Search

Objective: Tinnitus may be associated with various brain changes. However, the degenerative changes in patients with tinnitus have not been extensively investigated. We aimed to evaluate degenerative, structural, and functional brain changes in patients with mild cognitive impairment (MCI) who also suffer from tinnitus. Materials and methods: This study included participants aged 60 to 80 years with MCI and a hearing level better than 40 dB. The participants were classified into two groups: MCI with tinnitus (MCI-T) and MCI without tinnitus (MCI-NT). All patients underwent Tinnitus Handicap Inventory (THI), 3 T brain MRI, F18-florapronol PET, and F18-FDG PET. Results: The MCI-T group exhibited higher ß-amyloid deposition in the superior temporal gyrus, temporal pole, and middle temporal gyrus compared to the MCI-NT group (p < 0.05 for all). Additionally, the MCI-T group showed increased metabolism in the inferior frontal gyrus, insula, and anterior cingulate cortex (ACC) (p < 0.005 for all). The THI score was strongly correlated with increased volume in the insula, ACC, superior frontal gyrus, supplementary motor area, white matter near the hippocampus, and precentral gyrus (p < 0.05 for all). Moreover, the MCI-T group demonstrated higher metabolic activity in the default mode network (DMN) and lower activity in the executive control network (ECN) (p < 0.05 for all). In the MCI-T group, the posterior DMN was positively correlated with the visual network and negatively with the ECN, whereas in the MCI-NT group, it correlated positively with the ECN. Conclusion: The MCI-T group exhibited greater ß-amyloid accumulation in the auditory cortex and more extensive changes across various brain networks compared with the MCI-NT group, potentially leading to diverse clinical symptoms such as dementia with semantic deficits or depression. Tinnitus in MCI patients may serve as a biomarker for degenerative changes in the temporal lobe and alterations in brain network dynamics. [ABSTRACT FROM AUTHOR]

Targeted protein degradation (TPD) has been established as a viable alternative to attenuate the function of a specific protein of interest in both biological and clinical contexts. The unique TPD mode-of-action has allowed previously undruggable proteins to become feasible targets, expanding the landscape of "druggable" properties and "privileged" target proteins. As TPD continues to evolve, a range of innovative strategies, which do not depend on recruiting E3 ubiquitin ligases as in proteolysis-targeting chimeras (PROTACs), have emerged. Here, we present an overview of direct lysosome- and proteasome-engaging modalities and discuss their perspectives, advantages, and limitations. We outline the chemical composition, biochemical activity, and pharmaceutical characteristics of each degrader. These alternative TPD approaches not only complement the first generation of PROTACs for intracellular protein degradation but also offer unique strategies for targeting pathologic proteins located on the cell membrane and in the extracellular space. [ABSTRACT FROM AUTHOR]

In eukaryotes, a primary protein quality control (PQC) process involves the destruction of conformationally misfolded proteins through the ubiquitin-proteasome system. Because approximately one-third of eukaryotic proteomes fold and assemble within the endoplasmic reticulum (ER) before being sent to their destinations, the ER plays a crucial role in PQC. The specific functions and biochemical roles of several E3 ubiquitin ligases involved in ER-associated degradation in mammals, on the other hand, are mainly unknown. We identified 2 E3 ligases, ubiquitin protein ligase E3 component Nrecognin 1 (UBR1) and ubiquitin protein ligase E3 component N-recognin 2 (UBR2), which are the key N-recognins in the Ndegron pathway and participate in the ER stress response in mammalian cells by modulating their stability. Cells lacking UBR1 and UBR2 are hypersensitive to ER stress-induced apoptosis. Under normal circumstances, these proteins are polyubiquitinated through Lys48-specific linkages and are then degraded by the 26S proteasome. In contrast, when cells are subjected to ER stress, UBR1 and UBR2 exhibit greater stability, potentially as a cellular adaptive response to stressful conditions. Although the precise mechanisms underlying these findings require further investigation, our findings show that cytoplasmic UBR1 and UBR2 have anti-ER stress activities and contribute to global PQC in mammals. These data also reveal an additional level of complexity within the mammalian ER-associated degradation system, implicating potential involvement of the N-degron pathway. [ABSTRACT FROM AUTHOR]

Dental bases require low thermal conductivity and good mechanical properties, such as bonding with composite resins. This study aims to elucidate the physicochemical properties of premixed mineral trioxide aggregate (MTA) for its suitability as a dental base and to explore the optimal adhesive strategy with composite resin. The thermal conductivity and compressive strength of this premixed MTA are 0.12 W/(m•K) and 93.76 MPa, respectively, Which are deemed adequate for its application as dental base. When bonded to composite resin, the use of 37% phosphoric acid etching before applying the Clearfil SE bond significantly reduced the bonding strength between composite resin and premixed MTA. This was because the compressive strength and Vickers hardness of premixed MTA decreased, and tricalcium silicate was dissolved from the surface during acid etching. Therefore, it is recommended to avoid using 37% phosphoric acid etching when bonding premixed MTA and composite resin as a dental base. [ABSTRACT FROM AUTHOR]

In tauopathy conditions, such as Alzheimer's disease (AD), highly soluble and natively unfolded tau polymerizes into an insoluble filament; however, the mechanistic details of this process remain unclear. In the brains of AD patients, only a minor segment of tau forms β-helix-stacked protofilaments, while its flanking regions form disordered fuzzy coats. Here, it is demonstrated that the tau AD nucleation core (tau-AC) sufficiently induced self-aggregation and recruited full-length tau to filaments. Unexpectedly, phospho-mimetic forms of tau-AC (at Ser324 or Ser356) show markedly reduced oligomerization and seeding propensities. Biophysical analysis reveal that the N-terminus of tau-AC facilitates the fibrillization kinetics as a nucleation motif, which becomes sterically shielded through phosphorylation-induced conformational changes in tau-AC. Tau-AC oligomers are efficiently internalized into cells via endocytosis and induced endogenous tau aggregation. In primary hippocampal neurons, tau-AC impaired axon initial segment plasticity upon chronic depolarization and is mislocalized to the somatodendritic compartments. Furthermore, it is observed significantly impaired memory retrieval in mice intrahippocampally injected with tau-AC fibrils, which corresponds to the neuropathological staining and neuronal loss in the brain. These findings identify tau-AC species as a key neuropathological driver in AD, suggesting novel strategies for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Host cell membrane-trafficking pathways are often manipulated by bacterial pathogens to gain cell entry, avoid immune responses, or to obtain nutrients. The 1,369-residue OtDUB protein from the obligate intracellular human pathogen Orientia tsutsugamushi bears a deubiquitylase (DUB) and additional domains. Here we show that OtDUB ectopic expression disrupts membrane trafficking through multiple mechanisms. OtDUB binds directly to the clathrin adaptor-protein (AP) complexes AP-1 and AP-2, and the OtDUB275-675 fragment is sufficient for binding to either complex. To assess the impact of OtDUB interactions with AP-1 and AP-2, we examined trans-Golgi trafficking and endocytosis, respectively. Endocytosis is reduced by two separate OtDUB fragments: one contains the AP-binding domain (OtDUB1-675), and the other does not (OtDUB675-1369). OtDUB1-675 disruption of endocytosis requires its ubiquitin-binding capabilities. OtDUB675-1369 also fragments trans- and cis-Golgi structures. Using a growth-based selection in yeast, we identified viable OtDUB675-1369 point mutants that also no longer caused Golgi defects in human cells. In parallel, we found OtDUB675-1369 binds directly to phosphatidylserine, and this lipid binding is lost in the same mutants. Together these results show that OtDUB contains multiple activities capable of modulating membrane trafficking. We discuss how these activities may contribute to Orientia infections. [ABSTRACT FROM AUTHOR]

Background: Although the existence of proteasomes in human blood, termed circulating proteasomes (c-proteasomes), has been reported previously, their origin and pathophysiological functions remain largely unknown.Objective: Given that c-proteasome activity was significantly reduced in Alzheimer's disease model mice and relatively high frequency of mild cognitive impairment (MCI) is accompanied by chronic tinnitus in aged patients, we examined whether c-proteasome activity in human plasma was associated with cognitive function in patients with chronic tinnitus.Methods: c-Proteasome activity in the plasma of tinnitus patients (N = 55) was measured with fluorogenic reporter substrate, suc-LLVY-AMC. To assess MCI, the Montreal Cognitive Assessment was conducted with a cut-off score of 22/23. All patients underwent audiological and psychoacoustic analyses. Levels of c-proteasomes, Aβ42, and Aβ40 were measured using ELISA, and their association with c-proteasome activity was evaluated.Results: The activity of circulating proteasomes was significantly lower in patients with chronic tinnitus and MCI (p = 0.042), whereas activities of other plasma enzymes showed little correlation. In addition, c-proteasome activity was negatively associated with the level of plasma Aβ and was directly dependent on its own concentration in the plasma of patients with chronic tinnitus.Conclusion: Our current work provides a new perspective for understanding the potential relationship between circulating proteasomes in the plasma and cognitive dysfunction, suggesting a novel, non-invasive biomarker in the context of MCI diagnosis. [ABSTRACT FROM AUTHOR]

The 26S proteasome, a self-compartmentalized protease complex, plays a crucial role in protein quality control. Multiple levels of regulatory systems modulate proteasomal activity for substrate hydrolysis. However, the destruction mechanism of mammalian proteasomes is poorly understood. We found that inhibited proteasomes are sequestered into the insoluble aggresome via HDAC6- and dynein-mediated transport. These proteasomes colocalized with the autophagic receptor SQSTM1 and cleared through selective macroautophagy, linking aggresomal segregation to autophagic degradation. This proteaphagic pathway was counterbalanced with the recovery of proteasomal activity and was critical for reducing cellular proteasomal stress. Changes in associated proteins and polyubiquitylation on inhibited 26S proteasomes participated in the targeting mechanism to the aggresome and autophagosome. The STUB1 E3 Ub ligase specifically ubiquitylated purified human proteasomes in vitro, mainly via Lys63-linked chains. Genetic and chemical inhibition of STUB1 activity significantly impaired proteasome processing and reduced resistance to proteasomal stress. These data demonstrate that aggresomal sequestration is the crucial upstream event for proteasome quality control and overall protein homeostasis in mammals. [ABSTRACT FROM AUTHOR]

Background/Aims: The complicated differentiation processes of cells in skeletal muscle against inflammation that induce muscle atrophy are not fully elucidated. Given that skeletal muscle is a secretory organ, we evaluated the effects of inflammation on myogenic signals and myokine expression, and the roles of inflammatory exosomes released by myotubes in myogenic differentiation. Methods: Inflammation was induced by treatment of fully differentiated C2C12 myotubes with a cytokine mixture of TNF-α and INF-β. Exosome-like vesicles (ELVs) were isolated from conditioned media of control or inflamed myotubes and incubated with myoblasts. The expression of molecular switches that contribute to myogenic differentiation, including several kinases, their downstream targets, and myokines, were evaluated using immunoblot analysis in inflamed myotubes and in myoblasts treated with ELVs. Results: Inflammation activated molecular mechanisms contributing to muscle atrophy, including AMPK, p-38 MAPK and JNK, while inhibiting Akt-mediated myogenic signals. In addition, inflammation induced myostatin expression with suppression of a myostatincounteracting myokine, decorin. Well-characterized ELVs released from inflamed myotubes induced myoblast inflammation and inhibited myogenic mechanisms while stimulating atrophic signals. Conclusion: Inflammation of skeletal muscle induces muscle atrophy via multiple mechanisms, including the regulation of myokines and kinases. Inflammatory ELVs are likely to contribute to inflammation-induced muscle atrophy. [ABSTRACT FROM AUTHOR]

The advent of the Fourth Industry Revolution calls for companies to radically rethink existing business models and innovate business models through detailed and consistent strategies. In this study, three types of business model frameworks are presented as methods to cope with the Fourth Industrial Revolution at the enterprise level. We also have designed business model frameworks that utilizes four axes; hyperconnectivity, hyper-intelligence, hyper-convergence, and hyper-predictability. And then, we finally suggest a framework of smart connected business model. This model uses information and communication technology to create an online and offline platform, enhances the connectivity of human beings, objects and markets, and analyzes and utilizes the data generated here. It is a circulation structure that develops existing products (or services), market, and business models, which create prediction, customization, and innovation. [ABSTRACT FROM AUTHOR]

Background/Aims: The 26S proteasome is the key proteolytic complex for recognition and degradation of polyubiquitinated target substrates in eukaryotes. Among numerous proteasome-associated proteins, a deubiquitinating enzyme (DUB) USP14 has been identified as an endogenous inhibitor of the proteasome. Here, we explored the complex regulatory functions of USP14 that involve ubiquitin (Ub) homeostasis and substrate degradation in flies and mammals. Methods: USP14-null primary and immortalized mouse embryonic fibroblasts (MEFs) and USP14 knocked-down Drosophila were analyzed in this study. We measured proteasome and DUB activities using fluorogenic reporter substrates and adductforming probes. To examine the levels of ubiquitin, we performed immunoblotting and immunohistochemistry. Mass spectrometry (MS) was used to examine polyUb chain linkages and USP14-interacing proteins. Cell cycle was analyzed by flow cytometry, BrdU labeling, and phospho-histone H3 staining. Results: The homeostasis of Ub in USP14-/- MEFs was markedly perturbed because of facilitated clearance of Ub. This phenomenon was recapitulated in muscles of USP14-deficient Drosophila with old ages. Absolute quantitation using MS also revealed that USP14-/- MEFs contained significantly increased amounts of Ub, compared with wild-type. The key phenotype of USP14-/- MEFs was their delayed proliferation originated from prolonged interphase possibly through aberrant degradation of cyclins A and B1. We found that knocking down USP14 in Drosophila resulted in delayed eye development associated with reduced mitotic activity. Conclusion: Our study identifies novel cellular functions of USP14 not only in cellular Ub hometostasis but also in cell cycle progression. USP14 was also essential for proper Drosophila eye development. These results strongly suggest that the USP14-mediated proteasome activity regulation may be directly related to various human diseases including cancer. [ABSTRACT FROM AUTHOR]

Macroautophagy mediates the selective degradation of proteins and non-proteinaceous cellular constituents. Here, we show that the N-end rule pathway modulates macroautophagy. In this mechanism, the autophagic adapter p62/SQSTM1/Sequestosome-1 is an N-recognin that binds type-1 and type-2 N-terminal degrons (N-degrons), including arginine (Nt-Arg). Both types of N-degrons bind its ZZ domain. By employing three-dimensional modeling, we developed synthetic ligands to p62 ZZ domain. The binding of Nt-Arg and synthetic ligands to ZZ domain facilitates disulfide bond-linked aggregation of p62 and p62 interaction with LC3, leading to the delivery of p62 and its cargoes to the autophagosome. Upon binding to its ligand, p62 acts as a modulator of macroautophagy, inducing autophagosome biogenesis. Through these dual functions, cells can activate p62 and induce selective autophagy upon the accumulation of autophagic cargoes. We also propose that p62 mediates the crosstalk between the ubiquitin-proteasome system and autophagy through its binding Nt-Arg and other N-degrons. [ABSTRACT FROM AUTHOR]

Senescence-accelerated mouse prone 8 (SAMP8), a non-transgenic animal model used for researching sporadic Alzheimer's disease (AD), presents AD pathologies and overall dysregulation in brain energy metabolism, which is one of the early pathogenic characteristics of AD. In the present study, the authors examined chronological changes in the expression patterns of phosphorylated tau and of proteins related to energy metabolism to evaluate the association of tau phosphorylation and metabolism, using young- (2-months-old), middle- (5-months-old) and old-aged (10-months-old) SAMP8. The levels of phosphorylated 5'-AMP activated protein kinase at Thr172 (p-AMPK) and phosphorylated glycogen synthase kinase 3ß (p-GSK3ßS9) in the cortex of SAMP8 at 2 months were significantly higher than those in senescence-accelerated mouse resistant 1 (SAMR1). The differences were not detected at 5 and 10 months of age, which were concurrent with the changes in levels of phosphorylated tau at Ser396 (p-tauS396), but not with p-tauS262. The level of p-tauS262 was considerably higher in the cortex of middle-aged SAMP8 when compared with that of SAMR1 and sustained in old-aged SAMP8, but not in the young cortex. The levels of cortical sirtuin1 (Sirt1) and insulin receptor substrate 1 (IRS-1) expression of young SAMP8 were significantly lower, when compared with those in SAMR1. However, in the hippocampus of SAMP8, the patterns of chronological changes and levels of p-tau, p-AMPK, Sirt1 and IRS-1 relative to SAMR1 were different from those in the cortex. Taken together, the results suggested that regulation of tau phosphorylation via the AMPK-GSK3ß pathway concurrent with dysregulation of energy metabolism may precede the pathological tau hyperphosphorylation in the cortex of SAMP8, and that the regulation of AMPK-GSK3ß-mediated tau phosphorylation may be dependent on phosphor-epitope in tau or the region of brain. [ABSTRACT FROM AUTHOR]

Exosomes are extracellular vesicles that contain molecules that regulate the metabolic functions of adjacent or remote cells. Recent in vitro, in vivo and clinical studies support the hypothesis that exosomes released from various cell types play roles in the progression of metabolic disorders including type 2 diabetes. Based on this concept and advances in other diseases, the proteins, mRNA, microRNA and lipids in exosomes isolated from biological fluids have been proposed as biomarkers in metabolic disorders. However, several problems with the development of clinically applicable biomarkers have not been resolved. In this review, the biologic functions of exosomes are briefly introduced, and we discuss the technical and practical pros and cons of different methods of exosome isolation for the identification of exosomal biomarkers of metabolic disorders. Standardization of preanalytical variables and isolation of high-purity exosomes from fully characterized biological fluids will be necessary for the identification of useful exosomal biomarkers that can provide insights into the pathogenic mechanisms of complications of metabolic syndrome and of whole-body metabolism. [ABSTRACT FROM AUTHOR]

Nature-based tourism destinations--locations in which economic viability and environmental responsibility are sought--are sensitive to climate change and its effects on important environmental components of the tourism areas. To meet the dual roles, it is important for destination marketers and resources managers to provide quality experiences for tourists and to induce tourists' environmentally responsible behavior in such destinations. This study documents the importance of perceptions toward climate change and tourist experiences in determining tourists' environmentally responsible behavior while enjoying holidays at nature-based tourism destinations in Jeju Island, South Korea. Two hundred and eleven Korean and 204 Chinese tourists marked dominant tourist arrivals to the island, and responded to the survey questionnaire. Results showed that perceptions toward climate change and tourist experiences affect Korean tourists' environmentally responsible behavior intentions, whereas tourist experiences--not perceptions toward climate change--only significantly affect Chinese tourists' behavior intention. In a nature-based tourism context under the pressure of climate change and adverse environmental effects as consequences of tourism activities, resources managers and destination marketers need to develop environmental campaigns or informative tourist programs to formulate environmentally responsible behavior as well as to increase tourist quality experiences among domestic and international tourists. [ABSTRACT FROM AUTHOR]

This study presents a compact dual-band antenna for wireless local area network (WLAN) applications. The proposed antenna consists of small striplines on both sides of a substrate and a lumped capacitor on the top side to reduce the antenna size. As a folded monopole-type resonance is occurred in 5 GHz band, the proposed antenna yields dual-band characteristics. The resonant mechanism is also analysed using the equivalent circuit model. Electric characteristics of the proposed antenna such as radiation patterns, peak gains, and radiation efficiencies, are presented through the simulation and measurement under various conditions. The antenna size is only 5 x 9 mm². The proposed antenna can cover both WLAN bands of 2.4 and 5 GHz. [ABSTRACT FROM AUTHOR]

In the arginylation branch of the N-end rule pathway, unacetylated N-terminal destabilizing residues function as essential determinants of protein degradation signals (N-degron). Here, we show that a neurostimulant, para-chloroamphetamine (PCA), specifically inhibits the Arg/N-end rule pathway, delaying the degradation of its artificial and physiological substrates, including regulators of G protein signaling 4 (RGS4), in vitro and in cultured cells. In silico computational analysis indicated that PCA strongly interacts with both UBR box and ClpS box, which bind to type 1 and type 2 N-degrons, respectively. Moreover, intraperitoneal injection of PCA significantly stabilized endogenous RGS4 proteins in the whole mouse brain and, particularly, in the frontal cortex and hippocampus. Consistent with the role of RGS4 inG protein signaling, treatment with PCA impaired the activations of GPCR downstream effectors in N2A cells, phenocopying ATE1-null mutants. In addition, levels of pathological C-terminal fragments of TDP43 bearing N-degrons (Arg208-TDP25) were significantly elevated in the presence of PCA. Thus, our study identifies PCA as a potential tool to understand and modulate various pathological processes regulated by the Arg/N-end rule pathway, including neurodegenerative processes in FTLD-U and ALS. [ABSTRACT FROM AUTHOR]

Although Mycobacterium avium complex (MAC) is the most common pathogen in nontuberculous mycobacterial (NTM) pulmonary diseases, endobronchial lesions caused by MAC infections are very rare even in an immunocompromised host. Herein, we describe the case of a 59-year-old, HIV-negative and non-immunocompromised woman who developed multi-focal pulmonary infiltrations with endobronchial lesion caused by M. avium. Bronchoscopic examination revealed white- and yellow-colored irregular mucosal lesions in the bronchus of the left lingular division. M. avium was identified using sputum culture and bronchial washing fluid culture. Following the recommendations of the American Thoracic Society and Infectious Diseases Society of America (ATS/IDSA), the patient was begun on treatment with antimycobacterial drugs. After treatment, pneumonic infiltration decreased. [ABSTRACT FROM AUTHOR]

Background The anterolateral thigh (ALT) perforator flap has become a popular option for treating soft tissue defects of lower extremity reconstruction and can be combined with a segment of the vastus lateralis muscle. We present a comparison of the use of the ALT fasciocutaneous (ALT-FC) and myocutaneous flaps. Methods We retrospectively reviewed patients in whom free-tissue transfer was performed between 2005 and 2011 for the reconstruction of lower extremity soft-tissue defects. Twentyfour patients were divided into two groups: reconstruction using an ALT-FC flap (12 cases) and reconstruction using a vastus lateralis myocutaneous (VL-MC) flap (12 cases). Postoperative complications, functional results, cosmetic results, and donor-site morbidities were studied. Results Complete flap survival was 100% in both groups. A flap complication was noted in one case (marginal dehiscence) of the ALT-FC group, and no complications were noted in the VL-MC group. In both groups, one case of partial skin graft loss occurred at the donor site, and debulking surgeries were needed for two cases. There were no significant differences in the mean scores for either functional or cosmetic outcomes in either group. Conclusions The VL-MC flap is able to fill occasional dead space and has comparable survival rates to ALT-FC with minimal donor-site morbidity. Additionally, the VL-MC flap is easily elevated without myocutaneous perforator injury. [ABSTRACT FROM AUTHOR]

The N-end rule pathway is a proteolytic system in which its recognition components (N-recognins) recognize destabilizing N-terminal residues of short-lived proteins as an essential element of specific degrons, called N-degrons. The RING E3 ligases UBR2 and UBR1 are major N-recognins that share size (200 kDa), conserved domains and substrate specificities to Ndegrons. Despite the known function of the N-end rule pathway in degradation of cytosolic proteins, the major phenotype of UBR2-deficient male mice is infertility caused by arrest of spermatocytes at meiotic prophase I. UBR2-deficient spermatocytes are impaired in transcriptional silencing of sex chromosome-linked genes and ubiquitylation of histone H2A. In this study we show that the recruitment of UBR2 to meiotic chromosomes spatiotemporally correlates to the induction of chromatin-associated ubiquitylation, which is significantly impaired in UBR2-deficient spermatocytes. UBR2 functions as a scaffold E3 that promotes HR6B/UbcH2-dependent ubiquitylation of H2A and H2B but not H3 and H4, through a mechanism distinct from typical polyubiquitylation. The E3 activity of UBR2 in histone ubiquitylation is allosterically activated by dipeptides bearing destabilizing N-terminal residues. Insufficient monoubiquitylation and polyubiquitylation on UBR2-deficient meiotic chromosomes correlate to defects in double strand break (DSB) repair and other meiotic processes, resulting in pachytene arrest at stage IV and apoptosis. Some of these functions of UBR2 are observed in somatic cells, in which UBR2 is a chromatin-binding protein involved in chromatin-associated ubiquitylation upon DNA damage. UBR2-deficient somatic cells show an array of chromosomal abnormalities, including hyperproliferation, chromosome instability, and hypersensitivity to DNA damage-inducing reagents. UBR2-deficient mice enriched in C57 background die upon birth with defects in lung expansion and neural development. Thus, UBR2, known as the recognition component of a major cellular proteolytic system, is associated with chromatin and controls chromatin dynamics and gene expression in both germ cells and somatic cells. [ABSTRACT FROM AUTHOR]

It has been rereported that axons which display 5-hydroxytryptamine (5-HT) immunoreactivity are abundant in the pancreas and the majority of serotonergic axons terminate within intrapancreatic ganglia, islet and acini. This histological result strongly suggests that intrapancreatic serotonergic nerves could affect to the pancreatic endocrine and exocrine secretion. Thus, this study was aimed to investigate whether intrapancreatic serotonergic nerves could affect pancreatic exocrine secretion and an action mechanism of the intrapancreatic serotonergic nerves. The rats were anesthetized with a single injection of urethane. The median line and the abdominal aorta was carefully dissected and cannulated with PE-50 tubing just above the celiac artery, and then tightly ligated just below the superior mesenteric artery. The pancreatic duct was also cannulated with Tygon microbore tubing. With the addition of serotonin, pancreatic volume flow and amylase output were significantly inhibited electrical field stimulation (EFS). On the other hand, pancreatic volume flow and amylase output were significantly elevated in EFS with the addition of spiperone. EFS application, however, pancreatic volume flow and amylase output had no significant change in cholecystokinin (CCK) alone when serotonin was applied under a 5.6 mM glucose background. Pancreatic volume flow and amylase output under 18 mM glucose background were significantly elevated in CCK plus serotonin than in CCK alone. These data suggest that intrapancreatic serotonergic nerves play an inhibitory role in pancreatic exocrine secretion and an important role in the insulin action or release. [ABSTRACT FROM AUTHOR]

Proteasomes, the primary mediators of ubiquitin–protein conjugate degradation, are regulated through complex and poorly understood mechanisms. Here we show that USP14, a proteasome-associated deubiquitinating enzyme, can inhibit the degradation of ubiquitin–protein conjugates both in vitro and in cells. A catalytically inactive variant of USP14 has reduced inhibitory activity, indicating that inhibition is mediated by trimming of the ubiquitin chain on the substrate. A high-throughput screen identified a selective small-molecule inhibitor of the deubiquitinating activity of human USP14. Treatment of cultured cells with this compound enhanced degradation of several proteasome substrates that have been implicated in neurodegenerative disease. USP14 inhibition accelerated the degradation of oxidized proteins and enhanced resistance to oxidative stress. Enhancement of proteasome activity through inhibition of USP14 may offer a strategy to reduce the levels of aberrant proteins in cells under proteotoxic stress. [ABSTRACT FROM AUTHOR]

Ubiquitination of histones provides an important mechanism regulating chromatin remodeling and gene expression. Recent studies have revealed ubiquitin ligases involved in histone ubiquitination, yet the responsible enzymes and the function of histone ubiquitination in spermatogenesis remain unclear. We have previously shown that mice lacking the ubiquitin ligase UBR2. one of the recognition E3 components of the N-end rule proteolytic pathway, are infertile associated with meiotic arrest at prophase I. We here show that UBR2 localizes to meiotic chromatin regions, including unsynapsed axial elements linked to chromatin inactivation, and mediates transcriptional silencing via the ubiquitination of histone H2A. UBR2 interacts with the ubiquitin conjugating enzyme HR6B and its substrate H2A and promotes the HR6B-H2A interaction and the HR6B-to-H2A transfer of ubiquitin. UBR2 and ubiquitinated H2A (uH2A) spatiotemporally mark meiotic chromatin regions subject to transcriptional silencing, and UBR2-deficient spermatocytes fail to induce the ubiquitination of H2A during meiosis. UBR2-deficient spermatocytes are profoundly impaired in chromosomewide transcriptional silencing of genes linked to unsynapsed axes of the X and Y chromosomes. Our findings suggest that insufficiency in UBR2-dependent histone ubiquitiriation triggers a pachytene checkpoint system, providing a new insight into chromatin remodeling and gene expression regulation. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract  As the amount of text data grows explosively, an efficient index structure for large text databases becomes ever important. The n-gram inverted index (simply, the n-gram index) has been widely used in information retrieval or in approximate string matching due to its two major advantages: language-neutral and error-tolerant. Nevertheless, the n-gram index also has drawbacks: the size tends to be very large, and the performance of queries tends to be bad. In this paper, we propose the two-level n-gram inverted index (simply, the n-gram/2L index) that significantly reduces the size and improves the query performance by using the relational normalization theory. We first identify that, in the (full-text) n-gram index, there exists redundancy in the position information caused by a non-trivial multivalued dependency. The proposed index eliminates such redundancy by constructing the index in two levels: the front-end index and the back-end index. We formally prove that this two-level construction is identical to the relational normalization process. We call this process structural optimization of the n-gram index. The n-gram/2L index has excellent properties: (1) it significantly reduces the size and improves the performance compared with the n-gram index with these improvements becoming more marked as the database size gets larger; (2) the query processing time increases only very slightly as the query length gets longer. Experimental results using real databases of 1 GB show that the size of the n-gram/2L index is reduced by up to 1.9–2.4 times and, at the same time, the query performance is improved by up to 13.1 times compared with those of the n-gram index. We also compare the n-gram/2L index with Makinen’s compact suffix array (CSA) (Proc. 11th Annual Symposium on Combinatorial Pattern Matching pp. 305–319, 2000) stored in disk. Experimental results show that the n-gram/2L index outperforms the CSA when the query length is short (i.e., less than 15–20), and the CSA is similar to or better than the n-gram/2L index when the query length is long (i.e., more than 15–20). [ABSTRACT FROM AUTHOR]

Tumor angiogenesis is required for tumor development and is stimulated by angiogenic inducers like VEGF (vascular endothelial growth factor). Our previous study demonstrated that STAT3 (signal transducer and activator of transcription 3) up-regulates HIF-1α (hypoxia inducible factor-1α) protein stability and enhances HIF-1-mediated VEGF expression in hypoxic solid tumor cells, thus suggesting that the inhibition of STAT3 signaling may have clinical applications. In this study, we examined in vitro and in vivo, whether caffeic acid (CA) or its derivative CADPE [3-(3,4-dihydroxy-phenyl)-acrylic acid 2-(3,4-dihydroxy-phenyl)-ethyl ester] exert anticancer activity by targeting STAT3. It was found that CA or CADPE significantly inhibit STAT3 activity, and that this in turn down-regulates HIF-1α activity. Consequently, sequential blockade of STAT3 and HIF-1α resulted in the down-regulation of VEGF by inhibiting their recruitment to the VEGF promoter. In mice bearing a Caki-I carcinoma, both CA and CADPE retarded tumor growth and suppressed STAT3 phosphorylation, HIF-1α expression, vascularization and STAT3-inducible VEGF gene expression in tumors. Taken together, our results demonstrate that CA and CADPE are potential inhibitors of STAT3 and that they suppress tumor angiogenesis by inhibiting the activity of STAT3, the expression of HIF-1α and VEGF. [ABSTRACT FROM PUBLISHER]

We present a new method for computing temporal aggregation that uses a multidimensional index. The novelty of our method lies in mapping the start time and end time of a temporal tuple to a data point in a two-dimensional space, which is stored in a two-dimensional index, and in calculating the temporal aggregates through a temporal join between the data in the index and the base intervals (defined as the intervals delimited by the start times or end times of the tuples). To enhance the performance, this method calculates the aggregates by incrementally modifying the aggregates from that of the previous base interval without re-reading all tuples for the current base interval. We have compared our method with the SB-tree, which is the state-of-the-art method for temporal aggregation. The results show that our method is an order of magnitude more efficient than the SB-tree method in an environment with frequent updates, while comparable in a read-only environment as the number of aggregates calculated in a query increases. [ABSTRACT FROM AUTHOR]

Spatial joins find all pairs of objects that satisfy a given spatial relationship. In spatial joins using indexes, original-space indexes such as the R-tree are widely used. An original-space index is the one that indexes objects as represented in the original space. Since original-space indexes deal with extents of objects, it is relatively complex to optimize join algorithms using these indexes. On the other hand, transform-space indexes, which transform objects in the original space into points in the transform space and index them, deal only with points but no extents. Thus, optimization of join algorithms using these indexes can be relatively simple. However, the disadvantage of these join algorithms is that they cannot be applied to original-space indexes such as the A-tree. In this paper, we present a novel mechanism for achieving the best of these two types of algorithms. Specifically, we propose the new notion of the transform-space view and present the transform-space viewjoin algorithm. The transform-space view is a virtual transform-space index based on an original-space index. It allows us to "interpret" or "view" an existing original-space index as a transform-space index with no space and negligible time overhead and without actually modifying the structure of the original-space index or changing object representation. The transform-space view join algorithm joins two original-space indexes in the transform space through the notion of the transform-space view. Through analysis and experiments, we verity the excellence of the transform-space view join algorithm. The transform-space view join algorithm always outperforms existing ones for all the data sets tested in terms of all three measures used: the one-pass buffer size (the minimum buffer size required for guaranteeing one disk access per page), the number of disk accesses for a given buffer size, and the wall clock time. Thus, it constitutes a lower-bound algorithm. We believe that the proposed transform-space view can be applied to developing various new spatial query processing algorithms in the transform space. [ABSTRACT FROM AUTHOR]

The ATE1-encoded Arg-transferase mediates conjugation of Arg to N-terminal Asp, Glu, and Cys of certain eukaryotic proteins, yielding N-terminal Arg that can act as a degradation signal for the ubiquitin-dependent N-end rule pathway. We have previously shown that mouse ATE1-/- embryos die with defects in heart development and angiogenesis. Here, we report that the ATE1 Arg-transferase mediates the in vivo degradation of RGS4 and RGS5, which are negative regulators of specific G proteins whose functions include cardiac growth and angiogenesis. The proteolysis of these regulators of G protein signaling (RGS) proteins was perturbed either by hypoxia or in cells lacking ubiquitin ligases UBR1 and/or UBR2. Mutant RGS proteins in which the conserved Cys-2 residue could not become N-terminal were long-lived in vivo. We propose a model in which the sequential modifications of RGS4, RGSS, and RGSI6 (N-terminal exposure of their Cys-2, its oxidation, and subsequent arginylation) act as a licensing mechanism in response to extracellular and intracellular signals before the targeting for proteolysis by UBR1 and UBR2. We also show that ATE-/- embryos are impaired in the activation of extracellular signal-regulated kinase mitogen-activated protein kinases and in the expression of G protein-induced downstream effectors such as Jun. cyclin D1, and β-myosin heavy chain. These results establish RGS4 and RGS5 as in vivo substrates of the mammalian N-end rule pathway and also suggest that the O2-ATE1-UBR1/UBR2 proteolytic circuit plays a role in RES-regulated G protein signaling in the cardiovascular system. [ABSTRACT FROM AUTHOR]

Objective: To investigate histopathological changes and distribution of coxsackievirus B5 (CVB5) RNA in mouse heart, liver, and pancreas during the acute phase of infection. Methods: C3H/HeJ male mice, aged 3–4 weeks, were inoculated intraperitoneally with 5 × 105 plaque-forming units of CVB5 and sacrificed at 1, 2, 3, 4, 7 and 10 days postinfection (p.i.). Inflammation of the heart, liver, and pancreatic tissue sections was evaluated by hematoxylin and eosin staining, and virus was detected using antibody to viral coat protein VP1. A quantitative real-time RT-PCR method, using primers and probe targeted to the highly conserved sequences in the 5’-untranslated region of the virus, was used to evaluate the kinetics of CVB5 RNA during the development of myocarditis or pancreatitis. Results: Marginal inflammatory changes were observed in the heart tissues although viral RNA was constantly present between 1 and 10 days p.i., peaking at 4 days p.i. The pancreatic tissues displayed massive lymphocyte infiltration and loss of acinar cells at day 4 p.i. and viral RNA was detected between 1 and 10 days p.i., peaking at 2–3 days p.i. In the liver, viral RNA was detected between 1 and 7 days. No mortality was observed. Conclusions: CVB5 induced acute pancreatitis without subsequent development of myocarditis. Clearance of CVB5 RNA from the pancreas and heart was slower than clearance from the liver. Our real-time RT-PCR method, which is more sensitive than conventional plaque assay, may provide valuable insight into viral RNA kinetics during CVB5 infection. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Change is inevitable on construction projects, primarily because of the uniqueness of each project and the limited resources of time and money that can be spent on planning, executing, and delivering the project. Change clauses, which authorize the owner to alter work performed by the contractor, are included in most construction contracts and provide a mechanism for equitable adjustment to the contract price and duration. Even so, owners and contractors do not always agree on the adjusted contract price or the time it will take to incorporate the change. What is needed is a method to quantify the impact that the adjustments required by the change will have on the changed and unchanged work. Owners and our legal system recognize that contractors have a right to an adjustment in contract price for owner changes, including the cost associated with materials, labor, lost profit, and increased overhead due to changes. However, the actions of a contractor can impact a project just as easily as those of an owner. A more complex issue is that of determining the cumulative impact that single or multiple change orders may have over the life of a project. This paper presents a method to quantify the cumulative impact on labor productivity for mechanical and electrical construction resulting from changes in the project. Statistical hypothesis testing and correlation analysis were made to identify factors that affect productivity loss resulting from change orders. A multiple regression model was developed to estimate the cumulative impact of change orders. The model includes six significant factors, namely: Percent change, change order processing time, overmanning, percentage of time the project manager spent on the project, percentage of the changes initiated by the owner, and whether the contractor tracks productivity or not. Sensitivity analysis was performed on the model to study the impact of one factor on the productivity loss (%delta). The model can be used proactively to determine the impacts that management decisions will have on the overall project productivity. They may also be used at the conclusion of the project as a dispute resolution tool. It should be noted that every project is unique, so these tools need to be applied with caution. [ABSTRACT FROM AUTHOR]

Spatial joins find all pairs of spatial objects that satisfy a given spatial relationship. In this paper, we present the Transformation-Based Spatial Partition Join algorithm (TSPJ), a new spatial join algorithm that performs join in the transform space without using indexes. Since the existing algorithms deal with extents of spatial objects in the original space, they either need to replicate the spatial objects or have a relatively complex partition structure -- resulting in degrading performance. In contrast, the Transformation-Based Spatial Partition Join transforms objects in the original space into points in the transform space and deals only with points having no extents. The transformation does not incur any additional overhead. Thus, our algorithm has advantages over existing ones in that (1) it obviates the need for replicating spatial objects, and (2) its partition structure is simple. As a result, it always has better performance compared to existing algorithms. Extensive experiments show that the Transformation-Based Spatial Partition. Join improves performance by 19.4∼38.0% over the existing algorithms compared. [ABSTRACT FROM AUTHOR]

Multiple or unusual change orders often cause productivity losses through a “ripple effect” or “cumulative impact” of changes. Many courts and administrative boards recognize that there is cumulative impact above and beyond the change itself. However, determination of the impact and its cost is difficult due to the interconnected nature of construction work and the difficulty in isolating causal factors and their effects. As a result, it is very difficult for owners and contractors to agree on equitable adjustments for the cumulative impact. What is needed is a reliable method (model) to identify and quantify the loss of productivity caused by the cumulative impact of change orders. A number of studies have attempted to quantify the impact of change orders on the project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, traditional regression analysis has shortcomings in dealing with highly correlated multivariable data. Moreover, regression analysis has shown limited success when dealing with many qualitative or noisy input factors. Classification and regression tree methods have the ability to deal with these complex multifactor modeling problems. This study develops decision tree models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders for electrical and mechanical projects. The results show that decision tree models give significantly improved results for classification and quantification compared to traditional statistical methods in the field of construction productivity data analysis, which is characterized by noisiness and uncertainty. [ABSTRACT FROM AUTHOR]

In this paper, the uncertainty of the Monte Carlo code MCNP6 for the sodium-cooled fast reactor (SFR) shielding design is studied. Shielding analysis, which ensures the radiation safety of the core design, is challenging for the Monte Carlo modeling because it is associated with large uncertainties. In order to evaluate the performance of the MCNP6 relative to the shielding design of the SFR, four SFR shielding benchmarks from the Shielding Integral Benchmark Archive Database benchmark suite, i.e. JANUS Phase VIII, SDT12, EURAC_Na and HARMO_Na were selected and analysed. In this research, the weight window variance-reduction technique and the neutron data library ENDF/B-VII.1 were used in the modeling of the benchmark problems. The results and the validation of the MCNP6 models with the available measurement data are presented in this paper. These results contribute to the assessment of radiological protection and shielding design of the Korean Prototype Gen-IV Sodium-cooled Fast Reactor. [ABSTRACT FROM AUTHOR]

A subset of proteins targeted by the N-end rule pathway bear degradation signals called N-degrons, whose determinants include destabilizing N-terminal residues. Our previous work identified mouse UBR1 and UBR2 as E3 ubiquitin ligases that recognize N-degrons. Such E3s are called N-recognins. We report here that while double-mutant UBR1-/- UBR2-/- mice die as early embryos, the rescued UBR1-/- UBR2-/- fibroblasts still retain the N-end rule pathway, albeit of lower activity than that of wild-type fibroblasts. An affinity assay for proteins that bind to destabilizing N-terminal residues has identified, in addition to UBR1 and UBR2, a huge (570 kDa) mouse protein, termed UBR4, and also the 300-kDa UBR5, a previously characterized mammalian E3 known as EDD/hHYD. UBR1, UBR2, UBR4, and UBR5 shared a 70-amino-acid zinc finger-like domain termed the UBR box. The mammalian genome encodes at least seven UBR box-containing proteins, which we propose to call UBR1 to UBR7. UBR1-/- UBR2-/- fibroblasts that have been made deficient in UBR4 as well (through RNA interference) were significantly impaired in the degradation of N-end rule substrates such as the Sindbis virus RNA polymerase nsP4 (bearing N-terminal Tyr) and the human immunodeficiency virus type 1 integrase (bearing N-terminal Phe). Our results establish the UBR box family as a unique class of E3 proteins that recognize N-degrons or structurally related determinants for ubiquitin-dependent proteolysis and perhaps other processes as well. [ABSTRACT FROM AUTHOR]