bluuebunny/crossref_metadata_2025_split huggingface dataset:
Components of Sleep Quality and Sleep Fragmentation in Rheumatoid Arthritis and Osteoarthritis
Authors: Taylor‐Gjevre R.M. , Gjevre J.A. , Nair B. , Skomro R. , Lim H.J. 
Published: June 2011

AbstractObjectivesPoor sleep is increasingly recognized as contributing to a decreased quality of life, increased morbidity/mortality and heightened pain perception. The purpose of the present study was to assess components of sleep quality and self‐identified contributors to sleep fragmentation in rheumatoid arthritis (RA) and osteoarthritis (OA) patient populations.MethodsConsecutive RA and OA clinic patients were invited to participate in a self‐administered questionnaire study which included the validated multi‐domain Pittsburgh Sleep Quality Index (PSQI), visual analogue scales for pain, fatigue, global functioning, modified Health Assessment Questionnaire (mHAQ), stress scores, the Centre for Epidemiologic Studies–Depression (CES–D) score, the 36‐item short form (SF‐36) quality of life measure, the Rheumatoid Arthritis Disease Activity Index (RADAI), the Epworth Sleepiness Scale (ESS), Berlin score for obstructive sleep apnoea (OSA) risk and the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria.ResultsThe study population included 145 RA and 78 OA patients. PSQI global scores were >5 in 62% of RA and 67% of OA patients. Multivariate analysis identified global functioning and the CES–D to be independent predictors for higher global PSQI scores in RA patients, whereas in OA patients predictors were the mHAQ and SF‐36 mental component summary. Abnormalities in subjective sleep assessment, sleep latency, sleep duration, sleep efficiency, daytime dysfunction and increased sleep‐aid medication use were observed in both populations. The most common abnormality reported by both RA and OA patients was increased sleep fragmentation. The most frequent self‐identified cause for sleep disturbance was ‘need to use the washroom’ by 51% of RA and 49% of OA patients, and, second most common, ‘pain’ was identified as a cause for awakening by 33% of RA and 45% of OA patients.ConclusionsA high prevalence of abnormal sleep quality in both RA and OA patient populations was observed. The most common abnormality was sleep fragmentation, with an increased sleep disturbance score. ‘Need to use the washroom’ and ‘pain’ were the most common self‐identified reasons for awakening from sleep. A review of sleep hygiene, optimization of urological status, and rheumatological disease symptomatic control may prove beneficial in terms of sleep health. Copyright © 2011 John Wiley & Sons, Ltd.
Feasibility of contact heat evoked potentials for detection of diabetic neuropathy
Authors: Wong Man‐Chun , Chung Joanne W.Y. 
Published: June 2011

AbstractIntroduction: The involvement of small myelinated fibers in the early stages of diabetic neuropathy (DN) has been suggested, but few objective methods can identify minimal neuropathy. The purpose of this study was to determine whether there are differences in contact heat evoked potential (CHEP) parameters between healthy adults and diabetics with and without lower limb symptoms. Methods: CHEP was recorded at the midline channels. A peak stimulating temperature of 51°C was applied to the dorsum of the foot and at a point 10 cm proximal to the lateral malleolus. Results: There was a significant difference in N1–P1 amplitude in the three groups after stimulation of the dorsum of the foot (P = 0.028) and the point 10 cm proximal to the lateral malleolus (P = 0.006). Discussion: CHEP can help to detect early A‐delta fiber damage in diabetic patients with minimal neuropathy. Muscle Nerve, 2011
Does the severity of the LGMD2A phenotype in compound heterozygotes depend on the combination of mutations?
Authors: Sáenz Amets , Ono Yasuko , Sorimachi Hiroyuki , Goicoechea Maria , Leturcq France , Blázquez Lorea , García‐Bragado Federico , Marina Alberto , Poza Juan José , Azpitarte Margarita , Doi Naoko , Urtasun Miguel , Kaplan Jean‐Claude , De Munain Adolfo López 
Published: June 2011

AbstractIntroduction: Limb‐girdle muscular dystrophy type 2A (LGMD2A) is caused by a deficiency of calpain‐3/p94. Although the symptoms in most LGMD2A patients are generally homogeneous, some variation in the severity and progression of the disease has been reported. Methods: We describe 2 patients who carry the same combination of compound heterozygous mutations (pG222R/pR748Q) and whose symptoms are exceptionally benign compared to homozygotes with each missense mutation. Results: The benign phenotype observed in association with the combined pG222R and pR748Q mutations suggested that it may result from a compensatory effect of compound heterozygosity rather than the individual mutations themselves. Our analyses revealed that these two mutations exert different effects on the protease activity of calpain‐3, suggesting “molecular complementation” in these patients. Conclusion: We propose several hypotheses to explain how this specific combination of mutations may rescue the normal proteolytic activity of calpain‐3, resulting in an exceptionally benign phenotype. Muscle Nerve, 2011
Clinical and pathological heterogeneity in late‐onset partial merosin deficiency
Authors: Rajakulendran Sanjeev , Parton Matt , Holton Janice L. , Hanna Michael G. 
Published: June 2011

AbstractMutations in the LAMA2 gene result in a complete loss of merosin and underlie a severe congenital type of muscular dystrophy (MDC1A).We investigated the clinical, genetic, and histological basis of late‐onset muscular dystrophy in one family. The proband and her affected brother exhibited late‐onset predominantly proximal muscle weakness. In addition, the proband experienced seizures. Magnetic resonance imaging of her brain demonstrated white‐matter abnormalities. Sequencing of LAMA2 identified two new heterozygous point mutations in the two affected members. Muscle histology demonstrated dystrophic features, rimmed vacuoles, and partial loss of laminin α immunoreactivity. Partial merosin deficiency can present with a mild, late‐onset limb‐girdle–type pattern of weakness, with or without epilepsy, and pathologically may exhibit features observed in inclusion‐body myopathy. Muscle Nerve, 2011
The role of calcium ions in the stability and instability of a thermolysin‐like protease
Authors: Eijsink V. G. H. , Matthews B. W. , Vriend G. 
Published: June 2011

AbstractThermolysin and other secreted broad‐specificity proteases, such as subtilisin or alpha‐lytic protease, are produced as pre‐pro‐proteins that stay at least partially unfolded while in the cytosol. After secretion, the pro‐proteases fold to their active conformations in a process that includes the autolytic removal of the pro‐peptide. We review the life cycle of the thermolysin‐like protease from Bacillus stearothermophilus in light of the calcium dependent stability and instability of the N‐terminal domain. The protease binds calcium ions in the regions that are involved in the autolytic maturation process. It is generally assumed that the calcium ions contribute to the extreme stability of the protease, but experimental evidence for TLP‐ste indicates that at least one of the calcium ions plays a regulatory role. We hypothesize that this calcium ion plays an important role as a switch that modulates the protease between stable and unstable states as appropriate to the biological need.
Intermolecular versus intramolecular interactions of the vinculin binding site 33 of talin
Authors: Yogesha S. D. , Sharff A. , Bricogne G. , Izard T. 
Published: June 2011

AbstractThe cytoskeletal proteins talin and vinculin are localized at cell‐matrix junctions and are key regulators of cell signaling, adhesion, and migration. Talin couples integrins via its FERM domain to F‐actin and is an important regulator of integrin activation and clustering. The 220 kDa talin rod domain comprises several four‐ and five‐helix bundles that harbor amphipathic α‐helical vinculin binding sites (VBSs). In its inactive state, the hydrophobic VBS residues involved in binding to vinculin are buried within these helix bundles, and the mechanical force emanating from bound integrin receptors is thought necessary for their release and binding to vinculin. The crystal structure of a four‐helix bundle of talin that harbors one of these VBSs, coined VBS33, was recently determined. Here we report the crystal structure of VBS33 in complex with vinculin at 2 Å resolution. Notably, comparison of the apo and vinculin bound structures shows that intermolecular interactions of the VBS33 α‐helix with vinculin are more extensive than the intramolecular interactions of the VBS33 within the talin four‐helix bundle.
An improved synthesis of (2S, 4S)‐ and (2S, 4R)‐2‐amino‐4‐methyldecanoic acids: assignment of the stereochemistry of culicinins
Authors: Zhang Wei , Ding Ning , Li Yingxia 
Published: June 2011

AbstractAn improved synthesis of (2S, 4S)‐ and (2S, 4R)‐2‐amino‐4‐methyldecanoic acids was accomplished using a glutamate derivative as starting material and Evans' asymmetric alkylation as the decisive step. The NMR data of the two diastereomers were measured and compared with those of the natural product. As a result, the stereochemistry of this novel amino acid unit in culicinins was assigned as (2S, 4R). Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Cooperativity network of Trp‐cage miniproteins: probing salt‐bridges
Authors: Rovó Petra , Farkas Viktor , Hegyi Orsolya , Szolomájer‐Csikós Orsolya , Tóth Gábor K. , Perczel András 
Published: June 2011

AbstractTrp‐cage miniprotein was used to investigate the role of a salt‐bridge (Asp9–Arg16) in protein formation, by mutating residues at both sides, we mapped its contribution to overall stability and its role in folding mechanism. We found that both of the above side‐chains are also part of a dense interaction network composed of electrostatic, H‐bonding, hydrophobic, etc. components. To elucidate the fold stabilizing effects, we compared and contrasted electronic circular dichroism and NMR data of miniproteins equipped with a salt‐bridge with those of the salt‐bridge deleted mutants. Data were acquired both in neutral and in acidic aqueous solutions to decipher the pH dependency of both fully and partially charged partners. Our results indicate that the folding of Trp‐cage miniproteins is more complex than a simple two‐state process as we detected an intermediate state that differs significantly from the native fold. The intermediate formation is related to the salt‐bridge stabilization; in the miniprotein variants equipped with salt‐bridge the population of the intermediate state at acidic pH is significantly higher than it is for the salt‐bridge deleted mutants. In this molecular framework Arg16 stabilizes more than Asp9 does, because of its higher degree of 3D‐fold cooperation. In conclusion, the Xxx$^{9} \leftrightarrow$Yyy16 salt‐bridge is not an isolated entity of this fold; rather it is an integrated part of a complex interaction network. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Synthetic studies toward labionin, a new α,α‐disubstituted amino acid from type III lantibiotic labyrinthopeptin A2
Authors: Sambeth Georg M. , Süssmuth Roderich D. 
Published: June 2011

AbstractThe labyrinthopeptins are a new class of lantibiotics containing two identical quaternary α,α‐disubstituted amino acids, named labionin (Lab). The synthetic formation of this unique structural feature represents the key step in the total synthesis of these polycyclic peptides. In this report we describe the synthesis of an orthogonally protected α,α‐disubstituted amino acid building block serving as labionin precursor for the future assembly of labyrinthopeptin A2 and of other labyrinthopeptin derivatives. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Creatinyl amino acids—new hybrid compounds with neuroprotective activity
Authors: Burov Sergey , Leko Maria , Dorosh Marina , Dobrodumov Anatoliy , Veselkina Olga 
Published: June 2011

AbstractProlonged oral creatine administration resulted in remarkable neuroprotection in experimental models of brain stroke. However, because of its polar nature creatine has poor ability to penetrate the blood–brain barrier (BBB) without specific creatine transporter (CRT). Thus, synthesis of hydrophobic derivatives capable of crossing the BBB by alternative pathway is of great importance for the treatment of acute and chronic neurological diseases including stroke, traumatic brain injury and hereditary CRT deficiency. Here we describe synthesis of new hybrid compounds—creatinyl amino acids, their neuroprotective activity in vivo and stability to degradation in different media. The title compounds were synthesized by guanidinylation of corresponding sarcosyl peptides or direct creatine attachment using isobutyl chloroformate method. Addition of lipophilic counterion (p‐toluenesulfonate) ensures efficient creatine dissolution in DMF with simultaneous protection of guanidino group towards intramolecular cyclization. It excludes the application of expensive guanidinylating reagents, permits to simplify synthetic procedure and adapt it to large‐scale production. The biological activity of creatinyl amino acids was tested in vivo on ischemic stroke and NaNO2‐induced hypoxia models. One of the most effective compounds—creatinyl‐glycine ethyl ester increases life span of experimental animals more than two times in hypoxia model and has neuroprotective action in brain stroke model when applied both before and after ischemia. These data evidenced that creatinyl amino acids can represent promising candidates for the development of new drugs useful in stroke treatment. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Two antimicrobial and nematicidal peptides derived from sequences encoded Picea sitchensis
Authors: Liu Rui , Mu Lixian , Liu Huan , Wei Lin , Yan Tianhua , Chen Ming , Zhang Keyun , Li Jianxu , You Dewen , Lai Ren 
Published: June 2011

AbstractTwo antimicrobial peptides (piceain 1 and 2) derived from sequences encoded Picea sitchensis are identified. Their amino acid sequences are KSLRPRCWIKIKFRCKSLKF and RPRCWIKIKFRCKSLKF, respectively. One intra‐molecular disulfide bridge is formed by these two half‐cysteines in both piceain 1 and 2. Antimicrobial activities of synthesized piceains against several kinds of microorganisms were tested. They showed antimicrobial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and fungus Candida albicans but little antimicrobial activity against Bacillus subtilis. The results of nematicidal test showed they exerted strong nematicidal activities against Caenorhabditis elegans, following exposure for 5 h at concentrations as low as 10 µg/ml. They had weak hemolytic abilities against human and rabbit red cells. At the concentration of 250 µg/ml, they induced red cell hemolysis of less than 5%. Circular dichroism spectra of the two antimicrobial peptides were investigated in several solutions. Their main secondary structure components are β‐sheet and random. The current work provides a novel family of antimicrobial and nematicidal peptides with unique disulfided loop containing nine amino acid residues. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Increasing the hydrolysis constant of the reactive site upon introduction of an engineered Cys14Cys39bond into the ovomucoid third domain from silver pheasant
Authors: Hemmi Hikaru , Kumazaki Takashi , Kojima Shuichi , Yoshida Takuya , Ohkubo Tadayasu , Yokosawa Hideyoshi , Miura Kin‐ichiro , Kobayashi Yuji 
Published: June 2011

AbstractP14C/N39C is the disulfide variant of the ovomucoid third domain from silver pheasant (OMSVP3) introducing an engineered Cys14Cys39bond near the reactive site on the basis of the sequence homology between OMSVP3 and ascidian trypsin inhibitor. This variant exhibits a narrower inhibitory specificity. We have examined the effects of introducing a Cys14Cys39bond into the flexible N‐terminal loop of OMSVP3 on the thermodynamics of the reactive site peptide bond hydrolysis, as well as the thermal stability of reactive site intact inhibitors. P14C/N39C can be selectively cleaved byStreptomyces griseusprotease B at the reactive site of OMSVP3 to form a reactive site modified inhibitor. The conversion rate of intact to modified P14C/N39C is much faster than that for wild type under any pH condition. The pH‐independent hydrolysis constant (Khyd°) is estimated to be approximately 5.5 for P14C/N39C, which is higher than the value of 1.6 for natural OMSVP3. The reactive site modified form of P14C/N39C is thermodynamically more stable than the intact one. Thermal denaturation experiments using intact inhibitors show that the temperature at the midpoint of unfolding at pH 2.0 is 59 °C for P14C/N39C and 58 °C for wild type. There have been no examples, except P14C/N39C, where introducing an engineered disulfide causes a significant increase inKhyd°, but has no effect on the thermal stability. The site‐specific disulfide introduction into the flexible N‐terminal loop of natural Kazal‐type inhibitors would be useful to further characterize the thermodynamics of the reactive site peptide bond hydrolysis. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
β‐Amino acids containing peptides and click‐cyclized peptide as β‐turn mimics: a comparative study with ‘conventional’ lactam‐ and disulfide‐bridged hexapeptides
Authors: Larregola Maud , Lequin Olivier , Karoyan Philippe , Guianvarc'h Dominique , Lavielle Solange 
Published: June 2011

AbstractThe increasing interest in click chemistry and its use to stabilize turn structures led us to compare the propensity for β‐turn stabilization of different analogs designed as mimics of the β‐turn structure found in tendamistat. The β‐turn conformation of linear β‐amino acid‐containing peptides and triazole‐cyclized analogs were compared to ‘conventional’ lactam‐ and disulfide‐bridged hexapeptide analogs. Their 3D structures and their propensity to fold in β‐turns in solution, and for those not structured in solution in the presence of α‐amylase, were analyzed by NMR spectroscopy and by restrained molecular dynamics with energy minimization. The linear tetrapeptide Ac‐Ser‐Trp‐Arg‐Tyr‐NH2 and both the amide bond‐cyclized, c[Pro‐Ser‐Trp‐Arg‐Tyr‐D‐Ala] and the disulfide‐bridged, Ac‐c[Cys‐Ser‐Trp‐Arg‐Tyr‐Cys]‐NH2 hexapeptides adopt dominantly in solution a β‐turn conformation closely related to the one observed in tendamistat. On the contrary, the β‐amino acid‐containing peptides such as Ac‐(R)‐β3‐hSer‐(S)‐Trp‐(S)‐β3‐hArg‐(S)‐β3‐hTyr‐NH2, and the triazole cyclic peptide, c[Lys‐Ser‐Trp‐Arg‐Tyr‐βtA]‐NH2, both specifically designed to mimic this β‐turn, do not adopt stable structures in solution and do not show any characteristics of β‐turn conformation. However, these unstructured peptides specifically interact in the active site of α‐amylase, as shown by TrNOESY and saturation transfer difference NMR experiments performed in the presence of the enzyme, and are displaced by acarbose, a specific α‐amylase inhibitor. Thus, in contrast to amide‐cyclized or disulfide‐bridged hexapeptides, β‐amino acid‐containing peptides and click‐cyclized peptides may not be regarded as β‐turn stabilizers, but can be considered as potential β‐turn inducers. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
The assessment of the equatorial counterpart of the quasi‐geostrophic model
Authors: Mohebalhojeh Ali R. , Theiss Jürgen 
Published: June 2011

AbstractThe equatorial counterpart of the quasi‐geostrophic model that has recently been derived and is referred to as the equatorial balanced model is compared to the shallow water equations. This comparison allows for the assessment of the accuracy with which the equatorial balanced model approximates the low‐frequency, or balanced, component of the dynamics described by the shallow water equations. In order to be able to consider fully nonlinear dynamics, numerical implementations of both models are developed for a zonally periodic channel on the equatorial β‐plane using the Contour‐Advective Semi‐Lagragian (CASL) algorithm. The CASL algorithm is chosen because it has beneficial qualities compared to other algorithms by taking full advantage of the property that both models materially conserve potential vorticity. The particular dynamics chosen for the assessment is that of an initially unstable westward flow that freely evolves. The assessment also shows that the accuracy of the equatorial balanced model is comparable to that of the quasi‐geostrophic model outside the equatorial region and to that of one of the most accurate balanced models with its balance relations linearized in the equatorial region. Copyright © 2011 Royal Meteorological Society
Hydrogen bond and σ‐hole interaction in M2C=S···HCN (M = H, F, Cl, Br, HO, H3C, H2N) complex: Dual roles of C=S group and substitution effect
Authors: Jing Bo , Li Qingzhong , Gong Baoan , Li Ran , Liu Zhenbo , Li Wenzuo , Cheng Jianbo , Sun Jiazhong 
Published: June 2011

AbstractAn ab initio computational study of the dual functions of CS group in the M2CS···HCN (M = H, F, Cl, Br, HO, H3C, H2N) complex has been performed at the MP2(Full)/aug‐cc‐pVTZ level. The CS group can act as both the electron donor and acceptor, thus two minima complexes were found for each molecular pairs. The interaction energy of hydrogen bond in the F, Cl, or Br substituted complexes is less negative than that in the corresponding H2CS one, while the interaction energy of the σ‐hole interaction is more negative. The OH substitution weakens the hydrogen bond, whereas the H3C and H2N substitution strengthens it. The σ‐hole interaction in the HO, H3C, and H2N complexes is very weak. The substitution effect has been understood with electrostatic induction and conjugation effects. The energy decomposition analysis has been performed for the halogen‐substituted complexes. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012.
PHYSICAL AND PLANT COMMUNITY CONTROLS ON NITROGEN AND PHOSPHORUS LEACHING FROM IMPOUNDED RIVERINE WETLANDS FOLLOWING DAM REMOVAL
Authors: Riggsbee J. Adam , Wetzel R. , Doyle M. W. 
Published: June 2011

ABSTRACTDam removal has emerged as a critical issue in water resources engineering and management. Of particular concern in many regions of the USA is the effect of dam removal on downstream water quality and potential methods of decreasing sediment and nutrient loading to downstream reaches. Rapid revegetation of reservoir sediments has been suggested as a means of reducing the impact of dam removal, although little data exist about the role of vegetation in controlling the downstream release of sediment or nutrients.This study investigated an impounded riverine wetland complex on the Little River, North Carolina, before and after the removal of a low‐head dam. We quantified the leaching of interstitial nitrogen (N) and phosphorus (P) to the adjacent river channel during reservoir dewatering and, through experimental manipulations, isolated the difference between physical (soil) and biological (plant) controls on N and P leaching from dewatering impoundment sediments. We found that the rate and the quantity of N and P leaching from impounded dewatering sediment are predominately controlled by sediment porosity and specific yield. Although vegetation controls on N and P leaching were statistically significant during the first growing season following dam removal, vegetation is likely to be more important as a long‐term control on sediment and nutrient loads. Our results suggest that the initial release of N and P from a dewatered reservoir will be difficult to control but that vegetation may play an important long‐term role. Copyright © 2011 John Wiley & Sons, Ltd.