bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Macrocyclic Molecular Rods as Potential Electronic Devices
Authors: Błaszczyk Alfred , Chadim Martin , von Hänisch Carsten , Mayor Marcel
Published: July 2006

The design and synthesis of the macrocycles 1 and 2 as model compounds for the investigation of negative differential conductance phenomena in molecular junctions are reported. The macrocycles 1 and 2 comprise a molecular rod subunit consisting of three ethynyl‐linked phenyl rings. While the rotational freedom along the rod axis of both terminal phenyl rings is limited by the macrocyclic frame, the central phenyl ring is revolving. The rod substructure is terminally functionalized with acetyl‐protected thiol groups to enable its immobilization between gold contacts. The central phenyl ring is functionalized with one and two nitro groups for 1 and 2, respectively. The nitro groups are of particular importance as i) both macrocycles are model compounds to investigate a hypothetical intramolecular interaction of the nitro group with the opposite macrocyclic subunits and ii) the nitro group(s) result in limited thermal stability of the compounds due to the intramolecular rearrangement to macrocycles comprising isatogen subunits. These highly functionalized macrocycles have been assembled by acetylene scaffolding strategies in combination with functional group transformation chemistry.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Enhanced separation of purine and pyrimidine bases using carboxylic multiwalled carbon nanotubes as additive in capillary zone electrophoresis
Authors: Xiong Xin , Ouyang Jin , Baeyens Willy R. G. , Delanghe Joris R. , Shen Xiumin , Yang Yiping
Published: July 2006

This paper describes the enhanced separation of adenine (A), hypoxanthine (HX), 8‐azaadenine (8‐AA), thymine (T), cytosine (C), uracil (U) and guanine (G) by CZE dispersing carboxylic multiwalled carbon nanotubes (c‐MWNTs) into the running buffer. The effect of important factors such as c‐MWNT nanoparticle concentration, the acidity and concentration of running buffer, and separation voltage were investigated to acquire the optimum conditions. The seven purine and pyrimidine bases could be well separated within 16 min in a 35 cm effective length fused‐silica capillary at a separation voltage of +8.0 kV in a 23 mM tetraborate buffer (pH 9.2) containing 8.0×10−5 g/mL c‐MWNTs. Under the optimal conditions, the linear ranges were of 2–250 μg/mL for A (R2 = 0.995), 3–200 μg/mL for U (R2 = 0.990) and G (R2 = 0.992), 3–250 μg/mL for T (R2 = 0.998), 2–200 μg/mL for C (R2 = 0.985) and 4–200 μg/mL for HX (R2 = 0.988) and 8‐AA (R2 = 0.990). The detection limits were 0.9 μg/mL for A (S/N = 3), 2.4 μg/mL for U, 2.0 μg/mL for T, 1.5 μg/mL for C, 2.5 μg/mL for G and 3.0 μg/mL for HX and 8‐AA. The proposed method was successfully applied for determining five purine and pyrimidine bases in yeast RNA.
Differential activation of microglia in neurogenic versus non‐neurogenic regions of the forebrain
Authors: Goings Gwendolyn E. , Kozlowski Dorothy A. , Szele Francis G.
Published: July 2006

Proliferation decreases in the neurogenic subventricular zone (SVZ) of mice after aspiration lesions of the cerebral cortex. We hypothesized that microglial activation may contribute to this given microglial activation attenuates neurogenesis in the hippocampus. Using CD45, CD11b, IB4, and IL‐6 immunohistochemistry (IHC), BrdU IHC, and fluorescent bead tracking of peripheral monocytes into the brain, we compared microglial activation in the SVZ to non‐neurogenic forebrain regions. SVZ microglia exhibited greater constitutive activation and proliferation than did microglia in non‐neurogenic regions. In contrast to the SVZ, the dentate gyrus (DG) contained relatively few CD45+ cells. After aspiration cerebral cortex lesions, microglia became activated in the cerebral cortex, corpus callosum, and striatum. SVZ microglial activation did not increase, and similarly, microglia in the DG were less activated after injury than in adjacent non‐neurogenic regions. We next showed that SVZ microglia are not categorically refractory to activation, since deep cortical contusion injuries increased SVZ microglial activation. Macrophages migrate into the brain during development, but it is unclear if this is recapitulated after injury. Infiltration of microbead‐labeled macrophages into the brain did not change after injury, but resident SVZ microglia were induced to migrate toward the injury. Our data show that both constitutive and postlesion levels of microglial activation differ between neurogenic and non‐neurogenic regions. © 2006 Wiley‐Liss, Inc.
Multiple roles of Id4 in developmental myelination: Predicted outcomes and unexpected findings
Authors: Marin‐Husstege Mireya , He Ye , Li Jiadong , Kondo Toru , Sablitzky Fred , Casaccia‐Bonnefil Patrizia
Published: July 2006

Myelination in the central nervous system is a complex process requiring the integration of oligodendrocyte progenitor differentiation and the coordinate expression of myelin genes. This study addresses the role of the helix‐loop‐helix protein Id4 in these two events. Overexpression of Id4 in oligodendrocyte progenitors prevents differentiation and consequently decreases the endogenous expression of all myelin genes. Conversely, progenitors lacking Id4 display precocious differentiation both in vitro and in vivo, and this phenotype is partially compensated by increased apoptosis. Besides this role, Id4 also has the ability to decrease the activity of specific myelin promoters, since Id4 overexpression decreases the activity of luciferase reporter genes driven by the ceramide galactosyltransferase (CGT) or myelin basic protein (MBP) promoter, but not by a myelin proteolipid protein (PLP) promoter. Consistent with these results, the expression levels of MBP and CGT are greater in neonatal Id4 null mice when compared with wild‐type siblings and correlate with the early detection of MBP immunoreactive myelinated fibers. In contrast, the levels of other myelin proteins, such as PLP and myelin associated glycoprotein (MAG) are decreased in the Id4 null mice. MAG expression is localized to the soma rather than the fibers of immunoreactive cells in the neonatal brain and compensated at later developmental stages. These data support the role of Id4 as oligodendrocyte differentiation inhibitor with the ability to differentially regulate the expression and subcellular distribution of myelin gene products. © 2006 Wiley‐Liss, Inc.
The effect of temperature on viscoelastic properties of glass ionomer cements and compomers
Authors: Helvatjoglu‐Antoniades M. , Papadogiannis Y. , Lakes R. S. , Palaghias G. , Papadogiannis D.
Published: July 2006

The objective of this study was to determine the viscoelastic properties of different types of glass ionomer cements (GICs) and compomers under varying temperature conditions found in the mouth. The materials tested were a conventional GIC (Aqua Ionofil U), a resin modified GIC (Fuji II LC), a highly viscous GIC (Voco Ionofil Molar), and two polyacid modified composite resins/compomers (Glasiosite and Dyract Flow). Six groups of four specimens were prepared from each material. One group was stored dry for 24 h and was subsequently tested dry at 21°C. Each of the remaining five groups was stored for 24 h in distilled water at the temperatures 21, 30.5, 37, 43.5, and 50°C, respectively, and was subsequently tested at that temperature. Shear storage modulus and loss tangent were determined by conducting dynamic torsional loading. Static shear moduli were determined by applying a constant torque (below the proportional limit of the materials) for 10 s and recording the angular deformation of the specimens. Data were analyzed by ANOVA and Duncan's test (α= 0.05). It was found that the viscoelastic properties varied significantly (p < 0.05) across the different materials. The compomer Glasiosite, with the highest filler content, and the highly viscous GIC Voco Ionofil Molar exhibited the highest elastic moduli and lowest loss tangents. Viscoelastic properties varied also significantly (p < 0.05) with temperature levels, but changes in the tested region were not indicative of a glass transition. Dynamic shear storage moduli were highly correlated to the static ones. Storage in water lowered the values of elastic moduli. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Biocompatibility of various formula root filling materials for primary teeth
Authors: Huang Tsui‐Hsien , Ding Shinn‐Jyh , Kao Chia‐Tze
Published: July 2006

The aim of this study was to compare the effects of different materials used in primary root canal fillings on the cell viability of human osteosarcoma cell lines. The experimental group contained six different types of root canal filling materials, including zinc oxide (ZnO) + eugenol + formocresol (FC), Ca(OH)2 + FC, Ca(OH)2 + Iodoform, Ca(OH)2 + Iodoform + camphorated parachlorophenol (CPC), Ca(OH)2 + CPC, and Vitapex. Cell viability tests were performed using tetrazolium bromide colorimetric (MTT) assay on human osteosacorma cell lines (U2OS). The results were analyzed using one‐way analysis of variance (ANOVA) and Student–Newman–Keul's test with p < 0.05 showed statistical differences. The ZnO + eugenol + FC group and Ca(OH)2 + FC group showed the lowest survival rates (p < 0.05). The Ca(OH)2 + Iodoform + CPC group and Ca(OH)2 + CPC group showed significantly lower survival rates at concentrations above 6 μL/mL (p < 0.05). The Ca(OH)2 + Iodoform group and Vitapex group showed the highest survival rates (p < 0.05). We concluded that the use of calcium hydroxide with iodoform as a root filling base material is a better option than other medications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Upregulation of matrix metalloproteinase (MMP)‐1 and its activator MMP‐3 of human osteoblast by uniaxial cyclic stimulation
Authors: Sasaki Kan , Takagi Michiaki , Konttinen Yrjö T. , Sasaki Akiko , Tamaki Yasunobu , Ogino Toshihiko , Santavirta Seppo , Salo Jari
Published: July 2006

Proper mechanical loading is essential for bone remodeling and maintenance of human skeletal system. Matrix metalloproteinases (MMPs) are secreted by mesenchymal stromal lining cells and osteoblasts to prepare the initiation sites for osteoclastic bone resorption at the beginning of the remodeling cycle. However, only a few studies have addressed the effect of mechanical stress on MMPs and their endogenous tissue inhibitors of matrix metalloproteinases (TIMPs) in osteoblasts. In this study, the response of human osteoblasts to uniaxial cyclic stretching was investigated to clarify this more in detail. Stretching affected the orientation of the osteoblasts, and quantitative reverse transcription‐polymerase chain reaction revealed coordinated upregulation of MMP‐1 and its activator MMP‐3 mRNA by cyclic 5% stretching at 3 h (p < 0.01). Upregulation of cyclooxygenase‐2 mRNA was also found in response to cyclic 1 and 5% stretchings at 1, 3, and 6 h (p < 0.01). No changes were found in MMP‐2, TIMP‐1, and ‐2. The mRNA expression of MMP‐9 was low and MMP‐13 was not detected. This study suggests that MMP‐1 and ‐3, enhanced by uniaxial cyclic mechanical stimulation of osteoblasts, are candidate key enzymes in the processing of collagen on bone surface, which might be necessary to allow osteoclastic recruitment leading to bone resorption. The strain might also play a role in cleaning of demineralized bone surface during the reversal phase, before bone formation starts. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Evaluation of the growth of chondrocytes and osteoblasts seeded into precision scaffolds fabricated by fused deposition manufacturing
Authors: Hsu Shan‐hui , Yen Hung‐Jen , Tseng Ching‐Shiow , Cheng Chia‐Sheng , Tsai Ching‐Lin
Published: July 2006

In this study, fused deposition manufacturing (FDM) was utilized to fabricate the precision scaffolds for cartilage and bone regeneration. Cell seeding into such scaffolds was evaluated. For poly(D,l‐lactide) (PLA) scaffolds used for cartilage regeneration, the structure with larger inner space, four direction stacking (4D) and small interval of fibers were better. Chondrocyte proliferated well with matrix accumulation in precision scaffolds coated with type II collagen at 4 weeks of in vitro culture. The seeding efficiency of osteoblasts in most polycaprolactone (PCL) scaffolds used for bone regeneration could arrive 50% of original cell seeding density, and the amount of cells in scaffolds increased to double fold after 2 weeks of in vitro culture. The histological cross‐section also revealed proliferation and mineralization of osteoblasts among the PCL fibers. The results indicated that the highly porous and interconnected structure of precision scaffolds could benefit cell ingrowth. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Revenge of the “Sit”: How lifestyle impacts neuronal and cognitive health through molecular systems that interface energy metabolism with neuronal plasticity
Authors: Vaynman Shoshanna , Gomez‐Pinilla Fernando
Published: July 2006

Exercise, a behavior that is inherently associated with energy metabolism, impacts the molecular systems important for synaptic plasticity and learning and memory. This implies that a close association must exist between these systems to ensure proper neuronal function. This review emphasizes the ability of exercise and other lifestyle implementations that modulate energy metabolism, such as diet, to impact brain function. Mechanisms believed to interface metabolism and cognition seem to play a critical role with the brain derived neurotrophic factor (BDNF) system. Behaviors concerned with activity and metabolism may have developed simultaneously and interdependently during evolution to determine the influence of exercise and diet on cognition. Alook into our evolutionary past indicates that our genome remains unchanged from the times of our hunter‐gatherer ancestors, whose active lifestyle predominated throughout almost 100% of humankind's existence. Consequently, the sedentary lifestyle and eating behaviors enabled by the comforts of technologic progress may be reaping “revenge” on the health of both our bodies and brains. In the 21st century we are confronted by the ever‐increasing incidence of metabolic disorders in both the adult and child population. The ability of exercise and diet to impact systems that promote cell survival and plasticity may be applicable for combating the deleterious effects of disease and ageing on brain health and cognition. © 2006 Wiley‐Liss, Inc.
Heat shock protein 27 is involved in neurite extension and branching of dorsal root ganglion neurons in vitro
Authors: Williams Kristy L. , Rahimtula Masuma , Mearow Karen M.
Published: July 2006

Alteration of the cytoskeleton in response to growth factors and extracellular matrix proteins is necessary for neurite growth. The cytoskeletal components, such as actin and tubulin, can be modified through interaction with other cellular proteins, including the small heat shock protein Hsp27. Our previous work suggested that Hsp27 influences neurite growth, potentially via its phosphorylation state interactions with actin. To investigate further the role of Hsp27 in neurite outgrowth of adult dorsal root ganglion (DRG) neurons, we have both down‐regulated endogenous Hsp27 and expressed exogenous Hsp27. Down‐regulation of Hsp27 with Hsp27 siRNA resulted in a decrease of neuritic tree length and complexity. In contrast, expression of exogenous Hsp27 in these neurons resulted in an increase in neuritic tree length and branching. Collectively, these results demonstrate that Hsp27 may play a role in neuritic growth via modulation of the actin cytoskeleton. © 2006 Wiley‐Liss, Inc.
Amyloid β up‐regulates brain‐derived neurotrophic factor production from astrocytes: Rescue from amyloid β‐related neuritic degeneration
Authors: Kimura Nobuyuki , Takahashi Masaki , Tashiro Tomoko , Terao Keiji
Published: July 2006

Astrocytes, the most abundant type of glia in the brain, are considered to play a key role in Alzheimer's disease (AD) pathologies. In a cell culture study, we have previously shown that astroglial responses against amyloid β (Aβ) occur before obvious neuronal damage could be detected, suggesting the possibility that astrocytes might be an attractive therapeutic target for treating AD. In the present study, we investigated astroglial gene expression changes in response to Aβ to elucidate further the role of astrocytes in Aβ toxicity. By using real‐time PCR and ELISA analyses, we found that Aβ rapidly induced astrocytes to produce brain‐derived neurotrophic factor (BDNF). Aβ42 was more effective than Aβ40 in increasing astroglial BDNF production. Moreover, BDNF treatment rescued the neuronally differentiated human neuroblastoma cells from neuritic degeneration caused by Aβ toxicity. This is the first study to demonstrate that astrocytes are capable of increasing the production of a particular neurotrophic factor in response to Aβ. Our findings also identify BDNF as a potential therapeutic agent for preventing Aβ‐related neuritic degeneration. © 2006 Wiley‐Liss, Inc.
Effects of huperzine A on amyloid precursor protein processing and β‐amyloid generation in human embryonic kidney 293 APP Swedish mutant cells
Authors: Peng Ying , Jiang Liying , Lee David Y.W. , Schachter Steven C. , Ma Zhongze , Lemere Cynthia A.
Published: July 2006

The amyloid precursor protein (APP) is cleaved enzymatically by nonamyloidogenic and amyloidogenic pathways. α‐Secretase (α‐secretase), cleaves APP within the β‐amyloid (Aβ) sequence, resulting in the release of a secreted fragment of APP (αAPPs) and precluding Aβ generation. In this study, we investigated the effects of an acetylcholinesterase inhibitor, huperzine A (Hup A), on APP processing and Aβ generation in human embryonic kidney 293 cells transfected with human APP bearing the Swedish mutation (HEK293 APPsw). Hup A dose dependently (0–10 μM) increased αAPPs release and membrane‐coupled APP CTF‐C83, suggesting increased APP metabolism toward the nonamyloidogenic α‐secretase pathway. The metalloprotease inhibitor TAPI‐2 inhibited the Hup A‐induced increase in αAPPs release, further suggesting a modulatory effect of Hup A on α‐secretase activity. The synthesis of full‐length APP and cell viability were unchanged after Hup A incubation, whereas the level of AβTotalwas significantly decreased, suggesting an inhibitory effect of Hup A on Aβ production. Hup A‐induced αAPPs release was significantly reduced by the protein kinase C (PKC) inhibitors GF109203X and Calphostin C. These data, together with the finding that the PKCα level was enhanced prior to the increase of αAPPs secretion, indicate that PKC may be involved in Hup A‐induced αAPPs secretion by HEK293 APPsw cells. Our data suggest alternative pharmacological mechanisms of Hup A relevant to the treatment of Alzheimer's disease. © 2006 Wiley‐Liss, Inc.
Production of nerve growth factor by β‐amyloid‐stimulated astrocytes induces p75NTR‐dependent tau hyperphosphorylation in cultured hippocampal neurons
Authors: Sáez Estefanía T. , Pehar Mariana , Vargas Marcelo R. , Barbeito Luis , Maccioni Ricardo B.
Published: July 2006

Reactive astrocytes surround amyloid depositions and degenerating neurons in Alzheimer's disease (AD). It has been previously shown that β‐amyloid peptide induces inflammatory‐like responses in astrocytes, leading to neuronal pathology. Reactive astrocytes up‐regulate nerve growth factor (NGF), which can modulate neuronal survival by signaling through TrkA or p75 neurotrophin receptor (p75NTR). Here, we analyzed whether soluble Aβ peptide 25–35 (Aβ) stimulated astrocytic NGF expression, modulating the survival of cultured embryonic hippocampal neurons. Hippocampal astrocytes incubated with Aβ up‐regulated NGF expression and release to the culture medium. Aβ‐stimulated astrocytes increased tau phosphorylation and reduced the survival of cocultured hippocampal neurons. Neuronal death and tau phosphorylation were reproduced by conditioned media from Aβ‐stimulated astrocytes and prevented by caspase inhibitors or blocking antibodies to NGF or p75NTR. Moreover, exogenous NGF was sufficient to induce tau hyperphosphorylation and death of hippocampal neurons, a phenomenon that was potentiated by a low steady‐state concentration of nitric oxide. Our findings show that Aβ‐activated astrocytes potently stimulate NGF secretion, which in turn causes the death of p75‐expressing hippocampal neurons, through a mechanism regulated by nitric oxide. These results suggest a potential role for astrocyte‐derived NGF in the progression of AD. © 2006 Wiley‐Liss, Inc.
Suppression of astroglial scar formation and enhanced axonal regeneration associated with functional recovery in a spinal cord injury rat model by the cell cycle inhibitor olomoucine
Authors: Tian Dai‐Shi , Yu Zhi‐Yuan , Xie Min‐Jie , Bu Bi‐Tao , Witte Otto W. , Wang Wei
Published: July 2006

It is well established that axons of the adult mammalian CNS are capable of regrowing only a limited amount after injury. Astrocytes are believed to play a crucial role in the failure to regenerate, producing multiple inhibitory proteoglycans, such as chondroitin sulphate proteoglycans (CSPGs). After spinal cord injury (SCI), astrocytes become hypertrophic and proliferative and form a dense network of astroglial processes at the site of lesion constituting a physical and biochemical barrier. Down‐regulations of astroglial proliferation and inhibitory CSPG production might facilitate axonal regeneration. Recent reports indicated that aberrant activation of cell cycle machinery contributed to overproliferation and apoptosis of cells in various insults. In the present study, we sought to determine whether a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation after SCI in rats. Our results showed that up‐regulations of cell cycle components were closely associated with neuronal cell death and astroglial proliferation as well as the production of CSPGs after SCI. Meanwhile, administration of olomoucine, a selective cell cycle kinase (CDK) inhibitor, has remarkably reduced the up‐regulated cell cycle proteins and then decreased neuronal cell death, astroglial proliferation, and accumulation of CSPGs. More importantly, the treatment with olomoucine has also increased expression of growth‐associated proteins‐43, reduced cavity formation, and improved functional deficits. We consider that suppressing astroglial cell cycle in acute SCIs is beneficial to axonal growth. In the future, therapeutic strategies can be designed to achieve efficient axonal regeneration and functional compensation after traumatic CNS injury. © 2006 Wiley‐Liss, Inc.
On double shearing in frictional materials
Authors: Teunissen J. A. M.
Published: July 2006

This paper evaluates the mechanical behaviour of yielding frictional geomaterials. The general Double Shearing model describes this behaviour. Non‐coaxiality of stress and plastic strain increments for plane strain conditions forms an important part of this model. The model is based on a micro‐mechanical and macro‐mechanical formulation. The stress–dilatancy theory in the model combines the mechanical behaviour on both scales.

It is shown that the general Double Shearing formulation comprises other Double Shearing models. These models differ in the relation between the mobilized friction and dilatancy and in non‐coaxiality. In order to describe reversible and irreversible deformations the general Double Shearing model is extended with elasticity.

The failure of soil masses is controlled by shear mechanisms. These shear mechanisms are determined by the conditions along the shear band. The shear stress ratio of a shear band depends on the orientation of the stress in the shear band. There is a difference between the peak strength and the residual strength in the shear band. While peak stress depends on strength properties only, the residual strength depends upon the yield conditions and the plastic deformation mechanisms and is generally considerably lower than the maximum strength. It is shown that non‐coaxial models give non‐unique solutions for the shear stress ratio on the shear band. The Double Shearing model is applied to various failure problems of soils such as the direct simple shear test, the biaxial test, infinite slopes, interfaces and for the calculation of the undrained shear strength. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of low‐energy laser in the prevention of oral mucositis in children with cancer receiving chemotherapy
Authors: Cruz Luciane B. , Ribeiro Anelise S. , Rech Angela , Rosa Lauro G.N. , Castro Cláudio G. , Brunetto Algemir L.
Published: July 2006

Background

This study assessed the use of low‐energy laser in the prevention or reduction of the severity of oral mucositis.

Procedure

A randomized clinical trial was carried out. Patients from 3 to 18 years of age treated with chemotherapy or hematopoietic stem‐cell transplantation between May, 2003 and February, 2005 were elegible. The intervention group received laser application for 5 days following the start of chemotherapy. The grade of oral mucositis was assessed by the WHO per NCI‐CTC common toxicity criteria and the assessments were made on days 1, 8 and 15 by a trained examiner blind to the intervention.

Results

Sixty patients were evaluable for analysis; thirty‐nine (65%) were males, 35 (58%) patients had a diagnosis of leukemia or lymphoma, and 25 (42%) had solid tumors. The mean age was 8.7 ± 4.3 years. Twenty‐nine patients were randomized in the laser group and 31 in the control group. On day 1, no patients presented with mucositis. On day 8, of 20 patients (36%) who developed mucositis, 13 of them were from the laser group and 7 from the control group. On day 15, of 24 patients (41%) who developed mucositis, 13 of them were from the laser group and 11 from the control group. There was no significant difference between groups concerning the grades of mucositis on day 8 (P = 0.234) or on day 15 (P = 0.208).

Conclusions

This study showed no evidence of benefit from the prophylactic use of low‐energy laser in children and adolescents with cancer treated with chemotherapy when optimal dental and oral care was provided. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.
Enzyme‐catalyzed synthesis of natural and unnatural polysaccharides
Authors: Ohmae Masashi , Fujikawa Shun‐Ichi , Ochiai Hirofumi , Kobayashi Shiro
Published: July 2006

Synthesis of natural and unnatural polysaccharide was achieved via “enzymatic polymerization” by utilizing a glycoside hydrolase as catalyst. Particularly, hyaluronan, chondroitin, and their derivatives belonging to glycosaminoglycans have been prepared using sugar oxazoline monomers designed on the basis of the concept “transition‐state analogue substrate”. The oxazoline derivatives of N‐acetylhyalobiuronate [GlcAβ(1→3)GlcNAc] and N‐acetylchondrosine [GlcAβ(1→3)GalNAc], which have the repeating disaccharide structures of hyaluronan and chondroitin, respectively, were successfully polymerized by the catalysis of hyaluronidase, giving rise to synthetic hyaluronan and chondroitin. Their 2‐substituted oxazoline derivatives were also polymerized to the corresponding N‐acylated hyaluronan and chondroitin derivatives. Furthermore, N‐acetylchondrosine oxazoline derivatives sulfated at the C4, the C6, and both the C4 and C6 of the GalNAc unit were catalyzed by hyaluronidase; the monomer sulfated at the C4 was polymerized to chondroitin 4‐sulfate with well‐defined structure, whereas the other two monomers were exclusively hydrolyzed to the corresponding disaccharides. These different kinds of natural and unnatural polysaccharides having relatively high molecular weights were produced in all cases by the catalysis of hyaluronidase. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5014–5027, 2006
Chirality sensing of various biomolecules with helical poly(phenylacetylene)s bearing acidic functional groups in water
Authors: Onouchi Hisanari , Hasegawa Takashi , Kashiwagi Daisuke , Ishiguro Hiroyuki , Maeda Katsuhiro , Yashima Eiji
Published: July 2006

Stereoregular, cis–transoidal poly(phenylacetylene)s bearing strongly acidic functional groups as pendants, such as a phosphonic acid and its monoethyl ester and a sulfonic acid, were found to interact with various biomolecules such as peptides, proteins, amino sugars, and carbohydrates in water, and the complexes exhibited characteristic induced circular dichroisms in the ultraviolet–visible region of the polymer backbones, which resulted from the formation of predominantly one‐handed helical conformations. On the other hand, the sodium salt of poly[(4‐carboxyphenyl)acetylene], bearing a weak acidic carboxy group, showed induced circular dichroisms only in the presence of carbohydrates and some positively charged proteins. The sensitivity of the polymers to the chirality of various biomolecules was also investigated with circular dichroism spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5039–5048, 2006
Synthesis, properties, and gas permeability of novel poly(diarylacetylene) derivatives
Authors: Sakaguchi Toshikazu , Yumoto Kenichi , Shida Yuichi , Shiotsuki Masashi , Sanda Fumio , Masuda Toshio
Published: July 2006

Poly(diphenylacetylene)s having various silyl groups are soluble in common solvents, from whose membranes poly(diphenylacetylene) membranes can be obtained by desilylation. The oxygen permeability coefficients of the desilylated polymers are quite different from one another (120–3300 barrers) irrespective of the same polymer structure. When bulkier silyl groups are removed, the oxygen permeability increases to larger extents. Poly[1‐aryl‐2‐p‐(trimethylsilyl)phenylacetylene]s are soluble in common solvents, and afford free‐standing membranes. These Si‐containing polymer membranes are desilylated to give the membranes of poly[1‐aryl‐2‐phenylacetylene]s. Both of the starting and desilylated polymers show very high thermal stability and high gas permeability. 1‐Phenyl‐2‐p‐(t‐butyldimethylsiloxy)phenylacetylene polymerizes into a high‐molecular‐weight polymer. This polymer is soluble in common organic solvents to provide a free‐standing membrane. Desilylation of this membrane yields a poly(diphenylacetylene) having free hydroxyl groups, which is the first example of a highly polar group‐carrying poly(diphenylacetylene). The P/P and P/P permselectivity ratios of poly(1‐phenyl‐2‐p‐hydroxylphenylacetylene) membrane are as large as 47.8 and 45.8, respectively, while keeping relatively high P of 110 barrers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5028–5038, 2006
Women's experiences of repeated HPV testing in the context of cervical cancer screening: a qualitative study
Authors: Waller Jo , McCaffery Kirsten , Kitchener Henry , Nazroo James , Wardle Jane
Published: July 2006

Objective: To evaluate the psychosocial impact of taking part in repeated testing for human papillomavirus (HPV) in the context of cervical cancer screening.

Methods: In‐depth interviews were carried out with 30 women who were HPV positive with normal cytology at trial baseline, and attended for a repeat HPV test 12 months later. Interview transcripts were analysed qualitatively using Framework Analysis to identify emergent themes.

Results: Although women often experienced serious negative emotional consequences at the time of their first positive result, these did not generally last during the year between tests once questions about HPV had been resolved. The emotional impact of testing positive a second time was greater for many women, sometimes causing them to overcome their embarrassment about having a sexually transmitted infection in order to disclose their result and seek support. Among the women interviewed there was an overwhelming preference for immediate colposcopy rather than continued surveillance for persistent HPV. This was associated with the desire for a speedy resolution, and fears about progression to cancer.

Conclusions: Although most women did not appear to suffer on‐going anxiety while waiting for a second HPV test, this seemed contingent on their information needs being met. Women appeared to be more distressed by a second HPV positive result than a single one, and expressed a clear preference for immediate colposcopy over continued surveillance. This finding might have implications for the way in which HPV testing could be used in cervical cancer screening programmes. Copyright © 2006 John Wiley & Sons, Ltd.
Starch‐synthase III family encodes a tandem of three starch‐binding domains
Authors: Palopoli Nicolás , Busi María Victoria , Fornasari María Silvina , Gomez‐Casati Diego , Ugalde Rodolfo , Parisi Gustavo
Published: July 2006

The starch‐synthase III (SSIII), with a total of 1025 residues, is one of the enzymes involved in plants starch synthesis. SSIII from Arabidopsis thaliana contains a putative N‐terminal transit peptide followed by a 557‐amino acid SSIII‐specific domain (SSIII‐SD) with three internal repeats and a C‐terminal catalytic domain of 450 amino acids. Here, using computational characterization techniques, we show that each of the three internal repeats encodes a starch‐binding domain (SBD). Although the SSIII from A. thaliana and its close homologous proteins show no detectable sequence similarity with characterized SBD sequences, the amino acid residues known to be involved in starch binding are well conserved. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Characterization of the residual structure in the unfolded state of the Δ131Δ fragment of staphylococcal nuclease
Authors: Francis Christopher J. , Lindorff‐Larsen Kresten , Best Robert B. , Vendruscolo Michele
Published: July 2006

The determination of the conformational preferences in unfolded states of proteins constitutes an important challenge in structural biology. We use inter‐residue distances estimated from site‐directed spin‐labeling NMR experimental measurements as ensemble‐averaged restraints in all‐atom molecular dynamics simulations to characterise the residual structure of the Δ131Δ fragment of staphylococcal nuclease under physiological conditions. Our findings indicate that Δ131Δ under these conditions shows a tendency to form transiently hydrophobic clusters similar to those present in the native state of wild‐type staphylococcal nuclease. Only rarely, however, all these interactions are simultaneously realized to generate conformations with an overall native topology. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Comparison of protein active site structures for functional annotation of proteins and drug design
Authors: Powers Robert , Copeland Jennifer C. , Germer Katherine , Mercier Kelly A. , Ramanathan Viswanathan , Revesz Peter
Published: July 2006

Rapid and accurate functional assignment of novel proteins is increasing in importance, given the completion of numerous genome sequencing projects and the vastly expanding list of unannotated proteins. Traditionally, global primary‐sequence and structure comparisons have been used to determine putative function. These approaches, however, do not emphasize similarities in active site configurations that are fundamental to a protein's activity and highly conserved relative to the global and more variable structural features. The Comparison of Protein Active Site Structures (CPASS) database and software enable the comparison of experimentally identified ligand‐binding sites to infer biological function and aid in drug discovery. The CPASS database comprises the ligand‐defined active sites identified in the protein data bank, where the CPASS program compares these ligand‐defined active sites to determine sequence and structural similarity without maintaining sequence connectivity. CPASS will compare any set of ligand‐defined protein active sites, irrespective of the identity of the bound ligand. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Sensitivity of Raman spectra excited at 325 nm to surface treatments of undoped polycrystalline diamond films
Authors: Ghodbane S. , Deneuville A. , Tromson D. , Bergonzo P. , Bustarret E. , Ballutaud D.
Published: July 2006

About 20 μm thick films were deposited in the same run by MPCVD at 900 °C on Si substrates and then hydrogenated in situ during 30 min with a hydrogen plasma at the same temperature. Their surfaces were kept as prepared or more or less strongly oxidized by annealing at 600 °C under ambient atmosphere or by sulphochromic acid or aqua regia treatments. Raman spectra were excited at 325 and 632.8 nm. Spectra of the as‐prepared sample exhibit structures around 2835 and 2895 cm–1 from monohydride carbon–hydrogen ascribed to the atomically flat (111) and (100) areas, respectively, on the facets of the sample surface crystallites. The decrease of these structures in the normalized spectra after the various oxidation treatments confirms these assignments. The decrease is smaller for the aqua regia treatment than for the two other treatments which give similar effects. Other Raman signals from sp2 C around 1589 cm–1 and CHx bonds around 2930, 2952, 3025 and 3050 cm–1 originate from species at the surface and within the films. Their variation with the oxidizing treatments indicates a significant contribution from the surface species. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
QSTR Study of Small Organic Molecules AgainstTetrahymena pyriformis
Authors: Pasha Farhan Ahmad , Srivastava Hemant Kumar , Srivastava Anupma , Singh Pashupati Prasad
Published: July 2006

The Quantitative Structure–Toxicity Relationship (QSTR) models of various derivatives of phenols, alcohols, esters, aldehydes and ketones have been made with the help of constitutional descriptors, geometrical descriptors, BCUT descriptors, empirical descriptors, topological descriptors and Galvez topol charge indices. In the first step, all the descriptors have been applied on 46 phenol derivatives. The molecular modelling and geometry optimization have been carried out with CAChe pro software. The calculation of descriptors has been done by Dragon software. The topological descriptors provide better results compared to others and have high reliability as indicated by correlation coefficient and cross‐validation coefficient values. The final QSTR models for the other set of compounds made with the help of topological descriptors were only. The values obtained by these QSTR models are in close range with observed toxicity.
Science inquiry and student diversity: Enhanced abilities and continuing difficulties after an instructional intervention
Authors: Lee Okhee , Buxton Cory , Lewis Scott , LeRoy Kathryn
Published: July 2006

This study examines elementary students' abilities to conduct science inquiry through their participation in an instructional intervention over a school year. The study involved 25 third and fourth grade students from six elementary schools representing diverse linguistic and cultural groups. Prior to and at the completion of the intervention, the students participated in elicitation sessions as they conducted a semistructured inquiry task on evaporation. The results indicate that students demonstrated enhanced abilities with some aspects of the inquiry task, but continued to have difficulties with other aspects of the task even after instruction. Although students from all demographic subgroups showed substantial gains, students from non‐mainstream and less privileged backgrounds in science showed greater gains in inquiry abilities than their more privileged counterparts. The results contribute to the emerging literature on designing learning environments that foster science inquiry of elementary students from diverse backgrounds. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 607–636, 2006
Role of bladder neck mobility and urethral closure pressure in predicting outcome of tension‐free vaginal tape (TVT) procedure
Authors: Viereck V. , Nebel M. , Bader W. , Harms L. , Lange R. , Hilgers R. , Emons G.
Published: July 2006

Objective

To investigate how urethral mobility and urethral closure pressure affect the outcome of tension‐free vaginal tape (TVT) insertion for stress incontinence.

Methods

A total of 191 consecutive women with genuine stress urinary incontinence with or without intrinsic sphincter deficiency were evaluated prospectively with multichannel urodynamics, 24‐h voiding diaries, clinical stress tests and introital ultrasound measurements preoperatively and 6 months after surgery. Additional introital ultrasound examinations were performed immediately after the operation, at 12 months and annually thereafter. 177/191 patients had completed a 36‐month follow‐up at the time of writing. Urethral mobility was described as linear dorsocaudal movement (LDM), with hypermobility being defined as LDM > 15 mm on sonography. Intrinsic sphincter deficiency was defined by a maximum urethral closure pressure (MUCP) of <20 cmH2O.

Results

The overall cure rate at the 36‐month follow‐up was 89.5% (Kaplan‐Meier estimator), with secondary cure (within 6 months of surgery) in 10.5% of these patients. The operation failed in 4.2% of the women and recurrence was seen in 6.3% of the cases. Bladder neck mobility was significantly reduced at the 6‐month follow‐up (P < 0.001). Compared with primary cure, therapeutic failure and secondary cure were associated with a significantly lower postoperative bladder neck mobility (P < 0.05). Postoperative hypermobility reduced the risk of therapeutic failure. In addition, women with therapeutic failure or secondary cure had a significantly lower MUCP than did those with primary cure (P < 0.01).

Conclusion

The effectiveness of the TVT sling appears to depend on adequate postoperative urethral mobility and urethral closure pressure. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Adolescents caught between fires: Cognitive emotion regulation in response to war experiences in Northern Uganda
Authors: Amone‐P’Olak Kennedy , Garnefski Nadia , Kraaij Vivian
Published: July 2006

This study aimed to assess the prevalence of war experiences and the use of specific cognitive emotion regulation strategies in response to these experiences among 294 formerly abducted adolescents at three rehabilitation centres in Uganda. Cognitive strategies were measured by Cognitive Emotion Regulation Questionnaire (CERQ). Symptoms of psychopathology were measured by the Impact of Events Scale—Revised (IES‐R) and the Youth Self‐Report (YSR). Relationships were studied by means of descriptive statistics, correlations and Multiple Regression Analyses. Strong relationships were found between specific cognitive emotion regulation strategies and posttraumatic stress (PTS), Internalizing and Externalizing symptoms. The results may have implications for intervention strategies.
Analgesia through the looking‐glass? A randomized controlled trial investigating the effect of viewing a ‘virtual’ limb upon phantom limb pain, sensation and movement
Authors: Brodie Eric E. , Whyte Anne , Niven Catherine A.
Published: July 2006

The extent to which viewing a ‘virtual’ limb, the mirror image of an intact limb, modifies the experience of a phantom limb, was investigated in 80 lower limb amputees before, during and after repeated attempts to simultaneously move both intact and phantom legs. Subjects were randomly assigned to one of two conditions, a control condition in which they only viewed the movements of their intact limb and a mirror condition in which they additionally viewed the movements of a ‘virtual’ limb. Although the mirror condition elicited a significantly greater number of phantom limb movements than the control condition, it did not attenuate phantom limb pain and sensations any more than the control condition. The potential of a ‘virtual’ limb as a treatment for phantom limb pain was discussed in terms of its ability to halt and/or reverse the cortical re‐organisation of motor and somatosensory cortex following acquired limb loss.
Snx5, as a Mind bomb‐binding protein, is expressed in hematopoietic and endothelial precursor cells in zebrafish
Authors: Yoo Kyeong-Won , Kim Eun-Hye , Jung Seung-Hyun , Rhee Myungchull , Koo Bon-Kyoung , Yoon Ki-Jun , Kong Young-Yun , Kim Cheol-Hee
Published: July 2006

Notch signaling has an evolutionarily conserved function for cell fate determination and stem cell maintenance. Previously, we identified a novel component of the Notch signaling pathway in zebrafish, mind bomb, which encodes an E3 ubiquitin ligase essential for Notch signal activation. Further studies showed that Mind bomb
−/− mouse embryos exhibited pan‐Notch phenotypes in various tissues, suggesting that Mind bomb function is conserved in mammals. Therefore we sought to understand the various molecular partners of Mind bomb using yeast two‐hybrid screening. In this search we identified Sorting nexin 5 (Snx5) as a novel interacting partner of Mind bomb. Furthermore we demonstrated that Snx5 colocalizes with Mind bomb in early endosomal compartments, suggesting that Snx5 is important for Mind bomb trafficking. In addition, we identified zebrafish orthologue of Snx5 and showed that snx5 is predominantly expressed in hematopoietic and endothelial precursor cells in zebrafish. We also found defects in hematopoiesis and blood vessel development in snx5 morpholino‐injected embryos. Taken together, we show that Snx5, a novel interacting partner of Mind bomb, may have an essential role for cell fate determination in early development.
Defects of cholesterol biosynthesis
Authors: Waterham Hans R.
Published: July 2006

Eight distinct inherited disorders have been linked to different enzyme defects in the isoprenoid/cholesterol biosynthetic pathway following the finding of abnormally increased levels of intermediate metabolites in patients and confirmed by the demonstration of disease‐causing mutations in genes encoding the implicated enzymes. Patients afflicted with these disorders are characterized by multiple morphogenic and congenital anomalies including internal organ, skeletal and/or skin abnormalities underlining an important role for cholesterol in human embryogenesis and development. The etiology of the underlying pathophysiology may involve multiple affected processes due to lowered cholesterol and/or the elevated, teratogenic levels of the intermediate sterol precursors.
Mice lacking uteroglobin are highly susceptible to developing pulmonary fibrosis
Authors: Lee Yi-Ching , Zhang Zhongjian , Mukherjee Anil B.
Published: July 2006

Uteroglobin (UG) is an anti‐inflammatory protein secreted by the airway epithelia of all mammals. UG‐knockout (UG‐KO) mice sporadically develop focal pulmonary fibrosis (PF), a group of complex interstitial disorders of the lung that has high mortality and morbidity; however, the molecular mechanism(s) remains unclear. We report here that UG‐KO mice are extraordinarily sensitive to bleomycin, an anti‐cancer agent known to induce PF and readily develop PF when treated with an extremely low dose of bleomycin that has virtually no effect on the wild type littermates. We further demonstrate that UG prevents PF suppressing bleomycin‐induced production of pro‐inflammatory T‐helper 2 cytokines and TGF‐β, which are also pro‐fibrotic. Our results define a critical role of UG in preventing the development of PF and provide the proof of principle that recombinant UG may have therapeutic potential.
Negative regulation of protein phosphatase 2Cβ by ISG15 conjugation
Authors: Takeuchi Tomoharu , Kobayashi Takayasu , Tamura Shinri , Yokosawa Hideyoshi
Published: July 2006

ISG15, an interferon‐upregulated ubiquitin‐like protein, is covalently conjugated to various cellular proteins (ISGylation). In this study, we found that protein phosphatase 2Cβ (PP2Cβ), which functions in the nuclear factor κB (NF‐κB) pathway via dephosphorylation of TGF‐β‐activated kinase, was ISGylated, and analysis by NF‐κB luciferase reporter assay revealed that PP2Cβ activity was suppressed by co‐expression of ISG15, UBE1L, and UbcH8. We determined the ISGylation sites of PP2Cβ and constructed its ISGylation‐resistant mutant. In contrast to the wild type, this mutant suppressed the NF‐κB pathway even in the presence of ISG15, UBE1L, and UbcH8. Thus, we propose that ISGylation negatively regulates PP2Cβ activity.