bluuebunny/crossref_metadata_2025 huggingface dataset:
Pigmented eyes, photoreceptor‐like sense organs and central nervous system in the polychaete Scoloplos armiger (Orbiniidae, Annelida) and their phylogenetic importance
Authors: Wilkens Verena , Purschke Günter
Published: June 2009

The phylogenetic position of Orbiniidae within Annelida is unresolved. Conflicting hypotheses place them either in a basal taxon Scolecida, close to Spionida, or in a basal position in Aciculata. Because Aciculata have a specific type of eye, the photoreceptive organs in the orbiniid Scoloplos armiger were investigated to test these phylogenetic hypotheses. Two different types of prostomial photoreceptor‐like sense organs were found in juveniles and one additional in subadults. In juveniles there are four ciliary photoreceptor‐like phaosomes with unbranched cilia and two pigmented eyes. The paired pigmented eyes lie beside the brain above the circumoesophageal connectives. Each consists of one pigmented cell, one unpigmented supportive cell and three everse rhabdomeric sensory cells with vestigial cilia. During development the number of phaosomes increases considerably and numerous unpigmented sense organs appear consisting of one rhabdomeric photoreceptor cell and one supportive cell. The development and morphology of the pigmented eyes of S. armiger suggest that they represent miniaturized eyes of the phyllodocidan type of adult eye rather than persisting larval eyes resulting in small inverse eyes typical of Scolecida. Moreover, the structure of the brain indicates a loss of the palps. Hence, a closer relationship of Orbiniidae to Phyllodocida is indicated. Due to a still extensive lack of ultrastructural data among polychaetes this conclusion cannot be corroborated by considering the structure of the unpigmented ciliary and rhabdomeric photoreceptor‐like sense organs. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
The chemosensilla on tarsi of Locusta migratoria (Orthoptera: Acrididae): Distribution, ultrastructure, expression of chemosensory proteins
Authors: Zhou Shu‐Hui , Zhang Shan‐Gan , Zhang Long
Published: June 2009

The chemosensilla on the tarsi of Locusta migratoria were mapped using light microscopy, as well as scanning and transmission electron microscopy. Only chemosensilla chaetica were found on the tarsi. On the basis of their ultrastructure, these can be grouped into three main subtypes: short, long, and sunken sensilla chaetica. Short sensilla chaetica can be further divided into two groups containing 6 or 7 neurons. Long sensilla chaetica are mainly located on the lateral surface of the tarsi. Short sensilla chaetica were mainly found on the dorsal surface of the tarsi. Sunken sensilla chaetica were only found on the ventral surface, such as the pulvilli and arolium. Immunocytochemical localization of chemosensory protein (CSP) was performed on ultrathin sections of chemosensilla on tarsi. The antiserum against LmigCSP‐II intensively labeled all three types of sensilla chaetica. Gold granules were concentrated in the outer sensillum lymph surrounding the dendrite sheath, while the inner sensillum lymph containing dendrite branches was never labeled. Massive labeling with the anti‐LmigCSP‐II was also found in cuticle of the pulvilli on the ventral surface of tarsi. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
Skeletal development in the Chinese soft‐shelled turtlePelodiscus sinensis(Testudines: Trionychidae)
Authors: Sánchez‐Villagra Marcelo R. , Müller Hendrik , Sheil Christopher A. , Scheyer Torsten M. , Nagashima Hiroshi , Kuratani Shigeru
Published: June 2009

We investigated the development of the whole skeleton of the soft‐shelled turtlePelodiscus sinensis,with particular emphasis on the pattern and sequence of ossification. Ossification starts at late Tokita‐Kuratani stage (TK) 18 with the maxilla, followed by the dentary and prefrontal. The quadrate is the first endoskeletal ossification and appears at TK stage 22. All adult skull elements have started ossification by TK stage 25. Plastral bones are the first postcranial bones to ossify, whereas the nuchal is the first carapacial bone to ossify, appearing as two unstained anlagen. Extensive examination of ossification sequences among autopodial elements reveals much intraspecific variation. Patterns of ossification of cranial dermal elements are more variable than those of endochondral elements, and dermal elements ossify before endochondral ones. Differences in ossification sequences withApalone spiniferainclude: inPelodiscus sinensisthe jugal develops relatively early and before the frontal, whereas it appears later inA. spinifera;the frontal appears shortly before the parietal inA. spiniferawhereas inP. sinensisthe parietal appears several stages before the frontal. Chelydrids exhibit an early development of the postorbital bone and the palatal elements as compared to trionychids. Integration of the onset of ossification data into an analysis of the sequence of skeletal ossification in cryptodirans using the event‐pairing and Parsimov methods reveals heterochronies, some of which reflect the hypothesized phylogeny considered taxa. A functional interpretation of heterochronies is speculative. In the chondrocranium there is no contact between the nasal capsules and planum supraseptale via the sphenethmoid commissurae. The pattern of chondrification of forelimb and hind limb elements is consistent with a primary axis and digital arch. There is no evidence of anterior condensations distal to the radius and tibia. A pattern of quasi‐ simultaneity is seen in the chondrogenesis of the forelimb and the hind limb. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
Lipid raft‐targeted Akt promotes axonal branching and growth cone expansion via mTOR and Rac1, respectively
Authors: Grider M.H. , Park D. , Spencer D.M. , Shine H.D.
Published: June 2009

The molecular mechanisms by which extracellular guidance cues regulate axonal morphology are not fully understood. Recent findings suggest that increased activity of the protein kinase Akt promotes dendritic branching and elongation in hippocampal neurons. We tested whether expression of constitutively active Akt (CA‐Akt) in primary sensory neurons would promote axonal branching and whether targeting CA‐Akt to lipid rafts, common sites of Akt function, would differentially regulate axonal morphology. Biolistic transduction of sensory neurons induced a rapid expression of CA‐Akt, resulting in increased axonal branching, cell hypertrophy, and growth cone expansion. Additionally, we found that targeting of CA‐Akt to lipid rafts significantly potentiated growth cone expansion compared with expression of CA‐Akt throughout the neuron. Because lipid rafts are concentrated within the growth cone, this finding suggests that signaling of expansion is likely regulated locally. We found that CA‐Akt‐mediated growth cone expansion, but not axonal branching, was attenuated by coexpression of dominant‐negative Rac1. In contrast, blockade of mammalian target of rapamycin (mTOR) prevented axonal branching and hypertrophy in response to CA‐Akt, but not growth cone expansion. These data indicate that Akt activity can regulate growth cone expansion via localized Rac1 signaling and regulate axonal branching and soma size via activation of mTOR. © 2009 Wiley‐Liss, Inc.
Rapid use‐dependent down‐regulation of γ‐aminobutyric acid type A receptors in rat mesencephalic trigeminal neurons
Authors: Saito Mitsuru , Toyoda Hiroki , Sato Hajime , Ishii Hisayoshi , Kang Youngnam
Published: June 2009

Rundown is ubiquitously seen in response to repetitive activation of receptor or ion channels as a use‐dependent down‐regulation through various mechanisms. In contrast to AMPA receptors, γ‐aminobutyric acid type A receptor (GABAAR) are believed to display no rapid use‐dependent down‐regulation. We report here a rapid use‐dependent down‐regulation of GABAAR in primary sensory neurons of rat mesencephalic trigeminal nucleus (MTN), which express synaptic GABAARs in addition to extrasynaptic ones, unlike other primary sensory neurons. When muscimol was repetitively puff‐applied to an MTN neuron every 2 min before, during, and after the muscimol bath application for 5 min, both the GABAAresponses obtained under both current‐ and voltage‐clamp conditions were almost completely depressed during the bath application. However, the former and latter GABAAresponses recovered to 26% ± 7% and 36% ± 7% of their control amplitudes, respectively, 15 min after washout of the bath‐applied muscimol. By contrast, when examined in the presence of chelerythrine, a protein kinase C (PKC) inhibitor, together with a stringent chelation of intracellular Ca2+, the puff responses were almost completely recovered, whereas those were recovered to 40–60% of the control by either chelerythrine or EGTA alone. A phosphatidylinositol 3‐kinase inhibitor (PI3K), wortmannin, which blocks various signal transductions, including vesicular trafficking, significantly enhanced the rundown of the puff responses examined every 2 min. These findings indicate that the rundown of GABAAresponse in MTN neurons is mediated by the use‐dependent down‐regulation of GABAAR, which is reversed by PKC inhibition together with intracellular Ca2+chelation, while being facilitated by PI3K inhibition. © 2009 Wiley‐Liss, Inc.
Viability and differentiation of neural precursors on hyaluronic acid hydrogel scaffold
Authors: Pan Linjie , Ren Yongjuan , Cui Fuzhai , Xu Qunyuan
Published: June 2009

The traditional notion that injured neurons are unable to regenerate in the adult mammalian brain and spinal cord has long been a concern. This view has led to methodology designed to overcome this problem, most recently by advancements in tissue engineering. Here, neural precursor cells (NPCs) and the Nogo receptor antibody (NgR‐Ab) or poly‐L‐lysine (PLL) were tested in concert with hyaluronic acid hydrogel scaffolds (HA). In particular, we wished to optimize viability and differentiation of NPCs within HA hydrogel scaffolds. Our results show that HA hydrogels can be modified physically or chemically to improve NPCs attachment on the scaffolding doped with NgR‐Ab or PLL. Both the HA hydrogels and their modifications support the viability of NPCs. NPCs were also able to differentiate into neurons and glial cells on HA hydrogels, although this was affected by the different modifications. Immunofluorescence showed that fewer β‐III‐tubulin antibody and antineurofilament antibody‐positive cells were found on HA‐PLL hydrogel compared with HA or HA NgR‐Ab hydrogels. This indicates that the PLL‐modified HA hydrogels may inhibit differentiation of NPCs, whereas modification by NgR‐Ab had no such effect. Finally, the NgR‐Ab‐modified HA scaffold can be used as not only a NPC delivery system but also a bioactive factor transportation system for CNS repair. © 2009 Wiley‐Liss, Inc.
C‐terminal region‐dependent change of antibody‐binding to the Eighth Reelin repeat reflects the signaling activity of Reelin
Authors: Kohno Takao , Nakano Yoshimi , Kitoh Noriko , Yagi Hirokazu , Kato Koichi , Baba Atsushi , Hattori Mitsuharu
Published: June 2009

Reelin is a secreted glycoprotein that plays pivotal roles in the development and function of the brain, but how it activates downstream intracellular signaling is not fully understood. We have recently reported that the highly conserved C‐terminal region (CTR) of Reelin is required for its full signaling activity, although the underlying mechanism remains unknown. During biochemical study of Reelin, we serendipitously found that one commercially available anti‐Reelin antibody G20 can bind to CTR‐lacking mutant Reelin proteins, but not wild‐type Reelin, on Western blotting. The G20 epitope resides in the last 19 residues of Reelin‐repeat 8 (RR8), and neither posttranslational modification nor proteolysis can explain this effect. Furthermore, when an unrelated sequence, such as FLAG‐tag, is inserted between RR8 and CTR, the reactivity of the corresponding antibody greatly decreases. These results suggest that RR8 and CTR form a tight structure that makes the surrounding sequence inaccessible to an antibody. Taking advantage of this phenomenon, we show the existence of CTR‐lacking Reelin isoform in vivo for the first time and estimate its contribution to the total amount of secreted Reelin. Importantly, the extent to which Reelin mutants react with G20 is inversely correlated with their signaling activity, indicating that the CTR‐induced structural change of RR8 is a prerequisite for downstream signaling activation, presumably via binding to a certain neuronal membrane molecule(s). © 2009 Wiley‐Liss, Inc.
Localization of zip1 and zip4 mRNA in the adult rat brain
Authors: Belloni‐Olivi Luisa , Marshall Cathleen , Laal Bachchu , Andrews Glenn K. , Bressler Joseph
Published: June 2009

The localization of two members of the Slc39a (zip1 and zip4) family of zinc transporters was examined in the brains of adult mice. Zip1 was highly enriched in brain regions with high densities of neuronal cell bodies, including the hippocampus, thalamus, and perifontal cortex. Zip1 was also expressed in commissural fiber tracts such as the corpus callosum and anterior commissure, but little was found in the internal and external capsules. Also, very low amounts of zip1 mRNA were detected in resting astrocytes and reactive astrocytes that were examined at 14 days after inflicting a stab wound. Zip1 mRNA was detected in ependymal cells lining the third and lateral ventricles and epithelium cells in the choroid plexus. Interestingly, zip4 mRNA was detected in the choroid plexus but not in the ependymal cells or other neural elements. Zip4 mRNA was also detected in brain capillaries, but zip1 mRNA was not. In zip4 knockout heterozygotes that express green fluorescent protein regulated by the zip4 promoter, green fluorescent protein was detected in brain capillaries. Because zip4 levels are regulated by dietary Zn, our studies suggest that the brain has the potential of adapting to changes in Zn status. © 2009 Wiley‐Liss, Inc.
The small heat shock protein Hsp27 protects cortical neurons against the toxic effects of β‐amyloid peptide
Authors: King Michael , Nafar Firoozeh , Clarke Joseph , Mearow Karen
Published: June 2009

Neurofibrillary tangles and amyloid plaques are considered to be hallmarks of Alzheimer's disease (AD), and the toxic effects of amyloid‐β peptide (Aβ) lead to activation of stress‐related signaling and neuronal loss. The small heat shock protein Hsp27 is reported to be increased in AD brains and to accumulate in plaques, but whether this represents a potentially protective response to stress or is part of the disease process is not known. We hypothesized that increased expression of Hsp27 in neurons can promote neuronal survival and stabilize the cytoskeleton in the face of Aβ exposure. By using neonatal rat cortical neurons, we investigated the potential role of Hsp27 in neuronal cultures in the presence or absence of Aβ. We initially tested whether a heat stress (HS) would be sufficient to induce endogenous Hsp27 expression. HS not only did not result in neuronal Hsp27 up‐regulation but made the cells more vulnerable to Aβ exposure. We then used cDNA transfection to overexpress EGFP‐Hsp27 (or the empty vector) in cultures and then assessed neuronal survival and growth. Transfected neurons appeared healthy and had robust neuritic outgrowth. Aβ treatment induced significant cell death by 48–72 hr in nontransfected and empty‐vector‐expressing cultures. In contrast, cultures expressing Hsp27 did not display significant apoptosis. Our results show that Hsp27‐expressing neurons were selectively protected against the deleterious effects of Aβ treatment; neuronal degeneration was prevented, and Aβ‐induced alterations in mitochondrial size were attenuated. We also demonstrate that Hsp27 expression can enhance neurite growth in cortical neurons compared with control vector‐transfected cells. Overall, our study provides new evidence that Hsp27 can provide a protective influence in primary cortical neurons in the face of toxic concentrations of amyloid. © 2009 Wiley‐Liss, Inc.
Novel axonal distribution of neurofilament‐H phosphorylated at the glycogen synthase kinase 3β‐phosphorylation site in its E‐segment
Authors: Sasaki Takahiro , Ishiguro Koichi , Hisanaga Shin‐ichi
Published: June 2009

The Ser493 residue in the E‐segment of the rat neurofilament heavy chain (NF‐H) is phosphorylated by glycogen synthase kinase 3β (GSK3β) in vitro and in spinal cord. We examined Ser493 phosphorylation by analyzing developmental changes and cellular distribution of phospho‐Ser493 using phosphorylation‐site‐specific antibodies. This residue was phosphorylated in NF‐H prepared from human, rat, and mouse spinal cord, all species in which the amino acid sequence of NF‐H is known. Phosphorylated Ser493 appeared on postnatal day 2 in rat brain, at the same time when NF‐H is first detected. It gradually increased together with the increase in total NF‐H during brain development. Phospho‐Ser493 was detected on the phosphorylated form of NF‐H at multiple Lys‐Ser‐Pro (KSP) repeats, which are distributed mainly in axons. In rat ventral horn, phosphorylated Ser493 was localized in axons but not in cell bodies or dendrites. However, the distributions of phosphorylated Ser493 and KSP phosphorylation in axons were not identical. Ser493 was continuously phosphorylated at nodes of Ranvier, whereas the KSP sites were dephosphorylated. Ser493 was also phosphorylated in unmyelinated regions of optic nerve axons. A biochemical difference in phosphorylation between Ser493 and KSP repeats was also found; the subtle phosphorylation at Ser493 was detected in NF‐H unphosphorylated at the KSP repeats by immunoblotting cerebral cortex extracts. These results indicate that Ser493 in the NF‐H E‐segment is a novel site that is phosphorylated in both the myelinated and the unmyelinated regions of axons. © 2009 Wiley‐Liss, Inc.
Adult cerebrospinal fluid inhibits neurogenesis but facilitates gliogenesis from fetal rat neural stem cells
Authors: Buddensiek Judith , Dressel Alexander , Kowalski Michael , Storch Alexander , Sabolek Michael
Published: June 2009

Neural stem cells (NSCs) are a promising source for cell replacement therapies for neurological diseases. Administration of NSCs into the cerebrospinal fluid (CSF) offers a nontraumatic transplantation method into the brain. However, cell survival and intraparenchymal migration of the transplants are limited. Furthermore, CSF was recently reported to be an important milieu for controlling stem cell processes in the brain. We studied the effects of adult human leptomeningeal CSF on the behavior of fetal rat NSCs. CSF increased survival of NSCs compared with standard culture media during stem cell maintenance and differentiation. The presence of CSF enhanced NSC differentiation, leading to a faster loss of self‐renewal capacity and faster and stronger neurite outgrowth. Some of these effects (mainly cell survival, neurite brancing) were blocked by addition of the bone morphogenic protein (BMP) inhibitor noggin. After differentiation in CSF, significantly fewer MAP2ab+ neurons were found, but there were more GFAP+ astroglia compared with standard media. By RT‐PCR analysis, we determined a decrease of mRNA of the NSC marker gene Nestin but an increase of Gfap mRNA during differentiation up to 72 hr in CSF compared with standard media. Our data demonstrate that adult human leptomeningeal CSF enhances cell survival of fetal rat NSCs during proliferation and differentiation. Furthermore, CSF provides a stimulus for gliogenesis but inhibits neurogenesis from fetal NSCs. Our data suggest that CSF contains factors such as BMPs regulating NSC behavior, and we hypothesize that fast differentiation of NSCs in CSF leads to a rapid loss of migration capacity of intrathecally transplanted NSCs. © 2009 Wiley‐Liss, Inc.
Technologic innovations in surgery: A philosophic reflection on their impact on operations for cancer
Authors: Lawrence Walter
Published: June 2009

Technologic advances this past half‐century have clearly had a positive effect on our ability to both diagnose and treat human cancer as well as on the operative treatment of other diseases. However, the impact of these innovations on the surgical treatment of cancer is not as clear as it is for many other problems that are managed surgically. This review is an “opinion piece” that attempts to assess the successes and failures of technologic innovations that have been introduced for the purpose of improving the operative treatment of cancer. J. Surg. Oncol. 2009;100:163–168. © 2009 Wiley‐Liss, Inc.
Development of Gelatin Hydrogel Pads as Antibacterial Wound Dressings
Authors: Rattanaruengsrikul Vichayarat , Pimpha Nuttaporn , Supaphol Pitt
Published: June 2009

Gelatin hydrogel pads have been prepared from a 10 wt.‐% gelatin solution that contained 2.5 wt.‐% AgNO3 in 70% v/v acetic acid by a solvent‐casting technique. The AgNO3‐containing gelatin solution was aged under mechanical stirring for various time intervals to allow for the formation of silver nanoparticles (nAgs). The formation of nAgs was monitored by a UV‐vis spectrophotometer. The morphology and size of the nAgs were characterized by transmission electron microscopy (TEM). To improve the water resistance of the hydrogels, various contents of glutaraldehyde (GTA) were added to the AgNO3‐containing gelatin solution to cross‐link the obtained gelatin hydrogels. These hydrogels were tested for their water retention and weight loss behavior, release characteristics of the as‐loaded silver, and antibacterial activity against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus. The AgNO3‐containing gelatin solution that had been aged for 5 d showed the greatest number of nAgs formed. The size of these particles, based on TEM results, was 10–11 nm. With an increase in the GTA content used to cross‐link the hydrogels, the water retention, the weight loss, and the cumulative amount of silver released were found to decrease. Finally, all of the nAg‐loaded gelatin hydrogels could inhibit the growth of the tested pathogens, which confirmed their applicability as antibacterial wound dressings.

magnified image
Synthesis of Comb Tri‐ and Tetrablock Copolymers Catalyzed by the Grubbs First Generation Catalyst
Authors: Runge M. Brett , Yoo Jun , Bowden Ned B.
Published: June 2009

High molecular weight tri‐ and tetrablock copolymers were synthesized from the commercially available Grubbs first generation catalyst for the first time. These polymers had degrees of polymerization from 430 to 1 100, molecular weights up to 419 000 g · mol−1, and narrow polydispersities. Oxanorbornene monomers were chosen due to their fast rates of polymerization and slow rates of cross metathesis. Polystyrene arms were grown from selected blocks by atom transfer radical polymerization to yield architecturally complex comb tri‐ and tetrablock copolymers. These polymers self‐assembled in the solid state into ordered morphologies that were characterized by scanning electron microscopy.

magnified image
Design of Soluble Hyperbranched Polythiophenes with Tailor‐Made Optoelectronic Properties
Authors: Richter Thomas V. , Link Steffen , Hanselmann Ralf , Ludwigs Sabine
Published: June 2009

Hyperbranched polythiophenes were prepared via a simple one‐pot synthesis approach based on oxidative coupling of branched conjugated monomers. Only small variations in the building unit and architecture lead to large differences of absorption and photoluminescence properties. Interestingly, soluble hyperbranched polythiophenes with relatively small molecular weights show enhanced absorption at low and high wavelengths compared to linear analogues, such as poly(3‐hexyl thiophenes) with high molecular weights. With this versatile approach we present a method to design tailor made, functional materials with potential applications in optoelectronics.

magnified image
Coordination‐Polymeric Nanofibers and their Field‐Emission Properties
Authors: Batabyal Sudip K. , Peedikakkal Abdul Malik Puthan , Ramakrishna Seeram , Sow Chorng Haur , Vittal Jagadese J.
Published: June 2009

The large‐scale fabrication of nanofibers of coordination polymers (CPs) is reported for the first time from CP gel precursors by the electrospinning method. In the absence of organic polymeric additives, viscous solutions suitable for drawing fibers have been made by diluting the gel precursors, which are obtained by mixing Ni(OAc)2 and 4‐trifluoromethylbenzoic acid with 4,4′‐bis(pyridyl)ethylene (bpe) or 4,4′‐bipyridine (bpy) linear spacer ligands in organic solvents. One‐dimensional polymeric structures have been proposed for these gels and nanofibers based on the crystal structures of the compounds isolated. These fibers show some interesting field‐emission properties. The results described here may well be extended to other one‐dimensional polymers, thus opening the door for processing of the coordination polymers.

magnified image
Self‐Assembly of Nano Hydroxyapatite or Aragonite Induced by Molecular Recognition to Soy Globulin 7S or 11S
Authors: Liu Dagang , Tian Huafeng , Kumar Rakesh , Zhang Lina
Published: June 2009

Molecular self‐assembly is emerging as a viable ‘bottom‐up’ approach to build stable organic/inorganic nanometer‐scale blocks. Herein, under the conditions of appropriate pH and ionic strength, soy globulin 7S or 11S were coprecipitated with hydroxyapatite (HAp) or aragonite (Arag), respectively, to fabricate two organic/inorganic hybrids: 7S/HAp and 11S/Arag. Results from high‐resolution transmission electron microscopy show that the hybrids exhibit a nanosized core–shell structure with globulin monomer 7S or 11S as core and HAp or Arag as shells. 7S/HAp and 11S/Arag present a disk and hexagon shape, respectively. After calcinations, monodispersed HAp without support from globulins existed as nanospheres. It was revealed that the globulin as host induces the self‐assembly and growth layer by layer of HAp or Arag nanocrystals. The factors of molecular recognition and surface potential definitely affected the size and shape of the hierarchical blocks. This work provided a novel pathway to controllably synthesize a wide variety of precise plant protein/biomineral hybrid biomaterials.

magnified image
Molecular Recognition in Solutions of Rod‐Like Copolymers with Two Different Sequences
Authors: Lazutin Alexei A. , Berezkin Anatoly V.
Published: June 2009

Segregation in a solution of rigid copolymeric molecules with two different sequences leading to co‐existence of two smectic mesophases has been studied. Thermodynamic characteristics of these mesophases and their equilibrium compositions were found in the frame of two discrete models. It was shown that the degree of ordering in the mesophase depends on the sequence of units in the identical molecules forming this mesophase. The concentration of “mismatched” molecules in the mesophase (the purity of mesophase) is determined both by the composition and the sequence of such molecules. It was shown, that a difference in the sequences can be sufficient to cause phase separation.

magnified image
Structures of Polyaniline Bases: Semi‐Empirical Computations
Authors: Lee Ki‐Ho , Song Dong Hyun , Park Bong Jun , Chin In‐Joo , Choi Hyoung Jin
Published: June 2009

Both MM3 and semi‐empirical electronic structure calculations were performed for studying different conformations of PANI oligomers. The results were compared with experimental findings and analyzed to predict the relationship among individual conformations of single PANI chains, structures of packed PANI bases, and their electrical properties. Various combinations of initially optimized PANI octamers were studied. It is predicted that the total energies of the packed PANI bases depend mostly on the packing mode while their MO levels depend on the conformations of the individual PANI chains. The changes in the MO levels were found to take place due to the intermolecular interactions of the chains.

magnified image
Impulsive and compulsive behaviors in Parkinson's disease
Authors: Evans Andrew H. , Strafella Antonio P. , Weintraub Daniel , Stacy Mark
Published: June 2009

Antiparkinson therapy can be the primary cause of a range of nonmotor symptoms that include a set of complex disinhibitory psychomotor pathologies and are linked by their repetitive, reward or incentive‐based natures. These behaviors relate to aberrant or excessive dopamine receptor stimulation and encompass impulse control disorders (ICDs), punding, and the dopamine dysregulation syndrome (DDS). Common ICDs include pathological gambling, hypersexuality, compulsive eating, and compulsive buying. This review focuses on the phenomenology, epidemiology, and methods to identify and rate these disorders. The management of dopaminergic drug‐related compulsive behaviors is discussed in the light of the current understanding of the neurobiological substrate of these disorders. © 2009 Movement Disorder Society
Torpedoes in Parkinson's disease, Alzheimer's disease, essential tremor, and control brains
Authors: Louis Elan D. , Faust Phyllis L. , Vonsattel Jean‐Paul G. , Honig Lawrence S. , Rajput Alex , Rajput Ali , Pahwa Rajesh , Lyons Kelly E. , Ross Webster G. , Elble Rodger J. , Erickson‐Davis Cordelia , Moskowitz Carol B. , Lawton Arlene
Published: June 2009

Purkinje cell axonal swellings (“torpedoes”), described in several cerebellar disorders as well as essential tremor (ET), have not been quantified in common neurodegenerative conditions. The aim of this study was to quantify torpedoes Parkinson's disease (PD) and Alzheimer's disease (AD) compared with ET and control brains. Brains included 40 ET cases (34 cerebellar ET, 6 Lewy body variant of ET) and age‐matched comparison brains (21 AD, 14 PD/diffuse Lewy body disease, 25 controls). Torpedoes were counted in 20 × 25 mm cerebellar cortical sections stained with Luxol Fast Blue/Hematoxylin and Eosin. The median number of torpedoes in cerebellar ET (12) was 12× higher than that of controls (1) and nearly 2.5× higher than in AD (5) or PD/DLBD (5) (all P ≤ 0.005). Furthermore, in a logistic regression model that adjusted for age and Alzheimer's‐type changes, each torpedo more than doubled the odds of having cerebellar ET (Odds ratiocerebellar ET vs. control = 2.57, P = 0.006), indicating that the association between increased torpedoes and cerebellar ET was independent of these Alzheimer's‐type changes. Although torpedoes are increased in AD and PD, as well as cerebellar ET, the magnitude of increase in cerebellar ET is greater, and cannot be accounted for by concomitant AD or PD pathology. © 2009 Movement Disorder Society
Older onset essential tremor: More rapid progression and more degenerative pathology
Authors: Louis Elan D. , Faust Phyllis L. , Vonsattel Jean‐Paul G. , Honig Lawrence S. , Henchcliffe Claire , Pahwa Rajesh , Lyons Kelly E. , Rios Eileen , Erickson‐Davis Cordelia , Moskowitz Carol B. , Lawton Arlene
Published: June 2009

There are few data on rate of progression in essential tremor (ET). To quantify the rate of tremor progression in a cross‐sectional sample of 348 ET cases in an epidemiological study; characterize the relationship between age of tremor onset and rate of tremor progression in that sample; and characterize the relationship between age of tremor onset, rate of tremor progression, and severity of underlying brain changes in 9 cases from a brain repository. Rate of tremor progression was defined as tremor severity ÷ duration. The degeneration index = number of torpedoes per section ÷ Purkinje cell linear density. In the epidemiological study, older age of tremor onset was associated with faster rate of tremor progression (P < 0.001). In the brain repository, older age of tremor onset was associated with higher degeneration index (P = 0.037), and higher degeneration index was associated with faster rate of tremor progression (P = 0.018). In a large clinical sample, older age of onset was associated with more rapid tremor progression. In a brain bank, older age of onset was associated with more degenerative pathology in the cerebellum. As in several neurodegenerative disorders, in older onset cases, it is possible that the disease advances more rapidly. © 2009 Movement Disorder Society
Bell's palsy preceding Parkinson's disease: A case‐control study
Authors: Savica Rodolfo , Bower James H. , Maraganore Demetrius M. , Grossardt Brandon R. , Rocca Walter A.
Published: June 2009

We investigated the association of Bell's palsy (BP) with the subsequent risk of Parkinson's disease (PD) using a case‐control study design. We matched 196 incident cases of PD in Olmsted County, MN, to 196 general population controls with same age (±1 year) and sex, and we reviewed the complete medical records of cases and controls in a medical records‐linkage system to detect BP. Six of the 196 patients with PD and none of the 196 controls were diagnosed with BP before PD (exact binomial probability, P = 0.02). The median age at occurrence of BP was 49.5 years (range, 15–84 years) and the median time between BP and the onset of PD was 27.5 years (range, 2–54 years). The findings were similar using a standardized incidence ratio (SIR) approach, but were not statistically significant. This initial association between BP and PD awaits replication. © 2009 Movement Disorder Society
Statins can modulate effectiveness of antitumor therapeutic modalities
Authors: Jakobisiak Marek , Golab Jakub
Published: June 2009

Despite significant, frequently very strong, antiproliferative and tumoricidal effects of statins demonstrated in vitro, their antitumor effects in animal models are modest, and their efficacy in clinical trials has not been proven. As such, statins seem unlikely to be ever regarded as antitumor agents. However, statins are regularly taken by many elderly cancer patients for the prevention of cardiovascular events. Owing to their pleiotropic effects in normal and tumor cells, statins interact in various ways with many antitumor treatment modalities, either potentiating or diminishing their effectiveness. Elucidation of these interactions might affect the choice of treatment to be planned in cancer patients as some combinations might be contraindicated, whereas others might elicit potentiated antitumor effects but at a cost of increased general toxicity. Some other combinations might induce either comparable or even stronger antitumor effects, but with a beneficial concomitant reduction of specific side effects. Most of the studies reviewed in this article have been carried in vitro or in experimental tumor models, but clinical relevance of the findings is also discussed. © 2009 Wiley Periodicals, Inc. Med Res Rev, 30, No. 1, 102–135, 2010
Revascularization of the lunate by a volar vascularized bone graft and an osteotomy of the radius in treatment of the Kienböck's disease
Authors: Mathoulin Christophe , Wahegaonkar Abhijeet L.
Published: June 2009

Kienböck, a German radiologist, described avascular necrosis of the lunate (Kienböck's disease) in 1910. The epidemiology and etiology are not well‐known and always has been debated. A negative ulnar variance is considered as a predisposing factor for Kienböck's disease by the majority of the authors. The treatment depends upon the stage of the disease at the time of presentation and diagnosis. Radial shortening and lengthening of the ulna are biomechanically satisfactory procedures because they increase the load sharing of the ulna and result in decompression of the lunate. Revascularization of the lunate by shortening of the radius may appear to be a very bold and ambitious technique. In very advanced cases, palliative procedures like wrist denervation, resection of the proximal carpal row, or wrist arthrodesis are the techniques resorted to. We report our experience of a series of 22 operated cases between 1994 and 2000 with a minimum follow up of 5 years. All cases were treated with an anterior vascularized bone graft based on the volar carpal artery associated to an osteotomy of the radius. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Vascularized bone graft from the supracondylar region of the femur
Authors: Doi Kazuteru , Hattori Yasunori
Published: June 2009

Free vascularized thin corticoperiosteal grafts and small periosteal bone grafts harvested from the supracondylar region of the femur are described. These grafts are nourished from the articular branch of the descending genicular artery and vein. Unlike currently used vascularized bone grafts, this graft can be successfully harvested with disturbing the vascularity. Thin corticoperiosteal grafts consist of periosteum with a thin layer of outer cortical bone and include the cambium layer, which has a better osteogenic capacity. This graft is elastic and readily conforms to the recipient bed configuration. Thin corticoperiosteal grafts were used for fracture nonunion of the long bone with smaller bone defect and to treat forty‐six patients with avascular necrosis of the body of the talus, scaphoid, and lunate bone. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Head and neck reconstruction using cephalic vein transposition in the vessel‐depleted neck
Authors: Vasilakis Vasileios , Patel Hasu D. L. , Chen Hung‐Chi
Published: June 2009

In microvascular reconstructive surgery the patency of the recipient vessels is the key to successful outcome. In head and neck surgery there is often a lack of adequate recipient vessels as a result of chemoradiation therapy and ablative surgery. To overcome this it is crucial to identify vessels of adequate length and diameter outside the field of injury. We report our experience with cephalic vein transposition for drainage of seven free flaps—six intestinal and one osteocutaneous—for head and neck reconstruction. In five cases the cephalic vein was used during the free flap transfer and in two cases in salvage re‐exploration surgery. All flaps survived completely. The anatomical course and location of the cephalic vein allow good patency and straightforward harvesting. Its vascular properties are predictive of reduced incidence of complications such as flap congestion and failure. We suggest that the cephalic vein offers a high venous flow drainage system for large free flaps and advocate its use in free intestinal transfer in the vessel‐depleted neck as well as in re‐exploration surgery. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Kernel estimation of quantile sensitivities
Authors: Liu Guangwu , Hong Liu Jeff
Published: June 2009

Quantiles, also known as value‐at‐risks in the financial industry, are important measures of random performances. Quantile sensitivities provide information on how changes in input parameters affect output quantiles. They are very useful in risk management. In this article, we study the estimation of quantile sensitivities using stochastic simulation. We propose a kernel estimator and prove that it is consistent and asymptotically normally distributed for outputs from both terminating and steady‐state simulations. The theoretical analysis and numerical experiments both show that the kernel estimator is more efficient than the batching estimator of Hong9. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
On a Markov‐modulated shock and wear process
Authors: Kharoufeh Jeffrey P. , Mixon Dustin G.
Published: June 2009

We present transient and asymptotic reliability indices for a single‐unit system that is subject to Markov‐modulated shocks and wear. The transient results are derived from the (transform) solution of an integro‐differential equation describing the joint distribution of the cumulative degradation process and the state of the modulating process. Additionally, we prove the asymptotic normality of a properly centered and time‐scaled version of the cumulative degradation at time t. This asymptotic result leads to a simple normal approximation for a properly centered and space‐scaled version of the systes lifetime distribution. Two numerical examples illustrate the quality of the normal approximation. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
An enriched cohesive zone model for delamination in brittle interfaces
Authors: Samimi M. , van Dommelen J. A. W. , Geers M. G. D.
Published: June 2009

Application of standard cohesive zone models in a finite element framework to simulate delamination in brittle interfaces may trigger non‐smooth load–displacement responses that lead to the failure of iterative solution procedures. This non‐smoothness is an artifact of the discretization; and hence it can be avoided by sufficiently refining the mesh leading to unacceptably high computational costs and a low efficiency and robustness. In this paper, a process‐driven hierarchical extension is proposed to enrich the separation approximation in the process zone of a cohesive crack. Some numerical examples show that instead of mesh refinement, a more efficient enriched formulation can be used to prevent a non‐smooth solution. Copyright © 2009 John Wiley & Sons, Ltd.
Two‐level multiscale enrichment methodology for modeling of heterogeneous plates
Authors: Oskay Caglar
Published: June 2009

A new two‐level multiscale enrichment methodology for analysis of heterogeneous plates is presented. The enrichments are applied in the displacement and strain levels: the displacement field of a Reissner–Mindlin plate is enriched using the multiscale enrichment functions based on the partition of unity principle; the strain field is enriched using the mathematical homogenization theory. The proposed methodology is implemented for linear and failure analysis of brittle heterogeneous plates. The eigendeformation‐based model reduction approach is employed to efficiently evaluate the non‐linear processes in case of failure. The capabilities of the proposed methodology are verified against direct three‐dimensional finite element models with full resolution of the microstructure. Copyright © 2009 John Wiley & Sons, Ltd.
Polymeric piezoelectric cantilever and tubular actuators
Authors: Ni S. S. , Li T. , Ma J.
Published: June 2009

Electroactive polymers (EAPs) have attracted a great deal of attention in the last decade due to their unique properties that are applicable to many advanced applications. The present work aims to study the materials–property relationship of this class of materials, and thus facilitate the implementation of EAPs in more applications. The present work investigated the feasibility of adapting cantilever and tubular configurations to the polymeric piezoelectric actuators. The polarization and displacement of samples (fabricated from Poly(Vinyldene fluoride‐trifluroethylene) [P(VDF‐TrFE)] thin film) were measured under both dynamic and static driving conditions. The polarization loops for all the samples exhibit little hysteresis under weak field and the polarization changes linearly with voltage for most samples. The frequency‐dependent polarization behavior is consistent with the previous reported work. The displacements for both cantilever and tubular samples are also noted to be in agreement with the theoretical prediction. Significant displacement (1079 µm) was achieved for samples, even under weak field (60 MV/m). In summary, the results have suggested that the relationship between geometric variables and the performance is also applicable to polymeric materials. Thus, the constitutive relationship can also be applied as a guideline for designing and optimizing the polymeric actuators beyond P(VDF‐TrFE) copolymer materials. Copyright © 2009 John Wiley & Sons, Ltd.
The incidence of diabetes in atypical antipsychotic users differs according to agent—results from a multisite epidemiologic study
Authors: Yood Marianne Ulcickas , deLorenze Gerald , Quesenberry Charles P. , Oliveria Susan A. , Tsai Ai‐Lin , Willey Vincent J. , McQuade Robert , Newcomer John , L'Italien Gilbert
Published: June 2009

Purpose

The purpose of this study was to examine the association between atypical antipsychotics, including the newer agents, aripiprazole and ziprasidone, and newly treated diabetes, using the largest post‐marketing cohort of patients exposed to these newer treatments that has been studied to date.

Methods

Identified two overlapping cohorts—a simple cohort (all antipsychotic users) and an inception cohort (new users of antipsychotics)—using automated data from three United States sites (60.4 million covered lives). Patients exposed to antipsychotics ≥ 45 days were identified and followed for incident diagnoses of treated diabetes. Data analysis accounted for drug switching and non‐consistent drug use.

Results

In the 55 287‐member inception cohort, 357 cases of newly treated diabetes were identified. Compared with current use of typical antipsychotics, current users of aripiprazole (adjusted hazard ratio (aHR) 0.93, 95% confidence interval (CI) 0.50–1.76), quetiapine (aHR 1.04, 95%CI, 0.67–1.62), risperidone (aHR 0.85, 95%CI, 0.54–1.36) and ziprasidone (aHR 1.05, 95%CI, 0.54–2.08) had similar low risk of diabetes. Patients exposed to olanzapine had an increased risk of diabetes (aHR 1.71, 95%CI, 1.12–2.61), and although the effect estimate is imprecise, clozapine‐exposed patients had a trend towards an elevated hazard ratio (aHR 2.58, 95%CI, 0.76–8.80). Results for the simple cohort were similar.

Conclusions

Relative to typical antipsychotics, aripiprazole, ziprasidone, risperidone and quetiapine were not associated with an increased risk of diabetes; olanzapine and clozapine were associated with an increased risk. This analysis constitutes the largest post‐marketing pharmacoepidemiologic study to date that includes the newer agents. Copyright © 2009 John Wiley & Sons, Ltd.
Heart rate variability predicts self‐control in goal pursuit
Authors: Geisler Fay C. M. , Kubiak Thomas
Published: June 2009

The aim of our study was to investigate the effects of a failure experience on the exercise of self‐control in goal pursuit. We hypothesized that tonic heart rate variability (tonic HRV), a possible physiological marker of inhibitory capacity, increases the exercise of self‐control in the pre‐ and post‐actional phase in goal pursuit after failure. Participants received feedback for an alleged intelligence test and subsequently worked on the same test again. As indicators of exercised self‐control, we assessed self‐confidence in the pre‐actional phase and rumination in the post‐actional phase. As hypothesized, tonic HRV was positively associated with pre‐ and post‐actional self‐control, even after controlling for the effect of neuroticism. We discuss the implications of our results for the self‐regulatory strength model. Copyright © 2009 John Wiley & Sons, Ltd.
The relationship of GMA to counterproductive work behavior revisited
Authors: Marcus Bernd , Wagner Uwe , Poole Amanda , Powell Deborah M. , Carswell Julie
Published: June 2009

Recent research reported that general mental ability (GMA) predicted counterproductive work behavior (CWB), whereas some previous studies failed to find such a relationship. We tested occupational homogeneity of the sample and criterion measurement as two potential explanations for these inconsistencies. Study 1 replicated major design features of one previous study, which found no GMA–CWB relation in a heterogeneous sample, with occupationally homogeneous groups. Results confirmed previous null findings, indicating no effect of sample homogeneity. In Study 2, using a controlled laboratory setting, GMA was again unrelated to self‐reported CWB, but partially predicted observed CWB negatively. Combined findings suggest that GMA is consistently unrelated to CWB self‐reports but may predict objectively measured CWB independently of the likelihood of being caught. Copyright © 2009 John Wiley & Sons, Ltd.