bluuebunny/crossref_metadata_2025 huggingface dataset:
receptor tyrosine phosphataseψ is required for Delta/Notch signalling and cyclic gene expression in the presomitic mesoderm
Authors: Aerne Birgit , Ish-Horowicz David
Published: June 2004

Segmentation in vertebrate embryos is controlled by a biochemical oscillator (`segmentation clock') intrinsic to the cells in the unsegmented presomitic mesoderm, and is manifested in cyclic transcription of genes involved in establishing somite polarity and boundaries. We show that the receptor protein tyrosine phosphatase ψ (RPTPψ) gene is essential for normal functioning of the somitogenesis clock in zebrafish. We show that reduction of RPTPψ activity using morpholino antisense oligonucleotides results in severe disruption of the segmental pattern of the embryo, and loss of cyclic gene expression in the presomitic mesoderm. Analysis of cyclic genes in RPTPψ morphant embryos indicates an important requirement for RPTPψ in the control of the somitogenesis clock upstream of or in parallel with Delta/Notch signalling. Impairing RPTPψ activity also interferes with convergent extension during gastrulation. We discuss this dual requirement for RPTPψ in terms of potential functions in Notch and Wnt signalling.
The necessity of mitochondrial genome DNA for normal development ofDictyosteliumcells
Authors: Chida Junji , Yamaguchi Hitomi , Amagai Aiko , Maeda Yasuo
Published: June 2004

Most unexpectedly, there is now increasing evidence that mitochondria have novel and crucial functions in the regulatory machinery of the growth/differentiation transition, cell-type determination, cellular movement and pattern formation. Here we created ρΔ cells with a reduced amount (about 1/4) of mitochondrial DNA (mtDNA) from Dictyostelium discoideum Ax-2 cells, by exposing Ax-2 cells to ca. 30 μg/ml of ethidium bromide (EtBr) in axenic growth medium. Importantly, the ρΔ cells exhibited a series of fascinating behaviors: when they were starved, they showed a marked delay of differentiation and stopped their development at the slug stage, thus failing to construct fruiting bodies. Moreover, cell patterning and cell-type proportioning were found to be greatly modified in slugs (referred to as ρΔ slugs) derived from ρΔ cells. That is, prestalk differentiation was significantly enhanced in ρΔ slugs, while prespore differentiation was markedly inhibited. In addition, the clear anterior prestalk/posterior prespore pattern was considerably disturbed in ρΔ slugs, presumably because of incomplete sorting between the two types of differentiated cells. After the assay of phototaxis, ρΔ slugs also exhibited highly disordered movement towards the light source. Taken together, these results suggest that mtDNA might have important multiple functions in a variety of cellular processes during Dictyostelium development.
Biological length scale topography enhances cell-substratum adhesion of human corneal epithelial cells
Authors: Karuri Nancy W. , Liliensiek Sara , Teixeira Ana I. , Abrams George , Campbell Sean , Nealey Paul F. , Murphy Christopher J.
Published: June 2004

The basement membrane possesses a rich 3-dimensional nanoscale topography that provides a physical stimulus, which may modulate cell-substratum adhesion. We have investigated the strength of cell-substratum adhesion on nanoscale topographic features of a similar scale to that of the native basement membrane. SV40 human corneal epithelial cells were challenged by well-defined fluid shear, and cell detachment was monitored. We created silicon substrata with uniform grooves and ridges having pitch dimensions of 400-4000 nm using X-ray lithography. F-actin labeling of cells that had been incubated for 24 hours revealed that the percentage of aligned and elongated cells on the patterned surfaces was the same regardless of pitch dimension. In contrast, at the highest fluid shear, a biphasic trend in cell adhesion was observed with cells being most adherent to the smaller features. The 400 nm pitch had the highest percentage of adherent cells at the end of the adhesion assay. The effect of substratum topography was lost for the largest features evaluated, the 4000 nm pitch. Qualitative and quantitative analyses of the cells during and after flow indicated that the aligned and elongated cells on the 400 nm pitch were more tightly adhered compared to aligned cells on the larger patterns. Selected experiments with primary cultured human corneal epithelial cells produced similar results to the SV40 human corneal epithelial cells. These findings have relevance to interpretation of cell-biomaterial interactions in tissue engineering and prosthetic design.
Sequential myofibrillar breakdown accompanies mitotic division of mammalian cardiomyocytes
Authors: Ahuja Preeti , Perriard Evelyne , Perriard Jean-Claude , Ehler Elisabeth
Published: June 2004

The contractile tissue of the heart is composed of individual cardiomyocytes. During mammalian embryonic development, heart growth is achieved by cell division while at the same time the heart is already exerting its essential pumping activity. There is still some debate whether the proliferative activity is carried out by a less differentiated, stem cell-like type of cardiomyocytes or whether embryonic cardiomyocytes are able to perform both of these completely different dynamic tasks, contraction and cell division. Our analysis of triple-stained specimen of cultured embryonic cardiomyocytes and of whole mount preparations of embryonic mouse hearts by confocal microscopy revealed that differentiated cardiomyocytes are indeed able to proliferate. However, to go through cell division, a disassembly of the contractile elements, the myofibrils, has to take place. This disassembly occurs in two steps with Z-disk and thin (actin)-filament-associated proteins getting disassembled before disassembly of the M-bands and the thick (myosin) filaments happens. After cytokinesis reassembly of the myofibrillar proteins to their mature cross-striated pattern can be seen. Another interesting observation was that the cell-cell contacts remain seemingly intact during division, probably reflecting the requirement of intact integration sites of the individual cells in the contractile tissue. Our results suggest that embryonic cardiomyocytes have developed an interesting strategy to deal with their major cytoskeletal elements, the myofibrils, during mitosis. The complex disassembly-reassembly process might also provide a mechanistic explanation, why cardiomyocytes cede to divide postnatally.
Enhanced podocalyxin expression alters the structure of podocyte basal surface
Authors: Economou Constantinos G. , Kitsiou Paraskevi V. , Tzinia Athina K. , Panagopoulou Evridiki , Marinos Evangelos , Kershaw David B. , Kerjaschki Dontscho , Tsilibary Effie C.
Published: June 2004

Glomerular basement membrane (GBM) and podocalyxin are essential for podocyte morphology. We provide evidence of functional interconnections between basement membrane components (collagen IV and laminin), the expression of podocalyxin and the morphology of human glomerular epithelial cells (podocytes). We demonstrated that GBM and laminin, but not collagen IV, up-regulated the expression of podocalyxin. Scanning electron microscopy revealed that laminin induced a modified morphology of podocytes with process formation, which was more extensive in the presence of GBM. Under high magnification, podocytes appeared ruffled. Using transmission electron microscopy we observed that raised areas occurred in the basal cell surface. Furthermore, the presence of anti-podocalyxin antibody increased the extent of adhesion and spreading of podocytes to both collagen IV and laminin, thus podocalyxin apparently inhibits cell-matrix interactions. We also performed adhesion and spreading assays on podocytes grown under increased glucose concentration (25 mM). Under these conditions, the expression of podocalyxin was almost totally suppressed. The cells adhered and spread to basement membrane components but there was no increase in the extent of adhesion and spreading in the presence of anti-podocalyxin antibody, or ruffling of the cell edges. Additionally, in podocytes expressing podocalyxin, the presence of anti-podocalyxin antibody partially reversed the inhibition of adhesion to collagen IV provoked by anti-β1 integrin antibody, thus podocalyxin should compete with β1-related cell adhesion. We suggest that the observed podocalyxin-mediated inhibition of binding to the matrix could be in part responsible for the specialized conformation of the basal surface of podocytes.
Continuous association of cadherin with β-catenin requires the non-receptor tyrosine-kinase Fer
Authors: Xu Gang , Craig Andrew W. B. , Greer Peter , Miller Matthew , Anastasiadis Panos Z. , Lilien Jack , Balsamo Janne
Published: June 2004

The function of Type 1, classic cadherins depends on their association with the actin cytoskeleton, a connection mediated by α- and β-catenin. The phosphorylation state of β-catenin is crucial for its association with cadherin and thus the association of cadherin with the cytoskeleton. We now show that the phosphorylation of β-catenin is regulated by the combined activities of the tyrosine kinase Fer and the tyrosine phosphatase PTP1B. Fer phosphorylates PTP1B at tyrosine 152, regulating its binding to cadherin and the continuous dephosphorylation of β-catenin at tyrosine 654. Fer interacts with cadherin indirectly, through p120ctn. We have mapped the interaction domains of Fer and p120ctn and peptides corresponding to these sequences release Fer from p120ctn in vitro and in live cells, resulting in loss of cadherin-associated PTP1B, an increase in the pool of tyrosine phosphorylated β-catenin and loss of cadherin adhesion function. The effect of the peptides is lost when a β-catenin mutant with a substitution at tyrosine 654 is introduced into cells. Thus, Fer phosphorylates PTP1B at tyrosine 152 enabling it to bind to the cytoplasmic domain of cadherin, where it maintains β-catenin in a dephosphorylated state. Cultured fibroblasts from mouse embryos targeted with a kinase-inactivating ferD743R mutation have lost cadherin-associated PTP1B and β-catenin, as well as localization of cadherin and β-catenin in areas of cell-cell contacts. Expression of wild-type Fer or culture in epidermal growth factor restores the cadherin complex and localization at cell-cell contacts.
Overexpression of myosin IB in living Entamoeba histolytica enhances cytoplasm viscosity and reduces phagocytosis
Authors: Marion Sabrina , Wilhelm Claire , Voigt Heike , Bacri Jean-Claude , Guillén Nancy
Published: June 2004

The human parasite Entamoeba histolytica is an ancient protozoan that expresses only one unconventional myosin, which has homology with myosin IB from other amoebae. Myosin IB is involved in phagocytosis of human cells by E. histolytica. In this work, we developed a microrheological technique, analysing magnetic phagosomes, which allowed us to probe the density of the F-actin network in living cells. Using this technique, we showed that overexpression of myosin IB led to an increase in cytoplasm viscosity, which correlated with a delay in initiating human cell phagocytosis. To investigate which myosin IB domains sustain cell viscosity changes, we overexpressed truncated forms of the protein. Our results demonstrate that both actin-binding sites that are present in the heavy chain but not the SH3 domain are required to modulate the density of the actin network. These data suggested that, as well as the motor activity, myosin IB in E. histolytica plays a structural role on the actin network owing to its ability to cross-link filaments. The gelation state of cell cytoplasm and the dynamics of cortical F-actin during phagocytosis seem to be modulated by the myosin IB structuring cytoskeleton activity.
Fibroblast growth factor 2 endocytosis in endothelial cells proceed via syndecan-4-dependent activation of Rac1 and a Cdc42-dependent macropinocytic pathway
Authors: Tkachenko Eugene , Lutgens Esther , Stan Radu-Virgil , Simons Michael
Published: June 2004

Full activity of fibroblast growth factors (FGFs) requires their internalization in addition to the interaction with cell surface receptors. Recent studies have suggested that the transmembrane proteoglycan syndecan-4 functions as a FGF2 receptor. In this study we investigated the molecular basis of syndecan endocytosis and its role in FGF2 internalization in endothelial cells. We found that syndecan-4 uptake, induced either by treatment with FGF2 or by antibody clustering, requires the integrity of plasma membrane lipid rafts for its initiation, occurs in a non-clathrin-, non-dynamin-dependent manner and involves Rac1, which is activated by syndecan-4 clustering. FGF2 was internalized in a complex with syndecan-4 in 70 kDa dextran-containing endocytic vesicles. FGF2 and syndecan-4 but not dextran endocytosis were blocked by the dominant negative Rac1 while amiloride and the dominant-negative Cdc42 blocked internalization of dextran in addition to FGF2 and syndecan-4. Taken together, these results demonstrate that FGF2 endocytosis requires syndecan-4 clustering-dependent activation of Rac1 and the intact CDC42-dependent macropinocytic pathway.
CD9-mediated activation of the p46 Shc isoform leads to apoptosis in cancer cells
Authors: Murayama Yoko , Miyagawa Jun-ichiro , Oritani Kenji , Yoshida Hitoshi , Yamamoto Katsumi , Kishida Osamu , Miyazaki Tamana , Tsutsui Shusaku , Kiyohara Tatsuya , Miyazaki Yoshiji , Higashiyama Shigeki , Matsuzawa Yuji , Shinomura Yasuhisa
Published: June 2004

CD9, a member of the tetraspanin family, has been shown to be involved in a range of cellular activities, including migration, proliferation and adhesion, but the molecular mechanisms by which it mediates such events is unclear. Here, we found that anti-CD9 monoclonal antibody ALB6 inhibited cell proliferation, reduced cell viability and induced not only morphological changes specific to apoptosis but also molecular changes, as evidenced by TUNEL and annexin-V staining. For the possible mechanism of ALB6-induced apoptosis, ALB6 activated the c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38 mitogen-activated-protein kinase (MAPK) within 5-15 minutes, as well as caspase-3 within 24-48 hours. It is noteworthy that ALB6 induced tyrosine phosphorylation of the p46 Shc isoform specifically and that the overexpression of its dominant-negative form completely suppressed the ALB6-induced activation of JNK/SAPK, p38 MAPK and caspase-3, resulting in the inhibition of apoptotic cell death. These results suggest that CD9 might regulate apoptosis through the specialized signals in human cancer cell lines.
S. pombemeiotic linear elements contain proteins related to synaptonemal complex components
Authors: Lorenz Alexander , Wells Jennifer L. , Pryce David W. , Novatchkova Maria , Eisenhaber Frank , McFarlane Ramsay J. , Loidl Josef
Published: June 2004

The fission yeast Schizosaccharomyces pombe does not form synaptonemal complexes (SCs) in meiotic prophase nuclei. Instead, thin threads, the so-called linear elements (LEs), are observed at the corresponding stages by electron microscopy. Here, we demonstrate that S. pombe Rec10 is a protein related to the Saccharomyces cerevisiae SC protein Red1 and that it localizes to LEs. Moreover, a homologue to S. cerevisiae Hop1 does exist in S. pombe and we show by in situ immunostaining that it, and the kinase Mek1 (a homologue of which is also known to be associated with SCs), localizes to LEs. These observations indicate the evolutionary relationship of LEs with the lateral elements of SCs and suggest that these structures might exert similar functions in S. cerevisiae and S. pombe.
New aspects of nuclear calcium signalling
Authors: Gerasimenko Oleg , Gerasimenko Julia
Published: June 2004

Nuclear calcium signalling has been a controversial battlefield for many years and the question of how permeable the nuclear pore complexes (NPCs) are to Ca2+ has been the subject of a particularly hot dispute. Recent data from isolated nuclei suggest that the NPCs are open even after depletion of the Ca2+ store in the nuclear envelope. Other research has suggested that a new Ca2+-releasing messenger, nicotinic acid adenine dinucleotide phosphate (NAADP), can liberate Ca2+ only from acidic organelles, probably lysosomes, rather than from the traditional Ca2+ store in the endoplasmic reticulum (ER). Recent work indicates that NAADP can release Ca2+ from the nuclear envelope (NE), which has a thapsigargin-sensitive, ER-type Ca2+ store. NAADP acts in a manner similar to inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] or cyclic ADP-ribose (cADPR): all three messengers are equally able to reduce the Ca2+ concentration inside the NE and this is associated with a transient rise in the nucleoplasmic Ca2+ concentration. The NE contains ryanodine receptors (RyRs) and Ins(1,4,5)P3 receptors [Ins(1,4,5)P3Rs], and these can be activated separately and independently: the RyRs by either NAADP or cADPR, and the Ins(1,4,5)P3Rs by Ins(1,4,5)P3.
Finite element and neural network models for process optimization in selective laser sintering
Authors: Boillat E , Kolossov S , Glardon R , Loher M , Saladin D , Levy G
Published: June 2004

An iterative method to optimize non-linear production processes is described. In contrast to classical design-of-experiment methods, it starts with a small number of experiments, based on which a preliminary data-based model is developed. From this model a vector of process parameters with (potentially) improved performance is calculated. The results of the experiment carried out with these new process parameters enlarge the database and result in an improved process model. The iteration is stopped if the requirements of the product properties are fulfilled. The method is applied to the selective laser sintering process of titanium powder. The goal of the optimization is to produce a ring with a prescribed geometry.

One innovation of this approach is to feed the database with experimental results obtained from process simulation. The purpose of the simulation is to use the sintering machine only once to produce a part that is ‘right first time’. The simulation is based on a three-dimensional finite element model of the selective laser sintering process. The input data are the various process parameters and the model is sufficiently detailed to predict the density and the bounding quality (sintering potential) of the manufactured part.
Evolutionary optimization of mould temperature control strategies: Encoding and solving the multiobjective problem with standard evolution strategy and kit for evolution algorithms
Authors: Mehnen J , Micheltisch Th , Bartz-Beielstein Th , Schmitt K
Published: June 2004

A modern injection mould is a high-technology tool for mass production. The products typically have to meet high quality demands because they are often visible to the user. In order to manufacture high quality parts, the temperature of the mould has to be kept at an appropriate level and the temperature has to be equally distributed within the form. A net of interconnected deephole bores leads a water-oil emulsion to the critical areas for controlling the temperatures in the tool. Usually, the layout of the bores is constructed by means of human expert knowledge. In this paper an objective mathematical measure for the multiobjective quality of a mould temperature control system is introduced. Two different encoding approaches for cooling systems are compared. An approach to solve the complex layout problem using an evolutionary algorithm is described. To show the complexity of this multiobjective problem and to interpret and compare the quality of the existing algorithms, a new software environment called KEA (kit for evolutionary algorithms) is used.
General survey of bus frontal collisions: Is regulation needed?
Authors: Matolcsy M
Published: June 2004

This paper tries to collect the main technical problems related to bus frontal collisions, showing examples from everyday practice. This is a general survey about the frontal collisions of buses and does not go into details in the individual subjects. The possibility and the necessity of international regulations is shown, but further studies are required to know how to do it.
Assessing the benefits of implementing micro-CHP systems in the UK
Authors: Newborough M
Published: June 2004

The feasibility of applying combined heat and power rationale to individual homes is discussed, with particular reference to the transient variations that occur in domestic requirements for heat and power. Predicted energy-cost savings, based on simulations employing 1 min demand profiles, are presented for several prospective micro-CHP systems. The effects upon energy-cost savings of prime mover capacity and efficiency, heat-recovery efficiency, central-heating boiler efficiency, and the unit price for exporting electricity are assessed. For various configurations of a nominally 1 kWe micro-CHP system, reductions of 16-39 per cent in annual energy expenditure are identified. Carbon savings per average home of around one tonne of CO2 per annum are predicted, but actual savings will depend strongly upon transient heat-and-power demand variations, the operating mode, capacity and efficiency of the micro-CHP system, and upon the import/export interaction that the household has with the electricity distribution network. If the carbon-reduction potential of this single technical fix is to be maximized, further research attention needs to be given to define preferred implementation strategies for micro-CHP systems in the UK domestic sector.
Scope for reductions in the cost of CO2 capture using flue gas scrubbing with amine solvents
Authors: Gibbins J. R. , Crane R. I.
Published: June 2004

A previous IEA GHG study of CO2 capture from a pulverized coal (PC) power plant using an amine solvent for flue gas scrubbing has been used as the basis for calculations of the reductions in electricity and CO2 avoidance costs that might be achievable through improved thermodynamic integration between the CO2 capture plant and the steam cycle, the use of a solvent with lower regeneration energy requirements and solvent storage to allow rapid load changes and electricity ‘storage’. It was predicted that the efficiency penalty for CO2 capture for PC plant with flue gas scrubbing using an amine solvent can be reduced to 20 per cent (from 28 per cent) with improved thermodynamic integration and lower-energy solvent, giving a 10 per-cent reduction in electricity costs, from $63.5/MW h to $57.4/MW h, and a 25 per cent reduction in the cost of CO2 avoid from $45/t to $34/t. These values are both lower than predictions for the gasifier-based coal power plant in the original IEA GHG study. Reductions in the average cost of electricity of 6–7 per cent were estimated using solvent storage, giving a cost of electricity of $56.73/MW h and $33/t CO2 avoided for an integrated plant with monoethanolamine (MEA) as the solvent. Also, CO2 venting would allow an additional 20-25 per cent increase in output to be maintained indefinitely when $/MW h electricity prices were 2–3 times greater than the $/t penalty for CO2 discharges.
First Transition Metal Complex of 1,8-Bis(dimethylamino)naphthalene (proton sponge)
Authors: Yamasaki Tomoki , Ozaki Nobutaka , Saika Yasunari , Ohta Kozo , Goboh Kenji , Nakamura Fumiko , Hashimoto Masato , Okeya Seichi
Published: June 2004

First transition metal complexes of 1,8-bis(dimethyl-amino)naphthalene (proton sponge), N,N′-chelated Pd(II) complexes, were prepared and the strong coordination ability of the proton sponge was demonstrated. The high transition energy for the coordination could be lowered by the existence of the intermediate charge-transfer complex which was isolated.
A Novel Approach for the Preparation of Silver–silica Nanocomposite
Authors: Mitra Atanu , Imae Toyoko
Published: June 2004

A novel route for the synthesis of silver–silica nanocomposite has been explored. We have employed dendrimer-protected silver nanoparticles, which act as a template to synthesize silica from its precursor on sol–gel processes. It has been observed that in the composite the nanosize silver particles are homogeneously dispersed in the silica matrix.
Valence Electron Rules for Three- and Four-membered Atomic Rings: High-row Representative Elements
Authors: Ding Yi-hong , Takeuchi Kunihiro , Inagaki Satoshi
Published: June 2004

Valence electron rules are proposed for the stability and instability of three- and four-membered atomic rings of high-row representative elements in the singlet states. Regular polygons with 4N + 2 and 8N + 6 valence electrons are the ground states of three- and four-membered rings, respectively. The rules are not necessarily applicable out of the range of the number of valence electrons (Nve): 4m ≤ Nve ≤ 6m for the groups 14–16 and 3m + [1 − (−1)m]/2 ≤ Nve ≤ 6m for the group 13 where m is the number of the ring members.
Optimization of Allocation and Noise Reduction on Multi-Noises System by Using Genetic Algorithm
Authors: Yeh Long-Jyi , Chang Ying-Chun , Chiu Min-Chie
Published: June 2004

An optimization of a layout plan and noise reduction on multi-noises system is considered. In this paper, a novel approach, a genetic algorithm (GA) based on the principles of natural biological evolution, is used as an optimizer. [1]

By GA optimization in adjusting the locations and the required noise reduction for each piece of noisy equipment, the deviation with respect to the targeted noise value along the system's boundary line specified by EPA (Environment Protection Authority) can thus be minimized. In addition, the techniques of binary genetic algorithms (BGA), reproduction, crossover mutation and elitism are applied in GA searching. The numerical cases of multi-noise systems are exemplified. Results show that the correctness of the GA method is acceptable. The optimal design of noise control by adjusting the location and choosing the proper noise reduction measures on equipment proposed in this study offers a quick and economic approach.
Unilateral Coronal Synostosis: A Histomorphometric Study
Authors: Vastardis H. , Mulliken J. B. , Glowacki J.
Published: June 2004

Objective

This histomorphometric study compared the open and prematurely fused side of the coronal suture in subjects with unilateral coronal synostosis (UCS).

Methods

Sutures and parasutural bone were obtained from seven subjects with nonsyndromic UCS during operative correction at 3 to 24 months of age. Histological and cellular analyses were performed for the affected and open sutures. Specimens were examined by light and polarizing microscopy. Sutural patterns, osseous morphology, calvarial thickness, tartrate-resistant acid phosphatase (TRAP)-positive cells, and marrow spaces were evaluated histomorphologically, qualitatively, and semiquantitatively. Histomorphometry was performed to determine total projected area of marrow space as a percentage of unit area, total number of TRAP-positive cells per specimen, and perisutural cranial thickness.

Results

Polarizing microscopy showed that affected sutures were composed of more lamellar bone than the normal sutures. By light microscopy, the clinically fused sutures were 1.7-fold thicker (p < .02), had twofold larger marrow spaces (p < .0006), and contained sixfold more TRAP-positive osteoclasts in marrow spaces near the suture (p < .04) than the normal sutures. Quantitative analysis of the normal sutures revealed that calvarial thickness was greater with age and that there was an inverse correlation between medullary area and age. For the affected sutures, there was also an age-related increase in calvarial thickness. There were also trends for age-related declines in numbers of osteoclasts in both open and affected sides.

Conclusions

These results question the hypothesis that defective osteoclastic activity is pivotal in the pathogenesis of UCS and support the hypothesis that this condition results from abnormally active bony remodeling.
Anencephalic Infant with Cleft Palate and Natal Teeth: A Case Report
Authors: Marakoglu Kamile , Percin E. Ferda , Marakoglu Ismail , Gursoy Ulvi Kahraman , Goze Fahrettin
Published: June 2004

Objective

Natal/neonatal teeth are very common in children with complete unilateral and bilateral cleft lip and palate. This article outlines a patient with intrauterine growth retardation, anencephaly, atrial septal defect, ventricular septal defect, two maxillary first natal incisor teeth, cleft palate, short neck, low-set ears, hypertelorism, retrognathia, and simian-line on the right hand. There is no conclusive evidence of a correlation between these findings and a known syndrome, suggesting that this case may be a hitherto undefined clinical combination with neonatal teeth.
Transforming Growth Factor-α and Nonsyndromic Cleft Lip with or without Palate in Brazilian Patients: Results of a Large Case-Control Study
Authors: Passos-Bueno Maria Rita , Gaspar Dinamar A. , Kamiya Tânia , Tescarollo Graziela , Rabanéa Daniel , Richieri-Costa Antonio , Alonso Nivaldo , Araújo Belmino
Published: June 2004

Objective

Transforming growth factor-α (TGFA) was the first gene suggested to be associated with nonsyndromic cleft lip, cleft palate, or both (CL/ P). There are, however, still controversies of the effect of TGFA on the predisposition of this malformation. To contribute to a better understanding of the role of this gene in the occurrence of CL/P we undertook a case-control study including patients and controls ascertained in different regions of the country.

Design

We examined the C2/TaqI variant of the TGFA gene in 536 patients with nonsyndromic CL/P and 412 controls. The TGFA genotype frequencies in patients were compared with controls using chi-square or Fisher exact test. DNA, obtained from peripheral blood or buccal swabs, was genotyped for the TaqI polymorphism of TGFA.

Setting

The probands and corresponding controls were ascertained in different centers of Brazil, partly representing the ethnic admixture of our population.

Results

The TGFA genotype distribution was very similar in patients with CL/P ascertained in the three different regions of Brazil. However, a discrete difference was observed between controls of Säo Paulo and Ceará (chi-square = 3.605; p = 0.058), with a lower value of the C2/Taq allele frequency in controls of CE (0.04). These data reinforce that this polymorphic system is heterogenous among different ethnic groups. In addition, no evidence was found for an association of TGFA with CL/P in this case-control study.

Conclusion

These data further suggest that TGFA is not a relevant modifier locus for the occurrence of CL/P.
Surgical Significance of Abnormal Internal Carotid Arteries in Velocardiofacial Syndrome in 43 Consecutive Hynes Pharyngoplasties
Authors: Mehendale Felicity V. , Sommerlad Brian C.
Published: June 2004

Objectives

To determine: (1) the incidence of surgically significant, abnormal internal carotid arteries (ICAs) in velocardiofacial syndrome (VCFS); (2) the implications for a Hynes pharyngoplasty; (3) the reliability of preoperative investigations in detecting surgically significant abnormal ICAs.

Design

Prospective data collection with blind reassessment of nasendoscopy recordings.

Setting

Two-site, tertiary referral cleft unit.

Patients

Forty-three consecutive patients with VCFS who underwent a Hynes pharyngoplasty (six had a subsequent revision).

Interventions

Intraoral examinations, lateral videofluoroscopy, nasendoscopy when possible, and intraoperative palpation of the posterolateral pharyngeal walls. Only one patient had a magnetic resonance angiography (MRA).

Main Outcome Measures

Incidence of surgically significant pulsations; modifications to surgical procedure; and correlation of surgical findings with preoperative nasendoscopy and MRA.

Results

Five patients (11.6%) had abnormal pulsations noted at the time of the Hynes. In no patient was the decision to perform a Hynes altered as a result of abnormal pulsations. Two patients had minor adjustments to the Hynes flaps to avoid exposing/damaging the ICA. In one patient an abnormal ICA was exposed during elevation of the left Hynes flap. This was covered uneventfully by routine closure of the secondary defect. Pulsations were noted in only 3 of 24 assessable preoperative nasendoscopies.

Conclusions

A Hynes pharyngoplasty is not contraindicated in VCFS, even if abnormal pulsations are present. Examination and palpation of the pharyngeal walls after the patient is positioned for surgery appear to be reliable in detecting abnormal pulsations and allow accurate surgical planning. Routine vascular imaging, even in patients with pulsations on preoperative nasendoscopy is not essential and may not always be reliable, as shown by the variation in endoscopic, MRA, and intraoperative findings. This further re-emphasizes the importance of palpating the pharyngeal walls once the patient is positioned for surgery.
15 Years of Advanced Materials: Past and Future
Authors: Levy E.
Published: June 2004

2003 marks 15 years of publication of Advanced Materials—the journal’s crystal anniversary. Crystals of all types—from liquid to photonic—have long occupied materials scientists, making this anniversary a particularly relevant one. The events and innovations that have contributed to the present success of Advanced Materials are highlighted in this Editorial and a glimpse is given of what this year holds in store.
Molecular Engineering of Peripherally And Axially Modified Phthalocyanines for Optical Limiting and Nonlinear Optics
Authors: O’Flaherty S.M. , Hold S.V. , Cook M.J. , Torres T. , Chen Y. , Hanack M. , Blau W.J.
Published: June 2004

Phthalocyanines have remarkable chemical and thermal stability and offer tremendous architectural flexibility in their structure, facilitating the tailoring of physical, optoelectronic, and chemical parameters. In this paper, we summarize experimental measurements of nonlinear optical absorption in a comprehensive representative series of modified phthalocyanines substituted with various central metals and peripheral functional groups. Rate equations are used to analytically solve the static‐state conditions that simulate the excited‐state dynamics that result from the nonlinear excited‐state absorption, and this solution is fitted to the experimental data. General molecular engineering trends relating the optical limiting performance of these compounds to their structural characteristics are also explored and discussed.
n‐Type Building Blocks for Organic Electronics: A Homologous Family of Fluorocarbon‐Substituted Thiophene Oligomers with High Carrier Mobility
Authors: Facchetti A. , Mushrush M. , Katz H.E. , Marks T.J.
Published: June 2004

A substantial enhancement of thermal stability, volatility, and electron affinity, switching the semiconducting behavior from p‐ to n‐type, is achieved by fluoroalkyl substitution of thiophene oligomers (see Figure). When this novel series is compared with the fluorine‐free analogues, trends in molecular packing, optical absorption, HOMO–LUMO gap, and π–π interactions are found to be strikingly similar.
Characterization of an Organic Hydrogel: A Cryo‐Transmission Electron Microscopy and X‐ray Diffraction Study
Authors: Estroff L.A. , Leiserowitz L. , Addadi L. , Weiner S. , Hamilton A.D.
Published: June 2004

An insight into the molecular assembly processes that lead ultimately to the gelation of water by small organic molecules can be gained by the combination of two powerful techniques. Vitrified ice cryo‐transmission electron microscopy (TEM) (see Figure) and X‐ray diffraction, have been applied to evaluate the nanoscale structure and molecular organization of an organic hydrogel in its native (hydrated) state.
Isolated Single‐Molecule Magnets on the Surface of a Polymeric Thin Film
Authors: Ruiz‐Molina D. , Mas‐Torrent M. , Gómez J. , Balana A.I. , Domingo N. , Tejada J. , Martínez M.T. , Rovira C. , Veciana J.
Published: June 2004

Individual Mn12 single‐molecule magnets are arranged onto a polymeric film surface using a new, soft, reliable and simple chemical methodology. Polymeric thin films, prepared from a polycarbonate matrix and Mn12 molecules, are subsequently treated with an organic solvent vapor, resulting in nanocomposite thin films that are flexible and optically transparent and could be used for information storage or in quantum computing.
Electrophosphorescence from a Conjugated Copolymer Doped with an Iridium Complex: High Brightness and Improved Operational Stability
Authors: Gong X. , Ostrowski J.C. , Bazan G.C. , Moses D. , Heeger A.J. , Liu M.S. , Jen A.K.‐Y.
Published: June 2004

High efficiency electrophosphorescent light‐emitting diodes (LEDs), with an emission peak at 600 nm, a luminance of 2200 cd m–2, and good operational stability were fabricated from a conjugated copolymer doped with an iridium complex. The devices exhibited an external quantum efficiency of 1.5 % and a luminous efficiency of 3 cd A–1. These results demonstrate that electrophosphorescent devices with high brightness and operational stability can be produced in the form of polymer LEDs fabricated by processing the active materials from solution.
Ceramics Containing Magnetic Co–Fe Alloy Nanoparticles from the Pyrolysis of a Highly Metallized Organometallic Polymer Precursor
Authors: Berenbaum A. , Ginzburg‐Margau M. , Coombs N. , Lough A.J. , Safa‐Sefat A. , Greedan J.E. , Ozin G.A. , Manners I.
Published: June 2004

Lightweight magnetic ceramics containing bimetallic (Co–Fe) nanoparticles in an essentially amorphous C/SiC matrix have been prepared from the pyrolysis of a polyferrocenylsilane with pendant cobalt clusters. The Figure shows a TEM image of the ceramic material formed at 600 °C under N2. Superparamagnetic or ferromagnetic particles may be made, depending on the pyrolysis temperature.
Electroactive Surfactant Designed to Mediate Electron Transfer Between CdSe Nanocrystals and Organic Semiconductors
Authors: Milliron D.J. , Alivisatos A.P. , Pitois C. , Edder C. , Fréchet J.M.J.
Published: June 2004

An electroactive pentathiophene surfactant containing a phosphonic acid head group was designed and shown to provide strong binding to the surface of a CdSe nanocrystal and facilitate charge transfer between the nanocrystal and an organic semiconducting matrix (see Figure). Incorporation into organic–inorganic heterojunction solar cells could improve the efficiency of these promising devices.
Facile Hydrophilic Surface Modification of Poly(tetrafluoroethylene) Using Fluoroalkyl‐Terminated Poly(ethylene glycol)s
Authors: Tae G. , Lammertink R.G.H. , Kornfield J.A. , Hubbell J.A.
Published: June 2004

Hydrophilic surface modification of poly(tetrafluoroethylene) (PTFE) has been carried out by coating with a thin layer of fluoroalkyl‐ terminated poly(ethylene gylcol) (PEG). The coating layer adheres by hydrophobic interactions and is stable, in accord with the sol–gel behavior of the bulk polymer. Stable hydrogel arrays have been prepared by e.g., solvent‐ assisted micromolding on a perfluorosilanized substrate (see Figure).
Fabrication of Germanium‐Filled Silica Nanotubes and Aligned Silica Nanofibers
Authors: Hu J.‐Q. , Meng X.‐M. , Jiang Y. , Lee C.‐S. , Lee S.‐T.
Published: June 2004

Germanium‐filled SiO2 nanotubes and aligned SiO2 nanofibers are synthesized via a two‐stage process: thermal evaporation of SiO powder, followed by laser ablation of a Ge target. The nanotubes are either partially filled with Ge nanoparticles/nanorods or completely filled with Ge nanowires, forming Ge/SiO2 nanocables (see Figure). The products were characterized using a variety of spectroscopic techniques.
Preparation of Large‐Area 3D Ordered Macroporous Titania Films by Silica Colloidal Crystal Templating
Authors: Kuai S. , Badilescu S. , Bader G. , Brüning R. , Hu X. , Truong V.‐V.
Published: June 2004

Highly ordered macroporous titania films (see Figure) can be prepared over large areas using colloidal silica spheres as a template. This template material has a number of advantages over the more commonly used polystyrene spheres, such as easy removal of the template by immersion in a warm NaOH solution and shrinkage of the macroporous framework by less than 3 %.
Self‐Assembled Surface Patterns of Binary Colloidal Crystals
Authors: Kitaev V. , Ozin G.A.
Published: June 2004

Co‐assembly of binary dispersions of monodisperse microspheres with large size ratios has been used to produce well‐ordered hexagonally close‐packed monolayers of large spheres with a superimposed pattern of small spheres (see Figure). The architectures obtained are determined by the size and concentration ratios of the microspheres in the dispersions, are very diverse, and can be obtained reproducibly over millimeter length scales.
NLGN3/NLGN4 gene mutations are not responsible for autism in the Quebec population
Authors: Gauthier Julie , Bonnel Anna , St‐Onge Judith , Karemera Liliane , Laurent Sandra , Mottron Laurent , Fombonne Éric , Joober Ridha , Rouleau Guy A.
Published: June 2004

Jamain [2003: Nat Genet 34:27–29] recently reported mutations in two neuroligin genes in sib‐pairs affected with autism. In order to confirm these causative mutations in our autistic population and to determine their frequency we screened 96 individuals affected with autism. We found no mutations in these X‐linked genes. These results indicate that mutations in NLGN3 and NLGN4 genes are responsible for at most a small fraction of autism cases and additional screenings in other autistic populations are needed to better determine the frequency with which mutations in NLGN3 and NLGN4 occur in autism. © 2004 Wiley‐Liss, Inc.
Positive association of the human frizzled 3 (FZD3) gene haplotype with schizophrenia in Chinese Han population
Authors: Zhang Yanbo , Yu Xin , Yuan Yanbo , Ling Yansu , Ruan Yan , Si Tianmei , Lu Tianlian , Wu Suping , Gong Xiaohong , Zhu Zhongjun , Yang Jianzhong , Wang Fei , Zhang Dai
Published: June 2004

Frizzled 3 (FZD3) gene is located on chromosome 8p21, a region that has been implicated in schizophrenia in genetic linkage studies. The FZD3 is a transmembrane receptor required for Wnt signal transduction cascades that have been thought to be involved in producing the cytoarchitectural defects observed in schizophrenia. Previous work has showed a strong association between FZD3 locus and schizophrenia in family‐based study. To confirm this issue further, we investigated a genetic association between four single nucleotide polymorphisms (SNPs) located in the FZD3 gene and schizophrenia by case‐control study using polymerase chain reaction (PCR)‐based restriction fragment length polymorphism (RFLP) in the Chinese Han population. Our studies showed the SNPs rs2323019 and rs880481 have significant differences in both genotype and allele frequencies between control subjects and schizophrenic patients (rs2323019: Allele A > G, χ2 = 6.7277, df = 1, P = 0.0095; Genotype, χ2 = 10.6583, df = 2, P = 0.0049; rs880481: Allele A > G, χ2 = 10.3945, df = 1, P = 0.0013; Genotype, χ2 = 16.8049, df = 2, P = 0.0002). In addition, we constructed three‐locus haplotypes to test their association with schizophrenia. The globe chi‐squared test for haplotype analysis showed a significant association (χ2 = 66.38, df = 7, P < 0.000001). These results suggested that the FZD3 gene might be involved in the predisposition to schizophrenia. © 2004 Wiley‐Liss, Inc.
Myelin oligodendrocyte glycoprotein (MOG) gene is associated with obsessive‐compulsive disorder
Authors: Zai Gwyneth , Bezchlibnyk Yarema B. , Richter Margaret A. , Arnold Paul , Burroughs Eliza , Barr Cathy L. , Kennedy James L.
Published: June 2004

Obsessive‐compulsive disorder (OCD) is a severe neuropsychiatric disorder with a strong genetic component, and may involve autoimmune processes. Support for this latter hypothesis comes from the identification of a subgroup of children, described by the term pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS), with onset of OCD symptoms following streptococcal infections. Genes involved in immune response therefore represent possible candidate genes for OCD, including the myelin oligodendrocyte glycoprotein (MOG) gene, which plays an important role in mediating the complement cascade in the immune system. Four polymorphisms in the MOG gene, a dinucleotide CA repeat (MOG2), a tetranucleotide TAAA repeat (MOG4), and 2 intronic single nucleotide polymorphisms, C1334T and C10991T, were investigated for the possibility of association with OCD using 160 nuclear families with an OCD proband. We examined the transmission of alleles of these four polymorphisms with the transmission disequilibrium test (TDT). A biased transmission of the 459‐bp allele (allele 2: χ2 = 5.255, P = 0.022) of MOG4 was detected, while MOG2, C1334T, and C10991T showed no statistically significant bias in the transmission of alleles. The transmission of the C1334T.MOG2.C10991T.MOG4 haplotype 1.13.2.2 (χ2 = 6.426, P = 0.011) was also significant. Quantitative analysis using the family‐based association test (FBAT) was significant for MOG4 in total Yale‐Brown Obsessive‐Compulsive Scale severity score (allele 2: z = 2.334, P = 0.020). Further investigations combining genetic, pathological, and pharmacological strategies, are warranted. © 2004 Wiley‐Liss, Inc.
Regulator of G‐protein signaling 4 (RGS4) gene is associated with schizophrenia in Irish high density families
Authors: Chen Xiangning , Dunham Cynthia , Kendler Seth , Wang Xu , O'Neill F. Anthony , Walsh Dermot , Kendler Kenneth S.
Published: June 2004

The regulator of the G‐protein signaling 4 (RGS4) gene was shown to have a different expression pattern in schizophrenia patients in a microarray study. A family‐based study subsequently implicated the association of this gene with schizophrenia. We replicated the study with our sample from the Irish Study of High Density Schizophrenia Families (ISHDSF). Single marker transmission disequilibrium tests (TDT) for the four core SNPs showed modest association for SNP 18 (using a narrow diagnostic approach with FBAT P = 0.044; with PDT P = 0.0073) and a trend for SNP 4 (with FBAT P = 0.1098; with PDT P = 0.0249). For SNP 1 and 7, alleles overtransmitted to affected subjects were the same as previously reported. Haplotype analyses suggested that haplotype G‐G‐G for SNP1–4–18, which is the most abundant haplotype (42.3%) in the Irish families, was associated with the disease (narrow diagnosis, FBAT P = 0.0061, PDT P = 0.0498). This was the same haplotype implicated in the original study. While P values were not corrected for multiple testing because of the clear prior hypothesis, these results could be interpreted as supporting evidence for the association between RGS4 and schizophrenia. © 2004 Wiley‐Liss, Inc.
Diffuse axonal injury in children: Clinical correlation with hemorrhagic lesions
Authors: Tong Karen A. , Ashwal Stephen , Holshouser Barbara A. , Nickerson Joshua P. , Wall Christopher J. , Shutter Lori A. , Osterdock Renatta J. , Haacke E. M. , Kido Daniel
Published: June 2004

An inception cohort of 40 children and adolescents with traumatic brain injury and suspected diffuse axonal injury were studied using a new high‐resolution magnetic resonance imaging susceptibility‐weighted technique that is very sensitive for hemorrhage. A blinded comparison was performed between the extent of parenchymal hemorrhage and initial clinical variables as well as outcomes measured at 6 to 12 months after injury. Children with lower Glasgow Coma Scale scores (≤8, n = 30) or prolonged coma (>4 days, n = 20) had a greater average number (p = 0.007) and volume (p = 0.008) of hemorrhagic lesions. Children with normal outcomes or mild disability (n = 30) at 6 to 12 months had, on average, fewer hemorrhagic lesions (p = 0.003) and lower volume (p = 0.003) of lesions than those who were moderately or severely disabled or in a vegetative state. Significant differences also were observed when comparing regional injury to clinical variables. Because susceptibility‐weighted imaging is much more sensitive than conventional T2*‐weighted gradient‐echo sequences in detecting hemorrhagic diffuse axonal injury, more accurate and objective assessment of injury can be obtained early after insult, and may provide better prognostic information regarding duration of coma as well as long‐term outcome. Ann Neurol 2004;56:36–50