bluuebunny/crossref_metadata_2025 huggingface dataset:
New Composite Electrode Architecture and Improved Battery Performance from the Smart Use of Polymers and Their Properties
Authors: Guy D. , Lestriez B. , Guyomard D.
Published: March 2004

The smart use of polymers and their properties can be exploited to give new composite electrode architectures (see Figure) and improved battery performance. A new polymeric binder combination with controlled polymer‐filler (carbon black) interactions is described. Composite electrodes based on this binder and Li1.1V3O8 display capacities that are up to twice as high as those obtained for a standard lithium battery electrode.
A Multidye Nanostructured Material for Optical Data Storage and Security Data Encryption
Authors: Pham H. H. , Gourevich I. , Oh J. K. , Jonkman J. E. N. , Kumacheva E.
Published: March 2004

A new class of materials for optical data storage and security data encryption is reported. Multidye colloid particles comprising different dyes in different phases are employed as the building blocks to produce a multicolored multiphase polymeric material. The incorporation of dyes in different phases minimizes energy transfer, provides selective dye photobleaching, and allows storage of different data on a single spot (see Figure and also cover).
Three‐Dimensional Assembly of Polymer Microstructures at Low Temperatures
Authors: Yang Y. , Zeng C. , Lee L. J.
Published: March 2004

A low‐temperature, low‐pressure polymer bonding technique for three‐dimensional assembly of microstructures (see Figure; scale bar 5 μm) based on carbon dioxide (CO2)‐enhanced chain entanglement near the polymer surfaces is presented. The environmentally benign utilization of supercritical CO2 offers scope for the production of polymer‐based biomedical applications and devices.
Reflection and Absorption Techniques for Optical Characterization of Chemically Assembled Nanomaterials
Authors: Roy D. , Fendler J.
Published: March 2004

This review discusses recent developments in the areas of fabrication, certain types of optical characterization, and applications of a selected class of chemically assembled nanomaterials, namely i) gold and silver nanoparticles deposited onto optically transparent glass substrates; ii) thiol‐functionalized self‐assembled monolayers (SAMs); iii) chemically stabilized gold and silver nanoparticles (monolayer protected clusters, MPCs); and iv) MPCs linked to metallic substrates and adsorbates. Six linear optical techniques for the characterization of these materials are discussed: transmission localized surface plasmon resonance spectroscopy, T‐LSPR; propagating surface plasmon resonance spectroscopy, P‐SPR; polarization‐selective Fourier transform infrared reflection absorption spectroscopy, PS‐FTIRRAS; polarization‐modulation Fourier transform infrared reflection absorption spectroscopy, PM‐FTIRRAS; surface‐enhanced infrared reflection absorption spectroscopy, SEIRRAS; and infrared ellipsometry. The review focuses particularly on providing a unified treatment of these six optical techniques by using a relatively simple stratified multilayer model.
Novel Citric Acid‐Based Biodegradable Elastomers for Tissue Engineering
Authors: Yang J. , Webb A. R. , Ameer G. A.
Published: March 2004

The synthesis and characterization of novel biodegradable elastomers, exemplified by poly(1,8‐octanediol‐ co‐citric acid), is reported. Biodegradation, mechanical, and biocompatibility data suggest very good potential for use as porous scaffolds in cardiovascular tissue engineering (see Figure). Material properties can be tailored by modulating the monomer ratio and post‐polymerization conditions.
Investigation of polymorphisms in the CREM gene in panic disorder
Authors: Hamilton Steven P. , Slager Susan L. , Mayo David , Heiman Gary A. , Klein Donald F. , Hodge Susan E. , Fyer Abby J. , Weissman Myrna M. , Knowles James A.
Published: March 2004

Clinical and animal studies suggest a role for pathways regulated by cyclic‐AMP in anxiety. Mouse gene deletion studies, our own linkage findings on chromosome 10, and a recently published genetic association study by Domschke et al. [2003: Am J Med Genet 117B:70–78] suggest that the cAMP responsive element modulator (CREM) may be involved in panic disorder. We have employed a family‐based design to investigate the role of DNA sequence variations in the gene for CREM in panic disorder. We have genotyped 613 individuals in 70 panic disorder pedigrees, as well as 42 parent/offspring triads. Subjects were genotyped at two informative single nucleotide polymorphisms (SNPs) and three polymorphic microsatellites in the CREM genomic region; and the data were analyzed for genetic association and linkage. Linkage analysis employing several diagnostic/genetic models produced a maximum lod score of 0.63 for SNP‐1, located in the 5′ UTR of CREM, under a dominant model with a broad diagnostic definition of panic disorder. Non‐parametric analysis, using the NPL statistic or FBAT, also did not support any linkage or association between the markers and panic disorder. All five markers (spanning 77 kb) used in the study showed modest, but significant linkage disequilibrium. Analysis of 2‐, 3‐, 4‐, or 5‐marker haplotypes using TRANSMIT failed to find any globally significant results; however, individual haplotypes containing a single allele of MS‐3 were nominally associated with panic disorder. These findings provide little additional evidence for a susceptibility locus for panic disorder either within the CREM gene or in a nearby region of chromosome 10p11 in our sample. © 2003 Wiley‐Liss, Inc.
Lack of evidence for an association between WNT2 and RELN polymorphisms and autism
Authors: Li Jun , Nguyen Loan , Gleason Christopher , Lotspeich Linda , Spiker Donna , Risch Neil , Myers Richard M.
Published: March 2004

Autism is a pervasive neurodevelopmental disorder characterized by deficits in language development and social interaction, as well as stereotypical, repetitive behaviors. The etiology of autism is largely unknown. Family and twin studies have provided compelling evidence for a strong genetic component in most idiopathic cases. Several recent candidate gene studies have suggested that alleles of WNT2 and the reelin gene (RELN), two genes involved in distinct aspects of neurodevelopment, confer greater susceptibility to autism. We screened WNT2 for DNA polymorphisms by sequencing all exons and adjacent intronic regions in 24 autistic patients, and identified not only the WNT2 variants reported previously (two common single‐nucleotide polymorphisms (SNPs) in the 5′ upstream region and the 3′ untranslated region (UTR), respectively), but also two new SNPs in its 3′ UTR. We genotyped all four WNT2 polymorphisms and a polymorphic trinucleotide repeat in the 5′ UTR of RELN in 107 families with multiple autistic children, and evaluated evidence for association between these variants and autism by the transmission disequilibrium test (TDT). Our results revealed no deviation from the null hypothesis of no association. Our interpretation of these findings is that it is unlikely that DNA variations in RELN and WNT2 play a significant role in the genetic predisposition to autism. © 2003 Wiley‐Liss, Inc.
Alleles of a reelin CGG repeat do not convey liability to autism in a sample from the CPEA network
Authors: Devlin Bernie , Bennett Pamela , Dawson Geraldine , Figlewicz Denise A. , Grigorenko Elena L. , McMahon William , Minshew Nancy , Pauls David , Smith Moyra , Spence M. Anne , Rodier Patricia M. , Stodgell Chris , Schellenberg Gerard D.
Published: March 2004

A recent study by Persico et al. [2001: Mol Psychiatry 6:150–159] suggests alleles of a CGG polymorphism, just 5′ of the reelin gene (RELN) initiator codon, confer liability for autism, especially alleles bearing 11 or more CGG repeats (long alleles). The association is consistent across both a case‐control and family‐based sample. We attempted to replicate their finding using a larger, independent family‐based sample from the NIH Collaborative Programs of Excellence in Autism (CPEA) Network. In our data, allele transmissions to individuals with autism versus unaffected individuals are unbiased, both when alleles are classified by repeat length and when they are classified into long/short categories. Because of the apparent linkage of autism to chromosome 7q, particularly related to the development of language, we also evaluate the relationship between Reelin alleles and the age at which autism subjects use their first word or first phrase. Neither is significantly associated with Reelin alleles. Our results are not consistent with a major role for Reelin alleles in liability to autism. Published 2004 Wiley‐Liss, Inc.
Genetic, developmental, and physical factors associated with attention deficit hyperactivity disorder in patients with velocardiofacial syndrome
Authors: Gothelf Doron , Presburger Gadi , Levy Darya , Nahmani Ariela , Burg Merav , Berant Michael , Blieden Leonard C. , Finkelstein Yehuda , Frisch Amos , Apter Alan , Weizman Abrahahm
Published: March 2004

Velocardiofacial syndrome (VCFS) is a relatively common developmental neuropsychiatric syndrome caused by a 22q11 microdeletion. There is an extensive variability in the phenotypic expression of this disease. The most common psychiatric disorder in VCFS is attention‐deficit/hyperactivity disorder (ADHD), affecting 35–55% of patients. This study investigated the association of familial, developmental, and physical factors with the occurrence of ADHD in 51 patients with nonfamilial VCFS. Twenty‐one patients (41.2%) were diagnosed with ADHD. There was a significantly greater prevalence of ADHD in the first‐degree relatives of the patients with ADHD than in those without (OR = 5.9, 95% CI = 1.6–22.1, P = 0.006). No differences were noted between the ADHD and non‐ADHD groups in mean Obstetric Complication Scale Score, gestational age, birth weight, age at first words, walking, and achieving bowel control. The two groups also had similar IQ scores (total, verbal, and performance) and had a similar average degree of severity of facial dysmorphism and cardiac and cleft anomalies. These findings indicate that ADHD in VCFS has a genetic contribution and the patients' VCFS‐related developmental factors and physical illnesses play a lesser role. © 2003 Wiley‐Liss, Inc.
Association between the glutathione S‐transferase M1 gene deletion and female methamphetamine abusers
Authors: Koizumi Hiroki , Hashimoto Kenji , Kumakiri Chikara , Shimizu Eiji , Sekine Yoshimoto , Ozaki Norio , Inada Toshiya , Harano Mutsuo , Komiyama Tokutaro , Yamada Mitsuhiko , Sora Ichiro , Ujike Hiroshi , Takei Nori , Iyo Masaomi
Published: March 2004

Several lines of evidence suggest that increased generation of auto‐oxidized dopamine (DA) o‐quinone is associated with the neurotoxicity of methamphetamine (MAP) in the brain, and that, as a cellular defenses against DA‐derived quinines, glutathione S‐transferase (GST) detoxifies auto‐oxidized DA o‐quinone in the brain. Glutathione S‐transferase M1 (GSTM1) of the mu‐class of GSTs catalyzes reaction between glutathione and catecholamine o‐quinones under physiological conditions. This study was undertaken to investigate the role of the GSTM1 gene deletion polymorphism in the neuropathology of MAP abuse. One hundred fifty‐seven MAP abusers and 200 healthy comparison subjects were tested for a genetic polymorphism of GSTM1. The difference in the frequency of deletion (D)/non‐deletion (N) alleles between the female abusers and female controls was close to statistical significance (P = 0.071), although there was no statistical difference (P = 0.651) between male abusers and male controls. Furthermore, the number of female abusers with deletion alleles was significantly (P = 0.007, odds ratio: 2.77, 95% CI 1.30–5.89) higher than that of male abusers with deletion alleles. These findings suggest that GSTM1 gene deletion may contribute to a vulnerability to MAP abuse in female subjects, but not in male subjects. © 2003 Wiley‐Liss, Inc.
Modifier effects in autism at the MAO‐A and DBH loci
Authors: Jones Marshall B. , Palmour Roberta M. , Zwaigenbaum Lonnie , Szatmari Peter
Published: March 2004

Autism is one of a group of pervasive developmental disorders (PDD) characterized by qualitative impairments in reciprocal social communication and by a preference for repetitive, stereotyped activities, interests, and behaviors. The disorder is caused in large part by genetic mechanisms, though no disease genes have yet been identified. The objective of this study was to investigate three markers, two in the DBH gene and one in the MAO‐A gene, for maternal or fetal modifier effects on level of functioning (IQ). At the same time, the possibility of maternal or fetal susceptibility effects was also examined. We assembled 67 affected sibpairs and 45 singletons and determined allele frequencies at the three markers among the affected children and first degree relatives. Sizeable and significant modifier effects were found at the MAO locus and, to a lesser extent, at the DBH locus. Susceptibility effects were also found but not without qualification. We conclude that maternal genotypes at the MAO‐A locus, and possibly at the DBH one, may modify IQ in children with autism through the intrauterine environment. © 2004 Wiley‐Liss, Inc.
Study of heat shrinkability of crosslinked low‐density polyethylene/poly(ethylene vinyl acetate) blends
Authors: Khonakdar Hossein Ali , Morshedian J. , Eslami H. , Shokrollahi F.
Published: March 2004

In this study, the heat‐shrinkage property in polymer was induced by first compounding low‐density polyethylene/poly(ethylene vinyl acetate) (LDPE/EVA) blends with various amounts of peroxide in a twin‐screw extruder at about 130°C. The resulting granules were molded to shape and chemically crosslinked by compression molding. A process of heating–stretching–cooling was then performed on the samples while on a tensile machine. Shrinkability and effective parameters were also investigated using thermal mechanical analysis. The results showed that the gel fraction was higher for the sample of higher EVA content with the same amount of dicumyl peroxide (DCP). A decrease in the melting point and heat of fusion (ΔHf), as determined from DSC, was observed with an increase in the DCP content. Studies on the heat shrinkability of the samples showed that samples stretched above the melting point had a higher shrinkage temperature than those stretched around the crystal transition temperature. The results showed that by increasing the peroxide content, the shrinkage temperature was decreased. These could be attributed to the formation of new spherulites as well as changes in the amount and the size of crystals. Furthermore, in samples elongated at 120°C (above the melting point), the rate of stretching had no effect on the shrinkage temperature. The results showed that the extent of strain had no effect on the temperature of shrinkage, but rather on the ultimate shrinkage value. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1389–1395, 2004
Bone morphogenetic protein expression in newborn rat kidneys after prenatal exposure to radiofrequency radiation
Authors: Pyrpasopoulou Athina , Kotoula Vassiliki , Cheva Angeliki , Hytiroglou Prodromos , Nikolakaki Eleni , Magras Ioannis N. , Xenos Thomas D. , Tsiboukis Theodoros D. , Karkavelas Georgios
Published: March 2004

Effects of nonthermal radiofrequency radiation (RFR) of the global system of mobile communication (GSM) cellular phones have been as yet mostly studied at the molecular level in the context of cellular stress and proliferation, as well as neurotransmitter production and localization. In this study, a simulation model was designed for the exposure of pregnant rats to pulsed GSM‐like RFR (9.4 GHz), based on the different resonant frequencies of man and rat. The power density applied was 5 μW/cm2, in order to avoid thermal electromagnetic effects as much as possible. Pregnant rats were exposed to RFR during days 1–3 postcoitum (p.c.) (embryogenesis, pre‐implantation) and days 4–7 p.c. (early organogenesis, peri‐implantation). Relative expression and localization of bone morphogenetic proteins (BMP) and their receptors (BMPR), members of a molecular family currently considered as major endocrine and autocrine morphogens and known to be involved in renal development, were investigated in newborn kidneys from RFR exposed and sham irradiated (control) rats. Semi‐quantitative duplex RT‐PCR for BMP‐4, ‐7, BMPR‐IA, ‐IB, and ‐II showed increased BMP‐4 and BMPR‐IA, and decreased BMPR‐II relative expression in newborn kidneys. These changes were statistically significant for BMP‐4, BMPR‐IA, and ‐II after exposure on days 1–3 p.c. (P < .001 each), and for BMP‐4 and BMPR‐IA after exposure on days 4–7 p.c. (P < .001 and P = .005, respectively). Immunohistochemistry and in situ hybridization (ISH) showed aberrant expression and localization of these molecules at the histological level. Our findings suggest that GSM‐like RFR interferes with gene expression during early gestation and results in aberrations of BMP expression in the newborn. These molecular changes do not appear to affect renal organogenesis and may reflect a delay in the development of this organ. The differences of relative BMP expression after different time periods of exposure indicate the importance of timing for GSM‐like RFR effects on embryonic development. Bioelectromagnetics 25:216–227, 2004. © 2004 Wiley‐Liss, Inc.
Influence of anesthesia on ocular effects and temperature in rabbit eyes exposed to microwaves
Authors: Kojima Masami , Hata Ikuho , Wake Kanako , Watanabe So‐ichi , Yamanaka Yukio , Kamimura Yoshitsugu , Taki Masao , Sasaki Kazuyuki
Published: March 2004

To investigate the effect of systemic anesthesia on ocular effects and temperature in rabbit eyes exposed to microwaves, one eye each of 43 male pigmented rabbits (Dutch, 1.8–2.2 kg) was exposed at 2.45 GHz for 60–20 min (300 mW/cm2; 108 W/kg), either under anesthesia (ketamine hydrochloride (5 mg/kg) + xylazine (0.23 mg/kg)) or without anesthesia. Changes in the anterior segment were evaluated by image analysis utilizing a Scheimpflug camera, specular microscopy, and a laser flare cell meter. Temperatures within the eye were measured during microwave exposure by a Fluoroptic thermometer. The exposed eyes showed miosis, conjunctival congestion, corneal edema, and an increase in the light scattering of the anterior shallow cortex in the pupillary area of the lens. The group under systemic anesthesia showed much stronger symptoms than those treated without anesthesia. All of the anterior ocular changes disappeared within a week. The highest temperature during exposure was in the vitreous, followed by the anterior chamber, and the retrobulbar cavity of the orbit. The ocular temperatures of the rabbits under systemic anesthesia were 2–9 °C higher than those without anesthesia. Body temperature showed an increase of 1 °C during the exposure. Acute high intensity microwave exposure temporarily induced anterior segments inflammation and lens changes. The more pronounced ocular effects in the anesthetized rabbits were associated with the significantly higher ocular temperatures in the anesthetized animals. The influence of systemic anesthesia on ocular changes should be considered. Bioelectromagnetics 25:228–233, 2004. © 2004 Wiley‐Liss, Inc.
Brownian dynamics of interactions between glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) mutants and F‐actin
Authors: Waingeh Victor F. , Lowe Stephen L. , Thomasson Kathryn A.
Published: March 2004

Brownian dynamics simulations of computer models of GAPDH mutants interacting with F‐actin emphasized the electrostatic nature of such interactions, and confirmed the importance of four previously identified lysine residues on the GAPDH structure (Ouporov, I.V.; Knull, H.R.; Lowe, S.L.; Thomasson, K.A. J Mol Recognit 2001, 14, 29–41) in these interactions. Mutants were GAPDH models in which one or more of the previously identified lysines had been replaced with alanine. Simulations showed reduced binding of these mutants to F‐actin compared to wild‐type GAPDH. Binding was significantly reduced by mutating the four lysines; the specific electrostatic interaction energy of the quadruple mutant was −7.3 ± 1.0 compared to −11.4 ± 0.5 kcal/mol for the wild enzyme. The BD simulations also reaffirmed the importance of quaternary structure for GAPDH binding F‐actin. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Molecular dynamics simulation study of oriented polyamine‐ and Na‐DNA: Sequence specific interactions and effects on DNA structure
Authors: Korolev Nikolay , Lyubartsev Alexander P. , Laaksonen Aatto , Nordenskiöld Lars
Published: March 2004

Molecular dynamics (MD) computer simulations have been carried out on four systems that correspond to an infinite array of parallel ordered B‐DNA, mimicking the state in oriented DNA fibers and also being relevant for crystals of B‐DNA oligonucleotides. The systems were all comprised of a periodical hexagonal cell with three identical DNA decamers, 15 water molecules per nucleotide, and counterions balancing the DNA charges. The sequence of the double helical DNA decamer was d(5′‐ATGCAGTCAG)×d(5′‐TGACTGCATC). The counterions were the two natural polyamines spermidine3+ (Spd3+) and putrescine2+ (Put2+), the synthetic polyamine diaminopropane2+ (DAP2+), and the simple monovalent cation Na+. This work compares the specific structures of the polyamine‐ and Na‐DNA systems and how they are affected by counterion interactions. It also describes sequence‐specific hydration and interaction of the cations with DNA. The local DNA structure is dependent on the nature of the counterion. Even the very similar polyamines, Put2+ and DAP2+, show clear differences in binding to DNA and in effect on hydration and local structure. Generally, the polyamines disorder the hydration of the DNA around their binding sites whereas Na+ being bound to DNA attracts and organizes water in its vicinity. Cation binding at the selected sites in the minor and in the major groove is compared for the different polyamines and Na+. We conclude that the synthetic polyamine (DAP2+) binds specifically to several structural and sequence‐specific motifs on B‐DNA, unlike the natural polyamines, Spd3+ and Put2+. This specificity of DAP2+ compared to the more dynamic behavior of Spd3+ and Put2+ may explain why the latter polyamines are naturally occurring in cells. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Cyclic peptide interleukin 5 antagonists mimic CD turn recognition epitope for receptor α
Authors: Ruchala Piotr , Varadi Gyorgyi , Ishino Tetsuya , Scibek Jeffery , Bhattacharya Madhushree , Urbina Cecilia , Ryk Donald Van , Uings Iain , Chaiken Irwin
Published: March 2004

The cyclic peptide AF17121 (Ac‐VDECWRIIASHTWFCAEE) that inhibits interleukin 5 (IL‐5) function and IL‐5 receptor α‐chain (IL‐5Rα) binding has been derived from recombinant random peptide library screening and follow‐up synthetic variation. To better understand the structural basis of its antagonist activity, AF17121 and a series of analogs of the parent peptide were prepared by solid phase peptide synthesis. Sequence variation was focused on the charged residues Asp2, Glu3, Arg6, Glu17, and Glu18. Two of those residues, Glu3 and Arg6, form an EXXR motif that was found to be common among library‐derived IL‐5 antagonists. The E and R in the EXXR motif have a proximity similar to charged residues in a previously identified receptor α binding region, the β‐strand between the C‐ and D‐helices of human IL‐5. Optical biosensor interaction kinetics and cell proliferation assays were used to evaluate the antagonist activities of the purified synthetic peptides, by measuring competition with the highly active single chain IL‐5. Analogs in which acidic residues (Asp2, Glu3, Glu17, and Glu18) were replaced individually by Ala retained substantial competition activity, with multiple replacements in these residues leading to fractional loss of potency at most. In contrast, R6A analogs had strongly reduced competition activity. The results reveal that the arginine residue is crucial for the IL‐5Rα binding of AF17121, while the acidic residues are not essential though likely complex‐stabilizing particularly in the Asp2–Glu3 region. By CD, AF17121 exhibited mostly disordered structure with evidence for a small β‐sheet content, and replacement of the arginine had no influence on the observed secondary structure of the peptides. The dominance of Arg6 in AF17121 activity corresponds to previous findings of dominance of the positive charge balance in the antiparallel β‐sheet of IL‐5 composed of 88EERRR92 in one strand of the CD turn region of IL‐5 and with Arg32 in the neighboring β‐strand. These results argue that AF17121 and related library‐derived peptides function by mimicking the CD turn receptor α recognition epitope in IL‐5 and open the way to small molecule antagonist design. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Determination of stress‐induced changes in plasma molecular species by two‐dimensional correlation Fourier transform infrared spectrometry
Authors: Petibois Cyril , Desbat Bernard , Déléris Gérard
Published: March 2004

For determining exercise‐induced changes in plasma molecular species, we investigated the feasibility of using two‐dimensional correlation spectra (2D‐COS) on 21 series of plasma samples obtained from progressive exercise tests. Intensities of 2D synchronous and asynchronous correlation peaks were compared to concentration evolutions of glucose, lactate, triglycerides (TG), glycerol, fatty acyl moieties, amino acids, proteins, and albumin [determined from plasma Fourier transform infrared (FTIR) spectra] and to performance and training levels of athletes. Synchronous 2D‐COS allowed us to determine the linear relationship between protein and fatty acid concentration evolutions as exercise intensity increased (ν1 − ν2; 2959 vs 1656 and 1543 cm−1). Asynchronous 2D‐COS allowed differentiation of fibrinolysis level in subjects during intense exercise, as well as parameters of fatty acid metabolism specifically related either to performance or to training levels. Furthermore, unexpected correlated evolutions of molecular species were highlighted by this method, showing that 2D spectrometry may also be used for experimental investigations on human physiology. This study has demonstrated that 2D‐COS may be used for the treatment of complex biological samples, such as plasma. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Study of protein aggregation using two‐dimensional correlation infrared spectroscopy and spectral simulations
Authors: Lefèvre Thierry , Arseneault Karin , Pézolet Michel
Published: March 2004

Two‐dimensional (2D) correlation spectroscopy establishes correlations between intensity variations in a series of spectra obtained by the application of an external perturbation. However, spectral effects (wavenumber shift or bandwidth change) are known to generate apparent asynchronisms in 2D maps. Surprisingly, spectral effects are often neglected in the literature when interpreting experimental maps, which can lead to erroneous conclusions. In an attempt to evaluate the contribution of these effects and that of true asynchronisms on 2D maps, the heat‐induced aggregation of glutamyl‐tRNA synthetase (GluRS) was studied as a typical example of the application of Fourier transform infrared (FTIR) spectroscopy in the amide I region. The data were compared with those obtained from a mutant protein that differs by one amino acid. To determine whether the aggregation mechanisms are identical for both proteins, the experimental 2D maps were compared to simulations based on curve fitting of the initial and final spectra of the series, which allows change in position and bandwidth of the components to be taken into account. Intermediate spectra were generated using a convenient function that mimics the spectral evolution. The speed and the delay of each component were controlled. Apart from the appearance of turns that occur for the mutant and not for GluRS, the aggregation mechanisms of both proteins seems to be essentially identical. In particular, the loss of α‐helices seems to be concomitant with the formation of intermolecular β‐sheets, whereas the loss of intramolecular β‐sheets is delayed. Since the experimental maps are satisfactorily simulated when almost all the components are in phase, it appears that many of the asynchronous features are mainly due to spectral effects. Thus, one has to be aware that true asynchronisms are not necessarily at the origin of peaks observed in asynchronous maps. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Population shift vs induced fit: The case of bovine seminal ribonuclease swapping dimer
Authors: Merlino Antonello , Vitagliano Luigi , Sica Filomena , Zagari Adriana , Mazzarella Lelio
Published: March 2004

Bovine seminal ribonuclease (BS‐RNase) is a unique member of the pancreatic‐like ribonuclease superfamily. This enzyme exists as two conformational isomers with distinctive biological properties. The structure of the major isomer is characterized by the swapping of the N‐terminal segment (M×M BS‐RNase). In this article, the crystal structures of the ligand‐free M×M BS‐RNase and its complex with 2′‐deoxycitidylyl(3′,5′)‐2′‐deoxyadenosine derived from isomorphous crystals have been refined. Interestingly, the comparison between this novel ligand‐free form and the previously published sulfate‐bound structure reveals significant differences. In particular, the ligand‐free M×M BS‐RNase is closer to the structure of M×M BS‐RNase productive complexes than to the sulfate‐bound form. These results reveal that M×M BS‐RNase presents a remarkable flexibility, despite the structural constraints of the interchain disulfide bridges and the swapping of the N‐terminal helices. These findings have important implications to the ligand binding mechanism of M×M BS‐RNase. Indeed, a population shift rather than a substrate‐induced conformational transition may occur in the M×M BS‐RNase ligand binding process. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
An algebraic model of RNA duplex formation
Authors: Bashford J. D. , Jarvis P. D.
Published: March 2004

We propose a simple algebraic description of the two‐body interactions of bases in RNA thermodynamics showing in detail qualitative equivalence with conventional nearest‐neighbor models. The process of obtaining base content, polymer, and oligomer parameters is illustrated, and for duplexes containing Watson–Crick pairs, fits to oligonucleotide duplex heat‐of‐formation data are shown to be statistically equivalent to existing models. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Water‐mediated contacts in thetrp‐repressor operator complex recognition process
Authors: Wibowo Fajar R. , Rauch Christine , Trieb Michael , Wellenzohn Bernd , Liedl Klaus R.
Published: March 2004

Water‐mediated contacts are known as an important recognition tool intrp‐repressor operator systems. One of these contacts involves two conserved base pairs (G6· C−6and A5· T−5) and three amino acids (Lys 72, Ile 79, and Ala 80). To investigate the nature of these contacts, we analyzed the X‐ray structure (PDB code: 1TRO) of thetrp‐repressor operator complex by means of molecular dynamics simulations. This X‐ray structure contains two dimers that exhibit structural differences. From these two different starting structures, two 10 ns molecular dynamics simulations have been performed. Both of our simulations show an increase of water molecules in the major groove at one side of the dimer, while the other side remains unchanged compared to the X‐ray structure. Though the maximum residence time of the concerned water molecules decreases with an increase of solvent at the interface, these water molecules continue to play an important role in mediating DNA–protein contacts. This is shown by new stable amino acids–DNA distances and a long water residence time compared to free DNA simulation. To maintain stability of the new contacts, the preferential water binding site on O6(G6) is extended. This extension agrees with mutation experiment data on A5and G6, which shows different relative affinity due to mutation on these bases [A. Joachimiak, T. E. Haran, P. B. Sigler,EMBOJournal 1994, Vol. 13, No. (2) pp. 367–372]. Due to the rearrangements in the system, the phosphate of the base G6is able to interconvert to the BIIsubstate, which is not observed on the other half side of the complex. The decrease of the number of hydrogen bonds between protein and DNA backbone could be the initial step of the dissociation process of the complex, or in other words an intermediate complex conformation of the association process. Thus, we surmise that these features show the importance of water‐mediated contacts in thetrp‐repressor operator recognition process. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Synthesis, conformation, and immunoreactivity of new carrier molecules based on repeated tuftsin‐like sequence
Authors: Mezö Gábor , Kalászi Adrián , Reményi Judit , Majer Zsuzsa , Hilbert Ágnes , Láng Orsolya , Köhidai László , Barna Krisztina , Gaál Dezsö , Hudecz Ferenc
Published: March 2004

Sequential oligopeptides based on a pentapeptide (TKPKG) derived from tuftsin with different lengths were synthesized by stepwise solid phase methodology. These highly soluble oligomers were nontoxic on mouse spleen cells, and other biological data suggested that tuftsin‐like properties were also presented. The (TKPKG)n (n=2,4,6,8) oligopeptides were not immunogenic; however, they increased sheep red blood cells (SRBC) antigen specific antibody response in mice, demonstrating their immunostimulatory effect. Chemotactic activity was also found on J774 monocyte cells, while MRC5 fibroblasts were chemotactically nonresponders to the tested forms of tuftsin. These oligomers showed unordered and flexible structure by CD measurements, confirmed by computer modeling studies indicating also a fairly good accessibility of the ϵ‐amino group of each lysine residue. Data suggest that these new oligotuftsin derivatives can be considered as promising carriers for synthetic vaccine. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Influence of laparoscopy on postoperative recurrence and survival in patients with ruptured hepatocellular carcinoma undergoing hepatic resection
Authors: Lang B H H , Poon R T P , Fan S T , Wong J
Published: March 2004

Background

Use of laparoscopy in patients with gastrointestinal cancer has been associated with port-site and peritoneal tumour metastases. The effect of laparoscopy on tumour recurrence and long-term survival in patients undergoing resection of ruptured hepatocellular carcinoma (HCC) remains unknown.

Methods

Between June 1994 and December 2001, 59 patients with ruptured HCC underwent surgical exploration with a view to hepatic resection. Laparoscopy with laparoscopic ultrasonography was performed in 33 patients; the other 26 patients underwent exploratory laparotomy without laparoscopy. Perioperative and long-term outcomes were compared between the two groups.

Results

Exploratory laparotomy was avoided in 12 of 13 patients with irresectable HCC who had a laparoscopy. The hospital stay of these 12 patients was significantly shorter than that of eight patients found to have irresectable HCC at exploratory laparotomy (median 11 versus 15 days; P = 0·043). Twenty patients had a laparoscopy followed by open resection of HCC, whereas 18 patients underwent laparotomy and resection without laparoscopy. There were no significant differences in disease-free (16 versus 19 per cent; P = 0·525) and overall (32 versus 48 per cent; P = 0·176) survival at 3 years between the two groups. The tumour recurrence pattern was similar between the two groups, and there were no port-site or wound metastases.

Conclusion

Use of diagnostic laparoscopy in patients with ruptured HCC helps avoid unnecessary exploratory laparotomy. The present data suggest that laparoscopy does not have an adverse effect on tumour recurrence or survival in patients who undergo resection.
Routine use of laparoscopic repair for perforated peptic ulcer
Authors: Siu W T , Chau C H , Law B K B , Tang C N , Ha P Y , Li M K W
Published: March 2004

Background

Laparoscopic repair of perforated peptic ulcer was reported in 1990 but has not gained wide acceptance. The aim of this study was to evaluate the safety and efficacy of laparoscopic repair for perforated peptic ulcer in routine clinical practice.

Methods

This was a prospective analysis of 172 patients who underwent laparoscopic repair of a perforated peptic ulcer between July 1997 and June 2003.

Results

One hundred and seventy-two patients of mean age 54 (range 14–93) years had perforated peptic ulcer diagnosed by laparoscopy. There were 172 duodenal ulcers, 22 prepyloric and 13 non-juxtapyloric gastric ulcers. One hundred and sixty-five patients underwent omental patch closure of perforations; there were six Pólya gastrectomies and one ulcerectomy. Thirty-seven patients (21·5 per cent) required conversion to laparotomy. The mean operating time was 64·8 (range 14–180) min. The median postoperative requirement for intramuscular pethidine was one dose. The median postoperative hospital stay was 6 days. Complications occurred in 28 patients (16·3 per cent) resulting in three reoperations. Six patients with intra-abdominal collections were managed by percutaneous drainage. Two patients who underwent conversion developed a wound infection. Fourteen patients (8·1 per cent) died, 11 of whom were American Society of Anesthesiologists grade III and IV.

Conclusion

Laparoscopic repair of perforated peptic ulcer is a safe emergency procedure in routine clinical practice for patients with perforated pyloroduodenal ulcer.
Epidemiology of venous thromboembolism in a Chinese population
Authors: Cheuk B L Y , Cheung G C Y , Cheng S W K
Published: March 2004

Background

Deep vein thrombosis (DVT) is uncommon in Asians and routine thromboprophylaxis for surgery is controversial. Despite recent reports of higher incidences in some Asian countries, population-based data are lacking.

Methods

Information from 2000 to 2001 was retrieved from a centralized computer public healthcare database serving an ethnic Chinese population of 6·7 million. The incidence, demographics and hospital mortality rates of DVT and pulmonary embolism (PE) were obtained, and analysed for different surgical categories.

Results

The overall annual incidences of DVT and PE were 17·1 and 3·9 per 100 000 population respectively. Venous thromboembolic disease was more common with increasing age in both sexes. The annual age-specific incidences of DVT and PE were 81·1 and 18·6 per 100 000 for those aged 65 years and over. Hospital mortality rates associated with DVT and PE were 7·3 and 23·8 per cent respectively. Among 120 940 surgical operations a year, the mean incidence of postoperative DVT and PE was only 0·13 and 0·04 per cent respectively. No high-risk surgical group was identified.

Conclusion

Venous thromboembolism is not as common in Chinese as in Caucasians, but it is certainly not rare. The majority of DVTs and PEs, however, were not associated with surgery, so routine thromboprophylaxis may not be required.
Long-term outcome following loose-seton technique for external sphincter preservation in complex anal fistula
Authors: Buchanan G N , Owen H A , Torkington J , Lunniss P J , Nicholls R J , Cohen C R G
Published: March 2004

Background

This study determined the long-term outcome after use of the loose-seton technique (LST) to eradicate complex fistula in ano.

Methods

Twenty patients whose complex fistula in ano was treated by the LST a minimum of 10 years previously were assessed by case-note review, supplemented where necessary by mailed and telephone interview.

Results

Eighteen patients had a trans-sphincteric and two a suprasphincteric fistula. There were seven supralevator and 12 ischiorectal secondary extensions. At short-term follow-up, a median of 6 months following seton removal, perianal sepsis had been eradicated in 13 of 20 patients. However, the long-term success rate of the LST was lower than that noted in the short term (four versus 13 of 20). Sixteen patients had persisting or recurrent sepsis, necessitating further surgery in 13. In the long term, external sphincter division was necessary to control sepsis in seven of the 20 patients compared with three of 20 patients at short-term follow-up. The rate of relapse in those with Crohn's disease and cryptoglandular fistula in ano was similar (five of six versus 11 of 14; P = 1·000). The fistula recurred in seven, 11 and 15 patients at 6, 15 and 60 months respectively after seton removal.

Conclusion

The success rate of the LST for complex fistula in ano falls over time. Counselling before seton removal should emphasize that, although most patients do not require sphincter division and some are cured by this technique, many patients develop further sepsis that usually requires surgery.
Randomized clinical trial of the costs of open and laparoscopic surgery for colonic cancer
Authors: Janson M , Björholt I , Carlsson P , Haglind E , Henriksson M , Lindholm E , Anderberg B
Published: March 2004

Background

There has been no randomized clinical trial of the costs of laparoscopic colonic resection (LCR) compared with those of open colonic resection (OCR) in the treatment of colonic cancer.

Methods

A subset of Swedish patients included in the Colon Cancer Open Or Laparoscopic Resection (COLOR) trial was included in a prospective cost analysis; costs were calculated up to 12 weeks after surgery. All relevant costs to society were included. No effects of the procedures, such as quality of life or survival, were taken into account.

Results

Two hundred and ten patients were included in the primary analysis, 98 of whom had LCR and 112 OCR. Total costs to society did not differ significantly between groups (difference in means for LCR versus OCR €1846; P = 0·104). The cost of operation was significantly higher for LCR than for OCR (difference in means €1171; P < 0·001), as was the cost of the first admission (difference in means €1556; P = 0·015) and the total cost to the healthcare system (difference in means €2244; P = 0·018).

Conclusion

Within 12 weeks of surgery for colonic cancer, there was no difference in total costs to society incurred by LCR and OCR. The LCR procedure, however, was more costly to the healthcare system.
Sexual health in women following pelvic surgery for rectal cancer
Authors: Platell C F E , Thompson P J , Makin G B
Published: March 2004

Background

Sexual dysfunction is a recognized complication in men undergoing pelvic surgery for rectal cancer. There is, however, little information on the influence of such surgery on sexual health in women. The aim of this study was to evaluate sexual health in women undergoing pelvic surgery for rectal cancer.

Methods

The study group included women who underwent pelvic surgery for rectal cancer at the Colorectal Surgical Unit, Fremantle Hospital between 1996 and 2002. The patients were contacted by telephone and invited to complete an anonymized questionnaire on sexual health. A control group comprised women who had undergone surgery for colonic cancer during the same interval.

Results

Fifty women in the study group were contacted, of whom 22 completed questionnaires. Sixty-two women in the control group were contacted and 19 completed questionnaires. Women in the study group were significantly younger than those in the control group. Compared with those in the control group, women who had undergone pelvic surgery were significantly more likely to feel less attractive, feel that the vagina was either too short or less elastic during intercourse, experience superficial pain during intercourse, and complain of faecal soiling during intercourse. Women in the study group were concerned that these limitations would persist for the rest of their lives. There were no differences between the two groups in relationship to sexual arousal or libido.

Conclusion

Pelvic surgery for rectal cancer has a significant influence on sexual health in women.
Infection of patients by bloodborne viruses
Authors: Tansley P D T , Beresford N , Ladas G , Goldstraw P , Dusmet M
Published: March 2004

Background

Despite taking precautions, healthcare workers performing invasive procedures run a small risk of infection by bloodborne viruses. When injury occurs, the viral status of the patient is often unknown and testing requires informed consent, which may be refused. On the other hand, although the chance of transmission of infection from a healthcare worker to a patient is extremely small, such personnel have an obligation of disclosure and, if seropositive, are barred from performing invasive procedures.

Methods

The medical literature on bloodborne virus transmission between carers and patients was reviewed, and the UK Department of Health, General Medical Council and Royal College of Surgeons of England guidelines on the risk management of these infections were read, along with secondary references from all sources.

Results and conclusion

Patients have complete protection of confidentiality and the right to refuse testing, but these rights do not apply to the healthcare worker. When injured in circumstances in which the patient cannot or will not permit testing, carers can only submit to the risks of prophylactic treatment or go into denial. Infection may have devastating professional, personal and financial implications to carers and their dependants. Ways to re-establish a just balance between the legitimate rights of patients and healthcare workers are discussed.
Safety lessons taken from the airlines
Authors: Müller M
Published: March 2004

Can we learn from non-medical sources?
The broad ligament: A review of its anatomy and development in different species and hormonal environments
Authors: Miller Anne , Hong Matthew K.‐H. , Hutson John M.
Published: March 2004

The broad ligament is a double fold of peritoneum forming a mesentery for the human female genital tract. We investigated the anatomy of the broad ligament in different species and its hormonal regulation to determine if it had a role in gonadal positioning. The medical and veterinary literature was reviewed for descriptions of broad ligament anatomy and development. In addition, four adult female rats were dissected to compare the macroscopic anatomy of the broad ligament with any homologous structures in the male (n = 2). Detailed review was made of human males with persistent Müllerian duct syndrome (PMDS) and of bovine freemartin calves to determine the effect of abnormal hormonal environments on broad ligament development. Human and veterinary texts show variable broad ligament development between species, most being consistent with the size and shape of the uterus and uterine tubes. The broad ligament in adult female rats is a simple peritoneal fold and is homologous with the mesentery of the testis and vas deferens in males. Patients with PMDS and bovine freemartins have a broad ligament with intermediate anatomy. In PMDS the broad ligament is elongated and narrow, and not attached to the pelvic wall. The broad ligament is the mesentery of the genital ducts, and its anatomy varies with the degree of Müllerian duct fusion. The absence of a human male homologue is unusual, as the genital mesentery persists in male rodents. Apparent lack of a male homologue in the human may relate to obliteration of the processus vaginalis. The variable development of the broad ligament in pathological conditions is consistent with a role for steroid hormones in its development. Clin. Anat. 17:244–251, 2004. © 2004 Wiley‐Liss, Inc.