bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of α1D-adrenergic receptors on shedding of biologically active EGF in freshly isolated lacrimal gland epithelial cells
Authors: Chen LiLi , Hodges Robin R. , Funaki Chika , Zoukhri Driss , Gaivin Robert J. , Perez Dianne M. , Dartt Darlene A.
Published: June 2006

Transactivation of EGF receptors by G protein-coupled receptors is a well-known phenomenon. This process involves the ectodomain shedding of growth factors in the EGF family by matrix metalloproteinases. However, many of these studies employ transformed and/or cultured cells that overexpress labeled growth factors. In addition, few studies have shown that EGF itself is the growth factor that is shed and is responsible for transactivation of the EGF receptor. In this study, we show that freshly isolated, nontransformed lacrimal gland acini express two of the three known α1-adrenergic receptors (ARs), namely, α1B- and α1D-ARs. α1D-ARs mediate phenylephrine (an α1-adrenergic agonist)-induced protein secretion and activation of p42/p44 MAPK, because the α1D-AR inhibitor BMY-7378, but not the α1A-AR inhibitor 5-methylurapidil, inhibits these processes. Activation of p42/p44 MAPK occurs through transactivation of the EGF receptor, which is inhibited by the matrix metalloproteinase ADAM17 inhibitor TAPI-1. In addition, phenylephrine caused the shedding of EGF from freshly isolated acini into the buffer. Incubation of freshly isolated cells with conditioned buffer from cells treated with phenylephrine resulted in activation of the EGF receptor and p42/p44 MAPK. The EGF receptor inhibitor AG1478 and an EGF-neutralizing antibody blocked this activation of p42/p44 MAPK. We conclude that in freshly isolated lacrimal gland acini, α1-adrenergic agonists activate the α1D-AR to stimulate protein secretion and the ectodomain shedding of EGF to transactivate the EGF receptor, potentially via ADAM17, which activates p42/p44 MAPK to negatively modulate protein secretion.
Effects of melanin-concentrating hormone on licking microstructure and brief-access taste responses
Authors: Baird John-Paul , Rios Catalina , Gray Nora Elizabeth , Walsh Caroline Elizabeth , Fischer Shannon Glenora , Pecora Ashley Layne
Published: June 2006

The effects of intracerebroventricular application of melanin-concentrating hormone (MCH) on licking for sucrose, quinine hydrochloride (QHCl), and water solutions were evaluated in two experiments. In experiment 1, rats received 90-min access to sucrose and water solutions after MCH or vehicle microinjection to the third ventricle (3V). MCH increased intake largely through increases in the rate of licking early in the meal and in the mean duration of lick bursts, suggesting an effect on gustatory evaluation. Therefore, in experiment 2, brief access tests were used with a series of sucrose and QHCl concentrations to behaviorally isolate the effects of intracerebroventricular MCH on gustatory evaluation. MCH uniformly increased licking for all sucrose solutions, water, and weak concentrations of QHCl; however, it had no effect on licking for the strongest concentrations of QHCl, which were generally avoided under control conditions. Thus MCH did not produce nonspecific increases in oromotor activity, nor did it change the perceived intensity of the tastants. We conclude that MCH enhanced the gain of responses to normally accepted stimuli at a phase of processing after initial gustatory detection and after the decision to accept or reject the taste stimulus. A comparison of 3V NPY and MCH effects on licking microstructure indicated that these two peptides increased intake via dichotomous behavioral processes; although NPY suppressed measures associated with inhibitory feedback from the gut, MCH appeared instead to enhance measures associated with hedonic taste evaluation.
Transformation of Vestibular Signals Into Motor Commands in the Vestibuloocular Reflex Pathways of Monkeys
Authors: Ramachandran Ramnarayan , Lisberger Stephen G.
Published: June 2006

Parallel pathways mediate the rotatory vestibuloocular reflex (VOR). If the VOR undergoes adaptive modification with spectacles that change the magnification of the visual scene, signals in one neural pathway are modified, whereas those in another are not. By recording the responses of vestibular afferents and abducens neurons for vestibular oscillations at frequencies from 0.5 to 50 Hz, we have elucidated how vestibular signals are processed in the modified versus unmodified VOR pathways. For the small stimuli we used (±15°/s), the afferents with the most regular spontaneous discharge fired throughout the cycle of oscillation even at 50 Hz, whereas afferents with more irregular discharge showed phase locking. For all afferents, the firing rate was in phase with stimulus head velocity at low frequencies and showed progressive phase lead as frequency increased. Sensitivity to head velocity increased steadily as a function of frequency. Abducens neurons showed highly regular spontaneous discharge and very little evidence of phase locking. Their sensitivity to head velocity during the VOR was relatively flat across frequencies; firing rate lagged head velocity at low frequencies and shifted to large phase leads as stimulus frequency increased. When afferent responses were provided as inputs to a two-pathway model of the VOR, the output of the model reproduced the responses of abducens neurons if the unmodified and modified VOR pathways had frequency-dependent internal gains and included fixed time delays of 1.5 and 9 ms. The phase shifts predicted by the model provide fingerprints for identifying brain stem neurons that participate in the modified versus unmodified VOR pathways.
Origin of Facilitation of Motor-Evoked Potentials After Paired Magnetic Stimulation: Direct Recording of Epidural Activity in Conscious Humans
Authors: Di Lazzaro V. , Pilato F. , Oliviero A. , Dileone M. , Saturno E. , Mazzone P. , Insola A. , Profice P. , Ranieri F. , Capone F. , Tonali P. A. , Rothwell J. C.
Published: June 2006

A magnetic transcranial conditioning stimulus given over the motor cortex at intensities below active threshold for obtaining motor-evoked potentials (MEPs) facilitates EMG responses evoked at rest in hand muscles by a suprathreshold magnetic stimulus given 10–25 ms later. This is known as intracortical facilitation (ICF). We recorded descending volleys produced by single and paired magnetic motor cortex stimulation through high cervical epidural electrodes implanted for pain relief in six conscious patients. At interstimulus intervals (ISIs) of 10 and 15 ms, although MEP was facilitated, there was no change in the amplitude or number of descending volleys. An additional I wave sometimes was observed at 25 ms ISI. In one subject, we also evaluated the effects of reversing the direction of the induced current in the brain. At 10 ms ISI, the facilitation of the MEPs disappeared and was replaced by slight suppression; at 2 ms ISI, there was a pronounced facilitation of epidural volleys. Subsequent experiments on healthy subjects showed that a conditioning stimulus capable of producing ICF of MEPs had no effect on the EMG response evoked by transmastoidal electrical stimulation of corticospinal tract. We conclude that ICF occurs because either 1) the conditioning stimulus has a (thus far undetected) effect on spinal cord excitability that increases its response to the same amplitude test volley or 2) that it can alter the composition (but not the amplitude) of the descending volleys set up by the test stimulus such that a larger proportion of the activity is destined for the target muscle.
Large-Eddy Simulations of Trade Wind Cumuli: Investigation of Aerosol Indirect Effects
Authors: Xue Huiwen , Feingold Graham
Published: June 2006

The effects of aerosol on warm trade cumulus clouds are investigated using a large-eddy simulation with size-resolved cloud microphysics. It is shown that, as expected, increases in aerosols cause a reduction in precipitation and an increase in the cloud-averaged liquid water path (LWP). However, for the case under study, cloud fraction, cloud size, cloud-top height, and depth decrease in response to increasing aerosol concentration, contrary to accepted hypotheses associated with the second aerosol indirect effect. It is found that the complex responses of clouds to aerosols are determined by competing effects of precipitation and droplet evaporation associated with entrainment. As aerosol concentration increases, precipitation suppression tends to maintain the clouds and lead to higher cloud LWP, whereas cloud droplets become smaller and evaporate more readily, which tends to dissipate the clouds and leads to lower cloud fraction, cloud size, and depth. An additional set of experiments with higher surface latent heat flux, and hence higher LWP and drizzle rate, was also performed. Changes in cloud properties due to aerosols have the same trends as in the base runs, although the magnitudes of the changes are larger. Evidence for significant stabilization (or destabilization) of the subcloud layer due to drizzle is not found, mainly because drizzling clouds cover only a small fraction of the domain. It is suggested that cloud fraction may only increase with increasing aerosol loading for larger clouds that are less susceptible to entrainment and evaporation. Finally, it is noted that at any given aerosol concentration the dynamical variability in bulk cloud parameters such as LWP tends to be larger than the aerosol-induced changes in these parameters, indicating that the second aerosol indirect effect may be hard to measure in this cloud type. The variability in cloud optical depth is, however, dominated by changes in aerosol, rather than dynamics.
Oncogenic NRAS rapidly and efficiently induces CMML- and AML-like diseases in mice
Authors: Parikh Chaitali , Subrahmanyam Ramesh , Ren Ruibao
Published: June 2006

Activating mutations in RAS, predominantly NRAS, are common in myeloid malignancies. Previous studies in animal models have shown that oncogenic NRAS is unable to induce myeloid malignancies effectively, and it was suggested that oncogenic NRAS might only act as a secondary mutation in leukemogenesis. In this study, we examined the leukemogenicity of NRAS using an improved mouse bone marrow transduction and transplantation model. We found that oncogenic NRAS rapidly and efficiently induced chronic myelomonocytic leukemia (CMML)– or acute myeloid leukemia (AML)– like disease in mice, indicating that mutated NRAS can function as an initiating oncogene in the induction of myeloid malignancies. In addition to CMML and AML, we found that NRAS induced mastocytosis in mice. This result indicates that activation of the RAS pathway also plays an important role in the pathogenesis of mastocytosis. The mouse model for NRAS leukemogenesis established here provides a system for further studying the molecular mechanisms in the pathogenesis of myeloid malignancies and for testing relevant therapies.
Investigating the role of small, acid-soluble spore proteins (SASPs) in the resistance of Clostridium perfringens spores to heat
Authors: Raju Deepa , Waters Michael , Setlow Peter , Sarker Mahfuzur R
Published: June 2006

Background

Clostridium perfringens type A food poisoning is caused by enterotoxigenic C. perfringens type A isolates that typically possess high spore heat-resistance. The molecular basis for C. perfringens spore heat-resistance remains unknown. In the current study, we investigated the role of small, acid-soluble spore proteins (SASPs) in heat-resistance of spores produced by C. perfringens food poisoning isolates.

Results

Our current study demonstrated the presence of all three SASP-encoding genes (ssp1, 2 and 3) in five surveyed C. perfringens clinical food poisoning isolates. β-Glucuronidase assay showed that these ssp genes are expressed specifically during sporulation. Consistent with these expression results, our study also demonstrated the production of SASPs by C. perfringens food poisoning isolates. When the heat sensitivities of spores produced by a ssp3 knock-out mutant of a C. perfringens food poisoning isolate was compared with that of spores of the wild-type strain, spores of the ssp3 mutant were found to exhibit a lower decimal reduction value (D value) at 100°C than exhibited by the spores of wild-type strain. This effect was restored by complementing the ssp3 mutant with a recombinant plasmid carrying wild-type ssp3, suggesting that the observed differences in D values between spores of wild-type versus ssp3 mutant was due to the specific inactivation of ssp3. Furthermore, our DNA protection assay demonstrated that C. perfringens SASPs can protect DNA from DNase I digestion.

Conclusion

The results from our current study provide evidences that SASPs produced by C. perfringens food poisoning isolates play a role in protecting their spores from heat-damage, which is highly significant and relevant from a food safety perspective. Further detailed studies on mechanism of action of SASPs from C. perfringens should help in understanding the mechanism of protection of C. perfringens spores from heat-damage.
Comparison of adjuvant and neoadjuvant chemotherapy in the management of advanced ovarian cancer: a retrospective study of 574 patients
Authors: Inciura Arturas , Simavicius Andrius , Juozaityte Elona , Kurtinaitis Juozas , Nadisauskiene Ruta , Svedas Eimantas , Kajenas Skirmantas
Published: June 2006

Background

There is a lack of clinical data on the validity of neoadjuvant chemotherapy in the treatment of ovarian cancer. The aim of this study was to compare the impact of the adjuvant and neoadjuvant chemotherapy regimens on the clinical outcomes in patients with advanced ovarian cancer.

Methods

We performed a retrospective analysis of 574 patients with advanced ovarian cancer admitted to four Lithuanian oncogynaecology departments during 1993–2000. The conventional combined treatment of cytoreductive surgery and platinum-based chemotherapy was applied to both the group that underwent neoadjuvant chemotherapy (n = 213) and to the control group (n = 361). The selection criterion for neoadjuvant chemotherapy was large extent of the disease. Overall and progression-free survival rates and survival medians were calculated using life tables and the Kaplan-Meier method.

Results

There was no difference in median overall survival between stage III patients treated with adjuvant chemotherapy and neoadjuvant chemotherapy (25.9 months vs. 29.3 months, p = 0.2508) and stage IV patients (15.4 months vs. 14.9 months, p = 0.6108). Similarly, there was no difference in median progression-free survival between stage III patients treated with adjuvant chemotherapy and neoadjuvant chemotherapy (15.7 months vs. 17.5 months, p = 0.1299) and stage IV patients (8.7 months vs. 8.2 months, p = 0.1817). There was no difference in the rate of the optimal cytoreductive surgery between patients who underwent the neoadjuvant chemotherapy and patients primarily treated with surgery (n = 134, 63% vs. n = 242, 67%, respectively).

Conclusion

There was no difference in progression-free or overall survival and in the rate of optimal cytoreductive surgery between the neoadjuvant and adjuvant chemotherapy groups despite the fact that patients receiving neoadjuvant chemotherapy had a more extensive disease. Multivariate analysis failed to prove that neoadjuvant chemotherapy could be considered as an independent prognostic factor for survival, and the findings need to be investigated in the future prospective randomised studies.
Secondary structure spatial conformation footprint: a novel method for fast protein structure comparison and classification
Authors: Zotenko Elena , O'Leary Dianne P , Przytycka Teresa M
Published: June 2006

Background

Recently a new class of methods for fast protein structure comparison has emerged. We call the methods in this class projection methods as they rely on a mapping of protein structure into a high-dimensional vector space. Once the mapping is done, the structure comparison is reduced to distance computation between corresponding vectors. As structural similarity is approximated by distance between projections, the success of any projection method depends on how well its mapping function is able to capture the salient features of protein structure. There is no agreement on what constitutes a good projection technique and the three currently known projection methods utilize very different approaches to the mapping construction, both in terms of what structural elements are included and how this information is integrated to produce a vector representation.

Results

In this paper we propose a novel projection method that uses secondary structure information to produce the mapping. First, a diverse set of spatial arrangements of triplets of secondary structure elements, a set of structural models, is automatically selected. Then, each protein structure is mapped into a high-dimensional vector of "counts" or footprint, where each count corresponds to the number of times a given structural model is observed in the structure, weighted by the precision with which the model is reproduced. We perform the first comprehensive evaluation of our method together with all other currently known projection methods.

Conclusion

The results of our evaluation suggest that the type of structural information used by a projection method affects the ability of the method to detect structural similarity. In particular, our method that uses the spatial conformations of triplets of secondary structure elements outperforms other methods in most of the tests.
Chemotherapy Options for Patients With Metastatic or Recurrent Squamous Cell Carcinoma of the Head and Neck
Authors: Colevas A. Dimitrios
Published: June 2006

The purpose of this review is to provide readers with guidance concerning treatment of patients with advanced, recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN) in the context of clinical trial data. We discuss issues surrounding the treatment of patients with SCCHN, with an emphasis on recommendations based on results from phase II and III clinical trials published since 1980. Many options exist for the treatment of patients with SCCHN. The most important decisions involve determining which patients are in need of treatment and which are most likely to benefit from treatment. Although many chemotherapy treatments have been shown to induce responses, survival improvement remains an unfulfilled goal. Definitive data do not exist on the effects of chemotherapy on quality of life or progression-free survival as measures of clinical benefit in this setting. Performance status, history of prior treatment, extent of tumor, and need for palliation are the most important factors in the decision to treat a patient with chemotherapy for incurable SCCHN. Single-agent treatment with conventional doses of methotrexate remains a standard for most patients with advanced, recurrent or metastatic SCCHN. Cisplatin plus fluorouracil, cisplatin plus a taxane, and single-agent taxane are the most widely studied alternatives. There is a need for further trials with end points other than overall survival or tumor response in this patient population. Guidelines for patient selection and treatment options are provided.
Signal analysis and weighted polynomial approximation
Authors: Ky Nguyen Xuan
Published: June 2006

We present applications of Hermite polynomials in
signal analysis. Among other result, we give a characterization of the
so-called time-frequency window functions in terms of the Hermite--Fourier
coefficients, a Bernstein-type theorem for the best approximations of window
functions by Hermite-functions, time-frequency approximations. Some analogues
for Hankel-transforms will also be considered.
A surprising property of the Barabási--Albert random tree
Authors: Móri Tamás F.
Published: June 2006

In a one-parameter generalization of the
Barabási--Albert random tree the asymptotic degree distribution on the lower
levels is different from that in the whole graph.
Fear of Acquaintance Versus Stranger Rape as a “Master Status”: Towards Refinement of the “Shadow of Sexual Assault”
Authors: Wilcox Pamela , Jordan Carol E. , Pritchard Adam J.
Published: June 2006

Using a sample of 1,010 women from a southeastern state university, we explore whether associations between fear of sexual assault and other crime-specific fears vary based on presumed victim-offender relationship. More specifically, we assess the extent to which fear of stranger- and acquaintance-perpetrated sexual assaults differ in the extent to which they are correlated with fear of other crime victimizations. Multivariate logistic regression analysis revealed that both fear of stranger-perpetrated sexual assault and fear of acquaintance-perpetrated sexual assault were positively associated with nearly all other crime-specific fears under examination. However, associations were particularly strong between fear of sexual assault by a stranger and fear of other stranger-perpetrated crimes. Findings have significant implications for how academic institutions should comprehensively address direct and indirect negative influences of violence against college women.
Stochastic Interest Rates and Autoregressive Integrated Moving Average Processes
Authors: Dhaene Jan
Published: June 2006

A practical method is developed for computing moments of insurance functions when interest rates are assumed to follow an autoregressive integrated moving average process.
The Claims Reserving Problem in Non-Life Insurance: Some Structural Ideas
Authors: Arjas Elja
Published: June 2006

We present some relatively simple structural ideas about how probabilistic modeling, and in particular, the modern theory of point processes and martingales, can be used in the estimation of claims reserves.
Maximizing Dividends without Bankruptcy
Authors: Gerber Hans U. , Shiu Elias S.W. , Smith Nathaniel
Published: June 2006

Consider the classical compound Poisson model of risk theory, in which dividends are paid to the shareholders according to a barrier strategy. Let b* be the level of the barrier that maximizes the expectation of the discounted dividends until ruin. This paper is inspired by Dickson and Waters (2004). They point out that the shareholders should be liable to cover the deficit at ruin. Thus, they consider b0, the level of the barrier that maximizes the expectation of the difference between the discounted dividends until ruin and the discounted deficit at ruin. In this paper, b* and b0 are compared, when the claim amount distribution is exponential or a combination of exponentials.
Vehicle and Fleet Random Effects in a Model of Insurance Rating for Fleets of Vehicles
Authors: Angers Jean-François , Desjardins Denise , Dionne Georges , Guertin François
Published: June 2006

We are proposing a parametric model to rate insurance for vehicles belonging to a fleet. The tables of premiums presented take into account past vehicle accidents, observable characteristics of the vehicles and fleets, and violations of the road-safety code committed by drivers and carriers. The premiums are also adjusted according to accidents accumulated by the fleets over time. The proposed model accounts directly for explicit changes in the various components of the probability of accidents. It represents an extension of bonus malus-type automobile insurance models for individual premiums (Lemaire, 1985; Dionne and Vanasse, 1989 and 1992; Pinquet, 1997 and 1998; Frangos and Vrontos, 2001; Purcaru and Denuit, 2003). The extension adds a fleet effect to the vehicle effect so as to account for the impact that the unobservable characteristics or actions of carriers can have on truck accident rates. This form of rating makes it possible to visualize what impact the behaviors of owners and drivers can have on the predicted rate of accidents and, consequently, on premiums. The results are compared to those of the semiparametric approach.
Portfolio Choice and Estimation Risk. A Comparison of Bayesian to Heuristic Approaches
Authors: Ulf Herold , Raimond Maurer
Published: June 2006

Estimation risk is known to have a huge impact on mean/variance optimized portfolios, which is one of the primary reasons to make standard Markowitz optimization unfeasible in practice. This issue has attracted new interest in the last years, and several approaches to incorporate estimation risk into portfolio selection have been developed only recently. In this article, we review these approaches as well as some older ones and compare them in an empirical out-of-sample study. The approaches can be classified along two criteria. First, we can differentiate heuristic approaches (restricting portfolio weights and employing simulation techniques) and those based on Bayesian statistics (shrinking the portfolios towards a pre-determined target). Second, the assumptions about the return-generating process differ, either assuming returns to be IID distributed or to be partly predictable. The central result of our empirical study is that all of the IID approaches, whether they account for estimation risk or not, are not superior to simple investment strategies like holding the market portfolio. A risk-adjusted outperformance is possible only if sample means are substituted with conditional expected return estimates. Furthermore, the Bayesian approaches reduce turnover and stabilize portfolio weights.
Neuroscience and adult learning
Authors: Cozolino Louis , Sprokay Susan
Published: June 2006

This chapter is an introduction to how the learning process changes the brain, with special attention to the facilitative role of the adult educator/mentor.
Brain self‐repair in psychotherapy: Implications for education
Authors: Ross Colin A.
Published: June 2006

The educational process called psychotherapy offers a model for brain repair through learning.
Meaningful learning and the executive functions of the brain
Authors: Caine Geoffrey , Caine Renate Nummela
Published: June 2006

Research on the executive functions of the brain supports a constructivist, experiential approach to teaching and learning.
The neuroscience of the mentor‐learner relationship
Authors: Johnson Sandra
Published: June 2006

Social cognitive neuroscience can offer a scientific framework for developmental learning in the mentorlearner relationship.
Factors affecting the formation of fingering in water‐assisted injection‐molded thermoplastics
Authors: Liu Shih‐Jung , Lin Shih‐Po
Published: June 2006

Water‐assisted injection‐molding technology has received extensive attention in recent years, due to the lightweight of plastic parts, relatively low‐resin cost per part, faster cycle time, and flexibility in the design and manufacture. However, there are still some unsolved problems that confound the overall success of this technology. One of these is the water “fingering” phenomenon, in which the water bubbles penetrate outside designed water channels and form finger‐shape branches. This study has investigated the effects of various processing parameters on the formation of fingering in water‐assisted injection‐molded thermoplastic parts. Both amorphous and semicrystalline polymers were used to mold the parts. The influence of water channel geometry, including aspect ratio and fillet geometry, on the fingering was also investigated. It was found that water‐assisted injection‐molded amorphous materials gave less fingering, while molded semicrystalline parts gave more fingering when compared to those molded by gas‐assisted injection molding. For the water channels used in this study, the channels with a rib on the top produced parts with the least water fingering. Water fingering in molded parts decreases with the height‐to‐thickness ratio of the channels. The water pressure, water injection delay time and short‐shot size were found to be the principal parameters affecting the formation of water fingering. In addition, a numerical simulation based on the transient heat conduction model was also carried out to help better explain the mechanism for the formation of fingering in water‐assisted injection‐molded thermoplastics. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 98–108, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20062
Processing of PEMFC membranes by extrusion: Part 1. Sulfonated polysulfone in acid form
Authors: Bébin Philippe , Galiano Hervé
Published: June 2006

Sulfonated polysulfone (sPSU) was considered as an alternative material for low‐temperature proton exchange membrane fuel cell. The possibility of manufacturing sPSU films by a continuous extrusion process is examined. The use of a plasticizer (polyethyleneglycol, PEG) is essential to decrease the glass transition temperature of the material in order to make it processable in the melt state. However, the acidic character of sPSU induces significant degradation of the sPSU/PEG mixtures even at low temperatures (120°C), necessitating the use of high amounts of PEG to perform the extrusion of sPSU film. In these experiments, 30–40% of plasticizer had to be used to successfully produce a film, but a high level of porosity was produced in the membrane after removing the PEG. Although porosity significantly improves the proton conductivity of the membranes, in a fuel cell, the fuel crossover also increases as a result. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 121–126, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20066
Processing of sulfonated polysulfone for PEMFC membrane applications: Part 2. Polymer in salt form
Authors: Bébin Philippe , Galiano Hervé
Published: June 2006

The possibility of manufacturing sulfonated polysulfone (sPSU) membranes by an extrusion process is explored for low‐temperature proton exchange membrane fuel cell applications. Because the acid form of sPSU is not suitable for melt‐phase processing, the use of the salt form of the polymer was considered, as sulfonate groups are much less reactive than sulfonic acid groups. This form of sPSU makes it possible to use an extrusion process with the help of a suitable plasticizer, such as poly(ethyleneglycol) (PEG). The residual porosity of the film, induced by removing the soluble PEG with water, was found to improve the proton conductivity of the membrane. The membrane fabrication process has a prominent effect on the final properties of the film. For the same composition, a solvent‐casting procedure can produce membranes with proton conductivity twice as high as that attainable with a melt‐phase process. However, extruded membranes exhibit a greater longevity than do cast membranes. At the same time, the proton conductivity of extruded membranes is less dependent on the ion‐exchange capacity of the polymer. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 127–133, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20067
The expanding panorama of split hand foot malformation
Authors: Basel Donald , Kilpatrick Michael W. , Tsipouras Petros
Published: June 2006

The split hand/foot malformation is a developmental defect of the extremities resulting from errors in the initiation and maintenance of the apical ectodermal ridge. The phenotype is genetically heterogeneous, and it can be identified either as an isolated phenotypic manifestation or as a constituent component of a malformation syndrome. This overview describes the clinical phenotype, related animal models, and the evolving genetic heterogeneity of the malformation. © 2006 Wiley‐Liss, Inc.
A new detection method for ATRX gene mutations using a mismatch‐specific endonuclease
Authors: Wada Takahito , Fukushima Yoshimitsu , Saitoh Shinji
Published: June 2006

X‐linked α‐thalassemia/mental retardation syndrome (ATR‐X, OMIM 301040) is a syndromic form of X‐linked mental retardation (XLMR). It is caused by a mutation in the ATRX gene, which is also involved in other syndromic forms of XLMR as well as in non‐syndromic XLMR, both in males and in females. To analyze the full range of disease‐causing mutations for genetic counseling and to establish phenotype–genotype correlations, we have established a new screening method for mutations in the ATRX gene, which uses mismatch‐specific endonuclease. We applied this method to confirm 13 known mutations in our patients, some of which have been difficult to be demonstrated by conventional denaturing high‐performance liquid chromatography. Furthermore, we found four additional mutations in four ATR‐X patients whose clinical diagnosis had not been confirmed at the molecular level. In this method, experimental conditions do not need to be altered depending on mutation sites, and it should be the alternative method for mutation screening. © 2006 Wiley‐Liss, Inc.
Cover Picture: Chiral Borromeates (Angew. Chem. Int. Ed. 25/2006)
Authors: Pentecost Cari D. , Peters Andrea J. , Chichak Kelly S. , Cave Gareth W. V. , Cantrill Stuart J. , Stoddart J. Fraser
Published: June 2006

Chirality is transferred from 12 stereogenic centers, all of the same chirality, to the six templating zinc(II) ions in each enantiomer of an optically active Borromeate. Recognizing that the three‐component Borromean link is topologically achiral, J. F. Stoddart et al. describe in their Communication on page 4099 ff. the dynamic stereospecific synthesis of both all‐R and all‐S enantiomers of the Borromeate and report the X‐ray crystal structure of the all‐R enantiomer.
Trauma, ideology, and the future of democracy
Authors: Hollander Nancy Caro
Published: June 2006

This article uses aspects of psychoanalytic theory to explain how the convergence of unconscious mechanisms and ideology in the post‐9/11 political culture enabled the US government to secure consensual support for domestic and foreign policies that attack democracy and make the world more dangerous rather than safer. The author argues that the Kleinian and Lacanian traditions, along with critical social theory, shed light on the psychopolitical dynamics of a bystander population and help to explain the psychic and social factors that permit the emergence of critical social conscience. Copyright © 2006 John Wiley & Sons, Ltd.
Die Tragfähigkeit verleimter Brettschichtholzbinder in Abhängigkeit von der Temperatureinwirkung
Authors: Falkner Horst , Teutsch Manfred
Published: June 2006

Bei einem Bauvorhaben wurde als Tragstruktur für die Glasfassade eine Holzleimstruktur eingesetzt. Da nicht auszuschließen war, daß die Temperatur der Fassadenhölzer unter Sonneneinwirkung eine Größe von 60 °C erreichen konnte, wurde der Einfluß der Temperatur auf die Tragfähigkeit der Leimverbindung untersucht. Hierzu wurden aus dem Bauvorhaben einige Proben entnommen und am iBMB (Institut für Baustoffe, Massivbau und Brandschutz) der TU Braunschweig unter Variation der Bauteiltemperatur nach DIN 52186 geprüft. Dabei ergab sich bis zu einer Temperatur von 30 °C keine Veränderung der Tragfähigkeit. Bei höherer Temperatureinwirkung von 80 °C betrug die Tragfähigkeit nur noch 30% derjenigen unter Normaltemperatur. Hier wurde der Bruch durch ein Versagen der Leimfuge eingeleitet.
Antihypertensive activity of chitin derivatives
Authors: Je Jae‐Young , Park Pyo‐Jam , Kim Bokyung , Kim Se‐Kwon
Published: June 2006

To develop angiotensin I converting enzyme (ACE) inhibitory chitin derivatives based on the properties of ACE inhibitors, chitins with different degree of deacetylation were chemically modified by grafting 2‐chloroethylamino hydrochloride onto chitin at the C‐6 position. Three kinds of chitin derivatives were prepared and designated as aminoethyl‐chitin (AEC) with 10% degree of deacetylation, aminoethyl‐chitin with 50% degree of deacetylation (AEC50), and aminoethyl‐chitin with 90% degree of deacetylation (AEC90). IC50 values of three chitin derivatives on ACE were 0.064 μM (AEC), 0.038 μM (AEC50), and 0.103 μM (AEC90). The results of Dixon plots revealed that AEC50 was a competitive inhibitor, and the inhibition constant (Ki) value was 0.021 μM. In addition, the antihypertensive effect of AEC50 on spontaneously hypertensive rats (SHR) was evaluated, and the result showed that it effectively decreased systolic blood pressure (SBP) in a dose‐dependent manner. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 250–254, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Resolution of protein‐losing enteropathy after radiofrequency perforation and subsequent stent implantation for relief of complete occlusion of a redirected left superior vena cava
Authors: Schaeffler Rainer , Beerbaum Phillip , Peuster Matthias
Published: June 2006

The application of radiofrequency (RF) technologies in the treatment of congenital heart defects has provided a safe and effective alternative to conventional therapies in the restoration of vascular patency for a variety of arterial and venous occlusions. This report concerns an 8‐year old girl that developed protein‐losing enteropathy and elevated central venous pressure after occlusion of a surgically redirected anomalous draining left superior vena cava (SVC). Cardiac catheterization revealed complete obstruction of the anastomosis of the SVC into the coronary sinus. Transcatheter recanalization by RF perforation and subsequent stent implantation led to the restoration of upper venous blood flow and the resolution of her symptoms. © 2006 Wiley‐Liss, Inc.
Delivery sheath tear after modification for ASD closure
Authors: Hoyer Mark H.
Published: June 2006

During transcatheter closure of an atrial septal defect with insufficient aortic rim, a standard delivery sheath was modified by cutting a bevel at the distal tip to improve device orientation. The sheath split longitudinally when attempting to recapture the closure device. Troubleshooting allowed a device to be implanted successfully. Pitfalls regarding our sheath modification and methods to overcome prolapse of the left atrial disk into the right atrium are discussed. © 2006 Wiley‐Liss, Inc.
Use of Dipicolinate‐Based Complexes for Producing Ion‐Imprinted Polystyrene Resins for the Extraction of Yttrium‐90 and Heavy Lanthanide Cations
Authors: Chauvin Anne‐Sophie , Bünzli Jean‐Claude G. , Bochud François , Scopelliti Rosario , Froidevaux Pascal
Published: June 2006

Highly selective separation of yttrium (and lanthanides) is of interest for the design of radiopharmaceuticals, and an efficient method based on the ion‐imprinting concept is proposed here. The synthesis and structural, thermodynamic and photophysical characterization of complexes of trivalent yttrium and lanthanides with two new vinyl derivatives of dipicolinic acid, HL1 and L2, are described. The feasibility of using ion‐imprinted resins for yttrium and lanthanide separation is demonstrated. The resins were obtained by copolymerization with styrene and divinylbenzene and subsequent acid treatment to remove the metal ion. High‐resolution Eu luminescence experiments revealed that the geometry of the complexation sites is well preserved in the imprinted polymers. The ion‐imprinted polymer based on HL1 proved to be particularly well adapted for yttrium extraction, having a sizeable capacity (8.9±0.2 mg g−1 resin) and a fast rate of extraction (t1/2=1.7 min). In addition, lighter and heavier lanthanide ions are separated. Finally, the resin displays high selectivity for yttrium and lanthanide cations against alkali and alkaline earth metals. For instance, in a typical experiment, 10 mg of yttrium was extracted from 5 g of milk ash sample by 2 g of the resin. The good separation properties displayed by the resin based on HL1 open interesting perspectives for the production of highly pure 90Y and radiolanthanides for medical applications, and for trace analysis of these radiochemicals in food and in the environment.
Investigations on Organo–Sulfur–Nitrogen Rings and the Thiocyanogen Polymer, (SCN)x
Authors: Bowman W. Russell , Burchell Colin J. , Kilian Petr , Slawin Alexandra M. Z. , Wormald Philip , Woollins J. Derek
Published: June 2006

The synthesis and full characterisation of a series of 1,2,4‐thiadiazoles is reported. (SCN)x has been studied by a variety of techniques and the data compared with 1,2,4‐thiadiazole and 1,2,4‐dithiazoles. The observed data suggest that the polymer consists of 1,2,4‐dithiazole rings linked by nitrogen atoms. For (SCN)x, the MALDI‐TOF mass spectroscopy showed a parent ion at 1149 and a series of peaks with (SCN)2 repeat units (116 m/z); this result implies that (SCN)2 may be the monomer unit of the polymer. Its IR spectrum shows a very broad peak with maximum at 1134 cm−1 consisting of several overlapping peaks in the same region as ring vibrations for 1,2,4‐thiadiazole and 1,2,4‐dithiazole compounds. Peaks in the Raman spectrum in the range 400–480 cm−1 support the presence of disulfide units within the polymer. The solid‐state 13C NMR (99 % 13C‐labelled) spectrum is dominated by two singlets of equal intensity at approximately 187 and 184 ppm with low intensity peaks in the range 152–172 ppm, in approximately the same range as both 1,2,4‐thiadiazoles and 1,2,4‐dithiazoles. The solid‐state 15N NMR (99 % 15N labelled) spectrum displays two major peaks of similar intensity at 236.9 and 197.2 ppm, which are clearly very different environments to those observed in bis(3‐bromo‐1,2,4‐thiadiazol‐5‐yl) disulfide, but similar to 1,2,4‐dithiazoles. The X‐ray structures of seven C‐S‐N systems are reported. Preliminary studies on (SeCN)x suggest that literature references to this polymer may be in error with the red solid actually being red selenium.
Direct exosome stimulation of peripheral humanT cells detected by ELISPOT
Authors: Admyre Charlotte , Johansson Sara M. , Paulie Staffan , Gabrielsson Susanne
Published: June 2006

Exosomes from APC are nano‐vesicles that can induce antigen‐specific T cell responses and are presently explored as therapeutic tools in different clinical settings. Investigations of the capacity of exosomes to stimulate T cells in vitro have mostly been performed on T cell hybridomas, clones or lines. Whether exosomes can stimulate T cells directly or need the presence of dendritic cells (DC) is debated. We could detect exosome‐induced antigen‐specific CD8+ T cell responses in peripheral blood from humans. Exosomes from monocyte‐derived DC (MDDC) were loaded with a mix of 23 immunogenic peptides from EBV, CMV and influenza virus, and added to autologous peripheral CD8+ T cells. IFN‐γ‐producing cells were detected by enzyme‐linked immunospot assay (ELISPOT). MDDC‐exosomes induced IFN‐γ production in CD8+ T cells without addition of DC. The response was exosome dose dependent, and dependent on exosomal MHC class I. Furthermore, we detected an enhanced T cell stimulatory capacity by exosomes from lipopolysaccharide‐matured MDDC compared to exosomes from immature MDDC. Exosomes could also induce TNF‐α production. These results show, for the first time, that exosomes can directly stimulate human peripheral CD8+ T cells in an antigen‐specific manner and that ELISPOT is a suitable method for detecting exosome‐induced peripheral T cell responses. This system may provide a useful tool when developing exosomes as therapeutic agents.
cIAP‐2 and survivin contribute to cytokine‐mediated delayed eosinophil apoptosis
Authors: Vassina Ekatherina M. , Yousefi Shida , Simon Dagmar , Zwicky Caroline , Conus Sébastien , Simon Hans‐Uwe
Published: June 2006

The exact molecular mechanisms leading to delayed apoptosis, a phenomenon frequently observed in eosinophil inflammatory responses, remain largely unknown. Here, we show that cultured eosinophils purified from blood of hypereosinophilic syndrome (HES) patients exhibit delayed spontaneous death and relative resistance towards ceramide‐ but not CD95‐mediated death. The subsequent investigation of members of the inhibitor of apoptosis (IAP) family revealed that HES but not normal eosinophils expressed high levels of cellular IAP‐2 (cIAP‐2) and survivin. The eosinophil hematopoietins IL‐3, IL‐5, and GM‐CSF increased the expression of cIAP‐2 and survivin in normal eosinophils in vitro. In the blood of HES patients, we observed increased concentrations of IL‐3 and/or IL‐5, suggesting that these cytokines are, at least partially, responsible for the elevated levels of cIAP‐2 and survivin in the eosinophils of these patients. Utilizing a cell‐free system in which caspase‐3 was activated in eosinophil cytosolic extracts by addition of cytochrome c and immunodepletion of cIAP‐2 or survivin resulted in accelerated caspase activation. These data suggest that some members of the IAP family including survivin are regulated by survival cytokines and inhibit the caspase cascade in HES eosinophils. The cytokine‐dependent mechanism of delayed eosinophil apoptosis described here may also apply to other eosinophilic diseases.
Hillslope runoff and erosion as affected by rolled erosion control systems: a field study
Authors: Sutherland Ross A. , Ziegler Alan D.
Published: June 2006

A replicated field study using rainfall simulation and overland flow application was conducted in central Oahu, Hawaii, on a clay‐dominated Oxisol with a 9% slope. Three main treatment groups were examined: a bare treatment, a group of four rolled erosion control systems (RECSs) with open weave designs, and a group of five randomly oriented fibre RECSs. A total of 1122 measurements of runoff and erosion were made to examine treatment differences and to explore temporal patterns in runoff and sediment flux.

All erosion control systems significantly delayed the time required to generate plot runoff under both simulated rainfall (35 mm h−1) and the more intense trickle flow application (114 mm h−1). Once runoff was generated during the rainfall application phase, the bare treatment runoff coefficients were significantly lower than those from the two groups of RECSs, as surface seal disruption by rilling is inferred to have enhanced infiltration in the bare treatments. During the more intense phase of overland flow application, the reverse pattern was observed. Interrill contributing‐area roughness was reduced on the bare treatment, facilitating increased runoff to well‐developed rill networks. Meanwhile, the form roughness associated with the RECSs delayed interrill flow to the poorly organized rills that formed under some of the RECSs.

Regardless of runoff variations between treatments, sediment output was significantly lower from all surfaces covered by RECSs. The median cumulative sediment output from the bare surfaces was 6·9 kg, compared with 1·2 kg from the open‐weave RECSs and 0·2 kg from the random‐fibre RECSs. The random‐fibre systems were particularly effective under the more stressful overland flow application phase, with 63 times less sediment eroded than the bare treatments and 12 times less than that from the open‐weave systems. Architectural design differences between the two groups of RECSs are discussed in light of their relation to erosion process dynamics and shear stress partitioning. Copyright © 2006 John Wiley & Sons, Ltd.