bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinal cord oligodendroglioma with 1p and 19q deletions presenting with cerebral oligodendrogliomatosis
Authors: Guppy Kern H. , Akins Paul T. , Moes Gregory S. , Prados Michael D.
Published: September 2009

Oligodendroglioma of the spinal cord is a rare tumor that most often presents with spinal cord symptoms. The authors present a case of spinal cord oligodendroglioma that was associated with cerebral rather than spinal cord symptoms. A 30-year-old woman developed nausea, vomiting, and severe headaches. Magnetic resonance imaging of the brain showed meningeal enhancement. The patient underwent a craniotomy with biopsies of the meninges and brain. The biopsy findings revealed an abnormal arachnoid thickening without tumor cells. The patient later developed hydrocephalus and underwent shunt placement. Cerebrospinal fluid cytological findings were negative for tumor cells or infection. She was found to have a cervical cord lesion at C3–4 that was initially nonenhancing but later enhanced after Gd administration. Biopsy of the cord lesion with partial resection showed a WHO Grade II oligodendroglioma with 1p and 19q deletions determined by fluorescence in situ hybridization. Neurooncological treatment with tumor radiation and temozolomide (Temodor) resulted in improvement in radiographic findings, symptoms, and long-term survival. This paper presents an extensive review of the literature, which revealed only 2 other reported cases of cerebral symptoms in adults that preceded spinal cord symptoms in a patient with oligodendroglioma of the spinal cord. It is also the first reported case of oligodendrogliomatosis due to a cervical spinal cord oligodendroglioma with 1p and 19q deletions.
Schafalpung – Erfahrungen mit der Sömmerungsbeitragsverordnung (Essay) | Sheep on the alpine pastures – experiences with the ordinance concerning the summer pasturing contribution (essay)
Authors: Stadler Franz
Published: September 2009

For approximately nine years the summer pasturing of sheep in the Swiss Alps has been regulated by an ordinance. This has led to a positive development in sheep management. Nevertheless, various problems still arise, especially those concerning the selection of areas not to be used as pasture, the calculation of the nett pasture area and the use of higher situations after the 1st August. In the article these difficulties are explained and propositions are put forward for a coherent application of the summer pasturing contribution.
Ergebnisse aus Untersuchungen zum Wildtiereinfluss auf die Waldverjüngung in der Schweiz | Results of various studies on the influence of wildlife on forest regeneration in Switzerland
Authors: Odermatt Oswald
Published: September 2009

Ten years ago the working group “Forest and Wildlife” of the Swiss Forestry Society described the situation at the time regarding forest and game in Switzerland. Since then data collection and evaluation methods for assessing browsing damage, but also forest and wildlife management concepts have evolved. A selection of the many activities in this field are presented in this article, namely the cantonal overviews of Cantons Glarus, Schwyz and Berne, the surveys on browsing intensity on indicator plots in Cantons St. Gallen, Glarus, Zurich, Schwyz and in the Bernese Oberland, as well as the Forest and Wildlife Reports and the Silver Fir Action Program of Canton Grisons. Furthermore the results of the Effor2 pilot program “forest and wildlife” and of the studies on the development of natural regeneration and the behaviour of wild ungulates in areas damaged by storm Lothar are presented, together with results from the 3rd National Forest Inventory.

The results show: the proportion of forest area in the cantons with intolerable browsing damage seldom exceeds 25%. Browsing problems are more frequent in game protection areas. According to the 3rd National Forest Inventory browsing intensity has increased in Switzerland, but decreased in the Plateau. A diminution of the browsing intensity is also shown by the the surveys on indicator plots in Cantons St. Gallen, Glarus, Zurich, Schwyz and in the Bernese Oberland. In some regions one has succeeded in avoiding a loss of stem numbers due to browsing, even concerning the particularly vulnerable silver fir. This however remains the exception rather than the rule. This is the reason why Canton Grisons has launched the Silver Fir Action Program.
Wintertourismus beeinflusst das Verhalten und die Stressphysiologie des Auerhuhns | Winter tourism influences the behaviour and the stress physiology of the capercaillie
Authors: Mollet Pierre , Thiel Dominik
Published: September 2009

The present study investigated whether the flushing distance, the territorial use and the stress hormone physiology of the capercaillie (Tetrao urogallus) were influenced in the winter by the presence of a large number of people engaged in sporting activities. In most cases flushing distances were greater, and higher concentrations of stress hormone were found in the blood serum, in areas having a high intensity of sporting activities than in forest stands relatively undisturbed by tourists. During the ski season capercaillie avoided forest patches within their home ranges where there was a high level of recreational activity. The results lead to the conclusion that intensive winter tourism can be a serious threat to the remaining capercaillie populations in middle Europe. It is recommended that the construction of new recreational facilities and new developments should be avoided in the most important habitats for capercaillie. The important habitats which today already lie in the immediate vicinity of areas intensively used by tourists could clearly receive enhanced status, according to each situation, either as tranquility areas for wildlife where entrance is forbidden or with regulations requiring winter tourists to stay on trails.
Investigating the Effect of Large Wind Farms on Energy in the Atmosphere
Authors: Sta. Maria Magdalena  R. V. , Jacobson Mark  Z.
Published: September 2009

This study presents a parameterization of the interaction between wind turbines and the atmosphere and estimates the global and regional atmospheric energy losses due to such interactions. The parameterization is based on the Blade Element Momentum theory, which calculates forces on turbine blades. Should wind supply the world’s energy needs, this parameterization estimates energy loss in the lowest 1 km of the atmosphere to be ~0.007%. This is an order of magnitude smaller than atmospheric energy loss from aerosol pollution and urbanization, and orders of magnitude less than the energy added to the atmosphere from doubling CO2. Also, the net heat added to the environment due to wind dissipation is much less than that added by thermal plants that the turbines displace.
Contrasting Electricity Demand with Wind Power Supply: Case Study in Hungary
Authors: Kiss Péter , Varga László , Jánosi Imre  M.
Published: September 2009

We compare the demand of a large electricity consumer with supply given by wind farms installed at two distant geographic locations. Obviously such situation is rather unrealistic, however our main goal is a quantitative characterization of the intermittency of wind electricity. The consumption pattern consists of marked daily and weekly cycles interrupted by periods of holidays. In contrast, wind electricity production has neither short-time nor seasonal periodicities. We show that wind power integration over a restricted area cannot provide a stable baseload supply, independently of the excess capacity. Further essential result is that the statistics are almost identical for a weekly periodic pattern of consumption and a constant load of the same average value. The length of both adequate supply and shortfall intervals exhibits a scale-free (power-law) frequency distribution, possible consequences are shortly discussed.
Games: An Interdisciplinary Open Access Journal
Authors: Alós-Ferrer Carlos
Published: September 2009

Over the last fifty years, game theory has evolved from a mathematical theory of optimal behaviour in stylized situations (“games”) to a general theory of human behaviour, be it actually observed or normatively desirable. Its scope includes both the mathematical modelling and analysis of competition and conflict and the study of human behaviour in strategic contexts and its determinants. Nowadays, game theory has become the language of economics and is increasingly becoming one of the main methods of analysis in several social sciences. Its theoretical underpinnings can be viewed as a mathematical subdiscipline, while its more behavioural offshoots benefit from cross-fertilization with psychology. Game theory has grown within economics but is, by its very nature, interdisciplinary, to the extent that no game theorist can or should define him or herself in disciplinary terms anymore. [...]
Theoretical Study on Reactions of Triplet Excited State Thioxanthone with Indole
Authors: Shen Liang , Ji Hong-Fang
Published: September 2009

In the present work, a theoretical study on the deactivation of triplet excited (T1) state thioxanthone (TX) by indole (INH) was performed, based on density functional theory calculations. Three feasible pathways, namely direct electron transfer from INH to T1 state TX, electron transfer followed by proton transfer from INH·+ to TX·– , and H-atom transfer from nitrogen of INH to keto oxygen of T1 state TX, were proposed theoretically to be involved in T1 state TX deactivation by INH.
Biocompatibility of Different Nerve Tubes
Authors: Stang Felix , Keilhoff Gerburg , Fansa Hisham
Published: September 2009

Bridging nerve gaps with suitable grafts is a major clinical problem. The autologous nerve graft is considered to be the gold standard, providing the best functional results; however, donor site morbidity is still a major disadvantage. Various attempts have been made to overcome the problems of autologous nerve grafts with artificial nerve tubes, which are “ready-to-use” in almost every situation. A wide range of materials have been used in animal models but only few have been applied to date clinically, where biocompatibility is an inevitable prerequisite. This review gives an idea about artificial nerve tubes with special focus on their biocompatibility in animals and humans.
Hydroxyapatite/MCM-41 and SBA-15 Nano-Composites: Preparation, Characterization and Applications
Authors: Anunziata Oscar A. , Martínez Maria L. , Beltramone Andrea R.
Published: September 2009

Composites of hydroxyapatite (HaP) and highly ordered large pore mesoporous silica molecular sieves such as, Al-SBA-15 and Al-MCM-41 (denoted as SBA-15 and MCM-41. respectively) were developed, characterized by XRD, BET, FTIR, HRTEM and NMR-MAS, and applied to fluoride retention from contaminated water. The proposed procedure by a new route to prepare the HaP/SBA-15 and HaP/MCM-41, composites generates materials with aluminum only in tetrahedral coordination, according to the 27Al NMR-MAS results. Free OH- groups of HaP nanocrystals, within the hosts, allowed high capacity fluoride retention. The activity of fluoride retention using HaP/MCM-41 or HaP/SBA-15 was 1-2 orders of magnitude greater, respectively, than with pure HaP.
Inhibitory Effect of Three C-glycosylflavonoids from Cymbopogon citratus (Lemongrass) on Human Low Density Lipoprotein Oxidation
Authors: Orrego Roxana , Leiva Elba , Cheel José
Published: September 2009

This study assessed the inhibitory effect of three C-glycosylflavonoids from Cymbopogon citratus leaves - isoorientin (1), swertiajaponin (2) and isoorientin 2"-Orhamnoside (3) - on human LDL oxidation. Isolated LDL was incubated with compounds 1-3 and the kinetics of lipid peroxidation were assessed by conjugated diene and malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) formation after addition of copper ions. Significant differences (p < 0.05) between the lag time phase of the control and the lag time phase in the presence of the compounds 1 (0.25 µM) and 2 (0.50 µM) were observed. After five hours of incubation all three compounds showed a significant inhibitory effect on MDA-TBARS formation with respect to the control. After six hours of incubation only compound 1 kept a remarkable antioxidant effect. This study demonstrates that isoorientin (1) is an effective inhibitor of in vitro LDL oxidation. As oxidative damage to LDL is a key event in the formation of atherosclerotic lesions, the use of this natural antioxidant may be beneficial to prevent or attenuate atherosclerosis.
Solid-Phase Synthesis of Optically Active Substituted 2 Aminofuranones Using an Activated Carbonate Linker
Authors: Matiadis Dimitris , Prousis Kyriakos  C. , Igglessi-Markopoulou Olga
Published: September 2009

An efficient three-step solid-phase synthesis of diverse 3,5-disubstituted-2-aminofuranones has been developed. α-Hydroxy acids loaded on a nitrophenyl carbonate derivative of Wang resin are used as acylating agents for the C-acylation of active methylene compounds and the resulting intermediates provided, through a cyclative cleavage reaction, the desired product.
Resonant Magnetic Field Sensors Based On MEMS Technology
Authors: Herrera-May Agustín  L. , Aguilera-Cortés Luz  A. , García-Ramírez Pedro  J. , Manjarrez Elías
Published: September 2009

Microelectromechanical systems (MEMS) technology allows the integration of magnetic field sensors with electronic components, which presents important advantages such as small size, light weight, minimum power consumption, low cost, better sensitivity and high resolution. We present a discussion and review of resonant magnetic field sensors based on MEMS technology. In practice, these sensors exploit the Lorentz force in order to detect external magnetic fields through the displacement of resonant structures, which are measured with optical, capacitive, and piezoresistive sensing techniques. From these, the optical sensing presents immunity to electromagnetic interference (EMI) and reduces the read-out electronic complexity. Moreover, piezoresistive sensing requires an easy fabrication process as well as a standard packaging. A description of the operation mechanisms, advantages and drawbacks of each sensor is considered. MEMS magnetic field sensors are a potential alternative for numerous applications, including the automotive industry, military, medical, telecommunications, oceanographic, spatial, and environment science. In addition, future markets will need the development of several sensors on a single chip for measuring different parameters such as the magnetic field, pressure, temperature and acceleration.
Optimization of TiO2 and PMAPTAC Concentrations of a Chemical Humidity Sensing Mechanism
Authors: Kouda Souhil , Dibi Zohir , Dendouga Abdelghani , Meddour Fayçal , Barra Samir
Published: September 2009

This work aims to achieve an optimization of the TiO2 and PMAPTAC concentrations in a chemical resistive-type humidity sensing mechanism (RHSM). Our idea is based primarily on the modeling of the sensing mechanism. This model takes into account the parameters of non-linearity, hysteresis, temperature, frequency, substrate type. Furthermore, we investigated the TiO2 and PMAPTAC effects concentrations on the humidity sensing properties in our model. Secondly, we used the Matlab environment to create a database for an ideal model for the sensing mechanism, where the response of this ideal model is linear for any value of the above parameters. We have done the training to create an analytical model for the sensing mechanism (SM) and the ideal model (IM). After that, the SM and IM models are established on PSPICE simulator, where the output of the first is identical to the output of the RHSM used and the output of the last is the ideal response. Finally a “DIF bloc” was realized to make the difference between the SM output and the IM output, where this difference represents the linearity error, we take the minimum error, to identify the optimal TiO2 and PMAPTAC concentrations. However, a compromise between concentrations, humidity and temperature must be performed. The simulation results show that in low humidity and at temperature more than 25 °C, sample 1 is the best (in alumina substrate). However, the sample 9 represents the best sensor (in PET substrate) predominately for the lowest humidity and temperature.
Synthesis Methods, Microscopy Characterization and Device Integration of Nanoscale Metal Oxide Semiconductors for Gas Sensing
Authors: Vander Wal Randy  L. , Berger Gordon  M. , Kulis Michael  J. , Hunter Gary  W. , Xu Jennifer  C. , Evans Laura
Published: September 2009

A comparison is made between SnO2, ZnO, and TiO2 single-crystal nanowires and SnO2 polycrystalline nanofibers for gas sensing. Both nanostructures possess a one-dimensional morphology. Different synthesis methods are used to produce these materials: thermal evaporation-condensation (TEC), controlled oxidation, and electrospinning. Advantages and limitations of each technique are listed. Practical issues associated with harvesting, purification, and integration of these materials into sensing devices are detailed. For comparison to the nascent form, these sensing materials are surface coated with Pd and Pt nanoparticles. Gas sensing tests, with respect to H2, are conducted at ambient and elevated temperatures. Comparative normalized responses and time constants for the catalyst and noncatalyst systems provide a basis for identification of the superior metal-oxide nanostructure and catalyst combination. With temperature-dependent data, Arrhenius analyses are made to determine activation energies for the catalyst-assisted systems.
Determination of Diclofenac on a Dysprosium Nanowire- Modified Carbon Paste Electrode Accomplished in a Flow Injection System by Advanced Filtering
Authors: Daneshgar Parandis , Norouzi Parviz , Ganjali Mohammad Reza , Dinarvand Rasoul , Moosavi-Movahedi Ali Akbar
Published: September 2009

A new detection technique called Fast Fourier Transform Square-Wave Voltammetry (FFT SWV) is based on measurements of electrode admittance as a function of potential. The response of the detector (microelectrode), which is generated by a redox processes, is fast, which makes the method suitable for most applications involving flowing electrolytes. The carbon paste electrode was modified by nanostructures to improve sensitivity. Synthesized dysprosium nanowires provide a more effective nanotube-like surface [1-4] so they are good candidates for use as a modifier for electrochemical reactions. The redox properties of diclofenac were used for its determination in human serum and urine samples. The support electrolyte that provided a more defined and intense peak current for diclofenac determination was a 0.05 mol L−1 acetate buffer pH = 4.0. The drug presented an irreversible oxidation peak at 850 mV vs. Ag/AgCl on a modified nanowire carbon paste electrode which produced high current and reduced the oxidation potential by about 100 mV. Furthermore, the signal-to-noise ratio was significantly increased by application of a discrete Fast Fourier Transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. To obtain the much sensivity the effective parameters such as frequency, amplitude and pH was optimized. As a result, CDL of 2.0 × 10−9 M and an LOQ of 5.0 × 10−9 M were found for the determination for diclofenac. A good recovery was obtained for assay spiked urine samples and a good quantification of diclofenac was achieved in a commercial formulation.
The Effect of Race on the Incidence of Retinoblastoma
Authors: Krishna Sheila M. , Yu Guo-Pei , Finger Paul T.
Published: September 2009

Purpose:

To examine the incidence of retinoblastoma for regional variations by race.

Methods:

Age-adjusted incidence rates, rate ratios, and 95% confidence intervals were determined in 109 regions from 1993 to 1997 using compiled data from the International Agency for Research on Cancer.

Results:

The rate ratio was 1.12 (range: 0.35 to 4.15) between white populations in the United States and Europe/Australia, 0.98 (range: 0.37 to 2.65) between Hispanic populations in Spain and the United States, and 1.44 (range: 0.29 to 1.79) between Hispanic populations in Uruguay and the United States. The rate ratio between Hispanic and white populations within the United States was 0.94 (range: 0.33 to 2.56). No differences were significant.

Conclusions:

Because retinoblastoma is a genetic disease, its incidence is similar among varied populations.

[J Pediatr Ophthalmol Strabismus 2009;46:288–293.]
Multiple Anterior and Posterior Chamber Pseudocysts in a 12-Year-Old Boy With Diffuse Infiltrating Retinoblastoma
Authors: Tuncer Samuray , Peksayar Gonul , Kebudi Rejin , Tugal-Tutkun Ilknur , Buyukbabani Nesimi , Darendeliler Emin
Published: September 2009

Diffuse infiltrating retinoblastoma is a rare subtype, occurring in 1% of all patients with retinoblastoma. It usually presents with pseudoinflammatory response in the anterior chamber and the vitreous, masquerading as endophthalmitis or uveitis. This report describes a 12-year-old boy with multiple free-floating intraocular pseudocysts as a unique finding in diffuse infiltrating retinoblastoma. These pseudocysts represent necrotic seeds without epithelial lining. Invasive surgical procedures should be avoided in children presenting with atypical, chronic, unilateral intraocular inflammation of unknown cause until retinoblastoma is excluded.
[J Pediatr Ophthalmol Strabismus 2009;46:312–316.]
New Methods for the Assessment of Accommodative Convergence
Authors: Asakawa Ken , Ishikawa Hitoshi , Shoji Nobuyuki
Published: September 2009

Purpose:

The authors introduced a new objective method for measuring horizontal eye movements based on the first Purkinje image with the use of infrared charge-coupled device (CCD) cameras and compared stimulus accommodative convergence to accommodation (AC/A) ratios as determined by a standard gradient method.

Methods:

The study included 20 patients, 5 to 9 years old, who had intermittent exotropia (10 eyes) and accommodative esotropia (10 eyes). Measurement of horizontal eye movements in millimeters (mm), based on the first Purkinje image, was obtained with a TriIRIS C9000 instrument (Hamamatsu Photonics K.K., Hamamatsu, Japan). The stimulus AC/A ratio was determined with the far gradient method. The average values of horizontal eye movements (mm) and eye deviation (Δ) (a) before and (b) after an accommodative stimulus of 3.00 diopters (D) were calculated with the following formula: horizontal eye movements (mm/D) and stimulus AC/A ratio (Δ/D) = (b – a)/3.

Results:

The average values of the horizontal eye movements and the stimulus AC/A ratio were 0.5 mm/D and 3.8 Δ/D, respectively. Correlation analysis showed a strong positive correlation between these two parameters (r = 0.92). Moreover, horizontal eye movements are directly proportional to the AC/A ratio measured with the gradient method.

Conclusions:

The methods used in this study allow objective recordings of accommodative convergence to be obtained in many clinical situations.

[J Pediatr Ophthalmol Strabismus 2009;46:273–277.]
Pseudopapilledema in Kenny–Caffey Syndrome
Authors: Beral Laurence , Donnio Angélique , Jean-Charles Albert , Merle Harold
Published: September 2009

A 21-year-old man with Kenny–Caffey syndrome had been observed since 1993 for hyperopia. Fundus examination revealed swollen optic disks. Further examinations (fluorescein angiography, B-scan ultrasonography, and optical coherence tomography) confirmed the optic nerve head elevation. The authors report a rare case of Kenny–Caffey syndrome with extreme pseudo-papilledema. Although uncommon, ophthalmologists should be mindful of this disorder when a patient presents with characteristic findings because severe electrolyte disturbances may complicate the clinical course.
The Novel Concurrence of Noonan Syndrome and Bilateral Duane-like Synkinesis
Authors: Kerr Nathan M. , Vincent Andrea L.
Published: September 2009

A 9-year-old boy with Noonan syndrome was referred for evaluation of abnormal eye movements. Ocular motility examination revealed bilateral globe retraction with narrowing of the palpebral fissure in adduction and mild restriction of abduction consistent with a bilateral Duane-like synkinesis. This novel association expands the ocular phenotype of Noonan syndrome and may suggest a commonality in the pathogenesis of these two congenital malformation complexes.
Walker-Warburg Syndrome Manifesting as Leopard Spot Retinopathy, Retinal Detachment, and Microphthalmia
Authors: Park Shin Hae , Shin Sun Young
Published: September 2009

Walker–Warburg syndrome, also known as HARD±E, is a congenital autosomal recessive disorder characterized by hydrocephalus, agyria, and retinal dysplasia, with or without encephalocele. The authors describe an infant with Walker–Warburg syndrome who presented with microphthalmia, retinal detachment, and leopard spot retinopathy.
Place Integration through Daily Activities 1 Year after Stroke
Authors: Erikson Anette , Park Melissa , Tham Kerstin
Published: September 2009

Actions link meaning to particular places over time. This study examined how familiar places, in turn, inspired or influenced actions in the rehabilitation process for individuals who had experienced stroke. The aim of this study was to describe the meanings of actions in different places during 1 year of rehabilitation after stroke. The interview data were longitudinal and collected on four occasions during the first year after stroke (e.g., at 1, 3, 6, and 12 months). Seven categories emerged from the data analysis using a constant comparative method: (1) workplace in mind, (2) experiences at home enabling reflection, (3) rehabilitation setting creates uncertainty, (4) retrieving inspiration from familiar places, (5) matching the complexity of tasks across places, (6) understanding the reality by confrontation, and (7) on the way to place integration. From these themes, a core or overarching theme emerged: the desire for place integration inspires engagement in rehabilitation. The central finding in this study revealed a strong relationship between the desire to be reintegrated into familiar places, such as work and home, and motivation to engage in rehabilitation. Further, this desire for place integration was a constant driving force over the year that motivated the participants to find activities on their own that matched the task demands at their workplaces.
Die ontwikkeling van die menslike bewussyn: Die postmoderne vraag na God
Authors: Ferreira Ignatius W.
Published: September 2009

The development of the human consciousness: The postmodern quest for GodThis article critically reflects upon ‘emerging Christians’ – those who have departed from a premodern (theistic) and modernist (secular) view of reality, and have rather embraced postmodernity in response to the cognitive dissonance they experience due to a clash of epistemological paradigms. The article discusses psychological theories on the development of human consciousness, and describes seven levels or stages of such development, namely the archaic, magical, mythological, rational, pluralistic, holistic and transpersonal levels. The article focuses on Ken Wilber’s integral psychological theory, better known as AQAL (All Quadrants, All Levels and All Lines), which also covers the internal and external dimensions of human consciousness, including an integral view on the so-called ‘states of human consciousness’. In doing so, the article aims to contribute to that aspect of pastoral care that focuses on psychological theory.
Thermal injury in pregnancy: predicting maternal and fetal outcome
Authors: Agarwal P
Published: September 2009

This study was undertaken to assess the parameters that may predict maternal and foetal outcome in 49 thermally injured pregnant women in a Plastic surgery unit in tertiary referral center in the last five years. There were 33 maternal deaths and 34 fetal deaths. In general, pregnancy as such does not influence maternal outcome after thermal injury. In first and second trimester best chance for foetal survival is to ensure maternal survival and in the last trimester fetal survival depends upon fetal maturity. Maternal survival is less likely if the burn wound exceeds 50% total body surface area. Thermal injury does increase the risk of spontaneous abortion and premature labour. Early obstetric intervention is indicated in patients with fatal burn and complications.
Hydroxyapatite/SiO2 Composites via Freeze Casting for Bone Tissue Engineering
Authors: Blindow Silke , Pulkin Maxim , Koch Dietmar , Grathwohl Georg , Rezwan Kurosch
Published: September 2009

Freeze casting is a fabrication method that allows producing near‐net‐shaped ceramics with variable porosity. Hydroxyapatite (HA) was modified by the addition of different amounts of SiO2 nanoparticles during freeze cast preparation. The addition of SiO2 introduced a partial phase transformation of HA to β‐tricalcium phosphate and improved the form stability due to less shrinkage after sintering. The impact of surface roughness of pure HA ceramics and the influence of SiO2 introduction during freeze casting on adhesion, proliferation, and differentiation of human osteoblast‐like cells (MG‐63) was investigated. While both cell attachment and proliferation of smooth pressed HA was significantly enhanced compared to rough freeze cast HA, the addition of SiO2 improved the cell numbers of the latter. The expression of cell differentiation markers osteocalcin and collagen I was found to be supported by rough surfaces (Ra = 5–6 µm) in particular on ceramics containing SiO2
Photoinduced Shuttling Dynamics of Rotaxanes in Viscous Polymer Solutions
Authors: Jagesar Dhiredj C. , Fazio Sandro M. , Taybi Jimmy , Eiser Erika , Gatti Francesco G. , Leigh David A. , Brouwer Albert M.
Published: September 2009

The effect of external friction, caused by medium viscosity, on the photoinduced translational motion in a rotaxane‐based molecular shuttle 1 is investigated. The shuttle is successfully operated in solutions of poly(methacrylonitrile) (PMAN) of different molecular weights in MeCN and PrCN. The viscosity of the medium is tuned by changing the PMAN concentration. The rheological behavior of the polymer solution gives insight into the structure of the polymer solution on the microscopic scale. In PrCN, the entanglement regime is reached at lower concentration than in MeCN. This is also reflected by the effect on the shuttling: in the PrCN/PMAN system, a larger viscosity effect is observed compared to MeCN/PMAN. The shuttle is found to be slowed down in the polymer solutions but is still active at high viscosities. The observed retardation effect on the kinetics of shuttling in MeCN/PMAN and PrCN/PMAN can be correlated to the PMAN concentration through the hydrodynamic scaling model. The Stokes–Einstein relationship proves inadequate to correlate the shuttling rates to macroscopic viscosity, but the dependence of the shuttling rate on the bulk viscosity fits well to a commonly observed power‐law relationship. The viscosity effect on the shuttling is found to be weak in all cases.
Random Copolymer Films with Molecular‐Scale Compositional Heterogeneities that Interfere with Protein Adsorption
Authors: Baxamusa Salmaan H. , Gleason Karen K.
Published: September 2009

Smooth surfaces with compositional heterogeneities at a molecular‐length scale are presented with the goal of disrupting surface–protein interactions. These surfaces are synthesized by utilizing photoinitiated chemical vapor deposition (piCVD) to deposit thin films of random copolymers consisting of highly hydrophilic and highly hydrophobic comonomers. Swellability, wettability, and surface roughness could be systematically controlled by tuning the copolymer composition. The surface composition was dynamic, and the surface reconstructed based on the hydration state of the film. Proteins adsorbed to the copolymer films less readily than to either of the respective homopolymers, indicating a synergistic effect resulting from the random copolymer presenting molecular‐scale compositional heterogeneity. These results provide direct evidence that protein adsorption can be disrupted by such surfaces and a simple analytical model suggests that the heterogeneities occur over areas encompassing 4–5 repeat units of the polymer. The synthetic method used to create these films can be used to coat arbitrary geometries, enabling practical utility in a number of applications.
Anatomical Sciences Education vol.2, issue 5, 2009 cover image
Authors: Evans Darrell J. R. , Cuffe Tracy
Published: September 2009

A near‐peer (NP) teacher discussing structures of the head and neck region with first‐ and second‐year students in the anatomy laboratory at Brighton and Sussex Medical School. NP teachers are fourth‐year medical students who elect to teach in gross anatomy practical classes delivered to first‐ and second‐year medical students. Evans and Cuffe discuss design, implementation and outcomes of the NP teaching program in the current issue of ASE.
Effect of itraconazole on the pharmacokinetics of everolimus administered by different routes in rats
Authors: Yokomasu Akira , Yano Ikuko , Sato Eriko , Masuda Satohiro , Katsura Toshiya , Inui Ken‐ichi
Published: September 2009

The effect of itraconazole on the pharmacokinetics of everolimus was investigated in rats. Ten minutes after an intravenous or intraintestinal administration of itraconazole, everolimus was delivered intravenously (0.2 mg/kg) or intraintestinally (0.5 mg/kg). Blood concentrations of everolimus were measured up to 240 min, and pharmacokinetic parameters were calculated. Intraintestinally administered itraconazole (20 mg/kg) significantly increased the area under the concentration–time curve (AUC) of intraintestinally administered everolimus about 4.5‐fold, but even at 50 mg/kg did not affect theAUCof intravenously administered everolimus. However, intravenously administered itraconazole (50 mg/kg) increased theAUCof both intraintestinally and intravenously administered everolimus approximately 2‐fold. Using a value for hepatic blood flow from the literature (50 ml/min/kg), the apparent intestinal and hepatic extraction of everolimus without itraconazole was calculated as about 80% and 13%, respectively. Intraintestinally administered itraconazole (20 mg/kg) changed the apparent intestinal extraction by 0.26‐fold from 0.829 to 0.215, but the hepatic availability of everolimus was almost unchanged after the intravenous or intraintestinal administration of itraconazole even at a dose of 50 mg/kg from 0.871 to 0.923 or 0.867, respectively. In conclusion, intraintestinally administered itraconazole dramatically increased theAUCof everolimus delivered intraintestinally by inhibiting the intestinal first‐pass extraction of this drug. Copyright © 2009 John Wiley & Sons, Ltd.
Cancer‐associated neochromosomes: a novel mechanism of oncogenesis
Authors: Garsed Dale W. , Holloway Andrew J. , Thomas David M.
Published: September 2009

Malignant tumours are often characterised by significant rearrangement of the genome. This may be visible in the form of a deranged karyotype with both loss and gain of DNA sequences extending from chromosomal regions to whole chromosomes. In several tumour types, however, gross genomic derangements are minimal, and tumour cells contain one or more additional (supernumerary) chromosomes that may be unrecognisable in terms of a single origin. In this review we term such chromosomes cancer‐associated neochromosomes (CaNCs). In the absence of other identified genomic abnormalities, and because the CaNC is a common feature of the cancer type, it is hypothesised that the genetic alterations required for cell transformation are contained within its structure. In this review, we discuss the potential impact of modern genomic technologies on our understanding of the nature and causes of CaNC formation, which is central to several cancer types, exemplified here by well‐differentiated liposarcoma.
Catalytic antibodies: balancing between Dr. Jekyll and Mr. Hyde
Authors: Belogurov Alexey , Kozyr Arina , Ponomarenko Natalia , Gabibov Alexander
Published: September 2009

The immunoglobulin molecule is a perfect template for the de novo generation of biocatalytic functions. Catalytic antibodies, or abzymes, obtained by the structural mimicking of enzyme active sites have been shown to catalyze numerous chemical reactions. Natural enzyme analogs for some of these reactions have not yet been found or possibly do not exist at all. Nowadays, the dramatic breakthrough in antibody engineering and expression technologies has promoted a considerable expansion of immunoglobulin's medical applications and is offering abzymes a unique chance to become a promising source of high‐precision “catalytic vaccines.” At the same time, the discovery of natural abzymes on the background of autoimmune disease revealed their beneficial and pathogenic roles in the disease progression. Thus, the conflicting Dr. Jekyll and Mr. Hyde protective and destructive essences of catalytic antibodies should be carefully considered in the development of therapeutic abzyme applications.
Circadian and solar clocks interact in seasonal flowering
Authors: Yeang Hoong‐Yeet
Published: September 2009

The plant maintains a 24‐h circadian cycle that controls the sequential activation of many physiological and developmental functions. There is empirical evidence suggesting that two types of circadian rhythms exist. Some plant rhythms appear to be set by the light transition at dawn, and are calibrated to circadian (zeitgeber) time, which is measured from sunrise. Other rhythms are set by both dawn and dusk, and are calibrated to solar time that is measured from mid‐day. Rhythms on circadian timing shift seasonally in tandem with the timing of dawn that occurs earlier in summer and later in winter. On the other hand, rhythms set to solar time are maintained independently of the season, the timing of noon being constant year‐round. Various rhythms that run in‐phase and out‐of‐phase with one another seasonally may provide a means to time and induce seasonal events such as flowering.
The granulin gene family: from cancer to dementia
Authors: Bateman Andrew , Bennett Hugh P. J.
Published: September 2009

The growth factor progranulin (PGRN) regulates cell division, survival, and migration. PGRN is an extracellular glycoprotein bearing multiple copies of the cysteine‐rich granulin motif. With PGRN family members in plants and slime mold, it represents one of the most ancient of the extracellular regulatory proteins still extant in modern animals. PRGN has multiple biological roles. It contributes to the regulation of early embryogenesis, to adult tissue repair and inflammation. Elevated PGRN levels often occur in cancers, and PGRN immunotherapy inhibits the growth of hepatic cancer xenografts in mice. Recent studies have demonstrated roles for PGRN in neurobiology. An autosomal dominant mutation in GRN, the gene for PGRN, leads to neuronal atrophy in the frontal and temporal lobes, resulting in the disease frontotemporal lobar dementia. In this review we will discuss current knowledge of the multifaceted biology of PGRN.
Development and validation of a rapid and sensitive HPLC method for the quantification of 5‐fluorocytosine and its metabolites
Authors: Serve Kinta M. , Yáñez Jaime A. , Remsberg Connie M. , Davies Neal M. , Black Margaret E.
Published: September 2009

To study the intracellular metabolism of the prodrug 5‐fluorocytosine (5FC), we developed a novel reverse‐phase high‐performance liquid chromatography method to simultaneously detect 5FC and its four major anabolic metabolites: 5‐fluorouracil, 5‐fluorouridine, 5‐fluorouridine‐monophosphate and 5‐fluoro‐2′deoxyuridine‐5′‐monophosphate. Separation of each compound was accomplished under isocratic conditions using a C18 column and mobile phase of formic acid–water (1 : 99 v/v). The method was validated for both accuracy and reproducibility in cell culture media. Additionally, metabolites were assessed for stability at ambient temperatures and following freeze–thaw cycles. Calibration curves were linear over a range of 1–200 μg/mL. Limit of quantification for four of the five compounds was 1 μg/mL in cell culture media (RSD < 11%). This method was successfully used to monitor intracellular conversion of 5FC to its metabolic products over a 24h period. Copyright © 2009 John Wiley & Sons, Ltd.
On‐line concentration by field‐enhanced sample injection with reverse migrating micelles in micellar electrokinetic capillary chromatography for the analysis of coumarins from traditional Chinese medicine and human serum
Authors: Jiang Ting‐Fu , Lv Zhi‐Hua , Wang Yuan‐Hong , Yue Mei‐E
Published: September 2009

In this work, a simple, reproducible and sensitive micellar electrokinetic chromatography method was developed for the separation and determination of three coumarins, imperatorin (IM), isoimperatorin (IO) and osthole (OS) from traditional Chinese medicine and human serum. Field‐enhanced sample injection with reverse migrating micelles was used for on‐line concentration of the coumarins. The optimum buffer contained 50 mM H3PO4, 160 mM sodium dodecyl sulfate, 20% acetonitrile and 15% 2‐propanol, and the pH of buffer was 2.0. The sample solution was diluted with water containing 5 mM sodium dodecyl sulfate and injected for 15 s with −8 kV after injection of 2 s water plug. The effects of concentrations of sodium dodecyl sulfate and organic modifier, the sample matrix, the injection time of water plug, the injection voltage and injection time of sample on the separation and stacking efficiency were investigated. Under the optimum conditions, the analytes were well separated and by optimizing the stacking conditions, about 93, 195 and 136 fold improvement in the detection sensitivity was obtained for IM, IO and OS. The contents of three coumarins in Angelica dahurica Benth, Radix Angelicae Pubescentis and Fructus Cnidii were successfully determined with satisfactory repeatability and recovery. The possibilities of using this method for the determination of three coumarins in spiked human serum were also tested. Copyright © 2009 John Wiley & Sons, Ltd.
Dynamic cultivation of human mesenchymal stem cells in a rotating bed bioreactor system based on the Z®RP platform
Authors: Diederichs Solvig , Röker Stefanie , Marten Dana , Peterbauer Anja , Scheper Thomas , van Griensven Martijn , Kasper Cornelia
Published: September 2009

Because the regeneration of large bone defects is limited by quantitative restrictions and risks of infections, the development of bioartificial bone substitutes is of great importance. To obtain a three‐dimensional functional tissue‐like graft, static cultivation is inexpedient due to limitations in cell density, nutrition and oxygen support. Dynamic cultivation in a bioreactor system can overcome these restrictions and furthermore provide the possibility to control the environment with regard to pH, oxygen content, and temperature. In this study, a three‐dimensional bone construct was engineered by the use of dynamic bioreactor technology. Human adipose tissue derived mesenchymal stem cells were cultivated on a macroporous zirconium dioxide based ceramic disc called Sponceram®. Furthermore, hydroxyapatite coated Sponceram® was used. The cells were cultivated under dynamic conditions and compared with statically cultivated cells. The differentiation into osteoblasts was initiated by osteogenic supplements. Cellular proliferation during static and dynamic cultivation was compared measuring glucose and lactate concentration. The differentiation process was analysed determining AP‐expression and using different specific staining methods. Our results demonstrate much higher proliferation rates during dynamic conditions in the bioreactor system compared to static cultivation measured by glucose consumption and lactate production. Cell densities on the scaffolds indicated higher proliferation on native Sponceram® compared to hydroxyapatite coated Sponceram®. With this study, we present an excellent method to enhance cellular proliferation and bone lineage specific growth of tissue like structures comprising fibrous (collagen) and globular (mineral) extracellular components. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Superior outcome with hypomethylating therapy in patients with acute myeloid leukemia and high‐risk myelodysplastic syndrome and chromosome 5 and 7 abnormalities
Authors: Ravandi Farhad , Issa Jean‐Pierre , Garcia‐Manero Guillermo , O'Brien Susan , Pierce Sherry , Shan Jianqin , Borthakur Gautam , Verstovsek Srdan , Faderl Stefan , Cortes Jorge , Kantarjian Hagop
Published: September 2009

BACKGROUND:

Outcome of patients with acute myeloid leukemia (AML) and high‐risk myelodysplastic syndrome (MDS) with chromosome 5 and 7 abnormalities (excluding del 5[q]) has been poor, with <10% of patients alive at 2 years.

METHODS:

The authors investigated whether treatment with hypomethylating agents (5‐azacytidine/decitabine) leads to an improved outcome. Between January 2004 and December 2007, 81 patients (37 [46%] with AML [≥20% blasts]; 44 [54%] with high‐risk MDS) with chromosome 5 and 7 abnormalities were treated with hypomethylating agents as their initial therapy. These included 68 patients with complex (≥3) abnormalities and 13 with <3 aberrations. During the same period, 151 patients (126 with AML, 25 with MDS) with chromosome 5 and 7 abnormalities (128 complex, 23 noncomplex) were treated with intensive chemotherapy (including cytarabine‐based regimens in 72% and other regimes in 28%).

RESULTS:

The median ages for the 2 groups were 66 years and 61 years, respectively (ranges, 37‐85 years and 19‐89 years). Thirty‐three (41%) patients in the hypomethylating group achieved complete remission (CR) versus 53 (35%) in the chemotherapy group (P = .395). With a median follow‐up of 51 weeks (range, 12‐101 weeks) and 40 weeks (range, 5–128 weeks), 22 of 33 patients in the hypomethylating group and 33 of 53 patients in the chemotherapy group had developed disease recurrence. The median CR duration was 45 weeks and 23 weeks, respectively (P = .153). The overall survival was superior for the hypomethylating group compared with the chemotherapy group (P = .019).

CONCLUSIONS:

Treatment with hypomethylating agents may be superior to chemotherapy in patients with chromosome 5 and 7 abnormalities. Cancer 2009. © 2009 American Cancer Society.
Selective projection patterns from subtypes of retinal ganglion cells to tectum and pretectum: Distribution and relation to behavior
Authors: Jones Marcus Robert , Grillner Sten , Robertson Brita
Published: September 2009

An important issue to understand is how visual information can influence the motor system and affect behavior. Using the lamprey (Petromyzon marinus) as an experimental model we examined the morphological subtypes of retinal ganglion cells and their projection pattern to the tectum, which controls eye, head, and body movements, and to the pretectum, which mediates both visual escape responses and the dorsal light response. We identified six distinct morphological types of retinal ganglion cell. Four of these distribute their dendrites in the inner plexiform layer (image forming layer) and project in a retinotopic manner to all areas of the tectum. The posterior part of the retina has the highest density of ganglion cells and projects to the rostral part of the tectum, in which the visual field in front of the lamprey will be represented. From this area both orienting and evasive behaviors can be elicited. In contrast, pretectum receives input from two ganglion cells types that send their dendrites only to the outer plexiform layer or the outer limiting membrane and therefore may directly contact photoreceptors, and transmit information without additional delay to pretectum, which may be particularly important for visual escape responses. One of these two types, the bipolar ganglion cell, is only found in a small patch of retina just ventral of the optic nerve. Due to its distribution, morphology, and projections we suggest that this cell may control the dorsal light response. J. Comp. Neurol. 517:257–275, 2009. © 2009 Wiley‐Liss, Inc.