bluuebunny/crossref_metadata_2025 huggingface dataset:
Parkinson's disease and healthy aging: Independent and interacting effects on action selection
Authors: Hughes Laura E. , Barker Roger A. , Owen Adrian M. , Rowe James B.
Published: February 2010

Functional reorganization of the motor system occurs in response to both aging and Parkinson's disease (PD). Since PD typically develops in older adults, disease progression and the effects of treatment may interact with normal aging. Using event‐related functional magnetic resonance imaging, we studied patients “on” and “off” their normal dopaminergic medication, age‐matched controls and younger adults on tasks of action and action selection. For manual movements, aging increased activity in bilateral motor, premotor and cingulate cortex. Activation in the premotor regions of “on” patients was higher relative to age‐matched controls. However, in contrast to controls and “off” patients, the activations for patients when “on” decreased with age. Voluntary selection of actions was associated with activation in a bilateral network of fronto‐parietal cortex. Within this network, advancing severity of PD was associated with decreased activity particularly in premotor and ventrolateral prefrontal cortex. Together, these results reveal very different patterns of age‐related changes in health and PD. Younger patients are able to exert greater compensatory activity in premotor cortex than older patients, even after correction for disease severity. This effect is dopamine dependant, and may in part explain the clinical observation of reduced dopamine responsiveness in older patients with PD. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Cancer incidence in a rural population of South Africa, 1998–2002
Authors: Somdyala Nontuthuzelo IM , Bradshaw Debbie , Gelderblom Wentzel CA , Parkin Donald M
Published: February 2010

Cancer incidence rates and patterns are reported for a rural population, living in the Eastern Cape Province of South Africa for the period 1998–2002. The population‐based cancer registry has operated for 20 years, using both active and passive methods for case finding, through collaborations with 19 health facilities: 11 district hospitals, 7 referral hospitals and 1 regional laboratory. The age standardized incidence rates for all cancers were 73.1 per 100,000 in males and 64.1 per 100,000 in females. The leading top 5 cancers for males were oesophagus (32.7 per 100,000), lung (5.8 per 100,000), prostate (4.4 per 100,000), liver (4.4 per 100,000) and larynx (2.5 per 100,000) whereas for females they were cervix (21.7 per 100,000), oesophagus (20.2 per 100,000), breast (7.5 per 100,000), ovary (0.9 per 100,000) and liver (0.9 per 100,000). The incidence of Kaposi sarcoma was low, and higher for males (1.6 per 100,000) than females (0.3 per 100,000). Lung cancer in both males and females was relatively low compared to the high incidence of oesophagus cancer.
Endothelial‐like cells derived directly from human tumor xenografts
Authors: Sajithlal Gangadharan B. , McGuire Terence F. , Lu Jie , Beer‐Stolz Donna , Prochownik Edward V.
Published: February 2010

Tumor‐associated endothelial cells (TAECs) harboring various genomic abnormalities have been described in human cancers although their origins remain obscure. We generated 4 human cancer cell lines tagged with multiple markers, grew them as xenografts, and characterized their TAECs. Depending on their tumor of origin, 5–40% of TAECs reproducibly expressed all tags. Tagged TAECs (tTAECS) were morphologically, immunologically and functionally similar, although not identical, to normal endothelial cells (ECs) and contained only human chromosomes. tTAECs underwent a senescent‐like proliferative arrest after several in vitro passages, but could be immortalized by telomerase, thus allowing us to show that the retention of the EC phenotype was of long‐term duration. In contrast, nonimmortalized tTAECs could be propagated in vivo where they incorporated into the tumor neo‐vasculature. Although consistent with previous reports that some tumor cells may undergo “vasculogenic mimicry” (VM), the tumor‐derived endothelial‐like cells described here appear distinctly different. Moreover, their properties and behaviors are more durable than expected for cells undergoing VM, are not the result of fusions between ECs and tumor cells, and are cell autonomous. These findings could have significant implications for therapies that target tumor angiogenesis.
Colon cancer in Iceland—A nationwide comparative study on various pathology parameters with respect to right and left tumor location and patients age
Authors: Snaebjornsson Petur , Jonasson Larus , Jonsson Thorvaldur , Möller Pall Helgi , Theodors Asgeir , Jonasson Jon G.
Published: February 2010

Increasing evidence suggests genetic, biological and demographical difference between right and left colon cancer. Studies have also indicated age differences in the pathology of colon cancer. There is a scarcity of large‐scale studies that closely examine the pathological differences regarding age and tumor location. The aim of our study was to do an extensive comparison of right‐ and left‐ sided colon cancers as well as comparing patients <50 years with older patients. A retrospective, population‐based study was carried out on all patients with colon cancer in Iceland between 1955 and 2004. A total of 2293 cases were analyzed (1148 men, 1145 women). All histopathology material was re‐evaluated. Differences in tumor characteristics between right and left location and younger (<50) and older (≥50) patients was evaluated in particular. Higher TNM‐stage, larger tumors, vessel invasion, mucinous type, high grade and expanding tumor border occurred more frequently in right‐ versus left‐sided lesions while annular and polypoid tumors were more common in left‐sided tumors (p < 0.05). Young patients had more frequent lymph node metastases, vessel invasion, nonpolypoid lesions and infiltrating tumor border (p < 0.05). Right‐sided lesions show more aggressive features, reflected in morphology and stage. Younger patients present more frequently with adverse features than do older patients. Frequency of right‐ and left‐sided colon cancer differs by age with pronounced age‐location differences in females. This supports the assumption of differences in etiology and carcinogenesis of right‐ and left‐sided colon cancer, and between young and old patients.
The effect of GHRH antagonists on human glioblastomas and their mechanism of action
Authors: Pozsgai Eva , Schally Andrew V. , Zarandi Marta , Varga Jozsef L. , Vidaurre Irving , Bellyei Szabolcs
Published: February 2010

The effects of new growth hormone‐releasing hormone (GHRH) antagonists JMR‐132 and MIA‐602 and their mechanism of action were investigated on 2 human glioblastoma cell lines, DBTRG‐05 and U‐87MG, in vitro and in vivo. GHRH receptors and their main splice variant, SV1 were found on both cell lines. After treatment with JMR‐132 or MIA‐602, the cell viability decreased significantly. A major decrease in the levels of phospho‐Akt, phospho‐GSK3β and phosho‐ERK 1/2 was detected at 5 and 10 min following treatment with the GHRH antagonists, whereas elevated levels of phospho‐p38 were observed at 24 hr. The expression of caspase‐3 and poly(ADP‐ribose) (PARP), as the downstream executioners of apoptosis were found to be significantly elevated after treatment. Following treatment of the glioblastoma cells with GHRH antagonists, nuclear translocation of apoptosis inducing factor (AIF) and Endonuclease G (Endo G) and the mitochondrial release of cytochrome c (cyt c) were detected, indicating that the cells were undergoing apoptosis. In cells treated with GHRH antagonists, the collapse of the mitochondrial membrane potential was shown with fluorescence microscopy and JC‐1 membrane potential sensitive dye. There were no significant differences between results obtained in DBTRG‐05 or U‐87MG cell lines. After treatment with MIA‐602 and JMR‐132, the reduction rate in the growth of DBTRG‐05 glioblastoma, xenografted into nude mice, was significant and tumor doubling time was also significantly extended when compared with controls. Our study demonstrates that GHRH antagonists induce apoptosis through key proapoptotic pathways and shows the efficacy of MIA‐602 for experimental treatment of glioblastoma.
Site‐specific opening of the blood‐brain barrier
Authors: Madsen Steen J. , Hirschberg Henry
Published: February 2010

The blood‐brain barrier (BBB) poses a significant impediment for the delivery of therapeutic drugs into the brain. This is particularly problematic for the treatment of malignant gliomas which are characterized by diffuse infiltration of tumor cells into normal brain where they are protected by a patent BBB. Selective disruption of the BBB, followed by administration of anti‐cancer agents, represents a promising approach for the elimination of infiltrating glioma cells. A summary of the techniques (focused ultrasound, photodynamic therapy and photochemical internalization) for site‐specific opening of the BBB will be discussed in this review. Each approach is capable of causing localized and transient opening of the BBB with minimal damage to surrounding normal brain as evidenced from magnetic resonance images and histology. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differential expression and cellular distribution of γ‐tubulin and βIII‐tubulin in medulloblastomas and human medulloblastoma cell lines
Authors: Caracciolo Valentina , D'agostino Luca , Dráberová Eduarda , Sládková Vladimíra , Crozier‐Fitzgerald Catena , Agamanolis Dimitri P. , de Chadarévian Jean‐Pierre , Legido Agustin , Giordano Antonio , Dráber Pavel , Katsetos Christos D.
Published: February 2010

In previous studies, we have shown overexpression and ectopic subcellular distribution of γ‐tubulin and βIII‐tubulin in human glioblastomas and glioblastoma cell lines (Katsetos et al., 2006, J Neuropathol Exp Neurol 65:455–467; Katsetos et al., 2007, Neurochem Res 32:1387–1398). Here we determined the expression of γ‐tubulin in surgically excised medulloblastomas (n = 20) and in the human medulloblastoma cell lines D283 Med and DAOY. In clinical tissue samples, the immunohistochemical distribution of γ‐tubulin labeling was pervasive and inversely related to neuritogenesis. Overexpression of γ‐tubulin was widespread in poorly differentiated, proliferating tumor cells but was significantly diminished in quiescent differentiating tumor cells undergoing neuritogenesis, highlighted by βIII‐tubulin immunolabeling. By quantitative real‐time PCR, γ‐tubulin transcripts for TUBG1, TUBG2, and TUBB3 genes were detected in both cell lines but expression was less prominent when compared with the human glioblastoma cell lines. Immunoblotting revealed comparable amounts of γ‐tubulin and βIII‐tubulin in different phases of cell cycle; however, a larger amount of γ‐tubulin was detected in D283 Med when compared with DAOY cells. Interphase D283 Med cells exhibited predominantly diffuse cytoplasmic γ‐tubulin localization, in addition to the expected centrosome‐associated distribution. Robust βIII‐tubulin immunoreactivity was detected in mitotic spindles of DAOY cells. Our data indicate that overexpression of γ‐tubulin may be linked to phenotypic dedifferentiation (anaplasia) and tumor progression in medulloblastomas and may potentially serve as a promising tumor marker. J. Cell. Physiol. 223: 519–529, 2010. © 2010 Wiley‐Liss, Inc.
Temperature and equivalent temperature over the United States (1979–2005)
Authors: Fall Souleymane , Diffenbaugh Noah S. , Niyogi Dev , Pielke Roger A. , Rochon Gilbert
Published: February 2010

Temperature (T) and equivalent temperature (TE) trends over the United States from 1979 to 2005 and their correlation to land cover types are investigated using National Centers for Environmental Prediction North American Regional Reanalysis data, the Advanced Very High Resolution Radiometer (AVHRR) land use/cover classification, the National Land Cover Database (NLCD) 1992–2001 Retrofit Land Cover Change and the Normalised Difference Vegetation Index (NDVI) derived from AVHRR. Even though most of the magnitude of TE is explained by T, the moisture component induces larger trends and variability of TE relative to T. The contrast between pronounced temporal and spatial differences between T and TE at the near‐surface level (2 m) and minor‐to‐no differences at 300–200 mb is a consistent pattern. This study therefore demonstrates that in addition to temperature, atmospheric heat content may help to quantify the differences between surface and tropospheric heating trends, and hence the impact of land cover types on the surface temperature changes. Correlations of T and TE with NDVI reveal that TE shows a stronger relationship to vegetation cover than T, especially during the growing season, with values that are significantly different and of opposite signs (−0.31 for T vs NDVI; 0.49 for TE vs NDVI). Our results suggest that land cover types influence both moisture availability and temperature in the lower atmosphere and that TE is larger in areas with higher physical evaporation and transpiration rates. As a result, TE can be used as an additional metric for analysing near‐surface heating trends with respect to land cover types. Moreover, TE can be tested as a complementary variable for assessing the impact of land surface and boundary layer processes in re‐analysis and weather/climate model studies. Copyright © 2010 Royal Meteorological Society
Influence of bone density on the cement fixation of femoral hip resurfacing components
Authors: Bitsch Rudi G. , Jäger Sebastian , Lürssen Marcus , Loidolt Travis , Schmalzried Thomas P. , Clarius Michael
Published: February 2010

In clinical outcome studies, small component sizes, female gender, femoral shape, focal bone defects, bad bone quality, and biomechanics have been associated with failures of resurfacing arthroplasties. We used a well‐established experimental setup and human bone specimens to analyze the effects of bone density on cement fixation of femoral hip resurfacing components. Thirty‐one fresh frozen femora were prepared for resurfacing using the original instruments. ASR™ resurfacing prostheses were implanted after dual‐energy X‐ray densitometer scans. Real‐time measurements of pressure and temperature during implantation, analyses of cement penetration, and measurements of micro motions under torque application were performed. The associations of bone density and measurement data were examined calculating regression lines and multiple correlation coefficients; acceptability was tested with ANOVA. We found significant relations between bone density and micro motion, cement penetration, cement mantle thickness, cement pressure, and interface temperature. Mean bone density of the femora was 0.82 ± 0.13 g/cm2, t‐score was −0.7 ± 1.0, and mean micro motion between bone and femoral resurfacing component was 17.5 ± 9.1 µm/Nm. The regression line between bone density and micro motion was equal to −56.7 ×  bone density + 63.8, R = 0.815 (p < 0.001). Bone density scans are most helpful for patient selection in hip resurfacing, and a better bone quality leads to higher initial component stability. A sophisticated cementing technique is recommended to avoid vigorous impaction and incomplete seating, since increasing bone density also results in higher cement pressures, lower cement penetration, lower interface temperatures, and thicker cement mantles. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:986–991, 2010
Determination of thermodynamic parameters in reversed phase chromatography for polyethylene glycols and their methyl ethers in different mobile phases
Authors: Nguyen Viet Cuong , Trathnigg Bernd
Published: February 2010

The thermodynamic parameters (entropy and enthalpy change) and their increment per repeat unit have been determined in RP chromatography of PEG and its mono‐ and dimethyl ethers in different mobile phases. The different approaches for their determination and the problems related to the characteristic volumes (void volume, interstitial volume, pore volume) of the column are discussed. Very different dependences or the thermodynamic parameters were observed in aqueous mobile phases containing ACN, acetone, or methanol as organic modifier. In the first two mobile phases a linear dependence on the number of repeat units n is found, and the additional entropy and enthalpy changes per repeat unit are positive. In methanol–water, the enthalpy change is negative with a non‐linear dependence on n, and the entropy change is independent on n and close to zero. The contribution of the end groups is almost the same in the first two mobile phases, but much smaller in methanol–water.
A web‐based method for rating facial attractiveness
Authors: Devcic Zlatko , Karimi Koohyar , Popenko Natalie , Wong Brian J.F.
Published: February 2010

Objectives/Hypothesis:

To determine if facial attractiveness scores from a novel Internet‐based facial attractiveness rating method correlate with those from the traditional focus group rating method, and whether this method can be an alternative for rating and evaluating facial attractiveness.

Study Design:

Basic research study.

Methods:

Eighty facial portraits were posted on a commercial Internet‐based facial rating website to obtain facial attractiveness scores. These scores were correlated and compared with traditional focus group scores.

Results:

In 21 days an average sample size of 857 raters were recruited and the attractiveness scores reached a stable mean on the Web. There was a strong correlation (0.90) and attractiveness score quartile match between the Internet‐based and traditional focus group scores, with the most attractive and unattractive faces having the highest correlation and quartile match. The inter‐rater variability of the Internet‐based method was low (P = .82).

Conclusions:

The Internet‐based method can be an effective alternative to the traditional live focus group method of evaluating facial attractiveness. It also has five main advantages: 1) profoundly increases rater count; 2) increases rate of data accrual and analysis; 3) results are reproducible; 4) eliminates logistical and monetary obstacles; and 5) enables the experimenter to sweep broad demographics, acquire background data from raters, and locate raters with specific expertise. Laryngoscope, 2010
Effect of neural‐induced mesenchymal stem cells and platelet‐rich plasma on facial nerve regeneration in an acute nerve injury model
Authors: Cho Hyong‐Ho , Jang Sujeong , Lee Sang‐Chul , Jeong Han‐Seong , Park Jong‐Seong , Han Jae‐Young , Lee Kyung‐Hwa , Cho Yong‐Bum
Published: February 2010

Objectives/Hypothesis:

The purpose of this study was to investigate the effects of platelet‐rich plasma (PRP) and neural‐induced human mesenchymal stem cells (nMSCs) on axonal regeneration from a facial nerve axotomy injury in a guinea pig model.

Study Design:

Prospective, controlled animal study.

Methods:

Experiments involved the transection and repair of the facial nerve in 24 albino guinea pigs. Four groups were created based on the method of repair: suture only (group I, control group); PRP with suture (group II); nMSCs with suture (group III); and PRP and nMSCs with suture (group IV). Each method of repair was applied immediately after nerve transection. The outcomes measured were: 1) functional outcome measurement (vibrissae and eyelid closure movements); 2) electrophysiologic evaluation; 3) neurotrophic factors assay; and 4) histologic evaluation.

Results:

With respect to the functional outcome measurement, the functional outcomes improved after transection and reanastomosis in all groups. The control group was the slowest to demonstrate recovery of movement after transection and reanastomosis. The other three groups (groups II, III, and IV) had significant improvement in function compared to the control group 4 weeks after surgery (P < .05). On the electrophysiologic evaluation, there was significantly better performances in groups II, III, and IV when compared to group I with respect to the amplitude and excitation area of the compound motor action potentials (MAPs) 4 and 6 weeks after surgery (P < .05); group IV had the best performance. A Western blot assay showed that group II had marked expression of several neurotrophic factors. Groups II, III, and IV demonstrated better results in axon counts and myelin thickness when compared with group I. Based on quantitative histology analysis, group IV had the greatest myelinated axon fibers compared to the other groups (P < .05).

Conclusions:

The use of PRP and/or nMSCs promotes facial nerve regeneration in an animal model of facial nerve axotomy. The use of nMSCs showed no benefit over the use of PRP in facial nerve regeneration, but the combined use of PRP and nMSCs showed a greater beneficial effect than use of either alone. This study provides evidence for the potential clinical application of PRP and nMSCs in peripheral nerve regeneration of an acute nerve injury. Laryngoscope, 2010
New Composite Elastomers with Giant Magnetic Response
Authors: Chertovich A. V. , Stepanov G. V. , Kramarenko E. Yu. , Khokhlov A. R.
Published: February 2010

Novel magnetorheological elastomers (MRE) based on a highly elastic silicone rubber filled with carbonyl iron magnetic particles of 3–5 and 3–50 µm are synthesized. The effect of an external homogeneous magnetic field on the viscoelastic properties of these materials is studied by dynamic experiments (shear oscillations on a rheometer). It is shown that the magnetic response of the MRE increases with a decrease of the strain. At 1% deformation both the storage and loss moduli of the new MRE demonstrate a giant response to the magnetic field, namely, an increase of more than two orders of magnitude in both moduli in a field of 300 mT is observed. In addition, these new MREs show a twofold increase of the damping ratio, which is important for their application as tunable vibration absorbers.

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Synthesis of Organosilica Films Through Consecutive Sol/Gel Process and Cationic Photopolymerization
Authors: Versace Davy‐Louis , Chemtob Abraham , Croutxé‐Barghorn Céline , Rigolet Séverinne
Published: February 2010

The cationic photopolymerization of epoxy polysilsesquioxane resins synthesized through a acid‐catalyzed sol/gel process is studied. To elucidate the effect of the organic substituent on sol/gel reaction kinetics, two organotrimethoxysilanes with different organic groups were employed. Effects of UV irradiation on the microstructure of the epoxy‐functional polysilsesquioxanes were also studied. 29Si solid‐state MAS NMR proved that UV‐generated Brönsted acids favored a work‐up of the silicate network by promoting new sol/gel condensation reactions. There was a significant slowdown of epoxy conversion rates with increasing sol aging, which may be due to a competition between an active chain end and an activated monomer mechanism for the epoxy cationic polymerization.

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H–Si Functionalized Silicon Surfaces and Powders as Photoinitiators of Polymerization
Authors: Souane Rachid , Lalevée Jacques , Allonas Xavier , Fouassier Jean‐Pierre
Published: February 2010

Nowadays, silicon represents the most important material used for microelectronic applications. In this paper, both H–Si (111) surfaces and H–Si powders are used to initiate a multifunctional acrylate photopolymerization. The polymers formed are characterized by IR spectroscopy. This should be the way to create either an acrylate polymer coating on a Si wafer or a polymer film containing covalently linked silicon particles.

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Modeling of Sequence Length and Distribution for the NM‐CRP of Styrene and 4‐Methylstyrene in Batch and Semi‐Batch Reactors
Authors: Ye Yuesheng , Schork F. Joseph
Published: February 2010

A chain model and a sequence model were developed to describe chain and sequence properties for the NM‐CRP of styrene and 4‐methylstyrene in both batch and semi‐batch reactors. The capability of a sequence model to model sequence length and distributions in the course of different processes is demonstrated. The model can also be applied to a Con‐FRP process. Simulation shows a good agreement with experimental data reported in literature. Simulation results indicate that the sequence properties of copolymers prepared by a Con‐FRP process and by an NM‐CRP process can be very similar, but the chain properties are far different. The sequence model can serve as a theoretical tool to understand the importance of sequence length and distributions in radical copolymerization processes.

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Measuring sensory nerve action potential electrical power
Authors: Roberts Niles M. , Wertsch Jacqueline J.
Published: February 2010

Sensory nerve action potential (SNAP) amplitudes are frequently examined for evidence of axonal loss. Because digital nerves have parallel fibers, and parallel voltages do not add, SNAP amplitude may not accurately reflect axonal loss. In contrast, electrical power can be measured for digital nerves, and is additive. In this study we explore the ability of SNAP electrical power (SELP) to discriminate the increased number of axons in fingers with two median digital nerves versus fingers with only one median digital nerve. Antidromic SNAP amplitudes and SELPs were obtained for 15 fingers. Seventeen external resistors, Rext, were sequentially connected from electrode to ground for SELP determination. The resulting bell‐shaped power vs. Rext plot was regressed to the power transfer equation, which has a peak that defines SELP. SELPs of two‐digital‐nerve (median) fingers were 360–670 femtowatts (mean 525 fW). For one‐digital‐nerve fingers, SELP was 90–230 fW (mean 190 fW). Evaluation of one‐ vs. two‐median‐digital‐nerve statistics showed the SNAP amplitude difference‐of‐means to be insignificant, whereas the SELP difference‐of‐means was 3.3 SD (P < 0.01). Using a criterion of 2 SDs, SNAP amplitude did not discriminate any one‐median‐digital‐nerve fingers, whereas SELP discriminated all with no false positives. Because parallel voltages do not add, SNAP amplitudes may not reflect axonal loss. In contrast, electrical power is additive. We describe the SELP technique and demonstrate its ability to discriminate different numbers of axons as reflected by one digital nerve vs. two digital nerves. Muscle Nerve 41: 318–323, 2010
Immunisation practices of paediatric oncology and shared care oncology consultants: A United Kingdom survey
Authors: Bate Jessica , Patel Soonie R. , Chisholm Julia , Heath Paul T.
Published: February 2010

Background

In March 2002, the Royal College of Paediatrics and Child Health (RCPCH) introduced guidelines for re‐immunisation of children after completion of standard‐dose chemotherapy and after haematopoietic stem cell transplant (HSCT).

Aims

To ascertain whether these guidelines form standard unit policy by undertaking a survey of UK paediatric principal treatment centre (PTC) consultants and shared care (SC) consultants.

Procedures

In October 2008, a link to an on‐line anonymised survey was sent by e‐mail to all UK PTC consultants in Children's Cancer and Leukaemia Group (CCLG) centres and to SC consultants linked to eight of these centres.

Results

Responses were received from 55 PTC consultants (representing all 21 CCLG centres) and 54 SC consultants. In accordance with the RCPCH guidelines, most PTC and SC consultants recommend initiating re‐immunisation at 6 months after completion of standard‐dose chemotherapy (99/105, 94.3%). Re‐immunisation at the recommended time after HSCT for each transplant type was reported by 93–100% of respondents. Pneumococcal conjugate vaccine (PCV) was recommended after chemotherapy by 58.3% (35/60) of respondents and by 51.7% (30/58) after HSCT. There were distinct differences between PTC and SC consultants in their choice of varicella (VZV) post‐exposure prophylaxis.

Conclusions

There is a high level of stated compliance with RCPCH guidelines. Recommendations for PCV after chemotherapy and HSCT were lower than expected. This may reflect the absence of specific guidelines after chemotherapy but not in HSCT patients where guidelines do exist. Variation in VZV post‐exposure prophylaxis suggests further studies are required. Pediatr Blood Cancer 2010;54:941–946 © 2010 Wiley‐Liss, Inc.
Groshong catheter‐related complications in children with cancer
Authors: Ruggiero Antonio , Barone Giuseppe , Margani Gabriella , Nanni Lorenzo , Pittiruti Mauro , Riccardi Riccardo
Published: February 2010

Background

Children with cancer undergo intensive treatments requiring reliable vascular access. Central venous catheters (CVCs) reduce discomfort due to venipuncture and the risks of extravasations from chemotherapy administration. The aim of our retrospective study was to assess safety and complications of Groshong devices in children with cancer.

Patients and Methods

One hundred ninety Groshong CVCs were placed in 166 children over a 5‐year period. Early complications, and infectious and mechanical events were collected.

Results

The mean period of permanence of the CVCs was 330 days per patient (range 7–1,037). Of the febrile episodes, 36 (34.6%) were CVC‐related, with an incidence rate of 0.56 per 1,000 CVC days. Severe neutropenia conditions most of all complicated CVC‐related infectious events (94.4%) and Gram‐negative bacteria were those most often isolated (55%). Twenty CVCs were affected by mechanical or thrombotic complications, with an incidence of 0.33 episodes per 1,000 CVC days. Mechanical complications led to CVC removal in 6 (3.1%) cases, while CVC‐related infective episodes were responsible for 10 (5.2%) CVC removals.

Conclusions

The long in situ duration of this device allowed it to be safely employed from the beginning to the end of the treatment period in most children. Pediatr Blood Cancer 2010;54:947–951 © 2010 Wiley‐Liss, Inc.
Orbital sarcoma with metastases at diagnosis: A report from the soft tissue sarcoma committee of the Children's Oncology Group
Authors: Huh Winston W. , Anderson James R. , Rodeberg David , Teot Lisa , Yock Torunn , Raney R. Beverly
Published: February 2010

We reviewed clinicopathologic features and treatment outcomes in seven patients diagnosed with Stage 4/Group IV orbital sarcoma and treated on IRSG protocols I–III. Three patients had embryonal rhabdomyosarcoma (RMS), and two patients each had alveolar RMS or unclassified sarcoma. Median age at diagnosis was 1.8 years (range 0.2–6.9 years). All patients had bone marrow involvement, including six with normal complete blood count at diagnosis. Cerebrospinal fluid was normal in six patients. Three patients survived >5 years, including one with local recurrence. In conclusion, further study is needed to determine necessity of bone marrow and CSF examination in orbital sarcoma patients. Pediatr Blood Cancer 2010;54:1045–1047 © 2010 Wiley‐Liss, Inc.
A composite pheochromocytoma/ganglioneuroblastoma of the adrenal gland
Authors: Thiel Elizabeth Lee , Trost Beth A. , Tower Richard L.
Published: February 2010

A 9‐year‐old female presented with a large abdominal mass. At surgery, the mass was noted to arise from the right adrenal gland. As the mass was manipulated, the patient developed severe hypertension. The final diagnosis was a cystic composite‐pheochromocytoma/ganglioneuroblastoma. This compound adrenal tumor is only the fourth case reported in a child. Because composite pheochromocytomas are rare in the pediatric population, the management, optimal surveillance schedule and outcomes have not been characterized. Pediatr Blood Cancer 2010;54:1032–1034 © 2010 Wiley‐Liss, Inc.
Effect of different types of peroxides on properties of vulcanized EPDM + PP blends
Authors: Brostow Witold , Datashvili Tea , Hackenberg Ken P.
Published: February 2010

Mechanical and tribological behavior of several dynamic vulcanizate blends of polypropylene (PP) with ethylene‐propylene‐diene rubber (EPDM) was examined and compared with those of uncrosslinked blends. Vulcanization was performed using two types of organic peroxides combined with (meth)acrylate coagent. The effect of different types and concentrations of peroxides as crosslinking agents on the properties of the resulting materials were investigated. Dicumyl peroxide (DCP) provides higher reactivity and exhibits nearly the same crosslinking efficiency for both 60/40 and 50/50 blends; almost fully crosslinked samples are obtained if the compound contains 1.0 or 2.0 wt% DCP. These results correlate to the gel content and mechanical properties of our materials. Variation of PP + elastomer ratio does not have a significant influence on friction. From 60/40 group of composites, lower friction values were obtained for samples cured with 0.5 wt% benzoyl peroxide (BP) and 1.0 wt% DCP. The tribological properties of the samples with higher amount of DCP show rubbery rather than a toughened thermoplastic behavior. Wear of the composites decreases with the increasing concentration of the curing agent. Compared to BP, the samples cured with DCP display lower wear. POLYM. COMPOS., 31:1678–1691, 2010. © 2010 Society of Plastics Engineers.
Use of Turkish huntite/hydromagnesite mineral in plastic materials as a flame retardant
Authors: Atay Hüsnügül Yılmaz , Çelik Erdal
Published: February 2010

In this study, the flame retardancy properties of huntite/hydromagnesite mineral in plastic compounds were investigated for potential electrical applications. Before the production of composite materials, huntite/hydromagnesite minerals were ground to particle sizes of 10, 1, and 0.1 μm. Phase and microstructural analysis of huntite/hydromagnesite mineral powders were undertaken using XRD and SEM‐EDS preceding the fabrication of the composite materials. The ground minerals with different particle size and content levels were subsequently added to ethylene vinyl acetate copolymer to produce composite materials. After fabrication of huntite/hydromagnesite reinforced plastic composite samples, they were characterized using DTA‐TG, FTIR, and SEM‐EDS. Flame retardancy tests were undertaken as a main objective of this research. The size distribution and the mineral content effects are measured regarding the flame retardancy of the polymer composites It was concluded that the flame retardant properties of plastic composites were improved as the mineral content increased and the size was reduced. POLYM. COMPOS., 31:1692–1700, 2010. © 2010 Society of Plastics Engineers.
Polymer‐induced improvements in ferroelectric liquid crystal
Authors: Manohar Rajiv , Misra Abhishek Kumar , Srivastava Abhishek Kumar
Published: February 2010

The chevron geometry in the SmC* phase of ferroelectric liquid crystals (FLC) has been a major obstacle in the use of FLC in displays as it results in poor electro‐optical performance. The present paper reports a novel method to overcome this problem, by doping a small amount of polymer in the FLC matrix. In addition to the improvement in smectic ordering, polymer doping is also found to be useful in improving the vital electro‐optical properties. The various electro‐optical parameters like switching time, tilt angle, contrast ratio etc. show improvement in polymer mixed guest host mixture of FLC samples. POLYM. COMPOS., 31:1776–1781, 2010. © 2010 Society of Plastics Engineers.
A simple and efficient frit preparation method for one‐end tapered‐fused silica‐packed capillary columns in nano‐LC‐ESI MS
Authors: Tan Feng , Chen Shuo , Zhang Yangjun , Cai Yun , Qian Xiaohong
Published: February 2010

A novel frit preparation method for one‐end tapered‐fused silica‐packed capillary columns in nano‐LC‐ESI MS was developed. A hollow‐fused silica capillary column with a tapered tip as nano‐spray emitter was filled with 5 μm C18 beads, and then a sintered frit about 0.25 mm in length was prepared at the tip by butane flame. A stainless steel protection tube with 0.5 mm id was used to control the length of the frit and to protect the packed C18 beads behind the sintered frit during the sintering. C18 sintered frits were evaluated by BSA tryptic digests with nano‐LC‐LTQ. The sintered frits did not produce post‐column band broadening due to very small volume (about 0.2 nL) and did not produce adsorption to sample. The sintered frit columns had good separation reproducibility and separation performance compared with self‐assembled particles frit columns and commercial columns.
Vision for mental health needs financial commitment
Authors: Titmarsh Steve
Published: February 2010

New Horizons: a shared vision for mental health1 is a cross‐government programme of action launched in December 2009, with the aim of improving the mental well‐being of people in England as well as the quality of mental health care. Here, Steve Titmarsh reports on the reactions of leading mental health charities Mind and Rethink to the launch of New Horizons. Copyright © 2010 Wiley Interface Ltd
Poly(ethylene oxide)‐like Plasma Polymers Produced by Plasma‐Assisted Vacuum Evaporation
Authors: Choukourov Andrei , Gordeev Ivan , Polonskyi Oleksandr , Artemenko Anna , Hanyková Lenka , Krakovský Ivan , Kylián Ondřej , Slavínská Danka , Biederman Hynek
Published: February 2010

Thermal decomposition of PEO under vacuum was used in combination with a glow discharge to deposit PEO‐like plasma polymer films. Evaporation without plasma allows the deposition of films with chemical composition very close to that of the original PEO, albeit with a lower average of molar mass. The application of plasma during vacuum evaporation leads to enhancement of crosslinking within the films, yet at the expense of reduced retention of ether structure. Non‐fouling properties and thrombogenicity of the plasma polymers were studied in terms of adhesion of blood proteins (albumin, immunoglobulin and fibrinogen) and promoting a thrombin induced fibrinogen/fibrin polymerization cascade.

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Computational delineation of the catalytic step of a high‐fidelity DNA polymerase
Authors: Venkatramani Ravindra , Radhakrishnan Ravi
Published: February 2010

The Bacillus fragment, belonging to a class of high‐fidelity polymerases, demonstrates high processivity (adding ∼115 bases per DNA binding event) and exceptional accuracy (1 error in 106 nucleotide incorporations) during DNA replication. We present analysis of structural rearrangements and energetics just before and during the chemical step (phosphodiester bond formation) using a combination of classical molecular dynamics, mixed quantum mechanics molecular mechanics simulations, and free energy computations. We find that the reaction is associative, proceeding via the two‐metal‐ion mechanism, and requiring the proton on the terminal primer O3′ to transfer to the pyrophosphate tail of the incoming nucleotide before the formation of the pentacovalent transition state. Different protonation states for key active site residues direct the system to alternative pathways of catalysis and we estimate a free energy barrier of ∼12 kcal/mol for the chemical step. We propose that the protonation of a highly conserved catalytic aspartic acid residue is essential for the high processivity demonstrated by the enzyme and suggest that global motions could be part of the reaction free energy landscape.
Folding and membrane insertion of amyloid‐beta (25–35) peptide and its mutants: Implications for aggregation and neurotoxicity
Authors: Tsai Hui‐Hsu Gavin , Lee Jian‐Bin , Tseng Sheng‐Shiuan , Pan Xiao‐An , Shih Yuan‐Ci
Published: February 2010

The mechanisms of interfacial folding and membrane insertion of the Alzheimer's amyloid‐β fragment Aβ(25–35) and its less toxic mutant, N27A‐Aβ(25–35) and more toxic mutant, M35A‐Aβ(25–35), are investigated using replica–exchange molecular dynamics in an implicit water‐membrane environment. This study simulates the processes of interfacial folding and membrane insertion in a spontaneous fashion to identify their general mechanisms. Aβ(25–35) and N27A‐Aβ(25–35) peptides share similar mechanisms: the peptides are first located in the membrane hydrophilic region where their C‐terminal residues form helical structures. The peptides attempt to insert themselves into the membrane hydrophobic region using the C‐terminal or central hydrophobic residues. A small portion of peptides can successfully enter the membrane's hydrophobic core, led by their C‐terminal residues, through the formation of continuous helical structures. No detectable amount of M35A‐Aβ(25–35) peptides appeared to enter the membrane's hydrophobic core. The three studied peptides share a similar helical structure for their C‐terminal five residues, and these residues mainly buried within the membrane's hydrophobic region. In contrast, their N‐terminal properties are markedly different. With respect to the Aβ(25–35), the N27A‐Aβ(25–35) forms a more structured helix and is buried deeper within the membrane, which may result in a lower degree of aggregation and a lower neurotoxicity; in contrast, the less structured and more water‐exposed M35A‐Aβ(25–35) is prone to aggregation and has a higher neurotoxicity. Understanding the mechanisms of Aβ peptide interfacial folding and membrane insertion will provide new insights into the mechanisms of neurodegradation and may give structure‐based clues for rational drug design preventing amyloid associated diseases. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Influence of quantum critical point of first‐order valence transition on Ce‐ and Yb‐based heavy fermions
Authors: Watanabe Shinji , Miyake Kazumasa
Published: February 2010

Influence of quantum critical point (QCP) of first‐order valence transition (FOVT) on Ce‐ and Yb‐based heavy fermions is discussed as a key origin of anomalies such as non‐Fermi liquid, metamagnetism, and unconventional superconductivity. Even in intermediate‐valence materials, the QCP of the FOVT is shown to be induced by applying the magnetic field, which creates a new characteristic energy distinct from the Kondo temperature. It is stressed that the key concept is closeness to the QCP of the FOVT by pointing out that the proximity of the QCP explains sharp contrast between X = Ag and X = Cd in YbXCu4, field‐induced valence crossover in X = Au, and field‐induced first‐order transition as well as non‐Fermi‐liquid critical behaviors in CeIrIn5. The valence fluctuations can be a key origin of unresolved phenomena in this family of materials.
A DFT study of determination of the reactive sites of the acetylcholine and its agonists: In the gas phase and dielectric medium
Authors: Serdaroğlu Goncagül
Published: February 2010

The reactive behavior of acetylcholine and its agonist molecules have been investigated using B3LYP hybrid density functional method at the 6‐311++G** basis set level, in the gas phase and aqueous phase. The calculations have been performed to obtain optimized geometries, relative reactivities, net atomic charges, HOMO, and LUMO energies. The solvent effect has been analyzed by using the continuum model (IPCM) and, the obtained results have shown that the all molecules have been stabilized more by solvent dielectric constant. For Ach and its analogues, it has been very well known that esteratic site and quaternary ammonium group which have reflected the difference in biological activity have been the two of the most important active site for interactions between molecule and its receptor. The structures of these analogues have provided an essential foundation for subsequent structure‐activity analysis of ligand binding at acetylcholine receptors, neuronal uptake inhibitors and transporters. Molecular modeling predictions will be important initial steps toward the development of novel pharmaceuticals in the fight acetylcholine‐related neurological disorders. This work is therefore expected to facilitate the design and development of new biologically active Ach analogues to treat Ach‐related neurological disorders and, specially is used to qualitative understanding of the reactivity and related properties and, so on can be used to a preselection of new ligands which at the moment is taken essentially from empirical knowledge. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
The lithium‐orientation effect on the hyperpolarizability in the short zigzag‐edged monolithiated aza‐Möbius graphene ribbon [2,7] isomers
Authors: Wang Yin‐Feng , Wang Yi , Li Zhi‐Ru , Li Zhuo , Xu Hong‐Liang , Sun Chia‐Chung
Published: February 2010

In the short zigzag‐edged aza‐Möbius graphene ribbon [2,7], a Li atom monosubstitutes the end H atom from the knot subring (1) to the subring (7), respectively, seven structures of short monolithiated aza‐Möbius graphene ribbon isomers [MöLi (1), MöLi (2), MöLi (3), MöLi (4), MöLi (5), MöLi (6), and MöLi (7)] with all the real frequencies are obtained at the B3LYP/6‐31G (d) level. The results of the static first hyperpolarizabilities (β0) show that lithiation effect on β0 is obvious. The β0 value of MöLi (4) (1019 a.u.) is about 4 times of 250 a.u. of the aza‐Möbius graphene ribbon. For the lithiated Möbius isomers, the lithium‐orientation effect is exhibited. The lithiated subring is or near the knot subring, the isomers [MöLi (1), MöLi (2), and MöLi (7)] have small β0 values, while that is far away from the knot subring, the isomers [MöLi (4) and MöLi (5)] have large β0 values. For the MöM (1) (M = Li, Na, and K), the alkali atomic number dependence for the static hyperpolarizability (α0) and β0 is found that both the α0 and β0 value increase with increasing the alkali atomic number in the orders of 275.27 (M = Li) < 279.75 (M = Na) < 284.77 a.u. and 352 (M = Li) < 590 (M = Na) < 706 a.u. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Development of a fast liquid chromatography/mass spectrometry screening method for angiotensin‐converting enzyme (ACE) inhibitors in complex natural mixtures like snake venom
Authors: Siemerink Mathijs , Schebb Nils Helge , Liesener André , Perchuc Anna‐Maria , Schöni Reto , Wilmer Marianne , Hayen Heiko , Karst Uwe , Vogel Martin
Published: February 2010

A new robust high‐performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI‐MS)‐based screening method for angiotensin‐converting enzyme (ACE)‐inhibiting substances in crude samples is described. The ACE assay is carried out in a typical offline setup by incubation of the samples with ACE and angiotensin I (AI), followed by stopping the reaction with acetonitrile containing val5‐AI serving as internal standard (I.S.). AI and the product angiotensin II (AII) are extracted from the incubation mixture by turbulent‐flow chromatography (TFC) applied in backflush mode as online solid‐phase extraction and are directly quantified by ESI(+)‐MS. The presence of ACE inhibitors (ACEi) is detected by an increase in AI signal intensity and a corresponding decrease of AII signal, as compared to the blank assay. The overall time of analysis of the TFC/ESI‐MS method was 5 min, thus making the described setup suitable for a rapid screening method. The assay was validated using a known ACE inhibitor and the IC50values found were in good accordance with a common HPLC/UV method and literature data. The method was successfully applied for the screening of size‐exclusion chromatography fractions of the venom of the pitviperBothrops moojeni. Three of 18 analyzed fractions inhibited ACE, due to peptides present as components of this snake venom. These compounds were extracted from the two most‐active fractions by means of TFC and isolated by means of HPLC. Three peptides with ACE inhibitory activity were characterized and their structures were elucidated with ESI‐MS/MS‐basedde novosequencing to be ZKWPPGKVPP, ZKWPRPGPEIPP and ZNWPRPGPEIPP, respectively (Z = pyroglutamic acid). Copyright © 2010 John Wiley & Sons, Ltd.