Role of electrostatic interactions in the assembly of empty spherical viral capsids
NASA Astrophysics Data System (ADS)
Šiber, Antonio; Podgornik, Rudolf
2007-12-01
We examine the role of electrostatic interactions in the assembly of empty spherical viral capsids. The charges on the protein subunits that make the viral capsid mutually interact and are expected to yield electrostatic repulsion acting against the assembly of capsids. Thus, attractive protein-protein interactions of nonelectrostatic origin must act to enable the capsid formation. We investigate whether the interplay of repulsive electrostatic and attractive interactions between the protein subunits can result in the formation of spherical viral capsids of a preferred radius. For this to be the case, we find that the attractive interactions must depend on the angle between the neighboring protein subunits (i.e., on the mean curvature of the viral capsid) so that a particular angle(s) is (are) preferred energywise. Our results for the electrostatic contributions to energetics of viral capsids nicely correlate with recent experimental determinations of the energetics of protein-protein contacts in the hepatitis B virus [P. Ceres A. Zlotnick, Biochemistry 41, 11525 (2002)].
Zianor Azrina, Z A; Beg, M Dalour H; Rosli, M Y; Ramli, Ridzuan; Junadi, Norhafzan; Alam, A K M Moshiul
2017-04-15
Nanocrystalline cellulose (NCC) was isolated from oil palm empty fruit bunch pulp (EFBP) using ultrasound assisted acid hydrolysis. The obtained NCC was analysed using FESEM, XRD, FTIR, and TGA, and compared with raw empty fruit bunch fibre (REFB), empty fruit bunch pulp (EFBP), and treated empty fruit bunch pulp (TEFBP). Based on FESEM analysis, it was found that NCC has a spherical shaped after acid hydrolysis with the assistance of ultrasound. This situation was different compared to previous studies that obtained rod-like shaped of NCC. Furthermore, the crystallinity of NCC is higher compared to REFB and EFBP. According to thermal stability, the NCC obtained shows remarkable sign of high thermal stability compared to REFB and EFBP. Copyright © 2017 Elsevier Ltd. All rights reserved.
Evaluating Descent and Ascent Trajectories Near Non-Spherical Bodies
NASA Technical Reports Server (NTRS)
Werner, Robert A.
2010-01-01
Spacecraft landing on small bodies pass through regions where conventional gravitation formulations using exterior spherical harmonics are inaccurate. An investigation shows that a formulation using interior solid spherical harmonics might be satisfactory. Interior spherical harmonic expansions are usable inside an imaginary, empty sphere. For this application, such a sphere could be positioned in empty space above the intended landing site and rotating with the body. When the spacecraft is inside this sphere, the interior harmonic expansion would be used instead of the conventional, exterior harmonic expansion. Coefficients can be determined by a least-squares fit to gravitation measurements synthesized from conventional formulations. Due to their unfamiliarity, recurrences for interior, as well as exterior, expansions are derived. Hotine's technique for partial derivatives of exterior spherical harmonics is extended to interior harmonics.
Zhao, Yuan; Keating, Kenneth; Dolman, Carl; Thorpe, Robin
2008-05-01
Lentiviral vectors persist in the host and are therefore ideally suited for long-term gene therapy. To advance the use of lentiviral vectors in humans, improvement of their production, purification, and characterization has become increasingly important and challenging. In addition to cellular contaminants derived from packaging cells, empty particles without therapeutic function are the major impurities that compromise product safety and efficacy. Removal of empty particles is difficult because of their innate similarity in particle size and protein composition to the complete particles. We propose that comparison of the properties of lentiviral products with those of purposely expressed empty particles may reveal potential differences between empty and complete particles. For this, three forms of recombinant lentiviral samples, that is, recombinant vesicular stomatitis virus glycoprotein (VSV-G) proteins, empty particles (VSV-G/Empty), and complete particles (VSV-G/SIN-GFP) carrying viral RNA, were purified by size-exclusion chromatography (SEC). The SEC-purified samples were further analyzed by immunoblotting with six antibodies to examine viral and cellular proteins associated with the particles. This study has demonstrated, for the first time, important differences between VSV-G/Empty particles and complete VSV-G/SIN-GFP particles. Differences include the processing of Gag protein and the inclusion of cellular proteins in the particles. Our findings support the development of improved production, purification, and characterization methods for lentiviral products.
Synthetic approaches to construct viral capsid-like spherical nanomaterials.
Matsuura, Kazunori
2018-06-06
This feature article describes recent progress in synthetic strategies to construct viral capsid-like spherical nanomaterials using the self-assembly of peptides and/or proteins. By mimicking the self-assembly of spherical viral capsids and clathrin, trigonal peptide conjugates bearing β-sheet-forming peptides, glutathiones, or coiled-coil-forming peptides were developed to construct viral capsid-like particles. β-Annulus peptides from tomato bushy stunt virus self-assembled into viral capsid-like nanocapsules with a size of 30-50 nm, which could encapsulate various guest molecules and be decorated with different molecules on their surface. Rationally designed fusion proteins bearing symmetric assembling units afforded precise viral capsid-like polyhedral assemblies. These synthetic approaches to construct artificial viruses could become useful guidelines to develop novel drug carriers, vaccine platforms, nanotemplates and nanoreactors.
Ning, Xiaojun; Luckenbaugh, Laurie; Liu, Kuancheng; Bruss, Volker; Sureau, Camille; Hu, Jianming
2018-05-09
During the morphogenesis of hepatitis B virus (HBV), an enveloped virus, two types of virions are secreted: (1) a minor population of complete virions containing a mature nucleocapsid with the characteristic, partially double-stranded, relaxed circular DNA genome and (2) a major population containing an empty capsid with no DNA or RNA (empty virions). Secretion of both types of virions requires interactions between the HBV capsid or core protein (HBc) and the viral surface or envelope proteins. We have studied the requirements from both HBc and envelope proteins for empty virion secretion, in comparison with those for secretion of complete virions. Substitutions within the N-terminal domain of HBc that block secretion of DNA-containing virions reduced but did not prevent secretion of empty virions. The HBc C-terminal domain was not essential for empty virion secretion. Among the three viral envelope proteins, the smallest, S, alone was sufficient for empty virion secretion at a basal level. The largest protein, L, essential for complete virion secretion, was not required for, but could stimulate empty virion secretion. Also, substitutions in L that eliminate secretion of complete virions reduced but did not eliminate empty virion secretion. S mutations that block secretion of the hepatitis D virus (HDV), an HBV satellite, did not block secretion of either empty or complete HBV virions. Together, these results indicate that both common and distinct signals on empty capsids vs. mature nucleocapsids interact with the S and L proteins during the formation of complete vs. empty virions. IMPORTANCE Hepatitis B virus (HBV) is a major cause of severe liver diseases including cirrhosis and cancer. In addition to the complete infectious virion particle, which contains an outer envelope layer and an interior capsid that, in turn, encloses a DNA genome, HBV infected cells also secrete non-infectious, incomplete viral particles in large excess over the complete virions. In particular, the empty (or genome-free) virion share with the complete virion the outer envelope and interior capsid but contain no genome. We have carried out a comparative study on the capsid and envelope requirements for the secretion of these two types of virion particles and uncovered both shared and distinct determinants on the capsid and envelope for their secretion. These results provide new information on HBV morphogenesis, and have implications for efforts to develop empty HBV virions as a novel biomarker and a new generation of HBV vaccine. Copyright © 2018 American Society for Microbiology.
Formation of a cavitation cluster in the vicinity of a quasi-empty rupture
NASA Astrophysics Data System (ADS)
Bol'shakova, E. S.; Kedrinskiy, V. K.
2017-09-01
The presentation deals with one of the experimental and numerical models of a quasi-empty rupture in the magma melt. This rupture is formed in the liquid layer of a distilled cavitating fluid under shock loading within the framework of the problem formulation with a small electromagnetic hydrodynamic shock tube. It is demonstrated that the rupture is shaped as a spherical segment, which retains its topology during the entire process of its evolution and collapsing. The dynamic behavior of the quasi-empty rupture is analyzed, and the growth of cavitating nuclei in the form of the boundary layer near the entire rupture interface is found. It is shown that rupture implosion is accompanied by the transformation of the bubble boundary layer to a cavitating cluster, which takes the form of a ring-shaped vortex floating upward to the free surface of the liquid layer. A p-κ mathematical model is formulated, and calculations are performed to investigate the implosion of a quasi-empty spherical cavity in the cavitating liquid, generation of a shock wave by this cavity, and dynamics of the bubble density growth in the cavitating cluster by five orders of magnitude.
Classification of capped tubular viral particles in the family of Papovaviridae
NASA Astrophysics Data System (ADS)
Keef, T.; Taormina, A.; Twarock, R.
2006-04-01
A vital constituent of a virus is its protein shell, called the viral capsid, that encapsulates and hence provides protection for the viral genome. Viral capsids are usually spherical, and for a significant number of viruses they exhibit overall icosahedral symmetry. The corresponding surface lattices, that encode the locations of the capsid proteins and intersubunit bonds, can be modelled by viral tiling theory. It has been shown in vitro that under a variation of the experimental boundary conditions, such as the pH value and salt concentration, tubular particles may appear instead of, or in addition to, spherical ones. In order to develop models that describe the simultaneous assembly of both spherical and tubular variants, and hence study the possibility of triggering tubular malformations as a means of interference with the replication mechanism, viral tiling theory has to be extended to include tubular lattices with end caps. We focus here on the case of Papovaviridae, which play a distinguished role from the viral structural point of view as they correspond to all pentamer lattices, i.e. lattices formed from clusters of five protein subunits throughout. These results pave the way for a generalization of recently developed assembly models.
Complete and Incomplete Hepatitis B Virus Particles: Formation, Function, and Application.
Hu, Jianming; Liu, Kuancheng
2017-03-21
Hepatitis B virus (HBV) is a para-retrovirus or retroid virus that contains a double-stranded DNA genome and replicates this DNA via reverse transcription of a RNA pregenome. Viral reverse transcription takes place within a capsid upon packaging of the RNA and the viral reverse transcriptase. A major characteristic of HBV replication is the selection of capsids containing the double-stranded DNA, but not those containing the RNA or the single-stranded DNA replication intermediate, for envelopment during virion secretion. The complete HBV virion particles thus contain an outer envelope, studded with viral envelope proteins, that encloses the capsid, which, in turn, encapsidates the double-stranded DNA genome. Furthermore, HBV morphogenesis is characterized by the release of subviral particles that are several orders of magnitude more abundant than the complete virions. One class of subviral particles are the classical surface antigen particles (Australian antigen) that contain only the viral envelope proteins, whereas the more recently discovered genome-free (empty) virions contain both the envelope and capsid but no genome. In addition, recent evidence suggests that low levels of RNA-containing particles may be released, after all. We will summarize what is currently known about how the complete and incomplete HBV particles are assembled. We will discuss briefly the functions of the subviral particles, which remain largely unknown. Finally, we will explore the utility of the subviral particles, particularly, the potential of empty virions and putative RNA virions as diagnostic markers and the potential of empty virons as a vaccine candidate.
DOE Office of Scientific and Technical Information (OSTI.GOV)
DiMattia, Michael; Govindasamy, Lakshmanan; Levy, Hazel C.
2005-10-01
The production, purification, crystallization and preliminary crystallographic analysis of empty adeno-associated virus serotype 5 capsids are reported. Adeno-associated virus serotype 5 (AAV5) is under development for gene-therapy applications for the treatment of cystic fibrosis. To elucidate the structural features of AAV5 that control its enhanced transduction of the apical surface of airway epithelia compared with other AAV serotypes, X-ray crystallographic studies of the viral capsid have been initiated. The production, purification, crystallization and preliminary crystallographic analysis of empty AAV5 viral capsids are reported. The crystals diffract X-rays to beyond 3.2 Å resolution using synchrotron radiation and belong to the orthorhombicmore » space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 264.7, b = 447.9, c = 629.7 Å. There is one complete T = 1 viral capsid per asymmetric unit. The orientation and position of the viral capsid in the asymmetric unit have been determined by rotation and translation functions, respectively, and the AAV5 structure determination is in progress.« less
Components of Adenovirus Genome Packaging
Ahi, Yadvinder S.; Mittal, Suresh K.
2016-01-01
Adenoviruses (AdVs) are icosahedral viruses with double-stranded DNA (dsDNA) genomes. Genome packaging in AdV is thought to be similar to that seen in dsDNA containing icosahedral bacteriophages and herpesviruses. Specific recognition of the AdV genome is mediated by a packaging domain located close to the left end of the viral genome and is mediated by the viral packaging machinery. Our understanding of the role of various components of the viral packaging machinery in AdV genome packaging has greatly advanced in recent years. Characterization of empty capsids assembled in the absence of one or more components involved in packaging, identification of the unique vertex, and demonstration of the role of IVa2, the putative packaging ATPase, in genome packaging have provided compelling evidence that AdVs follow a sequential assembly pathway. This review provides a detailed discussion on the functions of the various viral and cellular factors involved in AdV genome packaging. We conclude by briefly discussing the roles of the empty capsids, assembly intermediates, scaffolding proteins, portal vertex and DNA encapsidating enzymes in AdV assembly and packaging. PMID:27721809
Cassetti, Maria Cristina; Merchlinsky, Michael; Wolffe, Elizabeth J.; Weisberg, Andrea S.; Moss, Bernard
1998-01-01
The vaccinia virus A32 open reading frame was predicted to encode a protein with a nucleoside triphosphate-binding motif and a mass of 34 kDa. To investigate the role of this protein, we constructed a mutant in which the original A32 gene was replaced by an inducible copy. The recombinant virus, vA32i, has a conditional lethal phenotype: infectious virus formation was dependent on isopropyl-β-d-thiogalactopyranoside (IPTG). Under nonpermissive conditions, the mutant synthesized early- and late-stage viral proteins, as well as viral DNA that was processed into unit-length genomes. Electron microscopy of cells infected in the absence of IPTG revealed normal-appearing crescents and immature virus particles but very few with nucleoids. Instead of brick-shaped mature particles with defined core structures, there were numerous electron-dense, spherical particles. Some of these spherical particles were wrapped with cisternal membranes, analogous to intracellular and extracellular enveloped virions. Mutant viral particles, purified by sucrose density gradient centrifugation, had low infectivity and transcriptional activity, and the majority were spherical and lacked DNA. Nevertheless, the particle preparation contained representative membrane proteins, cleaved and uncleaved core proteins, the viral RNA polymerase, the early transcription factor and several enzymes, suggesting that incorporation of these components is not strictly coupled to DNA packaging. PMID:9621036
Analytical approximations for the collapse of an empty spherical bubble.
Obreschkow, D; Bruderer, M; Farhat, M
2012-06-01
The Rayleigh equation 3/2R+RR+pρ(-1)=0 with initial conditions R(0)=R(0), R(0)=0 models the collapse of an empty spherical bubble of radius R(T) in an ideal, infinite liquid with far-field pressure p and density ρ. The solution for r≡R/R(0) as a function of time t≡T/T(c), where R(T(c))≡0, is independent of R(0), p, and ρ. While no closed-form expression for r(t) is known, we find that r(0)(t)=(1-t(2))(2/5) approximates r(t) with an error below 1%. A systematic development in orders of t(2) further yields the 0.001% approximation r(*)(t)=r(0)(t)[1-a(1)Li(2.21)(t(2))], where a(1)≈-0.01832099 is a constant and Li is the polylogarithm. The usefulness of these approximations is demonstrated by comparison to high-precision cavitation data obtained in microgravity.
Modeling Viral Capsid Assembly
2014-01-01
I present a review of the theoretical and computational methodologies that have been used to model the assembly of viral capsids. I discuss the capabilities and limitations of approaches ranging from equilibrium continuum theories to molecular dynamics simulations, and I give an overview of some of the important conclusions about virus assembly that have resulted from these modeling efforts. Topics include the assembly of empty viral shells, assembly around single-stranded nucleic acids to form viral particles, and assembly around synthetic polymers or charged nanoparticles for nanotechnology or biomedical applications. I present some examples in which modeling efforts have promoted experimental breakthroughs, as well as directions in which the connection between modeling and experiment can be strengthened. PMID:25663722
The interplay between mechanics and stability of viral cages
NASA Astrophysics Data System (ADS)
Hernando-Pérez, Mercedes; Pascual, Elena; Aznar, María; Ionel, Alina; Castón, José R.; Luque, Antoni; Carrascosa, José L.; Reguera, David; de Pablo, Pedro J.
2014-02-01
The stability and strength of viral nanoparticles are crucial to fulfill the functions required through the viral cycle as well as using capsids for biomedical and nanotechnological applications. The mechanical properties of viral shells obtained through Atomic Force Microscopy (AFM) and continuum elasticity theory, such as stiffness or Young's modulus, have been interpreted very often in terms of stability. However, viruses are normally subjected to chemical rather than to mechanical aggression. Thus, a correct interpretation of mechanics in terms of stability requires an adequate linkage between the ability of viral cages to support chemical and mechanical stresses. Here we study the mechanical fragility and chemical stability of bacteriophage T7 in two different maturation states: the early proheads and the final mature capsids. Using chemical stress experiments we show that proheads are less stable than final mature capsids. Still, both particles present similar anisotropic stiffness, indicating that a continuum elasticity description in terms of Young's modulus is not an adequate measure of viral stability. In combination with a computational coarse-grained model we demonstrate that mechanical anisotropy of T7 emerges out of the discrete nature of the proheads and empty capsids. Even though they present the same stiffness, proheads break earlier and have fractures ten times larger than mature capsids, in agreement with chemical stability, thus demonstrating that fragility rather than stiffness is a better indicator of viral cages' stability.The stability and strength of viral nanoparticles are crucial to fulfill the functions required through the viral cycle as well as using capsids for biomedical and nanotechnological applications. The mechanical properties of viral shells obtained through Atomic Force Microscopy (AFM) and continuum elasticity theory, such as stiffness or Young's modulus, have been interpreted very often in terms of stability. However, viruses are normally subjected to chemical rather than to mechanical aggression. Thus, a correct interpretation of mechanics in terms of stability requires an adequate linkage between the ability of viral cages to support chemical and mechanical stresses. Here we study the mechanical fragility and chemical stability of bacteriophage T7 in two different maturation states: the early proheads and the final mature capsids. Using chemical stress experiments we show that proheads are less stable than final mature capsids. Still, both particles present similar anisotropic stiffness, indicating that a continuum elasticity description in terms of Young's modulus is not an adequate measure of viral stability. In combination with a computational coarse-grained model we demonstrate that mechanical anisotropy of T7 emerges out of the discrete nature of the proheads and empty capsids. Even though they present the same stiffness, proheads break earlier and have fractures ten times larger than mature capsids, in agreement with chemical stability, thus demonstrating that fragility rather than stiffness is a better indicator of viral cages' stability. Electronic supplementary information (ESI) available: Purification of T7 proheads and capsids, coarse-grained simulations of the indentation of T7 empty capsids, Finite Element (FE) simulations, and justification of the anisotropic stiffness based on structural information. See DOI: 10.1039/c3nr05763a
Michel, J. P.; Ivanovska, I. L.; Gibbons, M. M.; Klug, W. S.; Knobler, C. M.; Wuite, G. J. L.; Schmidt, C. F.
2006-01-01
The elastic properties of capsids of the cowpea chlorotic mottle virus have been examined at pH 4.8 by nanoindentation measurements with an atomic force microscope. Studies have been carried out on WT capsids, both empty and containing the RNA genome, and on full capsids of a salt-stable mutant and empty capsids of the subE mutant. Full capsids resisted indentation more than empty capsids, but all of the capsids were highly elastic. There was an initial reversible linear regime that persisted up to indentations varying between 20% and 30% of the diameter and applied forces of 0.6–1.0 nN; it was followed by a steep drop in force that is associated with irreversible deformation. A single point mutation in the capsid protein increased the capsid stiffness. The experiments are compared with calculations by finite element analysis of the deformation of a homogeneous elastic thick shell. These calculations capture the features of the reversible indentation region and allow Young's moduli and relative strengths to be estimated for the empty capsids. PMID:16606825
Shayakhmetov, D; Kovalenko, D; Yurov, G; Borisenko, A; Tikchonenko, T
1997-08-01
Use of viral inducible promoters which can be activated by virus-specific transactivator proteins to drive expression of antisense (as)RNA genes appears to be an attractive approach to inhibit virus infections in vivo. To this end, we have constructed an asRNA gene expressed from the bovine leukaemia virus (BLV) U3 promoter that is complementary to the R-U5 region of the BLV genome. This is the region that is most susceptible to inhibition by asRNA. With plasmid pLU, which expresses the asRNA gene under the control of the BLV U3 promoter, 75% inhibition of virus replication was attained in CC81 cells (the molar ratio of pLU DNA over BLV proviral DNA in the transfection mixture was 5:1). Plasmid pLT, which contains only the BLV U3 promoter without any asRNA-coding region, also efficiently (up to 60%) inhibited virus replication when cotransfected with BLV proviral DNA at a ratio of 20:1. It was suggested that competition between functional and 'empty' viral promoters for the viral transactivator protein p38tax could account for this inhibition. An immunoblotting assay showed that in the presence of nuclear extracts from CC81 cells exogenous BLV p38tax specifically associates with its responsive sequence located in the BLV U3 promoter. Moreover, the additional expression of p38tax in CC81 cells abolishes the inhibitory effect of the empty viral promoter. These observations suggest a new mechanism of BLV inhibition caused, most probably, by sequestering of the viral transactivator protein.
Applied potential tomography. A new noninvasive technique for measuring gastric emptying
DOE Office of Scientific and Technical Information (OSTI.GOV)
Avill, R.; Mangnall, Y.F.; Bird, N.C.
1987-04-01
Applied potential tomography is a new, noninvasive technique that yields sequential images of the resistivity of gastric contents after subjects have ingested a liquid or semisolid meal. This study validates the technique as a means of measuring gastric emptying. Experiments in vitro showed an excellent correlation between measurements of resistivity and either the square of the radius of a glass rod or the volume of water in a spherical balloon when both were placed in an oval tank containing saline. Altering the lateral position of the rod in the tank did not alter the values obtained. Images of abdominal resistivitymore » were also directly correlated with the volume of air in a gastric balloon. Profiles of gastric emptying of liquid meals obtained using applied potential tomography were very similar to those obtained using scintigraphy or dye dilution techniques, provided that acid secretion was inhibited by cimetidine. Profiles of emptying of a mashed potato meal using applied potential tomography were also very similar to those obtained by scintigraphy. Measurements of the emptying of a liquid meal from the stomach were reproducible if acid secretion was inhibited by cimetidine. Thus, applied potential tomography is an accurate and reproducible method of measuring gastric emptying of liquids and particulate food. It is inexpensive, well tolerated, easy to use, and ideally suited for multiple studies in patients, even those who are pregnant.« less
NASA Astrophysics Data System (ADS)
Michel, J. P.; Ivanovska, I. L.; Gibbons, M. M.; Klug, W. S.; Knobler, C. M.; Wuite, G. J. L.; Schmidt, C. F.
2006-04-01
The elastic properties of capsids of the cowpea chlorotic mottle virus have been examined at pH 4.8 by nanoindentation measurements with an atomic force microscope. Studies have been carried out on WT capsids, both empty and containing the RNA genome, and on full capsids of a salt-stable mutant and empty capsids of the subE mutant. Full capsids resisted indentation more than empty capsids, but all of the capsids were highly elastic. There was an initial reversible linear regime that persisted up to indentations varying between 20% and 30% of the diameter and applied forces of 0.6-1.0 nN; it was followed by a steep drop in force that is associated with irreversible deformation. A single point mutation in the capsid protein increased the capsid stiffness. The experiments are compared with calculations by finite element analysis of the deformation of a homogeneous elastic thick shell. These calculations capture the features of the reversible indentation region and allow Young's moduli and relative strengths to be estimated for the empty capsids. atomic force microscopy | cowpea chlorotic mottle virus | finite element analysis | biomechanics
Elastic properties and mechanical stability of chiral and filled viral capsids
NASA Astrophysics Data System (ADS)
Buenemann, Mathias; Lenz, Peter
2008-11-01
The elasticity and mechanical stability of empty and filled viral capsids under external force loading are studied in a combined analytical and numerical approach. We analyze the influence of capsid structure and chirality on the mechanical properties. We find that generally skew shells have lower stretching energy. For large Föppl-von Kármán numbers γ (γ≈105) , skew structures are stiffer in their elastic response than nonchiral ones. The discrete structure of the capsules not only leads to buckling for large γ but also influences the breakage behavior of capsules below the buckling threshold: the rupture force shows a γ1/4 scaling rather than a γ1/2 scaling as expected from our analytical results for continuous shells. Filled viral capsids are exposed to internal anisotropic pressure distributions arising from regularly packaged DNA coils. We analyze their influence on the elastic properties and rupture behavior and we discuss possible experimental consequences. Finally, we numerically investigate specific sets of parameters corresponding to specific phages such as ϕ29 and cowpea chlorotic mottle virus (CCMV). From the experimentally measured spring constants we make predictions about specific material parameters (such as bending rigidity and Young’s modulus) for both empty and filled capsids.
Shape transformation of viral capsids and HIV
NASA Astrophysics Data System (ADS)
Nguyen, Toan
2005-03-01
We present a continuum description of the shape transformation of viral capsids. The cone-like HIV virus is shown to be an thermodynamic stable shape, intermediate between icosahedral and sphero-cylinder capsid shapes. A generalized Caspar-Klug classification is introduced to describe spherical, conical and cylinderical shapes of virus.
Mignaqui, Ana Clara; Ruiz, Vanesa; Perret, Sylvie; St-Laurent, Gilles; Singh Chahal, Parminder; Transfiguracion, Julia; Sammarruco, Ayelén; Gnazzo, Victoria; Durocher, Yves; Wigdorovitz, Andrés
2013-01-01
Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. It produces severe economic losses in the livestock industry. Currently available vaccines are based on inactivated FMD virus (FMDV). The use of empty capsids as a subunit vaccine has been reported to be a promising candidate because it avoids the use of virus in the vaccine production and conserves the conformational epitopes of the virus. In this report, we explored transient gene expression (TGE) in serum-free suspension-growing mammalian cells for the production of FMDV recombinant empty capsids as a subunit vaccine. The recombinant proteins produced, assembled into empty capsids and induced protective immune response against viral challenge in mice. Furthermore, they were recognized by anti-FMDV bovine sera. By using this technology, we were able to achieve expression levels that are compatible with the development of a vaccine. Thus, TGE of mammalian cells is an easy to perform, scalable and cost-effective technology for the production of a recombinant subunit vaccine against FMDV.
Mechanisms of Size Control and Polymorphism in Viral Capsid Assembly
Elrad, Oren M.; Hagan, Michael F.
2009-01-01
We simulate the assembly dynamics of icosahedral capsids from subunits that interconvert between different conformations (or quasi-equivalent states). The simulations identify mechanisms by which subunits form empty capsids with only one morphology, but adaptively assemble into different icosahedral morphologies around nanoparticle cargoes with varying sizes, as seen in recent experiments with brome mosaic virus (BMV) capsid proteins. Adaptive cargo encapsidation requires moderate cargo-subunit interaction strengths; stronger interactions frustrate assembly by stabilizing intermediates with incommensurate curvature. We compare simulation results to experiments with cowpea chlorotic mottle virus empty capsids and BMV capsids assembled on functionalized nanoparticles, and suggest new cargo encapsidation experiments. Finally, we find that both empty and templated capsids maintain the precise spatial ordering of subunit conformations seen in the crystal structure even if interactions that preserve this arrangement are favored by as little as the thermal energy, consistent with experimental observations that different subunit conformations are highly similar. PMID:18950240
Role of LA Shape in Predicting Embolic Cerebrovascular Events in Mitral Stenosis
Nunes, Maria Carmo P.; Handschumacher, Mark D.; Levine, Robert A.; Barbosa, Marcia M.; Carvalho, Vinicius T.; Esteves, William A.; Zeng, Xin; Guerrero, J. Luis; Zheng, Hui; Tan, Timothy C.; Hung, Judy
2015-01-01
OBJECTIVES This study was designed to assess the role of left atrial (LA) shape in predicting embolic cerebrovascular events (ECE) in patients with mitral stenosis (MS). BACKGROUND Patients with rheumatic MS are at increased risk for ECE. LA remodeling in response to MS involves not only chamber dilation but also changes in the shape. We hypothesized that a more spherical LA shape may be associated with increased embolic events due to predisposition to thrombus formation or to atrial arrhythmias compared with an elliptical-shaped LA of comparable volume. METHODS A total of 212 patients with MS and 20 control subjects were enrolled. LA volume, LA emptying fraction, and cross-sectional area were measured by 3-dimensional (3D) transthoracic echocardiography. LA shape was expressed as the ratio of measured LA end-systolic volume to hypothetical sphere volume ([4/3π r3] where r was obtained from 3D cross-sectional area). The lower the LA shape index, the more spherical the shape. RESULTS A total of 41 patients presented with ECE at the time of enrollment or during follow-up. On multivariate analysis, LA 3D emptying fraction (adjusted odds ratio [OR]: 0.96; 95% confidence interval [CI]: 0.92 to 0.99; p = 0.028) and LA shape index (OR: 0.73; 95% CI: 0.61 to 0.87; p < 0.001) emerged as important factors associated with ECE, after adjustment for age and anticoagulation therapy. In patients in sinus rhythm, LA shape index remained associated with ECE (OR: 0.79; 95% CI: 0.67 to 0.94; p = 0.007), independent of age and LA function. An in vitro phantom atrial model demonstrated more stagnant flow profiles in spherical compared with ellipsoidal chamber. CONCLUSIONS In rheumatic MS patients, differential LA remodeling affects ECE risk. A more spherical LA shape was independently associated with an increased risk for ECE, adding incremental value in predicting events beyond that provided by age and LA function. PMID:24831206
Cotmore, S F; D'abramo, A M; Ticknor, C M; Tattersall, P
1999-02-01
Antisera were raised against peptides corresponding to the N-termini of capsid proteins VP1 and VP2 from the parvovirus minute virus of mice. Epitopes in the 142-amino-acid VP1-specific region were not accessible in the great majority of newly released viral particles, and sera directed against them failed to neutralize virus directly or deplete stocks of infectious virions. However, brief exposure to temperatures of 45 degreesC or more induced a conformational transition in a population of full virions, but not in empty viral particles, in which VP1-specific sequences became externally accessible. In contrast, the VP2 N-terminus was antibody-accessible in all full, but not empty, particles without prior treatment. An electrophoretic mobility shift assay, in which particles were heat-treated and/or preincubated with antibodies prior to electrophoresis, confirmed this pattern of epitope accessibility, showing that the heat-induced conformational transition produces a retarded form of virion that can be supershifted by incubation with VP1-specific sera. The proportion of virions undergoing transition increased with temperature, but at all temperatures up to 70 degreesC viral particles retained structure-specific antigenic determinants and remained essentially intact, without shedding individual polypeptide species or subunits. However, despite the apparent integrity of its protective coat, the genome became accessible to externally applied enzymes in an increasing proportion of virions through this temperature range, suggesting that the conformational transitions that expose VP1 likely also allow access to the genome. Heating particles to 80 degreesC or above finally induced disassembly to polypeptide monomers. Copyright 1999 Academic Press.
Localized Tissue Surrogate Deformation due to Controlled Single Bubble Cavitation
2014-08-27
calculate liquid jet formation with collapse of an empty spherical bubble due to the high surrounding fluid pressure 18. Experimental evidence of...maximum collapse pressures over a wide range between 8 MPa 13 to 2.5 GPa 11 have also been calculated . 5 A fundamental problem in the study of...and a digital image correlation (DIC) technique was used to calculate strain fields during bubble growth and collapse. The subsequent response of the
2017-04-01
concentration was adjusted so that each rat received 100 µl per 100 gram of its weight. Saline was injected at the same times and at the same proportional...left lung was fixed following inflation and stained with H&E for histological study. A. Vehicle only control; B. Vehicle-treated and 2CLP-operated
Simulations of curved assemblies in soft matter and biological systems
NASA Astrophysics Data System (ADS)
Qiao, Cong
Viruses are small infectious agents that replicate only inside living cells of other organisms. In the viral life cycle, the self-assembly of the outer protein shell (capsid) is an essential step. We study this process in the hope of shedding light on development of antiviral drugs, gene therapy and other virus-related technologies that can benefit the humankind. More fundamentally, learning about the process of viral capsid assembly can elucidate the assembly mechanisms of a wide range of complex structures. In this work, we use molecular dynamics simulations and coarse-grained computational models to study viral capsid assembly in several situations where geometric constraints play a role in dictating assembly outcomes. We first focus on icosahedral viruses with single-stranded RNA genomes, in which case the capsid usually assembles around the genomic RNA. It is consistently observed in experiments that such viral particles are ''overcharged'', meaning the net negative charge on the viral genome is greater than the net positive charge on the viral capsid. We computationally investigate the mechanisms that lead to ``overcharging'', and more broadly, how the encapsidated genome length is influenced by the capsid. We perform both dynamical simulations of the assembly process and equilibrium calculations to determine the optimal genome length (meaning that which maximizes the assembly yield and/or minimizes the free energy of the assembled virus). We find that the optimal genome length is determined by the interplay between capsid size, net capsid charge, distribution of capsid charge and nucleic acid structures. Our simulations demonstrate that overcharging results from a combination of electrostatic screening and the geometric constraints associated with encapsulating a nucleic acid inside of a spherical virus. We then study the assembly of the immature HIV. In contrast to icosahedral viruses, the immature HIV forms an asymmetric particle, consisting of continuous regularly packed regions with local hexagonal order and vacancies. A similar lattice structure has been observed in experiments in which mutually attractive colloidal particles pack on the surface of a spherical droplet (G. Meng, J. Paulose, D. R. Nelson, and V. N. Manoharan, ''Elastic instability of a crystal growing on a curved surface'', Science 343, 634-637 (2014).), suggesting that the two systems experience a similar form of geometric frustration. We therefore study the adsorption and packing of spherical particles on a spherical template, as a function of the strength and range of interparticle attractions, as well as the radius of the spherical template. We observe that the adsorbed particles form two different classes of packing arrangements, one with icosahedrally ordered topological defects, and the other with highly disordered defects and vacancies. The latter regime is consistent with experiments on colloidal packing on spherical droplets and the immature HIV lattice. Our results suggest that the transition between these regimes is controlled by the range of the interparticle attractions. In the last chapter, we study a model for the assembly and budding of a capsid on a membrane, such as occurs during the exit of the immature HIV virus from a cell. We use a coarse-grained subunit model to represent the capsid proteins, and a fluid membrane model to represent the cell membrane. We find that the size and structure of the assembled capsid depends sensitively on the timescale of budding.
DOE Office of Scientific and Technical Information (OSTI.GOV)
DiMattia,M.; Govindasamy, L.; Levy, H.
2005-01-01
Adeno-associated virus serotype 5 (AAV5) is under development for gene-therapy applications for the treatment of cystic fibrosis. To elucidate the structural features of AAV5 that control its enhanced transduction of the apical surface of airway epithelia compared with other AAV serotypes, X-ray crystallographic studies of the viral capsid have been initiated. The production, purification, crystallization and preliminary crystallographic analysis of empty AAV5 viral capsids are reported. The crystals diffract X-rays to beyond 3.2 Angstroms resolution using synchrotron radiation and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 264.7, b = 447.9, c =more » 629.7 Angstroms. There is one complete T = 1 viral capsid per asymmetric unit. The orientation and position of the viral capsid in the asymmetric unit have been determined by rotation and translation functions, respectively, and the AAV5 structure determination is in progress.« less
Cryo-Electron Microscopy of Viruses Infecting Bacterium
NASA Astrophysics Data System (ADS)
Chiu, Wah
2010-03-01
Single particle cryo-EM can yield structures of infectious bacterial viruses with and without imposed icosahedral symmetry at subnanometer resolution. Reconstructions of infectious and empty phage particles show substantial differences in the portal vertex protein complex at one of the 12 pentameric vertices in the icosahedral virus particle through which the viral genomes are packaged or released. In addition, electron cryo-tomography of viruses during infecting its bacterial host cell displayed multiple conformations of the tail fiber of the virus. Our structural observations by single particle and tomographic reconstructions suggest a mechanism whereby the viral tail fibers, upon binding to the host cell, induce a cascade of structural alterations of the portal vertex protein complex that triggers DNA release.
Hepatitis B Virus Core Protein Dephosphorylation Occurs during Pregenomic RNA Encapsidation.
Zhao, Qiong; Hu, Zhanying; Cheng, Junjun; Wu, Shuo; Luo, Yue; Chang, Jinhong; Hu, Jianming; Guo, Ju-Tao
2018-07-01
Hepatitis B virus (HBV) core protein consists of an N-terminal assembly domain and a C-terminal domain (CTD) with seven conserved serines or threonines that are dynamically phosphorylated/dephosphorylated during the viral replication cycle. Sulfamoylbenzamide derivatives are small molecular core protein allosteric modulators (CpAMs) that bind to the heteroaryldihydropyrimidine (HAP) pocket between the core protein dimer-dimer interfaces. CpAM binding alters the kinetics and pathway of capsid assembly and can result in the formation of morphologically "normal" capsids devoid of viral pregenomic RNA (pgRNA) and DNA polymerase. In order to investigate the mechanism underlying CpAM inhibition of pgRNA encapsidation, we developed an immunoblotting assay that can resolve core protein based on its phosphorylation status and demonstrated, for the first time, that core protein is hyperphosphorylated in free dimers and empty capsids from both mock-treated and CpAM-treated cells but is hypophosphorylated in pgRNA- and DNA-containing nucleocapsids. Interestingly, inhibition of pgRNA encapsidation by a heat shock protein 90 (HSP90) inhibitor prevented core protein dephosphorylation. Moreover, core proteins with point mutations at the wall of the HAP pocket, V124A and V124W, assembled empty capsids and nucleocapsids with altered phosphorylation status. The results thus suggest that core protein dephosphorylation occurs in the assembly of pgRNA and that interference with the interaction between core protein subunits at dimer-dimer interfaces during nucleocapsid assembly alters not only capsid structure, but also core protein dephosphorylation. Hence, inhibition of pgRNA encapsidation by CpAMs might be due to disruption of core protein dephosphorylation during nucleocapsid assembly. IMPORTANCE Dynamic phosphorylation of HBV core protein regulates multiple steps of viral replication. However, the regulatory function was mainly investigated by phosphomimetic mutagenesis, which disrupts the natural dynamics of core protein phosphorylation/dephosphorylation. Development of an immunoblotting assay capable of resolving hyper- and hypophosphorylated core proteins allowed us to track the phosphorylation status of core proteins existing as free dimers and the variety of intracellular capsids and to investigate the role of core protein phosphorylation/dephosphorylation in viral replication. Here, we found that disruption of core protein interaction at dimer-dimer interfaces during nucleocapsid assembly (by CpAMs or mutagenesis) inhibited core protein dephosphorylation and pgRNA packaging. Our work has thus revealed a novel function of core protein dephosphorylation in HBV replication and the mechanism by which CpAMs, a class of compounds that are currently in clinical trials for treatment of chronic hepatitis B, induce the assembly of empty capsids. Copyright © 2018 American Society for Microbiology.
Basavappa, R.; Syed, R.; Flore, O.; Icenogle, J. P.; Filman, D. J.; Hogle, J. M.
1994-01-01
The crystal structure of the P1/Mahoney poliovirus empty capsid has been determined at 2.9 A resolution. The empty capsids differ from mature virions in that they lack the viral RNA and have yet to undergo a stabilizing maturation cleavage of VP0 to yield the mature capsid proteins VP4 and VP2. The outer surface and the bulk of the protein shell are very similar to those of the mature virion. The major differences between the 2 structures are focused in a network formed by the N-terminal extensions of the capsid proteins on the inner surface of the shell. In the empty capsids, the entire N-terminal extension of VP1, as well as portions corresponding to VP4 and the N-terminal extension of VP2, are disordered, and many stabilizing interactions that are present in the mature virion are missing. In the empty capsid, the VP0 scissile bond is located some 20 A away from the positions in the mature virion of the termini generated by VP0 cleavage. The scissile bond is located on the rim of a trefoil-shaped depression in the inner surface of the shell that is highly reminiscent of an RNA binding site in bean pod mottle virus. The structure suggests plausible (and ultimately testable) models for the initiation of encapsidation, for the RNA-dependent autocatalytic cleavage of VP0, and for the role of the cleavage in establishing the ordered N-terminal network and in generating stable virions. PMID:7849583
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lamb, Kristen; Lokesh, G.L.; Sherman, Michael
2010-10-25
Venezuelan equine encephalitis virus (VEEV) is a prototypical enveloped ssRNA virus of the family Togaviridae. To better understand alphavirus assembly, we analyzed newly formed nucleocapsid particles (termed pre-viral nucleocapsids) isolated from infected cells. These particles were intermediates along the virus assembly pathway, and ultimately bind membrane-associated viral glycoproteins to bud as mature infectious virus. Purified pre-viral nucleocapsids were spherical with a unimodal diameter distribution. The structure of one class of pre-viral nucleocapsids was determined with single particle reconstruction of cryo-electron microscopy images. These studies showed that pre-viral nucleocapsids assembled into an icosahedral structure with a capsid stoichiometry similar to themore » mature nucleocapsid. However, the individual capsomers were organized significantly differently within the pre-viral and mature nucleocapsids. The pre-viral nucleocapsid structure implies that nucleocapsids are highly plastic and undergo glycoprotein and/or lipid-driven rearrangements during virus self-assembly. This mechanism of self-assembly may be general for other enveloped viruses.« less
The vaccinia virus E6 protein influences virion protein localization during virus assembly
DOE Office of Scientific and Technical Information (OSTI.GOV)
Condit, Richard C., E-mail: condit@mgm.ufl.edu; Moussatche, Nissin
2015-08-15
Vaccinia virus mutants in which expression of the virion core protein gene E6R is repressed are defective in virion morphogenesis. E6 deficient infections fail to properly package viroplasm into viral membranes, resulting in an accumulation of empty immature virions and large aggregates of viroplasm. We have used immunogold electron microscopy and immunofluorescence confocal microscopy to assess the intracellular localization of several virion structural proteins and enzymes during E6R mutant infections. We find that during E6R mutant infections virion membrane proteins and virion transcription enzymes maintain a normal localization within viral factories while several major core and lateral body proteins accumulatemore » in aggregated virosomes. The results support a model in which vaccinia virions are assembled from at least three substructures, the membrane, the viroplasm and a “pre-nucleocapsid”, and that the E6 protein is essential for maintaining proper localization of the seven-protein complex and the viroplasm during assembly. - Highlights: • Mutation of E6 disrupts association of viral membranes with viral core proteins • Mutation of E6 does not perturb viral membrane biosynthesis • Mutation of E6 does not perturb localization of viral transcription enzymes • Mutation of E6 causes mis-localization and aggregation of viral core proteins • Vaccinia assembly uses three subassemblies: membranes, viroplasm, prenucleocapsid.« less
Häring, Monika; Peng, Xu; Brügger, Kim; Rachel, Reinhard; Stetter, Karl O; Garrett, Roger A; Prangishvili, David
2004-06-01
A novel virus, termed Pyrobaculum spherical virus (PSV), is described that infects anaerobic hyperthermophilic archaea of the genera Pyrobaculum and Thermoproteus. Spherical enveloped virions, about 100 nm in diameter, contain a major multimeric 33-kDa protein and host-derived lipids. A viral envelope encases a superhelical nucleoprotein core containing linear double-stranded DNA. The PSV infection cycle does not cause lysis of host cells. The viral genome was sequenced and contains 28337 bp. The genome is unique for known archaeal viruses in that none of the genes, including that encoding the major structural protein, show any significant sequence matches to genes in public sequence databases. Exceptionally for an archaeal double-stranded DNA virus, almost all the recognizable genes are located on one DNA strand. The ends of the genome consist of 190-bp inverted repeats that contain multiple copies of short direct repeats. The two DNA strands are probably covalently linked at their termini. On the basis of the unusual morphological and genomic properties of this DNA virus, we propose to assign PSV to a new viral family, the Globuloviridae.
Kohlbrenner, Erik; Henckaerts, Els; Rapti, Kleopatra; Gordon, Ronald E; Linden, R Michael; Hajjar, Roger J; Weber, Thomas
2012-06-01
Adeno-associated virus (AAV)-based vectors have gained increasing attention as gene delivery vehicles in basic and preclinical studies as well as in human gene therapy trials. Especially for the latter two-for both safety and therapeutic efficacy reasons-a detailed characterization of all relevant parameters of the vector preparation is essential. Two important parameters that are routinely used to analyze recombinant AAV vectors are (1) the titer of viral particles containing a (recombinant) viral genome and (2) the purity of the vector preparation, most commonly assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by silver staining. An important, third parameter, the titer of total viral particles, that is, the combined titer of both genome-containing and empty viral capsids, is rarely determined. Here, we describe a simple and inexpensive method that allows the simultaneous assessment of both vector purity and the determination of the total viral particle titer. This method, which was validated by comparison with established methods to determine viral particle titers, is based on the fact that Coomassie Brilliant Blue, when bound to proteins, fluoresces in the infrared spectrum. Viral samples are separated by SDS-PAGE followed by Coomassie Brilliant Blue staining and gel analysis with an infrared laser-scanning device. In combination with a protein standard, our method allows the rapid and accurate determination of viral particle titers simultaneously with the assessment of vector purity.
Empty Turnip yellow mosaic virus capsids as delivery vehicles to mammalian cells.
Kim, Doyeong; Lee, Younghee; Dreher, Theo W; Cho, Tae-Ju
2018-05-03
Turnip yellow mosaic virus (TYMV) was able to enter animal cells when the spherical plant virus was conjugated with Tat, a cell penetrating peptide (CPP). Tat was chemically attached to the surface lysine residues of TYMV using hydrazone chemistry. Baby hamster kidney (BHK) cells were incubated with either unmodified or Tat-conjugated TYMV and examined by flow cytometry and confocal microscopic analyses. Tat conjugation was shown to be more efficient than Lipofectamine in allowing TYMV to enter the mammalian cells. Tat-assisted-transfection was also associated with less loss of cell viability than lipofection. Among the CPPs tested (Tat, R8, Pep-1 and Pen), it was observed that R8 and Pen were also effective while Pep-1 was not. We also examined if the internal space of TYMV can be used to load fluorescein dye as a model cargo. When TYMV is treated by freezing and thawing, the virus is known to convert into a structure with a 6-8 nm hole and release viral RNA. When the resultant pot-like particles were reacted with fluorescein-5-maleimide using interior sulfhydryl groups as conjugation sites, about 145 fluorescein molecules were added per particle. The fluorescein-loaded TYMV particles were conjugated with Tat and introduced into BHK cells, again with higher transfection efficiency compared to lipofection. Our studies demonstrate the potential of modified TYMV as an efficient system for therapeutic cargo delivery to mammalian cells. Copyright © 2018 Elsevier B.V. All rights reserved.
Capture and alignment of phi29 viral particles in sub-40 nanometer porous alumina membranes.
Moon, Jeong-Mi; Akin, Demir; Xuan, Yi; Ye, Peide D; Guo, Peixuan; Bashir, Rashid
2009-02-01
Bacteriophage phi29 virus nanoparticles and its associated DNA packaging nanomotor can provide for novel possibilities towards the development of hybrid bio-nano structures. Towards the goal of interfacing the phi29 viruses and nanomotors with artificial micro and nanostructures, we fabricated nanoporous Anodic Aluminum Oxide (AAO) membranes with pore size of 70 nm and shrunk the pores to sub 40 nm diameter using atomic layer deposition (ALD) of Aluminum Oxide. We were able to capture and align particles in the anodized nanopores using two methods. Firstly, a functionalization and polishing process to chemically attach the particles in the inner surface of the pores was developed. Secondly, centrifugation of the particles was utilized to align them in the pores of the nanoporous membranes. In addition, when a mixture of empty capsids and packaged particles was centrifuged at specific speeds, it was found that the empty capsids deform and pass through 40 nm diameter pores whereas the particles packaged with DNA were mainly retained at the top surface of the nanoporous membranes. Fluorescence microscopy was used to verify the selective filtration of empty capsids through the nanoporous membranes.
Generalized transformations and coordinates for static spherically symmetric general relativity
NASA Astrophysics Data System (ADS)
Hill, James M.; O'Leary, Joseph
2018-04-01
We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.
Acoustically excited surface waves on empty or fluid-filled cylindrical and spherical shells
NASA Astrophysics Data System (ADS)
Ahyi, A. Claude; Cao, H.; Raju, P. K.; Werby, M. F.; Bao, X. L.; Überall, H.
2002-05-01
A comparative study is presented of the acoustical excitation of circumferential (surface) waves on fluid-immersed cylindrical or spherical metal shells, which may be either evacuated, or filled with the same or a different fluid. The excited surface waves can manifest themselves by the resonances apparent in the sound scattering amplitude, which they cause upon phase matching following repeated circumnavigations of the target object, or by their re-radiation into the external fluid in the manner of head waves. We plot dispersion curves versus frequency of the surface waves, which for evacuated shells have a generally rising character, while the fluid filling adds an additional set of circumferential waves that descend with frequency. The resonances of these latter waves may also be interpreted as being due to phase matching, but they may alternately be interpreted as constituting the eigenfrequencies of the internal fluid contained in an elastic enclosure.
Generalized transformations and coordinates for static spherically symmetric general relativity.
Hill, James M; O'Leary, Joseph
2018-04-01
We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.
Generalized transformations and coordinates for static spherically symmetric general relativity
2018-01-01
We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington–Finkelstein transformation and the Kruskal–Szekeres coordinates. PMID:29765624
2007-07-01
Micci and A. Ketsdever, AIAA Progress in Astronautics and Aeronautics, Vol 187, pp. 45-137, 2000. 3. Janson, S., Helvajian , H ., Hansen, W., and...the radius of the propellant tank. The volume of the empty portion of a spherical propellant tank is given by ( )2 21 33e e t eV h r hπ= + (1...Where the resulting height of the propellant is 2p t eh r h = − (2) A correlation between p t h r and w m M is found in ref. 10. For the
2016-07-01
Particles (VLPs). The rationale is based on the beneficial effect of SV40 VLPs on an Acute Kidney Injury (AKI) model in mice, previously demonstrated...signaling which, as was demonstrated, protect mice kidneys from apoptosis, necrosis and consequent damage induced by a toxic (mercury) insult, increasing...recombinant VP1, without any genetic material. Using a mouse model for toxic Acute Kidney Injury (AKI), we demonstrated that systemic
Small terminase couples viral DNA-binding to genome-packaging ATPase activity
Roy, Ankoor; Bhardwaj, Anshul; Datta, Pinaki; Lander, Gabriel C.; Cingolani, Gino
2012-01-01
SUMMARY Packaging of viral genomes into empty procapsids is powered by a large DNA-packaging motor. In most viruses, this machine is composed of a large (L) and a small (S) terminase subunit complexed with a dodecamer of portal protein. Here, we describe the 1.75 Å crystal structure of the bacteriophage P22 S-terminase in a nonameric conformation. The structure presents a central channel ~23 Å in diameter, sufficiently large to accommodate hydrated B-DNA. The last 23 residues of S-terminase are essential for binding to DNA and assembly to L-terminase. Upon binding to its own DNA, S-terminase functions as a specific activator of L-terminase ATPase activity. The DNA-dependent stimulation of ATPase activity thus rationalizes the exclusive specificity of genome-packaging motors for viral DNA in the crowd of host DNA, ensuring fidelity of packaging and avoiding wasteful ATP hydrolysis. This posits a model for DNA-dependent activation of genome-packaging motors of general interest in virology. PMID:22771211
Wu, Shuo; Zhao, Qiong; Zhang, Pinghu; Kulp, John; Hu, Lydia; Hwang, Nicky; Zhang, Jiming; Block, Timothy M; Xu, Xiaodong; Du, Yanming; Chang, Jinhong; Guo, Ju-Tao
2017-08-15
Chronic hepatitis B virus (HBV) infection is a global public health problem. Although the currently approved medications can reliably reduce the viral load and prevent the progression of liver diseases, they fail to cure the viral infection. In an effort toward discovery of novel antiviral agents against HBV, a group of benzamide (BA) derivatives that significantly reduced the amount of cytoplasmic HBV DNA were discovered. The initial lead optimization efforts identified two BA derivatives with improved antiviral activity for further mechanistic studies. Interestingly, similar to our previously reported sulfamoylbenzamides (SBAs), the BAs promote the formation of empty capsids through specific interaction with HBV core protein but not other viral and host cellular components. Genetic evidence suggested that both SBAs and BAs inhibited HBV nucleocapsid assembly by binding to the heteroaryldihydropyrimidine (HAP) pocket between core protein dimer-dimer interfaces. However, unlike SBAs, BA compounds uniquely induced the formation of empty capsids that migrated more slowly in native agarose gel electrophoresis from A36V mutant than from the wild-type core protein. Moreover, we showed that the assembly of chimeric capsids from wild-type and drug-resistant core proteins was susceptible to multiple capsid assembly modulators. Hence, HBV core protein is a dominant antiviral target that may suppress the selection of drug-resistant viruses during core protein-targeting antiviral therapy. Our studies thus indicate that BAs are a chemically and mechanistically unique type of HBV capsid assembly modulators and warranted for further development as antiviral agents against HBV. IMPORTANCE HBV core protein plays essential roles in many steps of the viral replication cycle. In addition to packaging viral pregenomic RNA (pgRNA) and DNA polymerase complex into nucleocapsids for reverse transcriptional DNA replication to take place, the core protein dimers, existing in several different quaternary structures in infected hepatocytes, participate in and regulate HBV virion assembly, capsid uncoating, and covalently closed circular DNA (cccDNA) formation. It is anticipated that small molecular core protein assembly modulators may disrupt one or multiple steps of HBV replication, depending on their interaction with the distinct quaternary structures of core protein. The discovery of novel core protein-targeting antivirals, such as benzamide derivatives reported here, and investigation of their antiviral mechanism may lead to the identification of antiviral therapeutics for the cure of chronic hepatitis B. Copyright © 2017 American Society for Microbiology.
Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong
2016-02-01
Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection. Copyright © 2015 Elsevier B.V. All rights reserved.
Liao, Yang-Wen-Ke; Liu, Ya-Ru; Liang, Jia-Yang; Wang, Wen-Ping; Zhou, Jie; Xia, Xiao-Jian; Zhou, Yan-Hong; Yu, Jing-Quan; Shi, Kai
2015-03-01
Salicylic acid (SA) plays a critical role in plant defense against pathogen attack. The SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense, which is pathogenesis-related protein-independent but involves an RNA-dependent RNA polymerase 1 (RDR1)-mediated RNA silencing mechanism and/or an alternative oxidase (AOX)-associated defense pathway. However, the relationship between these two viral defense-related pathways remains unclear. In this study, Tobacco mosaic virus (TMV) inoculation onto Solanum lycopersicum (tomato) leaves induced a rapid induction of the SlAOX1a transcript level as well as the total and CN-resistant respiration at 0.5 dpi, followed by an increase in SlRDR1 gene expression at 1 dpi in the upper uninoculated leaves. Silencing SlRDR1 using virus-induced gene silencing system significantly reduced SlRDR1 expression and tomato defense against TMV but had no evident effect on SlAOX1a transcription. Conversely, silencing SlAOX1a not only effectively reduced the AOX1a transcript level, but also blocked the TMV-induced SlRDR1 expression and decreased the basal defense against TMV. Furthermore, the application of an exogenous AOX activator on empty vector-silenced control plants greatly induced the accumulation of SlRDR1 and SlAOX1a transcript and reduced TMV viral RNA accumulation, but failed to have such effects on SlRDR1-silenced plants. Moreover, RDR1-overexpressed transgenic Nicotiana benthamiana plants enhanced defense against TMV than the empty vector-transformed plants, but these effects were not affected by the exogenous AOX activator or inhibitor. These results indicate that RDR1 is involved in the AOX-mediated defense pathway against TMV infection and plays a crucial role in enhancing RNA silencing to limit virus systemic spread.
Post-buckling of a pressured biopolymer spherical shell with the mode interaction
NASA Astrophysics Data System (ADS)
Zhang, Lei; Ru, C. Q.
2018-03-01
Imperfection sensitivity is essential for mechanical behaviour of biopolymer shells characterized by high geometric heterogeneity. The present work studies initial post-buckling and imperfection sensitivity of a pressured biopolymer spherical shell based on non-axisymmetric buckling modes and associated mode interaction. Our results indicate that for biopolymer spherical shells with moderate radius-to-thickness ratio (say, less than 30) and smaller effective bending thickness (say, less than 0.2 times average shell thickness), the imperfection sensitivity predicted based on the axisymmetric mode without the mode interaction is close to the present results based on non-axisymmetric modes with the mode interaction with a small (typically, less than 10%) relative errors. However, for biopolymer spherical shells with larger effective bending thickness, the maximum load an imperfect shell can sustain predicted by the present non-axisymmetric analysis can be significantly (typically, around 30%) lower than those predicted based on the axisymmetric mode without the mode interaction. In such cases, a more accurate non-axisymmetric analysis with the mode interaction, as given in the present work, is required for imperfection sensitivity of pressured buckling of biopolymer spherical shells. Finally, the implications of the present study to two specific types of biopolymer spherical shells (viral capsids and ultrasound contrast agents) are discussed.
Problems in understanding the structure and assembly of viruses
DOE Office of Scientific and Technical Information (OSTI.GOV)
King, J.
1997-12-01
Though viruses infect the cells of all groups of animals, plants, and microorganisms, their structures follow a limited number of general themes; spherical or cylindrical shells built of hundreds of repeated protein subunits enclosing a nucleic acid - DNA or RNA - genome. Since the 1960s it has been known that the protein shells of spherical viruses in fact conform to icosahedral symmetry or to subtle deviations from icosahedral symmetry. The construction of the shell lattices and the transformations they go through in the different stages of the viral life cycle are not fully understood. The shells contain the nucleicmore » in a highly condensed state, of unknown coiling/organization. Features of the well studied bacterial viruses will be reviewed, with examples from adenoviruses, herpesviruses, poliovirus, and HIV. The emergence of new viral disease has led to increased interest in the development of agents which interfere with virus reproduction at the level of the assembly or function of the organized particle. Recently computational approaches to the problem of virus assembly have made important contributions to clarifying shell assembly processes. 1 ref.« less
A minimal kinetic model for a viral DNA packaging machine.
Yang, Qin; Catalano, Carlos Enrique
2004-01-20
Terminase enzymes are common to both eukaryotic and prokaryotic double-stranded DNA viruses. These enzymes possess ATPase and nuclease activities that work in concert to "package" a viral genome into an empty procapsid, and it is likely that terminase enzymes from disparate viruses utilize a common packaging mechanism. Bacteriophage lambda terminase possesses a site-specific nuclease activity, a so-called helicase activity, a DNA translocase activity, and multiple ATPase catalytic sites that function to package viral DNA. Allosteric interactions between the multiple catalytic sites have been reported. This study probes these catalytic interactions using enzyme kinetic, photoaffinity labeling, and vanadate inhibition studies. The ensemble of data forms the basis for a minimal kinetic model for lambda terminase. The model incorporates an ADP-driven conformational reorganization of the terminase subunits assembled on viral DNA, which is central to the activation of a catalytically competent packaging machine. The proposed model provides a unifying mechanism for allosteric interaction between the multiple catalytic sites of the holoenzyme and explains much of the kinetic data in the literature. Given that similar packaging mechanisms have been proposed for viruses as dissimilar as lambda and the herpes viruses, the model may find general utility in our global understanding of the enzymology of virus assembly.
The structure and host entry of an invertebrate parvovirus.
Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter; Rossmann, Michael G
2013-12-01
The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome.
The Structure and Host Entry of an Invertebrate Parvovirus
Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter
2013-01-01
The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome. PMID:24027306
Azad, I S; Shekhar, M S; Thirunavukkarasu, A R; Jithendran, K P
2006-12-14
We studied the natural progression of viral nerve necrosis (VNN) in larvae of Asian seabass Lates calcarifer Bloch from 0 to 40 days post-hatch (dph). The hatchlings were reared in the vicinity of a confirmed nodavirus-affected older batch. Using light and electron microscopy (EM), we made a sequential analysis of histopathological manifestations in nerve tissue and other organs. There were no changes from the day of hatching until 4 dph. Larvae at 4 dph had viral particles in the intramuscular spaces underlying the skin, but the nerve cells of the brain were normal. The first signs of necrosis of the brain cells were observed at 6 dph. EM observations revealed characteristic membrane-bound viral particles measuring 30 nm in the cytoplasm of nerve cells of the brain, spinal cord and retina. Histological samples of fry examined when group mortalities reached 20 to 35% revealed highly vacuolated brains, empty nerve cell cytoplasm and viral particles in the intercellular spaces. Viral particles occurred extensively in the intramuscular spaces and the epidermal layers. These observations were corroborated by positive immunostaining of the virus-rich intramuscular spaces. EM studies also revealed progressive necrotic changes in the cells harboring the virus. Results emphasize the need to maintain hygiene in the hatchery environment and to develop strategies for prevention of disease spread among cohabiting seabass and other susceptible fish larvae. Intramuscular localization of the nodavirus in both preclinical healthy-looking and post-clinical moribund larvae suggests that virus neutralization strategies during larval development could be effective in controlling VNN-associated mortalities.
Bovine Enteroviruses as Indicators of Fecal Contamination
Ley, Victoria; Higgins, James; Fayer, Ronald
2002-01-01
Surface waters frequently have been contaminated with human enteric viruses, and it is likely that animal enteric viruses have contaminated surface waters also. Bovine enteroviruses (BEV), found in cattle worldwide, usually cause asymptomatic infections and are excreted in the feces of infected animals in large numbers. In this study, the prevalence and genotype of BEV in a closed herd of cattle were evaluated and compared with BEV found in animals in the immediate environment and in environmental specimens. BEV was found in feces from 76% of cattle, 38% of white-tailed deer, and one of three Canada geese sharing the same pastures, as well as the water obtained from animal watering tanks, from the pasture, from streams running from the pasture to an adjacent river, and from the river, which emptied into the Chesapeake Bay. Furthermore, BEV was found in oysters collected from that river downstream from the farm. These findings suggest that BEV could be used as an indicator of fecal pollution originating from animals (cattle and/or deer). Partial sequence analysis of the viral genomes indicates that different viral variants coexist in the same area. The possibility of identifying the viral strains found in the animals and in the contaminated areas by sequencing the RNA genome, could provide a tool to find the origin of the contamination and should be useful for epidemiological and viral molecular evolution studies. PMID:12089028
Risco, Cristina; Rodríguez, Juan R.; López-Iglesias, Carmen; Carrascosa, José L.; Esteban, Mariano; Rodríguez, Dolores
2002-01-01
Vaccinia virus (VV) has a complex morphogenetic pathway whose first steps are poorly characterized. We have studied the early phase of VV assembly, when viral factories and spherical immature viruses (IVs) form in the cytoplasm of the infected cell. After freeze-substitution numerous cellular elements are detected around assembling viruses: membranes, ribosomes, microtubules, filaments, and unidentified structures. A double membrane is clearly resolved in the VV envelope for the first time, and freeze fracture reveals groups of tubules interacting laterally on the surface of the viroplasm foci. These data strongly support the hypothesis of a cellular tubulovesicular compartment, related to the endoplasmic reticulum-Golgi intermediate compartment (ERGIC), as the origin of the first VV envelope. Moreover, the cytoskeletal vimentin intermediate filaments are found around viral factories and inside the viroplasm foci, where vimentin and the VV core protein p39 colocalize in the areas where crescents protrude. Confocal microscopy showed that ERGIC elements and vimentin filaments concentrate in the viral factories. We propose that modified cellular ERGIC membranes and vimentin intermediate filaments act coordinately in the construction of viral factories and the first VV form through a unique mechanism of viral morphogenesis from cellular elements. PMID:11799179
Self-assembled virus-like particles with magnetic cores.
Huang, Xinlei; Bronstein, Lyudmila M; Retrum, John; Dufort, Chris; Tsvetkova, Irina; Aniagyei, Stella; Stein, Barry; Stucky, Galen; McKenna, Brandon; Remmes, Nicholas; Baxter, David; Kao, C Cheng; Dragnea, Bogdan
2007-08-01
Efficient encapsulation of functionalized spherical nanoparticles by viral protein cages was found to occur even if the nanoparticle is larger than the inner cavity of the native capsid. This result raises the intriguing possibility of reprogramming the self-assembly of viral structural proteins. The iron oxide nanotemplates used in this work are superparamagnetic, with a blocking temperature of about 250 K, making these virus-like particles interesting for applications such as magnetic resonance imaging and biomagnetic materials. Another novel feature of the virus-like particle assembly described in this work is the use of an anionic lipid micelle coat instead of a molecular layer covalently bound to the inorganic nanotemplate. Differences between the two functionalization strategies are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Siyang; Gao, Song; Kondabagil, Kiran
2012-04-04
Tailed DNA bacteriophages assemble empty procapsids that are subsequently filled with the viral genome by means of a DNA packaging machine situated at a special fivefold vertex. The packaging machine consists of a 'small terminase' and a 'large terminase' component. One of the functions of the small terminase is to initiate packaging of the viral genome, whereas the large terminase is responsible for the ATP-powered translocation of DNA. The small terminase subunit has three domains, an N-terminal DNA-binding domain, a central oligomerization domain, and a C-terminal domain for interacting with the large terminase. Here we report structures of the centralmore » domain in two different oligomerization states for a small terminase from the T4 family of phages. In addition, we report biochemical studies that establish the function for each of the small terminase domains. On the basis of the structural and biochemical information, we propose a model for DNA packaging initiation.« less
L2, the minor capsid protein of papillomavirus
Wang, Joshua W.; Roden, Richard B.S.
2013-01-01
The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ~8kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. PMID:23689062
Wang, Dai; Parrish, Colin R.
1999-01-01
Phage display of cDNA clones prepared from feline cells was used to identify host cell proteins that bound to DNA-containing feline panleukopenia virus (FPV) capsids but not to empty capsids. One gene found in several clones encoded a heterogeneous nuclear ribonucleoprotein (hnRNP)-related protein (DBP40) that was very similar in sequence to the A/B-type hnRNP proteins. DBP40 bound specifically to oligonucleotides representing a sequence near the 5′ end of the genome which is exposed on the outside of the full capsid but did not bind most other terminal sequences. Adding purified DBP40 to an in vitro fill-in reaction using viral DNA as a template inhibited the production of the second strand after nucleotide (nt) 289 but prior to nt 469. DBP40 bound to various regions of the viral genome, including a region between nt 295 and 330 of the viral genome which has been associated with transcriptional attenuation of the parvovirus minute virus of mice, which is mediated by a stem-loop structure of the DNA and cellular proteins. Overexpression of the protein in feline cells from a plasmid vector made them largely resistant to FPV infection. Mutagenesis of the protein binding site within the 5′ end viral genome did not affect replication of the virus. PMID:10438866
Role of dynamic capsomere supply for viral capsid self-assembly
NASA Astrophysics Data System (ADS)
Boettcher, Marvin A.; Klein, Heinrich C. R.; Schwarz, Ulrich S.
2015-02-01
Many viruses rely on the self-assembly of their capsids to protect and transport their genomic material. For many viral systems, in particular for human viruses like hepatitis B, adeno or human immunodeficiency virus, that lead to persistent infections, capsomeres are continuously produced in the cytoplasm of the host cell while completed capsids exit the cell for a new round of infection. Here we use coarse-grained Brownian dynamics simulations of a generic patchy particle model to elucidate the role of the dynamic supply of capsomeres for the reversible self-assembly of empty T1 icosahedral virus capsids. We find that for high rates of capsomere influx only a narrow range of bond strengths exists for which a steady state of continuous capsid production is possible. For bond strengths smaller and larger than this optimal value, the reaction volume becomes crowded by small and large intermediates, respectively. For lower rates of capsomere influx a broader range of bond strengths exists for which a steady state of continuous capsid production is established, although now the production rate of capsids is smaller. Thus our simulations suggest that the importance of an optimal bond strength for viral capsid assembly typical for in vitro conditions can be reduced by the dynamic influx of capsomeres in a cellular environment.
Chu, C T; Howell, D N; Morgenlander, J C; Hulette, C M; McLendon, R E; Miller, S E
1999-10-01
The distinction between intracranial viral infections and inflammatory conditions requiring immunosuppression is important. Although specific laboratory reagents are readily available for some viruses, diagnosis of arbovirus infection is more difficult. Transmission electron microscopy (TEM) theoretically allows identification of viral particles independent of reagent availability, but it has limited sensitivity. We report two cases of human flavivirus encephalitis diagnosed by TEM. Laser scanning confocal microscopy (LSCM) was used in one case to survey unembedded tissue slices for focal abnormalities, from which fragments smaller than 1 mm2 were excised for epoxy embedding. This facilitated TEM identification of intracytoplasmic, budding, 35-40 nm spherical virus particles, confirmed by serology as St. Louis encephalitis. In contrast to mosquitoes and newborn mice, in which high viral loads are associated with minimal tissue responses, these biopsies showed florid angiodestructive inflammation and microgliosis, with rare virions in necrotic perivascular cells and astrocytes. To our knowledge, this represents the first ultrastructural study of St. Louis encephalitis in humans, indicating the potential value of LSCM-aided TEM.
Structural Characterization of H-1 Parvovirus: Comparison of Infectious Virions to Empty Capsids
Halder, Sujata; Nam, Hyun-Joo; Govindasamy, Lakshmanan; Vogel, Michèle; Dinsart, Christiane; Salomé, Nathalie; McKenna, Robert
2013-01-01
The structure of single-stranded DNA (ssDNA) packaging H-1 parvovirus (H-1PV), which is being developed as an antitumor gene delivery vector, has been determined for wild-type (wt) virions and noninfectious (empty) capsids to 2.7- and 3.2-Å resolution, respectively, using X-ray crystallography. The capsid viral protein (VP) structure consists of an α-helix and an eight-stranded anti-parallel β-barrel with large loop regions between the strands. The β-barrel and loops form the capsid core and surface, respectively. In the wt structure, 600 nucleotides are ordered in an interior DNA binding pocket of the capsid. This accounts for ∼12% of the H-1PV genome. The wt structure is identical to the empty capsid structure, except for side chain conformation variations at the nucleotide binding pocket. Comparison of the H-1PV nucleotides to those observed in canine parvovirus and minute virus of mice, two members of the genus Parvovirus, showed both similarity in structure and analogous interactions. This observation suggests a functional role, such as in capsid stability and/or ssDNA genome recognition for encapsulation. The VP structure differs from those of other parvoviruses in surface loop regions that control receptor binding, tissue tropism, pathogenicity, and antibody recognition, including VP sequences reported to determine tumor cell tropism for oncotropic rodent parvoviruses. These structures of H-1PV provide insight into structural features that dictate capsid stabilization following genome packaging and three-dimensional information applicable for rational design of tumor-targeted recombinant gene delivery vectors. PMID:23449783
Clonazepam release from poly(DL-lactide-co-glycolide) nanoparticles prepared by dialysis method.
Nah, J W; Paek, Y W; Jeong, Y I; Kim, D W; Cho, C S; Kim, S H; Kim, M Y
1998-08-01
Aim of this work is to prepare poly(DL-lactide-co-glycolide) (PLGA) nanoparticles by dialysis method without surfactant and to investigate drug loading capacity and drug release. The size of PLGA nanoparticles was 269.9 +/- 118.7 nm in intensity average and the morphology of PLGA nanoparticles was spherical shape from the observation of SEM and TEM. In the effect of drug loading contents on the particle size distribution, PLGA nanoparticles were monomodal pattern with narrow size distribution in the empty and lower drug loading nanoparticles whereas bi- or trimodal pattern was showed in the higher drug loading ones. Release of clonazepam from PLGA nanoparticles with higher drug loading contents was slower than that with lower loading contents.
Silvernanotherapy on the viral borne disease of silkworm Bombyx mori L.
NASA Astrophysics Data System (ADS)
Govindaraju, K.; Tamilselvan, S.; Kiruthiga, V.; Singaravelu, G.
2011-12-01
Antiviral assays of chemically and biologically synthesized silver nanoparticles were made against BmNPV ( Bombyx mori Nuclear Polyhedrosis Virus). Reduction of silver ions by sodium citrate and Spirulina platensis led to the formation of spherical silver nanoparticles of 40-60 and 7-16 nm size. Single cell protein ( Spirulina platensis)-synthesized silver nanoparticles showed the strongest antiviral activity. Immunological studies made on the silkworm Bombyx mori disclosed that a significant increase in the total hemocyte count and differential hemocyte count due to S. platensis-synthesized silver nanoparticles supplementation. Improvement in the defense mechanism was noticed from the strengthened peritrophic membrane of the digestive tract and the increased total protein. Overall, the results presented illustrate that single cell protein-synthesized silver nanoparticles supplementation is effective in controlling viral-borne diseases of the silkworm.
Packaging of Polyelectrolytes in Viral Capsids: The Interplay Between Polymer Length and Capsid Size
NASA Astrophysics Data System (ADS)
Knobler, Charles
2008-03-01
Each particle of the Cowpea Chlorotic Mottle Virus (CCMV) has a very small ``parts list,'' consisting of two components: a molecule of single-stranded RNA and a 190-residue protein that makes up the 28-nm diameter icosahedral capsid. When purified viral RNA and capsid protein are mixed in solution at an appropriate pH and ionic strength, infectious wild-type viruses form spontaneously. Virus-like particles (VLPs) are formed when the protein self assembles around other anionic polymers such as poly(styrene sulfonate) (PSS). Under different pH and ionic strength conditions the capsid protein can assemble by itself into empty capsids, multishell structures, tubes and sheets. To explore the effect on virion size of the competition between the preferred curvature of the protein and the size of the packaged cargo we have examined the formation of VLPs around PSS polymers with molecular weights ranging from 400 kDa to 3.4 MDa. Two distinct sizes are observed -- 22 nm for the lower molecular weights, jumping to 27 nm at 2 MDa. While under given conditions the size of PSS in solution is directly determined by its molecular weight, the self-complementarity of RNA makes its solution structure dependent on the nucleotide sequence as well. We have therefore employed Small-Angle X-ray Scattering and Fluorescence Correlation Spectroscopy to examine the sizes of viral and non-viral RNAs of identical lengths. A model for the assembly that includes both the self-interactions of the polyelectrolyte and the capsid proteins and the interactions between them provides insight into the experimental results.
NASA Astrophysics Data System (ADS)
Martín-González, Natalia; Guérin Darvas, Sofía M.; Durana, Aritz; Marti, Gerardo A.; Guérin, Diego M. A.; de Pablo, Pedro J.
2018-03-01
Even though viruses evolve mainly in liquid milieu, their horizontal transmission routes often include episodes of dry environment. Along their life cycle, some insect viruses, such as viruses from the Dicistroviridae family, withstand dehydrated conditions with presently unknown consequences to their structural stability. Here, we use atomic force microscopy to monitor the structural changes of viral particles of Triatoma virus (TrV) after desiccation. Our results demonstrate that TrV capsids preserve their genome inside, conserving their height after exposure to dehydrating conditions, which is in stark contrast with other viruses that expel their genome when desiccated. Moreover, empty capsids (without genome) resulted in collapsed particles after desiccation. We also explored the role of structural ions in the dehydration process of the virions (capsid containing genome) by chelating the accessible cations from the external solvent milieu. We observed that ion suppression helps to keep the virus height upon desiccation. Our results show that under drying conditions, the genome of TrV prevents the capsid from collapsing during dehydration, while the structural ions are responsible for promoting solvent exchange through the virion wall.
Targeted Molecular Imaging of Cancer Cells Using MS2-Based 129 Xe NMR
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jeong, Keunhong; Netirojjanakul, Chawita; Munch, Henrik K.
Targeted, selective, and highly sensitive 129Xe NMR nanoscale biosensors have been synthesized using a spherical MS2 viral capsid, Cryptophane A molecules, and DNA aptamers. The biosensors showed strong binding specificity toward targeted lymphoma cells (Ramos line). Hyperpolarized 129Xe NMR signal contrast and hyper-CEST 129Xe MRI image contrast indicated its promise as highly sensitive hyperpolarized 129Xe NMR nanoscale biosensor for future applications in cancer detection in vivo.
Xu, Rui-Gang; Jenkins, Huw T.; Chechik, Maria; Blagova, Elena V.; Lopatina, Anna; Klimuk, Evgeny; Minakhin, Leonid; Severinov, Konstantin
2017-01-01
Abstract Bacteriophages and large dsDNA viruses encode sophisticated machinery to translocate their DNA into a preformed empty capsid. An essential part of this machine, the large terminase protein, processes viral DNA into constituent units utilizing its nuclease activity. Crystal structures of the large terminase nuclease from the thermophilic bacteriophage G20c show that it is most similar to the RuvC family of the RNase H-like endonucleases. Like RuvC proteins, the nuclease requires either Mn2+, Mg2+ or Co2+ ions for activity, but is inactive with Zn2+ and Ca2+. High resolution crystal structures of complexes with different metals reveal that in the absence of DNA, only one catalytic metal ion is accommodated in the active site. Binding of the second metal ion may be facilitated by conformational variability, which enables the two catalytic aspartic acids to be brought closer to each other. Structural comparison indicates that in common with the RuvC family, the location of the two catalytic metals differs from other members of the RNase H family. In contrast to a recently proposed mechanism, the available data do not support binding of the two metals at an ultra-short interatomic distance. Thus we postulate that viral terminases cleave DNA by the canonical RuvC-like mechanism. PMID:28100693
Precise algorithm to generate random sequential adsorption of hard polygons at saturation
NASA Astrophysics Data System (ADS)
Zhang, G.
2018-04-01
Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation" limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles and could thus determine the saturation density of spheres with high accuracy. In this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensional polygons. We also calculate the saturation density for regular polygons of three to ten sides and obtain results that are consistent with previous, extrapolation-based studies.
Precise algorithm to generate random sequential adsorption of hard polygons at saturation.
Zhang, G
2018-04-01
Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation" limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles and could thus determine the saturation density of spheres with high accuracy. In this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensional polygons. We also calculate the saturation density for regular polygons of three to ten sides and obtain results that are consistent with previous, extrapolation-based studies.
Wang, Xiaoli; Ku, Zhiqiang; Zhang, Xiang; Ye, Xiaohua; Chen, Jinhuan; Liu, Qingwei; Zhang, Wei; Zhang, Chao; Fu, Zhenglin; Jin, Xia; Cong, Yao; Huang, Zhong
2018-01-01
Enterovirus 71 (EV71) is the major causative agent of severe hand, foot, and mouth disease, which affects millions of young children in the Asia-Pacific region annually. In this study, we engineered a novel EV71 virus-like particle (VLP) that lacks VP4 (therefore designated VLP ΔVP4 ) and investigated its structure, antigenicity, and vaccine potential. The cryo-electron microscopy (cryo-EM) structure of VLP ΔVP4 was reconstructed to 3.71-Å resolution. Results from structural and biochemical analyses revealed that VLP ΔVP4 resembles the end product of the viral uncoating process, the 80S empty capsid. VLP ΔVP4 is able to elicit high-titer neutralizing antibodies and to fully protect mice against lethal viral challenge. Mechanistic studies showed that, at the cellular level, the anti-VLP ΔVP4 sera exert neutralization effects at both pre- and postattachment stages by inhibiting both virus attachment and internalization, and at the molecular level, the antisera can block multiple interactions between EV71 and its key receptors. Our study gives a better understanding of EV71 capsid assembly and provides important information for the design and development of new-generation vaccines for EV71, and perhaps for other enteroviruses, as well. IMPORTANCE Enterovirus 71 (EV71) infection may lead to severe hand, foot, and mouth disease, with significant morbidity and mortality. Knowledge regarding EV71 particle assembly remains limited. Here, we report the generation and characterization of a novel EV71 virus-like particle that lacks the VP4 capsid subunit protein. This particle, termed VLP ΔVP4 , structurally mimics the 80S empty capsid, which is the end stage of EV71 uncoating. We further show that VLP ΔVP4 exhibits desirable immunogenicity and protective efficacy in proof-of-concept studies. In addition, the inhibitory mechanisms of the VLP ΔVP4 -induced antibodies are unraveled at both the cellular and molecular levels. Our work provides the first evidence of picornaviral particle assembly in the complete absence of VP4 and identifies VLP ΔVP4 as an improved EV71 vaccine candidate with desirable traits. These findings not only enhance our understanding of particle assembly and uncoating of picornaviruses, but also provide important information for structure-guided vaccine design for EV71 and other enteroviruses. Copyright © 2017 American Society for Microbiology.
Single dose of an adenovirus vectored mouse interferon-α protects mice from lethal EV71 challenge.
Sun, Jialei; Ennis, Jane; Turner, Jeffrey D; Chu, Justin Jang Hann
2016-10-01
Enterovirus 71 (EV71) causes hand-foot-and-mouth diseases as well as neurological complications in young children. Interferon (IFN) can inhibit the replication of many viruses with low cytotoxic effects. Previously, an adenovirus vectored mouse interferon-α (DEF201), subtype 5, was generated by Wu et al, 2007. In this study, the antiviral effects of DEF201 against EV71 were evaluated in a murine model. 6-day-old BALB/c mice were administered a single dose of DEF201 before or after infection with lethal dose of EV71. The survival rate, clinical symptoms, tissue viral loads and histology pathogenesis were evaluated. IFN gene expression following a single dose of DEF201 maintained high concentrations of 100-9000 pg/mL for more than 7 days in mice serum. Pre-infection administration of a single dose of 10 6 PFU of DEF201 offered full protection of the mice against EV71 infection compared with the empty Ad5 vector control. In addition, virus load in DEF201-treated mice muscle tissue was significantly decreased as compared with empty vector control. Histopathology analysis revealed that DEF201 significantly prevented the development of severe tissue damage with reduction of viral antigen in the murine muscle tissue. Post-infection treatment at 6 h offered full protection and partial protection at 12 h, indicating that DEF201 could be used as an anti-EV71 therapeutic agent in early stage of EV71 infection. In addition, our study showed that DEF201 enhanced the neutralization ability of serum in EV71-vaccinated mice, implying that DEF201 could promote the production of specific anti-EV71 antibodies. In conclusion, single dose of DEF201 is highly efficacious as a prophylactic agent against EV71 infection in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.
Encapsidation of Linear Polyelectrolyte in a Viral Nanocontainer
NASA Astrophysics Data System (ADS)
Hu, Yufang
2005-03-01
We present the results from a combined experimental and theoretical study on the self-assembly of a model icosahedral virus, Cowpea Chlorotic Mottle Virus (CCMV). The formation of native CCMV capsids is believed to be driven primarily by the electrostatic interactions between the viral RNA and the positively charged capsid interior, as well as by the hydrophobic interactions between capsid protein subunits. To probe these molecular interactions, in vitro self-assembly reactions are carried out using the CCMV capsid protein and a synthetic linear polyelectrolyte, sodium polystyrene sulfonate (NaPSS), which functions as the analog of viral RNA. Under appropriate solutions conditions, NaPSS is encapsidated by the viral capsid. The molecular weight of NaPSS is systematically varied and the resulting average capsid size, size distribution, and particle morphology are measured by transmission electron microscopy. The correlation between capsid size and packaged cargo size, as well as the upper limit of capsid packaging capacity, are characterized. To elucidate the physical role played by the encapsidated polyelectrolyte in determining the preferred size of spherical viruses, we have used a mean-field approach to calculate the free energy of the virus-like particle as a function of chain length (and of the strength of chain/capsid attractive interaction). We find good agreement with our analytical calculations and experimental results.
Virus-mimetic nanovesicles as a versatile antigen-delivery system
Zhang, Pengfei; Chen, Yixin; Zeng, Yun; Shen, Chenguang; Li, Rui; Guo, Zhide; Li, Shaowei; Zheng, Qingbing; Chu, Chengchao; Wang, Zhantong; Zheng, Zizheng; Tian, Rui; Ge, Shengxiang; Zhang, Xianzhong; Xia, Ning-Shao; Liu, Gang; Chen, Xiaoyuan
2015-01-01
It is a critically important challenge to rapidly design effective vaccines to reduce the morbidity and mortality of unexpected pandemics. Inspired from the way that most enveloped viruses hijack a host cell membrane and subsequently release by a budding process that requires cell membrane scission, we genetically engineered viral antigen to harbor into cell membrane, then form uniform spherical virus-mimetic nanovesicles (VMVs) that resemble natural virus in size, shape, and specific immunogenicity with the help of surfactants. Incubation of major cell membrane vesicles with surfactants generates a large amount of nano-sized uniform VMVs displaying the native conformational epitopes. With the diverse display of epitopes and viral envelope glycoproteins that can be functionally anchored onto VMVs, we demonstrate VMVs to be straightforward, robust and tunable nanobiotechnology platforms for fabricating antigen delivery systems against a wide range of enveloped viruses. PMID:26504197
Use of protein cages as a template for confined synthesis of inorganic and organic nanoparticles.
Uchida, Masaki; Qazi, Shefah; Edwards, Ethan; Douglas, Trevor
2015-01-01
Protein cages are hollow spherical proteins assembled from a defined number of subunits. Because they are extremely homogeneous in size and structure, their interior cavities can serve as ideal templates to encapsulate and synthesize well-defined nanoparticles. Here, we describe the exemplary synthesis of a hard and a soft material in two representative protein cages, i.e., magnetite nanoparticles in ferritin and a poly(2-aminoethyl)methacrylate inside a viral capsid derived from the bacteriophage P22.
NASA Astrophysics Data System (ADS)
Roshal, D. S.; Konevtsova, O. V.; Myasnikova, A. E.; Rochal, S. B.
2016-11-01
We consider how to control the extension of curvature-induced defects in the hexagonal order covering different curved surfaces. In these frames we propose a physical mechanism for improving structures of two-dimensional spherical colloidal crystals (SCCs). For any SCC comprising of about 300 or less particles the mechanism transforms all extended topological defects (ETDs) in the hexagonal order into the point disclinations. Perfecting the structure is carried out by successive cycles of the particle implantation and subsequent relaxation of the crystal. The mechanism is potentially suitable for obtaining colloidosomes with better selective permeability. Our approach enables modeling the most topologically regular tubular and conical two-dimensional nanocrystals including various possible polymorphic forms of the HIV viral capsid. Different HIV-like shells with an arbitrary number of structural units (SUs) and desired geometrical parameters are easily formed. Faceting of the obtained structures is performed by minimizing the suggested elastic energy.
Lu, Wen-Chien; Chiang, Been-Huang; Huang, Da-Wei; Li, Po-Hsien
2014-03-01
Nanoemulsions can be used for transporting pharmaceutical phytochemicals in skin-care products because of their stability and rapid permeation properties. However, droplet size may be a critical factor aiding permeation through skin and transdermal delivery efficiency. We prepared D-limonene nanoemulsions with various droplet sizes by ultrasonic emulsification using mixed surfactants of sorbitane trioleate and polyoxyethylene (20) oleyl ether under different hydrophilic-lipophilic balance (HLB) values. Droplet size decreased with increasing HLB value. With HLB 12, the droplet size was 23 nm, and the encapsulated ratio peaked at 92.3%. Transmission electron microscopy revealed spherical droplets and the gray parts were D-limonene precipitation incorporated in spherical droplets of the emulsion system. Franz diffusion cell was used to evaluate the permeation of D-limonene nanoemulsion through rat abdominal skin; the permeation rate depended on droplet size. The emulsion with the lowest droplet size (54 nm) achieved the maximum permeation rate. The concentration of D-limonene in the skin was 40.11 μL/cm(2) at the end of 360 min. Histopathology revealed no distinct voids or empty spaces in the epidermal region of permeated rat skin, so the D-limonene nanoemulsion may be a safe carrier for transdermal drug delivery. Copyright © 2013 Elsevier B.V. All rights reserved.
Phylogenetic Diversity of T4-Type Phages in Sediments from the Subtropical Pearl River Estuary
He, Maoqiu; Cai, Lanlan; Zhang, Chuanlun; Jiao, Nianzhi; Zhang, Rui
2017-01-01
Viruses are an abundant and active component of marine sediments and play a significant role in microbial ecology and biogeochemical cycling at local and global scales. To obtain a better understanding of the ecological characteristics of the viriobenthos, the abundance and morphology of viruses and the diversity and community structure of T4-type phages were systematically investigated in the surface sediments of the subtropical Pearl River Estuary (PRE). Viral abundances ranged from 4.49 × 108 to 11.7 × 108 viruses/g and prokaryotic abundances ranged from 2.63 × 108 to 9.55 × 108 cells/g, and both decreased from freshwater to saltwater. Diverse viral morphotypes, including tailed, spherical, filamentous, and rod-shaped viruses, were observed using transmission electron microscopy. Analysis of the major capsid gene (g23) indicated that the sediment T4-type phages were highly diverse and, similar to the trend in viral abundances, their diversity decreased as the salinity increased. Phylogenetic analysis suggested that most of the g23 operational taxonomic units were affiliated with marine, paddy soil, and lake groups. The T4-type phage communities in freshwater and saltwater sediments showed obvious differences, which were related to changes in the Pearl River discharge. The results of this study demonstrated both allochthonous and autochthonous sources of the viral community in the PRE sediments and the movement of certain T4-type viral groups between the freshwater and saline water biomes. PMID:28572798
Sheffler, Will; Baker, David
2009-01-01
We present a novel method called RosettaHoles for visual and quantitative assessment of underpacking in the protein core. RosettaHoles generates a set of spherical cavity balls that fill the empty volume between atoms in the protein interior. For visualization, the cavity balls are aggregated into contiguous overlapping clusters and small cavities are discarded, leaving an uncluttered representation of the unfilled regions of space in a structure. For quantitative analysis, the cavity ball data are used to estimate the probability of observing a given cavity in a high-resolution crystal structure. RosettaHoles provides excellent discrimination between real and computationally generated structures, is predictive of incorrect regions in models, identifies problematic structures in the Protein Data Bank, and promises to be a useful validation tool for newly solved experimental structures.
Precise algorithm to generate random sequential adsorption of hard polygons at saturation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, G.
Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation'' limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles, and could thus determine the saturation density of spheres with high accuracy. Here in this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensionalmore » polygons. We also calculate the saturation density for regular polygons of three to ten sides, and obtain results that are consistent with previous, extrapolation-based studies.« less
Precise algorithm to generate random sequential adsorption of hard polygons at saturation
Zhang, G.
2018-04-30
Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation'' limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles, and could thus determine the saturation density of spheres with high accuracy. Here in this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensionalmore » polygons. We also calculate the saturation density for regular polygons of three to ten sides, and obtain results that are consistent with previous, extrapolation-based studies.« less
Sheffler, Will; Baker, David
2009-01-01
We present a novel method called RosettaHoles for visual and quantitative assessment of underpacking in the protein core. RosettaHoles generates a set of spherical cavity balls that fill the empty volume between atoms in the protein interior. For visualization, the cavity balls are aggregated into contiguous overlapping clusters and small cavities are discarded, leaving an uncluttered representation of the unfilled regions of space in a structure. For quantitative analysis, the cavity ball data are used to estimate the probability of observing a given cavity in a high-resolution crystal structure. RosettaHoles provides excellent discrimination between real and computationally generated structures, is predictive of incorrect regions in models, identifies problematic structures in the Protein Data Bank, and promises to be a useful validation tool for newly solved experimental structures. PMID:19177366
RNAi-derived transgenic resistance to Mungbean yellow mosaic India virus in cowpea.
Kumar, Sanjeev; Tanti, Bhaben; Patil, Basavaprabhu L; Mukherjee, Sunil Kumar; Sahoo, Lingaraj
2017-01-01
Cowpea is an important grain legume crop of Africa, Latin America, and Southeast Asia. Leaf curl and golden mosaic diseases caused by Mungbean yellow mosaic India virus (MYMIV) have emerged as most devastating viral diseases of cowpea in Southeast Asia. In this study, we employed RNA interference (RNAi) strategy to control cowpea-infecting MYMIV. For this, we generated transgenic cowpea plants harbouring three different intron hairpin RNAi constructs, containing the AC2, AC4 and fusion of AC2 and AC4 (AC2+AC4) of seven cowpea-infecting begomoviruses. The T0 and T1 transgenic cowpea lines of all the three constructs accumulated transgene-specific siRNAs. Transgenic plants were further assayed up to T1 generations, for resistance to MYMIV using agro-infectious clones. Nearly 100% resistance against MYMIV infection was observed in transgenic lines, expressing AC2-hp and AC2+AC4-hp RNA, when compared with untransformed controls and plants transformed with empty vectors, which developed severe viral disease symptoms within 3 weeks. The AC4-hp RNA expressing lines displayed appearance of milder symptoms after 5 weeks of MYMIV-inoculation. Northern blots revealed a positive correlation between the level of transgene-specific siRNAs accumulation and virus resistance. The MYMIV-resistant transgenic lines accumulated nearly zero or very low titres of viral DNA. The transgenic cowpea plants had normal phenotype with no yield penalty in greenhouse conditions. This is the first demonstration of RNAi-derived resistance to MYMIV in cowpea.
RNAi-derived transgenic resistance to Mungbean yellow mosaic India virus in cowpea
Kumar, Sanjeev; Tanti, Bhaben; Patil, Basavaprabhu L.; Mukherjee, Sunil Kumar
2017-01-01
Cowpea is an important grain legume crop of Africa, Latin America, and Southeast Asia. Leaf curl and golden mosaic diseases caused by Mungbean yellow mosaic India virus (MYMIV) have emerged as most devastating viral diseases of cowpea in Southeast Asia. In this study, we employed RNA interference (RNAi) strategy to control cowpea-infecting MYMIV. For this, we generated transgenic cowpea plants harbouring three different intron hairpin RNAi constructs, containing the AC2, AC4 and fusion of AC2 and AC4 (AC2+AC4) of seven cowpea-infecting begomoviruses. The T0 and T1 transgenic cowpea lines of all the three constructs accumulated transgene-specific siRNAs. Transgenic plants were further assayed up to T1 generations, for resistance to MYMIV using agro-infectious clones. Nearly 100% resistance against MYMIV infection was observed in transgenic lines, expressing AC2-hp and AC2+AC4-hp RNA, when compared with untransformed controls and plants transformed with empty vectors, which developed severe viral disease symptoms within 3 weeks. The AC4-hp RNA expressing lines displayed appearance of milder symptoms after 5 weeks of MYMIV-inoculation. Northern blots revealed a positive correlation between the level of transgene-specific siRNAs accumulation and virus resistance. The MYMIV-resistant transgenic lines accumulated nearly zero or very low titres of viral DNA. The transgenic cowpea plants had normal phenotype with no yield penalty in greenhouse conditions. This is the first demonstration of RNAi-derived resistance to MYMIV in cowpea. PMID:29077738
Guo, Fang; Zhao, Qiong; Sheraz, Muhammad; Cheng, Junjun; Qi, Yonghe; Su, Qing; Cuconati, Andrea; Wei, Lai; Du, Yanming; Li, Wenhui; Chang, Jinhong; Guo, Ju-Tao
2017-09-01
Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or "empty" capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Jehoon; Wu, Jianzhong, E-mail: jwu@engr.ucr.edu
Self-assembly of capsid proteins and genome encapsidation are two critical steps in the life cycle of most plant and animal viruses. A theoretical description of such processes from a physiochemical perspective may help better understand viral replication and morphogenesis thus provide fresh insights into the experimental studies of antiviral strategies. In this work, we propose a molecular thermodynamic model for predicting the stability of Hepatitis B virus (HBV) capsids either with or without loading nucleic materials. With the key components represented by coarse-grained thermodynamic models, the theoretical predictions are in excellent agreement with experimental data for the formation free energiesmore » of empty T4 capsids over a broad range of temperature and ion concentrations. The theoretical model predicts T3/T4 dimorphism also in good agreement with the capsid formation at in vivo and in vitro conditions. In addition, we have studied the stability of the viral particles in response to physiological cellular conditions with the explicit consideration of the hydrophobic association of capsid subunits, electrostatic interactions, molecular excluded volume effects, entropy of mixing, and conformational changes of the biomolecular species. The course-grained model captures the essential features of the HBV nucleocapsid stability revealed by recent experiments.« less
A molecular thermodynamic model for the stability of hepatitis B capsids
NASA Astrophysics Data System (ADS)
Kim, Jehoon; Wu, Jianzhong
2014-06-01
Self-assembly of capsid proteins and genome encapsidation are two critical steps in the life cycle of most plant and animal viruses. A theoretical description of such processes from a physiochemical perspective may help better understand viral replication and morphogenesis thus provide fresh insights into the experimental studies of antiviral strategies. In this work, we propose a molecular thermodynamic model for predicting the stability of Hepatitis B virus (HBV) capsids either with or without loading nucleic materials. With the key components represented by coarse-grained thermodynamic models, the theoretical predictions are in excellent agreement with experimental data for the formation free energies of empty T4 capsids over a broad range of temperature and ion concentrations. The theoretical model predicts T3/T4 dimorphism also in good agreement with the capsid formation at in vivo and in vitro conditions. In addition, we have studied the stability of the viral particles in response to physiological cellular conditions with the explicit consideration of the hydrophobic association of capsid subunits, electrostatic interactions, molecular excluded volume effects, entropy of mixing, and conformational changes of the biomolecular species. The course-grained model captures the essential features of the HBV nucleocapsid stability revealed by recent experiments.
Monte Carlo simulations of polyelectrolytes inside viral capsids.
Angelescu, Daniel George; Bruinsma, Robijn; Linse, Per
2006-04-01
Structural features of polyelectrolytes as single-stranded RNA or double-stranded DNA confined inside viral capsids and the thermodynamics of the encapsidation of the polyelectrolyte into the viral capsid have been examined for various polyelectrolyte lengths by using a coarse-grained model solved by Monte Carlo simulations. The capsid was modeled as a spherical shell with embedded charges and the genome as a linear jointed chain of oppositely charged beads, and their sizes corresponded to those of a scaled-down T=3 virus. Counterions were explicitly included, but no salt was added. The encapisdated chain was found to be predominantly located at the inner capsid surface, in a disordered manner for flexible chains and in a spool-like structure for stiff chains. The distribution of the small ions was strongly dependent on the polyelectrolyte-capsid charge ratio. The encapsidation enthalpy was negative and its magnitude decreased with increasing polyelectrolyte length, whereas the encapsidation entropy displayed a maximum when the capsid and polyelectrolyte had equal absolute charge. The encapsidation process remained thermodynamically favorable for genome charges ca. 3.5 times the capsid charge. The chain stiffness had only a relatively weak effect on the thermodynamics of the encapsidation.
Cryo-Electron Tomography of Rubella Virus
Battisti, Anthony J.; Yoder, Joshua D.; Plevka, Pavel; Winkler, Dennis C.; Mangala Prasad, Vidya; Kuhn, Richard J.; Frey, Teryl K.; Steven, Alasdair C.
2012-01-01
Rubella virus is the only member of the Rubivirus genus within the Togaviridae family and is the causative agent of the childhood disease known as rubella or German measles. Here, we report the use of cryo-electron tomography to examine the three-dimensional structure of rubella virions and compare their structure to that of Ross River virus, a togavirus belonging the genus Alphavirus. The ectodomains of the rubella virus glycoproteins, E1 and E2, are shown to be organized into extended rows of density, separated by 9 nm on the viral surface. We also show that the rubella virus nucleocapsid structure often forms a roughly spherical shell which lacks high density at its center. While many rubella virions are approximately spherical and have dimensions similar to that of the icosahedral Ross River virus, the present results indicate that rubella exhibits a large degree of pleomorphy. In addition, we used rotation function calculations and other analyses to show that approximately spherical rubella virions lack the icosahedral organization which characterizes Ross River and other alphaviruses. The present results indicate that the assembly mechanism of rubella virus, which has previously been shown to differ from that of the alphavirus assembly pathway, leads to an organization of the rubella virus structural proteins that is different from that of alphaviruses. PMID:22855483
Cryo-electron tomography of rubella virus.
Battisti, Anthony J; Yoder, Joshua D; Plevka, Pavel; Winkler, Dennis C; Prasad, Vidya Mangala; Kuhn, Richard J; Frey, Teryl K; Steven, Alasdair C; Rossmann, Michael G
2012-10-01
Rubella virus is the only member of the Rubivirus genus within the Togaviridae family and is the causative agent of the childhood disease known as rubella or German measles. Here, we report the use of cryo-electron tomography to examine the three-dimensional structure of rubella virions and compare their structure to that of Ross River virus, a togavirus belonging the genus Alphavirus. The ectodomains of the rubella virus glycoproteins, E1 and E2, are shown to be organized into extended rows of density, separated by 9 nm on the viral surface. We also show that the rubella virus nucleocapsid structure often forms a roughly spherical shell which lacks high density at its center. While many rubella virions are approximately spherical and have dimensions similar to that of the icosahedral Ross River virus, the present results indicate that rubella exhibits a large degree of pleomorphy. In addition, we used rotation function calculations and other analyses to show that approximately spherical rubella virions lack the icosahedral organization which characterizes Ross River and other alphaviruses. The present results indicate that the assembly mechanism of rubella virus, which has previously been shown to differ from that of the alphavirus assembly pathway, leads to an organization of the rubella virus structural proteins that is different from that of alphaviruses.
Dynamical patterns in nematic active matter on a sphere
NASA Astrophysics Data System (ADS)
Henkes, Silke; Marchetti, M. Cristina; Sknepnek, Rastko
2018-04-01
Using simulations of self-propelled agents with short-range repulsion and nematic alignment, we explore the dynamical phases of a dense active nematic confined to the surface of a sphere. We map the nonequilibrium phase diagram as a function of curvature, alignment strength, and activity. Our model reproduces several phases seen in recent experiments on active microtubule bundles confined the surfaces of vesicles. At low driving, we recover the equilibrium nematic ground state with four +1 /2 defects. As the driving is increased, geodesic forces drive the transition to a polar band wrapping around an equator, with large empty spherical caps corresponding to two +1 defects at the poles. Upon further increasing activity, the bands fold onto themselves, and the system eventually transitions to a turbulent state marked by the proliferation of pairs of topological defects. We highlight the key role of the nematic persistence length in controlling pattern formation in these confined systems with positive Gaussian curvature.
Tidal capture of stars by a massive black hole
NASA Technical Reports Server (NTRS)
Novikov, I. D.; Pethick, C. J.; Polnarev, A. G.
1992-01-01
The processes leading to tidal capture of stars by a massive black hole and the consequences of these processes in a dense stellar cluster are discussed in detail. When the amplitude of a tide and the subsequent oscillations are sufficiently large, the energy deposited in a star after periastron passage and formation of a bound orbit cannot be estimated directly using the linear theory of oscillations of a spherical star, but rather numerical estimates must be used. The evolution of a star after tidal capture is discussed. The maximum ratio R of the cross-section for tidal capture to that for tidal disruption is about 3 for real systems. For the case of a stellar system with an empty capture loss cone, even in the case when the impact parameter for tidal capture only slightly exceeds the impact parameter for direct tidal disruption, tidal capture would be much more important than tidal disruption.
Bounded excursion stable gravastars and black holes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rocha, P; Miguelote, A Y; Chan, R
2008-06-15
Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. It is found that in some cases the models represent the 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes occurs. In the phase space, the region for the 'bounded excursion' gravastars ismore » very small in comparison to that of black holes, but not empty. Therefore, although the possibility of the existence of gravastars cannot be excluded from such dynamical models, our results indicate that, even if gravastars do indeed exist, that does not exclude the possibility of the existence of black holes.« less
Homogeneous alignment of liquid crystalline dendrimers confined in a slit-pore. A simulation study.
Workineh, Zerihun G; Vanakaras, Alexandros G
2016-03-23
In this work we present results from isobaric-isothermal (NPT) Monte Carlo simulation studies of model liquid crystalline dendrimer (LCDr) systems confined in a slit-pore made of two parallel flat walls. The dendrimers are modelled as a collection of spherical and ellipsoidal particles corresponding to the junction points of the dendritic core and to the mesogenic units respectively. Assuming planar uniform (unidirectional) soft anchoring of the mesogenic units on the substrates we investigate the conformational and alignment properties of the LCDr system at different thermodynamic state points. Tractable coarse grained force fields have been used from our previous work. At low pressures the interior of the pore is almost empty, since almost all LCDrs are anchored to the substrates forming two-dimensional smectic-like structures with the mesogens aligned along the aligning direction of the substrates. As the pressure grows the LCDrs occupy the whole pore. However, even at low temperatures, the smectic organization does not transmit in the interior of the pore and is preserved for distances of 2-3 mesogenic diameters from the walls. For this reason, the global orientational order decreases with increasing pressure (density). In the vicinity (2-3 mesogenic diameters) of the pore walls, mesogenic units preserve the smectic structure whose layers are separated by layers of spherical beads. In this region individual LCDrs possess a rod like shape.
Homogeneous alignment of liquid crystalline dendrimers confined in a slit-pore. A simulation study
NASA Astrophysics Data System (ADS)
Workineh, Zerihun G.; Vanakaras, Alexandros G.
2016-03-01
In this work we present results from isobaric-isothermal (NPT) Monte Carlo simulation studies of model liquid crystalline dendrimer (LCDr) systems confined in a slit-pore made of two parallel flat walls. The dendrimers are modelled as a collection of spherical and ellipsoidal particles corresponding to the junction points of the dendritic core and to the mesogenic units respectively. Assuming planar uniform (unidirectional) soft anchoring of the mesogenic units on the substrates we investigate the conformational and alignment properties of the LCDr system at different thermodynamic state points. Tractable coarse grained force fields have been used from our previous work. At low pressures the interior of the pore is almost empty, since almost all LCDrs are anchored to the substrates forming two-dimensional smectic-like structures with the mesogens aligned along the aligning direction of the substrates. As the pressure grows the LCDrs occupy the whole pore. However, even at low temperatures, the smectic organization does not transmit in the interior of the pore and is preserved for distances of 2-3 mesogenic diameters from the walls. For this reason, the global orientational order decreases with increasing pressure (density). In the vicinity (2-3 mesogenic diameters) of the pore walls, mesogenic units preserve the smectic structure whose layers are separated by layers of spherical beads. In this region individual LCDrs possess a rod like shape.
Camilleri, Michael; Breen, Mary; Ryks, Michael; Burton, Duane
2011-01-01
Background Interventions such as gastric surgery and erythromycin result in displacement of solids to the distal stomach and acceleration of overall and proximal gastric emptying. The effect of non-surgical impairment of gastric accommodation on gastric emptying is unclear. Non-surgical impairment of gastric accommodation is associated with accelerated gastric emptying. Aim To compare measurements of proximal and overall gastric emptying in patients with reduced postprandial gastric volume accommodation with the emptying rates in age- and gender-matched controls with normal postprandial gastric volume accommodation. Methods We evaluated overall and proximal gastric emptying in 9 patients with impaired gastric accommodation and age-equivalent and gender-matched controls. Gastric volumes and emptying were measured using validated SPECT and dual gamma camera scintigraphy respectively. We compared group differences in overall and proximal gastric emptying t1/2 by t test. Results Patients with impaired postprandial gastric volume accommodation had greater fasting gastric volume. The proportion of food emptied from the proximal stomach immediately after meal ingestion was lower and t1/2of proximal gastric emptying correspondingly longer in the group with reduced postprandial gastric accommodation. In contrast, differences were not detected in overall gastric emptying in the two groups, and the ratio of overall to proximal gastric emptying t1/2was greater in the group with impaired volume accommodation. Conclusions Proximal stomach emptying is reduced in patients with impaired postprandial volume accommodation; this difference occurs predominantly during the time of meal ingestion. Compensatory mechanisms that result in normal overall gastric emptying require further elucidation. PMID:21327917
Faust, A; Lange, E; Kaden, V
2007-11-01
The aim of this study was to evaluate the efficacy of lyophilised C-strain vaccine in domestic pigs and wild boar after oral application. A new spherical bait form (diameter 3 cm) containing lyophilised vaccine virus and the recent vaccine baits were used for animal experiments. Four vaccination groups were established in experiment 1 (group 1: recent liquid bait vaccine; group 2: spherical baits containing one dose of the lyophilised vaccine; groups 3 (domestic pigs) and 4 (wild boar): spherical baits containing two doses of the lyophilised vaccine) and two groups in experiment 2 (group 1: recent liquid bait vaccine; group 2: spherical baits with two doses of the lyophilised vaccine). Challenge was carried out with the highly virulent virus strain "Alfort 187" (using 100 TCID50 in the first and 1.000 TCID50 in the second experiment). Our results showed that the animals vaccinated with lyophilised C-strain vaccine developed high neutralising antibody titres comparable to those obtained after vaccination with the recent bait vaccine. All pigs which picked up the baits remained healthy after challenge. Neither clinical symptoms nor viremia or virus shedding were observed after infection except in one pig (group 2, experiment 2) which had not consumed the vaccine bait. The surviving domestic pigs and wild boar were tested negative for CSFV and viral RNA at the end of the study. This result demonstrates that lyophilised vaccine may become an effective vaccine formulation for oral immunisation of wild boar against CSF in the near future.
Effect of colectomy on gastric emptying in idiopathic slow-transit constipation.
Hemingway, D M; Finlay, I G
2000-09-01
Gastric emptying is delayed in patients with idiopathic slow-transit constipation (ISTC). Gastric emptying was measured before and after colectomy and ileorectal anastomosis in patients with ISTC to determine whether the abnormality persists after operation. Twelve patients undergoing colectomy for severe ISTC had solid-phase gastric emptying measured after an overnight fast. All 12 had an uncomplicated subtotal colectomy and ileorectal anastomosis; 11 had an excellent functional outcome. In ten of these patients gastric emptying was repeated within 3 months of operation. Seven patients (including the remaining two) had the study performed at 1 year. All 12 patients had severely delayed gastric emptying before operation. Gastric emptying remained delayed in the ten patients who underwent an early postoperative gastric emptying study. Six of seven patients assessed at 1 year had improved gastric emptying, of whom four had returned to normal. Functional outcome did not relate to gastric emptying. Patients with ISTC have delayed gastric emptying. In some patients this returns to normal after colectomy, but is persistent in others. This may have implications for our understanding of ISTC.
Measurement of gastric emptying during and between meal intake in free-feeding Lewis rats.
van der Velde, P; Koslowsky, I; Koopmans, H S
1999-02-01
A new scintigraphic measurement technique is described that allows accurate assessment of gastric emptying in between as well as during a number of successive meals. Measurements were made every minute of food intake, gastric nutrient filling, and gastric emptying over a 6 h, 40 min period in conscious, free-feeding, loosely restrained rats. Before receiving access to the food, the animals had been deprived for a period of 31 h. Over the full duration of the experiment, an average rate of gastric emptying of 2.46 +/- 0.18 (SE) kcal/h was established. During most meals, however, the gastric emptying rate was increased so that an average of 26.9 +/- 2.7% of the ingested calories was emptied while the animals were feeding, with an average emptying rate of 0.15 +/- 0.014 kcal/min or 8.88 +/- 0.84 kcal/h. This transient increase in the rate of gastric emptying was followed by a subsequent slowing of gastric emptying after meal termination; in the 10-min postmeal interval, an average emptying rate of 0.96 +/- 0.12 kcal/h was found. Despite these fluctuations during and immediately after meals, a relatively constant rate of caloric emptying is maintained over longer periods. There were no differences between the emptying rate during the first meal when the gastrointestinal tract was still empty, compared with later meals when the gastrointestinal tract had been filled with food. The emptying rate during the 10-min postmeal interval, however, was significantly reduced during later meals. The results suggest that gastric emptying is controlled by different mechanisms during and after the ingestion of food and that these mechanisms remain in effect at various degrees of gastrointestinal filling.
Caridi, Flavia; Vázquez-Calvo, Angela; Sobrino, Francisco; Martín-Acebes, Miguel A
2015-05-01
The picornavirus foot-and-mouth disease virus (FMDV) is the etiological agent of a highly contagious disease that affects important livestock species. The FMDV capsid is highly acid labile, and viral particles lose infectivity due to their disassembly at pH values slightly below neutrality. This acid sensitivity is related to the mechanism of viral uncoating and genome penetration from endosomes. In this study, we have analyzed the molecular basis of FMDV acid-induced disassembly by isolating and characterizing a panel of novel FMDV mutants differing in acid sensitivity. Amino acid replacements altering virion stability were preferentially distributed in two different regions of the capsid: the N terminus of VP1 and the pentameric interface. Even more, the acid labile phenotype induced by a mutation located at the pentameric interface in VP3 could be compensated by introduction of an amino acid substitution in the N terminus of VP1. These results indicate that the acid sensitivity of FMDV can be considered a multifactorial trait and that virion stability is the fine-tuned product of the interaction between residues from different capsid proteins, in particular those located within the N terminus of VP1 or close to the pentameric interface. The viral capsid protects the viral genome from environmental factors and contributes to virus dissemination and infection. Thus, understanding of the molecular mechanisms that modulate capsid stability is of interest for the basic knowledge of the biology of viruses and as a tool to improve the stability of conventional vaccines based on inactivated virions or empty capsids. Using foot-and-mouth disease virus (FMDV), which displays a capsid with extreme acid sensitivity, we have performed a genetic study to identify the molecular determinants involved in capsid stability. A panel of FMDV mutants with differential sensitivity to acidic pH was generated and characterized, and the results showed that two different regions of FMDV capsid contribute to modulating viral particle stability. These results provide new insights into the molecular mechanisms of acid-mediated FMDV uncoating. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Empty sella associated with growth hormone deficiency and polydactyly.
Jurcă, Maria Claudia; Bembea, Marius; Kozma, Kinga; Şandor, Mircea Ioan; Negrean, Rodica Anamaria; Dobjanschi, Luciana; Cuc, Emilia Albiniţa; Petcheşi, Codruţa Diana; Jurcă, Alexandru Daniel
2018-01-01
Empty sella means the absence of the pituitary gland on cranial computed tomography or magnetic resonance imaging. Empty sella syndrome is the pathological variant of the imaging-described empty sella. We present the case of a male Caucasian child, aged four years and two months, for short stature and diagnosed by imaging procedures as empty sella. The cause of short stature was isolated growth hormone (GH) deficiency. Associated he presented left hand postaxial polydactyly. In connection with this particular case, we propose a review of current knowledge in empty sella syndrome. The particularity of reported case consists of association empty sella with GH deficiency and polydactyly. The association of empty sella with polydactyly is not reported yet in the medical literature and is probably coincidental.
Stomach emptiness in fishes: Sources of variation and study design implications
Vinson, M.R.; Angradi, T.R.
2011-01-01
This study summarizes fish stomach content data from 369,000 fish from 402 species in 1,096 collections and reports on the percentage of individuals with empty stomachs. The mean percentage of individuals with empty stomachs among all species, locations, habitats, seasons, regions, and collection methods was 26.4%. Mean percentage of individuals with empty stomachs varied significantly among fish collection gear types, taxonomic orders, trophic groups, feeding behaviors, and habitats, and with species length at maturity. Most of the variation in percentage of individuals with empty stomachs was explained by species length at maturity, fish collection gear type, and two autecological factors: trophic group (piscivore percentage of individuals with empty stomachs > non-piscivore percentage of individuals with empty stomachs) and feeding habitat (water column feeder percentage of individuals with empty stomachs > benthic feeder percentage of individuals with empty stomachs). After accounting for variation with fish length, the percentage of individuals with empty stomachs did not vary with the stomach removal collection method (dissection vs. gastric lavage), feeding time (diurnal or nocturnal), or time of collection (day or night). The percentage of individuals with empty stomachs was similar between fresh and saltwater fish, but differed within finer habitat classifications and appeared to follow a general prey availability or productivity gradient: percentage of individuals with empty stomachs of open ocean collections > estuary collections, lentic > lotic, and pelagic > littoral. Gear type (active or passive) was the most influential factor affecting the occurrence of empty stomachs that can be readily controlled by researchers.
Untangling the origin of viruses and their impact on cellular evolution.
Nasir, Arshan; Sun, Feng-Jie; Kim, Kyung Mo; Caetano-Anollés, Gustavo
2015-04-01
The origin and evolution of viruses remain mysterious. Here, we focus on the distribution of viral replicons in host organisms, their morphological features, and the evolution of highly conserved protein and nucleic acid structures. The apparent inability of RNA viral replicons to infect contemporary akaryotic species suggests an early origin of RNA viruses and their subsequent loss in akaryotes. A census of virion morphotypes reveals that advanced forms were unique to viruses infecting a specific supergroup, while simpler forms were observed in viruses infecting organisms in all forms of cellular life. Results hint toward an ancient origin of viruses from an ancestral virus harboring either filamentous or spherical virions. Finally, phylogenetic trees built from protein domain and tRNA structures in thousands of genomes suggest that viruses evolved via reductive evolution from ancient cells. The analysis presents a complete account of the evolutionary history of cells and viruses and identifies viruses as crucial agents influencing cellular evolution. © 2015 New York Academy of Sciences.
Díaz-Valle, Armando; García-Salcedo, Yardena M; Chávez-Calvillo, Gabriela; Silva-Rosales, Laura; Carrillo-Tripp, Mauricio
2015-12-01
Obtaining pure and soluble viral capsid proteins (CPs) has been a major challenge in the fields of science and technology in recent decades. In many cases, the CPs can self-assemble in the absence of a viral genome, resulting in non-infectious, empty virus-like particles (VLPs) which can be safely handled. The use of VLPs has found great potential in biotechnology and health purposes. In addition, VLPs are a good model system to study protein-protein interactions at the molecular level. In this work, an optimized strategy for the heterologous expression of the Cowpea chlorotic mottle virus (CCMV) CP based in Escherichia coli is described. The method is efficient, inexpensive and it consistently produces higher yields and greater purity levels than those reported so far. Additionally, one of the main advantages of this method is the prevention of the formation of inclusion bodies, thus allowing to directly obtain high amounts of the CP in a soluble and functionally active state with the capacity to readily form VLPs in vitro. The CCMV CP self-assembly pH dependence was also investigated, providing guidelines to easily modulate the process. Copyright © 2015 Elsevier B.V. All rights reserved.
The Unique IR2 Protein of Equine Herpesvirus 1 Negatively Regulates Viral Gene Expression
Kim, Seong K.; Ahn, Byung C.; Albrecht, Randy A.; O'Callaghan, Dennis J.
2006-01-01
The IR2 protein (IR2P) is a truncated form of the immediate-early protein (IEP) lacking the essential acidic transcriptional activation domain (TAD) and serine-rich tract and yet retaining binding domains for DNA and TFIIB and nuclear localization signal (NLS). Analysis of the IR2 promoter indicated that the IR2 promoter was upregulated by the EICP0P. The IR2P was first detected in the nucleus at 5 h postinfection in equine herpesvirus 1 (EHV-1)-infected HeLa and equine NBL6 cells. Transient-transfection assays revealed that (i) the IR2P by itself downregulated EHV-1 early promoters (EICP0, TK, EICP22, and EICP27) in a dose-dependent manner; (ii) the IR2P abrogated the IEP and the EICP27P (UL5) mediated transactivation of viral promoters in a dose-dependent manner; and (iii) the IR2P, like the IEP itself, also downregulated the IE promoter, indicating that the IEP TAD is not necessary to downregulate the IE promoter. In vitro interaction assays revealed that the IR2P interacts with TATA box-binding protein (TBP). The essential domain(s) of the IR2P that mediate negative regulation were mapped to amino acid residues 1 to 706, indicating that the DNA-binding domain and the NLS of the IR2P may be important for the downregulation. In transient-transfection and virus growth assays, the IR2P reduced EHV-1 production by 23-fold compared to virus titers achieved in cells transfected with the empty vector. Overall, these studies suggest that the IR2P downregulates viral gene expression by acting as a dominant-negative protein that blocks IEP-binding to viral promoters and/or squelching the limited supplies of TFIIB and TBP. PMID:16641295
The unique IR2 protein of equine herpesvirus 1 negatively regulates viral gene expression.
Kim, Seong K; Ahn, Byung C; Albrecht, Randy A; O'Callaghan, Dennis J
2006-05-01
The IR2 protein (IR2P) is a truncated form of the immediate-early protein (IEP) lacking the essential acidic transcriptional activation domain (TAD) and serine-rich tract and yet retaining binding domains for DNA and TFIIB and nuclear localization signal (NLS). Analysis of the IR2 promoter indicated that the IR2 promoter was upregulated by the EICP0P. The IR2P was first detected in the nucleus at 5 h postinfection in equine herpesvirus 1 (EHV-1)-infected HeLa and equine NBL6 cells. Transient-transfection assays revealed that (i) the IR2P by itself downregulated EHV-1 early promoters (EICP0, TK, EICP22, and EICP27) in a dose-dependent manner; (ii) the IR2P abrogated the IEP and the EICP27P (UL5) mediated transactivation of viral promoters in a dose-dependent manner; and (iii) the IR2P, like the IEP itself, also downregulated the IE promoter, indicating that the IEP TAD is not necessary to downregulate the IE promoter. In vitro interaction assays revealed that the IR2P interacts with TATA box-binding protein (TBP). The essential domain(s) of the IR2P that mediate negative regulation were mapped to amino acid residues 1 to 706, indicating that the DNA-binding domain and the NLS of the IR2P may be important for the downregulation. In transient-transfection and virus growth assays, the IR2P reduced EHV-1 production by 23-fold compared to virus titers achieved in cells transfected with the empty vector. Overall, these studies suggest that the IR2P downregulates viral gene expression by acting as a dominant-negative protein that blocks IEP-binding to viral promoters and/or squelching the limited supplies of TFIIB and TBP.
Powell, Kim L; Fitzgerald, Xavier; Shallue, Claire; Jovanovska, Valentina; Klugmann, Matthias; Von Jonquieres, Georg; O'Brien, Terence J; Morris, Margaret J
2018-05-01
Neuropeptide Y (NPY) is an important 36 amino acid peptide that is abundantly expressed in the mammalian CNS and is known to be an endogenous modulator of seizure activity, including in rat models of Genetic Generalised Epilepsy (GGE) with absence seizures. Studies have shown that viral-mediated "gene therapy" with overexpression of NPY in the hippocampus can suppress seizures in acquired epilepsy animal models. This study investigated whether NPY gene delivery to the thalamus or somatosensory cortex, using recombinant adeno-associated viral vector (rAAV), could produce sustained seizure suppression in the GAERS model of GGE with absence seizures. Three cohorts of GAERS were injected bilaterally into the thalamus (short term n = 14 and long term n = 8) or the somatosensory cortex (n = 26) with rAAV-NPY or rAAV-empty. EEG recordings were acquired weekly post-treatment and seizure expression was quantified. Anxiety levels were tested using elevated plus maze and open field test. NPY and NPY receptor mRNA and protein expression were evaluated using quantitative PCR, immunohistochemistry and immunofluorescence. Viral overexpression of human NPY in the thalamus and somatosensory cortex in GAERS significantly reduced the time spent in seizure activity and number of seizures, whereas seizure duration was only reduced after thalamic NPY overexpression. Human and rat NPY and rat Y2 receptor mRNA expression was significantly increased in the somatosensory cortex. NPY overexpression in the thalamus was observed in rAAV-NPY treated rats compared to controls in the long term cohort. No effect was observed on anxiety behaviour. We conclude that virally-mediated human NPY overexpression in the thalamus or somatosensory cortex produces sustained anti-epileptic effects in GAERS. NPY gene therapy may represent a novel approach for the treatment of patients with genetic generalised epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.
Borrel, Guillaume; Colombet, Jonathan; Robin, Agnès; Lehours, Anne-Catherine; Prangishvili, David; Sime-Ngando, Télesphore
2012-11-01
Morphological diversity, abundance and community structure of viruses were examined in the deep and anoxic sediments of the volcanic Lake Pavin (France). The sediment core, encompassing 130 years of sedimentation, was subsampled every centimeter. High viral abundances were recorded and correlated to prokaryotic densities. Abundances of viruses and prokaryotes decreased with the depth, contrasting the pattern of virus-to-prokaryote ratio. According to fingerprint analyses, the community structure of viruses, bacteria and archaea gradually changed, and communities of the surface (0-10 cm) could be discriminated from those of the intermediate (11-27 cm) and deep (28-40 cm) sediment layers. Viral morphotypes similar to virions of ubiquitous dsDNA viruses of bacteria were observed. Exceptional morphotypes, previously never reported in freshwater systems, were also detected. Some of these resembled dsDNA viruses of hyperthermophilic and hyperhalophilic archaea. Moreover, unusual types of spherical and cubic virus-like particles (VLPs) were observed. Infected prokaryotic cells were detected in the whole sediment core, and their vertical distribution correlated with both viral and prokaryotic abundances. Pleomorphic ellipsoid VLPs were visible in filamentous cells tentatively identified as representatives of the archaeal genus Methanosaeta, a major group of methane producers on earth.
Borrel, Guillaume; Colombet, Jonathan; Robin, Agnès; Lehours, Anne-Catherine; Prangishvili, David; Sime-Ngando, Télesphore
2012-01-01
Morphological diversity, abundance and community structure of viruses were examined in the deep and anoxic sediments of the volcanic Lake Pavin (France). The sediment core, encompassing 130 years of sedimentation, was subsampled every centimeter. High viral abundances were recorded and correlated to prokaryotic densities. Abundances of viruses and prokaryotes decreased with the depth, contrasting the pattern of virus-to-prokaryote ratio. According to fingerprint analyses, the community structure of viruses, bacteria and archaea gradually changed, and communities of the surface (0–10 cm) could be discriminated from those of the intermediate (11–27 cm) and deep (28–40 cm) sediment layers. Viral morphotypes similar to virions of ubiquitous dsDNA viruses of bacteria were observed. Exceptional morphotypes, previously never reported in freshwater systems, were also detected. Some of these resembled dsDNA viruses of hyperthermophilic and hyperhalophilic archaea. Moreover, unusual types of spherical and cubic virus-like particles (VLPs) were observed. Infected prokaryotic cells were detected in the whole sediment core, and their vertical distribution correlated with both viral and prokaryotic abundances. Pleomorphic ellipsoid VLPs were visible in filamentous cells tentatively identified as representatives of the archaeal genus Methanosaeta, a major group of methane producers on earth. PMID:22648129
Icosahedral plant viral nanoparticles - bioinspired synthesis of nanomaterials/nanostructures.
Narayanan, Kannan Badri; Han, Sung Soo
2017-10-01
Viral nanotechnology utilizes virus nanoparticles (VNPs) and virus-like nanoparticles (VLPs) of plant viruses as highly versatile platforms for materials synthesis and molecular entrapment that can be used in the nanotechnological fields, such as in next-generation nanoelectronics, nanocatalysis, biosensing and optics, and biomedical applications, such as for targeting, therapeutic delivery, and non-invasive in vivo imaging with high specificity and selectivity. In particular, plant virus capsids provide biotemplates for the production of novel nanostructured materials with organic/inorganic moieties incorporated in a very precise and controlled manner. Interestingly, capsid proteins of spherical plant viruses can self-assemble into well-organized icosahedral three-dimensional (3D) nanoscale multivalent architectures with high monodispersity and structural symmetry. Using viral genetic and protein engineering of icosahedral viruses with a variety of sizes, the interior, exterior and the interfaces between coat protein (CP) subunits can be manipulated to fabricate materials with a wide range of desirable properties allowing for biomineralization, encapsulation, infusion, controlled self-assembly, and multivalent ligand display of nanoparticles or molecules for varied applications. In this review, we discuss the various functional nanomaterials/nanostructures developed using the VNPs and VLPs of different icosahedral plant viruses and their nano(bio)technological and nanomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.
Spontaneous curvature as a regulator of the size of virus capsids
NASA Astrophysics Data System (ADS)
Šiber, Antonio; Majdandžić, Antonio
2009-08-01
We investigate the physical reasons underlying the high monodispersity of empty virus capsids assembled in thermodynamical equilibrium in conditions of favorable pH and ionic strength. We propose that the high fidelity of the assembly results from the effective spontaneous curvature of the viral protein assemblies and the corresponding bending rigidity that penalizes curvatures which are larger and smaller from the spontaneous one. On the example of hepatitis B virus, which has been thoroughly studied experimentally in the context of interest to us, we estimate the magnitude of bending rigidity that is needed to suppress the appearance of aberrant capsid structures (˜60kBT) . Our approach also demonstrates that the aberrant capsids that can be classified within the Caspar-Klug framework are in most circumstances likely to be smaller from the regular ones, in agreement with the experimental findings.
What is emptiness? Clarifying the 7th criterion for borderline personality disorder.
Klonsky, E David
2008-08-01
The present study aims to clarify the 7th DSM-IV criterion for Borderline Personality Disorder: "chronic feelings of emptiness." Emptiness has been the subject of little empirical investigation. The relationship of emptiness to boredom and other affect-states is uncertain, and patients and clinicians can find it difficult to generate verbal descriptions of emptiness. In the present study, two sets of analyses address the meaning and clinical implications of feeling empty. First, affect-states that co-occur with emptiness are identified in 45 young adults who exhibit a prominent feature of Borderline Personality Disorder (i.e., self-injury). Second, the relationship of chronic emptiness to key psychiatric variables is examined in a large nonclinical sample (n = 274). Results indicate that emptiness is negligibly related to boredom, is closely related to feeling hopeless, lonely, and isolated, and is a robust predictor of depression and suicidal ideation (but not anxiety or suicide attempts). Findings are consistent with DSM-IV revisions regarding the 7th criterion for Borderline Personality Disorder. In addition, findings suggest that emptiness reflects pathologically low positive affect and significant psychiatric distress.
Nothing to it: Precursors to a Zero Concept in Preschoolers
Merritt, Dustin J.; Brannon, Elizabeth M.
2013-01-01
Do young children understand the numerical value of empty sets prior to developing a concept of symbolic zero? Are empty sets represented as mental magnitudes? In order to investigate these questions, we tested 4-year old children and adults with a numerical ordering task in which the goal was to select two stimuli in ascending numerical order with occasional empty set stimuli. Both children and adults showed distance effects for empty sets.. Children who were unable to order the symbol zero (e.g., 0 < 1), but who successfully ordered countable integers (e.g., 2 < 4) nevertheless showed distance effects with empty sets. These results suggest that empty sets are represented on the same numerical continuum as non-empty sets and that children represent empty sets numerically prior to understanding symbolic zero. PMID:23219980
Gastric emptying abnormal in duodenal ulcer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Holt, S.; Heading, R.C.; Taylor, T.V.
1986-07-01
To investigate the possibility that an abnormality of gastric emptying exists in duodenal ulcer and to determine if such an abnormality persists after ulcer healing, scintigraphic gastric emptying measurements were undertaken in 16 duodenal ulcer patients before, during, and after therapy with cimetidine; in 12 patients with pernicious anemia, and in 12 control subjects. No difference was detected in the rate or pattern of gastric emptying in duodenal ulcer patients before and after ulcer healing with cimetidine compared with controls, but emptying of the solid component of the test meal was more rapid during treatment with the drug. Comparison ofmore » emptying patterns obtained in duodenal ulcer subjects during and after cimetidine treatment with those obtained in pernicious anemia patients and controls revealed a similar relationship that was characterized by a tendency for reduction in the normal differentiation between the emptying of solid and liquid from the stomach. The similarity in emptying patterns in these groups of subjects suggests that gastric emptying of solids may be influenced by changes in the volume of gastric secretion. The failure to detect an abnormality of gastric emptying in duodenal ulcer subjects before and after ulcer healing calls into question the widespread belief that abnormally rapid gastric emptying is a feature with pathogenetic significance in duodenal ulcer disease.« less
Physical characteristics of indigestible solids affect emptying from the fasting human stomach.
Meyer, B; Beglinger, C; Neumayer, M; Stalder, G A
1989-01-01
Gastric emptying of indigestible solids depends on their size. It is not clear whether physical characteristics other than particle size affect emptying of indigestible solids from the fasting human stomach. We studied gastric emptying of three differently shaped particles, (cubes, spheres, rods) of either hard or soft consistency during the fasting state in human volunteers. The shape of indigestible particles did not affect their emptying. The area under the gastric emptying curve (AUC: particles x hour) was for hard cubes 24.7 (2.2), for hard spheres 27.9 (1.6), for hard rods 26.9 (2.7). All soft particles emptied faster than their identically shaped hard counterparts, but there was no difference among the three shapes (AUC for soft cubes: 29.2 (3.0), for soft spheres 32.0 (1.8), for soft rods 34.1 (1.2). If gastric emptying of hard and soft particles was compared independently of their shape, soft particles emptied significantly faster than hard ones: AUC 31.8 (1.2) v 26.5 (1.3) (p less than 0.01). In conclusion, the consistency but not the shape significantly affects gastric emptying. Specific physical characteristics other than size and shape may affect gastric emptying of indigestible particles which may be of importance in the design of drugs. PMID:2599438
Gastric emptying of solid radiopaque markers: studies in healthy subjects and diabetic patients.
Feldman, M; Smith, H J; Simon, T R
1984-10-01
The purpose of these studies was to develop a radiologic method for assessing gastric emptying of an indigestible solid in humans and to apply this technique to the evaluation of patients with diabetes mellitus. Thirty healthy subjects ingested 10 solid radiopaque markers (small pieces of nasogastric tubing) together with a standard meal (donuts and 7-Up). Radiographs of the upper abdomen were obtained hourly for up to 6 h until all markers had emptied from the stomach. Although most of the liquid component of the meal, labeled with 111In, emptied during the first hour (as assessed simultaneously by radionuclide scintigraphy), few radiopaque markers emptied from the stomach during the first 2 h after the meal. Most markers emptied during the fourth postprandial hour, and all 10 markers had emptied by 6 h in 45 of 46 experiments. In contrast, not all of the solid radiopaque markers emptied from the stomach by 6 h in 16 of 26 experiments in patients with diabetes mellitus (p less than 0.001 vs. healthy controls). In some experiments, 99mTc-labeled scrambled eggs were added to the meal so that emptying of this digestible solid, assessed by scintigraphy, could be compared with emptying of liquids and solid radiopaque markers. In healthy subjects, the digestible solid emptied more slowly than the liquid (t 1/2 = 154 +/- 11 min vs. 30 +/- 3 min, p less than 0.001), but emptying of digestible solid was significantly faster than the emptying of the indigestible solid radiopaque markers. In diabetics, emptying rates for the digestible solid and liquid were close to normal (t 1/2 = 178 +/- 5 min and 40 +/- 3 min, respectively), whereas indigestible solid markers were retained in the stomach 6 h after the meal in 50% of the patients. Radiopaque markers proved to be a simple method for measuring gastric emptying of indigestible solids in humans. Using this technique, patients with insulin-dependent diabetes mellitus had a high incidence of abnormally slow gastric emptying of indigestible solids; the method may be a more sensitive indicator of gastric motor dysfunction than radionuclide scintigraphy.
A review of methods for assessment of the rate of gastric emptying in the dog and cat: 1898-2002.
Wyse, C A; McLellan, J; Dickie, A M; Sutton, D G M; Preston, T; Yam, P S
2003-01-01
Gastric emptying is the process by which food is delivered to the small intestine at a rate and in a form that optimizes intestinal absorption of nutrients. The rate of gastric emptying is subject to alteration by physiological, pharmacological, and pathological conditions. Gastric emptying of solids is of greater clinical significance because disordered gastric emptying rarely is detectable in the liquid phase. Imaging techniques have the disadvantage of requiring restraint of the animal and access to expensive equipment. Radiographic methods require administration of test meals that are not similar to food. Scintigraphy is the gold standard method for assessment of gastric emptying but requires administration of a radioisotope. Magnetic resonance imaging has not yet been applied for assessment of gastric emptying in small animals. Ultrasonography is a potentially useful, but subjective, method for assessment of gastric emptying in dogs. Gastric tracer methods require insertion of gastric or intestinal cannulae and are rarely applied outside of the research laboratory. The paracetamol absorption test has been applied for assessment of liquid phase gastric emptying in the dog, but requires IV cannulation. The gastric emptying breath test is a noninvasive method for assessment of gastric emptying that has been applied in dogs and cats. This method can be carried out away from the veterinary hospital, but the effects of physiological and pathological abnormalities on the test are not known. Advances in technology will facilitate the development of reliable methods for assessment of gastric emptying in small animals.
Rao, Vidhya R; Upadhyay, Arun K; Kompella, Uday B
2013-11-28
Empty adenovirus serotype 5 (Ad5) capsids devoid of viral genome were developed as a novel delivery system for nanoparticles, proteins, and nucleic acids. Ad5 capsids of 110 nm diameter undergo an increase in particle size to 1637 nm in 1mM acetic acid at pH4.0 and then shrink to 60 nm, following pH reversal to 7.4. These pH shifts induced reversible changes in capsid zeta potential and secondary structure and irreversible changes in tertiary structure of capsid proteins. Using pH shift dependent changes in capsid size and structure, 20 nm fluorescent nanoparticles, FITC-BSA, and Alexa Fluor® 488 conjugated siRNA were encapsulated with high efficiency in Ad5 capsids, as confirmed by electron microscopy and/or flow cytometry. HEK cell uptake with capsid delivery system was 7.8-, 7.4-, and 2.9-fold greater for nanoparticles, FITC-BSA, and Alexa-siRNA, respectively, when compared to plain solutes. Physical mixtures of capsids and fluorescent solutes exhibited less capsid associated fluorescence intensity and cell uptake. Further, unlike physical mixture, pH shift assembled Ad5 capsids protected siRNA from RNase degradation. Ad5 capsids before and after pH shift exhibited endolysosomal escape. Thus, empty Ad5 capsids can encapsulate a variety of solutes based on pH shift assembly, resulting in enhanced cellular delivery. © 2013. Published by Elsevier B.V. All rights reserved.
Assessment of Gastric Emptying in Patients with Autoimmune Gastritis.
Kalkan, Çağdaş; Soykan, Irfan; Soydal, Çiğdem; Özkan, Elgin; Kalkan, Emra
2016-06-01
Symptoms of patients with autoimmune gastritis are not specific, and some patients may present symptoms suggestive of delayed gastric emptying. This study aims to investigate whether any delay in gastric emptying of solid food exists in patients with autoimmune gastritis and, if so, to identify the factors that might affect delayed gastric emptying. A total of 165 patients (106 women) diagnosed as having autoimmune gastritis were analyzed by means of a gastric emptying test. All patients underwent a standardized scintigraphic gastric emptying study. Patients with delayed gastric emptying and normal gastric emptying tests were then compared by means of factors that might affect gastric emptying. Also 65 patients with functional dyspepsia who had a gastric emptying study constituted the control group. The median gastric emptying T ½ time was 127.43 min (min-max 50-953) for patients with AIG and 81 min (min-max 21-121.6) for functional dyspepsia patients (p < 0.001), and median percent retention at 2 h was 63.8 versus 20.2 (p < 0.001). In multivariate analysis, parameters that affected gastric emptying T ½ time were found as serum gastrin level (OR 1.002, 95 % CI 1.001-1.004, p < 0.001, chronic inflammation (OR 3.689, 95 % CI 1.44-9.39, p < 0.001), and increase in the degree of the atrophy of the gastric mucosa (OR 8.96, 95 % CI 2.98-26.93, p < 0.001). In patients with autoimmune gastritis, gastric emptying is generally delayed. Autoimmune gastritis is an important etiology to explain the finding of delayed gastric emptying on a radionuclide test. This new finding is likely to be relevant to clinicians when evaluating and initiating appropriate medical treatment for patients with autoimmune gastritis manifesting upper gastrointestinal symptoms.
RELATIONSHIP BETWEEN GLYCEMIC CONTROL AND GASTRIC EMPTYING IN POORLY CONTROLLED TYPE 2 DIABETES
Bharucha, Adil E.; Kudva, Yogish; Basu, Ananda; Camilleri, Michael; Low, Phillip A.; Vella, Adrian; Zinsmeister, Alan R.
2014-01-01
Background & Aims Acute hyperglycemia delays gastric emptying in patients with diabetes. However, it is not clear whether improved control of glycemia affects gastric emptying in these patients. We investigated whether overnight and short-term (6 months) improvements in control of glycemia affect gastric emptying. Methods We studied 30 patients with poorly controlled type 2 diabetes (levels of glycated hemoglobin >9%). We measured gastric emptying using the [13C]-spirulina platensis breath test on the patients’ first visit (visit 1), after overnight administration of insulin or saline, 1 week later (visit 2), and 6 months after intensive therapy for diabetes. We also measured fasting and post-prandial plasma levels of C-peptide, GLP1, and amylin, as well as autonomic functions. Results At visit 1, gastric emptying was normal in 10 patients, delayed in 14, and accelerated in 6; 6 patients had gastrointestinal symptoms; vagal dysfunction was associated with delayed gastric emptying (P<.05). Higher fasting blood levels of glucose were associated with shorter half-times of gastric emptying (thalf) at visits 1 (r= −0.46, P=.01) and 2 (r= −0.43, P=.02). Although blood levels of glucose were lower after administration of insulin (132±7 mg/dl) than saline (211±15 mg/dl; P=0.0002), gastric emptying thalf was not lower after administration of insulin, compared with saline. After 6 months of intensive therapy, levels of glycated hemoglobin decreased from 10.6%±0.3% to 9%±0.4% (P=.0003), but gastric emptying thalf did not change (92±8 min before, 92±7 min after). Gastric emptying did not correlate with plasma levels of GLP1 and amylin. Conclusions Two-thirds of patients with poorly-controlled type 2 diabetes have mostly asymptomatic yet abnormal gastric emptying. Higher fasting blood levels of glucose are associated with faster gastric emptying. Overnight and sustained (6 months) improvements in glycemic control do not affect gastric emptying. PMID:25041866
NASA Astrophysics Data System (ADS)
Alkubaisi, Noorah A.; Aref, Nagwa M. A.
2017-02-01
Gold nanoparticles (AuNPs) application melted barley yellow dwarf virus-PAV (BYDV-PAV) spherical nanoparticle capsids. Synergistic therapeutic effects for plant virus resistance were induced by interaction with binding units of prepared AuNPs in a water solution which was characterized and evaluated by zeta sizer, zeta potential and transmission electron microscopy (TEM). The yield of purified nanoparticles of BYDV-PAV was obtained from Hordeum vulgare (Barley) cultivars, local and Giza 121/Justo. It was 0.62 mg/ml from 27.30 g of infected leaves at an A260/A280 ratio. Virus nanoparticle has a spherical shape 30 nm in size by TEM. BYDV-PAV combined with AuNPs to challenge virus function in vivo and in vitro. Dual AuNPs existence in vivo and in vitro affected compacted configuration of viral capsid protein in the interior surface of capsomers, the outer surface, or between the interface of coat protein subunits for 24 and 48 h incubation period in vitro at room temperature. The sizes of AuNPs that had a potentially dramatic deteriorated effect are 3.151 and 31.67 nm with a different intensity of 75.3% for the former and 24.7% for the latter, which enhances optical sensing applications to eliminate virus infectivity. Damages of capsid protein due to AuNPs on the surface of virus subunits caused variable performance in four different types of TEM named puffed, deteriorated and decorated, ruined and vanished. Viral yield showed remarkably high-intensity degree of particle symmetry and uniformity in the local cultivar greater than in Giza 121/Justo cultivar. A high yield of ruined VLPs in the local cultivar than Justo cultivar was noticed. AuNPs indicated complete lysed VLPs and some deteriorated VLPs at 48 h.
Urbain, J L; Penninckx, F; Siegel, J A; Vandenborre, P; Van Cutsem, E; Vandenmaegdenbergh, V; De Roo, M
1990-10-01
The role of the distal stomach in gastric emptying was studied. Ten patients with proximal gastric vagotomy (PV) and 10 age-matched patients with Roux-en-Y gastro-jejunostomy (R-Y) were compared with 10 healthy controls. Gastric emptying of solids and liquids was determined by the use of Tc-99m SC scrambled eggs and In-111 DTPA. In PV, gastric emptying of both solids and liquids was delayed; the prolongation with solids was mainly accounted for by an abnormal lag phase. In R-Y patients, no lag phase was observed, and the solid emptying curve pattern was characterized by early rapid emptying followed by very slow emptying. Both the solid and liquid phases were prolonged. The lag phase is affected by proximal vagotomy and is mainly determined by the distal stomach, which appears to be essential for normal emptying.
Deden, Laura N; Cooiman, Mellody I; Aarts, Edo O; Janssen, Ignace M C; Gotthardt, Martin; Hendrickx, Baudewijn W; Berends, Frits J
2017-11-01
After Roux-en-Y gastric bypass (RYGB), approximately 10% of patients have insufficient weight loss (excess body mass index loss<50%). Gastric pouch emptying may have a role in weight loss. To compare pouch emptying of patients with poor weight loss and patients with successful weight loss after RYGB. A research-intensive nonacademic hospital and center of expertise in bariatric surgery in the Netherlands METHODS: Female patients were included from among patients with the least (poor weight loss group [P-WL]) and the most weight loss (successful weight loss group [S-WL]) in our center 2 years after RYGB. Pouch emptying scintigraphy was performed after ingestion of a radiolabeled solid meal. Emptying curves, intestinal content (IC) at meal completion and after 15, 30, 45, and 60 minutes, half emptying time, and maximal pouch emptying rate were compared. Five individuals were included in P-WL and 5 in S-WL, on average 2.5 ± .3 years after RYGB. Total weight loss was 18 ± 4.1% in P-WL and 44 ± 5.7% in S-WL (P<.001). In P-WL, a fast initial pouch emptying and exponential emptying curve was observed, compared with a slower initial emptying and more linear curve in S-WL. Faster emptying in P-WL was also shown by a larger IC meal (42 ± 18% versus 4.0 ± 3.3%,), IC 15 (76 ± 15% versus 35 ± 22%), and IC 30 (85 ± 12% versus 54 ± 25%), and a greater maximal pouch emptying rate (17 ± 4.7 versus 5.6 ± 3.4%/min) compared with S-WL (P<.05). A linear correlation was found between total weight loss and maximal pouch emptying rate (Pearson R = .82, P = .004). Pouch emptying for solid food was faster in patients with the least weight loss compared with patients with the most weight loss after RYGB. If pouch emptying is an important mechanism in weight loss, altering the pouch outlet may improve poor weight loss management. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
Agoraphobia and Melancholia: Thoughts on Milrod's "Emptiness in Agoraphobia Patients".
Yates, Sheena
2015-08-01
Milrod (2007) identifies persistent emptiness in agoraphobic patients whose symptoms of anxiety and avoidance have remitted. To this important identification, a number of critical considerations may be raised regarding the meanings of emptiness in the psychoanalytic clinic. Milrod's admonishment to distinguish between an emptiness that indicates a deficit in the structure and stability of self-representation, and an emptiness that is strictly defensive, is a case in point. While much of the literature supports an interpretation of emptiness as a defense against overwhelming rage, these patients' assertions and experiences of emptiness can be better explained by the presence of traumatic, unmourned losses. Several explanations are offered as to why agoraphobic patients, in particular, defend unconsciously against mourning. © 2015 by the American Psychoanalytic Association.
Measurement of gastric emptying by intragastric gamma scintigraphy.
Malbert, C H; Mathis, C; Bobillier, E; Laplace, J P; Horowitz, M
1997-09-01
Gastric emptying is usually measured in animals and humans by dilution/sampling or external scintigraphy. These methods are either time consuming or require expensive equipment. The capacity of a miniature gamma counter positioned in the stomach to measure emptying of liquid and solid meals was evaluated. In eight conscious pigs fitted with gastric and duodenal cannulae, gastric emptying of saline (500 mL), dextrose (20%, 500 mL), porridge (300 g) and scrambled eggs (300 g), all labelled with 3.5 MBq 99mTC, was evaluated. When positioned in the antrum the probe was unable to quantify gastric emptying. In contrast, measurements of the fractional emptying of saline over 4-min periods by the probe positioned in the corpus and quantification of radioactivity in the duodenal effluent correlated closely (r = 0.88, P < 0.05). Gastric emptying (50% emptying time) of saline and both solid meals measured by the probe was not significantly different from quantification of the duodenal effluent volume. No difference was observed also for the dextrose meal but only while gastric acid secretion was suppressed by omeprazole. We conclude that an intragastric gamma counter permits measurement of gastric emptying of homogeneous meals provided meal stimulation of gastric secretion was not extensive. This was possible probably by monitoring emptying from the proximal stomach.
Ogata, Makoto; Umemura, Seiichiro; Sugiyama, Naohiro; Kuwano, Natsuki; Koizumi, Ami; Sawada, Tadakazu; Yanase, Michiyo; Takaha, Takeshi; Kadokawa, Jun-Ichi; Usui, Taichi
2016-11-20
A series of multivalent sialoglyco-conjugated nanoparticles were efficiently synthesized by using highly-branched α-glucuronic acid-linked cyclic dextrins (GlcA-HBCD) as a backbone. The sialoglycoside-moieties, with varying degrees of substitution, could be incorporated onto the preformed nanoparticles. These synthesized particles, which are highly soluble in aqueous solution, were shown to have a spherical nanostructure with a diameter of approximately 15nm. The interactions of the sialoglyco-nanoparticles (Neu5Acα2,6LacNAc-GlcA-HBCDs) with human influenza virus strain A/Beijing/262/95 (H1N1) were investigated using a hemagglutination inhibition assay. The sialoglyco-nanoparticle, in which the number of sialic acid substitution is 30, acted as a powerful inhibitor of virus binding activity. We show that both distance and multiplicity of effective ligand-virus formation play important roles in enhancing viral inhibition. Our results indicate that the GlcA-HBCD backbone can be used as a novel spherical nanocluster material for preparing a variety of glyco-nanoparticles to facilitate molecular recognition. Copyright © 2016 Elsevier Ltd. All rights reserved.
Endoscopic Evaluation of Gastric Emptying and Effect of Mosapride Citrate on Gastric Emptying
Jung, In Su; Kim, Jie-Hyun; Lee, Hwal Youn; Lee, Sang In
2010-01-01
Purpose Gastric emptying has been evaluated by scintigraphy in spite of its limitations of time consumption, cost, and danger of radioisotope. Endoscopy is a simple technique, however, its validation for gastric emptying and quantification of food has not yet been investigated. The aim of our study was to assess endoscopic gastric emptying compared with scintigraphy and radiopaque markers (ROMs) studies. We also investigated the effect of a single dose of mosapride on gastric emptying. Materials and Methods Fifteen healthy volunteers underwent scintigraphy. Next day, subjects received a standard solid meal with ROMs and underwent endoscopy and simple abdomen X-ray after 3 hrs. After one week, the same procedure was repeated after ingestion of mosapride (5 mg for group 1, n = 8; 10 mg for group 2, n = 7) 15 min before the meal. Quantification of gastric residue by endoscopy was scored from 0 to 3, and the scores were added up. Results All subjects completed the study without any complication. The gastric emptying rate [T1/2 (min)] was in normal range (65.6 ± 12.6 min). Endoscopic gastric emptying was correlated significantly with gastric clearance of ROMs (r = 0.627, p = 0.012). Endoscopic gastric emptying and gastric clearance of ROMs after administration of mosapride showed significant differences in the 10 mg group (p < 0.05). Conclusion Endoscopy can evaluate gastric emptying safely and simply on an outpatient basis. A 10 mg dose of mosapride enhanced gastric emptying, assessed by both endoscopy and ROMs. PMID:20046511
Yang, Tingting; Chu, Jie; Zhou, Chengchao; Medina, Alexis; Li, Cuicui; Jiang, Shan; Zheng, Wengui; Sun, Liyuan; Liu, Jing
2016-07-05
The aim of this study was to compare the catastrophic health expenditure (CHE) prevalence and its determinants between empty-nest and non-empty-nest elderly households. Shandong province of China. A total of 2761 elderly households are included in the analysis. CHE incidence among elderly households was 44.9%. The CHE incidence of empty-nest singles (59.3%, p=0.000, OR=3.19) and empty-nest couples (52.9%, p=0.000, OR=2.45) are both statistically higher than that of non-empty-nest elderly households (31.4%). An inverse association was observed between CHE incidence and income level in all elderly household types. Factors including 1 or more household elderly members with non-communicable chronic diseases in the past 6 months, 1 or more elderly household members being hospitalised in the past year and lower household income, are significant risk factors for CHE in all 3 household types (p<0.05). Health insurance status was found to be a significant determinant of CHE among empty-nest singles and non-empty-nest households (p<0.05). CHE incidence among elderly households is high in China. Empty-nest households are at higher risk for CHE than non-empty-nest households. Based on these findings, we suggest that special insurance be developed to broaden the coverage of health services and heighten the reimbursement rate for empty-nest elderly in the existing health insurance schemes. Financial and social protection interventions are also essential for identified at-risk subgroups among different types of elderly households. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Yang, Tingting; Chu, Jie; Zhou, Chengchao; Medina, Alexis; Li, Cuicui; Jiang, Shan; Zheng, Wengui; Sun, Liyuan; Liu, Jing
2016-01-01
Objective The aim of this study was to compare the catastrophic health expenditure (CHE) prevalence and its determinants between empty-nest and non-empty-nest elderly households. Setting Shandong province of China. Participants A total of 2761 elderly households are included in the analysis. Results CHE incidence among elderly households was 44.9%. The CHE incidence of empty-nest singles (59.3%, p=0.000, OR=3.19) and empty-nest couples (52.9%, p=0.000, OR=2.45) are both statistically higher than that of non-empty-nest elderly households (31.4%). An inverse association was observed between CHE incidence and income level in all elderly household types. Factors including 1 or more household elderly members with non-communicable chronic diseases in the past 6 months, 1 or more elderly household members being hospitalised in the past year and lower household income, are significant risk factors for CHE in all 3 household types (p<0.05). Health insurance status was found to be a significant determinant of CHE among empty-nest singles and non-empty-nest households (p<0.05). Conclusions CHE incidence among elderly households is high in China. Empty-nest households are at higher risk for CHE than non-empty-nest households. Based on these findings, we suggest that special insurance be developed to broaden the coverage of health services and heighten the reimbursement rate for empty-nest elderly in the existing health insurance schemes. Financial and social protection interventions are also essential for identified at-risk subgroups among different types of elderly households. PMID:27381206
Interaction of packaging motor with the polymerase complex of dsRNA bacteriophage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lisal, Jiri; Kainov, Denis E.; Lam, TuKiet T.
2006-07-20
Many viruses employ molecular motors to package their genomes into preformed empty capsids (procapsids). In dsRNA bacteriophages the packaging motor is a hexameric ATPase P4, which is an integral part of the multisubunit procapsid. Structural and biochemical studies revealed a plausible RNA-translocation mechanism for the isolated hexamer. However, little is known about the structure and regulation of the hexamer within the procapsid. Here we use hydrogen-deuterium exchange and mass spectrometry to delineate the interactions of the P4 hexamer with the bacteriophage phi12 procapsid. P4 associates with the procapsid via its C-terminal face. The interactions also stabilize subunit interfaces within themore » hexamer. The conformation of the virus-bound hexamer is more stable than the hexamer in solution, which is prone to spontaneous ring openings. We propose that the stabilization within the viral capsid increases the packaging processivity and confers selectivity during RNA loading.« less
Delayed gastric emptying of both the liquid and solid components of a meal in chronic liver disease.
Galati, J S; Holdeman, K P; Dalrymple, G V; Harrison, K A; Quigley, E M
1994-05-01
To evaluate gastric emptying in patients with chronic liver disease and portal hypertension. We measured gastric emptying of both the liquid and solid components of a meal in 10 consecutive patients with chronic liver disease and portal hypertension, but free of ascites, and 14 age- and sex-matched healthy controls. In the patients with liver disease, relationships between emptying and liver function were examined. To measure gastric emptying, subjects consumed a test meal that consisted of scrambled eggs labeled with 99mTc-sulfur colloid and 4 oz of water labeled with 111In-diethylene triamine pentacetic acid (DTPA). Patients with liver disease and portal hypertension demonstrated delayed emptying of both the liquid (t1/2, min, mean +/- SE, patients vs. 69.4 +/- 19.4 vs. 31.4 +/- 1.8, p < 0.01) and solid (post-lag phase solid emptying: 141 +/- 32.9 vs. 69.8 +/- 4.6, p < 0.006) components of the meal. We could not identify any correlation between gastric emptying and tests of liver function. Gastric emptying is delayed in patients with liver disease and portal hypertension; this abnormal gastric motor function may contribute to the pathophysiology of foregut complaints in this patient population.
Canine gastric emptying of fiber meals: influence of meal viscosity and antroduodenal motility.
Russell, J; Bass, P
1985-12-01
Dietary fibers such as psyllium and guar gum have been shown to delay the gastric emptying of liquids and solids, presumably due to an increase in meal viscosity. For liquid test meals containing fats, delayed gastric emptying is associated with a reversal of the usual antral-to-duodenal contractile gradient. The present studies were performed to determine whether the gastric emptying of increasingly viscous psyllium and guar gum meals was associated with antroduodenal motility changes. Dogs were surgically fitted with mid-duodenal cannulas for the measurement of gastric emptying. Strain-gauge force transducers were used to monitor antral and duodenal contractile responses to the test meals. Low-viscosity fiber meals emptied from the stomach rapidly (E 1/2 approximately 10 min) compared with the high-viscosity meals (E 1/2 approximately 40 min). None of the test meals stimulated antral or duodenal motility despite differences in gastric emptying time. Other motor parameters such as the time of reappearance and the duration of the burst interval were also unchanged. We conclude a) as test meals' fiber content and viscosity increase, gastric emptying is slowed; and b) viscosity-related delays in gastric emptying are not due to an effect on postprandial antroduodenal motility.
49 CFR 173.29 - Empty packagings.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Empty packagings. 173.29 Section 173.29... SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.29 Empty packagings. (a) General. Except as otherwise provided in this section, an empty packaging containing only the residue of a...
Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian
2016-01-01
This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China. PMID:27618905
Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian
2016-08-27
This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China.
Wang, Weixiong; Graziano, Francesca; Russo, Vittorio; Ulm, Arthur J; De Kee, Daniel; Khismatullin, Damir B
2013-01-01
The endovascular treatment of intracranial aneurysms remains a challenge, especially when the aneurysm is large in size and has irregular, non-spherical geometry. In this paper, we use computational fluid dynamics to simulate blood flow in a vertebro-basilar junction giant aneurysm for the following three cases: (1) an empty aneurysm, (2) an aneurysm filled with platinum coils, and (3) an aneurysm filled with a yield stress fluid material. In the computational model, blood and the coil-filled region are treated as a non-Newtonian fluid and an isotropic porous medium, respectively. The results show that yield stress fluids can be used for aneurysm embolization provided the yield stress value is 20 Pa or higher. Specifically, flow recirculation in the aneurysm and the size of the inflow jet impingement zone on the aneurysm wall are substantially reduced by yield stress fluid treatment. Overall, this study opens up the possibility of using yield stress fluids for effective embolization of large-volume intracranial aneurysms.
Yeoh, Keat-Hor; Shafie, S A; Al-Attab, K A; Zainal, Z A
2018-06-15
In this study, three different methods for high quality solid fuel production were tested and compared experimentally. Oil palm empty fruit bunches, mesocarp fibers, palm kernel shells and rubber seeds shells were treated using thermal (TC), hydrothermal (HTC) and vapothermal (VTC) carbonization. All thermochemical methods were accomplished by using a custom made batch-type reactor. Utilization of novel single reactor equipped with suspended internal container provided efficient operation since both steam generator and raw materials were placed inside the same reactor. Highest energy densification was achieved by VTC process followed by TC and HTC processes. The heating value enhancement in VTC and TC was achieved by the increase in fixed carbon content and reduction in volatile matter. The formation of the spherical components in HTC hydrochar which gave a sharp peak at 340 °C in the DTG curves was suggested as the reason that led to the increment in energy content. Copyright © 2018 Elsevier Ltd. All rights reserved.
Composite microparticles of halloysite clay nanotubes bound by calcium carbonate.
Jin, Yi; Yendluri, Raghuvara; Chen, Bin; Wang, Jingbo; Lvov, Yuri
2016-03-15
Natural halloysite clay nanotubes with 15 nm inner and 75 nm outer diameters have been used as vehicles for sustained release of drugs in composite hollow microparticles "glued" with CaCO3. We used a layer-by layer assembly accomplished alginate binding with Ca(2+) followed by CO2 bubbling to prepare the composite microspheres of CaCO3 and polyelectrolytes (PE) modified halloysite nanotubes (HNTs-PE2/CaCO3) with the diameter of about 5-10 μm. These microparticles have empty spherical structure and abundant pore distributions with maxima at 2.5, 3.9, 6.0 and 13.3 nm, and higher surface area of 82.3 m(2) g(-1) as characterized by SEM and BET test. We loaded drugs in these micro-nano carriers of tight piles of halloysite nanotube with end clogged with CaCO3. The sustained release of Nifedipine drug from HNTs-PE2/CaCO3 composite microspheres was slower than for pristine halloysite nanotubes. Copyright © 2015 Elsevier Inc. All rights reserved.
Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rocha, P; Da Silva, M F A; Wang, Anzhong
2008-11-15
Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent stable gravastars, and in some cases they represent 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in some other cases they collapse until themore » formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both stable gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.« less
TensorCalculator: exploring the evolution of mechanical stress in the CCMV capsid
NASA Astrophysics Data System (ADS)
Kononova, Olga; Maksudov, Farkhad; Marx, Kenneth A.; Barsegov, Valeri
2018-01-01
A new computational methodology for the accurate numerical calculation of the Cauchy stress tensor, stress invariants, principal stress components, von Mises and Tresca tensors is developed. The methodology is based on the atomic stress approach which permits the calculation of stress tensors, widely used in continuum mechanics modeling of materials properties, using the output from the MD simulations of discrete atomic and C_α -based coarse-grained structural models of biological particles. The methodology mapped into the software package TensorCalculator was successfully applied to the empty cowpea chlorotic mottle virus (CCMV) shell to explore the evolution of mechanical stress in this mechanically-tested specific example of a soft virus capsid. We found an inhomogeneous stress distribution in various portions of the CCMV structure and stress transfer from one portion of the virus structure to another, which also points to the importance of entropic effects, often ignored in finite element analysis and elastic network modeling. We formulate a criterion for elastic deformation using the first principal stress components. Furthermore, we show that von Mises and Tresca stress tensors can be used to predict the onset of a viral capsid’s mechanical failure, which leads to total structural collapse. TensorCalculator can be used to study stress evolution and dynamics of defects in viral capsids and other large-size protein assemblies.
Fan, Yi-Chin; Chen, Jo-Mei; Lin, Jen-Wei; Chen, Yi-Ying; Wu, Guan-Hong; Su, Kuan-Hsuan; Chiou, Ming-Tang; Wu, Shang-Rung; Yin, Ji-Hang; Liao, Jiunn-Wang; Chang, Gwong-Jen J; Chiou, Shyan-Song
2018-05-10
Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.
L2, the minor capsid protein of papillomavirus
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Joshua W.; Roden, Richard B.S., E-mail: roden@jhmi.edu; Department of Oncology, The Johns Hopkins University, Baltimore, MD 21287
2013-10-15
The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 ismore » not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. - Highlights: • L2 is the minor antigen of the non-enveloped T=7d icosahedral Papillomavirus capsid. • L2 is a nuclear protein that can traffic to ND-10 and facilitate genome encapsidation. • L2 is critical for infection and must be cleaved by furin. • L2 is a broadly protective vaccine antigen recognized by neutralizing antibodies.« less
Piras, Bryan A; Drury, Jason E; Morton, Christopher L; Spence, Yunyu; Lockey, Timothy D; Nathwani, Amit C; Davidoff, Andrew M; Meagher, Michael M
2016-01-01
With clinical trials ongoing, efficient clinical production of adeno-associated virus (AAV) to treat large numbers of patients remains a challenge. We compared distribution of AAV8 packaged with Factor VIII (FVIII) in cell culture media and lysates on days 3, 5, 6, and 7 post-transfection and found increasing viral production through day 6, with the proportion of viral particles in the media increasing from 76% at day 3 to 94% by day 7. Compared to FVIII, AAV8 packaged with Factor IX and Protective Protein/Cathepsin A vectors demonstrated a greater shift from lysate towards media from day 3 to 6, implying that particle distribution is dependent on recombinant vector. Larger-scale productions showed that the ratio of full-to-empty AAV particles is similar in media and lysate, and that AAV harvested on day 6 post-transfection provides equivalent function in mice compared to AAV harvested on day 3. This demonstrates that AAV8 production can be optimized by prolonging the duration of culture post-transfection, and simplified by allowing harvest of media only, with disposal of cells that contain 10% or less of total vector yield. Additionally, the difference in particle distribution with different expression cassettes implies a recombinant vector-dependent processing mechanism which should be taken into account during process development. PMID:27069949
14 CFR 223.24 - Transportation of empty mail bags.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Transportation of empty mail bags. 223.24...
14 CFR 223.24 - Transportation of empty mail bags.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transportation of empty mail bags. 223.24...
14 CFR 223.24 - Transportation of empty mail bags.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transportation of empty mail bags. 223.24...
The stomach, cholecystokinin, and satiety.
McHugh, P R; Moran, T H
1986-04-01
The stomach of the rhesus monkey empties liquids in a fashion that varies with the character of the solutions. Physiological saline empties exponentially. Glucose solutions empty biphasically--rapidly for the first minutes, then slowly and proportionately to glucose concentration to deliver glucose calories through the pylorus at a regulated rate (0.4 kcal/min). This prolonged and regulated second phase of gastric emptying depends on intestinal inhibition of the stomach. Cholecystokinin (CCK), a hormone released by food in the intestine, is an inhibitor of gastric emptying. In vitro receptor autoradiography demonstrates CCK receptors to be clustered on the circular muscle of the pylorus. Exogenous CCK, in doses that inhibit gastric emptying, will reduce food intake only if combined with an infusion of saline in the stomach. These observations indicate how gastric distension can be a means for provoking satiety. The variably sustained distension produced by the stomach's slow, calorically regulated emptying could prolong intermeal intervals and thus permit high-calorie meals to inhibit further caloric intake over time. CCK, by directly inhibiting gastric emptying during a meal, could promote gastric distension and so restrict the duration and size of individual meals.
Nouri, Mohammad; Constable, Peter D
2007-12-01
To determine the effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves. 8 male Holstein-Friesian calves < 35 days old. Calves received each of 4 treatments in random order (2 mL of saline [0.9% NaCl] solution, IM [control treatment]; erythromycin, 8.8 mg/kg, IM; tilmicosin, 10 mg/kg, SC; and tylosin, 17.6 mg/kg, IM). Calves were fed 2 L of milk replacer containing acetaminophen (50 mg/kg) 30 minutes later. Jugular venous blood samples and transabdominal ultrasonographic abomasal dimensions were obtained periodically after suckling. Abomasal emptying rate was assessed on the basis of the time to maximal plasma acetaminophen concentration and ultrasonographic determination of the halftime of abomasal emptying. One-tailed Dunnett post tests were conducted whenever the F value for group was significant. Emptying rate was faster for erythromycin, tilimicosin, and tylosin than for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. Ultrasonography indicated that the half-time of abomasal emptying was significantly shorter for erythromycin than for the control treatment. Tylosin and tilmicosin accelerated the abomasal emptying rate, but not significantly, relative to the emptying rate for the control treatment. Administration of erythromycin, tilmicosin, and tylosin at the label dosage increased abomasal emptying rate in calves. The clinical importance of an increase in abomasal emptying rate in cattle remains to be determined.
Relation between gastric emptying rate and energy intake in children compared with adults.
Maes, B D; Ghoos, Y F; Geypens, B J; Hiele, M I; Rutgeerts, P J
1995-01-01
Measurement of gastric emptying rate of solids in children is difficult because the available methods are either invasive or induce a substantial radiation burden. In this study the newly developed 13C octanoic acid breath test was used to examine the gastric emptying rate of solids and milk in healthy children and to compare gastric emptying in children and adults. Fifteen healthy children and three groups of nine healthy adults were studied, using three different test meals labelled with 50 mg of 13C octanoic acid: a low caloric pancake (150 kcal), a high caloric pancake (250 kcal), and 210 ml of milk (134 kcal). Breath samples were taken before and at regular intervals after ingestion of the test meal, and analysed by isotope ratio mass spectrometry. The gastric emptying parameters were derived from the 13CO2 excretion curves by non-linear regression analysis. No significant difference was found between children and adults in the emptying rate of the low caloric solid test meal. In children as well as in adults, increasing the energy content of the solid meal resulted in a significantly slower emptying rate. The milk test meal, however, was emptied at a faster rate in adults and at slower rate in children compared with the low caloric solid test meal. Moreover, the emptying rate of milk in children was significantly slower than in adults. In conclusion, a similar gastric emptying rate of solids but a slower emptying of full cream milk was shown in children of school age compared with adults, using the non-radioactive 13C octanoic acid breath test. PMID:7883214
Efficient Capsid Antigen Presentation From Adeno-Associated Virus Empty Virions In Vivo.
Pei, Xiaolei; Earley, Lauriel Freya; He, Yi; Chen, Xiaojing; Hall, Nikita Elexa; Samulski, Richard Jude; Li, Chengwen
2018-01-01
Adeno-associated virus (AAV) vectors have been successfully applied in clinical trials for hemophilic patients. Although promising, the clinical results suggest that the capsid-specific CD8+T cell response has a negative effect on therapeutic success. In an in vitro analysis using an engineered AAV virus carrying immune-dominant SIINFEKL peptide in the capsid backbone, we have previously demonstrated that capsid antigen presentation from full (genome containing) AAV capsids requires endosome escape and is proteasome dependent and that no capsid antigen presentation is induced from empty virions. In the present study, we examined capsid antigen presentation from administration of empty virions in animal models. In wild-type mice, similar to AAV full particles, capsid antigen presentation from AAV empty virion infection was dose dependent, and the kinetics studies showed that antigen presentation was detected from 2 to 40 days after AAV empty virion administration. In the transporter associated with antigen processing 1 deficient (TAP-/-) mice, capsid antigen presentation was inhibited from both AAV full and empty virions, but higher inhibition was achieved from AAV full particle administration than that from empty virions. This indicates that the pathway of capsid antigen presentation from AAV transduction is dependent on proteasome-mediated degradation of AAV capsids (mainly for full particles) and that the endosomal pathway may also play a role in antigen presentation from empty particles but not full virions. The capsid antigen presentation efficiency from AAV preparations was positively correlated with the amount of empty virions contaminated with full particles. Collectively, the results indicate that contamination of AAV empty virions induces efficient antigen presentation in vivo and the mechanism of capsid antigen presentation from empty virions involves both endosomal and proteasomal pathways. The elucidation of capsid antigen presentation from AAV empty virions may allow us to rationally design effective strategies to prevent elimination of AAV transduced target cells by capsid specific CD8+ T cells.
Efficient Capsid Antigen Presentation From Adeno-Associated Virus Empty Virions In Vivo
Pei, Xiaolei; Earley, Lauriel Freya; He, Yi; Chen, Xiaojing; Hall, Nikita Elexa; Samulski, Richard Jude; Li, Chengwen
2018-01-01
Adeno-associated virus (AAV) vectors have been successfully applied in clinical trials for hemophilic patients. Although promising, the clinical results suggest that the capsid-specific CD8+T cell response has a negative effect on therapeutic success. In an in vitro analysis using an engineered AAV virus carrying immune-dominant SIINFEKL peptide in the capsid backbone, we have previously demonstrated that capsid antigen presentation from full (genome containing) AAV capsids requires endosome escape and is proteasome dependent and that no capsid antigen presentation is induced from empty virions. In the present study, we examined capsid antigen presentation from administration of empty virions in animal models. In wild-type mice, similar to AAV full particles, capsid antigen presentation from AAV empty virion infection was dose dependent, and the kinetics studies showed that antigen presentation was detected from 2 to 40 days after AAV empty virion administration. In the transporter associated with antigen processing 1 deficient (TAP−/−) mice, capsid antigen presentation was inhibited from both AAV full and empty virions, but higher inhibition was achieved from AAV full particle administration than that from empty virions. This indicates that the pathway of capsid antigen presentation from AAV transduction is dependent on proteasome-mediated degradation of AAV capsids (mainly for full particles) and that the endosomal pathway may also play a role in antigen presentation from empty particles but not full virions. The capsid antigen presentation efficiency from AAV preparations was positively correlated with the amount of empty virions contaminated with full particles. Collectively, the results indicate that contamination of AAV empty virions induces efficient antigen presentation in vivo and the mechanism of capsid antigen presentation from empty virions involves both endosomal and proteasomal pathways. The elucidation of capsid antigen presentation from AAV empty virions may allow us to rationally design effective strategies to prevent elimination of AAV transduced target cells by capsid specific CD8+ T cells. PMID:29725339
Gender Difference of Gastric Emptying in Healthy Volunteers and Patients with Functional Dyspepsia.
Mori, Hideki; Suzuki, Hidekazu; Matsuzaki, Juntaro; Taniguchi, Kanami; Shimizu, Toshiyuki; Yamane, Tsuyoshi; Masaoka, Tatsuhiro; Kanai, Takanori
2017-01-01
Delayed gastric emptying is one of the reasons why functional dyspepsia (FD) occurs. The 13C-acetate breath test is widely used to evaluate gastric emptying. Nevertheless, the standard value of 13C-acetate breath test has not taken into account the gender difference of gastric emptying among healthy individuals. The main aim of this study was to readjust the standard value of 13C-acetate breath test in the light of gender differences. In addition, we clarified the prevalence and clinical characteristics of delayed gastric emptying in patients with FD using the modified standard values of 13C-acetate breath test. Fifty-two healthy individuals and 126 patients with patients with FD were enrolled. Gastric emptying was evaluated by the 13C-acetate breath test. The cut-off points of Tmax for the diagnosis of delayed gastric emptying were determined on the basis of results from healthy individuals making a distinction of genders. Gastroesophageal reflux symptoms, dyspeptic symptoms, scores of anxiety and depression, age, body mass index (BMI), smoking and alcohol consumption were compared between the delayed gastric emptying group and the non-delayed gastric emptying group. Since gastric emptying was delayed in healthy women compared with that in healthy men (Tmax, 53.6 ± 19.3 vs. 42.7 ± 16.9 min, p = 0.04), we set the cut-off points of Tmax at 60 min in men and at 75 min in women. In patients with FD, the prevalence of delayed gastric emptying was not different between men and women with the modified standard values of 13C-acetate breath test. (31.0 vs. 27.4%, p = 0.68). BMI was lower in the delayed gastric emptying group than in the non-delayed group among the male patients. Reflux symptoms were more severe in delayed gastric emptying group than in the non-delayed group among the female patients. The standard values of 13C-acetate breath test should be modified bearing the gender difference in mind. It provides us more appropriate information to understand the mechanisms of FD. © 2016 S. Karger AG, Basel.
Shao, Qiang; Xu, Wenpin; Yan, Li; Liu, Jinhua; Rui, Lei; Xiao, Xiao; Yu, Xiaoxue; Lu, Yanan; Li, Zandong
2014-10-13
The avian influenza (AI) H9N2 virus and IBDV are two major problems in the poultry industry. They have been prevalent among domestic poultry in Asia for many years and have caused considerable economic losses. Retinoic-acid-induced gene I (RIG-I) is a cytoplasmic sensor of dsRNA and ssRNA. It can detect Encephalomyocarditis virus (EMCV) and vesicular stomatitis virus (VSV) in human cells, influenza virus in duck leads to production of IFN-β and IFN-stimulated antiviral genes and reductions in the replication of RNA virus. Chickens, which lack RIG-I, are more sensitive to influenza virus than ducks. However, little is known about the roles of duck RIG-I (dRIG-I) in the detection of IBDV and AI H9N2 in chicken cells DF-1. The purpose of this study was to examine the function of dRIG-I in the recognition of IBDV Ts strain and H9N2 A/Chicken/Shandong/ZB/2007(ZB07) and in the induction of antiviral gene expression to gain an understanding of antiviral ability of dRIG-I in chicken cells against dsRNA virus IBDV and ssRNA virus ZB07. After challenge with the IBDV Ts strain and ZB07 the expression levels of Type I IFN (IFN-β and IFN-α) and IFN-induced antiviral genes (Mx and PKR) were significantly up-regulated in dRIG-I-transfected DF-1cells compared with the empty-vector-transfected control. dRIG-I knockdown experiments further proved that dRIG-I is essential to sensing IBDV and ZB07 in duck embryo fibroblasts (DEF). Growth curves showed that dRIG-I repressed the replication of IBDV and almost blunted the growth of ZB07 in DF-1. Apoptosis analysis revealed that dRIG-I increase the number of the survival cells after IBDV Ts strain or ZB07 infection relative to the empty-vector-transfected control. These results indicate that dRIG-I can up-regulates type I IFN and reduce viral gene expression and viral replication and protect chicken cells from virus-induced apoptosis during ZB07 and IBDV infection. Copyright © 2014 Elsevier B.V. All rights reserved.
Effect of solid-meal caloric content on gastric emptying kinetics of solids and liquids.
Urbain, J L; Siegel, J A; Mortelmans, L; van Cutsem, E; van den Maegdenbergh, V; de Roo, M
1989-08-01
In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread, 111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dual-headed gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.
Uchida, Masayuki; Kobayashi, Orie; Shimizu, Kimiko
2017-01-01
Background This study aimed to evaluate the effects of the position of an acetic acid-induced gastric ulcer and the effects of prokinetic drugs on gastric emptying. Materials and Methods Male Sprague-Dawley rats were used in this study. Acetic acid ulcers were induced either in the region between the fundus and pylorus on the anterior wall of the stomach or in the glandular region on the greater curvature of the stomach to determine whether there were regional differences in the effect of the ulcers. Gastric emptying was evaluated with a breath test using [1- 13 C] acetic acid. In addition, the effects of the prokinetic drugs, metoclopramide and mosapride, on gastric emptying were also evaluated. Results Acetic acid induced ulcers in the region between the fundus and pylorus on the anterior wall of the stomach significantly delayed gastric emptying as compared with control rats, but not the acetic acid induced ulcers in the glandular region on the greater curvature of the stomach. Metoclopramide and mosapride did not improve the delayed gastric emptying even at doses that enhanced gastric emptying in normal rats. Conclusion These findings show that gastric emptying is influenced by the position of the ulcer and the region between the fundus and pylorus on the anterior wall plays an important role in gastric emptying. Moreover, it was found that metoclopramide and mosapride do not improve the delayed gastric emptying caused by acetic acid ulcers induced on the anterior wall in the region between the fundus and pylorus.
Uchida, Masayuki; Kobayashi, Orie; Shimizu, Kimiko
2017-01-01
Abstract Background This study aimed to evaluate the effects of the position of an acetic acid-induced gastric ulcer and the effects of prokinetic drugs on gastric emptying. Materials and Methods Male Sprague-Dawley rats were used in this study. Acetic acid ulcers were induced either in the region between the fundus and pylorus on the anterior wall of the stomach or in the glandular region on the greater curvature of the stomach to determine whether there were regional differences in the effect of the ulcers. Gastric emptying was evaluated with a breath test using [1-13C] acetic acid. In addition, the effects of the prokinetic drugs, metoclopramide and mosapride, on gastric emptying were also evaluated. Results Acetic acid induced ulcers in the region between the fundus and pylorus on the anterior wall of the stomach significantly delayed gastric emptying as compared with control rats, but not the acetic acid induced ulcers in the glandular region on the greater curvature of the stomach. Metoclopramide and mosapride did not improve the delayed gastric emptying even at doses that enhanced gastric emptying in normal rats. Conclusion These findings show that gastric emptying is influenced by the position of the ulcer and the region between the fundus and pylorus on the anterior wall plays an important role in gastric emptying. Moreover, it was found that metoclopramide and mosapride do not improve the delayed gastric emptying caused by acetic acid ulcers induced on the anterior wall in the region between the fundus and pylorus. PMID:28652516
Novel method to assess gastric emptying in humans: the Pellet Gastric Emptying Test
NASA Technical Reports Server (NTRS)
Choe, S. Y.; Neudeck, B. L.; Welage, L. S.; Amidon, G. E.; Barnett, J. L.; Amidon, G. L.
2001-01-01
To further validate the Pellet Gastric Emptying Test (PGET) as a marker of gastric emptying, a randomized, four-way crossover study was conducted with 12 healthy subjects. The study consisted of oral co-administration of enteric coated caffeine (CAFF) and acetaminophen (APAP) pellets in four treatment phases: Same Size (100 kcal), Fasted, Small Liquid Meal (100 kcal), and Standard Meal (847 kcal). The time of first appearance of measurable drug marker in plasma, t(initial), was taken as the emptying time for the markers. Co-administration of same size enteric coated pellets of CAFF and APAP (0.7 mm in diameter) revealed no statistically significant differences in t(initial) values indicating that emptying was dependent only on size and not on chemical make-up of the pellets. Co-administration of different size pellets indicated that the smaller 0.7-mm diameter (CAFF) pellets were emptied and absorbed significantly earlier than the larger 3.6-mm diameter (APAP) pellets with both the Small Liquid Meal (by 35 min) and the Standard Meal (by 33 min) (P<0.05). The differences in emptying of the pellets were not significant in the Fasted Phase. The results suggest that the pellet gastric emptying test could prove useful in monitoring changes in transit times in the fasted and fed states and their impact on drug absorption.
Calories and gastric emptying: a regulatory capacity with implications for feeding.
McHugh, P R; Moran, T H
1979-05-01
Gastric emptying in four unanesthetized male Macaca mulatta was studied with the serial test meal method of Hunt and Spurrell. Liquid meals were infused into the stomach through a chronic indwelling Silastic cannula. Saline meals empty rapidly and exponentially. Doubling the volume of saline from 150 to 300 ml increased the emptying rate so that the half-life remained unchanged (15 min). The 150-ml glucose meals (0.05, 0.125, and 0.25 g/ml) emptied more slowly than saline, progressively more slowly with increasing concentrations (0.05--1.8, 0.125--0.78, and 0.25--0.37 ml/min) and linearly through most of their course. Doubling the volume of 0.125 g/ml-glucose meal did not change the rate of emptying. Converting grams of glucose to their caloric content, the emptying rate in kcal/min becomes constant (approx 0.4 kcal/min) in this range of concentrations. Isocaloric casein hydrolysate and medium-chain triglyceride oil meals at 0.5 kcal/ml empty at the same rate as glucose. The precision of this regulation is sufficient to give it a role in preabsorptive satiety and the control of caloric intake.
Spatial games with cyclic interactions: the response of empty sites
NASA Astrophysics Data System (ADS)
Brown, Bart; Pleimling, Michel
2015-03-01
Predator-prey models of the May-Leonard family employ empty sites in a spatial setting as an intermediate step in the reproduction process. This requirement makes the number and arrangement of empty sites important to the formation of space-time patterns. We study the density of empty sites in a stochastic predator-prey model in which the species compete in a cyclic way in two dimensions. In some cases systems of this type quickly form domains of neutral species after which all predation, and therefore, reproduction occur near the interface of competing domains. Using Monte Carlo simulations we investigate the relationship of this density of empty sites to the time-dependent domain length. We further explore the dynamics by introducing perturbations to the interaction rates of the system after which we measure the perturbed density, i.e. the response of empty sites, as the system relaxes. A dynamical scaling behavior is observed in the response of empty sites. This work is supported by the US National Science Foundation through Grant DMR-1205309.
Asano, Teita; Aida, Shuji; Suemasu, Shintaro; Tahara, Kayoko; Tanaka, Ken-ichiro; Mizushima, Tohru
2015-01-01
Delayed gastric emptying and impaired gastric accommodation (decreased gastric compliance) play important roles in functional dyspepsia (FD). Here we screen for a clinically used drug with an ability to improve delayed gastric emptying in rats. Oral administration of aldioxa (dihydroxyaluminum allantoinate) partially improved clonidine- or restraint stress-induced delayed gastric emptying. Administration of allantoin, but not aluminium hydroxide, restored the gastric emptying. Both aldioxa and allantoin inhibited clonidine binding to the α-2 adrenergic receptor, suggesting that antagonistic activity of the allantoin moiety of aldioxa on this receptor is involved in the restoration of gastric emptying activity. Aldioxa or aluminium hydroxide but not allantoin restored gastric compliance with restraint stress, suggesting that aluminium hydroxide moiety is involved in this restoration. We propose that aldioxa is a candidate drug for FD, because its safety in humans has already been confirmed and its ameliorating effect on both of delayed gastric emptying and impaired gastric compliance are confirmed here. PMID:26620883
How often do fishes "run on empty"?
Arrington, D.A.; Winemiller, K.O.; Loftus, W.F.; Akin, S.
2002-01-01
We used a large data set of African, Neotropical, and North American fishes to examine the frequency with which fishes have empty stomachs (nspecies = 254; nindividuals = 36875). Mean percentage of empty stomachs was low across all fishes (16.2 ?? 1.2%) but varied from 0% to 79.4% among individual species. Nocturnal fishes had empty stomachs more frequently than diurnal fishes. Trophic classification was strongly associated with the percentage of empty stomachs, a pattern also revealed from an intraspecific analysis. Fishes appear to adjust their feeding intervals relative to the energy density, conversion efficiency, and particle size of their food. Piscivorous fishes seem to be the only trophic group that regularly experience long periods of empty stomachs, with species that consume prey whole and those that provide extended parental care having the highest proportions of empty stomachs. Activity patterns and life histories of some piscivorous species probably have evolved in partial response to energetic benefits of large, energy-rich food resources.
French, S J; Read, N W
1994-01-01
To determine whether the satiating effects of fiber are due to delaying gastric emptying or slowing absorption of meals, 3% guar gum was added to high- and low-fat soups and gastric emptying rate, hunger, and satiety were measured in eight male volunteers. Guar gum delayed the emptying of the low-fat soup but the small delays in the return of hunger and decline of fullness were significantly correlated with the gastric emptying, suggesting mediation by gastric mechanoreceptors. The high-fat soup also emptied more slowly but this had no effect on the return of hunger or the decline in fullness. The delays in the return of hunger and decline of fullness were far greater when guar gum was added to the fatty soup; these delays were not correlated with the small additional delay in gastric emptying. This is more compatible with slowed absorption and prolonged contact of nutrients with intestinal chemoreceptors.
The effects of cholelithiasis and cholecystectomy on gastric emptying.
Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y
In this clinical study, four groups, each consisting of 12 patients are established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy. 1. group: healthy people, 2. group: patients with dyspeptic cholelithiasis, 3. group: patients who have no dyspepsia after cholecystectomy, 4. group: patients whose dyspepsia is continued after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulfur colloid bound with scrambled eggs. Gastric emptying delayed in second (p < 0.001) and fourth (p < 0.005) groups postprandially and not differed in the third group (p > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy have a close relation with delay in gastric emptying.
Effects of cholelithiasis and cholecystectomy on gastric emptying.
Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y
1994-06-01
In this prospective, clinical study, four groups, each consisting of 12 patients were established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy: group 1--healthy people; group 2--patients with dyspeptic cholelithiasis; group 3--patients with no dyspepsia after cholecystectomy; group 4--patients with dyspepsia after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulphur colloid bound with scrambled eggs. Gastric emptying delayed in groups 2 (P < 0.001) and 4 (P < 0.005) postprandially and did not differ in the group 3 (P > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy, has a close relation with delay in gastric emptying.
Coarse-grained Simulations of Viral Assembly
NASA Astrophysics Data System (ADS)
Elrad, Oren M.
2011-12-01
The formation of viral capsids is a marvel of natural engineering and design. A large number (from 60 to thousands) of protein subunits assemble into complete, reproducible structures under a variety of conditions while avoiding kinetic and thermodynamic traps. Small single-stranded RNA viruses not only assemble their coat proteins in this fashion but also package their genome during the self-assembly process. Recent experiments have shown that the coat proteins are competent to assemble not merely around their own genomes but heterologous RNA, synthetic polyanions and even functionalized gold nanoparticles. Remarkably these viruses can even assemble around cargo not commensurate with their native state by adopting different morphologies. Understanding the properties that confer such exquisite precision and flexibility to the assembly process could aid biomedical research in the search for novel antiviral remedies, drug-delivery vehicles and contrast agents used in bioimaging. At the same time, viral assembly provides an excellent model system for the development of a statistical mechanical understanding of biological self-assembly, in the hopes of that we will identify some universal principles that underly such processes. This work consists of computational studies using coarse-grained representations of viral coat proteins and their cargoes. We find the relative strength of protein-cargo and protein-protein interactions has a profound effect on the assembly pathway, in some cases leading to assembly mechanisms that are markedly different from those found in previous work on the assembly of empty capsids. In the case of polymeric cargo, we find the first evidence for a previously theorized mechanism in which the polymer actively participates in recruiting free subunits to the assembly process through cooperative polymer-protein motions. We find that successful assembly is non-monotonic in protein-cargo affinity, such affinity can be detrimental to assembly if it becomes strong enough to stabilize frustrated intermediates that are incompatible with the ground state structure. In cases where the subunits are capable of assembly into different morphologies, we find that maintaining the precise spatial arrangement of subunits seen in the crystal structure is possible even if non-native interactions are disfavored by as little as the thermal energy.
A Spectroscopic and Photometric Study of the Planetary Nebulae Kn 61 and Pa 5
NASA Astrophysics Data System (ADS)
García-Díaz, Ma. T.; González-Buitrago, D.; López, J. A.; Zharikov, S.; Tovmassian, G.; Borisov, N.; Valyavin, G.
2014-09-01
We present the first morpho-kinematical analysis of the planetary nebulae Kn 61 and Pa 5 and explore the nature of their central stars. Our analysis is based on high-resolution and medium-resolution spectroscopic observations, deep narrow-band imaging, and integral photometry. This material allows us to identify the morphological components and study their kinematics. The direct images and spectra indicate an absence of the characteristic [N II] and [S II] emission lines in both nebulae. The nebular spectrum of Kn 61 suggests a hydrogen deficient planetary nebula and the stellar spectrum of the central star reveals a hydrogen-deficient PG 1159-type star. The [O III] position velocity diagram reveals that Kn 61 is a closed, empty, spherical shell with a thin border and a filamentary surface expanding at 67.6 km s-1 and the shell is currently not expanding isotropically. We derived a kinematic age of ~1.6 × 104 yr for an assumed distance of 4 kpc. A photometric period of ~5.7(±0.4) days has been detected for Kn 61, indicating the presence of a possible binary system at its core. A possible link between filamentary spherical shells and PG 1159-type stars is noted. The morphology of Pa 5 is dominated by an equatorial toroid and faint polar extensions. The equatorial region of this planetary nebula is expanding at 45.2 km s-1. The stellar spectrum corresponds to a very hot star and is dominated by a steep blue rising continuum and He II, Balmer, and Ca II photospheric lines.
PML nuclear bodies: from architecture to function.
Lallemand-Breitenbach, Valérie; de Thé, Hugues
2018-06-01
PML nuclear bodies are nucleated by the PML protein, which polymerizes into spherical shells where it concentrates many unrelated partner proteins. Emerging data has connected PML bodies to post-translational control, notably conjugation by SUMOs. High concentrations of SUMO-bound proteins were proposed to condense into liquid-like droplets and such phase transition may occur within NBs. Many stress pathways modulate NB formation and recent findings have directly implicated PML in oxidative stress response in vivo. PML may also undergo SUMO-dependent ubiquitination/degradation. We highlight recent advances linking PML to partner degradation and other adaptative post-translational modifications in the context of chromatin remodeling, telomere biology, senescence or viral infections. Copyright © 2018. Published by Elsevier Ltd.
Do calories or osmolality determine gastric emptying
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shafer, R.B.; Levine, A.S.; Marlette, J.M.
1984-01-01
Recent animal studies suggest that gastric emptying is dependent on the caloric and osmotic content of the ingested food. These studies have involved intubation with infusion of liquid meals into the stomach. Scintigraphic methods, which are non-invasive and do not alter normal physiology, are now available for precise quantitation of gastric emptying. To study the role of calories and osmolality on gastric emptying, the authors employed a standardized /sup 99m/Tc-scrambled egg meal washed with 50 cc tap water in 10 normal human volunteers. A variety of simple and complex sugars, non-absorbable complex carbohydrate (polycose), medium chain fatty acid (MCFA) andmore » gluten were dissolved in water and ingested with the test meal. Each subject acted as his own control. Coefficient of variation in control tests in each subject 12 weeks apart was 9.9%. Results showed that incremental glucose (25-66 gm) produced a linear increase in gastric emptying (T/2 control 50 +- 3, 25 gm 60 +- 3, 50 gm 79 +- 3 and 66 gm 102 +- 3 minutes). 25 gm fructose (T/2 59 +- 3 minutes) and 25 gm polycose (T/2 59 +- 3 minutes) had similar effects to glucose. 25 gm sucrose and 25 gm gluten did not significantly differ from controls. MCFA had an effect similar to 50 gm glucose - suggesting that calories are important in gastric emptying. However, 25 gm xylose markedly prolonged gastric emptying to 80 +- 5 minutes. The rank order for osmolality for substances tested MCFA = gluten < polycose < polycose < fructose < sucrose = glucose < xylose defined no relationship to gastric emptying. The authors' results suggest that neither calories nor osmolality alone determine gastric emptying. A specific food does not necessarily have the same effect on gastric emptying in different individuals.« less
Zhai, Yujia; Yi, Huaiming; Shen, Wei; Xiao, Yuanyuan; Fan, Haixiao; He, Fan; Li, Fudong; Wang, Xinyi; Shang, Xiaopeng; Lin, Junfen
2015-11-15
Empty nest has been becoming the main family pattern among old people, and influencing the traditional family providing for the aged in China. This study aimed to investigate the association of empty nest with depressive symptom in a Chinese elderly population. Our study was based on the baseline investigation of Zhejiang Major Public Health Surveillance which was conducted in 2014. The final analyzed sample consisted of 9215 participants aged no less than 60 years. Subjects completed a questionnaire including demographic characteristics, living arrangements, behavioral risk factors, health status, subjective assessments, and Patient Health Questionnaire-9 scale. More than half of the participants were empty nest elders (57.4%). The overall prevalence of depressive symptom was 10.3%, while it was higher in empty nest group than in non-empty nest group (11.6% vs. 8.6%, P<0.001). A positive association was found between empty nest and depressive symptom, the OR (95%CI) was 1.223(1.045, 1.431). After stratified by gender/age/education level/employment status, this association was just prominent in participants of male, 70 years old and above, primary school education, and retirees. No matter living with spouse or living alone, empty nesters were more likely to have depressive symptoms than non-empty nesters. Cross-sectional study could not make a causation conclusion. The social supports of participants were not been investigated in detail. Empty nest elders, especially those who are male, 70 years old and above, primary school education, and retired, are more vulnerable to depressive symptom. Copyright © 2015 Elsevier B.V. All rights reserved.
Wang, Guojun; Hu, Mi; Xiao, Shui-yuan; Zhou, Liang
2017-01-01
Objective To compare loneliness, depressive symptoms and major depressive episodes between empty-nest and not-empty-nest older adults in rural areas of Liuyang city, Hunan, China. Methods A cross-sectional multi-stage random cluster survey was conducted from November 2011 to April 2012 in Liuyang, China. A total of 839 rural older residents aged 60 or above completed the survey (response rate 97.6%). In line with the definition of empty nest, 25 participants who had no children were excluded from the study, while the remaining 814 elderly adults with at least one child were included for analysis. Loneliness and depressive symptoms in rural elderly parents were assessed using the short-form UCLA Loneliness Scale (ULS-6) and the Geriatric Depression Scale (GDS). Major depressive episodes were diagnosed using the Structured Clinical Interview for DSM-IV (SCID-I). Results Significant differences were found between empty-nest and not-empty-nest older adults regarding loneliness (16.19±3.90 vs. 12.87±3.02, Cohen’s d=0.97), depressive symptoms (8.50±6.26 vs. 6.92±5.19, Cohen’s d=0.28) and the prevalence of major depressive episodes (10.1% vs. 4.6%) (all p<0.05). After controlling for demographic characteristics and physical disease, the differences in loneliness, depressive symptoms and major depressive episodes remained significant. Path analysis showed that loneliness mediated the relationship between empty-nest syndrome and depressive symptoms and major depressive episodes. Conclusion Loneliness and depression are more severe among empty-nest than not-empty-nest rural elderly adults. Loneliness was a mediating variable between empty-nest syndrome and depression. PMID:28988166
Gastric emptying of solids and liquids in obesity.
Glasbrenner, B; Pieramico, O; Brecht-Krauss, D; Baur, M; Malfertheiner, P
1993-07-01
The purpose of this study was to determine whether obese patients have different rates of solid and liquid gastric emptying compared to healthy controls. Twenty-four obese patients (7 males, 17 females) were investigated prior to dietary restriction. The patients had a weight excess above ideal weight ranging from 25% to 216% (mean weight 118.1 +/- 6.5 kg). The control group consisted of 8 healthy subjects (4 males, 4 females), within 10% of the ideal weight. The solid phase of the test meal consisted of 40 g bread, 30 g ham, 10 g margarine, and two scrambled eggs labeled with 99mTc. For the liquid phase, 200 ml orange juice was labeled with 201Tl. Three-minute counts of both tracers were taken for 106 min using a large field-of-view gamma camera. In obese patients, a significantly shortened lag phase for the emptying of solids was observed (27.0 +/- 3.3 versus 38.4 +/- 4.1 min; P < 0.05). Half-emptying time (105.9 +/- 6.7 versus 100.7 +/- 5.7 min), emptying rate (0.60 +/- 0.04 versus 0.71 +/- 0.07%/min), and total emptying of solids (49.4 +/- 3.6 versus 50.5 +/- 5.0%) were not different from controls. Obese subjects had a trend to slowed liquid emptying (half-time 82.7 +/- 4.8 versus 69.9 +/- 6.9 min; emptying rate 0.59 +/- 0.03 versus 0.65 +/- 0.03%/min; total emptying 59.8 +/- 2.9 versus 66.0 +/- 3.3%), but this was not statistically significant. There was no correlation between weight or body surface area and rate of solid or liquid gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)
Kim, Ki Han; Kim, Min Chan; Jung, Ghap Joong
2012-11-01
Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety.
Poti, Jennifer M.; Slining, Meghan M.; Popkin, Barry M.; Kenan, W.R.
2013-01-01
Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2-18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar sweetened beverages (SSBs), grain desserts, and high-fat milk from stores; high-fat milk, grain desserts, and pizza from schools; and SSBs, dairy desserts, french fries, and pizza from fast food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. In conclusion, these findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to their implementation, schools resembled fast food restaurants in their contributions to empty calorie intake. PMID:24200654
Poti, Jennifer M; Slining, Meghan M; Popkin, Barry M
2014-06-01
Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast-food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2 to 18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast-food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar-sweetened beverages, grain desserts, and high-fat milk∗ from stores; high-fat milk, grain desserts, and pizza from schools; and sugar-sweetened beverages, dairy desserts, french fries, and pizza from fast-food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. These findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast-food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to implementation of these changes, schools resembled fast-food restaurants in their contributions to empty calorie intake. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Xiang, Yu; Tao, Cheng
2018-05-01
During the operation of the personal rapid transit system(PRT), the empty vehicle resources is distributed unevenly because of different passenger demand. In order to maintain the balance between supply and demand, and to meet the passenger needs of the ride, PRT empty vehicle resource allocation model is constructed based on the future demand forecasted by historical demand in this paper. The improved genetic algorithm is implied in distribution of the empty vehicle which can reduce the customers waiting time and improve the operation efficiency of the PRT system so that all passengers can take the PRT vehicles in the shortest time. The experimental result shows that the improved genetic algorithm can allocate the empty vehicle from the system level optimally, and realize the distribution of the empty vehicle resources reasonably in the system.
Analysis of empty ATLAS pilot jobs
NASA Astrophysics Data System (ADS)
Love, P. A.; Alef, M.; Dal Pra, S.; Di Girolamo, A.; Forti, A.; Templon, J.; Vamvakopoulos, E.; ATLAS Collaboration
2017-10-01
In this analysis we quantify the wallclock time used by short empty pilot jobs on a number of WLCG compute resources. Pilot factory logs and site batch logs are used to provide independent accounts of the usage. Results show a wide variation of wallclock time used by short jobs depending on the site and queue, and changing with time. For a reference dataset of all jobs in August 2016, the fraction of wallclock time used by empty jobs per studied site ranged from 0.1% to 0.8%. Aside from the wall time used by empty pilots, we also looked at how many pilots were empty as a fraction of all pilots sent. Binning the August dataset into days, empty fractions between 2% and 90% were observed. The higher fractions correlate well with periods of few actual payloads being sent to the site.
Involvement of endogenous opiates in regulation of gastric emptying of fat test meals in mice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fioramonti, J.; Fargeas, M.J.; Bueno, L.
1988-08-01
The role of endogenous opioids and cholecystokinin (CCK) in gastric emptying was investigated in mice killed 30 min after gavage with /sup 51/Cr-radiolabeled liquid meals. The meals consisted of 0.5 ml of milk or one of five synthetic meals containing arabic gum, glucose and/or arachis oil and/or casein. Naloxone (0.1 mg/kg sc) significantly (P less than 0.01) accelerated gastric emptying of milk and meals containing fat but did not modify gastric emptying of nonfat meals. The CCK antagonist asperlicin (0.1 mg/kg ip) increased by 25% gastric emptying of milk. The gastric emptying of meals containing glucose and casein but notmore » fat was reduced after administration of the COOH-terminal octapeptide of cholecystokinin (CCK-8, 4 micrograms/kg ip). This decrease was antagonized by both asperlicin (10 mg/kg ip) and naloxone (0.1 mg/kg sc). Intracerebroventricular (icv) administration of an opiate antagonist that poorly crosses the blood-brain barrier, methyl levallorphan (10 micrograms/kg), did not modify gastric emptying of milk but accelerated it when peripherally administered (0.1 mg/kg sc). Similarly, asperlicin (icv) administered at a dose of 1 mg/kg did not affect milk emptying. These results indicate that endogenous opiates are involved at peripheral levels in the regulation of gastric emptying of fat meals only and that such regulation involves release of CCK.« less
Automatic high throughput empty ISO container verification
NASA Astrophysics Data System (ADS)
Chalmers, Alex
2007-04-01
Encouraging results are presented for the automatic analysis of radiographic images of a continuous stream of ISO containers to confirm they are truly empty. A series of image processing algorithms are described that process real-time data acquired during the actual inspection of each container and assigns each to one of the classes "empty", "not empty" or "suspect threat". This research is one step towards achieving fully automated analysis of cargo containers.
Hiyoshi, Masahide; Chijiiwa, Kazuo; Ohuchida, Jiro; Imamura, Naoya; Nagano, Motoaki
2012-06-01
Delayed gastric emptying (DGE) is a specific, worrisome complication after pancreaticoduodenectomy (PPPD), whereas subtotal stomach-preserving pancreaticoduodenectomy (SSPPD) that excises the pylorus ring seems to be effective in reducing DGE. This study compared gastric emptying and nutritional status between PPPD and SSPPD over 1 year. From June 2003 to December 2007, 41 patients (PPPD: 33, SSPPD: 8) were enrolled in this study to evaluate differences in gastric emptying and nutritional status at 1, 3, 6, 9 and 12 months after pancreaticoduodenectomy. Gastric emptying was evaluated by 13C-acetate breath test. Nutritional status (body weight, serum levels of total protein, albumin and total cholesterol) was similarly assessed. At 1 month, gastric emptying evaluated at T1/2 (half-emptying time) was significantly prolonged in the PPPD but not in the SSPPD compared to the preoperative level. Thereafter, T1/2 was decreased and showed function significantly better preserved at 3, 6 and 12 months after PPPD than after SSPPD. Body weight recovery was significantly better at 6 and 12 months after PPPD than after SSPPD. Other nutritional parameters were better preserved in the PPPD during 1-year follow-up. PPPD seems to be a more suitable surgical procedure than SSPPD in regard to gastric emptying and nutritional status.
Differential Diagnosis and Treatment of Impaired Bladder Emptying
Yoshimura, Naoki; Chancellor, Michael B
2004-01-01
Although much attention is paid to urinary incontinence, the condition of incomplete bladder emptying is becoming more common with the aging of the US population and the widespread use of anticholinergic drugs to treat overactive bladder. This disorder can often be silent until end-stage presentation of overflow incontinence. In this article, we review the pathophysiologic conditions of the bladder and urethra that can cause impaired bladder emptying and discuss how to evaluate and screen the patient with a bladder that does not empty. In addition, we provide an overview of treatment options available for impaired bladder emptying and consider the research that is under way to find the best therapies for the failing bladder. PMID:16985851
Increase of transient lower esophageal sphincter relaxation associated with cascade stomach
Kawada, Akiyo; Kusano, Motoyasu; Hosaka, Hiroko; Kuribayashi, Shiko; Shimoyama, Yasuyuki; Kawamura, Osamu; Akiyama, Junichi; Yamada, Masanobu; Akuzawa, Masako
2017-01-01
We previously reported that cascade stomach was associated with reflux symptoms and esophagitis. Delayed gastric emptying has been believed to initiate transient lower esophageal sphincter relaxation (TLESR). We hypothesized that cascade stomach may be associated with frequent TLESR with delayed gastric emptying. Eleven subjects with cascade stomach and 11 subjects without cascade stomach were enrolled. Postprandial gastroesophageal manometry and gastric emptying using a continuous 13C breath system were measured simultaneously after a liquid test meal. TLESR events were counted in early period (0–60 min), late period (60–120 min), and total monitoring period. Three parameters of gastric emptying were calculated: the half emptying time, lag time, and gastric emptying coefficient. The median frequency of TLESR events in the cascade stomach and non-cascade stomach groups was 6.0 (median), 4.6 (interquartile range) vs 5.0, 3.0 in the early period, 5.0, 3.2 vs 3.0, 1.8 in the late period, and 10.0, 6.2 vs 8.0, 5.0 in the total monitoring period. TLESR events were significantly more frequent in the cascade stomach group during the late and total monitoring periods. In contrast, gastric emptying parameters showed no significant differences between the two groups. We concluded that TLESR events were significantly more frequent in persons with cascade stomach without delayed gastric emptying. PMID:28584403
Disturbed gastric emptying in the short bowel syndrome. Evidence for a 'colonic brake'.
Nightingale, J M; Kamm, M A; van der Sijp, J R; Morris, G P; Walker, E R; Mather, S J; Britton, K E; Lennard-Jones, J E
1993-01-01
Gastric emptying of liquid (orange juice containing technetium-99m (99mTc) labelled antimony sulphide colloid) and solid (570 kcal pancake containing 0.5 mm resin microspheres labelled with Indium-111 (111-In)) was measured in seven patients with jejunum and no colon (jejunal lengths 30-160 cm), six patients with jejunum in continuity with the colon (jejunal length 25-75 cm), and in 12 normal subjects. In patients with no colon early emptying of liquid was rapid (median 25% emptying: 7 v 25 min, no colon v normal, p < 0.05); early gastric emptying of solid was rapid in two (each with less than 100 cm jejunum) and normal in the other five. Gastric emptying of liquid and solid for patients with jejunum in continuity with the colon was normal for the first three hours. There was increased liquid and solid retained in the stomach at six hours in both groups of patients (p < 0.01). Small bowel transit time was faster than in normal subjects for liquid in both groups of patients (p < 0.05) and for solid in those with no colon (p < 0.05). Rapid gastric emptying of liquid may contribute to the large stomal output in patients with a high jejunostomy. Preservation of the colon after a major small intestinal resection exerts a braking effect on the rate of early gastric emptying of liquid. PMID:8406148
Interior engineering of a viral nanoparticle and its tumor homing properties
Wen, Amy M.; Shukla, Sourabh; Saxena, Pooja; Aljabali, Alaa A.A.; Yildiz, Ibrahim; Dey, Sourav; Mealy, Joshua E.; Yang, Alice C.; Evans, David J.; Lomonossoff, George P.; Steinmetz, Nicole F.
2012-01-01
The development of multifunctional nanoparticles for medical applications is of growing technological interest. A single formulation containing imaging and/or drug moieties that is also capable of preferential uptake in specific cells would greatly enhance diagnostics and treatments. There is growing interest in plant-derived viral nanoparticles (VNPs) and establishing new platform technologies based on these nanoparticles inspired by nature. Cowpea mosaic virus (CPMV) serves as the standard model for VNPs. Although exterior surface modification is well known and has been comprehensively studied, little is known of interior modification. Additional functionality conferred by the capability for interior engineering would be of great benefit toward the ultimate goal of targeted drug delivery. Here, we examined the capacity of empty CPMV (eCPMV) particles devoid of RNA to encapsulate a wide variety of molecules. We systematically investigated the conjugation of fluorophores, biotin affinity tags, large molecular weight polymers such as polyethylene glycol (PEG), and various peptides through targeting reactive cysteines displayed selectively on the interior surface. Several methods are described that mutually confirm specific functionalization of the interior. Finally, CPMV and eCPMV were labeled with near-infrared fluorophores and studied side-by-side in vitro and in vivo. Passive tumor targeting via the enhanced permeability and retention effect and optical imaging were confirmed using a preclinical mouse model of colon cancer. The results of our studies lay the foundation for the development of the eCPMV platform in a range of biomedical applications. PMID:23121655
Schmitz, Silke; Götte, Birte; Borsch, Christian; Kunz, Clemens; Failing, Klaus; Neiger, Reto
2014-07-01
To directly compare solid-phase gastric emptying times assessed by means of a [(13)C]sodium acetate breath test ([(13)C]-SABT) and technetium Tc 99m albumin colloid radioscintigraphy ((99m)Tc-ACR) in healthy cats. 12 healthy cats. After ingestion of a test meal containing 50 mg of [(13)C]sodium acetate and 250 MBq of (99m)Tc-albumin colloid, each cat underwent simultaneous [(13)C]-SABT and (99m)Tc-ACR on 2 consecutive days. Breath samples and scintigrams were acquired at 30, 60, 90, 120, 150, 180, 210, 240, 300, 360, 480, and 600 minutes after meal ingestion. Quartiles of gastric emptying (25%, 50%, and 75%) were calculated for breath test analysis by use of the area under the curve of the (13)C:(12)C ratio. Quartiles of gastric emptying times were extrapolated from the scintigraphic findings by beans of nonlinear curve regression analysis. Mean ± SD gastric half-emptying (50%) times obtained with [(13)C]-SABT and (99m)Tc-ACR, were 239 ± 28 minutes and 276 ± 59 minutes, respectively. A 2-way repeated-measures ANOVA revealed that mean gastric emptying times determined with [(13)C]-SABT and (99m)Tc-ACR differed significantly. For the stages of gastric emptying, Pearson correlation between the 2 methods was good at 25% (r = 0.655) and weak at 50% (r = 0.588) and 75% (r = 0.566)of gastric emptying. Results indicated that the [(13)C]-SABT can be a valid alternative to (99m)Tc-ACR in healthy cats; it was easy to perform, was tolerated well by the cats, and had acceptable correlation to scintigraphic findings at gastric emptying of 25%, 50% and 75%. Studies in cats with delayed gastric emptying will be needed to verify the validity of the [(13)C]-SABT.
Kim, Ki Han; Jung, Ghap Joong
2012-01-01
Purpose Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Methods Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Results Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). Conclusion In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety. PMID:23166886
Liu, Jun-feng; Liu, Cheng-jun; Shi, Zhi-hua; Liu, Xin-bo; Jiang, Tao; Wang, Fu-shun; Cao, Fu-min; Li, Bao-qing
2013-09-01
To investigate the effect of erythromycin on electrical activity and emptying of the intrathoracic stomach after esophagectomy for esophageal cancer. Thirty patients undergoing esophagectomy for cancer and esophagogastrostomy above the aortic arch were divided into the study group (n=15) and the control group (n=15). Electrogastrography and radionuclide gastric emptying were examined for these patients before and 1, 3, 6, 12 months after surgery. Patients in the study group received erythromycin (0.25 g tid po) for 1 week before examination. The wave amplitude (Uv), dominant frequency (CPM) and percentage of normal slow wave (%) of electrogastrogram decreased after surgery and returned to normal at the first postoperative month in the study group and the 12th postoperative month in the control group (P>0.05). Gastric emptying was significantly delayed after esophagectomy, and returned to normal one year after operation in the study group (P>0.05). However, gastric emptying remained abnormal in the control group (P<0.01). Erythromycin improves electrical activity and emptying of the stomach after esophagectomy for cancer. Gastric emptying recovery later than the recovery of electrical activity, which may be related to gastric ischemia and edema.
Yu, Dan-Ting; Han, Li-Li; Zhang, Li-Mei; He, Ji-Zheng
2018-02-01
A substantial gap remains in our understanding of the abundance, diversity, and ecology of viruses in soil although some advances have been achieved in recent years. In this study, four soil samples according to the salinity gradient from shore to inland in East China have been characterized. Results showed that spherical virus particles represented the largest viral component in all of the four samples. The viromes had remarkably different taxonomic compositions, and most of the sequences were derived from single-stranded DNA viruses, especially from families Microviridae and Circoviridae. Compared with viromes from other aquatic and sediment samples, the community compositions of our four soil viromes resembled each other, meanwhile coastal sample virome closely congregated with sediment and hypersaline viromes, and high salinity paddy soil sample virome was similar with surface sediment virome. Phylogenetic analysis of functional genes showed that four viromes have high diversity of the subfamily Gokushovirinae in family Microviridae and most of Circoviridae replicase protein sequences grouped within the CRESS-DNA viruses. This work provided an initial outline of the viral communities in marine-terrestrial ecotone and will improve our understanding of the ecological functions of soil viruses.
Pandurangan, Arun Prasad; Shakeel, Shabih; Butcher, Sarah Jane; Topf, Maya
2014-01-01
Fitting of atomic components into electron cryo-microscopy (cryoEM) density maps is routinely used to understand the structure and function of macromolecular machines. Many fitting methods have been developed, but a standard protocol for successful fitting and assessment of fitted models has yet to be agreed upon among the experts in the field. Here, we created and tested a protocol that highlights important issues related to homology modelling, density map segmentation, rigid and flexible fitting, as well as the assessment of fits. As part of it, we use two different flexible fitting methods (Flex-EM and iMODfit) and demonstrate how combining the analysis of multiple fits and model assessment could result in an improved model. The protocol is applied to the case of the mature and empty capsids of Coxsackievirus A7 (CAV7) by flexibly fitting homology models into the corresponding cryoEM density maps at 8.2 and 6.1 Å resolution. As a result, and due to the improved homology models (derived from recently solved crystal structures of a close homolog – EV71 capsid – in mature and empty forms), the final models present an improvement over previously published models. In close agreement with the capsid expansion observed in the EV71 structures, the new CAV7 models reveal that the expansion is accompanied by ∼5° counterclockwise rotation of the asymmetric unit, predominantly contributed by the capsid protein VP1. The protocol could be applied not only to viral capsids but also to many other complexes characterised by a combination of atomic structure modelling and cryoEM density fitting. PMID:24333899
Expression of the highly conserved vaccinia virus E6 protein is required for virion morphogenesis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Resch, Wolfgang; Weisberg, Andrea S.; Moss, Bernard, E-mail: bmoss@nih.go
2009-04-10
The vaccinia virus E6R gene (VACVWR062) is conserved in all members of the poxvirus family and encodes a protein associated with the mature virion. We confirmed this association and provided evidence for an internal location. An inducible mutant that conditionally expresses E6 was constructed. In the absence of inducer, plaque formation and virus production were severely inhibited in several cell lines, whereas some replication occurred in others. This difference could be due to variation in the stringency of repression, since we could not isolate a stable deletion mutant even in the more 'permissive' cells. Under non-permissive conditions, viral late proteinsmore » were synthesized but processing of core proteins was inefficient, indicative of an assembly block. Transmission electron microscopy of sections of cells infected with the mutant in the absence of inducer revealed morphogenetic defects with crescents and empty immature virions adjacent to dense inclusions of viroplasm. Mature virions were infrequent and cores appeared to have lucent centers.« less
Tsoukali, E; Gouvas, N; Tsiaoussis, J; Pechlivanides, G; Zervakis, N; Mantides, A; Xynos, E
2011-09-01
Esophageal emptying assessed at the 'timed barium' esophagogram correlates well with symptomatic outcomes after pneumatic dilation for esophageal achalasia, although 30% of patients with satisfactory outcome exhibit partial improvement in emptying. The aim of the study was to investigate any correlation of esophageal emptying to symptomatic response after laparoscopic Heller's myotomy and Dor's fundoplication. 'Bread and barium' (transit time of a barium opaque bread bolus) and 'timed barium' (height of esophageal barium column 5 minutes after ingestion of 200-250 mL of barium suspension) esophagogram was used to assess esophageal emptying in 73 patients with esophageal achalasia before 1 and 5 years (31 cases) after laparoscopic myotomy and anterior fundoplication. Symptoms assessment was based to a specific score. At 1-year follow-up, excellent and good symptomatic results were obtained in 95% of the cases. Esophageal maximum diameter, esophageal transit time, and esophageal barium column were significantly correlated to each other and to symptom score postoperatively (P < 0.001). Complete and partial (<90% and 50-90% postoperative reduction in barium column, respectively) emptying was seen in 55% and 31% of patients with excellent result. Patients with a pseudodiverticulum postoperatively had a more delayed esophageal emptying than those without. Symptomatic outcome and esophageal emptying did not deteriorate at 5-year follow-up. Esophageal emptying assessed by 'barium and bread' and 'timed barium' esophagogram correlated well with symptomatic outcome after laparoscopic myotomy for esophageal achalasia. Complete symptomatic relief does not necessarily reflect complete esophageal emptying. Outcomes do not deteriorate by time. Because of wide availability, esophagogram can be applied in follow-up of postmyotomy patients in conjunction with symptomatic evaluation. © 2011 Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.
Effects of rehabilitation management on gastric emptying function in older adults with diabetes.
Shao, Z M; Yao, J F; Chen, J; Yu, Z W; Yu, X F; Zheng, J J; Tang, X
2014-01-24
The relationship between gastric emptying dysfunction and blood glucose concentration in elderly with type 2 diabetes mellitus was investigated, and the effect of rehabilitation exercise prescription training on gastric emptying in the geriatric diabetic patients was evaluated. A total of 160 older type 2 diabetic adults and 30 cases of non-diabetic patients were studied with regard to the gastric half emptying time (GET1/2) of solid meals radiolabelled with 99mTc. Eighty delayed gastric emptying diabetic patients were randomly divided into 4 four groups: rehabilitation exercise + mosapride group (N = 20), rehabilitation exercise group (N = 20), mosapride group (N = 20), and control group (N = 20). The level of blood glucose was measured every six months in a two-year follow-up. The solid GET1/2 of regulated blood glycemic control patients showed no statistically significant differences from non-diabetic patients (P > 0.05). However, the value for poor blood glycemic control patients exhibited significant statistical differences compared with both non-diabetic (P < 0.01) and regulated blood glycemic control group patients (P < 0.01). It showed that the gastric emptying time improved in the rehabilitation exercise group, mosapride group and rehabilitation exercise group + mosapride group after two years of treatment (P < 0.05). Fasting blood glucose in both rehabilitation exercise group and rehabilitation exercise + mosapride group was significantly decreased. Postprandial blood glucose in the rehabilitation exercise group, mosapride group, rehabilitation exercise group + mosapride group was significantly decreased. High blood glucose level can delay gastric emptying in older type 2 diabetic patients. Gastric emptying and blood glucose control affect each other. It was shown that appropriate rehabilitation exercise combined with prokinetic agent may improve gastric emptying in some geriatric type 2 diabetic patients and help control their blood glucose.
Gastric emptying, postprandial blood pressure, glycaemia and splanchnic flow in Parkinson's disease.
Trahair, Laurence G; Kimber, Thomas E; Flabouris, Katerina; Horowitz, Michael; Jones, Karen L
2016-05-28
To determine gastric emptying, blood pressure, mesenteric artery blood flow, and blood glucose responses to oral glucose in Parkinson's disease. Twenty-one subjects (13 M, 8 F; age 64.2 ± 1.6 years) with mild to moderate Parkinson's disease (Hoehn and Yahr score 1.4 ± 0.1, duration of known disease 6.3 ± 0.9 years) consumed a 75 g glucose drink, labelled with 20 MBq (99m)Tc-calcium phytate. Gastric emptying was quantified with scintigraphy, blood pressure and heart rate with an automated device, superior mesenteric artery blood flow by Doppler ultrasonography and blood glucose by glucometer for 180 min. Autonomic nerve function was evaluated with cardiovascular reflex tests and upper gastrointestinal symptoms by questionnaire. The mean gastric half-emptying time was 106 ± 9.1 min, gastric emptying was abnormally delayed in 3 subjects (14%). Systolic and diastolic blood pressure fell (P < 0.001) and mesenteric blood flow and blood glucose (P < 0.001 for both) increased, following the drink. Three subjects (14%) had definite autonomic neuropathy and 8 (38%) had postprandial hypotension. There were no significant relationships between changes in blood pressure, heart rate or mesenteric artery blood flow with gastric emptying. Gastric emptying was related to the score for autonomic nerve function (R = 0.55, P < 0.01). There was an inverse relationship between the blood glucose at t = 30 min (R = -0.52, P < 0.05), while the blood glucose at t = 180 min was related directly (R = 0.49, P < 0.05), with gastric emptying. In mild to moderate Parkinson's disease, gastric emptying is related to autonomic dysfunction and a determinant of the glycaemic response to oral glucose.
Sakamoto, Yasunari; Sekino, Yusuke; Yamada, Eiji; Ohkubo, Hidenori; Higurashi, Takuma; Sakai, Eiji; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Nonaka, Takashi; Ikeda, Tamon; Fujita, Koji; Yoneda, Masato; Koide, Tomoko; Takahashi, Hirokazu; Goto, Ayumu; Abe, Yasunobu; Gotoh, Eiji; Maeda, Shin; Nakajima, Atsushi
2011-01-01
Background/Aims The administration of liquid nutrients to patients is often accompanied by complications such as gastroesophageal reflux. To prevent gastroesophageal reflux, high-viscosity liquid meals are used widely, however, it still remains controversial whether high-viscosity liquid meals have any effect on the rate of gastric emptying. The present study was conducted with the aim of determining whether high-viscosity liquid meals had any effect on the rate of gastric emptying and mosapride might accelerate the rate of gastric emptying of high-viscosity liquid meals. Methods Six healthy male volunteers underwent 3 tests at intervals of > 1 week. After fasting for > 8 hours, each subject received one of three test meals (liquid meal only, high-viscosity liquid meal [liquid meal plus pectin] only, or high-viscosity liquid meal 30 minutes after intake of mosapride). A 13C-acetic acid breath test was performed, which monitored the rate of gastric emptying for 4 hours. Using the Oridion Research Software (β version), breath test parameters were calculated. The study parameters were examined for all the 3 test conditions and compared using the Freidman test. Results Gastric emptying was significantly delayed following intake of a high-viscosity liquid meal alone as compared with a liquid meal alone; however, intake of mosapride prior to a high-viscosity liquid meal was associated with a significantly accelerated rate of gastric emptying as compared with a high-viscosity liquid meal alone. Conclusions This study showed that high-viscosity liquid meals delayed gastric emptying: however, mosapride recovered the delayed rate of gastric emptying by high-viscosity liquid meals. PMID:22148109
[*C]octanoic acid breath test to measure gastric emptying rate of solids.
Maes, B D; Ghoos, Y F; Rutgeerts, P J; Hiele, M I; Geypens, B; Vantrappen, G
1994-12-01
We have developed a breath test to measure solid gastric emptying using a standardized scrambled egg test meal (250 kcal) labeled with [14C]octanoic acid or [13C]octanoic acid. In vitro incubation studies showed that octanoic acid is a reliable marker of the solid phase. The breath test was validated in 36 subjects by simultaneous radioscintigraphic and breath test measurements. Nine healthy volunteers were studied after intravenous administration of 200 mg erythromycin and peroral administration of 30 mg propantheline, respectively. Erythromycin significantly enhanced gastric emptying, while propantheline significantly reduced gastric emptying rates. We conclude that the [*C]octanoic breath test is a promising and reliable test for measuring the gastric emptying rate of solids.
Delayed Gastric Emptying after Living Donor Hepatectomy for Liver Transplantation
Griesemer, Adam D.; Parsons, Ronald F.; Graham, Jay A.; Emond, Jean C.; Samstein, Benjamin
2014-01-01
Delayed gastric emptying is a significant postoperative complication of living donor hepatectomy for liver transplantation and may require endoscopic or surgical intervention in severe cases. Although the mechanism of posthepatectomy delayed gastric emptying remains unknown, vagal nerve injury during intraoperative dissection and adhesion formation postoperatively between the stomach and cut liver surface are possible explanations. Here, we present the first reported case of delayed gastric emptying following fully laparoscopic hepatectomy for living donor liver transplantation. Additionally, we also present a case in which symptoms developed after open right hepatectomy, but for which dissection for left hepatectomy was first performed. Through our experience and these two specific cases, we favor a neurovascular etiology for delayed gastric emptying after hepatectomy. PMID:25610698
Simulation of empty container logistic management at depot
NASA Astrophysics Data System (ADS)
Sze, San-Nah; Sek, Siaw-Ying Doreen; Chiew, Kang-Leng; Tiong, Wei-King
2017-07-01
This study focuses on the empty container management problem in a deficit regional area. Deficit area is the area having more export activities than the import activities, which always have a shortage of empty container. This environment has challenged the trading companies in the decision making in distributing the empty containers. A simulation model that fit to the environment is developed. Besides, a simple heuristic algorithm with some hard and soft constraints consideration are proposed to plan the logistic of empty container supply. Then, the feasible route with the minimum cost will be determined by applying the proposed heuristic algorithm. The heuristic algorithm can be divided into three main phases which are data sorting, data assigning and time window updating.
Kimura, Yoshiyuki; Sumiyoshi, Maho
2011-09-01
The Swertia japonica is used clinically as a remedy for gastrointestinal symptoms in Japan. We examined the effects of a S. japonica and swertiamarin on gastric emptying and gastrointestinal motility in atropine-, dopamine-, and 5-hydroxytryptamine (5-HT)-treated mice. All three preparations inhibited reductions in gastric emptying and gastrointestinal motility induced by dopamine (1mg/kg, intraperitoneal injection, ip). Neither the powder, swertiamarin, nor itopride had any effect on the reductions in gastric emptying and gastrointestinal motility caused by 5-HT (4 mg/kg, ip). These findings suggest that the powder and swertiamarin stimulate gastric emptying and gastrointestinal motility by inhibiting the dopamine D(2) receptor. Copyright © 2011 Elsevier B.V. All rights reserved.
Pereiro, Patricia; Dios, Sonia; Boltaña, Sebastián; Coll, Julio; Estepa, Amparo; Mackenzie, Simon; Novoa, Beatriz; Figueras, Antonio
2014-01-01
DNA vaccines encoding the viral G glycoprotein show the most successful protection capability against fish rhabdoviruses. Nowadays, the molecular mechanisms underlying the protective response remain still poorly understood. With the aim of shedding light on the protection conferred by the DNA vaccines based in the G glycoprotein of viral haemorrhagic septicaemia virus (VHSV) in turbot (Scophthalmus maximus) we have used a specific microarray highly enriched in antiviral sequences to carry out the transcriptomic study associated to VHSV DNA vaccination/infection. The differential gene expression pattern in response to empty plasmid (pMCV1.4) and DNA vaccine (pMCV1.4-G860) intramuscular administration with regard to non-stimulated turbot was analyzed in head kidney at 8, 24 and 72 hours post-vaccination. Moreover, the effect of VHSV infection one month after immunization was also analyzed in vaccinated and non-vaccinated fish at the same time points. Genes implicated in the Toll-like receptor signalling pathway, IFN inducible/regulatory proteins, numerous sequences implicated in apoptosis and cytotoxic pathways, MHC class I antigens, as well as complement and coagulation cascades among others were analyzed in the different experimental groups. Fish receiving the pMCV1.4-G860 vaccine showed transcriptomic patterns very different to the ones observed in pMCV1.4-injected turbot after 72 h. On the other hand, VHSV challenge in vaccinated and non-vaccinated turbot induced a highly different response at the transcriptome level, indicating a very relevant role of the acquired immunity in vaccinated fish able to alter the typical innate immune response profile observed in non-vaccinated individuals. This exhaustive transcriptome study will serve as a complete overview for a better understanding of the crosstalk between the innate and adaptive immune response in fish after viral infection/vaccination. Moreover, it provides interesting clues about molecules with a potential use as vaccine adjuvants, antiviral treatments or markers for vaccine efficiency monitoring. PMID:25098168
A DISTANT ECHO OF MILKY WAY CENTRAL ACTIVITY CLOSES THE GALAXY’s BARYON CENSUS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nicastro, F.; Senatore, F.; Krongold, Y.
2016-09-01
We report on the presence of large amounts of million-degree gas in the Milky Way’s interstellar and circum-galactic medium. This gas (1) permeates both the Galactic plane and the halo, (2) extends to distances larger than 60–200 kpc from the center, and (3) its mass is sufficient to close the Galaxy’s baryon census. Moreover, we show that a vast, ∼6 kpc radius, spherically symmetric central region of the Milky Way above and below the 0.16 kpc thick plane has either been emptied of hot gas or the density of this gas within the cavity has a peculiar profile, increasing frommore » the center up to a radius of ∼6 kpc, and then decreasing with a typical halo density profile. This, and several other converging pieces of evidence, suggest that the current surface of the cavity, at 6 kpc from the Galaxy’s center, traces the distant echo of a period of strong nuclear activity of our supermassive black hole, occurring about 6 Myr ago.« less
Reach Out and Eat: Food and Beverages Depicted in Books for Preschoolers.
England, Jessica L; Linchey, Jennifer; Madsen, Kristine A; Patel, Anisha I
2015-11-01
To examine food and beverage depictions in books for preschoolers. Books for preschoolers from Reach Out and Read (ROR; n = 42), public library (n = 27), and Publisher's Weekly booklists (n = 31) were examined for nutritive and empty-calorie food and beverage depictions. It was found that 66% of books depicted at least 1 food or beverage. More books depicted nutritive items than empty-calorie items (87.5% vs 54.7%, P < .001). There was a trend toward fewer empty-calorie depictions in ROR books than in other booklists. Yet nearly half of ROR books depicted at least 1 empty-calorie item. ROR books also accounted for 5 of 10 books with the most empty-calorie item depictions and 3 of 4 books with branding. With regard to messaging, approximately a third of books with the most empty-calorie depictions promoted unhealthy foods. When selecting books for ROR, it may be important to consider food and beverage depictions and messages. © The Author(s) 2015.
Reach Out and Eat: Food and Beverages Depicted in Books for Preschoolers
England, Jessica L.; Linchey, Jennifer; Madsen, Kristine A.; Patel, Anisha I.
2015-01-01
Objective To examine food and beverage depictions in books for preschoolers. Methods Books for preschoolers from Reach Out and Read (ROR; n = 42), public library (n = 27), and Publisher's Weekly booklists (n = 31) were examined for nutritive and empty-calorie food and beverage depictions. Results It was found that 66% of books depicted at least I food or beverage. More books depicted nutritive items than empty-calorie items (87.5% vs 54.7%, P < .001). There was a trend toward fewer empty-calorie depictions in ROR books than in other booklists. Yet nearly half of ROR books depicted at least I empty-calorie item. ROR books also accounted for 5 of 10 books with the most empty-calorie item depictions and 3 of 4 books with branding. With regard to messaging, approximately a third of books with the most empty-calorie depictions promoted unhealthy foods. Conclusions When selecting books for ROR, it may be important to consider food and beverage depictions and messages. PMID:25715825
Postpyloric regulation of gastric emptying in rhesus monkeys.
McHugh, P R; Moran, T H; Wirth, J B
1982-09-01
Saline (0.9% NaCl) empties rapidly and exponentially from the stomach of the rhesus monkey, but glucose solutions empty at a calorie-constant rate of 0.4 kcal/min. By means of indwelling intragastric and intraduodenal cannulae we can demonstrate an inhibition on the delivery of saline from the stomach provoked by glucose placed beyond the pylorus. The inhibition varies directly with the glucose calories in the intestine and averages 2.5 min/kcal. That these two results (0.4 kcal/min and 2.5 min/kcal) are reciprocals suggests a feedback inhibition on the gastric emptying of nutrients arising from beyond the pylorus and adequate to explain the rate of glucose delivery to the intestine. A control theory description of gastric emptying that includes such feedback regulation can be derived from these data to explain the different gastric emptying patterns of nutrients and nonnutrient solutions. These patterns give this visceral system a precision in its management of nutrients that can provide information crucial to preabsorptive satiety.
Assessment of gastric emptying in non-obese diabetic mice using a [13C]-octanoic acid breath test.
Creedon, Christopher T; Verhulst, Pieter-Jan; Choi, Kyoung M; Mason, Jessica E; Linden, David R; Szurszewski, Joseph H; Gibbons, Simon J; Farrugia, Gianrico
2013-03-23
Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used techniques require killing of the animals and postmortem recovery of the meal(1,2). This approach prevents longitudinal studies to determine changes in gastric emptying with age and progression of disease. The commonly used [(13)C]-octanoic acid breath test for humans(3) has been modified for use in mice(4-6) and rats(7) and we previously showed that this test is reliable and responsive to changes in gastric emptying in response to drugs and during diabetic disease progression(8). In this video presentation the principle and practical implementation of this modified test is explained. As in the previous study, NOD LtJ mice are used, a model of type 1 diabetes(9). A proportion of these mice develop the symptoms of gastroparesis, a complication of diabetes characterized by delayed gastric emptying without mechanical obstruction of the stomach(10). This paper demonstrates how to train the mice for testing, how to prepare the test meal and obtain 4 hr gastric emptying data and how to analyze the obtained data. The carbon isotope analyzer used in the present study is suitable for the automatic sampling of the air samples from up to 12 mice at the same time. This technique allows the longitudinal follow-up of gastric emptying from larger groups of mice with diabetes or other long-standing diseases.
Chirwa, Charles F. C.; Hall, Ralph P.; Krometis, Leigh-Anne H.; Vance, Eric A.; Edwards, Adam; Guan, Ting; Holm, Rochelle H.
2017-01-01
Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology. PMID:28165378
Delayed gastric emptying does not normalize after gluten withdrawal in adult celiac disease.
Usai-Satta, Paolo; Oppia, Francesco; Scarpa, Mariella; Giannetti, Cristiana; Cabras, Francesco
2016-08-01
Objective Delayed gastric emptying has been frequently detected in patients with untreated celiac disease. According to several studies, gluten withdrawal showed to be effective in normalizing the gastric emptying rate. The aim of this study was to evaluate the gastric emptying rate of solids in patients with celiac disease before and after a gluten-free diet. Methods Twelve adult patients with celiac disease (age range 20-57 years) and 30 healthy controls (age range 30-54 years) underwent a (13)C-octanoic acid breath test to measure gastric emptying. Half emptying time (t1/2) and lag phase (tlag) were calculated. After at least 12 months of a gluten-free diet, celiac patients underwent a new (13)C-octanoic acid breath test. A symptom score was utilized to detect dyspeptic and malabsorption symptoms in all the patients. Results The gastric motility parameters, t1/2 and tlag, were significantly longer in patients than in controls. On a gluten-free diet, surprisingly, the gastric emptying did not normalize despite an improvement of symptom score. No significant correlation between abnormal gastric emptying and specific symptom patterns, anthropometric parameters or severity of histological damage was found. Conclusions This finding supports the hypothesis that gluten-driven mucosal inflammation might determine motor abnormalities by affecting smooth muscle contractility or impairing gut hormone function. The persistence of these abnormalities on a gluten free diet suggests the presence of a persistent low-grade mucosal inflammation with a permanent perturbation of the neuro-immunomodulatory regulation.
Matsumoto, Kenjiro; Kimura, Hiroshi; Tashima, Kimihito; Uchida, Masayuki; Horie, Syunji
2008-10-01
Several methods are used to evaluate gastric motility in rodents, but they all have technical limitations. Recent technical developments enable a convenient method to evaluate gastric motility. The (13)C-acetic acid breath test in rodents is a non-invasive and repeatable method that can be used without physical restraints. The present study aimed to validate the (13)C-acetic acid breath test by measuring the effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice. Loperamide (1-10 mg/kg) and morphine (1.25-10 mg/kg) slowed gastric emptying and decreased the maximum concentration (C(max)) and area under the curve (AUC(90 min)) value in a dose-dependent manner. Mosapride (0.2-5 mg/kg) accelerated gastric emptying and increased C(max) value. Mosapride (20 mg/kg) did not accelerate gastric emptying on the (13)C-breath test. Itopride (30 mg/kg, per os) significantly accelerated gastric emptying compared with the vehicle group. In a comparison with the conventional phenol red test, there was a correlation between the C(max) value of breath test and gastric emptying (%) of phenol red tests in treatment with loperamide or mosapride. These results indicate that the (13)C-acetic acid breath test is an accurate, noninvasive, and simple method for monitoring gastric emptying in mice. This method is useful to assess the effect of drugs and gut function pharmacologically.
Sanaka, Masaki; Yamamoto, Takatsugu; Ishii, Tarou; Kuyama, Yasushi
2004-01-01
In pharmacokinetics, the Wagner-Nelson (W-N) method can accurately estimate the rate of drug absorption from its urinary elimination rate. A stable isotope (13C) breath test attempts to estimate the rate of absorption of 13C, as an index of gastric emptying rate, from the rate of pulmonary elimination of 13CO2. The time-gastric emptying curve determined by the breath test is quite different from that determined by scintigraphy or ultrasonography. In this report, we have shown that the W-N method can adjust the difference. The W-N equation to estimate gastric emptying from breath data is as follows: the fractional cumulative amount of gastric contents emptied by time t = Abreath (t)/Abreath (infinity) + (1/0.65).d[Abreath (t)/Abreath (infinity) ]/dt, where Abreath (t) = the cumulative recovery of 13CO2 in breath by time t and Abreath ( infinity ) = the ultimate cumulative 13CO2 recovery. The emptying flow curve generated by ultrasonography was compared with that generated by the W-N method-adjusted breath test in 6 volunteers. The emptying curves by the W-N method were almost identical to those by ultrasound. The W-N method can generate an accurate emptying flow curve from 13CO2 data, and it can adjust the difference between ultrasonography and the breath test. Copyright 2004 S. Karger AG, Basel
49 CFR 173.428 - Empty Class 7 (radioactive) materials packaging.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Empty Class 7 (radioactive) materials packaging... SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.428 Empty Class 7 (radioactive) materials packaging. A packaging which previously contained Class 7 (radioactive...
Directional budding of human immunodeficiency virus from monocytes.
Perotti, M E; Tan, X; Phillips, D M
1996-01-01
Time-lapse cinematography revealed that activated human immunodeficiency virus (HIV)-infected monocytes crawl along surfaces, putting forward a leading pseudopod. Scanning electron micrographs showed monocyte pseudopods associated with spherical structures the size of HIV virions, and transmission electron micrographs revealed HIV virions budding from pseudopods. Filamentous actin (F-actin) was localized by electron microscopy in the pseudopod by heavy meromyosin decoration. Colocalization of F-actin and p24 viral antigen by light microscopy immunofluorescence indicated that F-actin and virus were present on the same pseudopod. These observations indicate that monocytes produce virus from a leading pseudopod. We suggest that HIV secretion at the leading edges of donor monocytes/macrophages may be an efficient way for HIV to infect target cells. PMID:8709212
A spectroscopic and photometric study of the planetary nebulae Kn 61 and Pa 5
DOE Office of Scientific and Technical Information (OSTI.GOV)
García-Díaz, Ma. T.; González-Buitrago, D.; López, J. A.
2014-09-01
We present the first morpho-kinematical analysis of the planetary nebulae Kn 61 and Pa 5 and explore the nature of their central stars. Our analysis is based on high-resolution and medium-resolution spectroscopic observations, deep narrow-band imaging, and integral photometry. This material allows us to identify the morphological components and study their kinematics. The direct images and spectra indicate an absence of the characteristic [N II] and [S II] emission lines in both nebulae. The nebular spectrum of Kn 61 suggests a hydrogen deficient planetary nebula and the stellar spectrum of the central star reveals a hydrogen-deficient PG 1159-type star. Themore » [O III] position velocity diagram reveals that Kn 61 is a closed, empty, spherical shell with a thin border and a filamentary surface expanding at 67.6 km s{sup –1} and the shell is currently not expanding isotropically. We derived a kinematic age of ∼1.6 × 10{sup 4} yr for an assumed distance of 4 kpc. A photometric period of ∼5.7(±0.4) days has been detected for Kn 61, indicating the presence of a possible binary system at its core. A possible link between filamentary spherical shells and PG 1159-type stars is noted. The morphology of Pa 5 is dominated by an equatorial toroid and faint polar extensions. The equatorial region of this planetary nebula is expanding at 45.2 km s{sup –1}. The stellar spectrum corresponds to a very hot star and is dominated by a steep blue rising continuum and He II, Balmer, and Ca II photospheric lines.« less
27 CFR 25.36 - Empty container storage.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Construction and Equipment Equipment § 25.36 Empty container storage...
27 CFR 25.36 - Empty container storage.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...
27 CFR 25.36 - Empty container storage.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...
27 CFR 25.36 - Empty container storage.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...
14 CFR 29.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...
14 CFR 27.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 27.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 23.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2013 CFR
2013-01-01
... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...
14 CFR 27.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 25.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 25.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 29.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...
14 CFR 23.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2010 CFR
2010-01-01
... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...
14 CFR 29.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...
14 CFR 25.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 27.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 29.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...
14 CFR 27.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 29.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...
14 CFR 25.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 23.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2011 CFR
2011-01-01
... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...
14 CFR 23.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2014 CFR
2014-01-01
... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...
14 CFR 25.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...
14 CFR 23.29 - Empty weight and corresponding center of gravity.
Code of Federal Regulations, 2012 CFR
2012-01-01
... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...
Effect of Jiangzhi tablet on gastrointestinal propulsive function in mice
NASA Astrophysics Data System (ADS)
Wang, Xiangrong; Geng, Xiuli; Zhao, Jingsheng; Fan, Lili; Zhang, Zhengchen
2018-04-01
This paper aims to study the effect of lipid-lowering tablets on gastric emptying and small intestinal propulsion in mice. Mice were randomly divided into control group, Digestant Pill group, Jiangzhi tablet group, middle dose and small dose, the mice gastric emptying phenolsulfonphthalein, gastric residual rate of phenol red indicator to evaluate the gastric emptying rate, residual rate of detection in mouse stomach; small intestine propulsion and selection of carbon ink as the experimental index. Effects were observed to promote the function of normal mice gastric emptying and intestine. The gastric emptying and small intestinal motor function of normal mice were all promoted by each administration group, and the effect was most obvious in small dose group. The effect of reducing blood lipid on gastrointestinal motility of mice ware obviously enhanced.
Effects of empty bins on image upscaling in capsule endoscopy
NASA Astrophysics Data System (ADS)
Rukundo, Olivier
2017-07-01
This paper presents a preliminary study of the effect of empty bins on image upscaling in capsule endoscopy. The presented study was conducted based on results of existing contrast enhancement and interpolation methods. A low contrast enhancement method based on pixels consecutiveness and modified bilinear weighting scheme has been developed to distinguish between necessary empty bins and unnecessary empty bins in the effort to minimize the number of empty bins in the input image, before further processing. Linear interpolation methods have been used for upscaling input images with stretched histograms. Upscaling error differences and similarity indices between pairs of interpolation methods have been quantified using the mean squared error and feature similarity index techniques. Simulation results demonstrated more promising effects using the developed method than other contrast enhancement methods mentioned.
Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar Es Salaam, Tanzania
Jenkins, Marion W.; Cumming, Oliver; Cairncross, Sandy
2015-01-01
Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed. PMID:25734790
Bajzer, Željko; Gibbons, Simon J.; Coleman, Heidi D.; Linden, David R.
2015-01-01
Noninvasive breath tests for gastric emptying are important techniques for understanding the changes in gastric motility that occur in disease or in response to drugs. Mice are often used as an animal model; however, the gamma variate model currently used for data analysis does not always fit the data appropriately. The aim of this study was to determine appropriate mathematical models to better fit mouse gastric emptying data including when two peaks are present in the gastric emptying curve. We fitted 175 gastric emptying data sets with two standard models (gamma variate and power exponential), with a gamma variate model that includes stretched exponential and with a proposed two-component model. The appropriateness of the fit was assessed by the Akaike Information Criterion. We found that extension of the gamma variate model to include a stretched exponential improves the fit, which allows for a better estimation of T1/2 and Tlag. When two distinct peaks in gastric emptying are present, a two-component model is required for the most appropriate fit. We conclude that use of a stretched exponential gamma variate model and when appropriate a two-component model will result in a better estimate of physiologically relevant parameters when analyzing mouse gastric emptying data. PMID:26045615
Exploring gastric emptying rate in minipigs: Effect of food type and pre-dosing of metoclopramide.
Henze, Laura J; Griffin, Brendan T; Christiansen, Martin; Bundgaard, Christoffer; Langguth, Peter; Holm, René
2018-06-15
The present study investigated the gastric emptying rate in Göttingen minipigs pre- and post-prandial and evaluated the effect of metoclopramide on the same parameter, using paracetamol as an absorption marker. The pharmacokinetic evaluation of the obtained plasma concentration data for paracetamol demonstrated that the fastest gastric emptying rate was observed in the animals that were allowed access to normal pig food. There was no significant difference in the stomach emptying rate observed between fasted and fed minipigs, when fed either with a FDA standard breakfast or a nutritional energy drink. Pre-dosing minipigs with metoclopramide (0.2 or 0.4 mg/kg) did not demonstrate any effect on gastric emptying in either the fasted or fed state. The data in the present study demonstrated a relatively prolonged gastric emptying rate in mini-pigs both in the fasted and fed state, hence when conducting pharmacokinetic studies using minipigs, this should be taken into account when planning the plasma sampling time points. Further, as no difference could be observed in gastric emptying rate as a function of food, the data also suggest that the Göttingen mini-pigs seems less suited to predict for food effect studies than other species. Copyright © 2018 Elsevier B.V. All rights reserved.
Murray, R
1987-01-01
A variety of beverages formulated to provide fluid, carbohydrates, and electrolytes during and following exercise are commercially available. Such 'sport drinks' commonly contain 4 to 8% carbohydrate (as glucose, fructose, sucrose or maltodextrins) and small amounts of electrolytes (most often sodium, potassium, and chloride). The efficacy of consuming such beverages has been questioned primarily because of concern that beverage carbohydrate content may inhibit gastric emptying rate and fluid absorption during exercise, thereby jeopardizing physiological homeostasis and impairing exercise performance. Gastric motor activity, and consequently gastric emptying rate, is governed by neural and humoral feedback provided by receptors found in the gastric musculature and proximal small intestine. Gastric emptying rate may be influenced by a variety of factors including, but not limited to, the caloric content, volume, osmolality, temperature, and pH of the ingested fluid, diurnal and interindividual variation, metabolic state (rest/exercise), and the ambient temperature. The caloric content of the ingested fluid appears to be the most important variable governing gastric emptying rate, providing a mean caloric efflux from the stomach of 2.0 to 2.5 kcal/min for ingested fluid volumes less than 400 ml. At rest, gastric emptying is inhibited by solutions containing calories in a manner independent of the nutrient source (i.e. carbohydrate, fat or protein). Consequently, plain water is known to empty from the stomachs of resting subjects at rates faster than solutions containing calories. Gastric emptying is increasingly inhibited as the caloric content of the ingested fluid increases. During moderate exercise (less than 75% VO2max), gastric emptying occurs at a rate similar to that during rest; more intense exercise appears to inhibit gastric emptying. When fluids are consumed at regular intervals throughout prolonged exercise (greater than 2 hours), postexercise aspiration of stomach contents reveals that solutions containing up to 10% carbohydrate empty at rates similar to plain water. There is ample physiological justification for the addition of glucose, fructose, sodium, potassium and chloride to fluid replacement beverages. Fluid absorption in the small intestine is stimulated by glucose and sodium (and to a lesser extent by fructose and other electrolytes). Glucose and sodium are absorbed via a common membrane carrier in the mucosal epithelium of the proximal small intestine. The potentiation of sodium uptake by glucose establishes an osmotic gradient for fluid absorption.(ABSTRACT TRUNCATED AT 400 WORDS)
Contrast-Enhanced Magnetic Resonance Imaging of Gastric Emptying and Motility in Rats.
Lu, Kun-Han; Cao, Jiayue; Oleson, Steven Thomas; Powley, Terry L; Liu, Zhongming
2017-11-01
The assessment of gastric emptying and motility in humans and animals typically requires radioactive imaging or invasive measurements. Here, we developed a robust strategy to image and characterize gastric emptying and motility in rats based on contrast-enhanced magnetic resonance imaging (MRI) and computer-assisted image processing. The animals were trained to naturally consume a gadolinium-labeled dietgel while bypassing any need for oral gavage. Following this test meal, the animals were scanned under low-dose anesthesia for high-resolution T1-weighted MRI in 7 Tesla, visualizing the time-varying distribution of the meal with greatly enhanced contrast against non-gastrointestinal (GI) tissues. Such contrast-enhanced images not only depicted the gastric anatomy, but also captured and quantified stomach emptying, intestinal filling, antral contraction, and intestinal absorption with fully automated image processing. Over four postingestion hours, the stomach emptied by 27%, largely attributed to the emptying of the forestomach rather than the corpus and the antrum, and most notable during the first 30 min. Stomach emptying was accompanied by intestinal filling for the first 2 h, whereas afterward intestinal absorption was observable as cumulative contrast enhancement in the renal medulla. The antral contraction was captured as a peristaltic wave propagating from the proximal to distal antrum. The frequency, velocity, and amplitude of the antral contraction were on average 6.34 ± 0.07 contractions per minute, 0.67 ± 0.01 mm/s, and 30.58 ± 1.03%, respectively. These results demonstrate an optimized MRI-based strategy to assess gastric emptying and motility in healthy rats, paving the way for using this technique to understand GI diseases, or test new therapeutics in rat models.The assessment of gastric emptying and motility in humans and animals typically requires radioactive imaging or invasive measurements. Here, we developed a robust strategy to image and characterize gastric emptying and motility in rats based on contrast-enhanced magnetic resonance imaging (MRI) and computer-assisted image processing. The animals were trained to naturally consume a gadolinium-labeled dietgel while bypassing any need for oral gavage. Following this test meal, the animals were scanned under low-dose anesthesia for high-resolution T1-weighted MRI in 7 Tesla, visualizing the time-varying distribution of the meal with greatly enhanced contrast against non-gastrointestinal (GI) tissues. Such contrast-enhanced images not only depicted the gastric anatomy, but also captured and quantified stomach emptying, intestinal filling, antral contraction, and intestinal absorption with fully automated image processing. Over four postingestion hours, the stomach emptied by 27%, largely attributed to the emptying of the forestomach rather than the corpus and the antrum, and most notable during the first 30 min. Stomach emptying was accompanied by intestinal filling for the first 2 h, whereas afterward intestinal absorption was observable as cumulative contrast enhancement in the renal medulla. The antral contraction was captured as a peristaltic wave propagating from the proximal to distal antrum. The frequency, velocity, and amplitude of the antral contraction were on average 6.34 ± 0.07 contractions per minute, 0.67 ± 0.01 mm/s, and 30.58 ± 1.03%, respectively. These results demonstrate an optimized MRI-based strategy to assess gastric emptying and motility in healthy rats, paving the way for using this technique to understand GI diseases, or test new therapeutics in rat models.
Darwiche, Gassan; Björgell, Ola; Almér, Lars-olof
2003-01-01
Background Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal. Methods The viscosity of a basic test meal (300 g rice pudding, 330 kcal) was increased by adding Nestargel (6 g, 2.4 kcal), containing viscous dietary fibres (96.5%) provided as seed flour of locust bean gum, and decreased by adding 100 ml of water. Gastric emptying of these three test meals were evaluated in fifteen healthy non-smoking volunteers, using ultrasound measurements of the gastric antral area to estimate the gastric emptying rate (GER). Results The median value of GER with the basic test meal (rice pudding) was estimated at 63 %, (range 47 to 84 %), (the first quartile = 61 %, the third quartile = 69 %). Increasing the viscosity of the rice pudding by adding Nestargel, resulted in significantly lower gastric emptying rates (p < 0.01), median GER 54 %, (range 7 to 71 %), (the first quartile = 48 %, the third quartile = 60 %). When the viscosity of the rice pudding was decreased (basic test meal added with water), the difference in median GER 65 %, (range 38 to 79 %), (the first quartile = 56 %, the third quartile = 71 %) was not significantly different (p = 0.28) compared to the GER of the basic test meal. Conclusions We conclude that the addition of locust bean gum to a nutrient semisolid meal has a major impact on gastric emptying by delaying the emptying rate, but that the addition of water to this test meal has no influence on gastric emptying in healthy subjects. PMID:12793910
Darwiche, Gassan; Björgell, Ola; Almér, Lars-Olof
2003-06-06
Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal. The viscosity of a basic test meal (300 g rice pudding, 330 kcal) was increased by adding Nestargel (6 g, 2.4 kcal), containing viscous dietary fibres (96.5%) provided as seed flour of locust bean gum, and decreased by adding 100 ml of water. Gastric emptying of these three test meals were evaluated in fifteen healthy non-smoking volunteers, using ultrasound measurements of the gastric antral area to estimate the gastric emptying rate (GER). The median value of GER with the basic test meal (rice pudding) was estimated at 63%, (range 47 to 84%), (the first quartile = 61%, the third quartile = 69%). Increasing the viscosity of the rice pudding by adding Nestargel, resulted in significantly lower gastric emptying rates (p < 0.01), median GER 54%, (range 7 to 71%), (the first quartile = 48%, the third quartile = 60%). When the viscosity of the rice pudding was decreased (basic test meal added with water), the difference in median GER 65%, (range 38 to 79%), (the first quartile = 56%, the third quartile = 71%) was not significantly different (p = 0.28) compared to the GER of the basic test meal. We conclude that the addition of locust bean gum to a nutrient semisolid meal has a major impact on gastric emptying by delaying the emptying rate, but that the addition of water to this test meal has no influence on gastric emptying in healthy subjects.
Costello, M; Papasouliotis, K; Barr, F J; Gruffydd-Jones, T J; Caney, S M
1999-10-01
To use nuclear scintigraphy to establish a range of gastric emptying half times (t1/2) following a liquid or solid meal in nonsedated cats. 12 clinically normal 3-year-old domestic shorthair cats. A test meal of 75 g of scrambled eggs labeled with technetium Tc 99m tin colloid was fed to 10 of the cats, and solid-phase gastric emptying t1/2 were determined by use of nuclear scintigraphy. In a separate experiment, 8 of these cats plus an additional 2 cats were fed 18 ml (n = 5) or 36 ml (n = 5) of a nutrient liquid meal labeled with technetium Tc 99m pentetate. Liquid-phase gastric emptying t1/2 then were determined by use of scintigraphy. Solid-phase gastric emptying t1/2 were between 210 and 769 minutes (median, 330 minutes). Median liquid-phase gastric emptying t1/2 after ingestion of 18 or 36 ml of the test meal were 67 minutes (range, 60 to 96 minutes) and 117 minutes (range, 101 to 170 minutes), respectively. The median t1/2 determined for cats receiving 18 ml of the radiolabeled liquid was significantly less than that determined for cats receiving 36 ml of the test meal. The protocol was tolerated by nonsedated cats. Solid-phase gastric emptying t1/2 were prolonged, compared with liquid-phase t1/2, and a major factor governing the emptying rate of liquids was the volume consumed. Nuclear scintigraphy may prove useful in assessing gastric motility disorders in cats.
Correlation Between Gastric Emptying and Gastric Adaptive Relaxation Influenced by Amino Acids
Uchida, Masayuki; Kobayashi, Orie; Saito, Chizuru
2017-01-01
Background/Aims Amino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. Methods In Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-13C] acetic acid. The expired 13CO2 pattern, Tmax, Cmax, and AUC120min values were used as evaluation items. Gastric adaptive relaxation was evaluated in a barostat experiment. Individual amino acids (1 g/kg) were administered orally 30 minutes before each breath test or barostat test. Results L-phenylalanine and L-tyrosine did not influence gastric emptying. All other amino acids, ie, L-proline, L-histidine, L-cysteine, L-methionine, L-aspartic acid, L-glutamic acid, L-asparagine, L-arginine, L-glutamine, and L-lysine significantly delayed and inhibited gastric emptying. L-Cysteine and L-aspartic acid significantly enhanced and L-methionine and L-glutamine significantly inhibited gastric adaptive relaxation. L-Phenylalanine moved the balloon toward the antrum, suggesting strong contraction of the fundus. Tmax showed a significant positive correlation (r = 0.709), and Cmax and AUC120min each showed negative correlations (r = 0.613 and 0.667, respectively) with gastric adaptive relaxation. Conclusion From the above findings, it was found that a close correlation exists between gastric emptying and adaptive relaxation, suggesting that enhanced gastric adaptive relaxation inhibits gastric emptying. PMID:28335103
Li, D; Kong, Y; Yu, H; Lehtinen, A; Huang, H; Shen, F; Min, L; Zhou, J; Tang, G; Wang, Q
2008-04-01
A novel kind of non-viral gene delivery vector based on transferrin (Tf) as the core component was constructed with high transfection efficiency and low toxicity. The synthesis vector of Tf-PEI600 was confirmed by different physicochemical methods, including (1)H nuclear magnetic resonance, gel permeation chromatography, X-ray and thermogravimetric analysis. The cytotoxicity and gene delivery efficiency of the synthesized vector were verified by in vitro experiments. The agarose gel electrophoresis assay indicated that the novel copolymer Tf-PEI600 could efficiently condense plasmid DNA and the condensed nanoparticles exhibited a spherical shape. As the weight ratio of Tf-PEI600 to DNA reached 15.0, the particle size (about 200 nm) and the zeta potential (about 20 mV) of the nanoparticles became optimal for gene delivery. The methylthiazolyl tetrazolium (MTT) assay showed the cytotoxicity of Tf-PEI600 to be similar to that of PEI600 and much lower than that of PEI25kDa. In gene-delivery experiments with COS-7 cells and HepG2 cells, the Tf-PEI600 showed about a 30- to 53-fold higher efficiency than PEI600 and nearly equal to that of PEI25kDa. These data suggest that Tf-PEI600, with the advantages of low toxicity and high gene-delivery efficiency, might have great prospects in the practice of gene delivery. The core-shell structure of Tf-PEI600 also provided a novel strategy for the construction of non-viral gene delivery vectors.
14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...
14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...
14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...
14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...
14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...
Why the self is empty. Toward a historically situated psychology.
Cushman, P
1990-05-01
This article presents a contextualized treatment of the current configuration of self, some of the pathologies that plague it, and the technologies that attempt to heal it. Of particular interest is the historical shift from the Victorian, sexually restricted self to the post-World War II empty self. The empty self is soothed and made cohesive by becoming "filled up" with food, consumer products, and celebrities. Its historical antecedents, economic constituents, and political consequences are the focus of this article. The two professions most responsible for healing the empty self, advertising and psychotherapy, find themselves in a bind: They must treat a psychological symptom without being able to address its historical causes. Both circumvent the bind by employing the life-style solution, a strategy that attempts to heal by covertly filling the empty self with the accoutrements, values, and mannerisms of idealized figures. This strategy solves an old problem but creates new ones, including an opportunity for abuse by exploitive therapists, cult leaders, and politicians. Psychology's role in constructing the empty self, and thus reproducing the current hierarchy of power and privilege, is examined.
Solid Test Meal to Measure the Gastric Emptying with Magnetogastrography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reynaga-Ornelas, M. G.; Roca-Chiapas, J. M. de ls; Cordova-Fraga, T.
2008-08-11
The gastric emptying is the time of evacuating the food ingested from the stomach to the duodenum in a controlled rate. Diverse studies express the results of the gastric emptying in form of half-time (t{sub 1/2}). The Magnetogastrography (MGG) is a biomagnetic technique that has the advantage of not being invasive, radiation free and does not interfere with the privacy of the subject. The objective was to analyze the magnetic signal of magnetic tracers mixed in a solid food to measure gastric emptying using Magnetogastrography. The ingested test meal displayed a magnetic signal, which served to obtain the signal registeredmore » by the fluxgate and the peristaltic contractions could be calculated while the stomach was emptying. The solid food product developed results to work satisfactorily in magnetogastrography.« less
Effect of synthetic prostaglandin E1 analog on gastric emptying of meals in man.
Moore, J G; Alazraki, N; Clay, G D
1986-01-01
Forty-five subjects with healed duodenal ulcer were administered either a placebo or a low-dose or high-dose regimen of misoprostol, a synthetic PGE1 analog, in a double-blind, random, parallel-group design to assess the effect of this prostaglandin compound on the gastric emptying of liquid-solid meals. A dual-radionuclide technique to measure liquid- and solid-phase gastric emptying rates of physiological meals by external gamma camera imaging was used. All subjects had a pretreatment control (baseline) evaluation, followed one week later by a treatment-influenced emptying study. The results demonstrated that misoprostol did not significantly alter gastric emptying of either liquids or solids; however, these results cannot be extrapolated to other prostaglandin compounds because of the diverse and sometimes paradoxical effects of different prostaglandins on gastric motility.
Nonaka, Takashi; Kessoku, Takaomi; Ogawa, Yuji; Yanagisawa, Shogo; Shiba, Tadahiko; Sahaguchi, Takashi; Atsukawa, Kazuhiro; Takahashi, Hisao; Sekino, Yusuke; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Sakamoto, Yasunari; Koide, Tomoko; Takahashi, Hirokazu; Tokoro, Chikako; Abe, Yasunobu; Maeda, Shin; Nakajima, Atsushi; Inamori, Masahiko
2011-01-01
The aim of this study was to determine whether oral Itopride hydrochloride (itopride) intake might have any effect on the rate of gastric emptying, using a novel non-invasive technique for measuring the rate of gastric emptying, namely, the continuous real time 13C breath test (BreathID system: Exalenz Bioscience Ltd., Israel). Eight healthy male volunteers participated in this randomized, two-way crossover study. The subjects fasted overnight and were randomly assigned to receive 50mg itopride following a test meal (200 kcal per 200mL, containing 100mg 13C acetate), or the test meal alone. Under both conditions, gastric emptying was monitored for 4 hours after administration of the test meal by the 13C-acetic acid breath test performed continually using the BreathID system. Using Oridion Research Software (beta version), the time required for emptying of 50% of the labeled meal (T 1/2), the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T lag), the gastric emptying coefficient (GEC), and the regression-estimated constants (beta and kappa) were calculated. The parameters measured under the two conditions were compared using the Wilcoxon's signed-rank test. No significant differences in the calculated parameters, namely, the T 1/2, T lag, GEC, beta or kappa, were observed between the two test conditions, namely, administration of a test meal+itopride and administration of the test meal alone. The present study revealed that postprandial itopride intake had no significant influence on the rate of gastric emptying. Recently, several studies have shown that itopride may be effective in the treatment of patients with functional dyspepsia. Our results suggest that the efficacy of itopride in patients with functional dyspepsia may be based on its effect of improving functions other than the rate of gastric emptying, such as the activities at neuronal sites, brain-gut correlation, visceral hypersensitivity, gastric accommodation and distension-induced adaptation.
Bavestrello, L; Caimi, L; Barbera, A
1985-01-01
Seventy-six patients suffering from dyspeptic symptoms secondary to roentgenologically demonstrated delayed gastric emptying were treated with clebopride (0.5 mg TID) or with placebo during a three-month double-blind trial. Clebopride was more effective (P less than or equal to 0.001) than placebo in reducing or relieving symptoms and roentgenological findings associated with delayed gastric emptying. No interactions of clebopride with concomitant drugs or coexisting disorders were observed, and the incidence of side effects was low. We conclude that clebopride will be beneficial in the management of patients with delayed gastric emptying.
Gastric emptying and intragastric distribution of lipids in man. A new scintigraphic method of study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jian, R.; Vigneron, N.; Najean, Y.
1982-08-01
We measured gastric emptying of fat and water from a solid-liquid meal in healthy volunteers using a tubeless scintigraphic method. /sup 75/Se glycerol triether, incorporated in butter, was the lipid-phase marker, and /sup 99m/Tcm, ingested with 250 ml water, the non-lipid phase marker. In seven of these subjects we also measured the gastric emptying of solids and liquids with /sup 99m/Tc bound to cooked egg whites as the solid-phase marker and /sup 111/In ingested with 250 ml water as the marker of the solid and aqueous phases. Emptying and intragastric repartition of each marker were measured by detection of radioactivitymore » changes over the abdominal area using a gamma-camera. The stability and the specificity of the labeling was checked for each marker. Mean gastric emptying rate (expressed as percentage ingested marker emptied per hr) of lipids (17.4 +/- 2.4) was much lower than that of the rest of the meal (34.2 +/- 1.8) and slightly, but significantly, lower than that of solids (22.8 +/- 1.8). An intragastric layering of fat above nonlipids was observed only after the first postprandial hour and remained moderate. Thus, lipids are emptied more slowly than any other component of an ordinary meal, and this is not due only to layering of fat above water.« less
Empty Tissue Boxes: Considering Poverty in Diversity Discourse
ERIC Educational Resources Information Center
Cuthrell, Kristen; Ledford, Carolyn; Stapleton, Joy
2007-01-01
A preservice teacher doing her internship overhears some of her students asking a classmate why he regularly takes home empty tissue boxes. The boy replies that he builds cities and bridges with his empty boxes. His classmates then ask why he does not just build a city with Legos or building blocks. The preservice teacher listens intently as the…
Affordable Housing and the Empty Nester Boom.
ERIC Educational Resources Information Center
Hare, Patrick H.
One of the best ways to produce affordable housing is to address the needs of a group that has too much housing. A baby boom generation generates an empty nester boom. An empty nester boom means dramatic underutilization of the housing stock. If a small percentage of homeowners were to install an accessory apartment, they would have a significant…
21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.
Code of Federal Regulations, 2010 CFR
2010-04-01
... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...
21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.
Code of Federal Regulations, 2012 CFR
2012-04-01
... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...
21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.
Code of Federal Regulations, 2011 CFR
2011-04-01
... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...
21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.
Code of Federal Regulations, 2014 CFR
2014-04-01
... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...
21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.
Code of Federal Regulations, 2013 CFR
2013-04-01
... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...
Impaired Performance of Right-Brain-Damaged Patients on a Sentence Anagram Task
ERIC Educational Resources Information Center
Murasugi, K.; Schneiderman, E.
2005-01-01
A sentence anagram task was used to examine the right cerebral hemispheres's role in core grammatical functioning at the syntactic level. The test consisted of two subsets of stimuli involving empty categories: (a) those that required the empty category to be filled, and (b) those that allowed the category to remain empty. Three hypotheses were…
Marathe, Chinmay S; Rayner, Christopher K; Lange, Kylie; Bound, Michelle; Wishart, Judith; Jones, Karen L; Kahn, Steven E; Horowitz, Michael
2017-02-01
The oral disposition index, the product of the early insulin secretory response during an oral glucose tolerance test and insulin sensitivity, is used widely for both the prediction of, and evaluation of the response to interventions, in type 2 diabetes. Gastric emptying, which determines small intestinal exposure of nutrients, modulates postprandial glycemia. The aim of this study was to determine whether the insulin secretory response and the disposition index (DI) related to gastric emptying in subjects with normal glucose tolerance. Thirty-nine subjects consumed a 350 mL drink containing 75 g glucose labeled with 99m Tc-sulfur colloid. Gastric emptying (by scintigraphy), blood glucose (G) and plasma insulin (I) were measured between t = 0-120 min. The rate of gastric emptying was derived from the time taken for 50% emptying ( T 50 ) and expressed as kcal/min. The early insulin secretory response was estimated by the ratio of the change in insulin (∆I 0-30 ) to that of glucose at 30 min (∆G 0-30 ) represented as ∆I 0-30 /∆G 0-30 Insulin sensitivity was estimated as 1/fasting insulin and the DI was then calculated as ∆I 0-30 /∆G 0-30 × 1/fasting insulin. There was a direct relationship between ∆G 0-30 and gastric emptying ( r = 0.47, P = 0.003). While there was no association of either ∆I 0-30 ( r = -0.16, P = 0.34) or fasting insulin ( r = 0.21, P = 0.20), there were inverse relationships between the early insulin secretory response ( r = -0.45, P = 0.004) and the DI ( r = -0.33, P = 0.041), with gastric emptying. We conclude that gastric emptying is associated with both insulin secretion and the disposition index in subjects with normal glucose tolerance, such that when gastric emptying is relatively more rapid, both the early insulin secretory response and the disposition index are less. These findings should be interpreted as "hypothesis generating" and provide the rationale for longitudinal studies to examine the impact of baseline rate of gastric emptying on the prospective risk of type 2 diabetes. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.
Somasundaram, Vijay Harish; Subramanyam, Padma; Palaniswamy, Shanmuga Sundaram
2014-11-01
The aim of this study was to describe the preparation of radiolabeled idli (savory cake) meal for use as an alternate to the egg white sandwich (EWS) meal in gastric emptying scintigraphy (GES). Furthermore, the aim of this study was to establish normal emptying rates for this meal and present our experience in using it in the evaluation of diabetic gastroparesis. The meal was prepared using a universally available packaged mix labeled with 1 mCi 99mTc sulfur colloid, and the stability of labeling was tested up to 4 hours in simulated gastric fluid. One hundred thirteen healthy volunteers (aged 20-78 years; 54 women, 59 men) underwent GES study using the idli meal. Gastric retention at one-half, 1, 2, and 4 hours after ingestion of the meal was estimated, and the normal limits were set using the fifth and 95th percentile values at each period. Having established its normal emptying rates, the idli meal was further used to evaluate 70 patients suspected with diabetic gastroparesis. The idli meal, with a calorific value ≈282 kcal, has a relatively higher fat content (8% of total mass) than EWS. More than 96% of 99mTc sulfur colloid remained bound to the meal after 4 hours suspension in simulated gastric fluid. Gastric retention greater than 30% and greater than 6% at 2 hours and 4 hours, respectively, indicated delayed gastric emptying, whereas retention less than 30% at 1 hour suggested rapid emptying. Among patients suspected with diabetic gastroparesis, delayed gastric emptying was identified in 76%, and rapid emptying was seen in 4.2%. Radiolabeled idli meal is a good alternative to EWS meal for routine GES, especially among patients with specific dietary restrictions.
Hirata, Takuya; Keto, Yoshihiro; Yamano, Mayumi; Yokoyama, Toshihide; Sengoku, Takanori; Seki, Nobuo
2012-09-01
Symptoms of functional dyspepsia (FD) are highly prevalent in patients with irritable bowel syndrome (IBS). However, the effects of therapeutic agents for IBS on the pathophysiology of FD are unclear. In this study, therefore, we examined the effects of ramosetron, a serotonin 5-HT(3) receptor antagonist, on corticotropin releasing factor (CRF)- and soybean oil-induced delays in gastric emptying of rats, in comparison with anti-diarrheal agent and spasmolytics. The involvement of 5-HT and the 5-HT(3) receptor in delayed gastric emptying was also evaluated. Corticotropin releasing factor was administered intravenously to rats 10min before oral administration of 0.05% phenol red solution, and the amount remaining in the stomach was measured after 30min. Soybean oil was administered orally with glass beads, and the number of residual beads in the stomach was counted 1h later. Both CRF and soybean oil inhibited gastric emptying dose-dependently. Ramosetron and itopride, a gastro-prokinetic agent, significantly reduced both CRF- and soybean oil-induced delays in gastric emptying, while an anti-diarrheal agent and spasmolytics aggravated them. Pretreatment with p-chlorophenylalanine for 2days to reduced the synthesis of endogenous 5-HT diminished the effects of both CRF and soybean oil on gastric emptying. A 5-HT(3) receptor agonist m-chlorophenylbiguanide suppressed gastric emptying of both phenol red and glass beads, and those effects were reversed by ramosetron. These results suggest that CRF and soybean oil suppress gastric emptying in rats by activating 5-HT(3) receptors, and that by antagonizing these receptors, ramosetron may ameliorate symptoms of FD in clinical settings. © 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.
A central site of action for benzamide facilitation of gastric emptying.
Costall, B; Gunning, S J; Naylor, R J; Simpson, K H
1983-07-22
Gastric emptying of the fed guinea-pig was measured using a non-invasive X-ray fluoroscopic technique to determine passage from the stomach of polystyrene-coated barium sulphate spheroids. Peripherally administered metoclopramide (0.1-10 mg/kg i.p.), clebopride (1-10 mg/kg i.p.), (-)-sulpiride (40 mg/kg i.p.), haloperidol (1 mg/kg i.p.) and domperidone (1-10 mg/kg i.p.) failed to modify gastric emptying. Stress inhibited emptying, and this was considered to explain the effects of eserine and high dose metoclopramide. Gastric emptying was decreased by peripherally administered atropine (0.5 mg/kg i.p.) and apomorphine (0.1-0.5 mg/kg s.c.); the apomorphine response was antagonised by pretreatment with haloperidol, domperidone, (-)-sulpiride, metoclopramide and clebopride but not by prazosin + propranolol. Gastric emptying was facilitated by intracerebroventricular (i.c.v.) administrations of metoclopramide and clebopride (40, 100 and 200 micrograms) but not by i.c.v. domperidone, haloperidol, fluphenazine or (-)-sulpiride (100, 200 micrograms) and was inhibited by i.c.v. apomorphine (100, 200 micrograms); the response to i.c.v. apomorphine was antagonised by i.c.v. pretreatments with haloperidol, domperidone, (-)-sulpiride, metoclopramide and clebopride (40-50 micrograms). Facilitation of emptying by i.c.v. metoclopramide was prevented by peripheral pretreatment with atropine (0.5 mg/kg i.p.). It is concluded that the actions of apomorphine and metoclopramide/clebopride to respectively inhibit and facilitate gastric emptying may be mediated, at least in part, via central mechanisms. Whilst apomorphine's action may be mediated via dopamine receptor mechanisms, metoclopramide and clebopride act at additional unspecified sites, metoclopramide's action being expressed via cholinergic mechanisms.
Cisse, Fatimata; Pletsch, Elizabeth A; Erickson, Daniel P; Chegeni, Mohammad; Hayes, Anna M R; Hamaker, Bruce R
2017-09-01
Gastric emptying rate influences how fast the nutrients of a meal are delivered to the body, and when slow, it moderates glycemic response and may impact satiety. Carbohydrates are one of the macronutrients that trigger the ileal brake, and we hypothesized that slowly digestible carbohydrate (SDC) administered in a premeal load would delay gastric emptying. A crossover design study was conducted with 10 healthy adults using fabricated SDC-microspheres (cooked) that were given 20 minutes before a non-nutritive viscous paste meal. There were 4 treatment arms, each separated by a 1-week washout period, consisting of (1) the paste alone, (2) a rapidly digesting maltodextrin (Polycose) preload followed by the paste 20 minutes later, (3) an SDC-microsphere preload followed by the paste, and (4) a comparably slower SDC-microsphere preload followed by the paste. A 13 C-labeled octanoic acid breath test method was used to measure gastric emptying, with the label incorporated into the non-nutritive paste. The microspheres were less than 1 mm in diameter (a size that does not require breakdown in the stomach before emptying) and, after cooking, were of the same density value. Compared with the paste alone, both of the SDC-microsphere preloads (slow and comparably slower digesting) decreased gastric emptying rate of the paste, with the latter having the most effect (half-emptying times of 1.7, 2.3, and 2.8 hours, respectively [each different at P<.05]). In conclusion, SDCs decreased gastric emptying rate, and this was suggested to be due to a triggering of the ileal brake. Copyright © 2017 Elsevier Inc. All rights reserved.
Exercise and training effects on gastric emptying of carbohydrate beverages.
Rehrer, N J; Beckers, E; Brouns, F; Hoor ten, F; Saris, W H
1989-10-01
Carbohydrate containing drinks are commonly consumed as an ergogenic aid during endurance sports activities. The efficacy of a given drink is limited by the rate of absorption, which is in turn limited by gastric emptying. A myriad of factors influence gastric emptying. The influence of several of these factors (training status, exercise intensity, and carbohydrate composition) was investigated by repeated experiments using a nasogastric tube and a modification of the technique of George. A group of well-trained bicyclists and a group of untrained subjects performed similar experiments. Three different carbohydrate containing drinks (15 g.100 ml-1 glucose (G), 15 g.100 ml-1 maltodextrin plus 3 g.100 ml-1 fructose (MD), 7 g.100 ml-1 sucrose (I] and artificially sweetened water were compared during rest and 50 and 70% Wmax bicycling. Experimental design was crossover. There was a trend for the carbohydrate drinks to empty initially more slowly under the influence of exercise. Differences in drink volume remaining in the stomach were significant (P less than 0.05), with I at 10 min (70%, mean = 48.9%; rest, mean = 30.5%) and at 20 min (70%, mean = 28.9%; rest, mean = 23.8%) and with MD at 10 min (70%, mean = 71.1%; rest, mean = 55.9%). A similar trend was also seen with 50% Wmax exercise; however, this trend was only significant with MD at 10 min (50%, mean = 72.1%; rest, mean = 55.9%). Drink composition was a much stronger inhibitor of gastric emptying. However, all drinks emptied exponentially with fast-phase initial emptying rates. No differences in gastric emptying or secretion were observed between trained and untrained subjects.
Gastric emptying of enteric-coated tablets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, H.M.; Chernish, S.M.; Rosenek, B.D.
1984-03-01
To evaluate the gastric emptying time of pharmaceutical dosage forms in a clinical setting, a relatively simple dual-radionuclide technique was developed. Placebo tablets of six different combinations of shape and size were labeled with indium-111 DTPA and enteric coated. Six volunteers participated in a single-blind and crossover study. Tablets were given in the morning of a fasting stomach with 6 oz of water containing /sup 99m/Tc pertechnetate and continuously observed with a gamma camera. A scintigraph was obtained each minute. The results suggested that the size, shape, or volume of the tablet used in this study had no significant effectmore » in the rate of gastric emptying. The tablets emptied erratically and unpredictably, depending upon their time of arrival in the stomach in relation to the occurrence of interdigestive myoelectric contractions. The method described is a relatively simple and accurate technique to allow one to follow the gastric emptying of tablets.« less
Empty tracks optimization based on Z-Map model
NASA Astrophysics Data System (ADS)
Liu, Le; Yan, Guangrong; Wang, Zaijun; Zang, Genao
2017-12-01
For parts with many features, there are more empty tracks during machining. If these tracks are not optimized, the machining efficiency will be seriously affected. In this paper, the characteristics of the empty tracks are studied in detail. Combining with the existing optimization algorithm, a new tracks optimization method based on Z-Map model is proposed. In this method, the tool tracks are divided into the unit processing section, and then the Z-Map model simulation technique is used to analyze the order constraint between the unit segments. The empty stroke optimization problem is transformed into the TSP with sequential constraints, and then through the genetic algorithm solves the established TSP problem. This kind of optimization method can not only optimize the simple structural parts, but also optimize the complex structural parts, so as to effectively plan the empty tracks and greatly improve the processing efficiency.
Intracellular localization of adeno-associated viral proteins expressed in insect cells.
Gallo-Ramírez, Lilí E; Ramírez, Octavio T; Palomares, Laura A
2011-01-01
Production of vectors derived from adeno-associated virus (AAVv) in insect cells represents a feasible option for large-scale applications. However, transducing particles yields obtained in this system are low compared with total capsid yields, suggesting the presence of genome encapsidation bottlenecks. Three components are required for AAVv production: viral capsid proteins (VP), the recombinant AAV genome, and Rep proteins for AAV genome replication and encapsidation. Little is known about the interaction between the three components in insect cells, which have intracellular conditions different to those in mammalian cells. In this work, the localization of AAV proteins in insect cells was assessed for the first time with the purpose of finding potential limiting factors. Unassembled VP were located either in the cytoplasm or in the nucleus. Their transport into the nucleus was dependent on protein concentration. Empty capsids were located in defined subnuclear compartments. Rep proteins expressed individually were efficiently translocated into the nucleus. Their intranuclear distribution was not uniform and differed from VP distribution. While Rep52 distribution and expression levels were not affected by AAV genomes or VP, Rep78 distribution and stability changed during coexpression. Expression of all AAV components modified capsid intranuclear distribution, and assembled VP were found in vesicles located in the nuclear periphery. Such vesicles were related to baculovirus infection, highlighting its role in AAVv production in insect cells. The results obtained in this work suggest that the intracellular distribution of AAV proteins allows their interaction and does not limit vector production in insect cells. Copyright © 2011 American Institute of Chemical Engineers (AIChE).
Differing Interpretations of Empty Categories in English and Japanese VP Ellipsis Contexts
ERIC Educational Resources Information Center
Matsuo, Ayumi
2007-01-01
This article describes how English and Japanese children interpret empty categories in Verb Phrase Ellipsis contexts as in (1):(1) The penguin [sat on his chair] and the robot did [delta], too. To obtain an adultlike interpretation of (1), English children have to do two things. First, they need to find a suitable antecedent for the empty verb…
Method for the quantitation of gastric emptying time of gel test meals.
Russell, J; Bass, P
1984-09-01
Isotopic markers were developed to allow measurement of the gastric emptying times of homogeneous and nonhomogeneous gel meals. Meals containing the dietary fibers psyllium and guar gum presented as homogeneous, viscous gels while meals containing the synthetic polymer polycarbophil presented as discrete gel particle-water mixtures. Fiber meals were labeled differently than polycarbophil meals. Fiber meals were labeled with 51Cr-CM-Sephadex. The marker was uniformly suspended in meals containing at least 1% guar or 2% psyllium. In contrast, polycarbophil particles were labeled by hydrating the dried granules with saline in which Na2(51)CrO4 had been dissolved. Use of the markers to measure gastric emptying was demonstrated in dogs fitted with duodenal cannulas. Half of the fiber meals emptied from the stomach in about 40 min without significant dilution by secretions. In contrast, only 8% of the polycarbophil particles emptied by 90 min. Particle-specific labeling of polycarbophil was important because the meal effluent was diluted extensively by secretions. We conclude that 51Cr-CM-Sephadex and soluble Cr-51 may be used as meal markers for estimation of the gastric emptying times of certain homogeneous and nonhomogeneous gel-type meals, respectively.
Gallbladder emptying to endogenous and exogenous stimulation in chronic pancreatitis patients.
Meguro, T; Shimosegawa, T; Kashimura, J; Kikuchi, Y; Koizumi, M; Toyota, T
1994-02-01
The present study was designed to analyze the underlying mechanism of gallbladder motor disturbance in chronic pancreatitis patients. Gallbladder emptying to endogenous (oral test meal, Daiyan 13 g) and exogenous stimulation (iv cerulein, 30 ng/kg for 5 min) was examined by real-time ultrasonography in 12 patients with chronic pancreatitis and 10 normal subjects (controls). Plasma cholecystokinin levels during the endogenous stimulation were measured by bioassay. In chronic pancreatitis patients compared with controls, the fasting gallbladder volume was significantly increased (29.5 +/- 2.2 vs. 21.5 +/- 2.8 ml), whereas the gallbladder emptying (percent change of the basal volume) to oral test meal was significantly decreased. Neither cholecystokinin secretion induced by the test meal, nor the gallbladder emptying response to intravenous cerulein, differed significantly between the two groups. However, when chronic pancreatitis patients were divided according to pathogenesis, it became clear that gallbladder emptying to intravenous cerulein was significantly greater in patients with alcoholic chronic pancreatitis than in patients with idiopathic pancreatitis. Gallbladder emptying during the intestinal phase is generally reduced in patients with chronic pancreatitis, but gallbladder responsiveness to exogenous stimulation might be heterogeneous according to the pathogenesis.
The Alphavirus Exit Pathway: What We Know and What We Wish We Knew
2018-01-01
Alphaviruses are enveloped positive sense RNA viruses and include serious human pathogens, such as the encephalitic alphaviruses and Chikungunya virus. Alphaviruses are transmitted to humans primarily by mosquito vectors and include species that are classified as emerging pathogens. Alphaviruses assemble highly organized, spherical particles that bud from the plasma membrane. In this review, we discuss what is known about the alphavirus exit pathway during a cellular infection. We describe the viral protein interactions that are critical for virus assembly/budding and the host factors that are involved, and we highlight the recent discovery of cell-to-cell transmission of alphavirus particles via intercellular extensions. Lastly, we discuss outstanding questions in the alphavirus exit pathway that may provide important avenues for future research. PMID:29470397
Packaging stiff polymers in small containers: A molecular dynamics study
NASA Astrophysics Data System (ADS)
Rapaport, D. C.
2016-09-01
The question of how stiff polymers are able to pack into small containers is particularly relevant to the study of DNA packaging in viruses. A reduced version of the problem based on coarse-grained representations of the main components of the system—the DNA polymer and the spherical viral capsid—has been studied by molecular dynamics simulation. The results, involving longer polymers than in earlier work, show that as polymers become more rigid there is an increasing tendency to self-organize as spools that wrap from the inside out, rather than the inverse direction seen previously. In the final state, a substantial part of the polymer is packed into one or more coaxial spools, concentrically layered with different orientations, a form of packaging achievable without twisting the polymer.
Cisse, Fatimata; Erickson, Daniel P; Hayes, Anna M R; Opekun, Antone R; Nichols, Buford L; Hamaker, Bruce R
2018-01-26
From anecdotal evidence that traditional African sorghum and millet foods are filling and provide sustained energy, we hypothesized that gastric emptying rates of sorghum and millet foods are slow, particularly compared to non-traditional starchy foods (white rice, potato, wheat pasta). A human trial to study gastric emptying of staple foods eaten in Bamako, Mali was conducted using a carbon-13 ( 13 C)-labelled octanoic acid breath test for gastric emptying, and subjective pre-test and satiety response questionnaires. Fourteen healthy volunteers in Bamako participated in a crossover design to test eight starchy staples. A second validation study was done one year later in Bamako with six volunteers to correct for endogenous 13 C differences in the starches from different sources. In both trials, traditional sorghum and millet foods (thick porridges and millet couscous) had gastric half-emptying times about twice as long as rice, potato, or pasta ( p < 0.0001). There were only minor changes due to the 13 C correction. Pre-test assessment of millet couscous and rice ranked them as more filling and aligned well with postprandial hunger rankings, suggesting that a preconceived idea of rice being highly satiating may have influenced subjective satiety scoring. Traditional African sorghum and millet foods, whether viscous in the form of a thick porridge or as non-viscous couscous, had distinctly slow gastric emptying, in contrast to the faster emptying of non-traditional starchy foods, which are popular among West African urban consumers.
Cisse, Fatimata; Erickson, Daniel P.; Hayes, Anna M. R.; Opekun, Antone R.; Nichols, Buford L.; Hamaker, Bruce R.
2018-01-01
From anecdotal evidence that traditional African sorghum and millet foods are filling and provide sustained energy, we hypothesized that gastric emptying rates of sorghum and millet foods are slow, particularly compared to non-traditional starchy foods (white rice, potato, wheat pasta). A human trial to study gastric emptying of staple foods eaten in Bamako, Mali was conducted using a carbon-13 (13C)-labelled octanoic acid breath test for gastric emptying, and subjective pre-test and satiety response questionnaires. Fourteen healthy volunteers in Bamako participated in a crossover design to test eight starchy staples. A second validation study was done one year later in Bamako with six volunteers to correct for endogenous 13C differences in the starches from different sources. In both trials, traditional sorghum and millet foods (thick porridges and millet couscous) had gastric half-emptying times about twice as long as rice, potato, or pasta (p < 0.0001). There were only minor changes due to the 13C correction. Pre-test assessment of millet couscous and rice ranked them as more filling and aligned well with postprandial hunger rankings, suggesting that a preconceived idea of rice being highly satiating may have influenced subjective satiety scoring. Traditional African sorghum and millet foods, whether viscous in the form of a thick porridge or as non-viscous couscous, had distinctly slow gastric emptying, in contrast to the faster emptying of non-traditional starchy foods, which are popular among West African urban consumers. PMID:29373493
Gastric emptying 16 to 26 years after treatment of infantile hypertrophic pyloric stenosis.
Lüdtke, F E; Bertus, M; Voth, E; Michalski, S; Lepsien, G
1994-04-01
Long-term follow-up was performed 16 to 26 years after conservative (group I, n = 18) and operative (group II, n = 38) treatment of 56 patients who had infantile hypertrophic pyloric stenosis (IHPS). The study encompassed the scintigraphic determination of gastric emptying rates for solids and liquids, an interview to obtain medical history and ascertain whether a current disorder of the upper gastrointestinal tract was present, and a clinical examination. Gastric emptying rates were measured on two different days for solids and liquids. The standard solid meal consisted of two scrambled eggs, two slices of toast, and 20 g of margarine. The gastric emptying rate for liquids was measured using 300 mL of apple juice. The scrambled eggs and apple juice were each marked with 2.2 MBq technetium 99m-sulphur-colloid. Two control collectives were used in this study; one group (physicians) served to create a reference curve for gastric emptying, and the other group, with the same age and gender distributions as those of the patients, served to evaluate the frequency of gastrointestinal complaints, by means of a questionnaire. There was no significant rate difference for gastric emptying between the patients treated conservatively or surgically and the controls. No association could be construed between the frequency of gastrointestinal symptoms or disorders and the gastric emptying rates for solids and liquids. The results presented here substantiate that clinically relevant disturbances of stomach motility after IHPS appear to be rare.
Brown rice compared to white rice slows gastric emptying in humans.
Pletsch, Elizabeth A; Hamaker, Bruce R
2018-03-01
Consumption of whole vs. refined grain foods is recommended by nutrition or dietary guideline authorities of many countries, yet specific aspects of whole grains leading to health benefits are not well understood. Gastric emptying rate is an important consideration, as it is tied to nutrient delivery rate and influences glycemic response. Our objective was to explore two aspects of cooked rice related to gastric emptying, (1) whole grain brown vs. white rice and (2) potential effect of elevated levels of slowly digestible starch (SDS) and resistant starch (RS) from high-amylose rice. Ten healthy adult participants were recruited for a crossover design study involving acute feeding and testing of 6 rice samples (50 g available carbohydrate). Gastric emptying rate was measured using a 13 C-labeled octanoic acid breath test. A rice variety (Cocodrie) with high-amylose content was temperature-cycled to increase SDS and RS fractions. In vitro starch digestibility results showed incremental increase in RS in Cocodrie after two temperature cycles. For low-amylose varieties, SDS was higher in the brown rice form. In human subjects, low-amylose and high-amylose brown rice delayed gastric emptying compared to white rices regardless of amylose content or temperature-cycling (p < 0.05). Whole grain brown rice had slower gastric emptying rate, which appears to be related to the physical presence of the bran layer. Extended gastric emptying of brown rice explains in part comparably low glycemic response observed for brown rice.
NASA Astrophysics Data System (ADS)
Plascencia-Villa, Germán; Carreño-Fuentes, Liliana; Bahena, Daniel; José-Yacamán, Miguel; Palomares, Laura A.; Ramírez, Octavio T.
2014-09-01
New technologies require the development of novel nanomaterials that need to be fully characterized to achieve their potential. High-resolution low-voltage scanning transmission electron microscopy (STEM) has proven to be a very powerful technique in nanotechnology, but its use for the characterization of nanobiomaterials has been limited. Rotavirus VP6 self-assembles into nanotubular assemblies that possess an intrinsic affinity for Au ions. This property was exploited to produce hybrid nanobiomaterials by the in situ functionalization of recombinant VP6 nanotubes with gold nanoparticles. In this work, Raman spectroscopy and advanced analytical electron microscopy imaging with spherical aberration-corrected (Cs) STEM and nanodiffraction at low-voltage doses were employed to characterize nanobiomaterials. STEM imaging revealed the precise structure and arrangement of the protein templates, as well as the nanostructure and atomic arrangement of gold nanoparticles with high spatial sub-Angstrom resolution and avoided radiation damage. The imaging was coupled with backscattered electron imaging, ultra-high resolution scanning electron microscopy and x-ray spectroscopy. The hybrid nanobiomaterials that were obtained showed unique properties as bioelectronic conductive devices and showed enhanced Raman scattering by their precise arrangement into superlattices, displaying the utility of viral assemblies as functional integrative self-assembled nanomaterials for novel applications.
Self consistent field theory of virus assembly
NASA Astrophysics Data System (ADS)
Li, Siyu; Orland, Henri; Zandi, Roya
2018-04-01
The ground state dominance approximation (GSDA) has been extensively used to study the assembly of viral shells. In this work we employ the self-consistent field theory (SCFT) to investigate the adsorption of RNA onto positively charged spherical viral shells and examine the conditions when GSDA does not apply and SCFT has to be used to obtain a reliable solution. We find that there are two regimes in which GSDA does work. First, when the genomic RNA length is long enough compared to the capsid radius, and second, when the interaction between the genome and capsid is so strong that the genome is basically localized next to the wall. We find that for the case in which RNA is more or less distributed uniformly in the shell, regardless of the length of RNA, GSDA is not a good approximation. We observe that as the polymer-shell interaction becomes stronger, the energy gap between the ground state and first excited state increases and thus GSDA becomes a better approximation. We also present our results corresponding to the genome persistence length obtained through the tangent-tangent correlation length and show that it is zero in case of GSDA but is equal to the inverse of the energy gap when using SCFT.
[Panhypopituitarism and dwarfism in a man with a primary empty sella turcica (author's transl)].
Turpin, G; Jambart, S; de Gennes, J L
1979-03-10
Endocrine features associated with the primary empty sella turcica syndrom are rare; they are usually related to a pituitary microadenoma and more rarely to an idiopathic panhypop ituitarism. A pituitary dwarfism with an idiopathic panhypopituitarism of hypothalamic origin, associated with an "empty" sella turcica containing functional and stimulable pituitary tissue, is reported in a 27 year old male Moraccan.
[Gastric emptying of a solid-liquid meal in gastroesophageal reflux in adults].
Bost, R; Hostein, J; Gignoux, C; Busquet, G; Lachet, B; Fournet, J
1986-04-01
Several studies concerning the relationships between gastroesophageal reflux (GOR), gastric emptying and esophageal motility are available. So far, results have been contradictory. The purpose of this work was to study gastric emptying in patients with GOR; to search for simultaneous esophageal motility disorders and to specify their type and frequency; to establish a potential relationship between motor disorders of the esophagus and the stomach in these patients. Thirty-two consecutive patients were selected according to clinical criteria, i.e. presence of at least two of the three characteristic symptoms of GOR, and the data of a three-hour post-prandial pH-metry. Gastric stasis related clinical manifestations (nausea, post-prandial vomiting, sensation of abdominal distension or of post-prandial epigastric fullness) were also searched for in all patients. A gastroscopy allowed to score esophagitis in each case. All patients, including adult controls underwent an esophageal manometry as well as a radionuclide determination of gastric emptying, after isotopic labelling of the solid (S) and liquid (L) phases of a test meal. The results showed that there was no significant modification of gastric emptying of the S and L phases of the meal in the group of patients with GOR whatever the intensity of the reflux, judged on the pH-metry results and the endoscopic data. Thus the average time of gastric half-emptying of S and L was respectively 115 and 52 min for the patients vs 111 and 51 min for the control group. As well, no correlation was found between the gastric emptying parameters and the presence or absence of clinical signs of gastric stasis or the amplitude of esophageal contraction waves. On an individual basis, two patients showed a significant decrease in gastric emptying of either the S or L phases without any attendant modification in the kinetics of the other. These results suggest that, in the adult, gastric emptying cannot be considered to be a determining factor of GOR and there are no diffuse motility disorders of the upper digestive tract during this illness.
HIV-Positive Mothers With Late Adolescent/Early Adult Children: “Empty Nest” Concerns
Murphy, Debra A.; Roberts, Kathleen Johnston; Herbeck, Diane M.
2012-01-01
In-depth interviews about the “empty nest” were conducted with 57 HIV-positive mothers of late adolescent/early adult children. Empty nest worries included: (1) identity loss, (2) loss of social support, (3) financial insecurity, (4) worsening of physical health, and (5) death/dying. Hopes included: (1) self-improvement, (2) change of life focus, (3) travel, (4) romantic partners, and (5) familial ties. Respondents’ HIV/AIDS status colored their thoughts/feelings about the empty nest; some worries were specific to being HIV-positive, and would not occur for non-ill mothers. Midlife HIV positive women need healthcare/social service resources as they navigate health and social-psychological challenges to successful aging. PMID:22420679
Raman-based Oxygen and Nitrogen Sensor for Monitoring Empty Airplane Fuel Tanks
NASA Technical Reports Server (NTRS)
Chen, Peter C.
2004-01-01
The purpose of this project was to develop a Raman-based method for detecting oxygen and nitrogen in empty fuel tanks. The need for such a method comes from the potential danger of allowing explosive oxygen-fuel mixtures to accumulate in empty airplane fuel tanks. An explosion resulting from such a mixture is believed to have caused the Flight TWA 800 disaster in 1996. Recently, (e.g., February 17,2004 press release) the FAA announced its intentions to make fuel tank inerting mandatory. One potential solution to this problem is to use an inert gas such as nitrogen to flood the empty fue1 tanks in order to reduce the concentration of oxygen.
Ranitidine: forgotten drug of delayed gastric emptying.
Veevers, Abbie E; Oxberry, Stephen G
2017-09-01
Delayed gastric emptying in the presence or absence of mechanical bowel obstruction can cause distressing symptoms in palliative care patients. We present two patients, both with vomiting due to delayed gastric emptying and gastric outlet obstruction secondary to pancreatic cancer, treated with subcutaneous ranitidine resulting in a symptomatic response. We hypothesise that ranitidine is a useful adjunct to standard treatment with prokinetic agents or octreotide in such patients and potentially those with proximal mechanical bowel obstruction from other malignancies with associated delayed gastric emptying. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
HIV-positive mothers with late adolescent/early adult children: "empty nest" concerns.
Murphy, Debra A; Roberts, Kathleen Johnston; Herbeck, Diane M
2012-01-01
In-depth interviews about the "empty nest" were conducted with 57 HIV-positive mothers of late adolescent/early adult children. Empty nest worries included the following: (a) identity loss, (b) loss of social support, (c) financial insecurity, (d) worsening of physical health, and (e) death/dying. Hopes included the following: (a) self-improvement, (a) change of life focus, (c) travel, (d) romantic partners, and (e) familial ties. Respondents' HIV/AIDS status colored their thoughts/feelings about the empty nest; some worries were specific to being HIV positive and would not occur for nonill mothers. Midlife HIV-positive women need health care/social service resources as they navigate health and social-psychological challenges to successful aging.
Sudheer, Surya; Alzorqi, Ibrahim; Ali, Asgar; Cheng, Poh Guat; Siddiqui, Yasmeen; Manickam, Sivakumar
2018-01-01
This study investigates the cultivation of Ganoderma lucidum using different agricultural biomasses from Malaysia. Five different combinations of rubber wood sawdust, empty fruit bunch fiber, and mesocarp fiber from oil palm, alone and in combination, were used to cultivate G. lucidum. Although all the substrate combinations worked well to grow the mushroom, the highest biological efficiency was obtained from the combination of empty fruit bunch fiber with sawdust. A total yield of 27% was obtained from empty fruit bunch fiber with sawdust, followed by sawdust (26%), empty fruit bunch fiber (19%), mesocarp fiber with sawdust (19%), and mesocarp fiber (16%). The quality of mushrooms was proved by proximate analysis and detection of phenolic compounds and flavonoids. The antioxidant activity verified by DPPH, ferric-reducing ability of plasma, and ABTS analyses revealed that the empty fruit bunch fiber with sawdust had higher activity than the other substrates.
Effect of cisapride on gastric emptying in dyspeptic patients.
Urbain, J L; Siegel, J A; Debie, N C; Pauwels, S P
1988-07-01
The effect of the new gastrokinetic agent cisapride on gastric emptying was evaluated in 17 dyspeptic patients using the dual radionuclide technique. Eight patients with idiopathic dyspepsia and nine postsurgical dyspeptic patients were studied and compared to a control group. Gastric emptying of solids and liquids was determined after ingestion of a standardized meal using 99mTc-sulfur colloid scrambled eggs as the solid phase and [111In]DTPA-labeled water as the liquid phase. Following a basal study and on a separate occasion, each patient received an intravenous bolus of 10 mg of cisapride after ingestion of the test meal; 10 of the patients were restudied after a two-week period of chronic oral administration of the drug (10 mg four times a day). Baseline gastric emptying of solids was significantly delayed in idiopathic and postsurgical patients; liquid emptying was only delayed in the postsurgical group. Intravenous and oral administration of cisapride significantly shortened gastric emptying in both groups. In all but one patient, the clinical improvement was confirmed by the test. Cisapride appears to be a good alternative to metoclopramide and domperiodone in the treatment of dyspeptic patients. The dual radionuclide technique appears to be a useful physiologic tool for evaluating and predicting the efficacy of a gastric prokinetic therapy in man.
Gastric emptying of multi-particulate dosage forms.
Newton, J Michael
2010-08-16
The evidence in the literature for the concept that multi-particulate dosage forms below a specific size empty from the stomach as if they were liquids and hence have the potential to provide the best solution to the formulation of controlled release oral dosage forms, has been considered. There is some evidence that particles less than 1.0mm provide a more rapid response than larger size particles but there is also evidence that this is not always the case and that rapid and reproducible gastric emptying of small particles does not always occur when they are administered. There is strong evidence that food can delay the gastric emptying of multi-particulate systems. Some of the misconception for gastric emptying performance of multi-particulate system is shown to be related to the limitation of the study design and limitation of the way the data is processed. Nevertheless, there is clear evidence that multi-particulate systems can provide effective oral controlled release dosage forms. There is still some way to go with experimental techniques which would allow a definitive answer to the issue of how the variability of the gastric emptying of multi-particulate systems of less than 2.0mm arises. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Imamura, Naoya; Chijiiwa, Kazuo; Ohuchida, Jiro; Hiyoshi, Masahide; Nagano, Motoaki; Otani, Kazuhiro; Kondo, Kazuhiro
2014-04-01
Although an antecolic duodenojejunostomy was reported to reduce post-operative delayed gastric emptying (DGE) compared with a retrocolic duodenojejunostomy after a pylorus-preserving pancreaticoduodenectomy (PPPD), the long-term effects of these procedures have rarely been studied. The aim of this prospective, randomized, clinical trial was to investigate the influence of the reconstruction route on post-operative gastric emptying and nutrition. Reconstruction was performed in 116 patients with an antecolic duodenojejunostomy (A group, n = 58) or a vertical retrocolic duodenojejunostomy (VR group, n = 58). Post-operative complications, including DGE, gastric emptying variables assessed by (13) C-acetate breath test and nutrition, were compared between the two groups for 1 year post-operatively. The incidence of DGE was not significantly different between the procedures (A group: 12.1%; VR group: 20.7%, P = 0.316). At post-operative month 1, gastric emptying was prolonged in the VR versus the A group but not significantly so. At post-operative month 6, gastric emptying was accelerated significantly in the A versus the VR group. Post-operative weight recovery was significantly better in the VR versus the A group at post-operative month 12 (percentage of pre-operative weight, A group: 93.8 ± 1.2%; VR group: 98.5 ± 1.3%, P = 0.015). A vertical retrocolic duodenojejunostomy was an acceptable procedure for the lower incidence of DGE and may contribute to better weight gain affected by moderate gastric emptying. © 2013 International Hepato-Pancreato-Biliary Association.
Schmitz, S; Jansen, N; Failing, K; Neiger, R
2013-01-01
The aim of the study was to assess solid phase gastric emptying via non-invasive 13C-sodium acetate breath test in large breed dogs with or without gastric dilatation-volvulus (GDV). Dogs were recruited into one of the following groups: group 1 = healthy large breed dogs with no history of GDV, group 2 = dogs that underwent elective abdominal surgery for reasons unrelated to the gastrointestinal tract, and group 3 = dogs that underwent laparotomy and gastropexy to correct GDV. The dogs were fed a test meal containing 100 mg 13C-sodium acetate (for group 2 and 3, this was < 48 hours post-operatively). Breath samples were obtained at baseline and every 30 minutes for 3 hours, then every hour for a total of 7 hours. 12CO2/13CO2 ratio was measured for each breath sample via non-dispersive infrared spectroscopy and 25%, 50% and 75% gastric emptying times were calculated and compared between groups. Gastric emptying times were significantly prolonged in dogs undergoing surgery (group 2) compared to group 1 and 3. Also, gastric emptying times of dogs with GDV were significantly prolonged compared to controls, but not to the same extent as dogs in group 2. There was a significant effect of abdominal surgery on gastric emptying times. Surprisingly, dogs after GDV surgery and gastropexy had shorter gastric emptying times than dogs undergoing laparotomy for reasons other than GDV, but still prolonged compared to healthy controls. The reason for these differences requires further study.
Guo, Qing; Ye, Aiqian; Lad, Mita; Ferrua, Maria; Dalgleish, Douglas; Singh, Harjinder
2015-03-01
The understanding of the disintegration and gastric emptying of foods in the stomach is important for designing functional foods. In this study, a dynamic stomach model (human gastric simulator, HGS) was employed to investigate the disintegration and subsequent emptying of two differently structured whey protein emulsion gels (soft and hard gels).The gels were mechanically ground into fragments to reproduce the particle size distribution of an in vivo gel bolus. The simulated gel bolus was prepared by mixing gel fragments and artificial saliva, and exposed to 5 hours of simulated gastric digestion in the presence and absence of pepsin. Results showed that regardless of pepsin, the soft gel always disintegrated faster than the hard gel. The presence of pepsin significantly accelerated the disintegration of both gels. In particular, it enhanced abrasion of the soft gel into fine particles (<0.425 mm) after 180 min of processing. The emptying of the gels was influenced by the combined effects of the original particle size of the gel boluses and their disintegration kinetics in the HGS. In the presence or absence of pepsin, the larger particles of the soft gel emptied slower than the hard one during the first 120 min of process. However, in the presence of pepsin, the soft gel emptied faster than the hard one after 120 min because of a higher level of disintegration. These findings highlight the role of food structure, bolus properties and biochemical effects on the disintegration and gastric emptying patterns of gels during gastric digestion.
Ullrich, Sina S; Fitzgerald, Penelope C E; Giesbertz, Pieter; Steinert, Robert E; Horowitz, Michael; Feinle-Bisset, Christine
2018-04-08
Tryptophan stimulates plasma cholecystokinin and pyloric pressures, both of which slow gastric emptying. Gastric emptying regulates postprandial blood glucose. Tryptophan has been reported to decrease energy intake. We investigated the effects of intragastric tryptophan on the glycaemic response to, and gastric emptying of, a mixed-nutrient drink, and subsequent energy intake. Lean and obese participants ( n = 16 each) received intragastric infusions of 1.5 g ("Trp-1.5g") or 3.0 g ("Trp-3.0g") tryptophan, or control, and 15 min later consumed a mixed-nutrient drink (56 g carbohydrates). Gastric emptying ( 13 C-acetate breath-test), blood glucose, plasma C-peptide, glucagon, cholecystokinin and tryptophan concentrations were measured ( t = 0-60 min). Energy intake was assessed between t = 60-90 min. In lean individuals, Trp-3.0g, but not Trp-1.5g, slowed gastric emptying, reduced C-peptide AUC and increased glucagon AUC (all P < 0.05), but did not significantly decrease the blood glucose response to the drink, stimulate cholecystokinin or reduce mean energy intake, compared with control. In obese individuals, Trp-3.0g, but not Trp-1.5g, tended to slow gastric emptying ( P = 0.091), did not affect C-peptide AUC , increased glucagon AUC ( P < 0.001) and lowered blood glucose at t = 30 min ( P < 0.05), and did not affect cholecystokinin or mean energy intake. In obese individuals, intragastrically administered tryptophan may reduce postprandial blood glucose by slowing gastric emptying; the lack of effect on mean energy intake requires further investigation.
Fournier, Alice; Rollin, Orianne; Le Féon, Violette; Decourtye, Axel; Henry, Mickaël
2014-02-01
Recent scientific literature and reports from official sanitary agencies have pointed out the deficiency of current pesticide risk assessment processes regarding sublethal effects on pollinators. Sublethal effects include troubles in learning performance, orientation skills, or mobility, with possible contribution to substantial dysfunction at population scale. However, the study of sublethal effects is currently limited by considerable knowledge gaps, particularly for the numerous pollinators other than the honey bee Apis mellifera L.--the traditional model for pesticide risk assessment in pollinators. Here, we propose to use the crop-emptying time as a rule of thumb to guide the design of oral exposure experiments in the honey bee and wild bees. The administration of contaminated sucrose solutions is typically followed by a fasting time lapse to allow complete assimilation before the behavioral tests. The fasting duration should at least encompass the crop-emptying time, because no absorption takes place in the crop. We assessed crop-emptying rate in fasted bees and how it relates 1) with sucrose solution concentration in the honey bee and 2) with body mass in wild bees. Fasting duration required for complete crop emptying in honey bees fed 20 microl of a 50% sucrose solution was nearly 2 h. Actual fasting durations are usually shorter in toxicological studies, suggesting incomplete crop emptying, and therefore partial assimilation of experimental solutions that could imply underestimation of sublethal effects. We also found faster crop-emptying rates in large wild bees compared with smaller wild bees, and suggest operative rules to adapt sublethal assessment schemes accordingly.
Iwata, Eiichiro; Shigematsu, Hideki; Inoue, Kazuya; Egawa, Takuya; Sakamoto, Yoshihiro; Tanaka, Yasuhito
2017-01-01
Rotator cuff tears and cervical spondylotic amyotrophy (CSA) are often confused as the main symptom in those with difficulty in shoulder elevation. Empty and full can tests are frequently used for the clinical diagnosis of rotator cuff tears. The aim of the present study was to investigate whether the empty and full can test results can help differentiate rotator cuff tears from CSA. Twenty-seven consecutive patients with rotator cuff tears and 25 with CSA were enrolled. We prospectively performed empty and full can tests in patients with rotator cuff tears and CSA. The following signs were considered positive: (a) muscle weakness during the empty can test, (b) muscle weakness during the full can test, (c) pain provocation during the empty can test, and (d) pain provocation during the full can test. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of rotator cuff tears for each positive finding. The sensitivity and specificity of each index were as follows (sensitivity, specificity, PPV, NPV): (a) 77.8%, 0%, 45.7%, 0%; (b) 66.7%, 4.0%, 42.9%, 10.0%; (c) 88.9%, 96.0%, 96.0%, 88.9%; and (d) 74.1%, 96.0%, 95.2%, 77.4%. There were significant differences for each index. Muscle weakness during the empty and full can tests was not useful in differentiating rotator cuff tears from CSA because of low specificity and PPV. However, pain provocation was useful in differentiating these two conditions because of high specificity and PPV.
Okamura, Takayuki; Yamamoto, Takatsugu; Kimura, Satoshi; Miki, Atsushi; Abe, Koichiro; Kita, Hiroto
2017-11-01
Lubiprostone is effective for patients with chronic constipation. This agent sometimes causes upper gastrointestinal symptoms, such as nausea, which is one of the chief reasons for discontinuation. However, the etiology of and strategy against bothersome gastrointestinal symptoms of lubiprostone remain unclear. The goal of this study was to investigate the influence of lubiprostone on the gastric-emptying profile of healthy adults. The effect of domperidone on gastric emptying and gastrointestinal symptoms after lubiprostone administration were also assessed. 80 healthy male participants underwent 13C acetate breath testing to evaluate gastric emptying. The test meal comprised 200 kcal of a standard liquid nutrient. Each participant underwent 3 random breath tests with: 1) no premedication; 2) 24 µg of lubiprostone 30 minutes prior to the study; and 3) 24 µg of lubiprostone plus 10 mg of domperidone 30 minutes prior to the study. Gastrointestinal symptoms (heartburn, regurgitation, epigastric pain, fullness, distress feeling) during testing were evaluated using a 7-point scoring system. Gastric emptying was significantly delayed by the administration of lubiprostone. Among all 8 subjects, 4 reported heartburn after taking lubiprostone, whereas this symptom was not found when subjects received concomitant domperidone. However, gastric emptying showed little change between lubiprostone alone and lubiprostone plus domperidone. Lubiprostone delayed gastric emptying of liquid in healthy adults, which could be associated with the gastrointestinal symptoms caused by the agent. Domperidone seemed effective against such gastrointestinal symptoms after administration of lubiprostone. This effect seemed unrelated to gastric motility. .
Gongronema latifolium delays gastric emptying of semi-solid meals in diabetic dogs.
Ogbu, Sylvester Osita; Agwu, Kenneth Kalu; Asuzu, Isaac Uzoma
2013-01-01
The aim of the study was to investigate sonographically the effect of Gongronema latifolium on gastric emptying of semi-solid meals in diabetic dogs. Twenty-five alloxan-induced diabetic dogs were randomly allotted into five groups of five dogs each in a randomised placebo-controlled study. These are placebo, prokinetic dose, low dose, moderate dose and high dose groups. The placebo group served as the control. The low, moderate and high dose groups ingested methanolic leaf extract of G. latifolium at 100 mg/kg, 250 mg/kg, 500 mg/kg respectively, while the prokinetic group ingested 0.5 mg/kg of metoclopramide. After a 12-hour fast, each group ingested its treatment capsules 30 minutes before the administration of test meal. Measurements of gastric emptying and blood glucose levels were obtained from each dog 30 minutes before and immediately after the ingestion of a test meal, every 15 minutes for another 4 hours and then every 30 minutes for further 2 hours. Gastric emptying of the moderate and high dose groups were 227.8 ± 9.9 min and 261.3 ± 19.3 min respectively and significantly (p < 0.0001) slower than the placebo control group of 143.0 ± 17.8 min. The gastric emptying of the low dose group (169.8 ± 3.8) and control group did not differ significantly (p > 0.05). A strong inverse relationship between gastric emptying and the incremental blood glucose levels was noted in the diabetic dogs after the ingestion of Gongronema latifolium (r = -0.90; p < 0.0001). Gonogronema latifolium delayed gastric emptying in diabetic dogs.
Holzäpfel, A; Festa, A; Stacher-Janotta, G; Bergmann, H; Shnawa, N; Brannath, W; Schernthaner, G; Stacher, G
1999-12-01
Hyperglycaemia that is induced short-term slows gastric emptying in healthy subjects and patients with diabetes mellitus. Little information is available on the impact of longer-lasting, naturally occurring blood glucose increases and their reduction to euglycaemic values. We studied the relation between gastric emptying and pre-prandial and postprandial blood glucose concentrations in patients with Type II (non-insulin-dependent) diabetes mellitus and secondary failure to respond to oral hypoglycaemic treatment (a) before readjusting hypoglycaemic therapy and (b) 1 week thereafter. We studied 9 female and 1 male patient (age 60-78 years, BMI 21.9-32.5 kg/m2, diabetes duration 3-33 years, HbA1c 8.8-13.2%). Gastric emptying of a radiolabelled semisolid 1168 kJ meal was recorded scintigraphically. Blood glucose concentration pre-prandial and postprandial was considerably lower subsequent to than before therapy readjustment in all patients (fasting, 7.9 mmol/l+/-1.5 SD vs 11.7+/-1.7 mmol/l; 60 min postprandial, 11.7+/-2.0 vs 15.4+/-2.2 mmol/l). By contrast, gastric emptying was unchanged (residual radioactivity in stomach 50 min postprandial 65.7+/-14.1% vs 66.5+/-12.9%). There was no relation between emptying and either fasting blood glucose concentration or its postprandial increase. The data do not support a major impact of actual, longer-lasting, naturally occurring blood glucose concentrations upon the rate of gastric emptying in patients with Type II diabetes.
Lack of modulation of gastric emptying by dietary nitrate in healthy volunteers.
Terai, Shiho; Iijima, Katsunori; Asanuma, Kiyotaka; Ara, Nobuyuki; Uno, Kaname; Abe, Yasuhiko; Koike, Tomoyuki; Imatani, Akira; Ohara, Shuichi; Shimosegawa, Tooru
2009-05-01
Nitric oxide produced endogenously in vagal neurons modulates gastrointestinal motor activity as an important non-adrenergic and non-cholinergic neurotransmitter. Other than through endogenous biosynthesis, a high concentration of nitric oxide also occurs by chemical reactions within the stomach in the presence of gastric acid through the entero-salivary re-circulation of dietary nitrate. Although dietary nitrate can be a potential source of nitric oxide in the human stomach, there has been no report on the effect of dietary nitrate on gastric motor function. The aim of this study is to investigate the effect of dietary nitrate on gastric emptying, one of the major parameters for the gastric motor function. Fifteen healthy volunteers underwent a placebo-controlled (310 mg sodium nitrate or placebo), double-blind, crossover trial. Since a sufficient amount of gastric acid is essential for dietary nitrate-derived nitric oxide generation in the stomach, the same protocol was repeated after 1-week treatment with a proton pump inhibitor, rabeprazole. Gastric emptying was evaluated by (13)C-octanoate breath test. The sodium nitrate ingestion did not affect gastric emptying either prior to or during rabeprazole treatment, although rabeprazole treatment itself significantly delayed gastric emptying, being independent of the dietary nitrate load. Confirmation of the delayed gastric emptying with rabeprazole indicates the sensitivity of the breath test employed in the present study. In conclusion, despite the potential nitrogen source of exogenous nitric oxide, the ingestion of 310 mg sodium nitrate, which is equivalent to the average daily intake of Japanese adults, does not affect gastric emptying in healthy volunteers.
Imamura, Naoya; Chijiiwa, Kazuo; Ohuchida, Jiro; Hiyoshi, Masahide; Nagano, Motoaki; Otani, Kazuhiro; Kondo, Kazuhiro
2014-01-01
Background Although an antecolic duodenojejunostomy was reported to reduce post-operative delayed gastric emptying (DGE) compared with a retrocolic duodenojejunostomy after a pylorus-preserving pancreaticoduodenectomy (PPPD), the long-term effects of these procedures have rarely been studied. The aim of this prospective, randomized, clinical trial was to investigate the influence of the reconstruction route on post-operative gastric emptying and nutrition. Methods Reconstruction was performed in 116 patients with an antecolic duodenojejunostomy (A group, n = 58) or a vertical retrocolic duodenojejunostomy (VR group, n = 58). Post-operative complications, including DGE, gastric emptying variables assessed by 13C-acetate breath test and nutrition, were compared between the two groups for 1 year post-operatively. Results The incidence of DGE was not significantly different between the procedures (A group: 12.1%; VR group: 20.7%, P = 0.316). At post-operative month 1, gastric emptying was prolonged in the VR versus the A group but not significantly so. At post-operative month 6, gastric emptying was accelerated significantly in the A versus the VR group. Post-operative weight recovery was significantly better in the VR versus the A group at post-operative month 12 (percentage of pre-operative weight, A group: 93.8 ± 1.2%; VR group: 98.5 ± 1.3%, P = 0.015). Conclusions A vertical retrocolic duodenojejunostomy was an acceptable procedure for the lower incidence of DGE and may contribute to better weight gain affected by moderate gastric emptying. PMID:23991719
Kasicka-Jonderko, A; Jonderko, K; Gajek, E; Piekielniak, A; Zawislan, R
2014-02-01
To study the movement along the gut and the effect upon the gallbladder volume of alcoholic beverages taken in the interdigestive state. The study comprised three research blocks attended by 12 healthy subjects each. Within a given research block volunteers underwent three examination sessions held on separate days, being offered an alcoholic beverage, or an aqueous ethanol solution of an identical proof, or a corresponding volume of isotonic glucose solution; the order of administration of the drinks was randomized. The beverages tested were: beer (4.7% vol, 400 ml), red wine (13.7% vol, 200 ml), whisky (43.5% vol, 100 ml) within the "Beer", "Wine", and "Whisky" research block, respectively. Gastric myoelectrical activity was examined electrogastrographically, gastric emptying with ¹³C-sodium acetate breath test, orocaecal transit with lactulose H₂ breath test, gallbladder emptying with ultrasonography, breath ethanol with alcotest. The study showed that alcoholic beverages were emptied from the stomach significantly slower than isotonic glucose. Alcoholic beverages produced by fermentation only (beer, red wine) were emptied from the stomach more slowly than ethanol solutions of identical proof, while gastric evacuation of whisky (distillation product) and matching alcohol solution was similar. The slower gastric evacuation of alcoholic beverages and ethanol solutions could not be ascribed to a disorganization of the gastric myoelectrical activity. The orocaecal transit of beer and red wine did not differ from that of isotonic glucose, whereas the orocaecal transit of whisky and high proof ethanol was markedly prolonged. Red wine and whisky, and to a similar extent control ethanol solutions caused an inhibition and delay of gallbladder emptying. We concluded that alcoholic beverages taken on an empty stomach exert a suppressive effect upon the transport function of the digestive tract and gallbladder emptying. The extent of this action depends on the type of a beverage (whether it is obtained from fermentation only, or fermentation followed by distillation) and ethanol concentration therein.
Empty nano and micro-structured lipid carriers of virgin coconut oil for skin moisturisation.
Noor, Norhayati Mohamed; Khan, Abid Ali; Hasham, Rosnani; Talib, Ayesha; Sarmidi, Mohamad Roji; Aziz, Ramlan; Aziz, Azila Abd
2016-08-01
Virgin coconut oil (VCO) is the finest grade of coconut oil, rich in phenolic content, antioxidant activity and contains medium chain triglycerides (MCTs). In this work formulation, characterisation and penetration of VCO-solid lipid particles (VCO-SLP) have been studied. VCO-SLP were prepared using ultrasonication of molten stearic acid and VCO in an aqueous solution. The electron microscopy imaging revealed that VCO-SLP were solid and spherical in shape. Ultrasonication was performed at several power intensities which resulted in particle sizes of VCO-SLP ranged from 0.608 ± 0.002 µm to 44.265 ± 1.870 µm. The particle size was directly proportional to the applied power intensity of ultrasonication. The zeta potential values of the particles were from -43.2 ± 0.28 mV to -47.5 ± 0.42 mV showing good stability. The cumulative permeation for the smallest sized VCO-SLP (0.608 µm) was 3.83 ± 0.01 µg/cm(2) whereas for larger carriers it was reduced (3.59 ± 0.02 µg/cm(2)). It is concluded that SLP have the potential to be exploited as a micro/nano scale cosmeceutical carrying vehicle for improved dermal delivery of VCO.
miktoarm polymer: controlled synthesis, characterization, and application as anticancer drug carrier
NASA Astrophysics Data System (ADS)
Lin, Wenjing; Nie, Shuyu; Xiong, Di; Guo, Xindong; Wang, Jufang; Zhang, Lijuan
2014-05-01
Amphiphilic A2(BC)2 miktoarm star polymers [poly(ɛ-caprolactone)]2-[poly(2-(diethylamino)ethyl methacrylate)- b- poly(poly(ethylene glycol) methyl ether methacrylate)]2 [(PCL)2(PDEA- b-PPEGMA)2] were developed by a combination of ring opening polymerization (ROP) and continuous activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The critical micelle concentration (CMC) values were extremely low (0.0024 to 0.0043 mg/mL), depending on the architecture of the polymers. The self-assembled empty and doxorubicin (DOX)-loaded micelles were spherical in morphologies, and the average sizes were about 63 and 110 nm. The release of DOX at pH 5.0 was much faster than that at pH 6.5 and pH 7.4. Moreover, DOX-loaded micelles could effectively inhibit the growth of cancer cells HepG2 with IC50 of 2.0 μg/mL. Intracellular uptake demonstrated that DOX was delivered into the cells effectively after the cells were incubated with DOX-loaded micelles. Therefore, the pH-sensitive (PCL)2(PDEA- b-PPEGMA)2 micelles could be a prospective candidate as anticancer drug carrier for hydrophobic drugs with sustained release behavior.
Chen, Fei; Xu, Xiang-Long; Yang, Zhan; Tan, Hua-Wei; Zhang, Liang
2015-08-10
In 2012, a pilot health policy of contractual service relations between general practitioners and patients was implemented in China. Due to the decline in body and cognitive function, as well as the lack of family care and narrow social support networks, the demand of health services among the elderly is much higher than that among the general population. This study aims to probe into the empty nesters' willingness-to-pay for general practitioners using a contractual service policy, investigating empty nesters' payment levels for the service, and analyze the main factors affecting the willingness of empty-nesters' general practitioners using contractual service supply cost. This cross-sectional study adopted a multistage stratified sampling method to survey 865, city empty nesters (six communities in three districts of one city) aged 60-85 years. A condition value method was used to infer the distribution of the willingness-to-pay; Cox's proportional hazards regression model was used to analyze the influencing factors of willingness-to-pay. More than seventy percent (76.6%) of the empty nesters in this city were willing to pay general practitioners using contract service in Chongqing. The level of willingness-to-pay for the surveyed empty nesters was 34.1 yuan per year. The median value was 22.1 yuan per year, which was below the Chongqing urban and rural cooperative medical insurance individual funding level (60 yuan per year) in 2013. Cox's proportional hazards regression model analysis showed that the higher the education level was, the worse the self-reported health status would be, accompanied by higher family per capita income, higher satisfaction of community health service, and higher willingness-to-pay empty nesters using a contract service. Women had a higher willingness-to-pay than men. The willingness-to-pay for general practitioners by contractual service is high among city empty nesters in Chongqing, thus, individual financing is feasible. However, people are willing to pay less than half of the current personal financing of cooperative medical insurance of urban and rural residents. Education level, family per capita income, and self-reported health status are the main factors affecting the cost sharing intention for general practitioners using contract service supply. According to the existing situation of different empty nesters, it is important to perfect the design of general practitioners using a contractual service policy system, according to differentiated personal financing levels.
Chen, Fei; Xu, Xiang-Long; Yang, Zhan; Tan, Hua-Wei; Zhang, Liang
2015-01-01
Background: In 2012, a pilot health policy of contractual service relations between general practitioners and patients was implemented in China. Due to the decline in body and cognitive function, as well as the lack of family care and narrow social support networks, the demand of health services among the elderly is much higher than that among the general population. This study aims to probe into the empty nesters’ willingness-to-pay for general practitioners using a contractual service policy, investigating empty nesters’ payment levels for the service, and analyze the main factors affecting the willingness of empty-nesters’ general practitioners using contractual service supply cost. Methods: This cross-sectional study adopted a multistage stratified sampling method to survey 865, city empty nesters (six communities in three districts of one city) aged 60–85 years. A condition value method was used to infer the distribution of the willingness-to-pay; Cox’s proportional hazards regression model was used to analyze the influencing factors of willingness-to-pay. Results: More than seventy percent (76.6%) of the empty nesters in this city were willing to pay general practitioners using contract service in Chongqing. The level of willingness-to-pay for the surveyed empty nesters was 34.1 yuan per year. The median value was 22.1 yuan per year, which was below the Chongqing urban and rural cooperative medical insurance individual funding level (60 yuan per year) in 2013. Cox’s proportional hazards regression model analysis showed that the higher the education level was, the worse the self-reported health status would be, accompanied by higher family per capita income, higher satisfaction of community health service, and higher willingness-to-pay empty nesters using a contract service. Women had a higher willingness-to-pay than men. Conclusions: The willingness-to-pay for general practitioners by contractual service is high among city empty nesters in Chongqing, thus, individual financing is feasible. However, people are willing to pay less than half of the current personal financing of cooperative medical insurance of urban and rural residents. Education level, family per capita income, and self-reported health status are the main factors affecting the cost sharing intention for general practitioners using contract service supply. According to the existing situation of different empty nesters, it is important to perfect the design of general practitioners using a contractual service policy system, according to differentiated personal financing levels. PMID:26266416
2017-01-01
Adenovirus (AdV) morphogenesis is a complex process, many aspects of which remain unclear. In particular, it is not settled where in the nucleus assembly and packaging occur, and whether these processes occur in a sequential or a concerted manner. Here we use immunofluorescence and immunoelectron microscopy (immunoEM) to trace packaging factors and structural proteins at late times post infection by either wildtype virus or a delayed packaging mutant. We show that representatives of all assembly factors are present in the previously recognized peripheral replicative zone, which therefore is the AdV assembly factory. Assembly intermediates and abortive products observed in this region favor a concurrent assembly and packaging model comprising two pathways, one for capsid proteins and another one for core components. Only when both pathways are coupled by correct interaction between packaging proteins and the genome is the viral particle produced. Decoupling generates accumulation of empty capsids and unpackaged cores. PMID:28448571
El Omari, Kamel; Sutton, Geoff; Ravantti, Janne J; Zhang, Hanwen; Walter, Thomas S; Grimes, Jonathan M; Bamford, Dennis H; Stuart, David I; Mancini, Erika J
2013-08-06
The hallmark of a virus is its capsid, which harbors the viral genome and is formed from protein subunits, which assemble following precise geometric rules. dsRNA viruses use an unusual protein multiplicity (120 copies) to form their closed capsids. We have determined the atomic structure of the capsid protein (P1) from the dsRNA cystovirus Φ8. In the crystal P1 forms pentamers, very similar in shape to facets of empty procapsids, suggesting an unexpected assembly pathway that proceeds via a pentameric intermediate. Unlike the elongated proteins used by dsRNA mammalian reoviruses, P1 has a compact trapezoid-like shape and a distinct arrangement in the shell, with two near-identical conformers in nonequivalent structural environments. Nevertheless, structural similarity with the analogous protein from the mammalian viruses suggests a common ancestor. The unusual shape of the molecule may facilitate dramatic capsid expansion during phage maturation, allowing P1 to switch interaction interfaces to provide capsid plasticity. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.
Ren, Jingshan; Wang, Xiangxi; Zhu, Ling; Hu, Zhongyu; Gao, Qiang; Yang, Pan; Li, Xuemei; Wang, Junzhi; Shen, Xinliang; Fry, Elizabeth E; Rao, Zihe; Stuart, David I
2015-10-01
Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the primary causes of the epidemics of hand-foot-and-mouth disease (HFMD) that affect more than a million children in China each year and lead to hundreds of deaths. Although there has been progress with vaccines for EV71, the development of a CVA16 vaccine has proved more challenging, and the EV71 vaccine does not give useful cross-protection, despite the capsid proteins of the two viruses sharing about 80% sequence identity. The structural details of the expanded forms of the capsids, which possess nonnative antigenicity, are now well understood, but high resolution information for the native antigenic form of CVA16 has been missing. Here, we remedy this with high resolution X-ray structures of both mature and natural empty CVA16 particles and also of empty recombinant viruslike particles of CVA16 produced in insect cells, a potential vaccine antigen. All three structures are unexpanded native particles and antigenically identical. The recombinant particles have recruited a lipid moiety to stabilize the native antigenic state that is different from the one used in a natural virus infection. As expected, the mature CVA16 virus is similar to EV71; however, structural and immunogenic comparisons highlight differences that may have implications for vaccine production. Hand-foot-and-mouth disease is a serious public health threat to children in Asian-Pacific countries, resulting in millions of cases. EV71 and CVA16 are the two dominant causative agents of the disease that, while usually mild, can cause severe neurological complications, leading to hundreds of deaths. EV71 vaccines do not provide protection against CVA16. A CVA16 vaccine or bivalent EV71/CVA16 vaccine is therefore urgently needed. We report atomic structures for the mature CVA16 virus, a natural empty particle, and a recombinant CVA16 virus-like particle that does not contain the viral genome. All three particles have similar structures and identical antigenicity. The recombinant particles, produced in insect cells (a system suitable for making vaccine antigen), are stabilized by recruiting from the insect cells a small molecule that is different from that used by the virus in a normal infection. We present structural and immunogenic comparisons with EV71 to facilitate structure-based drug design and vaccine development. Copyright © 2015, Ren et al.
Regulation the morphology of cationized gold nanoparticles for effective gene delivery.
Zhang, Peng; Li, Bangbang; Du, Jianwei; Wang, Youxiang
2017-09-01
Recent research indicated that the morphology of nanoparticles could result in distinct biological behaviors, thus played an important role in designing efficient gene delivery systems. Among them, gold nanoparticles (AuNPs) with various shapes were widely studied due to the good biocompatibility and easy modification ability. Our recent research indicated that polyethyleneimine-g-bovine serum albumin (BSA-PEI) as non-viral gene vector showed good colloid stability and high transfection efficiency. In this work, BSA-PEI was utilized to modify gold nanospheres (AuNSs) and gold nanorods (AuNRs) to investigate the influence of the morphology on gene delivery. Both AuNS@BSA-PEI and AuNR@BSA-PEI nanoparticles condensed DNA effectively at N/P ratio above 5 and maintained spherical or rod-like morphology respectively. Due to the higher surface charge density at the tips, the rod-like gene complexes were prone to use the tips to contact with cell membrane, which facilitated to be uptaked by HepG2 cells. The endocytosis inhibition experiments showed some differences in the endocytic pathway. Gene transfection experiment showed that the rod-like complexes had almost 100-fold higher of transfection level than that of spherical complexes at the N/P ratio of 20. This work provided a potential strategy for further design of gene vectors with improved transfection results by adjusting the morphology of gene vectors. Copyright © 2017. Published by Elsevier B.V.
The Rhinovirus Subviral A-Particle Exposes 3′-Terminal Sequences of Its Genomic RNA
Harutyunyan, Shushan; Kowalski, Heinrich
2014-01-01
ABSTRACT Enteroviruses, which represent a large genus within the family Picornaviridae, undergo important conformational modifications during infection of the host cell. Once internalized by receptor-mediated endocytosis, receptor binding and/or the acidic endosomal environment triggers the native virion to expand and convert into the subviral (altered) A-particle. The A-particle is lacking the internal capsid protein VP4 and exposes N-terminal amphipathic sequences of VP1, allowing for its direct interaction with a lipid bilayer. The genomic single-stranded (+)RNA then exits through a hole close to a 2-fold axis of icosahedral symmetry and passes through a pore in the endosomal membrane into the cytosol, leaving behind the empty shell. We demonstrate that in vitro acidification of a prototype of the minor receptor group of common cold viruses, human rhinovirus A2 (HRV-A2), also results in egress of the poly(A) tail of the RNA from the A-particle, along with adjacent nucleotides totaling ∼700 bases. However, even after hours of incubation at pH 5.2, 5′-proximal sequences remain inside the capsid. In contrast, the entire RNA genome is released within minutes of exposure to the acidic endosomal environment in vivo. This finding suggests that the exposed 3′-poly(A) tail facilitates the positioning of the RNA exit site onto the putative channel in the lipid bilayer, thereby preventing the egress of viral RNA into the endosomal lumen, where it may be degraded. IMPORTANCE For host cell infection, a virus transfers its genome from within the protective capsid into the cytosol; this requires modifications of the viral shell. In common cold viruses, exit of the RNA genome is prepared by the acidic environment in endosomes converting the native virion into the subviral A-particle. We demonstrate that acidification in vitro results in RNA exit starting from the 3′-terminal poly(A). However, the process halts as soon as about 700 bases have left the viral shell. Conversely, inside the cell, RNA egress completes in about 2 min. This suggests the existence of cellular uncoating facilitators. PMID:24672023
Kwiatek, Monika A; Menne, Dieter; Steingoetter, Andreas; Goetze, Oliver; Forras-Kaufman, Zsofia; Kaufman, Elad; Fruehauf, Heiko; Boesiger, Peter; Fried, Michael; Schwizer, Werner; Fox, Mark R
2009-11-01
This study assessed the effects of meal volume (MV) and calorie load (CL) on gastric function. MRI and a minimally invasive fiber-optic recording system (FORS) provided simultaneous measurement of gastric volume and pressure changes during gastric filling and emptying of a liquid nutrient meal in physiological conditions. The gastric response to 12 iso-osmolar MV-CL combinations of a multinutrient drink (MV: 200, 400, 600, 800 ml; CL: 200, 300, 400 kcal) was tested in 16 healthy subjects according to a factorial design. Total gastric volume (TGV) and gastric content volume (GCV = MV + secretion) were measured by MRI during nasogastric meal infusion and gastric emptying over 60 min. Intragastric pressure was assessed at 1 Hz by FORS. The dynamic change in postprandial gastric volumes was described by a validated three-component linear exponential model. The stomach expanded with MV, but the ratio of GCV:MV at t(0) diminished with increasing MV (P < 0.01). Postprandial changes in TGV followed those of GCV. Intragastric pressure increased with MV, and this effect was augmented further by CL (P = 0.02); however, the absolute pressure rise was <4 mmHg. A further postprandial increase of gastric volumes was observed early on before any subsequent volume decrease. This "early" increase in GCV was greater for smaller than larger MV (P < 0.01), indicating faster initial gastric emptying of larger MV. In contrast, volume change during filling and in the early postprandial period were unaffected by CL. In the later postprandial period, gastric emptying rate continued to be more rapid with high MVs (P < 0.001); however, at any given volume, gastric emptying was slowed by higher CL (P < 0.001). GCV half-emptying time decreased with CL at 18 +/- 6 min for each additional 100-kcal load (P < 0.001). These findings indicate that gastric wall stress (passive strain and active tone) provides the driving force for gastric emptying, but distal resistance to gastric outflow regulates further passage of nutrients. The distinct early phase of gastric emptying with relatively rapid, uncontrolled passage of nutrients into the small bowel, modulated by meal volume but not nutrient composition, ensures that the delivery of nutrients in the later postprandial period is related to the overall calorie load of the meal.
Estimation of body composition of pigs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ferrell, C.L.; Cornelius, S.G.
A study was conducted to evaluate the use of deuterium oxide (D2O) for in vivo estimation of body composition of diverse types of pigs. Obese (Ob, 30) and contemporary Hampshire X Yorkshire (C, 30) types of pigs used in the study were managed and fed under typical management regimens. Indwelling catheters were placed in a jugular vein of 6 Ob and 6 C pigs at 4, 8, 12, 18 and 24 wk of age. The D2O was infused (.5 g/kg body weight) as a .9% NaCl solution into the jugular catheter. Blood samples were taken immediately before and at .25,more » 1, 4, 8, 12, 24 and 48 h after the D2O infusion and D2O concentration in blood water was determined. Pigs were subsequently killed by euthanasia injection. Contents of the gastrointestinal tract were removed and the empty body was then frozen and later ground and sampled for subsequent analyses. Ground body tissue samples were analyzed for water, fat, N, fat-free organic matter and ash. Pig type, age and the type X age interaction were significant sources of variation in live weight, D2O pool size and all empty body components, as well as all fat-free empty body components. Relationships between age and live weight or weight of empty body components, and between live weight, empty body weight, empty body water or D2O space and weight of empty components were highly significant but influenced, in most cases, by pig type. The results of this study suggested that, although relationships between D2O space and body component weights were highly significant, they were influenced by pig type and were little better than live weight for the estimation of body composition.« less
Ullrich, Sina S.; Fitzgerald, Penelope C. E.; Giesbertz, Pieter; Steinert, Robert E.; Horowitz, Michael; Feinle-Bisset, Christine
2018-01-01
Tryptophan stimulates plasma cholecystokinin and pyloric pressures, both of which slow gastric emptying. Gastric emptying regulates postprandial blood glucose. Tryptophan has been reported to decrease energy intake. We investigated the effects of intragastric tryptophan on the glycaemic response to, and gastric emptying of, a mixed-nutrient drink, and subsequent energy intake. Lean and obese participants (n = 16 each) received intragastric infusions of 1.5 g (“Trp-1.5g”) or 3.0 g (“Trp-3.0g”) tryptophan, or control, and 15 min later consumed a mixed-nutrient drink (56 g carbohydrates). Gastric emptying (13C-acetate breath-test), blood glucose, plasma C-peptide, glucagon, cholecystokinin and tryptophan concentrations were measured (t = 0–60 min). Energy intake was assessed between t = 60–90 min. In lean individuals, Trp-3.0g, but not Trp-1.5g, slowed gastric emptying, reduced C-peptideAUC and increased glucagonAUC (all P < 0.05), but did not significantly decrease the blood glucose response to the drink, stimulate cholecystokinin or reduce mean energy intake, compared with control. In obese individuals, Trp-3.0g, but not Trp-1.5g, tended to slow gastric emptying (P = 0.091), did not affect C-peptideAUC, increased glucagonAUC (P < 0.001) and lowered blood glucose at t = 30 min (P < 0.05), and did not affect cholecystokinin or mean energy intake. In obese individuals, intragastrically administered tryptophan may reduce postprandial blood glucose by slowing gastric emptying; the lack of effect on mean energy intake requires further investigation. PMID:29642492
Scale-space for empty catheter segmentation in PCI fluoroscopic images.
Bacchuwar, Ketan; Cousty, Jean; Vaillant, Régis; Najman, Laurent
2017-07-01
In this article, we present a method for empty guiding catheter segmentation in fluoroscopic X-ray images. The guiding catheter, being a commonly visible landmark, its segmentation is an important and a difficult brick for Percutaneous Coronary Intervention (PCI) procedure modeling. In number of clinical situations, the catheter is empty and appears as a low contrasted structure with two parallel and partially disconnected edges. To segment it, we work on the level-set scale-space of image, the min tree, to extract curve blobs. We then propose a novel structural scale-space, a hierarchy built on these curve blobs. The deep connected component, i.e. the cluster of curve blobs on this hierarchy, that maximizes the likelihood to be an empty catheter is retained as final segmentation. We evaluate the performance of the algorithm on a database of 1250 fluoroscopic images from 6 patients. As a result, we obtain very good qualitative and quantitative segmentation performance, with mean precision and recall of 80.48 and 63.04% respectively. We develop a novel structural scale-space to segment a structured object, the empty catheter, in challenging situations where the information content is very sparse in the images. Fully-automatic empty catheter segmentation in X-ray fluoroscopic images is an important and preliminary step in PCI procedure modeling, as it aids in tagging the arrival and removal location of other interventional tools.
Double-stranded RNA virus in the human pathogenic fungus Blastomyces dermatitidis.
Kohno, S; Fujimura, T; Rulong, S; Kwon-Chung, K J
1994-01-01
Double-stranded RNA viruses were detected in a strain of Blastomyces dermatitidis isolated from a patient in Uganda. The viral particles are spherical (mostly 44 to 50 nm in diameter) and consist of about 25% double-stranded RNA (5 kb) and 75% protein (90 kDa). The virus contains transcriptional RNA polymerase activity; it synthesized single-stranded RNA in vitro in a conservative manner. The newly synthesized single-stranded RNA was a full-length strand, and the rate of chain elongation was approximately 170 nucleotides per min. The virus-containing strain shows no morphological difference from virus-free strains in the mycelial phase. Although the association with the presence of the virus is unclear, the virus-infected strain converts to the yeast form at 37 degrees C, but the yeast cells fail to multiply at that temperature. Images PMID:7933142
Starkey, Jason; Mellinger, Erica; Zhang, Dan; Chadha, Pooja; Carmichael, Jillian
2017-01-01
ABSTRACT The initial goal of this study was to reexamine the requirement of UL21 for herpes simplex virus 1 (HSV-1) replication. Previous studies suggested that UL21 is dispensable for replication in cell cultures, but a recent report on HSV-2 challenges those findings. As was done for the HSV-2 study, a UL21-null virus was made and propagated on complementing cells to discourage selection of compensating mutations. This HSV-1 mutant was able to replicate in noncomplementing cells, even at a low multiplicity of infection (MOI), though a reduction in titer was observed. Also, increased proportions of empty capsids were observed in the cytoplasm, suggesting a role for UL21 in preventing their exit from the nucleus. Surprisingly, passage of the null mutant resulted in rapid outgrowth of syncytial (Syn) variants. This was unexpected because UL21 has been shown to be required for the Syn phenotype. However, earlier experiments made use of only the A855V syncytial mutant of glycoprotein B (gB), and the Syn phenotype can also be produced by substitutions in glycoprotein K (gK), UL20, and UL24. Sequencing of the syncytial variants revealed mutations in the gK locus, but UL21 was shown to be dispensable for UL20Syn and UL24Syn. To test whether UL21 is needed only for the A855V mutant, additional gBSyn derivatives were examined in the context of the null virus, and all produced lytic rather than syncytial sites of infection. Thus, UL21 is required only for the gBSyn phenotype. This is the first example of a differential requirement for a viral protein across the four syn loci. IMPORTANCE UL21 is conserved among alphaherpesviruses, but its role is poorly understood. This study shows that HSV-1 can replicate without UL21, although the virus titers are greatly reduced. The null virus had greater proportions of empty (DNA-less) capsids in the cytoplasm of infected cells, suggesting that UL21 may play a role in retaining them in the nucleus. This is consistent with reports showing UL21 to be capsid associated and localized to the nuclei of infected cells. UL21 also appears to be needed for viral membrane activities. It was found to be required for virus-mediated cell fusion, but only for mutants that harbor syncytial mutations in gB (not variants of gK, UL20, or UL24). The machinery needed for syncytial formation is similar to that needed for direct spread of the virus through cell junctions, and these studies show that UL21 is required for cell-to-cell spread even in the absence of syncytial mutations. PMID:28794039
NASA Astrophysics Data System (ADS)
Asfarizal; Kasim, Anwar; Gunawarman; Santosa
2017-12-01
Empty Palm bunches of fiber is local ingredient in Indonesia that easy to obtain. Empty Palm bunches of fiber can be obtained from the palm oil industry such as in West Pasaman. The character of the empty Palm bunches of fiber that is strong and pliable has high-potential for particle board. To transform the large quantities of fiber become particles in size 0-10 mm requires a specially designed cut machine. Therefore, the machine is designed in two-stage system that is mechanical system, structure and cutting knife. Components that have been made, assembled and then tested to reveal the ability of the machine to cut. The results showed that the straight back and forth motion cut machine is able to cut out the empty oil palm bunches of fiber with a length 0-1 cm, 2 cm, 8 cm and the surface of the cut is not stringy. The cutting capacity is at a length of 2 cm in the result 24.4 (kg/h) and 8 cm obtained results of up to 84 (kg/h)
Energetics and sugar-feeding of field-collected anopheline females.
Holliday-Hanson, M L; Yuval, B; Washino, R K
1997-06-01
We studied the relationship between nutritional reserves and blood-feeding and sugar-feeding of Anopheles freeborni (Diptera: Culicidae) females in the field. In particular we determined whether (1) females feed on nectar before maturing eggs and initiating host-seeking and (2) the energy reserves of host-seeking females differ from those of non-fed resting females. Twenty-three percent of host-seeking females and 94 percent of gravid females were positive for nectar sugars (containing > 20 micrograms of fructose) versus 55 percent of empty (no blood or eggs) females collected in the morning and 36 percent of empty females collected in the evening. In addition, gravid females contained significantly more calories of nectar than empty, blood-fed, or partially blood-fed females collected in the morning. When the energy reserves of host-seeking and resting females were compared, no differences were found in lipid, trehalose, or glycogen. However, empty females collected in the evening contained more glycogen than empty females collected in the morning. We conclude that gravid females frequently feed on nectar and that fructose is metabolized into glycogen during the day.
Breaking a virus: Identifying molecular level failure modes of a viral capsid by multiscale modeling
NASA Astrophysics Data System (ADS)
Krishnamani, V.; Globisch, C.; Peter, C.; Deserno, M.
2016-10-01
We use coarse-grained (CG) simulations to study the deformation of empty Cowpea Chlorotic Mottle Virus (CCMV) capsids under uniaxial compression, from the initial elastic response up to capsid breakage. Our CG model is based on the MARTINI force field and has been amended by a stabilizing elastic network, acting only within individual proteins, that was tuned to capture the fluctuation spectrum of capsid protein dimers, obtained from all atom simulations. We have previously shown that this model predicts force-compression curves that match AFM indentation experiments on empty CCMV capsids. Here we investigate details of the actual breaking events when the CCMV capsid finally fails. We present a symmetry classification of all relevant protein contacts and show that they differ significantly in terms of stability. Specifically, we show that interfaces which break readily are precisely those which are believed to form last during assembly, even though some of them might share the same contacts as other non-breaking interfaces. In particular, the interfaces that form pentamers of dimers never break, while the virtually identical interfaces within hexamers of dimers readily do. Since these units differ in the large-scale geometry and, most noticeably, the cone-angle at the center of the 5- or 6-fold vertex, we propose that the hexameric unit fails because it is pre-stressed. This not only suggests that hexamers of dimers form less frequently during the early stages of assembly; it also offers a natural explanation for the well-known β-barrel motif at the hexameric center as a post-aggregation stabilization mechanism. Finally, we identify those amino acid contacts within all key protein interfaces that are most persistent during compressive deformation of the capsid, thereby providing potential targets for mutation studies aiming to elucidate the key contacts upon which overall stability rests.
Rydning, A; Berstad, A; Berstad, T; Hertzenberg, L
1985-04-01
The effect of physiological doses of guar gum (Guarem), 5 g, and fiber-enriched wheat bran (Fiberform), 10.5 g, on gastric emptying was studied by two different methods in healthy subjects: by a simple isotope localization monitor placed over the upper part of the abdomen and by gamma camera. The fiber preparations were added to a semisolid meal consisting of wheatmeal porridge and juice, using technetium-99 DTPA as a marker. The gamma camera showed no effect of fiber on gastric emptying. The isotope localization monitor, however, indicated that Fiberform prevented a postprandial accumulation of the meal within the upper part of the stomach. The simple isotope localization monitor cannot be recommended for measurements of gastric emptying.
Anker, Justin J.; Brimijoin, Stephen; Gao, Yang; Geng, Liyi; Zlebnik, Natalie E.; Parks, Robin J.; Carroll, Marilyn E.
2011-01-01
Background Cocaine dependence is a pervasive disorder with high rates of relapse. In a previous study, direct administration of a quadruple mutant albumin-fused butyrylcholinesterase (BChE) that efficiently catalyzes hydrolysis of cocaine to benzoic acid and ecgonine methyl ester acutely blocked cocaine seeking in an animal model of relapse. In the present experiments these results were extended to achieve a long duration blockade of cocaine seeking with a gene transfer paradigm using a related BChE-based cocaine hydrolase, termed “CocH”. Methods Male and female rats were allowed to self-administer cocaine under a fixed-ratio 1 schedule of reinforcement for approximately 14 days. Following the final self-administration session, rats were injected with CocH vector or a control injection (empty vector or saline), and their cocaine solutions were replaced with saline for 14 days to allow for extinction of lever pressing. Subsequently, they were tested for drug-primed reinstatement by administering i.p. injections of saline (S), cocaine (5, 10, and 15 mg/kg, C), and d-amphetamine (A) according to the following sequence: S, C, S, C, S, C, S, A. Rats then received cocaine-priming injections once weekly for 4 weeks, and subsequently, once monthly for up to 6 months. Results Administration of CocH vector produced substantial and sustained CocH activity in plasma that corresponded with diminished cocaine- (but not amphetamine-) induced reinstatement responding for up to 6 months following treatment (compared to high responding controls). Conclusion These results demonstrate that viral transfer of CocH may be useful in promoting long-term resistance to relapse to cocaine addiction. PMID:22209637
Niu, Shengniao; Gil-Salas, Francisco M.; Tewary, Sunil Kumar; Samales, Ashwin Kuppusamy; Johnson, John; Swaminathan, Kunchithapadam; Wong, Sek-Man
2014-01-01
Hibiscus chlorotic ringspot virus (HCRSV) is a member of the genus Carmovirus in the family Tombusviridae. In order to study its coat protein (CP) functions on virus replication and movement in kenaf (Hibiscus cannabinus L.), two HCRSV mutants, designated as p2590 (A to G) in which the first start codon ATG was replaced with GTG and p2776 (C to G) in which proline 63 was replaced with alanine, were constructed. In vitro transcripts of p2590 (A to G) were able to replicate to a similar level as wild type without CP expression in kenaf protoplasts. However, its cell-to-cell movement was not detected in the inoculated kenaf cotyledons. Structurally the proline 63 in subunit C acts as a kink for β-annulus formation during virion assembly. Progeny of transcripts derived from p2776 (C to G) was able to move from cell-to-cell in inoculated cotyledons but its long-distance movement was not detected. Virions were not observed in partially purified mutant virus samples isolated from 2776 (C to G) inoculated cotyledons. Removal of the N-terminal 77 amino acids of HCRSV CP by trypsin digestion of purified wild type HCRSV virions resulted in only T = 1 empty virus-like particles. Taken together, HCRSV CP is dispensable for viral RNA replication but essential for cell-to-cell movement, and virion is required for the virus systemic movement. The proline 63 is crucial for HCRSV virion assembly in kenaf plants and the N-terminal 77 amino acids including the β-annulus domain is required in T = 3 assembly in vitro. PMID:25402344
A ocean bottom vector magnetometer
NASA Astrophysics Data System (ADS)
Wang, Xiaomei; Teng, Yuntian; Wang, Chen; Ma, Jiemei
2017-04-01
The new development instrument with a compact spherical coil system and Overhauser magnetometer for measuring the total strength of the magnetic field and the vectors of strength, Delta inclination - Delta declination, meanwhile we also use a triaxial fluxgate instrument of the traditional instrument for geomagnetic vector filed measurement. The advantages of this method are be calibrated by each other and get good performances with automatic operation, good stability and high resolution. Firstly, a brief description of the instrument measurement principles and the key technologies are given. The instrument used a spherical coil system with 34 coils to product the homogeneous volume inside the coils which is large enough to accommodate the sensor of Overhauser total field sensor; the rest of the footlocker-sized ocean-bottom vector magnetometer consists of equipment to run the sensors and records its data (batteries and a data logger), weight to sink it to the sea floor, a remote-controlled acoustic release and flotation to bring the instrument back to the surface. Finally, the accuracy of the instrument was tested in the Geomagnetic station, and the measurement accuracies of total strength and components were better than 0.2nT and 1nT respectively. The figure 1 shows the development instrument structure. it includes six thick glass spheres which protect the sensor, data logger and batteries from the pressures of the deep sea, meanwhile they also provide recycling positive buoyancy; To cushion the glass, the spheres then go inside yellow plastic "hardhats". The triaxial fluxgate is inside No.1 glass spheres, data logger and batteries are inside No.2 glass spheres, the new vector sensor is inside No.3 glass spheres, acoustic communication unit is inside No.4 glass spheres, No.5 and No.6 glass spheres are empty which only provide recycling positive buoyancy. The figure 2 shows the development instrument Physical photo.
EmptyHeaded: A Relational Engine for Graph Processing
Aberger, Christopher R.; Tu, Susan; Olukotun, Kunle; Ré, Christopher
2016-01-01
There are two types of high-performance graph processing engines: low- and high-level engines. Low-level engines (Galois, PowerGraph, Snap) provide optimized data structures and computation models but require users to write low-level imperative code, hence ensuring that efficiency is the burden of the user. In high-level engines, users write in query languages like datalog (SociaLite) or SQL (Grail). High-level engines are easier to use but are orders of magnitude slower than the low-level graph engines. We present EmptyHeaded, a high-level engine that supports a rich datalog-like query language and achieves performance comparable to that of low-level engines. At the core of EmptyHeaded’s design is a new class of join algorithms that satisfy strong theoretical guarantees but have thus far not achieved performance comparable to that of specialized graph processing engines. To achieve high performance, EmptyHeaded introduces a new join engine architecture, including a novel query optimizer and data layouts that leverage single-instruction multiple data (SIMD) parallelism. With this architecture, EmptyHeaded outperforms high-level approaches by up to three orders of magnitude on graph pattern queries, PageRank, and Single-Source Shortest Paths (SSSP) and is an order of magnitude faster than many low-level baselines. We validate that EmptyHeaded competes with the best-of-breed low-level engine (Galois), achieving comparable performance on PageRank and at most 3× worse performance on SSSP. PMID:28077912
Taillefer, R; Douesnard, J M; Beauchamp, G; Guimond, J
1987-08-01
A Tc-99m albumin colloid (Tc-AC) kit has been introduced as an alternative to Tc-99m sulfur colloid (Tc-SC) for liver-spleen imaging. Since there is no need for boiling, the use of Tc-AC reduces preparation time and manipulation. Tc-SC is one of the most commonly used radiopharmaceuticals for the labeling of solid-phase markers in gastric emptying studies. In vitro studies were performed to evaluate the labeling efficiency and stability in hydrochloric acid and in human gastric juice of intracellularly labeled chicken liver and scrambled eggs labeled with Tc-SC and Tc-AC. Gastric emptying studies also were performed on 20 healthy volunteers with both Tc-SC and Tc-AC labeled scrambled egg sandwiches. There was no significant difference between Tc-SC and Tc-AC in the labeling efficiency of chicken liver (98% +/- 1% for Tc-SC, 96% +/- 2% for Tc-AC) and scrambled eggs (92% +/- 2% for Tc-SC, 91% +/- 3% for Tc-AC). However, both Tc-SC and Tc-AC labeled scrambled eggs showed a lower stability than chicken liver, particularly in human gastric juice. Gastric emptying curves from both meals in 20 normal subjects were also similar, with a mean half-emptying time of 85 +/- 13 minutes and 87 +/- 16 minutes for the meals containing Tc-SC and Tc-AC respectively. Tc-AC is a reliable alternative to Tc-SC as a radiotracer for solid-phase gastric emptying studies.
MacDonald, A; Baxter, J N; Bessent, R G; Gray, H W; Finlay, I G
1997-08-01
Idiopathic slow transit constipation (ISTC) is considered to be a heterogeneous condition in which patients have varying sites and degrees of delayed gastrointestinal transit. The majority of patients have pancolonic disease, and colectomy with ileocolorectal anastomosis has been the mainstay of surgical treatment. Severe constipation following traumatic childbirth is now being recognized and this subgroup of patients may have delayed transit confined to the rectosigmoid colon. In theory, proximal transit in these patients should be normal. Gastric emptying was studied in patients with constipation following childbirth or ISTC and in controls. After an overnight fast, both patients and controls received breakfast, which consisted of cornflakes, sugar and milk. The liquid marker 111In-labelled di-ethylene tri-amine penta-acetic acid (DTPA) was added to the milk. A solid marker, 99mTc-labelled colloid, was impregnated on to paper and sealed with cellulose. The t1/2 for gastric emptying was calculated. Liquid phase emptying was normal in both constipation following childbirth and ISTC. Solid phase emptying was delayed significantly in ISTC compared with that in patients with constipation following childbirth and controls. In addition, half the patients with ISTC had delayed transit through the small bowel and proximal colon. Small bowel and colonic transit were normal in patients with constipation following childbirth. Patients with constipation following childbirth represent a distinct subgroup with normal proximal gastrointestinal function. Gastric emptying studies may be helpful in selecting patients for surgical management of severe constipation.
Right recumbent position on gastric emptying of water evidenced by 13C breath testing
Sanaka, Masaki; Urita, Yoshihisa; Yamamoto, Takatsugu; Shirai, Tsuguru; Kimura, Satoshi; Aoyagi, Hitoshi; Kuyama, Yasushi
2013-01-01
AIM: To compare the impact of the right recumbent position with the sitting position on gastric emptying of water. METHODS: In eight healthy male volunteers, the 13C acetate breath test was performed twice to assess gastric emptying of 100 mL tap water. Subjects were seated in one test and lying on their right side in the other. In both positions, pulmonary 13CO2 exhalation curves were obtained by plotting breath data against time. Percent gastric retention curves were created by analyzing data using the Wagner-Nelson protocol. RESULTS: No significant posture effect was found in pulmonary 13CO2 output curves (P = 0.2150), whereas a significant effect was seen in gastric retention curves (P = 0.0315). The percent retention values at 10 min and 15 min were significantly smaller when subjects were in the right recumbent position compared with the seated position (P < 0.05). Our results verified the accelerating effect of the right recumbent position on gastric emptying of non-nutritive solutions. Concerning clinical implications, this study suggests that placing patients with acute pain on their right side after oral administration of analgesic drugs in solution is justified as an effective practice for rapid pain relief. For patients with gastrointestinal reflux symptoms, sleeping in the right recumbent position may reduce nocturnal symptoms, as delayed gastric emptying can cause reflux symptoms. CONCLUSION: Gastric emptying of water occurs more quickly when a subject lies on the right side compared with sitting. PMID:23372358
Interspecies differences in the empty body chemical composition of domestic animals.
Maeno, H; Oishi, K; Hirooka, H
2013-07-01
Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aX b , was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained except for dogs. The fraction of empty body energy gain retained as fat increased in a curvilinear manner, and there was little variation among farm animals at the same fat content of the empty body. These findings may provide the opportunity to develop a general model to predict empty body composition across farm animal species. In contrast, there were considerable differences of chemical body composition between farm and laboratory animals.
Effect of guar gum on gastric emptying of test meals of varying energy content in growing pigs.
Rainbird, A L
1986-01-01
1. Existing information on whether the action of guar gum in decreasing postprandial blood glucose concentrations is due, at least in part, to a reduced rate of gastric emptying is conflicting, possibly because three types of test meals have been used. In order to test whether the type of test meal used influences the action of guar gum, these three types of meal were compared, either without or with guar gum, in growing pigs. The meals were: a high-energy meal (HEM), a low-energy milky drink (LEMD) and a glucose drink (GD). 2. Six pigs were prepared with a simple gastric cannula which allowed complete removal of the stomach contents just before or 0.5, 1, 2 or 4 h after feeding. 3. The three types of test meal without guar gum gave rise to very different postprandial profiles of gastric pH and of digesta and dry matter (DM) emptying from the stomach. 4. Addition of guar gum to the GD significantly raised gastric pH at 0.5 and 1 h after feeding but, when it was added to HEM, gastric pH was only significantly raised 4 h after feeding. No significant effect on gastric pH was seen when guar gum was added to LEMD. 5. Although addition of guar gum to GD had no significant effect on the emptying of digesta from the stomach, when added to HEM the rate of emptying of digesta was significantly reduced 1, 2 and 4 h after feeding. Addition of guar gum to LEMD only significantly increased the amount of digesta remaining in the stomach 2 h after feeding. 6. There was no significant effect on the emptying of DM from the stomach when guar gum was added to either HEM or LEMD. However, addition of guar gum to GD significantly reduced the mean rate of emptying of DM 0.5 h after feeding. 7. Addition of guar gum to either LEMD or GD had no significant effect on the DM concentration of the evacuated gastric digesta. However, addition of guar gum to HEM significantly lowered the DM concentration of the evacuated gastric digesta 1, 2 and 4 h after feeding. 8. It was concluded that differences in test meal composition and also in the methods used to measure gastric emptying could account for the discrepancies previously reported. The results suggest that although guar gum may reduce the rate of gastric emptying under some conditions, this is unlikely to be the only mechanism by which it acts.
Shin, Andrea; Camilleri, Michael; Busciglio, Irene; Burton, Duane; Smith, Steven A; Vella, Adrian; Ryks, Michael; Rhoten, Deborah; Zinsmeister, Alan R
2013-11-01
RM-131, a synthetic ghrelin agonist, greatly accelerates gastric emptying of solids in patients with type 2 diabetes and delayed gastric emptying (DGE). We investigated the safety and effects of a single dose of RM-131 on gastric emptying and upper gastrointestinal (GI) symptoms in patients with type 1 diabetes and previously documented DGE. In a double-blind cross-over study, 10 patients with type 1 diabetes (age, 45.7 ± 4.4 y; body mass index, 24.1 ± 1.1 kg/m(2)) and previously documented DGE were assigned in random order to receive a single dose of RM-131 (100 μg, subcutaneously) or placebo. Thirty minutes later, they ate a radiolabeled solid-liquid meal containing EggBeaters (ConAgra Foods, Omaha, NE), and then underwent 4 hours of gastric emptying and 6 hours of colonic filling analyses by scintigraphy. Upper GI symptoms were assessed using a daily diary, gastroparesis cardinal symptom index (total GCSI-DD) and a combination of nausea, vomiting, fullness, and pain (NVFP) scores (each rated on a 0-5 scale). At screening, participants' mean level of hemoglobin A1c was 9.1% ± 0.5%; their total GCSI-DD score was 1.66 ± 0.38 (median, 1.71), and their total NVFP score was 1.73 ± 0.39 (median, 1.9). The t1/2 of solid gastric emptying was 84.9 ± 31.6 minutes when subjects were given RM-131 and 118.7 ± 26.7 when they were given a placebo. The median difference (Δ)was 33.9 minutes (interquartile range [IQR] -12, -49), or -54.7% (IQR, -21%,-110%). RM-131 decreased gastric retention of solids at 1 hour (P = .005) and 2 hours (P = .019). Numeric differences in t1/2 for gastric emptying of liquids, solid gastric emptying lag time, and colonic filling at 6 hours were not significant. Total GCSI-DD scores were 0.79 on placebo (IQR, 0.75, 2.08) and 0.17 on RM-131 (IQR, 0.00, 0.67; P = .026); NVFP scores were lower on RM-131 (P = .041). There were no significant adverse effects. RM-131 significantly accelerates gastric emptying of solids and reduces upper GI symptoms in patients with type 1 diabetes and documented DGE. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.
Effect of DA-9701 on gastric emptying in a mouse model: assessment by ¹³C-octanoic acid breath test.
Lim, Chul-Hyun; Choi, Myung-Gyu; Park, Hyeyeon; Baeg, Myong Ki; Park, Jae Myung
2013-07-21
To evaluate the effects of DA-9701 on the gastric emptying of a solid meal using the ¹³C-octanoic acid breath test in a mouse model. Male C57BL/6 mice aged > 8 wk and with body weights of 20-25 g were used in this study. The solid test meal consisted of 200 mg of egg yolk labeled with 1.5 L/g ¹³C-octanoic acid. The mice were placed in a 130 mL chamber flushed with air at a flow speed of 200 mL/min. Breath samples were collected for 6 h. The half-emptying time and lag phase were calculated using a modified power exponential model. To assess the reproducibility of the ¹³C-octanoic acid breath test, the breath test was performed two times at intervals of one week in ten mice without drug treatment. To assess the gastrokinetic effects of DA-9701, the breath test was performed three times in another twelve mice, with a randomized crossover sequence of three drug treatments: DA-9701 3 mg/kg, erythromycin 6 mg/kg, or saline. Each breath test was performed at an interval of one week. Repeatedly measured half gastric emptying time of ten mice without drug treatment showed 0.856 of the intraclass correlation coefficient for the half gastric emptying time (P = 0.004). The mean cumulative excretion curve for the ¹³C-octanoic acid breath test showed accelerated gastric emptying after DA-9701 treatment compared with the saline control (P = 0.028). The median half gastric emptying time after the DA-9701 treatment was significantly shorter than after the saline treatment [122.4 min (109.0-137.9 min) vs 134.5 min (128.4-167.0 min), respectively; P = 0.028] and similar to that after the erythromycin treatment [123.3 min (112.9-138.2 min)]. The lag phase, which was defined as the period taken to empty 15% of a meal, was significantly shorter after the DA-9701 treatment than after the saline treatment [48.1 min (44.6-57.1 min) vs 52.6 min (49.45-57.4 min), respectively; P = 0.049]. The novel prokinetic agent DA-9701 accelerated gastric emptying, assessed with repeated measurements in the same mouse using the ¹³C-octanoic acid breath test. Our findings suggest that DA-9701 has therapeutic potential for the treatment of functional dyspepsia.
Gastric emptying rate and chyme characteristics for cooked brown and white rice meals in vivo.
Bornhorst, Gail M; Chang, Lucy Q; Rutherfurd, Shane M; Moughan, Paul J; Singh, R Paul
2013-09-01
Rice structure is important to rice grain and starch breakdown during digestion. The objective of this study was to determine the gastric emptying and rice composition during gastric digestion of cooked brown and white medium-grain (Calrose variety) rice using the growing pig as a model for the adult human. Brown and white rice did not show significantly different gastric emptying rates of dry matter or starch, but brown rice had slower protein emptying (P < 0.05). Moisture content was greater and pH was lower in the distal stomach compared to the proximal stomach (P < 0.0001), and varied with time (P < 0.0001). The mechanism of physical breakdown for brown and white rice varied. Brown rice exhibited an accumulation of bran layer fragments in the distal stomach, quantified by lower starch and higher protein content. The quantity of gastric secretions observed after a brown or white rice meal may be related to the meal buffering capacity, and are accumulated in the distal stomach. The delayed rate of protein emptying in brown rice compared to white rice was most likely due to the accumulation of bran layers in the stomach. © 2013 Society of Chemical Industry.
Eating behavior and gastric emptying in adults with Prader-Willi syndrome.
Hoybye, Charlotte; Barkeling, Britta; Naslund, Erik; Thorén, Marja; Hellstrom, Per M
2007-01-01
Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by distinctive physical, behavioral and psychiatric features. One cardinal symptom is excessive eating, often leading to extreme obesity. The etiology of the hyperphagia is unknown, but eating behaviors and gastrointestinal motility could play a pivotal role. In this pilot study, we therefore sought to give a closer description of the two. 12 PWS adults, 6 men and 6 women, 17-37 years of age with a median BMI of 34.9 were evaluated. Computerized monitoring of eating behavior and assessment of gastric emptying using paracetamol absorption were analyzed. Gastric emptying rate was compared to the rate in normal and obese controls. Eating behavior pattern was nonhomogeneous in the PWS patients, but they experienced both hunger and satiation. In PWS gastric emptying was similar to lean subjects (p > 0.05), but longer than in obese subjects (p < 0.05). Despite obesity, this group of adults with PWS did not display overeating in the test situation and gastric emptying rate was normal. Numbers are small, but the results are important for the treatment of obesity in this special group of patients. Copyright 2007 S. Karger AG, Basel.
Beneficial effects of naloxone in a patient with intestinal pseudoobstruction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schang, J.C.; Devroede, G.
1985-06-01
A 15-day course of Naloxone treatment was given to a patient with intestinal pseudoobstruction who had previously undergone subtotal colectomy with terminal ileostomy for invalidating constipation. The effects of the drug were assessed according to symptoms, by recording the myoelectric activity of the stomach, and by measuring gastric emptying of a radiolabeled solid-liquid meal and the intestinal transit time of radiopaque markers. All tests were performed 1) at baseline; 2) after 2 wk with Naloxone 1.6 mg subcutaneous per day; and 3) after 8 days of placebo. Results showed that before treatment gastric emptying of solids was delayed, emptying ofmore » liquids was normal, myoelectric activity of the stomach was normal, small intestinal transit time of radiopaque markers was considerably increased while ileal output was markedly decreased. After Naloxone, gastric emptying of solids was markedly accelerated, emptying of liquids remained normal, gastric electrical spiking activity increased, small intestinal transit time strikingly decreased, and ileal output increased. After placebo, a tendency to return to pretreatment values was observed. This observation suggests that Naloxone may be helpful in the treatment of some patients with intestinal pseudoobstruction.« less
Research requirements to reduce empty weight of helicopters by use of advanced materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoffstedt, D.J.
1976-12-01
Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12% at recurring costs competetive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12% was shown to significantly reduce energy consumption in modern high-performance helicopters.
Selective Gene Regulation by Androgen Receptor in Prostate Cancer
2012-10-01
empty vector, wt AR, AR-E255K and AR- R753Q cells were transfected with an ARE- responsive reporter and renilla as control. Cells were treated with...empty vector (empty), wild-type AR (WT), AR-E255K or AR-R753Q were transfected with ARE-luciferase and renilla . Cells were treated with 0 or 1 nm...R1881, harvested after 24 hrs to read luciferase and renilla actiivity. % G ro w th (D ay 5 / D ay 1 ) Vector WTAR E255KR753Q 600 700 800 900
A Protein Preload Enhances the Glucose-Lowering Efficacy of Vildagliptin in Type 2 Diabetes.
Wu, Tongzhi; Little, Tanya J; Bound, Michelle J; Borg, Malcolm; Zhang, Xiang; Deacon, Carolyn F; Horowitz, Michael; Jones, Karen L; Rayner, Christopher K
2016-04-01
Nutrient "preloads" given before meals can attenuate postprandial glycemic excursions, at least partly by slowing gastric emptying and stimulating secretion of the incretins (i.e., glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]). This study was designed to evaluate whether a protein preload could improve the efficacy of the dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin to increase incretin concentrations, slow gastric emptying, and lower postprandial glycemia in type 2 diabetes. Twenty-two patients with type 2 diabetes treated with metformin were studied on four occasions, receiving either 50 mg vildagliptin (VILD) or placebo (PLBO) on both the evening before and the morning of each study day. The latter dose was followed after 60 min by a preload drink containing either 25 g whey protein (WHEY) or control flavoring (CTRL), and after another 30 min by a (13)C-octanoate-labeled mashed potato meal. Plasma glucose and hormones, and gastric emptying, were evaluated. Compared with PLBO/CTRL, PLBO/WHEY reduced postprandial peak glycemia, increased plasma insulin, glucagon, and incretin hormones (total and intact), and slowed gastric emptying, whereas VILD/CTRL reduced both the peak and area under the curve for glucose, increased plasma intact incretins, and slowed gastric emptying but suppressed plasma glucagon and total incretins (P < 0.05 each). Compared with both PLBO/WHEY and VILD/CTRL, VILD/WHEY was associated with higher plasma intact GLP-1 and GIP, slower gastric emptying, and lower postprandial glycemia (P < 0.05 each). In metformin-treated type 2 diabetes, a protein preload has the capacity to enhance the efficacy of vildagliptin to slow gastric emptying, increase plasma intact incretins, and reduce postprandial glycemia. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.
Reedy, Jill; Krebs-Smith, Susan M
2010-10-01
The objective of this research was to identify top dietary sources of energy, solid fats, and added sugars among 2- to 18-year-olds in the United States. Data from the National Health and Nutrition Examination Survey, a cross-sectional study, were used to examine food sources (percentage contribution and mean intake with standard errors) of total energy (data from 2005-2006) and energy from solid fats and added sugars (data from 2003-2004). Differences were investigated by age, sex, race/ethnicity, and family income, and the consumption of empty calories-defined as the sum of energy from solid fats and added sugars-was compared with the corresponding discretionary calorie allowance. The top sources of energy for 2- to 18-year-olds were grain desserts (138 kcal/day), pizza (136 kcal/day), and soda (118 kcal/day). Sugar-sweetened beverages (soda and fruit drinks combined) provided 173 kcal/day. Major contributors varied by age, sex, race/ethnicity, and income. Nearly 40% of total energy consumed (798 of 2,027 kcal/day) by 2- to 18-year-olds were in the form of empty calories (433 kcal from solid fat and 365 kcal from added sugars). Consumption of empty calories far exceeded the corresponding discretionary calorie allowance for all sex-age groups (which range from 8% to 20%). Half of empty calories came from six foods: soda, fruit drinks, dairy desserts, grain desserts, pizza, and whole milk. There is an overlap between the major sources of energy and empty calories: soda, grain desserts, pizza, and whole milk. The landscape of choices available to children and adolescents must change to provide fewer unhealthy foods and more healthy foods with less energy. Identifying top sources of energy and empty calories can provide targets for changes in the marketplace and food environment. However, product reformulation alone is not sufficient-the flow of empty calories into the food supply must be reduced.
Itopride for gastric volume, gastric emptying and drinking capacity in functional dyspepsia
Abid, Shahab; Jafri, Wasim; Zaman, Maseeh Uz; Bilal, Rakhshanda; Awan, Safia; Abbas, Aamir
2017-01-01
AIM To study the effect of itopride on gastric accommodation, gastric emptying and drinking capacity in functional dyspepsia (FD). METHODS Randomized controlled trial was conducted to check the effect of itopride on gastric accommodation, gastric emptying, capacity of tolerating nutrient liquid and symptoms of FD. We recruited a total of 31 patients having FD on the basis of ROME III criteria. After randomization, itopride was received by 15 patients while 16 patients received placebo. Gastric accommodation was determined using Gastric Scintigraphy. 13C labeled octanoic breadth test was performed to assess gastric emptying. Capacity of tolerating nutrient liquid drink was checked using satiety drinking capacity test. The intervention group comprised of 150 mg itopride. Patients in both arms were followed for 4 wk. RESULTS Mean age of the recruited participant 33 years (SD = 7.6) and most of the recruited individuals, i.e., 21 (67.7%) were males. We found that there was no effect of itopride on gastric accommodation as measured at different in volumes in the itopride and control group with the empty stomach (P = 0.14), at 20 min (P = 0.38), 30 min (P = 0.30), 40 min (P = 0.43), 50 min (P = 0.50), 60 min (P = 0.81), 90 min (P = 0.25) and 120 min (P = 0.67). Gastric emptying done on a sub sample (n = 11) showed no significant difference (P = 0.58) between itopride and placebo group. There was no significant improvement in the capacity to tolerate liquid in the itopride group as compared to placebo (P = 0.51). Similarly there was no significant improvement of symptoms as assessed through a composite symptom score (P = 0.74). The change in QT interval in itopride group was not significantly different from placebo (0.10). CONCLUSION Our study found no effect of itopride on gastric accommodation, gastric emptying and maximum tolerated volume in patients with FD. PMID:28217377
Itopride for gastric volume, gastric emptying and drinking capacity in functional dyspepsia.
Abid, Shahab; Jafri, Wasim; Zaman, Maseeh Uz; Bilal, Rakhshanda; Awan, Safia; Abbas, Aamir
2017-02-06
To study the effect of itopride on gastric accommodation, gastric emptying and drinking capacity in functional dyspepsia (FD). Randomized controlled trial was conducted to check the effect of itopride on gastric accommodation, gastric emptying, capacity of tolerating nutrient liquid and symptoms of FD. We recruited a total of 31 patients having FD on the basis of ROME III criteria. After randomization, itopride was received by 15 patients while 16 patients received placebo. Gastric accommodation was determined using Gastric Scintigraphy. 13 C labeled octanoic breadth test was performed to assess gastric emptying. Capacity of tolerating nutrient liquid drink was checked using satiety drinking capacity test. The intervention group comprised of 150 mg itopride. Patients in both arms were followed for 4 wk. Mean age of the recruited participant 33 years (SD = 7.6) and most of the recruited individuals, i.e ., 21 (67.7%) were males. We found that there was no effect of itopride on gastric accommodation as measured at different in volumes in the itopride and control group with the empty stomach ( P = 0.14), at 20 min ( P = 0.38), 30 min ( P = 0.30), 40 min ( P = 0.43), 50 min ( P = 0.50), 60 min ( P = 0.81), 90 min ( P = 0.25) and 120 min ( P = 0.67). Gastric emptying done on a sub sample ( n = 11) showed no significant difference ( P = 0.58) between itopride and placebo group. There was no significant improvement in the capacity to tolerate liquid in the itopride group as compared to placebo ( P = 0.51). Similarly there was no significant improvement of symptoms as assessed through a composite symptom score ( P = 0.74). The change in QT interval in itopride group was not significantly different from placebo (0.10). Our study found no effect of itopride on gastric accommodation, gastric emptying and maximum tolerated volume in patients with FD.
Reedy, Jill; Krebs-Smith, Susan M.
2010-01-01
Objective The objective of this research was to identify top dietary sources of energy, solid fats, and added sugars among 2–18 year olds in the United States. Methods Data from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional study, were used to examine food sources (percentage contribution and mean intake with standard errors) of total energy (2005–06) and calories from solid fats and added sugars (2003–04). Differences were investigated by age, sex, race/ethnicity, and family income, and the consumption of empty calories—defined as the sum of calories from solid fats and added sugars—was compared with the corresponding discretionary calorie allowance. Results The top sources of energy for 2–18 year olds were grain desserts (138 kcal/day), pizza (136 kcal), and soda (118 kcal). Sugar-sweetened beverages (soda and fruit drinks combined) provided 173 kcal/day. Major contributors varied by age, sex, race/ethnicity, and income. Nearly 40% of total calories consumed (798 kcal/day of 2027 kcal) by 2–18 year olds were in the form of empty calories (433 kcal from solid fat and 365 kcal from added sugars). Consumption of empty calories far exceeded the corresponding discretionary calorie allowance for all sex-age groups (which range from 8–20%). Half of empty calories came from six foods: soda, fruit drinks, dairy desserts, grain desserts, pizza, and whole milk. Conclusion There is an overlap between the major sources of energy and empty calories: soda, grain desserts, pizza, and whole milk. The landscape of choices available to children and adolescents must change to provide fewer unhealthy foods and more healthy foods with fewer calories. Identifying top sources of energy and empty calories can provide targets for changes in the marketplace and food environment. However, product reformulation alone is not sufficient—the flow of empty calories into the food supply must be reduced. PMID:20869486
Frost, G S; Brynes, A E; Dhillo, W S; Bloom, S R; McBurney, M I
2003-02-01
To assess whether the addition of viscous fiber at an amount recommended by the US FDA to allow a 'low saturated fat, cholesterol, soluble fiber and coronary heart disease', health claim label on a food package (1.7 g psyllium) and/or fat (30 g sunflower oil and 3 g sodium propionate) to a pasta meal would affect gastric emptying, postprandial glucose, insulin and GLP-1 concentrations. Ten subjects participated in a two-by-two single blind randomized crossover study. Four meals containing 50 g of available carbohydrate were consumed: pasta with or without psyllium enrichment served with a tomato sauce with (520 kcal per meal) and without (240 kcal per meal) fat. Blood samples were taken for 240 min following the meal and all subjects consumed a buffet meal at the end of the study. Gastric emptying was measured using the paracetamol absorption test. Blood was analysed for glucose, insulin, GLP-1. Visual analog scales were used to record feelings of hunger, pleasantness and nausea. The psyllium-enriched pasta had no significant effect on gastric emptying or the incremental area under the curve (IAUC) for GLP-1, insulin or glucose compared with the control pasta. The addition of polyunsaturated fat and sodium propionate significantly increased the IAUC for GLP-1 (P<0.001), delaying gastric emptying (P<0.002), and decreasing glucose (P<0.002). A dose of 1.7 g psyllium did not evoke measurable effects on gastric emptying, postprandial GLP-1, insulin or glucose metabolism. However the addition of 30 g of oil and 3 g of sodium propionate to the pasta did reduce gastric emptying, increase GLP-1 and reduce glucose and insulin concentrations. While this short-term study may have implications in terms of reducing the risk of diabetes and improving coronary risk factor profiles the long term effects of these nutrients need to be studied.
PRN 94-2: Recycling Empty Aerosol Pesticide Containers
This notice offers registrants use of an optional label statement permitting recycling as an alternative to instructions to dispose of aerosol pesticide containers. Registrants may add a label reference to recycling the empty aerosol pesticide container.
NASA Astrophysics Data System (ADS)
Hanum, H.; Lisnawita; Tantawi, A. R.
2018-02-01
Using of Ganoderma endemic soil in oil palm main nursery is not recomended because produce bad quality seedling. The application of organic and anorganic fertilizer and endophytic microbes are the alternative for solving the problem. The objective of this research is to evaluate the effect of empty fruit bunches compost, anorganic fertilizer and endophytic microbes on growth of oil palm seedling in main nursery. This research used factorial randomized block design. The first factor was combination of empty fruit bunches compost and anorganic fertilizer, The second factor was endophytic microbes consisting of Trichoderma and Aspergillus. The results showed that interaction effect of the both treatment factor used increased growth of seedling in third and fourth month after application. The best growth of seedling was on the treatment of empty fruit bunches compost combined with anorganic fertilizer 150% recommended dosage and Trichoderma viride.
Kris, M G; Yeh, S D; Gralla, R J; Young, C W
1986-01-01
To develop an additional method for the measurement of gastric emptying in supine subjects, 10 normal subjects were given a test meal containing 99Tc-labelled scrambled egg as the "solid" phase marker and 111In in tapwater as the marker for the "liquid" phase. The mean time for emptying 50% of the "solid" phase (t1/2) was 85 min and 29 min for the "liquid" phase. Three individuals were restudied with a mean difference between the two determinations of 10.8% for the "solid" phase and 6.5% for the "liquid" phase. Twenty-six additional studies attempted have been successfully completed in symptomatic patients with advanced cancer. This method provides a simple and reproducible procedure for the determination of gastric emptying that yields results similar to those reported for other test meals and can be used in debilitated patients.
Misleading inferences from discretization of empty spacetime: Snyder-noncommutativity case study
NASA Astrophysics Data System (ADS)
Amelino-Camelia, Giovanni; Astuti, Valerio
2015-06-01
Alternative approaches to the study of the quantum gravity problem are handling the role of spacetime very differently. Some are focusing on the analysis of one or another novel formulation of "empty spacetime", postponing to later stages the introduction of particles and fields, while other approaches assume that spacetime should only be an emergent entity. We here argue that recent progress in the covariant formulation of quantum mechanics, suggests that empty spacetime is not physically meaningful. We illustrate our general thesis in the specific context of the noncommutative Snyder spacetime, which is also of some intrinsic interest, since hundreds of studies were devoted to its analysis. We show that empty Snyder spacetime, described in terms of a suitable kinematical Hilbert space, is discrete, but this is only a formal artifact: the discreteness leaves no trace on the observable properties of particles on the physical Hilbert space.
Hausken, T; Li, X N; Goldman, B; Leotta, D; Ødegaard, S; Martin, R W
2001-07-01
To develop a non-invasive method for evaluating gastric emptying and duodenogastric reflux stroke volumes using three-dimensional (3D) guided digital color Doppler imaging. The technique involved color Doppler digital images of transpyloric flow in which the 3D position and orientation of the images were known by using a magnetic location system. In vitro, the system was found to slightly underestimate the reference flow (by average 8.8%). In vivo (five volunteers), stroke volume of gastric emptying episodes lasted on average only 0.69 s with a volume on average of 4.3 ml (range 1.1-7.4 ml), and duodenogastric reflux episodes on average 1.4 s with a volume of 8.3 ml (range 1.3-14.1 ml). With the appropriate instrument settings, orientation determined color Doppler can be used for stroke volume quantification of gastric emptying and duodenogastric reflux episodes.
Yates, M V; Yates, S R; Warrick, A W; Gerba, C P
1986-01-01
Water samples were collected from 71 public drinking-water supply wells in the Tucson, Ariz., basin. Virus decay rates in the water samples were determined with MS-2 coliphage as a model virus. The correlations between the virus decay rates and the sample locations were shown by fitting a spherical model to the experimental semivariogram. Kriging, a geostatistical technique, was used to calculate virus decay rates at unsampled locations by using the known values at nearby wells. Based on the regional characteristics of groundwater flow and the kriged estimates of virus decay rates, a contour map of the area was constructed. The map shows the variation in separation distances that would have to be maintained between wells and sources of contamination to afford similar degrees of protection from viral contamination of the drinking water in wells throughout the basin. PMID:3532954
Nauck, Michael A.; Kemmeries, Guido; Holst, Jens J.; Meier, Juris J.
2011-01-01
OBJECTIVE Glucagon-like peptide (GLP)-1 lowers postprandial glycemia primarily through inhibition of gastric emptying. We addressed whether the GLP-1–induced deceleration of gastric emptying is subject to rapid tachyphylaxis and if so, how this would alter postprandial glucose control. RESEARCH DESIGN AND METHODS Nine healthy volunteers (25 ± 4 years old, BMI: 24.6 ± 4.7 kg/m2) were examined with intravenous infusion of GLP-1 (0.8 pmol · kg−1 . min−1) or placebo over 8.5 h. Two liquid mixed meals were administered at a 4-h interval. Gastric emptying was determined, and blood samples were drawn frequently. RESULTS GLP-1 decelerated gastric emptying significantly more after the first meal compared with the second meal (P = 0.01). This was associated with reductions in pancreatic polypeptide levels (marker of vagal activation) after the first but not the second meal (P < 0.05). With GLP-1, glucose concentrations declined after the first meal but increased after the second meal (P < 0.05). The GLP-1–induced reductions in postprandial insulin and C-peptide levels were stronger during the first meal course (P < 0.05). Likewise, glucagon levels were lowered by GLP-1 after the first meal but increased after the second test meal (P < 0.05). CONCLUSIONS The GLP-1–induced delay in gastric emptying is subject to rapid tachyphylaxis at the level of vagal nervous activation. As a consequence, postprandial glucose control by GLP-1 is attenuated after its chronic administration. PMID:21430088
Spontaneous nasal cerebrospinal fluid leaks and empty sella syndrome: a clinical association.
Schlosser, Rodney J; Bolger, William E
2003-01-01
Spontaneous, idiopathic nasal meningoencephaloceles are herniations of arachnoid/dura and cerebrospinal fluid (CSF) through anatomically fragile sites within the skull base. Empty sella syndrome occurs when intracranial contents herniate through the sellar diaphragm filling the sella turcica with CSF and giving the radiographic appearance of an absent pituitary gland. The objective of this study was to examine the association between spontaneous encephaloceles/CSF leaks and empty sella syndrome because of their similar clinical features and potential common pathophysiology. Retrospective. Sixteen patients were treated for spontaneous encephaloceles between 1996 and 2001. All 16 patients had associated CSF leaks. Five patients had multiple simultaneous encephaloceles. Fifteen patients with imaging of the sella turcica had empty (10 patients) or partially empty (5 patients) sellas. One patient did not have complete imaging of the sella. Three patients had lumbar punctures with measurement of CSF pressure during computed tomography cisternograms because of multiple skull base defects. Mean CSF pressure was 28.3 cm of water (range, 19-34 cm; normal, 0-15 cm). Thirteen of 16 patients (81%) were obese women (mean body mass index 35.9 kg/m2; normal, <25 kg/m2). Mean follow-up was 14.2 months with 100% success in closure of the defects after one procedure. Spontaneous meningoencephaloceles and CSF leaks are strongly associated with radiographic findings of an empty sella and suggest a common pathophysiology. The underlying condition probably represents a form of intracranial hypertension that exerts hydrostatic pressure at anatomically weakened sites within the skull base. Otolaryngologists should be familiar with this disease entity and the implications intracranial hypertension has on patient management.
Effect of gum chewing on gastric volume and emptying: a prospective randomized crossover study.
Bouvet, L; Loubradou, E; Desgranges, F-P; Chassard, D
2017-11-01
Current fasting guidelines allow oral intake of water up to 2 h before induction of anaesthesia. We assessed whether gum chewing affects gastric emptying of 250 ml water and residual gastric fluid volume measured 2 h after ingestion of water. This prospective randomized observer-blind crossover trial was performed on 20 healthy volunteers who attended two separate study sessions: Control and Chewing gum (chlorophyll flavour, with 2.1 g carbohydrate). Each session started with an ultrasound measurement of the antral area, followed by drinking 250 ml water. Then, volunteers either chewed a sugared gum for 45 min (Chewing gum) or did not (Control). Serial measurements of the antral area were performed during 120 min, and the half-time to gastric emptying (t½), total gastric emptying time, and gastric fluid volume before ingestion of water and 120 min later were calculated. Gastric emptying of water was not different between sessions; the mean (sdsd) t½ was 23 (10) min in the Control session and 21 (7) min in the Chewing gum session (P=0.52). There was no significant difference between sessions in gastric fluid volumes measured before ingestion of water and 120 min later. Chewing gum does not affect gastric emptying of water and does not change gastric fluid volume measured 2 h after ingestion of water. NCT02673307. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Koch, K L; Bingaman, S; Tan, L; Stern, R M
1998-02-01
Bulimia nervosa remains a common eating disorder in young women. Little is known about upper gastrointestinal symptoms or gastric motility in patients with bulimia nervosa. The aim of this study was to measure gastric myoelectrical activity and hunger/satiety and stomach emptiness/fullness before and after a non-nutrient water load and solid-phase gastric emptying in hospitalized patients with bulimia nervosa (n = 12) and in healthy women (n = 13). Gastric myoelectrical activity was measured by means of cutaneous electrodes; visual analogue scales were used to measure perceptions of hunger/satiety and stomach emptiness/fullness. Before and after a standard water load the bulimia patients reported significantly greater stomach fullness and satiety compared with control subjects (P < 0.01). The percentage of gastric myoelectrical power in the normal 3 cpm range was significantly less in bulimics compared with controls. Power in the 1-2 cpm bradygastria range was significantly greater in bulimia patients before and after the water load compared with the control subjects (P < 0.05). Solid-phase gastric emptying studies using radio-isotope-labelled scrambled eggs showed the lag phase was shortened in the bulimic patients (16 +/- 4 min vs 31 +/- 4 min in controls, P < 0.01), but the percentage of meal emptied at 2 h was similar to control values. bulimia patients had exaggerated perceptions of stomach fullness and satiety in response to water; and abnormal gastric myoelectrical activity and accelerated lag phase of gastric emptying were objective stomach abnormalities detected in hospitalized patients with bulimia nervosa.
Yeh, Chun; Ting, Ching-Heng; Doong, Ming-Luen; Chi, Chin-Wen; Lee, Shou-Dong; Chen, Chih-Yen
2016-01-01
Purpose Urocortin 3 is a key neuromodulator in the regulation of stress, anxiety, food intake, gut motility, and energy homeostasis, while ghrelin elicits feeding behavior and enhances gastric emptying, adiposity, and positive energy balance. However, the interplays between urocortin 3 and ghrelin on food intake and gastric emptying remain uninvestigated. Methods We examined the differential effects of central O-n-octanoylated ghrelin, des-Gln14-ghrelin, and urocortin 3 on food intake, as well as on charcoal nonnutrient semiliquid gastric emptying in conscious rats that were chronically implanted with intracerebroventricular (ICV) catheters. The functional importance of corticotropin-releasing factor (CRF) receptor 2 in urocortin 3-induced responses was examined by ICV injection of the selective CRF receptor 2 antagonist, astressin2-B. Results ICV infusion of urocortin 3 opposed central acyl ghrelin-elicited hyperphagia via CRF receptor 2 in satiated rats. ICV injection of O-n-octanoylated ghrelin and des-Gln14-ghrelin were equally potent in accelerating gastric emptying in fasted rats, whereas ICV administration of urocortin 3 delayed gastric emptying. In addition, ICV infusion of urocortin 3 counteracted central acyl ghrelin-induced gastroprokinetic effects via CRF receptor 2 pathway. Conclusion ICV-infused urocortin 3 counteracts central acyl ghrelin-induced hyperphagic and gastroprokinetic effects via CRF receptor 2 in rats. Our results clearly showed that enhancing ghrelin and blocking CRF receptor 2 signaling in the brain accelerated gastric emptying, which provided important clues for a new therapeutic avenue in ameliorating anorexia and gastric ileus found in various chronic wasting disorders. PMID:27757017
Indoor A* Pathfinding Through an Octree Representation of a Point Cloud
NASA Astrophysics Data System (ADS)
Rodenberg, O. B. P. M.; Verbree, E.; Zlatanova, S.
2016-10-01
There is a growing demand of 3D indoor pathfinding applications. Researched in the field of robotics during the last decades of the 20th century, these methods focussed on 2D navigation. Nowadays we would like to have the ability to help people navigate inside buildings or send a drone inside a building when this is too dangerous for people. What these examples have in common is that an object with a certain geometry needs to find an optimal collision free path between a start and goal point. This paper presents a new workflow for pathfinding through an octree representation of a point cloud. We applied the following steps: 1) the point cloud is processed so it fits best in an octree; 2) during the octree generation the interior empty nodes are filtered and further processed; 3) for each interior empty node the distance to the closest occupied node directly under it is computed; 4) a network graph is computed for all empty nodes; 5) the A* pathfinding algorithm is conducted. This workflow takes into account the connectivity for each node to all possible neighbours (face, edge and vertex and all sizes). Besides, a collision avoidance system is pre-processed in two steps: first, the clearance of each empty node is computed, and then the maximal crossing value between two empty neighbouring nodes is computed. The clearance is used to select interior empty nodes of appropriate size and the maximal crossing value is used to filter the network graph. Finally, both these datasets are used in A* pathfinding.
61. View of bellmouth which empties into Printz Basin, looking ...
61. View of bellmouth which empties into Printz Basin, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA
5 Ways to Avoid Filling Up on Empty Calories
It's easy to get overwhelmed by our busy lives and grab food on the go that doesn’t provide the nourishment our bodies need. Pretty much anything you would call “junk food” is an empty-calorie culprit.
Effects of gastric pacing on gastric emptying and plasma motilin
Yang, Min; Fang, Dian-Chun; Li, Qian-Wei; Sun, Nian-Xu; Long, Qing-Lin; Sui, Jian-Feng; Gan, Lu
2004-01-01
AIM: To investigate the effects of gastric pacing on gastric emptying and plasma motilin level in a canine model of gastric motility disorders and the correlation between gastric emptying and plasma motilin level. METHODS: Ten healthy Mongrel dogs were divided into: experimental group of six dogs and control group of four dogs. A model of gastric motility disorders was established in the experimental group undergone truncal vagotomy combined with injection of glucagon. Gastric half-emptying time (GEt1/2) was monitored with single photon emission computerized tomography (SPECT), and the half-solid test meal was labeled with an isotope 99mTc sulfur colloid. Plasma motilin concentration was measured with radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1-1.2 times the intrinsic slow-wave frequency and a superimposed series of high frequency pulses (10-30 Hz) was performed for 45 min daily for a month in conscious dogs. RESULTS: After surgery, GEt1/2 in dogs undergone truncal vagotomy was increased significantly from 56.35 ± 2.99 min to 79.42 ± 1.91 min (P < 0.001), but surface gastric pacing markedly accelerated gastric emptying and significantly decreased GEt1/2 to 64.94 ± 1.75 min (P < 0.001) in animals undergone vagotomy. There was a significant increase of plasma level of motilin at the phase of IMCIII (interdigestive myoelectrical complex, IMCIII) in the dogs undergone bilateral truncal vagotomy (baseline vs vagotomy, 184.29 ± 9.81 pg/ml vs 242.09 ± 17.22 pg/ml; P < 0.01). But plasma motilin concentration (212.55 ± 11.20 pg/ml; P < 0.02) was decreased significantly after a long-term treatment with gastric pacing. Before gastric pacing, GEt1/2 and plasma motilin concentration of the dogs undergone vagotomy showed a positive correlation (r = 0.867, P < 0.01), but after a long-term gastric pacing, GEt1/2 and motilin level showed a negative correlation (r = -0.733, P < 0.04). CONCLUSION: Surface gastric pacing with optimal pacing parameters can improve gastric emptying parameters and significantly accelerate gastric emptying and can resume or alter motor function in a canine model of motility disorders. Gastric emptying is correlated well with plasma motilin level before and after pacing, which suggests that motilin can modulate the mechanism of gastric pacing by altering gastric motility. PMID:14760770
A Novel Type of Polyhedral Viruses Infecting Hyperthermophilic Archaea.
Liu, Ying; Ishino, Sonoko; Ishino, Yoshizumi; Pehau-Arnaudet, Gérard; Krupovic, Mart; Prangishvili, David
2017-07-01
Encapsidation of genetic material into polyhedral particles is one of the most common structural solutions employed by viruses infecting hosts in all three domains of life. Here, we describe a new virus of hyperthermophilic archaea, Sulfolobus polyhedral virus 1 (SPV1), which condenses its circular double-stranded DNA genome in a manner not previously observed for other known viruses. The genome complexed with virion proteins is wound up sinusoidally into a spherical coil which is surrounded by an envelope and further encased by an outer polyhedral capsid apparently composed of the 20-kDa virion protein. Lipids selectively acquired from the pool of host lipids are integral constituents of the virion. None of the major virion proteins of SPV1 show similarity to structural proteins of known viruses. However, minor structural proteins, which are predicted to mediate host recognition, are shared with other hyperthermophilic archaeal viruses infecting members of the order Sulfolobales The SPV1 genome consists of 20,222 bp and contains 45 open reading frames, only one-fifth of which could be functionally annotated. IMPORTANCE Viruses infecting hyperthermophilic archaea display a remarkable morphological diversity, often presenting architectural solutions not employed by known viruses of bacteria and eukaryotes. Here we present the isolation and characterization of Sulfolobus polyhedral virus 1, which condenses its genome into a unique spherical coil. Due to the original genomic and architectural features of SPV1, the virus should be considered a representative of a new viral family, "Portogloboviridae." Copyright © 2017 American Society for Microbiology.
Lin, Wenjing; Nie, Shuyu; Xiong, Di; Guo, Xindong; Wang, Jufang; Zhang, Lijuan
2014-01-01
Amphiphilic A2(BC)2 miktoarm star polymers [poly(ϵ-caprolactone)]2-[poly(2-(diethylamino)ethyl methacrylate)-b- poly(poly(ethylene glycol) methyl ether methacrylate)]2 [(PCL)2(PDEA-b-PPEGMA)2] were developed by a combination of ring opening polymerization (ROP) and continuous activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The critical micelle concentration (CMC) values were extremely low (0.0024 to 0.0043 mg/mL), depending on the architecture of the polymers. The self-assembled empty and doxorubicin (DOX)-loaded micelles were spherical in morphologies, and the average sizes were about 63 and 110 nm. The release of DOX at pH 5.0 was much faster than that at pH 6.5 and pH 7.4. Moreover, DOX-loaded micelles could effectively inhibit the growth of cancer cells HepG2 with IC50 of 2.0 μg/mL. Intracellular uptake demonstrated that DOX was delivered into the cells effectively after the cells were incubated with DOX-loaded micelles. Therefore, the pH-sensitive (PCL)2(PDEA-b-PPEGMA)2 micelles could be a prospective candidate as anticancer drug carrier for hydrophobic drugs with sustained release behavior.
Design on the wide band absorber with low density based on the particle distribution
NASA Astrophysics Data System (ADS)
Zheng, Dianliang; Liu, Ting; Liu, Longbin; Xu, Yonggang
2018-04-01
In order to widen the absorbing band, an equivalent gradient structure absorber was designed based on the particle distribution. Firstly, the electromagnetic parameter of the absorbent with uniform dispersion was tested using the vector network analyzer in 8-18 GHz. Three different equivalent materials of the spherical, square and hexagon empty shape were designed. The scattering parameters and the monostatic reflection loss (RL) of the periodic structural materials were simulated in the commercial software. Then the effective permittivity and the permeability was derived by the Nicolson-Ross-Weir algorithm and fitted by Maxwell-Garnett mixing rule. The results showed that the simulated reflectance and transmission parameters of equivalent composites with the different shapes were very close. The derived effective permittivity and permeability of the composite with different absorbent content was also close, and the average deviation was about 0.52 + j0.15 and 0.15 + j0.01 respectively. Finally, the wide band absorbing material was designed using the genetic algorithm. The optimized RL result showed that the absorbing composites with thickness 3 mm had an excellent absorbing property (RL <-10 dB) in 8-18 GHz, the equivalent absorber density could be decreased 30.7% compared with the uniform structure.
Imaging of Hsp70-positive tumors with cmHsp70.1 antibody-conjugated gold nanoparticles
Gehrmann, Mathias K; Kimm, Melanie A; Stangl, Stefan; Schmid, Thomas E; Noël, Peter B; Rummeny, Ernst J; Multhoff, Gabriele
2015-01-01
Real-time imaging of small tumors is still one of the challenges in cancer diagnosis, prognosis, and monitoring of clinical outcome. Targeting novel biomarkers that are selectively expressed on a large variety of different tumors but not normal cells has the potential to improve the imaging capacity of existing methods such as computed tomography. Herein, we present a novel technique using cmHsp70.1 monoclonal antibody-conjugated spherical gold nanoparticles for quantification of the targeted uptake of gold nanoparticles into membrane Hsp70-positive tumor cells. Upon binding, cmHsp70.1-conjugated gold nanoparticles but not nanoparticles coupled to an isotype-matched IgG1 antibody or empty nanoparticles are rapidly taken up by highly malignant Hsp70 membrane-positive mouse tumor cells. After 24 hours, the cmHsp70.1-conjugated gold nanoparticles are found to be enriched in the perinuclear region. Specificity for membrane Hsp70 was shown by using an Hsp70 knockout tumor cell system. Toxic side effects of the cmHsp70.1-conjugated nanoparticles are not observed at a concentration of 1–10 µg/mL. Experiments are ongoing to evaluate whether cmHsp70.1 antibody-conjugated gold nanoparticles are suitable for the detection of membrane-Hsp70-positive tumors in vivo. PMID:26392771
Interior view to the east of an empty computer room ...
Interior view to the east of an empty computer room - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Six Transmitter Building, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR
Research requirements to reduce empty weight of helicopters by use of advanced materials
NASA Technical Reports Server (NTRS)
Hoffstedt, D. J.
1976-01-01
Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12 percent at recurring costs competive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12 percent was shown to significantly reduce energy consumption in modern high-performance helicopters.
Adrian, T E; Greenberg, G R; Fitzpatrick, M L; Bloom, S R
1981-01-01
Bovine pancreatic polypeptide (PP) was infused intravenously in 5 healthy subjects on two separate occasions with mean doses of 1 and 2 pmol kg-1 min-1, respectively, which achieved plasma levels equal to and twice those observed after a normal mixed breakfast. The gastric emptying rate of a carbohydrate-rich breakfast 20 min after the start of each PP infusion was not significantly different from a control infusion of 0.15 M saline. PP is unlikely to be an important physiological modulator of gastric emptying rate in man.
Effects of peptide YY and neuropeptide Y on gastric emptying in man.
Allen, J M; Fitzpatrick, M L; Yeats, J C; Darcy, K; Adrian, T E; Bloom, S R
1984-01-01
Neuropeptide Y (NPY) and peptide YY (PYY) are two structurally related peptides. PYY has been identified within endocrine cells and NPY within nerves of the gastrointestinal tract. Infusion of PYY at a low dose at a nominal rate of 2 pmol/kg/min resulted in an increment of 59.2 +/- 7.1 pmol/1 in plasma concentration and a significant delay in gastric emptying of glucose. Infusion of NPY at the same rate produced similar plasma concentrations (52.5 +/- 1.1 pmol/1) and had no significant effect on the rate of gastric emptying.
Gastric emptying of cold beverages in humans: effect of transportable carbohydrates.
Shi, X; Bartoli, W; Horn, M; Murray, R
2000-12-01
Eight healthy subjects, aged 39.0 ¿ 2.4 years, consumed four 6% carbohydrate-electrolyte solutions containing either one (glucose or fructose) or two transportable carbohydrates in single (glucose + fructose) or bound (sucrose) forms. Solution osmolalities ranged from 250 to 434 mOsm/kg H2O. The test solutions were ingested at rest in the amount of 6 ml/kg of body weight at a temperature of 12 ¿C. Gastric emptying rate was measured by repeated aspirations via a nasogastric tube using the modified George double-sampling technique. The intragastric temperature was determined by a temperature probe attached to the nasogastric tube. There were no significant differences in gastric emptying rates and gastric volumes among the solutions. Intragastric temperature dropped from 36.5 ¿C to 23.3 ¿ 3 ¿C immediately after beverage ingestion but recovered to above 30 ¿C within 5 min. These data suggest that the gastric emptying rate of the specified beverages is not affected by the number and type of carbohydrates or by solution osmolalities within the tested range. Within 5 min after ingestion, cold beverages are warmed to above 30 C in the stomach. This infers that the effect of cold solution temperature on gastric emptying rate is likely to be small and transitory.
Concurrent hypercube system with improved message passing
NASA Technical Reports Server (NTRS)
Peterson, John C. (Inventor); Tuazon, Jesus O. (Inventor); Lieberman, Don (Inventor); Pniel, Moshe (Inventor)
1989-01-01
A network of microprocessors, or nodes, are interconnected in an n-dimensional cube having bidirectional communication links along the edges of the n-dimensional cube. Each node's processor network includes an I/O subprocessor dedicated to controlling communication of message packets along a bidirectional communication link with each end thereof terminating at an I/O controlled transceiver. Transmit data lines are directly connected from a local FIFO through each node's communication link transceiver. Status and control signals from the neighboring nodes are delivered over supervisory lines to inform the local node that the neighbor node's FIFO is empty and the bidirectional link between the two nodes is idle for data communication. A clocking line between neighbors, clocks a message into an empty FIFO at a neighbor's node and vica versa. Either neighbor may acquire control over the bidirectional communication link at any time, and thus each node has circuitry for checking whether or not the communication link is busy or idle, and whether or not the receive FIFO is empty. Likewise, each node can empty its own FIFO and in turn deliver a status signal to a neighboring node indicating that the local FIFO is empty. The system includes features of automatic message rerouting, block message transfer and automatic parity checking and generation.
Characterization and electron-energy-loss spectroscopy on NiV and NiMo superlattices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mahmood, S.H.
1986-01-01
NiV superlattices with periods (A) ranging from 15 to 80 A, and NiMo superlattices with from 14 to 110 A were studied using X-ray Diffraction (XRD), Electron Diffraction (ED), Energy-Dispersive X-Ray (EDX) microanalysis, and Electron Energy Loss Spectroscopy (EELS). Both of these systems have sharp superlattice-to-amorphous (S-A) transitions at about empty set = 17A. Superlattices with empty set around the S-A boundary were found to have large local variations in the in-plane grain sizes. Except for a few isolated regions, the chemical composition of the samples were found to be uniform. In samples prepared at Argonne National Laboratory (ANL), mostmore » places studied with EELS showed changes in the EELS spectrum with decreasing empty set. An observed growth in a plasmon peak at approx. 10ev in both NiV and NiMo as empty set decreased down to 19 A is attributed to excitation of interface plasmons. Consistent with this attribution, the peak height shrank in the amorphous samples. The width of this peak is consistent with the theory. The sift in this peak down to 9 ev with decreasing empty set in NiMo is not understood.« less
Gastric emptying of solids is markedly delayed when meals are fried.
Benini, L; Brighenti, F; Castellani, G; Brentegani, M T; Casiraghi, M C; Ruzzenente, O; Sembenini, C; Pellegrini, N; Caliari, S; Porrini, M
1994-11-01
We studied the effect of heat-treated fats on gastric emptying. Eight healthy asymptomatic volunteers (five males; age 28-41 years) ate on different days and in random order two meals identical in contents (pasta, tomato, beef, olive oil, carrots, orange, water; 870 kcal males, 700 kcal females; 47% of calories from carbohydrate, 36% from fat, 17% from protein), but cooked differently (fats fried or not). Ultrasound measurement of antral diameters was used to calculate basal antral section, its maximal dilation after the meal, the time necessary for total emptying, and the percent retention at hourly intervals. No difference was found in basal and maximal antral diameters after the two meals. On the contrary, total gastric emptying was significantly delayed after the fried meal [317.1 (24.12) vs 226.7 (18.4) min, mean (1 SEM); P < 0.002]. A significantly greater percentage of maximal antral distension was still present between 120 and 240 min after the fried meal. The glycemic response and hunger feeling were the same after the two meals, whereas there was a longer persistence of satiety and epigastric fullness after the fried meal. In conclusion, gastric emptying can be influenced not only by the meal content, but also by the way it is cooked.
Castilhos, A M; Francisco, C L; Branco, R H; Bonilha, S F M; Mercadante, M E Z; Meirelles, P R L; Pariz, C M; Jorge, A M
2018-05-04
Evaluation of the body chemical composition of beef cattle can only be measured postmortem and those data cannot be used in real production scenarios to adjust nutritional plans. The objective of this study was to develop multiple linear regression equations from in vivo measurements, such as ultrasound parameters [backfat thickness (uBFT, mm), rump fat thickness (uRF, mm), and ribeye area (uLMA, cm2)], shrunk body weight (SBW, kg), age (AG, d), hip height (HH, m), as well as from postmortem measurements (composition of the 9th to 11th rib section) to predict the empty body and carcass chemical composition for Nellore cattle. Thirty-three young bulls were used (339 ± 36.15 kg and 448 ± 17.78 d for initial weight and age, respectively). Empty body chemical composition (protein, fat, water, and ash in kg) was obtained by combining noncarcass and carcass components. Data were analyzed using the PROC REG procedure of SAS software. Mallows' Cp values were close to the ideal value of number of independent variables in the prediction equations plus one. Equations to predict chemical components of both empty body and carcass using in vivo measurements presented higher R2 values than those determined by postmortem measurements. Chemical composition of the empty body using in vivo measurements was predicted with R2 > 0.73. Equations to predict chemical composition of the carcass from in vivo measurements showed R2 lower (R2< 0.68) than observed for empty body, except for the water (R2 = 0.84). The independent variables SBW, uRF, and AG were sufficient to predict the fat, water, energy components of the empty body, whereas for estimation of protein content the uRF, HH, and SBW were satisfactory. For the calculation of the ash, the SBW variable in the equation was sufficient. Chemical compounds from components of the empty body of Nellore cattle can be calculated by the following equations: protein (kg) = 47.92 + 0.18 × SBW - 1.46 × uRF - 30.72 × HH (R2 = 0.94, RMSPE = 1.79); fat (kg) = 11.33 + 0.16 × SBW + 2.09 × uRF - 0.06 × AG (R2 = 0.74, RMSPE = 4.18); water (kg) = - 34.00 + 0.55 × SBW + 0.10 × AG - 2.34 × uRF (R2 = 0.96, RMSPE = 5.47). In conclusion, the coefficients of determination (for determining the chemical composition of the empty body) of the equations derived from in vivo measures were higher than those of the equations obtained from rib section measurements taken postmortem, and better than coefficients of determination of the equations to predict the chemical composition of the carcass.
Is oral immunotherapy the cure for food allergies?
Nowak-Wegrzyn, Anna; Fiocchi, Alessandro
2010-06-01
To review current evidence on food oral immunotherapy (OIT). Desensitized state, defined as the ingestion of a substantial amount of food in the home diet that protects from severe reactions to accidental exposures, can be achieved by approximately 50-75% of the children treated with OIT. The rate of permanent tolerance is unknown; the longer duration of OIT may result in permanent tolerance. Side effects are common both during the initial dose escalation and during home dosing. Most reactions are mild (oral pruritus, abdominal discomfort, and rashes) and decrease in frequency with the longer duration of OIT. Severe reactions treated with epinephrine have been reported during home dosing. Factors associated with increased risk of reactions to previously tolerated doses during home dosing include exercise, viral infection, dosing on empty stomach, menses, and asthma exacerbation. These preliminary data on OIT are encouraging. Additional studies must answer multiple questions including optimal dose, ideal duration of oral/sublingual immunotherapy, degree of protection, efficacy for different ages, severity and type of food allergy responsive to treatment and need for patient protection during home administration. Until these questions are answered in rigorous multicenter randomized and placebo-controlled trials, OIT remains an experimental approach with not sufficiently well established risk-to-benefit ratio.
Self and viral peptides can initiate lysis by autologous natural killer cells.
Mandelboim, O; Wilson, S B; Valés-Gómez, M; Reyburn, H T; Strominger, J L
1997-04-29
Natural killer (NK) cells are inhibited by specific allotypes of class I major histocompatibility complex ligands recognized by polymorphic inhibitory receptors (e.g., NKIR1 and NKIR2). NK1- and NK2-specific clones recognize two groups of HLA-C allotypes that are distinguished by a dimorphism at residue 80 in the alpha1 helix (alphaLys-80 and alphaAsn-80, respectively). "Empty" HLA-Cw7 expressed in peptide transporter-deficient cells and HLA-Cw7 loaded with several peptides each functioned as inhibitory ligands for NK2 lines and clones. However, loading of HLA-Cw7 with two other peptides derived from glutamic acid decarboxylase or coxsackie virus (each of which has been associated with autoimmune diabetes mellitus) abrogated this inhibitory recognition. Both peptides contained Lys at P8 of the epitope. Substitution of P8 with Ala or two other basic amino acids, His and Arg, resulted in peptides that were inhibitory, as were peptides with P8 Val, Glu, or Asn. The manner in which a Lys at P8 might affect recognition is discussed, together with a hypothesis for a novel mechanism by which an autoimmune disease might be initiated.
Kreijtz, Joost H C M; Wiersma, Lidewij C M; De Gruyter, Heidi L M; Vogelzang-van Trierum, Stella E; van Amerongen, Geert; Stittelaar, Koert J; Fouchier, Ron A M; Osterhaus, Albert D M E; Sutter, Gerd; Rimmelzwaan, Guus F
2015-03-01
Since the first reports in early 2013, >440 human cases of infection with avian influenza A(H7N9) have been reported including 122 fatalities. After the isolation of the first A(H7N9) viruses, the nucleotide sequences became publically available. Based on the coding sequence of the influenza virus A/Shanghai/2/2013 hemagglutinin gene, a codon-optimized gene was synthesized and cloned into a recombinant modified vaccinia virus Ankara (MVA). This MVA-H7-Sh2 viral vector was used to immunize ferrets and proved to be immunogenic, even after a single immunization. Subsequently, ferrets were challenged with influenza virus A/Anhui/1/2013 via the intratracheal route. Unprotected animals that were mock vaccinated or received empty vector developed interstitial pneumonia characterized by a marked alveolitis, accompanied by loss of appetite, weight loss, and heavy breathing. In contrast, animals vaccinated with MVA-H7-Sh2 were protected from severe disease. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Kiss, Gabriella; Holl, Jens M; Williams, Grant M; Alonas, Eric; Vanover, Daryll; Lifland, Aaron W; Gudheti, Manasa; Guerrero-Ferreira, Ricardo C; Nair, Vinod; Yi, Hong; Graham, Barney S; Santangelo, Philip J; Wright, Elizabeth R
2014-07-01
Respiratory syncytial virus (RSV), a member of the Paramyxoviridae family of nonsegmented, negative-sense, single-stranded RNA genome viruses, is a leading cause of lower respiratory tract infections in infants, young children, and the elderly or immunocompromised. There are many open questions regarding the processes that regulate human RSV (hRSV) assembly and budding. Here, using cryo-electron tomography, we identified virus particles that were spherical, filamentous, and asymmetric in structure, all within the same virus preparation. The three particle morphologies maintained a similar organization of the surface glycoproteins, matrix protein (M), M2-1, and the ribonucleoprotein (RNP). RNP filaments were traced in three dimensions (3D), and their total length was calculated. The measurements revealed the inclusion of multiple full-length genome copies per particle. RNP was associated with the membrane whenever the M layer was present. The amount of M coverage ranged from 24% to 86% in the different morphologies. Using fluorescence light microscopy (fLM), direct stochastic optical reconstruction microscopy (dSTORM), and a proximity ligation assay (PLA), we provide evidence illustrating that M2-1 is located between RNP and M in isolated viral particles. In addition, regular spacing of the M2-1 densities was resolved when hRSV viruses were imaged using Zernike phase contrast (ZPC) cryo-electron tomography. Our studies provide a more complete characterization of the hRSV virion structure and substantiation that M and M2-1 regulate virus organization. hRSV is a leading cause of lower respiratory tract infections in infants and young children as well as elderly or immunocompromised individuals. We used cryo-electron tomography and Zernike phase contrast cryo-electron tomography to visualize populations of purified hRSV in 3D. We observed the three distinct morphologies, spherical, filamentous, and asymmetric, which maintained comparable organizational profiles. Depending on the virus morphology examined, the amount of M ranged from 24% to 86%. We complemented the cryo-imaging studies with fluorescence microscopy, dSTORM, and a proximity ligation assay to provide additional evidence that M2-1 is incorporated into viral particles and is positioned between M and RNP. The results highlight the impact of M and M2-1 on the regulation of hRSV organization. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Detection of Buried Empty Lunar Lava Tubes Using GRAIL Gravity Data
NASA Astrophysics Data System (ADS)
Sood, R.; Chappaz, L.; Melosh, H. J.; Howell, K. C.; Blair, D. M.; Milbury, C.
2015-10-01
GRAIL gravity data is used to detect buried empty lunar lava tubes that are of interest as possible habitation sites safe from cosmic radiation and micrometeorite impacts. Regions in the maria with known skylights and sinuous rilles are investigated.
Imparting small vorticity to a Bianchi type-VIh empty spacetime
NASA Astrophysics Data System (ADS)
Batakis, Nikos A.
1981-04-01
We present and briefly discuss a Bianchi type-VIh empty spacetime. The field equations have been solved after being linearized with respect to a parameter which imparts vorticity to the model. The limit of zero vorticity is an already known solution.
Greenwood-Van Meerveld, Beverley; Tyler, Karl; Mohammadi, Ehsan; Pietra, Claudio
2012-01-01
Background Delayed gastric emptying is a common disorder with few effective therapeutic options. The goal of this study was to investigate whether ipamorelin, a synthetic peptidomimetic that acts on the ghrelin receptor, accelerates gastric emptying in a rodent model of gastroparesis induced by abdominal surgery and intestinal manipulation. Methods Fasted adult male rats were subjected to laparotomy and intestinal manipulation. Following the surgery rats received ipamorelin (0.014–0.14 µmol/kg) or vehicle control via intravenous administration. Gastric emptying was measured by the percent of total recovered radioactivity remaining in the stomach 15 minutes after intragastric gavage of 1.5 mL of 99mTc (technicium-99m) sulfur colloid in 0.5% methylcellulose. In a separate group of rats subjected to laparotomy and intestinal manipulation, the gastric fundus was isolated and tissue segments were suspended in an organ bath to assess the effect of ipamorelin (1 µM) on gastric smooth muscle contractility induced by acetylcholine and electrical field stimulation. Results Abdominal surgery caused a delay in gastric emptying with 78% ± 5% of the meal remaining in the stomach in vehicle controls. Ipamorelin (0.014 µmol/kg intravenous) resulted in a significant acceleration (P < 0.05 vs vehicle-treated rat) of gastric emptying with 52% ± 11% of the meal remaining in the stomach compared to nonsurgical control animals with 44% ± 6%. Following abdominal surgery and intestinal manipulation, isolated preparations of gastric smooth muscle exhibited a marked inhibition of acetylcholine and electrical field stimulation-induced contractile responses, which were reversed by ipamorelin and ghrelin. Conclusion These results suggest that ipamorelin accelerates gastric emptying in a rodent model of postoperative ileus through the stimulation of gastric contractility by activating a ghrelin receptor-mediated mechanism involving cholinergic excitatory neurons. PMID:27186127
Greenwood-Van Meerveld, Beverley; Tyler, Karl; Mohammadi, Ehsan; Pietra, Claudio
2012-01-01
Delayed gastric emptying is a common disorder with few effective therapeutic options. The goal of this study was to investigate whether ipamorelin, a synthetic peptidomimetic that acts on the ghrelin receptor, accelerates gastric emptying in a rodent model of gastroparesis induced by abdominal surgery and intestinal manipulation. Fasted adult male rats were subjected to laparotomy and intestinal manipulation. Following the surgery rats received ipamorelin (0.014-0.14 µmol/kg) or vehicle control via intravenous administration. Gastric emptying was measured by the percent of total recovered radioactivity remaining in the stomach 15 minutes after intragastric gavage of 1.5 mL of (99m)Tc (technicium-99m) sulfur colloid in 0.5% methylcellulose. In a separate group of rats subjected to laparotomy and intestinal manipulation, the gastric fundus was isolated and tissue segments were suspended in an organ bath to assess the effect of ipamorelin (1 µM) on gastric smooth muscle contractility induced by acetylcholine and electrical field stimulation. Abdominal surgery caused a delay in gastric emptying with 78% ± 5% of the meal remaining in the stomach in vehicle controls. Ipamorelin (0.014 µmol/kg intravenous) resulted in a significant acceleration (P < 0.05 vs vehicle-treated rat) of gastric emptying with 52% ± 11% of the meal remaining in the stomach compared to nonsurgical control animals with 44% ± 6%. Following abdominal surgery and intestinal manipulation, isolated preparations of gastric smooth muscle exhibited a marked inhibition of acetylcholine and electrical field stimulation-induced contractile responses, which were reversed by ipamorelin and ghrelin. These results suggest that ipamorelin accelerates gastric emptying in a rodent model of postoperative ileus through the stimulation of gastric contractility by activating a ghrelin receptor-mediated mechanism involving cholinergic excitatory neurons.
Padmanabha, H; Soto, E; Mosquera, M; Lord, C C; Lounibos, L P
2010-08-01
Understanding linkages between household behavior and Aedes aegypti (L.) larval ecology is essential for community-based dengue mitigation. Here we associate water storage behaviors with the rate of A. aegypti pupal production in three dengue-endemic Colombian cities with different mean temperatures. Qualitative, semi-structured interviews and pupal counts were conducted over a 7-15-day period in 235 households containing a water storage vessel infested with larvae. Emptying vessels more often than every 7 days strongly reduced pupal production in all three cities. Emptying every 7-15 days reduced production by a similar magnitude as emptying <7 days in Armenia (21.9 degrees C), has a threefold smaller reduction as compared to <7 days in Bucaramanga (23.9 degrees C), and did not reduce production in Barranquilla (29.0 degrees C). Lidding vessels reduced mosquito production and was most feasible in Barranquilla because of container structure. Vessel emptying strongly correlated with usage in Barranquilla, where many households stored water in case of interruptions in piped service rather than for regular use. In the cooler cities, >90% of households regularly used stored water for washing clothes, generating a weaker correlation between emptying and usage. Emptying was less frequent in the households surveyed in the dry season in all three cities. These results show that A. aegypti production and human behaviors are coupled in a temperature-dependent manner. In addition to biological effects on aquatic stages, climate change may impact A. aegypti production through human behavioral adaptations. Vector control programs should account for geographic variation in temperature and water usage behaviors in designing targeted interventions.
Evaluation of gastric emptying function in clinical practice.
Poitras, P; Picard, M; Déry, R; Giguère, A; Picard, D; Morais, J; Plourde, V; Boivin, M
1997-11-01
In this retrospective analysis, we compared different methods to evaluate gastric emptying function, aiming to improve the sensitivity and the clinical availability of our diagnostic testing. In the first study, we compared, in 72 patients clinically suspected of gastroparesis, the emptying of a meal containing two solid nutrients with different disintegration rates: 111In-labeled scrambled eggs and 99Tc-labeled liver cubes. Gastric emptying of 111In-labeled egg was delayed in 12 of our patients and the evacuation of the 99Tc-labeled liver was prolonged in 19 patients. The choice of the nutrient was not important for the identification of diabetic gastroparesis (43% vs 57%; NS), but it was determinant in the case of patients suspected of idiopathic gastroparesis (12% were positive with the egg and 25% with the liver; P < 0.05). In the second study, we compared two different diagnostic methods in 46 patients: a simple radiological detection of the gastric emptying of radiopaque pellets, and the scintigraphic emptying of a solid meal containing 99Tc-labeled liver cubes. Both tests correlated perfectly in 78% of our patients. In 15% of the population (six of these seven patients were diabetics suspected of gastroparesis) the scintigraphic method was normal, while the evacuation of radiopaque pellets was delayed. For clinical purposes, we therefore propose: (1) the scintigraphic method should use liver rather than egg as a radiolabeled tracer in order to improve the sensitivity of the test for detection of gastroparesis; and (2) the radiological detection of radiopaque markers is a reliable and convenient method for the detection of gastroparesis in clinical practice. It is possibly more sensitive than scintigraphy.
Gastric emptying and intragastric balloon in obese patients.
Bonazzi, P; Petrelli, M D; Lorenzini, I; Peruzzi, E; Nicolai, A; Galeazzi, R
2005-01-01
Intragastric balloons have been proposed to induce weight loss in obese subjects. The consequences of the balloon on gastric physiology remain poorly studied. We studied the influence of an intragastric balloon on gastric emptying in obese patients. 12 patients were included in the study, with BMI (mean +/- SD) of 38.51 +/- 4.32 kg/m2. The balloon was inserted under light anaesthesia and endoscopic control, inflated with 700 ml saline, and removed 6 months later. Body weight and gastric emptying (T1/2 and T lag) using 13C-octanoic acid breath test were monitored before balloon placement, during its permanence and 2 months after removal. Mean weight loss was: 6.2 +/- 2.3 kg after one month; 12.4 +/- 5.8 kg after 3 months; 14.4 +/- 6.6 kg after 6 months and 10.1 +/- 4.3 kg two months after BIB removal. Gastric emptying rates were significantly decreased in the first periods with balloon in place, and returned to pre-implantation values after balloon removal. T1/2 was: 87 +/- 32 min before BIB positioning, 181 +/- 91 min after 1 month, 145 +/- 99 min after 3 months, 104 +/- 50 min after 6 months and 90 +/- 43 min 2 months after removal. T lag was 36 +/- 18 min before BIB positioning, 102 +/- 82 min after 1 month, 77 +/- 53 min after 3 months, 59 +/- 28 min after 6 months and 40 +/- 21 min. 2 months after removal. BIB in obese patients seems to be a good help in following the hypo caloric diet, especially during the first three months when the gastric emptying is slower and the sense of repletion is higher. After this period gastric emptying starts to return to normal and the stomach adapts to BIB loosing efficacy in weight loss.
Borovicka, J; Schwizer, W; Guttmann, G; Hartmann, D; Kosinski, M; Wastiel, C; Bischof-Delaloye, A; Fried, M
2000-01-01
BACKGROUND AND AIMS—To investigate the importance of lipase on gastric functions, we studied the effects of orlistat, a potent and specific inhibitor of lipase, on postprandial gastric acidity and gastric emptying of fat. METHODS—Fourteen healthy volunteers participated in a double blind, placebo controlled, randomised study. In a two way cross over study with two test periods of five days, separated by at least 14 days, orlistat 120 mg three times daily or placebo was given with standardised daily meals. In previous experiments we found that this dose almost completely inhibited postprandial duodenal lipase activity. Subjects underwent 28 hour intragastric pH-metry on day 4, and a gastric emptying study with a mixed meal (800 kcal) labelled with 999mTc sulphur colloid (solids) and 111Inthiocyanate (fat) on day 5. Gastric pH data were analysed for three postprandial hours and the interdigestive periods. RESULTS—Orlistat inhibited almost completely (by 75%) lipase activity and accelerated gastric emptying of both the solid (by 52%) and fat (by 44%) phases of the mixed meal (p<0.03). Orlistat increased postprandial gastric acidity (from a median pH of 3.3 to 2.7; p<0.01). Postprandial cholecystokinin release was lower with orlistat (p<0.03). CONCLUSION—Lipase has an important role in the regulation of postprandial gastric acid secretion and fat emptying in humans. These effects might be explained by lipolysis induced release of cholecystokinin. Keywords: lipase; orlistat; gastric secretion; gastric emptying; pH-metry PMID:10807887
Habibi, Mohammadali; Samiei, Sanaz; Ambale Venkatesh, Bharath; Opdahl, Anders; Helle-Valle, Thomas M; Zareian, Mytra; Almeida, Andre L C; Choi, Eui-Young; Wu, Colin; Alonso, Alvaro; Heckbert, Susan R; Bluemke, David A; Lima, João A C
2016-08-01
Early detection of structural changes in left atrium (LA) before atrial fibrillation (AF) development could be helpful in identification of those at higher risk for AF. Using cardiac magnetic resonance imaging, we examined the association of LA volume and function, and incident AF in a multiethnic population free of clinical cardiovascular diseases. In a case-cohort study embedded in MESA (Multi-Ethnic Study of Atherosclerosis), baseline LA size and function assessed by cardiac magnetic resonance feature-tracking were compared between 197 participants with incident AF and 322 participants randomly selected from the whole MESA cohort. Participants were followed up for 8 years. Incident AF cases had a larger LA volume and decreased passive, active, and total LA emptying fractions and peak global LA longitudinal strain (peak LA strain) at baseline. In multivariable analysis, elevated LA maximum volume index (hazard ratio, 1.38 per SD; 95% confidence interval, 1.01-1.89) and decreased peak LA strain (hazard ratio, 0.68 per SD; 95% confidence interval, 0.48-0.96), and passive and total LA emptying fractions (hazard ratio for passive LA emptying fractions, 0.55 per SD; 95% confidence interval, 0.40-0.75 and hazard ratio for active LA emptying fractions, 0.70 per SD; 95% confidence interval, 0.52-0.95), but not active LA emptying fraction, were associated with incident AF. Elevated LA volumes and decreased passive and total LA emptying fractions were independently associated with incident AF in an asymptomatic multiethnic population. Including LA functional variables along with other risk factors of AF may help to better risk stratify individuals at risk of AF development. © 2016 American Heart Association, Inc.
Marciani, Luca; Faulks, Richard; Wickham, Martin S J; Bush, Debbie; Pick, Barbara; Wright, Jeff; Cox, Eleanor F; Fillery-Travis, Annette; Gowland, Penny A; Spiller, Robin C
2009-03-01
Fat is often included in common foods as an emulsion of dispersed oil droplets to enhance the organoleptic quality and stability. The intragastric acid stability of emulsified fat may impact on gastric emptying, satiety and plasma lipid absorption. The aim of the present study was to investigate whether, compared with an acid-unstable emulsion, an acid-stable fat emulsion would empty from the stomach more slowly, cause more rapid plasma lipid absorption and cause greater satiety. Eleven healthy male volunteers received on two separate occasions 500 ml of 15 % (w/w) [13C]palmitate-enriched olive oil-in-water emulsion meals which were either stable or unstable in the acid gastric environment. MRI was used to measure gastric emptying and the intragastric oil fraction of the meals. Blood sampling was used to measure plasma lipids and visual analogue scales were used to assess satiety. The acid-unstable fat emulsion broke and rapidly layered in the stomach. Gastric emptying of meal volume was slower for the acid-stable fat emulsion (P < 0.0001; two-way ANOVA). The rate of energy delivery of fat from the stomach to the duodenum was not different up to t = 110 min. The acid-stable emulsion induced increased fullness (P < 0.05), decreased hunger (P < 0.0002), decreased appetite (P < 0.0001) and increased the concentration of palmitic acid tracer in the chylomicron fraction (P < 0.04). This shows that it is possible to delay gastric emptying and increase satiety by stabilising the intragastric distribution of fat emulsions against the gastric acid environment. This could have implications for the design of novel foods.
Suess, Olaf; Schomaker, Martin; Cabraja, Mario; Danne, Marco; Kombos, Theodoros; Hanna, Michael
2017-01-01
Anterior cervical diskectomy and fusion (ACDF) is a well-established surgical treatment for radiculopathy and myelopathy. Previous studies showed that empty PEEK cages have lower radiographic fusion rates, but the clinical relevance remains unclear. This paper's aim is to provide high-quality evidence on the outcomes of ACDF with empty PEEK cages and on the relevance of radiographic fusion for clinical outcomes. This large prospective multicenter clinical trial performed single-level ACDF with empty PEEK cages on patients with cervical radiculopathy or myelopathy. The main clinical outcomes were VAS (0-10) for pain and NDI (0-100) for functioning. Radiographic fusion was evaluated by two investigators for three different aspects. The median (range) improvement of the VAS pain score was: 3 (1-6) at 6 months, 3 (2-8) at 12 months, and 4 (2-8) at 18 months. The median (range) improvement of the NDI score was: 12 (2-34) at 6 months, 18 (4-46) at 12 months, and 22 (2-44) at 18 months. Complete radiographic fusion was reached by 126 patients (43%) at 6 months, 214 patients (73%) at 12 months, and 241 patients (83%) at 18 months. Radiographic fusion was a highly significant ( p < 0.001) predictor of the improvement of VAS and NDI scores. This study provides strong evidence that ACDF is effective treatment, but the overall rate of radiographic fusion with empty PEEK cages is slow and insufficient. Lack of complete radiographic fusion leads to less improvement of pain and disability. We recommend against using empty uncoated pure PEEK cages in ACDF. ISRCTN42774128. Retrospectively registered 14 April 2009.
Krouk, Gabriel; Tillard, Pascal; Gojon, Alain
2006-01-01
The NRT2.1 gene of Arabidopsis thaliana encodes a major component of the root high-affinity \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} transport system (HATS) that plays a crucial role in \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} uptake by the plant. Although NRT2.1 was known to be induced by \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} and feedback repressed by reduced nitrogen (N) metabolites, NRT2.1 is surprisingly up-regulated when \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} concentration decreases to a low level (<0.5 mm) in media containing a high concentration of \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NH}}_{4}^{+}\\end{equation*}\\end{document} or Gln (≥1 mm). The NRT3.1 gene, encoding another key component of the HATS, displays the same response pattern. This revealed that both NRT2.1 and NRT3.1 are coordinately down-regulated by high external \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} availability through a mechanism independent from that involving N metabolites. We show here that repression of both genes by high \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} is specifically mediated by the NRT1.1 \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} transporter. This mechanism warrants that either NRT1.1 or NRT2.1 is active in taking up \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} in the presence of a reduced N source. Under low \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}/{\\mathrm{high\\hspace{.167em}NH}}_{4}^{+}\\end{equation*}\\end{document} provision, NRT1.1-mediated repression of NRT2.1/NRT3.1 is relieved, which allows reactivation of the HATS. Analysis of atnrt2.1 mutants showed that this constitutes a crucial adaptive response against \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NH}}_{4}^{+}\\end{equation*}\\end{document} toxicity because \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} taken up by the HATS in this situation prevents the detrimental effects of pure \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NH}}_{4}^{+}\\end{equation*}\\end{document} nutrition. It is thus hypothesized that NRT1.1-mediated regulation of NRT2.1/NRT3.1 is a mechanism aiming to satisfy a specific \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} demand of the plant in relation to the various specific roles that \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document} plays, in addition to being a N source. A new model is proposed for regulation of the HATS, involving both feedback repression by N metabolites and NRT1.1-mediated repression by high \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{NO}}_{3}^{-}\\end{equation*}\\end{document}. PMID:16998085
Mardassi, H; Athanassious, R; Mounir, S; Dea, S
1994-01-01
Cytolytic and noncytolytic strains of the porcine reproductive and respiratory syndrome virus (PRRSV) were isolated in primary cultures of porcine alveolar macrophages (PAM) from lung homogenates of stillborn fetuses or blood samples of dyspneic piglets collected from Quebec pig farms having experienced acute or chronic outbreaks of PRRS. Serological identification of the virus was confirmed by indirect immunofluorescence and indirect protein A-gold immunoelectron microscopy using reference antiserum prepared from experimentally-infected specific pathogen free (SPF) piglets and monoclonal antibodies (MoAbs) directed against the p15 nucleocapsid (N) protein of the reference ATCC-VR2332 isolate. Intracytoplasmic enveloped viral particles that tended to accumulate into cytoplasmic vesicles were observed in the infected PAM; no budding was demonstrated at the level of the cytoplasmic membrane. The extracellular virions appeared as pleomorphic but mostly spherical enveloped particles, 50-72 nm in diameter (averaged diameter of 50 particles was 58.3 nm), with an isometric core about 25-30 nm. Buoyant density of the virus in CsCL density gradients was estimated to 1.18-1.20 g/mL. No hemagglutinating activity was demonstrated. Analysis of semipurified virions of isolate IAF-exp91 by radioimmunoprecipitation (RIPA) and Western immunoblotting experiments, using reference rabbit and porcine hyperimmune sera, revealed four major viral proteins, a predominant 15 kD N protein and three other proteins with predicted M(r_ of 19, 26 and 42 kD. Progeny viral particles produced in PRRSV-infected PAM in the presence of tunicamycin lacked the 42 kD protein, thus confirming its N-glycosylated nature. Immunoprecipitation experiments using the anti-ATCC-VR2332 MoAbs confirmed the close antigenic relationships between Quebec and American reference isolates of PRRSV. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:8143254
Effect of the spatial autocorrelation of empty sites on the evolution of cooperation
NASA Astrophysics Data System (ADS)
Zhang, Hui; Wang, Li; Hou, Dongshuang
2016-02-01
An evolutionary game model is constructed to investigate the spatial autocorrelation of empty sites on the evolution of cooperation. Each individual is assumed to imitate the strategy of the one who scores the highest in its neighborhood including itself. Simulation results illustrate that the evolutionary dynamics based on the Prisoner's Dilemma game (PD) depends severely on the initial conditions, while the Snowdrift game (SD) is hardly affected by that. A high degree of autocorrelation of empty sites is beneficial for the evolution of cooperation in the PD, whereas it shows diversification effects depending on the parameter of temptation to defect in the SD. Moreover, for the repeated game with three strategies, 'always defect' (ALLD), 'tit-for-tat' (TFT), and 'always cooperate' (ALLC), simulations reveal that an amazing evolutionary diversity appears for varying of parameters of the temptation to defect and the probability of playing in the next round of the game. The spatial autocorrelation of empty sites can have profound effects on evolutionary dynamics (equilibrium and oscillation) and spatial distribution.
Irreversible reactions and diffusive escape: Stationary properties
Krapivsky, Paul L.; Ben-Naim, Eli
2015-05-01
We study three basic diffusion-controlled reaction processes—annihilation, coalescence, and aggregation. We examine the evolution starting with the most natural inhomogeneous initial configuration where a half-line is uniformly filled by particles, while the complementary half-line is empty. We show that the total number of particles that infiltrate the initially empty half-line is finite and has a stationary distribution. We determine the evolution of the average density from which we derive the average total number N of particles in the initially empty half-line; e.g. for annihilationmore » $$\\langle N\\rangle = \\frac{3}{16}+\\frac{1}{4\\π}$$ . For the coalescence process, we devise a procedure that in principle allows one to compute P(N), the probability to find exactly N particles in the initially empty half-line; we complete the calculations in the first non-trivial case (N = 1). As a by-product we derive the distance distribution between the two leading particles.« less
Jiang, Miaomiao; Yin, Zhiqin; Li, Sijiao; Chen, Xiaolin; Gu, Jiahuan
2018-06-01
The study aims to explore the effect of positive psychological intervention (fun activities combined with positive mental health education) on the well-being, 2-week illness prevalence, and salivary immunoglobulin A of empty nesters. Ninety-two empty nesters were divided into intervention ( n = 49) and control ( n = 43) groups. The empty nesters in the intervention group performed the intervention in addition to routine community activities. The intervention group scored significantly higher on well-being ( p< .05) compared with the control group after intervention. A week after intervention, salivary immunoglobulin A of the intervention group ( p< .05) was higher than that before intervention. Meanwhile, the difference in salivary immunoglobulin A in the control group before and after intervention was not statistically significant. 2-week illness prevalence in both groups did not exhibit a significant difference ( p> .05). Results indicate that positive psychological intervention can effectively increase the well-being and salivary immunoglobulin A of empty nesters and improve their physical and mental health.
Effect of Dai-kenchu-to on gastrointestinal motility and gastric emptying.
Kawasaki, Naruo; Nakada, Koji; Suzuki, Yutaka; Furukawa, Yoshiyuki; Hanyu, Nobuyoshi; Kashiwagi, Hideyuki
2009-06-01
The gastrointestinal symptoms accompanying dysfunction of the remnant stomach were seen after pylorus-preserving operation. Against such complications, Dai-kenchu-to (DKT) is used, but scientific evidences for efficacy are poor. The effect of DKT on gastrointestinal motility and gastric emptying after pylorus-preserving operation was investigated. Using beagle dogs, the experimental models mimicking the state after pylorus-preserving pancreaticoduodenectomy were prepared. We sutured strain gauge transducers to the stomach, duodenum and jejunum and inserted indwelling tubes into the stomach. About 4 weeks after operation, DKT 0.1g/kg was administered during the fasting or fed state. At the same time, the gastric emptying was evaluated by the acetoaminophene method. In the fasting state, administration of DKT enhanced the gastrointestinal motility and accelerated gastric emptying. In the postprandial state, no apparent effect on motility was seen. DKT enhances the gastrointestinal motility after pylorus-preserving pancreaticoduodenectomy in the fasting state. The effect of DKT may not be related to the continuity of the intramural nerve.
Emptying Dirac valleys in bismuth using high magnetic fields
Zhu, Zengwei; Wang, Jinhua; Zuo, Huakun; ...
2017-05-19
The Fermi surface of elemental bismuth consists of three small rotationally equivalent electron pockets, offering a valley degree of freedom to charge carriers. A relatively small magnetic field can confine electrons to their lowest Landau level. This is the quantum limit attained in other dilute metals upon application of sufficiently strong magnetic field. Here in this paper we report on the observation of another threshold magnetic field never encountered before in any other solid. Above this field, B empty, one or two valleys become totally empty. Drying up a Fermi sea by magnetic field in the Brillouin zone leads tomore » a manyfold enhancement in electric conductance. We trace the origin of the large drop in magnetoresistance across B empty to transfer of carriers between valleys with highly anisotropic mobilities. The non-interacting picture of electrons with field-dependent mobility explains most results but the Coulomb interaction may play a role in shaping the fine details.« less
Walter, Andreas; Franke-Whittle, Ingrid H; Wagner, Andreas O; Insam, Heribert
2015-01-01
The biomethane potential and structural changes of the methanogenic community in a solid-state anaerobic digestion process co-digesting cattle slurry and empty fruit bunches were investigated under mesophilic (37°C) and thermophilic (55°C) conditions. Phylogenetic microarrays revealed the presence of two hydrogenotrophic genera (Methanoculleus and Methanobrevibacter) and one acetoclastic genus (Methanosarcina). Methanosarcina numbers were found to increase in both mesophilic and thermophilic treatments of empty fruit bunches. Methanobrevibacter, which dominated in the cattle slurry, remained constant during anaerobic digestion (AD) at 37°C and decreased in numbers during digestion at 55°C. Numbers of Methanoculleus remained constant at 37°C and increased during the thermophilic digestion. Physicochemical data revealed non-critical concentrations for important monitoring parameters such as total ammonia nitrogen, free ammonia nitrogen and volatile fatty acids in all treatments after AD. The biomethane potential of empty fruit bunches was higher under thermophilic conditions than under mesophilic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.
Steingoetter, Andreas; Buetikofer, Simon; Curcic, Jelena; Menne, Dieter; Rehfeld, Jens F; Fried, Michael; Schwizer, Werner; Wooster, Tim J
2017-04-01
Background: Limited information exists on the relation between fat emulsion structure and its effect on the release of gastrointestinal hormones and feelings of satiation. Objective: We investigated the impact of fat emulsion droplet size, gravitational and acid stability, and redispersibility on gastrointestinal responses and sought to deduce the relative importance of the hormones ghrelin, cholecystokinin, glucagon-like peptide-1, and peptide YY (PYY) in controlling fat emptying and related satiation. Methods: Within a randomized, double-blind, 4-armed crossover study, an extensive data set was generated by MRI of gastric function, analysis of hormone profiles, and ratings of satiation in healthy participants [10 women and 7 men with a mean ± SD age of 25 ± 7 y and body mass index (in kg/m 2 ) of 22 ± 1] after intake of 4 different fat emulsions. Iterative Bayesian model averaging variable selection was used to investigate the influence of hormone profiles in controlling fat emulsion emptying and satiation. Results: The emulsion structure had a distinct effect on the gastric emptying (primary outcome), gastrointestinal hormone profiles, and ratings of satiation (secondary outcomes). Gravitational and acid stability were stronger modulators of fat emptying and hormone profiles than were emulsion droplet size or redispersibility. Cholecystokinin and PYY were most strongly affected by fat emulsion instability and droplet size. Although both hormones were relevant predictors of gastric emptying, only PYY was identified as a relevant predictor of satiation. Conclusions: This work indicates that evenly dispersed, stable, small-emulsion droplets within the stomach lead to prolonged gastric distension, longer ghrelin suppression, and accelerated fat sensing (cholecystokinin and PPY), triggering prolonged feelings of satiation. It suggests that the effects of emulsion instability and droplet size on energy consumption are best studied by assessing changes in gastric emptying and ratings of satiation rather than changes in venous hormone profiles. This trial was registered at clinicaltrials.gov as NCT01253005. © 2017 American Society for Nutrition.
Effect of Yifukang oral liquid on gastric emptying and intestinal peristalsis in mice
NASA Astrophysics Data System (ADS)
Sun, Jianhua; Li, Jun; Li, Xianyu; Hao, Shaojun; Guo, Junyi; Ma, Zhenzhen; Zhang, Zhengchen
2018-04-01
To observe the effect of Yifukang oral liquid on gastric emptying and intestinal peristalsis in mice. Methods: 60 mice were randomly divided into 5 groups. The suspension of Baohe Pill and the same volume of normal saline group were given once a day for 7 days. After the last administration for 30 minutes, 0.25 ml of 0.04% phenolic red solution was administered by stomach. After 20 minutes, the animals were killed, the stomach was removed, the gastric contents were cleaned, and the lotion 5ml was centrifuged. The absorbance of the supernatant was measured by TU-1901 ultraviolet spectrophotometer at the wavelength of 560nm. The residual rate of gastric phenolic red was calculated. Rate was used to evaluate gastric emptying velocity.60 mice were randomly divided into five groups: group 5, large, medium, small Yifukang oral liquid dosage group, pill suspension and the same volume normal saline. After 20 min after the last dose of carbon powder suspension, the mice were sacrificed, the abdominal cavity was cut open, the intestine of the ileocecum was cut off, the intestinal mesentery was separated, the total length of the small intestine (cm) was measured, and the distance (cm) in the small intestine was measured, and the end-of-carbon propulsion rate was calculated. Compared with the blank group, small dose of Yi Fu Kang group and Baohe Pill group could significantly promote the ability of gastric emptying in mice. Compared with the blank group, small dose group and rehabilitation benefits Baohewan group can significantly promote the gastric emptying ability of mice (P<0.01), high dose group had no obvious benefit rehabilitation ability to promote gastric emptying in mice. Yi Fu Kang oral liquid group could significantly increase the percentage of small intestine carbon powder(P<0.01), Large, medium-dose Yifukang oral liquid and Baofuwan group could significantly increase the percentage of small intestinal carbon in mice (P<0.05). Yi Fukang oral liquid has the effect of promoting gastric emptying and small intestinal peristalsis.
An Alternate, Egg-Free Radiolabeled Meal Formulation for Gastric-Emptying Scintigraphy.
Garrigue, Philippe; Bodin-Hullin, Aurore; Gonzalez, Sandra; Sala, Quentin; Guillet, Benjamin
2017-07-01
Tc-radiolabeled scrambled eggs (SEs) are most often used as the ingested solid phase for gastric-emptying scintigraphy, leading egg-reluctant patients to avoid the examination. We formulated and validated 2 egg-free alternate meals, in the absence of any commercialized formulation: chocolate mug cake (MC) and scrambled tofu (ST). Six healthy volunteers underwent gastric-emptying scintigraphy after ingesting Tc-radiolabeled MC, ST, or SE. Gastric retention indexes did not change significantly between formulations (% of overtime variation to SE: MC 7.75% ± 7.1%, ST 7.17% ± 5.8%; P = 0.6618, not statistically significant), suggesting MC and ST as interesting egg-free alternatives.
NASA Astrophysics Data System (ADS)
Martini, Luiz Cesar
2014-04-01
This article results from Introducing the Dimensional Continuous Space-Time Theory that was published in reference 1. The Dimensional Continuous Space-Time Theory shows a series of facts relative to matter, energy, space and concludes that empty space is inelastic, absolutely stationary, motionless, perpetual, without possibility of deformation neither can it be destroyed or created. A elementary cell of empty space or a certain amount of empty space can be occupied by any quantity of energy or matter without any alteration or deformation. As a consequence of these properties and being a integral part of the theory, the principles of Relativity Theory must be changed to become simple and intuitive.
NASA Astrophysics Data System (ADS)
Surawathanawises, Krissada
Separation and concentration of nanoscale species play an important role in various fields such as biotechnology, nanotechnology and environmental science. Inevitably, the separation efficiency strongly affects the quality of downstream detections or productions. Innovations in materials science that can separate bionanoparticles efficiently and do not require complex setups, reagents or external fields are highly demanded. This work focuses on developing new materials for the affinity separation of bio-nanoparticles such as viruses or macromolecules from a complex mixture, such as whole blood. To enhance the interaction between target nanoparticles and the capture bed, methods to produce porous matrices with a uniform pore size matching the dimension of targets are studied. Furthermore, regarding viral separation from whole blood, macroporous materials are further patterned into microarrays to allow multiscale separation. Considering the needs in resource-limited settings, these materials are integrated with microfluidic technologies to reduce the volume of samples and reagents, simplify operating processes, and enable the use of inexpensive and portable components. Beyond the application of viral separation as demonstrated in the work, the fundamental study of macroporous material formation and transport in these materials also shed light to the separation of many other nanospecies in multiscale materials. Specifically, two macroporous materials, based on template synthesis, are created in this work. The first type employs porous anodic aluminum oxide (AAO) films as the template to create hexagonal arrays of nanoposts. However, pore sizes and interpore distances (cell size) of ordered porous AAO films are limited by the conventional fabrication process. Moreover, the process usually yields defective pore morphologies and large pore and cell size distributions. To overcome these limitations, a patterning method using nanobead indentation on aluminum substrate prior to anodization is evaluated to control the growth of AAO. Together with controlled anodizing voltages and electrolytic concentrations, AAO pore and cell sizes are shown to be tunable and controllable with narrow size distributions within submicron range. A high degree of order of AAO pore arrangement is also demonstrated. In addition, overall anodization becomes more time-efficient and stable at high anodizing voltages. Secondly, a three-dimensional (3D) assembly of microbeads is used as a template to fabricate a spherical pore network with small interconnected openings. After depositing and drying a suspension containing both micro- and nanobeads, the microbeads assemble into a 3D close-packed structure while the nanobeads fill the interstitial space. When the nanobeads are melted and microbeads are removed, a spherical pore matrix then form with small interconnected openings. Such the opening size is in submicron range can be adjusted depending on the size of microbead. The advantages of the two macroporous materials are not only controllable and tunable pore size, but also high surface-to-volume ratio due to the nanoscale features. With a ratio on the order of ~1 microm-1, the porous materials provide a significantly large binding surface. Computational and experimental results reveal that porous materials with a pore size matching the nanoparticle size are suitable for their capture. Separation of human immunodeficiency virus (HIV) is used as a model and capture yields of ~99 % and ~80 % are achieved in the nanopost structure and spherical pore network, respectively, after treated with a functional chemistry. Hence, the properties of these two macroporous materials are suitable as a size-exclusion and affinity separation for viral particles. To further explore multiscale separation, i.e. capturing viruses from whole blood, micropatterned arrays of macroporous materials have been designed. In this design, a microscale gap allows the passage of microparticles such as blood cells, and the nanoscale pores promote permeation for affinity capture of bionanoparticles. Consequently, particles with a size difference of 3--4 orders of magnitude can be separated in a simple flow-through process. Computational analyses are employed to study the effect of micropattern shape and layout. A half-ring pattern is shown to reduce flow resistance and promote fluid permeation compared to a circular pattern. In the experiment, the micropatterned porous arrays yield around 4 times higher viral capture from whole blood compared with a micropatterned solid array. The micropatterned porous devices are capable of handling a large volume of fluid sample without clogging by cells. Therefore they can be used for nanoparticle concentration. Our study also indicates that the layout of micropatterns can be adjusted to improve the capture yield. For example, an increase in pattern radius, or a decrease in gap distance between each post and in width of half ring will enhance fluid permeation in the porous structure. When combined with downstream detection, these materials integrated into microfluidic platforms can be created as point-of-care diagnostics, as well as other applications for particle separation and analysis. (Abstract shortened by UMI.).
A Stiffness Switch in Human Immunodeficiency Virus
Kol, Nitzan; Shi, Yu; Tsvitov, Marianna; Barlam, David; Shneck, Roni Z.; Kay, Michael S.; Rousso, Itay
2007-01-01
After budding from the cell, human immunodeficiency virus (HIV) and other retrovirus particles undergo a maturation process that is required for their infectivity. During maturation, HIV particles undergo a significant internal morphological reorganization, changing from a roughly spherically symmetric immature particle with a thick protein shell to a mature particle with a thin protein shell and conical core. However, the physical principles underlying viral particle production, maturation, and entry into cells remain poorly understood. Here, using nanoindentation experiments conducted by an atomic force microscope (AFM), we report the mechanical measurements of HIV particles. We find that immature particles are more than 14-fold stiffer than mature particles and that this large difference is primarily mediated by the HIV envelope cytoplasmic tail domain. Finite element simulation shows that for immature virions the average Young's modulus drops more than eightfold when the cytoplasmic tail domain is deleted (930 vs. 115 MPa). We also find a striking correlation between the softening of viruses during maturation and their ability to enter cells, providing the first evidence, to our knowledge, for a prominent role for virus mechanical properties in the infection process. These results show that HIV regulates its mechanical properties at different stages of its life cycle (i.e., stiff during viral budding versus soft during entry) and that this regulation may be important for efficient infectivity. Our report of this maturation-induced “stiffness switch” in HIV establishes the groundwork for mechanistic studies of how retroviral particles can regulate their mechanical properties to affect biological function. PMID:17158573
USDA-ARS?s Scientific Manuscript database
Emerging evidence suggests that free glutamate may play a functional role in modulating gastroduodenal motor function. We hypothesized that supplementing monosodium glutamate (MSG) to partial enteral nutrition stimulates gastric emptying in preterm pigs. Ten-day-old preterm, parenterally fed pigs re...
14 CFR 223.24 - Transportation of empty mail bags.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Transportation of empty mail bags. 223.24 Section 223.24 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS FREE AND REDUCED-RATE TRANSPORTATION International Travel § 223.24...
14 CFR 223.24 - Transportation of empty mail bags.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Transportation of empty mail bags. 223.24 Section 223.24 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS FREE AND REDUCED-RATE TRANSPORTATION International Travel § 223.24...
Empty Signifiers, Education and Politics
ERIC Educational Resources Information Center
Szkudlarek, Tomasz
2007-01-01
The paper assumes that education is part of the process of discursive construction of society. The theoretical framework on which this argument is based includes Ernesto Laclau's theory of the "ontological impossibility and political necessity of society", and the role discourse and empty signifiers play in the establishment of political…
Yau, Adora M W; McLaughlin, John; Maughan, Ronald J; Gilmore, William; Evans, Gethin H
2017-03-10
This study aimed to examine gastric emptying rate and gastrointestinal hormone responses to fructose and glucose ingestion following 3 days of dietary fructose supplementation. Using the 13 C-breath test method, gastric emptying rates of equicaloric fructose and glucose solutions were measured in 10 healthy men with prior fructose supplementation (fructose supplement, FS; glucose supplement, GS) and without prior fructose supplementation (fructose control, FC; glucose control, GC). In addition, circulating concentrations of acylated ghrelin (GHR), glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin were determined, as well as leptin, lactate, and triglycerides. Increased dietary fructose ingestion resulted in accelerated gastric emptying rate of a fructose solution but not a glucose solution. No differences in GIP, GLP-1, or insulin incremental area under curve (iAUC) were found between control and supplement trials for either fructose or glucose ingestion. However, a trend for lower ghrelin iAUC was observed for FS compared to FC. In addition, a trend of lower GHR concentration was observed at 45 min for FS compared to FC and GHR concentration for GS was greater than GC at 10 min. The accelerated gastric emptying rate of fructose following short-term supplementation with fructose may be partially explained by subtle changes in delayed postprandial ghrelin suppression.
Yau, Adora M. W.; McLaughlin, John; Maughan, Ronald J.; Gilmore, William; Evans, Gethin H.
2017-01-01
This study aimed to examine gastric emptying rate and gastrointestinal hormone responses to fructose and glucose ingestion following 3 days of dietary fructose supplementation. Using the 13C-breath test method, gastric emptying rates of equicaloric fructose and glucose solutions were measured in 10 healthy men with prior fructose supplementation (fructose supplement, FS; glucose supplement, GS) and without prior fructose supplementation (fructose control, FC; glucose control, GC). In addition, circulating concentrations of acylated ghrelin (GHR), glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin were determined, as well as leptin, lactate, and triglycerides. Increased dietary fructose ingestion resulted in accelerated gastric emptying rate of a fructose solution but not a glucose solution. No differences in GIP, GLP-1, or insulin incremental area under curve (iAUC) were found between control and supplement trials for either fructose or glucose ingestion. However, a trend for lower ghrelin iAUC was observed for FS compared to FC. In addition, a trend of lower GHR concentration was observed at 45 min for FS compared to FC and GHR concentration for GS was greater than GC at 10 min. The accelerated gastric emptying rate of fructose following short-term supplementation with fructose may be partially explained by subtle changes in delayed postprandial ghrelin suppression. PMID:28287413
Atrial stretch delays gastric emptying of liquids in awake rats.
Palheta, R C; Silva, M T B; Barbosa, H L G; Pinheiro, A D N; Cardoso, K V V; Graça, J R V; Magalhães, P J C; Oliveira, R B; Santos, A A
2013-03-21
We previously reported that mechanical atrial stretch (AS) by balloon distention increased gastric tonus in anesthetized rats. The present study evaluated the effect of AS on the gastric emptying of a liquid test meal in awake rats and its underlying neural mechanisms. Anesthetized male rats received a balloon catheter into the right atrium and a gastrostomy cannula. The next day, mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), and cardiac output (CO) were continuously monitored. After the first 20min of monitoring (basal interval), the balloon was either distended or not (control) with 30, 50, or 70μl saline for 5min. Fifteen minutes later, the rats received the test meal (glucose solution with phenol red), and fractional gastric dye retention was determined 10, 20, or 30min later. Heart rate and CVP values were transiently increased by 50 or 70μl AS but not 30μl AS, whereas gastric emptying was slower after 30, 50, or 70μl AS than after sham distention. Subdiaphragmatic vagotomy or splanchnicotomy+celiac ganglionectomy and capsaicin, ondansetron, hexamethonium, L-NAME, and glibenclamide treatment prevented the AS-induced delay in gastric emptying, whereas atropine and guanethidine treatment failed to prevent it. Atrial stretch inhibited the gastric emptying of liquid via non-adrenergic and non-cholinergic pathways that activate nitric oxide-K(+)ATP channels. Copyright © 2013 Elsevier Inc. All rights reserved.
Mazzanti, Morena; Alessandrini, Federica; Tagliabracci, Adriano; Wells, Jeffrey D; Campobasso, Carlo P
2010-02-25
Puparial cases are common remnants of necrophagous flies in crime investigations. They usually represent the longest developmental time and, therefore, they can be very useful for the estimation of the post-mortem interval (PMI). However, before any PMI estimate, it is crucial to identify the species of fly eclosed from each puparium associated with the corpse. Morphological characteristics of the puparium are often distinctive enough to permit a species identification. But, even an accurate morphological analysis of empty puparia cannot discriminate among different species of closely related flies. Furthermore, morphological identification may be impossible if the fly puparia are poorly preserved or in fragments. This study explores the applicability of biomolecular techniques on empty puparia and their fragments for identification purposes. A total of 63 empty puparia of necrophagous Diptera resulting from forensic casework were examined. Samples were divided into three groups according to size, type and time of eclosion in order to verify whether the physical characteristics and puparia weathering can influence the amount of DNA extraction. The results suggest that a reliable genetic identification of forensically important flies may also be performed from empty puparia and/or their fragments. However, DNA degradation can deeply compromise the genetic analysis since the older the fly puparia, the smaller are the amplified fragments. 2009 Elsevier Ireland Ltd. All rights reserved.
Xu, J; Chen, J D Z
2008-03-01
The aim of this study was to investigate the effects of short-pulse intestinal electrical stimulation (IES) on duodenal distention-induced delayed gastric emptying and vomiting in dogs and its possible mechanisms. The study was performed in 12 dogs with jejunal electrodes and a duodenal cannula in three separate experiments to investigate the effects of IES on duodenal distension (DD)-induced delayed gastric emptying and discomfort signs, vagal efferent activity, and jejunal tone. We found that: (i) IES significantly accelerated gastric emptying of liquid delayed by distension (18.05 +/- 4.06%vs. 7.18 +/- 1.99%, P = 0.036 at 60 min). (ii) IES significantly reduced vomiting and discomfort/pain induced by distension. The average signs score was 15.33 +/- 1.37 during distension which decreased to 6.50 +/- 0.91 (P = 0.0002) with IES. (iii) IES did not change vagal afferent activity, which was assessed by the spectral analysis of the heart rate variability. (iv) IES decreased jejunal tone. In conclusion, IES with parameters commonly used in gastric electrical stimulation for nausea and vomiting associated with gastroparesis improves DD-induced delayed gastric emptying and prevents DD-induced vomiting and discomfort signs. Further studies are warranted to investigate the therapeutic potential of IES for gastrointestinal symptoms associated with disturbances in motility and sensory function in small intestine.
Ursodeoxycholic acid improves gastrointestinal motility defects in gallstone patients
Colecchia, A; Mazzella, G; Sandri, L; Azzaroli, F; Magliuolo, M; Simoni, P; Bacchi-Reggiani, ML; Roda, E; Festi, D
2006-01-01
AIM: To simultaneously evaluate the presence of defects in gallbladder and gastric emptying, as well as in intestinal transit in gallstone patients (GS) and the effect of chronic ursodeoxycholic acid (UDCA) administration on these parameters and on serum bile acids and clinical outcome in GS and controls (CTR). METHODS: After a standard liquid test meal, gallbla-dder and gastric emptying (by ultrasound), oroileal transit time (OITT) (by an immunoenzymatic technique) and serum bile acids (by HPLC) were evaluated before and after 3 mo of UDCA (12 mg/kg bw/d) or placebo administration in 10 symptomatic GS and 10 matched healthy CTR. RESULTS: OITT was longer in GS than in CTR (P < 0.0001); UDCA significantly reduced OITT in GS (P < 0.0001), but not in CTR. GS had longer gastric half-emptying time (t1/2) than CTR (P < 0.0044) at baseline; after UDCA, t1/2 significantly decreased (P < 0.006) in GS but not in CTR. Placebo administration had no effect on gastric emptying and intestinal transit in both GS and CTR. CONCLUSION: The gallstone patient has simultaneous multiple impairments of gallbladder and gastric emptying, as well as of intestinal transit. UDCA administration restores these defects in GS, without any effect in CTR. These results confirm the pathogenetic role of gastrointestinal motility in gallstone disease and suggest an additional mechanism of action for UDCA in reducing bile cholesterol supersaturation. PMID:16981264
[Electrogastrography and gastric emptying in non organic dyspepsia].
López Gastón, A R; López De Luise, G A; Sarmiento, A
1996-01-01
Electrogastrography allows to determinate the dominant frequency of gastric E.C.A. (electrical control activity). The aim was to investigate the gastric E.C.A. in a population of patients suffering from non-organic dispepsia (N.O.D.). Eighteen controls (9 males, 9 females, mean age 46.4 years old, SEM 3.72, range 24-72) and 52 dyspeptic patients (18 males, 34 females, mean age 54.19 years old, SEM 2.38, range 17-86) were studied. Two skin surface electrodes Ag-2ClAg were placed on epigastric area following a probabilistic antral axe. Reference electrode was placed on the right quadrant skin. In 5 patients, recordings with needle and cutaneous electrode were compared. Analogic waves were filtered, digitalized and processed. Signals were analyzed using F.F.T. (Fast Fourier Transformated) Only the predominant frequency in each block was considered, and percentage of total abnormalities on total recording time lesser than 2 c.p.m. or more than 4 c.p.m. was accepted. Recording were taken in fast time during 30 minutes, and 30 minutes after a meal containing 230 Cal. Running spectral analysis with F.F.T. In 43 non-selected patients the gastric emptying time of a mixed meal marked with 99 Tc in the solid phase was studied. 60.45% showed delayed gastric emptying. Mean of fast E.C.A. was 2.99 c.p.m. in controls, Vs 3.34 c.p.m. in dispeptic patients (p > 0.001). In the post-prandial period, mean of E.C.A. was 3.53 c.p.m. in N.O.D., and these differences were not significatives ("t", NS). 22% of controls showed isolated periods of tachygastria, but never more than 8% of the total recording time. It was seen seven six and forty five percent of arrhythmias were observed (71.15% tachygastria, 4.76% bradygastria, and 19.23% mixed) during post prandial recording in N.O.D. 48% of tachygastrias were between the range 30-60% of the time recording. Ninety six and one percent of patients with abnormal gastric emptying had gastric arrhythmias (0.05 > p > 0.02) Vs 50% in patients with normal gastric emptying. Needle recording increased about 200-300% the signal power. It would be the better choice in cases of hairy abdominal skin. a) More than 76% of patients with N.O.D. had abnormal recording of E.C.A. beyond these observed in controls; b) tachygastria was the more frequent abnormality observed; c) the more severe clinical cases were associated with bradygastria; d) No association between symptoms and abnormal gastric emptying was found; e) E.G.G. abnormalities were seen in 96% of patients with abnormal gastric emptying, Vs 50% in normal gastric emptying; f) Needle electrodes let a better recording of E.G.G. signal; g) No association was found between abnormalities in gastric emptying and/or E.G.G., and clinical subtypes of Dyspepsia.
Fang, Hui; Tang, Hailin; Li, Peng; Xiong, Li; Hu, Gongpai; Li, Li; Yu, Yonghong; Zhao, Bowen
2017-03-01
The objective of this study was to assess left atrial (LA) function with two-dimensional speckle tracking echocardiography (2DSTE) in addition to standard echocardiographic assessments in patients with hypertrophic obstructive cardiomyopathy (HOCM) before and 1 year after septal ablation (SA). The study included 31 patients with HOCM, who underwent SA. Each patient with HOCM underwent a complete two-dimensional transthoracic echocardiography before and 1 year after the SA. The measurements included basal septal thickness, left ventricular outflow trace (LVOT) gradient, mitral regurgitation (MR) grade, LA dimensions, left ventricular (LV) ejection fraction, and tissue Doppler parameters of lateral mitral annular e' and septal mitral annular e'. The LA wall was tracked on a frame-by-frame basis using 2DSTE, and LA volume waveforms were generated. The maximum LA volume (LAV max ), minimal LA volume (LAV min ), and the LA volume before atrial contraction (LAV pre-a ) were measured. The LA reservoir function was calculated as the expansion index and diastolic emptying index. The LA conduit function was calculated as the passive emptying percentage of total emptying (PE) and the passive emptying index (PEI). The LA booster function was calculated as the active emptying percentage of total emptying (AE) and the active emptying index (AEI). The LVOT gradient, end-diastolic septal base thickness, the grade of MR, and LA end-diastolic size were significantly decreased in patients with HOCM before and 1 year after the SA (All P<.05). The lateral mitral annular e' was significantly increased (P<.05), and the E/lateral e' ratio was significantly decreased (P<.05), whereas septal mitral annular e' was significantly decreased (P<.05), and the E/septal e' ratio was significantly increased (P<.05). LAVI max , LAVI min , and LAVI pre-a were significantly decreased 1 year after the SA (All P<.05). The expansion and diastolic emptying indices were significantly increased (All P<.05) at 1 year after the SA. PE and PEI were significantly increased (All P<.05). The AE and AEI were significantly decreased (All P<.05). LAVI max , LAVI min , and LAVI pre-a of the responders group were significantly lower than those of the nonresponders group (All P<.05). The expansion and diastolic emptying indices of the responders group were significantly higher than those of the nonresponders group (All P<.05). The PE and PEI of the responders were significantly higher than those of the nonresponders group (All P<.05). The AE and AEI of the responders were significantly lower than those of the nonresponders group (All P<.05). We found an improvement in the LA reservoir and conduit function but a reduction in LA booster pump function 1 year after the SA in the responders. © 2017, Wiley Periodicals, Inc.
Percent Stomach Emptiness in Fish Collections: Sources of Variation and Study Design Implications
We summarized fish stomach content data from 369,000 fish from 402 species in 1,096 collections made between 1925 and 2009 and report on the percentage of individuals with empty stomachs (PES). The mean PES among all species, locations, habitats, dates, and collection methods was...
Emptying the Nest: Launching Your Young Adult toward Success and Self-Reliance
ERIC Educational Resources Information Center
Sachs, Brad E.
2010-01-01
In today's rapidly changing world and challenging economy, young adults increasingly find themselves at a crossroads between financial and emotional dependence and autonomy. Drawing on Dr. Sachs' extensive clinical experience and his illuminating discussion of the latest psychological research, "Emptying the Nest" will support parents in their…
24 CFR 3280.612 - Tests and inspection.
Code of Federal Regulations, 2010 CFR
2010-04-01
... leaks. Then the system shall be unplugged and emptied. The waste piping above the level of the water... water and checking for leaks and retarded flow while they are being emptied. (d) Shower compartments... and inspection. (a) Water system. All water piping in the water distribution system shall be subjected...
40 CFR 261.7 - Residues of hazardous waste in empty containers.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Residues of hazardous waste in empty containers. 261.7 Section 261.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.7 Residues of hazardous...
DOT National Transportation Integrated Search
2007-09-01
A Virtual Container Yard (VCY) is a mean of developing a shared resource information system to match empty equipment needs through the adoption of next generation internet and new technology information platforms. The project examines the feasibility...
ERIC Educational Resources Information Center
Coryell, Susan M.
1994-01-01
Presents an approach to discussion of Shakespearean sonnets, in which a group of students makes a presentation to the class and two empty chairs. Notes that, after the presentation, members of the larger group can take one of the empty seats and offer evidence or questions to the "experts," producing a lively and focused group…
Further evidence for the EPNT assumption
NASA Technical Reports Server (NTRS)
Greenberger, Daniel M.; Bernstein, Herbert J.; Horne, Michael; Zeilinger, Anton
1994-01-01
We recently proved a theorem extending the Greenberger-Horne-Zeilinger (GHZ) Theorem from multi-particle systems to two-particle systems. This proof depended upon an auxiliary assumption, the EPNT assumption (Emptiness of Paths Not Taken). According to this assumption, if there exists an Einstein-Rosen-Podolsky (EPR) element of reality that determines that a path is empty, then there can be no entity associated with the wave that travels this path (pilot-waves, empty waves, etc.) and reports information to the amplitude, when the paths recombine. We produce some further evidence in support of this assumption, which is certainly true in quantum theory. The alternative is that such a pilot-wave theory would have to violate EPR locality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1996-07-01
The module reviews two sets of regulatory requirements for containers: requirements that pertain to the management of hazardous waste containers and regulations governing residues of hazardous waste in empty containers. It defines `container` and `empty container` and provides examples and citations for each. It provides an overview of the requirements for the design and operation of hazardous waste containers. It explains the difference between the container standards set out in part 264 and part 265. It states the requirements for rendering a hazardous waste container `RCRA empty`. It explains when container rinsate must be managed as a hazardous waste.
40 CFR 280.70 - Temporary closure.
Code of Federal Regulations, 2013 CFR
2013-07-01
... (UST) Out-of-Service UST Systems and Closure § 280.70 Temporary closure. (a) When an UST system is... the UST system is empty. The UST system is empty when all materials have been removed using commonly... the total capacity of the UST system, remain in the system. (b) When an UST system is temporarily...
40 CFR 280.70 - Temporary closure.
Code of Federal Regulations, 2011 CFR
2011-07-01
... (UST) Out-of-Service UST Systems and Closure § 280.70 Temporary closure. (a) When an UST system is... the UST system is empty. The UST system is empty when all materials have been removed using commonly... the total capacity of the UST system, remain in the system. (b) When an UST system is temporarily...
40 CFR 280.70 - Temporary closure.
Code of Federal Regulations, 2010 CFR
2010-07-01
... (UST) Out-of-Service UST Systems and Closure § 280.70 Temporary closure. (a) When an UST system is... the UST system is empty. The UST system is empty when all materials have been removed using commonly... the total capacity of the UST system, remain in the system. (b) When an UST system is temporarily...
40 CFR 280.70 - Temporary closure.
Code of Federal Regulations, 2014 CFR
2014-07-01
... (UST) Out-of-Service UST Systems and Closure § 280.70 Temporary closure. (a) When an UST system is... the UST system is empty. The UST system is empty when all materials have been removed using commonly... the total capacity of the UST system, remain in the system. (b) When an UST system is temporarily...
40 CFR 280.70 - Temporary closure.
Code of Federal Regulations, 2012 CFR
2012-07-01
... (UST) Out-of-Service UST Systems and Closure § 280.70 Temporary closure. (a) When an UST system is... the UST system is empty. The UST system is empty when all materials have been removed using commonly... the total capacity of the UST system, remain in the system. (b) When an UST system is temporarily...
ERIC Educational Resources Information Center
Bliss, S. A.
2017-01-01
Drawing from the conceptual framework of "shunyata" (emptiness), this article elucidates mindfulness practices and detachment from identity labels, offering a turn toward educators' and students' well-being. With a call for educators to consider a personal mindfulness practice prior to implementing techniques with children, the author…
USDA-ARS?s Scientific Manuscript database
A standardized 4-hour adult-based gastric emptying scintigraphy (GES) protocol is increasingly being used in children to evaluate for gastroparesis. We sought to determine the effect of age, anthropometrics, and study duration on GES results using this protocol in children. Retrospective review of c...
DOT National Transportation Integrated Search
2017-08-01
In 2015, the Ports of Los Angeles and Long Beach moved 15.3 million twenty-foot Equivalent Units (TEU). There is a significant body of work on moving loaded containers efficiently, however there has been little research on the movement of empty conta...
ERIC Educational Resources Information Center
Raja, Michele; Azzoni, Antonella; Giammarco, Vincenzo
1998-01-01
Describes an Italian patient with Asperger disorders, Neurogenic Diabetes Insipidus, and Primary Empty Sella. His response to vasopressin treatment suggested a concomitant presence of primary polydipsia. Implications of the observed concurrence of these rare disorders are discussed in relation to diagnosis and pathogenesis. (Author/CR)
40 CFR 63.120 - Storage vessel provisions-procedures to determine compliance.
Code of Federal Regulations, 2012 CFR
2012-07-01
... Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and...) each time the storage vessel is emptied and degassed, and at least once every 10 years after the... (if any) each time the storage vessel is emptied and degassed and at least once every 5 years after...
40 CFR 63.120 - Storage vessel provisions-procedures to determine compliance.
Code of Federal Regulations, 2014 CFR
2014-07-01
... Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and...) each time the storage vessel is emptied and degassed, and at least once every 10 years after the... (if any) each time the storage vessel is emptied and degassed and at least once every 5 years after...
40 CFR 63.120 - Storage vessel provisions-procedures to determine compliance.
Code of Federal Regulations, 2013 CFR
2013-07-01
... Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and...) each time the storage vessel is emptied and degassed, and at least once every 10 years after the... (if any) each time the storage vessel is emptied and degassed and at least once every 5 years after...
40 CFR 63.120 - Storage vessel provisions-procedures to determine compliance.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater... time the storage vessel is emptied and degassed, and at least once every 10 years after the compliance... (if any) each time the storage vessel is emptied and degassed and at least once every 5 years after...
19. EMPTY SEDIMENTATION TANKS. TOP LAYER OF WATER FLOWS OVER ...
19. EMPTY SEDIMENTATION TANKS. TOP LAYER OF WATER FLOWS OVER TRIANGULATED CHANNELS AND OUT THE RAISED DUCTS TO FILTRATION PLANT. MOVEABLE BOARDS ON BOTTOM ASSIST IN REMOVING SLUDGE. VIEW LOOKING NORTHEAST. FILTER CONTROL BUILDING AT REAR. - F. E. Weymouth Filtration Plant, 700 North Moreno Avenue, La Verne, Los Angeles County, CA
7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5FOOTDIAMETER RIVETED STEEL ...
7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5-FOOT-DIAMETER RIVETED STEEL SOAP KETTLE, WITH STEAM COILS; VIEW DOWN FROM KETTLE TOP, FIFTH FLOOR, EAST BAY, THIRD KETTLE FROM SOUTH - Colgate & Company Jersey City Plant, Building No. B-13, 48-50 Grand Street, Jersey City, Hudson County, NJ
Spirit and Its Now-Empty Mother Ship
NASA Technical Reports Server (NTRS)
2004-01-01
This overhead polar image was captured after the Mars Exploration Rover Spirit took a few baby rolls away from the spacecraft that bore it millions of miles to Mars. The empty lander, now named the Columbia Memorial Station, can be seen to the right of the rover. This image was taken by Spirit's navigation camera.
Gastric emptying and postprandial glucose excursions in adolescents with type 1 diabetes
USDA-ARS?s Scientific Manuscript database
Because amylin is co-secreted with insulin from beta cells, patients with type 1 diabetes (T1DM) are deficient in both insulin and amylin. Amylin delays gastric emptying and suppresses glucagon in the postprandial period. Hence, we hypothesized that children with complication-naive T1DM have acceler...
40 CFR 63.695 - Inspection and monitoring requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... least once every calendar year after initial fill, and (B) Visually inspect the internal floating roof...) each time the tank is emptied and degassed and at least every 10 years. Prior to each inspection, the... emptied and degassed and at least every 5 years. Prior to each inspection, the owner or operator shall...
Predictors of response to a behavioral treatment in patients with chronic gastric motility disorders
NASA Technical Reports Server (NTRS)
Rashed, Hani; Cutts, Teresa; Abell, Thomas; Cowings, Patricia; Toscano, William; El-Gammal, Ahmed; Adl, Dima
2002-01-01
Chronic gastric motility disorders have proven intractable to most traditional therapies. Twenty-six patients with chronic nausea and vomiting were treated with a behavioral technique, autonomic training (AT) with directed imagery (verbal instructions), to help facilitate physiological control. After treatment, gastrointestinal symptoms decreased by >30% in 58% of the treated patients. We compared those improved patients to the 43% who did not improve significantly. No significant differences existed in baseline symptoms and autonomic measures between both groups. However, baseline measures of gastric emptying and autonomic function predicted treatment outcome. Patients who improved manifested mild to moderate delay in baseline gastric emptying measures. The percent of liquid gastric emptying at 60 mins and the sympathetic adrenergic measure of percent of change in the foot cutaneous blood flow in response to cold stress test predicted improvement in AT outcome, with clinical diagnostic values of 77% and 71%, respectively. We conclude that AT treatment can be efficacious in some patients with impaired gastric emptying and adrenergic dysfunction. More work is warranted to compare biofeedback therapy with gastric motility patients and controls in population-based studies.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Arianie, Lucy, E-mail: lucy205@yahoo.com; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id; Nurrachman, Zeily, E-mail: deana@chem.itb.ac.id
The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, {sup 1}H-NMR, {sup 13}C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showedmore » that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.« less
Li, Lai-Fu; Lu, Yan-Yu; Xiong, Wei; Liu, Juan-Ying; Chen, Qiang
2008-10-24
The central or systemic administration of 3-carboxy-4-octyl-2-methylenebutyrolactone (C75), a synthetic inhibitor of fatty acid synthase (FAS), causes anorexia and profound weight loss in rodents. The amount of food intake and gastrointestinal mobility are closely related. In this study, an attempt has been made to investigate the effects and mechanisms of C75 on gastric emptying and gastrointestinal transit after intracerebroventricular (i.c.v.) injection in mice. Our data showed that C75 (1, 5, 10 microg/mouse) dose-dependently delayed gastric emptying and gastrointestinal transit in fasted mice. 10 microg C75 delayed gastric emptying by about 21.4% and reduced gastrointestinal transit by about 31.0% compared with vehicle control group. Administration (i.c.v.) of 5-(tetradecyloxy)-2-furoic acid (TOFA, an acetyl-CoA carboxylase (ACC) inhibitor) or ghrelin attenuated the delayed gastrointestinal mobility effect induced by 10 microg C75. Taken together, C75 is able to decrease gastrointestinal mobility and it seems possible that malonyl-CoA and ghrelin might play an intermediary role in these processes.
Setchell, Kenneth D R; Nardi, Elisabetta; Battezzati, Pier-Maria; Asciutti, Stefania; Castellani, Danilo; Perriello, Gabriele; Clerici, Carlo
2013-11-01
To determine the effect of soy germ pasta enriched in biologically active isoflavone aglycons on gastric emptying in type 2 diabetic patients with gastroparesis. This randomized double-blind, placebo-controlled study compared soy germ pasta with conventional pasta for effects on gastric emptying. Patients (n = 10) with delayed gastric emptying consumed one serving per day of each pasta for 8 weeks, with a 4-week washout. Gastric emptying time (t1/2) was measured using the [(13)C]octanoic acid breath test at baseline and after each period, and blood glucose and insulin concentrations were determined after oral glucose load. Soy germ pasta significantly accelerated the t1/2 in these patients (161.2 ± 17.5 min at baseline vs. 112.6 ± 11.2 min after treatment, P = 0.009). Such change differed significantly (P = 0.009) from that for conventional pasta (153.6 ± 24.2 vs. 156.2 ± 27.4 min), without affecting glucose or insulin concentrations. These findings suggest that soy germ pasta may offer a simple dietary approach to managing diabetic gastropathy.
NASA Astrophysics Data System (ADS)
Arianie, Lucy; Wahyuningrum, Deana; Nurrachman, Zeily; Natalia, Dessy
2014-03-01
The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, 1H-NMR, 13C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showed that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.
Saifur, Rahman G M; Hassan, Ahmad Abu; Dieng, Hamady; Salmah, Md Rawi Che; Saad, Ahmad Ramli; Satho, Tomomitsu
2013-03-01
We studied the diversity of Aedes breeding sites in various urban, suburban, and rural areas over time between February 2009 and February 2010 in the dengue endemic areas of Penang Island, Malaysia. We categorized the breeding sites and efficiency, and identified the key breeding containers. Among the 3 areas, the rural areas produced the highest container index (55), followed by suburban (42) and urban (32) areas. The numbers of key premises and containers were significantly higher (P < 0.000) in rural areas. The class 1 containers were identified as the key containers with higher productivity and efficiency, although class 2 and class 4 are the highest in numbers. Aedes aegypti immatures were found mostly in drums, water reservoirs, and polyethylene sheets, while mixed breeding was more common in buckets and empty paint cans in urban and suburban areas. Aedes albopictus was found mainly in miscellaneous containers such as drums, empty paint cans, and covers in all areas. The main potential containers indoors were drums, water reservoirs, and empty paint cans, and containers outdoors included empty paint cans, drums, and polyethylene sheets.
Carryer, P W; Brown, M I; Malagelada, J R; Carlson, G L; McCall, J T
1982-06-01
A radiolabeled cellulose (131I-fiber) that retains the essential physical and chemical properties of this class of fiber was developed in our laboratory. We quantified the fate of orally ingested 131I-fiber in healthy individuals by external gamma camera monitoring and fecal collections. The marker passes virtually intact through the human gastrointestinal tract with negligible release and absorption of the label in the gut. Comparison of the gastric emptying rate of 131I-fiber with that of a predominantly aqueous marker, 99mTc-diethylenetriamine pentaacetic acid (99mTc-DTPA), showed that 131I-fiber strands were evacuated more slowly than intragastric fluids. An important finding was that some 131I-fiber emptying occurred during most time periods, even before liquids were completely evacuated. This suggests that the human stomach is able to empty simultaneously liquids and fiber strands (1-15 mm in length) that are resistant to grinding by antral mechanical forces and to digestion by acid-peptic secretion. Thus, some nondigestible solids may be emptied with the bulk of a meal, although at a slower rate. 131I-Fiber may be a useful marker for quantifying gastric emptying of nondigestible solids. Further, the stability of 131I-fiber in the gut, as opposed to most other physiologic solid labels, should enable future investigation of intestinal and colonic transit of fiber, which is an important component of the human diet.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hashim, Marina; Abidin, Diana Atiqah Zainal; Das, Simon K.
The present study was conducted to investigate the food consumption pattern and gastric emptying time using x-radiography technique in scats fish, Scatophagus argus feeding to satiation in laboratory conditions. Prior to feeding experiment, fish of various sizes were examined their stomach volume, using freshly prepared stomachs ligatured at the tips of the burret, where the maximum amount of distilled water collected in the stomach were measured (ml). Stomach volume is correlated with maximum food intake (S{sub max}) and it can estimate the maximum stomach distension by allometric model i.e volume=0.0000089W{sup 2.93}. Gastric emptying time was estimated using a qualitative X-radiographymore » technique, where the fish of various sizes were fed to satiation at different time since feeding. All the experimental fish was feed into satiation using radio-opaque barium sulphate (BaSO{sub 4}) paste injected in the wet shrimp in proportion to the body weight. The BaSO{sub 4} was found suitable to track the movement of feed/prey in the stomach over time and gastric emptying time of scats fish can be estimated. The results of qualitative X-Radiography observation of gastric motility, showed the fish (200 gm) that fed to maximum satiation meal (circa 11 gm) completely emptied their stomach within 30 - 36 hrs. The results of the present study will provide the first baseline information on the stomach volume, gastric emptying of scats fish in captivity.« less
Yamawaki, Hiroshi; Futagami, Seiji; Shimpuku, Mayumi; Shindo, Tomotaka; Maruki, Yuuta; Nagoya, Hiroyuki; Kodaka, Yasuhiro; Sato, Hitomi; Gudis, Katya; Kawagoe, Tetsuro; Sakamoto, Choitsu
2015-01-01
Background/Aims There are no available data about the relationship between ghrelin gene genotypes and early phase of gastric emptying in functional dyspepsia (FD) as defined by Rome III classification. Methods We enrolled 74 patients presenting with typical symptoms of FD and 64 healthy volunteers. Gastric motility was evaluated using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms and self-rating questionnaires for depression (SRQ-D) scores to determine status of depression. The Arg51Gln (346G>A), preproghrelin (3056T>C), Leu72Met (408C>A), Gln90Leu (3412T>A) and G-protein β3 (825C>T) polymorphisms were analyzed in the DNA from blood samples of enrolled subjects. Genotyping was performed by polymerase chain reaction. Results There was a significant relationship between the Gln90Leu3412 genotype and SRQ-D score in FD patients (P = 0.009). Area under the curve at 15 minutes (AUC15) value was significantly associated with the Leu72Met408 genotype (P = 0.015) but not with entire gastric emptying. Conclusions The Leu72Met (408C>A) single nucleotide polymorphism was significantly associated with early phase of gastric emptying in FD patients. Further studies will be necessary to clarify the association between ghrelin gene single nucleotide polymorphisms and early phase of gastric emptying in FD patients. PMID:25540946
Yamawaki, Hiroshi; Futagami, Seiji; Shimpuku, Mayumi; Shindo, Tomotaka; Maruki, Yuuta; Nagoya, Hiroyuki; Kodaka, Yasuhiro; Sato, Hitomi; Gudis, Katya; Kawagoe, Tetsuro; Sakamoto, Choitsu
2015-01-01
There are no available data about the relationship between ghrelin gene genotypes and early phase of gastric emptying in functional dyspepsia (FD) as defined by Rome III classification. We enrolled 74 patients presenting with typical symptoms of FD and 64 healthy volunteers. Gastric motility was evaluated using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms and self-rating questionnaires for depression (SRQ-D) scores to determine status of depression. The Arg51Gln (346G->A), preproghrelin (3056T->C), Leu72Met (408C->A), Gln90Leu (3412T->A) and G-protein 3 (825C->T) polymorphisms were analyzed in the DNA from blood samples of enrolled subjects. Genotyping was performed by polymerase chain reaction. There was a significant relationship between the Gln90Leu3412 genotype and SRQ-D score in FD patients (P = 0.009). Area under the curve at 15 minutes (AUC15) value was significantly associated with the Leu72Met408 genotype (P = 0.015) but not with entire gastric emptying. The Leu72Met (408C->A) single nucleotide polymorphism was significantly associated with early phase of gastric emptying in FD patients. Further studies will be necessary to clarify the association between ghrelin gene single nucleotide polymorphisms and early phase of gastric emptying in FD patients.
NASA Astrophysics Data System (ADS)
Hashim, Marina; Abidin, Diana Atiqah Zainal; Das, Simon K.; Ghaffar, Mazlan Abd.
2014-09-01
The present study was conducted to investigate the food consumption pattern and gastric emptying time using x-radiography technique in scats fish, Scatophagus argus feeding to satiation in laboratory conditions. Prior to feeding experiment, fish of various sizes were examined their stomach volume, using freshly prepared stomachs ligatured at the tips of the burret, where the maximum amount of distilled water collected in the stomach were measured (ml). Stomach volume is correlated with maximum food intake (Smax) and it can estimate the maximum stomach distension by allometric model i.e volume=0.0000089W2.93. Gastric emptying time was estimated using a qualitative X-radiography technique, where the fish of various sizes were fed to satiation at different time since feeding. All the experimental fish was feed into satiation using radio-opaque barium sulphate (BaSO4) paste injected in the wet shrimp in proportion to the body weight. The BaSO4 was found suitable to track the movement of feed/prey in the stomach over time and gastric emptying time of scats fish can be estimated. The results of qualitative X-Radiography observation of gastric motility, showed the fish (200 gm) that fed to maximum satiation meal (circa 11 gm) completely emptied their stomach within 30 - 36 hrs. The results of the present study will provide the first baseline information on the stomach volume, gastric emptying of scats fish in captivity.
Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects.
Hlebowicz, Joanna; Darwiche, Gassan; Björgell, Ola; Almér, Lars-Olof
2007-06-01
Previous studies of patients with type 2 diabetes showed that cinnamon lowers fasting serum glucose, triacylglycerol, and LDL- and total cholesterol concentrations. We aimed to study the effect of cinnamon on the rate of gastric emptying, the postprandial blood glucose response, and satiety in healthy subjects. The gastric emptying rate (GER) was measured by using standardized real-time ultrasonography. Fourteen healthy subjects were assessed by using a crossover trial. The subjects were examined after an 8-h fast if they had normal fasting blood glucose concentrations. GER was calculated as the percentage change in the antral cross-sectional area 15-90 min after ingestion of 300 g rice pudding (GER1) or 300 g rice pudding and 6 g cinnamon (GER2). The median value of GER1 was 37%, and that of GER2 was 34.5%. The addition of cinnamon to the rice pudding significantly delayed gastric emptying and lowered the postprandial glucose response (P < 0.05 for both). The reduction in the postprandial blood glucose concentration was much more noticeable and pronounced than was the lowering of the GER. The effect of cinnamon on satiety was not significant. The intake of 6 g cinnamon with rice pudding reduces postprandial blood glucose and delays gastric emptying without affecting satiety. Inclusion of cinnamon in the diet lowers the postprandial glucose response, a change that is at least partially explained by a delayed GER.
Li, Dong-Sheng; Xu, Hui-Mian; Han, Chun-Qi; Li, Ya-Ming
2010-01-01
AIM: To determine the effect of three digestive tract reconstruction procedures on pouch function, after radical surgery undertaken because of gastric cancer, as assessed by radionuclide dynamic imaging. METHODS: As a measure of the reservoir function, with a designed diet containing technetium-99m (99mTc), the emptying time of the gastric substitute was evaluated using a 99mTc-labeled solid test meal. Immediately after the meal, the patient was placed in front of a γ camera in a supine position and the radioactivity was measured over the whole abdomen every minute. A frame image was obtained. The emptying sequences were recorded by the microprocessor and then stored on a computer disk. According to a computer processing system, the half-emptying actual curve and the fitting curve of food containing isotope in the detected region were depicted, and the half-emptying actual curves of the three reconstruction procedures were directly compared. RESULTS: Of the three reconstruction procedures, the half-emptying time of food containing isotope in the Dual Braun type esophagojejunal anastomosis procedure (51.86 ± 6.43 min) was far closer to normal, significantly better than that of the proximal gastrectomy orthotopic reconstruction (30.07 ± 15.77 min, P = 0.002) and P type esophagojejunal anastomosis (27.88 ± 6.07 min, P = 0.001) methods. The half-emptying actual curve and fitting curves for the Dual Braun type esophagojejunal anastomosis were fairly similar while those of the proximal gastrectomy orthotopic reconstruction and P type esophagojejunal anastomosis were obviously separated, which indicated bad food conservation in the reconstructed pouches. CONCLUSION: Dual Braun type esophagojejunal anastomosis is the most useful of the three procedures for improving food accommodation in patients with a pouch and can retard evacuation of solid food from the reconstructed pouch. PMID:20238408
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, JY; Hong, DL
Purpose: To investigate the impact of bladder filling status of the organs at risk (OARs) on dose distribution during intensity modulated radiotherapy (IMRT) for cervical cancer patients. Methods: Twelve cervical cancer patients treated with IMRT were selected for this study. The prescription dose was 45Gy/25 fractions with the 6 MV photon beam. All patients performed two CT scans, one with an empty bladder, the other one with bladder filled. For the registration of two CT scans, the fusion was automatically carried out upon the bony anatomy. The OARs (bladder, rectum, pelvic bone and small intestine) were delineated to planning CTmore » to evaluate the dose distributions. These dose distributions were compared between empty bladder and bladder filling. Results: The bladder volume with empty bladder and bladder filling was 403.2±124.13cc and 101.4±87.5cc, respectively. There were no statistical differences between empty bladder and bladder filling in the mean value of pelvic bone V10Gy, V20Gy, V40Gy; rectum V40Gy and V45Gy. The bladder V40Gy and V45Gy were lower in the bladder filling group than in the empty bladder group (63.7%±5.8% vs 87.5%±7.8%, 45.1%±9.5% vs 62.4%±11.8%, respectively). The V45Gy for small intestine in the bladder filling group was significantly less than the empty bladder group (146.7cc±95.3cc vs 245.7cc±101.8cc). Conclusion: Our study finds that the bladder filling status did not have a significant impact on dose distribution in the rectum and pelvic bone. However, the changes of bladder filling have a large impact on bladder and small intestine doses. A full bladder is strongly recommended during treatment for cervical cancer patients.« less
Horiuchi, Akira; Sakai, Ryosei; Tamaki, Michio; Kajiyama, Masashi; Tanaka, Naoki; Morikawa, Akio
2018-03-21
Aspiration is a common problem in bedridden gastrostomy-fed patients. We compared gastric emptying of an elemental liquid diet and a commercial semisolid diet in bedridden gastrostomy-fed patients. Study 1: from January 2013 to December 2016, consecutive bedridden patients receiving percutaneous endoscopic gastrostomy (PEG) semisolid feeding hospitalized due to aspiration pneumonia were switched to elemental liquid diet feedings. The frequency of defecation, tube feed contents aspirated from the trachea, and aspiration pneumonia during hospitalization were retrospectively reviewed. Study 2 was a randomized, crossover trial comparing C sodium acetate gastric emptying of a commercial elemental liquid or a commercial semisolid diet in bedridden PEG patients and controls. Study 1: 18 patients were enrolled. Elemental liquid diet was aspirated from the trachea in 1 (5.6%) (once in 24 observations); neither aspiration pneumonia nor diarrhea developed during elemental liquid diet feeding over 2 weeks observation. Study 2: 8 PEG patients and 8 healthy subjects were separately randomized to assess gastric emptying of the commercial elemental and semisolid diets. The elemental liquid diet was associated with a significant decrease of the 10%, 30%, or 50% emptying (excretion) time (P<0.05) and an increased the area under the curve (% dose/h) compared with the commercial semisolid diet (P<0.05). In healthy subjects there was no significant difference in gastric empting between the 2 diets. Elemental liquid diets emptied more rapidly from the stomach than semisolid diets in bedridden PEG patients. They may prevent or reduce aspiration pneumonia compared with semisolid diets.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.
Hjerpsted, Julie B; Flint, Anne; Brooks, Ashley; Axelsen, Mads B; Kvist, Trine; Blundell, John
2018-03-01
To investigate the effects of semaglutide on fasting and postprandial glucose and lipid responses, and on gastric emptying. This was a randomized, double-blind, placebo-controlled, 2-period, crossover trial. Subjects with obesity (N = 30) received once-weekly subcutaneous semaglutide, dose-escalated to 1.0 mg, or placebo. After each 12-week treatment period, glucose and lipid metabolism were assessed before and after standardized meals. Gastric emptying (paracetamol absorption test) and peptide YY (PYY) response were also assessed. Semaglutide treatment significantly lowered fasting concentrations of glucose and glucagon, and increased insulin vs placebo (estimated treatment ratio: 0.95 [95% confidence interval: 0.91, 0.98]; 0.86 [0.75, 0.98]; 1.45 [1.20, 1.75], respectively). Postprandial glucose metabolism significantly improved with semaglutide vs placebo (incremental area under the curve 0 to 5 hours [iAUC 0-5h ]; estimated treatment difference: glucose -1.34 mmol h/L [-2.42, -0.27]; insulin -921 pmol h/L [-1461, -381]; C-peptide -1.42 nmol h/L [-2.33, -0.51]). Fasting and postprandial lipid metabolism improved with semaglutide vs placebo. First-hour gastric emptying after the meal was delayed with semaglutide vs placebo (AUC 0-1h ; estimated treatment ratio: 0.73 [0.61, 0.87]); this may have contributed to the lower postprandial glucose increase in semaglutide-treated subjects. Overall gastric emptying (AUC 0-5h ) was not statistically different between treatments. Fasting and postprandial PYY responses were significantly lower with semaglutide vs placebo (P = .0397 and P = .0097, respectively). Semaglutide improved fasting and postprandial glucose and lipid metabolism. Overall gastric emptying was similar to that with placebo; however, the observed first-hour delay with semaglutide may contribute to a slower entry of glucose into the circulation. © 2017 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.
Wu, Tongzhi; Zhao, Beiyi R; Bound, Michelle J; Checklin, Helen L; Bellon, Max; Little, Tanya J; Young, Richard L; Jones, Karen L; Horowitz, Michael; Rayner, Christopher K
2012-01-01
Macronutrient "preloads" can stimulate glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), slow gastric emptying, and reduce postprandial glycemic excursions. After sweet preloads, these effects may be signaled by sodium-glucose cotransporter-1 (SGLT1), sweet taste receptors, or both. We determined the effects of 4 sweet preloads on GIP and GLP-1 release, gastric emptying, and postprandial glycemia. Ten healthy subjects were studied on 4 separate occasions each. A preload drink containing 40 g glucose, 40 g tagatose/isomalt mixture (TIM), 40 g 3-O-methylglucose (3OMG; a nonmetabolized substrate of SGLT1), or 60 mg sucralose was consumed 15 min before a (13)C-octanoic acid-labeled mashed potato meal. Blood glucose, plasma total GLP-1 and GIP, serum insulin, and gastric emptying were determined. Both glucose and 3OMG stimulated GLP-1 and GIP release in advance of the meal (each P < 0.05), whereas TIM and sucralose did not. The overall postprandial GLP-1 response was greater after glucose, 3OMG, and TIM than after sucralose (P < 0.05), albeit later after TIM than the other preloads. The blood glucose and insulin responses in the first 30 min after the meal were greatest after glucose (each P < 0.05). Gastric emptying was slower after both 3OMG and TIM than after sucralose (each P < 0.05). In healthy humans, SGLT1 substrates stimulate GLP-1 and GIP and slow gastric emptying, regardless of whether they are metabolized, whereas the artificial sweetener sucralose does not. Poorly absorbed sweet tastants (TIM), which probably expose a greater length of gut to nutrients, result in delayed GLP-1 secretion but not in delayed GIP release. These observations have the potential to optimize the use of preloads for glycemic control. This trial was registered at www.actr.org.au as ACTRN12611000775910.
Gullberg, Maria; Polacek, Charlotta; Bøtner, Anette; Belsham, Graham J
2013-11-01
The foot-and-mouth disease virus (FMDV) capsid protein precursor, P1-2A, is cleaved by 3C(pro) to generate VP0, VP3, VP1, and the peptide 2A. The capsid proteins self-assemble into empty capsid particles or viruses which do not contain 2A. In a cell culture-adapted strain of FMDV (O1 Manisa [Lindholm]), three different amino acid substitutions (E83K, S134C, and K210E) were identified within the VP1 region of the P1-2A precursor compared to the field strain (wild type [wt]). Expression of the O1 Manisa P1-2A (wt or with the S134C substitution in VP1) plus 3C(pro), using a transient expression system, resulted in efficient capsid protein production and self-assembly of empty capsid particles. Removal of the 2A peptide from the capsid protein precursor had no effect on capsid protein processing or particle assembly. However, modification of E83K alone abrogated particle assembly with no apparent effect on protein processing. Interestingly, the K210E substitution, close to the VP1/2A junction, completely blocked processing by 3C(pro) at this cleavage site, but efficient assembly of "self-tagged" empty capsid particles, containing the uncleaved VP1-2A, was observed. These self-tagged particles behaved like the unmodified empty capsids in antigen enzyme-linked immunosorbent assays and integrin receptor binding assays. Furthermore, mutant viruses with uncleaved VP1-2A could be rescued in cells from full-length FMDV RNA transcripts encoding the K210E substitution in VP1. Thus, cleavage of the VP1/2A junction is not essential for virus viability. The production of such engineered self-tagged empty capsid particles may facilitate their purification for use as diagnostic reagents and vaccines.
Effect of guar gum on gastric emptying in growing pigs.
Rainbird, A L; Low, A G
1986-01-01
1. Simple gastric cannulas were surgically fitted to four pigs, initially of 30 kg live weight, to examine the effects of guar gum on gastric emptying. 2. Four semi-purified high-fat diets based on starch, casein, soya-bean oil and tallow were given to each pig. They contained 0 (control), 20, 40 or 60 g powdered guar gum/kg diet. The meals as fed contained 257 g dry matter (DM)/kg. 3. The contents of the stomach were evacuated, with rinsing, before feeding or 0.5, 1, 2 or 4 h after feeding. 4. The mean pH of the digesta was unaffected by guar gum until 4 h after feeding when the value increased as the amount of guar gum in the diet rose. 5. The only significant effects of guar gum on the emptying of digesta and its components (compared with the control diet) were to reduce the rate of emptying of (a) digesta 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets), (b) dry matter and glucose 1 h after feeding (60 g/kg diet), (c) nitrogen 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets). 6. When expressed on a half-time (T50) basis, the emptying of digesta and N (but not of DM and glucose) were significantly slower for diets containing 40 and 60 g guar gum/kg than for the control diet. 7. The apparent viscosity of the gastric digesta ranged between 0.5 and 23.7% of the values for the diets as consumed. 8. It was concluded that the effects of guar gum on gastric emptying of high-solid meals were small, and that this was unlikely to be an important aspect of the mechanism by which guar gum reduces postprandial blood glucose concentrations.
Overexpression of SASH1 related to the decreased invasion ability of human glioma U251 cells.
Yang, Liu; Liu, Mei; Gu, Zhikai; Chen, Jianguo; Yan, Yaohua; Li, Jian
2012-12-01
The purpose of this study was to investigate the impact of SAM- and SH3-domain containing 1 (SASH1) on the biological behavior of glioma cells, including its effects on cellular growth, proliferation, apoptosis, invasion, and metastasis, and thereby to provide an experimental basis for future therapeutic treatments. A pcDNA3.1-SASH1 eukaryotic expression vector was constructed and transfected into the U251 human glioma cell line. Using the tetrazolium-based colorimetric (MTT) assay, flow cytometry analyses, transwell invasion chamber experiments, and other methods, we examined the impact of SASH1 on the biological behaviors of U251 cells, including effects on viability, cell cycle, apoptosis, and invasion. Furthermore, the effect of SASH1 on the expression of cyclin D1, caspase-3, matrix metalloproteinase (MMP)-2, MMP-9, and other proteins was observed. Compared to the empty vector and blank control groups, the pcDNA3.1-SASH1 group of U251 cells exhibited significantly reduced cell viability, proliferation, and invasion (p < 0.05), although there was no difference between the empty vector and blank control groups. The pcDNA3.1-SASH1 group demonstrated a significantly higher apoptotic index than did the empty vector and blank control groups (p < 0.05), and the percentage of apoptotic cells was similar between the empty vector and blank control groups. In addition, the pcDNA3.1-SASH1 group expressed significantly lower protein levels of cyclin D1 and MMP-2/9 compared to the control and empty vector groups (p < 0.05) and significantly higher protein levels of caspase-3 than the other two groups (p < 0.05). Cyclin D1, caspase-3, and MMP-2/9 expression was unchanged between the empty vector and blank control groups. SASH1 gene expression might be related to the inhibition of the growth, proliferation, and invasion of U251 cells and the promotion of U251 cells apoptosis.
Gallium-67 complexes as radioactive markers to assess gastric and colonic transit
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bellen, J.C.; Chatterton, B.E.; Penglis, S.
1995-03-01
Constipation and gastroparesis are gastrointestinal tract disorders that can be assessed by using radioactive markers in conjunction with scintigraphic techniques. Indium-111-DTPA is the radiopharmaceutical of choice for treating colonic transit in constipated patients, but it is an expensive product and its availability has been unreliable. Indium-113m-DTPA was the tracer used in our study to determine the liquid gastric emptying rate in dual-isotope solid-liquid emptying studies, however, cessation of the {sup 113}Sn/{sup 113m}In generator production makes it unavailable. Thus, development of alternative tracers to {sup 111}In-DTPA and {sup 113m}In-DTPA was essential. Gallium-67-citrate and {sup 67}Ga-EDTA were compared to {sup 111}In-DTPA tomore » assess their efficacy for exclusive retention in the GI tract. These markers were orally administered into rats and their three-day cumulative fecal excretion, urine excretion and carcass retention were measured. An in vitro gastric emptying model was used to determine liquid phase partitioning of {sup 113m}In-DTPA, {sup 67}Ga-citrate and {sup 67}Ga-EDTA at 37{degrees}. Gallium-67-citrate was predominantly excreted in the feces (97.2% {+-} 0.2%) after three days, with negligible urine excretion (0.1% {+-} 0.0%) and carcass retention (0.6% {+-} 0.2%). These results are analogous to those obtained for {sup 111}In-DTPA for fecal excretion (96.7% {+-} 2.6%), urine excretion (0.6% {+-} 0.0%) and retention in the carcass (0.2% {+-} 0.0%). Gallium-67-EDTA showed similar partitioning in the liquid phase of the gastric emptying model compared with {sup 113m}In-DTPA. Gallium-67-citrate is an economical and readily available alternative to {sup 111}In-DTPA as a colonic transit radiopharmaceutical. Gallium-67-EDTA is also an alternative to {sup 113m}In-DTPA for assessing liquid-phase emptying in a dual-isotope solid/liquid gastric emptying study. 17 refs., 3 figs., 2 tabs.« less
Giezenaar, Caroline; Trahair, Laurence G; Luscombe-Marsh, Natalie D; Hausken, Trygve; Standfield, Scott; Jones, Karen L; Lange, Kylie; Horowitz, Michael; Chapman, Ian; Soenen, Stijn
2017-09-01
Background: Protein- and energy-rich supplements are used widely for the management of malnutrition in the elderly. Information about the effects of protein on energy intake and related gastrointestinal mechanisms and whether these differ between men and women is limited. Objective: We determined the effects of whey protein on energy intake, appetite, gastric emptying, and gut hormones in healthy older men and women. Design: Eight older women and 8 older men [mean ± SEM age: 72 ± 1 y; body mass index (in kg/m 2 ): 25 ± 1] were studied on 3 occasions in which they received protein loads of 30 g (120 kcal) or 70 g (280 kcal) or a flavored water control drink (0 kcal). At regular intervals over 180 min, appetite (visual analog scales), gastric emptying (3-dimensional ultrasonography), and blood glucose and plasma gut-hormone concentrations [insulin, glucagon, ghrelin, cholecystokinin, gastric inhibitory polypeptide (GIP), glucagon-like peptide 1 (GLP-1), and peptide tyrosine tyrosine (PYY)] were measured, and ad libitum energy intake was quantified from a buffet meal (180-210 min; energy intake, appetite, and gastric emptying in the men have been published previously). Results: Energy intake at the buffet meal was ∼80% higher in older men than in older women ( P < 0.001). Energy intake was not suppressed by protein compared with the control in men or women ( P > 0.05). There was no effect of sex on gastric emptying, appetite, gastrointestinal symptoms, glucose, or gut hormones ( P > 0.05). There was a protein load-dependent slowing of gastric emptying, an increase in concentrations of insulin, glucagon, cholecystokinin, GIP, GLP-1, and PYY, and an increase in total energy intake (drink plus meal: 12% increase with 30 g and 32% increase with 70 g; P < 0.001). Energy intake at the buffet meal was inversely related to the stomach volume and area under the curve of hormone concentrations ( P < 0.05). Conclusion: In older men and women, whey-protein drinks load-dependently slow gastric emptying and alter gut hormone secretion compared with a control but have no suppressive effect on subsequent ad libitum energy intake. This trial was registered at www.anzctr.org.au as ACTRN12612000941864. © 2017 American Society for Nutrition.
Effect of pirfenidone on gastric emptying in a rat model.
Pan, Lin; Gelzleichter, Thomas; Chen, Yuan; Burg, Cindy; Limb, Susan L; Nguyen, Linda
2018-06-23
Gastrointestinal (GI) adverse events (AEs) are commonly reported in patients with idiopathic pulmonary fibrosis who are treated with pirfenidone. Taking pirfenidone with a substantial amount of food or dividing the dose over the course of a meal has been reported to reduce the frequency of GI AEs in clinical practice. In humans, the maximum plasma concentration (C max ) of pirfenidone was reduced when the drug was taken with food compared with the fasting state, and the lower C max was associated with a reduction in GI AE rates. In this study, the effects of the divided-dose approach and timing of pirfenidone administration relative to meal intake on gastric emptying were assessed using a rat model. The aim of this study was to investigate whether modification of dosing regimens could minimize pirfenidone's effect on inhibition of gastric emptying. Gastric emptying was assessed in male Sprague-Dawley rats after administration of a test meal by weighing stomach contents at various time points up to 120 min after the meal. Pirfenidone was administered via oral gavage either as a single-bolus dose of 30 mg/kg or as divided doses of 3 × 10 mg/kg at intervals ranging from 10 to 30 min for a total duration of 30-90 min. In addition, the test meal was given either at 30 min before, coincident with, or 30 min following pirfenidone oral administration. Administration of an oral 30-mg/kg single-bolus dose of pirfenidone with a meal resulted in a statistically significant decrease in gastric emptying in a rat model. The effect of pirfenidone on decreasing gastric emptying was lessened when the same total dose (i.e., 30 mg/kg) was administered as 3 divided doses (i.e., 3 × 10 mg/kg) over intervals up to 30 min in between each divided dose. Pharmacokinetic simulation suggested that a divided dosing regimen would decrease pirfenidone C max relative to single-bolus administration. When the same single-bolus dose of 30 mg/kg was administered 30 min following a meal rather than coincident with a meal, pirfenidone's effect on decreasing gastric emptying was reduced to the same extent as when the dose was divided as 3 × 10 mg/kg over a 90-min period. Administration of pirfenidone 30 min after a meal as a single-bolus dose or a divided dose over a 90-min period blunted pirfenidone's effect on inhibition of gastric emptying in rats compared with pirfenidone administration as a single-bolus dose coincident with a meal. Decreased gastric emptying, which is associated with pirfenidone administration, may be one of the contributing factors leading to GI tolerability issues associated with pirfenidone use in humans. Modification of the dosing regimen diminished this impact and may provide insight into possible mitigation strategies to minimize GI-related toxicities in the clinic. Copyright © 2018. Published by Elsevier Ltd.
The Mammalian Cell Cycle Regulates Parvovirus Nuclear Capsid Assembly
Riolobos, Laura; Domínguez, Carlos; Kann, Michael; Almendral, José M.
2015-01-01
It is unknown whether the mammalian cell cycle could impact the assembly of viruses maturing in the nucleus. We addressed this question using MVM, a reference member of the icosahedral ssDNA nuclear parvoviruses, which requires cell proliferation to infect by mechanisms partly understood. Constitutively expressed MVM capsid subunits (VPs) accumulated in the cytoplasm of mouse and human fibroblasts synchronized at G0, G1, and G1/S transition. Upon arrest release, VPs translocated to the nucleus as cells entered S phase, at efficiencies relying on cell origin and arrest method, and immediately assembled into capsids. In synchronously infected cells, the consecutive virus life cycle steps (gene expression, proteins nuclear translocation, capsid assembly, genome replication and encapsidation) proceeded tightly coupled to cell cycle progression from G0/G1 through S into G2 phase. However, a DNA synthesis stress caused by thymidine irreversibly disrupted virus life cycle, as VPs became increasingly retained in the cytoplasm hours post-stress, forming empty capsids in mouse fibroblasts, thereby impairing encapsidation of the nuclear viral DNA replicative intermediates. Synchronously infected cells subjected to density-arrest signals while traversing early S phase also blocked VPs transport, resulting in a similar misplaced cytoplasmic capsid assembly in mouse fibroblasts. In contrast, thymidine and density arrest signals deregulating virus assembly neither perturbed nuclear translocation of the NS1 protein nor viral genome replication occurring under S/G2 cycle arrest. An underlying mechanism of cell cycle control was identified in the nuclear translocation of phosphorylated VPs trimeric assembly intermediates, which accessed a non-conserved route distinct from the importin α2/β1 and transportin pathways. The exquisite cell cycle-dependence of parvovirus nuclear capsid assembly conforms a novel paradigm of time and functional coupling between cellular and virus life cycles. This junction may determine the characteristic parvovirus tropism for proliferative and cancer cells, and its disturbance could critically contribute to persistence in host tissues. PMID:26067441
Global Foot-and-Mouth Disease Research Update and Gap Analysis: 3 - Vaccines.
Robinson, L; Knight-Jones, T J D; Charleston, B; Rodriguez, L L; Gay, C G; Sumption, K J; Vosloo, W
2016-06-01
This study assessed research knowledge gaps in the field of FMDV (foot-and-mouth disease virus) vaccines. The study took the form of a literature review (2011-15) combined with research updates collected in 2014 from 33 institutes from across the world. Findings were used to identify priority areas for future FMD vaccine research. Vaccines play a vital role in FMD control, used both to limit the spread of the virus during epidemics in FMD-free countries and as the mainstay of disease management in endemic regions, particularly where sanitary controls are difficult to apply. Improvements in the performance or cost-effectiveness of FMD vaccines will allow more widespread and efficient disease control. FMD vaccines have changed little in recent decades, typically produced by inactivation of whole virus, the quantity and stability of the intact viral capsids in the final preparation being key for immunogenicity. However, these are exciting times and several promising novel FMD vaccine candidates have recently been developed. This includes the first FMD vaccine licensed for manufacture and use in the USA; this adenovirus-vectored FMD vaccine causes in vivo expression of viral capsids in vaccinated animals. Another promising vaccine candidate comprises stabilized empty FMDV capsids produced in vitro in a baculovirus expression system. Recombinant technologies are also being developed to improve otherwise conventionally produced inactivated vaccines, for example, by creating a chimeric vaccine virus to increase capsid stability and by inserting sequences into the vaccine virus for desired antigen expression. Other important areas of ongoing research include enhanced adjuvants, vaccine quality control procedures and predicting vaccine protection from immune correlates, thus reducing dependency on animal challenge studies. Globally, the degree of independent vaccine evaluation is highly variable, and this is essential for vaccine quality. Previously neglected, the importance of evaluating vaccination programme effectiveness and impact is increasingly being recognized. © 2016 Blackwell Verlag GmbH.
Robinson, John I; Beverley, Stephen M
2018-04-27
Leishmania is a widespread trypanosomatid protozoan parasite causing significant morbidity and mortality in humans. The endobiont dsRNA virus Leishmania RNA virus 1 (LRV1) chronically infects some strains, where it increases parasite numbers and virulence in murine leishmaniasis models, and correlates with increased treatment failure in human disease. Previously, we reported that 2'-C-methyladenosine (2CMA) potently inhibited LRV1 in Leishmania guyanensis ( Lgy ) and Leishmania braziliensis , leading to viral eradication at concentrations above 10 μm Here we probed the cellular mechanisms of 2CMA inhibition, involving metabolism, accumulation, and inhibition of the viral RNA-dependent RNA polymerase (RDRP). Activation to 2CMA triphosphate (2CMA-TP) was required, as 2CMA showed no inhibition of RDRP activity from virions purified on cesium chloride gradients. In contrast, 2CMA-TP showed IC 50 values ranging from 150 to 910 μm, depending on the CsCl density of the virion (empty, ssRNA-, and dsRNA-containing). Lgy parasites incubated in vitro with 10 μm 2CMA accumulated 2CMA-TP to 410 μm, greater than the most sensitive RDRP IC 50 measured. Quantitative modeling showed good agreement between the degree of LRV1 RDRP inhibition and LRV1 levels. These results establish that 2CMA activity is due to its conversion to 2CMA-TP, which accumulates to levels that inhibit RDRP and cause LRV1 loss. This attests to the impact of the Leishmania purine uptake and metabolism pathways, which allow even a weak RDRP inhibitor to effectively eradicate LRV1 at micromolar concentrations. Future RDRP inhibitors with increased potency may have potential therapeutic applications for ameliorating the increased Leishmania pathogenicity conferred by LRV1. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
78 FR 24037 - Airworthiness Directives; The Boeing Company Airplanes
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-24
... and to detect a pump running in an empty fuel tank. We are issuing this AD to reduce the potential of... features to detect electrical faults, to detect a pump running in an empty fuel tank, and to ensure that a fuel pump's operation is not affected by certain conditions. Comments We gave the public the...
27 CFR 31.231 - Destruction of marks and brands on wine containers.
Code of Federal Regulations, 2010 CFR
2010-04-01
... brands on wine containers. 31.231 Section 31.231 Alcohol, Tobacco Products and Firearms ALCOHOL AND... § 31.231 Destruction of marks and brands on wine containers. A dealer who empties any cask, barrel, keg, or other bulk container of wine must scrape or obliterate from the empty container all marks, brands...
ERIC Educational Resources Information Center
Clarken, Rodney
2010-01-01
Socrates' view of knowledge, Jesus' conception of love, Confucius' idea of virtue and Buddha's path of emptiness provide valuable insights and guiding principles to help us achieve a well-rounded education. Each of these individuals caused a transformation in the individual and collective lives of their followers and their respective societies…
The U.S. EPA estimated that during 1986 a total of 223 million empty pesticide containers were generated in the United States. Federal statutes regulate the handling and disposal of pesticide wastes, which include empty containers, equipment rinsate and excess or unwanted pestici...
ERIC Educational Resources Information Center
Namnoun, Donna
2002-01-01
Describes a school-wide, cross-curricular project called, "Empty Bowls", at Hall High School (West Hartford, Connecticut). Explains that students created ceramic bowls and made soup to fill the bowls to raise money to fight hunger. Provides a description of how the school became involved and raised the money. (CMK)
ERIC Educational Resources Information Center
Merritt, Dustin J.; Rugani, Rosa; Brannon, Elizabeth M.
2009-01-01
The goal of the current research was to explore whether monkeys possess conceptual precursors necessary for understanding zero. We trained rhesus monkeys on a nonsymbolic numerical matching-to-sample task, and on a numerical ordering task. We then introduced nondifferentially reinforced trials that contained empty sets to determine whether monkeys…
ERIC Educational Resources Information Center
Ioannou, Marios
2016-01-01
Proving that a given set is indeed a subgroup, one needs to show that it is non-empty, and closed under operation and inverses. This study focuses on the first condition, analysing students' responses to this task. Results suggest that there are three distinct problematic responses: the total absence of proving this condition, the problematic…
Hospital output forecasts and the cost of empty hospital beds.
Pauly, M V; Wilson, P
1986-01-01
This article investigates the cost incurred when hospitals have different levels of beds to treat a given number of patients. The cost of hospital care is affected by both the forecasted level of admissions and the actual number of admissions. When the relationship between forecasted and actual admissions is held constant, it is found that an empty hospital bed at a typical hospital in Michigan has a relatively low cost, about 13 percent or less of the cost of an occupied bed. However, empty beds in large hospitals do add significantly to cost. If hospital beds are closed, whether by closing beds at hospitals which remain in business or by closing entire hospitals, cost savings are estimated to be small. PMID:3759473
Bio-phenolic resin from oil palm empty fruit bunches
NASA Astrophysics Data System (ADS)
Zakaria, Zuhaili; Zakaria, Sarani; Roslan, Rasidi; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Amran, Umar Adli
2018-04-01
Utilization of oil palm empty fruit bunches (EFB) in the production of bio-phenolic resin is an alternative way to reduce the dependency of petroleum-based phenol. In this study, resol type bio-phenolic resin (BPR) was synthesized from EFB fibers using sulfuric acid as the catalyst to produce liquefied empty fruit bunches (LEFB) followed by resinification reaction with formaldehyde in alkaline condition. The SEM image of LEFB residue showed separation of fiber bundles into individual fibers. This indicate that lignin was destroyed during the liquefaction process. The increased of formaldehyde/LEFB molar ratio has resulted an increase of viscosity, solid content and pH of the resin. The obtained FTIR spectra confirmed that functional groups of BPR resins was almost similar with commercial resin.
Tensile Mechanical Property of Oil Palm Empty Fruit Bunch Fiber Reinforced Epoxy Composites
NASA Astrophysics Data System (ADS)
Ghazilan, A. L. Ahmad; Mokhtar, H.; Shaik Dawood, M. S. I.; Aminanda, Y.; Ali, J. S. Mohamed
2017-03-01
Natural, short, untreated and randomly oriented oil palm empty fruit bunch fiber reinforced epoxy composites were manufactured using vacuum bagging technique with 20% fiber volume composition. The performance of the composite was evaluated as an alternative to synthetic or conventional reinforced composites. Tensile properties such as tensile strength, modulus of elasticity and Poisson’s ratio were compared to the tensile properties of pure epoxy obtained via tensile tests as per ASTM D 638 specifications using Universal Testing Machine INSTRON 5582. The tensile properties of oil palm empty fruit bunch fiber reinforced epoxy composites were lower compared to plain epoxy structure with the decrement in performances of 38% for modulus of elasticity and 61% for tensile strength.
Diagnostic aptitude of West Nile virus-like particles expressed in insect cells.
Rebollo, Belén; Sarraseca, Javier; Rodríguez, Mª José; Sanz, Antonio; Jiménez-Clavero, Miguel Ángel; Venteo, Ángel
2018-02-10
West Nile virus is a globally spread zoonotic arbovirus. The laboratory diagnosis of WNV infection relies on virus identification by RT-PCR or on specific antibody detection by serological tests, such as ELISA or virus-neutralization. These methods usually require a preparation of the whole virus as antigen, entailing biosafety issues and therefore requiring BSL-3 facilities. For this reason, recombinant antigenic structures enabling effective antibody recognition comparable to that of the native virions, would be advantageous as diagnostic reagents. WNV virions are enveloped spherical particles made up of 3 structural proteins (C, capsid; M, membrane and E, envelope) enclosing the viral RNA. This study describes the co-expression of these 3 proteins yielding non-infectious virus-like particles (VLPs) and the results of the initial assessment of these VLPs, used instead of the whole virus, that were shown to perform correctly in two different ELISAs for WNV diagnosis. Copyright © 2018. Published by Elsevier Inc.
Ahn, Dae-Gyun; Kim, Se-Il; Rhee, Jin-Kyu; Kim, Kwang Pyo; Pan, Jae-Gu; Oh, Jong-Won
2006-08-01
A new virus-like particle TTSV1 was isolated from the hyperthermophilic crenarchaeote Thermoproteus tenax sampled at a hot spring region in Indonesia. TTSV1 had a spherical shape with a diameter of approximately 70 nm and was morphologically similar to the PSV isolated from a strain of Pyrobaculum. The 21.6 kb linear double-stranded DNA genome of TTSV1 had 38 open reading frames (ORFs), of which 15 ORFs were most similar to those of PSV. The remaining 23 ORFs showed little similarity to proteins in the public databases. Southern blot analysis demonstrated that the viral genome is not integrated into the host chromosome. TTSV1 consisted of three putative structural proteins of 10, 20, and 35 kDa in size, and the 10-kDa major protein was identified by mass spectrometry as a TTSV1 gene product. TTSV1 could be assigned as a new member of the newly emerged Globuloviridae family that includes so far only one recently characterized virus PSV.
Schröder, R; Maassen, A; Lippoldt, A; Börner, T; von Baehr, R; Dobrowolski, P
1991-08-01
Using the broad-host-range promoter probe vector pRS201 for cloning of phage Acm1 promoters, we established a convenient vector system for expression of heterologous genes in different Gram-negative bacteria. The usefulness of this system was demonstrated by expression of the HBV core gene in Acetobacter methanolicus. Plasmids carrying the HBV core gene downstream of different Acm1-phage promoters were transferred to A. methanolicus, a new potential host for recombinant DNA expression. Using enzyme immunoassay and immunoblot techniques, the amount and composition of core antigen produced in A. methanolicus were compared with that derived from Escherichia coli. The expression of immunoreactive core antigen in A. methanolicus exceeds by sevenfold that in E. coli using an expression system with tandemly arranged promoters. Morphological observations by electron microscopy show that the HBV core gene products isolated from both hosts are assembled into regular spherical particles with a diameter of about 28 nm that are comparable to original viral nucleocapsids.
NASA Astrophysics Data System (ADS)
Zhu, Boqin
2015-08-01
The purpose of using unmanned aerial vehicle (UAV) remote sensing application in Five-hundred-meter aperture spherical telescope (FAST) project is to dynamically record the construction process with high resolution image, monitor the environmental impact, and provide services for local environmental protection and the reserve immigrants. This paper introduces the use of UAV remote sensing system and the course design and implementation for the FAST site. Through the analysis of the time series data, we found that: (1) since the year 2012, the project has been widely carried out; (2) till 2013, the internal project begun to take shape;(3) engineering excavation scope was kept stable in 2014, and the initial scale of the FAST engineering construction has emerged as in the meantime, the vegetation recovery went well on the bare soil area; (4) in 2015, none environmental problems caused by engineering construction and other engineering geological disaster were found in the work area through the image interpretation of UAV images. This paper also suggested that the UAV technology need some improvements to fulfill the requirements of surveying and mapping specification., including a new data acquisition and processing measures assigned with the background of highly diverse elevation, usage of telephoto camera, hierarchical photography with different flying height, and adjustment with terrain using the joint empty three settlement method.
New generalized Noh solutions for HEDP hydrocode verification
NASA Astrophysics Data System (ADS)
Velikovich, A. L.; Giuliani, J. L.; Zalesak, S. T.; Tangri, V.
2017-10-01
The classic Noh solution describing stagnation of a cold ideal gas in a strong accretion shock wave has been the workhorse of compressible hydrocode verification for over three decades. We describe a number of its generalizations available for HEDP code verification. First, for an ideal gas, we have obtained self-similar solutions that describe adiabatic convergence either of a finite-pressure gas into an empty cavity or of a finite-amplitude sound wave into a uniform resting gas surrounding the center or axis of symmetry. At the moment of collapse such a flow produces a uniform gas whose velocity at each point is constant and directed towards the axis or the center, i. e. the initial condition similar to the classic solution but with a finite pressure of the converging gas. After that, a constant-velocity accretion shock propagates into the incident gas whose pressure and velocity profiles are not flat, in contrast with the classic solution. Second, for an arbitrary equation of state, we demonstrate the existence of self-similar solutions of the Noh problem in cylindrical and spherical geometry. Examples of such solutions with a three-term equation of state that includes cold, thermal ion/lattice, and thermal electron contributions are presented for aluminum and copper. These analytic solutions are compared to our numerical simulation results as an example of their use for code verification. Work supported by the US DOE/NNSA.
Gerbaix, Maude; Gnyubkin, Vasily; Farlay, Delphine; Olivier, Cécile; Ammann, Patrick; Courbon, Guillaume; Laroche, Norbert; Genthial, Rachel; Follet, Hélène; Peyrin, Françoise; Shenkman, Boris; Gauquelin-Koch, Guillemette; Vico, Laurence
2017-06-01
The weightless environment during spaceflight induces site-specific bone loss. The 30-day Bion-M1 mission offered a unique opportunity to characterize the skeletal changes after spaceflight and an 8-day recovery period in mature male C57/BL6 mice. In the femur metaphysis, spaceflight decreased the trabecular bone volume (-64% vs. Habitat Control), dramatically increased the bone resorption (+140% vs. Habitat Control) and induced marrow adiposity invasion. At the diaphysis, cortical thinning associated with periosteal resorption was observed. In the Flight animal group, the osteocyte lacunae displayed a reduced volume and a more spherical shape (synchrotron radiation analyses), and empty lacunae were highly increased (+344% vs. Habitat Control). Tissue-level mechanical cortical properties (i.e., hardness and modulus) were locally decreased by spaceflight, whereas the mineral characteristics and collagen maturity were unaffected. In the vertebrae, spaceflight decreased the overall bone volume and altered the modulus in the periphery of the trabecular struts. Despite normalized osteoclastic activity and an increased osteoblast number, bone recovery was not observed 8 days after landing. In conclusion, spaceflight induces osteocyte death, which may trigger bone resorption and result in bone mass and microstructural deterioration. Moreover, osteocyte cell death, lacunae mineralization and fatty marrow, which are hallmarks of ageing, may impede tissue maintenance and repair.
An outbreak of type C botulism in Herring Gulls (Larus argentatus) in Southeastern Sweden
Neimanis, A.; Gavier-Widen, D.; Leighton, F.; Bollinger, T.; Rocke, Tonie E.; Morner, T.
2007-01-01
From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls (Larus argentatus), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from a local landfill site and from Iceland, respectively, served as controls. All affected birds showed similar neurologic signs, ranging from mild incoordination and weakness to severe flaccid paralysis of legs and wings, but generally were alert and responsive. All affected gulls were in normal nutritional condition, but were dehydrated and had empty stomachs. No gross or microscopic lesions, and no bacterial or viral pathogens were identified. Type C botulinum toxin was detected in the sera of 11 of 16 (69%) affected gulls by mouse inoculation. Type C botulism was the proximate cause of disease in 2004. Sera from 31% of birds tested from outbreaks in 2000 to 2003 also had detectable type C botulinum toxin by mouse inoculation. No large-scale botulism outbreak has been documented previously in this area. The source of toxin, initiating conditions, and thus, the ultimate cause of this outbreak are not known. This epidemic might signal environmental change in the Baltic Sea.
An outbreak of type C botulism in herring gulls (Larus argentatus) in southeastern Sweden.
Neimanis, A; Gavier-Widén, D; Leighton, F; Bollinger, T; Rocke, T; Mörner, T
2007-07-01
From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls (Larus argentatus), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from a local landfill site and from Iceland, respectively, served as controls. All affected birds showed similar neurologic signs, ranging from mild incoordination and weakness to severe flaccid paralysis of legs and wings, but generally were alert and responsive. All affected gulls were in normal nutritional condition, but were dehydrated and had empty stomachs. No gross or microscopic lesions, and no bacterial or viral pathogens were identified. Type C botulinum toxin was detected in the sera of 11 of 16 (69%) affected gulls by mouse inoculation. Type C botulism was the proximate cause of disease in 2004. Sera from 31% of birds tested from outbreaks in 2000 to 2003 also had detectable type C botulinum toxin by mouse inoculation. No large-scale botulism outbreak has been documented previously in this area. The source of toxin, initiating conditions, and thus, the ultimate cause of this outbreak are not known. This epidemic might signal environmental change in the Baltic Sea.
Kainov, Denis E; Pirttimaa, Markus; Tuma, Roman; Butcher, Sarah J; Thomas, George J; Bamford, Dennis H; Makeyev, Eugene V
2003-11-28
Genomes of complex viruses have been demonstrated, in many cases, to be packaged into preformed empty capsids (procapsids). This reaction is performed by molecular motors translocating nucleic acid against the concentration gradient at the expense of NTP hydrolysis. At present, the molecular mechanisms of packaging remain elusive due to the complex nature of packaging motors. In the case of the double-stranded RNA bacteriophage phi 6 from the Cystoviridae family, packaging of single-stranded genomic precursors requires a hexameric NTPase, P4. In the present study, the purified P4 proteins from two other cystoviruses, phi 8 and phi 13, were characterized and compared with phi 6 P4. All three proteins are hexameric, single-stranded RNA-stimulated NTPases with alpha/beta folds. Using a direct motor assay, we found that phi 8 and phi 13 P4 hexamers translocate 5' to 3' along ssRNA, whereas the analogous activity of phi 6 P4 requires association with the procapsid. This difference is explained by the intrinsically high affinity of phi 8 and phi 13 P4s for nucleic acids. The unidirectional translocation results in RNA helicase activity. Thus, P4 proteins of Cystoviridae exhibit extensive similarity to hexameric helicases and are simple models for studying viral packaging motor mechanisms.
Heinrich, Henriette; Goetze, Oliver; Menne, Dieter; Iten, Peter X; Fruehauf, Heiko; Vavricka, Stephan R; Schwizer, Werner; Fried, Michael; Fox, Mark
2010-12-14
To compare the effects of drinking white wine or black tea with Swiss cheese fondue followed by a shot of cherry schnapps on gastric emptying, appetite, and abdominal symptoms. Randomised controlled crossover study. 20 healthy adults (14 men) aged 23-58. Cheese fondue (3260 kJ, 32% fat) labelled with 150 mg sodium (13)Carbon-octanoate was consumed with 300 ml of white wine (13%, 40 g alcohol) or black tea in randomised order, followed by 20 ml schnapps (40%, 8 g alcohol) or water in randomised order. Cumulative percentage dose of (13)C substrate recovered over four hours (higher values indicate faster gastric emptying) and appetite and dyspeptic symptoms (visual analogue scales). Gastric emptying was significantly faster when fondue was consumed with tea or water than with wine or schnapps (cumulative percentage dose of (13)C recovered 18.1%, 95% confidence interval 15.2% to 20.9% v 7.4%, 4.6% to 10.3%; P<0.001). An inverse dose-response relation between alcohol intake and gastric emptying was evident. Appetite was similar with consumption of wine or tea (difference 0.11, -0.12 to 0.34; P=0.35), but reduced if both wine and schnapps were consumed (difference -0.40, -0.01 to -0.79; P<0.046). No difference in dyspeptic symptoms was present. Gastric emptying after a Swiss cheese fondue is noticeably slower and appetite suppressed if consumed with higher doses of alcohol. This effect was not associated with dyspeptic symptoms. ClinicalTrials.gov NCT00943696.
Hostein, J; Capony, P; Busquet, G; Bost, R; Fournet, J
1985-04-01
For gastric emptying studies of a solid-liquid meal by the scintigraphic method, a valid isotope labeling method for each phase of the meal must be obtained. The aim of this study was to validate a simple chicken liver labeling method in normal subjects by multipuncture technic with 99mtechnetium. Labeling according to Meyer's method was chosen as a reference. Simultaneously, a study of the quality of liquid phase labeling by 111indium was done. The labeling process quality for each phase of the meal was assessed: a) in vitro, after incubation of the meal with human gastric juice (n = 12); b) in vivo, after meal ingestion and sequential collection of gastric contents by aspiration (n = 4). Furthermore, in 8 healthy volunteers, gastric emptying curves of the solid and liquid phases of the meal were determined scintigraphically and compared. Our results showed: a) for the solid phase: a good specificity of the marker, which was assessed in vitro and in vivo, after liver labeling with multipuncture technique (89 p. 100 and 92 p. 100 after 180 min, respectively); b) for the liquid phase: a good specificity of the marker in vitro and a poor specificity in vivo (82 p. 100 and 27 p. 100 after 180 min, respectively); c) similar half-gastric emptying times and cumulative percentages for the solid and liquid phases with both liver labeling methods. In conclusion, the multipuncture technique for chicken liver labeling may be used for gastric emptying studies in humans.
Barczyński, M; Thor, P
2001-08-01
The autonomic nervous system (ANS) function in hyperthyroidism has been so far investigated mainly from the cardiovascular point of view. The aim of this study is to show that the ANS dysfunction in hyperthyroidism is also expressed in gastric myoelectrical activity disturbances and gastric emptying disorders and to search for a correlation between the severity of clinical manifestation and free thyroid hormone levels and the degree of the ANS dysfunction. The analyzed group included 50 recently diagnosed patients with hyperthyroidism who were examined twice: before and after 3 months of thyrostatic treatment. Results were compared with those of a sex-, age- and BMI-matched control group of 50 healthy volunteers. The study included: heart rate variability analysis in time and frequency domain, at rest and during a deep-breathing test, surface electrogastrography in preprandial and postprandial periods measured simultaneously with the ultrasound assessment of gastric emptying time by Bolondi method. In patients with hyperthyroidism in comparison with the control group, the following significant differences were observed: a sharp reduction of the high-frequency component and a decrease of heart rate variability, a high incidence of dysrhythmia with dominant bradyarrhythmia, and a delay of gastric emptying. The degree of disorders related to the degree of clinical manifestation of hyperthyroidism's symptoms and free triiodothyronine serum concentration both. All the disorders were functional and disappeared in a stable euthyroidism. To conclude, the ANS dysfunction in hyperthyroidism results not only in withdrawal of vagal inhibitory effect on sinoatrial node, but in impaired mutual neuro-hormonal regulation (decrease of vagal influence) of gastric myoelectrical activity followed by delay of gastric emptying.
Hong, Sung K; Son, Hwancheol; Kim, Soo W; Oh, Seung-June; Choi, Hwang
2005-12-01
To investigate the effects of glycine on the recovery of bladder smooth muscle contractility after acute urinary retention. Bladder overdistension was induced in Sprague-Dawley rats by an infusion of saline (twice the threshold volume), maintained for 2 h. From 15 min before emptying of the bladder until 2 h after, saline or glycine solution was infused i.v. At 30 min, 2 h and 1 week after bladder emptying, samples of bladder tissue were taken for muscle strip study, malondialdehyde (MDA) assay, ATP assay, Western blotting for apoptosis-related molecules (Bcl-2, Bax, Caspase-3), and histological analysis including terminal deoxynucleotidyl transferase-mediated nick-end labelling staining. The results were compared among normal control, saline-treated and glycine-treated rats. In the glycine-treated group, muscle strip contractile responses induced by electrical-field stimulation and carbachol were both significantly greater at 1 week after bladder emptying than in the saline-treated group. The results of the ATP assay appeared to correspond with those of the muscle strip study. The saline-treated group had significantly higher MDA levels at 30 min after bladder emptying than the glycine-treated group. At 2 h after bladder emptying, there was significantly more apoptosis and greater leukocyte infiltration in the saline-treated group than in the glycine-treated group. While pro-apoptotic Bax and caspase-3 were down-regulated, Bcl-2 was up-regulated in the glycine-treated group. Glycine infusions might improve the contractile responses of bladder smooth muscle after acute urinary retention by reducing oxidative damage and apoptosis.
Changes in meal composition and duration affect postprandial endothelial function in healthy humans.
Thazhath, Sony S; Wu, Tongzhi; Bound, Michelle J; Checklin, Helen L; Jones, Karen L; Willoughby, Scott; Horowitz, Michael; Rayner, Christopher K
2014-12-15
Endothelial function, measured by flow-mediated dilatation (FMD), predicts cardiovascular events and is impaired postprandially. The objective of this study was to evaluate the effects of changes in composition or duration of ingestion of a meal, which slows gastric emptying and/or small intestinal nutrient exposure, on postprandial endothelial function. Twelve healthy subjects (6 male, 6 female; 33 ± 6 yr) were each studied on three occasions, in a randomized crossover design. After an overnight fast, subjects consumed a [(13)C]octanoic acid-labeled mashed potato meal ("meal 1"), or meal 1 mixed with 9 g guar ("meal 2") within 10 min, or meal 1 divided into 12 equal portions over 60 min ("meal 3"). Brachial artery FMD was measured every 30 min for 120 min. Blood glucose, serum insulin, and gastric emptying (breath test) were evaluated for 240 min. Data are means ± SE. Compared with meal 1, meal 2 was associated with slower gastric emptying (half-emptying time 285 ± 27 vs. 208 ± 15 min, P < 0.05), lower postprandial blood glucose and insulin (P < 0.001 for both), and a delayed, but more sustained, suppression of FMD (P < 0.001). After meal 3, both glycemic increment and reduction in FMD were less than after meal 2 (P < 0.05 for both). The decrement in FMD was directly related to the increment in blood glucose (r = 0.46, P = 0.02). We conclude that, in health, postprandial FMD is influenced by perturbation of gastric emptying and the duration of meal consumption, which also impact on glycemia. Copyright © 2014 the American Physiological Society.
Composition of growth of Holstein calves fed milk replacer from birth to 105-kilogram body weight.
Diaz, M C; Van Amburgh, M E; Smith, J M; Kelsey, J M; Hutten, E L
2001-04-01
Sixty calves were assigned to a comparative slaughter study to determine the changes in composition of milk replacer-fed Holstein bull calves from birth to 105-kg body weight (BW). Six calves were slaughtered on day of birth and served as a baseline for comparison of compositional changes. Fifty-four calves were assigned to one of three treatments (18 calves per treatment). Calves were fed milk replacer containing 30% crude protein (CP) and 20% fat. Target growth rates for treatments 1, 2, and 3 were 500, 950, and 1400 g/d, respectively. Six calves from each treatment were slaughtered and analyzed for energy, nitrogen, ether extract, and ash when they reached 65, 85 and 105 kg of BW. Actual daily gains from birth to slaughter were 560, 973, and 1100 g, and net deposition of CP and fat were 140 and 44, 204 and 154, and 247 and 161 g/d for treatments 1, 2, and 3, respectively. Results were used to develop equations to predict retained energy [retained energy = (empty BW(0.223)) x (empty BW gain(1.32))], and retained protein, [retained protein = (184 x empty BW gain (kilograms/d)) + (17.2 x (retained energy)/empty BW gain] where retained energy is in Mcal/d, retained protein is in g/d, and empty BW and gain are in kilograms. The composition of gain observed was compared to predictions from the 1989 Dairy NRC and 1996 Beef NRC equations and demonstrated the equations do not represent the composition of gain in calves of this weight.
Hydraulic Evaluation of Marmet Lock Filling and Emptying System, Kanawha River, West Virginia
2015-04-01
the culvert system was considered important because the lock design is a new In-chamber Longitudinal Culvert System (ILCS) that is found only on...emptying system during locking operations. A numerical model of the lock culvert system was developed to provide velocity and pressure information...35 6.1.3 Pressure on Inside of Culvert Bend
The Empty Nest Syndrome: Ways to Enhance Quality of Life
ERIC Educational Resources Information Center
Chen, Dianbing; Yang, Xinxiao; Aagard, Steve Dale
2012-01-01
Empty nest syndrome occurs as a result of urbanization and loosened relationships among family members. It may threaten the life quality of older adults and stability of society as a whole. This survey was designed to investigate the situation and factors that influence the life quality of a sample of older adults in a western state. Thirty-five…
The Empty Cup (Power Teaching in a Digital Age). Occasional Paper #9
ERIC Educational Resources Information Center
Fluellen, Jerry E., Jr.
2011-01-01
What might count as a world class, national public education system in 2020? That empty cup took the floor at the 2010 Future of Learning (FoL) Summer Institute at Harvard University. It traveled from Longfellow Hall's lecture room on Appian Way to several learning groups scattered around campus. Though not deliberately created to think about…
ERIC Educational Resources Information Center
Fluellen, Jerry E., Jr.
2008-01-01
What happens in a final project that fosters teaching for understanding? That inquiry calls to mind the Taoist belief that emptiness makes a cup useful. In the context of this paper, the inquiry organizes a narrative about how teaching for understanding surfaced in a "Theories of Learning" course at Edward Waters College. At a deeper…
A Generalization of the Euler-Fermat Theorem
ERIC Educational Resources Information Center
Harger, Robert T.; Harvey, Melinda E.
2003-01-01
This note considers the problem of determining, for fixed k and m, all values of r, 0 [less than] r [less than] [empty set](m), such that k[superscript [empty set](m)+1] [equivalent to] k[superscript r](mod m). More generally, if k, m and c are given, necessary and sufficient conditions are given for k[superscript c] [equivalent to] k[superscript…
Jinlan Cheng; Shao-Yuan Leu; J.Y. Zhu; Thomas W. Jeffries
2014-01-01
Sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL) was applied to an empty fruit bunches (EFB) for ethanol production. SPORL facilitated delignification through lignin sulfonation and dissolution of xylan to result in a highly digestible substrate. The pretreated whole slurry was enzymatically saccharified at a solids loading of 18% using a...