bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone: The final frontier for Staphylococcus aureus penetration in chronic rhinosinusitis
Authors: Pezato Rogério , Bottura Luciano , de Paula Santos Rodrigo , Voegels Richard Louis , Bachi Andre Luis Lacerda , Gregório Luis Carlos 
Published: July 2013

The superantigenic properties of Staphylococcus aureus have been implicated in increasing the inflammatory process in airway diseases. Local formation of IgE antibodies against staphylococcal enterotoxins by secondary lymphoid tissue in nasal polyps has been demonstrated. Staphylococcus aureus is known to colonize the nasal mucosa, and has been found invading the nasal submucosa and intracellularly. Objective To evaluate the limits of Staphylococcus aureus invasion in the upper airway. Material and methods Inferior turbinate samples from 3 patients without sinus disease, 6 ethmoid samples from patients with chronic rhinosinusitis with nasal polyposis, and 6 ethmoid samples from patients with chronic rhinosinusitis without nasal polyposis were studied. A fluorescein-labeled PNA probe against Staphylococcus aureus was used to test for the presence of the bacterium in bone (after decalcification) and mucosa. Results We found Staphylococcus aureus invading the nasal submucosa in patients with nasal polyposis, but no cases of Staphylococcus aureus positivity in bone. In conclusion, we cannot support the hypothesis of nasal bone as a reservoir for Staphylococcus aureus, releasing massive amounts of staphylococcal enterotoxins and eliciting an inflammatory reaction, as occurs with the nasal mucosa.
β-Keto esters from ketones and ethyl chloroformate: a rapid, general, efficient synthesis of pyrazolones and their antimicrobial, in silico and in vitro cytotoxicity studies
Authors: Ragavan Ramasamy Venkat , Kumar Kalavathi Murugan , Vijayakumar Vijayaparthasarathi , Sarveswari Sundaramoorthy , Ramaiah Sudha , Anbarasu Anand , Karthikeyan Sivashanmugam , Giridharan Periyasamy , Kumari Nalilu Suchetha 
Published: July 2013

Abstract

Background
Pyrazolones are traditionally synthesized by the reaction of β-keto esters with hydrazine and its derivatives. There are methods to synthesize β-keto esters from esters and aldehydes, but these methods have main limitation in varying the substituents. Often, there are a number of methods such as acylation of enolates in which a chelating effect has been employed to lock the enolate anion using lithium and magnesium salts; however, these methods suffer from inconsistent yields in the case of aliphatic acylation. There are methods to synthesize β-keto esters from ketones like caboxylation of ketone enolates using carbon dioxide and carbon monoxide sources in the presence of palladium or transition metal catalysts. Currently, the most general and simple method to synthesize β-keto ester is the reaction of dimethyl or ethyl carbonate with ketone in the presence of strong bases which also requires long reaction time, use of excessive amount of reagent and inconsistent yield. These factors lead us to develop a simple method to synthesize β-keto esters by changing the base and reagent.

Results
A series of β-keto esters were synthesized from ketones and ethyl chloroformate in the presence of base which in turn are converted to pyrazolones and then subjected to cytotoxicity studies towards various cancer cell lines and antimicrobial activity studies towards various bacterial and fungal strains.

Conclusion
The β-keto esters from ethyl chloroformate was successfully attempted, and the developed method is simple, fast and applicable to the ketones having the alkyl halogens, protecting groups like Boc and Cbz that were tolerated and proved to be useful in the synthesis of fused bicyclic and tricyclic pyrazolones efficiently using cyclic ketones. Since this method is successful for different ketones, it can be useful for the synthesis of pharmaceutically important pyrazolones also. The synthesized pyrazolones were subjected to antimicrobial, docking and cytotoxicity assay against ACHN (human renal cell carcinoma), Panc-1 (human pancreatic adenocarcinoma) and HCT-116 (human colon cancer) cell line, and lead molecules have been identified. Some of the compounds are found to have promising activity against different bacterial and fungal strains tested.
Regulation of EGFR trafficking and cell signaling by Sprouty2 and MIG6 in lung cancer cells
Authors: Walsh Alice M. , Lazzara Matthew J. 
Published: July 2013

Summary
The duration and specificity of epidermal growth factor receptor (EGFR) activation and signaling are determinants of cellular decision processes and are tightly regulated by receptor dephosphorylation, internalization and degradation. In addition, regulatory proteins that are upregulated or activated post-transcriptionally upon receptor activation may initiate feedback loops that play crucial roles in spatiotemporal regulation of signaling. We examined the roles of Sprouty2 (SPRY2) and mitogen-inducible gene 6 (MIG6), two feedback regulators of EGFR trafficking and signaling, in lung cancer cells with or without EGFR-activating mutations. These mutations are of interest because they confer unusual cellular sensitivity to EGFR inhibition through a mechanism involving an impairment of EGFR endocytosis. We found that the endocytosis of wild-type and mutant EGFR was promoted by SPRY2 knockdown and antagonized by MIG6 knockdown. SPRY2 knockdown also significantly reduced extracellular signal-regulated kinase (ERK) phosphorylation, EGFR expression, and EGFR recycling. In a cell line expressing mutant EGFR, this effect on ERK led to a marked increase in cell death response to EGFR inhibition. The effects of SPRY2 knockdown on EGFR endocytosis and recycling were primarily the result of the concomitant change in EGFR expression, but this was not true for the observed changes in ERK phosphorylation. Thus, our study demonstrates that SPRY2 and MIG6 are important regulators of wild-type and mutant EGFR trafficking and points to an EGFR expression-independent function of SPRY2 in the regulation of ERK activity that may impact cellular sensitivity to EGFR inhibitors, especially in the context of EGFR mutation.
Damage response of XRCC1 at sites of DNA single strand breaks is regulated by phosphorylation and ubiquitylation after degradation of poly(ADP-ribose)
Authors: Wei Leizhen , Nakajima Satoshi , Hsieh Ching-Lung , Kanno Shinichiro , Masutani Mitsuko , Levine Arthur S. , Yasui Akira , Lan Li 
Published: July 2013

Summary
Single-strand breaks (SSBs) are the most common type of oxidative DNA damage and they are related to aging and many genetic diseases. The scaffold protein for repair of SSBs, XRCC1, accumulates at sites of poly(ADP-ribose) (pAR) synthesized by PARP, but it is retained at sites of SSBs after pAR degradation. How XRCC1 responds to SSBs after pAR degradation and how this affects repair progression are not well understood. We found that XRCC1 dissociates from pAR and is translocated to sites of SSBs dependent on its BRCTII domain and the function of PARG. In addition, phosphorylation of XRCC1 is also required for the proper dissociation kinetics of XRCC1 because (1) phosphorylation sites mutated in XRCC1 (X1 pm) cause retention of XRCC1 at sites of SSB for a longer time compared to wild type XRCC1; and (2) phosphorylation of XRCC1 is required for efficient polyubiquitylation of XRCC1. Interestingly, a mutant of XRCC1, LL360/361DD, which abolishes pAR binding, shows significant upregulation of ubiquitylation, indicating that pARylation of XRCC1 prevents the poly-ubiquitylation. We also found that the dynamics of the repair proteins DNA polymerase beta, PNK, APTX, PCNA and ligase I are regulated by domains of XRCC1. In summary, the dynamic damage response of XRCC1 is regulated in a manner that depends on modifications of polyADP-ribosylation, phosphorylation and ubiquitylation in live cells.
Two potential calmodulin-binding sequences in the ryanodine receptor contribute to a mobile, intra-subunit calmodulin-binding domain
Authors: Huang Xiaojun , Liu Ying , Wang Ruiwu , Zhong Xiaowei , Liu Yingjie , Koop Andrea , Chen S. R. Wayne , Wagenknecht Terence , Liu Zheng 
Published: July 2013

Summary
Calmodulin (CaM), a 16 kDa ubiquitous calcium-sensing protein, is known to bind tightly to the calcium release channel/ryanodine receptor (RyR), and modulate RyR function. CaM binding studies using RyR fragments or synthetic peptides have revealed the presence of multiple, potential CaM-binding regions in the primary sequence of RyR. In the present study, we inserted GFP into two of these proposed CaM-binding sequences and mapped them onto the three-dimensional structure of intact cardiac RyR2 by cryo-electron microscopy. Interestingly, we found that the two potential CaM-binding regions encompassing, Arg3595 and Lys4269, respectively, are in close proximity and are adjacent to the previously mapped CaM-binding sites. To monitor the conformational dynamics of these CaM-binding regions, we generated a fluorescence resonance energy transfer (FRET) pair, a dual CFP- and YFP-labeled RyR2 (RyR2R3595-CFP/K4269-YFP) with CFP inserted after Arg3595 and YFP inserted after Lys4269. We transfected HEK293 cells with the RyR2R3595-CFP/K4269-YFP cDNA, and examined their FRET signal in live cells. We detected significant FRET signals in transfected cells that are sensitive to the channel activator caffeine, suggesting that caffeine is able to induce conformational changes in these CaM-binding regions. Importantly, no significant FRET signals were detected in cells co-transfected with cDNAs encoding the single CFP (RyR2R3595-CFP) and single YFP (RyR2K4269-YFP) insertions, indicating that the FRET signal stemmed from the interaction between R3595–CFP and K4269–YFP that are in the same RyR subunit. These observations suggest that multiple regions in the RyR2 sequence may contribute to an intra-subunit CaM-binding pocket that undergoes conformational changes during channel gating.
Mechanical tuning of the moth ear: distortion-product otoacoustic emissions and tympanal vibrations
Authors: Mora Emanuel C. , Cobo-Cuan Ariadna , Macías Frank , Pérez Martha , Nowotny Manuela , Kössl Manfred 
Published: July 2013

Summary
The mechanical tuning of the ear in the moth E. pugione was investigated by distortion-products otoacoustic emissions (DPOAE) and laser Doppler vibrometry (LDV). DPOAE-audiograms were assessed using a novel protocol that may be advantageous for noninvasive auditory studies in insects. To evoke DPOAE, two-tone stimuli within frequency and level ranges that generated a large matrix of values (960 frequency-level combinations) were used to examine the acoustic space in which the moth tympanum shows its best mechanical and acoustical responses. The DPOAE-tuning curve derived from the response matrix resembles that obtained previously by electrophysiology, is V-shaped, tuned to frequencies between 25 and 45 kHz with low Q10dB values of 1.21 ± 0.26. In addition, while using a comparable stimulation regime, mechanical distortion in the displacement of the moth's tympanal membrane at the stigma was recorded with a laser Doppler vibrometer. The corresponding mechanical vibration audiograms were compared to DPOAE audiograms. Both types of audiograms have comparable shape but most of the mechanical response fields are shifted towards lower frequencies. We showed for the first time in moths that distortion-product otoacoustic emissions have a pronounced analogy in the vibration of the tympanic membrane where they may originate. Our work supports previous studies that point to the stigma (and the internally associated transduction machinery) as an important place of sound amplification in the moth ear, but also suggests a complex mechanical role for the rest of the transparent zone.
Sensitivity of ventilation and brain metabolism to ammonia exposure in rainbow trout,Oncorhynchus mykiss
Authors: Zhang Li , Nawata Michele , Wood Chris 
Published: July 2013

SummaryAmmonia has been documented as a respiratory gas which stimulates ventilation, and is sensed by peripheral neuroepithelial cells (NECs) in the gills in ammoniotelic rainbow trout. However, the hyperventilatory response is abolished in trout chronically exposed (1+ months) to high environmental ammonia (HEA, 250 μmol l-1 (NH4)2SO4). This study investigates whether the brain is involved in the acute sensitivity of ventilation to ammonia, and whether changes in brain metabolism are related to the loss of hyperventilatory responses in trout chronically exposed to HEA (“HEA trout”). Hyperventilation (via increased ventilatory amplitude rather than rate), and increased total ammonia concentration ([TAmm]) in brain tissue were induced in parallel by acute HEA exposure in control trout in a concentration-series experiment (500, 750, 1000 μmol l-1 (NH4)2SO4), but these inductions were abolished in HEA trout. Ventilation was correlated more closely to [TAmm] in brain rather than to [TAmm] in plasma or cerebrospinal fluid (CSF). The close correlation of hyperventilation and increased brain [TAmm] also occurred in control trout acutely exposed to HEA in a time series analysis (500 μmol l-1 (NH4)2SO4 - 15, 30, 45, and 60 min), as well as in a methionine sulfoxamine (MSOX) pre-injection experiment (to inhibit glutamine synthetase, GSase). These correlations consistently suggest that brain [TAmm] is involved in the hyperventilatory responses to ammonia in trout. The MSOX treatments, together with measurements of GSase activity, TAmm, glutamine, and glutamate concentrations in brain tissue, were conducted in both the control and HEA trout. These experiments revealed that GSase plays an important role in transferring ammonia to glutamate to make glutamine in trout brain, thereby attenuating the elevation of brain [TAmm] following HEA exposure, and that glutamate concentration is reduced in HEA trout. The mRNAs for the ammonia channel proteins Rhbg, Rhcg1, and Rhcg2 were expressed in trout brain, and the expression of Rhbg and Rhcg2 increased in HEA trout, potentially as a mechanism to facilitate the efflux of ammonia. In summary, the brain appears to be involved in the sensitivity of ventilation to ammonia, and brain ammonia levels are regulated metabolically in trout.
A conserved fertility signal despite population variation in the cuticular chemical phenotype of the trap-jaw antOdontomachus brunneus
Authors: Smith Adrian A. , Millar Jocelyn G. , Hanks Lawrence M. , Suarez Andrew V. 
Published: July 2013

SummaryContact pheromones in the form of cuticular hydrocarbons are widespread among insects. Eusocial insects present a special challenge for understanding the evolution of the cuticular hydrocarbon profile because this blend is responsible for multiple distinct roles such as nestmate recognition and signalling fertility status. This study investigates these two signalling roles of the hydrocarbon profile in the trap-jaw ant Odontomachus brunneus Patton. We demonstrate that the cuticular hydrocarbon profile is highly variable across populations and provide evidence that these differences are used for nestmate discrimination. Through manipulative experiments we also show that (Z)-9-nonacosene (Z9:C29) is used as a fertility signal and its role is conserved across populations. Our data demonstrate that both fertility and nestmate signalling influence the cuticular hydrocarbon profile and specifically the relative abundance of Z9:C29 on the cuticle of O. brunneus. Our study suggests that natural selection works on the cuticular chemical profile through multiple regulatory pathways, diversifying nestmate signals while conserving fertility signals.
Seasonality influences cuticle melanization and immune defense in a cricket: support for a temperature-dependent immune investment hypothesis in insects
Authors: Fedorka Kenneth M. , Copeland Emily K. , Winterhalter Wade E. 
Published: July 2013

SummaryTo improve thermoregulation in colder environments, insects are expected to darken their cuticles with melanin via the phenoloxidase cascade; a phenomenon predicted by the thermal melanin hypothesis. However, the phenoloxidase cascade also plays a significant role in insect immunity, leading to the additional hypothesis that the thermal environment indirectly shapes immune function via direct selection on cuticle color. Support for the latter hypothesis comes from the cricket Allonemobius socius (Scudder), where cuticle darkness and immune-related phenoloxidase activity increase with latitude. However, thermal environments vary seasonally as well as geographically, suggesting that seasonal plasticity in immunity may also exist. Although seasonal fluctuations in vertebrate immune function are common (due to flux in breeding or resource abundance), seasonality in invertebrate immunity has not been widely explored. We addressed this possibility by rearing crickets in simulated summer and fall environments and assayed their cuticle color and immune function. Prior to estimating immunity, crickets were placed in a common environment to minimize metabolic rate differences. Fall-like individuals exhibited darker cuticles, a greater phenoloxidase activity and greater resistance to the bacteria Serratia marcescens. These data support the hypothesis that changes in the thermal environment modify cuticle color, which indirectly shapes immune investment through pleiotropy. This hypothesis may represent a widespread mechanism governing immunity in numerous systems, considering that most insects operate in seasonally and geographically variable thermal environments.
Impacts of temperature on performance in two species of South African dwarf chameleons,Bradypodion pumilumandB. occidentale
Authors: Segall Marion A. , Tolley Krystal A. , Vanhooydonck Bieke , Measey John G. , Herrel Anthony 
Published: July 2013

SummaryTemperature is an extrinsic factor which influences reptile behavior given that their physiology is dependent on environmental temperature. Understanding the impact of temperature on performance traits is important as it may affect the ecology and fitness of ectothermic animals such as reptiles. Here we examine the temperature dependence of performance in two species of South African Dwarf chameleon (Bradypodion), a semi-arid and a mesic adapted species. Ecologically relevant performance traits were tested at different temperatures to evaluate their thermal dependence and temperature-performance breadths for 80% and 90% of each performance trait were calculated. Our results show distinct differences in the thermal dependence of speed versus force-related performance traits. Moreover, our results show that the semi-arid species is better adapted to higher temperatures and as such has better chances to cope with the predicted increases in temperature. The mesic-adapted species seems to be more sensitive to an increase in temperature and could therefore potentially be threatened by predicted future climate change. However, further studies investigating the potential for acclimation in chameleons are needed to better understand how animals may respond to predicted future climate change.
A New Family of Multiple-Bond Compounds between Heavier Group 14 Elements
Authors: Sasamori Takahiro , Tokitoh Norihiro 
Published: July 2013

Abstract
On the basis of fundamental research on the chemistry of π-electron systems between heavier main group elements, it was found that such π-electron systems should exhibit higher HOMO and lower LUMO as compared with those between second row elements. That is, the π-electron systems between heavier main group elements are possibly good electron acceptors, good electron donors, and good electron transporters. From the viewpoint of creation of novel π-electron systems and fundamental research on such π-electron system of heavier main group elements, a novel type of doubly and triply bonded compounds between heavier group 14 elements was successfully synthesized by taking advantage of kinetic stabilization using bulky substituents. The new family of multiple-bond compounds obtained here are (i) 1,2-dibromodimetallenes, Ar(Br)E=E(Br)Ar (E = Si, Ge, Ar = bulky aryl group), as a possible building block of a π-bond between heavier group 14 elements, (ii) 1,2-diaryldimetallynes (ArE≡EAr, E = Si, Ge) as a unique and reactive π-bonding, and (iii) 1,2-dihydrodisilenes, Ar(H)Si=Si(H)Ar, as a simple disilene. The fundamental physical and chemical properties of the newly obtained compounds have been revealed, showing that such π-electron systems between heavier group 14 elements should be completely different from those of carbon systems and should be of great interest as unique π-systems. Thus, the compounds obtained here are not only “stable multiple bonds” but also possible candidates for novel material species.
Practical and Scalable Syntheses of Substituted Ketene Dithioacetal Monoxides
Authors: Murakami Kei , Yorimitsu Hideki , Osuka Atsuhiro 
Published: July 2013

Abstract
Practical syntheses of substituted ketene dithioacetal monoxides (KDMs) from the corresponding aldehydes or ethyl trifluoroacetate are described. Newly developed procedures are scalable and versatile to provide aryl-, alkyl-, and trifluoromethyl-substituted KDMs in gram scales.
Synthesis of Methyl epi-Anhydroquinate Utilizing [2,3]-Sigmatropic Rearrangement of Iodosoalkene
Authors: Inomata Sho , Ueda Minoru , Sugai Takeshi , Shoji Mitsuru 
Published: July 2013

Abstract
Sigmatropic rearrangement has been utilized for stereoselective syntheses of structurally complicated natural products because of its high stereoselectivity and reactivity. Quinic acid (1) and its epimer 2 are versatile building blocks for the preparation of various bioactive compounds. We report the synthesis of methyl epi-anhydroquinate 3 via the [2,3]-sigmatropic rearrangement of iodosoalkene.
Treatment of Landfill Leachate by Microwave-Fenton Oxidation Process Catalyzed by Fe2+ Loaded on GAC
Authors: Ding Zhan , Guan Weisheng 
Published: July 2013

Abstract
Landfill leachate is one kind of the most harmful types of high-concentration organic waste water. The effective processing method is necessary to improve the treating efficiency of landfill leachate. In this study, the microwave-Fenton oxidation process was conducted to treat aged landfill leachate with the catalytic effect of Fe2+ loaded on granular activated carbon (GAC). The removal ratios of chemical oxygen demand (COD) and NH3-N were adopted as the indexes to analyze the influence of several factors, like the amount of loading Fe2+, the GAC dosage, the microwave irradiation time, the microwave power, the H2O2 dosage, and the pH value of the water sample on the efficiency of the Fenton reagent oxidation to landfill leachate. The corresponding microanalysis and kinetics were also performed. The results indicate that microwave energy can enhance the Fenton oxidation reaction and promote colloidal flocculation in the leachate. The removal ratio of COD is mainly because of oxidation, whereas that of NH3-N is mainly because of the flocculation and adsorption. Under the optimal conditions, loading Fe2+ amount = 33.32 mg/g, GAC dosage = 10 g/l, microwave power = 720 W, microwave irradiation time = 30 min, H2O2 (concentration of 30 %) dosage = 0.10 mol/l, and initial pH value = 3, the maximum remova1 ratios of COD and NH3-N are, respectively, up to 93.01 % and 85.76 %. The characteristic peaks of the organic pollutants in treated landfill leachate disappear or significantly weaken, which means that the proposed process is effective. In addition, according to the experiment results, a kinetics model of microwave-Fenton oxidation reaction is established preliminarily.