bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell cycle‐dependent activity of the volume‐ and Ca2+‐activated anion currents in Ehrlich lettre ascites cells
Authors: Klausen Thomas Kjær , Bergdahl Andreas , Hougaard Charlotte , Christophersen Palle , Pedersen Stine F. , Hoffmann Else K.
Published: November 2006

Recent evidence implicates the volume‐regulated anion current (VRAC) and other anion currents in control or modulation of cell cycle progression; however, the precise involvement of anion channels in this process is unclear. Here, Cl− currents in Ehrlich Lettre Ascites (ELA) cells were monitored during cell cycle progression, under three conditions: (i) after osmotic swelling (i.e., VRAC), (ii) after an increase in the free intracellular Ca2+ concentration (i.e., the Ca2+‐activated Cl− current, CaCC), and (iii) under steady‐state isotonic conditions. The maximal swelling‐activated VRAC current decreased in G1 and increased in early S phase, compared to that in G0. The isotonic steady‐state current, which seems to be predominantly VRAC, also decreased in G1, and increased again in early S phase, to a level similar to that in G0. In contrast, the maximal CaCC current (500 nM free Ca2+ in the pipette), was unaltered from G0 to G1, but decreased in early S phase. A novel high‐affinity anion channel inhibitor, the acidic di‐aryl‐urea NS3728, which inhibited both VRAC and CaCC, attenuated ELA cell growth, suggesting a possible mechanistic link between cell cycle progression and cell cycle‐dependent changes in the capacity for conductive Cl− transport. It is suggested that in ELA cells, entrance into the S phase requires an increase in VRAC activity and/or an increased potential for regulatory volume decrease (RVD), and at the same time a decrease in CaCC magnitude. J. Cell. Physiol. 210: 831–842, 2007. © 2006 Wiley‐Liss, Inc.
Solitary gastric melanotic schwannoma: Sonographic findings
Authors: Chen Yang‐Yuan , Yen Hsu‐Heng , Soon Maw‐Soan
Published: November 2006

Solitary gastric schwannoma is rare, and solitary melanotic schwannoma is even rarer, posing a dilemma in diagnosis and treatment. We report the case of a 69‐year‐old woman with gastric melanotic schwannoma who presented with nausea, vomiting, and abdominal pain. Abdominal sonographic examination revealed a 5‐cm hypoechoic mass in the epigastric area that was confirmed to be a gastric submucosal tumor on endoscopic examination. The diagnosis of melanotic schwannoma was confirmed via sonographically guided percutaneous core biopsy. The tumor was resected, and no recurrence has occurred in a 3‐year follow‐up. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound, 2006
Acyclic 5‐choosability of planar graphs without small cycles
Authors: Montassier Mickaël , Raspaud André , Wang Weifan
Published: November 2006

A proper vertex coloring of a graph G = (V,E) is acyclic if G contains no bicolored cycle. A graph G is acyclically L‐list colorable if for a given list assignment L = {L(v): v: ∈ V}, there exists a proper acyclic coloring ϕ of G such that ϕ(v) ∈  L(v) for all v ∈  V. If G is acyclically L‐list colorable for any list assignment with |L (v)|≥ k for all v ∈  V, then G is acyclically k‐choosable. In this article, we prove that every planar graph G without 4‐ and 5‐cycles, or without 4‐ and 6‐cycles is acyclically 5‐choosable. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 245–260, 2007
Determination of BAPTA‐AM, the acetoxymethyl tetraester of BAPTA, in rat plasma by liquid chromatography tandem mass spectrometry
Authors: Zheng Feng , Hang Taijun , Wu Chunyong , Di Bin , Liu Wenyin , Xu Jihua , Zhai Chunxiao , Sun Di , Liu Jinxing , Wei Wei
Published: November 2006

BAPTA‐AM is the acetoxymethylester of the calcium chelator BAPTA and has demonstrated efficacy in several animal models of cerebral ischemia. This paper describes the development of a method for the determination of BAPTA‐AM in rat plasma by liquid chromatography/tandem mass spectrometry. Owing to multiple ester groups in the structure of BAPTA‐AM, [M + Na]+ was chosen as the analytical ion for quantification of BAPTA‐AM. During the analytical method development, a high percentage of organic solvent and the addition of an amount of sodium acetate and formic acid in the mobile phase were found to favor the sensitivity and reproducibility of [M + Na]+. Poor fragmentation was usually observed in the MS/MS spectra of sodium adduct ions. However, abundant and reproducible fragment ions were observed for the BAPTA‐AM sodium adduct ion, and therefore the traditional selective reaction‐monitoring mode was used to further improve the sensitivity of MS detection. Because of the lability of the ester bond, a combination of fluoride and hydrochloric acid was applied to minimize the enzymatic hydrolysis, and acetonitrile was chosen to avoid the chemical hydrolysis or solvolysis during the sample collection and preparation procedure. On the basis of these studies, a rapid, sensitive and reproducible method for the determination of BAPTA‐AM in rat plasma, using LC/ESI‐MS/MS and a simple protein precipitation procedure, was developed and validated. Also, the present method was successfully applied to the determination of BAPTA‐AM plasma concentrations for pharmacokinetic studies in rats. Copyright © 2006 John Wiley & Sons, Ltd.
Climate teleconnections to Yangtze river seasonal streamflow at the Three Gorges Dam, China
Authors: Xu Kaiqin , Brown Casey , Kwon Hyun‐Han , Lall Upmanu , Zhang Jiqun , Hayashi Seiji , Chen Zhongyuan
Published: November 2006

In this study, we identify climatic influences on summer monsoon inflow to the Three Gorges Dam (TGD) in the Yangtze River Basin and use indices of these influences to predict streamflow one season ahead. Summer monsoon streamflow at Yichang hydrological station (YHS) was analyzed for the period 1882–2003. Statistical analysis was used to develop a predictive model for summer streamflow using preceding climate variables. Linear correlation maps were constructed using 3‐month ahead climate fields to identify regions that exhibit teleconnections with streamflow at Yichang. The analysis revealed regions in the eastern Indian and western Pacific Oceans that influence YHS streamflow. These regions and variables are consistent with those identified by previous studies of regional rainfall. In addition, snow cover in the Yangtze upland region provides predictive skill, likely due to snowmelt contributions to streamflow. A regression model for prediction using these indices provides a prediction R2 greater than 0.5, which is robust under the ‘leave one out’ cross‐validation. A skillful prediction can provide guidance for water management in the Yangtze River Basin, e.g. the Three Gorges Dam and future projects for South‐to‐North water transfer. Copyright © 2006 Royal Meteorological Society
Seasonal prediction of Korean regional climate from preceding large‐scale climate indices
Authors: Kim Maeng‐Ki , Kim Yeon‐Hee , Lee Woo‐Seop
Published: November 2006

On the basis of multivariate linear regression with an adaptive choice of climate indices as predictors, a seasonal forecast with a lead time of 2 months was applied to Korea on a monthly basis, and leave‐one‐out cross‐validation was applied to obtain forecasting skill at the 1% significance level. The monthly ACC (anomaly correlation coefficient) skill was 0.42–0.65 for temperature and 0.35–0.63 for precipitation. COD (coefficient of determination) was 18–42% for temperature and 14–39% for precipitation. The first coupled SLP pattern related to Korean climate is very similar to the correlation pattern between the preceding climate index and SLP at the target month, indicating that preceding climate indices can be dynamically linked to Korean climate. For example, the PNA index at a lead time of 5 months prior to October is closely related to a circulation anomaly with weak negative correlation over the Okhotsk Sea to East Sea and strong positive correlation over a broad band from Lake Baikal to China. This SLP pattern provides conditions that can dynamically induce cold advection from northwestern Asia around Lake Baikal toward the Korean Peninsula, resulting in cooling over Korea. Copyright © 2006 Royal Meteorological Society
Drought reconstruction for North Central China from tree rings: the value of the Palmer drought severity index
Authors: Li Jinbao , Chen Fahu , Cook Edward R. , Gou Xiaohua , Zhang Yongxiang
Published: November 2006

We present a drought reconstruction for north central China based on a tree ring‐width chronology developed from two sites of the Chinese pine (Pinus tabulaeformis) in the northern Helan Mountains. The drought reconstruction, spanning 1788–1999 A.D., was developed by calibrating tree‐ring data with the Palmer drought severity index (PDSI), an index that describes the regional moisture condition properly. The reconstruction was verified with independent data, and accounts for 45.7% of the actual PDSI variance during their common period (1941–1999). The full reconstruction indicates that the regional drought variability was relatively stable during the nineteenth century, but became more variable and persistent during the twentieth century. The drought epoch in the late 1920s was the most severe one in our reconstruction. In contrast to a wetting trend in the western area of northwest China, a clear drying trend has occurred in north central China since mid‐1930s. The multitaper method (MTM) spectral analysis indicates the existence of some decadal (∼11.4 year) and interannual (9.1, 6.8, 4.0, 2.7 and 2.1–2.0 year) cycles, which may potentially be the fingerprints of some proposed climate change forcings. Copyright © 2006 Royal Meteorological Society
Developing global leaders: Executive coaching targets cross‐cultural competencies
Authors: Handin Katherine , Steinwedel Janet S.
Published: November 2006

Leaders working with colleagues from other cultures or heading multicultural teams may find themselves stymied by their own apparent ineffectiveness and bewildered by the reactions of others. A new model of executive coaching can help individuals transform lifelong conditioning and personal assumptions into new beliefs and behaviors needed for cross‐cultural collaboration and leadership. The coachee draws on three core ethnorelative values and behaviors—curiosity, cultivation, and collaboration—and uses communication skills and reflection techniques to delve beneath the surface of each situation. Through self‐awareness and appreciation for others, the coachee becomes a leader who can deftly navigate cultural differences to build rewarding and productive relationships. © 2006 Wiley Periodicals, Inc.
Covance's global mentoring initiative develops people through exceptional partnerships
Authors: Darmstadter Miriam
Published: November 2006

The global mentoring program at Covance plays a dual role as a diversity initiative and a resource‐efficient developmental tool, providing a powerful developmental experience that enriches worklife for all participants. After studying successful programs in leading companies, the Covance team crafted a program that includes selection criteria and a careful matching process, training and tools for mentoring pairs, ongoing support, and close monitoring and evaluation. The company has also tackled the challenges of long‐distance mentoring relationships to make the program more accessible to its global workforce. As the program continues to grow and receive rave reviews, the Covance team continues to refine it for even greater effectiveness. © 2006 Wiley Periodicals, Inc.
Free radical scavengers are more effective than indomethacin in the prevention of experimentally induced heterotopic ossification
Authors: Vanden Bossche L.C. , Van Maele G. , Wojtowicz I. , De Cock K. , Vertriest S. , De Muynck M. , Rimbaut S. , Vanderstraeten G.G.
Published: November 2006

The pathogenesis of heterotopic ossification is still unclear and the preventive therapies are usually insufficient. The present study was designed to investigate the possible preventive effect of free radical scavengers on the development of experimentally induced heterotopic ossification in a rabbit model and to compare free radical scavengers with indomethacin to determine whether they act synergistically. A standard immobilization–manipulation model was used to induce heterotopical ossification in the hind legs of 40 1‐year‐old female New Zealand albino rabbits. The animals were divided into four groups and received daily either placebo, a free radical scavenger cocktail [allopurinol and N‐acetylcysteine (A/A)], indomethacin or the combination of A/A and indomethacin in a randomized double‐blind fashion. Every 4 days an X‐ray was taken and the thickness and length of new bone formation was measured at the thigh. A marked statistically significant difference was found between the four groups. In the groups that received A/A, either alone or combined with indomethacin, an inhibition of bone growth, both in thickness and in length was demonstrated. In this experimental model free radical scavengers had a superior inhibitory effect on heterotopic ossification than indomethacin. Free radicals could play an important role in the pathogenesis of heterotopic ossification. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:267–272, 2007
Bone formation after damaging in vivo fatigue loading results in recovery of whole‐bone monotonic strength and increased fatigue life
Authors: Silva Matthew J. , Touhey Daniel C.
Published: November 2006

Bone has a remarkable capacity for self‐repair. We previously reported a woven bone response after damaging in vivo fatigue loading of the rat ulna that led to a rapid recovery of whole‐bone strength. In the current study we asked: does the bone response in the 12 days after damaging fatigue loading result in a bone that has normal fatigue properties? The right forelimbs of 52 adult rats were subjected to a single bout of in vivo fatigue loading. Nonloaded left forelimbs were used as controls. Ulnar geometric properties were assessed by peripheral quantitative computed tomography (pQCT) and ex vivo mechanical properties were assessed by three‐point bending. On day 0, ulnae from loaded forelimbs had a 15–20% reduction in stiffness and ultimate force versus controls (p < 0.10), indicative of structural damage. On day 12, bone area at the midshaft was increased by 27% (p < 0.001) and microCT scans revealed periosteal woven bone at this site. This bone response led to a recovery of the monotonic properties of loaded ulnae at day 12 versus control (stiffness, p = 0.73; ultimate force, p = 0.96). Importantly, fatigue testing ex vivo at day 12 demonstrated significantly greater fatigue life in in vivo loaded ulnae versus controls (p < 0.001). Additionally, the slope of the fatigue‐life curve was significantly less in loaded versus control ulnae (p < 0.002). We conclude that woven bone “repair” of a bone damaged by fatigue loading restores whole‐bone strength and enhances resistance to further damage by repetitive loading. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:252–261, 2007
Gliding characteristics between flexor tendons and surrounding tissues in the carpal tunnel: A biomechanical cadaver study
Authors: Zhao Chunfeng , Ettema Anke M. , Osamura Naoki , Berglund Lawrence J. , An Kai‐Nan , Amadio Peter C.
Published: November 2006

The purpose of this study was to investigate the gliding characteristics of flexor tendons within the carpal tunnel with varied wrist positions and tendon motion styles, which may help us to understand the relationship between carpal tunnel syndrome (CTS) and repetitive hand motion. Eight fresh human cadaveric wrists and hands were used. The peak (PGR) and mean (MGR) gliding resistance of the middle finger flexor digitorum superficialis tendon were measured with the wrist in 0, 30, and 60° of flexion and extension. While moving all three fingers together, the PGR at 60° flexion was significantly higher than that at 0, 30, or 60° extension. While moving the middle finger alone, the PGR at 60 and 30° flexion was significantly higher than the PGR at 60° extension. The PGR moving the middle finger FDS alone was significantly greater than that for all three digits moving together in 0, 30, and 60° flexion. Differential finger motion with wrist flexion elevated the tendon gliding resistance in the carpal tunnel, which may be relevant in considering the possible role of wrist position and activity in the etiology of CTS. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:185–190, 2007
Concentration‐dependent Raman study of noncoincidence effect in the NH2 bending and CO stretching modes of HCONH2 in the binary mixture (HCONH2 + CH3OH)
Authors: Ojha Animesh K. , Srivastava Sunil K. , Asthana B. P. , Singh Ranjan K.
Published: November 2006

The isotropic and anisotropic parts of the Raman spectra of NH2 bending and ν(CO) stretching modes of HCONH2 in a hydrogen‐bonding solvent, methanol, at different concentrations have been analyzed carefully in order to study the noncoincidence effect (NCE). In neat HCONH2, the experimentally measured values of noncoincidence Δνnc are ∼11 and ∼18 cm−1 for the NH2 bending and ν(CO) stretching modes, which reduce to 0.45 and 1.14 cm−1, respectively at the concentration of HCONH2 in mole fraction, χm = 0.1. The experimental results have been explained on the basis of two models, namely, the microscopic prediction of Logan and the macroscopic model of Mirone and Fini. The relative success of the two models in explaining the experimental data for both the modes have been discussed. It has been observed that in case of the ν(CO) stretching vibrational mode the Logan model can reproduce the experimental data rather precisely, whereas in the case of the NH2 bending mode, Mirone and Fini model yields more accurate results. Copyright © 2006 John Wiley & Sons, Ltd.
Activity of cathepsins during beef aging related to mutations in the myostatin gene
Authors: Caballero Beatriz , Sierra Verónica , Oliván Mamen , Vega‐Naredo Ignacio , Tomás‐Zapico Cristina , Alvarez‐García Óscar , Tolivia Delio , Hardeland Rüdiger , Rodríguez‐Colunga María Josefa , Coto‐Montes Ana
Published: November 2006

Double‐muscled syndrome in cattle improves meat tenderness. However, the nature of the proteolytic processes associated with this phenomenon remains unknown. The aim of this study was to monitor changes in the activity of cathepsins (B, B + L, D and H) during meat aging and their gradual release from lysosomes to the cytosol in the longissimus muscle of yearling bulls of two breeds from northern Spain (Asturiana de los Valles and Asturiana de la Montaña) showing three genotypes for muscular hypertrophy (mh/mh, mh/+ and + / +). The data showed that the pattern of cathepsin activity during meat aging paralleled variations in tenderness in the different genotypes studied. Maximal cathepsin D activity and minimal cathepsin H activity were recorded during meat aging times ranging from 3 to 21 days. The activities of cathepsins B and B + L were lower than that of cathepsin D at the established time points (3, 7, 14 and 21 days post‐slaughter). The role of these enzymes in the activation of cathepsin D is discussed. All cathepsins showed similar action patterns, with high levels early on in the aging process and lower levels at later times. This pattern depended on the genotype and was significantly faster (P≤0.05) in meat from mh/mh animals, intermediate in meat from mh/+ animals and slower in meat from normal (+/+) animals of both breeds. Copyright © 2006 Society of Chemical Industry
Nutritional value of African yambean (Sphenostylis stenocarpa, L): improvement by solid substrate fermentation using the tempeh fungus Rhizopus oligosporus
Authors: Azeke Marshall A , Fretzdorff Barbara , Buening‐Pfaue Hans , Betsche Thomas
Published: November 2006

The tropical African yambean (AYB, Sphenostylis stenocarpa L.) is a hardy, protein‐rich under‐utilised African legume. Anti‐nutrients, and the excessively long cooking time (4–6 h), among other factors, limit the food use of African yambean seeds. To reduce these limitations, non‐traditional, less energy consuming processing methods are required. Seeds of different varieties were (1) examined for proximate composition and (2) fermented with Rhizopus oligosporus for the production of tempeh. The traditional production process involves dehulling, soaking in water for 24 h, boiling in water for 30 min, inoculation and fermentation. In addition, the traditional procedure for preparing tempeh was modified by using 1% citric acid solution instead of water for soaking and cooking. Comparisons with traditionally cooked beans, which involved boiling in water for 4 h, were made. The traditional tempeh procedure resulted in a slight but significant increase in protein and starch (P < 0.05) and an almost complete loss of most of the anti‐nutrients of AYB seeds, although the cyanogenic glycoside content of AYB‐white remained high. The modified procedure resulted in a bacteria‐free tempeh and the cyanogenic glycosides were no longer detectable. In vitro protein digestibility of the 1% citric acid treated sample was slightly lower than that of the water‐treated sample. Both tempeh production processes were clearly more effective and less energy intensive than traditional cooking in improving nutritional quality, but only the modified method of tempeh production eliminated the possibility of cyanide poisoning. Copyright © 2006 Society of Chemical Industry
Zero acquaintance benchmarking at travel destination websites: what is the first impression that national tourism organizations try to make?
Authors: Han Jee‐Hee , Mills Juline E.
Published: November 2006

This paper examines the marketing effectiveness of hospitality and tourism websites. An extensive review of literature on website effectiveness in hospitality and tourism revealed a total of 47 different instruments that have been used to evaluate hospitality and tourism websites. Using the grounded theory technique, a website evaluation tool called the online promotion evaluation instrument was developed with the aim of condensing the 47 existing tools into one benchmarked instrument with applicability across the various hospitality and tourism sectors. The developed online promotion evaluation instrument comprised three main features—aesthetics features (destination visualisation and Web design); informative features (uniqueness, monetary value and cultural promotion); and interactive features (e‐travel planners and online communities). The instrument was tested using a random sample of 25 National Tourism Organization websites worldwide. The results of the instrument development and testing process are presented in this paper with directions for future research in website evaluation. Copyright © 2006 John Wiley & Sons, Ltd.
Assessing the contribution of flagship projects to city image change: a quasi‐experimental technique
Authors: Smith Andrew
Published: November 2006

The aim of this paper is to identify a simple technique that can be used to indicate whether flagship urban projects contribute to city image change. The quasi‐experiment outlined is grounded in established marketing efficacy measures and involves establishing the relationship between awareness levels of projects and image change. After an explanation of the proposed technique, it is applied to projects in Birmingham, Manchester and Sheffield to demonstrate its potential value. Despite raising some concerns, the paper concludes that the technique provides a useful indicator of the effects of flagship projects, particularly when longitudinal research is not possible. Copyright © 2006 John Wiley & Sons, Ltd.
Representing protected areas: a critical discourse analysis of tourism destination building in a Greek travel magazine
Authors: Stamou Anastasia G. , Paraskevopoulos Stephanos
Published: November 2006

The present paper examines the way protected areas are constructed as tourism destinations by the information sources (i.e. a Greek travel magazine) that are consumed by potential visitors to such areas. Specifically, it explores what form of tourism is proposed for virtual visitors, whether it is ecotourism (i.e. both tourism and environmentalism) or simply a nature‐based one (i.e. exclusively tourism). Examining the way a Greek travel magazine builds protected areas as tourism destinations, and consequently what expectations are created for readers and potential visitors to such areas, the focus of the present paper is on whether the media contribute to the failure on the part of visitors to protected areas, who are the majority of the people engaging in ecotourism activities, to incorporate environmentalist besides tourism pursuits in their travel experiences. The analysis suggests that the travel magazine cultivates the view that other protected areas (with a tradition in mass tourism) are suitable for nature‐based tourism, others (with great ecological interest) for environmentalism, but few for ecotourism. This means that visitors to protected areas will probably have a difficulty in combining tourism with environmentalist pursuits, rather than in developing environmentalist concerns in general. Copyright © 2006 John Wiley & Sons, Ltd.
On the theory of superradiant scattering from Bose-Einstein condensate of dilute gas
Authors: Avetisyan Yu A , Trifonov E D
Published: November 2006

A semiclassical theory of superradiant scattering from Bose-Einstein condensate of dilute gas without the mean-field approximation is proposed. Solutions of the system of Maxwell-Schrödinger equations describing this effect as well as the coherent reflection of light and the backward amplification of matter waves are obtained.
Spatial spectroscopic diagnose of the plasma produced from laser ablation of a KTA crystal
Authors: Qi H , Sun Y , Liu X , Hou X , Li Y
Published: November 2006

Optical emission spectra of the plasma produced by the 1.06 μm Nd:YAG laser ablation of KTiOAsO4 (KTA) crystal in vacuum and in air is studied spectroscopically in time-integrated manner. Electron density and temperature in the plasma in vacuum are determined by using Stark-broadened line width of K atoms (KI 766.5 nm) and Boltzmann plot method with the relative intensities of 5 emission lines of singly ionized Ti ions, respectively. The dependences of electron density, electron temperature on distance from the target surface and laser irradiance are investigated. By comparing the optical emission spectra in vacuum with those in air, the effects of background gas are discussed. We also tested the validity of the assumptions for measuring electron temperature.
An experimental pathologic study of gingivectomy using dual‐wavelength laser equipment with OPO
Authors: Amagai Tetsuya , Kato Junji , Haruyama Chikahiro , Ohsuka Keigo , Takase Yasuaki , Hirai Yoshito
Published: November 2006

Background and Objectives

This study was conducted to evaluate how soft tissues respond to treatment by a tunable laser with an optical parametric oscillating (OPO) mechanism capable of simultaneously emitting two wavelengths.

Materials and Methods

Marginal gingiva of dogs was incised by a prototype laser oscillator. The oscillator was set at two wavelengths known to effectively incise tissue and arrest hemorrhage with minimal invasiveness. Four laser irradiation conditions were set based on different combinations of the 1.67 and 2.94 µm wavelengths. The animals were sacrificed immediately after surgery, 7 days after surgery, and 28 days after surgery for histological examination.

Results

When irradiation at 1.67 and 2.94 µm wavelengths was simultaneously applied, the former conferred an observable hemostatic effect and the latter incised the tissue. Wound healing was similar to that in conventional methods and no serious inflammation was observed.

Conclusion

Simultaneous irradiation at wavelengths of 1.67 and 2.94 µm can be an effective method in soft tissue surgery. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
An animal study of the effects on p16 and PCNA expression of repeated treatment with high‐energy laser and intense pulsed light exposure
Authors: Chan Henry H.L. , Yang C.H. , Leung Joseph C.K. , Wei W.I. , Lai K.N.
Published: November 2006

Background and Objective

Non‐ablative skin rejuvenation treatments that involve the use of laser/light sources together with cooling devices have gained much popularity in recent years due to the lack of down time that is associated with them. One important but neglected issue is long‐term safety. Does the repeated use of non‐ablative skin rejuvenation lead to photoaging? Are we creating another sun‐bed phenomenon? Recently, we performed an in vitro study to examine the effect of sub‐lethal QS 755 nm lasers on the expression of p16INK4a on melanoma cell lines, and found that sub‐lethal laser damage could increase DNA damage, which led to an increase in p16 expression. Our objective was to assess the cutaneous effect of repeated exposure to high‐energy lasers and intense pulsed light sources on male Institute of Cancer Research (ICR) mice.

Study Design/Materials and Methods

Twenty‐eight male ICR mice were divided into four groups. Other than the control group, all groups received either laser (585 nm pulsed dye laser or 1,320 nm Nd:YAG laser) or intense pulsed light (IPL) treatment. All four groups were anesthetized with a mixture of Hypnorm/Dormicum before treatment. The animals were irradiated twice a week for 6 months. Signs of toxicity such as mortality and weight loss were checked once a week. Skin tumor formation was evidenced by lesions of greater than 1 mm in diameter that persisted for 2 weeks. At the end of the 6 months, the expression of proliferating cell nuclear antigen (PCNA) and p16 in the mouse skin was determined by immunohistochemical staining and immunoblotting using specific monoclonal antibodies for mouse PCNA and p16. The results were expressed as mean ± standard error of the mean (SEM). Statistical difference was assessed by multiple ANOVA. A P‐value of <0.05 was considered to be significant.

Results

At the end of the 6 months, none of the animals had developed any signs of toxicity such as mortality or weight lost. There was no evidence of tumor formation. There were significant elevations of p16 and PCNA in all treated groups as compared to the control group (ANOVA P < 0.05). This particularly applied to the group that was treated with the 1,320 nm Nd:YAG laser.

Conclusion

The repeated use of high‐energy laser and intense pulsed light source did not cause any toxicity in mice. The changes in p16 and PCNA imply that further studies are necessary to consider the implications of repeated exposure to longer wavelength radiation in human skin. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Laser‐induced thermotherapy (LITT) elevates mRNA expression of connective tissue growth factor (CTGF) associated with reduced tumor growth of liver metastases compared to hepatic resection
Authors: Isbert Christoph , Ritz Jörg‐Peter , Roggan André , Schuppan Detlef , Ajubi Navid , Buhr Heinz Johannes , Hohenberger Werner , Germer Christoph‐Thomas
Published: November 2006

Background and Objectives

Proliferation and synthesis of hepatocellular tissue after tissue damage are promoted by specific growth factors such as hepatic tissue growth factor (HGF) and connective growth factor (CTGF). Laser‐induced thermotherapy (LITT) for the treatment of liver metastases is deemed to be a parenchyma‐saving procedure compared to hepatic resection. The aim of this study was to compare the impact of LITT and hepatic resection on intrahepatic residual tumor tissue and expression levels of mRNA HGF/CTGF within liver and tumor tissue.

Study Design/Materials and Methods

Two independent adenocarcinomas (CC531) were implanted into 75 WAG rats, one in the right (untreated tumor) and one in the left liver lobe (treated tumor). The left lobe tumor was treated either by LITT or partial hepatectomy. The control tumor was submitted to in‐situ hybridization of HGF and CTGF 24–96 hours and 14 days after intervention.

Results

Volumes of the untreated tumors prior to intervention were 38±8 mm3 in group I (laser), 39 ± 7 mm3 in group II (resection), and 42 ± 12 mm3 in group III (control) and did not differ significantly (P > 0.05). Fourteen days after the intervention the mean tumor±SEM volume of untreated tumor in group I (laser) [223 ± 36] was smaller than in group II (resection) [1233.28 ± 181.52; P < 0.001], and in group III (control) [978.92 ± 87.57; P < 0.003]. Forty‐eight hours after the intervention intrahepatic mRNA expression level of HGF in group II (resection) was almost twofold higher than in group I (laser) [7.2 ± 1.0 c/mf vs. 3.9 ± 0.4 c/mf; P<0.01]. Fourteen days after the intervention intrahepatic mRNA expression level of CTGF in group I (laser) was higher than in group II (resection) [13.89 ± 0.77 c/mf vs. 9.09 ± 0.78 c/mf; P < 0.003].

Conclusions

LITT leads to a decrease of residual tumor growth in comparison to hepatic resection. Accelerated tumor growth after hepatic resection is associated with higher mRNA level of HGF and reduced tumor growth after LITT with higher mRNA level of CTGF. The increased CTGF‐mediated regulation of ECM may cause reduced residual tumor growth after LITT. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
In Situ Synthesis of Mg/Si Polymer Composites via Emulsion Polymerization
Authors: Pankow Oliver , Schmidt‐Naake Gudrun
Published: November 2006

Summary: Different styrene‐ and acrylate‐based organic‐inorganic polymer composites incorporating magnesium hydroxide were successfully synthesized using MPTMS as a coupling agent and MgCl2 as an inorganic precursor. The polymer composites were prepared by free‐radical emulsion polymerization following different procedures. The samples were investigated by means of FT‐IR spectroscopy, XRD, TGA, DSC, and rheometry. It is shown that the preparation method does only affect the ratio of organic to inorganic component, but not the chemical structure of the composites. The obtained polymer composites consist of Mg(OH)2 particles which are linked covalently via MPTMS groups to the polymer backbone.

Scheme of Mg(OH)2 crosslinked with MPTMS units as proposed for the emulsion polymer composite.

magnified image

Scheme of Mg(OH)2 crosslinked with MPTMS units as proposed for the emulsion polymer composite.
Polyimide Fibers Obtained by Spinning Lyotropic Solutions of Rigid‐Rod Aromatic Poly(amic ethyl ester)s
Authors: Neuber Christian , Schmidt Hans‐Werner , Giesa Reiner
Published: November 2006

Summary: Fibers were spun from a lyotropic solution of a high‐molecular‐weight (η = 5.89 g · dL−1), rigid‐rod, fully aromatic polyimide precursor polymer in a dry‐jet, wet‐spinning process in NMP. Acetone was identified as the coagulant of choice since fibers could be drawn extensively in this solvent, resulting in improved mechanical properties (tensile modulus: E = 17 GPa, strength at break: σbreak = 400 MPa, elongation at break: εbreak = 5.3%) and orientation, which was shown by WAXS patterns. SEM images showed a layered, skin‐core morphology without any visible fibrillation. Additional processing of these fibers by step‐wise hot‐drawing up to 400 °C under tension rendered oriented polyimide fibers with excellent mechanical properties. (E = 68 GPa, σbreak = 700 MPa, εbreak = 1%). An analysis of the WAXS diffraction patterns showed an improved orientation of the fibers in the axial and lateral directions; however, probably due to the CF3 side groups, the lateral distance was still too large for crystallization. SEM images of these imidized fibers showed, for the first time, a fibrillar morphology in addition to the typical, skin‐core, sheet‐like morphology.

SEM image of the hot‐drawn fiber PI 4 (12). The image shows a skin‐core morphology which was delaminating into ribbons during preparation.

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SEM image of the hot‐drawn fiber PI 4 (12). The image shows a skin‐core morphology which was delaminating into ribbons during preparation.
Core‐Sheath Structure in Electrospun Nanofibers from Polymer Blends
Authors: Wei Ming , Kang Bongwoo , Sung Changmo , Mead Joey
Published: November 2006

Summary: Electrospinning of polymer blends offers the potential to prepare functional nanofibers for use in a variety of applications. This work focused on control of the internal morphology of nanofibers prepared by electrospinning polymer blends to obtain core‐sheath structures. Polybutadiene/polystyrene, poly(methylmethacrylate)/polystyrene, polybutadiene/poly(methylmethacrylate), polybutadiene/polycarbonate, polyaniline/polycarbonate, and poly(methylmethacrylate)/polycarbonate blends were electrospun from polymer solutions. It was found that the formation of core‐sheath structures depends on both thermodynamic and kinetic factors. Incompatibility and large solubility parameter difference of the two polymers is helpful for good phase separation, but not sufficient for the formation of core‐sheath structures. Kinetic factors, however, play a much more important role in the development of the nanofiber morphology. During the electrospinning process, the rapid solvent evaporation requires systems with high molecular mobility for the formation of core‐sheath structures. It was found that polymer blends with lower molecular weight tend to form core‐sheath structures rather than co‐continuous structures, as a result of their higher molecular mobility. Rheological factors also affect the internal phase morphology of nanofibers. It was observed the composition with higher viscosity was always located at the center and the composition with lower viscosity located outside.

TEM image of electrospun polybutadiene/polycarbonate nanofibers at 25/75 wt.‐% ratio after staining by osmium tetroxide. The dark regions are polybutadiene and the light region is polycarbonate.

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TEM image of electrospun polybutadiene/polycarbonate nanofibers at 25/75 wt.‐% ratio after staining by osmium tetroxide. The dark regions are polybutadiene and the light region is polycarbonate.
Front Cover: Macromol. Mater. Eng. 11/2006
Authors: Neuber Christian , Schmidt Hans‐Werner , Giesa Reiner
Published: November 2006

Front Cover: The picture on the cover shows an SEM image of a polyimide fiber hot‐drawn at 400°C. The image shows a typical skin‐core morphology; the skin layer delaminated into thin ribbons during preparation. In addition the skin and core show the formation of very fine fibrils. Further details can be found in the article by C. Neuber, H.‐W. Schmidt, and R. Giesa* on page 1315.
Synthesis of Five‐Arm Star Polymers with an Inositol Core by Atom Transfer Radical Polymerisation at Ambient Temperature
Authors: Kimani Solomon M. , Moratti Stephen C.
Published: November 2006

Summary: A novel hydroxyl‐functionalised initiator for atom transfer radical polymerisation (ATRP) was synthesised by esterification reaction of a non‐reducing sugar, meso‐inositol. Due to steric hindrance, one of the six hydroxyl groups present in the sugar was not derivatised to the corresponding 2‐bromoisobutyrate. The macroinitiator was used in ambient temperature ATRP of a hydrophobic monomer, methyl methacrylate (MMA) and a hydrophilic monomer, oligoethylene glycol methacrylate (OEGMA) using tri(ethylene glycol) monomethyl ether (TEGMME) as the polymerisation solvent and CuCl/CuCl2/PMDETA as the catalytic system. Under these conditions, polymerisation proceeded on to high conversion while maintaining low polydispersity giving well‐defined five‐arm star polymers. Hydrolysis under basic conditions was carried out to deduce the number of linear chains that were attached to the sugar.

Five‐arm star polymer.

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Five‐arm star polymer.
Self‐Assembled, Thermosensitive PCL‐g‐P(NIPAAm‐co‐HEMA) Micelles for Drug Delivery
Authors: Li Yong‐Yong , Zhang Xian‐Zheng , Cheng Han , Zhu Jing‐Ling , Cheng Si‐Xue , Zhuo Ren‐Xi
Published: November 2006

Summary: A novel thermosensitive amphiphilic copolymer (PCL‐g‐P(NIPAAm‐co‐HEMA)) comprised of hydrophobic PCL segments and hydrophilic P(NIPAAm‐co‐HEMA) segments was designed and synthesized. The structure of the copolymer was characterized by FT‐IR, 1H NMR and GPC analysis. The copolymer may self‐assemble into micelles in water and the resulting micelles demonstrated temperature sensitivity with a lower critical solution temperature (LCST) of 33 °C. The critical micellar concentration (CMC) obtained from surface tension measurements and the fluorescence method was around 30 mg · L−1. Transmission electron microscopy (TEM) showed that the micelles exhibit a nanospheric morphology within a narrow size range of 150–160 nm. A cytotoxicity study showed that the PCL‐g‐P(NIPAAm‐co‐HEMA) copolymer exhibits good biocompatibility. The controlled drug release of the resulting micelles was investigated and it was found that micelles loaded with prednisone acetate showed improved drug release behavior due to the special micellar structure.

Self‐assembly of the PCL‐g‐P(NIPAAm‐co‐HEMA) copolymers.

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Self‐assembly of the PCL‐g‐P(NIPAAm‐co‐HEMA) copolymers.
One‐Pot Difunctionalization of Poly(ω‐pentadecalactone) with Thiol‐Thiol or Thiol‐Acrylate Groups, Catalyzed by Candida antarctica Lipase B
Authors: Takwa Mohamad , Simpson Neil , Malmström Eva , Hult Karl , Martinelle Mats
Published: November 2006

Summary: An enzymatic one‐pot procedure has been developed for the synthesis of difunctional polyesters containing terminal thiols and acrylates. Candida antarctica lipase B was used as a catalyst for the ring‐opening polymerization of ω‐pentadecalactone. The polymerization was initiated with 6‐mercaptohexanol, then terminated with γ‐thiobutyrolactone or vinyl acrylate to create two types of difunctional polyesters with a very high content of thiol‐thiol or thiol‐acrylate end‐groups.

Difunctionalization of poly‐PDL.

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Difunctionalization of poly‐PDL.
Titanium‐Catalyzed Norbornene Oligomerization. Isolation of a Crystalline Heptamer with a 2,3‐exo‐Disyndiotactic Structure
Authors: Porri Lido , Scalera Valerio N. , Bagatti Matteo , Famulari Antonino , Meille Stefano V.
Published: November 2006

Summary: Norbornene (NB) was oligomerized at 0 °C using AlEt2Cl‐TiCl4 at a monomer/titanium molar ratio of about 11. The oligomerization product consists of a fraction soluble in diethyl ether, amorphous by X‐ray examination, and of a crystalline fraction, insoluble in diethyl ether. The crystalline fraction was shown by powder X‐ray diffraction to consist of a NB heptamer. Single‐crystal X‐ray analysis indicated that the heptamer had a stereoregular 2,3‐exo‐disyndiotactic structure. The heptamer adopts a strained, highly irregular, folded conformation in the crystalline state. Structural differences with respect to NB oligomers obtained with zirconocene catalysts are discussed.

A view of the molecular structure of the crystalline NB heptamer.

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A view of the molecular structure of the crystalline NB heptamer.
Synthesis of Block Copolymers Modified with Phosphonate Ester Groups Using Nitroxide‐Mediated Radical Polymerization
Authors: Britze Antje , Moosmann Katrin , Jähne Evelin , Adler Hans‐Jürgen , Kuckling Dirk
Published: November 2006

Summary: Phosphonate groups were introduced into block copolymers of styrene derivatives either as single end‐groups or as small blocks using nitroxide‐mediated radical polymerization. In order to combine the hydrophobic and hydrophilic segments, block copolymers with N,N‐dimethyl acrylamide were synthesized. After hydrolysis to phosphonic acid groups, adsorption of the polymer onto metal oxides was possible.

Conversion of the phosphonate groups by transesterification with trimethylbromosilane (TMBS), followed by hydrolysis of the silylester group.

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Conversion of the phosphonate groups by transesterification with trimethylbromosilane (TMBS), followed by hydrolysis of the silylester group.
Regioregularity in Poly(3‐alkoxythiophene)s: Effects on the Faraday Rotation and Polymerization Mechanism
Authors: Koeckelberghs Guy , Vangheluwe Marnix , Doorsselaere Kim Van , Robijns Elke , Persoons André , Verbiest Thierry
Published: November 2006

Summary: Poly(3‐alkoxythiophene)s with different degrees of regioregularity were prepared using three different methodologies. It is shown that their Faraday rotation is highly dependent on the degree of regioregularity. The origin of the differences in regiospecificity of the methodologies is discussed.

Structure of the polymer pol 3.

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Structure of the polymer pol 3.
Cover Picture: Macromol. Rapid Commun. 22/2006
Authors: Zhang Kai , Chen Zhao , Yang Chuluo , Gong Shaolong , Qin Jingui , Cao Yong
Published: November 2006

Cover: A series of novel copolymers with fluorene‐alt‐carbazole segments and β‐diketonate moieties coordinating to iridium have been synthesized by Suzuki polycondensation. The electroluminescent devices using the copolymers as emitting layer show saturated red‐emission at 628 nm. All the devices are almost free of efficiency decay with increasing current density. Further details can be found in the article by K. Zhang, Z. Chen, C. Yang,* S. Gong, J. Qin,* Y. Cao* on page 1926.
Screening for Lrrk2 G2019S and clinical comparison of Tunisian and North American Caucasian Parkinson's disease families
Authors: Ishihara Lianna , Gibson Rachel A. , Warren Liling , Amouri Rim , Lyons Kelly , Wielinski Catherine , Hunter Christine , Swartz Jina E. , Elango Ramu , Akkari P. Anthony , Leppert David , Surh Linda , Reeves Kevin H. , Thomas Siwan , Ragone Leigh , Hattori Nobutaka , Pahwa Rajesh , Jankovic Joseph , Nance Martha , Freeman Alan , Gouider‐Khouja Neziha , Kefi Mounir , Zouari Mourad , Ben Sassi Samia , Ben Yahmed Samia , El Euch‐Fayeche Ghada , Middleton Lefkos , Burn David J. , Watts Ray L. , Hentati Faycal
Published: November 2006

Mutations in the leucine‐rich repeat kinase‐2 gene (LRRK2) are responsible for some forms of familial as well as sporadic Parkinson's disease (PD). The purpose of this study was to examine the frequency of a single pathogenic mutation (6055G>A) in the kinase domain of this gene in United States and Tunisian familial PD and to compare clinical characteristics between patients with and without the mutation. Standardized case report forms were used for clinical and demographic data collection. We investigated the frequency of the most common substitution of LRRK2 (G2019S, 6055G>A) and its impact on epidemiological and phenotypic features. The frequency of mutations in Tunisian families was 42% (38/91) and in U.S. families 2.6% (1/39), with the unique opportunity to compare homozygous (n = 23) and heterozygous (n = 109) Tunisian carriers of G2019S substitutions. Individuals with G2019S substitutions had an older age at onset but few other differences compared with families negative for the substitution. Patients with LRRK2 mutations had typical clinical features of PD. Comparisons between individuals with heterozygous and homozygous LRRK2 mutations suggested that gene dosage was not correlated with phenotypic differences; however, the estimated penetrance was greater in homozygotes across all age groups. © 2006 Movement Disorder Society
Evidence‐based guidelines for using the Short Form 36 in cervical dystonia
Authors: Cano Stefan J. , Thompson Alan J. , Bhatia Khailash , Fitzpatrick Ray , Warner Thomas T. , Hobart Jeremy C.
Published: November 2006

We aimed to provide evidence‐based guidelines for using the Short Form 36 (SF‐36) as an outcome measure in cervical dystonia (CD). To do this, we tested the hypothesized relationships between items, scales, and summary measures of the SF‐36 using psychometric analyses in data from a postal survey of 235 people with CD. Although the majority of subscales performed adequately, the Role Physical and Role Emotional subscales had substantial floor and/or ceiling effects. Evidence did not support computing SF‐36 Physical and Mental Component Summary scores. We propose guidelines that include the recommendation that these subscale and summary scores should be reported with caution. © 2006 Movement Disorder Society