bluuebunny/crossref_metadata_2025 huggingface dataset:
Cholinergic neuromuscular hyperactivity in patients with myasthenia gravis seropositive for MuSK antibody
Authors: Punga Anna Rostedt , Flink Roland , Askmark Håkan , Stålberg Erik V.
Published: February 2006

A 75‐year‐old man with severe oculobulbar myasthenia gravis (MG) treated with acetylcholine esterase inhibitors (AChEIs) was found to have muscle‐specific tyrosine kinase (MuSK) antibodies. Neurophysiological examination displayed extra repetitive discharges after the compound motor action potential (CMAP) at low‐frequency stimulation, possibly triggered by AChEI. This indicates an abnormal sensitivity to acetylcholine in patients with MuSK antibodies and may be a useful indicator of the adverse effect of AChEI treatment in these patients. Muscle Nerve, 2006
Axonal function and activity‐dependent excitability changes in myotonic dystrophy
Authors: Krishnan Arun V. , Kiernan Matthew C.
Published: February 2006

To investigate peripheral nerve function and its potential contribution to symptoms of weakness in myotonic dystrophy type 1 (MD), nerve excitability was assessed in 12 MD patients. Compound muscle action potentials (CMAPs) were recorded at rest from abductor pollicis brevis (APB) following stimulation of the median nerve. Stimulus–response behavior, threshold electrotonus, a current–threshold relationship, and recovery cycles were successfully recorded in each patient. Compared with controls, there was significant reduction in CMAP amplitude in MD patients. This was accompanied by reduction in depolarizing threshold electrotonus and an increase in refractoriness and in the duration of the relative refractory period. To determine whether alteration in axonal resting membrane potential was a factor underlying these changes, axonal excitability was assessed following maximal contraction of APB for 60 seconds. Following contraction, there was reduction in CMAP amplitude for a submaximal stimulus (by 51.5 ± 11.8%) and an increase in superexcitability (of 22.2 ± 12.0%), consistent with activity‐dependent hyperpolarization, with a greater increase in threshold for MD patients compared to controls (MD group, 22.3 ± 5.1%; controls, 11.7 ± 2.1%; P < 0.04) and prolonged recovery to baseline. The present study has established that greater activity‐dependent changes in excitability may be induced in MD patients by maximal voluntary contraction when compared to controls. The excitability changes and prolonged recovery of threshold following contraction are likely to contribute to symptoms of fatigue and weakness in MD patients. Muscle Nerve, 2006
Lewis–Sumner syndrome in hepatitis C virus infection: A possible pathogenetic association with therapeutic problems
Authors: Caporale Christina M. , Capasso Margherita , Ragno Michele , Muzio Antonio Di , Uncini Antonino
Published: February 2006

A patient with chronic hepatitis from hepatitis C virus (HCV) infection developed Lewis–Sumner syndrome (LSS). The neuropathy worsened after intravenous immunoglobulins, remitted after intravenous methylprednisolone, relapsed during interferon‐α, but responded again to steroids continued for 68 weeks with clinical remission and without worsening of hepatitis. We are not aware of other reports of HCV infection and LSS. This association may be coincidental or related to a virus‐triggered immune‐mediated process. Although the coexistence of a dysimmune neuropathy with hepatitis makes problematic the choice of treatment, we emphasize that the patient's condition during treatment with steroids and the 46 following weeks without therapy has been excellent. Muscle Nerve, 2006
Mortality experiences among 15+ year survivors of childhood and adolescent cancers
Authors: Lawless Shauna C.W. , Verma Puja , Green Daniel M. , Mahoney Martin C.
Published: February 2006

Background

Studies of childhood and adolescent cancer survivorship have tended to focus on limited survival intervals (e.g., 5 and 10 years). Our report evaluates gender‐specific overall mortality, as well as mortality by age group, and by cause, among 15+ year survivors of cancer diagnosed during childhood or adolescence.

Procedure

This was a retrospective cohort study of 565 15+ year childhood cancer survivors from Roswell Park Cancer Institute's Long‐Term Follow‐Up Project. Sex‐ and age‐specific person‐years at risk were accumulated and applied to age‐specific mortality rates for New York State, excluding New York City. Standardized mortality ratios (SMRs), and 95% confidence intervals, were calculated and compared to mortality risks of the general population.

Results

Second malignancy was the leading cause of death among male and female survivors (15/38 deaths, 39%). Excess overall mortality was noted among both males (SMR = 284) and females (SMR = 371). Significant mortality excesses were seen in both genders for deaths due to primary malignant neoplasms and secondary malignancies, as well as cardiac deaths among males. Excess mortality was noted across most age strata. In the scenario of no cancer relapse, overall mortality in both genders did not differ significantly from the general population.

Conclusions

Long‐term survivors of childhood and adolescent cancers continue to demonstrate significant excess mortality. However, overall mortality among 15+ year survivors without a relapse appears to be comparable to the general population. The leading cause of death among 15+ year survivors is second malignancy in this study, which represents a novel and important finding in terms of long‐term follow‐up. Pediatr Blood Cancer 2007;48:333–338. © 2006 Wiley‐Liss, Inc.
Radiotherapy for life‐threatening mediastinal hemangioma with Kasabach–Merritt syndrome
Authors: Kwok‐Williams Michelle , Perez Zuleima , Squire Roly , Glaser Adam , Bew Stephanie , Taylor Roger
Published: February 2006

Kasabach–Merritt Syndrome (KMS) originally referred to a hemangioma associated with life‐threatening thrombocytopenia and a consumption coagulopathy. Treatment includes surgery, steroids, and alpha interferon. However response may be unsatisfactory and mortality rates of 10–37% have been reported. We report a case of a 4‐month‐old male whose disease had not responded to steroids and alpha interferon. He required ventilation, and his condition was deteriorating. It was thought that he would probably die of his condition. He was treated with 9 Gy in three fractions weekly of radiotherapy (RT). Clinical response was good and he is well and free from progression 4 years and 7 months after RT. A review of the literature on the role of RT in the management of hemangiomas is presented. Pediatr Blood Cancer 2007;49:739–744. © 2006 Wiley‐Liss, Inc.
Novel acyclic nitroxides for nitroxide‐mediated polymerization: Kinetic, electron paramagnetic resonance spectroscopic, X‐ray diffraction, and molecular modeling investigations
Authors: Lagrille Olivier , Cameron Neil R. , Lovell Peter A. , Blanchard Robert , Goeta Andrés E. , Koch Rainer
Published: February 2006

This work describes the synthesis of new hydrophobic acyclic nitroxides [derived from 2,2,5‐trimethyl‐4‐phenyl‐3‐azahexane‐3‐nitroxide (TIPNO)] designed to be employed in radical miniemulsion polymerization. We present the synthetic strategies employed to obtain these different nitroxides and the determination of certain important parameters, such as the dissociation rate constant, the combination rate constant, and the decomposition rate constant, of the corresponding alkoxyamines. All these new nitroxides give good control of the bulk radical polymerization of styrene in comparison with the parent TIPNO. The molecular structure of some nitroxides presented herein has been elucidated by single‐crystal X‐ray diffraction, and their structural determination helps us to understand better the influence of the nitroxide structure on the activation energy. A molecular modeling study has also been conducted on these new nitroxides, and a good linear correlation between the activation energy and the CNC bond angle for a series of nitroxides with the same type of leaving radical has been found. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1926–1940, 2006
Atom transfer radical copolymerization of acrylonitrile and ethyl methacrylate at ambient temperature
Authors: Brar A. S. , Saini Tripta
Published: February 2006

Copolymerization of acrylonitrile (AN) and ethyl methacrylate (EMA) using copper‐based atom transfer radical polymerization (ATRP) at ambient temperature (30 °C) using various initiators has been investigated with the aim of achieving control over molecular weight distribution. The effect of variation of concentration of the initiator, ligand, catalyst, and temperature on the molecular weight distribution and kinetics were investigated. No polymerization at ambient temperature was observed with N,N,N′,N′,N″‐pentamethyldiethylenetriamine (PMDETA) ligand. The rate of polymerization exhibited 0.86 order dependence with respect to 2‐bromopropionitrile (BPN) initiator. The first‐order kinetics was observed using BPN as initiator, while curvature in first‐order kinetic plot was obtained for ethyl 2‐bromoisobutyrate (EBiB) and methyl 2‐bromopropionate (MBP), indicating that termination was taking place. Successful polymerization was also achieved with catalyst concentrations of 25 and 10% relative to initiator without loss of control over polymerization. The optimum [bpy]0/[CuBr]0 molar ratio for the copolymerization of AN and EMA through ATRP was found to be 3/1. For three different in‐feed ratios, the variation of copolymer composition (FAN) with conversion indicated toward the synthesis of copolymers having slight changes in composition with conversion. The high chain‐end functionality of the synthesized AN‐EMA copolymers was verified by further chain extension with methyl acrylate and styrene. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1975–1984, 2006
Preparation of linear α‐olefins to high‐molecular weight polyethylenes using cationic α‐diimine nickel(II) complexes containing chloro‐substituted ligands
Authors: Song Chun‐Lei , Tang Li‐Ming , Li Yan‐Guo , li Xiao‐Fang , Chen Jie , Li Yue‐Sheng
Published: February 2006

A series of α‐diimine nickel(II) complexes containing chloro‐substituted ligands, [(Ar)NC(C10H6)CN(Ar)]NiBr2 (4a, Ar = 2,3‐C6H3Cl2; 4b, Ar = 2,4‐C6H3Cl2; 4c, Ar = 2,5‐C6H3Cl2; 4d, Ar = 2,6‐C6H3Cl2; 4e, Ar = 2,4,6‐C6H2Cl3) and [(Ar)NC(C10H6)CN(Ar)]2NiBr2 (5a, Ar = 2,3‐C6H3Cl2; 5b, Ar = 2,4‐C6H3Cl2; 5c, Ar = 2,5‐C6H3Cl2), have been synthesized and investigated as precatalysts for ethylene polymerization. In the presence of modified methylaluminoxane (MMAO) as a cocatalyst, these complexes are highly effective catalysts for the oligomerization or polymerization of ethylene under mild conditions. The catalyst activity and the properties of the products were strongly affected by the aryl‐substituents of the ligands used. Depending on the catalyst structure, it is possible to obtain the products ranging from linear α‐olefins to high‐molecular weight polyethylenes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1964–1974, 2006
Graft polymerization of vinyl monomers inside macroporous polyacrylamide gel, cryogel, in aqueous and aqueous‐organic media initiated by diperiodatocuprate(III) complexes
Authors: Savina Irina N. , Mattiasson Bo , Galaev Igor Yu.
Published: February 2006

Graft polymerization initiated by diperiodatocuprate(III) complex (Cu(III)) initiator was found to be an effective and convenient method for graft polymerization of vinyl monomers onto macroporous polyacrylamide gels, the so‐called cryogels (pAAm‐cryogels). The effect of time, temperature, monomer and initiator concentration during the graft polymerization in aqueous and aqueous‐organic media was studied. The graft polymerization of water‐soluble monomers as [2‐(methacryloyloxy)ethyl]‐trimethylammonium chloride, 2‐hydroxyethyl methacrylate, N‐isopropylacrylamide, and N,N‐dimethylacrylamide proceeds with higher grafting yield in aqueous medium, as compared with that in aqueous‐organic media. Graft polymerization in aqueous‐organic media such as water–DMSO solutions allows grafting of water‐insoluble monomers such as glycidyl methacrylate and N‐tert‐butylacrylamide with high grafting degrees of 100 and 410%, respectively. It was found that the deposition of initiator on the pore surface of cryogels promoted graft polymerization by facilitating the formation of the redox couple Cu(III)‐acrylamide group. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1952–1963, 2006
Synthesis and characterization of block copolymers by metal‐ and solvent‐free ring‐opening polymerization of cyclic carbonates initiated from PEG‐based surfactants
Authors: Morinaga Hisatoyo , Ochiai Bungo , Mori Hideharu , Endo Takeshi
Published: February 2006

Ring‐opening polymerizations of trimethylene carbonate (TC) and 2,2‐dimethyltrimethylene carbonate (DTC) are initiated from hydroxyl‐terminated polyethylene glycol (PEG) and PEG‐based surfactants (Triton X‐100 or Triton X‐405) in the absence of any catalysts. The metal‐ and solvent‐free polymerizations proceed under melt at 150 °C, affording Triton X‐100‐block‐poly(TC) with Mn of 1400–5200 and Triton X‐100‐block‐poly(DTC) with Mn of 1800–7100 in excellent yields. The molecular weights and the comonomer composition of the resulting copolymers are controlled by the feed ratios of the monomers to the initiators, confirmed by gel permeation chromatography and 1H NMR spectroscopy. The solubilities of the block copolymers composed of hydrophilic PEG segment and hydrophobic poly(TC) or poly(DTC) segment depend on both the compositions and the components. For example, Triton X‐100‐block‐poly (TC) (TC/EG = 9.5/9.5) and Triton X‐405‐block‐poly(TC) (TC/EG = 28/40, 46/40) milky suspend in water, while Triton X‐405‐block‐poly(TC) (TC/EG = 9.7/40) dissolves in water. A dynamic light scattering study reveals that the particle distribution of a copolymer, Triton X‐405‐block‐poly(TC) (TC/EG = 9.7/40) in water, has a monodisperse unimodal pattern ranging from 92 to 368 nm. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1985–1996, 2006
Solubilizing single‐walled carbon nanotubes with pyrene‐functionalized block copolymers
Authors: Bahun Greg J. , Wang Clair , Adronov Alex
Published: February 2006

The effect of pyrene distribution within pyrene‐functionalized random and block copolymers on noncovalent polymer/single‐walled carbon nanotube (SWNT) interactions was investigated. The block copolymers served as superior solubilizing agents in comparison with the random copolymers. Also, increasing the pyrene content within a polymer, while a constant molecular weight was maintained, improved SWNT solubility and therefore had to result in stronger polymer–nanotube interactions. However, increasing the length of the pyrene‐containing block diminished nanotube solubility, likely because of a lower number of polymer chains that were capable of binding to the nanotube surface. Atomic force microscopy and transmission electron microscopy indicated that the polymer–SWNT interactions were capable of partially debundling the nanotubes into individual solvated structures. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1941–1951, 2006
The influence of molten fraction on the uniaxial deformation behavior of polypropylene: Real time mechano‐optical and atomic force microscopy observations
Authors: Koike Yutaka , Cakmak Miko
Published: February 2006

In this study, we have coupled the real time mechano‐optical measurements with the off‐line structural characterization techniques including AFM, WAXS, and DSC to establish the quantitative relationships between the “true mechano‐optical behavior and developed morphology” as influenced by the fraction of molten phase present in the polypropylene films. Stretching PP in the solid state invariably leads to formation of fibrillar texture. The evolution of surface morphology in partially molten state was found to depend on the fraction of the molten phase present at the start of the deformation. If the samples are strained past the yielding in partially molten state, the birefringence begins a rapid rise. Concurrent with this, the equatorial zones of the spherulites begin to crack while meridional regions remaining intact. This leads to temporary reduction of crystallinity because of destruction of some of the crystals. If held in this strained state, the crystallite thickening was observed while the birefringence increases while the lost crystallinity is recovered. If the films are strained past the strain hardening point, the microfibrillar structure was found to dominate the surface morphology. When the films are stretched in the melting temperature range, they exhibit substantial nodular surface topology. These nodules that were absent in the solid state deformed samples are hard lamellae buried inside amorphous “soft matter”. The tangential lamellae increasingly become dominant as the processing temperature approaches substantially molten state leading to the observation of a* oriented crystallites in the X‐ray analysis. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 925–941, 2006
High‐density polyethylene layered silicate nanocomposites: Effect of mechanical stretching on the crystal‐to‐crystal transformations, morphology, and extent of exfoliation
Authors: Tzavalas Spiros , Macchiarola Katherine , Gregoriou Vasilis G.
Published: February 2006

High‐density polyethylene/clay nanocomposites were elongated until breakage to investigate the effect of the mechanical stretching on the crystal‐to‐crystal transformations and their morphology. Crystalline transformations of the polymer matrix were studied via Fourier transform infrared spectroscopy, differential scanning calorimetry, and X‐ray diffraction measurements. It was concluded that the stress‐induced crystal‐to‐crystal transformations from orthorhombic structures to monoclinic and pseudohexagonal structures as well as the back‐transformation during relaxation were hindered by the presence of the clay. X‐ray diffraction studies on stretched samples showed that the mechanical stretching led from an intercalated structure to an almost exfoliated structure. These findings agreed with scanning electron micrographs, in which the beneficial effect of stretching on the exfoliation of the clay was evident. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 914–924, 2006
Analysis of a dust explosion caused by several design errors
Authors: Kong Dehong
Published: February 2006

A chemical reaction process began by feeding a combustible fine powder into a reactor through a charging hopper. The reactor and the charging hopper were fitted with a nitrogen inerting system to prevent dust explosions. Surprisingly, a dust explosion occurred when feeding the powder into the reactor from a flexible intermediate bulk container (FIBC).

On‐site investigations found that the design of the inerting system allowed a sufficient amount of air to enter the charging hopper. There were no mechanical, electrical, and thermal sources of ignition inside the closed reactor–charging hopper system before the explosion. Electrostatic discharges appeared to be the ignition source; however, the ignition source could not be identified without further analysis by conducting tests. Therefore, various dust explosion and electrostatic tests were conducted to determine (1) the minimum amount of electrostatic discharge energy required to ignite the dust cloud and (2) the likelihood of various types of electrostatic discharges to ignite the dust cloud under the existing design and process conditions. The test results showed that the powder suspended in air at the optimal dust concentration requires <3 mJ of spark energy to ignite. A glass‐lined pipe at the bottom of the charging hopper was found to be the most likely ignition source. Laboratory tests demonstrated that the ignition was the result of a propagating brush discharge from the glass‐lined pipe. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2006
IR and Raman spectra, density functional computations of vibrational spectrum, molecular geometry, atomic charges, and some molecular properties of 3‐aminobenzonitrile molecule
Authors: Palafox M. A. , Rastogi V. K. , Mittal Lalit , Kiefer W. , Mital H. P.
Published: February 2006

Geometry, vibrational wavenumbers, and several thermodynamic parameters have been calculated using ab initio quantum chemical methods for the 3‐aminobenzonitrile molecule for the first time. The results were compared with experimental values. With the help of specific scaling procedures, the observed vibrational wavenumbers were analyzed and assigned to different normal modes of the molecule. In general, the error obtained was very low. Using potential energy distribution (PED), the contributions of the different modes to each wavenumber were determined. Other general conclusions were also deduced. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Tautomerism and the maximum hardness principle
Authors: Zhang Yi‐Liang , Yang Zhong‐Zhi
Published: February 2006

Through the application of the atom–bond electronegativity equalization method (ABEEM) to the calculation of the hardnesses of more than 300 tautomers, it can be seen that the maximum hardness principle is nearly useless to account for their relative stabilities. Moreover, by calculating the energies of these tautomers with the HF, B3LYP, B3PW91, and MP2 methods at the 6‐31G, 6‐31G*, 6‐31G**, 6‐31+G**, 6‐311G**, or 6‐311++G** level, it is found that all these methods may not be always reliable in predicting their relative stabilities. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Radical‐mediated cytosine and 5‐methylcytosine hydrolytic deamination reactions
Authors: Sun Shujuan , Li Lan , Li Zonghe
Published: February 2006

The mechanisms of cytosine and 5‐methylcytosine hydrolytic deamination reactions in the gas phase have been investigated. The rate‐determining steps of the reactions are found by density functional theory (DFT). The lower barriers of hydrogen and hydroxyl radical‐mediated 5‐methylcytosine deamination make the C‐5 site of 5‐methylcytosine the hot spot for spontaneous mutations. The hydrogen radical inhibits cytosine and 5‐methylcytosine hydrolytic deamination reactions, while the hydroxyl radical clearly leads to an increased risk of genetic mutagenesis. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Hyper‐Wiener vector, Wiener matrix sequence, and Wiener polynomial sequence of a graph
Authors: Guo Xiaofeng , Klein D. J. , Yan Weigen , Yeh Yeong‐Nan
Published: February 2006

The Wiener matrix and the hyper‐Wiener number of a tree (acyclic structure) were first introduced by Randic 1. Randic and Guo and colleagues 2, 3 further introduced the higher Wiener numbers of a tree that can be represented by a Wiener number sequence 1W, 2W, 3W, …, where 1W = W is the Wiener index, and ∑k=1,2, … kW = R is the hyper‐Wiener number. Later the definition of hyper‐Wiener number was extended by Klein et al. for application to any connected structure. In this study, the definition of higher Wiener numbers is extended to be applicable to any connected structure. The concepts of the Wiener vector and hyper‐Wiener vector of a graph are introduced. Moreover, a matrix sequence W(1), W(2), W(3), …, called the Wiener matrix sequence (or distance matrix sequence), and their sum ∑k=1,2, … W(k) = W(H), called the hyper‐Wiener matrix, are introduced, where W(1) = D is the distance matrix, and the sum of the entries of upper triangle of W(k) (resp. W(H)) is just equal to kW (resp. R). A Wiener polynomial sequence and a weighted hyper‐Wiener polynomial of a graph are also introduced. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Clathrin light chain b is capable of affecting potently a major protein phosphatase from microtubules (MT‐PP1)
Authors: Hiraga Akira , Morrice Nick , Honda Eiko , Tamura Shinri , Munakata Hiroshi
Published: February 2006

Clathrin light chain (CL) b purified from bovine brain postmicrotubule supernatant and identified by mass spectrometry potently inhibited a catalytic activity of a major protein phosphatase (PP) that was copurified with microtubules and recognized by antiPP1 antibodies. CLb similarly affected the catalytic subunit and holoenzyme of the PP, little inhibiting the activity of PP2A. Although the CLb from clathrin‐coated vesicles was several hundredfold weaker than our purified CLb, the CLb in the postmicrotubule supernatant, independent of whether it was sedimentable or soluble, was as active as the purified CLb. Thus CLb may be a potent regulator of the PP.
J1 acylase, a glutaryl‐7‐aminocephalosporanic acid acylase from Bacillus laterosporus J1, is a member of the α/β‐hydrolase fold superfamily
Authors: Yau Ming-Hon , Wang Jun , Tsang Paul W.K. , Fong Wing-Ping
Published: February 2006

J1 acylase, a glutaryl‐7‐aminocephalosporanic acid acylase (GCA) isolated from Bacillus laterosporus J1, has been conventionally grouped as the only member of class V GCA, although its amino acid sequence shares less than 10% identity with members of other classes of GCA. Instead, it shows higher sequence similarities with Rhodococcus sp. strain MB1 cocaine esterase (RhCocE) and Acetobacter turbidans α‐amino acid ester hydrolase (AtAEH), members of the α/β‐hydrolase fold superfamily. Homology modeling and secondary structure prediction indicate that the N‐terminal region of J1 acylase has an α/β‐hydrolase folding pattern. The catalytic triads in RhCocE and AtAEH were identified in J1 acylase as S125, D264 and H309. Mutations to alanine at these positions were found to completely inactivate the enzyme. These results suggest that J1 acylase is a member of the α/β‐hydrolase fold superfamily with a serine–histidine–aspartate catalytic triad.
Functional and evolutionary analyses on expressed intronless genes in the mouse genome
Authors: Sakharkar Kishore Ramaji , Sakharkar Meena Kishore , Culiat Cymbeline T. , Chow Vincent T.K. , Pervaiz Shazib
Published: February 2006

Using computational approaches we have identified 2017 expressed intronless genes in the mouse genome. Evolutionary analysis reveals that 56 intronless genes are conserved among the three domains of life – bacteria, archea and eukaryotes. These highly conserved intronless genes were found to be involved in essential housekeeping functions. About 80% of expressed mouse intronless genes have orthologs in eukaryotic genomes only, and thus are specific to eukaryotic organisms. 608 of these genes have intronless human orthologs and 302 of these orthologs have a match in OMIM database. Investigation into these mouse genes will be important in generating mouse models for understanding human diseases.
Characterization of the cysteine protease domain of Semliki Forest virus replicase protein nsP2 by in vitro mutagenesis
Authors: Golubtsov Andrey , Kääriäinen Leevi , Caldentey Javier
Published: February 2006

The function of Semliki Forest Virus nsP2 protease was investigated by site‐directed mutagenesis. Mutations were introduced in its protease domain, Pro39, and the mutated proteins were expressed in Escherichia coli, purified and their activity in vitro was compared to that of the wild type Pro39. Mutations M781T, A662T and G577R, found in temperature‐sensitive virus strains, rendered the enzyme temperature‐sensitive in vitro as well. Five conserved residues were required for the proteolytic activity of Pro39. Changes affecting Cys478, His548, and Trp549 resulted in complete inactivation of the enzyme, whereas the replacements N600D and N605D significantly impaired its activity. The importance of Trp549 for the proteolytic cleavage specificity is discussed and a new structural motif involved in substrate recognition by cysteine proteases is proposed.
In vitro and in vivo studies on CCR10 regulation by Annexin A1
Authors: Rodrigues-Lisoni Flavia Cristina , Mehemet Devinder K. , Peitl Paulo , John Christopher D. , Tajara Eloiza , Buckingham Julia C. , Solito Egle
Published: February 2006

The mode of action of annexin A1 (ANXA1) is poorly understood. By using rapid subtraction hybridization we studied the effects of human recombinant ANXA1 and the N‐terminal ANXA1 peptide on gene expression in a human larynx cell line. Three genes showed strong downregulation after treatment with ANXA1. In contrast, expression of CCR10, a seven transmembrane G‐protein coupled receptor for chemokine CCL27 involved in mucosal immunity, was increased. Moreover the reduction in CCR10 expression induced by ANXA1 gene deletion was rescued by intravenous treatment with low doses of ANXA1. These findings provide new evidence that ANXA1 modulates gene expression.
Hydrogen peroxide is a mediator of indole‐3‐acetic acid/horseradish peroxidase‐induced apoptosis
Authors: Kim Dong-Seok , Jeon Sang-Eun , Jeong Yun-Mi , Kim So-Young , Kwon Sun-Bang , Park Kyoung-Chan
Published: February 2006

Recently, we reported that a combination of indole‐3‐acetic acid (IAA) and horseradish peroxidase (HRP) induces apoptosis in G361 human melanoma cells. However, the apoptotic mechanism involved has been poorly studied. It is known that when IAA is oxidized by HRP, free radicals are produced, and since oxidative stress can induce apoptosis, we investigated whether reactive oxygen species (ROS) are involved in IAA/HRP‐induced apoptosis. Our results show that IAA/HRP‐induced free radical production is inhibited by catalase, but not by superoxide dismutase or sodium formate. Furthermore, catalase was found to prevent IAA/HRP‐induced apoptotic cell death, indicating that IAA/HRP‐produced hydrogen peroxide (H2O2) may be involved in the apoptotic process. Moreover, the antiapoptotic effect of catalase is potentiated by NADPH, which is known to protect catalase. On further investigating the IAA/HRP‐mediated apoptotic pathway, we found that the IAA/HRP reaction leads to caspase‐3 activation and poly(ADP‐ribose) polymerase (PARP) cleavage, which was also blocked by catalase. Additionally, we found that IAA/HRP produces H2O2 and induces peroxiredoxin (Prx) sulfonylation. Consequently, our results suggest that H2O2 plays a major role in IAA/HRP‐induced apoptosis.
Blind docking of drug‐sized compounds to proteins with up to a thousand residues
Authors: Hetényi Csaba , van der Spoel David
Published: February 2006

Blind docking was introduced for the detection of possible binding sites and modes of peptide ligands by scanning the entire surface of protein targets. In the present study, the method is tested on a group of drug‐sized compounds and proteins with up to a thousand amino acid residues. Both proteins from complex structures and ligand‐free proteins were used as targets. Robustness, limitations and future perspectives of the method are discussed. It is concluded that blind docking can be used for unbiased mapping of the binding patterns of drug candidates.
Reconstitution of the enzyme AroA and its glyphosate tolerance by fragment complementation
Authors: Sun Yi-Cheng , Li Yan , Zhang Hai , Yan Hai-Qin , Dowling David N. , Wang Yi-Ping
Published: February 2006

5‐Enolpyruvylshikimate‐3‐phosphate (EPSP) synthase (AroA) is a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants, and is the target of the herbicide glyphosate. Glyphosate tolerance activity of the enzyme could be obtained by natural occurrence or by site‐directed mutagenesis. A functional Pseudomonas putida AroA was obtained by co‐expression of two protein fragments AroA
P. putida
‐N210 and AroA
P. putida
‐C212 in Escherichia coli aroA mutant strain AB2829. From sequence analysis, the equivalent split site on E. coli AroA was chosen for further study. The result indicated that functional E. coli AroA could also be reconstituted from two protein fragments AroA
E. coli
‐N218 and AroA
E. coli
‐C219, under both in vivo and in vitro conditions. This result suggested that the fragment complementation property of this family of enzyme may be general. Additional experiments indicated that the glyphosate tolerance property of AroA could also be reconstituted in parallel with its enzyme activity. The implication of this finding is discussed.
Photochemically enhanced cellular delivery of cell penetrating peptide‐PNA conjugates
Authors: Shiraishi Takehiko , Nielsen Peter E.
Published: February 2006

Recent studies have shown that endosomal release is a major rate‐limiting step for cellular delivery via a variety of cationic cell penetrating peptides. Thus, methods and/or protocols for effective release of endosomally entrapped drugs are highly warranted. Photochemical internalization (PCI) has previously been proposed for this purpose. Here, we demonstrate an enhancement of up to two orders of magnitude of the antisense effects (cytosolic/nuclear) of peptide nucleic acid‐peptide conjugates (Tat, Arg7, KLA) in HeLa cells by a PCI approach using the photosensitizer AlPc2a. These results emphasize the importance of endosomal release for cellular activity of this type of drug delivery and also raise hope that methods like PCI which have applications for in vivo use may also enhance the bioavailability and in vivo efficacy of these types of conjugates.
Geochemistry, mineral chemistry and petrogenesis of a Neoproterozoic dyke swarm in the north Eastern Desert, Egypt
Authors: DAWOUD M. , ELIWA H. A. , TRAVERSA G. , ATTIA M. S. , ITAYA T.
Published: February 2006

Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of the Eastern Desert of Egypt. They are a suite of basaltic andesite and andesite mafic dykes, and dacitic and rhyolitic felsic dykes. The mafic dyke suite is more abundant in the younger granites (577 ± 6 Ma) than in the older granitoids (614 Ma), in which the felsic dykes are the most common. The dyke swarms trend predominantly NE–SW, and the felsic dyke suite is older than the mafic dyke suite. Both dyke suites are calc-alkaline (alkaline dykes are rare) and are relatively poor in TiO2 and Nb but enriched in the incompatible elements and HFSE. The felsic dyke suite is enriched in REE and is strongly LREE fractionated relative to the mafic dyke suite. Although the Hawashiya dykes were emplaced at the end of the Neoproterozoic era in an extensional tectonic setting, they have geochemical characteristics that are consistent with a subduction-related regime. These chemical signatures were inherited from the lithospheric rocks that produced their host Hawashiya granitoids. The felsic dyke suite magma may be derived from crustal rocks (essential source component) by partial melting. The mafic dyke suite magma was generated from a lithospheric mantle and has undergone fractional crystallization of plagioclase, amphibole, clinopyroxene and magnetite, as documented by major and trace elements fractionation modelling.
THE ASSOCIATION BETWEEN SOCIOECONOMIC INDICATORS AND CARDIOVASCULAR DISEASE RISK FACTORS IN RIO DE JANEIRO, BRAZIL
Authors: MARINS VANIA M. R. , ALMEIDA RENAN M. V. R. , PEREIRA ROSANGELA A. , SICHIERI ROSELI
Published: February 2006

The objective of this study was to analyse the association between socioeconomic indicators and cardiovascular disease risk factors in adult residents of Rio de Janeiro city, Brazil. Data were obtained by direct interview and physical examination in a population-based cross-sectional study in the city of Rio de Janeiro, 1995–96. Subjects were selected by two-stage random sampling and information was collected on socioeconomic, anthropometric and demographic characteristics, as well as on existing risk factors for cardiovascular disease. An index to express the risk of cardiovascular disease (CVD) was built, based on the presence of two or more of the following risk factors: overweight (measured by the body mass index, BMI), fat location (measured by the waist–hip ratio index, WHR), smoking, hypertension, sedentary lifestyle and alcohol consumption. The association between this risk index and the socioeconomic variables level of schooling, per capita income and residence location (slum vs non-slum) was evaluated through logistic regression models that controlled for the age of the subjects. Two separate models were built, according to the gender of the subjects. Complete data were collected for 1413 males and 1866 females over the age of 20 years (82% of the intended sample). In the studied population, a considerable prevalence of risk for CVD was found: 42·2% among males and 65·4% among females. For males, the socioeconomic and demographic indicators retained in the logistic model were age (OR 1·01, 95% CI 1·00–1·01), level of schooling (1·77, 95% CI 1·39–2·26) and per capita income (OR 0·77, 95% CI 0·61–0·97). For females, the indicators retained were age (OR 1·02, 95% CI 1·01–1·02) and level of schooling (OR 2·26, 95% CI 1·84–2·77). The findings indicate that cardiovascular disease risk is already an alarming problem in the urban populations of developing countries, and that educational level is the most important socioeconomic factor associated with its presence.
SEXUAL BEHAVIOURS AND CONTRACEPTION AMONG UNIVERSITY STUDENTS IN TURKEY
Authors: ARAS SAHBAL , ORCIN ESMAHAN , OZAN SEMA , SEMIN SEMIH
Published: February 2006

The aim of this study was to evaluate the sexual attitudes and behaviours of university students. An anonymous questionnaire was administered to 550 final-year university students aged 20–25 years in Izmir, Turkey. Male students opposed premarital sexual intercourse for both genders more than female students did. The frequency of sexual intercourse among male students (61·2%) was higher than that among female students (18·3%). The mean age of first sexual intercourse was lower among male than among female respondents. The rate of condom use at first sexual intercourse was 47·4%. The frequency of having two or more past sexual partners and masturbation was higher among males than females. It was found that there were culture-specific and gender-dependent differences in sexual attitudes and behaviours of the university students. These results may help in the planning of education and health policies in Turkey.
Diet of two sympatric carnivores, Cerdocyon thous and Procyon cancrivorus, in a restinga area of Espirito Santo State, Brazil
Authors: Gatti Andressa , Bianchi Rita , Rosa Claudia Regina Xavier , Mendes Sérgio Lucena
Published: February 2006

The crab-eating fox (Cerdocyon thous (Linnaeus, 1766)) and the raccoon (Procyon cancrivorus (Cuvier, 1798)) are medium-sized nocturnal carnivores (3–8 kg) belonging, respectively, to families Canidae and Procyonidae (Berta 1982, Langguth 1975, Yanosky & Mercolli 1993). Both are widely distributed over the Neotropical Region (Colombia, Venezuela, Guyana, Surinam, French Guiana, Paraguay, Uruguay, northern Argentina and the greater part of Brazil) (Berta 1982, Brady 1979, Langguth 1975, Santos & Hartz 1999), being sympatric over most of their range. In Brazil both species are found in various different habitats, including the coastal plains (restingas) (Berta 1987, Langguth 1975, Motta-Junior et al. 1994, Novaes 2002, Santos & Hartz 1999, Wang & Sampaio 2001).
Juvenile tree growth in relation to light availability in second-growth tropical rain forests
Authors: Palomaki Mary Beth , Chazdon Robin L. , Arroyo J. Pablo , Letcher Susan G.
Published: February 2006

Light is a key environmental factor limiting growth and survival of trees in the subcanopy of wet tropical forests (Davies 2001, Thomas 1996). Light availability varies both vertically and horizontally and affects tree height, crown shape and tree architecture (Bongers & Sterck 1998, Sterck & Bongers 2001, Sterck et al. 1999) in addition to growth and survival (Clark & Clark 1992, 2001). Although many studies of tree seedlings and saplings have shown that growth varies significantly with light availability in tropical wet forests (Clark et al. 1993, Iriarte & Chazdon 2005, King 1991, Kohyama 1991, Montgomery & Chazdon 2002, Oberbauer et al. 1988, 1993; Poorter & Werger 1999, Sterck et al. 1999, Welden et al. 1991), few studies have examined these relationships in size classes above 5 cm dbh (Sterck 1999). King et al. (2005) found that annual increment growth of trees in the 8–20-cm dbh size class in two Asian forests was positively dependent on an index of crown light interception, but no direct measurements of light availability were taken in this study. Due to logistical challenges, few direct measurements of light environments above tree crowns have been made in tropical forests (Sterck & Bongers 2001). To our knowledge, no measurements have been made in second-growth forests.
Liana loads and their association with Bertholletia excelsa fruit and nut production, diameter growth and crown attributes
Authors: Kainer Karen A. , Wadt Lúcia H. O. , Gomes-Silva Daisy A. P. , Capanu Marinela
Published: February 2006

We investigated the association between lianas and Bertholletia excelsa (Brazil nut), a long-lived, emergent tree of significant ecological and economic importance in Amazonia. Our objectives were: (1) to determine the relationship between crown liana load and liana number, basal area, and origin in relation to the B. excelsa host; and (2) to determine the relationship between liana load and B. excelsa fruit and nut production, diameter growth, and crown form, position and area. One hundred and forty trees (≥50 cm dbh) were selected with representatives of 10 diameter classes and four liana load categories. To quantify fruit and nut production, fruit counts and nut fresh weights per tree were measured in 2002 and 2003, and annual diameter growth was quantified using dendrometer bands. Trees with lianas produced significantly fewer fruits and had reduced nut fresh weights than liana-free trees. Trees with the most extensive liana loads (>75% crown coverage) were 10.2 times more likely to have crown forms categorized as less than half-crowns or few branches than trees with reduced liana loads. No statistically significant relationship was found between liana load and tree diameter growth. Results suggest that liana cutting might increase B. excelsa fecundity and commercial nut yields.
Comparing composition and diversity of parasitoid wasps and plants in an Amazonian rain-forest mosaic
Authors: Sääksjärvi Ilari E. , Ruokolainen Kalle , Tuomisto Hanna , Haataja Samuli , Fine Paul V. A. , Cárdenas Glenda , Mesones Italo , Vargas Víctor
Published: February 2006

Local species richness and between-site similarity in species composition of parasitoid wasps (Hymenoptera: Ichneumonidae; Pimplinae and Rhyssinae) were correlated with those of four plant groups (pteridophytes, Melastomataceae, Burseraceae and Arecaceae) in a western Amazonian lowland rain forest mosaic. The mosaic structure of the forest was related to variation in soils within the non-inundated terrain. Significant matrix correlation between patterns in parasitoid wasp species composition and plant species composition was found. Most of the overall correlation was due to idiobiont parasitoids of weakly concealed hosts, which attack host larvae and pupae in exposed situations, with two of the four ecologically defined parasitoid groups showing no correlation at all. A positive correlation between the number of plant species and the number of Pimplinae and Rhyssinae species at a site was found when the latter was corrected for collecting effort. Consequently, the degree of floristic difference between sites may be indicative of the difference in species composition of ichneumonids, and the species richness of plants may serve as a predictor of the species richness of parasitoid wasps. Although these results were obtained in a mosaic including structurally and floristically clearly different types of rain forest, the correlation coefficients were relatively low, and the present results lend only weak support to the idea of using plant distributions as indicators of animal distributions.
Allometry, adult stature and regeneration requirement of 65 tree species on Barro Colorado Island, Panama
Authors: Bohlman Stephanie , O'Brien Sean
Published: February 2006

This study provides a community-level analysis of how regeneration requirement and adult stature are related to tree allometry (diameter, height and crown size) throughout post-seedling ontogeny on Barro Colorado Island, Panama. Comparing 65 species, gap species are taller, have higher diameter growth rates and occupy more low-canopy sites (≤10 m canopy height) than shade species at small diameters (≤10 cm dbh). For trees >10 cm dbh, diameter-height relationships and growth rates no longer differ between gap and shade species, but shade species have larger, particularly deeper, crowns than gap species. Species with tall adult stature have more slender stems with larger crowns compared with treelet and mid-canopy species starting at 5 cm dbh. From 10 to 40 cm dbh, diameter growth rate is also significantly greater for tall species. The consistent allometric differences between functional groups on a community level will, in part, determine vertical and horizontal stand structure.
Effects of distribution and structural traits of bird's nest ferns (Asplenium nidus) on oribatid (Acari: Oribatida) communities in a subtropical Japanese forest
Authors: Karasawa Shigenori , Hijii Naoki
Published: February 2006

We studied oribatid (Acari: Oribatida) communities in two distinct microhabitats (litter and root) of the bird's nest fern (Asplenium nidus) in an approximately 4-ha area in a subtropical forest, Okinawa, Japan. We collected a total of 15 729 oribatid mites from 37 ferns and examined whether the size and height of the ferns and the distance between ferns affected the structure of the oribatid communities in terms of the species composition, number of individuals, density (individuals per 100 g dry wt of substrate), number of species and species diversity (Simpson's index). Oribatid communities differed significantly in species composition and density between litter and root components and were evenly distributed horizontally throughout the plot. The density of oribatid mites in the litter decreased significantly with increasing height of the ferns, and the species composition and the numbers of individuals and species in the litter were affected by fern size. Our results suggest that the litter and root of bird's nest ferns allowed diverse oribatid communities to become established, and variations in size and height of the ferns may help to maintain or enhance the diversity of oribatid communities in bird's nest ferns in subtropical forests.
Diversity and ensemble composition of geometrid moths along a successional gradient in the Ecuadorian Andes
Authors: Hilt Nadine , Brehm Gunnar , Fiedler Konrad
Published: February 2006

Little is known about the change of species-rich tropical insect communities along habitat gradients. Diversity and species richness of geometrid moths were investigated at 15 anthropogenically disturbed sites in a montane area in the Andes of southern Ecuador representing a successional gradient. These plots were compared with six closed-forest understorey sites. We collected a total of 23,720 individuals representing 868 morphospecies. Local diversity increased with forest recovery and decreased with increasing distance to the natural forest. 18.6% of all species were found as unique singletons. The mean proportions of local singletons differed significantly between three succession classes. Forest understorey showed a higher proportion of singletons than early and late successional stages. Ordination of the moth samples showed a clear separation of geometrid ensembles at successional sites vs. the forest understorey sites. Patterns of species turnover were influenced by the degree of habitat openness, and to a lesser extent by elevation. However, faunal differences were not related to geographical distances between the sampling sites. In conclusion, geometrid moth ensembles of regenerating Andean montane forest remain diverse, but change significantly in composition relative to adjacent natural forest, whereas the diversity and composition of the geometrid fauna are far more strongly affected in non-forested habitats and abandoned pastures.