bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signal peptide of eosinophil cationic protein upregulates transforming growth factor‐alpha expression in human cells
Authors: Chang Hao‐Teng , Kao Yu‐Lin , Wu Chia‐Mao , Fan Tan‐chi , Lai Yiu‐Kay , Huang Kai‐Ling , Chang Yuo‐Sheng , Tsai Jaw‐Ji , Chang Margaret Dah‐Tsyr 
Published: October 2006

AbstractEosinophil cationic protein (ECP) is a major component of eosinophil granule protein that is used as a clinical bio‐marker for asthma and allergic inflammatory diseases. Previously, it has been reported that the signal peptide of human ECP (ECPsp) inhibits the cell growth of Escherichia coli (E. coli) and Pichia pastoris (P. pastoris), but not mammalian A431 cells. The inhibitory effect is due to the lack of human signal peptide peptidase (hSPP), a protease located on the endoplasmic reticulum (ER) membrane, in the lower organisms. In this study, we show that the epidermal growth factor receptor (EGFR) is upregulated by the exogenous ECPsp‐eGFP as a result of the increased expression of the transforming growth factor‐alpha (TGF‐α) at both transcriptional and translational levels in A431 and HL‐60 clone 15 cell lines. Furthermore, the N‐terminus of ECPsp fragment generated by the cleavage of hSPP (ECPspM1‐G17) gives rise to over threefold increase of TGF‐α protein expression, whereas another ECPsp fragment (ECPspL18‐A27) and the hSPP‐resistant ECPsp (ECPspG17L) do not show similar effect. Our results indicate that the ECPspM1‐G17 plays a crucial role in the upregulation of TGF‐α, suggesting that the ECPsp not only directs the secretion of mature ECP, but also involves in the autocrine system. J. Cell. Biochem. 100: 1266–1275, 2007. © 2006 Wiley‐Liss, Inc.
QTAIM n‐center delocalization indices as descriptors of aromaticity in mono and poly heterocycles
Authors: Mandado Marcos , González‐Moa María J. , Mosquera Ricardo A. 
Published: October 2006

AbstractThe implementation of the n‐center electron delocalization indices, n‐DIs, and n‐order electron localization indices, n‐LIs, within the framework of the quantum theory of atoms in molecules, QTAIM, is performed. n‐DIs are shown to be very useful to study the local aromaticity in monocyclic and polycyclic compounds. Total and π n‐DIs from n = 4 to 7 were computed for a series of typical 4, 5, 6, and 7‐center aromatic and antiaromatic rings. For n ≥ 5 the π n‐DI accounts for the 95% of the total n‐DI and can be employed alone to measure the aromaticity. A scaling factor on the n‐DIs is required in order to compare the aromaticity of [5c‐6e] and [6c‐6e] rings, the same correction allows to estimate the relative aromatic stabilization of polycyclic compounds using the sum of its values for individual rings. This is called Effective Scaled Electron Delocalization, ESED. The comparison with other aromaticity indices reflects a good correlation between ESED and both resonance energies, and HOMA indices. The most important differences between scaled π n‐DIs and NICS(0) indices are found for compounds that contain rings with different number of centers or π electrons. © 2006 Wiley Periodicals, Inc. J Comput Chem, 2007
A study of precipitation variability in the Duero Basin (Iberian Peninsula)
Authors: Caramelo Liliana , Orgaz M. Dolores Manso 
Published: October 2006

AbstractSpatial and temporal average behaviour of winter precipitation in the Duero basin (DB) were analysed for 1958–1993. Monthly observed data (observed data) from 34 weather stations and a subset of daily precipitation data from the NCEP/NCAR reanalysis project (reanalysis data) were used.The spatial variability of winter precipitation was examined using principal component analysis (PCA) for both types of data. The winter precipitation fields are well represented by the first three principal components (PC), which describe 81% and 87% of the total variance for the observed and reanalysis data, respectively. The relationship between the three leading PCs and circulation patterns was also investigated. The PC1 is related to the North Atlantic Pattern (NAO), East Atlantic Pattern (EA) and Pacific North American Pattern (PNA). The PC2 is related to the East Atlantic/West Russia Pattern (EAWR), while the PC3 depends mainly on Scandinavia Pattern (SCAND) influences.The reanalysis data were used to calculate a 10‐day period to study the intra‐annual variation (S‐mode of PCA) and the spatial distribution of those precipitation amounts during the year (T‐mode of PCA). For the intra‐annual variation of precipitation, two modes statistically significant were obtained. The first mode was characterized by a broad maximum that extended from mid October to early April, and a minimum that extended from early May to September. The second mode exhibited two maxima and a minimum. The first maximum occurred in late February and the second maximum extended from early April to June. The minimum extended from mid July to early February. For the spatial distribution of precipitation, we obtained three patterns. The ‘winter’ pattern, which showed a maximum over the western area, the ‘spring’ pattern with a maximum over the eastern area, and the ‘autumn’ with a maximum over the easternmost edge of the basin. Copyright © 2006 Royal Meteorological Society.
Determination of diphenylether herbicides in water samples by solid‐phase microextraction coupled to liquid chromatography
Authors: Sheu Hong‐Li , Sung Yu‐Hsiang , Melwanki Mahaveer B. , Huang Shang‐Da 
Published: October 2006

AbstractSolid‐phase microextraction (SPME) coupled to LC for the analysis of five diphenylether herbicides (aclonifen, bifenox, fluoroglycofen‐ethyl, oxyfluorfen, and lactofen) is described. Various parameters of extraction of analytes onto the fiber (such as type of fiber, extraction time and temperature, pH, impact of salt and organic solute) and desorption from the fiber in the desorption chamber prior to separation (such as type and composition of desorption solvent, desorption mode, soaking time, and flush‐out time) were studied and optimized. Four commercially available SPME fibers were studied. PDMS/divinylbenzene (PDMS/DVB, 60 μm) and carbowax/templated resin (CW/TPR, 50 μm) fibers were selected due to better extraction efficiencies. Repeatability (RSD, <7%), correlation coefficient (>0.994), and detection limit (0.33–1.74 and 0.22–1.94 ng/mL, respectively, for PDMS/DVB and CW/TPR) were investigated. Relative recovery (81–104% for PDMS/DVB and 83–100% for CW/TPR fiber) values have also been calculated. The developed method was successfully applied to the analysis of river water and water collected from a vegetable garden.
Determination of the interconversion energy barrier of 2,3‐pentadienedioic acid enantiomers by HPLC. 2. On‐column interconversion
Authors: Mydlová Janka , Fedurcová Andrea , Lehotay Jozef , Krupcík Jan , Májek Pavel , Armstrong Daniel W. , Lingfeng He Brian , Cotton F. Albert 
Published: October 2006

AbstractIn this paper, an HPLC method is used to determine the enantiomerization barrier of 2,3‐pentadienedioic acid enantiomers. The racemate of 2,3‐pentadienedioic acid was separated by HPLC on a chiral CHIROBIOTIC T column with a 90:10 (100:0.5:0.5 MeOH/HOAc/TEA)/H2O mobile phase. Peak areas of enantiomers prior to (A(+)0, A(–)0) and after the separation (A(+), A(–)), were used for calculation of the rate constants and the enantiomerization barrier, as determined by computer‐assisted peak deconvolution of the peak clusters on the chromatograms. The kinetic equation for irreversible reactions was used to determine the apparent enantiomerization rate constants and the interconversion energy barrier. The dependence of the apparent enantiomerization barrier (ΔG1app, ΔG–1app) on temperature was used to determine the apparent activation enthalpy (ΔH1app, ΔH–1app) and entropy (ΔS1app, ΔS–1app) for the interconversion of 2,3‐pentadienedioic acid enantiomers, where the coefficients 1 and –1 designate the interconversions (+) → (–) and (–) → (+), respectively.
HPLC–MS characterization of cyclo‐statherin Q‐37, a specific cyclization product of human salivary statherin generated by transglutaminase 2
Authors: Cabras Tiziana , Inzitari Rosanna , Fanali Chiara , Scarano Emanuele , Patamia Maria , Sanna Maria T. , Pisano Elisabetta , Giardina Bruno , Castagnola Massimo , Messana Irene 
Published: October 2006

AbstractIn the present study the analytical potential of HPLC–MS/MS was utilized for the structural characterization of a post‐translational modification of statherin. Human salivary statherin (Mav 5380.0 ± 0.3 Da) is transformed by the action of transglutaminase 2 into a cyclic derivative with an average molecular mass of 5363.0 ± 0.3 Da. The intra‐molecular bridge is generated by the loss of an ammonia molecule between the unique lone‐pair donating nucleophile Lys‐6 and one acceptor among the seven glutamine residues of statherin. Digestion of the cyclic derivative with chymotrypsin, proteinase K, and carboxypeptidase Y, monitored by HPLC–electrospray ionization‐ion trap‐mass spectrometric analysis, demonstrated that cyclization involved almost specifically Gln‐37 (>95%), with the percentage of Gln‐39 implicated in the cross‐linking being less than 5%. The main derivative was named cyclo‐statherin Q‐37. Guinea pig transglutaminase 2 showed high affinity for statherin in vitro (Km = 0.65 ± 0.06 μM). Cyclo‐statherin was detected in vivo by HPLC‐electrospray ionization ion trap‐mass spectrometry analysis of whole human saliva and it accounted for about 1% of total statherin. Detection of cyclo‐statherin in whole saliva is suggestive of a putative role of this molecule in the formation of the “oral protein pellicle”.
The effects of intense pulsed light (IPL) on blood vessels investigated by mathematical modeling
Authors: Bäumler Wolfgang , Vural Emre , Landthaler Michael , Muzzi Francesco , Shafirstein Gal 
Published: October 2006

AbstractBackground and ObjectivesIntense pulsed light (IPL) sources have been successfully used for coagulation of blood vessels in clinical practice. However, the broadband emission of IPL hampers the clinical evaluation of optimal light parameters. We describe a mathematical model in order to visualize the thermal effects of IPL on skin vessels, which was not available, so far.Study Design/Materials and MethodsOne IPL spectrum was shifted towards the near infrared range (near IR shifted spectrum: NIRSS) and the other was heavily shifted toward the visible range (visible shifted spectrum: VSS). The broadband emission was separated in distinct wavelengths with the respective relative light intensity. For each wavelength, the light and heat diffusion equations were simultaneously solved with the finite element method. The thermal effects of all wavelengths at the given radiant exposure (15 or 30 J/cm2) were added and the temperature in the vessels of varying diameters (60, 150, 300, 500 µm) was calculated for the entire pulse duration of 30 milliseconds.ResultsVSS and NIRSS both provided homogeneous heating in the entire vessel. With the exception of the small vessels (60 µm), which showed only a moderate temperature increase, all vessels exhibited a temperature raise within the vessel sufficient for coagulation with each IPL parameter. The time interval for effective temperature raise in larger vessels (diameter >60 µm) was clearly shorter than the pulse duration. In most instances, the vessel temperature was higher for VSS when compared to NIRSS.ConclusionsWe presented a mathematical model capable of calculating the photon distribution and the thermal effects of the broadband IPL emission within cutaneous blood vessels. Lasers Surg. Med. 39:132–139, 2007. © 2007 Wiley‐Liss, Inc.
Antimicrobial photodynamic therapy combined with conventional endodontic treatment to eliminate root canal biofilm infection
Authors: Garcez Aguinaldo S. , Ribeiro Martha S. , Tegos George P. , Núñez Silvia C. , Jorge Antonio O.C. , Hamblin Michael R. 
Published: October 2006

AbstractBackground and ObjectiveTo compare the effectiveness of antimicrobial photodynamic therapy (PDT), standard endodontic treatment and the combined treatment to eliminate bacterial biofilms present in infected root canals.Study Design/Materials and MethodsTen single‐rooted freshly extracted human teeth were inoculated with stable bioluminescent Gram‐negative bacteria, Proteus mirabilis and Pseudomonas aeruginosa to form 3‐day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify bacterial burdens. PDT employed a conjugate between polyethylenimine and chlorin(e6) as the photosensitizer (PS) and 660‐nm diode laser light delivered into the root canal via a 200‐µ fiber, and this was compared and combined with standard endodontic treatment using mechanical debridement and antiseptic irrigation.ResultsEndodontic therapy alone reduced bacterial bioluminescence by 90% while PDT alone reduced bioluminescence by 95%. The combination reduced bioluminescence by >98%, and importantly the bacterial regrowth observed 24 hours after treatment was much less for the combination (P<0.0005) than for either single treatment.ConclusionsBioluminescence imaging is an efficient way to monitor endodontic therapy. Antimicrobial PDT may have a role to play in optimized endodontic therapy. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Persistent psychosocial problems in children who develop posterior fossa syndrome after medulloblastoma resection
Authors: Wolfe‐Christensen Cortney , Mullins Larry L. , Scott James G. , McNall‐Knapp René Y. 
Published: October 2006

AbstractPurposePosterior fossa syndrome (PFS) occurs in approximately 20% of patients after resection of a tumor from the posterior fossa. Few descriptions of persistent psychosocial consequences exist. We assessed whether the development of PFS is associated with increased risk for emotional, behavioral, and social problems after the cessation of cancer treatment.ProceduresMedical charts and neuropsychological data from 21 children (range = 6–17 years old, median = 9.8) were reviewed. All participants were survivors of childhood medulloblastoma and had been treated with surgical resection of the tumor, craniospinal radiation, +/− chemotherapy, and had comprehensive neuropsychological evaluations 1–2 years post‐treatment. Six of the 21 were diagnosed with PFS. A series of chi‐square tests were conducted to determine whether a relationship existed between PFS and clinically significant levels of emotional, behavioral, and social problems as measured by parent‐report on the Achenbach Child Behavior Checklist (CBCL) and Conners' Parent Rating Scale‐93 (CPRS‐93).ResultsChildren who developed PFS were significantly more likely to exhibit obsessive–compulsive type (i.e., perfectionistic) behaviors, withdrawal behaviors, social problems, and internalizing problems (all P < 0.05) than those who did not develop PFS. Additionally, children with PFS were more likely to evidence anxious–shy behaviors, attention problems, and somatic complaints, although these differences were not statistically significant.ConclusionResults from the current preliminary study suggest that PFS may place children at increased risk for emotional, behavioral, and social problems long after completion of their cancer treatment. Pediatr Blood Cancer 2007;49:723–726. © 2006 Wiley‐Liss, Inc.
New guideline for tramadol usage following adverse drug reactions reported to the Iranian pharmacovigilance center
Authors: Gholami K. , Shalviri G. , Zarbakhsh A. , Daryabari N. , Yousefian S. 
Published: October 2006

AbstractBackgroundTramadol was introduced as injection and oral form to Iranian Pharmaceutical Market in 2002. Shortly after, the injection form of the drug was observed at the top of suspected drug list of Adverse Drug Reactions (ADRs) received monthly by Iranian Pharmacovigilance Center (IPC).Objectives
To detect, assess and report total number of Tramadol‐induced ADRs received by IPC.
To assess the frequency of reported Tramadol‐induced ADRs before and after interventions.
To design a guideline for prevention of probable ADRs due to Tramadol injection.
MethodsA descriptive study was conducted on spontaneous reporting received by IPC from April 2002 to February 2005. All ADRs suspected to be induced by Tramadol registered in the database during mentioned period were analysed. To assess the effect of different interventions based on Spontaneous Reporting System, the trend of reporting frequency of Tramadol‐induced ADRs was evaluated before and after interventions.ResultsThere were 337 cases of Tramadol‐induced ADRs describing 939 reactions, reported to IPC during the study period.Although causal relationship had not been established, three cases of deaths appeared among the reports.The severity of reactions led to implementation of limitations on injectable Tramadol distribution to community pharmacies and the restriction of its use to hospitals only.Since most adverse reactions were dose‐dependent, the drug potency of injectable Tramadol available in the country changed from 100 mg to 50 mg.The assessment of ADR reports received by IPC showed that the frequency of adverse reactions registered in the centre was reduced considerably following these interventions.ConclusionDesigning a detailed programme by Pharmacovigilance Centres and closely monitoring of newly marketed pharmaceutical products is highly recommended. Copyright © 2006 John Wiley & Sons, Ltd.
A single proline substitution is critical for the thermostabilization of Clostridium beijerinckii alcohol dehydrogenase
Authors: Goihberg Edi , Dym Orly , Tel‐Or Shoshana , Levin Inna , Peretz Moshe , Burstein Yigal 
Published: October 2006

AbstractAnalysis of the three‐dimensional structures of three closely related mesophilic, thermophilic, and hyperthermophilic alcohol dehydrogenases (ADHs) from the respective microorganisms Clostridium beijerinckii (CbADH), Entamoeba histolytica (EhADH1), and Thermoanaerobacter brockii (TbADH) suggested that a unique, strategically located proline residue (Pro100) might be crucial for maintaining the thermal stability of EhADH1. To determine whether proline substitution at this position in TbADH and CbADH would affect thermal stability, we used site‐directed mutagenesis to replace the complementary residues in both enzymes with proline. The results showed that replacing Gln100 with proline significantly enhanced the thermal stability of the mesophilic ADH: ΔT = + 8°C (temperature of 50% inactivation after incubation for 60 min), ΔT = +11.5°C (temperature at which 50% of the original CD signal at 218 nm is lost upon heating between 30° and 98°C). A His100 → Pro substitution in the thermophilic TbADH had no effect on its thermostability. An analysis of the three‐dimensional structure of the crystallized thermostable mutant Q100P‐CbADH suggested that the proline residue at position 100 stabilized the enzyme by reinforcing hydrophobic interactions and by reducing the flexibility of a loop at this strategic region. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Routes are trees: The parsing perspective on protein folding
Authors: Hockenmaier Julia , Joshi Aravind K. , Dill Ken A. 
Published: October 2006

AbstractAn important puzzle in structural biology is the question of how proteins are able to fold so quickly into their unique native structures. There is much evidence that protein folding is hierarchic. In that case, folding routes are not linear, but have a tree structure. Trees are commonly used to represent the grammatical structure of natural language sentences, and chart parsing algorithms efficiently search the space of all possible trees for a given input string. Here we show that one such method, the CKY algorithm, can be useful both for providing novel insight into the physical protein folding process, and for computational protein structure prediction. As proof of concept, we apply this algorithm to the HP lattice model of proteins. Our algorithm identifies all direct folding route trees to the native state and allows us to construct a simple model of the folding process. Despite its simplicity, our model provides an account for the fact that folding rates depend only on the topology of the native state but not on sequence composition. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Two alternative substrate paths for compound I formation and reduction in catalase–peroxidase KatG from Burkholderia pseudomallei
Authors: Deemagarn Taweewat , Wiseman Ben , Carpena Xavier , Ivancich Anabella , Fita Ignacio , Loewen Peter C. 
Published: October 2006

AbstractFive residues in the multifunctional catalase–peroxidase KatG of Burkholderia pesudomallei are essential for catalase, but not peroxidase, activity. Asp141 is the only one of these catalase‐specific residues not related with the covalent adduct found in KatGs that when replaced with a nonacidic residue reduces catalase activity to 5% of native levels. Replacing the nearby catalytic residue Arg108 causes a reduction in catalase activity to 35% of native levels, whereas a variant with both Asp141 and Arg108 replaced exhibits near normal catalase activity (82% of native), suggesting a synergism in the roles of the two residues in support of catalase activity in the enzyme. Among the Asp141 variants, D141E is unique in retaining normal catalase activity but with modified kinetics, suggesting more favorable compound I formation and less favorable compound I reduction. The crystal structure of the D141E variant has been determined at 1.8‐Å resolution, revealing that the carboxylate of Glu141 is moved only slightly compared with Asp141, but retains its hydrogen bond interaction with the main chain nitrogen of Ile237. In contrast, the low temperature ferric Electron Paramagnetic Resonance spectra of the D141A, R108A, and R108A/D141A variants are consistent with modifications of the water matrix and/or the relative positioning of the distal residue side chains. Such changes explain the reduction in catalase activity in all but the double variant R108A/D141A. Two pathways of hydrogen bonded solvent lead from the entrance channel into the heme active site, one running between Asp141 and Arg108 and the second between Asp141 and the main chain atoms of residues 237–239. It is proposed that binding of substrate H2O2 to Asp141 and Arg108 controls H2O2 access to the heme active site, thereby modulating the catalase reaction. Proteins 2007. © 2006 Wiley‐Liss, Inc.
A ToxR‐based dominant‐negative system to investigate heterotypic transmembrane domain interactions
Authors: Lindner Eric , Langosch Dieter 
Published: October 2006

AbstractThe ToxR transcription activator system is a genetic tool widely used to examine homotypic interactions of α‐helical transmembrane domains that drive or support oligomerization of integral membrane proteins. Here, we present a variant of this system that was developed to investigate heterotypic interactions. In this system, a homotypically interacting transmembrane domain within the ToxR protein is coexpressed with a potential competitor that is embedded within an inactivated ToxR mutant. Successful heterotypic interaction competes with homotypic interaction in a dominant‐negative fashion as revealed by reduced reporter gene transcription. We expect that this system will be useful for the characterization of transmembrane domains whose homotypic and heterotypic interactions compete with each other. Proteins 2006. © 2006 Wiley‐Liss, Inc.