Determination of relative potencies for chemical inhibition of spontaneous neuronal activity using a four amplifier MEA system.

EPA Science Inventory

Potency determination is important to identify the most promising drug candidates as well as identification of and ranking of compound toxicity. In our laboratory, we have utilized MEA recording techniques to determine the relative potency of 11 insecticidal compounds and rank th...

21 CFR 660.22 - Potency requirements with reference preparations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Potency requirements with reference preparations. 660.22 Section 660.22 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN.... Products for which reference Blood Grouping Reagents are available shall have a potency titer value at...

21 CFR 660.22 - Potency requirements with reference preparations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Potency requirements with reference preparations. 660.22 Section 660.22 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN.... Products for which reference Blood Grouping Reagents are available shall have a potency titer value at...

21 CFR 640.56 - Quality control test for potency.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., Center for Biologics Evaluation and Research, Food and Drug Administration. Such testing shall not be... Evaluation and Research, Food and Drug Administration. (d) If the average potency level of antihemophilic... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Quality control test for potency. 640.56 Section...

Choline as an agonist: determination of its agonistic potency on cholinergic receptors.

PubMed

Ulus, I H; Millington, W R; Buyukuysal, R L; Kiran, B K

1988-07-15

These experiments examined the potency of choline as a cholinergic agonist at both muscarinic and nicotinic receptors in rat brain and peripheral tissues. Choline stimulated the contraction of isolated smooth muscle preparations of the stomach fundus, urinary bladder and trachea and reduced the frequency of spontaneous contractions of the right atrium at high micromolar and low millimolar concentrations. The potency of choline to elicit a biological response varied markedly among these tissues; EC50 values ranged between 0.41 mM in the fundus to 14.45 mM in the atrium. Choline also displaced [3H]quinuclidinyl benzilate binding in a concentration-dependent manner although, again, its potency varied among different brain regions (Ki = 1.2 to 3.5 mM) and peripheral tissues (Ki = 0.28 to 3.00 mM). Choline exhibited a comparable affinity for nicotinic receptors. It stimulated catecholamine release from the vascularly perfused adrenal gland (EC50 = 1.3 mM) and displaced L-[3H]nicotine binding to membrane preparations of brain and peripheral tissues (Ki = 0.38 to 1.17 mM). However, the concentration of choline required to bind to cholinergic receptors in most tissues was considerably higher than serum levels either in controls (8-13 microM) or following the administration of choline chloride (200 microM). These results clearly demonstrate that choline is a weak cholinergic agonist. Its potency is too low to account for the central nervous system effects produced by choline administration, although the direct activation of cholinergic receptors in several peripheral tissues may explain some of its side effects.

A new class of organic nitrates: investigations on bioactivation, tolerance and cross-tolerance phenomena.

PubMed

Schuhmacher, S; Schulz, E; Oelze, M; König, A; Roegler, C; Lange, K; Sydow, L; Kawamoto, T; Wenzel, P; Münzel, T; Lehmann, J; Daiber, A

2009-09-01

The chronic use of organic nitrates is limited by serious side effects including oxidative stress, nitrate tolerance and/or endothelial dysfunction. The side effects and potency of nitroglycerine depend on mitochondrial aldehyde dehydrogenase (ALDH-2). We sought to determine whether this concept can be extended to a new class of organic nitrates with amino moieties (aminoalkyl nitrates). Vasodilator potency of the organic nitrates, in vitro tolerance and in vivo tolerance (after continuous infusion for 3 days) were assessed in wild-type and ALDH-2 knockout mice by isometric tension studies. Mitochondrial oxidative stress was analysed by L-012-dependent chemiluminescence and protein tyrosine nitration. Aminoethyl nitrate (AEN) showed an almost similar potency to glyceryl trinitrate (GTN), even though it is only a mononitrate. AEN-dependent vasodilatation was mediated by cGMP and nitric oxide. In contrast to triethanolamine trinitrate (TEAN) and GTN, AEN bioactivation did not depend on ALDH-2 and caused no in vitro tolerance. In vivo treatment with TEAN and GTN, but not with AEN, induced cross-tolerance to acetylcholine (ACh)-dependent and GTN-dependent relaxation. Although all nitrates tested induced tolerance to themselves, only TEAN and GTN significantly increased mitochondrial oxidative stress in vitro and in vivo. The present results demonstrate that not all high potency nitrates are bioactivated by ALDH-2 and that high potency of a given nitrate is not necessarily associated with induction of oxidative stress or nitrate tolerance. Obviously, there are distinct pathways for bioactivation of organic nitrates, which for AEN may involve xanthine oxidoreductase rather than P450 enzymes.

The second international standard for polymyxin B.

PubMed

Lightbown, J W; Thomas, A H; Grab, B; Outschoorn, A S

1973-01-01

Since supplies of the first International Standard for Polymyxin B were exhausted, it was replaced by a second international standard the potency of which was estimated from the results of a collaborative assay carried out by 5 laboratories in 4 countries. The wide variations in the results probably resulted from difficulties experienced in handling the first international standard. The potency finally agreed upon by the collaborating laboratories, on the basis of the overall mean values obtained after rejection of the most discrepant assays, was 8 403 IU/mg. That value was accepted by the WHO Expert Committee on Biological Standardization (1970), which consequently defined the International Unit of polymyxin B as the activity contained in 0.000119 mg of the second international standard.

The second international standard for polymyxin B*

PubMed Central

Lightbown, J. W.; Thomas, A. H.; Grab, B.; Outschoorn, A. S.

1973-01-01

Since supplies of the first International Standard for Polymyxin B were exhausted, it was replaced by a second international standard the potency of which was estimated from the results of a collaborative assay carried out by 5 laboratories in 4 countries. The wide variations in the results probably resulted from difficulties experienced in handling the first international standard. The potency finally agreed upon by the collaborating laboratories, on the basis of the overall mean values obtained after rejection of the most discrepant assays, was 8 403 IU/mg. That value was accepted by the WHO Expert Committee on Biological Standardization (1970), which consequently defined the International Unit of polymyxin B as the activity contained in 0.000119 mg of the second international standard. PMID:4350877

Ability of Bruton's Tyrosine Kinase Inhibitors to Sequester Y551 and Prevent Phosphorylation Determines Potency for Inhibition of Fc Receptor but not B-Cell Receptor Signaling.

PubMed

Bender, Andrew T; Gardberg, Anna; Pereira, Albertina; Johnson, Theresa; Wu, Yin; Grenningloh, Roland; Head, Jared; Morandi, Federica; Haselmayer, Philipp; Liu-Bujalski, Lesley

2017-03-01

Bruton's tyrosine kinase (Btk) is expressed in a variety of hematopoietic cells. Btk has been demonstrated to regulate signaling downstream of the B-cell receptor (BCR), Fc receptors (FcRs), and toll-like receptors. It has become an attractive drug target because its inhibition may provide significant efficacy by simultaneously blocking multiple disease mechanisms. Consequently, a large number of Btk inhibitors have been developed. These compounds have diverse binding modes, and both reversible and irreversible inhibitors have been developed. Reported herein, we have tested nine Btk inhibitors and characterized on a molecular level how their interactions with Btk define their ability to block different signaling pathways. By solving the crystal structures of Btk inhibitors bound to the enzyme, we discovered that the compounds can be classified by their ability to trigger sequestration of Btk residue Y551. In cells, we found that sequestration of Y551 renders it inaccessible for phosphorylation. The ability to sequester Y551 was an important determinant of potency against FcεR signaling as Y551 sequestering compounds were more potent for inhibiting basophils and mast cells. This result was true for the inhibition of FcγR signaling as well. In contrast, Y551 sequestration was less a factor in determining potency against BCR signaling. We also found that Btk activity is regulated differentially in basophils and B cells. These results elucidate important determinants for Btk inhibitor potency against different signaling pathways and provide insight for designing new compounds with a broader inhibitory profile that will likely result in greater efficacy. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

N-terminal fatty acylated His-dPhe-Arg-Trp-NH(2) tetrapeptides: influence of fatty acid chain length on potency and selectivity at the mouse melanocortin receptors and human melanocytes.

PubMed

Todorovic, Aleksandar; Holder, Jerry Ryan; Bauzo, Rayna M; Scott, Joseph Walker; Kavanagh, Renny; Abdel-Malek, Zalfa; Haskell-Luevano, Carrie

2005-05-05

The melanocortin system is involved in the regulation of a diverse number of physiologically important pathways including pigmentation, feeding behavior, weight and energy homeostasis, inflammation, and sexual function. All the endogenous melanocortin agonist ligands possess the conserved His-Phe-Arg-Trp tetrapeptide sequence that is postulated to be important for melanocortin receptor molecular recognition and stimulation. Previous studies by our laboratory resulted in the discovery that increasing alkyl chain length at the N-terminal "capping" region of the His-dPhe-Arg-Trp-NH(2) tetrapeptide resulted in a 100-fold increased melanocortin receptor agonist potency. This study was undertaken to systematically evaluate the pharmacological effects of increasing N-capping alkyl chain length of the CH(3)(CH(2))(n)CO-His-dPhe-Arg-Trp-NH(2) (n = 6-16) tetrapeptide template. Twelve analogues were synthesized and pharmacologically characterized at the mouse melanocortin receptors MC1R and MC3R-MC5R and human melanocytes known to express the MC1R. These peptides demonstrated melanocortin receptor selectivity profiles different from those of previously published tetrapeptides. The most notable results of enhanced ligand potency (20- to 200-fold) and receptor selectivity were observed at the MC1R. Tetrapeptides that possessed greater than nine alkyl groups were superior to alpha-MSH in terms of the stimulation of human melanocyte tyrosinase activity. Additionally, the n-pentadecanoyl derivative had a residual effect on tyrosinase activity that existed for at least 4 days after the peptide was removed from the human melanocyte culture medium. These data demonstrate the utility, potency, and residual effect of melanocortin tetrapeptides by adding N-terminal fatty acid moieties.

The contribution of benzene to smoking-induced leukemia.

PubMed

Korte, J E; Hertz-Picciotto, I; Schulz, M R; Ball, L M; Duell, E J

2000-04-01

Cigarette smoking is associated with an increased risk of leukemia; benzene, an established leukemogen, is present in cigarette smoke. By combining epidemiologic data on the health effects of smoking with risk assessment techniques for low-dose extrapolation, we assessed the proportion of smoking-induced total leukemia and acute myeloid leukemia (AML) attributable to the benzene in cigarette smoke. We fit both linear and quadratic models to data from two benzene-exposed occupational cohorts to estimate the leukemogenic potency of benzene. Using multiple-decrement life tables, we calculated lifetime risks of total leukemia and AML deaths for never, light, and heavy smokers. We repeated these calculations, removing the effect of benzene in cigarettes based on the estimated potencies. From these life tables we determined smoking-attributable risks and benzene-attributable risks. The ratio of the latter to the former constitutes the proportion of smoking-induced cases attributable to benzene. Based on linear potency models, the benzene in cigarette smoke contributed from 8 to 48% of smoking-induced total leukemia deaths [95% upper confidence limit (UCL), 20-66%], and from 12 to 58% of smoking-induced AML deaths (95% UCL, 19-121%). The inclusion of a quadratic term yielded results that were comparable; however, potency models with only quadratic terms resulted in much lower attributable fractions--all < 1%. Thus, benzene is estimated to be responsible for approximately one-tenth to one-half of smoking-induced total leukemia mortality and up to three-fifths of smoking-related AML mortality. In contrast to theoretical arguments that linear models substantially overestimate low-dose risk, linear extrapolations from empirical data over a dose range of 10- to 100-fold resulted in plausible predictions.

Drimane Sesquiterpenoids Noncompetitively Inhibit Human α4β2 Nicotinic Acetylcholine Receptors with Higher Potency Compared to Human α3β4 and α7 Subtypes.

PubMed

Arias, Hugo R; Feuerbach, Dominik; Schmidt, Bernd; Heydenreich, Matthias; Paz, Cristian; Ortells, Marcelo O

2018-04-27

The drimane sesquiterpenoids drimenin, cinnamolide, dendocarbin A, and polygodial were purified from the Canelo tree ( Drimys winteri) and chemically characterized by spectroscopic methods. The pharmacological activity of these natural compounds were determined on hα4β2, hα3β4, and hα7 nicotinic acetylcholine receptors (AChRs) by Ca 2+ influx measurements. The results established that drimane sesquiterpenoids inhibit AChRs with the following selectivity: hα4β2 > hα3β4 > hα7. In the case of hα4β2 AChRs, the following potency rank order was determined (IC 50 's in μM): drimenin (0.97 ± 0.35) > cinnamolide (1.57 ± 0.36) > polygodial (62.5 ± 19.9) ≫ dendocarbin A (no activity). To determine putative structural features underlying the differences in inhibitory potency at hα4β2 AChRs, additional structure-activity relationship and molecular docking experiments were performed. The Ca 2+ influx and structural results supported a noncompetitive mechanism of inhibition, where drimenin interacted with luminal and nonluminal (TMD-β2 intrasubunit) sites. The structure-activity relationship results, i.e., the lower the ligand polarity, the higher the inhibitory potency, supported the nonluminal interaction. Ligand binding to both sites might inhibit the hα4β2 AChR by a cooperative mechanism, as shown experimentally ( n H > 1). Drimenin could be used as a molecular scaffold for the development of more potent inhibitors with higher selectivity for the hα4β2 AChR.

Mutagenicity of urine from individuals exposed to LPG combustion products.

PubMed

Yin, X J; Liu, J Z; Kong, X H; Chu, J H; Wang, H; Xiao, Z X

1998-09-01

The mutagenicity of urine from individuals exposed to the combustion products of liquefied petroleum gas (LPG) was detected with Salmonella typhimurium TA98 and its newly developed derivatives YG1021 (nitroreductase overproducing) and YG1024 (O-acetyltransferase overproducing). The detection showed significantly increased mutagenicity for the two YG strains and increased positive rates for all three strains in the presence of both rat liver S9 and beta-glucuronidase. Further analysis demonstrated that urine samples taken from smoking and non-smoking exposed individuals exhibited significantly higher mutagenic potency (revertants/10 microliters urine concentrate) than their corresponding controls. These results indicate that the increased urine mutagenicity is caused by the exposure to LPG combustion products or smoking. The mutagenic potency of urine samples of all exposed individuals tested with YG1024 was found to be about 7 times higher than with TA98. The difference in mutagenic potency was smaller for the same samples when comparison was made between YG1021 and TA98. This suggests that the mutagenic compounds present in the urine samples contain mainly aromatic compounds as glucuronide conjugates. Our results demonstrate that YG1024 is more sensitive than TA98 in detecting the mutagenicity of these samples. In addition, no significant difference in the mutagenic potency between the 'pure' exposed (non-smokers') and the 'pure' smokers' (unexposed) samples was found in all three tester strains. This might mean that the exposure extent of mutagens/carcinogens in LPG combustion products for exposed individuals roughly corresponds to the smoking level of smokers who smoke 20-40 cigarettes per day. Furthermore, the results also suggest that synergism might exist in the mutagenic effects of exposure to LPG combustion products and cigarette smoking.

Radiant power determination of low-level laser therapy equipment and characterization of its clinical use procedures.

PubMed

Guirro, Rinaldo Roberto de Jesus; Weis, Luciana Cezimbra

2009-08-01

The main objectives of this study were to characterize low-level laser therapy (LLLT) and the physical therapy clinical procedures for its use. There are few scientific studies that characterize the calibration of LLLT equipment. Forty lasers at 36 physical therapy clinics were selected. The equipment was characterized through data collected from the owner manuals, direct consultation with the manufacturers, and a questionnaire answered by the users. A digital potency analyzer was used to calibrate released mean potency. Qualitative data were presented throughout the descriptive statistics and quantitative data were analyzed by the Wilcoxon/Kruskal-Wallis and Fisher tests (significance, p < 0.05). The laser equipment was either AsGa (70.5%) or HeNe (23.5%), and 60% was analog and acquired over 5 years ago. The majority of the equipment was used 10-15 times per week and the most frequent density level used was 2 to 4 J/cm(2). Protective goggles were available in only 19.4% of the clinics evaluated. The association between the analyzed categories demonstrated that a lower mean potency was correlated both with equipment acquired over 5 years ago and analog technology. The determined mean potency was lower than the one claimed by the manufacturer (p < 0.05). In 30 cases, the analyzed equipment presented a potency between 3 microW and 5.6 mW; in three cases, the potency was >25 mW; and in seven cases, potency was nonexistent. The analyzed equipment was out-dated and periodical maintenance was not conducted, which was reflected in the low irradiated potency.

21 CFR 640.56 - Quality control test for potency.

Code of Federal Regulations, 2010 CFR

2010-04-01

... quality control test for potency may be performed by a clinical laboratory which meets the standards of... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Quality control test for potency. 640.56 Section...) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Cryoprecipitate § 640.56 Quality control...

21 CFR 660.4 - Potency test.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Potency test. 660.4 Section 660.4 Food and Drugs... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Antibody to Hepatitis B Surface Antigen § 660.4 Potency test. To be satisfactory for release, each filling of Antibody to Hepatitis B Surface Antigen...

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Potency test. 660.43 Section 660.43 Food and Drugs... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test... antibody in the appropriate sera of the reference panel by all test methods recommended by the manufacturer...

Epoxy resin monomers with reduced skin sensitizing potency.

PubMed

O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

2014-06-16

Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

Comparative sensitizing potencies of fragrances, preservatives, and hair dyes.

PubMed

Lidén, Carola; Yazar, Kerem; Johansen, Jeanne D; Karlberg, Ann-Therese; Uter, Wolfgang; White, Ian R

2016-11-01

The local lymph node assay (LLNA) is used for assessing sensitizing potential in hazard identification and risk assessment for regulatory purposes. Sensitizing potency on the basis of the LLNA is categorized into extreme (EC3 value of ≤0.2%), strong (>0.2% to ≤2%), and moderate (>2%). To compare the sensitizing potencies of fragrance substances, preservatives, and hair dye substances, which are skin sensitizers that frequently come into contact with the skin of consumers and workers, LLNA results and EC3 values for 72 fragrance substances, 25 preservatives and 107 hair dye substances were obtained from two published compilations of LLNA data and opinions by the Scientific Committee on Consumer Safety and its predecessors. The median EC3 values of fragrances (n = 61), preservatives (n = 19) and hair dyes (n = 59) were 5.9%, 0.9%, and 1.3%, respectively. The majority of sensitizing preservatives and hair dyes are thus strong or extreme sensitizers (EC3 value of ≤2%), and fragrances are mostly moderate sensitizers. Although fragrances are typically moderate sensitizers, they are among the most frequent causes of contact allergy. This indicates that factors other than potency need to be addressed more rigorously in risk assessment and risk management. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Alcohol's Effects on Lipid Bilayer Properties

PubMed Central

Ingólfsson, Helgi I.; Andersen, Olaf S.

2011-01-01

Alcohols are known modulators of lipid bilayer properties. Their biological effects have long been attributed to their bilayer-modifying effects, but alcohols can also alter protein function through direct protein interactions. This raises the question: Do alcohol's biological actions result predominantly from direct protein-alcohol interactions or from general changes in the membrane properties? The efficacy of alcohols of various chain lengths tends to exhibit a so-called cutoff effect (i.e., increasing potency with increased chain length, which that eventually levels off). The cutoff varies depending on the assay, and numerous mechanisms have been proposed such as: limited size of the alcohol-protein interaction site, limited alcohol solubility, and a chain-length-dependent lipid bilayer-alcohol interaction. To address these issues, we determined the bilayer-modifying potency of 27 aliphatic alcohols using a gramicidin-based fluorescence assay. All of the alcohols tested (with chain lengths of 1–16 carbons) alter the bilayer properties, as sensed by a bilayer-spanning channel. The bilayer-modifying potency of the short-chain alcohols scales linearly with their bilayer partitioning; the potency tapers off at higher chain lengths, and eventually changes sign for the longest-chain alcohols, demonstrating an alcohol cutoff effect in a system that has no alcohol-binding pocket. PMID:21843475

Collective efficacy, group potency, and group performance: meta-analyses of their relationships, and test of a mediation model.

PubMed

Stajkovic, Alexander D; Lee, Dongseop; Nyberg, Anthony J

2009-05-01

The authors examined relationships among collective efficacy, group potency, and group performance. Meta-analytic results (based on 6,128 groups, 31,019 individuals, 118 correlations adjusted for dependence, and 96 studies) reveal that collective efficacy was significantly related to group performance (.35). In the proposed nested 2-level model, collective efficacy assessment (aggregation and group discussion) was tested as the 1st-level moderator. It showed significantly different average correlations with group performance (.32 vs. .45), but the group discussion assessment was homogeneous, whereas the aggregation assessment was heterogeneous. Consequently, there was no 2nd-level moderation for the group discussion, and heterogeneity in the aggregation group was accounted for by the 2nd-level moderator, task interdependence (high, moderate, and low levels were significant; the higher the level, the stronger the relationship). The 2nd and 3rd meta-analyses indicated that group potency was related to group performance (.29) and to collective efficacy (.65). When tested in a structural equation modeling analysis based on meta-analytic findings, collective efficacy fully mediated the relationship between group potency and group performance. The authors suggest future research and convert their findings to a probability of success index to help facilitate practice. (c) 2009 APA, all rights reserved.

Three-dimensional quantitative structure-activity relationship analysis for human pregnane X receptor for the prediction of CYP3A4 induction in human hepatocytes: structure-based comparative molecular field analysis.

PubMed

Handa, Koichi; Nakagome, Izumi; Yamaotsu, Noriyuki; Gouda, Hiroaki; Hirono, Shuichi

2015-01-01

The pregnane X receptor [PXR (NR1I2)] induces the expression of xenobiotic metabolic genes and transporter genes. In this study, we aimed to establish a computational method for quantifying the enzyme-inducing potencies of different compounds via their ability to activate PXR, for the application in drug discovery and development. To achieve this purpose, we developed a three-dimensional quantitative structure-activity relationship (3D-QSAR) model using comparative molecular field analysis (CoMFA) for predicting enzyme-inducing potencies, based on computer-ligand docking to multiple PXR protein structures sampled from the trajectory of a molecular dynamics simulation. Molecular mechanics-generalized born/surface area scores representing the ligand-protein-binding free energies were calculated for each ligand. As a result, the predicted enzyme-inducing potencies for compounds generated by the CoMFA model were in good agreement with the experimental values. Finally, we concluded that this 3D-QSAR model has the potential to predict the enzyme-inducing potencies of novel compounds with high precision and therefore has valuable applications in the early stages of the drug discovery process. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

An “EAR” on environmental surveillance and monitoring: A case study on the use of Exposure–Activity Ratios (EARs) to prioritize sites, chemicals, and bioactivities of concern in Great Lakes waters

USGS Publications Warehouse

Blackwell, Brett R.; Ankley, Gerald T.; Corsi, Steven; DeCicco, Laura; Houck, Kieth A.; Judson, Richard S.; Li, Shibin; Martin, Matthew T.; Murphy, Elizabeth; Schroeder, Anthony L.; Smith, Edwin R.; Swintek, Joe; Villeneuve, Daniel L.

2017-01-01

Current environmental monitoring approaches focus primarily on chemical occurrence. However, based on concentration alone, it can be difficult to identify which compounds may be of toxicological concern and should be prioritized for further monitoring, in-depth testing, or management. This can be problematic because toxicological characterization is lacking for many emerging contaminants. New sources of high-throughput screening (HTS) data, such as the ToxCast database, which contains information for over 9000 compounds screened through up to 1100 bioassays, are now available. Integrated analysis of chemical occurrence data with HTS data offers new opportunities to prioritize chemicals, sites, or biological effects for further investigation based on concentrations detected in the environment linked to relative potencies in pathway-based bioassays. As a case study, chemical occurrence data from a 2012 study in the Great Lakes Basin along with the ToxCast effects database were used to calculate exposure–activity ratios (EARs) as a prioritization tool. Technical considerations of data processing and use of the ToxCast database are presented and discussed. EAR prioritization identified multiple sites, biological pathways, and chemicals that warrant further investigation. Prioritized bioactivities from the EAR analysis were linked to discrete adverse outcome pathways to identify potential adverse outcomes and biomarkers for use in subsequent monitoring efforts.

Herbs as an antioxidant arsenal for periodontal diseases

PubMed Central

Ramesh, Asha; Varghese, Sheeja Saji; Doraiswamy, Jayakumar Nadathur; Malaiappan, Sankari

2016-01-01

Herbal medicines have long been used as a traditional mode of therapy for various ailments in India. They are being used increasingly as dietary supplements to ward off common diseases. Periodontal diseases are highly prevalent and can affect up to 90% of the world population. Gingivitis is the mild form whereas periodontitis results in an irreversible loss of supporting structures of the teeth. Even though periodontal pathogens form a crucial component in the etiopathogenesis of periodontitis, there is a growing body of evidence suggesting oxidative stress playing a pivotal role in the disease initiation and progression. Studies have shown a direct correlation between increased levels of biomarkers for tissue damage induced by reactive oxygen species (ROS) to the severity of periodontal disease. Thus, the focus of attention has revolved back to herbal medicines due to their wide spectrum of biological and medicinal activities, lower costs, and higher safety margin. Internet databases Pubmed and Google Scholar were searched, and the most relevant articles were considered for review. This review briefly describes the various herbs with antioxidant capacity and their potency in the treating periodontal disease. PMID:27069730

The local lymph node assay compared with the human maximization test as an indicator of allergic potency in humans using patch test clinic populations.

PubMed

Zaghi, Danny; Maibach, Howard I

2009-01-01

The human maximization test (HMT) is a method to evaluate potency in humans, while the local lymph node assay (LLNA) is a test method that allows for the measuring of the allergic potency of a substance in a rodent. It has been proposed that an EC3 value (the value obtained by the LLNA test, ie, the concentration of an allergen leading to a 3-fold increase of baseline proliferation rate) would be a reliable indicator for a compound's allergic potency in humans. This paper compares the correlation between the EC3 value of a compound and its allergic occurrence in the general population with the correlation between the HMT of the compound and its allergic occurrence in the general population, to determine the relationship to potency. The correlation values when outliers were removed from the sample were -0.56 and -0.71 for LLNA and HMT, respectively, suggesting that there is a possible 20% error margin in LLNA's ability to predict potency. The data also suggest that other factors (such as exposure) could play up to a 30% role in the determination of allergic occurrence in the general population. The potency assays might be made more clinically relevant for predicting allergic frequencies by including a frequency factor and other factors in its dermatotoxicological interpretation.

Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

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

Bates, John T.; Keefer, Christopher J.; Slaughter, James C.

2014-04-15

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K{sub on}) for binding to RSV F protein, while alteration of dissociation rate (K{sub off}) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K{sub on}more » with reduced potency mirrored the effect of increased K{sub on} found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K{sub on}) correlated well with the potency of neutralization.« less

A DOG TEST FOR MEASURING THE IMMUNIZING POTENCY OF ANTIRABIES VACCINES

PubMed Central

Webster, Leslie T.; Casals, J.

1940-01-01

1. A quantitative method is described for testing the immunizing potency of antirabies vaccines in dogs. 2. Phenolized, single-injection, canine vaccines from seven manufacturers, when administered to dogs according to directions, failed to protect them against the least measurable amount of test virus fatal to 50 per cent or more of controls. Chloroformized vaccines from two of three manufacturers, under the same conditions, gave equivocal or suggestive results. 3. Commercial chloroformized vaccines in 10 cc. doses, injected intraperitoneally rather than subcutaneously into dogs, conferred a significant degree of immunity but proved temporarily irritative to the peritoneum. 4. These results of canine vaccines in dogs parallel closely those already reported in mice. PMID:19870993

A "methyl extension" strategy for polyketide natural product linker site validation and its application to dictyostatin.

PubMed

Ho, Stephen; Sackett, Dan L; Leighton, James L

2015-11-11

An approach to the validation of linker strategies for polyketide natural products with few or no obvious handles for linker attachment, and its application to dictyostatin, are described. Analogues in which the C(6)- and C(12)-methyl groups were replaced by 4-azidobutyl groups were prepared and shown to retain the low nanomolar potency of dictyostatin. Further, conjugation of the C(6) analogue with a cyclooctyne resulted in only minor attenuations in potency. Together, these results shed light on the binding of dictyostatin to β-tubulin, establish a validated linker strategy for dictyostatin, and set the stage for the synthesis and study of dictyostatin conjugates.

DEVELOPMENT OF A COMPARATIVE POTENCY METHOD FOR CANCER RISK ASSESSMENT OF COMPLEX MIXTURES USING SHORT-TERM 'IN VIVO' AND 'IN VITRO' BIOASSAYS

EPA Science Inventory

A comparative potency method for cancer risk assessment has been developed based upon a constant relative potency hypothesis. This method was developed and tested using data from a battery of short-term mutagenesis bioassays, animal tumorigenicity data and human lung cancer risk ...

Assessment of the sensitizing potency of preservatives with chance of skin contact by the loose-fit coculture-based sensitization assay (LCSA).

PubMed

Sonnenburg, Anna; Schreiner, Maximilian; Stahlmann, Ralf

2015-12-01

Parabens, methylisothiazolinone (MI) and its derivative methylchloroisothiazolinone (MCI), are commonly used as preservatives in personal care products. They can cause hypersensitivity reactions of the human skin. We have tested a set of nine parabens, MI alone and in combination with MCI in the loose-fit coculture-based sensitization assay (LCSA). The coculture of primary human keratinocytes and allogenic dendritic cell-related cells (DC-rc) in this assay emulates the in vivo situation of the human skin. Sensitization potency of the test substances was assessed by flow cytometric analysis of the DC-rc maturation marker CD86. Determination of the concentration required to cause a half-maximal increase in CD86-expression (EC50sens) allowed a quantitative evaluation. The cytotoxicity of test substances as indicator for irritative potency was measured by 7-AAD (7-amino-actinomycin D) staining. Parabens exhibited weak (methyl-, ethyl-, propyl- and isopropylparaben) or strong (butyl-, isobutyl-, pentyl- and benzylparaben) effects, whereas phenylparaben was found to be a moderate sensitizer. Sensitization potencies of parabens correlated with side chain length. Due to a pronounced cytotoxicity, we could not estimate an EC50sens value for MI, whereas MI/MCI was classified as sensitizer and also showed cytotoxic effects. Parabens showed no (methyl- and ethylparaben) or weak irritative potencies (propyl-, isopropyl-, butyl-, isobutyl-, phenyl- and benzylparaben), only pentylparaben was rated to be irritative. Overall, we were able to demonstrate and compare the sensitizing potencies of parabens in this in vitro test. Furthermore, we showed an irritative potency for most of the preservatives. The data further support the usefulness of the LCSA for comparison of the sensitizing potencies of xenobiotics.

In vitro and in vivo potency of insulin analogues designed for clinical use.

PubMed

Vølund, A; Brange, J; Drejer, K; Jensen, I; Markussen, J; Ribel, U; Sørensen, A R; Schlichtkrull, J

1991-11-01

Analogues of human insulin designed to have improved absorption properties after subcutaneous injection have been prepared by recombinant DNA technology. Five rapidly absorbed analogues, being predominantly in mono- or di-meric states in the pharmaceutical preparation, and a hexameric analogue with very low solubility at neutral pH and slow absorption, were studied. Receptor binding assays with HEP-G2 cells showed overall agreement with mouse free adipocyte assays. Two analogues, B28Asp and A21Gly + B27Arg + B30Thr-NH2, had nearly the same molar in vitro potency as human insulin. Another two showed increased adipocyte potency and receptor binding, B10Asp 194% and 333% and A8His + B4His + B10Glu + B27His 575% and 511%, while B9Asp + B27Glu showed 29% and 18% and the B25Asp analogue only 0.12% and 0.05% potency. Bioassays in mice or rabbits of the analogues except B25Asp showed that they had the same in vivo potency as human insulin 1.00 IU = 6.00 nmol. Thus the variation had the same in vivo potency as human insulin 1.00 IU = 6.00 nmol. Thus the variation in in vivo potency reflects the differences in receptor binding affinity. Relative to human insulin a low concentration is sufficient for a high affinity analogue to produce a given receptor complex formation and metabolic response. In conclusion, human insulin and analogues with markedly different in vitro potencies were equipotent in terms of hypoglycaemic effect. This is in agreement with the concept that elimination of insulin from blood and its subsequent degradation is mediated by insulin receptors.

Comparative In Vitro Toxicity Evaluation of Heavy Metals (Lead, Cadmium, Arsenic, and Methylmercury) on HT-22 Hippocampal Cell Line.

PubMed

Karri, Venkatanaidu; Kumar, Vikas; Ramos, David; Oliveira, Eliandre; Schuhmacher, Marta

2018-07-01

Heavy metals are considered some of the most toxic environmental pollutants. Exposure to heavy metals including lead (Pb), cadmium (Cd), arsenic (As), and methyl mercury (MeHg) has long been known to cause damage to human health. Many recent studies have supported the hippocampus as the major target for these four metals for inflicting cognitive dysfunction. In the present study, we proposed hippocampal relevant in vitro toxicity of Pb, Cd, As, and MeHg in HT-22 cell line. This study reports, initially, cytotoxic effects in acute, subchronic, chronic exposures. We further investigated the mechanistic potency of DNA damage and apoptosis damage with the observed cytotoxicity. The genotoxicity and apoptosis were measured by using the comet assay, annexin-V FTIC / propidium iodide (PI) assay, respectively. The results of cytotoxicity assay clearly demonstrated significant concentration and time-dependent effects on HT-22 cell line. The genotoxic and apoptosis effects also concentration-dependent fashion with respect to their potency in the range of IC 10 -IC 30, maximal level of damage observed in MeHg. In conclusion, the obtained result suggests concentration and potency-dependent response; the maximal level of toxicity was observed in MeHg. These novel findings support that Pb, Cd, As, and MeHg induce cytotoxic, genotoxic, and apoptotic effects on HT-22 cells in potency-dependent manner; MeHg> As> Cd> Pb. Therefore, the toxicity of Pb, Cd, As, and MeHg could be useful for knowing the common underlying molecular mechanism, and also for estimating the mixture impacts on HT-22 cell line.

Changes in Cannabis Potency over the Last Two Decades (1995-2014) - Analysis of Current Data in the United States

PubMed Central

ElSohly, Mahmoud A.; Mehmedic, Zlatko; Foster, Susan; Gon, Chandrani; Chandra, Suman; Church, James C.

2016-01-01

BACKGROUND Marijuana is the most widely used illicit drug in the United States and all over the world. Reports indicate that the potency of cannabis preparation has been increasing. This report examines the concentration of cannabinoids in illicit cannabis products seized by DEA (drug and enforcement administration) over the last two decades, with particular emphasis on Δ9-THC and cannabidiol (CBD). METHODS Samples in this report are received over time from DEA confiscated materials and processed for analysis using a validated ‘gas chromatograph with flame ionization detector (GC/FID)’ method. RESULTS A total of 38,681samples of cannabis preparations were received and analyzed between January 1, 1995 and December 31, 2014. The data showed that, while the number of marijuana samples seized over the last four years has declined, the number of sinsemilla samples has increased. Overall, the potency of illicit cannabis plant material has consistently risen over time since 1995 from approximately 4% in 1995 to approximately 12% in 2014. On the other hand, the CBD content has fallen on average from approximately 0.28% in 2001 to <0.15% in 2014, resulting in a change in the ratio of THC to CBD from 14 times in 1995 to approximately 80 times in 2014. CONCLUSION It is concluded that there is a shift in the production of illicit cannabis plant material from regular marijuana to sinsemilla. This increase in potency poses higher risk of cannabis use, particularly among adolescents. PMID:26903403

Specific Stereoisomeric Conformations Determine the Drug Potency of Cladosporin Scaffold against Malarial Parasite.

PubMed

Das, Pronay; Babbar, Palak; Malhotra, Nipun; Sharma, Manmohan; Jachak, Gorakhnath R; Gonnade, Rajesh G; Shanmugam, Dhanasekaran; Harlos, Karl; Yogavel, Manickam; Sharma, Amit; Reddy, D Srinivasa

2018-05-21

The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral centre anti-malarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme- and structure-based assays. We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency where changes at C3 are sensed by rotameric flipping of Glutamate332. Given that scores of anti-malarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of anti-microbial drug development.

Is it useful to add acetaminophen to high-potency opioids in cancer-related pain?

PubMed

Corsi, Oscar; Pérez-Cruz, Pedro E

2017-05-04

Pain is one of the most frequent and relevant symptoms in cancer patients. The World Health Organization's analgesic ladder proposes the use of strong opioids associated with adjuvants such as acetaminophen or nonsteroidal anti-inflammatory drugs in step III. However, it is unclear whether adding acetaminophen to an analgesic regimen based on strong opioids has any benefit in cancer patients with moderate to severe pain. To answer this question we searched in Epistemonikos database, which is maintained by screening multiple information sources. We identified two systematic reviews including five randomized trials overall. We extracted data and generated a summary of findings table using the GRADE approach. We concluded that adding acetaminophen to strong opioids might make little or no difference in improving pain management in cancer patients.

Derivation of an occupational exposure limit (OEL) for methylene chloride based on acute CNS effects and relative potency analysis.

PubMed

Storm, J E; Rozman, K K

1998-06-01

The Occupational Safety and Health Administration (OSHA) methylene chloride Permissible Exposure Level (PEL) or 25 ppm is quantitatively derived from mouse tumor results observed in a high-exposure National Toxicology Program bioassay. Because this approach depends on controversial interspecies and low-dose extrapolations, the PEL itself has stimulated heated debate. Here, an alternative safety assessment for methylene chloride is presented. It is based on an acute human lowest-observed-adverse-effect level (LOAEL) of 200 ppm for subtle central nervous system (CNS) depression. Steep, parallel exposure-response curves for anesthetic and subanesthetic CNS effects associated with compounds mechanistically and structurally related to methylene chloride are shown to support a safety factor of two to account for inter-individual variability in response. LOAEL/no-observed-adverse-effect ratios for subtle CNS effects associated with structurally related solvents are shown to support a safety factor range of two to four to account for uncertainty in identifying a subthreshold exposure level. Anesthetic relative potencies and anesthetic/subanesthetic effect level ratios are shown to be constant for the compounds evaluated, demonstrating that subanesthetic relative potencies are also constant. Relative potencies among similarly derived occupational exposure limits (OELs) for solvents structurally related to methylene chloride are therefore used to validate the derived methylene chloride OEL range of 25-50 ppm. Because this safety assessment is based on human (rather than rodent) data and empirical (rather than theoretical) exposure-response relationships and is supported by relative potency analysis, it is a defensible alternative to to the OSHA risk assessment and should positively contribute to the debate regarding the appropriate basis and value for a methylene chloride PEL.

The potency of fluvoxamine to reduce ethanol self-administration decreases with concurrent availability of food.

PubMed

Ginsburg, Brett C; Pinkston, Jonathan W; Lamb, Richard J

2012-04-01

The selective serotonin reuptake inhibitor fluvoxamine reduces responding for ethanol at lower doses than responding for food when each is available in separate components or separate groups of rats. However, when both are available concurrently and deliveries earned per session are equal, this apparent selectivity inverts and food-maintained behavior is more sensitive than ethanol-maintained behavior to rate-decreasing effects of fluvoxamine. Here, we investigated further the impact that concurrent access to both food and ethanol has on the potency of fluvoxamine. Fluvoxamine (5.6-17.8 mg/kg) potency was assessed under conditions in which food and ethanol were available concurrently and response rates were equal [average variable intervals (VIs) 405 and 14 s for food and ethanol, respectively], as well as when density of food delivery was increased (average VI 60 s for food and VI 14 s for ethanol). The potency of fluvoxamine was also determined when only ethanol was available (food extinction and average VI 14 s for ethanol) and under multiple VIs (VI 30 s for food and ethanol) wherein either food or ethanol was the only programmed reinforcement available during each component. Fluvoxamine was less potent at decreasing ethanol self-administration when food was available concurrently {ED50 [95% confidence limit (CL): 8.2 (6.5-10.3) and 10.7 (7.9-14.4)]} versus when ethanol was available in isolation [ED50: 4.0 (2.7-5.9) and 5.1 (4.3-6.0)]. Effects on food were similar under each condition in which food was available. The results demonstrate that the potency of fluvoxamine in reducing ethanol-maintained behavior depends on whether ethanol is available in isolation or in the context of concurrently scheduled food reinforcement.

Steroid-like compounds in Chinese medicines promote blood circulation via inhibition of Na+/K+-ATPase

PubMed Central

Chen, Ronald JY; Chung, Tse-yu; Li, Feng-yin; Yang, Wei-hung; Jinn, Tzyy-rong; Tzen, Jason TC

2010-01-01

Aim: To examine if steroid-like compounds found in many Chinese medicinal products conventionally used for the promotion of blood circulation may act as active components via the same molecular mechanism triggered by cardiac glycosides, such as ouabain. Methods: The inhibitory potency of ouabain and the identified steroid-like compounds on Na+/K+-ATPase activity was examined and compared. Molecular modeling was exhibited for the docking of these compounds to Na+/K+-ATPase. Results: All the examined steroid-like compounds displayed more or less inhibition on Na+/K+-ATPase, with bufalin (structurally almost equivalent to ouabain) exhibiting significantly higher inhibitory potency than the others. In the pentacyclic triterpenoids examined, ursolic acid and oleanolic acid were moderate inhibitors of Na+/K+-ATPase, and their inhibitory potency was comparable to that of ginsenoside Rh2. The relatively high inhibitory potency of ursolic acid or oleanolic acid was due to the formation of a hydrogen bond between its carboxyl group and the Ile322 residue in the deep cavity close to two K+ binding sites of Na+/K+-ATPase. Moreover, the drastic difference observed in the inhibitory potency of ouabain, bufalin, ginsenoside Rh2, and pentacyclic triterpenoids is ascribed mainly to the number of hydrogen bonds and partially to the strength of hydrophobic interaction between the compounds and residues around the deep cavity of Na+/K+-ATPase. Conclusion: Steroid-like compounds seem to contribute to therapeutic effects of many cardioactive Chinese medicinal products. Chinese herbs, such as Prunella vulgaris L, rich in ursolic acid, oleanolic acid and their glycoside derivatives may be adequate sources for cardiac therapy via effective inhibition on Na+/K+-ATPase. PMID:20523340

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (5)--Six-month repeated oral dose toxicity study and supplement study in rats].

PubMed

Sameshima, H; Omori, M; Nishimura, Y; Chihaya, Y; Itoh, F; Mizushima, Y; Yabuuchi, K; Ohno, K; Furukawa, H; Yoshida, I; Ueno, M; Yahara, I; Kato, I

2001-05-01

Cefmatilen hydrochloride hydrate (S-1090) was orally administered to rats at dose levels of 100, 300 and 1000 mg potency/kg once daily for 6 months. All the S-1090 treated groups showed soft feces, reddish-brown feces (due to chelated products of S-1090 or its decomposition products with Fe3+ in the diet), abdominal distention, increased food and water consumption, lower urine pH, and a decrease of white blood cells counts (except for males of the 100 mg potency/kg group). One male in the 300 mg potency/kg group showed mucous feces and marked decrease in body weight, and diet in the middle stage of the administration period. In necropsy of the survivors of all treated groups, marked cecal enlargement was noted. No remarkable changes were observed in the other examination items. From the early stage of the withdrawal period, animals in the 1000 mg potency/kg group showed again soft or mucous feces and a marked decrease in body weight. Of these animals, one male died and another male was sacrificed in a moribund state at about 2 weeks of the withdrawal period. Enterocolitis was observed in these cases. Almost all animals recovered within 3 weeks of withdrawal. A supplemental study of the 6-month toxicity study was conducted to examine the mechanisms of enterocolitis and the changes observable in the 100 or 300 mg potency/kg groups after drug withdrawal. As a reference, cefdinir (CFDN), an oral cephem antibiotic the same as S-1090, was added in the 1000 mg potency/kg group. No deaths occurred in any groups. Decreased intestinal flora were noted in all the groups treated with S-1090 or CFDN at the end of the dosing period. At 2 weeks of the withdrawal period, C. difficile and its D-1 toxin in the cecal contents were highly detected in the S-1090 300 and 1000 mg potency/kg groups and CFDN group. Inflammatory changes in the cecum and colon were observed in these groups. At 4 weeks of the withdrawal period, intestinal flora in the S-1090 groups almost returned to the condition before dosing, but those in the CFDN group were retained highly. Cecal D-1 toxin in the CFDN group was positive and higher than in the S-1090 groups. It was thus considered that the critical condition with enterocolitis resulted from C. difficile, which proliferated more rapidly than the other bacteria and D-1 toxin produced by this bacteria in the withdrawal period. Above changes were commonly observed in the CFDN group. The NOAEL of S-1090 was assessed to be 100 mg potency/kg/day which induced no enteritis.

Tautomerism, Hammett σ, and QSAR

NASA Astrophysics Data System (ADS)

Martin, Yvonne Connolly

2010-06-01

A consideration of equilibrium model-based equations suggests that tautomeric equilibria do not markedly affect observed potency if the tautomer bound represents at least 50% of the compound in solution. Tautomeric equilibria can enhance or attenuate the correlation of potency with Hammett σ. Additionally, tautomeric equilibria can lead to a correlation of potency with σ even in the absence of a correlation of binding with σ.

Quality of original and biosimilar epoetin products.

PubMed

Brinks, Vera; Hawe, Andrea; Basmeleh, Abdul H H; Joachin-Rodriguez, Liliana; Haselberg, Rob; Somsen, Govert W; Jiskoot, Wim; Schellekens, Huub

2011-02-01

To compare the quality of therapeutic erythropoietin (EPO) products, including two biosimilars, with respect to content, aggregation, isoform profile and potency. Two original products, Eprex (epoetin alpha) and Dynepo (epoetin delta), and two biosimilar products, Binocrit (epoetin alpha) and Retacrit (epoetin zeta), were compared using (1) high performance size exclusion chromatography, (2) ELISA, (3) SDS-PAGE, (4) capillary zone electrophoresis and (5) in-vivo potency. Tested EPO products differed in content, isoform composition, and potency. Of the tested products, the biosimilars have the same or even better quality as the originals. Especially, the potency of originals may significantly differ from the value on the label.

An analysis of 72% chromated glycerin used for sclerotherapy: sterility, potency, and cost after extended shelf life.

PubMed

Ghaznavi, Amir M; Nakamura, Mio; Tepper, Donna

2015-01-01

Sclerotherapy is the treatment of reticular veins and telangiectasias of the lower extremities. Sclerosants destroy endothelial tissue and expose subendothelial collagen fibers, which lead to subsequent fibrosis of vessels, thus preventing recanalization. There are several available sclerosants including sodium tetradecyl sulfate (STS), polidocanol (POL), and chromated glycerin (CG) with varying efficacy, potency, side effect profile, and cost. To identify the possible bacterial contamination and potency of CG beyond the current recommended shelf life of 3 months and to prove if CG is as cost effective as other available sclerosants. Samples of 72% CG underwent bacterial endotoxin, sterility, and potency analysis at Days 0, 24, and 183. In addition, cost comparison was performed with other commercially available sclerosants including STS and POL. No samples of CG showed any bacterial contamination. All aliquots of glycerin remained sterile at Day 14. Potency at Day 24 was 99.2%, which was the same at Day 183. Cost comparison with other sclerosants revealed that CG is lower cost per milliliter than STS and POL. Seventy-two percent CG has no contamination and maintains its reported potency up to 6 months while comparable with the cost of other commercially available sclerosants.

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (7)--Three-month repeated oral dose toxicity study in juvenile dogs].

PubMed

Sawada, T; Karaki, K; Hayashi, T; Yoneyama, S; Mizushima, Y; Moriyama, T; Nishimura, K; Kimura, Y; Nakano, M; Kato, I

2001-05-01

To evaluate the repeated oral dose toxicity of Cefmatilen hydrochloride hydrate (S-1090) in juvenile dogs, S-1090 was administered to juvenile beagle dogs at dose levels of 50, 100, 200 and 400 mg potency/kg/day for 3 months. No deaths occurred. Urinalysis in the 400 mg potency/kg group revealed positive reactions of occult blood and protein, and erythrocytes in sediments. Cystitis was observed in the 200 and 400 mg potency/kg groups. In the thyroids, an increased weight in some animals in the groups dosed at 100 mg potency/kg or more and an increased follicular colloid in the 400 mg potency/kg group were observed. However, no related changes were noted in other examination items. Red to dark-red feces (due to chelated products of S-1090 or its decomposition products with Fe3+ in the diet) were observed in all treated groups. Plasma S-1090 concentrations increased in a manner less than dose-proportional. The lesions of urinary bladder were judged as S-1090-induced toxic changes and the NOAEL of S-1090 in this study was assessed to be 100 mg potency/kg/day.

Graphical method for comparative statistical study of vaccine potency tests.

PubMed

Pay, T W; Hingley, P J

1984-03-01

Producers and consumers are interested in some of the intrinsic characteristics of vaccine potency assays for the comparative evaluation of suitable experimental design. A graphical method is developed which represents the precision of test results, the sensitivity of such results to changes in dosage, and the relevance of the results in the way they reflect the protection afforded in the host species. The graphs can be constructed from Producer's scores and Consumer's scores on each of the scales of test score, antigen dose and probability of protection against disease. A method for calculating these scores is suggested and illustrated for single and multiple component vaccines, for tests which do or do not employ a standard reference preparation, and for tests which employ quantitative or quantal systems of scoring.

The effectivenes of science domain-based science learning integrated with local potency

NASA Astrophysics Data System (ADS)

Kurniawati, Arifah Putri; Prasetyo, Zuhdan Kun; Wilujeng, Insih; Suryadarma, I. Gusti Putu

2017-08-01

This research aimed to determine the significant effect of science domain-based science learning integrated with local potency toward science process skills. The research method used was a quasi-experimental design with nonequivalent control group design. The population of this research was all students of class VII SMP Negeri 1 Muntilan. The sample of this research was selected through cluster random sampling, namely class VII B as an experiment class (24 students) and class VII C as a control class (24 students). This research used a test instrument that was adapted from Agus Dwianto's research. The aspect of science process skills in this research was observation, classification, interpretation and communication. The analysis of data used the one factor anova at 0,05 significance level and normalized gain score. The significance level result of science process skills with one factor anova is 0,000. It shows that the significance level < alpha (0,05). It means that there was significant effect of science domain-based science learning integrated with local potency toward science learning process skills. The results of analysis show that the normalized gain score are 0,29 (low category) in control class and 0,67 (medium category) in experiment class.

Granular Activated Carbon Treatment May Result in Higher Predicted Genotoxicity in the Presence of Bromide.

PubMed

Krasner, Stuart W; Lee, Tiffany Chih Fen; Westerhoff, Paul; Fischer, Natalia; Hanigan, David; Karanfil, Tanju; Beita-Sandí, Wilson; Taylor-Edmonds, Liz; Andrews, Robert C

2016-09-06

Certain unregulated disinfection byproducts (DBPs) are more of a health concern than regulated DBPs. Brominated species are typically more cytotoxic and genotoxic than their chlorinated analogs. The impact of granular activated carbon (GAC) on controlling the formation of regulated and selected unregulated DBPs following chlorine disinfection was evaluated. The predicted cyto- and genotoxicity of DBPs was calculated using published potencies based on the comet assay for Chinese hamster ovary cells (assesses the level of DNA strand breaks). Additionally, genotoxicity was measured using the SOS-Chromotest (detects DNA-damaging agents). The class sum concentrations of trihalomethanes, haloacetic acids, and unregulated DBPs, and the SOS genotoxicity followed the breakthrough of dissolved organic carbon (DOC), however the formation of brominated species did not. The bromide/DOC ratio was higher than the influent through much of the breakthrough curve (GAC does not remove bromide), which resulted in elevated brominated DBP concentrations in the effluent. Based on the potency of the haloacetonitriles and halonitromethanes, these nitrogen-containing DBPs were the driving agents of the predicted genotoxicity. GAC treatment of drinking or reclaimed waters with appreciable levels of bromide and dissolved organic nitrogen may not control the formation of unregulated DBPs with higher genotoxicity potencies.

Kinetic microplate bioassays for relative potency of antibiotics improved by partial Least Square (PLS) regression.

PubMed

Francisco, Fabiane Lacerda; Saviano, Alessandro Morais; Almeida, Túlia de Souza Botelho; Lourenço, Felipe Rebello

2016-05-01

Microbiological assays are widely used to estimate the relative potencies of antibiotics in order to guarantee the efficacy, safety, and quality of drug products. Despite of the advantages of turbidimetric bioassays when compared to other methods, it has limitations concerning the linearity and range of the dose-response curve determination. Here, we proposed to use partial least squares (PLS) regression to solve these limitations and to improve the prediction of relative potencies of antibiotics. Kinetic-reading microplate turbidimetric bioassays for apramacyin and vancomycin were performed using Escherichia coli (ATCC 8739) and Bacillus subtilis (ATCC 6633), respectively. Microbial growths were measured as absorbance up to 180 and 300min for apramycin and vancomycin turbidimetric bioassays, respectively. Conventional dose-response curves (absorbances or area under the microbial growth curve vs. log of antibiotic concentration) showed significant regression, however there were significant deviation of linearity. Thus, they could not be used for relative potency estimations. PLS regression allowed us to construct a predictive model for estimating the relative potencies of apramycin and vancomycin without over-fitting and it improved the linear range of turbidimetric bioassay. In addition, PLS regression provided predictions of relative potencies equivalent to those obtained from agar diffusion official methods. Therefore, we conclude that PLS regression may be used to estimate the relative potencies of antibiotics with significant advantages when compared to conventional dose-response curve determination. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel molecular imaging ligands targeting matrix metalloproteinases 2 and 9 for imaging of unstable atherosclerotic plaques

PubMed Central

Molenaar, Ger; de Waard, Vivian; Lutgens, Esther; van Eck-Smit, Berthe L. F.; de Bruin, Kora; Piek, Jan J.; Eersels, Jos L. H.; Booij, Jan; Verberne, Hein J.; Windhorst, Albert D.

2017-01-01

Molecular imaging of matrix metalloproteinases (MMPs) may allow detection of atherosclerotic lesions vulnerable to rupture. In this study, we develop a novel radiolabelled compound that can target gelatinase MMP subtypes (MMP2/9) with high selectivity and inhibitory potency. Inhibitory potencies of several halogenated analogues of MMP subtype-selective inhibitors (N-benzenesulfonyliminodiacetyl monohydroxamates and N-halophenoxy-benzenesulfonyl iminodiacetyl monohydroxamates) were in the nanomolar range for MMP2/9. The analogue with highest inhibitory potency and selectivity was radiolabelled with [123I], resulting in moderate radiochemical yield, and high radiochemical purity. Biodistribution studies in mice, revealed stabilization in blood 1 hour after intravenous bolus injection. Intravenous infusion of the radioligand and subsequent autoradiography of excised aortas showed tracer uptake in atheroprone mice. Distribution of the radioligand showed co-localization with MMP2/9 immunohistochemical staining. In conclusion, we have developed a novel selective radiolabeled MMP2/9 inhibitor, suitable for single photon emission computed tomography (SPECT) imaging that effectively targets atherosclerotic lesions in mice. PMID:29190653

Identification of the functional binding pocket for compounds targeting small-conductance Ca2+-activated potassium channels

PubMed Central

Zhang, Miao; Pascal, John M.; Schumann, Marcel; Armen, Roger S.; Zhang, Ji-fang

2012-01-01

Small- and intermediate-conductance Ca2+-activated potassium channels, activated by Ca2+-bound calmodulin, play an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels. However, these compounds often suffer from low potency and lack of selectivity, hindering their potentials for clinical use. A key contributing factor is the lack of knowledge of the binding site(s) for these compounds. Here we demonstrate by X-ray crystallography that the binding pocket for the compounds of the 1-EBIO class is located at the calmodulin-channel interface. We show that, based on structure data and molecular docking, mutations of the channel can effectively change the potency of these compounds. Our results provide insight into the molecular nature of the binding pocket and its contribution to the potency and selectivity of the compounds of the 1-EBIO class. PMID:22929778

Identification of the functional binding pocket for compounds targeting small-conductance Ca²⁺-activated potassium channels.

PubMed

Zhang, Miao; Pascal, John M; Schumann, Marcel; Armen, Roger S; Zhang, Ji-Fang

2012-01-01

Small- and intermediate-conductance Ca(2+)-activated potassium channels, activated by Ca(2+)-bound calmodulin, have an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels. However, these compounds often suffer from low potency and lack of selectivity, hindering their potential for clinical use. A key contributing factor is the lack of knowledge of the binding site(s) for these compounds. Here we demonstrate by X-ray crystallography that the binding pocket for the compounds of the 1-ethyl-2-benzimidazolinone (1-EBIO) class is located at the calmodulin-channel interface. We show that, based on structure data and molecular docking, mutations of the channel can effectively change the potency of these compounds. Our results provide insight into the molecular nature of the binding pocket and its contribution to the potency and selectivity of the compounds of the 1-EBIO class.

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (6)--Six-month repeated oral dose toxicity study in dogs].

PubMed

Sameshima, H; Ueda, T; Haruyama, E; Chihaya, Y; Mizushima, Y; Ueno, M; Moriyama, T; Kii, Y; Kato, I

2001-05-01

A six-month repeated oral dose toxicity study of Cefmatilen hydrochloride hydrate (S-1090) at dose levels of 40, 100 and 250 mg potency/kg/day was conducted in male and female beagle dogs. No toxicologically significant changes were observed in general conditions of all animals. Reddish-brown feces (due to chelated products of S-1090 or its decomposition products with Fe3+ in the diet) were observed in all treated groups. Plasma irons showed a tendency to increase in the males and females of the 250 mg potency/kg group. However, as no changes suggesting anemia or hepatic injury were observed in this group, the change of plasma iron was considered to have no toxicological significance. No toxicologically significant changes were observed in other examination items. The plasma S-1090 concentrations increased in a manner less than dose-proportional. Based on the above results, the NOAEL of S-1090 was assessed to be 250 mg potency/kg/day.

Confidence limit calculation for antidotal potency ratio derived from lethal dose 50

PubMed Central

Manage, Ananda; Petrikovics, Ilona

2013-01-01

AIM: To describe confidence interval calculation for antidotal potency ratios using bootstrap method. METHODS: We can easily adapt the nonparametric bootstrap method which was invented by Efron to construct confidence intervals in such situations like this. The bootstrap method is a resampling method in which the bootstrap samples are obtained by resampling from the original sample. RESULTS: The described confidence interval calculation using bootstrap method does not require the sampling distribution antidotal potency ratio. This can serve as a substantial help for toxicologists, who are directed to employ the Dixon up-and-down method with the application of lower number of animals to determine lethal dose 50 values for characterizing the investigated toxic molecules and eventually for characterizing the antidotal protections by the test antidotal systems. CONCLUSION: The described method can serve as a useful tool in various other applications. Simplicity of the method makes it easier to do the calculation using most of the programming software packages. PMID:25237618

Resorcinol-, catechol- and saligenin-based bronchodilating β2-agonists as inhibitors of human cholinesterase activity.

PubMed

Bosak, Anita; Knežević, Anamarija; Gazić Smilović, Ivana; Šinko, Goran; Kovarik, Zrinka

2017-12-01

We investigated the influence of bronchodilating β2-agonists on the activity of human acetylcholinesterase (AChE) and usual, atypical and fluoride-resistant butyrylcholinesterase (BChE). We determined the inhibition potency of racemate and enantiomers of fenoterol as a resorcinol derivative, isoetharine and epinephrine as catechol derivatives and salbutamol and salmeterol as saligenin derivatives. All of the tested compounds reversibly inhibited cholinesterases with K i constants ranging from 9.4 μM to 6.4 mM and had the highest inhibition potency towards usual BChE, but generally none of the cholinesterases displayed any stereoselectivity. Kinetic and docking results revealed that the inhibition potency of the studied compounds could be related to the size of the hydroxyaminoethyl chain on the benzene ring. The additional π-π interaction of salmeterol's benzene ring and Trp286 and hydrogen bond with His447 probably enhanced inhibition by salmeterol which was singled out as the most potent inhibitor of all the cholinesterases.

Design, synthesis, and preliminary pharmacological evaluation of 1, 4-diazabicyclo[4.3.0]nonan-9-ones as a new class of highly potent nootropic agents.

PubMed

Manetti, D; Ghelardini, C; Bartolini, A; Bellucci, C; Dei, S; Galeotti, N; Gualtieri, F; Romanelli, M N; Scapecchi, S; Teodori, E

2000-05-18

Several 4-substituted 1,4-diazabicyclo[4.3.0]nonan-9-ones have been synthesized and tested in vivo on mouse passive avoidance test, to evaluate their nootropic activity. The results show that they represent a new class of nootropic drugs with a pharmacological profile very similar to that of piracetam, showing much higher potency with respect to the reference. Among the compounds studied, 7 (DM 232) shows outstanding potency, being active at the dose of 0. 001 mg kg(-1) sc.

The 2005 World Health Organization Re-evaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins and Dioxin-like Compounds

PubMed Central

van den Berg, Martin; Birnbaum, Linda S.; Denison, Michael; De Vito, Mike; Farland, William; Feeley, Mark; Fiedler, Heidelore; Hakansson, Helen; Hanberg, Annika; Haws, Laurie; Rose, Martin; Safe, Stephen; Schrenk, Dieter; Tohyama, Chiharu; Tritscher, Angelika; Tuomisto, Jouko; Tysklind, Mats; Walker, Nigel; Peterson, Richard E.

2007-01-01

In June 2005 a WHO-IPCS expert meeting was held in Geneva during which the toxic equivalency factors (TEFs) for dioxin like compounds, including some polychlorinated biphenyls (PCBs), were re-evaluated. For this re-evaluation process the refined TEF database recently published by Haws and coworkers (Toxicol. Sci. 2006, 89:4-30) was used as a starting point. Decisions about a TEF value were made based on a combination of unweighted relative effect potency (REP) distributions from this database, expert judgement and point estimates. Previous TEFs were assigned in increments of 0.01, 0.05, 0.1, etc., but for this re-evaluation it was decided to use half order of magnitude increments on a logarithmic scale of 0.03, 0.1, 0.3 etc. Changes were decided by the expert panel for 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) (TEF=0.3), 1,2,3,7,8-pentachlorodibenzofuran (PeCDF) (TEF=0.03), octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) (TEFs=0.0003), 3,4,4’,5-tetrachlorbiphenyl (PCB 81) (TEF=0.0003), 3,3’,4,4’,5,5’-hexachlorobiphenyl (PCB 169) (TEF=0.03) and a single TEF value (0.00003) for all relevant mono-ortho substituted PCBs. Additivity, an important prerequisite of the TEF concept was again confirmed by results from recent in vivo mixture studies. Some experimental evidence shows that nondioxin-like aryl hydrocarbon receptor (AhR) agonists/antagonists are able to impact the overall toxic potency of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds and this needs to be investigated further. Certain individual and groups of compounds were identified for possible future inclusion in the TEF concept, including 3,4,4’-TCB (PCB 37), polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs), mixed polyhalogenated dibenzo-p-dioxins and dibenzofurans, polyhalogenated naphthalenes and polybrominated biphenyls (PBBs). Concern was expressed about direct application of the TEF/TEQ approach to abiotic matrices such as soil, sediment etc., for direct application in human risk assessment. This is problematic, as the present TEF scheme and TEQ methodology is primarily intended for estimating exposure and risks via oral ingestion (e.g., by dietary intake). A number of future approaches to determine alternative or additional TEFs were also identified. These included the use of a probabilistic methodology to determine TEFs that better describe the associated levels of uncertainty and ‘systemic’ TEFs for blood and adipose tissue and total toxic equivalency (TEQ) for body burden. PMID:16829543

Comparison of the relative airways and systemic potencies of inhaled fenoterol and salbutamol in asthmatic patients.

PubMed Central

Lipworth, B. J.; Newnham, D. M.; Clark, R. A.; Dhillon, D. P.; Winter, J. H.; McDevitt, D. G.

1995-01-01

BACKGROUND--There is controversy as to the relative safety of fenoterol and salbutamol. No differences have been found in the relative cardiac beta 1/beta 2 receptor activity of inhaled fenoterol and salbutamol in normal subjects. These initial findings have been extended by comparing the respective potencies of equivalent doses by weight of fenoterol and salbutamol in asthmatic subjects, in terms of airways and systemic responses. METHODS--Eighteen asthmatic patients of mean (SD) age 40 (14) years and a forced expiratory volume in one second (FEV1)% predicted of 56 (14)% (1.97 (0.66)1) were randomised to inhale fenoterol (100 micrograms/puff or 200 micrograms/puff), salbutamol, or placebo (100 micrograms/puff or 200 micrograms/puff) on three separate days. Dose-response curves were constructed using cumulative doses of 100 micrograms, 200 micrograms, 400 micrograms, 1000 micrograms, 2000 micrograms, and 4000 micrograms, and airways and systemic responses were measured 20 minutes after each dose with 40 minute increments. Dose ratios for the relative potency of fenoterol versus salbutamol were calculated from the dose-response curves using regression analysis of parallel slopes. RESULTS--There was no difference in bronchodilator potency between fenoterol and salbutamol (as median dose ratio): FEV1 1.1 (95% CI 0.4 to 4.6). In contrast, dose ratios for systemic responses showed that fenoterol was more potent than salbutamol: serum potassium 3.7 (95% CI 2.0 to 6.0), tremor 5.7 (95% CI 1.4 to 10.2), heart rate 1.6 (95% CI 1.0 to 2.3). At a conventional dose of 200 micrograms the only difference in response between the two drugs was observed for tremor (as mean difference): 0.23 log units (95% CI 0.06 to 0.41 log units). CONCLUSIONS--There was no difference in the bronchodilator potency between fenoterol and salbutamol on a microgram equivalent basis. In contrast, systemic potency was greater with fenoterol, although this difference was not clinically relevant at conventional dosages up to 200 micrograms. PMID:7886650

In silico modelling of thiazolidine derivatives with antioxidant potency: Models quantify the degree of contribution of molecular fragments towards the free radical scavenging ability

NASA Astrophysics Data System (ADS)

De, Biplab; Adhikari, Indrani; Nandy, Ashis; Saha, Achintya; Goswami, Binoy Behari

2017-06-01

Design and development of antioxidant supplements constitute an essential aspect of research in order to derive molecules that would help to combat the free radical invasion to the human body and curb oxidative stress related diseases. The present work deals with the development of in silico models for a series of thiazolidine derivatives having antioxidant potential. The objective of the work is to obtain models that would help to design new thazolidine derivatives based on substituent modification and thereby predict their activity profile. The QSAR model thus developed helps in quantification of the extent of contribution of the various molecular fragments towards the activity of the molecules, while the 3D pharmacophore model provides a brief idea of the essential molecular features that help the molecules to interact with the neighbouring free radicals. Both the models have been extensively validated which ensures their predictive ability as well the potential to search molecular databases for selection of thiazolidine derivatives with potent antioxidant activity. The models can thus be utilised effectively for database searching with the aim to isolate active antioxidants belonging to the thiazolidine group.

Ligand-based 3D QSAR analysis of reactivation potency of mono- and bis-pyridinium aldoximes toward VX-inhibited rat acetylcholinesterase.

PubMed

Dolezal, Rafael; Korabecny, Jan; Malinak, David; Honegr, Jan; Musilek, Kamil; Kuca, Kamil

2015-03-01

To predict unknown reactivation potencies of 12 mono- and bis-pyridinium aldoximes for VX-inhibited rat acetylcholinesterase (rAChE), three-dimensional quantitative structure-activity relationship (3D QSAR) analysis has been carried out. Utilizing molecular interaction fields (MIFs) calculated by molecular mechanical (MMFF94) and quantum chemical (B3LYP/6-31G*) methods, two satisfactory ligand-based CoMFA models have been developed: 1. R(2)=0.9989, Q(LOO)(2)=0.9090, Q(LTO)(2)=0.8921, Q(LMO(20%))(2)=0.8853, R(ext)(2)=0.9259, SDEP(ext)=6.8938; 2. R(2)=0.9962, Q(LOO)(2)=0.9368, Q(LTO)(2)=0.9298, Q(LMO(20%))(2)=0.9248, R(ext)(2)=0.8905, SDEP(ext)=6.6756. High statistical significance of the 3D QSAR models has been achieved through the application of several data noise reduction techniques (i.e. smart region definition SRD, fractional factor design FFD, uninformative/iterative variable elimination UVE/IVE) on the original MIFs. Besides the ligand-based CoMFA models, an alignment molecular set constructed by flexible molecular docking has been also studied. The contour maps as well as the predicted reactivation potencies resulting from 3D QSAR analyses help better understand which structural features are associated with increased reactivation potency of studied compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

Förster resonance energy transfer competitive displacement assay for human soluble epoxide hydrolase

PubMed Central

Lee, Kin Sing Stephen; Morisseau, Christophe; Yang, Jun; Wang, Peng; Hwang, Sung Hee; Hammock, Bruce D.

2013-01-01

The soluble epoxide hydrolase (sEH), responsible for the hydrolysis of various fatty acid epoxides to their corresponding 1,2-diols, is becoming an attractive pharmaceutical target. These fatty acid epoxides, particularly epoxyeicosatrienoic acids (EETs), play an important role in human homeostatic and inflammation processes. Therefore, inhibition of human sEH, which stabilizes EETs in vivo, brings several beneficial effects to human health. Although there are several catalytic assays available to determine the potency of sEH inhibitors, measuring the in vitro inhibition constant (Ki) for these inhibitors using catalytic assay is laborious. In addition, koff, which has been recently suggested to correlate better with the in vivo potency of inhibitors, has never been measured for sEH inhibitors. To better measure the potency of sEH inhibitors, a reporting ligand, 1-(adamantan-1-yl)-3-(1-(2-(7-hydroxy-2-oxo-2H-chromen-4-yl)acetyl) piperidin-4-yl)urea (ACPU), was designed and synthesized. With ACPU, we have developed a Förster resonance energy transfer (FRET)-based competitive displacement assay using intrinsic tryptophan fluorescence from sEH. In addition, the resulting assay allows us to measure the Ki values of very potent compounds to the picomolar level and to obtain relative koff values of the inhibitors. This assay provides additional data to evaluate the potency of sEH inhibitors. PMID:23219719

In vitro immunotherapy potency assays using real-time cell analysis

PubMed Central

Cerignoli, Fabio; Abassi, Yama A.; Lamarche, Brandon J.; Guenther, Garret; Santa Ana, David; Guimet, Diana; Zhang, Wen; Zhang, Jing

2018-01-01

A growing understanding of the molecular interactions between immune effector cells and target tumor cells, coupled with refined gene therapy approaches, are giving rise to novel cancer immunotherapeutics with remarkable efficacy in the clinic against both solid and liquid tumors. While immunotherapy holds tremendous promise for treatment of certain cancers, significant challenges remain in the clinical translation to many other types of cancers and also in minimizing adverse effects. Therefore, there is an urgent need for functional potency assays, in vitro and in vivo, that could model the complex interaction of immune cells with tumor cells and can be used to rapidly test the efficacy of different immunotherapy approaches, whether it is small molecule, biologics, cell therapies or combinations thereof. Herein we report the development of an xCELLigence real-time cytolytic in vitro potency assay that uses cellular impedance to continuously monitor the viability of target tumor cells while they are being subjected to different types of treatments. Specialized microtiter plates containing integrated gold microelectrodes enable the number, size, and surface attachment strength of adherent target tumor cells to be selectively monitored within a heterogeneous mixture that includes effector cells, antibodies, small molecules, etc. Through surface-tethering approach, the killing of liquid cancers can also be monitored. Using NK92 effector cells as example, results from RTCA potency assay are very well correlated with end point data from image-based assays as well as flow cytometry. Several effector cells, i.e., PBMC, NK, CAR-T were tested and validated as well as biological molecules such as Bi-specific T cell Engagers (BiTEs) targeting the EpCAM protein expressed on tumor cells and blocking antibodies against the immune checkpoint inhibitor PD-1. Using the specifically designed xCELLigence immunotherapy software, quantitative parameters such as KT50 (the amount of time it takes to kill 50% of the target tumor cells) and % cytolysis are calculated and used for comparing the relative efficacy of different reagents. In summary, our results demonstrate the xCELLigence platform to be well suited for potency assays, providing quantitative assessment with high reproducibility and a greatly simplified work flow. PMID:29499048

Single-cell entropy for accurate estimation of differentiation potency from a cell's transcriptome

NASA Astrophysics Data System (ADS)

Teschendorff, Andrew E.; Enver, Tariq

2017-06-01

The ability to quantify differentiation potential of single cells is a task of critical importance. Here we demonstrate, using over 7,000 single-cell RNA-Seq profiles, that differentiation potency of a single cell can be approximated by computing the signalling promiscuity, or entropy, of a cell's transcriptome in the context of an interaction network, without the need for feature selection. We show that signalling entropy provides a more accurate and robust potency estimate than other entropy-based measures, driven in part by a subtle positive correlation between the transcriptome and connectome. Signalling entropy identifies known cell subpopulations of varying potency and drug resistant cancer stem-cell phenotypes, including those derived from circulating tumour cells. It further reveals that expression heterogeneity within single-cell populations is regulated. In summary, signalling entropy allows in silico estimation of the differentiation potency and plasticity of single cells and bulk samples, providing a means to identify normal and cancer stem-cell phenotypes.

Osteogenic potency of a 3-dimensional scaffold-free bonelike sphere of periodontal ligament stem cells in vitro.

PubMed

Singhatanadgit, Weerachai; Varodomrujiranon, Manatsanan

2013-12-01

The present study aimed to investigate the osteogenic potency of scaffold-free 3-dimensional (3D) spheres of periodontal ligament stem cells (PDLSCs). The osteogenic potency of PDLSC spheres was determined by the ability to form mineralization and to express key osteogenesis-associated genes. The alkaline phosphatase (ALP) activity and the protein content of PDLSC spheres were also measured. The 3D sphere developed its osteogenic potency in a time-dependent manner, containing approximately 10-fold higher mineralization, 5-fold higher protein content, and 4-fold greater ALP activity than those in the controls. The expression of key osteogenic genes was also upregulated in the 3D PDLSC spheres. Cellular outgrowth was observed when reintroduced into 2D culture. PDLSCs were able to undergo osteogenic differentiation in a scaffold-free 3D culture, producing bonelike mineralization in vitro. This suggests, at least in vitro, the osteogenic potency of the 3D PDLSC spheres. Copyright © 2013 Elsevier Inc. All rights reserved.

Single-cell entropy for accurate estimation of differentiation potency from a cell's transcriptome

PubMed Central

Teschendorff, Andrew E.; Enver, Tariq

2017-01-01

The ability to quantify differentiation potential of single cells is a task of critical importance. Here we demonstrate, using over 7,000 single-cell RNA-Seq profiles, that differentiation potency of a single cell can be approximated by computing the signalling promiscuity, or entropy, of a cell's transcriptome in the context of an interaction network, without the need for feature selection. We show that signalling entropy provides a more accurate and robust potency estimate than other entropy-based measures, driven in part by a subtle positive correlation between the transcriptome and connectome. Signalling entropy identifies known cell subpopulations of varying potency and drug resistant cancer stem-cell phenotypes, including those derived from circulating tumour cells. It further reveals that expression heterogeneity within single-cell populations is regulated. In summary, signalling entropy allows in silico estimation of the differentiation potency and plasticity of single cells and bulk samples, providing a means to identify normal and cancer stem-cell phenotypes. PMID:28569836

An integrated evidence-based targeting strategy for determining combinatorial bioactive ingredients of a compound herbal medicine Qishen Yiqi dripping pills.

PubMed

Zhang, Yiqian; Yu, Jiahui; Zhang, Wen; Wang, Yuewei; He, Yi; Zhou, Shuiping; Fan, Guanwei; Yang, Hua; Zhu, Yan; Li, Ping

2018-06-12

Qishen Yiqi is a widely used Chinese herbal medicine formula with "qi invigorating and blood activating" property. Its dripping pill preparation (QSYQ) is a commercial herbal medicine approved by the China Food and Drug Administration (CFDA) in 2003 and is extensively used clinically to treat cardiovascular diseases, such as ischemic heart failure and angina pectoris, as well as for the secondary prevention of myocardial infarction. However, the bioactive ingredients of QSYQ remain unclear. As QSYQ is a compound herbal formula, it is of great importance to elucidate its pharmacologically active ingredients and underlying synergetic effects. This experimental study was conducted to comprehensively determine the combinatorial bioactive ingredients (CBIs) in QSYQ and to elucidate their potential synergetic effects. The established strategy may shed new light on how to rapidly determine CBIs in complex herbal formulas with holistic properties. An integrated evidence-based targeting strategy was introduced and validated to determine CBIs in QSYQ. The strategy included the following steps: (1) Chemical ingredients in QSYQ were analyzed via UPLC-Q-TOF/MS in the negative and positive modes and were identified by comparison with standard compounds and previously reported data. Their potential therapeutic activities were predicted based on the ChEMBL database to preliminarily search for candidate bioactive ingredients, and their combination was defined as the CBIs. (2) The CBIs were directly trapped and prepared from QSYQ with a two-dimensional chromatographic separation system, and the remaining part was defined as the rest ingredients (RIs). (3) As animal and cell models, left anterior descending coronary artery ligation (LAD)-induced heart failure in rats and hypoxia-induced cardiac myocyte injury in H9c2 cells were applied to compare the potency of QSYQ, CBIs and RIs. (4) The synergetic effects on cardiac myocyte protection of multiple ingredients in CBIs were examined in this cell model. (1) Forty-three ingredients in QSYQ were identified via UPLC-Q-TOF/MS. Based on evidence-based screening using the ChEMBL database, 24 ingredients were predicted to be bioactive ingredients, and their combination was considered the CBIs. (2) The CBIs and RIs were successfully prepared according to a two-dimensional chromatographic system. The CBIs were directly trapped and knocked out from QSYQ by hydrophilic interaction liquid chromatography coupled with reverse-phase liquid chromatography. The remaining part was used as RIs. (3) The results from pharmacological evaluation revealed that CBIs and QSYQ, but not RIs, significantly prevented myocardium injury; improved the ejection fraction (EF) and fractional shortening (FS); decreased the release of cardiac enzymes, including CK, CK-MB, and LDH; alleviated mitochondrial dysfunction; and protected the cell nucleus number and mitochondrial mass. Furthermore, QSYQ and CBIs possessed similar potency. (4) In hypoxia-stimulated H9c2 cells, CBIs showed far greater potency regarding the protection of cardiac myocyte injury than the individual ingredients in QSYQ, exhibiting obvious synergetic effects. An integrated evidence-based targeting strategy was successfully established and validated to determine CBIs from QSYQ with excellent efficiency. Importantly, the holistic property of QSYQ was retained in the CBIs. Hence, this study may shed new light on how to rapidly reveal combinatorial bioactive ingredients from complex prescriptions and will be greatly helpful in the establishment of an appropriate approach to quality control for herbal medicines. Copyright © 2018 Elsevier B.V. All rights reserved.

The local lymph node assay and the assessment of relative potency: status of validation.

PubMed

Basketter, David A; Gerberick, Frank; Kimber, Ian

2007-08-01

For the prediction of skin sensitization potential, the local lymph node assay (LLNA) is a fully validated alternative to guinea-pig tests. More recently, information from LLNA dose-response analyses has been used to assess the relative potency of skin sensitizing chemicals. These data are then deployed for risk assessment and risk management. In this commentary, the utility and validity of these relative potency measurements are reviewed. It is concluded that the LLNA does provide a valuable assessment of relative sensitizing potency in the form of the estimated concentration of a chemical required to produce a threefold stimulation of draining lymph node cell proliferation compared with concurrent controls (EC3 value) and that all reasonable validation requirements have been addressed successfully. EC3 measurements are reproducible in both intra- and interlaboratory evaluations and are stable over time. It has been shown also, by several independent groups, that EC3 values correlate closely with data on relative human skin sensitization potency. Consequently, the recommendation made here is that LLNA EC3 measurements should now be regarded as a validated method for the determination of the relative potency of skin sensitizing chemicals, a conclusion that has already been reached by a number of independent expert groups.

In vivo potency revisited - Keep the target in sight.

PubMed

Gabrielsson, Johan; Peletier, Lambertus A; Hjorth, Stephan

2018-04-01

Potency is a central parameter in pharmacological and biochemical sciences, as well as in drug discovery and development endeavors. It is however typically defined in terms only of ligand to target binding affinity also in in vivo experimentation, thus in a manner analogous to in in vitro studies. As in vivo potency is in fact a conglomerate of events involving ligand, target, and target-ligand complex processes, overlooking some of the fundamental differences between in vivo and in vitro may result in serious mispredictions of in vivo efficacious dose and exposure. The analysis presented in this paper compares potency measures derived from three model situations. Model A represents the closed in vitro system, defining target binding of a ligand when total target and ligand concentrations remain static and constant. Model B describes an open in vivo system with ligand input and clearance (Cl (L) ), adding in parallel to the turnover (k syn , k deg ) of the target. Model C further adds to the open in vivo system in Model B also the elimination of the target-ligand complex (k e(RL) ) via a first-order process. We formulate corresponding equations of the equilibrium (steady-state) relationships between target and ligand, and complex and ligand for each of the three model systems and graphically illustrate the resulting simulations. These equilibrium relationships demonstrate the relative impact of target and target-ligand complex turnover, and are easier to interpret than the more commonly used ligand-, target- and complex concentration-time courses. A new potency expression, labeled L 50 , is then derived. L 50 is the ligand concentration at half-maximal target and complex concentrations and is an amalgamation of target turnover, target-ligand binding and complex elimination parameters estimated from concentration-time data. L 50 is then compared to the dissociation constant K d (target-ligand binding affinity), the conventional Black & Leff potency estimate EC 50 , and the derived Michaelis-Menten parameter K m (target-ligand binding and complex removal) across a set of literature data. It is evident from a comparison between parameters derived from in vitro vs. in vivo experiments that L 50 can be either numerically greater or smaller than the K d (or K m ) parameter, primarily depending on the ratio of k deg -to-k e(RL) . Contrasting the limit values of target R and target-ligand complex RL for ligand concentrations approaching infinity demonstrates that the outcome of the three models differs to a great extent. Based on the analysis we propose that a better understanding of in vivo pharmacological potency requires simultaneous assessment of the impact of its underlying determinants in the open system setting. We propose that L 50 will be a useful parameter guiding predictions of the effective concentration range, for translational purposes, and assessment of in vivo target occupancy/suppression by ligand, since it also encompasses target turnover - in turn also subject to influence by pathophysiology and drug treatment. Different compounds may have similar binding affinity for a target in vitro (same K d ), but vastly different potencies in vivo. L 50 points to what parameters need to be taken into account, and particularly that closed-system (in vitro) parameters should not be first choice when ranking compounds in vivo (open system). Copyright © 2017 Elsevier Inc. All rights reserved.

Additivity of Pyrethroid Actions on Sodium Influx in Cerebrocortical Neurons in Primary Culture

PubMed Central

Cao, Zhengyu; Shafer, Timothy J.; Crofton, Kevin M.; Gennings, Chris

2011-01-01

Background: Pyrethroid insecticides bind to voltage-gated sodium channels and modify their gating kinetics, thereby disrupting neuronal function. Although previous work has tested the additivity of pyrethroids in vivo, this has not been assessed directly at the primary molecular target using a functional measure. Objectives: We investigated the potency and efficacy of 11 structurally diverse food-use pyrethroids to evoke sodium (Na+) influx in neurons and tested the hypothesis of dose additivity for a mixture of these same 11 compounds. Methods: We determined pyrethroid-induced increases in Na+ influx in primary cultures of cerebrocortical neurons using the Na+-sensitive dye sodium-binding benzofuran isophthalate (SBFI). Concentration-dependent responses for 11 pyrethroids were determined, and the response to dilutions of a mixture of all 11 compounds at an equimolar mixing ratio was assessed. Additivity was tested assuming a dose-additive model. Results: Seven pyrethroids produced concentration-dependent, tetrodotoxin-sensitive Na+ influx. The rank order of potency was deltamethrin > S-bioallethrin > β-cyfluthrin > λ-cyhalothrin > esfenvalerate > tefluthrin > fenpropathrin. Cypermethrin and bifenthrin produced modest increases in Na+ influx, whereas permethrin and resmethrin were inactive. When all 11 pyrethroids were present at an equimolar mixing ratio, their actions on Na+ influx were consistent with a dose-additive model. Conclusions: These data provide in vitro relative potency and efficacy measurements for 7 pyrethroid compounds in intact mammalian neurons. Despite differences in individual compound potencies, we found the action of a mixture of all 11 pyrethroids to be additive when we used an appropriate statistical model. These results are consistent with a previous report of the additivity of pyrethroids in vivo. PMID:21665567

Evaluation of Cannabinoid and Terpenoid Content: Cannabis Flower Compared to Supercritical CO2 Concentrate.

PubMed

Sexton, Michelle; Shelton, Kyle; Haley, Pam; West, Mike

2018-03-01

A recent cannabis use survey revealed that 60% of cannabis users rely on smelling the flower to select their cannabis. Olfactory indicators in plants include volatile compounds, principally represented by the terpenoid fraction. Currently, medicinal- and adult-use cannabis is marketed in the United States with relatively little differentiation between products other than by a common name, association with a species type, and Δ-9 tetrahydrocannabinol/cannabidiol potency. Because of this practice, how terpenoid compositions may change during an extraction process is widely overlooked. Here we report on a comparative study of terpenoid and cannabinoid potencies of flower and supercritical fluid CO 2 (SC-CO 2 ) extract from six cannabis chemovars grown in Washington State. To enable this comparison, we employed a validated high-performance liquid chromatography/diode array detector methodology for quantification of seven cannabinoids and developed an internal gas chromatography-mass spectrometry method for quantification of 42 terpenes. The relative potencies of terpenoids and cannabinoids in flower versus concentrate were significantly different. Cannabinoid potency increased by factors of 3.2 for Δ-9 tetrahydrocannabinol and 4.0 for cannabidiol in concentrates compared to flower. Monoterpenes were lost in the extraction process; a ketone increased by 2.2; an ether by 2.7; monoterpene alcohols by 5.3, 7 and 9.4; and sesquiterpenes by 5.1, 4.2, 7.7, and 8.9. Our results demonstrate that the product of SC-CO 2 extraction may have a significantly different chemotypic fingerprint from that of cannabis flower. These results highlight the need for more complete characterization of cannabis and associated products, beyond cannabinoid content, in order to further understand health-related consequences of inhaling or ingesting concentrated forms. Georg Thieme Verlag KG Stuttgart · New York.

Determination of influenza B identity and potency in quadrivalent inactivated influenza vaccines using lineage-specific monoclonal antibodies

PubMed Central

Verma, Swati; Soto, Jackeline; Vasudevan, Anupama; Schmeisser, Falko; Alvarado-Facundo, Esmeralda; Wang, Wei; Weiss, Carol D.

2017-01-01

Co-circulation of two antigenically and genetically distinct lineages of influenza B virus, represented by prototype viruses B/Victoria/2/1987 and B/Yamagata/16/1988, has led to the development of quadrivalent influenza vaccines that contain two influenza B antigens. The inclusion of two influenza B antigens presents challenges for the production and regulation of inactivated quadrivalent vaccines, including the potential for cross-reactivity of the reagents used in identity and potency assays because of the relative close relatedness of the hemagglutinin (HA) from the two virus lineages. Monoclonal antibodies (mAbs) specific for the two lineages of influenza B HA were generated and characterized and used to set-up simple identity tests that distinguish the influenza B antigens in inactivated trivalent and quadrivalent vaccines. The lineage-specific mAbs bound well to the HA of influenza B strains included in influenza vaccines over a period of more than 10 years, suggesting that identity tests using such lineage-specific mAbs would not necessarily have to be updated with every influenza B vaccine strain change. These lineage-specific mAbs were also used in an antibody capture ELISA format to quantify HA in vaccine samples, including monovalent, trivalent, and quadrivalent vaccine samples from various manufacturers. The results demonstrated correlation with HA values determined by the traditional single radial immunodiffusion (SRID) assay. Further, the antibody-capture ELISA was able to distinguish heat-stressed vaccine from unstressed vaccine, and was similar to the SRID in quantifying the resultant loss of potency. These mAb reagents should be useful for further development of antibody-based alternative influenza B identity and potency assays. PMID:28423025

Determination of influenza B identity and potency in quadrivalent inactivated influenza vaccines using lineage-specific monoclonal antibodies.

PubMed

Verma, Swati; Soto, Jackeline; Vasudevan, Anupama; Schmeisser, Falko; Alvarado-Facundo, Esmeralda; Wang, Wei; Weiss, Carol D; Weir, Jerry P

2017-01-01

Co-circulation of two antigenically and genetically distinct lineages of influenza B virus, represented by prototype viruses B/Victoria/2/1987 and B/Yamagata/16/1988, has led to the development of quadrivalent influenza vaccines that contain two influenza B antigens. The inclusion of two influenza B antigens presents challenges for the production and regulation of inactivated quadrivalent vaccines, including the potential for cross-reactivity of the reagents used in identity and potency assays because of the relative close relatedness of the hemagglutinin (HA) from the two virus lineages. Monoclonal antibodies (mAbs) specific for the two lineages of influenza B HA were generated and characterized and used to set-up simple identity tests that distinguish the influenza B antigens in inactivated trivalent and quadrivalent vaccines. The lineage-specific mAbs bound well to the HA of influenza B strains included in influenza vaccines over a period of more than 10 years, suggesting that identity tests using such lineage-specific mAbs would not necessarily have to be updated with every influenza B vaccine strain change. These lineage-specific mAbs were also used in an antibody capture ELISA format to quantify HA in vaccine samples, including monovalent, trivalent, and quadrivalent vaccine samples from various manufacturers. The results demonstrated correlation with HA values determined by the traditional single radial immunodiffusion (SRID) assay. Further, the antibody-capture ELISA was able to distinguish heat-stressed vaccine from unstressed vaccine, and was similar to the SRID in quantifying the resultant loss of potency. These mAb reagents should be useful for further development of antibody-based alternative influenza B identity and potency assays.

Reproducibility of the anti-Factor Xa and anti-Factor IIa assays applied to enoxaparin solution.

PubMed

Martinez, Céline; Savadogo, Adama; Agut, Christophe; Anger, Pascal

2013-01-01

Enoxaparin is a widely used subcutaneously administered antithrombotic agent comprising a complex mixture of glycosaminoglycan chains. Owing to this complexity, its antithrombotic potency cannot be defined by physicochemical methods and is therefore evaluated using an enzymatic assay of anti-Xa and anti-IIa activity. Maintaining consistent anti-Xa activity in the final medicinal product allows physicians to ensure administration of the appropriate dosage to their patients. Bioassays are usually complex and display poorer reproducibility than physicochemical tests such as HPLC assays. Here, we describe the implementation of a common robotic platform and standard release potency testing procedures for enoxaparin sodium injection (Lovenox, Sanofi, Paris, France) products at seven quality control sites within Sanofi. Qualification and analytical procedures, as well as data handling, were optimized and harmonized to improve assay reproducibility. An inter-laboratory study was performed in routine-release conditions. The coefficients of variation for repeatability and reproducibility in assessments of anti-Xa activity were 1.0% and 1.2%, respectively. The tolerance interval in reproducibility precision conditions, expressed as percentage potency, was 96.8-103.2% of the drug product target of 10,000 IU/ml, comparing favorably with the United States of America Pharmacopeia specification (90-110%). The maximum difference between assays in two different laboratories is expected to be 4.1%. The reproducibility characteristics of anti-IIa activity assessments were found to be similar. These results demonstrate the effectiveness of the standardization process established and allow for further improvements to quality control in Lovenox manufacture. This process guarantees closeness between actual and target potencies, as exemplified by the results of release assays obtained during a three-year period. Copyright © 2013 Elsevier B.V. All rights reserved.

Accessibility and potency of uterotonic drugs purchased by simulated clients in four districts in India.

PubMed

Stanton, Cynthia; Nand, Deepak Nitya; Koski, Alissa; Mirzabagi, Ellie; Brooke, Steve; Grady, Breanne; Mullany, Luke C

2014-11-13

Surveillance of drug quality for antibiotics, antiretrovirals, antimalarials and vaccines is better established than surveillance for maternal health drugs in low-income countries, particularly uterotonic drugs for the prevention and treatment of postpartum hemorrhage. The objectives of this study are to: assess private sector accessibility of four drugs used for uterotonic purposes (oxytocin, methylergometrine, misoprostol, valethamate bromide); and to assess potency of oxytocin and methylergometrine ampoules purchased by simulated clients. The study was conducted in Hassan and Bagalkot districts in Karnataka state and Agra and Gorakhpur districts in Uttar Pradesh state. A sample of 877 private pharmacies was selected (using a stratified, systematic sampling with random start), among which 847 were successfully visited. The target sample size for assessment of accessibility was 50 pharmacies per drug, per district. The target sample size for potency assessment was 100 purchases each of oxytocin and methylergometrine across all districts. Successful drug purchases varied by state. In Agra and Gorakhpur, 90%-100% of visits for each of the drugs resulted in a purchase. In Bagalkot and Hassan, only 29%-52% of visits for each drug resulted in a purchase. Regarding potency, the percent of active pharmaceutical ingredient was assessed using United States Pharmacopeia monograph #33 for both drugs; 193 and 188 ampoules of oxytocin and methylergometrine, respectively, were assessed. The percent of oxytocin ampoules outside manufacturer specification ranged from 33%-40% in Karnataka and from 22%-50% in Uttar Pradesh. In Bagalkot and Hassan, 96% and 100% of the methylergometrine ampoules were outside manufacturer specification, respectively. In Agra and Gorakhpur, 54% and 44% were outside manufacturer specification, respectively. Private sector accessibility of uterotonic drugs in study districts in Karnataka warrants attention. Most importantly, interventions to assure quality oxytocin and particularly methylergometrine are needed in study districts in both states.

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (3)--One- and three-month repeated oral dose toxicity studies in rats].

PubMed

Kato, I; Sato, K; Ueno, M; Inoue, S; Harihara, A; Moriyama, T; Nishimura, K; Yabuuchi, K; Hirata, M; Muraoka, Y; Kitamura, T; Furukawa, H

2001-05-01

One- or three-month repeated oral dose toxicity studies of Cefmatilen hydrochloride hydrate (S-1090) in rats were conducted. Doses were set at 80, 200, 500 and 1250 mg potency/kg/day in the one-month toxicity study, and 100, 300 and 1000 mg potency/kg/day in the three-month toxicity study. Body weights increased favorably and no deaths occurred in all treated groups of both studies. The changes observed in both studies were soft feces, abdominal distention, increased food and water consumption, decreases of urine volume and pH, and a decrease of blood neutrophils in almost all treated groups, reddish-brown feces (due to chelated products of S-1090 and its decomposition products with Fe3+ in the diet) in groups dosed at 300 mg potency/kg or more, and a lower mature granulocyte ratio in the bone marrow in groups dosed at 1000 mg potency/kg or more. In necropsy, cecal enlargement with a large amount of muddy content was observed in all treated groups of both studies. In the three-month toxicity study, elevated drug-metabolizing enzyme activities were noted in the liver of the males in the 1000 mg potency/kg group. These changes were slight except for the cecal enlargement and the rats recovered well with drug withdrawal. Since no toxicologically significant changes were noted in either study, the NOAEL of S-1090 was estimated to be 1250 mg potency/kg/day in the one-month toxicity study and 1000 mg potency/kg/day in the three-month toxicity study.

Activation of peripheral blood mononuclear cells by dengue virus infection depotentiates balapiravir.

PubMed

Chen, Yen-Liang; Abdul Ghafar, Nahdiyah; Karuna, Ratna; Fu, Yilong; Lim, Siew Pheng; Schul, Wouter; Gu, Feng; Herve, Maxime; Yokohama, Fumiaki; Wang, Gang; Cerny, Daniela; Fink, Katja; Blasco, Francesca; Shi, Pei-Yong

2014-02-01

In a recent clinical trial, balapiravir, a prodrug of a cytidine analog (R1479), failed to achieve efficacy (reducing viremia after treatment) in dengue patients, although the plasma trough concentration of R1479 remained above the 50% effective concentration (EC(50)). Here, we report experimental evidence to explain the discrepancy between the in vitro and in vivo results and its implication for drug development. R1479 lost its potency by 125-fold when balapiravir was used to treat primary human peripheral blood mononuclear cells (PBMCs; one of the major cells targeted for viral replication) that were preinfected with dengue virus. The elevated EC(50) was greater than the plasma trough concentration of R1479 observed in dengue patients treated with balapiravir and could possibly explain the efficacy failure. Mechanistically, dengue virus infection triggered PBMCs to generate cytokines, which decreased their efficiency of conversion of R1479 to its triphosphate form (the active antiviral ingredient), resulting in decreased antiviral potency. In contrast to the cytidine-based compound R1479, the potency of an adenosine-based inhibitor of dengue virus (NITD008) was much less affected. Taken together, our results demonstrate that viral infection in patients before treatment could significantly affect the conversion of the prodrug to its active form; such an effect should be calculated when estimating the dose efficacious for humans.

Plasma metabolomic profiles of breast cancer patients after short-term limonene intervention.

PubMed

Miller, Jessica A; Pappan, Kirk; Thompson, Patricia A; Want, Elizabeth J; Siskos, Alexandros P; Keun, Hector C; Wulff, Jacob; Hu, Chengcheng; Lang, Julie E; Chow, H-H Sherry

2015-01-01

Limonene is a lipophilic monoterpene found in high levels in citrus peel. Limonene demonstrates anticancer properties in preclinical models with effects on multiple cellular targets at varying potency. While of interest as a cancer chemopreventive, the biologic activity of limonene in humans is poorly understood. We conducted metabolite profiling in 39 paired (pre/postintervention) plasma samples from early-stage breast cancer patients receiving limonene treatment (2 g QD) before surgical resection of their tumor. Metabolite profiling was conducted using ultra-performance liquid chromatography coupled to a linear trap quadrupole system and gas chromatography-mass spectrometry. Metabolites were identified by comparison of ion features in samples to a standard reference library. Pathway-based interpretation was conducted using the human metabolome database and the MetaCyc database. Of the 397 named metabolites identified, 72 changed significantly with limonene intervention. Class-based changes included significant decreases in adrenal steroids (P < 0.01), and significant increases in bile acids (P ≤ 0.05) and multiple collagen breakdown products (P < 0.001). The pattern of changes also suggested alterations in glucose metabolism. There were 47 metabolites whose change with intervention was significantly correlated to a decrease in cyclin D1, a cell-cycle regulatory protein, in patient tumor tissues (P ≤ 0.05). Here, oral administration of limonene resulted in significant changes in several metabolic pathways. Furthermore, pathway-based changes were related to the change in tissue level cyclin D1 expression. Future controlled clinical trials with limonene are necessary to determine the potential role and mechanisms of limonene in the breast cancer prevention setting. ©2014 American Association for Cancer Research.

Structure-Based Predictions of Activity Cliffs

PubMed Central

Husby, Jarmila; Bottegoni, Giovanni; Kufareva, Irina; Abagyan, Ruben; Cavalli, Andrea

2015-01-01

In drug discovery, it is generally accepted that neighboring molecules in a given descriptors' space display similar activities. However, even in regions that provide strong predictability, structurally similar molecules can occasionally display large differences in potency. In QSAR jargon, these discontinuities in the activity landscape are known as ‘activity cliffs’. In this study, we assessed the reliability of ligand docking and virtual ligand screening schemes in predicting activity cliffs. We performed our calculations on a diverse, independently collected database of cliff-forming co-crystals. Starting from ideal situations, which allowed us to establish our baseline, we progressively moved toward simulating more realistic scenarios. Ensemble- and template-docking achieved a significant level of accuracy, suggesting that, despite the well-known limitations of empirical scoring schemes, activity cliffs can be accurately predicted by advanced structure-based methods. PMID:25918827

The potency of electrical energy production from urine by microbial fuel cell using boron-doped diamond electrode

NASA Astrophysics Data System (ADS)

Rahmawati, I.; Ivandini, T. A.; Saepudin, E.

2017-04-01

Microbial fuel cell was developed since it is one of the prospective alternative energy and eco-friendly, using urine as the fuel and Candida fukuyamaensis as a biocatalyst. Boron-doped diamond was used as the electrode. At pH 7, maximum power and current densities of 109.6 mW/m2 and 970 mA/m2 can be obtained, respectively. The results indicated the potency of the system to produce an alternative energy. Furthermore, glucose and creatinine in urine are proposed to be responsible as the carbon sources for the metabolism of C. fukuyamaensis.

Isosteric replacements of the carboxylic acid of drug candidate VX-787: Effect of charge on antiviral potency and kinase activity of azaindole-based influenza PB2 inhibitors.

PubMed

Boyd, Michael J; Bandarage, Upul K; Bennett, Hamilton; Byrn, Randal R; Davies, Ioana; Gu, Wenxin; Jacobs, Marc; Ledeboer, Mark W; Ledford, Brian; Leeman, Joshua R; Perola, Emanuele; Wang, Tiansheng; Bennani, Youssef; Clark, Michael P; Charifson, Paul S

2015-05-01

VX-787 is a first in class, orally bioavailable compound that offers unparalleled potential for the treatment of pandemic and seasonal influenza. As a part of our routine SAR exploration, carboxylic acid isosteres of VX-787 were prepared and tested against influenza A. It was found that the negative charge is important for maintaining potency and selectivity relative to kinase targets. Neutral carboxylic acid replacements generally resulted in compounds that were significantly less potent and less selective relative to the charged species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quality Assessment of Compounded 17-hydroxyprogesterone Caproate

PubMed Central

Chang, Justine; Zhao, Yang; Zhao, WenChen; Venkataramanan, Raman; Caritis, Steve N.

2013-01-01

Objective To evaluate the quality of compounded 17-hydroxyprogesterone caproate (17-OHPC) Study Design Compounded 17-OHPC was obtained from 15 compounding pharmacies throughout the U.S. and analyzed for potency, impurities, sterility, and pyrogen status. Results Eighteen samples were supplied by 15 compounding pharmacies. The concentration of 17-OHPC in all samples was within the specification limits and all tested samples passed sterility and pyrogen testing. Only 1 of 18 samples was out of specification limits for impurities. Conclusion Compounded 17-OHPC obtained from 15 pharmacies throughout the U.S. did not raise safety concerns when assessed for potency, sterility, pyrogen status or impurities. PMID:24200163

Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains

PubMed Central

Westdijk, Janny; Koedam, Patrick; Barro, Mario; Steil, Benjamin P.; Collin, Nicolas; Vedvick, Thomas S.; Bakker, Wilfried A.M.; van der Ley, Peter; Kersten, Gideon

2013-01-01

Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titers (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotype 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7- 20- 27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants. PMID:23313617

Pharmacological evaluation of a novel series of urea, thiourea and guanidine derivatives as P2X7 receptor antagonists.

PubMed

Wong, Erick C N; Reekie, Tristan A; Werry, Eryn L; O'Brien-Brown, James; Bowyer, Sarah L; Kassiou, Michael

2017-06-01

We report on P2X 7 receptor antagonists based on a lead adamantly-cyanoguanidine-aryl moiety. We have investigated the importance of the central cyanoguanidine moiety by replacing it with urea, thiourea or guanidine moieties. We have also investigated the linker length between the central moiety and the aryl portion. All compounds were assessed for their inhibitory potency in a pore-formation dye uptake assay at the P2X 7 receptor. None of the compounds resulted in an improved potency illustrating the importance of the cyanoguanidine moiety in this chemotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

Allergenicity evaluation of fragrance mix and its ingredients by using ex vivo local lymph node assay-BrdU endpoints.

PubMed

Ulker, Ozge Cemiloglu; Kaymak, Yesim; Karakaya, Asuman

2014-03-01

The present studies were performed to compare the differences between sensitization potency of fragrance mix and its ingredients (oak moss absolute, isoeugenol, eugenol, cinnamal, hydroxycitronellal, geraniol, cinnamic alcohol, alpha amyl cinnamal), by using ex vivo LLNA-BrdU ELISA. The SI and EC3 values were calculated and potency classification was found for the mixture and for each ingredients. TH1 cytokines (IL-2, IFN-γ) and TH2 cytokines (IL-4, IL-5) releases from lymph node cell culture were also investigated as contact sensitization endpoints. The EC3 values were calculated and the potency of contact sensitization were classified for fragrance mix, oak moss absolute, isoeugenol, eugenol, cinnamal, hydroxycitronellal, geraniol, cinnamic alcohol, alpha amyl cinnamal respectively: 4.4% (moderate), 3.4% (moderate), 0.88% (strong), 16.6% (weak), 1.91% (moderate), 9.77% (moderate), 13.1% (weak), 17.93% (weak), 7.74% (moderate). According to our results it should be concluded that exposure to fragrance mix does not constitute an evidently increased hazard compared to exposure to each of the eight fragrance ingredients separately. Cytokine analyses results indicate that both TH1 and TH2 cytokines are involved in the regulation of murine contact allergy and can be considered as useful endpoints. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative stability of repackaged metoprolol tartrate tablets.

PubMed

Yang, Yongsheng; Gupta, Abhay; Carlin, Alan S; Faustino, Patrick J; Lyon, Robbe C; Ellison, Christopher D; Rothman, Barry; Khan, Mansoor A

2010-01-29

The stability of metoprolol tartrate tablets packaged in original high density polyethylene containers and repackaged in USP Class A unit-dose blister packs was investigated. Studies were conducted at 25 degrees C/60% relative humidity (RH) for 52 weeks and at 40 degrees C/75% RH for 13 weeks. The potency, dissolution, water content, loss on drying and hardness of the drug products were analyzed. Results indicated no differences in the stability between the tablets in both packages stored under 25 degrees C/60% RH. No difference in potency was found in both packages under either condition. However, a significant weight increase due to moisture uptake was observed for the repackaged tablets stored under 40 degrees C/75% RH. The weight increase was accompanied by a decrease in tablet hardness (6.5-0 kp) and a increase in dissolution rate (51-92%) in 5 min. Near-infrared (NIR) chemical imaging also monitored moisture uptake of the tablet non-invasively through the package. The observed changes in product stability may adversely affect the products bioavailability profile, even though the potency of the active drug remained within USP specification range of 90-110%. Study results suggest product quality can be negatively impacted even when using USP Class A repackaging materials. Published by Elsevier B.V.

Quantitative structure - mesothelioma potency model ...

EPA Pesticide Factsheets

Cancer potencies of mineral and synthetic elongated particle (EP) mixtures, including asbestos fibers, are influenced by changes in fiber dose composition, bioavailability, and biodurability in combination with relevant cytotoxic dose-response relationships. A unique and comprehensive rat intra-pleural (IP) dose characterization data set with a wide variety of EP size, shape, crystallographic, chemical, and bio-durability properties facilitated extensive statistical analyses of 50 rat IP exposure test results for evaluation of alternative dose pleural mesothelioma response models. Utilizing logistic regression, maximum likelihood evaluations of thousands of alternative dose metrics based on hundreds of individual EP dimensional variations within each test sample, four major findings emerged: (1) data for simulations of short-term EP dose changes in vivo (mild acid leaching) provide superior predictions of tumor incidence compared to non-acid leached data; (2) sum of the EP surface areas (ÓSA) from these mildly acid-leached samples provides the optimum holistic dose response model; (3) progressive removal of dose associated with very short and/or thin EPs significantly degrades resultant ÓEP or ÓSA dose-based predictive model fits, as judged by Akaike’s Information Criterion (AIC); and (4) alternative, biologically plausible model adjustments provide evidence for reduced potency of EPs with length/width (aspect) ratios 80 µm. Regar

BoNT/AB hybrid maintains similar duration of paresis as BoNT/A wild-type in murine running wheel assay.

PubMed

Kutschenko, Anna; Reinert, Marie-Christine; Krez, Nadja; Liebetanz, David; Rummel, Andreas

2017-03-01

The highly potent Botulinum neurotoxins (BoNT) are successful drugs to treat neuromuscular disorders. Efforts are being made to further reduce the injected BoNT dose and to lengthen the interval between treatments. Detailed knowledge of the BoNT structure-activity relationship (SAR) allows combining the best features of the different BoNT serotypes. Of all seven BoNT serotypes A-G, BoNT/A displays the highest potency despite low neuronal binding affinity, while BoNT/B exhibits much higher affinity. Recently, a new BoNT/AB hybrid (AABB) was constructed comprising the catalytic and translocation domain of BoNT/A and the 50kDa cell binding domain of BoNT/B. Here, we compared BoNT/A wild-type (AAAA) and AABB with regard to ex vivo potency and in vivo potency, efficacy and duration of action using the mouse phrenic nerve hemidiaphragm assay and the murine running wheel assay, respectively. The ex vivo potency of AABB was found to be 8.4-fold higher than that of AAAA. For the latter, two and 5 pg each of AAAA and AABB, respectively, were bilaterally injected into the calf muscles and mouse running wheel performance was automatically monitored during the following weeks to determine potency, efficacy and duration. Mice displayed a dose-dependent impairment of running performance. AABB showed potency, efficacy and duration equal to AAAA demonstrating successful exchange of the cell binding domain. AABB might combine the higher potency and longer duration of BoNT/A with the target specificity for the autonomic nervous system of BoNT/B. AABB might therefore constitute an improved treatment option for acetylcholine-mediated autonomic disorders such as hypersalivation or hyperhidrosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Cannabinoid receptor-dependent and -independent anti-proliferative effects of omega-3 ethanolamides in androgen receptor-positive and -negative prostate cancer cell lines

PubMed Central

Brown, Iain; Cascio, Maria G.; Wahle, Klaus W.J.; Smoum, Reem; Mechoulam, Raphael; Ross, Ruth A.; Pertwee, Roger G.; Heys, Steven D.

2010-01-01

The omega-3 fatty acid ethanolamides, docosahexaenoyl ethanolamide (DHEA) and eicosapentaenoyl ethanolamide (EPEA), displayed greater anti-proliferative potency than their parent omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in LNCaP and PC3 prostate cancer cells. DHEA and EPEA activated cannabinoid CB1 and CB2 receptors in vitro with significant potency, suggesting that they are endocannabinoids. Both LNCaP and PC3 cells expressed CB1 and CB2 receptors, and the CB1- and CB2-selective antagonists, AM281 and AM630, administered separately or together, reduced the anti-proliferative potencies of EPEA and EPA but not of DHEA or DHA in PC3 cells and of EPA but not of EPEA, DHEA or DHA in LNCaP cells. Even so, EPEA and EPA may not have inhibited PC3 or LNCaP cell proliferation via cannabinoid receptors since the anti-proliferative potency of EPEA was well below the potency it displayed as a CB1 or CB2 receptor agonist. Indeed, these receptors may mediate a protective effect because the anti-proliferative potency of DHEA in LNCaP and PC3 cells was increased by separate or combined administration of AM281 and AM630. The anandamide-metabolizing enzyme, fatty acid amide hydrolase (FAAH), was highly expressed in LNCaP but not PC3 cells. Evidence was obtained that FAAH metabolizes EPEA and DHEA and that the anti-proliferative potencies of these ethanolamides in LNCaP cells can be enhanced by inhibiting this enzyme. Our findings suggest that the expression of cannabinoid receptors and of FAAH in some tumour cells could well influence the effectiveness of DHA and EPA or their ethanolamide derivatives as anticancer agents. PMID:20660502

Topical corticosteroids in the treatment of acute sunburn: a randomized, double-blind clinical trial.

PubMed

Faurschou, Annesofie; Wulf, Hans C

2008-05-01

To examine the effect of topical corticosteroid treatment on acute sunburn. Randomized, double-blind clinical trial. University dermatology department. Twenty healthy volunteers with Fitzpatrick skin types I (highly sensitive, always burns easily, tans minimally) through III (sun-sensitive skin, sometimes burns, slowly tans to light brown). Seven 34-cm(2) areas were marked on the upper aspect of the back of each participant. An untreated area was tested to determine UV sensitivity. Two areas were treated with excess amounts (2 mg/cm(2)) of either a moderate-potency corticosteroid or a high-potency corticosteroid 30 minutes before UV-B exposure as controls. Six or 23 hours after exposure to radiation, the remaining areas were treated with the 2 corticosteroid preparations. The sunburn improvement factor (SIF) was determined by the following equation: SIF = MED (minimal erythema dose) on treated skin/MED on nontreated skin. An SIF greater than 1 indicated an effect of topical corticosteroids in sunburn relief. The SIFs in the areas treated with either topical corticosteroid 30 minutes before UV-B exposure or high-potency corticosteroid 6 hours after UV-B exposure were significantly different from SIFs in areas that received no treatment (SIF 1.1-1.7; P < .05). Only the median SIF of 1.7 in the areas treated with high-potency corticosteroid 30 minutes before UV-B exposure was clinically relevant. The areas treated 23 hours after UV-B exposure and the areas treated with a moderate-potency corticosteroid 6 hours after UV-B exposure showed no significant reduction in redness. Treatment with topical moderate-potency or high-potency corticosteroids does not provide a clinically useful decrease in the acute sunburn reaction when applied 6 or 23 hours after UV exposure.

Potency assay design for adjuvanted recombinant proteins as malaria vaccines.

PubMed

Giersing, Birgitte K; Dubovsky, Filip; Saul, Allan; Denamur, Francoise; Minor, Philip; Meade, Bruce

2006-05-15

Many licensed vaccines are composed of live, attenuated or inactivated whole-cell microorganisms, or they comprise purified components from whole-cell extracts or culture supernatants. For some diseases, pathology is fairly well understood, and there may be known correlates of protection that provide obvious parameters for assessment of vaccine potency. However, this is not always the case, and some effective vaccines are routinely used even though the mechanisms or correlates of protection are unknown. Some more modern vaccine approaches employ purified recombinant proteins, based on molecules that appear on the surface of the pathogen. This is one of the strategies that has been adopted in the quest to develop a malaria vaccine. Use of these parasite antigens as vaccine candidates is supported by substantial epidemiological data, and some have demonstrated the ability to elicit protective responses in animal models of malaria infection. However, there is as yet no immunological correlate of protection and no functional assays or animal models that have demonstrated the ability to predict efficacy in humans. There is little precedence for the most appropriate and practical method for assessing potency of vaccines based on these recombinant molecules for malaria vaccines. This is likely because the majority of malaria vaccine candidates have only recently entered clinical evaluation. The PATH Malaria Vaccine Initiative (MVI) convened a panel with expertise in potency assay design from industry, governmental institutions, and regulatory bodies to discuss and review the rationale, available methods, and best approaches for assessing the potency of recombinant proteins, specifically for their use as malarial vaccines. The aim of this meeting was to produce a discussion document on the practical potency assessment of recombinant protein malaria vaccines, focusing on early phase potency assay development.

Development of a serology-based assay for efficacy evaluation of a lactococcicosis vaccine in Seriola fish.

PubMed

Nakajima, Nao; Kawanishi, Michiko; Imamura, Saiki; Hirano, Fumiya; Uchiyama, Mariko; Yamamoto, Kinya; Nagai, Hidetaka; Futami, Kunihiko; Katagiri, Takayuki; Maita, Masashi; Kijima, Mayumi

2014-05-01

Lactococcicosis is an infection caused by the bacterium Lactococcus garvieae and creates serious economic damage to cultured marine and fresh water fish industries. The use of the assay currently applied to evaluate the potency of the lactococcicosis vaccine is contingent upon meeting specific parameters after statistical analysis of the percent survival of the vaccinated yellowtail or greater amberjack fish after challenge with a virulent strain of L. garvieae. We found that measuring the serological response with a quantitative agglutinating antibody against the L. garvieae antigen (phenotype KG+) was an effective method of monitoring the potency of lactococcicosis vaccines. Vaccinated fish had significantly higher antibody titers than control fish when the L. garvieae Lg2-S strain was used as an antigen. Furthermore, the titer of the KG + agglutinating antibody was correlated with vaccine potency, and the cut-off titer was determined by comparing the data with those from the challenge test. An advantage of the proposed serology-based potency assay is that it will contribute to reduced numbers of animal deaths during vaccine potency evaluations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Skin sensitization potency of isoeugenol and its dimers evaluated by a non-radioisotopic modification of the local lymph node assay and guinea pig maximization test.

PubMed

Takeyoshi, Masahiro; Iida, Kenji; Suzuki, Keiko; Yamazaki, Shunsuke

2008-05-01

Allergic contact dermatitis is the serious unwanted effect arising from the use of consumer products such as cosmetics. Isoeugenol is a fragrance chemical with spicy, carnation-like scent, is used in many kinds of cosmetics and is a well-known moderate human sensitizer. It was previously reported that the dimerization of eugenol yielded two types of dimer possessing different sensitization potencies. This study reports the differences in skin sensitization potencies for isoeugenol and two types of dimer, beta-O-4-dilignol and dehydrodiisoeugenol (DIEG), as evaluated by the non-radioisotopic local lymph node assay (non-RI LLNA) and guinea pig maximization test. In the guinea pig maximization test, isoeugenol, beta-O-4-dilignol and DIEG were classified as extreme, weak and moderate sensitizers, respectively. As for the results of non-RI LLNA, the EC3 for isoeugenol, beta-O-4-dilignol and DIEG were calculated as 12.7%, >30% and 9.4%, respectively. The two types of isoeugenol dimer showed different sensitizing activities similar to the case for eugenol dimers. A reduction of sensitization potency achieved by dimerization may lead to developing safer cosmetic ingredients. Isoeugenol dimers are not currently used for fragrance chemicals. However, the dimerization of isoeugenol may yield a promising candidate as a cosmetic ingredient with low sensitization risk. The data may also provide useful information for the structure-activity relationship (SAR) in skin sensitization. Copyright (c) 2007 John Wiley & Sons, Ltd.

Thyroid hormone disrupting activities associated with phthalate esters in water sources from Yangtze River Delta.

PubMed

Shi, Wei; Zhang, Feng-Xian; Hu, Guan-Jiu; Hao, Ying-Qun; Zhang, Xiao-Wei; Liu, Hong-Ling; Wei, Si; Wang, Xin-Ru; Giesy, John P; Yu, Hong-Xia

2012-07-01

Thyroid hormone disrupting compounds in water sources is a concern. Thyroid hormone (TH) agonist and antagonist activities of water sources from the Yangtze River, Huaihe River, Taihu Lake and ground water in the Yangtze River Delta region were evaluated by use of a TH reporter gene assay based on the green monkey kidney fibroblast (CV-1). While weak TH receptor (TR) agonist potency was observed in only one of 15 water sources, antagonist potency was present in most of the water sources. TR antagonist equivalents could be explained by the presence of dibutyl phthalate (DBP), with concentrations ranging from 2.8×10(1) to 1.6×10(3) μg DBP /L (ATR-EQ(50)s). None of the ground waters exhibited TH agonist potencies while all of the samples from Taihu Lake displayed notable TR antagonist potencies. To identify the responsible thyroid active compounds, instrumental analysis was conducted to measure a list of potential thyroid-disrupting chemicals, including organochlorine (OC) pesticides and phthalate esters. Combining the results of the instrumental analysis with those of the bioassay, DBP was determined to account for 17% to 144% of ATR-EQ(50)s in water sources. Furthermore, ATR-EQ(20-80) ranges for TR antagonist activities indicated that samples from locations WX-1 and WX-2 posed the greatest health concern and the associated uncertainty may warrant further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Changes in Cannabis Potency Over the Last 2 Decades (1995-2014): Analysis of Current Data in the United States.

PubMed

ElSohly, Mahmoud A; Mehmedic, Zlatko; Foster, Susan; Gon, Chandrani; Chandra, Suman; Church, James C

2016-04-01

Marijuana is the most widely used illicit drug in the United States and all over the world. Reports indicate that the potency of cannabis preparation has been increasing. This report examines the concentration of cannabinoids in illicit cannabis products seized by the U.S. Drug Enforcement Administration over the last 2 decades, with particular emphasis on Δ(9)-tetrahydrocannabinol and cannabidiol. Samples in this report were received over time from materials confiscated by the Drug Enforcement Administration and processed for analysis using a validated gas chromatography with flame ionization detector method. Between January 1, 1995, and December 31, 2014, 38,681 samples of cannabis preparations were received and analyzed. The data showed that although the number of marijuana samples seized over the last 4 years has declined, the number of sinsemilla samples has increased. Overall, the potency of illicit cannabis plant material has consistently increased over time since 1995 from ~4% in 1995 to ~12% in 2014. The cannabidiol content has decreased on average from ~.28% in 2001 to <.15% in 2014, resulting in a change in the ratio of Δ(9)-tetrahydrocannabinol to cannabidiol from 14 times in 1995 to ~80 times in 2014. There is a shift in the production of illicit cannabis plant material from regular marijuana to sinsemilla. This increase in potency poses higher risk of cannabis use, particularly among adolescents. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Emamectin is a non-selective allosteric activator of nicotinic acetylcholine receptors and GABAA/C receptors

PubMed Central

Xu, Xiaojun; Sepich, Caraline; Lukas, Ronald J; Zhu, Guonian; Chang, Yongchang

2016-01-01

Avermectins are a group of compounds isolated from a soil-dwelling bacterium. They have been widely used as parasiticides and insecticides, acting by relatively irreversible activation of invertebrate chloride channels. Emamectin is a soluble derivative of an avermectin. It is an insecticide, which persistently activates glutamate-gated chloride channels. However, its effects on mammalian ligand-gated ion channels are unknown. To this end, we tested the effect of emamectin on two cation selective nicotinic receptors and two GABA-gated chloride channels expressed in Xenopus oocytes using two-electrode voltage clamp. Our results demonstrate that emamectin could directly activate α7 nAChR, α4β2 nAChR, α1β2γ2 GABAA receptor and ρ1 GABAC receptor concentration dependently, with similar potencies for each channel. However, the potencies for it to activate these channels were at least two orders of magnitude lower than its potency of activating invertebrate glutamate-gated chloride channel. In contrast, ivermectin only activated the α1β2γ2 GABAA receptor. PMID:27049309

Multidrug Efflux Transporters Limit Accumulation of Inorganic, but Not Organic, Mercury in Sea Urchin Embryos

PubMed Central

Bošnjak, Ivana; Uhlinger, Kevin R.; Heim, Wesley; Smital, Tvrtko; Franekić-Čolić, Jasna; Coale, Kenneth; Epel, David; Hamdoun, Amro

2011-01-01

Mercuric compounds are persistent global pollutants that accumulate in marine organisms and in humans who consume them. While the chemical cycles and speciation of mercury in the oceans are relatively well described, the cellular mechanisms that govern which forms of mercury accumulate in cells and why they persist are less understood. In this study we examined the role of multidrug efflux transport in the differential accumulation of inorganic (HgCl2) and organic (CH3HgCl) mercury in sea urchin (Strongylocentrotus purpuratus) embryos. We found that inhibition of MRP/ABCC-type transporters increases intracellular accumulation of inorganic mercury but had no effect on accumulation of organic mercury. Similarly, pharmacological inhibition of metal conjugating enzymes by ligands GST/GSH significantly increases this antimitotic potency of inorganic mercury, but had no effect on the potency of organic mercury. Our results point to MRP-mediated elimination of inorganic mercury conjugates as a cellular basis for differences in the accumulation and potency of the two major forms of mercury found in marine environments. PMID:19924972

From fibroblasts and stem cells: implications for cell therapies and somatic cloning.

PubMed

Kues, Wilfried A; Carnwath, Joseph W; Niemann, Heiner

2005-01-01

Pluripotent embryonic stem cells (ESCs) from the inner cell mass of early murine and human embryos exhibit extensive self-renewal in culture and maintain their ability to differentiate into all cell lineages. These features make ESCs a suitable candidate for cell-replacement therapy. However, the use of early embryos has provoked considerable public debate based on ethical considerations. From this standpoint, stem cells derived from adult tissues are a more easily accepted alternative. Recent results suggest that adult stem cells have a broader range of potency than imagined initially. Although some claims have been called into question by the discovery that fusion between the stem cells and differentiated cells can occur spontaneously, in other cases somatic stem cells have been induced to commit to various lineages by the extra- or intracellular environment. Recent data from our laboratory suggest that changes in culture conditions can expand a subpopulation of cells with a pluripotent phenotype from primary fibroblast cultures. The present paper critically reviews recent data on the potency of somatic stem cells, methods to modify the potency of somatic cells and implications for cell-based therapies.

Emamectin is a non-selective allosteric activator of nicotinic acetylcholine receptors and GABAA/C receptors.

PubMed

Xu, Xiaojun; Sepich, Caraline; Lukas, Ronald J; Zhu, Guonian; Chang, Yongchang

2016-05-13

Avermectins are a group of compounds isolated from a soil-dwelling bacterium. They have been widely used as parasiticides and insecticides, acting by relatively irreversible activation of invertebrate chloride channels. Emamectin is a soluble derivative of an avermectin. It is an insecticide, which persistently activates glutamate-gated chloride channels. However, its effects on mammalian ligand-gated ion channels are unknown. To this end, we tested the effect of emamectin on two cation selective nicotinic receptors and two GABA-gated chloride channels expressed in Xenopus oocytes using two-electrode voltage clamp. Our results demonstrate that emamectin could directly activate α7 nAChR, α4β2 nAChR, α1β2γ2 GABAA receptor and ρ1 GABAC receptor concentration dependently, with similar potencies for each channel. However, the potencies for it to activate these channels were at least two orders of magnitude lower than its potency of activating invertebrate glutamate-gated chloride channel. In contrast, ivermectin only activated the α1β2γ2 GABAA receptor. Copyright © 2016 Elsevier Inc. All rights reserved.

Discovery, synthesis, and structure-activity relationships of 20(S)-protopanaxadiol (PPD) derivatives as a novel class of AMPKα2β1γ1 activators.

PubMed

Liu, Junhua; Chen, Dakai; Liu, Peng; He, Mengna; Li, Jia; Li, Jingya; Hu, Lihong

2014-05-22

Adenosine 5'-monophosphate-activated protein kinase (AMPK) has been demonstrated as a promising drug target due to its regulatory function in glucose and lipid metabolism. 20(S)-protopanoxadiol (PPD) was firstly identified from high throughput screening as a small molecule activator of AMPK subtype α2β1γ1. In order to enhance its potency on AMPK, a series of PPD derivatives were synthesized and evaluated. Structure-activity relationship study showed that the amine derivatives at the 24-position (groups I-VI) can improve the potency (EC50: 0.7-2.3 μM) and efficacy (fold: 2.5-3.8). Among them, compounds 12 and 13 exhibited the best potency (EC50: 1.2 and 0.7 μM) and efficacy (fold: 3.7 and 3.8). Further study suggested the mechanism of AMPK activation may functioned at the allosteric position, resulting the inhibition of the lipid synthesis in HepG2 cell model. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Conditions that Stabilize Membrane Domains Also Antagonize n-Alcohol Anesthesia

NASA Astrophysics Data System (ADS)

Machta, Benjamin B.; Gray, Ellyn; Nouri, Mariam; McCarthy, Nicola L. C.; Gray, Erin M.; Miller, Ann L.; Brooks, Nicholas J.; Veatch, Sarah L.

2016-08-01

Diverse molecules induce general anesthesia with potency strongly correlated both with their hydrophobicity and their effects on certain ion channels. We recently observed that several n-alcohol anesthetics inhibit heterogeneity in plasma membrane derived vesicles by lowering the critical temperature ($T_c$) for phase separation. Here we exploit conditions that stabilize membrane heterogeneity to further test the correlation between the anesthetic potency of n-alcohols and effects on $T_c$. First we show that hexadecanol acts oppositely to n-alcohol anesthetics on membrane mixing and antagonizes ethanol induced anesthesia in a tadpole behavioral assay. Second, we show that two previously described `intoxication reversers' raise $T_c$ and counter ethanol's effects in vesicles, mimicking the findings of previous electrophysiological and behavioral measurements. Third, we find that hydrostatic pressure, long known to reverse anesthesia, also raises $T_c$ in vesicles with a magnitude that counters the effect of butanol at relevant concentrations and pressures. Taken together, these results demonstrate that $\\Delta T_c$ predicts anesthetic potency for n-alcohols better than hydrophobicity in a range of contexts, supporting a mechanistic role for membrane heterogeneity in general anesthesia.

Work-group characteristics and performance in collectivistic and individualistic cultures.

PubMed

Sosik, John J; Jung, Dong I

2002-02-01

The authors conducted a cross-cultural longitudinal investigation of the effects of culture (individualism-collectivism dichotomy) on group characteristics (functional heterogeneity, preference for teamwork, group potency, outcome expectation) and on performance of 83 work groups performing 2 decision-making tasks over a 15-week period. The individualists (U.S. students) reported higher levels of functional heterogeneity and group potency and attained higher levels of group performance than did the collectivists (Korean students). In addition, culture and time interacted to influence ratings of group potency and outcome expectation. The difference in ratings of group potency between individualists and collectivists increased over time. Outcome expectation was greater among the collectivists in Time 1 and among the individualists in Time 2. The authors discuss implications for future cross-cultural group research and international management.

Cholecystokinin receptors on gallbladder muscle and pancreatic acinar cells: a comparative study

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

von Schrenck, T.; Moran, T.H.; Heinz-Erian, P.

1988-10-01

To compare receptors for cholecystokinin (CCK) in pancreas and gallbladder, we measured binding of 125I-Bolton-Hunter-labeled CCK-8 (125I-BH-CCK-8) to tissue sections from guinea pig gallbladder and pancreas under identical conditions. In both tissues, binding had similar time-, temperature-, and pH dependence, was reversible, saturable and inhibited only by CCK related peptides or CCK receptor antagonists. Autoradiography localized 125I-BH-CCK-8 binding to the smooth muscle layer in the gallbladder. Binding of 125I-BH-CCK-8 to gallbladder sections was inhibited by various agonists with the following potencies (IC50):CCK-8 (0.4 nM) greater than des(SO3)CCK-8 (0.07 microM) greater than gastrin-17-I (1.7 +/- 0.3 microM) and by various receptormore » antagonists with the following potencies: L364,718 (1.5 nM) greater than CR 1409 (0.19 microM) greater than asperlicin = CBZ-CCK-(27-32)-NH2 (1 microM) greater than Bt2cGMP (120 microM). Similar potencies were found for the agonists and antagonists for pancreas sections. Inhibition of binding of 125I-BH-CCK-8 by 11 different analogues of proglumide gave similar potencies for both pancreas and gallbladder. The potencies of agonists in stimulating and antagonists in inhibiting CCK-stimulated contraction or amylase release correlated closely with their abilities to inhibit 125I-BH-CCK-8 binding to gallbladder or pancreas sections or acini, respectively. The present results demonstrate and characterize a method that can be used to compare the CCK receptors in guinea pig gallbladder and pancreas under identical conditions. Moreover, this study demonstrates that gallbladder and pancreatic CCK receptors have similar affinities for the various agonists and antagonists tested and, therefore, provides no evidence that they represent different subtypes of CCK receptors that can be distinguished pharmacologically.« less

Short-Term Effects of Repeated Olfactory Administration of Homeopathic Sulphur or Pulsatilla on Electroencephalographic Alpha Power in Healthy Young Adults

PubMed Central

Bell, Iris R.; Brooks, Audrey J.; Howerter, Amy; Jackson, Nicholas; Schwartz, Gary E.

2011-01-01

Introduction Homeopathic pathogenetic trials usually rely on symptom self report measures. Adding objective biomarkers could enhance detection of subtle initial remedy effects. The present feasibility study examined electroencephalographic (EEG) effects of repeated olfactory administration of two polycrest remedies. Methods College student volunteers (ages 18–30, both sexes) from an introductory psychology course were screened for good health and relatively elevated Sulphur OR Pulsatilla symptom scores on the Homeopathic Constitutional Type Questionnaire. Subjects underwent a series of 3 once-weekly double-blind sessions during which they repeatedly sniffed the remedy matched to their CTQ type and solvent controls. Each remedy was given in a 6c, 12c, and 30c potency, one potency per week, in randomly assigned order. Solvent controls included both plain distilled water and a water-ethanol (95%) solution. All sniff test solutions were further diluted just prior to laboratory sessions (0.5 ml test solution in 150 ml distilled water). Within a session, remedies and control solvents were administered via 2-second sniffs (8 sniffs of each of 4 different succussion levels for the potency in randomized order). Primary outcome variable was relative EEG power (alpha 1 8–10 hertz; alpha 2 10–12 hertz) averaged over 19 electrode sites, including all succussions for a given potency. Results Mixed-effect models revealed significant main effects for remedy type (Sulphur>Pulsatilla) in both alpha bands, controlling for gender, baseline resting EEG alpha, and solvent control responses. Additional analyses showed significant non-linear interactions between dilution and time (weekly session) in alpha 2 for both remedies and alpha 1 for Sulphur. Conclusion EEG alpha offers an objective biomarker of remedy effects for future studies and potential method for distinguishing time-dependent effects of specific remedies and remedy potencies from one another. PMID:21962194

Developing structure-activity relationships from an HTS hit for inhibition of the Cks1-Skp2 protein-protein interaction.

PubMed

Singh, Rajinder; Sran, Arvinder; Carroll, David C; Huang, Jianing; Tsvetkov, Lyuben; Zhou, Xiulan; Sheung, Julie; McLaughlin, John; Issakani, Sarkiz D; Payan, Donald G; Shaw, Simon J

2015-11-15

Structure-activity relationships have been developed around 5-bromo-8-toluylsulfonamidoquinoline 1 a hit compound in an assay for the interaction of the E3 ligase Skp2 with Cks1, part of the SCF ligase complex. Disruption of this protein-protein interaction results in higher levels of CDK inhibitor p27, which can act as a tumor suppressor. The results of the SAR developed highlight the relationship between the sulfonamide and quinoline nitrogen, while also suggesting that an aryl substituent at the 5-position of the quinoline ring contributes to the potency in the interaction assay. Compounds showing potency in the interaction assay result in greater levels of p27 and have been shown to inhibit cell growth of two p27 sensitive tumor cell lines. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of agonist-receptor modeling to the sweetness synergy between high fructose corn syrup and sucralose, and between high-potency sweeteners.

PubMed

Wolf, P A; Bridges, J R; Wicklund, R

2010-03-01

The agonist-receptor-transducer model of D. Ennis is applied to beverage formulations sweetened with high fructose corn syrup, sucralose, and other high-potency sweeteners, confirming the utility of the model, and supports the growing volume of evidence for multiple binding sites on the sweetness receptor. The model is further simplified to require less parameters for other sweetener blend systems whenever potency information is available for the single sweeteners.

The spermicidal potency of Coca-Cola and Pepsi-Cola.

PubMed

Hong, C Y; Shieh, C C; Wu, P; Chiang, B N

1987-09-01

The inhibitory effect of Old Coke, caffeine-free New Coke, New Coke, Diet Coke and Pepsi-Cola on human sperm motility was studied with a trans-membrane migration method. None of them could decrease sperm motility to less than 70% of control within one hour. A previous study which claimed a marked variation of spermicidal potencies among different formulations of Coca-Cola could not be confirmed. Even if cola has a spermicidal effect, its potency is relatively weak as compared with other well-known spermicidal agents.

Stereotype threat spillover: how coping with threats to social identity affects aggression, eating, decision making, and attention.

PubMed

Inzlicht, Michael; Kang, Sonia K

2010-09-01

Stereotype threat spillover is a situational predicament in which coping with the stress of stereotype confirmation leaves one in a depleted volitional state and thus less likely to engage in effortful self-control in a variety of domains. We examined this phenomenon in 4 studies in which we had participants cope with stereotype and social identity threat and then measured their performance in domains in which stereotypes were not "in the air." In Study 1 we examined whether taking a threatening math test could lead women to respond aggressively. In Study 2 we investigated whether coping with a threatening math test could lead women to indulge themselves with unhealthy food later on and examined the moderation of this effect by personal characteristics that contribute to identity-threat appraisals. In Study 3 we investigated whether vividly remembering an experience of social identity threat results in risky decision making. Finally, in Study 4 we asked whether coping with threat could directly influence attentional control and whether the effect was implemented by inefficient performance monitoring, as assessed by electroencephalography. Our results indicate that stereotype threat can spill over and impact self-control in a diverse array of nonstereotyped domains. These results reveal the potency of stereotype threat and that its negative consequences might extend further than was previously thought. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Computer-aided identification, synthesis, and biological evaluation of novel inhibitors for botulinum neurotoxin serotype A

DOE PAGES

Teng, Y. G.; Berger, W. T.; Nesbitt, N. M.; ...

2015-07-27

Botulinum neurotoxins (BoNTs) are among the most potent biological toxin known to humans, and are classified as Category A bioterrorism agents by the Centers for Disease Control and prevention (CDC). There are seven known BoNT serotypes (A-G) which have been thus far identified in literature. BoNTs have been shown to block neurotransmitter release by cleaving proteins of the soluble NSF attachment protein receptor (SNARE) complex. Disruption of the SNARE complex precludes motor neuron failure which ultimately results in flaccid paralysis in humans and animals. Currently, there are no effective therapeutic treatments against the neurotoxin light chain (LC) after translocation intomore » the cytosols of motor neurons. In this work, high-throughput virtual screening was employed to screen a library of commercially available compounds from ZINC database against BoNT/A-LC. Among the hit compounds from the in-silico screening, two lead compounds were identified and found to have potent inhibitory activity against BoNT/A-LC in vitro, as well as in Neuro-2a cells. A few analogues of the lead compounds were synthesized and their potency examined. One of these analogues showed an enhanced activity than the lead compounds« less

In vitro stability, potency, and dissolution of duloxetine enteric-coated pellets after exposure to applesauce, apple juice, and chocolate pudding.

PubMed

Wells, Kevin A; Losin, William G

2008-07-01

Difficulty swallowing is a common problem in the clinical setting, particularly in elderly patients, and can significantly affect an individual's ability to maintain a proper level of nutrition. The purpose of this in vitro study was to determine if mixing duloxetine enteric-coated pellets in food substances is an acceptable alternative method for administering this oral formulation to patients with swallowing difficulties. To determine whether administration in food substances with varying pH values (applesauce and apple juice, pH = approximately 3.5; chocolate pudding, pH = approximately 5.5-6.0) affects the enteric coating of the formulation, duloxetine pellets (ie, the contents of a 20-mg duloxetine capsule) were exposed to applesauce, apple juice, and chocolate pudding at room temperature and tested in triplicate for potency and impurities; for dissolution, 6 replicates were tested. To assess product stability and integrity of the enteric coating, potency, impurities, and dissolution tests of the pellets were conducted and compared with pellets not exposed to food. The duloxetine pellets were extracted from the food material using a solution of 0.1 normal (N) hydrochloric acid (HCl) prepared from concentrated HCl (commercially available) and deionized water. For the potency and impurities tests, a 40:60 solution of acetonitrile and pH 8.0 phosphate buffer was used as the sample solvent to extract the active pharmaceutical ingredient from the formulation to prepare the samples for testing. The amount of active pharmaceutical ingredient released (in vitro dissolution) from the pellets after exposure to the food substances was determined using 2 media solutions, 0.1 N HCl followed by pH 6.8 phosphate buffer. Applesauce and chocolate pudding were selected as vehicles for oral administration, while apple juice was intended to be used as a wash for a nasogastric tube. Mean (SD) potency results for the 20-mg capsule strength were 20.256 (0.066), 20.222 (0.163), and 19.961 (0.668) mg/capsule for the comparator not exposed to food, the sample exposed to applesauce, and the sample exposed to apple juice, respectively. However, exposure to chocolate pudding altered the integrity of the pellet's enteric coating (mean [SD] potency results, 17.780 [1.605] mg/capsule). Results of impurities testing suggested that none of the test foods caused significant degradation of the drug product. Mean dissolution results found that after 2 hours in 0.1 N HCl, < or = 1% of duloxetine was released from the comparator and pellets exposed to applesauce and apple juice. However, the mean dissolution profile of the sample exposed to pudding reported near-total release (90%) after 2 hours in 0.1 N HCl during the gastric challenge portion of the dissolution test. Results from this study found that the enteric coating of duloxetine pellets mixed with applesauce or apple juice was not negatively affected. The pellets were stable at room temperature for < or = 2 hours and should quantitatively allow delivery of the full capsule dose, provided that the pellet integrity is maintained (ie, not crushed, chewed, or otherwise broken). Therefore, mixing duloxetine pellets with applesauce or apple juice appears to be an acceptable vehicle for administration. However, exposing the pellets to chocolate pudding damaged the pellets' enteric coating, suggesting that pudding may be an unacceptable vehicle for administration.

Establishment of a biological reference preparation for hepatitis A vaccine (inactivated, non-adsorbed).

PubMed

Stalder, J; Costanzo, A; Daas, A; Rautmann, G; Buchheit, K-H

2010-04-01

A reference standard calibrated in International Units (IU) is needed for the in vitro potency assay of hepatitis A vaccines prepared by formalin-inactivation of purified hepatitis A virus grown in cell cultures. Thus, a project was launched by the European Directorate for the Quality of Medicines & HealthCare (EDQM) to establish one or more non-adsorbed inactivated hepatitis A vaccine reference preparation(s) as working standard(s), calibrated against the 1st International Standard (IS), for the in vitro potency assay (ELISA) of all vaccines present on the European market. Four non-adsorbed liquid preparations of formalin-inactivated hepatitis A antigen with a known antigen content were obtained from 3 manufacturers as candidate Biological Reference Preparations (BRPs). Thirteen laboratories participated in the collaborative study. They were asked to use an in vitro ELISA method adapted from a commercially available kit for the detection of antibodies to hepatitis A virus. In-house validated assays were to be run in parallel, where available. Some participants also included commercially available hepatitis A vaccines in the assays, after appropriate desorption. During the collaborative study, several participants using the standard method were faced with problems with some of the most recent lots of the test kits. Due to these problems, the standard method did not perform satisfactorily and a high number of assays were invalid, whereas the in-house methods appeared to perform better. Despite this, the overall mean results of the valid assays using both methods were in agreement. Nonetheless, it was decided to base the assignment of the potency values on the in-house methods only. The results showed that all candidate BRPs were suitable for the intended purpose. However, based on availability of the material and on the results of end-product testing, 2 candidate reference preparations, Samples C and D, were selected. Both were from the same batch but filled on different days; no statistically significant difference in potency was observed. They were thus combined in 1 single batch. The candidate preparation (Sample C/D) was adopted at the June 2009 session of the European Pharmacopoeia (Ph. Eur.) Commission as the Ph. Eur. BRP batch 1 for hepatitis A vaccine (inactivated, non-adsorbed), with an assigned potency of 12 IU/ml for in vitro antigen content assays. Accelerated degradation studies have been initiated. The preliminary data show that the BRP is stable at the recommended storage temperature (< -50 degrees C). The BRP will be monitored at regular intervals throughout its lifetime.

Hydraphiles enhance antimicrobial potency against Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis.

PubMed

Patel, Mohit B; Garrad, Evan C; Stavri, Ariel; Gokel, Michael R; Negin, Saeedeh; Meisel, Joseph W; Cusumano, Zachary; Gokel, George W

2016-06-15

Hydraphiles are synthetic amphiphiles that form ion-conducting pores in liposomal membranes. These pores exhibit open-close behavior when studied by planar bilayer conductance techniques. In previous work, we showed that when co-administered with various antibiotics to the DH5α strain of Escherichia coli, they enhanced the drug's potency. We report here potency enhancements at low concentrations of hydraphiles for the structurally and mechanistically unrelated antibiotics erythromycin, kanamycin, rifampicin, and tetracycline against Gram negative E. coli (DH5α and K-12) and Pseudomonas aeruginosa, as well as Gram positive Bacillus subtilis. Earlier work suggested that potency increases correlated to ion transport function. The data presented here comport with the function of hydraphiles to enhance membrane permeability in addition to, or instead of, their known function as ion conductors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Actions of Agonists, Fipronil and Ivermectin on the Predominant In Vivo Splice and Edit Variant (RDLbd, I/V) of the Drosophila GABA Receptor Expressed in Xenopus laevis Oocytes

PubMed Central

Suwanmanee, Siros; Buckingham, Steven David; Biggin, Philip; Sattelle, David

2014-01-01

Ionotropic GABA receptors are the targets for several classes of insecticides. One of the most widely-studied insect GABA receptors is RDL (resistance to dieldrin), originally isolated from Drosophila melanogaster. RDL undergoes alternative splicing and RNA editing, which influence the potency of GABA. Most work has focussed on minority isoforms. Here, we report the first characterisation of the predominant native splice variant and RNA edit, combining functional characterisation with molecular modelling of the agonist-binding region. The relative order of agonist potency is GABA> muscimol> TACA> β-alanine. The I/V edit does not alter the potency of GABA compared to RDLbd. Docking calculations suggest that these agonists bind and activate RDLbdI/V through a similar binding mode. TACA and β-alanine are predicted to bind with lower affinity than GABA, potentially explaining their lower potency, whereas the lower potency of muscimol and isoguvacine cannot be explained structurally from the docking calculations. The A301S (resistance to dieldrin) mutation reduced the potency of antagonists picrotoxin, fipronil and pyrafluprole but the I/V edit had no measurable effect. Ivermectin suppressed responses to GABA of RDLbdI/V, RDLbd and RDLbdI/VA301S. The dieldrin resistant variant also showed reduced sensitivity to Ivermectin. This study of a highly abundant insect GABA receptor isoform will help the design of new insecticides. PMID:24823815

An Assessment of the Model of Concentration Addition for Predicting the Estrogenic Activity of Chemical Mixtures in Wastewater Treatment Works Effluents

PubMed Central

Thorpe, Karen L.; Gross-Sorokin, Melanie; Johnson, Ian; Brighty, Geoff; Tyler, Charles R.

2006-01-01

The effects of simple mixtures of chemicals, with similar mechanisms of action, can be predicted using the concentration addition model (CA). The ability of this model to predict the estrogenic effects of more complex mixtures such as effluent discharges, however, has yet to be established. Effluents from 43 U.K. wastewater treatment works were analyzed for the presence of the principal estrogenic chemical contaminants, estradiol, estrone, ethinylestradiol, and nonylphenol. The measured concentrations were used to predict the estrogenic activity of each effluent, employing the model of CA, based on the relative potencies of the individual chemicals in an in vitro recombinant yeast estrogen screen (rYES) and a short-term (14-day) in vivo rainbow trout vitellogenin induction assay. Based on the measured concentrations of the four chemicals in the effluents and their relative potencies in each assay, the calculated in vitro and in vivo responses compared well and ranged between 3.5 and 87 ng/L of estradiol equivalents (E2 EQ) for the different effluents. In the rYES, however, the measured E2 EQ concentrations in the effluents ranged between 0.65 and 43 ng E2 EQ/L, and they varied against those predicted by the CA model. Deviations in the estimation of the estrogenic potency of the effluents by the CA model, compared with the measured responses in the rYES, are likely to have resulted from inaccuracies associated with the measurement of the chemicals in the extracts derived from the complex effluents. Such deviations could also result as a consequence of interactions between chemicals present in the extracts that disrupted the activation of the estrogen response elements in the rYES. E2 EQ concentrations derived from the vitellogenic response in fathead minnows exposed to a series of effluent dilutions were highly comparable with the E2 EQ concentrations derived from assessments of the estrogenic potency of these dilutions in the rYES. Together these data support the use of bioassays for determining the estrogenic potency of WwTW effluents, and they highlight the associated problems for modeling approaches that are reliant on measured concentrations of estrogenic chemicals. PMID:16818252

Application of short-term inhalation studies to assess the inhalation toxicity of nanomaterials

PubMed Central

2014-01-01

Background A standard short-term inhalation study (STIS) was applied for hazard assessment of 13 metal oxide nanomaterials and micron-scale zinc oxide. Methods Rats were exposed to test material aerosols (ranging from 0.5 to 50 mg/m3) for five consecutive days with 14- or 21-day post-exposure observation. Bronchoalveolar lavage fluid (BALF) and histopathological sections of the entire respiratory tract were examined. Pulmonary deposition and clearance and test material translocation into extra-pulmonary organs were assessed. Results Inhaled nanomaterials were found in the lung, in alveolar macrophages, and in the draining lymph nodes. Polyacrylate-coated silica was also found in the spleen, and both zinc oxides elicited olfactory epithelium necrosis. None of the other nanomaterials was recorded in extra-pulmonary organs. Eight nanomaterials did not elicit pulmonary effects, and their no observed adverse effect concentrations (NOAECs) were at least 10 mg/m3. Five materials (coated nano-TiO2, both ZnO, both CeO2) evoked concentration-dependent transient pulmonary inflammation. Most effects were at least partially reversible during the post-exposure period. Based on the NOAECs that were derived from quantitative parameters, with BALF polymorphonuclear (PMN) neutrophil counts and total protein concentration being most sensitive, or from the severity of histopathological findings, the materials were ranked by increasing toxic potency into 3 grades: lower toxic potency: BaSO4; SiO2.acrylate (by local NOAEC); SiO2.PEG; SiO2.phosphate; SiO2.amino; nano-ZrO2; ZrO2.TODA; ZrO2.acrylate; medium toxic potency: SiO2.naked; higher toxic potency: coated nano-TiO2; nano-CeO2; Al-doped nano-CeO2; micron-scale ZnO; coated nano-ZnO (and SiO2.acrylate by systemic no observed effect concentration (NOEC)). Conclusion The STIS revealed the type of effects of 13 nanomaterials, and micron-scale ZnO, information on their toxic potency, and the location and reversibility of effects. Assessment of lung burden and material translocation provided preliminary biokinetic information. Based upon the study results, the STIS protocol was re-assessed and preliminary suggestions regarding the grouping of nanomaterials for safety assessment were spelled out. PMID:24708749

How Effective Are Pictures in Basal Readers?

ERIC Educational Resources Information Center

Legenza, Alice; Knafle, June D.

1978-01-01

When a formula for assessing the language stimulation value of pictures was applied to several basal readers, the results indicated that most of the pictures were of low potency or stimulation potential. (MKM)

Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains.

PubMed

Westdijk, Janny; Koedam, Patrick; Barro, Mario; Steil, Benjamin P; Collin, Nicolas; Vedvick, Thomas S; Bakker, Wilfried A M; van der Ley, Peter; Kersten, Gideon

2013-02-18

Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titres (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotypes 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7-20-27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants. Copyright © 2013 Elsevier Ltd. All rights reserved.

Local lymph node assay (LLNA): comparison of different protocols by testing skin-sensitizing epoxy resin system components.

PubMed

Gamer, Armin O; Nies, Eberhard; Vohr, Hans-Werner

2008-12-01

Thirteen epoxy resin system components were tested in the LLNA with regard to their sensitizing potency. Lymph node stimulation was quantified not only by measuring the incorporation of [3H]-thymidine into the ear lymph nodes but also the counts of cells recovered from these organs. Equivalent figures were obtained with both endpoints used for the evaluation of lymph node cell proliferation if the reference stimulation indices were adjusted. When dissolved in acetone, all test substances showed skin-sensitizing potential, mainly on the boundary between "strong" and "moderate" according to common potency evaluation schemes. Replacing acetone with acetone/olive oil (4:1) as a vehicle for four selected test items, resulted in considerably lower estimated concentrations for sensitization induction. The challenges in comparing the results obtained by different LLNA variations are discussed.

Principles for identification of High Potency Category Chemicals for which the Dermal Sensitisation Threshold (DST) approach should not be applied.

PubMed

Roberts, David W; Api, Anne Marie; Safford, Robert J; Lalko, Jon F

2015-08-01

An essential step in ensuring the toxicological safety of chemicals used in consumer products is the evaluation of their skin sensitising potential. The sensitising potency, coupled with information on exposure levels, can be used in a Quantitative Risk Assessment (QRA) to determine an acceptable level of a given chemical in a given product. Where consumer skin exposure is low, a risk assessment can be conducted using the Dermal Sensitisation Threshold (DST) approach, avoiding the need to determine potency experimentally. Since skin sensitisation involves chemical reaction with skin proteins, the first step in the DST approach is to assess, on the basis of the chemical structure, whether the chemical is expected to be reactive or not. Our accompanying publication describes the probabilistic derivation of a DST of 64 μg/cm(2) for chemicals assessed as reactive. This would protect against 95% of chemicals assessed as reactive, but the remaining 5% would include chemicals with very high potency. Here we discuss the chemical properties and structural features of high potency sensitisers, and derive an approach whereby they can be identified and consequently excluded from application of the DST. Copyright © 2015 Elsevier Inc. All rights reserved.

Collaborative studies on the development of national reference standards for potency determination of H7N9 influenza vaccine

PubMed Central

Li, Changgui; Xu, Kangwei; Hashem, Anwar; Shao, Ming; Liu, Shuzhen; Zou, Yong; Gao, Qiang; Zhang, Yongchao; Yuan, Liyong; Xu, Miao; Li, Xuguang; Wang, Junzhi

2015-01-01

The outbreak of human infections of a novel avian influenza virus A (H7N9) prompted the development of the vaccines against this virus. Like all types of influenza vaccines, H7N9 vaccine must be tested for its potency prior to being used in humans. However, the unavailability of international reference reagents for the potency determination of H7N9 vaccines substantially hinders the progress in vaccine development. To facilitate clinical development, we enlisted 5 participants in a collaborative study to develop critical reagents used in Single Radial Immunodiffusion (SRID), the currently acceptable assay for potency determination of influenza vaccine. Specifically, the hemagglutinin (HA) content of one vaccine bulk for influenza A (H7N9), herein designated as Primary Liquid Standard (PLS), was determined by SDS-PAGE. In addition, the freeze-dried antigen references derived from PLS were prepared to enhance the stability for long term storage. The final HA content of lyophilized antigen references were calibrated against PLS by SRID assay in a collaborative study. Importantly, application of these national reference standards to potency analyses greatly facilitated the development of H7N9 vaccines in China. PMID:25970793

Discovery of novel Pim-1 kinase inhibitors by a hierarchical multistage virtual screening approach based on SVM model, pharmacophore, and molecular docking.

PubMed

Ren, Ji-Xia; Li, Lin-Li; Zheng, Ren-Lin; Xie, Huan-Zhang; Cao, Zhi-Xing; Feng, Shan; Pan, You-Li; Chen, Xin; Wei, Yu-Quan; Yang, Sheng-Yong

2011-06-27

In this investigation, we describe the discovery of novel potent Pim-1 inhibitors by employing a proposed hierarchical multistage virtual screening (VS) approach, which is based on support vector machine-based (SVM-based VS or SB-VS), pharmacophore-based VS (PB-VS), and docking-based VS (DB-VS) methods. In this approach, the three VS methods are applied in an increasing order of complexity so that the first filter (SB-VS) is fast and simple, while successive ones (PB-VS and DB-VS) are more time-consuming but are applied only to a small subset of the entire database. Evaluation of this approach indicates that it can be used to screen a large chemical library rapidly with a high hit rate and a high enrichment factor. This approach was then applied to screen several large chemical libraries, including PubChem, Specs, and Enamine as well as an in-house database. From the final hits, 47 compounds were selected for further in vitro Pim-1 inhibitory assay, and 15 compounds show nanomolar level or low micromolar inhibition potency against Pim-1. In particular, four of them were found to have new scaffolds which have potential for the chemical development of Pim-1 inhibitors.

Terminalia ferdinandiana extracts as inhibitors of Giardia duodenalis proliferation: a new treatment for giardiasis.

PubMed

Rayan, P; Matthews, B; McDonnell, P A; Cock, I E

2015-07-01

Giardisis is a debilitating disease caused by gastrointestinal parasites of the genus Giardia. High-antioxidant T. ferdinandiana fruit extracts were investigated for the ability to block Giardia duodenalis growth. Methanolic and aqueous extracts had the most potent growth inhibitory activity (IC50 values of approximately 700 and 140 μg/ml, respectively). Ethyl acetate and chloroform extracts also inhibited G. duodenalis growth, albeit with lower potency. The hexane extract was completely devoid of G. duodenalis growth inhibitory activity. All extracts were nontoxic in the Artemia fransiscana bioassay. Nontargeted HPLC-quadrupole time-of-flight (QTOF) mass spectroscopy (with screening against three compound databases) putatively identified 17 compounds in all of the inhibitory extracts but not in the inactive hexane extract. The low toxicity of the Terminalia ferdinandiana fruit extracts and their potent G. duodenalis growth inhibitory bioactivity indicate their potential as medicinal agents in the treatment and prevention of this disease.

ArachnoServer 3.0: an online resource for automated discovery, analysis and annotation of spider toxins.

PubMed

Pineda, Sandy S; Chaumeil, Pierre-Alain; Kunert, Anne; Kaas, Quentin; Thang, Mike W C; Le, Lien; Nuhn, Michael; Herzig, Volker; Saez, Natalie J; Cristofori-Armstrong, Ben; Anangi, Raveendra; Senff, Sebastian; Gorse, Dominique; King, Glenn F

2018-03-15

ArachnoServer is a manually curated database that consolidates information on the sequence, structure, function and pharmacology of spider-venom toxins. Although spider venoms are complex chemical arsenals, the primary constituents are small disulfide-bridged peptides that target neuronal ion channels and receptors. Due to their high potency and selectivity, these peptides have been developed as pharmacological tools, bioinsecticides and drug leads. A new version of ArachnoServer (v3.0) has been developed that includes a bioinformatics pipeline for automated detection and analysis of peptide toxin transcripts in assembled venom-gland transcriptomes. ArachnoServer v3.0 was updated with the latest sequence, structure and functional data, the search-by-mass feature has been enhanced, and toxin cards provide additional information about each mature toxin. http://arachnoserver.org. support@arachnoserver.org. Supplementary data are available at Bioinformatics online.

Rationale for Further Medical and Health Research on High-Potency Sweeteners

PubMed Central

2012-01-01

High-potency or artificial sweeteners have historically been considered inert compounds without physiological consequences other than taste sensations. However, recent data suggest that some of these sweeteners have biological effects that may impact human health. Furthermore, there are significant gaps in our current knowledge of the pharmacokinetics of these sweeteners, their potential for “sweetener–drug interactions” and their impact on appetite and body weight regulation. Nine research needs are described that address some of the major unknown issues associated with ingestion of high-potency sweeteners. PMID:22539626

Rationale for further medical and health research on high-potency sweeteners.

PubMed

Schiffman, Susan S

2012-10-01

High-potency or artificial sweeteners have historically been considered inert compounds without physiological consequences other than taste sensations. However, recent data suggest that some of these sweeteners have biological effects that may impact human health. Furthermore, there are significant gaps in our current knowledge of the pharmacokinetics of these sweeteners, their potential for "sweetener-drug interactions" and their impact on appetite and body weight regulation. Nine research needs are described that address some of the major unknown issues associated with ingestion of high-potency sweeteners.

Evaluation of the potential carcinogenicity of benzotrichloride (97-07-7). Final report

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

Not Available

1988-06-01

Benzotrichloride is a probable human carcinogen, classified as weight-of-evidence Group B1 under the EPA Guidelines for Carcinogen Risk Assessment. Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is Limited. The potency factor (F) for benzotrichloride is estimated to be 58.0 (mg/kg/day)(-1), placing it in potency group 2 according to the CAG's methodology for evaluating potential carcinogens. Combining the weight-of-evidence group and the potency group, benzotrichloride is assigned a MEDIUM hazard ranking.

Robotic radical prostatectomy for elderly patients: probability of achieving continence and potency 1 year after surgery.

PubMed

Shikanov, Sergey; Desai, Vikas; Razmaria, Aria; Zagaja, Gregory P; Shalhav, Arieh L

2010-05-01

We assessed the probability of achieving continence and potency after robotic radical prostatectomy in elderly patients. The cohort included 1,436 robotic radical prostatectomy cases performed at our institution between 2003 and 2008. Continence (pad-free) and potency (erection sufficient for intercourse) at baseline and 1 year after surgery were evaluated by the UCLA-PCI questionnaire. Point estimates of the predicted probabilities of continence and potency for age 65, 70 and 75 years were calculated from multivariate logistic regression models adjusting for age, nerve sparing status, baseline International Prostate Symptom Score and baseline Sexual Health Inventory for Men score. Patients who were impotent before surgery or those who received hormones or radiation within 1 year after surgery were censored. Mean patient age was 60 years (range 38 to 85) with 25% older than 65 years and 77 (5%) 70 years old or older. Age (OR 0.97, p = 0.002), baseline I-PSS (OR 0.98, p = 0.02) and Sexual Health Inventory for Men scores (OR 1.02, p = 0.005) were independently associated with being pad-free. Age (OR 0.92, p <0.0001), baseline Sexual Health Inventory for Men score (OR 1.1, p <0.0001) and bilateral nerve sparing (OR 2.92, p <0.0001) were independently associated with achieving potency. Predicted probabilities (95% CI) of postoperative 1-year continence at age 65, 70 and 75 years were 0.66 (0.63, 0.69), 0.63 (0.57, 0.68) and 0.59 (0.52, 0.66), respectively. The corresponding probabilities of postoperative 1-year potency after bilateral nerve sparing were 0.66 (0.62, 0.71), 0.56 (0.49, 0.64) and 0.46 (0.36, 0.56). In our experience there is an acceptable probability of achieving continence and potency after robotic radical prostatectomy in selected elderly patients. 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Comparison of in vivo genotoxic and carcinogenic potency to augment mode of action analysis: Case study with hexavalent chromium.

PubMed

Thompson, Chad M; Bichteler, Anne; Rager, Julia E; Suh, Mina; Proctor, Deborah M; Haws, Laurie C; Harris, Mark A

2016-04-01

Recent analyses-highlighted by the International Workshops on Genotoxicity Testing Working Group on Quantitative Approaches to Genetic Toxicology Risk Assessment-have identified a correlation between (log) estimates of a carcinogen's in vivo genotoxic potency and in vivo carcinogenic potency in typical laboratory animal models, even when the underlying data have not been matched for tissue, species, or strain. Such a correlation could have important implications for risk assessment, including informing the mode of action (MOA) of specific carcinogens. When in vivo genotoxic potency is weak relative to carcinogenic potency, MOAs other than genotoxicity (e.g., endocrine disruption or regenerative hyperplasia) may be operational. Herein, we review recent in vivo genotoxicity and carcinogenicity data for hexavalent chromium (Cr(VI)), following oral ingestion, in relevant tissues and species in the context of the aforementioned correlation. Potency estimates were generated using benchmark doses, or no-observable-adverse-effect-levels when data were not amenable to dose-response modeling. While the ratio between log values for carcinogenic and genotoxic potency was ≥1 for many compounds, the ratios for several Cr(VI) datasets (including in target tissue) were less than unity. In fact, the ratios for Cr(VI) clustered closely with ratios for chloroform and diethanolamine, two chemicals posited to have non-genotoxic MOAs. These findings suggest that genotoxicity may not play a major role in the cancers observed in rodents following exposure to high concentrations of Cr(VI) in drinking water-a finding consistent with recent MOA and adverse outcome pathway (AOP) analyses concerning Cr(VI). This semi-quantitative analysis, therefore, may be useful to augment traditional MOA and AOP analyses. More case examples will be needed to further explore the general applicability and validity of this approach for human health risk assessment. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Gonadal hormones do not alter the development of antinociceptive tolerance to delta-9-tetrahydrocannabinol in adult rats

PubMed Central

Wakley, Alexa A; Wiley, Jenny L; Craft, Rebecca M

2015-01-01

The purpose of this study was to determine whether sex differences in the development of antinociceptive tolerance to delta-9-tetrahydrocannabinol (THC) are due to activational effects of gonadal hormones. Rats were sham-gonadectomized (sham-GDX) or gonadectomized (GDX). GDX females received no hormone replacement (GDX+0), estradiol (GDX+E2), progesterone (GDX+P4), or both (GDX+E2/P4). GDX male rats received no hormone (GDX+0) or testosterone (GDX+T). Two weeks later, antinociceptive potency of THC was determined (pre-chronic test) on the warm water tail withdrawal and paw pressure assays. Vehicle or a sex-specific THC dose (females, 5.7 mg/kg, males, 9.9 mg/kg) was administered twice-daily for 9 days, then the THC dose-effect curves were re-determined (post-chronic test). On the pre-chronic test (both assays), THC was more potent in sham-GDX females than males, and gonadectomy did not alter this sex difference. In GDX females, P4 significantly decreased THC’s antinociceptive potency, whereas E2 had no effect. In GDX males, T did not alter THC’s antinociceptive potency. After chronic THC treatment, THC’s antinociceptive potency was decreased more in sham-GDX females than males, on the tail withdrawal test; this sex difference in tolerance was not altered in GDX or hormone-treated groups. These results suggest that greater antinociceptive tolerance in females, which occurred despite females receiving 40% less THC than males, is not due to activational effects of gonadal hormones. PMID:25863271

Urinary and sexual function outcomes among different age groups after robot-assisted laparoscopic prostatectomy.

PubMed

Mendiola, Frederick P; Zorn, Kevin C; Mikhail, Albert A; Lin, Shang; Orvieto, Marcelo A; Zagaja, Gregory P; Shalhav, Arieh L

2008-03-01

We present an age-stratified prospective assessment of urinary and sexual function of 300 patients after robot-assisted laparoscopic prostatectomy (RALP). Subjective assessment data of continence and potency were collected for different age groups (<50, 50-59, and > or =60 years old) preoperatively, and at 1, 3, 6, and 12 months after RALP. Health-related quality of life questionnaires evaluated return of baseline urinary and sexual function at the same time intervals. The three age groups included 21, 129, and 150 patients (aged <50, 50-59, and >60 years old, respectively). Using Kaplan-Meier curves, younger men achieved subjective continence significantly earlier than older age groups when age groups were compared using a 60-year-old cut-off point (P = 0.02). However, subjective continence was noted to be equal among all age groups after 1 year of follow-up. Time to recovery of subjective potency among age groups shows a significant difference in favor of the younger age group (P = 0.01) Objective urinary function is equal between age groups at all time points, while objective sexual function assessment showed a trend toward better results in the younger age group. Younger men will likely have an earlier return of continence and potency compared to older men after RALP. However, continence outcomes were noted to be equal among age groups after I year of follow-up, while younger men continue to report superior potency outcomes compared to older men over the first postoperative year. Such findings are valuable in counseling older men undergoing this procedure.

Advances in neglected tropical disease vaccines: Developing relative potency and functional assays for the Na-GST-1/Alhydrogel hookworm vaccine.

PubMed

Brelsford, Jill B; Plieskatt, Jordan L; Yakovleva, Anna; Jariwala, Amar; Keegan, Brian P; Peng, Jin; Xia, Pengjun; Li, Guangzhao; Campbell, Doreen; Periago, Maria Victoria; Correa-Oliveira, Rodrigo; Bottazzi, Maria Elena; Hotez, Peter J; Diemert, David; Bethony, Jeffrey M

2017-02-01

A new generation of vaccines for the neglected tropical diseases (NTDs) have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, vaccine stability testing programs. A key measure of vaccine stability testing is "relative potency" or the immunogenicity of the vaccine during storage. As with most NTD vaccines, the Na-GST-1/Alhydrogel Hookworm Vaccine was not developed by attenuation or inactivation of the pathogen (Necator americanus), so conventional methods for measuring relative potency are not relevant for this investigational product. Herein, we describe a novel relative potency testing program and report for the first time on the clinical lot of this NTD vaccine during its first 60 months of storage at 2-8°C. We also describe the development of a complementary functional assay that measures the ability of IgG from animals or humans immunized with Na-GST-1/Alhydrogel to neutralize this important hookworm enzyme. While 90% inhibition of the catalytic activity of Na-GST-1 was achieved in animals immunized with Na-GST-1/Alhydrogel, lower levels of inhibition were observed in immunized humans. Moreover, anti-Na-GST-1 antibodies from volunteers in non-hookworm endemic areas were better able to inhibit catalytic activity than anti-Na-GST-1 antibodies from volunteers resident in hookworm endemic areas. The results described herein provide the critical tools for the product development of NTD vaccines.

Comparison of Emetic Potencies of the 8-Ketotrichothecenes Deoxynivalenol, 15-Acetyldeoxynivalenol, 3-Acetyldeoxynivalenol, Fusarenon X, and Nivalenol

PubMed Central

Pestka, James J.

2013-01-01

Although the acute toxic effects of trichothecene mycotoxin deoxynivalenol (DON or vomitoxin), a known cause of human food poisoning, have been well characterized in several animal species, much less is known about closely related 8-ketotrichothecenes that similarly occur in cereal grains colonized by toxigenic fusaria. To address this, we compared potencies of DON, 15-acetyldeoxynivalenol (15-ADON), 3-acetyldeoxynivalenol (3-ADON), fusarenon X (FX), and nivalenol (NIV) in the mink emesis model following intraperitoneal (ip) and oral administration. All five congeners dose-dependently induced emesis by both administration methods. With increasing doses, there were marked decreases in latency to emesis with corresponding increases in emesis duration and number of emetic events. The effective doses resulting in emetic events in 50% of the animals for ip exposure to DON, 15-ADON, 3-ADON, FX, and NIV were 80, 170, 180, 70, and 60 µg/kg bw, respectively, and for oral exposure, they were 30, 40, 290, 30, and 250 µg/kg bw, respectively. The emetic potency of DON determined here was comparable to that reported in analogous studies conducted in pigs and dogs, suggesting that the mink is a suitable small animal model for investigating acute trichothecene toxicity. The use of a mouse pica model, based on the consumption of kaolin, was also evaluated as a possible surrogate for studying emesis but was found unsuitable. From a public health perspective, comparative emetic potency data derived from small animal models such as the mink should be useful for establishing toxic equivalency factors for DON and other trichothecenes. PMID:22997060

Efficacy of simple short-term in vitro assays for predicting the potential of metal oxide nanoparticles to cause pulmonary inflammation.

PubMed

Lu, Senlin; Duffin, Rodger; Poland, Craig; Daly, Paul; Murphy, Fiona; Drost, Ellen; Macnee, William; Stone, Vicki; Donaldson, Ken

2009-02-01

There has been concern regarding risks from inhalation exposure to nanoparticles (NPs). The large number of particles requiring testing means that alternative approaches to animal testing are needed. We set out to determine whether short-term in vitro assays that assess intrinsic oxidative stress potential and membrane-damaging potency of a panel of metal oxide NPs can be used to predict their inflammogenic potency. For a panel of metal oxide NPs, we investigated intrinsic free radical generation, oxidative activity in an extracellular environment, cytotoxicity to lung epithelial cells, hemolysis, and inflammation potency in rat lungs. All exposures were carried out at equal surface area doses. Only nickel oxide (NiO) and alumina 2 caused significant lung inflammation when instilled into rat lungs at equal surface area, suggesting that these two had extra surface reactivity. We observed significant free radical generation with 4 of 13 metal oxides, only one of which was inflammogenic. Only 3 of 13 were significantly hemolytic, two of which were inflammogenic. Potency in generating free radicals in vitro did not predict inflammation, whereas alumina 2 had no free radical activity but was inflammogenic. The hemolysis assay was correct in predicting the proinflammatory potential of 12 of 13 of the particles examined. Using a battery of simple in vitro tests, it is possible to predict the inflammogenicity of metal oxide NPs, although some false-positive results are likely. More research using a larger panel is needed to confirm the efficacy and generality of this approach for metal oxide NPs.

Exchanging the minimal cell binding fragments of tetanus neurotoxin in botulinum neurotoxin A and B impacts their toxicity at the neuromuscular junction and central neurons.

PubMed

Höltje, Markus; Schulze, Sebastian; Strotmeier, Jasmin; Mahrhold, Stefan; Richter, Karin; Binz, Thomas; Bigalke, Hans; Ahnert-Hilger, Gudrun; Rummel, Andreas

2013-12-01

The modular four domain structure of clostridial neurotoxins supports the idea to reassemble individual domains from tetanus and botulinum neurotoxins to generate novel molecules with altered pharmacological properties. To treat disorders of the central nervous system drug transporter molecules based on catalytically inactive clostridial neurotoxins circumventing the passage of the blood-brain-barrier are desired. Such molecules can be produced based on the highly effective botulinum neurotoxin serotype A incorporating the retrograde axonal sorting property of tetanus neurotoxin which is supposed to be encoded within its C-terminal cell binding domain HC. The corresponding exchange of the tetanus neurotoxin HC-fragment in botulinum neurotoxin A yielded the novel hybrid molecule AATT which displayed decreased potency at the neuromuscular junction like tetanus neurotoxin but exerted equal activity in cortical neurons compared to botulinum neurotoxin A wild-type. Minimizing the tetanus neurotoxin cell binding domain to its N- or C-terminal half drastically reduced the potencies of AATA and AAAT in cortical neurons indicating that the structural motif mediating sorting of tetanus neurotoxin is predominantly encoded within the entire HC-fragment. However, the reciprocal exchange resulted in TTAA which showed a similar potency as tetanus neurotoxin at the neuromuscular junction indicating that the tetanus neurotoxin portion prevents a high potency as observed for botulinum neurotoxins. In conclusion, clostridial neurotoxin based inactivated drug transporter for targeting central neurons should contain the cell binding domain of tetanus neurotoxin to exert its tropism for the central nervous system. Copyright © 2013 Elsevier Ltd. All rights reserved.

Targeted delivery of antisense oligonucleotides to hepatocytes using triantennary N-acetyl galactosamine improves potency 10-fold in mice.

PubMed

Prakash, Thazha P; Graham, Mark J; Yu, Jinghua; Carty, Rick; Low, Audrey; Chappell, Alfred; Schmidt, Karsten; Zhao, Chenguang; Aghajan, Mariam; Murray, Heather F; Riney, Stan; Booten, Sheri L; Murray, Susan F; Gaus, Hans; Crosby, Jeff; Lima, Walt F; Guo, Shuling; Monia, Brett P; Swayze, Eric E; Seth, Punit P

2014-07-01

Triantennary N-acetyl galactosamine (GalNAc, GN3: ), a high-affinity ligand for the hepatocyte-specific asialoglycoprotein receptor (ASGPR), enhances the potency of second-generation gapmer antisense oligonucleotides (ASOs) 6-10-fold in mouse liver. When combined with next-generation ASO designs comprised of short S-cEt (S-2'-O-Et-2',4'-bridged nucleic acid) gapmer ASOs, ∼ 60-fold enhancement in potency relative to the parent MOE (2'-O-methoxyethyl RNA) ASO was observed. GN3: -conjugated ASOs showed high affinity for mouse ASGPR, which results in enhanced ASO delivery to hepatocytes versus non-parenchymal cells. After internalization into cells, the GN3: -ASO conjugate is metabolized to liberate the parent ASO in the liver. No metabolism of the GN3: -ASO conjugate was detected in plasma suggesting that GN3: acts as a hepatocyte targeting prodrug that is detached from the ASO by metabolism after internalization into the liver. GalNAc conjugation also enhanced potency and duration of the effect of two ASOs targeting human apolipoprotein C-III and human transthyretin (TTR) in transgenic mice. The unconjugated ASOs are currently in late stage clinical trials for the treatment of familial chylomicronemia and TTR-mediated polyneuropathy. The ability to translate these observations in humans offers the potential to improve therapeutic index, reduce cost of therapy and support a monthly dosing schedule for therapeutic suppression of gene expression in the liver using ASOs. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Collaborative study for the establishment of erythropoietin BRP batch 4.

PubMed

Burns, C; Bristow, A F; Daas, A; Costanzo, A

2015-01-01

The European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for erythropoietin (EPO) is used as a working standard for potency determination of EPO preparations by in vivo bioassay as prescribed in the Ph. Eur. monograph Erythropoietin concentrated solution (1316). The BRP batch 3 was calibrated in 2006 and its stocks are depleted. The European Directorate for the Quality of Medicines & HealthCare (EDQM) thus initiated a project to calibrate a replacement batch in International Units against the WHO 3(rd) International Standard (IS) for Erythropoietin, recombinant, for bioassay (11/170). A Ph. Eur. Chemical Reference Substance (CRS) was established recently for use as reference in some of the physicochemical tests prescribed in the monograph. Therefore, the EPO BRP batch 4 was only calibrated for the normocythaemic and polycythaemic mouse in vivo bioassays described in the Assay section of the Ph. Eur. monograph (1316). The collaborative study involved seven laboratories from Europe, the USA and South America. The results confirmed that the candidate BRP (cBRP) is suitable for use as a reference preparation in the potency determination of EPO medicinal products by bioassay (using the normocythaemic or polycythaemic mouse methods). The outcome of the study enabled the Ph. Eur. Commission to establish the proposed standard as erythropoietin BRP batch 4 in November 2014 for use as a reference preparation solely for the polycythaemic and normocythaemic mouse bioassay, with an assigned potency of 13 000 IU/vial. Furthermore, the potency of BRP3 was confirmed during the study, thus warranting a good continuity of the IU.

Sexual Function After Three-Dimensional Conformal Radiotherapy for Prostate Cancer: Results From a Dose-Escalation Trial

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

Wielen, Gerard J. van der; Putten, Wim van; Incrocci, Luca

Purpose: The purpose of this study is to provide information about sexual function (SF) after three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer while taking important factors into account that influence SF. Methods and Materials: Between June 1997 and February 2003, a total of 268 patients from a randomized dose-escalation trial comparing 68 Gy and 78 Gy agreed to participate in an additional part of the trial that evaluated SF. Results: At baseline 28% of patients had erectile dysfunction (ED). After 1 year, 27% of the pretreatment potent patients had developed ED. After 2 years this percentage had increased to 36%.more » After 3 years it almost stabilized at 38%. Satisfaction with sexual life was significantly correlated with ED. After 2 years one third of the pre-treatment potent patients still had considerable to very much sexual desire and found sex (very) important. No significant differences were found between the two dose-arms. Potency aids were used on a regular base by 14% of the patients. Conclusion: By taking adjuvant hormonal therapy (HT), HT during follow-up and potency aids into account, we found a lower percentage of ED after 3D-CRT than reported in previous prospective studies. A large group of patients still had sexual desire, considered sex important and 14% used potency aids after 3D-CRT.« less

Improved in silico prediction of carcinogenic potency (TD50) and the risk specific dose (RSD) adjusted Threshold of Toxicological Concern (TTC) for genotoxic chemicals and pharmaceutical impurities.

PubMed

Contrera, Joseph F

2011-02-01

The Threshold of Toxicological Concern (TTC) is a level of exposure to a genotoxic impurity that is considered to represent a negligible risk to humans. The TTC was derived from the results of rodent carcinogenicity TD50 values that are a measure of carcinogenic potency. The TTC currently sets a default limit of 1.5 μg/day in food contact substances and pharmaceuticals for all genotoxic impurities without carcinogenicity data. Bercu et al. (2010) used the QSAR predicted TD50 to calculate a risk specific dose (RSD) which is a carcinogenic potency adjusted TTC for genotoxic impurities. This promising approach is currently limited by the software used, a combination of MC4PC (www.multicase.com) and a Lilly Inc. in-house software (VISDOM) that is not available to the public. In this report the TD50 and RSD were predicted using a commercially available software, SciQSAR (formally MDL-QSAR, www.scimatics.com) employing the same TD50 training data set and external validation test set that was used by Bercu et al. (2010). The results demonstrate the general applicability of QSAR predicted TD50 values to determine the RSDs for genotoxic impurities and the improved performance of SciQSAR for predicting TD50 values. Copyright © 2010 Elsevier Inc. All rights reserved.

Comparison between Newly Developed and Commercial Inhalant Skin Prick Test Reagents Using In Vivo and In Vitro Methods

PubMed Central

2018-01-01

Background We developed skin prick test (SPT) reagents for common inhalant allergens that reflected the real exposure in Korea. The study aim was to evaluate diagnostic usefulness and allergen potency of our inhalant SPT reagents in comparison with commercial products. Methods We produced eight common inhalant allergen SPT reagents using total extract (Prolagen): Dermatophagoides farinae, Dermatophagoides pteronyssinus, oak, ragweed, mugwort, Humulus japonicus pollens, as well as cat and dog allergens. We compared the newly developed reagents with three commercially available SPT reagents (Allergopharma, Hollister-Stier, Lofarma). We measured total protein concentrations, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), major allergen concentration, and biological allergen potencies measured by immunoglobulin E (IgE) immunoblotting and ImmunoCAP inhibition test. Results Diagnostic values of these SPT reagents were expressed as positivity rate and concordance rate of the results from ImmunoCAP allergen-specific IgE test in 94 allergic patients. In vitro analysis showed marked differences in protein concentrations, SDS-PAGE features, major allergen concentrations, and biological allergen potencies of four different SPT reagents. In vivo analysis showed that positive rates and concordance rates of Prolagen® SPT reagents were similar compared to the three commercial SPT reagents. Conclusion The newly developed Prolagen® inhalant SPT reagents are not inferior to the commercially available SPT reagents in allergy diagnosis. PMID:29573248

RELATIVE POTENCY RANKING FOR CHLOROPHENOLS

EPA Science Inventory

Recently the National Center for Environmental Assessment-Cincinnati completed a feasibility study for developing a toxicity related relative potency ranking scheme for chlorophenols. In this study it was concluded that a large data base exists pertaining to the relative toxicity...

Subliminal Affect Valence Words Change Conscious Mood Potency but Not Valence: Is This Evidence for Unconscious Valence Affect?

PubMed Central

Shevrin, Howard; Panksepp, Jaak; Brakel, Linda A. W.; Snodgrass, Michael

2012-01-01

Whether or not affect can be unconscious remains controversial. Research claiming to demonstrate unconscious affect fails to establish clearly unconscious stimulus conditions. The few investigations that have established unconscious conditions fail to rule out conscious affect changes. We report two studies in which unconscious stimulus conditions were met and conscious mood changes measured. The subliminal stimuli were positive and negative affect words presented at the objective detection threshold; conscious mood changes were measured with standard manikin valence, potency, and arousal scales. We found and replicated that unconscious emotional stimuli produced conscious mood changes on the potency scale but not on the valence scale. Were positive and negative affects aroused unconsciously, but reflected consciously in potency changes? Or were the valence words unconscious cognitive causes of conscious mood changes being activated without unconscious affect? A thought experiment is offered as a way to resolve this dilemma. PMID:24961258

Study on potency of municipal solid waste conversion into renewable energy by thermal incineration and bioconversion: case study of Medan city

NASA Astrophysics Data System (ADS)

Sarah, Maya; Misran, Erni

2018-03-01

Municipal solid waste (MSW) in Medan City is facing problems either with the quantity and management of MSW. Local authority only dumped approximately 73.9% MSW in the landfill over the years. Spontaneous phenomena of methane formation in dumping site indicates the potency of MSW conversion into energy by biochemical conversion. On the contrary, the presence of plastics, woods, papers, etc. in the MSW show the potency of MSW to be treated by thermal conversion. Both thermal incineration and anaerobic digestion may convert MSW Medan City into energy. This study evaluates potency of MSW conversion into renewable energy using proximate and ultimate analysis. Overall, MSW of Medan City has the opportunities to be converted into energy by both thermal and biochemical conversion with a special requirement such as pre-dry the MSW prior incineration process and degrade organic MSW in a bioreactor.

Peroxovanadium compounds: biological actions and mechanism of insulin-mimesis.

PubMed

Bevan, A P; Drake, P G; Yale, J F; Shaver, A; Posner, B I

When used alone, both vanadate and hydrogen peroxide (H2O2) are weakly insulin-mimetic, while in combination they are strongly synergistic due to the formation of aqueous peroxovanadium species pV(aq). Administration of these pV(aq) species leads to activation of the insulin receptor tyrosine kinase (IRK), autophosphorylation at tyrosine residues and inhibition of phosphotyrosine phosphatases (PTPs). We therefore undertook to synthesize a series of peroxovanadium (pV) compounds containing one or two peroxo anions, an oxo anion and an ancillary ligand in the inner co-ordination sphere of vanadium, whose properties and insulin-mimetic potencies could be assessed. These pV compounds were shown to be the most potent inhibitors of PTPs yet described. Their PTP inhibitory potency correlated with their capacity to stimulate IRK activity. Some pV compounds showed much greater potency as inhibitors of insulin receptor (IR) dephosphorylation than epidermal growth factor receptor (EGFR) dephosphorylation, implying relative specificity as PTP inhibitors. Replacement of vanadium with either molybdenum or tungsten resulted in equally potent inhibition of IR dephosphorylation. However IRK activation was reduced by greater than 80% suggesting that these compounds did not access intracellular PTPs. The insulin-like activity of these pV compounds were demonstrable in vivo. Intra venous (i.v.) administration of bpV(pic) and bpV(phen) resulted in the lowering of plasma glucose concentrations in normal rats in a dose dependent manner. The greater potency of bpV(pic) compared to bpV(phen) was explicable, in part, by the capacity of the former but not the latter to act on skeletal muscle as well as liver. Finally administration of bpV(phen) and insulin led to a synergism, where tyrosine phosphorylation of the IR beta-subunit increased by 20-fold and led to the appearance of four insulin-dependent in vivo substrates. The insulin-mimetic properties of the pV compounds raises the possibility for their use as insulin replacements in the management of diabetes mellitus.

Evaluation of B. subtilis SPB1 biosurfactants' potency for diesel-contaminated soil washing: optimization of oil desorption using Taguchi design.

PubMed

Mnif, Inès; Sahnoun, Rihab; Ellouze-Chaabouni, Semia; Ghribi, Dhouha

2014-01-01

Low solubility of certain hydrophobic soil contaminants limits remediation process. Surface-active compounds can improve the solubility and removal of hydrophobic compounds from contaminated soils and, consequently, their biodegradation. Hence, this paper aims to study desorption efficiency of oil from soil of SPB1 lipopeptide biosurfactant. The effect of different physicochemical parameters on desorption potency was assessed. Taguchi experimental design method was applied in order to enhance the desorption capacity and establish the best washing parameters. Mobilization potency was compared to those of chemical surfactants under the newly defined conditions. Better desorption capacity was obtained using 0.1% biosurfacatnt solution and the mobilization potency shows great tolerance to acidic and alkaline pH values and salinity. Results show an optimum value of oil removal from diesel-contaminated soil of about 87%. The optimum washing conditions for surfactant solution volume, biosurfactant concentration, agitation speed, temperature, and time were found to be 12 ml/g of soil, 0.1% biosurfactant, 200 rpm, 30 °C, and 24 h, respectively. The obtained results were compared to those of SDS and Tween 80 at the optimal conditions described above, and the study reveals an effectiveness of SPB1 biosurfactant comparable to the reported chemical emulsifiers. (1) The obtained findings suggest (a) the competence of Bacillus subtilis biosurfactant in promoting diesel desorption from soil towards chemical surfactants and (b) the applicability of this method in decontaminating crude oil-contaminated soil and, therefore, improving bioavailability of hydrophobic compounds. (2) The obtained findings also suggest the adequacy of Taguchi design in promoting process efficiency. Our findings suggest that preoptimized desorption process using microbial-derived emulsifier can contribute significantly to enhancement of hydrophobic pollutants' bioavailability. This study can be complemented with the investigation of potential role in improving the biodegradation of the diesel adsorbed to the soil.

Target organs in chronic bioassays of 533 chemical carcinogens

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

Gold, L.S.; Slone, T.H.; Manley, N.B.

1991-06-01

A compendium of carcinogenesis bioassay results organized by target organ is presented for 533 chemicals that are carcinogenic in at least one species. This compendium is based primarily on experiments in rats or mice; results in hamsters, nonhuman primates, and dogs are also reported. The compendium can be used to identify chemicals that induce tumors at particular sites, and to determine whether target sites are the same for chemicals positive in more than one species. The Carcinogenic Potency Database (CPDB), which includes results of 3969 experiments, is used in the analysis. The published CPDB includes details on each test, andmore » literature references. Chemical carcinogens are reported for 35 different target organs in rats or mice. More than 80% of the carcinogens in each of these species are positive in at least one of the 8 most frequent target sites; liver, lung, mammary gland, stomach, vascular system, kidney, hematopoietic system, and urinary bladder. An analysis is presented of how well one can predict the carcinogenic response in mice from results in rats, or vice versa. Among chemicals tested in both species, 76% of rat carcinogens are positive in mice, and 71% of mouse carcinogens are positive in rats. Prediction is less accurate to the same target site: 52% of rat carcinogens are positive in the same site in mice, and 48% of mouse carcinogens are positive in the same site in rats. The liver is the most frequent site in common between rats and mice.« less

Antimicrobial Cream Formulated with Supercritical Carbon Dioxide Extract of Tuberose Flowers Arrests Growth of Staphylococcus aureus.

PubMed

Ghosh, Probir Kumar; Bhattacharjee, Paramita; Das, Satadal

2016-01-01

Antimicrobial potency of herbal extracts is well known. The review of patents and research articles revealed that several herbal extracts have been employed in the formulation of topical products such as creams, exclusive of the cream reported in the present study. 0ur previous study has established antimicrobial potency of supercritical carbon dioxide extracts of tuberose flowers, better known for its sweet fragrance. The present work focuses on formulating a topical antimicrobial herbal cream with methyl eugenol (principal antimicrobial compound) rich - supercritical carbon dioxide extract of tuberose flowers, having good combination of phytochemical and antimicrobial potencies. Supercritical carbon dioxide parameters such as temperature, pressure and time were optimized using full factorial experimental design to obtain methyl eugenol-rich extracts. A cream was formulated using the extract having the best combination of phytochemical and antimicrobial potencies and was assayed further for in vitro antimicrobial potency; physiochemical and sensory properties. Two commercial antimicrobial cream samples were used as reference samples in the study. The extract obtained at 40°C, 10 MPa, 135 min at 1 L min-1 flow rate of gaseous C02 showed the best combination of phytochemical and antimicrobial potencies and was used for formulation of herbal creams. The cream formulated with 5% w/w of extract arrested growth of the common human skin pathogen Staphylococcus aureus and showed stable physiochemical properties and high sensory appeal for a year. The cream could be considered as a 'finished herbal product&' in compliance with the World Health 0rganization guidelines.

Role of Homologous Fc Fragment in the Potency and Efficacy of Anti-Botulinum Antibody Preparations.

PubMed

Torgeman, Amram; Ozeri, Eyal; Ben David, Alon; Diamant, Eran; Rosen, Osnat; Schwartz, Arieh; Barnea, Ada; Makovitzki, Arik; Mimran, Avishai; Zichel, Ran

2017-05-29

The only approved treatment for botulism relies on passive immunity which is mostly based on antibody preparations collected from hyper-immune horses. The IgG Fc fragment is commonly removed from these heterologous preparations to reduce the incidence of hyper-sensitivity reactions. New-generation therapies entering the pipeline are based on a combination of humanized monoclonal antibodies (MAbs), which exhibit improved safety and pharmacokinetics. In the current study, a systematic and quantitative approach was applied to measure the direct contribution of homologous Fc to the potency of monoclonal and polyclonal antitoxin preparations in mice. Homologous Fc increased the potency of three individual anti-botulinum toxin MAbs by up to one order of magnitude. Moreover, Fc fragment removal almost completely abolished the synergistic potency obtained from a combined preparation of these three MAbs. The MAb mixture neutralized a 400-mouse median lethal dose (MsLD50) of botulinum toxin, whereas the F(ab')2 combination failed to neutralize 10 MsLD50 of botulinum toxin. Notably, increased avidity did not compensate for this phenomenon, as a polyclonal, hyper-immune, homologous preparation lost 90% of its potency as well upon Fc removal. Finally, the addition of homologous Fc arms to a heterologous pharmaceutical anti-botulinum toxin polyclonal horse F(ab')2 preparation improved its efficacy when administered to intoxicated symptomatic mice. Our study extends the aspects by which switching from animal-based to human-based antitoxins will improve not only the safety but also the potency and efficacy of passive immunity against toxins.

Plasma metabolomic profiles of breast cancer patients after short-term limonene intervention

PubMed Central

Miller, Jessica A.; Pappan, Kirk; Thompson, Patricia A.; Want, Elizabeth J.; Siskos, Alexandros; Keun, Hector C.; Wulff, Jacob; Hu, Chengcheng; Lang, Julie E.; Chow, H-H. Sherry

2014-01-01

Limonene is a lipophilic monoterpene found in high levels in citrus peel. Limonene demonstrates anti-cancer properties in preclinical models with effects on multiple cellular targets at varying potency. While of interest as a cancer chemopreventive, the biological activity of limonene in humans is poorly understood. We conducted metabolite profiling in 39 paired (pre/post-intervention) plasma samples from early-stage breast cancer patients receiving limonene treatment (2 g QD) before surgical resection of their tumor. Metabolite profiling was conducted using ultra-performance liquid chromatography (UPLC) coupled to a linear trap quadrupole (LTQ) system and gas chromatography mass spectrometry (GC-MS). Metabolites were identified by comparison of ion features in samples to a standard reference library. Pathway-based interpretation was conducted using the human metabolome database (HMDB) and the MetaCyc database. Of the 397 named metabolites identified, 72 changed significantly with limonene intervention. Class-based changes included significant decreases in adrenal steroids (P’s<0.01), and significant increases in bile acids (P’s≤0.05) and multiple collagen breakdown products (P’s<0.001). The pattern of changes also suggested alterations in glucose metabolism. There were 47 metabolites whose change with intervention was significantly correlated to a decrease in cyclin D1, a cell cycle regulatory protein, in patient tumor tissues (P’s≤0.05). Here, oral administration of limonene resulted in significant changes in several metabolic pathways. Further, pathway-based changes were related to the change in tissue level cyclin D1 expression. Future controlled clinical trials with limonene are necessary to determine the potential role and mechanisms of limonene in the breast cancer prevention setting. PMID:25388013

Small difference in carcinogenic potency between GBP nanomaterials and GBP micromaterials.

PubMed

Gebel, Thomas

2012-07-01

Materials that can be described as respirable granular biodurable particles without known significant specific toxicity (GBP) show a common mode of toxicological action that is characterized by inflammation and carcinogenicity in chronic inhalation studies in the rat. This study was carried out to compare the carcinogenic potency of GBP nanomaterials (primary particle diameter 1-100 nm) to GBP micromaterials (primary particle diameter >100 nm) in a pooled approach. For this purpose, the positive GBP rat inhalation carcinogenicity studies have been evaluated. Inhalation studies on diesel engine emissions have also been included due to the fact that the mode of carcinogenic action is assumed to be the same. As it is currently not clear which dose metrics may best explain carcinogenic potency, different metrics have been considered. Cumulative exposure concentrations related to mass, surface area, and primary particle volume have been included as well as cumulative lung burden metrics related to mass, surface area, and primary particle volume. In total, 36 comparisons have been conducted. Including all dose metrics, GBP nanomaterials were 1.33- to 1.69-fold (mean values) and 1.88- to 3.54-fold (median values) more potent with respect to carcinogenicity than GBP micromaterials, respectively. Nine of these 36 comparisons showed statistical significance (p < 0.05, U test), all of which related to dose metrics based on particle mass. The maximum comparative potency factor obtained for one of these 9 dose metric comparisons based on particle mass was 4.71. The studies with diesel engine emissions did not have a major impact on the potency comparison. The average duration of the carcinogenicity studies with GBP nanomaterials was 4 months longer (median values 30 vs. 26 months) than the studies with GBP micromaterials, respectively. Tumor rates increase with age and lung tumors in the rat induced by GBP materials are known to appear late, that is, mainly after study durations longer than 24 months. Taking the different study durations into account, the real potency differences were estimated to be twofold lower than the relative potency factors identified. In conclusion, the chronic rat inhalation studies with GBP materials indicate that the difference in carcinogenic potency between GBP nanomaterials and GBP micromaterials is low can be described by a factor of 2-2.5 referring to the dose metrics mass concentration.

The Nucleation Potency of In Situ-Formed Oxides in Liquid Iron

NASA Astrophysics Data System (ADS)

Xu, Mingqin; Wang, Lu; Lu, Wenquan; Zeng, Long; Nadendla, Hari-Babu; Wang, Yun; Li, Jun; Hu, Qiaodan; Xia, Mingxu; Li, Jianguo

2018-03-01

The nucleation potency of iron oxides was verified experimentally through nucleation undercooling of liquid iron using aerodynamic levitation technology for minimized container contaminations. Steady undercooling values were subsequently obtained from multiple melting and freezing thermal cycles, with the average undercooling values of 223 K ± 3 K and 75 K ± 6 K (223 °C ± 3 °C and 75 °C ± 6 °C) for FeO-contained liquid and Fe3O4-contained liquid, respectively. The statistical results showed a negligible difference in the sizes and numbers of particles between FeO and Fe3O4 particles, indicating that the nucleation potency difference is attributed to the nature of nucleants rather than particle size or numbers. Furthermore, high-resolution transmission electron microscopy analysis showed that the potential nucleation interfaces can be assumed as { 1 1 0}_{{δ {{-Fe}}}} //( 0 0\\bar{2})_{FeO} and { 1 1 2}_{{δ {{-Fe}}}} //(\\bar{2} 0 2 )_{{{Fe}3 {O}4 }} , based on the detected exposed crystal planes of the oxide particles. Both the interfaces have relatively large values of lattice misfit, consistent with the experimentally measured undercooling based on Turnbull's lattice matching theory.

Structure-Activity Relationship Studies on a Macrocyclic Agouti-Related Protein (AGRP) Scaffold Reveal Agouti Signaling Protein (ASP) Residue Substitutions Maintain Melanocortin-4 Receptor Antagonist Potency and Result in Inverse Agonist Pharmacology at the Melanocortin-5 Receptor.

PubMed

Ericson, Mark D; Freeman, Katie T; Schnell, Sathya M; Fleming, Katlyn A; Haskell-Luevano, Carrie

2017-10-12

The melanocortin system consists of five reported receptors, agonists from the proopiomelanocortin gene transcript, and two antagonists, agouti-signaling protein (ASP) and agouti-related protein (AGRP). For both ASP and AGRP, the hypothesized Arg-Phe-Phe pharmacophores are on exposed β-hairpin loops. In this study, the Asn and Ala positions of a reported AGRP macrocyclic scaffold (c[Pro-Arg-Phe-Phe-Asn-Ala-Phe-DPro]) were explored with 14-compound and 8-compound libraries, respectively, to generate more potent, selective melanocortin receptor antagonists. Substituting diaminopropionic acid (Dap), DDap, and His at the Asn position yielded potent MC4R ligands, while replacing Ala with Ser maintained MC4R potency. Since these substitutions correlate to ASP loop residues, an additional Phe to Ala substitution was synthesized and observed to maintain MC4R potency. Seventeen compounds also possessed inverse agonist activity at the MC5R, the first report of this pharmacology. These findings are useful in developing molecular probes to study negative energy balance conditions and unidentified functions of the MC5R.

Enterocin A Mutants Identified by Saturation Mutagenesis Enhance Potency Towards Vancomycin-Resistant Enterococci

PubMed Central

McClintock, Maria K.; Kaznessis, Yiannis N.; Hackel, Benjamin J.

2016-01-01

Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13±3- and 18±4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. PMID:26191783

Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin-resistant Enterococci.

PubMed

McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J

2016-02-01

Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.

Design, Synthesis, and Biological Evaluation of Novel Type I1/2 p38α MAP Kinase Inhibitors with Excellent Selectivity, High Potency, and Prolonged Target Residence Time by Interfering with the R-Spine.

PubMed

Walter, Niklas M; Wentsch, Heike K; Bührmann, Mike; Bauer, Silke M; Döring, Eva; Mayer-Wrangowski, Svenja; Sievers-Engler, Adrian; Willemsen-Seegers, Nicole; Zaman, Guido; Buijsman, Rogier; Lämmerhofer, Michael; Rauh, Daniel; Laufer, Stefan A

2017-10-12

We recently reported 1a (skepinone-L) as a type I p38α MAP kinase inhibitor with high potency and excellent selectivity in vitro and in vivo. However, as a type I inhibitor, it is entirely ATP-competitive and shows just a moderate residence time. Thus, the scope was to develop a new class of advanced compounds maintaining the structural binding features of skepinone-L scaffold like inducing a glycine flip at the hinge region and occupying both hydrophobic regions I and II. Extending this scaffold with suitable residues resulted in an interference with the kinase's R-Spine. By synthesizing 69 compounds, we could significantly prolong the target residence time with one example to 3663 s, along with an excellent selectivity score of 0.006 and an outstanding potency of 1.0 nM. This new binding mode was validated by cocrystallization, showing all binding interactions typifying type I 1 / 2 binding. Moreover, microsomal studies showed convenient metabolic stability of the most potent, herein reported representatives.

Effect of the chelation of metal cation on the antioxidant activity of chondroitin sulfates.

PubMed

Ajisaka, Katsumi; Oyanagi, Yutaka; Miyazaki, Tatsuo; Suzuki, Yasuhiro

2016-06-01

The antioxidant potencies of chondroitin sulfates (CSs) from shark cartilage, salmon cartilage, bovine trachea, and porcine intestinal mucosa were compared by three representative methods for the measurement of the antioxidant activity; DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity. CSs from salmon cartilage and bovine trachea showed higher potency in comparison with CSs from shark cartilage and porcine intestinal mucosa. Next, CS from salmon cartilage chelating with Ca(2+), Mg(2+), Mn(2+), or Zn(2+) were prepared, and their antioxidant potencies were compared. CS chelating with Ca(2+) or Mg(2+) ions showed rather decreased DPPH radical scavenging activity in comparison with CS of H(+) form. In contrast, CS chelating with Ca(2+) or Mg(2+) ion showed remarkably enhanced superoxide radical scavenging activity than CS of H(+) or Na(+) form. Moreover, CS chelating with divalent metal ions, Ca(2+), Mg(2+), Mn(2+), or Zn(2+), showed noticeably higher hydroxyl radical scavenging activity than CS of H(+) or Na(+) form. The present results revealed that the scavenging activities of, at least, superoxide radical and hydroxyl radical were enhanced by the chelation with divalent metal ions.

Structure-activity relationship of C-terminal hexa- and heptapeptide substance P antagonists as studied in the guinea-pig ileum.

PubMed

Hörig, J; Schultheiss, H

1984-10-01

The 14 C-terminal heptapeptide analogues and one hexapeptide analogue of substance P (SP) were synthesized on the basis of the SP antagonist [D-Pro2,D-Trp7,9]SP-(1-11). They were tested in the guinea-pig ileum preparation for spasmogenic and antagonistic activities. All analogues except two had antagonistic activity. Spasmogenic activity was observed in three heptapeptide SP antagonists: [Arg5,D-Trp7,D-pCl-Phe9]SP-(5-11), [Arg5,D-Trp7,9,p-Cl-Phe8]SP-(5-11) and [Arg5,D-Trp7,9,Nle11]SP-(5-11). However, this effect became greatly reduced upon successive applications in almost all ileum preparations. For antagonistic potency D-Trp turned out to be of greater importance in position 9 than in position 7 of the SP molecule. The presence of a free amino group at the N-terminal of the peptide was also of significant importance for antagonistic potency. Exchange of Met11 for Nle resulted in a considerable increase of antagonistic potency, while other substitutions in this position were ineffective or slightly reduced the antagonistic effect in the ileum preparation.

Biosorption of Congo Red from aqueous solution by Bacillus weihenstephanensis RI12; effect of SPB1 biosurfactant addition on biodecolorization potency.

PubMed

Mnif, Inès; Fendri, Raouia; Ghribi, Dhouha

2015-01-01

Bacillus weihenstephanensis RI12, isolated from hydrocarbon contaminated soil, was assessed for Congo Red bio-treatment potency. Results suggested the potential of this bacterium for use in effective treatment of Congo Red contaminated wastewaters under shaking conditions at acidic and neutral pH value. The strain could tolerate higher doses of dyes as it could decolorize up to 1,000 mg/l of Congo Red. When used as microbial surfactant to enhance Congo Red biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized the decolorization efficiency at an optimal concentration of biosurfactant of about 0.075%. Studies ensured that Congo Red removal by this strain could be due to an adsorption phenomena. Germination potencies of tomato seeds using the treated dyes under different conditions showed the efficient biotreatment of the azo dye Congo Red especially with the addition of SPB1 biosurfactant. To conclude, the addition of SPB1 bioemulsifier reduced energy costs by reducing the effective decolorization period; the biosurfactant stimulated bacterial decolorization method may provide a highly efficient, inexpensive and time-saving procedure in the treatment of textile effluents.

Alcohol action on a neuronal membrane receptor: evidence for a direct interaction with the receptor protein.

PubMed Central

Li, C; Peoples, R W; Weight, F F

1994-01-01

For almost a century, alcohols have been thought to produce their effects by actions on the membrane lipids of central nervous system neurons--the well known "lipid theory" of alcohol action. The rationale for this theory is the correlation of potency with oil/water or membrane/buffer partition coefficient. Although a number of recent studies have shown that alcohols can affect the function of certain neuronal neurotransmitter receptors, there is no evidence that the alcohols interact directly with these membrane proteins. In the present study, we report that inhibition of a neuronal neurotransmitter receptor, an ATP-gated ion channel, by a series of alcohols exhibits a distinct cutoff effect. For alcohols with a molecular volume of < or = 42.2 ml/mol, potency for inhibiting ATP-activated current was correlated with lipid solubility (order of potency: 1-propanol = trifluoroethanol > monochloroethanol > ethanol > methanol). However, despite increased lipid solubility, alcohols with a molecular volume of > or = 46.1 ml/mol (1-butanol, 1-pentanol, trichloroethanol, and dichloroethanol) were without effect on the ATP-activated current. The results suggest that alcohols inhibit the function of this neurotransmitter receptor by interacting with a small hydrophobic pocket on the receptor protein. PMID:8058780

3D-QSAR studies on the inhibitory activity of trimethoprim analogues against Escherichia coli dihydrofolate reductase.

PubMed

Vijayaraj, Ramadoss; Devi, Mekapothula Lakshmi Vasavi; Subramanian, Venkatesan; Chattaraj, Pratim Kumar

2012-06-01

Three-dimensional quantitative structure activity relationship (3D-QSAR) study has been carried out on the Escherichia coli DHFR inhibitors 2,4-diamino-5-(substituted-benzyl)pyrimidine derivatives to understand the structural features responsible for the improved potency. To construct highly predictive 3D-QSAR models, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were used. The predicted models show statistically significant cross-validated and non-cross-validated correlation coefficient of r2 CV and r2 nCV, respectively. The final 3D-QSAR models were validated using structurally diverse test set compounds. Analysis of the contour maps generated from CoMFA and CoMSIA methods reveals that the substitution of electronegative groups at the first and second position along with electropositive group at the third position of R2 substitution significantly increases the potency of the derivatives. The results obtained from the CoMFA and CoMSIA study delineate the substituents on the trimethoprim analogues responsible for the enhanced potency and also provide valuable directions for the design of new trimethoprim analogues with improved affinity. © 2012 John Wiley & Sons A/S.

Patients with Parkinson's disease display a dopamine therapy related negative bias and an enlarged range in emotional responses to facial emotional stimuli.

PubMed

Lundqvist, Daniel; Svärd, Joakim; Michelgård Palmquist, Åsa; Fischer, Håkan; Svenningsson, Per

2017-09-01

The literature on emotional processing in Parkinson's disease (PD) patients shows mixed results. This may be because of various methodological and/or patient-related differences, such as failing to adjust for cognitive functioning, depression, and/or mood. In the current study, we tested PD patients and healthy controls (HCs) using emotional stimuli across a variety of tasks, including visual search, short-term memory (STM), categorical perception, and emotional stimulus rating. The PD and HC groups were matched on cognitive ability, depression, and mood. We also explored possible relationships between task results and antiparkinsonian treatment effects, as measured by levodopa equivalent dosages (LED), in the PD group. The results show that PD patients use a larger emotional range compared with HCs when reporting their impression of emotional faces on rated emotional valence, arousal, and potency. The results also show that dopaminergic therapy was correlated with stimulus rating results such that PD patients with higher LED scores rated negative faces as less arousing, less negative, and less powerful. Finally, results also show that PD patients display a general slowing effect in the visual search tasks compared with HCs, indicating overall slowed responses. There were no group differences observed in the STM or categorical perception tasks. Our results indicate a relationship between emotional responses, PD, and dopaminergic therapy, in which PD per se is associated with stronger emotional responses, whereas LED levels are negatively correlated with the strength of emotional responses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Potential of Fruit Wastes as Natural Resources of Bioactive Compounds

PubMed Central

Deng, Gui-Fang; Shen, Chen; Xu, Xiang-Rong; Kuang, Ru-Dan; Guo, Ya-Jun; Zeng, Li-Shan; Gao, Li-Li; Lin, Xi; Xie, Jie-Feng; Xia, En-Qin; Li, Sha; Wu, Shan; Chen, Feng; Ling, Wen-Hua; Li, Hua-Bin

2012-01-01

Fruit wastes are one of the main sources of municipal waste. In order to explore the potential of fruit wastes as natural resources of bioactive compounds, the antioxidant potency and total phenolic contents (TPC) of lipophilic and hydrophilic components in wastes (peel and seed) of 50 fruits were systematically evaluated. The results showed that different fruit residues had diverse antioxidant potency and the variation was very large. Furthermore, the main bioactive compounds were identified and quantified, and catechin, cyanidin 3-glucoside, epicatechin, galangin, gallic acid, homogentisic acid, kaempferol, and chlorogenic acid were widely found in these residues. Especially, the values of ferric-reducing antioxidant power (FRAP), trolox equivalent antioxidant capacity (TEAC) and TPC in the residues were higher than in pulps. The results showed that fruit residues could be inexpensive and readily available resources of bioactive compounds for use in the food and pharmaceutical industries. PMID:22942704

Potential of fruit wastes as natural resources of bioactive compounds.

PubMed

Deng, Gui-Fang; Shen, Chen; Xu, Xiang-Rong; Kuang, Ru-Dan; Guo, Ya-Jun; Zeng, Li-Shan; Gao, Li-Li; Lin, Xi; Xie, Jie-Feng; Xia, En-Qin; Li, Sha; Wu, Shan; Chen, Feng; Ling, Wen-Hua; Li, Hua-Bin

2012-01-01

Fruit wastes are one of the main sources of municipal waste. In order to explore the potential of fruit wastes as natural resources of bioactive compounds, the antioxidant potency and total phenolic contents (TPC) of lipophilic and hydrophilic components in wastes (peel and seed) of 50 fruits were systematically evaluated. The results showed that different fruit residues had diverse antioxidant potency and the variation was very large. Furthermore, the main bioactive compounds were identified and quantified, and catechin, cyanidin 3-glucoside, epicatechin, galangin, gallic acid, homogentisic acid, kaempferol, and chlorogenic acid were widely found in these residues. Especially, the values of ferric-reducing antioxidant power (FRAP), trolox equivalent antioxidant capacity (TEAC) and TPC in the residues were higher than in pulps. The results showed that fruit residues could be inexpensive and readily available resources of bioactive compounds for use in the food and pharmaceutical industries.

Pyridylthiazole-based ureas as inhibitors of Rho associated protein kinases (ROCK1 and 2)†

PubMed Central

Pireddu, Roberta; Forinash, Kara D.; Sun, Nan N.; Martin, Mathew P.; Sung, Shen-Shu; Alexander, Brian; Zhu, Jin-Yi; Guida, Wayne C.; Schönbrunn, Ernst; Sebti, Saïd M.; Lawrence, Nicholas J.

2012-01-01

Potent ROCK inhibitors of a new class of 1-benzyl-3-(4-pyridylthiazol-2-yl)ureas have been identified. Remarkable differences in activity were observed for ureas bearing a benzylic stereogenic center. Derivatives with hydroxy, methoxy and amino groups at the meta position of the phenyl ring give rise to the most potent inhibitors (low nM). Substitutions at the para position result in substantial loss of potency. Changes at the benzylic position are tolerated resulting in significant potency in the case of methyl and methylenehydroxy groups. X-Ray crystallography was used to establish the binding mode of this class of inhibitors and provides an explanation for the observed differences of the enantiomer series. Potent inhibition of ROCK in human lung cancer cells was shown by suppression of the levels of phosphorylation of the ROCK substrate MYPT-1. PMID:23275831

An analysis of the characteristics of Indonesian industrial sectors: 2005-2010

NASA Astrophysics Data System (ADS)

Zuhdi, Ubaidillah

2017-10-01

The purpose of the current study is to analyze the characteristics of Indonesian industrial sectors from 2005 through 2010. The study employs the analysis instruments from the Input-Output (IO) analysis, namely the indices of the power of dispersion, and the sensitivity of dispersion. For 2005 and 2010, the study focuses on nine and seventeen industries, respectively. The results show that industry 3, manufacturing, placed the quadrant I on the analysis period. The fact shows that, from 2005 through 2010, the industry had a strong influence on the Indonesian economic activities, and received high impacts from the external aspects. In other words, the industry has great potency for the Indonesian economy. From the results one can also see that sector 4, electricity and gas, included in the quadrant I in 2010. This fact explains that the sector has also great potency for the economic activities of Indonesia. Thus, the Indonesian government should prioritize the industries development.

Fertility of male rats treated with 15(S)-15-methyl prostaglandin F2 alpha methyl ester-containing silastic implants.

PubMed

Kimball, F A; Frielink, R D; Porteus, S E

1978-01-01

Male Spraque-Dawley rats receiving implants of silicone rubber discs containing 1% or 2% 15(S)-15-methyl prostaglandin F2 alpha methyl ester (15-Me-PGF 2 alpha) or no prostaglandin were tested in successive breeding trials for potency and fertility. One week after implantation, discs containing 1% 15-Me-PGF2 alpha reduced potency and fertility, which returned 2 weeks after implantation. Animals receiving implants of the 2% discs were apparently impotent the 1st week following implantation; potency returned before full fertility returned 11 weeks after implantation.

A new series of highly potent growth hormone-releasing peptides derived from ipamorelin.

PubMed

Ankersen, M; Johansen, N L; Madsen, K; Hansen, B S; Raun, K; Nielsen, K K; Thogersen, H; Hansen, T K; Peschke, B; Lau, J; Lundt, B F; Andersen, P H

1998-09-10

A new series of GH secretagogues derived from ipamorelin is described. In an attempt to obtain oral bioavailability, by reducing the size and the number of potential hydrogen-bonding sites of the compounds, a strategy using the peptidomimetic fragment 3-(aminomethyl)benzoic acid and sequential backbone N-methylations was applied. Several compounds from this series release GH with high in vitro potency and efficacy in a rat pituitary cell assay and high in vivo potency and efficacy in anesthetized rats. The tetrapeptide NNC 26-0235 (3-(aminomethyl)benzoyl-D-2Nal-N-Me-D-Phe-Lys-NH2) shows, following iv administration, comparable in vivo potency to ipamorelin, GHRP-2, and GHRP-6 with an ED50 in swine at 2 nmol/kg. NNC 26-0235 demonstrated a 10% oral bioavailability in dogs, and NNC 26-0235 and ipamorelin were able to increase basal GH level by more than 10-fold after oral administration of a dose of 1.8 and 2.7 mg/kg, respectively. The tripeptide NNC 26-0323 (3-(aminomethyl)benzoic acid-N-Me-D-2Nal-N-Me-D-Phe-ol) which showed moderate in vitro potency but lacked in vivo potency demonstrated a 20% oral bioavailability in rats.

Identification of Thyroid Receptor Ant/Agonists in Water Sources Using Mass Balance Analysis and Monte Carlo Simulation

PubMed Central

Shi, Wei; Wei, Si; Hu, Xin-xin; Hu, Guan-jiu; Chen, Cu-lan; Wang, Xin-ru; Giesy, John P.; Yu, Hong-xia

2013-01-01

Some synthetic chemicals, which have been shown to disrupt thyroid hormone (TH) function, have been detected in surface waters and people have the potential to be exposed through water-drinking. Here, the presence of thyroid-active chemicals and their toxic potential in drinking water sources in Yangtze River Delta were investigated by use of instrumental analysis combined with cell-based reporter gene assay. A novel approach was developed to use Monte Carlo simulation, for evaluation of the potential risks of measured concentrations of TH agonists and antagonists and to determine the major contributors to observed thyroid receptor (TR) antagonist potency. None of the extracts exhibited TR agonist potency, while 12 of 14 water samples exhibited TR antagonistic potency. The most probable observed antagonist equivalents ranged from 1.4 to 5.6 µg di-n-butyl phthalate (DNBP)/L, which posed potential risk in water sources. Based on Monte Carlo simulation related mass balance analysis, DNBP accounted for 64.4% for the entire observed antagonist toxic unit in water sources, while diisobutyl phthalate (DIBP), di-n-octyl phthalate (DNOP) and di-2-ethylhexyl phthalate (DEHP) also contributed. The most probable observed equivalent and most probable relative potency (REP) derived from Monte Carlo simulation is useful for potency comparison and responsible chemicals screening. PMID:24204563

Opportunities and strategies to further reduce animal use for Leptospira vaccine potency testing.

PubMed

Walker, A; Srinivas, G B

2013-09-01

Hamsters are routinely infected with virulent Leptospira for two purposes in the regulation of biologics: the performance of Codified potency tests and maintenance of challenge culture for the Codified potency tests. Options for reducing animal use in these processes were explored in a plenary lecture at the "International Workshop on Alternative Methods for Leptospira Vaccine Potency Testing: State of the Science and the Way Forward" held at the Center for Veterinary Biologics in September 2012. The use of validated in vitro potency assays such as those developed by the U.S. Department of Agriculture for Leptospira (L.) canicola, Leptospira grippotyphosa, Leptospira pomona, and Leptospira icterohaemorrhagiae rather than the Codified hamster vaccination-challenge assay was encouraged. Alternatives such as reduced animal numbers in the hamster vaccination-challenge testing were considered for problematic situations. Specifically, the merits of sharing challenge controls, reducing group sizes, and eliminating animals for concurrent challenge dose titration were assessed. Options for maintaining virulent, stable cultures without serial passage through hamsters or with decreased hamster use were also discussed. The maintenance of virulent Leptospira without the use of live animals is especially difficult since a reliable means to maintain virulence after multiple in vitro passages has not yet been identified. Published by Elsevier Ltd.

Development of a new benzophenone-diketopiperazine-type potent antimicrotubule agent possessing a 2-pyridine structure.

PubMed

Hayashi, Yoshiki; Takeno, Haruka; Chinen, Takumi; Muguruma, Kyohei; Okuyama, Kohei; Taguchi, Akihiro; Takayama, Kentaro; Yakushiji, Fumika; Miura, Masahiko; Usui, Takeo; Hayashi, Yoshio

2014-10-09

A new benzophenone-diketopiperazine-type potent antimicrotubule agent was developed by modifying the structure of the clinical candidate plinabulin (1). Although the right-hand imidazole ring with a branched alkyl chain at the 5-position in 1 was critical for the potency of the antimicrotubule activity, we successfully substituted this moiety with a simpler 2-pyridyl structure by converting the left-hand ring from a phenyl to a benzophenone structure without decreasing the potency. The resultant compound 6b (KPU-300) exhibited a potent cytotoxicity, with an IC50 value of 7.0 nM against HT-29 cells, by strongly binding to tubulin (K d = 1.3 μM) and inducing microtubule depolymerization.

Biarylmethoxy Nicotinamides As Novel and Specific Inhibitors of Mycobacterium tuberculosis.

PubMed

Kedari, Chaitanya Kumar; Roy Choudhury, Nilanjana; Sharma, Sreevalli; Kaur, Parvinder; Guptha, Supreeth; Panda, Manoranjan; Mukerjee, Kakoli; Ramachandran, Vasanthi; Bandodkar, Balachandra; Ramachandran, Sreekanth; Tantry, Subramanyam J

2014-05-08

A whole cell based screening effort on a focused library from corporate collection resulted in the identification of biarylmethoxy nicotinamides as novel inhibitors of M. tuberculosis (Mtu) H37Rv. The series exhibited tangible structure-activity relationships, and during hit to lead exploration, a cellular potency of 100 nM was achieved, which is an improvement of >200-fold from the starting point. The series is very specific to Mtu and noncytotoxic up to 250 μM as measured in the mammalian cell line THP-1 based cytotoxicity assay. This compound class retains its potency on several drug sensitive and single drug resistant clinical isolates, which indicate that the compounds could be acting through a novel mode of action.

Collaborative study for the establishment of the 4(th) International Standard for Streptomycin.

PubMed

Jorajuria, S; Raphalen, C; Dujardin, V; Daas, A

2015-01-01

An international collaborative study was organised to establish the 4(th) World Health Organization (WHO) International Standard (IS) for Streptomycin. Fourteen laboratories from different countries participated. Potencies of the candidate material were estimated by microbiological assays with sensitive micro-organisms. To ensure continuity between consecutive batches, the 3(rd) IS for Streptomycin was used as a reference. Based on the results of the study, the 4(th) IS for Streptomycin was adopted at the meeting of the WHO Expert Committee for Biological Standardization (ECBS) in 2015 with an assigned potency of 76 000 International Units (IU) per vial. The 4(th) IS for Streptomycin is available from the European Directorate for the Quality of Medicines & HealthCare (EDQM).

Exploring the Effects on Lipid Bilayer Induced by Noble Gases via Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Chen, Junlang; Chen, Liang; Wang, Yu; Wang, Xiaogang; Zeng, Songwei

2015-11-01

Noble gases seem to have no significant effect on the anesthetic targets due to their simple, spherical shape. However, xenon has strong narcotic efficacy and can be used clinically, while other noble gases cannot. The mechanism remains unclear. Here, we performed molecular dynamics simulations on phospholipid bilayers with four kinds of noble gases to elucidate the difference of their effects on the membrane. Our results showed that the sequence of effects on membrane exerted by noble gases from weak to strong was Ne, Ar, Kr and Xe, the same order as their relative narcotic potencies as well as their lipid/water partition percentages. Compared with the other three kinds of noble gases, more xenon molecules were distributed between the lipid tails and headgroups, resulting in membrane’s lateral expansion and lipid tail disorder. It may contribute to xenon’s strong anesthetic potency. The results are well consistent with the membrane mediated mechanism of general anesthesia.

An epidermal equivalent assay for identification and ranking potency of contact sensitizers

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

Gibbs, Susan, E-mail: S.Gibbs@VUMC.nl; Corsini, Emanuela; Spiekstra, Sander W.

2013-10-15

The purpose of this study was to explore the possibility of combining the epidermal equivalent (EE) potency assay with the assay which assesses release of interleukin-18 (IL-18) to provide a single test for identification and classification of skin sensitizing chemicals, including chemicals of low water solubility or stability. A protocol was developed using different 3D-epidermal models including in house VUMC model, epiCS® (previously EST1000™), MatTek EpiDerm™ and SkinEthic™ RHE and also the impact of different vehicles (acetone:olive oil 4:1, 1% DMSO, ethanol, water) was investigated. Following topical exposure for 24 h to 17 contact allergens and 13 non-sensitizers a robustmore » increase in IL-18 release was observed only after exposure to contact allergens. A putative prediction model is proposed from data obtained from two laboratories yielding 95% accuracy. Correlating the in vitro EE sensitizer potency data, which assesses the chemical concentration which results in 50% cytotoxicity (EE-EC{sub 50}) with human and animal data showed a superior correlation with human DSA{sub 05} (μg/cm{sup 2}) data (Spearman r = 0.8500; P value (two-tailed) = 0.0061) compared to LLNA data (Spearman r = 0.5968; P value (two-tailed) = 0.0542). DSA{sub 05} = induction dose per skin area that produces a positive response in 5% of the tested population Also a good correlation was observed for release of IL-18 (SI-2) into culture supernatants with human DSA{sub 05} data (Spearman r = 0.8333; P value (two-tailed) = 0.0154). This easily transferable human in vitro assay appears to be very promising, but additional testing of a larger chemical set with the different EE models is required to fully evaluate the utility of this assay and to establish a definitive prediction model. - Highlights: • A potential epidermal equivalent assay to label and classify sensitizers • Il-18 release distinguishes sensitizers from non sensitizers • IL-18 release can rank sensitizer potency • EC50 (chemical concentration causing 50% decrease in cell viability) ranks potency • In vitro: human DSA{sub 05} correlation is better than in vitro: LLNA correlation.« less

Study of the effect of thiols on the vasodilatory potency of S-nitrosothiols by using a modified aortic ring assay

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

Giustarini, Daniela, E-mail: giustarini@unisi.it; Tsikas, Dimitrios, E-mail: tsikas.dimitros@mh-hannover.de; Rossi, Ranieri, E-mail: ranieri@unisi.it

2011-10-15

Both low-molecular-mass thiols (LMM-SH) and protein thiols (P-SH) can modulate the biological activity of S-nitrosothiols (RSNO) via S-transnitrosation reactions. It has been difficult to evaluate the entity of this effect in blood circulation by in vitro assays with isolated aorta rings so far, because media rich in proteins cannot be used due to the foaming as a consequence of the needed gas bubbling. We have modified the original apparatus for organ bioassay in order to minimize foaming and to increase analytical performance. By using this modified bioassay we investigated the vasodilatory potency of various endogenous RSNOs in the presence ofmore » physiologically relevant concentrations of albumin and LMM-SH. Our results show that the sulfhydryl group of the cysteine moiety of albumin and LMM-SH has a dramatic effect on the vasodilatory potency of RSNO. Considering the equilibrium constants for S-transnitrosation reactions and the concentration of P-SH and LMM-SH we measured in healthy humans (aged 18-85 years), we infer that the age-dependency of hematic levels of LMM-SH may have a considerable impact in RSNO-mediated vasodilation. S-Nitrosoproteins such as S-nitrosoalbumin may constitute a relatively silent and constant amount of circulating RSNO. On the other hand, LMM-SH may mediate and control the biological actions of S-nitrosoproteins via S-transnitrosation reactions, by forming more potent nitric oxide-releasing LMM-S-nitrosothiols. Lifestyle habits, status of health and individual age are proven factors that, in turn, may influence the concentration of these compounds. These aspects should be taken into consideration when testing the vasodilatory effects of RSNO in pre-clinical studies. - Highlights: > A modification of the organ chamber apparatus for aortic ring bioassays is proposed. > The new apparatus can work in the presence of albumin at physiological concentrations. > Potency of RSNOs was studied in the presence of albumin and low molecular mass -SH. > Plasma thiol levels decrease with age. > Potency of RSNOs varies in dependence of age and more in general of plasma thiol status.« less

Herbal Medicine for Oligomenorrhea and Amenorrhea: A Systematic Review of Ancient and Conventional Medicine

PubMed Central

Tansaz, Mojgan; Nazemiyeh, Hossein; Fazljou, Seyed Mohammad Bagher

2018-01-01

Introduction Menstrual bleeding cessation is one of the most frequent gynecologic disorders among women in reproductive age. The treatment is based on hormone therapy. Due to the increasing request for alternative medicine remedies in the field of women's diseases, in present study, it was tried to overview medicinal plants used to treat oligomenorrhea and amenorrhea according to the pharmaceutical textbooks of traditional Persian medicine (TPM) and review the evidence in the conventional medicine. Methods This systematic review was designed and performed in 2017 in order to gather information regarding herbal medications of oligomenorrhea and amenorrhea in TPM and conventional medicine. This study had several steps as searching Iranian traditional medicine literature and extracting the emmenagogue plants, classifying the plants, searching the electronic databases, and finding evidences. To search traditional Persian medicine references, Noor digital library was used, which includes several ancient traditional medical references. The classification of plants was done based on the repetition and potency of the plants in the ancient literatures. The required data was gathered using databases such as PubMed, Scopus, Google Scholar, Cochrane Library, Science Direct, and web of knowledge. Results In present study of all 198 emmenagogue medicinal plants found in TPM, 87 cases were specified to be more effective in treating oligomenorrhea and amenorrhea. In second part of present study, where a search of conventional medicine was performed, 12 studies were found, which had 8 plants investigated: Vitex agnus-castus, Trigonella foenum-graecum, Foeniculum vulgare, Cinnamomum verum, Paeonia lactiflora, Sesamum indicum, Mentha longifolia, and Urtica dioica. Conclusion. Traditional Persian medicine has proposed many different medicinal plants for treatment of oligomenorrhea and amenorrhea. Although just few plants have been proven to be effective for treatment of menstrual irregularities, the results and the classification in present study can be used as an outline for future studies and treatment. PMID:29744355

Degradative enzymes modulate airway responses to intravenous neurokinins A and B.

PubMed

Shore, S A; Drazen, J M

1989-12-01

We studied the effects of the neutral endopeptidase (NEP) inhibitor thiorphan (1.7 mg/kg iv) and the angiotensin-converting enzyme (ACE) inhibitor captopril (5.7 mg/kg iv) on airway responses to rapid intravenous infusions of neurokinin A (NKA) and neurokinin B (NKB) in anesthetized, mechanically ventilated guinea pigs. The dose of NKA required to decrease pulmonary conductance to 50% of its base-line value (ED50GL) was fivefold less (P less than 0.0001) in animals treated with thiorphan compared with controls. NKA1-8, a product resulting from cleavage of NKA by NEP, had no bronchoconstrictor activity. Similar results were obtained by using NKB as the bronchoconstricting agent. Captopril had no significant effect on airway responses to NKA or NKB. In contrast, both thiorphan and captopril decrease the ED50GL for substance P (SP). We also compared the relative bronchoconstrictor potency of NKA, NKB, and SP. In control animals, the rank order of ED50GL values was NKA much less than NKB = SP. NKA also caused a more prolonged bronchoconstriction than SP or NKB. Thiorphan had no effect on the rank order of bronchoconstrictor potency, but in animals treated with captopril, the rank order of ED50GL values was altered to NKA less than SP less than NKB. These results suggest that degradation of NKA and NKB by NEP but not by ACE is an important determinant of the bronchoconstriction induced by these peptides. The degradation by ACE of SP but not NKA or NKB influences the observed relative potency of the three tachykinins as bronchoactive agents.

Heterodimerization of mu and delta opioid receptors: A role in opiate synergy.

PubMed

Gomes, I; Jordan, B A; Gupta, A; Trapaidze, N; Nagy, V; Devi, L A

2000-11-15

Opiate analgesics are widely used in the treatment of severe pain. Because of their importance in therapy, different strategies have been considered for making opiates more effective while curbing their liability to be abused. Although most opiates exert their analgesic effects primarily via mu opioid receptors, a number of studies have shown that delta receptor-selective drugs can enhance their potency. The molecular basis for these findings has not been elucidated previously. In the present study, we examined whether heterodimerization of mu and delta receptors could account for the cross-modulation previously observed between these two receptors. We find that co-expression of mu and delta receptors in heterologous cells followed by selective immunoprecipitation results in the isolation of mu-delta heterodimers. Treatment of these cells with extremely low doses of certain delta-selective ligands results in a significant increase in the binding of a mu receptor agonist. Similarly, treatment with mu-selective ligands results in a significant increase in the binding of a delta receptor agonist. This robust increase is also seen in SKNSH cells that endogenously express both mu and delta receptors. Furthermore, we find that a delta receptor antagonist enhances both the potency and efficacy of the mu receptor signaling; likewise a mu antagonist enhances the potency and efficacy of the delta receptor signaling. A combination of agonists (mu and delta receptor selective) also synergistically binds and potentiates signaling by activating the mu-delta heterodimer. Taken together, these studies show that heterodimers exhibit distinct ligand binding and signaling characteristics. These findings have important clinical ramifications and may provide new foundations for more effective therapies.

An Integrated View of Air Mutagenicity

EPA Science Inventory

The mutagenic potency of ambient air particulate material (PM) in the Salmonella mutagenicity assay (revertants/mg PM) varies only ~1 order of magnitude worldwide; however, the mutagenic potency of the air itself (revertants/m3 of air) varies ~5 orders of magnitude (IARC Monograp...

21 CFR 660.25 - Potency tests without reference preparations.

Code of Federal Regulations, 2012 CFR

2012-04-01

... manufacturer's package insert using red blood cells showing heterozygous or diminished expression of the... SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Blood Grouping Reagent § 660.25 Potency tests without reference preparations. Products for which Reference Blood...

21 CFR 660.25 - Potency tests without reference preparations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... manufacturer's package insert using red blood cells showing heterozygous or diminished expression of the... SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Blood Grouping Reagent § 660.25 Potency tests without reference preparations. Products for which Reference Blood...

21 CFR 660.25 - Potency tests without reference preparations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... manufacturer's package insert using red blood cells showing heterozygous or diminished expression of the... SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Blood Grouping Reagent § 660.25 Potency tests without reference preparations. Products for which Reference Blood...

21 CFR 660.25 - Potency tests without reference preparations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... manufacturer's package insert using red blood cells showing heterozygous or diminished expression of the... SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Blood Grouping Reagent § 660.25 Potency tests without reference preparations. Products for which Reference Blood...

21 CFR 660.25 - Potency tests without reference preparations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... manufacturer's package insert using red blood cells showing heterozygous or diminished expression of the... SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Blood Grouping Reagent § 660.25 Potency tests without reference preparations. Products for which Reference Blood...

Assays of homeopathic remedies in rodent behavioural and psychopathological models.

PubMed

Bellavite, Paolo; Magnani, Paolo; Marzotto, Marta; Conforti, Anita

2009-10-01

The first part of this paper reviews the effects of homeopathic remedies on several models of anxiety-like behaviours developed and described in rodents. The existing literature in this field comprises some fifteen exploratory studies, often published in non-indexed and non-peer-reviewed journals. Only a few results have been confirmed by multiple laboratories, and concern Ignatia, Gelsemium, Chamomilla (in homeopathic dilutions/potencies). Nevertheless, there are some interesting results pointing to the possible efficacy of other remedies, and confirming a statistically significant effect of high dilutions of neurotrophic molecules and antibodies. In the second part of this paper we report some recent results obtained in our laboratory, testing Aconitum, Nux vomica, Belladonna, Argentum nitricum, Tabacum (all 5CH potency) and Gelsemium (5, 7, 9 and 30CH potencies) on mice using ethological models of behaviour. The test was performed using coded drugs and controls in double blind (operations and calculations). After an initial screening that showed all the tested remedies (except for Belladonna) to have some effects on the behavioural parameters (light-dark test and open-field test), but with high experimental variability, we focused our study on Gelsemium, and carried out two complete series of experiments. The results showed that Gelsemium had several effects on the exploratory behaviour of mice, which in some models were highly statistically significant (p < 0.001), in all the dilutions/dynamizations used, but with complex differences according to the experimental conditions and test performed. Finally, some methodological issues of animal research in this field of homeopathy are discussed. The "Gelsemium model" - encompassing experimental studies in vitro and in vivo from different laboratories and with different methods, including significant effects of its major active principle gelsemine - may play a pivotal rule for investigations on other homeopathic remedies.

Rationale for a 'Male Lumpectomy,' a Prostate Cancer Targeted Approach Using Cryoablation: Results in 21 Patients with at Least 2 Years of Follow-Up

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

Onik, Gary

2008-01-15

Background. Prostate cancer in men raises many of the same issues that breast cancer does in women. Complications of prostate cancer treatment, including impotence and incontinence, affect the self-image and psyche of a man no less than does the loss of a breast in a woman. We present a pilot study in which 21 patients were treated with a focal cryoablation procedure. Methods. Focal cryoablation was performed using biplane transrectal ultrasound if the tumor was confined to only one prostate lobe. Preoperative PSA values were recorded. Cryoablation was planned to encompass the area of known tumor. PSA values were obtainedmore » every 3 months for 2 years and every 6 months thereafter. Potency and continence status was obtained at the same intervals. Routine biopsy was obtained at 1 year. Results. Twenty-one patients had focal cryoablation. Follow-up ranged from 24 to 105 months with a mean of 50 months. Twenty of 21 (95%) patients have stable PSA values with no evidence for cancer, despite 10 patients being at medium to high risk for recurrence. All patients biopsied (n = 19) were negative for tumor. Potency was maintained in 17 of 21 patients (80%). No other complications, including incontinence or fistula formation, were noted. Conclusion. These preliminary results indicate a 'male lumpectomy,' in which the prostate tumor region itself is destroyed, appears to preserve potency in a majority of patients and limits other complications, without compromising cancer control. If these results are confirmed by further studies and long-term follow-up, this treatment approach could have a profound effect on prostate cancer management.« less

A novel approach for preparation of the antisera reagent for potency determination of inactivated H7N9 influenza vaccines.

PubMed

Schmeisser, Falko; Jing, Xianghong; Joshi, Manju; Vasudevan, Anupama; Soto, Jackeline; Li, Xing; Choudhary, Anil; Baichoo, Noel; Resnick, Josephine; Ye, Zhiping; McCormick, William; Weir, Jerry P

2016-03-01

The potency of inactivated influenza vaccines is determined using a single-radial immunodiffusion (SRID) assay and requires standardized reagents consisting of a Reference Antigen and an influenza strain-specific antiserum. Timely availability of reagents is a critical step in influenza vaccine production, and the need for backup approaches for reagent preparation is an important component of pandemic preparedness. When novel H7N9 viruses emerged in China in 2013, candidate inactivated H7N9 influenza vaccines were developed for evaluation in clinical trials, and reagents were needed to measure vaccine potency. We previously described an alternative approach for generating strain-specific potency antisera, utilizing modified vaccinia virus Ankara vectors to produce influenza hemagglutinin (HA)-containing virus-like particles (VLPs) for immunization. Vector-produced HA antigen is not dependent upon the success of the traditional bromelain-digestion and HA purification. Antiserum for H7N9 vaccines, produced after immunization of sheep with preparations of bromelain-HA (br-HA), was not optimal for the SRID assay, and the supply of antiserum was limited. However, antiserum obtained from sheep boosted with VLPs containing H7 HA greatly improved the ring quality in the SRID assay. Importantly, this antiserum worked well with both egg- and cell-derived antigen and was distributed to vaccine manufacturers. Utilizing a previously developed approach for preparing vaccine potency antiserum, we have addressed a major bottleneck encountered in preparation of H7N9 vaccine reagents. The combination of br-HA and mammalian VLPs for sequential immunization represents the first use of an alternative approach for producing an influenza vaccine potency antiserum. © 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Statistical analysis of radioimmunoassay. In comparison with bioassay (in Japanese)

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

Nakano, R.

1973-01-01

Using the data of RIA (radioimmunoassay), statistical procedures for dealing with two problems of the linearization of dose response curve and calculation of relative potency were described. There were three methods for linearization of dose response curve of RIA. In each method, the following parameters were shown on the horizontal and vertical axis: dose x, (B/T)/sup -1/; c/x + c, B/T (C: dose which makes B/T 50%); log x, logit B/T. Among them, the last method seems to be most practical. The statistical procedures for bioassay were employed for calculating the relative potency of unknown samples compared to the standardmore » samples from dose response curves of standand and unknown samples using regression coefficient. It is desirable that relative potency is calculated by plotting more than 5 points in the standard curve and plotting more than 2 points in unknow samples. For examining the statistical limit of precision of measuremert, LH activity of gonadotropin in urine was measured and relative potency, precision coefficient and the upper and lower limits of relative potency at 95% confidence limit were calculated. On the other hand, bioassay (by the ovarian ascorbic acid reduction method and anteriol lobe of prostate weighing method) was done in the same samples, and the precision was compared with that of RIA. In these examinations, the upper and lower limits of the relative potency at 95% confidence limit were near each other, while in bioassay, a considerable difference was observed between the upper and lower limits. The necessity of standardization and systematization of the statistical procedures for increasing the precision of RIA was pointed out. (JA)« less

Long-term effect of statins on the risk of new-onset osteoporosis: A nationwide population-based cohort study.

PubMed

Lin, Tsung-Kun; Chou, Pesus; Lin, Ching-Heng; Hung, Yi-Jen; Jong, Gwo-Ping

2018-01-01

Several observational cohort and meta-analytical studies in humans have shown that statin users have a lower risk of fractures or greater bone mineral densities (BMD) than nonusers. However, some studies including randomized clinical trials have the opposite results, particularly in Asian populations. This study investigates the impacts of statins on new-onset osteoporosis in Taiwan. In a nationwide retrospective population-based cohort study, 45,342 subjects aged between 50-90 years having received statin therapy (statin-users) since January 1 2001, and observed through December 31 2013 were selected from the National Health Insurance Research Database of Taiwan. Likewise, 115,594 patients had no statin therapy (statin-non-users) were included as controls in this study. Multivariable Cox proportional hazards analysis for drug exposures was employed to evaluate the association between statin treatment and new-onset of osteoporosis risk. We also used the long-rank test to evaluate the difference of probability of osteoporosis-free survival. During the 13-year follow-up period, 16,146 of all enrolled subjects (10.03%) developed osteoporosis, including 3097 statin-users (6.83%) and 13,049 statin-non-users (11.29%). Overall, statin therapy reduced the risk of new-onset osteoporosis by 48% (adjusted hazard ratio [HR] 0.52; 95% CI 0.50 to 0.54). A dose-response relationship between statin treatment and the risk of new-onset osteoporosis was observed. The adjusted hazard ratios for new-onset osteoporosis were 0.84 (95% CI, 0.78 to 0.90), 0.56 (95% CI, 0.52 to 0.60) and 0.23 (95% CI, 0.21 to 0.25) when cumulative defined daily doses (cDDDs) ranged from 28 to 90, 91 to 365, and more than 365, respectively, relative to nonusers. Otherwise, high-potency statins (rosuvastatin and atorvastatin) and moderate-potency statin (simvastatin) seemed to have a potential protective effect for osteoporosis. In this population-based cohort study, we found that statin use is associated with a decreased risk of osteoporosis in both genders. The osteoprotective effect of statins seemed to be more prominent with a dependency on the cumulative dosage and statin intensity.

The Risk of Opioid Intoxications or Related Events and the Effect of Alcohol-Related Disorders: A Retrospective Cohort Study in German Patients Treated with High-Potency Opioid Analgesics.

PubMed

Jobski, K; Kollhorst, B; Schink, T; Garbe, Edeltraut

2015-09-01

Intoxications involving prescription opioids are a major public health problem in many countries. When taken with opioids, alcohol can enhance the effects of opioids, particularly in the central nervous system. However, data quantifying the impact of alcohol involvement in opioid-related intoxications are limited. Using claims data from the German Pharmacoepidemiological Research Database (GePaRD), we conducted a retrospective cohort study based on users of high-potency opioid (HPO) analgesics during the years 2005-2009. HPO use was classified as extended-release, immediate-release or both. We calculated incidence rates (IRs) for opioid intoxications or related events as well as adjusted IR ratios (aIRR) comparing HPO-treated patients with alcohol-related disorders (ARDs) to those without ARDs overall and within each HPO category. During the study period, 308,268 HPO users were identified with an overall IR of 340.4 per 100,000 person-years [95 % confidence interval (CI) 325.5-355.7]. The risk was highest when patients received concomitant treatment with extended- and immediate-release HPOs (IR 1093.8; 95 % CI 904.6-1310.9). ARDs increased the risk during HPO use by a factor of 1.7 and the highest aIRR was seen when comparing patients simultaneously exposed to extended- and immediate-release HPOs with ARDs to those without ARD also after excluding patients with potential improper/non-medical HPO use. Physicians should be aware of these elevated risks in HPO patients with ARDs. Active patient education by healthcare providers regarding the risk of opioid intoxications or related events due to alcohol in conjunction with HPOs is warranted.

Natural products used as a chemical library for protein-protein interaction targeted drug discovery.

PubMed

Jin, Xuemei; Lee, Kyungro; Kim, Nam Hee; Kim, Hyun Sil; Yook, Jong In; Choi, Jiwon; No, Kyoung Tai

2018-01-01

Protein-protein interactions (PPIs), which are essential for cellular processes, have been recognized as attractive therapeutic targets. Therefore, the construction of a PPI-focused chemical library is an inevitable necessity for future drug discovery. Natural products have been used as traditional medicines to treat human diseases for millennia; in addition, their molecular scaffolds have been used in diverse approved drugs and drug candidates. The recent discovery of the ability of natural products to inhibit PPIs led us to use natural products as a chemical library for PPI-targeted drug discovery. In this study, we collected natural products (NPDB) from non-commercial and in-house databases to analyze their similarities to small-molecule PPI inhibitors (iPPIs) and FDA-approved drugs by using eight molecular descriptors. Then, we evaluated the distribution of NPDB and iPPIs in the chemical space, represented by the molecular fingerprint and molecular scaffolds, to identify the promising scaffolds, which could interfere with PPIs. To investigate the ability of natural products to inhibit PPI targets, molecular docking was used. Then, we predicted a set of high-potency natural products by using the iPPI-likeness score based on a docking score-weighted model. These selected natural products showed high binding affinities to the PPI target, namely XIAP, which were validated in an in vitro experiment. In addition, the natural products with novel scaffolds might provide a promising starting point for further medicinal chemistry developments. Overall, our study shows the potency of natural products in targeting PPIs, which might help in the design of a PPI-focused chemical library for future drug discovery. Copyright © 2017 Elsevier Inc. All rights reserved.

Cocaine-like discriminative stimulus effects of "norepinephrine-preferring" monoamine releasers: time course and interaction studies in rhesus monkeys.

PubMed

Kohut, Stephen J; Jacobs, David S; Rothman, Richard B; Partilla, John S; Bergman, Jack; Blough, Bruce E

2017-12-01

The therapeutic potential of monoamine releasers with prominent dopaminergic effects is hindered by their high abuse liability. The present study examined the effects of several novel "norepinephrine (NE)-preferring" monoamine releasers relative to non-selective monoamine releasers, d-amphetamine and d-methamphetamine, in rhesus monkeys trained to discriminate cocaine. NE-preferring releasers were approximately 13-fold more potent for NE compared to dopamine release and ranged in potency for serotonin release (PAL-329 < l-methamphetamine < PAL-169). Adult rhesus macaques were trained to discriminate 0.4 mg/kg, IM cocaine on a 30-response fixed ratio schedule of food reinforcement. Substitution studies determined the extent to which test drugs produced cocaine-like discriminative stimulus effects and their time course. Drug interaction studies determined whether pretreatment with test drugs altered the discriminable effects of cocaine. Results show that cocaine, d-amphetamine, and d-methamphetamine dose-dependently substituted for cocaine with similar potencies. Among the "NE-preferring" releasers, PAL-329 and l-methamphetamine also dose-dependently substituted for cocaine but differed in potency. PAL-169 failed to substitute for cocaine up to a dose that disrupted responding. When administered prior to cocaine, only d-amphetamine and PAL-329 significantly shifted the cocaine dose-effect function leftward indicating enhancement of cocaine's discriminative stimulus effects. These data suggest that greater potency for NE relative to dopamine release (up to 13-fold) does not interfere with the ability of a monoamine releaser to produce cocaine-like discriminative effects but that increased serotonin release may have an inhibitory effect. Further characterization of these and other "NE-preferring" monoamine releasers should provide insight into their potential for the management of cocaine addiction.

Rabies deaths in Pakistan: results of ineffective post-exposure treatment.

PubMed

Parviz, Shehzad; Chotani, Rashid; McCormick, Joseph; Fisher-Hoch, Sue; Luby, Stephen

2004-11-01

To estimate the incidence of rabies and the effectiveness of post-exposure treatment (PET) in Pakistan. Rabies cases admitted from July 1993 to December 1994 to a public rabies isolation hospital were analyzed. Two samples (one sample each from a separate peripheral site) of a single batch of sheep brain vaccine (SBV) were also tested for potency by the National Institute of Health (NIH) test in May 1997. Forty patients were admitted with a history of clinical rabies. The median age was 22 years and 55% were under 15. Thirteen (23%) victims did not receive any vaccine; the remaining 27 (67%) received SBV only, and of these, 16 (40%) received a full course of SBV. No rabies immunoglobulins (RIG) or cell culture vaccines were administered. There were frequent power blackouts and no back-up supply at the public hospital. In-house potency testing of the vaccine batch by the manufacturer was adequate, although it was not tested by the World Health Organization (WHO) recommended NIH test. Samples of SBV of the same batch collected at the peripheral sites showed no potency. Rabies incidence was estimated to range between 7.0 to 9.8 cases per million annually. A multi-sectorial approach is needed to decrease rabies incidence in Pakistan. Public and healthcare practitioner education on prompt and appropriate PET, especially the use of cost-effective cell culture intradermal regimens, is needed urgently. The NIH test should be employed for vaccine potency testing. An independent agency is needed for monitoring vaccine quality and strategies are needed for maintaining cold chain. SBV should be replaced by locally manufactured second-generation cell culture rabies vaccine. Purified equine rabies immunoglobulin (ERIG) should be manufactured locally to meet national needs. Furthermore, effective dog control strategies should be implemented to decrease the rabies reservoir.

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

Tsukamoto, Ikuko, E-mail: tukamoto@med.kagawa-u.ac.jp; Sakakibara, Norikazu; Maruyama, Tokumi

Research highlights: {yields} A novel nucleic acid analogue (2Cl-C.OXT-A, m.w. 284) showed angiogenic potency. {yields} It stimulated the tube formation, proliferation and migration of HUVEC in vitro. {yields} 2Cl-C.OXT-A induced the activation of ERK1/2 and MEK in HUVEC. {yields} Angiogenic potency in vivo was confirmed in CAM assay and rabbit cornea assay. {yields} A synthesized small angiogenic agent would have great clinical therapeutic value. -- Abstract: A novel nucleic acid analogue (2Cl-C.OXT-A) significantly stimulated tube formation of human umbilical endothelial cells (HUVEC). Its maximum potency at 100 {mu}M was stronger than that of vascular endothelial growth factor (VEGF), a positivemore » control. At this concentration, 2Cl-C.OXT-A moderately stimulated proliferation as well as migration of HUVEC. To gain mechanistic insights how 2Cl-C.OXT-A promotes angiogenic responses in HUVEC, we performed immunoblot analyses using phospho-specific antibodies as probes. 2Cl-C.OXT-A induced robust phosphorylation/activation of MAP kinase ERK1/2 and an upstream MAP kinase kinase MEK. Conversely, a MEK inhibitor PD98059 abolished ERK1/2 activation and tube formation both enhanced by 2Cl-C.OXT-A. In contrast, MAP kinase responses elicited by 2Cl-C.OXT-A were not inhibited by SU5416, a specific inhibitor of VEGF receptor tyrosine kinase. Collectively these results suggest that 2Cl-C.OXT-A-induces angiogenic responses in HUVEC mediated by a MAP kinase cascade comprising MEK and ERK1/2, but independently of VEGF receptor tyrosine kinase. In vivo assay using chicken chorioallantoic membrane (CAM) and rabbit cornea also suggested the angiogenic potency of 2Cl-C.OXT-A.« less

Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

PubMed Central

Di Forti, Marta; Sallis, Hannah; Allegri, Fabio; Trotta, Antonella; Ferraro, Laura; Stilo, Simona A.; Marconi, Arianna; La Cascia, Caterina; Reis Marques, Tiago; Pariante, Carmine; Dazzan, Paola; Mondelli, Valeria; Paparelli, Alessandra; Kolliakou, Anna; Prata, Diana; Gaughran, Fiona; David, Anthony S.; Morgan, Craig; Stahl, Daniel; Khondoker, Mizanur; MacCabe, James H.; Murray, Robin M.

2014-01-01

Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users. PMID:24345517

Reconnaissance of dioxin-like and estrogen-like toxicities in sediments of Taean, Korea-seven years after the Hebei Spirit oil spill.

PubMed

Kim, Cheolmin; Lee, Inae; Jung, Dawoon; Hong, Seongjin; Khim, Jong Seong; Giesy, John P; Yim, Un Hyuk; Shim, Won Joon; Choi, Kyungho

2017-02-01

Oil spills near the coastlines may damage marine and intertidal ecosystem. Constituents of the oil have been reported to cause toxic consequences mediated by aryl hydrocarbon receptor (AhR), and estrogen receptor (ER). In the present study, AhR- and ER-mediated toxicities of coastal sediments of Taean were investigated seven years after Hebei Spirit oil spill (HSOS). Sediment samples were collected on June and October 2014 from seven locations along the Taean coastline, where signs of oil spill were detected. Sediment samples were extracted in Soxhlet extractors and further processed through activated silica gels to separate into four fractions; F1 (saturate hydrocarbons), F2 (aromatic hydrocarbons), F3 (resins and polar compounds), and F4 (residues). ER-mediated and AhR-mediated potencies (% E2 max and % TCDD max ) of each fraction were determined using MVLN cells and H4IIE-luc cells, respectively. F2 and F3 fractions of Sinduri 1, Sinduri 2, and Sogeunri 1 samples showed greater AhR-mediated potencies (up to 107% TCDD max ). Chemical analysis revealed that PAH components are correlated with AhR-binding activities. The % E2 max results varied by sample: While there was no noticeable induction of ER-dependent responses (<45%), some aromatics fractions (F2) exhibited the highest ER-mediated responses. Compared with previous reports from the same sites, both AhR-mediated and ER-mediated potencies have decreased over time. Nevertheless, AhR-mediated potencies could be identified in the environmental samples even after 7 years of the incident. Therefore, possible ecosystem implications of these findings should be further investigated. Copyright © 2016 Elsevier Ltd. All rights reserved.

Source contributions to total concentrations and carcinogenic potencies of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air: a case study in Suzhou City, China.

PubMed

Xuan, Zhiqiang; Bi, Chenglu; Li, Jiafu; Nie, Jihua; Chen, Zhihai

2017-10-01

The potential source categories and source contributions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air from Suzhou City, China, were performed by principal component analysis-multiple linear regression (PCA-MLR) and positive matrix factorization (PMF). The carcinogenic potencies of PCDD/Fs were quantitatively apportioned based on the positive matrix factorization-toxic equivalent concentration (PMF-TEQ) method. The results of the present study were summarized as follows. (1) The total concentrations and toxic equivalent concentrations of PCDD/Fs (∑PCDD/Fs and TEQ) in ambient air from Suzhou City were 1.34-42.80 pg N m -3 and 0.081-1.22 pg I-TEQ N m -3 , respectively. (2) PCA-MLR suggested that industrial combustion (IC), electric arc furnaces (EAFs) and secondary aluminum smelters (ALSs), unleaded gas-fueled vehicle sources (UGFVs), ALSs, and hazardous solid waste incinerators (HSWIs) could be the primary PCDD/F contributors, accounting for 13.2, 16.7, 35.5, 19.4, and 15.2% of ∑PCDD/Fs, respectively. (3) PMF and PMF-TEQ indicated that EAFs (carbon steel), UGFVs, IC, ALSs, municipal solid waste incinerators (MSWIs) and hospital waste incinerators (HWIs), and HSWIs contributed 10.9, 10.9, 42.8, 11.3, 10.7, and 13.4% to ∑PCDD/Fs, but contributed 8.3, 12.3, 50.3, 12.7, 6.0, and 10.4% to carcinogenic potencies of PCDD/Fs. This study was the first attempt to quantitatively apportion the source-specific carcinogenic potencies of PCDD/Fs in ambient air.

Advances in neglected tropical disease vaccines: Developing relative potency and functional assays for the Na-GST-1/Alhydrogel hookworm vaccine

PubMed Central

Brelsford, Jill B.; Plieskatt, Jordan L.; Yakovleva, Anna; Jariwala, Amar; Keegan, Brian P.; Peng, Jin; Xia, Pengjun; Li, Guangzhao; Campbell, Doreen; Periago, Maria Victoria; Correa-Oliveira, Rodrigo; Bottazzi, Maria Elena; Hotez, Peter J.

2017-01-01

A new generation of vaccines for the neglected tropical diseases (NTDs) have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, vaccine stability testing programs. A key measure of vaccine stability testing is "relative potency" or the immunogenicity of the vaccine during storage. As with most NTD vaccines, the Na-GST-1/Alhydrogel Hookworm Vaccine was not developed by attenuation or inactivation of the pathogen (Necator americanus), so conventional methods for measuring relative potency are not relevant for this investigational product. Herein, we describe a novel relative potency testing program and report for the first time on the clinical lot of this NTD vaccine during its first 60 months of storage at 2–8°C. We also describe the development of a complementary functional assay that measures the ability of IgG from animals or humans immunized with Na-GST-1/Alhydrogel to neutralize this important hookworm enzyme. While 90% inhibition of the catalytic activity of Na-GST-1 was achieved in animals immunized with Na-GST-1/Alhydrogel, lower levels of inhibition were observed in immunized humans. Moreover, anti-Na-GST-1 antibodies from volunteers in non-hookworm endemic areas were better able to inhibit catalytic activity than anti-Na-GST-1 antibodies from volunteers resident in hookworm endemic areas. The results described herein provide the critical tools for the product development of NTD vaccines. PMID:28192438

An Extended Structure–Activity Relationship of Nondioxin-Like PCBs Evaluates and Supports Modeling Predictions and Identifies Picomolar Potency of PCB 202 Towards Ryanodine Receptors

PubMed Central

Feng, Wei; Zheng, Jing; Dong, Yao; Li, Xueshu; Lehmler, Hans-Joachim; Pessah, Isaac N.

2017-01-01

Nondioxin-like polychlorinated biphenyls (NDL PCBs) activate ryanodine-sensitive Ca2+ channels (RyRs) and this activation has been associated with neurotoxicity in exposed animals. RyR-active congeners follow a distinct structure–activity relationship and a quantitative structure–activity relationship (QSAR) predicts that a large number of PCBs likely activate the receptor, which requires validation. Additionally, previous structural based conclusions have been established using receptor ligand binding assays but the impact of varying PCB structures on ion channel gating behavior is not understood. We used [3H]Ryanodine ([3H]Ry) binding to assess the RyR-activity of 14 previously untested PCB congeners evaluating the predictability of the QSAR. Congeners determined to display widely varying potency were then assayed with single channel voltage clamp analysis to assess direct influences on channel gating kinetics. The RyR-activity of individual PCBs assessed in in vitro assays followed the general pattern predicted by the QSAR but binding and lipid bilayer experiments demonstrated higher potency than predicted. Of the 49 congeners tested to date, tetra-ortho PCB 202 was found to be the most potent RyR-active congener increasing channel open probability at 200 pM. Shifting meta-substitutions to the para-position resulted in a > 100-fold reduction in potency as seen with PCB 197. Non-ortho PCB 11 was found to lack activity at the receptor supporting a minimum mono-ortho substitution for PCB RyR activity. These findings expand and support previous SAR assessments; where out of the 49 congeners tested to date 42 activate the receptor demonstrating that the RyR is a sensitive and common target of PCBs. PMID:27655348

Mechanism of action of a nanomolar potent, allosteric antagonist of the thyroid-stimulating hormone receptor

PubMed Central

van Koppen, Chris J; de Gooyer, Marcel E; Karstens, Willem-Jan; Plate, Ralf; Conti, Paolo GM; van Achterberg, Tanja AE; van Amstel, Monique GA; Brands, Jolanda HGM; Wat, Jesse; Berg, Rob JW; Lane, J Robert D; Miltenburg, Andre MM; Timmers, C Marco

2012-01-01

BACKGROUND AND PURPOSE Graves' disease (GD) is an autoimmune disease in which the thyroid is overactive, producing excessive amounts of thyroid hormones, caused by thyroid-stimulating hormone (TSH) receptor-stimulating immunoglobulins (TSIs). Many GD patients also suffer from thyroid eye disease (Graves' ophthalmopathy or GO), as TSIs also activate TSH receptors in orbital tissue. We recently developed low molecular weight (LMW) TSH receptor antagonists as a novel therapeutic strategy for the treatment of GD and GO. Here, we determined the molecular pharmacology of a prototypic, nanomolar potent LMW TSH receptor antagonist, Org 274179-0. EXPERIMENTAL APPROACH Using CHO cells heterogeneously expressing human TSH receptors and rat FRTL-5 cells endogenously expressing rat TSH receptors, we determined the potency and efficacy of Org 274179-0 at antagonizing TSH- and TSI-induced TSH receptor signalling and its cross-reactivity at related follicle-stimulating hormone and luteinizing hormone receptors. We analysed the allosteric mode of interaction of Org 274179-0 and determined whether it is an inverse agonist at five naturally occurring, constitutively active TSH receptor mutants. KEY RESULTS Nanomolar concentrations of Org 274179-0 completely inhibited TSH (and TSI)-mediated TSH receptor activation with little effect on the potency of TSH, in accordance with an allosteric mechanism of action. Conversely, increasing levels of TSH receptor stimulation only marginally reduced the antagonist potency of Org 274179-0. Org 274179-0 fully blocked the increased basal activity of all the constitutively active TSH receptor mutants tested with nanomolar potencies. CONCLUSIONS AND IMPLICATIONS Nanomolar potent TSH receptor antagonists like Org 274179-0 have therapeutic potential for the treatment of GD and GO. PMID:22014107

Enhanced potency of a fucose-free monoclonal antibody being developed as an Ebola virus immunoprotectant.

PubMed

Zeitlin, Larry; Pettitt, James; Scully, Corinne; Bohorova, Natasha; Kim, Do; Pauly, Michael; Hiatt, Andrew; Ngo, Long; Steinkellner, Herta; Whaley, Kevin J; Olinger, Gene G

2011-12-20

No countermeasures currently exist for the prevention or treatment of the severe sequelae of Filovirus (such as Ebola virus; EBOV) infection. To overcome this limitation in our biodefense preparedness, we have designed monoclonal antibodies (mAbs) which could be used in humans as immunoprotectants for EBOV, starting with a murine mAb (13F6) that recognizes the heavily glycosylated mucin-like domain of the virion-attached glycoprotein (GP). Point mutations were introduced into the variable region of the murine mAb to remove predicted human T-cell epitopes, and the variable regions joined to human constant regions to generate a mAb (h-13F6) appropriate for development for human use. We have evaluated the efficacy of three variants of h-13F6 carrying different glycosylation patterns in a lethal mouse EBOV challenge model. The pattern of glycosylation of the various mAbs was found to correlate to level of protection, with aglycosylated h-13F6 providing the least potent efficacy (ED(50) = 33 μg). A version with typical heterogenous mammalian glycoforms (ED(50) = 11 μg) had similar potency to the original murine mAb. However, h-13F6 carrying complex N-glycosylation lacking core fucose exhibited superior potency (ED(50) = 3 μg). Binding studies using Fcγ receptors revealed enhanced binding of nonfucosylated h-13F6 to mouse and human FcγRIII. Together the results indicate the presence of Fc N-glycans enhances the protective efficacy of h-13F6, and that mAbs manufactured with uniform glycosylation and a higher potency glycoform offer promise as biodefense therapeutics.

Neuromedin B receptor in esophagus: evidence for subtypes of bombesin receptors

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

Von Schrenck, T.; Heinz-Erian, P.; Moran, T.

1989-04-01

To identify receptors for bombesin-related peptides in the rat esophagus, we measured binding of 125I-Bolton-Hunter neuromedin B (125I-BH-neuromedin B) and 125I-(Tyr4)bombesin to tissue sections from the rat esophagus and compared the results with those for rat pancreas. Esophagus bound both tracers, whereas pancreas bound only 125I-(Tyr4)bombesin. In each tissue binding was saturable, dependent on pH, on time, and on temperature, reversible, and specific. Autoradiography demonstrated binding of both tracers only to the muscularis mucosae of the esophagus and binding of 125I-(Tyr4)bombesin diffusely over pancreatic acini. In the esophagus, the relative potencies for inhibition of binding of both tracers were asmore » follows: neuromedin B greater than bombesin greater than GRP = neuromedin C; similar relative potencies were found for causing contraction of muscle strips from whole esophagus and from the isolated muscularis mucosae. In pancreas tissue sections and dispersed acini, the relative potencies for inhibition of binding of 125I-(Tyr4)bombesin were as follows: bombesin greater than GRP = neuromedin C much greater than neuromedin B. Similar relative potencies were found for stimulation of enzyme secretion from dispersed pancreatic acini. Computer analysis in both tissues demonstrated only a single binding site. The present study demonstrates that rat esophagus muscle possesses specific receptors for bombesin-related peptides. Furthermore, this study shows that the esophageal bombesin receptors represent a previously unidentified class of bombesin receptors in that they have a higher affinity for neuromedin B than for bombesin. In contrast, the pancreatic bombesin receptors have, like all other bombesin receptors described to date, a high affinity for bombesin, but low affinity for neuromedin B.« less

Comparative reactivity of human IgE to cynomolgus monkey and human effector cells and effects on IgE effector cell potency

PubMed Central

Saul, Louise; Saul, Louise; Josephs, Debra H; Josephs, Debra H; Cutler, Keith; Cutler, Keith; Bradwell, Andrew; Bradwell, Andrew; Karagiannis, Panagiotis; Karagiannis, Panagiotis; Selkirk, Chris; Selkirk, Chris; Gould, Hannah J; Gould, Hannah J; Jones, Paul; Jones, Paul; Spicer, James F; Spicer, James F; Karagiannis, Sophia N; Karagiannis, Sophia N

2014-01-01

Background: Due to genetic similarities with humans, primates of the macaque genus such as the cynomolgus monkey are often chosen as models for toxicology studies of antibody therapies. IgE therapeutics in development depend upon engagement with the FcεRI and FcεRII receptors on immune effector cells for their function. Only limited knowledge of the primate IgE immune system is available to inform the choice of models for mechanistic and safety evaluations.   Methods: The recognition of human IgE by peripheral blood lymphocytes from cynomolgus monkey and man was compared. We used effector cells from each species in ex vivo affinity, dose-response, antibody-receptor dissociation and potency assays. Results: We report cross-reactivity of human IgE Fc with cynomolgus monkey cells, and comparable binding kinetics to peripheral blood lymphocytes from both species. In competition and dissociation assays, however, human IgE dissociated faster from cynomolgus monkey compared with human effector cells. Differences in association and dissociation kinetics were reflected in effector cell potency assays of IgE-mediated target cell killing, with higher concentrations of human IgE needed to elicit effector response in the cynomolgus monkey system. Additionally, human IgE binding on immune effector cells yielded significantly different cytokine release profiles in each species. Conclusion: These data suggest that human IgE binds with different characteristics to human and cynomolgus monkey IgE effector cells. This is likely to affect the potency of IgE effector functions in these two species, and so has relevance for the selection of biologically-relevant model systems when designing pre-clinical toxicology and functional studies. PMID:24492303

Analysis of the mechanisms that underlie absorption of botulinum toxin by the inhalation route.

PubMed

Al-Saleem, Fetweh H; Ancharski, Denise M; Joshi, Suresh G; Elias, M; Singh, Ajay; Nasser, Zidoon; Simpson, Lance L

2012-12-01

Botulinum toxin is a highly potent oral and inhalation poison, which means that the toxin must have an efficient mechanism for penetration of epithelial barriers. To date, three models for toxin passage across epithelial barriers have been proposed: (i) the toxin itself undergoes binding and transcytosis; (ii) an auxiliary protein, HA35, transports toxin from the apical to the basal side of epithelial cells; and (iii) an auxiliary protein, HA35, acts on the basal side of epithelial cells to disrupt tight junctions, and this permits paracellular flux of toxin. These models were evaluated by studying toxin absorption following inhalation exposure in mice. Three types of experiments were conducted. In the first, the potency of pure neurotoxin was compared with that of progenitor toxin complex, which contains HA35. The results showed that the rate and extent of toxin absorption, as well as the potency of absorbed toxin, did not depend upon, nor were they enhanced by, the presence of HA35. In the second type of experiment, the potencies of pure neurotoxin and progenitor toxin complex were compared in the absence or presence of antibodies on the apical side of epithelial cells. Antibodies directed against the neurotoxin protected against challenge, but antibodies against HA35 did not. In the final type of experiment, the potency of pure neurotoxin and toxin complex was compared in animals pretreated to deliver antibodies to the basal side of epithelial cells. Once again, antibodies directed against the neurotoxin provided resistance to challenge, but antibodies directed against HA35 did not. Taken collectively, the data indicate that the toxin by itself is capable of crossing epithelial barriers. The data do not support any hypothesis in which HA35 is essential for toxin penetration of epithelial barriers.

Hypoxic Stress Forces Irreversible Differentiation of a Majority of Mouse Trophoblast Stem Cells Despite FGF4.

PubMed

Yang, Yu; Arenas-Hernandez, Marcia; Gomez-Lopez, Nardhy; Dai, Jing; Parker, Graham C; Puscheck, Elizabeth E; Rappolee, Daniel A

2016-11-01

Hypoxic, hyperosmotic, and genotoxic stress slow mouse trophoblast stem cell (mTSC) proliferation, decrease potency/stemness, and increase differentiation. Previous reports suggest a period of reversibility in stress-induced mTSC differentiation. Here we show that hypoxic stress at 0.5% O 2 decreased potency factor protein by ∼60%-90% and reduced growth to nil. Hypoxia caused a 35-fold increase in apoptosis at Day 3 and a 2-fold increase at Day 6 above baseline. The baseline apoptosis rate was only 0.3%. Total protein was never less than baseline during hypoxic treatment, suggesting 0.5% O 2 is a robust, nonmorbid stressor. Hypoxic stress induced ∼50% of trophoblast giant cell (TGC) differentiation with a simultaneous 5- to 6-fold increase in the TGC product antiluteolytic prolactin family 3, subfamily d, member 1 (PRL3D1), despite the presence of fibroblast growth factor 4 (FGF4). Hypoxia-induced TGC differentiation was also supported by potency and differentiation mRNA marker analysis. FGF4 removal at 20% O 2 committed cell fate towards irreversible differentiation at 2 days, with similar TGC percentages after an additional 3 days of culture under potency conditions when FGF4 was readded or under differentiation conditions without FGF4. However, hypoxic stress required 4 days to irreversibly differentiate cells. Runted stem cell growth, forced differentiation of fewer cells, and irreversible differentiation limit total available stem cell population. Were mTSCs to respond to stress in a similar mode in vivo, miscarriage might occur as a result, which should be tested in the future. © 2016 by the Society for the Study of Reproduction, Inc.

Discovery of a Novel General Anesthetic Chemotype Using High-throughput Screening

PubMed Central

McKinstry-Wu, Andrew R.; Bu, Weiming; Rai, Ganesha; Lea, Wendy A.; Weiser, Brian P.; Liang, David F.; Simeonov, Anton; Jadhav, Ajit; Maloney, David J.; Eckenhoff, Roderic G.

2014-01-01

Background The development of novel anesthetics has historically been a process of combined serendipity and empiricism, with most recent new anesthetics developed via modification of existing anesthetic structures. Methods Using a novel high-throughput screen employing the fluorescent anesthetic 1-aminoanthracene (1-AMA) and apoferritin as a surrogate for on-pathway anesthetic protein target(s), we screened a 350,000 compound library for competition with 1-AMA-apoferritin binding. Hit compounds meeting structural criteria had their binding affinities for apoferritin quantified with isothermal titration calorimetry and were tested for γ-aminobutyric acid type A-receptor binding using a flunitrazepam binding assay. Chemotypes with a strong presence in the top 700 and exhibiting activity via isothermal titration calorimetry were selected for medicinal chemistry optimization including testing for anesthetic potency and toxicity in an in vivo Xenopus laevis tadpole assay. Compounds with low toxicity and high potency were tested for anesthetic potency in mice. Results From an initial chemical library of over 350,000 compounds, we identified 2,600 compounds that potently inhibited 1-AMA binding to apoferritin. A subset of compounds chosen by structural criteria (700) was successfully reconfirmed using the initial assay. Based upon a strong presence in both the initial and secondary screens the 6-phenylpyridazin-3(2H)-one chemotype was assessed for anesthetic activity in tadpoles. Medicinal chemistry efforts identified four compounds with high potency and low toxicity in tadpoles, two were found to be effective novel anesthetics in mice. Conclusions We demonstrate the first use of a high-throughput screen to successfully identify a novel anesthetic chemotype and show mammalian anesthetic activity for members of that chemotype. PMID:25603205

Cocaine-like discriminative stimulus effects of amphetamine, cathinone, methamphetamine, and their 3,4-methylenedioxy analogs in male rhesus monkeys

PubMed Central

Smith, Douglas A.; Blough, Bruce. E.; Banks, Matthew L.

2016-01-01

Rationale Synthetic cathinones have emerged as the newest class of abused monoamine transporter substrates. Structurally, these compounds are all beta-ketone amphetamine (cathinone) analogs. Whether synthetic cathinone analogs produce differential behavioral effects from their amphetamine analog counterparts has not been systematically examined. Preclinical drug discrimination procedures have been useful for determining the structure activity relationships (SAR) of abused drugs; however, direct comparisons between amphetamine and cathinone analogs are lacking and, in particular, in nonhuman primate models. Objectives The study aim was to determine the potency and time course of (±)-amphetamine, (±)-cathinone, (±)-methamphetamine, and their 3,4-methylenedioxy analogs (±)-MDA, (±)-MDC, and (±)-MDMA, respectively to produce cocaine-like discriminative stimulus effects. If cathinone analogs have similar behavioral pharmacological properties to their amphetamine counterparts, then we would predict similar potencies and efficacies to produce cocaine-like discriminative stimulus effects. Methods Male rhesus monkeys (n=4) were trained to discriminate intramuscular cocaine (0.32 mg/kg) from saline in a two-key food-reinforced discrimination procedure. Results Racemic amphetamine, cathinone, and methamphetamine produced dose-dependent and full, ≥90% cocaine-appropriate responding, in all monkeys. Addition of 3,4-methylenedioxy moiety attenuated both the potency and efficacy of amphetamine (MDA), cathinone (MDC), and methamphetamine (MDMA) to produce full cocaine-like effects. Moreover, the cocaine-like effects of amphetamine and cathinone were attenuated to a greater extent than methamphetamine or previously published methcathinone (Smith et al. 2016). Conclusion The presence of an N-methyl group blunted both the potency and efficacy shift of the 3,4-methylenedioxy addition for both amphetamine and cathinone analogs. PMID:27709249

Quantitative structure - mesothelioma Potency Model Optimization for Complex Mixtures of Elongated Particles in Rat Pleura

EPA Science Inventory

Cancer potencies of mineral and synthetic elongated particle (EP) mixtures, including fibers from asbestos, are influenced by changes in fiber dose composition, bioavailability and biodurability in combination with relevant cytotoxic dose-response relationships. A unique and com...

Steroselective Potencies and Relative Toxicities of Coniine Enantiomers

USDA-ARS?s Scientific Manuscript database

Coniine, one of the major toxic alkaloids present in poison hemlock (Conium maculatum), occurs in two optically active forms. A comparison of the relative potencies of (+)- and (-)-coniine enantiomers has not been previously reported. In this study, we separated the enantiomers of coniine and dete...

Stereoselective potencies and relative toxicities of y-Coniceine and N-Methylconiine enantiomers

USDA-ARS?s Scientific Manuscript database

'-Coniceine, coniine, and N-methylconiine are toxic alkaloids present in poison hemlock (Conium maculatum). We previously reported the comparison of the relative potencies of (+)- and (-)-coniine enantiomers. In this study, we synthesized '-coniceine and the enantiomers of N-methylconiine and dete...

CUMULATIVE RISK ASSESSMENT FOR QUANTITATIVE RESPONSE DATA

EPA Science Inventory

The Relative Potency Factor approach (RPF) is used to normalize and combine different toxic potencies among a group of chemicals selected for cumulative risk assessment. The RPF method assumes that the slopes of the dose-response functions are all equal; but this method depends o...

21 CFR 640.104 - Potency.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the Center for Biologics Evaluation and Research, Food and Drug Administration, as indicated in... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Potency. 640.104 Section 640.104 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL...

21 CFR 640.104 - Potency.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the Center for Biologics Evaluation and Research, Food and Drug Administration, as indicated in... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Potency. 640.104 Section 640.104 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL...

The effect of electrical lighting power and irradiance on indoor-grown cannabis potency and yield.

PubMed

Potter, David J; Duncombe, Paul

2012-05-01

The floral development and potencies [Δ(9) -tetrahydrocannabinol (THC) contents] of cannabis plants were compared when grown indoors under high-pressure sodium lamps consuming electrical power at three densities (270, 400, and 600 W/m(2)). After a 3-week vegetative phase, plants were grown for 8 weeks, with lamps maintaining an artificial day length of 12 h. Foliar and floral yields were measured. Gas chromatography was used to measure the content of the psychoactive cannabinoid THC. Mean yields per unit of electrical power in each lighting regime ranged from 0.9 to 1.6 g/W, the highest being achieved in the lowest irradiance regime. The individual potencies of the separated leaf and flower materials were not affected by increasing irradiance. However, there was a corresponding increase in the overall potency of the aerial plant tissue. This was because of the plants in brighter conditions producing a higher proportion of floral material. © 2011 American Academy of Forensic Sciences.

USDA regulatory guidelines and practices for veterinary Leptospira vaccine potency testing.

PubMed

Srinivas, G B; Walker, A; Rippke, B

2013-09-01

Batch-release potency testing of leptospiral vaccines licensed by the United States Department of Agriculture (USDA) historically was conducted through animal vaccination-challenge models. The hamster vaccination-challenge assay was Codified in 1974 for bacterins containing Leptospira pomona, Leptospira icterohaemorrhagiae, and Leptospira canicola, and in 1975 for bacterins containing Leptospira grippotyphosa. In brief, 10 hamsters are vaccinated with a specified dilution of bacterin. After a holding period, the vaccinated hamsters, as well as nonvaccinated controls, are challenged with virulent Leptospira and observed for mortality. Eighty percent of vaccinated hamsters must survive in the face of a valid challenge. The high cost of the Codified tests, in terms of monetary expense and animal welfare, prompted the Center for Veterinary Biologics (CVB) to develop ELISA alternatives for them. Potency tests for other serogroups, such as Leptospira hardjo-bovis, that do not have Codified requirements for potency testing continue to be examined on a case-by-case basis. Published by Elsevier Ltd.

Scientific Issues Relevant to Setting Regulatory Criteria to Identify Endocrine-Disrupting Substances in the European Union.

PubMed

Slama, Rémy; Bourguignon, Jean-Pierre; Demeneix, Barbara; Ivell, Richard; Panzica, Giancarlo; Kortenkamp, Andreas; Zoeller, R Thomas

2016-10-01

Endocrine disruptors (EDs) are defined by the World Health Organization (WHO) as exogenous compounds or mixtures that alter function(s) of the endocrine system and consequently cause adverse effects in an intact organism, or its progeny, or (sub)populations. European regulations on pesticides, biocides, cosmetics, and industrial chemicals require the European Commission to establish scientific criteria to define EDs. We address the scientific relevance of four options for the identification of EDs proposed by the European Commission. Option 1, which does not define EDs and leads to using interim criteria unrelated to the WHO definition of EDs, is not relevant. Options 2 and 3 rely on the WHO definition of EDs, which is widely accepted by the scientific community, with option 3 introducing additional categories based on the strength of evidence (suspected EDs and endocrine-active substances). Option 4 adds potency to the WHO definition, as a decision criterion. We argue that potency is dependent on the adverse effect considered and is scientifically ambiguous, and note that potency is not used as a criterion to define other particularly hazardous substances such as carcinogens and reproductive toxicants. The use of potency requires a context that goes beyond hazard identification and corresponds to risk characterization, in which potency (or, more relevantly, the dose-response function) is combined with exposure levels. There is scientific agreement regarding the adequacy of the WHO definition of EDs. The potency concept is not relevant to the identification of particularly serious hazards such as EDs. As is common practice for carcinogens, mutagens, and reproductive toxicants, a multi-level classification of ED based on the WHO definition, and not considering potency, would be relevant (corresponding to option 3 proposed by the European Commission). Slama R, Bourguignon JP, Demeneix B, Ivell R, Panzica G, Kortenkamp A, Zoeller RT. 2016. Scientific issues relevant to setting regulatory criteria to identify endocrine disrupting substances in the European Union. Environ Health Perspect 124:1497-1503; http://dx.doi.org/10.1289/EHP217.

Scientific Issues Relevant to Setting Regulatory Criteria to Identify Endocrine-Disrupting Substances in the European Union

PubMed Central

Slama, Rémy; Bourguignon, Jean-Pierre; Demeneix, Barbara; Ivell, Richard; Panzica, Giancarlo; Kortenkamp, Andreas; Zoeller, R. Thomas

2016-01-01

Background: Endocrine disruptors (EDs) are defined by the World Health Organization (WHO) as exogenous compounds or mixtures that alter function(s) of the endocrine system and consequently cause adverse effects in an intact organism, or its progeny, or (sub)populations. European regulations on pesticides, biocides, cosmetics, and industrial chemicals require the European Commission to establish scientific criteria to define EDs. Objectives: We address the scientific relevance of four options for the identification of EDs proposed by the European Commission. Discussion: Option 1, which does not define EDs and leads to using interim criteria unrelated to the WHO definition of EDs, is not relevant. Options 2 and 3 rely on the WHO definition of EDs, which is widely accepted by the scientific community, with option 3 introducing additional categories based on the strength of evidence (suspected EDs and endocrine-active substances). Option 4 adds potency to the WHO definition, as a decision criterion. We argue that potency is dependent on the adverse effect considered and is scientifically ambiguous, and note that potency is not used as a criterion to define other particularly hazardous substances such as carcinogens and reproductive toxicants. The use of potency requires a context that goes beyond hazard identification and corresponds to risk characterization, in which potency (or, more relevantly, the dose–response function) is combined with exposure levels. Conclusions: There is scientific agreement regarding the adequacy of the WHO definition of EDs. The potency concept is not relevant to the identification of particularly serious hazards such as EDs. As is common practice for carcinogens, mutagens, and reproductive toxicants, a multi-level classification of ED based on the WHO definition, and not considering potency, would be relevant (corresponding to option 3 proposed by the European Commission). Citation: Slama R, Bourguignon JP, Demeneix B, Ivell R, Panzica G, Kortenkamp A, Zoeller RT. 2016. Scientific issues relevant to setting regulatory criteria to identify endocrine disrupting substances in the European Union. Environ Health Perspect 124:1497–1503; http://dx.doi.org/10.1289/EHP217 PMID:27108591

Preliminary Development of a Multidimensional Semantic Patient Experience Measurement Questionnaire.

PubMed

Kleiss, James A

2016-10-01

The purpose of this research was to assess the utility and reliability of a multidimensional patient experience measurement questionnaire in a clinical setting. Patient experience has emerged as an important metric for quality of healthcare. A number of separate concepts have been used to measure patient experience, but psychological research suggests that subjective experience is actually a composite of several independent concepts including: (a) evaluation/valence, (b) potency/control, (c) activity/arousal, and (d) novelty. The present research evaluates the reliability of a multidimensional patient experience measurement questionnaire in a clinical setting. A multidimensional semantic differential questionnaire was developed to measure the four underlying semantic dimensions of patient experience mentioned above. A group of 60 patients used the questionnaire to assess prescan expectations and postscan experience of a magnetic resonance scan. Data for one patient were deleted because their scan was interrupted. Results revealed more positive evaluation/valence, higher potency/control, and lower activity/arousal for postscan ratings compared to prescan expectations. Ratings of novelty were neutral in both the prescan and the postscan conditions. Subsequent analysis suggested that internal consistency for some concepts could be improved by replacing several specific rating scales. Present results provide evidence of the utility and reliability of a multidimensional semantic questionnaire for measuring patient experience in an actual clinical setting. Recommendations to improve internal consistency for the concepts potency/control, activity/arousal, and novelty were also provided. © The Author(s) 2016.

Inhibition of glycine receptor function of native neurons by aliphatic n-alcohols

PubMed Central

Tao, Liang; Ye, Jiang Hong

2002-01-01

The inhibitory effects of n-alcohols (methanol to dodecanol) on glycine-activated currents were studied in neurons freshly dissociated from the ventral tegmental area of neonatal rats using whole-cell patch-clamp recording technique.Ethanol enhanced and depressed glycine-activated currents in 35% and 45%, respectively, of neurons of ventral tegmental area of neonatal rats. In this report, we extended our focus of ethanol-induced inhibition of glycine currents to other straight-chain alcohols.Aliphatic n-alcohols, which have carbon numbers less than nine, suppressed glycine currents in 45% (71/158) of the neurons. All results from this study are obtained from the 45% of cells displaying inhibition; the other 55% of the neurons were not studied.Alcohol potency increased as the number of carbon atoms increased from one to five, and was at a maximal plateau from five to nine; alcohols with 10 or more carbons did not inhibit glycine-activated currents. Thus, a ‘cutoff' point in their potency for inhibition of glycine receptor function occurred at about decanol.A coapplication of dodecanol with ethanol eliminated the inhibition resulting from ethanol. Thus, dodecanol may bind to the receptor silently and compete with ethanol.These observations indicate that straight-chain n-alcohols exhibit a ‘cutoff' point in their potency for inhibition of the glycine receptor function between nine and 10 carbon atoms. The inability of longer alcohols to change the activation properties of the receptors may contribute to the cutoff effect. PMID:12055142

Structure-activity relationship studies on quinoxalin-2(1H)-one derivatives containing thiazol-2-amine against hepatitis C virus leading to the discovery of BH6870.

PubMed

Zhong, Qi-Fei; Liu, Rui; Liu, Gang

2015-11-01

Chronic hepatitis C virus infection represents a serious global public health problem, typically resulting in fibrosis, cirrhosis, and ultimately hepatocellular carcinoma. Based on our previous discovery of lead compound 2 (Liu et al. J Med Chem 54:5747-5768, 2011), 35 new quinoxalinone derivatives were explored in this study. Outline of the structure-activity relationships (SARs) revealed that compound BH6870 (36) showed high anti-HCV potency ([Formula: see text]) and a good cell safety index (SI [Formula: see text]). SARs analysis indicated that quinoxalin-2(1H)-one containing a 4-aryl-substituted thiazol-2-amine moiety was optimal for antiviral activity. Introducing a hydrogen-bond acceptor (such as ester or amide group) at the C-3 position of quinoxalin-2(1H)-one was beneficial for the antiviral potency, and especially, N,N-disubstituted amide was far superior to N-monosubstituted amide. Incorporation of more than one halogen (fluorine or chlorine atom) or a strong electron-withdrawing group on the benzene ring of the thiazole-phenyl moiety might reduce electron atmosphere density further and resulted in a dramatical loss of activity. The NH-group of the lactam moiety was clearly required for anti-HCV activity. Design and synthesis of quinoxalin-2(1H)-one derivatives as new non-nucleoside small-molecule HCV inhibitors. BH6870 (36), showing higher antiviral potency and a good cell safety index, was identified.

ALTERNATIVE APPROACH TO ESTIMATING CANCER ...

EPA Pesticide Factsheets

The alternative approach for estimating cancer potency from inhalation exposure to asbestos seeks to improve the methods developed by USEPA (1986). This efforts seeks to modify the the current approach for estimating cancer potency for lung cancer and mesothelioma to account for the current scientific consensus that cancer risk from asbestos depends both on mineral type and on particle size distribution. In brief, epidemiological exposure-response data for lung cancer and mesothelioma in asbestos workers are combined with estimates of the mineral type(s) and partical size distribution at each exposure location in order to estimate potency factors that are specific to a selected set of mineral type and size

Evaluation of the potential carcinogenicity of 4-chloro-o-toluidine hydrochloride (3165-93-3). Final report

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

Not Available

1988-06-01

4-Chloro-o-toluidine hydrochloride is a probable human carcinogen, classified as weight-of-evidence Group B2 under the EPA Guidelines for Carcinogen Risk Assessment. Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is No Data. The potency factor (F) for 4-chloro-o-toluidine hydrochloride is estimated to be 0.40 (mg/kg/day)(-1), placing it in potency group 3 according to the CAG's methodology for evaluating potential carcinogens. Combining the weight-of-evidence group and the potency group, 4-chloro-o-toluidine hydrochloride is assigned a LOW hazard ranking.

THE VALENCE AND METHYLATION STATE OF ARSENIC DETERMINES ITS POTENCY IN INTERACTION WITH THE MITOTIC APPARATUS

EPA Science Inventory

We have previously shown that the cytotoxic and genotoxic potency of arsenicals is dependent upon their valence and methylation state. Trivalent methylated arsenicals are much more potent DNA damaging agents than are their inorganic and pentavalent counterparts. Furthermore, thei...

77 FR 11536 - Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-27

... Categorization of Chemicals Causing Allergic Contact Dermatitis: Availability of Federal Agency Responses AGENCY... lymph node assay (LLNA) for potency categorization of chemicals causing allergic contact dermatitis (ACD... Local Lymph Node Assay for Potency Categorization of Chemicals Causing Allergic Contact Dermatitis in...

Quantitative structure - mesothelioma potency model optimization for complex mixtures of elongated particles in rat pleura: A retrospective study

EPA Science Inventory

Cancer potencies of mineral and synthetic elongated particle (EP) mixtures, including asbestos fibers, are influenced by changes in fiber dose composition, bioavailability, and biodurability in combination with relevant cytotoxic dose-response relationships. A unique and compreh...

TOWARDS A GENERIC PBPK MODEL OF PYRETHROID PESTICIDES: MODELING DELTAMETHRIN AND PERMETHIN IN THE RAT

EPA Science Inventory

Pyrethroids have emerged as a major class of insecticide due to their selective potency in insects and their relatively low potency in mammalian studies. Pyrethroids exert toxicity by binding to voltage-gated sodium channels, thereby eliciting excitatory neurotoxicity. The Food...

TOWARDS A GENERIC PBPK MODEL OF PYRETHROID PESTICIDES: MODELING DELTAMETHRIN AND PERMETHRIN IN THE RAT

EPA Science Inventory

Pyrethroids have emerged as a major class of insecticide due to their selective potency in insects and their relatively low potency in mammalian studies. Pyrethroids exert toxicity by binding to voltage-gated sodium channels, thereby eliciting excitatory neurotoxicity. The Fo...

Brine Shrimp Bioassays: A Useful Technique in Biological Investigations

ERIC Educational Resources Information Center

Rice, Stanley A.; Maness, Ian B.

2004-01-01

A technique to measure the potency of leaf compounds against herbivores with the use of a bioassay is described. Bioassays are useful in classes where students have career plans like medicine in which bioassays can be used as tools for screening plants for possible medicinal potency.

21 CFR 660.4 - Potency test.

Code of Federal Regulations, 2012 CFR

2012-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Antibody to Hepatitis B Surface Antigen § 660.4 Potency test. To be satisfactory for release, each filling of Antibody to Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Surface Antigen Panel and shall be sufficiently potent...

21 CFR 660.4 - Potency test.

Code of Federal Regulations, 2011 CFR

2011-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Antibody to Hepatitis B Surface Antigen § 660.4 Potency test. To be satisfactory for release, each filling of Antibody to Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Surface Antigen Panel and shall be sufficiently potent...

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2014 CFR

2014-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test. To be satisfactory for release, each filling of Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Antiserum Panel and shall be sufficiently potent to be able to detect the...

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2011 CFR

2011-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test. To be satisfactory for release, each filling of Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Antiserum Panel and shall be sufficiently potent to be able to detect the...

21 CFR 660.4 - Potency test.

Code of Federal Regulations, 2014 CFR

2014-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Antibody to Hepatitis B Surface Antigen § 660.4 Potency test. To be satisfactory for release, each filling of Antibody to Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Surface Antigen Panel and shall be sufficiently potent...

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2012 CFR

2012-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test. To be satisfactory for release, each filling of Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Antiserum Panel and shall be sufficiently potent to be able to detect the...

9 CFR 113.8 - In vitro tests for serial release.

Code of Federal Regulations, 2010 CFR

2010-01-01

....8 Section 113.8 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... Health Inspection Service (APHIS); (3) Establishing satisfactory potency for the product in accordance... potency test by Animal and Plant Health Inspection Service as provided in this paragraph. Products shall...

21 CFR 660.4 - Potency test.

Code of Federal Regulations, 2010 CFR

2010-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Antibody to Hepatitis B Surface Antigen § 660.4 Potency test. To be satisfactory for release, each filling of Antibody to Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Surface Antigen Panel and shall be sufficiently potent...

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2010 CFR

2010-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test. To be satisfactory for release, each filling of Hepatitis B Surface Antigen shall be tested against the Reference Hepatitis B Antiserum Panel and shall be sufficiently potent to be able to detect the...

TETRAMETHRIN AND DDT INHIBIT SPONTANEOUS FIRING IN CORTICAL NEURONAL NETWORKS

EPA Science Inventory

The insecticidal and neurotoxic effects of pyrethroids result from prolonged sodium channel inactivation, which causes alterations in neuronal firing and communication. Previously, we determined the relative potencies of 11 type I and type II pyrethroid insecticides using microel...

INDUCTION OF TRISOMICS BY PLATINUM DIAMINODINITRODICHLORIDE

EPA Science Inventory

Trisomics were produced in the pollen mother cells of Pennisetum americanum (L) K. Schum plants resulting from seeds treated with M to the minus 6th power platinum diaminodinitrodichloride. On the basis of the preliminary study the relative potency of cis-Platinum diaminodinitrod...

Potential bronchoconstrictor stimuli in acid fog.

PubMed Central

Balmes, J R; Fine, J M; Gordon, T; Sheppard, D

1989-01-01

Acid fog is complex and contains multiple stimuli that may be capable of inducing bronchoconstriction. These stimuli include sulfuric and niric acids, the principal inorganic acids present; sulfites, formed in the atmosphere as a reaction product of sulfur dioxide and water droplets; fog water itself, a hypoosmolar aerosol; the organic acid hydroxymethanesulfonate, the bisulfite adduct of formaldehyde; and gaseous pollutants, e.g., sulfur dioxide, oxides of nitrogen, ozone. Given this complexity, evaluation of the respiratory health effects of naturally occurring acid fog requires assessment of the bronchoconstrictor potency of each component stimulus and possible interactions among these stimuli. We summarize the results of three studies that involve characterization of the bronchoconstrictor potency of acid fog stimuli and/or their interaction in subjects with asthma. The results of the first study indicate that titratable acidity appears to be a more important stimulus to bronchoconstriction than is pH. The results of the second study demonstrate that sulfite species are capable of inducing bronchoconstriction, especially when inhaled at acid pH. The results of the third study suggest that acidity can potentiate hypoosmolar fog-induced bronchoconstriction. PMID:2539989

Effect-directed analysis to explore the polar bear exposome: identification of thyroid hormone disrupting compounds in plasma.

PubMed

Simon, Eszter; van Velzen, Martin; Brandsma, Sicco H; Lie, Elisabeth; Løken, Katharina; de Boer, Jacob; Bytingsvik, Jenny; Jenssen, Bjørn M; Aars, Jon; Hamers, Timo; Lamoree, Marja H

2013-08-06

Compounds with transthyretin (TTR)-binding potency in the blood plasma of polar bear cubs were identified with effect-directed analysis (EDA). This approach contributes to the understanding of the thyroid disrupting exposome of polar bears. The selection of these samples for in-depth EDA was based on the difference between the observed TTR-binding potency on the one hand and the calculated potency (based on known concentrations of TTR-binding compounds and their relative potencies) on the other. A library-based identification was applied to the liquid chromatography-time-of-flight-mass spectrometry (LC-ToF-MS) data by screening for matches between compound lists and the LC-ToF-MS data regarding accurate mass and isotope pattern. Then, isotope cluster analysis (ICA) was applied to the LC-ToF-MS data allowing specific screening for halogen isotope patterns. The presence of linear and branched nonylphenol (NP) was observed for the first time in polar bears. Furthermore, the presence of one di- and two monohydroxylated octachlorinated biphenyls (octaCBs) was revealed in the extracts. Linear and branched NP, 4'-OH-CB201 and 4,4'-OH-CB202 could be successfully confirmed with respect to their retention time in the analytical system. In addition, branched NP, mono- and dihydroxylated-octaCBs showed TTR-binding potencies and could explain another 32 ± 2% of the total measured activities in the extracts.

CRISPR/Cas9-mediated gene knockout is insensitive to target copy number but is dependent on guide RNA potency and Cas9/sgRNA threshold expression level

PubMed Central

Yuen, Garmen; Khan, Fehad J.; Gao, Shaojian; Stommel, Jayne M.; Batchelor, Eric; Wu, Xiaolin

2017-01-01

Abstract CRISPR/Cas9 is a powerful gene editing tool for gene knockout studies and functional genomic screens. Successful implementation of CRISPR often requires Cas9 to elicit efficient target knockout in a population of cells. In this study, we investigated the role of several key factors, including variation in target copy number, inherent potency of sgRNA guides, and expression level of Cas9 and sgRNA, in determining CRISPR knockout efficiency. Using isogenic, clonal cell lines with variable copy numbers of an EGFP transgene, we discovered that CRISPR knockout is relatively insensitive to target copy number, but is highly dependent on the potency of the sgRNA guide sequence. Kinetic analysis revealed that most target mutation occurs between 5 and 10 days following Cas9/sgRNA transduction, while sgRNAs with different potencies differ by their knockout time course and by their terminal-phase knockout efficiency. We showed that prolonged, low level expression of Cas9 and sgRNA often fails to elicit target mutation, particularly if the potency of the sgRNA is also low. Our findings provide new insights into the behavior of CRISPR/Cas9 in mammalian cells that could be used for future improvement of this platform. PMID:29036671

CRISPR/Cas9-mediated gene knockout is insensitive to target copy number but is dependent on guide RNA potency and Cas9/sgRNA threshold expression level.

PubMed

Yuen, Garmen; Khan, Fehad J; Gao, Shaojian; Stommel, Jayne M; Batchelor, Eric; Wu, Xiaolin; Luo, Ji

2017-11-16

CRISPR/Cas9 is a powerful gene editing tool for gene knockout studies and functional genomic screens. Successful implementation of CRISPR often requires Cas9 to elicit efficient target knockout in a population of cells. In this study, we investigated the role of several key factors, including variation in target copy number, inherent potency of sgRNA guides, and expression level of Cas9 and sgRNA, in determining CRISPR knockout efficiency. Using isogenic, clonal cell lines with variable copy numbers of an EGFP transgene, we discovered that CRISPR knockout is relatively insensitive to target copy number, but is highly dependent on the potency of the sgRNA guide sequence. Kinetic analysis revealed that most target mutation occurs between 5 and 10 days following Cas9/sgRNA transduction, while sgRNAs with different potencies differ by their knockout time course and by their terminal-phase knockout efficiency. We showed that prolonged, low level expression of Cas9 and sgRNA often fails to elicit target mutation, particularly if the potency of the sgRNA is also low. Our findings provide new insights into the behavior of CRISPR/Cas9 in mammalian cells that could be used for future improvement of this platform. Published by Oxford University Press on behalf of Nucleic Acids Research 2017.

Aryl hydrocarbon receptor-mediated toxic potency of dissolved lipophilic organic contaminants collected from Lincoln Creek, Milwaukee, Wisconsin, USA, to PLHC-1 (Poeciliopsis lucida) fish hepatoma cells

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

Villeneuve, D.L.; Crunkilton, R.L.; DeVita, W.M.

1997-05-01

Lincoln Creek is a severely degraded urban stream located in Milwaukee County, Wisconsin, USA. As part of a comprehensive study on effects of urban storm water runoff on the stream biota, an in vitro bioassay with PLHC-1 (Poeciliopsis lucida) fish hepatoma cells was used to assess potential toxic potency of aryl hydrocarbon receptor (AhR)-active compounds, collected by semipermeable membrane devices (SPMDs) exposed to Lincoln Creek water. Dialysates from SPMDs exposed to Lincoln Creek water caused marked cytochrome P4501A induction in PLHC-1. Toxic potency of dialysates, expressed as bioassay-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ) ranged from 1,300 to 6,600 pg TCDD-EQ/g SPMD formore » 14-d exposures. Dialysates from SPMDs exposed to stream water at base flow had potencies consistently lower than those exposed to storm-flow (high-flow) events that occurred during the same 14-d period. Polychlorinated biphenyls were not detectable in the dialysates. Gas chromatography-mass spectrometry analysis identified polycyclic aromatic hydrocarbons (PAHs) as major contaminants in the dialysates. A log-log correlation of total PAHs and TCDD-EQ yielded an r{sup 2} of 0.802. Empirical evidence suggests that AhR-active PAHs can account for about 20 to 50% of the potency observed.« less

Probing the inhibitory potency of epigallocatechin gallate against human γB-crystallin aggregation: Spectroscopic, microscopic and simulation studies

NASA Astrophysics Data System (ADS)

Chaudhury, Susmitnarayan; Dutta, Anirudha; Bag, Sudipta; Biswas, Pranandita; Das, Amit Kumar; Dasgupta, Swagata

2018-03-01

Aggregation of human ocular lens proteins, the crystallins is believed to be one of the key reasons for age-onset cataract. Previous studies have shown that human γD-crystallin forms amyloid like fibres under conditions of low pH and elevated temperature. In this article, we have investigated the aggregation propensity of human γB-crystallin in absence and presence of epigallocatechin gallate (EGCG), in vitro, when exposed to stressful conditions. We have used different spectroscopic and microscopic techniques to elucidate the inhibitory effect of EGCG towards aggregation. The experimental results have been substantiated by molecular dynamics simulation studies. We have shown that EGCG possesses inhibitory potency against the aggregation of human γB-crystallin at low pH and elevated temperature.

All-trans-retinoic acid enhances apoptosis induction by tyrosine kinase inhibitors in the eosinophilic leukemia-derived EoL-1 cell line.

PubMed

Robert, Carine; Apàti, Agota; Chomienne, Christine; Papp, Béla

2008-02-01

Imatinib and retinoids induce apoptosis in FIP1L1/PDGFRalpha-positive EoL-1 leukemia cells. Although imatinib induces complete remission in most FIP1L1/PDGFRalpha-positive patients, response to imatinib is sometimes suboptimal. In order to enhance the potency of the molecularly targeted therapy of eosinophilic leukemia, we investigated the effect of retinoids combined with tyrosine kinase inhibitors on EoL-1 cells. We demonstrate that retinoids combined with tyrosine kinase inhibitors lead to enhanced apoptosis induction in EoL-1 cells. Our results suggest that tyrosine kinase inhibitors combined with retinoids may constitute a valuable therapeutic approach for sensitive neoplasias that may display enhanced anti-leukemic potency when compared to single drug treatments.

Angiogenic potency of Amadori-glycated phosphatidylethanolamine.

PubMed

Nakagawa, Kiyotaka; Oak, Jeong-Ho; Miyazawa, Teruo

2005-06-01

Glycation has been thought to participate in diabetic vascular diseases. However, there are no reports about the effects of lipid glycation on endothelial dysfunction. In this study, we have evaluated whether Amadori-glycated phosphatidylethanolamine (Amadori-PE), a lipid-linked glycation compound, affected proliferation, migration, and tube formation of cultured human umbilical vein endothelial cells. These three factors involved in angiogenesis were significantly stimulated by Amadori-PE at a low concentration of less than 5 microM. Furthermore, Amadori-PE also stimulated the secretion of matrix metalloproteinase-2 (MMP-2), a pivotal enzyme in the initial step of angiogenesis. Our results indicated for the first time that Amadori-PE would elicit vascular disease through angiogenic potency on endothelial cells, thereby playing an active part in the development and progression of diabetic microangiopathy.

Acute toxic tests of rainwater samples using Daphnia magna.

PubMed

Sakai, Manabu

2006-06-01

Rainwater samples were collected at Isogo Ward of Yokohama City, Japan, from 23 June to 31 July 2003. The toxic potency of pollutants present in 13 rainwater samples was tested using Daphnia magna. Most test animals died within 48 h in five test solutions that were prepared from rainwater samples. On the other hand, when nonpolar compounds such as pesticides were removed from rainwater samples before the toxic tests, mortalities in all test solutions were less than 10%. Eight kinds of pesticides were detected in rainwater samples. The highest concentration was of dichlorvos, at 0.74 microg/L. Results indicated that insecticides in rainwater sometimes lethally affected D. magna and that toxic potency of insecticides that are present in rainwater constitutes an important problem for environmental protection.

Collaborative study for the establishment of the 2(nd) International Standard for Bleomycin Complex A2/B2.

PubMed

Jorajuria, S; Raphalen, C; Dujardin, V; Daas, A

2015-01-01

Organization (WHO) International Standard (IS) for bleomycin complex A2/B2. Eight laboratories from different countries participated. Potencies of the candidate material were estimated by microbiological assays with sensitive micro-organisms. To ensure continuity between consecutive batches, the 1(st) IS for bleomycin complex A2/B2 was used as a reference. Based on the results of the study, the 2(nd) IS for bleomycin complex A2/B2 was adopted at the meeting of the WHO Expert Committee for Biological Standardization (ECBS) in 2014 with an assigned potency of 12 500 International Units (IU) per vial. The 2(nd) IS for bleomycin complex A2/B2 is available from the European Directorate for the Quality of Medicines & HealthCare (EDQM).

The Joint Task Force Structure as a Model for Homeland Security

DTIC Science & Technology

2013-05-20

was the primary entry point for high potency marijuana and 3,4-MethyleneDioxy-n- MethylAmphetamine, ( MDMA ) known as Ecstasy bound for New York and New...into mainland Canada. Smuggling activity increased further with the rise in popularity of high potency hydroponically grown marijuana and MDMA

High Potency and Other Alcoholic Beverage Consumption among Adolescents

ERIC Educational Resources Information Center

Jobli, Edessa C.; Dore, Heather S.; Werch, Chudley E.; Moore, Michele J.

2005-01-01

This study examined the prevalence of high potency (liquor, malt liquor, fortified wine) and other alcoholic beverage consumption (beer, wine/wine coolers) among adolescents, the impact of gender and ethnicity, and the risk and protective factors that predicted consumption. A confidential survey revealed that, among eighth grade students,…

Developing of Environmental Education Textbook Based on Local Potencies

ERIC Educational Resources Information Center

Ilma, Silfia; Wijarini, Fitri

2017-01-01

Environmental education subject aims to form students who have the character to maintain the environment. One effort to achieve the objectives of the Environmental education subject is the local Environmental Education Textbook Based on Local Potencies. This research was aimed to produce textbook of environment-based education subject…

Both Lymantria dispar nucleopolyhedrovirus enhancin genes contribute to viral potency

Treesearch

Holly J.R. Popham; David S. Bischoff; James M. Slavicek

2001-01-01

Enhancins are a group of proteins first identified in granuloviruses (GV) that have the ability to enhance nuclear polyhedrosis virus potency. We had previously identified an enhancin gene (E1) in the Lymantria dispar multinucleocapsid nucleopolyhedrovirus (LdMNPV) (D.S. Bischoff and J.M. Slavicek, J. Virol. 71:...

Comparative Elongated Mineral Particle Toxicology & Erionite’s Apparent  High Potency for Inducing Mesothelioma

EPA Science Inventory

Recent NHEERL research under EPA's Libby Action Plan has determined that elongated particle relative potency for rat pleural mesothelioma is best predicted on the basis of total external surface area (TSA) of slightly acid leached test samples which simulate particle bio-durabili...

Development of Quantitative Structure-Activity Relationship (QSAR) Models to Predict the Carcinogenic Potency of Chemicals

EPA Science Inventory

Determining the carcinogenicity and carcinogenic potency of new chemicals is both a labor-intensive and time-consuming process. In order to expedite the screening process, there is a need to either: (1) identify alternative toxicity measures (shorter duration) that may be used as...

A CONCEPTUAL MODEL FOR EVALUATING RELATIVE POTENCY DATA FOR USE IN ECOLOGICAL RISK ASSESSMENTS

EPA Science Inventory

For chemicals with a common mechanism of toxicity, relative potency factors (RPFs) allow dose and exposure measures to be normalized to an equivalent toxicity amount of a model chemical... In ecological risk assessments the large number of possible target species, variety of expo...

The botulinum toxin LD50 potency assay - another chapter, another mystery.

PubMed

Pickett, Andy

2012-09-01

Observers of the potency assay used for botulinum toxin were greeted last year with the news that one company had an alternative, non-animal alternative in place. But all was not as it seemed from the press release, and over a year later, information is still lacking.

Characterization of angiotensin-I converting enzyme inhibiting peptide from Venerupis philippinarum with nano-liquid chromatography in combination with orbitrap mass spectrum detection and molecular docking

NASA Astrophysics Data System (ADS)

Shi, Lei; Wu, Tizhi; Sheng, Naijuan; Yang, Li; Wang, Qian; Liu, Rui; Wu, Hao

2017-06-01

The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-I converting enzyme (ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-I-inhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC50 of 5.75 μmol L-1. The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.

In silico screening of small molecule libraries using the dengue virus envelope E protein has identified compounds with antiviral activity against multiple flaviviruses.

PubMed

Kampmann, Thorsten; Yennamalli, Ragothaman; Campbell, Phillipa; Stoermer, Martin J; Fairlie, David P; Kobe, Bostjan; Young, Paul R

2009-12-01

The flaviviruses comprise a large group of related viruses, many of which pose a significant global human health threat, most notably the dengue viruses (DENV), West Nile virus (WNV) and yellow fever virus (YFV). Flaviviruses enter host cells via fusion of the viral and cellular membranes, a process mediated by the major viral envelope protein E as it undergoes a low pH induced conformational change in the endosomal compartment of the host cell. This essential entry stage in the flavivirus life cycle provides an attractive target for the development of antiviral agents. We performed an in silico docking screen of the Maybridge chemical database within a previously described ligand binding pocket in the dengue E protein structure that is thought to play a key role in the conformational transitions that lead to membrane fusion. The biological activity of selected compounds identified from this screen revealed low micromolar antiviral potency against dengue virus for two of the compounds. Our results also provide the first evidence that compounds selected to bind to this ligand binding site on the flavivirus E protein abrogate fusion activity. Interestingly, one of these compounds also has antiviral activity against both WNV (kunjin strain) and YFV.

Is skin penetration a determining factor in skin sensitization ...

EPA Pesticide Factsheets

Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW 1 is a true requirement for sensitisation.Methods. A large dataset of substances that had been evaluated for their skin sensitisation potential, together with measured LogKow values was compiled from the REACH database. The incidence of skin sensitisers relative to non-skin sensitisers below and above the LogKow = 1 threshold was evaluated. Results. 1482 substances with associated skin sensitisation outcomes and measured LogKow values were identified. 305 substances had a measured LogKow < 0 and of those, 38 were sensitisers.Conclusions. There was no significant difference in the incidence of skin sensitisation above and below the LogKow = 1 threshold. Reaction chemistry considerations could explain the skin sensitisation observed for the 38 sensitisers with a LogKow < 0. The LogKow threshold is a self-evident truth borne out from the widespread misconception that the ability to efficiently penetrate the stratum corneum is a key determinant of skin sensitisation potential and potency. Using the REACH data extracted to test out the validity of common assumptions in the skin sensitization AOP. Builds on trying to develop a proof of concept IATA

Problem Solving Interventions for Diabetes Self-management and Control: A Systematic Review of the Literature

PubMed Central

Fitzpatrick, Stephanie L.; Schumann, Kristina P.; Hill-Briggs, Felicia

2013-01-01

Aims Problem solving is deemed a core skill for patient diabetes self-management education. The purpose of this systematic review is to examine the published literature on the effect of problem-solving interventions on diabetes self-management and disease control. Data Sources We searched PubMed and PsychINFO electronic databases for English language articles published between November 2006 and September 2012. Reference lists from included studies were reviewed to capture additional studies. Study Selection Studies reporting problem-solving intervention or problem solving as an intervention component for diabetes self-management training and disease control were included. Twenty-four studies met inclusion criteria. Data Extraction Study design, sample characteristics, measures, and results were reviewed. Data Synthesis Sixteen intervention studies (11 adult, 5 children/adolescents) were randomized controlled trials, and 8 intervention studies (6 adult, 2 children/adolescents) were quasi-experimental designs. Conclusions Studies varied greatly in their approaches to problem-solving use in patient education. To date, 36% of adult problem-solving interventions and 42% of children/adolescent problem-solving interventions have demonstrated significant improvement in HbA1c, while psychosocial outcomes have been more promising. The next phase of problem-solving intervention research should employ intervention characteristics found to have sufficient potency and intensity to reach therapeutic levels needed to demonstrate change. PMID:23312614

Predicting the toxicity of metal mixtures

USGS Publications Warehouse

Balistrieri, Laurie S.; Mebane, Christopher A.

2013-01-01

The toxicity of single and multiple metal (Cd, Cu, Pb, and Zn) solutions to trout is predicted using an approach that combines calculations of: (1) solution speciation; (2) competition and accumulation of cations (H, Ca, Mg, Na, Cd, Cu, Pb, and Zn) on low abundance, high affinity and high abundance, low affinity biotic ligand sites; (3) a toxicity function that accounts for accumulation and potency of individual toxicants; and (4) biological response. The approach is evaluated by examining water composition from single metal toxicity tests of trout at 50% mortality, results of theoretical calculations of metal accumulation on fish gills and associated mortality for single, binary, ternary, and quaternary metal solutions, and predictions for a field site impacted by acid rock drainage. These evaluations indicate that toxicity of metal mixtures depends on the relative affinity and potency of toxicants for a given aquatic organism, suites of metals in the mixture, dissolved metal concentrations and ratios, and background solution composition (temperature, pH, and concentrations of major ions and dissolved organic carbon). A composite function that incorporates solution composition, affinity and competition of cations for two types of biotic ligand sites, and potencies of hydrogen and individual metals is proposed as a tool to evaluate potential toxicity of environmental solutions to trout.

The higher barrier of darunavir and tipranavir resistance for HIV-1 protease

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

Wang, Yong; Liu, Zhigang; Brunzelle, Joseph S.

2011-11-17

Darunavir and tipranavir are two inhibitors that are active against multi-drug resistant (MDR) HIV-1 protease variants. In this study, the invitro inhibitory efficacy was tested against a MDR HIV-1 protease variant, MDR 769 82T, containing the drug resistance mutations of 46L/54V/82T/84V/90M. Crystallographic and enzymatic studies were performed to examine the mechanism of resistance and the relative maintenance of potency. The key findings are as follows: (i) The MDR protease exhibits decreased susceptibility to all nine HIV-1 protease inhibitors approved by the US Food and Drug Administration (FDA), among which darunavir and tipranavir are the most potent; (ii) the threonine 82more » mutation on the protease greatly enhances drug resistance by altering the hydrophobicity of the binding pocket; (iii) darunavir or tipranavir binding facilitates closure of the wide-open flaps of the MDR protease; and (iv) the remaining potency of tipranavir may be preserved by stabilizing the flaps in the inhibitor-protease complex while darunavir maintains its potency by preserving protein main chain hydrogen bonds with the flexible P2 group. These results could provide new insights into drug design strategies to overcome multi-drug resistance of HIV-1 protease variants.« less

Effect of carboxyl-reduced heparin on the growth inhibition of bovine pulmonary artery smooth muscle cells

PubMed Central

G.Garg, Hari; Mrabat, Hicham; Yu, Lunyin; Freeman, Craig; Li, Boyangzi; Zhang, Fuming; Linhardt, Robert J.; Hales, Charles A.

2010-01-01

Heparin (HP) inhibits the proliferation of bovine pulmonary artery smooth muscle cells (BPASMC's), among other cell types in vitro. In order to develop a potential therapeutic agent to reverse vascular remodeling, we are involved in deciphering the relationship between the native HP structure and its antiproliferative potency. We have previously reported the influence of the molecular size and the effects of various O-sulfo and N-acetyl groups of HP on growth-inhibitory activity. In this study, to understand the influence of carboxyl groups in the HP structure required for endogenous activity, a chemically modified derivative of native HP was prepared by converting the carboxyl groups of hexuronic acid residues in HP to primary hydroxyl groups. This modification procedure involves the treatment of HP with N-(3-dimethylaminopropyl)-N-ethylcarbodiimide followed by reduction with NaBH4 to yield carboxyl-reduced heparin (CR-HP). When compared to the antiproliferative potency of native HP on cultured BPASMC's at three dose levels (1, 10, and 100 μg/mL), the CR-HP showed significantly less potency at all the doses. These results suggest that hexuronic acid residues in both major and variable sequences in HP are essential for the antiproliferative properties of native HP. PMID:20399420

Comparative in vitro study of the antimicrobial activities of different commercial antibiotic products of vancomycin

PubMed Central

2011-01-01

Background One of the most critical problems about antimicrobial therapy is the increasing resistance to antibiotics. Previous studies have shown that there is a direct relation between erroneous prescription, dosage, route, duration of the therapy and the antibiotics resistance. Other important point is the uncertainty about the quality of the prescribed medicines. Some physicians believe that generic drugs are not as effective as innovator ones, so it is very important to have evidence that shows that all commercialized drugs are suitable for therapeutic use. Methods Microbial assays were used to establish the potency, the Minimal Inhibitory Concentrations (MICs), the Minimal Bactericidal Concentration (MBCs), the critical concentrations, and the production of spontaneous mutants that are resistant to vancomycin. Results The microbial assay was validated in order to determine the Vancomycin potency of the tasted samples. All the products showed that have potency values between 90 - 115% (USP requirement). The products behave similarly because the MICs, The MBCs, the critical concentrations, the critical concentrations ratios between standard and samples, and the production of spontaneous mutants don't have significant differences. Conclusions All products analyzed by microbiological tests, show that both trademarks and generics do not have statistical variability and the answer of antimicrobial activity Show also that they are pharmaceutical equivalents. PMID:21777438

Evaluation of the use of various rat strains for immunogenic potency tests of Sabin-derived inactivated polio vaccines.

PubMed

Someya, Yuichi; Ami, Yasushi; Takai-Todaka, Reiko; Fujimoto, Akira; Haga, Kei; Murakami, Kosuke; Fujii, Yoshiki; Shirato, Haruko; Oka, Tomoichiro; Shimoike, Takashi; Katayama, Kazuhiko; Wakita, Takaji

2018-03-01

Slc:Wistar rats have been the only strain used in Japan for purpose of evaluating a national reference vaccine for the Sabin-derived inactivated polio vaccine (sIPV) and the immunogenicity of sIPV-containing products. However, following the discovery that the Slc:Wistar strain was genetically related to the Fischer 344 strain, other "real" Wistar strains, such as Crlj:WI, that are available worldwide were tested in terms of their usefulness in evaluating the immunogenicity of the past and current lots of a national reference vaccine. The response of the Crlj:WI rats against the serotype 1 of sIPV was comparable to that of the Slc:Wistar rats, while the Crlj:WI rats exhibited a higher level of response against the serotypes 2 and 3. The immunogenic potency units of a national reference vaccine determined using the Slc:Wistar rats were reproduced on tests using the Crlj:WI rats. These results indicate that a titer of the neutralizing antibody obtained in response to a given dose of sIPV cannot be directly compared between these two rat strains, but that, more importantly, the potency units are almost equivalent for the two rat strains. Copyright © 2018 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Design, synthesis, and molecular docking studies of N-(9,10-anthraquinone-2-carbonyl)amino acid derivatives as xanthine oxidase inhibitors.

PubMed

Zhang, Ting-Jian; Li, Song-Ye; Yuan, Wei-Yan; Zhang, Yi; Meng, Fan-Hao

2018-04-01

A series of N-(9,10-anthraquinone-2-carbonyl)amino acid derivatives (1a-j) was designed and synthesized as novel xanthine oxidase inhibitors. Among them, the L/D-phenylalanine derivatives (1d and 1i) and the L/D-tryptophan derivatives (1e and 1j) were effective with micromolar level potency. In particular, the L-phenylalanine derivative 1d (IC 50  = 3.0 μm) and the D-phenylalanine derivative 1i (IC 50  = 2.9 μm) presented the highest potency and were both more potent than the positive control allopurinol (IC 50  = 8.1 μm). Preliminary SAR analysis pointed that an aromatic amino acid fragment, for example, phenylalanine or tryptophan, was essential for the inhibition; the D-amino acid derivative presented equal or greater potency compared to its L-enantiomer; and the 9,10-anthraquinone moiety was welcome for the inhibition. Molecular simulations provided rational binding models for compounds 1d and 1i in the xanthine oxidase active pocket. As a result, compounds 1d and 1i could be promising lead compounds for further investigation. © 2017 John Wiley & Sons A/S.

How PEGylation enhances the stability and potency of insulin: a molecular dynamics simulation.

PubMed

Yang, Cheng; Lu, Diannan; Liu, Zheng

2011-04-05

While the effectiveness of PEGylation in enhancing the stability and potency of protein pharmaceuticals has been validated for years, the underlying mechanism remains poorly understood, particularly at the molecular level. A molecular dynamics simulation was developed using an annealing procedure that allowed an all-atom level examination of the interaction between PEG polymers of different chain lengths and a conjugated protein represented by insulin. It was shown that PEG became entangled around the protein surface through hydrophobic interaction and concurrently formed hydrogen bonds with the surrounding water molecules. In addition to enhancing its structural stability, as indicated by the root-mean-square difference (rmsd) and secondary structure analyses, conjugation increased the size of the protein drug while decreasing the solvent accessible surface area of the protein. All these thus led to prolonged circulation life despite kidney filtration, proteolysis, and immunogenic side effects, as experimentally demonstrated elsewhere. Moreover, the simulation results indicated that an optimal chain length exists that would maximize drug potency underpinned by the parameters mentioned above. The simulation provided molecular insight into the interaction between PEG and the conjugated protein at the all-atom level and offered a tool that would allow for the design of PEGylated protein pharmaceuticals for given applications.

Structure-activity relationships of rationally designed AMACR 1A inhibitors.

PubMed

Yevglevskis, Maksims; Lee, Guat L; Nathubhai, Amit; Petrova, Yoana D; James, Tony D; Threadgill, Michael D; Woodman, Timothy J; Lloyd, Matthew D

2018-04-30

α-Methylacyl-CoA racemase (AMACR; P504S) is a promising novel drug target for prostate and other cancers. Assaying enzyme activity is difficult due to the reversibility of the 'racemisation' reaction and the difficulties in the separation of epimeric products; consequently few inhibitors have been described and no structure-activity relationship study has been performed. This paper describes the first structure-activity relationship study, in which a series of 23 known and potential rational AMACR inhibitors were evaluated. AMACR was potently inhibited (IC 50  = 400-750 nM) by ibuprofenoyl-CoA and derivatives. Potency was positively correlated with inhibitor lipophilicity. AMACR was also inhibited by straight-chain and branched-chain acyl-CoA esters, with potency positively correlating with inhibitor lipophilicity. 2-Methyldecanoyl-CoAs were ca. 3-fold more potent inhibitors than decanoyl-CoA, demonstrating the importance of the 2-methyl group for effective inhibition. Elimination substrates and compounds with modified acyl-CoA cores were also investigated, and shown to be potent inhibitors. These results are the first to demonstrate structure-activity relationships of rational AMACR inhibitors and that potency can be predicted by acyl-CoA lipophilicity. The study also demonstrates the utility of the colorimetric assay for thorough inhibitor characterisation. Copyright © 2018 Elsevier Inc. All rights reserved.

[Experimental-morphological study of morphogenetic potencies of homogeneous aggregates of different types of cells from the freshwater sponge Ephydatia fluviatilis (L.)].

PubMed

Nikitin, N S

1977-01-01

The morphogenetic potencies of somatic cells of the fresh-water sponge Ephydatia fluviatilis in the developing aggregates depend on their initial specialization and the number of cells in the aggregate. The aggregates of nucleolar amoebocytes consisting of 500 or more cells have the highest morphogenetic potencies. All main cell types can arise in the developing homogeneous aggregates of nucleolar amoebocytes. The fine structure of nucleolar amoebocytes at different stages of development of the homogeneous aggregates was studied by means of electron microscopy. The structural rearrangements are described which accompany the process of redifferentiation of the nucleolar amoebocytes in other cell types.

Embracing transformational leadership: team values and the impact of leader behavior on team performance.

PubMed

Schaubroeck, John; Lam, Simon S K; Cha, Sandra E

2007-07-01

The authors investigated the relationship between transformational leadership behavior and group performance in 218 financial services teams that were branches of a bank in Hong Kong and the United States. Transformational leadership influenced team performance through the mediating effect of team potency. The effect of transformational leadership on team potency was moderated by team power distance and team collectivism, such that higher power distance teams and more collectivistic teams exhibited stronger positive effects of transformational leadership on team potency. The model was supported by data in both Hong Kong and the United States, which suggests a convergence in how teams function in the East and West and highlights the importance of team values.

Synthesis and decreasing Aβ content evaluation of arctigenin-4-yl carbamate derivatives.

PubMed

Xu, Xingyu; Li, Cong; Lei, Min; Zhu, Zhiyuan; Yan, Jianming; Shen, Xu; Hu, Lihong

2016-07-01

A series of arctigenin-4-yl carbamate derivatives were synthesized and evaluated for potency in reducing β-amyloid (Aβ) content in HEK293-APPswe cells. Most of the arctigenin-4-yl aralkyl or aryl carbamate derivatives showed improved potency in reducing Aβ content. Among the synthesized compounds, arctigenin-4-yl (3-chlorophenyl)carbamate (20) exhibited the strongest potency with 78.7% Aβ content reduction at 20μM. Furthermore, the effect of arctigenin-4-yl (4-chlorophenyl)carbamate (19) and arctigenin-4-yl (3-chlorophenyl)carbamate (20) on lowing Aβ content was better than arctigenin under the concentrations of 1, 10 and 20μM. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heterodimerization of μ and δ Opioid Receptors: A Role in Opiate Synergy

PubMed Central

Gomes, I.; Jordan, B. A.; Gupta, A.; Trapaidze, N.; Nagy, V.; Devi, L. A.

2011-01-01

Opiate analgesics are widely used in the treatment of severe pain. Because of their importance in therapy, different strategies have been considered for making opiates more effective while curbing their liability to be abused. Although most opiates exert their analgesic effects primarily via μ opioid receptors, a number of studies have shown that δ receptor-selective drugs can enhance their potency. The molecular basis for these findings has not been elucidated previously. In the present study, we examined whether heterodimerization of μ and δ receptors could account for the cross-modulation previously observed between these two receptors. We find that co-expression of μ and δ receptors in heterologous cells followed by selective immunoprecipitation results in the isolation of μ–δ heterodimers. Treatment of these cells with extremely low doses of certain δ-selective ligands results in a significant increase in the binding of a μ receptor agonist. Similarly, treatment with μ-selective ligands results in a significant increase in the binding of a δ receptor agonist. This robust increase is also seen in SKNSH cells that endogenously express both μ and δ receptors. Furthermore, we find that a δ receptor antagonist enhances both the potency and efficacy of the μ receptor signaling; likewise a μ antagonist enhances the potency and efficacy of the δ receptor signaling. A combination of agonists (μ and δ receptor selective) also synergistically binds and potentiates signaling by activating the μ–δ heterodimer. Taken together, these studies show that heterodimers exhibit distinct ligand binding and signaling characteristics. These findings have important clinical ramifications and may provide new foundations for more effective therapies. PMID:11069979

Use of short-term test systems for the prediction of the hazard represented by potential chemical carcinogens

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

Glass, L.R.; Jones, T.D.; Easterly, C.E.

1990-10-01

It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address themore » problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs.« less

A meta-analysis of asbestos-related cancer risk that addresses fiber size and mineral type.

PubMed

Berman, D Wayne; Crump, Kenny S

2008-01-01

Quantitative estimates of the risk of lung cancer or mesothelioma in humans from asbestos exposure made by the U.S. Environmental Protection Agency (EPA) make use of estimates of potency factors based on phase-contrast microscopy (PCM) and obtained from cohorts exposed to asbestos in different occupational environments. These potency factors exhibit substantial variability. The most likely reasons for this variability appear to be differences among environments in fiber size and mineralogy not accounted for by PCM. In this article, the U.S. Environmental Protection Agency (EPA) models for asbestos-related lung cancer and mesothelioma are expanded to allow the potency of fibers to depend upon their mineralogical types and sizes. This is accomplished by positing exposure metrics composed of nonoverlapping fiber categories and assigning each category its own unique potency. These category-specific potencies are estimated in a meta-analysis that fits the expanded models to potencies for lung cancer (KL's) or mesothelioma (KM's) based on PCM that were calculated for multiple epidemiological studies in our previous paper (Berman and Crump, 2008). Epidemiological study-specific estimates of exposures to fibers in the different fiber size categories of an exposure metric are estimated using distributions for fiber size based on transmission electron microscopy (TEM) obtained from the literature and matched to the individual epidemiological studies. The fraction of total asbestos exposure in a given environment respectively represented by chrysotile and amphibole asbestos is also estimated from information in the literature for that environment. Adequate information was found to allow KL's from 15 epidemiological studies and KM's from 11 studies to be included in the meta-analysis. Since the range of exposure metrics that could be considered was severely restricted by limitations in the published TEM fiber size distributions, it was decided to focus attention on four exposure metrics distinguished by fiber width: "all widths," widths > 0.2 micro m, widths < 0.4 microm, and widths < 0.2 microm, each of which has historical relevance. Each such metric defined by width was composed of four categories of fibers: chrysotile or amphibole asbestos with lengths between 5 microm and 10 microm or longer than 10 microm. Using these metrics three parameters were estimated for lung cancer and, separately, for mesothelioma: KLA, the potency of longer (length > 10 microm) amphibole fibers; rpc, the potency of pure chrysotile (uncontaminated by amphibole) relative to amphibole asbestos; and rps, the potency of shorter fibers (5 microm < length < 10 microm) relative to longer fibers. For mesothelioma, the hypothesis that chrysotile and amphibole asbestos are equally potent (rpc = 1) was strongly rejected by every metric and the hypothesis that (pure) chrysotile is nonpotent for mesothelioma was not rejected by any metric. Best estimates for the relative potency of chrysotile ranged from zero to about 1/200th that of amphibole asbestos (depending on metric). For lung cancer, the hypothesis that chrysotile and amphibole asbestos are equally potent (rpc = 1) was rejected (p < or = .05) by the two metrics based on thin fibers (length < 0.4 microm and < 0.2 microm) but not by the metrics based on thicker fibers. The "all widths" and widths < 0.4 microm metrics provide the best fits to both the lung cancer and mesothelioma data over the other metrics evaluated, although the improvements are only marginal for lung cancer. That these two metrics provide equivalent (for mesothelioma) and nearly equivalent (for lung cancer) fits to the data suggests that the available data sets may not be sufficiently rich (in variation of exposure characteristics) to fully evaluate the effects of fiber width on potency. Compared to the metric with widths > 0.2 microm with both rps and rpc fixed at 1 (which is nominally equivalent to the traditional PCM metric), the "all widths" and widths < 0.4 microm metrics provide substantially better fits for both lung cancer and, especially, mesothelioma. Although the best estimates of the potency of shorter fibers (5 < length < 10 microm) is zero for the "all widths" and widths < 0.4 microm metrics (or a small fraction of that of longer fibers for the widths > 0.2 microm metric for mesothelioma), the hypothesis that these shorter fibers were nonpotent could not be rejected for any of these metrics. Expansion of these metrics to include a category for fibers with lengths < 5 microm did not find any consistent evidence for any potency of these shortest fibers for either lung cancer or mesothelioma. Despite the substantial improvements in fit over that provided by the traditional use of PCM, neither the "all widths" nor the widths < 0.4 microm metrics (or any of the other metrics evaluated) completely resolve the differences in potency factors estimated in different occupational studies. Unresolved in particular is the discrepancy in potency factors for lung cancer from Quebec chrysotile miners and workers at the Charleston, SC, textile mill, which mainly processed chrysotile from Quebec. A leading hypothesis for this discrepancy is limitations in the fiber size distributions available for this analysis. Dement et al. (2007) recently analyzed by TEM archived air samples from the South Carolina plant to determine a detailed distribution of fiber lengths up to lengths of 40 microm and greater. If similar data become available for Quebec, perhaps these two size distributions can be used to eliminate the discrepancy between these two studies.

Exposure reconstruction for the TCDD-exposed NIOSH cohort using a concentration- and age-dependent model of elimination.

PubMed

Aylward, Lesa L; Brunet, Robert C; Starr, Thomas B; Carrier, Gaétan; Delzell, Elizabeth; Cheng, Hong; Beall, Colleen

2005-08-01

Recent studies demonstrating a concentration dependence of elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest that previous estimates of exposure for occupationally exposed cohorts may have underestimated actual exposure, resulting in a potential overestimate of the carcinogenic potency of TCDD in humans based on the mortality data for these cohorts. Using a database on U.S. chemical manufacturing workers potentially exposed to TCDD compiled by the National Institute for Occupational Safety and Health (NIOSH), we evaluated the impact of using a concentration- and age-dependent elimination model (CADM) (Aylward et al., 2005) on estimates of serum lipid area under the curve (AUC) for the NIOSH cohort. These data were used previously by Steenland et al. (2001) in combination with a first-order elimination model with an 8.7-year half-life to estimate cumulative serum lipid concentration (equivalent to AUC) for these workers for use in cancer dose-response assessment. Serum lipid TCDD measurements taken in 1988 for a subset of the cohort were combined with the NIOSH job exposure matrix and work histories to estimate dose rates per unit of exposure score. We evaluated the effect of choices in regression model (regression on untransformed vs. ln-transformed data and inclusion of a nonzero regression intercept) as well as the impact of choices of elimination models and parameters on estimated AUCs for the cohort. Central estimates for dose rate parameters derived from the serum-sampled subcohort were applied with the elimination models to time-specific exposure scores for the entire cohort to generate AUC estimates for all cohort members. Use of the CADM resulted in improved model fits to the serum sampling data compared to the first-order models. Dose rates varied by a factor of 50 among different combinations of elimination model, parameter sets, and regression models. Use of a CADM results in increases of up to five-fold in AUC estimates for the more highly exposed members of the cohort compared to estimates obtained using the first-order model with 8.7-year half-life. This degree of variation in the AUC estimates for this cohort would affect substantially the cancer potency estimates derived from the mortality data from this cohort. Such variability and uncertainty in the reconstructed serum lipid AUC estimates for this cohort, depending on elimination model, parameter set, and regression model, have not been described previously and are critical components in evaluating the dose-response data from the occupationally exposed populations.

Peptide and small molecules rescue the functional activity and agonist potency of dysfunctional human melanocortin-4 receptor polymorphisms.

PubMed

Xiang, Zhimin; Pogozheva, Irina D; Sorenson, Nicholas B; Wilczynski, Andrzej M; Holder, Jerry Ryan; Litherland, Sally A; Millard, William J; Mosberg, Henry I; Haskell-Luevano, Carrie

2007-07-17

The melanocortin pathway, specifically the melanocortin-4 receptor and the cognate endogenous agonist and antagonist ligands, have been strongly implicated in the regulation of energy homeostasis and satiety. Genetic studies of morbidly obese human patients and normal weight control patients have resulted in the discovery of over 70 human melanocortin-4 receptor (MC4R) polymorphisms observed as both heterozygous and homozygous forms. A number of laboratories have been studying these hMC4R polymorphisms attempting to understand the molecular mechanism(s) that might explain the obese human phenotype. Herein, we have studied 13 polymorphic hMC4Rs that have been identified to possess statistically significant decreased endogenous agonist potency with synthetic peptides and small molecules attempting to identify ligands that can pharmacologically rescue the hMC4R polymorphic agonist response. The ligands examined in this study include NDP-MSH, MTII, Ac-His-DPhe-Arg-Trp-NH2 (JRH887-9), Ac-Anc-DPhe-Arg-Trp-NH2 (amino-2-naphtylcarboxylic acid, Anc, JRH420-12), Ac-His-(pI)DPhe-Arg-Trp-NH2 (JRH322-18), chimeric AGRP-melanocortin based ligands (Tyr-c[Cys-His-DPhe-Arg-Trp-Asn-Ala-Phe-Cys]-Tyr-NH2, AMW3-130 and Ac-mini-(His-DPhe-Arg-Trp)-hAGRP-NH2, AMW3-106), and the small molecules JB25 and THIQ. The hMC4R polymorphisms included in this study are S58C, N97D, I102S, L106P, S127L, T150I, R165Q, R165W, L250Q, G252S, C271Y, Y287Stop, and I301T. These studies resulted in the NDP-MSH, MTII, AMW3-130, THIQ, and AMW3-106 ligands possessing nanomolar to subnanomolar agonist potency at the hMC4R polymorphisms examined in this study. Thus, these ligands could generically rescue the potency and stimulatory response of the abnormally functioning hMC4Rs studied and may provide tools to further clarify the molecular mechanism(s) involving these receptor modifications.

Binding Site and Potency Prediction of Teixobactin and other Lipid II Ligands by Statistical Base Scoring of Conformational Space Maps.

PubMed

Lungu, Claudiu N; Diudea, Mircea V

2018-01-01

Lipid II, a peptidoglycan, is a precursor in bacterial cell synthesis. It has both hydrophilic and lipophilic properties. The molecule translocates a bacterial membrane to deliver and incorporate "building blocks" from disaccharide-pentapeptide into the peptidoglican wall. Lipid II is a valid antibiotic target. A receptor binding pocket may be occupied by a ligand in various plausible conformations, among which only few ones are energetically related to a biological activity in the physiological efficiency domain. This paper reports the mapping of the conformational space of Lipid II in its interaction with Teixobactin and other Lipid II ligands. In order to study computationally the complex between Lipid II and ligands, a docking study was first carried on. Docking site was retrieved form literature. After docking, 5 ligand conformations and further 5 complexes (denoted 00 to 04) for each molecule were taken into account. For each structure, conformational studies were performed. Statistical analysis, conformational analysis and molecular dynamics based clustering were used to predict the potency of these compounds. A score for potency prediction was developed. Appling lipid II classification according to Lipid II conformational energy, a conformation of Teixobactin proved to be energetically favorable, followed by Oritravicin, Dalbavycin, Telvanicin, Teicoplamin and Vancomycin, respectively. Scoring of molecules according to cluster band and PCA produced the same result. Molecules classified according to standard deviations showed Dalbavycin as the most favorable conformation, followed by Teicoplamin, Telvanicin, Teixobactin, Oritravicin and Vancomycin, respectively. Total score showing best energetic efficiency of complex formation shows Teixobactin to have the best conformation (a score of 15 points) followed by Dalbavycin (14 points), Oritravicin (12v points), Telvanicin (10 points), Teicoplamin (9 points), Vancomycin (3 points). Statistical analysis of conformations can be used to predict the efficiency of ligand - target interaction and consecutively to find insight regarding ligand potency and postulate about favorable conformation of ligand and binding site. In this study it was shown that Teixobactin is more efficient in binding with Lipid II compared to Vancomycin, results confirmed by experimental data reported in literature. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

RELATIVE POTENCY OF MOLD AND HOUSE DUST MITE EXTRACTS IN INDUCING ALLERGIC RESPONSES IN BALB/C MICE

EPA Science Inventory

Rationale: Mold has been associated with the exacerbation of allergic asthma. However, its role in induction of allergic asthma is not clear. Using a previously developed mouse model for allergic asthma, we compared potencies of two fungal extracts (Metarhizium anisop...