Solubility prediction, solvate and cocrystal screening as tools for rational crystal engineering.

PubMed

Loschen, Christoph; Klamt, Andreas

2015-06-01

The fact that novel drug candidates are becoming increasingly insoluble is a major problem of current drug development. Computational tools may address this issue by screening for suitable solvents or by identifying potential novel cocrystal formers that increase bioavailability. In contrast to other more specialized methods, the fluid phase thermodynamics approach COSMO-RS (conductor-like screening model for real solvents) allows for a comprehensive treatment of drug solubility, solvate and cocrystal formation and many other thermodynamics properties in liquids. This article gives an overview of recent COSMO-RS developments that are of interest for drug development and contains several new application examples for solubility prediction and solvate/cocrystal screening. For all property predictions COSMO-RS has been used. The basic concept of COSMO-RS consists of using the screening charge density as computed from first principles calculations in combination with fast statistical thermodynamics to compute the chemical potential of a compound in solution. The fast and accurate assessment of drug solubility and the identification of suitable solvents, solvate or cocrystal formers is nowadays possible and may be used to complement modern drug development. Efficiency is increased by avoiding costly quantum-chemical computations using a database of previously computed molecular fragments. COSMO-RS theory can be applied to a range of physico-chemical properties, which are of interest in rational crystal engineering. Most notably, in combination with experimental reference data, accurate quantitative solubility predictions in any solvent or solvent mixture are possible. Additionally, COSMO-RS can be extended to the prediction of cocrystal formation, which results in considerable predictive accuracy concerning coformer screening. In a recent variant costly quantum chemical calculations are avoided resulting in a significant speed-up and ease-of-use. © 2015 Royal Pharmaceutical Society.

High throughput screening: an in silico solubility parameter approach for lipids and solvents in SLN preparations.

PubMed

Shah, Malay; Agrawal, Yadvendra

2013-01-01

The present paper describes an in silico solubility behavior of drug and lipids, an essential screening study in preparation of solid lipid nanoparticles (SLN). Ciprofloxacin HCl was selected as a model drug along with 11 lipids and 5 organic solvents. In silico miscibility study of drug/lipid/solvent was performed using Hansen solubility parameter approach calculated by group contribution method of Van Krevelen and Hoftyzer. Predicted solubility was validated by determining solubility of lipids in various solvent at different temperature range, while miscibility of drug in lipids was determined by apparent solubility study and partition experiment. The presence of oxygen and OH functionality increases the polarity and hydrogen bonding possibilities of the compound which has reflected the highest solubility parameter values for Geleol and Capmul MCM C8. Ethyl acetate, Geleol and Capmul MCM C8 was identified as suitable organic solvent, solid lipid and liquid lipid respectively based on a solubility parameter approach which was in agreement with the result of an apparent solubility study and partition coefficient. These works demonstrate the validity of solubility parameter approach and provide a feasible predictor to the rational selection of excipients in designing SLN formulation.

Lattice energy calculation - A quick tool for screening of cocrystals and estimation of relative solubility. Case of flavonoids

NASA Astrophysics Data System (ADS)

Kuleshova, L. N.; Hofmann, D. W. M.; Boese, R.

2013-03-01

Cocrystals (or multicomponent crystals) have physico-chemical properties that are different from crystals of pure components. This is significant in drug development, since the desired properties, e.g. solubility, stability and bioavailability, can be tailored by binding two substances into a single crystal without chemical modification of an active component. Here, the FLEXCRYST program suite, implemented with a data mining force field, was used to estimate the relative stability and, consequently, the relative solubility of cocrystals of flavonoids vs their pure crystals, stored in the Cambridge Structural Database. The considerable potency of this approach for in silico screening of cocrystals, as well as their relative solubility, was demonstrated.

Automated, high-throughput platform for protein solubility screening using a split-GFP system

PubMed Central

Listwan, Pawel; Terwilliger, Thomas C.

2010-01-01

Overproduction of soluble and stable proteins for functional and structural studies is a major bottleneck for structural genomics programs and traditional biochemistry laboratories. Many high-payoff proteins that are important in various biological processes are “difficult to handle” as protein reagents in their native form. We have recently made several advances in enabling biochemical technologies for improving protein stability (http://www.lanl.gov/projects/gfp/), allowing stratagems for efficient protein domain trapping, solubility-improving mutations, and finding protein folding partners. In particular split-GFP protein tags are a very powerful tool for detection of stable protein domains. Soluble, stable proteins tagged with the 15 amino acid GFP fragment (amino acids 216–228) can be detected in vivo and in vitro using the engineered GFP 1–10 “detector” fragment (amino acids 1–215). If the small tag is accessible, the detector fragment spontaneously binds resulting in fluorescence. Here, we describe our current and on-going efforts to move this process from the bench (manual sample manipulation) to an automated, high-throughput, liquid-handling platform. We discuss optimization and validation of bacterial culture growth, lysis protocols, protein extraction, and assays of soluble and insoluble protein in multiple 96 well plate format. The optimized liquid-handling protocol can be used for rapid determination of the optimal, compact domains from single ORFS, collections of ORFS, or cDNA libraries. PMID:19039681

High-throughput method for optimum solubility screening for homogeneity and crystallization of proteins

DOEpatents

Kim, Sung-Hou [Moraga, CA; Kim, Rosalind [Moraga, CA; Jancarik, Jamila [Walnut Creek, CA

2012-01-31

An optimum solubility screen in which a panel of buffers and many additives are provided in order to obtain the most homogeneous and monodisperse protein condition for protein crystallization. The present methods are useful for proteins that aggregate and cannot be concentrated prior to setting up crystallization screens. A high-throughput method using the hanging-drop method and vapor diffusion equilibrium and a panel of twenty-four buffers is further provided. Using the present methods, 14 poorly behaving proteins have been screened, resulting in 11 of the proteins having highly improved dynamic light scattering results allowing concentration of the proteins, and 9 were crystallized.

Managing evaporation for more robust microscale assays. Part 2. Characterization of convection and diffusion for cell biology.

PubMed

Berthier, Erwin; Warrick, Jay; Yu, Hongmeiy; Beebe, David J

2008-06-01

Cell based microassays allow the screening of a multitude of culture conditions in parallel, which can be used for various applications from drug screening to fundamental cell biology research. Tubeless microfluidic devices based on passive pumping are a step towards accessible high throughput microassays, however they are vulnerable to evaporation. In addition to volume loss, evaporation can lead to the generation of small flows. Here, we focus on issues of convection and diffusion for cell culture in microchannels and particularly the transport of soluble factors secreted by cells. We find that even for humidity levels as high as 95%, convection in a passive pumping channel can significantly alter distributions of these factors and that appropriate system design can prevent convection.

Non-nucleoside inhibitors of the measles virus RNA-dependent RNA polymerase: synthesis, structure-activity relationships, and pharmacokinetics.

PubMed

Ndungu, J Maina; Krumm, Stefanie A; Yan, Dan; Arrendale, Richard F; Reddy, G Prabhakar; Evers, Taylor; Howard, Randy; Natchus, Michael G; Saindane, Manohar T; Liotta, Dennis C; Plemper, Richard K; Snyder, James P; Sun, Aiming

2012-05-10

The measles virus (MeV), a member of the paramyxovirus family, is an important cause of pediatric morbidity and mortality worldwide. In an effort to provide therapeutic treatments for improved measles management, we previously identified a small, non-nucleoside organic inhibitor of the viral RNA-dependent RNA polymerase by means of high-throughput screening. Subsequent structure-activity relationship (SAR) studies around the corresponding pyrazole carboxamide scaffold led to the discovery of 2 (AS-136a), a first generation lead with low nanomolar potency against life MeV and attractive physical properties suitable for development. However, its poor water solubility and low oral bioavailability (F) in rat suggested that the lead could benefit from further SAR studies to improve the biophysical characteristics of the compound. Optimization of in vitro potency and aqueous solubility led to the discovery of 2o (ERDRP-00519), a potent inhibitor of MeV (EC(50) = 60 nM) with an aqueous solubility of approximately 60 μg/mL. The agent shows a 10-fold exposure (AUC/C(max)) increase in the rat model relative to 2, displays near dose proportionality in the range of 10-50 mg/kg, and exhibits good oral bioavailability (F = 39%). The significant solubility increase appears linked to the improved oral bioavailability.

Fragment-Based Phenotypic Lead Discovery: Cell-Based Assay to Target Leishmaniasis.

PubMed

Ayotte, Yann; Bilodeau, François; Descoteaux, Albert; LaPlante, Steven R

2018-05-02

A rapid and practical approach for the discovery of new chemical matter for targeting pathogens and diseases is described. Fragment-based phenotypic lead discovery (FPLD) combines aspects of traditional fragment-based lead discovery (FBLD), which involves the screening of small-molecule fragment libraries to target specific proteins, with phenotypic lead discovery (PLD), which typically involves the screening of drug-like compounds in cell-based assays. To enable FPLD, a diverse library of fragments was first designed, assembled, and curated. This library of soluble, low-molecular-weight compounds was then pooled to expedite screening. Axenic cultures of Leishmania promastigotes were screened, and single hits were then tested for leishmanicidal activity against intracellular amastigote forms in infected murine bone-marrow-derived macrophages without evidence of toxicity toward mammalian cells. These studies demonstrate that FPLD can be a rapid and effective means to discover hits that can serve as leads for further medicinal chemistry purposes or as tool compounds for identifying known or novel targets. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative Study of Different Methods for the Prediction of Drug-Polymer Solubility.

PubMed

Knopp, Matthias Manne; Tajber, Lidia; Tian, Yiwei; Olesen, Niels Erik; Jones, David S; Kozyra, Agnieszka; Löbmann, Korbinian; Paluch, Krzysztof; Brennan, Claire Marie; Holm, René; Healy, Anne Marie; Andrews, Gavin P; Rades, Thomas

2015-09-08

In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid analogues of the PVP/VA copolymer (N-vinylpyrrolidone and vinyl acetate). The predicted solubilities at 25 °C varied considerably depending on the method used. However, the three thermal analysis methods ranked the predicted solubilities in the same order, except for the felodipine-PVP system. Furthermore, the magnitude of the predicted solubilities from the recrystallization method and melting point depression method correlated well with the estimates based on the solubility in the liquid analogues, which suggests that this method can be used as an initial screening tool if a liquid analogue is available. The learnings of this important comparative study provided general guidance for the selection of the most suitable method(s) for the screening of drug-polymer solubility.

Poloxamer-Based Thermoreversible Gel for Topical Delivery of Emodin: Influence of P407 and P188 on Solubility of Emodin and Its Application in Cellular Activity Screening.

PubMed

Ban, Eunmi; Park, Mijung; Jeong, Seonghee; Kwon, Taekhyun; Kim, Eun-Hee; Jung, Kiwon; Kim, Aeri

2017-02-07

Emodin is a component in a Chinese herb, Rheum officinale Baill, traditionally used for diabetes and anticancer. Its poor solubility is one of the major challenges to pharmaceutical scientists. We previously reported on thermoreversible gel formulations based on poloxamer for the topical delivery of emodin. The present study was to understand the effect of poloxamer type on emodin solubility and its application in cellular activity screening. Various gel formulations composed of poloxamer 407 (P407), poloxamer 188 (P188) and PEG400 were prepared and evaluated. Major evaluation parameters were the gelation temperature (Tgel) and solubility of emodin. The emodin solubility increased with increasing poloxamer concentration and the Tgel was modulated by the proper combination of P407. In particular, this study showed that the amount of P407 in thermoreversible poloxamer gel (PG) was the dominant factor in enhancing solubility and P188 was effective at fixing gelation temperature in the desired range. A thermoreversible emodin PG was selected as the proper composition with the liquid state at room temperature and gel state at body temperature. The gel showed the solubility enhancement of emodin at least 100-fold compared to 10% ethanol or water. The thermoreversible formulation was applied for in vitro cellular activity screening in the human dermal fibroblast cell line and DLD-1 colon cancer cell line after dilution with cell culture media. The thermoreversible gel formulation remained as a clear solution in the microplate, which allowed reliable cellular activity screening. In contrast, emodin solution in ethanol or DMSO showed precipitation at the corresponding emodin concentration, complicating data interpretation. In conclusion, the gel formulation is proposed as a useful prototype topical formulation for testing emodin in vivo as well as in vitro.

Streamlined system for purifying and quantifying a diverse library of compounds and the effect of compound concentration measurements on the accurate interpretation of biological assay results.

PubMed

Popa-Burke, Ioana G; Issakova, Olga; Arroway, James D; Bernasconi, Paul; Chen, Min; Coudurier, Louis; Galasinski, Scott; Jadhav, Ajit P; Janzen, William P; Lagasca, Dennis; Liu, Darren; Lewis, Roderic S; Mohney, Robert P; Sepetov, Nikolai; Sparkman, Darren A; Hodge, C Nicholas

2004-12-15

As part of an overall systems approach to generating highly accurate screening data across large numbers of compounds and biological targets, we have developed and implemented streamlined methods for purifying and quantitating compounds at various stages of the screening process, coupled with automated "traditional" storage methods (DMSO, -20 degrees C). Specifically, all of the compounds in our druglike library are purified by LC/MS/UV and are then controlled for identity and concentration in their respective DMSO stock solutions by chemiluminescent nitrogen detection (CLND)/evaporative light scattering detection (ELSD) and MS/UV. In addition, the compound-buffer solutions used in the various biological assays are quantitated by LC/UV/CLND to determine the concentration of compound actually present during screening. Our results show that LC/UV/CLND/ELSD/MS is a widely applicable method that can be used to purify, quantitate, and identify most small organic molecules from compound libraries. The LC/UV/CLND technique is a simple and sensitive method that can be easily and cost-effectively employed to rapidly determine the concentrations of even small amounts of any N-containing compound in aqueous solution. We present data to establish error limits for concentration determination that are well within the overall variability of the screening process. This study demonstrates that there is a significant difference between the predicted amount of soluble compound from stock DMSO solutions following dilution into assay buffer and the actual amount present in assay buffer solutions, even at the low concentrations employed for the assays. We also demonstrate that knowledge of the concentrations of compounds to which the biological target is exposed is critical for accurate potency determinations. Accurate potency values are in turn particularly important for drug discovery, for understanding structure-activity relationships, and for building useful empirical models of protein-ligand interactions. Our new understanding of relative solubility demonstrates that most, if not all, decisions that are made in early discovery are based upon missing or inaccurate information. Finally, we demonstrate that careful control of compound handling and concentration, coupled with accurate assay methods, allows the use of both positive and negative data in analyzing screening data sets for structure-activity relationships that determine potency and selectivity.

Accelerated oral nanomedicine discovery from miniaturized screening to clinical production exemplified by paediatric HIV nanotherapies

PubMed Central

Giardiello, Marco; Liptrott, Neill J.; McDonald, Tom O.; Moss, Darren; Siccardi, Marco; Martin, Phil; Smith, Darren; Gurjar, Rohan; Rannard, Steve P.; Owen, Andrew

2016-01-01

Considerable scope exists to vary the physical and chemical properties of nanoparticles, with subsequent impact on biological interactions; however, no accelerated process to access large nanoparticle material space is currently available, hampering the development of new nanomedicines. In particular, no clinically available nanotherapies exist for HIV populations and conventional paediatric HIV medicines are poorly available; one current paediatric formulation utilizes high ethanol concentrations to solubilize lopinavir, a poorly soluble antiretroviral. Here we apply accelerated nanomedicine discovery to generate a potential aqueous paediatric HIV nanotherapy, with clinical translation and regulatory approval for human evaluation. Our rapid small-scale screening approach yields large libraries of solid drug nanoparticles (160 individual components) targeting oral dose. Screening uses 1 mg of drug compound per library member and iterative pharmacological and chemical evaluation establishes potential candidates for progression through to clinical manufacture. The wide applicability of our strategy has implications for multiple therapy development programmes. PMID:27767027

Solubility of lead and copper in biochar-amended small arms range soils: influence of soil organic carbon and pH.

PubMed

Uchimiya, Minori; Bannon, Desmond I

2013-08-14

Biochar is often considered a strong heavy metal stabilizing agent. However, biochar in some cases had no effects on, or increased the soluble concentrations of, heavy metals in soil. The objective of this study was to determine the factors causing some biochars to stabilize and others to dissolve heavy metals in soil. Seven small arms range soils with known total organic carbon (TOC), cation exchange capacity, pH, and total Pb and Cu contents were first screened for soluble Pb and Cu concentrations. Over 2 weeks successive equilibrations using weak acid (pH 4.5 sulfuric acid) and acetate buffer (0.1 M at pH 4.9), Alaska soil containing disproportionately high (31.6%) TOC had nearly 100% residual (insoluble) Pb and Cu. This soil was then compared with sandy soils from Maryland containing significantly lower (0.5-2.0%) TOC in the presence of 10 wt % (i) plant biochar activated to increase the surface-bound carboxyl and phosphate ligands (PS450A), (ii) manure biochar enriched with soluble P (BL700), and (iii) unactivated plant biochars produced at 350 °C (CH350) and 700 °C (CH500) and by flash carbonization (corn). In weak acid, the pH was set by soil and biochar, and the biochars increasingly stabilized Pb with repeated extractions. In pH 4.9 acetate buffer, PS450A and BL700 stabilized Pb, and only PS450A stabilized Cu. Surface ligands of PS450A likely complexed and stabilized Pb and Cu even under acidic pH in the presence of competing acetate ligand. Oppositely, unactivated plant biochars (CH350, CH500, and corn) mobilized Pb and Cu in sandy soils; the putative mechanism is the formation of soluble complexes with biochar-borne dissolved organic carbon. In summary, unactivated plant biochars can inadvertently increase dissolved Pb and Cu concentrations of sandy, low TOC soils when used to stabilize other contaminants.

Solid-Phase Biological Assays for Drug Discovery

NASA Astrophysics Data System (ADS)

Forsberg, Erica M.; Sicard, Clémence; Brennan, John D.

2014-06-01

In the past 30 years, there has been a significant growth in the use of solid-phase assays in the area of drug discovery, with a range of new assays being used for both soluble and membrane-bound targets. In this review, we provide some basic background to typical drug targets and immobilization protocols used in solid-phase biological assays (SPBAs) for drug discovery, with emphasis on particularly labile biomolecular targets such as kinases and membrane-bound receptors, and highlight some of the more recent approaches for producing protein microarrays, bioaffinity columns, and other devices that are central to small molecule screening by SPBA. We then discuss key applications of such assays to identify drug leads, with an emphasis on the screening of mixtures. We conclude by highlighting specific advantages and potential disadvantages of SPBAs, particularly as they relate to particular assay formats.

A Micro-Polyethylene Glycol Precipitation Assay as a Relative Solubility Screening Tool for Monoclonal Antibody Design and Formulation Development.

PubMed

Toprani, Vishal M; Joshi, Sangeeta B; Kueltzo, Lisa A; Schwartz, Richard M; Middaugh, C Russell; Volkin, David B

2016-08-01

Adequate protein solubility is an important prerequisite for development, manufacture, and administration of biotherapeutic drug candidates, especially for high-concentration protein formulations. A previously established method for determining the relative apparent solubility (thermodynamic activity) of proteins using polyethylene glycol (PEG) precipitation is adapted for screening and comparing monoclonal antibody (mAb) candidates where only limited quantities (≤1 mg) are available. This micro-PEG assay is used to evaluate various broadly neutralizing mAb candidates to HIV-1 viral spike (gp120 and gp41 glycoproteins). Using ∼1 mg of VRC01-WT mAb per assay, the precision of the micro-PEG assay was established. A series of 7 different broadly neutralizing mAbs to the HIV-1 viral spike proteins were compared by curve shape (%PEG vs. protein concentration), %PEGmidpoint determinations, and extrapolated apparent solubility values. Numerous formulation conditions were then evaluated for their relative effects on the VRC01-WT mAb. The PEGmidpt and apparent solubility values of VRC01-WT mAb decreased as the solution pH increased and increased as NaCl and arginine were added. A final optimization of the micro-PEG assay established that amounts as low as 0.1-0.2 mg can be used. Thus, the micro-PEG assay has significant potential as a relative solubility screening tool during candidate selection and early formulation development. Copyright © 2016 American Pharmacists Association®. All rights reserved.

The Center for Optimized Structural Studies (COSS) platform for automation in cloning, expression, and purification of single proteins and protein-protein complexes.

PubMed

Mlynek, Georg; Lehner, Anita; Neuhold, Jana; Leeb, Sarah; Kostan, Julius; Charnagalov, Alexej; Stolt-Bergner, Peggy; Djinović-Carugo, Kristina; Pinotsis, Nikos

2014-06-01

Expression in Escherichia coli represents the simplest and most cost effective means for the production of recombinant proteins. This is a routine task in structural biology and biochemistry where milligrams of the target protein are required in high purity and monodispersity. To achieve these criteria, the user often needs to screen several constructs in different expression and purification conditions in parallel. We describe a pipeline, implemented in the Center for Optimized Structural Studies, that enables the systematic screening of expression and purification conditions for recombinant proteins and relies on a series of logical decisions. We first use bioinformatics tools to design a series of protein fragments, which we clone in parallel, and subsequently screen in small scale for optimal expression and purification conditions. Based on a scoring system that assesses soluble expression, we then select the top ranking targets for large-scale purification. In the establishment of our pipeline, emphasis was put on streamlining the processes such that it can be easily but not necessarily automatized. In a typical run of about 2 weeks, we are able to prepare and perform small-scale expression screens for 20-100 different constructs followed by large-scale purification of at least 4-6 proteins. The major advantage of our approach is its flexibility, which allows for easy adoption, either partially or entirely, by any average hypothesis driven laboratory in a manual or robot-assisted manner.

Methods and options in vitro dialyzability; benefits and limitations.

PubMed

Sandberg, Ann-Sofie

2005-11-01

In vitro dialyzability methods involve a two-step digestion process simulating the gastric and intestinal phase, and dialysis through a semi-permeable membrane with a selected molecular weight cut-off. Dialyzable iron/zinc is used as an estimation of available mineral. Final pH adjustment and use of a strict time schedule were found to be critical factors for standardization. In addition the selected cut-off of the dialysis membrane and the method used for iron and zinc determination influence the results. For screening purposes, simple solubility or dialyzability methods seem preferable to the more sophisticated computer-controlled gastrointestinal model. This is likely more valuable in studies of different transit times and sites of dialyzability. In vitro solubility/dialyzability methods correlate in most cases with human absorption studies in ranking iron and zinc availability from different meals. Exceptions may be that effects of milk, certain proteins, tea, and organic acids cannot be predicted. The dialyzability methods exclude iron bound to large molecules, which in some cases is available and include iron bound to small molecules, which is not always available. In vitro experiments based on solubility/dialyzability are tools to understand factors that may affect subsequent mineral absorption.

Oral water soluble contrast for the management of adhesive small bowel obstruction.

PubMed

Abbas, S; Bissett, I P; Parry, B R

2005-01-25

Adhesions are the leading cause of small bowel obstruction. Most adhesive small bowel obstructions resolve following conservative treatment but there is no consensus as to when conservative treatment should be considered unsuccessful and the patient should undergo surgery. Studies have shown that failure of an oral water-soluble contrast to reach the colon after a designated time indicates complete intestinal obstruction that is unlikely to resolve with conservative treatment. Other studies have suggested that the administration of water-soluble contrast is therapeutic in resolving the obstruction. The aims of this review are:1. To determine the reliability of water-soluble contrast media and serial abdominal radiographs in predicting the success of conservative treatment in patients admitted with adhesive small bowel obstruction.2. To determine the efficacy and safety of water-soluble contrast media in reducing the need for surgical intervention and reducing hospital stay in adhesive small bowel obstruction. The search was conducted using MeSH terms: ''Intestinal obstruction'', ''water-soluble contrast'', "Adhesions" and "Gastrografin", and combined with the Cochrane Collaboration highly sensitive search strategy for identifying randomised controlled trials and controlled clinical trials. 1. Prospective studies (to evaluate the diagnostic potential of water-soluble contrast in adhesive small bowel obstruction);2. Randomised clinical trials (to evaluate the therapeutic role). 1. Studies addressing the diagnostic role of water-soluble contrast were critically appraised and data presented as sensitivities, specificities and positive and negative likelihood ratios. Results were pooled and summary receiver operating characteristic (ROC) curve was constructed. 2. A meta-analysis of the data from therapeutic studies was performed using the Mantel -Haenszel test using both the fixed effect and random effects model. The appearance of water-soluble contrast in the caecum on an abdominal radiograph within 24 hours of its administration predicts resolution of an adhesive small bowel obstruction with a pooled sensitivity of 0.96, specificity of 0.96. The area under the curve of the summary ROC was 0.98. Four randomised studies dealing with the therapeutic role of Gastrografin were included in the review, water-soluble contrast did not reduce the need for surgical intervention (odds ratio 1.29, P = 0.36). Meta-analysis of two studies showed that water-soluble contrast reduced hospital stay compared with placebo (weighted mean difference = - 2.58) P = 0.004. Published literature strongly supports the use of water-soluble contrast as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not cause resolution of small bowel obstruction, it does appear to reduce hospital stay.

Immobilized OBOC combinatorial bead array to facilitate multiplicative screening.

PubMed

Xiao, Wenwu; Bononi, Fernanda C; Townsend, Jared; Li, Yuanpei; Liu, Ruiwu; Lam, Kit S

2013-07-01

One-bead-one-compound (OBOC) combinatorial library screening has been broadly utilized for the last two decades to identify small molecules, peptides or peptidomimetics targeting variable screening probes such as cell surface receptors, bacteria, protein kinases, phosphatases, proteases etc. In previous screening methods, library beads were suspended in solution and screened against one single probe. Only the positive beads were tracked and isolated for additional screens and finally selected for chemical decoding. During this process, the remaining negative beads were not tracked and discarded. Here we report a novel bead immobilization method such that a bead library array can be conveniently prepared and screened in its entirety, sequentially many times with a series of distinct probes. This method not only allows us to increase the screening efficiency but also permits us to determine the binding profile of each and every library bead against a large number of target receptors. As proof of concept, we serially screened a random OBOC disulfide containing cyclic heptapeptide library with three water soluble dyes as model probes: malachite green, bromocresol purple and indigo carmine. This multiplicative screening approach resulted in a rapid determination of the binding profile of each and every bead respective to each of the three dyes. Beads that interacted with malachite green only, bromocresol purple only, or both indigo carmine and bromocresol purple were isolated, and their peptide sequences were determined with microsequencer. Ultimately, the novel OBOC multiplicative screening approach could play a key role in the enhancement of existing on-bead assays such as whole cell binding, bacteria binding, protein binding, posttranslational modifications etc. with increased efficiency, capacity, and specificity.

Cocrystal formation, crystal structure, solubility and permeability studies for novel 1,2,4-thiadiazole derivative as a potent neuroprotector.

PubMed

Surov, Artem O; Volkova, Tatyana V; Churakov, Andrei V; Proshin, Alexey N; Terekhova, Irina V; Perlovich, German L

2017-11-15

The cocrystallization approach has been applied to modify the poor solubility profile of the biologically active 1,2,4-thiadiazole derivative (TDZ). Extensive cocrystal screening with a library of coformers resulted in formation of a new solid form of TDZ with vanillic acid in a 1:1 molar ratio. The cocrystalline phase was identified and characterized by thermal and diffraction analyses including single-crystal X-ray diffraction. The energies of intermolecular interactions in the crystal were calculated by solid-state DFT and PIXEL methods. Both calculation schemes show good consistency in terms of total energy of the intermolecular interactions and suggest that the cocrystal is mainly stabilized via hydrogen bonds, which provide ca. 44% of the lattice energy. Since the cocrystal contained the hydroxybenzoic acid derivative as a coformer, the solubility profile of the cocrystal was investigated at different pHs using eutectic concentrations of the components. Furthermore, the influence of the cocrystallization on the permeability performance of the 1,2,4-thiadiazole through an artificial regenerated cellulose membrane was also evaluated. In addition, the thermodynamic functions of the cocrystal formation were estimated from the solubility of the cocrystal and the corresponding solubility of the pure compounds at various temperatures. The cocrystal formation process was found to have a relatively small value of the driving force (-5.3kJ·mol -1 ). The most significant contribution to the Gibbs energy was provided by the exothermic enthalpy of formation. Copyright © 2017 Elsevier B.V. All rights reserved.

Rational development of solid dispersions via hot-melt extrusion using screening, material characterization, and numeric simulation tools.

PubMed

Zecevic, Damir E; Wagner, Karl G

2013-07-01

Effective and predictive small-scale selection tools are inevitable during the development of a solubility enhanced drug product. For hot-melt extrusion, this selection process can start with a microscale performance evaluation on a hot-stage microscope (HSM). A batch size of 400 mg can provide sufficient materials to assess the drug product attributes such as solid-state properties, solubility enhancement, and physical stability as well as process related attributes such as processing temperature in a twin-screw extruder (TSE). Prototype formulations will then be fed into a 5 mm TSE (~1-2 g) to confirm performance from the HSM under additional shear stress. Small stress stability testing might be performed with these samples or a larger batch (20-40 g) made by 9 or 12 mm TSE. Simultaneously, numeric process simulations are performed using process data as well as rheological and thermal properties of the formulations. Further scale up work to 16 and 18 mm TSE confirmed and refined the simulation model. Thus, at the end of the laboratory-scale development, not only the clinical trial supply could be manufactured, but also one can form a sound risk assessment to support further scale up even without decades of process experience. Copyright © 2013 Wiley Periodicals, Inc.

Salting Constants of Small Organic Molecules in Aerosol-Relevant Salts and Application to Aerosol Formation in the Southeastern United States

NASA Astrophysics Data System (ADS)

Waxman, E.; Carlton, A. M. G.; Ziemann, P. J.; Volkamer, R. M.

2014-12-01

Secondary organic aerosol (SOA) formation from small water-soluble molecules such as glyoxal and methyl glyoxal is a topic of emerging interest. Results from recent field campaigns, e.g. Waxman et al. (2013, GRL) and Knote et al. (2014, ACP), show that these molecules can form significant SOA mass as a result of 'salting-in'. Salting-in happens when a molecule's solubility increases with salt concentration and salting-out is the reverse. Salting effects modify the solubility exponentially with increasing salt concentration, and thus the effective Henry's law constant can strongly modify partitioning, and multiphase chemical reaction rates in aerosol water. Moreover, the solubility in aerosol water cannot easily inferred based on the solubility in cloud water, as the salting effects could change the solubility by a factor of 104 or more. In this work, we have devised and applied a novel experimental setup to measure salting constants using an ion trap mass spectrometer. We focus on small, water soluble molecules like methyl glyoxal and similar compounds and measure salting constants for aerosol-relevant salts including ammonium sulfate, ammonium nitrate, and sodium chloride. The Setschenow salting-constant values are then used to parameterize the effects of salting in CMAQ. We present a series of sensitivity studies of the effects that inorganic aerosols have on the SOA formation from small soluble molecules in the southeastern United States.

High-throughput 96-well solvent mediated sonic blending synthesis and on-plate solid/solution stability characterization of pharmaceutical cocrystals.

PubMed

Luu, Van; Jona, Janan; Stanton, Mary K; Peterson, Matthew L; Morrison, Henry G; Nagapudi, Karthik; Tan, Helming

2013-01-30

A 96-well high-throughput cocrystal screening workflow has been developed consisting of solvent-mediated sonic blending synthesis and on-plate solid/solution stability characterization by XRPD. A strategy of cocrystallization screening in selected blend solvents including water mixtures is proposed to not only manipulate solubility of the cocrystal components but also differentiate physical stability of the cocrystal products. Caffeine-oxalic acid and theophylline-oxalic acid cocrystals were prepared and evaluated in relation to saturation levels of the cocrystal components and stability of the cocrystal products in anhydrous and hydrous solvents. AMG 517 was screened with a number of coformers, and solid/solution stability of the resulting cocrystals on the 96-well plate was investigated. A stability trend was observed and confirmed that cocrystals comprised of lower aqueous solubility coformers tended to be more stable in water. Furthermore, cocrystals which could be isolated under hydrous solvent blending condition exhibited superior physical stability to those which could only be obtained under anhydrous condition. This integrated HTS workflow provides an efficient route in an API-sparing approach to screen and identify cocrystal candidates with proper solubility and solid/solution stability properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Detailed study of precipitation of a poorly water soluble test compound using methodologies as in activity and solubility screening - mixing and automation effects.

PubMed

Gillespie, Cheska; Kennedy, Alan R; Edwards, Darren; Dowden, Lee; Daublain, Pierre; Halling, Peter

2013-09-01

Storage of pharmaceutical discovery compounds dissolved in dimethylsulfoxide (DMSO) is commonplace within industry. Often, the DMSO stock solution is added to an aqueous system (e.g. in bioassay or kinetic solubility testing)- since most test compounds are hydrophobic, precipitation could occur. Little is known about the factors affecting this precipitation process at the low (µM) concentrations used in screening analyses. Here, a poorly water soluble test compound (tolnaftate) was used to compare manual and automated pipetting, and explore the effect of mixing variables on precipitation. The amount of drug present in the supernatant after precipitation and centrifugation of the samples was quantified. An unusual result was obtained in three different laboratories: results of experiments performed initially were statistically significantly higher than those performed after a few days in the same lab. No significant differences were found between automated and manual pipetting, including in variability. Vortex mixing was found to give significantly lower supernatant amounts compared to milder mixing types. The mixing employed affects the particle growth of the precipitate. These findings are of relevance to discovery stage bioassay and kinetic solubility analyses.

Comparison of a rational vs. high throughput approach for rapid salt screening and selection.

PubMed

Collman, Benjamin M; Miller, Jonathan M; Seadeek, Christopher; Stambek, Julie A; Blackburn, Anthony C

2013-01-01

In recent years, high throughput (HT) screening has become the most widely used approach for early phase salt screening and selection in a drug discovery/development setting. The purpose of this study was to compare a rational approach for salt screening and selection to those results previously generated using a HT approach. The rational approach involved a much smaller number of initial trials (one salt synthesis attempt per counterion) that were selected based on a few strategic solubility determinations of the free form combined with a theoretical analysis of the ideal solvent solubility conditions for salt formation. Salt screening results for sertraline, tamoxifen, and trazodone using the rational approach were compared to those previously generated by HT screening. The rational approach produced similar results to HT screening, including identification of the commercially chosen salt forms, but with a fraction of the crystallization attempts. Moreover, the rational approach provided enough solid from the very initial crystallization of a salt for more thorough and reliable solid-state characterization and thus rapid decision-making. The crystallization techniques used in the rational approach mimic larger-scale process crystallization, allowing smoother technical transfer of the selected salt to the process chemist.

Dual Level Statistical Investigation of Equilibrium Solubility in Simulated Fasted and Fed Intestinal Fluid

PubMed Central

2017-01-01

The oral route is the preferred option for drug administration but contains the inherent issue of drug absorption from the gastro-intestinal tract (GIT) in order to elicit systemic activity. A prerequisite for absorption is drug dissolution, which is dependent upon drug solubility in the variable milieu of GIT fluid, with poorly soluble drugs presenting a formulation and biopharmaceutical challenge. Multiple factors within GIT fluid influence solubility ranging from pH to the concentration and ratio of amphiphilic substances, such as phospholipid, bile salt, monoglyceride, and cholesterol. To aid in vitro investigation simulated intestinal fluids (SIF) covering the fasted and fed state have been developed. SIF media is complex and statistical design of experiment (DoE) investigations have revealed the range of solubility values possible within each state due to physiological variability along with the media factors and factor interactions which influence solubility. However, these studies require large numbers of experiments (>60) and are not feasible or sensible within a drug development setting. In the current study a smaller dual level, reduced experimental number (20) DoE providing three arms covering the fasted and fed states along with a combined analysis has been investigated. The results indicate that this small scale investigation is feasible and provides solubility ranges that encompass published data in human and simulated fasted and fed fluids. The measured fasted and fed solubility ranges are in agreement with published large scale DoE results in around half of the cases, with the differences due to changes in media composition between studies. Indicating that drug specific behaviors are being determined and that careful media factor and concentration level selection is required in order to determine a physiologically relevant solubility range. The study also correctly identifies the major single factor or factors which influence solubility but it is evident that lower significance factors (for example bile salt) are not picked up due to the lower sample number employed. A similar issue is present with factor interactions with only a limited number available for study and generally not determined to have a significant solubility impact due to the lower statistical power of the study. The study indicates that a reduced experimental number DoE is feasible, will provide solubility range results with identification of major solubility factors however statistical limitations restrict the analysis. The approach therefore represents a useful initial screening tool that can guide further in depth analysis of a drug’s behavior in gastrointestinal fluids. PMID:29072917

Evaluation of 14 Organic Solvents and Carriers for Screening Applications in Zebrafish Embryos and Larvae

PubMed Central

Maes, Jan; Verlooy, Lien; Buenafe, Olivia E.; de Witte, Peter A. M.; Esguerra, Camila V.; Crawford, Alexander D.

2012-01-01

Zebrafish are rapidly growing in popularity as an in vivo model system for chemical genetics, drug discovery, and toxicology, and more recently also for natural product discovery. Experiments involving the pharmacological evaluation of small molecules or natural product extracts in zebrafish bioassays require the effective delivery of these compounds to embryos and larvae. While most samples to be screened are first solubilized in dimethyl sulfoxide (DMSO), which is then diluted in the embryo medium, often this method is not sufficient to prevent the immediate or eventual precipitation of the sample. Certain compounds and extracts are also not highly soluble in DMSO. In such instances the use of carriers and/or other solvents might offer an alternative means to achieve the required sample concentration. Towards this end, we determined the maximum tolerated concentration (MTC) of several commonly used solvents and carriers in zebrafish embryos and larvae at various developmental stages. Solvents evaluated for this study included acetone, acetonitrile, butanone, dimethyl formamide, DMSO, ethanol, glycerol, isopropanol, methanol, polyethylene glycol (PEG-400), propylene glycol, and solketal, and carriers included albumin (BSA) and cyclodextrin (2-hydroxypropyl-beta-cyclodextrin, or HPBCD). This study resulted in the identification of polyethylene glycol (PEG400), propylene glycol, and methanol as solvents that were relatively well-tolerated over a range of developmental stages. In addition, our results showed that acetone was well-tolerated by embryos but not by larvae, and 1% cyclodextrin (HPBCD) was well-tolerated by both embryos and larvae, indicating the utility of this carrier for compound screening in zebrafish. However, given the relatively small differences (2–3 fold) between concentrations that are apparently safe and those that are clearly toxic, further studies – e.g. omics analyses –should be carried out to determine which cellular processes and signalling pathways are affected by any solvents and carriers that are used for small-molecule screens in zebrafish. PMID:23082109

Oral water soluble contrast for the management of adhesive small bowel obstruction.

PubMed

Abbas, S; Bissett, I P; Parry, B R

2007-07-18

Adhesions are the leading cause of small bowel obstruction. Gastrografin transit time may allow for the selection of appropriate patients for non-operative management. Some studies have shown when the contrast does not reach the colon after a designated time it indicates complete intestinal obstruction that is unlikely to resolve with conservative treatment. When the contrast does reach the large bowel, it indicates partial obstruction and patients are likely to respond to conservative treatment. Other studies have suggested that the administration of water-soluble contrast is therapeutic in resolving the obstruction. To determine the reliability of water-soluble contrast media and serial abdominal radiographs in predicting the success of conservative treatment in patients admitted with adhesive small bowel obstruction.Furthermore, to determine the efficacy and safety of water-soluble contrast media in reducing the need for surgical intervention and reducing hospital stay in adhesive small bowel obstruction. The search was conducted using MESH terms: ''Intestinal obstruction'', ''water-soluble contrast'', "Adhesions" and "Gastrografin". The later combined with the Cochrane Collaboration highly sensitive search strategy for identifying randomised controlled trials and controlled clinical trials. 1. Prospective studies were included to evaluate the diagnostic potential of water-soluble contrast in adhesive small bowel obstruction.2. Randomised clinical trials were selected to evaluate the therapeutic role. 1. Studies that addressed the diagnostic role of water-soluble contrast were critically appraised and data presented as sensitivities, specificities and positive and negative likelihood ratios. Results were pooled and summary ROC curve was constructed.2. A meta-analysis of the data from therapeutic studies was performed using the Mantel -Henszel test using both the fixed effect and random effect models. The appearance of water-soluble contrast in the colon on an abdominal X ray within 24 hours of its administration predicts resolution of an adhesive small bowel obstruction with a pooled sensitivity of 0.97, specificity of 0.96. The area under the curve of the summary ROC curve is 0.98. Six randomised studies dealing with the therapeutic role of gastrografin were included in the review, water-soluble contrast did not reduce the need for surgical intervention (OR 0.81, p = 0.3). Meta-analysis of four of the included studies showed that water-soluble contrast did reduce hospital stay compared with placebo (WMD= - 1.83) P<0.001. Published literature strongly supports the use of water-soluble contrast as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not cause resolution of small bowel obstruction there is strong evidence that it reduces hospital stay in those not requiring surgery.

Selecting Temperature for Protein Crystallization Screens Using the Temperature Dependence of the Second Virial Coefficient

PubMed Central

Liu, Jun; Yin, Da-Chuan; Guo, Yun-Zhu; Wang, Xi-Kai; Xie, Si-Xiao; Lu, Qin-Qin; Liu, Yong-Ming

2011-01-01

Protein crystals usually grow at a preferable temperature which is however not known for a new protein. This paper reports a new approach for determination of favorable crystallization temperature, which can be adopted to facilitate the crystallization screening process. By taking advantage of the correlation between the temperature dependence of the second virial coefficient (B 22) and the solubility of protein, we measured the temperature dependence of B 22 to predict the temperature dependence of the solubility. Using information about solubility versus temperature, a preferred crystallization temperature can be proposed. If B 22 is a positive function of the temperature, a lower crystallization temperature is recommended; if B 22 shows opposite behavior with respect to the temperature, a higher crystallization temperature is preferred. Otherwise, any temperature in the tested range can be used. PMID:21479212

Drug solubility in lipid nanocarriers: Influence of lipid matrix and available interfacial area.

PubMed

Göke, Katrin; Bunjes, Heike

2017-08-30

Amongst other strategies for the formulation of poorly water-soluble drugs, solubilization of these drugs in lipid-based formulations is a promising option. Most screening methods for the identification of a suitable lipid-based formulation fail to elucidate the role interfacial effects play for drug solubility in disperse systems. In a novel screening approach called passive drug loading, different preformed lipid nanocarrier dispersions are incubated with drug powder. Afterwards, undissolved drug is filtered off and the amount of solubilized drug is determined. The aim of this study was to identify parameters for drug solubility in pure lipids as well as for drug loading to the lipid-water interface of lipid nanoparticles. Using passive loading, the solubility of eight poorly water-soluble drugs in seven lipid nanocarriers varying in particle size or lipid matrix was investigated. Drug solubility in the nanocarriers did not follow any apparent trend and different drugs dissolved best in different carriers. Drugs with a melting point below approximately 150°C displayed distinctly better solubility than higher melting drugs. Additionally, relating the specific lipid nanocarrier surface area to the drug solubility allowed drawing conclusions on the drug localization. Fenofibrate, dibucaine and, less distinctly also clotrimazole, which all melt below 150°C, were predominantly located in the lipid droplet core of the nanoparticles. In contrast, the five remaining drugs (betamethasone valerate, flufenamic acid, itraconazole, ketoconazole, mefenamic acid) were also located at the lipid-water interface to different, but substantial degrees. The ability to account for drug loading to the lipid-water interface is thus a major advantage of passive loading. Copyright © 2017 Elsevier B.V. All rights reserved.

Designing a diverse high-quality library for crystallography-based FBDD screening.

PubMed

Tounge, Brett A; Parker, Michael H

2011-01-01

A well-chosen set of fragments is able to cover a large chemical space using a small number of compounds. The actual size and makeup of the fragment set is dependent on the screening method since each technique has its own practical limits in terms of the number of compounds that can be screened and requirements for compound solubility. In this chapter, an overview of the general requirements for a fragment library is presented for different screening platforms. In the case of the FBDD work at Johnson & Johnson Pharmaceutical Research and Development, L.L.C., our main screening technology is X-ray crystallography. Since every soaked protein crystal needs to be diffracted and a protein structure determined to delineate if a fragment binds, the size of our initial screening library cannot be a rate-limiting factor. For this reason, we have chosen 900 as the appropriate primary fragment library size. To choose the best set, we have developed our own mix of simple property ("Rule of 3") and "bad" substructure filtering. While this gets one a long way in terms of limiting the fragment pool, there are still tens of thousands of compounds to choose from after this initial step. Many of the choices left at this stage are not drug-like, so we have developed an FBDD Score to help select a 900-compound set. The details of this score and the filtering are presented. Copyright © 2011 Elsevier Inc. All rights reserved.

Selective staining of proteins with hydrophobic surface sites on a native electrophoretic gel.

PubMed

Bertsch, Martina; Kassner, Richard J

2003-01-01

Chemical proteomics aims to characterize all of the proteins in the proteome with respect to their function, which is associated with their interaction with other molecules. We propose the identification of a subproteomic library of expressed proteins whose native structures are typified by the presence of hydrophobic surface sites, which are often involved in interactions with small molecules, membrane lipids, and other proteins, pertaining to their functions. We demonstrate that soluble globular proteins with hydrophobic surface sites can be detected selectively by staining on an electrophoretic gel run under nondenaturing conditions. The application of these staining techniques may help elucidate new catalytic, transport, and regulatory functionalities in complex proteomic screenings.

Polyamidoamine Dendrimers for Enhanced Solubility of Small Molecules and Other Desirable Properties for Site Specific Delivery: Insights from Experimental and Computational Studies.

PubMed

Shadrack, Daniel M; Swai, Hulda S; Munissi, Joan J E; Mubofu, Egid B; Nyandoro, Stephen S

2018-06-12

Clinical applications of many small molecules are limited due to poor solubility and lack of controlled release besides lack of other desirable properties. Experimental and computational studies have reported on the therapeutic potential of polyamidoamine (PAMAM) dendrimers as solubility enhancers in pre-clinical and clinical settings. Besides formulation strategies, factors such as pH, PAMAM dendrimer generation, PAMAM dendrimer concentration, nature of the PAMAM core, special ligand and surface modifications of PAMAM dendrimer have an influence on drug solubility and other recommendable pharmacological properties. This review, therefore, compiles the recently reported applications of PAMAM dendrimers in pre-clinical and clinical uses as enhancers of solubility and other desirable properties such as sustained and controlled release, bioavailability, bio-distribution, toxicity reduction or enhancement, and targeted delivery of small molecules with emphasis on cancer treatment.

Method For Determining And Modifying Protein/Peptide Solubilty

DOEpatents

Waldo, Geoffrey S.

2005-03-15

A solubility reporter for measuring a protein's solubility in vivo or in vitro is described. The reporter, which can be used in a single living cell, gives a specific signal suitable for determining whether the cell bears a soluble version of the protein of interest. A pool of random mutants of an arbitrary protein, generated using error-prone in vitro recombination, may also be screened for more soluble versions using the reporter, and these versions may be recombined to yield variants having further-enhanced solubility. The method of the present invention includes "irrational" (random mutagenesis) methods, which do not require a priori knowledge of the three-dimensional structure of the protein of interest. Multiple sequences of mutation/genetic recombination and selection for improved solubility are demonstrated to yield versions of the protein which display enhanced solubility.

High drug loading self-microemulsifying/micelle formulation: design by high-throughput formulation screening system and in vivo evaluation.

PubMed

Sakai, Kenichi; Obata, Kouki; Yoshikawa, Mayumi; Takano, Ryusuke; Shibata, Masaki; Maeda, Hiroyuki; Mizutani, Akihiko; Terada, Katsuhide

2012-10-01

To design a high drug loading formulation of self-microemulsifying/micelle system. A poorly-soluble model drug (CH5137291), 8 hydrophilic surfactants (HS), 10 lipophilic surfactants (LS), 5 oils, and PEG400 were used. A high loading formulation was designed by a following stepwise approach using a high-throughput formulation screening (HTFS) system: (1) an oil/solvent was selected by solubility of the drug; (2) a suitable HS for highly loading was selected by the screenings of emulsion/micelle size and phase stability in binary systems (HS, oil/solvent) with increasing loading levels; (3) a LS that formed a broad SMEDDS/micelle area on a phase diagram containing the HS and oil/solvent was selected by the same screenings; (4) an optimized formulation was selected by evaluating the loading capacity of the crystalline drug. Aqueous solubility behavior and oral absorption (Beagle dog) of the optimized formulation were compared with conventional formulations (jet-milled, PEG400). As an optimized formulation, d-α-tocopheryl polyoxyethylene 1000 succinic ester: PEG400 = 8:2 was selected, and achieved the target loading level (200 mg/mL). The formulation formed fine emulsion/micelle (49.1 nm), and generated and maintained a supersaturated state at a higher level compared with the conventional formulations. In the oral absorption test, the area under the plasma concentration-time curve of the optimized formulation was 16.5-fold higher than that of the jet-milled formulation. The high loading formulation designed by the stepwise approach using the HTFS system improved the oral absorption of the poorly-soluble model drug.

Fiberboard created using the natural adhesive properties of distillers dried grains with solubles

USDA-ARS?s Scientific Manuscript database

Distillers dried grains with solubles (DDGS) were employed as a bio-based resin/adhesive. DDGS were defatted with hexane, ball ground and screened prior to use. DDGS flour was mixed dry with Paulownia wood (PW) to make composites using the following conditions: temperature of 150-195 oC, PW particle...

Construction and use of a Cupriavidus necator H16 soluble hydrogenase promoter (PSH) fusion to gfp (green fluorescent protein)

PubMed Central

Jugder, Bat-Erdene; Welch, Jeffrey; Braidy, Nady

2016-01-01

Hydrogenases are metalloenzymes that reversibly catalyse the oxidation or production of molecular hydrogen (H2). Amongst a number of promising candidates for application in the oxidation of H2 is a soluble [Ni–Fe] uptake hydrogenase (SH) produced by Cupriavidus necator H16. In the present study, molecular characterisation of the SH operon, responsible for functional SH synthesis, was investigated by developing a green fluorescent protein (GFP) reporter system to characterise PSH promoter activity using several gene cloning approaches. A PSH promoter-gfp fusion was successfully constructed and inducible GFP expression driven by the PSH promoter under de-repressing conditions in heterotrophic growth media was demonstrated in the recombinant C. necator H16 cells. Here we report the first successful fluorescent reporter system to study PSH promoter activity in C. necator H16. The fusion construct allowed for the design of a simple screening assay to evaluate PSH activity. Furthermore, the constructed reporter system can serve as a model to develop a rapid fluorescent based reporter for subsequent small-scale process optimisation experiments for SH expression. PMID:27547572

Novel furosemide cocrystals and selection of high solubility drug forms.

PubMed

Goud, N Rajesh; Gangavaram, Swarupa; Suresh, Kuthuru; Pal, Sharmistha; Manjunatha, Sulur G; Nambiar, Sudhir; Nangia, Ashwini

2012-02-01

Furosemide was screened in cocrystallization experiments with pharmaceutically acceptable coformer molecules to discover cocrystals of improved physicochemical properties, that is high solubility and good stability. Eight novel equimolar cocrystals of furosemide were obtained by liquid-assisted grinding with (i) caffeine, (ii) urea, (iii) p-aminobenzoic acid, (iv) acetamide, (v) nicotinamide, (vi) isonicotinamide, (vii) adenine, and (viii) cytosine. The product crystalline phases were characterized by powder x-ray diffraction, differential scanning calorimetry, infrared, Raman, near IR, and (13) C solid-state NMR spectroscopy. Furosemide-caffeine was characterized as a neutral cocrystal and furosemide-cytosine an ionic salt by single crystal x-ray diffraction. The stability of furosemide-caffeine, furosemide-adenine, and furosemide-cytosine was comparable to the reference drug in 10% ethanol-water slurry; there was no evidence of dissociation of the cocrystal to furosemide for up to 48 h. The other five cocrystals transformed to furosemide within 24 h. The solubility order for the stable forms is furosemide-cytosine > furosemide-adenine > furosemide-caffeine, and their solubilities are approximately 11-, 7-, and 6-fold higher than furosemide. The dissolution rates of furosemide cocrystals were about two times faster than the pure drug. Three novel furosemide compounds of higher solubility and good phase stability were identified in a solid form screen. Copyright © 2011 Wiley Periodicals, Inc.

Framework for the rapid optimization of soluble protein expression in Escherichia coli combining microscale experiments and statistical experimental design.

PubMed

Islam, R S; Tisi, D; Levy, M S; Lye, G J

2007-01-01

A major bottleneck in drug discovery is the production of soluble human recombinant protein in sufficient quantities for analysis. This problem is compounded by the complex relationship between protein yield and the large number of variables which affect it. Here, we describe a generic framework for the rapid identification and optimization of factors affecting soluble protein yield in microwell plate fermentations as a prelude to the predictive and reliable scaleup of optimized culture conditions. Recombinant expression of firefly luciferase in Escherichia coli was used as a model system. Two rounds of statistical design of experiments (DoE) were employed to first screen (D-optimal design) and then optimize (central composite face design) the yield of soluble protein. Biological variables from the initial screening experiments included medium type and growth and induction conditions. To provide insight into the impact of the engineering environment on cell growth and expression, plate geometry, shaking speed, and liquid fill volume were included as factors since these strongly influence oxygen transfer into the wells. Compared to standard reference conditions, both the screening and optimization designs gave up to 3-fold increases in the soluble protein yield, i.e., a 9-fold increase overall. In general the highest protein yields were obtained when cells were induced at a relatively low biomass concentration and then allowed to grow slowly up to a high final biomass concentration, >8 g.L-1. Consideration and analysis of the model results showed 6 of the original 10 variables to be important at the screening stage and 3 after optimization. The latter included the microwell plate shaking speeds pre- and postinduction, indicating the importance of oxygen transfer into the microwells and identifying this as a critical parameter for subsequent scale translation studies. The optimization process, also known as response surface methodology (RSM), predicted there to be a distinct optimum set of conditions for protein expression which could be verified experimentally. This work provides a generic approach to protein expression optimization in which both biological and engineering variables are investigated from the initial screening stage. The application of DoE reduces the total number of experiments needed to be performed, while experimentation at the microwell scale increases experimental throughput and reduces cost.

Improving the apo-state detergent stability of NTS1 with CHESS for pharmacological and structural studies.

PubMed

Scott, Daniel J; Kummer, Lutz; Egloff, Pascal; Bathgate, Ross A D; Plückthun, Andreas

2014-11-01

The largest single class of drug targets is the G protein-coupled receptor (GPCR) family. Modern high-throughput methods for drug discovery require working with pure protein, but this has been a challenge for GPCRs, and thus the success of screening campaigns targeting soluble, catalytic protein domains has not yet been realized for GPCRs. Therefore, most GPCR drug screening has been cell-based, whereas the strategy of choice for drug discovery against soluble proteins is HTS using purified proteins coupled to structure-based drug design. While recent developments are increasing the chances of obtaining GPCR crystal structures, the feasibility of screening directly against purified GPCRs in the unbound state (apo-state) remains low. GPCRs exhibit low stability in detergent micelles, especially in the apo-state, over the time periods required for performing large screens. Recent methods for generating detergent-stable GPCRs, however, offer the potential for researchers to manipulate GPCRs almost like soluble enzymes, opening up new avenues for drug discovery. Here we apply cellular high-throughput encapsulation, solubilization and screening (CHESS) to the neurotensin receptor 1 (NTS1) to generate a variant that is stable in the apo-state when solubilized in detergents. This high stability facilitated the crystal structure determination of this receptor and also allowed us to probe the pharmacology of detergent-solubilized, apo-state NTS1 using robotic ligand binding assays. NTS1 is a target for the development of novel antipsychotics, and thus CHESS-stabilized receptors represent exciting tools for drug discovery. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of binding pH and protein solubility on the dynamic binding capacity in hydrophobic interaction chromatography.

PubMed

Baumann, Pascal; Baumgartner, Kai; Hubbuch, Jürgen

2015-05-29

Hydrophobic interaction chromatography (HIC) is one of the most frequently used purification methods in biopharmaceutical industry. A major drawback of HIC, however, is the rather low dynamic binding capacity (DBC) obtained when compared to e.g. ion exchange chromatography (IEX). The typical purification procedure for HIC includes binding at neutral pH, independently of the proteins nature and isoelectric point. Most approaches to process intensification are based on resin and salt screenings. In this paper a combination of protein solubility data and varying binding pH leads to a clear enhancement of dynamic binding capacity. This is shown for three proteins of acidic, neutral, and alkaline isoelectric points. High-throughput solubility screenings as well as miniaturized and parallelized breakthrough curves on Media Scout RoboColumns (Atoll, Germany) were conducted at pH 3-10 on a fully automated robotic workstation. The screening results show a correlation between the DBC and the operational pH, the protein's isoelectric point and the overall solubility. Also, an inverse relationship of DBC in HIC and the binding kinetics was observed. By changing the operational pH, the DBC could be increased up to 30% compared to the standard purification procedure performed at neutral pH. As structural changes of the protein are reported during HIC processes, the applied samples and the elution fractions were proven not to be irreversibly unfolded. Copyright © 2015 Elsevier B.V. All rights reserved.

Development and validation of in silico models for estimating drug preformulation risk in PEG400/water and Tween80/water systems.

PubMed

Crivori, Patrizia; Morelli, Amedea; Pezzetta, Daniele; Rocchetti, Maurizio; Poggesi, Italo

2007-11-01

Solubility is one of the most important properties of drug candidates for achieving the targeted plasma concentrations following oral dosing. Furthermore, the formulations adopted in the in vivo preclinical studies, for both oral and intravenous administrations, are usually solutions. To formulate compounds sparingly soluble in water, pharmaceutically acceptable cosolvents or surfactants are typically employed to increase solubility. Compounds poorly soluble also in these systems will likely show severe formulation issues. In such cases, relatively high amount of compounds, rarely available in the early preclinical phases, are needed to identify the most appropriate dosing vehicles. Hence, the purpose of this study was to build two computational models which, on the basis of the molecular structure, are able to predict the compound solubility in two vehicle systems (40% PEG400/water and 10% Tween80/water) used in our company as screening tools for anticipating potential formulation issues. The two models were developed using the solubility data obtained from the analysis of approximately 2000 chemically diverse compounds. The structural diversity and the drug-like space covered by these molecules were investigated using the ChemGPS methodology. The compounds were classified (high/low preformulation risk) based on the experimental solubility value range. A combination of descriptors (i.e. logD at two different pH, E-state indices and other 2D structural descriptors) was correlated to these classes using partial least squares discriminant (PLSD) analysis. The overall accuracy of each PLSD model applied to independent sets of compounds was approximately 78%. The accuracy reached when the models were used in combination to identify molecules with low preformulation risk in both systems was 83%. The models appeared a valuable tool for predicting the preformulation risk of drug candidates and consequently for identifying the most appropriate dosing vehicles to be further investigated before the first in vivo preclinical studies. Since only a small number of 2D descriptors is need to evaluate the preformulation risk classes, the models resulted easy to use and characterized by high throughput.

A method for estimating both the solubility parameters and molar volumes of liquids

NASA Technical Reports Server (NTRS)

Fedors, R. F.

1974-01-01

Development of an indirect method of estimating the solubility parameter of high molecular weight polymers. The proposed method of estimating the solubility parameter, like Small's method, is based on group additive constants, but is believed to be superior to Small's method for two reasons: (1) the contribution of a much larger number of functional groups have been evaluated, and (2) the method requires only a knowledge of structural formula of the compound.

Solvent Vapor Annealing of Amorphous Carbamazepine Films for Fast Polymorph Screening and Dissolution Alteration.

PubMed

Schrode, Benedikt; Bodak, Brigitta; Riegler, Hans; Zimmer, Andreas; Christian, Paul; Werzer, Oliver

2017-09-30

Solubility enhancement and thus higher bioavailability are of great importance and a constant challenge in pharmaceutical research whereby polymorph screening and selection is one of the most important tasks. A very promising approach for polymorph screening is solvent vapor annealing where a sample is exposed to an atmosphere saturated with molecules of a specific chemical/solvent. In this work, amorphous carbamazepine thin films were prepared by spin coating, and the transformation into crystalline forms under exposure to solvent vapors was investigated. Employing grazing incidence X-ray diffraction, four distinct carbamazepine polymorphs, a solvate, and hydrates could be identified, while optical microscopy showed mainly spherulitic morphologies. In vitro dissolution experiments revealed different carbamazepine release from the various thin-film samples containing distinct polymorphic compositions: heat treatment of amorphous samples at 80 °C results in an immediate release; samples exposed to EtOH vapors show a drug release about 5 times slower than this immediate one; and all the others had intermediate release profiles. Noteworthy, even the sample of slowest release has a manifold faster release compared to a standard powder sample demonstrating the capabilities of thin-film preparation for faster drug release in general. Despite the small number of samples in this screening experiment, the results clearly show how solvent vapor annealing can assist in identifying potential polymorphs and allows for estimating their impact on properties like bioavailability.

Detection of Sickle Cell Hemoglobin in Haiti by Genotyping and Hemoglobin Solubility Tests

PubMed Central

Carter, Tamar E.; von Fricken, Michael; Romain, Jean R.; Memnon, Gladys; St. Victor, Yves; Schick, Laura; Okech, Bernard A.; Mulligan, Connie J.

2014-01-01

Sickle cell disease is a growing global health concern because infants born with the disorder in developing countries are now surviving longer with little access to diagnostic and management options. In Haiti, the current state of sickle cell disease/trait in the population is unclear. To inform future screening efforts in Haiti, we assayed sickle hemoglobin mutations using traditional hemoglobin solubility tests (HST) and add-on techniques, which incorporated spectrophotometry and insoluble hemoglobin separation. We also generated genotype data as a metric for HST performance. We found 19 of 202 individuals screened with HST were positive for sickle hemoglobin, five of whom did not carry the HbS allele. We show that spectrophotometry and insoluble hemoglobin separation add-on techniques could resolve false positives associated with the traditional HST approach, with some limitations. We also discuss the incorporation of insoluble hemoglobin separation observation with HST in suboptimal screening settings like Haiti. PMID:24957539

Discovery of potent inhibitors of soluble epoxide hydrolase by combinatorial library design and structure-based virtual screening.

PubMed

Xing, Li; McDonald, Joseph J; Kolodziej, Steve A; Kurumbail, Ravi G; Williams, Jennifer M; Warren, Chad J; O'Neal, Janet M; Skepner, Jill E; Roberds, Steven L

2011-03-10

Structure-based virtual screening was applied to design combinatorial libraries to discover novel and potent soluble epoxide hydrolase (sEH) inhibitors. X-ray crystal structures revealed unique interactions for a benzoxazole template in addition to the conserved hydrogen bonds with the catalytic machinery of sEH. By exploitation of the favorable binding elements, two iterations of library design based on amide coupling were employed, guided principally by the docking results of the enumerated virtual products. Biological screening of the libraries demonstrated as high as 90% hit rate, of which over two dozen compounds were single digit nanomolar sEH inhibitors by IC(50) determination. In total the library design and synthesis produced more than 300 submicromolar sEH inhibitors. In cellular systems consistent activities were demonstrated with biochemical measurements. The SAR understanding of the benzoxazole template provides valuable insights into discovery of novel sEH inhibitors as therapeutic agents.

Solubility of ocular therapeutic agents in self-emulsifying oils. I. Self-emulsifying oils for ocular drug delivery: solubility of indomethacin, aciclovir and hydrocortisone.

PubMed

Czajkowska-Kośnik, Anna; Sznitowska, Małgorzata

2009-01-01

Self-emulsifying drug delivery systems (SEDDS) were prepared by dissolving Cremophor EL, Tween 20, Tween 80 and Span 80 (1% or 5%) in oils (Miglyol 812 or castor oil). Solubilities of three ophthalmic drugs, namely aciclovir, hydrocortisone and indomethacin were determined in these systems. In addition, the effect of a small amount of water (0.5% and 2%) on solubilization properties of the systems was estimated. Of the three substances, indomethacin showed the best solubility in Miglyol while aciclovir was practically insoluble in this oil. The surfactants usually increased drug solubility in the oily phase. Only Tween 20 was found to decrease the solubility of aciclovir and hydrocortisone in Miglyol. Addition of a small amount of water to the oil/surfactant system increased solubility of hydrocortisone, but not of indomethacin. The results of the current study may be utilized to design a suitable composition of SEDDS and allow continuation of research on this type of drug carriers.

Polymorph Impact on the Bioavailability and Stability of Poorly Soluble Drugs.

PubMed

Censi, Roberta; Di Martino, Piera

2015-10-15

Drugs with low water solubility are predisposed to poor and variable oral bioavailability and, therefore, to variability in clinical response, that might be overcome through an appropriate formulation of the drug. Polymorphs (anhydrous and solvate/hydrate forms) may resolve these bioavailability problems, but they can be a challenge to ensure physicochemical stability for the entire shelf life of the drug product. Since clinical failures of polymorph drugs have not been uncommon, and some of them have been entirely unexpected, the Food and Drug Administration (FDA) and the International Conference on Harmonization (ICH) has required preliminary and exhaustive screening studies to identify and characterize all the polymorph crystal forms for each drug. In the past, the polymorphism of many drugs was detected fortuitously or through manual time consuming methods; today, drug crystal engineering, in particular, combinatorial chemistry and high-throughput screening, makes it possible to easily and exhaustively identify stable polymorphic and/or hydrate/dehydrate forms of poorly soluble drugs, in order to overcome bioavailability related problems or clinical failures. This review describes the concepts involved, provides examples of drugs characterized by poor solubility for which polymorphism has proven important, outlines the state-of-the-art technologies and discusses the pertinent regulations.

Synthesis and structure-activity relationship of piperidine-derived non-urea soluble epoxide hydrolase inhibitors

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

Pecic, Stevan; Pakhomova, Svetlana; Newcomer, Marcia E.

2013-09-27

A series of potent amide non-urea inhibitors of soluble epoxide hydrolase (sEH) is disclosed. The inhibition of soluble epoxide hydrolase leads to elevated levels of epoxyeicosatrienoic acids (EETs), and thus inhibitors of sEH represent one of a novel approach to the development of vasodilatory and anti-inflammatory drugs. Structure–activities studies guided optimization of a lead compound, identified through high-throughput screening, gave rise to sub-nanomolar inhibitors of human sEH with stability in human liver microsomal assay suitable for preclinical development.

Speciation and bioaccessibility of mercury in adobe bricks and dirt floors in Huancavelica, Peru.

PubMed

Hagan, Nicole; Robins, Nicholas; Gonzales, Ruben Dario Espinoza; Hsu-Kim, Heileen

2015-04-01

Huancavelica, Peru, a historic cinnabar refining site, is one of the most mercury (Hg)-contaminated urban areas in the world. Exposure is amplified because residents build their adobe brick homes from contaminated soil. The objectives of this study were to compare two Hg-leaching procedures, and their application as risk-assessment screening tools in Hg-contaminated adobe brick homes in Huancavelica. The purpose was to evaluate potential health implications, particularly for children, after ingestion of Hg-contaminated particles. Hg was measured in adobe brick and dirt floor samples from 60 households by total Hg extraction, simulated gastric fluid (GF) extraction, and sequential selective extraction (SSE), which provides more detailed data but is resource-intensive. Most of the Hg present in samples was relatively insoluble, although in some households soluble Hg species were present at concentrations that may be of concern after ingestion. A strong correlation was identified between results from simulated GF extraction of adobe bricks and dirt floors and the more soluble fractions of Hg from SSE. Simulated GF extraction data were combined with ingestion and body mass characteristics for small children to compare potential risk of ingestion of Hg-contaminated soil with current health standards. Simulated GF extraction can be used as a risk assessment screening tool for effective allocation of time and resources to households that have measurable concentrations of bioaccessible Hg. Combining simulated GF extraction data with health standards enables intervention strategies targeted at households with the greatest potential health threat from ingestion of Hg-contaminated particles.

Thermal processing of a poorly water-soluble drug substance exhibiting a high melting point: the utility of KinetiSol® Dispersing.

PubMed

Hughey, Justin R; Keen, Justin M; Brough, Chris; Saeger, Sophie; McGinity, James W

2011-10-31

Poorly water-soluble drug substances that exhibit high melting points are often difficult to successfully process by fusion-based techniques. The purpose of this study was to identify a suitable polymer system for meloxicam (MLX), a high melting point class II BCS compound, and investigate thermal processing techniques for the preparation of chemically stable single phase solid dispersions. Thermal and solution based screening techniques were utilized to screen hydrophilic polymers suitable for immediate release formulations. Results of the screening studies demonstrated that Soluplus(®)(SOL) provided the highest degree of miscibility and solubility enhancement. A hot-melt extrusion feasibility study demonstrated that high temperatures and extended residence times were required in order to render compositions amorphous, causing significant degradation of MLX. A design of experiments (DOE) was conducted on the KinetiSol(®) Dispersing (KSD) process to evaluate the effect of processing conditions on the chemical stability and amorphous character of MLX. The study demonstrated that ejection temperature significantly impacted MLX stability. All samples prepared by KSD were substantially amorphous. Dissolution analysis of the KSD processed solid dispersions showed increased dissolution rates and extent of supersaturation over the marketed generic MLX tablets. Copyright © 2011 Elsevier B.V. All rights reserved.

A high-throughput immobilized bead screen for stable proteins and multi-protein complexes

PubMed Central

Lockard, Meghan A.; Listwan, Pawel; Pedelacq, Jean-Denis; Cabantous, Stéphanie; Nguyen, Hau B.; Terwilliger, Thomas C.; Waldo, Geoffrey S.

2011-01-01

We describe an in vitro colony screen to identify Escherichia coli expressing soluble proteins and stable, assembled multiprotein complexes. Proteins with an N-terminal 6His tag and C-terminal green fluorescent protein (GFP) S11 tag are fluorescently labeled in cells by complementation with a coexpressed GFP 1–10 fragment. After partial colony lysis, the fluorescent soluble proteins or complexes diffuse through a supporting filtration membrane and are captured on Talon® resin metal affinity beads immobilized in agarose. Images of the fluorescent colonies convey total expression and the level of fluorescence bound to the beads indicates how much protein is soluble. Both pieces of information can be used together when selecting clones. After the assay, colonies can be picked and propagated, eliminating the need to make replica plates. We used the method to screen a DNA fragment library of the human protein p85 and preferentially obtained clones expressing the full-length ‘breakpoint cluster region-homology' and NSH2 domains. The assay also distinguished clones expressing stable multi-protein complexes from those that are unstable due to missing subunits. Clones expressing stable, intact heterotrimeric E.coli YheNML complexes were readily identified in libraries dominated by complexes of YheML missing the N subunit. PMID:21642284

Angiotensin II receptor type 1--a novel target for preventing neonatal meningitis in mice by Escherichia coli K1.

PubMed

Krishnan, Subramanian; Shanmuganathan, Muthusamy V; Behenna, Douglas; Stoltz, Brian M; Prasadarao, Nemani V

2014-02-01

The increasing incidence of Escherichia coli K1 meningitis due to escalating antibiotic resistance warrants alternate treatment options to prevent this deadly disease. We screened a library of small molecules from the National Institutes of Health clinical collection and identified telmisartan, an angiotensin II receptor type 1 (AT1R) blocker, as a potent inhibitor of E. coli invasion into human brain microvascular endothelial cells (HBMECs). Immunoprecipitation studies revealed that AT1R associates with endothelial cell gp96, the receptor in HBMECs for E. coli outer membrane protein A. HBMECs pretreated with telmisartan or transfected with AT1R small interfering RNA were resistant to E. coli invasion because of downregulation of protein kinase C-α phosphorylation. Administration of a soluble derivative of telmisartan to newborn mice before infection with E. coli prevented the onset of meningitis and suppressed neutrophil infiltration and glial cell migration in the brain. Therefore, telmisartan has potential as an alternate treatment option for preventing E. coli meningitis.

Discovery of 8-Membered Ring Sulfonamides as Inhibitors of Oncogenic Mutant Isocitrate Dehydrogenase 1.

PubMed

Law, Jason M; Stark, Sebastian C; Liu, Ke; Liang, Norah E; Hussain, Mahmud M; Leiendecker, Matthias; Ito, Daisuke; Verho, Oscar; Stern, Andrew M; Johnston, Stephen E; Zhang, Yan-Ling; Dunn, Gavin P; Shamji, Alykhan F; Schreiber, Stuart L

2016-10-13

Evidence suggests that specific mutations of isocitrate dehydrogenases 1 and 2 (IDH1/2) are critical for the initiation and maintenance of certain tumor types and that inhibiting these mutant enzymes with small molecules may be therapeutically beneficial. In order to discover mutant allele-selective IDH1 inhibitors with chemical features distinct from existing probes, we screened a collection of small molecules derived from diversity-oriented synthesis. The assay identified compounds that inhibit the IDH1-R132H mutant allele commonly found in glioma. Here, we report the discovery of a potent (IC 50 = 50 nM) series of IDH1-R132H inhibitors having 8-membered ring sulfonamides as exemplified by the compound BRD2879. The inhibitors suppress ( R )-2-hydroxyglutarate production in cells without apparent toxicity. Although the solubility and pharmacokinetic properties of the specific inhibitor BRD2879 prevent its use in vivo , the scaffold presents a validated starting point for the synthesis of future IDH1-R132H inhibitors having improved pharmacological properties.

Bioconcentration factors and lipid solubility

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

Banerjee, S.; Baughman, G.L.

1991-03-01

The log-log relationship between bioconcentration and hydrophobicity breaks down for several medium and high molecular weight solutes that bioconcentrate either to a small extent or not at all. Much of the failure is attributed to the relatively low solubility of these compounds in lipid. Inclusion of a term in octanol solubility (in place of lipid solubility, which is generally unavailable) considerably improves the quality of the relationship (r = 0.95). It is speculated that the octanol solubility term compensates for the relatively low solubility of large compounds in lipid.

A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in Sorghum bicolor

PubMed Central

2013-01-01

Background A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total fermentable sugar yields including stalk biomass, soluble sugar concentrations, and cell wall saccharification efficiency. Results A mathematical method for assessing whole S. bicolor stalks using the fourth internode from the base of the plant proved to be an effective high-throughput strategy for assessing stalk biomass, soluble sugar concentrations, and cell wall composition and allowed calculation of total stalk fermentable sugars. A high-throughput method for measuring soluble sucrose, glucose, and fructose using partial least squares (PLS) modelling of juice Fourier transform infrared (FTIR) spectra was developed. The PLS prediction was shown to be highly accurate with each sugar attaining a coefficient of determination (R 2 ) of 0.99 with a root mean squared error of prediction (RMSEP) of 11.93, 5.52, and 3.23 mM for sucrose, glucose, and fructose, respectively, which constitutes an error of <4% in each case. The sugar PLS model correlated well with gas chromatography–mass spectrometry (GC-MS) and brix measures. Similarly, a high-throughput method for predicting enzymatic cell wall digestibility using PLS modelling of FTIR spectra obtained from S. bicolor bagasse was developed. The PLS prediction was shown to be accurate with an R 2 of 0.94 and RMSEP of 0.64 μg.mgDW-1.h-1. Conclusions This methodology has been demonstrated as an efficient and effective way to screen large biofuel feedstock populations for biomass, soluble sugar concentrations, and cell wall digestibility simultaneously allowing a total fermentable yield calculation. It unifies and simplifies previous screening methodologies to produce a holistic assessment of biofuel feedstock potential. PMID:24365407

Synthetic Molecular Evolution of Membrane-Active Peptides

NASA Astrophysics Data System (ADS)

Wimley, William

The physical chemistry of membrane partitioning largely determines the function of membrane active peptides. Membrane-active peptides have potential utility in many areas, including in the cellular delivery of polar compounds, cancer therapy, biosensor design, and in antibacterial, antiviral and antifungal therapies. Yet, despite decades of research on thousands of known examples, useful sequence-structure-function relationships are essentially unknown. Because peptide-membrane interactions within the highly fluid bilayer are dynamic and heterogeneous, accounts of mechanism are necessarily vague and descriptive, and have little predictive power. This creates a significant roadblock to advances in the field. We are bypassing that roadblock with synthetic molecular evolution: iterative peptide library design and orthogonal high-throughput screening. We start with template sequences that have at least some useful activity, and create small, focused libraries using structural and biophysical principles to design the sequence space around the template. Orthogonal high-throughput screening is used to identify gain-of-function peptides by simultaneously selecting for several different properties (e.g. solubility, activity and toxicity). Multiple generations of iterative library design and screening have enabled the identification of membrane-active sequences with heretofore unknown properties, including clinically relevant, broad-spectrum activity against drug-resistant bacteria and enveloped viruses as well as pH-triggered macromolecular poration.

A reusable microfluidic plate with alternate-choice architecture for assessing growth preference in tissue culture.

PubMed

Wittig, John H; Ryan, Allen F; Asbeck, Peter M

2005-05-15

We present the design of a chamber to evaluate in vitro how species and concentrations of soluble molecules control features of cell growth-potentially including cell proliferation, cell motility, process extension, and process termination. We have created a reusable cell culture plate that integrates a microfluidic media delivery network with standard cell culture environment. The microfluidic network delivers a stream of cell culture media with a step-like concentration gradient down a 50-100 microm wide microchannel called the presentation region. Migrating cells or growing cell processes freely choose between the two distinct chemical environments in the presentation region, but they are forced to exclusively choose either one environment or the other when they grow past a physical barrier acting as a decision point. Our fabrication technique requires little specialized equipment, and can be carried out in approximately 4 days per plate. We demonstrate the effectiveness of our plates as neurites from spiral ganglion explants preferentially grow in media containing neurotrophin-3 (NT-3) as opposed to media without NT-3. Our design could be used without modification to study dissociated cell responses to soluble growth cues, and for behavioral screening of small motile organisms.

Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

PubMed

Botasini, S; Martí, A C; Méndez, E

2016-10-17

Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

[Effect of Psidium guajava leaf extract on alpha-glucosidase activity in small intestine of diabetic mouse].

PubMed

Wang, Bo; Liu, Heng-Chuan; Hong, Jun-Rong; Li, Hong-Gu; Huang, Cheng-Yu

2007-03-01

To investigate the inhibition effect of Psidium guajava linn (PGL), a leaf water-soluble extract, on the activities of alpha-glucosidases. The PGL water-soluble extract (PGL WE) was obtained by the procedure of distilled water immersion, filtration, extracted fluid concentration and dry of Psidium guajava leaf. The diabetes of Kunming mice was induced by intraperitoneal injection of Streptozotocin (STZ). The small intestinal mucosa of diabetic mice was scraped to make the homogenate for the preparation of alpha-glucosidases. In vitro, the homogenates were incubated with sucrose and maltose. The formed glucose represented the activities of alpha-glucosidases. The Lineweaver-Burk plot was applied to determine the type of alpha-glucosidase activity inhibited. The water-soluble extract from PGL significantly inhibited, in the dose-dependent manner, the activities of alpha-glucosidase from small intestinal mucosa of diabetic mice. The PGL extract inhibition concentration (IC50) to sucrase or maltase was 1.0 g/L or 3.0 g/L respectively. The mixed inhibition type was showed to be the competitive and non-competitive inhibition. The GPL water-soluble extract possesses the potential effect of inhibition on the alpha-glucosidase activity from the small intestinal mucosa of diabetic mouse.

Combinatorial screening of 3D biomaterial properties that promote myofibrogenesis for mesenchymal stromal cell-based heart valve tissue engineering.

PubMed

Usprech, Jenna; Romero, David A; Amon, Cristina H; Simmons, Craig A

2017-08-01

The physical and chemical properties of a biomaterial integrate with soluble cues in the cell microenvironment to direct cell fate and function. Predictable biomaterial-based control of integrated cell responses has been investigated with two-dimensional (2D) screening platforms, but integrated responses in 3D have largely not been explored systematically. To address this need, we developed a screening platform using polyethylene glycol norbornene (PEG-NB) as a model biomaterial with which the polymer wt% (to control elastic modulus) and adhesion peptide types (RGD, DGEA, YIGSR) and densities could be controlled independently and combinatorially in arrays of 3D hydrogels. We applied this platform and regression modeling to identify combinations of biomaterial and soluble biochemical (TGF-β1) factors that best promoted myofibrogenesis of human mesenchymal stromal cells (hMSCs) in order to inform our understanding of regenerative processes for heart valve tissue engineering. In contrast to 2D culture, our screens revealed that soft hydrogels (low PEG-NB wt%) best promoted spread myofibroblastic cells that expressed high levels of α-smooth muscle actin (α-SMA) and collagen type I. High concentrations of RGD enhanced α-SMA expression in the presence of TGF-β1 and cell spreading regardless of whether TGF-β1 was in the culture medium. Strikingly, combinations of peptides that maximized collagen expression depended on the presence or absence of TGF-β1, indicating that biomaterial properties can modulate MSC response to soluble signals. This combination of a 3D biomaterial array screening platform with statistical modeling is broadly applicable to systematically identify combinations of biomaterial and microenvironmental conditions that optimally guide cell responses. We present a novel screening platform and methodology to model and identify how combinations of biomaterial and microenvironmental conditions guide cell phenotypes in 3D. Our approach to systematically identify complex relationships between microenvironmental cues and cell responses enables greater predictive power over cell fate in conditions with interacting material design factors. We demonstrate that this approach not only predicts that mesenchymal stromal cell (MSC) myofibrogenesis is promoted by soft, porous 3D biomaterials, but also generated new insights which demonstrate how biomaterial properties can differentially modulate MSC response to soluble signals. An additional benefit of the process includes utilizing both parametric and non parametric analyses which can demonstrate dominant significant trends as well as subtle interactions between biochemical and biomaterial cues. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Preparation and evaluation of self-microemulsifying drug delivery system containing vinpocetine.

PubMed

Cui, Shu-Xia; Nie, Shu-Fang; Li, Li; Wang, Chang-Guang; Pan, Wei-San; Sun, Jian-Ping

2009-05-01

The main purpose of current investigation is to prepare a self-microemulsifying drug delivery system (SMEDDS) to enhance the oral bioavailability of vinpocetine, a poorly water-soluble drug. Suitable vehicles were screened by determining the solubility of vinpocetine in them. Certain surfactants were selected according to their emulsifying ability with different oils. Ternary phase diagrams were used to identify the efficient self-microemulsifying region and to screen the effect of surfactant/cosurfactant ratio (K(m)). The optimized formulation for in vitro dissolution and bioavailability assessment was oil (ethyl oleate, 15%), surfactant (Solutol HS 15, 50%), and cosurfactant (Transcutol P, 35%). The release rate of vinpocetine from SMEDDS was significantly higher than that of the commercial tablet. Pharmacokinetics and bioavailability of SMEDDS were evaluated. It was found that the oral bioavailability of vinpocetine of SMEDDS was 1.72-fold higher as compared with that of the commercial tablet. These results obtained demonstrated that vinpocetine absorption was enhanced significantly by employing SMEDDS. Therefore, SMEDDS might provide an efficient way of improving oral bioavailability of poorly water-soluble drugs.

A Versatile System for High-Throughput In Situ X-ray Screening and Data Collection of Soluble and Membrane-Protein Crystals

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

Broecker, Jana; Klingel, Viviane; Ou, Wei-Lin

In recent years, in situ data collection has been a major focus of progress in protein crystallography. Here, we introduce the Mylar in situ method using Mylar-based sandwich plates that are inexpensive, easy to make and handle, and show significantly less background scattering than other setups. A variety of cognate holders for patches of Mylar in situ sandwich films corresponding to one or more wells makes the method robust and versatile, allows for storage and shipping of entire wells, and enables automated crystal imaging, screening, and goniometerbased X-ray diffraction data-collection at room temperature and under cryogenic conditions for soluble andmore » membrane-protein crystals grown in or transferred to these plates. We validated the Mylar in situ method using crystals of the water-soluble proteins hen egg-white lysozyme and sperm whale myoglobin as well as the 7-transmembrane protein bacteriorhodopsin from Haloquadratum walsbyi. In conjunction with current developments at synchrotrons, this approach promises high-resolution structural studies of membrane proteins to become faster and more routine.« less

Aqueous solubility, effects of salts on aqueous solubility, and partitioning behavior of hexafluorobenzene: experimental results and COSMO-RS predictions.

PubMed

Schröder, Bernd; Freire, Mara G; Varanda, Fatima R; Marrucho, Isabel M; Santos, Luís M N B F; Coutinho, João A P

2011-07-01

The aqueous solubility of hexafluorobenzene has been determined, at 298.15K, using a shake-flask method with a spectrophotometric quantification technique. Furthermore, the solubility of hexafluorobenzene in saline aqueous solutions, at distinct salt concentrations, has been measured. Both salting-in and salting-out effects were observed and found to be dependent on the nature of the cationic/anionic composition of the salt. COSMO-RS, the Conductor-like Screening Model for Real Solvents, has been used to predict the corresponding aqueous solubilities at conditions similar to those used experimentally. The prediction results showed that the COSMO-RS approach is suitable for the prediction of salting-in/-out effects. The salting-in/-out phenomena have been rationalized with the support of COSMO-RS σ-profiles. The prediction potential of COSMO-RS regarding aqueous solubilities and octanol-water partition coefficients has been compared with typically used QSPR-based methods. Up to now, the absence of accurate solubility data for hexafluorobenzene hampered the calculation of the respective partition coefficients. Combining available accurate vapor pressure data with the experimentally determined water solubility, a novel air-water partition coefficient has been derived. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multilayer white lighting polymer light-emitting diodes

NASA Astrophysics Data System (ADS)

Gong, Xiong; Wang, Shu; Heeger, Alan J.

2006-08-01

Organic and polymer light-emitting diodes (OLEDs/PLEDs) that emit white light are of interest and potential importance for use in active matrix displays (with color filters) and because they might eventually be used for solid-state lighting. In such applications, large-area devices and low-cost of manufacturing will be major issues. We demonstrated that high performance multilayer white emitting PLEDs can be fabricated by using a blend of luminescent semiconducting polymers and organometallic complexes as the emission layer, and water-soluble (or ethanol-soluble) polymers/small molecules (for example, PVK-SO 3Li) as the hole injection/transport layer (HIL/HTL) and water-soluble (or ethanol-soluble) polymers/small molecules (for example, t-Bu-PBD-SO 3Na) as the electron injection/transport layer (EIL/HTL). Each layer is spin-cast sequentially from solutions. Illumination quality light is obtained with stable Commission Internationale d'Eclairage coordinates, stable color temperatures, and stable high color rendering indices, all close to those of "pure" white. The multilayer white-emitting PLEDs exhibit luminous efficiency of 21 cd/A, power efficiency of 6 lm/W at a current density of 23 mA/cm2 with luminance of 5.5 x 10 4 cd/m2 at 16 V. By using water-soluble (ethanol-soluble) polymers/small molecules as HIL/HTL and polymers/small molecules as EIL/ETL, the interfacial mixing problem is solved (the emissive polymer layer is soluble in organic solvents, but not in water/ ethanol). As a result, this device architecture and process technology can potentially be used for printing large-area multiplayer light sources and for other applications in "plastic" electronics. More important, the promise of producing large areas of high quality white light with low-cost manufacturing technology makes the white multilayer white-emitting PLEDs attractive for the development of solid state light sources.

Potential of soluble CD26 as a serum marker for colorectal cancer detection

PubMed Central

Cordero, Oscar J; Imbernon, Monica; Chiara, Loretta De; Martinez-Zorzano, Vicenta S; Ayude, Daniel; de la Cadena, Maria Paez; Rodriguez-Berrocal, F Javier

2011-01-01

Colorectal cancer is characterized by a low survival rate even though the basis for colon cancer development, which involves the evolution of adenomas to carcinoma, is known. Moreover, the mortality rates continue to rise in economically transitioning countries although there is the opportunity to intervene in the natural history of the adenoma–cancer sequence through risk factors, screening, and treatment. Screening in particular accounted for most of the decline in colorectal cancer mortality achieved in the USA during the period 1975-2000. Patients show a better prognosis when the neoplasm is diagnosed early. Among the variety of screening strategies, the methods range from invasive and costly procedures such as colonoscopy to more low-cost and non-invasive tests such as the fecal occult blood test (guaiac and immunochemical). As a non-invasive biological serum marker would be of great benefit because of the performance of the test, several biomarkers, including cytologic assays, DNA and mRNA, and soluble proteins, have been studied. We found that the soluble CD26 (sCD26) concentration is diminished in serum of colorectal cancer patients compared to healthy donors, suggesting the potential utility of a sCD26 immunochemical detection test for early diagnosis. sCD26 originates from plasma membrane CD26 lacking its transmembrane and cytoplasmic domains. Some 90%–95% of sCD26 has been associated with serum dipeptidyl peptidase IV (DPP-IV) activity. DPP-IV, assigned to the CD26 cluster, is a pleiotropic enzyme expressed mainly on epithelial cells and lymphocytes. Our studies intended to validate this test for population screening to detect colorectal cancer and advanced adenomas are reviewed here. PMID:21773075

Carrier characteristics influence the kinetics of passive drug loading into lipid nanoemulsions.

PubMed

Göke, Katrin; Bunjes, Heike

2018-05-01

Passive loading as a novel screening approach is a material-saving tool for the efficient selection of a suitable colloidal lipid carrier system for poorly water soluble drug candidates. This method comprises incubation of preformed carrier systems with drug powder and subsequent determination of the resulting drug load of the carrier particles after removal of excess drug. For reliable routine use and to obtain meaningful loading results, information on the kinetics of the process is required. Passive loading proceeds via a dissolution-diffusion-based mechanism, where drug surface area and drug water solubility are key parameters for fast passive loading. While the influence of the drug characteristics is mostly understood, the influence of the carrier characteristics remains unknown. The aim of this study was to examine how the lipid nanocarriers' characteristics, i.e. the type of lipid, the lipid content and the particle size, influence the kinetics of passive loading. Fenofibrate was used as model drug and the loading progress was analyzed by UV spectroscopy. The saturation solubility in the nanocarrier particles, i.e. the lipid type, did not influence the passive loading rate constant. Low lipid content in the nanocarrier and a small nanocarrier particle size both increased passive loading speed. Both variations increase the diffusivity of the nanocarrier particles, which is the primary cause for fast loading at these conditions: The quicker the carrier particles diffuse, the higher is the speed of passive loading. The influence of the diffusivity of the lipid nanocarriers and the effect of drug dissolution rate were included in an overall mechanistic model developed for similar processes (A. Balakrishnan, B.D. Rege, G.L. Amidon, J.E. Polli, Surfactant-mediated dissolution: contributions of solubility enhancement and relatively low micelle diffusivity, J. Pharm. Sci. 93 (2004) 2064-2075). The resulting mechanistic model gave a good estimate of the speed of passive loading in nanoemulsions. Whilst the drug's characteristics - apart from drug surface area - are basically fixed, the lipid nanocarriers can be customized to improve passive loading speed, e.g. by using small nanocarrier particles. The knowledge of the loading mechanism now allows the use of passive loading for the straightforward, material-saving selection of suitable lipid drug nanocarriers. Copyright © 2017 Elsevier B.V. All rights reserved.

High throughput screening of CO2 solubility in aqueous monoamine solutions.

PubMed

Porcheron, Fabien; Gibert, Alexandre; Mougin, Pascal; Wender, Aurélie

2011-03-15

Post-combustion Carbon Capture and Storage technology (CCS) is viewed as an efficient solution to reduce CO(2) emissions of coal-fired power stations. In CCS, an aqueous amine solution is commonly used as a solvent to selectively capture CO(2) from the flue gas. However, this process generates additional costs, mostly from the reboiler heat duty required to release the carbon dioxide from the loaded solvent solution. In this work, we present thermodynamic results of CO(2) solubility in aqueous amine solutions from a 6-reactor High Throughput Screening (HTS) experimental device. This device is fully automated and designed to perform sequential injections of CO(2) within stirred-cell reactors containing the solvent solutions. The gas pressure within each reactor is monitored as a function of time, and the resulting transient pressure curves are transformed into CO(2) absorption isotherms. Solubility measurements are first performed on monoethanolamine, diethanolamine, and methyldiethanolamine aqueous solutions at T = 313.15 K. Experimental results are compared with existing data in the literature to validate the HTS device. In addition, a comprehensive thermodynamic model is used to represent CO(2) solubility variations in different classes of amine structures upon a wide range of thermodynamic conditions. This model is used to fit the experimental data and to calculate the cyclic capacity, which is a key parameter for CO(2) process design. Solubility measurements are then performed on a set of 50 monoamines and cyclic capacities are extracted using the thermodynamic model, to asses the potential of these molecules for CO(2) capture.

Hierarchical virtual screening approaches in small molecule drug discovery.

PubMed

Kumar, Ashutosh; Zhang, Kam Y J

2015-01-01

Virtual screening has played a significant role in the discovery of small molecule inhibitors of therapeutic targets in last two decades. Various ligand and structure-based virtual screening approaches are employed to identify small molecule ligands for proteins of interest. These approaches are often combined in either hierarchical or parallel manner to take advantage of the strength and avoid the limitations associated with individual methods. Hierarchical combination of ligand and structure-based virtual screening approaches has received noteworthy success in numerous drug discovery campaigns. In hierarchical virtual screening, several filters using ligand and structure-based approaches are sequentially applied to reduce a large screening library to a number small enough for experimental testing. In this review, we focus on different hierarchical virtual screening strategies and their application in the discovery of small molecule modulators of important drug targets. Several virtual screening studies are discussed to demonstrate the successful application of hierarchical virtual screening in small molecule drug discovery. Copyright © 2014 Elsevier Inc. All rights reserved.

Meta-analysis of oral water-soluble contrast agent in the management of adhesive small bowel obstruction.

PubMed

Abbas, S M; Bissett, I P; Parry, B R

2007-04-01

Adhesions are the leading cause of small bowel obstruction. Identification of patients who require surgery is difficult. This review analyses the role of Gastrografin as a diagnostic and therapeutic agent in the management of adhesive small bowel obstruction. A systematic search of Medline, Embase and Cochrane databases was performed to identify studies of the use of Gastrografin in adhesive small bowel obstruction. Studies that addressed the diagnostic role of water-soluble contrast agent were appraised, and data presented as sensitivity, specificity, and positive and negative likelihood ratios. Results were pooled and a summary receiver-operator characteristic (ROC) curve was constructed. A meta-analysis of the data from six therapeutic studies was performed using the Mantel-Haenszel test and both fixed- and random-effect models. The appearance of water-soluble contrast agent in the colon on an abdominal radiograph within 24 h of its administration predicted resolution of obstruction with a pooled sensitivity of 97 per cent and specificity of 96 per cent. The area under the summary ROC curve was 0.98. Water-soluble contrast agent did not reduce the need for surgical intervention (odds ratio 0.81, P = 0.300), but it did reduce the length of hospital stay for patients who did not require surgery compared with placebo (weighted mean difference--1.84 days; P < 0.001). Published data strongly support the use of water-soluble contrast medium as a predictive test for non-operative resolution of adhesive small bowel obstruction. Although Gastrografin does not reduce the need for operation, it appears to shorten the hospital stay for those who do not require surgery.

48 CFR 719.271-6 - Small business screening procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Small business screening... DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271-6 Small business screening...) Preparation of Form USAID 1410-14 (the Small Business/Minority Business Enterprise Procurement Review Form...

Curcumin-loaded self-nanomicellizing solid dispersion system: part I: development, optimization, characterization, and oral bioavailability.

PubMed

Parikh, Ankit; Kathawala, Krishna; Song, Yunmei; Zhou, Xin-Fu; Garg, Sanjay

2018-05-29

Curcumin (CUR) is considered as one of the most bioactive molecules ever discovered from nature due to its proven anti-inflammatory and antioxidant in both preclinical and clinical studies. Despite its proven safety and efficacy, the clinical translation of CUR into a useful therapeutic agent is still limited due to its poor oral bioavailability. To overcome its limitation and enhance oral bioavailability by improving its aqueous solubility, stability, and intestinal permeability, a novel CUR formulation (NCF) was developed using the self-nanomicellizing solid dispersion strategy. From the initial screening of polymers for their potential to improve the solubility and stability, Soluplus (SOL) was selected. The optimized NCF demonstrated over 20,000-fold improvement in aqueous solubility as a result of amorphization, hydrogen bonding interaction, and micellization determined using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance, dynamic light scattering, and transmission electron microscopy. Moreover, the greater stabilizing effect in alkaline pH and light was observed. Furthermore, significant enhancement of dissolution and permeability of CUR across everted sacs of rat small intestine were noticed. Pharmacokinetic studies demonstrated that the oral bioavailability of CUR was increased 117 and 17-fold in case of NCF and physical mixture of CUR and SOL compared to CUR suspension. These results suggest NCF identified as a promising new approach for repositioning of CUR for pharmaceutical application by enhancing the oral bioavailability of CUR. The findings herein stimulate further in vivo evaluations and clinical tests of NCF.

Angiotensin II Receptor Type 1—A Novel Target for Preventing Neonatal Meningitis in Mice by Escherichia coli K1

PubMed Central

Krishnan, Subramanian; Shanmuganathan, Muthusamy V.; Behenna, Douglas; Stoltz, Brian M.; Prasadarao, Nemani V.

2014-01-01

The increasing incidence of Escherichia coli K1 meningitis due to escalating antibiotic resistance warrants alternate treatment options to prevent this deadly disease. We screened a library of small molecules from the National Institutes of Health clinical collection and identified telmisartan, an angiotensin II receptor type 1 (AT1R) blocker, as a potent inhibitor of E. coli invasion into human brain microvascular endothelial cells (HBMECs). Immunoprecipitation studies revealed that AT1R associates with endothelial cell gp96, the receptor in HBMECs for E. coli outer membrane protein A. HBMECs pretreated with telmisartan or transfected with AT1R small interfering RNA were resistant to E. coli invasion because of downregulation of protein kinase C-α phosphorylation. Administration of a soluble derivative of telmisartan to newborn mice before infection with E. coli prevented the onset of meningitis and suppressed neutrophil infiltration and glial cell migration in the brain. Therefore, telmisartan has potential as an alternate treatment option for preventing E. coli meningitis. PMID:24041786

Simple modification of basic dyes with bulky &symmetric WCAs for improving their solubilities in organic solvents without color change.

PubMed

Kim, Jeong Yun; Hwang, Tae Gyu; Woo, Sung Wun; Lee, Jae Moon; Namgoong, Jin Woong; Yuk, Sim Bum; Chung, Sei-Won; Kim, Jae Pil

2017-04-06

A simple and easy solubility enhancement of basic dyes was performed with bulky and symmetric weakly coordinating anions (WCAs). The WCAs decreased the ionic character of the dyes by broadening the partial charge distribution and causing a screening effect on the ionic bonding. This new modification with WCAs has advantages in that it has no influence on the optical properties of the dyes. The solubilities of unmodified and modified dyes were tested in several organic solvents. X-ray powder diffraction patterns of the dyes were measured. Color films were prepared with the dyes and their color loci were analyzed to evaluate the optical properties. By the modification with WCAs, commercial basic dyes showed sufficient solubilities for be applied to various applications while preserving their superior optical properties.

Label-Free Fluorescence Assay of S1 Nuclease and Hydroxyl Radicals Based on Water-Soluble Conjugated Polymers and WS₂ Nanosheets.

PubMed

Li, Junting; Zhao, Qi; Tang, Yanli

2016-06-13

We developed a new method for detecting S1 nuclease and hydroxyl radicals based on the use of water-soluble conjugated poly[9,9-bis(6,6-(N,N,N-trimethylammonium)-fluorene)-2,7-ylenevinylene-co-alt-2,5-dicyano-1,4-phenylene)] (PFVCN) and tungsten disulfide (WS₂) nanosheets. Cationic PFVCN is used as a signal reporter, and single-layer WS₂ is used as a quencher with a negatively charged surface. The ssDNA forms complexes with PFVCN due to much stronger electrostatic interactions between cationic PFVCN and anionic ssDNA, whereas PFVCN emits yellow fluorescence. When ssDNA is hydrolyzed by S1 nuclease or hydroxyl radicals into small fragments, the interactions between the fragmented DNA and PFVCN become weaker, resulting in PFVCN being adsorbed on the surface of WS₂ and the fluorescence being quenched through fluorescence resonance energy transfer. The new method based on PFVCN and WS₂ can sense S1 nuclease with a low detection limit of 5 × 10(-6) U/mL. Additionally, this method is cost-effective by using affordable WS₂ as an energy acceptor without the need for dye-labeled ssDNA. Furthermore, the method provides a new platform for the nuclease assay and reactive oxygen species, and provides promising applications for drug screening.

Occurrence of urea-based soluble epoxide hydrolase inhibitors from the plants in the order Brassicales

PubMed Central

Kitamura, Seiya; Morisseau, Christophe; Harris, Todd R.; Inceoglu, Bora

2017-01-01

Recently, dibenzylurea-based potent soluble epoxide hydrolase (sEH) inhibitors were identified in Pentadiplandra brazzeana, a plant in the order Brassicales. In an effort to generalize the concept, we hypothesized that plants that produce benzyl glucosinolates and corresponding isothiocyanates also produce these dibenzylurea derivatives. Our overall aim here was to examine the occurrence of urea derivatives in Brassicales, hoping to find biologically active urea derivatives from plants. First, plants in the order Brassicales were analyzed for the presence of 1, 3-dibenzylurea (compound 1), showing that three additional plants in the order Brassicales produce the urea derivatives. Based on the hypothesis, three dibenzylurea derivatives with sEH inhibitory activity were isolated from maca (Lepidium meyenii) roots. Topical application of one of the identified compounds (compound 3, human sEH IC50 = 222 nM) effectively reduced pain in rat inflammatory pain model, and this compound was bioavailable after oral administration in mice. The biosynthetic pathway of these urea derivatives was investigated using papaya (Carica papaya) seed as a model system. Finally, a small collection of plants from the Brassicales order was grown, collected, extracted and screened for sEH inhibitory activity. Results show that several plants of the Brassicales order could be potential sources of urea-based sEH inhibitors. PMID:28472063

Oral formulation strategies to improve solubility of poorly water-soluble drugs.

PubMed

Singh, Abhishek; Worku, Zelalem Ayenew; Van den Mooter, Guy

2011-10-01

In the past two decades, there has been a spiraling increase in the complexity and specificity of drug-receptor targets. It is possible to design drugs for these diverse targets with advances in combinatorial chemistry and high throughput screening. Unfortunately, but not entirely unexpectedly, these advances have been accompanied by an increase in the structural complexity and a decrease in the solubility of the active pharmaceutical ingredient. Therefore, the importance of formulation strategies to improve the solubility of poorly water-soluble drugs is inevitable, thus making it crucial to understand and explore the recent trends. Drug delivery systems (DDS), such as solid dispersions, soluble complexes, self-emulsifying drug delivery systems (SEDDS), nanocrystals and mesoporous inorganic carriers, are discussed briefly in this review, along with examples of marketed products. This article provides the reader with a concise overview of currently relevant formulation strategies and proposes anticipated future trends. Today, the pharmaceutical industry has at its disposal a series of reliable and scalable formulation strategies for poorly soluble drugs. However, due to a lack of understanding of the basic physical chemistry behind these strategies, formulation development is still driven by trial and error.

Use of amino acids as counterions improves the solubility of the BCS II model drug, indomethacin.

PubMed

ElShaer, Amr; Khan, Sheraz; Perumal, Dhaya; Hanson, Peter; Mohammed, Afzal R

2011-07-01

The number of new chemical entities (NCE) is increasing every day after the introduction of combinatorial chemistry and high throughput screening to the drug discovery cycle. One third of these new compounds have aqueous solubility less than 20µg/mL [1]. Therefore, a great deal of interest has been forwarded to the salt formation technique to overcome solubility limitations. This study aims to improve the drug solubility of a Biopharmaceutical Classification System class II (BCS II) model drug (Indomethacin; IND) using basic amino acids (L-arginine, L-lysine and L-histidine) as counterions. Three new salts were prepared using freeze drying method and characterised by FT-IR spectroscopy, proton nuclear magnetic resonance ((1)HNMR), Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). The effect of pH on IND solubility was also investigated using pH-solubility profile. Both arginine and lysine formed novel salts with IND, while histidine failed to dissociate the free acid and in turn no salt was formed. Arginine and lysine increased IND solubility by 10,000 and 2296 fold, respectively. An increase in dissolution rate was also observed for the novel salts. Since these new salts have improved IND solubility to that similar to BCS class I drugs, IND salts could be considered for possible waivers of bioequivalence.

Thermal precipitation fluorescence assay for protein stability screening.

PubMed

Fan, Junping; Huang, Bo; Wang, Xianping; Zhang, Xuejun C

2011-09-01

A simple and reliable method of protein stability assessment is desirable for high throughput expression screening of recombinant proteins. Here we described an assay termed thermal precipitation fluorescence (TPF) which can be used to compare thermal stabilities of recombinant protein samples directly from cell lysate supernatants. In this assay, target membrane proteins are expressed as recombinant fusions with a green fluorescence protein tag and solubilized with detergent, and the fluorescence signals are used to report the quantity of the fusion proteins in the soluble fraction of the cell lysate. After applying a heat shock, insoluble protein aggregates are removed by centrifugation. Subsequently, the amount of remaining protein in the supernatant is quantified by in-gel fluorescence analysis and compared to samples without a heat shock treatment. Over 60 recombinant membrane proteins from Escherichia coli were subject to this screening in the presence and absence of a few commonly used detergents, and the results were analyzed. Because no sophisticated protein purification is required, this TPF technique is suitable to high throughput expression screening of recombinant membrane proteins as well as soluble ones and can be used to prioritize target proteins based on their thermal stabilities for subsequent large scale expression and structural studies. Copyright © 2011 Elsevier Inc. All rights reserved.

Prediction of solubilities for ginger bioactive compounds in hot water by the COSMO-RS method

NASA Astrophysics Data System (ADS)

Zaimah Syed Jaapar, Syaripah; Azian Morad, Noor; Iwai, Yoshio

2013-04-01

The solubilities in water of four main ginger bioactives, 6-gingerol, 6-shogaol, 8-gingerol and 10-gingerol, were predicted using a conductor-like screening model for real solvent (COSMO-RS) calculations. This study was conducted since no experimental data are available for ginger bioactive solubilities in hot water. The σ-profiles of these selected molecules were calculated using Gaussian software and the solubilities were calculated using the COSMO-RS method. The solubilities of these ginger bioactives were calculated at 50 to 200 °C. In order to validate the accuracy of the COSMO-RS method, the solubilities of five hydrocarbon molecules were calculated using the COSMO-RS method and compared with the experimental data in the literature. The selected hydrocarbon molecules were 3-pentanone, 1-hexanol, benzene, 3-methylphenol and 2-hydroxy-5-methylbenzaldehyde. The calculated results of the hydrocarbon molecules are in good agreement with the data in the literature. These results confirm that the solubilities of ginger bioactives can be predicted using the COSMO-RS method. The solubilities of the ginger bioactives are lower than 0.0001 at temperatures lower than 130 °C. At 130 to 200 °C, the solubilities increase dramatically with the highest being 6-shogaol, which is 0.00037 mole fraction, and the lowest is 10-gingerol, which is 0.000039 mole fraction at 200 °C.

Drug nanoparticles: formulating poorly water-soluble compounds.

PubMed

Merisko-Liversidge, Elaine M; Liversidge, Gary G

2008-01-01

More than 40% of compounds identified through combinatorial screening programs are poorly soluble in water. These molecules are difficult to formulate using conventional approaches and are associated with innumerable formulation-related performance issues. Formulating these compounds as pure drug nanoparticles is one of the newer drug-delivery strategies applied to this class of molecules. Nanoparticle dispersions are stable and have a mean diameter of less than 1 micron. The formulations consist of water, drug, and one or more generally regarded as safe excipients. These liquid dispersions exhibit an acceptable shelf-life and can be postprocessed into various types of solid dosage forms. Drug nanoparticles have been shown to improve bioavailability and enhance drug exposure for oral and parenteral dosage forms. Suitable formulations for the most commonly used routes of administration can be identified with milligram quantities of drug substance, providing the discovery scientist with an alternate avenue for screening and identifying superior analogs. For the toxicologist, the approach provides a means for dose escalation using a formulation that is commercially viable. In the past few years, formulating poorly water-soluble compounds using a nanoparticulate approach has evolved from a conception to a realization whose versatility and applicability are just beginning to be realized.

Constructing Chimeric Antigen for Precise Screening of HTLV-I Infection.

PubMed

Heydari Zarnagh, Hafez; Hassanpour, Kazem; Rasaee, Mohammad Javad

2015-08-01

Individual preparation of two human T-cell lymphotropic virus type I (HTLV-I) diagnostic GST fused peptides (MTA-1 and GD21) is time-consuming and expensive. The aim of this study was to design a novel single chimeric antigen (SCA) to obviate separate expression of proteins and reduce the cost of reagent preparation. Structural protein fragments, including immunodominant B cell linear epitopes, were selected and different SCAs were designed. Tertiary structure, epitope exposure, solubility and stability were calculated for each SCA and compared with each other. The synthetic DNA encoding the interested SCA was sub-cloned into pET32a expression vector, expressed as a soluble form in Escherichia coli BL21 (DE3) cells and purified under native condition using affinity chromatography. The SDS-PAGE results indicated that thioredoxin-fused SCA was successfully expressed as a soluble form in E. coli BL21 (DE3) cells. The results of ELISA confirmed that SCA reacted with anti-HTLV-I antibodies in a concentration-dependent manner. Our results indicated that the designed SCA may be a good candidate for the screening of HTLV-I carriers with antigen-antibody-based tests.

Drug-drug cocrystals of antituberculous 4-aminosalicylic acid: Screening, crystal structures, thermochemical and solubility studies.

PubMed

Drozd, Ksenia V; Manin, Alex N; Churakov, Andrei V; Perlovich, German L

2017-03-01

Experimental multistage cocrystal screening of the antituberculous drug 4-aminosalicylic acid (PASA) has been conducted with a number of coformers (pyrazinamide (PYR), nicotinamide (NAM), isonicotinamide (iNAM), isoniazid (INH), caffeine (CAF) and theophylline (TPH)). The crystal structures of 4-aminosalicylic acid cocrystals with isonicotinamide ([PASA+iNAM] (2:1)) and methanol solvate with caffeine ([PASA+CAF+MeOH] (1:1:1)) have been determined by single X-ray diffraction experiments. For the first time for PASA cocrystals it has been found that the structural unit of the [PASA+iNAM] cocrystal (2:1) is formed by 2 types of heterosynthons: acid-pyridine and acid-amide. The desolvation study of the [PASA+CAF+MeOH] cocrystal solvate (1:1:1) has been conducted. The correlation models linking the melting points of the cocrystals with the melting points of the coformers used in this paper have been developed. The thermochemical and solubility properties for all the obtained cocrystals have been studied. Cocrystallization has been shown to lead not only to PASA solubility improving but also to its higher stability against the chemical decomposition. Copyright © 2016 Elsevier B.V. All rights reserved.

Species specific identification of spore-producing microbes using the gene sequence of small acid-soluble spore coat proteins for amplification based diagnostics

DOEpatents

McKinney, Nancy

2002-01-01

PCR (polymerase chain reaction) primers for the detection of certain Bacillus species, such as Bacillus anthracis. The primers specifically amplify only DNA found in the target species and can distinguish closely related species. Species-specific PCR primers for Bacillus anthracis, Bacillus globigii and Clostridium perfringens are disclosed. The primers are directed to unique sequences within sasp (small acid soluble protein) genes.

Self-assembled nanoparticle of common food constituents that carries a sparingly soluble small molecule.

PubMed

Bhopatkar, Deepak; Feng, Tao; Chen, Feng; Zhang, Genyi; Carignano, Marcelo; Park, Sung Hyun; Zhuang, Haining; Campanella, Osvaldo H; Hamaker, Bruce R

2015-05-06

A previously reported nanoparticle formed through the self-assembly of common food constituents (amylose, protein, and fatty acids) was shown to have the capacity to carry a sparingly soluble small molecule (1-naphthol) in a dispersed system. Potentiometric titration showed that 1-naphthol locates in the lumen of the amylose helix of the nanoparticle. This finding was further supported by calorimetric measurements, showing higher enthalpies of dissociation and reassociation in the presence of 1-naphthol. Visually, the 1-naphthol-loaded nanoparticle appeared to be well-dispersed in aqueous solution. Molecular dynamics simulation showed that the self-assembly was favorable, and at 500 ns, the 1-naphthol molecule resided in the helix of the amylose lumen in proximity to the hydrophobic tail of the fatty acid. Thus, sparingly soluble small molecules, such as some nutraceuticals or drugs, could be incorporated and delivered by this soft nanoparticle carrier.

Insight into small molecule binding to the neonatal Fc receptor by X-ray crystallography and 100 kHz magic-angle-spinning NMR

PubMed Central

Macpherson, Alex; Smith-Penzel, Susanne; Basse, Nicolas; Lecomte, Fabien; Deboves, Hervé; Taylor, Richard D.; Norman, Tim; Porter, John; Waters, Lorna C.; Westwood, Marta; Cossins, Ben; Cain, Katharine; White, James; Griffin, Robert; Prosser, Christine; Kelm, Sebastian; Sullivan, Amy H.; Fox, David; Carr, Mark D.; Henry, Alistair; Taylor, Richard; Meier, Beat H.; Oschkinat, Hartmut; Lawson, Alastair D.

2018-01-01

Aiming at the design of an allosteric modulator of the neonatal Fc receptor (FcRn)–Immunoglobulin G (IgG) interaction, we developed a new methodology including NMR fragment screening, X-ray crystallography, and magic-angle-spinning (MAS) NMR at 100 kHz after sedimentation, exploiting very fast spinning of the nondeuterated soluble 42 kDa receptor construct to obtain resolved proton-detected 2D and 3D NMR spectra. FcRn plays a crucial role in regulation of IgG and serum albumin catabolism. It is a clinically validated drug target for the treatment of autoimmune diseases caused by pathogenic antibodies via the inhibition of its interaction with IgG. We herein present the discovery of a small molecule that binds into a conserved cavity of the heterodimeric, extracellular domain composed of an α-chain and β2-microglobulin (β2m) (FcRnECD, 373 residues). X-ray crystallography was used alongside NMR at 100 kHz MAS with sedimented soluble protein to explore possibilities for refining the compound as an allosteric modulator. Proton-detected MAS NMR experiments on fully protonated [13C,15N]-labeled FcRnECD yielded ligand-induced chemical-shift perturbations (CSPs) for residues in the binding pocket and allosteric changes close to the interface of the two receptor heterodimers present in the asymmetric unit as well as potentially in the albumin interaction site. X-ray structures with and without ligand suggest the need for an optimized ligand to displace the α-chain with respect to β2m, both of which participate in the FcRnECD–IgG interaction site. Our investigation establishes a method to characterize structurally small molecule binding to nondeuterated large proteins by NMR, even in their glycosylated form, which may prove highly valuable for structure-based drug discovery campaigns. PMID:29782488

Insight into small molecule binding to the neonatal Fc receptor by X-ray crystallography and 100 kHz magic-angle-spinning NMR.

PubMed

Stöppler, Daniel; Macpherson, Alex; Smith-Penzel, Susanne; Basse, Nicolas; Lecomte, Fabien; Deboves, Hervé; Taylor, Richard D; Norman, Tim; Porter, John; Waters, Lorna C; Westwood, Marta; Cossins, Ben; Cain, Katharine; White, James; Griffin, Robert; Prosser, Christine; Kelm, Sebastian; Sullivan, Amy H; Fox, David; Carr, Mark D; Henry, Alistair; Taylor, Richard; Meier, Beat H; Oschkinat, Hartmut; Lawson, Alastair D

2018-05-01

Aiming at the design of an allosteric modulator of the neonatal Fc receptor (FcRn)-Immunoglobulin G (IgG) interaction, we developed a new methodology including NMR fragment screening, X-ray crystallography, and magic-angle-spinning (MAS) NMR at 100 kHz after sedimentation, exploiting very fast spinning of the nondeuterated soluble 42 kDa receptor construct to obtain resolved proton-detected 2D and 3D NMR spectra. FcRn plays a crucial role in regulation of IgG and serum albumin catabolism. It is a clinically validated drug target for the treatment of autoimmune diseases caused by pathogenic antibodies via the inhibition of its interaction with IgG. We herein present the discovery of a small molecule that binds into a conserved cavity of the heterodimeric, extracellular domain composed of an α-chain and β2-microglobulin (β2m) (FcRnECD, 373 residues). X-ray crystallography was used alongside NMR at 100 kHz MAS with sedimented soluble protein to explore possibilities for refining the compound as an allosteric modulator. Proton-detected MAS NMR experiments on fully protonated [13C,15N]-labeled FcRnECD yielded ligand-induced chemical-shift perturbations (CSPs) for residues in the binding pocket and allosteric changes close to the interface of the two receptor heterodimers present in the asymmetric unit as well as potentially in the albumin interaction site. X-ray structures with and without ligand suggest the need for an optimized ligand to displace the α-chain with respect to β2m, both of which participate in the FcRnECD-IgG interaction site. Our investigation establishes a method to characterize structurally small molecule binding to nondeuterated large proteins by NMR, even in their glycosylated form, which may prove highly valuable for structure-based drug discovery campaigns.

Optimized formulation of solid self-microemulsifying sirolimus delivery systems

PubMed Central

Cho, Wonkyung; Kim, Min-Soo; Kim, Jeong-Soo; Park, Junsung; Park, Hee Jun; Cha, Kwang-Ho; Park, Jeong-Sook; Hwang, Sung-Joo

2013-01-01

Background The aim of this study was to develop an optimized solid self-microemulsifying drug delivery system (SMEDDS) formulation for sirolimus to enhance its solubility, stability, and bioavailability. Methods Excipients used for enhancing the solubility and stability of sirolimus were screened. A phase-separation test, visual observation for emulsifying efficiency, and droplet size analysis were performed. Ternary phase diagrams were constructed to optimize the liquid SMEDDS formulation. The selected liquid SMEDDS formulations were prepared into solid form. The dissolution profiles and pharmacokinetic profiles in rats were analyzed. Results In the results of the oil and cosolvent screening studies, Capryol™ Propylene glycol monocapry late (PGMC) and glycofurol exhibited the highest solubility of all oils and cosolvents, respectively. In the surfactant screening test, D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) was determined to be the most effective stabilizer of sirolimus in pH 1.2 simulated gastric fluids. The optimal formulation determined by the construction of ternary phase diagrams was the T32 (Capryol™ PGMC:glycofurol:vitamin E TPGS = 30:30:40 weight ratio) formulation with a mean droplet size of 108.2 ± 11.4 nm. The solid SMEDDS formulations were prepared with Sucroester 15 and mannitol. The droplet size of the reconstituted solid SMEDDS showed no significant difference compared with the liquid SMEDDS. In the dissolution study, the release amounts of sirolimus from the SMEDDS formulation were significantly higher than the raw sirolimus powder. In addition, the solid SMEDDS formulation was in a more stable state than liquid SMEDDS in pH 1.2 simulated gastric fluids. The results of the pharmacokinetic study indicate that the SMEDDS formulation shows significantly greater bioavailability than the raw sirolimus powder or commercial product (Rapamune® oral solution). Conclusion The results of this study suggest the potential use of a solid SMEDDS formulation for the delivery of poorly water-soluble drugs, such as sirolimus, through oral administration. PMID:23641156

Solubility, stability, and electrochemical studies of sulfur-sulfide solutions in organic solvents

NASA Technical Reports Server (NTRS)

Fielder, W. L.; Singer, J.

1978-01-01

A preliminary study of the sulfur electrode in organic solvents suggests that the system warrants further investigation for use in a low temperature (100 deg to 120 C) Na-S secondary battery. A qualitative screening was undertaken at 120 C to determine the solubilities and stabilities of Na2S and Na2S2 in representatives of many classes of organic solvents. From the screening and quantitative studies, two classes of solvents were selected for work; amides and cyclic polyalcohols. Voltammetric and Na-S cell charge discharge studies of sulfide solutions in organic solvents (e.g., N, N-dimethylformamide) at 120 C suggested that the reversibilities of the reactions on Pt or high density graphite were moderately poor. However, the sulfur electrode was indeed reducible (and oxidizable) through the range of elemental sulfur to Na2S. Reactions and mechanisms are proposed for the oxidation reduction processes occurring at the sulfur electrode.

Automated Analysis of a Nematode Population-based Chemosensory Preference Assay

PubMed Central

Chai, Cynthia M.; Cronin, Christopher J.; Sternberg, Paul W.

2017-01-01

The nematode, Caenorhabditis elegans' compact nervous system of only 302 neurons underlies a diverse repertoire of behaviors. To facilitate the dissection of the neural circuits underlying these behaviors, the development of robust and reproducible behavioral assays is necessary. Previous C. elegans behavioral studies have used variations of a "drop test", a "chemotaxis assay", and a "retention assay" to investigate the response of C. elegans to soluble compounds. The method described in this article seeks to combine the complementary strengths of the three aforementioned assays. Briefly, a small circle in the middle of each assay plate is divided into four quadrants with the control and experimental solutions alternately placed. After the addition of the worms, the assay plates are loaded into a behavior chamber where microscope cameras record the worms' encounters with the treated regions. Automated video analysis is then performed and a preference index (PI) value for each video is generated. The video acquisition and automated analysis features of this method minimizes the experimenter's involvement and any associated errors. Furthermore, minute amounts of the experimental compound are used per assay and the behavior chamber's multi-camera setup increases experimental throughput. This method is particularly useful for conducting behavioral screens of genetic mutants and novel chemical compounds. However, this method is not appropriate for studying stimulus gradient navigation due to the close proximity of the control and experimental solution regions. It should also not be used when only a small population of worms is available. While suitable for assaying responses only to soluble compounds in its current form, this method can be easily modified to accommodate multimodal sensory interaction and optogenetic studies. This method can also be adapted to assay the chemosensory responses of other nematode species. PMID:28745641

Development and Application of a Novel SPE-Method for Bioassay-Guided Fractionation of Marine Extracts

PubMed Central

Cutignano, Adele; Nuzzo, Genoveffa; Ianora, Adrianna; Luongo, Elvira; Romano, Giovanna; Gallo, Carmela; Sansone, Clementina; Aprea, Susanna; Mancini, Francesca; D’Oro, Ugo; Fontana, Angelo

2015-01-01

The biological diversity of marine habitats is a unique source of chemical compounds with potential use as pharmaceuticals, cosmetics and dietary supplements. However, biological screening and chemical analysis of marine extracts pose specific technical constraints and require adequate sample preparation. Here we report an improved method on Solid Phase Extraction (SPE) to fractionate organic extracts containing high concentration of salt that hampers the recovery of secondary metabolites. The procedure uses a water suspension to load the extracts on a poly(styrene-divynylbenzene)-based support and a stepwise organic solvent elution to effectively desalt and fractionate the organic components. The novel protocol has been tested on MeOH-soluble material from three model organisms (Reniera sarai, Dendrilla membranosa and Amphidinium carterae) and was validated on a small panel of 47 marine samples, including sponges and protists, within discovery programs for identification of immuno-stimulatory and anti-infective natural products. PMID:26378547

A novel oral vehicle for poorly soluble HSV-helicase inhibitors: PK/PD validations.

PubMed

Duan, Jianmin; Liard, Francine; Paris, William; Lambert, Michelle

2004-11-01

The current study describes the design and validation of a novel oral vehicle for delivering poorly water-soluble herpes simplex virus (HSV)-helicase inhibitors in preclinical pharmacokinetic (PK) and pharmacodynamic (PD) evaluations. Poorly water-soluble compounds were used in solubility and drinking compliance tests in mice. A preferred vehicle containing 0.1% bovine serum albumin (BSA), 3% dextrose, 5% polyethylene glycol (PEG) 400, and 2% peanut oil, pH 2.8 with HCL (BDPP) was selected. This vehicle was further validated with oral PK and in vivo antiviral PD studies using BILS 45 BS. Solubility screen and drinking compliance tests revealed that the BDPP vehicle could solubilize BILS compounds at 0.5-3 mg/ml concentration range and could be administered to mice without reducing water consumption. Comparative oral PK of BILS 45 BS in HCL or BDPP by gavage at 40 mg/kg showed overlapping PK profiles. In vivo antiviral efficacy and potency of BILS 45 BS in BDPP by oral gavages or in drinking water were confirmed to be comparable as that achieved by gavage in HCL solution. These results provide a protein-enriched novel oral vehicle for delivering poorly water-soluble antiviral compounds in a continuous administration mode. Similar approaches may be applicable to other poorly soluble compounds by gavage or in drinking solution.

Refolding Active Human DNA Polymerase ν from Inclusion Bodies

PubMed Central

Arana, Mercedes E.; Powell, Gary K.; Edwards, Lori L.; Kunkel, Thomas A.; Petrovich, Robert M.

2017-01-01

Human DNA polymerase ν (Pol ν) is a conserved family A DNA polymerase of uncertain biological function. Physical and biochemical characterization aimed at understanding Pol ν function is hindered by the fact that, when over-expressed in E. coli, Pol ν is largely insoluble, and the small amount of soluble protein is difficult to purify. Here we describe the use of high hydrostatic pressure to refold Pol ν from inclusion bodies, in soluble and active form. The refolded Pol ν has properties comparable to those of the small amount of Pol ν that was purified from the soluble fraction. The approach described here may be applicable to other DNA polymerases that are expressed as insoluble inclusion bodies in E. coli. PMID:19853037

Expression, purification and characterization of the receptor-binding domain of botulinum neurotoxin serotype B as a vaccine candidate.

PubMed

Ben David, Alon; Torgeman, Amram; Barnea, Ada; Zichel, Ran

2015-06-01

The receptor-binding domain of botulinum neurotoxins (the HC fragment) is a promising vaccine candidate. Among the HC fragments of the seven BoNT serotypes, the expression of HC/B in Escherichia coli is considered especially challenging due to its accumulation as a non-soluble protein aggregate. In this study, the effects of different parameters on the expression of soluble HC/B were evaluated using a screening assay that included growing the bacterium at a small scale, a chemical cell lysis step, and a specific ELISA. The highest soluble HC/B expression levels were obtained when the bacterium E. coli BL21(DE3)+pET-9a-HC/B was grown in terrific broth media at 18°C without induction. Under these conditions, the yield was an order of magnitude higher than previously reported. Standard purification of the protein using a nickel column resulted in a low purity of HC/B. However, the addition of an acidic wash step prior to protein elution released a major protein contaminant and significantly increased the purity level. Mass spectrometry analysis identified the contaminant as ArnA, an E. coli protein that often contaminates recombinant His-tagged protein preparations. The purified HC/B was highly immunogenic, protecting mice from a 10(6) LD50 challenge after a single vaccination and generating a neutralizing titer of 50IU/ml after three immunizations. Moreover, the functionality of the protein was preserved, as it inhibited BoNT/B intoxication in vivo, presumably due to blockade of the neurotoxin protein receptor synaptotagmin. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of a screening method to determine excipients which optimize the extent and stability of supersaturated drug solutions and application of this system to solid formulation design.

PubMed

Vandecruys, Roger; Peeters, Jef; Verreck, Geert; Brewster, Marcus E

2007-09-05

Assessing the effect of excipients on the ability to attain and maintain supersaturation of drug-based solution may provide useful information for the design of solid formulations. Judicious selection of materials that affect either the extent or stability of supersaturating drug delivery systems may be enabling for poorly soluble drug candidates or other difficult-to-formulate compounds. The technique suggested herein is aimed at providing a screening protocol to allow preliminary assessment of these factors based on small to moderate amounts of drug substance. A series of excipients were selected that may, by various mechanisms, affect supersaturation including pharmaceutical polymers such as HMPC and PVP, surfactants such as Polysorbate 20, Cremophor RH40 and TPGS and hydrophilic cyclodextrins such as HPbetaCD. Using a co-solvent based method and 25 drug candidates, the data suggested, on the whole, that the surfactants and the selected cyclodextrin seemed to best augment the extent of supersaturation but had variable benefits as stabilizers, while the pharmaceutical polymers had useful effect on supersaturation stability but were less helpful in increasing the extent of supersaturation. Using these data, a group of simple solid dosage forms were prepared and tested in the dog for one of the drug candidates. Excipients that gave the best extent and stability for the formed supersaturated solution in the screening assay also gave the highest oral bioavailability in the dog.

Preparation of monoclonal antibody bank against whole water-soluble proteins from rapid-growing bamboo shoots.

PubMed

Wu, Yu-Jen; Chen, Han-Min; Wu, Tai-Tse; Wu, Jiann-Shing; Chu, Rea-Min; Juang, Rong-Huay

2006-11-01

An antibody bank against the whole proteins in a proteome is a useful tool for biological research. Using the standard cell fusion method, and a modified screening protocol, we produced an mAb bank against the total water-soluble proteins extracted from the rapid-growing green bamboo shoots. An improved two-stage strategy was employed to enrich those poor immunogenic or lower expressed proteins. Totally, we obtained a bank of 192 mAb which were identified as distinctive to each other by 2-DE and immunostaining.

SFN-SIQ, SFNSL and skin biopsy of 55 cases with small fibre involvement.

PubMed

Sun, Bo; Li, Yifan; Liu, Lizhi; Chen, Zhaohui; Ling, Li; Yang, Fei; Liu, Jiexiao; Liu, Hong; Huang, Xusheng

2018-05-01

Purpose/aim of the study: To date, there are no validated screening scales for small fibre neuropathy. This study investigated the small-fibre neuropathy and the symptom inventory questionnaire as well as the small fibre neuropathy screening list for small fibre neuropathy diagnosis. Fifty-five patients were divided into small fibre neuropathy and mixed fibre damage groups. Relevant scales, nerve conduction studies and skin biopsies were performed. Relationships between the intraepidermal nerve fibre density and different scales as well as the diagnostic and cut-off values (score at which Youden's index is largest) were determined. Compared with healthy Chinese participants, 20 patients were diagnosed with small fibre neuropathy. Intraepidermal nerve fibre density was moderately and highly correlated with the small fibre neuropathy-symptom inventory questionnaire and small fibre neuropathy screening list, respectively. The diagnostic values were moderate and high for the small fibre neuropathy-symptom inventory questionnaire (cut-off value = 5, sensitivity = 80%, specificity = 81.8%) and small fibre neuropathy screening list (cut-off value = 8, sensitivity = 94.1%, specificity = 90.9%), respectively. There were no significant differences in the visual analogue scale between the small fibre neuropathy group, mixed small and large fibre neuropathy group, pure large fibre neuropathy group and the normal group. Small fibre neuropathy-symptom inventory questionnaire and small fibre neuropathy screening list represent potential small fibre neuropathy screening tools. Abbreviations EMG electromyography ENA anti-extractable nuclear antigens ESR erythrocyte sedimentation rate IENFD intraepidermal nerve fibre density IGT impaired glucose tolerance NCS nerve conduction studies NDS neuropathy disability score OGTT oral glucose tolerance test PGP protein gene product PN peripheral neuropathy ROC receiver operating characteristic curve ROC-AUC area under the ROC curve SFN small fibre neuropathy SFN-SIQ small-fibre neuropathy and symptom inventory questionnaire SFNSL small fibre neuropathy screening list VAS visual analogue scale WHO World Health Organization.

Tools for Early Prediction of Drug Loading in Lipid-Based Formulations

PubMed Central

2015-01-01

Identification of the usefulness of lipid-based formulations (LBFs) for delivery of poorly water-soluble drugs is at date mainly experimentally based. In this work we used a diverse drug data set, and more than 2,000 solubility measurements to develop experimental and computational tools to predict the loading capacity of LBFs. Computational models were developed to enable in silico prediction of solubility, and hence drug loading capacity, in the LBFs. Drug solubility in mixed mono-, di-, triglycerides (Maisine 35-1 and Capmul MCM EP) correlated (R2 0.89) as well as the drug solubility in Carbitol and other ethoxylated excipients (PEG400, R2 0.85; Polysorbate 80, R2 0.90; Cremophor EL, R2 0.93). A melting point below 150 °C was observed to result in a reasonable solubility in the glycerides. The loading capacity in LBFs was accurately calculated from solubility data in single excipients (R2 0.91). In silico models, without the demand of experimentally determined solubility, also gave good predictions of the loading capacity in these complex formulations (R2 0.79). The framework established here gives a better understanding of drug solubility in single excipients and of LBF loading capacity. The large data set studied revealed that experimental screening efforts can be rationalized by solubility measurements in key excipients or from solid state information. For the first time it was shown that loading capacity in complex formulations can be accurately predicted using molecular information extracted from calculated descriptors and thermal properties of the crystalline drug. PMID:26568134

Tools for Early Prediction of Drug Loading in Lipid-Based Formulations.

PubMed

Alskär, Linda C; Porter, Christopher J H; Bergström, Christel A S

2016-01-04

Identification of the usefulness of lipid-based formulations (LBFs) for delivery of poorly water-soluble drugs is at date mainly experimentally based. In this work we used a diverse drug data set, and more than 2,000 solubility measurements to develop experimental and computational tools to predict the loading capacity of LBFs. Computational models were developed to enable in silico prediction of solubility, and hence drug loading capacity, in the LBFs. Drug solubility in mixed mono-, di-, triglycerides (Maisine 35-1 and Capmul MCM EP) correlated (R(2) 0.89) as well as the drug solubility in Carbitol and other ethoxylated excipients (PEG400, R(2) 0.85; Polysorbate 80, R(2) 0.90; Cremophor EL, R(2) 0.93). A melting point below 150 °C was observed to result in a reasonable solubility in the glycerides. The loading capacity in LBFs was accurately calculated from solubility data in single excipients (R(2) 0.91). In silico models, without the demand of experimentally determined solubility, also gave good predictions of the loading capacity in these complex formulations (R(2) 0.79). The framework established here gives a better understanding of drug solubility in single excipients and of LBF loading capacity. The large data set studied revealed that experimental screening efforts can be rationalized by solubility measurements in key excipients or from solid state information. For the first time it was shown that loading capacity in complex formulations can be accurately predicted using molecular information extracted from calculated descriptors and thermal properties of the crystalline drug.

Small-area variation in screening for cancer, glucose and cholesterol in Ontario: a cross-sectional study.

PubMed

Fernandes, Kimberly A; Sutradhar, Rinku; Borkhoff, Cornelia M; Baxter, Nancy; Lofters, Aisha; Rabeneck, Linda; Tinmouth, Jill; Paszat, Lawrence

2015-01-01

Screening for cervical, breast and colon cancers, and elevations of cholesterol and glucose, reduces premature cause-specific mortality from these cancers and circulatory diseases. Despite primary care reforms and incentives, and promotion of cancer-screening programs among individuals, participation is suboptimal. We aimed to examine participation as of Dec. 31, 2011, by factors of deprivation, demographics and primary care at the small-area level. From health care administrative databases, we identified people eligible for each screening test, and their participation, in each dissemination area (referred to as small areas, n = 18 950) in Ontario. We calculated rates for each test among small areas (overall and stratified by demographic, socioeconomic and primary care descriptors) and stratified by sex for all tests combined. We loaded all data into a geographic information system. Funnel plots were generated showing the percentage of eligible people who completed screening for all tests by small area, stratified by sex. Overall and stratified screening prevalence ratios were calculated among small areas. Among small areas, the mean and SD for participation in all tests combined was 31.6% (SD 11.0%) for women and 41.2% (SD 12.0%) for men. Screening prevalence among small areas, for each test and for all tests combined, overall and stratified by sex, declined with decreasing percentage with high school completion, decreasing socioeconomic quintile, and decreasing percentage with an identifiable primary care physician. Our results show that the rate of participation in all eligible screening tests among small areas is much lower than the rate of participation in any one particular test. This finding has implications for the design and implementation of strategies to improve rates of screening.

Mesoporous materials and nanocrystals for enhancing the dissolution behavior of poorly water-soluble drugs.

PubMed

Santos, Helder A; Peltonen, Leena; Limnell, Tarja; Hirvonen, Jouni

2013-01-01

Advanced drug delivery formulations are presently recognized as promising tools for overcoming the adverse physicochemical properties of conventional drug molecules, such as poor water solubility, which often leads to poor drug bioavailability. Oral drug delivery is considered as the easiest and most convenient route of drug administration. However, via the current trends utilizing combinatorial chemistry and high throughput screening in drug development, new drug molecules are moving towards lipophilic and poorly water-soluble large molecules, and the oral delivery route is becoming increasingly challenging. In this context, formulation of poorly soluble and/or permeable drugs using mesoporous materials and nanocrystals technology have proven to be highly successful due to the greater surface/volume ratio of these systems, resulting in improvements in dissolution and bioavailability, as well as enhanced drug permeability. This review addresses the issues of poorly water-soluble drugs with a major focus on recent developments in the application of the mesoporous materials (e.g., porous silicon and silica) and nanocrystals in drug delivery applications. In addition, we present several recent examples of the significant potential of these materials for the pharmaceutical field.

Aqueous solubility calculation for petroleum mixtures in soil using comprehensive two-dimensional gas chromatography analysis data.

PubMed

Mao, Debin; Lookman, Richard; Van De Weghe, Hendrik; Vanermen, Guido; De Brucker, Nicole; Diels, Ludo

2009-04-03

An assessment of aqueous solubility (leaching potential) of soil contaminations with petroleum hydrocarbons (TPH) is important in the context of the evaluation of (migration) risks and soil/groundwater remediation. Field measurements using monitoring wells often overestimate real TPH concentrations in case of presence of pure oil in the screened interval of the well. This paper presents a method to calculate TPH equilibrium concentrations in groundwater using soil analysis by high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography (HPLC-GCXGC). The oil in the soil sample is divided into 79 defined hydrocarbon fractions on two GCXGC color plots. To each of these fractions a representative water solubility is assigned. Overall equilibrium water solubility of the non-aqueous phase liquid (NAPL) present in the sample and the water phase's chemical composition (in terms of the 79 fractions defined) are then calculated using Raoult's law. The calculation method was validated using soil spiked with 13 different TPH mixtures and 1 field-contaminated soil. Measured water solubilities using a column recirculation equilibration experiment agreed well to calculated equilibrium concentrations and water phase TPH composition.

High-throughput Cloning and Expression of Integral Membrane Proteins in Escherichia coli

PubMed Central

Bruni, Renato

2014-01-01

Recently, several structural genomics centers have been established and a remarkable number of three-dimensional structures of soluble proteins have been solved. For membrane proteins, the number of structures solved has been significantly trailing those for their soluble counterparts, not least because over-expression and purification of membrane proteins is a much more arduous process. By using high throughput technologies, a large number of membrane protein targets can be screened simultaneously and a greater number of expression and purification conditions can be employed, leading to a higher probability of successfully determining the structure of membrane proteins. This unit describes the cloning, expression and screening of membrane proteins using high throughput methodologies developed in our laboratory. Basic Protocol 1 deals with the cloning of inserts into expression vectors by ligation-independent cloning. Basic Protocol 2 describes the expression and purification of the target proteins on a miniscale. Lastly, for the targets that express at the miniscale, basic protocols 3 and 4 outline the methods employed for the expression and purification of targets at the midi-scale, as well as a procedure for detergent screening and identification of detergent(s) in which the target protein is stable. PMID:24510647

Fragment Screening of Soluble Epoxide Hydrolase for Lead Generation-Structure-Based Hit Evaluation and Chemistry Exploration.

PubMed

Xue, Yafeng; Olsson, Thomas; Johansson, Carina A; Öster, Linda; Beisel, Hans-Georg; Rohman, Mattias; Karis, David; Bäckström, Stefan

2016-03-04

Soluble epoxide hydrolase (sEH) is involved in the regulation of many biological processes by metabolizing the key bioactive lipid mediator, epoxyeicosatrienoic acids. For the development of sEH inhibitors with improved physicochemical properties, we performed both a fragment screening and a high-throughput screening aiming at an integrated hit evaluation and lead generation. Followed by a joint dose-response analysis to confirm the hits, the identified actives were then effectively triaged by a structure-based hit-classification approach to three prioritized series. Two distinct scaffolds were identified as tractable starting points for potential lead chemistry work. The oxoindoline series bind at the right-hand side of the active-site pocket with hydrogen bonds to the protein. The 2-phenylbenzimidazole-4-sulfonamide series bind at the central channel with significant induced fit, which has not been previously reported. On the basis of the encouraging initial results, we envision that a new lead series with improved properties could be generated if a vector is found that could merge the cyclohexyl functionality of the oxoindoline series with the trifluoromethyl moiety of the 2-phenylbenzimidazole-4-sulfonamide series. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces

NASA Technical Reports Server (NTRS)

Dussinger, Peter M.; Lindemuth, James E.

1997-01-01

The principal objective of this Phase 2 SBIR program was to develop and demonstrate a practically insoluble coating for nickel-based superalloys for Stirling engine heat pipe applications. Specific technical objectives of the program were: (1) Determine the solubility corrosion rates for Nickel 200, Inconel 718, and Udimet 72OLI in a simulated Stirling engine heat pipe environment, (2) Develop coating processes and techniques for capillary groove and screen wick structures, (3) Evaluate the durability and solubility corrosion rates for capillary groove and screen wick structures coated with an insoluble coating in cylindrical heat pipes operating under Stirling engine conditions, and (4) Design and fabricate a coated full-scale, partial segment of the current Stirling engine heat pipe for the Stirling Space Power Convertor program. The work effort successfully demonstrated a two-step nickel aluminide coating process for groove wick structures and interior wall surfaces in contact with liquid metals; demonstrated a one-step nickel aluminide coating process for nickel screen wick structures; and developed and demonstrated a two-step aluminum-to-nickel aluminide coating process for nickel screen wick structures. In addition, the full-scale, partial segment was fabricated and the interior surfaces and wick structures were coated. The heat pipe was charged with sodium, processed, and scheduled to be life tested for up to ten years as a Phase 3 effort.

Cocrystal screening of hydroxybenzamides with benzoic acid derivatives: a comparative study of thermal and solution-based methods.

PubMed

Manin, Alex N; Voronin, Alexander P; Drozd, Ksenia V; Manin, Nikolay G; Bauer-Brandl, Annette; Perlovich, German L

2014-12-18

The main problem occurring at the early stages of cocrystal search is the choice of an effective screening technique. Among the most popular techniques of obtaining cocrystals are crystallization from solution, crystallization from melt and solvent-drop grinding. This paper represents a comparative analysis of the following screening techniques: DSC cocrystal screening method, thermal microscopy and saturation temperature method. The efficiency of different techniques of cocrystal screening was checked in 18 systems. Benzamide and benzoic acid derivatives were chosen as model systems due to their ability to form acid-amide supramolecular heterosynthon. The screening has confirmed the formation of 6 new cocrystals. The screening by the saturation temperature method has the highest screen-out rate but the smallest range of application. DSC screening has a satisfactory accuracy and allows screening over a short time. Thermal microscopy is most efficient as an additional technique used to interpret ambiguous DSC screening results. The study also included an analysis of the influence of solvent type and component solubility on cocrystal formation. Copyright © 2014 Elsevier B.V. All rights reserved.

Application To Bilayer System With Water-Soluble Contrast Enhancing Material

NASA Astrophysics Data System (ADS)

Yabuta, Mitsuo; Ito, Naoki; Yamazaki, Hiroyuki; Nakayama, Toshimasa

1987-09-01

We have developed ,a water-soluble contrast enhancing material, TAD-436 ( Tokyo Ohka. Anti-Defocus Material ) which is consisted of a water-soluble diazonium salt as bleaching compounds and a water-soluble anion type polymer as binder polymers. Needless to say that water is used as solvent in TAD; therefore, it can be spincoated directly on a positive photoresist layer of a quinonediazide-novolak resin type without causing intermixing and furtheremore the bilayer can be developed without stripping TAD immediately after exposure. TAD shows a satisfactory bleaching characteristics on g-line, increases r-value of underlying photoresist and reduces the thickness loss of photoresist layer in unexposed area. Application to bilayer system with TAD will raise the resolution of underlying photoresist and when the focus depth is changed it will make the change in the resist profile small. As the result of it, the notches in the resist patterns on steps is reduced, making the difference in the linewidth between the top and the bottom of steps small.

Microemulsion-loaded hydrogel formulation of butenafine hydrochloride for improved topical delivery.

PubMed

Pillai, Anilkumar B; Nair, Jyothilaksmi V; Gupta, Nishant Kumar; Gupta, Swati

2015-09-01

Topical microemulsion systems for the antifungal drug, butenafine hydrochloride (BTF) were designed and developed to overcome the problems associated with the cutaneous delivery due to poor water solubility. The solubility of BTF in oils, surfactants and co-surfactants was evaluated to screen the components of the microemulsion. Isopropyl palmitate was used as the oil phase, aerosol OT as the surfactant and sorbitan monooleate as co-surfactant. The pseudoternary diagrams were constructed to identify the area of microemulsion existence and optimum systems were designed. The systems were assessed for drug-loading efficiency and characterized for pH, robustness to dilution, globule size, drug content and stability. Viscosity analysis, spreadability, drug content assay, ex vivo skin permeation study and antifungal activity assay were performed for the optimized microemulsion-loaded hydrogel. The optimized BTF microemulsion had a small and uniform globule size. The incorporation of microemulsion system into Carbopol 940 gel was found to be better as compared to sodium alginate or hydroxyl propyl methyl cellulose (HPMC K4 M) gel. The developed gel has shown better ex vivo skin permeation and antifungal activity when compared to marketed BTF cream. Thus, the results provide a basis for the successful delivery of BTF from microemulsion-loaded hydrogel formulation, which resulted in improved penetration of drug and antifungal activity in comparison with commercial formulation of BTF.

Protein mobilities and P-selectin storage in Weibel-Palade bodies.

PubMed

Kiskin, Nikolai I; Hellen, Nicola; Babich, Victor; Hewlett, Lindsay; Knipe, Laura; Hannah, Matthew J; Carter, Tom

2010-09-01

Using fluorescence recovery after photobleaching (FRAP) we measured the mobilities of EGFP-tagged soluble secretory proteins in the endoplasmic reticulum (ER) and in individual Weibel-Palade bodies (WPBs) at early (immature) and late (mature) stages in their biogenesis. Membrane proteins (P-selectin, CD63, Rab27a) were also studied in individual WPBs. In the ER, soluble secretory proteins were mobile; however, following insertion into immature WPBs larger molecules (VWF, Proregion, tPA) and P-selectin became immobilised, whereas small proteins (ssEGFP, eotaxin-3) became less mobile. WPB maturation led to further decreases in mobility of small proteins and CD63. Acute alkalinisation of mature WPBs selectively increased the mobilities of small soluble proteins without affecting larger molecules and the membrane proteins. Disruption of the Proregion-VWF paracrystalline core by prolonged incubation with NH(4)Cl rendered P-selectin mobile while VWF remained immobile. FRAP of P-selectin mutants revealed that immobilisation most probably involves steric entrapment of the P-selectin extracellular domain by the Proregion-VWF paracrystal. Significantly, immobilisation contributed to the enrichment of P-selectin in WPBs; a mutation of P-selectin preventing immobilisation led to a failure of enrichment. Together these data shed new light on the transitions that occur for soluble and membrane proteins following their entry and storage into post-Golgi-regulated secretory organelles.

Early Pregnancy Biochemical Predictors of Gestational Diabetes Mellitus.

PubMed

Powe, Camille E

2017-02-01

Universal oral glucose tolerance-based screening is employed to identify pregnant women with gestational diabetes mellitus (GDM), as treatment of this condition decreases the risk of associated complications. A simple and accurate blood test which identifies women at low or high risk for GDM in the first trimester would have the potential to decrease costs and improve outcomes through prevention or treatment. This review summarizes published data on early pregnancy biomarkers which have been tested as predictors of GDM. A large number of first-trimester biochemical predictors of GDM have been reported, mostly in small case-control studies. These include glycemic markers (fasting glucose, post-load glucose, hemoglobin A1C), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha), insulin resistance markers (fasting insulin, sex hormone-binding globulin), adipocyte-derived markers (adiponectin, leptin), placenta-derived markers (follistatin-like-3, placental growth factor, placental exosomes), and others (e.g., glycosylated fibronectin, soluble (pro)renin receptor, alanine aminotransferase, ferritin). A few large studies suggest that first-trimester fasting glucose or hemoglobin A1C may be useful for identifying women who would benefit from early GDM treatment. To translate the findings from observational studies of first-trimester biomarkers for GDM to clinical practice, trials or cost-effectiveness analyses of screening and treatment strategies based on these novel biomarkers are needed.

Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2

PubMed Central

Zazo Seco, Celia; Serrão de Castro, Luciana; van Nierop, Josephine W.; Morín, Matías; Jhangiani, Shalini; Verver, Eva J.J.; Schraders, Margit; Maiwald, Nadine; Wesdorp, Mieke; Venselaar, Hanka; Spruijt, Liesbeth; Oostrik, Jaap; Schoots, Jeroen; van Reeuwijk, Jeroen; Lelieveld, Stefan H.; Huygen, Patrick L.M.; Insenser, María; Admiraal, Ronald J.C.; Pennings, Ronald J.E.; Hoefsloot, Lies H.; Arias-Vásquez, Alejandro; de Ligt, Joep; Yntema, Helger G.; Jansen, Joop H.; Muzny, Donna M.; Huls, Gerwin; van Rossum, Michelle M.; Lupski, James R.; Moreno-Pelayo, Miguel Angel; Kunst, Henricus P.M.; Kremer, Hannie

2015-01-01

Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants. PMID:26522471

Multilayer screen gives cathode ray tube high contrast

NASA Technical Reports Server (NTRS)

Bullinger, H.; Hilborn, E. H.

1970-01-01

Fabrication method for cathode ray tubes uses low-cost siloxane resin formulations. The resins contain sufficient methyl or phenyl groups for solubility in organic solvents. After vaporization and baking, the polymerized material is stable under vacuum and under temperatures required for tube fabrication.

A study of gas solubilities and transport properties in fuel cell electrolytes

NASA Technical Reports Server (NTRS)

Walker, R. D. J.

1972-01-01

An analysis of the rate of heat generation on the dissolution of sparingly soluble gas in electrolytes was made, and it leads to the conclusion that the temperature changes to be expected are much too small to be measured with precision owing to the slowness of the gas dissolution. It appears that more accurate gas solubility measurements are the only real hope of improved precision in heats of solution and other thermodynamic properties.

Enhancement of solubility and bioavailability of ambrisentan by solid dispersion using Daucus carota as a drug carrier: formulation, characterization, in vitro, and in vivo study.

PubMed

Deshmane, Subhash; Deshmane, Snehal; Shelke, Santosh; Biyani, Kailash

2018-06-01

Ambrisentan is an US FDA approved drug, it is the second oral endothelin A receptor antagonist known for the treatment of pulmonary arterial hypertension, but its oral administration is limited due to its poor water solubility. Hence, the objective of the investigation was focused on enhancement of solubility and bioavailability of ambrisentan by solid dispersion technique using natural Daucus carota extract as drug carrier. Drug carrier was evaluated for solubility, swelling index, viscosity, angle of repose, hydration capacity, and acute toxicity test (LD 50 ). Ambrisentan was studied for the saturation solubility, phase solubility, and Gibbs free energy change. Compatibility of drug and the natural carrier was confirmed by DSC, FTIR, and XRD. Solid dispersions were evaluated for drug content, solubility, morphology, in vitro, and in vivo study. Screening of the natural carrier showed the desirable properties like water solubility, less swelling index, less viscosity, and acute toxicity study revealed no any clinical symptoms of toxicity. Drug and carrier interaction study confirmed the compatibility to consider its use in the formulation. Formed particles were found to be spherical with smooth surface. In vitro studies revealed higher drug release from the solid dispersion than that of the physical mixture. Bioavailability study confirms the increased absorption and bioavailability by oral administration of solid dispersion. Hence, it can be concluded that the natural Daucus carota extract can be the better alternative source for the preparation of solid dispersion and/or other dosage forms for improving solubility and bioavailability.

Using MD simulations to calculate how solvents modulate solubility

PubMed Central

Liu, Shuai; Cao, Shannon; Hoang, Kevin; Young, Kayla L.; Paluch, Andrew S.; Mobley, David L.

2016-01-01

Here, our interest is in predicting solubility in general, and we focus particularly on predicting how the solubility of particular solutes is modulated by the solvent environment. Solubility in general is extremely important, both for theoretical reasons – it provides an important probe of the balance between solute-solute and solute-solvent interactions – and for more practical reasons, such as how to control the solubility of a given solute via modulation of its environment, as in process chemistry and separations. Here, we study how the change of solvent affects the solubility of a given compound. That is, we calculate relative solubilities. We use MD simulations to calculate relative solubility and compare our calculated values with experiment as well as with results from several other methods, SMD and UNIFAC, the latter of which is commonly used in chemical engineering design. We find that straightforward solubility calculations based on molecular simulations using a general small-molecule force field outperform SMD and UNIFAC both in terms of accuracy and coverage of the relevant chemical space. PMID:26878198

Enhancement of solubility and dissolution of coenzyme Q10 using solid dispersion formulation.

PubMed

Nepal, Pushp R; Han, Hyo-Kyung; Choi, Hoo-Kyun

2010-01-04

This study aimed to develop a stable solid dispersion of Coenzyme Q(10) (CoQ(10)) with high aqueous solubility and dissolution rate. Among various carriers screened, poloxamer 407 was most effective to form a superior solid dispersion of CoQ(10) having significantly enhanced solubility. Particularly, solid dispersion of CoQ(10) with poloxamer 407 in the weight ratio of 1:5 prepared by melting method enhanced the solubility of CoQ(10) to the greatest extent. However, it exhibited poor stability and hence Aerosil 200 (colloidal silicon dioxide) was incorporated into the solid dispersion as an adsorbent to inhibit the recrystallization process. The solid dispersion of CoQ(10), poloxamer 407 and Aerosil 200 in the weight ratio of 1:5:6 exhibited improved stability with no significant change in solubility during the 1-month stability test. Moreover, the solid dispersion formulation containing Aerosil 200 significantly enhanced the extent of drug release (approx. 75% release) as well as the dissolution rate of CoQ(10). In conclusion, the present study has developed the stable solid dispersion formulation of CoQ(10) with poloxamer 407 and Aerosil 200 for the enhanced solubility and dissolution of CoQ(10), which could also offer some additional advantages including ease of preparation, good flowability and cost-effectiveness.

Small Screen Use and Driving Safety.

PubMed

Atchley, Paul; Strayer, David L

2017-11-01

The increased availability of "small screens," wireless devices with Internet-enabled connections, and their associated applications has almost overnight changed the way that we interact with our phones. The current work outlines some of the aspects of this problem as it relates to the influence of small screens on driving safety. Small screens are highly compelling to drivers, both for the information they convey and because the ability to ignore them while driving is impaired by cognitive resources used by the driving task itself. However, much is unknown about why people make choices to multitask while driving. Given the safety risks, it is recommended that parents, the public, and regulators take a stand against the use of Internet-enabled small screens unrelated to driving when the vehicle is in motion. Copyright © 2017 by the American Academy of Pediatrics.

Screening of the binding of small molecules to proteins by desorption electrospray ionization mass spectrometry combined with protein microarray.

PubMed

Yao, Chenxi; Wang, Tao; Zhang, Buqing; He, Dacheng; Na, Na; Ouyang, Jin

2015-11-01

The interaction between bioactive small molecule ligands and proteins is one of the important research areas in proteomics. Herein, a simple and rapid method is established to screen small ligands that bind to proteins. We designed an agarose slide to immobilize different proteins. The protein microarrays were allowed to interact with different small ligands, and after washing, the microarrays were screened by desorption electrospray ionization mass spectrometry (DESI MS). This method can be applied to screen specific protein binding ligands and was shown for seven proteins and 34 known ligands for these proteins. In addition, a high-throughput screening was achieved, with the analysis requiring approximately 4 s for one sample spot. We then applied this method to determine the binding between the important protein matrix metalloproteinase-9 (MMP-9) and 88 small compounds. The molecular docking results confirmed the MS results, demonstrating that this method is suitable for the rapid and accurate screening of ligands binding to proteins. Graphical Abstract ᅟ.

The Eph-Receptor A7 Is a Soluble Tumor Suppressor for Follicular Lymphoma

PubMed Central

Oricchio, Elisa; Nanjangud, Gourd; Wolfe, Andrew L.; Schatz, Jonathan H.; Mavrakis, Konstantinos J.; Jiang, Man; Liu, Xiaoping; Bruno, Joanne; Heguy, Adriana; Olshen, Adam B.; Socci, Nicholas D.; Teruya-Feldstein, J.; Weis-Garcia, Frances; Tam, Wayne; Shaknovich, Rita; Melnick, Ari; Himanen, Juha P.; Chaganti, R.S.K.; Wendel, Hans-Guido

2011-01-01

Insights into cancer genetics can lead to therapeutic opportunities. By cross-referencing chromosomal changes with an unbiased genetic screen we identify the ephrin receptor A7 (EPHA7) as a tumor suppressor in follicular lymphoma (FL). EPHA7 is a target of 6q deletions and inactivated in 72 % of FLs. Knockdown of EPHA7 drives lymphoma development in a murine FL model. In analogy to its physiological function in brain development, a soluble splice variant of EPHA7 (EPHA7TR) interferes with another Eph-receptor and blocks oncogenic signals in lymphoma cells. Consistent with this drug-like activity, administration of the purified EPHA7TR protein produces anti-tumor effects against xenografted human lymphomas. Further, by fusing EPHA7TR to the anti-CD20 antibody (rituximab) we can directly target this tumor suppressor to lymphomas in vivo. Our study attests to the power of combining descriptive tumor genomics with functional screens and reveals EPHA7TR as tumor suppressor with immediate therapeutic potential. PMID:22036564

The Denaturation Transition of DNA in Mixed Solvents

PubMed Central

Hammouda, Boualem; Worcester, David

2006-01-01

The helix-to-coil denaturation transition in DNA has been investigated in mixed solvents at high concentration using ultraviolet light absorption spectroscopy and small-angle neutron scattering. Two solvents have been used: water and ethylene glycol. The “melting” transition temperature was found to be 94°C for 4% mass fraction DNA/d-water and 38°C for 4% mass fraction DNA/d-ethylene glycol. The DNA melting transition temperature was found to vary linearly with the solvent fraction in the mixed solvents case. Deuterated solvents (d-water and d-ethylene glycol) were used to enhance the small-angle neutron scattering signal and 0.1M NaCl (or 0.0058 g/g mass fraction) salt concentration was added to screen charge interactions in all cases. DNA structural information was obtained by small-angle neutron scattering, including a correlation length characteristic of the inter-distance between the hydrogen-containing (desoxyribose sugar-amine base) groups. This correlation length was found to increase from 8.5 to 12.3 Å across the melting transition. Ethylene glycol and water mixed solvents were found to mix randomly in the solvation region in the helix phase, but nonideal solvent mixing was found in the melted coil phase. In the coil phase, solvent mixtures are more effective solvating agents than either of the individual solvents. Once melted, DNA coils behave like swollen water-soluble synthetic polymer chains. PMID:16815902

The solubility of hydrogen in rhodium, ruthenium, iridium and nickel.

NASA Technical Reports Server (NTRS)

Mclellan, R. B.; Oates, W. A.

1973-01-01

The temperature variation of the solubility of hydrogen in rhodium, ruthenium, iridium, and nickel in equilibrium with H2 gas at 1 atm pressure has been measured by a technique involving saturating the solvent metal with hydrogen, quenching, and analyzing in resultant solid solutions. The solubilities determined are small (atom fraction of H is in the range from 0.0005 to 0.00001, and the results are consistent with the simple quasi-regular model for dilute interstitial solid solutions. The relative partial enthalpy and excess entropy of the dissolved hydrogen atoms have been calculated from the solubility data and compared with well-known correlations between these quantities.

Soluble Dietary Fibers Can Protect the Small Intestinal Mucosa Without Affecting the Anti-inflammatory Effect of Indomethacin in Adjuvant-Induced Arthritis Rats.

PubMed

Satoh, Hiroshi; Matsumoto, Hiroki; Hirakawa, Tomoe; Wada, Naoki

2016-01-01

How to prevent the small intestinal damage induced by NSAIDs is an urgent issue to be resolved. In the present study, we examined the effects of soluble dietary fibers on both anti-inflammatory and ulcerogenic effects of indomethacin in arthritic rats. Male Wistar rats weighing 180-220 g were used. Arthritis was induced by injecting Freund's complete adjuvant (killed M. tuberculosis) into the plantar region of the right hindpaw. The animals were fed a regular powder diet for rats or a diet supplemented with soluble dietary fibers such as pectin or guar gum. Indomethacin was administered once a day for 3 days starting 14 days after the adjuvant injection, when marked arthritis was observed. The volumes of the hindpaw were measured before and after indomethacin treatment to evaluate the effect of indomethacin on edema. The lesions in the small intestine were examined 24 h after the final dosing of indomethacin. Hindpaw volume was increased about 3 times 14 days after injection of the adjuvant. Indomethacin (3-10 mg/kg, p.o.) decreased hindpaw volume dose-dependently, but caused severe lesions in the small intestine at doses of 6 and 10 mg/kg. The addition of pectin (1-10 %) or guar gum (10 %) to the diet markedly decreased the lesion formation without affecting the anti-edema action of indomethacin. The same effects of pectin were observed when indomethacin was administered subcutaneously. It is suggested that soluble dietary fibers can prevent intestinal damage induced by NSAIDs without affecting the anti-inflammatory effect of these agents.

An expression vector tailored for large-scale, high-throughput purification of recombinant proteins ☆

PubMed Central

Donnelly, Mark I.; Zhou, Min; Millard, Cynthia Sanville; Clancy, Shonda; Stols, Lucy; Eschenfeldt, William H.; Collart, Frank R.; Joachimiak, Andrzej

2009-01-01

Production of milligram quantities of numerous proteins for structural and functional studies requires an efficient purification pipeline. We found that the dual tag, his6-tag–maltose-binding protein (MBP), intended to facilitate purification and enhance proteins’ solubility, disrupted such a pipeline, requiring additional screening and purification steps. Not all proteins rendered soluble by fusion to MBP remained soluble after its proteolytic removal, and in those cases where the protein remained soluble, standard purification protocols failed to remove completely the stoichiometric amount of his6-tagged MBP generated by proteolysis. Both liabilities were alleviated by construction of a vector that produces fusion proteins in which MBP, the his6-tag and the target protein are separated by highly specific protease cleavage sites in the configuration MBP-site-his6-site-protein. In vivo cleavage at the first site by co-expressed protease generated untagged MBP and his6-tagged target protein. Proteins not truly rendered soluble by transient association with MBP precipitated, and untagged MBP was easily separated from the his-tagged target protein by conventional protocols. The second protease cleavage site allowed removal of the his6-tag. PMID:16497515

Nanobody based immunoassay for human soluble epoxide hydrolase detection using polyHRP for signal enhancement—the rediscovery of polyHRP

USDA-ARS?s Scientific Manuscript database

Soluble epoxide hydrolase (sEH) is a potential pharmacological target for treating hypertension, vascular inflammation, cancer, pain and multiple cardiovascular related diseases. A variable domain of a heavy chain only antibody (termed sdAb, nanobody or VHH) possesses advantages of small size, high ...

Nanoliter-Scale Protein Crystallization and Screening with a Microfluidic Droplet Robot

PubMed Central

Zhu, Ying; Zhu, Li-Na; Guo, Rui; Cui, Heng-Jun; Ye, Sheng; Fang, Qun

2014-01-01

Large-scale screening of hundreds or even thousands of crystallization conditions while with low sample consumption is in urgent need, in current structural biology research. Here we describe a fully-automated droplet robot for nanoliter-scale crystallization screening that combines the advantages of both automated robotics technique for protein crystallization screening and the droplet-based microfluidic technique. A semi-contact dispensing method was developed to achieve flexible, programmable and reliable liquid-handling operations for nanoliter-scale protein crystallization experiments. We applied the droplet robot in large-scale screening of crystallization conditions of five soluble proteins and one membrane protein with 35–96 different crystallization conditions, study of volume effects on protein crystallization, and determination of phase diagrams of two proteins. The volume for each droplet reactor is only ca. 4–8 nL. The protein consumption significantly reduces 50–500 fold compared with current crystallization stations. PMID:24854085

Nanoliter-scale protein crystallization and screening with a microfluidic droplet robot.

PubMed

Zhu, Ying; Zhu, Li-Na; Guo, Rui; Cui, Heng-Jun; Ye, Sheng; Fang, Qun

2014-05-23

Large-scale screening of hundreds or even thousands of crystallization conditions while with low sample consumption is in urgent need, in current structural biology research. Here we describe a fully-automated droplet robot for nanoliter-scale crystallization screening that combines the advantages of both automated robotics technique for protein crystallization screening and the droplet-based microfluidic technique. A semi-contact dispensing method was developed to achieve flexible, programmable and reliable liquid-handling operations for nanoliter-scale protein crystallization experiments. We applied the droplet robot in large-scale screening of crystallization conditions of five soluble proteins and one membrane protein with 35-96 different crystallization conditions, study of volume effects on protein crystallization, and determination of phase diagrams of two proteins. The volume for each droplet reactor is only ca. 4-8 nL. The protein consumption significantly reduces 50-500 fold compared with current crystallization stations.

Identification of N-ethylmethylamine as a novel scaffold for inhibitors of soluble epoxide hydrolase by crystallographic fragment screening.

PubMed

Amano, Yasushi; Tanabe, Eiki; Yamaguchi, Tomohiko

2015-05-15

Soluble epoxide hydrolase (sEH) is a potential target for the treatment of inflammation and hypertension. X-ray crystallographic fragment screening was used to identify fragment hits and their binding modes. Eight fragment hits were identified via soaking of sEH crystals with fragment cocktails, and the co-crystal structures of these hits were determined via individual soaking. Based on the binding mode, N-ethylmethylamine was identified as a promising scaffold that forms hydrogen bonds with the catalytic residues of sEH, Asp335, Tyr383, and Tyr466. Compounds containing this scaffold were selected from an in-house chemical library and assayed. Although the starting fragment had a weak inhibitory activity (IC50: 800μM), we identified potent inhibitors including 2-({[2-(adamantan-1-yl)ethyl]amino}methyl)phenol exhibiting the highest inhibitory activity (IC50: 0.51μM). This corresponded to a more than 1500-fold increase in inhibitory activity compared to the starting fragment. Co-crystal structures of the hit compounds demonstrate that the binding of N-ethylmethylamine to catalytic residues is similar to that of the starting fragment. We therefore consider crystallographic fragment screening to be appropriate for the identification of weak but promising fragment hits. Copyright © 2015 Elsevier Ltd. All rights reserved.

A miniature cell for gas solubility measurements in oils and bitumen.

PubMed

Foroughi, Hooman; Acosta, Edgar J; Kawaji, Masahiro

2011-03-01

A miniature cell has been designed and constructed to measure gas solubility in crude oils and bitumen. The cell was made of stainless steel with a total internal volume of 1.835 cc and only an oil sample of 0.4 cc was required for one set of measurements at different pressures. By using this small cell, the waiting time for reaching equilibrium was less than 10 min. The technique was validated by measuring CO(2) gas solubility in two bitumen samples. The results were compared and found to be in very good agreement with available data. The apparatus was also used to study the effect of ashphaltene on CO(2) solubility in bitumen. It was shown that ashphaltene had a negligible effect on CO(2) solubility in bitumen.

Water solubility in aluminous orthopyroxene and the origin of Earth's asthenosphere.

PubMed

Mierdel, Katrin; Keppler, Hans; Smyth, Joseph R; Langenhorst, Falko

2007-01-19

Plate tectonics is based on the concept of rigid lithosphere plates sliding on a mechanically weak asthenosphere. Many models assume that the weakness of the asthenosphere is related to the presence of small amounts of hydrous melts. However, the mechanism that may cause melting in the asthenosphere is not well understood. We show that the asthenosphere coincides with a zone where the water solubility in mantle minerals has a pronounced minimum. The minimum is due to a sharp decrease of water solubility in aluminous orthopyroxene with depth, whereas the water solubility in olivine continuously increases with pressure. Melting in the asthenosphere may therefore be related not to volatile enrichment but to a minimum in water solubility, which causes excess water to form a hydrous silicate melt.

How big is the influence of biogenic silicon pools on short-term changes in water-soluble silicon in soils? Implications from a study of a 10-year-old soil-plant system

NASA Astrophysics Data System (ADS)

Puppe, Daniel; Höhn, Axel; Kaczorek, Danuta; Wanner, Manfred; Wehrhan, Marc; Sommer, Michael

2017-11-01

The significance of biogenic silicon (BSi) pools as a key factor for the control of Si fluxes from terrestrial to aquatic ecosystems has been recognized for decades. However, while most research has been focused on phytogenic Si pools, knowledge of other BSi pools is still limited. We hypothesized that different BSi pools influence short-term changes in the water-soluble Si fraction in soils to different extents. To test our hypothesis we took plant (Calamagrostis epigejos, Phragmites australis) and soil samples in an artificial catchment in a post-mining landscape in the state of Brandenburg, Germany. We quantified phytogenic (phytoliths), protistic (diatom frustules and testate amoeba shells) and zoogenic (sponge spicules) Si pools as well as Tiron-extractable and water-soluble Si fractions in soils at the beginning (t0) and after 10 years (t10) of ecosystem development. As expected the results of Tiron extraction showed that there are no consistent changes in the amorphous Si pool at Chicken Creek (Hühnerwasser) as early as after 10 years. In contrast to t0 we found increased water-soluble Si and BSi pools at t10; thus we concluded that BSi pools are the main driver of short-term changes in water-soluble Si. However, because total BSi represents only small proportions of water-soluble Si at t0 (< 2 %) and t10 (2.8-4.3 %) we further concluded that smaller (< 5 µm) and/or fragile phytogenic Si structures have the biggest impact on short-term changes in water-soluble Si. In this context, extracted phytoliths (> 5 µm) only amounted to about 16 % of total Si contents of plant materials of C. epigejos and P. australis at t10; thus about 84 % of small-scale and/or fragile phytogenic Si is not quantified by the used phytolith extraction method. Analyses of small-scale and fragile phytogenic Si structures are urgently needed in future work as they seem to represent the biggest and most reactive Si pool in soils. Thus they are the most important drivers of Si cycling in terrestrial biogeosystems.

Influence of feed intake, forage physical form, and forage fiber content on particle size of masticated forage, ruminal digesta, and feces of dairy cows.

PubMed

Shaver, R D; Nytes, A J; Satter, L D; Jorgensen, N A

1988-06-01

Two trials were conducted to determine particle size of masticates, ruminal digesta, and feces of dairy cows. In Trial 1, three Holstein cows with ruminal cannulae were fed prebloom alfalfa hay in long, chopped, or pelleted form in a Latin square design (21-d periods) conducted in early lactation (wk 3 to 11) and again during the dry period to attain high (3.75) and low (1.95% of BW) feed consumption. In trial 2, prebloom, midbloom, and full bloom alfalfa hay, mature bromegrass hay, and corn silage were fed to early lactation (wk 5 to 15) Holsteins in a 5 X 5 Latin square design (15-d periods). All diets (Trials 1 and 2) were formulated to 17% CP and contained forage:grain in a 60:40 ratio (DM basis). Similar particle distributions of digesta from long and chopped hay diets suggest little influence of chopping forage on particle size reduction when high quality forage is fed. The large proportion of DM in the small particle (less than .6 mm) pool in the rumen in both trials suggests that rate of escape of small particles from the rumen is an important factor influencing ruminal retention time. Increased proportion of coarse (greater than or equal to 2.36-mm screen) fecal particles at high intake and with fine grinding appears related to a reduction in chewing per unit feed consumed. Soluble DM and particulate matter passing a .063-mm screen made up a significant portion (30 to 50%) of the total DM sieved from all sampling sites in both trials.

Small Screen Technology Use among Indigenous Boarding School Adolescents from Remote Regions of Western Australia

ERIC Educational Resources Information Center

Johnson, Genevieve Marie; Oliver, Rhonda

2014-01-01

The uptake of small screen technology by adolescents is widespread, particularly in industrial nations. Whether the same is true for Australian Aboriginal youth is less clear as there is a dearth of research in this regard. Therefore, in this exploratory study the use of small screen technology by Indigenous students was examined. Twenty-four…

Detecting ordered small molecule drug aggregates in live macrophages: a multi-parameter microscope image data acquisition and analysis strategy

PubMed Central

Rzeczycki, Phillip; Yoon, Gi Sang; Keswani, Rahul K.; Sud, Sudha; Stringer, Kathleen A.; Rosania, Gus R.

2017-01-01

Following prolonged administration, certain orally bioavailable but poorly soluble small molecule drugs are prone to precipitate out and form crystal-like drug inclusions (CLDIs) within the cells of living organisms. In this research, we present a quantitative multi-parameter imaging platform for measuring the fluorescence and polarization diattenuation signals of cells harboring intracellular CLDIs. To validate the imaging system, the FDA-approved drug clofazimine (CFZ) was used as a model compound. Our results demonstrated that a quantitative multi-parameter microscopy image analysis platform can be used to study drug sequestering macrophages, and to detect the formation of ordered molecular aggregates formed by poorly soluble small molecule drugs in animals. PMID:28270989

Detecting ordered small molecule drug aggregates in live macrophages: a multi-parameter microscope image data acquisition and analysis strategy.

PubMed

Rzeczycki, Phillip; Yoon, Gi Sang; Keswani, Rahul K; Sud, Sudha; Stringer, Kathleen A; Rosania, Gus R

2017-02-01

Following prolonged administration, certain orally bioavailable but poorly soluble small molecule drugs are prone to precipitate out and form crystal-like drug inclusions (CLDIs) within the cells of living organisms. In this research, we present a quantitative multi-parameter imaging platform for measuring the fluorescence and polarization diattenuation signals of cells harboring intracellular CLDIs. To validate the imaging system, the FDA-approved drug clofazimine (CFZ) was used as a model compound. Our results demonstrated that a quantitative multi-parameter microscopy image analysis platform can be used to study drug sequestering macrophages, and to detect the formation of ordered molecular aggregates formed by poorly soluble small molecule drugs in animals.

Design and in vitro activities of N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, novel small molecule Hypoxia Inducible Factor-1 (HIF-1) pathway inhibitors and anti-cancer agents

PubMed Central

Mun, Jiyoung; Jabbar, Adnan Abdul; Devi, Narra Sarojini; Yin, Shaoman; Wang, Yingzhe; Tan, Chalet; Culver, Deborah; Snyder, James P.; Van Meir, Erwin G.; Goodman, Mark M.

2013-01-01

The Hypoxia Inducible Factor (HIF) pathway is an attractive target for cancer as it controls tumor adaptation to growth under hypoxia and mediates chemo- and radiation resistance. We previously discovered 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide, as a novel small molecule HIF-1 pathway inhibitor in a high-throughput cell-based assay, but its in vivo delivery is hampered by poor aqueous solubility (0.009 μM in water; logP7.4: 3.7). Here we describe the synthesis of twelve N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, which were designed to possess optimal lipophilicities and aqueous solubilities by in silico calculations. Experimental logP7.4 values of 8 of the 12 new analogs ranged from 1.2 ∼ 3.1. Aqueous solubilities of 3 analogs were measured, among which the most soluble N-[(8-methoxy-2,2-dimethyl-2H-chromen-6-yl)methyl]-N-(propan-2-yl)pyridine-2-sulfonamide had an aqueous solubility of 80 μM, e.g. a solubility improvement of ∼9,000-fold. The pharmacological optimization had minimal impact on drug efficacy as the compounds retained IC50 values at or below 5 μM in our HIF-dependent reporter assay. PMID:22746274

The transcriptional response of Escherichia coli to recombinant protein insolubility.

PubMed

Smith, Harold E

2007-03-01

Bacterial production of recombinant proteins offers several advantages over alternative expression methods and remains the system of choice for many structural genomics projects. However, a large percentage of targets accumulate as insoluble inclusion bodies rather than soluble protein, creating a significant bottleneck in the protein production pipeline. Numerous strategies have been reported that can improve in vivo protein solubility, but most do not scale easily for high-throughput expression screening. To understand better the host cell response to the accumulation of insoluble protein, we determined genome-wide changes in bacterial gene expression upon induction of either soluble or insoluble target proteins. By comparing transcriptional profiles for multiple examples from the soluble or insoluble class, we identified a pattern of gene expression that correlates strongly with protein solubility. Direct targets of the sigma32 heat shock sigma factor, which includes genes involved in protein folding and degradation, were highly expressed in response to induction of insoluble protein. This same group of genes was also upregulated by insoluble protein accumulation under a different growth regime, indicating that sigma32-mediated gene expression is a general response to protein insolubility. This knowledge provides a starting point for the rational design of growth parameters and host strains with improved protein solubility characteristics. Summary Problems with protein solubility are frequently encountered when recombinant proteins are expressed in E. coli. The bacterial host responds to this problem by increasing expression of the protein folding machinery via the heat shock sigma factor sigma32. Manipulation of the sigma32 regulon might provide a general mechanism for improving recombinant protein solubility.

Solubility limits in quaternary SnTe-based alloys [Metastability and solubility limits in quaternary SnTe-based alloys guided by combinatorial sputtering

DOE PAGES

Siol, Sebastian; Holder, Aaron; Ortiz, Brenden R.; ...

2017-05-09

Here, the controlled decomposition of metastable alloys is an attractive route to form nanostructured thermoelectric materials with reduced thermal conductivity. The ternary SnTe–MnTe and SnTe–SnSe heterostructural alloys have been demonstrated as promising materials for thermoelectric applications. In this work, the quaternary Sn 1–yMnyTe 1–xSe x phase space serves as a relevant model system to explore how a combination of computational and combinatorial-growth methods can be used to study equilibrium and non-equilibrium solubility limits. Results from first principle calculations indicate low equilibrium solubility for x,y < 0.05 that are in good agreement with results obtained from bulk equilibrium synthesis experiments andmore » predict significantly higher spinodal limits. An experimental screening using sputtered combinatorial thin film sample libraries showed a remarkable increase in non-equilibrium solubility for x,y > 0.2. These theoretical and experimental results were used to guide the bulk synthesis of metastable alloys. The ability to reproduce the non-equilibrium solubility levels in bulk materials indicates that such theoretical calculations and combinatorial growth can inform bulk synthetic routes. Further, the large difference between equilibrium and non-equilibrium solubility limits in Sn 1–yMn yTe 1–xSe x indicates these metastable alloys are attractive in terms of nano-precipitate formation for potential thermoelectric applications.« less

Solubility of lysozyme in polyethylene glycol-electrolyte mixtures: the depletion interaction and ion-specific effects.

PubMed

Boncina, Matjaz; Rescic, Jurij; Vlachy, Vojko

2008-08-01

The solubility of aqueous solutions of lysozyme in the presence of polyethylene glycol and various alkaline salts was studied experimentally. The protein-electrolyte mixture was titrated with polyethylene glycol, and when precipitation of the protein occurred, a strong increase of the absorbance at 340 nm was observed. The solubility data were obtained as a function of experimental variables such as protein and electrolyte concentrations, electrolyte type, degree of polymerization of polyethylene glycol, and pH of the solution; the last defines the net charge of the lysozyme. The results indicate that the solubility of lysozyme decreases with the addition of polyethylene glycol; the solubility is lower for a polyethylene glycol with a higher degree of polymerization. Further, the logarithm of the protein solubility is a linear function of the polyethylene glycol concentration. The process is reversible and the protein remains in its native form. An increase of the electrolyte (NaCl) concentration decreases the solubility of lysozyme in the presence and absence of polyethylene glycol. The effect can be explained by the screening of the charged amino residues of the protein. The solubility experiments were performed at two different pH values (pH = 4.0 and 6.0), where the lysozyme net charge was +11 and +8, respectively. Ion-specific effects were systematically investigated. Anions such as Br(-), Cl(-), F(-), and H(2)PO(4)(-) (all in combination with Na(+)), when acting as counterions to a protein with positive net charge, exhibit a strong effect on the lysozyme solubility. The differences in protein solubility for chloride solutions with different cations Cs(+), K(+), and Na(+) (coions) were much smaller. The results at pH = 4.0 show that anions decrease the lysozyme solubility in the order F(-) < H(2)PO(4)(-) < Cl(-) < Br(-) (the inverse Hofmeister series), whereas cations follow the direct Hofmeister series (Cs(+) < K(+) < Na(+)) in this situation.

A new small molecule inhibitor of soluble guanylate cyclase

PubMed Central

Mota, Filipa; Gane, Paul; Hampden-Smith, Kathryn; Allerston, Charles K.; Garthwaite, John; Selwood, David L.

2015-01-01

Soluble guanylate cyclase (sGC) is a haem containing enzyme that regulates cardiovascular homeostasis and multiple mechanisms in the central and peripheral nervous system. Commonly used inhibitors of sGC activity act through oxidation of the haem moiety, however they also bind haemoglobin and this limits their bioavailability for in vivo studies. We have discovered a new class of small molecule inhibitors of sGC and have characterised a compound designated D12 (compound 10) which binds to the catalytic domain of the enzyme with a KD of 11 μM in a SPR assay. PMID:26264842

Selecting, Acquiring, and Using Small Molecule Libraries for High-Throughput Screening

PubMed Central

Dandapani, Sivaraman; Rosse, Gerard; Southall, Noel; Salvino, Joseph M.; Thomas, Craig J.

2015-01-01

The selection, acquisition and use of high quality small molecule libraries for screening is an essential aspect of drug discovery and chemical biology programs. Screening libraries continue to evolve as researchers gain a greater appreciation of the suitability of small molecules for specific biological targets, processes and environments. The decisions surrounding the make-up of any given small molecule library is informed by a multitude of variables and opinions vary on best-practices. The fitness of any collection relies upon upfront filtering to avoiding problematic compounds, assess appropriate physicochemical properties, install the ideal level of structural uniqueness and determine the desired extent of molecular complexity. These criteria are under constant evaluation and revision as academic and industrial organizations seek out collections that yield ever improving results from their screening portfolios. Practical questions including cost, compound management, screening sophistication and assay objective also play a significant role in the choice of library composition. This overview attempts to offer advice to all organizations engaged in small molecule screening based upon current best practices and theoretical considerations in library selection and acquisition. PMID:26705509

Selecting, Acquiring, and Using Small Molecule Libraries for High-Throughput Screening.

PubMed

Dandapani, Sivaraman; Rosse, Gerard; Southall, Noel; Salvino, Joseph M; Thomas, Craig J

The selection, acquisition and use of high quality small molecule libraries for screening is an essential aspect of drug discovery and chemical biology programs. Screening libraries continue to evolve as researchers gain a greater appreciation of the suitability of small molecules for specific biological targets, processes and environments. The decisions surrounding the make-up of any given small molecule library is informed by a multitude of variables and opinions vary on best-practices. The fitness of any collection relies upon upfront filtering to avoiding problematic compounds, assess appropriate physicochemical properties, install the ideal level of structural uniqueness and determine the desired extent of molecular complexity. These criteria are under constant evaluation and revision as academic and industrial organizations seek out collections that yield ever improving results from their screening portfolios. Practical questions including cost, compound management, screening sophistication and assay objective also play a significant role in the choice of library composition. This overview attempts to offer advice to all organizations engaged in small molecule screening based upon current best practices and theoretical considerations in library selection and acquisition.

Notch as a Diagnostic Marker and Therapeutic Target in Human Breast Cancer

DTIC Science & Technology

2008-05-01

JAG1. The soluble JAG1-ECD-FLAG was expressed in Chinese Hamster ovary K1 (CHO-K1) cells and then CHO clones were screened for their ability to... medium was collected from CHO-K1- hJAG1-ECD-Flag (clone14) grown in culture. The purification strategy to obtain hJAG1-ECD-Flag is as follows: 1) pre...expressed in Chinese hampster ovary K1 (CHO-K1) cells and then CHO clones were screened for their ability to express high levels of secreted JAG1-Flag

An Automated Heart Rate Detection Platform in Wild-Type Zebrafish for Cardiotoxicity Screening of Fine Particulate Matter Air Pollution

EPA Science Inventory

Exposure to air pollution-derived particulate matter (PM) causes adverse cardiovascular health outcomes, with increasing evidence implicating soluble components of PM; however, the enormous number of unique PM samples from different air sheds far exceeds the capacity of conventio...

A SCREENING MODEL FOR SIMULATING DNAPL FLOW AND TRANSPORT IN POROUS MEDIA: THEORETICAL DEVELOPMENT

EPA Science Inventory

There exists a need for a simple tool that will allow us to analyze a DNAPL contamination scenario from free-product release to transport of soluble constituents to downgradient receptor wells. The objective of this manuscript is to present the conceptual model and formulate the ...

In Situ Target Engagement Studies in Adherent Cells.

PubMed

Axelsson, Hanna; Almqvist, Helena; Otrocka, Magdalena; Vallin, Michaela; Lundqvist, Sara; Hansson, Pia; Karlsson, Ulla; Lundbäck, Thomas; Seashore-Ludlow, Brinton

2018-04-20

A prerequisite for successful drugs is effective binding of the desired target protein in the complex environment of a living system. Drug-target engagement has typically been difficult to monitor in physiologically relevant models, and with current methods, especially, while maintaining spatial information. One recent technique for quantifying drug-target engagement is the cellular thermal shift assay (CETSA), in which ligand-induced protein stabilization is measured after a heat challenge. Here, we describe a CETSA protocol in live A431 cells for p38α (MAPK14), where remaining soluble protein is detected in situ, using high-content imaging in 384-well, microtiter plates. We validate this assay concept using a number of known p38α inhibitors and further demonstrate the potential of this technology for chemical probe and drug discovery purposes by performing a small pilot screen for novel p38α binders. Importantly, this protocol creates a workflow that is amenable to adherent cells in their native state and yields spatially resolved target engagement information measurable at the single-cell level.

Cisplatin Analogs Confer Protection against Cyanide Poisoning.

PubMed

Nath, Anjali K; Shi, Xu; Harrison, Devin L; Morningstar, Jordan E; Mahon, Sari; Chan, Adriano; Sips, Patrick; Lee, Jangwoen; MacRae, Calum A; Boss, Gerry R; Brenner, Matthew; Gerszten, Robert E; Peterson, Randall T

2017-05-18

Cisplatin holds an illustrious position in the history of chemistry most notably for its role in the virtual cure of testicular cancer. Here we describe a role for this small molecule in cyanide detoxification in vivo. Cyanide kills organisms as diverse as insects, fish, and humans within seconds to hours. Current antidotes exhibit limited efficacy and are not amenable to mass distribution requiring the development of new classes of antidotes. The binding affinity of the cyanide anion for the positively charged metal platinum is known to create an extremely stable complex in vitro. We therefore screened a panel of diverse cisplatin analogs and identified compounds that conferred protection from cyanide poisoning in zebrafish, mice, and rabbits. Cumulatively, this discovery pipeline begins to establish the characteristics of platinum ligands that influence their solubility, toxicity, and efficacy, and provides proof of concept that platinum-based complexes are effective antidotes for cyanide poisoning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Under the Microscope: Single-Domain Antibodies for Live-Cell Imaging and Super-Resolution Microscopy.

PubMed

Traenkle, Bjoern; Rothbauer, Ulrich

2017-01-01

Single-domain antibodies (sdAbs) have substantially expanded the possibilities of advanced cellular imaging such as live-cell or super-resolution microscopy to visualize cellular antigens and their dynamics. In addition to their unique properties including small size, high stability, and solubility in many environments, sdAbs can be efficiently functionalized according to the needs of the respective imaging approach. Genetically encoded intrabodies fused to fluorescent proteins (chromobodies) have become versatile tools to study dynamics of endogenous proteins in living cells. Additionally, sdAbs conjugated to organic dyes were shown to label cellular structures with high density and minimal fluorophore displacement making them highly attractive probes for super-resolution microscopy. Here, we review recent advances of the chromobody technology to visualize localization and dynamics of cellular targets and the application of chromobody-based cell models for compound screening. Acknowledging the emerging importance of super-resolution microscopy in cell biology, we further discuss advantages and challenges of sdAbs for this technology.

A high-throughput differential filtration assay to screen and select detergents for membrane proteins

PubMed Central

Vergis, James M.; Purdy, Michael D.; Wiener, Michael C.

2015-01-01

Structural studies on integral membrane proteins are routinely performed on protein–detergent complexes (PDCs) consisting of purified protein solubilized in a particular detergent. Of all the membrane protein crystal structures solved to date, a subset of only four detergents has been used in more than half of these structures. Unfortunately, many membrane proteins are not well behaved in these four detergents and/or fail to yield well-diffracting crystals. Identification of detergents that maintain the solubility and stability of a membrane protein is a critical step and can be a lengthy and “protein-expensive” process. We have developed an assay that characterizes the stability and size of membrane proteins exchanged into a panel of 94 commercially available and chemically diverse detergents. This differential filtration assay (DFA), using a set of filtered microplates, requires sub-milligram quantities of purified protein and small quantities of detergents and other reagents and is performed in its entirety in several hours. PMID:20667442

Hansen solubility parameters (HSP) for prescreening formulation of solid lipid nanoparticles (SLN): in vitro testing of curcumin-loaded SLN in MCF-7 and BT-474 cell lines.

PubMed

Doktorovova, Slavomira; Souto, Eliana B; Silva, Amélia M

2018-01-01

Curcumin, a phenolic compound from turmeric rhizome (Curcuma longa), has many interesting pharmacological effects, but shows very low aqueous solubility. Consequently, several drug delivery systems based on polymeric and lipid raw materials have been proposed to increase its bioavailability. Solid lipid nanoparticles (SLN), consisting of solid lipid matrix and a surfactant layer can load poorly water-soluble drugs, such as curcumin, deliver them at defined rates and enhance their intracellular uptake. In the present work, we demonstrate that, despite the drug's affinity to lipids frequently used in SLN production, the curcumin amount loaded in most SLN formulations may be too low to exhibit anticancer properties. The predictive curcumin solubility in solid lipids has been thoroughly analyzed by Hansen solubility parameters, in parallel with the lipid-screening solubility tests for a range of selected lipids. We identified the most suitable lipid materials for curcumin-loaded SLN, producing physicochemically stable particles with high encapsulation efficiency (>90%). Loading capacity of curcumin in SLN allowed preventing the cellular damage caused by cationic SLN on MCF-7 and BT-474 cells but was not sufficient to exhibit drug's anticancer properties. But curcumin-loaded SLN exhibited antioxidant properties, substantiating the conclusions that curcumin's effect in cancer cells is highly dose dependent.

About the solubility of reduced SWCNT in DMSO

NASA Astrophysics Data System (ADS)

Guan, Jingwen; Martinez-Rubi, Yadienka; Dénommée, Stéphane; Ruth, Dean; Kingston, Christopher T.; Daroszewska, Malgosia; Barnes, Michael; Simard, Benoit

2009-06-01

Single-walled carbon nanotubes (SWCNT) have been reduced with sodium naphthalide in THF. The reduced SWCNT are not only soluble in dimethylsulfoxide (DMSO) to form a stable solution/suspension, but also react spontaneously at room temperature with DMSO to evolve hydrocarbon gases and are converted into functionalized SWCNT. The degree of functionalization is about 2C% and the addends are mainly methyl and small oxygen-containing hydrocarbons. The functionalized SWCNT are apparently more soluble and stable in DMSO solution. It may open a new era for further processing and applications.

ChemBank: a small-molecule screening and cheminformatics resource database.

PubMed

Seiler, Kathleen Petri; George, Gregory A; Happ, Mary Pat; Bodycombe, Nicole E; Carrinski, Hyman A; Norton, Stephanie; Brudz, Steve; Sullivan, John P; Muhlich, Jeremy; Serrano, Martin; Ferraiolo, Paul; Tolliday, Nicola J; Schreiber, Stuart L; Clemons, Paul A

2008-01-01

ChemBank (http://chembank.broad.harvard.edu/) is a public, web-based informatics environment developed through a collaboration between the Chemical Biology Program and Platform at the Broad Institute of Harvard and MIT. This knowledge environment includes freely available data derived from small molecules and small-molecule screens and resources for studying these data. ChemBank is unique among small-molecule databases in its dedication to the storage of raw screening data, its rigorous definition of screening experiments in terms of statistical hypothesis testing, and its metadata-based organization of screening experiments into projects involving collections of related assays. ChemBank stores an increasingly varied set of measurements derived from cells and other biological assay systems treated with small molecules. Analysis tools are available and are continuously being developed that allow the relationships between small molecules, cell measurements, and cell states to be studied. Currently, ChemBank stores information on hundreds of thousands of small molecules and hundreds of biomedically relevant assays that have been performed at the Broad Institute by collaborators from the worldwide research community. The goal of ChemBank is to provide life scientists unfettered access to biomedically relevant data and tools heretofore available primarily in the private sector.

Sleep duration, restfulness, and screens in the sleep environment.

PubMed

Falbe, Jennifer; Davison, Kirsten K; Franckle, Rebecca L; Ganter, Claudia; Gortmaker, Steven L; Smith, Lauren; Land, Thomas; Taveras, Elsie M

2015-02-01

Associations of inadequate sleep with numerous health outcomes among youth necessitate identifying its modifiable determinants. Television (TV) has been associated with sleep curtailment, but little is known about small screens (eg, smartphones), which can be used in bed and emit notifications. Therefore, we examined associations of different screens in sleep environments with sleep duration and perceived insufficient rest or sleep. Participants included 2048 fourth- and seventh-graders participating in the Massachusetts Childhood Obesity Research Demonstration Study in 2012 to 2013. Using linear and log binomial regression, we examined cross-sectional associations of small screens and TVs in sleep environments and screen time with weekday sleep duration and perceived insufficient rest or sleep in the past week. Children who slept near a small screen (compared with never) reported 20.6 fewer minutes of sleep (95% confidence interval [CI], -29.7 to -11.4) and had a higher prevalence of perceived insufficient rest or sleep (prevalence ratio, 1.39; 95% CI, 1.21 to 1.60). Children who slept in a room with a TV (compared with no TV) reported 18.0 fewer minutes of sleep (95% CI, -27.9 to -8.1). TV or DVD viewing and video or computer game playing were associated with both sleep outcomes (P < .01). Some associations were stronger among Hispanic, non-Hispanic black, and older children (P < .05 for heterogeneity). Sleeping near a small screen, sleeping with a TV in the room, and more screen time were associated with shorter sleep durations. Presence of a small screen, but not a TV, in the sleep environment and screen time were associated with perceived insufficient rest or sleep. These findings caution against unrestricted screen access in children's bedrooms. Copyright © 2015 by the American Academy of Pediatrics.

Sleep Duration, Restfulness, and Screens in the Sleep Environment

PubMed Central

Davison, Kirsten K.; Franckle, Rebecca L.; Ganter, Claudia; Gortmaker, Steven L.; Smith, Lauren; Land, Thomas; Taveras, Elsie M.

2015-01-01

BACKGROUND AND OBJECTIVE: Associations of inadequate sleep with numerous health outcomes among youth necessitate identifying its modifiable determinants. Television (TV) has been associated with sleep curtailment, but little is known about small screens (eg, smartphones), which can be used in bed and emit notifications. Therefore, we examined associations of different screens in sleep environments with sleep duration and perceived insufficient rest or sleep. METHODS: Participants included 2048 fourth- and seventh-graders participating in the Massachusetts Childhood Obesity Research Demonstration Study in 2012 to 2013. Using linear and log binomial regression, we examined cross-sectional associations of small screens and TVs in sleep environments and screen time with weekday sleep duration and perceived insufficient rest or sleep in the past week. RESULTS: Children who slept near a small screen (compared with never) reported 20.6 fewer minutes of sleep (95% confidence interval [CI], −29.7 to −11.4) and had a higher prevalence of perceived insufficient rest or sleep (prevalence ratio, 1.39; 95% CI, 1.21 to 1.60). Children who slept in a room with a TV (compared with no TV) reported 18.0 fewer minutes of sleep (95% CI, −27.9 to −8.1). TV or DVD viewing and video or computer game playing were associated with both sleep outcomes (P < .01). Some associations were stronger among Hispanic, non-Hispanic black, and older children (P < .05 for heterogeneity). CONCLUSIONS: Sleeping near a small screen, sleeping with a TV in the room, and more screen time were associated with shorter sleep durations. Presence of a small screen, but not a TV, in the sleep environment and screen time were associated with perceived insufficient rest or sleep. These findings caution against unrestricted screen access in children’s bedrooms. PMID:25560435

Late-stage optimization of a tercyclic class of S1P3-sparing, S1P1 receptor agonists.

PubMed

Horan, Joshua C; Kuzmich, Daniel; Liu, Pingrong; DiSalvo, Darren; Lord, John; Mao, Can; Hopkins, Tamara D; Yu, Hui; Harcken, Christian; Betageri, Raj; Hill-Drzewi, Melissa; Patenaude, Lori; Patel, Monica; Fletcher, Kimberly; Terenzzio, Donna; Linehan, Brian; Xia, Heather; Patel, Mita; Studwell, Debbie; Miller, Craig; Hickey, Eugene; Levin, Jeremy I; Smith, Dustin; Kemper, Raymond A; Modis, Louise K; Bannen, Lynne C; Chan, Diva S; Mac, Morrison B; Ng, Stephanie; Wang, Yong; Xu, Wei; Lemieux, René M

2016-01-15

Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of small molecule inhibitors of cytokinesis and single cell wound repair

PubMed Central

Clark, Andrew G.; Sider, Jenny R.; Verbrugghe, Koen; Fenteany, Gabriel; von Dassow, George; Bement, William M.

2013-01-01

Screening of small molecule libraries offers the potential to identify compounds that inhibit specific biological processes and, ultimately, to identify macromolecules that are important players in such processes. To date, however, most screens of small molecule libraries have focused on identification of compounds that inhibit known proteins or particular steps in a given process, and have emphasized automated primary screens. Here we have used “low tech” in vivo primary screens to identify small molecules that inhibit both cytokinesis and single cell wound repair, two complex cellular processes that possess many common features. The “diversity set”, an ordered array of 1990 compounds available from the National Cancer Institute, was screened in parallel to identify compounds that inhibit cytokinesis in D. excentricus (sand dollar) embryos and single cell wound repair in X. laevis (frog) oocytes. Two small molecules were thus identified: Sph1 and Sph2. Sph1 reduces Rho activation in wound repair and suppresses formation of the spindle midzone during cytokinesis. Sph2 also reduces Rho activation in wound repair and may inhibit cytokinesis by blocking membrane fusion. The results identify two small molecules of interest for analysis of wound repair and cytokinesis, reveal that these processes are more similar than often realized and reveal the potential power of low tech screens of small molecule libraries for analysis of complex cellular processes. PMID:23125193

Thermodynamic phase behavior of API/polymer solid dispersions.

PubMed

Prudic, Anke; Ji, Yuanhui; Sadowski, Gabriele

2014-07-07

To improve the bioavailability of poorly soluble active pharmaceutical ingredients (APIs), these materials are often integrated into a polymer matrix that acts as a carrier. The resulting mixture is called a solid dispersion. In this work, the phase behaviors of solid dispersions were investigated as a function of the API as well as of the type and molecular weight of the carrier polymer. Specifically, the solubility of artemisinin and indomethacin was measured in different poly(ethylene glycol)s (PEG 400, PEG 6000, and PEG 35000). The measured solubility data and the solubility of sulfonamides in poly(vinylpyrrolidone) (PVP) K10 and PEG 35000 were modeled using the perturbed-chain statistical associating fluid theory (PC-SAFT). The results show that PC-SAFT predictions are in a good accordance with the experimental data, and PC-SAFT can be used to predict the whole phase diagram of an API/polymer solid dispersion as a function of the kind of API and polymer and of the polymer's molecular weight. This remarkably simplifies the screening process for suitable API/polymer combinations.

Does Screen Size Matter for Smartphones? Utilitarian and Hedonic Effects of Screen Size on Smartphone Adoption

PubMed Central

Kim, Ki Joon

2014-01-01

Abstract This study explores the psychological effects of screen size on smartphone adoption by proposing an extended Technology Acceptance Model (TAM) that integrates an empirical comparison between large and small screens with perceived control, affective quality, and the original TAM constructs. A structural equation modeling analysis was conducted on data collected from a between-subjects experiment (N=130) in which users performed a web-based task on a smartphone with either a large (5.3 inches) or a small (3.7 inches) screen. Results show that a large screen, compared to a small screen, is likely to lead to higher smartphone adoption by simultaneously promoting both the utilitarian and hedonic qualities of smartphones, which in turn positively influence perceived ease of use of—and attitude toward—the device respectively. Implications and directions for future research are discussed. PMID:24694112

Does screen size matter for smartphones? Utilitarian and hedonic effects of screen size on smartphone adoption.

PubMed

Kim, Ki Joon; Sundar, S Shyam

2014-07-01

This study explores the psychological effects of screen size on smartphone adoption by proposing an extended Technology Acceptance Model (TAM) that integrates an empirical comparison between large and small screens with perceived control, affective quality, and the original TAM constructs. A structural equation modeling analysis was conducted on data collected from a between-subjects experiment (N=130) in which users performed a web-based task on a smartphone with either a large (5.3 inches) or a small (3.7 inches) screen. Results show that a large screen, compared to a small screen, is likely to lead to higher smartphone adoption by simultaneously promoting both the utilitarian and hedonic qualities of smartphones, which in turn positively influence perceived ease of use of-and attitude toward-the device respectively. Implications and directions for future research are discussed.

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

Reilly, Sean Douglas; Smith, Paul Herrick; Jarvinen, Gordon D.

Understanding the water solubility of plutonium and uranium compounds and residues at TA-55 is necessary to provide a technical basis for appropriate criticality safety, safety basis and accountability controls. Individual compound solubility was determined using published solubility data and solution thermodynamic modeling. Residue solubility was estimated using a combination of published technical reports and process knowledge of constituent compounds. The scope of materials considered includes all compounds and residues at TA-55 as of March 2016 that contain Pu-239 or U-235 where any single item in the facility has more than 500 g of nuclear material. This analysis indicates that themore » following materials are not appreciably soluble in water: plutonium dioxide (IDC=C21), plutonium phosphate (IDC=C66), plutonium tetrafluoride (IDC=C80), plutonium filter residue (IDC=R26), plutonium hydroxide precipitate (IDC=R41), plutonium DOR salt (IDC=R42), plutonium incinerator ash (IDC=R47), uranium carbide (IDC=C13), uranium dioxide (IDC=C21), U 3O 8 (IDC=C88), and uranium filter residue (IDC=R26). This analysis also indicates that the following materials are soluble in water: plutonium chloride (IDC=C19) and uranium nitrate (IDC=C52). Equilibrium calculations suggest that PuOCl is water soluble under certain conditions, but some plutonium processing reports indicate that it is insoluble when present in electrorefining residues (R65). Plutonium molten salt extraction residues (IDC=R83) contain significant quantities of PuCl 3, and are expected to be soluble in water. The solubility of the following plutonium residues is indeterminate due to conflicting reports, insufficient process knowledge or process-dependent composition: calcium salt (IDC=R09), electrorefining salt (IDC=R65), salt (IDC=R71), silica (IDC=R73) and sweepings/screenings (IDC=R78). Solution thermodynamic modeling also indicates that fire suppression water buffered with a commercially-available phosphate buffer would significantly reduce the solubility of PuCl 3 by the precipitation of PuPO 4.« less

Effectiveness of screening aqueous contrast swallow in detecting clinically significant anastomotic leaks after esophagectomy.

PubMed

Tirnaksiz, M B; Deschamps, C; Allen, M S; Johnson, D C; Pairolero, P C

2005-01-01

Aqueous contrast swallow study is recommended as a screening procedure for the evaluation of esophageal anastomotic integrity following esophagectomy. The aim of this study was to assess the accuracy of water-soluble contrast swallow screening as a predictor of clinically significant anastomotic leak in patients with esophagectomy. The records of 505 consecutive patients undergoing esophagectomy in Mayo Clinic from January 1991 through December 1995 were retrospectively reviewed. 464 (92%) patients had water-soluble contrast swallows performed in the early postoperative period (median postoperative day 7, range 4-11 days). A total of 39 radiological leaks were obtained but only 17 of these had clinical signs of anastomotic leakage. Furthermore, 25 patients who had normal swallow study developed a clinical anastomotic leak. There were therefore 22 (4.7%) false positive and 25 (5.4%) false negative results giving values for the specificity, sensitivity and false negative error rate of the radiological examination of 94.7, 40.4, and 59.5% respectively. Aspiration of the contrast agent was noted on fluoroscopy in 30 (6.5%) patients. Only 2 (0.4%) patients developed aqueous contrast agent-caused aspiration pneumonia. There was no procedure-related mortality. While radiological assessment of esophageal anastomoses in the early postoperative period using aqueous contrast agents appears to be a relatively safe procedure, the poor sensitivity and high false negative error rate of this technique, when performed on postoperative day 7 and in a series with clinical anastomotic leak rate of 9%, is insufficient for it to be worthwhile as a screening procedure. Copyright (c) 2005 S. Karger AG, Basel.

Emphysema and soluble CD14 are associated with pulmonary nodules in HIV-infected patients: implications for lung cancer screening.

PubMed

Triplette, Matthew; Sigel, Keith M; Morris, Alison; Shahrir, Shahida; Wisnivesky, Juan P; Kong, Chung Y; Diaz, Phillip T; Petraglia, Alycia; Crothers, Kristina

2017-07-31

Lung cancer screening may benefit HIV-infected (HIV) smokers because of an elevated risk of lung cancer, but may have unique harms because of HIV-specific risk factors for false-positive screens. This study seeks to understand whether inflammatory biomarkers and markers of chronic lung disease are associated with noncalcified nodules at least 4 mm (NCN) in HIV compared with uninfected patients. This is a cohort study of Examinations of HIV-Associated Lung Emphysema (EXHALE), including 158 HIV and 133 HIV-uninfected participants. Participants underwent a laboratory assessment [including measurement of D-dimer, interleukin 6, and soluble CD14 (sCD14)], chest computed tomography (CT), and pulmonary function testing. We created multivariable logistic regression models to determine predictors of NCN in the participants stratified by HIV status, with attention to semiqualitative scoring of radiographic emphysema, markers of pulmonary function, and inflammatory biomarkers. Of the 291 participants, 69 had NCN on chest CT. As previously reported, there was no difference in prevalence of these nodules by HIV status. Emphysema and elevated sCD14 demonstrated an association with NCN in HIV participants independent of smoking status, CD4 cell count, HIV viral load, and pulmonary function. Emphysema and sCD14, a marker of immune activation, was associated with a higher prevalence of NCN on chest CT in HIV participants. Patients with chronic immune activation and emphysema may be at higher risk for both false-positive findings and incident lung cancer, thus screening in this group requires further study to understand the balance of benefits and harms.

Development of a nanosuspension for iv administration: From miniscale screening to a freeze dried formulation.

PubMed

Frank, Kerstin J; Boeck, Georg

2016-05-25

The aim was to develop a nanosuspension of the poorly soluble BI XX. The nanosuspension is intended for intravenous (iv) administration in preclinical studies and should not cause any unwanted side effects. Thus, only stabilizers that are accepted for iv application should be used and isotonicity, euhydria and the absence of living microorganisms were targeted. Suspensions were prepared in a ball-mill (mixing mill MM 400 from Retsch). There were various vials used as containers; HPLC-vials were used for the small scale screening of stabilizers and injection vials for preparation of larger quantities of the nanosuspensions. Particle size distribution was analyzed by laser diffraction measurement (Mastersizer 2000). Lyophilization was used for processing of the suspensions (Christ freeze dryer). Stable nanosuspensions (d90 remained <1μm up to 7days) were prepared with several FDA-accepted stabilizers. Freeze drying was evaluated for one formulation containing 2% of the API, 0.5% of arginine and 4% of mannitol. The particle size distribution before freeze drying and after re-dispersion was comparable. After milling for 2h, no living microorganisms were detected in the nanosuspension. Various FDA accepted excipients were identified which resulted in stable nanosuspensions of BI XX. The most stable formulation was successfully freeze dried. It was proven that milling in the ball-mill decreases the presence of living microorganisms. Copyright © 2016. Published by Elsevier B.V.

Effect of composition of simulated intestinal media on the solubility of poorly soluble compounds investigated by design of experiments.

PubMed

Madsen, Cecilie Maria; Feng, Kung-I; Leithead, Andrew; Canfield, Nicole; Jørgensen, Søren Astrup; Müllertz, Anette; Rades, Thomas

2018-01-01

The composition of the human intestinal fluids varies both intra- and inter-individually. This will influence the solubility of orally administered drug compounds, and hence, the absorption and efficacy of compounds displaying solubility limited absorption. The purpose of this study was to assess the influence of simulated intestinal fluid (SIF) composition on the solubility of poorly soluble compounds. Using a Design of Experiments (DoE) approach, a set of 24 SIF was defined within the known compositions of human fasted state intestinal fluid. The SIF were composed of phospholipid, bile salt, and different pH, buffer capacities and osmolarities. On a small scale semi-robotic system, the solubility of 6 compounds (aprepitant, carvedilol, felodipine, fenofibrate, probucol, and zafirlukast) was determined in the 24 SIF. Compound specific models, describing key factors influencing the solubility of each compound, were identified. Although all models were different, the level of phospholipid and bile salt, the pH, and the interactions between these, had the biggest influences on solubility overall. Thus, a reduction of the DoE from five to three factors was possible (11-13 media), making DoE solubility studies feasible compared to single SIF solubility studies. Applying this DoE approach will lead to a better understanding of the impact of intestinal fluid composition on the solubility of a given drug compound. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Term Fungal Inhibitory Activity of Water-Soluble Extracts of Phaseolus vulgaris cv. Pinto and Sourdough Lactic Acid Bacteria during Bread Storage▿

PubMed Central

Coda, Rossana; Rizzello, Carlo G.; Nigro, Franco; De Angelis, Maria; Arnault, Philip; Gobbetti, Marco

2008-01-01

The antifungal activity of proteinaceous compounds from different food matrices was investigated. In initial experiments, water-soluble extracts of wheat sourdoughs, cheeses, and vegetables were screened by agar diffusion assays with Penicillium roqueforti DPPMAF1 as the indicator fungus. Water-soluble extracts of sourdough fermented with Lactobacillus brevis AM7 and Phaseolus vulgaris cv. Pinto were selected for further study. The crude water-soluble extracts of L. brevis AM7 sourdough and P. vulgaris cv. Pinto had a MIC of 40 mg of peptide/ml and 30.9 mg of protein/ml, respectively. MICs were markedly lower when chemically synthesized peptides or partially purified protein fractions were used. The water-soluble extract of P. vulgaris cv. Pinto showed inhibition toward a large number of fungal species isolated from bakeries. Phaseolin alpha-type precursor, phaseolin, and erythroagglutinating phytohemagglutinin precursor were identified in the water-soluble extract of P. vulgaris cv. Pinto by nano liquid chromatography-electrospray ionization-tandem mass spectrometry. When the antifungal activity was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all three proteins were inhibitory. A mixture of eight peptides was identified from the water-soluble extract of sourdough L. brevis AM7, and five of these exhibited inhibitory activity. Bread was made at the pilot plant scale by sourdough fermentation with L. brevis AM7 and addition of the water-soluble extract (27%, vol/wt; 5 mg of protein/ml) of P. vulgaris cv. Pinto. Slices of bread packed in polyethylene bags did not show contamination by fungi until at least 21 days of storage at room temperature, a level of protection comparable to that afforded by 0.3% (wt/wt) calcium propionate. PMID:18849463

Long-term fungal inhibitory activity of water-soluble extracts of Phaseolus vulgaris cv. Pinto and sourdough lactic acid bacteria during bread storage.

PubMed

Coda, Rossana; Rizzello, Carlo G; Nigro, Franco; De Angelis, Maria; Arnault, Philip; Gobbetti, Marco

2008-12-01

The antifungal activity of proteinaceous compounds from different food matrices was investigated. In initial experiments, water-soluble extracts of wheat sourdoughs, cheeses, and vegetables were screened by agar diffusion assays with Penicillium roqueforti DPPMAF1 as the indicator fungus. Water-soluble extracts of sourdough fermented with Lactobacillus brevis AM7 and Phaseolus vulgaris cv. Pinto were selected for further study. The crude water-soluble extracts of L. brevis AM7 sourdough and P. vulgaris cv. Pinto had a MIC of 40 mg of peptide/ml and 30.9 mg of protein/ml, respectively. MICs were markedly lower when chemically synthesized peptides or partially purified protein fractions were used. The water-soluble extract of P. vulgaris cv. Pinto showed inhibition toward a large number of fungal species isolated from bakeries. Phaseolin alpha-type precursor, phaseolin, and erythroagglutinating phytohemagglutinin precursor were identified in the water-soluble extract of P. vulgaris cv. Pinto by nano liquid chromatography-electrospray ionization-tandem mass spectrometry. When the antifungal activity was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all three proteins were inhibitory. A mixture of eight peptides was identified from the water-soluble extract of sourdough L. brevis AM7, and five of these exhibited inhibitory activity. Bread was made at the pilot plant scale by sourdough fermentation with L. brevis AM7 and addition of the water-soluble extract (27%, vol/wt; 5 mg of protein/ml) of P. vulgaris cv. Pinto. Slices of bread packed in polyethylene bags did not show contamination by fungi until at least 21 days of storage at room temperature, a level of protection comparable to that afforded by 0.3% (wt/wt) calcium propionate.

Development and characterization of nanostructured mists with potential for actively targeting poorly water-soluble compounds into the lungs.

PubMed

Nesamony, Jerry; Kalra, Ashish; Majrad, Mohamed S; Boddu, Sai Hanuman Sagar; Jung, Rose; Williams, Frederick E; Schnapp, Alaina M; Nauli, Surya M; Kalinoski, Andrea L

2013-10-01

To formulate nanoemulsions (NE) with potential for delivering poorly water-soluble drugs to the lungs. A self nanoemulsifying composition consisting of cremophor RH 40, PEG 400 and labrafil M 2125 CS was selected after screening potential excipients. The solubility of carbamazepine, a poorly water-soluble drug, was tested in the formulation components. Oil-in-water (o/w) NEs were characterized using dynamic light scattering, electrophoretic light scattering, transmission electron microscopy (TEM) and differential scanning calorimetry. NEs were nebulized into a mist using a commercial nebulizer and characterized using laser diffraction and TEM. An aseptic method was developed for preparing sterile NEs. Biocompatibility of the formulation was evaluated on NIH3T3 cells using MTT assay. In vitro permeability of the formulation was tested in zebra fish eggs, HeLa cells, and porcine lung tissue. NEs had neutrally charged droplets of less than 20 nm size. Nebulized NEs demonstrated an o/w nanostructure. The mist droplets were of size less than 5 μm. Sterility testing and cytotoxicity results validated that the NE was biocompatible and sterile. In vitro tests indicated oil nanodroplets penetrating intracellularly through biological membranes. The nanoemulsion mist has the potential for use as a pulmonary delivery system for poorly water-soluble drugs.

Using Environment-Sensitive Fluorescent Probes to Characterize Liquid-Liquid Phase Separation in Supersaturated Solutions of Poorly Water Soluble Compounds.

PubMed

Raina, Shweta A; Alonzo, David E; Zhang, Geoff G Z; Gao, Yi; Taylor, Lynne S

2015-11-01

Highly supersaturated aqueous solutions of poorly soluble compounds can undergo liquid-liquid phase separation (LLPS) when the concentration exceeds the "amorphous solubility". This phenomenon has been widely observed during high throughput screening of new molecular entities as well as during the dissolution of amorphous solid dispersions. In this study, we have evaluated the use of environment-sensitive fluorescence probes to investigate the formation and properties of the non-crystalline drug-rich aggregates formed in aqueous solutions as a result of LLPS. Six different environment-sensitive fluorophores were employed to study LLPS in highly supersaturated solutions of several model compounds, all dihydropyridine derivatives. Each fluoroprobe exhibited a large hypsochromic shift with decreasing environment polarity. Upon drug aggregate formation, the probes partitioned into the drug-rich phase and exhibited changes in emission wavelength and intensity consistent with sensing a lower polarity environment. The LLPS onset concentrations determined using the fluorescence measurements were in good agreement with light scattering measurements as well as theoretically estimated amorphous solubility values. Environment-sensitive fluorescence probes are useful to help understand the phase behavior of highly supersaturated aqueous solutions, which in turn is important in the context of developing enabling formulations for poorly soluble compounds.

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

Siol, Sebastian; Holder, Aaron; Ortiz, Brenden R.

Here, the controlled decomposition of metastable alloys is an attractive route to form nanostructured thermoelectric materials with reduced thermal conductivity. The ternary SnTe–MnTe and SnTe–SnSe heterostructural alloys have been demonstrated as promising materials for thermoelectric applications. In this work, the quaternary Sn 1–yMnyTe 1–xSe x phase space serves as a relevant model system to explore how a combination of computational and combinatorial-growth methods can be used to study equilibrium and non-equilibrium solubility limits. Results from first principle calculations indicate low equilibrium solubility for x,y < 0.05 that are in good agreement with results obtained from bulk equilibrium synthesis experiments andmore » predict significantly higher spinodal limits. An experimental screening using sputtered combinatorial thin film sample libraries showed a remarkable increase in non-equilibrium solubility for x,y > 0.2. These theoretical and experimental results were used to guide the bulk synthesis of metastable alloys. The ability to reproduce the non-equilibrium solubility levels in bulk materials indicates that such theoretical calculations and combinatorial growth can inform bulk synthetic routes. Further, the large difference between equilibrium and non-equilibrium solubility limits in Sn 1–yMn yTe 1–xSe x indicates these metastable alloys are attractive in terms of nano-precipitate formation for potential thermoelectric applications.« less

Rate-induced solubility and suppression of the first-order phase transition in olivine LiFePO4.

PubMed

Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P; Brownrigg, Alex; Wright, Jonathan P; van Dijk, Niels H; Wagemaker, Marnix

2014-05-14

The impact of ultrahigh (dis)charge rates on the phase transition mechanism in LiFePO4 Li-ion electrodes is revealed by in situ synchrotron diffraction. At high rates the solubility limits in both phases increase dramatically, causing a fraction of the electrode to bypass the first-order phase transition. The small transforming fraction demonstrates that nucleation rates are consequently not limiting the transformation rate. In combination with the small fraction of the electrode that transforms at high rates, this indicates that higher performances may be achieved by further optimizing the ionic/electronic transport in LiFePO4 electrodes.

Soluble 1:1 complexes and insoluble 3:2 complexes - Understanding the phase-solubility diagram of hydrocortisone and γ-cyclodextrin.

PubMed

Schönbeck, Christian; Madsen, Tobias L; Peters, Günther H; Holm, René; Loftsson, Thorsteinn

2017-10-15

The molecular mechanisms underlying the drug-solubilizing properties of γ-cyclodextrin were explored using hydrocortisone as a model drug. The B S -type phase-solubility diagram of hydrocortisone with γ-cyclodextrin was thoroughly characterized by measuring the concentrations of hydrocortisone and γ-cyclodextrin in solution and the solid phase. The drug-solubilizer interaction was also studied by isothermal titration calorimetry from which a precise value of the 1:1 binding constant (K 11 =4.01mM -1 at 20°C) was obtained. The formation of water-soluble 1:1 complexes is responsible for the initial increase in hydrocortisone solubility while the precipitation of entities with a 3:2 ratio of γ-cyclodextrin:hydrocortisone is responsible for the plateau and the ensuing strong decrease in solubility once all solid hydrocortisone is used up. The complete phase-solubility diagram is well accounted for by a model employing the 1:1 binding constant and the solubility product of the precipitating 3:2 entity (K 32 S =5.51 mM 5 ). For such systems, a small surplus of γ-cyclodextrin above the optimum concentration may result in a significant decrease in drug solubility, and the implications for drug formulations are briefly discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Vapor condensation onto a non-volatile liquid drop

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

Inci, Levent; Bowles, Richard K., E-mail: richard.bowles@usask.ca

2013-12-07

Molecular dynamics simulations of miscible and partially miscible binary Lennard–Jones mixtures are used to study the dynamics and thermodynamics of vapor condensation onto a non-volatile liquid drop in the canonical ensemble. When the system volume is large, the driving force for condensation is low and only a submonolayer of the solvent is adsorbed onto the liquid drop. A small degree of mixing of the solvent phase into the core of the particles occurs for the miscible system. At smaller volumes, complete film formation is observed and the dynamics of film growth are dominated by cluster-cluster coalescence. Mixing into the coremore » of the droplet is also observed for partially miscible systems below an onset volume suggesting the presence of a solubility transition. We also develop a non-volatile liquid drop model, based on the capillarity approximations, that exhibits a solubility transition between small and large drops for partially miscible mixtures and has a hysteresis loop similar to the one observed in the deliquescence of small soluble salt particles. The properties of the model are compared to our simulation results and the model is used to study the formulation of classical nucleation theory for systems with low free energy barriers.« less

Improved method for extraction of castor seed for toxin determination

USDA-ARS?s Scientific Manuscript database

The effort to identify castor seeds with low ricin content is considered to be a key to increasing cultivation of the castor plant for industrial applications. The procedure used to obtain soluble protein from the seed is a limiting factor for screening large numbers of seeds. Usually, the seed is...

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation.

PubMed

Paluch, Andrew S; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L

2015-01-28

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes.

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation

NASA Astrophysics Data System (ADS)

Paluch, Andrew S.; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L.

2015-01-01

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes.

Biotransformation of potentially persistent alkylphenols in natural seawater.

PubMed

Lofthus, Synnøve; Almås, Inger K; Evans, Peter; Pelz, Oliver; Brakstad, Odd Gunnar

2016-08-01

Produced water (PW) discharged to the marine environment may contain both natural substances and industrial chemicals that are potentially persistent, bioaccumulating and toxic (PBT). Identification of substances as PBT is dependent upon accurate assessment of biodegradation rates, but these measurements can be impeded where substances exhibit inherently low solubility in water. Examples of substances of this kind include some alkylated phenols (APs). Biotransformation of three APs, suspected to be PBT compounds in PW, was investigated by adopting a new methodology in which they were immobilized to hydrophobic adsorbents submerged in natural seawater. These compounds were not ready biodegradable by conventional screening biochemical oxygen demand (BOD) methods at high concentrations (2 mg/L). However, potential biodegradability for two of the three APs were demonstrated by the immobilization method at low concentrations (appr. 100 μg/L), with biotransformation half-lives <50 days. Thus, standard screening tests should be supplemented by biodegradation methods suited for testing of poorly soluble substances before the persistence of potential PBT substances are defined. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmaceutical Cocrystal of Piroxicam: Design, Formulation and Evaluation

PubMed Central

Panzade, Prabhakar; Shendarkar, Giridhar; Shaikh, Sarfaraj; Balmukund Rathi, Pavan

2017-01-01

Purpose: Cocrystallisation of drug with coformers is a promising approach to alter the solid sate properties of drug substances like solubility and dissolution. The objective of the present work was to prepare, formulate and evaluate the piroxicam cocrystal by screening various coformers. Methods: Cocrystals of piroxicam were prepared by dry grinding method. The melting point and solubility of crystalline phase was determined. The potential cocrystal was characterized by DSC, IR, XRPD. Other pharmaceutical properties like solubility and dissolution rate were also evaluated. Orodispersible tablets of piroxicam cocrystal were formulated, optimized and evaluated using 32 factorial design. Results: Cocrystals of piroxicam-sodium acetate revealed the variation in melting points and solubility. The cocrystals were obtained in 1:1 ratio with sodium acetate. The analysis of Infrared explicitly indicated the shifting of characteristic bands of piroxicam. The X-Ray Powder Diffraction pattern denoted the crystallinity of cocrystals and noteworthy difference in 2θ value of intense peaks. Differential scanning calorimetry spectra of cocrystals indicated altered endotherms corresponding to melting point. The pH solubility profile of piroxicam showed sigmoidal curve, which authenticated the pKa-dependent solubility. Piroxicam cocrystals also exhibited a similar pH-solubility profile. The cocrystals exhibited faster dissolution rate owing to cocrystallization as evident from 30% increase in the extent of dissolution. The orodispersible tablets of piroxicam cocrystals were successfully prepared by direct compression method using crosscarmelose sodium as superdisintegrant with improved disintegration time (30 sec) and dissolution rate. Conclusion: The piroxicam cocrystal with modified properties was prepared with sodium acetate and formulated as orodispersible tablets having faster disintegration and greater dissolution rate. PMID:29071222

Pharmaceutical Cocrystal of Piroxicam: Design, Formulation and Evaluation.

PubMed

Panzade, Prabhakar; Shendarkar, Giridhar; Shaikh, Sarfaraj; Balmukund Rathi, Pavan

2017-09-01

Purpose: Cocrystallisation of drug with coformers is a promising approach to alter the solid sate properties of drug substances like solubility and dissolution. The objective of the present work was to prepare, formulate and evaluate the piroxicam cocrystal by screening various coformers. Methods: Cocrystals of piroxicam were prepared by dry grinding method. The melting point and solubility of crystalline phase was determined. The potential cocrystal was characterized by DSC, IR, XRPD. Other pharmaceutical properties like solubility and dissolution rate were also evaluated. Orodispersible tablets of piroxicam cocrystal were formulated, optimized and evaluated using 3 2 factorial design. Results: Cocrystals of piroxicam-sodium acetate revealed the variation in melting points and solubility. The cocrystals were obtained in 1:1 ratio with sodium acetate. The analysis of Infrared explicitly indicated the shifting of characteristic bands of piroxicam. The X-Ray Powder Diffraction pattern denoted the crystallinity of cocrystals and noteworthy difference in 2θ value of intense peaks. Differential scanning calorimetry spectra of cocrystals indicated altered endotherms corresponding to melting point. The pH solubility profile of piroxicam showed sigmoidal curve, which authenticated the pKa-dependent solubility. Piroxicam cocrystals also exhibited a similar pH-solubility profile. The cocrystals exhibited faster dissolution rate owing to cocrystallization as evident from 30% increase in the extent of dissolution. The orodispersible tablets of piroxicam cocrystals were successfully prepared by direct compression method using crosscarmelose sodium as superdisintegrant with improved disintegration time (30 sec) and dissolution rate. Conclusion: The piroxicam cocrystal with modified properties was prepared with sodium acetate and formulated as orodispersible tablets having faster disintegration and greater dissolution rate.

An in vivo multiplexed small molecule screening platform

PubMed Central

Yang, Dian; Ogasawara, Daisuke; Dix, Melissa M.; Rogers, Zoë N.; Chuang, Chen-Hua; McFarland, Christopher D.; Chiou, Shin-Heng; Brown, J. Mark; Cravatt, Benjamin F.; Bogyo, Matthew; Winslow, Monte M.

2016-01-01

Phenotype-based small molecule screening is a powerful method to identify regulators of cellular function. However, such screens are generally performed in vitro using conditions that do not necessarily model complex physiological conditions or disease states. Here, we use molecular cell barcoding to enable direct in vivo phenotypic screening of libraries of small molecules. The multiplexed nature of this approach allows rapid in vivo analysis of hundreds to thousands of compounds. Using this platform, we screened >700 covalent inhibitors directed towards hydrolases for their effect on pancreatic cancer metastatic seeding. We identified multiple hits and confirmed the relevant target of one compound as the lipase ABHD6. Pharmacological and genetic studies confirmed the role of this enzyme as a regulator of metastatic fitness. Our results highlight the applicability of this multiplexed screening platform for investigating complex processes in vivo. PMID:27617390

Radionuclide solubility and speciation studies for the Yucca Mountain site characterization project

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

Nitsche, H.; Roberts, K.; Prussin, T.

1992-12-01

Yucca Mountain, Nevada, USA, is being investigated for its suitability as a potential site for a geologic nuclear waste repository. As part of the site characterization studies, actinide solubilities and speciations were studied at pH 6, 7, and 8.5 at 25{degrees}C in two different groundwaters from the vicinity of Yucca Mountain. The groundwaters differ substantially in total dissolved carbonate concentration, and to a lesser extent in ionic strength. In the waters with higher carbonate content, the solubilities of neptunium(V) decreased, whereas those americium(III) increased at 25{degrees}KC and decreased at 60{degrees}C. The solids formed were sodium neptunium carbonates and americium hydroxycarbonates.more » Plutonium solubilities did not significantly change with changing water composition because the solubility-controlling solids were mostly amorphous Pu(IV) polymers that contained only small amounts of carbonate.« less

Radionuclide solubility and speciation studies for the Yucca Mountain site characterization project

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

Nitsche, H.; Roberts, K.; Prussin, T.

1993-12-31

Yucca Mountain, Nevada, U.S.A., is being investigated for its suitability as a potential site for a geologic nuclear waste repository. As part of the site characterization studies, actinide solubilities and speciations were studied at pH 6, 7, and 8.5 at 25{degrees} and 60{degrees}C in two different groundwaters from the vicinity of Yucca Mountain. The groundwaters differ substantially in total dissolved carbonate concentration, and to a lesser extent in ionic strength. In the waters with higher carbonate content, the solubilities of neptunium(V) decreased, whereas those of americium (III) increased at 25{degrees}C and decreased at 60{degrees}C. The solids formed were sodium neptuniummore » carbonates and americium hydroxycarbonates. Plutonium solubilities did not significantly change with changing water composition because the solubility-controlling solids were mostly amorphous Pu(IV) polymers that contained only small amounts of carbonate.« less

Phase diagram of a crystalline protein: Determination of the solubility of concanavalin A by a microquantitation assay

NASA Astrophysics Data System (ADS)

Mikol, Vincent; Giegé, Richard

1989-09-01

A quick and miniature method has been devised for determining protein solubility and used to investigate the equilibrium solubility of concanavalin A from the Jack Bean with its crystals as a function of ammonium sulfate concentration, temperature and pH. The crystals were characterized by X-ray diffraction and their morphologies related to the corresponding solubilities. The protein solution concentration was estimated out of small crystallizing drops using a rapid and sensitive microassay. Measurements of protein quantity were carried out in 96-well microplates in an automatic spectrophotometer. The resulting phase diagram has permitted to analyse the solubility of concanavalin A, to estimate supersaturation and to devise readily new ways of crystal growth of this lectin, namely by pH and temperature variations. Moreover, the approach is proved to be a valuable tool to design crystallization experiments of new molecules and to improve and control protein crystal growth.

Computer Simulations of Small Molecules in Membranes: Insights from Computer Simulations into the Interactions of Small Molecules with Lipid Bilayers

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; New, Michael H.; Schweighofer, Karl; Wilson, Michael A.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

Two of Ernest Overton's lasting contributions to biology are the Meyer-Overton relationship between the potency of an anesthetic and its solubility in oil, and the Overton rule which relates the permeability of a membrane to the oil-water partition coefficient of the permeating molecule. A growing body of experimental evidence, however, cannot be reconciled with these theories. In particular, the molecular nature of membranes, unknown to Overton, needs to be included in any description of these phenomena. Computer simulations are ideally suited for providing atomic-level information about the behavior of small molecules in membranes. The authors discuss simulation studies relevant to Overton's ideas. Through simulations it was found that anesthetics tend to concentrate at interfaces and their anesthetic potency correlates better with solubility at the water-membrane interface than with solubility in oil. Simulation studies of membrane permeation revealed the anisotropic nature of the membranes, as evidenced, for example, by the highly nonuniform distribution of free volume in the bilayer. This, in turn, influences the diffusion rates of solutes, which increase with the depth in the membrane. Small solutes tend to move by hopping between voids in the bilayer, and this hopping motion may be responsible for the deviation from the Overton rule of the permeation rates of these molecules.

Development of a shear stress-free microfluidic gradient generator capable of quantitatively analyzing single-cell morphology.

PubMed

Barata, David; Spennati, Giulia; Correia, Cristina; Ribeiro, Nelson; Harink, Björn; van Blitterswijk, Clemens; Habibovic, Pamela; van Rijt, Sabine

2017-09-07

Microfluidics, the science of engineering fluid streams at the micrometer scale, offers unique tools for creating and controlling gradients of soluble compounds. Gradient generation can be used to recreate complex physiological microenvironments, but is also useful for screening purposes. For example, in a single experiment, adherent cells can be exposed to a range of concentrations of the compound of interest, enabling high-content analysis of cell behaviour and enhancing throughput. In this study, we present the development of a microfluidic screening platform where, by means of diffusion, gradients of soluble compounds can be generated and sustained. This platform enables the culture of adherent cells under shear stress-free conditions, and their exposure to a soluble compound in a concentration gradient-wise manner. The platform consists of five serial cell culture chambers, all coupled to two lateral fluid supply channels that are used for gradient generation through a source-sink mechanism. Furthermore, an additional inlet and outlet are used for cell seeding inside the chambers. Finite element modeling was used for the optimization of the design of the platform and for validation of the dynamics of gradient generation. Then, as a proof-of-concept, human osteosarcoma MG-63 cells were cultured inside the platform and exposed to a gradient of Cytochalasin D, an actin polymerization inhibitor. This set-up allowed us to analyze cell morphological changes over time, including cell area and eccentricity measurements, as a function of Cytochalasin D concentration by using fluorescence image-based cytometry.

Smart polyelectrolyte microcapsules as carriers for water-soluble small molecular drug.

PubMed

Song, Weixing; He, Qiang; Möhwald, Helmuth; Yang, Yang; Li, Junbai

2009-10-15

Heat treatment is introduced as a simple method for the encapsulation of low molecular weight water-soluble drugs within layer-by-layer assembled microcapsules. A water-soluble drug, procainamide hydrochloride, could thus be encapsulated in large amount and enriched by more than 2 orders of magnitude in the assembled PDADMAC/PSS capsules. The shrunk capsules could control the unloading rate of drugs, and the drugs could be easily unloaded using ultrasonic treatment. The encapsulated amount could be quantitatively controlled via the drug concentration in the bulk. We also found that smaller capsules possess higher encapsulation capability.

A Bifunctional Dimethylsulfoxide Substitute Enhances the Aqueous Solubility of Small Organic Molecules

PubMed Central

Sprachman, Melissa M.

2012-01-01

Abstract An oxetane-substituted sulfoxide has demonstrated potential as a dimethylsulfoxide substitute for enhancing the dissolution of organic compounds with poor aqueous solubilities. This sulfoxide may find utility in applications of library storage and biological assays. For the model compounds studied, significant solubility enhancements were observed using the sulfoxide as a cosolvent in aqueous media. Brine shrimp, breast cancer (MDA-MB-231), and liver cell line (HepG2) toxicity data for the new additive are also presented, in addition to comparative IC50 values for a series of PKD1 inhibitors. PMID:22192308

Plant cell wall glycosyltransferases: High-throughput recombinant expression screening and general requirements for these challenging enzymes

DOE PAGES

Welner, Ditte Hededam; Shin, David; Tomaleri, Giovani P.; ...

2017-06-09

Molecular characterization of plant cell wall glycosyltransferases is a critical step towards understanding the biosynthesis of the complex plant cell wall, and ultimately for efficient engineering of biofuel and agricultural crops. The majority of these enzymes have proven very difficult to obtain in the needed amount and purity for such molecular studies, and recombinant cell wall glycosyltransferase production efforts have largely failed. A daunting number of strategies can be employed to overcome this challenge, including optimization of DNA and protein sequences, choice of expression organism, expression conditions, coexpression partners, purification methods, and optimization of protein solubility and stability. Hence researchersmore » are presented with thousands of potential conditions to test. Ultimately, the subset of conditions that will be sampled depends on practical considerations and prior knowledge of the enzyme(s) being studied. We have developed a rational approach to this process. We devise a pipeline comprising in silico selection of targets and construct design, and high-throughput expression screening, target enrichment, and hit identification. We have applied this pipeline to a test set of Arabidopsis thaliana cell wall glycosyltransferases known to be challenging to obtain in soluble form, as well as to a library of cell wall glycosyltransferases from other plants including agricultural and biofuel crops. The screening results suggest that recombinant cell wall glycosyltransferases in general have a very low soluble: Insoluble ratio in lysates from heterologous expression cultures, and that co-expression of chaperones as well as lysis buffer optimization can increase this ratio. We have applied the identified preferred conditions to Reversibly Glycosylated Polypeptide 1 from Arabidopsis thaliana, and processed this enzyme to near-purity in unprecedented milligram amounts. The obtained preparation of Reversibly Glycosylated Polypeptide 1 has the expected arabinopyranose mutase and autoglycosylation activities.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.« less

Plant cell wall glycosyltransferases: High-throughput recombinant expression screening and general requirements for these challenging enzymes

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

Welner, Ditte Hededam; Shin, David; Tomaleri, Giovani P.

Molecular characterization of plant cell wall glycosyltransferases is a critical step towards understanding the biosynthesis of the complex plant cell wall, and ultimately for efficient engineering of biofuel and agricultural crops. The majority of these enzymes have proven very difficult to obtain in the needed amount and purity for such molecular studies, and recombinant cell wall glycosyltransferase production efforts have largely failed. A daunting number of strategies can be employed to overcome this challenge, including optimization of DNA and protein sequences, choice of expression organism, expression conditions, coexpression partners, purification methods, and optimization of protein solubility and stability. Hence researchersmore » are presented with thousands of potential conditions to test. Ultimately, the subset of conditions that will be sampled depends on practical considerations and prior knowledge of the enzyme(s) being studied. We have developed a rational approach to this process. We devise a pipeline comprising in silico selection of targets and construct design, and high-throughput expression screening, target enrichment, and hit identification. We have applied this pipeline to a test set of Arabidopsis thaliana cell wall glycosyltransferases known to be challenging to obtain in soluble form, as well as to a library of cell wall glycosyltransferases from other plants including agricultural and biofuel crops. The screening results suggest that recombinant cell wall glycosyltransferases in general have a very low soluble: Insoluble ratio in lysates from heterologous expression cultures, and that co-expression of chaperones as well as lysis buffer optimization can increase this ratio. We have applied the identified preferred conditions to Reversibly Glycosylated Polypeptide 1 from Arabidopsis thaliana, and processed this enzyme to near-purity in unprecedented milligram amounts. The obtained preparation of Reversibly Glycosylated Polypeptide 1 has the expected arabinopyranose mutase and autoglycosylation activities.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.« less

Screen test for cadmium and nickel plates as developed and used within the Aerospace Corporation

NASA Technical Reports Server (NTRS)

Phan, A. H.; Zimmerman, A. H.

1994-01-01

A new procedure described here was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

Early Psoriatic Arthritis.

PubMed

McHugh, Neil John

2015-11-01

Skin psoriasis is a major risk factor for the development of psoriatic arthritis. Recent studies have shown that delayed diagnosis is associated with long-term adverse outcomes. Screening questionnaires have revealed a potential burden of undiagnosed disease. Lifestyle factors and genetic and soluble biomarkers have come under scrutiny as risk factors. Imaging modalities may have an important role in detecting early change. With more effective treatments, it may be possible to prevent significant joint damage and associated disability. However, the precise nature of accurate and cost-effective screening strategies remains to be determined. Copyright © 2015 Elsevier Inc. All rights reserved.

Advantages of Crystallographic Fragment Screening: Functional and Mechanistic Insights from a Powerful Platform for Efficient Drug Discovery

PubMed Central

Patel, Disha; Bauman, Joseph D.; Arnold, Eddy

2015-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this “chemical interrogation” of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. PMID:25117499

Advantages of crystallographic fragment screening: functional and mechanistic insights from a powerful platform for efficient drug discovery.

PubMed

Patel, Disha; Bauman, Joseph D; Arnold, Eddy

2014-01-01

X-ray crystallography has been an under-appreciated screening tool for fragment-based drug discovery due to the perception of low throughput and technical difficulty. Investigators in industry and academia have overcome these challenges by taking advantage of key factors that contribute to a successful crystallographic screening campaign. Efficient cocktail design and soaking methodologies have evolved to maximize throughput while minimizing false positives/negatives. In addition, technical improvements at synchrotron beamlines have dramatically increased data collection rates thus enabling screening on a timescale comparable to other techniques. The combination of available resources and efficient experimental design has resulted in many successful crystallographic screening campaigns. The three-dimensional crystal structure of the bound fragment complexed to its target, a direct result of the screening effort, enables structure-based drug design while revealing insights regarding protein dynamics and function not readily obtained through other experimental approaches. Furthermore, this "chemical interrogation" of the target protein crystals can lead to the identification of useful reagents for improving diffraction resolution or compound solubility. Copyright © 2014. Published by Elsevier Ltd.

Social networks as predictors of colorectal cancer screening in African Americans.

PubMed

Alema-Mensah, Ernest; Smith, Selina A; Claridy, Mechelle; Ede, Victor; Ansa, Benjamin; Blumenthal, Daniel S

2017-01-01

Early detection can reduce colorectal cancer (CRC) mortality by 15%-33%, and screening is widely recommended for average-risk adults beginning at age 50 years. Colorectal cancer mortality rates are higher in African Americans than in whites, while screening rates are somewhat lower. Individual social networks can reduce emotional and/or logistical barriers to health-promoting but distasteful procedures such as CRC screening. The aim of this study was to examine social network interactions, and their impact on CRC screening among African Americans. We hypothesized a positive association between social network index (SNI) scores and CRC screening. In a community intervention trial with four arms, we previously demonstrated the efficacy of a small group educational intervention to promote CRC screening among African Americans. This intervention outperformed a one-on-one educational intervention, a reduced out-of-pocket expense intervention, and a control condition. In the present analysis, we compared the SNI scores for participants in the small group intervention cohort with a comparison group comprised of the other three cohorts. Social networks were assessed using the Social Network Index developed by Cohen. Small group participants had a significantly higher network diversity score (Mean difference 0.71; 95% CI, 0.12-1.31; p=0.0017) than the comparison group. In the second component of the SNI score - the number of people talked to over a two week period - the small group intervention cohort also scored significantly higher than the comparison group. (Mean difference, 9.29; 95% CI, 3.963-14.6266; p=0.0004). The findings suggest that social interaction and support was at least partially responsible for the relatively high post-intervention screening rate in the small group intervention participants. Education in small groups could foster strong social networks. Strong and positive network diversity and a large number of people in social networks may enhance CRC screening rates among African Americans.

Selective fluorescent detection of aspartic acid and glutamic acid employing dansyl hydrazine dextran conjugate.

PubMed

Nasomphan, Weerachai; Tangboriboonrat, Pramuan; Tanapongpipat, Sutipa; Smanmoo, Srung

2014-01-01

Highly water soluble polymer (DD) was prepared and evaluated for its fluorescence response towards various amino acids. The polymer consists of dansyl hydrazine unit conjugated into dextran template. The conjugation enhances higher water solubility of dansyl hydrazine moiety. Of screened amino acids, DD exhibited selective fluorescence quenching in the presence of aspartic acid (Asp) and glutamic acid (Glu). A plot of fluorescence intensity change of DD against the concentration of corresponding amino acids gave a good linear relationship in the range of 1 × 10(-4) M to 25 × 10(-3) M. This establishes DD as a potential polymeric sensor for selective sensing of Asp and Glu.

The role of carbon solubility in Fe-C nano-clusters on the growth of small single-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Curtarolo, Stefano; Awasthy, Neha; Setyawan, Wahyu; Mora, Elena; Tokune, Toshio; Bolton, Kim; Harutyunyan, Avetik

2008-03-01

Various diameters of alumina-supported Fe catalysts are used to grow single-walled carbon nanotubes (SWCNTs) with chemical vapor decomposition. We find that the reduction of the catalyst size requires an increase of the minimum temperature necessary for the growth. We address this phenomenon in terms of solubility of C in Fe nanoclusters and, by using first principles calculations, we devise a simple model to predict the behavior of the phases competing for stability in Fe-C nanoclusters at low temperature. We show that, as a function particles size, there are three scenarios compatible with steady state-, limited- and no-growth of SWCNTs, corresponding to unaffected, reduced and no solubility of C in the particles. The result raises previously unknown concerns about the growth feasibility of small and very-long SWCNTs within the current Fe CVD technology, and suggests new strategies in the search of better catalysts. Research supported by Honda R.I. and NSF.

Screensaver: an open source lab information management system (LIMS) for high throughput screening facilities

PubMed Central

2010-01-01

Background Shared-usage high throughput screening (HTS) facilities are becoming more common in academe as large-scale small molecule and genome-scale RNAi screening strategies are adopted for basic research purposes. These shared facilities require a unique informatics infrastructure that must not only provide access to and analysis of screening data, but must also manage the administrative and technical challenges associated with conducting numerous, interleaved screening efforts run by multiple independent research groups. Results We have developed Screensaver, a free, open source, web-based lab information management system (LIMS), to address the informatics needs of our small molecule and RNAi screening facility. Screensaver supports the storage and comparison of screening data sets, as well as the management of information about screens, screeners, libraries, and laboratory work requests. To our knowledge, Screensaver is one of the first applications to support the storage and analysis of data from both genome-scale RNAi screening projects and small molecule screening projects. Conclusions The informatics and administrative needs of an HTS facility may be best managed by a single, integrated, web-accessible application such as Screensaver. Screensaver has proven useful in meeting the requirements of the ICCB-Longwood/NSRB Screening Facility at Harvard Medical School, and has provided similar benefits to other HTS facilities. PMID:20482787

Screensaver: an open source lab information management system (LIMS) for high throughput screening facilities.

PubMed

Tolopko, Andrew N; Sullivan, John P; Erickson, Sean D; Wrobel, David; Chiang, Su L; Rudnicki, Katrina; Rudnicki, Stewart; Nale, Jennifer; Selfors, Laura M; Greenhouse, Dara; Muhlich, Jeremy L; Shamu, Caroline E

2010-05-18

Shared-usage high throughput screening (HTS) facilities are becoming more common in academe as large-scale small molecule and genome-scale RNAi screening strategies are adopted for basic research purposes. These shared facilities require a unique informatics infrastructure that must not only provide access to and analysis of screening data, but must also manage the administrative and technical challenges associated with conducting numerous, interleaved screening efforts run by multiple independent research groups. We have developed Screensaver, a free, open source, web-based lab information management system (LIMS), to address the informatics needs of our small molecule and RNAi screening facility. Screensaver supports the storage and comparison of screening data sets, as well as the management of information about screens, screeners, libraries, and laboratory work requests. To our knowledge, Screensaver is one of the first applications to support the storage and analysis of data from both genome-scale RNAi screening projects and small molecule screening projects. The informatics and administrative needs of an HTS facility may be best managed by a single, integrated, web-accessible application such as Screensaver. Screensaver has proven useful in meeting the requirements of the ICCB-Longwood/NSRB Screening Facility at Harvard Medical School, and has provided similar benefits to other HTS facilities.

Tank 26F-2F Evaporator Study

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

Adu-Wusu, K.

2012-12-19

Tank 26F supernate sample was sent by Savannah River Remediation to Savannah River National Laboratory for evaporation test to help understand the underlying cause of the recent gravity drain line (GDL) pluggage during operation of the 2F Evaporator system. The supernate sample was characterized prior to the evaporation test. The evaporation test involved boiling the supernate in an open beaker until the density of the concentrate (evaporation product) was between 1.4 to 1.5 g/mL. It was followed by filtering and washing of the precipitated solids with deionized water. The concentrate supernate (or concentrate filtrate), the damp unwashed precipitated solids, andmore » the wash filtrates were characterized. All the precipitated solids dissolved during water washing. A semi-quantitative X-ray diffraction (XRD) analysis on the unwashed precipitated solids revealed their composition. All the compounds with the exception of silica (silicon oxide) are known to be readily soluble in water. Hence, their dissolution during water washing is not unexpected. Even though silica is a sparingly water-soluble compound, its dissolution is also not surprising. This stems from its small fraction in the solids as a whole and also its relative freshness. Assuming similar supernate characteristics, flushing the GDL with water (preferably warm) should facilitate dissolution and removal of future pluggage events as long as build up/aging of the sparingly soluble constituent (silica) is limited. On the other hand, since the amount of silica formed is relatively small, it is quite possible dissolution of the more soluble larger fraction will cause disintegration or fragmentation of the sparingly soluble smaller fraction (that may be embedded in the larger soluble solid mass) and allow its removal via suspension in the flushing water.« less

Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2.

PubMed

Zazo Seco, Celia; Serrão de Castro, Luciana; van Nierop, Josephine W; Morín, Matías; Jhangiani, Shalini; Verver, Eva J J; Schraders, Margit; Maiwald, Nadine; Wesdorp, Mieke; Venselaar, Hanka; Spruijt, Liesbeth; Oostrik, Jaap; Schoots, Jeroen; van Reeuwijk, Jeroen; Lelieveld, Stefan H; Huygen, Patrick L M; Insenser, María; Admiraal, Ronald J C; Pennings, Ronald J E; Hoefsloot, Lies H; Arias-Vásquez, Alejandro; de Ligt, Joep; Yntema, Helger G; Jansen, Joop H; Muzny, Donna M; Huls, Gerwin; van Rossum, Michelle M; Lupski, James R; Moreno-Pelayo, Miguel Angel; Kunst, Henricus P M; Kremer, Hannie

2015-11-05

Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation

PubMed Central

Paluch, Andrew S.; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L.

2015-01-01

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes. PMID:25637996

An expeditious synthesis of imatinib and analogues utilising flow chemistry methods.

PubMed

Hopkin, Mark D; Baxendale, Ian R; Ley, Steven V

2013-03-21

A flow-based route to imatinib, the API of Gleevec, was developed and the general procedure then used to generate a number of analogues which were screened for biological activity against Abl1. The flow synthesis required minimal manual intervention and was achieved despite the poor solubility of many of the reaction components.

Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption.

PubMed

Newby, Danielle; Freitas, Alex A; Ghafourian, Taravat

2015-01-27

Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Low-molecular-weight gelators: elucidating the principles of gelation based on gelator solubility and a cooperative self-assembly model.

PubMed

Hirst, Andrew R; Coates, Ian A; Boucheteau, Thomas R; Miravet, Juan F; Escuder, Beatriu; Castelletto, Valeria; Hamley, Ian W; Smith, David K

2008-07-16

This paper highlights the key role played by solubility in influencing gelation and demonstrates that many facets of the gelation process depend on this vital parameter. In particular, we relate thermal stability ( T gel) and minimum gelation concentration (MGC) values of small-molecule gelation in terms of the solubility and cooperative self-assembly of gelator building blocks. By employing a van't Hoff analysis of solubility data, determined from simple NMR measurements, we are able to generate T calc values that reflect the calculated temperature for complete solubilization of the networked gelator. The concentration dependence of T calc allows the previously difficult to rationalize "plateau-region" thermal stability values to be elucidated in terms of gelator molecular design. This is demonstrated for a family of four gelators with lysine units attached to each end of an aliphatic diamine, with different peripheral groups (Z or Boc) in different locations on the periphery of the molecule. By tuning the peripheral protecting groups of the gelators, the solubility of the system is modified, which in turn controls the saturation point of the system and hence controls the concentration at which network formation takes place. We report that the critical concentration ( C crit) of gelator incorporated into the solid-phase sample-spanning network within the gel is invariant of gelator structural design. However, because some systems have higher solubilities, they are less effective gelators and require the application of higher total concentrations to achieve gelation, hence shedding light on the role of the MGC parameter in gelation. Furthermore, gelator structural design also modulates the level of cooperative self-assembly through solubility effects, as determined by applying a cooperative binding model to NMR data. Finally, the effect of gelator chemical design on the spatial organization of the networked gelator was probed by small-angle neutron and X-ray scattering (SANS/SAXS) on the native gel, and a tentative self-assembly model was proposed.

A study on the inhibitory mechanism for cholesterol absorption by α-cyclodextrin administration

PubMed Central

Furune, Takahiro; Ikuta, Naoko; Ishida, Yoshiyuki; Okamoto, Hinako; Nakata, Daisuke; Terao, Keiji

2014-01-01

Summary Background: Micelle formation of cholesterol with lecithin and bile salts is a key process for intestinal absorption of lipids. Some dietary fibers commonly used to reduce the lipid content in the body are thought to inhibit lipid absorption by binding to bile salts and decreasing the lipid solubility. Amongst these, α-cyclodextrin (α-CD) is reportedly one of the most powerful dietary fibers for decreasing blood cholesterol. However, it is difficult to believe that α-CD directly removes cholesterol because it has a very low affinity for cholesterol and its mechanism of action is less well understood than those of other dietary fibers. To identify this mechanism, we investigated the interaction of α-CD with lecithin and bile salts, which are essential components for the dissolution of cholesterol in the small intestine, and the effect of α-CD on micellar solubility of cholesterol. Results: α-CD was added to Fed-State Simulated Intestinal Fluid (FeSSIF), and precipitation of a white solid was observed. Analytical data showed that the precipitate was a lecithin and α-CD complex with a molar ratio of 1:4 or 1:5. The micellar solubility of cholesterol in the mixture of FeSSIF and α-CD was investigated, and found to decrease through lecithin precipitation caused by the addition of α-CD, in a dose-dependent manner. Furthermore, each of several other water-soluble dietary fibers was added to the FeSSIF, and no precipitate was generated. Conclusion: This study suggests that α-CD decreases the micellar solubility of cholesterol in the lumen of the small intestine via the precipitation of lecithin from bile salt micelles by complex formation with α-CD. It further indicates that the lecithin precipitation effect on the bile salt micelles by α-CD addition clearly differs from addition of other water-soluble dietary fibers. The decrease in micellar cholesterol solubility in the FeSSIF was the strongest with α-CD addition. PMID:25550749

High-throughput screening based on label-free detection of small molecule microarrays

NASA Astrophysics Data System (ADS)

Zhu, Chenggang; Fei, Yiyan; Zhu, Xiangdong

2017-02-01

Based on small-molecule microarrays (SMMs) and oblique-incidence reflectivity difference (OI-RD) scanner, we have developed a novel high-throughput drug preliminary screening platform based on label-free monitoring of direct interactions between target proteins and immobilized small molecules. The screening platform is especially attractive for screening compounds against targets of unknown function and/or structure that are not compatible with functional assay development. In this screening platform, OI-RD scanner serves as a label-free detection instrument which is able to monitor about 15,000 biomolecular interactions in a single experiment without the need to label any biomolecule. Besides, SMMs serves as a novel format for high-throughput screening by immobilization of tens of thousands of different compounds on a single phenyl-isocyanate functionalized glass slide. Based on the high-throughput screening platform, we sequentially screened five target proteins (purified target proteins or cell lysate containing target protein) in high-throughput and label-free mode. We found hits for respective target protein and the inhibition effects for some hits were confirmed by following functional assays. Compared to traditional high-throughput screening assay, the novel high-throughput screening platform has many advantages, including minimal sample consumption, minimal distortion of interactions through label-free detection, multi-target screening analysis, which has a great potential to be a complementary screening platform in the field of drug discovery.

Solid dispersions: a strategy for poorly aqueous soluble drugs and technology updates.

PubMed

Alam, Mohd Aftab; Ali, Raisuddin; Al-Jenoobi, Fahad Ibrahim; Al-Mohizea, Abdullah M

2012-11-01

Present article reviews solid dispersion (SD) technologies and other patented inventions in the area of pharmaceutical SDs, which provide stable amorphous SDs. The review briefly compiles different techniques for preparing SDs, their applications, characterization of SDs, types of SDs and also elaborates the carriers used to prepare SDs. The advantages of recently introduced SD technologies such as RightSize(™), closed-cycle spray drying (CSD), Lidose® are summarized. Stability-related issues like phase separation, re-crystallization and methods to curb these problems are also discussed. A patented carrier-screening tool for predicting physical stability of SDs on the basis of drug-carrier interaction is explained. Applications of SD technique in controlled drug delivery systems and cosmetics are explored. Review also summarizes the carriers such as Soluplus®, Neusilin®, Solumer(TM) used to prepare stable amorphous SD. Binary and ternary SDs are found to be more stable and provide better enhancement of solubility or dissolution of poorly water-soluble drugs. The use of surfactants in the carrier system of SD is a recent trend. Surfactants and polymers provide stability against re-crystallization of SDs, surfactants also improve solubility and dissolution of drug.

A Comparison of the effectiveness of Mammographic Film-Screen and Standard Film-Screen in the Detection of Small Bone Fractures

PubMed Central

Sani, Karim Ghazikhanlou; Jafari, Mahmoodreza; Rostampoor, Nima

2011-01-01

The use of mammography film-screen is limited in general radiography. The purpose of this study was to compare the effectiveness of mammographic film-screen and standard film-screen systems in the detection of small bone fractures. Radiographs were taken from patients' extremities and neck areas using mammography film-screen and standard film-screen (n=57 each). Fourteen other radiographs were taken from other views (predominantly oblique views), making a total number of 128 radiographs. Paired radiographs, taken from the same areas, were compared by two radiologists in terms of image visual sharpness, presence of bony fractures, and soft tissue injuries. The surface dose received by patients in the two systems was also compared. The radiographs taken by mammography film-screen had a statistically better visual sharpness compared to those taken by the standard film-screen system. However, there was no statistically significant difference between the diagnostic accuracy of the two systems. Mammography film-screen was able to detect only one out of 57 lesions, whereas standard film-screen system did not detec any lesion. The surface dose received by patients in mammography film-screen was higher than that in standard film-screen system. The findings of the present study suggest that mammography film-screen may be recommended as a diagnostic tool for the detection of small fractures of tinny parts of body such as fingers, hand or foot. They also suggest that mammography film-screen has no advantage over standard film-screen for radiography of thick body parts such as neck and knee. PMID:23115417

The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities.

PubMed

Kurnia, Kiki A; Sintra, Tânia E; Neves, Catarina M S S; Shimizu, Karina; Canongia Lopes, José N; Gonçalves, Fernando; Ventura, Sónia P M; Freire, Mara G; Santos, Luís M N B F; Coutinho, João A P

2014-10-07

The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs.

Influence of matching solubility parameter of polymer matrix and CNT on electrical conductivity of CNT/rubber composite

PubMed Central

Ata, Seisuke; Mizuno, Takaaki; Nishizawa, Ayumi; Subramaniam, Chandramouli; Futaba, Don N.; Hata, Kenji

2014-01-01

We report a general approach to fabricate elastomeric composites possessing high electrical conductivity for applications ranging from wireless charging interfaces to stretchable electronics. By using arbitrary nine kinds of rubbers as matrices, we experimentally demonstrate that the matching the solubility parameter of CNTs and the rubber matrix is important to achieve higher electrical conductivity in CNT/rubber composite, resulting in continuous conductive pathways leading to electrical conductivities as high as 15 S/cm with 10 vol% CNT in fluorinated rubber. Further, using thermodynamic considerations, we demonstrate an approach to mix CNTs to arbitrary rubber matrices regardless of solubility parameter of matrices by adding small amounts of fluorinated rubber as a polymeric-compatibilizer of CNTs. We thereby achieved electrical conductivities ranging from 1.2 to 13.8 S/cm (10 vol% CNTs) using nine varieties of rubber matrices differing in chemical structures and physical properties. Finally, we investigated the components of solubility parameter of CNT by using Hansen solubility parameters, these findings may useful for controlling solubility parameter of CNTs. PMID:25434701

Curcumin loaded nano globules for solubility enhancement: preparation, characterization and ex vivo release study.

PubMed

Kumar, Anil; Ahuja, Alka; Ali, Javed; Baboota, Sanjula

2012-11-01

Curcumin in spite of being an effective chemotherapeutic agent against different type of cancer, suffer from the problem of low systemic bioavailability due to low aqueous solubility, extensive intestinal metabolism and first-pass metabolism when administered via the oral route. The aim of present investigation was to evaluate the potential of nano globules based nanoemulsion formulation for the solubility enhancement of curcumin. The nano globules based formulation was developed using Labrafac Lipophile WL 1349, Unitop FFT 40, PEG 400 and distilled water as an oil, surfactant, co-surfactant and aqueous phase respectively using aqueous titration method. Furthermore, different formulations were subjected to physical stability and consequently evaluated for ex vivo permeation using small intestine. The optimized formulation had small average globule diameter of 58 nm with zeta potential of -32 mv which indicated long-term dispersion stability. The globules were spherical in shape as observed by Transmission electron microscopy. During ex vivo study, the release of curcumin from nanoemulsion was 96.21% and 98.1% in 6 h and 12 h respectively whereas CU suspension was release up to 28.2% at the end of 12 h. This indicated the enhancement of solubility of curcumin in aqueous solution which is the rate limiting step in the absorption of curcumin in the intestine.

High Throughput, Label-free Screening Small Molecule Compound Libraries for Protein-Ligands using Combination of Small Molecule Microarrays and a Special Ellipsometry-based Optical Scanner.

PubMed

Landry, James P; Fei, Yiyan; Zhu, X D

2011-12-01

Small-molecule compounds remain the major source of therapeutic and preventative drugs. Developing new drugs against a protein target often requires screening large collections of compounds with diverse structures for ligands or ligand fragments that exhibit sufficiently affinity and desirable inhibition effect on the target before further optimization and development. Since the number of small molecule compounds is large, high-throughput screening (HTS) methods are needed. Small-molecule microarrays (SMM) on a solid support in combination with a suitable binding assay form a viable HTS platform. We demonstrate that by combining an oblique-incidence reflectivity difference optical scanner with SMM we can screen 10,000 small-molecule compounds on a single glass slide for protein ligands without fluorescence labeling. Furthermore using such a label-free assay platform we can simultaneously acquire binding curves of a solution-phase protein to over 10,000 immobilized compounds, thus enabling full characterization of protein-ligand interactions over a wide range of affinity constants.

Enzymatic Synthesis of Lignin-Based Concrete Dispersing Agents.

PubMed

Jankowska, Dagmara; Heck, Tobias; Schubert, Mark; Yerlikaya, Alpaslan; Weymuth, Christophe; Rentsch, Daniel; Schober, Irene; Richter, Michael

2018-03-15

Lignin is the most abundant aromatic biopolymer, functioning as an integral component of woody materials. In its unmodified form it shows limited water solubility and is relatively unreactive, so biotechnological lignin valorisation for high-performance applications is greatly underexploited. Lignin can be obtained from the pulp and paper industry as a by-product. To expand its application, a new synthesis route to new dispersing agents for use as concrete additives was developed. The route is based on lignin functionalisation by enzymatic transformation. Screening of lignin-modifying systems resulted in functionalised lignin polymers with improved solubility in aqueous systems. Through grafting of sulfanilic acid or p-aminobenzoic acid by fungal laccases, lignin became soluble in water at pH≤4 or pH≤7, respectively. Products were analysed and evaluated in miniaturised application tests in cement paste and mortar. Their dispersing properties match the performance criteria of commercially available lignosulfonates. The study provides examples of new perspectives for the use of lignin. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, screening, and nanocrystals preparation of rhein amide derivatives.

PubMed

Chen, Lijiang; Zhang, Jinfeng; Rong, Jinghong; Liu, Yu; Zhao, Jinhua; Cui, Qingguo; Wang, Xin; Liang, Xiao; Pan, Hao; Liu, Hongsheng

2018-04-23

Rhein (RH) have many bioactivities, but the application was limited of its poor solubility. The present study aimed to establish an efficient method for the synthesis of rhein amide derivatives (RAD) to increase the solubility and anti-tumor activity. RAD exhibited stronger anti-tumor activity than RH in MTT assay. The solubility and oil/water partition coefficient results indicated that rhein-phenylalanine and rhein-isoleucine have better absorption effect, which was consolidated in pharmacokinetic study. Then, rhein-phenylalanine and rhein-isoleucine were prepared into nanocrystals via the precipitation-high pressure homogenization method. Additionally, the nanocrystals both displayed much higher dissolution profiles than the bulk drugs. Pharmacokinetics study indicated that the AUC 0-∞ and C max of nanocrystals increased markedly (p < 0.01). However, the concentration of RH-Phe-NC was far less than RH-Ile-NC in plasma. Consequently, RH-Ile-NC was validated to be an applicable way to improve the bioavailability of RH, which owns a promising future in clinical application.

Wheat germ cell-free expression: Two detergents with a low critical micelle concentration allow for production of soluble HCV membrane proteins.

PubMed

Fogeron, Marie-Laure; Badillo, Aurélie; Jirasko, Vlastimil; Gouttenoire, Jérôme; Paul, David; Lancien, Loick; Moradpour, Darius; Bartenschlager, Ralf; Meier, Beat H; Penin, François; Böckmann, Anja

2015-01-01

Membrane proteins are notoriously difficult to express in a soluble form. Here, we use wheat germ cell-free expression in the presence of various detergents to produce the non-structural membrane proteins 2, 4B and 5A of the hepatitis C virus (HCV). We show that lauryl maltose neopentyl glycol (MNG-3) and dodecyl octaethylene glycol ether (C12E8) detergents can yield essentially soluble membrane proteins at detergent concentrations that do not inhibit the cell-free reaction. This finding can be explained by the low critical micelle concentration (CMC) of these detergents, which keeps the monomer concentrations low while at the same time providing the necessary excess of detergent concentration above CMC required for full target protein solubilization. We estimate that a tenfold excess of detergent micelles with respect to the protein concentration is sufficient for solubilization, a number that we propose as a guideline for detergent screening assays. Copyright © 2014 Elsevier Inc. All rights reserved.

Modification of physicochemical characteristics of active pharmaceutical ingredients and application of supersaturatable dosage forms for improving bioavailability of poorly absorbed drugs.

PubMed

Kawakami, Kohsaku

2012-05-01

New chemical entities are required to possess physicochemical characteristics that result in acceptable oral absorption. However, many promising candidates need physicochemical modification or application of special formulation technology. This review discusses strategies for overcoming physicochemical problems during the development at the preformulation and formulation stages with emphasis on overcoming the most typical problem, low solubility. Solubility of active pharmaceutical ingredients can be improved by employing metastable states, salt forms, or cocrystals. Since the usefulness of salt forms is well recognized, it is the normal strategy to select the most suitable salt form through extensive screening in the current developmental study. Promising formulation technologies used to overcome the low solubility problem include liquid-filled capsules, self-emulsifying formulations, solid dispersions, and nanosuspensions. Current knowledge for each formulation is discussed from both theoretical and practical viewpoints, and their advantages and disadvantages are presented. Copyright © 2012 Elsevier B.V. All rights reserved.

Potent and Selective Amidopyrazole Inhibitors of IRAK4 That Are Efficacious in a Rodent Model of Inflammation

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

McElroy, William T.; Tan, Zheng; Ho, Ginny

IRAK4 is a critical upstream kinase in the IL-1R/TLR signaling pathway. Inhibition of IRAK4 is hypothesized to be beneficial in the treatment of autoimmune related disorders. A screening campaign identified a pyrazole class of IRAK4 inhibitors that were determined by X-ray crystallography to exhibit an unusual binding mode. SAR efforts focused on the identification of a potent and selective inhibitor with good aqueous solubility and rodent pharmacokinetics. Pyrazole C-3 piperidines were well tolerated, with N-sulfonyl analogues generally having good rodent oral exposure but poor solubility. N-Alkyl piperidines exhibited excellent solubility and reduced exposure. Pyrazoles possessing N-1 pyridine and fluorophenyl substituentsmore » were among the most active. Piperazine 32 was a potent enzyme inhibitor with good cellular activity. Compound 32 reduced the in vivo production of proinflammatory cytokines and was orally efficacious in a mouse antibody induced arthritis disease model of inflammation.« less

Creation of a small high-throughput screening facility.

PubMed

Flak, Tod

2009-01-01

The creation of a high-throughput screening facility within an organization is a difficult task, requiring a substantial investment of time, money, and organizational effort. Major issues to consider include the selection of equipment, the establishment of data analysis methodologies, and the formation of a group having the necessary competencies. If done properly, it is possible to build a screening system in incremental steps, adding new pieces of equipment and data analysis modules as the need grows. Based upon our experience with the creation of a small screening service, we present some guidelines to consider in planning a screening facility.

Candidate Herbaceous Plants for Phytoremediation of Energetics on Ranges. Strategic Environmental Research and Development Program

DTIC Science & Technology

2007-09-01

16 Senecio sp. Groundsel yes P medium medium E AK Ft. Greely 6 Sida spinosa Prickly sida A small medium N&S 16 ER D C TR -07-11 11...small C4, CAM N&S Sida spinosa Prickly sida Malvaceae A small medium many considerable C3 N&S 1 Screened for explosives tolerance. 2 A, annual; P...Portulaca oleracea, and h. Sida spinosa. ERDC TR-07-11 16 3 Short-Term Screening for Energetics Tolerance Introduction Short-term screening

DG-AMMOS: a new tool to generate 3d conformation of small molecules using distance geometry and automated molecular mechanics optimization for in silico screening.

PubMed

Lagorce, David; Pencheva, Tania; Villoutreix, Bruno O; Miteva, Maria A

2009-11-13

Discovery of new bioactive molecules that could enter drug discovery programs or that could serve as chemical probes is a very complex and costly endeavor. Structure-based and ligand-based in silico screening approaches are nowadays extensively used to complement experimental screening approaches in order to increase the effectiveness of the process and facilitating the screening of thousands or millions of small molecules against a biomolecular target. Both in silico screening methods require as input a suitable chemical compound collection and most often the 3D structure of the small molecules has to be generated since compounds are usually delivered in 1D SMILES, CANSMILES or in 2D SDF formats. Here, we describe the new open source program DG-AMMOS which allows the generation of the 3D conformation of small molecules using Distance Geometry and their energy minimization via Automated Molecular Mechanics Optimization. The program is validated on the Astex dataset, the ChemBridge Diversity database and on a number of small molecules with known crystal structures extracted from the Cambridge Structural Database. A comparison with the free program Balloon and the well-known commercial program Omega generating the 3D of small molecules is carried out. The results show that the new free program DG-AMMOS is a very efficient 3D structure generator engine. DG-AMMOS provides fast, automated and reliable access to the generation of 3D conformation of small molecules and facilitates the preparation of a compound collection prior to high-throughput virtual screening computations. The validation of DG-AMMOS on several different datasets proves that generated structures are generally of equal quality or sometimes better than structures obtained by other tested methods.

Maternal serum soluble fms-like tyrosine kinase-1 at 12, 22, 32 and 36 weeks' gestation in screening for pre-eclampsia.

PubMed

Tsiakkas, A; Mendez, O; Wright, A; Wright, D; Nicolaides, K H

2016-04-01

To examine the distribution of maternal serum soluble fms-like tyrosine kinase-1 (sFlt-1) at 12, 22, 32 and 36 weeks' gestation in singleton pregnancies that develop pre-eclampsia (PE) and examine the performance of this biomarker in screening for PE. Serum sFlt-1 was measured in 7066 cases at 11-13 weeks, 8079 cases at 19-24 weeks, 8472 at 30-34 weeks and 4043 at 35-37 weeks. Bayes' theorem was used to combine the a-priori risk from maternal characteristics and medical history with serum levels of sFlt-1. The performance of screening for PE in women requiring delivery < 32, between 32 + 0 and 36 + 6 and ≥ 37 weeks' gestation was estimated. In pregnancies that developed PE, serum sFlt-1 was increased and the separation in multiples of the median (MoM) values from normal was greater with earlier, compared to later, gestational age at which delivery for PE became necessary. In pregnancies that developed PE, the slope of the regression lines of sFlt-1 MoM with gestational age at delivery increased with advancing gestational age at screening. Measurement of sFlt-1 at 11-13 weeks did not improve the prediction of PE achieved by maternal factors alone, sFlt-1 at 19-24 weeks improved the prediction of PE delivering < 37 weeks but not for PE delivering ≥ 37 weeks, sFlt-1 at 30-34 weeks improved the prediction of PE delivering < 37 and PE delivering ≥ 37 weeks and sFlt-1 at 35-37 weeks improved the prediction of PE delivering ≥ 37 weeks. The detection rates (DRs), at a false-positive rate (FPR) of 10%, of PE delivering < 32 weeks were 52% and 65% with screening at 12 and 22 weeks, respectively. The DRs for PE delivering between 32 + 0 and 36 + 6 weeks were 44%, 44% and 93% with screening at 12, 22 and 32 weeks. The DR for PE delivering ≥ 37 weeks were 37%, 37%, 52% and 69% with screening at 12, 22, 32 and 36 weeks, respectively. The performance of combined screening with maternal factors, medical history and serum sFlt-1 is superior for detection of early, compared to late, PE and improves with advancing gestational age at screening. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

High-Throughput RT-PCR for small-molecule screening assays

PubMed Central

Bittker, Joshua A.

2012-01-01

Quantitative measurement of the levels of mRNA expression using real-time reverse transcription polymerase chain reaction (RT-PCR) has long been used for analyzing expression differences in tissue or cell lines of interest. This method has been used somewhat less frequently to measure the changes in gene expression due to perturbagens such as small molecules or siRNA. The availability of new instrumentation for liquid handling and real-time PCR analysis as well as the commercial availability of start-to-finish kits for RT-PCR has enabled the use of this method for high-throughput small-molecule screening on a scale comparable to traditional high-throughput screening (HTS) assays. This protocol focuses on the special considerations necessary for using quantitative RT-PCR as a primary small-molecule screening assay, including the different methods available for mRNA isolation and analysis. PMID:23487248

Octanol-water partition coefficients for predicting the effects of tannins in ruminant nutrition.

PubMed

Mueller-Harvey, Irene; Mlambo, Victor; Sikosana, Joe L N; Smith, Tim; Owen, Emyr; Brown, Ron H

2007-07-11

Tannins can cause beneficial or harmful nutritional effects, but their great diversity has until now prevented a rational distinction between tannin structures and their nutritional responses. An attempt has been made to study this problem by examining the octanol-water solubilities of tannins. A relatively simple HPLC method has been developed for screening mixtures of plant tannins for their octanol-water partition coefficients (Kow coefficients). Tannins were isolated from the fruits and leaves of different Acacia, Calliandra, Dichrostachys, and Piliostigma species, which are known to produce beneficial or harmful effects. The Kow coefficients of these tannins ranged from 0.061 to 13.9, average coefficients of variation were 9.2% and recoveries were 107%. Acacia nilotica fruits and leaves had the highest Kow coefficients, that is, 2.0 and 13.9, respectively. These A. nilotica products also have high concentrations of tannins. The combined effects of high octanol solubilities and high tannin concentrations may explain their negative effects on animal nutrition and health. It is known that compounds with high octanol solubilities are more easily absorbed into tissues, and it is, therefore, proposed that such compounds are more likely to cause toxicity problems especially if consumed in large quantities. According to the literature, tannins in human foods tend to have low Kow coefficients, and this was confirmed for the tannins in Piliostigma thonningii fruits. Therefore, unconventional feeds or browse products should be screened not only for their tannin concentrations but also for low octanol-water partition coefficients in order to identify nutritionally safe feeds and to avoid potentially toxic feeds.

Screening of the chemical reactivity of three different graphite sources using the formation of reductively alkylated graphene as a model reaction.

PubMed

Knirsch, Kathrin C; Englert, Jan M; Dotzer, Christoph; Hauke, Frank; Hirsch, Andreas

2013-11-28

Reductive alkylation of three graphite starting materials G(flake), G(powder), and G(spherical) reveals pronounced differences in the obtained covalently functionalized graphene with respect to the degree of functionalization, exfoliation efficiency and product homogeneity, as demonstrated by statistical Raman microscopy (SRM), TGA/MS, IR-spectroscopy and solubility behavior.

Imaging and Screening of Cancer of the Small Bowel.

PubMed

Kim, Jin Sil; Park, Seong Ho; Hansel, Stephanie; Fletcher, Joel G

2017-11-01

Delayed diagnosis of small bowel cancers frequently occurs and may arise because of many factors, including low incidence of disease, difficult endoscopic access, lack of mucosal mass or abnormality, subtle radiologic features, and low index of clinical suspicion. As small bowel cancers are rare and their causes are largely unknown, routine population-based screening of asymptomatic patients to find precursor lesions or early cancers is ineffective. However, targeted screening/surveillance strategies are used in specific at-risk and symptomatic patient populations. This article reviews issues regarding early diagnosis of small bowel cancers, with focus on state-of-the-art cross-sectional imaging techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

Fluorescence-based high-throughput screening of dicer cleavage activity.

PubMed

Podolska, Katerina; Sedlak, David; Bartunek, Petr; Svoboda, Petr

2014-03-01

Production of small RNAs by ribonuclease III Dicer is a key step in microRNA and RNA interference pathways, which employ Dicer-produced small RNAs as sequence-specific silencing guides. Further studies and manipulations of microRNA and RNA interference pathways would benefit from identification of small-molecule modulators. Here, we report a study of a fluorescence-based in vitro Dicer cleavage assay, which was adapted for high-throughput screening. The kinetic assay can be performed under single-turnover conditions (35 nM substrate and 70 nM Dicer) in a small volume (5 µL), which makes it suitable for high-throughput screening in a 1536-well format. As a proof of principle, a small library of bioactive compounds was analyzed, demonstrating potential of the assay.

Characterization of Sugar Insensitive (sis) Mutants of Arabidopsis

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

Gibson, Susan I.

Despite the fact that soluble sugar levels have been postulated to play an important role in the control of a wide variety of plant metabolic and developmental pathways, the mechanisms by which plants respond to soluble sugar levels remain poorly understood. Plant responses to soluble sugar levels are also important in bioenergy production, as plant sugar responses are believed to help regulate both carbon fixation and carbon partitioning. For example, accumulation of soluble sugars, such as sucrose and glucose, in source tissues leads to feedback inhibition of photosynthesis, thereby decreasing rates of carbon fixation. Soluble sugar levels can also affectmore » sink strengths, affecting the rates of accumulation of carbon-based compounds into both particular molecular forms (e.g. carbohydrates versus lipids versus proteins) and particular plant organs and tissues. Mutants of Arabidopsis that are defective in the ability to respond to soluble sugar levels were isolated and used as tools to identify some of the factors involved in plant sugar response. These sugar insensitive (sis) mutants were isolated by screening mutagenized seeds for those that were able to germinate and develop relatively normal shoot systems on media containing 0.3 M glucose or 0.3 M sucrose. At these sugar concentrations, wild-type Arabidopsis germinate and produce substantial root systems, but show little to no shoot development. Twenty-eight sis mutants were isolated during the course of four independent mutant screens. Based on a preliminary characterization of all of these mutants, sis3 and sis6 were chosen for further study. Both of these mutations appear to lie in previously uncharacterized loci. Unlike many other sugar-response mutants, sis3 mutants exhibit a wild-type or near wild-type response in all phytohormone-response assays conducted to date. The sis6-1 mutation is unusual in that it appears to be due to overexpression of a gene, rather than representing a loss of function mutation. Characterization of mutant and wild-type plants has revealed that sugars inhibit breakdown of seed storage lipids. In addition, high concentrations of exogenous sugars largely eliminate the development of mature chloroplasts by developing seedlings. Affymetrix GeneChip experiments have revealed that expression of many plant genes is partially regulated by sugar levels, with approximately two percent of genes exhibiting alterations in steady-state mRNA levels in response to changing sugar concentrations. Ultimately, a better understanding of plant sugar responses may allow improvements in rates of carbon fixation and manipulation of carbon partitioning. These improvements will be needed to help make production of energy from biomass more economically attractive.« less

Structural insights into binding of inhibitors to soluble epoxide hydrolase gained by fragment screening and X-ray crystallography.

PubMed

Amano, Yasushi; Yamaguchi, Tomohiko; Tanabe, Eiki

2014-04-15

Soluble epoxide hydrolase (sEH) is a component of the arachidonic acid cascade and is a candidate target for therapies for hypertension or inflammation. Although many sEH inhibitors are available, their scaffolds are not structurally diverse, and knowledge of their specific interactions with sEH is limited. To obtain detailed structural information about protein-ligand interactions, we conducted fragment screening of sEH, analyzed the fragments using high-throughput X-ray crystallography, and determined 126 fragment-bound structures at high resolution. Aminothiazole and benzimidazole derivatives were identified as novel scaffolds that bind to the catalytic triad of sEH with good ligand efficiency. We further identified fragment hits that bound to subpockets of sEH called the short and long branches. The water molecule conserved in the structure plays an important role in binding to the long branch, whereas Asp496 and the main chain of Phe497 form hydrogen bonds with fragment hits in the short branch. Fragment hits and their crystal structures provide structural insights into ligand binding to sEH that will facilitate the discovery of novel and potent inhibitors of sEH. Copyright © 2014 Elsevier Ltd. All rights reserved.

Discovery of the first dual inhibitor of the 5-lipoxygenase-activating protein and soluble epoxide hydrolase using pharmacophore-based virtual screening

NASA Astrophysics Data System (ADS)

Temml, Veronika; Garscha, Ulrike; Romp, Erik; Schubert, Gregor; Gerstmeier, Jana; Kutil, Zsofia; Matuszczak, Barbara; Waltenberger, Birgit; Stuppner, Hermann; Werz, Oliver; Schuster, Daniela

2017-02-01

Leukotrienes (LTs) are pro-inflammatory lipid mediators derived from arachidonic acid (AA) with roles in inflammatory and allergic diseases. The biosynthesis of LTs is initiated by transfer of AA via the 5-lipoxygenase-activating protein (FLAP) to 5-lipoxygenase (5-LO). FLAP inhibition abolishes LT formation exerting anti-inflammatory effects. The soluble epoxide hydrolase (sEH) converts AA-derived anti-inflammatory epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatetraenoic acids (di-HETEs). Its inhibition consequently also counteracts inflammation. Targeting both LT biosynthesis and the conversion of EETs with a dual inhibitor of FLAP and sEH may represent a novel, powerful anti-inflammatory strategy. We present a pharmacophore-based virtual screening campaign that led to 20 hit compounds of which 4 targeted FLAP and 4 were sEH inhibitors. Among them, the first dual inhibitor for sEH and FLAP was identified, N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N’-(3,4-dichlorophenyl)urea with IC50 values of 200 nM in a cell-based FLAP test system and 20 nM for sEH activity in a cell-free assay.

A broad pH range indicator-based spectrophotometric assay for true lipases using tributyrin and tricaprylin[S

PubMed Central

Camacho-Ruiz, María de los Angeles; Mateos-Díaz, Juan Carlos; Carrière, Frédéric; Rodriguez, Jorge A.

2015-01-01

A continuous assay is proposed for the screening of acidic, neutral, or alkaline lipases using microtiter plates, emulsified short- and medium-chain TGs, and a pH indicator. The lipase activity measurement is based on the decrease of the pH indicator optical density due to protonation which is caused by the release of FFAs during the hydrolysis of TGs and thus acidification. Purified lipases with distinct pH optima and an esterase were used to validate the method. The rate of lipolysis was found to be linear with time and proportional to the amount of enzyme added in each case. Specific activities measured with this microplate assay method were lower than those obtained by the pH-stat technique. Nevertheless, the pH-dependent profiles of enzymatic activity were similar with both assays. In addition, the substrate preference of each enzyme tested was not modified and this allowed discriminating lipase and esterase activities using tributyrin (low water solubility) and tricaprylin (not water soluble) as substrates. This continuous lipase assay is compatible with a high sample throughput and can be applied for the screening of lipases and lipase inhibitors from biological samples. PMID:25748441

Structure-Based Optimization of Arylamides as Inhibitors of Soluble Epoxide Hydrolase

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

Eldrup, Anne B.; Soleymanzadeh, Fariba; Taylor, Steven J.

2009-11-04

Inhibition of soluble epoxide hydrolase (sEH) is hypothesized to lead to an increase in circulating levels of epoxyeicosatrienoic acids, resulting in the potentiation of their in vivo pharmacological properties. As part of an effort to identify inhibitors of sEH with high and sustained plasma exposure, we recently performed a high throughput screen of our compound collection. The screen identified N-(3,3-diphenyl-propyl)-nicotinamide as a potent inhibitor of sEH. Further profiling of this lead revealed short metabolic half-lives in microsomes and rapid clearance in the rat. Consistent with these observations, the determination of the in vitro metabolic profile of N-(3,3-diphenyl-propyl)-nicotinamide in rat livermore » microsomes revealed extensive oxidative metabolism and a propensity for metabolite switching. Lead optimization, guided by the analysis of the solid-state costructure of N-(3,3-diphenyl-propyl)-nicotinamide bound to human sEH, led to the identification of a class of potent and selective inhibitors. An inhibitor from this class displayed an attractive in vitro metabolic profile and high and sustained plasma exposure in the rat after oral administration.« less

Manganese ore tailing: optimization of acid leaching conditions and recovery of soluble manganese.

PubMed

Santos, Olívia de Souza Heleno; Carvalho, Cornélio de Freitas; Silva, Gilmare Antônia da; Santos, Cláudio Gouvêa Dos

2015-01-01

Manganese recovery from industrial ore processing waste by means of leaching with sulfuric acid was the objective of this study. Experimental conditions were optimized by multivariate experimental design approaches. In order to study the factors affecting leaching, a screening step was used involving a full factorial design with central point for three variables in two levels (2(3)). The three variables studied were leaching time, concentration of sulfuric acid and sample amount. The three factors screened were shown to be relevant and therefore a Doehlert design was applied to determine the best working conditions for leaching and to build the response surface. By applying the best leaching conditions, the concentrations of 12.80 and 13.64 %w/w of manganese for the global sample and for the fraction -44 + 37 μm, respectively, were found. Microbeads of chitosan were tested for removal of leachate acidity and recovering of soluble manganese. Manganese recovery from the leachate was 95.4%. Upon drying the leachate, a solid containing mostly manganese sulfate was obtained, showing that the proposed optimized method is efficient for manganese recovery from ore tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial screening test for lignite degradation. Quarterly progress report No. 3, July 1-September 30, 1985

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

Yen, T.F.

1985-01-01

Degradation of Beulah std No. 3 lignite was carried out by means of cupric oxidation, modified-autoclaved-cupric oxidation, sodium dichromate oxidation, and also by biological methods. Assessment of the yield of alkaline-soluble and methanol soluble products of both cupric oxidation and modified cupric oxidation (on a moisture-free and ash-free basis) was carried out by both ion chromatography and gel permeation chromatography. Fractionation of lignite for natural-uninoculated-biological growth resulted in no growth for both benzene-methanol fraction and alkaline filtrate fraction, whereas that of alkaline geletinous fraction resulted in positive growth of unidentified white-rot fungi. Acclimation of Polyporus versicolor to lignite was attempted.more » 10 refs.« less

Comparison of Task Performance by Students with Autism and Moderate Intellectual Disabilities when Presenting Video Models on Large and Small Screen Sizes

ERIC Educational Resources Information Center

Mechling, Linda C.; Youhouse, Iva R.

2012-01-01

This investigation compared the ability of students with disabilities to complete fine motor tasks when presented with video models on a small personal digital assistant (PDA) screen and a traditional computer laptop screen. Two groups of elementary age students participated in the study: four with moderate intellectual disabilities (Moderate ID),…

An assessment of biodegradability of quaternary carbon-containing fragrance compounds: comparison of experimental OECD screening test results and in silico prediction data.

PubMed

Seyfried, Markus; Boschung, Alain

2014-05-01

An assessment of biodegradability was carried out for fragrance substances containing quaternary carbons by using data obtained from Organisation for Economic Co-operation and Development (OECD) 301F screening tests for ready biodegradation and from Biowin and Catalogic prediction models. Despite an expected challenging profile, a relatively high percentage of common-use fragrance substances showed significant biodegradation under the stringent conditions applied in the OECD 301F test. Among 27 test compounds, 37% met the pass level criteria after 28 d, while another 26% indicated partial breakdown (≥20% biodegradation). For several compounds for which structural analogs were available, the authors found that structures that were rendered less water soluble by either the presence of an acetate ester or the absence of oxygen tended to degrade to a lesser extent compared to the primary alcohols or oxygenated counterparts under the test conditions applied. Difficulties were encountered when attempting to correlate experimental with in silico data. Whereas the Biowin model combinations currently recommended by regulatory agencies did not allow for a reliable discrimination between readily and nonbiodegradable compounds, only a comparably small proportion of the chemicals studied (30% and 63% depending on the model) fell within the applicability domain of Catalogic, a factor that critically reduced its predictive power. According to these results, currently neither Biowin nor Catalogic accurately reflects the potential for biodegradation of fragrance compounds containing quaternary carbons. © 2014 SETAC.

Utilization of banana peel as a novel substrate for biosurfactant production by Halobacteriaceae archaeon AS65.

PubMed

Chooklin, Chanika Saenge; Maneerat, Suppasil; Saimmai, Atipan

2014-05-01

In this study, biosurfactant-producing bacteria was evaluated for biosurfactant production by using banana peel as a sole carbon source. From the 71 strains screened, Halobacteriaceae archaeon AS65 produced the highest biosurfactant activity. The highest biosurfactant production (5.30 g/l) was obtained when the cells were grown on a minimal salt medium containing 35 % (w/v) banana peel and 1 g/l commercial monosodium glutamate at 30 °C and 200 rpm after 54 h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5 mN/m), a small critical micelle concentration value (10 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity, and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test FT-IR, NMR, and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and had the ability to emulsify oil, enhance PAHs solubility, and oil bioremediation.

Oral controlled release optimization of pellets prepared by extrusion-spheronization processing.

PubMed

Bianchini, R; Vecchio, C

1989-06-01

Controlled release high dosage forms of a typical drug such as Indobufen were prepared as multiple-unit doses by employing extrusion-spheronization processing and subsequently film coating operations. The effects of drug particle size, drug/binder ratio, extruder screen size and preparation reproducibility on the physical properties of the spherical granules were evaluated. Controlled release optimization was obtained on the same granules by coating with polymeric membranes of different thickness consisting of water-soluble and insoluble substances. Film coating was applied from an organic solution using pan coating technique. The drug diffusion is allowed by dissolution of part of the membrane leaving small channels of the polymer coat. Further preparations were conducted to evaluate coatings applied from aqueous dispersion (pseudolatex) using air suspension coating technique. In this system the drug diffusion is governed by the intrinsic pore network of the membrane. The most promising preparations having the desired in vitro release, were metered into hard capsules to obtain the drug unit dosage. Accelerated stability tests were carried out to assess the influence of time and the other storage parameters on the drug release profile.

Peptide arrays on cellulose support: SPOT synthesis, a time and cost efficient method for synthesis of large numbers of peptides in a parallel and addressable fashion.

PubMed

Hilpert, Kai; Winkler, Dirk F H; Hancock, Robert E W

2007-01-01

Peptide synthesis on cellulose using SPOT technology allows the parallel synthesis of large numbers of addressable peptides in small amounts. In addition, the cost per peptide is less than 1% of peptides synthesized conventionally on resin. The SPOT method follows standard fluorenyl-methoxy-carbonyl chemistry on conventional cellulose sheets, and can utilize more than 600 different building blocks. The procedure involves three phases: preparation of the cellulose membrane, stepwise coupling of the amino acids and cleavage of the side-chain protection groups. If necessary, peptides can be cleaved from the membrane for assays performed using soluble peptides. These features make this method an excellent tool for screening large numbers of peptides for many different purposes. Potential applications range from simple binding assays, to more sophisticated enzyme assays and studies with living microbes or cells. The time required to complete the protocol depends on the number and length of the peptides. For example, 400 9-mer peptides can be synthesized within 6 days.

Solubility of nitrogen in marine mammal blubber depends on its lipid composition.

PubMed

Koopman, Heather N; Westgate, Andrew J

2012-11-01

Understanding the solubility of nitrogen gas in tissues is a crucial aspect of diving physiology, especially for air-breathing tetrapods. Adipose tissue is of particular interest because of the high solubility of nitrogen in lipids. Surprisingly, nothing is known about nitrogen solubility in the blubber of any marine mammal. We tested the hypothesis that N(2) solubility is dependent on the lipid composition of blubber; most blubber is composed of triacylglycerols, but some toothed whales deposit large amounts of waxes in blubber instead. The solubility of N(2) in the blubber of 13 toothed whale species ranged from 0.062 to 0.107 ml N(2) ml(-1) oil. Blubber with high wax ester content had higher N(2) solubility, observed in the beaked (Ziphiidae) and small sperm (Kogiidae) whales, animals that routinely make long, deep dives. We also measured nitrogen solubility in the specialized cranial acoustic fat bodies associated with echolocation in a Risso's dolphin; values (0.087 ml N(2) ml(-1) oil) were 16% higher here than in its blubber (0.074 ml N(2) ml(-1) oil). As the acoustic fats of all Odontocetes contain waxes, even if the blubber does not, these tissues may experience greater interaction with N(2). These data have implications for our understanding and future modeling of diving physiology in Odontocetes, as our empirically derived values for nitrogen solubility in toothed whale adipose were up to 40% higher than the numbers traditionally assumed in marine mammal diving models.

Enhanced neuroinvasion by smaller, soluble prions.

PubMed

Bett, Cyrus; Lawrence, Jessica; Kurt, Timothy D; Orru, Christina; Aguilar-Calvo, Patricia; Kincaid, Anthony E; Surewicz, Witold K; Caughey, Byron; Wu, Chengbiao; Sigurdson, Christina J

2017-04-21

Infectious prion aggregates can propagate from extraneural sites into the brain with remarkable efficiency, likely transported via peripheral nerves. Yet not all prions spread into the brain, and the physical properties of a prion that is capable of transit within neurons remain unclear. We hypothesized that small, diffusible aggregates spread into the CNS via peripheral nerves. Here we used a structurally diverse panel of prion strains to analyze how the prion conformation impacts transit into the brain. Two prion strains form fibrils visible ultrastructurally in the brain in situ, whereas three strains form diffuse, subfibrillar prion deposits and no visible fibrils. The subfibrillar strains had significantly higher levels of soluble prion aggregates than the fibrillar strains. Primary neurons internalized both the subfibrillar and fibril-forming prion strains by macropinocytosis, and both strain types were transported from the axon terminal to the cell body in vitro. However in mice, only the predominantly soluble, subfibrillar prions, and not the fibrillar prions, were efficiently transported from the tongue to the brain. Sonicating a fibrillar prion strain increased the solubility and enabled prions to spread into the brain in mice, as evident by a 40% increase in the attack rate, indicating that an increase in smaller particles enhances prion neuroinvasion. Our data suggest that the small, highly soluble prion particles have a higher capacity for transport via nerves. These findings help explain how prions that predominantly assemble into subfibrillar states can more effectively traverse into and out of the CNS, and suggest that promoting fibril assembly may slow the neuron-to-neuron spread of protein aggregates.

Solubility of small-chain carboxylic acids in supercritical carbon dioxide

DOE PAGES

Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; ...

2010-07-08

The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m -3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m -3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m -3 (T = 333.15 K,more » p = 10.0 MPa), while the highest solute concentration was (151 ± 2) kg • m -3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.« less

Design of a multi-purpose fragment screening library using molecular complexity and orthogonal diversity metrics

NASA Astrophysics Data System (ADS)

Lau, Wan F.; Withka, Jane M.; Hepworth, David; Magee, Thomas V.; Du, Yuhua J.; Bakken, Gregory A.; Miller, Michael D.; Hendsch, Zachary S.; Thanabal, Venkataraman; Kolodziej, Steve A.; Xing, Li; Hu, Qiyue; Narasimhan, Lakshmi S.; Love, Robert; Charlton, Maura E.; Hughes, Samantha; van Hoorn, Willem P.; Mills, James E.

2011-07-01

Fragment Based Drug Discovery (FBDD) continues to advance as an efficient and alternative screening paradigm for the identification and optimization of novel chemical matter. To enable FBDD across a wide range of pharmaceutical targets, a fragment screening library is required to be chemically diverse and synthetically expandable to enable critical decision making for chemical follow-up and assessing new target druggability. In this manuscript, the Pfizer fragment library design strategy which utilized multiple and orthogonal metrics to incorporate structure, pharmacophore and pharmacological space diversity is described. Appropriate measures of molecular complexity were also employed to maximize the probability of detection of fragment hits using a variety of biophysical and biochemical screening methods. In addition, structural integrity, purity, solubility, fragment and analog availability as well as cost were important considerations in the selection process. Preliminary analysis of primary screening results for 13 targets using NMR Saturation Transfer Difference (STD) indicates the identification of uM-mM hits and the uniqueness of hits at weak binding affinities for these targets.

Design of a multi-purpose fragment screening library using molecular complexity and orthogonal diversity metrics.

PubMed

Lau, Wan F; Withka, Jane M; Hepworth, David; Magee, Thomas V; Du, Yuhua J; Bakken, Gregory A; Miller, Michael D; Hendsch, Zachary S; Thanabal, Venkataraman; Kolodziej, Steve A; Xing, Li; Hu, Qiyue; Narasimhan, Lakshmi S; Love, Robert; Charlton, Maura E; Hughes, Samantha; van Hoorn, Willem P; Mills, James E

2011-07-01

Fragment Based Drug Discovery (FBDD) continues to advance as an efficient and alternative screening paradigm for the identification and optimization of novel chemical matter. To enable FBDD across a wide range of pharmaceutical targets, a fragment screening library is required to be chemically diverse and synthetically expandable to enable critical decision making for chemical follow-up and assessing new target druggability. In this manuscript, the Pfizer fragment library design strategy which utilized multiple and orthogonal metrics to incorporate structure, pharmacophore and pharmacological space diversity is described. Appropriate measures of molecular complexity were also employed to maximize the probability of detection of fragment hits using a variety of biophysical and biochemical screening methods. In addition, structural integrity, purity, solubility, fragment and analog availability as well as cost were important considerations in the selection process. Preliminary analysis of primary screening results for 13 targets using NMR Saturation Transfer Difference (STD) indicates the identification of uM-mM hits and the uniqueness of hits at weak binding affinities for these targets.

Rapid Catalyst Screening by a Continuous-Flow Microreactor Interfaced with Ultra High Pressure Liquid Chromatography

PubMed Central

Fang, Hui; Xiao, Qing; Wu, Fanghui; Floreancig, Paul E.; Weber, Stephen G.

2010-01-01

A high-throughput screening system for homogeneous catalyst discovery has been developed by integrating a continuous-flow capillary-based microreactor with ultra-high pressure liquid chromatography (UHPLC) for fast online analysis. Reactions are conducted in distinct and stable zones in a flow stream that allows for time and temperature regulation. UHPLC detection at high temperature allows high throughput online determination of substrate, product, and byproduct concentrations. We evaluated the efficacies of a series of soluble acid catalysts for an intramolecular Friedel-Crafts addition into an acyliminium ion intermediate within one day and with minimal material investment. The effects of catalyst loading, reaction time, and reaction temperature were also screened. This system exhibited high reproducibility for high-throughput catalyst screening and allowed several acid catalysts for the reaction to be identified. Major side products from the reactions were determined through off-line mass spectrometric detection. Er(OTf)3, the catalyst that showed optimal efficiency in the screening, was shown to be effective at promoting the cyclization reaction on a preparative scale. PMID:20666502

Variable tolerance to copper in two species from San Francisco Bay

USGS Publications Warehouse

Luoma, S.N.; Cain, D.J.; Ho, K.; Hutchinson, A.

1983-01-01

In static toxicity experiments, tolerance to soluble Cu of the bivalve, Macoma balthica, and the copepod, Acartia clausi, varied substantially among populations sampled within San Francisco Bay. Intraspecific tolerance differed ten-fold or more for both species over relatively small distances, suggesting geographical isolation of populations is not a prerequisite for the development of intraspecific differences in tolerance by aquatic organisms.In static toxicity experiments, tolerance to soluble Cu of the bivalve, Macoma balthica, and the copepod, Acartia clausi, varied substantially among populations sampled within San Francisco Bay. Intraspecific tolerance differed ten-fold or more for both species over relatively small distances, suggesting geographical isolation of populations is not a prerequisite for the development of intraspecific differences in tolerance by aquatic organisms. Refs.

A Novel Dual Expression Platform for High Throughput Functional Screening of Phage Libraries in Product like Format.

PubMed

Xiao, Xiaodong; Chen, Yan; Mugabe, Sheila; Gao, Changshou; Tkaczyk, Christine; Mazor, Yariv; Pavlik, Peter; Wu, Herren; Dall'Acqua, William; Chowdhury, Partha Sarathi

2015-01-01

High throughput screenings of single chain Fv (scFv) antibody phage display libraries are currently done as soluble scFvs produced in E.coli. Due to endotoxin contaminations from bacterial cells these preparations cannot be reliably used in mammalian cell based assays. The monovalent nature and lack of Fc in soluble scFvs prevent functional assays that are dependent on target cross linking and/or Fc functions. A convenient approach is to convert scFvs into scFv.Fc fusion proteins and express them in mammalian cell lines for screening. This approach is low throughput and is only taken after primary screening of monovalent scFvs that are expressed in bacteria. There is no platform at present that combines the benefits of both bacterial and mammalian expression system for screening phage library output. We have, therefore, developed a novel dual expression vector, called pSplice, which can be used to express scFv.Fc fusion proteins both in E.coli and mammalian cell lines. The hallmark of the vector is an engineered intron which houses the bacterial promoter and signal peptide for expression and secretion of scFv.Fc in E.coli. When the vector is transfected into a mammalian cell line, the intron is efficiently spliced out resulting in a functional operon for expression and secretion of the scFv.Fc fusion protein into the culture medium. By applying basic knowledge of mammalian introns and splisosome, we designed this vector to enable screening of phage libraries in a product like format. Like IgG, the scFv.Fc fusion protein is bi-valent for the antigen and possesses Fc effector functions. Expression in E.coli maintains the speed of the bacterial expression platform and is used to triage clones based on binding and other assays that are not sensitive to endotoxin. Triaged clones are then expressed in a mammalian cell line without the need for any additional cloning steps. Conditioned media from the mammalian cell line containing the fusion proteins are then used for different types of cell based assays. Thus this system retains the speed of the current screening system for phage libraries and adds additional functionality to it.

Correlation of second virial coefficient with solubility for proteins in salt solutions.

PubMed

Mehta, Chirag M; White, Edward T; Litster, James D

2012-01-01

In this work, osmotic second virial coefficients (B(22)) were determined and correlated with the measured solubilities for the proteins, α-amylase, ovalbumin, and lysozyme. The B(22) values and solubilities were determined in similar solution conditions using two salts, sodium chloride and ammonium sulfate in an acidic pH range. An overall decrease in the solubility of the proteins (salting out) was observed at high concentrations of ammonium sulfate and sodium chloride solutions. However, for α-amylase, salting-in behavior was also observed in low concentration sodium chloride solutions. In ammonium sulfate solutions, the B(22) are small and close to zero below 2.4 M. As the ammonium sulfate concentrations were further increased, B(22) values decreased for all systems studied. The effect of sodium chloride on B(22) varies with concentration, solution pH, and the type of protein studied. Theoretical models show a reasonable fit to the experimental derived data of B(22) and solubility. B(22) is also directly proportional to the logarithm of the solubility values for individual proteins in salt solutions, so the log-linear empirical models developed in this work can also be used to rapidly predict solubility and B(22) values for given protein-salt systems. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Improved aqueous scrubber for collection of soluble atmospheric trace gases

NASA Technical Reports Server (NTRS)

Cofer, W. R., III; Talbot, R. W.; Collins, V. G.

1985-01-01

A new concentration technique for the extraction and enrichment of water-soluble atmospheric trace gases has been developed. The gas scrubbing technique efficiently extracts soluble gases from a large volume flow rate of air sample into a small volume of refluxed trapping solution. The gas scrubber utilizes a small nebulizing nozzle that mixes the incoming air with an aqueous extracting solution to form an air/droplet mist. The mist provides excellent interfacial surface areas for mass transfer. The resulting mist sprays upward through the reaction chamber until it impinges upon a hydrophobic membrane that virtually blocks the passage of droplets but offers little resistance to the existing gas flow. Droplets containing the scrubbed gases coalesce on the membrane and drip back into the reservoir for further refluxing. After a suitable concentration period, the extracting solution containing the analyte can be withdrawn for analysis. The nebulization-reflex concentration technique is more efficient (maximum flow of gas through the minimum volume of extractant) than conventional bubbler/impinger gas extraction techniques and is offered as an alternative method.

Theory for solubility in static systems

NASA Astrophysics Data System (ADS)

Gusev, Andrei A.; Suter, Ulrich W.

1991-06-01

A theory for the solubility of small particles in static structures has been developed. The distribution function of the solute in a frozen solid has been derived in analytical form for the quantum and the quasiclassical cases. The solubility at infinitesimal gas pressure (Henry's constant) as well as the pressure dependence of the solute concentration at elevated pressures has been found from the statistical equilibrium between the solute in the static matrix and the ideal-gas phase. The distribution function of a solute containing different particles has been evaluated in closed form. An application of the theory to the sorption of methane in the computed structures of glassy polycarbonate has resulted in a satisfactory agreement with experimental data.

Dockres: a computer program that analyzes the output of virtual screening of small molecules

PubMed Central

2010-01-01

Background This paper describes a computer program named Dockres that is designed to analyze and summarize results of virtual screening of small molecules. The program is supplemented with utilities that support the screening process. Foremost among these utilities are scripts that run the virtual screening of a chemical library on a large number of processors in parallel. Methods Dockres and some of its supporting utilities are written Fortran-77; other utilities are written as C-shell scripts. They support the parallel execution of the screening. The current implementation of the program handles virtual screening with Autodock-3 and Autodock-4, but can be extended to work with the output of other programs. Results Analysis of virtual screening by Dockres led to both active and selective lead compounds. Conclusions Analysis of virtual screening was facilitated and enhanced by Dockres in both the authors' laboratories as well as laboratories elsewhere. PMID:20205801

Method for enhancing the solubility of dopants in silicon

DOEpatents

Sadigh, Babak; Lenosky, Thomas J.; De La Rubia, Tomas Diaz

2003-09-30

A method for enhancing the equilibrium solid solubility of dopants in silicon, germanium and silicon-germanium alloys. The method involves subjecting silicon-based substrate to biaxial or compression strain. It has been determined that boron solubility was largely enhanced (more than 100%) by a compressive bi-axial strain, based on a size-mismatch theory since the boron atoms are smaller than the silicon atoms. It has been found that the large enhancement or mixing properties of dopants in silicon and germanium substrates is primarily governed by their, and to second order by their size-mismatch with the substrate. Further, it has been determined that the dopant solubility enhancement with strain is most effective when the charge and the size-mismatch of the impurity favor the same type of strain. Thus, the solid solubility of small p-type (e.g., boron) as well as large n-type (e.g., arsenic) dopants can be raised most dramatically by appropriate bi-axial (compressive) strain, and that solubility of a large p-type dopant (e.g, indium) in silicon will be raised due to size-mismatch with silicon, which favors tensile strain, while its negative charge prefers compressive strain, and thus the two effects counteract each other.

Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles

DOE PAGES

Escorihuela, Laura; Fernández, Alberto; Rallo, Robert; ...

2017-07-20

The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. This work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. We used models of small ZnO clusters to describe the final dissolved material, since the complete ionicmore » dissolution of ZnO is hindered by the formation of O 2- anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg L -1 and equivalents of 50 μg L -1 for the free Zn 2+ cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles.« less

Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles

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

Escorihuela, Laura; Fernández, Alberto; Rallo, Robert

The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. Current work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. Models of small ZnO clusters are used for describing the final dissolved material, since the complete ionicmore » dissolution of ZnO is hindered by the formation of O2- anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg·L-1 and equivalents of 50 g·L-1 for the free Zn2+ cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles.« less

Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles

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

Escorihuela, Laura; Fernández, Alberto; Rallo, Robert

The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. This work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. We used models of small ZnO clusters to describe the final dissolved material, since the complete ionicmore » dissolution of ZnO is hindered by the formation of O 2- anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg L -1 and equivalents of 50 μg L -1 for the free Zn 2+ cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles.« less

Current strategies for sustaining drug release from electrospun nanofibers

PubMed Central

Chou, Shih-Feng; Carson, Daniel; Woodrow, Kim A.

2017-01-01

Electrospun drug-eluting fibers are emerging as a novel dosage form for multipurpose prevention against sexually transmitted infections, including HIV, and unintended pregnancy. Previous work from our lab and others show the versatility of this platform to deliver large doses of physico-chemically diverse agents. However, there is still an unmet need to develop practical fiber formulations for water-soluble small molecule drugs needed at high dosing due to intrinsic low potency or desire for sustained prevention. To date, most sustained release fibers have been restricted to the delivery of biologics or hydrophobic small molecules at low drug loading of typically < 1 wt.%, which is often impractical for most clinical applications. For hydrophilic small molecule drugs, their high aqueous solubility and poor partitioning and incompatibility with insoluble polymers make long-term release even more challenging. Here we investigate several existing strategies to sustain release of hydrophilic small molecule drugs that are highly-loaded in electrospun fibers. In particular, we investigate what is known about the design constraints required to realize multi-day release from fibers fabricated from uniaxial and coaxial electrospinning. PMID:26363300

Current strategies for sustaining drug release from electrospun nanofibers.

PubMed

Chou, Shih-Feng; Carson, Daniel; Woodrow, Kim A

2015-12-28

Electrospun drug-eluting fibers are emerging as a novel dosage form for multipurpose prevention against sexually transmitted infections, including HIV, and unintended pregnancy. Previous work from our lab and others show the versatility of this platform to deliver large doses of physico-chemically diverse agents. However, there is still an unmet need to develop practical fiber formulations for water-soluble small molecule drugs needed at high dosing due to intrinsic low potency or desire for sustained prevention. To date, most sustained release fibers have been restricted to the delivery of biologics or hydrophobic small molecules at low drug loading of typically <1 wt.%, which is often impractical for most clinical applications. For hydrophilic small molecule drugs, their high aqueous solubility and poor partitioning and incompatibility with insoluble polymers make long-term release even more challenging. Here we investigate several existing strategies to sustain release of hydrophilic small molecule drugs that are highly-loaded in electrospun fibers. In particular, we investigate what is known about the design constraints required to realize multi-day release from fibers fabricated from uniaxial and coaxial electrospinning. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of oxidized tannins: comparison of depolymerization methods, asymmetric flow field-flow fractionation and small-angle X-ray scattering.

PubMed

Vernhet, Aude; Dubascoux, Stéphane; Cabane, Bernard; Fulcrand, Hélène; Dubreucq, Eric; Poncet-Legrand, Céline

2011-09-01

Condensed tannins are a major class of plant polyphenols. They play an important part in the colour and taste of foods and beverages. Due to their chemical reactivity, tannins are not stable once extracted from plants. A number of chemical reactions can take place, leading to structural changes of the native structures to give so-called derived tannins and pigments. This paper compares results obtained on native and oxidized tannins with different techniques: depolymerization followed by high-performance liquid chromatography analysis, small-angle X-ray scattering (SAXS) and asymmetric flow field-flow fractionation (AF4). Upon oxidation, new macromolecules were formed. Thioglycolysis experiments showed no evidence of molecular weight increase, but thioglycolysis yields drastically decreased. When oxidation was performed at high concentration (e.g., 10 g L(-1)), the weight average degree of polymerization determined from SAXS increased, whereas it remained stable when oxidation was done at low concentration (0.1 g L(-1)), indicating that the reaction was intramolecular, yet the conformations were different. Differences in terms of solubility were observed; ethanol being a better solvent than water. We also separated soluble and non-water-soluble species of a much oxidized fraction. Thioglycolysis showed no big differences between the two fractions, whereas SAXS and AF4 showed that insoluble macromolecules have a weight average molecular weight ten times higher than the soluble ones.

Method for measurement of radon diffusion and solubility in solid materials

NASA Astrophysics Data System (ADS)

Maier, Andreas; Weber, Uli; Dickmann, Jannis; Breckow, Joachim; van Beek, Patrick; Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia

2018-02-01

In order to study the permeation i.e. the diffusion and solubility of radon gas in biological material, a new setup was constructed and a novel analysis was applied to obtain diffusion and solubility coefficients. Thin slabs of solid materials were installed between detector housing and the surrounding radon exposure chamber of 50 Ls volume. In this setup radon can diffuse through thin test samples into a cylindrical volume of 5 mm height and 20 mm diameter and reach an α-particle detector. There the 5.49 MeV α-decay of the penetrating radon atoms is measured by a silicon surface barrier detector. The time dependent activities inside the small detector volume are recorded after injection of a known radon activity concentration into the outer chamber. Analyzing the time behavior of the integral α-activity from radon in the small vessel, both, the diffusion coefficient and solubility of the test material can be determined, based on a new mathematical model of the diffusion process concerning the special boundary conditions given by the experimental setup. These first measurements were intended as proof of concept for the detection system and the data analysis. Thin polyethylene foils (LDPE) were selected as material for the diffusion measurements and the results were in agreement with data from literature. In further measurements, we will concentrate on biological material like bone, fat and other tissues.

Complementarity determining regions and frameworks contribute to the disulfide bond independent folding of intrinsically stable scFv

PubMed Central

Gąciarz, Anna

2017-01-01

CyDisCo is a system facilitating disulfide bond formation in recombinant proteins in the cytoplasm of Escherichia coli. Previously we screened for soluble expression of single chain antibody fragments (scFv) in the cytoplasm of E. coli in the presence and absence of CyDisCo, with >90% being solubly expressed. Two scFv, those derived from natalizumab and trastuzumab, were solubly produced in high amounts even in the absence of folding catalysts i.e. disulfide bond formation is not critical for their folding. Here we investigate the contribution of the framework and the complementarity determining regions (CDRs) of scFv to the disulfide-independence of folding. We swapped CDRs between four scFv that have different properties, including two scFv that can efficiently fold independently from disulfide bonds and two more disulfide-dependent scFv. To confirm disulfide-independence we generated cysteine to alanine mutants of the disulfide-independent scFv. All of the scFv were tested for soluble expression in the cytoplasm of E. coli in the presence and absence of the oxidative folding catalysts Erv1p and PDI. Eight of the hybrid scFv were solubly produced in the presence of CyDisCo, while seven were solubly produced in the absence of CyDisCo, though the yields were often much lower when CyDisCo was absent. Soluble expression was also observed for scFv natalizumab and trastuzumab containing no cysteines. We compared yields, thermal stability and secondary structure of solubly produced scFv and undertook binding studies by western blotting, dot blotting or surface plasmon resonance of those produced in good yields. Our results indicate that both the CDRs and the framework contribute to the disulfide-dependence of soluble production of scFv, with the CDRs having the largest effect. In addition, there was no correlation between thermal stability and disulfide-dependence of folding and only a weak correlation between the yield of protein and the thermal stability of the protein. PMID:29253024

Complementarity determining regions and frameworks contribute to the disulfide bond independent folding of intrinsically stable scFv.

PubMed

Gąciarz, Anna; Ruddock, Lloyd W

2017-01-01

CyDisCo is a system facilitating disulfide bond formation in recombinant proteins in the cytoplasm of Escherichia coli. Previously we screened for soluble expression of single chain antibody fragments (scFv) in the cytoplasm of E. coli in the presence and absence of CyDisCo, with >90% being solubly expressed. Two scFv, those derived from natalizumab and trastuzumab, were solubly produced in high amounts even in the absence of folding catalysts i.e. disulfide bond formation is not critical for their folding. Here we investigate the contribution of the framework and the complementarity determining regions (CDRs) of scFv to the disulfide-independence of folding. We swapped CDRs between four scFv that have different properties, including two scFv that can efficiently fold independently from disulfide bonds and two more disulfide-dependent scFv. To confirm disulfide-independence we generated cysteine to alanine mutants of the disulfide-independent scFv. All of the scFv were tested for soluble expression in the cytoplasm of E. coli in the presence and absence of the oxidative folding catalysts Erv1p and PDI. Eight of the hybrid scFv were solubly produced in the presence of CyDisCo, while seven were solubly produced in the absence of CyDisCo, though the yields were often much lower when CyDisCo was absent. Soluble expression was also observed for scFv natalizumab and trastuzumab containing no cysteines. We compared yields, thermal stability and secondary structure of solubly produced scFv and undertook binding studies by western blotting, dot blotting or surface plasmon resonance of those produced in good yields. Our results indicate that both the CDRs and the framework contribute to the disulfide-dependence of soluble production of scFv, with the CDRs having the largest effect. In addition, there was no correlation between thermal stability and disulfide-dependence of folding and only a weak correlation between the yield of protein and the thermal stability of the protein.

Particle size reduction to the nanometer range: a promising approach to improve buccal absorption of poorly water-soluble drugs

PubMed Central

Rao, Shasha; Song, Yunmei; Peddie, Frank; Evans, Allan M

2011-01-01

Poorly water-soluble drugs, such as phenylephrine, offer challenging problems for buccal drug delivery. In order to overcome these problems, particle size reduction (to the nanometer range) and cyclodextrin complexation were investigated for permeability enhancement. The apparent solubility in water and the buccal permeation of the original phenylephrine coarse powder, a phenylephrine–cyclodextrin complex and phenylephrine nanosuspensions were characterized. The particle size and particle surface properties of phenylephrine nanosuspensions were used to optimize the size reduction process. The optimized phenylephrine nanosuspension was then freeze dried and incorporated into a multi-layered buccal patch, consisting of a small tablet adhered to a mucoadhesive film, yielding a phenylephrine buccal product with good dosage accuracy and improved mucosal permeability. The design of the buccal patch allows for drug incorporation without the need to change the mucoadhesive component, and is potentially suited to a range of poorly water-soluble compounds. PMID:21753876

Particle size reduction to the nanometer range: a promising approach to improve buccal absorption of poorly water-soluble drugs.

PubMed

Rao, Shasha; Song, Yunmei; Peddie, Frank; Evans, Allan M

2011-01-01

Poorly water-soluble drugs, such as phenylephrine, offer challenging problems for buccal drug delivery. In order to overcome these problems, particle size reduction (to the nanometer range) and cyclodextrin complexation were investigated for permeability enhancement. The apparent solubility in water and the buccal permeation of the original phenylephrine coarse powder, a phenylephrine-cyclodextrin complex and phenylephrine nanosuspensions were characterized. The particle size and particle surface properties of phenylephrine nanosuspensions were used to optimize the size reduction process. The optimized phenylephrine nanosuspension was then freeze dried and incorporated into a multi-layered buccal patch, consisting of a small tablet adhered to a mucoadhesive film, yielding a phenylephrine buccal product with good dosage accuracy and improved mucosal permeability. The design of the buccal patch allows for drug incorporation without the need to change the mucoadhesive component, and is potentially suited to a range of poorly water-soluble compounds.

Design and evaluation of self-nanoemulsifying pellets of repaglinide.

PubMed

Desai, N S; Nagarsenker, M S

2013-09-01

The aim of study was to develop self-nanoemulsifying pellets (SNEP) for oral delivery of poorly water soluble drug, repaglinide (RPG). Solubility of RPG in oily phases and surfactants was determined to identify components of self-nanoemulsifying drug delivery system (SNEDDS). The surfactants and cosurfactants were screened for their ability to emulsify oily phase. Ternary phase diagrams were constructed to identify nanoemulsification area for the selected systems. SNEDDS formulations with globule size less than 100 nm were evaluated for in vivo anti-hyperglycemic activity in neonatal streptozotocin rat model. A significant reduction in glucose levels was produced by optimized SNEDDS formulation in comparison to the control group. The optimized SNEDDS formulations were pelletized via extrusion/spheronization technique using microcrystalline cellulose and lactose. SNEP were characterized by X-ray powder diffraction and scanning electron microscopy. X-ray diffraction study indicated loss of crystallinity of RPG in SNEP. The SNEP exhibited good flow properties, mechanical strength and formed nanoemulsion with globule size less than 200 nm. SNEP showed in vitro release of more than 80% RPG in 10 min which was significantly higher than RPG containing reference pellets. In conclusion, our studies illustrated that RPG, a poorly water soluble drug can be successfully formulated into SNEP which can serve as a promising system for the delivery of poorly water soluble drugs.

The development of carbamazepine-succinic acid cocrystal tablet formulations with improved in vitro and in vivo performance.

PubMed

Ullah, Majeed; Hussain, Izhar; Sun, Changquan Calvin

2016-01-01

The use of soluble cocrystal for delivering drugs with low solubility, although a potentially effective approach, often suffers the problem of rapid disproportionation during dissolution, which negates the solubility advantages offered by the cocrystal. This necessitates their robust stabilization in order for successful use in a tablet dosage form. The cocrystal between carbamezepine and succinic acid (CBZ-SUC) exhibits a higher aqueous solubility than its dihydrate, which is the stable form of CBZ in water. Using this model system, we demonstrate an efficient and material-sparing tablet formulation screening approach enabled by intrinsic dissolution rate measurements. Three tablet formulations capable of stabilizing the cocrystal both under accelerated condition of 40 °C and 75% RH and during dissolution were developed using three different polymers, Soluplus® (F1), Kollidon VA/64 (F2) and Hydroxypropyl methyl cellulose acetate succinate (F3). When compared to a marketed product, Epitol® 200 mg tablets (F0), drug release after 60 min from formulations F1 (∼82%), F2 (∼95%) and F3 (∼95%) was all higher than that from Epitol® (79%) in a modified simulated intestinal fluid. Studies in albino rabbits show correspondingly better bioavailability of F1-F3 than Epitol.

Revealing facts behind spray dried solid dispersion technology used for solubility enhancement

PubMed Central

Patel, Bhavesh B.; Patel, Jayvadan K.; Chakraborty, Subhashis; Shukla, Dali

2013-01-01

Poor solubility and bioavailability of an existing or newly synthesized drug always pose challenge in the development of efficient pharmaceutical formulation. Numerous technologies can be used to improve the solubility and among them amorphous solid dispersion based spray drying technology can be successfully useful for development of product from lab scale to commercial scale with a wide range of powder characteristics. Current review deals with the importance of spray drying technology in drug delivery, basically for solubility and bioavailability enhancement. Role of additives, selection of polymer, effect of process and formulation parameters, scale up optimization, and IVIVC have been covered to gain the interest of readers about the technology. Design of experiment (DoE) to optimize the spray drying process has been covered in the review. A lot more research work is required to evaluate spray drying as a technology for screening the right polymer for solid dispersion, especially to overcome the issue related to drug re-crystallization and to achieve a stable product both in vitro and in vivo. Based on the recent FDA recommendation, the need of the hour is also to adopt Quality by Design approach in the manufacturing process to carefully optimize the spray drying technology for its smooth transfer from lab scale to commercial scale. PMID:27134535

Quantification of the level of fat-soluble vitamins in feed based on the novel microemulsion electrokinetic chromatography (MEEKC) method.

PubMed

Olędzka, Ilona; Kowalski, Piotr; Bałuch, Alicja; Bączek, Tomasz; Paradziej-Łukowicz, Jolanta; Taciak, Marcin; Pastuszewska, Barbara

2014-02-01

Simultaneous quantification of liposoluble vitamins is not a new area of interest, since these compounds co-determine the nutritional quality of food and feed, a field widely explored in the human and animal diet. However, the development of appropriate methods is still a matter of concern, especially when the vitamin composition is highly complex, as is the case with feed designated for laboratory animals, representing a higher health and microbiological status. A method combining microemulsion electrokinetic chromatography (MEEKC) with liquid-liquid extraction was developed for the determination of four fat-soluble vitamins in animal feed. A separation medium consisting of 25 mmol L⁻¹ phosphate buffer (pH 2.5), 2-propanol, 1-butanol, sodium dodecyl sulfate and octane allowed the simultaneous determination of vitamins A, D, E and K within a reasonable time of 25 min. The polarity of the separation voltage was reversed in view of the strongly suppressed electro-osmotic flow, and the applied voltage was set at 12 kV. The fat-soluble vitamins were separated in the order of decreasing hydrophobicity. It was proved that the proposed MEEKC method was sufficiently specific and sensitive for screening fat-soluble vitamins in animal feed samples after their sterilization. © 2013 Society of Chemical Industry.

Revealing facts behind spray dried solid dispersion technology used for solubility enhancement.

PubMed

Patel, Bhavesh B; Patel, Jayvadan K; Chakraborty, Subhashis; Shukla, Dali

2015-09-01

Poor solubility and bioavailability of an existing or newly synthesized drug always pose challenge in the development of efficient pharmaceutical formulation. Numerous technologies can be used to improve the solubility and among them amorphous solid dispersion based spray drying technology can be successfully useful for development of product from lab scale to commercial scale with a wide range of powder characteristics. Current review deals with the importance of spray drying technology in drug delivery, basically for solubility and bioavailability enhancement. Role of additives, selection of polymer, effect of process and formulation parameters, scale up optimization, and IVIVC have been covered to gain the interest of readers about the technology. Design of experiment (DoE) to optimize the spray drying process has been covered in the review. A lot more research work is required to evaluate spray drying as a technology for screening the right polymer for solid dispersion, especially to overcome the issue related to drug re-crystallization and to achieve a stable product both in vitro and in vivo. Based on the recent FDA recommendation, the need of the hour is also to adopt Quality by Design approach in the manufacturing process to carefully optimize the spray drying technology for its smooth transfer from lab scale to commercial scale.

Personalized drug discovery: HCA approach optimized for rare diseases at Tel Aviv University.

PubMed

Solmesky, Leonardo J; Weil, Miguel

2014-03-01

The Cell screening facility for personalized medicine (CSFPM) at Tel Aviv University in Israel is devoted to screening small molecules libraries for finding new drugs for rare diseases using human cell based models. The main strategy of the facility is based on smartly reducing the size of the compounds collection in similarity clusters and at the same time keeping high diversity of pharmacophores. This strategy allows parallel screening of several patient derived - cells in a personalized screening approach. The tested compounds are repositioned drugs derived from collections of phase III and FDA approved small molecules. In addition, the facility carries screenings using other chemical libraries and toxicological characterizations of nanomaterials.

Evaluation of the Role of Cisplatin-conjugated-soluble Gelatin Sponge: Feasibility Study in a Swine Model

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

Ikoma, Akira; Kawai, Nobuyuki; Sato, Morio, E-mail: morisato@wakayama-med.ac.jp

2013-08-01

PurposeTo evaluate the safety and the delivery function of cisplatin-conjugated-soluble gelatin sponge in a swine model.MethodsFifteen healthy young swine were assigned into three groups: transarterial cisplatin infusion group, transarterial chemoembolization (TACE) with cisplatin-conjugated 120-min soluble gelatin sponge (TACE-120) group, and TACE with cisplatin-conjugated 360-min soluble gelatin sponge (TACE-360) group. A total volume of 0.8 mL/kg cisplatin in each group and 8 mg/kg soluble gelatin sponge in TACE-120 and TACE-360 groups were injected from the left hepatic artery in small increments for 10 min. Common hepatic angiography and whole-blood sampling via the left hepatic vein were conducted to explore recanalization immediatelymore » after the procedure and again at 10, 30, 60, 90, 120, 180, 240, 300, 360, and 420 min later. The area under the plasma concentration curve (AUC) of non-protein-bound platinum was compared among the three groups. Each liver was removed and cut into 10-cm-thick sections for calculating liver-damaged volume ratio.ResultsSequential angiography depicted gradual recanalization of the occluded hepatic artery and total recanalization at 120 and 360 min after embolization in the TACE-120 and TACE-360 groups, respectively. Of the three groups, AUC{sub 0-30}, AUC{sub 30-120}, and AUC{sub 120-420} were significantly highest in the transarterial cisplatin infusion group (p < 0.001), the TACE-120 group (p < 0.001), and the TACE-360 group (p < 0.001), respectively. The liver-damaged volume ratio in the TACE-360 group was small (8.20 %) but significantly higher than that in the TACE-120 group (2.67 %, p = 0.014).ConclusionCisplatin-conjugated soluble gelatin sponge functions as a cisplatin carrier and is associated with tolerable liver damage.« less

Data Sources for the Model-based Small Area Estimates of Cancer Risk Factors and Screening Behaviors - Small Area Estimates

Cancer.gov

The model-based estimates of important cancer risk factors and screening behaviors are obtained by combining the responses to the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS).

Aqueous Processing for Printed Organic Electronics: Conjugated Polymers with Multistage Cleavable Side Chains

PubMed Central

2017-01-01

The ability to process conjugated polymers via aqueous solution is highly advantageous for reducing the costs and environmental hazards of large scale roll-to-roll processing of organic electronics. However, maintaining competitive electronic properties while achieving aqueous solubility is difficult for several reasons: (1) Materials with polar functional groups that provide aqueous solubility can be difficult to purify and characterize, (2) many traditional coupling and polymerization reactions cannot be performed in aqueous solution, and (3) ionic groups, though useful for obtaining aqueous solubility, can lead to a loss of solid-state order, as well as a screening of any applied bias. As an alternative, we report a multistage cleavable side chain method that combines desirable aqueous processing attributes without sacrificing semiconducting capabilities. Through the attachment of cleavable side chains, conjugated polymers have for the first time been synthesized, characterized, and purified in organic solvents, converted to a water-soluble form for aqueous processing, and brought through a final treatment to cleave the polymer side chains and leave behind the desired electronic material as a solvent-resistant film. Specifically, we demonstrate an organic soluble polythiophene that is converted to an aqueous soluble polyelectrolyte via hydrolysis. After blade coating from an aqueous solution, UV irradiation is used to cleave the polymer’s side chains, resulting in a solvent-resistant, electroactive polymer thin film. In application, this process results in aqueous printed materials with utility for solid-state charge transport in organic field effect transistors (OFETs), along with red to colorless electrochromism in ionic media for color changing displays, demonstrating its potential as a universal method for aqueous printing in organic electronics. PMID:28979937

Aqueous Processing for Printed Organic Electronics: Conjugated Polymers with Multistage Cleavable Side Chains.

PubMed

Schmatz, Brian; Yuan, Zhibo; Lang, Augustus W; Hernandez, Jeff L; Reichmanis, Elsa; Reynolds, John R

2017-09-27

The ability to process conjugated polymers via aqueous solution is highly advantageous for reducing the costs and environmental hazards of large scale roll-to-roll processing of organic electronics. However, maintaining competitive electronic properties while achieving aqueous solubility is difficult for several reasons: (1) Materials with polar functional groups that provide aqueous solubility can be difficult to purify and characterize, (2) many traditional coupling and polymerization reactions cannot be performed in aqueous solution, and (3) ionic groups, though useful for obtaining aqueous solubility, can lead to a loss of solid-state order, as well as a screening of any applied bias. As an alternative, we report a multistage cleavable side chain method that combines desirable aqueous processing attributes without sacrificing semiconducting capabilities. Through the attachment of cleavable side chains, conjugated polymers have for the first time been synthesized, characterized, and purified in organic solvents, converted to a water-soluble form for aqueous processing, and brought through a final treatment to cleave the polymer side chains and leave behind the desired electronic material as a solvent-resistant film. Specifically, we demonstrate an organic soluble polythiophene that is converted to an aqueous soluble polyelectrolyte via hydrolysis. After blade coating from an aqueous solution, UV irradiation is used to cleave the polymer's side chains, resulting in a solvent-resistant, electroactive polymer thin film. In application, this process results in aqueous printed materials with utility for solid-state charge transport in organic field effect transistors (OFETs), along with red to colorless electrochromism in ionic media for color changing displays, demonstrating its potential as a universal method for aqueous printing in organic electronics.

Statistical investigation of simulated intestinal fluid composition on the equilibrium solubility of biopharmaceutics classification system class II drugs.

PubMed

Khadra, Ibrahim; Zhou, Zhou; Dunn, Claire; Wilson, Clive G; Halbert, Gavin

2015-01-25

A drug's solubility and dissolution behaviour within the gastrointestinal tract is a key property for successful administration by the oral route and one of the key factors in the biopharmaceutics classification system. This property can be determined by investigating drug solubility in human intestinal fluid (HIF) but this is difficult to obtain and highly variable, which has led to the development of multiple simulated intestinal fluid (SIF) recipes. Using a statistical design of experiment (DoE) technique this paper has investigated the effects and interactions on equilibrium drug solubility of seven typical SIF components (sodium taurocholate, lecithin, sodium phosphate, sodium chloride, pH, pancreatin and sodium oleate) within concentration ranges relevant to human intestinal fluid values. A range of poorly soluble drugs with acidic (naproxen, indomethacin, phenytoin, and piroxicam), basic (aprepitant, carvedilol, zafirlukast, tadalafil) or neutral (fenofibrate, griseofulvin, felodipine and probucol) properties have been investigated. The equilibrium solubility results determined are comparable with literature studies of the drugs in either HIF or SIF indicating that the DoE is operating in the correct space. With the exception of pancreatin, all of the factors individually had a statistically significant influence on equilibrium solubility with variations in magnitude of effect between the acidic and basic or neutral compounds and drug specific interactions were evident. Interestingly for the neutral compounds pH was the factor with the second largest solubility effect. Around one third of all the possible factor combinations showed a significant influence on equilibrium solubility with variations in interaction significance and magnitude of effect between the acidic and basic or neutral compounds. The least number of significant media component interactions were noted for the acidic compounds with three and the greatest for the neutral compounds at seven, with again drug specific effects evident. This indicates that a drug's equilibrium solubility in SIF is influenced depending upon drug type by between eight to fourteen individual or combinations of media components with some of these drug specific. This illustrates the complex nature of these fluids and provides for individual drugs a visualisation of the possible solubility envelope within the gastrointestinal tract, which may be of importance for modelling in vivo behaviour. In addition the results indicate that the design of experiment approach can be employed to provide greater detail of drug solubility behaviour, possible drug specific interactions and influence of variations in gastrointestinal media components due to disease. The approach is also feasible and amenable to adaptation for high throughput screening of drug candidates. Copyright © 2014 Elsevier B.V. All rights reserved.

Fidelity by design: Yoctoreactor and binder trap enrichment for small-molecule DNA-encoded libraries and drug discovery.

PubMed

Blakskjaer, Peter; Heitner, Tara; Hansen, Nils Jakob Vest

2015-06-01

DNA-encoded small-molecule library (DEL) technology allows vast drug-like small molecule libraries to be efficiently synthesized in a combinatorial fashion and screened in a single tube method for binding, with an assay readout empowered by advances in next generation sequencing technology. This approach has increasingly been applied as a viable technology for the identification of small-molecule modulators to protein targets and as precursors to drugs in the past decade. Several strategies for producing and for screening DELs have been devised by both academic and industrial institutions. This review highlights some of the most significant and recent strategies along with important results. A special focus on the production of high fidelity DEL technologies with the ability to eliminate screening noise and false positives is included: using a DNA junction called the Yoctoreactor, building blocks (BBs) are spatially confined at the center of the junction facilitating both the chemical reaction between BBs and encoding of the synthetic route. A screening method, known as binder trap enrichment, permits DELs to be screened robustly in a homogeneous manner delivering clean data sets and potent hits for even the most challenging targets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhancement of Curcumin Solubility by Phase Change from Crystalline to Amorphous in Cur-TPGS Nanosuspension.

PubMed

Shin, Gye Hwa; Li, Jinglei; Cho, Jin Hun; Kim, Jun Tae; Park, Hyun Jin

2016-02-01

Nanosuspensions (NSs) were fabricated to enhance water solubility, dissolution rate, and oral adsorption of water insoluble curcumin using sonoprecipitation method. As a good stabilizer, d-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) was used to improve the stability of curcumin-TPGS NSs (Cur-TPGS NSs). Ultrasonic homogenization (UH) could effectively enhance the solubility of curcumin and to produce homogeneous NSs with small particle sizes. Water solubility of curcumin was significantly improved from 0.6 μg/mL in pure water to 260 μg/mL in the mixture of curcumin and TPGS (1:10) with UH treatment. The mean particle size of Cur-TPGS NSs was decreased significantly after UH and maintained between 208 and 246 nm. Lyophilized powder of Cur-TPGS NSs was dissolved about 91.08% whereas the pristine curcumin powder was dissolved only 6.5% at pH 7.4. This study showed a great potential of Cur-TPGS NSs as a good nano-formulation of curcumin with enhanced solubility and improved oral adsorption. © 2016 Institute of Food Technologists®

Surface shear inviscidity of soluble surfactants

PubMed Central

Zell, Zachary A.; Nowbahar, Arash; Mansard, Vincent; Leal, L. Gary; Deshmukh, Suraj S.; Mecca, Jodi M.; Tucker, Christopher J.; Squires, Todd M.

2014-01-01

Foam and emulsion stability has long been believed to correlate with the surface shear viscosity of the surfactant used to stabilize them. Many subtleties arise in interpreting surface shear viscosity measurements, however, and correlations do not necessarily indicate causation. Using a sensitive technique designed to excite purely surface shear deformations, we make the most sensitive and precise measurements to date of the surface shear viscosity of a variety of soluble surfactants, focusing on SDS in particular. Our measurements reveal the surface shear viscosity of SDS to be below the sensitivity limit of our technique, giving an upper bound of order 0.01 μN·s/m. This conflicts directly with almost all previous studies, which reported values up to 103–104 times higher. Multiple control and complementary measurements confirm this result, including direct visualization of monolayer deformation, for SDS and a wide variety of soluble polymeric, ionic, and nonionic surfactants of high- and low-foaming character. No soluble, small-molecule surfactant was found to have a measurable surface shear viscosity, which seriously undermines most support for any correlation between foam stability and surface shear rheology of soluble surfactants. PMID:24563383

Expanding pH screening space using multiple droplets with secondary buffers for protein crystallization

NASA Astrophysics Data System (ADS)

Zhang, Chen-Yan; Dong, Chen; Lu, Xiao-Li; Wang, Bei; He, Tian-Yuan; Yang, Rui-Zeng; Lin, Hua-Long; Yang, Xue-Zhou; Yin, Da-Chuan

2017-04-01

We have proposed a rational strategy for selecting a suitable pH of protein solution based on protein biochemical properties. However, it is difficult to use this strategy for biochemical properties unknown proteins. In this paper, a simpler and faster pH buffer strategy was proposed. An additional pH-controlling buffer was added to crystallization droplet mixed with protein solution and commercial crystallization reagents to adjust its pH. The results revealed that protein crystallization success rates were enhanced by this strategy due to expansion of the pH screening space, which was closely related with protein solubility. Thus, the possibility of reaching supersaturation was increased by using this strategy.

Use of a pooled clone method to isolate a novel Bacillus thuringiensis Cry2A toxin with activity against Ostrinia furnacalis.

PubMed

Shu, Changlong; Zhang, Jingtao; Chen, Guihua; Liang, Gemei; He, Kanglai; Crickmore, Neil; Huang, Dafang; Zhang, Jie; Song, Fuping

2013-09-01

A pooled clone method was developed to screen for cry2A genes. This metagenomic method avoids the need to analyse isolated Bacillus thuringiensis strains by performing gene specific PCR on plasmid-enriched DNA prepared from a pooled soil sample. Using this approach the novel holotype gene cry2Ah1 was cloned and characterized. The toxin gene was over-expressed in Escherichia coli Rosetta (DE3) and the expressed toxin accumulated in both the soluble and insoluble fractions. The soluble Cry2Ah1 was found to have a weight loss activity against Ostrinia furnacalis, and a growth inhibitory activity to both Cry1Ac-susceptible and resistant Helicoverpa armigera populations. Copyright © 2013 Elsevier Inc. All rights reserved.

Heterocyclic replacements for benzene: Maximising ADME benefits by considering individual ring isomers.

PubMed

Ritchie, Timothy J; Macdonald, Simon J F

2016-11-29

The impact of replacing a mono-substituted benzene (phenyl) ring with thirty three aromatic and nine aliphatic heterocycles on nine ADME-related screens (solubility, lipophilicity, permeability, protein binding CYP450 inhibition and metabolic clearance) was assessed using matched molecular pair analysis. The results indicate that the influence on the ADME profile can differ significantly depending on the ring identity and importantly on the individual regioisomers that are possible for some rings. This information enables the medicinal chemist to make an informed choice about which rings and regioisomers to employ as mono-substituted benzene replacements, based upon the knowledge of how such replacements are likely to influence ADME-related parameters, for example to target higher solubility whilst avoiding CYP450 liabilities. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Screening of Small Molecule Interactor Library by Using In-Cell NMR Spectroscopy (SMILI-NMR)

PubMed Central

Xie, Jingjing; Thapa, Rajiv; Reverdatto, Sergey; Burz, David S.; Shekhtman, Alexander

2011-01-01

We developed an in-cell NMR assay for screening small molecule interactor libraries (SMILI-NMR) for compounds capable of disrupting or enhancing specific interactions between two or more components of a biomolecular complex. The method relies on the formation of a well-defined biocomplex and utilizes in-cell NMR spectroscopy to identify the molecular surfaces involved in the interaction at atomic scale resolution. Changes in the interaction surface caused by a small molecule interfering with complex formation are used as a read-out of the assay. The in-cell nature of the experimental protocol insures that the small molecule is capable of penetrating the cell membrane and specifically engaging the target molecule(s). Utility of the method was demonstrated by screening a small dipeptide library against the FKBP–FRB protein complex involved in cell cycle arrest. The dipeptide identified by SMILI-NMR showed biological activity in a functional assay in yeast. PMID:19422228

Large scale nanoparticle screening for small molecule analysis in laser desorption ionization mass spectrometry

DOE PAGES

Yagnik, Gargey B.; Hansen, Rebecca L.; Korte, Andrew R.; ...

2016-08-30

Nanoparticles (NPs) have been suggested as efficient matrixes for small molecule profiling and imaging by laser-desorption ionization mass spectrometry (LDI-MS), but so far there has been no systematic study comparing different NPs in the analysis of various classes of small molecules. Here, we present a large scale screening of 13 NPs for the analysis of two dozen small metabolite molecules. Many NPs showed much higher LDI efficiency than organic matrixes in positive mode and some NPs showed comparable efficiencies for selected analytes in negative mode. Our results suggest that a thermally driven desorption process is a key factor for metalmore » oxide NPs, but chemical interactions are also very important, especially for other NPs. Furthermore, the screening results provide a useful guideline for the selection of NPs in the LDI-MS analysis of small molecules.« less

Large scale nanoparticle screening for small molecule analysis in laser desorption ionization mass spectrometry

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

Yagnik, Gargey B.; Hansen, Rebecca L.; Korte, Andrew R.

Nanoparticles (NPs) have been suggested as efficient matrixes for small molecule profiling and imaging by laser-desorption ionization mass spectrometry (LDI-MS), but so far there has been no systematic study comparing different NPs in the analysis of various classes of small molecules. Here, we present a large scale screening of 13 NPs for the analysis of two dozen small metabolite molecules. Many NPs showed much higher LDI efficiency than organic matrixes in positive mode and some NPs showed comparable efficiencies for selected analytes in negative mode. Our results suggest that a thermally driven desorption process is a key factor for metalmore » oxide NPs, but chemical interactions are also very important, especially for other NPs. Furthermore, the screening results provide a useful guideline for the selection of NPs in the LDI-MS analysis of small molecules.« less

Screening and characterization of extracellular polysaccharides produced by Leuconostoc kimchii isolated from traditional fermented pulque beverage.

PubMed

Torres-Rodríguez, Ingrid; Rodríguez-Alegría, María Elena; Miranda-Molina, Alfonso; Giles-Gómez, Martha; Conca Morales, Rodrigo; López-Munguía, Agustín; Bolívar, Francisco; Escalante, Adelfo

2014-01-01

We report the screening and characterization of EPS produced by LAB identified as Leuconostoc kimchii isolated from pulque, a traditional Mexican fermented, non-distilled alcoholic beverage produced by the fermentation of the sap extracted from several (Agave) maguey species. EPS-producing LAB constitutes an abundant bacterial group relative to total LAB present in sap and during fermentation, however, only two EPS-producing colony phenotypes (EPSA and EPSB, respectively) were detected and isolated concluding that despite the high number of polymer-producing LAB their phenotypic diversity is low. Scanning electron microcopy analysis during EPS-producing conditions revealed that both types of EPS form a uniform porous structure surrounding the bacterial cells. The structural characterization of the soluble and cell-associated EPS fractions of each polymer by enzymatic and acid hydrolysis, as by 1D- and 2D-NMR, showed that polymers produced by the soluble and cell-associated fractions of EPSA strain are dextrans consisting of a linear backbone of linked α-(1→6) Glcp in the main chain with α-(1→2) and α-(1→3)-linked branches. The polymer produced by the soluble fraction of EPSB strain was identified as a class 1 dextran with a linear backbone containing consecutive α-(1→6)-linked D-glucopyranosyl units with few α-(1→3)-linked branches, whereas the cell-associated EPS is a polymer mixture consisting of a levan composed of linear chains of (2→6)-linked β-D-fructofuranosyl residues with β-(2→6) connections, and a class 1 dextran. According to our knowledge this is the first report of dextrans and a levan including their structural characterization produced by L. kimchii isolated from a traditional fermented source.

[Construction and screening of phage antibody libraries against epidermal growth factor receptor and soluble expression of single chain Fv].

PubMed

Sheng, Wei-Jin; Miao, Qing-Fang; Zhen, Yong-Su

2009-06-01

Recent studies have shown that epidermal growth factor receptor (EGFR) is an important target for cancer therapy. The present study prepared single chain Fv (scFv) directed against EGFR. Balb/c mice were immunized by human carcinoma A431 cells, and total RNA of the splenic cells was extracted. VH and VL gene fragments were amplified by RT-PCR and further joined into scFv gene with a linker, then scFv gene fragments were ligated into the phagemid vector pCANTAB 5E. The phagemid containing scFv were transformed into electro-competent E. coli TG1 cells. The recombinant phage antibody library was constructed through rescuing the transformed cells with help phage M13K07. The specified recombinant phages were enriched through 5 rounds of affinity panning and the anti-EGFR phage scFv clones were screened and identified with ELISA. A total of 48 clones from the library were selected randomly and 45 clones were identified positive. After infecting E. coli HB2151 cells with one positive clone, soluble recombinant antibodies about 27 kD were produced and located in the periplasm and the supernatant. The result of sequencing showed that the scFv gene was 768 bp, which encoded 256 amino acid residues. VH and VL including 3 CDRs and 4 FRs, respectively, were all homologous to mouse Ig. The soluble scFv showed the specific binding activity to purified EGFR and EGFR located in carcinoma cell membrane. The successful preparation of anti-EGFR scFv will provide an EGFR targeted molecule for the development of antibody-based drugs and biological therapy of cancer.

Application of the solubility parameter concept to the design of chemiresistor arrays

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

Hughes, R.C.; Yelton, W.G.; Ricco, A.J.

1998-04-01

Arrays of unheated chemically sensitive resistors (chemiresistors) can serve as extremely small, low power consumption sensors with simple read out electronics. Most work has focused on the exotic polymeric organic metals, but here the authors report new results on carbon loaded polymer composites, as well as polymeric ionic conductors. They use the solubility parameter concept to understand and categorize the chemiresistor responses and, in particular, they compare chemiresistors fabricated from polyisobutylene (PIB) to results from PIB coated acoustic wave sensors.

Nebulization Reflux Concentrator

NASA Technical Reports Server (NTRS)

Cofer, Wesley R., III; Collins, V. G.

1986-01-01

Nebulization reflux concentrator extracts and concentrates trace quantities of water-soluble gases for subsequent chemical analysis. Hydrophobic membrane and nebulizing nozzles form scrubber for removing trace quantities of soluble gases or other contaminants from atmosphere. Although hydrophobic membrane virtually blocks all transport of droplets, it offers little resistance to gas flow; hence, device permits relatively large volumes of gas scrubbed efficiently with very small volumes of liquid. This means analyzable quantities of contaminants concentrate in extracting solutions in much shorter times than with conventional techniques.

Complexation of Statins with β-Cyclodextrin in Solutions of Small Molecular Additives and Macromolecular Colloids

NASA Astrophysics Data System (ADS)

Süle, András; Csempesz, Ferenc

The solubility of lovastatin and simvastatin (inevitable drugs in the management of cardiovascular diseases) was studied by phase-solubility measurements in multicomponent colloidal and non-colloidal media. Complexation in aqueous solutions of the highly lipophilic statins with β-cyclodextrin (β-CD) in the absence and the presence of dissolved polyvinyl pyrrolidone, its monomeric compound, tartaric acid and urea, respectively, were investigated. For the characterization of the CD-statin inclusion complexes, stability constants for the associates have been calculated.

Immobilization of enzymes by bioaffinity layering.

PubMed

Singh, Veena; Sardar, Meryam; Gupta, Munishwar Nath

2013-01-01

Bioaffinity immobilization exploits the affinity of the enzyme to a macro-(affinity ligand). Such a macro-(affinity ligand) could be a lectin, a water-soluble polymer, or a bioconjugate of a water-soluble polymer and the appropriate affinity ligand. Successive layering of the enzyme and the macro-(affinity ligand) on a matrix allows deposition of a large amount of enzyme activity on a small surface. Illustrative protocols show affinity layering of a pectinase and horseradish peroxidase on Concanavalin A-agarose and Concanavalin A-Sephadex matrices, respectively.

Optimization of three- and four-component reactions for polysubstituted piperidines: application to the synthesis and preliminary biological screening of a prototype library.

PubMed

Ulaczyk-Lesanko, Agnieszka; Pelletier, Eric; Lee, Maria; Prinz, Heino; Waldmann, Herbert; Hall, Dennis G

2007-01-01

Several solid- and solution-phase strategies were evaluated for the preparation of libraries of polysubstituted piperidines of type 7 using the tandem aza[4+2]cycloaddition/allylboration multicomponent reaction between 1-aza-4-boronobutadienes, maleimides, and aldehydes. A novel four-component variant of this chemistry was developed in solution phase, and it circumvents the need for pre-forming the azabutadiene component. A parallel synthesis coupled with compound purification by HPLC with mass-based fraction collection allowed the preparation of a library of 944 polysubstituted piperidines in a high degree of purity suitable for biological screening. A representative subset of 244 compounds was screened against a panel of phosphatase enzymes, and despite the modest levels of activity obtained, this study demonstrated that piperidines of type 7 display the right physical properties (e.g., solubility) to be assayed effectively in high-throughput enzymatic tests.

Developmental and Autism Screening: A Survey across Six States

ERIC Educational Resources Information Center

Arunyanart, Wirongrong; Fenick, Ada; Ukritchon, Supak; Imjaijitt, Worarachanee; Northrup, Veronika; Weitzman, Carol

2012-01-01

The American Academy of Pediatrics (AAP) recommends screening children for developmental delay and autism. Studies of current screening practice to date have been limited in scope and primarily focused on small, local samples. This study is designed to determine compliance with AAP screening recommendations: (1) developmental screening at 9, 18,…

The impact of particle size, relative humidity, and sulfur dioxide on iron solubility in simulated atmospheric marine aerosols.

PubMed

Cartledge, Benton T; Marcotte, Aurelie R; Herckes, Pierre; Anbar, Ariel D; Majestic, Brian J

2015-06-16

Iron is a limiting nutrient in about half of the world's oceans, and its most significant source is atmospheric deposition. To understand the pathways of iron solubilization during atmospheric transport, we exposed size segregated simulated marine aerosols to 5 ppm sulfur dioxide at arid (23 ± 1% relative humidity, RH) and marine (98 ± 1% RH) conditions. Relative iron solubility increased as the particle size decreased for goethite and hematite, while for magnetite, the relative solubility was similar for all of the fine size fractions (2.5-0.25 μm) investigated but higher than the coarse size fraction (10-2.5 μm). Goethite and hematite showed increased solubility at arid RH, but no difference (p > 0.05) was observed between the two humidity levels for magnetite. There was no correlation between iron solubility and exposure to SO2 in any mineral for any size fraction. X-ray absorption near edge structure (XANES) measurements showed no change in iron speciation [Fe(II) and Fe(III)] in any minerals following SO2 exposure. SEM-EDS measurements of SO2-exposed goethite revealed small amounts of sulfur uptake on the samples; however, the incorporated sulfur did not affect iron solubility. Our results show that although sulfur is incorporated into particles via gas-phase processes, changes in iron solubility also depend on other species in the aerosol.

Hydrotropic Solubilization of Lipophilic Drugs for Oral Delivery: The Effects of Urea and Nicotinamide on Carbamazepine Solubility–Permeability Interplay

PubMed Central

Beig, Avital; Lindley, David; Miller, Jonathan M.; Agbaria, Riad; Dahan, Arik

2016-01-01

Hydrotropy refers to increasing the water solubility of otherwise poorly soluble compound by the presence of small organic molecules. While it can certainly increase the apparent solubility of a lipophilic drug, the effect of hydrotropy on the drugs’ permeation through the intestinal membrane has not been studied. The purpose of this work was to investigate the solubility–permeability interplay when using hydrotropic drug solubilization. The concentration-dependent effects of the commonly used hydrotropes urea and nicotinamide, on the solubility and the permeability of the lipophilic antiepileptic drug carbamazepine were studied. Then, the solubility–permeability interplay was mathematically modeled, and was compared to the experimental data. Both hydrotropes allowed significant concentration-dependent carbamazepine solubility increase (up to ∼30-fold). A concomitant permeability decrease was evident both in vitro and in vivo (∼17-fold for nicotinamide and ∼9-fold for urea), revealing a solubility–permeability tradeoff when using hydrotropic drug solubilization. A relatively simplified simulation approach based on proportional opposite correlation between the solubility increase and the permeability decrease at a given hydrotrope concentration allowed excellent prediction of the overall solubility–permeability tradeoff. In conclusion, when using hydrotropic drug solubilization it is prudent to not focus solely on solubility, but to account for the permeability as well; achieving optimal solubility–permeability balance may promote the overall goal of the formulation to maximize oral drug exposure. PMID:27826241

Improving Physical Properties via C–H Oxidation: Chemical and Enzymatic Approaches

PubMed Central

Michaudel, Quentin; Journot, Guillaume; Regueiro-Ren, Alicia; Goswami, Animesh; Guo, Zhiwei; Tully, Thomas P.; Zou, Lufeng; Ramabhadran, Raghunath O.; Houk, Kendall N.

2014-01-01

Physicochemical properties constitute a key factor for the success of a drug candidate. Whereas many strategies to improve the physicochemical properties of small heterocycle-type leads exist, complex hydrocarbon skeletons are more challenging to derivatize due to the absence of functional groups. A variety of C–H oxidation methods have been explored on the betulin skeleton to improve the solubility of this very bioactive, yet poorly water soluble, natural product. Capitalizing on the innate reactivity of the molecule, as well as the few molecular handles present on the core, allowed for oxidations at different positions across the pentacyclic structure. Enzymatic oxidations afforded several orthogonal oxidations to chemical methods. Solubility measurements showed an enhancement for many of the synthesized compounds. PMID:25244630

Evaluation of rubella screening in pregnant women

PubMed Central

Gyorkos, T W; Tannenbaum, T N; Abrahamowicz, M; Delage, G; Carsley, J; Marchand, S

1998-01-01

BACKGROUND: The rationale for rubella vaccination in the general population and for screening for rubella in pregnant women is the prevention of congenital rubella syndrome. The objective of this study was to evaluate the effectiveness of the prenatal rubella screening program in Quebec. METHODS: A historical cross-sectional study was designed. Sixteen hospitals with obstetric services were randomly selected, 8 from among the 35 "large" hospitals in the province (500 or more live births/year) and 8 from among the 50 "small" hospitals (fewer than 500 live births/year). A total of 2551 women were randomly selected from all mothers of infants born between Apr. 1, 1993, and Mar. 31, 1994, by means of stratified 2-stage sampling. The proportions of women screened and vaccinated were ascertained from information obtained from the hospital chart, the physician's office and the patient. RESULTS: The overall (adjusted) screening rate was 94.0%. The rates were significantly different between large and small hospitals (94.4% v. 89.6%). Five large hospitals and one small hospital had rates above 95.0%. The likelihood of not having been screened was statistically significantly higher for women who had been pregnant previously than for women pregnant for the first time (4.8% v. 1.4%; p < 0.001). Of the 200 women who were seronegative at the time of screening (8.4%), 79 had been vaccinated postpartum, had a positive serological result on subsequent testing or did not require vaccination, and 59 had not been vaccinated postpartum; for 62, subsequent vaccination status was unknown. INTERPRETATION: Continued improvement in screening practices is needed, especially in small hospitals. Because vaccination rates are unacceptably low, it is crucial that steps be taken to address this issue. PMID:9835876

Influence of dietary fiber on luminal environment and morphology in the small and large intestine of sows.

PubMed

Serena, A; Hedemann, M S; Bach Knudsen, K E

2008-09-01

In this study, the effect of feeding different types and amounts of dietary fiber (DF) on luminal environment and morphology in the small and large intestine of sows was studied. Three diets, a low-fiber diet (LF) and 2 high-fiber diets (high fiber 1, HF1, and high fiber 2, HF2) were used. Diet LF (DF, 17%; soluble DF 4.6%) was based on wheat and barley, whereas the 2 high-fiber diets (HF1: DF, 43%; soluble DF, 11.0%; and HF2: DF, 45%; soluble DF, 7.6%) were based on wheat and barley supplemented with different coproducts from the vegetable food and agroindustry (HF1 and HF2: sugar beet pulp, potato pulp, and pectin residue; HF2: brewers spent grain, seed residue, and pea hull). The diets were fed for a 4-wk period to 12 sows (4 receiving each diet). Thereafter, the sows were killed 4 h postfeeding, and digesta and tissue samples were collected from various parts of the small and large intestine. The carbohydrates in the LF diet were well digested in the small intestine, resulting in less digesta in all segments of the intestinal tract. The fermentation of nonstarch polysaccharides in the large intestine was affected by the chemical composition and physicochemical properties. The digesta from pigs fed the LF diet provided low levels of fermentable carbohydrates that were depleted in proximal colon, whereas for pigs fed the 2 high-DF diets, the digesta was depleted of fermentable carbohydrates at more distal locations of the colon. The consequence was an increased retention time, greater DM percentage, decreased amount of material, and a decreased tissue weight after feeding the LF diet compared with the HF diets. The concentration of short-chain fatty acids was consistent with the fermentability of carbohydrates in the large intestine, but there was no effect of the dietary composition on the molar short-chain fatty acid proportions. It was further shown that feeding the diet providing the greatest amount of fermentable carbohydrates (diet HF1, which was high in soluble DF) resulted in significant morphological changes in the colon compared with the LF diet.

Identification of M-CSF agonists and antagonists

DOEpatents

Pandit, Jayvardhan [Mystic, CT; Jancarik, Jarmila [Walnut Creek, CA; Kim, Sung-Hou [Moraga, CA; Koths, Kirston [El Cerrito, CA; Halenbeck, Robert [San Rafael, CA; Fear, Anna Lisa [Oakland, CA; Taylor, Eric [Oakland, CA; Yamamoto, Ralph [Martinez, CA; Bohm, Andrew [Armonk, NY

2000-02-15

The present invention is directed to methods for crystallizing macrophage colony stimulating factor. The present invention is also directed to methods for designing and producing M-CSF agonists and antagonists using information derived from the crystallographic structure of M-CSF. The invention is also directed to methods for screening M-CSF agonists and antagonists. In addition, the present invention is directed to an isolated, purified, soluble and functional M-CSF receptor.

Recombinant expression of extracellular domain of mutant Epidermal Growth Factor Receptor in prokaryotic and baculovirus expression systems.

PubMed

Vettath, Sunitha Kodengil; Shivashankar, Gaganashree; Menon, Krishnakumar N; Vijayachandran, Lakshmi S

2018-04-15

Epidermal Growth Factor Receptor variant III (EGFRvIII) is a tumor specific antigen detected in various tumors including gliomas, breast cancer, lung cancer, head and neck squamous cell carcinoma (HNSCC). Screening of EGFRvIII targeting drug molecules can be accelerated by developing drug screening platforms using recombinantly expressed protein. Choice of expression system is one of the major factors deciding the success of recombinant expression of a protein. In our study, we have tried to express and purify the extracellular domain (ECD) of this highly unstable protein using bacterial and baculovirus expression systems to select the expression system suited for our purpose. Even though the protein was successfully expressed in prokaryotic system, purification could be done only under denaturing conditions. But in the baculovirus expression system, the protein was expressed in soluble form and could be purified under native conditions, with single step of purification. Based on our results, we conclude that insect cells are better choice over E. coli cells for expressing EGFRvIII ECD in soluble form. This study provides insights for other researchers involved in expression of similar unstable membrane proteins, on selecting the best expression system and challenges involved. Copyright © 2018 Elsevier B.V. All rights reserved.

A broad pH range indicator-based spectrophotometric assay for true lipases using tributyrin and tricaprylin.

PubMed

Camacho-Ruiz, María de Los Angeles; Mateos-Díaz, Juan Carlos; Carrière, Frédéric; Rodriguez, Jorge A

2015-05-01

A continuous assay is proposed for the screening of acidic, neutral, or alkaline lipases using microtiter plates, emulsified short- and medium-chain TGs, and a pH indicator. The lipase activity measurement is based on the decrease of the pH indicator optical density due to protonation which is caused by the release of FFAs during the hydrolysis of TGs and thus acidification. Purified lipases with distinct pH optima and an esterase were used to validate the method. The rate of lipolysis was found to be linear with time and proportional to the amount of enzyme added in each case. Specific activities measured with this microplate assay method were lower than those obtained by the pH-stat technique. Nevertheless, the pH-dependent profiles of enzymatic activity were similar with both assays. In addition, the substrate preference of each enzyme tested was not modified and this allowed discriminating lipase and esterase activities using tributyrin (low water solubility) and tricaprylin (not water soluble) as substrates. This continuous lipase assay is compatible with a high sample throughput and can be applied for the screening of lipases and lipase inhibitors from biological samples. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

A novel microseeding method for the crystallization of membrane proteins in lipidic cubic phase.

PubMed

Kolek, Stefan Andrew; Bräuning, Bastian; Stewart, Patrick Douglas Shaw

2016-04-01

Random microseed matrix screening (rMMS), in which seed crystals are added to random crystallization screens, is an important breakthrough in soluble protein crystallization that increases the number of crystallization hits that are available for optimization. This greatly increases the number of soluble protein structures generated every year by typical structural biology laboratories. Inspired by this success, rMMS has been adapted to the crystallization of membrane proteins, making LCP seed stock by scaling up LCP crystallization conditions without changing the physical and chemical parameters that are critical for crystallization. Seed crystals are grown directly in LCP and, as with conventional rMMS, a seeding experiment is combined with an additive experiment. The new method was used with the bacterial integral membrane protein OmpF, and it was found that it increased the number of crystallization hits by almost an order of magnitude: without microseeding one new hit was found, whereas with LCP-rMMS eight new hits were found. It is anticipated that this new method will lead to better diffracting crystals of membrane proteins. A method of generating seed gradients, which allows the LCP seed stock to be diluted and the number of crystals in each LCP bolus to be reduced, if required for optimization, is also demonstrated.

Oral Administration and Detection of a Near-Infrared Molecular Imaging Agent in an Orthotopic Mouse Model for Breast Cancer Screening

PubMed Central

2018-01-01

Molecular imaging is advantageous for screening diseases such as breast cancer by providing precise spatial information on disease-associated biomarkers, something neither blood tests nor anatomical imaging can achieve. However, the high cost and risks of ionizing radiation for several molecular imaging modalities have prevented a feasible and scalable approach for screening. Clinical studies have demonstrated the ability to detect breast tumors using nonspecific probes such as indocyanine green, but the lack of molecular information and required intravenous contrast agent does not provide a significant benefit over current noninvasive imaging techniques. Here we demonstrate that negatively charged sulfate groups, commonly used to improve solubility of near-infrared fluorophores, enable sufficient oral absorption and targeting of fluorescent molecular imaging agents for completely noninvasive detection of diseased tissue such as breast cancer. These functional groups improve the pharmacokinetic properties of affinity ligands to achieve targeting efficiencies compatible with clinical imaging devices using safe, nonionizing radiation (near-infrared light). Together, this enables development of a “disease screening pill” capable of oral absorption and systemic availability, target binding, background clearance, and imaging at clinically relevant depths for breast cancer screening. This approach should be adaptable to other molecular targets and diseases for use as a new class of screening agents. PMID:29696981

Oral Administration and Detection of a Near-Infrared Molecular Imaging Agent in an Orthotopic Mouse Model for Breast Cancer Screening.

PubMed

Bhatnagar, Sumit; Verma, Kirti Dhingra; Hu, Yongjun; Khera, Eshita; Priluck, Aaron; Smith, David E; Thurber, Greg M

2018-05-07

Molecular imaging is advantageous for screening diseases such as breast cancer by providing precise spatial information on disease-associated biomarkers, something neither blood tests nor anatomical imaging can achieve. However, the high cost and risks of ionizing radiation for several molecular imaging modalities have prevented a feasible and scalable approach for screening. Clinical studies have demonstrated the ability to detect breast tumors using nonspecific probes such as indocyanine green, but the lack of molecular information and required intravenous contrast agent does not provide a significant benefit over current noninvasive imaging techniques. Here we demonstrate that negatively charged sulfate groups, commonly used to improve solubility of near-infrared fluorophores, enable sufficient oral absorption and targeting of fluorescent molecular imaging agents for completely noninvasive detection of diseased tissue such as breast cancer. These functional groups improve the pharmacokinetic properties of affinity ligands to achieve targeting efficiencies compatible with clinical imaging devices using safe, nonionizing radiation (near-infrared light). Together, this enables development of a "disease screening pill" capable of oral absorption and systemic availability, target binding, background clearance, and imaging at clinically relevant depths for breast cancer screening. This approach should be adaptable to other molecular targets and diseases for use as a new class of screening agents.

Different Patterns of Cytokines and Chemokines Combined with IFN-γ Production Reflect Mycobacterium tuberculosis Infection and Disease

PubMed Central

Hu, Shizong; Jin, Dongdong; Chen, Xinchun; Jin, Qi; Liu, Haiying

2012-01-01

Background IFN-γ is presently the only soluble immunological marker used to help diagnose latent Mycobacterium tuberculosis (M.tb) infection. However, IFN-γ is not available to distinguish latent from active TB infection. Moreover, extrapulmonary tuberculosis, such as tuberculous pleurisy, cannot be properly diagnosed by IFN-γ release assay. As a result, other disease- or infection-related immunological biomarkers that would be more effective need to be screened and identified. Methodology A panel of 41 soluble immunological molecules (17 cytokines and 24 chemokines) was tested using Luminex liquid array-based multiplexed immunoassays. Samples, including plasma and pleural effusions, from healthy donors (HD, n = 12) or patients with latent tuberculosis infection (LTBI, n = 20), pulmonary tuberculosis (TB, n = 12), tuberculous pleurisy (TP, n = 15) or lung cancer (LC, n = 15) were collected and screened for soluble markers. Peripheral blood mononuclear cells (PBMCs) and pleural fluid mononuclear cells (PFMCs) were also isolated to investigate antigen-specific immune factors. Principal Findings For the 41 examined factors, our results indicated that three patterns were closely associated with infection and disease. (1) Significantly elevated plasma levels of IL-2, IP-10, CXCL11 and CXCL12 were present in both patients with tuberculosis and in a sub-group participant with latent tuberculosis infection who showed a higher level of IFN-γ producing cells by ELISPOT assay compared with other latently infected individuals. (2) IL-6 and IL-9 were only significantly increased in plasma from active TB patients, and the two factors were consistently highly secreted after M.tb antigen stimulation. (3) When patients developed tuberculous pleurisy, CCL1, CCL21 and IL-6 were specifically increased in the pleural effusions. In particular, these three factors were consistently highly secreted by pleural fluid mononuclear cells following M.tb-specific antigen stimulation. In conclusion, our data imply that the specific secretion of soluble immunological factors, in addition to IFN-γ, may be used to evaluate M.tb infection and tuberculosis disease. PMID:23028695

Effect of counter ions of arginine as an additive for the solubilization of protein and aromatic compounds.

PubMed

Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

2016-10-01

Arginine is widely used in biotechnological application, but mostly with chloride counter ion. Here, we examined the effects of various anions on solubilization of aromatic compounds and reduced lysozyme and on refolding of the lysozyme. All arginine salts tested increased the solubility of propyl gallate with acetate much more effectively than chloride. The effects of arginine salts were compared with those of sodium or guanidine salts, indicating that the ability of anions to modulate the propyl gallate solubility is independent of the cation. Comparison of transfer free energy of propyl gallate between sodium and arginine salts indicates that the interaction of propyl gallate is more favorable with arginine than sodium. On the contrary, the solubility of aromatic amino acids is only slightly modulated by anions, implying that there is specific interaction between acetic acid and propyl gallate. Unlike their effects on the solubility of small aromatic compounds, the solubility of reduced lysozyme was much higher in arginine chloride than in arginine acetate or sulfate. Consistent with high solubility, refolding of reduced lysozyme was most effective in arginine chloride. These results suggest potential broader applications of arginine modulated by different anions. Copyright © 2016 Elsevier B.V. All rights reserved.

High-throughput screening of chromatographic separations: II. Hydrophobic interaction.

PubMed

Kramarczyk, Jack F; Kelley, Brian D; Coffman, Jonathan L

2008-07-01

A high-throughput screen (HTS) was developed to evaluate the selectivity of various hydrophobic interaction chromatography (HIC) resins for separating a mAb from aggregate species. Prior to the resin screen, the solubility of the protein was assessed to determine the allowable HIC operating region by examining 384 combinations of pH, salt, and protein concentration. The resin screen then incorporated 480 batch-binding and elution conditions with eight HIC resins in combination with six salts. The results from the screen were reproducible, and demonstrated quantitative recovery of the mAb and aggregate. The translation of the HTS batch-binding data to lab-scale chromatography columns was tested for four conditions spanning the range of product binding and selectivity. After accounting for the higher number of theoretical plates in the columns, the purity and recovery of the lab-scale column runs agreed with the HTS results demonstrating the predictive power of the filterplate system. The HTS data were further analyzed by the calculation of pertinent thermodynamic parameters such as the partition coefficient, K(P), and the separation factor, alpha. The separation factor was used to rank the purification capabilities of the resin and salt conditions explored. (c) 2008 Wiley Periodicals, Inc.

University of Texas Southwestern Medical Center: U01 Natural Products Screening | Office of Cancer Genomics

Cancer.gov

The goal of this project was to enlarge the chemical space probed by Project 1 (High-Throughput siRNA Screening of a Non-Small Cell Lung Cancer Cell Line Panel) by screening an expanded natural products library (~40,000) in an effort to further define vulnerabilities and therapeutic targets in non-small cell lung cancer. This new library is derived from a diverse collection of marine bacteria (prepared by Dr. John MacMillan, University of Texas Southwestern).

University of Texas Southwestern Medical Center (UTSW): U01 Natural Products Screening | Office of Cancer Genomics

Cancer.gov

The goal of this project was to enlarge the chemical space probed by Project 1 (High-Throughput siRNA Screening of a Non-Small Cell Lung Cancer Cell Line Panel) by screening an expanded natural products library (~40,000) in an effort to further define vulnerabilities and therapeutic targets in non-small cell lung cancer. This new library is derived from a diverse collection of marine bacteria (prepared by Dr. John MacMillan, University of Texas Southwestern).

The apparent solubility of aluminum (III) in Hanford high-level waste.

PubMed

Reynolds, Jacob G

2012-01-01

The solubility of aluminum in Hanford nuclear waste impacts on the processability of the waste by a number of proposed treatment options. For many years, Hanford staff has anecdotally noted that aluminum appears to be considerably more soluble in Hanford waste than the simpler electrolyte solutions used as analogues. There has been minimal scientific study to confirm these anecdotal observations, however. The present study determines the apparent solubility product for gibbsite in 50 tank samples. The ratio of hydroxide to aluminum in the liquid phase for the samples is calculated and plotted as a function of total sodium molarity. Total sodium molarity is used as a surrogate for ionic strength, because the relative ratios of mono-, di- and trivalent anions are not available for all of the samples. These results were compared to the simple NaOH-NaAl(OH)(4)-H(2)O system, and the NaOH-NaAl(OH)(4)-NaCl-H(2)O system data retrieved from the literature. The results show that gibbsite is apparently more soluble in the samples than in the simple systems whenever the sodium molarity is greater than 2M. This apparent enhanced solubility cannot be explained solely by differences in ionic strength. The change in solubility with ionic strength in simple systems is small compared to the difference between aluminum solubility in Hanford waste and the simple systems. The reason for the apparent enhanced solubility is unknown, but could include kinetic or thermodynamic factors that are not present in the simple electrolyte systems. Any kinetic explanation would have to explain why the samples are always supersaturated whenever the sodium molarity is above 2M. Real waste characterization data should not be used to validate thermodynamic solubility models until it can be confirmed that the apparent enhanced gibbsite solubility is a thermodynamic effect and not a kinetic effect.

The apparent solubility of aluminum (III) in Hanford high-level waste

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

Reynolds, Jacob G.

2012-12-01

The solubility of aluminum in Hanford nuclear waste impacts on the process ability of the waste by a number of proposed treatment options. For many years, Hanford staff has anecdotally noted that aluminum appears to be considerably more soluble in Hanford waste than the simpler electrolyte solutions used as analogues. There has been minimal scientific study to confirm these anecdotal observations, however. The present study determines the apparent solubility product for gibbsite in 50 tank samples. The ratio of hydroxide to aluminum in the liquid phase for the samples is calculated and plotted as a function of total sodium molarity.more » Total sodium molarity is used as a surrogate for ionic strength, because the relative ratios of mono, di and trivalent anions are not available for all of the samples. These results were compared to the simple NaOH-NaAl(OH{sub 4})H{sub 2}O system, and the NaOH-NaAl(OH{sub 4})NaCl-H{sub 2}O system data retrieved from the literature. The results show that gibbsite is apparently more soluble in the samples than in the simple systems whenever the sodium molarity is greater than two. This apparent enhanced solubility cannot be explained solely by differences in ionic strength. The change in solubility with ionic strength in simple systems is small compared to the difference between aluminum solubility in Hanford waste and the simple systems. The reason for the apparent enhanced solubility is unknown, but could include. kinetic or thermodynamic factors that are not present in the simple electrolyte systems. Any kinetic explanation would have to explain why the samples are always supersaturated whenever the sodium molarity is above two. Real waste characterization data should not be used to validate thermodynamic solubility models until it can be confirmed that the apparent enhanced gibbsite solubility is a thermodynamic effect and not a kinetic effect.« less

The complexity of intestinal permeability: Assigning the correct BCS classification through careful data interpretation.

PubMed

Zur, Moran; Hanson, Allison S; Dahan, Arik

2014-09-30

While the solubility parameter is fairly straightforward when assigning BCS classification, the intestinal permeability (Peff) is more complex than generally recognized. In this paper we emphasize this complexity through the analysis of codeine, a commonly used antitussive/analgesic drug. Codeine was previously classified as a low-permeability compound, based on its lower LogP compared to metoprolol, a marker for the low-high permeability class boundary. In contrast, high fraction of dose absorbed (Fabs) was reported for codeine, which challenges the generally recognized Peff-Fabs correlation. The purpose of this study was to clarify this ambiguity through elucidation of codeine's BCS solubility/permeability class membership. Codeine's BCS solubility class was determined, and its intestinal permeability throughout the small intestine was investigated, both in vitro and in vivo in rats. Codeine was found to be unequivocally a high-solubility compound. All in vitro studies indicated that codeine's permeability is higher than metoprolol's. In vivo studies in rats showed similar permeability for both drugs throughout the entire small-intestine. In conclusion, codeine was found to be a BCS Class I compound. No Peff-Fabs discrepancy is involved in its absorption; rather, it reflects the risk of assigning BCS classification based on merely limited physicochemical characteristics. A thorough investigation using multiple experimental methods is prudent before assigning a BCS classification, to avoid misjudgment in various settings, e.g., drug discovery, formulation design, drug development and regulation. Copyright © 2013 Elsevier B.V. All rights reserved.

[Small compounds libraries: a research tool for chemical biology].

PubMed

Florent, Jean-Claude

2013-01-01

Obtaining and screening collections of small molecules remain a challenge for biologists. Recent advances in analytical techniques and instrumentation now make screening possible in academia. The history of the creation of such public or commercial collections and their accessibility is related. It shows that there is interest for an academic laboratory involved in medicinal chemistry, chemogenomics or "chemical biology" to organize its own collection and make it available through existing networks such as the French National chimiothèque or the European partner network "European Infrastructure of open screening platforms for Chemical Biology" EU-OpenScreen under construction. © Société de Biologie, 2013.

Orodispersible films in individualized pharmacotherapy: The development of a formulation for pharmacy preparations.

PubMed

Visser, J Carolina; Woerdenbag, Herman J; Crediet, Stefan; Gerrits, Edwin; Lesschen, Marjan A; Hinrichs, Wouter L J; Breitkreutz, Jörg; Frijlink, Henderik W

2015-01-15

Orodispersible films (ODFs) are promising drug delivery systems for customized small scale pharmacy preparations. The aim of the present study was to develop a versatile casting solution suitable for the extemporaneous production of ODFs to which active pharmaceutical ingredients (APIs) can be added. Different combinations of film forming agents and other excipients and different casting heights were tested for their suitability for production of ODFs. The best suitable casting solution contained hypromellose, carbomer, glycerol, disodium EDTA and trometamol. This casting solution was used to prepare ODFs containing water-soluble APIs (enalapril maleate and prednisolone disodium phosphate) and a poorly water-soluble API (diazepam) for which ethanol 96% was used as co-solvent.The water-soluble APIs as well as ethanol influenced the viscosity of the casting solution, mechanical properties and disintegration time of the ODFs. All ODFs containing API met the requirements on uniformity of mass and uniformity of content set by the European Pharmacopoeia (2014) (Ph. Eur.) 8th edition. In conclusion, ODFs of good pharmaceutical quality can be prepared on small scale. Hereby opening the perspective of using ODFs for individualized pharmacotherapy. Copyright © 2014 Elsevier B.V. All rights reserved.

Methodology for the Model-based Small Area Estimates of Cancer Risk Factors and Screening Behaviors - Small Area Estimates

Cancer.gov

This model-based approach uses data from both the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS) to produce estimates of the prevalence rates of cancer risk factors and screening behaviors at the state, health service area, and county levels.

A small-bolt method for screening tree protectants against bark beetles (coleoptera: curculionidae)

Treesearch

B.L. Strom; L.M. Roton

2009-01-01

A simple, small-bolt method was developed and refi ned for evaluating and screening treatments being considered as prophylactics against bark beetles (Coleoptera: Curculionidae: Scolytinae). Using this method, 4 insecticide products (3 active ingredients) were evaluated against the southern pine beetle, Dendroctonus frontalis Zimmermann, intermittently during a period...

PLASMA PROTEIN PROFILING AS A HIGH THROUGHPUT TOOL FOR CHEMICAL SCREENING USING A SMALL FISH MODEL

EPA Science Inventory

Hudson, R. Tod, Michael J. Hemmer, Kimberly A. Salinas, Sherry S. Wilkinson, James Watts, James T. Winstead, Peggy S. Harris, Amy Kirkpatrick and Calvin C. Walker. In press. Plasma Protein Profiling as a High Throughput Tool for Chemical Screening Using a Small Fish Model (Abstra...

Absorption sites of orally administered drugs in the small intestine.

PubMed

Murakami, Teruo

2017-12-01

In pharmacotherapy, drugs are mostly taken orally to be absorbed systemically from the small intestine, and some drugs are known to have preferential absorption sites in the small intestine. It would therefore be valuable to know the absorption sites of orally administered drugs and the influencing factors. Areas covered:In this review, the author summarizes the reported absorption sites of orally administered drugs, as well as, influencing factors and experimental techniques. Information on the main absorption sites and influencing factors can help to develop ideal drug delivery systems and more effective pharmacotherapies. Expert opinion: Various factors including: the solubility, lipophilicity, luminal concentration, pKa value, transporter substrate specificity, transporter expression, luminal fluid pH, gastrointestinal transit time, and intestinal metabolism determine the site-dependent intestinal absorption. However, most of the dissolved fraction of orally administered drugs including substrates for ABC and SLC transporters, except for some weakly basic drugs with higher pKa values, are considered to be absorbed sequentially from the proximal small intestine. Securing the solubility and stability of drugs prior to reaching to the main absorption sites and appropriate delivery rates of drugs at absorption sites are important goals for achieving effective pharmacotherapy.

[Effect of gene optimization on the expression and purification of HDV small antigen produced by genetic engineering].

PubMed

Ding, Jun-Ying; Meng, Qing-Ling; Guo, Min-Zhuo; Yi, Yao; Su, Qiu-Dong; Lu, Xue-Xin; Qiu, Feng; Bi, Sheng-Li

2012-10-01

To study the effect of gene optimization on the expression and purification of HDV small antigen produced by genetic engineering. Based on the colon preference of E. coli, the HDV small antigen original gene from GenBank was optimized. Both the original gene and the optimized gene expressed in prokaryotic cells, SDS-PAGE was made to analyze the protein expression yield and to decide which protein expression style was more proportion than the other. Furthermore, two antigens were purified by chromatography in order to compare the purity by SDS-PAGE and Image Lab software. SDS-PAGE indicated that the molecular weight of target proteins from two groups were the same as we expected. Gene optimization resulted in the higher yield and it could make the product more soluble. After chromatography, the purity of target protein from optimized gene was up to 96.3%, obviously purer than that from original gene. Gene optimization could increase the protein expression yield and solubility of genetic engineering HDV small antigen. In addition, the product from the optimized gene group was easier to be purified for diagnosis usage.

Analysis of flow decay potential on Galileo. [oxidizer flow rate reduction by iron nitrate precipitates

NASA Technical Reports Server (NTRS)

Cole, T. W.; Frisbee, R. H.; Yavrouian, A. H.

1987-01-01

The risks posed to the NASA's Galileo spacecraft by the oxidizer flow decay during its extended mission to Jupiter is discussed. The Galileo spacecraft will use nitrogen tetroxide (NTO)/monomethyl hydrazine bipropellant system with one large engine thrust-rated at a nominal 400 N, and 12 smaller engines each thrust-rated at a nominal 10 N. These smaller thrusters, because of their small valve inlet filters and small injector ports, are especially vulnerable to clogging by iron nitrate precipitates formed by NTO-wetted stainless steel components. To quantify the corrosion rates and solubility levels which will be seen during the Galileo mission, corrosion and solubility testing experiments were performed with simulated Galileo materials, propellants, and environments. The results show the potential benefits of propellant sieving in terms of iron and water impurity reduction.

Protecting health.

PubMed

Armour, Margaret-Ann; Linetsky, Asya; Ashick, Donna

2008-10-01

Water-soluble heavy metal salts injure health when they leach into water supplies. It is important that students who may later be employed in industries generating aqueous solutions of such salts are aware of the methods that can be used to recover the metal salt or transform it to non-health threatening products. The research was in the management of small quantities of hazardous wastes, such as are generated in school, college, and university teaching laboratories; in research laboratories; in industrial quality control and testing laboratories; and in small industries. Methods for the recovery of silver, nickel, and cobalt salts from relatively small volumes of aqueous solutions of their soluble salts were developed and tested. Where it was not practical to recover the metal salt, the practice has been to convert it to a water-insoluble salt, often the sulfide. This requires the use of highly toxic reagents. It was found that a number of heavy metal salts can be precipitated as the silicates, returning them to the form in which they are found in the natural ore. These salts show similar solubility properties to the sulfides in neutral, acidic, and basic aqueous solutions. The work has determined the conditions, quantities, and solution acidity that result in the most effective precipitation of the heavy metal salt. The concentration of the metal ions remaining in solution was measured by AA and ICP spectrometry. Specific methods have been developed for the conversion of salts of mercury and chromium to nonsoluble products.

New ligation independent cloning vectors for expression of recombinant proteins with a self-cleaving CPD/6xHis-tag.

PubMed

Biancucci, Marco; Dolores, Jazel S; Wong, Jennifer; Grimshaw, Sarah; Anderson, Wayne F; Satchell, Karla J F; Kwon, Keehwan

2017-01-05

Recombinant protein purification is a crucial step for biochemistry and structural biology fields. Rapid robust purification methods utilize various peptide or protein tags fused to the target protein for affinity purification using corresponding matrices and to enhance solubility. However, affinity/solubility-tags often need to be removed in order to conduct functional and structural studies, adding complexities to purification protocols. In this work, the Vibrio cholerae MARTX toxin Cysteine Protease Domain (CPD) was inserted in a ligation-independent cloning (LIC) vector to create a C-terminal 6xHis-tagged inducible autoprocessing enzyme tag, called "the CPD-tag". The pCPD and alternative pCPD/ccdB cloning vectors allow for easy insertion of DNA and expression of the target protein fused to the CPD-tag, which is removed at the end of the purification step by addition of the inexpensive small molecule inositol hexakisphosphate to induce CPD autoprocessing. This process is demonstrated using a small bacterial membrane localization domain and for high yield purification of the eukaryotic small GTPase KRas. Subsequently, pCPD was tested with 40 proteins or sub-domains selected from a high throughput crystallization pipeline. pCPD vectors are easily used LIC compatible vectors for expression of recombinant proteins with a C-terminal CPD/6xHis-tag. Although intended only as a strategy for rapid tag removal, this pilot study revealed the CPD-tag may also increase expression and solubility of some recombinant proteins.

Chemical Characteristics of Water-Soluble Ions in Particulate Matter in Three Metropolitan Areas in the North China Plain

PubMed Central

Dao, Xu; Wang, Zhen; Lv, Yibing; Teng, Enjiang; Zhang, Linlin; Wang, Chao

2014-01-01

PM2.5 and PM10 samples were collected simultaneously in each season in Beijing, Tianjin and Shijiazhuang to identify the characteristics of water-soluble ion compositions in the North China Plain. The water-soluble ions displayed significant seasonal variation. The dominant ions were NO3 −, SO4 2−, NH4 + and Cl−, accounting for more than 90% and 86% to the mass of total water-soluble ions in PM2.5 and PM10, respectively. The anion/cation ratio indicated that the ion acidity of each city varied both between sites and seasonally. Over 50% of the ion species were enriched in small particles ≤1 µm in diameter. The [NO3 −]/[SO4 2−] ratio indicated that vehicles accounted for the majority of the particulate pollution in Beijing. Shijiazhuang, a city highly reliant on coal combustion, had a higher SO4 2− concentration. PMID:25437210

Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

PubMed Central

Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

2016-01-01

Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V. PMID:27966605

Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

NASA Astrophysics Data System (ADS)

Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

2016-12-01

Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V.

Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility.

PubMed

Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

2016-12-14

Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V.

Enzyme-resistant dextrins from potato starch for potential application in the beverage industry.

PubMed

Jochym, Kamila Kapusniak; Nebesny, Ewa

2017-09-15

The objective of this study was to produce soluble enzyme-resistant dextrins by microwave heating of potato starch acidified with small amounts of hydrochloric and citric acids and to characterize their properties. Twenty five samples were initially made and their solubility was determined. Three samples with the highest water solubility were selected for physico-chemical (dextrose equivalent, molecular weight distribution, pasting characteristics, retrogradation tendency), total dietary fiber (TDF) analysis, and stability tests. TDF content averaged 25%. Enzyme-resistant dextrins practically did not paste, even at 20% samples concentration, and were characterized by low retrogradation tendency. The stability of the samples, expressed as a percentage increase of initial and final reducing sugar content, at low pH and during heating at low pH averaged 10% and 15% of the initial value, respectively. The results indicate that microwave heating could be an effective and efficient method of producing highly-soluble, low-viscous, and enzyme-resistant potato starch dextrins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Benzoic Acid and Chlorobenzoic Acids: Thermodynamic Study of the Pure Compounds and Binary Mixtures With Water.

PubMed

Reschke, Thomas; Zherikova, Kseniya V; Verevkin, Sergey P; Held, Christoph

2016-03-01

Benzoic acid is a model compound for drug substances in pharmaceutical research. Process design requires information about thermodynamic phase behavior of benzoic acid and its mixtures with water and organic solvents. This work addresses phase equilibria that determine stability and solubility. In this work, Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the phase behavior of aqueous and organic solutions containing benzoic acid and chlorobenzoic acids. Absolute vapor pressures of benzoic acid and 2-, 3-, and 4-chlorobenzoic acid from literature and from our own measurements were used to determine pure-component PC-SAFT parameters. Two binary interaction parameters between water and/or benzoic acid were used to model vapor-liquid and liquid-liquid equilibria of water and/or benzoic acid between 280 and 413 K. The PC-SAFT parameters and 1 binary interaction parameter were used to model aqueous solubility of the chlorobenzoic acids. Additionally, solubility of benzoic acid in organic solvents was predicted without using binary parameters. All results showed that pure-component parameters for benzoic acid and for the chlorobenzoic acids allowed for satisfying modeling phase equilibria. The modeling approach established in this work is a further step to screen solubility and to predict the whole phase region of mixtures containing pharmaceuticals. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Solubility and Diffusivity: Important Metrics in the Search for the Root Cause of Light- and Elevated Temperature-Induced Degradation

DOE PAGES

Jensen, Mallory A.; Morishige, Ashley E.; Chakraborty, Sagnik; ...

2018-02-02

Light- and elevated temperature-induced degradation (LeTID) is a detrimental effect observed under operating conditions in p-type multicrystalline silicon (mc-Si) solar cells. In this paper, we employ synchrotron-based techniques to study the dissolution of precipitates due to different firing processes at grain boundaries in LeTID-affected mc-Si. The synchrotron measurements show clear dissolution of collocated metal precipitates during firing. We compare our observations with degradation behavior in the same wafers. The experimental results are complemented with process simulations to provide insight into the change in bulk point defect concentration due to firing. Several studies have proposed that LeTID is caused by metal-richmore » precipitate dissolution during contact firing, and we find that the solubility and diffusivity are promising screening metrics to identify metals that are compatible with this hypothesis. While slower and less soluble elements (e.g., Fe and Cr) are not compatible according to our simulations, the point defect concentrations of faster and more soluble elements (e.g., Cu and Ni) increase after a high-temperature firing process, primarily due to emitter segregation rather than precipitate dissolution. Finally, these results are a useful complement to lifetime spectroscopy techniques, and can be used to evaluate additional candidates in the search for the root cause of LeTID.« less

Solubility and Diffusivity: Important Metrics in the Search for the Root Cause of Light- and Elevated Temperature-Induced Degradation

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

Jensen, Mallory A.; Morishige, Ashley E.; Chakraborty, Sagnik

Light- and elevated temperature-induced degradation (LeTID) is a detrimental effect observed under operating conditions in p-type multicrystalline silicon (mc-Si) solar cells. In this paper, we employ synchrotron-based techniques to study the dissolution of precipitates due to different firing processes at grain boundaries in LeTID-affected mc-Si. The synchrotron measurements show clear dissolution of collocated metal precipitates during firing. We compare our observations with degradation behavior in the same wafers. The experimental results are complemented with process simulations to provide insight into the change in bulk point defect concentration due to firing. Several studies have proposed that LeTID is caused by metal-richmore » precipitate dissolution during contact firing, and we find that the solubility and diffusivity are promising screening metrics to identify metals that are compatible with this hypothesis. While slower and less soluble elements (e.g., Fe and Cr) are not compatible according to our simulations, the point defect concentrations of faster and more soluble elements (e.g., Cu and Ni) increase after a high-temperature firing process, primarily due to emitter segregation rather than precipitate dissolution. Finally, these results are a useful complement to lifetime spectroscopy techniques, and can be used to evaluate additional candidates in the search for the root cause of LeTID.« less

Construction of the BAC Library of Small Abalone (Haliotis diversicolor) for Gene Screening and Genome Characterization.

PubMed

Jiang, Likun; You, Weiwei; Zhang, Xiaojun; Xu, Jian; Jiang, Yanliang; Wang, Kai; Zhao, Zixia; Chen, Baohua; Zhao, Yunfeng; Mahboob, Shahid; Al-Ghanim, Khalid A; Ke, Caihuan; Xu, Peng

2016-02-01

The small abalone (Haliotis diversicolor) is one of the most important aquaculture species in East Asia. To facilitate gene cloning and characterization, genome analysis, and genetic breeding of it, we constructed a large-insert bacterial artificial chromosome (BAC) library, which is an important genetic tool for advanced genetics and genomics research. The small abalone BAC library includes 92,610 clones with an average insert size of 120 Kb, equivalent to approximately 7.6× of the small abalone genome. We set up three-dimensional pools and super pools of 18,432 BAC clones for target gene screening using PCR method. To assess the approach, we screened 12 target genes in these 18,432 BAC clones and identified 16 positive BAC clones. Eight positive BAC clones were then sequenced and assembled with the next generation sequencing platform. The assembled contigs representing these 8 BAC clones spanned 928 Kb of the small abalone genome, providing the first batch of genome sequences for genome evaluation and characterization. The average GC content of small abalone genome was estimated as 40.33%. A total of 21 protein-coding genes, including 7 target genes, were annotated into the 8 BACs, which proved the feasibility of PCR screening approach with three-dimensional pools in small abalone BAC library. One hundred fifty microsatellite loci were also identified from the sequences for marker development in the future. The BAC library and clone pools provided valuable resources and tools for genetic breeding and conservation of H. diversicolor.

An internal pilot design for prospective cancer screening trials with unknown disease prevalence.

PubMed

Brinton, John T; Ringham, Brandy M; Glueck, Deborah H

2015-10-13

For studies that compare the diagnostic accuracy of two screening tests, the sample size depends on the prevalence of disease in the study population, and on the variance of the outcome. Both parameters may be unknown during the design stage, which makes finding an accurate sample size difficult. To solve this problem, we propose adapting an internal pilot design. In this adapted design, researchers will accrue some percentage of the planned sample size, then estimate both the disease prevalence and the variances of the screening tests. The updated estimates of the disease prevalence and variance are used to conduct a more accurate power and sample size calculation. We demonstrate that in large samples, the adapted internal pilot design produces no Type I inflation. For small samples (N less than 50), we introduce a novel adjustment of the critical value to control the Type I error rate. We apply the method to two proposed prospective cancer screening studies: 1) a small oral cancer screening study in individuals with Fanconi anemia and 2) a large oral cancer screening trial. Conducting an internal pilot study without adjusting the critical value can cause Type I error rate inflation in small samples, but not in large samples. An internal pilot approach usually achieves goal power and, for most studies with sample size greater than 50, requires no Type I error correction. Further, we have provided a flexible and accurate approach to bound Type I error below a goal level for studies with small sample size.

Likelihood of early detection of breast cancer in relation to false-positive risk in life-time mammographic screening: population-based cohort study.

PubMed

Otten, J D M; Fracheboud, J; den Heeten, G J; Otto, S J; Holland, R; de Koning, H J; Broeders, M J M; Verbeek, A L M

2013-10-01

Women require balanced, high-quality information when making an informed decision on screening benefits and harms before attending biennial mammographic screening. The cumulative risk of a false-positive recall and/or (small) screen-detected or interval cancer over 13 consecutive screening examinations for women aged 50 from the start of screening were estimated using data from the Nijmegen programme, the Netherlands. Women who underwent 13 successive screens in the period 1975-1976 had a 5.3% cumulative chance of a screen-detected cancer, with a 4.2% risk of at least one false-positive recall. The risk of being diagnosed with interval cancer was 3.7%. Two decades later, these estimates were 6.9%, 7.3% and 2.9%, respectively. The chance of detection of a small, favourable invasive breast cancer, anticipating a normal life-expectancy, rose from 2.3% to 3.7%. Extrapolation to digital screening mammography indicates that the proportion of false-positive results will rise to 16%. Dutch women about to participate in the screening programme can be reassured that the chance of false-positive recall in the Netherlands is relatively low. A new screening policy and improved mammography have increased the detection of an early screening carcinoma and lowering the risk of interval carcinoma.

Antiproliferative effects of small fruit juices on several cancer cell lines.

PubMed

Yoshizawa, Y; Kawaii, S; Urashima, M; Fukase, T; Sato, T; Tanaka, R; Murofushi, N; Nishimura, H

2000-01-01

Juices prepared from small fruits, mainly growing in the northern part of Japan, were studied in an attempt to explore the feasibility of an assay that screens cytotoxic properties. Screening of 43 small fruit juices indicated that Actinidia polygama Maxim., Rosa rugosa Thunb., Vaccinium smallii A. Gray and Sorbus sambucifolia Roem, strongly inhibited the proliferation of all cancer cell lines examined and yet these juices were substantially less cytotoxic toward normal human cell lines.

A novel small-molecule thienoquinolin urea transporter inhibitor acts as a potential diuretic.

PubMed

Li, Fei; Lei, Tianluo; Zhu, Juanjuan; Wang, Weiling; Sun, Yi; Chen, Jihui; Dong, Zixun; Zhou, Hong; Yang, Baoxue

2013-06-01

Urea transporters (UTs) are a family of membrane channel proteins that are specifically permeable to urea and play an important role in intrarenal urea recycling and in urine concentration. Using an erythrocyte osmotic lysis assay, we screened a small-molecule library for inhibitors of UT-facilitated urea transport. A novel class of thienoquinolin UT-B inhibitors were identified, of which PU-14 had potent inhibition activity on human, rabbit, rat, and mouse UT-B. The half-maximal inhibitory concentration of PU-14 on rat UT-B-mediated urea transport was ∼0.8 μmol/l, and it did not affect urea transport in mouse erythrocytes lacking UT-B but inhibited UT-A-type urea transporters, with 36% inhibition at 4 μmol/l. PU-14 showed no significant cellular toxicity at concentrations up to its solubility limit of 80 μmol/l. Subcutaneous delivery of PU-14 (at 12.5, 50, and 100 mg/kg) to rats caused an increase of urine output and a decrease of the urine urea concentration and subsequent osmolality without electrolyte disturbances and liver or renal damages. This suggests that PU-14 has a diuretic effect by urea-selective diuresis. Thus, PU-14 or its analogs might be developed as a new diuretic to increase renal fluid clearance in diseases associated with water retention without causing electrolyte imbalance. PU-14 may establish 'chemical knockout' animal models to study the physiological functions of UTs.

Drug delivery strategies for poorly water-soluble drugs.

PubMed

Fahr, Alfred; Liu, Xiangli

2007-07-01

The drug candidates coming from combinatorial chemistry research and/or the drugs selected from biologically based high-throughput screening are quite often very lipophilic, as these drug candidates exert their pharmacological action at or in biological membranes or membrane-associated proteins. This challenges drug delivery institutions in industry or academia to develop carrier systems for the optimal oral and parenteral administration of these drugs. To mention only a few of the challenges for this class of drugs: their oral bioavailability is poor and highly variable, and carrier development for parenteral administration is faced with problems, including the massive use of surface-active excipients for solubilisation. Formulation specialists are confronted with an even higher level of difficulties when these drugs have to be delivered site specifically. This article addresses the emerging formulation designs for delivering of poorly water-soluble drugs.

Small pulmonary nodules in baseline and incidence screening rounds of low-dose CT lung cancer screening

PubMed Central

Walter, Joan E.; Oudkerk, Matthijs

2017-01-01

Currently, lung cancer screening by low-dose computed tomography (LDCT) is widely recommended for high-risk individuals by US guidelines, but there still is an ongoing debate concerning respective recommendations for European countries. Nevertheless, the available data regarding pulmonary nodules released by lung cancer screening studies could improve future screening guidelines, as well as the clinical practice of incidentally detected pulmonary nodules on routine CT scans. Most lung cancer screening trials present results for baseline and incidence screening rounds separately, clustering pulmonary nodules initially found at baseline screening and newly detected pulmonary nodules after baseline screening together. This approach does not appreciate possible differences among pulmonary nodules detected at baseline and firstly detected at incidence screening rounds and is heavily influenced by methodological differences of the respective screening trials. This review intends to create a basis for assessing non-calcified pulmonary nodules detected during LDCT lung cancer screening in a more clinical relevant manner. The aim is to present data of non-calcified pulmonary baseline nodules and new non-calcified pulmonary incident nodules without clustering them together, thereby also simplifying translation to the clinical practice of incidentally detected pulmonary nodules. Small pulmonary nodules newly detected at incidence screening rounds of LDCT lung cancer screening may possess a greater lung cancer probability than pulmonary baseline nodules at a smaller size, which is essential for the development of new guidelines. PMID:28331823

pH-Dependent solubility and permeability criteria for provisional biopharmaceutics classification (BCS and BDDCS) in early drug discovery.

PubMed

Varma, Manthena V; Gardner, Iain; Steyn, Stefanus J; Nkansah, Paul; Rotter, Charles J; Whitney-Pickett, Carrie; Zhang, Hui; Di, Li; Cram, Michael; Fenner, Katherine S; El-Kattan, Ayman F

2012-05-07

The Biopharmaceutics Classification System (BCS) is a scientific framework that provides a basis for predicting the oral absorption of drugs. These concepts have been extended in the Biopharmaceutics Drug Disposition Classification System (BDDCS) to explain the potential mechanism of drug clearance and understand the effects of uptake and efflux transporters on absorption, distribution, metabolism, and elimination. The objective of present work is to establish criteria for provisional biopharmaceutics classification using pH-dependent passive permeability and aqueous solubility data generated from high throughput screening methodologies in drug discovery settings. The apparent permeability across monolayers of clonal cell line of Madin-Darby canine kidney cells, selected for low endogenous efflux transporter expression, was measured for a set of 105 drugs, with known BCS and BDDCS class. The permeability at apical pH 6.5 for acidic drugs and at pH 7.4 for nonacidic drugs showed a good correlation with the fraction absorbed in human (Fa). Receiver operating characteristic (ROC) curve analysis was utilized to define the permeability class boundary. At permeability ≥ 5 × 10(-6) cm/s, the accuracy of predicting Fa of ≥ 0.90 was 87%. Also, this cutoff showed more than 80% sensitivity and specificity in predicting the literature permeability classes (BCS), and the metabolism classes (BDDCS). The equilibrium solubility of a subset of 49 drugs was measured in pH 1.2 medium, pH 6.5 phosphate buffer, and in FaSSIF medium (pH 6.5). Although dose was not considered, good concordance of the measured solubility with BCS and BDDCS solubility class was achieved, when solubility at pH 1.2 was used for acidic compounds and FaSSIF solubility was used for basic, neutral, and zwitterionic compounds. Using a cutoff of 200 μg/mL, the data set suggested a 93% sensitivity and 86% specificity in predicting both the BCS and BDDCS solubility classes. In conclusion, this study identified pH-dependent permeability and solubility criteria that can be used to assign provisional biopharmaceutics class at early stage of the drug discovery process. Additionally, such a classification system will enable discovery scientists to assess the potential limiting factors to oral absorption, as well as help predict the drug disposition mechanisms and potential drug-drug interactions.

Comprehensive Study on the Impact of the Cation Alkyl Side Chain Length on the Solubility of Water in Ionic Liquids.

PubMed

Kurnia, Kiki A; Neves, Catarina M S S; Freire, Mara G; Santos, Luís M N B F; Coutinho, João A P

2015-10-01

A comprehensive study on the phase behaviour of two sets of ionic liquids (ILs) and their interactions with water is here presented through combining experimental and theoretical approaches. The impact of the alkyl side chain length and the cation symmetry on the water solubility in the asymmetric [C N- 1 C 1 im][NTf 2 ] and symmetric [C N- 1 C N- 1 im][NTf 2 ] series of ILs ( N up to 22), from 288.15 K to 318.15 K and at atmospheric pressure, was studied. The experimental data reveal that the solubility of water in ILs with an asymmetric cation is higher than in those with the symmetric isomer. Several trend shifts on the water solubility as a function of the alkyl side chain length were identified, namely at [C 6 C 1 im][NTf 2 ] for asymmetric ILs and at [C 4 C 4 im][NTf 2 ] and [C 7 C 7 im][NTf 2 ] for the symmetric ILs. To complement the experimental data and to further investigate the molecular-level mechanisms behind the dissolution process, Density Functional Theory calculations, using the Conductor-like Screening Model for Real Solvents (COSMO-RS) and the Electrostatic potential-derived CHelpG, were performed. The COSMO-RS model is able to qualitatively predict water solubility as function of temperature and alkyl chain lengths of both symmetric and asymmetric cations. Furthermore, the model is also capable to predict the somewhat higher water solubility in the asymmetric cation, as well as the trend shift as function of alkyl chain lengths experimentally observed. Both COSMO-RS and the electrostatic potential-derived CHelpG show that the interactions of water and the IL cation take place on the IL polar region, namely on the aromatic head and adjacent methylene groups what explains the differences in water solubility observed for cations with different chain lengths. Furthermore, the CHelpG calculations for the isolated cations in the gas phase indicates that the trend shift of water solubility as function of alkyl chain lengths and the difference of water solubility in symmetric may also result from the partial positive charge distribution/contribution of the cation.

Mapping a disordered portion of the Brz2001-binding site on a plant monooxygenase, DWARF4, using a quartz-crystal microbalance biosensor-based T7 phage display.

PubMed

Takakusagi, Yoichi; Manita, Daisuke; Kusayanagi, Tomoe; Izaguirre-Carbonell, Jesus; Takakusagi, Kaori; Kuramochi, Kouji; Iwabata, Kazuki; Kanai, Yoshihiro; Sakaguchi, Kengo; Sugawara, Fumio

2013-04-01

In small-molecule/protein interaction studies, technical difficulties such as low solubility of small molecules or low abundance of protein samples often restrict the progress of research. Here, we describe a quartz-crystal microbalance (QCM) biosensor-based T7 phage display in combination use with a receptor-ligand contacts (RELIC) bioinformatics server for application in a plant Brz2001/DWARF4 system. Brz2001 is a brassinosteroid biosynthesis inhibitor in the less-soluble triazole series of compounds that targets DWARF4, a cytochrome P450 (Cyp450) monooxygenase containing heme and iron. Using a Brz2001 derivative that has higher solubility in 70% EtOH and forms a self-assembled monolayer on gold electrode, we selected 34 Brz2001-recognizing peptides from a 15-mer T7 phage-displayed random peptide library using a total of four sets of one-cycle biopanning. The RELIC/MOTIF program revealed continuous and discontinuous short motifs conserved within the 34 Brz2001-selected 15-mer peptide sequences, indicating the increase of information content for Brz2001 recognition. Furthermore, an analysis of similarity between the 34 peptides and the amino-acid sequence of DWARF4 using the RELIC/MATCH program generated a similarity plot and a cluster diagram of the amino-acid sequence. Both of these data highlighted an internally located disordered portion of a catalytic site on DWARF4, indicating that this portion is essential for Brz2001 recognition. A similar trend was also noted by an analysis using another 26 Brz2001-selected peptides, and not observed using the 27 gold electrode-recognizing control peptides, demonstrating the reproducibility and specificity of this method. Thus, this affinity-based strategy enables high-throughput detection of the small-molecule-recognizing portion on the target protein, which overcomes technical difficulties such as sample solubility or preparation that occur when conventional methods are used.

Improving physical properties via C-H oxidation: chemical and enzymatic approaches.

PubMed

Michaudel, Quentin; Journot, Guillaume; Regueiro-Ren, Alicia; Goswami, Animesh; Guo, Zhiwei; Tully, Thomas P; Zou, Lufeng; Ramabhadran, Raghunath O; Houk, Kendall N; Baran, Phil S

2014-11-03

Physicochemical properties constitute a key factor for the success of a drug candidate. Whereas many strategies to improve the physicochemical properties of small heterocycle-type leads exist, complex hydrocarbon skeletons are more challenging to derivatize because of the absence of functional groups. A variety of C-H oxidation methods have been explored on the betulin skeleton to improve the solubility of this very bioactive, yet poorly water-soluble, natural product. Capitalizing on the innate reactivity of the molecule, as well as the few molecular handles present on the core, allowed oxidations at different positions across the pentacyclic structure. Enzymatic oxidations afforded several orthogonal oxidations to chemical methods. Solubility measurements showed an enhancement for many of the synthesized compounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protein Solubility and Protein Homeostasis: A Generic View of Protein Misfolding Disorders

PubMed Central

Vendruscolo, Michele; Knowles, Tuomas P.J.; Dobson, Christopher M.

2011-01-01

According to the “generic view” of protein aggregation, the ability to self-assemble into stable and highly organized structures such as amyloid fibrils is not an unusual feature exhibited by a small group of peptides and proteins with special sequence or structural properties, but rather a property shared by most proteins. At the same time, through a wide variety of techniques, many of which were originally devised for applications in other disciplines, it has also been established that the maintenance of proteins in a soluble state is a fundamental aspect of protein homeostasis. Taken together, these advances offer a unified framework for understanding the molecular basis of protein aggregation and for the rational development of therapeutic strategies based on the biological and chemical regulation of protein solubility. PMID:21825020

Identifying the preferred RNA motifs and chemotypes that interact by probing millions of combinations.

PubMed

Tran, Tuan; Disney, Matthew D

2012-01-01

RNA is an important therapeutic target but information about RNA-ligand interactions is limited. Here, we report a screening method that probes over 3,000,000 combinations of RNA motif-small molecule interactions to identify the privileged RNA structures and chemical spaces that interact. Specifically, a small molecule library biased for binding RNA was probed for binding to over 70,000 unique RNA motifs in a high throughput solution-based screen. The RNA motifs that specifically bind each small molecule were identified by microarray-based selection. In this library-versus-library or multidimensional combinatorial screening approach, hairpin loops (among a variety of RNA motifs) were the preferred RNA motif space that binds small molecules. Furthermore, it was shown that indole, 2-phenyl indole, 2-phenyl benzimidazole and pyridinium chemotypes allow for specific recognition of RNA motifs. As targeting RNA with small molecules is an extremely challenging area, these studies provide new information on RNA-ligand interactions that has many potential uses.

Identifying the Preferred RNA Motifs and Chemotypes that Interact by Probing Millions of Combinations

PubMed Central

Tran, Tuan; Disney, Matthew D.

2012-01-01

RNA is an important therapeutic target but information about RNA-ligand interactions is limited. Here we report a screening method that probes over 3,000,000 combinations of RNA motif-small molecule interactions to identify the privileged RNA structures and chemical spaces that interact. Specifically, a small molecule library biased for binding RNA was probed for binding to over 70,000 unique RNA motifs in a high throughput solution-based screen. The RNA motifs that specifically bind each small molecule were identified by microarray-based selection. In this library-versus-library or multidimensional combinatorial screening approach, hairpin loops (amongst a variety of RNA motifs) were the preferred RNA motif space that binds small molecules. Furthermore, it was shown that indole, 2-phenyl indole, 2-phenyl benzimidazole, and pyridinium chemotypes allow for specific recognition of RNA motifs. Since targeting RNA with small molecules is an extremely challenging area, these studies provide new information on RNA-ligand interactions that has many potential uses. PMID:23047683

Molecular Simulation of Gas Solubility in Nitrile Butadiene Rubber.

PubMed

Khawaja, M; Sutton, A P; Mostofi, A A

2017-01-12

Molecular simulation is used to compute the solubility of small gases in nitrile butadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of local free volume is also investigated. The acrylonitrile content of the polymer is altered to examine its influence on the solubility of helium, CO 2 , and H 2 O, and the solubilities of polar gases are found to be enhanced relative to those of nonpolar gases, in qualitative agreement with experiment. To probe this phenomenon further, the solubilities are decomposed into contributions from the neighborhoods of different atoms, using a Voronoi cell construction, and a strong bias is found for CO 2 and H 2 O in particular to be situated near nitrogen sites in the elastomer. Temperature is shown to suppress the solubility of CO 2 and H 2 O but to increase that of helium. Increasing pressure is found to suppress the solubility of all gases but at different rates, according to a balance between their molecular sizes and electrostatic interactions with the polymer. These results are relevant to the use of NBR seals at elevated temperatures and pressures, such as in oil and gas wells.

Impact of the counterion on the solubility and physicochemical properties of salts of carboxylic acid drugs.

PubMed

David, S E; Timmins, P; Conway, B R

2012-01-01

Salt formation is a widely used approach to improve the physicochemical and solid state properties of an active pharmaceutical ingredient. In order to better understand the relationships between the active drug, the selected counterion and the resultant salt form, crystalline salts were formed using four different carboxylic acid drugs and a closely related series of amine counterions. Thirty-six related crystalline salts were prepared, characterized and the relationship between solubility and dissolution behaviour and other properties of the salt and the counterion studied. Salts of four model acid drugs, gemfibrozil, flurbiprofen, ibuprofen and etodolac were prepared using the counterions butylamine, hexylamine, octylamine, benzylamine, cyclohexylamine, tert-butylamine, 2-amino-2-methylpropan-1-ol, 2-amino-2-methylpropan-1,3-diol and tris(hydroxymethyl)aminomethane. Salt formation was confirmed, the salts were characterized and their corresponding solubilities determined and rationalized with respect to the counterions' properties. The properties of the salt highly dependent on the nature of the counterion and, although there is considerable variation, some general conclusion can be drawn. For the alkyl amines series, increasing chain length leads to a reduction in solubility across all the acidic drugs studied and a reduction in melting point, thus contradicting simplistic relationships between solubility and melting point. Small, compact counterions consistently produce crystalline salts with high melting point accompanied with a modest improvement in solubility and the nature of hydrogen bonding between the ions has a major impact on the solubility.

Understanding the high solubility of CO2 in an ionic liquid with the tetracyanoborate anion.

PubMed

Babarao, Ravichandar; Dai, Sheng; Jiang, De-en

2011-08-18

The ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate, [emim][B(CN)(4)], shows greater CO(2) solubility than several popular ionic liquids (ILs) of different anions including [emim]bis(trifluoromethylsulfonyl)imide [emim][Tf(2)N]. Herein, both classical molecular dynamics simulation and quantum mechanical calculations were used to understand the high solubility of CO(2) in the [emim][B(CN)(4)] IL. We found that the solubility is dictated by the cation-anion interaction, while the CO(2)-anion interaction plays a secondary role. The atom-atom radial distribution functions (RDFs) between cation and anion show weaker interaction in [emim][B(CN)(4)] than in [emim][Tf(2)N]. A good correlation is observed between gas-phase cation-anion interaction energy with CO(2) solubility at 1 bar and 298 K, suggesting that weaker cation-anion interaction leads to higher CO(2) solubility. MD simulation of CO(2) in the ILs showed that CO(2) is closer to the anion than to the cation and that it interacts more strongly with [B(CN)(4)] than with [Tf(2)N]. Moreover, a higher volume expansion is observed in [emim][B(CN)(4)] than in [emim][Tf(2)N] at different mole fractions of CO(2). These results indicate that [B(CN)(4)] as a small and highly symmetric anion is unique in giving a high CO(2) solubility by interacting weakly with the cation and thus allowing easy creation of cavity for close contact with CO(2).

Controlled release systems containing solid dispersions: strategies and mechanisms.

PubMed

Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh; Park, Jun Bom; Lee, Beom-Jin

2011-10-01

In addition to a number of highly soluble drugs, most new chemical entities under development are poorly water-soluble drugs generally characterized by an insufficient dissolution rate and a small absorption window, leading to the low bioavailability. Controlled-release (CR) formulations have several potential advantages over conventional dosage forms, such as providing a uniform and prolonged therapeutic effect to improve patient compliance, reducing the frequency of dosing, minimizing the number of side effects, and reducing the strength of the required dose while increasing the effectiveness of the drug. Solid dispersions (SD) can be used to enhance the dissolution rate of poorly water-soluble drugs and to sustain the drug release by choosing an appropriate carrier. Thus, a CR-SD comprises both functions of SD and CR for poorly water-soluble drugs. Such CR dosage forms containing SD provide an immediately available dose for an immediate action followed by a gradual and continuous release of subsequent doses to maintain the plasma concentration of poorly water-soluble drugs over an extended period of time. This review aims to summarize all currently known aspects of controlled release systems containing solid dispersions, focusing on the preparation methods, mechanisms of action and characterization of physicochemical properties of the system.

Detection of colloidal silver chloride near solubility limit

NASA Astrophysics Data System (ADS)

Putri, K. Y.; Adawiah, R.

2018-03-01

Detection of nanoparticles in solution has been made possible by several means; one of them is laser-induced breakdown detection (LIBD). LIBD is able to distinguish colloids of various sizes and concentrations. This technique has been used in several solubility studies. In this study, the formation of colloids in a mixed system of silver nitrate and sodium chloride was observed by acoustic LIBD. Silver chloride has low solubility limit, therefore LIBD measurement is appropriate. Silver and chloride solutions with equal concentrations, set at below and above the solubility of silver chloride as the expected solid product, were mixed and the resulting colloids were observed. The result of LIBD measurement showed that larger particles were present as more silver and chloride introduced. However, once the concentrations exceeded the solubility limit of silver chloride, the detected particle size seemed to be decreasing, hence suggested the occurrence of coprecipitation process. This phenomenon indicated that the ability of LIBD to detect even small changes in colloid amounts might be a useful tool in study on formation and stability of colloids, i.e. to confirm whether nanoparticles synthesis has been successfully performed and whether the system is stable or not.

Enhanced Aqueous Solubility of Long Wavelength Voltage-Sensitive Dyes by Covalent Attachment of Polyethylene Glycol

PubMed Central

Patrick, Michael J.; Ernst, Lauren A.; Waggoner, Alan S.; Thai, Dung; Salama, Guy

2011-01-01

Long wavelength voltage-sensitive dyes (VSDs) called Pittsburgh (PGH) dyes were recently synthesized by coupling various heterocyclic groups to a styryl-thiophene intermediate forming extended, partially rigidized chromophores. Unlike most styryl VSDs, dyes with a sulfonic acid anchor directly attached to the chromophore showed no solvatochromic absorption shifts. The limited water solubility of many long wavelength VSDs requires the use of surfactants to transport the dye through aqueous media and effectively label biological membranes. Here, we tested the chemical substitution of the sulfonic acid moiety with polyethyleneglycol (PEG) chains ranging from MW 750 to 5000, to overcome the poor solubility of VSDs while retaining their properties as VSDs. The chemical synthesis of PGH dyes and their PEG derivatives are described. The PEG-derivatives were soluble in aqueous solutions (> 1 mM) and still reported membrane potential changes. In frog and mouse hearts, the voltage sensitivity (ΔF/F per action potential) and spectral properties of PEG dyes were the same as the sulfonated analogs. Thus, the solubility of VSDs can be considerably improved with small polyethyleneglycol chains and can provide an effective approach to improve staining of excitable tissues and optical recordings of membrane potential. PMID:17912389

Photochemical dissolution of Turkish lignites in tetralin at different irradiation power and reaction times

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

F. Karacan; T. Torul

2007-08-15

The effect of the power of ultraviolet (UV) irradiation on the tetrahydrofuran (THF) solubles yield (the total soluble product) and the soluble product distribution of the dissolution of Turkish lignites (Beypazari and Tuncbilek lignite) in tetralin at ambient temperatures has been investigated. The lignite samples were exposed to UV irradiation for 1, 2, 3, 5, and 10 days in the power of irradiation ranging from 0 to 180 W at 60 W intervals. The yields of THF solubles and oils increased with increasing irradiation power and time. The optimum irradiation power depends on the irradiation time to obtain the highestmore » degradation products. However, the yield of degradation products depends also on the lignite type. The largest fraction obtained from lignites by photochemical energy is oil. While the yields of THF solubles and oils sharply increased with irradiation power at longer reaction times, the yields of asphaltenes (AS) slightly decreased. Increasing oil yields is relatively larger when AS yields tend to decrease. These trends of AS and oil yields are ascribable to conversion of AS to oils at higher power. Small changes were observed in the PAS yields under all conditions. 27 refs., 5 figs., 1 tab.« less

An Introduction to Lipid Analysis in the Cell Biology Laboratory.

ERIC Educational Resources Information Center

Schuh, Timothy J.

2002-01-01

Explains a thin-layer chromatography (TLC) experiment that allows students to study complex mixtures of lipids using small volumes. Uses a water-soluble dye to stain lipids that is fast and safe. (YDS)

Environmental Containment Property Estimation Using OSARs in an Expert System

DTIC Science & Technology

1990-09-14

point , melting point , aqueous solubility, octanol/water partition coefficient, vapor pressure, soil/water sorption coefficients, Henry’s Law constants...name, boiling point , melting point , or molecular weight, and the ability to transfer to any of the PEP modules. The chemical property database screen is...Yalkowski et al., 1980): log Ssupercooled liquid = log Ssolid = 0.01(MP - 25) (13) where MP is the compound’s melting point in *C. Property/protiny

Engineering of Paraoxonases for Pre- and Post-treatment of Intoxication by a Broad Spectrum of Nerve Agents and Pesticides

DTIC Science & Technology

2014-08-01

chemical warfare nerve agents (CWNA). Enzymes identified in these screens should be capable of catalytically neutralizing the target agent under...soluble form. 4. Large-scale production of selected enzyme candidates, and their kinetic, structural and pharmacological evaluation 6...employed, with an enzyme protein concentration of 0.5-2 mM in the assay cuvette, the activity measured was indistinguishable from the rate of

Biosensor-based small molecule fragment screening with biolayer interferometry

NASA Astrophysics Data System (ADS)

Wartchow, Charles A.; Podlaski, Frank; Li, Shirley; Rowan, Karen; Zhang, Xiaolei; Mark, David; Huang, Kuo-Sen

2011-07-01

Biosensor-based fragment screening is a valuable tool in the drug discovery process. This method is advantageous over many biochemical methods because primary hits can be distinguished from non-specific or non-ideal interactions by examining binding profiles and responses, resulting in reduced false-positive rates. Biolayer interferometry (BLI), a technique that measures changes in an interference pattern generated from visible light reflected from an optical layer and a biolayer containing proteins of interest, is a relatively new method for monitoring small molecule interactions. The BLI format is based on a disposable sensor that is immersed in 96-well or 384-well plates. BLI has been validated for small molecule detection and fragment screening with model systems and well-characterized targets where affinity constants and binding profiles are generally similar to those obtained with surface plasmon resonsance (SPR). Screens with challenging targets involved in protein-protein interactions including BCL-2, JNK1, and eIF4E were performed with a fragment library of 6,500 compounds, and hit rates were compared for these targets. For eIF4E, a protein containing a PPI site and a nucleotide binding site, results from a BLI fragment screen were compared to results obtained in biochemical HTS screens. Overlapping hits were observed for the PPI site, and hits unique to the BLI screen were identified. Hit assessments with SPR and BLI are described.

Suboptimal Exposure to Facial Expressions When Viewing Video Messages From a Small Screen: Effects on Emotion, Attention, and Memory

ERIC Educational Resources Information Center

Ravaja, Niklas; Kallinen, Kari; Saari, Timo; Keltikangas-Jarvinen, Liisa

2004-01-01

The authors examined the effects of suboptimally presented facial expressions on emotional and attentional responses and memory among 39 young adults viewing video (business news) messages from a small screen. Facial electromyography (EMG) and respiratory sinus arrhythmia were used as physiological measures of emotion and attention, respectively.…

When "Promotoras" and Technology Meet: A Qualitative Analysis of "Promotoras'" Use of Small Media to Increase Cancer Screening among South Texas Latinos

ERIC Educational Resources Information Center

Arvey, Sarah R.; Fernandez, Maria E.; LaRue, Denise M.; Bartholomew, L. Kay

2012-01-01

Computer-based multimedia technologies can be used to tailor health messages, but "promotoras" (Spanish-speaking community health workers) rarely use these tools. "Promotoras" delivered health messages about colorectal cancer screening to medically underserved Latinos in South Texas using two small media formats: a…

Effect of welding fume solubility on lung macrophage viability and function in vitro.

PubMed

Antonini, J M; Lawryk, N J; Murthy, G G; Brain, J D

1999-11-26

It was shown previously that fumes generated from stainless steel (SS) welding induced more pneumotoxicity and were cleared from the lungs at a slower rate than fumes collected from mild steel (MS) welding. These differences in response may be attributed to the metal composition of SS and MS welding fumes. In this study, fumes with vastly different metal profiles were collected during gas metal arc (GMA) or flux-covered manual metal arc (MMA) welding using two different consumable electrodes, SS or MS. The collected samples were suspended in saline, incubated for 24 h at 37 degrees C, and centrifuged. The supernatant (soluble components) and pellets (insoluble particulates) were separated, and their effects on lung macrophage viability and the release of reactive oxygen species (ROS) by macrophages were examined in vitro. The soluble MMA-SS sample was shown to be the most cytotoxic to macrophages and to have the greatest effect on their function as compared to the GMA-SS and GMA-MS fumes. Neither the soluble nor insoluble forms of the GMA-MS sample had any marked effect on macrophage viability. The flux-covered MMA-SS fume was found to be much more water soluble as compared to either the GMA-SS or the GMA-MS fumes. The soluble fraction of the MMA-SS samples was comprised almost entirely of Cr. The small fraction of the GMA-MS sample that was soluble contained Mn with little Fe, while a more complex mixture was observed in the soluble portion of the GMA-SS sample, which contained Mn, Ni, Fe, Cr, and Cu. Data show that differences in the solubility of welding fumes influence the viability and ROS production of macrophages. The presence of soluble metals, such as Fe, Cr, Ni, Cu, and Mn, and the complexes formed by these different metals are likely important in the pulmonary responses observed after welding fume exposure.

Enoxaparin for the prevention of preeclampsia and intrauterine growth restriction in women with a history: a randomized trial.

PubMed

Groom, Katie M; McCowan, Lesley M; Mackay, Laura K; Lee, Arier C; Said, Joanne M; Kane, Stefan C; Walker, Susan P; van Mens, Thijs E; Hannan, Natalie J; Tong, Stephen; Chamley, Larry W; Stone, Peter R; McLintock, Claire

2017-03-01

Preeclampsia and small-for-gestational-age pregnancy are major causes of maternal and perinatal morbidity and mortality. Women with a previous pregnancy affected by these conditions are at an increased risk of recurrence in a future pregnancy. Past trials evaluating the effect of low-molecular-weight heparin for the prevention of recurrence of preeclampsia and small-for-gestational-age pregnancy have shown conflicting results with high levels of heterogeneity displayed when trials were compared. We sought to assess the effectiveness of enoxaparin in addition to high-risk care for the prevention of preeclampsia and small-for-gestational-age pregnancy in women with a history of these conditions. This was an open-label randomized controlled trial in 5 tertiary care centers in 3 countries. Women with a viable singleton pregnancy were invited to participate between >6 +0 and <16 +0 weeks if deemed to be at high risk of preeclampsia and/or small for gestational age based on their obstetric history. Eligible participants were randomly assigned in a 1-to-1 ratio to standard high-risk care or standard high-risk care plus enoxaparin 40 mg (4000 IU) by subcutaneous injection daily from recruitment until 36 +0 weeks or delivery, whichever occurred sooner. Standard high-risk care was defined as care coordinated by a high-risk antenatal clinic service, aspirin 100 mg daily until 36 +0 weeks, and-for women with prior preeclampsia-calcium 1000-1500 mg daily until 36 +0 weeks. In a subgroup of participants serum samples were taken at recruitment and at 20 and 30 weeks' gestation and later analyzed for soluble fms-like tyrosine kinase-1, soluble endoglin, endothelin-1, placental growth factor, and soluble vascular cell adhesion molecule 1. The primary outcome was a composite of preeclampsia and/or small-for-gestational-age <5th customized birthweight percentile. All data were analyzed on an intention-to-treat basis. The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12609000699268). Between July 26, 2010, and Oct. 28, 2015, a total of 156 participants were enrolled and included in the analysis. In all, 149 participants were included in the outcome analysis (72 receiving standard high-risk care plus enoxaparin and 77 receiving standard high-risk care only). Seven women who miscarried <16 weeks' gestation were excluded. The majority of participants (151/156, 97%) received aspirin. The addition of enoxaparin had no effect on the rate of preeclampsia and/or small-for-gestational-age <5th customized birthweight percentile: enoxaparin 18/72 (25%) vs no enoxaparin 17/77 (22.1%) (odds ratio, 1.19; 95% confidence interval, 0.53-2.64). There was also no difference in any of the secondary outcome measures. Levels of soluble fms-like tyrosine kinase-1 and soluble endoglin increased among those who developed preeclampsia, but there was no difference in levels of these antiangiogenic factors (nor any of the other serum analytes measured) among those treated with enoxaparin compared to those receiving standard high-risk care only. The use of enoxaparin in addition to standard high-risk care does not reduce the risk of recurrence of preeclampsia and small-for-gestational-age infants in a subsequent pregnancy. Copyright © 2017 Elsevier Inc. All rights reserved.

The Axolotl Fibula as a Model for the Induction of Regeneration across Large Segment Defects in Long Bones of the Extremities

PubMed Central

Chen, Xiaoping; Song, Fengyu; Jhamb, Deepali; Li, Jiliang; Bottino, Marco C.; Palakal, Mathew J.; Stocum, David L.

2015-01-01

We tested the ability of the axolotl (Ambystoma mexicanum) fibula to regenerate across segment defects of different size in the absence of intervention or after implant of a unique 8-braid pig small intestine submucosa (SIS) scaffold, with or without incorporated growth factor combinations or tissue protein extract. Fractures and defects of 10% and 20% of the total limb length regenerated well without any intervention, but 40% and 50% defects failed to regenerate after either simple removal of bone or implanting SIS scaffold alone. By contrast, scaffold soaked in the growth factor combination BMP-4/HGF or in protein extract of intact limb tissue promoted partial or extensive induction of cartilage and bone across 50% segment defects in 30%-33% of cases. These results show that BMP-4/HGF and intact tissue protein extract can promote the events required to induce cartilage and bone formation across a segment defect larger than critical size and that the long bones of axolotl limbs are an inexpensive model to screen soluble factors and natural and synthetic scaffolds for their efficacy in stimulating this process. PMID:26098852

Structure–activity relationships of imidazole-derived 2-[N-carbamoylmethyl-alkylamino]acetic acids, dual binders of human insulin-degrading enzyme

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

Charton, Julie; Gauriot, Marion; Totobenazara, Jane

Insulin degrading enzyme (IDE) is a zinc metalloprotease that degrades small amyloid peptides such as amyloid-â and insulin. So far the dearth of IDE-specific pharmacological inhibitors impacts the understanding of its role in the physiopathology of Alzheimer's disease, amyloid-â clearance, and its validation as a potential therapeutic target. Hit 1 was previously discovered by high-throughput screening. Here we describe the structure-activity study, that required the synthesis of 48 analogues. We found that while the carboxylic acid, the imidazole and the tertiary amine were critical for activity, the methyl ester was successfully optimized to an amide or a 1,2,4-oxadiazole. Along withmore » improving their activity, compounds were optimized for solubility, lipophilicity and stability in plasma and microsomes. The docking or co-crystallization of some compounds at the exosite or the catalytic site of IDE provided the structural basis for IDE inhibition. The pharmacokinetic properties of best compounds 44 and 46 were measured in vivo. As a result, 44 (BDM43079) and its methyl ester precursor 48 (BDM43124) are useful chemical probes for the exploration of IDE's role.« less

Enhancement of Perfluoropolyether Boundary Lubrication Performance

NASA Technical Reports Server (NTRS)

Jones, W. R., Jr.; Ajayi, O. O.; Wedeven, L. D.

1996-01-01

A ball bearing simulator operating under starved conditions was used to perform screening tests to evaluate the boundary lubrication performance of a branched perfluoropolyether (PFPE), K-143 AB. Several approaches to enhance boundary lubrication were studied. These included: (1) soluble boundary additives, (2) bearing surface modifications, (3) 'run-in' surface films, and (4) ceramic bearing components. In addition, results were compared with two non-perfluorinated liquid lubricant formulations. Based on these tests, the following tentative conclusions can be made: (1) Substantial improvements in boundary lubrication performance were observed with a beta-diketone boundary additive and a tricresyl phosphate (TCP) liquid surface pretreatment, (2) the use of rough Si3N4 balls (R(sub a) = 40 micro-inch) also provided increases in test duration, but with concomitant abrasive wear, (3) moderate improvements were seen with two boundary additives (a phosphine and a phosphatriazine) and a neat (100%) fluid (a carboxylic acid terminated PFPE); and small improvements with surface pretreatments with synthetic hydrocarbons, a polytetrafluoroethylene (PTFE) coating, and TiC coated 440 C and smooth Si3N4 balls (R(sub a) = 1 micro-inch), and (4) two non-PFPE lubricant formulations (a polyalphaolefin (PAO) and synthetic hydrocarbon) yielded substantial improvements.

Structure-activity relationships of Imidazole-derived 2-[N-carbamoylmethyl-alkylamino]acetic acids, dual binders of human Insulin-Degrading Enzyme

PubMed Central

Charton, Julie; Gauriot, Marion; Totobenazara, Jane; Hennuyer, Nathalie; Dumont, Julie; Bosc, Damien; Marechal, Xavier; Elbakali, Jamal; Herledan, Adrien; Wen, Xiaoan; Ronco, Cyril; Gras-Masse, Helene; Heninot, Antoine; Pottiez, Virginie; Landry, Valerie; Staels, Bart; Liang, Wenguang G.; Leroux, Florence; Tang, Wei-Jen; Deprez, Benoit; Deprez-Poulain, Rebecca

2015-01-01

Insulin degrading enzyme (IDE) is a zinc metalloprotease that degrades small amyloid peptides such as amyloid-β and insulin. So far the dearth of IDE-specific pharmacological inhibitors impacts the understanding of its role in the physiopathology of Alzheimer’s disease, amyloid-β clearance, and its validation as a potential therapeutic target. Hit 1 was previously discovered by high-throughput screening. Here we describe the structure-activity study, that required the synthesis of 48 analogues. We found that while the carboxylic acid, the imidazole and the tertiary amine were critical for activity, the methyl ester was successfully optimized to an amide or a 1,2,4-oxadiazole. Along with improving their activity, compounds were optimized for solubility, lipophilicity and stability in plasma and microsomes. The docking or co-crystallization of some compounds at the exosite or the catalytic site of IDE provided the structural basis for IDE inhibition. The pharmacokinetic properties of best compounds 44 and 46 were measured in vivo. As a result, 44 (BDM43079) and its methyl ester precursor 48 (BDM43124) are useful chemical probes for the exploration of IDE’s role. PMID:25489670

Biomarker Guided Therapy in Chronic Heart Failure

PubMed Central

Bektas, Sema

2015-01-01

This review article addresses the question of whether biomarker-guided therapy is ready for clinical implementation in chronic heart failure. The most well-known biomarkers in heart failure are natriuretic peptides, namely B-type natriuretic peptide (BNP) and N-terminal pro-BNP. They are well-established in the diagnostic process of acute heart failure and prediction of disease prognosis. They may also be helpful in screening patients at risk of developing heart failure. Although studied by 11 small- to medium-scale trials resulting in several positive meta-analyses, it is less well-established whether natriuretic peptides are also helpful for guiding chronic heart failure therapy. This uncertainty is expressed by differences in European and American guideline recommendations. In addition to reviewing the evidence surrounding the use of natriuretic peptides to guide chronic heart failure therapy, this article gives an overview of the shortcomings of the trials, how the results may be interpreted and the future directions necessary to fill the current gaps in knowledge. Therapy guidance in chronic heart failure using other biomarkers has not been prospectively tested to date. Emerging biomarkers, such as galectin-3 and soluble ST2, might be useful in this regard, as suggested by several post-hoc analyses. PMID:28785440

Isolation and characterization of a novel human scFv inhibiting EGFR vIII expressing cancers.

PubMed

Rahbarnia, Leila; Farajnia, Safar; Babaei, Hossein; Majidi, Jafar; Dariushnejad, Hassan; Hosseini, Mohammad Kazem

2016-12-01

EGFRvIII, a mutant form of epidermal growth factor receptor is highly expressed in glioblastoma, carcinoma of the breast, ovary, and lung but not in normal cells. This tumor specific antigen has emerged as a promising candidate for antibody based therapy of several cancers. The aim of the present study was isolation and characterization of a human single chain antibody against EGFRvIII as a promising target for cancer therapy. For this, a synthetic peptide corresponding to EGFRvIII protein was used for screening the naive human scFv phage library. Selection was performed using a novel screening strategy for enrichment of rare specific clones. After five rounds of screening, six positive scFv clones against EGFRvIII were selected using monoclonal phage ELISA, among them, a clone with an amber mutation in VH CDR2 coding sequence showed higher reactivity. The mutation was corrected through site directed mutagenesis and then scFv fragment was expressed after subcloning into the bacterial expression vector. Expression in BL21 pLysS resulted in a highly soluble scFv appeared in soluble fraction of E. coli lysate. Bioinformatic in silico analysis between scFv and EGFRvIII sequences confirmed specific binding of desired scFv to EGFRvIII in CDR regions. The specific reactivity of the purified scFv with native EGFRvIII was confirmed by cell based ELISA and western blot. In conclusion, human anti- EGFRvIII scFv isolated from a scFv phage library displayed high reactivity with EGFRvIII. The scFv isolated in this study can be the groundwork for developing more effective diagnostic and therapeutic agents against EGFRvIII expressing cancers. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Genetic Testing in Screening Patients With Stage IB-IIIA Non-Small Cell Lung Cancer That Has Been or Will Be Removed by Surgery (The ALCHEMIST Screening Trial)

ClinicalTrials.gov

2018-06-29

Large Cell Lung Carcinoma; Lung Adenocarcinoma; Stage IB Non-Small Cell Lung Carcinoma AJCC v7; Stage IB Squamous Cell Lung Carcinoma AJCC v7; Stage II Non-Small Cell Lung Cancer AJCC v7; Stage II Squamous Cell Lung Carcinoma AJCC v7; Stage IIA Non-Small Cell Lung Carcinoma AJCC v7; Stage IIA Squamous Cell Lung Carcinoma AJCC v7; Stage IIB Non-Small Cell Lung Carcinoma AJCC v7; Stage IIB Squamous Cell Lung Carcinoma AJCC v7; Stage IIIA Non-Small Cell Lung Cancer AJCC v7; Stage IIIA Squamous Cell Lung Carcinoma AJCC v7

The impact of mobile phone screen size on user comprehension of health information.

PubMed

Alghamdi, Ebtisam; Yunus, Faisel; Househ, Mowafa

2013-01-01

Within the field of mobile health, there is little research conducted on the impacts of mobile health technologies and applications on user comprehension of health content. In this study, we examine the difference between small, medium and large screen mobile phone that affect the user comprehension of health content. We designed an experimental study where 33 users read the contents of a health application on different mobile phone screen sizes. Each participant was timed, tracked for correctness, and gave ratings for both readability and satisfaction on each task. In addition, they were asked some questions about the contents. Results show that there was no significant impact of the screen size on user comprehension of the contents. However, it was found that participants with small screen size took longer to read the health contents.

Carbon Dioxide: The Other Planetary Fluid

NASA Astrophysics Data System (ADS)

Glaser, S.; Gamez, D.; Shock, E.

2016-12-01

Cometary and interstellar ices have carbon dioxide to water mole ratios of up to 0.3. When melted, such high levels of carbon dioxide cannot all be dissolved in the aqueous phase and instead partition into a CO2-rich (carbonic) fluid. This implies that during the accretion and formation of planetary systems carbonic fluids are not only possible, but common. In fact, they make up the atmosphere of Venus, are found bubbling out of Champagne Vent in the Pacific Ocean, and are documented by metamorphic fluid inclusions. Examination of phase diagrams reveals the conditions where carbonic fluids will exist or predominate. Carbonic fluids are predicted to exist in Earth's subduction zones and under the ice of small ocean worlds. CO2 had previously been shown to completely dissolve into NH­­3­-H­­2O oceans on small icy bodies by forming ammonium carbonate, but the newer measurements of CO2­ abundances indicate that not all of the CO2 can partition into the aqueous fluid as ammonium carbonate. The remaining CO2 would necessarily form a separate carbonic fluid making it likely that liquid CO2 would be a major oceanic component on some small icy bodies. The enhanced solubility of nonpolar and slightly polar organic compounds in carbonic fluids relative to aqueous fluids means that generation, transport, and deposition processes can be greatly enhanced in those cases where carbonic fluids occur. As an example, the solubility of benzoic acid, a polar compound, is about an order of magnitude greater in carbonic than in aqueous fluids, which is surprising given that water is a polar solvent and carbon dioxide is a nonpolar solvent. Anthracene, a nonpolar compound, has an even greater solubility difference between carbonic and aqueous fluids at approximately four orders of magnitude. Highly polar compounds, including most of the building blocks of life, are more soluble in aqueous fluids than in carbonic fluids. The solubility difference of organic molecules in carbonic fluids relative to aqueous fluids determines the distribution of the building blocks of life in planetary systems. Partitioning of organics into a carbonic fluid may be the mechanism of removing biochemically irrelevant molecules from the aqueous phase and enabling the emergence of life.

Effect of confinement in nano-porous materials on the solubility of a supercritical gas

NASA Astrophysics Data System (ADS)

Hu, Yaofeng; Huang, Liangliang; Zhao, Shuangliang; Liu, Honglai; Gubbins, Keith E.

2016-11-01

By combining Gibbs Ensemble Monte Carlo simulations and density functional theory, we investigate the influence of confinement in a slit-shaped carbon pore on the solubility of a supercritical solute gas in a liquid solvent. In the cases studied here, competing adsorption of the solvent and solute determines whether the solubility is enhanced or suppressed for larger pores. We find that the solubility in the confined system is strongly dependent on pore width, and that molecular packing effects are important for small pore widths. In addition, the solubility decreases on increase in the temperature, as for the bulk mixture, but the rate of decrease is greater in the pore due to a decrease in the partial molar enthalpy of the solute in the pore; this effect becomes greater as pore width is decreased. The solubility is increased on increasing the bulk pressure of the gas in equilibrium with the pore, and obeys Henry's law at lower pressures. However, the Henry constant differs significantly from that for the bulk mixture, and the range of pressure over which Henry's law applies is reduced relative to that for the bulk mixture. The latter observation indicates that solute-solute interactions become more important in the pore than for the bulk at a given bulk pressure. Finally, we note that different authors use different definitions of the solubility in pores, leading to some confusion over the reported phenomenon of 'oversolubility'. We recommend that solubility be defined as the overall mole fraction of solute in the pores, since it takes into account the increase in density of the solvent in the pores, and avoids ambiguity in the definition of the pore volume.

Equivalence principle implications of modified gravity models

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

Hui, Lam; Nicolis, Alberto; Stubbs, Christopher W.

2009-11-15

Theories that attempt to explain the observed cosmic acceleration by modifying general relativity all introduce a new scalar degree of freedom that is active on large scales, but is screened on small scales to match experiments. We demonstrate that if such screening occurs via the chameleon mechanism, such as in f(R) theory, it is possible to have order unity violation of the equivalence principle, despite the absence of explicit violation in the microscopic action. Namely, extended objects such as galaxies or constituents thereof do not all fall at the same rate. The chameleon mechanism can screen the scalar charge formore » large objects but not for small ones (large/small is defined by the depth of the gravitational potential and is controlled by the scalar coupling). This leads to order one fluctuations in the ratio of the inertial mass to gravitational mass. We provide derivations in both Einstein and Jordan frames. In Jordan frame, it is no longer true that all objects move on geodesics; only unscreened ones, such as test particles, do. In contrast, if the scalar screening occurs via strong coupling, such as in the Dvali-Gabadadze-Porrati braneworld model, equivalence principle violation occurs at a much reduced level. We propose several observational tests of the chameleon mechanism: 1. small galaxies should accelerate faster than large galaxies, even in environments where dynamical friction is negligible; 2. voids defined by small galaxies would appear larger compared to standard expectations; 3. stars and diffuse gas in small galaxies should have different velocities, even if they are on the same orbits; 4. lensing and dynamical mass estimates should agree for large galaxies but disagree for small ones. We discuss possible pitfalls in some of these tests. The cleanest is the third one where the mass estimate from HI rotational velocity could exceed that from stars by 30% or more. To avoid blanket screening of all objects, the most promising place to look is in voids.« less

High-throughput screening of small molecules in miniaturized mammalian cell-based assays involving post-translational modifications.

PubMed

Stockwell, B R; Haggarty, S J; Schreiber, S L

1999-02-01

Fully adapting a forward genetic approach to mammalian systems requires efficient methods to alter systematically gene products without prior knowledge of gene sequences, while allowing for the subsequent characterization of these alterations. Ideally, these methods would also allow function to be altered in a temporally controlled manner. We report the development of a miniaturized cell-based assay format that enables a genetic-like approach to understanding cellular pathways in mammalian systems using small molecules, rather than mutations, as the source of gene-product alterations. This whole-cell immunodetection assay can sensitively detect changes in specific cellular macromolecules in high-density arrays of mammalian cells. Furthermore, it is compatible with screening large numbers of small molecules in nanoliter to microliter culture volumes. We refer to this assay format as a 'cytoblot', and demonstrate the use of cytoblotting to monitor biosynthetic processes such as DNA synthesis, and post-translational processes such as acetylation and phosphorylation. Finally, we demonstrate the applicability of these assays to natural-product screening through the identification of marine sponge extracts exhibiting genotype-specific inhibition of 5-bromodeoxyuridine incorporation and suppression of the anti-proliferative effect of rapamycin. We show that cytoblots can be used for high-throughput screening of small molecules in cell-based assays. Together with small-molecule libraries, the cytoblot assay can be used to perform chemical genetic screens analogous to those used in classical genetics and thus should be applicable to understanding a wide variety of cellular processes, especially those involving post-transitional modifications.

Soluble Dietary Fiber Can Protect the Gastrointestinal Mucosa Against Nonsteroidal Anti-Inflammatory Drugs in Mice.

PubMed

Satoh, Hiroshi; Urushidani, Tetsuro

2016-07-01

Nonsteroidal anti-inflammatory drug (NSAID)-induced small intestinal damage is a serious problem in patients, but effective therapy is not available at present. The effects of feeding conditions and dietary fiber (DF) on NSAID-induced gastrointestinal lesions were examined in mice. NSAIDs (indomethacin, diclofenac, loxoprofen, aspirin) were administered to male mice in various feeding conditions. Gastrointestinal lesions were examined 24 h after NSAID dosing. Regular diets, dietary-fiber-free diet (FFD), and diets supplemented with various types of DF were given to mice. NSAIDs produced marked ulcers and perforations selectively in the gastric antrum when they were administered after feeding of regular diet for 2 h after a 22-h fast. When NSAIDs, except for aspirin, were administered in unfasted conditions, they caused marked lesions in the small intestine. When mice were given FFD, antral ulcers and intestinal lesions induced by indomethacin (30 mg/kg, s.c.) markedly decreased, but when cellulose, an insoluble DF, was added to FFD, the lesions appeared again. The addition of pectin, a soluble DF, to regular diet containing 4.1 % crude fiber significantly inhibited the formation of antral ulcers as well as intestinal lesions caused by indomethacin or diclofenac (100 mg/kg, s.c.). The results indicated that NSAIDs given after feeding of diet produced ulcers selectively in the gastric antrum. The severity of the gastrointestinal lesions depended on the concentration of soluble or insoluble DF in food. Our results suggest that soluble DF such as pectin may be a safe means for protecting the gastrointestinal mucosa against NSAIDs.

Design and optimization of self-nanoemulsifying drug delivery systems for improved bioavailability of cyclovirobuxine D

PubMed Central

Ke, Zhongcheng; Hou, Xuefeng; Jia, Xiao-bin

2016-01-01

Background The main purpose of this research was to design a self-nanoemulsifying drug delivery system (SNEDDS) for improving the bioavailability of cyclovirobuxine D as a poorly water-soluble drug. Materials and methods Solubility trials, emulsifying studies, and pseudo-ternary phase diagrams were used to screen the SNEDDS formulations. The optimized drug-loaded SNEDDS was prepared at a mass ratio of 3:24:38:38 for cyclovirobuxine D, oleic acid, Solutol SH15, and propylene glycol, respectively. The optimized formulation was characterized in terms of physicochemical and pharmacokinetic parameters compared with marketed cyclovirobuxine D tablets. Results The optimized cyclovirobuxine-D-loaded SNEDDS was spontaneously dispersed to form a nanoemulsion with a globule size of 64.80±3.58 nm, which exhibited significant improvement of drug solubility, rapid absorption rate, and enhanced area under the curve, together with increased permeation and decreased efflux. Fortunately, there was a nonsignificant cytotoxic effect toward Caco-2 cells. The relative bioavailability of SNEDDS was 200.22% in comparison with market tablets, in rabbits. Conclusion SNEDDS could be a potential candidate for an oral dosage form of cyclovirobuxine D with improved bioavailability. PMID:27418807

48 CFR 719.271-6 - Small business screening procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... acquisition threshold shall be screened by SDB, with the exception of: (1) Class set-asides and those... the original and 2 copies to SDB within one working day of receipt by the contracting activity of a... appropriate) prior to submittal to SDB. (c) Screening of Form USAID 1410-14 by SDB. (1) SDB will screen the...

48 CFR 719.271-6 - Small business screening procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... acquisition threshold shall be screened by SDB, with the exception of: (1) Class set-asides and those... the original and 2 copies to SDB within one working day of receipt by the contracting activity of a... appropriate) prior to submittal to SDB. (c) Screening of Form USAID 1410-14 by SDB. (1) SDB will screen the...

48 CFR 719.271-6 - Small business screening procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... acquisition threshold shall be screened by SDB, with the exception of: (1) Class set-asides and those... the original and 2 copies to SDB within one working day of receipt by the contracting activity of a... appropriate) prior to submittal to SDB. (c) Screening of Form USAID 1410-14 by SDB. (1) SDB will screen the...

48 CFR 719.271-6 - Small business screening procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... acquisition threshold shall be screened by SDB, with the exception of: (1) Class set-asides and those... the original and 2 copies to SDB within one working day of receipt by the contracting activity of a... appropriate) prior to submittal to SDB. (c) Screening of Form USAID 1410-14 by SDB. (1) SDB will screen the...

University of Texas Southwestern Medical Center (UTSW): Lung Cancer Oncogenotype-Selective Drug Target Discovery (Natural Products Focus) | Office of Cancer Genomics

Cancer.gov

The goal of this project is to use small molecules and RNAi to functionally define subtypes of non-small cell lung cancer (NSCLC) using a panel of cell lines prepared and molecularly annotated by Drs. John Minna and Adi Gazdar. Experimental Approaches Lung Cancer Natural Products Screening/Chemical Library Screening

The Study of Learners' Preference for Visual Complexity on Small Screens of Mobile Computers Using Neural Networks

ERIC Educational Resources Information Center

Wang, Lan-Ting; Lee, Kun-Chou

2014-01-01

The vision plays an important role in educational technologies because it can produce and communicate quite important functions in teaching and learning. In this paper, learners' preference for the visual complexity on small screens of mobile computers is studied by neural networks. The visual complexity in this study is divided into five…

University of Texas Southwestern Medical Center: Lung Cancer Oncogenotype-Selective Drug Target Discovery (Natural Products Focus) | Office of Cancer Genomics

Cancer.gov

The goal of this project is to use small molecules and RNAi to functionally define subtypes of non-small cell lung cancer (NSCLC) using a panel of cell lines prepared and molecularly annotated by Drs. John Minna and Adi Gazdar. Experimental Approaches Lung Cancer Natural Products Screening/Chemical Library Screening

High-quality and small-capacity e-learning video featuring lecturer-superimposing PC screen images

NASA Astrophysics Data System (ADS)

Nomura, Yoshihiko; Murakami, Michinobu; Sakamoto, Ryota; Sugiura, Tokuhiro; Matsui, Hirokazu; Kato, Norihiko

2006-10-01

Information processing and communication technology are progressing quickly, and are prevailing throughout various technological fields. Therefore, the development of such technology should respond to the needs for improvement of quality in the e-learning education system. The authors propose a new video-image compression processing system that ingeniously employs the features of the lecturing scene. While dynamic lecturing scene is shot by a digital video camera, screen images are electronically stored by a PC screen image capturing software in relatively long period at a practical class. Then, a lecturer and a lecture stick are extracted from the digital video images by pattern recognition techniques, and the extracted images are superimposed on the appropriate PC screen images by off-line processing. Thus, we have succeeded to create a high-quality and small-capacity (HQ/SC) video-on-demand educational content featuring the advantages: the high quality of image sharpness, the small electronic file capacity, and the realistic lecturer motion.

Pilot test of a peer-led small-group video intervention to promote mammography screening among Chinese American immigrants

PubMed Central

Maxwell, Annette E.; Wang, Judy H.; Young, Lucy; Crespi, Catherine M.; Mistry, Ritesh; Sudan, Madhuri; Bastani, Roshan

2010-01-01

This study evaluated the feasibility, acceptability and potential effect of a small-group video intervention led by trained Chinese American lay educators who recruited Chinese American women not up to date on mammography screening. Nine lay educators conducted 14 “breast health tea time workshops” in community settings and private homes that started with watching a culturally tailored video promoting screening followed by a question and answer session and distribution of print materials. Many group attendees did not have health insurance or a regular doctor, had low levels of income and were not proficient in English. Forty-four percent of the attendees reported receipt of a mammogram within 6 months after the small-group session with higher odds of screening among women who had lived in the U.S. less than 10% of their lifetime. Four of the educators were very interested in conducting another group session in the next 6 months. PMID:20720095

Influence of pH, particle size and crystal form on dissolution behaviour of engineered nanomaterials.

PubMed

Avramescu, M-L; Rasmussen, P E; Chénier, M; Gardner, H D

2017-01-01

Solubility is a critical component of physicochemical characterisation of engineered nanomaterials (ENMs) and an important parameter in their risk assessments. Standard testing methodologies are needed to estimate the dissolution behaviour and biodurability (half-life) of ENMs in biological fluids. The effect of pH, particle size and crystal form on dissolution behaviour of zinc metal, ZnO and TiO 2 was investigated using a simple 2 h solubility assay at body temperature (37 °C) and two pH conditions (1.5 and 7) to approximately frame the pH range found in human body fluids. Time series dissolution experiments were then conducted to determine rate constants and half-lives. Dissolution characteristics of investigated ENMs were compared with those of their bulk analogues for both pH conditions. Two crystal forms of TiO 2 were considered: anatase and rutile. For all compounds studied, and at both pH conditions, the short solubility assays and the time series experiments consistently showed that biodurability of the bulk analogues was equal to or greater than biodurability of the corresponding nanomaterials. The results showed that particle size and crystal form of inorganic ENMs were important properties that influenced dissolution behaviour and biodurability. All ENMs and bulk analogues displayed significantly higher solubility at low pH than at neutral pH. In the context of classification and read-across approaches, the pH of the dissolution medium was the key parameter. The main implication is that pH and temperature should be specified in solubility testing when evaluating ENM dissolution in human body fluids, even for preliminary (tier 1) screening.

Application of hanging drop technique to optimize human IgG formulations.

PubMed

Li, Guohua; Kasha, Purna C; Late, Sameer; Banga, Ajay K

2010-01-01

The purpose of this work is to assess the hanging drop technique in screening excipients to develop optimal formulations for human immunoglobulin G (IgG). A microdrop of human IgG and test solution hanging from a cover slide and undergoing vapour diffusion was monitored by a stereomicroscope. Aqueous solutions of IgG in the presence of different pH, salt concentrations and excipients were prepared and characterized. Low concentration of either sodium/potassium phosphate or McIlvaine buffer favoured the solubility of IgG. Addition of sucrose favoured the stability of this antibody while addition of NaCl caused more aggregation. Antimicrobial preservatives were also screened and a complex effect at different buffer conditions was observed. Dynamic light scattering, differential scanning calorimetry and size exclusion chromatography studies were performed to further validate the results. In conclusion, hanging drop is a very easy and effective approach to screen protein formulations in the early stage of formulation development.

Is the full potential of the biopharmaceutics classification system reached?

PubMed

Bergström, Christel A S; Andersson, Sara B E; Fagerberg, Jonas H; Ragnarsson, Gert; Lindahl, Anders

2014-06-16

In this paper we analyse how the biopharmaceutics classification system (BCS) has been used to date. A survey of the literature resulted in a compilation of 242 compounds for which BCS classes were reported. Of these, 183 compounds had been reported to belong to one specific BCS class whereas 59 compounds had been assigned to multiple BCS classes in different papers. Interestingly, a majority of the BCS class 2 compounds had fraction absorbed (FA) values >85%, indicating that they were completely absorbed after oral administration. Solubility was computationally predicted at pH 6.8 for BCS class 2 compounds to explore the impact of the pH of the small intestine, where most of the absorption occurs, on the solubility. In addition, the solubilization capacity of lipid aggregates naturally present in the intestine was studied computationally and experimentally for a subset of 12 compounds. It was found that all acidic compounds with FA>85% were completely dissolved in the pH of the small intestine. Further, lipids at the concentration used in fasted state simulated intestinal fluid (FaSSIF) dissolved the complete dose given of the most lipophilic (logD6.5>3) compounds studied. Overall, biorelevant dissolution media (pure buffer of intestinal pH or FaSSIF) identified that for 20 of the 29 BCS class 2 compounds with FA>85% the complete dose given orally would be dissolved. These results indicate that a more relevant pH restriction for acids and/or dissolution medium with lipids present better forecast solubility-limited absorption in vivo than the presently used BCS solubility criterion. The analysis presented herein further strengthens the discussion on the requirement of more physiologically relevant dissolution media for the in vitro solubility classification performed to reach the full potential of the BCS. Copyright © 2013 Elsevier B.V. All rights reserved.

Zircon: Free Energy of Formation by Aqueous Solubility Measurements at High T and P

NASA Astrophysics Data System (ADS)

Newton, R. C.; Manning, C. E.; Hanchar, J. M.

2002-12-01

We measured the silica solubility at 800 °C, 12 kbar, of small (~0.5 mg) limpid euhedral zircon crystals grown by a flux-melt method (Hanchar et al., Am. Min., 86, 667, 2001). Incongruent solution occurs according to ZrSiO4 = ZrO2 + SiO2,aq. Zircon lost ~0.1 mg after exposure of 1-2 mg of zircon to ~32 mg H2O in welded Pt envelopes for 90-120 hr in piston-cylinder apparatus using NaCl-graphite furnaces. The average solubility was 0.0645+/-0.007 molal (m), or a mole fraction (XS) of 0.00116. Reversibility was established by rerunning the baddeleyite-coated zircons with a fluid initially slightly SiO2-oversaturated, as determined by the forward experiments, resulting in weight gains of the composite crystals. Similar runs on sintered ZrO2 compacts yielded spontaneous surface nucleation and growth of zircons up to 1 mm. Concentrations were corrected for a small, measured solubility of ZrO2 (0.001 m). Nonideality of aqueous silica was calculated assuming that SiO2,aq consists of a mixture of monomers and dimers (Zotov and Keppler (Chem. Geol., 184, 71, 2002; Newton and Manning, GCA, in press). Our zircon solubility and that of quartz at the same conditions (XS=0.02634, Manning, GCA, 58, 4831, 1994) give activity coefficients at the two concentrations of 0.730 and 0.255, respectively. The activity coefficients and concentrations yield the free energy of formation of zircon from the oxides at 800 °C, 12 kbar of -18.46+/-0.96 kJ/mol, which translates to -11.91+/-0.96 kJ/mol at 800 °C, 1 bar. Our value is compatible with previous estimates based on experiment (Schuiling et al., Am. Min., 61, 166, 1976) and high-T oxide-melt calorimetry (Ellison and Navrotsky, J. Am. Ceram. Soc., 75, 1430, 1992), but is four times more precise than these estimates.

Stages of Small Cell Lung Cancer

MedlinePlus

... Lung Cancer Prevention Lung Cancer Screening Research Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Small Cell Lung Cancer Go to Health Professional Version Key ...

PD-1/PD-L1 inhibitor screening of caffeoylquinic acid compounds using surface plasmon resonance spectroscopy.

PubMed

Han, Ya; Gao, Yaning; He, Tian; Wang, Daidong; Guo, Ning; Zhang, Xiaotian; Chen, Shizhong; Wang, Hong

2018-04-15

Following the FDA approval of three monoclonal antibodies of PD-1/PD-L1, this pathway has become a promising target for cancer treatment. Currently small-molecule inhibitors have not been extensively investigated, and appropriate screening methods for such inhibitors are urgently required. In this study, surface plasmon resonance (SPR) technology was used to evaluate the affinity and competitive inhibition of nine caffeoylquinic acid compounds (CQAs) against PD-1/PD-L1. As a result, four small molecules including 1-CQA, 3-CQA, 4-CQA and 5-CQA were determined as PD-1/PD-L1 inhibitors. This study provided an efficient method for screening small-molecule inhibitors targeting PD-1/PD-L1 pathway. Copyright © 2018. Published by Elsevier Inc.

Multidentate-Protected Colloidal Gold Nanocrystals: pH Control of Cooperative Precipitation and Surface Layer Shedding

PubMed Central

Kairdolf, Brad A.; Nie, Shuming

2011-01-01

Colloidal gold nanocrystals with broad size tunability and unusual pH-sensitive properties have been synthesized by using multidentate polymer ligands. Containing both carboxylic functional groups and sterically hindered aliphatic chains, the multidentate ligands are able to both reduce gold precursors and to stabilize gold nanoclusters during nucleation and growth. The “as-synthesized” nanocrystals are protected by an inner coordinating layer and an outer polymer layer, and are soluble in water and polar solvents. When the solution pH is lowered by just 0.6 units (from pH 4.85 to 4.25), the particles undergo a dramatic cooperative transition from being soluble to insoluble, allowing rapid isolation, purification, and redispersion of the multidentate-protected nanocrystals. A surprise finding is that when a portion of the surface carboxylate groups is neutralized by protonation, the particles irreversibly shed their outer polymer layer and become soluble in nonpolar organic solvents. Further, the multidentate polymer coatings are permeable to small organic molecules, in contrast to tightly packed self-assembled monolayers of alkanethiols on gold. These insights are important towards the design of “smart” imaging and therapeutic nanoparticles that are activated by small pH changes in the tumor interstitial space or endocytic organelles. PMID:21510704

Transport of dissolved gases through unsaturated porous media

NASA Astrophysics Data System (ADS)

Maryshev, B. S.

2017-06-01

The natural porous media (e.g. soil, sand, peat etc.) usually are partially saturated by groundwater. The saturation of soil depends on hydrostatic pressure which is linearly increased with depth. Often some gases (e.g. nitrogen, oxygen, carbon dioxide, methane etc.) are dissolved into the groundwater. The solubility of gases is very small because of that two assumptions is applied: I. The concentration of gas is equal to solubility, II. Solubility depends only on pressure (for isothermal systems). In this way some part of dissolved gas transfers from the solution to the bubble phase. The gas bubbles are immovably trapped in a porous matrix by surface-tension forces and the dominant mechanism of transport of gas mass becomes the diffusion of gas molecules through the liquid. If the value of water content is small then the transport of gas becomes slow and gas accumulates into bubble phase. The presence of bubble phase additionally decreases the water content and slows down the transport. As result the significant mass of gas should be accumulated into the massif of porous media. We derive the transport equations and find the solution which is demonstrated the accumulation of gases. The influence of saturation, porosity and filtration velocity to accumulation process is investigated and discussed.

Design and Discovery of N -(2-Methyl-5'-morpholino-6'-((tetrahydro-2 H -pyran-4-yl)oxy)-[3,3'-bipyridin]-5-yl)-3-(trifluoromethyl)benzamide (RAF709): A Potent, Selective, and Efficacious RAF Inhibitor Targeting RAS Mutant Cancers

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

Nishiguchi, Gisele A.; Rico, Alice; Tanner, Huw

RAS oncogenes have been implicated in >30% of human cancers, all representing high unmet medical need. The exquisite dependency on CRAF kinase in KRAS mutant tumors has been established in genetically engineered mouse models and human tumor cells. To date, many small molecule approaches are under investigation to target CRAF, yet kinase-selective and cellular potent inhibitors remain challenging to identify. Herein, we describe 14 (RAF709) [Aversa, Biaryl amide compounds as kinase inhibitors and their preparation. WO 2014151616, 2014], a selective B/C RAF inhibitor, which was developed through a hypothesis-driven approach focusing on drug-like properties. A key challenge encountered in themore » medicinal chemistry campaign was maintaining a balance between good solubility and potent cellular activity (suppression of pMEK and proliferation) in KRAS mutant tumor cell lines. We investigated the small molecule crystal structure of lead molecule 7 and hypothesized that disruption of the crystal packing would improve solubility, which led to a change from N-methylpyridone to a tetrahydropyranyl oxy-pyridine derivative. 14 proved to be soluble, kinase selective, and efficacious in a KRAS mutant xenograft model.« less

Expression and purification of recombinant proteins in Escherichia coli tagged with a small metal-binding protein from Nitrosomonas europaea.

PubMed

Vargas-Cortez, Teresa; Morones-Ramirez, Jose Ruben; Balderas-Renteria, Isaias; Zarate, Xristo

2016-02-01

Escherichia coli is still the preferred organism for large-scale production of recombinant proteins. The use of fusion proteins has helped considerably in enhancing the solubility of heterologous proteins and their purification with affinity chromatography. Here, the use of a small metal-binding protein (SmbP) from Nitrosomonas europaea is described as a new fusion protein for protein expression and purification in E. coli. Fluorescent proteins tagged at the N-terminal with SmbP showed high levels of solubility, compared with those of maltose-binding protein and glutathione S-transferase, and low formation of inclusion bodies. Using commercially available IMAC resins charged with Ni(II), highly pure recombinant proteins were obtained after just one chromatography step. Proteins may be purified from the periplasm of E. coli if SmbP contains the signal sequence at the N-terminal. After removal of the SmbP tag from the protein of interest, high-yields are obtained since SmbP is a protein of just 9.9 kDa. The results here obtained suggest that SmbP is a good alternative as a fusion protein/affinity tag for the production of soluble recombinant proteins in E. coli. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure-Based Virtual Screening of Commercially Available Compound Libraries.

PubMed

Kireev, Dmitri

2016-01-01

Virtual screening (VS) is an efficient hit-finding tool. Its distinctive strength is that it allows one to screen compound libraries that are not available in the lab. Moreover, structure-based (SB) VS also enables an understanding of how the hit compounds bind the protein target, thus laying ground work for the rational hit-to-lead progression. SBVS requires a very limited experimental effort and is particularly well suited for academic labs and small biotech companies that, unlike pharmaceutical companies, do not have physical access to quality small-molecule libraries. Here, we describe SBVS of commercial compound libraries for Mer kinase inhibitors. The screening protocol relies on the docking algorithm Glide complemented by a post-docking filter based on structural protein-ligand interaction fingerprints (SPLIF).

Application of Fourier transform infrared spectroscopy for monitoring short-chain free fatty acids in Swiss cheese.

PubMed

Koca, N; Rodriguez-Saona, L E; Harper, W J; Alvarez, V B

2007-08-01

Short-chain free fatty acids (FFA) are important sources of cheese flavor and have been reported to be indicators for assessing quality. The objective of this research was to develop a simple and rapid screening tool for monitoring the short-chain FFA contents in Swiss cheese by using Fourier transform infrared spectroscopy (FTIR). Forty-four Swiss cheese samples were evaluated by using a MIRacle three-reflection diamond attenuated total reflectance (ATR) accessory. Two different sampling techniques were used for FTIR/ATR measurement: direct measurement of Swiss cheese slices (approximately 0.5 g) and measurement of a water-soluble fraction of cheese. The amounts of FFA (propionic, acetic, and butyric acids) in the water-soluble fraction of samples were analyzed by gas chromatography-flame ion-ization detection as a reference method. Calibration models for both direct measurement and the water-soluble fraction of cheese were developed based on a cross-validated (leave-one-out approach) partial least squares regression by using the regions of 3,000 to 2,800, 1,775 to 1,680, and 1,500 to 900 cm(-1) for short-chain FFA in cheese. Promising performance statistics were obtained for the calibration models of both direct measurement and the water-soluble fraction, with improved performance statistics obtained from the water-soluble extract, particularly for propionic acid. Partial least squares models generated from FTIR/ATR spectra by direct measurement of cheeses gave standard errors of cross-validation of 9.7 mg/100 g of cheese for propionic acid, 9.3 mg/100 g of cheese for acetic acid, and 5.5 mg/100 g of cheese for butyric acid, and correlation coefficients >0.9. Standard error of cross-validation values for the water-soluble fraction were 4.4 mg/100 g of cheese for propionic acid, 9.2 mg/100 g of cheese for acetic acid, and 5.2 mg/100 g of cheese for butyric acid with correlation coefficients of 0.98, 0.95, and 0.92, respectively. Infrared spectroscopy and chemometrics accurately and precisely predicted the short-chain FFA content in Swiss cheeses and in the water-soluble fraction of the cheese.

Crystallization of M-CSF.alpha.

DOEpatents

Pandit, Jayvardhan; Jancarik, Jarmila; Kim, Sung-Hou; Koths, Kirston; Halenbeck, Robert; Fear, Anna Lisa; Taylor, Eric; Yamamoto, Ralph; Bohm, Andrew

1999-01-01

The present invention is directed to methods for crystallizing macrophage colony stimulating factor (M-CSF) and to a crystalline M-CSF produced thereby. The present invention is also directed to methods for designing and producing M-CSF agonists and antagonists using information derived from the crystallographic structure of M-CSF. The invention is also directed to methods for screening M-CSF agonists and antagonists. In addition, the present invention is directed to an isolated, purified, soluble and functional M-CSF receptor.

High-content screening of small compounds on human embryonic stem cells.

PubMed

Barbaric, Ivana; Gokhale, Paul J; Andrews, Peter W

2010-08-01

Human ES (embryonic stem) cells and iPS (induced pluripotent stem) cells have been heralded as a source of differentiated cells that could be used in the treatment of degenerative diseases, such as Parkinson's disease or diabetes. Despite the great potential for their use in regenerative therapy, the challenge remains to understand the basic biology of these remarkable cells, in order to differentiate them into any functional cell type. Given the scale of the task, high-throughput screening of agents and culture conditions offers one way to accelerate these studies. The screening of small-compound libraries is particularly amenable to such high-throughput methods. Coupled with high-content screening technology that enables simultaneous assessment of multiple cellular features in an automated and quantitative way, this approach is proving powerful in identifying both small molecules as tools for manipulating stem cell fates and novel mechanisms of differentiation not previously associated with stem cell biology. Such screens performed on human ES cells also demonstrate the usefulness of human ES/iPS cells as cellular models for pharmacological testing of drug efficacy and toxicity, possibly a more imminent use of these cells than in regenerative medicine.

Phytotoxicity of water-soluble substances from alfalfa and barley soil extracts on four crop species.

PubMed

Read, J J; Jensen, E H

1989-02-01

Problems associated with continuously planting alfalfa (Medicago saliva L.) or seeding to thicken depleted alfalfa stands may be due to autotoxicity, an intraspecific form of allelopathy. A bioassay approach was utilized to characterize the specificity and chemical nature of phytotoxins in extracts of alfalfa soils as compared to fallow soil or soil where a cereal was the previous crop. In germination chamber experiments, water-soluble substances present in methanol extracts of soil cropped to alfalfa or barley (Hordeum vulgare L.) decreased seedling root length of alfalfa L-720, winter wheat (Triticum aestivum L. Nugaines) and radish (Raphanus sativa L. Crimson Giant). Five days after germination, seedling dry weights of alfalfa and radish in alfalfa soil extracts were lower compared to wheat or red clover (Trifolium pralense L. Kenland). Growth of red clover was not significantly reduced by soil extracts from cropped soil. Extracts of crop residue screened from soil cropped to alfalfa or barley significantly reduced seedling root length; extracts of alfalfa residue caused a greater inhibition of seedling dry weight than extracts of barely residue. A phytotoxic, unidentified substance present in extracts of crop residue screened from alfalfa soil, which inhibited seedling root length of alfalfa, was isolated by thin-layer chromatography (TLC). Residues from a soil cropped continuously to alfalfa for 10 years had the greatest phytotoxic activity.

Assessment of oral bioavailability enhancing approaches for SB-247083 using flow-through cell dissolution testing as one of the screens.

PubMed

Perng, Cherng-Yih; Kearney, Albert S; Palepu, Nagesh R; Smith, Brian R; Azzarano, Leonard M

2003-01-02

SB-247083 is a potent, nonpeptidic, orally active, ETA-selective, endothelin receptor antagonist. The diacid form and three salts (monoarginine, diarginine and disodium) of SB-247083 were evaluated during the pre-clinical phase of development. The developability attributes (i.e. hygroscopicity, thermal behavior, aqueous solubility, and drug-excipient compatibility) of these compounds were evaluated. In addition to these attributes, the flow-through cell (FTC) dissolution testing (using USP Apparatus 4) was used as a screening technique to evaluate several SB-247083 formulations of the diacid and its salts. FTC dissolution testing offers two distinct advantages over the more traditional static-condition dissolution testing: (1) maintenance of sink conditions; and (2) the ability to change the dissolution medium during a dissolution run. The former advantage is especially important for poorly aqueous soluble drugs having associated dissolution-rate-limitations, and the latter advantage allows one to more closely simulate the pH gradient associated with transit through the GI tract. Based on the comparative dissolution data, three formulations were chosen for oral dosing in dogs. The reasonable correlation found between the FTC dissolution results and the oral bioavailability data demonstrate that FTC dissolution testing can be a valuable tool for aiding in salt (solid-state form) and formulation selection in the early stages of development of drug candidates.

Solvent screening for a hard-to-dissolve molecular crystal.

PubMed

Maiti, A; Pagoria, P F; Gash, A E; Han, T Y; Orme, C A; Gee, R H; Fried, L E

2008-09-01

Materials with a high-degree of inter- and intra-molecular hydrogen bonding generally have limited solubility in conventional organic solvents. This presents a problem for the dissolution, manipulation and purification of these materials. Using a state-of-the-art density-functional-theory based quantum chemical solvation model we systematically evaluated solvents for a known hydrogen-bonded molecular crystal. This, coupled with direct solubility measurements, uncovered a class of ionic liquids involving fluoride anions that possess more than two orders of magnitude higher solvation power as compared with the best conventional solvents. The crystal structure of one such ionic liquid, determined by X-ray diffraction spectroscopy, indicates that F- ions are stabilized through H-bonded chains with water. The presence of coordinating water in such ionic liquids seems to facilitate the dissolution process by keeping the chemical activity of the F- ions in check.

Andrographolide: solving chemical instability and poor solubility by means of cocrystals.

PubMed

Suresh, Kuthuru; Goud, N Rajesh; Nangia, Ashwini

2013-12-01

The bioactive agent andrographolide was screened with pharmaceutically acceptable coformers to discover a novel solid form that will solve the chemical instability and poor solubility problems of this herbal medicine. Liquid-assisted grinding of andrographolide with GRAS (generally regarded as safe) coformers in a fixed stoichiometry resulted in cocrystals with vanillin (1:1), vanillic acid (1:1), salicylic acid (1:1), resorcinol (1:1), and guaiacol (1:1). All the crystalline products were characterized by thermal, spectroscopic, and diffraction methods. Interestingly, even though the cocrystals are isostructural, their physicochemical properties are quite different. The andrographolide-salicylic acid cocrystal completely inhibited the chemical transformation of andrographolide to its inactive sulfate metabolite, and moreover, the cocrystal exhibited a dissolution rate that was three times faster and a drug release that was two times higher than pure andrographolide. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DNA binding and biological studies of some novel water-soluble polymer-copper(II)-phenanthroline complexes.

PubMed

Kumar, Rajendran Senthil; Arunachalam, Sankaralingam; Periasamy, Vaiyapuri Subbarayan; Preethy, Christo Paul; Riyasdeen, Anvarbatcha; Akbarsha, Mohammad Abdulkader

2008-10-01

Some novel water-soluble polymer-copper(II)-phenanthroline complex samples, [Cu(phen)2(BPEI)]Cl(2).4H2O (phen=1,10-phenanthroline, BPEI=branched polyethyleneimine), with different degrees of copper complex content in the polymer chain have been prepared by ligand substitution method in water-ethanol medium and characterized by infrared, UV-visible, EPR spectral and elemental analysis methods. The binding of these complex samples with DNA has been investigated by electronic absorption spectroscopy, emission spectroscopy and gel retardation assay. Electrostatic interactions between DNA molecule and polymer-copper(II) complex molecule containing many high positive charges have been observed. Besides these ionic interactions, van der Waals interactions, hydrogen bonding and other partial intercalation binding modes may also exist in this system. The polymer-copper(II) complex with higher degree of copper complex content was screened for its antimicrobial activity and antitumor activity.

Human epidermis is a novel site of phospholipase B expression.

PubMed

Maury, Eric; Prévost, Marie Claude; Nauze, Michel; Redoulès, Daniel; Tarroux, Roger; Charvéron, Marie; Salles, Jean Pierre; Perret, Bertrand; Chap, Hugues; Gassama-Diagne, Ama

2002-07-12

Phospholipase B (PLB) is an enzyme that displays both phospholipase A(2) and lysophospholipase activities. Analysis of human epidermis homogenates indicated the presence of a 97 kDa PLB protein, as well as a phospholipase A(2) activity, both being enriched in the soluble fraction. Immunolabelling and in situ hybridization experiments showed that this enzyme is expressed in the different layers of epidermis with an accumulation at the dermo-epidermis junction. RT-PCR data indicated that PLB is specifically expressed in natural and reconstructed epidermis. By 3'-RACE-PCR and screening of human genome databases, we obtained a 3600 bp cDNA coding for human PLB highly homologous to already described intestinal brush border PLBs. These data led us to conclude that the soluble PLB corresponds to a proteolytic cleavage of the membrane anchored protein. Altogether, our results provide the first characterization of human PLB which should play an important role in epidermal barrier function.

Isolating and Testing Circulating Tumor DNA and Soluble Immune Markers During the Course of Treatment for Lung Cancer

ClinicalTrials.gov

2018-01-08

Lung Cancer; Lung Neoplasms; Cancer of Lung; Cancer of the Lung; Neoplasms, Lung; Neoplasms, Pulmonary; Pulmonary Cancer; Pulmonary Neoplasms; Carcinoma, Non-small-cell Lung; Adenocarcinoma; Squamous Cell Carcinoma

Nonlinear Transport in Organic Thin Film Transistors with Soluble Small Molecule Semiconductor.

PubMed

Kim, Hyeok; Song, Dong-Seok; Kwon, Jin-Hyuk; Jung, Ji-Hoon; Kim, Do-Kyung; Kim, SeonMin; Kang, In Man; Park, Jonghoo; Tae, Heung-Sik; Battaglini, Nicolas; Lang, Philippe; Horowitz, Gilles; Bae, Jin-Hyuk

2016-03-01

Nonlinear transport is intensively explained through Poole-Frenkel (PF) transport mechanism in organic thin film transistors with solution-processed small molecules, which is, 6,13-bis(triisopropylsilylethynyl) (TIPS) pentacene. We outline a detailed electrical study that identifies the source to drain field dependent mobility. Devices with diverse channel lengths enable the extensive exhibition of field dependent mobility due to thermal activation of carriers among traps.

Ambipolar Small-Molecule:Polymer Blend Semiconductors for Solution-Processable Organic Field-Effect Transistors.

PubMed

Kang, Minji; Hwang, Hansu; Park, Won-Tae; Khim, Dongyoon; Yeo, Jun-Seok; Kim, Yunseul; Kim, Yeon-Ju; Noh, Yong-Young; Kim, Dong-Yu

2017-01-25

We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

Steady-state structural fluctuation is a predictor of the necessity of pausing-mediated co-translational folding for small proteins.

PubMed

Huang, Wenxi; Liu, Wanting; Jin, Jingjie; Xiao, Qilan; Lu, Ruibin; Chen, Wei; Xiong, Sheng; Zhang, Gong

2018-03-25

Translational pausing coordinates protein synthesis and co-translational folding. It is a common factor that facilitates the correct folding of large, multi-domain proteins. For small proteins, pausing sites rarely occurs in the gene body, and the 3'-end pausing sites are only essential for the folding of a fraction of proteins. The determinant of the necessity of the pausings remains obscure. In this study, we demonstrated that the steady-state structural fluctuation is a predictor of the necessity of pausing-mediated co-translational folding for small proteins. Validated by experiments with 5 model proteins, we found that the rigid protein structures do not, while the flexible structures do need 3'-end pausings to fold correctly. Therefore, rational optimization of translational pausing can improve soluble expression of small proteins with flexible structures, but not the rigid ones. The rigidity of the structure can be quantitatively estimated in silico using molecular dynamic simulation. Nevertheless, we also found that the translational pausing optimization increases the fitness of the expression host, and thus benefits the recombinant protein production, independent from the soluble expression. These results shed light on the structural basis of the translational pausing and provided a practical tool for industrial protein fermentation. Copyright © 2017. Published by Elsevier Inc.

Optimization and design of ibuprofen-loaded nanostructured lipid carriers using a hybrid-design approach for ocular drug delivery

NASA Astrophysics Data System (ADS)

Rathod, Vishal

The objective of the present project was to develop the Ibuprofen-loaded Nanostructured Lipid Carrier (IBU-NLCs) for topical ocular delivery based on substantial pre-formulation screening of the components and understanding the interplay between the formulation and process variables. The BCS Class II drug: Ibuprofen was selected as the model drug for the current study. IBU-NLCs were prepared by melt emulsification and ultrasonication technique. Extensive pre-formulation studies were performed to screen the lipid components (solid and liquid) based on drug's solubility and affinity as well as components compatibility. The results from DSC & XRD assisted in selecting the most suitable ratio to be utilized for future studies. DynasanRTM 114 was selected as the solid lipid & MiglyolRTM 840 was selected as the liquid lipid based on preliminary lipid screening. The ratio of 6:4 was predicted to be the best based on its crystallinity index and the thermal events. As there are many variables involved for further optimization of the formulation, a single design approach is not always adequate. A hybrid-design approach was applied by employing the Plackett Burman design (PBD) for preliminary screening of 7 critical variables, followed by Box-Behnken design (BBD), a sub-type of response surface methodology (RSM) design using 2 relatively significant variables from the former design and incorporating Surfactant/Co-surfactant ratio as the third variable. Comparatively, KolliphorRTM HS15 demonstrated lower Mean Particle Size (PS) & Polydispersity Index (PDI) and KolliphorRTM P188 resulted in Zeta Potential (ZP) < -20 mV during the surfactant screening & stability studies. Hence, Surfactant/Cosurfactant ratio was employed as the third variable to understand its synergistic effect on the response variables. We selected PS, PDI, and ZP as critical response variables in the PBD since they significantly influence the stability & performance of NLCs. Formulations prepared using BBD were further characterized and evaluated concerning PS, PDI, ZP and Entrapment Efficiency (EE) to identify the multi-factor interactions between selected formulation variables. In vitro release studies were performed using Spectra/por dialysis membrane on Franz diffusion cell and Phosphate Saline buffer (7.4 pH) as the medium. Samples for assay, EE, Loading Capacity (LC), Solubility studies & in-vitro release were filtered using Amicon 50K and analyzed via UPLC system (Waters) at a detection wavelength of 220 nm. Significant variables were selected through PBD, and the third variable was incorporated based on surfactant screening & stability studies for the next design. Assay of the BBD based formulations was found to be within 95-104% of the theoretically calculated values. Further studies were investigated for PS, PDI, ZP & EE. PS was found to be in the range of 103-194 nm with PDI ranging from 0.118 to 0.265. The ZP and EE were observed to be in the range of -22.2 to -11 mV & 90 to 98.7 % respectively. Drug release of 30% was observed from the optimized formulation in the first 6 hr of in-vitro studies, and the drug release showed a sustained release of ibuprofen thereafter over several hours. These values also confirm that the production method, and all other selected variables, effectively promoted the incorporation of ibuprofen in NLC. Quality by Design (QbD) approach was successfully implemented in developing a robust ophthalmic formulation with superior physicochemical and morphometric properties. NLCs as the nanocarrier demonstrated promising perspective for topical delivery of poorly water-soluble drugs.

Fragment-based screening in tandem with phenotypic screening provides novel antiparasitic hits.

PubMed

Blaazer, Antoni R; Orrling, Kristina M; Shanmugham, Anitha; Jansen, Chimed; Maes, Louis; Edink, Ewald; Sterk, Geert Jan; Siderius, Marco; England, Paul; Bailey, David; de Esch, Iwan J P; Leurs, Rob

2015-01-01

Methods to discover biologically active small molecules include target-based and phenotypic screening approaches. One of the main difficulties in drug discovery is elucidating and exploiting the relationship between drug activity at the protein target and disease modification, a phenotypic endpoint. Fragment-based drug discovery is a target-based approach that typically involves the screening of a relatively small number of fragment-like (molecular weight <300) molecules that efficiently cover chemical space. Here, we report a fragment screening on TbrPDEB1, an essential cyclic nucleotide phosphodiesterase (PDE) from Trypanosoma brucei, and human PDE4D, an off-target, in a workflow in which fragment hits and a series of close analogs are subsequently screened for antiparasitic activity in a phenotypic panel. The phenotypic panel contained T. brucei, Trypanosoma cruzi, Leishmania infantum, and Plasmodium falciparum, the causative agents of human African trypanosomiasis (sleeping sickness), Chagas disease, leishmaniasis, and malaria, respectively, as well as MRC-5 human lung cells. This hybrid screening workflow has resulted in the discovery of various benzhydryl ethers with antiprotozoal activity and low toxicity, representing interesting starting points for further antiparasitic optimization. © 2014 Society for Laboratory Automation and Screening.

Effects of small-scale vertical variations in well-screen inflow rates and concentrations of organic compounds on the collection of representative ground-water-quality samples

USGS Publications Warehouse

Gibs, Jacob; Brown, G. Allan; Turner, Kenneth S.; MacLeod, Cecilia L.; Jelinski, James; Koehnlein, Susan A.

1993-01-01

Because a water sample collected from a well is an integration of water from different depths along the well screen, measured concentrations can be biased if analyte concentrations are not uniform along the length of the well screen. The resulting concentration in the sample, therefore, is a function of variations in well-screen inflow rate and analyte concentration with depth. A multiport sampler with seven short screened intervals was designed and used to investigate small-scale vertical variations in water chemistry and aquifer hydraulic conductivity in ground water contaminated by leaded gasoline at Galloway Township, Atlantic County, New Jersey. The multiport samplers were used to collect independent samples from seven intervals within the screened zone that were flow-rate weighted and integrated to simulate a 5-foot-long, 2.375-inch- outside-diameter conventional wire-wound screen. The integration of the results of analyses of samples collected from two multiport samplers showed that a conventional 5-foot-long well screen would integrate contaminant concentrations over its length and resulted in an apparent contaminant concentration that was a little as 28 percent of the maximum concentration observed in the multiport sampler.

Poly(aspartic acid) with adjustable pH-dependent solubility.

PubMed

Németh, Csaba; Gyarmati, Benjámin; Abdullin, Timur; László, Krisztina; Szilágyi, András

2017-02-01

Poly(aspartic acid) (PASP) derivatives with adjustable pH-dependent solubility were synthesized and characterized to establish the relationship between their structure and solubility in order to predict their applicability as a basic material for enteric coatings. Polysuccinimide, the precursor of PASP, was modified with short chain alkylamines, and the residual succinimide rings were subsequently opened to prepare the corresponding PASP derivatives. Study of the effect of the type and concentration of the side groups on the pH-dependent solubility of PASP showed that solubility can be adjusted by proper selection of the chemical structure. The Henderson-Hasselbalch (HH) and the extended HH equations were used to describe the pH-dependent solubility of the polymers quantitatively. The estimate provided by the HH equation is poor, but an accurate description of the pH-dependent solubility can be found with the extended HH equation. The dissolution rate of a polymer film prepared from a selected PASP derivative was determined by fluorescence marking. The film dissolved rapidly when the pH was increased above its pK a . Cellular viability tests show that PASP derivatives are non-toxic to a human cell line. These polymers are thus of great interest as starting materials for enteric coatings. Poly(amino acid) type biocompatible polymers were synthesized for future use as pharmaceutical film coatings. To this end, we tailored the pH-dependent solubility of poly(aspartic acid) (PASP). It was found that both the solubility and the pK a values of the modified PASP depended strongly on composition. Fluorescent marking was used to characterize the dissolution of a chosen PASP derivative. In acidic media only a negligible amount of the polymer dissolved, but dissolution was very fast and complete at the pH values that prevail in the small intestine. As a consequence, enteric coatings based on such PASP derivatives may be used for drug delivery in the gastrointestinal tract. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A New Method of Constructing a Drug-Polymer Temperature-Composition Phase Diagram Using Hot-Melt Extrusion.

PubMed

Tian, Yiwei; Jones, David S; Donnelly, Conor; Brannigan, Timothy; Li, Shu; Andrews, Gavin P

2018-04-02

Current experimental methodologies used to determine the thermodynamic solubility of an API within a polymer typically involves establishing the dissolution/melting end point of the crystalline API within a physical mixture or through the use of the glass transition temperature measurement of a demixed amorphous solid dispersion. The measurable "equilibrium" points for solubility are normally well above the glass transition temperature of the system, meaning extrapolation is required to predict the drug solubility at pharmaceutically relevant temperatures. In this manuscript, we argue that the presence of highly viscous polymers in these systems results in experimental data that exhibits an under or overestimated value relative to the true thermodynamic solubility. In previous work, we demonstrated the effects of experimental conditions and their impact on measured and predicted thermodynamic solubility points. In light of current understanding, we have developed a new method to limit error associated with viscosity effects for application in small-scale hot-melt extrusion (HME). In this study, HME was used to generate an intermediate (multiphase) system containing crystalline drug, amorphous drug/polymer-rich regions as well as drug that was molecularly dispersed in polymer. An extended annealing method was used together with high-speed differential scanning calorimetry to accurately determine the upper and lower boundaries of the thermodynamic solubility of a model drug-polymer system (felodipine and Soluplus). Compared to our previously published data, the current results confirmed our hypothesis that the prediction of the liquid-solid curve using dynamic determination of dissolution/melting end point of the crystalline API physical mixture presents an underestimation relative to the thermodynamic solubility point. With this proposed method, we were able to experimentally measure the upper and lower boundaries of the liquid-solid curve for the model system. The relationship between inverse temperature and drug-polymer solubility parameter (χ) remained linear at lower drug loadings. Significantly higher solubility and miscibility between the felodipine-Soluplus system were derived from the new χ values.

Phytochemical screening and in-vitro antioxidant activity isolated bioactive compounds from Tridax procumbens Linn.

PubMed

Saxena, Manjusha; Mir, Abrar Hussain; Sharma, Manik; Malla, Mohd Yousu; Qureshi, Sumeerah; Mir, Mohd Iqbal; Chaturvedi, Yogesh

2013-12-15

Tridax procumbens L., Asteraceae, has been extensively used for various ailments in the Ayurvedic system of medicine. Previous studies have revealed remarkable phytoconstituents from Tridax procumbens L. with significant antioxidant activity. The aim of the present study is to measure the anti-DPPH activity of the purified isolated compounds from n butanol soluble part and ethyl acetate soluble part of successive methanolic extract of Tridax procumbens L. We thus quantified the total phenolic and total flavonoids in different purified isolated compounds, the whole of the tests were evaluated with a sample cone. of 100 microg mL(-1) and were determined spectrophotometrically using Folin-ciocaltue and AlCl3 reagents, respectively. DPPH (1,1-diphenyl, 2-picryl hydrazyl) assay was used to determine the in vitro antioxidant activity of different isolated compounds. Isolated compounds, one from ethyl acetate soluble part (EF-I) and one from n butanol soluble part (BF-II) were reported to possess a significant anti DPPH activity with lowest IC50 values 67.26 and 80.90 microg mL(-1), respectively while comparable to standard ascorbic acid with IC50 value of 59.62 microg mL(-1), due to the high concentration of phenols 146.4 microg mL(-1) from EF-I and 142.2 microg mL(-1) from BF-II and flavonoids 48 and 42.5 microg mL(-1) found in EF-I and BF-II isolated compounds, respectively.

Influence of carboxyl anion on the dissolution of chitosan in cholinium-based ionic liquids

NASA Astrophysics Data System (ADS)

Liu, Dong; Chen, Qingtai; Li, Min; Lou, Bin; Yu, Ran; Li, Zhiheng; Zhang, Yadong

2018-06-01

Chitosan can be applied in because of its excellent antimicrobial activity and abundant bio renewable and biodegradable resource. To better utilize this kind of native polysaccharide, it is still necessary to develop an efficient chitosan solvent system. Tn present study, 6 kinds of novel choline carboxylate ionic liquids (ILs) were developed. The solubility of chitosan in these H2O-ILs with different molar ratio were measured at 25 °C. The effect of the carboxylate anion of the ILs on chitosan solubility was estimated and found that the solubility of chitosan in the H2O-IL increased with the increasing of alkyl chain length in the anion. Moreover, the H2O-IL solution would not able to dissolve chitosan because the proton H was alternated by employing NH2 or OH group. The H2O-[Ch][CH3CH2CH2COO] (Rmol=6:1) solvent system exhibits highly efficient capacity for the dissolution of chitosan, and the solubility of chitosan reached up to 20.8 wt.%. From NMR measurement, these results could be explained by the possible interaction between carboxylate anion and chitosan and the strong hydration of the carboxyl group in the IL, suggesting that anionic structure have a significant impact on the dissolution of chitosan in the H2O-IL solvent system. Altogether, these results would provide an important evaluation indicator for screening the most suitable solvent system of chitosan.

Mixed Micelle System Produced by Interaction Between Transglycosylated Stevia and an Ionic Surfactant Improves Dissolution Profile of Mefenamic Acid.

PubMed

Fujimori, Miki; Kadota, Kazunori; Tozuka, Yuichi

2017-04-01

Transglycosylated stevia (stevia-G) can effectively improve the dissolution and bioavailability of poorly water-soluble drugs. Furthermore, addition of an ionic surfactant to stevia-G solution has been shown to enhance the dissolution effect of stevia-G on flurbiprofen. Herein, 4 surfactants, namely sodium dodecyl sulfate, sodium N-dodecanoylsarcosinate, sodium monododecyl phosphate, and lauryltrimethylammonium chloride (LTAC) were screened to investigate their synergistic effect with stevia-G in enhancing the solubility of mefenamic acid (MFA). The ternary formulation containing LTAC produced the highest increase in solubility, whereas the binary MFA/LTAC formulation did not increase the solubility of MFA. Surface tension was evaluated to analyze the interaction between stevia-G and each ionic surfactant, wherein the Rubingh model was applied to predict mixed micelle formation between stevia-G and LTAC. Interaction parameters calculated by the Rubingh model reflected mixed micelle formation between stevia-G and LTAC relative to the self-interactions of the 2 individual surfactants. All interaction parameters in this system showed negative values, indicating a favorable interaction (e.g., hydrogen bond or electrostatic and dipole) between binary components in the mixed micelles. Spray-dried particles of ternary formulations (MFA/stevia-G/LTAC) were prepared to evaluate the dissolution profile and physicochemical properties. Dissolution profiling showed that the concentration of MFA released from spray-dried particles was significantly higher than untreated MFA. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Pharmacognostical and Phytochemical Studies of Helleborus niger L Root.

PubMed

Kumar, V Kishor; Lalitha, K G

2017-01-01

Helleborus niger L (Ranunculaceae) is used Ayurvedic and Unani systems and other herbal medicine systems. The roots of H. niger have a good medicinal value. To conduct a pharmacognostical and phytochemical study of H. niger . The pharmacognostical studies on roots including parameters such as taxonomical, macroscopic, microscopic characters, physico-chemical, ultra-violet analysis and phytochemical studies are established. Macroscopically, the roots are brownish-black in colour, cylindrical in shape, feeble odour, slightly acrid taste with irregularly branched. Microscopically the root showed the presence of epidermis, air-chambers, fissure periderm, periderm, inner cortex, pith, phloem, xylem, vessels and xylem vessels. Microscopic examination of the powder showed the presence of parenchyma cells, parenchyma mass, periderm, cell inclusion, laticifer, lateral wall pith, perforation, xylem bundle and xylem elements. Ultra-violet and ordinary light analyses with different reagents were conducted to identify the drug in powder form. Physico-chemical evaluation established, Ash values - Total, acid insoluble, water soluble and sulphated ash values were 7.3%, 4.1%, 3.7% and 5.2%, respectively. Extractive values - Alcohol soluble, water soluble and ether soluble extractive values were 22.8%, 7.4% and 5.6%, respectively. Loss on drying was 3.3%. Preliminary phytochemical screening showed the presence of carbohydrate, glycoside, saponins, flavonoid, phytosterols, tannins and phenolic compounds. The results of the study can serve as a valuable resource of pharmacognostic and phytochemical information. This will serve as appropriate, standards for discovery of this plant material in future investigations and applications and also contribute towards establishing pharmacopoeial standards.

A comparative study on Ca content and distribution in two Gesneriaceae species reveals distinctive mechanisms to cope with high rhizospheric soluble calcium

PubMed Central

Li, Wenlong; Xu, Falun; Chen, Shixuan; Zhang, Zhennan; Zhao, Yan; Jin, Yukuan; Li, Meijing; Zhu, Yan; Liu, Yongxiu; Yang, Yi; Deng, Xin

2014-01-01

Excessive Ca is toxic to plants thus significantly affects plant growth and species distribution in Ca-rich karst areas. To understand how plants survive high Ca soil, laboratory experiments were established to compare the physiological responses and internal Ca distribution in organ, tissue, cell, and intracellular levels under different Ca levels for Lysionotus pauciflorus and Boea hygrometrica, two karst habitant Gesneriaceae species in Southwest China. In the controlled condition, L. pauciflorus could survive as high as 200 mM rhizospheric soluble Ca, attributed to a series of physiological responses and preferential storage that limited Ca accumulation in chloroplasts of palisade cells. In contrast, B. hygrometrica could survive only 20 mM rhizospheric soluble Ca, but accumulated a high level of internal Ca in both palisade and spongy cells without disturbance on photosynthetic activity. By phenotype screening of transgenic plants expressing high Ca-inducible genes from B. hygrometrica, the expression of BhDNAJC2 in A. thaliana was found to enhance plant growth and photosynthesis under high soluble Ca stress. BhDNAJC2 encodes a recently reported heat shock protein (HSP) 40 family DnaJ-domain protein. The Ca-resistant phenotype of BhDNAJC2 highlights the important role of chaperone-mediated protein quality control in Ca tolerance in B. hygrometrica. Taken together, our results revealed that distinctive mechanisms were employed in the two Gesneriaceae karst habitants to cope with a high Ca environment. PMID:25477893

Treatment Options by Stage (Small Cell Lung Cancer)

MedlinePlus

... Lung Cancer Prevention Lung Cancer Screening Research Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Small Cell Lung Cancer Go to Health Professional Version Key ...

Stages of Non-Small Cell Lung Cancer

MedlinePlus

... Cancer Prevention Lung Cancer Screening Research Non-Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Non-Small Cell Lung Cancer Go to Health Professional Version Key ...

A water-soluble extract from cultured medium of Ganoderma lucidum (Reishi) mycelia attenuates the small intestinal injury induced by anti-cancer drugs

PubMed Central

KASHIMOTO, NAOKI; ISHII, SATOMI; MYOJIN, YUKI; USHIJIMA, MITSUYASU; HAYAMA, MINORU; WATANABE, HIROMITSU

2010-01-01

The present study investigated whether a water-soluble extract from the culture medium of Ganoderma lucidum (Reishi) mycelia (MAK) is able to protect the small intestine against damage induced by anti-cancer drugs. Six-week-old male B6C3F1/Crlj mice were fed a basal diet (MF) alone or with various doses of MAK or Agarics blazei Murrill (AGA) beginning one week before treatment with the anti-cancer drugs. Mice were sacrificed 3.5 days after injection of the anti-cancer drug, the small intestine was removed and tissue specimens were examined for the regeneration of small intestinal crypts. In experiment 1, the number of regenerative crypts after the administration of 5-fluorouracil (5FU) intravenously (250 mg/kg) or intraperitoneally (250 or 500 mg/kg) was compared after treatment with MAK or AGA. MAK protected against 5FU-induced small intestinal injury whereas AGA did not. In experiment 2, we investigated the protective effect of MAK against small intestinal injury induced by the anti-cancer drugs: UFT (tegafur with uracil; 1,000 mg/kg, orally), cisplatin (CDDP; 12.5 and 25 mg/kg, intraperitoneally), cyclophosphamide (CPA; 250 mg/kg, orally) and gefitinib (Iressa; 2,000 and 4,000 mg/kg, orally). UFT and CDDP decreased the number of regenerative crypts, but treatment with MAK attenuated the extent of UFT- or CDDP-induced small intestinal injury. CPA or Iressa plus MAK up-regulated crypt regeneration. The present results indicate that MAK ameliorates the small intestinal injury caused by several anti-cancer drugs, suggesting that MAK is a potential preventive agent against this common adverse effect of chemotherapy. PMID:22966257

The neutral oil in commercial linear alkylbenzenesulfonate and its effect on organic solute solubility in water

USGS Publications Warehouse

Chiou, C.T.; Kile, D.E.; Rutherford, D.W.

1991-01-01

Apparent water solubilities of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 2,4,5,2???,5???-penta-chlorobiphenyl (PCB), and 1,2,3-trichlorobenzene (TCB) were determined at room temperature in aqueous solutions of commercial linear alkylbenzenesulfonate (LAS), oil-free (solvent-extracted) LAS, and single-molecular 4-dodecyl-benzenesulfonate. The extent of solute solubility enhancement by commercial LAS is markedly greater than that by other ionic surfactants below the measured critical micelle concentration (CMC); above the CMC, the enhancement data with LAS are comparable with other surfactants as micelles. The small amount of neutral oils in commercial LAS (1.7%), comprising linear alkylbenzenes (LABs) and bis(alkylphenyl) sulfones, contributes significantly to the enhanced solubility of DDT and PCB below the CMC; the effect is ascribed to formation of oil-surfactant emulsions. The oil-surfactant emulsion formed corresponds to ???9-10% of the commercial LAS below the CMC. The data suggest that discharge of wastewater containing a significant level of oils and surface-active agents could lead to potential mobilization of organic pollutants and LABs in aquatic environments.

Determination of the solubility of inorganic salts by headspace gas chromatography.

PubMed

Chai, X S; Zhu, J Y

2003-05-09

This work reports a novel method for determination of salt solubility using headspace gas chromatography. A very small amount of volatile compound (such as methanol) is added in the studied solution. Due to the molecular interaction in the solution, the vapor-liquid equilibrium (VLE) partitioning coefficient of the volatile species will change with different salt contents in the solution. Therefore, the concentration of volatile species in the vapor phase is proportional to the salt concentration in the liquid phase, which can be easily determined by headspace gas chromatography. Until the salt concentration in the solution is saturated, the concentration of volatile compound in the vapor phase will continue to increase further and a breakpoint will appear on the VLE curve. The solubility of the salts can be determined by the identification of the breakpoint. It was found that the measured solubility of sodium carbonate and sodium sulfate in aqueous solutions is slightly higher (about 6-7%) than those reported in the literature method. The present method can be easily applied to industrial solution systems.

Wax encapsulation of water-soluble compounds for application in foods.

PubMed

Mellema, M; Van Benthum, W A J; Boer, B; Von Harras, J; Visser, A

2006-11-01

Water-soluble ingredients have been successfully encapsulated in wax using two preparation techniques. The first technique ('solid preparation') leads to relatively large wax particles. The second technique ('liquid preparation') leads to relatively small wax particles immersed in vegetable oil. On the first technique: stable encapsulation of water-soluble colourants (dissolved at low concentration in water) has been achieved making use of beeswax and PGPR. The leakage from the capsules, for instance of size 2 mm, is about 30% after 16 weeks storage in water at room temperature. To form such capsules a minimum wax mass of 40% relative to the total mass is needed. High amounts of salt or acids at the inside water phase causes more leaking, probably because of the osmotic pressure difference. Osmotic matching of inner and outer phase can lead to a dramatic reduction in leakage. Fat capsules are less suitable to incorporate water soluble colourants. The reason for this could be a difference in crystal structure (fat is less ductile and more brittle). On the second technique: stable encapsulation of water-soluble colourants (encapsulated in solid wax particles) has been achieved making use of carnauba wax. The leakage from the capsules, for instance of size 250 mm, is about 40% after 1 weeks storage in water at room temperature.

Uptake and Dissolution of Gaseous Ethanol in Sulfuric Acid

NASA Technical Reports Server (NTRS)

Michelsen, Rebecca R.; Staton, Sarah J. R.; Iraci, Laura T.

2006-01-01

The solubility of gas-phase ethanol (ethyl alcohol, CH3CH2OH, EtOH) in aqueous sulfuric acid solutions was measured in a Knudsen cell reactor over ranges of temperature (209-237 K) and acid composition (39-76 wt % H2SO4). Ethanol is very soluble under these conditions: effective Henry's law coefficients, H*, range from 4 x 10(exp 4) M/atm in the 227 K, 39 wt % acid to greater than 10(exp 7) M/atm in the 76 wt % acid. In 76 wt % sulfuric acid, ethanol solubility exceeds that which can be precisely determined using the Knudsen cell technique but falls in the range of 10(exp 7)-10(exp 10) M/atm. The equilibrium concentration of ethanol in upper tropospheric/lower stratospheric (UT/LS) sulfate particles is calculated from these measurements and compared to other small oxygenated organic compounds. Even if ethanol is a minor component in the gas phase, it may be a major constituent of the organic fraction in the particle phase. No evidence for the formation of ethyl hydrogen sulfate was found under our experimental conditions. While the protonation of ethanol does augment solubility at higher acidity, the primary reason H* increases with acidity is an increase in the solubility of molecular (i.e., neutral) ethanol.

Improving solubility and refolding efficiency of human V(H)s by a novel mutational approach.

PubMed

Tanha, Jamshid; Nguyen, Thanh-Dung; Ng, Andy; Ryan, Shannon; Ni, Feng; Mackenzie, Roger

2006-11-01

The antibody V(H) domains of camelids tend to be soluble and to resist aggregation, in contrast to human V(H) domains. For immunotherapy, attempts have therefore been made to improve the properties of human V(H)s by camelization of a small set of framework residues. Here, we have identified through sequence comparison of well-folded llama V(H) domains an alternative set of residues (not typically camelid) for mutation. Thus, the solubility and thermal refolding efficiency of a typical human V(H), derived from the human antibody BT32/A6, were improved by introduction of two mutations in framework region (FR) 1 and 4 to generate BT32/A6.L1. Three more mutations in FR3 of BT32/A6.L1 further improved the thermal refolding efficiency while retaining solubility and cooperative melting profiles. To demonstrate practical utility, BT32/A6.L1 was used to construct a phage display library from which were isolated human V(H)s with good antigen binding activity and solubility. The engineered human V(H) domains described here may be useful for immunotherapy, due to their expected low immunogenicity, and in applications involving transient high temperatures, due to their efficient refolding after thermal denaturation.

The Curious Case of the OZ439 Mesylate Salt: An Amphiphilic Antimalarial Drug with Diverse Solution and Solid State Structures.

PubMed

Clulow, Andrew J; Salim, Malinda; Hawley, Adrian; Gilbert, Elliot P; Boyd, Ben J

2018-05-07

Efforts to develop orally administered drugs tend to place an exceptional focus on aqueous solubility as this is an essential criterion for their absorption in the gastrointestinal tract. In this work we examine the solid state behavior and solubility of OZ439, a promising single-dose cure for malaria being developed as the highly water-soluble mesylate salt. The aqueous phase behavior of the OZ439 mesylate salt was determined using a combination of small angle neutron and X-ray scattering (SANS and SAXS, respectively). It was found that this salt has low solubility at low concentrations with the drug largely precipitated in free base aggregates. However, with increasing concentration these crystalline aggregates were observed to dissociate into cationic micelles and lamellar phases, effectively increasing the dissolved drug concentration. It was also found that the dissolved OZ439 spontaneously precipitated in the presence of biologically relevant anions, which we attribute to the high lattice energies of most of the salt forms of the drug. These findings show that aqueous solubility is not always what it seems in the context of amphiphilic drug molecules and highlights that its use as the principal metric in selecting drug candidates for development can be perilous.

Production of a water-soluble fertilizer containing amino acids by solid-state fermentation of soybean meal and evaluation of its efficacy on the rapeseed growth.

PubMed

Wang, Jianlei; Liu, Zhemin; Wang, Yue; Cheng, Wen; Mou, Haijin

2014-10-10

Soybean meal is a by-product of soybean oil extraction and contains approximately 44% protein. We performed solid-state fermentation by using Bacillus subtilis strain N-2 to produce a water-soluble fertilizer containing amino acids. Strain N-2 produced a high yield of protease, which transformed the proteins in soybean meal into peptide and free amino acids that were dissolved in the fermentation products. Based on the Plackett-Burman design, the initial pH of the fermentation substrate, number of days of fermentation, and the ratio of liquid to soybean meal exhibited significant effects on the recovery of proteins in the resulting water-soluble solution. According to the predicted results of the central composite design, the highest recovery of soluble proteins (99.072%) was achieved at the optimum conditions. Under these conditions, the resulting solution contained 50.42% small peptides and 7.9% poly-γ-glutamic acid (γ-PGA). The water-soluble fertilizer robustly increased the activity of the rapeseed root system, chlorophyll content, leaf area, shoot dry weight, root length, and root weight at a concentration of 0.25% (w/v). This methodology offers a value-added use of soybean meal. Copyright © 2014 Elsevier B.V. All rights reserved.

Pyrene-Labeled Amphiphiles: Dynamic And Structural Probes Of Membranes And Lipoproteins

NASA Astrophysics Data System (ADS)

Pownall, Henry J.; Homan, Reynold; Massey, John B.

1987-01-01

Lipids and proteins are important functional and structural components of living organisms. Although proteins are frequently found as soluble components of plasma or the cell cytoplasm, many lipids are much less soluble and separate into complex assemblies that usually contain proteins. Cell membranes and plasma lipoproteins' are two important macro-molecular assemblies that contain both lipids and proteins. Cell membranes are composed of a variety of lipids and proteins that form an insoluble bilayer array that has relatively little curvature over distances of several nm. Plasma lipoproteins are different in that they are much smaller, water-soluble, and have highly curved surfaces. A model of a high density lipoprotein (HDL) is shown in Figure 1. This model (d - 10 nm) contains a surface of polar lipids and proteins that surrounds a small core of insoluble lipids, mostly triglycerides and cholesteryl esters. The low density (LDL) (d - 25 nm) and very low density (VLDL) (d 90 nm) lipoproteins have similar architectures, except the former has a cholesteryl ester core and the latter a core that is almost exclusively triglyceride (Figure 1). The surface proteins of HDL are amphiphilic and water soluble; the single protein of LDL is insoluble, whereas VLDL contains both soluble and insoluble proteins. The primary structures of all of these proteins are known.

Proof of Principle: Immobilisation of Robust CuII3 TbIII -Macrocycles on Small, Suitably Pre-functionalised Gold Nanoparticles.

PubMed

Feltham, Humphrey L C; Dumas, Christophe; Mannini, Matteo; Otero, Edwige; Sainctavit, Philippe; Sessoli, Roberta; Meledandri, Carla J; Brooker, Sally

2017-02-21

In a proof-of-principle study, a soluble macrocyclic single-molecule magnet (SMM) containing a Cu II 3 Tb III magnetic core was covalently grafted onto small gold nanoparticles pre-functionalised with carboxylate-terminated tethers. A modified microemulsion method allowed production of the small and monodisperse nanoparticles (approximately 3.5 nm in diameter) for the chemisorption of a large amount of intact macrocyclic complexes in the hybrid system. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultraviolet radiation and the snow alga Chlamydomonas nivalis (Bauer) Wille.

PubMed

Gorton, Holly L; Vogelmann, Thomas C

2003-06-01

Aplanospores of Chlamydomonas nivalis are frequently found in high-altitude, persistent snowfields where they are photosynthetically active despite cold temperatures and high levels of visible and ultraviolet (UV) radiation. The goals of this work were to characterize the UV environment of the cells in the snow and to investigate the existence and localization of screening compounds that might prevent UV damage. UV irradiance decreased precipitously in snow, with UV radiation of wavelengths 280-315 nm and UV radiation of wavelengths 315-400 nm dropping to 50% of incident levels in the top 1 and 2 cm, respectively. Isolated cell walls exhibited UV absorbance, possibly by sporopollenin, but this absorbance was weak in images of broken or plasmolyzed cells observed through a UV microscope. The cells also contained UV-absorbing cytoplasmic compounds, with the extrachloroplastic carotenoid astaxanthin providing most of the screening. Additional screening compound(s) soluble in aqueous methanol with an absorption maximum at 335 nm played a minor role. Thus, cells are protected against potentially high levels of UV radiation by the snow itself when they live several centimeters beneath the surface, and they rely on cellular screening compounds, chiefly astaxanthin, when located near the surface where UV fluxes are high.

Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

NASA Astrophysics Data System (ADS)

Poillucci, Richard

Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an automated fiber placement machine and the successful fabrication of a carbon fiber plate with an integrated microvascular channel is demonstrated.

High-throughput process development of an alternative platform for the production of virus-like particles in Escherichia coli.

PubMed

Ladd Effio, Christopher; Baumann, Pascal; Weigel, Claudia; Vormittag, Philipp; Middelberg, Anton; Hubbuch, Jürgen

2016-02-10

The production of safe vaccines against untreatable or new diseases has pushed the research in the field of virus-like particles (VLPs). Currently, a large number of commercial VLP-based human vaccines and vaccine candidates are available or under development. A promising VLP production route is the controlled in vitro assembly of virus proteins into capsids. In the study reported here, a high-throughput screening (HTS) procedure was implemented for the upstream process development of a VLP platform in bacterial cell systems. Miniaturized cultivations were carried out in 48-well format in the BioLector system (m2p-Labs, Germany) using an Escherichia coli strain with a tac promoter producing the murine polyomavirus capsid protein (VP1). The screening procedure incorporated micro-scale cultivations, HTS cell disruption by sonication and HTS-compatible analytics by capillary gel electrophoresis. Cultivation temperatures, shaking speeds, induction and medium conditions were varied to optimize the product expression in E. coli. The most efficient system was selected based on an evaluation of soluble and insoluble product concentrations as well as on the percentage of product in the total soluble protein fraction. The optimized system was scaled up to cultivation 2.5L shaker flask scale and purified using an anion exchange chromatography membrane adsorber, followed by a size exclusion chromatography polishing procedure. For proof of concept, purified VP1 capsomeres were assembled under defined buffer conditions into empty capsids and characterized using transmission electron microscopy (TEM). The presented HTS procedure allowed for a fast development of an efficient production process of VLPs in E. coli. Under optimized cultivation conditions, the VP1 product totalled up to 43% of the total soluble protein fraction, yielding 1.63 mg VP1 per mL of applied cultivation medium. The developed production process strongly promotes the murine polyoma-VLP platform, moving towards an industrially feasible technology for new chimeric vaccines. Copyright © 2015 Elsevier B.V. All rights reserved.

Proteome screening of pleural effusions identifies galectin 1 as a diagnostic biomarker and highlights several prognostic biomarkers for malignant mesothelioma.

PubMed

Mundt, Filip; Johansson, Henrik J; Forshed, Jenny; Arslan, Sertaç; Metintas, Muzaffer; Dobra, Katalin; Lehtiö, Janne; Hjerpe, Anders

2014-03-01

Malignant mesothelioma is an aggressive asbestos-induced cancer, and affected patients have a median survival of approximately one year after diagnosis. It is often difficult to reach a conclusive diagnosis, and ancillary measurements of soluble biomarkers could increase diagnostic accuracy. Unfortunately, few soluble mesothelioma biomarkers are suitable for clinical application. Here we screened the effusion proteomes of mesothelioma and lung adenocarcinoma patients to identify novel soluble mesothelioma biomarkers. We performed quantitative mass-spectrometry-based proteomics using isobaric tags for quantification and used narrow-range immobilized pH gradient/high-resolution isoelectric focusing (pH 4-4.25) prior to analysis by means of nano liquid chromatography coupled to MS/MS. More than 1,300 proteins were identified in pleural effusions from patients with malignant mesothelioma (n = 6), lung adenocarcinoma (n = 6), or benign mesotheliosis (n = 7). Data are available via ProteomeXchange with identifier PXD000531. The identified proteins included a set of known mesothelioma markers and proteins that regulate hallmarks of cancer such as invasion, angiogenesis, and immune evasion, plus several new candidate proteins. Seven candidates (aldo-keto reductase 1B10, apolipoprotein C-I, galectin 1, myosin-VIIb, superoxide dismutase 2, tenascin C, and thrombospondin 1) were validated by enzyme-linked immunosorbent assays in a larger group of patients with mesothelioma (n = 37) or metastatic carcinomas (n = 25) and in effusions from patients with benign, reactive conditions (n = 16). Galectin 1 was identified as overexpressed in effusions from lung adenocarcinoma relative to mesothelioma and was validated as an excellent predictor for metastatic carcinomas against malignant mesothelioma. Galectin 1, aldo-keto reductase 1B10, and apolipoprotein C-I were all identified as potential prognostic biomarkers for malignant mesothelioma. This analysis of the effusion proteome furthers our understanding of malignant mesothelioma, identified galectin 1 as a potential diagnostic biomarker, and highlighted several possible prognostic biomarkers of this disease.

A Method for Identifying Small-Molecule Aggregators Using Photonic Crystal Biosensor Microplates

PubMed Central

Chan, Leo L.; Lidstone, Erich A.; Finch, Kristin E.; Heeres, James T.; Hergenrother, Paul J.; Cunningham, Brian T.

2010-01-01

Small molecules identified through high-throughput screens are an essential element in pharmaceutical discovery programs. It is now recognized that a substantial fraction of small molecules exhibit aggregating behavior leading to false positive results in many screening assays, typically due to nonspecific attachment to target proteins. Therefore, the ability to efficiently identify compounds within a screening library that aggregate can streamline the screening process by eliminating unsuitable molecules from further consideration. In this work, we show that photonic crystal (PC) optical biosensor microplate technology can be used to identify and quantify small-molecule aggregation. A group of aggregators and nonaggregators were tested using the PC technology, and measurements were compared with those gathered by three alternative methods: dynamic light scattering (DLS), an α-chymotrypsin colorimetric assay, and scanning electron microscopy (SEM). The PC biosensor measurements of aggregation were confirmed by visual observation using SEM, and were in general agreement with the α-chymotrypsin assay. DLS measurements, in contrast, demonstrated inconsistent readings for many compounds that are found to form aggregates in shapes, very different from the classical spherical particles assumed in DLS modeling. As a label-free detection method, the PC biosensor aggregation assay is simple to implement and provides a quantitative direct measurement of the mass density of material adsorbed to the transducer surface, whereas the microplate-based sensor format enables compatibility with high-throughput automated liquid-handling methods used in pharmaceutical screening. PMID:20930952

Phosphate removal from agricultural drainage water using an iron oxyhydroxide filter material

USDA-ARS?s Scientific Manuscript database

Phosphate discharged with agricultural drainage causes water quality degradation on local, regional, and national scales. Iron oxyhydroxide filter materials can potentially remove the soluble phosphate present in drainage waters. Laboratory saturated column experiments and preliminary small-scale ...

Selenium Treatment Technologies

EPA Science Inventory

Selenium (Se) is a metalloid that is a dietary requirement in small quantities, but toxic at higher quantities. It also is known to bioaccumulate. In oxic environments, it exists as selenate (+6) and selenite (+4), both of which are soluble. Selenite will sorb more strongly to...

Antioxidant phytochemicals in fresh produce: exploitation of genotype variation and advancements in analytical protocols

NASA Astrophysics Data System (ADS)

Manganaris, George A.; Goulas, Vlasios; Mellidou, Ifigeneia; Drogoudi, Pavlina

2017-12-01

Horticultural commodities (fruit and vegetables) are the major dietary source of several bioactive compounds of high nutraceutical value for humans, including polyphenols, carotenoids and vitamins. The aim of the current review was dual. Firstly, towards the eventual enhancement of horticultural crops with bio-functional compounds, the natural genetic variation in antioxidants found in different species and cultivar/genotypes is underlined. Notably, some landraces and/or traditional cultivars have been characterized by substantially higher phytochemical content, i.e. small tomato of Santorini island (cv. ‘Tomataki Santorinis’) possesses appreciably high amounts of ascorbic acid. The systematic screening of key bioactive compounds in a wide range of germplasm for the identification of promising genotypes and the restoration of key gene fractions from wild species and landraces may help in reducing the loss of agro-biodiversity, creating a healthier ‘gene pool’ as the basis of future adaptation. Towards this direction, large scale comparative studies in different cultivars/genotypes of a given species provide useful insights about the ones of higher nutritional value. Secondly, the advancements in the employment of analytical techniques to determine the antioxidant potential through a convenient, easy and fast way are outlined. Such analytical techniques include electron paramagnetic resonance (EPR) and infrared (IR) spectroscopy, electrochemical and chemometric methods, flow injection analysis (FIA), optical sensors and high resolution screening (HRS). Taking into consideration that fruits and vegetables are complex mixtures of water- and lipid-soluble antioxidants, the exploitation of chemometrics to develop “omics” platforms (i.e. metabolomics, foodomics) is a promising tool for researchers to decode and/or predict antioxidant activity of fresh produce. For industry, the use of cheap and rapid optical sensors and IR spectroscopy is recommended to estimate the antioxidant activity, hence legislation does not allow its correlation with health claims.

Antioxidant Phytochemicals in Fresh Produce: Exploitation of Genotype Variation and Advancements in Analytical Protocols.

PubMed

Manganaris, George A; Goulas, Vlasios; Mellidou, Ifigeneia; Drogoudi, Pavlina

2017-01-01

Horticultural commodities (fruit and vegetables) are the major dietary source of several bioactive compounds of high nutraceutical value for humans, including polyphenols, carotenoids and vitamins. The aim of the current review was dual. Firstly, toward the eventual enhancement of horticultural crops with bio-functional compounds, the natural genetic variation in antioxidants found in different species and cultivars/genotypes is underlined. Notably, some landraces and/or traditional cultivars have been characterized by substantially higher phytochemical content, i.e., small tomato of Santorini island (cv. "Tomataki Santorinis") possesses appreciably high amounts of ascorbic acid (AsA). The systematic screening of key bioactive compounds in a wide range of germplasm for the identification of promising genotypes and the restoration of key gene fractions from wild species and landraces may help in reducing the loss of agro-biodiversity, creating a healthier "gene pool" as the basis of future adaptation. Toward this direction, large scale comparative studies in different cultivars/genotypes of a given species provide useful insights about the ones of higher nutritional value. Secondly, the advancements in the employment of analytical techniques to determine the antioxidant potential through a convenient, easy and fast way are outlined. Such analytical techniques include electron paramagnetic resonance (EPR) and infrared (IR) spectroscopy, electrochemical, and chemometric methods, flow injection analysis (FIA), optical sensors, and high resolution screening (HRS). Taking into consideration that fruits and vegetables are complex mixtures of water- and lipid-soluble antioxidants, the exploitation of chemometrics to develop "omics" platforms (i.e., metabolomics, foodomics) is a promising tool for researchers to decode and/or predict antioxidant activity of fresh produce. For industry, the use of optical sensors and IR spectroscopy is recommended to estimate the antioxidant activity rapidly and at low cost, although legislation does not allow its correlation with health claims.

Entropic effects in the electric double layer of model colloids with size-asymmetric monovalent ions

NASA Astrophysics Data System (ADS)

Guerrero-García, Guillermo Iván; González-Tovar, Enrique; Olvera de la Cruz, Mónica

2011-08-01

The structure of the electric double layer of charged nanoparticles and colloids in monovalent salts is crucial to determine their thermodynamics, solubility, and polyion adsorption. In this work, we explore the double layer structure and the possibility of charge reversal in relation to the size of both counterions and coions. We examine systems with various size-ratios between counterions and coions (ion size asymmetries) as well as different total ion volume fractions. Using Monte Carlo simulations and integral equations of a primitive-model electric double layer, we determine the highest charge neutralization and electrostatic screening near the electrified surface. Specifically, for two binary monovalent electrolytes with the same counterion properties but differing only in the coion's size surrounding a charged nanoparticle, the one with largest coion size is found to have the largest charge neutralization and screening. That is, in size-asymmetric double layers with a given counterion's size the excluded volume of the coions dictates the adsorption of the ionic charge close to the colloidal surface for monovalent salts. Furthermore, we demonstrate that charge reversal can occur at low surface charge densities, given a large enough total ion concentration, for systems of monovalent salts in a wide range of ion size asymmetries. In addition, we find a non-monotonic behavior for the corresponding maximum charge reversal, as a function of the colloidal bare charge. We also find that the reversal effect disappears for binary salts with large-size counterions and small-size coions at high surface charge densities. Lastly, we observe a good agreement between results from both Monte Carlo simulations and the integral equation theory across different colloidal charge densities and 1:1-elec-trolytes with different ion sizes.

Treatment Options by Stage (Non-Small Cell Lung Cancer)

MedlinePlus

... Cancer Prevention Lung Cancer Screening Research Non-Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Non-Small Cell Lung Cancer Go to Health Professional Version Key ...

Soluble interleukin 2 receptors are released from activated human lymphoid cells in vitro

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

Rubin, L.A.; Kurman, C.C.; Fritz, M.E.

1985-11-01

With the use of an enzyme-linked immunoabsorbent assay to measure soluble human interleukin 2 receptors (IL 2R), certain human T cell leukemia virus I (HTLV I)-positive T cell lines were found to spontaneously release large quantities of IL 2R into culture supernatants. This was not found with HTLV I-negative and IL 2 independent T cell lines, and only one of seven B cell-derived lines examined produced small amounts of IL 2R. In addition to this constitutive production of soluble IL 2R by certain cell lines, normal human peripheral blood mononuclear cells (PBMC) could be induced to release soluble IL 2Rmore » by plant lectins, the murine monoclonal antibody OKT3, tetanus toxoid, and allogeneic cells. Such activated cells also expressed cellular IL 2R measurable in detergent solubilized cell extracts. The generation of cellular and supernatant IL 2R was: dependent on cellular activation, rapid, radioresistant (3000 rad), and inhibited by cycloheximide treatment. NaDodSO4-polyacrylamide gel electrophoresis analysis of soluble IL 2R demonstrated molecules of apparent Mr = 35,000 to 40,000, and 45,000 to 50,000, respectively, somewhat smaller than the mature surface receptor on these cells. The release of soluble IL 2R appears to be a characteristic marker of T lymphocyte activation and might serve an immunoregulatory function during both normal and abnormal cell growth and differentiation.« less

Comparison of the aggregation of homologous β2-microglobulin variants reveals protein solubility as a key determinant of amyloid formation

PubMed Central

Pashley, Clare L.; Hewitt, Eric W.; Radford, Sheena E.

2016-01-01

The mouse and human β2-microglobulin protein orthologs are 70 % identical in sequence and share 88 % sequence similarity. These proteins are predicted by various algorithms to have similar aggregation and amyloid propensities. However, whilst human β2m (hβ2m) forms amyloid-like fibrils in denaturing conditions (e.g. pH 2.5) in the absence of NaCl, mouse β2m (mβ2m) requires the addition of 0.3 M NaCl to cause fibrillation. Here, the factors which give rise to this difference in amyloid propensity are investigated. We utilise structural and mutational analyses, fibril growth kinetics and solubility measurements under a range of pH and salt conditions, to determine why these two proteins have different amyloid propensities. The results show that, although other factors influence the fibril growth kinetics, a striking difference in the solubility of the proteins is a key determinant of the different amyloidogenicity of hβ2m and mβ2m. The relationship between protein solubility and lag time of amyloid formation is not captured by current aggregation or amyloid prediction algorithms, indicating a need to better understand the role of solubility on the lag time of amyloid formation. The results demonstrate the key contribution of protein solubility in determining amyloid propensity and lag time of amyloid formation, highlighting how small differences in protein sequence can have dramatic effects on amyloid formation. PMID:26780548

Triptycene: A Nucleic Acid Three-Way Junction Binder Scaffold

NASA Astrophysics Data System (ADS)

Yoon, Ina

Nucleic acids play a critical role in many biological processes such as gene regulation and replication. The development of small molecules that modulate nucleic acids with sequence or structure specificity would provide new strategies for regulating disease states at the nucleic acid level. However, this remains challenging mainly because of the nonspecific interactions between nucleic acids and small molecules. Three-way junctions are critical structural elements of nucleic acids. They are present in many important targets such as trinucleotide repeat junctions related to Huntington's disease, a temperature sensor sigma32 in E. coli, Dengue virus, and HIV. Triptycene-derived small molecules have been shown to bind to nucleic acid three-way junctions, resulting from their shape complementary. To develop a better understanding of designing molecules for targeting different junctions, a rapid screening of triptycene-based small molecules is needed. We envisioned that the installation of a linker at C9 position of the bicyclic core would allow for a rapid solid phase diversification. To achieve this aim, we synthesized 9-substituted triptycene scaffolds by using two different synthetic routes. The first synthetic route installed the linker from the amidation reaction between carboxylic acid at C9 position of the triptycene and an amine linker, beta-alanine ethyl ester. This new 9-substituted triptycene scaffold was then attached to a 2-chlorotrityl chloride resin for solid-phase diversification. This enabled a rapid diversification and an easy purification of mono-, di-, and tri-peptide triptycene derivatives. The binding affinities of these compounds were investigated towards a (CAG)˙(CTG) trinucleotide repeat junction. In the modified second synthetic route, we utilized a combined Heck coupling/benzyne Diels-Alder strategy. This improved synthetic strategy reduced the number of steps and total reaction times, increased the overall yield, improved solubilities of intermediates, and provided a new regioisomer that was not observed in the previous synthesis. Through this investigation, we discovered new high-affinity lead compounds towards a d(CAG)·(CTG) trinucleotide repeat junction. In addition, we turned our attention to sigma 32 mRNA, which contains a RNA three-way junction in E. coli. We demonstrated that triptycene-based small molecules can modulate the heat shock response in E. coli..

Analysis of the diffraction effects for a multi-view autostereoscopic three-dimensional display system based on shutter parallax barriers with full resolution

NASA Astrophysics Data System (ADS)

Meng, Yang; Yu, Zhongyuan; Jia, Fangda; Zhang, Chunyu; Wang, Ye; Liu, Yumin; Ye, Han; Chen, Laurence Lujun

2017-10-01

A multi-view autostereoscopic three-dimensional (3D) system is built by using a 2D display screen and a customized parallax-barrier shutter (PBS) screen. The shutter screen is controlled dynamically by address driving matrix circuit and it is placed in front of the display screen at a certain location. The system could achieve densest viewpoints due to its specially optical and geometric design which is based on concept of "eye space". The resolution of 3D imaging is not reduced compared to 2D mode by using limited time division multiplexing technology. The diffraction effects may play an important role in 3D display imaging quality, especially when applied to small screen, such as iPhone screen etc. For small screen, diffraction effects may contribute crosstalk between binocular views, image brightness uniformity etc. Therefore, diffraction effects are analyzed and considered in a one-dimensional shutter screen model of the 3D display, in which the numerical simulation of light from display pixels on display screen through parallax barrier slits to each viewing zone in eye space, is performed. The simulation results provide guidance for criteria screen size over which the impact of diffraction effects are ignorable, and below which diffraction effects must be taken into account. Finally, the simulation results are compared to the corresponding experimental measurements and observation with discussion.

Photosynthetic biomineralization of radioactive Sr via microalgal CO2 absorption.

PubMed

Lee, Seung Yeop; Jung, Kwang-Hwan; Lee, Ju Eun; Lee, Keon Ah; Lee, Sang-Hyo; Lee, Ji Young; Lee, Jae Kwang; Jeong, Jong Tae; Lee, Seung-Yop

2014-11-01

Water-soluble radiostrontium ((90)Sr) was efficiently removed as a carbonate form through microalgal photosynthetic process. The immobilization of soluble (90)Sr radionuclide and production of highly-precipitable radio-strontianite ((90)SrCO3) biomineral are achieved by using Chlorella vulgaris, and the biologically induced mineralization drastically decreased the (90)Sr radioactivity in water to make the highest (90)Sr removal ever reported. The high-resolution microscopy revealed that the short-term removal of soluble (90)Sr by C. vulgaris was attributable to the rapid and selective carbonation of (90)Sr together with the consumption of dissolved CO2 during photosynthesis. A small amount of carbonate in water could act as Sr(2+) sinks through the particular ability of the microalga to make the carbonate mineral of Sr stabilized firmly at the surface site. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecularly designed water soluble, intelligent, nanosize polymeric carriers.

PubMed

Pişkin, Erhan

2004-06-11

Intelligent polymers, also referred as "stimuli-responsive polymers" undergo strong property changes (in shape, surface characteristics, solubility, etc.) when only small changes in their environment (changes in temperature, pH, ionic strength light, electrical and magnetic field, etc.). They have been used in several novel applications, drug delivery systems, tissue engineering scaffolds, bioseparation, biomimetic actuators, etc. The most popular member of these type of polymers is poly(N-isopropylacrylamide) (poly(NIPA)) which exhibits temperature-sensitive character, in which the polymer chains change from water-soluble coils to water-insoluble globules in aqueous solution as temperature increases above the lower critical solution temperature (LCST) of the polymer. Copolymerization of NIPA with acrylic acid (AAc) allows the synthesis of both pH and temperature-responsive copolymers. This paper summarizes some of our related studies in which NIPA and its copolymers were synthesized and used as intelligent carriers in diverse applications.

Quantitative ELISAs for serum soluble LHCGR and hCG-LHCGR complex: potential diagnostics in first trimester pregnancy screening for stillbirth, Down’s syndrome, preterm delivery and preeclampsia

PubMed Central

2012-01-01

Background Soluble LH/hCG receptor (sLHCGR) released from placental explants and transfected cells can be detected in sera from pregnant women. To determine whether sLHCGR has diagnostic potential, quantitative ELISAs were developed and tested to examine the correlation between pregnancy outcome and levels of serum sLHCGR and hCG-sLHCGR complex. Methods Anti-LHCGR poly- and monoclonal antibodies recognizing defined LHCGR epitopes, commerical anti-hCGbeta antibody, together with recombinant LHCGR and yoked hCGbeta-LHCGR standard calibrators were used to develop two ELISAs. These assays were employed to quantify serum sLHCGR and hCG-sLHCGR at first trimester human pregnancy. Results Two ELISAs were developed and validated. Unlike any known biomarker, sLHCGR and hCG-sLHCGR are unique because Down’s syndrome (DS), preeclampsia and preterm delivery are linked to both low (less than or equal to 5 pmol/mL), and high (equal to or greater than 170 pmol/mL) concentrations. At these cut-off values, serum hCG-sLHCGR together with PAPP-A detected additional DS pregnancies (21%) which were negative by free hCGbeta plus PAPP-A screening procedure. Therefore, sLHCGR/hCG-sLHCGR has an additive effect on the current primary biochemical screening of aneuploid pregnancies. More than 88% of pregnancies destined to end in fetal demise (stillbirth) exhibited very low serum hCG-sLHCGR(less than or equal to 5 pmol/mL) compared to controls (median 16.15 pmol/mL, n = 390). The frequency of high hCG-sLHCGR concentrations (equal to or greater than 170 pmol/mL) in pathological pregnancies was at least 3-6-fold higher than that of the control, suggesting possible modulation of the thyrotropic effect of hCG by sLHCGR. Conclusions Serum sLHCGR/hCG-sLHCGR together with PAPP-A, have significant potential as first trimester screening markers for predicting pathological outcomes in pregnancy. PMID:23245345

Analysis of Anion Distributions in the Developing Strata of a Constructed Wetland Used for Chlorinated Ethene Remediation

DTIC Science & Technology

2003-03-01

and landfills. Classified as dense non-aqueous phase liquids (DNAPLs) because of their high density and relatively low solubility in water ...Environmental Protection Agency (EPA) recommendations (U.S. EPA, 1992). Water was purged from the top of the piezometric head, to ensure full...that which is recognized by the EPA as “ low -flow purging,” fresh water within the well screen was hydraulically isolated from any stagnant water in the

A Family of LIC Vectors for High-Throughput Cloning and Purification of Proteins1

PubMed Central

Eschenfeldt, William H.; Stols, Lucy; Millard, Cynthia Sanville; Joachimiak, Andrzej; Donnelly, Mark I.

2009-01-01

Summary Fifteen related ligation-independent cloning vectors were constructed for high-throughput cloning and purification of proteins. The vectors encode a TEV protease site for removal of tags that facilitate protein purification (his-tag) or improve solubility (MBP, GST). Specialized vectors allow coexpression and copurification of interacting proteins, or in vivo removal of MBP by TVMV protease to improve screening and purification. All target genes and vectors are processed by the same protocols, which we describe here. PMID:18988021

Incidence of elbow injuries in adolescent baseball players: screening by a low field magnetic resonance imaging system specialized for small joints.

PubMed

Okamoto, Yoshikazu; Maehara, Kiyoshi; Kanahori, Tetsuya; Hiyama, Takashi; Kawamura, Takashi; Minami, Manabu

2016-04-01

The aim of this preliminary study was to examine the capability of screening for elbow injuries induced by baseball using a low field small joint MRI system. Sixty-two players in the 4th-6th elementary school grades, with ages ranging from 9 to 12 years, participated in this study. Screening for elbow injuries was performed using a low-magnetic-field (0.2-T) magnetic resonance imaging (MRI) system designed for examinations of small joints of the extremities. Gradient-echo coronal, sagittal, and short-tau inversion recovery (STIR) coronal images of the dominant arm used for pitching were obtained to identify medial collateral ligament (MCL) injuries with or without avulsion fracture and osteochondritis dissecans. All 62 examinations were performed successfully, with 26 players (41.9 %) showing positive findings, all being confined to the MCL. No child showed bone damage. All criteria in the MRI evaluation of injuries showed high agreement rates and kappa values between two radiologists. Screening for early detection of elbow injuries in junior Japanese baseball players can be successfully performed using a low-field MRI system specialized for small joints. The percentage of MCL injury without avulsion fracture was unexpectedly high (41.9 %).

The interdependence between screening methods and screening libraries.

PubMed

Shelat, Anang A; Guy, R Kiplin

2007-06-01

The most common methods for discovery of chemical compounds capable of manipulating biological function involves some form of screening. The success of such screens is highly dependent on the chemical materials - commonly referred to as libraries - that are assayed. Classic methods for the design of screening libraries have depended on knowledge of target structure and relevant pharmacophores for target focus, and on simple count-based measures to assess other properties. The recent proliferation of two novel screening paradigms, structure-based screening and high-content screening, prompts a profound rethink about the ideal composition of small-molecule screening libraries. We suggest that currently utilized libraries are not optimal for addressing new targets by high-throughput screening, or complex phenotypes by high-content screening.

Post-meal perceivable satiety and subsequent energy intake with intake of partially hydrolysed guar gum.

PubMed

Rao, Theertham Pradyumna; Hayakawa, Mariko; Minami, Tadayasu; Ishihara, Noriyuki; Kapoor, Mahendra Parkash; Ohkubo, Tsutomu; Juneja, Lekh Raj; Wakabayashi, Kazuo

2015-05-14

Partially hydrolysed guar gum (PHGG), a soluble dietary fibre, has been shown to provide many health benefits. Previous studies had suggested that the combination of PHGG with protein provided a significant satiation effect on visual analogue scales (VAS). What was lacking was only the effect of administration of small doses of PHGG on post-meal satiation and subsequent energy intake. The objectives of the present investigations were to find the subjective perception of post-meal satiety with acute and long term administration of small amounts of PHGG alone with food, its effects on subsequent energy intake and the comparative effects among different types of soluble fibres. The following three separate studies were conducted: in study 1, healthy subjects (n 12) consumed PHGG along with breakfast, lunch and an evening snack; in study 2, healthy subjects (n 24) consumed 2 g of PHGG or dextrin along with yogurt as breakfast for 2 weeks; in study 3, healthy subjects (n 6) took 6 g each of either PHGG or indigestible dextrin or inulin along with lunch. In all the studies, various satiety parameters were measured on VAS before and after consumption of PHGG. The addition of PHGG showed significant (P < 0.05) acute (studies 1 and 3) and long-term (studies 1 and 2) satiety effects compared to the control and/or an equal amount of carbohydrate or other types of soluble fibre. Study 2 also indicated that the prolonged consumption of PHGG may significantly (P < 0.05) reduce energy intake from whole-day snacking. PHGG could be an ideal natural soluble fibre for delivering acute and long term satiety effects for comfortable appetite control.

Speciation and equilibrium relations of soluble aluminum in a headwater stream at base flow and during rain events

USGS Publications Warehouse

Burns, Douglas A.

1989-01-01

In a small watershed in the Shenandoah National Park, Virginia, the short-term dynamics of soluble aluminum in stream water sampled during rain events differed significantly from stream water sampled during base flow conditions. Three fractions of dissolved aluminum were measured. The inorganic monomeric fraction made up approximately two thirds of the total reactive aluminum at base flow, followed by the acid-soluble and organic monomeric fractions, respectively. Equilibrium modeling showed that hydroxide complexes were the most abundant form of inorganic monomeric aluminum followed by fluoride, free aluminum ion, and sulfate. The activity of inorganic monomeric aluminum at base flow appears to be in equilibrium with an Al(OH)3 phase with solubility intermediate between microcrystalline gibbsite and natural gibbsite. During two rain events, the concentration of all three aluminum fractions increased significantly. Available chemical evidence indicates that acidic soil water was the primary source of dissolved aluminum. As flow increased, the Al(OH)3 saturation index in the stream water increased significantly. The primary cause of the transient increase in the Al(OH)3 saturation index appears to have been the neutralization of excess H+ added by soil water through reaction with stream water HCO3− at a more rapid rate than excess inorganic monomeric aluminum could be removed from solution by hydroxide mineral precipitation. A soil water/stream water mixing model was developed based on measured changes of stream water alkalinity, silica concentration, and charge imbalance during the rain events. Model results indicate that a small amount of soil water (3–11%) was present in the stream at peak stage.

A comprehensive review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes

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

Caffrey, Martin, E-mail: martin.caffrey@tcd.ie

A comprehensive and up-to-date review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes is reported. Recent applications of the method for in situ serial crystallography at X-ray free-electron lasers and synchrotrons are described. The lipid cubic phase or in meso method is a robust approach for crystallizing membrane proteins for structure determination. The uptake of the method is such that it is experiencing what can only be described as explosive growth. This timely, comprehensive and up-to-date review introduces the reader to the practice of in meso crystallogenesis, to the associated challengesmore » and to their solutions. A model of how crystallization comes about mechanistically is presented for a more rational approach to crystallization. The possible involvement of the lamellar and inverted hexagonal phases in crystallogenesis and the application of the method to water-soluble, monotopic and lipid-anchored proteins are addressed. How to set up trials manually and automatically with a robot is introduced with reference to open-access online videos that provide a practical guide to all aspects of the method. These range from protein reconstitution to crystal harvesting from the hosting mesophase, which is noted for its viscosity and stickiness. The sponge phase, as an alternative medium in which to perform crystallization, is described. The compatibility of the method with additive lipids, detergents, precipitant-screen components and materials carried along with the protein such as denaturants and reducing agents is considered. The powerful host and additive lipid-screening strategies are described along with how samples that have low protein concentration and cell-free expressed protein can be used. Assaying the protein reconstituted in the bilayer of the cubic phase for function is an important element of quality control and is detailed. Host lipid design for crystallization at low temperatures and for large proteins and complexes is outlined. Experimental phasing by heavy-atom derivatization, soaking or co-crystallization is routine and the approaches that have been implemented to date are described. An overview and a breakdown by family and function of the close to 200 published structures that have been obtained using in meso-grown crystals are given. Recommendations for conducting the screening process to give a more productive outcome are summarized. The fact that the in meso method also works with soluble proteins should not be overlooked. Recent applications of the method for in situ serial crystallography at X-ray free-electron lasers and synchrotrons are described. The review ends with a view to the future and to the bright prospects for the method, which continues to contribute to our understanding of the molecular mechanisms of some of nature’s most valued proteinaceous robots.« less

Paecilomyces tabacinus

USDA-ARS?s Scientific Manuscript database

Culture characteristics - (in the dark, 25 °C after 7 d): Colonies on MEA 30–31 mm diam, velutinous to slightly floccose, mycelium white, sporulation abundant, cream-buff [R30; Ridgway (1912)], exudate clear, small droplets dominate, soluble pigments not observed, reverse cream-buff to chamois (R30)...

Rasamsonia columbiensis

USDA-ARS?s Scientific Manuscript database

Culture characteristics - (in the dark, 25 °C after 7 d): Colonies on MEA 30–31 mm diam, velutinous to slightly floccose, mycelium white, sporulation abundant, cream-buff [R30; Ridgway (1912)], exudate clear, small droplets dominate, soluble pigments not observed, reverse cream-buff to chamois (R30)...

Fat-soluble vitamin deficiency in children and adolescents with cystic fibrosis.

PubMed

Rana, Malay; Wong-See, Denise; Katz, Tamarah; Gaskin, Kevin; Whitehead, Bruce; Jaffe, Adam; Coakley, John; Lochhead, Alistair

2014-07-01

Determine the prevalence of fat-soluble vitamin deficiency in children with cystic fibrosis (CF) aged ≤18 years in New South Wales (NSW), Australia, from 2007 to 2010. A retrospective analysis of fat-soluble vitamin levels in children aged ≤18 years who lived in NSW and attended any of the three paediatric CF centres from 2007 to 2010. An audit of demographic and clinical data during the first vitamin level measurement of the study period was performed. Deficiency of one or more fat-soluble vitamins was present in 240/530 children (45%) on their first vitamin level test in the study period. The prevalence of vitamins D and E deficiency fell from 22.11% in 2007 to 15.54% in 2010, and 20.22% to 13.89%, respectively. The prevalence of vitamin A deficiency increased from 11.17% to 13.13%. Low vitamin K was present in 29% in 2007, and prevalence of prolonged prothrombin time increased from 19.21% to 22.62%. Fat-soluble vitamin deficiency is present in 10%-35% of children with pancreatic insufficiency, but only a very small proportion of children who are pancreatic-sufficient. This is one of few studies of fat-soluble vitamin deficiency in children with CF in Australia. Fat-soluble vitamin testing is essential to identify deficiency in pancreatic-insufficient children who may be non-compliant to supplementation or require a higher supplement dose, and pancreatic-sufficient children who may be progressing to insufficiency. Testing of vitamin K-dependent factors needs consideration. Further studies are needed to monitor rates of vitamin deficiency in the CF community. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A novel method for determining the solubility of small molecules in aqueous media and polymer solvent systems using solution calorimetry.

PubMed

Fadda, Hala M; Chen, Xin; Aburub, Aktham; Mishra, Dinesh; Pinal, Rodolfo

2014-07-01

To explore the application of solution calorimetry for measuring drug solubility in experimentally challenging situations while providing additional information on the physical properties of the solute material. A semi-adiabatic solution calorimeter was used to measure the heat of dissolution of prednisolone and chlorpropamide in aqueous solvents and of griseofulvin and ritonavir in viscous solutions containing polyvinylpyrrolidone and N-ethylpyrrolidone. Dissolution end point was clearly ascertained when heat generation stopped. The heat of solution was a linear function of dissolved mass for all drugs (<10% RSD, except for chlorpropamide). Heats of solution of 9.8 ± 0.8, 28.8 ± 0.6, 45.7 ± 1.6 and 159.8 ± 20.1 J/g were obtained for griseofulvin, ritonavir, prednisolone and chlorpropamide, respectively. Saturation was identifiable by a plateau in the heat signal and the crossing of the two linear segments corresponds to the solubility limit. The solubilities of prednisolone and chlopropamide in water by the calorimetric method were 0.23 and 0.158 mg/mL, respectively, in agreement with the shake-flask/HPLC-UV determined values of 0.212 ± 0.013 and 0.169 ± 0.015 mg/mL, respectively. For the higher solubility and high viscosity systems of griseofulvin and ritonavir in NEP/PVP mixtures, respectively, solubility values of 65 and 594 mg/g, respectively, were obtained. Solution calorimetry offers a reliable method for measuring drug solubility in organic and aqueous solvents. The approach is complementary to the traditional shake-flask method, providing information on the solid properties of the solute. For highly viscous solutions, the calorimetric approach is advantageous.

ScreenCube: A 3D Printed System for Rapid and Cost-Effective Chemical Screening in Adult Zebrafish.

PubMed

Monstad-Rios, Adrian T; Watson, Claire J; Kwon, Ronald Y

2018-02-01

Phenotype-based small molecule screens in zebrafish embryos and larvae have been successful in accelerating pathway and therapeutic discovery for diverse biological processes. Yet, the application of chemical screens to adult physiologies has been relatively limited due to additional demands on cost, space, and labor associated with screens in adult animals. In this study, we present a 3D printed system and methods for intermittent drug dosing that enable rapid and cost-effective chemical administration in adult zebrafish. Using prefilled screening plates, the system enables dosing of 96 fish in ∼3 min, with a 10-fold reduction in drug quantity compared to that used in previous chemical screens in adult zebrafish. We characterize water quality kinetics during immersion in the system and use these kinetics to rationally design intermittent dosing regimens that result in 100% fish survival. As a demonstration of system fidelity, we show the potential to identify two known chemical inhibitors of adult tail fin regeneration, cyclopamine and dorsomorphin. By developing methods for rapid and cost-effective chemical administration in adult zebrafish, this study expands the potential for small molecule discovery in postembryonic models of development, disease, and regeneration.

Identification of novel drug scaffolds for inhibition of SARS-CoV 3-Chymotrypsin-like protease using virtual and high-throughput screenings.

PubMed

Lee, Hyun; Mittal, Anuradha; Patel, Kavankumar; Gatuz, Joseph L; Truong, Lena; Torres, Jaime; Mulhearn, Debbie C; Johnson, Michael E

2014-01-01

We have used a combination of virtual screening (VS) and high-throughput screening (HTS) techniques to identify novel, non-peptidic small molecule inhibitors against human SARS-CoV 3CLpro. A structure-based VS approach integrating docking and pharmacophore based methods was employed to computationally screen 621,000 compounds from the ZINC library. The screening protocol was validated using known 3CLpro inhibitors and was optimized for speed, improved selectivity, and for accommodating receptor flexibility. Subsequently, a fluorescence-based enzymatic HTS assay was developed and optimized to experimentally screen approximately 41,000 compounds from four structurally diverse libraries chosen mainly based on the VS results. False positives from initial HTS hits were eliminated by a secondary orthogonal binding analysis using surface plasmon resonance (SPR). The campaign identified a reversible small molecule inhibitor exhibiting mixed-type inhibition with a K(i) value of 11.1 μM. Together, these results validate our protocols as suitable approaches to screen virtual and chemical libraries, and the newly identified compound reported in our study represents a promising structural scaffold to pursue for further SARS-CoV 3CLpro inhibitor development. Copyright © 2013. Published by Elsevier Ltd.

Evaluation of the composition of the binder bridges in matrix granules prepared with a small-scale high-shear granulator.

PubMed

Bajdik, János; Baki, Gabriella; Szent-Királlyi, Zsuzsanna; Knop, Klaus; Kleinebudde, Peter; Pintye-Hódi, Klára

2008-11-04

The aim of this work was to evaluate the binder bridges which can form in hydrophilic matrix granules prepared with a small-scale high-shear granulator. Matrices contained hydroxypropyl methylcellulose (HPMC) as a matrix-forming agent, together with lactose monohydrate and microcrystalline cellulose as filler. Water was used as granulating liquid. A 2(4) full factorial design was used to evaluate the effects of the operational parameters (impeller speed, chopper speed, dosing speed and wet massing time) on the granulation process. The temperature of the sample increased relevantly during the preparation in the small-scale apparatus. The same setup induced different temperature increases for different amounts of powder. This alteration enhances the solubility of lactose and decreases that of HPMC, and thus the quantities of the dissolved components can vary. Accordingly, changes in composition of the binder bridge can occur. Since exact determination of the dissolution of these materials during granulation is difficult, the consequences of the changes in solubility were examined. Differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and X-ray diffraction (XRD) measurements were made to evaluate the films prepared from liquids with different ratios of soluble materials. The DSC and XRD measurements confirmed that the lactose lost its crystalline state in the film. The TMA tests revealed that increase of the quantity of lactose in the film decreased the glass transition temperature of the film; this may be attributed to the interaction of the additives. At a lactose content of 37.5%, a second glass transition appeared. This phenomenon may be indicative of a separate amorphous lactose phase.

A virtual screening method for inhibitory peptides of Angiotensin I-converting enzyme.

PubMed

Wu, Hongxi; Liu, Yalan; Guo, Mingrong; Xie, Jingli; Jiang, XiaMin

2014-09-01

Natural small peptides from foods have been proven to be efficient inhibitors of Angiotensin I-converting enzyme (ACE) for the regulation of blood pressure. The traditional ACE inhibitory peptides screening method is both time consuming and money costing, to the contrary, virtual screening method by computation can break these limitations. We establish a virtual screening method to obtain ACE inhibitory peptides with the help of Libdock module of Discovery Studio 3.5 software. A significant relationship between Libdock score and experimental IC(50) was found, Libdock score = 10.063 log(1/IC(50)) + 68.08 (R(2) = 0.62). The credibility of the relationship was confirmed by testing the coincidence of the estimated log(1/IC(50)) and measured log(1/IC(50)) (IC(50) is 50% inhibitory concentration toward ACE, in μmol/L) of 5 synthetic ACE inhibitory peptides, which was virtual hydrolyzed and screened from a kind of seafood, Phascolosoma esculenta. Accordingly, Libdock method is a valid IC(50) estimation tool and virtual screening method for small ACE inhibitory peptides. © 2014 Institute of Food Technologists®

Effects of Aging and Domain Knowledge on Usability in Small Screen Devices for Diabetes Patients

NASA Astrophysics Data System (ADS)

Calero Valdez, André; Ziefle, Martina; Horstmann, Andreas; Herding, Daniel; Schroeder, Ulrik

Technology acceptance has become a key concept for the successful rollout of technical devices. Though the concept is intensively studied for nearly 20 years now, still, many open questions remain. This especially applies to technology acceptance of older users, which are known to be very sensitive to suboptimal interfaces and show considerable reservations towards the usage of new technology. Mobile small screen technology increasingly penetrates health care and medical applications. This study investigates impacts of aging, technology expertise and domain knowledge on user interaction using the example of diabetes. For this purpose user effectiveness and efficiency have been measured on a simulated small screen device and related to user characteristics, showing that age and technology expertise have a big impact on usability of the device. Furthermore, impacts of user characteristics and success during the trial on acceptance of the device were surveyed and analyzed.

Evaluation of a water-soluble contrast agent for the conservative management of adhesive small bowel obstruction in pediatric patients.

PubMed

Lee, Chee-Yew; Hung, Min-Hsuan; Lin, Lung-Huang; Chen, Der-Fang

2015-04-01

The diagnostic and therapeutic benefits of a commercial water-soluble contrast agent (Gastrografin) in pediatric patients with adhesive small-bowel obstruction (ASBO) are controversial. The aim of this study was to assess the therapeutic value of Gastrografin in the management of ASBO in children after unsuccessful conservative treatment. Medical records from patients with uncomplicated ASBO managed at Cathay General Hospital, Taipei, Taiwan between January 1996 and December 2011 were retrospectively reviewed. All children ≤18 years of age with clinical evidence of ASBO were managed conservative treatment, unless there was suspicion of strangulation. Patients who did not improve after 48 hours of conservative treatment were administered Gastrografin. Twenty-four patients with 33 episodes of ASBO were analyzed. Of those, there were 19 episodes of ASBO that failed to respond to the initial conservative management, and 16 (84%) responded well to Gastrografin administration thereby abrogating the need for surgical intervention. There were neither complications nor mortality that could be attributed to the use of Gastrografin. This preliminary study suggested that the use of a water-soluble contrast agent in ASBO is safe in children and useful for managing ASBO, particularly in reducing the need for surgery when conservative treatment fails. However, larger prospective studies would be needed to confirm these results. Copyright © 2015 Elsevier Inc. All rights reserved.

Systematic review and meta-analysis of the diagnostic and therapeutic role of water-soluble contrast agent in adhesive small bowel obstruction.

PubMed

Branco, B C; Barmparas, G; Schnüriger, B; Inaba, K; Chan, L S; Demetriades, D

2010-04-01

This meta-analysis assessed the diagnostic and therapeutic role of water-soluble contrast agent (WSCA) in adhesive small bowel obstruction (SBO). PubMed, Embase and Cochrane databases were searched systematically. The primary outcome in the diagnostic role of WSCA was its ability to predict the need for surgery. In the therapeutic role, the following were evaluated: resolution of SBO without surgery, time from admission to resolution, duration of hospital stay, complications and mortality. To assess the diagnostic role of WSCA, pooled estimates of sensitivity, specificity, positive and negative predictive values, and likelihood ratios were derived. For the therapeutic role of WSCA, weighted odds ratio (OR) and weighted mean difference (WMD) were obtained. Fourteen prospective studies were included. The appearance of contrast in the colon within 4-24 h after administration had a sensitivity of 96 per cent and specificity of 98 per cent in predicting resolution of SBO. WSCA administration was effective in reducing the need for surgery (OR 0.62; P = 0.007) and shortening hospital stay (WMD -1.87 days; P < 0.001) compared with conventional treatment. Water-soluble contrast was effective in predicting the need for surgery in patients with adhesive SBO. In addition, it reduced the need for operation and shortened hospital stay. Copyright (c) 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Soluble arabinoxylan alters digesta flow and protein digestion of red meat-containing diets in pigs.

PubMed

Zhang, Dagong; Williams, Barbara A; Mikkelsen, Deirdre; Li, Xiuhua; Keates, Helen L; Lisle, Allan T; Collins, Helen M; Fincher, Geoffrey B; Bird, Anthony R; Topping, David L; Gidley, Michael J; Bryden, Wayne L

2015-09-01

The aim of this study was to investigate how a moderate increase in dietary meat content combined (or not) with soluble fibre would influence protein digestion as well as digesta characteristics and flow. Four groups of pigs were fed Western-style diets (high-protein/high-fat) containing two types of barbecued red meat, one with and one without a wheat arabinoxylan-rich fraction. After 4 wk, digesta samples were collected from small and large intestinal sites and analyzed for protein, amino acids, dry matter, and acid-insoluble ash. Tissue samples were also collected from each site. Arabinoxylan consumption led to somewhat lower apparent protein digestibility within the small and large intestines as well as shorter mean retention times. This suggests that the lowered protein digestibility is due, at least partly, to shorter access time to digestive proteases and absorptive surfaces. Additionally, digesta mass was higher in pigs fed arabinoxylan while dry matter (%) was lower, indicating an increased digesta water-holding capacity due to the presence of a soluble dietary fiber. Data showed that solubilized wheat arabinoxylan provides potential health benefits through decreased protein digestibility, increased digesta mass, and reduced mean retention time, even for diets with a moderately higher protein content. These factors are associated with efficiency of digestion and satiety, both of which have implications for prevention of obesity and other health disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaporative concentration of skimmed milk: effect on casein micelle hydration, composition, and size.

PubMed

Liu, Dylan Z; Dunstan, David E; Martin, Gregory J O

2012-10-01

Understanding the effect of evaporative concentration on casein micelle composition is of high importance for milk processing. Alterations to the hydration, composition and size of casein micelles were investigated in skimmed milk evaporated to concentrations of 12-45% total solids content. The size of casein micelles was determined by dynamic light scattering, and the water content and composition determined by analysis of supernatants and pellets obtained by ultracentrifugation. The mass balance and hydration results showed that during the evaporation process, while micelles were dehydrated, water was removed preferentially from the serum. The amount of soluble casein and calcium in the serum decreased as a function of increasing solids content, indicating a shift of these components to the micelles. The formation of a small proportion of micelle aggregates at high concentrations appeared dependent on the time kept at these concentrations. Upon redilution with water, casein micelles were immediately rehydrated and aggregates were broken up in a matter of minutes. Soluble calcium and pH returned to their original state over a number of hours; however, only a small percentage of original soluble casein returned to the serum over the 5h period investigated. These results showed that casein micelles are significantly affected by evaporative concentration and that the alterations are not completely and rapidly reversible. Copyright © 2012. Published by Elsevier Ltd.

Prefoldin Promotes Proteasomal Degradation of Cytosolic Proteins with Missense Mutations by Maintaining Substrate Solubility

PubMed Central

Young, Barry P.; Loewen, Christopher J.; Mayor, Thibault

2016-01-01

Misfolded proteins challenge the ability of cells to maintain protein homeostasis and can accumulate into toxic protein aggregates. As a consequence, cells have adopted a number of protein quality control pathways to prevent protein aggregation, promote protein folding, and target terminally misfolded proteins for degradation. In this study, we employed a thermosensitive allele of the yeast Guk1 guanylate kinase as a model misfolded protein to investigate degradative protein quality control pathways. We performed a flow cytometry based screen to identify factors that promote proteasomal degradation of proteins misfolded as the result of missense mutations. In addition to the E3 ubiquitin ligase Ubr1, we identified the prefoldin chaperone subunit Gim3 as an important quality control factor. Whereas the absence of GIM3 did not impair proteasomal function or the ubiquitination of the model substrate, it led to the accumulation of the poorly soluble model substrate in cellular inclusions that was accompanied by delayed degradation. We found that Gim3 interacted with the Guk1 mutant allele and propose that prefoldin promotes the degradation of the unstable model substrate by maintaining the solubility of the misfolded protein. We also demonstrated that in addition to the Guk1 mutant, prefoldin can stabilize other misfolded cytosolic proteins containing missense mutations. PMID:27448207

Understanding and optimizing the dual excipient functionality of sodium lauryl sulfate in tablet formulation of poorly water soluble drug: wetting and lubrication.

PubMed

Aljaberi, Ahmad; Chatterji, Ashish; Dong, Zedong; Shah, Navnit H; Malick, Waseem; Singhal, Dharmendra; Sandhu, Harpreet K

2013-01-01

To evaluate and optimize sodium lauryl sulfate (SLS) and magnesium stearate (Mg.St) levels, with respect to dissolution and compaction, in a high dose, poorly soluble drug tablet formulation. A model poorly soluble drug was formulated using high shear aqueous granulation. A D-optimal design was used to evaluate and model the effect of granulation conditions, size of milling screen, SLS and Mg.St levels on tablet compaction and ejection. The compaction profiles were generated using a Presster(©) compaction simulator. Dissolution of the kernels was performed using a USP dissolution apparatus II and intrinsic dissolution was determined using a stationary disk system. Unlike kernels dissolution which failed to discriminate between tablets prepared with various SLS contents, the intrinsic dissolution rate showed that a SLS level of 0.57% was sufficient to achieve the required release profile while having minimal effect on compaction. The formulation factors that affect tablet compaction and ejection were identified and satisfactorily modeled. The design space of best factor setting to achieve optimal compaction and ejection properties was successfully constructed by RSM analysis. A systematic study design helped identify the critical factors and provided means to optimize the functionality of key excipient to design robust drug product.

Mesoporous systems for poorly soluble drugs.

PubMed

Xu, Wujun; Riikonen, Joakim; Lehto, Vesa-Pekka

2013-08-30

Utilization of inorganic mesoporous materials in formulations of poorly water-soluble drugs to enhance their dissolution and permeation behavior is a rapidly growing area in pharmaceutical materials research. The benefits of mesoporous materials in drug delivery applications stem from their large surface area and pore volume. These properties enable the materials to accommodate large amounts of payload molecules, protect them from premature degradation, and promote controlled and fast release. As carriers with various morphologies and chemical surface properties can be produced, these materials may even promote adsorption from the gastrointestinal tract to the systemic circulation. The main concern regarding their clinical applications is still the safety aspect even though most of them have been reported to be safely excreted, and a rather extensive toxicity screening has already been conducted with the most frequently studied mesoporous materials. In addition, the production of the materials on a large scale and at a reasonable cost may be a challenge when considering the utilization of the materials in industrial processes. However, if mesoporous materials could be employed in the industrial crystallization processes to produce hybrid materials with poorly soluble compounds, and hence to enhance their oral bioavailability, this might open new avenues for the pharmaceutical industry to employ nanotechnology in their processes. Copyright © 2012 Elsevier B.V. All rights reserved.

Routine Use of Contrast Swallow After Total Gastrectomy and Esophagectomy: Is it Justified?

PubMed

El-Sourani, Nader; Bruns, Helge; Troja, Achim; Raab, Hans-Rudolf; Antolovic, Dalibor

2017-01-01

After gastrectomy or esophagectomy, esophagogastrostomy and esophagojejunostomy are commonly used for reconstruction. Water-soluble contrast swallow is often used as a routine screening to exclude anastomotic leakage during the first postoperative week. In this retrospective study, the sensitivity and specificity of oral water-soluble contrast swallow for the detection of anastomotic leakage and its clinical symptoms were analysed. Records of 104 consecutive total gastrectomies and distal esophagectomies were analysed. In all cases, upper gastrointestinal contrast swallow with the use of a water-soluble contrast agent was performed on the 5 th postoperative day. Extravasation of the contrast agent was defined as anastomotic leakage. When anastomotic insufficiency was suspected but no extravasation was present, a computed tomography (CT) scan and upper endoscopy were performed. Oral contrast swallow detected 7 anastomotic leaks. Based on CT-scans and upper endoscopy, the true number of anastomotic leakage was 15. The findings of the oral contrast swallow were falsely positive in 4 and falsely negative in 12 patients, respectively. The sensitivity and specificity of the oral contrast swallow was 20% and 96%, respectively. Routine radiological contrast swallow following total gastrectomy or distal esophagectomy cannot be recommended. When symptoms of anastomotic leakage are present, a CT-scan and endoscopy are currently the methods of choice.

Selection of ionic liquids for enhancing the gas solubility of volatile organic compounds.

PubMed

Gonzalez-Miquel, Maria; Palomar, Jose; Rodriguez, Francisco

2013-01-10

A systematic thermodynamic analysis has been carried out for selecting cations and anions to enhance the absorption of volatile organic compounds (VOCs) at low concentration in gaseous streams by ionic liquids (ILs), using COSMO-RS methodology. The predictability of computational procedure was validated by comparing experimental and COSMO-RS calculated Henry's law constant data over a sample of 125 gaseous solute-IL systems. For more than 2400 solute-IL mixtures evaluated, including 9 solutes and 270 ILs, it was found that the lower the activity coefficient at infinite dilution (γ(∞)) of solutes in the ILs, the more the exothermic excess enthalpy (H(E)) of the equimolar IL-solute mixtures. Then, the solubility of a representative sample of VOC solutes, with very different chemical nature, was screened in a wide number of ILs using COSMO-RS methodology by means of γ(∞) and H(E) parameters, establishing criteria to select the IL structures that promote favorable solute-solvent intermolecular interactions. As a result of this analysis, an attempt of classification of VOCs respect to their potential solubility in ILs was proposed, providing insights to rationally select the cationic and anionic species for a possible development of absorption treatments of VOC pollutants based on IL systems.

Triple effect absorption cycles

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

Erickson, D.C.; Potnis, S.V.; Tang, J.

1996-12-31

Triple effect absorption chillers can achieve 50% COP improvement over double-effect systems. However, to translate this potential into cost-effective hardware, the most promising embodiments must be identified. In this study, 12 generic triple effect cycles and 76 possible hermetic loop arrangements of those 12 generic cycles were identified. The generic triple effect cycles were screened based on their pressure and solubility field requirements, generic COPs, risk involved in the component design, and number of components in a high corrosive environment. This screening identified four promising arrangements: Alkitrate Topping cycle, Pressure Staged Envelope cycle, High Pressure Overlap cycle, and Dual Loopmore » cycle. All of these arrangements have a very high COP ({approximately} 1.8), however the development risk and cost involved is different for each arrangement. Therefore, the selection of a particular arrangement will depend upon the specific situation under consideration.« less

On the possibility of using polycrystalline material in the development of structure-based generic assays

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

Allaire, Marc, E-mail: allaire@bnl.gov; Moiseeva, Natalia; Botez, Cristian E.

The correlation coefficients calculated between raw powder diffraction profiles can be used to identify ligand-bound/unbound states of lysozyme. The discovery of ligands that bind specifically to a targeted protein benefits from the development of generic assays for high-throughput screening of a library of chemicals. Protein powder diffraction (PPD) has been proposed as a potential method for use as a structure-based assay for high-throughput screening applications. Building on this effort, powder samples of bound/unbound states of soluble hen-egg white lysozyme precipitated with sodium chloride were compared. The correlation coefficients calculated between the raw diffraction profiles were consistent with the known bindingmore » properties of the ligands and suggested that the PPD approach can be used even prior to a full description using stereochemically restrained Rietveld refinement.« less

Screening of polysaccharides from tamarind, fenugreek and jackfruit seeds as pharmaceutical excipients.

PubMed

Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

2015-08-01

The paper describes the isolation and screening of plant polysaccharides namely tamarind seed polysaccharide (TSP), fenugreek seed mucilage (FSM) and jackfruit seed starch (JFSS) from tamarind (Tamarindus indica L.) seeds, fenugreek (Trigonella foenum-graecum L.) seeds and jackfruit (Artocarpus heterophyllus L.) seeds, respectively. The yields of isolated dried TSP, FSM and JFSS were 47.00%, 17.36% and 18.86%, respectively. Various physicochemical properties like colour, odour, taste, solubility in water, pH and viscosity of these isolated plant polysaccharides were assessed. Isolated polysaccharide samples were subjected to some phytochemical identification tests. FTIR and (1)H NMR analyses of isolated polysaccharides were performed, which suggest the presence of sugar residues. Isolated TSP, FSM and JFSS can be used as pharmaceutical excipients in various pharmaceutical formulations. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance evaluation of phage-displayed synthetic human single-domain antibody libraries: A retrospective analysis.

PubMed

Henry, Kevin A; Tanha, Jamshid

2018-05-01

Fully human synthetic single-domain antibodies (sdAbs) are desirable therapeutic molecules but their development is a considerable challenge. Here, using a retrospective analysis of in-house historical data, we examined the parameters that impact the outcome of screening phage-displayed synthetic human sdAb libraries to discover antigen-specific binders. We found no evidence for a differential effect of domain type (V H or V L ), library randomization strategy, incorporation of a stabilizing disulfide linkage or sdAb display format (monovalent vs. multivalent) on the probability of obtaining any antigen-binding human sdAbs, instead finding that the success of library screens was primarily related to properties of target antigens, especially molecular mass. The solubility and binding affinity of sdAbs isolated from successful screens depended both on properties of the sdAb libraries (primarily domain type) and the target antigens. Taking attrition of sdAbs with major manufacturability concerns (aggregation; low expression) and sdAbs that do not recognize native cell-surface antigens as independent probabilities, we calculate the overall likelihood of obtaining ≥1 antigen-binding human sdAb from a single library-target screen as ~24%. Successful library-target screens should be expected to yield ~1.3 human sdAbs on average, each with average binding affinity of ~2 μM. Copyright © 2018 Elsevier B.V. All rights reserved.

Quantification of trace elements and speciation of iron in atmospheric particulate matter

NASA Astrophysics Data System (ADS)

Upadhyay, Nabin

Trace metal species play important roles in atmospheric redox processes and in the generation of oxidants in cloud systems. The chemical impact of these elements on atmospheric and cloud chemistry is dependent on their occurrence, solubility and speciation. First, analytical protocols have been developed to determine trace elements in particulate matter samples collected for carbonaceous analysis. The validated novel protocols were applied to the determination of trace elements in particulate samples collected in the remote marine atmosphere and urban areas in Arizona to study air pollution issues. The second part of this work investigates on solubility and speciation in environmental samples. A detailed study on the impact of the nature and strength of buffer solutions on solubility and speciation of iron lead to a robust protocol, allowing for comparative measurements in matrices representative of cloud water conditions. Application of this protocol to samples from different environments showed low iron solubility (less than 1%) in dust-impacted events and higher solubility (5%) in anthropogenically impacted urban samples. In most cases, Fe(II) was the dominant oxidation state in the soluble fraction of iron. The analytical protocol was then applied to investigate iron processing by fogs. Field observations showed that only a small fraction (1%) of iron was scavenged by fog droplets for which each of the soluble and insoluble fraction were similar. A coarse time resolution limited detailed insights into redox cycling within fog system. Overall results suggested that the major iron species in the droplets was Fe(1I) (80% of soluble iron). Finally, the occurrence and sources of emerging organic pollutants in the urban atmosphere were investigated. Synthetic musk species are ubiquitous in the urban environment (less than 5 ng m-3) and investigations at wastewater treatment plants showed that wastewater aeration basins emit a substantial amount of these species to the atmosphere.

Differential solubility of curcuminoids in serum and albumin solutions: implications for analytical and therapeutic applications

PubMed Central

Quitschke, Wolfgang W

2008-01-01

Background Commercially available curcumin preparations contain a mixture of related polyphenols, collectively referred to as curcuminoids. These encompass the primary component curcumin along with its co-purified derivatives demethoxycurcumin and bisdemethoxycurcumin. Curcuminoids have numerous biological activities, including inhibition of cancer related cell proliferation and reduction of amyloid plaque formation associated with Alzheimer disease. Unfortunately, the solubility of curcuminoids in aqueous solutions is exceedingly low. This restricts their systemic availability in orally administered formulations and limits their therapeutic potential. Results Methods are described that achieve high concentrations of soluble curcuminoids in serum. Solid curcuminoids were either mixed directly with serum, or they were predissolved in dimethyl sulfoxide and added as aliquots to serum. Both methods resulted in high levels of curcuminoid-solubility in mammalian sera from different species. However, adding aliquots of dimethyl sulfoxide-dissolved curcuminoids to serum proved to be more efficient, producing soluble curcuminoid concentrations of at least 3 mM in human serum. The methods also resulted in the differential solubility of individual curcuminoids in serum. The addition of dimethyl sulfoxide-dissolved curcuminoids to serum preferentially solubilized curcumin, whereas adding solid curcuminoids predominantly solubilized bisdemethoxycurcumin. Either method of solubilization was equally effective in inhibiting dose-dependent HeLa cell proliferation in culture. The maximum concentration of curcuminoids achieved in serum was at least 100-fold higher than that required for inhibiting cell proliferation in culture and 1000-fold higher than the concentration that has been reported to prevent amyloid plaque formation associated with Alzheimer disease. Curcuminoids were also highly soluble in solutions of purified albumin, a major component of serum. Conclusion These results suggest the possibility of alternative therapeutic approaches by injection or infusion of relatively small amounts of curcuminoid-enriched serum. They also provide tools to reproducibly solubilize curcuminoids for analysis in cell culture applications. The differential solubility of curcuminoids achieved by different methods of solubilization offers convenient alternatives to assess the diverse biological effects contributed by curcumin and its derivatives. PMID:18990234

Soluble organic carbon and pH of organic amendments affect metal mobility and chemical speciation in mine soils.

PubMed

Pérez-Esteban, Javier; Escolástico, Consuelo; Masaguer, Alberto; Vargas, Carmen; Moliner, Ana

2014-05-01

We evaluated the effects of pH and soluble organic carbon affected by organic amendments on metal mobility to find out the optimal conditions for their application in the stabilization of metals in mine soils. Soil samples (pH 5.5-6.2) were mixed with 0, 30 and 60 th a(-1) of sheep-horse manure (pH 9.4) and pine bark compost (pH 5.7). A single-step extraction procedure was performed using 0.005 M CaCl2 adjusted to pH 4.0-7.0 and metal speciation in soil solution was simulated using NICA-Donnan model. Sheep-horse manure reduced exchangeable metal concentrations (up to 71% Cu, 75% Zn) due to its high pH and degree of maturity, whereas pine bark increased them (32% Cu, 33% Zn). However, at increasing dose and hence pH, sheep-horse manure increased soluble Cu because of higher soluble organic carbon, whereas soluble Cu and organic carbon increased at increasing dose and correspondingly decreasing pH in pine bark and non-amended treatments. Near the native pH of these soils (at pH 5.8-6.3), with small doses of amendments, there was minimum soluble Cu and organic carbon. Pine bark also increased Zn solubility, whereas sheep-horse manure reduced it as soluble Zn always decreased with increasing pH. Sheep-horse manure also reduced the proportion of free metals in soil solution (from 41% to 4% Cu, from 97% to 94% Zn), which are considered to be more bioavailable than organic species. Sheep-horse manure amendment could be efficiently used for the stabilization of metals with low risk of leaching to groundwater at low doses and at relatively low pH, such as the native pH of mine soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identification of a Broad-Spectrum Antiviral Small Molecule against Severe Acute Respiratory Syndrome Coronavirus and Ebola, Hendra, and Nipah Viruses by Using a Novel High-Throughput Screening Assay

PubMed Central

Elshabrawy, Hatem A.; Fan, Jilao; Haddad, Christine S.; Ratia, Kiira; Broder, Christopher C.; Caffrey, Michael

2014-01-01

ABSTRACT Severe acute respiratory syndrome coronavirus (SARS-CoV) and Ebola, Hendra, and Nipah viruses are members of different viral families and are known causative agents of fatal viral diseases. These viruses depend on cathepsin L for entry into their target cells. The viral glycoproteins need to be primed by protease cleavage, rendering them active for fusion with the host cell membrane. In this study, we developed a novel high-throughput screening assay based on peptides, derived from the glycoproteins of the aforementioned viruses, which contain the cathepsin L cleavage site. We screened a library of 5,000 small molecules and discovered a small molecule that can inhibit the cathepsin L cleavage of all viral peptides with minimal inhibition of cleavage of a host protein-derived peptide (pro-neuropeptide Y). The small molecule inhibited the entry of all pseudotyped viruses in vitro and the cleavage of SARS-CoV spike glycoprotein in an in vitro cleavage assay. In addition, the Hendra and Nipah virus fusion glycoproteins were not cleaved in the presence of the small molecule in a cell-based cleavage assay. Furthermore, we demonstrate that the small molecule is a mixed inhibitor of cathepsin L. Our broad-spectrum antiviral small molecule appears to be an ideal candidate for future optimization and development into a potent antiviral against SARS-CoV and Ebola, Hendra, and Nipah viruses. IMPORTANCE We developed a novel high-throughput screening assay to identify small molecules that can prevent cathepsin L cleavage of viral glycoproteins derived from SARS-CoV and Ebola, Hendra, and Nipah viruses that are required for their entry into the host cell. We identified a novel broad-spectrum small molecule that could block cathepsin L-mediated cleavage and thus inhibit the entry of pseudotypes bearing the glycoprotein derived from SARS-CoV or Ebola, Hendra, or Nipah virus. The small molecule can be further optimized and developed into a potent broad-spectrum antiviral drug. PMID:24501399

Identification of a broad-spectrum antiviral small molecule against severe acute respiratory syndrome coronavirus and Ebola, Hendra, and Nipah viruses by using a novel high-throughput screening assay.

PubMed

Elshabrawy, Hatem A; Fan, Jilao; Haddad, Christine S; Ratia, Kiira; Broder, Christopher C; Caffrey, Michael; Prabhakar, Bellur S

2014-04-01

Severe acute respiratory syndrome coronavirus (SARS-CoV) and Ebola, Hendra, and Nipah viruses are members of different viral families and are known causative agents of fatal viral diseases. These viruses depend on cathepsin L for entry into their target cells. The viral glycoproteins need to be primed by protease cleavage, rendering them active for fusion with the host cell membrane. In this study, we developed a novel high-throughput screening assay based on peptides, derived from the glycoproteins of the aforementioned viruses, which contain the cathepsin L cleavage site. We screened a library of 5,000 small molecules and discovered a small molecule that can inhibit the cathepsin L cleavage of all viral peptides with minimal inhibition of cleavage of a host protein-derived peptide (pro-neuropeptide Y). The small molecule inhibited the entry of all pseudotyped viruses in vitro and the cleavage of SARS-CoV spike glycoprotein in an in vitro cleavage assay. In addition, the Hendra and Nipah virus fusion glycoproteins were not cleaved in the presence of the small molecule in a cell-based cleavage assay. Furthermore, we demonstrate that the small molecule is a mixed inhibitor of cathepsin L. Our broad-spectrum antiviral small molecule appears to be an ideal candidate for future optimization and development into a potent antiviral against SARS-CoV and Ebola, Hendra, and Nipah viruses. We developed a novel high-throughput screening assay to identify small molecules that can prevent cathepsin L cleavage of viral glycoproteins derived from SARS-CoV and Ebola, Hendra, and Nipah viruses that are required for their entry into the host cell. We identified a novel broad-spectrum small molecule that could block cathepsin L-mediated cleavage and thus inhibit the entry of pseudotypes bearing the glycoprotein derived from SARS-CoV or Ebola, Hendra, or Nipah virus. The small molecule can be further optimized and developed into a potent broad-spectrum antiviral drug.

Facile synthesis of water-soluble and biocompatible fluorescent nitrogen-doped carbon dots for cell imaging.

PubMed

Wang, Weiping; Lu, Ya-Chun; Huang, Hong; Feng, Jiu-Ju; Chen, Jian-Rong; Wang, Ai-Jun

2014-04-07

A simple, facile and green hydrothermal method was developed in the synthesis of water-soluble nitrogen-doped carbon dots (N-CDs) from streptomycin. The as-prepared N-CDs displayed bright blue fluorescence under the irradiation of UV light, together with a high quantum yield of 7.6% and good biocompatibility as demonstrated by the cell viability assay. Thus, the N-CDs can be used as fluorescent probes for cell imaging, which have potential applications in bioimaging and related fields. This strategy opens a new way for the preparation of fluorescent carbon nanomaterials using small molecules as carbon sources.

Soil organic matter composition affected by potato cropping managements

USDA-ARS?s Scientific Manuscript database

Organic matter is a small but important soil component. As a heterogeneous mixture of geomolecules and biomolecules, soil organic matter (SOM) can be fractionated into distinct pools with different solubility and lability. Water extractable organic matter (WEOM) fraction is the most labile and mobil...

Using aquatic vegetation to remediate nitrate, ammonium, and soluble reactive phosphorus in simulated runoff

USDA-ARS?s Scientific Manuscript database

Within the agriculturally-intensive Mississippi River Basin of the United States, significant conservation efforts have focused on management practices that reduce nutrient runoff into receiving aquatic ecosystems. Only a small fraction of those efforts have focused on phytoremediation techniques. ...

Enhancement of the reduction efficiency of soluble starch for platinum nanoparticles synthesis.

PubMed

Tongsakul, Duangta; Wongravee, Kanet; Thammacharoen, Chuchaat; Ekgasit, Sanong

2012-08-01

In this work, the efficiency of soluble starch as a reducing and a stabilizing agent in the synthesis of platinum nanoparticles under acidic-alkaline treatment is systematically studied. The degraded intermediates with reducing potential (i.e., small molecules containing aldehyde and α-hydroxy ketone moieties) are concomitantly generated when the alkaline concentration is greater than 0.025 M. The in situ generated species could completely reduce platinum ions (20 mM) and sufficiently stabilize the obtained platinum nanoparticles (5 mM) of uniform particle size (2-4 nm). The reduction is efficient and rapid as a complete conversion is achieved within 5 min. In a stronger alkaline condition, the platinum nanoparticles tend to aggregate and form a bigger domain because extensive degradation generates small starch fragments with less stabilization efficiency. This observation suggests that starch is a promising green material which could be chemically treated and transformed to a powerful reducing agent and stabilizer for the synthesis of metal nanoparticles. Copyright © 2012 Elsevier Ltd. All rights reserved.

Vitamine--vitamin. The early years of discovery.

PubMed

Rosenfeld, L

1997-04-01

In 1905, Cornelius Adrianus Pekelharing found that animals fed purified proteins, carbohydrates, fats, inorganic salts, and water would thrive only if small amounts of milk were added to the diet. He concluded that the milk contained some unrecognized substance that in very small quantities was necessary for normal growth and maintenance. In 1911, Casimir Funk isolated a concentrate from rice polishings that cured polyneuritis in pigeons. He named the concentrate "vitamine" because it appeared to be vital to life and because it was probably an amine. Although the concentrate and other "accessory food substances" were not amines, the name stuck, but the final "e" was dropped. In 1913 two groups discovered a "fat-soluble" accessory food substance. Initially believed to be a single vitamin, two separate factors were involved. One, effective against xerophthalmia, was named vitamin A; the other, effective against rickets, was named vitamin D. The factor that prevented scurvy was isolated in 1928. Known as "water-soluble C," it was renamed ascorbic acid.