In conclusion, we showed that the increased anti-tumour effect observed when docetaxel is combined with ritonavir is mainly caused by enhanced docetaxel tumour concentration and to a minor extent by a direct anti-tumour effect of ritonavir.

Flavor-Intensity Perception: Effects of Stimulus Context

PubMed Central

Marks, Lawrence E.; Shepard, Timothy G.; Burger, Kelly; Chakwin, Emily M.

2011-01-01

Stimulus context affects judgments of intensity of both gustatory and olfactory flavors, and the contextual effects are modality-specific. Does context also exert separate effects on the gustatory and olfactory components of flavor mixtures? To answer this question, in each of 4 experiments, subjects rated the perceived intensity of 16 mixtures constructed by combining 4 concentrations of the gustatory flavorant sucrose with 4 concentrations of the retronasal olfactory flavorant citral. In 1 contextual condition of each experiment, concentrations of sucrose were relatively high and those of citral low; in the other condition, the relative concentrations of sucrose and citral reversed. There were 2 main results: First, consistent with earlier findings, in 5 of the 8 conditions, the ratings were consistent with linear addition of perceived sucrose and citral; departures from additivity appeared, however, in 3 conditions where the relative concentrations of citral were high. Second, changes in context produced contrast (adaptation-like changes) in perceived intensity: The contribution to perceived intensity of a given concentration of a flavorant was smaller when the contextual concentrations of that flavorant were high rather than low. A notable exception was the absence of contextual effects on the perceived intensity of near-threshold citral. These findings suggest that the contextual effects may arise separately in the gustatory and olfactory channels, prior to the integration of perceived flavor intensity. PMID:21930139

[Effect of exogenous sucrose on growth and active ingredient content of licorice seedlings under salt stress conditions].

PubMed

Liu, Fu-zhi; Yang, Jun

2015-11-01

Licorice seedlings were taken as experimental materials, an experiment was conducted to study the effects of exogenous sucrose on growth and active ingredient content of licorice seedlings under NaCl stress conditions. The results of this study showed that under salt stress conditions, after adding a certain concentration of exogenous sucrose, the licorice seedlings day of relative growth rate was increasing, and this stress can be a significant weakening effect, indicating that exogenous sucrose salt stress-relieving effect. The total flavonoids and phenylalanine ammonia lyase (PAL) activity were significantly increased, the exogenous sucrose can mitigated the seedling roots under salt stress, the licorice flavonoid content in the enhanced growth was largely due to the activity of PAL an increased, when the concentration of exogenous sucrose wae 10 mmol x L(-1), PAL activity reaching a maximum, when the concentration of exogenous sucrose was 15 mmol x L(-1), PAL activity turned into a downward trend, the results indicating that this mitigation has concentration effect. After applying different concentrations of exogenous sugar, the contents of liquiritin changes with the change of flavonoids content was similar. After applying different concentrations of exogenous sucrose, the content of licorice acid under salt stress was higher than the levels were not reached during salt stress, the impact of exogenous sucrose concentration gradient of licorice acid accumulation was not obvious.

Effect of NaNO3 concentration on anodic electrochemical behavior on the Sb surface in NaOH solution

NASA Astrophysics Data System (ADS)

He, Yun-long; Xu, Rui-dong; He, Shi-wei; Chen, Han-sen; Li, Kuo; Zhu, Yun; Shen, Qing-feng

2018-03-01

The effect of NaNO3 concentration on the anodic electrochemical behavior of antimony in 4 M NaOH solution was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses. The mechanism of NO 3 - concentration effect on the anodic electrochemical behavior of antimony was proposed, and its availability was confirmed by experimental results. The effect of NaNO3 on the anodic behavior of antimony in NaOH solution can be interpreted as a stepwise formation of different antimony compounds with different NaNO3 concentrations. Metallic antimony is apt to be oxidized into Sb2O3 within the NaNO3 concentration range of 0-0.48 M. NaSbO3 can be found on the antimony surface when the NaNO3 concentration increases gradually. Insoluable NaSbO3 inhibits the anodic oxidation of antimony due to its shielding effect on the mass transport of the reactants and products. Surface morphology and composition were analyzed by X-ray photoelectron spectroscopy (XPS), scanning electronic microscopy (SEM), and electron dispersion spectroscopy (EDS) analyses. Results indicate that the anodic oxidation layer is composed of Sb2O3, NaSbO3, and Sb. The atomic proportion of antimony in the form of NaSbO3 increases with increasing NaNO3 concentration due to the powerful oxidizing property of NaNO3.

A comparison of the effects of 2 doses of soy protein or casein on serum lipids, serum lipoproteins, and plasma total homocysteine in hypercholesterolemic subjects.

PubMed

Tonstad, Serena; Smerud, Knut; Høie, Lars

2002-07-01

Studies have shown that soy protein reduces some atherogenic lipid and lipoprotein concentrations, although lipoprotein(a) concentrations may be increased. The dose response of soy protein has not been established; neither has its effect on plasma total homocysteine. Our objective was to evaluate the effect of 2 doses of soy protein on lipid, lipoprotein, and homocysteine concentrations. Four to 24 wk after being instructed to consume a lipid-lowering diet, 130 men and women with LDL-cholesterol concentrations > or = 4 mmol/L were studied during a parallel group trial in which 4 interventions were assigned randomly. Thirty grams isolated soy protein (ISP) and 10 g cotyledon fiber or 50 g ISP and 16.6 g cotyledon fiber or equivalent doses of casein and cellulose were consumed daily as a beverage for 16 wk. When the 2 groups who consumed ISP were compared with the 2 groups who consumed casein, the differences in the net changes from baseline to week 16 in the concentrations of LDL cholesterol and plasma total homocysteine were -0.26 mmol/L (95% CI: -0.43, -0.09 mmol/L; P = 0.01) and -0.8 micromol/L (-1.4, -0.2 micromol/L; P = 0.005), respectively. The effect of the ISP dose was not significant. There were no significant differences between the 2 ISP and the 2 casein groups in changes in lipoprotein(a), HDL-cholesterol, or triacylglycerol concentrations. Adding 30-50 g soy protein/d to a lipid-lowering diet significantly reduced LDL-cholesterol concentrations without increasing lipoprotein(a) concentrations. Plasma total homocysteine concentrations also decreased, suggesting a novel, possibly antiatherosclerotic effect.

The effect of concentration of guanidine hydrochloride on the sulfasalazine serum albumin complex

NASA Astrophysics Data System (ADS)

Sułkowska, A.; Równicka, J.; Pożycka, J.; Bojko, B.; Sułkowski, W. W.

2005-06-01

A detailed study of the effect of Gu·HCl concentration is presented in this work. Destabilization of the tertiary structure of BSA was observed by using fluorescence measurements of excitation wavelength of 280 and 295 nm. We ascertained that in terms of the effect on the fluorescence emission spectrum of BSA, Gu·HCl concentration falls into three regions: I, 0.1-1.6 M; II, 1.6-3 M and III, 3-6 M. The intermediate state of BSA denaturation for 1.6-1.7 M Gu·HCl was noticed. Quenching of the native BSA fluorescence by sulfasalazine (SSZ), a drug used in inflammatory bowel disease, was shown. In the presence of Gu·HCl, BSA fluorescence rises or decreases depending on the concentration region I or II, respectively. A similar effect of Gu·HCl on the fluorescence spectrum of BSA, quenched by sulfasalazine, can be found. However, Gu·HCl concentration-dependent reduction of the quenching effect of the SSZ points to the gradual loss of the binding properties. Binding and quenching constants for the SSZ-BSA complexes were calculated in the absence and presence of the denaturant. Since Gu·HCl at concentration 0.1-1.6 M increases and at concentration 1.6-3 M decreases the BSA fluorescence, the mechanism of the destabilization of the native structure of serum albumin differs for these two ranges of Gu·HCl concentration. The small concentration of the denaturant causes a disorder in the hydration layer of the albumin and the higher one causes the binding of the denaturant molecule close to the Trp 135 in the IB subdomain.

Concentration-dependent metabolic effects of metformin in healthy and Fanconi anemia lymphoblast cells.

PubMed

Ravera, Silvia; Cossu, Vanessa; Tappino, Barbara; Nicchia, Elena; Dufour, Carlo; Cavani, Simona; Sciutto, Andrea; Bolognesi, Claudia; Columbaro, Marta; Degan, Paolo; Cappelli, Enrico

2018-02-01

Metformin (MET) is the drug of choice for patients with type 2 diabetes and has been proposed for use in cancer therapy and for treating other metabolic diseases. More than 14,000 studies have been published addressing the cellular mechanisms affected by MET. However, several in vitro studies have used concentrations of the drug 10-100-fold higher than the plasmatic concentration measured in patients. Here, we evaluated the biochemical, metabolic, and morphologic effects of various concentrations of MET. Moreover, we tested the effect of MET on Fanconi Anemia (FA) cells, a DNA repair genetic disease with defects in energetic and glucose metabolism, as well as on human promyelocytic leukemia (HL60) cell lines. We found that the response of wild-type cells to MET is concentration dependent. Low concentrations (15 and 150 µM) increase both oxidative phosphorylation and the oxidative stress response, acting on the AMPK/Sirt1 pathway, while the high concentration (1.5 mM) inhibits the respiratory chain, alters cell morphology, becoming toxic to the cells. In FA cells, MET was unable to correct the energetic/respiratory defect and did not improve the response to oxidative stress and DNA damage. By contrast, HL60 cells appear sensitive also at 150 μM. Our findings underline the importance of the MET concentration in evaluating the effect of this drug on cell metabolism and demonstrate that data obtained from in vitro experiments, that have used high concentrations of MET, cannot be readily translated into improving our understanding of the cellular effects of metformin when used in the clinical setting. © 2017 Wiley Periodicals, Inc.

Local anesthetics differentially inhibit sympathetic neuron-mediated and C fiber-mediated synovial neurogenic plasma extravasation.

PubMed

Pietruck, Christian; Grond, Stefan; Xie, Guo-Xi; Palmer, Pamela P

2003-05-01

Local anesthetics are used for local irrigation after many types of operations. However, recent evidence of toxic effects of local anesthetics at large concentrations during continuous administration suggests an advantage of using decreased local anesthetic concentrations for irrigation solutions. In this study, we determined whether smaller concentrations of local anesthetics may maintain an antiinflammatory and, therefore, analgesic effect without the risk of possible toxicity. Lidocaine and bupivacaine were studied for their ability to inhibit both components of neurogenic inflammation-C fiber-mediated and sympathetic postganglionic neuron (SPGN)-mediated inflammation-in the rat knee joint. Intraarticular lidocaine 0.02% reduced 5-hydroxytryptamine (5-HT)-induced (SPGN-mediated) plasma extravasation (PE) by 35%, and further decreases were obtained by perfusing larger concentrations of lidocaine. Intraarticular bupivacaine 0.025% inhibited 5-HT-induced PE by 60%, and a 95% inhibition was obtained with bupivacaine 0.05%. Larger local anesthetic concentrations were necessary to inhibit C fiber-mediated PE than those required to inhibit SPGN-mediated PE. Lidocaine 0.4% was required to reduce mustard oil-induced PE by 60%. Lidocaine 2% inhibited mustard oil-induced PE to baseline levels. Bupivacaine 0.1% was required for an 80% reduction of PE. Bupivacaine 0.25% inhibited mustard oil-induced PE to baseline levels. Our results demonstrate differential effects of local anesthetics on SPGN- and C fiber-mediated PE but confirm the concept of using smaller concentrations of local anesthetics to achieve inhibition of postoperative inflammation. Local anesthetic wound irrigation is often used to treat postoperative surgical pain. Large concentrations of local anesthetics are usually used, and these concentrations may have possible neurotoxic and myotoxic effects. Our results demonstrate antiinflammatory effects of lidocaine and bupivacaine at concentrations smaller than used clinically.

Plasma concentrations of prolactin in overtly pseudopregnant Afghan hounds and the effect of metergoline.

PubMed

Okkens, A C; Dieleman, S J; Kooistra, H S; Bevers, M M

1997-01-01

The effect of metergoline, a 5-hydroxytryptamine (serotonin) antagonist, on the plasma concentrations of prolactin in overtly pseudopregnant Afghan hounds and on the clinical symptoms of overt pseudopregnancy were studied. Plasma concentrations of prolactin and progesterone were determined in six Afghan hounds with signs of overt pseudopregnancy for 2-3 weeks and in three Afghan hounds that were not pseudopregnant at the time of blood sampling. In the overtly pseudopregnant bitches the plasma concentrations of prolactin before treatment (35.5 +/- 8.5 micrograms l-1) were significantly higher than the plasma concentrations of prolactin of the three bitches that were not pseudopregnant (6.3 +/- 0.5 micrograms l-1); the latter values were similar to those of non-pseudopregnant beagle bitches during the total luteal phase. The six pseudopregnant Afghan hounds were treated for 10 days with the antiserotoninergic drug metergoline. At 2 h after the onset of treatment with metergoline, the mean plasma concentration of prolactin had decreased to 10.8 +/- 2.9 micrograms l-1. The plasma concentrations of prolactin continued to decline to 5.4 +/- 1.0 micrograms l-1 at 4 h and to 1.0 +/- 0.1 microgram l-1 during treatment days 3-10. Signs of pseudopregnancy, such as swelling of the mammary glands and digging, decreased during the treatment period. The treatment was associated with mild behavioural side effects such as whimpering and aggressiveness. These side effects are probably not related to suppression of prolactin but are due to a direct effect on serotoninergic pathways in the brain. It is concluded that high plasma concentrations of prolactin are associated with the development and maintenance of pseudopregnancy. The serotonin antagonist metergoline strongly suppresses plasma concentrations of prolactin in pseudopregnant dogs and decreases the clinical signs of pseudopregnancy.

[Plasma prolactin concentration and the effect of metergoline in pseudopregnant Afghan hounds].

PubMed

Okkens, A C; Dieleman, S J; Kooistra, H S; Bevers, M M

2000-02-01

The effects of metergoline, a 5-hydroxytryptamine (serotinin) antagonist, on the plasma concentrations of prolactin in overtly pseudopregnant Afghan hounds and on the clinical symptoms of overt pseudopregnancy were studied. Plasma concentrations of prolactin and progesterone were determined in six Afghan hounds with signs of overt pseudopregnancy for 2-3 weeks and in three Afghan hounds that were not pseudopregnant at the time of blood sampling. In the overtly pseudopregnant bitches the plasma concentrations of prolactin before treatment (35.5 +/- 8.5 micrograms l-1) were significantly higher than the plasma concentrations of prolactin of the three bitches that were not pseudopregnant (6.3 +/- 0.5 micrograms l-1); the latter values were similar to those of non-psueodopregnant beagle bitches during the total luteal phase. The six pseudopregnant Afghan hounds were treated for 10 days with the antiserotoninergic drug metergoline. At 2 h after the onset of treatment with metergoline, the mean plasma concentration of prolactin had decreased to 10.8 +/- 2.9 micrograms l-1. The plasma concentrations of prolactin continued to decline to 5.4 +/- 1.0 micrograms l-1 at 4 h and to 1.0 +/- 0.1 microgram l-1 during treatment days 3-10. Signs of pseudopregnancy, such as swelling of the mammary glands and digging, decreased during the treatment period. The treatment was associated with mild behavioural side effects such as whimpering and aggressiveness. These side effects are probably not related to suppression of prolactin but are due to a direct effect on serotoninergic pathways in the brain. It is concluded that high plasma concentrations of prolactin are associated with the development and maintenance of pseudopregnancy. The serotonin antagonist metergoline strongly suppresses plasma concentration of prolactine in pseudopregnant dogs and decreases the clinical signs of pseudopregnancy.

The effect of chronic prostatitis on zinc concentration of prostatic fluid and seminal plasma: a systematic review and meta-analysis.

PubMed

Cui, Dong; Han, GuangWei; Shang, YongGang; Mu, LiJun; Long, QingZhi; Du, YueFeng

2015-01-01

Prostatitis is a common disease in urology departments. Prostatic zinc accumulation is connected with the secretory function of the prostate, and zinc concentrations present in prostatic diseases differ greatly from the normal level. Studies have investigated the effect of chronic prostatitis on zinc concentration of prostatic fluid and seminal plasma, but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the effect of chronic prostatitis on the zinc concentration of prostatic fluid and seminal plasma. Systematic literature searches were conducted with PubMed, Embase, Science Direct/Elsevier, CNKI and the Cochrane Library up to March 2015 for case-control studies that involved the relationship between chronic prostatitis and zinc concentration of prostatic fluid and seminal plasma. Meta-analysis was performed with Review Manager and Stata software. Standard mean differences (SMDs) of zinc concentration were identified with 95% confidence intervals (95% CIs) in a random- or fixed-effects model. Our results illustrated that the zinc concentrations in prostatic fluid and seminal plasma from chronic prostatitis patients were significantly lower than normal controls (SMD [95% CI] -246.71 [-347.97, -145.44], -20.74 [-35.11, -6.37], respectively). The sample size of each study was relatively small, and a total of 731 chronic prostatitis patients and 574 normal controls were investigated in all fourteen studies. Several studies related to the subject were excluded due to lack of control data or means and standard deviations. The present study illustrates that there was a significant negative effect of chronic prostatitis on zinc concentrations of prostatic fluid and seminal plasma. Further studies with larger sample sizes are needed to better illuminate the negative impact of chronic prostatitis on zinc concentrations.

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.).

PubMed

La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

2009-06-01

The effects of CO(2) enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO(2) concentration was elevated from 350 to 800 microl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO(2) concentration, N concentration, and CO(2)xN interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO(2). However, at 20 mmol N/L, elevated CO(2) had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO(2) concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO(2) concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO(2) condition.

Sensory effect of acetaldehyde on the perception of 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine: Role of acetaldehyde in sensory interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coetzee, C.; Brand, J.; Jacobson, Daniel A.

Background and Aims-Wine aroma is influenced by complex interactions between various wine constituents. This study investigated the sensory interactive effects of Sauvignon Blanc impact compounds, 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine, with acetaldehyde that typically forms during the oxidation of wine. Methods and Results-Spiked model wines were subjected to sensory descriptive analysis using a trained sensory panel. Additionally, the concentration of each compound varied from below aroma threshold values to high values as reported for wine. Depending on the concentration, acetaldehyde enhanced fruity attributes at a lower concentration, whereas suppression occurred at a higher concentration. Acetaldehyde effectively suppressed the green pepper aroma attributemore » at certain concentration values, whereas 3-mercaptohexan-1-ol suppressed oxidised green apple associated with acetaldehyde. Changes in attributes used for aroma description also occurred because of change in concentration. Conclusions-Complex sensory interactions may occur between Sauvignon Blanc impact compounds and one of the main oxidation-derived compounds, acetaldehyde. Acetaldehyde can enhance or suppress pleasant fruity characters depending on the concentration. Significance of the Study-This study showed the potential positive effect of acetaldehyde on white wine aroma when present at a low concentration. Formation of this compound during winemaking and ageing should, however, be controlled because of negative sensory interactions occurring at a higher concentration. In conclusion, this study may also contribute to the sensory characterisation of Sauvignon Blanc wine undergoing oxidation.« less

Sensory effect of acetaldehyde on the perception of 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine: Role of acetaldehyde in sensory interactions

DOE PAGES

Coetzee, C.; Brand, J.; Jacobson, Daniel A.; ...

2016-01-28

Background and Aims-Wine aroma is influenced by complex interactions between various wine constituents. This study investigated the sensory interactive effects of Sauvignon Blanc impact compounds, 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine, with acetaldehyde that typically forms during the oxidation of wine. Methods and Results-Spiked model wines were subjected to sensory descriptive analysis using a trained sensory panel. Additionally, the concentration of each compound varied from below aroma threshold values to high values as reported for wine. Depending on the concentration, acetaldehyde enhanced fruity attributes at a lower concentration, whereas suppression occurred at a higher concentration. Acetaldehyde effectively suppressed the green pepper aroma attributemore » at certain concentration values, whereas 3-mercaptohexan-1-ol suppressed oxidised green apple associated with acetaldehyde. Changes in attributes used for aroma description also occurred because of change in concentration. Conclusions-Complex sensory interactions may occur between Sauvignon Blanc impact compounds and one of the main oxidation-derived compounds, acetaldehyde. Acetaldehyde can enhance or suppress pleasant fruity characters depending on the concentration. Significance of the Study-This study showed the potential positive effect of acetaldehyde on white wine aroma when present at a low concentration. Formation of this compound during winemaking and ageing should, however, be controlled because of negative sensory interactions occurring at a higher concentration. In conclusion, this study may also contribute to the sensory characterisation of Sauvignon Blanc wine undergoing oxidation.« less

Inhibition and Promotion of Heat-Induced Gelation of Whey Proteins in the Presence of Calcium by Addition of Sodium Caseinate.

PubMed

Nguyen, Bach T; Balakrishnan, Gireeshkumar; Jacquette, Boris; Nicolai, Taco; Chassenieux, Christophe; Schmitt, Christophe; Bovetto, Lionel

2016-11-14

Heat-induced aggregation and gelation of aqueous solutions of whey protein isolate (WPI) in the presence of sodium caseinate (SC) and CaCl 2 was studied at pH 6.6. The effect of adding SC (0-100 g/L) on the structure of the aggregates and the gels was investigated by light scattering and confocal laser scanning microscopy at different CaCl 2 concentration ([CaCl 2 ] = 0-30 mM). The gelation process was studied by oscillatory shear rheology. At the whey protein concentrations studied here (34 and 60 g/L), no gels were formed in the absence of CaCl 2 and SC. However, WPI solutions gelled above a critical CaCl 2 concentration that increased with increasing SC concentration. In the absence of CaCl 2 , WPI gels were formed only above a critical SC concentration. The critical SC concentration needed to induce WPI gelation decreased weakly when CaCl 2 was added. In an intermediate range of CaCl 2 concentrations, gels were formed both at low and high SC concentrations, but not at intermediate SC concentrations. Finally, at high CaCl 2 concentrations gels were formed at all SC concentrations. The gelation rate and the gel structure of the gels formed at low and high casein concentrations were very different. The effect of SC on the thermal gelation of WPI was interpreted by competition for Ca 2+ , a chaperon effect, and microphase separation.

Immediate and residual effects of heat stress and restricted intake on milk protein and casein composition and energy metabolism.

PubMed

Cowley, F C; Barber, D G; Houlihan, A V; Poppi, D P

2015-04-01

The effects of heat stress on dairy production can be separated into 2 distinct causes: those effects that are mediated by the reduced voluntary feed intake associated with heat stress, and the direct physiological and metabolic effects of heat stress. To distinguish between these, and identify their effect on milk protein and casein concentration, mid-lactation Holstein-Friesian cows (n = 24) were housed in temperature-controlled chambers and either subjected to heat stress [HS; temperature-humidity index (THI) ~78] or kept in a THI<70 environment and pair-fed with heat-stressed cows (TN-R) for 7 d. A control group of cows was kept in a THI<70 environment with ad libitum feeding (TN-AL). A subsequent recovery period (7 d), with THI<70 and ad libitum feeding followed. Intake accounted for only part of the effects of heat stress. Heat stress reduced the milk protein concentration, casein number, and casein concentration and increased the urea concentration in milk beyond the effects of restriction of intake. Under HS, the proportion in total casein of αS1-casein increased and the proportion of αS2-casein decreased. Because no effect of HS on milk fat or lactose concentration was found, these effects appeared to be the result of specific downregulation of mammary protein synthesis, and not a general reduction in mammary activity. No residual effects were found of HS or TN-R on milk production or composition after THI<70 and ad libitum intake were restored. Heat-stressed cows had elevated blood concentrations of urea and Ca, compared with TN-R and TN-AL. Cows in TN-R had higher serum nonesterified fatty acid concentrations than cows in HS. It was proposed that HS and TN-R cows may mobilize different tissues as endogenous sources of energy. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Combined Effects of Stress Concentration and Tensile Stresses from Autofrettage on the Life of Pressure Vessels

DTIC Science & Technology

2017-02-01

Technical Report ARWSB-TR-17011 THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF...SUBTITLE THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF PRESSURE VESSELS 5a. CONTRACT NUMBER...hydraulically or mechanically overstrained in order to impart favorable near bore residual compressive hoop stresses in an attempt to enhance fatigue life. As a

THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF PRESSURE VESSELS

DTIC Science & Technology

2017-02-22

Technical Report ARWSB-TR-17011 THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF...SUBTITLE THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF PRESSURE VESSELS 5a. CONTRACT NUMBER...hydraulically or mechanically overstrained in order to impart favorable near bore residual compressive hoop stresses in an attempt to enhance fatigue life. As a

Effects of watershed management practices on sediment concentrations in the southwestern United States: Management implications

Treesearch

Vicente L. Lopes; Peter F. Ffolliott; Malchus B. Baker

2000-01-01

Effects of watershed management practices on suspended sediment concentrations from ponderosa pine forests and pinyon-juniper woodlands in the Southwestern United States are examined. Completely cleared and strip-cut ponderosa pine watersheds produced higher sediment concentrations than the control. Likewise, cabled and herbicide-treated pinyon-juniper watersheds...

Effects of Movement Velocity and Maximal Concentric and Eccentric Actions on the Bilateral Deficit

ERIC Educational Resources Information Center

Dickin, D. Clark; Too, Danny

2006-01-01

This study was performed to examine the effects of movement velocity and maximal concentric and eccentric actions on the bilateral deficit. Eighteen female participants performed maximal unilateral and bilateral knee extensions concentrically and eccentrically across six movement velocities (30, 60, 90, 120, 150, and 180[degrees]/s). Repeated…

Effects of diurnal control in the mineral concentration of nutrient solution on tomato yield and nutrient absorption in hydroponics.

PubMed

Higashide, T; Shimaji, H; Takaichi, M

1996-12-01

We researched effects of diurnal change of the mineral concentration on tomato yield and nutrient absorption. First, we examined the effect on yield in a spray culture, in the experiment 1-1, when nitrate concentration of solution (N) and potassium concentration (K) were low and phosphate concentration (P) was high during the daytime, while N and K were high and P was low during the night, the yield was low. In the experiment 1-2, when N and K were high and P was low during the daytime, while N and K were low and P was high during the night, the yield was low. Second, we examined the effect on nutrient absorption in a water culture. Concentration of KNO3, of solution was changed in the daytime or the night. When KNO3 level was low during the daytime, while it was high during the night, total nitrate and potassium absorption for 24 hours was the highest. It were showed the possibility of the efficient supply of minerals to plants by the diurnal control in minerals.

Effects of must concentration techniques on wine isotopic parameters.

PubMed

Guyon, Francois; Douet, Christine; Colas, Sebastien; Salagoïty, Marie-Hélène; Medina, Bernard

2006-12-27

Despite the robustness of isotopic methods applied in the field of wine control, isotopic values can be slightly influenced by enological practices. For this reason, must concentration technique effects on wine isotopic parameters were studied. The two studied concentration techniques were reverse osmosis (RO) and high-vacuum evaporation (HVE). Samples (must and extracted water) have been collected in various French vineyards. Musts were microfermented at the laboratory, and isotope parameters were determined on the obtained wine. Deuterium and carbon-13 isotope ratios were studied on distilled ethanol by nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS), respectively. The oxygen-18 ratio was determined on extracted and wine water using IRMS apparatus. The study showed that the RO technique has a very low effect on isotopic parameters, indicating that this concentration technique does not create any isotopic fractionation, neither at sugar level nor at water level. The effect is notable for must submitted to HVE concentration: water evaporation leads to a modification of the oxygen-18 ratio of the must and, as a consequence, ethanol deuterium concentration is also modified.

The effect of dietary cation-anion difference concentration and cation source on milk production and feed efficiency in lactating dairy cows.

PubMed

Iwaniuk, M E; Weidman, A E; Erdman, R A

2015-03-01

Feed costs currently account for 55% or more of the total cost of milk production in US dairy herds, and dairy producers are looking for strategies to improve feed efficiency [FE; 3.5% fat-corrected milk (FCM) per dry matter (DM) intake]. Increasing dietary cation-anion difference [DCAD; Na+K-Cl (mEq/kg of DM)] has been shown to increase milk production, FCM, and FE. However, the optimal DCAD concentration for maximal FE has yet to be determined. The objectives of this research were to test the effects of DCAD concentration and cation source on dairy FE. Sixty Holstein dairy cows (20 cows per experiment) were used in three 4×4 Latin square design experiments with 3-wk experimental periods. In experiments 1 and 2, we tested the effect of DCAD concentration: cows were fed a basal diet containing ~250 mEq/kg of DM DCAD that was supplemented with potassium carbonate at 0, 50, 100, and 150 mEq/kg of DM or 0, 125, 250, and 375 mEq/kg of DM in experiments 1 and 2, respectively. In experiment 3, we tested the effect of cation source: sodium sesquicarbonate replaced 0, 33, 67, and 100% of the supplemental potassium carbonate (150 mEq/kg of DM DCAD). The DCAD concentration had no effect on milk production, milk protein concentration, or milk protein yield in experiments 1 and 2. Dry matter intake was not affected by DCAD concentration in experiment 1 or by cation source in experiment 3. However, DMI increased linearly with increasing DCAD in experiment 2. We detected a linear increase in milk fat concentration and yield with increasing DCAD in experiments 1 and 2 and by substituting sodium sesquicarbonate for potassium carbonate in experiment 3. Increased milk fat concentration with increasing DCAD led to increases in 3.5% FCM in experiments 1 and 2. Maximal dairy FE was achieved at a DCAD concentration of 426 mEq/kg of DM in experiments 1 and 2 and by substituting Na for K in experiment 3. The results of these experiments suggest that both DCAD concentration and the cation source used to alter DCAD concentration have effects on milk fat content and yield and dairy FE. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Combined Effects of Deforestation and Doubled Atmospheric CO2 Concentrations on the Climate of Amazonia.

NASA Astrophysics Data System (ADS)

Costa, Marcos Heil; Foley, Jonathan A.

2000-01-01

It is generally expected that the Amazon basin will experience at least two major environmental changes during the next few decades and centuries: 1) increasing areas of forest will be converted to pasture and cropland, and 2) concentrations of atmospheric CO2 will continue to rise. In this study, the authors use the National Center for Atmospheric Research GENESIS atmospheric general circulation model, coupled to the Integrated Biosphere Simulator, to determine the combined effects of large-scale deforestation and increased CO2 concentrations (including both physiological and radiative effects) on Amazonian climate.In these simulations, deforestation decreases basin-average precipitation by 0.73 mm day1 over the basin, as a consequence of the general reduction in vertical motion above the deforested area (although there are some small regions with increased vertical motion). The overall effect of doubled CO2 concentrations in Amazonia is an increase in basin-average precipitation of 0.28 mm day1. The combined effect of deforestation and doubled CO2, including the interactions among the processes, is a decrease in the basin-average precipitation of 0.42 mm day1. While the effects of deforestation and increasing CO2 concentrations on precipitation tend to counteract one another, both processes work to warm the Amazon basin. The effect of deforestation and increasing CO2 concentrations both tend to increase surface temperature, mainly because of decreases in evapotranspiration and the radiative effect of CO2. The combined effect of deforestation and doubled CO2, including the interactions among the processes, increases the basin-average temperature by roughly 3.5°C.

Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

USGS Publications Warehouse

Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

1996-01-01

Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs calculated using sediment concentrations normalized to total organic carbon (TOC) concentrations did not improve the reliability compared to SECs calculated using dry-weight concentrations. The range of TOC concentrations in our database was relatively narrow compared to the ranges of contaminant concentrations. Therefore, normalizing dry-weight concentrations to a relatively narrow range of TOC concentrations had little influence on relative concentra of contaminants among samples. When SECs are used to conduct a preliminary screening to predict the potential for toxicity in the absence of actual toxicity testing, a low number of SEC exceedances should be used to minimize the potential for false negatives; however, the risk of accepting higher false positives is increased.

Short-term effects of medetomidine on photosynthesis and protein synthesis in periphyton, epipsammon and plankton communities in relation to predicted environmental concentrations.

PubMed

Ohlauson, Cecilia; Eriksson, Karl Martin; Blanck, Hans

2012-01-01

Medetomidine is a new antifouling substance, highly effective against barnacles. As part of a thorough ecotoxicological evaluation of medetomidine, its short-term effects on algal and bacterial communities were investigated and environmental concentrations were predicted with the MAMPEC model. Photosynthesis and bacterial protein synthesis for three marine communities, viz. periphyton, epipsammon and plankton were used as effect indicators, and compared with the predicted environmental concentrations (PECs). The plankton community showed a significant decrease in photosynthetic activity of 16% at 2 mg l⁻¹ of medetomidine, which was the only significant effect observed. PECs were estimated for a harbor, shipping lane and marina environment using three different model scenarios (MAMPEC default, Baltic and OECD scenarios). The highest PEC of 57 ng l⁻¹, generated for a marina with the Baltic scenario, was at least 10,000-fold lower than the concentration that significantly decreased photosynthetic activity. It is concluded that medetomidine does not cause any acute toxic effects on bacterial protein synthesis and only small acute effects on photosynthesis at high concentrations in marine microbial communities. It is also concluded that the hazard from medetomidine on these processes is low since the effect levels are much lower than the highest PEC.

Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants.

PubMed

Desnoyers, M; Giger-Reverdin, S; Bertin, G; Duvaux-Ponter, C; Sauvant, D

2009-04-01

The effects of yeast supplementation on intake, production, and rumen fermentation characteristics have been widely studied, but results are inconsistent between different studies. A quantitative meta-analysis was applied to 110 papers, 157 experiments, and 376 treatments dealing with yeast supplementation in ruminants. The objective was first to highlight the major quantitative effects of live yeast supplementation on intake, rumen fermentation, and milk production, and second, to identify major differences in experimental conditions between studies that can affect the response to treatment. Some of these experimental conditions are referred to as interfering factors. Yeast supplementation increased rumen pH (+0.03 on average) and rumen volatile fatty acid concentration (+2.17 mM on average), tended to decrease rumen lactic acid concentration (-0.9 mM on average), and had no influence on acetate-to-propionate ratio. Total-tract organic matter digestibility was also increased by yeast supplementation (+0.8% on average). Yeast supplementation increased dry matter intake (DMI; +0.44 g/kg of body weight; BW), milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%), but had no influence on milk protein content. Dose effects of yeast supplementation, expressed as log(10) [1+(cfu per 100 kg of BW)], globally confirmed the qualitative effects observed in the first analysis. The positive effect of yeast supplementation on rumen pH increased with the percentage of concentrate in the diet and with the DMI level. It was negatively correlated with the level of dietary neutral detergent fiber (NDF). The positive effect of yeast supplementation on rumen volatile fatty acid concentration increased with DMI and crude protein levels. The positive effect of yeast supplementation on organic matter digestibility increased with the percentage of concentrate and NDF in the diet. The negative effect of yeast supplementation on lactic acid concentration tended to decrease when the DMI level and the percentage of concentrate in the diet increased. The effects of interfering factors were globally similar when either dose effect or qualitative effect of yeast was taken into account. Although rumen fermentation efficiency per se was not measured, these results suggest an improvement in rumen fermentation by yeast supplementation. This effect could, however, be modulated by several different factors such as DMI, percentage of concentrate or NDF in the diet, or species.

Nonequilibrium Concentration Fluctuations in Binary Liquid Systems Induced by the Soret Effect

NASA Astrophysics Data System (ADS)

Sengers, Jan V.; Ortiz de Zárate, José M.

When a binary liquid system is brought into a stationary thermal nonequilibrium state by the imposition of a temperature gradient, the Soret effect induces long-range concentration fluctuations even in the absence of any convective instability. The physical origin of the nonequilibrium concentration fluctuations is elucidated and it is shown how the intensity of these concentration fluctuations can be derived from the linearized random Boussinesq equations. Relevant experimental inform ation is also discussed.

Control of exogenous factors affecting plasma homovanillic acid concentration.

PubMed

Davidson, M; Giordani, A B; Mohs, R C; Mykytyn, V V; Platt, S; Aryan, Z S; Davis, K L

1987-04-01

Measurements of plasma homovanillic acid (pHVA) concentrations appear to be a valid research strategy in psychiatric disorders in which a central dopamine (DA) abnormality has been implicated. This study provides guidance about the control of some of the exogenous factors affecting pHVA concentrations. Fasting for 14 hours eliminates the dietary effects on pHVA in healthy human subjects. Changing position, walking for 30 minutes, or smoking two cigarettes has no effect on pHVA concentrations.

Noninvasive imaging of absolute PpIX concentration distribution in nonmelanoma skin tumors at pre-PDT

NASA Astrophysics Data System (ADS)

Sunar, Ulas; Rohrbach, Daniel; Morgan, Janet; Zeitouni, Natalie

2013-03-01

Photodynamic Therapy (PDT) has proven to be an effective treatment option for nonmelanoma skin cancers. The ability to quantify the concentration of drug in the treated area is crucial for effective treatment planning as well as predicting outcomes. We utilized spatial frequency domain imaging for quantifying the accurate concentration of protoporphyrin IX (PpIX) in phantoms and in vivo. We correct fluorescence against the effects of native tissue absorption and scattering parameters. First we quantified the absorption and scattering of the tissue non-invasively. Then, we corrected raw fluorescence signal by compensating for optical properties to get the absolute drug concentration. After phantom experiments, we used basal cell carcinoma (BCC) model in Gli mice to determine optical properties and drug concentration in vivo at pre-PDT.

Size Changes in Honey Bee Larvae Oenocytes Induced by Exposure to Paraquat at Very Low Concentrations

PubMed Central

Cousin, Marianne; Silva-Zacarin, Elaine; Kretzschmar, André; El Maataoui, Mohamed; Brunet, Jean-Luc; Belzunces, Luc P.

2013-01-01

The effects of the herbicide Paraquat were investigated in honey bee larvae with attention focused on oenocytes. Honey bee larvae were exposed to Paraquat at different concentrations in the food: 0, 0.001, 0.01, 0.1 and 1 µg/kg. In controls, between 24 h and 48 h, oenocytes grew from 630.1 to 1643.8 µm2 while nuclei changed in size from 124.9 to 245.6 µm2. At 24 h, Paraquat induced a slight decrease in the size of oenocytes and nuclei. N-acetylcysteine (NAC), an antioxidant substance, slightly lowered the effects of Paraquat. At 48 h, Paraquat elicited a strong concentration-dependent decrease in the size of oenocytes, even at the lowest concentration. NAC reversed the effect of Paraquat at a concentration of ≥0.01 µg/kg. This reversion suggested different modes of action of Paraquat, with an oxidant action prevalent at concentrations ≥0.01 µg/kg. This study is the first which reports an effect of a pesticide at the very low concentration of 1 ng/kg, a concentration below the detection limits of the most efficient analytic methods. It shows that chemicals, including pesticides, are likely to have a potential impact at such exposure levels. We also suggest that Paraquat could be used as a suitable tool for investigating the functions of oenocytes. PMID:23724149

Effects of tannin source and concentration from tree leaves on two species of tadpoles.

PubMed

Earl, Julia E; Semlitsch, Raymond D

2015-01-01

Vegetation in and around freshwater ecosystems can affect aquatic organisms through the production of secondary compounds, which are retained in leaves after senescence and are biologically active. Tannins can be toxic to tadpoles, but the plant source of tannins and tannin concentration have been confounded in experimental designs in previous studies. To examine the effects of the concentration and source of tannins (tree species), we examined the effects of 4 factors on tadpole survival, growth, and development: tannin source (red oak [Quercus rubra], white oak [Quercus alba], or sugar maple [Acer saccharum]); tannin concentration (including a control); diet protein level; and tadpole species (American toad [Anaxyrus americanus] and spring peepers [Pseudacris crucifer]). Tannin source and concentration affected spring peeper survival, but American toads had uniformly high survival. Spring peepers had a lower survival rate in high tannin concentrations of oak leachate but a high survival rate in both concentrations of sugar maple leachate. These differences in survival did not correspond with changes in dissolved oxygen, and no effect of dietary protein level on tadpole performance was observed. The presence of plant leachate resulted in increased tadpole growth in both species, but the mechanism for this finding is unclear. The results of the present study show that tannin concentration and source are important factors for tadpole performance, adding further evidence that plant chemistry can affect aquatic organisms. © 2014 SETAC.

Effects of hydrotreated vegetable oil on emissions of aerosols and gases from light-duty and medium-duty older technology engines.

PubMed

Bugarski, Aleksandar D; Hummer, Jon A; Vanderslice, Shawn

2016-01-01

This study was conducted to assess the potential of hydrotreated vegetable oil renewable diesel (HVORD) as a control strategy to reduce exposure of workers to diesel aerosols and gases. The effects of HVORD on criteria aerosol and gaseous emissions were compared with those of ultralow sulfur diesel (ULSD). The results of comprehensive testing at four steady-state conditions and one transient cycle were used to characterize the aerosol and gaseous emissions from two older technology engines: (1) a naturally aspirated mechanically controlled and (2) a turbocharged electronically controlled engine. Both engines were equipped with diesel oxidation catalytic converters (DOCs). For all test conditions, both engines emitted measurably lower total mass concentrations of diesel aerosols, total carbon, and elemental carbon when HVORD was used in place of ULSD. For all test conditions, the reductions in total mass concentrations were more substantial for the naturally aspirated than for the turbocharged engine. In the case of the naturally aspirated engine, HVORD also favorably affected total surface area of aerosols deposited in the alveolar region of human lungs (TSAADAR) and the total number concentrations of aerosols. In the case of the turbocharged electronically controlled engine, for some of the test conditions HVORD adversely affected the TSAADAR and total number concentrations of aerosols. In the majority of the test cases involving the naturally aspirated mechanically controlled engine, HVORD favorably affected carbon dioxide (CO2), nitrogen oxides (NOX), and nitric oxide (NO) concentrations, but adversely affected NO2 and total hydrocarbon concentrations, while the effects of the fuels on carbon monoxide (CO) concentrations were masked by the effects of DOC. In the case of the turbocharged electronically controlled engine, the CO2, CO, NOX, NO, and total hydrocarbon concentrations were generally lower when HVORD was used in place of ULSD. The effects of the fuels on NO2 concentrations were masked by the more prominent effects of DOC.

Effects of hydrotreated vegetable oil on emissions of aerosols and gases from light-duty andmedium-duty older technology engines

PubMed Central

Bugarski, Aleksandar D.; Hummer, Jon A.; Vanderslice, Shawn

2017-01-01

This study was conducted to assess the potential of hydrotreated vegetable oil renewable diesel (HVORD) as a control strategy to reduce exposure of workers to diesel aerosols and gases. The effects of HVORD on criteria aerosol and gaseous emissions were compared with those of ultralow sulfur diesel (ULSD). The results of comprehensive testing at four steady-state conditions and one transient cycle were used to characterize the aerosol and gaseous emissions from two older technology engines: (1) a naturally aspirated mechanically controlled and (2) a turbocharged electronically controlled engine. Both engines were equipped with diesel oxidation catalytic converters (DOCs). For all test conditions, both engines emitted measurably lower total mass concentrations of diesel aerosols, total carbon, and elemental carbon when HVORD was used in place of ULSD. For all test conditions, the reductions in total mass concentrations were more substantial for the naturally aspirated than for the turbocharged engine. In the case of the naturally aspirated engine, HVORD also favorably affected total surface area of aerosols deposited in the alveolar region of human lungs (TSAADAR) and the total number concentrations of aerosols. In the case of the turbocharged electronically controlled engine, for some of the test conditions HVORD adversely affected the TSAADAR and total number concentrations of aerosols. In the majority of the test cases involving the naturally aspirated mechanically controlled engine, HVORD favorably affected carbon dioxide (CO2), nitrogen oxides (NOX), and nitric oxide (NO) concentrations, but adversely affected NO2 and total hydrocarbon concentrations, while the effects of the fuels on carbon monoxide (CO) concentrations were masked by the effects of DOC. In the case of the turbocharged electronically controlled engine, the CO2, CO, NOX, NO, and total hydrocarbon concentrations were generally lower when HVORD was used in place of ULSD. The effects of the fuels on NO2 concentrations were masked by the more prominent effects of DOC. PMID:26588029

Effects of Oral Glucosamine Hydrochloride Administration on Plasma Free Amino Acid Concentrations in Dogs

PubMed Central

Azuma, Kazuo; Osaki, Tomohiro; Tsuka, Takeshi; Imagawa, Tomohiro; Okamoto, Yoshiharu; Takamori, Yoshimori; Minami, Saburo

2011-01-01

We examined the effects of oral glucosamine hydrochloride (GlcN), N-acetyl-d-glucosamine (GlcNAc) and d-glucose (Glc) administration on plasma total free amino acid (PFAA) concentrations in dogs. The PFAA concentrations increased in the control group and the GlcNAc group at one hour after feeding, and each amino acid concentration increased. On the other hand, in the GlcN group and the Glc group PFAA concentrations decreased at one hour after feeding. A significant decrease in amino acid concentration was observed for glutamate, glycine and alanine. Our results suggest the existence of differences in PFAA dynamics after oral administration of GlcN and GlcNAc in dogs. PMID:21673884

Characterizing toxicity of metal-contaminated sediments from mining areas

USGS Publications Warehouse

Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

2015-01-01

This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate communities can help document causal relationships between metal contamination and biological effects. Total or total-recoverable metal concentrations in sediments are the most common measure of metal contamination in sediments, but metal concentrations in labile sediment fractions (e.g., determined as part of selective sediment extraction protocols) may better represent metal bioavailability. Metals released by the weak-acid extraction of acid-volatile sulfide (AVS), termed simultaneously-extracted metals (SEM), are widely used to estimate the ‘potentially-bioavailable’ fraction of metals that is not bound to sulfides (i.e., SEM-AVS). Metal concentrations in pore water are widely considered to be direct measures of metal bioavailability, and predictions of toxicity based on pore-water metal concentrations may be further improved by modeling interactions of metals with other pore-water constituents using Biotic Ligand Models. Data from sediment toxicity tests and metal analyses has provided the basis for development of sediment quality guidelines, which estimate thresholds for toxicity of metals in sediments. Empirical guidelines such as Probable Effects Concentrations or (PECs) are based on associations between sediment metal concentrations and occurrence of toxic effects in large datasets. PECs do not model bioavailable metals, but they can be used to estimate the toxicity of metal mixtures using by calculation of probable effect quotients (PEQ = sediment metal concentration/PEC). In contrast, mechanistic guidelines, such as Equilibrium Partitioning Sediment Benchmarks (ESBs) attempt to predict both bioavailability and mixture toxicity. Application of these simple bioavailability models requires more extensive chemical characterization of sediments or pore water, compared to empirical guidelines, but may provide more reliable estimates of metal toxicity across a wide range of sediment types.

Measuring near-field nanoparticle concentration profiles by correlating surface plasmon resonance reflectance with effective refractive index of nanofluids.

PubMed

Kim, Iltai; Kihm, Kenneth D

2010-02-01

Time-dependent and near-field nanoparticle concentrations are determined by correlating the surface plasmon resonance (SPR) reflectance intensities with the effective refractive index (ERI) of the nanofluid under evaporation. A critical angle measurement for total internal reflection identifies the ERI of the nanofluid at different nanoparticle concentrations. The corresponding SPR reflectance intensities correlate the nanofluidic ERI with the nanoparticle concentrations. Example applications for evaporating nanofluidic droplets containing 47 nmAl(2)O(3) particles demonstrate the feasibility of this new imaging tool for measuring time-resolved and full-field nanoparticle concentration profiles.

The effect of pulping concentration treatment on the properties of microcrystalline cellulose powder obtained from waste paper.

PubMed

Okwonna, Okumneme O

2013-10-15

Microcrystalline cellulose (MCC) powder was isolated from three grades of waste paper: book, Groundwood/Newsprint and paperboard, through the processes of pulping and hydrolysis. Pulping treatment on these grades of waste paper was done using varying concentrations of caustic soda. Effects of the concentration of the pulping medium on the thermal and kinetic properties were investigated. Also determined were the effects of this on the physico-chemical properties. The chemical structure was characterized using an infrared spectroscopy (FTIR). Results showed these properties to be affected by the concentration of the pulping medium. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of proteinase 3 (PR3) by suramin and fetal calf serum (FCS): effect of PR3 and suramin on Chinese hamster ovary cells (CHO-cells).

PubMed

Karam, Gholamreza Asadi; Rasaee, Mohammad Javad; Mahmoodi, Mehdi; Khaksari, Mohammad

2005-07-01

Proteinase 3 (PR3) is a lysosomal protease that is stored in azurophilic granules neutrophilic granulocytes and monocytes. A number of inhibitors for this proteinase are reported. Comprehensive studies on the inhibitory effect of suramin and heat treated fetal calf serum (deltaFCS) on PR3 have not been reported. It has been reported that PR3 is able to destroy the cytoskeletal integral proteins, but we have not find any reports which showed the effect of this protease on Chinese hamster ovary cells (CHO-cells) in culture medium. Suramin has proven to be useful as an antitumor drug, but there was not any report on the effect of suramin on CHO-cells. The effects of various concentrations of deltaFCS (from 0.5% up to 10%) and suramin (from 0.8 microM up to 100 microM) on PR3 and different concentrations of suramin (from 0.8 microM up to 1000 microM) on CHO-cells were investigated. Data analysis were performed by, Kolmogorov-Smirnov test, ANOVA test and Tukey HSD post tests. Results showed that deltaFCS and suramin have an inhibitory effect on PR3 and these effects increased with increasing the concentration significantly (p < 0.01). PR3 with the concentration of 2.2 Unit/ml has no effect on CHO-cells. Although suramin with the concentration of less than 125 microM cell growth retarded for only a few hours, but with the concentration of 125 to 250 microM inhibit the cell growth for a week, and after that cells gain normal growth gradually. Suramin with concentration of more than 500 microM inhibited the cell growth completely. Although suramin reversibly inhibit the PR3 activity but in concentration of less than 250 microM it had no long-term effect on CHO-cells. Therefore it can be used in the investigation of proteases. There were unknown components in deltaFCS, which cause the inhibition of PR3 activity. This finding is very important in PR3 production in culture medium. However CHO-cells are resistant to PR3 and suramin in low concentration.

Suitable Concentrations of Uric Acid Can Reduce Cell Death in Models of OGD and Cerebral Ischemia-Reperfusion Injury.

PubMed

Zhang, Bin; Yang, Ning; Lin, Shao-Peng; Zhang, Feng

2017-07-01

Cerebral infarction (CI) is a common clinical cerebrovascular disease, and to explore the pathophysiological mechanisms and seek effective treatment means are the hotspot and difficult point in medical research nowadays. Numerous studies have confirmed that uric acid plays an important role in CI, but the mechanism has not yet been clarified. When treating HT22 and BV-2 cells with different concentrations of uric acid, uric acid below 450 μM does not have significant effect on cell viability, but uric acid more than 500 μM can significantly inhibit cell viability. After establishing models of OGD (oxygen-glucose deprivation) with HT22 and BV-2 cells, uric acid at a low concentration (50 μM) cannot improve cell viability and apoptosis, and Reactive oxygen species (ROS) levels during OGD/reoxygenation; a suitable concentration (300 μM) of uric acid can significantly improve cell viability and apoptosis, and reduce ROS production during OGD/reoxygenation; but a high concentration (1000 μM) of uric acid can further reduce cell viability and enhance ROS production. After establishing middle cerebral artery occlusion of male rats with suture method, damage and increase of ROS production in brain tissue could be seen, and after adding suitable concentration of uric acid, the degree of brain damage and ROS production was reduced. Therefore, different concentrations of uric acid should have different effect, and suitable concentrations of uric acid have neuroprotective effect, and this finding may provide guidance for study on the clinical curative effect of uric acid.

The effect of feed supplementation with effective microorganisms (EM) on pro- and anti-inflammatory cytokine concentrations in pigs.

PubMed

Laskowska, Ewa; Jarosz, Łukasz; Grądzki, Zbigniew

2017-12-01

Effective microorganisms (EM) are used in numerous fields associated with agriculture. The beneficial effects of EM on the general health of pigs and on production parameters are also determined by the influence of these microbes on immunity. The aim of the study was to assess the effect of feed supplementation with EM on the concentration of pro- and anti-inflammatory cytokines in the serum and in a culture of PBMCs with and without ConA stimulation in pigs. ELISA kits were used to determine the cytokine levels in the porcine serum and the PBMC culture supernatants. Evaluation of the serum concentration of cytokines revealed statistically significantly higher concentrations of IL-2, IL-4, IL-10, IFN-γ and TNF-α in the pigs receiving EM Bokashi. The highest concentration of TGF-β in the experimental group was noted on the final test day. Evaluation of cytokine concentrations in the PBMC cultures revealed statistically significantly higher concentrations of IL-2, IL-4 and IL-10 from the third day of the experiment. Statistically significantly higher concentrations of TNF-α were obtained in the unstimulated PBMC culture on the second test day and in the culture treated with ConA on the second and the third test days. The results of our study indicate that supplementation of pig feed with EM Bokashi activates the cell-mediated and humoral immune response, ensuring that Th1/Th2 balance is maintained and enhancing immune processes protecting the body against infection. Copyright © 2017. Published by Elsevier Ltd.

[Low-dose desmopressin (DDAVP) and blood levels of FSH, LH and testosterone in men].

PubMed

García-Pascual, I J; Rozán Flores, M A

1996-03-01

The effect of desmopressin (DDAVP) administration (2.5 micrograms/12 hours) on serum concentrations of FSH, LH and testosterone was studied in six men. No significant changes were observed in serum concentrations of FSH and LH after 9 days with DDAVP therapy. Nevertheless, serum concentrations of testosterone after 12 hours of DDAVP administration were significantly higher than basal concentrations. Three hours after the administration of DDAVP, serum testosterone concentrations decreased significantly. The conclusion reached was that low doses of desmopressin do not change serum concentrations of FSH and LH, but serum concentration of testosterone is decreased within three hours after the administration, although an increase is observed 12 hours later possibly due to a "rebound effect". Desmopressin would therefore directly act upon human testicle.

Effects of future climate change, CO2 enrichment, and vegetation structure variation on hydrological processes in China

USGS Publications Warehouse

Zhu, Qiuan; Jiang, Hong; Peng, Changhui; Liu, Jinxun; Fang, Xiuqin; Wei, Xiaohua; Liu, Shirong; Zhou, Guomo

2012-01-01

Investigating the relationship between factors (climate change, atmospheric CO2 concentrations enrichment, and vegetation structure) and hydrological processes is important for understanding and predicting the interaction between the hydrosphere and biosphere. The Integrated Biosphere Simulator (IBIS) was used to evaluate the effects of climate change, rising CO2, and vegetation structure on hydrological processes in China at the end of the 21st century. Seven simulations were implemented using the assemblage of the IPCC climate and CO2 concentration scenarios, SRES A2 and SRES B1. Analysis results suggest that (1) climate change will have increasing effects on runoff, evapotranspiration (ET), transpiration (T), and transpiration ratio (transpiration/evapotranspiration, T/E) in most hydrological regions of China except in the southernmost regions; (2) elevated CO2 concentrations will have increasing effects on runoff at the national scale, but at the hydrological region scale, the physiology effects induced by elevated CO2 concentration will depend on the vegetation types, climate conditions, and geographical background information with noticeable decreasing effects shown in the arid Inland region of China; (3) leaf area index (LAI) compensation effect and stomatal closure effect are the dominant factors on runoff in the arid Inland region and southern moist hydrological regions, respectively; (4) the magnitudes of climate change (especially the changing precipitation pattern) effects on the water cycle are much larger than those of the elevated CO2 concentration effects; however, increasing CO2 concentration will be one of the most important modifiers to the water cycle; (5) the water resource condition will be improved in northern China but depressed in southernmost China under the IPCC climate change scenarios, SRES A2 and SRES B1.

The effects of low and moderate doses of caffeine supplementation on upper and lower body maximal voluntary concentric and eccentric muscle force.

PubMed

Tallis, Jason; Yavuz, Harley C M

2018-03-01

Despite the growing quantity of literature exploring the effect of caffeine on muscular strength, there is a dearth of data that directly explores differences in erogenicity between upper and lower body musculature and the dose-response effect. The present study sought to investigate the effects of low and moderate doses of caffeine on the maximal voluntary strength of the elbow flexors and knee extensors. Ten nonspecifically strength-trained, recreationally active participants (aged 21 ± 0.3 years) completed the study. Using a randomised, counterbalanced, and double-blind approach, isokinetic concentric and eccentric strength was measured at 60 and 180°/s following administration of a placebo, 3 mg·kg -1 body mass caffeine, and 6 mg·kg -1 body mass caffeine. There was no effect of caffeine on the maximal voluntary concentric and eccentric strength of the elbow flexors, or the eccentric strength of the knee extensors. Both 3 and 6 mg·kg -1 body mass caffeine caused a significant increase in peak concentric force of the knee extensors at 180°/s. No difference was apparent between the 2 concentrations. Only 6 mg·kg -1 body mass caused an increase in peak concentric force during repeated contractions. The results infer that the effective caffeine concentration to evoke improved muscle performance may be related to muscle mass and contraction type. The present work indicates that a relatively low dose of caffeine treatment may be effective for improving lower body muscular strength, but may have little benefit for the strength of major muscular groups of the upper body.

Effect of simultaneous variation in temperature and ammonia concentration on percent fertilization and hatching in Crassostrea ariakensis.

PubMed

Hui, Wang; Jiahui, Liu; Hongshuai, Yang; Jin, Liu; Zhigang, Liu

2014-04-01

The combined effects of temperature and ammonia concentration on the percent fertilization and percent hatching in Crassostrea ariakensis were examined under laboratory conditions using the central composite design and response surface methodology. The results indicated: (1) The linear effects of temperature and ammonia concentration on the percent fertilization were significant (P<0.05), and the quadratic effects were highly significant (P<0.01). The interactive effect between temperature and ammonia concentration on the percent fertilization was not significant (P>0.05). (2) The linear effect of temperature on the percent hatching was highly significant (P<0.01), and that of ammonia concentration was nonsignificant (P>0.05). The quadratic effects of temperature and ammonia concentration on the percent hatching were highly significant (P<0.01). The interaction on the percent hatching was not significant (P>0.05). Temperature was more important than ammonia in influencing the fertilization and hatching in C. ariakensis. (3) The model equations of the percent fertilization and hatching towards temperature and ammonia concentration were established, with the coefficients of determination R(2)=99.4% and 99.76%, respectively. Through the lack-of-fit test, these models were of great adequacy. The predictive coefficients of determination for the two model equations were as high as 94.6% and 98.03%, respectively, showing that they could be used for practical projection. (4) Via the statistical simultaneous optimization technique, the optimal factor level combination, i.e., 25°C/0.038mgmL(-1), was derived, at which the greatest percent fertilization 95.25% and hatching 83.26% was achieved, with the desirability being 97.81%. Our results may provide advantageous guidelines for the successful reproduction of C. ariakensis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Subsequent bone and metabolic responses of broilers to high-non-phytate phosphorus diets in the starter period.

PubMed

Baradaran, N; Shahir, M H; Asadi Kermani, Z

2017-08-01

1. An experiment was performed to elucidate the subsequent effects of high-non-phytate phosphorus (NPP) diets on growth performance, blood metabolites, bone characteristics and P retention of broilers fed on low-NPP grower diets. The 42-d study was designed as a 2 × 2 × 2 + 1 factorial, which included two starter NPP concentrations (4.5 and 5.5 g/kg; d 0-21), two grower NPP concentrations (1.5 and 2.3 g/kg; d 22-42), with or without phytase (1000 FTU/kg), with a reference diet containing an adequate NPP concentration over the course of the trial. 2. In the starter period, growth performance and P retention were not affected by experimental diets. The high-NPP diet increased plasma P concentration, increased tibia ash and tibia P contents and decreased plasma alkaline phosphatase (ALP) activity at d 21. 3. No significant interaction was observed between NPP concentrations in the starter and grower periods and phytase. The main effect data indicated that the increase in NPP concentration in the starter diets had no effects on growth performance in the grower period and overall. The high-NPP diet in the early stage of growth reduced plasma P concentration, plasma ALP activity and tibia ash content at d 42. The main effect data also showed that exogenous phytase increased body weight gain in the grower period and overall. 4. It can be concluded that feeding increased NPP diets have no effects on growth performance in the starter period. This feeding strategy results in negative effects on plasma P concentration and bone ash content at d 42. Also, exogenous phytase is effective in improving growth performance, bone characteristics and apparent P retention of growing broilers fed diets that are inadequate in phosphorus.

29 CFR 1910.1017 - Vinyl chloride.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

29 CFR 1910.1017 - Vinyl chloride.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

29 CFR 1910.1017 - Vinyl chloride.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

Enhanced Forced Convection Heat Transfer using Small Scale Vorticity Concentrations Effected by Flow Driven, Aeroelastically Vibrating Reeds

DTIC Science & Technology

2016-08-03

insulated from behind (using an air gap) as shown in figure III.3-1c. Each of the heated side walls are instrumented with seven equally-spaced T-Type...AFRL-AFOSR-VA-TR-2016-0339 Enhanced convection heat transfer using small-scale vorticity concentrations effected by flow-driven, aeroelastically...public release. Enhanced Forced Convection Heat Transfer using Small-Scale Vorticity Concentrations Effected by Flow-Driven, Aeroelastically Vibrating

The Effects of Scavenging on Waste Methoxyflurane Concentrations in Veterinary Operating Room Air

DTIC Science & Technology

1981-01-01

Afl-AO5 572 AIR FORCE OCCUPATIONAL AND ENVIRONMENTAL H4EALTH LAS -ETC F/S 6120 TIE EFFECTS OF SCAVENGING ON WASTE METHOXYFLURANE CONCENTRATIOH-ETC...REPRINT The Effects of Scavenging on Waste Methoxyflurane Concentrations in Veterinary Operating Room Air Approved for public release; distribution...Waste Methoxyflurane Fnal y t Concentrations ir Veterinary Operating Room Air, 6.PROMN _6._PERFORMIN oIG. REPORT NUMBER 7. AUTOR~s)B. CONTRACT OR GRANT

Circumpolar contaminant concentrations in polar bears (Ursus maritimus) and potential population-level effects.

PubMed

Nuijten, R J M; Hendriks, A J; Jenssen, B M; Schipper, A M

2016-11-01

Polar bears (Ursus maritimus) currently receive much attention in the context of global climate change. However, there are other stressors that might threaten the viability of polar bear populations as well, such as exposure to anthropogenic pollutants. Lipophilic organic compounds bio-accumulate and bio-magnify in the food chain, leading to high concentrations at the level of top-predators. In Arctic wildlife, including the polar bear, various adverse health effects have been related to internal concentrations of commercially used anthropogenic chemicals like PCB and DDT. The extent to which these individual health effects are associated to population-level effects is, however, unknown. In this study we assembled data on adipose tissue concentrations of ∑PCB, ∑DDT, dieldrin and ∑PBDE in individual polar bears from peer-reviewed scientific literature. Data were available for 14 out of the 19 subpopulations. We found that internal concentrations of these contaminants exceed threshold values for adverse individual health effects in several subpopulations. In an exploratory regression analysis we identified a clear negative correlation between polar bear population density and sub-population specific contaminant concentrations in adipose tissue. The results suggest that adverse health effects of contaminants in individual polar bears may scale up to population-level consequences. Our study highlights the need to consider contaminant exposure along with other threats in polar bear population viability analyses. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative evaluation of effectiveness of sodium dichloroisocyanurate and calcium hydroxide against Candida albicans.

PubMed

Kurian, Jacob; Bolla, Nagesh; Damaraju, Bhargavi

2012-09-01

Candida albicans is the most commonly isolated fungi from the oral cavity. It is the most infective to various intracanal medicaments and is considered as invasive yeast. Sodium dichloroisocyanurate (NaDCC) which is used as a disinfectant and as a biocide in treating potable water has similar action to that of sodium hypochlorite against microbes. The aim of the present study is to compare the effectiveness of calcium hydroxide and NaDCC against Candida albicans. After obtaining the stock cultures of Candida, the isolates were divided into six groups which were exposed to different concentrations of NaDCC and calcium hydroxide Ca(OH)₂. Group 1 consisted of the isolates which were subdivided into three groups, subjected to three different concentrations of NaDCC. Group 2 also consisted of three subgroups exposed to three different concentrations of Ca(OH)₂. Group three consisted of three subgroups which were exposed to three different concentrations of combinations of both NaDCC and Ca(OH)₂. The results of the present study show that calcium hydroxide was totally ineffective at all concentrations and NaDCC was effective and also the combination of both was shown to be effective. NaDCC alone was effective at all concentrations and the combination with Ca(OH)₂ was found to be less effective. Ca(OH)₂ was totally ineffective.

The Statistical Value of Raw Fluorescence Signal in Luminex xMAP Based Multiplex Immunoassays

PubMed Central

Breen, Edmond J.; Tan, Woei; Khan, Alamgir

2016-01-01

Tissue samples (plasma, saliva, serum or urine) from 169 patients classified as either normal or having one of seven possible diseases are analysed across three 96-well plates for the presences of 37 analytes using cytokine inflammation multiplexed immunoassay panels. Censoring for concentration data caused problems for analysis of the low abundant analytes. Using fluorescence analysis over concentration based analysis allowed analysis of these low abundant analytes. Mixed-effects analysis on the resulting fluorescence and concentration responses reveals a combination of censoring and mapping the fluorescence responses to concentration values, through a 5PL curve, changed observed analyte concentrations. Simulation verifies this, by showing a dependence on the mean florescence response and its distribution on the observed analyte concentration levels. Differences from normality, in the fluorescence responses, can lead to differences in concentration estimates and unreliable probabilities for treatment effects. It is seen that when fluorescence responses are normally distributed, probabilities of treatment effects for fluorescence based t-tests has greater statistical power than the same probabilities from concentration based t-tests. We add evidence that the fluorescence response, unlike concentration values, doesn’t require censoring and we show with respect to differential analysis on the fluorescence responses that background correction is not required. PMID:27243383

[Selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalysts].

PubMed

Sun, Hong; Quan, Xie; Zhang, Yao-bin; Zhao, Ya-zhi

2008-06-01

Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst was prepared by sol-gel and impregnation. Furthermore, selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst with propylene under lean burn condition was studied. The effects of the concentration of tetra-n-butyl titanate and dipcoat cycles on TiO2 washcoat were studied by SEM, and the effects of Pd concentration, O2 concentration and gas velocity on catalytic activity were investigated. The experimental results showed that the TiO2 washcoat on wire-mesh support is even and crack-free when the support is impregnated in 20.0% tetra- n-butyl titanate sol for 2 cycles. The NOx conversion decreases with Pd concentration increase. When Pd concentration is 0.23%, NOx conversion is highest. NOx conversion increases with oxygen concentration increase in the range of 1.5%-6.0%. However, when oxygen concentration is higher than 6.0%, NOx conversion decreases with increasing oxygen concentration. The NOx conversion decreases with gas velocity increase and its effect is severer at high temperature than low temperature.

Is lowering reducing sugars concentration in French fries an effective measure to reduce acrylamide concentration in food service establishments?

PubMed

Sanny, M; Jinap, S; Bakker, E J; van Boekel, M A J S; Luning, P A

2012-12-01

The objective of this study was to obtain insight into the actual effectiveness of lowering reducing sugars concentration in par-fried potato strips on the concentration and variation of acrylamide in French fries prepared in real-life situations in food service establishments. Acrylamide, frying time, frying temperature, and reducing sugars were measured and characteristics of fryers were recorded. Data showed that the use of par-fried potato strips with lower concentrations of reducing sugars than the commonly used potato strips was an effective measure to reduce acrylamide concentrations in French fries prepared under standardised frying conditions. However, there was still large variation in the acrylamide concentrations in French fries, although the variation in reducing sugars concentrations in low and normal types of par-fried potato strips was very small and the frying conditions were similar. Factors that could affect the temperature-time profile of frying oil were discussed, such as setting a lower frying temperature at the end than at the start of frying, product/oil ratio and thawing practice. These need to be controlled in daily practice to reduce variation in acrylamide. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of reflection losses on stationary dielectric-filled nonimaging concentrators

NASA Astrophysics Data System (ADS)

Madala, Srikanth; Boehm, Robert F.

2016-10-01

The effect of Fresnel reflection and total internal reflection (TIR) losses on the performance parameters in refractive solar concentrators has often been downplayed because most refractive solar concentrators are traditionally the imaging type, yielding a line or point image on the absorber surface when solely interacted with paraxial etendue ensured by solar tracking. Whereas, with refractive-type nonimaging solar concentrators that achieve two-dimensional (rectangular strip) focus or three-dimensional (circular or elliptical) focus through interaction with both paraxial and nonparaxial etendue within the acceptance angle, the Fresnel reflection and TIR losses are significant as they will affect the performance parameters and, thereby, energy collection. A raytracing analysis has been carried out to illustrate the effects of Fresnel reflection and TIR losses on four different types of stationary dielectric-filled nonimaging concentrators, namely V-trough, compound parabolic concentrator, compound elliptical concentrator, and compound hyperbolic concentrator. The refractive index (RI) of a dielectric fill material determines the acceptance angle of a solid nonimaging collector. Larger refractive indices yield larger acceptance angles and, thereby, larger energy collection. However, they also increase the Fresnel reflection losses. This paper also assesses the relative benefit of increasing RI from an energy collection standpoint.

Asymmetric inner wedge group sequential tests with applications to verifying whether effective drug concentrations are similar in adults and children.

PubMed

Hampson, Lisa V; Fisch, Roland; Van, Linh M; Jaki, Thomas

2017-02-10

Extrapolating from information available on one patient group to support conclusions about another is common in clinical research. For example, the findings of clinical trials, often conducted in highly selective patient cohorts, are routinely extrapolated to wider populations by policy makers. Meanwhile, the results of adult trials may be used to support conclusions about the effects of a medicine in children. For example, if the effective concentration of a drug can be assumed to be similar in adults and children, an appropriate paediatric dosing rule may be found by 'bridging', that is, by matching the adult effective concentration. However, this strategy may result in children receiving an ineffective or hazardous dose if, in fact, effective concentrations differ between adults and children. When there is uncertainty about the equality of effective concentrations, some pharmacokinetic-pharmacodynamic data may be needed in children to verify that differences are small. In this paper, we derive optimal group sequential tests that can be used to verify this assumption efficiently. Asymmetric inner wedge tests are constructed that permit early stopping to accept or reject an assumption of similar effective drug concentrations in adults and children. Asymmetry arises because the consequences of under- and over-dosing may differ. We show how confidence intervals can be obtained on termination of these tests and illustrate the small sample operating characteristics of designs using simulation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

In vitro effects of flutriafol and azoxystrobin on Beauvaria bassiana and its efficacy against Tetranychus urticae.

PubMed

Gatarayiha, Mutimura C; Laing, Mark D; Miller, Ray M

2010-07-01

Testing the compatibility of chemical pesticides and fungal biocontrol agents is necessary if these two agents are to be applied together in the integrated management of plant pests and diseases. In this study, the fungicides azoxystrobin (a strobilurin) and flutriafol (a triazole) were tested in vitro for their effects on germination of conidia and mycelial growth of Beauveria bassiana (Bals.) Vuill. and in bioassay for their effect on fungal activity against Tetranychus urticae Koch. The fungicides were tested at three different concentrations [recommended rate for field use (1 x X) and the dilutions 10(-1)x X and 10(-2)x X]. Flutriafol inhibited growth of mycelia and germination of the fungal conidia at all concentrations tested in vitro, and also reduced the efficacy of B. bassiana in bioassays against mites. The inhibitive effect of azoxystrobin in vitro varied with the concentration applied. A significant effect was observed at 1 x X and 10(-1)x X concentrations on both the germination of conidia and mycelia growth. At 10(-2)x X concentration, azoxystrobin showed little effect on B. bassiana. However, when this fungicide was tested in bioassays, none of the concentrations reduced B. bassiana activity against mites. Azoxystrobin was most compatible with B. bassiana, while flutriafol was the most harmful. Further studies are required to confirm the negative effect of flutriafol on B. bassiana activity. Copyright (c) 2010 Society of Chemical Industry.

Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta)

PubMed Central

Goecke, Franz; Jerez, Celia G.; Zachleder, Vilém; Figueroa, Félix L.; Bišová, Kateřina; Řezanka, Tomáš; Vítová, Milada

2015-01-01

Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations. PMID:25674079

Curcumin as a potential non-steroidal contraceptive with spermicidal and microbicidal properties.

PubMed

Naz, R K; Lough, M L

2014-05-01

Curcumin, a component of the curry powder turmeric, has immense biological properties, including anticancer effects. The objective of this study was to determine if curcumin can provide a novel non-steroidal contraceptive having both spermicidal and microbicidal properties. The effect of curcumin, with and without photosensitization, was examined on human sperm forward motility and growth of several aerobic (n=8) and anaerobic bacteria (n=4) and yeast (n=7) strains implicated in vaginosis, vaginitis, and vaginal infections in women. The effect of various concentrations of curcumin on human sperm and microbes (aerobic and anaerobic bacteria and yeast) was tested. The effect on sperm was examined by counting the sperm forward motility, and on microbes by agar and broth dilutions and colony counting. Each experiment was repeated using different semen specimens, and bacteria and yeast stocks. Curcumin caused a concentration-dependent inhibition of sperm forward motility with a total block at ≥250μM concentration. After photosensitization, the effective concentration to completely block sperm forward motility decreased 25-fold, now requiring only 10μM concentration for total inhibition. Curcumin concentrations between 100 and 500μM completely blocked the growth of all the bacteria and yeast strains tested. After photosensitization, the effective concentration to completely inhibit microbial growth decreased 10-fold for aerobic bacteria and yeast, and 5-fold for anaerobic bacteria. These findings suggest that curcumin can block sperm function and bacteria/yeast growth. It can potentially provide an ideal non-steroidal contraceptive having both spermicidal and microbicidal properties against vaginal infections. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Interactive effects of temperature and glyphosate on the behavior of blue ridge two-lined salamanders (Eurycea wilderae).

PubMed

Gandhi, Jaina S; Cecala, Kristen K

2016-09-01

The objective of the present study was to evaluate the potential interactive effects of stream temperatures and environmentally relevant glyphosate-based herbicide concentrations on movement and antipredator behaviors of larval Eurycea wilderae (Blue Ridge two-lined salamander). Larval salamanders were exposed to 1 of 4 environmentally relevant glyphosate concentrations (0.00 µg acid equivalent [a.e.]/L, 0.73 µg a.e./L, 1.46 µg a.e./L, and 2.92 µg a.e./L) at either ambient (12 °C) or elevated (23 °C) water temperature. Behaviors observed included the exploration of a novel habitat, use of refuge, habitat selection relative to a potential predator, and burst movement distance. In the absence of glyphosate, temperature consistently affected movement and refuge-use behavior, with individuals moving longer distances more frequently and using refuge less at warm temperatures; however, when glyphosate was added, the authors observed inconsistent effects of temperature that may have resulted from differential toxicity at various temperatures. Larval salamanders made shorter, more frequent movements and demonstrated reduced burst distance at higher glyphosate concentrations. The authors also found that lower glyphosate concentrations sometimes had stronger effects than higher concentrations (i.e., nonmonotonic dose responses), suggesting that standard safety tests conducted only at higher glyphosate concentrations might overlook important sublethal effects on salamander behavior. These data demonstrate that sublethal effects of glyphosate-based herbicides on natural behaviors of amphibians can occur with short-term exposure to environmentally relevant concentrations. Environ Toxicol Chem 2016;35:2297-2303. © 2016 SETAC. © 2016 SETAC.

Ocimum basilicum affects tracheal responsiveness, lung inflammatory cells and oxidant-antioxidant biomarkers in sensitized rats.

PubMed

Eftekhar, Naeima; Moghimi, Ali; Hossein Boskabady, Mohammad; Kaveh, Mahsa; Shakeri, Farzaneh

2018-04-23

The anti-inflammatory and antioxidant effects of Ocimum basilicum (O. basilicum) was shown previously. In the present study, the effect of O. basilicum on tracheal responsiveness (TR) to methacholine and ovalbumin (OVA), bronchoalveolar lavage fluid (BALF) levels of oxidant-antioxidant biomarkers as well as total and differential white blood cell (WBC) in sensitized rats was examined. Six groups of rats including control (group C), sensitized rats to OVA (group S), S groups treated with three concentrations of O. basilicum (0.75, 1.50, and 3.00 mg/ml) and one concentration of dexamethasone (1.25 μg/ml) (n = 8 for all groups) were studied. TR to methacholine and OVA, total WBC count, percentages of eosinophils, monocytes, neutrophils, and levels of oxidant biomarkers were significantly increased but other measured parameters were significantly decreased in group S compared to group C. TR to methacholine and OVA, percentages of eosinophils, monocytes, neutrophils, and levels of oxidant biomarkers were significantly decreased but lymphocytes and antioxidant biomarkers were significantly increased in S groups treated with dexamethasone and at least two higher concentrations of the extract compared to group S. Total WBC count was also decreased in treated S groups with dexamethasone and high extract concentration. The effect of extract on most measured parameters was significantly lower than dexamethasone treatment. The effects of two higher concentrations of the extract on most variables were significantly higher than the effect of low extract concentration. These results showed the concentration-dependent effect of O. basilicum on tracheal responses, lung inflammatory cells, and oxidant-antioxidant parameters in sensitized rats.

Assessment of combinations of antiandrogenic compounds vinclozolin and flutamide in a yeast based reporter assay.

PubMed

Kolle, Susanne N; Melching-Kollmuss, Stephanie; Krennrich, Gerhard; Landsiedel, Robert; van Ravenzwaay, Bennard

2011-08-01

Humans are exposed to a combination of various substances such as cosmetic ingredients, drugs, biocides, pesticides and natural-occurring substances in food. The combined toxicological effects of two or more substances can simply be additive on the basis of response-addition, or it can be greater (synergistic) or smaller (antagonistic) than this. The need to assess combined effects of compounds with endocrine activity is currently discussed for regulatory risk assessment. We have used a well described yeast based androgen receptor transactivation assay YAS to assess the combinatorial effects of vinclozolin and flutamide; both mediating antiandrogenicity via the androgen receptor. Both vinclozolin and flutamide were antiandrogens of similar potency in the YAS assay. In the concentration range tested the two antiandrogens vinclozolin and flutamide did not act synergistically. Concentration additivity was observed in the linear, non-receptor-saturated concentration range. At high concentrations of one of the two substances tested the contribution of the second at lower concentration levels was less than additive. The combined response of both compounds at high concentration levels was also less than additive (saturation effect). At concentration levels which did not elicit a response of the individual compounds, the combination of these compounds also did not elicit a response. Copyright © 2011 Elsevier Inc. All rights reserved.

Ultrasound assisted forward osmosis concentration of fruit juice and natural colorant.

PubMed

Chanukya, B S; Rastogi, Navin K

2017-01-01

The present study deals with the effect of higher and lower molecular weight compounds present in the feed on concentration polarization during forward osmosis concentration and its mitigation by the application of ultrasound. The effects of ultrasound on transmembrane water flux at different forward osmosis membrane orientations and different model feed solutions consisting of sucrose and pectin have also been evaluated. The feed containing sucrose and pectin subjected towards active layer of the membrane was found to be the most suitable orientation. The application of ultrasound (30kHz) significantly reduced the concentration polarization when the feed contains sucrose concentration up to 5%. Whereas, in case of feed containing 0.5% pectin, the ultrasound was not found to be effective in dislodging the gel layer formation resulting in severe external concentration polarization on the membrane surface. In comparison to the ordinary forward osmosis process, the ultrasound-assisted forward osmosis process resulted in higher water fluxes in case of sweet lime juice as well as rose extract containing anthocyanin. The degradation of rose anthocyanin due to ultrasound was found to be 1.82%. Application of ultrasound was found to be an effective way in mitigating concentration polarization on the forward osmosis membrane resulting in increased flux. Copyright © 2016 Elsevier B.V. All rights reserved.

Saturation of conductance in single ion channels: the blocking effect of the near reaction field.

PubMed

Nadler, Boaz; Schuss, Zeev; Hollerbach, Uwe; Eisenberg, R S

2004-11-01

The ionic current flowing through a protein channel in the membrane of a biological cell depends on the concentration of the permeant ion, as well as on many other variables. As the concentration increases, the rate of arrival of bath ions to the channel's entrance increases, and typically so does the net current. This concentration dependence is part of traditional diffusion and rate models that predict Michaelis-Menten current-concentration relations for a single ion channel. Such models, however, neglect other effects of bath concentrations on the net current. The net current depends not only on the entrance rate of ions into the channel, but also on forces acting on ions inside the channel. These forces, in turn, depend not only on the applied potential and charge distribution of the channel, but also on the long-range Coulombic interactions with the surrounding bath ions. In this paper, we study the effects of bath concentrations on the average force on an ion in a single ion channel. We show that the force of the reaction field on a discrete ion inside a channel embedded in an uncharged lipid membrane contains a blocking (shielding) term that is proportional to the square root of the ionic bath concentration. We then show that different blocking strengths yield different behavior of the current-concentration and conductance-concentration curves. Our theory shows that at low concentrations, when the blocking force is weak, conductance grows linearly with concentration, as in traditional models, e.g., Michaelis-Menten formulations. As the concentration increases to a range of moderate shielding, conductance grows as the square root of concentration, whereas at high concentrations, with high shielding, conductance may actually decrease with increasing concentrations: the conductance-concentration curve can invert. Therefore, electrostatic interactions between bath ions and the single ion inside the channel can explain the different regimes of conductance-concentration relations observed in experiments.

Transport and retention of multi-walled carbon nanotubes in saturated porous media: Effects of input concentration and grain size

USDA-ARS?s Scientific Manuscript database

Water-saturated column experiments were conducted to investigate the effect of input concentration (Co) and sand grain size on the transport and retention of low concentrations (1, 0.01, and 0.005 mg L/1) of functionalized 14C-labeled multi-walled carbon nanotubes (MWCNT) under repulsive electrostat...

[Effect of IL-1beta on growth properties of vaginal microsymbionts].

PubMed

Kremleva, E A; Bukharin, O V

2013-01-01

Study the effect of IL-1beta in concentrations that are characteristic for vaginal normo- and pathocenosis on growth properties of vaginal microsymbionts. Concentration of IL-1beta in vaginal contents of women during bacterial vaginosis and normocenosis was determined by using enzume immunoassay. Changes of growth characteristics and biofilm formation ability of Staphylococcus aureus, Escherichia coli, Lactobacilus spp., Corynebacterium spp. under the effect of various IL-1beta concentrations by method of O'Toole G.A. (1999) were studied. IL-1beta in concentrations characteristic for normocenosis was shown to be able to cause stimulating effect on growth properties of lactobacilli and corynebacteria and suppress growth of S. aureus and E. coli in both plankton and biofilm cultures. IL-1beta concentrations characteristic for vaginal dysbiosis on the contrary result in suppression of growth of lactobacilli biomass against the background of stimulation of growth properties and biofilm formation ability of S. aureus and E. coli. Differential dose-dependent effect of IL-1beta on biomass growth and biofilm formation ability of vaginal microsymbionts is a mechanism of regulation of vaginal microbiocenosis.

Evaluating the effect of a clicker in an information literacy course for college nursing students in Taiwan.

PubMed

Lin, Kai-Yin

2015-03-01

In this technology era, information literacy is a global imperative. This is true for nursing students as well because they will have to help patients through operating computerized equipment. The key foundation of learning is concentration. The primary objectiveof this research was to explore the effect of clickers on nursing college students' concentration. The research involved 51 student volunteers and was quasi-experimental, with both a pretest and a posttest design. Student concentration was measured by using Student Concentration Scale in a Classroom-Learning Environment. The results showed that students' learning concentration improved, an outcome that could support integrating clickers into classroom teaching activities, and students' concentration level was better after clickers were used in the teaching process as a whole. Items under the "Concentration Capacity and Concentration Consciousness" category reached a significant level. Based on the analysis of the results, suggestions have been made for teaching and future research.

Effects of divalent cations and La3+ on contractility and ecto-ATPase activity in the guinea-pig urinary bladder.

PubMed Central

Ziganshin, A U; Ziganshina, L E; Hoyle, C H; Burnstock, G

1995-01-01

1. Several cations (Ba2+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Zn2+ and La3+, all as chloride salts, 1-1000 microM) were tested in the guinea-pig urinary bladder for their ability to: (i) modify contractile responses to electrical field stimulation (EFS), ATP, alpha,beta-methylene ATP (alpha,beta-meATP), carbachol (CCh), and KCl; (ii) affect ecto-ATPase activity. 2. Ba2+ (10-1000 microM) concentration-dependently potentiated contractile responses evoked by EFS (4-16 Hz), ATP (100 microM), alpha,beta-meATP (1 microM), CCh (0.5 microM), and KCl (30 mM). Ni2+ at concentrations of 1-100 microM also potentiated contractility of the urinary bladder, but at concentrations tested its effect was not concentration-dependent. Cu2+ at a concentration of 10 microM and Cd2+ at a concentration of 1 microM potentiated responses to all stimuli, except KCl. Ni2+ at a concentration of 1000 microM and Cd2+ at a concentration of 100 microM inhibited contractions evoked by all stimuli, and at a concentration of 1000 microM Cd2+ abolished any contractions. Responses to ATP and alpha,beta-meATP were selectively inhibited by Cu2+, Zn2+ or La3+, each at a concentration of 1 mM. 3. Cu2+, Ni2+, Zn2+ and La3+ (100-1000 microM) concentration-dependently inhibited ecto-ATPase activity in the urinary bladder smooth muscle preparations, while Ba2+ and Mn2+ were without effect, and Cd2+ and Co2+ caused significant inhibition only at a concentration of 1000 microM. 4. There was no correlation between the extent of ecto-ATPase inhibition and the effect on contractile activity of any of the cations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7735690

Biochemical effects of chlorpyrifos on two developmental stages of Xenopus laevis.

PubMed

Richards, Sean M; Kendall, Ron J

2002-09-01

Abstract-The effects of a 96-h static exposure to chlorpyrifos were examined in two developmental stages of larval Xenopus laevis (premetamorph and metamorph). Measures of effect included mortality, deformity, cholinesterase (ChE) activity, and DNA and protein concentration. All parameters indicated that metamorphs were more sensitive than were premetamorphs. For larvae exposed as premetamorphs, the median lethal concentration and median effective concentration were 14.6 mg/L and 1.71 mg/L; for those exposed as metamorphs, values were 0.56 mg/L and 0.24 mg/L, respectively. Cholinesterase activity was the most sensitive biochemical parameter. Exposure to chlorpyrifos at 0.01 mg/L caused significant decreases in the ChE activity of metamorphs; 0.1 mg/L significantly decreased premetamorph ChE activity. Metamorph DNA was significantly decreased at 0.1 mg/L; premetamorph DNA was not reduced until exposure to 1.0 mg/L. Whole-body protein was the least sensitive biochemical measure of effect. Premetamorphs did not experience a reduction in protein concentrations. Metamorph protein concentration was significantly decreased at 1.0 mg/L. Based on current surface water data, the most sensitive effect would not have a high probability (< or = 4.2%) of occurring in the environment.

Mechanisms Involved in Guiding the Preference for Fat Emulsion Differ Depending on the Concentration.

PubMed

Sakamoto, Kazuhiro; Matsumura, Shigenobu; Okafuji, Yoko; Eguchi, Ai; Lee, Shinhye; Adachi, Shin-ichi; Fujitani, Mina; Tsuzuki, Satoshi; Inoue, Kazuo; Fushiki, Tohru

2015-01-01

High-fat foods tend to be palatable and can cause addiction in mice via a reinforcing effect. However, mice showed preference for low fat concentrations that do not elicit a reinforcing effect in a two-bottle choice test with water as the alternative. This behavior indicates the possibility that the mechanism underlying fat palatability may differ depending on the dietary fat content. To address this issue, we examined the influences of the opioid system and olfactory and gustatory transductions on the intake and reinforcing effects of various concentrations of a dietary fat emulsion (Intralipid). We found that the intake and reinforcing effects of fat emulsion were reduced by the administration of an opioid receptor antagonist (naltrexone). Furthermore, the action of naltrexone was only observed at higher concentrations of fat emulsion. The intake and the reinforcing effects of fat emulsion were also reduced by olfactory and glossopharyngeal nerve transections (designated ONX and GLX, respectively). In contrast to naltrexone, the effects of ONX and GLX were mainly observed at lower concentrations of fat emulsion. These results imply that the opioid system seems to have a greater role in determining the palatability of high-fat foods unlike the contribution of olfactory and glossopharyngeal nerves.

Influence of Select Antibiotics on Vibrio fischeri and Desmodesmus subspicatus at μg L-1 Concentrations.

PubMed

de Vasconcelos, E C; Dalke, C R; de Oliveira, C M R

2017-07-01

The presence of pharmaceuticals in the aquatic environment is a contemporary reality and it is necessary to understand more about the effects of this presence on organisms. The purpose of this work was to assess the ecotoxicity of antibiotics metronidazole, nitrofurantoin, trimethoprim, and sulphamethoxazole (single and mixture) in Vibrio fischeri and Desmodesmus subspicatus at μg L -1 concentrations. The evaluation of the toxic effect of the antibiotics on V. fischeri and D. subspicatus was based on fluorescence and bioluminescence tests, respectively, using nominal concentrations. When tested individually, the four antibiotics gave rise to a toxic effect on the evaluated organisms. Sulphamethoxazole caused a higher toxic effect on V. fischeri and D. subspicatus from 7.81 to 500 μg L -1 . Trimethoprim and sulphamethoxazole showed hormesis for the concentrations, which ranged from 7.81 to 62.5 μg L -1 . The mixture of antibiotics induced a toxic effect on the V. fischeri and D. subspicatus organisms (from 0.03 to 1 μg L -1 concentrations) than when the antibiotics were evaluated individually. These results were significant since water quality problems are widespread all over the word, and emerging pollutants such as antibiotics have been detected in the aquatic environment in very low concentrations.

Hypnosis control based on the minimum concentration of anesthetic drug for maintaining appropriate hypnosis.

PubMed

Furutani, Eiko; Nishigaki, Yuki; Kanda, Chiaki; Takeda, Toshihiro; Shirakami, Gotaro

2013-01-01

This paper proposes a novel hypnosis control method using Auditory Evoked Potential Index (aepEX) as a hypnosis index. In order to avoid side effects of an anesthetic drug, it is desirable to reduce the amount of an anesthetic drug during surgery. For this purpose many studies of hypnosis control systems have been done. Most of them use Bispectral Index (BIS), another hypnosis index, but it has problems of dependence on anesthetic drugs and nonsmooth change near some particular values. On the other hand, aepEX has an ability of clear distinction between patient consciousness and unconsciousness and independence of anesthetic drugs. The control method proposed in this paper consists of two elements: estimating the minimum effect-site concentration for maintaining appropriate hypnosis and adjusting infusion rate of an anesthetic drug, propofol, using model predictive control. The minimum effect-site concentration is estimated utilizing the property of aepEX pharmacodynamics. The infusion rate of propofol is adjusted so that effect-site concentration of propofol may be kept near and always above the minimum effect-site concentration. Simulation results of hypnosis control using the proposed method show that the minimum concentration can be estimated appropriately and that the proposed control method can maintain hypnosis adequately and reduce the total infusion amount of propofol.

Effect of high concentrations of inorganic seed aerosols on secondary organic aerosol formation in the m-xylene/NO x photooxidation system

NASA Astrophysics Data System (ADS)

Lu, Zifeng; Hao, Jiming; Takekawa, Hideto; Hu, Lanhua; Li, Junhua

High concentrations (>15 μm 3 cm -3) of CaSO 4, Ca(NO 3) 2 and (NH 4) 2SO 4 were selected as surrogates of dry neutral, aqueous neutral and dry acidic inorganic seed aerosols, respectively, to study the effects of inorganic seeds on secondary organic aerosol (SOA) formation in irradiated m-xylene/NO x photooxidation systems. The results indicate that neither ozone formation nor SOA formation is significantly affected by the presence of neutral aerosols (both dry CaSO 4 and aqueous Ca(NO 3) 2), even at elevated concentrations. The presence of high concentrations of (NH 4) 2SO 4 aerosols (dry acidic) has no obvious effect on ozone formation, but it does enhance SOA generation and increase SOA yields. In addition, the effect of dry (NH 4) 2SO 4 on SOA yield is found to be positively correlated with the (NH 4) 2SO 4 surface concentration, and the effect is pronounced only when the surface concentration reaches a threshold value. Further, it is proposed that the SOA generation enhancement is achieved by particle-phase heterogeneous reactions induced and catalyzed by the acidity of dry (NH 4) 2SO 4 seed aerosols.

Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values

PubMed Central

Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

2015-01-01

It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago. PMID:25583135

Effect of Temperature and Nutrient Manipulations on eelgrass ...

EPA Pesticide Factsheets

Global climate change will have a large impact on the three predominate drivers of estuarine seagrass productivity, temperature, light and nutrients. I experimentally evaluate the response of Pacific Northwest Z. marina to interactive effects of temperature and nutrient conditions. Experimental manipulations were conducted hydroponically in acrylic chambers and spanned a range of temperatures and nutrient concentrations. Preliminary single factor experiments were conducted to evaluate physiological tolerances to temperature and nitrogen concentrations. Eelgrass exhibited a linear increase in specific growth with increasing NH4 concentration (range from 10 to 1000 µM); in contrast, there was no significant relationship between specific growth rate and increasing NO3 concentration over the same concentration range. Leaf growth metrics all exhibited strong linear relationships with increasing water temperature (temperature range 4-25 ºC). In the factorial experiment, plants were exposed to 3 temperatures (10, 18 and 25 ºC) and 3 nitrate concentrations (10, 30 and 100 µM) with 3 replicate chambers per treatment combination. Most metrics (leaf elongation, growth, specific growth, wasting index) exhibited a significant temperature effect indicating the importance of temperature on metabolic rates. Tissue stable isotope ratios and C:N values exhibited a significant nutrient effect and in some cases a significant temperature effect. Whole plant non structur

Anticonvulsants

NASA Astrophysics Data System (ADS)

Kabra, Pokar M.; Stafford, Brian E.; McDonald, Donna M.; Marton, Laurence J.

Until recently, it was difficult to explain why an identical drug dosage may exert a toxic effect in one patient and a therapeutic, or no, response in another patient. It has now been demonstrated that the concentration of drug at the tissue receptor site is the most important parameter for adjusting drug dosage. However, the concentration of drug at the receptor site cannot be measured directly, and must therefore be correlated with the concentration of drug in body fluids in contact with these tissue receptors. The ability to correlate plasma drug concentration with tissue concentrations and with therapeutic or toxic effects has enabled those interested in optimizing drug dosages to generate much of the information needed to make useful therapeutic decisions. The exact nature of drug-receptor interactions is not firmly established. It is, however, known that the concentration of free drug correlates best with therapeutic effect. The free drug in plasma is in equilibrium with protein-bound drug and, because of this relationship, it is important to understand to what extent a particular drug is protein-bound. Various attempts to measure free drug concentration in saliva (1) and cerebrospinal fluid (2) have been reported.

Fermentation of molasses using a thermotolerant yeast, Kluyveromyces marxianus IMB3: simplex optimisation of media supplements.

PubMed

Gough, S; Flynn, O; Hack, C J; Marchant, R

1996-09-01

The use of molasses as a substrate for ethanol production by the thermotolerant yeast Kluyveromyces marxianus var. marxianus was investigated at 45 degrees C. A maximum ethanol concentration of 7.4% (v/v) was produced from unsupplemented molasses at a concentration of 23% (v/v). The effect on ethanol production of increasing the sucrose concentration in 23% (v/v) molasses was determined. Increased sucrose concentration had a similar detrimental effect on the final ethanol produced as the increase in molasses concentration. This indicated that the effect may be due to increased osmotic activity as opposed to other components in the molasses. The optimum concentration of the supplements nitrogen, magnesium, potassium and fatty acid for maximum ethanol production rate was determined using the Nelder and Mead (Computer J 7:308-313, 1965) simplex optimisation method. The optimum concentration of the supplements were 0.576 g1(-1) magnesium sulphate, 0.288 g1(-1) potassium dihydrogen phosphate and 0.36% (v/v) linseed oil. Added nitrogen in the form of ammonium sulphate did not affect the ethanol production rate.

Hibernation-Based Therapy to Improve Survival of Severe Blood Loss

DTIC Science & Technology

2013-10-01

NOTES 14. ABSTRACT The purpose of these experiments was to find the most effective concentration of melatonin /DMSO that could be administered in...conjunction with 4M BHB. Three concentrations were tested, 43mM Melatonin /20% DMSO, 4.3mM Melatonin /2% DMSO and 0.43mM Melatonin /2% DMSO. It was...found that 43mM Melatonin /20% DMSO given in conjunction with 4M BHB was the most effective concentration. This concentration, 43mM Melatonin /20% DMSO

Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Li-Wu; Wu, Qiangen; Green, Bridgett

2012-07-15

Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCSmore » (≥ 5.0 μM TCS), but not with low-concentration treatments (≤ 2.5 μM TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 μM range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. -- Highlights: ► TCS is cytotoxic to un-induced hMSCs at concentrations ≥ 5.0 μM. ► TCS at concentrations ≤ 2.5 μM is not cytotoxic to induced hMSCs. ► TCS at non-cytotoxic concentrations inhibits lipid formation in induced hMSCs. ► TCS decreases the expression of specific biomarkers of adipocyte differentiation. ► TCS at concentrations observed in human blood inhibits adipogenesis of hMSCs.« less

Pharmacokinetics of a concentrated buprenorphine formulation in red-tailed hawks (Buteo jamaicensis).

PubMed

Gleeson, Molly D; Guzman, David Sanchez-Migallon; Knych, Heather K; Kass, Philip H; Drazenovich, Tracy L; Hawkins, Michelle G

2018-01-01

OBJECTIVE To determine the pharmacokinetics and sedative effects of 2 doses of a concentrated buprenorphine formulation after SC administration to red-tailed hawks (Buteo jamaicensis). ANIMALS 6 adult red-tailed hawks. PROCEDURES Concentrated buprenorphine (0.3 mg/kg, SC) was administered to all birds. Blood samples were collected at 10 time points over 24 hours after drug administration to determine plasma buprenorphine concentrations. After a 4-week washout period, the same birds received the same formulation at a higher dose (1.8 mg/kg, SC), and blood samples were collected at 13 time points over 96 hours. Hawks were monitored for adverse effects and assigned agitation-sedation scores at each sample collection time. Plasma buprenorphine concentrations were quantified by liquid chromatography-tandem mass spectrometry. RESULTS Mean time to maximum plasma buprenorphine concentration was 7.2 minutes and 26.1 minutes after administration of the 0.3-mg/kg and 1.8-mg/kg doses, respectively. Plasma buprenorphine concentrations were > 1 ng/mL for mean durations of 24 and 48 hours after low- and high-dose administration, respectively. Mean elimination half-life was 6.23 hours for the low dose and 7.84 hours for the high dose. Mean agitation-sedation scores were higher (indicating some degree of sedation) than the baseline values for 24 hours at both doses. No clinically important adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Concentrated buprenorphine was rapidly absorbed, and plasma drug concentrations considered to have analgesic effects in other raptor species were maintained for extended periods. Most birds had mild to moderate sedation. Additional studies are needed to evaluate the pharmacodynamics of these doses of concentrated buprenorphine in red-tailed hawks.

Effects of Atmospheric Water and Surface Wind on Passive Microwave Retrievals of Sea Ice Concentration: a Simulation Study

NASA Astrophysics Data System (ADS)

Shin, D.; Chiu, L. S.; Clemente-Colon, P.

2006-05-01

The atmospheric effects on the retrieval of sea ice concentration from passive microwave sensors are examined using simulated data typical for the Arctic summer. The simulation includes atmospheric contributions of cloud liquid water, water vapor and surface wind on the microwave signatures. A plane parallel radiative transfer model is used to compute brightness temperatures at SSM/I frequencies over surfaces that contain open water, first-year (FY) ice and multi-year (MY) ice and their combinations. Synthetic retrievals in this study use the NASA Team (NT) algorithm for the estimation of sea ice concentrations. This study shows that if the satellite sensor's field of view is filled with only FY ice the retrieval is not much affected by the atmospheric conditions due to the high contrast between emission signals from FY ice surface and the signals from the atmosphere. Pure MY ice concentration is generally underestimated due to the low MY ice surface emissivity that results in the enhancement of emission signals from the atmospheric parameters. Simulation results in marginal ice areas also show that the atmospheric effects from cloud liquid water, water vapor and surface wind tend to degrade the accuracy at low sea ice concentration. FY ice concentration is overestimated and MY ice concentration is underestimated in the presence of atmospheric water and surface wind at low ice concentration. This compensating effect reduces the retrieval uncertainties of total (FY and MY) ice concentration. Over marginal ice zones, our results suggest that strong surface wind is more important than atmospheric water in contributing to the retrieval errors of total ice concentrations in the normal ranges of these variables.

EFFECTS OF HYPERTHERMIA AND HYPERTHERMIA PLUS MICROWAVES ON RAT BRAIN ENERGY METABOLISM

EPA Science Inventory

The effects of hyperthermia, alone and in conjunction with microwave exposure, on brain energetics were studied in anesthetized male Sprague-Dawley rats. The effects of temperature on adenosine triphosphate concentration (ATP) and creatine phosphate concentration (CP) was determi...

Early life stage (ELS) toxicity of sucralose to fathead minnows, Pimephales promelas.

PubMed

Stoddard, K I; Huggett, D B

2014-10-01

Sucralose, an intense artificial sweetener, has been detected in wastewater and surface waters at concentrations ranging from ng/L to low µg/L. Although over a hundred studies have been conducted to evaluate the safety of sucralose for human consumption, few studies have focused on the chronic ecotoxicological effects of this compound in fish. As a remedy to this data gap, an early-life stage toxicity test was conducted to assess the effects of sucralose on hatching, survival, and growth of fathead minnows (Pimephales promelas). Hatching, survival, and growth were unaffected by 98 mg/L of sucralose. The Lowest-Observed-Effect Concentration (LOEC) and the No-Observed-Effect Concentration (NOEC) for fathead minnows determined by this study are >98 and 98 mg/L, respectively. The results from this study suggest that the concentrations of sucralose detected in the environment are well below those required to cause adverse effects to developing aquatic organisms.

PCB concentrations of lake whitefish (Coregonus clupeaformis) vary by sex

USGS Publications Warehouse

Madenjian, Charles P.; Ebener, Mark P.; Sepulveda, Maria S.

2015-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations in 26 female lake whitefish (Coregonus clupeaformis) and 34 male lake whitefish from northern Lake Huron. In 5 of the 26 female lake whitefish, we also determined PCB concentrations in the somatic tissue and ovaries. In addition, bioenergetics modeling was used to determine the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 60 ng/g and 80 ng/g, respectively; thus males were 34% higher in PCB concentration compared with females. Based on the PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 2.5%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain, to any degree, the higher PCB concentrations observed in males compared with females. Bioenergetics modeling results indicated that the growth dilution effect could account for males being only 0.7% higher in PCB concentration compared with females. Thus, the growth dilution effect contributed very little to the observed difference in PCB concentrations between the sexes. We conclude that males were higher than females in PCB concentration most likely due to a higher rate of energy expenditure, stemming from greater activity and a greater resting metabolic rate. A higher rate of energy expenditure leads to a higher rate of food consumption, which, in turn, leads to a higher PCB accumulation rate.

Assessment in vitro of cytogenetic and genotoxic effects of propolis on human lymphocytes.

PubMed

Montoro, A; Soriano, J M; Barquinero, J F; Almonacid, M; Montoro, A; Verdú, G; Sahuquillo, V; Villaescusa, J I; Sebastià, N

2012-02-01

We evaluated the genetic damage by ethanolic extract of propolis (EEP) induced to human lymphocytes which were exposed to increasing concentrations (0-2000μgml(-1)). The results indicated that EEP reduced significantly the mitotic index (MI) and proliferation index (PI) when high concentrations of EEP were used. Sister chromatid exchange (SCE) rates indicated that EEP could have genotoxic effects at high concentrations. Exposure of the cells to the amount of ethanol used as solvent did not alter either the MI and cell proliferation kinetics (CPK), or the rate of SCE. The results showed: (a) statistical increase in the percentage the cells with CAs and in the frequency of SCE at the highest concentrations, (b) a decrease in MI and in the CPK values was observed, (c) no effect was noticed in negative controls. In conclusion, it can be assumed that high concentrations of EEP have a cyto and genotoxic effect, in vitro, for human peripheral lymphocytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Optimisation of medium composition for probiotic biomass production using response surface methodology.

PubMed

Anvari, Masumeh; Khayati, Gholam; Rostami, Shora

2014-02-01

This study was aimed to optimise lactose, inulin and yeast extract concentration and also culture pH for maximising the growth of a probiotic bacterium, Bifidobacterium animalis subsp. lactis in apple juice and to assess the effects of these factors by using response surface methodology. A second-order central composite design was applied to evaluate the effects of these independent variables on growth of the microorganism. A polynomial regression model with cubic and quadratic terms was used for analysis of the experimental data. It was found that the effects involving inulin, yeast extract and pH on growth of the bacterium were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors on the bacterial growth are as follows: lactose concentration=9·5 g/l; inulin concentration=38·5 mg/l; yeast extract concentration=9·6 g/l and initial pH=6·2.

Effects of carbon nanotubes on atrazine biodegradation by Arthrobacter sp.

PubMed

Zhang, Chengdong; Li, Mingzhu; Xu, Xu; Liu, Na

2015-04-28

The environmental risks of engineered nanoparticles have attracted attention. However, little is known regarding the effects of carbon nanotubes (CNTs) on the biodegradation and persistence of organic contaminants in water. We investigated the impacts of pristine and oxidized multiwalled CNTs on the atrazine biodegradation rate and efficiency using Arthrobacter sp. At a concentration of 25mg/L, the CNTs enhanced the biodegradation rate by up to 20%; however, at a concentration of 100mg/L, the CNTs decreased the biodegradation rate by up to 50%. The stimulation effects resulted from enhanced bacterial growth and the overexpression of degradation genes. The inhibitory effects resulted from the toxicity of the CNTs at high concentrations. The differences between the two CNTs at tested concentrations were not significant. The biodegradation efficiency was not impacted by adsorption, and the pre-adsorbed atrazine on the CNTs was fully biodegraded when the CNT concentration was ≤25mg/L. This finding was consistent with the lack of observable desorption hysteresis for atrazine on the tested CNTs. Our results indicate that CNTs can enhance or inhibit biodegradation through a balance of two effects: the toxic effects on microbial activity and the effects of the changing bioavailability that result from adsorption and desorption. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of phloretin on lipid organization in the erythrocyte membrane as measured by EPR

NASA Astrophysics Data System (ADS)

Abumrad, Nada A.; Perkins, Ray C.; Dalton, Larry R.; Park, Charles R.; Park, Jane H.

Phloretin is a lipophilic compound which has been widely studied as a broad spectrum effector of metabolite transport in red blood cells (RBC). Phloretin effects on the organization of lipids in the RBC membrane are investigated using the spin-labeled fatty acids, 5 and 16-nitroxyl stearate (5-NS and 16-NS, respectively). Phloretin at different concentrations produced biphasic effects on the lineshape of the EPR response from 16-NS-labeled RBC. The dependence of these changes on the flat cell orientation with respect to the magnetic field suggested that phloretin promoted lipid order at low concentrations (5 to 40 μ M) and disorder at high concentrations (40 to 250 μ M). The biphasic effects of phloretin occurred at concentrations which parallel its dual actions on metabolite transfer. Phloretin generally inhibits transport (protein-mediated) and stimulates diffusion (lipid-mediated) processes. The spectroscopic effects were best characterized through second-harmonic, in-phase detection. The possible contribution of other factors to the spectroscopic changes is discussed. When RBC were spin labeled with 5-NS, higher concentrations of the probe were required for adequate detection and only monophasic effects of phoretin were observed. The results suggest that membrane lipids are important in phloretin effects on transport and diffusion processes.

Effects of turbulence on warm clouds and precipitation with various aerosol concentrations

NASA Astrophysics Data System (ADS)

Lee, Hyunho; Baik, Jong-Jin; Han, Ji-Young

2015-02-01

This study investigates the effects of turbulence-induced collision enhancement (TICE) on warm clouds and precipitation by changing the cloud condensation nuclei (CCN) number concentration using a two-dimensional dynamic model with bin microphysics. TICE is determined according to the Taylor microscale Reynolds number and the turbulent dissipation rate. The thermodynamic sounding used in this study is characterized by a warm and humid atmosphere with a capping inversion layer, which is suitable for simulating warm clouds. For all CCN concentrations, TICE slightly reduces the liquid water path during the early stage of cloud development and accelerates the onset of surface precipitation. However, changes in the rainwater path and in the amount of surface precipitation that are caused by TICE depend on the CCN concentrations. For high CCN concentrations, the mean cloud drop number concentration (CDNC) decreases and the mean effective radius increases due to TICE. These changes cause an increase in the amount of surface precipitation. However, for low CCN concentrations, changes in the mean CDNC and in the mean effective radius induced by TICE are small and the amount of surface precipitation decreases slightly due to TICE. A decrease in condensation due to the accelerated coalescence between droplets explains the surface precipitation decrease. In addition, an increase in the CCN concentration can lead to an increase in the amount of surface precipitation, and the relationship between the CCN concentration and the amount of surface precipitation is affected by TICE. It is shown that these results depend on the atmospheric relative humidity.

Modeling the Factors Impacting Pesticide Concentrations in Groundwater Wells.

PubMed

Aisopou, Angeliki; Binning, Philip J; Albrechtsen, Hans-Jørgen; Bjerg, Poul L

2015-01-01

This study examines the effect of pumping, hydrogeology, and pesticide characteristics on pesticide concentrations in production wells using a reactive transport model in two conceptual hydrogeologic systems; a layered aquifer with and without a stream present. The pumping rate can significantly affect the pesticide breakthrough time and maximum concentration at the well. The effect of the pumping rate on the pesticide concentration depends on the hydrogeology of the aquifer; in a layered aquifer, a high pumping rate resulted in a considerably different breakthrough than a low pumping rate, while in an aquifer with a stream the effect of the pumping rate was insignificant. Pesticide application history and properties have also a great impact on the effect of the pumping rate on the concentration at the well. The findings of the study show that variable pumping rates can generate temporal variability in the concentration at the well, which helps understanding the results of groundwater monitoring programs. The results are used to provide guidance on the design of pumping and regulatory changes for the long-term supply of safe groundwater. The fate of selected pesticides is examined, for example, if the application of bentazone in a region with a layered aquifer stops today, the concentration at the well can continue to increase for 20 years if a low pumping rate is applied. This study concludes that because of the rapid response of the pesticide concentration at the drinking water well due to changes in pumping, wellhead management is important for managing pesticide concentrations. © 2014, National GroundWater Association.

Low-flow anesthesia and reduced animal size increase carboxyhemoglobin levels in swine during desflurane and isoflurane breakdown in dried soda lime.

PubMed

Bonome, C; Belda, J; Alvarez-Refojo, F; Soro, M; Fernández-Goti, C; Cortés, A

1999-10-01

After institutional approval, we studied the effect of animal size, anesthetic concentration, and fresh gas flow (FGF) rate on inspired carbon monoxide (CO) and carboxyhemoglobin (COHb) during anesthesia in swine, using soda lime previously dried to 1 +/- 0.1% water content. To ascertain the effect of anesthesia, eight adult pigs were anesthetized with either 1 minimum alveolar anesthetic concentration (MAC) desflurane or isoflurane and, to characterize the effect of the FGF rate, it was doubled in four pigs. To determine the effect of animal size, four small and four large pigs received 1 MAC desflurane or isoflurane, and to determine the effect of the anesthetic concentration, a group of four swine was exposed to 0.5 MAC. CO and COHb concentrations were larger with desflurane (5500 +/- 980 ppm and 57.90% +/- 0.50%, respectively) than with isoflurane (800 ppm and 17.8% +/- 2.14%, respectively), especially in the small animals. Increasing the FGF rate significantly reduced peak CO and COHb concentrations resulting from both anesthetics; however, when each anesthetic was reduced to 0.5 MAC, the concentrations obtained were similar. We conclude that CO intoxication is more severe with desflurane than with isoflurane, that small animals are at higher risk for CO poisoning, and that low FGF can increase COHb concentrations. The present study shows that the use of desflurane with desiccated carbon dioxide absorbents in pediatric anesthesia can produce a dangerous carbon dioxide intoxication, especially with low-flow anesthesia.

Phytotoxicity of glyphosate in the germination of Pisum sativum and its effect on germinated seedlings

PubMed Central

2017-01-01

The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds and seedlings. Physicochemical biomarkers were significantly changed by glyphosate exposure after 15 days. The germination of seedlings under control conditions (0 mg/L) was 100% after 3 days of treatment but at 3 and 4 mg/L glyphosate, germination was reduced to 55 and 40%, respectively. Physiological parameters like root and shoot length decreased monotonically with increasing glyphosate concentration, at 14 days of observation. Average root and shoot length (n=30 in three replicates) were reduced to 14.7 and 17.6%, respectively, at 4 mg/L glyphosate. Leaf chlorophyll content also decreased, with a similar trend to root and shoot length, but the protein content initially decreased and then increased with an increase in glyphosate concentration to 3 mg/L. The study suggests that glyphosate reduces the soluble sugar content significantly, by 21.6% (v/v). But internal sodium and potassium tissue concentrations were significantly altered by glyphosate exposure with increasing concentrations of glyphosate. Biochemical and physiological analysis also supports the inhibitory effect of glyphosate on seed germination and biochemical effects on seedlings. PMID:28728354

Evaluation of the cytotoxic and antimutagenic effects of biflorin, an antitumor 1,4 o-naphthoquinone isolated from Capraria biflora L.

PubMed

Vasconcellos, Marne C; Moura, Dinara J; Rosa, Renato M; Machado, Miriana S; Guecheva, Temenouga N; Villela, Izabel; Immich, Bruna F; Montenegro, Raquel C; Fonseca, Aluísio M; Lemos, Telma L G; Moraes, Maria Elisabete A; Saffi, Jenifer; Costa-Lotufo, Letícia V; Moraes, Manoel O; Henriques, João A P

2010-10-01

Biflorin is a natural quinone isolated from Capraria biflora L. Previous studies demonstrated that biflorin inhibits in vitro and in vivo tumor cell growth and presents potent antioxidant activity. In this paper, we report concentration-dependent cytotoxic, genotoxic, antimutagenic, and protective effects of biflorin on Salmonella tiphymurium, yeast Saccharomyces cerevisiae, and V79 mammalian cells, using different approaches. In the Salmonella/microsome assay, biflorin was not mutagenic to TA97a TA98, TA100, and TA102 strains. However, biflorin was able to induce cytotoxicity in haploid S. cerevisiae cells in stationary and exponential phase growth. In diploid yeast cells, biflorin did not induce significant mutagenic and recombinogenic effects at the employed concentration range. In addition, the pre-treatment with biflorin prevented the mutagenic and recombinogenic events induced by hydrogen peroxide (H(2)O(2)) in S. cerevisiae. In V79 mammalian cells, biflorin was cytotoxic at higher concentrations. Moreover, at low concentrations biflorin pre-treatment protected against H(2)O(2)-induced oxidative damage by reducing lipid peroxidation and DNA damage as evaluated by normal and modified comet assay using DNA glycosylases. Our results suggest that biflorin cellular effects are concentration dependent. At lower concentrations, biflorin has significant antioxidant and protective effects against the cytotoxicity, genotoxicity, mutagenicity, and intracellular lipid peroxidation induced by H(2)O(2) in yeast and mammalian cells, which can be attributed to its hydroxyl radical-scavenging property. However, at higher concentrations, biflorin is cytotoxic and genotoxic.

Effect of In Vitro Human Digestion on Biogenic Amine (Tyramine) Formation in Various Fermented Sausages.

PubMed

Kim, Hyeong Sang; Hur, Sun Jin

2018-03-01

Biogenic amines are formed in various fermented foods by microbial amino acid decarboxylation activities, and ingestion of these amines may cause human illness. However, the effect of digestion on the biogenic amines in fermented sausages has not been studied. This study was conducted to determine the effect of in vitro human digestion with the enterobacteria Escherichia coli and Lactobacillus casei on concentrations of the biogenic amine tyramine in six types of fermented sausages. Tyramine concentration was not significantly changed until simulated digestion in the small intestine. However, tyramine concentration for all sausage samples was increased after simulated digestion in the large intestine. Addition of E. coli and L. casei dramatically increased the tyramine concentrations ( P < 0.05). This result indicates that enterobacteria increase biogenic amine concentrations during human digestion.

The Management of Lead Concentrate Acquisition in "Trepca"

NASA Astrophysics Data System (ADS)

Haxhiaj, Ahmet; Fan, Maoming; Haxhiaj, Bajram

Based on the placement of lead and its consumption in industry branches, the paper deals with the composition of lead in the ores of Kopaonik, grinding and flotation recovery of galena. In the flotation process, the flotation machine, the flotation reagents, chemical composition of the flotation concentrates and tailings were discussed in this paper. Verification of the chemical composition of Pb concentrates with Pb, Zn, and Ag, etc. was conducted in this study. It is special that the ratio of Pb to Zn in Kopaonik massive composition is 1.4:1.0. During the flotation, lead tends to float with concentrate more than allowed. In this investigation, effects have been made to minimize the loss of Pb to concentrates. This paper as such gave the first effects in optimizing of these parameters with positive effects in the flotation process in Trepca.

Root characteristics of cover crops and their erosion-reducing potential during concentrated runoff

NASA Astrophysics Data System (ADS)

de Baets, S.; Poesen, J.

2009-04-01

In the loam region in central Belgium, a lot of research has been conducted on the effects of cover crops for preventing splash and interrill erosion and on their nutrient pumping effectiveness. As this is a very effective erosion and environment conservation technique, planting cover crops during the winter season is widely applied in the loess belt. Most of these cover crops freeze at the beginning of the winter period. Consequently, the above-ground biomass becomes less effective in protecting the soil from water erosion. Apart from the effects of the above-ground biomass in protecting the soil against raindrop impacts and reducing flow velocities by the retarding effects of their stems, plant roots also play an important role in improving soil strength. Previous research showed that roots contribute to a large extent to the resistance of topsoils against concentrated flow erosion. Unfortunately, information on root properties of common cover crops (e.g. Sinapis alba, Phacelia tanacetifoli, Lolium perenne, Avena sativa, Secale cereale, Raphanus sativus subsp. oleiferus) is very scarce. Therefore, root density distribution with depth and their erosion-reducing effects during concentrated flow erosion were assessed by conducting root auger measurements and concentrated flow experiments at the end of the growth period (December). The preliminary results indicate that the studied cover crops are not equally effective in preventing soil loss by concentrated flow erosion at the end of the growing season. Cover crops with thick roots, such as Sinapis alba and Raphanus sativus subsp. oleiferus are less effective than cover crops with fine-branched roots such as Phacelia tanacetifoli, Lolium perenne (Ryegrass), Avena sativa (Oats) and Secale cereale (Rye) in preventing soil losses by concentrated flow erosion. These results enable soil managers to select the most suitable crops and maximize soil protection.

Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

PubMed

Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

2015-01-01

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

Combined effects of deforestation and doubled atmospheric CO{sub 2} concentrations on the climate of Amazonia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costa, M.H.; Foley, J.A.

2000-01-01

It is generally expected that the Amazon basin will experience at least two major environmental changes during the next few decades and centuries: (1) increasing areas of forest will be converted to pasture and cropland, and (2) concentrations of atmospheric CO{sub 2} will continue to rise. In this study, the authors use the National Center for Atmospheric Research GENESIS atmospheric general circulation model, coupled to the Integrated Biosphere Simulator, to determine the combined effects of large-scale deforestation and increased CO{sub 2} concentrations (including both physiological and radiative effects) on Amazonian climate. In these simulations, deforestation decreases basin-average precipitation by 0.73more » mm day{sup {minus}1} over the basin, as a consequence of the general reduction in vertical motion above the deforested area (although there are some small regions with increased vertical motion). The overall effect of doubled CO{sub 2} concentrations in Amazonia is an increase in basin-average precipitation of 0.28 mm day{sup {minus}1}. The combined effect of deforestation and doubled CO{sub 2}, including the interactions among the processes, is a decrease in the basin-average precipitation of 0.42 mm day{sup {minus}1}. While the effects of deforestation and increasing CO{sub 2} concentrations on precipitation tend to counteract one another, both processes work to warm the Amazon basin. The effect of deforestation and increasing CO{sub 2} concentrations both tent to increase surface temperature, mainly because of decreases in evapotranspiration and the radiative effect of CO{sub 2}. The combined effect of deforestation and doubled CO{sub 2}, including the interactions among the processes, increases the basin-average temperature by roughly 3.5 C.« less

Numerical simulation of double front detonations in a non-ideal explosive with varying aluminum concentration

NASA Astrophysics Data System (ADS)

Kim, Wuhyun; Gwak, Min-Cheol; Yoh, Jack; Seoul National University Team

2017-06-01

The performance characteristics of aluminized HMX are considered by varying the aluminum (Al) concentration in a hybrid non-ideal detonation model. Two cardinal observations are reported: a decrease in detonation velocity with an increase in Al concentration and a double front detonation (DFD) feature when aerobic Al reaction occurs behind the front. While experimental studies have been reported on the effect of Al concentration on both gas-phase and solid-phase detonations, the numerical investigations were limited to only gas-phase detonation for the varying Al concentration. In the current study, a two-phase model is utilized for understanding the volumetric effects of Al concentration in the condensed phase detonations. A series of unconfined and confined rate sticks are considered for characterizing the performance of aluminized HMX with a maximum Al concentration of 50%. The simulated results are compared with the experimental data for 5%-25% concentrations, and the formation of DFD structure under varying Al concentration (0%-50%) in HMX is investigated.

Falling-stream turbidimeter as a means of measuring sediment concentrations in streams

USGS Publications Warehouse

Guy, Harold P.; Olson, Richard C.

1972-01-01

The ratio of suspended-sediment concentration to the square root of the median particle size of sand-sized sediments was found to be a useful parameter for elimination of the effect of particle size in the relative transparency-concentration relationships. Thus it was possible to evaluate the effect of the different type of sediment on the relative transparency independent of particle size. The use of this parameter to eliminate the effect of particle size was unsuccessful for finer sediments. -

Effects of debrisoquin and haloperidol on plasma homovanillic acid concentration in schizophrenic patients.

PubMed

Davidson, M; Losonczy, M F; Mohs, R C; Lesser, J C; Powchik, P; Freed, L B; Davis, B M; Mykytyn, V V; Davis, K L

1987-12-01

Plasma levels of the dopamine metabolite homovanillic acid (pHVA) may potentially reflect upon central dopamine activity. This study examines the effects of debrisoquin, haloperidol, and the two drugs combined on pHVA concentrations of schizophrenic patients. Debrisoquin is a drug that suppresses the peripheral formation of homovanillic acid without affecting the central formation. Acute haloperidol administration consistently increased pHVA concentrations in patients pretreated or not pretreated with debrisoquin, suggesting that this increment reflects haloperidol's central and not peripheral effects.

The toxic effect of different concentrations of povidone iodine on the rabbit's cornea.

PubMed

Jiang, Jin; Wu, Miaoqin; Shen, Ting

2009-01-01

To investigate the effects of polyvinylpyrrolidone (i.e., povidone) iodine (PVP-I) in different concentrations on the rabbit's cornea. PVP-I in various concentrations was instilled into the conjunctival sac and injected into the anterior chamber independently. The toxicity to the cornea was assessed by fluorescence dye, specular microscopy, and corneal pachymetry. After conjunctival sac PVP-I instillation, severe epithelial damage was observed at the concentrations of 5.0% and 2.5%. After anterior chamber PVP-I injection, significant corneal edema was observed at the concentrations of 2.0% and 1.5%. It can be safe and feasible to use 0.5% or 1.0% concentrations of PVP-I in conjunctival sac instillation for preoperative antisepsis.

The Effect of Pluronic 123 Surfactant concentration on The N2 Adsorption Capacity of Mesoporous Silica SBA-15: Dubinin-Astakhov Adsorption Isotherm Analysis

NASA Astrophysics Data System (ADS)

Dhaneswara, Donanta; Siti Agustina, A. A. A.; Dewantoro Adhy, P.; Delayori, Farhan; Fajar Fatriansyah, Jaka

2018-04-01

Mesoporous SBA-15 has been successfully synthesized at various concentration of Pluronic 123 surfactant (7mM, 50 mM, 54 mM, 60 mM and 66 mM) and the effect of these various concentrations on the N2 adsorption capacity has been investigated. The adsorption analysis was conducted using Dubinin-Astakhov isotherm model for multilayer adsorption phenomenon. It was found that etryat low concentration of Pluronic 123, the system exhibits type I adsorption isotherm while at high concentration, the system exhibits type IV adsorption with H1 hysteresis curve which indicates the existence of pores with cylindrical geometry, relatively uniform pore size and possibility of pore network effects. It also was found that, by using D-A isotherm model fitting, at 60 mM concentration of Pluronic 123, SBA-15 has the highest adsorption capacity which stands at 421 cm3/gram.

The quantitative effect of serum albumin, serum urea, and valproic acid on unbound phenytoin concentrations in children.

PubMed

ter Heine, Rob; van Maarseveen, Erik M; van der Westerlaken, Monique M L; Braun, Kees P J; Koudijs, Suzanne M; Berg, Maarten J Ten; Malingré, Mirte M

2014-06-01

Dosing of phenytoin is difficult in children because of its variable pharmacokinetics and protein binding. Possible covariates for this protein binding have mostly been univariately investigated in small, and often adult, adult populations. We conducted a study to identify and quantify these covariates in children. We extracted data on serum phenytoin concentrations, albumin, triglycerides, urea, total bilirubin and creatinine concentrations and data on coadministration of valproic acid or carbamazepine in 186 children. Using nonlinear mixed effects modeling the effects of covariates on the unbound phenytoin fraction were investigated. Serum albumin, serum urea concentrations, and concomitant valproic acid use significantly influenced the unbound phenytoin fraction. For clinical practice, we recommend that unbound phenytoin concentrations are measured routinely. However, if this is impossible, we suggest to use our model to calculate the unbound concentration. In selected children, close treatment monitoring and dose reductions should be considered to prevent toxicity. © The Author(s) 2013.

Effect of pH and nitrite concentration on nitrite oxidation rate.

PubMed

Jiménez, E; Giménez, J B; Ruano, M V; Ferrer, J; Serralta, J

2011-10-01

The effect of pH and nitrite concentration on the activity of the nitrite oxidizing bacteria (NOB) in an activated sludge reactor has been determined by means of laboratory batch experiments based on respirometric techniques. The bacterial activity was measured at different pH and at different total nitrite concentrations (TNO₂). The experimental results showed that the nitrite oxidation rate (NOR) depends on the TNO₂ concentration independently of the free nitrous acid (FNA) concentration, so FNA cannot be considered as the real substrate for NOB. NOB were strongly affected by low pH values (no activity was detected at pH 6.5) but no inhibition was observed at high pH values (activity was nearly the same for the pH range 7.5-9.95). A kinetic expression for nitrite oxidation process including switch functions to model the effect of TNO₂ concentration and pH inhibition is proposed. Substrate half saturation constant and pH inhibition constants have been obtained. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of sorption on exposures to organic gases from environmental tobacco smoke (ETS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, B.C.; Hodgson, A.T.; Nazaroff, W.W.

The effects of sorption processes on dynamic ETS organic gas concentrations and potential exposures were studied in a carpeted and furnished 50-m{sup 3} room ventilated at 0.6 h{sup -1}. Ten cigarettes were machine-smoked on six of every seven days over four weeks. Concentrations of ETS-specific tracers and regulated toxic compounds were quantified during daily smoking, post-smoking and background periods. Potential exposures were calculated by period and day. Large sorption effects were observed for the widely used tracers 3-ethenylpyridine and nicotine, and for several toxic compounds including naphthalene and cresol isomers. Short-term adsorption to indoor surfaces reduced concentrations and potential exposuresmore » during smoking, while later reemission increased concentrations and exposures hours after smoking ended. Concentrations during nonsmoking periods rose from day to day over the first few weeks, presumably from increased reemission associated with increased sorbed mass concentrations. For sorbing compounds, more than half of daily potential exposures occurred during nonsmoking periods.« less

Rotary Apparatus Concentrates And Separates Micro-Organisms

NASA Technical Reports Server (NTRS)

Noever, David A.

1992-01-01

Apparatus concentrates and separates swimming micro-organisms of different species into concentric rings in fluid. Fluid containing high concentration of desired species removed by use of small scoop placed into fluid at radius of one of rings formed by that species. Micro-organisms concentrated into concentric rings by combined dynamic effects of upward and horizontal components of swimming, rotation of dish, gravitation, and viscosity.

Investigation on Dynamic Calibration for an Optical-Fiber Solids Concentration Probe in Gas-Solid Two-Phase Flows

PubMed Central

Xu, Guiling; Liang, Cai; Chen, Xiaoping; Liu, Daoyin; Xu, Pan; Shen, Liu; Zhao, Changsui

2013-01-01

This paper presents a review and analysis of the research that has been carried out on dynamic calibration for optical-fiber solids concentration probes. An introduction to the optical-fiber solids concentration probe was given. Different calibration methods of optical-fiber solids concentration probes reported in the literature were reviewed. In addition, a reflection-type optical-fiber solids concentration probe was uniquely calibrated at nearly full range of the solids concentration from 0 to packed bed concentration. The effects of particle properties (particle size, sphericity and color) on the calibration results were comprehensively investigated. The results show that the output voltage has a tendency to increase with the decreasing particle size, and the effect of particle color on calibration result is more predominant than that of sphericity. PMID:23867745

Taylor dispersion in wind-driven current

NASA Astrophysics Data System (ADS)

Li, Gang; Wang, Ping; Jiang, Wei-Quan; Zeng, Li; Li, Zhi; Chen, G. Q.

2017-12-01

Taylor dispersion associated with wind-driven currents in channels, shallow lakes and estuaries is essential to hydrological environmental management. For solute dispersion in a wind-driven current, presented in this paper is an analytical study of the evolution of concentration distribution. The concentration moments are intensively derived for an accurate presentation of the mean concentration distribution, up to the effect of kurtosis. The vertical divergence of concentration is then deduced by Gill's method of series expansion up to the fourth order. Based on the temporal evolution of the vertical concentration distribution, the dispersion process in the wind-driven current is concretely characterized. The uniform shear leads to a special symmetrical distribution of mean concentration free of skewness. The non-uniformity of vertical concentration is caused by convection and smeared out gradually by the effect of diffusion, but fails to disappear even at large times.

Effect of thiopental sodium on N-methyl-D-aspartate-gated currents.

PubMed

Liu, Hongliang; Dai, Tijun; Yao, Shanglong

2006-05-01

N-methyl-D-aspartate (NMDA) receptors in the prefrontal cortex (PFC) are closely related with the excitability of pyramidal neurons and PFC function. As the effect of thiopental sodium on the central nervous system may partly result from the inhibition of PFC NMDA receptors, we investigated the effect of thiopental sodium with different concentrations on NMDA-gated currents in acutely dissociated rat PFC pyramidal neurons. We sought to determine whether thiopental sodium inhibits NMDA receptor function. Three to four week old male Sprague-Dawley rats were sacrificed and the PFC was dissected. Pyramidal neurons from the PFC were prepared and standard whole-cell patch clamp recordings were performed. Escalating concentrations from 3-1000 microM NMDA were applied 100 microm from the pyramidal cells, and the concentration in the effect compartment related to 50% effect (EC50) of NMDA was determined for the ensuing experiments. One hundred microM NMDA alone (control) or NMDA with different concentrations (10-1000 microM) of thiopental sodium were applied. After the inhibitory concentration, in 50% of NMDA effect (IC50) of thiopental sodium was established this IC50 and NMDA 3-1000 microM were applied 100 microm from the pyramidal cells. The EC50 value of NMDA under the effect of IC50 thiopental sodium was determined. N-methyl-D-aspartate induced inward currents in a concentration-dependent manner, which were completely antagonized by 50 microM AP5. The maximal amplitude of NMDA-induced current was 1.15 +/- 0.27 nA. The EC50 of NMDA was 53.6 +/- 12.4 microM. The NMDA (100 microM)-gated current was inhibited by thiopental sodium in a concentration-dependent manner, and the IC50 of thiopental sodium was 33.6 +/- 6.1 microM. Under the effect of 33.6 microM thiopental sodium, the maximal amplitude of NMDA-induced current was 0.87 +/- 0.17 nA. The concentration-response curve of NMDA was shifted rightwards. The EC50 of NMDA was 128 +/- 15 microM, which was greater than that of NMDA without thiopental sodium (P < 0.01). Thiopental sodium decreases NMDA-gated currents in acutely dissociated rat prefrontal cortical pyramidal neurons in a concentration-dependent manner.

The effects of the pollutant, sodium cyanide, on the morphology and physiology of oedogonium cardiacum

NASA Technical Reports Server (NTRS)

Sparks, E.

1977-01-01

OEDOGONIUM cardiacum exposed to varying concentrations of sodium cyanide for 15 day periods exhibited both morphological and physiological alterations. Organisms were exposed to the pollutant in concentrations of 1, 10, 25, 50, and 100 parts per million. Exposure period for organisms in each concentration was 15 days. As the concentration of the pollutant increased fragmentation also increased. Exposure also caused organisms to lose chlorophyll. The third morphological alteration was the incidence of rupture. Physiological effects altered by exposure included: reduced oxygen evolution, retardation of starch production and death. Death occurs when organisms are exposed to high concentrations over the total 15 day period.

Effect of dissolved aromatic hydrocarbons on the growth of marine bacteria in batch culture.

PubMed Central

Calder, J A; Lader, J H

1976-01-01

Dissolved aromatic hydrocarbons were found to decrease growth rate and maximum cell density of marine bacteria in batch cultures. The magnitude of the decrement was observed to be a function of concentration of the hydrocarbon and inherent toxicity. The inherent toxicity was observed to increase inversely with solubility such that naphthalene at 100 muM concentration demonstrated a toxic effect similar to benzopyrene at 0.02 muM. A partial oxidation product of naphthalene was found to be more effective in decreasing growth parameters than naphthalene at equivalent concentrations and to cause complete cessation of growth at the higher concentrations permitted by its polar structure. PMID:970939

Protective effects of selenium on mercury induced immunotoxic effects in mice by way of concurrent drinking water exposure.

PubMed

Li, Xuan; Yin, Daqiang; Li, Jiang; Wang, Rui

2014-07-01

Selenium (Se) has been recognized as one key to understanding mercury (Hg) exposure risks. To explore the effects of Se on Hg-induced immunotoxicity, female Balb/c mice were exposed to HgCl2- or MeHgCl-contaminated drinking water (0.001, 0.01, and 0.1 mM as Hg) with coexisting Na2SeO3 at different Se/Hg molar ratios (0:1, 1/3:1, 1:1 and 3:1). The potential immunotoxicity induced by Na2SeO3 exposure alone (by way of drinking water) was also determined within a wide range of concentrations. After 14 days' exposure, the effects of Hg or Se on the immune system of Balb/c mice were investigated by determining the proliferation of T and B lymphocytes and the activity of natural killer cells. Hg exposure alone induced a dose-dependent suppression effect, whereas Se provided promotion effects at low exposure level (<0.01 mM) and inhibition effects at high exposure level (>0.03 mM). Under Hg and Se coexposure condition, the effects on immunotoxicity depended on the Hg species, Se/Hg ratio, and exposure concentration. At low Hg concentration (0.001 mM), greater Se ingestion exhibited stronger protective effects on Hg-induced suppression effect mainly by way of decreasing Hg concentrations in target organs. At greater Hg concentration (0.01 and 0.1 mM), immunotoxicity induced by Se (>0.03 mM) became evident, and the protective effects appeared more significant at an Se/Hg molar ratio of 1:1. The complex antagonistic effects between Se and Hg suggested that both Se/Hg molar ratio and concentration should be considered when evaluating the potential health risk of Hg-contaminated biota.

Effects of Learning Styles and Interest on Concentration and Achievement of Students in Mobile Learning

ERIC Educational Resources Information Center

Li, Xiaojie; Yang, Xianmin

2016-01-01

Learning concentration deserves in-depth investigation in the field of mobile learning. Therefore, this study examined the interaction effects of learning styles and interest on the learning concentration and academic achievement of students who were asked to learn conceptual knowledge via their mobile phones in a classroom setting. A total of 92…

Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly:A randomized double-blind placebo-controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve serum zinc concentrations and immunity of nursing home elderly with low serum zinc concentration. Objective: We aimed to determine the effect of ...

The Effect of Concentric Isokinetic Strength Training of the Quadriceps Femoris on Electromyography and Muscle Strength in the Trained and Untrained Limb.

ERIC Educational Resources Information Center

Evetovich, Tammy K.; Housh, Terry J.; Housh, Dona J.; Johnson, Glen O.; Smith, Douglas B.; Ebersole, Kyle T.

2001-01-01

Examined the effects of unilateral concentric isokinetic leg extension training on peak torque and electromyographic (EMG) responses in trained and untrained limbs. Adult men participated in training and control groups. Overall, unilateral concentric isokinetic strength training induced strength increases in trained as well as untrained limbs.…

Effects of synthetic gestagens on fish reproduction.

PubMed

Zeilinger, Jana; Steger-Hartmann, Thomas; Maser, Edmund; Goller, Stephan; Vonk, Richardus; Länge, Reinhard

2009-12-01

Although it is well known that estrogenic steroidal hormones are able to affect the sexual development and reproduction of fish at low concentrations, no data on environmental effects of the class of progestogenic hormones are available yet. Synthetic gestagens (progestins) are a component in oral contraceptives. Upon their use, a fraction of the progestins will be excreted via urine into the aquatic environment. On the basis of their pharmacological action in mammals, it is supposed that fish reproduction is the most sensitive endpoint for the progestin treatment. In order to test this assumption, the effects of two progestins currently marketed in contraceptive formulations, levonorgestrel (LNG) and drospirenone (DRSP), were investigated in adult fathead minnows (Pimephales promelas) following an Organization for Economic Cooperation and Development 21-d fish reproduction screening assay draft protocol with additional end points. Levonorgestrel was tested at measured concentrations of 0.8, 3.3, and 29.6 ng/L, and DRSP at concentrations of 0.66, 6.5, and 70 microg/L. Both tested progestins caused an inhibition of reproduction. For LNG, this occurred at concentrations of >or=0.8 ng/L, no no-observed-effect concentration (NOEC) could be defined. Higher concentrations resulted in masculinization of females with de novo synthesis of nuptial tubercles. Drospirenone treatment, however, affected the reproductive success of fathead minnow at concentrations of 6.5 microg/L and higher with a clear dose-response relationship and a NOEC of 0.66 microg/L, which is above environmentally relevant concentrations.

Application of a Physiologically Based Pharmacokinetic Model to Predict OATP1B1-Related Variability in Pharmacodynamics of Rosuvastatin

PubMed Central

Rose, R H; Neuhoff, S; Abduljalil, K; Chetty, M; Rostami-Hodjegan, A; Jamei, M

2014-01-01

Typically, pharmacokinetic–pharmacodynamic (PK/PD) models use plasma concentration as the input that drives the PD model. However, interindividual variability in uptake transporter activity can lead to variable drug concentrations in plasma without discernible impact on the effect site organ concentration. A physiologically based PK/PD model for rosuvastatin was developed that linked the predicted liver concentration to the PD response model. The model was then applied to predict the effect of genotype-dependent uptake by the organic anion-transporting polypeptide 1B1 (OATP1B1) transporter on the pharmacological response. The area under the plasma concentration–time curve (AUC0–∞) was increased by 63 and 111% for the c.521TC and c.521CC genotypes vs. the c.521TT genotype, while the PD response remained relatively unchanged (3.1 and 5.8% reduction). Using local concentration at the effect site to drive the PD response enabled us to explain the observed disconnect between the effect of the OATP1B1 c521T>C polymorphism on rosuvastatin plasma concentration and the cholesterol synthesis response. PMID:25006781

Hydraulic effects in a radiative atmosphere with ionization

NASA Astrophysics Data System (ADS)

Bhat, P.; Brandenburg, A.

2016-03-01

Context. In his 1978 paper, Eugene Parker postulated the need for hydraulic downward motion to explain magnetic flux concentrations at the solar surface. A similar process has also recently been seen in simplified (e.g., isothermal) models of flux concentrations from the negative effective magnetic pressure instability (NEMPI). Aims: We study the effects of partial ionization near the radiative surface on the formation of these magnetic flux concentrations. Methods: We first obtain one-dimensional (1D) equilibrium solutions using either a Kramers-like opacity or the H- opacity. The resulting atmospheres are then used as initial conditions in two-dimensional (2D) models where flows are driven by an imposed gradient force that resembles a localized negative pressure in the form of a blob. To isolate the effects of partial ionization and radiation, we ignore turbulence and convection. Results: Because of partial ionization, an unstable stratification always forms near the surface. We show that the extrema in the specific entropy profiles correspond to the extrema in the degree of ionization. In the 2D models without partial ionization, strong flux concentrations form just above the height where the blob is placed. Interestingly, in models with partial ionization, such flux concentrations always form at the surface well above the blob. This is due to the corresponding negative gradient in specific entropy. Owing to the absence of turbulence, the downflows reach transonic speeds. Conclusions: We demonstrate that, together with density stratification, the imposed source of negative pressure drives the formation of flux concentrations. We find that the inclusion of partial ionization affects the entropy profile dramatically, causing strong flux concentrations to form closer to the surface. We speculate that turbulence effects are needed to limit the strength of flux concentrations and homogenize the specific entropy to a stratification that is close to marginal.

A pentanucleotide repeat polymorphism in the 5' control region of the apolipoprotein(a) gene is associated with lipoprotein(a) plasma concentrations in Caucasians.

PubMed Central

Trommsdorff, M; Köchl, S; Lingenhel, A; Kronenberg, F; Delport, R; Vermaak, H; Lemming, L; Klausen, I C; Faergeman, O; Utermann, G

1995-01-01

The enormous interindividual variation in the plasma concentrations of the atherogenic lipoprotein(a) [Lp(a)] is almost entirely controlled by the apo(a) locus on chromosome 6q26-q27. A variable number of transcribed kringle4 repeats (K4-VNTR) in the gene explains a large fraction of this variation, whereas the rest is presently unexplained. We here have analyzed the effect of the K4-VNTR and of a pentanucleotide repeat polymorphism (TTTTA)n (n = 6-11) in the 5' control region of the apo(a) gene on plasma Lp(a) levels in unrelated healthy Tyroleans (n = 130), Danes (n = 154), and Black South Africans (n = 112). The K4-VNTR had a significant effect on plasma Lp(a) levels in Caucasians and explained 41 and 45% of the variation in Lp(a) plasma concentration in Tyroleans and Danes, respectively. Both, the pentanucleotide repeat (PNR) allele frequencies and their effects on Lp(a) concentrations were heterogeneous among populations. A significant negative correlation between the number of pentanucleotide repeats and the plasma Lp(a) concentration was observed in Tyroleans and Danes. The effect of the 5' PNRP on plasma Lp(a) concentrations was independent from the K4-VNTR and explained from 10 to 14% of the variation in Lp(a) concentrations in Caucasians. No significant effect of the PNRP was present in Black Africans. This suggests allelic association between PNR alleles and sequences affecting Lp(a) levels in Caucasians. Thus, in Caucasians but not in Blacks, concentrations of the atherogenic Lp(a) particle are strongly associated with two repeat polymorphisms in the apo(a) gene. Images PMID:7615785

[Short-term responses of foliar multi-element stoichiometry and nutrient resorption of slash pine to N addition in subtropical China].

PubMed

Chen, Wei Wei; Kou, Liang; Jiang, Lei; Gao, Wen Long; Yang, Hao; Wang, Hui Min; Li, Sheng Gong

2017-04-18

We conducted a field experiment with three levels of N addition (0, 40 and 120 kg N·hm -2 ·a -1 ) in a Pinus elliottii plantation in subtropical China and collected green and senesced needles of P. elliottii at the peak (July) and the end (October) of each growing season in 2014 and 2015 for clarifying effects of nitrogen additions on concentrations of nine elements (C, N, P, K, Ca, Mg, Al, Fe and Mn) in the green and senesced needles and their corresponding resorption efficiency and resorption proficiency. Our results showed that N addition had positive effects on concentrations of N, Al and Mn, negative effects on the P concentration and the Ca concentration in 2014, and neutral effects on concentrations of C, K, Mg and Fe in green needles. N addition signifi-cantly increased foliar N/P. These stoichiometric responses were N level-dependent (stronger at high N rate). N addition significantly decreased N resorption efficiency in 2015 and increased that of K in 2014. Compared with the resorption efficiency, resorption proficiency responded more strongly to increased available N. N addition significantly decreased resorption proficiency of N, and increased that of P, K, and the concentration of Fe in senesced needles, however, there were no significant effects on the concentrations of Ca, Mg, Al and Mn in senesced needles. We concluded that responses of foliar stoichiometry to N addition were element-specific, and plants might cope with changing environments via adjusting internal nutrient cycle (resorption). The elevated foliar N/P and K/P suggested a shift from N and P co-limitation to P limitation with N additions, and increased concentrations of Al and Mn might imply potential toxicity of metal ions to P. elliottii.

Environmental risk assessment of three selective serotonin reuptake inhibitors in the aquatic environment: a case study including a cocktail scenario.

PubMed

Styrishave, Bjarne; Halling-Sørensen, Bent; Ingerslev, Flemming

2011-01-01

We present an environmental risk assessment of three selective serotonin reuptake inhibitors (SSRIs; citalopram, sertraline, and fluoxetine) in the aquatic environment based on two case scenarios. Abiotic and biotic degradation experiments and sorption estimates were used to predict environmental concentrations of three SSRIs from the wastewater of two psychiatric hospitals, the primary sector, and wastewater entering and leaving wastewater treatment plants (WWTPs). Assuming a sewage treatment retention time of 8 h, abiotic degradation was low, for all three SSRIs inhibitors, ranging between 0 and 2% for hydrolysis and 0 and 6% for photolysis. The biodegradation was also slow, ranging from 0 to 3% within an 8-h period. In untreated sewage, citalopram (CIT) and sertraline (SER) concentrations may be high enough to exert effects on the aquatic biota (CIT: 0.19-10.3 µg/L; SER: 0.14-17.1 µg/L). Removal of the pharmaceuticals is due primarily to sorption in the WWTP. Sertraline was estimated to have the highest concentrations in the sewage effluents, 4.4 and 19.9 ng/L for the two cases, respectively. In treated wastewater, individual SSRI concentrations are probably too low to exert effects on biota. By using concentration addition, a cocktail exposure scenario was estimated. The predicted concentration in the biota calculated from the cocktail effect was 0.05 and 0.16 nmol/g for the two cases, respectively, and SER was found to give the highest contribution to this cocktail effect. The results indicate that the concentrations in the wastewater effluents are one to two orders of magnitude lower than the concentrations likely to cause an effect in the aquatic biota. © 2010 SETAC.

Effect of dietary calcium concentrations in low non-phytate phosphorus diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis incidence in growing broiler chickens.

PubMed

Kim, Jong Hyuk; Jung, Hyunjung; Pitargue, Franco Martinez; Han, Gi Ppeum; Choi, Hyeon Seok; Kil, Dong Yong

2017-07-01

An experiment was conducted to investigate the effect of dietary Ca concentrations in low non-phytate phosphorus (NPP) diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis (FPD) incidence in growing broiler chickens. A total of 1,800 21-day-old Ross 308 growing broiler chickens were allotted to 1 of 6 dietary treatments with 6 replicated cages. Six diets were formulated to provide increasing Ca concentrations of 4.0, 5.0, 6.0, 7.0, 8.0, or 9.0 g/kg in diets. The concentrations of NPP in all diets were maintained at 3.0 g/kg, and phytase was supplemented to all diets at the level of 1,000 fytase units (FTU)/kg. At the end of the 14-d feeding trial, birds were euthanized for tibia sampling, and litter samples were collected from 3 areas in the cage. The FPD incidence was measured based on a 6-point scoring system. Dietary Ca concentrations had no effect on growth performance of growing broiler chickens. However, a tendency (linear, p = 0.05) for decreased feed efficiency was observed as dietary Ca concentrations were increased. The concentrations of Ca and P in the tibia of broiler chickens increased (linear and quadratic, p<0.01) with increasing Ca concentrations in low NPP diets containing phytase. Litter pH, moisture, and N contents were not affected by increasing Ca concentrations in low NPP diets containing phytase. However, a tendency (quadratic, p = 0.10) for increased FPD incidence with increasing dietary Ca concentrations was observed. Dietary Ca concentrations from 4.0 to 9.0 g/kg in low NPP diets containing phytase have little effects on growth performance of growing broiler chickens. However, Ca and P concentrations in the tibia are decreased if dietary Ca concentrations are less than 5.0 g/kg. The FPD incidence for growing broiler chickens may be decreased if less than 9.0 g/kg of Ca is included in diets.

The Effect of Different Carbapenem Antibiotics (Ertapenem, Imipenem/Cilastatin, and Meropenem) on Serum Valproic Acid Concentrations.

PubMed

Wu, Chien-Chih; Pai, Tsung-Yu; Hsiao, Fei-Yuan; Shen, Li-Jiuan; Wu, Fe-Lin Lin

2016-10-01

Carbapenem antibiotics (CBPMs) may significantly reduce the serum concentration of valproic acid (VPA), but the extent of this effect among various CBPMs is unknown. This study compared the extent and onset of the interactions among ertapenem, imipenem/cilastatin, and meropenem. A 5-year retrospective study was performed. Hospitalized patients over 18 years old who received VPA and a CBPM concurrently were enrolled via the pharmacy computer system. Patients who lacked VPA serum concentration measurements before or during CBPMs' use, had concurrent medication(s) that might interfere with VPA metabolism, or had a history of liver cirrhosis were excluded. Total VPA serum concentrations before and during CBPMs' use and after its discontinuation were recorded, and differences among various CBPMs were analyzed. Fifty-two patients were included in this analysis. Irrespective of the route of administration, VPA serum concentrations were subtherapeutic in 90% of the subjects during CBPMs' use. There was a significant decrease (P < 0.001) in VPA serum concentrations during the use of CBPMs: 72% ± 17%, 42% ± 22%, and 67% ± 19% in the ertapenem (N = 9), imipenem/cilastatin (N = 17), and meropenem (N = 26) groups, respectively. The effect of ertapenem and meropenem on VPA was significantly more expressed than that of imipenem/cilastatin (P < 0.005). The onset of this drug interaction occurred within 24 hours of CBPMs' administration, and VPA serum concentrations returned to 90% of baseline within 7 days of CBPMs' discontinuation along with a 20% increase in VPA dose. Increasing VPA dose during the use of ertapenem or meropenem did not result in elevating VPA serum concentrations to therapeutic levels during the combined therapy period. CBPMs reduced VPA serum concentration within 24 hours of administration by approximately 60%. Ertapenem and meropenem had a greater effect on VPA serum concentration than imipenem/cilastatin. Because of the dramatic reduction of VPA serum concentration during CBPMs' use, concomitant use of VPA and CBPMs should be avoided.

Effects of pioglitazone on cardiac ion currents and action potential morphology in canine ventricular myocytes.

PubMed

Kistamás, Kornél; Szentandrássy, Norbert; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Bárándi, László; Horváth, Balázs; Szebeni, Andrea; Magyar, János; Bányász, Tamás; Kecskeméti, Valéria; Nánási, Péter P

2013-06-15

Despite its widespread therapeutical use there is little information on the cellular cardiac effects of the antidiabetic drug pioglitazone in larger mammals. In the present study, therefore, the concentration-dependent effects of pioglitazone on ion currents and action potential configuration were studied in isolated canine ventricular myocytes using standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques. Pioglitazone decreased the maximum velocity of depolarization and the amplitude of phase-1 repolarization at concentrations ≥3 μM. Action potentials were shortened by pioglitazone at concentrations ≥10 μM, which effect was accompanied with significant reduction of beat-to-beat variability of action potential duration. Several transmembrane ion currents, including the transient outward K(+) current (Ito), the L-type Ca(2+) current (ICa), the rapid and slow components of the delayed rectifier K(+) current (IKr and IKs, respectively), and the inward rectifier K(+) current (IK1) were inhibited by pioglitazone under conventional voltage clamp conditions. Ito was blocked significantly at concentrations ≥3 μM, ICa, IKr, IKs at concentrations ≥10 μM, while IK1 at concentrations ≥30 μM. Suppression of Ito, ICa, IKr, and IK1 has been confirmed also under action potential voltage clamp conditions. ATP-sensitive K(+) current, when activated by lemakalim, was effectively blocked by pioglitazone. Accordingly, action potentials were prolonged by 10 μM pioglitazone when the drug was applied in the presence of lemakalim. All these effects developed rapidly and were readily reversible upon washout. In conclusion, pioglitazone seems to be a harmless agent at usual therapeutic concentrations. Copyright © 2013 Elsevier B.V. All rights reserved.

Decontamination Options for Bacillus anthracis-Contaminated Drinking Water Determined from Spore Surrogate Studies ▿

PubMed Central

Raber, Ellen; Burklund, Alison

2010-01-01

Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination alternatives for use in a contaminated drinking water supply. The parameters were as follows: (i) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus), (ii) spore concentration in suspension (102 and 106 spores/ml), (iii) chemical characteristics of the decontaminant (sodium dichloro-S-triazinetrione dihydrate [Dichlor], hydrogen peroxide, potassium peroxymonosulfate [Oxone], sodium hypochlorite, and VirkonS), (iv) decontaminant concentration (0.01% to 5%), and (v) exposure time to decontaminant (10 min to 1 h). Results from 138 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5% and Dichlor or sodium hypochlorite at a concentration of 2% were highly effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and a more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting the EPA biocide standard of greater than a 6-log kill after a 10-min exposure time and at lower concentrations than typically reported for biocide use. Solutions of 5% VirkonS and Oxone were less effective as decontaminants than other options evaluated in this study and did not meet the EPA's efficacy standard for a biocide, although they were found to be as effective for concentrations of 102 spores/ml. Differences in methods and procedures reported by other investigators make quantitative comparisons among studies difficult. PMID:20709855

Two Different Concentrations of Ketofol for Procedural Sedation and Analgesia in Closed Reduction of Nasal Fracture.

PubMed

Ayatollahi, Vida; Vafaiyan, Maryam; Hatami, Maryam; Behdad, Shekoufeh

2016-06-01

Ketofol is a mixture of propofol and ketamine in various concentrations. It is accepted as a suitable combination in procedural sedation and analgesia. The mixture of propofol and ketamine with different respiratory and hemodynamic effects may result in fewer dose-related side effects and a probable synergistic effect. This study was designed to compare the adverse effects and quality of analgesia of 2 different intravenous concentrations of ketofol in patients undergoing closed reduction of the nose. This randomized double-blinded study was conducted on 100 patients who underwent closed reduction of nose. The patients were divided into 2 groups of 50, and received either a combination of propofol/ketamine (1:1) (Group I) or propofol/ketamine (3:1) (Group II). Hemodynamic changes, including systolic blood pressure, diastolic blood pressure, heart rate and O2sat, and side effects such as hallucination, vomiting, coughing and apnea, were recorded. Data analysis showed that the demographic characteristics (age, height, and weight) were similar in 2 groups, and there were no significant differences between the 2 groups. There was no significant hemodynamic change between both groups. However, there was a decrease in hallucination and vomiting in the group that received higher concentration of ketofol (ketamine/propofol of 1:3). There was no significant hemodynamic change between both groups that received concentrations of 1:1 and 3:1 propofol /ketamine. However, there was a reduction in hallucination, vomiting, and recovery duration in the group that received higher concentration of propofol. In conclusion, increasing the concentration of propofol can be useful with fewer side effects and lower duration of recovery.

A low-dose atorvastatin and losartan combination directly improves aortic ring relaxation and diminishes ischaemic-reperfusion injury in isolated rat hearts

PubMed Central

Lunder, Mojca; Janić, Miodrag; Žiberna, Lovro; Drevenšek, Gorazd; Šabovič, Mišo

2012-01-01

Summary Background The cardiovascular pleiotropic effects of statins and angiotensin receptor blockers (ARBs) could be of interest for innovative preventive approaches. We aimed to investigate whether low-dose atorvastatin and losartan, separately not possessing protective cardiovascular pleiotropic effects, express them when combined. Material/Methods Forty-five adult male Wistar rats were anaesthetized and their thoracic aortas and hearts were isolated. Relaxation of aortic rings, coronary flow rate and the extent of myocardial ischaemic-reperfusion injury were measured. Different concentrations (0.01, 0.1, 1.0 μM) of atorvastatin and losartan added to a perfusion medium were first tested. The separate drugs, which were ineffective, were then combined at the same concentrations and the concentration was tested in the same model. Results Low concentrations of atorvastatin or losartan (0.1 and 1 μM, respectively) produced no effects in isolated aorta. However, surprisingly, when these drug concentrations were combined, a significantly improved endothelium-dependent relaxation of the thoracic aorta was observed. Similarly, when combining individually ineffective concentrations of atorvastatin or losartan (0.01 and 0.1 μM, respectively), significantly increased coronary flow and a decreased extent of myocardial injury were observed. By using a nitric oxide-synthase inhibitor, we demonstrated that the vasodilatory effects obtained were nitric oxide-dependent. The degree of effectiveness by the combination was comparable to that obtained by 10-fold (atorvastatin) or 100-fold (losartan) higher concentrations of the separate drugs. Conclusions Our results revealed that remarkable additive/synergistic effects exist between low-doses of a statin (atorvastatin) and an ARB (losartan), resulting in important cardiovascular protection. This new concept could be valuable in cardiovascular prevention. PMID:22936187

Comparison of changes in the extracellular concentration of noradrenaline in rat frontal cortex induced by sibutramine or d-amphetamine: modulation by α2-adrenoceptors

PubMed Central

Wortley, K E; Hughes, Z A; Heal, D J; Stanford, S C

1999-01-01

The effects of sibutramine (0.25–10 mg kg−1, i.p.) on extracellular noradrenaline concentration in the frontal cortex of halothane-anaesthetized rats were compared with those of d-amphetamine (1–3 mg kg−1, i.p.) using in vivo microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of these drugs on extracellular noradrenaline concentration were also investigated by pretreating rats with the selective α2-adrenoceptor antagonist, RX821002.Sibutramine induced a gradual and sustained increase in extracellular noradrenaline concentration. The dose-response relationship was described by a bell-shaped curve with a maximum effect at 0.5 mg kg−1. In contrast, d-amphetamine induced a rapid increase in extracellular noradrenaline concentration, the magnitude of which paralleled drug dose.Pretreatment with the α2-adrenoceptor antagonist, RX821002 (dose 3 mg kg−1, i.p.) increased by 5 fold the accumulation of extracellular noradrenaline caused by sibutramine (10 mg kg−1) and reduced the latency of sibutramine to reach its maximum effect from 144–56 min.RX821002-pretreatment increased by only 2.5 fold the increase in extracellular noradrenaline concentration caused by d-amphetamine alone (10 mg kg−1) and had no effect on the latency to reach maximum.These findings support evidence that sibutramine acts as a noradrenaline uptake inhibitor in vivo and that the effects of this drug are blunted by indirect activation of presynaptic α2-adreno-ceptors. In contrast, the rapid increase in extracellular noradrenaline concentration induced by d-amphetamine is consistent with this being mainly due to an increase in Ca2+-independent release of noradrenaline. PMID:10482917

From the depletion attraction to the bridging attraction: the effect of solvent molecules on the effective colloidal interactions.

PubMed

Chen, Jie; Kline, Steven R; Liu, Yun

2015-02-28

Depletion attraction induced by non-adsorbing polymers or small particles in colloidal solutions has been widely used as a model colloidal interaction to understand aggregation behavior and phase diagrams, such as glass transitions and gelation. However, much less attention has been paid to study the effective colloidal interaction when small particles/molecules can be reversibly attracted to large colloidal particles. At the strong attraction limit, small particles can introduce bridging attraction as it can simultaneously attach to neighbouring large colloidal particles. We use Baxter's multi-component method for sticky hard sphere systems with the Percus-Yevick approximation to study the bridging attraction and its consequence to phase diagrams, which are controlled by the concentration of small particles and their interaction with large particles. When the concentration of small particles is very low, the bridging attraction strength increases very fast with the increase of small particle concentration. The attraction strength eventually reaches a maximum bridging attraction (MBA). Adding more small particles after the MBA concentration keeps decreasing the attraction strength until reaching a concentration above which the net effect of small particles only introduces an effective repulsion between large colloidal particles. These behaviors are qualitatively different from the concentration dependence of the depletion attraction on small particles and make phase diagrams very rich for bridging attraction systems. We calculate the spinodal and binodal regions, the percolation lines, the MBA lines, and the equivalent hard sphere interaction line for bridging attraction systems and have proposed a simple analytic solution to calculate the effective attraction strength using the concentrations of large and small particles. Our theoretical results are found to be consistent with experimental results reported recently.

Extracellular Ca(2+)-dependent enhancement of cytocidal potency of zoledronic acid in human oral cancer cells.

PubMed

Inoue, Sayaka; Arai, Naoya; Tomihara, Kei; Takashina, Michinori; Hattori, Yuichi; Noguchi, Makoto

2015-08-15

Direct antitumor effects of bisphosphonates (BPs) have been demonstrated in various cancer cells in vitro. However, the effective concentrations of BPs are typically much higher than their clinically relevant concentrations. Oral cancers frequently invade jawbone and may lead to the release of Ca(2+) in primary lesions. We investigated the effects of the combined application of zoledronic acid (ZA) and Ca(2+) on proliferation and apoptosis of oral cancer cells. Human oral cancer cells, breast cancer cells, and colon cancer cells were treated with ZA at a wide range of concentrations in different Ca(2+) concentration environments. Under a standard Ca(2+) concentration (0.6mM), micromolar concentrations of ZA were required to inhibit oral cancer cell proliferation. Increasing extracellular Ca(2+) concentrations greatly enhanced the potency of the ZA cytocidal effect. The ability of Ca(2+) to enhance the cytocidal effects of ZA was negated by the Ca(2+)-selective chelator EGTA. In contrast, the cytocidal effect of ZA was less pronounced in breast and colon cancer cells regardless of whether extracellular Ca(2+) was elevated. In oral cancer cells incubated with 1.6mM Ca(2+), ZA up-regulated mitochondrial Bax expression and increased mitochondrial Ca(2+) uptake. This was associated with decreased mitochondrial membrane potential and increased release of cytochrome c. We suggest that ZA can specifically produce potent cytocidal activity in oral cancer cells in an extracellular Ca(2+)-dependent manner, implying that BPs may be useful for treatment of oral squamous cell carcinoma with jawbone invasion leading to the hypercalcemic state. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)*

PubMed Central

La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

2009-01-01

The effects of CO2 enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L, elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition. PMID:19489111

Genistein effects on stromal cells determines epithelial proliferation in endometrial co-cultures.

PubMed

Sampey, Brante P; Lewis, Terrence D; Barbier, Claire S; Makowski, Liza; Kaufman, David G

2011-06-01

Estrogen is the leading etiologic factor for endometrial cancer. Estrogen-induced proliferation of endometrial epithelial cells normally requires paracrine growth factors produced by stromal cells. Epidemiologic evidence indicates that dietary soy prevents endometrial cancer, and implicates the phytoestrogen genistein in this effect. However, results from previous studies are conflicting regarding the effects of genistein on hormone responsive cancers. The effects of estrogen and genistein on proliferation of Ishikawa (IK) endometrial adenocarcinoma cells were examined in co-cultures of IK cells with endometrial stromal cells, recapitulating the heterotypic cell-to-cell interactions observed in vivo. The roles of estrogen receptor (ER)α and ERβ were evaluated using ERα and ERβ specific agonists. ER activation and cell proliferation in the IK epithelial cells were determined by alkaline phosphatase assay and Coulter counter enumeration, respectively. Both estrogen and genistein increased estrogen receptor-induced gene activity in IK cells over a range of concentrations. Estrogen alone but not genistein increased IK proliferation in co-cultures. When primed by estrogen treatment, increasing concentrations of genistein produced a biphasic effect on IK proliferation: nM concentrations inhibited estrogen-induced proliferation while μM concentrations increased proliferation. Studies with an ERβ-specific agonist produced similar results. Genistein did not influence the effects of estrogen on IK proliferation in monoculture. Our study indicates that nutritionally relevant concentrations (nM) of genistein inhibit the proliferative effects of estrogen on endometrial adenocarcinoma cells presumably through activation of stromal cell ERβ. We believe that sub-micromolar concentrations of genistein may represent a novel adjuvant for endometrial cancer treatment and prevention. Copyright © 2011 Elsevier Inc. All rights reserved.

The Effect of CuO Nanoparticles on Antimicrobial Effects and Shear Bond Strength of Orthodontic Adhesives

PubMed Central

Toodehzaeim, Mohammad Hossein; Zandi, Hengameh; Meshkani, Hamidreza; Hosseinzadeh Firouzabadi, Azadeh

2018-01-01

Statement of the Problem: Orthodontic appliances facilitate microbial plaque accumulation and increase the chance of white spot lesions. There is a need for new plaque control methods independent of patient's cooperation. Purpose: The aim of this study was to determine the effects of incorporating copper oxide (CuO) nanoparticles on antimicrobial properties and bond strength of orthodontic adhesive. Materials and Method: CuO nanoparticles were added to the composite transbond XT at concentrations of 0.01, 0.5 and 1 wt.%. To evaluate the antimicrobial properties of composites containing nanoparticles, the disk agar diffusion test was used. For this purpose, 10 discs from each concentration of nano-composites (totally 30 discs) and 10 discs from conventional composite (as the control group) were prepared. Then the diameter of streptococcus mutans growth inhibition around each disc was determined in blood agar medium. To evaluate the shear bond strength, with each concentration of nano-composites as well as the control group (conventional composite), 10 metal brackets were bonded to the human premolars and shear bond strength was determined using a universal testing machine. Results: Nano-composites in all three concentrations showed significant antimicrobial effect compared to the control group (p< 0.001). With increasing concentration of nanoparticles, antimicrobial effect showed an upward trend, although statistically was not significant. There was no significant difference between the shear bond strength of nano-composites compared to control group (p= 0.695). Conclusion: Incorporating CuO nanoparticles into adhesive in all three studied concentrations added antimicrobial effects to the adhesive with no adverse effects on shear bond strength. PMID:29492409

The Effect of CuO Nanoparticles on Antimicrobial Effects and Shear Bond Strength of Orthodontic Adhesives.

PubMed

Toodehzaeim, Mohammad Hossein; Zandi, Hengameh; Meshkani, Hamidreza; Hosseinzadeh Firouzabadi, Azadeh

2018-03-01

Orthodontic appliances facilitate microbial plaque accumulation and increase the chance of white spot lesions. There is a need for new plaque control methods independent of patient's cooperation. The aim of this study was to determine the effects of incorporating copper oxide (CuO) nanoparticles on antimicrobial properties and bond strength of orthodontic adhesive. CuO nanoparticles were added to the composite transbond XT at concentrations of 0.01, 0.5 and 1 wt.%. To evaluate the antimicrobial properties of composites containing nanoparticles, the disk agar diffusion test was used. For this purpose, 10 discs from each concentration of nano-composites (totally 30 discs) and 10 discs from conventional composite (as the control group) were prepared. Then the diameter of streptococcus mutans growth inhibition around each disc was determined in blood agar medium. To evaluate the shear bond strength, with each concentration of nano-composites as well as the control group (conventional composite), 10 metal brackets were bonded to the human premolars and shear bond strength was determined using a universal testing machine. Nano-composites in all three concentrations showed significant antimicrobial effect compared to the control group ( p < 0.001). With increasing concentration of nanoparticles, antimicrobial effect showed an upward trend, although statistically was not significant. There was no significant difference between the shear bond strength of nano-composites compared to control group ( p = 0.695). Incorporating CuO nanoparticles into adhesive in all three studied concentrations added antimicrobial effects to the adhesive with no adverse effects on shear bond strength.

Effect-site concentration of remifentanil required to blunt haemodynamic responses during tracheal intubation: A randomized comparison between single- and double-lumen tubes.

PubMed

Kim, Tae Kyong; Hong, Deok Man; Lee, Seo Hee; Paik, Hyesun; Min, Se Hee; Seo, Jeong-Hwa; Jung, Chul-Woo; Bahk, Jae-Hyon

2018-01-01

Objective To investigate the effect-site concentration of remifentanil required to blunt haemodynamic responses during tracheal intubation with a single-lumen tube (SLT) or a double-lumen tube (DLT). Methods Patients scheduled for thoracic surgery requiring one-lung ventilation were randomly allocated to either the SLT or DLT group. All patients received a target-controlled infusion of propofol and a predetermined concentration of remifentanil. Haemodynamic parameters during intubation were recorded. The effect-site concentration of remifentanil was determined using a delayed up-and-down sequential allocation method. Results A total of 92 patients were enrolled in the study. The effective effect-site concentrations of remifentanil required to blunt haemodynamic responses in 50% of patients (EC 50 ) estimated by isotonic regression with bootstrapping was higher in the DLT than the SLT group (8.5 ng/ml [95% confidence interval (CI) 8.0-9.5 ng/ml] versus 6.5 ng/ml [95% CI 5.6-6.7 ng/ml], respectively). Similarly, the effective effect-site concentrations of remifentanil in 95% of patients in the DLT group was higher than the SLT group (9.9 ng/ml [95% CI 9.8-10.0 ng/ml] versus 7.0 ng/ml [95% CI 6.9-7.0 ng/ml], respectively). Conclusions This study demonstrated that a DLT requires a 30% higher EC 50 of remifentanil than does an SLT to blunt haemodynamic responses during tracheal intubation when combined with a target-controlled infusion of propofol. Trial registration Clinicaltrials.gov identifier: NCT01542099.

Study on the DNA-protein crosslinks induced by chromium (VI) in SPC-A1

NASA Astrophysics Data System (ADS)

Liu, Yanqun; Ding, Jianjun; Lu, Xiongbing; You, Hao

2018-01-01

Objective: This study was designed to investigate the effect of chromium (VI) on DNA-protein crosslinks (DPC) of SPC-A1 cells. Methods: We exposed SPC-A1 cells were cultured in 1640 medium and treated with the SPC-A1 cells in vitro to different concentrations of Hexavalent chromium Cr(VI) for 2h, the KC1-SDS precipitation assay were used to measure the DNA-protein cross-linking effect. Results: All the different concentrations of Cr(VI) could cause the increase of DPC coefficient in SPC-A1 cells. But this effect was not significant (P>0.05) at low concentrations; while in high concentration Cr(VI) induced SPC-A1 cells could produce DNA-protein cross-linking effect significantly (P<0.05). Conclusions: chromium (VI) could induce DNA-protein crosslink.

Selective Effects of a Morphine Conjugate Vaccine on Heroin and Metabolite Distribution and Heroin-Induced Behaviors in Rats

PubMed Central

Pravetoni, M.; Harris, A.C.; Birnbaum, A.K.; Pentel, P.R.

2013-01-01

Morphine conjugate vaccines have effectively reduced behavioral effects of heroin in rodents and primates. To better understand how these effects are mediated, heroin and metabolite distribution studies were performed in rats in the presence and absence of vaccination. In non-vaccinated rats 6-monoacetylmorphine (6-MAM) was the predominant opioid in plasma and brain as early as 1 minute after i.v. administration of heroin and for up to 14 minutes. Vaccination with morphine conjugated to keyhole limpet hemocyanin (M-KLH) elicited high titers and concentrations of antibodies with high affinity for heroin, 6-MAM, and morphine. Four minutes after heroin administration vaccinated rats showed substantial retention of all three opioids in plasma compared to controls and reduced 6-MAM and morphine, but not heroin, distribution to brain. Administration of 6-MAM rather than heroin in M-KLH vaccinated rats showed a similar drug distribution pattern. Vaccination reduced heroin-induced analgesia and blocked heroin-induced locomotor activity throughout 2 weeks of repeated testing. Higher serum opioid-specific antibody concentrations were associated with higher plasma opioid concentrations, lower brain 6-MAM and morphine concentrations, and lower heroin-induced locomotor activity. Serum antibody concentrations over 0.2 mg/ml were associated with substantial effects on these measures. These data support a critical role for 6-MAM in mediating the early effects of i.v. heroin and suggest that reducing 6-MAM concentration in brain is essential to the efficacy of morphine conjugate vaccines. PMID:23220743

[Adsorbent effect of activated carbon on small molecular uremic toxin and its influence factors].

PubMed

Yang, Bo; Jiang, Yun-sheng; Li, Jun

2003-06-01

To analyze the adsorbent effect of activated carbon on uremic toxin and its influence factors. Uremic toxins (urea, creatinine and uric acid) were dissolved in the distilled water to obtain uremic toxic solution. Activated carbon was added to the solution, and the concentrations of uremic toxins were measured at different time spots. To determine the influence factors, some possible related materials, such as bile, amino acid, Ringer's, solution of glucose, HCl or NaOH respectively were added simultaneously. The concentrations of toxins in uremic toxic solution decreased 5 min after adding the activated carbon. The concentration of urea was the lowest at 30 min, but it increased after 50 min; while the concentrations of creatinine and uric acid reached the lowest level from 10 to 30 min after adding the activated carbon, and maintained at the same level after that. The bile, amino acid, electrolyte, glucose and pH value did not influence the adsorption of uric acid significantly, but they influenced the adsorption of urea and creatinine. Bile and amino acid influenced the concentration of urea remarkably, following glucose, NaOH and HCl. The effect of pH 2.0 solution on the creatinine concentration was the most significant, following glucose. Activated carbon has adsorptive effect on uremic toxins, but its adsorptive effect decreases as time goes on. Bile, glucose, amino acid, NaOH and HCl can affect the adsorptive effect of activated carbon on uremic toxins to some extent.

Effect of a low dose of sea buckthorn berries on circulating concentrations of cholesterol, triacylglycerols, and flavonols in healthy adults.

PubMed

Larmo, Petra S; Yang, Baoru; Hurme, Saija A M; Alin, Jouni A; Kallio, Heikki P; Salminen, Eeva K; Tahvonen, Raija L

2009-08-01

Epidemiological studies indicate beneficial effects of flavonoids on cardiovascular disease (CVD) risk. To study the effect of flavonoid-rich sea buckthorn berry (SBB) on circulating lipid markers associated with CVD risk and plasma flavonol concentration. Also investigated was whether changes in the circulating flavonol concentrations correlate with the SBB induced changes in C-reactive protein (CRP) concentration observed previously. In all 229 healthy participants completed the randomized double-blind study and consumed daily 28 g of SBB or placebo for 3 months. Fasting blood samples for the analysis of lipid markers and flavonols were obtained at the beginning and end of the study. Compared to the placebo, the consumption of SBB increased the plasma concentration of the flavonols quercetin and isorhamnetin significantly [treatment differences 3.0 ng/ml (P = 0.03) and 3.9 ng/ml (P < 0.01), respectively]. The increase of kaempferol concentration was not significant [treatment difference 0.7 ng/ml (P = 0.08)]. SBB did not affect the serum total, HDL, LDL cholesterol, or the serum triacylglycerol concentrations. There was no correlation between the changes in flavonol and CRP concentrations of participants. The consumption of SBB significantly increased the fasting plasma concentration of quercetin and isorhamnetin indicating that it is a good dietary source of flavonols. However, this did not convert to affecting the circulating concentrations of lipid markers in healthy, normolipidemic adults having healthy diets.

Concentration Dependent Effects of Bovine Serum Albumin on Graphene Oxide Colloidal Stability in Aquatic Environment.

PubMed

Sun, Binbin; Zhang, Yinqing; Chen, Wei; Wang, Kunkun; Zhu, Lingyan

2018-06-22

The impacts of a model globular protein (bovine serum albumin, BSA) on aggregation kinetics of graphene oxide (GO) in aquatic environment were investigated through time-resolved dynamic light scattering at pH 5.5. Aggregation kinetics of GO without BSA as a function of electrolyte concentrations (NaCl, MgCl 2 , and CaCl 2 ) followed the traditional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and the critical coagulation concentration (CCC) was 190, 5.41, and 1.61 mM, respectively. As BSA was present, it affected the GO stability in a concentration dependent manner. At fixed electrolyte concentrations below the CCC values, for example 120 mM NaCl, the attachment efficiency of GO increased from 0.08 to 1, then decreased gradually and finally reached up to zero as BSA concentration increased from 0 to 66.5 mg C/L. The low-concentration BSA depressed GO stability mainly due to electrostatic binding between the positively charged lysine groups of BSA and negatively charged groups of GO, as well as double layer compression effect. With the increase of BSA concentration, more and more BSA molecules were adsorbed on GO, leading to strong steric repulsion which finally predominated and stabilized the GO. These results provided significant information about the concentration dependent effects of natural organic matters on GO stability under environmentally relevant conditions.

Impact of concentration and species of sulfamethoxazole and ofloxacin on their adsorption kinetics on sediments.

PubMed

Wang, Peng; Zhang, Di; Zhang, Huang; Li, Hao; Ghosh, Saikat; Pan, Bo

2017-05-01

Antibiotics are used widely in human and veterinary medicine and are ubiquitous in environmental matrices worldwide. The influence of the concentration of antibiotics on adsorption kinetics is still unclear. This study used sulfamethoxazole (SMX) and ofloxacin (OFL) as adsorbates to investigate the adsorption kinetics on sediment affected by varying concentrations of antibiotics adsorbable species. At the experimental pH values, the major adsorbed species of SMX and OFL on sediment were SMX 0 and OFL + by hydrophobic interaction and electrostatic attraction, respectively. The apparent adsorption rate of SMX was not affected by the initial concentration and the pH values because the hydrophobic interactions were concentration-independent and charge-independent. However, the apparent adsorption rate of OFL significantly slowed down as the initial concentration increased. The adsorbed OFL + effectively neutralized the negative charges of the sediment, leading to a reduced adsorption rate of subsequent OFL + . The neutralization effect was greatly enhanced due to the increased OFL + with the increasing OFL concentration. Additionally, the apparent adsorption rate of OFL significantly increased at higher pH due to the reduced neutralization effect that resulted from the decreased OFL + and increased negative charges of the sediment surface. This study implied that the adsorption kinetics of antibiotics was greatly dominated by the concentration of adsorbable species rather than apparent overall concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of soil properties on critical concentrations of cadmium, lead, copper, zinc, and mercury in soil and soil solution in view of ecotoxicological effects.

PubMed

de Vries, Wim; Lofts, Steve; Tipping, Ed; Meili, Markus; Groenenberg, Jan E; Schütze, Gudrun

2007-01-01

Risk assessment for metals in terrestrial ecosystems, including assessments of critical loads, requires appropriate critical limits for metal concentrations in soil and soil solution. This chapter presents an overview of methodologies used to derive critical (i) reactive and total metal concentrations in soils and (ii) free metal ion and total metal concentrations in soil solution for Cd, Pb, Cu, Zn, and Hg, taking into account the effect of soil properties related to ecotoxicological effects. Most emphasis is given to the derivation of critical free and total metal concentrations in soil solution, using available NOEC soil data and transfer functions relating solid-phase and dissolved metal concentrations. This approach is based on the assumption that impacts on test organisms (plants, microorganisms, and soil invertebrates) are mainly related to the soil solution concentration (activity) and not to the soil solid-phase content. Critical Cd, Pb, Cu, Zn, and Hg concentrations in soil solution vary with pH and DOC level. The results obtained are generally comparable to those derived for surface waters based on impacts to aquatic organisms. Critical soil metal concentrations, related to the derived soil solution limits, can be described as a function of pH and organic matter and clay content, and varying about one order of magnitude between different soil types.

Acute and 3-month effects of microcrystalline hydroxyapatite, calcium citrate and calcium carbonate on serum calcium and markers of bone turnover: a randomised controlled trial in postmenopausal women.

PubMed

Bristow, Sarah M; Gamble, Greg D; Stewart, Angela; Horne, Lauren; House, Meaghan E; Aati, Opetaia; Mihov, Borislav; Horne, Anne M; Reid, Ian R

2014-11-28

Ca supplements are used for bone health; however, they have been associated with increased cardiovascular risk, which may relate to their acute effects on serum Ca concentrations. Microcrystalline hydroxyapatite (MCH) could affect serum Ca concentrations less than conventional Ca supplements, but its effects on bone turnover are unclear. In the present study, we compared the acute and 3-month effects of MCH with conventional Ca supplements on concentrations of serum Ca, phosphate, parathyroid hormone and bone turnover markers. We randomised 100 women (mean age 71 years) to 1 g/d of Ca as citrate or carbonate (citrate-carbonate), one of two MCH preparations, or a placebo. Blood was sampled for 8 h after the first dose, and after 3 months of daily supplementation. To determine whether the acute effects changed over time, eight participants assigned to the citrate dose repeated 8 h of blood sampling at 3 months. There were no differences between the citrate and carbonate groups, or between the two MCH groups, so their results were pooled. The citrate-carbonate dose increased ionised and total Ca concentrations for up to 8 h, and this was not diminished after 3 months. MCH increased ionised Ca concentrations less than the citrate-carbonate dose; however, it raised the concentrations of phosphate and the Ca-phosphate product. The citrate-carbonate and MCH doses produced comparable decreases in bone resorption (measured as serum C-telopeptide (CTX)) over 8 h and bone turnover (CTX and procollagen type-I N-terminal propeptide) at 3 months. These findings suggest that Ca preparations, in general, produce repeated sustained increases in serum Ca concentrations after ingestion of each dose and that Ca supplements with smaller effects on serum Ca concentrations may have equivalent efficacy in suppressing bone turnover.

Acute and chronic toxicity of nickel to rainbow trout (Oncorhynchus mykiss).

PubMed

Brix, Kevin V; Keithly, James; DeForest, David K; Laughlin, Jim

2004-09-01

Of the fish species tested in chronic Ni exposures, rainbow trout (Oncorhynchus mykiss) is the most sensitive. To develop additional Ni toxicity data and to investigate the toxic mode of action for Ni, we conducted acute (96-h) and chronic (85-d early life-stage) flow-through studies using rainbow trout. In addition to standard toxicological endpoints, we investigated the effects of Ni on ionoregulatory physiology (Na, Ca, and Mg). The acute median lethal concentration for Ni was 20.8 mg/L, and the 24-h gill median lethal accumulation was 666 nmol/g wet weight. No effects on plasma Ca, Mg, or Na were observed during acute exposure. In the chronic study, no significant effects on embryo survival, swim-up, hatching, or fingerling survival or growth were observed at dissolved Ni concentrations up to 466 microg/L, the highest concentration tested. This concentration is considerably higher than the only other reported chronic no-observed-effect concentration (<33 microg/L) for rainbow trout. Accumulation of Ni in trout eggs indicates the chorion is only a partial barrier with 36%, 63%, and 1% of total accumulated Ni associated with the chorion, yolk, and embryo, respectively. Whole-egg ion concentrations were reduced by Ni exposure. However, most of this reduction occurred in the chorion rather than in the embryos, and no effects on hatching success or larval survival were observed as a result. Plasma ion concentrations measured in swim-up fingerlings at the end of the chronic-exposure period were not significantly reduced by exposure to Ni. Nickel accumulated on the gill in an exponential manner but plateaued in trout plasma at waterborne Ni concentrations of 118 microg/L or greater. Consistent with previous studies, Ni did not appear to disrupt ionoregulation in acute exposures of rainbow trout. Our results also suggest that Ni is not an ionoregulatory toxicant in long-term exposures, but the lack of effects in the highest Ni treatment precludes a definitive conclusion.

Assessment of neurotoxic effects of mercury in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) from the Canadian Arctic.

PubMed

Krey, Anke; Ostertag, Sonja K; Chan, Hing Man

2015-03-15

Marine mammals are indicator species of the Arctic ecosystem and an integral component of the traditional Inuit diet. The potential neurotoxic effects of increased mercury (Hg) in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) are not clear. We assessed the risk of Hg-associated neurotoxicity to these species by comparing their brain Hg concentrations with threshold concentrations for toxic endpoints detected in laboratory animals and field observations: clinical symptoms (>6.75 mg/kg wet weight (ww)), neuropathological signs (>4 mg/kg ww), neurochemical changes (>0.4 mg/kg ww), and neurobehavioral changes (>0.1mg/kg ww). The total Hg (THg) concentrations in the cerebellum and frontal lobe of ringed seals and polar bears were <0.5mg/kg ww, whereas the average concentration in beluga whale brain was >3mg/kg ww. Our results suggest that brain THg levels in polar bears are below levels that induce neurobehavioral effects as reported in the literature, while THg concentrations in ringed seals are within the range that elicit neurobehavioral effects and individual ringed seals exceed the threshold for neurochemical changes. The relatively high THg concentration in beluga whales exceeds all of the neurotoxicity thresholds assessed. High brain selenium (Se):Hg molar ratios were observed in all three species, suggesting that Se could protect the animals from Hg-associated neurotoxicity. This assessment was limited by several factors that influence neurotoxic effects in animals, including: animal species; form of Hg in the brain; and interactions with modifiers of Hg-associated toxicity, such as Se. Comparing brain Hg concentrations in wildlife with concentrations of appropriate laboratory studies can be used as a tool for risk characterization of the neurotoxic effects of Hg in Arctic marine mammals. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of vitamin D and calcium supplementation on side effects profile in patients of breast cancer treated with letrozole.

PubMed

Arul Vijaya Vani, S; Ananthanarayanan, P H; Kadambari, D; Harichandrakumar, K T; Niranjjan, R; Nandeesha, H

2016-08-01

Vitamin D deficiency (<10ng/mL) and insufficiency (10-30ng/mL) may contribute to musculoskeletal symptoms observed in patients taking letrozole. This study was undertaken to assess the vitamin D status in breast cancer patients who received letrozole for >2months and to see the effects of vitamin D3 and calcium supplementation on them. Eighty-two breast cancer patients were included. Baseline serum 25-hydroxy vitamin D concentrations were assayed and standard questionnaire was completed. They were given vitamin D3 and calcium supplementation (2000IU/1000 mg and 4000IU/1000mg) based on their baseline serum 25-hydroxy vitamin D concentration for 12weeks. Baseline serum 25-hydroxy vitamin D concentrations showed that 13.4% of patients were deficient and 73.2% of patients were insufficient in 25-hydroxy vitamin D. There was an increase in the concentrations of calcium, phosphorus and decrease in the concentrations of parathyroid hormone, alkaline phosphatase as the concentration of serum 25-hydroxy vitamin D increases. Patients who received letrozole for a longer duration had a low concentration of serum 25 (OH) vitamin D. Vitamin D3 and calcium supplementation increased the concentrations of calcium, phosphorous and decreased the concentrations of parathyroid hormone and alkaline phosphatase. Patients who had low serum 25-hydroxy vitamin D concentrations had more musculoskeletal symptoms which was improved following supplementation (9.14 vs 8.10 p=0.000). Vitamin D3 supplementation significantly improved serum 25-hydroxy vitamin D concentrations and decreased letrozole-induced arthralgia. Copyright © 2016 Elsevier B.V. All rights reserved.

Dose-response behavior of the bacterium Vibrio fischeri exposed to pharmaceuticals and personal care products.

PubMed

Ortiz de García, Sheyla; García-Encina, Pedro A; Irusta-Mata, Rubén

2016-01-01

The presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a real and widespread concern in recent years. Therefore, the primary goal of this study was to investigate 20 common and widely used PPCPs to assess their individual and combined effect on an important species in one trophic level, i.e., bacteria. The ecotoxicological effects of PPCPs at two different concentration ranges were determined in the bacterium Vibrio fischeri using Microtox(®) and were statistically analyzed using three models in the GraphPad Prism 6 program for Windows, v.6.03. A four-parameter model best fit the majority of the compounds. The half maximal effective concentration (EC50) of each PPCP was estimated using the best-fitting model and was compared with the results from a recent study. Comparative analysis indicated that most compounds showed the same level of toxicity. Moreover, the stimulatory effects of PPCPs at environmental concentrations (low doses) were assessed. These results indicated that certain compounds have traditional inverted U- or J-shaped dose-response curves, and 55% of them presented a stimulatory effect below the zero effect-concentration point. Effective concentrations of 0 (EC0), 5 (EC5) and 50% (EC50) were calculated for each PPCP as the ecotoxicological points. All compounds that presented narcosis as a mode of toxic action at high doses also exhibited stimulation at low concentrations. The maximum stimulatory effect of a mixture was higher than the highest stimulatory effect of each individually tested compound. Moreover, when the exposure time was increased, the hormetic effect decreased. Hormesis is being increasingly included in dose-response studies because this may have a harmful, beneficial or indifferent effect in an environment. Despite the results obtained in this research, further investigations need to be conducted to elucidate the behavior of PPCPs in aquatic environments.

Effects of terbutryn on aufwuchs and Lumbriculus variegatus in artificial indoor streams.

PubMed

Brust, K; Licht, O; Hultsch, V; Jungmann, D; Nagel, R

2001-09-01

The effects of the herbicide terbutryn on a simple lotic food web were investigated during a 72-d exposure period in five artificial indoor streams in a greenhouse. The model compound terbutryn, an s-triazine and an inhibitor of photosynthesis, was applied once in each stream at nominal concentrations of 0.6, 6, 60, or 600 microg/L. Terbutryn concentrations in the water were analyzed by gas chromatography/mass spectrometry, and an overall time to 50% dissipation (DT50) of 28 d was calculated. The development of aufwuchs and the population growth and development of the oligochaete Lumbriculus variegatus were investigated. We determined that terbutryn was toxic to L. variegatus at 23.7 mg/L (96-h median lethal concentration [LC50]) and 16.5 mg/L (96-h median effective concentration [EC50]) in static acute toxicity tests. Terbutryn decreased aufwuchs production at 0.6 microg/L in the experimental streams. Population growth of L. variegatus was decreased by 50% at 6 microg/L. The effect of terbutryn on the aufwuchs was a direct effect of decreases in the periphyton. However, the effects on L. variegatus were an indirect effect of terbutryn as a consequence of decrease in the aufwuchs food source and occurred at three-orders-of-magnitude-lower concentrations of terbutryn than the acute toxicity effects. Our study demonstrates the utility of indoor lotic microcosm studies for evaluating both direct and indirect effects of contaminants on aquatic ecosystems.

Evaluation of synergistic anticandidal and apoptotic effects of ferulic acid and caspofungin against Candida albicans.

PubMed

Canturk, Zerrin

2018-01-01

This study aimed to investigate the synergy between anticandidal and apoptotic effects of ferulic acid and caspofungin against Candida albicans and Candida glabrata, with the help of a quantitative checkerboard microdilution assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) as a viability dye. Apoptotic effects of caspofungin and ferulic acid concentrations (alone and combined) were analyzed for C. albicans and C. glabrata based on annexin V-propidium iodide binding capacities using flow cytometric analysis. C. albicans showed a synergistic effect, represented by a fractional inhibitory concentration index of < 0.5, but C. glabrata showed no synergistic effect (fractional inhibitory concentration index > 0.5). Early and late apoptotic effects of caspofungin and ferulic acid concentrations (1 μg/mL and 1000 μg/mL) were calculated as 55.7% and 18.3%, respectively, while their necrotic effects were determined as 5.8% and 51.6%, respectively, using flow cytometric analyses. The apoptotic effects of the combination of caspofungin and ferulic acid at concentrations of 1 μg/mL and 1000 μg/mL on C. albicans and C. glabrata were 73.0% and 48.7%, respectively. Ferulic acid also demonstrated a synergistic effect in combination with caspofungin against C. albicans. Another possibility is to combine the existing anticandidal drug with phytochemicals to enhance the efficacy of anticandidal drug. Copyright © 2017. Published by Elsevier B.V.

Prothrombin complex concentrates and a specific antidote to dabigatran are effective ex-vivo in reversing the effects of dabigatran in an anticoagulation/liver trauma experimental model.

PubMed

Grottke, Oliver; van Ryn, Joanne; Spronk, Henri M H; Rossaint, Rolf

2014-02-05

New oral anticoagulants are effective alternatives to warfarin. However, no specific reversal agents are available for life-threatening bleeding or emergency surgery. Using a porcine model of trauma, this study assessed the ability of prothrombin complex concentrate (PCC), activated PCC (aPCC), recombinant FVIIa (rFVIIa) and a specific antidote to dabigatran (aDabi-Fab) to reverse the anticoagulant effects of dabigatran. Dabigatran etexilate (DE) was given orally for 3 days (30 mg/kg bid) and intravenously on day 4 to achieve consistent, supratherapeutic concentrations of dabigatran. Blood samples were collected at baseline, after oral DE, after intravenous dabigatran, and 60 minutes post-injury. PCC (30 and 60 U/kg), aPCC (30 and 60 U/kg), rFVIIa (90 and 180 μg/kg) and antidote (60 and 120 mg/kg) were added to blood samples ex-vivo. Coagulation was assessed by thromboelastometry, global coagulation assays and diluted thrombin time. Plasma concentrations of dabigatran were 380 ± 106 ng/ml and 1423 ± 432 ng/ml after oral and intravenous administration, respectively, and all coagulation parameters were affected by dabigatran. Both PCCs and aDabi-Fab, but not rFVIIa, reversed the effects of dabigatran on thromboelastometry parameters and prothrombin time. In contrast, aPTT was only normalised by aDabi-Fab. Plasma concentration (activity) of dabigatran remained elevated after PCC and rFVIIa therapy, but was not measureable after aDabi-Fab. In conclusion, PCC and aPCC were effective in reducing the anticoagulant effects of dabigatran under different conditions, while aDabi-Fab fully corrected all coagulation measures and decreased the plasma concentration of dabigatran below the limit of detection. No significant effects were observed with rFVIIa.

In Silico Modeling of Crabtree Effect.

PubMed

Ghosh, Debraj; De, Rajat K

2017-01-01

Glycolytic activity during Crabtree effect is similar to that in tumor cells. Research regarding Crabtree effect is very much crucial. The mechanism of metabolic activities in glycolysis pathway and oxidative phosphorylation pathway in regards to Crabtree effect in Saccharomyces cerevisiae was studied in this paper. We also explored the effects of hexose phosphates in the activities of respiratory chain complexes (III and IV) in inhibition of respiration. Besides, the enhancement of fermentation in response to excess glucose concentration was studied. We discussed the significance of Crabtree effect in mammalian cancer in terms of Crabtree effect in a Crabtree positive organism, as it is similar to cancer metabolism in mammalian cells. We developed an in silico model of Crabtree effect. A comparative study was performed with laboratory experiments regarding inhibitory role of fructose 1,6-bisphosphate on metabolic respiration. The model was simulated for different concentration levels of glucose and hexose phosphates using COPASI and SNOOPY tools. We have shown that a hike in glucose concentration increases ethanol concentration and leads glycolytic activity towards fermentation. This phenomenon occurs during Crabtree effect. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Construction of an array of LEDs coupled to a concentrator for phototherapy

NASA Astrophysics Data System (ADS)

Almeida, Joana; Liang, Dawei

2011-07-01

The use of LED devices for phototherapy has been expanding in the last decade. This technology provides a safer emission spectrum in large target tissue areas when compared to laser emissions. For enhancing the phototherapeutic effects of red light emitted by LEDs, a simple optical concentrator capable of efficient light concentration and homogenization was developed. The LEDs wavelength of 660 nm is coincident with an absorption peak of the mitochondrial photoreceptor molecule cytochrome c oxidase. The prototype was optimized by non-sequential ray-tracing software ZEMAX, attaining both excellent light uniformity and 50mW/cm2 irradiance at the concentrator output end. Heat emanated from the LEDs source is effectively dissipated by the side walls of the concentrator, ensuring a nearly constant temperature environment for tissue treatment. The prototype was tested on cutaneous hyperpigmented marks caused by cupping in two healthy volunteers. Marks were irradiated by LEDs radiations with or without the use of concentrator respectively. Equal exposure durations and light fluences were tested. The use of the concentrator-coupled LEDs source revealed an activation of blood movement immediately after LEDs exposure, an effect not attainable by the LEDs source without the concentrator even at extended exposure time. Promising futures for the treatment of inflammation, tissue repair and skin rejuvenation could be expected by adopting this simple technique.

Antioxidant-rich spice added to hamburger meat during cooking results in reduced meat, plasma, and urine malondialdehyde concentrations1234

PubMed Central

Li, Zhaoping; Henning, Susanne M; Zhang, Yanjun; Zerlin, Alona; Li, Luyi; Gao, Kun; Lee, Ru-Po; Karp, Hannah; Thames, Gail; Bowerman, Susan

2010-01-01

Background: Emerging science has shown the effect of oxidation products and inflammation on atherogenesis and carcinogenesis. Cooking hamburger meat can promote the formation of malondialdehyde that can be absorbed after ingestion. Objective:We studied the effect of an antioxidant spice mixture on malondialdehyde formation while cooking hamburger meat and its effects on plasma and urinary malondialdehyde concentrations. Design: Eleven healthy volunteers consumed 2 kinds of burgers in a randomized order: one burger was seasoned with a spice blend, and one burger was not seasoned with the spice blend. The production of malondialdehyde in burgers and malondialdehyde concentrations in plasma and urine after ingestion were measured by HPLC. Results:Rosmarinic acid from oregano was monitored to assess the effect of cooking on spice antioxidant content. Forty percent (19 mg) of the added rosmarinic acid remained in the spiced burger (SB) after cooking. There was a 71% reduction in the malondialdehyde concentration (mean ± SD: 0.52 ± 0.02 μmol/250 g) in the meat of the SBs compared with the malondialdehyde concentration (1.79 ± 0.17 μmol/250 g) in the meat of the control burgers (CBs). The plasma malondialdehyde concentration increased significantly in the CB group as a change from baseline (P = 0.026). There was a significant time-trend difference (P = 0.013) between the 2 groups. Urinary malondialdehyde concentrations (μmol/g creatinine) decreased by 49% (P = 0.021) in subjects consuming the SBs compared with subjects consuming the CBs. Conclusions: The overall effect of adding the spice mixture to hamburger meat before cooking was a reduction in malondialdehyde concentrations in the meat, plasma, and urine after ingestion. Therefore, cooking hamburgers with a polyphenol-rich spice mixture can significantly decrease the concentration of malondialdehyde, which suggests potential health benefits for atherogenesis and carcinogenesis. This trial was registered at clinical trials.gov as NCT01027052. PMID:20335545

Low concentrations of doxycycline attenuates FasL-induced apoptosis in HeLa cells.

PubMed

Yoon, Jung Mi; Koppula, Sushruta; Huh, Se Jong; Hur, Sun Jin; Kim, Chan Gil

2015-07-24

Doxycycline (DC) has been shown to possess non-antibiotic properties including Fas/Fas Ligand (FasL)-mediated apoptosis against several tumor types in the concentration range of 10-40 µg/mL. However, the effect of DC in apoptotic signaling at much low concentrations was not studied. The present study investigated the attenuation effect of low dose of DC on FasL-induced apoptosis in HeLa cell by the methods of MTT assay, fluorescence microscopy, DNA fragmentation, flow cytometry analysis, and western blotting. In the present findings we showed that low concentration of DC (<2.0 µg/mL) exhibited protective effects against FasL-induced apoptosis in HeLa cells. FasL treatment to HeLa cells resulted in a concentration-dependent induction of cell death, and treatment with low concentrations of DC (0.1-2 µg/mL) significantly (p < 0.001) attenuated the FasL-induced cell death as measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Further, the FasL-induced apoptotic features in HeLa cells, such as morphological changes, DNA fragmentation and cell cycle arrest was also inhibited by DC (0.5 µg/mL). Tetracycline and minocycline also showed similar anti-apoptotic effects but were not significant when compared to DC, tested at same concentrations. Further, DC (0.01-16 µg/mL) did not influence the hydrogen peroxide- or cisplatin-induced intrinsic apoptotic pathway in HeLa cells. Protein analysis using Western blotting confirmed that FasL-induced cleavage/activation of caspase-8 and caspase-3, were inhibited by DC treatment at low concentration (0.5 µg/mL). Considering the overall data, we report for the first time that DC exhibited anti-apoptotic effects at low concentrations in HeLa cells by inhibition of caspase activation via FasL-induced extrinsic pathway.

Effect of hypothyroidism on insulin sensitivity and glucose tolerance in dogs.

PubMed

Hofer-Inteeworn, Natalie; Panciera, David L; Monroe, William E; Saker, Korinn E; Davies, Rebecca Hegstad; Refsal, Kent R; Kemnitz, Joseph W

2012-04-01

To determine the effects of hypothyroidism on insulin sensitivity, glucose tolerance, and concentrations of hormones counter-regulatory to insulin in dogs. 8 anestrous mixed-breed bitches with experimentally induced hypothyroidism and 8 euthyroid control dogs. The insulin-modified frequently sampled IV glucose tolerance test and minimal model analysis were used to determine basal plasma insulin and glucose concentrations, acute insulin response to glucose, insulin sensitivity, glucose effectiveness, and disposition index. Growth hormone response was assessed by stimulation and suppression tests. Additionally, basal serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentrations and urine cortisol-to-creatinine concentration ratios were measured and dual energy x-ray absorptiometry was performed to evaluate body composition. Insulin sensitivity was lower in the hypothyroid group than in the euthyroid group, whereas acute insulin response to glucose was higher. Glucose effectiveness and disposition index were not different between groups. Basal serum GH and IGF-1 concentrations as well as abdominal fat content were high in hypothyroid dogs, but urine cortisol-to-creatinine concentration ratios were unchanged. Hypothyroidism appeared to negatively affect glucose homeostasis by inducing insulin resistance, but overall glucose tolerance was maintained by increased insulin secretion in hypothyroid dogs. Possible factors affecting insulin sensitivity are high serum GH and IGF-1 concentrations and an increase in abdominal fat. In dogs with diseases involving impaired insulin secretion such as diabetes mellitus, concurrent hypothyroidism can have important clinical implications.

Effects of pH and sugar concentration in Zygosaccharomyces rouxii growth and time for spoilage in concentrated grape juice at isothermal and non-isothermal conditions.

PubMed

Rojo, M C; Arroyo López, F N; Lerena, M C; Mercado, L; Torres, A; Combina, M

2014-04-01

The effect of pH (1.7-3.2) and sugar concentration (64-68 °Brix) on the growth of Zygosaccharomyces rouxii MC9 using response surface methodology was studied. Experiments were carried out in concentrated grape juice inoculated with Z. rouxii at isothermal conditions (23 °C) for 60 days. pH was the variable with the highest effect on growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar concentration were also significant. In a second experiment, the time for spoilage by this microorganism in concentrated grape juice was evaluated at isothermal (23 °C) and non-isothermal conditions, in an effort to reproduce standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest impact on delaying the spoilage of the product. Thereby, a pH value below 2.0 was enough to increase the shelf life of the product for more than 60 days in both isothermal and non-isothermal conditions. The information obtained in the present work could be used by producers and buyers to predict the growth and time for spoilage of Z. rouxii in concentrated grape juice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of biofilm formation by D-tyrosine: Effect of bacterial type and D-tyrosine concentration.

PubMed

Yu, Cong; Li, Xuening; Zhang, Nan; Wen, Donghui; Liu, Charles; Li, Qilin

2016-04-01

D-Tyrosine inhibits formation and triggers disassembly of bacterial biofilm and has been proposed for biofouling control applications. This study probes the impact of D-tyrosine in different biofilm formation stages in both G+ and G- bacteria, and reveals a non-monotonic correlation between D-tyrosine concentration and biofilm inhibition effect. In the attachment stage, cell adhesion was studied in a flow chamber, where D-tyrosine caused significant reduction in cell attachment. Biofilms formed by Pseudomonas aeruginosa and Bacillus subtilis were characterized by confocal laser scanning microscopy as well as quantitative analysis of cellular biomass and extracellular polymeric substances. D-Tyrosine exhibited strong inhibitive effects on both biofilms with an effective concentration as low as 5 nM; the biofilms responded to D-tyrosine concentration change in a non-monotonic, bi-modal pattern. In addition, D-tyrosine showed notable and different impact on EPS production by G+ and G- bacteria. Extracellular protein was decreased in P. aeruginosa biofilms, but increased in those of B. subtilis. Exopolysaccharides production by P. aeruginosa was increased at low concentrations and reduced at high concentrations while no impact was found in B. subtilis. These results suggest that distinct mechanisms are at play at different D-tyrosine concentrations and they may be species specific. Dosage of D-tyrosine must be carefully controlled for biofouling control applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential concentration-specific effects of caffeine on cell viability, oxidative stress, and cell cycle in pulmonary oxygen toxicity in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiwari, Kirti Kumar; Chu, Chun; Couroucli, Xanthi

Highlights: • Caffeine at 0.05 mM decreases oxidative stress in hyperoxia. • Caffeine at 1 mM decreases cell viability, increases oxidative stress in hyperoxia. • Caffeine at 1 but not 0.05 mM, abrogates hyperoxia-induced G2/M arrest. - Abstract: Caffeine is used to prevent bronchopulmonary dysplasia (BPD) in premature neonates. Hyperoxia contributes to the development of BPD, inhibits cell proliferation and decreases cell survival. The mechanisms responsible for the protective effect of caffeine in pulmonary oxygen toxicity remain largely unknown. A549 and MLE 12 pulmonary epithelial cells were exposed to hyperoxia or maintained in room air, in the presence of differentmore » concentrations (0, 0.05, 0.1 and 1 mM) of caffeine. Caffeine had a differential concentration-specific effect on cell cycle progression, oxidative stress and viability, with 1 mM concentration being deleterious and 0.05 mM being protective. Reactive oxygen species (ROS) generation during hyperoxia was modulated by caffeine in a similar concentration-specific manner. Caffeine at 1 mM, but not at the 0.05 mM concentration decreased the G2 arrest in these cells. Taken together this study shows the novel funding that caffeine has a concentration-specific effect on cell cycle regulation, ROS generation, and cell survival in hyperoxic conditions.« less

Toxicity of triphenyltin and tributyltin to the freshwater mudsnail Potamopyrgus antipodarum in a new sediment biotest.

PubMed

Duft, Martina; Schulte-Oehlmann, Ulrike; Tillmann, Michaela; Markert, Bernd; Oehlmann, Jörg

2003-01-01

The effects of two suspected endocrine-disrupting chemicals, the xeno-androgens triphenyltin (TPT) and tributyltin (TBT), were investigated in a new whole-sediment biotest with the freshwater mudsnail Potamopyrgus antipodarum (Gastropoda, Prosobranchia). Artificial sediments were spiked with seven concentrations, ranging from 10 to 500 microg nominal TPT-Sn/kg dry weight and TBT-Sn/kg dry weight, respectively. We analyzed the responses of the test species after two, four, and eight weeks exposure. For both compounds, P. antipodarum exhibited a sharp decline in the number of embryos sheltered in its brood pouch in a time- and concentration-dependent manner in comparison to the control sediment. The number of new, still unshelled embryos turned out to be the most sensitive parameter. The lowest-observed-effect concentration (LOEC) was equivalent to the lowest administered concentration (10 microg/kg of each test compound) for most parameters and thus no no-observed-effect concentration (NOEC) could be established. The calculation of effect concentrations (EC10) resulted in even lower values for both substances (EC10 after eight weeks for unshelled embryos: 0.03 microg TPT-Sn/kg, EC10 after four weeks for unshelled embryos: 0.98 microg TBT-Sn/kg). Our results indicate that P. antipodarum is highly sensitive to both endocrine disruptors TPT and TBT at environmentally relevant concentrations.

Texture of low-fat Iranian White cheese as influenced by gum tragacanth as a fat replacer.

PubMed

Rahimi, J; Khosrowshahi, A; Madadlou, A; Aziznia, S

2007-09-01

The effect of different concentrations of gum tragacanth on the textural characteristics of low-fat Iranian White cheese was studied during ripening. A batch of full-fat and 5 batches of low-fat Iranian White cheeses with different gum tragacanth concentrations (without gum or with 0.25, 0.5, 0.75, or 1 g of gum/kg of milk) were produced to study the effects of fat content reduction and gum concentration on the textural and functional properties of the product during ripening. Cheese samples were analyzed with respect to chemical, color, and sensory characteristics, rheological parameters (uniaxial compression and small-amplitude oscillatory shear), and microstructure. Reducing the fat content had an adverse effect on cheese yield, sensory characteristics, and the texture of Iranian White cheese, and it increased the instrumental hardness parameters (i.e., fracture stress, elastic modulus, storage modulus, and complex modulus). However, increasing the gum tragacanth concentration reduced the values of instrumental hardness parameters and increased the whiteness of cheese. Although when the gum concentration was increased, the low-fat cheese somewhat resembled its full-fat counterpart, the interaction of the gum concentration with ripening time caused visible undesirable effects on cheese characteristics by the sixth week of ripening. Cheeses with a high gum tragacanth concentration became very soft and their solid texture declined somewhat.

Concentration of clarithromycin and 14-R-hydroxy-clarithromycin in plasma of patients with Mycobacterium avium complex infection, before and after the addition of rifampicin.

PubMed

Yamamoto, F; Harada, S; Mitsuyama, T; Harada, Y; Kitahara, Y; Yoshida, M; Nakanishi, Y

2004-02-01

Clarithromycin (CAM) and rifampicin (RFP) have both been recognized to be effective antibiotic agents against Mycobacterium avium complex (MAC) infection. Rifamycin derivatives including RFP and rifabutin modulate the CAM metabolism by inducing the hepatic cytochrome p-450 3A4. To clarify the effect of RFP on the CAM metabolism, we measured the plasma concentration of CAM and 14-R-hydroxyclarithromycin (M-5), the major metabolite of CAM, in 9 patients suffering from MAC infection before and after the addition of RFP. After the addition of RFP, the mean plasma concentration of CAM significantly decreased, while that of M-5 did not. In addition, the amount of CAM + M-5 concentration also significantly decreased. As M-5 is less effective against MAC infection than CAM, more attention should thus be paid to the plasma CAM concentration in patients administered CAM and RFP concomitantly.

Parameters and kinetics of olive mill wastewater dephenolization by immobilized Rhodotorula glutinis cells.

PubMed

Bozkoyunlu, Gaye; Takaç, Serpil

2014-01-01

Olive mill wastewater (OMW) with total phenol (TP) concentration range of 300-1200 mg/L was treated with alginate-immobilized Rhodotorula glutinis cells in batch system. The effects of pellet properties (diameter, alginate concentration and cell loading (CL)) and operational parameters (initial TP concentration, agitation rate and reusability of pellets) on dephenolization of OMW were studied. Up to 87% dephenolization was obtained after 120 h biodegradations. The utilization number of pellets increased with the addition of calcium ions into the biodegradation medium. The overall effectiveness factors calculated for different conditions showed that diffusional limitations arising from pellet size and pellet composition could be neglected. Mass transfer limitations appeared to be more effective at high substrate concentrations and low agitation rates. The parameters of logistic model for growth kinetics of R. glutinis in OMW were estimated at different initial phenol concentrations of OMW by curve-fitting of experimental data with the model.

[The effect of docosahexaenoic acid on the loss of appetite in pediatric patients with pneumonia].

PubMed

López-Alarcón, Mardya; Furuya-Meguro, María Magdalena; García-Zúñiga, Pedro Alberto; Tadeo-Pulido, Irsa

2006-01-01

To evaluate the role of docosahexaenoic acid (DHA) administered during the acute phase of pneumonia in infants, on appetite, cytokines and leptin concentrations. Seventeen children between three months and 12 years of age were followed from hospitalization to discharge. Children were randomly assigned to receive DHA or placebo. The effect of treatment was evaluated on energy intake, cytokines, and leptin concentrations. Cytokine concentrations tended to decrease earlier in DHA children. By day 4, concentrations of IL-1beta and TNFalpha had decreased by 12%, while such concentrations increased by 12% and 250% in placebo children. Energy intake recovered in DHA children at discharge, but placebo children were still consuming only 60% of their requirements. Our results suggest that DHA administered in the acute phase of infection could modulate IL-1 and TNF production, and secondarily, decrease the effect of infection on appetite.

[Study on teratogenic effect of potassium dichromate on Vicia faba root tip cells].

PubMed

Qian, Xiao-Wei

2004-05-01

We studied the aberrant effects of different concentrations of potassium dichromate on Vicia faba root tip cells. The micronucleus and chromosome aberration assay was conducted to determine the micronucleus rate and chromosome aberration rate of Vicia faba root tip cells induced by potassium dichromate. The result indicated that potassium dichromate could increase the micronucleus rate of Vicia faba root tip cells. Within certain range of concentration the rate of micronucleus was found to be increased with the increase of potassium dichromate concentration,but beyond this range the rate of micronucleus decreased with further increase of potassium dichromate concentration. The potassium dichromate at different concentrations could increase the cell mitosis index. Besides,it also caused various types of chromosome aberration,and the rates of chromosome aberration were always higher than that of the control group. The conclusion of this study was that potassium dichromate has obvious teratogenic effect on Vicia faba root tip cells.

Concentration of organic contaminants in fish and their biological effects in a wastewater-dominated urban stream

USGS Publications Warehouse

Lozano, Nuria; Rice, Clifford P.; Pagano, James; Zintek, Larry; Barber, Larry B.; Murphy, Elizabeth W.; Nettesheim, Todd G.; Minarik, Thomas A.; Schoenfuss, Heiko L.

2012-01-01

Data are presented on the concentrations of alkylphenol and alkylphenol ethoxylates (APEs) and persistent organic compounds in largemouth bass collected from a waste-water dominated stream in downtown Chicago. The fish residue concentrations of APEs are compared to concentrations of the APEs in the water that were collected at weekly intervals over two months bracketing the fall (2006) and a spring (2007) fish collection. The concentrations of APEs were significantly higher in the spring-collected fish (5.42 μg/g) versus the fall (0.99 μg/g) tand these differences were shared by differences in the water concentrations (spring — 11.47 versus fall — 3.44 μg/L). The differences in water concentration were negatively correlated with water temperatures observed over the two sampling times. Fish residue concentrations of persistent organic compounds (PCBs, PBDEs, toxaphene, and many legacy pesticides including the DDT family) did not vary from fall to spring. Some of these residue concentrations were comparable to the highest NPE (nonylphenol ethoxylate) homologue concentrations, e.g. NP1EO was 3.5 μg/g in the bass for the spring, the PBDE-congener 47 and p,p′-DDE averaged 1.0 μg/g and 0.5 μg/g, respectively, over both seasons. All the other persistent single-analyte concentrations were lower. Biological endpoints for endocrine effects measured in the same fish showed that there was an apparent positive correlation for physiological effects based on increased vitellogenin levels in males versus concentration of NPEs; however there were no observable histological differences in fall versus spring fish samples.

Changes in relative and absolute concentrations of plasma phospholipid fatty acids observed in a randomized trial of Omega-3 fatty acids supplementation in Uganda

PubMed Central

Song, Xiaoling; Diep, Pho; Schenk, Jeannette M; Casper, Corey; Orem, Jackson; Makhoul, Zeina; Lampe, Johanna W; Neuhouser, Marian L.

2016-01-01

Expressing circulating phospholipid fatty acids (PLFAs) in relative concentrations has some limitations: the total of all fatty acids are summed to 100%; therefore, the values of individual fatty acid are not independent. In this study we examined if both relative and absolute metrics could effectively measure changes in circulating PLFA concentrations in an intervention trial. 66 HIV and HHV8 infected patients in Uganda were randomized to take 3g/d of either long-chain omega-3 fatty acids (1,856 mg EPA and 1,232 mg DHA) or high—oleic safflower oil in a 12-week double-blind trial. Plasma samples were collected at baseline and end of trial. Relative weight percentage and absolute concentrations of 41 plasma PLFAs were measured using gas chromatography. Total cholesterol was also measured. Intervention-effect changes in concentrations were calculated as differences between end of 12-week trial and baseline. Pearson correlations of relative and absolute concentration changes in individual PLFAs were high (>0.6) for 37 of the 41 PLFAs analyzed. In the intervention arm, 17 PLFAs changed significantly in relative concentration and 16 in absolute concentration, 15 of which were identical. Absolute concentration of total PLFAs decreased 95.1 mg/L (95% CI: 26.0, 164.2; P = 0.0085), but total cholesterol did not change significantly in the intervention arm. No significant change was observed in any of the measurements in the placebo arm. Both relative weight percentage and absolute concentrations could effectively measure changes in plasma PLFA concentrations. EPA and DHA supplementation changes the concentrations of multiple plasma PLFAs besides EPA and DHA. PMID:27926458

Solvent Extraction of Rare Earth Elements from a Nitric Acid Leach Solution of Apatite by Mixtures of Tributyl Phosphate and Di-(2-ethylhexyl) Phosphoric Acid

NASA Astrophysics Data System (ADS)

Ferdowsi, Ali; Yoozbashizadeh, Hossein

2017-12-01

Solvent extraction of rare earths from nitrate leach liquor of apatite using mixtures of tributyl phosphate (TBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was studied. The effects of nitrate and hydrogen ion concentration of the aqueous phase as well as the composition and concentration of extractants in the organic phase on the extraction behavior of lanthanum, cerium, neodymium, and yttrium were investigated. The distribution ratio of REEs increases by increasing the nitrate concentration in aqueous phase and concentration of extractants in organic phase, but the hydrogen ion concentration in aqueous phase has a decreasing effect. Yttrium as a heavy rare earth is more sensitive to these parameters than light rare earth elements. Although the composition of organic phase has a minor effect on the extraction of light rare earths, the percent of extraction of yttrium decreases dramatically by increasing the TBP content of organic phase. Mixtures of TBP and D2EHPA can show either synergism or antagonism extraction depending on the concentration and composition of extractants in organic phase. The best condition for separating rare earth elements in groups of heavy and light REEs can be achieved at high nitrate concentration, low H+ concentration, and high concentration of D2EHPA in organic phase. Separation of Ce and La by TBP and D2EHPA is practically impossible in the studied conditions; however, low nitrate concentration and high hydrogen ion concentration in aqueous phase and low concentration of extractants in organic phase favor the separation of Nd from other light rare earth elements.

Effect of vitamin supplementation on breast milk concentrations of retinol, carotenoids, and tocopherols in HIV-infected Tanzanian women

PubMed Central

Webb, Aimee L.; Aboud, Said; Furtado, Jeremy; Murrin, Clare; Campos, Hannia; Fawzi, Wafaie W.; Villamor, Eduardo

2011-01-01

Background The effect of daily prenatal and postnatal vitamin supplementation on concentrations of breast milk nutrients is not well characterized in HIV-infected women. Objective We examined the impact of vitamin supplementation during pregnancy and lactation on breast milk concentrations of retinol, carotenoids, and tocopherols during the first year post-partum among 626 HIV-infected Tanzanian women. Design We conducted a randomized, double-blind, placebo controlled trial. Women were assigned to one of four daily oral supplements: vitamin A + β-carotene (VA+BC); multivitamins (B, C, E (MV)); MV+VA+BC; or placebo. Concentrations of breast milk nutrients were determined by HPLC at birth and every 3 mo thereafter. Results Supplementation with VA+BC increased concentrations of retinol, β-carotene, and α-carotene at delivery by 4799, 1791, and 84 nmol/L, respectively, compared to no VA+BC (all p<0.0001). MV supplementation did not increase concentrations of α-tocopherol or δ-tocopherol at delivery but significantly decreased concentrations of breast milk γ-tocopherol and retinol. Although concentrations of all nutrients decreased significantly by 3 months postpartum, retinol, α-carotene, and β-carotene concentrations were significantly higher among those receiving VA+BC at 3, 6, and 12 mo compared to no VA+BC. Alpha tocopherol was significantly higher, while γ-tocopherol concentrations were significantly lower, among women receiving MV compared to no MV at 3, 6, and 12 mo post-partum. Conclusions Sustained supplementation of HIV-infected breastfeeding mothers with MV could be a safe and effective intervention to improve vitamin E concentrations in breast milk. VA+BC supplementation increases concentrations of breast milk retinol but it is not recommended in HIV-infected mothers due to the elevated risk of vertical transmission. PMID:17940544

Effect of vitamin supplementation on breast milk concentrations of retinol, carotenoids and tocopherols in HIV-infected Tanzanian women.

PubMed

Webb, A L; Aboud, S; Furtado, J; Murrin, C; Campos, H; Fawzi, W W; Villamor, E

2009-03-01

The effect of daily prenatal and postnatal vitamin supplementation on concentrations of breast milk nutrients is not well characterized in HIV-infected women. We examined the impact of vitamin supplementation during pregnancy and lactation on breast milk concentrations of retinol, carotenoids and tocopherols during the first year postpartum among 626 HIV-infected Tanzanian women. We conducted a randomized, double-blind, placebo-controlled trial. Women were assigned to one of four daily oral supplements: vitamin A+beta-carotene (VA+BC); multivitamins (MV; B, C and E); MV+VA+BC or placebo. Concentrations of breast milk nutrients were determined by high-performance liquid chromatography at birth and every 3 months thereafter. Supplementation with VA+BC increased concentrations of retinol, beta-carotene and alpha-carotene at delivery by 4799, 1791 and 84 nmol l(-1), respectively, compared to no VA+BC (all P<0.0001). MV supplementation did not increase concentrations of alpha-tocopherol or delta-tocopherol at delivery but significantly decreased concentrations of breast milk gamma-tocopherol and retinol. Although concentrations of all nutrients decreased significantly by 3 months postpartum, retinol, alpha-carotene and beta-carotene concentrations were significantly higher among those receiving VA+BC at 3, 6 and 12 months compared to no VA+BC. alpha-Tocopherol was significantly higher, while gamma-tocopherol concentrations were significantly lower, among women receiving MV compared to no MV at 3, 6 and 12 months postpartum. Sustained supplementation of HIV-infected breastfeeding mothers with MV could be a safe and effective intervention to improve vitamin E concentrations in breast milk. VA+BC supplementation increases concentrations of breast milk retinol but it is not recommended in HIV-infected mothers due to the elevated risk of vertical transmission.

Ultrasonic degradation of acetaminophen in water: effect of sonochemical parameters and water matrix.

PubMed

Villaroel, Erica; Silva-Agredo, Javier; Petrier, Christian; Taborda, Gonzalo; Torres-Palma, Ricardo A

2014-09-01

This paper deals about the sonochemical water treatment of acetaminophen (ACP, N-acetyl-p-aminophenol or paracetamol), one of the most popular pharmaceutical compounds found in natural and drinking waters. Effect of ultrasonic power (20-60 W), initial ACP concentration (33-1323 μmol L(-1)) and pH (3-12) were evaluated. High ultrasonic powers and, low and natural acidic pH values favored the efficiency of the treatment. Effect of initial substrate concentration showed that the Langmuir-type kinetic model fit well the ACP sonochemical degradation. The influence of organic compounds in the water matrix, at concentrations 10-fold higher than ACP, was also evaluated. The results indicated that only organic compounds having a higher value of the Henry's law constant than the substrate decrease the efficiency of the treatment. On the other hand, ACP degradation in mineral natural water showed to be strongly dependent of the initial substrate concentration. A positive matrix effect was observed at low ACP concentrations (1.65 μmol L(-1)), which was attributed to the presence of bicarbonate ion in solution. However, at relative high ACP concentrations a detrimental effect of matrix components was noticed. Finally, the results indicated that ultrasonic action is able to transform ACP in aliphatic organic compounds that could be subsequently eliminated in a biological system. Copyright © 2014 Elsevier B.V. All rights reserved.

Clinical concentrations of chemically diverse general anesthetics minimally affect lipid bilayer properties.

PubMed

Herold, Karl F; Sanford, R Lea; Lee, William; Andersen, Olaf S; Hemmings, Hugh C

2017-03-21

General anesthetics have revolutionized medicine by facilitating invasive procedures, and have thus become essential drugs. However, detailed understanding of their molecular mechanisms remains elusive. A mechanism proposed over a century ago involving unspecified interactions with the lipid bilayer known as the unitary lipid-based hypothesis of anesthetic action, has been challenged by evidence for direct anesthetic interactions with a range of proteins, including transmembrane ion channels. Anesthetic concentrations in the membrane are high (10-100 mM), however, and there is no experimental evidence ruling out a role for the lipid bilayer in their ion channel effects. A recent hypothesis proposes that anesthetic-induced changes in ion channel function result from changes in bilayer lateral pressure that arise from partitioning of anesthetics into the bilayer. We examined the effects of a broad range of chemically diverse general anesthetics and related nonanesthetics on lipid bilayer properties using an established fluorescence assay that senses drug-induced changes in lipid bilayer properties. None of the compounds tested altered bilayer properties sufficiently to produce meaningful changes in ion channel function at clinically relevant concentrations. Even supra-anesthetic concentrations caused minimal bilayer effects, although much higher (toxic) concentrations of certain anesthetic agents did alter lipid bilayer properties. We conclude that general anesthetics have minimal effects on bilayer properties at clinically relevant concentrations, indicating that anesthetic effects on ion channel function are not bilayer-mediated but rather involve direct protein interactions.

Labour analgesia with intrathecal fentanyl decreases maternal stress.

PubMed

Cascio, M; Pygon, B; Bernett, C; Ramanathan, S

1997-06-01

Lumbar epidural analgesia (LEA) decreases maternal stress as measured by maternal circulating plasma catecholamine concentrations. Intrathecal fentanyl (ITF) provides effective labour analgesia but its effect on maternal epinephrine (Epi) and norepinephrine (NE) concentrations is not known. This study assesses whether ITF reduces maternal stress in the same manner as conventional LEA. Twenty-four healthy women in active labour received either 25 micrograms ITF (n = 12) or epidural lidocaine 1.5% (n = 12) for analgesia. Venous blood samples were collected before anaesthesia and at five minute intervals for 30 min following anaesthesia for the measurement of plasma Epi and NE by high performance liquid chromatography. Maternal blood pressure (BP), heart rate (HR), visual analog scores (VAS) to pain and pruritus were recorded at the same time. Both ITF and LEA decreased pain VAS scores, maternal BP, and plasma Epi concentrations with only minimal effects on plasma NE concentrations. Intrathecal fentanyl (ITF) and LEA reduced plasma epi to a similar extent, with ITF reducing the levels slightly faster than LEA. Intrathecal fentanyl(ITF) and LEA reduced plasma Epi concentrations by 52% and 51%, respectively (P value < 0.01). We conclude that ITF is as effective as LEA in producing pain relief in the labouring patient. Intrathecal Fentanyl (ITF) is also capable of reducing maternal plasma epinephrine concentration, thus avoiding the possibly deleterious side effects of excess amounts of this catecholamine during labour.

Effect of Lead stress on phosphatase activity and reducing power assay of Triticum aestivum.

PubMed

Gubrelay, U; Agnihotri, R K; Shrotriya, S; Sharma, R

2015-06-24

Lead (Pb) is a highly toxic heavy metal for both plants and animals; the environment is increasingly polluted with heavy metals and reduces crop productivity. Plants possess homeostatic mechanisms that allow them to keep correct concentrations of essential metal ions in cellular compartments and to minimize the damaging effects of an excess of nonessential ones. One of their adverse effects on plants are the generation of harmful active oxygen species, leading to oxidative stress and the antioxidative activity seems to be of fundamental importance for adaptive response of plant against environmental stress. The present study explores the effects of lead (soil treated twice/ week) with (10, 30 and 60 mM) on the specific activities of phosphatases which might lead to reducing power assay in (Triticum aestivum PBW344) seedling. A significant decrease in the redox potential of shoot compared to root was observed at the similar concentration of lead. A similar trend on leaves was also noted. Acid and alkaline phosphatase activities were significantly higher in roots than in shoot at all the three concentration of lead i.e. 10, 30 and 60 mM, compared to controls. The above mentioned changes were more pronounced at 60 mM concentration of lead than two other concentrations. These results lead us to suggest that increased lead concentration in soil might lead to adverse effects on plant growth and phosphatase activities.

Assessment of the effects of nickel on benthic macroinvertebrates in the field.

PubMed

Peters, Adam; Simpson, Peter; Merrington, Graham; Schlekat, Chris; Rogevich-Garman, Emily

2014-01-01

A field-based evaluation of the biological effects of potential nickel (Ni) exposures was conducted using monitoring data for benthic macroinvertebrates and water chemistry parameters for streams in England and Wales. Observed benthic community metrics were compared to expected community metrics under reference conditions using RIVPACS III+ software. In order to evaluate relationships between Ni concentrations and benthic community metrics, bioavailable Ni concentrations were also calculated for each site. A limiting effect from Ni on the 90th percentile of the maximum achievable ecological quality was derived at "bioavailable Ni" exposures of 10.3 μg l(-1). As snails have been identified as particularly sensitive to nickel exposure, snail abundance in the field in response to nickel exposure, relative to reference conditions, was also analysed. A "low effects" threshold for snail abundance based on an average of spring and autumn data was derived as 3.9 μg l(-1) bioavailable Ni. There was no apparent effect of Ni exposure on the abundance of Ephemeroptera (mayflies), Plecoptera (stoneflies) or Tricoptera (caddisflies) when expressed relative to a reference condition within the range of "bioavailable Ni" exposures observed within the dataset. Nickel exposure concentrations co-vary with the concentrations of other stressors in the dataset, and high concentrations of Ni are also associated with elevated concentrations of other contaminants.

EFFECT OF ACUTE STRESS ON PLASMA B-CORTICOSTERONE, ESTRADIOL-17B AND TESTOSTERONE CONCENTRATIONS IN JUVENILE AMERICAN ALLIGATORS COLLECTED FROM THREE SITES WITHIN THE KISSIMMEE-EVERGLADES DRAINAGE BASIN IN FLORIDA (USA)

EPA Science Inventory

The effect of acute stress on plasma b-corticosterone (B), testosterone (T) and estradiol-17b (E2), concentrations in juvenile alligators collected from sites with varying sediment contaminants was examined in this study. Dramatic increases in plasma B concentrations were observe...

Effects of pore-scale dispersion, degree of heterogeneity, sampling size, and source volume on the concentration moments of conservative solutes in heterogeneous formations

Treesearch

Daniele Tonina; Alberto Bellin

2008-01-01

Pore-scale dispersion (PSD), aquifer heterogeneity, sampling volume, and source size influence solute concentrations of conservative tracers transported in heterogeneous porous formations. In this work, we developed a new set of analytical solutions for the concentration ensemble mean, variance, and coefficient of variation (CV), which consider the effects of all these...

AICE Survey of USSR Air Pollution Literature, Volume 15: A Third Compilation of Technical Reports on the Biological Effects and the Public Health Aspects of Atmospheric Pollutants.

ERIC Educational Resources Information Center

Nuttonson, M. Y.

Ten papers were translated: Maximum permissible concentrations of noxious substances in the atmospheric air of populated areas; Some aspects of the biological effect of microconcentrations of two chloroisocyanates; The toxicology of low concentrations of aromatic hydrocarbons; Chronic action of low concentrations of acrolein in air on the…

Influence of birth order, birth weight, colostrum and serum immunoglobulin G on neonatal piglet survival.

PubMed

Cabrera, Rafael A; Lin, Xi; Campbell, Joy M; Moeser, Adam J; Odle, Jack

2012-12-23

Intake of colostrum after birth is essential to stimulate intestinal growth and function, and to provide systemic immunological protection via absorption of Immunoglobulin G (IgG). The birth order and weight of 745 piglets (from 75 litters) were recorded during a one-week period of farrowing. Only pigs weighing greater than 0.68 kg birth weight were chosen for the trial. Sow colostrum was collected during parturition, and piglets were bled between 48 and 72 hours post-birth. Piglet serum IgG and colostral IgG concentrations were determined by radial immunodiffusion. Sow parity had a significant (P < 0.001) effect on sow colostral IgG concentration, being 5% higher in multiparous females. Sow colostral IgG concentration explained 6% and piglet birth order accounted for another 4% of the variation observed in piglet serum IgG concentration (P < 0.05); however, birth weight had no detectable effect. Piglet serum IgG concentration had both a linear (P < 0.05) and quadratic effect (P < 0.05) on % survival. Piglets with 1,000 mg/dl serum IgG or less (n=24) had a 67% survival; whereas, piglets with IgG concentrations between 2250 to 2500 mg/dl (n=247) had a 91% survival. Birth order had no detectable effect on survival, but birth weight had a positive linear effect (P < 0.05). Piglets weighing 0.9 kg (n = 107) at birth had a 68% survival rate, and those weighing 1.6 kg (n = 158) had an 89% survival. We found that the combination of sow colostrum IgG concentration and birth order can account for 10% of the variation of piglet serum IgG concentration and that piglets with less than 1,000 mg/dl IgG serum concentration and weight of 0.9 kg at birth had low survival rate when compared to their larger siblings. The effective management of colostrum uptake in neonatal piglets in the first 24 hrs post-birth may potentially improve survival from birth to weaning.

Effects of concentrated and dephytinized wheat bran and rice bran addition on bread properties.

PubMed

Özkaya, Berrin; Baumgartner, Burcu; Özkaya, Hazım

2018-02-01

Wheat bran and rice bran were concentrated in terms of dietary fiber and were dephytinized by two different methods (fermentation and hydrothermal). Untreated, concentrated, concentrated-dephytinized by fermentation method, and concentrated-dephytinized by hydrothermal method bran samples were each incorporated into flour at levels of 0, 10, 15, and 20%, and their effects on bread properties were investigated. Unprocessed wheat bran and rice bran addition decreased the volume yield, and the specific volume of the bread depends on the incorporation level. A further decrease was observed with the addition of concentrated bran. However, the dephytinization treatments slightly improved these values. The same pattern was observed for the total number of cells and the total cell area of bread crumbs. Both wheat bran and rice bran were observed to cause a darker crumb color, and the effects of bran samples on crumb color were more pronounced after the dephytinization treatment. The addition of concentrated wheat bran and rice bran significantly increased hardness, as well as decreasing springiness, cohesiveness, and resilience of the bread, depending on the bran levels. Although dephytinization treatments enhanced the textural properties of bread, these results were still inferior to those obtained using bread produced with untreated bran. Regarding the dephytinization treatments, the influence of fermentation treatment on bread properties was slightly beneficial compared to hydrothermal treatment. Consumption of dietary fiber offers a range of health benefits. Cereal bran has great potential as a dietary fiber source. However, this bran's high phytic acid content and adverse effects on bread quality limit that potential. It is possible to obtain high dietary fiber and low phytic acid bran samples through bran concentration and dephytinization treatments. The dephytinization treatment is an effective method for degradation of phytic acid. The negative effects of wheat bran and rice bran on bread quality decreased significantly following the dephytinization treatments. This study demonstrated that fiber-enriched bread with low phytic acid content and acceptable texture can be produced using concentrated and dephytinized bran. © 2017 Wiley Periodicals, Inc.

Heavy metals in bullfrog (Rana catesbeiana) tadpoles: Effects of depuration before analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, J.; Snodgrass, J.

1998-11-01

Although tadpoles may well be excellent organisms to use as bioindicators of heavy metal contamination, the relationship of deposition in the body compared to the tail, and the effect of sediments or other debris in the digestive tract on heavy metal concentrations is unknown. The authors examined the effect of experimental depuration of bullfrog (Rana catesbeiana) tadpoles on heavy metal and selenium concentrations in intact tadpoles, as well as their bodies and tails. They defined depuration in this experiment as allowing defecation as an elimination process for intestinal contents. The authors maintained wild-caught tadpoles in clean water for 0, 24,more » 48, and 72 h to determine the effects of clearing on heavy metal concentrations. They also examined the concentrations of heavy metals in the whole body and digestive tract separately. The authors test the null hypotheses that no differences occur in metals as a function of time in uncontaminated water, and that no differences occur in metal concentrations in the body compared to the tail and to the digestive tract. They rejected these hypotheses based on regression models. Variance in concentrations of chromium (77%) and lead (70%) were explained by part and clearing time; for manganese (80%), mercury (64%), selenium (28%), and cadmium (25%) the variation was explained only by body part; for arsenic (53%), the variation was explained by part, clearing time, and weight of the various parts. For those metals in which clearing time explained part of the variation, metal concentrations in both the body and tail decreased after 24 and 48 h, but increased slightly thereafter. Clearing, however, did not greatly decrease metal concentrations in either the body or tail. These data suggest that for some metals (mercury, manganese, cadmium, selenium), clearing has no effect, and for others the effect is slight. For fresh tadpoles, however, the digestive tract contained significantly higher concentrations of all metals than either the body or head, probably reflecting metals absorbed to sediment particles in the gut.« less

Mechanistic explanation of time-dependent cross-phenomenon based on quorum sensing: A case study of the mixture of sulfonamide and quorum sensing inhibitor to bioluminescence of Aliivibrio fischeri.

PubMed

Sun, Haoyu; Pan, Yongzheng; Gu, Yue; Lin, Zhifen

2018-07-15

Cross-phenomenon in which the concentration-response curve (CRC) for a mixture crosses the CRC for the reference model has been identified in many studies, expressed as a heterogeneous pattern of joint toxic action. However, a mechanistic explanation of the cross-phenomenon has thus far been extremely insufficient. In this study, a time-dependent cross-phenomenon was observed, in which the cross-concentration range between the CRC for the mixture of sulfamethoxypyridazine (SMP) and (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone (C30) to the bioluminescence of Aliivibrio fischeri (A. fischeri) and the CRC for independent action model with 95% confidence bands varied from low-concentration to higher-concentration regions in a timely manner expressed the joint toxic action of the mixture changing with an increase of both concentration and time. Through investigating the time-dependent hormetic effects of SMP and C30 (by measuring the expression of protein mRNA, simulating the bioluminescent reaction and analyzing the toxic action), the underlying mechanism was as follows: SMP and C30 acted on the quorum sensing (QS) system of A. fischeri, which induced low-concentration stimulatory effects and high-concentration inhibitory effects; in the low-concentration region, the stimulatory effects of SMP and C30 made the mixture produce a synergistic stimulation on the bioluminescence; thus, the joint toxic action exhibited antagonism. In the high-concentration region, the inhibitory effects of SMP and C30 in the mixture caused a double block in the loop circuit of the QS system; thus, the joint toxic action exhibited synergism. With the increase of time, these stimulatory and inhibitory effects of SMP and C30 were changed by the variation of the QS system at different growth phases, resulting in the time-dependent cross-phenomenon. This study proposes an induced mechanism for time-dependent cross-phenomenon based on QS, which may provide new insight into the mechanistic investigation of time-dependent cross-phenomenon, benefitting the environmental risk assessment of mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of birth order, birth weight, colostrum and serum immunoglobulin G on neonatal piglet survival

PubMed Central

2012-01-01

Background Intake of colostrum after birth is essential to stimulate intestinal growth and function, and to provide systemic immunological protection via absorption of Immunoglobulin G (IgG). The birth order and weight of 745 piglets (from 75 litters) were recorded during a one-week period of farrowing. Only pigs weighing greater than 0.68 kg birth weight were chosen for the trial. Sow colostrum was collected during parturition, and piglets were bled between 48 and 72 hours post-birth. Piglet serum IgG and colostral IgG concentrations were determined by radial immunodiffusion. Results Sow parity had a significant (P < 0.001) effect on sow colostral IgG concentration, being 5% higher in multiparous females. Sow colostral IgG concentration explained 6% and piglet birth order accounted for another 4% of the variation observed in piglet serum IgG concentration (P < 0.05); however, birth weight had no detectable effect. Piglet serum IgG concentration had both a linear (P < 0.05) and quadratic effect (P < 0.05) on % survival. Piglets with 1,000 mg/dl serum IgG or less (n=24) had a 67% survival; whereas, piglets with IgG concentrations between 2250 to 2500 mg/dl (n=247) had a 91% survival. Birth order had no detectable effect on survival, but birth weight had a positive linear effect (P < 0.05). Piglets weighing 0.9 kg (n = 107) at birth had a 68% survival rate, and those weighing 1.6 kg (n = 158) had an 89% survival. Conclusion We found that the combination of sow colostrum IgG concentration and birth order can account for 10% of the variation of piglet serum IgG concentration and that piglets with less than 1,000 mg/dl IgG serum concentration and weight of 0.9 kg at birth had low survival rate when compared to their larger siblings. The effective management of colostrum uptake in neonatal piglets in the first 24 hrs post-birth may potentially improve survival from birth to weaning. PMID:23259926

Persistent Organic Pollutants in Norwegian Men from 1979 to 2007: Intraindividual Changes, Age–Period–Cohort Effects, and Model Predictions

PubMed Central

Breivik, Knut; Fuskevåg, Ole-Martin; Nieboer, Evert; Odland, Jon Øyvind; Sandanger, Torkjel Manning

2013-01-01

Background: Longitudinal monitoring studies of persistent organic pollutants (POPs) in human populations are important to better understand changes with time and age, and for future predictions. Objectives: We sought to describe serum POP time trends on an individual level, investigate age–period–cohort effects, and compare predicted polychlorinated biphenyl (PCB) concentrations to measured values. Methods: Serum was sampled in 1979, 1986, 1994, 2001, and 2007 from a cohort of 53 men in Northern Norway and analyzed for 41 POPs. Time period, age, and birth cohort effects were assessed by graphical analyses and mixed-effect models. We derived the predicted concentrations of four PCBs for each sampling year using the CoZMoMAN model. Results: The median decreases in summed serum POP concentrations (lipid-adjusted) in 1986, 1994, 2001, and 2007 relative to 1979 were –22%, –52%, –54%, and –68%, respectively. We observed substantial declines in all POP groups with the exception of chlordanes. Time period (reflected by sampling year) was the strongest descriptor of changes in PCB-153 concentrations. Predicted PCB-153 concentrations were consistent with measured concentrations in the study population. Conclusions: Our results suggest substantial intraindividual declines in serum concentrations of legacy POPs from 1979 to 2007 in men from Northern Norway. These changes are consistent with reduced environmental exposure during these 30 years and highlight the relation between historic emissions and POP concentrations measured in humans. Observed data and interpretations are supported by estimates from the CoZMoMAN emission-based model. A longitudinal decrease in concentrations with age was evident for all birth cohorts. Overall, our findings support the relevance of age–period–cohort effects to human biomonitoring of environmental contaminants. Citation: Nøst TH, Breivik K, Fuskevåg OM, Nieboer E, Odland JØ, Sandanger TM. 2013. Persistent organic pollutants in Norwegian men from 1979 to 2007: intraindividual changes, age–period–cohort effects, and model predictions. Environ Health Perspect 121:1292–1298; http://dx.doi.org/10.1289/ehp.1206317 PMID:24007675

Subinhibitory concentrations of phloretin repress the virulence of Salmonella typhimurium and protect against Salmonella typhimurium infection.

PubMed

Shuai-Cheng, Wu; Ben-Dong, Fu; Xiu-Ling, Chu; Jian-Qing, Su; Yun-Xing, Fu; Zhen-Qiang, Cui; Dao-Xiu, Xu; Zong-Mei, Wu

2016-11-01

Phloretin, a natural component of many fruits, exhibits anti-virulence effects and provides a new alternative to counter bacterial infection. The aim of this study was to determine the effect of subinhibitory concentrations of phloretin on the virulence of Salmonella typhimurium. At concentrations where growth of Salmonella was not inhibited, phloretin significantly inhibited bacteria biofilm formation and motility. Subinhibitory concentrations of phloretin repressed eight genes involved in the Salmonella pathogenicity island 1 and 3 genes involved in flagella production. Furthermore, subinhibitory concentrations of phloretin inhibited the adhesion and invasion of Salmonella in IEC-6 cells and reduced the LDH levels of S. typhimurium-infected IEC-6 cells. Additionally, phloretin significantly decreased the cecum bacterial loads of the mice infected with live S. typhimurium containing subinhibitory concentrations of phloretin by gavage. These results suggested that subinhibitory concentrations of phloretin attenuate the virulence of S. typhimurium and protect against S. typhimurium infection.

Optimization of applied voltages for on-chip concentration of DNA using nanoslit

NASA Astrophysics Data System (ADS)

Azuma, Naoki; Itoh, Shintaro; Fukuzawa, Kenji; Zhang, Hedong

2017-12-01

On-chip sample concentration is an effective pretreatment to improve the detection sensitivity of lab-on-a-chip devices for biochemical analysis. In a previous study, we successfully achieved DNA sample concentration using a nanoslit fabricated in the microchannel of a device designed for DNA size separation. The nanoslit was a channel with a depth smaller than the diameter of a random coil-shaped DNA molecule. The concentration was achieved using the entropy trap at the boundary between the microchannel and the nanoslit. DNA molecules migrating toward the nanoslit owing to electrophoresis were trapped in front of the nanoslit and the concentration was enhanced over time. In this study, we successfully maximize the molecular concentration by optimizing the applied voltage for electrophoresis and verifying the effect of temperature. In addition, we propose a model formula that predicts the molecular concentration, the validity of which is confirmed through comparison with experimental results.

Data on Streamflow and Quality of Water and Bottom Sediment in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1998-2000

USGS Publications Warehouse

Paul, Angela P.; Thodal, Carl E.

2003-01-01

This study was initiated to expand upon previous findings that indicated concentrations of dissolved solids, arsenic, boron, mercury, molybdenum, selenium, and uranium were either above geochemical background concentrations or were approaching or exceeding ecological criteria in the lower Humboldt River system. Data were collected from May 1998 to September 2000 to further characterize streamflow and surface-water and bottom-sediment quality in the lower Humboldt River, selected agricultural drains, Upper Humboldt Lake, and Lower Humboldt Drain (ephemeral outflow from Humboldt Sink). During this study, flow in the lower Humboldt River was either at or above average. Flows in Army and Toulon Drains generally were higher than reported in previous investigations. An unnamed agricultural drain contributed a small amount to the flow measured in Army Drain. In general, measured concentrations of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium were higher in water from agricultural drains than in Humboldt River water during this study. Mercury concentrations in water samples collected during the study period typically were below the laboratory reporting level. However, low-level mercury analyses showed that samples collected in August 1999 from Army Drain had higher mercury concentrations than those collected from the river or Toulon Drain or the Lower Humboldt Drain. Ecological criteria and effect concentrations for sodium, chloride, dissolved solids, arsenic, boron, mercury, and molybdenum were exceeded in some water samples collected as part of this study. Although water samples from the agricultural drains typically contained higher concentrations of sodium, chloride, dissolved solids, arsenic, boron, and uranium, greater instantaneous loads of these constituents were carried in the river near Lovelock than in agricultural drains during periods of high flow or non-irrigation. During this study, the high flows in the lower Humboldt River produced the maximum instantaneous loads of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium at all river-sampling sites, except molybdenum near Imlay. Nevada Division of Environmental Protection monitoring reports on mine-dewatering discharge for permitted releases of treated effluent to the surface waters of the Humboldt River and its tributaries were reviewed for reported discharges and trace-element concentrations from June 1998 to September 1999. These data were compared with similar information for the river near Imlay. In all bottom sediments collected for this study, arsenic concentrations exceeded the Canadian Freshwater Interim Sediment-Quality Guideline for the protection of aquatic life and probable-effect level (concentration). Sediments collected near Imlay, Rye Patch Reservoir, Lovelock, and from Toulon Drain and Army Drain were found to contain cadmium and chromium concentrations that exceeded Canadian criteria. Chromium concentrations in sediments collected from these sites also exceeded the consensus-based threshold-effect concentration. The Canadian criterion for sediment copper concentration was exceeded in sediments collected from the Humboldt River near Lovelock and from Toulon, Army, and the unnamed agricultural drains. Mercury in sediments collected near Imlay and from Toulon Drain in August 1999 exceeded the U.S. Department of the Interior sediment probable-effect level. Nickel concentrations in sediments collected during this study were above the consensus-based threshold-effect concentration. All other river and drain sediments had constituent concentrations below protective criteria and toxicity thresholds. In Upper Humboldt Lake, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium concentrations in surface-water samples collected near the mouth of the Humboldt River generally were higher than in samples collected near the mouth of Army Drain. Ecological criteria or effect con

In vitro toxicity testing with microplate cell cultures: Impact of cell binding.

PubMed

Gülden, Michael; Schreiner, Jeannine; Seibert, Hasso

2015-06-05

In vitro generated data on toxic potencies are generally based on nominal concentrations. However, cellular and extracellular binding and elimination processes may reduce the available free fraction of a compound. Then, nominal effective concentrations do not represent appropriate measures of toxic exposure in vitro and underestimate toxic potencies. In this study it was investigated whether cell binding can affect the availability of chemicals in microplate based toxicity assays. To this end the cytotoxicity of compounds like mercury chloride, digitonin and alcohol ethoxylates, accumulated by cells via different modes, was investigated in 96-well microplate cultures with varying concentrations of Balb/c 3T3 cells. The median effective nominal concentrations of all but one of the tested compounds depended linearly from the cell concentration. Applying a previously developed equilibrium distribution model cell concentration-independent median effective extracellular concentrations and cell burdens, respectively, could be calculated. The compounds were accumulated by the cells with bioconcentration factors, BCF, between 480 and ≥ 25,000. Cell binding of the alcohol ethoxylates was correlated with their lipophilicity. The results show that significant cell binding can occur even at the small cell volume fractions (∼ 1 × 10(-5) to 3 × 10(-3) L/L) encountered in microplate assays. To what extent cell binding affects the bioavailability depends on the BCF and the cell volume fraction. EC50 measurements in the presence of at least two different cell concentrations allow for excluding or detecting significant cell binding and for determining more appropriate measures of toxic exposure in vitro like median effective extracellular (free) concentrations or cell burdens. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Plant sterols and stanols in the treatment of dyslipidemia: new insights into targets and mechanisms related to cardiovascular risk.

PubMed

Baumgartner, Sabine; Mensink, Ronald P; Plat, Jogchum

2011-01-01

Plant sterols and stanols are naturally occurring constituents of plants and as such normal components of our daily diet. The consumption of foods enriched in plant sterols and stanols may help to reduce low-density lipoprotein cholesterol (LDL-C) concentrations. Meta-analyses have shown that consuming approximately 2.5 g plant sterols or stanols per day lowers serum LDL-C concentrations up to 10%, with little additional benefit achieved at higher intakes. However, recent studies evaluating plant stanol intakes up to 9 g/d have indicated that LDL-C concentrations can be reduced up to 17%, which suggests that more pronounced reductions can be achieved at higher intakes. Studies describing effects of high plant sterol intakes on serum LDL-C concentrations are not consistent. Besides the effects of higher than advocated intakes on serum LDL-C concentrations, several topics will be discussed in this review. First, besides the well-characterized effect of plant sterols and stanols on serum LDL-C concentrations, evidence is now emerging of their effects on triacylglycerol metabolism, which makes them highly attractive for interventions in metabolic syndrome-like populations. Secondly, there is an ongoing debate whether increased plant sterol concentrations are associated with an increased cardiovascular disease risk or not. For this there are at least two possible explanations. First, the potential atherogenicity of increased plant sterol concentrations might be ascribed to the formation of plant sterol oxidation products (so-called oxyphytosterols) or secondly, elevated serum plant sterol concentrations should only be seen as surrogate markers for characterizing subjects with high intestinal cholesterol absorption. Finally, we discuss recent studies, which suggest that plant sterols and stanols can improve endothelial dysfunction in subjects at risk, although evidence is limited and more research is needed.

Fatty acid composition of muscle and adipose tissues of indigenous Caribbean goats under varying nutritional densities.

PubMed

Liméa, L; Alexandre, G; Berthelot, V

2012-02-01

The effects of a concentrate diet on growth, carcass fat, and fatty acid (FA) composition of muscle (supraspinatus), perirenal, and intermuscular adipose tissues of Creole goats (n = 32) were evaluated. Goats were fed a tropical green forage Digitaria decumbens ad libitum with no concentrate (G0) or 1 of 3 levels of concentrate: 140 (G100), 240 (G200), and 340 g•d(-1) (G300), respectively. Goats were slaughtered according to the standard procedure at the commercial BW (22 to 24 kg of BW). Goats fed the concentrate diets (G100, G200, and G300) had greater ADG (P < 0.001), cold carcass weights (P < 0.001), and omental (P < 0.01), perirenal (P < 0.01), and intermuscular (P < 0.01) adipose tissues weights. Dietary intake of C18:0, C18:1n-9, C18:2n-6 increased as concentrate supplementation increased (P < 0.001), whereas C18:3n-3 intake was not affected (P > 0.05). Increased concentrate supplementation did not affect (P > 0.05) the proportion of MUFA in all tissues and had very little effect on SFA in perirenal tissue, but increased the PUFA proportion in muscle (P < 0.05). The major effect of feeding increased concentrate was an increase in n-6 PUFA proportions in all tissues (P < 0.001) and, surprisingly, a decrease in n-3 PUFA (P < 0.001). Focusing on FA, which are supposed to have a beneficial or an adverse effect on human health, feeding increased concentrate did not increase the content of any cholesterol-increasing SFA in meat, but increased the n-6/n-3 ratio above 4 when more than 240 g of concentrate was fed per day.

Genetics-Based Population Pharmacokinetics and Pharmacodynamics of Risperidone in a Psychiatric Cohort.

PubMed

Vandenberghe, Frederik; Guidi, Monia; Choong, Eva; von Gunten, Armin; Conus, Philippe; Csajka, Chantal; Eap, Chin B

2015-12-01

High interindividual variability in plasma concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone, may lead to suboptimal drug concentration. Using a population pharmacokinetic approach, we aimed to characterize the genetic and non-genetic sources of variability affecting risperidone and 9-hydroxyrisperidone pharmacokinetics, and relate them to common side effects. Overall, 150 psychiatric patients (178 observations) treated with risperidone were genotyped for common polymorphisms in NR1/2, POR, PPARα, ABCB1, CYP2D6 and CYP3A genes. Plasma risperidone and 9-hydroxyrisperidone were measured, and clinical data and common clinical chemistry parameters were collected. Drug and metabolite concentrations were analyzed using non-linear mixed effect modeling (NONMEM(®)). Correlations between trough concentrations of the active moiety (risperidone plus 9-hydroxyrisperidone) and common side effects were assessed using logistic regression and linear mixed modeling. The cytochrome P450 (CYP) 2D6 phenotype explained 52% of interindividual variability in risperidone pharmacokinetics. The area under the concentration-time curve (AUC) of the active moiety was found to be 28% higher in CYP2D6 poor metabolizers compared with intermediate, extensive and ultrarapid metabolizers. No other genetic markers were found to significantly affect risperidone concentrations. 9-hydroxyrisperidone elimination was decreased by 26% with doubling of age. A correlation between trough predicted concentration of the active moiety and neurologic symptoms was found (p = 0.03), suggesting that a concentration >40 ng/mL should be targeted only in cases of insufficient, or absence of, response. Genetic polymorphisms of CYP2D6 play an important role in risperidone, 9-hydroxyrisperidone and active moiety plasma concentration variability, which were associated with common side effects. These results highlight the importance of a personalized dosage adjustment during risperidone treatment.

Entrainment, Drizzle, and the Indirect Effect in Stratiform Clouds

NASA Technical Reports Server (NTRS)

Ackerman, Andrew

2005-01-01

Activation of some fraction of increased concentrations of sub-micron soluble aerosol particles lead to enhanced cloud droplet concentrations and hence smaller droplets, increasing their total cross sectional area and thus reflecting solar radiation more efficiently (the Twomey, or first indirect, effect). However, because of competition during condensational growth, droplet distributions tend to broaden as numbers increase, reducing the sensitivity of cloud albedo to droplet concentration on the order of 10%. Also, smaller droplets less effectively produce drizzle through collisions and coalescence, and it is widely expected (and found in large-scale models) that decreased precipitation leads to clouds with more cloud water on average (the so-called cloud lifetime, or second indirect, effect). Much of the uncertainty regarding the overall indirect aerosol effect stems from inadequate understanding of such changes in cloud water. Detailed simulations based on FIRE-I, ASTEX, and DYCOMS-II conditions show that suppression of precipitation from increased droplet concentrations leads to increased cloud water only when sufficient precipitation reaches the surface, a condition favored when the overlying air is-humid or droplet concentrations are very low. Otherwise, aerosol induced suppression of precipitation enhances entrainment of overlying dry air, thereby reducing cloud water and diminishing the indirect climate forcing.

Antiproliferative effect of a polysaccharide fraction of a 20% methanolic extract of stinging nettle roots upon epithelial cells of the human prostate (LNCaP).

PubMed

Lichius, J J; Lenz, C; Lindemann, P; Müller, H H; Aumüller, G; Konrad, L

1999-10-01

In Germany, plant extracts are often used in the treatment of early stages of benign prostate hyperplasia (BPH). The effects of different concentrations of the polysaccharide fraction of the 20% methanolic extract of stinging nettle roots (POLY-M) on the cellular proliferation of lymph node carcinoma of the prostate (LNCaP) cells were determined by measurement of the genomic DNA content of the samples. All concentrations of POLY-M showed an inhibitory effect on the growth of the LNCaP cells during 7 days except the two lowest concentrations. The reduced proliferation of POLY-M treated LNCaP cells was significantly (p < 0.05) different from the untreated control. The inhibition was time- and concentration-dependent with the maximum suppression (50%) on day 6 and at concentrations of 1.0E-9 and 1.0E-11 mg/ml. No cytotoxic effect of POLY-M on cell proliferation was observed. The in vitro results show for the first time an antiproliferative effect of Urtica compounds on human prostatic epithelium and confirm our previous in vivo findings.

In vitro potential cytogenetic and oxidative stress effects of roxithromycin.

PubMed

Arslan, Mehmet; Timocin, Taygun; Ila, Hasan B

2017-10-01

Macrolide antibiotic roxithromycin was evaluated in terms of its genotoxic, cytotoxic and oxidative stress effects. For this purpose; 25, 50, 100 and 200 μg/mL concentrations of roxithromycin were dissolved in dimethyl sulfoxide and treated to human peripheral blood lymphocytes for two different treatment periods (24 and 48 h). In chromosome aberration (CA) and micronucleus (MN) tests, roxithromycin did not show genotoxic effect. But it induced sister chromatid exchange (SCE) at the highest concentration (200 μg/mL) for the 24-h treatment period and at all concentrations (except 25 μg/mL) for the 48-h treatment period. Looking at cytotoxic effect of roxithromycin, statistically insignificant decreases on mitotic index and proliferation index were observed. Roxithromycin decreased nuclear division index (NDI) at highest two concentrations (100 and 200 μg/mL) for the 24-h treatment period and at all concentrations (expect 25 μg/mL) for the 48-h treatment period. Total oxidant values, total antioxidant values and oxidative stress index did not change with roxithromycin treatment. Eventually, roxithromycin did not have genotoxic and oxidative stress effects in human-cultured lymphocytes.

Laccase-catalyzed removal of 2,4-dimethylphenol from synthetic wastewater: effect of polyethylene glycol and dissolved oxygen.

PubMed

Ghosh, J P; Taylor, K E; Bewtra, J K; Biswas, N

2008-04-01

The potential use of laccase (SP-504) in an advanced oxidation-based treatment technology to remove 2,4-dimethylphenol (DMP) from water was investigated with and without the additive, polyethylene glycol (PEG). The DMP concentration was varied between 1.0 and 5.0 mM. The optimization of pH and enzyme concentration in the presence and absence of PEG was carried out. All experiments were carried out in continuously stirred reactors for 3h at room temperature. The reaction was initiated by adding enzyme to the reaction mixture. For more than 95% removal of DMP, the presence of PEG reduced the inactivation of enzyme so that the required enzyme concentrations were reduced by about 2-fold compared to the same reactions in the absence of PEG. Finally, the PEG concentrations were optimized to obtain the minimum dose required. For higher substrate concentrations, the availability of oxygen was insufficient in achieving 95% or more removal. Therefore, the effect of increasing dissolved oxygen at higher substrate concentration was investigated. The laccase studied was capable of efficiently removing DMP at very low enzyme concentrations and hence shows great potential for cost-effective industrial applications.

Fluorescence spectroscopy of Rhodamine 6G: concentration and solvent effects.

PubMed

Zehentbauer, Florian M; Moretto, Claudia; Stephen, Ryan; Thevar, Thangavel; Gilchrist, John R; Pokrajac, Dubravka; Richard, Katherine L; Kiefer, Johannes

2014-01-01

Rhodamine 6G (R6G), also known as Rhodamine 590, is one of the most frequently used dyes for application in dye lasers and as a fluorescence tracer, e.g., in the area of environmental hydraulics. Knowing the spectroscopic characteristics of the optical emission is key to obtaining high conversion efficiency and measurement accuracy, respectively. In this work, solvent and concentration effects are studied. A series of eight different organic solvents (methanol, ethanol, n-propanol, iso-propanol, n-butanol, n-pentanol, acetone, and dimethyl sulfoxide (DMSO)) are investigated at constant dye concentration. Relatively small changes of the fluorescence spectrum are observed for the different solvents; the highest fluorescence intensity is observed for methanol and lowest for DMSO. The shortest peak wavelength is found in methanol (568 nm) and the longest in DMSO (579 nm). Concentration effects in aqueous R6G solutions are studied over the full concentration range from the solubility limit to highly dilute states. Changing the dye concentration provides tunability between ∼550 nm in the dilute case and ∼620 nm at high concentration, at which point the fluorescence spectrum indicates the formation of R6G aggregates. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of 15(S)-15-methyl prostaglandin F2 alpha methyl ester-containing silastic discs in male rats.

PubMed

Kimball, F A; Frielink, R D; Porteus, S E

1978-01-01

Silicone rubber discs containing 15(S)-15-methyl prostaglandin F2 alpha ester (15-Me-PGF2 alpha) in the matrix were implanted in the left side of the scrotums of Sprague-Dawley rats. The effect of 1% and 2% drug concentration was examined for 10, 20, or 28 days and compared with the effects of Silastic discs containing no prostaglandin. The discs containing prostaglandin reduced mean testicular and accessory gland weights. Histologically the testes and epididymides showed decreased or absent spermatogenic elements and hypertrophy of the interstitial cell masses in comparison with other cells. Implanted prostaglandin significantly depressed serum testosterone, luteinizing hormone, and follicle-stimulating hormone (FSH) concentrations when 15-Me-PGF2 alpha plasma concentrations exceeded 2 ng/ml. Hormone concentrations returned to control values as drug concentrations declined. FSH concentrations significantly exceeded control values 10 and 20 days after implantation, when prostaglandin concentration was nondetectable. The acute suppression of all three hormones suggest that 15-Me-PGF2 alpha either may act directly on the tests to suppress testosterone production or may suppress testosterone production or may suppress gonadotropin secretion, resulting in depressed testosterone output.

Effects of a low-radiotoxicity uranium salt (uranyl acetate) on biochemical and hematological parameters of the catfish, Clarias gariepinus

NASA Astrophysics Data System (ADS)

Al-Ghanim, Khalid A.; Ahmad, Zubair; Al-Kahem Al-Balawi, Hmoud F.; Al-Misned, Fahad; Maboob, Shahid; Suliman, El-Amin M.

2016-01-01

Specimens of Clarias gariepinus were treated with lethal (70, 75, 80, 85, 90, and 95 mg/L) and sub-lethal concentrations (8, 12 and 16 mg/L) of uranyl acetate, a low-radiotoxicity uranium salt. The LC 50 value was registered as 81.45 mg/L. The protein and glycogen concentrations in liver and muscles were decreased in the fish exposed to sub-lethal concentrations. The red blood cell (RBC) and white blood cell (WBC) counts, haemoglobin (Hb) concentration and haematocrit (Hct) values were decreased. Different blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were negatively affected. Level of plasma glucose was elevated whereas protein was decreased. The level of calcium concentration (Ca) was declined in the blood of exposed fish whereas magnesium (Mg) remains unchanged. The activity level of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) was elevated in exposed fish. These effects were more pronounced in the last period of exposure and in higher concentrations. Results of the present study indicate that uranyl acetate has adverse effects on Clarias gariepinus and causes changes in the biochemical and hematological parameters of the fish.

Effect of acetic acid in recycling water on ethanol production for cassava in an integrated ethanol-methane fermentation process.

PubMed

Yang, Xinchao; Wang, Ke; Zhang, Jianhua; Tang, Lei; Mao, Zhonggui

2016-11-01

Recently, the integrated ethanol-methane fermentation process has been studied to prevent wastewater pollution. However, when the anaerobic digestion reaction runs poorly, acetic acid will accumulate in the recycling water. In this paper, we studied the effect of low concentration of acetic acid (≤25 mM) on ethanol fermentation at different initial pH values (4.2, 5.2 or 6.2). At an initial pH of 4.2, ethanol yields increased by 3.0% and glycerol yields decreased by 33.6% as the acetic acid concentration was increased from 0 to 25 mM. Raising the concentration of acetic acid to 25 mM increased the buffering capacity of the medium without obvious effects on biomass production in the cassava medium. Acetic acid was metabolized by Saccharomyces cerevisiae for the reason that the final concentration of acetic acid was 38.17% lower than initial concentration at pH 5.2 when 25 mM acetic acid was added. These results confirmed that a low concentration of acetic acid in the process stimulated ethanol fermentation. Thus, reducing the acetic acid concentration to a controlled low level is more advantageous than completely removing it.

Effects of depleted uranium on the health and survival of Ceriodaphnia dubia and Hyalella azteca

USGS Publications Warehouse

Kuhne, W.W.; Caldwell, C.A.; Gould, W.R.; Fresquez, P.R.; Finger, S.

2002-01-01

Depleted uranium (DU) has been used as a substitute for the fissionable enriched uranium component of atomic weapons tested at Los Alamos National Laboratory (LANL) (Los Alamos, NM, USA) since the early 1950s, resulting in considerable concentrations of DU in the soils within the test sites. Although the movement of DU into major aquatic systems has been shown to be minimal, there are many small-order ephemeral streams and areas of standing water in canyons throughout LANL that may be affected by inputs of DU via runoff, erosion, and leaching. Ninety-six-hour acute and 7-d chronic toxicity assays were conducted to measure the toxicity of DU on survival and reproduction of Ceriodaphnia dubia. A 14-d water-only assay was conducted to measure survival and growth of Hyalella azteca. The estimated median lethal concentration (LC50) to produce 50% mortality of the test population for the 96-h Ceriodaphnia dubia assay was 10.50 mg/L. Reproductive effects occurred at a lowest-observable-effect concentration ???3.91 mg/L with a no-observable-effect concentration of 1.97 mg/L. The estimated 14-d LC50 for the Hyalella azteca assay was 1.52 mg/L No significant relationship was detected between growth and DU concentrations. Concentrations at which toxicity effects were observed in this study for both invertebrates exceeded concentrations of total uranium observed in runoff from LANL lands. Thus, it is likely that current runoff levels of uranium do not pose a threat to these types of aquatic invertebrates.

Impact of hydrocarbon type, concentration and weathering on its biodegradability in soil.

PubMed

Maletić, Snežana P; Dalmacija, Božo D; Rončević, Srđan D; Agbaba, Jasmina R; Perović, Svetlana D Ugarčina

2011-01-01

The objective of this research was to investigate the impact of the hydrocarbon type and concentration, as well as the total effect of the natural weathering process to hydrocarbon biodegradability in sandy soil and the environment. In this experiment, sandy soil was separately contaminated with 0.5%, 1.0%, 2.0% and 3.5% of diesel and crude oils. Oil contaminated soil was taken from the Oil Refinery dumping sites after 9 years of weathering, and its concentration was adjusted to the above-mentioned levels. The biodegradation process was monitored by measuring CO(2), evolution rate, hydrocarbon degradation rate and dehydrogenase activity. The favourable concentration ranges for the soil contaminated with diesel oil were 1.0%, with concentrations at about 2.0% causing slightly adverse effects to CO(2) production which was overcome after 2 weeks, and with 3.5% diesel oil causing significant toxicity. For soil contaminated with crude oil, 2.0% was found to be optimum for effective biodegradation, with 3.5% crude oil also causing adverse effects to CO(2) production, although less so than the same concentration of diesel oil. No adverse effect was obtained for any concentration of the weathered oil, as after the weathering process, the remaining contaminants in the soil were mostly poorly degradable constituents like asphaltenes, resins etc. It has been proposed that such residual material from oil degradation is analogous to, and can even be regarded as, humic material. Due to its inert characteristics, insolubility and similarity to humic materials it is unlikely to be environmentally hazardous.

D-malate production by permeabilized Pseudomonas pseudoalcaligenes; optimization of conversion and biocatalyst productivity.

PubMed

Michielsen, M J; Frielink, C; Wijffels, R H; Tramper, J; Beeftink, H H

2000-04-14

For the development of a continuous process for the production of solid D-malate from a Ca-maleate suspension by permeabilized Pseudomonas pseudoalcaligenes, it is important to understand the effect of appropriate process parameters on the stability and activity of the biocatalyst. Previously, we quantified the effect of product (D-malate2 -) concentration on both the first-order biocatalyst inactivation rate and on the biocatalytic conversion rate. The effects of the remaining process parameters (ionic strength, and substrate and Ca2 + concentration) on biocatalyst activity are reported here. At (common) ionic strengths below 2 M, biocatalyst activity was unaffected. At high substrate concentrations, inhibition occurred. Ca2+ concentration did not affect biocatalyst activity. The kinetic parameters (both for conversion and inactivation) were determined as a function of temperature by fitting the complete kinetic model, featuring substrate inhibition, competitive product inhibition and first-order irreversible biocatalyst inactivation, at different temperatures simultaneously through three extended data sets of substrate concentration versus time. Temperature affected both the conversion and inactivation parameters. The final model was used to calculate the substrate and biocatalyst costs per mmol of product in a continuous system with biocatalyst replenishment and biocatalyst recycling. Despite the effect of temperature on each kinetic parameter separately, the overall effect of temperature on the costs was found to be negligible (between 293 and 308 K). Within pertinent ranges, the sum of the substrate and biocatalyst costs per mmol of product was calculated to decrease with the influent substrate concentration and the residence time. The sum of the costs showed a minimum as a function of the influent biocatalyst concentration.

Effect of the Various Steps in the Processing of Human Milk in the Concentrations of IgA, IgM, and Lactoferrin.

PubMed

Arroyo, Gerardo; Ortiz Barrientos, Kevin Alexander; Lange, Karla; Nave, Federico; Miss Mas, Gabriela; Lam Aguilar, Pamela; Soto Galindo, Miguel Angel

2017-09-01

Human milk immune components are unique and important for the development of the newborn. Milk processing at the Human Milk Banks (HMB), however, causes partial destruction of immune proteins. The objective of this study was to determine the effects that heating during the milk processing procedure at the HMB had on the concentrations of IgA, IgM, and lactoferrin at three critical points in time. Fifty milk samples (150 mL) were collected from voluntary donors at the HMB at the Hospital Nacional Pedro de Bethancourt, located in Antigua Guatemala. Samples from three critical points in time during the milk processing procedure were selected for analysis: freezing/thawing I, freezing/thawing II, and pasteurization. IgA, IgM, and lactoferrin concentrations were determined during each critical point and compared with a baseline concentration. After milk processing, IgA, IgM, and lactoferrin mean concentrations were reduced by 30.0%, 36.0%, and 70.0%, respectively (p < 0.001). Reduction of biological activity was mainly attributed to pasteurization for IgA and lactoferrin (p < 0.001); the first freezing/thawing processes before pasteurization showed no significant reduction difference between mean concentrations of IgA (p = 0.160) and lactoferrin (p = 0.345) but showed a significant effect on IgM concentration (p = 0.016), and the second freezing/thawing procedure only showed a significant effect on IgA (p < 0.001). The effects of milk processing on the immune proteins that were evaluated in this study demonstrated a significant reduction.

Stabilizing two IgG1 monoclonal antibodies by surfactants: Balance between aggregation prevention and structure perturbation.

PubMed

Wang, Shujing; Wu, Guoliang; Zhang, Xinyi; Tian, Zhou; Zhang, Ning; Hu, Tao; Dai, Weiguo; Qian, Feng

2017-05-01

Surfactants are widely used as stabilizers in the biopharmaceutical formulations to minimize protein aggregation. Under a fixed stress condition, the protecting and destabilizing effects of surfactants are hypothesized to be highly dependent on the species and concentrations of surfactants and mAb. Therefore, we here studied the aggregation-prevention and structure-perturbation effects of eight commonly used surfactants (Tw20, Tw80, Brij35, Chaps, TrX-100, SDS, Pluronic F68 and F127) on two IgG1 solution formulations under agitation, using analytical methodologies including visual inspection, OD 350 measurement, HPLC-SEC, circular dicroism, fluorescence spectroscopy and differential scanning calorimetry. We found that: (1) With concentrations range from 0.02 to 2mg/mL, nonionic surfactants were found to offer efficient aggregation-prevention effect, which is superior than the ionic surfactants; and higher surfactant concentration prevented mAb aggregation better especially under prolonged stability test under stress conditions. (2) The surfactant induced structure-perturbation emerged when even higher surfactant concentration (≥2mg/mL) was used, and such effect was surfactant-property dependent; and (3) the two IgG1 demonstrated different aggregation mechanisms and surfactant dependency, especially at high mAb concentrations. In conclusion, surfactants usage in mAb formulations, including the types and concentrations, should strike an optimal balance between the desirable aggregation-prevention and the detrimental structure-perturbation effects, while the consideration of mAb aggregation mechanism and concentration is also required for surfactant assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

Parent and Metabolite Opioid Drug Concentrations in Unintentional Deaths Involving Opioid and Benzodiazepine Combinations*†‡

PubMed Central

Fields, Marcia D.; Abate, Marie A.; Hu, Lan; Long, D. Leann; Blommel, Matthew L.; Haikal, Nabila A.; Kraner, James C.

2016-01-01

Effects of benzodiazepines on postmortem opioid parent and parent/metabolite blood concentration ratios were determined for fentanyl-, hydrocodone-, methadone-, or oxycodone-related accidental deaths. These opioids are partially metabolized by the CYP3A4 enzyme system, which is also affected by diazepam and alprazolam. Opioid/metabolite combinations examined were as follows: fentanyl/norfentanyl, hydrocodone/dihydrocodeine, methadone/EDDP, and oxycodone/oxymorphone. Parent opioid concentrations were analyzed for 877 deaths. Parent/metabolite concentration ratios were analyzed for 349 deaths, excluding cases with co-intoxicants present known to interfere with opioid elimination. Alprazolam in combination with diazepam significantly decreased median hydrocodone concentrations by 48% (p = 0.01) compared to hydrocodone alone. The methadone parent/metabolite concentration ratio was reduced by 35% in the presence of diazepam compared to methadone alone (p = 0.03). Benzodiazepines did not statistically significantly affect fentanyl or oxycodone concentrations. Possible factors affecting opioid concentrations and possible toxicity development, including any differential effects on specific opioids, should continue to be explored. PMID:26223761

Stress concentration in the vicinity of a hole defect under conditions of Hertzian contact

NASA Technical Reports Server (NTRS)

Yamamoto, T.; Eguchi, M.; Murayama, K.

1981-01-01

Two dimensional photoelastic stress analyses were conducted for epoxy resin models containing a hole defect under the conditions of Hertzian contact. Stress concentrations around the defect were determined as a function of several parameters. The effect of tangential traction on the stress concentration was also determined. Sharp stress concentrations occur in the vicinity of both the left and the right side of the hole. The stress concentration becomes more distinct the larger the hole diameter and the smaller distance between the hole and the contact surface. The stress concentration is greatest when the disk imposing a normal load is located at the contact surface directly over the hole. The magnitude and the location of stress concentration varies with the distance between the Hertzian contact area and the hole. The area involved in a process of rolling contact fatigue is confined to a shallow region at both sides of the hole. It was found that the effect of tangential traction is comparatively small on the stress concentration around the hole.

Effect of drinking-water administration of experimental chlorate ion preparations on Salmonella enterica serovar Typhimurium colonization in weaned and finished pigs.

PubMed

Anderson, R C; Hume, M E; Genovese, K J; Callaway, T R; Jung, Y S; Edrington, T S; Poole, T L; Harvey, R B; Bischoff, K M; Nisbet, D J

2004-04-01

Foodborne disease caused by Salmonella is of public health and economic significance. In order to assess the practical effectiveness of a new intervention strategy, experimental chlorate preparations (ECP) were administered via the drinking water to weaned and finished pigs that had been orally challenged the previous day with 10(9)-10(10) colony-forming units of Salmonella serovar Typhimurium. After 24 or 36 h ad libitum access to 0X, 1X or 2X ECP treatment (where X is the concentration estimated to deliver a minimal daily effective dose), the pigs were euthanized and gut contents and lymph tissue collected at necropsy were cultured for the challenge Salmonella. Drinking water administration of ECP effectively reduced (p < 0.05) caecal Salmonella concentrations and, with the weaned pigs, tended (p < or = 0.10) to reduce rectal Salmonella concentrations. No negative effects of ECP treatment on water intake and animal wellbeing were observed and only marginal effects on gut fermentation characteristics occurred. The bactericidal effect of administering ECP in drinking water was relatively rapid, with reductions in caecal Salmonella concentrations occurring within 24 h. These results suggest that ECP administered to pigs just days before slaughter may reduce gut concentrations of Salmonella; however, the impacts of such reductions on slaughter hygiene have yet to be determined.

Clinical Pharmacodynamics: Principles of Drug Response and Alterations in Kidney Disease.

PubMed

Keller, Frieder; Hann, Alexander

2018-05-16

Pharmacokinetics and pharmacodynamics follow the logic of cause and consequence. Receptor-mediated and reversible effects can be distinguished from direct and irreversible effects. Reversible effects are capacity-limited and saturable whereas irreversible effects are limited only by the number of viable targets. In the case of receptor-mediated and reversible effects a threshold and a ceiling concentration can be defined. Antimicrobial drugs with concentration-dependent action are distinguished from drugs with time-dependent action. Concentration-dependent effects are associated with a high ceiling concentration and the target is the high peak. Time-dependent effects are associated with a high threshold concentration and the target is the high trough. During kidney dysfunction, alterations of drug response are usually attributed to pharmacokinetic but rarely to pharmacodynamic changes. Dose adjustment calculations, therefore, tacitly presume that pharmacodynamic parameters remain unchanged while only pharmacokinetic parameters are altered in kidney failure. Kidney dysfunction influences the pharmacokinetic parameters of at least 50% of all essential drugs. Clinicians usually consider pharmacokinetics when kidney disease is found, but pharmacodynamics is as important. Alterations of pharmacodynamic parameters are conceivable but only rarely reported in kidney failure. Sometimes surprising dosing adjustments are needed when pharmacodynamic concepts are brought into the decision process of which dose to choose. Pharmacokinetics and pharmacodynamics should both be considered when any dosing regimen is determined. Copyright © 2018 by the American Society of Nephrology.