bluuebunny/crossref_metadata_2025 huggingface dataset:
Progesterone supplement in pregnancy: an immunologic therapy?
Authors: Ragusa A , de Carolis C , dal Lago A , Miriello D , Ruggiero G , Brucato A , Pisoni M P , Muscarà M , Merati R , Maccario L , Nobili M
Published: August 2004

One of the most interesting functions of the placenta is the regulation of the maternal immune response such that the fetal semi-allograft is tolerated during pregnancy. Trophoblasts are presumed to be essential to this phenomenon because they lie at the maternal-fetal interface, where they are in direct contact with cells of the maternal immune system. Trophoblasts do not express classic major histocompatibility complex (MHC) class II molecules. Surprisingly, cytotrophoblasts express more HLA-G, a MHC class Ib molecule, as they invade the uterus. Progesterone plays an important role in postovulatory regulation of the menstrual cycle. If fertilization occurs, progesterone supports implantation of the ovum and maintains the pregnancy. Progesterone has been named the ‘hormone of pregnancy’, because in preparing the endometrium for embryo implantation and facilitating endometrial development, it is critical to the very survival of a pregnancy. In addition, this key hormone inhibits the rejection of T cell-mediated tissue and also decreases myometrial activity and sensitivity throughout pregnancy. The cellular actions of progesterone are mediated through intracellular progesterone receptors (PRs), which are well studied gene regulators, not express classic major histocompatibility complex. The more used paradigm is relative to the alteration of relationship TH1/TH2, but the complexity of the respective distributions of cytokines at the materno-fetal interface, strongly suggest that, as useful as it certainly was for a while, the Th1/Th2 paradigm must now be considered as an oversimplification. Rather, the existing data point to sequential windows and are suggestive of a system where an extreme complexity is allied to very precise timing and tuning. They also suggest that the materno-fetal relationship is not simply maternal tolerance of a foreign tissue, but a series of intricate mutual cytokine interactions governing selective immune regulation and also control of the adhesion and vascularization processes during this dialogue. However, as shifting the immune response toward the Th2 pattern (IL-4, IL-5, IL-6) may benefit the fetus, whereas development of proinflammatory Th1 cells (secreting IL-2, IFN g, TNF a) may be harmful. Now we are working to open comprise the precise behaviour of NK populations, with the hope of obtaining a diagnostic test of the condition of abortion from ‘immunological causes’.
Feto-maternal immune interaction at the placental level
Authors: Bulla R , Fischetti F , Bossi F , Tedesco F
Published: August 2004

A special interaction is established during pregnancy between the maternal immune system and fetal cells to allow the survival and the normal growth of the fetus. Fetal cells expressing paternal alloantigens are not recognized as foreign by the mother because of an efficient anatomic barrier and a local immunosuppression determined by the interplay of locally produced cytokines, biologically active molecules and hormones. A special balance between TH1 and TH2 lymphocytes has also been observed at the feto-maternal barrier that contribute to control the immune response at this level. An important role is played by trophoblast cells that act as a physical barrier forming a continuous layer and exert immunomodulatory function. Trophoblast cells have also been shown to express regulators of the complement system and to downregulate the expression of HLA antigens. Dysfunction of these cells leads to morphological and functional alterations of the feto-maternal barrier as well as to hormonal and immune imbalance and may contribute to the development of pathologic conditions of pregnancy, such as recurrent spontaneous abortions. Efforts are still needed to better understand the physiology of the feto-maternal interaction and the pathogenetic mechanisms responsible for tissue damage in pathologic conditions of pregrancy.
IVIG in APS pregnancy
Authors: Triolo G , Ferrante A , Accardo-Palumbo A , Ciccia F , Cadelo M , Castelli A , Perino A , Licata G
Published: August 2004

For more than two decades, the intravenous administration of high doses of IgG pooled from the plasma of healthy donors (immune globulin therapy, also known as ‘IVIG’) has benefited patients with a variety of autoimmune disorders. A potential therapeutic role of IVIG in the prevention of thrombosis and of miscarriages in antiphospholipid syndrome (APS) has been postulated. Multicenter randomized controlled trials attempted to define the role of IVIG in preventing pregnancy complications in APS indicate that simple anticoagulation could not be completely satisfactory, and certain patient subgroups might take advantage of IVIG therapy alone or in combination with heparin.
Anaesthesiological aspects of pregnancy in patients with rheumatic diseases
Authors: Wetzl R G
Published: August 2004

The anaesthesiologist facing a pregnant woman with rheumatic disease is caught between a rock (the problems of general anaesthesia, i.e., the difficult airway and/or the cardiopulmonary dysfunctions that can worsen the response to general anaesthetics or to mechanical ventilation) and a hard place (the problems of loco-regional anaesthesia, i.e., intrinsic or iatrogenic haemostatic dysfunctions, potentially causing spinal haematoma, the most threatening complication). However, the term lupus anticoagulant is a misnomer and in the absence of an underlying coagulation deficit or anticoagulant therapy, the anaesthesiologist can usually guarantee epidural analgesia for vaginal delivery to parturients affected by rheumatic diseases (so contributing to the decrease of the caesarean section rate) and, in case of a caesarean section for medical or obstetrical indications, often he can perform a loco-regional anaesthesia, which determines a substantially lower maternal mortality rate. It is very important to adopt a multidisciplinary approach comprising an antepartum team evaluation (to be performed at 36th gestational week) of the basal condition of the parturient: together, the obstetrician, the rheumatologist and the anaesthesiologist should define the type of delivery. We will also try to define the haemostatic safety criteria to be fulfilled for administration of an epidural analgesia to a parturient affected by rheumatic disease.
Neonatal outcome in patients with rheumatic disease
Authors: Motta M , Tincani A , Lojacono A , Faden D , Gorla R , Airò P , Neri F , Gasparoni A , Ciardelli L , de Silvestri A , Marconi M , Chirico G
Published: August 2004

Rheumatic autoimmune diseases have a higher prevalence in women, particularly during their childbearing age. Due to improved management, an increasing number of patients plan and carry out one or more pregnancies. Therefore, a growing interest is being paid to the possible consequences of maternal disease and associated treatment on the fetus and newborn infant. If maternal disease is characterized by the presence of IgG isotype autoantibodies, these can cross the placenta with possible antibody-mediated damage to the fetus. This is typically the case of the so called neonatal lupus erythematosus (NLE); a similar mechanism has been shown in infants of patients with immune thrombocytopenic purpura (ITP) and, less frequently, in those from mothers with antiphospholipid syndrome (APS). Indeed, this last condition is often responsible for placental, rather than neonatal, pathology. In addition, immunosuppressive and other drugs administered to the mothers during pregnancy and lactation might affect the fetal and neonatal immune system development. Finally, mothers disease and/or treatment could be related to neuropsychological alteration reported in some of their children.
Paraoxonase and Superoxide Dismutase Gene Polymorphisms and Noise-Induced Hearing Loss
Authors: Fortunato Giuliana , Marciano Elio , Zarrilli Federica , Mazzaccara Cristina , Intrieri Mariano , Calcagno Giuseppe , Vitale Dino F , La Manna Paolo , Saulino Claudio , Marcelli Vincenzo , Sacchetti Lucia
Published: September 2004

Background: Noise-induced cochlear epithelium damage can cause hearing loss in industrial workers. In experimental systems, noise induces the release of free radicals and may damage the cochlear sensorial epithelium. Therefore, genes involved in regulating the reactive oxygen species manganese-superoxide dismutase (SOD2) and the antioxidant paraoxonase (PON) could influence cochlea vulnerability to noise. We evaluated whether susceptibility to noise-induced hearing loss (NIHL) is associated with SOD2, PON1, and PON2 polymorphisms in workers exposed to prolonged loud noise.

Methods: We enrolled 94 male workers from an aircraft factory in the study. The SOD2 gene was screened by denaturing reversed-phase HPLC, and the PON1 (Q192R and M55L) and PON2 (S311C) polymorphisms were analyzed by PCR amplification followed by digestion with restriction endonucleases.

Results: Three known (A16V, IVS3-23T/G, and IVS3-60T/G) and two new SOD2 polymorphisms (IVS1+ 8A/G and IVS3+107T/A) were identified. Regression analysis showed that PON2 (SC+CC) [odds ratio (OR) = 5.01; 95% confidence interval (CI), 1.11–22.54], SOD2 IVS3-23T/G and IVS3-60T/G (OR = 5.09; 95% CI, 1.27–20.47), age (OR = 1.22; 95% CI, 1.09–1.36), and smoking (OR = 49.49; 95% CI, 5.09–480.66) were associated with NIHL. No association was detected for PON1 (QQ+RR) and PON1 (LL) genotypes.

Conclusions: Our data suggest that SOD2 and PON2 polymorphisms, by exerting variable local tissue antioxidant roles, could predispose to NIHL. However, caution should be exercised in interpreting these data given the small sample size and the difficulty in matching cases to controls regarding the overwhelming risk factor, i.e., smoking at least 10 cigarettes/day.
Fifty years of non‐Newtonian fluid dynamics
Authors: Denn Morton M.
Published: August 2004

Non‐Newtonian fluid dynamics, which was developed during the second half of the twentieth century, has become a part of the core research and teaching portfolio of chemical engineers. This overview reflects on classes of flows in which inherent nonlinearity causes non‐Newtonian fluids to exhibit qualitatively different behavior from Newtonian fluids. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2335–2345, 2004
Saccade velocity is controlled by polyglutamine size in spinocerebellar ataxia 2
Authors: Velázquez‐Pérez Luis , Seifried Carola , Santos‐Falcón Nieves , Abele Michael , Ziemann Ulf , Almaguer Luis Enrique , Martínez‐Góngora Edilberto , Sánchez‐Cruz Gilberto , Canales Nalia , Pérez‐González Ruth , Velázquez‐Manresa Mercedes , Viebahn Bettina , Von Stuckrad‐Barre Sebastian , Fetter Michael , Klockgether Thomas , Auburger Georg
Published: August 2004

We assessed maximal saccade velocity (MSV) in 82 spinocerebellar ataxia type 2 (SCA2) patients and 80 controls, correlating it to disease duration, polyglutamine expansion size, age at onset, ataxia score, age, and sex. Little overlap with normal values was found even at earliest stages. Stepwise linear regression analysis showed that 60‐degree MSV was strongly influenced by polyglutamine size and less by disease duration, whereas the reverse was found for ataxia score. Saccade velocity thus is a sensitive, quite specific, and objective endophenotype, useful to search polyglutamine modifier genes. Ann Neurol 2004;56:444–447
Kinetics of copolymerization of acrylonitrile with ammonium itaconate in a H2O/dimethyl formamide mixture
Authors: Chen Hou , Liang Ying , Wang Cheng‐Guo
Published: August 2004

Kinetics of copolymerization of acrylonitrile (AN) with ammonium itaconate (AI) initiated by azobisisobutyronitrile (AIBN) were investigated in a H2O/dimethyl formamide (DMF) mixture between 50 and 70°C under a N2 atmosphere. The rate of copolymerization and particle size were measured. The kinetic equation of copolymerization system is obtained and the overall activation energy for the copolymerization system was computed. Values of monomer apparent reactivity ratios were calculated by the Kelen–Tudos method. It was found that in DMF‐rich reaction medium (DMF/H2O > 80/20), monomer apparent reactivity ratios are similar to those in the solution polymerization system. Effect of hydroquinone and dioxane additives on copolymerization was discussed. The polymerization is retarded by hydroquinone and accelerated by dioxane, which confirms the free‐radical copolymerization of AN with AI. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1151–1155, 2004
Synthesis of montmorillonite/polystyrene nanocomposites in supercritical carbon dioxide
Authors: Dong Zexuan , Liu Zhimin , Zhang Jianling , Han Buxing , Sun Donghai , Wang Yong , Huang Ying
Published: August 2004

Monomer styrene and initiator N,N′‐azobis(isobutyronitrile) were impregnated into montmorillonite (MMT) galleries using supercritical CO2 at 35°C and 12.0 MPa, after thermal polymerization of monomer at 65°C, resulting in MMT/polystyrene nanocomposites. The morphology and structure of the products were characterized by FTIR, powder X‐ray diffraction, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The results indicate that MMT is dispersed in the composite with intercalated and exfoliated structures, enhancing the thermal stability of nanocomposites. Changing the soaking time and the content of MMT in the supercritical solution during the impregnating process can control the exfoliated extent of MMT. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1194–1197, 2004
Crosslinking polymerization leading to interpenetrating polymer network formation. 3. Polyaddition crosslinking reaction of poly(methyl methacrylate‐co‐2‐methacryloyloxyethyl isocyanate) with poly(oxytetramethylene) glycol in the presence of linear polymethacrylate resulting in semi‐interpenetrating polymer network
Authors: Kiguchi Tadahiro , Aota Hiroyuki , Matsumoto Akira
Published: August 2004

As part of a series of our works concerned with the elucidation of the crosslinking polymerization mechanism leading to the interpenetrating polymer network (IPN) formation, in which IPN consists of both polyurethane (PU) and polymethacrylate (PM) networks, this article deals with the polyaddition crosslinking reactions of poly(methyl methacrylate‐co‐2‐methacryloyloxyethyl isocyanate) poly(MMA‐co‐MOI) [MMA/MOI = 99/1] as a novel multifunctional polyisocyanate with poly(oxytetramethylene) glycol [H‐(OCH2CH2CH2CH2)n‐OH (n = 28)] (POTMG‐28) in the presence of two types of linear PMs, differently miscible with the resulting PU networks, leading to semi‐IPN formation. Thus, poly(MMA‐co‐MOI) was prepared by the radical copolymerization of MOI with MMA in the presence of CBr4 as a chain‐transfer agent. No influence of the linear PM on the rate of polyaddition crosslinking reaction was observed. The actual gel points were compared with the theoretical ones calculated according to Macosko's equation: the deviation of the actual gel point from the theoretical one was rather small, close to the ideality, and the delayed gelation from theory tended to become a little smaller in the presence of PM. These are discussed mechanistically to deepen the understanding of the PU network formation in the presence of a linear PM resulting in semi‐IPN, along with the data of the intrinsic viscosities of resulting prepolymers. To collect a direct evidence of semi‐IPN formation, we attempted to pursue the incorporation of the linear PM into the resulting PU networks by 1H‐NMR and UV‐vis spectroscopy; in the latter case, the copolymers containing a small amount of pyrenyl methacrylate were used as linear PMs because the pyrenyl group was employed as the probe for UV‐vis spectroscopic determination of the amount of the incorporated PM. The swelling ratio of the gel became lower in the presence of a linear PM. All data for the polyaddition crosslinking reactions of poly(MMA‐co‐MOI) with POTMG‐28 in the presence of PM, along with the mechanistic discussion, demonstrate that the freely compatible molecular interaction would lead to a true semi‐IPN formation as a result of the good miscibility between PU networks and a linear PM. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1198–1208, 2004
Crystallization, melting, and rheology of reactive polyamide blends
Authors: Lake Wendell B. , Kalakkunnath Sumod , Kalika Douglass S.
Published: August 2004

The crystallization and melting characteristics of a series of polyamide blends based on PA 4,6 and PA 6I were investigated by calorimetric methods; preparation of the samples was conducted so as to control the extent of transamidation occurring in the melt before crystallization. Blend samples with minimal prior thermal history displayed a modest degree of melting point depression compared to the equilibrium melting temperature of PA 4,6 (T = 309.5°C). Application of the Nishi–Wang equation indicated a value of χ = −0.25 for the blends. PA 4,6 and the blends followed Avrami crystallization kinetics with exponents in the range 2.0 to 2.5; no systematic variation of n with blend composition was observed. The influence of transamidation was investigated for samples exposed to varying melt temperatures and melt times with the extent of transreaction quantified using 13C‐NMR. Increasing extents of transreaction led to a decrease in both the rate of crystallization and the overall bulk crystallinity of the blends owing to a reduction in the length and number of crystallizable blocks present along the polymer chains. Capillary rheometry studies indicated a strong sensitivity to time in the melt for the PA 4,6 homopolymer, and the mechanism responsible for the observed decrease in apparent viscosity was also operative in the blend samples. As such, it was not possible to independently assess the influence of transreaction on the rheology of the blends. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1245–1252, 2004
Surface degradation and hydrophobic recovery of polyolefins treated by air corona and nitrogen atmospheric pressure glow discharge
Authors: Guimond Sébastien , Wertheimer Michael R.
Published: August 2004

The surface degradation and production of low molecular weight oxidized materials (LMWOM) on biaxially oriented polypropylene (BOPP) and low‐density polyethylene (LDPE) films was investigated and compared for two different dielectric barrier discharge (DBD) treatment types, namely air corona and nitrogen atmospheric pressure glow discharge (N2 APGD). Contact angle measurements, X‐ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) analyses were performed in conjunction with rinsing the treated films in water. It is shown that N2 APGD treatments of both polyolefins result in much less surface degradation, therefore, allowing for a significantly higher degree of functionalization and better wettability. Hydrophobic recovery of the treated films has also been studied by monitoring their surface energy (γs) over a period of time extending up to several months after treatment. Following both surface modification techniques, the treated polyolefin films were both found to undergo hydrophobic recovery; however, for N2 APGD modified surfaces, γs ceases to decrease after a few days and attains a higher stable value than in the case of air corona treated films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1291–1303, 2004
Synthesis and Antinociceptive Activity of (5‐Chloro‐2(3H)‐benzothiazolon‐3‐yl)propanamide Derivatives
Authors: Önkol Tijen , Yildirim Engin , Erol Kevser , Ito Shigero , Şahin M. Fethi
Published: August 2004

Ten new (5‐chloro‐2(3H)‐benzothiazolon‐3‐yl)propanamide derivatives have been synthesized. The compounds were tested for antinociceptive activity by tail clip, tail flick, hot plate and writhing test by using aspirin and dipyrone as standards. Among these compounds, 1‐[3‐(5‐chloro‐2(3H)‐benzothiazolon‐3‐yl)‐propanoyl]‐4‐(4‐chlorophenyl)piperazine (11e) has been found to be significantly more active than the other compounds synthesized as well as the standards in all tests.
Effects of small neutral osmolytes on the supercoiling free energy and intrinsic twist of p30δ DNA
Authors: Rangel David P. , Sucato Christopher A. , Spink Charles H. , Fujimoto Bryant S. , Schurr J. Michael
Published: August 2004

Both theory and experiments are employed to investigate the effects of small neutral osmolytes on the average intrinsic twist (l0), the torsion and bending elastic constants, and the twist energy parameter (ET) that governs the supercoiling free energy. The experimental data for ethylene glycol and acetamide at 37°C suggest, and are interpreted in terms of, a model wherein the DNA exhibits an equilibrium between two distinct conformational states that possess different numbers of bound water molecules and exhibit different intrinsic twists and torsion and bending elastic constants. Expressions are derived to relate the effective ET and l0 to the equilibrium constant, water activity (aw), and number (n) of bound water molecules released per cooperative domain undergoing the two‐state transition. The variations of l0 and ET with −ln(aw) are similar for acetamide and ethylene glycol at 37°C. Fitting the theory to those data yields the range n = 103–125 for ethylene glycol and n = 71–113 for acetamide, depending on the assumed value of ET for the dehydrated state. The cooperative domain size of the two‐state transition is estimated to exceed about 25–30 base pairs (bp). Between 0 and 19.4 w/v % ethylene glycol, the torsion elastic constant, measured by time‐resolved fluorescence polarization anisotropy (FPA), increases by 1.37‐fold, whereas the measured ET decreases by 1.15‐fold over that same range. The implied decrease in bending rigidity over that range is by a factor of about 0.7. The variations of l0 and ET with increasing −ln(aw) due to added ethylene glycol at 37°C are far smaller than the corresponding variations observed previously at 14 and 15°C. However, at 21°C, upon adding either ethylene glycol or acetamide, l0 and ET initially decline steeply with increasing −ln(aw), with slopes possibly comparable to those seen at 14 and 15°C, but then flatten out and follow curves similar to those at 37°C. Possible origins of such mixed behavior are discussed. The effects of betaine at both 37 and 21°C differ qualitatively and quantitatively in various respects from those of ethylene glycol and acetamide. Upon adding sucrose, l0 initially jumps to higher plateaus at both 37 and 21°C, but its effects on ET cannot be reliably assessed, due to the limited range of −ln(aw). © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
TrkAexpression in peripheral neuroblastic tumors
Authors: Shimada Hiroyuki , Nakagawa Atsuko , Peters Julius , Wang Hong , Wakamatsu Peter K. , Lukens John N. , Matthay Katherine K. , Siegel Stuart E. , Seeger Robert C.
Published: August 2004

BACKGROUND

This study was conducted to investigate the prognostic significance and biologic relevance oftrkAexpression levels in peripheral neuroblastic tumors (pNTs) (i.e., neuroblastoma, ganglioneuroblastoma, and ganglioneuroma).

METHODS

Levels oftrkAexpression from a total of 265 pNTs were determined by quantitative polymerase chain reaction analysis with Genescan software. The results were analyzed according to histopathology (favorable histology [FH] vs. unfavorable histology [UH] according to the International Neuroblastoma Pathology Classification) andMYCNtumor status (amplified vs. nonamplified) along with clinical stage and outcomes of the patients.

RESULTS

The levels oftrkAexpression differed significantly between the group of patients who werealive and well(n= 170 patients) and the group that hadprogressed or died(n= 95 patients) and between the group that wasalive(n= 188 patients) and the group thatdied(n= 77 patients). However, thetrkAexpression levels were not independent predictors of clinical outcome when the proportional hazards model contained the known prognostic variables of clinical stage, histopathology, andMYCNstatus (all tests were done in 196 patients). In the neuroblastoma category (n= 173 tumors), tumors in the FH/nonamplifiedMYCNsubset (n= 112 tumors) expressed higher levels oftrkAand showed an age‐dependent neuroblastic differentiation: They were classified into either a poorly differentiated subtype (n= 91 tumors; all patients age < 1.5 years at diagnosis) or a differentiating subtype (n= 21 tumors; 57% of patients ages 1.5–5.0 years). Tumors in the UH/amplifiedMYCNsubset (n= 30 tumors) expressed significantly lower levels oftrkAand showed very limited neuroblastic differentiation. Tumors in the FH/amplifiedMYCNsubset were very rare (n= 3 tumors) and expressed higher levels oftrkA. Tumors in the UH/nonamplifiedMYCNsubset (n= 28 tumors) hadtrkAlevels in a wide range and showed limited neuroblastic differentiation.

CONCLUSIONS

For patients with pNTs, levels oftrkAexpression did not add significant information to prognostic grouping, as defined by the combination of clinical stage, histopathology, andMYCNstatus. There was a biologically relevant correlation between molecular properties (trkAexpression andMYCNstatus) and histopathologic features of the tumors in the neuroblastoma category. Cancer 2004. © 2004 American Cancer Society.
Expression of Hsp27 in retinal ganglion cells of the rat during postnatal development
Authors: Hawkes Erin L. , Krueger‐Naug Anne Marie R. , Nickerson Philip E.B. , Myers Tanya L. , Currie R. William , Clarke David B.
Published: August 2004

The small heat shock protein Hsp27 has been shown to protect neurons from apoptosis. We have recently shown the expression of Hsp27 in a subset of injured adult retinal ganglion cells (RGCs), a response that is muted by the administration of brain‐derived neurotrophic factor. This work has suggested a role for Hsp27 in the long‐term survival of RGCs following injury. The purpose of this study was to investigate the expression of Hsp27 during postnatal retinal development, based on Hsp27's role as a neuronal survival factor and on its up‐regulation in the adult injured retina. Expression of Hsp27 in the developing retina was examined at various times postnatally (between P0 and P24) by using immunohistochemical techniques. We report that Hsp27 expression peaks in the ganglion cell layer between P6 and P12 and is not detected at earlier (P0–P3) or later (P15–P24) times. Double labeling of the Hsp27‐positive cells with Fluorogold applied to the superior colliculus confirmed that Hsp27‐positive cells in the ganglion cell layer are RGCs. We have shown developmentally regulated expression of Hsp27 in RGCs of the postnatal rat. The retinal expression of Hsp27 correlates temporally with innervation of the tectum by late‐born RGCs and with onset of spontaneous retinotectal activity. We propose that the expression of Hsp27 may play an important role in retinal development during a critical period of RGC functional connectivity with the superior colliculus. J. Comp. Neurol. 478:143–148, 2004. © 2004 Wiley‐Liss, Inc.
Projection patterns of posterior dorsal unpaired median neurons of the locust subesophageal ganglion
Authors: Bräunig Peter , Burrows Malcolm
Published: August 2004

Six neurons in a group of dorsal unpaired median (DUM) neurons with cell bodies in the posterior part—maxillary and labial neuromeres—of the subesophageal ganglion of locusts have two axons each that descend into both the left and the right halves of the ganglia of the ventral nerve cord. None of the neurons has peripheral axons, so they are interneurons. Electrophysiology shows that the axons of at least four neurons project to the terminal abdominal ganglion to which they conduct spikes at a velocity of 0.5–0.6 m · second–1. In the somata, the spikes have a smaller amplitude and briefer duration at half height than the spikes of thoracic, efferent DUM neurons. Each neuron has bilaterally symmetrical branches within the subesophageal ganglion and in the thoracic ganglia. On the basis of the specific patterns of branches, and the neuropiles, tracts, and commissures in which they occur, three types of neurons (DUM SD 1–3) can be recognized. DUM SD 1 and 3 project to ventral regions of neuropile in the thoracic ganglia in which the efferent DUM neurons of these ganglia have no branches. DUM SD 2 projects to dorsal neuropiles. The projection patterns of these putatively octopaminergic neurons suggest that they could be the source of the octopaminergic modulation of networks underlying sensory processing and motor pattern generation within these ganglia. Within this group of posterior DUM neurons, two additional cells were stained that have axons ascending to the brain. J. Comp. Neurol. 478:164–175, 2004. © 2004 Wiley‐Liss, Inc.
Ten Years of Plasma Crystals ‐ from ICPIG (Bochum) to ICPIG (Greifswald)
Authors: Morfill G. E. , Ivlev A. V. , Khrapak S. A. , Klumov B. A. , Rubin‐Zuzic M. , Konopka U. , Thomas H. M.
Published: August 2004

The current status of experimental and theoretical research into plasma crystals is reviewed. We start with the derivation of a generalized phase diagram for complex plasmas, followed by crystal structures observed in laboratory experiments and in space under microgravity conditions, and finish with an outlook into developing areas — homogeneous nucleation and nonequilibrium crystallization. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of Stationary Plasma Thrusters
Authors: Hagelaar G. J. M. , Bareilles J. , Garrigues L. , Boeuf J.‐P.
Published: August 2004

The discharge in stationary plasma thrusters (SPTs) can be simulated by hybrid discharge models, describing neutrals and ions by the particle in cell technique and electrons by fluid equations, and deducing the electric field from the quasi‐neutrality condition. We discuss the principles, challenges, and benefits of these SPT models. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid review of liquid‐based smears as a quality control measure
Authors: Henderson Sheryl , Stevens Mark , Walker Todd
Published: August 2004

The objective of this study was to investigate the effectiveness of a standardized method of rapid review (RR) of monolayer preparations for the identification of abnormalities, the presence of an endocervical component and infectious agents. A total of 200 ThinPrep (Cytyc, Boxborough, MA) slides representing the spectrum of abnormalities commonly encountered in cervical/vaginal cytologic specimens was retrieved from archive. The study set comprised 129 cases within normal limits (WNL); 36 low‐grade epithelial abnormalities (LGEA); 28 high‐grade epithelial abnormalities (HGEA), including 2 endocervical adenocarcinomas in situ (AIS) and 7 carcinomas. Eighteen false negative (FN) cases were also included for study. Originally missed on initial review, these cases were found to be abnormal on quality control review (17 LGEA; 1 AIS). Commonly encountered infectious agents were represented and included Candida albicans, Trichomonas vaginalis, herpes simplex virus, and Actinomyces. The slides were reviewed using a standardized method of RR (turret technique, for 60 sec) by three experienced screeners masked to the original reference diagnosis. Median sensitivity for LGEA was 70% (range, 67–72%); HGEA, 69% (range, 54–80%); and FN, 65% (range, 56–78%). Specificity remained high, median specificity for LGEA was 95%; HGEA, 97%; and FN, 100%. There was no significant overcalling of any diagnostic category. The chi‐square test at P < 0.05 showed no significant difference between RR and full manual rescreen of the ThinPrep smears in this study. While no statistical difference was proven, the sensitivity measurements for all categories of abnormality were moderate due to the high proportion of atypical cases included into the study set. Abnormalities on the monolayer preparations frequently displayed fewer, smaller groups of disaggregated cells with rounded cytoplasmic outlines that were difficult to discern on RR. Interobserver variation was noted. Monolayers with a paucity of diagnostic cells and those displaying subtle nuclear atypia were often overlooked. Diagn. Cytopathol. 2004;31:141–146. © 2004 Wiley‐Liss, Inc.
The sources of hospital cost variability
Authors: Dormont Brigitte , Milcent Carine
Published: August 2004

Hospital heterogeneity is a major issue in defining a reimbursement system. If hospitals are heterogeneous, it is difficult to distinguish which part of the differences in costs is due to cost containment efforts and which part cannot be reduced, because it is due to other unobserved sources of hospital heterogeneity. In this paper, we apply an econometric approach to analyse hospital cost variability. We use a nested three‐dimensional database (stays‐hospitals‐years) in order to explore the sources of variation in hospital costs, taking into account unobservable components of hospital cost heterogeneity. The three‐dimensional structure of our data makes it possible to identify transitory and permanent components of hospital cost heterogeneity. Econometric estimates are performed on a sample of 7314 stays for acute myocardial infarction (AMI) observed in 36 French public hospitals over the period 1994–1997. Transitory unobservable hospital heterogeneity is far from negligible: its estimated standard error is about 50% of the standard error we estimate for cost variability due to permanent unobservable heterogeneity between hospitals. Copyright © 2004 John Wiley & Sons, Ltd.
Hildebrand and Hansen solubility parameters from Molecular Dynamics with applications to electronic nose polymer sensors
Authors: Belmares M. , Blanco M. , Goddard W. A. , Ross R. B. , Caldwell G. , Chou S.‐H. , Pham J. , Olofson P. M. , Thomas Cristina
Published: August 2004

We introduce the Cohesive Energy Density (CED) method, a multiple sampling Molecular Dynamics computer simulation procedure that may offer higher consistency in the estimation of Hildebrand and Hansen solubility parameters. The use of a multiple sampling technique, combined with a simple but consistent molecular force field and quantum mechanically determined atomic charges, allows for the precise determination of solubility parameters in a systematic way (σ = 0.4 hildebrands). The CED method yields first‐principles Hildebrand parameter predictions in good agreement with experiment [root‐mean‐square (rms) = 1.1 hildebrands]. We apply the CED method to model the Caltech electronic nose, an array of 20 polymer sensors. Sensors are built with conducting leads connected through thin‐film polymers loaded with carbon black. Odorant detection relies on a change in electric resistivity of the polymer film as function of the amount of swelling caused by the odorant compound. The amount of swelling depends upon the chemical composition of the polymer and the odorant molecule. The pattern is unique, and unambiguously identifies the compound. Experimentally determined changes in relative resistivity of seven polymer sensors upon exposure to 24 solvent vapors were modeled with the CED estimated Hansen solubility components. Predictions of polymer sensor responses result in Pearson R2 coefficients between 0.82 and 0.99. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1814–1826, 2004
Macromolecular crowding in biological systems: hydrodynamics and NMR methods
Authors: Bernadó Pau , de la Torre José García , Pons Miquel
Published: August 2004

Most biologically relevant environments involve highly concentrated macromolecular solutions and most biological processes involve macromolecules that diffuse and interact with other macromolecules. Macromolecular crowding is a general phenomenon that strongly affects the transport properties of macromolecules (rotational and translational diffusion) as well as the position of their equilibria. NMR methods can provide information on molecular interactions, as well as on translational and rotational diffusion. In fact, rotational diffusion, through its determinant role in NMR relaxation, places a practical limit on the systems that can be studied by NMR. While in dilute solutions of non‐aggregating macromolecules this limit is set by macromolecular size, in crowded solutions excluded volume effects can have a strong effect on the observed diffusion rates. Hydrodynamic theory offers some insight into the magnitude of crowding effects on NMR observable parameters. Copyright © 2004 John Wiley & Sons, Ltd.
Neutron scattering measurements of intact cells show changes after heat shock consistent with an increase in molecular crowding
Authors: Ford Robert C. , Ruffle Stuart V. , Michalarias Ilias , Beta Ilir , Ramirez‐Cuesta Anibal J. , Li Jichen
Published: August 2004

Molecular crowding has been shown to be important in many cellular processes. The crowded environment in the cell results in a significant proportion of the cellular water being in contact with macromolecules such as proteins and DNA. These interfacial water molecules show a reduced dynamic motion that has been observed with isolated macromolecules using several biophysical techniques. Previously we investigated the inelastic neutron scattering properties of water closely associated with isolated biomolecules, and showed that interfacial water is strongly perturbed, as judged by its energy transfer spectrum. Here we have probed living cells using inelastic and quasielastic neutron scattering. We have found that mild heat stress (‘heat shock’), which causes some proteins to become unfolded in the cell, results in changes in the inelastic neutron scattering in the librational region (45–130 meV). Heat shock also causes a narrowing of the quasielastic scattering peak. These changes can be understood in terms of an increase in the proportion of interfacial water molecules, and a net reduction in proton dynamics. Copyright © 2004 John Wiley & Sons, Ltd.
A comprehensive modeling study of hydrogen oxidation
Authors: Ó Conaire Marcus , Curran Henry J. , Simmie John M. , Pitz William J. , Westbrook Charles K.
Published: August 2004

A detailed kinetic mechanism has been developed to simulate the combustion of H2/O2 mixtures, over a wide range of temperatures, pressures, and equivalence ratios. Over the series of experiments numerically investigated, the temperature ranged from 298 to 2700 K, the pressure from 0.05 to 87 atm, and the equivalence ratios from 0.2 to 6.

Ignition delay times, flame speeds, and species composition data provide for a stringent test of the chemical kinetic mechanism, all of which are simulated in the current study with varying success. A sensitivity analysis was carried out to determine which reactions were dominating the H2/O2 system at particular conditions of pressure, temperature, and fuel/oxygen/diluent ratios. Overall, good agreement was observed between the model and the wide range of experiments simulated. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 603–622, 2004
Synthesis and characterization of macroinitiator‐amino terminated PEG and poly(γ‐benzyl‐L‐glutamate)‐PEO‐poly(γ‐benzyl‐L‐glutamate) triblock copolymer
Authors: Wang Lianyong , Wang Shenguo , Bei Jian zhong
Published: August 2004

Macroinitiator‐amino terminated poly(ethylene glycol) (PEG) (NH2‐PEO‐NH2) was prepared by converting both terminal hydroxyl groups of PEG to more reactive primary amino groups. The synthetic route involved reactions of chloridize, phthalimide and finally hydrazinolysis. Furthermore, poly(γ‐benzyl‐L‐glutamate)‐poly(ethylene oxide)‐poly(γ‐benzyl‐L‐glutamate) (PBLG‐PEO‐PBLG) triblock copolymer was synthesized by polymerization of γ‐benzyl‐L‐glutamate N‐carboxyanhydride (Bz‐L‐GluNCA) using NH2‐PEO‐NH2 as macroinitiator. The resultant NH2‐PEO‐NH2 and triblock copolymer were characterized by FT‐IR, 1H‐NMR and gel permeation chromatography (GPC) techniques. The results demonstrated that the degree of amination of the NH2‐PEO‐NH2 could be up to 1.95. The molecular weight of the PBLG‐PEO‐PBLG triblock copolymer could be adjusted easily by controlling the molar ratio of Bz‐L‐Glu NCA to the macroinitiator NH2‐PEO‐NH2. Copyright © 2004 John Wiley & Sons, Ltd.
Novel epoxy compositions for vibration damping applications
Authors: Ratna D. , Manoj N. R. , Chandrasekhar L. , Chakraborty B. C.
Published: August 2004

Three epoxy compositions have been developed by using polyether amine hardeners having varying chain lengths of polyethers. Unlike normal epoxies, the compositions show low glass transition temperatures (0–45°C). Dynamic mechanical analysis and time–temperature superposition of the isotherms indicate that they have broad and high loss factor values over broad frequency and temperature ranges suggesting their application as viscoelastic materials in constrained layer damping of structural vibrations. Copyright © 2004 John Wiley & Sons, Ltd.
Micellar charge effects as mechanistic criteria in spontaneous hydrolyses of acid chlorides
Authors: Bunton Clifford A.
Published: August 2004

Reaction rates in aqueous micelles, treated in terms of a pseudophase model, depend on transfer equilibria between water and micelles and rate constants in each pseudophase. Rate constants of spontaneous reactions of fully micellar‐bound substrates are independent of transfer and are those in the micellar pseudophase. They depend on its properties as a reaction region and the sensitivity of the reaction to medium effects. For a wide range of spontaneous reactions there are simple relationships between rate constants and properties of the micellar interfacial region, e.g. apparent polarity and head‐group charge, which depend on the reaction mechanism. Aqueous micelles inhibit nucleophilic substitutions at alkyl centers, but rate constants, k+, in cationic micelles are higher than those, k−, in anionic micelles for SN2 reactions and lower for SN1 reactions. Except for nitro derivatives, hydrolyses of substituted benzoyl chlorides are micellar inhibited and k+/k−≈18 for nitro derivative and ca 0.04 for 4‐OMe and Me derivatives, indicating different extents of bond making and breaking in the transition state, but there is no evidence of rate‐limiting dissociation in hydrolyses of the latter. For hydrolyses of substituted benzenesulfonyl chlorides, values of k+/k− decrease from 21 for the 4‐NO2 derivative to 1.1 for the 4‐OMe derivative, indicating dominant bond making. These mechanism‐related charge effects are ascribed to charge asymmetries at micelle–water interfaces and zwitterionic sulfobetaine micelles behave very similarly to cationic micelles in these hydrolyses. Copyright © 2004 John Wiley & Sons, Ltd.
Acid–base behavior of triazoleporphyrazines in proton‐donating media
Authors: Khelevina O. G. , Ferro V. R. , Islyaikin M. K. , Veselkova E. A. , Stryapan M. G. , de la Vega J. M. García
Published: August 2004

The acid–base properties of some peripheral substituted triazoleporphyrazines in proton‐donating media with poor‐donating character were experimentally studied. The substitution of one pyrrole moiety in the porphyrazine‐like compounds by one triazole ring in the triazoleporphyrazines leads to an increase in the basicity. The protonation of the triazoleporphyrazines results in a hypsochromic shift of the Q‐bands in the UV–visible spectra. A DFT study of some selected structural models of the unsubstituted triazoleporphyrazine shows that the protonation strongly influences on the molecular electron structure of this compound and that it occurs preferentially through the nitrogen atom located at position 4 of triazole ring. The protonation through the other basic centers (the triazoleporphyrazine is a multicenter conjugated base) leads to different protonated forms which differ notably in their aromatic character. Therefore, this compound could be considered an intramolecular switch of aromaticity. Copyright © 2004 John Wiley & Sons, Ltd.
Layered coding for satellite‐plus‐terrestrial multipath correlated fading channels
Authors: Levissianos A. , Metaxas G. , Dimitriou N. , Polydoros A.
Published: August 2004

This paper introduces two alternative layered‐coding (LC) structures suitable for a combination of a geostationary (GEO) satellite and a terrestrial system providing multicasting multimedia services. Both schemes include a RAKE receiver and their performance results are presented under realistic satellite and terrestrial channel conditions. The structures are based on mapping the coded bits either onto 8‐PSK symbols or onto QPSK symbols. The LC parameters (such as the interleaver design and the convolutional encoder structures) are analysed and their effect on performance is quantified, especially in cases of highly correlated channels (low vehicular speeds). The various impairments that are associated to the transmission through both terrestrial and satellite correlated fading channels will be taken into account and link level performance results as well as a complexity discussion will be presented. Copyright © 2004 John Wiley & Sons, Ltd.
Formation and Crystal Structure of [(F5TeOXe)+·SO2ClF][Sb(OTeF5)6‐]
Authors: Ulferts Peer , Seppelt Konrad
Published: August 2004

Xe(OTeF5)2 reacts with Sb(OTeF5)3 under the formation of [Xe2(OTeF5)3]+[Sb(OTeF5)6]‐. From SO2ClF solution a yellow solvate [F5TeOXe]+·SO2ClF· [Sb(OTeF5)6]‐ is formed with the crystal data: a = 1028.1(1), b = 1040.9(1), c = 1780.2(3) pm, α = 98.07(1), β = 97.68(1), γ = 105.82(1)°, space group $P {\bar 1}$. The O‐Xe···O fragment is essentially linear (176.1(2)°), and the two Xe‐O distances are quite different 197.1(4) and 242.6(4) pm.
HLA‐B27 lacking associated β2‐microglobulin rearranges to auto‐display or cross‐display residues 169–181: a novel molecular mechanism for spondyloarthropathies
Authors: Luthra-Guptasarma Manni , Singh Balvinder
Published: August 2004

Expression of the MHC class I allelle, HLA‐B27, is correlated with autoimmune disease. The misfolding and association of B27 heavy chains through non‐native disulfide bonds has recently been implicated. Here, we propose that β2m‐free, peptide‐free heavy chains support a helix‐coil transition in the segment leading from the α2 domain to the α3 domain, facilitating rotation of backbone angles around residues 167/168, and allowing residues 169–181 (identical to a known B27 ligand) to loop around and occupy the molecule's own peptide‐binding cleft. Such ‘auto‐display’, occurring either within B27 molecules, or between B27 molecules, could provoke autoimmune attack.
Depensation, probability of fertilization, and the mating system of Atlantic cod (Gadus morhua L.)
Authors: Rowe Sherrylynn , Hutchings Jeffrey A. , Bekkevold Dorte , Rakitin Ana
Published: August 2004

Atlantic cod (Gadus morhua L.) have been severely overexploited and are currently at historic population lows, having declined 90% in the North Sea and 99% off northeast Newfoundland in recent decades. Slow rates of recovery and continuing declines may be attributable to depensation, defined as a reduction in per capita growth rate concomitant with reduced population size. Several potential causes of depensation relate to low mating success and consequent reduced production of offspring. We explore the empirical basis of one of these in Atlantic cod using egg fertilization and male abundance data obtained from 21 experimental populations generated by three independent research programmes. We find support for the hypotheses that (a) fertilization rate declines with abundance and (b) variance in fertilization rate increases as population size declines. The former identifies one potential mechanism underlying depensation in Atlantic cod. The latter has negative genetic consequences for effective population size (Ne), resulting in a decline in the ratio of Ne to census population size (Ne/Nc) with declining abundance. Our results may have general implications for the conservation biology of broadcast-spawning marine fish, particularly those with mating systems similar to that of Atlantic cod.