Science.gov

Sample records for spg13 compromises chaperonin

  1. Decreased expression of the mitochondrial matrix proteases Lon and ClpP in cells from a patient with hereditary spastic paraplegia (SPG13).

    PubMed

    Hansen, J; Corydon, T J; Palmfeldt, J; Dürr, A; Fontaine, B; Nielsen, M N; Christensen, J H; Gregersen, N; Bross, P

    2008-05-02

    The mitochondrial chaperonin heat shock protein 60 (Hsp60) assists the folding of a subset of proteins localized in mitochondria and is an essential component of the mitochondrial protein quality control system. Mutations in the HSPD1 gene that encodes Hsp60 have been identified in patients with an autosomal dominant form of hereditary spastic paraplegia (SPG13), a late-onset neurodegenerative disorder characterized by a progressive paraparesis of the lower limbs. The disease-associated Hsp60-(p.Val98Ile) protein, encoded by the c.292G>A HSPD1 allele, has reduced chaperonin activity, but how its expression affects mitochondrial functions has not been investigated. We have studied mitochondrial function and expression of genes encoding mitochondrial chaperones and proteases in a human lymphoblastoid cell line and fibroblast cells from a patient who is heterozygous for the c.292G>A HSPD1 allele. We found that both the c.292G>A RNA transcript and the corresponding Hsp60-(p.Val98Ile) protein were present at comparable levels to their wild-type counterparts in SPG13 patient cells. Compared with control cells, we found no significant cellular or mitochondrial dysfunctions in SPG13 patient cells by assessing the mitochondrial membrane potential, cell viability, and sensitivity toward oxidative stress. However, a decreased expression of the mitochondrial protein quality control proteases Lon and ClpP, both at the RNA and protein level, was demonstrated in SPG13 patient cells. We propose that decreased levels of mitochondrial proteases Lon and ClpP may allow Hsp60 substrate proteins to go through more folding attempts instead of being prematurely degraded, thereby supporting productive folding in cells with reduced Hsp60 chaperonin activity. In conclusion, our studies with SPG13 patient cells expressing the functionally impaired mutant Hsp60 chaperonin suggest that reduction of the degradative activity of the protein quality control system may represent a previously

  2. Data supporting mitochondrial morphological changes by SPG13-associated HSPD1 mutants.

    PubMed

    Miyamoto, Yuki; Megumi, Funakoshi-Tago; Hasegawa, Nanami; Eguchi, Takahiro; Tanoue, Akito; Tamura, Hiroomi; Yamauchi, Junji

    2016-03-01

    The data is related to the research article entitled "Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics" [1]. In addition to hypomyelinating leukodystrophy (HLD) 4 (OMIM no. 612233), it is known that spastic paraplegia (SPG) 13 (OMIM no. 605280) is caused by HSPD1's amino acid mutation. Two amino acid mutations Val-98-to-Ile (V98I) and Gln-461-to-Glu (Q461E) are associated with SPG13 [2]. In order to investigate the effects of HSPD1's V98I or Q461E mutant on mitochondrial morphological changes, we transfected each of the respective mutant-encoding genes into Cos-7 cells. Either of V98I or Q461E mutant exhibited increased number of mitochondria and short length mitochondrial morphologies. Using MitoTracker dye-incorporating assay, decreased mitochondrial membrane potential was also observed in both cases. The data described here supports that SPG13-associated HSPD1 mutant participates in causing aberrant mitochondrial morphological changes with decreased activities.

  3. Data supporting mitochondrial morphological changes by SPG13-associated HSPD1 mutants

    PubMed Central

    Miyamoto, Yuki; Megumi, Funakoshi-Tago; Hasegawa, Nanami; Eguchi, Takahiro; Tanoue, Akito; Tamura, Hiroomi; Yamauchi, Junji

    2016-01-01

    The data is related to the research article entitled “Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics” [1]. In addition to hypomyelinating leukodystrophy (HLD) 4 (OMIM no. 612233), it is known that spastic paraplegia (SPG) 13 (OMIM no. 605280) is caused by HSPD1’s amino acid mutation. Two amino acid mutations Val-98-to-Ile (V98I) and Gln-461-to-Glu (Q461E) are associated with SPG13 [2]. In order to investigate the effects of HSPD1’s V98I or Q461E mutant on mitochondrial morphological changes, we transfected each of the respective mutant-encoding genes into Cos-7 cells. Either of V98I or Q461E mutant exhibited increased number of mitochondria and short length mitochondrial morphologies. Using MitoTracker dye-incorporating assay, decreased mitochondrial membrane potential was also observed in both cases. The data described here supports that SPG13-associated HSPD1 mutant participates in causing aberrant mitochondrial morphological changes with decreased activities. PMID:26900593

  4. How do chaperonins fold protein?

    PubMed Central

    Motojima, Fumihiro

    2015-01-01

    Protein folding is a biological process that is essential for the proper functioning of proteins in all living organisms. In cells, many proteins require the assistance of molecular chaperones for their folding. Chaperonins belong to a class of molecular chaperones that have been extensively studied. However, the mechanism by which a chaperonin mediates the folding of proteins is still controversial. Denatured proteins are folded in the closed chaperonin cage, leading to the assumption that denatured proteins are completely encapsulated inside the chaperonin cage. In contrast to the assumption, we recently found that denatured protein interacts with hydrophobic residues at the subunit interfaces of the chaperonin, and partially protrude out of the cage. In this review, we will explain our recent results and introduce our model for the mechanism by which chaperonins accelerate protein folding, in view of recent findings. PMID:27493521

  5. Chaperonin filaments: The archael cytoskeleton

    SciTech Connect

    Trent, J.D.; Kagawa, H.K.; Yaoi, Takuro; Olle, E.; Zaluzec, N.J.

    1997-08-01

    Chaperonins are multi-subunit double-ring complexed composed of 60-kDa proteins that are believed to mediate protein folding in vivo. The chaperonins in the hyperthermophilic archaeon Sulfolobus shibatae are composed of the organism`s two most abundant proteins, which represent 4% of its total protein and have an intracellular concentration of {ge} 3.0 mg/ml. At concentrations of 1.0 mg/ml, purified chaperonin proteins aggregate to form ordered filaments. Filament formation, which requires Mg{sup ++} and nucleotide binding (not hydrolysis), occurs at physiological temperatures under conditions suggesting filaments may exist in vivo. If the estimated 4,600 chaperonins per cell, formed filaments in vivo, they could create a matrix of filaments that would span the diameter of an average S. shibatae cell 100 times. Direct observations of unfixed, minimally treated cells by intermediate voltage electron microscopy (300 kV) revealed an intracellular network of filaments that resembles chaperonin filaments produced in vitro. The hypothesis that the intracellular network contains chaperonins is supported by immunogold analyses. The authors propose that chaperonin activity may be regulated in vivo by filament formation and that chaperonin filaments may serve a cytoskeleton-like function in archaea and perhaps in other prokaryotes.

  6. Chaperonin function depends on structure and disorder in co-chaperonin mobile loops.

    PubMed

    Landry, S J; Steede, N K; Garaudy, A M; Maskos, K; Viitanen, P V

    1999-01-01

    Co-chaperonins from diverse organisms exhibit mobile loops which fold into a beta hairpin conformation upon binding to the chaperonin. GroES, Gp31, and human Hsp10 mobile loops exhibit a preference for the beta hairpin conformation in the free co-chaperonins, and the conformational dynamics of the human Hsp10 mobile loop appear to be restricted by nascent hairpin formation. Backbone conformational entropy must weigh against binding of co-chaperonins to chaperonins, and thus the conformational preferences of the loops may strongly influence chaperonin-binding affinity. Indeed, subtle mutations in the loops change GroEL-binding affinity and cause defects in chaperonin function, and these defects can be suppressed by mutations in GroEL which compensate for the changes in affinity. The fact that high-affinity co-chaperonin binding impairs chaperonin function has implications for the mechanism of chaperonin-assisted protein folding.

  7. Chaperonin filaments: The archaeal cytoskeleton?

    PubMed Central

    Trent, Jonathan D.; Kagawa, Hiromi K.; Yaoi, Takuro; Olle, Eric; Zaluzec, Nestor J.

    1997-01-01

    Chaperonins are high molecular mass double-ring structures composed of 60-kDa protein subunits. In the hyperthermophilic archaeon Sulfolobus shibatae the two chaperonin proteins represent ≈4% of its total protein and have a combined intracellular concentration of >30 mg/ml. At concentrations ≥ 0.5 mg/ml purified chaperonins form filaments in the presence of Mg2+ and nucleotides. Filament formation requires nucleotide binding (not hydrolysis), and occurs at physiological temperatures in biologically relevant buffers, including a buffer made from cell extracts. These observations suggest that chaperonin filaments may exist in vivo and the estimated 4600 chaperonins per cell suggest that such filaments could form an extensive cytostructure. We observed filamentous structures in unfixed, uranyl-acetate-stained S. shibatae cells, which resemble the chaperonin filaments in size and appearance. ImmunoGold (Janssen) labeling using chaperonin antibodies indicated that many chaperonins are associated with insoluble cellular structures and these structures appear to be filamentous in some areas, although they could not be uranyl-acetate-stained. The existence of chaperonin filaments in vivo suggests a mechanism whereby their protein-folding activities can be regulated. More generally, the filaments themselves may play a cytoskeletal role in Archaea. PMID:9144246

  8. Ordered biological nanostructures formed from chaperonin polypeptides

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan D. (Inventor); McMillan, R. Andrew (Inventor); Kagawa, Hiromi (Inventor); Paavola, Chad D. (Inventor)

    2010-01-01

    The following application relates to nanotemplates, nanostructures, nanoarrays and nanodevices formed from wild-type and mutated chaperonin polypeptides, methods of producing such compositions, methods of using such compositions and particular chaperonin polypeptides that can be utilized in producing such compositions.

  9. Ordered Nanostructures Made Using Chaperonin Polypeptides

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan; McMillan, Robert; Paavola, Chad; Mogul, Rakesh; Kagawa, Hiromi

    2004-01-01

    A recently invented method of fabricating periodic or otherwise ordered nanostructures involves the use of chaperonin polypeptides. The method is intended to serve as a potentially superior and less expensive alternative to conventional lithographic methods for use in the patterning steps of the fabrication of diverse objects characterized by features of the order of nanometers. Typical examples of such objects include arrays of quantum dots that would serve as the functional building blocks of future advanced electronic and photonic devices. A chaperonin is a double-ring protein structure having a molecular weight of about 60 plus or minus 5 kilodaltons. In nature, chaperonins are ubiquitous, essential, subcellular structures. Each natural chaperonin molecule comprises 14, 16, or 18 protein subunits, arranged as two stacked rings approximately 16 to 18 nm tall by approximately 15 to 17 nm wide, the exact dimensions depending on the biological species in which it originates. The natural role of chaperonins is unknown, but they are believed to aid in the correct folding of other proteins, by enclosing unfolded proteins and preventing nonspecific aggregation during assembly. What makes chaperonins useful for the purpose of the present method is that under the proper conditions, chaperonin rings assemble themselves into higher-order structures. This method exploits such higher-order structures to define nanoscale devices. The higher-order structures are tailored partly by choice of chemical and physical conditions for assembly and partly by using chaperonins that have been mutated. The mutations are made by established biochemical techniques. The assembly of chaperonin polypeptides into such structures as rings, tubes, filaments, and sheets (two-dimensional crystals) can be regulated chemically. Rings, tubes, and filaments of some chaperonin polypeptides can, for example, function as nano vessels if they are able to absorb, retain, protect, and release gases or

  10. Chaperonin-mediated Protein Folding

    PubMed Central

    Horwich, Arthur L.

    2013-01-01

    We have been studying chaperonins these past twenty years through an initial discovery of an action in protein folding, analysis of structure, and elucidation of mechanism. Some of the highlights of these studies were presented recently upon sharing the honor of the 2013 Herbert Tabor Award with my early collaborator, Ulrich Hartl, at the annual meeting of the American Society for Biochemistry and Molecular Biology in Boston. Here, some of the major findings are recounted, particularly recognizing my collaborators, describing how I met them and how our great times together propelled our thinking and experiments. PMID:23803606

  11. Thermostable chaperonin from Clostridium thermocellum.

    PubMed

    Cross, S J; Ciruela, A; Poomputsa, K; Romaniec, M P; Freedman, R B

    1996-06-01

    Homologues of the chaperonins Cpn60 and Cpn10 have been purified from the Gram-positive cellulolytic thermophile Clostridium thermocellum. The Cpn60 protein was purified by ATP-affinity chromatography and the Cpn10 protein was purified by gel-filtration, ion-exchange and hydrophobic interaction chromatographies. The identities of the proteins were confirmed by N-terminal sequence analysis and antigenic cross-reactivity. The Cpn60 homologue is a weak, thermostable ATPase (t1/2 at 70 decrees C more than 90 min) with optimum activity (Kcat 0.07 S-1) between 60 degrees C and 70 degrees C. The ATPase activity of the authentic Cpn60 was inhibited by Escherichia coli GroES. The catalytic properties of a recombinant C. thermocellum Cpn60 purified from a GST-Cpn60 fusion protein expressed in E. coli [Ciruela (1995) Ph.D. Thesis, University of Kent] were identical with those of the authentic C. thermocellum Cpn60. Gel-filtration studies show that at room temperature the Cpn60 migrates mainly as a heptamer. Electron microscopy confirms the presence of complexes showing 7-fold rotational symmetry and also reveals a small number of particles that seem to be tetradecamers with a similar structure to E. coli GroEL complexes.

  12. Mutant chaperonin proteins: new tools for nanotechnology

    NASA Astrophysics Data System (ADS)

    Li, Y.; Paavola, C. D.; Kagawa, H.; Chan, S. L.; Trent, J. D.

    2007-11-01

    Much effort has gone into finding peptides that bind potentially useful nanoparticles, but relatively little effort has focused on the scaffolds that organize these peptides into useful nanostructures. Chaperonins are protein complexes with 14-18 protein subunits that self-assemble into double-ring complexes and function as scaffolds for peptides or amino acids that bind metallic and semiconductor quantum dots. The utility of chaperonins as scaffolds depends on their structure and their ability to self-assemble into double-rings and higher-order structures, such as filaments and two-dimensional arrays. To better understand the structure of chaperonins, we constructed a model of a group II chaperonin and, based on this model, genetically constructed five mutant subunits with significant deletions. We expressed these mutants as recombinant proteins and observed by native polyacrylamide gel electrophoresis (PAGE) and transmission electron microscopy (TEM) that they all self-assembled into double rings. Our model predicted and TEM confirmed that these deletions did not significantly change the 17 nm diameter of the wild-type double rings, but decreased their height and opened their central cavities. Four of the five mutants formed higher-order structures: chains of rings, bundles of chains or filaments, and two-dimensional arrays, which we suggest can be useful nanostructures.

  13. The interaction network of the chaperonin CCT.

    PubMed

    Dekker, Carien; Stirling, Peter C; McCormack, Elizabeth A; Filmore, Heather; Paul, Angela; Brost, Renee L; Costanzo, Michael; Boone, Charles; Leroux, Michel R; Willison, Keith R

    2008-07-09

    The eukaryotic cytosolic chaperonin containing TCP-1 (CCT) has an important function in maintaining cellular homoeostasis by assisting the folding of many proteins, including the cytoskeletal components actin and tubulin. Yet the nature of the proteins and cellular pathways dependent on CCT function has not been established globally. Here, we use proteomic and genomic approaches to define CCT interaction networks involving 136 proteins/genes that include links to the nuclear pore complex, chromatin remodelling, and protein degradation. Our study also identifies a third eukaryotic cytoskeletal system connected with CCT: the septin ring complex, which is essential for cytokinesis. CCT interactions with septins are ATP dependent, and disrupting the function of the chaperonin in yeast leads to loss of CCT-septin interaction and aberrant septin ring assembly. Our results therefore provide a rich framework for understanding the function of CCT in several essential cellular processes, including epigenetics and cell division.

  14. Dynamics, flexibility, and allostery in molecular chaperonins.

    PubMed

    Skjærven, Lars; Cuellar, Jorge; Martinez, Aurora; Valpuesta, José María

    2015-09-14

    The chaperonins are a family of molecular chaperones present in all three kingdoms of life. They are classified into Group I and Group II. Group I consists of the bacterial variants (GroEL) and the eukaryotic ones from mitochondria and chloroplasts (Hsp60), while Group II consists of the archaeal (thermosomes) and eukaryotic cytosolic variants (CCT or TRiC). Both groups assemble into a dual ring structure, with each ring providing a protective folding chamber for nascent and denatured proteins. Their functional cycle is powered by ATP binding and hydrolysis, which drives a series of structural rearrangements that enable encapsulation and subsequent release of the substrate protein. Chaperonins have elaborate allosteric mechanisms to regulate their functional cycle. Long-range negative cooperativity between the two rings ensures alternation of the folding chambers. Positive intra-ring cooperativity, which facilitates concerted conformational transitions within the protein subunits of one ring, has only been demonstrated for Group I chaperonins. In this review, we describe our present understanding of the underlying mechanisms and the structure-function relationships in these complex protein systems with a particular focus on the structural dynamics, allostery, and associated conformational rearrangements.

  15. Potential for Modulation of the Hydrophobic Effect Inside Chaperonins

    PubMed Central

    England, Jeremy L.; Pande, Vijay S.

    2008-01-01

    Despite the spontaneity of some in vitro protein-folding reactions, native folding in vivo often requires the participation of barrel-shaped multimeric complexes known as chaperonins. Although it has long been known that chaperonin substrates fold upon sequestration inside the chaperonin barrel, the precise mechanism by which confinement within this space facilitates folding remains unknown. We examine the possibility that the chaperonin mediates a favorable reorganization of the solvent for the folding reaction. We discuss the effect of electrostatic charge on solvent-mediated hydrophobic forces in an aqueous environment. Based on these physical arguments, we construct a simple, phenomenological theory for the thermodynamics of density and hydrogen-bond order fluctuations in liquid water. Within the framework of this model, we investigate the effect of confinement inside a chaperonin-like cavity on the configurational free energy of water by calculating solvent free energies for cavities corresponding to the different conformational states in the ATP-driven catalytic cycle of the prokaryotic chaperonin GroEL. Our findings suggest that one function of chaperonins may involve trapping unfolded proteins and subsequently exposing them to a microenvironment in which the hydrophobic effect, a crucial thermodynamic driving force for folding, is enhanced. PMID:18599630

  16. Ordered nanoparticle arrays formed on engineered chaperonin protein templates

    NASA Technical Reports Server (NTRS)

    McMillan, R. Andrew; Paavola, Chad D.; Howard, Jeanie; Chan, Suzanne L.; Zaluzec, Nestor J.; Trent, Jonathan D.

    2002-01-01

    Traditional methods for fabricating nanoscale arrays are usually based on lithographic techniques. Alternative new approaches rely on the use of nanoscale templates made of synthetic or biological materials. Some proteins, for example, have been used to form ordered two-dimensional arrays. Here, we fabricated nanoscale ordered arrays of metal and semiconductor quantum dots by binding preformed nanoparticles onto crystalline protein templates made from genetically engineered hollow double-ring structures called chaperonins. Using structural information as a guide, a thermostable recombinant chaperonin subunit was modified to assemble into chaperonins with either 3 nm or 9 nm apical pores surrounded by chemically reactive thiols. These engineered chaperonins were crystallized into two-dimensional templates up to 20 microm in diameter. The periodic solvent-exposed thiols within these crystalline templates were used to size-selectively bind and organize either gold (1.4, 5 or 10nm) or CdSe-ZnS semiconductor (4.5 nm) quantum dots into arrays. The order within the arrays was defined by the lattice of the underlying protein crystal. By combining the self-assembling properties of chaperonins with mutations guided by structural modelling, we demonstrate that quantum dots can be manipulated using modified chaperonins and organized into arrays for use in next-generation electronic and photonic devices.

  17. Ordered nanoparticle arrays formed on engineered chaperonin protein templates

    NASA Technical Reports Server (NTRS)

    McMillan, R. Andrew; Paavola, Chad D.; Howard, Jeanie; Chan, Suzanne L.; Zaluzec, Nestor J.; Trent, Jonathan D.

    2002-01-01

    Traditional methods for fabricating nanoscale arrays are usually based on lithographic techniques. Alternative new approaches rely on the use of nanoscale templates made of synthetic or biological materials. Some proteins, for example, have been used to form ordered two-dimensional arrays. Here, we fabricated nanoscale ordered arrays of metal and semiconductor quantum dots by binding preformed nanoparticles onto crystalline protein templates made from genetically engineered hollow double-ring structures called chaperonins. Using structural information as a guide, a thermostable recombinant chaperonin subunit was modified to assemble into chaperonins with either 3 nm or 9 nm apical pores surrounded by chemically reactive thiols. These engineered chaperonins were crystallized into two-dimensional templates up to 20 microm in diameter. The periodic solvent-exposed thiols within these crystalline templates were used to size-selectively bind and organize either gold (1.4, 5 or 10nm) or CdSe-ZnS semiconductor (4.5 nm) quantum dots into arrays. The order within the arrays was defined by the lattice of the underlying protein crystal. By combining the self-assembling properties of chaperonins with mutations guided by structural modelling, we demonstrate that quantum dots can be manipulated using modified chaperonins and organized into arrays for use in next-generation electronic and photonic devices.

  18. The Molecular Basis of Hyperthermophily: The Role of HSP60/Chaperonins In Vivo

    NASA Technical Reports Server (NTRS)

    Kagawa, Hiromi

    2002-01-01

    In this study, we aim to understand how S. shibatae copes with high temperatures. In particular, we investigated the role of the 60 kDa heat shock protein (HSP60 or chaperonin) with the hypothesis that chaperonin stabilizes the cell membrane under stressful conditions. To prove the hypothesis, this year two questions were addressed: (1) Is the chaperonin localized in the cytoplasm or on the cell membrane? (2) Does the chaperonin show affinity to lipid in vivo? In addition to those, we intensively studied newly discovered chaperonin-related protein, gamma, to understand how it influenced the function of the other components of chaperonin and how their combined activities contributed to hyperthermophily.

  19. Chaperonin Polymers in Archaea: The Cytoskeleton of Prokaryotes?

    DOE R&D Accomplishments Database

    Trent, J. D.; Kagawa, H. K.; Zaluzec, N. J.

    1997-07-01

    Chaperonins are protein complexes that play a critical role in folding nascent polypeptides under normal conditions and refolding damaged proteins under stress conditions. In all organisms these complexes are composed of evolutionarily conserved 60-kDa proteins arranged in double-ring structures with between 7 and 9 protein subunits per ring. These double ring structures are assumed to be the functional units in vivo, although they have never been observed inside cells. Here the authors show that the purified chaperonin from the hyperthermophilic archaeon Sulfolobus shibatae, which is closely related to chaperonins in eukaryotes, has a double ring structure at low concentrations (0.1 mg/ml), but at more physiological concentrations, the rings stack end to end to form polymers. The polymers are stable at physiological temperatures (75 C) and closely resemble structures observed inside unfixed S. shibatae cells. The authors suggest that in vivo chaperonin activity may be regulated by polymerization and that chaperonin polymers may act as a cytoskeleton-like structure in archaea and bacteria.

  20. Cpn20: siamese twins of the chaperonin world.

    PubMed

    Weiss, Celeste; Bonshtien, Anat; Farchi-Pisanty, Odelia; Vitlin, Anna; Azem, Abdussalam

    2009-02-01

    The chloroplast cpn20 protein is a functional homolog of the cpn10 co-chaperonin, but its gene consists of two cpn10-like units joined head-to-tail by a short chain of amino acids. This double protein is unique to plastids and was shown to exist in plants as well plastid-containing parasites. In vitro assays showed that this cpn20 co-chaperonin is a functional homolog of cpn10. In terms of structure, existing data indicate that the oligomer is tetrameric, yet it interacts with a heptameric cpn60 partner. Thus, the functional oligomeric structure remains a mystery. In this review, we summarize what is known about this distinctive chaperonin and use a bioinformatics approach to examine the expression of cpn20 in Arabidopsis thaliana relative to other chaperonin genes in this species. In addition, we examine the primary structure of the two homologous domains for similarities and differences, in comparison with cpn10 from other species. Lastly, we hypothesize as to the oligomeric structure and raison d'être of this unusual co-chaperonin homolog.

  1. Chaperonin polymers in archaea: The cytoskeleton of prokaryotes?

    SciTech Connect

    Trent, J.D.; Kagawa, H.K.; Zaluzec, N.J.

    1997-07-01

    Chaperonins are protein complexes that play a critical role in folding nascent polypeptides under normal conditions and refolding damaged proteins under stress conditions. In all organisms these complexes are composed of evolutionarily conserved 60-kDa proteins arranged in double-ring structures with between 7 and 9 protein subunits per ring. These double ring structures are assumed to be the functional units in vivo, although they have never been observed inside cells. Here the authors show that the purified chaperonin from the hyperthermophilic archaeon Sulfolobus shibatae, which is closely related to chaperonins in eukaryotes, has a double ring structure at low concentrations (0.1 mg/ml), but at more physiological concentrations, the rings stack end to end to form polymers. The polymers are stable at physiological temperatures (75 C) and closely resemble structures observed inside unfixed S. shibatae cells. The authors suggest that in vivo chaperonin activity may be regulated by polymerization and that chaperonin polymers may act as a cytoskeleton-like structure in archaea and bacteria.

  2. Dynamic Complexes in the Chaperonin-Mediated Protein Folding Cycle

    PubMed Central

    Weiss, Celeste; Jebara, Fady; Nisemblat, Shahar; Azem, Abdussalam

    2016-01-01

    The GroEL–GroES chaperonin system is probably one of the most studied chaperone systems at the level of the molecular mechanism. Since the first reports of a bacterial gene involved in phage morphogenesis in 1972, these proteins have stimulated intensive research for over 40 years. During this time, detailed structural and functional studies have yielded constantly evolving concepts of the chaperonin mechanism of action. Despite of almost three decades of research on this oligomeric protein, certain aspects of its function remain controversial. In this review, we highlight one central aspect of its function, namely, the active intermediates of its reaction cycle, and present how research to this day continues to change our understanding of chaperonin-mediated protein folding. PMID:28008398

  3. Evolution of Chaperonin Gene Duplication in Stigonematalean Cyanobacteria (Subsection V)

    PubMed Central

    Weissenbach, Julia; Ilhan, Judith; Hülter, Nils; Stucken, Karina; Dagan, Tal

    2017-01-01

    Chaperonins promote protein folding and are known to play a role in the maintenance of cellular stability under stress conditions. The group I bacterial chaperonin complex comprises GroEL, that forms a barrel-like oligomer, and GroES that forms the lid. In most eubacteria the GroES/GroEL chaperonin is encoded by a single-copy bicistronic operon, whereas in cyanobacteria up to three groES/groEL paralogs have been documented. Here we study the evolution and functional diversification of chaperonin paralogs in the heterocystous, multi-seriate filament forming cyanobacterium Chlorogloeopsis fritschii PCC 6912. The genome of C. fritschii encodes two groES/groEL operons (groESL1, groESL1.2) and a monocistronic groEL gene (groEL2). A phylogenetic reconstruction reveals that the groEL2 duplication is as ancient as cyanobacteria, whereas the groESL1.2 duplication occurred at the ancestor of heterocystous cyanobacteria. A comparison of the groEL paralogs transcription levels under different growth conditions shows that they have adapted distinct transcriptional regulation. Our results reveal that groEL1 and groEL1.2 are upregulated during diazotrophic conditions and the localization of their promoter activity points towards a role in heterocyst differentiation. Furthermore, protein–protein interaction assays suggest that paralogs encoded in the two operons assemble into hybrid complexes. The monocistronic encoded GroEL2 is not forming oligomers nor does it interact with the co-chaperonins. Interaction between GroES1.2 and GroEL1.2 could not be documented, suggesting that the groESL1.2 operon does not encode a functional chaperonin complex. Functional complementation experiments in Escherichia coli show that only GroES1/GroEL1 and GroES1/GroEL1.2 can substitute the native operon. In summary, the evolutionary consequences of chaperonin duplication in cyanobacteria include the retention of groESL1 as a housekeeping gene, subfunctionalization of groESL1.2 and

  4. Evolution of Chaperonin Gene Duplication in Stigonematalean Cyanobacteria (Subsection V).

    PubMed

    Weissenbach, Julia; Ilhan, Judith; Bogumil, David; Hülter, Nils; Stucken, Karina; Dagan, Tal

    2017-01-12

    Chaperonins promote protein folding and are known to play a role in the maintenance of cellular stability under stress conditions. The group I bacterial chaperonin complex comprises GroEL, that forms a barrel-like oligomer, and GroES that forms the lid. In most eubacteria the GroES/GroEL chaperonin is encoded by a single-copy bicistronic operon, whereas in cyanobacteria up to three groES/groEL paralogs have been documented. Here we study the evolution and functional diversification of chaperonin paralogs in the heterocystous, multi-seriate filament forming cyanobacterium Chlorogloeopsis fritschii PCC 6912. The genome of C. fritschii encodes two groES/groEL operons (groESL1, groESL1.2) and a monocistronic groEL gene (groEL2). A phylogenetic reconstruction reveals that the groEL2 duplication is as ancient as cyanobacteria, whereas the groESL1.2 duplication occurred at the ancestor of heterocystous cyanobacteria. A comparison of the groEL paralogs transcription levels under different growth conditions shows that they have adapted distinct transcriptional regulation. Our results reveal that groEL1 and groEL1.2 are upregulated during diazotrophic conditions and the localization of their promoter activity points towards a role in heterocyst differentiation. Furthermore, protein-protein interaction assays suggest that paralogs encoded in the two operons assemble into hybrid complexes. The monocistronic GroEL2 is not forming oligomers nor does it interact with the co-chaperonins. Interaction between GroES1.2 and GroEL1.2 could not be documented, suggesting that the groESL1.2 operon does not encode a functional chaperonin complex. Functional complementation experiments in Escherichia coli show that only GroES1/GroEL1 and GroES1/GroEL1.2 can substitute the native operon. In summary, the evolutionary consequences of chaperonin duplication in cyanobacteria include the retention of groESL1 as a housekeeping gene, subfunctionalization of groESL1.2 and neofunctionalization of the

  5. Chaperonin filaments : their formation and an evaluation of methods for studying them.

    SciTech Connect

    Yaoi, T.; Kagawa, K. H.; Trent, J. D.; Center for Mechanistic Biology and Biotechnology

    1998-08-01

    Chaperonins are multisubunit protein complexes that can be isolated from cells as high-molecular-weight structures that appear as double rings in the electron microscope. We recently discovered that chaperonin double rings isolated from the hyperthermophilic archaeon Sulfolobus shibatae, when incubated at physiological temperatures in the presence of ATP and Mg{sup 2+}, stacked into filaments; we hypothesized that these filaments are related to filaments seen inside S. shibatae cells and that chaperonins exist as filaments in vivo. This paper elucidates the conditions under which we have observed S. shibatae chaperonins to form filaments and evaluates native polyacrylamide gel electrophoresis (PAGE), TEM, spectrophotometry, and centrifugation as methods for studying these filaments. We observed that in the presence of Mg{sup 2+} combined with ATP, ADP, ATP{gamma}S, or GTP, native PAGE indicated that chaperonin subunits assembled into double rings and that the conformation of these double rings was effected by nucleotide binding, but we saw no indication of chaperonin filament formation. Under these same conditions, however, TEM, spectroscopy, and centrifugation methods indicated that chaperonin subunits and double rings had assembled into filaments. We determined that this discrepancy in the representation of the chaperonin structure was due to the native PAGE method itself. When we exposed chaperonin filaments to the electrophoretic field used in native PAGE, the filaments dissociated into double rings. This suggests that TEM, spectrophotometry, and centrifugation are the preferred methods for studying the higher-order structures of chaperonins, which are likely to be of biological significance.

  6. Versatile platform for nanotechnology based on circular permutations of chaperonin protein

    NASA Technical Reports Server (NTRS)

    Paavola, Chad D. (Inventor); Trent, Jonathan D. (Inventor); Chan, Suzanne L. (Inventor); Li, Yi-Fen (Inventor); McMillan, R. Andrew (Inventor); Kagawa, Hiromi (Inventor)

    2010-01-01

    The present invention provides chaperonin polypeptides which are modified to include N-terminal and C-terminal ends that are relocated from the central pore region to various different positions in the polypeptide which are located on the exterior of the folded modified chaperonin polypeptide. In the modified chaperonin polypeptide, the naturally-occurring N-terminal and C-terminal ends are joined together directly or with an intervening linker peptide sequence. The relocated N-terminal or C-terminal ends can be covalently joined to, or bound with another molecule such as a nucleic acid molecule, a lipid, a carbohydrate, a second polypeptide, or a nanoparticle. The modified chaperonin polypeptides can assemble into double-ringed chaperonin structures. Further, the chaperonin structures can organize into higher order structures such as nanofilaments or nanoarrays which can be used to produce nanodevices and nanocoatings.

  7. Mechanism of folding chamber closure in a group II chaperonin.

    PubMed

    Zhang, Junjie; Baker, Matthew L; Schröder, Gunnar F; Douglas, Nicholai R; Reissmann, Stefanie; Jakana, Joanita; Dougherty, Matthew; Fu, Caroline J; Levitt, Michael; Ludtke, Steven J; Frydman, Judith; Chiu, Wah

    2010-01-21

    Group II chaperonins are essential mediators of cellular protein folding in eukaryotes and archaea. These oligomeric protein machines, approximately 1 megadalton, consist of two back-to-back rings encompassing a central cavity that accommodates polypeptide substrates. Chaperonin-mediated protein folding is critically dependent on the closure of a built-in lid, which is triggered by ATP hydrolysis. The structural rearrangements and molecular events leading to lid closure are still unknown. Here we report four single particle cryo-electron microscopy (cryo-EM) structures of Mm-cpn, an archaeal group II chaperonin, in the nucleotide-free (open) and nucleotide-induced (closed) states. The 4.3 A resolution of the closed conformation allowed building of the first ever atomic model directly from the single particle cryo-EM density map, in which we were able to visualize the nucleotide and more than 70% of the side chains. The model of the open conformation was obtained by using the deformable elastic network modelling with the 8 A resolution open-state cryo-EM density restraints. Together, the open and closed structures show how local conformational changes triggered by ATP hydrolysis lead to an alteration of intersubunit contacts within and across the rings, ultimately causing a rocking motion that closes the ring. Our analyses show that there is an intricate and unforeseen set of interactions controlling allosteric communication and inter-ring signalling, driving the conformational cycle of group II chaperonins. Beyond this, we anticipate that our methodology of combining single particle cryo-EM and computational modelling will become a powerful tool in the determination of atomic details involved in the dynamic processes of macromolecular machines in solution.

  8. Essential role of the chaperonin folding compartment in vivo

    PubMed Central

    Tang, Yun-Chi; Chang, Hung-Chun; Chakraborty, Kausik; Hartl, F Ulrich; Hayer-Hartl, Manajit

    2008-01-01

    The GroEL/GroES chaperonin system of Escherichia coli forms a nano-cage allowing single protein molecules to fold in isolation. However, as the chaperonin can also mediate folding independently of substrate encapsulation, it remained unclear whether the folding cage is essential in vivo. To address this question, we replaced wild-type GroEL with mutants of GroEL having either a reduced cage volume or altered charge properties of the cage wall. A stepwise reduction in cage size resulted in a gradual loss of cell viability, although the mutants bound non-native protein efficiently. Strikingly, a mild reduction in cage size increased the yield and the apparent rate of green fluorescent protein folding, consistent with the view that an effect of steric confinement can accelerate folding. As shown in vitro, the observed acceleration of folding was dependent on protein encapsulation by GroES but independent of GroES cycling regulated by the GroEL ATPase. Altering the net-negative charge of the GroEL cage wall also strongly affected chaperonin function. Based on these findings, the GroEL/GroES compartment is essential for protein folding in vivo. PMID:18418386

  9. Mechanism of nucleotide sensing in group II chaperonins

    PubMed Central

    Pereira, Jose H; Ralston, Corie Y; Douglas, Nicholai R; Kumar, Ramya; Lopez, Tom; McAndrew, Ryan P; Knee, Kelly M; King, Jonathan A; Frydman, Judith; Adams, Paul D

    2012-01-01

    Group II chaperonins mediate protein folding in an ATP-dependent manner in eukaryotes and archaea. The binding of ATP and subsequent hydrolysis promotes the closure of the multi-subunit rings where protein folding occurs. The mechanism by which local changes in the nucleotide-binding site are communicated between individual subunits is unknown. The crystal structure of the archaeal chaperonin from Methanococcus maripaludis in several nucleotides bound states reveals the local conformational changes associated with ATP hydrolysis. Residue Lys-161, which is extremely conserved among group II chaperonins, forms interactions with the γ-phosphate of ATP but shows a different orientation in the presence of ADP. The loss of the ATP γ-phosphate interaction with Lys-161 in the ADP state promotes a significant rearrangement of a loop consisting of residues 160–169. We propose that Lys-161 functions as an ATP sensor and that 160–169 constitutes a nucleotide-sensing loop (NSL) that monitors the presence of the γ-phosphate. Functional analysis using NSL mutants shows a significant decrease in ATPase activity, suggesting that the NSL is involved in timing of the protein folding cycle. PMID:22193720

  10. Functionality and Evolutionary History of the Chaperonins in Thermophilic Archaea. A Bioinformatical Perspective

    NASA Technical Reports Server (NTRS)

    Karlin, Samuel

    2004-01-01

    We used bioinformatics methods to study phylogenetic relations and differentiation patterns of the archaeal chaperonin 60 kDa heat-shock protein (HSP60) genes in support of the study of differential expression patterns of the three chaperonin genes encoded in Sulfolobus shibatae.

  11. Novel chaperonins are prevalent in the virioplankton and demonstrate links to viral biology and ecology.

    PubMed

    Marine, Rachel L; Nasko, Daniel J; Wray, Jeffrey; Polson, Shawn W; Wommack, K Eric

    2017-07-21

    Chaperonins are protein-folding machinery found in all cellular life. Chaperonin genes have been documented within a few viruses, yet, surprisingly, analysis of metagenome sequence data indicated that chaperonin-carrying viruses are common and geographically widespread in marine ecosystems. Also unexpected was the discovery of viral chaperonin sequences related to thermosome proteins of archaea, indicating the presence of virioplankton populations infecting marine archaeal hosts. Virioplankton large subunit chaperonin sequences (GroELs) were divergent from bacterial sequences, indicating that viruses have carried this gene over long evolutionary time. Analysis of viral metagenome contigs indicated that: the order of large and small subunit genes was linked to the phylogeny of GroEL; both lytic and temperate phages may carry group I chaperonin genes; and viruses carrying a GroEL gene likely have large double-stranded DNA (dsDNA) genomes (>70 kb). Given these connections, it is likely that chaperonins are critical to the biology and ecology of virioplankton populations that carry these genes. Moreover, these discoveries raise the intriguing possibility that viral chaperonins may more broadly alter the structure and function of viral and cellular proteins in infected host cells.The ISME Journal advance online publication, 21 July 2017; doi:10.1038/ismej.2017.102.

  12. A mobile loop order–disorder transition modulates the speed of chaperonin cycling

    PubMed Central

    Shewmaker, Frank; Kerner, Michael J.; Hayer-Hartl, Manajit; Klein, Gracjana; Georgopoulos, Costa; Landry, Samuel J.

    2004-01-01

    Molecular machines order and disorder polypeptides as they form and dissolve large intermolecular interfaces, but the biological significance of coupled ordering and binding has been established in few, if any, macromolecular systems. The ordering and binding of GroES co-chaperonin mobile loops accompany an ATP-dependent conformational change in the GroEL chaperonin that promotes client protein folding. Following ATP hydrolysis, disordering of the mobile loops accompanies co-chaperonin dissociation, reversal of the GroEL conformational change, and release of the client protein. “High-affinity” GroEL mutants were identified by their compatibility with “low-affinity” co-chaperonin mutants and incompatibility with high-affinity co-chaperonin mutants. Analysis of binding kinetics using the intrinsic fluorescence of tryptophan-containing co-chaperonin variants revealed that excessive affinity causes the chaperonin to stall in a conformation that forms in the presence of ATP. Destabilizing the β-hairpins formed by the mobile loops restores the normal rate of dissociation. Thus, the free energy of mobile-loop ordering and disordering acts like the inertia of an engine’s flywheel by modulating the speed of chaperonin conformational changes. PMID:15238634

  13. An information theoretic framework reveals a tunable allosteric network in group II chaperonins.

    PubMed

    Lopez, Tom; Dalton, Kevin; Tomlinson, Anthony; Pande, Vijay; Frydman, Judith

    2017-09-01

    ATP-dependent allosteric regulation of the ring-shaped group II chaperonins remains ill defined, in part because their complex oligomeric topology has limited the success of structural techniques in suggesting allosteric determinants. Further, their high sequence conservation has hindered the prediction of allosteric networks using mathematical covariation approaches. Here, we develop an information theoretic strategy that is robust to residue conservation and apply it to group II chaperonins. We identify a contiguous network of covarying residues that connects all nucleotide-binding pockets within each chaperonin ring. An interfacial residue between the networks of neighboring subunits controls positive cooperativity by communicating nucleotide occupancy within each ring. Strikingly, chaperonin allostery is tunable through single mutations at this position. Naturally occurring variants at this position that double the extent of positive cooperativity are less prevalent in nature. We propose that being less cooperative than attainable allows chaperonins to support robust folding over a wider range of metabolic conditions.

  14. Mechanism of lid closure in the eukaryotic chaperonin TRiC/CCT.

    PubMed

    Booth, Christopher R; Meyer, Anne S; Cong, Yao; Topf, Maya; Sali, Andrej; Ludtke, Steven J; Chiu, Wah; Frydman, Judith

    2008-07-01

    All chaperonins mediate ATP-dependent polypeptide folding by confining substrates within a central chamber. Intriguingly, the eukaryotic chaperonin TRiC (also called CCT) uses a built-in lid to close the chamber, whereas prokaryotic chaperonins use a detachable lid. Here we determine the mechanism of lid closure in TRiC using single-particle cryo-EM and comparative protein modeling. Comparison of TRiC in its open, nucleotide-free, and closed, nucleotide-induced states reveals that the interdomain motions leading to lid closure in TRiC are radically different from those of prokaryotic chaperonins, despite their overall structural similarity. We propose that domain movements in TRiC are coordinated through unique interdomain contacts within each subunit and, further, these contacts are absent in prokaryotic chaperonins. Our findings show how different mechanical switches can evolve from a common structural framework through modification of allosteric networks.

  15. Chaperonin filaments: their formation and an evaluation of methods for studying them.

    PubMed

    Yaoi, T; Kagawa, H K; Trent, J D

    1998-08-01

    Chaperonins are multisubunit protein complexes that can be isolated from cells as high-molecular-weight structures that appear as double rings in the electron microscope. We recently discovered that chaperonin double rings isolated from the hyperthermophilic archaeon Sulfolobus shibatae, when incubated at physiological temperatures in the presence of ATP and Mg2+, stacked into filaments; we hypothesized that these filaments are related to filaments seen inside S. shibatae cells and that chaperonins exist as filaments in vivo (J. D. Trent et al., 1997, Proc. Natl. Acad. Sci. USA 94, 5383-5388). This paper elucidates the conditions under which we have observed S. shibatae chaperonins to form filaments and evaluates native polyacrylamide gel electrophoresis (PAGE), TEM, spectrophotometry, and centrifugation as methods for studying these filaments. We observed that in the presence of Mg2+ combined with ATP, ADP, ATPgammaS, or GTP, native PAGE indicated that chaperonin subunits assembled into double rings and that the conformation of these double rings was effected by nucleotide binding, but we saw no indication of chaperonin filament formation. Under these same conditions, however, TEM, spectroscopy, and centrifugation methods indicated that chaperonin subunits and double rings had assembled into filaments. We determined that this discrepancy in the representation of the chaperonin structure was due to the native PAGE method itself. When we exposed chaperonin filaments to the electrophoretic field used in native PAGE, the filaments dissociated into double rings. This suggests that TEM, spectrophotometry, and centrifugation are the preferred methods for studying the higher-order structures of chaperonins, which are likely to be of biological significance. Copyright 1998 Academic Press.

  16. Comparative cell signalling activity of ultrapure recombinant chaperonin 60 proteins from prokaryotes and eukaryotes.

    PubMed

    Maguire, Maria; Poole, Stephen; Coates, Anthony R M; Tormay, Peter; Wheeler-Jones, Caroline; Henderson, Brian

    2005-06-01

    Heat-shock protein (hsp)60/chaperonin 60 is a potent immunogen which has recently been claimed to have cell-signalling actions upon myeloid and vascular endothelial cells. The literature is controversial with different chaperonin 60 proteins producing different patterns of cellular activation and the ever-present criticism that activity is the result of bacterial contaminants. To clarify the situation we have cloned, expressed and purified to homogeneity the chaperonin 60 proteins from Chlamydia pneumoniae, Helicobacter pylori and the human mitochondrion. These highly purified proteins were compared for their ability to stimulate human peripheral blood mononuclear cell (PBMC) cytokine synthesis and vascular endothelial cell adhesion protein expression. In spite of their significant sequence homology, the H. pylori protein was the most potent PBMC activator with the human protein the least potent. PBMC activation by C. pneumoniae and human, but not H. pylori, chaperonin 60 was blocked by antibody neutralization of Toll-like receptor-4. The C. pneumoniae chaperonin 60 was the most potent endothelial cell activator, with the human protein being significantly less active than bacterial chaperonin 60 proteins. These results have implications for the role of chaperonin 60 proteins as pathological factors in autoimmune and cardiovascular disease, and raise the possibility that each of these proteins may result in different pathological effects in such diseases.

  17. Crystal Structure of the 65-Kilodalton Heat Shock Protein, Chaperonin 60.2, of Mycobacterium tuberculosis

    PubMed Central

    Qamra, Rohini; Mande, Shekhar C.

    2004-01-01

    Chaperonin 60s are a ubiquitous class of proteins that promote folding and assembly of other cellular polypeptides in an ATP-dependent manner. The oligomeric state of chaperonin 60s has been shown to be crucial to their role as molecular chaperones. Chaperonin 60s are also known to be important stimulators of the immune system. Mycobacterium tuberculosis possesses a duplicate set of chaperonin 60s, both of which have been shown to be potent cytokine stimulators. The M. tuberculosis chaperonin 60s are present in the extracellular milieu at concentrations that are extremely low for the formation of an oligomer. Here we present the crystal structure of one of the chaperonin 60s of M. tuberculosis, also called Hsp65 or chaperonin 60.2, at 3.2-Å resolution. We were able to crystallize the protein in its dimeric state. The unusual dimerization of the protein leads to exposure of certain hydrophobic patches on the surface of the protein, and we hypothesize that this might have relevance in binding to immunogenic peptides, as it does in the eukaryotic homologs. PMID:15547284

  18. Thermolabile folding intermediates: inclusion body precursors and chaperonin substrates

    PubMed Central

    KING, JONATHAN; HAASE-PETTINGELL, CAMERON; ROBINSON, ANNE SKAJA; SPEED, MARGARET; MITRAKI, ANNA

    2007-01-01

    An unexpected aspect of the expression of cloned genes is the frequent failure of newly synthesized polypeptide chains to reach their native state, accumulating instead as insoluble inclusion bodies. Amyloid deposits represent a related state associated with a variety of human diseases. The critical folding intermediates at the juncture of productive folding and the off-pathway aggregation reaction have been identified for the phage P22 tailspike and coat proteins. Though the parallel β coil tailspike is thermostable, an early intracellular folding intermediate is thermolabile. As the temperature of intracellular folding is increased, this species partitions to inclusion bodies, a kinetic trap within the cell. The earliest intermediates along the in vitro aggregation pathway, sequential multimers of the thermolabile folding intermediates, have been directly identified by native gel electrophoresis. Temperature-sensitive folding (tsf) mutations identify sites in the β coil domain, which direct the junctional intermediate down the productive pathway. Global suppressors of tsf mutants inhibit the pathway to inclusion bodies, rescuing the mutant chains. These mutants identify sites important for avoiding aggregation. Coat folding intermediates also partition to inclusion bodies as temperature is increased. Coat tsf mutants are suppressed by overexpression of the GroE chaperonin, indicating that the thermolabile intermediate is a physiological substrate for GroE. We suggest that many proteins are likely to have thermolabile intermediates in their intracellular folding pathways, which will be precursors to inclusion body formation at elevated temperatures and therefore substrates for heat shock chaperonins. PMID:8566549

  19. Ring Separation Highlights the Protein-Folding Mechanism Used by the Phage EL-Encoded Chaperonin.

    PubMed

    Molugu, Sudheer K; Hildenbrand, Zacariah L; Morgan, David Gene; Sherman, Michael B; He, Lilin; Georgopoulos, Costa; Sernova, Natalia V; Kurochkina, Lidia P; Mesyanzhinov, Vadim V; Miroshnikov, Konstantin A; Bernal, Ricardo A

    2016-04-05

    Chaperonins are ubiquitous, ATP-dependent protein-folding molecular machines that are essential for all forms of life. Bacteriophage φEL encodes its own chaperonin to presumably fold exceedingly large viral proteins via profoundly different nucleotide-binding conformations. Our structural investigations indicate that ATP likely binds to both rings simultaneously and that a misfolded substrate acts as the trigger for ATP hydrolysis. More importantly, the φEL complex dissociates into two single rings resulting from an evolutionarily altered residue in the highly conserved ATP-binding pocket. Conformational changes also more than double the volume of the single-ring internal chamber such that larger viral proteins are accommodated. This is illustrated by the fact that φEL is capable of folding β-galactosidase, a 116-kDa protein. Collectively, the architecture and protein-folding mechanism of the φEL chaperonin are significantly different from those observed in group I and II chaperonins.

  20. Expression and Functional Characterization of the First Bacteriophage-Encoded Chaperonin

    PubMed Central

    Semenyuk, Pavel I.; Orlov, Victor N.; Robben, Johan; Sykilinda, Nina N.; Mesyanzhinov, Vadim V.

    2012-01-01

    Chaperonins promote protein folding in vivo and are ubiquitously found in bacteria, archaea, and eukaryotes. The first viral chaperonin GroEL ortholog, gene product 146 (gp146), whose gene was earlier identified in the genome of bacteriophage EL, has been shown to be synthesized during phage propagation in Pseudomonas aeruginosa cells. The recombinant gp146 has been expressed in Escherichia coli and characterized by different physicochemical methods for the first time. Using serum against the recombinant protein, gp146's native substrate, the phage endolysin gp188, has been immunoprecipitated from the lysate of EL-infected bacteria and identified by mass spectrometry. In vitro experiments have shown that gp146 has a protective effect against endolysin thermal inactivation and aggregation, providing evidence of its chaperonin function. The phage chaperonin has been found to have the architecture and some properties similar to those of GroEL but not to require cochaperonin for its functional activity. PMID:22787217

  1. An intrinsically fluorescent recognition ligand scaffold based on chaperonin protein and semiconductor quantum-dot conjugates.

    PubMed

    Xie, Hongzhi; Li, Yi-Fen; Kagawa, Hiromi K; Trent, Jonathan D; Mudalige, Kumara; Cotlet, Mircea; Swanson, Basil I

    2009-05-01

    Genetic engineering of a novel protein-nanoparticle hybrid system with great potential for biosensing applications and for patterning of various types of nanoparticles is described. The hybrid system is based on a genetically modified chaperonin protein from the hyperthermophilic archaeon Sulfolobus shibatae. This chaperonin is an 18-subunit double ring, which self-assembles in the presence of Mg ions and ATP. Described here is a mutant chaperonin (His-beta-loopless, HBLL) with increased access to the central cavity and His-tags on each subunit extending into the central cavity. This mutant binds water-soluble semiconductor quantum dots, creating a protein-encapsulated fluorescent nanoparticle. The new bioconjugate has high affinity, in the order of strong antibody-antigen interactions, a one-to-one protein-nanoparticle stoichiometry, and high stability. By adding selective binding sites to the solvent-exposed regions of the chaperonin, this protein-nanoparticle bioconjugate becomes a sensor for specific targets.

  2. In silico engineering of aggregation-prone recombinant proteins for substrate recognition by the chaperonin GroEL

    PubMed Central

    2012-01-01

    Background Molecular chaperones appear to have been evolved to facilitate protein folding in the cell through entrapment of folding intermediates on the interior of a large cavity formed between GroEL and its co-chaperonin GroES. They bind newly synthesized or non-native polypeptides through hydrophobic interactions and prevent their aggregation. Some proteins do not interact with GroEL, hence even though they are aggregation prone, cannot be assisted by GroEL for their folding. Results In this study, we have attempted to engineer these non-substrate proteins to convert them as the substrate for GroEL, without compromising on their function. We have used a computational biology approach to generate mutants of the selected proteins by selectively mutating residues in the hydrophobic patch, similar to GroES mobile loop region that are responsible for interaction with GroEL, and compared with the wild counterparts for calculation of their instability and aggregation propensities. The energies of the newly designed mutants were computed through molecular dynamics simulations. We observed increased aggregation propensity of some of the mutants formed after replacing charged amino acid residues with hydrophobic ones in the well defined hydrophobic patch, raising the possibility of their binding ability to GroEL. Conclusions The newly generated mutants may provide potential substrates for Chaperonin GroEL, which can be experimentally generated and tested for their tendency of aggregation, interactions with GroEL and the possibility of chaperone-assisted folding to produce functional proteins. PMID:23281895

  3. The chaperonin CCT8 facilitates spread of tobamovirus infection.

    PubMed

    Fichtenbauer, Daniela; Xu, Xianfeng Morgan; Jackson, Dave; Kragler, Friedrich

    2012-03-01

    The homeodomain transcription factor KNOTTED1 (KN1) functions in shoot meristem maintenance and is thought to move from cell to cell in a similar fashion as viral movement proteins. Both types of transported proteins bind to RNA, and associate with intercellular bridges formed by plasmodesmata. In a mutant screen for KN1 transport deficiency, a component of a type II chaperonin complex, CCT8, was identified, and found to interact with non-cell-autonomous proteins. The cct8 mutants are characterized by limited functionality of non-cell-autonomous proteins after their movement, and a phenotype resembling lack of homeodomain protein activity. Evidence suggests that CCT8 functions in post-translocational refolding of transported proteins. Here we show that spread of tobamovirus infection is reduced in a cct8 mutant. This suggests that similar to KN1, viral movement proteins are unfolded and refolded during transport to gain functionality in the receiving cells.

  4. Overexpressed ribosomal proteins suppress defective chaperonins in Saccharomyces cerevisiae.

    PubMed

    Kabir, M Anaul; Sherman, Fred

    2008-12-01

    The chaperonin Cct complex of the yeast Saccharomyces cerevisiae is composed of eight different subunits encoded by eight essential genes, CCT1-CCT8. This Cct complex is responsible for the folding of a number of proteins including actin and tubulin. We have isolated and characterized 22 multicopy suppressors of the temperature-sensitive allele, cct4-1, which encodes an altered protein with a G345D replacement that diminishes ATP hydrolysis. Fourteen of the suppressors encode ribosomal proteins, four have roles in ribosome biogenesis, two have phosphatase activities, one is involved in protein synthesis and one of the suppressors corresponded to Cct4p. Some of the suppressors also acted on certain cct1, cct2, cct3 and cct6 mutations. We suggest that certain overexpressed ribosomal and other proteins can act as weak chaperones, phenotypically alleviating the partial defects of mutationally altered Cct subunits.

  5. Role of CCT chaperonin in the disassembly of mitotic checkpoint complexes.

    PubMed

    Kaisari, Sharon; Sitry-Shevah, Danielle; Miniowitz-Shemtov, Shirly; Teichner, Adar; Hershko, Avram

    2017-01-31

    The mitotic checkpoint system prevents premature separation of sister chromatids in mitosis and thus ensures the fidelity of chromosome segregation. When this checkpoint is active, a mitotic checkpoint complex (MCC), composed of the checkpoint proteins Mad2, BubR1, Bub3, and Cdc20, is assembled. MCC inhibits the ubiquitin ligase anaphase promoting complex/cyclosome (APC/C), whose action is necessary for anaphase initiation. When the checkpoint signal is turned off, MCC is disassembled, a process required for exit from checkpoint-arrested state. Different moieties of MCC are disassembled by different ATP-requiring processes. Previous work showed that Mad2 is released from MCC by the joint action of the TRIP13 AAA-ATPase and the Mad2-binding protein p31(comet) Now we have isolated from extracts of HeLa cells an ATP-dependent factor that releases Cdc20 from MCC and identified it as chaperonin containing TCP1 or TCP1-Ring complex (CCT/TRiC chaperonin), a complex known to function in protein folding. Bacterially expressed CCT5 chaperonin subunits, which form biologically active homooligomers [Sergeeva, et al. (2013) J Biol Chem 288(24):17734-17744], also promote the disassembly of MCC. CCT chaperonin further binds and disassembles subcomplexes of MCC that lack Mad2. Thus, the combined action of CCT chaperonin with that of TRIP13 ATPase promotes the complete disassembly of MCC, necessary for the inactivation of the mitotic checkpoint.

  6. Chaperonins fight aminoglycoside-induced protein misfolding and promote short-term tolerance in Escherichia coli.

    PubMed

    Goltermann, Lise; Good, Liam; Bentin, Thomas

    2013-04-12

    For almost half of a century, we have known that aminoglycoside antibiotics corrupt ribosomes, causing translational misreading, yet it remains unclear whether or not misreading triggers protein misfolding, and possible effects of chaperone action on drug susceptibilities are poorly understood. Here, we show that aminoglycosides cause cytosolic protein misfolding and that chaperonin GroEL/GroES overexpression counters this defect. During aminoglycoside exposure to exponential cultures, chaperonin overexpression protected the bacterial membrane potential, rescued cell growth, and facilitated survival, whereas inhibition of chaperonin expression sensitized bacteria. Overexpression of the DnaK/DnaJ/GrpE chaperone system similarly facilitated survival but did not promote growth of aminoglycoside-treated bacteria. Inhibition of chaperonin expression sensitized bacteria to aminoglycosides as measured by reduced minimum inhibitory concentrations, whereas GroEL/GroES overexpression did not increase minimum inhibitory concentrations. Our observations establish misfolding of cytosolic proteins as an effect of aminoglycoside action and reveal that chaperones, chaperonins in particular, help bacteria cope during early exposure to these drugs.

  7. ATP Dependent Rotational Motion of Group II Chaperonin Observed by X-ray Single Molecule Tracking

    PubMed Central

    Sekiguchi, Hiroshi; Nakagawa, Ayumi; Moriya, Kazuki; Makabe, Koki; Ichiyanagi, Kouhei; Nozawa, Shunsuke; Sato, Tokushi; Adachi, Shin-ichi; Kuwajima, Kunihiro; Yohda, Masafumi; Sasaki, Yuji C.

    2013-01-01

    Group II chaperonins play important roles in protein homeostasis in the eukaryotic cytosol and in Archaea. These proteins assist in the folding of nascent polypeptides and also refold unfolded proteins in an ATP-dependent manner. Chaperonin-mediated protein folding is dependent on the closure and opening of a built-in lid, which is controlled by the ATP hydrolysis cycle. Recent structural studies suggest that the ring structure of the chaperonin twists to seal off the central cavity. In this study, we demonstrate ATP-dependent dynamics of a group II chaperonin at the single-molecule level with highly accurate rotational axes views by diffracted X-ray tracking (DXT). A UV light-triggered DXT study with caged-ATP and stopped-flow fluorometry revealed that the lid partially closed within 1 s of ATP binding, the closed ring subsequently twisted counterclockwise within 2–6 s, as viewed from the top to bottom of the chaperonin, and the twisted ring reverted to the original open-state with a clockwise motion. Our analyses clearly demonstrate that the biphasic lid-closure process occurs with unsynchronized closure and a synchronized counterclockwise twisting motion. PMID:23734192

  8. Arabidopsis chloroplast chaperonin 10 is a calmodulin-binding protein

    NASA Technical Reports Server (NTRS)

    Yang, T.; Poovaiah, B. W.

    2000-01-01

    Calcium regulates diverse cellular activities in plants through the action of calmodulin (CaM). By using (35)S-labeled CaM to screen an Arabidopsis seedling cDNA expression library, a cDNA designated as AtCh-CPN10 (Arabidopsis thaliana chloroplast chaperonin 10) was cloned. Chloroplast CPN10, a nuclear-encoded protein, is a functional homolog of E. coli GroES. It is believed that CPN60 and CPN10 are involved in the assembly of Rubisco, a key enzyme involved in the photosynthetic pathway. Northern analysis revealed that AtCh-CPN10 is highly expressed in green tissues. The recombinant AtCh-CPN10 binds to CaM in a calcium-dependent manner. Deletion mutants revealed that there is only one CaM-binding site in the last 31 amino acids of the AtCh-CPN10 at the C-terminal end. The CaM-binding region in AtCh-CPN10 has higher homology to other chloroplast CPN10s in comparison to GroES and mitochondrial CPN10s, suggesting that CaM may only bind to chloroplast CPN10s. Furthermore, the results also suggest that the calcium/CaM messenger system is involved in regulating Rubisco assembly in the chloroplast, thereby influencing photosynthesis. Copyright 2000 Academic Press.

  9. Arabidopsis chloroplast chaperonin 10 is a calmodulin-binding protein

    NASA Technical Reports Server (NTRS)

    Yang, T.; Poovaiah, B. W.

    2000-01-01

    Calcium regulates diverse cellular activities in plants through the action of calmodulin (CaM). By using (35)S-labeled CaM to screen an Arabidopsis seedling cDNA expression library, a cDNA designated as AtCh-CPN10 (Arabidopsis thaliana chloroplast chaperonin 10) was cloned. Chloroplast CPN10, a nuclear-encoded protein, is a functional homolog of E. coli GroES. It is believed that CPN60 and CPN10 are involved in the assembly of Rubisco, a key enzyme involved in the photosynthetic pathway. Northern analysis revealed that AtCh-CPN10 is highly expressed in green tissues. The recombinant AtCh-CPN10 binds to CaM in a calcium-dependent manner. Deletion mutants revealed that there is only one CaM-binding site in the last 31 amino acids of the AtCh-CPN10 at the C-terminal end. The CaM-binding region in AtCh-CPN10 has higher homology to other chloroplast CPN10s in comparison to GroES and mitochondrial CPN10s, suggesting that CaM may only bind to chloroplast CPN10s. Furthermore, the results also suggest that the calcium/CaM messenger system is involved in regulating Rubisco assembly in the chloroplast, thereby influencing photosynthesis. Copyright 2000 Academic Press.

  10. Compromised wounds in Canada.

    PubMed

    Denny, Keith; Lawand, Christina; Perry, Sheril D

    2014-01-01

    Wounds are a serious healthcare issue with profound personal, clinical and economic implications. Using a working definition of compromised wounds, this study examines the prevalence of wounds by type and by healthcare setting using data from hospitals, home care, hospital-based continuing care and long-term care facilities within fiscal year 2011-2012 in Canada. It also evaluates several risk factors associated with wounds, such as diabetes, circulatory disease and age. Compromised wounds were reported in almost 4% of in-patient acute hospitalizations and in more than 7% of home care clients, almost 10% of long-term care clients and almost 30% of hospital-based continuing care clients. Patients with diabetes were much more likely to have a compromised wound than were patients without the disease. Copyright © 2014 Longwoods Publishing.

  11. Single-molecule spectroscopy of protein folding in a chaperonin cage

    PubMed Central

    Hofmann, Hagen; Hillger, Frank; Pfeil, Shawn H.; Hoffmann, Armin; Streich, Daniel; Haenni, Dominik; Nettels, Daniel; Lipman, Everett A.; Schuler, Benjamin

    2010-01-01

    Molecular chaperones are known to be essential for avoiding protein aggregation in vivo, but it is still unclear how they affect protein folding mechanisms. We use single-molecule Förster resonance energy transfer to follow the folding of a protein inside the GroEL/GroES chaperonin cavity over a time range from milliseconds to hours. Our results show that confinement in the chaperonin decelerates the folding of the C-terminal domain in the substrate protein rhodanese, but leaves the folding rate of the N-terminal domain unaffected. Microfluidic mixing experiments indicate that strong interactions of the substrate with the cavity walls impede the folding process, but the folding hierarchy is preserved. Our results imply that no universal chaperonin mechanism exists. Rather, a competition between intra- and intermolecular interactions determines the folding rates and mechanisms of a substrate inside the GroEL/GroES cage. PMID:20547872

  12. Origin and evolution of eukaryotic chaperonins: phylogenetic evidence for ancient duplications in CCT genes.

    PubMed

    Archibald, J M; Logsdon, J M; Doolittle, W F

    2000-10-01

    Chaperonins are oligomeric protein-folding complexes which are divided into two distantly related structural classes. Group I chaperonins (called GroEL/cpn60/hsp60) are found in bacteria and eukaryotic organelles, while group II chaperonins are present in archaea and the cytoplasm of eukaryotes (called CCT/TriC). While archaea possess one to three chaperonin subunit-encoding genes, eight distinct CCT gene families (paralogs) have been characterized in eukaryotes. We are interested in determining when during eukaryotic evolution the multiple gene duplications producing the CCT subunits occurred. We describe the sequence and phylogenetic analysis of five CCT genes from TRICHOMONAS: vaginalis and seven from GIARDIA: lamblia, representatives of amitochondriate protist lineages thought to have diverged early from other eukaryotes. Our data show that the gene duplications producing the eight CCT paralogs took place prior to the organismal divergence of TRICHOMONAS: and GIARDIA: from other eukaryotes. Thus, these divergent protists likely possess completely hetero-oligomeric CCT complexes like those in yeast and mammalian cells. No close phylogenetic relationship between the archaeal chaperonins and specific CCT subunits was observed, suggesting that none of the CCT gene duplications predate the divergence of archaea and eukaryotes. The duplications producing the CCTdelta and CCTepsilon subunits, as well as CCTalpha, CCTbeta, and CCTeta, are the most recent in the CCT gene family. Our analyses show significant differences in the rates of evolution of archaeal chaperonins compared with the eukaryotic CCTs, as well as among the different CCT subunits themselves. We discuss these results in light of current views on the origin, evolution, and function of CCT complexes.

  13. Isolation and characterization of a Paracentrotus lividus cDNA encoding a stress-inducible chaperonin

    PubMed Central

    Gianguzza, Fabrizio; Antonietta Ragusa, Maria; Roccheri, Maria Carmela; Liegro, Italia Di; Rinaldi, Anna Maria

    2000-01-01

    Chaperonins are ubiquitous proteins that facilitate protein folding in an adenosine triphosphate–dependent manner. Here we report the isolation of a sea urchin cDNA (Plhsp60) coding for mitochondrial chaperonin (Cpn60), whose basal expression is further enhanced by heat shock. The described cDNA corresponds to a full-length mRNA encoding a protein of 582 amino acids, the first 32 of which constitute a putative mitochondrial targeting leader sequence. Comparative analysis has demonstrated that this protein is highly conserved in evolution. PMID:11147969

  14. P. falciparum cpn20 Is a Bona Fide Co-Chaperonin That Can Replace GroES in E. coli

    PubMed Central

    Vitlin Gruber, Anna; Nisemblat, Shahar; Zizelski, Gal; Parnas, Avital; Dzikowski, Ron; Azem, Abdussalam; Weiss, Celeste

    2013-01-01

    Human malaria is among the most ubiquitous and destructive tropical, parasitic diseases in the world today. The causative agent, Plasmodium falciparum, contains an unusual, essential organelle known as the apicoplast. Inhibition of this degenerate chloroplast results in second generation death of the parasite and is the mechanism by which antibiotics function in treating malaria. In order to better understand the biochemistry of this organelle, we have cloned a putative, 20 kDa, co-chaperonin protein, Pf-cpn20, which localizes to the apicoplast. Although this protein is homologous to the cpn20 that is found in plant chloroplasts, its ability to function as a co-chaperonin was questioned in the past. In the present study, we carried out a structural analysis of Pf-cpn20 using circular dichroism and analytical ultracentrifugation and then used two different approaches to investigate the ability of this protein to function as a co-chaperonin. In the first approach, we purified recombinant Pf-cpn20 and tested its ability to act as a co-chaperonin for GroEL in vitro, while in the second, we examined the ability of Pf-cpn20 to complement an E. coli depletion of the essential bacterial co-chaperonin GroES. Our results demonstrate that Pf-cpn20 is fully functional as a co-chaperonin in vitro. Moreover, the parasitic co-chaperonin is able to replace GroES in E. coli at both normal and heat-shock temperatures. Thus, Pf-cpn20 functions as a co-chaperonin in chaperonin-mediated protein folding. The ability of the malarial protein to function in E. coli suggests that this simple system can be used as a tool for further analyses of Pf-cpn20 and perhaps other chaperone proteins from P. falciparum. PMID:23326533

  15. Three conformations of an Archaeal chaperonin, TF55 from Sulfolobus shibatae.

    SciTech Connect

    Schoehn, G.; Quaite-Randall, E.; Joachimiak, A.; Saibil, H. R.; Biosciences Division; Birkbeck Coll.

    2000-02-25

    Chaperonins are cylindrical, oligomeric complexes, essential for viability and required for the folding of other proteins. The GroE (group I) subfamily, found in eubacteria, mitochondria and chloroplasts, have 7-fold symmetry and provide an enclosed chamber for protein subunit folding. The central cavity is transiently closed by interaction with the co-protein, GroES. The most prominent feature specific to the group II subfamily, found in archaea and in the eukaryotic cytosol, is a long insertion in the substrate-binding region. In the archaeal complex, this forms an extended structure acting as a built-in lid, obviating the need for a GroES-like co-factor. This extension occludes a site known to bind non-native polypeptides in GroEL. The site and nature of substrate interaction are not known for the group II subfamily. The atomic structure of the thermosome, an archaeal group II chaperonin, has been determined in a fully closed form, but the entry and exit of protein substrates requires transient opening. Although an open form has been investigated by electron microscopy, conformational changes in group II chaperonins are not well characterized. Using electron cryo-microscopy and three-dimensional reconstruction, we describe three conformations of a group II chaperonin, including an asymmetric, bullet-shaped form, revealing the range of domain movements in this subfamily.

  16. Reversible denaturation of oligomeric human chaperonin 10: denatured state depends on chemical denaturant.

    PubMed Central

    Guidry, J. J.; Moczygemba, C. K.; Steede, N. K.; Landry, S. J.; Wittung-Stafshede, P.

    2000-01-01

    Chaperonins cpn60/cpn10 (GroEL/GroES in Escherichia coli) assist folding of nonnative polypeptides. Folding of the chaperonins themselves is distinct in that it entails assembly of a sevenfold symmetrical structure. We have characterized denaturation and renaturation of the recombinant human chaperonin 10 (cpn10), which forms a heptamer. Denaturation induced by chemical denaturants urea and guanidine hydrochloride (GuHCl) as well as by heat was monitored by tyrosine fluorescence, far-ultraviolet circular dichroism, and cross-linking; all denaturation reactions were reversible. GuHCl-induced denaturation was found to be cpn10 concentration dependent, in accord with a native heptamer to denatured monomer transition. In contrast, urea-induced denaturation was not cpn10 concentration dependent, suggesting that under these conditions cpn10 heptamers denature without dissociation. There were no indications of equilibrium intermediates, such as folded monomers, in either denaturant. The different cpn10 denatured states observed in high [GuHCl] and high [urea] were supported by cross-linking experiments. Thermal denaturation revealed that monomer and heptamer reactions display the same enthalpy change (per monomer), whereas the entropy-increase is significantly larger for the heptamer. A thermodynamic cycle for oligomeric cpn10, combining chemical denaturation with the dissociation constant in absence of denaturant, shows that dissociated monomers are only marginally stable (3 kJ/mol). The thermodynamics for co-chaperonin stability appears conserved; therefore, instability of the monomer could be necessary to specify the native heptameric structure. PMID:11152122

  17. Separation of E. coli chaperonin groEL from β-galactosidase without denaturation.

    PubMed

    Molugu, Sudheer K; Li, Jihui; Bernal, Ricardo A

    2015-12-15

    Chaperonins are a class of ubiquitous proteins that assist and accelerate protein folding in the cell. The Escherichia coli groEL is the best known and forms a complex with its co-chaperonin groES in the presence of ATP and assists in the folding of nascent and misfolded substrate proteins. The purification of recombinant groEL results in a nearly homogeneous sample that consistently co-purifies with the major contaminant E. coli β-galactosidase. Removal of β-galactosidase using column chromatography alone is exceedingly difficult. This is due to the fact that the overall size, surface charge, isoelectric point and hydrophobicity of groEL and β-galactosidase are very similar. Therefore purification of groEL chaperonin to homogeneity requires denaturation of the complex into monomers with urea for separating the groEL from contaminating β-galactosidase followed by reassembly of the chaperonin complex. Here, we present a simple procedure for separating β-galactosidase along with many other impurities from groEL preparations under non-denaturing conditions. The groEL is first salted out with 50% ammonium sulfate. This step also precipitates β-galactosidase but this is then salted out by the addition of magnesium chloride which leaves groEL in solution. All remaining contaminants are removed by column chromatography.

  18. Chaperonin-enhanced Escherichia coli cell-free expression of functional CXCR4.

    PubMed

    Chi, Haixia; Wang, Xiaoqiang; Li, Jiqiang; Ren, Hao; Huang, Fang

    2016-08-10

    G protein-coupled receptors (GPCRs) are important therapeutic targets for a broad spectrum of diseases and disorders. Obtaining milligram quantities of functional receptors through the development of robust production methods are highly demanded to probe GPCR structure and functions. In this study, we analyzed synergies of the bacterial chaperonin GroEL-GroES and cell-free expression for the production of functionally folded C-X-C chemokine GPCR type 4 (CXCR4). The yield of soluble CXCR4 in the presence of detergent Brij-35 reached ∼1.1mg/ml. The chaperonin complex added was found to significantly enhance the productive folding of newly synthesized CXCR4, by increasing both the rate (∼30-fold) and the yield (∼1.3-fold) of folding over its spontaneous behavior. Meanwhile, the structural stability of CXCR4 was also improved with supplied GroEL-GroES, as was the soluble expression of biologically active CXCR4 with a ∼1.4-fold increase. The improved stability together with the higher ligand binding affinity suggests more efficient folding. The essential chaperonin GroEL was shown to be partially effective on its own, but for maximum efficiency both GroEL and its co-chaperonin GroES were necessary. The method reported here should prove generally useful for cell-free production of large amounts of natively folded GPCRs, and even other classes of membrane proteins.

  19. Streptococcus iniae, a Human and Animal Pathogen: Specific Identification by the Chaperonin 60 Gene Identification Method

    PubMed Central

    Goh, Swee Han; Driedger, David; Gillett, Sandra; Low, Donald E.; Hemmingsen, Sean M.; Amos, Mayben; Chan, David; Lovgren, Marguerite; Willey, Barbara M.; Shaw, Carol; Smith, John A.

    1998-01-01

    It was recently reported that Streptococcus iniae, a bacterial pathogen of aquatic animals, can cause serious disease in humans. Using the chaperonin 60 (Cpn60) gene identification method with reverse checkerboard hybridization and chemiluminescent detection, we identified correctly each of 12 S. iniae samples among 34 aerobic gram-positive isolates from animal and clinical human sources. PMID:9650992

  20. Prokaryotic Chaperonins as Experimental Models for Elucidating Structure-Function Abnormalities of Human Pathogenic Mutant Counterparts

    PubMed Central

    Conway de Macario, Everly; Robb, Frank T.; Macario, Alberto J. L.

    2017-01-01

    All archaea have a chaperonin of Group II (thermosome) in their cytoplasm and some have also a chaperonin of Group I (GroEL; Cpn60; Hsp60). Conversely, all bacteria have GroEL, some in various copies, but only a few have, in addition, a chaperonin (tentatively designated Group III chaperonin) very similar to that occurring in all archaea, i.e., the thermosome subunit, and in the cytosol of eukaryotic cells, named CCT. Thus, nature offers a range of prokaryotic organisms that are potentially useful as experimental models to study the human CCT and its abnormalities. This is important because many diseases, the chaperonopathies, have been identified in which abnormal chaperones, including mutant CCT, are determinant etiologic-pathogenic factors and, therefore, research is needed to elucidate their pathologic features at the molecular level. Such research should lead to the clarification of the molecular mechanisms underlying the pathologic lesions observed in the tissues and organs of patients with chaperonopathies. Information on these key issues is necessary to make progress in diagnosis and treatment. Some of the archaeal organisms as well as some of the bacterial models suitable for studying molecular aspects pertinent to human mutant chaperones are discussed here, focusing on CCT. Results obtained with the archaeon Pyrococcus furiosus model to investigate the impact of a pathogenic CCT5 mutation on molecular properties and chaperoning functions are reviewed. The pathogenic mutation examined weakens the ability of the chaperonin subunit to form stable hexadecamers and as a consequence, the chaperoning functions of the complex are impaired. The future prospect is to find means for stabilizing the hexadecamer, which should lead to a recovering of chaperone function and the improving of lesions and clinical condition. PMID:28119916

  1. 29 CFR 18.408 - Compromise and offers to compromise.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... BEFORE THE OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Relevancy and Its Limits § 18.408 Compromise and offers to compromise. Evidence of furnishing or offering or promising to furnish, or of... for or invalidity of the claim or its amount. Evidence of conduct or statements made in compromise...

  2. On the role of the chaperonin CCT in the just-in-time assembly process of APC/CCdc20.

    PubMed

    Dekker, Carien

    2010-02-05

    The just-in-time hypothesis relates to the assembly of large multi-protein complexes and their regulation of activation in the cell. Here I postulate that chaperonins may contribute to the timely assembly and activation of such complexes. For the case of anaphase promoting complex/cyclosome(Cdc20) assembly by the eukaryotic chaperonin chaperonin containing Tcp1 it is shown that just-in-time synthesis and chaperone-assisted folding can synergise to generate a highly regulated assembly process of a protein complex that is vital for cell cycle progression. Once dependency has been established transcriptional regulation and chaperonin-dependency may have co-evolved to safeguard the timely activation of important multi-protein complexes.

  3. New GroEL-like chaperonin of bacteriophage OBP Pseudomonas fluorescens suppresses thermal protein aggregation in an ATP-dependent manner.

    PubMed

    Semenyuk, Pavel I; Orlov, Victor N; Sokolova, Olga S; Kurochkina, Lidia P

    2016-08-01

    Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudomonas aeruginosa, gene product (gp) 146. In the present study, we performed bioinformatics analysis of currently predicted GroEL-like proteins encoded by phage genomes in comparison with cellular and mitochondrial chaperonins. Putative phage chaperonins share a low similarity and do not form a monophyletic group; nevertheless, they are closer to bacterial chaperonins in the phylogenetic tree. Experimental investigation of putative GroEL-like chaperonin proteins has been continued by physicochemical and functional characterization of gp246 encoded by the genome of Pseudomonas fluorescens bacteriophage OBP. Unlike the more usual double-ring architecture of chaperonins, including the EL gp146, the recombinant gp246 produced by Escherichia coli cells has been purified as a single heptameric ring. It possesses ATPase activity and does not require a co-chaperonin for its function. In vitro experiments demonstrated that gp246 is able to suppress the thermal protein inactivation and aggregation in an ATP-dependent manner, thus indicating chaperonin function. Single-particle electron microscopy analysis revealed the different conformational states of OBP chaperonin, depending on the bound nucleotide. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  4. Circular Permutation of a Chaperonin Protein: Biophysics and Application to Nanotechnology

    NASA Technical Reports Server (NTRS)

    Paavola, Chad; Chan, Suzanne; Li, Yi-Fen; McMillan, R. Andrew; Trent, Jonathan

    2004-01-01

    We have designed five circular permutants of a chaperonin protein derived from the hyperthermophilic organism Sulfolobus shibatae. These permuted proteins were expressed in E. coli and are well-folded. Furthermore, all the permutants assemble into 18-mer double rings of the same form as the wild-type protein. We characterized the thermodynamics of folding for each permutant by both guanidine denaturation and differential scanning calorimetry. We also examined the assembly of chaperonin rings into higher order structures that may be used as nanoscale templates. The results show that circular permutation can be used to tune the thermodynamic properties of a protein template as well as facilitating the fusion of peptides, binding proteins or enzymes onto nanostructured templates.

  5. Cold adaptation of a psychrophilic chaperonin from Psychrobacter sp. and its application for heterologous protein expression.

    PubMed

    Kim, Han-Woo; Wi, Ah Ram; Jeon, Byoung Wook; Lee, Jun Hyuck; Shin, Seung Chul; Park, Hyun; Jeon, Sung-Jong

    2015-09-01

    A chaperonin, PsyGroELS, from the Antarctic psychrophilic bacterium Psychrobacter sp. PAMC21119, was examined for its role in cold adaptation when expressed in a mesophilic Escherichia coli strain. Growth of E. coli harboring PsyGroELS at 10 °C was increased compared to the control strain. A co-expression system using PsyGroELS was developed to increase productivity of the psychrophilic enzyme PsyEst9. PsyEst9 was cloned and expressed using three E. coli variants that co-expressed GroELS from PAMC21119, E. coli, or Oleispira antarctica RB8(T). Co-expression with PsyGroELS was more effective for the production of PsyEst9 compared tothe other chaperonins. PsyGroELS confers cold tolerance to E. coli, and shows potential as an effective co-expression system for the stable production of psychrophilic proteins.

  6. Circular Permutation of a Chaperonin Protein: Biophysics and Application to Nanotechnology

    NASA Technical Reports Server (NTRS)

    Paavola, Chad; Chan, Suzanne; Li, Yi-Fen; McMillan, R. Andrew; Trent, Jonathan

    2004-01-01

    We have designed five circular permutants of a chaperonin protein derived from the hyperthermophilic organism Sulfolobus shibatae. These permuted proteins were expressed in E. coli and are well-folded. Furthermore, all the permutants assemble into 18-mer double rings of the same form as the wild-type protein. We characterized the thermodynamics of folding for each permutant by both guanidine denaturation and differential scanning calorimetry. We also examined the assembly of chaperonin rings into higher order structures that may be used as nanoscale templates. The results show that circular permutation can be used to tune the thermodynamic properties of a protein template as well as facilitating the fusion of peptides, binding proteins or enzymes onto nanostructured templates.

  7. Structural and Functional Insights into the Evolution and Stress Adaptation of Type II Chaperonins.

    PubMed

    Chaston, Jessica J; Smits, Callum; Aragão, David; Wong, Andrew S W; Ahsan, Bilal; Sandin, Sara; Molugu, Sudheer K; Molugu, Sanjay K; Bernal, Ricardo A; Stock, Daniela; Stewart, Alastair G

    2016-03-01

    Chaperonins are essential biological complexes assisting protein folding in all kingdoms of life. Whereas homooligomeric bacterial GroEL binds hydrophobic substrates non-specifically, the heterooligomeric eukaryotic CCT binds specifically to distinct classes of substrates. Sulfolobales, which survive in a wide range of temperatures, have evolved three different chaperonin subunits (α, β, γ) that form three distinct complexes tailored for different substrate classes at cold, normal, and elevated temperatures. The larger octadecameric β complexes cater for substrates under heat stress, whereas smaller hexadecameric αβ complexes prevail under normal conditions. The cold-shock complex contains all three subunits, consistent with greater substrate specificity. Structural analysis using crystallography and electron microscopy reveals the geometry of these complexes and shows a novel arrangement of the α and β subunits in the hexadecamer enabling incorporation of the γ subunit. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Human chaperonin 60 (Hsp60) stimulates bone resorption: structure/function relationships.

    PubMed

    Meghji, S; Lillicrap, M; Maguire, M; Tabona, P; Gaston, J S H; Poole, S; Henderson, B

    2003-09-01

    It is established that the molecular chaperone, chaperonin 60, from various bacteria and from Homo sapiens has cell-cell signalling activity and is able to induce proinflammatory cytokine synthesis. We previously reported that chaperonin 60 proteins from Gram-negative bacteria, but not mycobacteria, have the capacity to resorb cultured murine calvarial bone. We now report that lipopolysaccharide-low human recombinant chaperonin 60 (Hsp60) is a relatively weak cytokine-inducing agonist but is a potent stimulator of murine calvarial bone resorption. The osteolytic activity of Hsp60 was significantly inhibited by indomethacin, interleukin-1 receptor antagonist, and osteoprotegerin, but 5-lipoxygenase inhibitors were less effective. Analysis of Hsp60 truncation mutants revealed that N-terminal mutants (Delta1-137, Delta1-358, and Delta1-465) retained bone resorbing activity. In contrast, a C-terminal truncation mutant (Delta1-26 + Delta466-573) was inactive. This suggests that the active domain in this protein is found within residues 466-573. It is now established that Hsp60 is present in the blood of the majority of the population with the normal range encompassing levels able to activate bone cells. The possibility exists that this protein could play a role in bone remodelling.

  9. A Versatile Platform for Nanotechnology Based on Circular Permutation of a Chaperonin Protein

    NASA Technical Reports Server (NTRS)

    Paavola, Chad; McMillan, Andrew; Trent, Jonathan; Chan, Suzanne; Mazzarella, Kellen; Li, Yi-Fen

    2004-01-01

    A number of protein complexes have been developed as nanoscale templates. These templates can be functionalized using the peptide sequences that bind inorganic materials. However, it is difficult to integrate peptides into a specific position within a protein template. Integrating intact proteins with desirable binding or catalytic activities is an even greater challenge. We present a general method for modifying protein templates using circular permutation so that additional peptide sequence can be added in a wide variety of specific locations. Circular permutation is a reordering of the polypeptide chain such that the original termini are joined and new termini are created elsewhere in the protein. New sequence can be joined to the protein termini without perturbing the protein structure and with minimal limitation on the size and conformation of the added sequence. We have used this approach to modify a chaperonin protein template, placing termini at five different locations distributed across the surface of the protein complex. These permutants are competent to form the double-ring structures typical of chaperonin proteins. The permuted double-rings also form the same assemblies as the unmodified protein. We fused a fluorescent protein to two representative permutants and demonstrated that it assumes its active structure and does not interfere with assembly of chaperonin double-rings.

  10. A Versatile Platform for Nanotechnology Based on Circular Permutation of a Chaperonin Protein

    NASA Technical Reports Server (NTRS)

    Paavola, Chad; McMillan, Andrew; Trent, Jonathan; Chan, Suzanne; Mazzarella, Kellen; Li, Yi-Fen

    2004-01-01

    A number of protein complexes have been developed as nanoscale templates. These templates can be functionalized using the peptide sequences that bind inorganic materials. However, it is difficult to integrate peptides into a specific position within a protein template. Integrating intact proteins with desirable binding or catalytic activities is an even greater challenge. We present a general method for modifying protein templates using circular permutation so that additional peptide sequence can be added in a wide variety of specific locations. Circular permutation is a reordering of the polypeptide chain such that the original termini are joined and new termini are created elsewhere in the protein. New sequence can be joined to the protein termini without perturbing the protein structure and with minimal limitation on the size and conformation of the added sequence. We have used this approach to modify a chaperonin protein template, placing termini at five different locations distributed across the surface of the protein complex. These permutants are competent to form the double-ring structures typical of chaperonin proteins. The permuted double-rings also form the same assemblies as the unmodified protein. We fused a fluorescent protein to two representative permutants and demonstrated that it assumes its active structure and does not interfere with assembly of chaperonin double-rings.

  11. Cryo-EM structure of a group II chaperonin in the prehydrolysis ATP-bound state leading to lid closure.

    PubMed

    Zhang, Junjie; Ma, Boxue; DiMaio, Frank; Douglas, Nicholai R; Joachimiak, Lukasz A; Baker, David; Frydman, Judith; Levitt, Michael; Chiu, Wah

    2011-05-11

    Chaperonins are large ATP-driven molecular machines that mediate cellular protein folding. Group II chaperonins use their "built-in lid" to close their central folding chamber. Here we report the structure of an archaeal group II chaperonin in its prehydrolysis ATP-bound state at subnanometer resolution using single particle cryo-electron microscopy (cryo-EM). Structural comparison of Mm-cpn in ATP-free, ATP-bound, and ATP-hydrolysis states reveals that ATP binding alone causes the chaperonin to close slightly with a ∼45° counterclockwise rotation of the apical domain. The subsequent ATP hydrolysis drives each subunit to rock toward the folding chamber and to close the lid completely. These motions are attributable to the local interactions of specific active site residues with the nucleotide, the tight couplings between the apical and intermediate domains within the subunit, and the aligned interactions between two subunits across the rings. This mechanism of structural changes in response to ATP is entirely different from those found in group I chaperonins.

  12. Effect of chaperonin encoded by gene 146 on thermal aggregation of lytic proteins of bacteriophage EL Pseudomonas aeruginosa.

    PubMed

    Semenyuk, P I; Orlov, V N; Kurochkina, L P

    2015-02-01

    Investigation of the chaperonin encoded by gene 146 of bacteriophage EL Pseudomonas aeruginosa that we characterized earlier has been continued. To reveal the mechanism of its functioning, new recombinant substrate proteins, fragments of gene product (gp) 183 containing the lysozyme domain were prepared. Their interaction with gp146 was studied. The influence of the phage chaperonin on the thermal aggregation of one of these gp183 fragments and endolysin (gp188) was investigated in both the presence and the absence of ATP by dynamic light scattering. In the absence of ATP, the phage chaperonin forms stable complexes with substrate proteins, thereby protecting them against thermal aggregation. Experimental data obtained for different substrate proteins are analyzed.

  13. Intracellular localization of a group II chaperonin indicates a membrane-related function

    PubMed Central

    Trent, Jonathan D.; Kagawa, Hiromi K.; Paavola, Chad D.; McMillan, R. Andrew; Howard, Jeanie; Jahnke, Linda; Lavin, Colleen; Embaye, Tsegereda; Henze, Christopher E.

    2003-01-01

    Chaperonins are protein complexes that are believed to function as part of a protein folding system in the cytoplasm of the cell. We observed, however, that the group II chaperonins known as rosettasomes in the hyperthermophilic archaeon Sulfolobus shibatae, are not cytoplasmic but membrane associated. This association was observed in cultures grown at 60°C and 76°C or heat-shocked at 85°C by using immunofluorescence microscopy and in thick sections of rapidly frozen cells grown at 76°C by using immunogold electron microscopy. We observed that increased abundance of rosettasomes after heat shock correlated with decreased membrane permeability at lethal temperature (92°C). This change in permeability was not seen in cells heat-shocked in the presence of the amino acid analogue azetidine 2-carboxylic acid, indicating functional protein synthesis influences permeability. Azetidine experiments also indicated that observed heat-induced changes in lipid composition in S. shibatae could not account for changes in membrane permeability. Rosettasomes purified from cultures grown at 60°C and 76°C or heat-shocked at 85°C bind to liposomes made from either the bipolar tetraether lipids of Sulfolobus or a variety of artificial lipid mixtures. The presence of rosettasomes did not significantly change the transition temperature of liposomes, as indicated by differential scanning calorimetry, or the proton permeability of liposomes, as indicated by pyranine fluorescence. We propose that these group II chaperonins function as a structural element in the natural membrane based on their intracellular location, the correlation between their functional abundance and membrane permeability, and their potential distribution on the membrane surface. PMID:14673104

  14. Function of a thermophilic archaeal chaperonin is enhanced by electrostatic interactions with its targets.

    PubMed

    Gao, Le; Hidese, Ryota; Fujiwara, Shinsuke

    2017-09-01

    Molecular chaperonin CpkB from Thermococcus kodakarensis possesses a unique negatively charged carboxy-terminal region that functions in target protein recognition. In the present study, green fluorescent protein (GFP), 4-oxalocrotonate tautomerase (4OTA) and glutamine:fructose-6-phosphate amidotransferase (GFAT) were fused with a positively charged tag, selected using docking simulation in silico, to enhance their electrostatic interactions with CpkB. Target proteins were heated at 75°C in the presence or absence of CpkB, and the remaining enzymatic activity was measured. The half-life (t1/2) of the positively charged tagged targets was significantly longer than that of their tagless counterparts. Escherichia coli cell extracts containing heterologously expressed targets (GFP, 4OTA and GFAT and their tagged variants) were incubated at 75°C in the presence or absence of CpkB, and the proportion remaining in the soluble fraction was evaluated by SDS-PAGE. Only positively charged tagged targets remained predominantly in the soluble fraction in the presence of CpkB but not in the absence of CpkB. When tagless or negatively charged tagged targets were employed, the targets were barely detected in the soluble fraction, suggesting that CpkB protected positively charged tagged proteins more efficiently than tagless targets. Attachment of a positively charged tag may be a generally applicable method for enhancing target recognition by chaperonins carrying negatively charged carboxy-terminal regions, such as the archaeal chaperonin CpkB. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Binding of CXCR4 Transmembrane Peptides to the Bacterial Chaperonin GroEL.

    PubMed

    Wang, Xiaoqiang; Chi, Haixia; Li, Shixin; Xu, Yan

    2017-07-24

    : Newly translated membrane protein CXCR4 was observed to gain significant folding enhancement upon interacting with the bacterial chaperonin GroEL-GroES. The main fold of CXCR4 consists of 7 transmembrane α-helices distinct from soluble proteins that have dominated research on the chaperonin-assisted folding. This work extends our previous observation to the binding of GroEL with CXCR4 transmembrane peptides, which are mainly composed of hydrophobic residues characteristic of the substrates recognized by the chaperonin. We found that the model CXCR4 peptide displayed high affinity for GroEL with a binding stoichiometry near 6 or 7 depending on the analysis methods. Meanwhile, the enthalpy and entropy changes that determine the binding affinity were also measured by ITC, indicating that this process was exothermic and driven by enthalpy with entropic compensation. The binding site of the CXCR4 peptide in GroEL was also probed through competitive binding with the model peptide SBP, pointing to the groove between paired α helices H and I in the apical domain. In addition, the binding kinetics suggests a slow dissociation of the peptide-GroEL complex, in contrast to the most efficient way that GroEL along with ATP and GroES promotes the folding of substrate proteins including CXCR4, and the possible reason for this was discussed at the end. The reductionist approach by using the characteristic peptide mimetics circumvent the complications of kinetic competition between intramolecular folding and intermolecular binding to GroEL, and would provide important information on the nature of CXCR4-GroEL interaction. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Intracellular localization of a group II chaperonin indicates a membrane-related function

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan D.; Kagawa, Hiromi K.; Paavola, Chad D.; McMillan, R. Andrew; Howard, Jeanie; Jahnke, Linda; Lavin, Colleen; Embaye, Tsegereda; Henze, Christopher E.

    2003-01-01

    Chaperonins are protein complexes that are believed to function as part of a protein folding system in the cytoplasm of the cell. We observed, however, that the group II chaperonins known as rosettasomes in the hyperthermophilic archaeon Sulfolobus shibatae, are not cytoplasmic but membrane associated. This association was observed in cultures grown at 60 degrees C and 76 degrees C or heat-shocked at 85 degrees C by using immunofluorescence microscopy and in thick sections of rapidly frozen cells grown at 76 degrees C by using immunogold electron microscopy. We observed that increased abundance of rosettasomes after heat shock correlated with decreased membrane permeability at lethal temperature (92 degrees C). This change in permeability was not seen in cells heat-shocked in the presence of the amino acid analogue azetidine 2-carboxylic acid, indicating functional protein synthesis influences permeability. Azetidine experiments also indicated that observed heat-induced changes in lipid composition in S. shibatae could not account for changes in membrane permeability. Rosettasomes purified from cultures grown at 60 degrees C and 76 degrees C or heat-shocked at 85 degrees C bind to liposomes made from either the bipolar tetraether lipids of Sulfolobus or a variety of artificial lipid mixtures. The presence of rosettasomes did not significantly change the transition temperature of liposomes, as indicated by differential scanning calorimetry, or the proton permeability of liposomes, as indicated by pyranine fluorescence. We propose that these group II chaperonins function as a structural element in the natural membrane based on their intracellular location, the correlation between their functional abundance and membrane permeability, and their potential distribution on the membrane surface.

  17. The eukaryote chaperonin CCT is a cold shock protein in Saccharomyces cerevisiae

    PubMed Central

    Somer, Lilach; Shmulman, Oshrit; Dror, Tali; Hashmueli, Sharon; Kashi, Yechezkel

    2002-01-01

    The eukaryotic Hsp60 cytoplasmic chaperonin CCT (chaperonin containing the T-complex polypeptide–1) is essential for growth in budding yeast, and mutations in individual CCT subunits have been shown to affect assembly of tubulin and actin. The present research focused mainly on the expression of the CCT subunits, CCTα and CCTβ, in yeast (Saccharomyces cerevisiae). Previous studies showed that, unlike most other chaperones, CCT in yeast does not undergo induction following heat shock. In this study, messenger ribonucleic acid (mRNA) and protein levels of CCT subunits following exposure to low temperatures, were examined. The Northern blot analysis indicated a 3- to 4-fold increase in mRNA levels of CCTα and CCTβ genes after cold shock at 4°C. Interestingly, Western blot analysis showed that cold shock induces an increase in the CCTα protein, which is expressed at 10°C, but not at 4°C. Transfer of 4°C cold-shocked cells to 10°C induced a 5-fold increase in the CCTα protein level. By means of fluorescent immunostaining and confocal microscopy, we found CCTα to be localized in the cortex and the cell cytoplasm of S. cerevisiae. Localization of CCTα was not affected at low temperatures. Co-localization of CCT and filaments of actin and tubulin was not observed by microscopy. The induction pattern of the CCTα protein suggests that expression of the chaperonin may be primarily important during the recovery from low temperatures and the transition to growth at higher temperatures, as found for other Hsps during the recovery phase from heat shock. PMID:11892987

  18. Intracellular localization of a group II chaperonin indicates a membrane-related function

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan D.; Kagawa, Hiromi K.; Paavola, Chad D.; McMillan, R. Andrew; Howard, Jeanie; Jahnke, Linda; Lavin, Colleen; Embaye, Tsegereda; Henze, Christopher E.

    2003-01-01

    Chaperonins are protein complexes that are believed to function as part of a protein folding system in the cytoplasm of the cell. We observed, however, that the group II chaperonins known as rosettasomes in the hyperthermophilic archaeon Sulfolobus shibatae, are not cytoplasmic but membrane associated. This association was observed in cultures grown at 60 degrees C and 76 degrees C or heat-shocked at 85 degrees C by using immunofluorescence microscopy and in thick sections of rapidly frozen cells grown at 76 degrees C by using immunogold electron microscopy. We observed that increased abundance of rosettasomes after heat shock correlated with decreased membrane permeability at lethal temperature (92 degrees C). This change in permeability was not seen in cells heat-shocked in the presence of the amino acid analogue azetidine 2-carboxylic acid, indicating functional protein synthesis influences permeability. Azetidine experiments also indicated that observed heat-induced changes in lipid composition in S. shibatae could not account for changes in membrane permeability. Rosettasomes purified from cultures grown at 60 degrees C and 76 degrees C or heat-shocked at 85 degrees C bind to liposomes made from either the bipolar tetraether lipids of Sulfolobus or a variety of artificial lipid mixtures. The presence of rosettasomes did not significantly change the transition temperature of liposomes, as indicated by differential scanning calorimetry, or the proton permeability of liposomes, as indicated by pyranine fluorescence. We propose that these group II chaperonins function as a structural element in the natural membrane based on their intracellular location, the correlation between their functional abundance and membrane permeability, and their potential distribution on the membrane surface.

  19. Crystal Structures of a Group II Chaperonin Reveal the Open and Closed States Associated with the Protein Folding Cycle*♦

    PubMed Central

    Pereira, Jose H.; Ralston, Corie Y.; Douglas, Nicholai R.; Meyer, Daniel; Knee, Kelly M.; Goulet, Daniel R.; King, Jonathan A.; Frydman, Judith; Adams, Paul D.

    2010-01-01

    Chaperonins are large protein complexes consisting of two stacked multisubunit rings, which open and close in an ATP-dependent manner to create a protected environment for protein folding. Here, we describe the first crystal structure of a group II chaperonin in an open conformation. We have obtained structures of the archaeal chaperonin from Methanococcus maripaludis in both a peptide acceptor (open) state and a protein folding (closed) state. In contrast with group I chaperonins, in which the equatorial domains share a similar conformation between the open and closed states and the largest motions occurs at the intermediate and apical domains, the three domains of the archaeal chaperonin subunit reorient as a single rigid body. The large rotation observed from the open state to the closed state results in a 65% decrease of the folding chamber volume and creates a highly hydrophilic surface inside the cage. These results suggest a completely distinct closing mechanism in the group II chaperonins as compared with the group I chaperonins. PMID:20573955

  20. Probing Water Density and Dynamics in the Chaperonin GroEL Cavity

    PubMed Central

    2015-01-01

    ATP-dependent binding of the chaperonin GroEL to its cofactor GroES forms a cavity in which encapsulated substrate proteins can fold in isolation from bulk solution. It has been suggested that folding in the cavity may differ from that in bulk solution owing to steric confinement, interactions with the cavity walls, and differences between the properties of cavity-confined and bulk water. However, experimental data regarding the cavity-confined water are lacking. Here, we report measurements of water density and diffusion dynamics in the vicinity of a spin label attached to a cysteine in the Tyr71 → Cys GroES mutant obtained using two magnetic resonance techniques: electron-spin echo envelope modulation and Overhauser dynamic nuclear polarization. Residue 71 in GroES is fully exposed to bulk water in free GroES and to confined water within the cavity of the GroEL–GroES complex. Our data show that water density and translational dynamics in the vicinity of the label do not change upon complex formation, thus indicating that bulk water-exposed and cavity-confined GroES surface water share similar properties. Interestingly, the diffusion dynamics of water near the GroES surface are found to be unusually fast relative to other protein surfaces studied. The implications of these findings for chaperonin-assisted folding mechanisms are discussed. PMID:24888581

  1. Versatile roles of the chaperonin GroEL in microorganism-insect interactions.

    PubMed

    Kupper, Maria; Gupta, Shishir K; Feldhaar, Heike; Gross, Roy

    2014-04-01

    The chaperonin 60 (Cpn60) is present in all three kingdoms of life and is one of the most conserved proteins in living organisms. The Escherichia coli Cpn60 (GroEL) is the best studied representative of the huge Cpn60 family. It is an essential protein because in conjunction with the chaperonin 10 (Cpn10 or GroES) it forms a protein-folding machine required for correct folding of many proteins and for recycling of misfolded proteins. As many other chaperones, GroEL and GroES are also known as heat-shock proteins (HSPs), since heat stress leads to a strong induction of their expression, a measure to counteract the increase in misfolded proteins as a result of a high nonphysiological temperature. A large amount of literature is available which is dedicated to the elucidation of how protein folding is assisted by this molecular chaperone. However, apart from this primary task, additional so-called 'moonlighting' functions of GroEL proteins unrelated to their folding activity have emerged in the past years. In fact, it becomes apparent that GroEL proteins have diverse functions in particular in mutualistic and pathogenic microorganism-host interactions. In this brief review, we describe some of these recent findings focusing on the importance of GroEL for microorganism-insect interactions.

  2. Effect of interactions with the chaperonin cavity on protein folding and misfolding.

    PubMed

    Sirur, Anshul; Knott, Michael; Best, Robert B

    2014-04-14

    Recent experimental and computational results have suggested that attractive interactions between a chaperonin and an enclosed substrate can have an important effect on the protein folding rate: it appears that folding may even be slower inside the cavity than under unconfined conditions, in contrast to what we would expect from excluded volume effects on the unfolded state. Here we examine systematically the dependence of the protein stability and folding rate on the strength of such attractive interactions between the chaperonin and substrate, by using molecular simulations of model protein systems in an idealised attractive cavity. Interestingly, we find a maximum in stability, and a rate which indeed slows down at high attraction strengths. We have developed a simple phenomenological model which can explain the variations in folding rate and stability due to differing effects on the free energies of the unfolded state, folded state, and transition state; changes in the diffusion coefficient along the folding coordinate are relatively small, at least for our simplified model. In order to investigate a possible role for these attractive interactions in folding, we have studied a recently developed model for misfolding in multidomain proteins. We find that, while encapsulation in repulsive cavities greatly increases the fraction of misfolded protein, sufficiently strong attractive protein-cavity interactions can strongly reduce the fraction of proteins reaching misfolded traps.

  3. Proteome-wide analysis of chaperonin-dependent protein folding in Escherichia coli.

    PubMed

    Kerner, Michael J; Naylor, Dean J; Ishihama, Yasushi; Maier, Tobias; Chang, Hung-Chun; Stines, Anna P; Georgopoulos, Costa; Frishman, Dmitrij; Hayer-Hartl, Manajit; Mann, Matthias; Hartl, F Ulrich

    2005-07-29

    The E. coli chaperonin GroEL and its cofactor GroES promote protein folding by sequestering nonnative polypeptides in a cage-like structure. Here we define the contribution of this system to protein folding across the entire E. coli proteome. Approximately 250 different proteins interact with GroEL, but most of these can utilize either GroEL or the upstream chaperones trigger factor (TF) and DnaK for folding. Obligate GroEL-dependence is limited to only approximately 85 substrates, including 13 essential proteins, and occupying more than 75% of GroEL capacity. These proteins appear to populate kinetically trapped intermediates during folding; they are stabilized by TF/DnaK against aggregation but reach native state only upon transfer to GroEL/GroES. Interestingly, substantially enriched among the GroEL substrates are proteins with (betaalpha)8 TIM-barrel domains. We suggest that the chaperonin system may have facilitated the evolution of this fold into a versatile platform for the implementation of numerous enzymatic functions.

  4. A Chaperonin Subunit with Unique Structures Is Essential for Folding of a Specific Substrate

    PubMed Central

    Peng, Lianwei; Fukao, Yoichiro; Myouga, Fumiyoshi; Motohashi, Reiko; Shinozaki, Kazuo; Shikanai, Toshiharu

    2011-01-01

    Type I chaperonins are large, double-ring complexes present in bacteria (GroEL), mitochondria (Hsp60), and chloroplasts (Cpn60), which are involved in mediating the folding of newly synthesized, translocated, or stress-denatured proteins. In Escherichia coli, GroEL comprises 14 identical subunits and has been exquisitely optimized to fold its broad range of substrates. However, multiple Cpn60 subunits with different expression profiles have evolved in chloroplasts. Here, we show that, in Arabidopsis thaliana, the minor subunit Cpn60β4 forms a heterooligomeric Cpn60 complex with Cpn60α1 and Cpn60β1–β3 and is specifically required for the folding of NdhH, a subunit of the chloroplast NADH dehydrogenase-like complex (NDH). Other Cpn60β subunits cannot complement the function of Cpn60β4. Furthermore, the unique C-terminus of Cpn60β4 is required for the full activity of the unique Cpn60 complex containing Cpn60β4 for folding of NdhH. Our findings suggest that this unusual kind of subunit enables the Cpn60 complex to assist the folding of some particular substrates, whereas other dominant Cpn60 subunits maintain a housekeeping chaperonin function by facilitating the folding of other obligate substrates. PMID:21483722

  5. Mycobacterium tuberculosis Chaperonin 10 Heptamers Self-Associate through Their Biologically Active Loops

    PubMed Central

    Roberts, Michael M.; Coker, Alun R.; Fossati, Gianluca; Mascagni, Paolo; Coates, Anthony R. M.; Wood, Steve P.

    2003-01-01

    The crystal structure of Mycobacterium tuberculosis chaperonin 10 (cpn10Mt) has been determined to a resolution of 2.8 Å. Two dome-shaped cpn10Mt heptamers complex through loops at their bases to form a tetradecamer with 72 symmetry and a spherical cage-like structure. The hollow interior enclosed by the tetradecamer is lined with hydrophilic residues and has dimensions of 30 Å perpendicular to and 60 Å along the sevenfold axis. Tetradecameric cpn10Mt has also been observed in solution by dynamic light scattering. Through its base loop sequence cpn10Mt is known to be the agent in the bacterium responsible for bone resorption and for the contribution towards its strong T-cell immunogenicity. Superimposition of the cpn10Mt sequences 26 to 32 and 66 to 72 and E. coli GroES 25 to 31 associated with bone resorption activity shows them to have similar conformations and structural features, suggesting that there may be a common receptor for the bone resorption sequences. The base loops of cpn10s in general also attach to the corresponding chaperonin 60 (cpn60) to enclose unfolded protein and to facilitate its correct folding in vivo. Electron density corresponding to a partially disordered protein subunit appears encapsulated within the interior dome cavity of each heptamer. This suggests that the binding of substrates to cpn10 is possible in the absence of cpn60. PMID:12837792

  6. Role of denatured-state properties in chaperonin action probed by single-molecule spectroscopy.

    PubMed

    Hofmann, Hagen; Hillger, Frank; Delley, Cyrille; Hoffmann, Armin; Pfeil, Shawn H; Nettels, Daniel; Lipman, Everett A; Schuler, Benjamin

    2014-12-16

    The bacterial chaperonin GroEL/GroES assists folding of a broad spectrum of denatured and misfolded proteins. Here, we explore the limits of this remarkable promiscuity by mapping two denatured proteins with very different conformational properties, rhodanese and cyclophilin A, during binding and encapsulation by GroEL/GroES with single-molecule spectroscopy, microfluidic mixing, and ensemble kinetics. We find that both proteins bind to GroEL with high affinity in a reaction involving substantial conformational adaptation. However, whereas the compact denatured state of rhodanese is encapsulated efficiently upon addition of GroES and ATP, the more expanded and unstructured denatured cyclophilin A is not encapsulated but is expelled into solution. The origin of this surprising disparity is the weaker interactions of cyclophilin A with a transiently formed GroEL-GroES complex, which may serve as a crucial checkpoint for substrate discrimination.

  7. Role of Denatured-State Properties in Chaperonin Action Probed by Single-Molecule Spectroscopy

    PubMed Central

    Hofmann, Hagen; Hillger, Frank; Delley, Cyrille; Hoffmann, Armin; Pfeil, Shawn H.; Nettels, Daniel; Lipman, Everett A.; Schuler, Benjamin

    2014-01-01

    The bacterial chaperonin GroEL/GroES assists folding of a broad spectrum of denatured and misfolded proteins. Here, we explore the limits of this remarkable promiscuity by mapping two denatured proteins with very different conformational properties, rhodanese and cyclophilin A, during binding and encapsulation by GroEL/GroES with single-molecule spectroscopy, microfluidic mixing, and ensemble kinetics. We find that both proteins bind to GroEL with high affinity in a reaction involving substantial conformational adaptation. However, whereas the compact denatured state of rhodanese is encapsulated efficiently upon addition of GroES and ATP, the more expanded and unstructured denatured cyclophilin A is not encapsulated but is expelled into solution. The origin of this surprising disparity is the weaker interactions of cyclophilin A with a transiently formed GroEL-GroES complex, which may serve as a crucial checkpoint for substrate discrimination. PMID:25517154

  8. Monomer-heptamer equilibrium of the Escherichia coli chaperonin GroES.

    PubMed

    Zondlo, J; Fisher, K E; Lin, Z; Ducote, K R; Eisenstein, E

    1995-08-22

    In an effort to clarify the role of GroES in chaperonin-facilitated protein folding, a plasmid-encoding expression system for GroES incorporating a histidine-tagged, thrombin-cleavable, N-terminal sequence was constructed. This approach facilitated the rapid purification of native-like, histidine-cleaved GroES (HC-GroES). The addition of NaSCN to purification buffers to mildly promote subunit dissociation enabled the complete separation of chromosomally encoded, wild-type GroES chains from recombinant chains, allowing the production of homogeneous mutant variants of GroES. A substitution of histidine-7 to tryptophan in GroES was used to demonstrate the concentration-dependent modulation of the heptameric quaternary structure of the chaperonin. Fluorescence and light scattering studies of this mutant suggest that GroES heptamers dissociate to monomers upon dilution with half-times of 2-4 min. Sedimentation equilibrium experiments using either wild-type or HC-GroES can best be described by a monomer--heptamer equilibrium, yielding dissociation constants of 1 x 10(-38) M6 for native GroES and 2 x 10(-32) M6 for HC-GroES. These results are supported by subunit exchange experiments using mixtures of native or HC-GroES and GroES containing the complete N-terminal histidine tail. Native polyacrylamide gel electrophoresis demonstrates that these mixtures form an eight-membered hybrid set within minutes. The studies described here suggest a dynamic equilibrium for the quaternary structure of GroES, which may be an important feature for its role in GroEL-mediated protein folding reactions.

  9. Exogenous delivery of chaperonin subunit fragment ApiCCT1 modulates mutant Huntingtin cellular phenotypes

    PubMed Central

    Sontag, Emily M.; Joachimiak, Lukasz A.; Tan, Zhiqun; Tomlinson, Anthony; Housman, David E.; Glabe, Charles G.; Potkin, Steven G.; Frydman, Judith; Thompson, Leslie M.

    2013-01-01

    Aggregation of misfolded proteins is characteristic of a number of neurodegenerative diseases, including Huntington disease (HD). The CCT/TRiC (chaperonin containing TCP-1/TCP-1 ring) chaperonin complex can inhibit aggregation and cellular toxicity induced by expanded repeat Huntingtin (mHtt) fragments. The substrate-binding apical domain of CCT/TRiC subunit CCT1, ApiCCT1, is sufficient to inhibit aggregation of expanded repeat mHtt fragments in vitro, providing therapeutic promise for HD. However, a key hurdle in considering ApiCCT1 as a potential treatment is in delivery. Because ApiCCT1 has a region of similarity to the HIV Tat protein cell-transduction domain, we tested whether recombinant ApiCCT1 (ApiCCT1r) protein could enter cells following exogenous delivery and modulate an established panel of mHtt-mediated cell-based phenotypes. Cell fractionation studies demonstrate that exogenous ApiCCT1r can penetrate cell membranes and can localize to the nucleus, consistent with a strategy that can target both cytosolic and nuclear pathogenic events in HD. ApiCCT1r application does indeed modulate HD cellular phenotypes by decreasing formation of visible inclusions, fibrillar oligomers, and insoluble mHtt derived from expression of a truncated mHtt exon 1 fragment. ApiCCT1r also delays the onset of inclusion body formation as visualized via live imaging. ApiCCT1r reduces mHtt-mediated toxicity in immortalized striatal cells derived from full-length knock-in HD mice, suggesting that therapeutic benefit may extend beyond effects on aggregation. These studies provide the basis for a potentially robust and unique therapeutic strategy to target mHtt-mediated protein pathogenesis. PMID:23365139

  10. Simulation of the shape of chaperonins using the small-angle x-ray scattering curves and torus form factor

    SciTech Connect

    Amarantov, S. V.; Naletova, I. N.; Kurochkina, L. P.

    2011-08-15

    The inverse scattering problem has been solved for protein complexes whose surfaces can be described by a set of the simplest doubly connected surfaces in the uniform approximation (a scattering potential inside the molecule is a constant). Solutions of two proteins-well-known GroEL bacterial chaperonin and poor-studied bacteriophage chaperonin, which is a product of 146 gene (gp146)-were taken for the experiment. The shapes of protein complexes have been efficiently reconstructed from the experimental scattering curves. The shell method, the method of the rotation of amino acid sequences with the use of the form factor of an amino acid, and the method of seeking the model parameters of a protein complex with the preliminarily obtained form factor of the model have been used to reconstruct the shape of these particles.

  11. Crystallization and preliminary X-ray crystallographic analysis of the XoGroEL chaperonin from Xanthomonas oryzae pv. oryzae.

    PubMed

    Tran, Huyen Thi; Pham, Tan Viet; Ngo, Ho Phuong Thuy; Hong, Myoung Ki; Kim, Jeong Gu; Lee, Sang Hee; Ahn, Yeh Jin; Kang, Lin Woo

    2014-05-01

    Along with the co-chaperonin GroES, the chaperonin GroEL plays an essential role in enhancing protein folding or refolding and in protecting proteins against misfolding and aggregation in the cellular environment. The XoGroEL gene (XOO_4288) from Xanthomonas oryzae pv. oryzae was cloned and the protein was expressed, purified and crystallized. The purified XoGroEL protein was crystallized using the hanging-drop vapour-diffusion method and a crystal diffracted to a resolution of 3.4 Å. The crystal belonged to the orthorhombic space group P212121 with 14 monomers in the asymmetric unit, with a corresponding VM of 2.7 Å(3) Da(-1) and a solvent content of 54.5%.

  12. Surviving cancer without compromising aspirations.

    PubMed

    McGregor, Sandra

    2011-07-01

    This short paper is a reflection of how one person coped, survived and grew following numerous metastatic incidences over a 20 year period. Surviving cancer is a complex process but coping with the threat of regular recurrence has required a coping strategy that embraced the disease, set it aside and refused to compromise hopes, dreams and future life. Central to this personal journey has been the need to redefine normality, live with and set aside the fear of future metastases and death and find an answer and meaning in a changing biology, increased morbidity and possible mortality. This paper contends that not compromising the direction of travel and being able to focus on a career has ensured that survival was valuable and valued. A working environment in which students' problems have been immediate has produced different stressors. These have ultimately forced personal worries to be set aside, while living with cancer has become normal and accepted. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. 22 CFR 34.19 - Compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compromise. 34.19 Section 34.19 Foreign Relations DEPARTMENT OF STATE CLAIMS AND STOLEN PROPERTY DEBT COLLECTION Collection Adjustments § 34.19 Compromise. STATE may attempt to effect compromise in accordance with the standards set forth in the FCCS,...

  14. 22 CFR 309.20 - Compromise.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Compromise. 309.20 Section 309.20 Foreign Relations PEACE CORPS DEBT COLLECTION Salary Offset § 309.20 Compromise. Peace Corps may attempt to effect compromise in accordance with the standards set forth in the FCCS (31 CFR part 902). ...

  15. 22 CFR 309.20 - Compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Compromise. 309.20 Section 309.20 Foreign Relations PEACE CORPS DEBT COLLECTION Salary Offset § 309.20 Compromise. Peace Corps may attempt to effect compromise in accordance with the standards set forth in the FCCS (31 CFR part 902). ...

  16. 22 CFR 309.20 - Compromise.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Compromise. 309.20 Section 309.20 Foreign Relations PEACE CORPS DEBT COLLECTION Salary Offset § 309.20 Compromise. Peace Corps may attempt to effect compromise in accordance with the standards set forth in the FCCS (31 CFR part 902)....

  17. 22 CFR 309.20 - Compromise.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Compromise. 309.20 Section 309.20 Foreign Relations PEACE CORPS DEBT COLLECTION Salary Offset § 309.20 Compromise. Peace Corps may attempt to effect compromise in accordance with the standards set forth in the FCCS (31 CFR part 902)....

  18. 22 CFR 309.20 - Compromise.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Compromise. 309.20 Section 309.20 Foreign Relations PEACE CORPS DEBT COLLECTION Salary Offset § 309.20 Compromise. Peace Corps may attempt to effect compromise in accordance with the standards set forth in the FCCS (31 CFR part 902)....

  19. Chaperonin Cofactors, Cpn10 and Cpn20, of Green Algae and Plants Function as Hetero-oligomeric Ring Complexes*♦

    PubMed Central

    Tsai, Yi-Chin C.; Mueller-Cajar, Oliver; Saschenbrecker, Sandra; Hartl, F. Ulrich; Hayer-Hartl, Manajit

    2012-01-01

    The chloroplast chaperonin system of plants and green algae is a curiosity as both the chaperonin cage and its lid are encoded by multiple genes, in contrast to the single genes encoding the two components of the bacterial and mitochondrial systems. In the green alga Chlamydomonas reinhardtii (Cr), three genes encode chaperonin cofactors, with cpn10 encoding a single ∼10-kDa domain and cpn20 and cpn23 encoding tandem cpn10 domains. Here, we characterized the functional interaction of these proteins with the Escherichia coli chaperonin, GroEL, which normally cooperates with GroES, a heptamer of ∼10-kDa subunits. The C. reinhardtii cofactor proteins alone were all unable to assist GroEL-mediated refolding of bacterial ribulose-bisphosphate carboxylase/oxygenase but gained this ability when CrCpn20 and/or CrCpn23 was combined with CrCpn10. Native mass spectrometry indicated the formation of hetero-oligomeric species, consisting of seven ∼10-kDa domains. The cofactor “heptamers” interacted with GroEL and encapsulated substrate protein in a nucleotide-dependent manner. Different hetero-oligomer arrangements, generated by constructing cofactor concatamers, indicated a preferential heptamer configuration for the functional CrCpn10-CrCpn23 complex. Formation of heptamer Cpn10/Cpn20 hetero-oligomers was also observed with the Arabidopsis thaliana (At) cofactors, which functioned with the chloroplast chaperonin, AtCpn60α7β7. It appears that hetero-oligomer formation occurs more generally for chloroplast chaperonin cofactors, perhaps adapting the chaperonin system for the folding of specific client proteins. PMID:22518837

  20. The htpAB operon of Legionella pneumophila cannot be deleted in the presence of the groE chaperonin operon of Escherichia coli.

    PubMed

    Nasrallah, Gheyath K; Gagnon, Elizabeth; Orton, Dennis J; Garduño, Rafael A

    2011-11-01

    HtpB, the chaperonin of the intracellular bacterial pathogen Legionella pneumophila , displays several virulence-related functions in vitro. To confirm HtpB's role in vivo, host infections with an htpB deletion mutant would be required. However, we previously reported that the htpAB operon (encoding co-chaperonin and chaperonin) is essential. We attempted here to delete htpAB in a L. pneumophila strain carrying the groE operon (encoding the Escherichia coli co-chaperonin and chaperonin). The groE operon was inserted into the chromosome of L. pneumophila Lp02, and then allelic replacement of htpAB with a gentamicin resistance cassette was attempted. Although numerous potential postallelic replacement transformants showed a correct selection phenotype, we still detected htpAB by PCR and full-size HtpB by immunoblot. Southern blot and PCR analysis indicated that the gentamicin resistance cassette had apparently integrated in a duplicated htpAB region. However, we showed by Southern blot that strain Lp02, and the Lp02 derivative carrying the groE operon, have only one copy of htpAB. These results confirmed that the htpAB operon cannot be deleted, not even in the presence of the groE operon, and suggested that attempts to delete htpAB under strong phenotypic selection result in aberrant genetic recombinations that could involve duplication of the htpAB locus.

  1. Physiological effects of unassembled chaperonin Cct subunits in the yeast Saccharomyces cerevisiae.

    PubMed

    Kabir, M Anaul; Kaminska, Joanna; Segel, George B; Bethlendy, Gabor; Lin, Paul; Della Seta, Flavio; Blegen, Casey; Swiderek, Kristine M; Zoładek, Teresa; Arndt, Kim T; Sherman, Fred

    2005-02-01

    Eukaryotic chaperonins, the Cct complexes, are assembled into two rings, each of which is composed of a stoichiometric array of eight different subunits, which are denoted Cct1p-Cct8p. Overexpression of a single CCT gene in Saccharomyces cerevisiae causes an increase of the corresponding Cct subunit, but not of the Cct complex. Nevertheless, overexpression of certain Cct subunits, especially CCT6, suppresses a wide range of abnormal phenotypes, including those caused by the diverse types of conditional mutations tor2-21, lst8-2 and rsp5-9 and those caused by the concomitant overexpression of Sit4p and Sap155p. The examination of 73 altered forms of Cct6p revealed that the cct6-24 mutation, containing GDGTT --> AAAAA replacements of the conserved ATP-binding motif, was unable to suppress any of these traits, although the cct6-24 allele was completely functional for growth. These results provide evidence for functional differences among Cct subunits and for physiological properties of unassembled subunits. We suggest that the suppression is due to the competition of specific Cct subunits for activities that normally modify various cellular components. Furthermore, we also suggest that the Cct subunits can act as suppressors only in certain states, such as when associated with ATP.

  2. Beyond Antibodies: Development of a Novel Protein Scaffold Based on Human Chaperonin 10

    PubMed Central

    Alsultan, Abdulkarim M.; Chin, David Y.; Howard, Christopher B.; de Bakker, Christopher J.; Jones, Martina L.; Mahler, Stephen M.

    2016-01-01

    Human Chaperonin 10 (hCpn10) was utilised as a novel scaffold for presenting peptides of therapeutic and diagnostic significance. Molecular dynamic simulations and protein sizing analyses identified a peptide linker (P1) optimal for the formation of the quarternary hCpn10 heptamer structure. hCpn10 scaffold displaying peptides targeting Factor VIIa (CE76-P1) and CD44 (CP7) were expressed in E. coli. Functional studies of CE76-P1 indicated nanomolar affinity for Factor VIIa (3 nM) similar to the E-76 peptide (6 nM), with undetectable binding to Factor X. CE76-P1 was a potent inhibitor of FX activity (via inhibition of Factor VIIa) and prolonged clot formation 4 times longer than achieved by E-76 peptide as determined by prothrombin time (PT) assays. This improvement in clotting function by CE76-P1, highlights the advantages of a heptamer-based scaffold for improving avidity by multiple peptide presentation. In another example of hCPn10 utility as a scaffold, CP7 bound to native CD44 overexpressed on cancer cells and bound rCD44 with high affinity (KD 9.6 nM). The ability to present various peptides through substitution of the hCpn10 mobile loop demonstrates its utility as a novel protein scaffold. PMID:27874025

  3. Conversion of a Chaperonin GroEL-independent Protein into an Obligate Substrate*

    PubMed Central

    Ishimoto, Takuya; Fujiwara, Kei; Niwa, Tatsuya; Taguchi, Hideki

    2014-01-01

    Chaperones assist protein folding by preventing unproductive protein aggregation in the cell. In Escherichia coli, chaperonin GroEL/GroES (GroE) is the only indispensable chaperone and is absolutely required for the de novo folding of at least ∼60 proteins. We previously found that several orthologs of the obligate GroE substrates in Ureaplasma urealyticum, which lacks the groE gene in the genome, are E. coli GroE-independent folders, despite their significant sequence identities. Here, we investigated the key features that define the GroE dependence. Chimera or random mutagenesis analyses revealed that independent multiple point mutations, and even single mutations, were sufficient to confer GroE dependence on the Ureaplasma MetK. Strikingly, the GroE dependence was well correlated with the propensity to form protein aggregates during folding. The results reveal the delicate balance between GroE dependence and independence. The function of GroE to buffering the aggregation-prone mutations plays a role in maintaining higher genetic diversity of proteins. PMID:25288795

  4. Allosteric Transitions of Supramolecular Systems Explored by Network Models: Application to Chaperonin GroEL

    PubMed Central

    Yang, Zheng; Májek, Peter; Bahar, Ivet

    2009-01-01

    Identification of pathways involved in the structural transitions of biomolecular systems is often complicated by the transient nature of the conformations visited across energy barriers and the multiplicity of paths accessible in the multidimensional energy landscape. This task becomes even more challenging in exploring molecular systems on the order of megadaltons. Coarse-grained models that lend themselves to analytical solutions appear to be the only possible means of approaching such cases. Motivated by the utility of elastic network models for describing the collective dynamics of biomolecular systems and by the growing theoretical and experimental evidence in support of the intrinsic accessibility of functional substates, we introduce a new method, adaptive anisotropic network model (aANM), for exploring functional transitions. Application to bacterial chaperonin GroEL and comparisons with experimental data, results from action minimization algorithm, and previous simulations support the utility of aANM as a computationally efficient, yet physically plausible, tool for unraveling potential transition pathways sampled by large complexes/assemblies. An important outcome is the assessment of the critical inter-residue interactions formed/broken near the transition state(s), most of which involve conserved residues. PMID:19381265

  5. Identifying natural substrates for chaperonins using a sequence-based approach

    PubMed Central

    Stan, George; Brooks, Bernard R.; Lorimer, George H.; Thirumalai, D.

    2005-01-01

    The Escherichia coli chaperonin machinery, GroEL, assists the folding of a number of proteins. We describe a sequence-based approach to identify the natural substrate proteins (SPs) for GroEL. Our method is based on the hypothesis that natural SPs are those that contain patterns of residues similar to those found in either GroES mobile loop and/or strongly binding peptide in complex with GroEL. The method is validated by comparing the predicted results with experimentally determined natural SPs for GroEL. We have searched for such patterns in five genomes. In the E. coli genome, we identify 1422 (about one-third) sequences that are putative natural SPs. In Saccharomyces cerevisiae, 2885 (32%) of sequences can be natural substrates for Hsp60, which is the analog of GroEL. The precise number of natural SPs is shown to be a function of the number of contacts an SP makes with the apical domain (NC) and the number of binding sites (NB) in the oligomer with which it interacts. For known SPs for GroEL, we find ~4 < NC < 5 and 2 ≤ NB ≤ 4. A limited analysis of the predicted binding sequences shows that they do not adopt any preferred secondary structure. Our method also predicts the putative binding regions in the identified SPs. The results of our study show that a variety of SPs, associated with diverse functions, can interact with GroEL. PMID:15576562

  6. Setting the chaperonin timer: The effects of K+ and substrate protein on ATP hydrolysis

    PubMed Central

    Grason, John P.; Gresham, Jennifer S.; Widjaja, Lusiana; Wehri, Sarah C.; Lorimer, George H.

    2008-01-01

    The effects of potassium ion on the nested allostery of GroEL are due to increases in the affinity for nucleotide. Both positive allosteric transitions, TT-TR and TR-RR, occur at lower [ATP] as [K+] is increased. Negative cooperativity in the double-ringed system is also due to an increase in the affinity of the trans ring for the product ADP as [K+] is increased. Consequently, (i) rates of ATP hydrolysis are inversely proportional to [K+] and (ii) the residence time of GroES bound to the cis ring is prolonged and the hemicycle time extended. Substrate protein suppresses negative cooperativity by decreasing the affinity of the trans ring for ADP, reducing the hemicycle time to a constant minimum. The trans ring thus serves as a variable timer. ATP added to the asymmetric GroEL-GroES resting-state complex lacking trans ring ADP is hydrolyzed in the newly formed cis ring with a presteady-state burst of ≈6 mol of Pi per mole of 14-mer. No burst is observed when the trans ring contains ADP. The amplitude and kinetics of ATP hydrolysis in the cis ring are independent of the presence or absence of encapsulated substrate protein and independent of K+ at concentrations where there are profound effects on the linear steady-state rate. The hydrolysis of ATP by the cis ring constitutes a second, nonvariable timer of the chaperonin cycle. PMID:18988745

  7. Setting the chaperonin timer: the effects of K+ and substrate protein on ATP hydrolysis.

    PubMed

    Grason, John P; Gresham, Jennifer S; Widjaja, Lusiana; Wehri, Sarah C; Lorimer, George H

    2008-11-11

    The effects of potassium ion on the nested allostery of GroEL are due to increases in the affinity for nucleotide. Both positive allosteric transitions, TT-TR and TR-RR, occur at lower [ATP] as [K(+)] is increased. Negative cooperativity in the double-ringed system is also due to an increase in the affinity of the trans ring for the product ADP as [K(+)] is increased. Consequently, (i) rates of ATP hydrolysis are inversely proportional to [K(+)] and (ii) the residence time of GroES bound to the cis ring is prolonged and the hemicycle time extended. Substrate protein suppresses negative cooperativity by decreasing the affinity of the trans ring for ADP, reducing the hemicycle time to a constant minimum. The trans ring thus serves as a variable timer. ATP added to the asymmetric GroEL-GroES resting-state complex lacking trans ring ADP is hydrolyzed in the newly formed cis ring with a presteady-state burst of approximately 6 mol of Pi per mole of 14-mer. No burst is observed when the trans ring contains ADP. The amplitude and kinetics of ATP hydrolysis in the cis ring are independent of the presence or absence of encapsulated substrate protein and independent of K(+) at concentrations where there are profound effects on the linear steady-state rate. The hydrolysis of ATP by the cis ring constitutes a second, nonvariable timer of the chaperonin cycle.

  8. Ancient allelism at the cytosolic chaperonin-alpha-encoding gene of the zebrafish.

    PubMed Central

    Takami, K; Figueroa, F; Mayer, W E; Klein, J

    2000-01-01

    The T-complex protein 1, TCP1, gene codes for the CCT-alpha subunit of the group II chaperonins. The gene was first described in the house mouse, in which it is closely linked to the T locus at a distance of approximately 11 cM from the Mhc. In the zebrafish, Danio rerio, in which the T homolog is linked to the class I Mhc loci, the TCP1 locus segregates independently of both the T and the Mhc loci. Despite its conservation between species, the zebrafish TCP1 locus is highly polymorphic. In a sample of 15 individuals and the screening of a cDNA library, 12 different alleles were found, and some of the allelic pairs were found to differ by up to nine nucleotides in a 275-bp-long stretch of sequence. The substitutions occur in both translated and untranslated regions, but in the former they occur predominantly at synonymous codon sites. Phylogenetically, the alleles fall into two groups distinguished also by the presence or absence of a 10-bp insertion/deletion in the 3' untranslated region. The two groups may have diverged as long as 3.5 mya, and the polymorphic differences may have accumulated by genetic drift in geographically isolated populations. PMID:10628990

  9. A zinc-binding site by negative selection induces metallodrug susceptibility in an essential chaperonin

    PubMed Central

    Cun, Shujian; Sun, Hongzhe

    2010-01-01

    GroES is an indispensable chaperonin virtually found throughout all life forms. Consequently, mutations of this protein must be critically scrutinized by natural selection. Nevertheless, the homolog from a potentially virulent gastric pathogen, Helicobacter pylori, strikingly features a histidine/cysteine-rich C terminus that shares no significant homology with other family members. Additionally, three more (H45, C51, and C53) are uniquely present in its apical domain. The statistical analyses show that these residues may have originated from negative selection, presumably driven by either dependent or independent amino acid mutations. In the absence of the C-terminal metal-binding domain, the mutant protein still exhibits a substantial capacity for zinc binding in vivo. The biochemical properties of site-directed mutants indicate that H45, C51, and C53 make up an oxidation-sensitive zinc-binding site that may donate the bound metal to a zinc acceptor. Of interest, bismuth antiulcer drugs strongly bind at this site (Kd of approximately 7 × 10-26 M), replacing the bound zinc and consequently inducing the disruption of the quaternary structure. Because biological features by negative selection are usually inert to change during evolution, this study sheds light on a promising field whereby medicines can be designed or improved to specifically target the residues that uniquely evolved in pathogenic proteins so as to retard the emergence of drug resistance. PMID:20194796

  10. Forensic Analysis of Compromised Computers

    NASA Technical Reports Server (NTRS)

    Wolfe, Thomas

    2004-01-01

    Directory Tree Analysis File Generator is a Practical Extraction and Reporting Language (PERL) script that simplifies and automates the collection of information for forensic analysis of compromised computer systems. During such an analysis, it is sometimes necessary to collect and analyze information about files on a specific directory tree. Directory Tree Analysis File Generator collects information of this type (except information about directories) and writes it to a text file. In particular, the script asks the user for the root of the directory tree to be processed, the name of the output file, and the number of subtree levels to process. The script then processes the directory tree and puts out the aforementioned text file. The format of the text file is designed to enable the submission of the file as input to a spreadsheet program, wherein the forensic analysis is performed. The analysis usually consists of sorting files and examination of such characteristics of files as ownership, time of creation, and time of most recent access, all of which characteristics are among the data included in the text file.

  11. Nucleotide binding-promoted conformational changes release a nonnative polypeptide from the Escherichia coli chaperonin GroEL.

    PubMed Central

    Lin, Z; Eisenstein, E

    1996-01-01

    The Escherichia coli chaperonins GroEL and GroES facilitate the refolding of polypeptide chains in an ATP hydrolysis-dependent reaction. The elementary steps in the binding and release of polypeptide substrates to GroEL were investigated in surface plasmon resonance studies to measure the rates of binding and dissociation of a normative variant of subtilisin. The rate constants determined for GroEL association with and dissociation from this variant yielded a micromolar dissociation constant, in agreement with independent calorimetric estimates. The rate of GroEL dissociation from the nonnative chain was increased significantly in the presence of 5'-adenylylimidodiphosphate (AMP-PNP), ADP, and ATP, yielding maximal values between 0.04 and 0.22 s(-1). The sigmoidal dependence of the dissociation rate on the concentration of AMP-PNP and ADP indicated that polypeptide dissociation is limited by a concerted conformational change that occurs after nucleotide binding. The dependence of the rate of release on ATP exhibited two sigmoidal transitions attributable to nucleotide binding to the distal and proximal toroid of a GroEL-polypeptide chain complex. The addition of GroES resulted in a marked increase in the rate of nonnative polypeptide release from GroEL, indicating that the cochaperonin binds more rapidly than the dissociation of polypeptides. These data demonstrate the importance of nucleotide binding-promoted concerted conformational changes for the release of chains from GroEL, which correlate with the sigmoidal hydrolysis of ATP by the chaperonin. The implications of these findings are discussed in terms of a working hypothesis for a single cycle of chaperonin action. PMID:8700870

  12. The composition, structure and stability of a group II chaperonin are temperature regulated in a hyperthermophilic archaeon.

    PubMed

    Kagawa, Hiromi K; Yaoi, Takuro; Brocchieri, Luciano; McMillan, R Andrew; Alton, Thomas; Trent, Jonathan D

    2003-04-01

    The hyperthermoacidophilic archaeon Sulfolobus shibatae contains group II chaperonins, known as rosettasomes, which are two nine-membered rings composed of three different 60 kDa subunits (TF55 alpha, beta and gamma). We sequenced the gene for the gamma subunit and studied the temperature-dependent changes in alpha, beta and gamma expression, their association into rosettasomes and their phylogenetic relationships. Alpha and beta gene expression was increased by heat shock (30 min, 86 degrees C) and decreased by cold shock (30 min, 60 degrees C). Gamma expression was undetectable at heat shock temperatures and low at normal temperatures (75-79 degrees C), but induced by cold shock. Polyacrylamide gel electrophoresis indicated that in vitro alpha and beta subunits form homo-oligomeric rosettasomes, and mixtures of alpha, beta and gamma form hetero-oligomeric rosettasomes. Transmission electron microscopy revealed that beta homo-oligomeric rosettasomes and all hetero-oligomeric rosettasomes associate into filaments. In vivo rosettasomes were hetero-oligomeric with an average subunit ratio of 1alpha:1beta:0.1gamma in cultures grown at 75 degrees C, a ratio of 1alpha:3beta:1gamma in cultures grown at 60 degrees C and a ratio of 2alpha:3beta:0gamma after 86 degrees C heat shock. Using differential scanning calorimetry, we determined denaturation temperatures (Tm) for alpha, beta and gamma subunits of 95.7 degrees C, 96.7 degrees C and 80.5 degrees C, respectively, and observed that rosettasomes containing gamma were relatively less stable than those with alpha and/or beta only. We propose that, in vivo, the rosettasome structure is determined by the relative abundance of subunits and not by a fixed geometry. Furthermore, phylogenetic analyses indicate that archaeal chaperonin subunits underwent multiple duplication events within species (paralogy). The independent evolution of these paralogues raises the possibility that chaperonins have functionally diversified between

  13. Chaperonins GroEL and GroES: views from atomic force microscopy.

    PubMed Central

    Mou, J; Sheng, S; Ho, R; Shao, Z

    1996-01-01

    The Escherichia coli chaperonins, GroEL and GroES, as well as their complexes in the presence of a nonhydrolyzable nucleotide AMP-PNP, have been imaged with the atomic force microscope (AFM). We demonstrate that both GroEL and GroES that have been adsorbed to a mica surface can be resolved directly by the AFM in aqueous solution at room temperature. However, with glutaraldehyde fixation of already adsorbed molecules, the resolution of both GroEL and GroES was further improved, as all seven subunits were well resolved without any image processing. We also found that chemical fixation was necessary for the contact mode AFM to image GroEL/ES complexes, and in the AFM images. GroEL with GroES bound can be clearly distinguished from those without. The GroEL/ES complex was about 5 nm higher than GroEL alone, indicating a 2 nm upward movement of the apical domains of GroEL. Using a slightly larger probe force, unfixed GroEL could be dissected: the upper heptamer was removed to expose the contact surface of the two heptamers. These results clearly demonstrate the usefulness of cross-linking agents for the determination of molecular structures with the AFM. They also pave the way for using the AFM to study the structural basis for the function of GroE system and other molecular chaperones. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 PMID:8889197

  14. Identification, characterization, and expression of the BiP endoplasmic reticulum resident chaperonins in Pneumocystis carinii.

    PubMed Central

    Stedman, T T; Buck, G A

    1996-01-01

    We have isolated, characterized, and examined the expression of the genes encoding BiP endoplasmic reticulum (ER) resident chaperonins responsible for transport, maturation, and proper folding of membrane and secreted proteins from two divergent strains of Pneumocystis carinii. The BiP genes, Pcbip and Prbip, from the P. c. carinii (prototype) strain and the P. c. rattus (variant) strain, respectively, are single-copy genes that reside on chromosomes of approximately 330 and approximately 350 kbp. Both genes encode approximately 72.5-kDa proteins that are most homologous to BiP genes from other organisms and exhibit the amino-terminal signal peptides and carboxyl-terminal ER retention sequences that are hallmarks of BiP proteins. We established short-term P. carinii cultures to examine expression and induction of Pcbip in response to heat shock, glucose starvation, inhibition of protein transport or N-linked glycosylation, and other conditions known to affect proper transport, glycosylation, and maturation of membrane and secreted proteins. These studies indicated that Pcbip mRNA is constitutively expressed but induced under conditions known to induce BiP expression in other organisms. In contrast to mammalian BiP genes but like other fungal BiP genes, P. carinii BiP mRNA levels are induced by heat shock. Finally, the Prbip and Pcbip coding sequences surprisingly exhibit only approximately 83% DNA and approximately 90% amino acid sequence identity and show only limited conservation in noncoding flanking and intron sequences. Analyses of the P. carinii BiP gene sequences support inclusion of P. carinii among the fungi but suggest a large divergence and possible speciation among P. carinii strains infecting a given host. PMID:8890193

  15. 48 CFR 1432.610 - Compromising debts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Compromising debts. 1432.610 Section 1432.610 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Contract Debts 1432.610 Compromising debts. The CO may...

  16. 48 CFR 1432.610 - Compromising debts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Compromising debts. 1432.610 Section 1432.610 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Contract Debts 1432.610 Compromising debts. The CO may...

  17. Analysis of Atlanta Compromise School Desegregation Plan.

    ERIC Educational Resources Information Center

    Research Atlanta, Inc., GA.

    On February 22, 1973, attorneys for the National Association for the Advancement of Colored People and the Atlanta Board of Education filed a compromise desegregation plan with the U.S. District Court for the Northern District of Georgia. If the Court approves, this compromise will constitute the final desegregation plan for the Atlanta Public…

  18. 26 CFR 301.7122-1 - Compromises.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... for taxes, interest, or penalties. Unless the terms of the offer and acceptance expressly provide otherwise, acceptance of an offer to compromise a civil liability does not remit a criminal liability, nor does acceptance of an offer to compromise a criminal liability remit a civil liability. (b) Grounds...

  19. Clayton's compromises and the assisted dying debate.

    PubMed

    Parker, Malcolm

    2015-03-01

    Richard Huxtable has recently argued that while assisted dying has been both repeatedly condemned and commended, a compromise resolution is possible. Following critique of other purported solutions, he argues for a new legal offence of "compassionate killing" as a plausible compromise between supporters and opponents of legalised assisted dying, because it offers something of significance to both sides. However, it turns out that "compassionate killing" would leave both sides with insufficient net benefit for the proposal to qualify as a compromise between them. By analogy with another apparently intractable bioethical debate, concerning destructive embryo research, this column rejects Huxtable's solution as another "Clayton's compromise". True compromise is not possible in bioethical debates involving divisions over deeply held values and world views. Resolving such debates inevitably involves the substitution of one dominant world view with another.

  20. A Gradient of ATP Affinities Generates an Asymmetric Power Stroke Driving the Chaperonin TRIC/CCT Folding Cycle

    PubMed Central

    Reissmann, Stefanie; Joachimiak, Lukasz A.; Chen, Bryan; Meyer, Anne S.; Nguyen, Anthony; Frydman, Judith

    2012-01-01

    SUMMARY The eukaryotic chaperonin TRiC/CCT uses ATP cycling to fold many essential proteins that other chaperones cannot fold. This 1 MDa hetero-oligomer consists of two identical stacked rings assembled from eight paralogous subunits, each containing a conserved ATP-binding domain. Here, we report a dramatic asymmetry in the ATP utilization cycle of this ring-shaped chaperonin, despite its apparently symmetric architecture. Only four of the eight different subunits bind ATP at physiological concentrations. ATP binding and hydrolysis by the low-affinity subunits is fully dispensable for TRiC function in vivo. The conserved nucleotide-binding hierarchy among TRiC subunits is evolutionarily modulated through differential nucleoside contacts. Strikingly, high-and low-affinity subunits are spatially segregated within two contiguous hemispheres in the ring, generating an asymmetric power stroke that drives the folding cycle. This unusual mode of ATP utilization likely serves to orchestrate a directional mechanism underlying TRiC/CCT’s unique ability to fold complex eukaryotic proteins. PMID:23041314

  1. Regulation and sequence of the Synechococcus sp. strain PCC 7942 groESL operon, encoding a cyanobacterial chaperonin.

    PubMed Central

    Webb, R; Reddy, K J; Sherman, L A

    1990-01-01

    The molecular chaperonins such as GroEL are now widely regarded as essential components for the stabilization of integral membrane or secretory proteins before membrane insertion or translocation, as well as for the assembly of macromolecular complexes such as ribulose bisphosphate carboxylase-oxygenase. The groESL operon of Synechococcus sp. strain PCC 7942 was cloned as two independent lacZ-groEL translational fusions by immunoscreening a lambda ZAP genomic expression library and then sequenced. The derived amino acid sequences of the GroES and GroEL proteins demonstrated very high levels of amino acid identity with cognate chaperonins from bacteria and chloroplasts. The bicistronic 2.4-kilobase transcript from this operon, barely detectable in RNA preparations from cells grown at 30 degrees C, accumulated approximately 120-fold in preparations from cells grown for 20 min at 45 degrees C. Under these conditions, GroEL protein accumulated to 10-fold-higher levels. Primer extension analysis was used to identify a cyanobacterial heat shock promoter located at -81 base pairs from the groES initiation codon. The transcriptional -10 and -35 sequences differ slightly from Escherichia coli consensus heat shock promoter sequences. Images PMID:1975581

  2. Asp-52 in combination with Asp-398 plays a critical role in ATP hydrolysis of chaperonin GroEL.

    PubMed

    Koike-Takeshita, Ayumi; Mitsuoka, Kaoru; Taguchi, Hideki

    2014-10-24

    The Escherichia coli chaperonin GroEL is a double-ring chaperone that assists protein folding with the aid of GroES and ATP. Asp-398 in GroEL is known as one of the critical residues on ATP hydrolysis because GroEL(D398A) mutant is deficient in ATP hydrolysis (<2% of the wild type) but not in ATP binding. In the archaeal Group II chaperonin, another aspartate residue, Asp-52 in the corresponding E. coli GroEL, in addition to Asp-398 is also important for ATP hydrolysis. We investigated the role of Asp-52 in GroEL and found that ATPase activity of GroEL(D52A) and GroEL(D52A/D398A) mutants was ∼ 20% and <0.01% of wild-type GroEL, respectively, indicating that Asp-52 in E. coli GroEL is also involved in the ATP hydrolysis. GroEL(D52A/D398A) formed a symmetric football-shaped GroEL-GroES complex in the presence of ATP, again confirming the importance of the symmetric complex during the GroEL ATPase cycle. Notably, the symmetric complex of GroEL(D52A/D398A) was extremely stable, with a half-time of ∼ 150 h (∼ 6 days), providing a good model to characterize the football-shaped complex.

  3. CCT chaperonin complex is required for efficient delivery of anthrax toxin into the cytosol of host cells

    PubMed Central

    Slater, Louise H.; Hett, Erik C.; Clatworthy, Anne E.; Mark, Kevin G.; Hung, Deborah T.

    2013-01-01

    Bacterial toxins have evolved successful strategies for coopting host proteins to access the cytosol of host cells. Anthrax lethal factor (LF) enters the cytosol through pores in the endosomal membrane formed by anthrax protective antigen. Although in vitro models using planar lipid bilayers have shown that translocation can occur in the absence of cellular factors, recent studies using intact endosomes indicate that host factors are required for translocation in the cellular environment. In this study, we describe a high-throughput shRNA screen to identify host factors required for anthrax lethal toxin-induced cell death. The cytosolic chaperonin complex chaperonin containing t-complex protein 1 (CCT) was identified, and subsequent studies showed that CCT is required for efficient delivery of LF and related fusion proteins into the cytosol. We further show that knockdown of CCT inhibits the acid-induced delivery of LF and the fusion protein LFN-Bla (N terminal domain of LF fused to β-lactamase) across the plasma membrane of intact cells. Together, these results suggest that CCT is required for efficient delivery of enzymatically active toxin to the cytosol and are consistent with a direct role for CCT in translocation of LF through the protective antigen pore. PMID:23716698

  4. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography*

    PubMed Central

    Darrow, Michele C.; Sergeeva, Oksana A.; Isas, Jose M.; Galaz-Montoya, Jesús G.; King, Jonathan A.; Langen, Ralf; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain. PMID:25995452

  5. The chaperonin CCT inhibits assembly of α-synuclein amyloid fibrils by a specific, conformation-dependent interaction

    PubMed Central

    Sot, Begoña; Rubio-Muñoz, Alejandra; Leal-Quintero, Ahudrey; Martínez-Sabando, Javier; Marcilla, Miguel; Roodveldt, Cintia; Valpuesta, José M.

    2017-01-01

    The eukaryotic chaperonin CCT (chaperonin containing TCP-1) uses cavities built into its double-ring structure to encapsulate and to assist folding of a large subset of proteins. CCT can inhibit amyloid fibre assembly and toxicity of the polyQ extended mutant of huntingtin, the protein responsible for Huntington’s disease. This raises the possibility that CCT modulates other amyloidopathies, a still-unaddressed question. We show here that CCT inhibits amyloid fibre assembly of α-synuclein A53T, one of the mutants responsible for Parkinson’s disease. We evaluated fibrillation blockade in α-synuclein A53T deletion mutants and CCT interactions of full-length A53T in distinct oligomeric states to define an inhibition mechanism specific for α-synuclein. CCT interferes with fibre assembly by interaction of its CCTζ and CCTγ subunits with the A53T central hydrophobic region (NAC). This interaction is specific to NAC conformation, as it is produced once soluble α-synuclein A53T oligomers form and blocks the reaction before fibres begin to grow. Finally, we show that this association inhibits α-synuclein A53T oligomer toxicity in neuroblastoma cells. In summary, our results and those for huntingtin suggest that CCT is a general modulator of amyloidogenesis via a specific mechanism. PMID:28102321

  6. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography.

    PubMed

    Darrow, Michele C; Sergeeva, Oksana A; Isas, Jose M; Galaz-Montoya, Jesús G; King, Jonathan A; Langen, Ralf; Schmid, Michael F; Chiu, Wah

    2015-07-10

    Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼ 1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. The chaperonin CCT inhibits assembly of α-synuclein amyloid fibrils by a specific, conformation-dependent interaction.

    PubMed

    Sot, Begoña; Rubio-Muñoz, Alejandra; Leal-Quintero, Ahudrey; Martínez-Sabando, Javier; Marcilla, Miguel; Roodveldt, Cintia; Valpuesta, José M

    2017-01-19

    The eukaryotic chaperonin CCT (chaperonin containing TCP-1) uses cavities built into its double-ring structure to encapsulate and to assist folding of a large subset of proteins. CCT can inhibit amyloid fibre assembly and toxicity of the polyQ extended mutant of huntingtin, the protein responsible for Huntington's disease. This raises the possibility that CCT modulates other amyloidopathies, a still-unaddressed question. We show here that CCT inhibits amyloid fibre assembly of α-synuclein A53T, one of the mutants responsible for Parkinson's disease. We evaluated fibrillation blockade in α-synuclein A53T deletion mutants and CCT interactions of full-length A53T in distinct oligomeric states to define an inhibition mechanism specific for α-synuclein. CCT interferes with fibre assembly by interaction of its CCTζ and CCTγ subunits with the A53T central hydrophobic region (NAC). This interaction is specific to NAC conformation, as it is produced once soluble α-synuclein A53T oligomers form and blocks the reaction before fibres begin to grow. Finally, we show that this association inhibits α-synuclein A53T oligomer toxicity in neuroblastoma cells. In summary, our results and those for huntingtin suggest that CCT is a general modulator of amyloidogenesis via a specific mechanism.

  8. Chaperonin 20 might be an iron chaperone for superoxide dismutase in activating iron superoxide dismutase (FeSOD)

    PubMed Central

    Kuo, Wen-Yu; Huang, Chien-Hsun; Jinn, Tsung-Luo

    2013-01-01

    Activation of Cu/Zn superoxide dismutases (CuZnSODs) is aided by Cu incorporation and disulfide isomerization by Cu chaperone of SOD (CCS). As well, an Fe-S cluster scaffold protein, ISU, might alter the incorporation of Fe or Mn into yeast MnSOD (ySOD2), thus leading to active or inactive ySOD2. However, metallochaperones involved in the activation of FeSODs are unknown. Recently, we found that a chloroplastic chaperonin cofactor, CPN20, could mediate FeSOD activity. To investigate whether Fe incorporation in FeSOD is affected by CPN20, we used inductively coupled plasma mass spectrometry to analyze the ability of CPN20 to bind Fe. CPN20 could bind Fe, and the Fe binding to FeSOD was increased with CPN20 incubation. Thus, CPN20 might be an Fe chaperone for FeSOD activation, a role independent of its well-known co-chaperonin activity. PMID:23299425

  9. The Cpn10(1) Co-Chaperonin of A. thaliana Functions Only as a Hetero-Oligomer with Cpn20

    PubMed Central

    Vitlin Gruber, Anna; Zizelski, Gal; Azem, Abdussalam; Weiss, Celeste

    2014-01-01

    The A. thaliana genome encodes five co-chaperonin homologs, three of which are destined to the chloroplast. Two of the proteins, Cpn10(2) and Cpn20, form functional homo-oligomers in vitro. In the current work, we present data on the structure and function of the third A. thaliana co-chaperonin, which exhibits unique properties. We found that purified recombinant Cpn10(1) forms inactive dimers in solution, in contrast to the active heptamers that are formed by canonical Cpn10s. Additionally, our data demonstrate that Cpn10(1) is capable of assembling into active hetero-oligomers together with Cpn20. This finding was reinforced by the formation of active co-chaperonin species upon mixing an inactive Cpn20 mutant with the inactive Cpn10(1). The present study constitutes the first report of a higher plant Cpn10 subunit that is able to function only upon formation of hetero-oligomers with other co-chaperonins. PMID:25419702

  10. Obesity May Not Compromise Knee Surgery Success

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_164282.html Obesity May Not Compromise Knee Surgery Success Results similar ... over 35, so it's unclear if more severe obesity might increase the risk of meniscal repair failure, ...

  11. Bardet-Biedl Syndrome as a Chaperonopathy: Dissecting the Major Role of Chaperonin-Like BBS Proteins (BBS6-BBS10-BBS12)

    PubMed Central

    Álvarez-Satta, María; Castro-Sánchez, Sheila; Valverde, Diana

    2017-01-01

    Bardet-Biedl syndrome (BBS) is a rare genetic disorder that belongs to the group of ciliopathies, defined as diseases caused by defects in cilia structure and/or function. The six diagnostic features considered for this syndrome include retinal dystrophy, obesity, polydactyly, cognitive impairment and renal and urogenital anomalies. Furthermore, three of the 21 genes currently known to be involved in BBS encode chaperonin-like proteins (MKKS/BBS6, BBS10, and BBS12), so BBS can be also considered a member of the growing group of chaperonopathies. Remarkably, up to 50% of clinically-diagnosed BBS families can harbor disease-causing variants in these three genes, which highlights the importance of chaperone defects as pathogenic factors even for genetically heterogeneous syndromes such as BBS. In addition, it is interesting to note that BBS families with deleterious variants in MKKS/BBS6, BBS10 or BBS12 genes generally display more severe phenotypes than families with changes in other BBS genes. The chaperonin-like BBS proteins have structural homology to the CCT family of group II chaperonins, although they are believed to conserve neither the ATP-dependent folding activity of canonical CCT chaperonins nor the ability to form CCT-like oligomeric complexes. Thus, they play an important role in the initial steps of assembly of the BBSome, which is a multiprotein complex essential for mediating the ciliary trafficking activity. In this review, we present a comprehensive review of those genetic, functional and evolutionary aspects concerning chaperonin-like BBS proteins, trying to provide a new perspective that expands the classical conception of BBS only from a ciliary point of view. PMID:28824921

  12. Chaperonins induce an amyloid-like transformation of ovine prion protein: the fundamental difference in action between eukaryotic TRiC and bacterial GroEL.

    PubMed

    Kiselev, Georgy G; Naletova, Irina N; Sheval, Evgeny V; Stroylova, Yulia Y; Schmalhausen, Elena V; Haertlé, Thomas; Muronetz, Vladimir I

    2011-12-01

    Molecular chaperones have been shown to be involved in the processes taking place during the pathogenesis of various amyloid neurodegenerative diseases. However, contradictory literature reports suggest that different molecular chaperones can either stimulate or prevent the formation of amyloid structures from distinct amyloidogenic proteins. In the present work, we concentrated on the effects caused by two molecular chaperonins, ovine TRiC and bacterial GroEL, on the aggregation and conformational state of ovine PrP. Both chaperonins were shown to bind native PrP and to produce amyloid-like forms of ovine PrP enriched with beta-structures but, while GroEL acted in an ATP-dependent manner, TRiC was shown to cause the same effect only in the absence of Mg-ATP (i.e. in the inactive form). In the presence of chaperonin GroEL, ovine PrP was shown to form micellar particles, approximately 100-200nm in diameter, which were observed both by dynamic light scattering assay and by electron microscopy. The content of these particles was significantly higher in the presence of Mg-ATP and, only under these conditions, GroEL produced amyloid-like species enriched with beta-structures. TRiC was shown to induce the formation of amyloid fibrils observed by electron microscopy, but only in the absence of Mg-ATP. This study suggests the important role of the cytosolic chaperonin TRiC in the propagation of amyloid structures in vivo during the development of amyloid diseases and the possible role of the bacterial chaperonin GroEL, located in the intestinal microflora, in the induction of these diseases.

  13. The interaction of the chaperonin tailless complex polypeptide 1 (TCP1) ring complex (TRiC) with ribosome-bound nascent chains examined using photo-cross-linking.

    PubMed

    McCallum, C D; Do, H; Johnson, A E; Frydman, J

    2000-05-01

    The eukaryotic chaperonin tailless complex polypeptide 1 (TCP1) ring complex (TRiC) (also called chaperonin containing TCP1 [CCT]) is a hetero-oligomeric complex that facilitates the proper folding of many cellular proteins. To better understand the manner in which TRiC interacts with newly translated polypeptides, we examined its association with nascent chains using a photo-cross-linking approach. To this end, a series of ribosome-bound nascent chains of defined lengths was prepared using truncated mRNAs. Photoactivatable probes were incorporated into these (35)S- labeled nascent chains during translation. Upon photolysis, TRiC was cross-linked to ribosome-bound polypeptides exposing at least 50-90 amino acids outside the ribosomal exit channel, indicating that the chaperonin associates with much shorter nascent chains than indicated by previous studies. Cross-links were observed for nascent chains of the cytosolic proteins actin, luciferase, and enolase, but not to ribosome-bound preprolactin. The pattern of cross-links became more complex as the nascent chain increased in length. These results suggest a chain length-dependent increase in the number of TRiC subunits involved in the interaction that is consistent with the idea that the substrate participates in subunit-specific contacts with the chaperonin. Both ribosome isolation by centrifugation through sucrose cushions and immunoprecipitation with anti-puromycin antibodies demonstrated that the photoadducts form on ribosome-bound polypeptides. Our results indicate that TRiC/CCT associates with the translating polypeptide shortly after it emerges from the ribosome and suggest a close association between the chaperonin and the translational apparatus.

  14. 45 CFR 30.22 - Bases for compromise.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Bases for compromise. 30.22 Section 30.22 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CLAIMS COLLECTION Debt Compromise § 30.22 Bases for compromise. (a) Compromise. The Secretary may compromise a debt if the full...

  15. 45 CFR 30.22 - Bases for compromise.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Bases for compromise. 30.22 Section 30.22 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION CLAIMS COLLECTION Debt Compromise § 30.22 Bases for compromise. (a) Compromise. The Secretary may compromise a debt if the full...

  16. 45 CFR 30.22 - Bases for compromise.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Bases for compromise. 30.22 Section 30.22 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CLAIMS COLLECTION Debt Compromise § 30.22 Bases for compromise. (a) Compromise. The Secretary may compromise a debt if the full...

  17. 45 CFR 30.22 - Bases for compromise.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Bases for compromise. 30.22 Section 30.22 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CLAIMS COLLECTION Debt Compromise § 30.22 Bases for compromise. (a) Compromise. The Secretary may compromise a debt if the full...

  18. Vascular Compromise from Soft Tissue Augmentation

    PubMed Central

    Humphrey, Shannon; Carruthers, Jean D.A.; Carruthers, Alastair

    2014-01-01

    The popularity of soft tissue fillers is, in part, due to their favorable side-effect profile. However, serious complications can occur. The authors describe their extensive clinical experience with soft-tissue augmentation and the rare complication of vascular compromise, which can lead to necrosis and scarring. Over a 10-year period between January 2003 and January 2013, the authors observed a total of 12 cases of vascular compromise. Eight patients in their clinical practice showed evidence of vascular compromise out of a total of 14,355 filler injections (0.05%). In addition, four patients treated with an experimental particulate filler had vascular complications. All cases were examined for filler type, location of complication, risk factors, treatment, and outcomes. Although treatment plans differed for each patient in their series, all cases of vascular compromise resolved fully. The authors believe that an office-based protocol for both immediate and ongoing care—including a thorough individualized assessment and treatment plan for each patient—is critical to timely and effective resolution of side effects. They propose key recommendations for the prevention and management of vascular compromise to improve patient outcomes and reduce the risk of permanent complications. PMID:25276276

  19. Folding of newly translated membrane protein CCR5 is assisted by the chaperonin GroEL-GroES

    NASA Astrophysics Data System (ADS)

    Chi, Haixia; Wang, Xiaoqiang; Li, Jiqiang; Ren, Hao; Huang, Fang

    2015-11-01

    The in vitro folding of newly translated human CC chemokine receptor type 5 (CCR5), which belongs to the physiologically important family of G protein-coupled receptors (GPCRs), has been studied in a cell-free system supplemented with the surfactant Brij-35. The freshly synthesized CCR5 can spontaneously fold into its biologically active state but only slowly and inefficiently. However, on addition of the GroEL-GroES molecular chaperone system, the folding of the nascent CCR5 was significantly enhanced, as was the structural stability and functional expression of the soluble form of CCR5. The chaperonin GroEL was partially effective on its own, but for maximum efficiency both the GroEL and its GroES lid were necessary. These results are direct evidence for chaperone-assisted membrane protein folding and therefore demonstrate that GroEL-GroES may be implicated in the folding of membrane proteins.

  20. Purification and characterization of chaperonin 60 and heat-shock protein 70 from chromoplasts of Narcissus pseudonarcissus.

    PubMed Central

    Bonk, M; Tadros, M; Vandekerckhove, J; Al-Babili, S; Beyer, P

    1996-01-01

    In chromoplast differentiation during flower formation in Narcissus pseudonarcissus, the molecular chaperones chaperonin 60 (Cpn60; alpha and beta) and heat-shock protein 70 (Hsp70) greatly increase in abundance. Both were purified and shown to be present in a functional form in chromoplasts, indicating their requirement in the extensive structural rearrangements during the chloroplast-to-chromoplast transition. The purified proteins, sequenced N terminally and from internal peptides, showed strong homology to plastid Cpn60 and Hsp 70 representatives from other plant species. During chromoplast differentiation, the carotenoid biosynthetic pathway is strongly induced. The corresponding enzymes are all nuclear encoded and form a large, soluble, hetero-oligomeric protein complex after import but prior to their membrane attachment. By immunoprecipitations we have shown that the plastid Hsp70 is a structural constituent of a soluble entity also containing phytoene desaturase. PMID:8754688

  1. Folding of newly translated membrane protein CCR5 is assisted by the chaperonin GroEL-GroES.

    PubMed

    Chi, Haixia; Wang, Xiaoqiang; Li, Jiqiang; Ren, Hao; Huang, Fang

    2015-11-20

    The in vitro folding of newly translated human CC chemokine receptor type 5 (CCR5), which belongs to the physiologically important family of G protein-coupled receptors (GPCRs), has been studied in a cell-free system supplemented with the surfactant Brij-35. The freshly synthesized CCR5 can spontaneously fold into its biologically active state but only slowly and inefficiently. However, on addition of the GroEL-GroES molecular chaperone system, the folding of the nascent CCR5 was significantly enhanced, as was the structural stability and functional expression of the soluble form of CCR5. The chaperonin GroEL was partially effective on its own, but for maximum efficiency both the GroEL and its GroES lid were necessary. These results are direct evidence for chaperone-assisted membrane protein folding and therefore demonstrate that GroEL-GroES may be implicated in the folding of membrane proteins.

  2. Folding of newly translated membrane protein CCR5 is assisted by the chaperonin GroEL-GroES

    PubMed Central

    Chi, Haixia; Wang, Xiaoqiang; Li, Jiqiang; Ren, Hao; Huang, Fang

    2015-01-01

    The in vitro folding of newly translated human CC chemokine receptor type 5 (CCR5), which belongs to the physiologically important family of G protein-coupled receptors (GPCRs), has been studied in a cell-free system supplemented with the surfactant Brij-35. The freshly synthesized CCR5 can spontaneously fold into its biologically active state but only slowly and inefficiently. However, on addition of the GroEL-GroES molecular chaperone system, the folding of the nascent CCR5 was significantly enhanced, as was the structural stability and functional expression of the soluble form of CCR5. The chaperonin GroEL was partially effective on its own, but for maximum efficiency both the GroEL and its GroES lid were necessary. These results are direct evidence for chaperone-assisted membrane protein folding and therefore demonstrate that GroEL-GroES may be implicated in the folding of membrane proteins. PMID:26585937

  3. Chaperonin-containing TCP-1 complex directly binds to the cytoplasmic domain of the LOX-1 receptor

    PubMed Central

    Bakthavatsalam, Deenadayalan; Soung, Roh Hun; Tweardy, David J.; Chiu, Wah; Dixon, Richard A.F.; Woodside, Darren G.

    2014-01-01

    Lectin-like oxidized low-density lipoprotein receptor (LOX-1) is a scavenger receptor that binds oxidized low-density lipoprotein (OxLDL) and has a role in atherosclerosis development. The N-terminus intracellular region (cytoplasmic domain) of LOX-1 mediates receptor internalization and trafficking, potentially through intracellular protein interactions. Using affinity isolation, we identified 6 of the 8 components of the chaperonin-containing TCP-1 (CCT) complex bound to LOX-1 cytoplasmic domain, which we verified by coimmunoprecipitation and immunostaining in human umbilical vein endothelial cells. We found that the interaction between CCT and LOX-1 is direct and ATP-dependent and that OxLDL suppressed this interaction. Understanding the association between LOX-1 and the CCT complex may facilitate the design of novel therapies for cardiovascular disease. PMID:24846140

  4. Chaperonin-containing TCP-1 complex directly binds to the cytoplasmic domain of the LOX-1 receptor.

    PubMed

    Bakthavatsalam, Deenadayalan; Soung, Roh Hun; Tweardy, David J; Chiu, Wah; Dixon, Richard A F; Woodside, Darren G

    2014-06-13

    Lectin-like oxidized low-density lipoprotein receptor (LOX-1) is a scavenger receptor that binds oxidized low-density lipoprotein (OxLDL) and has a role in atherosclerosis development. The N-terminus intracellular region (cytoplasmic domain) of LOX-1 mediates receptor internalization and trafficking, potentially through intracellular protein interactions. Using affinity isolation, we identified 6 of the 8 components of the chaperonin-containing TCP-1 (CCT) complex bound to LOX-1 cytoplasmic domain, which we verified by coimmunoprecipitation and immunostaining in human umbilical vein endothelial cells. We found that the interaction between CCT and LOX-1 is direct and ATP-dependent and that OxLDL suppressed this interaction. Understanding the association between LOX-1 and the CCT complex may facilitate the design of novel therapies for cardiovascular disease.

  5. The theory of compromised eating behavior.

    PubMed

    Furman, Ellen

    2014-01-01

    The purpose of this inquiry was to develop substantive theory that describes the social process that influences the eating behavior of hospitalized older adults. Undernutrition contributes to negative health outcomes, such as increased morbidity and mortality in hospitalized older adults. Despite the availability of vast nutritional resources within the hospital environment, hospitalized older adults often have inadequate dietary intake. A grounded theory methodology was used to explore this phenomenon. The Theory of Compromised Eating Behavior describes the process of compromise that older adults experience related to eating behavior while hospitalized. The theory has four stages: self-indication, joint action, negotiation, and action. The meaning of hospital food and mealtimes differs from at-home food and mealtimes for the older adult, resulting in compromise. Intervention, which enhances the meaning of food and mealtimes for the older adult during hospitalization, may improve dietary intake and nutritional outcomes.

  6. Modeling the Dynamics of Compromised Networks

    SciTech Connect

    Soper, B; Merl, D M

    2011-09-12

    Accurate predictive models of compromised networks would contribute greatly to improving the effectiveness and efficiency of the detection and control of network attacks. Compartmental epidemiological models have been applied to modeling attack vectors such as viruses and worms. We extend the application of these models to capture a wider class of dynamics applicable to cyber security. By making basic assumptions regarding network topology we use multi-group epidemiological models and reaction rate kinetics to model the stochastic evolution of a compromised network. The Gillespie Algorithm is used to run simulations under a worst case scenario in which the intruder follows the basic connection rates of network traffic as a method of obfuscation.

  7. Air Duster abuse causing rapid airway compromise.

    PubMed

    Winston, Amanda; Kanzy, Abed; Bachuwa, Ghassan

    2015-01-07

    Inhalant abuse is potentially life-threatening and has resulted in many complications such as central nervous system depression, cardiac dysrhythmia and hypoxia. Inhalant abuse causing angioedema is rarely reported in the medical literature. In this report we present a case of rapidly progressive airway compromise following recreational huffing. Our patient required intubation and intensive care unit admission with complete recovery after 5 days. The aetiology of airway compromise is postulated to be due to commonly reported frost bite injury and rarely reported angioedema. To the best of our knowledge this the second case reporting angioedema secondary to huffing Air Duster. 2015 BMJ Publishing Group Ltd.

  8. Funhaler spacer: improving adherence without compromising delivery

    PubMed Central

    Watt, P; Clements, B; Devadason, S; Chaney, G

    2003-01-01

    A novel asthma spacer device, the "Funhaler", incorporates incentive toys which are isolated from the main inspiratory circuit by a valve. Here we show that its use does not compromise drug delivery. Improved adherence combined with satisfactory delivery characteristics suggest that the Funhaler may be useful for management of young asthmatics. PMID:12818901

  9. Uneasy Compromise: Language and Education in Moldova

    ERIC Educational Resources Information Center

    Ciscel, Matthew

    2008-01-01

    This study reports on the uneasy compromise in language and education policies in the post-Soviet Republic of Moldova since its first moves toward independence in 1989. Taking an approach that posits language policies as needing to be anchored in both international norms and the idiosyncrasies of local conditions, the discussion explores the…

  10. Political Compromise Makes the World Go 'Round

    ERIC Educational Resources Information Center

    Everett, Diana

    2007-01-01

    Compromise in any context is often hard to accept. It feels like a person is giving up on his or her ideals. This is especially true in dealing with politics. Legislative and congressional bills can be written with the highest of ideals in mind. By the time the bill progresses through committees and the floor debate process, it can look like a…

  11. Characterization of Protein and Transcript Levels of the Chaperonin Containing Tailless Complex Protein-1 and Tubulin during Light-Regulated Growth of Oat Seedlings1

    PubMed Central

    Moser, Michael; Schäfer, Eberhard; Ehmann, Bruno

    2000-01-01

    In grass seedlings the network of cortical microtubules is reorganized during light-dependent growth of coleoptiles and mesocotyls. We investigated the effects of light-dependent growth on the relative steady-state levels of the mRNAs and protein levels of α-tubulin and the ε-subunit of the chaperonin containing tailless complex protein-1 in oat (Avena sativa) coleoptiles, which were grown in different light conditions to establish different growth responses. The soluble pools of the ε-subunit of the chaperonin containing tailless complex protein-1 and α-tubulin decreased in nonelongating coleoptiles, suggesting that the dynamics of the light-regulated soluble pool reflect the processes occurring during reorganization of cortical microtubules. The shifts in pool sizes are discussed in relation to the machinery that controls the dynamic structure of cortical microtubules in plant cells. PMID:10982445

  12. 19 CFR 172.33 - Acceptance of offers in compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Acceptance of offers in compromise. 172.33 Section... OF THE TREASURY (CONTINUED) CLAIMS FOR LIQUIDATED DAMAGES; PENALTIES SECURED BY BONDS Offers in Compromise § 172.33 Acceptance of offers in compromise. An offer in compromise will be considered...

  13. 19 CFR 171.32 - Acceptance of offers in compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Acceptance of offers in compromise. 171.32 Section... OF THE TREASURY (CONTINUED) FINES, PENALTIES, AND FORFEITURES Offers in Compromise § 171.32 Acceptance of offers in compromise. An offer in compromise will be considered accepted only when the...

  14. Radiosurgical planning of meningiomas: compromises with conformity.

    PubMed

    Rowe, Jeremy G; Walton, Lee; Vaughan, Paul; Malik, Irfan; Radatz, Matthias; Kemeny, Andras

    2004-01-01

    The radiosurgical planning of meningiomas frequently necessitates compromises between irradiating tumour and risking damage to adjacent structures. In selected cases, we resolved this by excluding part of the tumour from the prescription isodose volume. Most of these compromises or 'suboptimal' plans achieved growth control. Growth control could not be related to conformity indices or to various measures of the radiation dose received by the meningioma. Examining recurrences, 75% arose from dura outside the original treatment field. These findings are discussed in terms of dose prescription protocols and the use of conformity indices in planning. The importance of the dural origin of meningiomas is well established in surgical practice, as reflected by Simpson's grades, but may be equally significant in radiosurgical practice.

  15. Expression Profiles and Physiological Roles of Two Types of Molecular Chaperonins from the Hyperthermophilic Archaeon Thermococcus kodakarensis▿ †

    PubMed Central

    Fujiwara, Shinsuke; Aki, Ryohei; Yoshida, Masaya; Higashibata, Hiroki; Imanaka, Tadayuki; Fukuda, Wakao

    2008-01-01

    Thermococcus kodakarensis possesses two chaperonins, CpkA and CpkB, and their expression is induced by the downshift and upshift, respectively, of the cell cultivation temperature. The expression levels of the chaperonins were examined by using specific antibodies at various cell growth temperatures in the logarithmic and stationary phases. At 60°C, CpkA was highly expressed in both the logarithmic and stationary phases; however, CpkB was not expressed in either phase. At 85°C, CpkA and CpkB were expressed in both phases; however, the CpkA level was decreased in the stationary phase. At 93°C, CpkA was expressed only in the logarithmic phase and not in the stationary phase. In contrast, CpkB was highly expressed in both phases. The results of reverse transcription-PCR experiments showed the same growth phase- and temperature-dependent profiles as observed in immunoblot analyses, indicating that the expression of cpkA and cpkB is regulated at the mRNA level. The cpkA or cpkB gene disruptant was then constructed, and its growth profile was monitored. The cpkA disruptant showed poor cell growth at 60°C but no significant defects at 85°C and 93°C. On the other hand, cpkB disruption led to growth defects at 93°C but no significant defects at 60°C and 85°C. These data indicate that CpkA and CpkB are necessary for cell growth at lower and higher temperatures, respectively. The logarithmic-phase-dependent expression of CpkA at 93°C suggested that CpkA participates in initial cell growth in addition to lower-temperature adaptation. Promoter mapping and quantitative analyses using the Phr (Pyrococcus heat-shock regulator) gene disruptant revealed that temperature-dependent expression was achieved in a Phr-independent manner. PMID:18835998

  16. Cloning, characterization and sub-cellular localization of gamma subunit of T-complex protein-1 (chaperonin) from Leishmania donovani

    SciTech Connect

    Bhaskar,; Kumari, Neeti; Goyal, Neena

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer The study presents cloning and characterization of TCP1{gamma} gene from L. donovani. Black-Right-Pointing-Pointer TCP1{gamma} is a subunit of T-complex protein-1 (TCP1), a chaperonin class of protein. Black-Right-Pointing-Pointer LdTCP{gamma} exhibited differential expression in different stages of promastigotes. Black-Right-Pointing-Pointer LdTCP{gamma} co-localized with actin, a cytoskeleton protein. Black-Right-Pointing-Pointer The data suggests that this gene may have a role in differentiation/biogenesis. Black-Right-Pointing-Pointer First report on this chapronin in Leishmania. -- Abstract: T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1{gamma}), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1{gamma} of Leishmania donovani (LdTCP1{gamma}), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1{gamma} revealed the presence of all the characteristic features of TCP1{gamma}. However, leishmanial TCP1{gamma} represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1{gamma} exhibited differential expression in different stages of promastigotes. The non-dividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1{gamma} as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1{gamma} was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, peri-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1{gamma} with actin suggests

  17. Mitochondrial Hsp60 Chaperonopathy Causes an Autosomal-Recessive Neurodegenerative Disorder Linked to Brain Hypomyelination and Leukodystrophy

    PubMed Central

    Magen, Daniella; Georgopoulos, Costa; Bross, Peter; Ang, Debbie; Segev, Yardena; Goldsher, Dorit; Nemirovski, Alexandra; Shahar, Eli; Ravid, Sarit; Luder, Anthony; Heno, Bayan; Gershoni-Baruch, Ruth; Skorecki, Karl; Mandel, Hanna

    2008-01-01

    Hypomyelinating leukodystrophies (HMLs) are disorders involving aberrant myelin formation. The prototype of primary HMLs is the X-linked Pelizaeus-Merzbacher disease (PMD) caused by mutations in PLP1. Recently, homozygous mutations in GJA12 encoding connexin 47 were found in patients with autosomal-recessive Pelizaeus-Merzbacher-like disease (PMLD). However, many patients of both genders with PMLD carry neither PLP1 nor GJA12 mutations. We report a consanguineous Israeli Bedouin kindred with clinical and radiological findings compatible with PMLD, in which linkage to PLP1 and GJA12 was excluded. Using homozygosity mapping and mutation analysis, we have identified a homozygous missense mutation (D29G) not previously described in HSPD1, encoding the mitochondrial heat-shock protein 60 (Hsp60) in all affected individuals. The D29G mutation completely segregates with the disease-associated phenotype. The pathogenic effect of D29G on Hsp60-chaperonin activity was verified by an in vivo E. coli complementation assay, which demonstrated compromised ability of the D29G-Hsp60 mutant protein to support E. coli survival, especially at high temperatures. The disorder, which we have termed MitCHAP-60 disease, can be distinguished from spastic paraplegia 13 (SPG13), another Hsp60-associated autosomal-dominant neurodegenerative disorder, by its autosomal-recessive inheritance pattern, as well as by its early-onset, profound cerebral involvement and lethality. Our findings suggest that Hsp60 defects can cause neurodegenerative pathologies of varying severity, not previously suspected on the basis of the SPG13 phenotype. These findings should help to clarify the important role of Hsp60 in myelinogenesis and neurodegeneration. PMID:18571143

  18. Intrinsic unfoldase/foldase activity of the chaperonin GroEL directly demonstrated using multinuclear relaxation-based NMR

    PubMed Central

    Libich, David S.; Tugarinov, Vitali; Clore, G. Marius

    2015-01-01

    The prototypical chaperonin GroEL assists protein folding through an ATP-dependent encapsulation mechanism. The details of how GroEL folds proteins remain elusive, particularly because encapsulation is not an absolute requirement for successful re/folding. Here we make use of a metastable model protein substrate, comprising a triple mutant of Fyn SH3, to directly demonstrate, by simultaneous analysis of three complementary NMR-based relaxation experiments (lifetime line broadening, dark state exchange saturation transfer, and Carr–Purcell–Meinboom–Gill relaxation dispersion), that apo GroEL accelerates the overall interconversion rate between the native state and a well-defined folding intermediate by about 20-fold, under conditions where the “invisible” GroEL-bound states have occupancies below 1%. This is largely achieved through a 500-fold acceleration in the folded-to-intermediate transition of the protein substrate. Catalysis is modulated by a kinetic deuterium isotope effect that reduces the overall interconversion rate between the GroEL-bound species by about 3-fold, indicative of a significant hydrophobic contribution. The location of the GroEL binding site on the folding intermediate, mapped from 15N, 1HN, and 13Cmethyl relaxation dispersion experiments, is composed of a prominent, surface-exposed hydrophobic patch. PMID:26124125

  19. Repetitive Protein Unfolding by the trans Ring of the GroEL-GroES Chaperonin Complex Stimulates Folding*

    PubMed Central

    Lin, Zong; Puchalla, Jason; Shoup, Daniel; Rye, Hays S.

    2013-01-01

    A key constraint on the growth of most organisms is the slow and inefficient folding of many essential proteins. To deal with this problem, several diverse families of protein folding machines, known collectively as molecular chaperones, developed early in evolutionary history. The functional role and operational steps of these remarkably complex nanomachines remain subjects of active debate. Here we present evidence that, for the GroEL-GroES chaperonin system, the non-native substrate protein enters the folding cycle on the trans ring of the double-ring GroEL-ATP-GroES complex rather than the ADP-bound complex. The properties of this ATP complex are designed to ensure that non-native substrate protein binds first, followed by ATP and finally GroES. This binding order ensures efficient occupancy of the open GroEL ring and allows for disruption of misfolded structures through two phases of multiaxis unfolding. In this model, repeated cycles of partial unfolding, followed by confinement within the GroEL-GroES chamber, provide the most effective overall mechanism for facilitating the folding of the most stringently dependent GroEL substrate proteins. PMID:24022487

  20. A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae

    PubMed Central

    Kaufman, Brett A.; Kolesar, Jill E.; Perlman, Philip S.; Butow, Ronald A.

    2003-01-01

    The yeast mitochondrial chaperonin Hsp60 has previously been implicated in mitochondrial DNA (mtDNA) transactions: it is found in mtDNA nucleoids associated with single-stranded DNA; it binds preferentially to the template strand of active mtDNA ori sequences in vitro; and wild-type (ρ+) mtDNA is unstable in hsp60 temperature-sensitive (ts) mutants grown at the permissive temperature. Here we show that the mtDNA instability is caused by a defect in mtDNA transmission to daughter cells. Using high resolution, fluorescence deconvolution microscopy, we observe a striking alteration in the morphology of mtDNA nucleoids in ρ+ cells of an hsp60-ts mutant that suggests a defect in nucleoid division. We show that ρ− petite mtDNA consisting of active ori repeats is uniquely unstable in the hsp60-ts mutant. This instability of ori ρ− mtDNA requires transcription from the canonical promoter within the ori element. Our data suggest that the nucleoid dynamics underlying mtDNA transmission are regulated by the interaction between Hsp60 and mtDNA ori sequences. PMID:14597775

  1. Interactions between a luteovirus and the GroEL chaperonin protein of the symbiotic bacterium Buchnera aphidicola of aphids.

    PubMed

    Bouvaine, Sophie; Boonham, Neil; Douglas, Angela E

    2011-06-01

    Luteoviruses and poleroviruses are important plant viruses transmitted exclusively by aphids in a circulative manner via the aphid haemolymph. A chaperonin protein, GroEL, synthesized in aphids by a symbiotic bacterium, Buchnera aphidicola, is hypothesized to bind to virus particles in the haemolymph, thereby promoting transmission. To investigate this hypothesis, the GroEL-binding site for barley yellow dwarf virus (BYDV) was determined in vitro, and the abundance of GroEL protein in different aphid tissues was investigated. Virus binding to a peptide library representing the full GroEL molecule revealed a single binding site that coincides with the site that anchors two GroEL rings to form the native GroEL tetradecamer. In the functional form of the GroEL protein, virus binding would compete with the formation of the two GroEL rings. Using a mAb raised against a Buchnera-specific GroEL epitope, GroEL was detected in Buchnera cells by immunoblotting and immunocytochemistry, but not in the aphid haemolymph, fat body or gut. From the prediction here that GroEL-virus interactions are probably severely limited by competition with other GroEL molecules, and the evidence that GroEL is not available to interact with virus particles in vivo, it is concluded that GroEL-virus interactions are unlikely to contribute to virus transmission by aphids.

  2. Chaperonin Contributes to Cold Hardiness of the Onion Maggot Delia antiqua through Repression of Depolymerization of Actin at Low Temperatures

    PubMed Central

    Kayukawa, Takumi; Ishikawa, Yukio

    2009-01-01

    Winter-diapause and cold-acclimated non-diapause pupae of the onion maggot, Delia antiqua (Diptera: Anthomyiidae), show strong cold hardiness. To obtain insights into the mechanisms involved in the enhancement of cold hardiness, we investigated the expression patterns of genes encoding subunits of chaperonin (CCT) and the morphology of actin, a substrate of CCT, at low temperatures. Quantitative real-time PCR analyses showed the mRNA levels of CCT subunits in pupal tissues to be highly correlated with the cold hardiness of the pupae. While actin in the Malpighian tubules of non-cold-hardy pupae showed extensive depolymerization after a cold treatment, actin in the same tissue of cold-hardy pupae was not depolymerized. Damage to cell membranes became apparent after the depolymerization of actin. Moreover, administration of Latrunculin B, an inhibitor of actin polymerization, to the larvae markedly decreased the cold hardiness of the pupae obtained. These findings suggest that CCT contributes to the cold hardiness of D. antiqua through the repression of depolymerization of actin at low temperatures. PMID:20011606

  3. Compromises in career-related decisions: examining the role of compromise severity.

    PubMed

    Wee, Serena

    2014-10-01

    This study tested L. S. Gottfredson's (1996) revised compromise theory by examining whether the relative importance of job sex type, job prestige, and person-job interest congruence for predicting job choice changed as the level of compromise required changed. The fully within-persons design had participants engage in a simulated occupational choice task where job sex type and job prestige were manipulated to be experimentally independent. Participants 1st categorized jobs as unacceptable, acceptable, or preferred. Then, within each category, they made further pairwise choices among jobs in that category. In Study 1, participants were 168 college seniors (124 women, 44 men) from a large Midwestern university. In Study 2, participants were 262 (146 women, 116 men) individuals residing in the United States and recruited via Amazon's Mechanical Turk platform. Across both studies, job sex type predicted choice when large compromises were required. Across both studies, job prestige did not predict choice when moderate compromises were required. In Study 2 but not Study 1, person-job interest congruence predicted choice when minimal compromises were required. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  4. The dental management of medically compromised patients.

    PubMed

    Goss, A N

    1984-12-01

    There is an increasing population of apparently well, but in fact medically compromised people in the community. Most will require dental treatment at some stage and will usually seek it away from a hospital environment. In a recent survey of a general dental practice in Australia it was found that up to 55 per cent of some age groups had concurrent medical problems. Thus there is a real risk that adverse interactions between medical conditions and dental treatment may occur--on some occasions, even fatal ones. It is not possible for any one individual to know the details of all medical conditions, their treatment and the possible interactions with dental treatment. However, by the application of some sound general principles the risks of any potential interactions can be evaluated. The essential steps are: knowledge of the medical history of all patients; knowledge of the potential interactions; and knowledge of the management of medical emergencies. These principles will be discussed and illustrated by examples of medically compromised patients who may experience common or potentially serious sequelae as a result of dental treatment.

  5. 40 CFR 13.26 - Payment of compromised claims.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... will be required to execute a confess-judgment agreement which accelerates payment of the balance due... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Payment of compromised claims. 13.26... STANDARDS Compromise of Debts § 13.26 Payment of compromised claims. The Administrator normally will...

  6. 40 CFR 13.26 - Payment of compromised claims.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... will be required to execute a confess-judgment agreement which accelerates payment of the balance due... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Payment of compromised claims. 13.26... STANDARDS Compromise of Debts § 13.26 Payment of compromised claims. The Administrator normally will...

  7. 39 CFR 964.18 - Compromise and informal disposition.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Compromise and informal disposition. 964.18... DISPOSITION OF MAIL WITHHELD FROM DELIVERY PURSUANT TO 39 U.S.C. 3003, 3004 § 964.18 Compromise and informal disposition. Nothing in these rules precludes the compromise, settlement, and informal disposition of...

  8. 39 CFR 964.18 - Compromise and informal disposition.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Compromise and informal disposition. 964.18... DISPOSITION OF MAIL WITHHELD FROM DELIVERY PURSUANT TO 39 U.S.C. 3003, 3004 § 964.18 Compromise and informal disposition. Nothing in these rules precludes the compromise, settlement, and informal disposition of...

  9. 39 CFR 965.13 - Compromise and informal disposition.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Compromise and informal disposition. 965.13... RELATIVE TO MAIL DISPUTES § 965.13 Compromise and informal disposition. Nothing in these rules precludes the compromise, settlement, and informal disposition of proceedings initiated under these rules at any...

  10. 39 CFR 965.13 - Compromise and informal disposition.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Compromise and informal disposition. 965.13... RELATIVE TO MAIL DISPUTES § 965.13 Compromise and informal disposition. Nothing in these rules precludes the compromise, settlement, and informal disposition of proceedings initiated under these rules at any...

  11. 39 CFR 964.18 - Compromise and informal disposition.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Compromise and informal disposition. 964.18... DISPOSITION OF MAIL WITHHELD FROM DELIVERY PURSUANT TO 39 U.S.C. 3003, 3004 § 964.18 Compromise and informal disposition. Nothing in these rules precludes the compromise, settlement, and informal disposition of...

  12. 29 CFR 1450.13 - Exploration of compromise.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Exploration of compromise. 1450.13 Section 1450.13 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE COLLECTIONS OF CLAIMS... § 1450.13 Exploration of compromise. FMCS may attempt to effect compromise, preferably during the course...

  13. 47 CFR 1.1915 - Exploration of compromise.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Exploration of compromise. 1.1915 Section 1.1915 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Collection of... Collection § 1.1915 Exploration of compromise. The Commission may attempt to effect compromise, preferably...

  14. 29 CFR 1450.13 - Exploration of compromise.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Exploration of compromise. 1450.13 Section 1450.13 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE COLLECTIONS OF CLAIMS... § 1450.13 Exploration of compromise. FMCS may attempt to effect compromise, preferably during the course...

  15. 47 CFR 1.1915 - Exploration of compromise.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Exploration of compromise. 1.1915 Section 1.1915 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Collection of... Collection § 1.1915 Exploration of compromise. The Commission may attempt to effect compromise, preferably...

  16. Morgellons: contested illness, diagnostic compromise and medicalisation.

    PubMed

    Fair, Brian

    2010-05-01

    The case of Morgellons illustrates how the emergence of a new medically contested illness intersected with and impacted on the diagnostic processes of an existing uncontested psychiatric condition, Delusional Parasitosis (DP). More specifically, the sociopolitical processes at play in the contested illness, Morgellons, dubiously reflect patient empowerment, as well the resilience and power of medical jurisdiction. This research offers insights into the contested illness and medicalisation literatures, and aims to bridge these two approaches towards the relationship between patient empowerment and medical authority, which I do through the notion of doctor-patient compromise. The data for this research come from a comprehensive qualitative analysis of Morgellons discourse through four key sources: the pro-Morgellons website Morgellons.org; the anti-Morgellons website Morgellonswatch.com; the popular media's portrayal of Morgellons; and the DP and Morgellons articles published in peer-reviewed medical journals, as made available on PubMed.

  17. Creating the Functional Single-Ring GroEL-GroES Chaperonin Systems via Modulating GroEL-GroES Interaction.

    PubMed

    Illingworth, Melissa; Ellis, Holly; Chen, Lingling

    2017-08-29

    Chaperonin and cochaperonin, represented by E. coli GroEL and GroES, are essential molecular chaperones for protein folding. The double-ring assembly of GroEL is required to function with GroES, and a single-ring GroEL variant GroEL(SR) forms a stable complex with GroES, arresting the chaperoning reaction cycle. GroES I25 interacts with GroEL; however, mutations of I25 abolish GroES-GroEL interaction due to the seven-fold mutational amplification in heptameric GroES. To weaken GroEL(SR)-GroES interaction in a controlled manner, we used groES (7), a gene linking seven copies of groES, to incorporate I25 mutations in selected GroES modules in GroES(7). We generated GroES(7) variants with different numbers of GroESI25A or GroESI25D modules and different arrangements of the mutated modules, and biochemically characterized their interactions with GroEL(SR). GroES(7) variants with two mutated modules participated in GroEL(SR)-mediated protein folding in vitro. GroES(7) variants with two or three mutated modules collaborated with GroEL(SR) to perform chaperone function in vivo: three GroES(7) variants functioned with GroEL(SR) under both normal and heat-shock conditions. Our studies on functional single-ring bacterial chaperonin systems are informative to the single-ring human mitochondrial chaperonin mtHsp60-mtHsp10, and will provide insights into how the double-ring bacterial system has evolved to the single-ring mtHsp60-mtHsp10.

  18. Fitness Trade-Offs Determine the Role of the Molecular Chaperonin GroEL in Buffering Mutations

    PubMed Central

    Sabater-Muñoz, Beatriz; Prats-Escriche, Maria; Montagud-Martínez, Roser; López-Cerdán, Adolfo; Toft, Christina; Aguilar-Rodríguez, José; Wagner, Andreas; Fares, Mario A.

    2015-01-01

    Molecular chaperones fold many proteins and their mutated versions in a cell and can sometimes buffer the phenotypic effect of mutations that affect protein folding. Unanswered questions about this buffering include the nature of its mechanism, its influence on the genetic variation of a population, the fitness trade-offs constraining this mechanism, and its role in expediting evolution. Answering these questions is fundamental to understand the contribution of buffering to increase genetic variation and ecological diversification. Here, we performed experimental evolution, genome resequencing, and computational analyses to determine the trade-offs and evolutionary trajectories of Escherichia coli expressing high levels of the essential chaperonin GroEL. GroEL is abundantly present in bacteria, particularly in bacteria with large loads of deleterious mutations, suggesting its role in mutational buffering. We show that groEL overexpression is costly to large populations evolving in the laboratory, leading to groE expression decline within 66 generations. In contrast, populations evolving under the strong genetic drift characteristic of endosymbiotic bacteria avoid extinction or can be rescued in the presence of abundant GroEL. Genomes resequenced from cells evolved under strong genetic drift exhibited significantly higher tolerance to deleterious mutations at high GroEL levels than at native levels, revealing that GroEL is buffering mutations in these cells. GroEL buffered mutations in a highly diverse set of proteins that interact with the environment, including substrate and ion membrane transporters, hinting at its role in ecological diversification. Our results reveal the fitness trade-offs of mutational buffering and how genetic variation is maintained in populations. PMID:26116858

  19. Molecular diagnostic tools for detection and differentiation of phytoplasmas based on chaperonin-60 reveal differences in host plant infection patterns.

    PubMed

    Dumonceaux, Tim J; Green, Margaret; Hammond, Christine; Perez, Edel; Olivier, Chrystel

    2014-01-01

    Phytoplasmas ('Candidatus Phytoplasma' spp.) are insect-vectored bacteria that infect a wide variety of plants, including many agriculturally important species. The infections can cause devastating yield losses by inducing morphological changes that dramatically alter inflorescence development. Detection of phytoplasma infection typically utilizes sequences located within the 16S-23S rRNA-encoding locus, and these sequences are necessary for strain identification by currently accepted standards for phytoplasma classification. However, these methods can generate PCR products >1400 bp that are less divergent in sequence than protein-encoding genes, limiting strain resolution in certain cases. We describe a method for accessing the chaperonin-60 (cpn60) gene sequence from a diverse array of 'Ca.Phytoplasma' spp. Two degenerate primer sets were designed based on the known sequence diversity of cpn60 from 'Ca.Phytoplasma' spp. and used to amplify cpn60 gene fragments from various reference samples and infected plant tissues. Forty three cpn60 sequences were thereby determined. The cpn60 PCR-gel electrophoresis method was highly sensitive compared to 16S-23S-targeted PCR-gel electrophoresis. The topology of a phylogenetic tree generated using cpn60 sequences was congruent with that reported for 16S rRNA-encoding genes. The cpn60 sequences were used to design a hybridization array using oligonucleotide-coupled fluorescent microspheres, providing rapid diagnosis and typing of phytoplasma infections. The oligonucleotide-coupled fluorescent microsphere assay revealed samples that were infected simultaneously with two subtypes of phytoplasma. These tools were applied to show that two host plants, Brassica napus and Camelina sativa, displayed different phytoplasma infection patterns.

  20. Fitness Trade-Offs Determine the Role of the Molecular Chaperonin GroEL in Buffering Mutations.

    PubMed

    Sabater-Muñoz, Beatriz; Prats-Escriche, Maria; Montagud-Martínez, Roser; López-Cerdán, Adolfo; Toft, Christina; Aguilar-Rodríguez, José; Wagner, Andreas; Fares, Mario A

    2015-10-01

    Molecular chaperones fold many proteins and their mutated versions in a cell and can sometimes buffer the phenotypic effect of mutations that affect protein folding. Unanswered questions about this buffering include the nature of its mechanism, its influence on the genetic variation of a population, the fitness trade-offs constraining this mechanism, and its role in expediting evolution. Answering these questions is fundamental to understand the contribution of buffering to increase genetic variation and ecological diversification. Here, we performed experimental evolution, genome resequencing, and computational analyses to determine the trade-offs and evolutionary trajectories of Escherichia coli expressing high levels of the essential chaperonin GroEL. GroEL is abundantly present in bacteria, particularly in bacteria with large loads of deleterious mutations, suggesting its role in mutational buffering. We show that groEL overexpression is costly to large populations evolving in the laboratory, leading to groE expression decline within 66 generations. In contrast, populations evolving under the strong genetic drift characteristic of endosymbiotic bacteria avoid extinction or can be rescued in the presence of abundant GroEL. Genomes resequenced from cells evolved under strong genetic drift exhibited significantly higher tolerance to deleterious mutations at high GroEL levels than at native levels, revealing that GroEL is buffering mutations in these cells. GroEL buffered mutations in a highly diverse set of proteins that interact with the environment, including substrate and ion membrane transporters, hinting at its role in ecological diversification. Our results reveal the fitness trade-offs of mutational buffering and how genetic variation is maintained in populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Coevolution analyses illuminate the dependencies between amino acid sites in the chaperonin system GroES-L

    PubMed Central

    2013-01-01

    Background GroESL is a heat-shock protein ubiquitous in bacteria and eukaryotic organelles. This evolutionarily conserved protein is involved in the folding of a wide variety of other proteins in the cytosol, being essential to the cell. The folding activity proceeds through strong conformational changes mediated by the co-chaperonin GroES and ATP. Functions alternative to folding have been previously described for GroEL in different bacterial groups, supporting enormous functional and structural plasticity for this molecule and the existence of a hidden combinatorial code in the protein sequence enabling such functions. Describing this plasticity can shed light on the functional diversity of GroEL. We hypothesize that different overlapping sets of amino acids coevolve within GroEL, GroES and between both these proteins. Shifts in these coevolutionary relationships may inevitably lead to evolution of alternative functions. Results We conducted the first coevolution analyses in an extensive bacterial phylogeny, revealing complex networks of evolutionary dependencies between residues in GroESL. These networks differed among bacterial groups and involved amino acid sites with functional importance and others with previously unsuspected functional potential. Coevolutionary networks formed statistically independent units among bacterial groups and map to structurally continuous regions in the protein, suggesting their functional link. Sites involved in coevolution fell within narrow structural regions, supporting dynamic combinatorial functional links involving similar protein domains. Moreover, coevolving sites within a bacterial group mapped to regions previously identified as involved in folding-unrelated functions, and thus, coevolution may mediate alternative functions. Conclusions Our results highlight the evolutionary plasticity of GroEL across the entire bacterial phylogeny. Evidence on the functional importance of coevolving sites illuminates the as yet

  2. Identification of Staphylococcus species and subspecies by the chaperonin 60 gene identification method and reverse checkerboard hybridization.

    PubMed Central

    Goh, S H; Santucci, Z; Kloos, W E; Faltyn, M; George, C G; Driedger, D; Hemmingsen, S M

    1997-01-01

    A previous study (S. H. Goh et al., J. Clin. Microbiol. 34:818-823, 1996) demonstrated that a 600-bp region of the chaperonin 60 (Cpn60) genes from various bacterial isolates could be amplified by PCR with a pair of degenerate primers and that the products could be used as species-specific probes for Staphylococcus aureus, S. epidermidis, S. haemolyticus, S. lugdunensis, S. saprophyticus, and S. schleiferi. To further validate the utility of bacterial Cpn60 genes as universal targets for bacterial identification (ID), reverse checkerboard chemiluminescent hybridization experiments were performed with DNA probes from 34 different Staphylococcus species and subspecies. With the exception of probes from the Cpn60 genes of S. intermedius and S. delphini, which cross hybridized, all were species specific. Two subspecies of both S. capitis and S. cohnii were differentiated from one another, while DNAs from the two S. schleiferi subspecies cross hybridized. When 40 known Staphylococcus isolates were tested in a blind experiment by the Cpn60 gene method, 36 strains, representing six species and one subspecies (S. sciuri, S. caseolyticus, S. hominis, S. warneri, S. hyicus, S. haemolyticus, and S. capitis subsp. ureolyticus), were correctly identified. DNA from the four remaining isolates, known to be S. hyicus bovine strains, failed to hybridize to DNA from the S. hyicus target strain or any other Staphylococcus species. However, DNAs from these S. hyicus isolates did cross hybridize with each other. New DNA sequence data and evidence from previous studies suggest some genetic divergence between the two groups of S. hyicus isolates. Our results demonstrate that this Cpn60 gene-based ID method has the potential to be a basic method for bacterial ID. Studies are in progress to further validate the utility of this Cpn60 gene system for ID of Staphylococcus and other genera, including those of slow-growing microorganisms. PMID:9399505

  3. Chaperonin GroEL accelerates protofibril formation and decorates fibrils of the Het-s prion protein.

    PubMed

    Wälti, Marielle A; Schmidt, Thomas; Murray, Dylan T; Wang, Huaibin; Hinshaw, Jenny E; Clore, G Marius

    2017-08-22

    We have studied the interaction of the prototypical chaperonin GroEL with the prion domain of the Het-s protein using solution and solid-state NMR, electron and atomic force microscopies, and EPR. While GroEL accelerates Het-s protofibril formation by several orders of magnitude, the rate of appearance of fibrils is reduced. GroEL remains bound to Het-s throughout the aggregation process and densely decorates the fibrils at a regular spacing of ∼200 Å. GroEL binds to the Het-s fibrils via its apical domain located at the top of the large open ring. Thus, apo GroEL and bullet-shaped GroEL/GroES complexes in which only a single ring is capped by GroES interact with the Het-s fibrils; no evidence is seen for any interaction with football-shaped GroEL/GroES complexes in which both rings are capped by GroES. EPR spectroscopy shows that rotational motion of a nitroxide spin label, placed at the N-terminal end of the first β-strand of Het-s fibrils, is significantly reduced in both Het-s/GroEL aggregates and Het-s fibrils, but virtually completely eliminated in Het-s/GroEL fibrils, suggesting that in the latter, GroEL may come into close proximity to the nitroxide label. Solid-state NMR measurements indicate that GroEL binds to the mobile regions of the Het-s fibril comprising the N-terminal tail and a loop connecting β-strands 4 and 5, consistent with interactions involving GroEL binding consensus sequences located therein.

  4. Pyrosequencing of the Chaperonin-60 Universal Target as a Tool for Determining Microbial Community Composition ▿ †

    PubMed Central

    Schellenberg, John; Links, Matthew G.; Hill, Janet E.; Dumonceaux, Tim J.; Peters, Geoffrey A.; Tyler, Shaun; Ball, T. Blake; Severini, Alberto; Plummer, Francis A.

    2009-01-01

    We compared dideoxy sequencing of cloned chaperonin-60 universal target (cpn60 UT) amplicons to pyrosequencing of amplicons derived from vaginal microbial communities. In samples pooled from a number of individuals, the pyrosequencing method produced a data set that included virtually all of the sequences that were found within the clone library and revealed an additional level of taxonomic richness. However, the relative abundances of the sequences were different in the two datasets. These observations were expanded and confirmed by the analysis of paired clone library and pyrosequencing datasets from vaginal swabs taken from four individuals. Both for individuals with a normal vaginal microbiota and for those with bacterial vaginosis, the pyrosequencing method revealed a large number of low-abundance taxa that were missed by the clone library approach. In addition, we showed that the pyrosequencing method generates a reproducible profile of microbial community structure in replicate amplifications from the same community. We also compared the taxonomic composition of a vaginal microbial community determined by pyrosequencing of 16S rRNA amplicons to that obtained using cpn60 universal primers. We found that the profiles generated by the two molecular targets were highly similar, with slight differences in the proportional representation of the taxa detected. However, the number of operational taxonomic units was significantly higher in the cpn60 data set, suggesting that the protein-encoding gene provides improved species resolution over the 16S rRNA target. These observations demonstrate that pyrosequencing of cpn60 UT amplicons provides a robust, reliable method for deep sequencing of microbial communities. PMID:19270139

  5. Assisted protein folding at low temperature: evolutionary adaptation of the Antarctic fish chaperonin CCT and its client proteins

    PubMed Central

    Cuellar, Jorge; Yébenes, Hugo; Parker, Sandra K.; Carranza, Gerardo; Serna, Marina; Valpuesta, José María; Zabala, Juan Carlos; Detrich, H. William

    2014-01-01

    ABSTRACT Eukaryotic ectotherms of the Southern Ocean face energetic challenges to protein folding assisted by the cytosolic chaperonin CCT. We hypothesize that CCT and its client proteins (CPs) have co-evolved molecular adaptations that facilitate CCT–CP interaction and the ATP-driven folding cycle at low temperature. To test this hypothesis, we compared the functional and structural properties of CCT–CP systems from testis tissues of an Antarctic fish, Gobionotothen gibberifrons (Lönnberg) (habitat/body T = −1.9 to +2°C), and of the cow (body T = 37°C). We examined the temperature dependence of the binding of denatured CPs (β-actin, β-tubulin) by fish and bovine CCTs, both in homologous and heterologous combinations and at temperatures between −4°C and 20°C, in a buffer conducive to binding of the denatured CP to the open conformation of CCT. In homologous combination, the percentage of G. gibberifrons CCT bound to CP declined linearly with increasing temperature, whereas the converse was true for bovine CCT. Binding of CCT to heterologous CPs was low, irrespective of temperature. When reactions were supplemented with ATP, G. gibberifrons CCT catalyzed the folding and release of actin at 2°C. The ATPase activity of apo-CCT from G. gibberifrons at 4°C was ∼2.5-fold greater than that of apo-bovine CCT, whereas equivalent activities were observed at 20°C. Based on these results, we conclude that the catalytic folding cycle of CCT from Antarctic fishes is partially compensated at their habitat temperature, probably by means of enhanced CP-binding affinity and increased flexibility of the CCT subunits. PMID:24659247

  6. Chaperonin GroEL a Brucella immunodominant antigen identified using Nanobody and MALDI-TOF-MS technologies.

    PubMed

    Abbady, A Q; Al-Daoude, A; Al-Mariri, A; Zarkawi, M; Muyldermans, S

    2012-05-15

    The deployment of today's antibodies that are able to distinguish Brucella from the closely similar pathogens, such as Yersinia, is still considered a great challenge since both pathogens share identical LPS (lipopolysaccharide) O-ring epitopes. In addition, because of the great impact of Brucella on health and economy in many countries including Syria, much effort is going to the development of next generation vaccines, mainly on the identification of new immunogenic proteins of this pathogen. In this context, Brucella-specific nanobodies (Nbs), camel genetic engineered heavy-chain antibody fragments, could be of great value. Previously, a large Nb library was constructed from a camel immunized with heat-killed Brucella. Phage display panning of this 'immune' library with Brucella total lysate resulted in a remarkable fast enrichment for a Nb referred to as NbBruc02. In the present work, we investigated the main characteristics of this Nb that can efficiently distinguish under well-defined conditions the Brucella from other bacteria including Yersinia. NbBruc02 showed a strong and specific interaction with its antigen within the crude lysate as tested by a surface plasmon resonance (SPR) biosensor and it was also able to pull down its cognate antigen from such lysate by immuno-capturing. Using matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), NbBruc02 specific antigen was identified as chaperonin GroEL, also known as heat shock protein of 60 kDa (HSP-60), which represents a Brucella immunodominant antigen responsible of maintaining proteins folding during stress conditions. Interestingly, the antigen recognition by NbBruc02 was found to be affected by the state of GroEL folding. Thus, the Nb technology applied in the field of infectious diseases, e.g. brucellosis, yields two outcomes: (1) it generates specific binders that can be used for diagnosis, and perhaps treatment, and (2) it identifies the immunogenic candidate

  7. Specific cross-reactivity of antibodies raised against two major stress proteins, stress 70 and chaperonin 60, in diverse species

    SciTech Connect

    Sanders, B.M.; Martin, L.S.; Nakagawa, P.A. ); Hunter, D.A. . Biologisk Inst.); Miller, S. ); Ullrich, S.J. . National Cancer Inst.)

    1994-08-01

    Immunoblot analysis using several antibodies raised against two major families of stress proteins, stress 70 and chaperonin 60 (cpn60), which are highly conserved in mammals, was carried out in diverse species often used in environmental research, including molluscs, annelids, crustaceans, echinoderms, and fish. The study revealed surprisingly different patterns of antibody cross-reactivity among species. The monoclonal anti-stress 70 antibody (mAb) C92 was the least cross-reactive for all species tested. The mAbs anti-stress 70 N27, BRM-22, and 3a3 were more broadly cross-reactive, but their binding specifities to stress 70 isoforms in the diverse species tested did not correlate with one another or follow taxonomic lines. The polyclonal anti-stress 70 antibody reacted to proteins in the 70 to 74 kDa range in all fish examined and in most invertebrates. When a polyclonal antibody (pAb) raised against cpn60 from a moth was used as a probe, specific binding was observed with proteins in the 60 to 64 kDa range in all fish examined and in most invertebrates. However, the size and number of isoforms that reacted with the pAb were species specific. These data suggest that these two major stress protein families are less highly conserved in invertebrates and fish than in mammals. Therefore, to minimize misinterpretation when using antibodies in heterologous assays with species in which the stress response has not been well characterized, it is important to determine which isoforms of stress 70 react with a particular antibody and to take into account the differential regulation of each member of this multigene family.

  8. Mechanical compromise of partially lacerated flexor tendons.

    PubMed

    Kondratko, Jaclyn; Duenwald-Kuehl, Sarah; Lakes, Roderic; Vanderby, Ray

    2013-01-01

    Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the "50% rule." Few studies provide mechanical insight into the 50% rule. In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75 mm deep transverse, midsubstance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the 50% rule. Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.

  9. Compromised natural killer cells in pulmonary embolism

    PubMed Central

    Zhang, Xiaoyu; Wang, Qiang; Shen, Yuqin; Song, Haoming; Gong, Zhu; Wang, Lemin

    2015-01-01

    Objective: The high morbidity, mortality and misdiagnosis rate render pulmonary embolism (PE) as a worldwide health problem. However, the etiology and pathogenesis of this disease have not been well characterized. Increasing studies indicate infection and immunity play a crucial role in PE. Natural killer (NK) cells act as a bridge between the innate immune and acquired immune. This study aimed to investigate the possible function of NK cells in PE. Methods: Human cDNA microarray analysis was employed to detect genes associated with NK cells in peripheral blood mononuclear cells (PBMCs). Random variance model corrected t-test was used for statistical analysis of differential gene expression. Flow cytometry was performed to detect the CD16+CD56+ NK cells. Results: In the present study, based on gene expression microarray analysis, we showed four inhibitory receptors (KLRB1, KLRD1, KLRF1, KLRG1) and four activating receptors (KLRC1, KLRC3, KLRK1 and NCR1) on NK cells were remarkably down-regulated and the cytological experiment demonstrated the proportion of CD16+CD56+ NK cells among PBMCs decreased in the PE group. Conclusions: We confirmed the presence of reduced expression of critical activating as well as inhibitory NK cell receptors and low proportion of CD16+CD56+ NK cells in PE. The consistence between genomic and cytological examination suggests compromised NK cells may contribute to the pathogenesis of PE. PMID:26339393

  10. Morphine induces albuminuria by compromising podocyte integrity.

    PubMed

    Lan, Xiqian; Rai, Partab; Chandel, Nirupama; Cheng, Kang; Lederman, Rivka; Saleem, Moin A; Mathieson, Peter W; Husain, Mohammad; Crosson, John T; Gupta, Kalpna; Malhotra, Ashwani; Singhal, Pravin C

    2013-01-01

    Morphine has been reported to accelerate the progression of chronic kidney disease. However, whether morphine affects slit diaphragm (SD), the major constituent of glomerular filtration barrier, is still unclear. In the present study, we examined the effect of morphine on glomerular filtration barrier in general and podocyte integrity in particular. Mice were administered either normal saline or morphine for 72 h, then urine samples were collected and kidneys were subsequently isolated for immunohistochemical studies and Western blot. For in vitro studies, human podocytes were treated with morphine and then probed for the molecular markers of slit diaphragm. Morphine-receiving mice displayed a significant increase in albuminuria and showed effacement of podocyte foot processes. In both in vivo and in vitro studies, the expression of synaptopodin, a molecular marker for podocyte integrity, and the slit diaphragm constituting molecules (SDCM), such as nephrin, podocin, and CD2-associated protein (CD2AP), were decreased in morphine-treated podocytes. In vitro studies indicated that morphine modulated podocyte expression of SDCM through opiate mu (MOR) and kappa (KOR) receptors. Since morphine also enhanced podocyte oxidative stress, the latter seems to contribute to decreased SDCM expression. In addition, AKT, p38, and JNK pathways were involved in morphine-induced down regulation of SDCM in human podocytes. These findings demonstrate that morphine has the potential to alter the glomerular filtration barrier by compromising the integrity of podocytes.

  11. Female genital alteration: a compromise solution.

    PubMed

    Arora, Kavita Shah; Jacobs, Allan J

    2016-03-01

    Despite 30 years of advocacy, the prevalence of non-therapeutic female genital alteration (FGA) in minors is stable in many countries. Educational efforts have minimally changed the prevalence of this procedure in regions where it has been widely practiced. In order to better protect female children from the serious and long-term harms of some types of non-therapeutic FGA, we must adopt a more nuanced position that acknowledges a wide spectrum of procedures that alter female genitalia. We offer a revised categorisation for non-therapeutic FGA that groups procedures by effect and not by process. Acceptance of de minimis procedures that generally do not carry long-term medical risks is culturally sensitive, does not discriminate on the basis of gender, and does not violate human rights. More morbid procedures should not be performed. However, accepting de minimis non-therapeutic f FGA procedures enhances the effort of compassionate practitioners searching for a compromise position that respects cultural differences but protects the health of their patients.

  12. Immunodiagnosis of histoplasmosis in a compromised host.

    PubMed Central

    Land, G A; Foxworth, J H; Smith, K E

    1978-01-01

    Three serological tests for the diagnosis of histoplasmosis were compared for sensitivity and specificity in serum from blood bank donors, patients with histoplasmosis, and infected or noninfected immunosuppressed patients. The histoplasmin latex agglutination test was positive in 9% of the normal patients, 33% of the histoplasmosis patients, and 61% of the noninfected immunosuppressed patients. Since the test is prone to many false-positive results in patients with inflammatory diseases or non-Histoplasma infections, it has limited potential as a screening test among compromised patients. Immunodiffusion and counterimmunoelectrophoresis using a mycelial antigen were found to be more sensitive than either test using a combined yeast and mycelial antigen or a pure yeast phase antigen. Counterimmunoelectrophoresis at pH 7.2 proved to be the test of choice for serodiagnosis of histoplasmosis, resolving 85% of the immunocompetent infected patients and 100% of the infected immunosuppressed patients. Results indicated that counterimmunoelectrophoresis in conjunction with immunodiffusion could be used as a screening protocol to determine infection in incoming patients in a cancer hospital. PMID:103889

  13. Silencing of chaperonin 21, that was differentially expressed in inflorescence of seedless and seeded grapes, promoted seed abortion in tobacco and tomato fruits.

    PubMed

    Hanania, Uri; Velcheva, Margarita; Or, Etti; Flaishman, Moshe; Sahar, Nachman; Perl, Avihai

    2007-08-01

    Vitis vinifera L. cv. 'Thompson Seedless' presents a type of stenospermocarpy in grape where fertilization occurs but seeds abort and fail to develop. To unravel the molecular basis for stenospermocarpy in grapes, subtractive hybridization was carried out in order to isolate differentially regulated genes that participate in the seedlessness machinery. Two 'Thompson' lines, a seeded and a seedless, were screened during different flower developmental stages. One of the genes, that was differentially expressed between the seeded and seedless lines, was the chloroplast chaperonin 21 (ch-Cpn21). ch-Cpn21 is a 21-kDa co-chaperonin polypeptide formed by two GroES-like domains fused together in tandem. Silencing of ch-Cpn21 in Nicotiana benthamiana plants resulted in leaf stunting, chlorosis, as well as ovary necrogenesis leading to seed abortion. Moreover, organ-specific silencing of ch-Cpn21 only in Lycopersicum esculentum fruits resulted in the development of seedless tomatoes. These results suggest that ch-Cpn21 may play a role in seed abortion in stenospermocarpic grapes.

  14. Identification of a novel BBS gene (BBS12) highlights the major role of a vertebrate-specific branch of chaperonin-related proteins in Bardet-Biedl syndrome.

    PubMed

    Stoetzel, Corinne; Muller, Jean; Laurier, Virginie; Davis, Erica E; Zaghloul, Norann A; Vicaire, Serge; Jacquelin, Cecile; Plewniak, Frederic; Leitch, Carmen C; Sarda, Pierre; Hamel, Christian; de Ravel, Thomy J L; Lewis, Richard Alan; Friederich, Evelyne; Thibault, Christelle; Danse, Jean-Marc; Verloes, Alain; Bonneau, Dominique; Katsanis, Nicholas; Poch, Olivier; Mandel, Jean-Louis; Dollfus, Helene

    2007-01-01

    Bardet-Biedl syndrome (BBS) is primarily an autosomal recessive ciliopathy characterized by progressive retinal degeneration, obesity, cognitive impairment, polydactyly, and kidney anomalies. The disorder is genetically heterogeneous, with 11 BBS genes identified to date, which account for ~70% of affected families. We have combined single-nucleotide-polymorphism array homozygosity mapping with in silico analysis to identify a new BBS gene, BBS12. Patients from two Gypsy families were homozygous and haploidentical in a 6-Mb region of chromosome 4q27. FLJ35630 was selected as a candidate gene, because it was predicted to encode a protein with similarity to members of the type II chaperonin superfamily, which includes BBS6 and BBS10. We found pathogenic mutations in both Gypsy families, as well as in 14 other families of various ethnic backgrounds, indicating that BBS12 accounts for approximately 5% of all BBS cases. BBS12 is vertebrate specific and, together with BBS6 and BBS10, defines a novel branch of the type II chaperonin superfamily. These three genes are characterized by unusually rapid evolution and are likely to perform ciliary functions specific to vertebrates that are important in the pathophysiology of the syndrome, and together they account for about one-third of the total BBS mutational load. Consistent with this notion, suppression of each family member in zebrafish yielded gastrulation-movement defects characteristic of other BBS morphants, whereas simultaneous suppression of all three members resulted in severely affected embryos, possibly hinting at partial functional redundancy within this protein family.

  15. Identification of in vivo substrates of the yeast mitochondrial chaperonins reveals overlapping but non-identical requirement for hsp60 and hsp10.

    PubMed Central

    Dubaquié, Y; Looser, R; Fünfschilling, U; Jenö, P; Rospert, S

    1998-01-01

    The mechanism of chaperonin-assisted protein folding has been mostly analyzed in vitro using non-homologous substrate proteins. In order to understand the relative importance of hsp60 and hsp10 in the living cell, homologous substrate proteins need to be identified and analyzed. We have devised a novel screen to test the folding of a large variety of homologous substrates in the mitochondrial matrix in the absence or presence of functional hsp60 or hsp10. The identified substrates have an Mr of 15-90 kDa and fall into three groups: (i) proteins that require both hsp60 and hsp10 for correct folding; (ii) proteins that completely fail to fold after inactivation of hsp60 but are unaffected by the inactivation of hsp10; and (iii) newly imported hsp60 itself, which is more severely affected by inactivation of hsp10 than by inactivation of pre-existing hsp60. The majority of the identified substrates are group I proteins. For these, the lack of hsp60 function has a more pronounced effect than inactivation of hsp10. We suggest that homologous substrate proteins have differential chaperonin requirements, indicating that hsp60 and hsp10 do not always act as a single functional unit in vivo. PMID:9774331

  16. Isolation of a gene encoding a chaperonin-like protein by complementation of yeast amino acid transport mutants with human cDNA.

    PubMed Central

    Segel, G B; Boal, T R; Cardillo, T S; Murant, F G; Lichtman, M A; Sherman, F

    1992-01-01

    A human cDNA library in lambda-yes plasmid was used to transform a strain of Saccharomyces cerevisiae with defects in histidine biosynthesis (his4-401) and histidine permease (hip1-614) and with the general amino acid permease (GAP) repressed by excess ammonium. We investigated three plasmids complementing the transport defect on a medium with a low concentration of histidine. Inserts in these plasmids hybridized with human genomic but not yeast genomic DNA, indicating their human origin. mRNA corresponding to the human DNA insert was produced by each yeast transformant. Complementation of the histidine transport defect was confirmed by direct measurement of histidine uptake, which was increased 15- to 65-fold in the transformants as compared with the parental strain. Competitive inhibition studies, measurement of citrulline uptake, and lack of complementation in gap1- strains indicated that the human cDNA genes code for proteins that prevent GAP repression by ammonium. The amino acid sequence encoded by one of the cDNA clones is related to T-complex proteins, which suggests a "chaperonin"-like function. We suggest that the human chaperonin-like protein stabilizes the NPR1 gene product and prevents inactivation of GAP. Images PMID:1352881

  17. A yeast two-hybrid screen reveals a strong interaction between the Legionella chaperonin Hsp60 and the host cell small heat shock protein Hsp10.

    PubMed

    Nasrallah, Gheyath K

    2015-06-01

    L. pneumophila is an intracellular bacterium that replicates inside a membrane-bound vacuole called Legionella-containing vacuole (LCV), where it plentifully liberates its HtpB chaperonin. From LCV, HtpB reaches the host cell cytoplasm, where it interacts with SAMDC, a cytoplasmic protein required for synthesis of host polyamines that are important for intracellular growth of L. pneumophila. Additionally, cytoplasmic expression of HtpB in S. cerevisiae induces pseudohyphal growth, and in mammalian cells recruits mitochondria to LCV, and modifies actin microfilaments organization. This led us to hypothesize here that HtpB recruits a protein(s) from eukaryotic cells that is involved in the emergence of the aforementioned phenotypes. To identify this protein, a commercially available HeLa cDNA library was screened using a yeast two-hybrid system. Approximately 5×10(6) yeast clones carrying HeLa cDNA library plasmid were screened. Twenty-one positive clones were identified. DNA sequence analysis revealed that all of these positive clones encoded the mammalian small heat shock protein Hsp10. Based on the fact that chaperonions are required to interact with co-chaperonins to function properly in protein folding, we believe that HtpB recruits the host cell Hsp10 to appropriately interact with SAMDC and to induce the multifunction phenotypes deemed important in L. pneumophila pathogenesis.

  18. OsCpn60α1, Encoding the Plastid Chaperonin 60α Subunit, Is Essential for Folding of rbcL

    PubMed Central

    Kim, Sung-Ryul; Yang, Jung-Il; An, Gynheung

    2013-01-01

    Chaperonins are involved in protein-folding. The rice genome encodes six plastid chaperonin subunits (Cpn60) - three α and three β. Our study showed that they were differentially expressed during normal plant development. Moreover, five were induced by heat stress (42°C) but not by cold (10°C). The oscpn60α1 mutant had a pale-green phenotype at the seedling stage and development ceased after the fourth leaf appeared. Transiently expressed OsCpn60α1:GFP fusion protein was localized to the chloroplast stroma. Immuno-blot analysis indicated that the level of Rubisco large subunit (rbcL) was severely reduced in the mutant while levels were unchanged for some imported proteins, e.g., stromal heat shock protein 70 (Hsp70) and chlorophyll a/b binding protein 1 (Lhcb1). This demonstrated that OsCpn60α1 is required for the folding of rbcL and that failure of that process is seedling-lethal. PMID:23620301

  19. Mycobacterium tuberculosis chaperonin 60.1 inhibits leukocyte diapedesis in a murine model of allergic lung inflammation.

    PubMed

    Riffo-Vasquez, Yanira; Coates, Anthony R M; Page, Clive P; Spina, Domenico

    2012-08-01

    Chaperonin 60.1 from Mycobacterium tuberculosis suppressed allergic lung inflammation and bronchial hyperresponsiveness in mice by a mechanism that is yet to be clarified. To investigate the possible antiinflammatory mechanism(s) of action of Cpn60.1 in a model of allergic lung inflammation, ovalbumin (OVA)-allergic mice were pretreated with Cpn60.1 intranasally 20 minutes before each OVA aerosol challenge in a total of three treatments. Readouts were performed 24 hours after last challenge. Pretreatment with Cpn60.1 (1.0-0.001 μg) significantly inhibited the number of eosinophils in bronchoalveolar lavage fluid (OVA, 49.2 ± 12.3 versus Cpn60.1 [1 μg dose], 90.4 ± 2.3 × 10(4) cells/ml) and IL-5 release (OVA, 43 ± 8.5 versus Cpn60.1 [1 μg dose], 3 ± 11 pg/ml) but increased IL-12 levels (OVA, 50 ± 24 versus Cpn60.1 [1 μg dose], 103 ± 13 pg/ml). The effect of Cpn60.1 on cell recruitment and IL-5, but not IL-12, release was abolished in TLR-4 knockout mice. Intravital microscopy demonstrated that Cpn60.1 reduced chemokine-mediated leukocyte rolling and transmigration across the vessel wall (rolling cells: eotaxin, 11.7 ± 1.1 versus Cpn60.1 [1 μg dose], 2.8 ± 1 cells in 30 s). Similarly, Cpn60.1 reduced eotaxin-induced leukocyte migration in vitro (eotaxin, 17.3 ± 3.3 versus Cpn60.1 [0.1 μg dose], 3.3 ± 0.4 cells × 10(4)/ml). Immunostaining demonstrated that Cpn60.1 inhibits VCAM-1 and increases vascular endothelial-cadherin expression in lung vascular tissue, suggesting that the antiinflammatory effect of Cpn60.1 is partly mediated by altering the expression of adhesion molecules. This study shows that Cpn60.1 inhibits leukocyte diapedesis by a TLR-4 and an adhesion molecule-dependent mechanism in allergic inflammation in mice.

  20. Implant surgery in healthy compromised patients-review of literature

    PubMed Central

    Gheorghiu, IM; Stoian, IM

    2014-01-01

    Systemic diseases are of major importance in terms of prosthetic restorations supported by dental implants in healthy compromised patients. Each treatment stage from conception of the treatment plan to the long-term monitoring is under the necessity of the interdisciplinary approach to the underlying disease. Abbreviations: healthy compromised patients = HCP PMID:25870664

  1. 45 CFR 1177.12 - Compromise, suspension and termination.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES CLAIMS COLLECTION § 1177.12 Compromise, suspension and termination. (a) The Chairperson of the National Endowment for the Humanities or... available to the public. (b) The Chairperson of the National Endowment for the Humanities may compromise...

  2. 45 CFR 1177.12 - Compromise, suspension and termination.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES CLAIMS COLLECTION § 1177.12 Compromise, suspension and termination. (a) The Chairperson of the National Endowment for the Humanities or... available to the public. (b) The Chairperson of the National Endowment for the Humanities may compromise...

  3. 45 CFR 1177.12 - Compromise, suspension and termination.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES CLAIMS COLLECTION § 1177.12 Compromise, suspension and termination. (a) The Chairperson of the National Endowment for the Humanities or... available to the public. (b) The Chairperson of the National Endowment for the Humanities may compromise...

  4. 45 CFR 1177.12 - Compromise, suspension and termination.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES CLAIMS COLLECTION § 1177.12 Compromise, suspension and termination. (a) The Chairperson of the National Endowment for the Humanities or... available to the public. (b) The Chairperson of the National Endowment for the Humanities may compromise...

  5. 45 CFR 1177.12 - Compromise, suspension and termination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... THE ARTS AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES CLAIMS COLLECTION § 1177.12 Compromise, suspension and termination. (a) The Chairperson of the National Endowment for the Humanities or... available to the public. (b) The Chairperson of the National Endowment for the Humanities may compromise...

  6. 41 CFR 105-55.020 - Bases for compromise.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... risks involved, GSA will consider the probable amount of court costs and attorney fees pursuant to the... for repayment in the manner set forth in § 105-55.015. (g) To assess the merits of a compromise offer... financial information to assess compromise offers. GSA may use their own financial information form or...

  7. 19 CFR 161.5 - Compromise of Government claims.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Compromise of Government claims. 161.5 Section 161... Government claims. (a) Offer. An offer made pursuant to section 617, Tariff Act of 1930, as amended (19 U.S.C. 1617), in compromise of a Government claim arising under the Customs laws and the terms upon which...

  8. 32 CFR 757.19 - Waiver and compromise.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REGULATIONS Medical Care Recovery Act (MCRA) Claims and Claims Asserted Pursuant to 10 U.S.C. 1095 § 757.19 Waiver and compromise. (a) General. OJAG Code 15 (Claims and Tort Litigation) may authorize waiver or... with Code 15 approval. (b) Waiver and compromise. The JAG designee may waive the Federal...

  9. 31 CFR 16.46 - Compromise or settlement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Compromise or settlement. 16.46 Section 16.46 Money and Finance: Treasury Office of the Secretary of the Treasury REGULATIONS IMPLEMENTING THE PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 16.46 Compromise or settlement. (a) Parties may make...

  10. 39 CFR 953.6 - Compromise and informal dispositions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Compromise and informal dispositions. 953.6... RELATIVE TO MAILABILITY § 953.6 Compromise and informal dispositions. Either party may request the other to consider informal disposition of any question of mailability, and the scheduled hearing date may be...

  11. 39 CFR 953.6 - Compromise and informal dispositions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Compromise and informal dispositions. 953.6... RELATIVE TO MAILABILITY § 953.6 Compromise and informal dispositions. Either party may request the other to consider informal disposition of any question of mailability, and the scheduled hearing date may be...

  12. 39 CFR 953.6 - Compromise and informal dispositions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Compromise and informal dispositions. 953.6... RELATIVE TO MAILABILITY § 953.6 Compromise and informal dispositions. Either party may request the other to consider informal disposition of any question of mailability, and the scheduled hearing date may be...

  13. 5 CFR 1312.30 - Loss or possible compromise.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Loss or possible compromise. 1312.30 Section 1312.30 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION... Classified Information § 1312.30 Loss or possible compromise. Any person who has knowledge of the loss or...

  14. 22 CFR 512.13 - Exploration of compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Exploration of compromise. 512.13 Section 512.13 Foreign Relations BROADCASTING BOARD OF GOVERNORS COLLECTION OF DEBTS UNDER THE DEBT COLLECTION ACT OF 1982 Administrative Offset and Referral to Collection Agencies § 512.13 Exploration of compromise...

  15. 22 CFR 512.13 - Exploration of compromise.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Exploration of compromise. 512.13 Section 512.13 Foreign Relations BROADCASTING BOARD OF GOVERNORS COLLECTION OF DEBTS UNDER THE DEBT COLLECTION ACT OF 1982 Administrative Offset and Referral to Collection Agencies § 512.13 Exploration of compromise...

  16. 5 CFR 1312.30 - Loss or possible compromise.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Loss or possible compromise. 1312.30 Section 1312.30 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION... Classified Information § 1312.30 Loss or possible compromise. Any person who has knowledge of the loss...

  17. 38 CFR 42.46 - Compromise and settlement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Compromise and settlement. 42.46 Section 42.46 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) STANDARDS IMPLEMENTING THE PROGRAM FRAUD CIVIL REMEDIES ACT § 42.46 Compromise and settlement. (a)...

  18. 38 CFR 42.46 - Compromise and settlement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Compromise and settlement. 42.46 Section 42.46 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) STANDARDS IMPLEMENTING THE PROGRAM FRAUD CIVIL REMEDIES ACT § 42.46 Compromise and settlement. (a)...

  19. 5 CFR 1312.30 - Loss or possible compromise.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Loss or possible compromise. 1312.30 Section 1312.30 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION... the information shall be notified of the loss or compromise so that the necessary damage assessment...

  20. 5 CFR 1312.30 - Loss or possible compromise.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Loss or possible compromise. 1312.30 Section 1312.30 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION... the information shall be notified of the loss or compromise so that the necessary damage assessment...

  1. 38 CFR 1.970 - Standards for compromise.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Committee respecting acceptance or rejection of a compromise offer shall be in conformity with the standards in §§ 1.930 through 1.936. In loan guaranty cases the offer of a veteran or other obligor to effect a... shall be reviewed by the Committee. An offer to effect a compromise may be accepted if it is...

  2. 26 CFR 300.3 - Offer to compromise fee.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... taxpayer if the offer is accepted, rejected, withdrawn, or returned as nonprocessable after acceptance for... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Offer to compromise fee. 300.3 Section 300.3... ADMINISTRATION USER FEES § 300.3 Offer to compromise fee. (a) Applicability. This section applies to...

  3. Primary structure of a human mitochondrial protein homologous to the bacterial and plant chaperonins and to the 65-kilodalton mycobacterial antigen.

    PubMed Central

    Jindal, S; Dudani, A K; Singh, B; Harley, C B; Gupta, R S

    1989-01-01

    The complete cDNA for a human mitochondrial protein designated P1, which was previously identified as a microtubule-related protein, has been cloned and sequenced. The deduced amino acid sequence of P1 shows strong homology (40 to 50% identical residues and an additional 20% conservative replacements) to the 65-kilodalton major antigen of mycobacteria, to the GroEL protein of Escherichia coli, and to the ribulose 1,5-bisphosphate carboxylase-oxygenase (rubisco) subunit binding protein of plant chloroplasts. Similar to the case with the latter two proteins, which have been shown to act as chaperonins in the posttranslational assembly of oligomeric protein structures, it is suggested that P1 may play a similar role in mammalian cells. The observed high degree of homology between human P1 and mycobacterial antigen also suggests the possible involvement of this protein in certain autoimmune diseases. Images PMID:2568584

  4. Mycobacterium tuberculosis Chaperonin 10 Is Secreted in the Macrophage Phagosome: Is Secretion Due to Dissociation and Adoption of a Partially Helical Structure at the Membrane?

    PubMed Central

    Fossati, Gianluca; Izzo, Gaetano; Rizzi, Emanuele; Gancia, Emanuela; Modena, Daniela; Moras, Maria Luisa; Niccolai, Neri; Giannozzi, Elena; Spiga, Ottavia; Bono, Letizia; Marone, Piero; Leone, Eugenio; Mangili, Francesca; Harding, Stephen; Errington, Neil; Walters, Christopher; Henderson, Brian; Roberts, Michael M.; Coates, Anthony R. M.; Casetta, Bruno; Mascagni, Paolo

    2003-01-01

    To confirm that Mycobacterium tuberculosis chaperonin 10 (Cpn10) is secreted outside the live bacillus, infected macrophages were examined by electron microscopy. This revealed that the mycobacterial protein accumulates both in the wall of the bacterium and in the matrix of the phagosomes in which ingested mycobacteria survive within infected macrophages. To understand the structural implications underlying this secretion, a structural study of M. tuberculosis Cpn10 was performed under conditions that are generally believed to mimic the membrane environment. It was found that in buffer-organic solvent mixtures, the mycobacterial protein forms two main species, namely, a partially helical monomer that prevails in dilute solutions at room temperature and a dimer that folds into a β-sheet-dominated structure and prevails in either concentrated protein solutions at room temperature or in dilute solutions at low temperature. A partially helical monomer was also found and was completely associated with negatively charged detergents in a micelle-bound state. Remarkably, zwitterionic lipids had no effect on the protein structure. By using N- and C-truncated forms of the protein, the C- and N-terminal sequences were identified as possessing an amphiphilic helical character and as selectively associating with acidic detergent micelles. When the study was extended to other chaperonins, it was found that human Cpn10 is also monomeric and partially helical in dilute organic solvent-buffer mixtures. In contrast, Escherichia coli Cpn10 is mostly dimeric and predominately β-sheet in both dilute and concentrated solutions. Interestingly, human Cpn10 also crosses biological membranes, whereas the E. coli homologue is strictly cytosolic. These results suggest that dissociation to partially helical monomers and interaction with acidic lipids may be two important steps in the mechanism of secretion of M. tuberculosis Cpn10 to the external environment. PMID:12837802

  5. Conversion of an inactive xylose isomerase into a functional enzyme by co-expression of GroEL-GroES chaperonins in Saccharomyces cerevisiae.

    PubMed

    Temer, Beatriz; Dos Santos, Leandro Vieira; Negri, Victor Augusti; Galhardo, Juliana Pimentel; Magalhães, Pedro Henrique Mello; José, Juliana; Marschalk, Cidnei; Corrêa, Thamy Lívia Ribeiro; Carazzolle, Marcelo Falsarella; Pereira, Gonçalo Amarante Guimarães

    2017-09-09

    Second-generation ethanol production is a clean bioenergy source with potential to mitigate fossil fuel emissions. The engineering of Saccharomyces cerevisiae for xylose utilization is an essential step towards the production of this biofuel. Though xylose isomerase (XI) is the key enzyme for xylose conversion, almost half of the XI genes are not functional when expressed in S. cerevisiae. To date, protein misfolding is the most plausible hypothesis to explain this phenomenon. This study demonstrated that XI from the bacterium Propionibacterium acidipropionici becomes functional in S. cerevisiae when co-expressed with GroEL-GroES chaperonin complex from Escherichia coli. The developed strain BTY34, harboring the chaperonin complex, is able to efficiently convert xylose to ethanol with a yield of 0.44 g ethanol/g xylose. Furthermore, the BTY34 strain presents a xylose consumption rate similar to those observed for strains carrying the widely used XI from the fungus Orpinomyces sp. In addition, the tetrameric XI structure from P. acidipropionici showed an elevated number of hydrophobic amino acid residues on the surface of protein when compared to XI commonly expressed in S. cerevisiae. Based on our results, we elaborate an extensive discussion concerning the uncertainties that surround heterologous expression of xylose isomerases in S. cerevisiae. Probably, a correct folding promoted by GroEL-GroES could solve some issues regarding a limited or absent XI activity in S. cerevisiae. The strains developed in this work have promising industrial characteristics, and the designed strategy could be an interesting approach to overcome the non-functionality of bacterial protein expression in yeasts.

  6. Identification of a Novel BBS Gene (BBS12) Highlights the Major Role of a Vertebrate-Specific Branch of Chaperonin-Related Proteins in Bardet-Biedl Syndrome

    PubMed Central

    Stoetzel, Corinne; Muller, Jean; Laurier, Virginie; Davis, Erica E.; Zaghloul, Norann A.; Vicaire, Serge; Jacquelin, Cécile; Plewniak, Frédéric; Leitch, Carmen C.; Sarda, Pierre; Hamel, Christian; de Ravel, Thomy J. L.; Lewis, Richard Alan; Friederich, Evelyne; Thibault, Christelle; Danse, Jean-Marc; Verloes, Alain; Bonneau, Dominique; Katsanis, Nicholas; Poch, Olivier; Mandel, Jean-Louis; Dollfus, Hélène

    2007-01-01

    Bardet-Biedl syndrome (BBS) is primarily an autosomal recessive ciliopathy characterized by progressive retinal degeneration, obesity, cognitive impairment, polydactyly, and kidney anomalies. The disorder is genetically heterogeneous, with 11 BBS genes identified to date, which account for ∼70% of affected families. We have combined single-nucleotide–polymorphism array homozygosity mapping with in silico analysis to identify a new BBS gene, BBS12. Patients from two Gypsy families were homozygous and haploidentical in a 6-Mb region of chromosome 4q27. FLJ35630 was selected as a candidate gene, because it was predicted to encode a protein with similarity to members of the type II chaperonin superfamily, which includes BBS6 and BBS10. We found pathogenic mutations in both Gypsy families, as well as in 14 other families of various ethnic backgrounds, indicating that BBS12 accounts for ∼5% of all BBS cases. BBS12 is vertebrate specific and, together with BBS6 and BBS10, defines a novel branch of the type II chaperonin superfamily. These three genes are characterized by unusually rapid evolution and are likely to perform ciliary functions specific to vertebrates that are important in the pathophysiology of the syndrome, and together they account for about one-third of the total BBS mutational load. Consistent with this notion, suppression of each family member in zebrafish yielded gastrulation-movement defects characteristic of other BBS morphants, whereas simultaneous suppression of all three members resulted in severely affected embryos, possibly hinting at partial functional redundancy within this protein family. PMID:17160889

  7. 15 CFR 904.106 - Compromise of civil penalty.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... be sent to Agency counsel at the address specified in the NOVA. (c) Neither the existence of the... which a NOVA becomes final. (d) NOAA will not compromise, modify, or remit a civil penalty assessed,...

  8. 15 CFR 904.106 - Compromise of civil penalty.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... be sent to Agency counsel at the address specified in the NOVA. (c) Neither the existence of the... which a NOVA becomes final. (d) NOAA will not compromise, modify, or remit a civil penalty assessed,...

  9. 15 CFR 904.106 - Compromise of civil penalty.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... be sent to Agency counsel at the address specified in the NOVA. (c) Neither the existence of the... which a NOVA becomes final. (d) NOAA will not compromise, modify, or remit a civil penalty assessed,...

  10. 15 CFR 904.106 - Compromise of civil penalty.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... be sent to Agency counsel at the address specified in the NOVA. (c) Neither the existence of the... which a NOVA becomes final. (d) NOAA will not compromise, modify, or remit a civil penalty assessed,...

  11. 15 CFR 904.106 - Compromise of civil penalty.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... be sent to Agency counsel at the address specified in the NOVA. (c) Neither the existence of the... which a NOVA becomes final. (d) NOAA will not compromise, modify, or remit a civil penalty assessed,...

  12. RNA differential display of scarless wound healing in fetal rabbit indicates downregulation of a CCT chaperonin subunit and upregulation of a glycophorin-like gene transcript.

    PubMed

    Darden, D L; Hu, F Z; Ehrlich, M D; Gorry, M C; Dressman, D; Li, H S; Whitcomb, D C; Hebda, P A; Dohar, J E; Ehrlich, G D

    2000-03-01

    wound than in the other 3 tissues. A transcript that was downregulated in fetal wound showed very high sequence homology to part of the human gene for the eta subunit of the hetero-oligomeric particle CCT (the chaperonin containing T-complex polypeptide 1 or TCP-1). An upregulated amplimer showed significant DNA sequence homology to glycophorins A and B. One sequence was identified as 28S rRNA. The remaining 4 candidate sequences showed no significant homology to known genes, but 1 had high homology to expressed sequence tags of unknown function. With careful experimental design and proper controls and verifications, differential display of RNA expression is a potentially powerful method of finding genes that specifically regulate a particular physiological process such as fetal wound healing. No a priori knowledge of what genes might be involved, or why, is necessary. This study indicates that downregulation of a gene that codes for a chaperonin subunit and upregulation of several other genes may be involved in the striking scarless character of wound healing in the mammalian fetus. Results suggest the hypothesis that downregulation of the CCT chaperonin in fetal wound may inhibit the formation of myofibroblasts, a cell type that correlates highly with scarring in postnatal wound healing, by preventing the folding of sufficient alpha-smooth muscle actin to form the stress fibers characteristic of these cells.

  13. Alchemy or Science? Compromising Archaeology in the Deep Sea

    NASA Astrophysics Data System (ADS)

    Adams, Jonathan

    2007-06-01

    In the torrid debate between archaeology and treasure hunting, compromise is often suggested as the pragmatic solution, especially for archaeology carried out either in deep water or beyond the constraints that commonly regulate such activities in territorial seas. Both the wisdom and the need for such compromise have even been advocated by some archaeologists, particularly in forums such as the internet and conferences. This paper argues that such a compromise is impossible, not in order to fuel confrontation but simply because of the nature of any academic discipline. We can define what archaeology is in terms of its aims, theories, methods and ethics, so combining it with an activity founded on opposing principles must transform it into something else. The way forward for archaeology in the deep sea does not lie in a contradictory realignment of archaeology’s goals but in collaborative research designed to mesh with emerging national and regional research and management plans.

  14. The acute abdomen in the immune compromised host

    PubMed Central

    Power, Niall

    2008-01-01

    Abstract Recent advances in transplantation, oncology and AIDS therapy have greatly increased life expectancies of patients diagnosed with malignancy, auto-immune disorders and organ failure. However, as this immune compromised population grows, complications of such therapies have become a major source of morbidity and mortality. Classical clinical and laboratory evidence of intra-abdominal pathology may be absent in the immune compromised host. Consequently, the radiologist is increasingly called upon to diagnose acute intra-abdominal complications associated with immunodeficiency. This review explores the aetiology of the acute abdomen in the immune compromised host. The typical radiological appearances of the commonest conditions are illustrated. The challenges and limitations in the radiological diagnosis of these conditions are discussed. PMID:18442955

  15. Compromising positions: emergent neo-Fordisms and embedded gender contracts.

    PubMed

    Gottfried, H

    2000-06-01

    This paper adopts a regulation framework to chart the emergence of neo-Fordism as a flexible accumulation regime and mode of social regulation. Neo-Fordism relies on old Fordist principles as well as incorporating new models of emergent post-Fordisms; old and new social relationships, in their particular combination, specify the trajectory of national variants. I argue that Fordist bargains institutionalized the terms of a compromise between labour, capital and the state. These bargains embedded a male-breadwinner gender contract compromising women's positions and standardizing employment contracts around the needs, interests and authority of men. A focus on compromises and contracts makes visible the differentiated gender effects of work transformation in each country.

  16. Hyperbaric Oxygen Therapy for the Compromised Graft or Flap

    PubMed Central

    Francis, Ashish; Baynosa, Richard C.

    2017-01-01

    Significance: Tissue grafts and flaps are used to reconstruct wounds from trauma, chronic disease, tumor extirpation, burns, and infection. Despite careful surgical planning and execution, reconstructive failure can occur due to poor wound beds, radiation, random flap necrosis, vascular insufficiency, or ischemia–reperfusion (IR). Traumatic avulsions and amputated composite tissues—compromised tissue—may fail from crush injury and excessively large sizes. While never intended, these complications result in tissue loss, additional surgery, accrued costs, and negative psychosocial patient effects. Recent Advances: Hyperbaric oxygen (HBO) has demonstrated utility in the salvage of compromised grafts/flaps. It can increase the likelihood and effective size of composite graft survival, improve skin graft outcomes, and enhance flap survival. Mechanisms underlying these beneficial effects include increased oxygenation, improved fibroblast function, neovascularization, and amelioration of IR injury. Critical Issues: Common strategies for the compromised graft or flap include local wound care, surgical debridement, and repeated reconstruction. These modalities are associated with added costs, time, need for reoperation, morbidity, and psychosocial effects. Preservation of the amputated/avulsed tissues minimizes morbidity and maximizes the reconstructive outcome by salvaging the compromised tissue and obviating additional surgery. HBO is often overlooked as a potential tool that can limit these issues. Future Directions: Animal studies demonstrate a benefit of HBO in the treatment of compromised tissues. Clinical studies support these findings, but are limited to case reports and series. Further research is needed to provide multicenter prospective clinical studies and cost analyses comparing HBO to other adjunctive therapies in the treatment of compromised grafts/flaps. PMID:28116225

  17. Roles of Melatonin in Fetal Programming in Compromised Pregnancies

    PubMed Central

    Chen, Yu-Chieh; Sheen, Jiunn-Ming; Tiao, Miao-Meng; Tain, You-Lin; Huang, Li-Tung

    2013-01-01

    Compromised pregnancies such as those associated with gestational diabetes mellitus, intrauterine growth retardation, preeclampsia, maternal undernutrition, and maternal stress may negatively affect fetal development. Such pregnancies may induce oxidative stress to the fetus and alter fetal development through the epigenetic process that may affect development at a later stage. Melatonin is an oxidant scavenger that reverses oxidative stress during the prenatal period. Moreover, the role of melatonin in epigenetic modifications in the field of developmental programming has been studied extensively. Here, we describe the physiological function of melatonin in pregnancy and discuss the roles of melatonin in fetal programming in compromised pregnancies, focusing on its involvement in redox and epigenetic mechanisms. PMID:23466884

  18. Critical appraisal. Reversal of compromised bonding after bleaching.

    PubMed

    Swift, Edward J

    2012-10-01

    Bleaching with peroxide agents compromises the adhesion of resin-based materials to enamel and dentin. The problem is likely caused by delayed release of oxygen from the teeth that inhibits resin polymerization at the interface. The typical method for avoiding problems with bonding to bleached teeth is simply to delay the bonding procedure for a week or two after bleaching. However, there is evidence that bonding can be done immediately if bleaching is followed by the application of an antioxidant. This Critical Appraisal reviews some of the published reports on the reversal of compromised bonding after bleaching via the use of antioxidants such as sodium ascorbate.

  19. Fuzzy compromise: An effective way to solve hierarchical design problems

    NASA Technical Reports Server (NTRS)

    Allen, J. K.; Krishnamachari, R. S.; Masetta, J.; Pearce, D.; Rigby, D.; Mistree, F.

    1990-01-01

    In this paper, we present a method for modeling design problems using a compromise decision support problem (DSP) incorporating the principles embodied in fuzzy set theory. Specifically, the fuzzy compromise decision support problem is used to study hierarchical design problems. This approach has the advantage that although the system modeled has an element of uncertainty associated with it, the solution obtained is crisp and precise. The efficacy of incorporating fuzzy sets into the solution process is discussed in the context of results obtained for a portal frame.

  20. Identification of a mammalian 10-kDa heat shock protein, a mitochondrial chaperonin 10 homologue essential for assisted folding of trimeric ornithine transcarbamoylase in vitro.

    PubMed Central

    Hartman, D J; Hoogenraad, N J; Condron, R; Høj, P B

    1992-01-01

    We have identified a 10-kDa stress-inducible mitochondrial protein. The protein is synthesized at elevated rates in cultured rat hepatoma cells challenged with heat shock or amino acid analogues and, therefore, designated heat shock protein 10 (Hsp10). Hsp10 was purified to homogeneity from rat liver and found to exhibit a native molecular mass of 65 kDa, as opposed to a monomeric molecular mass of 10,813.4 +/- 0.41 Da. The amino acid sequence of rat Hsp10 disclosed extensive sequence similarity with bacterial chaperonin (Cpn) 10. Rat Hsp10 and Escherichia coli Cpn60 were used to reconstitute functional trimeric rat ornithine transcarbamoylase from a chemically denatured state with high efficiency. This process depended completely upon rat Hsp10 and was abolished in the presence of a nonhydrolyzable ATP analogue. We conclude that Hsp10 is a eukaryotic Cpn10 homologue and, therefore, together with Cpn60 essential for mitochondrial protein biogenesis. The Cpn-mediated protein-folding apparatus, thus, exhibits a high degree of conservation between prokaryotes and mitochondria of higher eukaryotes. Images PMID:1348860

  1. A mitochondrial-like chaperonin 60 gene in Giardia lamblia: evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria.

    PubMed

    Roger, A J; Svärd, S G; Tovar, J; Clark, C G; Smith, M W; Gillin, F D; Sogin, M L

    1998-01-06

    Diplomonads, parabasalids, as represented by trichomonads, and microsporidia are three protist lineages lacking mitochondria that branch earlier than all other eukaryotes in small subunit rRNA and elongation factor phylogenies. The absence of mitochondria and plastids in these organisms suggested that they diverged before the origin of these organelles. However, recent discoveries of mitochondrial-like heat shock protein 70 and/or chaperonin 60 (cpn60) genes in trichomonads and microsporidia imply that the ancestors of these two groups once harbored mitochondria or their endosymbiotic progenitors. In this report, we describe a mitochondrial-like cpn60 homolog from the diplomonad parasite Giardia lamblia. Northern and Western blots reveal that the expression of cpn60 is independent of cellular stress and, except during excystation, occurs throughout the G. lamblia life cycle. Phylogenetic analyses position the G. lamblia cpn60 in a clade that includes mitochondrial and hydrogenosomal cpn60 proteins. The most parsimonious interpretation of these data is that the cpn60 gene was transferred from the endosymbiotic ancestors of mitochondria to the nucleus early in eukaryotic evolution, before the divergence of the diplomonads and trichomonads from other extant eukaryotic lineages. A more complicated explanation requires that these genes originated from distinct alpha-proteobacterial endosymbioses that formed transiently within these protist lineages.

  2. Chaperonins as potential gene regulatory factors. In vitro interaction and solubilization of NifA, the nif transcriptional activator, with GroEL.

    PubMed

    Govezensky, D; Bochkareva, E S; Zamir, A; Girshovich, A S

    1994-05-13

    A previous study (Govezensky, D., Greener, T., and Zamir, A. (1991) J. Bacteriol. 20, 6339-6346) indicated that the chaperonin GroEL was required for maximal expression from nif promoters in Klebsiella pneumoniae and nif-transformed Escherichia coli. That this requirement stemmed from the ability of GroEL to properly fold NifA, the nif transcriptional activator, was first supported by co-immunoprecipitation of NifA in K. pneumoniae extracts with anti-GroEL antibodies. In the present in vitro study, NifA, partially purified from E. coli overexpressing the protein, was diluted from a 6 M urea solution into a refolding buffer in the presence or absence of GroEL. Dilution in the absence of GroEL caused the complete precipitation of NifA. When present in the dilution buffer, GroEL bound NifA and maintained it in a soluble state. GroEL was also found to bind NifA newly synthesized in an in vitro translation system. For both NifA preparations, cochaperonin GroES and ATP promoted release of NifA from GroEL. These results provide evidence for the association of NifA with GroEL and for the role of both GroEL and GroES in the solubilization and thereby folding of the nif transcriptional activator.

  3. Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of the co-chaperonin XoGroES from Xanthomonas oryzae pv. oryzae.

    PubMed

    Doan, Thanh Thi Ngoc; Natarajan, Sampath; Song, Na-Hyun; Kim, Jisun; Kim, Jin-Kwang; Kim, Seung-hwan; Viet, Pham Tan; Kim, Jeong-Gu; Lee, Byoung-Moo; Ahn, Yeh-Jin; Kang, Lin-Woo

    2011-01-01

    Bacterial blight (BB), a devastating disease caused by Xanthomonas oryzae pv. oryzae (Xoo), causes serious production losses of rice in Asian countries. Protein misfolding may interfere with the function of proteins in all living cells and must be prevented to avoid cellular disaster. All cells naturally contain molecular chaperones that assist the unfolded proteins in folding into the native structure. One of the well characterized chaperone complexes is GroEL-GroES. GroEL, which consists of two chambers, captures misfolded proteins and refolds them. GroES is a co-chaperonin protein that assists the GroEL protein as a lid that temporarily closes the chamber during the folding process. Xoo4289, the GroES gene from Xoo, was cloned and expressed for X-ray crystallographic study. The purified protein (XoGroES) was crystallized using the hanging-drop vapour-diffusion method and a crystal diffracted to 2.0 Å resolution. The crystal belonged to the hexagonal space group P6(1), with unit-cell parameters a=64.4, c=36.5 Å. The crystal contains a single molecule in the asymmetric unit, with a corresponding VM of 2.05 Å3 Da(-1) and a solvent content of 39.9%.

  4. Heat shock in Escherichia coli alters the protein-binding properties of the chaperonin groEL by inducing its phosphorylation.

    PubMed

    Sherman MYu; Goldberg, A L

    1992-05-14

    When bacterial or eukaryotic cells are exposed to high temperatures or other harsh conditions, they respond by synthesis of a specific set of heat-shock proteins. Certain heat-shock proteins such as groEL, called 'chaperonins', can prevent misfolding and promote the refolding and proper assembly of unfolded polypeptides generated under harmful conditions. We report here a new aspect of the heat-shock response in Escherichia coli: at high temperatures a fraction of groEL becomes modified covalently, altering its interaction with unfolded proteins. The heat-modified form can be eluted with ATP from an unfolded protein more easily than normal groEL. The critical heat-induced modification seems to be phosphorylation, which is reversed on return to low temperature. Treatment of the modified groEL with phosphatases caused its apparent size, charge and binding properties to resemble those of the unmodified form. Thus during heat shock some groEL is reversibly phosphorylated, which allows its ATP-dependent release from protein substrates in the absence of its usual cofactor (groES), and probably promotes the repair of damaged polypeptides.

  5. Programmed Cell Death Protein 5 Interacts with the Cytosolic Chaperonin Containing Tailless Complex Polypeptide 1 (CCT) to Regulate β-Tubulin Folding* ♦

    PubMed Central

    Tracy, Christopher M.; Gray, Amy J.; Cuéllar, Jorge; Shaw, Tanner S.; Howlett, Alyson C.; Taylor, Ryan M.; Prince, John T.; Ahn, Natalie G.; Valpuesta, José M.; Willardson, Barry M.

    2014-01-01

    Programmed cell death protein 5 (PDCD5) has been proposed to act as a pro-apoptotic factor and tumor suppressor. However, the mechanisms underlying its apoptotic function are largely unknown. A proteomics search for binding partners of phosducin-like protein, a co-chaperone for the cytosolic chaperonin containing tailless complex polypeptide 1 (CCT), revealed a robust interaction between PDCD5 and CCT. PDCD5 formed a complex with CCT and β-tubulin, a key CCT-folding substrate, and specifically inhibited β-tubulin folding. Cryo-electron microscopy studies of the PDCD5·CCT complex suggested a possible mechanism of inhibition of β-tubulin folding. PDCD5 bound the apical domain of the CCTβ subunit, projecting above the folding cavity without entering it. Like PDCD5, β-tubulin also interacts with the CCTβ apical domain, but a second site is found at the sensor loop deep within the folding cavity. These orientations of PDCD5 and β-tubulin suggest that PDCD5 sterically interferes with β-tubulin binding to the CCTβ apical domain and inhibits β-tubulin folding. Given the importance of tubulins in cell division and proliferation, PDCD5 might exert its apoptotic function at least in part through inhibition of β-tubulin folding. PMID:24375412

  6. Interaction of the CD43 Sialomucin with the Mycobacterium tuberculosis Cpn60.2 Chaperonin Leads to Tumor Necrosis Factor Alpha Production.

    PubMed

    Torres-Huerta, Alvaro; Villaseñor, Tomás; Flores-Alcantar, Angel; Parada, Cristina; Alemán-Navarro, Estefanía; Espitia, Clara; Pedraza-Alva, Gustavo; Rosenstein, Yvonne

    2017-03-01

    Mycobacterium tuberculosis is the causal agent of tuberculosis. Tumor necrosis factor alpha (TNF-α), transforming growth factor β (TGF-β), and gamma interferon (IFN-γ) secreted by activated macrophages and lymphocytes are considered essential to contain Mycobacterium tuberculosis infection. The CD43 sialomucin has been reported to act as a receptor for bacilli through its interaction with the chaperonin Cpn60.2, facilitating mycobacterium-macrophage contact. We report here that Cpn60.2 induces both human THP-1 cells and mouse-derived bone marrow-derived macrophages (BMMs) to produce TNF-α and that this production is CD43 dependent. In addition, we present evidence that the signaling pathway leading to TNF-α production upon interaction with Cpn60.2 requires active Src family kinases, phospholipase C-γ (PLC-γ), phosphatidylinositol 3-kinase (PI3K), p38, and Jun N-terminal protein kinase (JNK), both in BMMs and in THP-1 cells. Our data highlight the role of CD43 and Cpn60.2 in TNF-α production and underscore an important role for CD43 in the host-mycobacterium interaction.

  7. Codeswitching and Compromise Strategies: Implications for Lexical Structure.

    ERIC Educational Resources Information Center

    Jake, Janice L.; Myers-Scotton, Carol

    1997-01-01

    Deals with two compromise strategies: (1) embedded language islands (EL Islands), and (2) "bare forms" in code switching (CS) within the projection of complementizer. These elements are discussed within the framework of the Matrix Language Frame Model. Shows how this model provides an explanatory account for the occurrence of both EL…

  8. CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS

    EPA Science Inventory


    CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS. WP Watkinson1, LB Wichers2, JP Nolan1, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, LC Walsh1, ER Lappi1, D Terrell1, R Slade1, AD Ledbetter1, and DL Costa1. 1USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, US...

  9. 5 CFR 1215.32 - Compromise, suspension and termination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Compromise, suspension and termination. 1215.32 Section 1215.32 Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND... to the General Accounting Office (GAO) debts arising from GAO audit exceptions. ...

  10. 32 CFR 2400.33 - Loss or possible compromise.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... TECHNOLOGY POLICY REGULATIONS TO IMPLEMENT E.O. 12356; OFFICE OF SCIENCE AND TECHNOLOGY POLICY INFORMATION... the loss or possible compromise of classified information shall immediately report the circumstances... originated the information as soon as possible so that a damage assessment may be conducted and appropriate...

  11. 32 CFR 2400.33 - Loss or possible compromise.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... TECHNOLOGY POLICY REGULATIONS TO IMPLEMENT E.O. 12356; OFFICE OF SCIENCE AND TECHNOLOGY POLICY INFORMATION... the loss or possible compromise of classified information shall immediately report the circumstances... originated the information as soon as possible so that a damage assessment may be conducted and appropriate...

  12. Compromise solutions between conservation and road building in the tropics.

    PubMed

    Caro, Tim; Dobson, Andrew; Marshall, Andrew J; Peres, Carlos A

    2014-08-18

    Road construction is now common through wilderness and protected areas in tropical and subtropical countries with adverse consequences for their high native biodiversity. Here, we summarize the scope of the problem and advance specific compromise solutions that reconcile development with conservation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. An Item Response Model for Characterizing Test Compromise.

    ERIC Educational Resources Information Center

    Segall, Daniel O.

    2002-01-01

    Developed an item response model for characterizing test-compromise that enables the estimation of item preview and score-gain distributions. In the approach, models parameters and posterior distributions are estimated by Markov Chain Monte Carlo procedures. Simulation study results suggest that when at least some test items are known to be…

  14. CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS

    EPA Science Inventory


    CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS. WP Watkinson1, LB Wichers2, JP Nolan1, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, LC Walsh1, ER Lappi1, D Terrell1, R Slade1, AD Ledbetter1, and DL Costa1. 1USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, US...

  15. 17 CFR 143.5 - Collection by compromise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Collection by compromise. 143.5 Section 143.5 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION COLLECTION OF CLAIMS OWED THE UNITED STATES ARISING FROM ACTIVITIES UNDER THE COMMISSION'S JURISDICTION...

  16. 15 CFR 25.46 - Compromise or settlement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Government is not with the Office of General Counsel, the representative shall forward all settlement offers... as directed by the reviewing official. (c) The authority head has exclusive authority to compromise... recommend settlement terms to the reviewing official, the authority head, or the Attorney General, as...

  17. Whatever It Takes: Health Compromising Behaviors in Female Athletes

    ERIC Educational Resources Information Center

    Waldron, Jennifer J.; Krane, Vikki

    2005-01-01

    The power and performance model of sport stresses a sport ethic of doing "whatever it takes" to win (Coakley, 2004). Uncritical acceptance of this model may lead to various health-compromising behaviors. Employing achievement goal theory, we examine why female athletes may adopt the power and performance approach. An ego motivational climate and a…

  18. 32 CFR 2400.33 - Loss or possible compromise.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Loss or possible compromise. 2400.33 Section 2400.33 National Defense Other Regulations Relating to National Defense OFFICE OF SCIENCE AND TECHNOLOGY POLICY REGULATIONS TO IMPLEMENT E.O. 12356; OFFICE OF SCIENCE AND TECHNOLOGY POLICY...

  19. 32 CFR 2400.33 - Loss or possible compromise.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Loss or possible compromise. 2400.33 Section 2400.33 National Defense Other Regulations Relating to National Defense OFFICE OF SCIENCE AND TECHNOLOGY POLICY REGULATIONS TO IMPLEMENT E.O. 12356; OFFICE OF SCIENCE AND TECHNOLOGY POLICY...

  20. 32 CFR 2400.33 - Loss or possible compromise.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Loss or possible compromise. 2400.33 Section 2400.33 National Defense Other Regulations Relating to National Defense OFFICE OF SCIENCE AND TECHNOLOGY POLICY REGULATIONS TO IMPLEMENT E.O. 12356; OFFICE OF SCIENCE AND TECHNOLOGY POLICY...

  1. Tissue response: biomaterials, dental implants, and compromised osseous tissue.

    PubMed

    Babu RS, Arvind; Ogle, Orrett

    2015-04-01

    Tissue response represents an important feature in biocompatibility in implant procedures. This review article highlights the fundamental characteristics of tissue response after the implant procedure. This article also highlights the tissue response in compromised osseous conditions. Understanding the histologic events after dental implants in normal and abnormal bone reinforces the concept of case selection in dental implants.

  2. 41 CFR 105-70.046 - Compromise or settlement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Compromise or settlement. 105-70.046 Section 105-70.046 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION Regional Offices-General...

  3. Whatever It Takes: Health Compromising Behaviors in Female Athletes

    ERIC Educational Resources Information Center

    Waldron, Jennifer J.; Krane, Vikki

    2005-01-01

    The power and performance model of sport stresses a sport ethic of doing "whatever it takes" to win (Coakley, 2004). Uncritical acceptance of this model may lead to various health-compromising behaviors. Employing achievement goal theory, we examine why female athletes may adopt the power and performance approach. An ego motivational climate and a…

  4. Time-to-Compromise Model for Cyber Risk Reduction Estimation

    SciTech Connect

    Miles A. McQueen; Wayne F. Boyer; Mark A. Flynn; George A. Beitel

    2005-09-01

    We propose a new model for estimating the time to compromise a system component that is visible to an attacker. The model provides an estimate of the expected value of the time-to-compromise as a function of known and visible vulnerabilities, and attacker skill level. The time-to-compromise random process model is a composite of three subprocesses associated with attacker actions aimed at the exploitation of vulnerabilities. In a case study, the model was used to aid in a risk reduction estimate between a baseline Supervisory Control and Data Acquisition (SCADA) system and the baseline system enhanced through a specific set of control system security remedial actions. For our case study, the total number of system vulnerabilities was reduced by 86% but the dominant attack path was through a component where the number of vulnerabilities was reduced by only 42% and the time-to-compromise of that component was increased by only 13% to 30% depending on attacker skill level.

  5. Myocardial microvascular permeability, interstitial oedema, and compromised cardiac function

    PubMed Central

    Dongaonkar, Ranjeet M.; Stewart, Randolph H.; Geissler, Hans J.; Laine, Glen A.

    2010-01-01

    The heart, perhaps more than any other organ, is exquisitely sensitive to increases in microvascular permeability and the accumulation of myocardial interstitial oedema fluid. Whereas some organs can cope with profound increases in the interstitial fluid volume or oedema formation without a compromise in function, heart function is significantly compromised with only a few percent increase in the interstitial fluid volume. This would be of little consequence if myocardial oedema were an uncommon pathology. On the contrary, myocardial oedema forms in response to many disease states as well as clinical interventions such as cardiopulmonary bypass and cardioplegic arrest common to many cardiothoracic surgical procedures. The heart's inability to function effectively in the presence of myocardial oedema is further confounded by the perplexing fact that the resolution of myocardial oedema does not restore normal cardiac function. We will attempt to provide some insight as to how microvascular permeability and myocardial oedema formation compromise cardiac function and discuss the acute changes that might take place in the myocardium to perpetuate compromised cardiac function following oedema resolution. We will also discuss compensatory changes in the interstitial matrix of the heart in response to chronic myocardial oedema and the role they play to optimize myocardial function during chronic oedemagenic disease. PMID:20472566

  6. 49 CFR 107.327 - Compromise and settlement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Compromise and settlement. 107.327 Section 107.327 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... consent agreement to the Chief Counsel. If the Chief Counsel accepts the agreement, he issues an order...

  7. 49 CFR 107.327 - Compromise and settlement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Compromise and settlement. 107.327 Section 107.327 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... consent agreement to the Chief Counsel. If the Chief Counsel accepts the agreement, he issues an order...

  8. 49 CFR 107.327 - Compromise and settlement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Compromise and settlement. 107.327 Section 107.327 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... consent agreement to the Chief Counsel. If the Chief Counsel accepts the agreement, he issues an order...

  9. 40 CFR 13.25 - Standards for compromise.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 13.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL CLAIMS COLLECTION STANDARDS... claim, either because of the legal issues involved or a bona fide dispute as to the facts. The amount accepted in compromise in such cases will fairly reflect the probability of prevailing on the legal issues...

  10. 42 CFR 401.613 - Compromise of claims.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Compromise of claims. 401.613 Section 401.613 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... present or prospective ability to pay the full amount of the claim within a reasonable time. (2...

  11. 19 CFR 161.5 - Compromise of Government claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Compromise of Government claims. 161.5 Section 161.5 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF... distance from a Federal Reserve bank may perfect his offer by tendering a bank draft for the amount of the...

  12. 5 CFR 185.146 - Compromise or settlement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Compromise or settlement. 185.146 Section 185.146 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROGRAM... pendency of any action to collect penalties and assessments under § 185.143. (d) The Attorney General has...

  13. Vehicle influence on permeation through intact and compromised skin.

    PubMed

    Gujjar, Meera; Banga, Ajay K

    2014-09-10

    The purpose of this study was to compare the transdermal permeation of a model compound, diclofenac diethylamine, from a hydrophilic and lipophilic vehicle across in vitro models simulating compromised skin. Mineral oil served as a lipophilic vehicle while 10mM phosphate buffered saline served as a hydrophilic vehicle. Compromised skin was simulated by tape stripping, delipidization, or microneedle application and compared with intact skin as a control. Transepidermal water loss was measured to assess barrier function. Skin compromised with tape stripping and delipidization significantly (p<0.05) increased permeation of diclofenac diethylamine compared to intact and microneedle treated skin with phosphate buffered saline vehicle. A similar trend in permeation was observed with mineral oil as the vehicle. For both vehicles, permeation across skin increased in the same order and correlated with degree of barrier impairment as indicated by transepidermal water loss values: intactcompromised skin.

  14. 45 CFR 30.22 - Bases for compromise.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Bases for compromise. 30.22 Section 30.22 Public... an amount that bears a reasonable relation to the amount that can be recovered by enforced collection... amount claimed, either because of the legal issues involved or because of a bona fide dispute as to...

  15. Balloon kyphoplasty for osteoporotic spinal fractures with middle column compromise.

    PubMed

    Gan, Minfeng; Zou, Jun; Zhu, Xuesong; Wang, Genlin; Yang, Huilin

    2014-10-01

    Balloon kyphoplasty (BKP) is an effective method for osteoporotic vertebral compression fractures. However osteoporotic spinal fractures with middle column compromise are mentioned as a relative contraindication to BKP. Thus we investigated the safety and efficacy of BKP in the treatment of osteoporotic spinal fractures with middle column compromise but without neurological deficit. In this retrospective study, 45 patients who suffered osteoporotic fractures with middle column compromise but without neurological deficits were treated by BKP from May 2007 to December 2010. The final follow-ups were finished during the time of July 2011-September 2011. The mean follow-up period was 20.2 months. The height of the compromised vertebral body, the kyphotic angle and spinal canal compromise were measured before surgery, one day after surgery, and at the final follow-up. A visual analogue scale (VAS) and the Oswestry disability index (ODI) were chosen to evaluate pain and functional activity. The mean VAS and ODI scores improved significantly from pre- to post-operation (p<0.05), and this improvement was sustained at the final follow-up. The mean anterior vertebral body height ratio improved from 57.6%± 11.8% preoperatively to 86.2%± 12.2% postoperatively (p<0.05), so did the mean middle vertebral body height ratio. The kyphotic angle improved from 16.3° ± 3.7° preoperatively to 9.3° ± 2.6° postoperatively (p<0.05). At final follow-up, BKP stabilised vertebral height and prevented further kyphotic deformity. While there were no differences in spinal canal compromise between pre-operation and one day after surgery (p>0.05), there was a significant difference from the measurement at the final follow-up (p<0.05). BKP is a safe and effective method for osteoporotic spinal fractures with middle column compromise but without neurological deficit. Spontaneous remodelling of the spinal canal also occurs after BKP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Securing Single Points of Compromise (SPoC)

    SciTech Connect

    Belangia, David Warren

    2015-06-25

    Securing the Single Points of Compromise that provide central services to the institution’s environment is paramount to success when trying to protect the business. (Fisk, 2014) Time Based Security mandates protection (erecting and ensuring effective controls) that last longer than the time to detect and react to a compromise. When enterprise protections fail, providing additional layered controls for these central services provides more time to detect and react. While guidance is readily available for securing the individual critical asset, protecting these assets as a group is not often discussed. Using best business practices to protect these resources as individual assets while leveraging holistic defenses for the group increases the opportunity to maximize protection time, allowing detection and reaction time for the SPoCs that is commensurate with the inherent risk of these centralized services.

  17. Creating clones, kids & chimera: liberal democratic compromise at the crossroads.

    PubMed

    Adams, Nathan A

    2004-01-01

    The objective of this article is to find middle ground between the supporters and opponents of biotechnology by perpetuating the existing legal compromise pertaining to the complete range of health and welfare doctrines relevant to the biotechnological industry. The author aspires neither to add to nor detract from this liberal democratic consensus, but to preserve its constitutive balance between positivism and natural law and over-regulation and under-regulation in the hopes of stabilizing new political fault lines developing around the few biotechnological innovations already grabbing headlines. The most feasible solution is to extend the existing liberal democratic compromise with respect to equal protection, reproductive rights, the First Amendment, human subject experimentation, patent law, and parental rights. This includes banning or monopolizing certain biotechnologies and extending substantive special respect to the ex vivo living human embryo. Biotechnology must not be left to regulate itself.

  18. The ethics of moral compromise for stem cell research policy.

    PubMed

    Master, Zubin; Crozier, G K D

    2012-03-01

    In the US, stem cell research is at a moral impasse-many see this research as ethically mandated due to its potential for ameliorating major diseases, while others see this research as ethically impermissible because it typically involves the destruction of embryos and use of ova from women. Because their creation does not require embryos or ova, induced pluripotent stem cells offer the most promising path for addressing the main ethical objections to stem cell research; however, this technology is still in development. In order for scientists to advance induced pluripotent stem cell research to a point of translational readiness, they must continue to use ova and embryos in the interim. How then are we to ethically move forward with stem cell research? We argue that there is personal integrity and value in adopting a 'moral compromise' as a means for moving past the moral impasse in stem cell research. In a moral compromise, each party concedes part of their desired outcome in order to engage in a process that respects the values and desires of all parties equitably. Whereas some contend that moral compromise in stem cell research necessarily involves self-contradiction or loss of personal integrity, we argue that in the US context, stem cell research satisfies many of the key pre-conditions of an effective moral compromise. To illustrate our point, we offer a model solution wherein eggs and embryos are temporarily used until non-egg and non-embryonic sources of pluripotent stem cells are developed to a state of translational readiness.

  19. Adaptive Design of a Decision Support System for Compromise Assessment.

    DTIC Science & Technology

    1987-03-01

    for a reasonable amount of time to pro - vide continuity to the system. This lack of continuity was a con - tributing factor to the current problem of...compromise assess- ments. The only requirements specified by SAC are that the following general topics be discussed: * Currency /accuracy • Relationship to...be presented to SAC. 9. .* k, - .".4. 4. A. Ill. Methodology The following four objectives (as discussed in Chapter I) pro - vide a course of action

  20. Splitting the difference? Principled compromise and assisted dying.

    PubMed

    Huxtable, Richard

    2014-11-01

    Compromise on moral matters attracts ambivalent reactions, since it seems at once laudable and deplorable. When a hotly-contested phenomenon like assisted dying is debated, all-or-nothing positions tend to be advanced, with little thought given to the desirability of, or prospects for, compromise. In response to recent articles by Søren Holm and Alex Mullock, in this article I argue that principled compromise can be encouraged even in relation to this phenomenon, provided that certain conditions are present (which I suggest they are). In order to qualify as appropriately principled, the ensuing negotiations require disputants to observe three constraints: they should be suitably reflective, reliable and respectful in their dealings with one another. The product that will result from such a process will also need to split the difference between the warring parties. In assisted dying, I argue that a reduced offence of 'compassionate killing' can achieve this. I acknowledge, however, that splitting the difference can induce splitting headaches, as there remain certain questions to be answered. Hopefully, however, sufficient work is done here to defend attempts to occupy the middle ground, whether these relate to assisted dying specifically or to other disputed moral matters. © 2013 John Wiley & Sons Ltd.

  1. Potential Soviet compromise on ballistic missile defense. Final report

    SciTech Connect

    Nguyen, H.P.

    1989-11-01

    The body of this research memorandum was written before the Baker-Shevardnadze meeting in Wyoming. It presented evidence suggesting that the Soviet Union might agree to a compromise at the Wyoming meeting that defers the issue of ballistic missile defense (BMD) negotiations to a later stage in arms reductions, thus facilitating a first-stage cut in offensive arms without an explicit Soviet endorsement of the Strategic Defense Initiative (SDI). Through this compromise, offensive arms reductions should first be delinked from an agreement on BMD, and then be relinked during the second stage of deeper cuts. Therefore, negotiations on limiting BMD systems, though deterred, are deemed inevitable if the U.S. persists in deploying a strategic defense system (SDS). Moreover, some Soviet arms controllers already look beyond the first stage to the prospect of negotiated transition into a strategic defense environment (i.e., a reliance on defensive deterrence). In this approach, Wyoming, then, was expected to be only a first move in the Soviet negotiating strategy for a grand compromise on strategic defense. As explained in the afterword added to the paper, the actual events at Wyoming seem consistent with that interpretation.

  2. Placental angiogenesis in sheep models of compromised pregnancy

    PubMed Central

    Reynolds, Lawrence P; Borowicz, Pawel P; Vonnahme, Kimberly A; Johnson, Mary Lynn; Grazul-Bilska, Anna T; Redmer, Dale A; Caton, Joel S

    2005-01-01

    Because the placenta is the organ that transports nutrients, respiratory gases and wastes between the maternal and fetal systems, development of its vascular beds is essential to normal placental function, and thus in supporting normal fetal growth. Compromised fetal growth and development have adverse health consequences during the neonatal period and throughout adult life. To establish the role of placental angiogenesis in compromised pregnancies, we first evaluated the pattern of placental angiogenesis and expression of angiogenic factors throughout normal pregnancy. In addition, we and others have established a variety of sheep models to evaluate the effects on fetal growth of various factors including maternal nutrient excess or deprivation and specific nutrients, maternal age, maternal and fetal genotype, increased numbers of fetuses, environmental thermal stress, and high altitude (hypobaric) conditions. Although placental angiogenesis is altered in each of these models in which fetal growth is adversely affected, the specific effect on placental angiogenesis depends on the type of ‘stress’ to which the pregnancy is subjected, and also differs between the fetal and maternal systems and between genotypes. We believe that the models of compromised pregnancy and the methods described in this review will enable us to develop a much better understanding of the mechanisms responsible for alterations in placental vascular development. PMID:15760944

  3. The Interactions of Allium sativum leaf agglutinin with a chaperonin group of unique receptor protein isolated from a bacterial endosymbiont of the mustard aphid.

    PubMed

    Banerjee, Santanu; Hess, Daniel; Majumder, Pralay; Roy, Debjani; Das, Sampa

    2004-05-28

    The homopteran sucking insect, Lipaphis erysimi (mustard aphid) causes severe damage to various crops. This pest not only affects plants by sucking on the phloem, but it also transmits single-stranded RNA luteoviruses while feeding, which cause disease and damage in the crop. The mannose-binding Allium sativum (garlic) leaf lectin has been found to be a potent control agent of L. erysimi. The lectin receptor protein isolated from brush border membrane vesicle of insect gut was purified to determine the mechanism of lectin binding to the gut. Purified receptor was identified as an endosymbiotic chaperonin, symbionin, using liquid chromatography-tandem mass spectrometry. Symbionin from endosymbionts of other aphid species have been reported to play a significant role in virus transmission by binding to the read-through domain of the viral coat protein. To understand the molecular interactions of the said lectin and this unique symbionin molecule, the model structures of both molecules were generated using the Modeller program. The interaction was confirmed through docking of the two molecules forming a complex. A surface accessibility test of these molecules demonstrated a significant reduction in the accessibility of the complex molecule compared with that of the free symbionin molecule. This reduction in surface accessibility may have an effect on other molecular interactive processes, including "symbionin virion recognition", which is essential for such symbionin-mediated virus transmission. Thus, garlic leaf lectin provides an important component of a crop management program by controlling, on one hand, aphid attack and on the other hand, symbionin-mediated luteovirus transmission.

  4. Affinity chromatography of GroEL chaperonin based on denatured proteins: role of electrostatic interactions in regulation of GroEL affinity for protein substrates.

    PubMed

    Marchenko, N Iu; Marchenkov, V V; Kaĭsheva, A L; Kashparov, I A; Kotova, N V; Kaliman, P A; Semisotnov, G V

    2006-12-01

    The chaperonin GroEL of the heat shock protein family from Escherichia coli cells can bind various polypeptides lacking rigid tertiary structure and thus prevent their nonspecific association and provide for acquisition of native conformation. In the present work we studied the interaction of GroEL with six denatured proteins (alpha-lactalbumin, ribonuclease A, egg lysozyme in the presence of dithiothreitol, pepsin, beta-casein, and apocytochrome c) possessing negative or positive total charge at neutral pH values and different in hydrophobicity (affinity for a hydrophobic probe ANS). To prevent the influence of nonspecific association of non-native proteins on their interaction with GroEL and make easier the recording of the complexing, the proteins were covalently attached to BrCN-activated Sepharose. At low ionic strength (lower than 60 mM), tight binding of the negatively charged denatured proteins with GroEL (which is also negatively charged) needed relatively low concentrations (approximately 10 mM) of bivalent cations Mg2+ or Ca2+. At the high ionic strength (approximately 600 mM), a tight complex was produced also in the absence of bivalent cations. In contrast, positively charged denatured proteins tightly interacted with GroEL irrespectively of the presence of bivalent cations and ionic strength of the solution (from 20 to 600 mM). These features of GroEL interaction with positively and negatively charged denatured proteins were confirmed by polarized fluorescence (fluorescence anisotropy). The findings suggest that the affinity of GroEL for denatured proteins can be determined by the balance of hydrophobic and electrostatic interactions.

  5. Chaperonin-containing T-complex Protein 1 Subunit ζ Serves as an Autoantigen Recognized by Human Vδ2 γδ T Cells in Autoimmune Diseases.

    PubMed

    Chen, Hui; You, Hongqin; Wang, Lifang; Zhang, Xuan; Zhang, Jianmin; He, Wei

    2016-09-16

    Human γδ T cells recognize conserved endogenous and stress-induced antigens typically associated with autoimmune diseases. However, the role of γδ T cells in autoimmune diseases is not clear. Few autoimmune disease-related antigens recognized by T cell receptor (TCR) γδ have been defined. In this study, we compared Vδ2 TCR complementarity-determining region 3 (CDR3) between systemic lupus erythematosus (SLE) patients and healthy donors. Results show that CDR3 length distribution differed significantly and displayed oligoclonal characteristics in SLE patients when compared with healthy donors. We found no difference in the frequency of Jδ gene fragment usage between these two groups. According to the dominant CDR3δ sequences in SLE patients, synthesized SL2 peptides specifically bound to human renal proximal tubular epithelial cell line HK-2; SL2-Vm, a mutant V sequence of SL2, did not bind. We identified the putative protein ligand chaperonin-containing T-complex protein 1 subunit ζ (CCT6A) using SL2 as a probe in HK-2 cell protein extracts by affinity chromatography and liquid chromatography-electrospray ionization-tandem mass spectrometry analysis. We found CCT6A expression on the surface of HK-2 cells. Cytotoxicity of only Vδ2 γδ T cells to HK-2 cells was blocked by anti-CCT6A antibody. Finally, we note that CCT6A concentration was significantly increased in plasma of SLE and rheumatoid arthritis patients. These data suggest that CCT6A is a novel autoantigen recognized by Vδ2 γδ T cells, which deepens our understanding of mechanisms in autoimmune diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Chaperonin containing T-complex polypeptide subunit eta is a potential marker of joint contracture: an experimental study in the rat.

    PubMed

    He, Ronghan; Wang, Zhe; Lu, Yunxiang; Huang, Junqi; Ren, Jianhua; Wang, Kun

    2015-11-01

    Joint contracture is a fibroproliferative disorder that restricts joint mobility, resulting in tissue degeneration and deformity. However, the etiology of joint contracture is still unknown. Chaperonin containing T-complex polypeptide subunit eta (CCT-eta) is reported to increase in fibrotic diseases. The purpose of this study was to investigate whether CCT-eta is implicated in joint contracture and to determine the role of CCT-eta in the progression of joint contracture by analyzing a rat model. We immobilized the left knee joint of rat by internal fixation for 8 weeks. The non-immobilized right leg served as a control. The range of motion (ROM) of the knee was investigated. Fibroblasts were obtained from the posterior joint capsule of the joints. The outcome was followed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, fibroblast migration assay, and collagen assay. The effect of CCT-eta on the functions of fibroblasts was observed by utilizing a short inhibitory RNA (siRNA) targeting CCT-eta. The ROM of the immobilized joints was significantly limited compared to the contralateral joints (p < 0.05). Fibroblasts derived from the contractive joints showed higher mRNA and protein expressions of CCT-eta in parallel with alpha-smooth muscle actin (α-SMA) compared to the cells from the contralateral knees (p < 0.05). siRNA-mediated downregulation of CCT-eta inhibited the expressions of both CCT-eta and α-SMA. Moreover, the reduction of CCT-eta also significantly decreased fibroblast functions such as cell mobility and collagen synthesis (all p < 0.05). Our findings indicate that CCT-eta appears to be a potential marker of joint contracture disease.

  7. Effects of a Mutation in the HSPE1 Gene Encoding the Mitochondrial Co-chaperonin HSP10 and Its Potential Association with a Neurological and Developmental Disorder

    PubMed Central

    Bie, Anne S.; Fernandez-Guerra, Paula; Birkler, Rune I. D.; Nisemblat, Shahar; Pelnena, Dita; Lu, Xinping; Deignan, Joshua L.; Lee, Hane; Dorrani, Naghmeh; Corydon, Thomas J.; Palmfeldt, Johan; Bivina, Liga; Azem, Abdussalam; Herman, Kristin; Bross, Peter

    2016-01-01

    We here report molecular investigations of a missense mutation in the HSPE1 gene encoding the HSP10 subunit of the HSP60/ HSP10 chaperonin complex that assists protein folding in the mitochondrial matrix. The mutation was identified in an infant who came to clinical attention due to infantile spasms at 3 months of age. Clinical exome sequencing revealed heterozygosity for a HSPE1 NM_002157.2:c.217C>T de novo mutation causing replacement of leucine with phenylalanine at position 73 of the HSP10 protein. This variation has never been observed in public exome sequencing databases or the literature. To evaluate whether the mutation may be disease-associated we investigated its effects by in vitro and ex vivo studies. Our in vitro studies indicated that the purified mutant protein was functional, yet its thermal stability, spontaneous refolding propensity, and resistance to proteolytic treatment were profoundly impaired. Mass spectrometric analysis of patient fibroblasts revealed barely detectable levels of HSP10-p.Leu73Phe protein resulting in an almost 2-fold decrease of the ratio of HSP10 to HSP60 subunits. Amounts of the mitochondrial superoxide dismutase SOD2, a protein whose folding is known to strongly depend on the HSP60/HSP10 complex, were decreased to approximately 20% in patient fibroblasts in spite of unchanged SOD2 transcript levels. As a likely consequence, mitochondrial superoxide levels were increased about 2-fold. Although, we cannot exclude other causative or contributing factors, our experimental data support the notion that the HSP10-p.Leu73Phe mutation could be the cause or a strong contributing factor for the disorder in the described patient. PMID:27774450

  8. Neonatal Airway Compromise by a Giant Cervicothoracic Venous Haemangioma

    PubMed Central

    Shenoy, Janardhan; Coutinho, Anita; Pai, Suresh; Rai, Santosh PV

    2017-01-01

    Haemangiomas are most common non-malignant vascular tumours of infancy. Here, we describe an antenatally detected mass over the neck causing compressive respiratory compromise at birth requiring resuscitative measures at birth. The mass showed increased vascularity on Contrast Enhanced Computed Tomography (CECT) with extension upto superior mediastinum. Surgical excision was required following failure to medical measures with steroids and propranolol. Histopathology confirmed it to be a venous haemangioma. This case highlights that these benign lesions may reach large sizes and antenatal detection may help in planning effective delivery and resuscitative measures. PMID:28384953

  9. Periodontics: 8. Periodontal problems associated with compromised anterior teeth.

    PubMed

    Byrne, Patrick J; Irwin, Chris; Mullally, Brian; Allen, Edith; Ziada, Hassan

    2008-01-01

    Periodontal disease can significantly impact on the appearance of the anterior teeth. Prior to any definitive treatment, stabilization of the periodontal condition is a requirement. Treatment options can range from the placement of simple restorations, through orthodontic realignment, to the extraction and replacement of hopeless teeth. Each treatment plan must be individually tailored to the patient and level of periodontal disease, and must include provision for maintenance periodontal therapy. Periodontal diseases may compromise the prognosis of anterior teeth. Management is challenging and clinicians should take into consideration the short and long-term survival in treatment planning.

  10. Compromise budget gives extra funding for HIV programs.

    PubMed

    1999-06-25

    California lawmakers will vote soon on the proposed 1999-2000 State budget that would increase funding for HIV prevention, treatment, and housing programs by $16.9 million. The Senate and Assembly did not originally agree on the appropriation, but the Budget Conference Committee resolved the dispute. Details of the compromise are included. The plan must now go back to both chambers for final action, and the California HIV Advocacy Coalition is optimistic the budget measures will reach the governor's office intact. Governor Gray Davis has promised that the budget will be enacted by the start of the next fiscal year.

  11. Compromise - An effective approach for conceptual aircraft design

    NASA Technical Reports Server (NTRS)

    Mistree, Farrokh; Marinopoulos, Stergios; Jackson, david; Shupe, Jon

    1987-01-01

    The Decision Support Problem (DSP) technique for aircraft design is presently demonstrated through the development of a compromise DSP template for the conceptual design of subsonic transport aircraft. System variables are wing span and area, fuselage diameter and length, takeoff weight, and installed thrust. Such system constraints as range and wing loading are represented algebraically using standard subsonic aircraft theory, and economic efficiency is modeled in terms of rates-of-return. The DSP template thus obtained has been tested and validated using the known mission requirements and design constants of the B 727-200 airliner.

  12. Congenital Microstomia in a Neonate with Impending Respiratory Compromise

    PubMed Central

    Nguyen, Khoa N.; Semenov, Igor; Blasiole, Brian; Robison, Jacob G.; Chi, David H.

    2014-01-01

    Microstomia is the term used to describe a reduction in the size of the oral aperture that is severe enough to compromise quality of life, nutrition, and cosmesis. Few cases of congenital microstomia have been reported as most microstomia cases are due to burn injuries. We are presenting a case of a neonate who was found to be in respiratory distress with severe congenital microstomia from no known cause. This case illustrates the rarity of this type of pathologic anatomy as well as the teamwork and tools necessary to treat these patients. PMID:25610661

  13. Methamphetamine compromises gap junctional communication in astrocytes and neurons

    PubMed Central

    Castellano, Paul; Nwagbo, Chisom; Martinez, Luis R.; Eugenin, Eliseo A.

    2016-01-01

    Methamphetamine (meth) is a central nervous system (CNS) stimulant that results in psychological and physical dependency. The long-term effects of meth within the CNS include neuronal plasticity changes, blood–brain barrier compromise, inflammation, electrical dysfunction, neuronal/glial toxicity, and an increased risk to infectious diseases including HIV. Most of the reported meth effects in the CNS are related to dysregulation of chemical synapses by altering the release and uptake of neurotransmitters, especially dopamine, norepinephrine, and epinephrine. However, little is known about the effects of meth on connexin (Cx) containing channels, such as gap junctions (GJ) and hemichannels (HC). We examined the effects of meth on Cx expression, function, and its role in NeuroAIDS. We found that meth altered Cx expression and localization, decreased GJ communication between neurons and astrocytes, and induced the opening of Cx43/Cx36 HC. Furthermore, we found that these changes in GJ and HC induced by meth treatment were mediated by activation of dopamine receptors, suggesting that dysregulation of dopamine signaling induced by meth is essential for GJ and HC compromise. Meth-induced changes in GJ and HC contributed to amplified CNS toxicity by dysregulating glutamate metabolism and increasing the susceptibility of neurons and astrocytes to bystander apoptosis induced by HIV. Together, our results indicate that connexin containing channels, GJ and HC, are essential in the pathogenesis of meth and increase the sensitivity of the CNS to HIV CNS disease. PMID:26953131

  14. Voices of discontent? Conscience, compromise, and assisted dying.

    PubMed

    Huxtable, Richard; Mullock, Alexandra

    2015-01-01

    If some form of assisted dying is to be legalised, we are likely to hear voices of discontent, not least from the medical profession and some of its members, who might be expected to provide the service. The profession generally favours a position of opposition, premised on an ethic of 'caring not killing', which might be said to convey its 'professional conscience'. There will, of course, also be individual conscientious objectors. In this article, we initially explore the nature and sources of conscience and we argue that conscience does merit respect. We also recognise that professionals, qua professionals, are bound to serve their patients, some of whom will want (and may be entitled to) that which their doctors do not wish to provide. Reflecting on the different values in issue, we suggest that there is a case for principled compromise which would afford professionals a limited right to conscientiously object, while also protecting patients. We then relate these reflections to assisted dying specifically. In the absence of any definitive steer from the purported integrity of medicine, we suspect that the profession could adopt a neutral stance on this divisive issue. We nevertheless anticipate individual objections if the law does move to embrace assisted dying, and we argue that such objections should be respected, according to the terms of the compromise model we defend. © The Author [2015]. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Telomere shortening and metabolic compromise underlie dystrophic cardiomyopathy

    PubMed Central

    Chang, Alex Chia Yu; Ong, Sang-Ging; LaGory, Edward L.; Kraft, Peggy E.; Giaccia, Amato J.; Wu, Joseph C.; Blau, Helen M.

    2016-01-01

    Duchenne muscular dystrophy (DMD) is an incurable X-linked genetic disease that is caused by a mutation in the dystrophin gene and affects one in every 3,600 boys. We previously showed that long telomeres protect mice from the lethal cardiac disease seen in humans with the same genetic defect, dystrophin deficiency. By generating the mdx4cv/mTRG2 mouse model with “humanized” telomere lengths, the devastating dilated cardiomyopathy phenotype seen in patients with DMD was recapitulated. Here, we analyze the degenerative sequelae that culminate in heart failure and death in this mouse model. We report progressive telomere shortening in developing mouse cardiomyocytes after postnatal week 1, a time when the cells are no longer dividing. This proliferation-independent telomere shortening is accompanied by an induction of a DNA damage response, evident by p53 activation and increased expression of its target gene p21 in isolated cardiomyocytes. The consequent repression of Pgc1α/β leads to impaired mitochondrial biogenesis, which, in conjunction with the high demands of contraction, leads to increased oxidative stress and decreased mitochondrial membrane potential. As a result, cardiomyocyte respiration and ATP output are severely compromised. Importantly, treatment with a mitochondrial-specific antioxidant before the onset of cardiac dysfunction rescues the metabolic defects. These findings provide evidence for a link between short telomere length and metabolic compromise in the etiology of dilated cardiomyopathy in DMD and identify a window of opportunity for preventive interventions. PMID:27799523

  16. Frontostriatal fiber bundle compromise in HIV infection without dementia

    PubMed Central

    Pfefferbaum, Adolf; Rosenbloom, Margaret J.; Rohlfing, Torsten; Kemper, Carol A.; Deresinski, Stanley; Sullivan, Edith V.

    2010-01-01

    Background Quantitative fiber tracking derived from diffusion tensor imaging (DTI) was used to determine whether white matter association, projection, or commissural tracts are affected in nondemented individuals with HIV infection and to identify the regional distribution of sparing and impairment of fiber systems. Methods DTI measured fractional anisotropy and diffusivity, quantified separately for longitudinal (λL) diffusivity (index of axonal injury) and transverse (λT) diffusivity (index of myelin injury), in 11 association and projection white matter tracts and six commissural tracts in 29 men and 13 women with HIV infection and 88 healthy, age-matched controls (42 men and 46 women). Results The total group of HIV-infected individuals had higher diffusivity (principally longitudinal) than controls in the posterior sectors of the corpus callosum, internal and external capsules, and superior cingulate bundles. High longitudinal diffusivity, indicative of axonal compromise, was especially prominent in posterior callosal sectors, fornix, and superior cingulate bundle in HIV with AIDS. Unmedicated patients had notably high transverse diffusivity, indicative of myelin compromise, in the occipital forceps, inferior cingulate bundle, and superior longitudinal fasciculus. Pontocerebellar projection fibers were resistant to HIV effects as were commissural fibers coursing through premotor and sensorimotor callosal sectors. Conclusion This quantitative survey of brain fiber tract integrity indicates that even nondemented HIV patients can have neuroradiological evidence for damage to association and commissural tracts. These abnormalities were vulnerable to exacerbation with AIDS and possibly mitigated by HAART. PMID:19730350

  17. Placental Abruption With Delayed Fetal Compromise in Maternal Acetaminophen Toxicity.

    PubMed

    Taney, Juliana; Anastasio, Hannah; Paternostro, Amanda; Berghella, Vincenzo; Roman, Amanda

    2017-07-01

    After maternal acetaminophen overdose, fetal fulminant liver failure, stillbirth, neonatal death, or preterm delivery may occur. A 27-year-old woman, gravida 2 para 1, presented at 28 weeks of gestation after unintentional acetaminophen overdose. Four days after ingestion, her laboratory values worsened, including serum aspartate aminotransferase of 5,460 units/L, alanine aminotransferase of 4,936 units/L, and international normalized ratio of 2.9. On day 6 after ingestion, fetal monitoring showed minimal variability with repetitive variable and late decelerations, which prompted cesarean delivery when a hematoma was noted on the maternal placental surface, consistent with placental abruption. The neonate showed no evidence of hepatic dysfunction. Review of the literature suggests that maternal acetaminophen overdose in the second and third trimester is associated with a 5% incidence of fetal compromise (mostly the result of nonreassuring fetal status leading to delivery or stillbirth) occurring within 6 days of ingestion. Maternal acetaminophen overdose can be associated with delayed fetal compromise, suggesting the importance of continued fetal surveillance several days after ingestion.

  18. Orthodontic management of dentition in patients with periodontally compromised dentition

    PubMed Central

    Panwar, Mohinder; Jayan, B.; Arora, Vimal; Singh, Sukhdeep

    2014-01-01

    Background: An increasing number of adult patients are seeking orthodontic treatment to improve their dental appearance. However, special attention must be given to the periodontal status of the adults as periodontal disease and its sequel, such as pathologic migration of anterior teeth, result in esthetic and functional problems. In such adult patients, an interdisciplinary approach often offers the best option for achieving a predictable outcome to solve complex clinical problems. Materials and Methods: A prospective study was carried out on 20 adult patients [mean age = 33.3 ± 4.52 (SD), 11 females and nine males] with periodontally compromised and malaligned dentition. Loe and Silness Gingival Index (GI), Ramfjord's Periodontal Disease Index (PDI) and Dental Aesthetic Index (DAI) were recorded at the start and after completion of treatment. Results: Comparison of GI, PDI and DAI before and after completion of treatment showed statistically significant differences, indicating the relevance of combined orthodontic–periodontic treatment in periodontally compromised dentition (P < 0.01). Conclusion: The outcome of the study showed that an interdisciplinary approach is a simple solution for complex clinical problems arising as a sequel to periodontitis, such as pathological tooth migration, restoring function, esthetics and periodontal health. PMID:24872629

  19. 7 CFR 3.19 - Standards for the compromise of claims.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Standards for the compromise of claims. 3.19 Section 3.19 Agriculture Office of the Secretary of Agriculture DEBT MANAGEMENT Standards for the Administrative Collection and Compromise of Claims § 3.19 Standards for the compromise of claims. An agency shall...

  20. Perceived Career Compromise, Affect and Work-Related Satisfaction in College Students

    ERIC Educational Resources Information Center

    Tsaousides, Theodore; Jome, LaRae

    2008-01-01

    The objective of this study was to investigate the effects of career compromise on positive affect (PA), negative affect (NA), and work-related satisfaction (WRS). Career compromise refers to the modification of occupational preferences under pressing external circumstances [Gottfredson, L. S. (1981). Circumscription and compromise: A…

  1. Compromises along the Way: Balancing Speed To Market with Sustainability while Delivering Knowledge Management Services.

    ERIC Educational Resources Information Center

    Heyman, Martha K.

    This paper will discuss some of the compromises, and the path to those compromises, that must be made while implementing a successful knowledge management program within a for-profit enterprise. Specifically the following compromises are addressed: (1) manage knowledge where it is created, but do that within a global system; (2) no single scope…

  2. 38 CFR 1.903 - Settlement, waiver, or compromise under other statutory or regulatory authority.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... compromise under other statutory or regulatory authority. 1.903 Section 1.903 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS GENERAL PROVISIONS Standards for Collection, Compromise, Suspension... Settlement, waiver, or compromise under other statutory or regulatory authority. Nothing in §§ 1.900...

  3. Perceived Career Compromise, Affect and Work-Related Satisfaction in College Students

    ERIC Educational Resources Information Center

    Tsaousides, Theodore; Jome, LaRae

    2008-01-01

    The objective of this study was to investigate the effects of career compromise on positive affect (PA), negative affect (NA), and work-related satisfaction (WRS). Career compromise refers to the modification of occupational preferences under pressing external circumstances [Gottfredson, L. S. (1981). Circumscription and compromise: A…

  4. 46 CFR 502.604 - Compromise of penalties: Relation to assessment proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 9 2011-10-01 2011-10-01 false Compromise of penalties: Relation to assessment... PROVISIONS RULES OF PRACTICE AND PROCEDURE Compromise, Assessment, Mitigation, Settlement, and Collection of Civil Penalties § 502.604 Compromise of penalties: Relation to assessment proceedings. (a) Scope. Except...

  5. 32 CFR 842.124 - Waiver and compromise of United States interest.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... damages. (c) A compromise can be made upon written request from the injured party or the injured party's... CLAIMS AND LITIGATION ADMINISTRATIVE CLAIMS Hospital Recovery Claims (42 U.S.C. 2651-2653) § 842.124 Waiver and compromise of United States interest. Waivers and compromises of government claims can be...

  6. Glutathione synthesis is compromised in erythrocytes from individuals with HIV

    PubMed Central

    Morris, Devin; Ly, Judy; Chi, Po-Ting; Daliva, John; Nguyen, Truongson; Soofer, Charleen; Chen, Yung C.; Lagman, Minette; Venketaraman, Vishwanath

    2014-01-01

    We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals’ is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients’ indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells. PMID:24782776

  7. Glutathione synthesis is compromised in erythrocytes from individuals with HIV.

    PubMed

    Morris, Devin; Ly, Judy; Chi, Po-Ting; Daliva, John; Nguyen, Truongson; Soofer, Charleen; Chen, Yung C; Lagman, Minette; Venketaraman, Vishwanath

    2014-01-01

    We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals' is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients' indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells.

  8. Neglecting legumes has compromised human health and sustainable food production.

    PubMed

    Foyer, Christine H; Lam, Hon-Ming; Nguyen, Henry T; Siddique, Kadambot H M; Varshney, Rajeev K; Colmer, Timothy D; Cowling, Wallace; Bramley, Helen; Mori, Trevor A; Hodgson, Jonathan M; Cooper, James W; Miller, Anthony J; Kunert, Karl; Vorster, Juan; Cullis, Christopher; Ozga, Jocelyn A; Wahlqvist, Mark L; Liang, Yan; Shou, Huixia; Shi, Kai; Yu, Jingquan; Fodor, Nandor; Kaiser, Brent N; Wong, Fuk-Ling; Valliyodan, Babu; Considine, Michael J

    2016-08-02

    The United Nations declared 2016 as the International Year of Pulses (grain legumes) under the banner 'nutritious seeds for a sustainable future'. A second green revolution is required to ensure food and nutritional security in the face of global climate change. Grain legumes provide an unparalleled solution to this problem because of their inherent capacity for symbiotic atmospheric nitrogen fixation, which provides economically sustainable advantages for farming. In addition, a legume-rich diet has health benefits for humans and livestock alike. However, grain legumes form only a minor part of most current human diets, and legume crops are greatly under-used. Food security and soil fertility could be significantly improved by greater grain legume usage and increased improvement of a range of grain legumes. The current lack of coordinated focus on grain legumes has compromised human health, nutritional security and sustainable food production.

  9. Pneumocystis carinii, Toxoplasma gondii, Cytomegalovirus and the Compromised Host

    PubMed Central

    Ryning, Frank W.; Mills, John

    1979-01-01

    Pneumocystis carinii and Toxoplasma gondii are the two major parasitic protozoan pathogens in the immunocompromised host. Both organisms cause latent infection in humans and many animals. Cats are the definitive hosts for toxoplasmosis; the animal vector for pneumocystis (if any) has not been defined. Toxoplasma is an obligate intracellular parasite, whereas the available evidence suggests that Pneumocystis carinii exists primarily extracellularly. In compromised hosts, pneumocystis infection usually involves only lungs, whereas toxoplasma causes a generalized infection with encephalitis being the principal clinical manifestation. Both types of infection are treated with combinations of folate antagonists (trimethoprim or pyrimethamine with sulfonamide). Both parasites are associated with cytomegalovirus infection in immunosuppressed hosts, an association which may be due to symbiosis between parasites, or to an additive immunosuppressive effect of dual infection on the hosts. ImagesFigure 1.Figure 3.Figure 4.Figure 7.Figure 8.Figure 9. PMID:217182

  10. [Amputation or reconstruction of a circulatory compromised severely injured extremity?].

    PubMed

    Høiness, P; Røise, O

    1999-11-20

    18 patients treated with primary or secondary amputations after severe lower limb open fractures were studied. All limbs had clinical signs of a compromised circulation at the primary evaluation. The various injuries are described and discussed with respect to the general guidelines for primary amputation. The Mangled Extremity Severity Score (MESS) and Nerve, Ischemia, Soft tissues, Skeletal, Shock, Age (NISSSA) scores were calculated. In view of the described injuries, primary amputation was indicated in ten patients according to the general recommendations, 11 patients according to NISSSA and 15 patients according to MESS. Delayed amputation leads t a significantly (p = 0.005) higher number of operative procedures than early amputation (9.2 vs. 2.9 treatments). The decision of whether to amputate or not should be based on sound clinical judgement, but injury scores such as MESS and NISSSA may be helpful.

  11. Glycan Side Reaction May Compromise ETD-Based Glycopeptide Identification

    NASA Astrophysics Data System (ADS)

    Darula, Zsuzsanna; Medzihradszky, Katalin F.

    2014-06-01

    Tris(hydroxymethyl)aminomethane (Tris) is one of the most frequently used buffer ingredients. Among other things, it is recommended and is usually used for lectin-based affinity enrichment of glycopeptides. Here we report that sialic acid, a common `capping' unit in both N- and O-linked glycans may react with this chemical, and this side reaction may compromise glycopeptide identification when ETD spectra are the only MS/MS data used in the database search. We show that the modification may alter N- as well as O-linked glycans, the Tris-derivative is still prone to fragmentation both in `beam-type' CID (HCD) and ETD experiments, at the same time—since the acidic carboxyl group was `neutralized'—it will display a different retention time than its unmodified counterpart. We also suggest solutions that—when incorporated into existing search engines—may significantly improve the reliability of glycopeptide assignments.

  12. Thiamine absorption is not compromised in folate-deficient rats

    SciTech Connect

    Walzem, R.L.; Clifford, A.J.

    1988-11-01

    Thiamine absorption and excretion were assessed in rats with severe folate deficiency (FD) by determining the fate of oral TH-labeled and intravenous UC-labeled thiamine over a 6-h test period. Thiamine status was evaluated in these same rats by measuring transketolase activity levels of blood before (TKA) and after (TPPE) addition of thiamine pyrophosphate to the incubation mixture of the assay procedure. Two additional experiments assessed active transport of thiamine and the effect of dietary succinylsulfathiazole (SST) on TKA and TPPE in rats with moderate FD. Intestinal absorption in general and thiamine absorption in particular and thiamine status were unaltered in rats with severe FD. Inanition associated with severe FD may impair thiamine status. Thiamine absorption by active transport was not compromised in FD, and dietary succinylsulfathiazole did not affect thiamine status.

  13. Food irradiation: Special solutions for the immuno-compromised

    NASA Astrophysics Data System (ADS)

    Mohácsi-Farkas, Csilla

    2016-12-01

    Safety of food is particularly important for immuno-compromised patients, because these people are vulnerable to all sorts of infectious complications and foodborne pathogens as well, and even organisms normally considered non-pathogenic may cause problems. According to the guidelines published by the FDA, immunocompromised patients have to avoid high-risk foods, and advised to consume only pasteurized juice, milk or cheese, and well-cooked eggs, poultry, meat and fish. In the frame of an IAEA CRP the objective was to develop, in collaborations with the healthcare community, the use of irradiation to increase the variety, availability and acceptability of foods for immunocompromised, for example irradiated fresh produce (fruits, vegetables, salads) and ready-to-eat meals. Further aim was to widen the acceptance of irradiated foods by the healthcare and regulatory communities.

  14. Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

    PubMed Central

    Cologne, John; Grant, Eric J.; Nakashima, Eiji; Chen, Yun; Funamoto, Sachiyo; Katayama, Hiroaki

    2012-01-01

    Objective. Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying) the data, but overmasking can compromise utility (analysis potential). Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods. We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results. Masking by modest rounding did not adequately enhance security but rounding to remove several digits of relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions. When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs. PMID:22505949

  15. Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

    DOE PAGES

    Cologne, John; Grant, Eric J.; Nakashima, Eiji; ...

    2012-01-01

    Objective . Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying) the data, but overmasking can compromise utility (analysis potential). Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods . We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results . Masking by modest rounding did not adequately enhance security but rounding to remove several digits ofmore » relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions . When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs.« less

  16. A compromised liver alters polychlorinated biphenyl-mediated toxicity.

    PubMed

    Wahlang, Banrida; Perkins, Jordan T; Petriello, Michael C; Hoffman, Jessie B; Stromberg, Arnold J; Hennig, Bernhard

    2017-02-02

    Exposure to environmental toxicants namely polychlorinated biphenyls (PCBs) is correlated with multiple health disorders including liver and cardiovascular diseases. The liver is important for both xenobiotic and endobiotic metabolism. However, the responses of an injured liver to subsequent environmental insults has not been investigated. The current study aims to evaluate the role of a compromised liver in PCB-induced toxicity and define the implications on overall body homeostasis. Male C57Bl/6 mice were fed either an amino acid control diet (CD) or a methionine-choline deficient diet (MCD) during the 12-week study. Mice were subsequently exposed to either PCB126 (4.9mg/kg) or the PCB mixture, Arcolor1260 (20mg/kg) and analyzed for inflammatory, calorimetry and metabolic parameters. Consistent with the literature, MCD diet-fed mice demonstrated steatosis, indicative of a compromised liver. Mice fed the MCD-diet and subsequently exposed to PCB126 showed observable wasting syndrome leading to mortality. PCB126 and Aroclor1260 exposure worsened hepatic fibrosis exhibited by the MCD groups. Interestingly, PCB126 but not Aroclor1260 induced steatosis and inflammation in CD-fed mice. Mice with liver injury and subsequently exposed to PCBs also manifested metabolic disturbances due to alterations in hepatic gene expression. Furthermore, PCB exposure in MCD-fed mice led to extra-hepatic toxicity such as upregulated circulating inflammatory biomarkers, implicating endothelial cell dysfunction. Taken together, these results indicate that environmental pollution can exacerbate toxicity caused by diet-induced liver injury which may be partially due to dysfunctional energy homeostasis. This is relevant to PCB-exposed human cohorts who suffer from alcohol or diet-induced fatty liver diseases.

  17. Methamphetamine compromises gap junctional communication in astrocytes and neurons.

    PubMed

    Castellano, Paul; Nwagbo, Chisom; Martinez, Luis R; Eugenin, Eliseo A

    2016-05-01

    Methamphetamine (meth) is a central nervous system (CNS) stimulant that results in psychological and physical dependency. The long-term effects of meth within the CNS include neuronal plasticity changes, blood-brain barrier compromise, inflammation, electrical dysfunction, neuronal/glial toxicity, and an increased risk to infectious diseases including HIV. Most of the reported meth effects in the CNS are related to dysregulation of chemical synapses by altering the release and uptake of neurotransmitters, especially dopamine, norepinephrine, and epinephrine. However, little is known about the effects of meth on connexin (Cx) containing channels, such as gap junctions (GJ) and hemichannels (HC). We examined the effects of meth on Cx expression, function, and its role in NeuroAIDS. We found that meth altered Cx expression and localization, decreased GJ communication between neurons and astrocytes, and induced the opening of Cx43/Cx36 HC. Furthermore, we found that these changes in GJ and HC induced by meth treatment were mediated by activation of dopamine receptors, suggesting that dysregulation of dopamine signaling induced by meth is essential for GJ and HC compromise. Meth-induced changes in GJ and HC contributed to amplified CNS toxicity by dysregulating glutamate metabolism and increasing the susceptibility of neurons and astrocytes to bystander apoptosis induced by HIV. Together, our results indicate that connexin containing channels, GJ and HC, are essential in the pathogenesis of meth and increase the sensitivity of the CNS to HIV CNS disease. Methamphetamine (meth) is an extremely addictive central nervous system stimulant. Meth reduced gap junctional (GJ) communication by inducing internalization of connexin-43 (Cx43) in astrocytes and reducing expression of Cx36 in neurons by a mechanism involving activation of dopamine receptors (see cartoon). Meth-induced changes in Cx containing channels increased extracellular levels of glutamate and resulted in higher

  18. Blood–Retinal Barrier Compromise and Endogenous Staphylococcus aureus Endophthalmitis

    PubMed Central

    Coburn, Phillip S.; Wiskur, Brandt J.; Astley, Roger A.; Callegan, Michelle C.

    2015-01-01

    Purpose To test the hypothesis that blood–retinal barrier compromise is associated with the development of endogenous Staphylococcus aureus endophthalmitis. Methods To compromise the blood–retinal barrier in vivo, streptozotocin-induced diabetes was induced in C57BL/6J mice for 1, 3, or 5 months. Diabetic and age-matched nondiabetic mice were intravenously injected with 108 colony-forming units (cfu) of S. aureus, a common cause of endogenous endophthalmitis in diabetics. After 4 days post infection, electroretinography, histology, and bacterial counts were performed. Staphylococcus aureus–induced alterations in in vitro retinal pigment epithelial (RPE) cell barrier structure and function were assessed by anti–ZO-1 immunohistochemistry, FITC-dextran conjugate diffusion, and bacterial transmigration assays. Results We observed one bilateral infection in a control, nondiabetic animal (mean = 1.54 × 103 ± 1.78 × 102 cfu/eye, 7% incidence). Among the 1-month diabetic mice, we observed culture-confirmed unilateral infections in two animals (mean = 5.54 × 102 ± 7.09 × 102 cfu/eye, 12% incidence). Among the 3-month diabetic mice, infections were observed in 11 animals, three with bilateral infections (mean = 2.67 × 102 ± 2.49 × 102 cfu/eye, 58% incidence). Among the 5-month diabetic mice, we observed infections in five animals (mean = 7.88 × 102 ± 1.08 × 103 cfu/eye, 33% incidence). In vitro, S. aureus infection reduced ZO-1 immunostaining and disrupted the barrier function of cultured RPE cells, resulting in diffusion of fluorophore-conjugated dextrans and transmigration of live bacteria across a permeabilized RPE barrier. Conclusions Taken together, these results indicated that S. aureus is capable of inducing blood–retinal barrier permeability and causing endogenous bacterial endophthalmitis in normal and diabetic animals. PMID:26559476

  19. Treatment of Lung Cancer in Medically Compromised Patients.

    PubMed

    Crawford, Jeffrey; Wheatley-Price, Paul; Feliciano, Josephine Louella

    2016-01-01

    Outcomes for patients with lung cancer have been improved substantially through the integration of surgery, radiation, and systemic therapy for patients with early-stage disease. Meanwhile, advances in our understanding of molecular mechanisms have substantially advanced our treatment of patients with advanced lung cancer through the introduction of targeted therapies, immune approaches, improvements in chemotherapy, and better supportive care. However, the majority of these advances have occurred among patients with good functional status, normal organ function, and with the social and economic support systems to be able to benefit most from these treatments. The aim of this article is to bring greater attention to management of lung cancer in patients who are medically compromised, which remains a major barrier to care delivery. Impaired performance status is associated with poor outcomes and correlates with the high prevalence of cachexia among patients with advanced lung cancer. CT imaging is emerging as a research tool to quantify muscle loss in patients with cancer, and new therapeutics are on the horizon that may provide important adjunctive therapy in the future. The benefits of cancer therapy for patients with organ failure are poorly understood because of their exclusion from clinical trials. The availability of targeted therapy and immunotherapy may provide alternatives that may be easier to deliver in this population, but clinical trials of these new agents in this population are vital. Patients with lower socioeconomic status are disproportionately affected by lung cancer because of higher rates of tobacco addiction and the impact of socioeconomic status on delay in diagnosis, treatment, and outcomes. For all patients who are medically compromised with lung cancer, multidisciplinary approaches are particularly needed to evaluate these patients and to incorporate rapidly changing therapeutics to improve outcomes.

  20. Cerebral autoregulation is compromised during simulated fluctuations in gravitational stress.

    PubMed

    Brown, Clive M; Dütsch, Matthias; Ohring, Susanne; Neundörfer, Bernhard; Hilz, Max J

    2004-03-01

    Gravity places considerable stress on the cardiovascular system but cerebral autoregulation usually protects the cerebral blood vessels from fluctuations in blood pressure. However, in conditions such as those encountered on board a high-performance aircraft, the gravitational stress is constantly changing and might compromise cerebral autoregulation. In this study we assessed the effect of oscillating orthostatic stress on cerebral autoregulation. Sixteen (eight male) healthy subjects [aged 27 (1) years] were exposed to steady-state lower body negative pressure (LBNP) at -15 and -40 mmHg and then to oscillating LBNP at the same pressures. The oscillatory LBNP was applied at 0.1 and 0.2 Hz. We made continuous recordings of RR-interval, blood pressure, cerebral blood flow velocity (CBFV), respiratory frequency and end-tidal CO(2). Oscillations in mean arterial pressure (MAP) and CBFV were assessed by autoregressive spectral analysis. Respiration was paced at 0.25 Hz to avoid interference from breathing. Steady-state LBNP at -40 mmHg significantly increased low-frequency (LF, 0.03-0.14 Hz) powers of MAP ( P<0.01) but not of CBFV. Oscillatory 0.1 Hz LBNP (0 to -40 mmHg) significantly increased the LF power of MAP to a similar level as steady-state LBNP but also resulted in a significant increase in the LF power of CBFV ( P<0.01). Oscillatory LBNP at 0.2 Hz induced oscillations in MAP and CBFV at 0.2 Hz. Cross-spectral analysis showed that the transfer of LBNP-induced oscillations in MAP onto the CBFV was significantly greater at 0.2 Hz than at 0.1 Hz ( P<0.01). These results show that the ability of the cerebral vessels to modulate fluctuations in blood pressure is compromised during oscillatory compared with constant gravitational stress. Furthermore, this effect seems to be more pronounced at higher frequencies of oscillatory stress.

  1. Mitigating Reptile Road Mortality: Fence Failures Compromise Ecopassage Effectiveness

    PubMed Central

    Baxter-Gilbert, James H.; Riley, Julia L.; Lesbarrères, David; Litzgus, Jacqueline D.

    2015-01-01

    Roadways pose serious threats to animal populations. The installation of roadway mitigation measures is becoming increasingly common, yet studies that rigorously evaluate the effectiveness of these conservation tools remain rare. A highway expansion project in Ontario, Canada included exclusion fencing and ecopassages as mitigation measures designed to offset detrimental effects to one of the most imperial groups of vertebrates, reptiles. Taking a multispecies approach, we used a Before-After-Control-Impact study design to compare reptile abundance on the highway before and after mitigation at an Impact site and a Control site from 1 May to 31 August in 2012 and 2013. During this time, radio telemetry, wildlife cameras, and an automated PIT-tag reading system were used to monitor reptile movements and use of ecopassages. Additionally, a willingness to utilize experiment was conducted to quantify turtle behavioral responses to ecopassages. We found no difference in abundance of turtles on the road between the un-mitigated and mitigated highways, and an increase in the percentage of both snakes and turtles detected dead on the road post-mitigation, suggesting that the fencing was not effective. Although ecopassages were used by reptiles, the number of crossings through ecopassages was lower than road-surface crossings. Furthermore, turtle willingness to use ecopassages was lower than that reported in previous arena studies, suggesting that effectiveness of ecopassages may be compromised when alternative crossing options are available (e.g., through holes in exclusion structures). Our rigorous evaluation of reptile roadway mitigation demonstrated that when exclusion structures fail, the effectiveness of population connectivity structures is compromised. Our project emphasizes the need to design mitigation measures with the biology and behavior of the target species in mind, to implement mitigation designs in a rigorous fashion, and quantitatively evaluate road

  2. Stepwise chilling: tender pork without compromising water-holding capacity.

    PubMed

    Rosenvold, K; Borup, U; Therkildsen, M

    2010-05-01

    The current pork slaughter process is primarily optimized to reduce cooler shrink and the incidence of PSE pork. Elimination of the halothane gene and improved preslaughter handling have decreased the incidence of PSE pork and improved the water-holding capacity of the muscle; however, the chilling process has not been optimized to accommodate these changes. The hypothesis that stepwise chilling could improve tenderness without compromising water-holding capacity was tested in this study. The stepwise chilling treatments were composed of a rapid chilling to 10 or 15 degrees C (in a chilling tunnel) and a 6-h holding period at 10 or 15 degrees C, followed by rapid chilling to 4 degrees C. Both treatments were compared directly with a chilling treatment that simulated conventional tunnel chilling; one carcass half from each pig was allocated to a stepwise chilling treatment, whereas the other carcass half was allocated to the control treatment. A total of 42 pigs were slaughtered on 6 slaughter days. Biopsies were collected for analysis of glycogen degradation and glycogen debranching enzyme activity from slaughter until 72 h postmortem, and samples for color, sarcomere length, drip loss, Warner-Bratzler shear force, and sensory analysis were removed from the carcass 24 h postmortem. Substantial temperature differences were obtained during the holding period between the stepwise and conventionally chilled carcass halves. These had almost, but not completely, disappeared by 22 h postmortem, and although the differences were small, pH was significantly (P < 0.01) less in the stepwise-chilled carcasses compared with the control carcasses. The stepwise chilling treatments led to significantly improved (P < 0.01) tenderness in LM without compromising quality indicators or attributes such as pH, drip loss, or ham processing yield, although color of the stepwise-chilled pork was affected. Neither the tenderness of processed semimembranosus muscle nor the shear force of

  3. Predicting early nonelective hospital readmission in nutritionally compromised older adults.

    PubMed

    Friedmann, J M; Jensen, G L; Smiciklas-Wright, H; McCamish, M A

    1997-06-01

    This study determined predictors of early nonelective hospital readmission in 92 (49 women and 43 men) nutritionally compromised Medicare patients. Subjects ranged in age from 65 to 92 y and represented patients hospitalized previously for medical or surgical services. The study used a repeated-measures design of multiple variables representing demographics, anthropometric and clinical values, and functional status. Data were collected during hospitalization and during home visits at 1 and 3 mo postdischarge. There were 26 readmissions, making the 4-mo nonelective readmission rate 26%. Subjects who were readmitted nonelectively were compared with those not readmitted. Univariate analyses suggested strong relations between readmission outcome and serum albumin, total lymphocyte count, change in weight, and change in white blood cell count. Sociodemographic variables were less useful in predicting readmission than were measurements of patients' clinical status. Measurements of change in clinical variables were generally more predictive of readmission than was any one single measurement. Multivariate-logistic-regression analyses suggested a model consisting of change in weight and change in serum albumin from hospitalization to 1 mo after discharge as being highly predictive of early nonelective readmission. Individuals with any amount of weight loss and no improvement in albumin concentrations during the first month after hospitalization were at a much higher risk of readmission than were those who maintained or increased their postdischarge weight and had repleted their serum albumin concentrations. More study is warranted to clarify whether routine monitoring of changes in weight and serum albumin after hospitalization is appropriate in older adults.

  4. Oviposition site selection in Cactoblastis cactorum (Lepidoptera): constraints and compromises.

    PubMed

    Robertson, H G

    1987-10-01

    Oviposition by Cactoblastis cactorum on Opuntia ficus-indica and O. aurantiaca was assessed from the positioning of egg sticks on plants in the field. The number of egg sticks laid on O. ficus-indica plants was affected by: (1) plant size; (2) moth emergence near the plant; (3) cladode condition; and (4) plant conspicuousness. These factors contributed towards the clumping of egg sticks on plants. There was no apparent oviposition preference for one of the two host plant species despite the fact that egg predation was higher and fecundity lower on O. aurantiaca. The selection of a site for oviposition on the host plants was influenced by: (1) cladode condition; (2) height above ground; and (3) shelter from wind during oviposition. Succulent cladodes were the favoured sites for oviposition. The evidence suggests that in C. cactorum, oviposition site selection is largely the net result of a compromise between oviposition behaviour selected for increasing the probability of juvenile survival and oviposition behaviour selected for increasing the probability of laying the full complement of eggs. In addition, environmental and physiological factors such as wind and wing-loading, are thought to place constraints on the range of sites available for oviposition.

  5. Identification of medically compromised dental patients in a Portuguese population.

    PubMed

    Esteves, Helder José; Quintanilla, José Maria

    2013-01-01

    The age of the patients, the presence of one or more chronic disorders and the patients' drug regimens can influence dental treatment and oral health. This is a prospective, descriptive study to identify subjects with compromised health who received dental treatment between November 2010 and June 2011 at private dental practices run by graduates of the Portuguese Catholic University. Application software in Microsoft Excel was developed containing the questionnaire, based on the EMRRH (European medical risk related history), which allowed the collection of data from 1603 adult patients. Microsoft Excel, G*Power and SPSS V.18 were used for statistical treatment. The five most frequent medical conditions found were: 1) hypertension, 21.0%; 2) arrhythmias, 11.2%; 3) Angina pectoris, 8.3%; 4) allergies, 77%; 5) thyroid disease, 6.2%. The medications taken related to these were: a) antihypertensives, 11.0%; b) antidepressants, anxiolytics and hypnotics, 10.6%; c) acetylsalicylic acid, 4.2%; d) antiarrhythmic and sympathomimetic drugs, 4.1%; e) haemostatic treatment, 3.6%. 42.7% of the patients had no medical risks, 32.9% were classified as ASA II, 11.7% as ASA III and 12.7% as ASA IV. This study emphasises the importance of often-neglected anamnesis in oral care. The high prevalence of patients with medical conditions should be continuously studied to verify the changes over time and should be expanded to other regions and countries.

  6. Tert-butylhydroquinone compromises survival in murine experimental stroke.

    PubMed

    Sun, Jiahong; Hu, Heng; Ren, Xuefang; Simpkins, James W

    2016-01-01

    Tert-butylhydroquinone (tBHQ), an Nrf2 signaling pathway inducer that is widely used as a food additive in the U.S., prevents oxidative stress-induced cytotoxicity in neurons. This study assesses the effects of tBHQ on ischemic stroke outcomes in mice. We measured infarct size, neurological deficits, and brain volume after tBHQ treatments in murine permanent middle cerebral artery occlusion (pMCAO) model in vivo. Further, we evaluated the regulation of tBHQ on mitochondrial function in cerebrovascular endothelial cells in vitro, which is critical to the blood-brain barrier (BBB) permeability. Our results demonstrated that tBHQ increased post-stroke mortality and worsened stroke outcomes. Mitochondrial function was suppressed by tBHQ treatment of cerebrovascular endothelial cells, and this suppression was potentiated by co-treatment with lipopolysaccharide (LPS), the bacterial mimic. These data indicate that tBHQ-exacerbated stroke damage might due to the compromised BBB permeability in permanent stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Silicone rubber contact lenses for the compromised cornea.

    PubMed

    Bacon, A S; Astin, C; Dart, J K

    1994-09-01

    Silicone rubber contact lenses (SRCLs) are infrequently used because of the risk of developing unpredictable lens tightening, their poor availability, and their expense. However, their high oxygen transmissibility and nonabsorption of water make them valuable as therapeutic lenses. SRCLs are routinely used in our management of severely dry eyes, decompensated or vascularised corneas, and conditions where the corneal shape is flat or irregular. The records of 48 consecutive patients fitted with SRCLs between January 1989 and June 1990 were studied. The clinical history, indications, complications, success, and duration of SRCL wear were analysed. Therapeutic goals, which included epithelial healing, sealing of corneal perforations, and improved comfort and vision, were achieved in 53 of 62 eyes. The best corrected acuity was attained using SRCLs in 58 of 62 eyes. Failure of lens wear was due to lens tightening (four eyes), spoilation (two), discomfort, fornix shortening, handling problems, and decentration (one each). Infective keratitis complicated one case, but SRCL wear was resumed after successful treatment. With adequate follow-up, SRCLs have a low complication rate and are well tolerated even in severely compromised eyes, for which conventional lenses may be contraindicated. Their continued use as therapeutic lenses is advocated in carefully selected cases.

  8. The maintenance of energy balance is compromised after weight loss.

    PubMed

    Reed, Jennifer L; Chaput, Jean-Philippe; Tremblay, Angelo; Doucet, Éric

    2013-04-01

    Available literature reveals that of the majority of individuals who are able to lose weight, only a small number are able to maintain their weight loss over time. Effective weight maintenance strategies after weight loss are illusive, which is most likely the result of a number of yet poorly understood factors. In fact, both appetite and energy expenditure are profoundly altered in response to reductions in body energy reserves. Weight reduction leads to decreased energy needs, but to an augmented drive to eat, thus compromising the maintenance of energy balance in the weight-reduced state by widening the theoretical gap between the 2 components of energy balance. This review first provides a summary of the factors related to the control of feeding and energy expenditure during weight stability. More specifically related to the topic of this review, the bulk of the literature presented depicts the post weight-loss control of appetite and energy expenditure. The integration of the literature presented in this paper reveals that body weight loss seems to orchestrate a coordinated response to resist further energy depletion, that would seem to create a state of increased vulnerability of weight regain. It is argued that these changes are largely responsible for the more than apparent difficulty in maintaining weight maintenance after weight loss. Copyright © 2013 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  9. Protection characteristics of a Faraday cage compromised by lightning burnthrough.

    SciTech Connect

    Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt; Montoya, Sandra L.; Merewether, Kimball O.; Coats, Rebecca Sue; Martinez, Leonard E.; Jojola, John M.

    2012-01-01

    A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).

  10. Compromised central tolerance of ICA69 induces multiple organ autoimmunity

    PubMed Central

    Fan, Yong; Gualtierotti, Giulio; Tajima, Asako; Grupillo, Maria; Coppola, Antonina; He, Jing; Bertera, Suzanne; Owens, Gregory; Pietropaolo, Massimo; Rudert, William A.; Trucco, Massimo

    2015-01-01

    For reasons not fully understood, patients with an organ-specific autoimmune disease have increased risks of developing autoimmune responses against other organs/tissues. We identified ICA69, a known β-cell autoantigen in Type 1 diabetes, as a potential common target in multi-organ autoimmunity. NOD mice immunized with ICA69 polypeptides exhibited exacerbated inflammation not only in the islets, but also in the salivary glands. To further investigate ICA69 autoimmunity, two genetically modified mouse lines were generated to modulate thymic ICA69 expression: the heterozygous ICA69del/wt line and the thymic medullary epithelial cell-specific deletion Aire-ΔICA69 line. Suboptimal central negative selection of ICA69-reactive T-cells was observed in both lines. Aire-ΔICA69 mice spontaneously developed coincident autoimmune responses to the pancreas, the salivary glands, the thyroid, and the stomach. Our findings establish a direct link between compromised thymic ICA69 expression and autoimmunity against multiple ICA69-expressing organs, and identify a potential novel mechanism for the development of multi-organ autoimmune diseases. PMID:25088457

  11. Compromised Rat Testicular Antioxidant Defence System by Hypothyroidism before Puberty.

    PubMed

    Sahoo, Dipak K; Roy, Anita

    2012-01-01

    Altered thyroid function during early stages of development is known to affect adversely testicular growth, physiology, and antioxidant defence status at adulthood. The objective of the present study is to investigate the modulation of antioxidant defence status in neonatal persistent hypothyroid rats before their sexual maturation and also to identify the specific testicular cell populations vulnerable to degeneration during neonatal hypothyroidism in immature rats. Hypothyroidism was induced in neonates by feeding the lactating mother with 0.05% 6-n-propyl-2-thiouracil (PTU) through the drinking water. From the day of parturition till weaning (25 day postpartum), the pups received PTU through mother's milk (or) drinking water and then directly from drinking water containing PTU for the remaining period of experimentation. On the 31st day postpartum, the animals were sacrificed for the study. An altered antioxidant defence system marked by elevated SOD, CAT, and GR activities, with decreased GPx and GST activities were observed along with increased protein carbonylation, disturbed redox status in hypothyroid immature rat testis. This compromised testicular antioxidant status might have contributed to poor growth and development by affecting the spermatogenesis and steroidogenesis in rats before puberty as indicated by reduced germ cell number, complete absence of round spermatids, decreased seminiferous tubule diameter, and decreased testosterone level.

  12. Metabolic Stress and Compromised Identity of Pancreatic Beta Cells

    PubMed Central

    Swisa, Avital; Glaser, Benjamin; Dor, Yuval

    2017-01-01

    Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D. PMID:28270834

  13. Physiologic assessment of fetal compromise: biomarkers of toxic exposure

    SciTech Connect

    Longo, L.D.

    1987-10-01

    Understanding the physiologic and endocrinologic basis of fetal development is a major goal of perinatal biology. During the past decade a number of technological developments have allowed more precise evaluation of the fetus in utero and diagnosis of abnormalities. Despite these methodological achievements, however, there are no specific biological markers currently available to indicate that exposure to a given xenobiotic is associated with a cellular, subcellular, or pharmacodynamic event. This paper evaluates the following issues: what are some of the unique physiologic and endocrinologic features of the fetal milieu interieur. What problems are peculiar to fetal assessment. What are some examples of validated biomarkers and their applicability. What promising biomarkers are on the horizon. How may molecular probes be of value as biological markers of fetal compromise. What are some of the major research gaps and needs, and how should research priorities be set. Some of these topics are addressed. Moreover, the more general role(s) that various diagnostic methods and biological markers can have in an understanding of the regulation of fetal growth and differentiation and the role of xenobiotics in affecting the normal course of events are discussed.

  14. Taking a Bad Turn: Compromised DNA Damage Response in Leukemia

    PubMed Central

    Nilles, Nadine; Fahrenkrog, Birthe

    2017-01-01

    Genomic integrity is of outmost importance for the survival at the cellular and the organismal level and key to human health. To ensure the integrity of their DNA, cells have evolved maintenance programs collectively known as the DNA damage response. Particularly challenging for genome integrity are DNA double-strand breaks (DSB) and defects in their repair are often associated with human disease, including leukemia. Defective DSB repair may not only be disease-causing, but further contribute to poor treatment outcome and poor prognosis in leukemia. Here, we review current insight into altered DSB repair mechanisms identified in leukemia. While DSB repair is somewhat compromised in all leukemic subtypes, certain key players of DSB repair are particularly targeted: DNA-dependent protein kinase (DNA-PK) and Ku70/80 in the non-homologous end-joining pathway, as well as Rad51 and breast cancer 1/2 (BRCA1/2), key players in homologous recombination. Defects in leukemia-related DSB repair may not only arise from dysfunctional repair components, but also indirectly from mutations in key regulators of gene expression and/or chromatin structure, such as p53, the Kirsten ras oncogene (K-RAS), and isocitrate dehydrogenase 1 and 2 (IDH1/2). A detailed understanding of the basis for defective DNA damage response (DDR) mechanisms for each leukemia subtype may allow to further develop new treatment methods to improve treatment outcome and prognosis for patients. PMID:28471392

  15. Compromise and Synergy in High-Efficiency Thermoelectric Materials.

    PubMed

    Zhu, Tiejun; Liu, Yintu; Fu, Chenguang; Heremans, Joseph P; Snyder, Jeffrey G; Zhao, Xinbing

    2017-03-06

    The past two decades have witnessed the rapid growth of thermoelectric (TE) research. Novel concepts and paradigms are described here that have emerged, targeting superior TE materials and higher TE performance. These superior aspects include band convergence, "phonon-glass electron-crystal", multiscale phonon scattering, resonant states, anharmonicity, etc. Based on these concepts, some new TE materials with distinct features have been identified, including solids with high band degeneracy, with cages in which atoms rattle, with nanostructures at various length scales, etc. In addition, the performance of classical materials has been improved remarkably. However, the figure of merit zT of most TE materials is still lower than 2.0, generally around 1.0, due to interrelated TE properties. In order to realize an "overall zT > 2.0," it is imperative that the interrelated properties are decoupled more thoroughly, or new degrees of freedom are added to the overall optimization problem. The electrical and thermal transport must be synergistically optimized. Here, a detailed discussion about the commonly adopted strategies to optimize individual TE properties is presented. Then, four main compromises between the TE properties are elaborated from the point of view of the underlying mechanisms and decoupling strategies. Finally, some representative systems of synergistic optimization are also presented, which can serve as references for other TE materials. In conclusion, some of the newest ideas for the future are discussed.

  16. Tert-butylhydroquinone Compromises Survival in Murine Experimental Stroke

    PubMed Central

    Sun, Jiahong; Hu, Heng; Ren, Xuefang; Simpkins, James W.

    2016-01-01

    tert-butylhydroquinone (tBHQ), an Nrf2 signaling pathway inducer that is widely used as a food additive in the U.S., prevents oxidative stress-induced cytotoxicity in neurons. This study assesses the effects of tBHQ on ischemic stroke outcomes in mice. We measured infarct size, neurological deficits, and brain volume after tBHQ treatments in murine permanent middle cerebral artery occlusion (pMCAO) model in vivo. Further, we evaluated the regulation of tBHQ on mitochondrial function in cerebrovascular endothelial cells in vitro, which is critical to the blood–brain barrier (BBB) permeability. Our results demonstrated that tBHQ increased post-stroke mortality and worsened stroke outcomes. Mitochondrial function was suppressed by tBHQ treatment of cerebrovascular endothelial cells, and this suppression was potentiated by co-treatment with lipopolysaccharide (LPS), the bacterial mimic. These data indicate that tBHQ-exacerbated stroke damage might due to the compromised BBB permeability in permanent stroke. PMID:26827673

  17. Identification of Campylobacter spp. and discrimination from Helicobacter and Arcobacter spp. by direct sequencing of PCR-amplified cpn60 sequences and comparison to cpnDB, a chaperonin reference sequence database.

    PubMed

    Hill, Janet E; Paccagnella, Ana; Law, Kee; Melito, Pasquale L; Woodward, David L; Price, Lawrence; Leung, Amy H; Ng, Lai-King; Hemmingsen, Sean M; Goh, Swee Han

    2006-04-01

    A robust method for the identification of Campylobacter spp. based on direct sequencing of PCR-amplified partial cpn60 sequences and comparison of these to a reference database of cpn60 sequences is reported. A total of 53 Campylobacter isolates, representing 15 species, were identified and distinguished from phenotypically similar Helicobacter and Arcobacter strains. Pairwise cpn60 sequence identities between Campylobacter spp. ranged from 71 to 92 %, with most between 71 and 79 %, making discrimination of these species obvious. The method described overcomes limitations of existing PCR-based methods, which require time-consuming and complex post-amplification steps such as the cloning of amplification products. The results of this study demonstrate the potential for use of the reference chaperonin sequence database, cpnDB, as a tool for identification of bacterial isolates based on cpn60 sequences amplified with universal primers.

  18. Raised Intensity Phonation Compromises Vocal Fold Epithelial Barrier Integrity

    PubMed Central

    Rousseau, Bernard; Suehiro, Atsushi; Echemendia, Nicholas; Sivasankar, Mahalakshmi

    2010-01-01

    Objectives/Hypothesis We investigated the hypothesis that 30 minutes of raised intensity phonation alters transcript levels of vocal fold intercellular tight junction proteins and disrupts the vocal fold epithelial barrier. Study Design Prospective animal study. Methods Eighteen New Zealand white breeder rabbits were randomly assigned to receive 30 minutes of raised intensity phonation or approximation of the vocal folds without phonation. Quantitative polymerase chain reaction (qPCR) was used to investigate transcript levels of the epithelial intercellular tight junction proteins, occludin and zonula occludin-1 (Z0-1), and the adherens junction proteins β-catenin and E-cadherin. Structural alterations to the vocal fold epithelium were further examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results Mann Whitney U revealed significantly decreased occludin (P = .016) and β-catenin (P = .016) gene expression from rabbits undergoing raised intensity phonation, compared to control. There were no significant differences in Z0-1 and E-Cadherin gene expression between groups (P >.025). SEM revealed significant obliteration, desquamation, and evidence of microhole formation in rabbit vocal folds exposed to raised intensity phonation, compared to control, while TEM revealed dilated intercellular morphology between groups. Conclusions Results provide support for the hypothesis that a transient episode of raised intensity phonation alters transcript levels of vocal fold intercellular tight junction proteins and disrupts integrity of the epithelial barrier. The loss of barrier integrity may have significant consequences on epithelial defenses and compromise protection of the underlying mucosa from damage secondary to prolonged vibration exposure. PMID:21271586

  19. Efficacy of New Adhesion Promoters on Compromised Hypocalcified Enamel.

    PubMed

    Vamsilatha, Kurapati; Venkata, Kishore Mayakuntla Sai; Aileni, Kaladhar Reddy; Sashidhar, Nagam Reddy

    2015-07-01

    The amount of technological progress occurred in the last few years has brought an add up to the benefits of bonding in Orthodontics. Research-based findings have constantly led to the development of new materials that are aimed to simplify the clinical procedures like bonding of brackets to compromised enamel surfaces. Hence, the present study is aimed to assess the bond strength of orthodontic brackets on fluorosed enamel using adhesion promoters. To evaluate the shear bond strength (SBS) of orthodontic brackets bonded on fluorosed enamel using conventional Transbond XT and new adhesion promoters such as Enhance LC and All Bond 3. The study involved 90 non carious, extracted teeth with mild to moderate fluorosis randomly divided into 3 Groups. In Group - I (control group) the teeth were bonded with conventional Transbond XT and cured with LED light. In Group - II Enhance LC was applied to fluorosed enamel before bonding and in Group - III All Bond 3 was used. Shear bond strength was tested by using Universal testing Instron machine. ANOVA and Post-Hoc Tukey's tests were used to compare shear bond strength. Adhesive remnant on the tooth was assessed and scored using adhesive remnant index (ARI). Results showed a reduced SBS values (9.43MPa ±3.03) with conventional Transbond XT on fluorosed enamel. Among the adhesion boosters used Enhance LC illustrated lesser SBS values (12.03 MPa ± 4.42) compared with All Bond 3 (14.38MPa ±4.92). ARI showed bond failure at bracket resin interface in group I & group II and at enamel resin interface in group III although statistically insignificant. It was concluded that using adhesion boosters on fluorosed enamel showed higher bond strength compared to the control group. Among the two adhesion promoters used All Bond 3 expressed highest bond strength compared to Enhance LC although statistically insignificant.

  20. Zinc reduces epithelial barrier compromise induced by human seminal plasma

    PubMed Central

    Mullin, James M.; Diguilio, Katherine M.; Valenzano, Mary C.; Deis, Rachael; Thomas, Sunil; Zurbach, E. Peter; Abdulhaqq, Shaheed; Montaner, Luis J.

    2017-01-01

    Human semen has the potential to modulate the epithelial mucosal tissues it contacts, as seminal plasma (SP) is recognized to contain both pro- and anti-barrier components, yet its effects on epithelial barrier function are largely unknown. We addressed the role of human SP when exposed to the basal-lateral epithelial surface, a situation that would occur clinically with prior mechanical or disease-related injury of the human epithelial mucosal cell layers in contact with semen. The action of SP on claudins-2, -4, -5, and -7 expression, as well as on a target epithelium whose basolateral surface has been made accessible to SP, showed upregulation of claudins-4 and -5 in CACO-2 human epithelial cell layers, despite broad variance in SP-induced modulation of transepithelial electrical resistance and mannitol permeability. Upregulation of claudin-2 by SP also exhibited such variance by SP sample. We characterize individual effects on CACO-2 barrier function of nine factors known to be present abundantly in seminal plasma (zinc, EGF, citrate, spermine, fructose, urea, TGF, histone, inflammatory cytokines) to establish that zinc, spermine and fructose had significant potential to raise CACO-2 transepithelial resistance, whereas inflammatory cytokines and EGF decreased this measure of barrier function. The role of zinc as a dominant factor in determining higher levels of transepithelial resistance and lower levels of paracellular leak were confirmed by zinc chelation and exogenous zinc addition. As expected, SP presentation to the basolateral cell surface also caused a very dramatic yet transient elevation of pErk levels. Results suggest that increased zinc content in SP can compete against the barrier-compromising effect of negative modulators in SP when SP gains access to that epithelium’s basolateral surface. Prophylactic elevation of zinc in an epithelial cell layer prior to contact by SP may help to protect an epithelial barrier from invasion by SP-containing STD

  1. Glutaric acid moderately compromises energy metabolism in rat brain.

    PubMed

    da C Ferreira, Gustavo; Viegas, Carolina M; Schuck, Patrícia F; Latini, Alexandra; Dutra-Filho, Carlos S; Wyse, Angela T S; Wannmacher, Clóvis M D; Vargas, Carmen R; Wajner, Moacir

    2005-12-01

    Glutaric acidemia type I is an inherited metabolic disorder biochemically characterized by tissue accumulation of predominantly glutaric acid (GA). Affected patients present frontotemporal hypotrophy, as well as caudate and putamen injury following acute encephalopathic crises. Considering that the underlying mechanisms of basal ganglia damage in this disorder are poorly known, in the present study we tested the effects of glutaric acid (0.2-5mM) on critical enzyme activities of energy metabolism, namely the respiratory chain complexes I-IV, succinate dehydrogenase and creatine kinase in midbrain of developing rats. Glutaric acid significantly inhibited creatine kinase activity (up to 26%) even at the lowest dose used in the assays (0.2mM). We also observed that CK inhibition was prevented by pre-incubation of the homogenates with reduced glutathione, suggesting that the inhibitory effect of GA was possibly mediated by oxidation of essential thiol groups of the enzyme. In addition, the activities of the respiratory chain complex I-III and of succinate dehydrogenase were also significantly inhibited by 20 and 30%, respectively, at the highest glutaric acid concentration tested (5mM). In contrast, complexes II-III and IV activities of the electron transport chain were not affected by the acid. The effect of glutaric acid on the rate of oxygen consumption in intact mitochondria from the rat cerebrum was also investigated. Glutaric acid (1mM) significantly lowered the respiratory control ratio (state III/state IV) up to 40% in the presence of the respiratory substrates glutamate/malate or succinate. Moreover, state IV respiration linked to NAD and FAD substrates was significantly increased in GA-treated mitochondria while state III was significantly diminished. The results indicate that the major metabolite accumulating in glutaric acidemia type I moderately compromises brain energy metabolism in vitro.

  2. Experimental nonalcoholic steatohepatitis compromises ureagenesis, an essential hepatic metabolic function.

    PubMed

    Thomsen, Karen Louise; Grønbæk, Henning; Glavind, Emilie; Hebbard, Lionel; Jessen, Niels; Clouston, Andrew; George, Jacob; Vilstrup, Hendrik

    2014-08-01

    Nonalcoholic steatohepatitis (NASH) is increasing in prevalence, yet its consequences for liver function are unknown. We studied ureagenesis, an essential metabolic liver function of importance for whole body nitrogen homeostasis, in a rodent model of diet-induced NASH. Rats were fed a high-fat, high-cholesterol diet for 4 and 16 wk, resulting in early and advanced experimental NASH, respectively. We examined the urea cycle enzyme mRNAs in liver tissue, the hepatocyte urea cycle enzyme proteins, and the in vivo capacity of urea-nitrogen synthesis (CUNS). Early NASH decreased all of the urea cycle mRNAs to an average of 60% and the ornithine transcarbamylase protein to 10%, whereas the CUNS remained unchanged. Advanced NASH further decreased the carbamoyl phosphate synthetase protein to 63% and, in addition, decreased the CUNS by 20% [from 5.65 ± 0.23 to 4.58 ± 0.30 μmol × (min × 100 g)(-1); P = 0.01]. Early NASH compromised the genes and enzyme proteins involved in ureagenesis, whereas advanced NASH resulted in a functional reduction in the capacity for ureagenesis. The pattern of urea cycle perturbations suggests a prevailing mitochondrial impairment by NASH. The decrease in CUNS has consequences for the ability of the body to adjust to changes in the requirements for nitrogen homeostasis e.g., at stressful events. NASH, thus, in terms of metabolic consequences, is not an innocuous lesion, and the manifestations of the damage seem to be a continuum with increasing disease severity.

  3. Photofunctionalized dental implants: a case series in compromised bone.

    PubMed

    Funato, Akiyoshi; Ogawa, Takahiro

    2013-01-01

    Ultraviolet (UV) light treatment of titanium, or photofunctionalization, has been shown to enhance its osteoconductivity in animal and in vitro studies, but its clinical performance has yet to be reported. This clinical case series sought to examine the effect of photofunctionalization on implant success, healing time, osseointegration speed, and peri-implant marginal bone level changes at 1 year after restoration. Four partially edentulous patients were included in the study. Seven implants with identical microroughened surfaces were photofunctionalized with UV light for 15 minutes. Osseointegration speed was calculated by measuring the increase in implant stability quotient (ISQ) per month. Marginal bone levels were evaluated radiographically at crown placement and at 1 year. All implants placed into fresh extraction sockets, vertically augmented bone, simultaneously augmented sinuses, or the site of a failing implant remained functional and healthy at 1 year, even with an earlier loading protocol (2.1 to 4.5 months). ISQs of 48 to 75 at implant placement had increased to 68 to 81 at loading. In particular, implants with low primary stability (initial ISQ < 70) showed large increases in ISQ. The speed of osseointegration of photofunctionalized implants was considerably greater than that of as-received implants documented in the literature. Mean marginal bone levels were -0.35 ± 0.71 mm at crown placement and had significantly increased to 0.16 ± 0.53 mm at 1 year, with coronal gains in marginal bone level that surpassed the implant platform. No implants showed marginal bone loss. Within the limits of this study, photofunctionalization expedited and enhanced osseointegration of commercial dental implants in various clinically challenging/compromised bone conditions. Photofunctionalization resulted in preservation--and often a gain--of marginal bone level, and long-term large-scale clinical validation is warranted.

  4. Metabolic analysis of mouse brains that have compromised iron storage.

    PubMed

    Ill, Amanda M; Mitchell, Todd R; Neely, Elizabeth B; Connor, James R

    2006-09-01

    Iron is a critical component of the CNS that must be tightly regulated; too little iron can result in energy insufficiency and too much iron can result in oxidative stress. The intracellular iron storage protein ferritin is central to the regulation of iron. In this study, we determined the neurochemical profile of brains of animals deficient in heavy-chain ferritin (H-ferritin) using high-resolution magic angle spin proton magnetic resonance spectroscopy (HR-MAS (1)H MRS). Spectra of 2 mm-thick coronal tissue punches ( approximately 4 mg) were obtained using a CPMG pulse sequence on Bruker Avance 500 and quantified (nmol/mg tissue) using customized LCModel software (16 metabolites). In H-ferritin deficient mice, we found significant increases in striatal glutamate, hippocampal choline, and N-acetyl-aspartyl-glutamate in both the cortex and the hippocampus (t-test, p < 0.05). Neurochemical profiling with principal component analysis (PCA) revealed increased glutamate in the hippocampus, striatum, and ventral tegmental area (VTA) in H-ferritin deficient animals as compared to wild-type. While lactate was increased in the VTA of deficient animals, it was decreased in the striatum. Also, GABA was increased in both cortical and striatal regions of deficient mice. These changes reveal the importance of proper iron management for maintaining neurochemical balance and provide new evidence for region specific differences in neurochemical profiles as a result of compromised ability of neurons to store iron while overall iron status is normal. Because H-ferritin is predominantly expressed in neurons, the neurochemical profile is suggestive of neuronal iron deficiency and may have relevance to the functional consequences associated with brain iron deficiency.

  5. The muscle-mechanical compromise framework: Implications for the scaling of gait and posture

    PubMed Central

    Usherwood, James Richard (Jim)

    2016-01-01

    Abstract Many aspects of animal and human gait and posture cannot be predicted from purely mechanical work minimization or entirely based on optimizing muscle efficiency. Here, the Muscle-Mechanical Compromise Framework is introduced as a conceptual paradigm for considering the interactions and compromises between these two objectives. Current assumptions in implementing the Framework are presented. Implications of the compromise are discussed and related to the scaling of running mechanics and animal posture. PMID:28149398

  6. Child mental health consultation with families of medically compromised infants.

    PubMed

    Mayes, Linda C

    2003-07-01

    behavioral and psychological interventions are integrated with the child's biomedical care. 5. Fostering a brief, or sometimes long-term, therapeutic relationship with the family or facilitating the family's finding such a relationship with another clinician. There will never be enough child and adolescent psychiatrists and psychologists to treat all families of medically compromised infants. Knowledge of normative responses has advanced to the point at which basic skills can be used by and transmitted to others who can provide basic services. There is much to be learned about the short- and long-term sequelae of such stressful situations on individuals and family systems with preexisting psychopathology. For such families, child mental health professionals are uniquely suited to play a further role in research and treatment.

  7. Near-infrared spectroscopy for detection of vascular compromise in paediatric supracondylar fractures.

    PubMed

    Skowno, Justin J; Quick, Tom J; Carpenter, Eleanor C; De Lima, Jonathan; Gibbons, Paul J; Little, David G

    2014-03-01

    Children suffering supracondylar fractures of the humerus are at risk of vascular compromise, which is currently assessed clinically, although other modalities such as angiography, pulse oximetry, Doppler ultrasound and magnetic resonance angiography have been used. We sought to ascertain whether tissue haemoglobin oxygenation (StO2) measurement could distinguish between patients with and without clinical vascular compromise following supracondylar fractures of the humerus. We prospectively observed StO2 using near-infrared spectroscopy in 29 paediatric patients with supracondylar fractures requiring operative manipulation. The injured and uninjured volar forearm compartments were monitored immediately before and after fracture reduction. The relationship between StO2 in the injured and uninjured limb, and the presence of pre-operative vascular compromise was assessed. Seven out of 29 children presented with vascular compromise. Patients with clinical vascular compromise had significantly lower pre-reduction StO2 (63.5% ± 15%, mean ± standard deviation), compared to those without compromise (80.9% ± 10%). StO2 normalized following surgery in all children with vascular compromise. These improvements in muscle StO2 were associated, in all patients, with the clinical return of pulses and resolution of neurological symptoms if present. StO2 monitoring can identify patients with clinical vascular compromise, can identify the return of adequate perfusion following operative correction of supracondylar fractures, and may be a useful adjunct to clinical assessment.

  8. 32 CFR 2001.48 - Loss, possible compromise or unauthorized disclosure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Loss, possible compromise or unauthorized disclosure. 2001.48 Section 2001.48 National Defense Other Regulations Relating to National Defense... SECURITY INFORMATION Safeguarding § 2001.48 Loss, possible compromise or unauthorized disclosure....

  9. 32 CFR 2001.48 - Loss, possible compromise or unauthorized disclosure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Loss, possible compromise or unauthorized disclosure. 2001.48 Section 2001.48 National Defense Other Regulations Relating to National Defense... SECURITY INFORMATION Safeguarding § 2001.48 Loss, possible compromise or unauthorized disclosure....

  10. 32 CFR 2001.48 - Loss, possible compromise or unauthorized disclosure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Loss, possible compromise or unauthorized disclosure. 2001.48 Section 2001.48 National Defense Other Regulations Relating to National Defense... SECURITY INFORMATION Safeguarding § 2001.48 Loss, possible compromise or unauthorized disclosure....

  11. 22 CFR 304.7 - Authority to adjust, determine, compromise, and settle claims.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Authority to adjust, determine, compromise, and settle claims. 304.7 Section 304.7 Foreign Relations PEACE CORPS CLAIMS AGAINST GOVERNMENT UNDER FEDERAL... the Peace Corps retains authority to consider, ascertain, adjust, determine, compromise and settle...

  12. 22 CFR 304.7 - Authority to adjust, determine, compromise, and settle claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Authority to adjust, determine, compromise, and settle claims. 304.7 Section 304.7 Foreign Relations PEACE CORPS CLAIMS AGAINST GOVERNMENT UNDER FEDERAL... the Peace Corps retains authority to consider, ascertain, adjust, determine, compromise and settle...

  13. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... INFORMATION TECHNOLOGY Security and Privacy for Computer Systems 239.7102-2 Compromising emanations—TEMPEST or... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Compromising emanations-TEMPEST or other standard. 239.7102-2 Section 239.7102-2 Federal Acquisition Regulations System DEFENSE...

  14. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... INFORMATION TECHNOLOGY Security and Privacy for Computer Systems 239.7102-2 Compromising emanations—TEMPEST or... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Compromising emanations-TEMPEST or other standard. 239.7102-2 Section 239.7102-2 Federal Acquisition Regulations System DEFENSE...

  15. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... INFORMATION TECHNOLOGY Security and Privacy for Computer Systems 239.7102-2 Compromising emanations—TEMPEST or... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Compromising emanations-TEMPEST or other standard. 239.7102-2 Section 239.7102-2 Federal Acquisition Regulations System DEFENSE...

  16. 20 CFR 340.14 - Factors due to be considered in a compromise.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Factors due to be considered in a compromise. 340.14 Section 340.14 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT RECOVERY OF BENEFITS § 340.14 Factors due to be considered in a compromise....

  17. 22 CFR 304.7 - Authority to adjust, determine, compromise, and settle claims.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Authority to adjust, determine, compromise, and settle claims. 304.7 Section 304.7 Foreign Relations PEACE CORPS CLAIMS AGAINST GOVERNMENT UNDER FEDERAL TORT CLAIMS ACT Procedures § 304.7 Authority to adjust, determine, compromise, and settle claims. The...

  18. 22 CFR 304.7 - Authority to adjust, determine, compromise, and settle claims.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Authority to adjust, determine, compromise, and settle claims. 304.7 Section 304.7 Foreign Relations PEACE CORPS CLAIMS AGAINST GOVERNMENT UNDER FEDERAL TORT CLAIMS ACT Procedures § 304.7 Authority to adjust, determine, compromise, and settle claims. The...

  19. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... INFORMATION TECHNOLOGY Security and Privacy for Computer Systems 239.7102-2 Compromising emanations—TEMPEST or... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Compromising emanations-TEMPEST or other standard. 239.7102-2 Section 239.7102-2 Federal Acquisition Regulations System...

  20. 22 CFR 304.7 - Authority to adjust, determine, compromise, and settle claims.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Authority to adjust, determine, compromise, and settle claims. 304.7 Section 304.7 Foreign Relations PEACE CORPS CLAIMS AGAINST GOVERNMENT UNDER FEDERAL... the Peace Corps retains authority to consider, ascertain, adjust, determine, compromise and...

  1. Compromise, Well-Being, and Action Behaviors in Young Adults in Career Transition

    ERIC Educational Resources Information Center

    Creed, Peter A.; Blume, Kellie

    2013-01-01

    The authors surveyed 186 first-year university students and assessed their level of career compromise associated with making the transition to university. Compromise was operationalized as the discrepancy between the job characteristics of ideal and expected occupations. The authors also assessed career well-being (satisfaction, distress), action…

  2. Compromise, Well-Being, and Action Behaviors in Young Adults in Career Transition

    ERIC Educational Resources Information Center

    Creed, Peter A.; Blume, Kellie

    2013-01-01

    The authors surveyed 186 first-year university students and assessed their level of career compromise associated with making the transition to university. Compromise was operationalized as the discrepancy between the job characteristics of ideal and expected occupations. The authors also assessed career well-being (satisfaction, distress), action…

  3. 38 CFR 1.955 - Regional office Committees on Waivers and Compromises.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... duties, delegations of authority, and all actions required of the Committees on Waivers and Compromises... Compromises to perform the duties and assume the responsibilities delegated by §§ 1.956 and 1.957. The term..., when workload warrants a full-time committee, such designation will be part-time additional duty upon...

  4. 38 CFR 1.955 - Regional office Committees on Waivers and Compromises.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... duties, delegations of authority, and all actions required of the Committees on Waivers and Compromises... Compromises to perform the duties and assume the responsibilities delegated by §§ 1.956 and 1.957. The term..., when workload warrants a full-time committee, such designation will be part-time additional duty upon...

  5. 10 CFR 15.41 - When a claim may be compromised.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false When a claim may be compromised. 15.41 Section 15.41 Energy NUCLEAR REGULATORY COMMISSION DEBT COLLECTION PROCEDURES Compromise of a Claim § 15.41 When a... principal balance of a debt, exclusive of interest, penalties, and administrative costs, exceeds $100,000...

  6. 10 CFR 15.41 - When a claim may be compromised.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... it has not been referred to DOJ for litigation. (b) Unless otherwise provided by law, when the... with the DOJ. The NRC will evaluate the compromise offer, using the factors set forth in this part. If an offer to compromise any debt in excess of $100,000 is acceptable to the NRC, the NRC shall...

  7. 27 CFR 70.484 - Offers in compromise of forfeiture liabilities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... proponent is notified of the acceptance or rejection of the offer. If the offer is rejected, the sum... is notified and the case is closed. Acceptance of an offer in compromise of civil liabilities does not remit criminal liabilities, nor does acceptance of an offer in compromise of criminal...

  8. [Guidelines for chagas disease: Part IV. Chagas disease in immune compromised patients].

    PubMed

    Apt B, Werner; Heitmann G, Ingrid; Jercic L, M Isabel; Jotré M, Leonor; Muñoz C Del V, Patricia; Noemí H, Isabel; San Martin V, Ana M; Sapunar P, Jorge; Torres H, Marisa; Zulantay A, Inés

    2008-08-01

    A summary of different kind of immune suppressed hosts and the importance of Trypanosoma cruzi infection in this group of patients is presented. Then, most relevant aspects of immune compromised host-parasite interaction are analyzed such as the moment of acquiring the infection, immune compromise level, mechanisms of acquisition the infection and geographic region. Clinical features of primary infection and reactivation of infection in chronic Chagasic patients are described making special emphasis in solid organ transplant and BMT. Chagas disease in AIDS patients is discussed including its treatment, follow up, monitoring the immune compromise level and prophylaxis.

  9. 32 CFR 2001.48 - Loss, possible compromise or unauthorized disclosure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... governments normally will not be advised of any security system vulnerabilities that contributed to the... INFORMATION SECURITY OVERSIGHT OFFICE, NATIONAL ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION Safeguarding § 2001.48 Loss, possible compromise or unauthorized disclosure....

  10. 45 CFR 608.2 - Collection, compromise, and use of consumer reporting agencies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) NATIONAL SCIENCE FOUNDATION CLAIMS COLLECTION AND ADMINISTRATIVE OFFSET § 608.2 Collection, compromise, and... briefly describing the nature of the review performed and the conclusion reached shall be made....

  11. 45 CFR 608.2 - Collection, compromise, and use of consumer reporting agencies.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) NATIONAL SCIENCE FOUNDATION CLAIMS COLLECTION AND ADMINISTRATIVE OFFSET § 608.2 Collection, compromise, and... briefly describing the nature of the review performed and the conclusion reached shall be made....

  12. 7 CFR 1956.68 - Compromise or adjustment without debtor's signature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY... Loan Programs and Multi-Family Housing § 1956.68 Compromise or adjustment without debtor's...

  13. Improved soluble expression of the gene encoding amylolytic enzyme Amo45 by fusion with the mobile-loop-region of co-chaperonin GroES in Escherichia coli

    PubMed Central

    2013-01-01

    The gene encoding the amylolytic enzyme Amo45, originating from a metagenomic project, was retrieved by a consensus primer-based approach for glycoside hydrolase (GH) family 57 enzymes. Family 57 contains mainly uncharacterized proteins similar to archaeal thermoactive amylopullulanases. For characterization of these family members soluble, active enzymes have to be produced in sufficient amounts. Heterologous expression of amo45 in E.coli resulted in low yields of protein, most of which was found in inclusion bodies. To improve protein production and to increase the amount of soluble protein, two different modifications of the gene were applied. The first was fusion to an N-terminal His-tag sequence which increased the yield of protein, but still resulted in high amounts of inclusion bodies. Co-expression with chaperones enhanced the amount of soluble protein 4-fold. An alternative modification was the attachment of a peptide consisting of the amino acid sequence of the mobile-loop of the co-chaperonin GroES of E.coli. This sequence improved the soluble protein production 5-fold compared to His6-Amo45 and additional expression of chaperones was unnecessary. PMID:24829536

  14. Improved soluble expression of the gene encoding amylolytic enzyme Amo45 by fusion with the mobile-loop-region of co-chaperonin GroES in Escherichia coli.

    PubMed

    Wang, Lei; Watzlawick, Hildegard; Fridjonsson, Olafur; Hreggvidsson, Gudmundur; Altenbuchner, Josef

    2013-11-01

    The gene encoding the amylolytic enzyme Amo45, originating from a metagenomic project, was retrieved by a consensus primer-based approach for glycoside hydrolase (GH) family 57 enzymes. Family 57 contains mainly uncharacterized proteins similar to archaeal thermoactive amylopullulanases. For characterization of these family members soluble, active enzymes have to be produced in sufficient amounts. Heterologous expression of amo45 in E.coli resulted in low yields of protein, most of which was found in inclusion bodies. To improve protein production and to increase the amount of soluble protein, two different modifications of the gene were applied. The first was fusion to an N-terminal His-tag sequence which increased the yield of protein, but still resulted in high amounts of inclusion bodies. Co-expression with chaperones enhanced the amount of soluble protein 4-fold. An alternative modification was the attachment of a peptide consisting of the amino acid sequence of the mobile-loop of the co-chaperonin GroES of E.coli. This sequence improved the soluble protein production 5-fold compared to His6-Amo45 and additional expression of chaperones was unnecessary.

  15. The chaperonin cycle cannot substitute for prolyl isomerase activity, but GroEL alone promotes productive folding of a cyclophilin-sensitive substrate to a cyclophilin-resistant form.

    PubMed

    von Ahsen, O; Tropschug, M; Pfanner, N; Rassow, J

    1997-08-01

    The chaperonin GroEL and the peptidyl-prolyl cis-trans isomerase cyclophilin are major representatives of two distinct cellular systems that help proteins to adopt their native three-dimensional structure: molecular chaperones and folding catalysts. Little is known about whether and how these proteins cooperate in protein folding. In this study, we have examined the action of GroEL and cyclophilin on a substrate protein in two distinct prolyl isomerization states. Our results indicate that: (i) GroEL binds the same substrate in different prolyl isomerization states. (ii) GroEL-ES does not promote prolyl isomerizations, but even retards isomerizations. (iii) Cyclophilin cannot promote the correct isomerization of prolyl bonds of a GroEL-bound substrate, but acts sequentially after release of the substrate from GroEL. (iv) A denatured substrate with all-native prolyl bonds is delayed in folding by cyclophilin due to isomerization to non-native prolyl bonds; a substrate that has proceeded in folding beyond a stage where it can be bound by GroEL is still sensitive to cyclophilin. (v) If a denatured cyclophilin-sensitive substrate is first bound to GroEL, however, productive folding to a cyclophilin-resistant form can be promoted, even without GroES. We conclude that GroEL and cyclophilin act sequentially and exert complementary functions in protein folding.

  16. Knowledge is power: averting safety-compromising events in the OR.

    PubMed

    Catalano, Kathleen

    2008-12-01

    Surgical procedures can be unpredictable, and safety-compromising events can jeopardize patient safety. Perioperative nurses should be watchful for factors that can contribute to safety-compromising events, as well as the errors that can follow, and know how to avert them if possible. Knowledge is power and increased awareness of patient safety issues and the resources that are available to both health care practitioners and consumers can help perioperative nurses ward off patient safety problems before they occur.

  17. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks

    PubMed Central

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang

    2016-01-01

    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices’ operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors’ messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs. PMID:27657071

  18. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks.

    PubMed

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang

    2016-09-20

    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices' operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors' messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs.

  19. Recognizing and caring for the medically compromised child: 4. Children with other chronic medical conditions.

    PubMed

    Johnstone, S C; Barnard, K M; Harrison, V E

    1999-01-01

    This is the fourth and final part of a series on recognizing and caring for medically compromised children. In this article, an outline of appropriate dental management for children with other more commonly encountered chronic medical conditions is given, together with a description of the disorders and their significance in dentistry. This group includes children with physically handicapping conditions and children with learning difficulties, as well as those who are medically compromised.

  20. A one-appointment impression and centric relation record technique for compromised complete denture patients.

    PubMed

    Ansari, I H

    1997-09-01

    This article describes a two-in-one modified custom tray and record block system that is recommended for compromised elderly patients. Custom trays, which are made on primary casts and formed from a patient's functionally corrected old dentures, are used to make final impressions and centric jaw relation records in one clinical appointment. The clinical visits are reduced without compromising the quality of denture construction.

  1. Respiratory Compromise as a New Paradigm for the Care of Vulnerable Hospitalized Patients.

    PubMed

    Morris, Timothy A; Gay, Peter C; MacIntyre, Neil R; Hess, Dean R; Hanneman, Sandra K; Lamberti, James P; Doherty, Dennis E; Chang, Lydia; Seckel, Maureen A

    2017-04-01

    Acute respiratory compromise describes a deterioration in respiratory function with a high likelihood of rapid progression to respiratory failure and death. Identifying patients at risk for respiratory compromise coupled with monitoring of patients who have developed respiratory compromise might allow earlier interventions to prevent or mitigate further decompensation. The National Association for the Medical Direction of Respiratory Care (NAMDRC) organized a workshop meeting with representation from many national societies to address the unmet needs of respiratory compromise from a clinical practice perspective. Respiratory compromise may arise de novo or may complicate preexisting lung disease. The group identified distinct subsets of respiratory compromise that present similar opportunities for early detection and useful intervention to prevent respiratory failure. The subtypes were characterized by the pathophysiological mechanisms they had in common: impaired control of breathing, impaired airway protection, parenchymal lung disease, increased airway resistance, hydrostatic pulmonary edema, and right-ventricular failure. Classification of acutely ill respiratory patients into one or more of these categories may help in selecting the screening and monitoring strategies that are most appropriate for the patient's particular pathophysiology. Standardized screening and monitoring practices for patients with similar mechanisms of deterioration may enhance the ability to predict respiratory failure early and prevent its occurrence.

  2. In vitro models to estimate drug penetration through the compromised stratum corneum barrier.

    PubMed

    Engesland, André; Škalko-Basnet, Nataša; Flaten, Gøril Eide

    2016-11-01

    The phospholipid vesicle-based permeation assay (PVPA) is a recently established in vitro stratum corneum model to estimate the permeability of intact and healthy skin. The aim here was to further evolve this model to mimic the stratum corneum in a compromised skin barrier by reducing the barrier functions in a controlled manner. To mimic compromised skin barriers, PVPA barriers were prepared with explicitly defined reduced barrier function and compared with literature data from both human and animal skin with compromised barrier properties. Caffeine, diclofenac sodium, chloramphenicol and the hydrophilic marker calcein were tested to compare the PVPA models with established models. The established PVPA models mimicking the stratum corneum in healthy skin showed good correlation with biological barriers by ranking drugs similar to those ranked by the pig ear skin model and were comparable to literature data on permeation through healthy human skin. The PVPA models provided reproducible and consistent results with a distinction between the barriers mimicking compromised and healthy skin. The trends in increasing drug permeation with an increasing degree of compromised barriers for the model drugs were similar to the literature data from other in vivo and in vitro models. The PVPA models have the potential to provide permeation predictions when investigating drugs or cosmeceuticals intended for various compromised skin conditions and can thus possibly reduce the time and cost of testing as well as the use of animal testing in the early development of drug candidates, drugs and cosmeceuticals.

  3. Compromised decision making and the effects of manipulating physical states on human judgments.

    PubMed

    De Los Reyes, Andres; Aldao, Amelia; Kundey, Shannon M A; Lee, Bern G; Molina, Sabrina

    2012-01-01

    Nonmorally based decision making between two equitable objects often involves degrading the unchosen object and promoting the chosen object ("postdecisional dissonance"). One can extinguish these thought processes with the physical act of hand-washing ("clean slate" effects; [Lee & Schwarz (2010). Washing away postdecisional dissonance. Science, 328, 709.]). However, clean slate effects might not characterize all nonmorally based decision making, particularly for people who mentally "get stuck" making decisions (i.e., compromised decision making). We administered a clean slate task to 48 undergraduates (64.6% females; mean = 21.34 years, standard deviation = 4.06 years; 75% Caucasian), and identified individuals reporting relatively high-compromised versus low-compromised decision making (e.g., self-reported repetitive thought processes and generalized anxiety symptoms). Only individuals reporting relatively high-compromised decision making continued to express postdecisional dissonance even after hand-washing. Behavioral markers of clean slate effects might result in identifying phenotypes associated with psychological concerns typified by compromised decision making. © 2011 Wiley Periodicals, Inc.

  4. REACT: An Interprofessional Education and Safety Program to Recognize and Manage the Compromised Obstetric Patient.

    PubMed

    Baird, Suzanne McMurtry; Graves, Cornelia R

    2015-01-01

    In recent years, there has been an increase in the number of pregnancies complicated by preexisting medical conditions as well as an increase in maternal morbidity and mortality in the United States. The goal of the REACT quality and safety initiative was to reduce maternal morbidity and mortality by providing an interprofessional education program for recognizing and managing the woman who becomes compromised during pregnancy, childbirth, or the puerperium. REACT is an acronym for Recognize, Educate, Activate, Communicate, and Treat early signs and symptoms of maternal compromise. Early signs and symptoms of maternal compromise outlined in the REACT program are similar to recently published recommendations by the American College of Obstetricians and Gynecologists, the Centers for Disease Control and Prevention, the Society for Maternal-Fetal Medicine, the Health Resources and Services Administration, the Association of Women's Health, Obstetric and Neonatal Nurses, and the American College of Nurse-Midwives.

  5. Central nervous system compromise in primary Sjögren's syndrome.

    PubMed

    Anaya, Juan-Manuel; Villa, Luis A; Restrepo, Lucas; Molina, Jose F; Mantilla, Rubén D; Vargas, Sergio

    2002-08-01

    Central nervous system (CNS) involvement in primary Sjögren's syndrome (SS) is poorly understood, and its frequency as well as its manifestations are subjects of controversy. The current study was undertaken to determine the prevalence and the clinical and immunogenetic characteristics of CNS compromise in a well defined group of patients with primary SS. In this retrospective study, patients fulfilled the European classification criteria. Among 120 patients with primary SS, 3 (2.5%) had CNS compromise (multiple sclerosis-like illness, complicated migraine, and optic neuritis with epilepsy). The CNS involvement coincided with the onset of sicca symptoms in 1 case. All 3 patients carried the human leukocyte antigen (HLA) DQB1*0303 allele and tested positive for anti-Ro antibodies, but not for anti-cardiolipin antibodies. Although rare, CNS compromise in primary SS can be the presenting manifestation of the disease in a few cases, and may be severe and varied.

  6. Anesthesia for patients with respiratory disease and/or airway compromise.

    PubMed

    Grubb, Tamara

    2010-05-01

    Because the airway extends from the oral or nasal cavity to the alveoli, airway compromise or respiratory disease has numerous manifestations. Complications can be encountered in both the upper and lower airways and include a vast range of problems including laryngeal paralysis, collapsing trachea, pneumonia, pulmonary edema, pneumothorax, intrathoracic masses and diaphragmatic hernias. Anesthesia can cause further complications because anesthetic drugs and equipment can exacerbate or even cause airway difficulties and respiratory compromise. When anesthetizing patients with respiratory disease or airway complications, the choice of the actual anesthetic drugs is not necessarily dictated by the presence of respiratory compromise, but rather by the overall health of the patient. The choice of anesthetic technique (e.g., method of induction, method of intubation, use of positive-pressure ventilation, etc.), on the other hand, is often critical.

  7. Clinicopathologic subtypes and compromise of lymph nodes in patients with breast cancer

    PubMed Central

    Jaime Jans, B; Nicolás Escudero, M; Dahiana Pulgar, B; Francisco Acevedo, C; César Sánchez, R; Camus, A Mauricio

    2014-01-01

    Breast cancer (BC) is currently a heterogeneous disease with variations in clinical behaviour. Classification according to subtypes has allowed progress in the individualisation of treatment. The objective of this study is to evaluate the risk of axillary node compromise in patients with BC, according to clinicopathologic subtypes. Materials and methods are a retrospective, descriptive-analytical study. All patients that had undergone surgery for invasive BC were included, with the study of sentinel lymph nodes (SLNs) at Hospital Clínico de la Pontificia Universidad Católica, between May 1999 and December 2012. The results showed 632 patients fulfilled the inclusion criteria, with the median age being 55 years (range: 28–95), and 559 (88.4%) patients presented with estrogen receptor and/or progesterone receptor positive tumours. Luminal A: 246 patients (38.9%), luminal B: 243 (38.4%), luminal not otherwise specified: 70 (11.1%) triple negative (TN): 60 (9.5%) and over expression of epidermal growth factor type 2 receptor (HER2 positive): 13 (2.1%). Luminal tumours displayed a greater risk of metastasis in the SLNs, but this difference was not statistically significant (p = 0.67). TN and HER2 positive tumours presented the greatest proportion of metastatic compromise in non-sentinel lymph nodes (non-SLNs) (57.1% and 50%, respectively). The presence of macrometastasis (MAM) in the SLN was associated with a greater risk of compromise of the non-SLN. Conclusions: Luminal tumours are the most frequent and present a greater proportion of axillary lymph node compromise, without being statistically significant. TN and HER2 positive tumours tend to have a higher axillary compromise; however, this was not statistically significant in either. Only the presence of MAM in SLNs displayed a statistically significantly association in the compromise of non-SLNs. PMID:25114720

  8. Clinicopathologic subtypes and compromise of lymph nodes in patients with breast cancer.

    PubMed

    Jaime Jans, B; Nicolás Escudero, M; Dahiana Pulgar, B; Francisco Acevedo, C; César Sánchez, R; Camus, A Mauricio

    2014-01-01

    Breast cancer (BC) is currently a heterogeneous disease with variations in clinical behaviour. Classification according to subtypes has allowed progress in the individualisation of treatment. The objective of this study is to evaluate the risk of axillary node compromise in patients with BC, according to clinicopathologic subtypes. Materials and methods are a retrospective, descriptive-analytical study. All patients that had undergone surgery for invasive BC were included, with the study of sentinel lymph nodes (SLNs) at Hospital Clínico de la Pontificia Universidad Católica, between May 1999 and December 2012. The results showed 632 patients fulfilled the inclusion criteria, with the median age being 55 years (range: 28-95), and 559 (88.4%) patients presented with estrogen receptor and/or progesterone receptor positive tumours. Luminal A: 246 patients (38.9%), luminal B: 243 (38.4%), luminal not otherwise specified: 70 (11.1%) triple negative (TN): 60 (9.5%) and over expression of epidermal growth factor type 2 receptor (HER2 positive): 13 (2.1%). Luminal tumours displayed a greater risk of metastasis in the SLNs, but this difference was not statistically significant (p = 0.67). TN and HER2 positive tumours presented the greatest proportion of metastatic compromise in non-sentinel lymph nodes (non-SLNs) (57.1% and 50%, respectively). The presence of macrometastasis (MAM) in the SLN was associated with a greater risk of compromise of the non-SLN. Luminal tumours are the most frequent and present a greater proportion of axillary lymph node compromise, without being statistically significant. TN and HER2 positive tumours tend to have a higher axillary compromise; however, this was not statistically significant in either. Only the presence of MAM in SLNs displayed a statistically significantly association in the compromise of non-SLNs.

  9. Compromise Approach-Based Genetic Algorithm for Constrained Multiobjective Portfolio Selection Model

    NASA Astrophysics Data System (ADS)

    Li, Jun

    In this paper, fuzzy set theory is incorporated into a multiobjective portfolio selection model for investors’ taking into three criteria: return, risk and liquidity. The cardinality constraint, the buy-in threshold constraint and the round-lots constraints are considered in the proposed model. To overcome the difficulty of evaluation a large set of efficient solutions and selection of the best one on non-dominated surface, a compromise approach-based genetic algorithm is presented to obtain a compromised solution for the proposed constrained multiobjective portfolio selection model.

  10. 13 CFR 108.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies...

  11. 13 CFR 108.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies...

  12. 13 CFR 108.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies...

  13. 13 CFR 107.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage)...

  14. 13 CFR 107.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage)...

  15. 13 CFR 107.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage)...

  16. 13 CFR 107.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage)...

  17. Career Development Strategies as Moderators between Career Compromise and Career Outcomes in Emerging Adults

    ERIC Educational Resources Information Center

    Creed, Peter A.; Hughes, Trinette

    2013-01-01

    The authors surveyed 130 first-year university students (80% female; mean age 20.5) and assessed (a) the level of career compromise they reported between their ideal and enrolled university programs, (b) their career-related strategies, (c) their perceptions of employability, and (d) their career-related distress. The authors tested a model that…

  18. Effects of Warmth of Interaction, Accuracy of Understanding, and the Proposal of Compromises on Listener's Behavior

    ERIC Educational Resources Information Center

    Johnson, David W.

    1971-01-01

    The results of this experiment demonstrate a causal relationship (a) between the expressed accuracy of understanding and the proposal of compromises and the induction of cooperation in a negotiation situation and (b) between the expressed warmth and degree of favorableness of interpersonal attitudes, thus giving support to the efficacy of Rogerian…

  19. Is patient confidentiality compromised with the electronic health record?: a position paper.

    PubMed

    Wallace, Ilse M

    2015-02-01

    In order for electronic health records to fulfill their expected benefits, protection of privacy of patient information is key. Lack of trust in confidentiality can lead to reluctance in disclosing all relevant information, which could have grave consequences. This position paper contemplates whether patient confidentiality is compromised by electronic health records. The position that confidentiality is compromised was supported by the four bioethical principles and argued that despite laws and various safeguards to protect patients' confidentiality, numerous data breaches have occurred. The position that confidentiality is not compromised was supported by virtue ethics and a utilitarian viewpoint and argued that safeguards keep information confidential and the public feels relatively safe with the electronic health record. The article concludes with an ethically superior position that confidentiality is compromised with the electronic health record. Although organizational and governmental ways of enhancing the confidentiality of patient information within the electronic health record facilitate confidentiality, the ultimate responsibility of maintaining confidentiality rests with the individual end-users and their ethical code of conduct. The American Nurses Association Code of Ethics for nurses calls for nurses to be watchful with data security in electronic communications.

  20. Adolescent Occupational Aspirations: Test of Gottfredson's Theory of Circumscription and Compromise

    ERIC Educational Resources Information Center

    Cochran, Daria B.; Wang, Eugene W.; Stevenson, Sarah J.; Johnson, Leah E.; Crews, Charles

    2011-01-01

    The authors investigated the relationship between adolescent occupational aspirations and midlife career success. The model for adolescent occupational aspirations was derived from Gottfredson's (1981) theory of circumscription and compromise. The authors hypothesized that parental socioeconomic status (SES), ability, and gender predict adolescent…

  1. 32 CFR 310.14 - Notification when information is lost, stolen, or compromised.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... purposes, such as identity theft, fraud, stalking, etc. The personal impact on the affected individual may... the Federal Trade Commission's public Web site on identity theft at http://www.consumer.gov/idtheft... the individual of any loss, theft, or compromise (See also, § 310.50 for reporting of the breach...

  2. 32 CFR 310.14 - Notification when information is lost, stolen, or compromised.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... purposes, such as identity theft, fraud, stalking, etc. The personal impact on the affected individual may... the Federal Trade Commission's public Web site on identity theft at http://www.consumer.gov/idtheft... the individual of any loss, theft, or compromise (See also, § 310.50 for reporting of the breach...

  3. 32 CFR 310.14 - Notification when information is lost, stolen, or compromised.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... purposes, such as identity theft, fraud, stalking, etc. The personal impact on the affected individual may... the Federal Trade Commission's public Web site on identity theft at http://www.consumer.gov/idtheft... the individual of any loss, theft, or compromise (See also, § 310.50 for reporting of the breach...

  4. 32 CFR 310.14 - Notification when information is lost, stolen, or compromised.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... purposes, such as identity theft, fraud, stalking, etc. The personal impact on the affected individual may... the Federal Trade Commission's public Web site on identity theft at http://www.consumer.gov/idtheft... the individual of any loss, theft, or compromise (See also, § 310.50 for reporting of the breach...

  5. 32 CFR 310.14 - Notification when information is lost, stolen, or compromised.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... purposes, such as identity theft, fraud, stalking, etc. The personal impact on the affected individual may... the Federal Trade Commission's public Web site on identity theft at http://www.consumer.gov/idtheft... the individual of any loss, theft, or compromise (See also, § 310.50 for reporting of the breach...

  6. TEMPORAL ASSOCIATION BETWEEN PULMONARY AND SYSTEMIC EFFECTS OF PARTICULATE MATTER IN HEALTHY AND CARDIOVASCULAR COMPROMISED RATS

    EPA Science Inventory

    Temporal association between pulmonary and systemic effects of particulate matter in healthy and cardiovascular compromised rats

    Urmila P. Kodavanti, Mette C. Schladweiler, Allen D. Ledbetter, Russ Hauser*, David C. Christiani*, John McGee, Judy R. Richards, Daniel L. Co...

  7. 13 CFR 108.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies...

  8. 13 CFR 108.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NEW MARKETS VENTURE CAPITAL (âNMVCâ) PROGRAM SBA Financial Assistance for NMVC Companies...

  9. 78 FR 53702 - User Fees for Processing Installment Agreements and Offers in Compromise

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ...). The public hearing will be held in the IRS Auditorium beginning at 10 a.m. at the Internal Revenue... proposed fees balance the need to recover costs with the goals of encouraging the use of installment... proposed fee balances the need to recover costs with the goal of encouraging offers in compromise. The...

  10. Does Low Self-Esteem Predict Health Compromising Behaviours among Adolescents?

    ERIC Educational Resources Information Center

    McGee, Rob; Williams, Sheila

    2000-01-01

    Study examined the predictive association for both global and academic self esteem among students ages 9-13 in a large sample of New Zealanders. Results showed levels of global self esteem significantly predicted adolescent reports of problem eating, suicidal ideation, and multiple compromising behaviors. Implications are discussed for the…

  11. 48 CFR 239.7102-2 - Compromising emanations-TEMPEST or other standard.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Compromising emanations-TEMPEST or other standard. 239.7102-2 Section 239.7102-2 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING ACQUISITION OF...

  12. 45 CFR 30.4 - Compromise, waiver, or disposition under other statutes not precluded.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Compromise, waiver, or disposition under other statutes not precluded. 30.4 Section 30.4 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... States Code and the Federal Claims Collection Standards, 31 CFR parts 900 through 904. Any statute...

  13. 45 CFR 30.4 - Compromise, waiver, or disposition under other statutes not precluded.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Compromise, waiver, or disposition under other statutes not precluded. 30.4 Section 30.4 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... States Code and the Federal Claims Collection Standards, 31 CFR parts 900 through 904. Any statute...

  14. Inadequate satellite cell replication compromises muscle regrowth following postnatal nutrient restriction

    USDA-ARS?s Scientific Manuscript database

    Perinatal growth impairment permanently compromises skeletal muscle mass. The present study assessed the contribution of muscle satellite cell replicative capacity to this deficit. Mouse dams were fed either a low protein (LP, n=7) or control (C, n=6) diet during lactation. Pups were weaned at 21 d ...

  15. 28 CFR 71.54 - Collection and compromise of liabilities imposed by Agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Collection and compromise of liabilities...) IMPLEMENTATION OF THE PROVISIONS OF THE PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 Assignment of Responsibilities... and civil penalties imposed under the Program Fraud Civil Remedies Act of 1986, and, subsequent to...

  16. Using Emergence Theory-Based Curriculum to Teach Compromise Skills to Students with Autistic Spectrum Disorders

    ERIC Educational Resources Information Center

    Fein, Lance; Jones, Don

    2015-01-01

    This study addresses the compromise skills that are taught to students diagnosed with autistic spectrum disorders (ASD) and related social and communication deficits. A private school in the southeastern United States implemented an emergence theory-based curriculum to address these skills, yet no formal analysis was conducted to determine its…

  17. 40 CFR 1620.6 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Authority to adjust, determine, compromise, and settle. 1620.6 Section 1620.6 Protection of Environment CHEMICAL SAFETY AND HAZARD INVESTIGATION BOARD ADMINISTRATIVE CLAIMS ARISING UNDER THE FEDERAL TORT CLAIMS ACT § 1620.6 Authority to...

  18. 13 CFR 107.1710 - SBA authority to collect or compromise its claims.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage) Miscellaneous...

  19. Unconsciously competing goals can collaborate or compromise as well as win or lose.

    PubMed

    Carruthers, Peter

    2014-04-01

    This commentary offers a friendly extension of Huang & Bargh's (H&B's) account. Not only do active goals sometimes operate unconsciously to dominate or preempt others, but simultaneously active goals can also collaborate or compromise in shaping behavior. Because neither goal wins complete control of behavior, the result may be that each is only partly satisfied.

  20. Happenstance and Compromise: A Gendered Analysis of Students' Computing Degree Course Selection

    ERIC Educational Resources Information Center

    Lang, Catherine

    2010-01-01

    The number of students choosing to study computing at university continues to decline this century, with an even sharper decline in female students. This article presents the results of a series of interviews with university students studying computing courses in Australia that uncovered the influence of happenstance and compromise on course…

  1. 10 CFR 1015.104 - Compromise, waiver, or disposition under other statutes not precluded.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Compromise, waiver, or disposition under other statutes not precluded. 1015.104 Section 1015.104 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) COLLECTION... applicable laws and regulations will generally take precedence over this part....

  2. Career Development Strategies as Moderators between Career Compromise and Career Outcomes in Emerging Adults

    ERIC Educational Resources Information Center

    Creed, Peter A.; Hughes, Trinette

    2013-01-01

    The authors surveyed 130 first-year university students (80% female; mean age 20.5) and assessed (a) the level of career compromise they reported between their ideal and enrolled university programs, (b) their career-related strategies, (c) their perceptions of employability, and (d) their career-related distress. The authors tested a model that…

  3. 20 CFR 410.565 - Collection and compromise of claims for overpayment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Collection and compromise of claims for overpayment. 410.565 Section 410.565 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits §...

  4. 20 CFR 410.565 - Collection and compromise of claims for overpayment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Collection and compromise of claims for overpayment. 410.565 Section 410.565 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits §...

  5. Fungemia and interstitial lung compromise caused by Malassezia sympodialis in a pediatric patient.

    PubMed

    Aguirre, Clarisa; Euliarte, Cristina; Finquelievich, Jorge; Sosa, María de los Ángeles; Giusiano, Gustavo

    2015-01-01

    A case of fungemia with interstitial lung compromise caused by Malassezia sympodialis is reported in an obese pediatric patient on long-term treatment with inhaled corticosteroids for asthma. The patient was hospitalized due to a post-surgical complication of appendicitis. The patient was treated with amphotericin B for 3 weeks, with good clinical evolution and subsequent negative cultures.

  6. Comments on James Q. Wilson's Compromise on Affirmative Action in American Higher Education.

    ERIC Educational Resources Information Center

    Murray, Charles; And Others

    1997-01-01

    Provides responses from a small group of conservative scholars concerning the compromise proposed by Dr. James Q. Wilson indicating that the nation will allow some affirmative action in the form of race-based preferential admissions at the undergraduate level, but not in graduate programs. (GR)

  7. TEMPORAL ASSOCIATION BETWEEN PULMONARY AND SYSTEMIC EFFECTS OF PARTICULATE MATTER IN HEALTHY AND CARDIOVASCULAR COMPROMISED RATS

    EPA Science Inventory

    Temporal association between pulmonary and systemic effects of particulate matter in healthy and cardiovascular compromised rats

    Urmila P. Kodavanti, Mette C. Schladweiler, Allen D. Ledbetter, Russ Hauser*, David C. Christiani*, John McGee, Judy R. Richards, Daniel L. Co...

  8. 31 CFR 5.7 - When will Treasury entities compromise a Treasury debt?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false When will Treasury entities compromise a Treasury debt? 5.7 Section 5.7 Money and Finance: Treasury Office of the Secretary of the Treasury TREASURY DEBT COLLECTION Procedures To Collect Treasury Debts § 5.7 When will Treasury...

  9. 7 CFR 1956.66 - Compromise and adjustment of nonjudgment debts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...'s essential family living expenses, and farm or business operation expenses necessary to continue... SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT... Programs and Multi-Family Housing § 1956.66 Compromise and adjustment of nonjudgment debts....

  10. 49 CFR 599.516 - Collection of assessed or compromised civil penalties.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Collection of assessed or compromised civil penalties. 599.516 Section 599.516 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) REQUIREMENTS AND PROCEDURES FOR CONSUMER ASSISTANCE TO...

  11. 10 CFR 1014.5 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Authority to adjust, determine, compromise, and settle. 1014.5 Section 1014.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) ADMINISTRATIVE CLAIMS UNDER... receive and act on tort claims at Headquarters and field locations are authorized to act on claims. ...

  12. 10 CFR 1014.5 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Authority to adjust, determine, compromise, and settle. 1014.5 Section 1014.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) ADMINISTRATIVE CLAIMS UNDER... receive and act on tort claims at Headquarters and field locations are authorized to act on claims. ...

  13. 10 CFR 1014.5 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Authority to adjust, determine, compromise, and settle. 1014.5 Section 1014.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) ADMINISTRATIVE CLAIMS UNDER... receive and act on tort claims at Headquarters and field locations are authorized to act on claims. ...

  14. 10 CFR 1014.5 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Authority to adjust, determine, compromise, and settle. 1014.5 Section 1014.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) ADMINISTRATIVE CLAIMS UNDER... receive and act on tort claims at Headquarters and field locations are authorized to act on claims. ...

  15. 10 CFR 1014.5 - Authority to adjust, determine, compromise, and settle.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Authority to adjust, determine, compromise, and settle. 1014.5 Section 1014.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) ADMINISTRATIVE CLAIMS UNDER... receive and act on tort claims at Headquarters and field locations are authorized to act on claims. ...

  16. 15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities...

  17. 26 CFR 301.6331-3 - Restrictions on levy while offers to compromise are pending.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Restrictions on levy while offers to compromise are pending. 301.6331-3 Section 301.6331-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Seizure of Property...

  18. 26 CFR 301.6331-3 - Restrictions on levy while offers to compromise are pending.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 18 2011-04-01 2011-04-01 false Restrictions on levy while offers to compromise are pending. 301.6331-3 Section 301.6331-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Seizure of Property...

  19. 26 CFR 301.6331-3 - Restrictions on levy while offers to compromise are pending.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 18 2014-04-01 2014-04-01 false Restrictions on levy while offers to compromise are pending. 301.6331-3 Section 301.6331-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Seizure of Property...

  20. Tragic Choices and Moral Compromise: The Ethics of Allocating Kidneys for Transplantation

    PubMed Central

    Hoffmaster, Barry; Hooker, Cliff

    2013-01-01

    Context For almost a decade, the Kidney Transplantation Committee of the United Network for Organ Sharing has been striving to revise its approach to allocating kidneys from deceased donors for transplantation. Two fundamental values, equality and efficiency, are central to distributing this scarce resource. The prevailing approach gives primacy to equality in the temporal form of first-come, first-served, whereas the motivation for a new approach is to redeem efficiency by increasing the length of survival of transplanted kidneys and their recipients. But decision making about a better way of allocating kidneys flounders because it is constrained by the amorphous notion of “balancing” values. Methods This article develops a more fitting, productive approach to resolving the conflict between equality and efficiency by embedding the notion of compromise in the analysis of a tragic choice provided by Guido Calabresi and Philip Bobbitt. For Calabresi and Bobbitt, the goals of public policy with respect to tragic choices are to limit tragedy and to deal with the irreducible minimum of tragedy in the least offensive way. Satisfying the value of efficiency limits tragedy, and satisfying the value of equality deals with the irreducible minimum of tragedy in the least offensive way. But both values cannot be completely satisfied simultaneously. Compromise is occasioned when not all the several obligations that exist in a situation can be met and when neglecting some obligations entirely in order to fulfill others entirely is improper. Compromise is amalgamated with the notion of a tragic choice and then used to assess proposals for revising the allocation of kidneys considered by the Kidney Transplantation Committee. Findings Compromise takes two forms in allocating kidneys: it occurs within particular approaches to allocating kidneys because neither equality nor efficiency can be fully satisfied, and it occurs over the course of sequential approaches to allocating

  1. Clinical outcomes of compromised side branch (stent jail) after coronary stenting with the NIR stent.

    PubMed

    Bhargava, B; Waksman, R; Lansky, A J; Kornowski, R; Mehran, R; Leon, M B

    2001-11-01

    Acute side-branch (SB) compromise or occlusion stent jail after native coronary stenting is a matter of concern. Attempts at maintaining SB patency can be a technical challenge. The purpose of this study was to determine the clinical impact of SB compromise or occlusion in patients undergoing stenting of parent vessel lesions. We evaluated in-hospital and long-term clinical outcomes (death, Q-wave myocardial infarction, and repeat revascularization rates at 6 months) in 318 consecutive patients undergoing NIR stent implantation across an SB. Based on independent angiographic analysis, 218 (68.6%) patients had no poststent SB compromise, 85 (26.7%) patients had narrowed SB (> 70% narrowing, without total occlusion), and 15 (4.7%) patients had an occluded SB after stent implantation. The baseline patient and lesion characteristics were similar between the groups. Procedural success was 100%. Patients with SB occlusion had a higher stents/lesion ratio (P < 0.006). Side-branch occlusion was associated with higher in-hospital ischemic complications (Q-wave myocardial infarction, 7%; non-Q-wave myocardial infarction, 20%; P < 0.05) compared to patients with SB compromise or normal SB. At 6-month follow-up, there was a trend for more myocardial infarctions in the group with SB occlusion during the index procedure (Q-wave myocardial infarction, 7% vs. 1% in the narrowed and 0% in normal SB; P = 0.09). However, late target lesion revascularization and mortality were similar in the three groups (P = 0.91). SB occlusion after parent vessel stenting is associated with more frequent in-hospital Q-wave and non-Q-wave myocardial infarctions. However, with the NIR stent, side-branch compromise or occlusion does not influence late (6 month) major adverse events, including death, myocardial infarction, or need for repeat revascularization.

  2. Influence of political opposition and compromise on conservation outcomes in the Tongass National Forest, Alaska.

    PubMed

    Beier, Colin M

    2008-12-01

    To understand how a highly contentious policy process influenced a major conservation effort, I examined the origins, compromises, and outcomes of the Alaska National Interest Lands Conservation Act of 1980 (ANILCA) for the Tongass National Forest. Tongass wilderness designation was among the most controversial issues in the ANILCA debate, and it faced strong opposition from influential lawmakers, land managers, and Alaska residents. To investigate the influence of this opposition on Tongass conservation outcomes, I conducted a gap analysis of Tongass reserves and a policy analysis of the ANILCA debate and traced the influence of specific interests through the amendments, negotiations, and resulting compromises needed to enact ANILCA. Overall, I found that Tongass reserves comprise a broadly representative cross-section of ecosystems and species habitats in southeastern Alaska. Redrawn reserve boundaries, industry subsidies, and special access regulations reflected compromises to minimize the impact of wilderness conservation on mining, timber, and local stakeholder interests, respectively. Fragmentation of the Admiralty Island National Monument-the most ecologically valuable and politically controversial reserve-resulted from compromises with Alaskan Native (indigenous peoples of Alaska) corporations and timber interests. Despite language to accommodate "reasonable access" to wilderness reserves, ongoing access limitations highlight the concerns of Alaska residents that opposed ANILCA several decades ago. More broadly, the Tongass case suggests that early and ambitious conservation action may offset strong political opposition; compromises needed to establish key reserves often exacerbate development impacts in unprotected areas; and efforts to minimize social conflicts are needed to safeguard the long-term viability of conservation measures.

  3. Predicting intrapartum fetal compromise using the fetal cerebro-umbilical ratio.

    PubMed

    Sabdia, S; Greer, R M; Prior, T; Kumar, S

    2015-05-01

    The aim of this study was to explore the association between the cerebro-umbilical ratio measured at 35-37 weeks and intrapartum fetal compromise. This retrospective cross sectional study was conducted at the Mater Mothers' Hospital in Brisbane, Australia. Maternal demographics and fetal Doppler indices at 35-37 weeks gestation for 1381 women were correlated with intrapartum and neonatal outcomes. Babies born by caesarean section or instrumental delivery for fetal compromise had the lowest median cerebro-umbilical ratio 1.60 (IQR 1.22-2.08) compared to all other delivery groups (vaginal delivery, emergency delivery for failure to progress, emergency caesarean section for other reasons or elective caesarean section). The percentage of infants with a cerebro-umbilical ratio <10th centile that required emergency delivery (caesarean section or instrumental delivery) for fetal compromise was 22%, whereas only 7.3% of infants with a cerebro-umbilical ratio between the 10th-90th centile and 9.6% of infants with a cerebro-umbilical ratio > 90th centile required delivery for the same indication (p < 0.001). A lower cerebro-umbilical ratio was associated with an increased risk of emergency delivery for fetal compromise, OR 2.03 (95% CI 1.41-2.92), p < 0.0001. This study suggests that a low fetal cerebro-umbilical ratio measured at 35-37 weeks is associated with a greater risk of intrapartum compromise. This is a relatively simple technique which could be used to risk stratify women in diverse healthcare settings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Factors influencing treatment decision-making for maintaining or extracting compromised teeth.

    PubMed

    Lang-Hua, Bich Hue; McGrath, Colman P J; Lo, Edward C M; Lang, Niklaus P

    2014-01-01

    To evaluate treatment decision-making with respect to maintaining periodontally compromised teeth among dentists with or without postgraduate qualifications in implant dentistry. A series of patient scenarios with varying degrees of periodontal disease levels was presented to dental practitioners. Practitioners' decision-making outcome was determined, and intention to retain the compromised teeth was analyzed in bivariate and regression analyses (accounting for postgraduate implant training, gender, years in dental practice, and implant placement experience). This study involved 30 dental practitioners with postgraduate implant qualifications (GDPP), 33 dental practitioners without postgraduate implant qualifications (GDP), and 27 practitioners undergoing training for postgraduate implant qualifications (GDPT). Variations in treatment decision-making were evident between the three groups. Differences in treatment approaches to retaining compromised teeth were apparent. Furthermore, variations in rehabilitation of extracted scenarios existed in terms of use of implant and number of implants need for rehabilitation. Accounting for dentist and practice factors in regression analyses, GDPP/GDPT were three times as likely to retain periodontally compromised upper molar, with or without pain, compared to GDP (without pain OR 3.10, 95%CI 1.04, 10.62 P = 0.04; with pain OR 3.08, 95%CI 1.09, 8.14 P = 0.03). Variations in treatment decision-making with respect to retaining periodontally compromised teeth exist between dental practitioners with and those without postgraduate training in implant dentistry. Furthermore differences in management approaches in how they would retain the teeth or rehabilitate the dental arch were apparent. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  5. Tail loss compromises immunity in the many-lined skink, Eutropis multifasciata

    NASA Astrophysics Data System (ADS)

    Kuo, Chi-Chien; Yao, Chiou-Ju; Lin, Te-En; Liu, Hsu-Che; Hsu, Yu-Cheng; Hsieh, Ming-Kun; Huang, Wen-San

    2013-04-01

    Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies.

  6. A libertarian perspective on the stem cell debate: compromising the uncompromisible.

    PubMed

    Block, Walter

    2010-08-01

    The present paper attempts to forge a compromise between those who maintain that stem cell research is out-and-out murder of young helpless human beings and those who favor this practice. The compromise is predicated upon the libertarian theory of private property rights. Starting out with the premise that not only the fetus but even the fertilized egg is a human being, with all rights thereto, it offers a competition between those who fertilize eggs for research and those who wish to adopt them. If and only if the former win this competition will they be allowed to use these very young human beings for the purposes they have constructed them. This is justified on grounds of avoiding child abuse.

  7. Sterile diets for the immuno-compromised: Is there a need?

    NASA Astrophysics Data System (ADS)

    Butterweck, Joseph S.

    1995-02-01

    There is a general misunderstanding in the radiation processing industry about the use of sterile diets in the medical profession. Sterile diets are used on a limited basis in hospitals that specialize in cancer treatment and organ transplants. These patients are severely immuno-compromised. There are many other patients that are immuno-compromised that do not require sterile diets. These patients may require a diet that is pathogen-free and are aslo "low-microbial diets". Nosocomial infections have become a major issue in US hospitals. The "infection control committee" is the focus group responsible to assure nosocomial infections incidence are below the hospital goals. Application of ionizing radiation to sterilize diets has not been chosen because the product is not available at a reasonable total cost. This paper will discuss the hospitals views.

  8. Rescue of a periodontally compromised tooth by non-surgical treatment: a case report

    PubMed Central

    2016-01-01

    Purpose This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar. Methods A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period. Results All periodontal parameters were improved. There were dramatic decreases (3–6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period. Conclusions Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation. PMID:27127693

  9. The use of bonded partial ceramic restorations to recover heavily compromised teeth.

    PubMed

    Politano, Gianfranco; Fabianelli, Andrea; Papacchini, Federica; Cerutti, Antonio

    Restorative procedures are accompanied by a reduction of tooth stability, a decrease of fracture resistance, and an increase in deflection of weakened cusps. The choice between a direct or an indirect restorative technique, mainly in posterior areas, is a challenge, and involves biomechanical, anatomical, functional, esthetic, and financial considerations. In this article, the pros and cons of direct restorations are examined, as well as an analysis of indirect restorations and an overview of dental ceramics. In particular, several clinical uses of lithium disilicate overlays with a circumferential adhesive ferrule effect are proposed: heavily compromised vital teeth with thin walls, cracked teeth, and endodontically treated molars. Clinical procedures are described step by step on the basis of data from scientific literature. In conclusion, the use of lithium disilicate in combination with adhesive technologies can lead to a more conservative, economic, and esthetic approach in the restoration of heavily compromised teeth.

  10. Early Visual Deprivation Severely Compromises the Auditory Sense of Space in Congenitally Blind Children

    PubMed Central

    Vercillo, Tiziana; Burr, David; Gori, Monica

    2016-01-01

    A recent study has shown that congenitally blind adults, who have never had visual experience, are impaired on an auditory spatial bisection task (Gori, Sandini, Martinoli, & Burr, 2014). In this study we investigated how thresholds for auditory spatial bisection and auditory discrimination develop with age in sighted and congenitally blind children (9 to 14 years old). Children performed 2 spatial tasks (minimum audible angle and space bisection) and 1 temporal task (temporal bisection). There was no impairment in the temporal task for blind children but, like adults, they showed severely compromised thresholds for spatial bisection. Interestingly, the blind children also showed lower precision in judging minimum audible angle. These results confirm the adult study and go on to suggest that even simpler auditory spatial tasks are compromised in children, and that this capacity recovers over time. PMID:27228448

  11. Transient vascular compromise of the lunate after fracture-dislocation or dislocation of the carpus.

    PubMed

    White, R E; Omer, G E

    1984-03-01

    Although classic avascular necrosis of the lunate is rare after fracture-dislocation or dislocation of the carpus, these severe carpal injuries can compromise the vascular supply of the lunate. The lunate thus develops a relative increase in radiodensity. Our finding of an incidence of 12.5%--three of 24 cases--suggests a relatively frequent occurrence. The clinical course was transient with resolution of abnormal radiodensity and subjective findings. Moreover, none of the three cases progressed to classic avascular necrosis of the lunate, Kienböck's disease. The clinician should not confuse this transient vascular compromise of the lunate with Kienböck's disease, but should be aware of the entity and its benign, self-limited course and should treat it expectantly.

  12. Human Milk for Ill and Medically Compromised Infants: Strategies and Ongoing Innovation.

    PubMed

    DiLauro, Sara; Unger, Sharon; Stone, Debbie; O'Connor, Deborah L

    2016-08-01

    The use of human milk (mother's own milk and/or donor milk) in ill or medically compromised infants frequently requires some adaptation to address medical diagnoses and/or altered nutrition requirements. This tutorial describes the nutrition and immunological benefits of breast milk as well as provides evidence for the use of donor milk when mother's own milk is unavailable. Several strategies used to modify human milk to meet the medical and nutrition needs of an ill or medically compromised infant are reviewed. These strategies include (1) the standard fortification of human milk to support adequate growth, (2) the novel concept of target fortification in preterm infants, (3) instructions on how to alter maternal diet to address cow's milk protein intolerance and/or allergy in breast milk-fed infants, and (4) the removal and modification of the fat in breast milk used in infants diagnosed with chylothorax. © 2016 American Society for Parenteral and Enteral Nutrition.

  13. Genomic imprinting effects in a compromised in utero environment: implications for a healthy pregnancy.

    PubMed

    Lim, A L; Ferguson-Smith, A C

    2010-04-01

    Genomic imprinting in gametogenesis marks a subset of mammalian genes for parent-of-origin-dependent monoallelic expression in the offspring. In mice, the identification and manipulation of individual imprinted genes has shown that the diverse products of these genes are largely devoted to controlling pre- and postnatal growth. Human syndromes with parental origin effects have been characterized both at the phenotypic and genotypic levels, allowing further elucidation of the function and regulation of imprinted genes. Evidence suggests that a compromised in utero environment influences fetal growth through the modulation of epigenetic states. However it is not known whether imprinted genes, by their nature, might be more or less susceptible to such environmental influences. Here we review the progress made in addressing the influence of a compromised in utero environment on the behavior of imprinted genes. We also examine whether these environmental influences may have an impact on the later development of human disease.

  14. Evidence for altered placental blood flow and vascularity in compromised pregnancies

    PubMed Central

    Reynolds, Lawrence P; Caton, Joel S; Redmer, Dale A; Grazul-Bilska, Anna T; Vonnahme, Kimberly A; Borowicz, Pawel P; Luther, Justin S; Wallace, Jacqueline M; Wu, Guoyao; Spencer, Thomas E

    2006-01-01

    The placenta is the organ that transports nutrients, respiratory gases, and wastes between the maternal and fetal systems. Consequently, placental blood flow and vascular development are essential components of normal placental function and are critical to fetal growth and development. Normal fetal growth and development are important to ensure optimum health of offspring throughout their subsequent life course. In numerous sheep models of compromised pregnancy, in which fetal or placental growth, or both, are impaired, utero-placental blood flows are reduced. In the models that have been evaluated, placental vascular development also is altered. Recent studies found that treatments designed to increase placental blood flow can ‘rescue’ fetal growth that was reduced due to low maternal dietary intake. Placental blood flow and vascular development are thus potential therapeutic targets in compromised pregnancies. PMID:16469783

  15. A widely displaced Galeazzi-equivalent lesion with median nerve compromise.

    PubMed

    Galanopoulos, Ilias; Fogg, Quentin; Ashwood, Neil; Fu, Katherine

    2012-08-18

    We present the case of a 14-year-old boy with a right distal radial fracture accompanied by a severely displaced complete distal ulnar physeal separation and associated median nerve compromise. This injury is known as Galeazzi-equivalent lesion in children and is an extremely rare injury associated with growth arrest. Recognition of the lesion can be difficult but wide displacement may be associated with other significant injuries such as neurovascular compromise. Prompt intervention reversed the neurological symptoms. At 10-month postoperation there was neither growth arrest nor loss of motion. Complete separation of the ulna physis remains often because of soft tissue interposition or capsule problems and prompt reduction is recommended in the literature as a priority.

  16. A widely displaced Galeazzi-equivalent lesion with median nerve compromise

    PubMed Central

    Galanopoulos, Ilias; Fogg, Quentin; Ashwood, Neil; Fu, Katherine

    2012-01-01

    We present the case of a 14-year-old boy with a right distal radial fracture accompanied by a severely displaced complete distal ulnar physeal separation and associated median nerve compromise. This injury is known as Galeazzi-equivalent lesion in children and is an extremely rare injury associated with growth arrest. Recognition of the lesion can be difficult but wide displacement may be associated with other significant injuries such as neurovascular compromise. Prompt intervention reversed the neurological symptoms. At 10-month postoperation there was neither growth arrest nor loss of motion. Complete separation of the ulna physis remains often because of soft tissue interposition or capsule problems and prompt reduction is recommended in the literature as a priority. PMID:22907852

  17. Surgeon-Reported Needs for Improved Training in Identifying and Managing Free Flap Compromise.

    PubMed

    McMillan, Catherine; D'Hondt, Veerle; Marshall, Alexandra H; Binhammer, Paul; Lipa, Joan; Snell, Laura

    2017-07-01

    Background This study examined the need for improved training in the identification and management of free flap (FF) compromise and assessed a potential role for simulated scenario training. Methods Online needs assessment surveys were completed by plastic surgeons and a subsample with expertise in microsurgery education participated in focus groups. Data were analyzed using descriptive statistics and mixed qualitative methods. Results In this study, 77 surgeons completed surveys and 11 experts participated in one of two focus groups. Forty-nine (64%) participants were educators, 65 and 45% of which reported having an insufficient volume of FF cases to adequately teach the management and identification of compromise, respectively. Forty-three percent of educators felt that graduating residents are not adequately prepared to manage FF compromise independently. Exposure to normal and abnormal FF cases was felt to be critical for effective training by focus group participants. Experts identified low failure rates, communication issues, and challenging teaching conditions as current barriers to training. Most educators (74%) felt that simulated scenario training would be "very useful" or "extremely useful" to current residents. Focus groups highlighted the need for a widely accepted algorithm for re-exploration and salvage on which to base the development of a training adjunct consisting of simulated scenarios. Conclusion Trainee exposure to FF compromise is inadequate in existing plastic surgery programs. Early exposure, high case volume, and a standardized algorithmic approach to management with a focus on decision making may improve training. Simulated scenario training may be valuable in addressing current barriers. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  18. The administration of probiotics and synbiotics in immune compromised adults: is it safe?

    PubMed

    Van den Nieuwboer, M; Brummer, R J; Guarner, F; Morelli, L; Cabana, M; Claasen, E

    2015-03-01

    This study aimed to systematically evaluate safety of probiotics and synbiotics in immune compromised adults (≥18 years). Safety was analysed using the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification, thereby providing an update on previous reports using the most recent available clinical data (2008-2013). Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 57 clinical studies indicates that probiotic and/or synbiotic administration in immune compromised adults is safe with regard to the current evaluated probiotic strains, dosages and duration. Individuals were considered immune compromised if HIV-infected, critically ill, underwent surgery or had an organ- or an autoimmune disease. There were no major safety concerns in the study, as none of the serious adverse events (AE)s were related, or suspected to be related, to the probiotic or synbiotic product and the study products were well tolerated. Overall, AEs occurred less frequent in immune compromised subjects receiving probiotics and/or synbiotics compared to the control group. In addition, the results demonstrated a flaw in precise reporting and classification of AE in most studies. Furthermore, generalisability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes. We argue that standardised reporting on adverse events (CTCAE) in 'food' studies should be obligatory, thereby improving reliability of data and re-enforcing the safety profile of probiotics.

  19. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic

    PubMed Central

    Kumar, K. Pavan; Nujella, Surya Kumari; Gopal, S. Sujatha

    2016-01-01

    For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge was intact with good esthetics and no problem was reported. PMID:27195156

  20. Comparison of olestra absorption in guinea pigs with normal and compromised gastrointestinal tracts.

    PubMed

    Daher, G C; Lawson, K D; Long, P H; Tallmadge, D H; Boothe, A D; Vanderploeg, P; Miller, K W

    1997-10-01

    Female guinea pigs (12/group) were given a single dose of [14C]olestra by gavage after consuming either 3% poligeenan in tap water (Compromised group) or just tap water (Normal group) for 5 weeks. A Sentinel group (N = 2) was given 3% poligeenan for 5 weeks. Ten sentinel animals were killed 1 day before and 10 1 day after the other animals were dosed with [14C]olestra and their gastrointestinal tracts were examined by histology. The Compromised and Normal animals were endoscoped just before dosing with [14C]olestra. Urine and feces were collected continuously and CO2 was collected for 7 days after dosing. The samples were analyzed for 14C and urine was also analyzed for [14C]sucrose. Animals (3/group) were killed 1, 3, 7, and 21 days after dosing, and tissues were collected and assayed for 14C. Tissue lipids were extracted, fractionated by high-pressure liquid chromatography, and analyzed for [14C]olestra by liquid scintillation. Animals fed poligeenan showed mucosal edema, congestion, ulceration, and fibrin deposition within the distal colon and rectum. Histology revealed inflammation, epithelial degeneration, and multifocal ulceration of the cecum, distal colon, and rectum. The gastrointestinal mucosae of nonpoligeenan fed animals were normal. No [14C]olestra was detected in liver lipids and no [14C]sucrose was found in the urine for any animal in the Normal or Compromised groups, indicating that intact olestra was not absorbed. The amount, distribution, and elimination of absorbed 14C did not differ between guinea pigs with normal and compromised gastrointestinal tracts. The poligeenan-treated animals displayed mucosal damage similar to that seen in human inflammatory bowel diseases; therefore, these results suggest that patients with inflammatory bowel conditions will not absorb olestra to any greater extent than normal healthy people. Copyright 1997 Society of Toxicology.

  1. Dental implants in bilateral bifid canal and compromised interocclusal space using cone beam computerized tomography

    PubMed Central

    Ahmed, Nizar; Arunachalam, Lalitha Tanjore; Jacob, Caroline Annette; Kumar, Suresh Anand

    2016-01-01

    Knowledge of various anatomic landmarks is pivotal for important success. Bifid canals pose a challenge and can lead to difficulties while performing implant surgery in the mandible. Bifid canals can be diagnosed with panoramic radiography and more accurately with cone beam computerized tomography (CBCT). This case report details the placement of the implant in a patient with bilateral bifid canal and compromised interocclusal space, which was successfully treated using CBCT. PMID:27433073

  2. Loss of GSNOR1 Function Leads to Compromised Auxin Signaling and Polar Auxin Transport.

    PubMed

    Shi, Ya-Fei; Wang, Da-Li; Wang, Chao; Culler, Angela Hendrickson; Kreiser, Molly A; Suresh, Jayanti; Cohen, Jerry D; Pan, Jianwei; Baker, Barbara; Liu, Jian-Zhong

    2015-09-01

    Cross talk between phytohormones, nitric oxide (NO), and auxin has been implicated in the control of plant growth and development. Two recent reports indicate that NO promoted auxin signaling but inhibited auxin transport probably through S-nitrosylation. However, genetic evidence for the effect of S-nitrosylation on auxin physiology has been lacking. In this study, we used a genetic approach to understand the broader role of S-nitrosylation in auxin physiology in Arabidopsis. We compared auxin signaling and transport in Col-0 and gsnor1-3, a loss-of-function GSNOR1 mutant defective in protein de-nitrosylation. Our results showed that auxin signaling was impaired in the gsnor1-3 mutant as revealed by significantly reduced DR5-GUS/DR5-GFP accumulation and compromised degradation of AXR3NT-GUS, a useful reporter in interrogating auxin-mediated degradation of Aux/IAA by auxin receptors. In addition, polar auxin transport was compromised in gsnor1-3, which was correlated with universally reduced levels of PIN or GFP-PIN proteins in the roots of the mutant in a manner independent of transcription and 26S proteasome degradation. Our results suggest that S-nitrosylation and GSNOR1-mediated de-nitrosylation contribute to auxin physiology, and impaired auxin signaling and compromised auxin transport are responsible for the auxin-related morphological phenotypes displayed by the gsnor1-3 mutant.

  3. The appropriateness of referral of medically compromised dental patients to hospital.

    PubMed

    Absi, E G; Satterthwaite, J; Shepherd, J P; Thomas, D W

    1997-04-01

    Hospital departments of oral and maxillofacial surgery make a substantial contribution to both managing and treating medically-compromised dental patients. Contracting arrangements should take account of this. Demographic data suggest that the treatment of medically-compromised elderly dentate patients will become increasingly important in the General Dental Service (GDS). To determine the medical conditions and treatment requirements prompting referral of these patients to hospital, a prospective study was undertaken of 75 consecutive adults referred for hospital treatment specifically because of a medical condition which prevented delivery of routine dental care in the GDS. Patients (mean age: 56 years) were referred mainly from general medical (33%) and dental (62%) practitioners. Cardiovascular disease was the most frequently cited medical condition requiring referral (43%; n = 32 cases). Forty-eight patients (64%) were symptomatic on presentation and on average had attended on 2.3 occasions before definitive treatment was instituted. Fifty-two patients (70%) had no special treatment requirements other than those available in the GDS, 11 patients (15%) simply required antibiotic prophylaxis and 81% were treated by undergraduates or junior staff. These data suggest that many patients referred for dental hospital treatment because of underlying medical condition are not in fact medically-compromised and may be treated in the primary care setting.

  4. Further development of an in vitro model for studying the penetration of chemicals through compromised skin.

    PubMed

    Davies, Diane J; Heylings, Jon R; Gayes, Heather; McCarthy, Timothy J; Mack, M Catherine

    2017-02-01

    A new in vitro model based on the electrical resistance properties of the skin barrier has been established in this laboratory. The model utilises a tape stripping procedure in dermatomed pig skin that removes a specific proportion of the stratum corneum, mimicking impaired barrier function observed in humans with damaged skin. The skin penetration and distribution of chemicals with differing physicochemical properties, namely; Benzoic acid, 3-Aminophenol, Caffeine and Sucrose has been assessed in this model. Although, skin penetration over 24h differed for each chemical, compromising the skin did not alter the shape of the time course profile, although absorption into receptor fluid was higher for each chemical. Systemic exposure (receptor fluid, epidermis and dermis), was marginally higher in compromised skin following exposure to the fast penetrant, Benzoic acid, and the slow penetrant Sucrose. The systemically available dose of 3-Aminophenol increased to a greater extent and the absorption of Caffeine was more than double in compromised skin, suggesting that Molecular Weight and Log Pow, are not the only determinants for assessing systemic exposure under these conditions. Although further investigations are required, this in vitro model may be useful for prediction of dermal route exposure under conditions where skin barrier is impaired. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Pilot Analysis of Asbestos-induced Diffuse Pleural Thickening with Respiratory Compromise.

    PubMed

    Nojima, Daisuke; Fujimoto, Nobukazu; Kato, Katsuya; Fuchimoto, Yasuko; Kiura, Katsuyuki; Kishimoto, Takumi; Tanimoto, Mitsune

    2015-01-01

    We investigated the clinical features of asbestos-induced diffuse pleural thickening (DPT) with severe respiratory compromise. We conducted a retrospective study of consecutive subjects with asbestos-induced DPT. Medical data such as initial symptoms, radiological findings, respiratory function test results, and clinical course were collected and analyzed. There were 24 patients between 2003 and 2012. All were men, and the median age at the development of DPT was 74 years. The top occupational category associated with asbestos exposure was dockyard workers. The median duration of asbestos exposure was 35.0 years, and the median latency from first exposure to the onset of DPT was 49.0 years. There were no significant differences in respiratory function test results between the higher and lower Brinkman index groups or between unilateral and bilateral DPT. Thirteen patients had a history of benign asbestos pleural effusion (BAPE), and the median duration from pleural fluid accumulation to DPT with severe respiratory compromise was 28.4 months. DPT with severe respiratory compromise can develop after a long latency following occupational asbestos exposure and a history of BAPE.

  6. Methodology for determination of two new sensory thresholds: Compromised acceptance threshold and rejection threshold.

    PubMed

    Lima Filho, Tarcísio; Minim, Valéria Paula Rodrigues; Silva, Rita de Cássia Dos Santos Navarro da; Della Lucia, Suzana Maria; Minim, Luis Antônio

    2015-10-01

    The existing methodologies for determining thresholds generate unreliable estimates of the point at which the intensity of a stimulus begins to compromise acceptance or result in sensory rejection of a product. Thus, a new methodology was proposed for determination of two new sensory thresholds: the compromised acceptance threshold (CAT) and the rejection threshold (RT). In this new methodology, increasing or decreasing series of stimulus intensity are measured together with a standard stimulus (control sample) by means of acceptance tests. In the present study, the CAT and RT were determined for sucrose concentrations in grape nectar, demonstrating that when reducing the sucrose concentration of grape nectar form 9.00% (w/v) to 6.87% there begins to occur impairment of product acceptance (CAT), and when reducing the sucrose concentration from 9.00% to 3.83% there begins to occur sensory rejection (RT) of the product. When compared to existing threshold determination methodologies, the proposed methodology permitted for calculating, with greater reliability, the points at which compromise of acceptance (CAT) and sensory rejection (RT) of the product begin to occur. In addition to the case study presented, the proposed methodology has a wide range of applications in science and in the food, cosmetic and pharmaceutical industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Autobiographical memory compromise in individuals with alcohol use disorders: Towards implications for psychotherapy research.

    PubMed

    Nandrino, Jean-Louis; Gandolphe, Marie-Charlotte; El Haj, Mohamad

    2017-10-01

    It has been found that Autobiographical memory (i.e., memory for personal experiences and facts about the self) are not properly maintained in people with alcohol-use disorders (AUD). The present paper offers a comprehensive overview of findings regarding the consequences of AUD on autobiographical memory. More specifically, we offer a theoretical model (the AMAUD Autobiographical Memory and Alcohol Use Disorders model) according to which chronic alcohol consumption compromises emotion regulation as well as executive control, which maintains the construction of autobiographical memory. Compromises in emotional regulation and executive functioning can be linked to a weak aspiration to construct detailed memories (i.e., autobiographical overgenerality), compromises of subjective reliving, anterograde amnesia, negative self-defining memories, and a difficulty to mentally project oneself forward in time to generate complex autobiographical representations and self-images. By gathering cognitive and clinical aspects of autobiographical decline in AUD, this model constitutes a theoretical foundation that may lead to a better understanding of this decline. Different clinical perspectives are proposed for developing personalized autobiographical memory rehabilitation programs for individuals with AUD. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Lysosomal compromise and brain dysfunction: examining the role of neuroaxonal dystrophy.

    PubMed

    Walkley, Steven U; Sikora, Jakub; Micsenyi, Matthew; Davidson, Cristin; Dobrenis, Kostantin

    2010-12-01

    Lysosomal diseases are a family of over 50 disorders caused by defects in proteins critical for normal function of the endosomal/lysosomal system and characterized by complex pathogenic cascades involving progressive dysfunction of many organ systems, most notably the brain. Evidence suggests that compromise in lysosomal function is highly varied and leads to changes in multiple substrate processing and endosomal signalling, in calcium homoeostasis and endoplasmic reticulum stress, and in autophagocytosis and proteasome function. Neurons are highly vulnerable and show abnormalities in perikarya, dendrites and axons, often in ways seemingly unrelated to the primary lysosomal defect. A notable example is NAD (neuroaxonal dystrophy), which is characterized by formation of focal enlargements (spheroids) containing diverse organelles and other components consistent with compromise of retrograde axonal transport. Although neurons may be universally susceptible to NAD, GABAergic neurons, particularly Purkinje cells, appear most vulnerable and ataxia and related features of cerebellar dysfunction are a common outcome. As NAD is found early in disease and thus may be a contributor to Purkinje cell dysfunction and death, understanding its link to lysosomal compromise could lead to therapies designed to prevent its occurrence and thereby ameliorate cerebellar dysfunction.

  9. Lysosomal Compromise and Brain Dysfunction: Examining the Role of Neuroaxonal Dystrophy

    PubMed Central

    Walkley, Steven U.; Sikora, Jakub; Micsenyi, Matthew; Davidson, Cristin; Dobrenis, Kostantin

    2015-01-01

    Lysosomal diseases are a family of over 50 disorders caused by defects in proteins critical for normal function of the endosomal/lysosomal system and characterized by complex pathogenic cascades involving progressive dysfunction of many organ systems, most notably brain. Evidence suggests that compromise in lysosomal function is highly varied and leads to changes in multiple substrate processing and endosomal signaling, in calcium homeostasis and ER stress, and in autophagocytosis and proteasome function. Neurons are highly vulnerable and show abnormalities in perikarya, dendrites, and axons, often in ways appearing unrelated to the primary lysosomal defect. A notable example is neuroaxonal dystrophy (NAD) which is characterized by formation of focal enlargements (spheroids) containing diverse organelles and other components consistent with compromise of retrograde axonal transport. While neurons may be universally susceptible to NAD, GABAergic neurons, particularly Purkinje cells, appear most vulnerable and ataxia and related features of cerebellar dysfunction are a common outcome. As NAD is found early in disease and thus may be a contributor to Purkinje cell dysfunction and death, understanding its link to lysosomal compromise could lead to therapies designed to prevent its occurrence and thereby ameliorate cerebellar dysfunction. PMID:21118103

  10. Indications and contraindications of dental implants in medically compromised patients: Update

    PubMed Central

    Gómez-de Diego, Rafael; Mang-de la Rosa, María del Rocío; Romero-Pérez, María J.; Cutando-Soriano, Antonio

    2014-01-01

    The aim of this study was to review the current scientific literature in order to analyse the indications and contraindications of dental implants in medically compromised patients. A reference research was carried out on PubMed using the key words “implant” AND (oral OR dental) AND (systemic disease OR medically compromised), in articles published between 1993 and 2013. The inclusion criteria were the following: clinical studies in which, at least, 10 patients were treated, consensus articles, reviewed articles and meta-analysis performed in humans treated with dental implants, and which included the disease diagnosis. A total of 64 articles were found, from which 16 met the inclusion criteria. Cardiac systemic diseases, diabetic endocrine pathologies or controlled metabolic disorders do not seem to be a total or partial contraindication to the placement of dental implants. Tobacco addiction, and head and neck radiotherapy are correlated to a higher loss of dental implants. Patients suffering from osteoporosis undergoing biphosphonates therapy show an increased risk of developing bone necrosis after an oral surgery, especially if the drugs are administered intravenously or they are associated to certain concomitant medication. Key words:Dental implants, medically compromised patient, systemic diseases. PMID:24608222

  11. Normal and Malignant Muscle Cell Transplantation into Immune Compromised Adult Zebrafish

    PubMed Central

    Moore, John C.; Langenau, David M.

    2014-01-01

    Zebrafish have become a powerful tool for assessing development, regeneration, and cancer. More recently, allograft cell transplantation protocols have been developed that permit engraftment of normal and malignant cells into irradiated, syngeneic, and immune compromised adult zebrafish. These models when coupled with optimized cell transplantation protocols allow for the rapid assessment of stem cell function, regeneration following injury, and cancer. Here, we present a method for cell transplantation of zebrafish adult skeletal muscle and embryonal rhabdomyosarcoma (ERMS), a pediatric sarcoma that shares features with embryonic muscle, into immune compromised adult rag2E450fs homozygous mutant zebrafish. Importantly, these animals lack T cells and have reduced B cell function, facilitating engraftment of a wide range of tissues from unrelated donor animals. Our optimized protocols show that fluorescently labeled muscle cell preparations from α-actin-RFP transgenic zebrafish engraft robustly when implanted into the dorsal musculature of rag2 homozygous mutant fish. We also demonstrate engraftment of fluorescent-transgenic ERMS where fluorescence is confined to cells based on differentiation status. Specifically, ERMS were created in AB-strain myf5-GFP; mylpfa-mCherry double transgenic animals and tumors injected into the peritoneum of adult immune compromised fish. The utility of these protocols extends to engraftment of a wide range of normal and malignant donor cells that can be implanted into dorsal musculature or peritoneum of adult zebrafish. PMID:25591079

  12. Live Attenuated S. Typhimurium Vaccine with Improved Safety in Immuno-Compromised Mice

    PubMed Central

    Periaswamy, Balamurugan; Maier, Lisa; Vishwakarma, Vikalp; Slack, Emma; Kremer, Marcus; Andrews-Polymenis, Helene L.; McClelland, Michael; Grant, Andrew J.; Suar, Mrutyunjay; Hardt, Wolf-Dietrich

    2012-01-01

    Live attenuated vaccines are of great value for preventing infectious diseases. They represent a delicate compromise between sufficient colonization-mediated adaptive immunity and minimizing the risk for infection by the vaccine strain itself. Immune defects can predispose to vaccine strain infections. It has remained unclear whether vaccine safety could be improved via mutations attenuating a vaccine in immune-deficient individuals without compromising the vaccine's performance in the normal host. We have addressed this hypothesis using a mouse model for Salmonella diarrhea and a live attenuated Salmonella Typhimurium strain (ssaV). Vaccination with this strain elicited protective immunity in wild type mice, but a fatal systemic infection in immune-deficient cybb−/−nos2−/− animals lacking NADPH oxidase and inducible NO synthase. In cybb−/−nos2−/− mice, we analyzed the attenuation of 35 ssaV strains carrying one additional mutation each. One strain, Z234 (ssaV SL1344_3093), was >1000-fold attenuated in cybb−/−nos2−/− mice and ≈100 fold attenuated in tnfr1−/− animals. However, in wt mice, Z234 was as efficient as ssaV with respect to host colonization and the elicitation of a protective, O-antigen specific mucosal secretory IgA (sIgA) response. These data suggest that it is possible to engineer live attenuated vaccines which are specifically attenuated in immuno-compromised hosts. This might help to improve vaccine safety. PMID:23029007

  13. Risky Driving, Mental Health, and Health-Compromising Behaviors: Risk Clustering in Late Adolescents and Adults

    PubMed Central

    Sommers, Marilyn S.; Fargo, Jamison D.

    2014-01-01

    Background Health-compromising behaviors in adolescents and adults co-occur. Because motor vehicle crashes are the leading cause of death and disability for these age groups, understanding the association between risky driving and other health compromising behaviors is critical. Methods We performed a secondary analysis of data from a randomized controlled trial of an intervention for participants who screened positive for risky driving and problem drinking. Using baseline data, we examined relationships among conduct behavior problems before and after age 15, depressive symptoms, sleep, problem drinking, and risky driving (hostile, reckless and drinking and driving) in late adolescents ages 18–24 (n= 110) and adults ages 25–44 (n= 202). We developed a measurement model for the entire sample using confirmatory factor analysis, which was then specified as a multi-group structural equation model. Results Late adolescents and adults had some similar associations for pathways through problem drinking to drinking and driving; depression to reckless driving; and conduct behavior problems after 15 to hostile driving. Late adolescents, however, had more complex relationships: depressive symptoms and conduct behavior problems before 15 were associated with more risky driving behaviors through multiple pathways and males reported more risky driving. Conclusions Risky driving is associated with other health-compromising behaviors and mental health factors. It is a multidimensional phenomenon more pronounced in late adolescence than adulthood. In order to promote safe driving, the findings support the need to consider behaviors that are a health threat in the late adolescent population during driving training and licensure. PMID:24814717

  14. Risky driving, mental health, and health-compromising behaviours: risk clustering in late adolescents and adults.

    PubMed

    McDonald, Catherine C; Sommers, Marilyn S; Fargo, Jamison D

    2014-12-01

    Health-compromising behaviours in adolescents and adults co-occur. Because motor vehicle crashes are the leading cause of death and disability for these age groups, understanding the association between risky driving and other health-compromising behaviours is critical. We performed a secondary analysis of data from a randomised controlled trial of an intervention for participants who screened positive for risky driving and problem drinking. Using baseline data, we examined relationships among conduct behaviour problems before and after age 15 years, depressive symptoms, sleep, problem drinking, and risky driving (hostile, reckless and drinking and driving) in late adolescents ages 18-24 (n=110) years, and adults ages 25-44 (n=202) years. We developed a measurement model for the entire sample using confirmatory factor analysis, which was then specified as a multigroup structural equation model. Late adolescents and adults had some similar associations for pathways through problem drinking to drinking and driving; depression to reckless driving; and conduct behaviour problems after 15 years of age to hostile driving. Late adolescents, however, had more complex relationships: depressive symptoms and conduct behaviour problems before 15 years of age were associated with more risky driving behaviours through multiple pathways, and males reported more risky driving. Risky driving is associated with other health-compromising behaviours and mental health factors. It is a multidimensional phenomenon more pronounced in late adolescence than adulthood. In order to promote safe driving, the findings support the need to consider behaviours that are a health threat in the late adolescent population during driving training and licensure. NCT00164294. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Arsenic promotes centrosome abnormalities and cell colony formation in p53 compromised human lung cells

    SciTech Connect

    Liao Weiting; Lin Pinpin; Cheng, T.-S.; Yu, H.-S.; Chang, Louis W.

    2007-12-01

    Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus, an interaction between arsenic and cigarette smoking in lung carcinogenesis was suspected. p53 dysfunction or mutation in lung epithelial cells was frequently observed in cigarette smokers. Our present study was to explore the differential effects by arsenic on H1355 cells (human lung adenocarcinoma cell line with mutation in p53), BEAS-2B (immortalized lung epithelial cell with functional p53) and pifithrin-{alpha}-treated BEAS-2B cells (p53-inhibited cells). These cells were treated with different doses of sodium arsenite (0, 0.1, 1, 5 and 10 {mu}M) for 48 h. A greater reduction in cell viability was observed in the BEAS-2B cells vs. p53 compromised cells (H1355 or p53-inhibited BEAS-2B). Similar observation was also made on 7-day cell survival (growth) study. TUNEL analysis confirmed that there was indeed a significantly reduced arsenite-induced apoptosis found in p53-compromised cells. Centrosomal abnormality has been attributed to eventual chromosomal missegregation, aneuploidy and tumorigenesis. In our present study, reduced p21 and Gadd45a expressions and increased centrosomal abnormality (atopic and multiple centrosomes) were observed in both arsenite-treated H1355 and p53-inhibited BEAS-2B cells as compared with similarly treated BEAS-2B cells. Increased anchorage-independent growth (colony formation) of BEAS-2B cells co-treated with pifithrin-{alpha} and 5 {mu}M sodium arsenite was also observed in soft agar. Our present investigation demonstrated that arsenic would act specifically on p53 compromised cells (either with p53 dysfunction or inhibited) to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenic, especially under the condition of p53 dysfunction.

  16. Compromised Bone Microarchitecture and Estimated Bone Strength in Young Adults With Cystic Fibrosis

    PubMed Central

    Milliren, Carly E.; Derrico, Nicholas; Uluer, Ahmet; Sicilian, Leonard; Lapey, Allen; Sawicki, Gregory; Gordon, Catherine M.; Bouxsein, Mary L.; Finkelstein, Joel S.

    2014-01-01

    Context: Young adults with cystic fibrosis (CF) are at risk for low bone density and fractures, but the underlying alterations in bone microarchitecture that may contribute to their increased fracture risk are currently unknown. Objective: The main goal of this study was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) to characterize the bone microarchitecture, volumetric bone mineral density (vBMD), and estimated strength of the radius and tibia in young adults with CF compared with healthy volunteers. Design and Setting: This was a cross-sectional study at an outpatient clinical research center within a tertiary academic medical center. Participants: Thirty young adults with CF, 18 to 40 years of age, were evaluated and compared with 60 healthy volunteers matched by age (±2 years), gender, and race. Main Outcome Measures: The primary outcomes were HR-pQCT–derived cortical and trabecular vBMD, bone microarchitecture, and estimates of bone strength. Results: At the radius and tibia, young adults with CF had smaller bone cross-sectional area and lower vBMD. Cortical and trabecular microarchitecture were compromised at both sites, most notably involving the trabecular bone of the tibia. These differences translated into lower estimated bone strength both at the radius and tibia. After accounting for body mass index differences, young adults with CF had lower bone area and estimated bone strength at the radius and had compromised trabecular microarchitecture and lower total and trabecular vBMD and estimated bone strength at the tibia. Alterations in trabecular bone density and microarchitecture and estimated strength measures of the tibia were also greater than expected based on dual-energy x-ray absorptiometry-derived areal BMD differences. Conclusions: Young adults with CF have compromised bone microarchitecture and lower estimated bone strength at both the radius and tibia, even after accounting for their smaller body size. These

  17. Clinical Outcomes of Osseointegrated Prosthetic Auricular Reconstruction in Patients With a Compromised Ipsilateral Temporoparietal Fascial Flap.

    PubMed

    Zuo, Kevin J; Wilkes, Gordon H

    2016-01-01

    Patients with major ear deformities and associated compromise of the superficial temporal artery are poor candidates for autogenous ear reconstruction because of a tenuous ipsilateral temporoparietal fascial flap (TPFF). Osseointegrated prosthetic auricular reconstruction (OPAR) is an alternative to contralateral free TPFF microsurgical and autogenous reconstruction, but data on clinical outcomes are limited. The records of patients with ear loss or major deformity and a compromised ipsilateral TPFF who underwent OPAR from 1989 to 2013 were reviewed. Satisfaction was assessed using a questionnaire based on a 5 point Likert scale. Thirty-two patients (8 women, 24 men) with mean age 43.0 years (range, 10-70 years) underwent OPAR. The ipsilateral TPFF was compromised due to major trauma (13 patients), cancer extirpation (9), burn injury (4), previous harvest (4), arteriovenous malformation (1), or infection (1). All but 2 patients had an associated craniofacial defect, such as soft tissue deformity (87.5%), hearing loss (46.9%), or bony deformity (31.3%). The overall implant success rate was 88.6% at mean follow-up time of 7.6 years post-OPAR. Prosthesis wear averaged 12.2 hours/day and 6.6 days/week (80.5 hours/week). All 5 patients who experienced implant failures had received prior head and neck irradiation. With their prosthesis, 76.2% (16 patients) stated that their self-consciousness and self-esteem were "better" or "much better," whereas 85.7% (18 patients) stated that their self-image was "better" or "much better." All patients declared that they would undergo the treatment again. Osseointegrated prosthetic auricular reconstruction is a reliable option in this challenging population with high patient satisfaction. Patients with prior radiotherapy may have a higher chance of implant failure and would benefit from extended annual follow-up.

  18. Compromised bone microarchitecture and estimated bone strength in young adults with cystic fibrosis.

    PubMed

    Putman, Melissa S; Milliren, Carly E; Derrico, Nicholas; Uluer, Ahmet; Sicilian, Leonard; Lapey, Allen; Sawicki, Gregory; Gordon, Catherine M; Bouxsein, Mary L; Finkelstein, Joel S

    2014-09-01

    Young adults with cystic fibrosis (CF) are at risk for low bone density and fractures, but the underlying alterations in bone microarchitecture that may contribute to their increased fracture risk are currently unknown. The main goal of this study was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) to characterize the bone microarchitecture, volumetric bone mineral density (vBMD), and estimated strength of the radius and tibia in young adults with CF compared with healthy volunteers. This was a cross-sectional study at an outpatient clinical research center within a tertiary academic medical center. Thirty young adults with CF, 18 to 40 years of age, were evaluated and compared with 60 healthy volunteers matched by age (±2 years), gender, and race. The primary outcomes were HR-pQCT-derived cortical and trabecular vBMD, bone microarchitecture, and estimates of bone strength. At the radius and tibia, young adults with CF had smaller bone cross-sectional area and lower vBMD. Cortical and trabecular microarchitecture were compromised at both sites, most notably involving the trabecular bone of the tibia. These differences translated into lower estimated bone strength both at the radius and tibia. After accounting for body mass index differences, young adults with CF had lower bone area and estimated bone strength at the radius and had compromised trabecular microarchitecture and lower total and trabecular vBMD and estimated bone strength at the tibia. Alterations in trabecular bone density and microarchitecture and estimated strength measures of the tibia were also greater than expected based on dual-energy x-ray absorptiometry-derived areal BMD differences. Young adults with CF have compromised bone microarchitecture and lower estimated bone strength at both the radius and tibia, even after accounting for their smaller body size. These skeletal deficits likely explain the higher fracture risk observed in young adults with CF.

  19. Results of endoscopic surgery and intralesional steroid therapy for airway compromise due to tracheobronchial Wegener's granulomatosis.

    PubMed

    Nouraei, S A R; Obholzer, R; Ind, P W; Salama, A D; Pusey, C D; Porter, F; Howard, D J; Sandhu, G S

    2008-01-01

    Upper airway compromise due to tracheobronchial stenosis commonly occurs in patients with Wegener's granulomatosis (WG). There is at present no consensus on the optimal management of this life threatening condition. To assess the results of laryngo-tracheo-bronchoscopy, intralesional steroid therapy, laser surgery and dilatation in managing obstructive tracheobronchial WG. Records of 18 previously untreated stridulous patients with obstructive tracheobronchial WG, treated between 2004 and 2006, were prospectively recorded on an airway database and retrospectively reviewed. Information about patient and lesion characteristics and treatment details were recorded. Treatment progress was illustrated using a timeline plot, and intervention-free intervals were calculated with actuarial analysis. There were nine males and the average age at presentation was 40 (16) years (range 13-74). There were 13 patients with tracheal and five with tracheal and bronchial lesions. The average tracheal lesion height was 8 (3) mm, located 23 (9) mm below the glottis. There were 1, 10 and 7 Myer-Cotton grade I, II and III lesions, respectively. Mean intervention-free interval following minimally invasive treatment was 26 (2.8) months. Following endobronchial therapy, the median intervention-free interval was 22 months (p>0.8 vs tracheal lesions). No patient required a tracheostomy or endoluminal stenting. Intralesional steroid therapy and conservative endoluminal surgery is an effective strategy for treating airway compromise due to active tracheal and bronchial WG, obviating the need for airway bypass or stenting. We recommend the combination of endotracheal dilatation, conservative laser surgery and steroid therapy as the standard of care for treating airway compromise due to obstructive tracheobronchial WG.

  20. Neogene and Quaternary coexisting in the geological time scale: The inclusive compromise

    NASA Astrophysics Data System (ADS)

    McGowran, Brian; Berggren, Bill; Hilgen, Frits; Steininger, Fritz; Aubry, Marie-Pierre; Lourens, Lucas; Van Couvering, John

    2009-11-01

    Removing the Tertiary and Quaternary Periods whilst conserving the Paleogene and Neogene Periods in The Geological Timescale 2004 caused a storm of protest. One response was to advocate restoring an enlarged Quaternary and consigning the Neogene to a minor role within the Tertiary. Amongst an array of practical, traditional, sentimental and anthropocentric reasons for this response, the one hard-core justification was that the rigidly nested hierarchy of the geological timescale must be preserved. The central objective of this paper is conserving the historically legitimate, Miocene-present, Neogene Period and System. There are two options for conserving the Quaternary concurrently with the Neogene: (i) an inclusive compromise in a flexible hierarchy, and (ii) an upgrading of Pliocene and Pleistocene divisions to the level of epoch. In the inclusive compromise there coexist alternative pathways through the hierarchical ranks. Thus geohistorians and biohistorians have two options for traversing the hierarchy from era to age, as in this example using the hierarchical positioning of the Calabrian Age and Stage: either Cenozoic [era]↔Neogene [period]↔Pleistocene [epoch]↔Calabrian [age], or Cenozoic [era]↔Quaternary [subera]↔Pleistocene [epoch]↔Calabrian [age]. We reaffirm that the inclusive compromise is entirely viable. In so doing we (i) challenge the necessity of the rigidly nested hierarchy, which should be capable of a little flexibility; (ii) reject all analogies of the arbitrary and conventional chronostratigraphic hierarchy with three natural biological hierarchies; (iii) reaffirm the integrity of the Neogene extending to the present; and (iv) see no reason to doubt the harmonious coexistence of the two options preserving the Quaternary and Neogene traditions in an orderly working and stable time scale. In the alternative schema conserving the Neogene, divisions of the Pliocene and Pleistocene are upgraded, so that the Late Pleistocene, Early

  1. Compromise of Multiple Time-Resolved Transcriptomics Experiments Identifies Tightly Regulated Functions

    PubMed Central

    Klie, Sebastian; Caldana, Camila; Nikoloski, Zoran

    2012-01-01

    With the advent of high-throughput technologies for data acquisition from different components (i.e., genes, proteins, and metabolites) of a given biological system, generation of hypotheses, and biological interpretations based on multivariate data sets become increasingly important. These technologies allow for simultaneous gathering of data from the same biological components under different perturbations, including genotypic variation and/or changes in conditions, resulting in so-called multiple data tables. Moreover, these data tables are obtained over a well-chosen time domain to capture the dynamics of the response of the biological system to the perturbation. The computational problem we address in this study is twofold: (1) derive a single data table, referred to as a compromise, which captures information common to the investigated set of multiple tables and (2) identify biological components which contribute most to the determined compromise. Here we argue that recent extensions to principle component analysis called STATIS and dual-STATIS can be used to determine the compromise on which classical techniques for data analysis, such as clustering and term over-enrichment, can be subsequently applied. In addition, we illustrate that STATIS and dual-STATIS facilitate interpretations of a publically available transcriptomics data set capturing the time-resolved response of Arabidopsis thaliana to changing light and/or temperature conditions. We demonstrate that STATIS and dual-STATIS can be used not only to identify the components of a biological system whose behavior is similarly affected due to the perturbation (e.g., in time or condition), but also to specify the extent to which each dimension of the data tables reflect the perturbation. These findings ultimately provide insights in the components and pathways which could be under tight control in plant systems. PMID:23162561

  2. Identifying compromised systems through correlation of suspicious traffic from malware behavioral analysis

    NASA Astrophysics Data System (ADS)

    Camilo, Ana E. F.; Grégio, André; Santos, Rafael D. C.

    2016-05-01

    Malware detection may be accomplished through the analysis of their infection behavior. To do so, dynamic analysis systems run malware samples and extract their operating system activities and network traffic. This traffic may represent malware accessing external systems, either to steal sensitive data from victims or to fetch other malicious artifacts (configuration files, additional modules, commands). In this work, we propose the use of visualization as a tool to identify compromised systems based on correlating malware communications in the form of graphs and finding isomorphisms between them. We produced graphs from over 6 thousand distinct network traffic files captured during malware execution and analyzed the existing relationships among malware samples and IP addresses.

  3. Chronic Lymphocytic Leukemia as an Unusual Cause of Rapid Airway Compromise

    PubMed Central

    Ezzell, Erin E.; Renshaw, John S.

    2017-01-01

    Chronic Lymphocytic Leukemia (CLL) is the most prevalent form of non-Hodgkin's lymphoma (NHL) in Western countries predominantly affecting adults over the age of 65. CLL is commonly indolent in nature but can present locally and aggressively at extranodal sites. Although CLL may commonly present with cervical lymphadenopathy, manifestation in nonlymphoid regions of the head and neck is not well described. CLL causing upper airway obstruction is even more uncommon. We describe a case of a patient with known history of CLL and stable lymphocytosis that developed an enlarging lymphoid base of tongue (BOT) mass resulting in rapid airway compromise. PMID:28396813

  4. Federal Claims Collection Act; claims collection and compromise--HCFA. Final rule with comment period.

    PubMed

    1983-08-29

    These regulations implement the Federal Claims Collection Act, which provides authority to Federal agencies for collecting or compromising claims, or suspending or terminating collection action, as appropriate. This authority can be exercised only through agency regulations that conform to the regulations on claims collection (4 CFR Parts 101-105) issued jointly by the Comptroller General and the Attorney General. We intend these regulations to enable HCF to exercise full claims collection authority for all HCF programs, as delegated by the Secretary of HHS.

  5. Immediate Implant Loading in Compromised Maxillary Partially Edentulous Arch- A Case Report

    PubMed Central

    Ramesh, Sachhi; Patil, Veena; Jain, Anoop; Gaddale, Reetika

    2014-01-01

    As the aesthetic demands are increasing day by day, demand of immediate restoration or replacement of teeth is also increasing. Because of this, immediate implant placement, along with immediate loading of implant, is a favourite treatment option for patients as well as dentists. This case report discusses the immediate implant loading in compromised maxillary anterior region, in which patient got immediate restoration of edentulous area. More importantly, from the patients’ points of view, immediate loading can produce positive social and psychological effects. PMID:24959519

  6. Civil capacity in transition-age youth with history of central nervous system compromise: a review.

    PubMed

    Donders, Jacobus

    2017-04-01

    The purpose of this paper is to review various aspects of decision-making capacities in children and adolescents with a history of central nervous system compromise over the course of development and into transition to adulthood. The literature on consent capacity in various domains is reviewed, with reference to state-specific legal definitions and requirements, and illustrated with a case example. Neuropsychologists who use an evidence-based assessment approach, and who can clearly communicate their findings in reference to specific probate court standards, can make a unique contribution to the legal system while serving their clients who are transitioning from adolescence into adulthood.

  7. Does a living will equal a DNR? Are living wills compromising patient safety?

    PubMed

    Mirarchi, Ferdinando L

    2007-10-01

    Living wills are thought to protect the medical decision-making capacity of patients. Presented are three case scenarios of patients with living wills presenting to health care facilities for treatment, and their hospital courses. Living wills have never been thought to compromise patient care or safety, but their use has not been adequately studied with respect to risks, benefits, or consequences. This case series will define a scenario as well as how that scenario was affected by the presence of a living will. In addition, existing data regarding the care provided to patients with a code status designation of DNR (do not resuscitate) are reviewed.

  8. Demographic corrections appear to compromise classification accuracy for severely skewed cognitive tests.

    PubMed

    O'Connell, Megan E; Tuokko, Holly; Kadlec, Helena

    2011-04-01

    Demographic corrections for cognitive tests should improve classification accuracy by reducing age or education biases, but empirical support has been equivocal. Using a simulation procedure, we show that creating moderate or extreme skewness in cognitive tests compromises the classification accuracy of demographic corrections, findings that appear replicated within clinical data for the few neuropsychological test scores with an extreme degree of skew. For most neuropsychological tests, the dementia classification accuracy of raw and demographically corrected scores was equivalent. These findings suggest that the dementia classification accuracy of demographic corrections is robust to slight degrees of skew (i.e., skewness <1.5).

  9. Indications and contraindications of dental implants in medically compromised patients: update.

    PubMed

    Gómez-de Diego, Rafael; Mang-de la Rosa, María del Rocío; Romero-Pérez, María-Jesús; Cutando-Soriano, Antonio; López-Valverde-Centeno, Antonio

    2014-09-01

    The aim of this study was to review the current scientific literature in order to analyse the indications and contraindications of dental implants in medically compromised patients. A reference research was carried out on PubMed using the key words "implant" AND (oral OR dental) AND (systemic disease OR medically compromised), in articles published between 1993 and 2013. The inclusion criteria were the following: clinical studies in which, at least, 10 patients were treated, consensus articles, reviewed articles and meta-analysis performed in humans treated with dental implants, and which included the disease diagnosis. A total of 64 articles were found, from which 16 met the inclusion criteria. Cardiac systemic diseases, diabetic endocrine pathologies or controlled metabolic disorders do not seem to be a total or partial contraindication to the placement of dental implants. Tobacco addiction, and head and neck radiotherapy are correlated to a higher loss of dental implants. Patients suffering from osteoporosis undergoing biphosphonates therapy show an increased risk of developing bone necrosis after an oral surgery, especially if the drugs are administered intravenously or they are associated to certain concomitant medication.

  10. Can Neglected Tropical Diseases Compromise Human Wellbeing in Sex-, Age-, and Trait-Specific Ways?

    PubMed Central

    Geary, David C.

    2016-01-01

    Traits that facilitate competition for reproductive resources or that influence mate choice have evolved to signal resilience to infectious disease and other stressors. As a result, the dynamics of competition and choice can, in theory, be used to generate predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species, including humans. These dynamics and associated vulnerabilities are reviewed for nonhuman species, focusing on traits that are compromised by exposure to parasites. Using the same approach, sex-, age-, and trait-specific vulnerabilities to parasitic disease are illustrated for children’s and adolescent’s physical growth and fitness. Suggestions are then provided for widening the assessment of human vulnerabilities to include age-appropriate measures of behavioral (e.g., children’s play) and cognitive (e.g., language fluency) traits. These are traits that are likely to be compromised by infection in age- and sex-specific ways. Inclusion of these types of measures in studies of neglected tropic diseases has the potential to provide a more nuanced understanding of how these diseases undermine human wellbeing and may provide a useful means to study the efficacy of associated treatments. PMID:27077746

  11. Hydraulic efficiency compromises compression strength perpendicular to the grain in Norway spruce trunkwood

    PubMed Central

    2011-01-01

    The aim of this study was to investigate bending stiffness and compression strength perpendicular to the grain of Norway spruce (Picea abies (L.) Karst.) trunkwood with different anatomical and hydraulic properties. Hydraulically less safe mature sapwood had bigger hydraulic lumen diameters and higher specific hydraulic conductivities than hydraulically safer juvenile wood. Bending stiffness (MOE) was higher, whereas radial compression strength lower in mature than in juvenile wood. A density-based tradeoff between MOE and hydraulic efficiency was apparent in mature wood only. Across cambial age, bending stiffness did not compromise hydraulic efficiency due to variation in latewood percent and because of the structural demands of the tree top (e.g. high flexibility). Radial compression strength compromised, however, hydraulic efficiency because it was extremely dependent on the characteristics of the “weakest” wood part, the highly conductive earlywood. An increase in conduit wall reinforcement of earlywood tracheids would be too costly for the tree. Increasing radial compression strength by modification of microfibril angles or ray cell number could result in a decrease of MOE, which would negatively affect the trunk’s capability to support the crown. We propose that radial compression strength could be an easily assessable and highly predictive parameter for the resistance against implosion or vulnerability to cavitation across conifer species, which should be topic of further studies. PMID:22058609

  12. Metabolic engineering of lipid catabolism increases microalgal lipid accumulation without compromising growth

    PubMed Central

    Trentacoste, Emily M.; Shrestha, Roshan P.; Smith, Sarah R.; Glé, Corine; Hartmann, Aaron C.; Hildebrand, Mark; Gerwick, William H.

    2013-01-01

    Biologically derived fuels are viable alternatives to traditional fossil fuels, and microalgae are a particularly promising source, but improvements are required throughout the production process to increase productivity and reduce cost. Metabolic engineering to increase yields of biofuel-relevant lipids in these organisms without compromising growth is an important aspect of advancing economic feasibility. We report that the targeted knockdown of a multifunctional lipase/phospholipase/acyltransferase increased lipid yields without affecting growth in the diatom Thalassiosira pseudonana. Antisense-expressing knockdown strains 1A6 and 1B1 exhibited wild-type–like growth and increased lipid content under both continuous light and alternating light/dark conditions. Strains 1A6 and 1B1, respectively, contained 2.4- and 3.3-fold higher lipid content than wild-type during exponential growth, and 4.1- and 3.2-fold higher lipid content than wild-type after 40 h of silicon starvation. Analyses of fatty acids, lipid classes, and membrane stability in the transgenic strains suggest a role for this enzyme in membrane lipid turnover and lipid homeostasis. These results demonstrate that targeted metabolic manipulations can be used to increase lipid accumulation in eukaryotic microalgae without compromising growth. PMID:24248374

  13. DMP-1-mediated Ghr gene recombination compromises skeletal development and impairs skeletal response to intermittent PTH

    PubMed Central

    Liu, Zhongbo; Kennedy, Oran D.; Cardoso, Luis; Basta-Pljakic, Jelena; Partridge, Nicola C.; Schaffler, Mitchell B.; Rosen, Clifford J.; Yakar, Shoshana

    2016-01-01

    Bone minerals are acquired during growth and are key determinants of adult skeletal health. During puberty, the serum levels of growth hormone (GH) and its downstream effector IGF-1 increase and play critical roles in bone acquisition. The goal of the current study was to determine how bone cells integrate signals from the GH/IGF-1 to enhance skeletal mineralization and strength during pubertal growth. Osteocytes, the most abundant bone cells, were shown to orchestrate bone modeling during growth. We used dentin matrix protein (Dmp)-1-mediated Ghr knockout (DMP-GHRKO) mice to address the role of the GH/IGF axis in osteocytes. We found that DMP-GHRKO did not affect linear growth but compromised overall bone accrual. DMP-GHRKO mice exhibited reduced serum inorganic phosphate and parathyroid hormone (PTH) levels and decreased bone formation indices and were associated with an impaired response to intermittent PTH treatment. Using an osteocyte-like cell line along with in vivo studies, we found that PTH sensitized the response of bone to GH by increasing Janus kinase-2 and IGF-1R protein levels. We concluded that endogenously secreted PTH and GHR signaling in bone are necessary to establish radial bone growth and optimize mineral acquisition during growth.—Liu, Z., Kennedy, O. D., Cardoso, L., Basta-Pljakic, J., Partridge, N. C., Schaffler, M. B., Rosen, C. J., Yakar, S. DMP-1-mediated Ghr gene recombination compromises skeletal development and impairs skeletal response to intermittent PTH. PMID:26481310

  14. Focal cartilage defect compromises fluid-pressure dependent load support in the knee joint.

    PubMed

    Dabiri, Yaghoub; Li, LePing

    2015-06-01

    A focal cartilage defect involves tissue loss or rupture. Altered mechanics in the affected joint may play an essential role in the onset and progression of osteoarthritis. The objective of the present study was to determine the compromised load support in the human knee joint during defect progression from the cartilage surface to the cartilage-bone interface. Ten normal and defect cases were simulated with a previously tested 3D finite element model of the knee. The focal defects were considered in both condyles within high load-bearing regions. Fluid pressurization, anisotropic fibril-reinforcement, and depth-dependent mechanical properties were considered for the articular cartilages and menisci. The results showed that a small cartilage defect could cause 25% reduction in the load support of the knee joint due to a reduced capacity of fluid pressurization in the defect cartilage. A partial-thickness defect could cause a fluid pressure decrease or increase in the remaining underlying cartilage depending on the defect depth. A cartilage defect also increased the shear strain at the cartilage-bone interface, which was more significant with a full-thickness defect. The effect of cartilage defect on the fluid pressurization also depended on the defect sites and contact conditions. In conclusion, a focal cartilage defect causes a fluid-pressure dependent load reallocation and a compromised load support in the joint, which depend on the defect depth, site, and contact condition.

  15. Corporate corruption of the environment: sustainability as a process of compromise.

    PubMed

    Nyberg, Daniel; Wright, Christopher

    2013-09-01

    A key response to environmental degradation, climate change and declining biodiversity has been the growing adoption of market principles in an effort to better value the social good of nature. Through concepts such as 'natural capitalism' and 'corporate environmentalism', nature is increasingly viewed as a domain of capitalist endeavour. In this article, we use convention theory and a pluralist understanding of social goods to investigate how the social good of the environment is usurped by the alternate social good of the market. Through analysis of interviews with sustainability managers and corporate documentation, we highlight how organizational actors employ compromise to temporally settle disputes between competing claims about environmental activities. Our findings contribute to an understanding of the processes of empirically grounded critique and the under-theorized concept of compromise between social goods. Rather than protecting the environment, the corporate promotion of sustainability facilitates the corruption of the social good of the environment and its conversion into a market commodity. © London School of Economics and Political Science 2013.

  16. Designing and Operating Through Compromise: Architectural Analysis of CKMS for the Advanced Metering Infrastructure

    SciTech Connect

    Duren, Mike; Aldridge, Hal; Abercrombie, Robert K; Sheldon, Frederick T

    2013-01-01

    Compromises attributable to the Advanced Persistent Threat (APT) highlight the necessity for constant vigilance. The APT provides a new perspective on security metrics (e.g., statistics based cyber security) and quantitative risk assessments. We consider design principals and models/tools that provide high assurance for energy delivery systems (EDS) operations regardless of the state of compromise. Cryptographic keys must be securely exchanged, then held and protected on either end of a communications link. This is challenging for a utility with numerous substations that must secure the intelligent electronic devices (IEDs) that may comprise complex control system of systems. For example, distribution and management of keys among the millions of intelligent meters within the Advanced Metering Infrastructure (AMI) is being implemented as part of the National Smart Grid initiative. Without a means for a secure cryptographic key management system (CKMS) no cryptographic solution can be widely deployed to protect the EDS infrastructure from cyber-attack. We consider 1) how security modeling is applied to key management and cyber security concerns on a continuous basis from design through operation, 2) how trusted models and key management architectures greatly impact failure scenarios, and 3) how hardware-enabled trust is a critical element to detecting, surviving, and recovering from attack.

  17. Psychological stress compromises CD8+ T cell control of latent herpes simplex virus type 1 infections.

    PubMed

    Freeman, Michael L; Sheridan, Brian S; Bonneau, Robert H; Hendricks, Robert L

    2007-07-01

    Recurrent HSV-1 ocular disease results from reactivation of latent virus in trigeminal ganglia, often following immunosuppression or exposure to a variety of psychological or physical stressors. HSV-specific CD8+ T cells can block HSV-1 reactivation from latency in ex vivo trigeminal ganglia cultures through production of IFN-gamma. In this study, we establish that either CD8+ T cell depletion or exposure to restraint stress permit HSV-1 to transiently escape from latency in vivo. Restraint stress caused a reduction of TG-resident HSV-specific CD8+ T cells and a functional compromise of those cells that survive. Together, these effects of stress resulted in an approximate 65% reduction of cells capable of producing IFN-gamma in response to reactivating virus. Our findings demonstrate persistent in vivo regulation of latent HSV-1 by CD8+ T cells, and strongly support the concept that stress induces HSV-1 reactivation from latency at least in part by compromising CD8+ T cell surveillance of latently infected neurons.

  18. Mixed-species Biofilm Compromises Wound Healing by Disrupting Epidermal Barrier Function

    PubMed Central

    Sinha, Mithun; Ganesh, Kasturi; Chaney, Sarah; Mann, Ethan; Miller, Christina; Khanna, Savita; Bergdall, Valerie K.; Powell, Heather M.; Cook, Charles H.; Gordillo, Gayle M.; Wozniak, Daniel J.; Sen, Chandan K.

    2015-01-01

    In chronic wounds, biofilm infects host tissue for extended periods of time. This work establishes the first chronic pre-clinical model of wound biofilm infection aimed at addressing long-term host response. Although biofilm infected wounds did not show marked differences in wound closure, the repaired skin demonstrated compromised barrier function. This observation is clinically significant because it leads to the notion that even if a biofilm infected wound is closed as observed visually, it may be complicated by the presence of failed skin which is likely to be infected and or further complicated post-closure. Study of underlying mechanisms recognized for the first time biofilm-inducible miR-146a and miR-106b in the host skin wound-edge tissue. These miRs silenced ZO-1 and ZO-2 to compromise tight junction function resulting in leaky skin as measured by transepidermal water loss. Intervention strategies aimed at inhibiting biofilm-inducible miRNAs may be productive in restoring barrier function of host skin. PMID:24771509

  19. 2-Sulfonylpyrimidines: Mild alkylating agents with anticancer activity toward p53-compromised cells

    PubMed Central

    Bauer, Matthias R.; Joerger, Andreas C.; Fersht, Alan R.

    2016-01-01

    The tumor suppressor p53 has the most frequently mutated gene in human cancers. Many of p53’s oncogenic mutants are just destabilized and rapidly aggregate, and are targets for stabilization by drugs. We found certain 2-sulfonylpyrimidines, including one named PK11007, to be mild thiol alkylators with anticancer activity in several cell lines, especially those with mutationally compromised p53. PK11007 acted by two routes: p53 dependent and p53 independent. PK11007 stabilized p53 in vitro via selective alkylation of two surface-exposed cysteines without compromising its DNA binding activity. Unstable p53 was reactivated by PK11007 in some cancer cell lines, leading to up-regulation of p53 target genes such as p21 and PUMA. More generally, there was cell death that was independent of p53 but dependent on glutathione depletion and associated with highly elevated levels of reactive oxygen species and induction of endoplasmic reticulum (ER) stress, as also found for the anticancer agent PRIMA-1MET(APR-246). PK11007 may be a lead for anticancer drugs that target cells with nonfunctional p53 or impaired reactive oxygen species (ROS) detoxification in a wide variety of mutant p53 cells. PMID:27551077

  20. Compromised Prefrontal Cognitive Control Over Emotional Interference in Adolescents with Internet Gaming Disorder.

    PubMed

    Lee, Junghan; Lee, Seojung; Chun, Ji Won; Cho, Hyun; Kim, Dai-jin; Jung, Young-Chul

    2015-11-01

    Increased reports of impulsivity and aggression in male adolescents with Internet gaming might reflect their dysfunction in emotion regulation, particularly in suppression of negative emotions, which should affect the various stages of Internet gaming disorder. This study tested the hypothesis that adolescents with Internet gaming disorder would be more disturbed by the emotional interference and demonstrate compromised dorsal anterior cingulate cortex (dACC) activation during a Stroop Match-to-Sample task. In addition, functional connectivity analysis was conducted to examine the interplays between neural correlates involved in emotional processing and how they were altered in adolescents with Internet gaming disorder. The Internet gaming disorder group demonstrated weaker dACC activation and stronger insular activations to interfering angry facial stimuli compared with the healthy control group. Negative functional connectivity between stronger insular activation and weaker dorsolateral prefrontal activation correlated with higher cognitive impulsivity in adolescents with Internet gaming disorder. These findings provide evidence of the compromised prefrontal cognitive control over emotional interference in adolescents with Internet gaming disorder.